NetBSD/usr.sbin/rtadvd/if.c

544 lines
12 KiB
C

/* $NetBSD: if.c,v 1.18 2006/03/05 23:47:08 rpaulo Exp $ */
/* $KAME: if.c,v 1.36 2004/11/30 22:32:01 suz Exp $ */
/*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the project nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <net/if_types.h>
#include <ifaddrs.h>
#include <net/if_ether.h>
#include <net/route.h>
#include <net/if_dl.h>
#include <netinet/in.h>
#include <netinet/icmp6.h>
#include <unistd.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include "rtadvd.h"
#include "if.h"
#define ROUNDUP(a, size) \
(((a) & ((size)-1)) ? (1 + ((a) | ((size)-1))) : (a))
#define NEXT_SA(ap) (ap) = (struct sockaddr *) \
((caddr_t)(ap) + ((ap)->sa_len ? ROUNDUP((ap)->sa_len,\
sizeof(u_long)) :\
sizeof(u_long)))
struct if_msghdr **iflist;
int iflist_init_ok;
size_t ifblock_size;
char *ifblock;
static void get_iflist __P((char **buf, size_t *size));
static void parse_iflist __P((struct if_msghdr ***ifmlist_p, char *buf,
size_t bufsize));
static void
get_rtaddrs(int addrs, struct sockaddr *sa, struct sockaddr **rti_info)
{
int i;
for (i = 0; i < RTAX_MAX; i++) {
if (addrs & (1 << i)) {
rti_info[i] = sa;
NEXT_SA(sa);
}
else
rti_info[i] = NULL;
}
}
struct sockaddr_dl *
if_nametosdl(char *name)
{
struct ifaddrs *ifap, *ifa;
struct sockaddr_dl *sdl;
if (getifaddrs(&ifap) != 0)
return (NULL);
for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
if (strcmp(ifa->ifa_name, name) != 0)
continue;
if (ifa->ifa_addr->sa_family != AF_LINK)
continue;
sdl = malloc(ifa->ifa_addr->sa_len);
if (!sdl)
continue; /*XXX*/
memcpy(sdl, ifa->ifa_addr, ifa->ifa_addr->sa_len);
freeifaddrs(ifap);
return (sdl);
}
freeifaddrs(ifap);
return (NULL);
}
int
if_getmtu(char *name)
{
struct ifaddrs *ifap, *ifa;
struct if_data *ifd;
u_long mtu = 0;
if (getifaddrs(&ifap) < 0)
return(0);
for (ifa = ifap; ifa; ifa = ifa->ifa_next) {
if (strcmp(ifa->ifa_name, name) == 0) {
ifd = ifa->ifa_data;
if (ifd)
mtu = ifd->ifi_mtu;
break;
}
}
freeifaddrs(ifap);
#ifdef SIOCGIFMTU /* XXX: this ifdef may not be necessary */
if (mtu == 0) {
struct ifreq ifr;
int s;
if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0)
return(0);
ifr.ifr_addr.sa_family = AF_INET6;
strncpy(ifr.ifr_name, name,
sizeof(ifr.ifr_name));
if (ioctl(s, SIOCGIFMTU, (caddr_t)&ifr) < 0) {
close(s);
return(0);
}
close(s);
mtu = ifr.ifr_mtu;
}
#endif
return(mtu);
}
/* give interface index and its old flags, then new flags returned */
int
if_getflags(int ifindex, int oifflags)
{
struct ifreq ifr;
int s;
if ((s = socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
syslog(LOG_ERR, "<%s> socket: %s", __func__,
strerror(errno));
return (oifflags & ~IFF_UP);
}
if_indextoname(ifindex, ifr.ifr_name);
if (ioctl(s, SIOCGIFFLAGS, (caddr_t)&ifr) < 0) {
syslog(LOG_ERR, "<%s> ioctl:SIOCGIFFLAGS: failed for %s",
__func__, ifr.ifr_name);
close(s);
return (oifflags & ~IFF_UP);
}
close(s);
return (ifr.ifr_flags);
}
#define ROUNDUP8(a) (1 + (((a) - 1) | 7))
int
lladdropt_length(struct sockaddr_dl *sdl)
{
switch (sdl->sdl_type) {
case IFT_ETHER:
case IFT_FDDI:
return(ROUNDUP8(ETHER_ADDR_LEN + 2));
default:
return(0);
}
}
void
lladdropt_fill(struct sockaddr_dl *sdl, struct nd_opt_hdr *ndopt)
{
char *addr;
ndopt->nd_opt_type = ND_OPT_SOURCE_LINKADDR; /* fixed */
switch (sdl->sdl_type) {
case IFT_ETHER:
case IFT_FDDI:
