if_virt.c revision 1.21
1 /* $NetBSD: if_virt.c,v 1.21 2010/11/15 20:23:11 pooka Exp $ */ 2 3 /* 4 * Copyright (c) 2008 Antti Kantee. All Rights Reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS 16 * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 18 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __KERNEL_RCSID(0, "$NetBSD: if_virt.c,v 1.21 2010/11/15 20:23:11 pooka Exp $"); 30 31 #include <sys/param.h> 32 #include <sys/condvar.h> 33 #include <sys/fcntl.h> 34 #include <sys/kernel.h> 35 #include <sys/kmem.h> 36 #include <sys/kthread.h> 37 #include <sys/mutex.h> 38 #include <sys/poll.h> 39 #include <sys/sockio.h> 40 #include <sys/socketvar.h> 41 42 #include <net/bpf.h> 43 #include <net/if.h> 44 #include <net/if_ether.h> 45 #include <net/if_tap.h> 46 47 #include <netinet/in.h> 48 #include <netinet/in_var.h> 49 50 #include <rump/rump.h> 51 #include <rump/rumpuser.h> 52 53 #include "rump_private.h" 54 #include "rump_net_private.h" 55 56 /* 57 * Virtual interface for userspace purposes. Uses tap(4) to 58 * interface with the kernel and just simply shovels data 59 * to/from /dev/tap. 60 */ 61 62 #define VIRTIF_BASE "virt" 63 64 static int virtif_init(struct ifnet *); 65 static int virtif_ioctl(struct ifnet *, u_long, void *); 66 static void virtif_start(struct ifnet *); 67 static void virtif_stop(struct ifnet *, int); 68 69 struct virtif_sc { 70 struct ethercom sc_ec; 71 int sc_tapfd; 72 bool sc_dying; 73 struct lwp *sc_l_snd, *sc_l_rcv; 74 kmutex_t sc_mtx; 75 kcondvar_t sc_cv; 76 }; 77 78 static void virtif_receiver(void *); 79 static void virtif_sender(void *); 80 static int virtif_clone(struct if_clone *, int); 81 static int virtif_unclone(struct ifnet *); 82 83 struct if_clone virtif_cloner = 84 IF_CLONE_INITIALIZER(VIRTIF_BASE, virtif_clone, virtif_unclone); 85 86 int 87 rump_virtif_create(int num) 88 { 89 struct virtif_sc *sc; 90 struct ifnet *ifp; 91 uint8_t enaddr[ETHER_ADDR_LEN] = { 0xb2, 0x0a, 0x00, 0x0b, 0x0e, 0x01 }; 92 char tapdev[16]; 93 int fd, error = 0; 94 95 if (num >= 0x100) 96 return E2BIG; 97 98 snprintf(tapdev, sizeof(tapdev), "/dev/tap%d", num); 99 fd = rumpuser_open(tapdev, O_RDWR, &error); 100 if (fd == -1) { 101 printf("virtif_create: can't open /dev/tap%d: %d\n", 102 num, error); 103 return error; 104 } 105 enaddr[2] = arc4random() & 0xff; 106 enaddr[5] = num; 107 108 sc = kmem_zalloc(sizeof(*sc), KM_SLEEP); 109 sc->sc_dying = false; 110 sc->sc_tapfd = fd; 111 112 mutex_init(&sc->sc_mtx, MUTEX_DEFAULT, IPL_NONE); 113 cv_init(&sc->sc_cv, "virtsnd"); 114 ifp = &sc->sc_ec.ec_if; 115 sprintf(ifp->if_xname, "%s%d", VIRTIF_BASE, num); 116 ifp->if_softc = sc; 117 118 if (rump_threads) { 119 if ((error = kthread_create(PRI_NONE, KTHREAD_JOINABLE, NULL, 120 virtif_receiver, ifp, &sc->sc_l_rcv, "virtifr")) != 0) 121 goto out; 122 123 if ((error = kthread_create(PRI_NONE, 124 KTHREAD_JOINABLE | KTHREAD_MPSAFE, NULL, 125 virtif_sender, ifp, &sc->sc_l_snd, "virtifs")) != 0) 126 goto out; 127 } else { 128 printf("WARNING: threads not