1 /* $NetBSD: if.c,v 1.26 2018/04/20 10:39:37 roy 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 #include <sys/param.h> 34 #include <sys/queue.h> 35 #include <sys/socket.h> 36 #include <sys/sysctl.h> 37 #include <sys/ioctl.h> 38 #include <net/if.h> 39 #include <net/if_types.h> 40 #include <ifaddrs.h> 41 #ifdef __FreeBSD__ 42 #include <net/ethernet.h> 43 #else 44 #include <net/if_ether.h> 45 #endif 46 #include <net/route.h> 47 #include <net/if_dl.h> 48 #include <netinet/in.h> 49 #include <netinet/icmp6.h> 50 #include <unistd.h> 51 #include <errno.h> 52 #include <stdlib.h> 53 #include <string.h> 54 #include <syslog.h> 55 56 #include "rtadvd.h" 57 #include "if.h" 58 #include "logit.h" 59 #include "prog_ops.h" 60 61 #ifndef RT_ROUNDUP 62 #define RT_ROUNDUP(a) \ 63 ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long)) 64 #define RT_ADVANCE(x, n) (x += RT_ROUNDUP((n)->sa_len)) 65 #endif 66 67 static void 68 get_rtaddrs(int addrs, struct sockaddr *sa, struct sockaddr **rti_info) 69 { 70 int i; 71 72 for (i = 0; i < RTAX_MAX; i++) { 73 if (addrs & (1 << i)) { 74 rti_info[i] = sa; 75 RT_ADVANCE(sa, sa); 76 } 77 else 78 rti_info[i] = NULL; 79 } 80 } 81 82 struct sockaddr_dl * 83 if_nametosdl(const char *name) 84 { 85 struct ifaddrs *ifap, *ifa; 86 struct sockaddr_dl *sdl; 87 88 if (getifaddrs(&ifap) != 0) 89 return (NULL); 90 91 for (ifa = ifap; ifa; ifa = ifa->ifa_next) { 92 if (strcmp(ifa->ifa_name, name) != 0) 93 continue; 94 if (ifa->ifa_addr->sa_family != AF_LINK) 95 continue; 96 97 sdl = malloc(ifa->ifa_addr->sa_len); 98 if (!sdl) 99 continue; /*XXX*/ 100 101 memcpy(sdl, ifa->ifa_addr, ifa->ifa_addr->sa_len); 102 freeifaddrs(ifap); 103 return (sdl); 104 } 105 106 freeifaddrs(ifap); 107 return (NULL); 108 } 109 110 int 111 if_getmtu(const char *name) 112 { 113 struct ifreq ifr; 114 int s, mtu; 115 116 if ((s = prog_socket(AF_INET6, SOCK_DGRAM, 0)) < 0) 117 return 0; 118 119 memset(&ifr, 0, sizeof(ifr)); 120 ifr.ifr_addr.sa_family = AF_INET6; 121 strncpy(ifr.ifr_name, name, sizeof(ifr.ifr_name)); 122 if (prog_ioctl(s, SIOCGIFMTU, &ifr) != -1) 123 mtu = ifr.ifr_mtu; 124 else 125 mtu = 0; 126 prog_close(s); 127 128 return mtu; 129 } 130 131 /* give interface index and its old flags, then new flags returned */ 132 int 133 if_getflags(int ifindex, int oifflags) 134 { 135 struct ifreq ifr; 136 int s; 137 138 if ((s = prog_socket(AF_INET6, SOCK_DGRAM, 0)) < 0) { 139 logit(LOG_ERR, "<%s> socket: %m", __func__); 140 return (oifflags & ~IFF_UP); 141 } 142 143 memset(&ifr, 0, sizeof(ifr)); 144 if_indextoname(ifindex, ifr.ifr_name); 145 if (prog_ioctl(s, SIOCGIFFLAGS, &ifr) < 0) { 146 logit(LOG_ERR, "<%s> ioctl:SIOCGIFFLAGS: failed for %s", 147 __func__, ifr.ifr_name); 148 prog_close(s); 149 return (oifflags & ~IFF_UP); 150 } 151 prog_close(s); 152 return (ifr.ifr_flags); 153 } 154 155 #define ROUNDUP8(a) (1 + (((a) - 1) | 7)) 156 int 157 lladdropt_length(struct sockaddr_dl *sdl) 158 { 159 switch (sdl->sdl_type) { 160 case IFT_ETHER: 161 case IFT_FDDI: 162 return(ROUNDUP8(ETHER_ADDR_LEN + 2)); 163 default: 164 return(0); 165 } 166 } 167 168 void 169 lladdropt_fill(struct sockaddr_dl *sdl, struct nd_opt_hdr *ndopt) 170 { 171 char *addr; 172 173 ndopt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; /* fixed */ 174 175 switch (sdl->sdl_type) { 176 case IFT_ETHER: 177 case IFT_FDDI: 178 ndopt->nd_opt_len = (ROUNDUP8(ETHER_ADDR_LEN + 2)) >> 3; 179 addr = (char *)(ndopt + 1); 180 memcpy(addr, LLADDR(sdl), ETHER_ADDR_LEN); 181 break; 182 default: 183 logit(LOG_ERR, "<%s> unsupported link type(%d)", 184 __func__, sdl->sdl_type); 185 exit(1); 186 } 187 188 return; 189 } 190 191 #define FILTER_MATCH(type, filter) ((0x1 << type) & filter) 192 #define SIN6(s) ((struct sockaddr_in6 *)(s)) 193 #define SDL(s) ((struct sockaddr_dl *)(s)) 194 char * 195 get_next_msg(char *buf, char *lim, int ifindex, size_t *lenp, int filter) 196 { 197 struct rt_msghdr *rtm; 198 struct ifa_msghdr *ifam; 199 struct sockaddr *sa, *dst, *gw, *ifa, *rti_info[RTAX_MAX]; 200 201 *lenp = 0; 202 for (rtm = (struct rt_msghdr *)buf; 203 rtm < (struct rt_msghdr *)lim; 204 rtm = (struct rt_msghdr *)(((char *)rtm) + rtm->rtm_msglen)) { 205 /* just for safety */ 206 if (!rtm->rtm_msglen) { 207 logit(LOG_WARNING, "<%s> rtm_msglen is 0 " 208 "(buf=%p lim=%p rtm=%p)", __func__, 209 buf, lim, rtm); 210 break; 211 } 212 if (FILTER_MATCH(rtm->rtm_type, filter) == 0) { 213 continue; 214 } 215 216 switch (rtm->rtm_type) { 217 case RTM_GET: 218 case RTM_ADD: 219 case RTM_DELETE: 220 /* address related checks */ 221 sa = (struct sockaddr *)(rtm + 1); 222 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 223 if ((dst = rti_info[RTAX_DST]) == NULL || 224 dst->sa_family != AF_INET6) 225 continue; 226 227 if (IN6_IS_ADDR_LINKLOCAL(&SIN6(dst)->sin6_addr) || 228 IN6_IS_ADDR_MULTICAST(&SIN6(dst)->sin6_addr)) 229 continue; 230 231 if ((gw = rti_info[RTAX_GATEWAY]) == NULL || 232 gw->sa_family != AF_LINK) 233 continue; 234 if (ifindex && SDL(gw)->sdl_index != ifindex) 235 continue; 236 237 if (rti_info[RTAX_NETMASK] == NULL) 238 continue; 239 240 /* found */ 241 *lenp = rtm->rtm_msglen; 242 return (char *)rtm; 243 /* NOTREACHED */ 244 case RTM_NEWADDR: 245 case RTM_DELADDR: 246 ifam = (struct ifa_msghdr *)rtm; 247 248 /* address related checks */ 249 sa = (struct sockaddr *)(ifam + 1); 250 get_rtaddrs(ifam->ifam_addrs, sa, rti_info); 251 if ((ifa = rti_info[RTAX_IFA]) == NULL || 252 (ifa->sa_family != AF_INET && 253 ifa->sa_family != AF_INET6)) 254 continue; 255 256 if (ifa->sa_family == AF_INET6 && 257 (IN6_IS_ADDR_LINKLOCAL(&SIN6(ifa)->sin6_addr) || 258 IN6_IS_ADDR_MULTICAST(&SIN6(ifa)->sin6_addr))) 259 continue; 260 261 if (ifindex && ifam->ifam_index != ifindex) 262 continue; 263 264 /* found */ 265 *lenp = ifam->ifam_msglen; 266 return (char *)rtm; 267 /* NOTREACHED */ 268 #ifdef RTM_IFANNOUNCE 269 case RTM_IFANNOUNCE: 270 #endif 271 case RTM_IFINFO: 