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freebsd-skq/usr.sbin/rtsold/rtsol.c
markj e3e51c190e rtsold: Log messages about unexpected RAs at LOG_DEBUG. 
Because rtsold listens for RAs on a raw socket, it may receive RAs from
interfaces that it does not manage. Such events can result in excessive
logging.

Submitted by:	Franco Fichtner <franco@opnsense.org>
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D8108
2016-10-02 00:56:21 +00:00

956 lines
26 KiB
C
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/* $KAME: rtsol.c,v 1.27 2003/10/05 00:09:36 itojun Exp $ */
/*
* Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
* Copyright (C) 2011 Hiroki Sato
* 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.
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/uio.h>
#include <sys/queue.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <net/if.h>
#include <net/route.h>
#include <net/if_dl.h>
#define __BSD_VISIBLE 1 /* IN6ADDR_LINKLOCAL_ALLROUTERS_INIT */
#include <netinet/in.h>
#undef __BSD_VISIBLE
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet/icmp6.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <time.h>
#include <fcntl.h>
#include <unistd.h>
#include <stdio.h>
#include <time.h>
#include <err.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <syslog.h>
#include "rtsold.h"
static struct msghdr rcvmhdr;
static struct msghdr sndmhdr;
static struct iovec rcviov[2];
static struct iovec sndiov[2];
static struct sockaddr_in6 from;
static int rcvcmsglen;
int rssock;
static char rsid[IFNAMSIZ + 1 + sizeof(DNSINFO_ORIGIN_LABEL) + 1 + NI_MAXHOST];
struct ifinfo_head_t ifinfo_head =
TAILQ_HEAD_INITIALIZER(ifinfo_head);
static const struct sockaddr_in6 sin6_allrouters = {
.sin6_len = sizeof(sin6_allrouters),
.sin6_family = AF_INET6,
.sin6_addr = IN6ADDR_LINKLOCAL_ALLROUTERS_INIT,
};
static void call_script(const int, const char *const *,
struct script_msg_head_t *);
static size_t dname_labeldec(char *, size_t, const char *);
static int safefile(const char *);
static struct ra_opt *find_raopt(struct rainfo *, int, void *, size_t);
static int ra_opt_rdnss_dispatch(struct ifinfo *, struct rainfo *,
struct script_msg_head_t *, struct script_msg_head_t *);
static char *make_rsid(const char *, const char *, struct rainfo *);
#define _ARGS_OTHER otherconf_script, ifi->ifname
#define _ARGS_RESADD resolvconf_script, "-a", rsid
#define _ARGS_RESDEL resolvconf_script, "-d", rsid
#define CALL_SCRIPT(name, sm_head) \
do { \
const char *const sarg[] = { _ARGS_##name, NULL }; \
call_script(sizeof(sarg), sarg, sm_head); \
} while(0)
#define ELM_MALLOC(p,error_action) \
do { \
p = malloc(sizeof(*p)); \
if (p == NULL) { \
warnmsg(LOG_ERR, __func__, "malloc failed: %s", \
strerror(errno)); \
error_action; \
} \
memset(p, 0, sizeof(*p)); \
} while(0)
int
sockopen(void)
{
static u_char *rcvcmsgbuf = NULL, *sndcmsgbuf = NULL;
int sndcmsglen, on;
static u_char answer[1500];
struct icmp6_filter filt;
