1 /* $NetBSD: if.c,v 1.24 2015/11/11 07:48:41 ozaki-r 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 "prog_ops.h" 59 60 #ifndef RT_ROUNDUP 61 #define RT_ROUNDUP(a) \ 62 ((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long)) 63 #define RT_ADVANCE(x, n) (x += RT_ROUNDUP((n)->sa_len)) 64 #endif 65 66 static void 67 get_rtaddrs(int addrs, struct sockaddr *sa, struct sockaddr **rti_info) 68 { 69 int i; 70 71 for (i = 0; i < RTAX_MAX; i++) { 72 if (addrs & (1 << i)) { 73 rti_info[i] = sa; 74 RT_ADVANCE(sa, sa); 75 } 76 else 77 rti_info[i] = NULL; 78 } 79 } 80 81 struct sockaddr_dl * 82 if_nametosdl(const char *name) 83 { 84 struct ifaddrs *ifap, *ifa; 85 struct sockaddr_dl *sdl; 86 87 if (getifaddrs(&ifap) != 0) 88 return (NULL); 89 90 for (ifa = ifap; ifa; ifa = ifa->ifa_next) { 91 if (strcmp(ifa->ifa_name, name) != 0) 92 continue; 93 if (ifa->ifa_addr->sa_family != AF_LINK) 94 continue; 95 96 sdl = malloc(ifa->ifa_addr->sa_len); 97 if (!sdl) 98 continue; /*XXX*/ 99 100 memcpy(sdl, ifa->ifa_addr, ifa->ifa_addr->sa_len); 101 freeifaddrs(ifap); 102 return (sdl); 103 } 104 105 freeifaddrs(ifap); 106 return (NULL); 107 } 108 109 int 110 if_getmtu(const char *name) 111 { 112 struct ifreq ifr; 113 int s, mtu; 114 115 if ((s = prog_socket(AF_INET6, SOCK_DGRAM, 0)) < 0) 116 return 0; 117 118 memset(&ifr, 0, sizeof(ifr)); 119 ifr.ifr_addr.sa_family = AF_INET6; 120 strncpy(ifr.ifr_name, name, sizeof(ifr.ifr_name)); 121 if (prog_ioctl(s, SIOCGIFMTU, &ifr) != -1) 122 mtu = ifr.ifr_mtu; 123 else 124 mtu = 0; 125 prog_close(s); 126 127 return mtu; 128 } 129 130 /* give interface index and its old flags, then new flags returned */ 131 int 132 if_getflags(int ifindex, int oifflags) 133 { 134 struct ifreq ifr; 135 int s; 136 137 if ((s = prog_socket(AF_INET6, SOCK_DGRAM, 0)) < 0) { 138 syslog(LOG_ERR, "<%s> socket: %m", __func__); 139 return (oifflags & ~IFF_UP); 140 } 141 142 memset(&ifr, 0, sizeof(ifr)); 143 if_indextoname(ifindex, ifr.ifr_name); 144 if (prog_ioctl(s, SIOCGIFFLAGS, &ifr) < 0) { 145 syslog(LOG_ERR, "<%s> ioctl:SIOCGIFFLAGS: failed for %s", 146 __func__, ifr.ifr_name); 147 prog_close(s); 148 return (oifflags & ~IFF_UP); 149 } 150 prog_close(s); 151 return (ifr.ifr_flags); 152 } 153 154 #define ROUNDUP8(a) (1 + (((a) - 1) | 7)) 155 int 156 lladdropt_length(struct sockaddr_dl *sdl) 157 { 158 switch (sdl->sdl_type) { 159 case IFT_ETHER: 160 case IFT_FDDI: 161 return(ROUNDUP8(ETHER_ADDR_LEN + 2)); 162 default: 163 return(0); 164 } 165 } 166 167 void 168 lladdropt_fill(struct sockaddr_dl *sdl, struct nd_opt_hdr *ndopt) 169 { 170 char *addr; 171 172 ndopt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; /* fixed */ 173 174 switch (sdl->sdl_type) { 175 case IFT_ETHER: 176 case IFT_FDDI: 177 