if_wg.c revision 1.78 1 /* $NetBSD: if_wg.c,v 1.78 2024/03/10 04:21:47 riastradh Exp $ */
2
3 /*
4 * Copyright (C) Ryota Ozaki <ozaki.ryota (at) gmail.com>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the project nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 /*
33 * This network interface aims to implement the WireGuard protocol.
34 * The implementation is based on the paper of WireGuard as of
35 * 2018-06-30 [1]. The paper is referred in the source code with label
36 * [W]. Also the specification of the Noise protocol framework as of
37 * 2018-07-11 [2] is referred with label [N].
38 *
39 * [1] https://www.wireguard.com/papers/wireguard.pdf
40 * [2] http://noiseprotocol.org/noise.pdf
41 */
42
43 #include <sys/cdefs.h>
44 __KERNEL_RCSID(0, "$NetBSD: if_wg.c,v 1.78 2024/03/10 04:21:47 riastradh Exp $");
45
46 #ifdef _KERNEL_OPT
47 #include "opt_altq_enabled.h"
48 #include "opt_inet.h"
49 #endif
50
51 #include <sys/param.h>
52 #include <sys/types.h>
53
54 #include <sys/atomic.h>
55 #include <sys/callout.h>
56 #include <sys/cprng.h>
57 #include <sys/cpu.h>
58 #include <sys/device.h>
59 #include <sys/domain.h>
60 #include <sys/errno.h>
61 #include <sys/intr.h>
62 #include <sys/ioctl.h>
63 #include <sys/kernel.h>
64 #include <sys/kmem.h>
65 #include <sys/mbuf.h>
66 #include <sys/module.h>
67 #include <sys/mutex.h>
68 #include <sys/once.h>
69 #include <sys/percpu.h>
70 #include <sys/pserialize.h>
71 #include <sys/psref.h>
72 #include <sys/queue.h>
73 #include <sys/rwlock.h>
74 #include <sys/socket.h>
75 #include <sys/socketvar.h>
76 #include <sys/sockio.h>
77 #include <sys/sysctl.h>
78 #include <sys/syslog.h>
79 #include <sys/systm.h>
80 #include <sys/thmap.h>
81 #include <sys/threadpool.h>
82 #include <sys/time.h>
83 #include <sys/timespec.h>
84 #include <sys/workqueue.h>
85
86 #include <net/bpf.h>
87 #include <net/if.h>
88 #include <net/if_types.h>
89 #include <net/if_wg.h>
90 #include <net/pktqueue.h>
91 #include <net/route.h>
92
93 #include <netinet/in.h>
94 #include <netinet/in_pcb.h>
95 #include <netinet/in_var.h>
96 #include <netinet/ip.h>
97 #include <netinet/ip_var.h>
98 #include <netinet/udp.h>
99 #include <netinet/udp_var.h>
100
101 #ifdef INET6
102 #include <netinet/ip6.h>
103 #include <netinet6/in6_pcb.h>
104 #include <netinet6/in6_var.h>
105 #include <netinet6/ip6_var.h>
106 #include <netinet6/udp6_var.h>
107 #endif /* INET6 */
108
109 #include <prop/proplib.h>
110
111 #include <crypto/blake2/blake2s.h>
112 #include <crypto/sodium/crypto_aead_chacha20poly1305.h>
113 #include <crypto/sodium/crypto_aead_xchacha20poly1305.h>
114 #include <crypto/sodium/crypto_scalarmult.h>
115
116 #include "ioconf.h"
117
118 #ifdef WG_RUMPKERNEL
119 #include "wg_user.h"
120 #endif
121
122 /*
123 * Data structures
124 * - struct wg_softc is an instance of wg interfaces
125 * - It has a list of peers (struct wg_peer)
126 * - It has a threadpool job that sends/receives handshake messages and
127 * runs event handlers
128 * - It has its own two routing tables: one is for IPv4 and the other IPv6
129 * - struct wg_peer is a representative of a peer
130 * - It has a struct work to handle handshakes and timer tasks
131 * - It has a pair of session instances (struct wg_session)
132 * - It has a pair of endpoint instances (struct wg_sockaddr)
133 * - Normally one endpoint is used and the second one is used only on
134 * a peer migration (a change of peer's IP address)
135 * - It has a list of IP addresses and sub networks called allowedips
136 * (struct wg_allowedip)
137 * - A packets sent over a session is allowed if its destination matches
138 * any IP addresses or sub networks of the list
139 * - struct wg_session represents a session of a secure tunnel with a peer
140 * - Two instances of sessions belong to a peer; a stable session and a
141 * unstable session
142 * - A handshake process of a session always starts with a unstable instance
143 * - Once a session is established, its instance becomes stable and the
144 * other becomes unstable instead
145 * - Data messages are always sent via a stable session
146 *
147 * Locking notes:
148 * - Each wg has a mutex(9) wg_lock, and a rwlock(9) wg_rwlock
149 * - Changes to the peer list are serialized by wg_lock
150 * - The peer list may be read with pserialize(9) and psref(9)
151 * - The rwlock (wg_rwlock) protects the routing tables (wg_rtable_ipv[46])
152 * => XXX replace by pserialize when routing table is psz-safe
153 * - Each peer (struct wg_peer, wgp) has a mutex wgp_lock, which can be taken
154 * only in thread context and serializes:
155 * - the stable and unstable session pointers
156 * - all unstable session state
157 * - Packet processing may be done in softint context:
158 * - The stable session can be read under pserialize(9) or psref(9)
159 * - The stable session is always ESTABLISHED
160 * - On a session swap, we must wait for all readers to release a
161 * reference to a stable session before changing wgs_state and
162 * session states
163 * - Lock order: wg_lock -> wgp_lock
164 */
165
166
167 #define WGLOG(level, fmt, args...) \
168 log(level, "%s: " fmt, __func__, ##args)
169
170 /* Debug options */
171 #ifdef WG_DEBUG
172 /* Output debug logs */
173 #ifndef WG_DEBUG_LOG
174 #define WG_DEBUG_LOG
175 #endif
176 /* Output trace logs */
177 #ifndef WG_DEBUG_TRACE
178 #define WG_DEBUG_TRACE
179 #endif
180 /* Output hash values, etc. */
181 #ifndef WG_DEBUG_DUMP
182 #define WG_DEBUG_DUMP
183 #endif
184 /* Make some internal parameters configurable for testing and debugging */
185 #ifndef WG_DEBUG_PARAMS
186 #define WG_DEBUG_PARAMS
187 #endif
188 #endif
189
190 #ifdef WG_DEBUG_TRACE
191 #define WG_TRACE(msg) \
192 log(LOG_DEBUG, "%s:%d: %s\n", __func__, __LINE__, (msg))
193 #else
194 #define WG_TRACE(msg) __nothing
195 #endif
196
197 #ifdef WG_DEBUG_LOG
198 #define WG_DLOG(fmt, args...) log(LOG_DEBUG, "%s: " fmt, __func__, ##args)
199 #else
200 #define WG_DLOG(fmt, args...) __nothing
201 #endif
202
203 #define WG_LOG_RATECHECK(wgprc, level, fmt, args...) do { \
204 if (ppsratecheck(&(wgprc)->wgprc_lasttime, \
205 &(wgprc)->wgprc_curpps, 1)) { \
206 log(level, fmt, ##args); \
207 } \
208 } while (0)
209
210 #ifdef WG_DEBUG_PARAMS
211 static bool wg_force_underload = false;
212 #endif
213
214 #ifdef WG_DEBUG_DUMP
215
216 static char *
217 gethexdump(const char *p, size_t n)
218 {
219 char *buf;
220 size_t i;
221
222 if (n > SIZE_MAX/3 - 1)
223 return NULL;
224 buf = kmem_alloc(3*n + 1, KM_NOSLEEP);
225 if (buf == NULL)
226 return NULL;
227 for (i = 0; i < n; i++)
228 snprintf(buf + 3*i, 3 + 1, " %02hhx", p[i]);
229 return buf;
230 }
231
232 static void
233 puthexdump(char *buf, const void *p, size_t n)
234 {
235
236 if (buf == NULL)
237 return;
238 kmem_free(buf, 3*n + 1);
239 }
240
241 #ifdef WG_RUMPKERNEL
242 static void
243 wg_dump_buf(const char *func, const char *buf, const size_t size)
244 {
245 char *hex = gethexdump(buf, size);
246
247 log(LOG_DEBUG, "%s: %s\n", func, hex ? hex : "(enomem)");
248 puthexdump(hex, buf, size);
249 }
250 #endif
251
252 static void
253 wg_dump_hash(const uint8_t *func, const uint8_t *name, const uint8_t *hash,
254 const size_t size)
255 {
256 char *hex = gethexdump(hash, size);
257
258 log(LOG_DEBUG, "%s: %s: %s\n", func, name, hex ? hex : "(enomem)");
259 puthexdump(hex, hash, size);
260 }
261
262 #define WG_DUMP_HASH(name, hash) \
263 wg_dump_hash(__func__, name, hash, WG_HASH_LEN)
264 #define WG_DUMP_HASH48(name, hash) \
265 wg_dump_hash(__func__, name, hash, 48)
266 #define WG_DUMP_BUF(buf, size) \
267 wg_dump_buf(__func__, buf, size)
268 #else
269 #define WG_DUMP_HASH(name, hash) __nothing
270 #define WG_DUMP_HASH48(name, hash) __nothing
271 #define WG_DUMP_BUF(buf, size) __nothing
272 #endif /* WG_DEBUG_DUMP */
273
274 /* chosen somewhat arbitrarily -- fits in signed 16 bits NUL-terminated */
275 #define WG_MAX_PROPLEN 32766
276
277 #define WG_MTU 1420
278 #define WG_ALLOWEDIPS 16
279
280 #define CURVE25519_KEY_LEN 32
281 #define TAI64N_LEN sizeof(uint32_t) * 3
282 #define POLY1305_AUTHTAG_LEN 16
283 #define HMAC_BLOCK_LEN 64
284
285 /* [N] 4.1: "DHLEN must be 32 or greater." WireGuard chooses 32. */
286 /* [N] 4.3: Hash functions */
287 #define NOISE_DHLEN 32
288 /* [N] 4.3: "Must be 32 or 64." WireGuard chooses 32. */
289 #define NOISE_HASHLEN 32
290 #define NOISE_BLOCKLEN 64
291 #define NOISE_HKDF_OUTPUT_LEN NOISE_HASHLEN
292 /* [N] 5.1: "k" */
293 #define NOISE_CIPHER_KEY_LEN 32
294 /*
295 * [N] 9.2: "psk"
296 * "... psk is a 32-byte secret value provided by the application."
297 */
298 #define NOISE_PRESHARED_KEY_LEN 32
299
300 #define WG_STATIC_KEY_LEN CURVE25519_KEY_LEN
301 #define WG_TIMESTAMP_LEN TAI64N_LEN
302
303 #define WG_PRESHARED_KEY_LEN NOISE_PRESHARED_KEY_LEN
304
305 #define WG_COOKIE_LEN 16
306 #define WG_MAC_LEN 16
307 #define WG_RANDVAL_LEN 24
308
309 #define WG_EPHEMERAL_KEY_LEN CURVE25519_KEY_LEN
310 /* [N] 5.2: "ck: A chaining key of HASHLEN bytes" */
311 #define WG_CHAINING_KEY_LEN NOISE_HASHLEN
312 /* [N] 5.2: "h: A hash output of HASHLEN bytes" */
313 #define WG_HASH_LEN NOISE_HASHLEN
314 #define WG_CIPHER_KEY_LEN NOISE_CIPHER_KEY_LEN
315 #define WG_DH_OUTPUT_LEN NOISE_DHLEN
316 #define WG_KDF_OUTPUT_LEN NOISE_HKDF_OUTPUT_LEN
317 #define WG_AUTHTAG_LEN POLY1305_AUTHTAG_LEN
318 #define WG_DATA_KEY_LEN 32
319 #define WG_SALT_LEN 24
320
321 /*
322 * The protocol messages
323 */
324 struct wg_msg {
325 uint32_t wgm_type;
326 } __packed;
327
328 /* [W] 5.4.2 First Message: Initiator to Responder */
329 struct wg_msg_init {
330 uint32_t wgmi_type;
331 uint32_t wgmi_sender;
332 uint8_t wgmi_ephemeral[WG_EPHEMERAL_KEY_LEN];
333 uint8_t wgmi_static[WG_STATIC_KEY_LEN + WG_AUTHTAG_LEN];
334 uint8_t wgmi_timestamp[WG_TIMESTAMP_LEN + WG_AUTHTAG_LEN];
335 uint8_t wgmi_mac1[WG_MAC_LEN];
336 uint8_t wgmi_mac2[WG_MAC_LEN];
337 } __packed;
338
339 /* [W] 5.4.3 Second Message: Responder to Initiator */
340 struct wg_msg_resp {
341 uint32_t wgmr_type;
342 uint32_t wgmr_sender;
343 uint32_t wgmr_receiver;
344 uint8_t wgmr_ephemeral[WG_EPHEMERAL_KEY_LEN];
345 uint8_t wgmr_empty[0 + WG_AUTHTAG_LEN];
346 uint8_t wgmr_mac1[WG_MAC_LEN];
347 uint8_t wgmr_mac2[WG_MAC_LEN];
348 } __packed;
349
350 /* [W] 5.4.6 Subsequent Messages: Transport Data Messages */
351 struct wg_msg_data {
352 uint32_t wgmd_type;
353 uint32_t wgmd_receiver;
354 uint64_t wgmd_counter;
355 uint32_t wgmd_packet[0];
356 } __packed;
357
358 /* [W] 5.4.7 Under Load: Cookie Reply Message */
359 struct wg_msg_cookie {
360 uint32_t wgmc_type;
361 uint32_t wgmc_receiver;
362 uint8_t wgmc_salt[WG_SALT_LEN];
363 uint8_t wgmc_cookie[WG_COOKIE_LEN + WG_AUTHTAG_LEN];
364 } __packed;
365
366 #define WG_MSG_TYPE_INIT 1
367 #define WG_MSG_TYPE_RESP 2
368 #define WG_MSG_TYPE_COOKIE 3
369 #define WG_MSG_TYPE_DATA 4
370 #define WG_MSG_TYPE_MAX WG_MSG_TYPE_DATA
371
372 /* Sliding windows */
373
374 #define SLIWIN_BITS 2048u
375 #define SLIWIN_TYPE uint32_t
376 #define SLIWIN_BPW NBBY*sizeof(SLIWIN_TYPE)
377 #define SLIWIN_WORDS howmany(SLIWIN_BITS, SLIWIN_BPW)
378 #define SLIWIN_NPKT (SLIWIN_BITS - NBBY*sizeof(SLIWIN_TYPE))
379
380 struct sliwin {
381 SLIWIN_TYPE B[SLIWIN_WORDS];
382 uint64_t T;
383 };
384
385 static void
386 sliwin_reset(struct sliwin *W)
387 {
388
389 memset(W, 0, sizeof(*W));
390 }
391
392 static int
393 sliwin_check_fast(const volatile struct sliwin *W, uint64_t S)
394 {
395
396 /*
397 * If it's more than one window older than the highest sequence
398 * number we've seen, reject.
399 */
400 #ifdef __HAVE_ATOMIC64_LOADSTORE
401 if (S + SLIWIN_NPKT < atomic_load_relaxed(&W->T))
402 return EAUTH;
403 #endif
404
405 /*
406 * Otherwise, we need to take the lock to decide, so don't
407 * reject just yet. Caller must serialize a call to
408 * sliwin_update in this case.
409 */
410 return 0;
411 }
412
413 static int
414 sliwin_update(struct sliwin *W, uint64_t S)
415 {
416 unsigned word, bit;
417
418 /*
419 * If it's more than one window older than the highest sequence
420 * number we've seen, reject.
421 */
422 if (S + SLIWIN_NPKT < W->T)
423 return EAUTH;
424
425 /*
426 * If it's higher than the highest sequence number we've seen,
427 * advance the window.
428 */
429 if (S > W->T) {
430 uint64_t i = W->T / SLIWIN_BPW;
431 uint64_t j = S / SLIWIN_BPW;
432 unsigned k;
433
434 for (k = 0; k < MIN(j - i, SLIWIN_WORDS); k++)
435 W->B[(i + k + 1) % SLIWIN_WORDS] = 0;
436 #ifdef __HAVE_ATOMIC64_LOADSTORE
437 atomic_store_relaxed(&W->T, S);
438 #else
439 W->T = S;
440 #endif
441 }
442
443 /* Test and set the bit -- if already set, reject. */
444 word = (S / SLIWIN_BPW) % SLIWIN_WORDS;
445 bit = S % SLIWIN_BPW;
446 if (W->B[word] & (1UL << bit))
447 return EAUTH;
448 W->B[word] |= 1U << bit;
449
450 /* Accept! */
451 return 0;
452 }
453
454 struct wg_session {
455 struct wg_peer *wgs_peer;
456 struct psref_target
457 wgs_psref;
458
459 int wgs_state;
460 #define WGS_STATE_UNKNOWN 0
461 #define WGS_STATE_INIT_ACTIVE 1
462 #define WGS_STATE_INIT_PASSIVE 2
463 #define WGS_STATE_ESTABLISHED 3
464 #define WGS_STATE_DESTROYING 4
465
466 time_t wgs_time_established;
467 time_t wgs_time_last_data_sent;
468 bool wgs_is_initiator;
469
470 uint32_t wgs_local_index;
471 uint32_t wgs_remote_index;
472 #ifdef __HAVE_ATOMIC64_LOADSTORE
473 volatile uint64_t
474 wgs_send_counter;
475 #else
476 kmutex_t wgs_send_counter_lock;
477 uint64_t wgs_send_counter;
478 #endif
479
480 struct {
481 kmutex_t lock;
482 struct sliwin window;
483 } *wgs_recvwin;
484
485 uint8_t wgs_handshake_hash[WG_HASH_LEN];
486 uint8_t wgs_chaining_key[WG_CHAINING_KEY_LEN];
487 uint8_t wgs_ephemeral_key_pub[WG_EPHEMERAL_KEY_LEN];
488 uint8_t wgs_ephemeral_key_priv[WG_EPHEMERAL_KEY_LEN];
489 uint8_t wgs_ephemeral_key_peer[WG_EPHEMERAL_KEY_LEN];
490 uint8_t wgs_tkey_send[WG_DATA_KEY_LEN];
491 uint8_t wgs_tkey_recv[WG_DATA_KEY_LEN];
492 };
493
494 struct wg_sockaddr {
495 union {
496 struct sockaddr_storage _ss;
497 struct sockaddr _sa;
498 struct sockaddr_in _sin;
499 struct sockaddr_in6 _sin6;
500 };
501 struct psref_target wgsa_psref;
502 };
503
504 #define wgsatoss(wgsa) (&(wgsa)->_ss)
505 #define wgsatosa(wgsa) (&(wgsa)->_sa)
506 #define wgsatosin(wgsa) (&(wgsa)->_sin)
507 #define wgsatosin6(wgsa) (&(wgsa)->_sin6)
508
509 #define wgsa_family(wgsa) (wgsatosa(wgsa)->sa_family)
510
511 struct wg_peer;
512 struct wg_allowedip {
513 struct radix_node wga_nodes[2];
514 struct wg_sockaddr _wga_sa_addr;
515 struct wg_sockaddr _wga_sa_mask;
516 #define wga_sa_addr _wga_sa_addr._sa
517 #define wga_sa_mask _wga_sa_mask._sa
518
519 int wga_family;
520 uint8_t wga_cidr;
521 union {
522 struct in_addr _ip4;
523 struct in6_addr _ip6;
524 } wga_addr;
525 #define wga_addr4 wga_addr._ip4
526 #define wga_addr6 wga_addr._ip6
527
528 struct wg_peer *wga_peer;
529 };
530
531 typedef uint8_t wg_timestamp_t[WG_TIMESTAMP_LEN];
532
533 struct wg_ppsratecheck {
534 struct timeval wgprc_lasttime;
535 int wgprc_curpps;
536 };
537
538 struct wg_softc;
539 struct wg_peer {
540 struct wg_softc *wgp_sc;
541 char wgp_name[WG_PEER_NAME_MAXLEN + 1];
542 struct pslist_entry wgp_peerlist_entry;
543 pserialize_t wgp_psz;
544 struct psref_target wgp_psref;
545 kmutex_t *wgp_lock;
546 kmutex_t *wgp_intr_lock;
547
548 uint8_t wgp_pubkey[WG_STATIC_KEY_LEN];
549 struct wg_sockaddr *wgp_endpoint;
550 struct wg_sockaddr *wgp_endpoint0;
551 volatile unsigned wgp_endpoint_changing;
552 bool wgp_endpoint_available;
553
554 /* The preshared key (optional) */
555 uint8_t wgp_psk[WG_PRESHARED_KEY_LEN];
556
557 struct wg_session *wgp_session_stable;
558 struct wg_session *wgp_session_unstable;
559
560 /* first outgoing packet awaiting session initiation */
561 struct mbuf *wgp_pending;
562
563 /* timestamp in big-endian */
564 wg_timestamp_t wgp_timestamp_latest_init;
565
566 struct timespec wgp_last_handshake_time;
567
568 callout_t wgp_rekey_timer;
569 callout_t wgp_handshake_timeout_timer;
570 callout_t wgp_session_dtor_timer;
571
572 time_t wgp_handshake_start_time;
573
574 int wgp_n_allowedips;
575 struct wg_allowedip wgp_allowedips[WG_ALLOWEDIPS];
576
577 time_t wgp_latest_cookie_time;
578 uint8_t wgp_latest_cookie[WG_COOKIE_LEN];
579 uint8_t wgp_last_sent_mac1[WG_MAC_LEN];
580 bool wgp_last_sent_mac1_valid;
581 uint8_t wgp_last_sent_cookie[WG_COOKIE_LEN];
582 bool wgp_last_sent_cookie_valid;
583
584 time_t wgp_last_msg_received_time[WG_MSG_TYPE_MAX];
585
586 time_t wgp_last_genrandval_time;
587 uint32_t wgp_randval;
588
589 struct wg_ppsratecheck wgp_ppsratecheck;
590
591 struct work wgp_work;
592 unsigned int wgp_tasks;
593 #define WGP_TASK_SEND_INIT_MESSAGE __BIT(0)
594 #define WGP_TASK_RETRY_HANDSHAKE __BIT(1)
595 #define WGP_TASK_ESTABLISH_SESSION __BIT(2)
596 #define WGP_TASK_ENDPOINT_CHANGED __BIT(3)
597 #define WGP_TASK_SEND_KEEPALIVE_MESSAGE __BIT(4)
598 #define WGP_TASK_DESTROY_PREV_SESSION __BIT(5)
599 };
600
601 struct wg_ops;
602
603 struct wg_softc {
604 struct ifnet wg_if;
605 LIST_ENTRY(wg_softc) wg_list;
606 kmutex_t *wg_lock;
607 kmutex_t *wg_intr_lock;
608 krwlock_t *wg_rwlock;
609
610 uint8_t wg_privkey[WG_STATIC_KEY_LEN];
611 uint8_t wg_pubkey[WG_STATIC_KEY_LEN];
612
613 int wg_npeers;
614 struct pslist_head wg_peers;
615 struct thmap *wg_peers_bypubkey;
616 struct thmap *wg_peers_byname;
617 struct thmap *wg_sessions_byindex;
618 uint16_t wg_listen_port;
619
620 struct threadpool *wg_threadpool;
621
622 struct threadpool_job wg_job;
623 int wg_upcalls;
624 #define WG_UPCALL_INET __BIT(0)
625 #define WG_UPCALL_INET6 __BIT(1)
626
627 #ifdef INET
628 struct socket *wg_so4;
629 struct radix_node_head *wg_rtable_ipv4;
630 #endif
631 #ifdef INET6
632 struct socket *wg_so6;
633 struct radix_node_head *wg_rtable_ipv6;
634 #endif
635
636 struct wg_ppsratecheck wg_ppsratecheck;
637
638 struct wg_ops *wg_ops;
639
640 #ifdef WG_RUMPKERNEL
641 struct wg_user *wg_user;
642 #endif
643 };
644
645 /* [W] 6.1 Preliminaries */
646 #define WG_REKEY_AFTER_MESSAGES (1ULL << 60)
647 #define WG_REJECT_AFTER_MESSAGES (UINT64_MAX - (1 << 13))
648 #define WG_REKEY_AFTER_TIME 120
649 #define WG_REJECT_AFTER_TIME 180
650 #define WG_REKEY_ATTEMPT_TIME 90
651 #define WG_REKEY_TIMEOUT 5
652 #define WG_KEEPALIVE_TIMEOUT 10
653
654 #define WG_COOKIE_TIME 120
655 #define WG_RANDVAL_TIME (2 * 60)
656
657 static uint64_t wg_rekey_after_messages = WG_REKEY_AFTER_MESSAGES;
658 static uint64_t wg_reject_after_messages = WG_REJECT_AFTER_MESSAGES;
659 static unsigned wg_rekey_after_time = WG_REKEY_AFTER_TIME;
660 static unsigned wg_reject_after_time = WG_REJECT_AFTER_TIME;
661 static unsigned wg_rekey_attempt_time = WG_REKEY_ATTEMPT_TIME;
662 static unsigned wg_rekey_timeout = WG_REKEY_TIMEOUT;
663 static unsigned wg_keepalive_timeout = WG_KEEPALIVE_TIMEOUT;
664
665 static struct mbuf *
666 wg_get_mbuf(size_t, size_t);
667
668 static int wg_send_data_msg(struct wg_peer *, struct wg_session *,
669 struct mbuf *);
670 static int wg_send_cookie_msg(struct wg_softc *, struct wg_peer *,
671 const uint32_t, const uint8_t [WG_MAC_LEN],
672 const struct sockaddr *);
673 static int wg_send_handshake_msg_resp(struct wg_softc *, struct wg_peer *,
674 struct wg_session *, const struct wg_msg_init *);
675 static void wg_send_keepalive_msg(struct wg_peer *, struct wg_session *);
676
677 static struct wg_peer *
678 wg_pick_peer_by_sa(struct wg_softc *, const struct sockaddr *,
679 struct psref *);
680 static struct wg_peer *
681 wg_lookup_peer_by_pubkey(struct wg_softc *,
682 const uint8_t [WG_STATIC_KEY_LEN], struct psref *);
683
684 static struct wg_session *
685 wg_lookup_session_by_index(struct wg_softc *,
686 const uint32_t, struct psref *);
687
688 static void wg_update_endpoint_if_necessary(struct wg_peer *,
689 const struct sockaddr *);
690
691 static void wg_schedule_rekey_timer(struct wg_peer *);
692 static void wg_schedule_session_dtor_timer(struct wg_peer *);
693
694 static bool wg_is_underload(struct wg_softc *, struct wg_peer *, int);
695 static void wg_calculate_keys(struct wg_session *, const bool);
696
697 static void wg_clear_states(struct wg_session *);
698
699 static void wg_get_peer(struct wg_peer *, struct psref *);
700 static void wg_put_peer(struct wg_peer *, struct psref *);
701
702 static int wg_send_so(struct wg_peer *, struct mbuf *);
703 static int wg_send_udp(struct wg_peer *, struct mbuf *);
704 static int wg_output(struct ifnet *, struct mbuf *,
705 const struct sockaddr *, const struct rtentry *);
706 static void wg_input(struct ifnet *, struct mbuf *, const int);
707 static int wg_ioctl(struct ifnet *, u_long, void *);
708 static int wg_bind_port(struct wg_softc *, const uint16_t);
709 static int wg_init(struct ifnet *);
710 #ifdef ALTQ
711 static void wg_start(struct ifnet *);
712 #endif
713 static void wg_stop(struct ifnet *, int);
714
715 static void wg_peer_work(struct work *, void *);
716 static void wg_job(struct threadpool_job *);
717 static void wgintr(void *);
718 static void wg_purge_pending_packets(struct wg_peer *);
719
720 static int wg_clone_create(struct if_clone *, int);
721 static int wg_clone_destroy(struct ifnet *);
722
723 struct wg_ops {
724 int (*send_hs_msg)(struct wg_peer *, struct mbuf *);
725 int (*send_data_msg)(struct wg_peer *, struct mbuf *);
726 void (*input)(struct ifnet *, struct mbuf *, const int);
727 int (*bind_port)(struct wg_softc *, const uint16_t);
728 };
729
730 struct wg_ops wg_ops_rumpkernel = {
731 .send_hs_msg = wg_send_so,
732 .send_data_msg = wg_send_udp,
733 .input = wg_input,
734 .bind_port = wg_bind_port,
735 };
736
737 #ifdef WG_RUMPKERNEL
738 static bool wg_user_mode(struct wg_softc *);
739 static int wg_ioctl_linkstr(struct wg_softc *, struct ifdrv *);
740
741 static int wg_send_user(struct wg_peer *, struct mbuf *);
742 static void wg_input_user(struct ifnet *, struct mbuf *, const int);
743 static int wg_bind_port_user(struct wg_softc *, const uint16_t);
744
745 struct wg_ops wg_ops_rumpuser = {
746 .send_hs_msg = wg_send_user,
747 .send_data_msg = wg_send_user,
748 .input = wg_input_user,
749 .bind_port = wg_bind_port_user,
750 };
751 #endif
752
753 #define WG_PEER_READER_FOREACH(wgp, wg) \
754 PSLIST_READER_FOREACH((wgp), &(wg)->wg_peers, struct wg_peer, \
755 wgp_peerlist_entry)
756 #define WG_PEER_WRITER_FOREACH(wgp, wg) \
757 PSLIST_WRITER_FOREACH((wgp), &(wg)->wg_peers, struct wg_peer, \
758 wgp_peerlist_entry)
759 #define WG_PEER_WRITER_INSERT_HEAD(wgp, wg) \
760 PSLIST_WRITER_INSERT_HEAD(&(wg)->wg_peers, (wgp), wgp_peerlist_entry)
761 #define WG_PEER_WRITER_REMOVE(wgp) \
762 PSLIST_WRITER_REMOVE((wgp), wgp_peerlist_entry)
763
764 struct wg_route {
765 struct radix_node wgr_nodes[2];
766 struct wg_peer *wgr_peer;
767 };
768
769 static struct radix_node_head *
770 wg_rnh(struct wg_softc *wg, const int family)
771 {
772
773 switch (family) {
774 case AF_INET:
775 return wg->wg_rtable_ipv4;
776 #ifdef INET6
777 case AF_INET6:
778 return wg->wg_rtable_ipv6;
779 #endif
780 default:
781 return NULL;
782 }
783 }
784
785
786 /*
787 * Global variables
788 */
789 static volatile unsigned wg_count __cacheline_aligned;
790
791 struct psref_class *wg_psref_class __read_mostly;
792
793 static struct if_clone wg_cloner =
794 IF_CLONE_INITIALIZER("wg", wg_clone_create, wg_clone_destroy);
795
796 static struct pktqueue *wg_pktq __read_mostly;
797 static struct workqueue *wg_wq __read_mostly;
798
799 void wgattach(int);
800 /* ARGSUSED */
801 void
802 wgattach(int count)
803 {
804 /*
805 * Nothing to do here, initialization is handled by the
806 * module initialization code in wginit() below).