sndcmsglen = rcvcmsglen = CMSG_SPACE(sizeof(struct in6_pktinfo)) +
CMSG_SPACE(sizeof(int));
if (rcvcmsgbuf == NULL && (rcvcmsgbuf = malloc(rcvcmsglen)) == NULL) {
warnmsg(LOG_ERR, __func__,
"malloc for receive msghdr failed");
return (-1);
}
if (sndcmsgbuf == NULL && (sndcmsgbuf = malloc(sndcmsglen)) == NULL) {
warnmsg(LOG_ERR, __func__,
"malloc for send msghdr failed");
return (-1);
}
if ((rssock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) {
warnmsg(LOG_ERR, __func__, "socket: %s", strerror(errno));
return (-1);
}
/* specify to tell receiving interface */
on = 1;
if (setsockopt(rssock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,
sizeof(on)) < 0) {
warnmsg(LOG_ERR, __func__, "IPV6_RECVPKTINFO: %s",
strerror(errno));
exit(1);
}
/* specify to tell value of hoplimit field of received IP6 hdr */
on = 1;
if (setsockopt(rssock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,
sizeof(on)) < 0) {
warnmsg(LOG_ERR, __func__, "IPV6_RECVHOPLIMIT: %s",
strerror(errno));
exit(1);
}
/* specfiy to accept only router advertisements on the socket */
ICMP6_FILTER_SETBLOCKALL(&filt);
ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
if (setsockopt(rssock, IPPROTO_ICMPV6, ICMP6_FILTER, &filt,
sizeof(filt)) == -1) {
warnmsg(LOG_ERR, __func__, "setsockopt(ICMP6_FILTER): %s",
strerror(errno));
return(-1);
}
/* initialize msghdr for receiving packets */
rcviov[0].iov_base = (caddr_t)answer;
rcviov[0].iov_len = sizeof(answer);
rcvmhdr.msg_name = (caddr_t)&from;
rcvmhdr.msg_iov = rcviov;
rcvmhdr.msg_iovlen = 1;
rcvmhdr.msg_control = (caddr_t) rcvcmsgbuf;
/* initialize msghdr for sending packets */
sndmhdr.msg_namelen = sizeof(struct sockaddr_in6);
sndmhdr.msg_iov = sndiov;
sndmhdr.msg_iovlen = 1;
sndmhdr.msg_control = (caddr_t)sndcmsgbuf;
sndmhdr.msg_controllen = sndcmsglen;
return (rssock);
}
void
sendpacket(struct ifinfo *ifi)
{
struct in6_pktinfo *pi;
struct cmsghdr *cm;
int hoplimit = 255;
ssize_t i;
struct sockaddr_in6 dst;
dst = sin6_allrouters;
dst.sin6_scope_id = ifi->linkid;
sndmhdr.msg_name = (caddr_t)&dst;
sndmhdr.msg_iov[0].iov_base = (caddr_t)ifi->rs_data;
sndmhdr.msg_iov[0].iov_len = ifi->rs_datalen;
cm = CMSG_FIRSTHDR(&sndmhdr);
/* specify the outgoing interface */
cm->cmsg_level = IPPROTO_IPV6;
cm->cmsg_type = IPV6_PKTINFO;
cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
pi = (struct in6_pktinfo *)(void *)CMSG_DATA(cm);
memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr)); /*XXX*/
pi->ipi6_ifindex = ifi->sdl->sdl_index;
/* specify the hop limit of the packet */
cm = CMSG_NXTHDR(&sndmhdr, cm);
cm->cmsg_level = IPPROTO_IPV6;
cm->cmsg_type = IPV6_HOPLIMIT;
cm->cmsg_len = CMSG_LEN(sizeof(int));
memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int));
warnmsg(LOG_DEBUG, __func__,
"send RS on %s, whose state is %d",
ifi->ifname, ifi->state);
i = sendmsg(rssock, &sndmhdr, 0);
if (i < 0 || (size_t)i != ifi->rs_datalen) {
/*
* ENETDOWN is not so serious, especially when using several
* network cards on a mobile node. We ignore it.
