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-rw-r--r--bfdd/bfd_packet.c1738
1 files changed, 1738 insertions, 0 deletions
diff --git a/bfdd/bfd_packet.c b/bfdd/bfd_packet.c
new file mode 100644
index 0000000..603d220
--- /dev/null
+++ b/bfdd/bfd_packet.c
@@ -0,0 +1,1738 @@
+/*********************************************************************
+ * Copyright 2017 Cumulus Networks, Inc. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation; either version 2 of the License, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; see the file COPYING; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * bfd_packet.c: implements the BFD protocol packet handling.
+ *
+ * Authors
+ * -------
+ * Shrijeet Mukherjee [shm@cumulusnetworks.com]
+ * Kanna Rajagopal [kanna@cumulusnetworks.com]
+ * Radhika Mahankali [Radhika@cumulusnetworks.com]
+ */
+
+#include <zebra.h>
+
+#ifdef BFD_LINUX
+#include <linux/if_packet.h>
+#endif /* BFD_LINUX */
+
+#include <netinet/if_ether.h>
+#include <netinet/udp.h>
+
+#include "lib/sockopt.h"
+#include "lib/checksum.h"
+#include "lib/network.h"
+
+#include "bfd.h"
+
+/*
+ * Prototypes
+ */
+static int ptm_bfd_process_echo_pkt(struct bfd_vrf_global *bvrf, int s);
+int _ptm_bfd_send(struct bfd_session *bs, uint16_t *port, const void *data,
+ size_t datalen);
+
+static void bfd_sd_reschedule(struct bfd_vrf_global *bvrf, int sd);
+ssize_t bfd_recv_ipv4(int sd, uint8_t *msgbuf, size_t msgbuflen, uint8_t *ttl,
+ ifindex_t *ifindex, struct sockaddr_any *local,
+ struct sockaddr_any *peer);
+ssize_t bfd_recv_ipv6(int sd, uint8_t *msgbuf, size_t msgbuflen, uint8_t *ttl,
+ ifindex_t *ifindex, struct sockaddr_any *local,
+ struct sockaddr_any *peer);
+int bp_udp_send(int sd, uint8_t ttl, uint8_t *data, size_t datalen,
+ struct sockaddr *to, socklen_t tolen);
+int bp_bfd_echo_in(struct bfd_vrf_global *bvrf, int sd, uint8_t *ttl,
+ uint32_t *my_discr, uint64_t *my_rtt);
+#ifdef BFD_LINUX
+ssize_t bfd_recv_ipv4_fp(int sd, uint8_t *msgbuf, size_t msgbuflen,
+ uint8_t *ttl, ifindex_t *ifindex,
+ struct sockaddr_any *local, struct sockaddr_any *peer);
+void bfd_peer_mac_set(int sd, struct bfd_session *bfd,
+ struct sockaddr_any *peer, struct interface *ifp);
+int bp_udp_send_fp(int sd, uint8_t *data, size_t datalen,
+ struct bfd_session *bfd);
+ssize_t bfd_recv_fp_echo(int sd, uint8_t *msgbuf, size_t msgbuflen,
+ uint8_t *ttl, ifindex_t *ifindex,
+ struct sockaddr_any *local, struct sockaddr_any *peer);
+#endif
+
+/* socket related prototypes */
+static void bp_set_ipopts(int sd);
+static void bp_bind_ip(int sd, uint16_t port);
+static void bp_set_ipv6opts(int sd);
+static void bp_bind_ipv6(int sd, uint16_t port);
+
+
+/*
+ * Functions
+ */
