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|
// SPDX-License-Identifier: GPL-2.0-or-later
/*
* PIM for Quagga
* Copyright (C) 2008 Everton da Silva Marques
*/
#include <zebra.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/igmp.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <netdb.h>
#include <errno.h>
#include "log.h"
#include "privs.h"
#include "if.h"
#include "vrf.h"
#include "sockopt.h"
#include "lib_errors.h"
#include "network.h"
#include "pimd.h"
#include "pim_instance.h"
#include "pim_mroute.h"
#include "pim_iface.h"
#include "pim_sock.h"
#include "pim_str.h"
#if PIM_IPV == 4
#define setsockopt_iptos setsockopt_ipv4_tos
#define setsockopt_multicast_loop setsockopt_ipv4_multicast_loop
#else
#define setsockopt_iptos setsockopt_ipv6_tclass
#define setsockopt_multicast_loop setsockopt_ipv6_multicast_loop
#endif
int pim_socket_raw(int protocol)
{
int fd;
frr_with_privs(&pimd_privs) {
fd = socket(PIM_AF, SOCK_RAW, protocol);
}
if (fd < 0) {
zlog_warn("Could not create raw socket: errno=%d: %s", errno,
safe_strerror(errno));
return PIM_SOCK_ERR_SOCKET;
}
return fd;
}
void pim_socket_ip_hdr(int fd)
{
frr_with_privs(&pimd_privs) {
#if PIM_IPV == 4
const int on = 1;
if (setsockopt(fd, IPPROTO_IP, IP_HDRINCL, &on, sizeof(on)))
zlog_err("%s: Could not turn on IP_HDRINCL option: %m",
__func__);
#endif
}
}
/*
* Given a socket and a interface,
* Bind that socket to that interface
*/
int pim_socket_bind(int fd, struct interface *ifp)
{
int ret = 0;
#ifdef SO_BINDTODEVICE
frr_with_privs(&pimd_privs) {
ret = setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, ifp->name,
strlen(ifp->name));
}
#endif
return ret;
}
#if PIM_IPV == 4
static inline int pim_setsockopt(int protocol, int fd, struct interface *ifp)
{
int one = 1;
int ttl = 1;
#if defined(HAVE_IP_PKTINFO)
/* Linux and Solaris IP_PKTINFO */
if (setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one)))
zlog_warn("Could not set PKTINFO on socket fd=%d: %m", fd);
#elif defined(HAVE_IP_RECVDSTADDR)
/* BSD IP_RECVDSTADDR */
if (setsockopt(fd, IPPROTO_IP, IP_RECVDSTADDR, &one, sizeof(one)))
zlog_warn("Could not set IP_RECVDSTADDR on socket fd=%d: %m",
fd);
#else
flog_err(
EC_LIB_DEVELOPMENT,
"Missing IP_PKTINFO and IP_RECVDSTADDR: unable to get dst addr from recvmsg()");
close(fd);
return PIM_SOCK_ERR_DSTADDR;
#endif
/* Set router alert (RFC 2113) for all IGMP messages (RFC
* 3376 4. Message Formats)*/
if (protocol == IPPROTO_IGMP) {
uint8_t ra[4];
ra[0] = 148;
ra[1] = 4;
ra[2] = 0;
ra[3] = 0;
if (setsockopt(fd, IPPROTO_IP, IP_OPTIONS, ra, 4)) {
zlog_warn(
"Could not set Router Alert Option on socket fd=%d: %m",
fd);
close(fd);
return PIM_SOCK_ERR_RA;
}
}
if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl))) {
zlog_warn("Could not set multicast TTL=%d on socket fd=%d: %m",
ttl, fd);
close(fd);
return PIM_SOCK_ERR_TTL;
}
if (setsockopt_ipv4_multicast_if(fd, PIMADDR_ANY, ifp->ifindex)) {
zlog_warn(
"Could not set Outgoing Interface Option on socket fd=%d: %m",
fd);
close(fd);
return PIM_SOCK_ERR_IFACE;
}
return 0;
}
#else /* PIM_IPV != 4 */
static inline int pim_setsockopt(int protocol, int fd, struct interface *ifp)
{
int ttl = 1;
struct ipv6_mreq mreq = {};
setsockopt_ipv6_pktinfo(fd, 1);