807 */
808 }
809
810 static void
811 wginit(void)
812 {
813
814 wg_psref_class = psref_class_create("wg", IPL_SOFTNET);
815
816 if_clone_attach(&wg_cloner);
817 }
818
819 /*
820 * XXX Kludge: This should just happen in wginit, but workqueue_create
821 * cannot be run until after CPUs have been detected, and wginit runs
822 * before configure.
823 */
824 static int
825 wginitqueues(void)
826 {
827 int error __diagused;
828
829 wg_pktq = pktq_create(IFQ_MAXLEN, wgintr, NULL);
830 KASSERT(wg_pktq != NULL);
831
832 error = workqueue_create(&wg_wq, "wgpeer", wg_peer_work, NULL,
833 PRI_NONE, IPL_SOFTNET, WQ_MPSAFE|WQ_PERCPU);
834 KASSERT(error == 0);
835
836 return 0;
837 }
838
839 static void
840 wg_guarantee_initialized(void)
841 {
842 static ONCE_DECL(init);
843 int error __diagused;
844
845 error = RUN_ONCE(&init, wginitqueues);
846 KASSERT(error == 0);
847 }
848
849 static int
850 wg_count_inc(void)
851 {
852 unsigned o, n;
853
854 do {
855 o = atomic_load_relaxed(&wg_count);
856 if (o == UINT_MAX)
857 return ENFILE;
858 n = o + 1;
859 } while (atomic_cas_uint(&wg_count, o, n) != o);
860
861 return 0;
862 }
863
864 static void
865 wg_count_dec(void)
866 {
867 unsigned c __diagused;
868
869 c = atomic_dec_uint_nv(&wg_count);
870 KASSERT(c != UINT_MAX);
871 }
872
873 static int
874 wgdetach(void)
875 {
876
877 /* Prevent new interface creation. */
878 if_clone_detach(&wg_cloner);
879
880 /* Check whether there are any existing interfaces. */
881 if (atomic_load_relaxed(&wg_count)) {
882 /* Back out -- reattach the cloner. */
883 if_clone_attach(&wg_cloner);
884 return EBUSY;
885 }
886
887 /* No interfaces left. Nuke it. */
888 workqueue_destroy(wg_wq);
889 pktq_destroy(wg_pktq);
890 psref_class_destroy(wg_psref_class);
891
892 return 0;
893 }
894
895 static void
896 wg_init_key_and_hash(uint8_t ckey[WG_CHAINING_KEY_LEN],
897 uint8_t hash[WG_HASH_LEN])
898 {
899 /* [W] 5.4: CONSTRUCTION */
900 const char *signature = "Noise_IKpsk2_25519_ChaChaPoly_BLAKE2s";
901 /* [W] 5.4: IDENTIFIER */
902 const char *id = "WireGuard v1 zx2c4 Jason (at) zx2c4.com";
903 struct blake2s state;
904
905 blake2s(ckey, WG_CHAINING_KEY_LEN, NULL, 0,
906 signature, strlen(signature));
907
908 CTASSERT(WG_HASH_LEN == WG_CHAINING_KEY_LEN);
909 memcpy(hash, ckey, WG_CHAINING_KEY_LEN);
910
911 blake2s_init(&state, WG_HASH_LEN, NULL, 0);
912 blake2s_update(&state, ckey, WG_CHAINING_KEY_LEN);
913 blake2s_update(&state, id, strlen(id));
914 blake2s_final(&state, hash);
915
916 WG_DUMP_HASH("ckey", ckey);
917 WG_DUMP_HASH("hash", hash);
918 }
919
920 static void
921 wg_algo_hash(uint8_t hash[WG_HASH_LEN], const uint8_t input[],
922 const size_t inputsize)
923 {
924 struct blake2s state;
925
926 blake2s_init(&state, WG_HASH_LEN, NULL, 0);
927 blake2s_update(&state, hash, WG_HASH_LEN);
928 blake2s_update(&state, input, inputsize);
929 blake2s_final(&state, hash);
930 }
931
932 static void
933 wg_algo_mac(uint8_t out[], const size_t outsize,
934 const uint8_t key[], const size_t keylen,
935 const uint8_t input1[], const size_t input1len,
936 const uint8_t input2[], const size_t input2len)
937 {
938 struct blake2s state;
939
940 blake2s_init(&state, outsize, key, keylen);
941
942 blake2s_update(&state, input1, input1len);
943 if (input2 != NULL)
944 blake2s_update(&state, input2, input2len);
945 blake2s_final(&state, out);
946 }
947
948 static void
949 wg_algo_mac_mac1(uint8_t out[], const size_t outsize,
950 const uint8_t input1[], const size_t input1len,
951 const uint8_t input2[], const size_t input2len)
952 {
953 struct blake2s state;
954 /* [W] 5.4: LABEL-MAC1 */
955 const char *label = "mac1----";
956 uint8_t key[WG_HASH_LEN];
957
958 blake2s_init(&state, sizeof(key), NULL, 0);
959 blake2s_update(&state, label, strlen(label));
960 blake2s_update(&state, input1, input1len);
961 blake2s_final(&state, key);
962
963 blake2s_init(&state, outsize, key, sizeof(key));
964 if (input2 != NULL)
965 blake2s_update(&state, input2, input2len);
966 blake2s_final(&state, out);
967 }
968
969 static void
970 wg_algo_mac_cookie(uint8_t out[], const size_t outsize,
971 const uint8_t input1[], const size_t input1len)
972 {
973 struct blake2s state;
974 /* [W] 5.4: LABEL-COOKIE */
975 const char *label = "cookie--";
976
977 blake2s_init(&state, outsize, NULL, 0);
978 blake2s_update(&state, label, strlen(label));
979 blake2s_update(&state, input1, input1len);
980 blake2s_final(&state, out);
981 }
982
983 static void
984 wg_algo_generate_keypair(uint8_t pubkey[WG_EPHEMERAL_KEY_LEN],
985 uint8_t privkey[WG_EPHEMERAL_KEY_LEN])
986 {
987
988 CTASSERT(WG_EPHEMERAL_KEY_LEN == crypto_scalarmult_curve25519_BYTES);
989
990 cprng_strong(kern_cprng, privkey, WG_EPHEMERAL_KEY_LEN, 0);
991 crypto_scalarmult_base(pubkey, privkey);
992 }
993
994 static void
995 wg_algo_dh(uint8_t out[WG_DH_OUTPUT_LEN],
996 const uint8_t privkey[WG_STATIC_KEY_LEN],
997 const uint8_t pubkey[WG_STATIC_KEY_LEN])
998 {
999
1000 CTASSERT(WG_STATIC_KEY_LEN == crypto_scalarmult_curve25519_BYTES);
1001
1002 int ret __diagused = crypto_scalarmult(out, privkey, pubkey);
1003 KASSERT(ret == 0);
1004 }
1005
1006 static void
1007 wg_algo_hmac(uint8_t out[], const size_t outlen,
1008 const uint8_t key[], const size_t keylen,
1009 const uint8_t in[], const size_t inlen)
1010 {
1011 #define IPAD 0x36
1012 #define OPAD 0x5c
1013 uint8_t hmackey[HMAC_BLOCK_LEN] = {0};
1014 uint8_t ipad[HMAC_BLOCK_LEN];
1015 uint8_t opad[HMAC_BLOCK_LEN];
1016 size_t i;
1017 struct blake2s state;
1018
1019 KASSERT(outlen == WG_HASH_LEN);
1020 KASSERT(keylen <= HMAC_BLOCK_LEN);
1021
1022 memcpy(hmackey, key, keylen);
1023
1024 for (i = 0; i < sizeof(hmackey); i++) {
1025 ipad[i] = hmackey[i] ^ IPAD;
1026 opad[i] = hmackey[i] ^ OPAD;
1027 }
1028
1029 blake2s_init(&state, WG_HASH_LEN, NULL, 0);
1030 blake2s_update(&state, ipad, sizeof(ipad));
1031 blake2s_update(&state, in, inlen);
1032 blake2s_final(&state, out);
1033
1034 blake2s_init(&state, WG_HASH_LEN, NULL, 0);
1035 blake2s_update(&state, opad, sizeof(opad));
1036 blake2s_update(&state, out, WG_HASH_LEN);
1037 blake2s_final(&state, out);
1038 #undef IPAD
1039 #undef OPAD
1040 }
1041
1042 static void
1043 wg_algo_kdf(uint8_t out1[WG_KDF_OUTPUT_LEN], uint8_t out2[WG_KDF_OUTPUT_LEN],
1044 uint8_t out3[WG_KDF_OUTPUT_LEN], const uint8_t ckey[WG_CHAINING_KEY_LEN],
1045 const uint8_t input[], const size_t inputlen)
1046 {
1047 uint8_t tmp1[WG_KDF_OUTPUT_LEN], tmp2[WG_KDF_OUTPUT_LEN + 1];
1048 uint8_t one[1];
1049
1050 /*
1051 * [N] 4.3: "an input_key_material byte sequence with length
1052 * either zero bytes, 32 bytes, or DHLEN bytes."
1053 */
1054 KASSERT(inputlen == 0 || inputlen == 32 || inputlen == NOISE_DHLEN);
1055
1056 WG_DUMP_HASH("ckey", ckey);
1057 if (input != NULL)
1058 WG_DUMP_HASH("input", input);
1059 wg_algo_hmac(tmp1, sizeof(tmp1), ckey, WG_CHAINING_KEY_LEN,
1060 input, inputlen);
1061 WG_DUMP_HASH("tmp1", tmp1);
1062 one[0] = 1;
1063 wg_algo_hmac(out1, WG_KDF_OUTPUT_LEN, tmp1, sizeof(tmp1),
1064 one, sizeof(one));
1065 WG_DUMP_HASH("out1", out1);
1066 if (out2 == NULL)
1067 return;
1068 memcpy(tmp2, out1, WG_KDF_OUTPUT_LEN);
1069 tmp2[WG_KDF_OUTPUT_LEN] = 2;
1070 wg_algo_hmac(out2, WG_KDF_OUTPUT_LEN, tmp1, sizeof(tmp1),
1071 tmp2, sizeof(tmp2));
1072 WG_DUMP_HASH("out2", out2);
1073 if (out3 == NULL)
1074 return;
1075 memcpy(tmp2, out2, WG_KDF_OUTPUT_LEN);
1076 tmp2[WG_KDF_OUTPUT_LEN] = 3;
1077 wg_algo_hmac(out3, WG_KDF_OUTPUT_LEN, tmp1, sizeof(tmp1),
1078 tmp2, sizeof(tmp2));
1079 WG_DUMP_HASH("out3", out3);
1080 }
1081
1082 static void __noinline
1083 wg_algo_dh_kdf(uint8_t ckey[WG_CHAINING_KEY_LEN],
1084 uint8_t cipher_key[WG_CIPHER_KEY_LEN],
1085 const uint8_t local_key[WG_STATIC_KEY_LEN],
1086 const uint8_t remote_key[WG_STATIC_KEY_LEN])
1087 {
1088 uint8_t dhout[WG_DH_OUTPUT_LEN];
1089
1090 wg_algo_dh(dhout, local_key, remote_key);
1091 wg_algo_kdf(ckey, cipher_key, NULL, ckey, dhout, sizeof(dhout));
1092
1093 WG_DUMP_HASH("dhout", dhout);
1094 WG_DUMP_HASH("ckey", ckey);
1095 if (cipher_key != NULL)
1096 WG_DUMP_HASH("cipher_key", cipher_key);
1097 }
1098
1099 static void
1100 wg_algo_aead_enc(uint8_t out[], size_t expected_outsize, const uint8_t key[],
1101 const uint64_t counter, const uint8_t plain[], const size_t plainsize,
1102 const uint8_t auth[], size_t authlen)
1103 {
1104 uint8_t nonce[(32 + 64) / 8] = {0};
1105 long long unsigned int outsize;
1106 int error __diagused;
1107
1108 le64enc(&nonce[4], counter);
1109
1110 error = crypto_aead_chacha20poly1305_ietf_encrypt(out, &outsize, plain,
1111 plainsize, auth, authlen, NULL, nonce, key);
1112 KASSERT(error == 0);
1113 KASSERT(outsize == expected_outsize);
1114 }
1115
1116 static int
1117 wg_algo_aead_dec(uint8_t out[], size_t expected_outsize, const uint8_t key[],
1118 const uint64_t counter, const uint8_t encrypted[],
1119 const size_t encryptedsize, const uint8_t auth[], size_t authlen)
1120 {
1121 uint8_t nonce[(32 + 64) / 8] = {0};
1122 long long unsigned int outsize;
1123 int error;
1124
1125 le64enc(&nonce[4], counter);
1126
1127 error = crypto_aead_chacha20poly1305_ietf_decrypt(out, &outsize, NULL,
1128 encrypted, encryptedsize, auth, authlen, nonce, key);
1129 if (error == 0)
1130 KASSERT(outsize == expected_outsize);
1131 return error;
1132 }
1133
1134 static void
1135 wg_algo_xaead_enc(uint8_t out[], const size_t expected_outsize,
1136 const uint8_t key[], const uint8_t plain[], const size_t plainsize,
1137 const uint8_t auth[], size_t authlen,
1138 const uint8_t nonce[WG_SALT_LEN])
1139 {
1140 long long unsigned int outsize;
1141 int error __diagused;
1142
1143 CTASSERT(WG_SALT_LEN == crypto_aead_xchacha20poly1305_ietf_NPUBBYTES);
1144 error = crypto_aead_xchacha20poly1305_ietf_encrypt(out, &outsize,
1145 plain, plainsize, auth, authlen, NULL, nonce, key);
1146 KASSERT(error == 0);
1147 KASSERT(outsize == expected_outsize);
1148 }
1149
1150 static int
1151 wg_algo_xaead_dec(uint8_t out[], const size_t expected_outsize,
1152 const uint8_t key[], const uint8_t encrypted[], const size_t encryptedsize,
1153 const uint8_t auth[], size_t authlen,
1154 const uint8_t nonce[WG_SALT_LEN])
1155 {
1156 long long unsigned int outsize;
1157 int error;
1158
1159 error = crypto_aead_xchacha20poly1305_ietf_decrypt(out, &outsize, NULL,
1160 encrypted, encryptedsize, auth, authlen, nonce, key);
1161 if (error == 0)
1162 KASSERT(outsize == expected_outsize);
1163 return error;
1164 }
1165
1166 static void
1167 wg_algo_tai64n(wg_timestamp_t timestamp)
1168 {
1169 struct timespec ts;
1170
1171 /* FIXME strict TAI64N (https://cr.yp.to/libtai/tai64.html) */
1172 getnanotime(&ts);
1173 /* TAI64 label in external TAI64 format */
1174 be32enc(timestamp, 0x40000000U + (uint32_t)(ts.tv_sec >> 32));
1175 /* second beginning from 1970 TAI */
1176 be32enc(timestamp + 4, (uint32_t)(ts.tv_sec & 0xffffffffU));
1177 /* nanosecond in big-endian format */
1178 be32enc(timestamp + 8, (uint32_t)ts.tv_nsec);
1179 }
1180
1181 /*
1182 * wg_get_stable_session(wgp, psref)
1183 *
1184 * Get a passive reference to the current stable session, or
1185 * return NULL if there is no current stable session.
1186 *
1187 * The pointer is always there but the session is not necessarily
1188 * ESTABLISHED; if it is not ESTABLISHED, return NULL. However,
1189 * the session may transition from ESTABLISHED to DESTROYING while
1190 * holding the passive reference.
1191 */
1192 static struct wg_session *
1193 wg_get_stable_session(struct wg_peer *wgp, struct psref *psref)
1194 {
1195 int s;
1196 struct wg_session *wgs;
1197
1198 s = pserialize_read_enter();
1199 wgs = atomic_load_consume(&wgp->wgp_session_stable);
1200 if (__predict_false(wgs->wgs_state != WGS_STATE_ESTABLISHED))
1201 wgs = NULL;
1202 else
1203 psref_acquire(psref, &wgs->wgs_psref, wg_psref_class);
1204 pserialize_read_exit(s);
1205
1206 return wgs;
1207 }
1208
1209 static void
1210 wg_put_session(struct wg_session *wgs, struct psref *psref)
1211 {
1212
1213 psref_release(psref, &wgs->wgs_psref, wg_psref_class);
1214 }
1215
1216 static void
1217 wg_destroy_session(struct wg_softc *wg, struct wg_session *wgs)
1218 {
1219 struct wg_peer *wgp = wgs->wgs_peer;
1220 struct wg_session *wgs0 __diagused;
1221 void *garbage;
1222
1223 KASSERT(mutex_owned(wgp->wgp_lock));
1224 KASSERT(wgs->wgs_state != WGS_STATE_UNKNOWN);
1225
1226 /* Remove the session from the table. */
1227 wgs0 = thmap_del(wg->wg_sessions_byindex,
1228 &wgs->wgs_local_index, sizeof(wgs->wgs_local_index));
1229 KASSERT(wgs0 == wgs);
1230 garbage = thmap_stage_gc(wg->wg_sessions_byindex);
1231
1232 /* Wait for passive references to drain. */
1233 pserialize_perform(wgp->wgp_psz);
1234 psref_target_destroy(&wgs->wgs_psref, wg_psref_class);
1235
1236 /* Free memory, zero state, and transition to UNKNOWN. */
1237 thmap_gc(wg->wg_sessions_byindex, garbage);
1238 wg_clear_states(wgs);
1239 wgs->wgs_state = WGS_STATE_UNKNOWN;
1240 }
1241
1242 /*
1243 * wg_get_session_index(wg, wgs)
1244 *
1245 * Choose a session index for wgs->wgs_local_index, and store it
1246 * in wg's table of sessions by index.
1247 *
1248 * wgs must be the unstable session of its peer, and must be
1249 * transitioning out of the UNKNOWN state.
1250 */
1251 static void
1252 wg_get_session_index(struct wg_softc *wg, struct wg_session *wgs)
1253 {
1254 struct wg_peer *wgp __diagused = wgs->wgs_peer;
1255 struct wg_session *wgs0;
1256 uint32_t index;
1257
1258 KASSERT(mutex_owned(wgp->wgp_lock));
1259 KASSERT(wgs == wgp->wgp_session_unstable);
1260 KASSERT(wgs->wgs_state == WGS_STATE_UNKNOWN);
1261
1262 do {
1263 /* Pick a uniform random index. */
1264 index = cprng_strong32();
1265
1266 /* Try to take it. */
1267 wgs->wgs_local_index = index;
1268 wgs0 = thmap_put(wg->wg_sessions_byindex,
1269 &wgs->wgs_local_index, sizeof wgs->wgs_local_index, wgs);
1270
1271 /* If someone else beat us, start over. */
1272 } while (__predict_false(wgs0 != wgs));
1273 }
1274
1275 /*
1276 * wg_put_session_index(wg, wgs)
1277 *
1278 * Remove wgs from the table of sessions by index, wait for any
1279 * passive references to drain, and transition the session to the
1280 * UNKNOWN state.
1281 *
1282 * wgs must be the unstable session of its peer, and must not be
1283 * UNKNOWN or ESTABLISHED.
1284 */
1285 static void
1286 wg_put_session_index(struct wg_softc *wg, struct wg_session *wgs)
1287 {
1288 struct wg_peer *wgp __diagused = wgs->wgs_peer;
1289
1290 KASSERT(mutex_owned(wgp->wgp_lock));
1291 KASSERT(wgs == wgp->wgp_session_unstable);
1292 KASSERT(wgs->wgs_state != WGS_STATE_UNKNOWN);
1293 KASSERT(wgs->wgs_state != WGS_STATE_ESTABLISHED);
1294
1295 wg_destroy_session(wg, wgs);
1296 psref_target_init(&wgs->wgs_psref, wg_psref_class);
1297 }
1298
1299 /*
1300 * Handshake patterns
1301 *
1302 * [W] 5: "These messages use the "IK" pattern from Noise"
1303 * [N] 7.5. Interactive handshake patterns (fundamental)
1304 * "The first character refers to the initiators static key:"
1305 * "I = Static key for initiator Immediately transmitted to responder,
1306 * despite reduced or absent identity hiding"
1307 * "The second character refers to the responders static key:"
1308 * "K = Static key for responder Known to initiator"
1309 * "IK:
1310 * <- s
1311 * ...
1312 * -> e, es, s, ss
1313 * <- e, ee, se"
1314 * [N] 9.4. Pattern modifiers
1315 * "IKpsk2:
1316 * <- s
1317 * ...
