1/* $NetBSD: if.c,v 1.29 2021/03/23 18:16:53 christos Exp $ */ 2/* $KAME: if.c,v 1.36 2004/11/30 22:32:01 suz Exp $ */ 3 4/* 5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the project nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33#define RTM_NAMES 34#include <sys/param.h> 35#include <sys/queue.h> 36#include <sys/socket.h> 37#include <sys/sysctl.h> 38#include <sys/ioctl.h> 39#include <net/if.h> 40#include <net/if_types.h> 41#include <ifaddrs.h> 42#ifdef __FreeBSD__ 43#include <net/ethernet.h> 44#else 45#include <net/if_ether.h> 46#endif 47#include <net/route.h> 48#include <net/if_dl.h> 49#include <netinet/in.h> 50#include <netinet/icmp6.h> 51#include <unistd.h> 52#include <errno.h> 53#include <stdlib.h> 54#include <string.h> 55#include <syslog.h> 56 57#include "rtadvd.h" 58#include "if.h" 59#include "logit.h" 60#include "prog_ops.h" 61 62#ifndef RT_ROUNDUP 63#define RT_ROUNDUP(a) \ 64 ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long)) 65#define RT_ADVANCE(x, n) (x += RT_ROUNDUP((n)->sa_len)) 66#endif 67 68static void 69get_rtaddrs(int addrs, const struct sockaddr *sa, 70 const struct sockaddr **rti_info) 71{ 72 int i; 73 74 for (i = 0; i < RTAX_MAX; i++) { 75 if (addrs & (1 << i)) { 76 rti_info[i] = sa; 77 RT_ADVANCE(sa, sa); 78 } 79 else 80 rti_info[i] = NULL; 81 } 82} 83 84struct sockaddr_dl * 85if_nametosdl(const char *name) 86{ 87 struct ifaddrs *ifap, *ifa; 88 struct sockaddr_dl *sdl; 89 90 if (getifaddrs(&ifap) != 0) 91 return (NULL); 92 93 for (ifa = ifap; ifa; ifa = ifa->ifa_next) { 94 if (strcmp(ifa->ifa_name, name) != 0) 95 continue; 96 if (ifa->ifa_addr->sa_family != AF_LINK) 97 continue; 98 99 sdl = malloc(ifa->ifa_addr->sa_len); 100 if (!sdl) 101 continue; /*XXX*/ 102 103 memcpy(sdl, ifa->ifa_addr, ifa->ifa_addr->sa_len); 104 freeifaddrs(ifap); 105 return (sdl); 106 } 107 108 freeifaddrs(ifap); 109 return (NULL); 110} 111 112int 113if_getmtu(const char *name) 114{ 115 struct ifreq ifr; 116 int s, mtu; 117 118 if ((s = prog_socket(AF_INET6, SOCK_DGRAM, 0)) < 0) 119 return 0; 120 121 memset(&ifr, 0, sizeof(ifr)); 122 ifr.ifr_addr.sa_family = AF_INET6; 123 strncpy(ifr.ifr_name, name, sizeof(ifr.ifr_name)); 124 if (prog_ioctl(s, SIOCGIFMTU, &ifr) != -1) 125 mtu = ifr.ifr_mtu; 126 else 127 mtu = 0; 128 prog_close(s); 129 130 return mtu; 131} 132 133/* give interface index and its old flags, then new flags returned */ 134int 135if_getflags(unsigned int ifindex, int oifflags) 136{ 137 struct ifreq ifr; 138 int s; 139 140 if ((s = prog_socket(AF_INET6, SOCK_DGRAM, 0)) < 0) { 141 logit(LOG_ERR, "%s: socket: %m", __func__); 142 return (oifflags & ~IFF_UP); 143 } 144 145 memset(&ifr, 0, sizeof(ifr)); 146 if_indextoname(ifindex, ifr.ifr_name); 147 if (prog_ioctl(s, SIOCGIFFLAGS, &ifr) < 0) { 148 logit(LOG_ERR, "%s: ioctl:SIOCGIFFLAGS: failed for %s", 149 __func__, ifr.ifr_name); 150 prog_close(s); 151 return (oifflags & ~IFF_UP); 152 } 153 prog_close(s); 154 return (ifr.ifr_flags); 155} 156 157#define ROUNDUP8(a) (1 + (((a) - 1) | 7)) 158int 