+int _ptm_bfd_send(struct bfd_session *bs, uint16_t *port, const void *data,
+ size_t datalen)
+{
+ struct sockaddr *sa;
+ struct sockaddr_in sin;
+ struct sockaddr_in6 sin6;
+ socklen_t slen;
+ ssize_t rv;
+ int sd = -1;
+
+ if (CHECK_FLAG(bs->flags, BFD_SESS_FLAG_IPV6)) {
+ memset(&sin6, 0, sizeof(sin6));
+ sin6.sin6_family = AF_INET6;
+ memcpy(&sin6.sin6_addr, &bs->key.peer, sizeof(sin6.sin6_addr));
+ if (bs->ifp && IN6_IS_ADDR_LINKLOCAL(&sin6.sin6_addr))
+ sin6.sin6_scope_id = bs->ifp->ifindex;
+
+ sin6.sin6_port =
+ (port) ? *port
+ : (CHECK_FLAG(bs->flags, BFD_SESS_FLAG_MH))
+ ? htons(BFD_DEF_MHOP_DEST_PORT)
+ : htons(BFD_DEFDESTPORT);
+
+ sd = bs->sock;
+ sa = (struct sockaddr *)&sin6;
+ slen = sizeof(sin6);
+ } else {
+ memset(&sin, 0, sizeof(sin));
+ sin.sin_family = AF_INET;
+ memcpy(&sin.sin_addr, &bs->key.peer, sizeof(sin.sin_addr));
+ sin.sin_port =
+ (port) ? *port
+ : (CHECK_FLAG(bs->flags, BFD_SESS_FLAG_MH))
+ ? htons(BFD_DEF_MHOP_DEST_PORT)
+ : htons(BFD_DEFDESTPORT);
+
+ sd = bs->sock;
+ sa = (struct sockaddr *)&sin;
+ slen = sizeof(sin);
+ }
+
+#ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
+ sa->sa_len = slen;
+#endif /* HAVE_STRUCT_SOCKADDR_SA_LEN */
+ rv = sendto(sd, data, datalen, 0, sa, slen);
+ if (rv <= 0) {
+ if (bglobal.debug_network)
+ zlog_debug("packet-send: send failure: %s",
+ strerror(errno));
+ return -1;
+ }
+ if (rv < (ssize_t)datalen) {
+ if (bglobal.debug_network)
+ zlog_debug("packet-send: send partial: %s",
+ strerror(errno));
+ }
+
+ return 0;
+}
+
+#ifdef BFD_LINUX
+/*
+ * Compute the UDP checksum.
+ *
+ * Checksum is not set in the packet, just computed.
+ *
+ * pkt
+ * Packet, fully filled out except for checksum field.
+ *
+ * pktsize
+ * sizeof(*pkt)
+ *
+ * ip
+ * IP address that pkt will be transmitted from and too.
+ *
+ * Returns:
+ * Checksum in network byte order.
+ */
+static uint16_t bfd_pkt_checksum(struct udphdr *pkt, size_t pktsize,
+ struct in6_addr *ip, sa_family_t family)
+{
+ uint16_t chksum;
+
+ pkt->check = 0;
+
+ if (family == AF_INET6) {
+ struct ipv6_ph ph = {};
+
+ memcpy(&ph.src, ip, sizeof(ph.src));
+ memcpy(&ph.dst, ip, sizeof(ph.dst));
+ ph.ulpl = htons(pktsize);
+ ph.next_hdr = IPPROTO_UDP;
+ chksum = in_cksum_with_ph6(&ph, pkt, pktsize);
+ } else {
+ struct ipv4_ph ph = {};
+
+ memcpy(&ph.src, ip, sizeof(ph.src));
+ memcpy(&ph.dst, ip, sizeof(ph.dst));
+ ph.proto = IPPROTO_UDP;
+ ph.len = htons(pktsize);
+ chksum = in_cksum_with_ph4(&ph, pkt, pktsize);
+ }
+
+ return chksum;
+}
+
+/*
+ * This routine creates the entire ECHO packet so that it will be looped
+ * in the forwarding plane of the peer router instead of going up the
+ * stack in BFD to be looped. If we haven't learned the peers MAC yet
+ * no echo is sent.