*/
if (errno != ENETDOWN || dflag > 0)
warnmsg(LOG_ERR, __func__, "sendmsg on %s: %s",
ifi->ifname, strerror(errno));
}
/* update counter */
ifi->probes++;
}
void
rtsol_input(int s)
{
char ntopbuf[INET6_ADDRSTRLEN], ifnamebuf[IFNAMSIZ];
int l, ifindex = 0, *hlimp = NULL;
ssize_t msglen;
struct in6_pktinfo *pi = NULL;
struct ifinfo *ifi = NULL;
struct ra_opt *rao = NULL;
struct icmp6_hdr *icp;
struct nd_router_advert *nd_ra;
struct cmsghdr *cm;
struct rainfo *rai;
char *raoptp;
char *p;
struct in6_addr *addr;
struct nd_opt_hdr *ndo;
struct nd_opt_rdnss *rdnss;
struct nd_opt_dnssl *dnssl;
size_t len;
char nsbuf[INET6_ADDRSTRLEN + 1 + IFNAMSIZ + 1];
char dname[NI_MAXHOST];
struct timespec now;
struct timespec lifetime;
int newent_rai;
int newent_rao;
/* get message. namelen and controllen must always be initialized. */
rcvmhdr.msg_namelen = sizeof(from);
rcvmhdr.msg_controllen = rcvcmsglen;
if ((msglen = recvmsg(s, &rcvmhdr, 0)) < 0) {
warnmsg(LOG_ERR, __func__, "recvmsg: %s", strerror(errno));
return;
}
/* extract optional information via Advanced API */
for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&rcvmhdr); cm;
cm = (struct cmsghdr *)CMSG_NXTHDR(&rcvmhdr, cm)) {
if (cm->cmsg_level == IPPROTO_IPV6 &&
cm->cmsg_type == IPV6_PKTINFO &&
cm->cmsg_len == CMSG_LEN(sizeof(struct in6_pktinfo))) {
pi = (struct in6_pktinfo *)(void *)(CMSG_DATA(cm));
ifindex = pi->ipi6_ifindex;
}
if (cm->cmsg_level == IPPROTO_IPV6 &&
cm->cmsg_type == IPV6_HOPLIMIT &&
cm->cmsg_len == CMSG_LEN(sizeof(int)))
hlimp = (int *)(void *)CMSG_DATA(cm);
}
if (ifindex == 0) {
warnmsg(LOG_ERR, __func__,
"failed to get receiving interface");
return;
}
if (hlimp == NULL) {
warnmsg(LOG_ERR, __func__,
"failed to get receiving hop limit");
return;
}
if ((size_t)msglen < sizeof(struct nd_router_advert)) {
warnmsg(LOG_INFO, __func__,
"packet size(%zd) is too short", msglen);
return;
}
icp = (struct icmp6_hdr *)rcvmhdr.msg_iov[0].iov_base;
if (icp->icmp6_type != ND_ROUTER_ADVERT) {
/*
* this should not happen because we configured a filter
* that only passes RAs on the receiving socket.
*/
warnmsg(LOG_ERR, __func__,
"invalid icmp type(%d) from %s on %s", icp->icmp6_type,
inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
sizeof(ntopbuf)),
if_indextoname(pi->ipi6_ifindex, ifnamebuf));
return;
}
if (icp->icmp6_code != 0) {
warnmsg(LOG_INFO, __func__,
"invalid icmp code(%d) from %s on %s", icp->icmp6_code,
inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
sizeof(ntopbuf)),
if_indextoname(pi->ipi6_ifindex, ifnamebuf));
return;
}
if (*hlimp != 255) {
warnmsg(LOG_INFO, __func__,
"invalid RA with hop limit(%d) from %s on %s",
*hlimp,
inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
sizeof(ntopbuf)),
if_indextoname(pi->ipi6_ifindex, ifnamebuf));
return;
}
if (pi && !IN6_IS_ADDR_LINKLOCAL(&from.sin6_addr)) {
warnmsg(LOG_INFO, __func__,
"invalid RA with non link-local source from %s on %s",
inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
sizeof(ntopbuf)),
if_indextoname(pi->ipi6_ifindex, ifnamebuf));
return;
}
/* xxx: more validation? */
if ((ifi = find_ifinfo(pi->ipi6_ifindex)) == NULL) {
warnmsg(LOG_DEBUG, __func__,
"received RA from %s on an unexpected IF(%s)",
inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf,
sizeof(ntopbuf)),
if_indextoname(pi->ipi6_ifindex, ifnamebuf));
return;
}
warnmsg(LOG_DEBUG, __func__,
"received RA from %s on %s, state is %d",
inet_ntop(AF_INET6, &from.sin6_addr, ntopbuf, sizeof(ntopbuf)),
ifi->ifname, ifi->state);
nd_ra = (struct nd_router_advert *)icp;
/*
* Process the "O bit."