1318 * -> e, es, s, ss
1319 * <- e, ee, se, psk"
1320 */
1321 static void
1322 wg_fill_msg_init(struct wg_softc *wg, struct wg_peer *wgp,
1323 struct wg_session *wgs, struct wg_msg_init *wgmi)
1324 {
1325 uint8_t ckey[WG_CHAINING_KEY_LEN]; /* [W] 5.4.2: Ci */
1326 uint8_t hash[WG_HASH_LEN]; /* [W] 5.4.2: Hi */
1327 uint8_t cipher_key[WG_CIPHER_KEY_LEN];
1328 uint8_t pubkey[WG_EPHEMERAL_KEY_LEN];
1329 uint8_t privkey[WG_EPHEMERAL_KEY_LEN];
1330
1331 KASSERT(mutex_owned(wgp->wgp_lock));
1332 KASSERT(wgs == wgp->wgp_session_unstable);
1333 KASSERT(wgs->wgs_state == WGS_STATE_INIT_ACTIVE);
1334
1335 wgmi->wgmi_type = htole32(WG_MSG_TYPE_INIT);
1336 wgmi->wgmi_sender = wgs->wgs_local_index;
1337
1338 /* [W] 5.4.2: First Message: Initiator to Responder */
1339
1340 /* Ci := HASH(CONSTRUCTION) */
1341 /* Hi := HASH(Ci || IDENTIFIER) */
1342 wg_init_key_and_hash(ckey, hash);
1343 /* Hi := HASH(Hi || Sr^pub) */
1344 wg_algo_hash(hash, wgp->wgp_pubkey, sizeof(wgp->wgp_pubkey));
1345
1346 WG_DUMP_HASH("hash", hash);
1347
1348 /* [N] 2.2: "e" */
1349 /* Ei^priv, Ei^pub := DH-GENERATE() */
1350 wg_algo_generate_keypair(pubkey, privkey);
1351 /* Ci := KDF1(Ci, Ei^pub) */
1352 wg_algo_kdf(ckey, NULL, NULL, ckey, pubkey, sizeof(pubkey));
1353 /* msg.ephemeral := Ei^pub */
1354 memcpy(wgmi->wgmi_ephemeral, pubkey, sizeof(wgmi->wgmi_ephemeral));
1355 /* Hi := HASH(Hi || msg.ephemeral) */
1356 wg_algo_hash(hash, pubkey, sizeof(pubkey));
1357
1358 WG_DUMP_HASH("ckey", ckey);
1359 WG_DUMP_HASH("hash", hash);
1360
1361 /* [N] 2.2: "es" */
1362 /* Ci, k := KDF2(Ci, DH(Ei^priv, Sr^pub)) */
1363 wg_algo_dh_kdf(ckey, cipher_key, privkey, wgp->wgp_pubkey);
1364
1365 /* [N] 2.2: "s" */
1366 /* msg.static := AEAD(k, 0, Si^pub, Hi) */
1367 wg_algo_aead_enc(wgmi->wgmi_static, sizeof(wgmi->wgmi_static),
1368 cipher_key, 0, wg->wg_pubkey, sizeof(wg->wg_pubkey),
1369 hash, sizeof(hash));
1370 /* Hi := HASH(Hi || msg.static) */
1371 wg_algo_hash(hash, wgmi->wgmi_static, sizeof(wgmi->wgmi_static));
1372
1373 WG_DUMP_HASH48("wgmi_static", wgmi->wgmi_static);
1374
1375 /* [N] 2.2: "ss" */
1376 /* Ci, k := KDF2(Ci, DH(Si^priv, Sr^pub)) */
1377 wg_algo_dh_kdf(ckey, cipher_key, wg->wg_privkey, wgp->wgp_pubkey);
1378
1379 /* msg.timestamp := AEAD(k, TIMESTAMP(), Hi) */
1380 wg_timestamp_t timestamp;
1381 wg_algo_tai64n(timestamp);
1382 wg_algo_aead_enc(wgmi->wgmi_timestamp, sizeof(wgmi->wgmi_timestamp),
1383 cipher_key, 0, timestamp, sizeof(timestamp), hash, sizeof(hash));
1384 /* Hi := HASH(Hi || msg.timestamp) */
1385 wg_algo_hash(hash, wgmi->wgmi_timestamp, sizeof(wgmi->wgmi_timestamp));
1386
1387 /* [W] 5.4.4 Cookie MACs */
1388 wg_algo_mac_mac1(wgmi->wgmi_mac1, sizeof(wgmi->wgmi_mac1),
1389 wgp->wgp_pubkey, sizeof(wgp->wgp_pubkey),
1390 (const uint8_t *)wgmi, offsetof(struct wg_msg_init, wgmi_mac1));
1391 /* Need mac1 to decrypt a cookie from a cookie message */
1392 memcpy(wgp->wgp_last_sent_mac1, wgmi->wgmi_mac1,
1393 sizeof(wgp->wgp_last_sent_mac1));
1394 wgp->wgp_last_sent_mac1_valid = true;
1395
1396 if (wgp->wgp_latest_cookie_time == 0 ||
1397 (time_uptime - wgp->wgp_latest_cookie_time) >= WG_COOKIE_TIME)
1398 memset(wgmi->wgmi_mac2, 0, sizeof(wgmi->wgmi_mac2));
1399 else {
1400 wg_algo_mac(wgmi->wgmi_mac2, sizeof(wgmi->wgmi_mac2),
1401 wgp->wgp_latest_cookie, WG_COOKIE_LEN,
1402 (const uint8_t *)wgmi,
1403 offsetof(struct wg_msg_init, wgmi_mac2),
1404 NULL, 0);
1405 }
1406
1407 memcpy(wgs->wgs_ephemeral_key_pub, pubkey, sizeof(pubkey));
1408 memcpy(wgs->wgs_ephemeral_key_priv, privkey, sizeof(privkey));
1409 memcpy(wgs->wgs_handshake_hash, hash, sizeof(hash));
1410 memcpy(wgs->wgs_chaining_key, ckey, sizeof(ckey));
1411 WG_DLOG("%s: sender=%x\n", __func__, wgs->wgs_local_index);
1412 }
1413
1414 static void __noinline
1415 wg_handle_msg_init(struct wg_softc *wg, const struct wg_msg_init *wgmi,
1416 const struct sockaddr *src)
1417 {
1418 uint8_t ckey[WG_CHAINING_KEY_LEN]; /* [W] 5.4.2: Ci */
1419 uint8_t hash[WG_HASH_LEN]; /* [W] 5.4.2: Hi */
1420 uint8_t cipher_key[WG_CIPHER_KEY_LEN];
1421 uint8_t peer_pubkey[WG_STATIC_KEY_LEN];
1422 struct wg_peer *wgp;
1423 struct wg_session *wgs;
1424 int error, ret;
1425 struct psref psref_peer;
1426 uint8_t mac1[WG_MAC_LEN];
1427
1428 WG_TRACE("init msg received");
1429
1430 wg_algo_mac_mac1(mac1, sizeof(mac1),
1431 wg->wg_pubkey, sizeof(wg->wg_pubkey),
1432 (const uint8_t *)wgmi, offsetof(struct wg_msg_init, wgmi_mac1));
1433
1434 /*
1435 * [W] 5.3: Denial of Service Mitigation & Cookies
1436 * "the responder, ..., must always reject messages with an invalid
1437 * msg.mac1"
1438 */
1439 if (!consttime_memequal(mac1, wgmi->wgmi_mac1, sizeof(mac1))) {
1440 WG_DLOG("mac1 is invalid\n");
1441 return;
1442 }
1443
1444 /*
1445 * [W] 5.4.2: First Message: Initiator to Responder
1446 * "When the responder receives this message, it does the same
1447 * operations so that its final state variables are identical,
1448 * replacing the operands of the DH function to produce equivalent
1449 * values."
1450 * Note that the following comments of operations are just copies of
1451 * the initiator's ones.
1452 */
1453
1454 /* Ci := HASH(CONSTRUCTION) */
1455 /* Hi := HASH(Ci || IDENTIFIER) */
1456 wg_init_key_and_hash(ckey, hash);
1457 /* Hi := HASH(Hi || Sr^pub) */
1458 wg_algo_hash(hash, wg->wg_pubkey, sizeof(wg->wg_pubkey));
1459
1460 /* [N] 2.2: "e" */
1461 /* Ci := KDF1(Ci, Ei^pub) */
1462 wg_algo_kdf(ckey, NULL, NULL, ckey, wgmi->wgmi_ephemeral,
1463 sizeof(wgmi->wgmi_ephemeral));
1464 /* Hi := HASH(Hi || msg.ephemeral) */
1465 wg_algo_hash(hash, wgmi->wgmi_ephemeral, sizeof(wgmi->wgmi_ephemeral));
1466
1467 WG_DUMP_HASH("ckey", ckey);
1468
1469 /* [N] 2.2: "es" */
1470 /* Ci, k := KDF2(Ci, DH(Ei^priv, Sr^pub)) */
1471 wg_algo_dh_kdf(ckey, cipher_key, wg->wg_privkey, wgmi->wgmi_ephemeral);
1472
1473 WG_DUMP_HASH48("wgmi_static", wgmi->wgmi_static);
1474
1475 /* [N] 2.2: "s" */
1476 /* msg.static := AEAD(k, 0, Si^pub, Hi) */
1477 error = wg_algo_aead_dec(peer_pubkey, WG_STATIC_KEY_LEN, cipher_key, 0,
1478 wgmi->wgmi_static, sizeof(wgmi->wgmi_static), hash, sizeof(hash));
1479 if (error != 0) {
1480 WG_LOG_RATECHECK(&wg->wg_ppsratecheck, LOG_DEBUG,
1481 "%s: wg_algo_aead_dec for secret key failed\n",
1482 if_name(&wg->wg_if));
1483 return;
1484 }
1485 /* Hi := HASH(Hi || msg.static) */
1486 wg_algo_hash(hash, wgmi->wgmi_static, sizeof(wgmi->wgmi_static));
1487
1488 wgp = wg_lookup_peer_by_pubkey(wg, peer_pubkey, &psref_peer);
1489 if (wgp == NULL) {
1490 WG_DLOG("peer not found\n");
1491 return;
1492 }
1493
1494 /*
1495 * Lock the peer to serialize access to cookie state.
1496 *
1497 * XXX Can we safely avoid holding the lock across DH? Take it
1498 * just to verify mac2 and then unlock/DH/lock?
1499 */
1500 mutex_enter(wgp->wgp_lock);
1501
1502 if (__predict_false(wg_is_underload(wg, wgp, WG_MSG_TYPE_INIT))) {
1503 WG_TRACE("under load");
1504 /*
1505 * [W] 5.3: Denial of Service Mitigation & Cookies
1506 * "the responder, ..., and when under load may reject messages
1507 * with an invalid msg.mac2. If the responder receives a
1508 * message with a valid msg.mac1 yet with an invalid msg.mac2,
1509 * and is under load, it may respond with a cookie reply
1510 * message"
1511 */
1512 uint8_t zero[WG_MAC_LEN] = {0};
1513 if (consttime_memequal(wgmi->wgmi_mac2, zero, sizeof(zero))) {
1514 WG_TRACE("sending a cookie message: no cookie included");
1515 (void)wg_send_cookie_msg(wg, wgp, wgmi->wgmi_sender,
1516 wgmi->wgmi_mac1, src);
1517 goto out;
1518 }
1519 if (!wgp->wgp_last_sent_cookie_valid) {
1520 WG_TRACE("sending a cookie message: no cookie sent ever");
1521 (void)wg_send_cookie_msg(wg, wgp, wgmi->wgmi_sender,
1522 wgmi->wgmi_mac1, src);
1523 goto out;
1524 }
1525 uint8_t mac2[WG_MAC_LEN];
1526 wg_algo_mac(mac2, sizeof(mac2), wgp->wgp_last_sent_cookie,
1527 WG_COOKIE_LEN, (const uint8_t *)wgmi,
1528 offsetof(struct wg_msg_init, wgmi_mac2), NULL, 0);
1529 if (!consttime_memequal(mac2, wgmi->wgmi_mac2, sizeof(mac2))) {
1530 WG_DLOG("mac2 is invalid\n");
1531 goto out;
1532 }
1533 WG_TRACE("under load, but continue to sending");
1534 }
1535
1536 /* [N] 2.2: "ss" */
1537 /* Ci, k := KDF2(Ci, DH(Si^priv, Sr^pub)) */
1538 wg_algo_dh_kdf(ckey, cipher_key, wg->wg_privkey, wgp->wgp_pubkey);
1539
1540 /* msg.timestamp := AEAD(k, TIMESTAMP(), Hi) */
1541 wg_timestamp_t timestamp;
1542 error = wg_algo_aead_dec(timestamp, sizeof(timestamp), cipher_key, 0,
1543 wgmi->wgmi_timestamp, sizeof(wgmi->wgmi_timestamp),
1544 hash, sizeof(hash));
1545 if (error != 0) {
1546 WG_LOG_RATECHECK(&wgp->wgp_ppsratecheck, LOG_DEBUG,
1547 "%s: peer %s: wg_algo_aead_dec for timestamp failed\n",
1548 if_name(&wg->wg_if), wgp->wgp_name);
1549 goto out;
1550 }
1551 /* Hi := HASH(Hi || msg.timestamp) */
1552 wg_algo_hash(hash, wgmi->wgmi_timestamp, sizeof(wgmi->wgmi_timestamp));
1553
1554 /*
1555 * [W] 5.1 "The responder keeps track of the greatest timestamp
1556 * received per peer and discards packets containing
1557 * timestamps less than or equal to it."
1558 */
1559 ret = memcmp(timestamp, wgp->wgp_timestamp_latest_init,
1560 sizeof(timestamp));
1561 if (ret <= 0) {
1562 WG_LOG_RATECHECK(&wgp->wgp_ppsratecheck, LOG_DEBUG,
1563 "%s: peer %s: invalid init msg: timestamp is old\n",
1564 if_name(&wg->wg_if), wgp->wgp_name);
1565 goto out;
1566 }
1567 memcpy(wgp->wgp_timestamp_latest_init, timestamp, sizeof(timestamp));
1568
1569 /*
1570 * Message is good -- we're committing to handle it now, unless
1571 * we were already initiating a session.
1572 */
1573 wgs = wgp->wgp_session_unstable;
1574 switch (wgs->wgs_state) {
1575 case WGS_STATE_UNKNOWN: /* new session initiated by peer */
1576 wg_get_session_index(wg, wgs);
1577 break;
1578 case WGS_STATE_INIT_ACTIVE: /* we're already initiating, drop */
1579 WG_TRACE("Session already initializing, ignoring the message");
1580 goto out;
1581 case WGS_STATE_INIT_PASSIVE: /* peer is retrying, start over */
1582 WG_TRACE("Session already initializing, destroying old states");
1583 wg_clear_states(wgs);
1584 /* keep session index */
1585 break;
1586 case WGS_STATE_ESTABLISHED: /* can't happen */
1587 panic("unstable session can't be established");
1588 break;
1589 case WGS_STATE_DESTROYING: /* rekey initiated by peer */
1590 WG_TRACE("Session destroying, but force to clear");
1591 callout_stop(&wgp->wgp_session_dtor_timer);
1592 wg_clear_states(wgs);
1593 /* keep session index */
1594 break;
1595 default:
1596 panic("invalid session state: %d", wgs->wgs_state);
1597 }
1598 wgs->wgs_state = WGS_STATE_INIT_PASSIVE;
1599
1600 memcpy(wgs->wgs_handshake_hash, hash, sizeof(hash));
1601 memcpy(wgs->wgs_chaining_key, ckey, sizeof(ckey));
1602 memcpy(wgs->wgs_ephemeral_key_peer, wgmi->wgmi_ephemeral,
1603 sizeof(wgmi->wgmi_ephemeral));
1604
1605 wg_update_endpoint_if_necessary(wgp, src);
1606
1607 (void)wg_send_handshake_msg_resp(wg, wgp, wgs, wgmi);
1608
1609 wg_calculate_keys(wgs, false);
1610 wg_clear_states(wgs);
1611
1612 out:
1613 mutex_exit(wgp->wgp_lock);
1614 wg_put_peer(wgp, &psref_peer);
1615 }
1616
1617 static struct socket *
1618 wg_get_so_by_af(struct wg_softc *wg, const int af)
1619 {
1620
1621 switch (af) {
1622 #ifdef INET
1623 case AF_INET:
1624 return wg->wg_so4;
1625 #endif
1626 #ifdef INET6
1627 case AF_INET6:
1628 return wg->wg_so6;
1629 #endif
1630 default:
1631 panic("wg: no such af: %d", af);
1632 }
1633 }
1634
1635 static struct socket *
1636 wg_get_so_by_peer(struct wg_peer *wgp, struct wg_sockaddr *wgsa)
1637 {
1638
1639 return wg_get_so_by_af(wgp->wgp_sc, wgsa_family(wgsa));
1640 }
1641
1642 static struct wg_sockaddr *
1643 wg_get_endpoint_sa(struct wg_peer *wgp, struct psref *psref)
1644 {
1645 struct wg_sockaddr *wgsa;
1646 int s;
1647
1648 s = pserialize_read_enter();
1649 wgsa = atomic_load_consume(&wgp->wgp_endpoint);
1650 psref_acquire(psref, &wgsa->wgsa_psref, wg_psref_class);
1651 pserialize_read_exit(s);
1652
1653 return wgsa;
1654 }
1655
1656 static void
1657 wg_put_sa(struct wg_peer *wgp, struct wg_sockaddr *wgsa, struct psref *psref)
1658 {
1659
1660 psref_release(psref, &wgsa->wgsa_psref, wg_psref_class);
1661 }
1662
1663 static int
1664 wg_send_so(struct wg_peer *wgp, struct mbuf *m)
1665 {
1666 int error;
1667 struct socket *so;
1668 struct psref psref;
1669 struct wg_sockaddr *wgsa;
1670
1671 wgsa = wg_get_endpoint_sa(wgp, &psref);
1672 so = wg_get_so_by_peer(wgp, wgsa);
1673 error = sosend(so, wgsatosa(wgsa), NULL, m, NULL, 0, curlwp);
1674 wg_put_sa(wgp, wgsa, &psref);
1675
1676 return error;
1677 }
1678
1679 static int
1680 wg_send_handshake_msg_init(struct wg_softc *wg, struct wg_peer *wgp)
1681 {
1682 int error;
1683 struct mbuf *m;
1684 struct wg_msg_init *wgmi;
1685 struct wg_session *wgs;
1686
1687 KASSERT(mutex_owned(wgp->wgp_lock));
1688
1689 wgs = wgp->wgp_session_unstable;
1690 /* XXX pull dispatch out into wg_task_send_init_message */
1691 switch (wgs->wgs_state) {
1692 case WGS_STATE_UNKNOWN: /* new session initiated by us */
1693 wg_get_session_index(wg, wgs);
1694 break;
1695 case WGS_STATE_INIT_ACTIVE: /* we're already initiating, stop */
1696 WG_TRACE("Session already initializing, skip starting new one");
1697 return EBUSY;
1698 case WGS_STATE_INIT_PASSIVE: /* peer was trying -- XXX what now? */
1699 WG_TRACE("Session already initializing, destroying old states");
1700 wg_clear_states(wgs);
1701 /* keep session index */
1702 break;
1703 case WGS_STATE_ESTABLISHED: /* can't happen */
1704 panic("unstable session can't be established");
1705 break;
1706 case WGS_STATE_DESTROYING: /* rekey initiated by us too early */
1707 WG_TRACE("Session destroying");
1708 /* XXX should wait? */
1709 return EBUSY;
1710 }
1711 wgs->wgs_state = WGS_STATE_INIT_ACTIVE;
1712
1713 m = m_gethdr(M_WAIT, MT_DATA);
1714 if (sizeof(*wgmi) > MHLEN) {
1715 m_clget(m, M_WAIT);
1716 CTASSERT(sizeof(*wgmi) <= MCLBYTES);
1717 }
1718 m->m_pkthdr.len = m->m_len = sizeof(*wgmi);
1719 wgmi = mtod(m, struct wg_msg_init *);
1720 wg_fill_msg_init(wg, wgp, wgs, wgmi);
1721
1722 error = wg->wg_ops->send_hs_msg(wgp, m);
1723 if (error == 0) {
1724 WG_TRACE("init msg sent");
1725
1726 if (wgp->wgp_handshake_start_time == 0)
1727 wgp->wgp_handshake_start_time = time_uptime;
1728 callout_schedule(&wgp->wgp_handshake_timeout_timer,
1729 MIN(wg_rekey_timeout, (unsigned)(INT_MAX / hz)) * hz);
1730 } else {
1731 wg_put_session_index(wg, wgs);
1732 /* Initiation failed; toss packet waiting for it if any. */
1733 if ((m = atomic_swap_ptr(&wgp->wgp_pending, NULL)) != NULL)
1734 m_freem(m);
1735 }
1736
1737 return error;
1738 }
1739
1740 static void
1741 wg_fill_msg_resp(struct wg_softc *wg, struct wg_peer *wgp,
1742 struct wg_session *wgs, struct wg_msg_resp *wgmr,
1743 const struct wg_msg_init *wgmi)
1744 {
1745 uint8_t ckey[WG_CHAINING_KEY_LEN]; /* [W] 5.4.3: Cr */
1746 uint8_t hash[WG_HASH_LEN]; /* [W] 5.4.3: Hr */
1747 uint8_t cipher_key[WG_KDF_OUTPUT_LEN];
1748 uint8_t pubkey[WG_EPHEMERAL_KEY_LEN];
1749 uint8_t privkey[WG_EPHEMERAL_KEY_LEN];
1750
1751 KASSERT(mutex_owned(wgp->wgp_lock));
1752 KASSERT(wgs == wgp->wgp_session_unstable);
1753 KASSERT(wgs->wgs_state == WGS_STATE_INIT_PASSIVE);
1754
1755 memcpy(hash, wgs->wgs_handshake_hash, sizeof(hash));
1756 memcpy(ckey, wgs->wgs_chaining_key, sizeof(ckey));
1757
1758 wgmr->wgmr_type = htole32(WG_MSG_TYPE_RESP);
1759 wgmr->wgmr_sender = wgs->wgs_local_index;
1760 wgmr->wgmr_receiver = wgmi->wgmi_sender;
1761
1762 /* [W] 5.4.3 Second Message: Responder to Initiator */
1763
1764 /* [N] 2.2: "e" */
1765 /* Er^priv, Er^pub := DH-GENERATE() */
1766 wg_algo_generate_keypair(pubkey, privkey);
1767 /* Cr := KDF1(Cr, Er^pub) */
1768 wg_algo_kdf(ckey, NULL, NULL, ckey, pubkey, sizeof(pubkey));
1769 /* msg.ephemeral := Er^pub */
1770 memcpy(wgmr->wgmr_ephemeral, pubkey, sizeof(wgmr->wgmr_ephemeral));
1771 /* Hr := HASH(Hr || msg.ephemeral) */
1772 wg_algo_hash(hash, pubkey, sizeof(pubkey));
1773
1774 WG_DUMP_HASH("ckey", ckey);
1775 WG_DUMP_HASH("hash", hash);
1776
1777 /* [N] 2.2: "ee" */
1778 /* Cr := KDF1(Cr, DH(Er^priv, Ei^pub)) */
1779 wg_algo_dh_kdf(ckey, NULL, privkey, wgs->wgs_ephemeral_key_peer);
1780
1781 /* [N] 2.2: "se" */
1782 /* Cr := KDF1(Cr, DH(Er^priv, Si^pub)) */
1783 wg_algo_dh_kdf(ckey, NULL, privkey, wgp->wgp_pubkey);
1784
1785 /* [N] 9.2: "psk" */
1786 {
1787 uint8_t kdfout[WG_KDF_OUTPUT_LEN];
1788 /* Cr, r, k := KDF3(Cr, Q) */
1789 wg_algo_kdf(ckey, kdfout, cipher_key, ckey, wgp->wgp_psk,
1790 sizeof(wgp->wgp_psk));
1791 /* Hr := HASH(Hr || r) */
1792 wg_algo_hash(hash, kdfout, sizeof(kdfout));
1793 }
1794
1795 /* msg.empty := AEAD(k, 0, e, Hr) */
1796 wg_algo_aead_enc(wgmr->wgmr_empty, sizeof(wgmr->wgmr_empty),
1797 cipher_key, 0, NULL, 0, hash, sizeof(hash));
1798 /* Hr := HASH(Hr || msg.empty) */
1799 wg_algo_hash(hash, wgmr->wgmr_empty, sizeof(wgmr->wgmr_empty));
1800
1801 WG_DUMP_HASH("wgmr_empty", wgmr->wgmr_empty);
1802
1803 /* [W] 5.4.4: Cookie MACs */
1804 /* msg.mac1 := MAC(HASH(LABEL-MAC1 || Sm'^pub), msg_a) */
1805 wg_algo_mac_mac1(wgmr->wgmr_mac1, sizeof(wgmi->wgmi_mac1),
1806 wgp->wgp_pubkey, sizeof(wgp->wgp_pubkey),
1807 (const uint8_t *)wgmr, offsetof(struct wg_msg_resp, wgmr_mac1));
1808 /* Need mac1 to decrypt a cookie from a cookie message */
1809 memcpy(wgp->wgp_last_sent_mac1, wgmr->wgmr_mac1,
1810 sizeof(wgp->wgp_last_sent_mac1));
1811 wgp->wgp_last_sent_mac1_valid = true;
1812
1813 if (wgp->wgp_latest_cookie_time == 0 ||
1814 (time_uptime - wgp->wgp_latest_cookie_time) >= WG_COOKIE_TIME)
1815 /* msg.mac2 := 0^16 */
1816 memset(wgmr->wgmr_mac2, 0, sizeof(wgmr->wgmr_mac2));
1817 else {
1818 /* msg.mac2 := MAC(Lm, msg_b) */
1819 wg_algo_mac(wgmr->wgmr_mac2, sizeof(wgmi->wgmi_mac2),
1820 wgp->wgp_latest_cookie, WG_COOKIE_LEN,
1821 (const uint8_t *)wgmr,
1822 offsetof(struct wg_msg_resp, wgmr_mac2),
1823 NULL, 0);
1824 }
1825
1826 memcpy(wgs->wgs_handshake_hash, hash, sizeof(hash));
1827 memcpy(wgs->wgs_chaining_key, ckey, sizeof(ckey));
1828 memcpy(wgs->wgs_ephemeral_key_pub, pubkey, sizeof(pubkey));
1829 memcpy(wgs->wgs_ephemeral_key_priv, privkey, sizeof(privkey));
1830 wgs->wgs_remote_index = wgmi->wgmi_sender;
1831 WG_DLOG("sender=%x\n", wgs->wgs_local_index);
1832 WG_DLOG("receiver=%x\n", wgs->wgs_remote_index);
1833 }
1834
1835 static void
1836 wg_swap_sessions(struct wg_peer *wgp)
1837 {
1838 struct wg_session *wgs, *wgs_prev;
1839
1840 KASSERT(mutex_owned(wgp->wgp_lock));
1841
1842 wgs = wgp->wgp_session_unstable;
1843 KASSERT(wgs->wgs_state == WGS_STATE_ESTABLISHED);
1844
1845 wgs_prev = wgp->wgp_session_stable;
1846 KASSERT(wgs_prev->wgs_state == WGS_STATE_ESTABLISHED ||
1847 wgs_prev->wgs_state == WGS_STATE_UNKNOWN);
1848 atomic_store_release(&wgp->wgp_session_stable, wgs);
1849 wgp->wgp_session_unstable = wgs_prev;
1850 }
1851
1852 static void __noinline
1853 wg_handle_msg_resp(struct wg_softc *wg, const struct wg_msg_resp *wgmr,
1854 const struct sockaddr *src)
1855 {
1856 uint8_t ckey[WG_CHAINING_KEY_LEN]; /* [W] 5.4.3: Cr */
1857 uint8_t hash[WG_HASH_LEN]; /* [W] 5.4.3: Kr */
1858 uint8_t cipher_key[WG_KDF_OUTPUT_LEN];
1859 struct wg_peer *wgp;
1860 struct wg_session *wgs;
1861 struct psref psref;
1862 int error;
1863 uint8_t mac1[WG_MAC_LEN];
1864 struct wg_session *wgs_prev;
1865 struct mbuf *m;
1866
1867 wg_algo_mac_mac1(mac1, sizeof(mac1),
1868 wg->wg_pubkey, sizeof(wg->wg_pubkey),
1869 (const uint8_t *)wgmr, offsetof(struct wg_msg_resp, wgmr_mac1));
1870
1871 /*
1872 * [W] 5.3: Denial of Service Mitigation & Cookies
1873 * "the responder, ..., must always reject messages with an invalid
1874 * msg.mac1"
1875 */
1876 if (!consttime_memequal(mac1, wgmr->wgmr_mac1, sizeof(mac1))) {
1877 WG_DLOG("mac1 is invalid\n");
1878 return;
1879 }
1880
1881 WG_TRACE("resp msg received");
1882 wgs = wg_lookup_session_by_index(wg, wgmr->wgmr_receiver, &psref);
1883 if (wgs == NULL) {
1884 WG_TRACE("No session found");
1885 return;
1886 }
1887
1888 wgp = wgs->wgs_peer;
1889
1890 mutex_enter(wgp->wgp_lock);
1891
1892 /* If we weren't waiting for a handshake response, drop it. */
1893 if (wgs->wgs_state != WGS_STATE_INIT_ACTIVE) {
1894 WG_TRACE("peer sent spurious handshake response, ignoring");
1895 goto out;
1896 }
1897
1898 if (__predict_false(wg_is_underload(wg, wgp, WG_MSG_TYPE_RESP))) {
1899 WG_TRACE("under load");
1900 /*
1901 * [W] 5.3: Denial of Service Mitigation & Cookies
1902 * "the responder, ..., and when under load may reject messages
1903 * with an invalid msg.mac2. If the responder receives a
1904 * message with a valid msg.mac1 yet with an invalid msg.mac2,
1905 * and is under load, it may respond with a cookie reply
1906 * message"
1907 */
1908 uint8_t zero[WG_MAC_LEN] = {0};
1909 if (consttime_memequal(wgmr->wgmr_mac2, zero, sizeof(zero))) {
1910 WG_TRACE("sending a cookie message: no cookie included");
1911 (void)wg_send_cookie_msg(wg, wgp, wgmr->wgmr_sender,
1912 wgmr->wgmr_mac1, src);
1913 goto out;
1914 }
1915 if (!wgp->wgp_last_sent_cookie_valid) {
1916 WG_TRACE("sending a cookie message: no cookie sent ever");
1917 (void)wg_send_cookie_msg(wg, wgp, wgmr->wgmr_sender,
1918 wgmr->wgmr_mac1, src);
1919 goto out;
1920 }
1921 uint8_t mac2[WG_MAC_LEN];
1922 wg_algo_mac(mac2, sizeof(mac2), wgp->wgp_last_sent_cookie,
1923 WG_COOKIE_LEN, (const uint8_t *)wgmr,
1924 offsetof(struct wg_msg_resp, wgmr_mac2), NULL, 0);
1925 if (!consttime_memequal(mac2, wgmr->wgmr_mac2, sizeof(mac2))) {
1926 WG_DLOG("mac2 is invalid\n");
1927 goto out;
1928 }
1929 WG_TRACE("under load, but continue to sending");
1930 }
1931
1932 memcpy(hash, wgs->wgs_handshake_hash, sizeof(hash));
1933 memcpy(ckey, wgs->wgs_chaining_key, sizeof(ckey));
1934
1935 /*
1936 * [W] 5.4.3 Second Message: Responder to Initiator
1937 * "When the initiator receives this message, it does the same
1938 * operations so that its final state variables are identical,
1939 * replacing the operands of the DH function to produce equivalent
1940 * values."
