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freebsd-skq/usr.sbin/rtsold/rtsol.c
Pedro F. Giffuni 8a16b7a18f General further adoption of SPDX licensing ID tags. 
Mainly focus on files that use BSD 3-Clause license.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

Special thanks to Wind River for providing access to "The Duke of
Highlander" tool: an older (2014) run over FreeBSD tree was useful as a
starting point.
2017-11-20 19:49:47 +00:00

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/* $KAME: rtsol.c,v 1.27 2003/10/05 00:09:36 itojun Exp $ */
/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* 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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