* If the value of OtherConfigFlag changes from FALSE to TRUE, the
* host should invoke the stateful autoconfiguration protocol,
* requesting information.
* [RFC 2462 Section 5.5.3]
*/
if (((nd_ra->nd_ra_flags_reserved) & ND_RA_FLAG_OTHER) &&
!ifi->otherconfig) {
warnmsg(LOG_DEBUG, __func__,
"OtherConfigFlag on %s is turned on", ifi->ifname);
ifi->otherconfig = 1;
CALL_SCRIPT(OTHER, NULL);
}
clock_gettime(CLOCK_MONOTONIC_FAST, &now);
newent_rai = 0;
rai = find_rainfo(ifi, &from);
if (rai == NULL) {
ELM_MALLOC(rai, exit(1));
rai->rai_ifinfo = ifi;
TAILQ_INIT(&rai->rai_ra_opt);
rai->rai_saddr.sin6_family = AF_INET6;
rai->rai_saddr.sin6_len = sizeof(rai->rai_saddr);
memcpy(&rai->rai_saddr.sin6_addr, &from.sin6_addr,
sizeof(rai->rai_saddr.sin6_addr));
newent_rai = 1;
}
#define RA_OPT_NEXT_HDR(x) (struct nd_opt_hdr *)((char *)x + \
(((struct nd_opt_hdr *)x)->nd_opt_len * 8))
/* Process RA options. */
warnmsg(LOG_DEBUG, __func__, "Processing RA");
raoptp = (char *)icp + sizeof(struct nd_router_advert);
while (raoptp < (char *)icp + msglen) {
ndo = (struct nd_opt_hdr *)raoptp;
warnmsg(LOG_DEBUG, __func__, "ndo = %p", raoptp);
warnmsg(LOG_DEBUG, __func__, "ndo->nd_opt_type = %d",
ndo->nd_opt_type);
warnmsg(LOG_DEBUG, __func__, "ndo->nd_opt_len = %d",
ndo->nd_opt_len);
switch (ndo->nd_opt_type) {
case ND_OPT_RDNSS:
rdnss = (struct nd_opt_rdnss *)raoptp;
/* Optlen sanity check (Section 5.3.1 in RFC 6106) */
if (rdnss->nd_opt_rdnss_len < 3) {
warnmsg(LOG_INFO, __func__,
"too short RDNSS option"
"in RA from %s was ignored.",
inet_ntop(AF_INET6, &from.sin6_addr,
ntopbuf, sizeof(ntopbuf)));
break;
}
addr = (struct in6_addr *)(void *)(raoptp + sizeof(*rdnss));
while ((char *)addr < (char *)RA_OPT_NEXT_HDR(raoptp)) {
if (inet_ntop(AF_INET6, addr, ntopbuf,
sizeof(ntopbuf)) == NULL) {
warnmsg(LOG_INFO, __func__,
"an invalid address in RDNSS option"
" in RA from %s was ignored.",
inet_ntop(AF_INET6, &from.sin6_addr,
ntopbuf, sizeof(ntopbuf)));
addr++;
continue;
}
if (IN6_IS_ADDR_LINKLOCAL(addr))
/* XXX: % has to be escaped here */
l = snprintf(nsbuf, sizeof(nsbuf),
"%s%c%s", ntopbuf,
SCOPE_DELIMITER,
ifi->ifname);
else
l = snprintf(nsbuf, sizeof(nsbuf),
"%s", ntopbuf);
if (l < 0 || (size_t)l >= sizeof(nsbuf)) {
warnmsg(LOG_ERR, __func__,
"address copying error in "
"RDNSS option: %d.", l);
addr++;
continue;
}
warnmsg(LOG_DEBUG, __func__, "nsbuf = %s",
nsbuf);
newent_rao = 0;
rao = find_raopt(rai, ndo->nd_opt_type, nsbuf,
strlen(nsbuf));
if (rao == NULL) {
ELM_MALLOC(rao, break);
rao->rao_type = ndo->nd_opt_type;
rao->rao_len = strlen(nsbuf);
rao->rao_msg = strdup(nsbuf);
if (rao->rao_msg == NULL) {
warnmsg(LOG_ERR, __func__,
"strdup failed: %s",