1941 * Note that the following comments of operations are just copies of
1942 * the initiator's ones.
1943 */
1944
1945 /* [N] 2.2: "e" */
1946 /* Cr := KDF1(Cr, Er^pub) */
1947 wg_algo_kdf(ckey, NULL, NULL, ckey, wgmr->wgmr_ephemeral,
1948 sizeof(wgmr->wgmr_ephemeral));
1949 /* Hr := HASH(Hr || msg.ephemeral) */
1950 wg_algo_hash(hash, wgmr->wgmr_ephemeral, sizeof(wgmr->wgmr_ephemeral));
1951
1952 WG_DUMP_HASH("ckey", ckey);
1953 WG_DUMP_HASH("hash", hash);
1954
1955 /* [N] 2.2: "ee" */
1956 /* Cr := KDF1(Cr, DH(Er^priv, Ei^pub)) */
1957 wg_algo_dh_kdf(ckey, NULL, wgs->wgs_ephemeral_key_priv,
1958 wgmr->wgmr_ephemeral);
1959
1960 /* [N] 2.2: "se" */
1961 /* Cr := KDF1(Cr, DH(Er^priv, Si^pub)) */
1962 wg_algo_dh_kdf(ckey, NULL, wg->wg_privkey, wgmr->wgmr_ephemeral);
1963
1964 /* [N] 9.2: "psk" */
1965 {
1966 uint8_t kdfout[WG_KDF_OUTPUT_LEN];
1967 /* Cr, r, k := KDF3(Cr, Q) */
1968 wg_algo_kdf(ckey, kdfout, cipher_key, ckey, wgp->wgp_psk,
1969 sizeof(wgp->wgp_psk));
1970 /* Hr := HASH(Hr || r) */
1971 wg_algo_hash(hash, kdfout, sizeof(kdfout));
1972 }
1973
1974 {
1975 uint8_t out[sizeof(wgmr->wgmr_empty)]; /* for safety */
1976 /* msg.empty := AEAD(k, 0, e, Hr) */
1977 error = wg_algo_aead_dec(out, 0, cipher_key, 0, wgmr->wgmr_empty,
1978 sizeof(wgmr->wgmr_empty), hash, sizeof(hash));
1979 WG_DUMP_HASH("wgmr_empty", wgmr->wgmr_empty);
1980 if (error != 0) {
1981 WG_LOG_RATECHECK(&wgp->wgp_ppsratecheck, LOG_DEBUG,
1982 "%s: peer %s: wg_algo_aead_dec for empty message failed\n",
1983 if_name(&wg->wg_if), wgp->wgp_name);
1984 goto out;
1985 }
1986 /* Hr := HASH(Hr || msg.empty) */
1987 wg_algo_hash(hash, wgmr->wgmr_empty, sizeof(wgmr->wgmr_empty));
1988 }
1989
1990 memcpy(wgs->wgs_handshake_hash, hash, sizeof(wgs->wgs_handshake_hash));
1991 memcpy(wgs->wgs_chaining_key, ckey, sizeof(wgs->wgs_chaining_key));
1992 wgs->wgs_remote_index = wgmr->wgmr_sender;
1993 WG_DLOG("receiver=%x\n", wgs->wgs_remote_index);
1994
1995 KASSERT(wgs->wgs_state == WGS_STATE_INIT_ACTIVE);
1996 wgs->wgs_state = WGS_STATE_ESTABLISHED;
1997 wgs->wgs_time_established = time_uptime;
1998 wgs->wgs_time_last_data_sent = 0;
1999 wgs->wgs_is_initiator = true;
2000 wg_calculate_keys(wgs, true);
2001 wg_clear_states(wgs);
2002 WG_TRACE("WGS_STATE_ESTABLISHED");
2003
2004 callout_stop(&wgp->wgp_handshake_timeout_timer);
2005
2006 wg_swap_sessions(wgp);
2007 KASSERT(wgs == wgp->wgp_session_stable);
2008 wgs_prev = wgp->wgp_session_unstable;
2009 getnanotime(&wgp->wgp_last_handshake_time);
2010 wgp->wgp_handshake_start_time = 0;
2011 wgp->wgp_last_sent_mac1_valid = false;
2012 wgp->wgp_last_sent_cookie_valid = false;
2013
2014 wg_schedule_rekey_timer(wgp);
2015
2016 wg_update_endpoint_if_necessary(wgp, src);
2017
2018 /*
2019 * If we had a data packet queued up, send it; otherwise send a
2020 * keepalive message -- either way we have to send something
2021 * immediately or else the responder will never answer.
2022 */
2023 if ((m = atomic_swap_ptr(&wgp->wgp_pending, NULL)) != NULL) {
2024 kpreempt_disable();
2025 const uint32_t h = curcpu()->ci_index; // pktq_rps_hash(m)
2026 M_SETCTX(m, wgp);
2027 if (__predict_false(!pktq_enqueue(wg_pktq, m, h))) {
2028 WGLOG(LOG_ERR, "%s: pktq full, dropping\n",
2029 if_name(&wg->wg_if));
2030 m_freem(m);
2031 }
2032 kpreempt_enable();
2033 } else {
2034 wg_send_keepalive_msg(wgp, wgs);
2035 }
2036
2037 if (wgs_prev->wgs_state == WGS_STATE_ESTABLISHED) {
2038 /* Wait for wg_get_stable_session to drain. */
2039 pserialize_perform(wgp->wgp_psz);
2040
2041 /* Transition ESTABLISHED->DESTROYING. */
2042 wgs_prev->wgs_state = WGS_STATE_DESTROYING;
2043
2044 /* We can't destroy the old session immediately */
2045 wg_schedule_session_dtor_timer(wgp);
2046 } else {
2047 KASSERTMSG(wgs_prev->wgs_state == WGS_STATE_UNKNOWN,
2048 "state=%d", wgs_prev->wgs_state);
2049 }
2050
2051 out:
2052 mutex_exit(wgp->wgp_lock);
2053 wg_put_session(wgs, &psref);
2054 }
2055
2056 static int
2057 wg_send_handshake_msg_resp(struct wg_softc *wg, struct wg_peer *wgp,
2058 struct wg_session *wgs, const struct wg_msg_init *wgmi)
2059 {
2060 int error;
2061 struct mbuf *m;
2062 struct wg_msg_resp *wgmr;
2063
2064 KASSERT(mutex_owned(wgp->wgp_lock));
2065 KASSERT(wgs == wgp->wgp_session_unstable);
2066 KASSERT(wgs->wgs_state == WGS_STATE_INIT_PASSIVE);
2067
2068 m = m_gethdr(M_WAIT, MT_DATA);
2069 if (sizeof(*wgmr) > MHLEN) {
2070 m_clget(m, M_WAIT);
2071 CTASSERT(sizeof(*wgmr) <= MCLBYTES);
2072 }
2073 m->m_pkthdr.len = m->m_len = sizeof(*wgmr);
2074 wgmr = mtod(m, struct wg_msg_resp *);
2075 wg_fill_msg_resp(wg, wgp, wgs, wgmr, wgmi);
2076
2077 error = wg->wg_ops->send_hs_msg(wgp, m);
2078 if (error == 0)
2079 WG_TRACE("resp msg sent");
2080 return error;
2081 }
2082
2083 static struct wg_peer *
2084 wg_lookup_peer_by_pubkey(struct wg_softc *wg,
2085 const uint8_t pubkey[WG_STATIC_KEY_LEN], struct psref *psref)
2086 {
2087 struct wg_peer *wgp;
2088
2089 int s = pserialize_read_enter();
2090 wgp = thmap_get(wg->wg_peers_bypubkey, pubkey, WG_STATIC_KEY_LEN);
2091 if (wgp != NULL)
2092 wg_get_peer(wgp, psref);
2093 pserialize_read_exit(s);
2094
2095 return wgp;
2096 }
2097
2098 static void
2099 wg_fill_msg_cookie(struct wg_softc *wg, struct wg_peer *wgp,
2100 struct wg_msg_cookie *wgmc, const uint32_t sender,
2101 const uint8_t mac1[WG_MAC_LEN], const struct sockaddr *src)
2102 {
2103 uint8_t cookie[WG_COOKIE_LEN];
2104 uint8_t key[WG_HASH_LEN];
2105 uint8_t addr[sizeof(struct in6_addr)];
2106 size_t addrlen;
2107 uint16_t uh_sport; /* be */
2108
2109 KASSERT(mutex_owned(wgp->wgp_lock));
2110
2111 wgmc->wgmc_type = htole32(WG_MSG_TYPE_COOKIE);
2112 wgmc->wgmc_receiver = sender;
2113 cprng_fast(wgmc->wgmc_salt, sizeof(wgmc->wgmc_salt));
2114
2115 /*
2116 * [W] 5.4.7: Under Load: Cookie Reply Message
2117 * "The secret variable, Rm, changes every two minutes to a
2118 * random value"
2119 */
2120 if ((time_uptime - wgp->wgp_last_genrandval_time) > WG_RANDVAL_TIME) {
2121 wgp->wgp_randval = cprng_strong32();
2122 wgp->wgp_last_genrandval_time = time_uptime;
2123 }
2124
2125 switch (src->sa_family) {
2126 case AF_INET: {
2127 const struct sockaddr_in *sin = satocsin(src);
2128 addrlen = sizeof(sin->sin_addr);
2129 memcpy(addr, &sin->sin_addr, addrlen);
2130 uh_sport = sin->sin_port;
2131 break;
2132 }
2133 #ifdef INET6
2134 case AF_INET6: {
2135 const struct sockaddr_in6 *sin6 = satocsin6(src);
2136 addrlen = sizeof(sin6->sin6_addr);
2137 memcpy(addr, &sin6->sin6_addr, addrlen);
2138 uh_sport = sin6->sin6_port;
2139 break;
2140 }
2141 #endif
2142 default:
2143 panic("invalid af=%d", src->sa_family);
2144 }
2145
2146 wg_algo_mac(cookie, sizeof(cookie),
2147 (const uint8_t *)&wgp->wgp_randval, sizeof(wgp->wgp_randval),
2148 addr, addrlen, (const uint8_t *)&uh_sport, sizeof(uh_sport));
2149 wg_algo_mac_cookie(key, sizeof(key), wg->wg_pubkey,
2150 sizeof(wg->wg_pubkey));
2151 wg_algo_xaead_enc(wgmc->wgmc_cookie, sizeof(wgmc->wgmc_cookie), key,
2152 cookie, sizeof(cookie), mac1, WG_MAC_LEN, wgmc->wgmc_salt);
2153
2154 /* Need to store to calculate mac2 */
2155 memcpy(wgp->wgp_last_sent_cookie, cookie, sizeof(cookie));
2156 wgp->wgp_last_sent_cookie_valid = true;
2157 }
2158
2159 static int
2160 wg_send_cookie_msg(struct wg_softc *wg, struct wg_peer *wgp,
2161 const uint32_t sender, const uint8_t mac1[WG_MAC_LEN],
2162 const struct sockaddr *src)
2163 {
2164 int error;
2165 struct mbuf *m;
2166 struct wg_msg_cookie *wgmc;
2167
2168 KASSERT(mutex_owned(wgp->wgp_lock));
2169
2170 m = m_gethdr(M_WAIT, MT_DATA);
2171 if (sizeof(*wgmc) > MHLEN) {
2172 m_clget(m, M_WAIT);
2173 CTASSERT(sizeof(*wgmc) <= MCLBYTES);
2174 }
2175 m->m_pkthdr.len = m->m_len = sizeof(*wgmc);
2176 wgmc = mtod(m, struct wg_msg_cookie *);
2177 wg_fill_msg_cookie(wg, wgp, wgmc, sender, mac1, src);
2178
2179 error = wg->wg_ops->send_hs_msg(wgp, m);
2180 if (error == 0)
2181 WG_TRACE("cookie msg sent");
2182 return error;
2183 }
2184
2185 static bool
2186 wg_is_underload(struct wg_softc *wg, struct wg_peer *wgp, int msgtype)
2187 {
2188 #ifdef WG_DEBUG_PARAMS
2189 if (wg_force_underload)
2190 return true;
2191 #endif
2192
2193 /*
2194 * XXX we don't have a means of a load estimation. The purpose of
2195 * the mechanism is a DoS mitigation, so we consider frequent handshake
2196 * messages as (a kind of) load; if a message of the same type comes
2197 * to a peer within 1 second, we consider we are under load.
2198 */
2199 time_t last = wgp->wgp_last_msg_received_time[msgtype];
2200 wgp->wgp_last_msg_received_time[msgtype] = time_uptime;
2201 return (time_uptime - last) == 0;
2202 }
2203
2204 static void
2205 wg_calculate_keys(struct wg_session *wgs, const bool initiator)
2206 {
2207
2208 KASSERT(mutex_owned(wgs->wgs_peer->wgp_lock));
2209
2210 /*
2211 * [W] 5.4.5: Ti^send = Tr^recv, Ti^recv = Tr^send := KDF2(Ci = Cr, e)
2212 */
2213 if (initiator) {
2214 wg_algo_kdf(wgs->wgs_tkey_send, wgs->wgs_tkey_recv, NULL,
2215 wgs->wgs_chaining_key, NULL, 0);
2216 } else {
2217 wg_algo_kdf(wgs->wgs_tkey_recv, wgs->wgs_tkey_send, NULL,
2218 wgs->wgs_chaining_key, NULL, 0);
2219 }
2220 WG_DUMP_HASH("wgs_tkey_send", wgs->wgs_tkey_send);
2221 WG_DUMP_HASH("wgs_tkey_recv", wgs->wgs_tkey_recv);
2222 }
2223
2224 static uint64_t
2225 wg_session_get_send_counter(struct wg_session *wgs)
2226 {
2227 #ifdef __HAVE_ATOMIC64_LOADSTORE
2228 return atomic_load_relaxed(&wgs->wgs_send_counter);
2229 #else
2230 uint64_t send_counter;
2231
2232 mutex_enter(&wgs->wgs_send_counter_lock);
2233 send_counter = wgs->wgs_send_counter;
2234 mutex_exit(&wgs->wgs_send_counter_lock);
2235
2236 return send_counter;
2237 #endif
2238 }
2239
2240 static uint64_t
2241 wg_session_inc_send_counter(struct wg_session *wgs)
2242 {
2243 #ifdef __HAVE_ATOMIC64_LOADSTORE
2244 return atomic_inc_64_nv(&wgs->wgs_send_counter) - 1;
2245 #else
2246 uint64_t send_counter;
2247
2248 mutex_enter(&wgs->wgs_send_counter_lock);
2249 send_counter = wgs->wgs_send_counter++;
2250 mutex_exit(&wgs->wgs_send_counter_lock);
2251
2252 return send_counter;
2253 #endif
2254 }
2255
2256 static void
2257 wg_clear_states(struct wg_session *wgs)
2258 {
2259
2260 KASSERT(mutex_owned(wgs->wgs_peer->wgp_lock));
2261
2262 wgs->wgs_send_counter = 0;
2263 sliwin_reset(&wgs->wgs_recvwin->window);
2264
2265 #define wgs_clear(v) explicit_memset(wgs->wgs_##v, 0, sizeof(wgs->wgs_##v))
2266 wgs_clear(handshake_hash);
2267 wgs_clear(chaining_key);
2268 wgs_clear(ephemeral_key_pub);
2269 wgs_clear(ephemeral_key_priv);
2270 wgs_clear(ephemeral_key_peer);
2271 #undef wgs_clear
2272 }
2273
2274 static struct wg_session *
2275 wg_lookup_session_by_index(struct wg_softc *wg, const uint32_t index,
2276 struct psref *psref)
2277 {
2278 struct wg_session *wgs;
2279
2280 int s = pserialize_read_enter();
2281 wgs = thmap_get(wg->wg_sessions_byindex, &index, sizeof index);
2282 if (wgs != NULL) {
2283 KASSERT(atomic_load_relaxed(&wgs->wgs_state) !=
2284 WGS_STATE_UNKNOWN);
2285 psref_acquire(psref, &wgs->wgs_psref, wg_psref_class);
2286 }
2287 pserialize_read_exit(s);
2288
2289 return wgs;
2290 }
2291
2292 static void
2293 wg_schedule_rekey_timer(struct wg_peer *wgp)
2294 {
2295 int timeout = MIN(wg_rekey_after_time, (unsigned)(INT_MAX / hz));
2296
2297 callout_schedule(&wgp->wgp_rekey_timer, timeout * hz);
2298 }
2299
2300 static void
2301 wg_send_keepalive_msg(struct wg_peer *wgp, struct wg_session *wgs)
2302 {
2303 struct mbuf *m;
2304
2305 /*
2306 * [W] 6.5 Passive Keepalive
2307 * "A keepalive message is simply a transport data message with
2308 * a zero-length encapsulated encrypted inner-packet."
2309 */
2310 m = m_gethdr(M_WAIT, MT_DATA);
2311 wg_send_data_msg(wgp, wgs, m);
2312 }
2313
2314 static bool
2315 wg_need_to_send_init_message(struct wg_session *wgs)
2316 {
2317 /*
2318 * [W] 6.2 Transport Message Limits
2319 * "if a peer is the initiator of a current secure session,
2320 * WireGuard will send a handshake initiation message to begin
2321 * a new secure session ... if after receiving a transport data
2322 * message, the current secure session is (REJECT-AFTER-TIME
2323 * KEEPALIVE-TIMEOUT REKEY-TIMEOUT) seconds old and it has
2324 * not yet acted upon this event."
2325 */
2326 return wgs->wgs_is_initiator && wgs->wgs_time_last_data_sent == 0 &&
2327 (time_uptime - wgs->wgs_time_established) >=
2328 (wg_reject_after_time - wg_keepalive_timeout - wg_rekey_timeout);
2329 }
2330
2331 static void
2332 wg_schedule_peer_task(struct wg_peer *wgp, unsigned int task)
2333 {
2334
2335 mutex_enter(wgp->wgp_intr_lock);
2336 WG_DLOG("tasks=%d, task=%d\n", wgp->wgp_tasks, task);
2337 if (wgp->wgp_tasks == 0)
2338 /*
2339 * XXX If the current CPU is already loaded -- e.g., if
2340 * there's already a bunch of handshakes queued up --
2341 * consider tossing this over to another CPU to
2342 * distribute the load.
2343 */
2344 workqueue_enqueue(wg_wq, &wgp->wgp_work, NULL);
2345 wgp->wgp_tasks |= task;
2346 mutex_exit(wgp->wgp_intr_lock);
2347 }
2348
2349 static void
2350 wg_change_endpoint(struct wg_peer *wgp, const struct sockaddr *new)
2351 {
2352 struct wg_sockaddr *wgsa_prev;
2353
2354 WG_TRACE("Changing endpoint");
2355
2356 memcpy(wgp->wgp_endpoint0, new, new->sa_len);
2357 wgsa_prev = wgp->wgp_endpoint;
2358 atomic_store_release(&wgp->wgp_endpoint, wgp->wgp_endpoint0);
2359 wgp->wgp_endpoint0 = wgsa_prev;
2360 atomic_store_release(&wgp->wgp_endpoint_available, true);
2361
2362 wg_schedule_peer_task(wgp, WGP_TASK_ENDPOINT_CHANGED);
2363 }
2364
2365 static bool
2366 wg_validate_inner_packet(const char *packet, size_t decrypted_len, int *af)
2367 {
2368 uint16_t packet_len;
2369 const struct ip *ip;
2370
2371 if (__predict_false(decrypted_len < sizeof(struct ip)))
2372 return false;
2373
2374 ip = (const struct ip *)packet;
2375 if (ip->ip_v == 4)
2376 *af = AF_INET;
2377 else if (ip->ip_v == 6)
2378 *af = AF_INET6;
2379 else
2380 return false;
2381
2382 WG_DLOG("af=%d\n", *af);
2383
2384 switch (*af) {
2385 #ifdef INET
2386 case AF_INET:
2387 packet_len = ntohs(ip->ip_len);
2388 break;
2389 #endif
2390 #ifdef INET6
2391 case AF_INET6: {
2392 const struct ip6_hdr *ip6;
2393
2394 if (__predict_false(decrypted_len < sizeof(struct ip6_hdr)))
2395 return false;
2396
2397 ip6 = (const struct ip6_hdr *)packet;
2398 packet_len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
2399 break;
2400 }
2401 #endif
2402 default:
2403 return false;
2404 }
2405
2406 WG_DLOG("packet_len=%u\n", packet_len);
2407 if (packet_len > decrypted_len)
2408 return false;
2409
2410 return true;
2411 }
2412
2413 static bool
2414 wg_validate_route(struct wg_softc *wg, struct wg_peer *wgp_expected,
2415 int af, char *packet)
2416 {
2417 struct sockaddr_storage ss;
2418 struct sockaddr *sa;
2419 struct psref psref;
2420 struct wg_peer *wgp;
2421 bool ok;
2422
2423 /*
2424 * II CRYPTOKEY ROUTING
2425 * "it will only accept it if its source IP resolves in the
2426 * table to the public key used in the secure session for
2427 * decrypting it."