ndopt->nd_opt_len = (ROUNDUP8(ETHER_ADDR_LEN + 2)) >> 3;
addr = (char *)(ndopt + 1);
memcpy(addr, LLADDR(sdl), ETHER_ADDR_LEN);
break;
default:
syslog(LOG_ERR, "<%s> unsupported link type(%d)",
__func__, sdl->sdl_type);
exit(1);
}
return;
}
#define FILTER_MATCH(type, filter) ((0x1 << type) & filter)
#define SIN6(s) ((struct sockaddr_in6 *)(s))
#define SDL(s) ((struct sockaddr_dl *)(s))
char *
get_next_msg(char *buf, char *lim, int ifindex, size_t *lenp, int filter)
{
struct rt_msghdr *rtm;
struct ifa_msghdr *ifam;
struct sockaddr *sa, *dst, *gw, *ifa, *rti_info[RTAX_MAX];
*lenp = 0;
for (rtm = (struct rt_msghdr *)buf;
rtm < (struct rt_msghdr *)lim;
rtm = (struct rt_msghdr *)(((char *)rtm) + rtm->rtm_msglen)) {
/* just for safety */
if (!rtm->rtm_msglen) {
syslog(LOG_WARNING, "<%s> rtm_msglen is 0 "
"(buf=%p lim=%p rtm=%p)", __func__,
buf, lim, rtm);
break;
}
if (FILTER_MATCH(rtm->rtm_type, filter) == 0) {
continue;
}
switch (rtm->rtm_type) {
case RTM_GET:
case RTM_ADD:
case RTM_DELETE:
/* address related checks */
sa = (struct sockaddr *)(rtm + 1);
get_rtaddrs(rtm->rtm_addrs, sa, rti_info);
if ((dst = rti_info[RTAX_DST]) == NULL ||
dst->sa_family != AF_INET6)
continue;
if (IN6_IS_ADDR_LINKLOCAL(&SIN6(dst)->sin6_addr) ||
IN6_IS_ADDR_MULTICAST(&SIN6(dst)->sin6_addr))
continue;
if ((gw = rti_info[RTAX_GATEWAY]) == NULL ||
gw->sa_family != AF_LINK)
continue;
if (ifindex && SDL(gw)->sdl_index != ifindex)
continue;
if (rti_info[RTAX_NETMASK] == NULL)
continue;
/* found */
*lenp = rtm->rtm_msglen;
return (char *)rtm;
/* NOTREACHED */
case RTM_NEWADDR:
case RTM_DELADDR:
ifam = (struct ifa_msghdr *)rtm;
/* address related checks */
sa = (struct sockaddr *)(ifam + 1);
get_rtaddrs(ifam->ifam_addrs, sa, rti_info);
if ((ifa = rti_info[RTAX_IFA]) == NULL ||
(ifa->sa_family != AF_INET &&
ifa->sa_family != AF_INET6))
continue;
if (ifa->sa_family == AF_INET6 &&
(IN6_IS_ADDR_LINKLOCAL(&SIN6(ifa)->sin6_addr) ||
IN6_IS_ADDR_MULTICAST(&SIN6(ifa)->sin6_addr)))
continue;
if (ifindex && ifam->ifam_index != ifindex)
continue;
/* found */
*lenp = ifam->ifam_msglen;
return (char *)rtm;
/* NOTREACHED */
case RTM_IFINFO:
/* found */
*lenp = rtm->rtm_msglen;
return (char *)rtm;
/* NOTREACHED */
}
}
return (char *)rtm;
}
#undef FILTER_MATCH
struct in6_addr *
get_addr(char *buf)
{
struct rt_msghdr *rtm = (struct rt_msghdr *)buf;
struct sockaddr *sa, *rti_info[RTAX_MAX];
sa = (struct sockaddr *)(rtm + 1);
get_rtaddrs(rtm->rtm_addrs, sa, rti_info);
return(&SIN6(rti_info[RTAX_DST])->sin6_addr);
}
int
get_rtm_ifindex(char *buf)
{
struct rt_msghdr *rtm = (struct rt_msghdr *)buf;
struct sockaddr *sa, *rti_info[RTAX_MAX];
sa = (struct sockaddr *)(rtm + 1);
get_rtaddrs(rtm->rtm_addrs, sa, rti_info);
return(((struct sockaddr_dl *)rti_info[RTAX_GATEWAY])->sdl_index);
}
int
get_ifm_ifindex(char *buf)
{
struct if_msghdr *ifm = (struct if_msghdr *)buf;
return ((int)ifm->ifm_index);
}
int
get_ifam_ifindex(char *buf)
{
struct ifa_msghdr *ifam = (struct ifa_msghdr *)buf;
return ((int)ifam->ifam_index);
}
int
get_ifm_flags(char *buf)
{
struct if_msghdr *ifm = (struct if_msghdr *)buf;
return (ifm->ifm_flags);
}
int
get_prefixlen(char *buf)
{
struct rt_msghdr *rtm = (struct rt_msghdr *)buf;
struct sockaddr *sa, *rti_info[RTAX_MAX];
u_char *p, *lim;
sa = (struct sockaddr *)(rtm + 1);
get_rtaddrs(rtm->rtm_addrs, sa, rti_info);