+ *
+ * echo packet with src/dst IP equal to local IP
+ * dest MAC as peer's MAC
+ *
+ * currently support ipv4
+ */
+void ptm_bfd_echo_fp_snd(struct bfd_session *bfd)
+{
+ int sd;
+ struct bfd_vrf_global *bvrf = bfd_vrf_look_by_session(bfd);
+ int total_len = 0;
+ struct ethhdr *eth;
+ struct udphdr *uh;
+ struct iphdr *iph;
+ struct bfd_echo_pkt *beph;
+ static char sendbuff[100];
+ struct timeval time_sent;
+
+ if (!bvrf)
+ return;
+ if (!CHECK_FLAG(bfd->flags, BFD_SESS_FLAG_MAC_SET))
+ return;
+ if (!CHECK_FLAG(bfd->flags, BFD_SESS_FLAG_ECHO_ACTIVE))
+ SET_FLAG(bfd->flags, BFD_SESS_FLAG_ECHO_ACTIVE);
+
+ memset(sendbuff, 0, sizeof(sendbuff));
+
+ /* add eth hdr */
+ eth = (struct ethhdr *)(sendbuff);
+ memcpy(eth->h_source, bfd->ifp->hw_addr, sizeof(eth->h_source));
+ memcpy(eth->h_dest, bfd->peer_hw_addr, sizeof(eth->h_dest));
+
+ total_len += sizeof(struct ethhdr);
+
+ sd = bvrf->bg_echo;
+ eth->h_proto = htons(ETH_P_IP);
+
+ /* add ip hdr */
+ iph = (struct iphdr *)(sendbuff + sizeof(struct ethhdr));
+
+ iph->ihl = sizeof(struct ip) >> 2;
+ iph->version = IPVERSION;
+ iph->tos = IPTOS_PREC_INTERNETCONTROL;
+ iph->id = (uint16_t)frr_weak_random();
+ iph->ttl = BFD_TTL_VAL;
+ iph->protocol = IPPROTO_UDP;
+ memcpy(&iph->saddr, &bfd->local_address.sa_sin.sin_addr,
+ sizeof(bfd->local_address.sa_sin.sin_addr));
+ memcpy(&iph->daddr, &bfd->local_address.sa_sin.sin_addr,
+ sizeof(bfd->local_address.sa_sin.sin_addr));
+ total_len += sizeof(struct iphdr);
+
+ /* add udp hdr */
+ uh = (struct udphdr *)(sendbuff + sizeof(struct iphdr) +
+ sizeof(struct ethhdr));
+ uh->source = htons(BFD_DEF_ECHO_PORT);
+ uh->dest = htons(BFD_DEF_ECHO_PORT);
+
+ total_len += sizeof(struct udphdr);
+
+ /* add bfd echo */
+ beph = (struct bfd_echo_pkt *)(sendbuff + sizeof(struct udphdr) +
+ sizeof(struct iphdr) +
+ sizeof(struct ethhdr));
+
+ beph->ver = BFD_ECHO_VERSION;
+ beph->len = BFD_ECHO_PKT_LEN;
+ beph->my_discr = htonl(bfd->discrs.my_discr);
+
+ /* RTT calculation: add starting time in packet */
+ monotime(&time_sent);
+ beph->time_sent_sec = htobe64(time_sent.tv_sec);
+ beph->time_sent_usec = htobe64(time_sent.tv_usec);
+
+ total_len += sizeof(struct bfd_echo_pkt);
+ uh->len =
+ htons(total_len - sizeof(struct iphdr) - sizeof(struct ethhdr));
+ uh->check = bfd_pkt_checksum(
+ uh, (total_len - sizeof(struct iphdr) - sizeof(struct ethhdr)),
+ (struct in6_addr *)&iph->saddr, AF_INET);
+
+ iph->tot_len = htons(total_len - sizeof(struct ethhdr));
+ iph->check = in_cksum((const void *)iph, sizeof(struct iphdr));
+
+ if (bp_udp_send_fp(sd, (uint8_t *)&sendbuff, total_len, bfd) == -1)
+ return;
+
+ bfd->stats.tx_echo_pkt++;
+}
+#endif
+
+void ptm_bfd_echo_snd(struct bfd_session *bfd)
+{
+ struct sockaddr *sa;
+ socklen_t salen;
+ int sd;
+ struct bfd_echo_pkt bep;
+ struct sockaddr_in sin;
+ struct sockaddr_in6 sin6;
+ struct bfd_vrf_global *bvrf = bfd_vrf_look_by_session(bfd);
+
+ if (!bvrf)
+ return;
+ if (!CHECK_FLAG(bfd->flags, BFD_SESS_FLAG_ECHO_ACTIVE))