2428 */
2429
2430 if (af == AF_INET) {
2431 const struct ip *ip = (const struct ip *)packet;
2432 struct sockaddr_in *sin = (struct sockaddr_in *)&ss;
2433 sockaddr_in_init(sin, &ip->ip_src, 0);
2434 sa = sintosa(sin);
2435 #ifdef INET6
2436 } else {
2437 const struct ip6_hdr *ip6 = (const struct ip6_hdr *)packet;
2438 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&ss;
2439 sockaddr_in6_init(sin6, &ip6->ip6_src, 0, 0, 0);
2440 sa = sin6tosa(sin6);
2441 #endif
2442 }
2443
2444 wgp = wg_pick_peer_by_sa(wg, sa, &psref);
2445 ok = (wgp == wgp_expected);
2446 if (wgp != NULL)
2447 wg_put_peer(wgp, &psref);
2448
2449 return ok;
2450 }
2451
2452 static void
2453 wg_session_dtor_timer(void *arg)
2454 {
2455 struct wg_peer *wgp = arg;
2456
2457 WG_TRACE("enter");
2458
2459 wg_schedule_peer_task(wgp, WGP_TASK_DESTROY_PREV_SESSION);
2460 }
2461
2462 static void
2463 wg_schedule_session_dtor_timer(struct wg_peer *wgp)
2464 {
2465
2466 /* 1 second grace period */
2467 callout_schedule(&wgp->wgp_session_dtor_timer, hz);
2468 }
2469
2470 static bool
2471 sockaddr_port_match(const struct sockaddr *sa1, const struct sockaddr *sa2)
2472 {
2473 if (sa1->sa_family != sa2->sa_family)
2474 return false;
2475
2476 switch (sa1->sa_family) {
2477 #ifdef INET
2478 case AF_INET:
2479 return satocsin(sa1)->sin_port == satocsin(sa2)->sin_port;
2480 #endif
2481 #ifdef INET6
2482 case AF_INET6:
2483 return satocsin6(sa1)->sin6_port == satocsin6(sa2)->sin6_port;
2484 #endif
2485 default:
2486 return false;
2487 }
2488 }
2489
2490 static void
2491 wg_update_endpoint_if_necessary(struct wg_peer *wgp,
2492 const struct sockaddr *src)
2493 {
2494 struct wg_sockaddr *wgsa;
2495 struct psref psref;
2496
2497 wgsa = wg_get_endpoint_sa(wgp, &psref);
2498
2499 #ifdef WG_DEBUG_LOG
2500 char oldaddr[128], newaddr[128];
2501 sockaddr_format(wgsatosa(wgsa), oldaddr, sizeof(oldaddr));
2502 sockaddr_format(src, newaddr, sizeof(newaddr));
2503 WG_DLOG("old=%s, new=%s\n", oldaddr, newaddr);
2504 #endif
2505
2506 /*
2507 * III: "Since the packet has authenticated correctly, the source IP of
2508 * the outer UDP/IP packet is used to update the endpoint for peer..."
2509 */
2510 if (__predict_false(sockaddr_cmp(src, wgsatosa(wgsa)) != 0 ||
2511 !sockaddr_port_match(src, wgsatosa(wgsa)))) {
2512 /* XXX We can't change the endpoint twice in a short period */
2513 if (atomic_swap_uint(&wgp->wgp_endpoint_changing, 1) == 0) {
2514 wg_change_endpoint(wgp, src);
2515 }
2516 }
2517
2518 wg_put_sa(wgp, wgsa, &psref);
2519 }
2520
2521 static void __noinline
2522 wg_handle_msg_data(struct wg_softc *wg, struct mbuf *m,
2523 const struct sockaddr *src)
2524 {
2525 struct wg_msg_data *wgmd;
2526 char *encrypted_buf = NULL, *decrypted_buf;
2527 size_t encrypted_len, decrypted_len;
2528 struct wg_session *wgs;
2529 struct wg_peer *wgp;
2530 int state;
2531 size_t mlen;
2532 struct psref psref;
2533 int error, af;
2534 bool success, free_encrypted_buf = false, ok;
2535 struct mbuf *n;
2536
2537 KASSERT(m->m_len >= sizeof(struct wg_msg_data));
2538 wgmd = mtod(m, struct wg_msg_data *);
2539
2540 KASSERT(wgmd->wgmd_type == htole32(WG_MSG_TYPE_DATA));
2541 WG_TRACE("data");
2542
2543 /* Find the putative session, or drop. */
2544 wgs = wg_lookup_session_by_index(wg, wgmd->wgmd_receiver, &psref);
2545 if (wgs == NULL) {
2546 WG_TRACE("No session found");
2547 m_freem(m);
2548 return;
2549 }
2550
2551 /*
2552 * We are only ready to handle data when in INIT_PASSIVE,
2553 * ESTABLISHED, or DESTROYING. All transitions out of that
2554 * state dissociate the session index and drain psrefs.
2555 */
2556 state = atomic_load_relaxed(&wgs->wgs_state);
2557 switch (state) {
2558 case WGS_STATE_UNKNOWN:
2559 panic("wg session %p in unknown state has session index %u",
2560 wgs, wgmd->wgmd_receiver);
2561 case WGS_STATE_INIT_ACTIVE:
2562 WG_TRACE("not yet ready for data");
2563 goto out;
2564 case WGS_STATE_INIT_PASSIVE:
2565 case WGS_STATE_ESTABLISHED:
2566 case WGS_STATE_DESTROYING:
2567 break;
2568 }
2569
2570 /*
2571 * Get the peer, for rate-limited logs (XXX MPSAFE, dtrace) and
2572 * to update the endpoint if authentication succeeds.
2573 */
2574 wgp = wgs->wgs_peer;
2575
2576 /*
2577 * Reject outrageously wrong sequence numbers before doing any
2578 * crypto work or taking any locks.
2579 */
2580 error = sliwin_check_fast(&wgs->wgs_recvwin->window,
2581 le64toh(wgmd->wgmd_counter));
2582 if (error) {
2583 WG_LOG_RATECHECK(&wgp->wgp_ppsratecheck, LOG_DEBUG,
2584 "%s: peer %s: out-of-window packet: %"PRIu64"\n",
2585 if_name(&wg->wg_if), wgp->wgp_name,
2586 le64toh(wgmd->wgmd_counter));
2587 goto out;
2588 }
2589
2590 /* Ensure the payload and authenticator are contiguous. */
2591 mlen = m_length(m);
2592 encrypted_len = mlen - sizeof(*wgmd);
2593 if (encrypted_len < WG_AUTHTAG_LEN) {
2594 WG_DLOG("Short encrypted_len: %lu\n", encrypted_len);
2595 goto out;
2596 }
2597 success = m_ensure_contig(&m, sizeof(*wgmd) + encrypted_len);
2598 if (success) {
2599 encrypted_buf = mtod(m, char *) + sizeof(*wgmd);
2600 } else {
2601 encrypted_buf = kmem_intr_alloc(encrypted_len, KM_NOSLEEP);
2602 if (encrypted_buf == NULL) {
2603 WG_DLOG("failed to allocate encrypted_buf\n");
2604 goto out;
2605 }
2606 m_copydata(m, sizeof(*wgmd), encrypted_len, encrypted_buf);
2607 free_encrypted_buf = true;
2608 }
2609 /* m_ensure_contig may change m regardless of its result */
2610 KASSERT(m->m_len >= sizeof(*wgmd));
2611 wgmd = mtod(m, struct wg_msg_data *);
2612
2613 /*
2614 * Get a buffer for the plaintext. Add WG_AUTHTAG_LEN to avoid
2615 * a zero-length buffer (XXX). Drop if plaintext is longer
2616 * than MCLBYTES (XXX).
2617 */
2618 decrypted_len = encrypted_len - WG_AUTHTAG_LEN;
2619 if (decrypted_len > MCLBYTES) {
2620 /* FIXME handle larger data than MCLBYTES */
2621 WG_DLOG("couldn't handle larger data than MCLBYTES\n");
2622 goto out;
2623 }
2624 n = wg_get_mbuf(0, decrypted_len + WG_AUTHTAG_LEN);
2625 if (n == NULL) {
2626 WG_DLOG("wg_get_mbuf failed\n");
2627 goto out;
2628 }
2629 decrypted_buf = mtod(n, char *);
2630
2631 /* Decrypt and verify the packet. */
2632 WG_DLOG("mlen=%lu, encrypted_len=%lu\n", mlen, encrypted_len);
2633 error = wg_algo_aead_dec(decrypted_buf,
2634 encrypted_len - WG_AUTHTAG_LEN /* can be 0 */,
2635 wgs->wgs_tkey_recv, le64toh(wgmd->wgmd_counter), encrypted_buf,
2636 encrypted_len, NULL, 0);
2637 if (error != 0) {
2638 WG_LOG_RATECHECK(&wgp->wgp_ppsratecheck, LOG_DEBUG,
2639 "%s: peer %s: failed to wg_algo_aead_dec\n",
2640 if_name(&wg->wg_if), wgp->wgp_name);
2641 m_freem(n);
2642 goto out;
2643 }
2644 WG_DLOG("outsize=%u\n", (u_int)decrypted_len);
2645
2646 /* Packet is genuine. Reject it if a replay or just too old. */
2647 mutex_enter(&wgs->wgs_recvwin->lock);
2648 error = sliwin_update(&wgs->wgs_recvwin->window,
2649 le64toh(wgmd->wgmd_counter));
2650 mutex_exit(&wgs->wgs_recvwin->lock);
2651 if (error) {
2652 WG_LOG_RATECHECK(&wgp->wgp_ppsratecheck, LOG_DEBUG,
2653 "%s: peer %s: replay or out-of-window packet: %"PRIu64"\n",
2654 if_name(&wg->wg_if), wgp->wgp_name,
2655 le64toh(wgmd->wgmd_counter));
2656 m_freem(n);
2657 goto out;
2658 }
2659
2660 /* We're done with m now; free it and chuck the pointers. */
2661 m_freem(m);
2662 m = NULL;
2663 wgmd = NULL;
2664
2665 /*
2666 * Validate the encapsulated packet header and get the address
2667 * family, or drop.
2668 */
2669 ok = wg_validate_inner_packet(decrypted_buf, decrypted_len, &af);
2670 if (!ok) {
2671 m_freem(n);
2672 goto out;
2673 }
2674
2675 /*
2676 * The packet is genuine. Update the peer's endpoint if the
2677 * source address changed.
2678 *
2679 * XXX How to prevent DoS by replaying genuine packets from the
2680 * wrong source address?
2681 */
2682 wg_update_endpoint_if_necessary(wgp, src);
2683
2684 /* Submit it into our network stack if routable. */
2685 ok = wg_validate_route(wg, wgp, af, decrypted_buf);
2686 if (ok) {
2687 wg->wg_ops->input(&wg->wg_if, n, af);
2688 } else {
2689 char addrstr[INET6_ADDRSTRLEN];
2690 memset(addrstr, 0, sizeof(addrstr));
2691 if (af == AF_INET) {
2692 const struct ip *ip = (const struct ip *)decrypted_buf;
2693 IN_PRINT(addrstr, &ip->ip_src);
2694 #ifdef INET6
2695 } else if (af == AF_INET6) {
2696 const struct ip6_hdr *ip6 =
2697 (const struct ip6_hdr *)decrypted_buf;
2698 IN6_PRINT(addrstr, &ip6->ip6_src);
2699 #endif
2700 }
2701 WG_LOG_RATECHECK(&wgp->wgp_ppsratecheck, LOG_DEBUG,
2702 "%s: peer %s: invalid source address (%s)\n",
2703 if_name(&wg->wg_if), wgp->wgp_name, addrstr);
2704 m_freem(n);
2705 /*
2706 * The inner address is invalid however the session is valid
2707 * so continue the session processing below.
2708 */
2709 }
2710 n = NULL;
2711
2712 /* Update the state machine if necessary. */
2713 if (__predict_false(state == WGS_STATE_INIT_PASSIVE)) {
2714 /*
2715 * We were waiting for the initiator to send their
2716 * first data transport message, and that has happened.
2717 * Schedule a task to establish this session.
2718 */
2719 wg_schedule_peer_task(wgp, WGP_TASK_ESTABLISH_SESSION);
2720 } else {
2721 if (__predict_false(wg_need_to_send_init_message(wgs))) {
2722 wg_schedule_peer_task(wgp, WGP_TASK_SEND_INIT_MESSAGE);
2723 }
2724 /*
2725 * [W] 6.5 Passive Keepalive
2726 * "If a peer has received a validly-authenticated transport
2727 * data message (section 5.4.6), but does not have any packets
2728 * itself to send back for KEEPALIVE-TIMEOUT seconds, it sends
2729 * a keepalive message."
2730 */
2731 WG_DLOG("time_uptime=%ju wgs_time_last_data_sent=%ju\n",
2732 (uintmax_t)time_uptime,
2733 (uintmax_t)wgs->wgs_time_last_data_sent);
2734 if ((time_uptime - wgs->wgs_time_last_data_sent) >=
2735 wg_keepalive_timeout) {
2736 WG_TRACE("Schedule sending keepalive message");
2737 /*
2738 * We can't send a keepalive message here to avoid
2739 * a deadlock; we already hold the solock of a socket
2740 * that is used to send the message.
2741 */
2742 wg_schedule_peer_task(wgp,
2743 WGP_TASK_SEND_KEEPALIVE_MESSAGE);
2744 }
2745 }
2746 out:
2747 wg_put_session(wgs, &psref);
2748 if (m != NULL)
2749 m_freem(m);
2750 if (free_encrypted_buf)
2751 kmem_intr_free(encrypted_buf, encrypted_len);
2752 }
2753
2754 static void __noinline
2755 wg_handle_msg_cookie(struct wg_softc *wg, const struct wg_msg_cookie *wgmc)
2756 {
2757 struct wg_session *wgs;
2758 struct wg_peer *wgp;
2759 struct psref psref;
2760 int error;
2761 uint8_t key[WG_HASH_LEN];
2762 uint8_t cookie[WG_COOKIE_LEN];
2763
2764 WG_TRACE("cookie msg received");
2765
2766 /* Find the putative session. */
2767 wgs = wg_lookup_session_by_index(wg, wgmc->wgmc_receiver, &psref);
2768 if (wgs == NULL) {
2769 WG_TRACE("No session found");
2770 return;
2771 }
2772
2773 /* Lock the peer so we can update the cookie state. */
2774 wgp = wgs->wgs_peer;
2775 mutex_enter(wgp->wgp_lock);
2776
2777 if (!wgp->wgp_last_sent_mac1_valid) {
2778 WG_TRACE("No valid mac1 sent (or expired)");
2779 goto out;
2780 }
2781
2782 /* Decrypt the cookie and store it for later handshake retry. */
2783 wg_algo_mac_cookie(key, sizeof(key), wgp->wgp_pubkey,
2784 sizeof(wgp->wgp_pubkey));
2785 error = wg_algo_xaead_dec(cookie, sizeof(cookie), key,
2786 wgmc->wgmc_cookie, sizeof(wgmc->wgmc_cookie),
2787 wgp->wgp_last_sent_mac1, sizeof(wgp->wgp_last_sent_mac1),
2788 wgmc->wgmc_salt);
2789 if (error != 0) {
2790 WG_LOG_RATECHECK(&wgp->wgp_ppsratecheck, LOG_DEBUG,
2791 "%s: peer %s: wg_algo_aead_dec for cookie failed: "
2792 "error=%d\n", if_name(&wg->wg_if), wgp->wgp_name, error);
2793 goto out;
2794 }
2795 /*
2796 * [W] 6.6: Interaction with Cookie Reply System
2797 * "it should simply store the decrypted cookie value from the cookie
2798 * reply message, and wait for the expiration of the REKEY-TIMEOUT
2799 * timer for retrying a handshake initiation message."
2800 */
2801 wgp->wgp_latest_cookie_time = time_uptime;
2802 memcpy(wgp->wgp_latest_cookie, cookie, sizeof(wgp->wgp_latest_cookie));
2803 out:
2804 mutex_exit(wgp->wgp_lock);
2805 wg_put_session(wgs, &psref);
2806 }
2807
2808 static struct mbuf *
2809 wg_validate_msg_header(struct wg_softc *wg, struct mbuf *m)
2810 {
2811 struct wg_msg wgm;
2812 size_t mbuflen;
2813 size_t msglen;
2814
2815 /*
2816 * Get the mbuf chain length. It is already guaranteed, by
2817 * wg_overudp_cb, to be large enough for a struct wg_msg.
2818 */
2819 mbuflen = m_length(m);
2820 KASSERT(mbuflen >= sizeof(struct wg_msg));
2821
2822 /*
2823 * Copy the message header (32-bit message type) out -- we'll
2824 * worry about contiguity and alignment later.
2825 */
2826 m_copydata(m, 0, sizeof(wgm), &wgm);
2827 switch (le32toh(wgm.wgm_type)) {
2828 case WG_MSG_TYPE_INIT:
2829 msglen = sizeof(struct wg_msg_init);
2830 break;
2831 case WG_MSG_TYPE_RESP:
2832 msglen = sizeof(struct wg_msg_resp);
2833 break;
2834 case WG_MSG_TYPE_COOKIE:
2835 msglen = sizeof(struct wg_msg_cookie);
2836 break;
2837 case WG_MSG_TYPE_DATA:
2838 msglen = sizeof(struct wg_msg_data);
2839 break;
2840 default:
2841 WG_LOG_RATECHECK(&wg->wg_ppsratecheck, LOG_DEBUG,
2842 "%s: Unexpected msg type: %u\n", if_name(&wg->wg_if),
2843 le32toh(wgm.wgm_type));
2844 goto error;
2845 }
2846
2847 /* Verify the mbuf chain is long enough for this type of message. */
2848 if (__predict_false(mbuflen < msglen)) {
2849 WG_DLOG("Invalid msg size: mbuflen=%lu type=%u\n", mbuflen,
2850 le32toh(wgm.wgm_type));
2851 goto error;
2852 }
2853
2854 /* Make the message header contiguous if necessary. */
2855 if (__predict_false(m->m_len < msglen)) {
2856 m = m_pullup(m, msglen);
2857 if (m == NULL)
2858 return NULL;
2859 }
2860
2861 return m;
2862
2863 error:
2864 m_freem(m);
2865 return NULL;
2866 }
2867
2868 static void
2869 wg_handle_packet(struct wg_softc *wg, struct mbuf *m,
2870 const struct sockaddr *src)
2871 {
2872 struct wg_msg *wgm;
2873
2874 KASSERT(curlwp->l_pflag & LP_BOUND);
2875
2876 m = wg_validate_msg_header(wg, m);
2877 if (__predict_false(m == NULL))
2878 return;
2879
2880 KASSERT(m->m_len >= sizeof(struct wg_msg));
2881 wgm = mtod(m, struct wg_msg *);
2882 switch (le32toh(wgm->wgm_type)) {
2883 case WG_MSG_TYPE_INIT:
2884 wg_handle_msg_init(wg, (struct wg_msg_init *)wgm, src);
2885 break;
2886 case WG_MSG_TYPE_RESP:
2887 wg_handle_msg_resp(wg, (struct wg_msg_resp *)wgm, src);
2888 break;
2889 case WG_MSG_TYPE_COOKIE:
2890 wg_handle_msg_cookie(wg, (struct wg_msg_cookie *)wgm);
2891 break;
2892 case WG_MSG_TYPE_DATA:
2893 wg_handle_msg_data(wg, m, src);
2894 /* wg_handle_msg_data frees m for us */
2895 return;
2896 default:
2897 panic("invalid message type: %d", le32toh(wgm->wgm_type));
2898 }
2899
2900 m_freem(m);
2901 }
2902
2903 static void
2904 wg_receive_packets(struct wg_softc *wg, const int af)
2905 {
2906
2907 for (;;) {
2908 int error, flags;
2909 struct socket *so;
2910 struct mbuf *m = NULL;
2911 struct uio dummy_uio;
2912 struct mbuf *paddr = NULL;
2913 struct sockaddr *src;
2914
2915 so = wg_get_so_by_af(wg, af);
2916 flags = MSG_DONTWAIT;
2917 dummy_uio.uio_resid = 1000000000;
2918
2919 error = so->so_receive(so, &paddr, &dummy_uio, &m, NULL,
2920 &flags);
2921 if (error || m == NULL) {
2922 //if (error == EWOULDBLOCK)
2923 return;
2924 }
2925
2926 KASSERT(paddr != NULL);
2927 KASSERT(paddr->m_len >= sizeof(struct sockaddr));
2928 src = mtod(paddr, struct sockaddr *);
2929
2930 wg_handle_packet(wg, m, src);
2931 }
2932 }
2933
2934 static void
2935 wg_get_peer(struct wg_peer *wgp, struct psref *psref)
2936 {
2937
2938 psref_acquire(psref, &wgp->wgp_psref, wg_psref_class);
2939 }
2940
2941 static void
2942 wg_put_peer(struct wg_peer *wgp, struct psref *psref)
2943 {
2944
2945 psref_release(psref, &wgp->wgp_psref, wg_psref_class);
2946 }
2947
2948 static void
2949 wg_task_send_init_message(struct wg_softc *wg, struct wg_peer *wgp)
2950 {
2951 struct wg_session *wgs;
2952
2953 WG_TRACE("WGP_TASK_SEND_INIT_MESSAGE");
2954
2955 KASSERT(mutex_owned(wgp->wgp_lock));
2956
2957 if (!atomic_load_acquire(&wgp->wgp_endpoint_available)) {
2958 WGLOG(LOG_DEBUG, "%s: No endpoint available\n",
2959 if_name(&wg->wg_if));
2960 /* XXX should do something? */
2961 return;
2962 }
2963
2964 wgs = wgp->wgp_session_stable;
2965 if (wgs->wgs_state == WGS_STATE_UNKNOWN) {
2966 /* XXX What if the unstable session is already INIT_ACTIVE? */
2967 wg_send_handshake_msg_init(wg, wgp);
2968 } else {
2969 /* rekey */
2970 wgs = wgp->wgp_session_unstable;
2971 if (wgs->wgs_state != WGS_STATE_INIT_ACTIVE)
2972 wg_send_handshake_msg_init(wg, wgp);
2973 }
2974 }
2975
2976 static void
2977 wg_task_retry_handshake(struct wg_softc *wg, struct wg_peer *wgp)
2978 {
2979 struct wg_session *wgs;
2980
2981 WG_TRACE("WGP_TASK_RETRY_HANDSHAKE");
2982
2983 KASSERT(mutex_owned(wgp->wgp_lock));
2984 KASSERT(wgp->wgp_handshake_start_time != 0);
2985
2986 wgs = wgp->wgp_session_unstable;
2987 if (wgs->wgs_state != WGS_STATE_INIT_ACTIVE)
2988 return;
2989
2990 /*
2991 * XXX no real need to assign a new index here, but we do need
2992 * to transition to UNKNOWN temporarily
2993 */
2994 wg_put_session_index(wg, wgs);
2995
2996 /* [W] 6.4 Handshake Initiation Retransmission */
2997 if ((time_uptime - wgp->wgp_handshake_start_time) >
2998 wg_rekey_attempt_time) {
2999 /* Give up handshaking */
3000 wgp->wgp_handshake_start_time = 0;
3001 WG_TRACE("give up");
3002
3003 /*
3004 * If a new data packet comes, handshaking will be retried
3005 * and a new session would be established at that time,
3006 * however we don't want to send pending packets then.
