1 /* $NetBSD: net.c,v 1.5 2026/04/08 00:16:15 christos Exp $ */ 2 3 /* 4 * Copyright (C) Internet Systems Consortium, Inc. ("ISC") 5 * 6 * SPDX-License-Identifier: MPL-2.0 7 * 8 * This Source Code Form is subject to the terms of the Mozilla Public 9 * License, v. 2.0. If a copy of the MPL was not distributed with this 10 * file, you can obtain one at https://mozilla.org/MPL/2.0/. 11 * 12 * See the COPYRIGHT file distributed with this work for additional 13 * information regarding copyright ownership. 14 */ 15 16 #include <stdbool.h> 17 #include <sys/types.h> 18 19 #if defined(HAVE_SYS_SYSCTL_H) && !defined(__linux__) 20 #if defined(HAVE_SYS_PARAM_H) 21 #include <sys/param.h> 22 #endif /* if defined(HAVE_SYS_PARAM_H) */ 23 #include <sys/sysctl.h> 24 #endif /* if defined(HAVE_SYS_SYSCTL_H) && !defined(__linux__) */ 25 #include <errno.h> 26 #include <fcntl.h> 27 #include <netdb.h> 28 #include <sys/uio.h> 29 #include <unistd.h> 30 31 #include <isc/log.h> 32 #include <isc/net.h> 33 #include <isc/once.h> 34 #include <isc/strerr.h> 35 #include <isc/string.h> 36 #include <isc/util.h> 37 38 #ifndef socklen_t 39 #define socklen_t unsigned int 40 #endif /* ifndef socklen_t */ 41 42 /*% 43 * Definitions about UDP port range specification. This is a total mess of 44 * portability variants: some use sysctl (but the sysctl names vary), some use 45 * system-specific interfaces, some have the same interface for IPv4 and IPv6, 46 * some separate them, etc... 47 */ 48 49 /*% 50 * The last resort defaults: use all non well known port space 51 */ 52 #ifndef ISC_NET_PORTRANGELOW 53 #define ISC_NET_PORTRANGELOW 1024 54 #endif /* ISC_NET_PORTRANGELOW */ 55 #ifndef ISC_NET_PORTRANGEHIGH 56 #define ISC_NET_PORTRANGEHIGH 65535 57 #endif /* ISC_NET_PORTRANGEHIGH */ 58 59 #ifdef HAVE_SYSCTLBYNAME 60 61 /*% 62 * sysctl variants 63 */ 64 #if defined(__FreeBSD__) || defined(__APPLE__) || defined(__DragonFly__) 65 #define USE_SYSCTL_PORTRANGE 66 #define SYSCTL_V4PORTRANGE_LOW "net.inet.ip.portrange.hifirst" 67 #define SYSCTL_V4PORTRANGE_HIGH "net.inet.ip.portrange.hilast" 68 #define SYSCTL_V6PORTRANGE_LOW "net.inet.ip.portrange.hifirst" 69 #define SYSCTL_V6PORTRANGE_HIGH "net.inet.ip.portrange.hilast" 70 #endif /* if defined(__FreeBSD__) || defined(__APPLE__) || \ 71 * defined(__DragonFly__) */ 72 73 #ifdef __NetBSD__ 74 #define USE_SYSCTL_PORTRANGE 75 #define SYSCTL_V4PORTRANGE_LOW "net.inet.ip.anonportmin" 76 #define SYSCTL_V4PORTRANGE_HIGH "net.inet.ip.anonportmax" 77 #define SYSCTL_V6PORTRANGE_LOW "net.inet6.ip6.anonportmin" 78 #define SYSCTL_V6PORTRANGE_HIGH "net.inet6.ip6.anonportmax" 79 #endif /* ifdef __NetBSD__ */ 80 81 #else /* !HAVE_SYSCTLBYNAME */ 82 83 #ifdef __OpenBSD__ 84 #define USE_SYSCTL_PORTRANGE 85 #define SYSCTL_V4PORTRANGE_LOW \ 86 { CTL_NET, PF_INET, IPPROTO_IP, IPCTL_IPPORT_HIFIRSTAUTO } 87 #define SYSCTL_V4PORTRANGE_HIGH \ 88 { CTL_NET, PF_INET, IPPROTO_IP, IPCTL_IPPORT_HILASTAUTO } 89 /* Same for IPv6 */ 90 #define SYSCTL_V6PORTRANGE_LOW SYSCTL_V4PORTRANGE_LOW 91 #define SYSCTL_V6PORTRANGE_HIGH SYSCTL_V4PORTRANGE_HIGH 92 #endif /* ifdef __OpenBSD__ */ 93 94 #endif /* HAVE_SYSCTLBYNAME */ 95 96 static isc_once_t once_ipv6only = ISC_ONCE_INIT; 97 #ifdef __notyet__ 98 static isc_once_t once_ipv6pktinfo = ISC_ONCE_INIT; 99 #endif /* ifdef __notyet__ */ 100 101 #ifndef ISC_CMSG_IP_TOS 102 #ifdef __APPLE__ 103 #define ISC_CMSG_IP_TOS 0 /* As of 10.8.2. */ 104 #else /* ! __APPLE__ */ 105 #define ISC_CMSG_IP_TOS 1 106 #endif /* ! __APPLE__ */ 107 #endif /* ! ISC_CMSG_IP_TOS */ 108 109 static isc_once_t once = ISC_ONCE_INIT; 110 111 static isc_result_t ipv4_result = ISC_R_NOTFOUND; 112 static isc_result_t ipv6_result = ISC_R_NOTFOUND; 113 static isc_result_t ipv6only_result = ISC_R_NOTFOUND; 114 static isc_result_t ipv6pktinfo_result = ISC_R_NOTFOUND; 115 116 static isc_result_t 117 try_proto(int domain) { 118 int s; 119 isc_result_t result = ISC_R_SUCCESS; 120 121 s = socket(domain, SOCK_STREAM, 0); 122 if (s == -1) { 123 switch (errno) { 124 #ifdef EAFNOSUPPORT 125 case EAFNOSUPPORT: 126 #endif /* ifdef EAFNOSUPPORT */ 127 #ifdef EPFNOSUPPORT 128 case EPFNOSUPPORT: 129 #endif /* ifdef EPFNOSUPPORT */ 130 #ifdef EPROTONOSUPPORT 131 case EPROTONOSUPPORT: 132 #endif /* ifdef EPROTONOSUPPORT */ 133 #ifdef EINVAL 134 case EINVAL: 135 #endif /* ifdef EINVAL */ 136 return ISC_R_NOTFOUND; 137 default: 138 UNEXPECTED_SYSERROR(errno, "socket()"); 139 return ISC_R_UNEXPECTED; 140 } 141 } 142 143 if (domain == PF_INET6) { 144 struct sockaddr_in6 sin6; 145 unsigned int len; 146 147 /* 148 * Check to see if IPv6 is broken, as is common on Linux. 149 */ 150 len = sizeof(sin6); 151 if (getsockname(s, (struct sockaddr *)&sin6, (void *)&len) < 0) 152 { 153 isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL, 154 ISC_LOGMODULE_SOCKET, ISC_LOG_ERROR, 155 "retrieving the address of an IPv6 " 156 "socket from the kernel failed."); 157 isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL, 158 ISC_LOGMODULE_SOCKET, ISC_LOG_ERROR, 159 "IPv6 is not supported."); 160 result = ISC_R_NOTFOUND; 161 } else { 162 if (len == sizeof(struct sockaddr_in6)) { 163 result = ISC_R_SUCCESS; 164 } else { 165 isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL, 166 ISC_LOGMODULE_SOCKET, 167 ISC_LOG_ERROR, 168 "IPv6 structures in kernel and " 169 "user space do not match."); 170 isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL, 171 ISC_LOGMODULE_SOCKET, 172 ISC_LOG_ERROR, 173 "IPv6 is not supported."); 174 result = ISC_R_NOTFOUND; 175 } 176 } 177 } 178 179 (void)close(s); 180 181 return result; 182 } 183 184 static void 185 initialize_action(void) { 186 ipv4_result = try_proto(PF_INET); 187 ipv6_result = try_proto(PF_INET6); 188 } 189 190 static void 191 initialize(void) { 192 isc_once_do(&once, initialize_action); 193 } 194 195 isc_result_t 196 isc_net_probeipv4(void) { 197 initialize(); 198 return ipv4_result; 199 } 200 201 isc_result_t 202 isc_net_probeipv6(void) { 203 initialize(); 204 return ipv6_result; 205 } 206 207 static void 208 try_ipv6only(void) { 209 #ifdef IPV6_V6ONLY 210 int s, on; 211 #endif /* ifdef IPV6_V6ONLY */ 212 isc_result_t result; 213 214 result = isc_net_probeipv6(); 215 if (result != ISC_R_SUCCESS) { 216 ipv6only_result = result; 217 return; 218 } 219 220 #ifndef IPV6_V6ONLY 221 ipv6only_result = ISC_R_NOTFOUND; 222 return; 223 #else /* ifndef IPV6_V6ONLY */ 224 /* check for TCP sockets */ 225 s = socket(PF_INET6, SOCK_STREAM, 0); 226 if (s == -1) { 227 UNEXPECTED_SYSERROR(errno, "socket()"); 