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freebsd-skq/usr.sbin/rtsold/rtsol.c
Mark Johnston 04e9edb544 Capsicumize rtsol(8) and rtsold(8). 
These programs parse ND6 Router Advertisement messages; rtsold(8) has
required an SA, SA-14:20.rtsold, for a bug in this code.  Thus, they
are good candidates for sandboxing.

The approach taken is to run the main executable in capability mode
and use Casper services to provide functionality that cannot be
implemented within the sandbox.  In particular, several custom services
were required.

- A Casper service is used to send Router Solicitation messages on a
  raw ICMP6 socket.  Initially I took the approach of creating a
  socket for each interface upon startup, and connect(2)ing it to
  the all-routers multicast group for the interface.  This permits
  the use of sendmsg(2) in capability mode, but only works if the
  interface's link is up when rtsol(d) starts.  So, instead, the
  rtsold.sendmsg service is used to transmit RS messages on behalf
  of the main process.  One could alternately define a service
  which simply creates and connects a socket for each destination
  address, and returns the socket to the sandboxed process.  However,
  to implement rtsold's -m option we also need to read the ND6 default
  router list, and this cannot be done in capability mode.
- rtsold may execute resolvconf(8) in response to RDNSS and DNSSL
  options in received RA messages.  A Casper service is used to
  fork and exec resolvconf(8), and to reap the child process.
- A service is used to determine whether a given interface's
  link-local address is useable (i.e., not duplicated or undergoing
  DAD).  This information is supplied by getifaddrs(3), which reads
  a sysctl not available in capability mode.  The SIOCGIFCONF socket
  ioctl provides equivalent information and can be used in capability
  mode, but I decided against it for now because of some limitations
  of that interface.

In addition to these new services, cap_syslog(3) is used to send
messages to syslogd.

Reviewed by:	oshogbo
Tested by:	bz (previous versions)
MFC after:	2 months
Sponsored by:	The FreeBSD Foundation
Differential Revision:	https://reviews.freebsd.org/D17572
2019-01-05 16:05:39 +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/capsicum.h>
#include <sys/queue.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/uio.h>
#include <sys/wait.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 <capsicum_helpers.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 char rsid[IFNAMSIZ + 1 + sizeof(DNSINFO_ORIGIN_LABEL) + 1 + NI_MAXHOST];
struct ifinfo_head_t ifinfo_head = TAILQ_HEAD_INITIALIZER(ifinfo_head);
static void call_script(const char *const *, struct script_msg_head_t *);
static size_t dname_labeldec(char *, size_t, 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(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
recvsockopen(void)
{
struct icmp6_filter filt;
cap_rights_t rights;
int on, sock;
if ((sock = socket(AF_INET6, SOCK_RAW, IPPROTO_ICMPV6)) < 0) {
warnmsg(LOG_ERR, __func__, "socket: %s", strerror(errno));
goto fail;
}
/* Provide info about the receiving interface. */
on = 1;
if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVPKTINFO, &on,
sizeof(on)) < 0) {
warnmsg(LOG_ERR, __func__, "setsockopt(IPV6_RECVPKTINFO): %s",
strerror(errno));
goto fail;
}
/* Include the hop limit from the received header. */
on = 1;
if (setsockopt(sock, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &on,
sizeof(on)) < 0) {
warnmsg(LOG_ERR, __func__, "setsockopt(IPV6_RECVHOPLIMIT): %s",
strerror(errno));
goto fail;
}
/* Filter out everything except for Router Advertisements. */
ICMP6_FILTER_SETBLOCKALL(&filt);
ICMP6_FILTER_SETPASS(ND_ROUTER_ADVERT, &filt);
if (setsockopt(sock, IPPROTO_ICMPV6, ICMP6_FILTER, &filt,
sizeof(filt)) == -1) {
warnmsg(LOG_ERR, __func__, "setsockopt(ICMP6_FILTER): %s",
strerror(errno));
goto fail;
}
cap_rights_init(&rights, CAP_EVENT, CAP_RECV);
if (caph_rights_limit(sock, &rights) < 0) {
warnmsg(LOG_ERR, __func__, "caph_rights_limit(): %s",
strerror(errno));
goto fail;
}
return (sock);
fail:
if (sock >= 0)
(void)close(sock);
return (-1);
}
void
rtsol_input(int sock)
{
uint8_t cmsg[CMSG_SPACE(sizeof(struct in6_pktinfo)) +
CMSG_SPACE(sizeof(int))];
struct iovec iov;
struct msghdr hdr;
struct sockaddr_in6 from;
char answer[1500], 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 *p, *raoptp;
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 lifetime, now;
int newent_rai, newent_rao;
memset(&hdr, 0, sizeof(hdr));
hdr.msg_iov = &iov;
hdr.msg_iovlen = 1;
hdr.msg_name = &from;
hdr.msg_namelen = sizeof(from);
hdr.msg_control = cmsg;
hdr.msg_controllen = sizeof(cmsg);
iov.iov_base = (caddr_t)answer;
iov.iov_len = sizeof(answer);
if ((msglen = recvmsg(sock, &hdr, 0)) < 0) {
warnmsg(LOG_ERR, __func__, "recvmsg: %s", strerror(errno));
return;
}
/* Extract control message info. */
for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&hdr); cm != NULL;
cm = (struct cmsghdr *)CMSG_NXTHDR(&hdr, 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 *)iov.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);
ifi->ifi_dnssl = IFI_DNSOPT_STATE_RECEIVED;
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)
{
struct script_msg *smp1;
const char *r;
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);
r = make_rsid(ifi->ifname, DNSINFO_ORIGIN_LABEL, uflag ? rai : 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 char *const argv[], struct script_msg_head_t *sm_head)
{
struct script_msg *smp;
ssize_t len;
int status, wfd;
if (argv[0] == NULL)
return;
wfd = cap_script_run(capscript, argv);
if (wfd == -1) {
warnmsg(LOG_ERR, __func__,
"failed to run %s: %s", argv[0], strerror(errno));
return;
}
if (sm_head != NULL) {
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(wfd, smp->sm_msg, len) != len) {
warnmsg(LOG_ERR, __func__,
"write to child failed: %s",
strerror(errno));
break;
}
}
}
(void)close(wfd);
if (cap_script_wait(capscript, &status) != 0)
warnmsg(LOG_ERR, __func__, "wait(): %s", strerror(errno));
else
warnmsg(LOG_DEBUG, __func__, "script \"%s\" status %d",
argv[0], status);
}
/* 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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