+ SET_FLAG(bfd->flags, BFD_SESS_FLAG_ECHO_ACTIVE);
+
+ memset(&bep, 0, sizeof(bep));
+ bep.ver = BFD_ECHO_VERSION;
+ bep.len = BFD_ECHO_PKT_LEN;
+ bep.my_discr = htonl(bfd->discrs.my_discr);
+
+ if (CHECK_FLAG(bfd->flags, BFD_SESS_FLAG_IPV6)) {
+ if (bvrf->bg_echov6 == -1)
+ return;
+ sd = bvrf->bg_echov6;
+ memset(&sin6, 0, sizeof(sin6));
+ sin6.sin6_family = AF_INET6;
+ memcpy(&sin6.sin6_addr, &bfd->key.peer, sizeof(sin6.sin6_addr));
+ if (bfd->ifp && IN6_IS_ADDR_LINKLOCAL(&sin6.sin6_addr))
+ sin6.sin6_scope_id = bfd->ifp->ifindex;
+
+ sin6.sin6_port = htons(BFD_DEF_ECHO_PORT);
+#ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
+ sin6.sin6_len = sizeof(sin6);
+#endif /* HAVE_STRUCT_SOCKADDR_SA_LEN */
+
+ sa = (struct sockaddr *)&sin6;
+ salen = sizeof(sin6);
+ } else {
+ sd = bvrf->bg_echo;
+ memset(&sin, 0, sizeof(sin));
+ sin.sin_family = AF_INET;
+ memcpy(&sin.sin_addr, &bfd->key.peer, sizeof(sin.sin_addr));
+ sin.sin_port = htons(BFD_DEF_ECHO_PORT);
+#ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
+ sin.sin_len = sizeof(sin);
+#endif /* HAVE_STRUCT_SOCKADDR_SA_LEN */
+
+ sa = (struct sockaddr *)&sin;
+ salen = sizeof(sin);
+ }
+ if (bp_udp_send(sd, BFD_TTL_VAL, (uint8_t *)&bep, sizeof(bep), sa,
+ salen)
+ == -1)
+ return;
+
+ bfd->stats.tx_echo_pkt++;
+}
+
+static int ptm_bfd_process_echo_pkt(struct bfd_vrf_global *bvrf, int s)
+{
+ struct bfd_session *bfd;
+ uint32_t my_discr = 0;
+ uint64_t my_rtt = 0;
+ uint8_t ttl = 0;
+
+ /* Receive and parse echo packet. */
+ if (bp_bfd_echo_in(bvrf, s, &ttl, &my_discr, &my_rtt) == -1)
+ return 0;
+
+ /* Your discriminator not zero - use it to find session */
+ bfd = bfd_id_lookup(my_discr);
+ if (bfd == NULL) {
+ if (bglobal.debug_network)
+ zlog_debug("echo-packet: no matching session (id:%u)",
+ my_discr);
+ return -1;
+ }
+
+ if (!CHECK_FLAG(bfd->flags, BFD_SESS_FLAG_ECHO_ACTIVE)) {
+ if (bglobal.debug_network)
+ zlog_debug("echo-packet: echo disabled [%s] (id:%u)",
+ bs_to_string(bfd), my_discr);
+ return -1;
+ }
+
+ /* RTT Calculation: add current RTT to samples */
+ if (my_rtt != 0) {
+ bfd->rtt[bfd->rtt_index] = my_rtt;
+ bfd->rtt_index++;
+ if (bfd->rtt_index >= BFD_RTT_SAMPLE)
+ bfd->rtt_index = 0;
+ if (bfd->rtt_valid < BFD_RTT_SAMPLE)
+ bfd->rtt_valid++;
+ }
+
+ bfd->stats.rx_echo_pkt++;
+
+ /* Compute detect time */
+ bfd->echo_detect_TO = bfd->remote_detect_mult * bfd->echo_xmt_TO;
+
+ /* Update echo receive timeout. */
+ if (bfd->echo_detect_TO > 0)
+ bfd_echo_recvtimer_update(bfd);
+
+ return 0;
+}
+
+void ptm_bfd_snd(struct bfd_session *bfd, int fbit)
+{
+ struct bfd_pkt cp = {};
+
+ /* Set fields according to section 6.5.7 */
+ cp.diag = bfd->local_diag;
+ BFD_SETVER(cp.diag, BFD_VERSION);
+ cp.flags = 0;
+ BFD_SETSTATE(cp.flags, bfd->ses_state);
+
+ if (CHECK_FLAG(bfd->flags, BFD_SESS_FLAG_CBIT))
+ BFD_SETCBIT(cp.flags, BFD_CBIT);
+
+ BFD_SETDEMANDBIT(cp.flags, BFD_DEF_DEMAND);
+
+ /*
+ * Polling and Final can't be set at the same time.