strerror(errno));
free(rao);
addr++;
continue;
}
newent_rao = 1;
}
/* Set expiration timer */
memset(&rao->rao_expire, 0,
sizeof(rao->rao_expire));
memset(&lifetime, 0, sizeof(lifetime));
lifetime.tv_sec =
ntohl(rdnss->nd_opt_rdnss_lifetime);
TS_ADD(&now, &lifetime, &rao->rao_expire);
if (newent_rao)
TAILQ_INSERT_TAIL(&rai->rai_ra_opt,
rao, rao_next);
addr++;
}
break;
case ND_OPT_DNSSL:
dnssl = (struct nd_opt_dnssl *)raoptp;
/* Optlen sanity check (Section 5.3.1 in RFC 6106) */
if (dnssl->nd_opt_dnssl_len < 2) {
warnmsg(LOG_INFO, __func__,
"too short DNSSL option"
"in RA from %s was ignored.",
inet_ntop(AF_INET6, &from.sin6_addr,
ntopbuf, sizeof(ntopbuf)));
break;
}
/*
* Ensure NUL-termination in DNSSL in case of
* malformed field.
*/
p = (char *)RA_OPT_NEXT_HDR(raoptp);
*(p - 1) = '\0';
p = raoptp + sizeof(*dnssl);
while (1 < (len = dname_labeldec(dname, sizeof(dname),
p))) {
/* length == 1 means empty string */
warnmsg(LOG_DEBUG, __func__, "dname = %s",
dname);
newent_rao = 0;
rao = find_raopt(rai, ndo->nd_opt_type, dname,
strlen(dname));
if (rao == NULL) {
ELM_MALLOC(rao, break);
rao->rao_type = ndo->nd_opt_type;
rao->rao_len = strlen(dname);
rao->rao_msg = strdup(dname);
if (rao->rao_msg == NULL) {
warnmsg(LOG_ERR, __func__,
"strdup failed: %s",
strerror(errno));
free(rao);
addr++;
continue;
}
newent_rao = 1;
}
/* Set expiration timer */
memset(&rao->rao_expire, 0,
sizeof(rao->rao_expire));
memset(&lifetime, 0, sizeof(lifetime));
lifetime.tv_sec =
ntohl(dnssl->nd_opt_dnssl_lifetime);
TS_ADD(&now, &lifetime, &rao->rao_expire);
if (newent_rao)
TAILQ_INSERT_TAIL(&rai->rai_ra_opt,
rao, rao_next);
p += len;
}
break;
default:
/* nothing to do for other options */
break;
}
raoptp = (char *)RA_OPT_NEXT_HDR(raoptp);
}
if (newent_rai)
TAILQ_INSERT_TAIL(&ifi->ifi_rainfo, rai, rai_next);
ra_opt_handler(ifi);
ifi->racnt++;
switch (ifi->state) {
case IFS_IDLE: /* should be ignored */
case IFS_DELAY: /* right? */
break;
case IFS_PROBE:
ifi->state = IFS_IDLE;
ifi->probes = 0;
rtsol_timer_update(ifi);
break;
}
}
static char resstr_ns_prefix[] = "nameserver ";
static char resstr_sh_prefix[] = "search ";
static char resstr_nl[] = "\n";
static char resstr_sp[] = " ";
int
ra_opt_handler(struct ifinfo *ifi)
{
struct ra_opt *rao;
struct rainfo *rai;
struct script_msg *smp1, *smp2, *smp3;
struct timespec now;
struct script_msg_head_t sm_rdnss_head =
TAILQ_HEAD_INITIALIZER(sm_rdnss_head);
struct script_msg_head_t sm_dnssl_head =
TAILQ_HEAD_INITIALIZER(sm_dnssl_head);
int dcount, dlen;
dcount = 0;
dlen = strlen(resstr_sh_prefix) + strlen(resstr_nl);
clock_gettime(CLOCK_MONOTONIC_FAST, &now);
/*
* All options from multiple RAs with the same or different
