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if.c revision 1.5.4.2 
      1 /*	$NetBSD: if.c,v 1.5.4.2 2000/09/01 06:26:55 itojun Exp $	*/
      2 /*	$KAME: if.c,v 1.12 2000/08/31 16:35:29 itojun 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/socket.h>
     35 #include <sys/sysctl.h>
     36 #include <sys/ioctl.h>
     37 #include <net/if.h>
     38 #include <net/if_types.h>
     39 #ifdef __FreeBSD__
     40 # include <net/ethernet.h>
     41 #endif
     42 #include <ifaddrs.h>
     43 #ifdef __NetBSD__
     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 #ifdef __bsdi__
     51 # include <netinet/if_ether.h>
     52 #endif
     53 #ifdef __OpenBSD__
     54 #include <netinet/if_ether.h>
     55 #endif
     56 #include <unistd.h>
     57 #include <errno.h>
     58 #include <stdlib.h>
     59 #include <string.h>
     60 #include <syslog.h>
     61 #include "rtadvd.h"
     62 #include "if.h"
     63 
     64 #define ROUNDUP(a, size) \
     65 	(((a) & ((size)-1)) ? (1 + ((a) | ((size)-1))) : (a))
     66 
     67 #define NEXT_SA(ap) (ap) = (struct sockaddr *) \
     68 	((caddr_t)(ap) + ((ap)->sa_len ? ROUNDUP((ap)->sa_len,\
     69 						 sizeof(u_long)) :\
     70 			  			 sizeof(u_long)))
     71 
     72 struct if_msghdr **iflist;
     73 int iflist_init_ok;
     74 size_t ifblock_size;
     75 char *ifblock;
     76 
     77 static void get_iflist __P((char **buf, size_t *size));
     78 static void parse_iflist __P((struct if_msghdr ***ifmlist_p, char *buf,
     79 		       size_t bufsize));
     80 
     81 static void
     82 get_rtaddrs(int addrs, struct sockaddr *sa, struct sockaddr **rti_info)
     83 {
     84 	int i;
     85 
     86 	for (i = 0; i < RTAX_MAX; i++) {
     87 		if (addrs & (1 << i)) {
     88 			rti_info[i] = sa;
     89 			NEXT_SA(sa);
     90 		}
     91 		else
     92 			rti_info[i] = NULL;
     93 	}
     94 }
     95 
     96 struct sockaddr_dl *
     97 if_nametosdl(char *name)
     98 {
     99 	int mib[6] = {CTL_NET, AF_ROUTE, 0, 0, NET_RT_IFLIST, 0};
    100 	char *buf, *next, *lim;
    101 	size_t len;
    102 	struct if_msghdr *ifm;
    103 	struct sockaddr *sa, *rti_info[RTAX_MAX];
    104 	struct sockaddr_dl *sdl = NULL, *ret_sdl;
    105 
    106 	if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0)
    107 		return(NULL);
    108 	if ((buf = malloc(len)) == NULL)
    109 		return(NULL);
    110 	if (sysctl(mib, 6, buf, &len, NULL, 0) < 0) {
    111 		free(buf);
    112 		return(NULL);
    113 	}
    114 
    115 	lim = buf + len;
    116 	for (next = buf; next < lim; next += ifm->ifm_msglen) {
    117 		ifm = (struct if_msghdr *)next;
    118 		if (ifm->ifm_type == RTM_IFINFO) {
    119 			sa = (struct sockaddr *)(ifm + 1);
    120 			get_rtaddrs(ifm->ifm_addrs, sa, rti_info);
    121 			if ((sa = rti_info[RTAX_IFP]) != NULL) {
    122 				if (sa->sa_family == AF_LINK) {
    123 					sdl = (struct sockaddr_dl *)sa;
    124 					if (strlen(name) != sdl->sdl_nlen)
    125 						continue; /* not same len */
    126 					if (strncmp(&sdl->sdl_data[0],
    127 						    name,
    128 						    sdl->sdl_nlen) == 0) {
    129 						break;
    130 					}
    131 				}
    132 			}
    133 		}
    134 	}
    135 	if (next == lim) {
    136 		/* search failed */
    137 		free(buf);
    138 		return(NULL);
    139 	}
    140 
    141 	if ((ret_sdl = malloc(sdl->sdl_len)) == NULL)
    142 		return(NULL);
    143 	memcpy((caddr_t)ret_sdl, (caddr_t)sdl, sdl->sdl_len);