sa = rti_info[RTAX_NETMASK];
p = (u_char *)(&SIN6(sa)->sin6_addr);
lim = (u_char *)sa + sa->sa_len;
return prefixlen(p, lim);
}
int
prefixlen(u_char *p, u_char *lim)
{
int masklen;
for (masklen = 0; p < lim; p++) {
switch (*p) {
case 0xff:
masklen += 8;
break;
case 0xfe:
masklen += 7;
break;
case 0xfc:
masklen += 6;
break;
case 0xf8:
masklen += 5;
break;
case 0xf0:
masklen += 4;
break;
case 0xe0:
masklen += 3;
break;
case 0xc0:
masklen += 2;
break;
case 0x80:
masklen += 1;
break;
case 0x00:
break;
default:
return(-1);
}
}
return(masklen);
}
int
rtmsg_type(char *buf)
{
struct rt_msghdr *rtm = (struct rt_msghdr *)buf;
return(rtm->rtm_type);
}
int
rtmsg_len(char *buf)
{
struct rt_msghdr *rtm = (struct rt_msghdr *)buf;
return(rtm->rtm_msglen);
}
int
ifmsg_len(char *buf)
{
struct if_msghdr *ifm = (struct if_msghdr *)buf;
return(ifm->ifm_msglen);
}
/*
* alloc buffer and get if_msghdrs block from kernel,
* and put them into the buffer
*/
static void
get_iflist(char **buf, size_t *size)
{
int mib[6];
mib[0] = CTL_NET;
mib[1] = PF_ROUTE;
mib[2] = 0;
mib[3] = AF_INET6;
mib[4] = NET_RT_IFLIST;
mib[5] = 0;
if (sysctl(mib, 6, NULL, size, NULL, 0) < 0) {
syslog(LOG_ERR, "<%s> sysctl: iflist size get failed",
__func__);
exit(1);
}
if ((*buf = malloc(*size)) == NULL) {
syslog(LOG_ERR, "<%s> malloc failed", __func__);
exit(1);
}
if (sysctl(mib, 6, *buf, size, NULL, 0) < 0) {
syslog(LOG_ERR, "<%s> sysctl: iflist get failed",
__func__);
exit(1);
}
return;
}
/*
* alloc buffer and parse if_msghdrs block passed as arg,
* and init the buffer as list of pointers ot each of the if_msghdr.
*/
static void
parse_iflist(struct if_msghdr ***ifmlist_p, char *buf, size_t bufsize)
{
int iflentry_size, malloc_size;
struct if_msghdr *ifm;
struct ifa_msghdr *ifam;
char *lim;
/*
* Estimate least size of an iflist entry, to be obtained from kernel.
* Should add sizeof(sockaddr) ??
*/
iflentry_size = sizeof(struct if_msghdr);
/* roughly estimate max list size of pointers to each if_msghdr */
malloc_size = (bufsize/iflentry_size) * sizeof(void *);
if ((*ifmlist_p = (struct if_msghdr **)malloc(malloc_size)) == NULL) {
syslog(LOG_ERR, "<%s> malloc failed", __func__);
exit(1);
}
lim = buf + bufsize;
for (ifm = (struct if_msghdr *)buf; ifm < (struct if_msghdr *)lim;) {
if (ifm->ifm_msglen == 0) {
syslog(LOG_WARNING, "<%s> ifm_msglen is 0 "
"(buf=%p lim=%p ifm=%p)", __func__,
buf, lim, ifm);
return;
}
if (ifm->ifm_type == RTM_IFINFO) {
(*ifmlist_p)[ifm->ifm_index] = ifm;
} else {
syslog(LOG_ERR, "out of sync parsing NET_RT_IFLIST\n"
"expected %d, got %d\n msglen = %d\n"
"buf:%p, ifm:%p, lim:%p\n",
RTM_IFINFO, ifm->ifm_type, ifm->ifm_msglen,
buf, ifm, lim);
exit (1);
}
for (ifam = (struct ifa_msghdr *)
((char *)ifm + ifm->ifm_msglen);
ifam < (struct ifa_msghdr *)lim;
ifam = (struct ifa_msghdr *)
((char *)ifam + ifam->ifam_msglen)) {
/* just for safety */
if (!ifam->ifam_msglen) {
syslog(LOG_WARNING, "<%s> ifa_msglen is 0 "
"(buf=%p lim=%p ifam=%p)", __func__,
buf, lim, ifam);
return;
}
if (ifam->ifam_type != RTM_NEWADDR)
break;
}
ifm = (struct if_msghdr *)ifam;
}
}
void
init_iflist()
{
if (ifblock) {
free(ifblock);
ifblock_size = 0;
}
if (iflist)
free(iflist);
/* get iflist block from kernel */
get_iflist(&ifblock, &ifblock_size);
/* make list of pointers to each if_msghdr */
parse_iflist(&iflist, ifblock, ifblock_size);
}