ndopt->nd_opt_len = (ROUNDUP8(ETHER_ADDR_LEN + 2)) >> 3; 178 addr = (char *)(ndopt + 1); 179 memcpy(addr, LLADDR(sdl), ETHER_ADDR_LEN); 180 break; 181 default: 182 syslog(LOG_ERR, "<%s> unsupported link type(%d)", 183 __func__, sdl->sdl_type); 184 exit(1); 185 } 186 187 return; 188 } 189 190 #define FILTER_MATCH(type, filter) ((0x1 << type) & filter) 191 #define SIN6(s) ((struct sockaddr_in6 *)(s)) 192 #define SDL(s) ((struct sockaddr_dl *)(s)) 193 char * 194 get_next_msg(char *buf, char *lim, int ifindex, size_t *lenp, int filter) 195 { 196 struct rt_msghdr *rtm; 197 struct ifa_msghdr *ifam; 198 struct sockaddr *sa, *dst, *gw, *ifa, *rti_info[RTAX_MAX]; 199 200 *lenp = 0; 201 for (rtm = (struct rt_msghdr *)buf; 202 rtm < (struct rt_msghdr *)lim; 203 rtm = (struct rt_msghdr *)(((char *)rtm) + rtm->rtm_msglen)) { 204 /* just for safety */ 205 if (!rtm->rtm_msglen) { 206 syslog(LOG_WARNING, "<%s> rtm_msglen is 0 " 207 "(buf=%p lim=%p rtm=%p)", __func__, 208 buf, lim, rtm); 209 break; 210 } 211 if (FILTER_MATCH(rtm->rtm_type, filter) == 0) { 212 continue; 213 } 214 215 switch (rtm->rtm_type) { 216 case RTM_GET: 217 case RTM_ADD: 218 case RTM_DELETE: 219 /* address related checks */ 220 sa = (struct sockaddr *)(rtm + 1); 221 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 222 if ((dst = rti_info[RTAX_DST]) == NULL || 223 dst->sa_family != AF_INET6) 224 continue; 225 226 if (IN6_IS_ADDR_LINKLOCAL(&SIN6(dst)->sin6_addr) || 227 IN6_IS_ADDR_MULTICAST(&SIN6(dst)->sin6_addr)) 228 continue; 229 230 if ((gw = rti_info[RTAX_GATEWAY]) == NULL || 231 gw->sa_family != AF_LINK) 232 continue; 233 if (ifindex && SDL(gw)->sdl_index != ifindex) 234 continue; 235 236 if (rti_info[RTAX_NETMASK] == NULL) 237 continue; 238 239 /* found */ 240 *lenp = rtm->rtm_msglen; 241 return (char *)rtm; 242 /* NOTREACHED */ 243 case RTM_NEWADDR: 244 case RTM_DELADDR: 245 ifam = (struct ifa_msghdr *)rtm; 246 247 /* address related checks */ 248 sa = (struct sockaddr *)(ifam + 1); 249 get_rtaddrs(ifam->ifam_addrs, sa, rti_info); 250 if ((ifa = rti_info[RTAX_IFA]) == NULL || 251 (ifa->sa_family != AF_INET && 252 ifa->sa_family != AF_INET6)) 253 continue; 254 255 if (ifa->sa_family == AF_INET6 && 256 (IN6_IS_ADDR_LINKLOCAL(&SIN6(ifa)->sin6_addr) || 257 IN6_IS_ADDR_MULTICAST(&SIN6(ifa)->sin6_addr))) 258 continue; 259 260 if (ifindex && ifam->ifam_index != ifindex) 261 continue; 262 263 /* found */ 264 *lenp = ifam->ifam_msglen; 265 return (char *)rtm; 266 /* NOTREACHED */ 267 #ifdef RTM_IFANNOUNCE 268 case RTM_IFANNOUNCE: 269 #endif 270 case RTM_IFINFO: 271 /* found */ 272 *lenp = rtm->rtm_msglen; 273 return (char *)rtm; 274 /* NOTREACHED */ 275 } 276 } 277 278 return (char *)rtm; 279 } 280 #undef FILTER_MATCH 281 282 struct in6_addr * 283 