* source addresses on a single interface will be gathered and
* handled, not overridden. [RFC 4861 6.3.4]
*/
TAILQ_FOREACH(rai, &ifi->ifi_rainfo, rai_next) {
TAILQ_FOREACH(rao, &rai->rai_ra_opt, rao_next) {
switch (rao->rao_type) {
case ND_OPT_RDNSS:
if (TS_CMP(&now, &rao->rao_expire, >)) {
warnmsg(LOG_INFO, __func__,
"expired rdnss entry: %s",
(char *)rao->rao_msg);
break;
}
ELM_MALLOC(smp1, continue);
ELM_MALLOC(smp2, goto free1);
ELM_MALLOC(smp3, goto free2);
smp1->sm_msg = resstr_ns_prefix;
TAILQ_INSERT_TAIL(&sm_rdnss_head, smp1,
sm_next);
smp2->sm_msg = rao->rao_msg;
TAILQ_INSERT_TAIL(&sm_rdnss_head, smp2,
sm_next);
smp3->sm_msg = resstr_nl;
TAILQ_INSERT_TAIL(&sm_rdnss_head, smp3,
sm_next);
ifi->ifi_rdnss = IFI_DNSOPT_STATE_RECEIVED;
break;
case ND_OPT_DNSSL:
if (TS_CMP(&now, &rao->rao_expire, >)) {
warnmsg(LOG_INFO, __func__,
"expired dnssl entry: %s",
(char *)rao->rao_msg);
break;
}
dcount++;
/* Check resolv.conf(5) restrictions. */
if (dcount > 6) {
warnmsg(LOG_INFO, __func__,
"dnssl entry exceeding maximum count (%d>6)"
": %s", dcount, (char *)rao->rao_msg);
break;
}
if (256 < dlen + strlen(rao->rao_msg) +
strlen(resstr_sp)) {
warnmsg(LOG_INFO, __func__,
"dnssl entry exceeding maximum length "
"(>256): %s", (char *)rao->rao_msg);
break;
}
ELM_MALLOC(smp1, continue);
ELM_MALLOC(smp2, goto free1);
if (TAILQ_EMPTY(&sm_dnssl_head)) {
ELM_MALLOC(smp3, goto free2);
smp3->sm_msg = resstr_sh_prefix;
TAILQ_INSERT_TAIL(&sm_dnssl_head, smp3,
sm_next);
}
smp1->sm_msg = rao->rao_msg;
TAILQ_INSERT_TAIL(&sm_dnssl_head, smp1,
sm_next);
smp2->sm_msg = resstr_sp;
TAILQ_INSERT_TAIL(&sm_dnssl_head, smp2,
sm_next);
dlen += strlen(rao->rao_msg) +
strlen(resstr_sp);
break;
ifi->ifi_dnssl = IFI_DNSOPT_STATE_RECEIVED;
default:
break;
}
continue;
free2:
free(smp2);
free1:
free(smp1);
}
/* Call the script for each information source. */
if (uflag)
ra_opt_rdnss_dispatch(ifi, rai, &sm_rdnss_head,
&sm_dnssl_head);
}
/* Call the script for each interface. */
if (!uflag)
ra_opt_rdnss_dispatch(ifi, NULL, &sm_rdnss_head,
&sm_dnssl_head);
return (0);
}
char *
make_rsid(const char *ifname, const char *origin, struct rainfo *rai)
{
char hbuf[NI_MAXHOST];
if (rai == NULL)
sprintf(rsid, "%s:%s", ifname, origin);
else {
if (!IN6_IS_ADDR_LINKLOCAL(&rai->rai_saddr.sin6_addr))
return (NULL);
if (getnameinfo((struct sockaddr *)&rai->rai_saddr,
rai->rai_saddr.sin6_len, hbuf, sizeof(hbuf), NULL, 0,
NI_NUMERICHOST) != 0)
return (NULL);
sprintf(rsid, "%s:%s:[%s]", ifname, origin, hbuf);
}
warnmsg(LOG_DEBUG, __func__, "rsid = [%s]", rsid);
return (rsid);
}
int
ra_opt_rdnss_dispatch(struct ifinfo *ifi,
struct rainfo *rai,
struct script_msg_head_t *sm_rdnss_head,