+ *
+ * RFC 5880, Section 6.5.
+ */
+ BFD_SETFBIT(cp.flags, fbit);
+ if (fbit == 0)
+ BFD_SETPBIT(cp.flags, bfd->polling);
+
+ cp.detect_mult = bfd->detect_mult;
+ cp.len = BFD_PKT_LEN;
+ cp.discrs.my_discr = htonl(bfd->discrs.my_discr);
+ cp.discrs.remote_discr = htonl(bfd->discrs.remote_discr);
+ if (bfd->polling) {
+ cp.timers.desired_min_tx =
+ htonl(bfd->timers.desired_min_tx);
+ cp.timers.required_min_rx =
+ htonl(bfd->timers.required_min_rx);
+ } else {
+ /*
+ * We can only announce current setting on poll, this
+ * avoids timing mismatch with our peer and give it
+ * the oportunity to learn. See `bs_final_handler` for
+ * more information.
+ */
+ cp.timers.desired_min_tx =
+ htonl(bfd->cur_timers.desired_min_tx);
+ cp.timers.required_min_rx =
+ htonl(bfd->cur_timers.required_min_rx);
+ }
+ cp.timers.required_min_echo = htonl(bfd->timers.required_min_echo_rx);
+
+ if (_ptm_bfd_send(bfd, NULL, &cp, BFD_PKT_LEN) != 0)
+ return;
+
+ bfd->stats.tx_ctrl_pkt++;
+}
+
+#ifdef BFD_LINUX
+/*
+ * receive the ipv4 echo packet that was loopback in the peers forwarding plane
+ */
+ssize_t bfd_recv_ipv4_fp(int sd, uint8_t *msgbuf, size_t msgbuflen,
+ uint8_t *ttl, ifindex_t *ifindex,
+ struct sockaddr_any *local, struct sockaddr_any *peer)
+{
+ ssize_t mlen;
+ struct sockaddr_ll msgaddr;
+ struct msghdr msghdr;
+ struct iovec iov[1];
+ uint16_t recv_checksum;
+ uint16_t checksum;
+ struct iphdr *ip;
+ struct udphdr *uh;
+
+ /* Prepare the recvmsg params. */
+ iov[0].iov_base = msgbuf;
+ iov[0].iov_len = msgbuflen;
+
+ memset(&msghdr, 0, sizeof(msghdr));
+ msghdr.msg_name = &msgaddr;
+ msghdr.msg_namelen = sizeof(msgaddr);
+ msghdr.msg_iov = iov;
+ msghdr.msg_iovlen = 1;
+
+ mlen = recvmsg(sd, &msghdr, MSG_DONTWAIT);
+ if (mlen == -1) {
+ if (errno != EAGAIN || errno != EWOULDBLOCK || errno != EINTR)
+ zlog_err("%s: recv failed: %s", __func__,
+ strerror(errno));
+
+ return -1;
+ }
+
+ ip = (struct iphdr *)(msgbuf + sizeof(struct ethhdr));
+
+ /* verify ip checksum */
+ recv_checksum = ip->check;
+ ip->check = 0;
+ checksum = in_cksum((const void *)ip, sizeof(struct iphdr));
+ if (recv_checksum != checksum) {
+ if (bglobal.debug_network)
+ zlog_debug(
+ "%s: invalid iphdr checksum expected 0x%x rcvd 0x%x",
+ __func__, checksum, recv_checksum);
+ return -1;
+ }
+
+ *ttl = ip->ttl;
+ if (*ttl != 254) {
+ /* Echo should be looped in peer's forwarding plane, but it also
+ * comes up to BFD so silently drop it
+ */
+ if (ip->daddr == ip->saddr)
+ return -1;
+
+ if (bglobal.debug_network)
+ zlog_debug("%s: invalid TTL: %u", __func__, *ttl);
+ return -1;
+ }
+
+ local->sa_sin.sin_family = AF_INET;
+ memcpy(&local->sa_sin.sin_addr, &ip->saddr, sizeof(ip->saddr));
+ peer->sa_sin.sin_family = AF_INET;
+ memcpy(&peer->sa_sin.sin_addr, &ip->daddr, sizeof(ip->daddr));
+
+ *ifindex = msgaddr.sll_ifindex;