    144 	return(ret_sdl);
    145 }
    146 
    147 int
    148 if_getmtu(char *name)
    149 {
    150 #ifdef SIOCGIFMTU
    151 	struct ifreq ifr;
    152 	int s;
    153 
    154 	if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0)
    155 		return(0);
    156 
    157 	ifr.ifr_addr.sa_family = AF_INET6;
    158 	strncpy(ifr.ifr_name, name, sizeof(ifr.ifr_name));
    159 	if (ioctl(s, SIOCGIFMTU, (caddr_t)&ifr) < 0) {
    160 		close(s);
    161 		return(0);
    162 	}
    163 
    164 	close(s);
    165 
    166 	return(ifr.ifr_mtu);
    167 #else
    168 	struct ifaddrs *ifap, *ifa;
    169 	struct if_data *ifd;
    170 
    171 	if (getifaddrs(&ifap) < 0)
    172 		return(0);
    173 	for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
    174 		if (strcmp(ifa->ifa_name, name) == 0) {
    175 			ifd = ifa->ifa_data;
    176 			freeifaddrs(ifap);
    177 			if (ifd)
    178 				return ifd->ifi_mtu;
    179 			else
    180 				return 0;
    181 		}
    182 	}
    183 	freeifaddrs(ifap);
    184 	return 0;
    185 #endif
    186 }
    187 
    188 /* give interface index and its old flags, then new flags returned */
    189 int
    190 if_getflags(int ifindex, int oifflags)
    191 {
    192 	struct ifreq ifr;
    193 	int s;
    194 
    195 	if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
    196 		syslog(LOG_ERR, "<%s> socket: %s", __FUNCTION__,
    197 		       strerror(errno));
    198 		return (oifflags & ~IFF_UP);
    199 	}
    200 
    201 	if_indextoname(ifindex, ifr.ifr_name);
    202 	if (ioctl(s, SIOCGIFFLAGS, (caddr_t)&ifr) < 0) {
    203 		syslog(LOG_ERR, "<%s> ioctl:SIOCGIFFLAGS: failed for %s",
    204 		       __FUNCTION__, ifr.ifr_name);
    205 		close(s);
    206 		return (oifflags & ~IFF_UP);
    207 	}
    208 	close(s);
    209 	return (ifr.ifr_flags);
    210 }
    211 
    212 #define ROUNDUP8(a) (1 + (((a) - 1) | 7))
    213 int
    214 lladdropt_length(struct sockaddr_dl *sdl)
    215 {
    216 	switch(sdl->sdl_type) {
    217 	 case IFT_ETHER:
    218 		 return(ROUNDUP8(ETHER_ADDR_LEN + 2));
    219 	 default:
    220 		 return(0);
    221 	}
    222 }
    223 
    224 void
    225 lladdropt_fill(struct sockaddr_dl *sdl, struct nd_opt_hdr *ndopt)
    226 {
    227 	char *addr;
    228 
    229 	ndopt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; /* fixed */
    230 
    231 	switch(sdl->sdl_type) {
    232 	 case IFT_ETHER:
    233 		 ndopt->nd_opt_len = (ROUNDUP8(ETHER_ADDR_LEN + 2)) >> 3;
    234 		 addr = (char *)(ndopt + 1);
    235 		 memcpy(addr, LLADDR(sdl), ETHER_ADDR_LEN);
    236 		 break;
    237 	 default:
    238 		 syslog(LOG_ERR,
    239 			"<%s> unsupported link type(%d)",
    240 			__FUNCTION__, sdl->sdl_type);
    241 		 exit(1);
    242 	}
    243 
    244 	return;
    245 }
    246 
    247 int
    248 rtbuf_len()
    249 {
    250 	size_t len;
    251 
    252 	int mib[6] = {CTL_NET, AF_ROUTE, 0, AF_INET6, NET_RT_DUMP, 0};
    253 
    254 	if (sysctl(mib, 6, NULL, &len, NULL, 0) < 0)
    255 		return(-1);
    256 
    257 	return(len);
    258 }
    259 
    260 int
    261 get_rtinfo(char *buf, size_t *len)
    262 {
    263 	int mib[6] = {CTL_NET, AF_ROUTE, 0, AF_INET6, NET_RT_DUMP, 0};
    264 
    265 	if (sysctl(mib, 6, buf, len, NULL, 0) < 0)
    266 		return(-1);
    267 
    268 	return(0);
    269 }
    270 
    271 #define FILTER_MATCH(type, filter) ((0x1 << type) & filter)
    272 #define SIN6(s) ((struct sockaddr_in6 *)(s))