struct script_msg_head_t *sm_dnssl_head)
{
const char *r;
struct script_msg *smp1;
int error;
error = 0;
/* Add \n for DNSSL list. */
if (!TAILQ_EMPTY(sm_dnssl_head)) {
ELM_MALLOC(smp1, goto ra_opt_rdnss_freeit);
smp1->sm_msg = resstr_nl;
TAILQ_INSERT_TAIL(sm_dnssl_head, smp1, sm_next);
}
TAILQ_CONCAT(sm_rdnss_head, sm_dnssl_head, sm_next);
if (rai != NULL && uflag)
r = make_rsid(ifi->ifname, DNSINFO_ORIGIN_LABEL, rai);
else
r = make_rsid(ifi->ifname, DNSINFO_ORIGIN_LABEL, NULL);
if (r == NULL) {
warnmsg(LOG_ERR, __func__, "make_rsid() failed. "
"Script was not invoked.");
error = 1;
goto ra_opt_rdnss_freeit;
}
if (!TAILQ_EMPTY(sm_rdnss_head))
CALL_SCRIPT(RESADD, sm_rdnss_head);
else if (ifi->ifi_rdnss == IFI_DNSOPT_STATE_RECEIVED ||
ifi->ifi_dnssl == IFI_DNSOPT_STATE_RECEIVED) {
CALL_SCRIPT(RESDEL, NULL);
ifi->ifi_rdnss = IFI_DNSOPT_STATE_NOINFO;
ifi->ifi_dnssl = IFI_DNSOPT_STATE_NOINFO;
}
ra_opt_rdnss_freeit:
/* Clear script message queue. */
if (!TAILQ_EMPTY(sm_rdnss_head)) {
while ((smp1 = TAILQ_FIRST(sm_rdnss_head)) != NULL) {
TAILQ_REMOVE(sm_rdnss_head, smp1, sm_next);
free(smp1);
}
}
if (!TAILQ_EMPTY(sm_dnssl_head)) {
while ((smp1 = TAILQ_FIRST(sm_dnssl_head)) != NULL) {
TAILQ_REMOVE(sm_dnssl_head, smp1, sm_next);
free(smp1);
}
}
return (error);
}
static struct ra_opt *
find_raopt(struct rainfo *rai, int type, void *msg, size_t len)
{
struct ra_opt *rao;
TAILQ_FOREACH(rao, &rai->rai_ra_opt, rao_next) {
if (rao->rao_type == type &&
rao->rao_len == strlen(msg) &&
memcmp(rao->rao_msg, msg, len) == 0)
break;
}
return (rao);
}
static void
call_script(const int argc, const char *const argv[],
struct script_msg_head_t *sm_head)
{
const char *scriptpath;
int fd[2];
int error;
pid_t pid, wpid;
if ((scriptpath = argv[0]) == NULL)
return;
fd[0] = fd[1] = -1;
if (sm_head != NULL && !TAILQ_EMPTY(sm_head)) {
error = pipe(fd);
if (error) {
warnmsg(LOG_ERR, __func__,
"failed to create a pipe: %s", strerror(errno));
return;
}
}
/* launch the script */
pid = fork();
if (pid < 0) {
warnmsg(LOG_ERR, __func__,
"failed to fork: %s", strerror(errno));
return;
} else if (pid) { /* parent */
int wstatus;
if (fd[0] != -1) { /* Send message to the child if any. */
ssize_t len;
struct script_msg *smp;
close(fd[0]);
TAILQ_FOREACH(smp, sm_head, sm_next) {
len = strlen(smp->sm_msg);
warnmsg(LOG_DEBUG, __func__,
"write to child = %s(%zd)",
smp->sm_msg, len);
if (write(fd[1], smp->sm_msg, len) != len) {
warnmsg(LOG_ERR, __func__,
"write to child failed: %s",
strerror(errno));
break;
}
}
close(fd[1]);
}
do {
wpid = wait(&wstatus);
} while (wpid != pid && wpid > 0);
if (wpid < 0)
warnmsg(LOG_ERR, __func__,
"wait: %s", strerror(errno));