3007 */
3008 wg_purge_pending_packets(wgp);
3009 return;
3010 }
3011
3012 wg_task_send_init_message(wg, wgp);
3013 }
3014
3015 static void
3016 wg_task_establish_session(struct wg_softc *wg, struct wg_peer *wgp)
3017 {
3018 struct wg_session *wgs, *wgs_prev;
3019 struct mbuf *m;
3020
3021 KASSERT(mutex_owned(wgp->wgp_lock));
3022
3023 wgs = wgp->wgp_session_unstable;
3024 if (wgs->wgs_state != WGS_STATE_INIT_PASSIVE)
3025 /* XXX Can this happen? */
3026 return;
3027
3028 wgs->wgs_state = WGS_STATE_ESTABLISHED;
3029 wgs->wgs_time_established = time_uptime;
3030 wgs->wgs_time_last_data_sent = 0;
3031 wgs->wgs_is_initiator = false;
3032 WG_TRACE("WGS_STATE_ESTABLISHED");
3033
3034 wg_swap_sessions(wgp);
3035 KASSERT(wgs == wgp->wgp_session_stable);
3036 wgs_prev = wgp->wgp_session_unstable;
3037 getnanotime(&wgp->wgp_last_handshake_time);
3038 wgp->wgp_handshake_start_time = 0;
3039 wgp->wgp_last_sent_mac1_valid = false;
3040 wgp->wgp_last_sent_cookie_valid = false;
3041
3042 /* If we had a data packet queued up, send it. */
3043 if ((m = atomic_swap_ptr(&wgp->wgp_pending, NULL)) != NULL) {
3044 kpreempt_disable();
3045 const uint32_t h = curcpu()->ci_index; // pktq_rps_hash(m)
3046 M_SETCTX(m, wgp);
3047 if (__predict_false(!pktq_enqueue(wg_pktq, m, h))) {
3048 WGLOG(LOG_ERR, "%s: pktq full, dropping\n",
3049 if_name(&wg->wg_if));
3050 m_freem(m);
3051 }
3052 kpreempt_enable();
3053 }
3054
3055 if (wgs_prev->wgs_state == WGS_STATE_ESTABLISHED) {
3056 /* Wait for wg_get_stable_session to drain. */
3057 pserialize_perform(wgp->wgp_psz);
3058
3059 /* Transition ESTABLISHED->DESTROYING. */
3060 wgs_prev->wgs_state = WGS_STATE_DESTROYING;
3061
3062 /* We can't destroy the old session immediately */
3063 wg_schedule_session_dtor_timer(wgp);
3064 } else {
3065 KASSERTMSG(wgs_prev->wgs_state == WGS_STATE_UNKNOWN,
3066 "state=%d", wgs_prev->wgs_state);
3067 wg_clear_states(wgs_prev);
3068 wgs_prev->wgs_state = WGS_STATE_UNKNOWN;
3069 }
3070 }
3071
3072 static void
3073 wg_task_endpoint_changed(struct wg_softc *wg, struct wg_peer *wgp)
3074 {
3075
3076 WG_TRACE("WGP_TASK_ENDPOINT_CHANGED");
3077
3078 KASSERT(mutex_owned(wgp->wgp_lock));
3079
3080 if (atomic_load_relaxed(&wgp->wgp_endpoint_changing)) {
3081 pserialize_perform(wgp->wgp_psz);
3082 mutex_exit(wgp->wgp_lock);
3083 psref_target_destroy(&wgp->wgp_endpoint0->wgsa_psref,
3084 wg_psref_class);
3085 psref_target_init(&wgp->wgp_endpoint0->wgsa_psref,
3086 wg_psref_class);
3087 mutex_enter(wgp->wgp_lock);
3088 atomic_store_release(&wgp->wgp_endpoint_changing, 0);
3089 }
3090 }
3091
3092 static void
3093 wg_task_send_keepalive_message(struct wg_softc *wg, struct wg_peer *wgp)
3094 {
3095 struct wg_session *wgs;
3096
3097 WG_TRACE("WGP_TASK_SEND_KEEPALIVE_MESSAGE");
3098
3099 KASSERT(mutex_owned(wgp->wgp_lock));
3100
3101 wgs = wgp->wgp_session_stable;
3102 if (wgs->wgs_state != WGS_STATE_ESTABLISHED)
3103 return;
3104
3105 wg_send_keepalive_msg(wgp, wgs);
3106 }
3107
3108 static void
3109 wg_task_destroy_prev_session(struct wg_softc *wg, struct wg_peer *wgp)
3110 {
3111 struct wg_session *wgs;
3112
3113 WG_TRACE("WGP_TASK_DESTROY_PREV_SESSION");
3114
3115 KASSERT(mutex_owned(wgp->wgp_lock));
3116
3117 wgs = wgp->wgp_session_unstable;
3118 if (wgs->wgs_state == WGS_STATE_DESTROYING) {
3119 wg_put_session_index(wg, wgs);
3120 }
3121 }
3122
3123 static void
3124 wg_peer_work(struct work *wk, void *cookie)
3125 {
3126 struct wg_peer *wgp = container_of(wk, struct wg_peer, wgp_work);
3127 struct wg_softc *wg = wgp->wgp_sc;
3128 unsigned int tasks;
3129
3130 mutex_enter(wgp->wgp_intr_lock);
3131 while ((tasks = wgp->wgp_tasks) != 0) {
3132 wgp->wgp_tasks = 0;
3133 mutex_exit(wgp->wgp_intr_lock);
3134
3135 mutex_enter(wgp->wgp_lock);
3136 if (ISSET(tasks, WGP_TASK_SEND_INIT_MESSAGE))
3137 wg_task_send_init_message(wg, wgp);
3138 if (ISSET(tasks, WGP_TASK_RETRY_HANDSHAKE))
3139 wg_task_retry_handshake(wg, wgp);
3140 if (ISSET(tasks, WGP_TASK_ESTABLISH_SESSION))
3141 wg_task_establish_session(wg, wgp);
3142 if (ISSET(tasks, WGP_TASK_ENDPOINT_CHANGED))
3143 wg_task_endpoint_changed(wg, wgp);
3144 if (ISSET(tasks, WGP_TASK_SEND_KEEPALIVE_MESSAGE))
3145 wg_task_send_keepalive_message(wg, wgp);
3146 if (ISSET(tasks, WGP_TASK_DESTROY_PREV_SESSION))
3147 wg_task_destroy_prev_session(wg, wgp);
3148 mutex_exit(wgp->wgp_lock);
3149
3150 mutex_enter(wgp->wgp_intr_lock);
3151 }
3152 mutex_exit(wgp->wgp_intr_lock);
3153 }
3154
3155 static void
3156 wg_job(struct threadpool_job *job)
3157 {
3158 struct wg_softc *wg = container_of(job, struct wg_softc, wg_job);
3159 int bound, upcalls;
3160
3161 mutex_enter(wg->wg_intr_lock);
3162 while ((upcalls = wg->wg_upcalls) != 0) {
3163 wg->wg_upcalls = 0;
3164 mutex_exit(wg->wg_intr_lock);
3165 bound = curlwp_bind();
3166 if (ISSET(upcalls, WG_UPCALL_INET))
3167 wg_receive_packets(wg, AF_INET);
3168 if (ISSET(upcalls, WG_UPCALL_INET6))
3169 wg_receive_packets(wg, AF_INET6);
3170 curlwp_bindx(bound);
3171 mutex_enter(wg->wg_intr_lock);
3172 }
3173 threadpool_job_done(job);
3174 mutex_exit(wg->wg_intr_lock);
3175 }
3176
3177 static int
3178 wg_bind_port(struct wg_softc *wg, const uint16_t port)
3179 {
3180 int error;
3181 uint16_t old_port = wg->wg_listen_port;
3182
3183 if (port != 0 && old_port == port)
3184 return 0;
3185
3186 struct sockaddr_in _sin, *sin = &_sin;
3187 sin->sin_len = sizeof(*sin);
3188 sin->sin_family = AF_INET;
3189 sin->sin_addr.s_addr = INADDR_ANY;
3190 sin->sin_port = htons(port);
3191
3192 error = sobind(wg->wg_so4, sintosa(sin), curlwp);
3193 if (error != 0)
3194 return error;
3195
3196 #ifdef INET6
3197 struct sockaddr_in6 _sin6, *sin6 = &_sin6;
3198 sin6->sin6_len = sizeof(*sin6);
3199 sin6->sin6_family = AF_INET6;
3200 sin6->sin6_addr = in6addr_any;
3201 sin6->sin6_port = htons(port);
3202
3203 error = sobind(wg->wg_so6, sin6tosa(sin6), curlwp);
3204 if (error != 0)
3205 return error;
3206 #endif
3207
3208 wg->wg_listen_port = port;
3209
3210 return 0;
3211 }
3212
3213 static void
3214 wg_so_upcall(struct socket *so, void *cookie, int events, int waitflag)
3215 {
3216 struct wg_softc *wg = cookie;
3217 int reason;
3218
3219 reason = (so->so_proto->pr_domain->dom_family == AF_INET) ?
3220 WG_UPCALL_INET :
3221 WG_UPCALL_INET6;
3222
3223 mutex_enter(wg->wg_intr_lock);
3224 wg->wg_upcalls |= reason;
3225 threadpool_schedule_job(wg->wg_threadpool, &wg->wg_job);
3226 mutex_exit(wg->wg_intr_lock);
3227 }
3228
3229 static int
3230 wg_overudp_cb(struct mbuf **mp, int offset, struct socket *so,
3231 struct sockaddr *src, void *arg)
3232 {
3233 struct wg_softc *wg = arg;
3234 struct wg_msg wgm;
3235 struct mbuf *m = *mp;
3236
3237 WG_TRACE("enter");
3238
3239 /* Verify the mbuf chain is long enough to have a wg msg header. */
3240 KASSERT(offset <= m_length(m));
3241 if (__predict_false(m_length(m) - offset < sizeof(struct wg_msg))) {
3242 /* drop on the floor */
3243 m_freem(m);
3244 return -1;
3245 }
3246
3247 /*
3248 * Copy the message header (32-bit message type) out -- we'll
3249 * worry about contiguity and alignment later.
3250 */
3251 m_copydata(m, offset, sizeof(struct wg_msg), &wgm);
3252 WG_DLOG("type=%d\n", le32toh(wgm.wgm_type));
3253
3254 /*
3255 * Handle DATA packets promptly as they arrive. Other packets
3256 * may require expensive public-key crypto and are not as
3257 * sensitive to latency, so defer them to the worker thread.
3258 */
3259 switch (le32toh(wgm.wgm_type)) {
3260 case WG_MSG_TYPE_DATA:
3261 /* handle immediately */
3262 m_adj(m, offset);
3263 if (__predict_false(m->m_len < sizeof(struct wg_msg_data))) {
3264 m = m_pullup(m, sizeof(struct wg_msg_data));
3265 if (m == NULL)
3266 return -1;
3267 }
3268 wg_handle_msg_data(wg, m, src);
3269 *mp = NULL;
3270 return 1;
3271 case WG_MSG_TYPE_INIT:
3272 case WG_MSG_TYPE_RESP:
3273 case WG_MSG_TYPE_COOKIE:
3274 /* pass through to so_receive in wg_receive_packets */
3275 return 0;
3276 default:
3277 /* drop on the floor */
3278 m_freem(m);
3279 return -1;
3280 }
3281 }
3282
3283 static int
3284 wg_socreate(struct wg_softc *wg, int af, struct socket **sop)
3285 {
3286 int error;
3287 struct socket *so;
3288
3289 error = socreate(af, &so, SOCK_DGRAM, 0, curlwp, NULL);
3290 if (error != 0)
3291 return error;
3292
3293 solock(so);
3294 so->so_upcallarg = wg;
3295 so->so_upcall = wg_so_upcall;
3296 so->so_rcv.sb_flags |= SB_UPCALL;
3297 inpcb_register_overudp_cb(sotoinpcb(so), wg_overudp_cb, wg);
3298 sounlock(so);
3299
3300 *sop = so;
3301
3302 return 0;
3303 }
3304
3305 static bool
3306 wg_session_hit_limits(struct wg_session *wgs)
3307 {
3308
3309 /*
3310 * [W] 6.2: Transport Message Limits
3311 * "After REJECT-AFTER-MESSAGES transport data messages or after the
3312 * current secure session is REJECT-AFTER-TIME seconds old, whichever
3313 * comes first, WireGuard will refuse to send any more transport data
3314 * messages using the current secure session, ..."
3315 */
3316 KASSERT(wgs->wgs_time_established != 0);
3317 if ((time_uptime - wgs->wgs_time_established) > wg_reject_after_time) {
3318 WG_DLOG("The session hits REJECT_AFTER_TIME\n");
3319 return true;
3320 } else if (wg_session_get_send_counter(wgs) >
3321 wg_reject_after_messages) {
3322 WG_DLOG("The session hits REJECT_AFTER_MESSAGES\n");
3323 return true;
3324 }
3325
3326 return false;
3327 }
3328
3329 static void
3330 wgintr(void *cookie)
3331 {
3332 struct wg_peer *wgp;
3333 struct wg_session *wgs;
3334 struct mbuf *m;
3335 struct psref psref;
3336
3337 while ((m = pktq_dequeue(wg_pktq)) != NULL) {
3338 wgp = M_GETCTX(m, struct wg_peer *);
3339 if ((wgs = wg_get_stable_session(wgp, &psref)) == NULL) {
3340 WG_TRACE("no stable session");
3341 wg_schedule_peer_task(wgp, WGP_TASK_SEND_INIT_MESSAGE);
3342 goto next0;
3343 }
3344 if (__predict_false(wg_session_hit_limits(wgs))) {
3345 WG_TRACE("stable session hit limits");
3346 wg_schedule_peer_task(wgp, WGP_TASK_SEND_INIT_MESSAGE);
3347 goto next1;
3348 }
3349 wg_send_data_msg(wgp, wgs, m);
3350 m = NULL; /* consumed */
3351 next1: wg_put_session(wgs, &psref);
3352 next0: if (m)
3353 m_freem(m);
3354 /* XXX Yield to avoid userland starvation? */
3355 }
3356 }
3357
3358 static void
3359 wg_rekey_timer(void *arg)
3360 {
3361 struct wg_peer *wgp = arg;
3362
3363 wg_schedule_peer_task(wgp, WGP_TASK_SEND_INIT_MESSAGE);
3364 }
3365
3366 static void
3367 wg_purge_pending_packets(struct wg_peer *wgp)
3368 {
3369 struct mbuf *m;
3370
3371 if ((m = atomic_swap_ptr(&wgp->wgp_pending, NULL)) != NULL)
3372 m_freem(m);
3373 pktq_barrier(wg_pktq);
3374 }
3375
3376 static void
3377 wg_handshake_timeout_timer(void *arg)
3378 {
3379 struct wg_peer *wgp = arg;
3380
3381 WG_TRACE("enter");
3382
3383 wg_schedule_peer_task(wgp, WGP_TASK_RETRY_HANDSHAKE);
3384 }
3385
3386 static struct wg_peer *
3387 wg_alloc_peer(struct wg_softc *wg)
3388 {
3389 struct wg_peer *wgp;
3390
3391 wgp = kmem_zalloc(sizeof(*wgp), KM_SLEEP);
3392
3393 wgp->wgp_sc = wg;
3394 callout_init(&wgp->wgp_rekey_timer, CALLOUT_MPSAFE);
3395 callout_setfunc(&wgp->wgp_rekey_timer, wg_rekey_timer, wgp);
3396 callout_init(&wgp->wgp_handshake_timeout_timer, CALLOUT_MPSAFE);
3397 callout_setfunc(&wgp->wgp_handshake_timeout_timer,
3398 wg_handshake_timeout_timer, wgp);
3399 callout_init(&wgp->wgp_session_dtor_timer, CALLOUT_MPSAFE);
3400 callout_setfunc(&wgp->wgp_session_dtor_timer,
3401 wg_session_dtor_timer, wgp);
3402 PSLIST_ENTRY_INIT(wgp, wgp_peerlist_entry);
3403 wgp->wgp_endpoint_changing = false;
3404 wgp->wgp_endpoint_available = false;
3405 wgp->wgp_lock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NONE);
3406 wgp->wgp_intr_lock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_SOFTNET);
3407 wgp->wgp_psz = pserialize_create();
3408 psref_target_init(&wgp->wgp_psref, wg_psref_class);
3409
3410 wgp->wgp_endpoint = kmem_zalloc(sizeof(*wgp->wgp_endpoint), KM_SLEEP);
3411 wgp->wgp_endpoint0 = kmem_zalloc(sizeof(*wgp->wgp_endpoint0), KM_SLEEP);
3412 psref_target_init(&wgp->wgp_endpoint->wgsa_psref, wg_psref_class);
3413 psref_target_init(&wgp->wgp_endpoint0->wgsa_psref, wg_psref_class);
3414
3415 struct wg_session *wgs;
3416 wgp->wgp_session_stable =
3417 kmem_zalloc(sizeof(*wgp->wgp_session_stable), KM_SLEEP);
3418 wgp->wgp_session_unstable =
3419 kmem_zalloc(sizeof(*wgp->wgp_session_unstable), KM_SLEEP);
3420 wgs = wgp->wgp_session_stable;
3421 wgs->wgs_peer = wgp;
3422 wgs->wgs_state = WGS_STATE_UNKNOWN;
3423 psref_target_init(&wgs->wgs_psref, wg_psref_class);
3424 #ifndef __HAVE_ATOMIC64_LOADSTORE
3425 mutex_init(&wgs->wgs_send_counter_lock, MUTEX_DEFAULT, IPL_SOFTNET);
3426 #endif
3427 wgs->wgs_recvwin = kmem_zalloc(sizeof(*wgs->wgs_recvwin), KM_SLEEP);
3428 mutex_init(&wgs->wgs_recvwin->lock, MUTEX_DEFAULT, IPL_SOFTNET);
3429
3430 wgs = wgp->wgp_session_unstable;
3431 wgs->wgs_peer = wgp;
3432 wgs->wgs_state = WGS_STATE_UNKNOWN;
3433 psref_target_init(&wgs->wgs_psref, wg_psref_class);
3434 #ifndef __HAVE_ATOMIC64_LOADSTORE
3435 mutex_init(&wgs->wgs_send_counter_lock, MUTEX_DEFAULT, IPL_SOFTNET);
3436 #endif
3437 wgs->wgs_recvwin = kmem_zalloc(sizeof(*wgs->wgs_recvwin), KM_SLEEP);
3438 mutex_init(&wgs->wgs_recvwin->lock, MUTEX_DEFAULT, IPL_SOFTNET);
3439
3440 return wgp;
3441 }
3442
3443 static void
3444 wg_destroy_peer(struct wg_peer *wgp)
3445 {
3446 struct wg_session *wgs;
3447 struct wg_softc *wg = wgp->wgp_sc;
3448
3449 /* Prevent new packets from this peer on any source address. */
3450 rw_enter(wg->wg_rwlock, RW_WRITER);
3451 for (int i = 0; i < wgp->wgp_n_allowedips; i++) {
3452 struct wg_allowedip *wga = &wgp->wgp_allowedips[i];
3453 struct radix_node_head *rnh = wg_rnh(wg, wga->wga_family);
3454 struct radix_node *rn;
3455
3456 KASSERT(rnh != NULL);
3457 rn = rnh->rnh_deladdr(&wga->wga_sa_addr,
3458 &wga->wga_sa_mask, rnh);
3459 if (rn == NULL) {
3460 char addrstr[128];
3461 sockaddr_format(&wga->wga_sa_addr, addrstr,
3462 sizeof(addrstr));
3463 WGLOG(LOG_WARNING, "%s: Couldn't delete %s",
3464 if_name(&wg->wg_if), addrstr);
3465 }
3466 }
3467 rw_exit(wg->wg_rwlock);
3468
3469 /* Purge pending packets. */
3470 wg_purge_pending_packets(wgp);
3471
3472 /* Halt all packet processing and timeouts. */
3473 callout_halt(&wgp->wgp_rekey_timer, NULL);
3474 callout_halt(&wgp->wgp_handshake_timeout_timer, NULL);
3475 callout_halt(&wgp->wgp_session_dtor_timer, NULL);
3476
3477 /* Wait for any queued work to complete. */
3478 workqueue_wait(wg_wq, &wgp->wgp_work);
3479
3480 wgs = wgp->wgp_session_unstable;
3481 if (wgs->wgs_state != WGS_STATE_UNKNOWN) {
3482 mutex_enter(wgp->wgp_lock);
3483 wg_destroy_session(wg, wgs);
3484 mutex_exit(wgp->wgp_lock);
3485 }
3486 mutex_destroy(&wgs->wgs_recvwin->lock);
3487 kmem_free(wgs->wgs_recvwin, sizeof(*wgs->wgs_recvwin));
3488 #ifndef __HAVE_ATOMIC64_LOADSTORE
3489 mutex_destroy(&wgs->wgs_send_counter_lock);
3490 #endif
3491 kmem_free(wgs, sizeof(*wgs));
3492
3493 wgs = wgp->wgp_session_stable;
3494 if (wgs->wgs_state != WGS_STATE_UNKNOWN) {
3495 mutex_enter(wgp->wgp_lock);
3496 wg_destroy_session(wg, wgs);
3497 mutex_exit(wgp->wgp_lock);
3498 }
3499 mutex_destroy(&wgs->wgs_recvwin->lock);
3500 kmem_free(wgs->wgs_recvwin, sizeof(*wgs->wgs_recvwin));
3501 #ifndef __HAVE_ATOMIC64_LOADSTORE
3502 mutex_destroy(&wgs->wgs_send_counter_lock);
3503 #endif
3504 kmem_free(wgs, sizeof(*wgs));
3505
3506 psref_target_destroy(&wgp->wgp_endpoint->wgsa_psref, wg_psref_class);
3507 psref_target_destroy(&wgp->wgp_endpoint0->wgsa_psref, wg_psref_class);
3508 kmem_free(wgp->wgp_endpoint, sizeof(*wgp->wgp_endpoint));
3509 kmem_free(wgp->wgp_endpoint0, sizeof(*wgp->wgp_endpoint0));
3510
3511 pserialize_destroy(wgp->wgp_psz);
3512 mutex_obj_free(wgp->wgp_intr_lock);
3513 mutex_obj_free(wgp->wgp_lock);
3514
3515 kmem_free(wgp, sizeof(*wgp));
3516 }
3517
3518 static void
3519 wg_destroy_all_peers(struct wg_softc *wg)
3520 {
3521 struct wg_peer *wgp, *wgp0 __diagused;
3522 void *garbage_byname, *garbage_bypubkey;
3523
3524 restart:
3525 garbage_byname = garbage_bypubkey = NULL;
3526 mutex_enter(wg->wg_lock);
3527 WG_PEER_WRITER_FOREACH(wgp, wg) {
3528 if (wgp->wgp_name[0]) {
3529 wgp0 = thmap_del(wg->wg_peers_byname, wgp->wgp_name,
3530 strlen(wgp->wgp_name));
3531 KASSERT(wgp0 == wgp);
3532 garbage_byname = thmap_stage_gc(wg->wg_peers_byname);
3533 }
3534 wgp0 = thmap_del(wg->wg_peers_bypubkey, wgp->wgp_pubkey,
3535 sizeof(wgp->wgp_pubkey));
3536 KASSERT(wgp0 == wgp);
3537 garbage_bypubkey = thmap_stage_gc(wg->wg_peers_bypubkey);
3538 WG_PEER_WRITER_REMOVE(wgp);
3539 wg->wg_npeers--;
3540 mutex_enter(wgp->wgp_lock);
3541 pserialize_perform(wgp->wgp_psz);
3542 mutex_exit(wgp->wgp_lock);
3543 PSLIST_ENTRY_DESTROY(wgp, wgp_peerlist_entry);
3544 break;
3545 }
3546 mutex_exit(wg->wg_lock);
3547
3548 if (wgp == NULL)
3549 return;
3550
3551 psref_target_destroy(&wgp->wgp_psref, wg_psref_class);
3552
3553 wg_destroy_peer(wgp);
3554 thmap_gc(wg->wg_peers_byname, garbage_byname);
3555 thmap_gc(wg->wg_peers_bypubkey, garbage_bypubkey);
3556
3557 goto restart;
3558 }
3559
3560 static int
3561 wg_destroy_peer_name(struct wg_softc *wg, const char *name)
3562 {
3563 struct wg_peer *wgp, *wgp0 __diagused;
3564 void *garbage_byname, *garbage_bypubkey;
3565
3566 mutex_enter(wg->wg_lock);
3567 wgp = thmap_del(wg->wg_peers_byname, name, strlen(name));
3568 if (wgp != NULL) {
3569 wgp0 = thmap_del(wg->wg_peers_bypubkey, wgp->wgp_pubkey,
3570 sizeof(wgp->wgp_pubkey));
3571 KASSERT(wgp0 == wgp);
3572 garbage_byname = thmap_stage_gc(wg->wg_peers_byname);
3573 garbage_bypubkey = thmap_stage_gc(wg->wg_peers_bypubkey);
3574 WG_PEER_WRITER_REMOVE(wgp);
3575 wg->wg_npeers--;
3576 if (wg->wg_npeers == 0)
3577 if_link_state_change(&wg->wg_if, LINK_STATE_DOWN);
3578 mutex_enter(wgp->wgp_lock);
3579 pserialize_perform(wgp->wgp_psz);
3580 mutex_exit(wgp->wgp_lock);
3581 PSLIST_ENTRY_DESTROY(wgp, wgp_peerlist_entry);
3582 }
3583 mutex_exit(wg->wg_lock);
3584
3585 if (wgp == NULL)
3586 return ENOENT;
3587
3588 psref_target_destroy(&wgp->wgp_psref, wg_psref_class);
3589
3590 wg_destroy_peer(wgp);
3591 thmap_gc(wg->wg_peers_byname, garbage_byname);
3592 thmap_gc(wg->wg_peers_bypubkey, garbage_bypubkey);
3593
3594 return 0;
3595 }
3596
3597 static int
3598 wg_if_attach(struct wg_softc *wg)
3599 {
3600
3601 wg->wg_if.if_addrlen = 0;
3602 wg->wg_if.if_mtu = WG_MTU;
3603 wg->wg_if.if_flags = IFF_MULTICAST;
3604 wg->wg_if.if_extflags = IFEF_MPSAFE;
3605 wg->wg_if.if_ioctl = wg_ioctl;
3606 wg->wg_if.if_output = wg_output;
3607 wg->wg_if.if_init = wg_init;
3608 #ifdef ALTQ
3609 wg->wg_if.if_start = wg_start;
3610 #endif
3611 wg->wg_if.if_stop = wg_stop;
3612 wg->wg_if.if_type = IFT_OTHER;
3613 wg->wg_if.if_dlt = DLT_NULL;
3614 wg->wg_if.if_softc = wg;
3615 #ifdef ALTQ
3616 IFQ_SET_READY(&wg->wg_if.if_snd);
3617 #endif
3618 if_initialize(&wg->wg_if);
3619
3620 wg->wg_if.if_link_state = LINK_STATE_DOWN;
3621 if_alloc_sadl(&wg->wg_if);
3622 if_register(&wg->wg_if);
3623
3624 bpf_attach(&wg->wg_if, DLT_NULL, sizeof(uint32_t));
3625
3626 return 0;
3627 }
3628
3629 static void
3630 wg_if_detach(struct wg_softc *wg)
3631 {
3632 struct ifnet *ifp = &wg->wg_if;
3633
3634 bpf_detach(ifp);
3635 if_detach(ifp);
3636 }
3637
3638 static int
3639 wg_clone_create(struct if_clone *ifc, int unit)
3640 {
3641 struct wg_softc *wg;
3642 int error;
3643
3644 wg_guarantee_initialized();
3645
3646 error = wg_count_inc();
3647 if (error)
3648 return error;
3649
3650 wg = kmem_zalloc(sizeof(*wg), KM_SLEEP);
3651
3652 if_initname(&wg->wg_if, ifc->ifc_name, unit);
3653
3654 PSLIST_INIT(&wg->wg_peers);
3655 wg->wg_peers_bypubkey = thmap_create(0, NULL, THMAP_NOCOPY);
3656 wg->wg_peers_byname = thmap_create(0, NULL, THMAP_NOCOPY);
3657 wg->wg_sessions_byindex = thmap_create(0, NULL, THMAP_NOCOPY);
3658 wg->wg_lock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NONE);
3659 wg->wg_intr_lock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_SOFTNET);
3660 wg->wg_rwlock = rw_obj_alloc();
3661 threadpool_job_init(&wg->wg_job, wg_job, wg->wg_intr_lock,
3662 "%s", if_name(&wg->wg_if));
3663 wg->wg_ops = &wg_ops_rumpkernel;
3664
3665 error = threadpool_get(&wg->wg_threadpool, PRI_NONE);
3666 if (error)
3667 goto fail0;
3668
3669 #ifdef INET
3670 error = wg_socreate(wg, AF_INET, &wg->wg_so4);
3671 if (error)
3672 goto fail1;
3673 rn_inithead((void **)&wg->wg_rtable_ipv4,
3674 offsetof(struct sockaddr_in, sin_addr) * NBBY);
3675 #endif
3676 #ifdef INET6
3677 error = wg_socreate(wg, AF_INET6, &wg->wg_so6);
3678 if (error)
3679 goto fail2;
3680 rn_inithead((void **)&wg->wg_rtable_ipv6,
3681 offsetof(struct sockaddr_in6, sin6_addr) * NBBY);
3682 #endif
3683
3684 error = wg_if_attach(wg);
3685 if (error)
3686 goto fail3;
3687
3688 return 0;
3689
3690 fail4: __unused
3691 wg_if_detach(wg);
3692 fail3: wg_destroy_all_peers(wg);
3693 #ifdef INET6
3694 solock(wg->wg_so6);
3695 wg->wg_so6->so_rcv.sb_flags &= ~SB_UPCALL;
3696 sounlock(wg->wg_so6);
3697 #endif
3698 #ifdef INET
3699 solock(wg->wg_so4);
3700 wg->wg_so4->so_rcv.sb_flags &= ~SB_UPCALL;
3701 sounlock(wg->wg_so4);
3702 #endif
3703 mutex_enter(wg->wg_intr_lock);
3704 threadpool_cancel_job(wg->wg_threadpool, &wg->wg_job);
3705 mutex_exit(wg->wg_intr_lock);