    273 #define SDL(s) ((struct sockaddr_dl *)(s))
    274 char *
    275 get_next_msg(char *buf, char *lim, int ifindex, size_t *lenp, int filter)
    276 {
    277 	struct rt_msghdr *rtm;
    278 	struct ifa_msghdr *ifam;
    279 	struct sockaddr *sa, *dst, *gw, *ifa, *rti_info[RTAX_MAX];
    280 
    281 	*lenp = 0;
    282 	for (rtm = (struct rt_msghdr *)buf;
    283 	     rtm < (struct rt_msghdr *)lim;
    284 	     rtm = (struct rt_msghdr *)(((char *)rtm) + rtm->rtm_msglen)) {
    285 		/* just for safety */
    286 		if (!rtm->rtm_msglen) {
    287 			syslog(LOG_WARNING, "<%s> rtm_msglen is 0 "
    288 				"(buf=%p lim=%p rtm=%p)", __FUNCTION__,
    289 				buf, lim, rtm);
    290 			break;
    291 		}
    292 		if (FILTER_MATCH(rtm->rtm_type, filter) == 0) {
    293 			continue;
    294 		}
    295 
    296 		switch (rtm->rtm_type) {
    297 		case RTM_GET:
    298 		case RTM_ADD:
    299 		case RTM_DELETE:
    300 			/* address related checks */
    301 			sa = (struct sockaddr *)(rtm + 1);
    302 			get_rtaddrs(rtm->rtm_addrs, sa, rti_info);
    303 			if ((dst = rti_info[RTAX_DST]) == NULL ||
    304 			    dst->sa_family != AF_INET6)
    305 				continue;
    306 
    307 			if (IN6_IS_ADDR_LINKLOCAL(&SIN6(dst)->sin6_addr) ||
    308 			    IN6_IS_ADDR_MULTICAST(&SIN6(dst)->sin6_addr))
    309 				continue;
    310 
    311 			if ((gw = rti_info[RTAX_GATEWAY]) == NULL ||
    312 			    gw->sa_family != AF_LINK)
    313 				continue;
    314 			if (ifindex && SDL(gw)->sdl_index != ifindex)
    315 				continue;
    316 
    317 			if (rti_info[RTAX_NETMASK] == NULL)
    318 				continue;
    319 
    320 			/* found */
    321 			*lenp = rtm->rtm_msglen;
    322 			return (char *)rtm;
    323 			/* NOTREACHED */
    324 		case RTM_NEWADDR:
    325 		case RTM_DELADDR:
    326 			ifam = (struct ifa_msghdr *)rtm;
    327 
    328 			/* address related checks */
    329 			sa = (struct sockaddr *)(ifam + 1);
    330 			get_rtaddrs(ifam->ifam_addrs, sa, rti_info);
    331 			if ((ifa = rti_info[RTAX_IFA]) == NULL ||
    332 			    (ifa->sa_family != AF_INET &&
    333 			     ifa->sa_family != AF_INET6))
    334 				continue;
    335 
    336 			if (ifa->sa_family == AF_INET6 &&
    337 			    (IN6_IS_ADDR_LINKLOCAL(&SIN6(ifa)->sin6_addr) ||
    338 			     IN6_IS_ADDR_MULTICAST(&SIN6(ifa)->sin6_addr)))
    339 				continue;
    340 
    341 			if (ifindex && ifam->ifam_index != ifindex)
    342 				continue;
    343 
    344 			/* found */
    345 			*lenp = ifam->ifam_msglen;
    346 			return (char *)rtm;
    347 			/* NOTREACHED */
    348 		case RTM_IFINFO:
    349 			/* found */
    350 			*lenp = rtm->rtm_msglen;
    351 			return (char *)rtm;
    352 			/* NOTREACHED */
    353 		}
    354 	}
    355 
    356 	return (char *)rtm;
    357 }
    358 #undef FILTER_MATCH(type, filter)
    359 
    360 struct in6_addr *
    361 get_addr(char *buf)
    362 {
    363 	struct rt_msghdr *rtm = (struct rt_msghdr *)buf;
    364 	struct sockaddr *sa, *rti_info[RTAX_MAX];
    365 
    366 	sa = (struct sockaddr *)(rtm + 1);
    367 	get_rtaddrs(rtm->rtm_addrs, sa, rti_info);
    368 
    369 	return(&SIN6(rti_info[RTAX_DST])->sin6_addr);
    370 }
    371 
    372 int
    373 get_rtm_ifindex(char *buf)
    374 {
    375 	struct rt_msghdr *rtm = (struct rt_msghdr *)buf;
    376 	struct sockaddr *sa, *rti_info[RTAX_MAX];
    377 
    378 	sa = (struct sockaddr *)(rtm + 1);