159lladdropt_length(struct sockaddr_dl *sdl) 160{ 161 switch (sdl->sdl_type) { 162 case IFT_ETHER: 163 case IFT_FDDI: 164 return(ROUNDUP8(ETHER_ADDR_LEN + 2)); 165 default: 166 return(0); 167 } 168} 169 170void 171lladdropt_fill(struct sockaddr_dl *sdl, struct nd_opt_hdr *ndopt) 172{ 173 char *addr; 174 175 ndopt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; /* fixed */ 176 177 switch (sdl->sdl_type) { 178 case IFT_ETHER: 179 case IFT_FDDI: 180 ndopt->nd_opt_len = (ROUNDUP8(ETHER_ADDR_LEN + 2)) >> 3; 181 addr = (char *)(ndopt + 1); 182 memcpy(addr, LLADDR(sdl), ETHER_ADDR_LEN); 183 break; 184 default: 185 logit(LOG_ERR, "%s: unsupported link type(%d)", 186 __func__, sdl->sdl_type); 187 exit(1); 188 } 189 190 return; 191} 192 193#define FILTER_MATCH(type, filter) ((0x1 << type) & filter) 194#define SIN6(s) ((const struct sockaddr_in6 *)(s)) 195#define SDL(s) ((const struct sockaddr_dl *)(s)) 196char * 197get_next_msg(char *buf, char *lim, unsigned int ifindex, size_t *lenp, 198 int filter) 199{ 200 struct rt_msghdr *rtm; 201 struct ifa_msghdr *ifam; 202 const struct sockaddr *sa, *dst, *gw, *ifa, *rti_info[RTAX_MAX]; 203 204 *lenp = 0; 205 for (rtm = (struct rt_msghdr *)buf; 206 rtm < (struct rt_msghdr *)lim; 207 rtm = (struct rt_msghdr *)(((char *)rtm) + rtm->rtm_msglen)) { 208 /* just for safety */ 209 if (!rtm->rtm_msglen) { 210 logit(LOG_WARNING, "%s: rtm_msglen is 0 " 211 "(buf=%p lim=%p rtm=%p)", __func__, 212 buf, lim, rtm); 213 break; 214 } 215 if (FILTER_MATCH(rtm->rtm_type, filter) == 0) { 216 continue; 217 } 218 219 switch (rtm->rtm_type) { 220 case RTM_GET: 221 case RTM_ADD: 222 case RTM_DELETE: 223 /* address related checks */ 224 sa = (struct sockaddr *)(rtm + 1); 225 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 226 if ((dst = rti_info[RTAX_DST]) == NULL || 227 dst->sa_family != AF_INET6) 228 continue; 229 230 if (IN6_IS_ADDR_LINKLOCAL(&SIN6(dst)->sin6_addr) || 231 IN6_IS_ADDR_MULTICAST(&SIN6(dst)->sin6_addr)) 232 continue; 233 234 if ((gw = rti_info[RTAX_GATEWAY]) == NULL || 235 gw->sa_family != AF_LINK) 236 continue; 237 if (ifindex && SDL(gw)->sdl_index != ifindex) 238 continue; 239 240 if (rti_info[RTAX_NETMASK] == NULL) 241 continue; 242 243 /* found */ 244 *lenp = rtm->rtm_msglen; 245 return (char *)rtm; 246 /* NOTREACHED */ 247 case RTM_NEWADDR: 248 case RTM_DELADDR: 249 ifam = (struct ifa_msghdr *)rtm; 250 251 /* address related checks */ 252 sa = (struct sockaddr *)(ifam + 1); 253 get_rtaddrs(ifam->ifam_addrs, sa, rti_info); 254 if ((ifa = rti_info[RTAX_IFA]) == NULL || 255 (ifa->sa_family != AF_INET && 256 ifa->sa_family != AF_INET6)) 257 continue; 258 259 if (ifa->sa_family == AF_INET6 && 260 (IN6_IS_ADDR_LINKLOCAL(&SIN6(ifa)->sin6_addr) || 261 IN6_IS_ADDR_MULTICAST(&SIN6(ifa)->sin6_addr))) 262 continue; 263 264 if (ifindex && ifam->ifam_index != ifindex) 265 continue; 266 267 /* found */ 268 *lenp = ifam->ifam_msglen; 269 return (char *)rtm; 270 /* NOTREACHED */ 271#ifdef RTM_IFANNOUNCE 272 case RTM_IFANNOUNCE: 273#endif 274 case RTM_IFINFO: 275 /* found */ 276 *lenp = rtm->rtm_msglen; 277 return (char *)rtm; 278 /* NOTREACHED */ 279 } 280 } 281 282 return (char *)rtm; 283} 284#undef FILTER_MATCH 285 286const struct in6_addr * 287get_addr(const void *buf) 288{ 289 const struct rt_msghdr *rtm = buf; 290 const struct sockaddr *sa, *rti_info[RTAX_MAX]; 291 292 sa = (const struct sockaddr *)(rtm + 1); 293 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 294 295 return &SIN6(rti_info[RTAX_DST])->sin6_addr; 296} 297 298unsigned int 299get_rtm_ifindex(const void *buf) 300{ 301 const struct rt_msghdr *rtm = buf; 302 const struct sockaddr *sa, *rti_info[RTAX_MAX]; 303 304 sa = (const struct sockaddr *)(rtm + 1); 305 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 306 307 return SDL(rti_info[RTAX_GATEWAY])->sdl_index; 308} 309 310unsigned int 311get_ifm_ifindex(const void *buf) 312{ 313 const struct if_msghdr *ifm = buf; 314 315 return ifm->ifm_index; 316} 317 318unsigned int 319get_ifam_ifindex(const void *buf) 320{ 321 const struct ifa_msghdr *ifam = buf; 322 323 return ifam->ifam_index; 324} 325 326int 327get_ifm_flags(const void *buf) 328{ 329 const struct if_msghdr *ifm = buf; 330 331 return ifm->ifm_flags; 332} 333 334#ifdef RTM_IFANNOUNCE 335unsigned int 336get_ifan_ifindex(const void *buf) 337{ 338 const struct if_announcemsghdr *ifan = buf; 339 340 return ifan->ifan_index; 341} 342 343int 344get_ifan_what(const void *buf) 345{ 346 const struct if_announcemsghdr *ifan = buf; 347 348 return (int)ifan->ifan_what; 349} 350#endif 351 352int 353get_prefixlen(const void *buf) 354{ 355 const struct rt_msghdr *rtm = buf; 356 const struct sockaddr *sa, *rti_info[RTAX_MAX]; 357 const unsigned char *p, *lim; 358 359 sa = (const struct sockaddr *)(rtm + 1); 360 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 361 sa = rti_info[RTAX_NETMASK]; 362 363 p = (const unsigned char *)(&SIN6(sa)->sin6_addr); 364 lim = (const unsigned char *)sa + sa->sa_len; 365 return prefixlen(p, lim); 366} 367 368int 369prefixlen(const unsigned char *p, const unsigned char *lim) 370{ 371 int masklen; 372 373 for (masklen = 0; p < lim; p++) { 374 switch (*p) { 375 case 0xff: 376 masklen += 8; 377 break; 378 case 0xfe: 379 masklen += 7; 380 break; 381 case 0xfc: 382 masklen += 6; 383 break; 384 case 0xf8: 385 masklen += 5; 386 break; 387 case 0xf0: 388 masklen += 4; 389 break; 390 case 0xe0: 391 masklen += 3; 392 break; 393 case 0xc0: 394 masklen += 2; 395 break; 396 case 0x80: 397 masklen += 1; 398 break; 399 case 0x00: 400 break; 401 default: 402 return -1; 403 } 404 } 405 406 return masklen; 407} 408 409int 410rtmsg_type(const void *buf) 411{ 412 const struct rt_msghdr *rtm = buf; 413 414 return rtm->rtm_type; 415} 416 417const char * 418rtmsg_typestr(const void *buf) 419{ 420 const struct rt_msghdr *rtm = buf; 421 422 return rtm->rtm_type < __arraycount(rtm_names) 423 ? rtm_names[rtm->rtm_type] : "*unknown*"; 424} 425 426int 427rtmsg_len(const void *buf) 428{ 429 const struct rt_msghdr *rtm = buf; 430 431 return rtm->rtm_msglen; 432} 433