enabled, receive NOT working\n"); 129 } 130 131 ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST; 132 ifp->if_init = virtif_init; 133 ifp->if_ioctl = virtif_ioctl; 134 ifp->if_start = virtif_start; 135 ifp->if_stop = virtif_stop; 136 IFQ_SET_READY(&ifp->if_snd); 137 138 if_attach(ifp); 139 ether_ifattach(ifp, enaddr); 140 141 out: 142 if (error) { 143 virtif_unclone(ifp); 144 } 145 146 return error; 147 } 148 149 static int 150 virtif_clone(struct if_clone *ifc, int unit) 151 { 152 153 return rump_virtif_create(unit); 154 } 155 156 static int 157 virtif_unclone(struct ifnet *ifp) 158 { 159 struct virtif_sc *sc = ifp->if_softc; 160 161 mutex_enter(&sc->sc_mtx); 162 if (sc->sc_dying) { 163 mutex_exit(&sc->sc_mtx); 164 return EINPROGRESS; 165 } 166 sc->sc_dying = true; 167 cv_broadcast(&sc->sc_cv); 168 mutex_exit(&sc->sc_mtx); 169 170 virtif_stop(ifp, 1); 171 if_down(ifp); 172 173 if (sc->sc_l_snd) { 174 kthread_join(sc->sc_l_snd); 175 sc->sc_l_snd = NULL; 176 } 177 if (sc->sc_l_rcv) { 178 kthread_join(sc->sc_l_rcv); 179 sc->sc_l_rcv = NULL; 180 } 181 182 rumpuser_close(sc->sc_tapfd, NULL); 183 184 mutex_destroy(&sc->sc_mtx); 185 cv_destroy(&sc->sc_cv); 186 kmem_free(sc, sizeof(*sc)); 187 188 ether_ifdetach(ifp); 189 if_detach(ifp); 190 191 return 0; 192 } 193 194 static int 195 virtif_init(struct ifnet *ifp) 196 { 197 struct virtif_sc *sc = ifp->if_softc; 198 199 ifp->if_flags |= IFF_RUNNING; 200 201 mutex_enter(&sc->sc_mtx); 202 cv_broadcast(&sc->sc_cv); 203 mutex_exit(&sc->sc_mtx); 204 205 return 0; 206 } 207 208 static int 209 virtif_ioctl(struct ifnet *ifp, u_long cmd, void *data) 210 { 211 int s, rv; 212 213 s = splnet(); 214 rv = ether_ioctl(ifp, cmd, data); 215 if (rv == ENETRESET) 216 rv = 0; 217 splx(s); 218 219 return rv; 220 } 221 222 /* just send everything in-context */ 223 static void 224 virtif_start(struct ifnet *ifp) 225 { 226 struct virtif_sc *sc = ifp->if_softc; 227 228 mutex_enter(&sc->sc_mtx); 229 ifp->if_flags |= IFF_OACTIVE; 230 cv_broadcast(&sc->sc_cv); 231 mutex_exit(&sc->sc_mtx); 232 } 233 234 static void 235 virtif_stop(struct ifnet *ifp, int disable) 236 { 237 struct virtif_sc *sc = ifp->if_softc; 238 239 ifp->if_flags &= ~IFF_RUNNING; 240 241 mutex_enter(&sc->sc_mtx); 242 cv_broadcast(&sc->sc_cv); 243 mutex_exit(&sc->sc_mtx); 244 } 245 246 #define POLLTIMO_MS 1 247 static void 248 virtif_receiver(void *arg) 249 { 250 struct ifnet *ifp = arg; 251 struct virtif_sc *sc = ifp->if_softc; 252 struct mbuf *m; 253 size_t plen = ETHER_MAX_LEN_JUMBO+1; 254 struct pollfd pfd; 255 ssize_t n; 256 int error, rv; 257 258 pfd.fd = sc->sc_tapfd; 259 pfd.events = POLLIN; 260 261 KASSERT(rump_kernel_isbiglocked()); 262 263 for (;;) { 264 m = m_gethdr(M_WAIT, MT_DATA); 265 MEXTMALLOC(m, plen, M_WAIT); 266 267 again: 268 /* poll, but periodically check if we should die */ 269 rv = rumpuser_poll(&pfd, 1, POLLTIMO_MS, &error); 270 if (sc->sc_dying) { 271 m_freem(m); 272 break; 273 } 274 if (rv == 0) 275 goto again; 276 277 n = rumpuser_read(sc->sc_tapfd, mtod(m, void *), plen, &error); 278 KASSERT(n < ETHER_MAX_LEN_JUMBO); 279 if (__predict_false(n < 0)) { 280 if (n == -1 && error == EAGAIN) { 281 goto again; 282 } 283 284 printf("%s: read from /dev/tap failed. host if down?