    379 	get_rtaddrs(rtm->rtm_addrs, sa, rti_info);
    380 
    381 	return(((struct sockaddr_dl *)rti_info[RTAX_GATEWAY])->sdl_index);
    382 }
    383 
    384 int
    385 get_ifm_ifindex(char *buf)
    386 {
    387 	struct if_msghdr *ifm = (struct if_msghdr *)buf;
    388 
    389 	return ((int)ifm->ifm_index);
    390 }
    391 
    392 int
    393 get_ifam_ifindex(char *buf)
    394 {
    395 	struct ifa_msghdr *ifam = (struct ifa_msghdr *)buf;
    396 
    397 	return ((int)ifam->ifam_index);
    398 }
    399 
    400 int
    401 get_ifm_flags(char *buf)
    402 {
    403 	struct if_msghdr *ifm = (struct if_msghdr *)buf;
    404 
    405 	return (ifm->ifm_flags);
    406 }
    407 
    408 int
    409 get_prefixlen(char *buf)
    410 {
    411 	struct rt_msghdr *rtm = (struct rt_msghdr *)buf;
    412 	struct sockaddr *sa, *rti_info[RTAX_MAX];
    413 	int masklen;
    414 	u_char *p, *lim;
    415 
    416 	sa = (struct sockaddr *)(rtm + 1);
    417 	get_rtaddrs(rtm->rtm_addrs, sa, rti_info);
    418 	sa = rti_info[RTAX_NETMASK];
    419 
    420 	p = (u_char *)(&SIN6(sa)->sin6_addr);
    421 	lim = (u_char *)sa + sa->sa_len;
    422 	for (masklen = 0; p < lim; p++) {
    423 		switch (*p) {
    424 		case 0xff:
    425 			masklen += 8;
    426 			break;
    427 		case 0xfe:
    428 			masklen += 7;
    429 			break;
    430 		case 0xfc:
    431 			masklen += 6;
    432 			break;
    433 		case 0xf8:
    434 			masklen += 5;
    435 			break;
    436 		case 0xf0:
    437 			masklen += 4;
    438 			break;
    439 		case 0xe0:
    440 			masklen += 3;
    441 			break;
    442 		case 0xc0:
    443 			masklen += 2;
    444 			break;
    445 		case 0x80:
    446 			masklen += 1;
    447 			break;
    448 		case 0x00:
    449 			break;
    450 		default:
    451 			return(-1);
    452 		}
    453 	}
    454 
    455 	return(masklen);
    456 }
    457 
    458 int
    459 rtmsg_type(char *buf)
    460 {
    461 	struct rt_msghdr *rtm = (struct rt_msghdr *)buf;
    462 
    463 	return(rtm->rtm_type);
    464 }
    465 
    466 int
    467 rtmsg_len(char *buf)
    468 {
    469 	struct rt_msghdr *rtm = (struct rt_msghdr *)buf;
    470 
    471 	return(rtm->rtm_msglen);
    472 }
    473 
    474 int
    475 ifmsg_len(char *buf)
    476 {
    477 	struct if_msghdr *ifm = (struct if_msghdr *)buf;
    478 
    479 	return(ifm->ifm_msglen);
    480 }
    481 
    482 /*
    483  * alloc buffer and get if_msghdrs block from kernel,
    484  * and put them into the buffer
    485  */
    486 static void
    487 get_iflist(char **buf, size_t *size)
    488 {
    489 	int mib[6];
    490 
    491 	mib[0] = CTL_NET;
    492 	mib[1] = PF_ROUTE;
    493 	mib[2] = 0;
    494 	mib[3] = AF_INET6;
    495 	mib[4] = NET_RT_IFLIST;
    496 	mib[5] = 0;
    497 
    498 	if (sysctl(mib, 6, NULL, size, NULL, 0) < 0) {
    499 		syslog(LOG_ERR, "<%s> sysctl: iflist size get failed",
    500 		       __FUNCTION__);
    501 		exit(1);
    502 	}
    503 	if ((*buf = malloc(*size)) == NULL) {
    504 		syslog(LOG_ERR, "<%s> malloc failed", __FUNCTION__);
    505 		exit(1);
    506 	}
    507 	if (sysctl(mib, 6, *buf, size, NULL, 0) < 0) {
    508 		syslog(LOG_ERR, "<%s> sysctl: iflist get failed",
    509 		       __FUNCTION__);
    510 		exit(1);
    511 	}
    512 	return;
    513 }
    514 
    515 /*
    516  * alloc buffer and parse if_msghdrs block passed as arg,
    517  * and init the buffer as list of pointers ot each of the if_msghdr.