228 ipv6only_result = ISC_R_UNEXPECTED; 229 return; 230 } 231 232 on = 1; 233 if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) < 0) { 234 ipv6only_result = ISC_R_NOTFOUND; 235 goto close; 236 } 237 238 close(s); 239 240 /* check for UDP sockets */ 241 s = socket(PF_INET6, SOCK_DGRAM, 0); 242 if (s == -1) { 243 UNEXPECTED_SYSERROR(errno, "socket()"); 244 ipv6only_result = ISC_R_UNEXPECTED; 245 return; 246 } 247 248 on = 1; 249 if (setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on)) < 0) { 250 ipv6only_result = ISC_R_NOTFOUND; 251 goto close; 252 } 253 254 ipv6only_result = ISC_R_SUCCESS; 255 256 close: 257 close(s); 258 return; 259 #endif /* IPV6_V6ONLY */ 260 } 261 262 static void 263 initialize_ipv6only(void) { 264 isc_once_do(&once_ipv6only, try_ipv6only); 265 } 266 267 #ifdef __notyet__ 268 static void 269 try_ipv6pktinfo(void) { 270 int s, on; 271 isc_result_t result; 272 int optname; 273 274 result = isc_net_probeipv6(); 275 if (result != ISC_R_SUCCESS) { 276 ipv6pktinfo_result = result; 277 return; 278 } 279 280 /* we only use this for UDP sockets */ 281 s = socket(PF_INET6, SOCK_DGRAM, IPPROTO_UDP); 282 if (s == -1) { 283 UNEXPECTED_SYSERROR(errno, "socket()"); 284 ipv6pktinfo_result = ISC_R_UNEXPECTED; 285 return; 286 } 287 288 #ifdef IPV6_RECVPKTINFO 289 optname = IPV6_RECVPKTINFO; 290 #else /* ifdef IPV6_RECVPKTINFO */ 291 optname = IPV6_PKTINFO; 292 #endif /* ifdef IPV6_RECVPKTINFO */ 293 on = 1; 294 if (setsockopt(s, IPPROTO_IPV6, optname, &on, sizeof(on)) < 0) { 295 ipv6pktinfo_result = ISC_R_NOTFOUND; 296 goto close; 297 } 298 299 ipv6pktinfo_result = ISC_R_SUCCESS; 300 301 close: 302 close(s); 303 return; 304 } 305 306 static void 307 initialize_ipv6pktinfo(void) { 308 isc_once_do(&once_ipv6pktinfo, try_ipv6pktinfo); 309 } 310 #endif /* ifdef __notyet__ */ 311 312 isc_result_t 313 isc_net_probe_ipv6only(void) { 314 initialize_ipv6only(); 315 return ipv6only_result; 316 } 317 318 isc_result_t 319 isc_net_probe_ipv6pktinfo(void) { 320 /* 321 * XXXWPK if pktinfo were supported then we could listen on :: for ipv6 and get 322 * the information about the destination address from pktinfo structure passed 323 * in recvmsg but this method is not portable and libuv doesn't support it - so 324 * we need to listen on all interfaces. 325 * We should verify that this doesn't impact performance (we already do it for 326 * ipv4) and either remove all the ipv6pktinfo detection code from above 327 * or think of fixing libuv. 328 */ 329 #ifdef __notyet__ 330 initialize_ipv6pktinfo(); 331 #endif /* ifdef __notyet__ */ 332 return ipv6pktinfo_result; 333 } 334 335 #if defined(USE_SYSCTL_PORTRANGE) 336 #if defined(HAVE_SYSCTLBYNAME) 337 static isc_result_t 338 getportrange_sysctl(int af, in_port_t *low, in_port_t *high) { 339 int port_low, port_high; 340 size_t portlen; 341 const char *sysctlname_lowport, *sysctlname_hiport; 342 343 if (af == AF_INET) { 344 sysctlname_lowport = SYSCTL_V4PORTRANGE_LOW; 345 sysctlname_hiport = SYSCTL_V4PORTRANGE_HIGH; 346 } else { 347 sysctlname_lowport = SYSCTL_V6PORTRANGE_LOW; 348 sysctlname_hiport = SYSCTL_V6PORTRANGE_HIGH; 349 } 350 portlen = sizeof(port_low); 351 if (sysctlbyname(sysctlname_lowport, &port_low, &portlen, NULL, 0) < 0) 352 { 353 return