+
+ /* verify udp checksum */
+ uh = (struct udphdr *)(msgbuf + sizeof(struct iphdr) +
+ sizeof(struct ethhdr));
+ recv_checksum = uh->check;
+ uh->check = 0;
+ checksum = bfd_pkt_checksum(uh, ntohs(uh->len),
+ (struct in6_addr *)&ip->saddr, AF_INET);
+ if (recv_checksum != checksum) {
+ if (bglobal.debug_network)
+ zlog_debug(
+ "%s: invalid udphdr checksum expected 0x%x rcvd 0x%x",
+ __func__, checksum, recv_checksum);
+ return -1;
+ }
+ return mlen;
+}
+#endif
+
+ssize_t bfd_recv_ipv4(int sd, uint8_t *msgbuf, size_t msgbuflen, uint8_t *ttl,
+ ifindex_t *ifindex, struct sockaddr_any *local,
+ struct sockaddr_any *peer)
+{
+ struct cmsghdr *cm;
+ ssize_t mlen;
+ struct sockaddr_in msgaddr;
+ struct msghdr msghdr;
+ struct iovec iov[1];
+ uint8_t cmsgbuf[255];
+
+ /* Prepare the recvmsg params. */
+ iov[0].iov_base = msgbuf;
+ iov[0].iov_len = msgbuflen;
+
+ memset(&msghdr, 0, sizeof(msghdr));
+ msghdr.msg_name = &msgaddr;
+ msghdr.msg_namelen = sizeof(msgaddr);
+ msghdr.msg_iov = iov;
+ msghdr.msg_iovlen = 1;
+ msghdr.msg_control = cmsgbuf;
+ msghdr.msg_controllen = sizeof(cmsgbuf);
+
+ mlen = recvmsg(sd, &msghdr, MSG_DONTWAIT);
+ if (mlen == -1) {
+ if (errno != EAGAIN)
+ zlog_err("ipv4-recv: recv failed: %s", strerror(errno));
+
+ return -1;
+ }
+
+ /* Get source address */
+ peer->sa_sin = *((struct sockaddr_in *)(msghdr.msg_name));
+
+ /* Get and check TTL */
+ for (cm = CMSG_FIRSTHDR(&msghdr); cm != NULL;
+ cm = CMSG_NXTHDR(&msghdr, cm)) {
+ if (cm->cmsg_level != IPPROTO_IP)
+ continue;
+
+ switch (cm->cmsg_type) {
+#ifdef BFD_LINUX
+ case IP_TTL: {
+ uint32_t ttlval;
+
+ memcpy(&ttlval, CMSG_DATA(cm), sizeof(ttlval));
+ if (ttlval > 255) {
+ if (bglobal.debug_network)
+ zlog_debug("%s: invalid TTL: %u",
+ __func__, ttlval);
+ return -1;
+ }
+ *ttl = ttlval;
+ break;
+ }
+
+ case IP_PKTINFO: {
+ struct in_pktinfo *pi =
+ (struct in_pktinfo *)CMSG_DATA(cm);
+
+ if (pi == NULL)
+ break;
+
+ local->sa_sin.sin_family = AF_INET;
+ local->sa_sin.sin_addr = pi->ipi_addr;
+#ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
+ local->sa_sin.sin_len = sizeof(local->sa_sin);
+#endif /* HAVE_STRUCT_SOCKADDR_SA_LEN */
+
+ *ifindex = pi->ipi_ifindex;
+ break;
+ }
+#endif /* BFD_LINUX */
+#ifdef BFD_BSD
+ case IP_RECVTTL: {
+ memcpy(ttl, CMSG_DATA(cm), sizeof(*ttl));
+ break;
+ }
+
+ case IP_RECVDSTADDR: {
+ struct in_addr ia;
+
+ memcpy(&ia, CMSG_DATA(cm), sizeof(ia));
+ local->sa_sin.sin_family = AF_INET;
+ local->sa_sin.sin_addr = ia;
+#ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
+ local->sa_sin.sin_len = sizeof(local->sa_sin);
+#endif /* HAVE_STRUCT_SOCKADDR_SA_LEN */
+ break;
+ }
+#endif /* BFD_BSD */
+
+ default:
+ /*
+ * On *BSDs we expect to land here when skipping
+ * the IP_RECVIF header. It will be handled by
+ * getsockopt_ifindex() below.