get_addr(char *buf) 284 { 285 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 286 struct sockaddr *sa, *rti_info[RTAX_MAX]; 287 288 sa = (struct sockaddr *)(rtm + 1); 289 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 290 291 return(&SIN6(rti_info[RTAX_DST])->sin6_addr); 292 } 293 294 int 295 get_rtm_ifindex(char *buf) 296 { 297 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 298 struct sockaddr *sa, *rti_info[RTAX_MAX]; 299 300 sa = (struct sockaddr *)(rtm + 1); 301 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 302 303 return(((struct sockaddr_dl *)rti_info[RTAX_GATEWAY])->sdl_index); 304 } 305 306 int 307 get_ifm_ifindex(char *buf) 308 { 309 struct if_msghdr *ifm = (struct if_msghdr *)buf; 310 311 return ((int)ifm->ifm_index); 312 } 313 314 int 315 get_ifam_ifindex(char *buf) 316 { 317 struct ifa_msghdr *ifam = (struct ifa_msghdr *)buf; 318 319 return ((int)ifam->ifam_index); 320 } 321 322 int 323 get_ifm_flags(char *buf) 324 { 325 struct if_msghdr *ifm = (struct if_msghdr *)buf; 326 327 return (ifm->ifm_flags); 328 } 329 330 #ifdef RTM_IFANNOUNCE 331 int 332 get_ifan_ifindex(char *buf) 333 { 334 struct if_announcemsghdr *ifan = (struct if_announcemsghdr *)buf; 335 336 return ((int)ifan->ifan_index); 337 } 338 339 int 340 get_ifan_what(char *buf) 341 { 342 struct if_announcemsghdr *ifan = (struct if_announcemsghdr *)buf; 343 344 return ((int)ifan->ifan_what); 345 } 346 #endif 347 348 int 349 get_prefixlen(char *buf) 350 { 351 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 352 struct sockaddr *sa, *rti_info[RTAX_MAX]; 353 unsigned char *p, *lim; 354 355 sa = (struct sockaddr *)(rtm + 1); 356 get_rtaddrs(rtm->rtm_addrs, sa, rti_info); 357 sa = rti_info[RTAX_NETMASK]; 358 359 p = (unsigned char *)(&SIN6(sa)->sin6_addr); 360 lim = (unsigned char *)sa + sa->sa_len; 361 return prefixlen(p, lim); 362 } 363 364 int 365 prefixlen(const unsigned char *p, const unsigned char *lim) 366 { 367 int masklen; 368 369 for (masklen = 0; p < lim; p++) { 370 switch (*p) { 371 case 0xff: 372 masklen += 8; 373 break; 374 case 0xfe: 375 masklen += 7; 376 break; 377 case 0xfc: 378 masklen += 6; 379 break; 380 case 0xf8: 381 masklen += 5; 382 break; 383 case 0xf0: 384 masklen += 4; 385 break; 386 case 0xe0: 387 masklen += 3; 388 break; 389 case 0xc0: 390 masklen += 2; 391 break; 392 case 0x80: 393 masklen += 1; 394 break; 395 case 0x00: 396 break; 397 default: 398 return(-1); 399 } 400 } 401 402 return(masklen); 403 } 404 405 int 406 rtmsg_type(char *buf) 407 { 408 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 409 410 return(rtm->rtm_type); 411 } 412 413 int 414 rtmsg_len(char *buf) 415 { 416 struct rt_msghdr *rtm = (struct rt_msghdr *)buf; 417 418 return(rtm->rtm_msglen); 419 } 420