NetBSD/usr.sbin/rtadvd/if.c

433 lines
9.4 KiB
C

/* $NetBSD: if.c,v 1.29 2021/03/23 18:16:53 christos 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.
*/
#define RTM_NAMES
#include <sys/param.h>
#include <sys/queue.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>
#ifdef __FreeBSD__
#include <net/ethernet.h>
#else
#include <net/if_ether.h>
#endif
#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"
#include "logit.h"
#include "prog_ops.h"
#ifndef RT_ROUNDUP
#define RT_ROUNDUP(a) \
((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
#define RT_ADVANCE(x, n) (x += RT_ROUNDUP((n)->sa_len))
#endif
static void
get_rtaddrs(int addrs, const struct sockaddr *sa,
const struct sockaddr **rti_info)
{
int i;
for (i = 0; i < RTAX_MAX; i++) {
if (addrs & (1 << i)) {
rti_info[i] = sa;
RT_ADVANCE(sa, sa);
}
else
rti_info[i] = NULL;
}
}
struct sockaddr_dl *
if_nametosdl(const 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(const char *name)
{
struct ifreq ifr;
int s, mtu;
if ((s = prog_socket(AF_INET6, SOCK_DGRAM, 0)) < 0)
return 0;
memset(&ifr, 0, sizeof(ifr));
ifr.ifr_addr.sa_family = AF_INET6;
strncpy(ifr.ifr_name, name, sizeof(ifr.ifr_name));
if (prog_ioctl(s, SIOCGIFMTU, &ifr) != -1)
mtu = ifr.ifr_mtu;
else
mtu = 0;
prog_close(s);
return mtu;
}
/* give interface index and its old flags, then new flags returned */
int
if_getflags(unsigned int ifindex, int oifflags)
{
struct ifreq ifr;
int s;
if ((s = prog_socket(AF_INET6, SOCK_DGRAM, 0)) < 0) {
logit(LOG_ERR, "%s: socket: %m", __func__);
return (oifflags & ~IFF_UP);
}
memset(&ifr, 0, sizeof(ifr));
if_indextoname(ifindex, ifr.ifr_name);
if (prog_ioctl(s, SIOCGIFFLAGS, &ifr) < 0) {
logit(LOG_ERR, "%s: ioctl:SIOCGIFFLAGS: failed for %s",
__func__, ifr.ifr_name);
prog_close(s);
return (oifflags & ~IFF_UP);
}
prog_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:
logit(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) ((const struct sockaddr_in6 *)(s))
#define SDL(s) ((const struct sockaddr_dl *)(s))
char *
get_next_msg(char *buf, char *lim, unsigned int ifindex, size_t *lenp,
int filter)
{
struct rt_msghdr *rtm;
struct ifa_msghdr *ifam;
const 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) {
logit(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 */
#ifdef RTM_IFANNOUNCE
case RTM_IFANNOUNCE:
#endif
case RTM_IFINFO:
/* found */
*lenp = rtm->rtm_msglen;
return (char *)rtm;
/* NOTREACHED */
}
}
return (char *)rtm;
}
#undef FILTER_MATCH
const struct in6_addr *
get_addr(const void *buf)
{
const struct rt_msghdr *rtm = buf;
const struct sockaddr *sa, *rti_info[RTAX_MAX];
sa = (const struct sockaddr *)(rtm + 1);
get_rtaddrs(rtm->rtm_addrs, sa, rti_info);
return &SIN6(rti_info[RTAX_DST])->sin6_addr;
}
unsigned int
get_rtm_ifindex(const void *buf)
{
const struct rt_msghdr *rtm = buf;
const struct sockaddr *sa, *rti_info[RTAX_MAX];
sa = (const struct sockaddr *)(rtm + 1);
get_rtaddrs(rtm->rtm_addrs, sa, rti_info);
return SDL(rti_info[RTAX_GATEWAY])->sdl_index;
}
unsigned int
get_ifm_ifindex(const void *buf)
{
const struct if_msghdr *ifm = buf;
return ifm->ifm_index;
}
unsigned int
get_ifam_ifindex(const void *buf)
{
const struct ifa_msghdr *ifam = buf;
return ifam->ifam_index;
}
int
get_ifm_flags(const void *buf)
{
const struct if_msghdr *ifm = buf;
return ifm->ifm_flags;
}
#ifdef RTM_IFANNOUNCE
unsigned int
get_ifan_ifindex(const void *buf)
{
const struct if_announcemsghdr *ifan = buf;
return ifan->ifan_index;
}
int
get_ifan_what(const void *buf)
{
const struct if_announcemsghdr *ifan = buf;
return (int)ifan->ifan_what;
}
#endif
int
get_prefixlen(const void *buf)
{
const struct rt_msghdr *rtm = buf;
const struct sockaddr *sa, *rti_info[RTAX_MAX];
const unsigned char *p, *lim;
sa = (const struct sockaddr *)(rtm + 1);
get_rtaddrs(rtm->rtm_addrs, sa, rti_info);
sa = rti_info[RTAX_NETMASK];
p = (const unsigned char *)(&SIN6(sa)->sin6_addr);
lim = (const unsigned char *)sa + sa->sa_len;
return prefixlen(p, lim);
}
int
prefixlen(const unsigned char *p, const unsigned 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(const void *buf)
{
const struct rt_msghdr *rtm = buf;
return rtm->rtm_type;
}
const char *
rtmsg_typestr(const void *buf)
{
const struct rt_msghdr *rtm = buf;
return rtm->rtm_type < __arraycount(rtm_names)
? rtm_names[rtm->rtm_type] : "*unknown*";
}
int
rtmsg_len(const void *buf)
{
const struct rt_msghdr *rtm = buf;
return rtm->rtm_msglen;
}