+ */
+ /* NOTHING */
+ break;
+ }
+ }
+
+ /* OS agnostic way of getting interface name. */
+ if (*ifindex == IFINDEX_INTERNAL)
+ *ifindex = getsockopt_ifindex(AF_INET, &msghdr);
+
+ return mlen;
+}
+
+ssize_t bfd_recv_ipv6(int sd, uint8_t *msgbuf, size_t msgbuflen, uint8_t *ttl,
+ ifindex_t *ifindex, struct sockaddr_any *local,
+ struct sockaddr_any *peer)
+{
+ struct cmsghdr *cm;
+ struct in6_pktinfo *pi6 = NULL;
+ ssize_t mlen;
+ uint32_t ttlval;
+ struct sockaddr_in6 msgaddr6;
+ struct msghdr msghdr6;
+ struct iovec iov[1];
+ uint8_t cmsgbuf6[255];
+
+ /* Prepare the recvmsg params. */
+ iov[0].iov_base = msgbuf;
+ iov[0].iov_len = msgbuflen;
+
+ memset(&msghdr6, 0, sizeof(msghdr6));
+ msghdr6.msg_name = &msgaddr6;
+ msghdr6.msg_namelen = sizeof(msgaddr6);
+ msghdr6.msg_iov = iov;
+ msghdr6.msg_iovlen = 1;
+ msghdr6.msg_control = cmsgbuf6;
+ msghdr6.msg_controllen = sizeof(cmsgbuf6);
+
+ mlen = recvmsg(sd, &msghdr6, MSG_DONTWAIT);
+ if (mlen == -1) {
+ if (errno != EAGAIN)
+ zlog_err("ipv6-recv: recv failed: %s", strerror(errno));
+
+ return -1;
+ }
+
+ /* Get source address */
+ peer->sa_sin6 = *((struct sockaddr_in6 *)(msghdr6.msg_name));
+
+ /* Get and check TTL */
+ for (cm = CMSG_FIRSTHDR(&msghdr6); cm != NULL;
+ cm = CMSG_NXTHDR(&msghdr6, cm)) {
+ if (cm->cmsg_level != IPPROTO_IPV6)
+ continue;
+
+ if (cm->cmsg_type == IPV6_HOPLIMIT) {
+ memcpy(&ttlval, CMSG_DATA(cm), sizeof(ttlval));
+ if (ttlval > 255) {
+ if (bglobal.debug_network)
+ zlog_debug("%s: invalid TTL: %u",
+ __func__, ttlval);
+ return -1;
+ }
+
+ *ttl = ttlval;
+ } else if (cm->cmsg_type == IPV6_PKTINFO) {
+ pi6 = (struct in6_pktinfo *)CMSG_DATA(cm);
+ if (pi6) {
+ local->sa_sin6.sin6_family = AF_INET6;
+ local->sa_sin6.sin6_addr = pi6->ipi6_addr;
+#ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
+ local->sa_sin6.sin6_len = sizeof(local->sa_sin6);
+#endif /* HAVE_STRUCT_SOCKADDR_SA_LEN */
+
+ *ifindex = pi6->ipi6_ifindex;
+
+ /* Set scope ID for link local addresses. */
+ if (IN6_IS_ADDR_LINKLOCAL(
+ &peer->sa_sin6.sin6_addr))
+ peer->sa_sin6.sin6_scope_id = *ifindex;
+ if (IN6_IS_ADDR_LINKLOCAL(
+ &local->sa_sin6.sin6_addr))
+ local->sa_sin6.sin6_scope_id = *ifindex;
+ }
+ }
+ }
+
+ return mlen;
+}
+
+static void bfd_sd_reschedule(struct bfd_vrf_global *bvrf, int sd)
+{
+ if (sd == bvrf->bg_shop) {
+ THREAD_OFF(bvrf->bg_ev[0]);
+ thread_add_read(master, bfd_recv_cb, bvrf, bvrf->bg_shop,
+ &bvrf->bg_ev[0]);
+ } else if (sd == bvrf->bg_mhop) {
+ THREAD_OFF(bvrf->bg_ev[1]);
+ thread_add_read(master, bfd_recv_cb, bvrf, bvrf->bg_mhop,
+ &bvrf->bg_ev[1]);