3706 #ifdef INET6
3707 if (wg->wg_rtable_ipv6 != NULL)
3708 free(wg->wg_rtable_ipv6, M_RTABLE);
3709 soclose(wg->wg_so6);
3710 fail2:
3711 #endif
3712 #ifdef INET
3713 if (wg->wg_rtable_ipv4 != NULL)
3714 free(wg->wg_rtable_ipv4, M_RTABLE);
3715 soclose(wg->wg_so4);
3716 fail1:
3717 #endif
3718 threadpool_put(wg->wg_threadpool, PRI_NONE);
3719 fail0: threadpool_job_destroy(&wg->wg_job);
3720 rw_obj_free(wg->wg_rwlock);
3721 mutex_obj_free(wg->wg_intr_lock);
3722 mutex_obj_free(wg->wg_lock);
3723 thmap_destroy(wg->wg_sessions_byindex);
3724 thmap_destroy(wg->wg_peers_byname);
3725 thmap_destroy(wg->wg_peers_bypubkey);
3726 PSLIST_DESTROY(&wg->wg_peers);
3727 kmem_free(wg, sizeof(*wg));
3728 wg_count_dec();
3729 return error;
3730 }
3731
3732 static int
3733 wg_clone_destroy(struct ifnet *ifp)
3734 {
3735 struct wg_softc *wg = container_of(ifp, struct wg_softc, wg_if);
3736
3737 #ifdef WG_RUMPKERNEL
3738 if (wg_user_mode(wg)) {
3739 rumpuser_wg_destroy(wg->wg_user);
3740 wg->wg_user = NULL;
3741 }
3742 #endif
3743
3744 wg_if_detach(wg);
3745 wg_destroy_all_peers(wg);
3746 #ifdef INET6
3747 solock(wg->wg_so6);
3748 wg->wg_so6->so_rcv.sb_flags &= ~SB_UPCALL;
3749 sounlock(wg->wg_so6);
3750 #endif
3751 #ifdef INET
3752 solock(wg->wg_so4);
3753 wg->wg_so4->so_rcv.sb_flags &= ~SB_UPCALL;
3754 sounlock(wg->wg_so4);
3755 #endif
3756 mutex_enter(wg->wg_intr_lock);
3757 threadpool_cancel_job(wg->wg_threadpool, &wg->wg_job);
3758 mutex_exit(wg->wg_intr_lock);
3759 #ifdef INET6
3760 if (wg->wg_rtable_ipv6 != NULL)
3761 free(wg->wg_rtable_ipv6, M_RTABLE);
3762 soclose(wg->wg_so6);
3763 #endif
3764 #ifdef INET
3765 if (wg->wg_rtable_ipv4 != NULL)
3766 free(wg->wg_rtable_ipv4, M_RTABLE);
3767 soclose(wg->wg_so4);
3768 #endif
3769 threadpool_put(wg->wg_threadpool, PRI_NONE);
3770 threadpool_job_destroy(&wg->wg_job);
3771 rw_obj_free(wg->wg_rwlock);
3772 mutex_obj_free(wg->wg_intr_lock);
3773 mutex_obj_free(wg->wg_lock);
3774 thmap_destroy(wg->wg_sessions_byindex);
3775 thmap_destroy(wg->wg_peers_byname);
3776 thmap_destroy(wg->wg_peers_bypubkey);
3777 PSLIST_DESTROY(&wg->wg_peers);
3778 kmem_free(wg, sizeof(*wg));
3779 wg_count_dec();
3780
3781 return 0;
3782 }
3783
3784 static struct wg_peer *
3785 wg_pick_peer_by_sa(struct wg_softc *wg, const struct sockaddr *sa,
3786 struct psref *psref)
3787 {
3788 struct radix_node_head *rnh;
3789 struct radix_node *rn;
3790 struct wg_peer *wgp = NULL;
3791 struct wg_allowedip *wga;
3792
3793 #ifdef WG_DEBUG_LOG
3794 char addrstr[128];
3795 sockaddr_format(sa, addrstr, sizeof(addrstr));
3796 WG_DLOG("sa=%s\n", addrstr);
3797 #endif
3798
3799 rw_enter(wg->wg_rwlock, RW_READER);
3800
3801 rnh = wg_rnh(wg, sa->sa_family);
3802 if (rnh == NULL)
3803 goto out;
3804
3805 rn = rnh->rnh_matchaddr(sa, rnh);
3806 if (rn == NULL || (rn->rn_flags & RNF_ROOT) != 0)
3807 goto out;
3808
3809 WG_TRACE("success");
3810
3811 wga = container_of(rn, struct wg_allowedip, wga_nodes[0]);
3812 wgp = wga->wga_peer;
3813 wg_get_peer(wgp, psref);
3814
3815 out:
3816 rw_exit(wg->wg_rwlock);
3817 return wgp;
3818 }
3819
3820 static void
3821 wg_fill_msg_data(struct wg_softc *wg, struct wg_peer *wgp,
3822 struct wg_session *wgs, struct wg_msg_data *wgmd)
3823 {
3824
3825 memset(wgmd, 0, sizeof(*wgmd));
3826 wgmd->wgmd_type = htole32(WG_MSG_TYPE_DATA);
3827 wgmd->wgmd_receiver = wgs->wgs_remote_index;
3828 /* [W] 5.4.6: msg.counter := Nm^send */
3829 /* [W] 5.4.6: Nm^send := Nm^send + 1 */
3830 wgmd->wgmd_counter = htole64(wg_session_inc_send_counter(wgs));
3831 WG_DLOG("counter=%"PRIu64"\n", le64toh(wgmd->wgmd_counter));
3832 }
3833
3834 static int
3835 wg_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst,
3836 const struct rtentry *rt)
3837 {
3838 struct wg_softc *wg = ifp->if_softc;
3839 struct wg_peer *wgp = NULL;
3840 struct wg_session *wgs = NULL;
3841 struct psref wgp_psref, wgs_psref;
3842 int bound;
3843 int error;
3844
3845 bound = curlwp_bind();
3846
3847 /* TODO make the nest limit configurable via sysctl */
3848 error = if_tunnel_check_nesting(ifp, m, 1);
3849 if (error) {
3850 WGLOG(LOG_ERR,
3851 "%s: tunneling loop detected and packet dropped\n",
3852 if_name(&wg->wg_if));
3853 goto out0;
3854 }
3855
3856 #ifdef ALTQ
3857 bool altq = atomic_load_relaxed(&ifp->if_snd.altq_flags)
3858 & ALTQF_ENABLED;
3859 if (altq)
3860 IFQ_CLASSIFY(&ifp->if_snd, m, dst->sa_family);
3861 #endif
3862
3863 bpf_mtap_af(ifp, dst->sa_family, m, BPF_D_OUT);
3864
3865 m->m_flags &= ~(M_BCAST|M_MCAST);
3866
3867 wgp = wg_pick_peer_by_sa(wg, dst, &wgp_psref);
3868 if (wgp == NULL) {
3869 WG_TRACE("peer not found");
3870 error = EHOSTUNREACH;
3871 goto out0;
3872 }
3873
3874 /* Clear checksum-offload flags. */
3875 m->m_pkthdr.csum_flags = 0;
3876 m->m_pkthdr.csum_data = 0;
3877
3878 /* Check whether there's an established session. */
3879 wgs = wg_get_stable_session(wgp, &wgs_psref);
3880 if (wgs == NULL) {
3881 /*
3882 * No established session. If we're the first to try
3883 * sending data, schedule a handshake and queue the
3884 * packet for when the handshake is done; otherwise
3885 * just drop the packet and let the ongoing handshake
3886 * attempt continue. We could queue more data packets
3887 * but it's not clear that's worthwhile.
3888 */
3889 if (atomic_cas_ptr(&wgp->wgp_pending, NULL, m) == NULL) {
3890 m = NULL; /* consume */
3891 WG_TRACE("queued first packet; init handshake");
3892 wg_schedule_peer_task(wgp, WGP_TASK_SEND_INIT_MESSAGE);
3893 } else {
3894 WG_TRACE("first packet already queued, dropping");
3895 }
3896 goto out1;
3897 }
3898
3899 /* There's an established session. Toss it in the queue. */
3900 #ifdef ALTQ
3901 if (altq) {
3902 mutex_enter(ifp->if_snd.ifq_lock);
3903 if (ALTQ_IS_ENABLED(&ifp->if_snd)) {
3904 M_SETCTX(m, wgp);
3905 ALTQ_ENQUEUE(&ifp->if_snd, m, error);
3906 m = NULL; /* consume */
3907 }
3908 mutex_exit(ifp->if_snd.ifq_lock);
3909 if (m == NULL) {
3910 wg_start(ifp);
3911 goto out2;
3912 }
3913 }
3914 #endif
3915 kpreempt_disable();
3916 const uint32_t h = curcpu()->ci_index; // pktq_rps_hash(m)
3917 M_SETCTX(m, wgp);
3918 if (__predict_false(!pktq_enqueue(wg_pktq, m, h))) {
3919 WGLOG(LOG_ERR, "%s: pktq full, dropping\n",
3920 if_name(&wg->wg_if));
3921 error = ENOBUFS;
3922 goto out3;
3923 }
3924 m = NULL; /* consumed */
3925 error = 0;
3926 out3: kpreempt_enable();
3927
3928 #ifdef ALTQ
3929 out2:
3930 #endif
3931 wg_put_session(wgs, &wgs_psref);
3932 out1: wg_put_peer(wgp, &wgp_psref);
3933 out0: if (m)
3934 m_freem(m);
3935 curlwp_bindx(bound);
3936 return error;
3937 }
3938
3939 static int
3940 wg_send_udp(struct wg_peer *wgp, struct mbuf *m)
3941 {
3942 struct psref psref;
3943 struct wg_sockaddr *wgsa;
3944 int error;
3945 struct socket *so;
3946
3947 wgsa = wg_get_endpoint_sa(wgp, &psref);
3948 so = wg_get_so_by_peer(wgp, wgsa);
3949 solock(so);
3950 if (wgsatosa(wgsa)->sa_family == AF_INET) {
3951 error = udp_send(so, m, wgsatosa(wgsa), NULL, curlwp);
3952 } else {
3953 #ifdef INET6
3954 error = udp6_output(sotoinpcb(so), m, wgsatosin6(wgsa),
3955 NULL, curlwp);
3956 #else
3957 m_freem(m);
3958 error = EPFNOSUPPORT;
3959 #endif
3960 }
3961 sounlock(so);
3962 wg_put_sa(wgp, wgsa, &psref);
3963
3964 return error;
3965 }
3966
3967 /* Inspired by pppoe_get_mbuf */
3968 static struct mbuf *
3969 wg_get_mbuf(size_t leading_len, size_t len)
3970 {
3971 struct mbuf *m;
3972
3973 KASSERT(leading_len <= MCLBYTES);
3974 KASSERT(len <= MCLBYTES - leading_len);
3975
3976 m = m_gethdr(M_DONTWAIT, MT_DATA);
3977 if (m == NULL)
3978 return NULL;
3979 if (len + leading_len > MHLEN) {
3980 m_clget(m, M_DONTWAIT);
3981 if ((m->m_flags & M_EXT) == 0) {
3982 m_free(m);
3983 return NULL;
3984 }
3985 }
3986 m->m_data += leading_len;
3987 m->m_pkthdr.len = m->m_len = len;
3988
3989 return m;
3990 }
3991
3992 static int
3993 wg_send_data_msg(struct wg_peer *wgp, struct wg_session *wgs,
3994 struct mbuf *m)
3995 {
3996 struct wg_softc *wg = wgp->wgp_sc;
3997 int error;
3998 size_t inner_len, padded_len, encrypted_len;
3999 char *padded_buf = NULL;
4000 size_t mlen;
4001 struct wg_msg_data *wgmd;
4002 bool free_padded_buf = false;
4003 struct mbuf *n;
4004 size_t leading_len = max_hdr + sizeof(struct udphdr);
4005
4006 mlen = m_length(m);
4007 inner_len = mlen;
4008 padded_len = roundup(mlen, 16);
4009 encrypted_len = padded_len + WG_AUTHTAG_LEN;
4010 WG_DLOG("inner=%lu, padded=%lu, encrypted_len=%lu\n",
4011 inner_len, padded_len, encrypted_len);
4012 if (mlen != 0) {
4013 bool success;
4014 success = m_ensure_contig(&m, padded_len);
4015 if (success) {
4016 padded_buf = mtod(m, char *);
4017 } else {
4018 padded_buf = kmem_intr_alloc(padded_len, KM_NOSLEEP);
4019 if (padded_buf == NULL) {
4020 error = ENOBUFS;
4021 goto end;
4022 }
4023 free_padded_buf = true;
4024 m_copydata(m, 0, mlen, padded_buf);
4025 }
4026 memset(padded_buf + mlen, 0, padded_len - inner_len);
4027 }
4028
4029 n = wg_get_mbuf(leading_len, sizeof(*wgmd) + encrypted_len);
4030 if (n == NULL) {
4031 error = ENOBUFS;
4032 goto end;
4033 }
4034 KASSERT(n->m_len >= sizeof(*wgmd));
4035 wgmd = mtod(n, struct wg_msg_data *);
4036 wg_fill_msg_data(wg, wgp, wgs, wgmd);
4037 /* [W] 5.4.6: AEAD(Tm^send, Nm^send, P, e) */
4038 wg_algo_aead_enc((char *)wgmd + sizeof(*wgmd), encrypted_len,
4039 wgs->wgs_tkey_send, le64toh(wgmd->wgmd_counter),
4040 padded_buf, padded_len,
4041 NULL, 0);
4042
4043 error = wg->wg_ops->send_data_msg(wgp, n);
4044 if (error == 0) {
4045 struct ifnet *ifp = &wg->wg_if;
4046 if_statadd(ifp, if_obytes, mlen);
4047 if_statinc(ifp, if_opackets);
4048 if (wgs->wgs_is_initiator &&
4049 wgs->wgs_time_last_data_sent == 0) {
4050 /*
4051 * [W] 6.2 Transport Message Limits
4052 * "if a peer is the initiator of a current secure
4053 * session, WireGuard will send a handshake initiation
4054 * message to begin a new secure session if, after
4055 * transmitting a transport data message, the current
4056 * secure session is REKEY-AFTER-TIME seconds old,"
4057 */
4058 wg_schedule_rekey_timer(wgp);
4059 }
4060 wgs->wgs_time_last_data_sent = time_uptime;
4061 if (wg_session_get_send_counter(wgs) >=
4062 wg_rekey_after_messages) {
4063 /*
4064 * [W] 6.2 Transport Message Limits
4065 * "WireGuard will try to create a new session, by
4066 * sending a handshake initiation message (section
4067 * 5.4.2), after it has sent REKEY-AFTER-MESSAGES
4068 * transport data messages..."
4069 */
4070 wg_schedule_peer_task(wgp, WGP_TASK_SEND_INIT_MESSAGE);
4071 }
4072 }
4073 end:
4074 m_freem(m);
4075 if (free_padded_buf)
4076 kmem_intr_free(padded_buf, padded_len);
4077 return error;
4078 }
4079
4080 static void
4081 wg_input(struct ifnet *ifp, struct mbuf *m, const int af)
4082 {
4083 pktqueue_t *pktq;
4084 size_t pktlen;
4085
4086 KASSERT(af == AF_INET || af == AF_INET6);
4087
4088 WG_TRACE("");
4089
4090 m_set_rcvif(m, ifp);
4091 pktlen = m->m_pkthdr.len;
4092
4093 bpf_mtap_af(ifp, af, m, BPF_D_IN);
4094
4095 switch (af) {
4096 case AF_INET:
4097 pktq = ip_pktq;
4098 break;
4099 #ifdef INET6
4100 case AF_INET6:
4101 pktq = ip6_pktq;
4102 break;
4103 #endif
4104 default:
4105 panic("invalid af=%d", af);
4106 }
4107
4108 kpreempt_disable();
4109 const u_int h = curcpu()->ci_index;
4110 if (__predict_true(pktq_enqueue(pktq, m, h))) {
4111 if_statadd(ifp, if_ibytes, pktlen);
4112 if_statinc(ifp, if_ipackets);
4113 } else {
4114 m_freem(m);
4115 }
4116 kpreempt_enable();
4117 }
4118
4119 static void
4120 wg_calc_pubkey(uint8_t pubkey[WG_STATIC_KEY_LEN],
4121 const uint8_t privkey[WG_STATIC_KEY_LEN])
4122 {
4123
4124 crypto_scalarmult_base(pubkey, privkey);
4125 }
4126
4127 static int
4128 wg_rtable_add_route(struct wg_softc *wg, struct wg_allowedip *wga)
4129 {
4130 struct radix_node_head *rnh;
4131 struct radix_node *rn;
4132 int error = 0;
4133
4134 rw_enter(wg->wg_rwlock, RW_WRITER);
4135 rnh = wg_rnh(wg, wga->wga_family);
4136 KASSERT(rnh != NULL);
4137 rn = rnh->rnh_addaddr(&wga->wga_sa_addr, &wga->wga_sa_mask, rnh,
4138 wga->wga_nodes);
4139 rw_exit(wg->wg_rwlock);
4140
4141 if (rn == NULL)
4142 error = EEXIST;
4143
4144 return error;
4145 }
4146
4147 static int
4148 wg_handle_prop_peer(struct wg_softc *wg, prop_dictionary_t peer,
4149 struct wg_peer **wgpp)
4150 {
4151 int error = 0;
4152 const void *pubkey;
4153 size_t pubkey_len;
4154 const void *psk;
4155 size_t psk_len;
4156 const char *name = NULL;
4157
4158 if (prop_dictionary_get_string(peer, "name", &name)) {
4159 if (strlen(name) > WG_PEER_NAME_MAXLEN) {
4160 error = EINVAL;
4161 goto out;
4162 }
4163 }
4164
4165 if (!prop_dictionary_get_data(peer, "public_key",
4166 &pubkey, &pubkey_len)) {
4167 error = EINVAL;
4168 goto out;
4169 }
4170 #ifdef WG_DEBUG_DUMP
4171 {
4172 char *hex = gethexdump(pubkey, pubkey_len);
4173 log(LOG_DEBUG, "pubkey=%p, pubkey_len=%lu\n%s\n",
4174 pubkey, pubkey_len, hex);
4175 puthexdump(hex, pubkey, pubkey_len);
4176 }
4177 #endif
4178
4179 struct wg_peer *wgp = wg_alloc_peer(wg);
4180 memcpy(wgp->wgp_pubkey, pubkey, sizeof(wgp->wgp_pubkey));
4181 if (name != NULL)
4182 strncpy(wgp->wgp_name, name, sizeof(wgp->wgp_name));
4183
4184 if (prop_dictionary_get_data(peer, "preshared_key", &psk, &psk_len)) {
4185 if (psk_len != sizeof(wgp->wgp_psk)) {
4186 error = EINVAL;
4187 goto out;
4188 }
4189 memcpy(wgp->wgp_psk, psk, sizeof(wgp->wgp_psk));
4190 }
4191
4192 const void *addr;
4193 size_t addr_len;
4194 struct wg_sockaddr *wgsa = wgp->wgp_endpoint;
4195
4196 if (!prop_dictionary_get_data(peer, "endpoint", &addr, &addr_len))
4197 goto skip_endpoint;
4198 if (addr_len < sizeof(*wgsatosa(wgsa)) ||
4199 addr_len > sizeof(*wgsatoss(wgsa))) {
4200 error = EINVAL;
4201 goto out;
4202 }
4203 memcpy(wgsatoss(wgsa), addr, addr_len);
4204 switch (wgsa_family(wgsa)) {
4205 case AF_INET:
4206 #ifdef INET6
4207 case AF_INET6:
4208 #endif
4209 break;
4210 default:
4211 error = EPFNOSUPPORT;
4212 goto out;
4213 }
4214 if (addr_len != sockaddr_getsize_by_family(wgsa_family(wgsa))) {
4215 error = EINVAL;
4216 goto out;
4217 }
4218 {
4219 char addrstr[128];
4220 sockaddr_format(wgsatosa(wgsa), addrstr, sizeof(addrstr));
4221 WG_DLOG("addr=%s\n", addrstr);
4222 }
4223 wgp->wgp_endpoint_available = true;
4224
4225 prop_array_t allowedips;
4226 skip_endpoint:
4227 allowedips = prop_dictionary_get(peer, "allowedips");
4228 if (allowedips == NULL)
4229 goto skip;
4230
4231 prop_object_iterator_t _it = prop_array_iterator(allowedips);
4232 prop_dictionary_t prop_allowedip;
4233 int j = 0;
4234 while ((prop_allowedip = prop_object_iterator_next(_it)) != NULL) {
4235 struct wg_allowedip *wga = &wgp->wgp_allowedips[j];
4236
4237 if (!prop_dictionary_get_int(prop_allowedip, "family",
4238 &wga->wga_family))
4239 continue;
4240 if (!prop_dictionary_get_data(prop_allowedip, "ip",
4241 &addr, &addr_len))
4242 continue;
4243 if (!prop_dictionary_get_uint8(prop_allowedip, "cidr",
4244 &wga->wga_cidr))
4245 continue;
4246
4247 switch (wga->wga_family) {
4248 case AF_INET: {
4249 struct sockaddr_in sin;
4250 char addrstr[128];
4251 struct in_addr mask;
4252 struct sockaddr_in sin_mask;
4253
4254 if (addr_len != sizeof(struct in_addr))
4255 return EINVAL;
4256 memcpy(&wga->wga_addr4, addr, addr_len);
4257
4258 sockaddr_in_init(&sin, (const struct in_addr *)addr,
4259 0);
4260 sockaddr_copy(&wga->wga_sa_addr,
4261 sizeof(sin), sintosa(&sin));
4262
4263 sockaddr_format(sintosa(&sin),
4264 addrstr, sizeof(addrstr));
4265 WG_DLOG("addr=%s/%d\n", addrstr, wga->wga_cidr);
4266
4267 in_len2mask(&mask, wga->wga_cidr);
4268 sockaddr_in_init(&sin_mask, &mask, 0);
4269 sockaddr_copy(&wga->wga_sa_mask,
4270 sizeof(sin_mask), sintosa(&sin_mask));
4271
4272 break;
4273 }
4274 #ifdef INET6
4275 case AF_INET6: {
4276 struct sockaddr_in6 sin6;
4277 char addrstr[128];
4278 struct in6_addr mask;
4279 struct sockaddr_in6 sin6_mask;
4280
4281 if (addr_len != sizeof(struct in6_addr))
4282 return EINVAL;
4283 memcpy(&wga->wga_addr6, addr, addr_len);
4284
4285 sockaddr_in6_init(&sin6, (const struct in6_addr *)addr,
4286 0, 0, 0);
4287 sockaddr_copy(&wga->wga_sa_addr,
4288 sizeof(sin6), sin6tosa(&sin6));
4289
4290 sockaddr_format(sin6tosa(&sin6),
4291 addrstr, sizeof(addrstr));
4292 WG_DLOG("addr=%s/%d\n", addrstr, wga->wga_cidr);
4293
4294 in6_prefixlen2mask(&mask, wga->wga_cidr);
4295 sockaddr_in6_init(&sin6_mask, &mask, 0, 0, 0);
4296 sockaddr_copy(&wga->wga_sa_mask,
4297 sizeof(sin6_mask), sin6tosa(&sin6_mask));
4298
4299 break;
4300 }
4301 #endif
4302 default:
4303 error = EINVAL;
4304 goto out;
4305 }
4306 wga->wga_peer = wgp;
4307
4308 error = wg_rtable_add_route(wg, wga);
4309 if (error != 0)
4310 goto out;
4311
4312 j++;
4313 }
4314 wgp->wgp_n_allowedips = j;
4315 skip:
4316 *wgpp = wgp;
4317 out:
4318 return error;
4319 }
4320
4321 static int
4322 wg_alloc_prop_buf(char **_buf, struct ifdrv *ifd)
4323 {
4324 int error;
4325 char *buf;
4326
4327 WG_DLOG("buf=%p, len=%lu\n", ifd->ifd_data, ifd->ifd_len);
4328 if (ifd->ifd_len >= WG_MAX_PROPLEN)
4329 return E2BIG;
4330 buf = kmem_alloc(ifd->ifd_len + 1, KM_SLEEP);
4331 error = copyin(ifd->ifd_data, buf, ifd->ifd_len);
4332 if (error != 0)
4333 return error;
4334 buf[ifd->ifd_len] = '\0';
4335 #ifdef WG_DEBUG_DUMP
4336 log(LOG_DEBUG, "%.*s\n",
4337 (int)MIN(INT_MAX, ifd->ifd_len),
4338 (const char *)buf);
4339 #endif
4340 *_buf = buf;
4341 return 0;
4342 }
4343
4344 static int
4345 wg_ioctl_set_private_key(struct wg_softc *wg, struct ifdrv *ifd)
4346 {
4347 int error;
4348 prop_dictionary_t prop_dict;
4349 char *buf = NULL;
4350 const void *privkey;
4351 size_t privkey_len;
4352
4353 error = wg_alloc_prop_buf(&buf, ifd);
4354 if (error != 0)
4355 return error;
4356 error = EINVAL;
4357 prop_dict = prop_dictionary_internalize(buf);
4358 if (prop_dict == NULL)
4359 goto out;
4360 if (!prop_dictionary_get_data(prop_dict, "private_key",
4361 &privkey, &privkey_len))
4362 goto out;
4363 #ifdef WG_DEBUG_DUMP
4364 {
4365 char *hex = gethexdump(privkey, privkey_len);
4366 log(LOG_DEBUG, "privkey=%p, privkey_len=%lu\n%s\n",
4367 privkey, privkey_len, hex);
4368 puthexdump(hex, privkey, privkey_len);
4369 }
4370 #endif
4371 if (privkey_len != WG_STATIC_KEY_LEN)
4372 goto out;
4373 memcpy(wg->wg_privkey, privkey, WG_STATIC_KEY_LEN);
4374 wg_calc_pubkey(wg->wg_pubkey, wg->wg_privkey);
4375 error = 0;
4376
4377 out:
4378 kmem_free(buf, ifd->ifd_len + 1);
4379 return error;
4380 }
4381
4382 static int
4383 wg_ioctl_set_listen_port(struct wg_softc *wg, struct ifdrv *ifd)
4384 {
4385 int error;
4386 prop_dictionary_t prop_dict;
4387 char *buf = NULL;
4388 uint16_t port;
4389
4390 error = wg_alloc_prop_buf(&buf, ifd);
4391 if (error != 0)
4392 return error;
4393 error = EINVAL;
4394 prop_dict = prop_dictionary_internalize(buf);
4395 if (prop_dict == NULL)
4396 goto out;
4397 if (!prop_dictionary_get_uint16(prop_dict, "listen_port", &port))
4398 goto out;
4399
4400 error = wg->wg_ops->bind_port(wg, (uint16_t)port);
4401
4402 out:
4403 kmem_free(buf, ifd->ifd_len + 1);
4404 return error;
4405 }
4406
4407 static int
4408 wg_ioctl_add_peer(struct wg_softc *wg, struct ifdrv *ifd)
4409 {
4410 int error;
4411 prop_dictionary_t prop_dict;
4412 char *buf = NULL;
4413 struct wg_peer *wgp = NULL, *wgp0 __diagused;
4414
4415 error = wg_alloc_prop_buf(&buf, ifd);
4416 if (error != 0)
4417 return error;
4418 error = EINVAL;
4419 prop_dict = prop_dictionary_internalize(buf);
4420 if (prop_dict == NULL)
4421 goto out;
4422
4423 error = wg_handle_prop_peer(wg, prop_dict, &wgp);
4424 if (error != 0)
4425 goto out;
4426
4427 mutex_enter(wg->wg_lock);
4428 if (thmap_get(wg->wg_peers_bypubkey, wgp->wgp_pubkey,
4429 sizeof(wgp->wgp_pubkey)) != NULL ||
4430 (wgp->wgp_name[0] &&
4431 thmap_get(wg->wg_peers_byname, wgp->wgp_name,
4432 strlen(wgp->wgp_name)) != NULL)) {
4433 mutex_exit(wg->wg_lock);
4434 wg_destroy_peer(wgp);
4435 error = EEXIST;
4436 goto out;
4437 }
4438 wgp0 = thmap_put(wg->wg_peers_bypubkey, wgp->wgp_pubkey,
4439 sizeof(wgp->wgp_pubkey), wgp);
4440 KASSERT(wgp0 == wgp);
4441 if (wgp->wgp_name[0]) {
4442 wgp0 = thmap_put(wg->wg_peers_byname, wgp->wgp_name,
4443 strlen(wgp->wgp_name), wgp);
4444 KASSERT(wgp0 == wgp);
4445 }
4446 WG_PEER_WRITER_INSERT_HEAD(wgp, wg);
4447 wg->wg_npeers++;
4448 mutex_exit(wg->wg_lock);
4449
4450 if_link_state_change(&wg->wg_if, LINK_STATE_UP);
4451
4452 out:
4453 kmem_free(buf, ifd->ifd_len + 1);
4454 return error;
4455 }
4456
4457 static int
4458 wg_ioctl_delete_peer(struct wg_softc *wg, struct ifdrv *ifd)
4459 {
4460 int error;
4461 prop_dictionary_t prop_dict;
4462 char *buf = NULL;
4463 const char *name;
4464
4465 error = wg_alloc_prop_buf(&buf, ifd);
4466 if (error != 0)
4467 return error;
4468 error = EINVAL;
4469 prop_dict = prop_dictionary_internalize(buf);
4470 if (prop_dict == NULL)
4471 goto out;
4472
4473 if (!prop_dictionary_get_string(prop_dict, "name", &name))
4474 goto out;
4475 if (strlen(name) > WG_PEER_NAME_MAXLEN)
4476 goto out;
4477
4478 error = wg_destroy_peer_name(wg, name);
4479 out:
4480 kmem_free(buf, ifd->ifd_len + 1);
4481 return error;
4482 }
4483
4484 static bool
4485 wg_is_authorized(struct wg_softc *wg, u_long cmd)
4486 {
4487 int au = cmd == SIOCGDRVSPEC ?