\n", 285 ifp->if_xname); 286 mutex_enter(&sc->sc_mtx); 287 /* could check if need go, done soon anyway */ 288 cv_timedwait(&sc->sc_cv, &sc->sc_mtx, hz); 289 mutex_exit(&sc->sc_mtx); 290 goto again; 291 } 292 293 /* tap sometimes returns EOF. don't sweat it and plow on */ 294 if (__predict_false(n == 0)) 295 goto again; 296 297 /* discard if we're not up */ 298 if ((ifp->if_flags & IFF_RUNNING) == 0) 299 goto again; 300 301 m->m_len = m->m_pkthdr.len = n; 302 m->m_pkthdr.rcvif = ifp; 303 bpf_mtap(ifp, m); 304 ether_input(ifp, m); 305 } 306 307 kthread_exit(0); 308 } 309 310 /* lazy bum stetson-harrison magic value */ 311 #define LB_SH 32 312 static void 313 virtif_sender(void *arg) 314 { 315 struct ifnet *ifp = arg; 316 struct virtif_sc *sc = ifp->if_softc; 317 struct mbuf *m, *m0; 318 struct rumpuser_iovec io[LB_SH]; 319 int i, error; 320 321 mutex_enter(&sc->sc_mtx); 322 KERNEL_LOCK(1, NULL); 323 while (!sc->sc_dying) { 324 if (!ifp->if_flags & IFF_RUNNING) { 325 cv_wait(&sc->sc_cv, &sc->sc_mtx); 326 continue; 327 } 328 IF_DEQUEUE(&ifp->if_snd, m0); 329 if (!m0) { 330 ifp->if_flags &= ~IFF_OACTIVE; 331 cv_wait(&sc->sc_cv, &sc->sc_mtx); 332 continue; 333 } 334 mutex_exit(&sc->sc_mtx); 335 336 m = m0; 337 for (i = 0; i < LB_SH && m; i++) { 338 io[i].iov_base = mtod(m, void *); 339 io[i].iov_len = m->m_len; 340 m = m->m_next; 341 } 342 if (i == LB_SH) 343 panic("lazy bum"); 344 bpf_mtap(ifp, m0); 345 KERNEL_UNLOCK_LAST(curlwp); 346 347 rumpuser_writev(sc->sc_tapfd, io, i, &error); 348 349 KERNEL_LOCK(1, NULL); 350 m_freem(m0); 351 mutex_enter(&sc->sc_mtx); 352 } 353 KERNEL_UNLOCK_LAST(curlwp); 354 355 mutex_exit(&sc->sc_mtx); 356 357 kthread_exit(0); 358 } 359 360 /* 361 * dummyif is a nada-interface. 362 * As it requires nothing external, it can be used for testing 363 * interface configuration. 364 */ 365 static int dummyif_init(struct ifnet *); 366 static void dummyif_start(struct ifnet *); 367 368 void 369 rump_dummyif_create() 370 { 371 struct ifnet *ifp; 372 struct ethercom *ec; 373 uint8_t enaddr[ETHER_ADDR_LEN] = { 0xb2, 0x0a, 0x00, 0x0b, 0x0e, 0x01 }; 374 375 enaddr[2] = arc4random() & 0xff; 376 enaddr[5] = arc4random() & 0xff; 377 378 ec = kmem_zalloc(sizeof(*ec), KM_SLEEP); 379 380 ifp = &ec->ec_if; 381 strlcpy(ifp->if_xname, "dummy0", sizeof(ifp->if_xname)); 382 ifp->if_softc = ifp; 383 ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST; 384 ifp->if_init = dummyif_init; 385 ifp->if_ioctl = virtif_ioctl; 386 ifp->if_start = dummyif_start; 387 388 if_attach(ifp); 389 ether_ifattach(ifp, enaddr); 390 } 391 392 static int 393 dummyif_init(struct ifnet *ifp) 394 { 395 396 ifp->if_flags |= IFF_RUNNING; 397 return 0; 398 } 399 400 static void 401 dummyif_start(struct ifnet *ifp) 402 { 403 404 } 405
Indexes created Thu Sep 25 08:09:54 GMT 2025