setsockopt_ipv6_multicast_hops(fd, ttl);
mreq.ipv6mr_interface = ifp->ifindex;
if (setsockopt(fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &mreq,
sizeof(mreq))) {
zlog_warn(
"Could not set Outgoing Interface Option on socket fd=%d: %m",
fd);
close(fd);
return PIM_SOCK_ERR_IFACE;
}
return 0;
}
#endif
int pim_reg_sock(void)
{
int fd;
long flags;
frr_with_privs (&pimd_privs) {
fd = socket(PIM_AF, SOCK_RAW, PIM_PROTO_REG);
}
if (fd < 0) {
zlog_warn("Could not create raw socket: errno=%d: %s", errno,
safe_strerror(errno));
return PIM_SOCK_ERR_SOCKET;
}
if (sockopt_reuseaddr(fd)) {
close(fd);
return PIM_SOCK_ERR_REUSE;
}
flags = fcntl(fd, F_GETFL, 0);
if (flags < 0) {
zlog_warn(
"Could not get fcntl(F_GETFL,O_NONBLOCK) on socket fd=%d: errno=%d: %s",
fd, errno, safe_strerror(errno));
close(fd);
return PIM_SOCK_ERR_NONBLOCK_GETFL;
}
if (fcntl(fd, F_SETFL, flags | O_NONBLOCK)) {
zlog_warn(
"Could not set fcntl(F_SETFL,O_NONBLOCK) on socket fd=%d: errno=%d: %s",
fd, errno, safe_strerror(errno));
close(fd);
return PIM_SOCK_ERR_NONBLOCK_SETFL;
}
return fd;
}
int pim_socket_mcast(int protocol, pim_addr ifaddr, struct interface *ifp,
uint8_t loop)
{
int fd;
int ret;
fd = pim_socket_raw(protocol);
if (fd < 0) {
zlog_warn("Could not create multicast socket: errno=%d: %s",
errno, safe_strerror(errno));
return PIM_SOCK_ERR_SOCKET;
}
/* XXX: if SO_BINDTODEVICE isn't available, use IP_PKTINFO / IP_RECVIF
* to emulate behaviour? Or change to only use 1 socket for all
* interfaces? */
ret = pim_socket_bind(fd, ifp);
if (ret) {
close(fd);
zlog_warn("Could not set fd: %d for interface: %s to device",
fd, ifp->name);
return PIM_SOCK_ERR_BIND;
}
set_nonblocking(fd);
sockopt_reuseaddr(fd);
setsockopt_so_recvbuf(fd, 8 * 1024 * 1024);
ret = pim_setsockopt(protocol, fd, ifp);
if (ret) {
zlog_warn("pim_setsockopt failed for interface: %s to device ",
ifp->name);
return ret;
}
/* leftover common sockopts */
if (setsockopt_multicast_loop(fd, loop)) {
zlog_warn(
"Could not %s Multicast Loopback Option on socket fd=%d: %m",
loop ? "enable" : "disable", fd);
close(fd);
return PIM_SOCK_ERR_LOOP;
}
/* Set Tx socket DSCP byte */
if (setsockopt_iptos(fd, IPTOS_PREC_INTERNETCONTROL))
zlog_warn("can't set sockopt IP[V6]_TOS to socket %d: %m", fd);
return fd;
}
int pim_socket_join(int fd, pim_addr group, pim_addr ifaddr, ifindex_t ifindex,
struct pim_interface *pim_ifp)
{
int ret;
#if PIM_IPV == 4
ret = setsockopt_ipv4_multicast(fd, IP_ADD_MEMBERSHIP, ifaddr,
group.s_addr, ifindex);
#else
struct ipv6_mreq opt;
memcpy(&opt.ipv6mr_multiaddr, &group, 16);
opt.ipv6mr_interface = ifindex;
ret = setsockopt(fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, &opt, sizeof(opt));
#endif
pim_ifp->igmp_ifstat_joins_sent++;
if (ret) {
flog_err(
EC_LIB_SOCKET,
"Failure socket joining fd=%d group %pPAs on interface address %pPAs: %m",
fd, &group, &ifaddr);
pim_ifp->igmp_ifstat_joins_failed++;
return ret;
}
if (PIM_DEBUG_TRACE)
zlog_debug(
"Socket fd=%d joined group %pPAs on interface address %pPAs",
fd, &group, &ifaddr);
return ret;
}
int pim_socket_leave(int fd, pim_addr group, pim_addr ifaddr, ifindex_t ifindex,
struct pim_interface *pim_ifp)
{
int ret;
#if PIM_IPV == 4
ret = setsockopt_ipv4_multicast(fd, IP_DROP_MEMBERSHIP, ifaddr,