else
warnmsg(LOG_DEBUG, __func__,
"script \"%s\" terminated", scriptpath);
} else { /* child */
int nullfd;
char **_argv;
if (safefile(scriptpath)) {
warnmsg(LOG_ERR, __func__,
"script \"%s\" cannot be executed safely",
scriptpath);
exit(1);
}
nullfd = open("/dev/null", O_RDWR);
if (nullfd < 0) {
warnmsg(LOG_ERR, __func__,
"open /dev/null: %s", strerror(errno));
exit(1);
}
if (fd[0] != -1) { /* Receive message from STDIN if any. */
close(fd[1]);
if (fd[0] != STDIN_FILENO) {
/* Connect a pipe read-end to child's STDIN. */
if (dup2(fd[0], STDIN_FILENO) != STDIN_FILENO) {
warnmsg(LOG_ERR, __func__,
"dup2 STDIN: %s", strerror(errno));
exit(1);
}
close(fd[0]);
}
} else
dup2(nullfd, STDIN_FILENO);
dup2(nullfd, STDOUT_FILENO);
dup2(nullfd, STDERR_FILENO);
if (nullfd > STDERR_FILENO)
close(nullfd);
_argv = malloc(sizeof(*_argv) * argc);
if (_argv == NULL) {
warnmsg(LOG_ERR, __func__,
"malloc: %s", strerror(errno));
exit(1);
}
memcpy(_argv, argv, (size_t)argc);
execv(scriptpath, (char *const *)_argv);
warnmsg(LOG_ERR, __func__, "child: exec failed: %s",
strerror(errno));
exit(1);
}
return;
}
static int
safefile(const char *path)
{
struct stat s;
uid_t myuid;
/* no setuid */
if (getuid() != geteuid()) {
warnmsg(LOG_NOTICE, __func__,
"setuid'ed execution not allowed\n");
return (-1);
}
if (lstat(path, &s) != 0) {
warnmsg(LOG_NOTICE, __func__, "lstat failed: %s",
strerror(errno));
return (-1);
}
/* the file must be owned by the running uid */
myuid = getuid();
if (s.st_uid != myuid) {
warnmsg(LOG_NOTICE, __func__,
"%s has invalid owner uid\n", path);
return (-1);
}
switch (s.st_mode & S_IFMT) {
case S_IFREG:
break;
default:
warnmsg(LOG_NOTICE, __func__,
"%s is an invalid file type 0x%o\n",
path, (s.st_mode & S_IFMT));
return (-1);
}
return (0);
}
/* Decode domain name label encoding in RFC 1035 Section 3.1 */
static size_t
dname_labeldec(char *dst, size_t dlen, const char *src)
{
size_t len;
const char *src_origin;
const char *src_last;
const char *dst_origin;
src_origin = src;
src_last = strchr(src, '\0');
dst_origin = dst;
memset(dst, '\0', dlen);
while (src && (len = (uint8_t)(*src++) & 0x3f) &&
(src + len) <= src_last &&
(dst - dst_origin < (ssize_t)dlen)) {
if (dst != dst_origin)
*dst++ = '.';
warnmsg(LOG_DEBUG, __func__, "labellen = %zd", len);
memcpy(dst, src, len);
src += len;
dst += len;
}
*dst = '\0';
/*
* XXX validate that domain name only contains valid characters
* for two reasons: 1) correctness, 2) we do not want to pass
* possible malicious, unescaped characters like `` to a script
* or program that could be exploited that way.
*/
return (src - src_origin);
}
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