    518  */
    519 static void
    520 parse_iflist(struct if_msghdr ***ifmlist_p, char *buf, size_t bufsize)
    521 {
    522 	int iflentry_size, malloc_size;
    523 	struct if_msghdr *ifm;
    524 	struct ifa_msghdr *ifam;
    525 	char *lim;
    526 
    527 	/*
    528 	 * Estimate least size of an iflist entry, to be obtained from kernel.
    529 	 * Should add sizeof(sockaddr) ??
    530 	 */
    531 	iflentry_size = sizeof(struct if_msghdr);
    532 	/* roughly estimate max list size of pointers to each if_msghdr */
    533 	malloc_size = (bufsize/iflentry_size) * sizeof(size_t);
    534 	if ((*ifmlist_p = (struct if_msghdr **)malloc(malloc_size)) == NULL) {
    535 		syslog(LOG_ERR, "<%s> malloc failed", __FUNCTION__);
    536 		exit(1);
    537 	}
    538 
    539 	lim = buf + bufsize;
    540 	for (ifm = (struct if_msghdr *)buf; ifm < (struct if_msghdr *)lim;) {
    541 		if (ifm->ifm_msglen == 0) {
    542 			syslog(LOG_WARNING, "<%s> ifm_msglen is 0 "
    543 			       "(buf=%p lim=%p ifm=%p)", __FUNCTION__,
    544 			       buf, lim, ifm);
    545 			return;
    546 		}
    547 
    548 		if (ifm->ifm_type == RTM_IFINFO) {
    549 			(*ifmlist_p)[ifm->ifm_index] = ifm;
    550 		} else {
    551 			syslog(LOG_ERR, "out of sync parsing NET_RT_IFLIST\n"
    552 			       "expected %d, got %d\n msglen = %d\n"
    553 			       "buf:%p, ifm:%p, lim:%p\n",
    554 			       RTM_IFINFO, ifm->ifm_type, ifm->ifm_msglen,
    555 			       buf, ifm, lim);
    556 			exit (1);
    557 		}
    558 		for (ifam = (struct ifa_msghdr *)
    559 			((char *)ifm + ifm->ifm_msglen);
    560 		     ifam < (struct ifa_msghdr *)lim;
    561 		     ifam = (struct ifa_msghdr *)
    562 		     	((char *)ifam + ifam->ifam_msglen)) {
    563 			/* just for safety */
    564 			if (!ifam->ifam_msglen) {
    565 				syslog(LOG_WARNING, "<%s> ifa_msglen is 0 "
    566 				       "(buf=%p lim=%p ifam=%p)", __FUNCTION__,
    567 				       buf, lim, ifam);
    568 				return;
    569 			}
    570 			if (ifam->ifam_type != RTM_NEWADDR)
    571 				break;
    572 		}
    573 		ifm = (struct if_msghdr *)ifam;
    574 	}
    575 }
    576 
    577 void
    578 init_iflist()
    579 {
    580 	if (ifblock) {
    581 		free(ifblock);
    582 		ifblock_size = 0;
    583 	}
    584 	if (iflist)
    585 		free(iflist);
    586 	/* get iflist block from kernel */
    587 	get_iflist(&ifblock, &ifblock_size);
    588 
    589 	/* make list of pointers to each if_msghdr */
    590 	parse_iflist(&iflist, ifblock, ifblock_size);
    591 }
    592