group.s_addr, ifindex);
#else
struct ipv6_mreq opt;
memcpy(&opt.ipv6mr_multiaddr, &group, 16);
opt.ipv6mr_interface = ifindex;
ret = setsockopt(fd, IPPROTO_IPV6, IPV6_LEAVE_GROUP, &opt, sizeof(opt));
#endif
if (ret) {
flog_err(EC_LIB_SOCKET,
"Failure socket leaving fd=%d group %pPAs on interface address %pPAs: %m",
fd, &group, &ifaddr);
pim_ifp->igmp_ifstat_joins_failed++;
return ret;
}
if (PIM_DEBUG_TRACE)
zlog_debug("Socket fd=%d left group %pPAs on interface address %pPAs",
fd, &group, &ifaddr);
return ret;
}
#if PIM_IPV == 4
static void cmsg_getdstaddr(struct msghdr *mh, struct sockaddr_storage *dst,
ifindex_t *ifindex)
{
struct cmsghdr *cmsg;
struct sockaddr_in *dst4 = (struct sockaddr_in *)dst;
for (cmsg = CMSG_FIRSTHDR(mh); cmsg != NULL;
cmsg = CMSG_NXTHDR(mh, cmsg)) {
#ifdef HAVE_IP_PKTINFO
if ((cmsg->cmsg_level == IPPROTO_IP) &&
(cmsg->cmsg_type == IP_PKTINFO)) {
struct in_pktinfo *i;
i = (struct in_pktinfo *)CMSG_DATA(cmsg);
if (dst4)
dst4->sin_addr = i->ipi_addr;
if (ifindex)
*ifindex = i->ipi_ifindex;
break;
}
#endif
#ifdef HAVE_IP_RECVDSTADDR
if ((cmsg->cmsg_level == IPPROTO_IP) &&
(cmsg->cmsg_type == IP_RECVDSTADDR)) {
struct in_addr *i = (struct in_addr *)CMSG_DATA(cmsg);
if (dst4)
dst4->sin_addr = *i;
break;
}
#endif
#if defined(HAVE_IP_RECVIF) && defined(CMSG_IFINDEX)
if (cmsg->cmsg_type == IP_RECVIF)
if (ifindex)
*ifindex = CMSG_IFINDEX(cmsg);
#endif
}
}
#else /* PIM_IPV != 4 */
static void cmsg_getdstaddr(struct msghdr *mh, struct sockaddr_storage *dst,
ifindex_t *ifindex)
{
struct cmsghdr *cmsg;
struct sockaddr_in6 *dst6 = (struct sockaddr_in6 *)dst;
for (cmsg = CMSG_FIRSTHDR(mh); cmsg != NULL;
cmsg = CMSG_NXTHDR(mh, cmsg)) {
if ((cmsg->cmsg_level == IPPROTO_IPV6) &&
(cmsg->cmsg_type == IPV6_PKTINFO)) {
struct in6_pktinfo *i;
i = (struct in6_pktinfo *)CMSG_DATA(cmsg);
if (dst6)
dst6->sin6_addr = i->ipi6_addr;
if (ifindex)
*ifindex = i->ipi6_ifindex;
break;
}
}
}
#endif /* PIM_IPV != 4 */
int pim_socket_recvfromto(int fd, uint8_t *buf, size_t len,
struct sockaddr_storage *from, socklen_t *fromlen,
struct sockaddr_storage *to, socklen_t *tolen,
ifindex_t *ifindex)
{
struct msghdr msgh;
struct iovec iov;
char cbuf[1000];
int err;
/*
* IP_PKTINFO / IP_RECVDSTADDR don't yield sin_port.
* Use getsockname() to get sin_port.
*/
if (to) {
socklen_t to_len = sizeof(*to);
pim_socket_getsockname(fd, (struct sockaddr *)to, &to_len);
if (tolen)
*tolen = sizeof(*to);
}
memset(&msgh, 0, sizeof(msgh));
iov.iov_base = buf;
iov.iov_len = len;
msgh.msg_control = cbuf;
msgh.msg_controllen = sizeof(cbuf);
msgh.msg_name = from;
msgh.msg_namelen = fromlen ? *fromlen : 0;
msgh.msg_iov = &iov;
msgh.msg_iovlen = 1;
msgh.msg_flags = 0;
err = recvmsg(fd, &msgh, 0);
if (err < 0)
return err;
if (fromlen)
*fromlen = msgh.msg_namelen;
cmsg_getdstaddr(&msgh, to, ifindex);
return err; /* len */
}
int pim_socket_getsockname(int fd, struct sockaddr *name, socklen_t *namelen)
{
if (getsockname(fd, name, namelen)) {
int e = errno;
zlog_warn(
"Could not get Socket Name for socket fd=%d: errno=%d: %s",
fd, errno, safe_strerror(errno));
errno = e;
return PIM_SOCK_ERR_NAME;
}
return PIM_SOCK_ERR_NONE;
}
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