4488 KAUTH_REQ_NETWORK_INTERFACE_WG_GETPRIV :
4489 KAUTH_REQ_NETWORK_INTERFACE_WG_SETPRIV;
4490 return kauth_authorize_network(kauth_cred_get(),
4491 KAUTH_NETWORK_INTERFACE_WG, au, &wg->wg_if,
4492 (void *)cmd, NULL) == 0;
4493 }
4494
4495 static int
4496 wg_ioctl_get(struct wg_softc *wg, struct ifdrv *ifd)
4497 {
4498 int error = ENOMEM;
4499 prop_dictionary_t prop_dict;
4500 prop_array_t peers = NULL;
4501 char *buf;
4502 struct wg_peer *wgp;
4503 int s, i;
4504
4505 prop_dict = prop_dictionary_create();
4506 if (prop_dict == NULL)
4507 goto error;
4508
4509 if (wg_is_authorized(wg, SIOCGDRVSPEC)) {
4510 if (!prop_dictionary_set_data(prop_dict, "private_key",
4511 wg->wg_privkey, WG_STATIC_KEY_LEN))
4512 goto error;
4513 }
4514
4515 if (wg->wg_listen_port != 0) {
4516 if (!prop_dictionary_set_uint16(prop_dict, "listen_port",
4517 wg->wg_listen_port))
4518 goto error;
4519 }
4520
4521 if (wg->wg_npeers == 0)
4522 goto skip_peers;
4523
4524 peers = prop_array_create();
4525 if (peers == NULL)
4526 goto error;
4527
4528 s = pserialize_read_enter();
4529 i = 0;
4530 WG_PEER_READER_FOREACH(wgp, wg) {
4531 struct wg_sockaddr *wgsa;
4532 struct psref wgp_psref, wgsa_psref;
4533 prop_dictionary_t prop_peer;
4534
4535 wg_get_peer(wgp, &wgp_psref);
4536 pserialize_read_exit(s);
4537
4538 prop_peer = prop_dictionary_create();
4539 if (prop_peer == NULL)
4540 goto next;
4541
4542 if (strlen(wgp->wgp_name) > 0) {
4543 if (!prop_dictionary_set_string(prop_peer, "name",
4544 wgp->wgp_name))
4545 goto next;
4546 }
4547
4548 if (!prop_dictionary_set_data(prop_peer, "public_key",
4549 wgp->wgp_pubkey, sizeof(wgp->wgp_pubkey)))
4550 goto next;
4551
4552 uint8_t psk_zero[WG_PRESHARED_KEY_LEN] = {0};
4553 if (!consttime_memequal(wgp->wgp_psk, psk_zero,
4554 sizeof(wgp->wgp_psk))) {
4555 if (wg_is_authorized(wg, SIOCGDRVSPEC)) {
4556 if (!prop_dictionary_set_data(prop_peer,
4557 "preshared_key",
4558 wgp->wgp_psk, sizeof(wgp->wgp_psk)))
4559 goto next;
4560 }
4561 }
4562
4563 wgsa = wg_get_endpoint_sa(wgp, &wgsa_psref);
4564 CTASSERT(AF_UNSPEC == 0);
4565 if (wgsa_family(wgsa) != 0 /*AF_UNSPEC*/ &&
4566 !prop_dictionary_set_data(prop_peer, "endpoint",
4567 wgsatoss(wgsa),
4568 sockaddr_getsize_by_family(wgsa_family(wgsa)))) {
4569 wg_put_sa(wgp, wgsa, &wgsa_psref);
4570 goto next;
4571 }
4572 wg_put_sa(wgp, wgsa, &wgsa_psref);
4573
4574 const struct timespec *t = &wgp->wgp_last_handshake_time;
4575
4576 if (!prop_dictionary_set_uint64(prop_peer,
4577 "last_handshake_time_sec", (uint64_t)t->tv_sec))
4578 goto next;
4579 if (!prop_dictionary_set_uint32(prop_peer,
4580 "last_handshake_time_nsec", (uint32_t)t->tv_nsec))
4581 goto next;
4582
4583 if (wgp->wgp_n_allowedips == 0)
4584 goto skip_allowedips;
4585
4586 prop_array_t allowedips = prop_array_create();
4587 if (allowedips == NULL)
4588 goto next;
4589 for (int j = 0; j < wgp->wgp_n_allowedips; j++) {
4590 struct wg_allowedip *wga = &wgp->wgp_allowedips[j];
4591 prop_dictionary_t prop_allowedip;
4592
4593 prop_allowedip = prop_dictionary_create();
4594 if (prop_allowedip == NULL)
4595 break;
4596
4597 if (!prop_dictionary_set_int(prop_allowedip, "family",
4598 wga->wga_family))
4599 goto _next;
4600 if (!prop_dictionary_set_uint8(prop_allowedip, "cidr",
4601 wga->wga_cidr))
4602 goto _next;
4603
4604 switch (wga->wga_family) {
4605 case AF_INET:
4606 if (!prop_dictionary_set_data(prop_allowedip,
4607 "ip", &wga->wga_addr4,
4608 sizeof(wga->wga_addr4)))
4609 goto _next;
4610 break;
4611 #ifdef INET6
4612 case AF_INET6:
4613 if (!prop_dictionary_set_data(prop_allowedip,
4614 "ip", &wga->wga_addr6,
4615 sizeof(wga->wga_addr6)))
4616 goto _next;
4617 break;
4618 #endif
4619 default:
4620 break;
4621 }
4622 prop_array_set(allowedips, j, prop_allowedip);
4623 _next:
4624 prop_object_release(prop_allowedip);
4625 }
4626 prop_dictionary_set(prop_peer, "allowedips", allowedips);
4627 prop_object_release(allowedips);
4628
4629 skip_allowedips:
4630
4631 prop_array_set(peers, i, prop_peer);
4632 next:
4633 if (prop_peer)
4634 prop_object_release(prop_peer);
4635 i++;
4636
4637 s = pserialize_read_enter();
4638 wg_put_peer(wgp, &wgp_psref);
4639 }
4640 pserialize_read_exit(s);
4641
4642 prop_dictionary_set(prop_dict, "peers", peers);
4643 prop_object_release(peers);
4644 peers = NULL;
4645
4646 skip_peers:
4647 buf = prop_dictionary_externalize(prop_dict);
4648 if (buf == NULL)
4649 goto error;
4650 if (ifd->ifd_len < (strlen(buf) + 1)) {
4651 error = EINVAL;
4652 goto error;
4653 }
4654 error = copyout(buf, ifd->ifd_data, strlen(buf) + 1);
4655
4656 free(buf, 0);
4657 error:
4658 if (peers != NULL)
4659 prop_object_release(peers);
4660 if (prop_dict != NULL)
4661 prop_object_release(prop_dict);
4662
4663 return error;
4664 }
4665
4666 static int
4667 wg_ioctl(struct ifnet *ifp, u_long cmd, void *data)
4668 {
4669 struct wg_softc *wg = ifp->if_softc;
4670 struct ifreq *ifr = data;
4671 struct ifaddr *ifa = data;
4672 struct ifdrv *ifd = data;
4673 int error = 0;
4674
4675 switch (cmd) {
4676 case SIOCINITIFADDR:
4677 if (ifa->ifa_addr->sa_family != AF_LINK &&
4678 (ifp->if_flags & (IFF_UP | IFF_RUNNING)) !=
4679 (IFF_UP | IFF_RUNNING)) {
4680 ifp->if_flags |= IFF_UP;
4681 error = if_init(ifp);
4682 }
4683 return error;
4684 case SIOCADDMULTI:
4685 case SIOCDELMULTI:
4686 switch (ifr->ifr_addr.sa_family) {
4687 case AF_INET: /* IP supports Multicast */
4688 break;
4689 #ifdef INET6
4690 case AF_INET6: /* IP6 supports Multicast */
4691 break;
4692 #endif
4693 default: /* Other protocols doesn't support Multicast */
4694 error = EAFNOSUPPORT;
4695 break;
4696 }
4697 return error;
4698 case SIOCSDRVSPEC:
4699 if (!wg_is_authorized(wg, cmd)) {
4700 return EPERM;
4701 }
4702 switch (ifd->ifd_cmd) {
4703 case WG_IOCTL_SET_PRIVATE_KEY:
4704 error = wg_ioctl_set_private_key(wg, ifd);
4705 break;
4706 case WG_IOCTL_SET_LISTEN_PORT:
4707 error = wg_ioctl_set_listen_port(wg, ifd);
4708 break;
4709 case WG_IOCTL_ADD_PEER:
4710 error = wg_ioctl_add_peer(wg, ifd);
4711 break;
4712 case WG_IOCTL_DELETE_PEER:
4713 error = wg_ioctl_delete_peer(wg, ifd);
4714 break;
4715 default:
4716 error = EINVAL;
4717 break;
4718 }
4719 return error;
4720 case SIOCGDRVSPEC:
4721 return wg_ioctl_get(wg, ifd);
4722 case SIOCSIFFLAGS:
4723 if ((error = ifioctl_common(ifp, cmd, data)) != 0)
4724 break;
4725 switch (ifp->if_flags & (IFF_UP|IFF_RUNNING)) {
4726 case IFF_RUNNING:
4727 /*
4728 * If interface is marked down and it is running,
4729 * then stop and disable it.
4730 */
4731 if_stop(ifp, 1);
4732 break;
4733 case IFF_UP:
4734 /*
4735 * If interface is marked up and it is stopped, then
4736 * start it.
4737 */
4738 error = if_init(ifp);
4739 break;
4740 default:
4741 break;
4742 }
4743 return error;
4744 #ifdef WG_RUMPKERNEL
4745 case SIOCSLINKSTR:
4746 error = wg_ioctl_linkstr(wg, ifd);
4747 if (error == 0)
4748 wg->wg_ops = &wg_ops_rumpuser;
4749 return error;
4750 #endif
4751 default:
4752 break;
4753 }
4754
4755 error = ifioctl_common(ifp, cmd, data);
4756
4757 #ifdef WG_RUMPKERNEL
4758 if (!wg_user_mode(wg))
4759 return error;
4760
4761 /* Do the same to the corresponding tun device on the host */
4762 /*
4763 * XXX Actually the command has not been handled yet. It
4764 * will be handled via pr_ioctl form doifioctl later.
4765 */
4766 switch (cmd) {
4767 case SIOCAIFADDR:
4768 case SIOCDIFADDR: {
4769 struct in_aliasreq _ifra = *(const struct in_aliasreq *)data;
4770 struct in_aliasreq *ifra = &_ifra;
4771 KASSERT(error == ENOTTY);
4772 strncpy(ifra->ifra_name, rumpuser_wg_get_tunname(wg->wg_user),
4773 IFNAMSIZ);
4774 error = rumpuser_wg_ioctl(wg->wg_user, cmd, ifra, AF_INET);
4775 if (error == 0)
4776 error = ENOTTY;
4777 break;
4778 }
4779 #ifdef INET6
4780 case SIOCAIFADDR_IN6:
4781 case SIOCDIFADDR_IN6: {
4782 struct in6_aliasreq _ifra = *(const struct in6_aliasreq *)data;
4783 struct in6_aliasreq *ifra = &_ifra;
4784 KASSERT(error == ENOTTY);
4785 strncpy(ifra->ifra_name, rumpuser_wg_get_tunname(wg->wg_user),
4786 IFNAMSIZ);
4787 error = rumpuser_wg_ioctl(wg->wg_user, cmd, ifra, AF_INET6);
4788 if (error == 0)
4789 error = ENOTTY;
4790 break;
4791 }
4792 #endif
4793 }
4794 #endif /* WG_RUMPKERNEL */
4795
4796 return error;
4797 }
4798
4799 static int
4800 wg_init(struct ifnet *ifp)
4801 {
4802
4803 ifp->if_flags |= IFF_RUNNING;
4804
4805 /* TODO flush pending packets. */
4806 return 0;
4807 }
4808
4809 #ifdef ALTQ
4810 static void
4811 wg_start(struct ifnet *ifp)
4812 {
4813 struct mbuf *m;
4814
4815 for (;;) {
4816 IFQ_DEQUEUE(&ifp->if_snd, m);
4817 if (m == NULL)
4818 break;
4819
4820 kpreempt_disable();
4821 const uint32_t h = curcpu()->ci_index; // pktq_rps_hash(m)
4822 if (__predict_false(!pktq_enqueue(wg_pktq, m, h))) {
4823 WGLOG(LOG_ERR, "%s: pktq full, dropping\n",
4824 if_name(ifp));
4825 m_freem(m);
4826 }
4827 kpreempt_enable();
4828 }
4829 }
4830 #endif
4831
4832 static void
4833 wg_stop(struct ifnet *ifp, int disable)
4834 {
4835
4836 KASSERT((ifp->if_flags & IFF_RUNNING) != 0);
4837 ifp->if_flags &= ~IFF_RUNNING;
4838
4839 /* Need to do something? */
4840 }
4841
4842 #ifdef WG_DEBUG_PARAMS
4843 SYSCTL_SETUP(sysctl_net_wg_setup, "sysctl net.wg setup")
4844 {
4845 const struct sysctlnode *node = NULL;
4846
4847 sysctl_createv(clog, 0, NULL, &node,
4848 CTLFLAG_PERMANENT,
4849 CTLTYPE_NODE, "wg",
4850 SYSCTL_DESCR("wg(4)"),
4851 NULL, 0, NULL, 0,
4852 CTL_NET, CTL_CREATE, CTL_EOL);
4853 sysctl_createv(clog, 0, &node, NULL,
4854 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
4855 CTLTYPE_QUAD, "rekey_after_messages",
4856 SYSCTL_DESCR("session liftime by messages"),
4857 NULL, 0, &wg_rekey_after_messages, 0, CTL_CREATE, CTL_EOL);
4858 sysctl_createv(clog, 0, &node, NULL,
4859 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
4860 CTLTYPE_INT, "rekey_after_time",
4861 SYSCTL_DESCR("session liftime"),
4862 NULL, 0, &wg_rekey_after_time, 0, CTL_CREATE, CTL_EOL);
4863 sysctl_createv(clog, 0, &node, NULL,
4864 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
4865 CTLTYPE_INT, "rekey_timeout",
4866 SYSCTL_DESCR("session handshake retry time"),
4867 NULL, 0, &wg_rekey_timeout, 0, CTL_CREATE, CTL_EOL);
4868 sysctl_createv(clog, 0, &node, NULL,
4869 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
4870 CTLTYPE_INT, "rekey_attempt_time",
4871 SYSCTL_DESCR("session handshake timeout"),
4872 NULL, 0, &wg_rekey_attempt_time, 0, CTL_CREATE, CTL_EOL);
4873 sysctl_createv(clog, 0, &node, NULL,
4874 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
4875 CTLTYPE_INT, "keepalive_timeout",
4876 SYSCTL_DESCR("keepalive timeout"),
4877 NULL, 0, &wg_keepalive_timeout, 0, CTL_CREATE, CTL_EOL);
4878 sysctl_createv(clog, 0, &node, NULL,
4879 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
4880 CTLTYPE_BOOL, "force_underload",
4881 SYSCTL_DESCR("force to detemine under load"),
4882 NULL, 0, &wg_force_underload, 0, CTL_CREATE, CTL_EOL);
4883 }
4884 #endif
4885
4886 #ifdef WG_RUMPKERNEL
4887 static bool
4888 wg_user_mode(struct wg_softc *wg)
4889 {
4890
4891 return wg->wg_user != NULL;
4892 }
4893
4894 static int
4895 wg_ioctl_linkstr(struct wg_softc *wg, struct ifdrv *ifd)
4896 {
4897 struct ifnet *ifp = &wg->wg_if;
4898 int error;
4899
4900 if (ifp->if_flags & IFF_UP)
4901 return EBUSY;
4902
4903 if (ifd->ifd_cmd == IFLINKSTR_UNSET) {
4904 /* XXX do nothing */
4905 return 0;
4906 } else if (ifd->ifd_cmd != 0) {
4907 return EINVAL;
4908 } else if (wg->wg_user != NULL) {
4909 return EBUSY;
4910 }
4911
4912 /* Assume \0 included */
4913 if (ifd->ifd_len > IFNAMSIZ) {
4914 return E2BIG;
4915 } else if (ifd->ifd_len < 1) {
4916 return EINVAL;
4917 }
4918
4919 char tun_name[IFNAMSIZ];
4920 error = copyinstr(ifd->ifd_data, tun_name, ifd->ifd_len, NULL);
4921 if (error != 0)
4922 return error;
4923
4924 if (strncmp(tun_name, "tun", 3) != 0)
4925 return EINVAL;
4926
4927 error = rumpuser_wg_create(tun_name, wg, &wg->wg_user);
4928
4929 return error;
4930 }
4931
4932 static int
4933 wg_send_user(struct wg_peer *wgp, struct mbuf *m)
4934 {
4935 int error;
4936 struct psref psref;
4937 struct wg_sockaddr *wgsa;
4938 struct wg_softc *wg = wgp->wgp_sc;
4939 struct iovec iov[1];
4940
4941 wgsa = wg_get_endpoint_sa(wgp, &psref);
4942
4943 iov[0].iov_base = mtod(m, void *);
4944 iov[0].iov_len = m->m_len;
4945
4946 /* Send messages to a peer via an ordinary socket. */
4947 error = rumpuser_wg_send_peer(wg->wg_user, wgsatosa(wgsa), iov, 1);
4948
4949 wg_put_sa(wgp, wgsa, &psref);
4950
4951 m_freem(m);
4952
4953 return error;
4954 }
4955
4956 static void
4957 wg_input_user(struct ifnet *ifp, struct mbuf *m, const int af)
4958 {
4959 struct wg_softc *wg = ifp->if_softc;
4960 struct iovec iov[2];
4961 struct sockaddr_storage ss;
4962
4963 KASSERT(af == AF_INET || af == AF_INET6);
4964
4965 WG_TRACE("");
4966
4967 if (af == AF_INET) {
4968 struct sockaddr_in *sin = (struct sockaddr_in *)&ss;
4969 struct ip *ip;
4970
4971 KASSERT(m->m_len >= sizeof(struct ip));
4972 ip = mtod(m, struct ip *);
4973 sockaddr_in_init(sin, &ip->ip_dst, 0);
4974 } else {
4975 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&ss;
4976 struct ip6_hdr *ip6;
4977
4978 KASSERT(m->m_len >= sizeof(struct ip6_hdr));
4979 ip6 = mtod(m, struct ip6_hdr *);
4980 sockaddr_in6_init(sin6, &ip6->ip6_dst, 0, 0, 0);
4981 }
4982
4983 iov[0].iov_base = &ss;
4984 iov[0].iov_len = ss.ss_len;
4985 iov[1].iov_base = mtod(m, void *);
4986 iov[1].iov_len = m->m_len;
4987
4988 WG_DUMP_BUF(iov[1].iov_base, iov[1].iov_len);
4989
4990 /* Send decrypted packets to users via a tun. */
4991 rumpuser_wg_send_user(wg->wg_user, iov, 2);
4992
4993 m_freem(m);
4994 }
4995
4996 static int
4997 wg_bind_port_user(struct wg_softc *wg, const uint16_t port)
4998 {
4999 int error;
5000 uint16_t old_port = wg->wg_listen_port;
5001
5002 if (port != 0 && old_port == port)
5003 return 0;
5004
5005 error = rumpuser_wg_sock_bind(wg->wg_user, port);
5006 if (error == 0)
5007 wg->wg_listen_port = port;
5008 return error;
5009 }
5010
5011 /*
5012 * Receive user packets.
5013 */
5014 void
5015 rumpkern_wg_recv_user(struct wg_softc *wg, struct iovec *iov, size_t iovlen)
5016 {
5017 struct ifnet *ifp = &wg->wg_if;
5018 struct mbuf *m;
5019 const struct sockaddr *dst;
5020
5021 WG_TRACE("");
5022
5023 dst = iov[0].iov_base;
5024
5025 m = m_gethdr(M_DONTWAIT, MT_DATA);
5026 if (m == NULL)
5027 return;
5028 m->m_len = m->m_pkthdr.len = 0;
5029 m_copyback(m, 0, iov[1].iov_len, iov[1].iov_base);
5030
5031 WG_DLOG("iov_len=%lu\n", iov[1].iov_len);
5032 WG_DUMP_BUF(iov[1].iov_base, iov[1].iov_len);
5033
5034 (void)wg_output(ifp, m, dst, NULL);
5035 }
5036
5037 /*
5038 * Receive packets from a peer.
5039 */
5040 void
5041 rumpkern_wg_recv_peer(struct wg_softc *wg, struct iovec *iov, size_t iovlen)
5042 {
5043 struct mbuf *m;
5044 const struct sockaddr *src;
5045 int bound;
5046
5047 WG_TRACE("");
5048
5049 src = iov[0].iov_base;
5050
5051 m = m_gethdr(M_DONTWAIT, MT_DATA);
5052 if (m == NULL)
5053 return;
5054 m->m_len = m->m_pkthdr.len = 0;
5055 m_copyback(m, 0, iov[1].iov_len, iov[1].iov_base);
5056
5057 WG_DLOG("iov_len=%lu\n", iov[1].iov_len);
5058 WG_DUMP_BUF(iov[1].iov_base, iov[1].iov_len);
5059
5060 bound = curlwp_bind();
5061 wg_handle_packet(wg, m, src);
5062 curlwp_bindx(bound);
5063 }
5064 #endif /* WG_RUMPKERNEL */
5065
5066 /*
5067 * Module infrastructure
5068 */
5069 #include "if_module.h"
5070
5071 IF_MODULE(MODULE_CLASS_DRIVER, wg, "sodium,blake2s")
5072