272 /* found */ 273 *lenp = rtm->rtm_msglen; 274 return (char *)rtm; 275 /* NOTREACHED */ 276 } 277 } 278 279 return (char *)rtm; 280 } 281 #undef FILTER_MATCH 282 283 struct in6_addr * 284 get_addr(char *buf) 285 { 286 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 287 struct sockaddr *sa, *rti_info[RTAX_MAX]; 288 289 sa = (struct sockaddr *)(rtm + 1); 290 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 291 292 return(&SIN6(rti_info[RTAX_DST])->sin6_addr); 293 } 294 295 int 296 get_rtm_ifindex(char *buf) 297 { 298 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 299 struct sockaddr *sa, *rti_info[RTAX_MAX]; 300 301 sa = (struct sockaddr *)(rtm + 1); 302 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 303 304 return(((struct sockaddr_dl *)rti_info[RTAX_GATEWAY])->sdl_index); 305 } 306 307 int 308 get_ifm_ifindex(char *buf) 309 { 310 struct if_msghdr *ifm = (struct if_msghdr *)buf; 311 312 return ((int)ifm->ifm_index); 313 } 314 315 int 316 get_ifam_ifindex(char *buf) 317 { 318 struct ifa_msghdr *ifam = (struct ifa_msghdr *)buf; 319 320 return ((int)ifam->ifam_index); 321 } 322 323 int 324 get_ifm_flags(char *buf) 325 { 326 struct if_msghdr *ifm = (struct if_msghdr *)buf; 327 328 return (ifm->ifm_flags); 329 } 330 331 #ifdef RTM_IFANNOUNCE 332 int 333 get_ifan_ifindex(char *buf) 334 { 335 struct if_announcemsghdr *ifan = (struct if_announcemsghdr *)buf; 336 337 return ((int)ifan->ifan_index); 338 } 339 340 int 341 get_ifan_what(char *buf) 342 { 343 struct if_announcemsghdr *ifan = (struct if_announcemsghdr *)buf; 344 345 return ((int)ifan->ifan_what); 346 } 347 #endif 348 349 int 350 get_prefixlen(char *buf) 351 { 352 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 353 struct sockaddr *sa, *rti_info[RTAX_MAX]; 354 unsigned char *p, *lim; 355 356 sa = (struct sockaddr *)(rtm + 1); 357 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 358 sa = rti_info[RTAX_NETMASK]; 359 360 p = (unsigned char *)(&SIN6(sa)->sin6_addr); 361 lim = (unsigned char *)sa + sa->sa_len; 362 return prefixlen(p, lim); 363 } 364 365 int 366 prefixlen(const unsigned char *p, const unsigned char *lim) 367 { 368 int masklen; 369 370 for (masklen = 0; p < lim; p++) { 371 switch (*p) { 372 case 0xff: 373 masklen += 8; 374 break; 375 case 0xfe: 376 masklen += 7; 377 break; 378 case 0xfc: 379 masklen += 6; 380 break; 381 case 0xf8: 382 masklen += 5; 383 break; 384 case 0xf0: 385 masklen += 4; 386 break; 387 case 0xe0: 388 masklen += 3; 389 break; 390 case 0xc0: 391 masklen += 2; 392 break; 393 case 0x80: 394 masklen += 1; 395 break; 396 case 0x00: 397 break; 398 default: 399 return(-1); 400 } 401 } 402 403 return(masklen); 404 } 405 406 int 407 rtmsg_type(char *buf) 408 { 409 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 410 411 return(rtm->rtm_type); 412 } 413 414 int 415 rtmsg_len(char *buf) 416 { 417 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 418 419 return(rtm->rtm_msglen); 420 } 421