ISC_R_FAILURE; 354 } 355 portlen = sizeof(port_high); 356 if (sysctlbyname(sysctlname_hiport, &port_high, &portlen, NULL, 0) < 0) 357 { 358 return ISC_R_FAILURE; 359 } 360 if ((port_low & ~0xffff) != 0 || (port_high & ~0xffff) != 0) { 361 return ISC_R_RANGE; 362 } 363 364 *low = (in_port_t)port_low; 365 *high = (in_port_t)port_high; 366 367 return ISC_R_SUCCESS; 368 } 369 #else /* !HAVE_SYSCTLBYNAME */ 370 static isc_result_t 371 getportrange_sysctl(int af, in_port_t *low, in_port_t *high) { 372 int mib_lo4[4] = SYSCTL_V4PORTRANGE_LOW; 373 int mib_hi4[4] = SYSCTL_V4PORTRANGE_HIGH; 374 int mib_lo6[4] = SYSCTL_V6PORTRANGE_LOW; 375 int mib_hi6[4] = SYSCTL_V6PORTRANGE_HIGH; 376 int *mib_lo, *mib_hi, miblen; 377 int port_low, port_high; 378 size_t portlen; 379 380 if (af == AF_INET) { 381 mib_lo = mib_lo4; 382 mib_hi = mib_hi4; 383 miblen = sizeof(mib_lo4) / sizeof(mib_lo4[0]); 384 } else { 385 mib_lo = mib_lo6; 386 mib_hi = mib_hi6; 387 miblen = sizeof(mib_lo6) / sizeof(mib_lo6[0]); 388 } 389 390 portlen = sizeof(port_low); 391 if (sysctl(mib_lo, miblen, &port_low, &portlen, NULL, 0) < 0) { 392 return ISC_R_FAILURE; 393 } 394 395 portlen = sizeof(port_high); 396 if (sysctl(mib_hi, miblen, &port_high, &portlen, NULL, 0) < 0) { 397 return ISC_R_FAILURE; 398 } 399 400 if ((port_low & ~0xffff) != 0 || (port_high & ~0xffff) != 0) { 401 return ISC_R_RANGE; 402 } 403 404 *low = (in_port_t)port_low; 405 *high = (in_port_t)port_high; 406 407 return ISC_R_SUCCESS; 408 } 409 #endif /* HAVE_SYSCTLBYNAME */ 410 #endif /* USE_SYSCTL_PORTRANGE */ 411 412 void 413 isc_net_getportrange(int af, in_port_t *low, in_port_t *high) { 414 int result = ISC_R_FAILURE; 415 #if !defined(USE_SYSCTL_PORTRANGE) && defined(__linux__) 416 FILE *fp; 417 #endif /* if !defined(USE_SYSCTL_PORTRANGE) && defined(__linux__) */ 418 419 REQUIRE(low != NULL && high != NULL); 420 421 #if defined(USE_SYSCTL_PORTRANGE) 422 result = getportrange_sysctl(af, low, high); 423 #elif defined(__linux__) 424 425 UNUSED(af); 426 427 /* 428 * Linux local ports are address family agnostic. 429 */ 430 fp = fopen("/proc/sys/net/ipv4/ip_local_port_range", "r"); 431 if (fp != NULL) { 432 int n; 433 unsigned int l, h; 434 435 n = fscanf(fp, "%u %u", &l, &h); 436 if (n == 2 && (l & ~0xffff) == 0 && (h & ~0xffff) == 0) { 437 *low = l; 438 *high = h; 439 result = ISC_R_SUCCESS; 440 } 441 fclose(fp); 442 } 443 #else /* if defined(USE_SYSCTL_PORTRANGE) */ 444 UNUSED(af); 445 #endif /* if defined(USE_SYSCTL_PORTRANGE) */ 446 447 if (result != ISC_R_SUCCESS) { 448 *low = ISC_NET_PORTRANGELOW; 449 *high = ISC_NET_PORTRANGEHIGH; 450 } 451 } 452 453 void 454 isc_net_disableipv4(void) { 455 initialize(); 456 if (ipv4_result == ISC_R_SUCCESS) { 457 ipv4_result = ISC_R_DISABLED; 458 } 459 } 460 461 void 462 isc_net_disableipv6(void) { 463 initialize(); 464 if (ipv6_result == ISC_R_SUCCESS) { 465 ipv6_result = ISC_R_DISABLED; 466 } 467 } 468 469 void 470 isc_net_enableipv4(void) { 471 initialize(); 472 if (ipv4_result == ISC_R_DISABLED) { 473 ipv4_result = ISC_R_SUCCESS; 474 } 475 } 476 477 void 478 isc_net_enableipv6(void) { 479 initialize(); 480 if (ipv6_result == ISC_R_DISABLED) { 481 ipv6_result = ISC_R_SUCCESS; 482 } 483 } 484
Indexes created Fri Aug 14 00:25:39 UTC 2026