+ } else if (sd == bvrf->bg_shop6) {
+ THREAD_OFF(bvrf->bg_ev[2]);
+ thread_add_read(master, bfd_recv_cb, bvrf, bvrf->bg_shop6,
+ &bvrf->bg_ev[2]);
+ } else if (sd == bvrf->bg_mhop6) {
+ THREAD_OFF(bvrf->bg_ev[3]);
+ thread_add_read(master, bfd_recv_cb, bvrf, bvrf->bg_mhop6,
+ &bvrf->bg_ev[3]);
+ } else if (sd == bvrf->bg_echo) {
+ THREAD_OFF(bvrf->bg_ev[4]);
+ thread_add_read(master, bfd_recv_cb, bvrf, bvrf->bg_echo,
+ &bvrf->bg_ev[4]);
+ } else if (sd == bvrf->bg_echov6) {
+ THREAD_OFF(bvrf->bg_ev[5]);
+ thread_add_read(master, bfd_recv_cb, bvrf, bvrf->bg_echov6,
+ &bvrf->bg_ev[5]);
+ }
+}
+
+static void cp_debug(bool mhop, struct sockaddr_any *peer,
+ struct sockaddr_any *local, ifindex_t ifindex,
+ vrf_id_t vrfid, const char *fmt, ...)
+{
+ char buf[512], peerstr[128], localstr[128], portstr[64], vrfstr[64];
+ va_list vl;
+
+ /* Don't to any processing if debug is disabled. */
+ if (bglobal.debug_network == false)
+ return;
+
+ if (peer->sa_sin.sin_family)
+ snprintf(peerstr, sizeof(peerstr), " peer:%s", satostr(peer));
+ else
+ peerstr[0] = 0;
+
+ if (local->sa_sin.sin_family)
+ snprintf(localstr, sizeof(localstr), " local:%s",
+ satostr(local));
+ else
+ localstr[0] = 0;
+
+ if (ifindex != IFINDEX_INTERNAL)
+ snprintf(portstr, sizeof(portstr), " port:%u", ifindex);
+ else
+ portstr[0] = 0;
+
+ if (vrfid != VRF_DEFAULT)
+ snprintf(vrfstr, sizeof(vrfstr), " vrf:%u", vrfid);
+ else
+ vrfstr[0] = 0;
+
+ va_start(vl, fmt);
+ vsnprintf(buf, sizeof(buf), fmt, vl);
+ va_end(vl);
+
+ zlog_debug("control-packet: %s [mhop:%s%s%s%s%s]", buf,
+ mhop ? "yes" : "no", peerstr, localstr, portstr, vrfstr);
+}
+
+void bfd_recv_cb(struct thread *t)
+{
+ int sd = THREAD_FD(t);
+ struct bfd_session *bfd;
+ struct bfd_pkt *cp;
+ bool is_mhop;
+ ssize_t mlen = 0;
+ uint8_t ttl = 0;
+ vrf_id_t vrfid;
+ ifindex_t ifindex = IFINDEX_INTERNAL;
+ struct sockaddr_any local, peer;
+ uint8_t msgbuf[1516];
+ struct interface *ifp = NULL;
+ struct bfd_vrf_global *bvrf = THREAD_ARG(t);
+
+ /* Schedule next read. */
+ bfd_sd_reschedule(bvrf, sd);
+
+ /* Handle echo packets. */
+ if (sd == bvrf->bg_echo || sd == bvrf->bg_echov6) {
+ ptm_bfd_process_echo_pkt(bvrf, sd);
+ return;
+ }
+
+ /* Sanitize input/output. */
+ memset(&local, 0, sizeof(local));
+ memset(&peer, 0, sizeof(peer));
+
+ /* Handle control packets. */
+ is_mhop = false;
+ if (sd == bvrf->bg_shop || sd == bvrf->bg_mhop) {
+ is_mhop = sd == bvrf->bg_mhop;
+ mlen = bfd_recv_ipv4(sd, msgbuf, sizeof(msgbuf), &ttl, &ifindex,
+ &local, &peer);
+ } else if (sd == bvrf->bg_shop6 || sd == bvrf->bg_mhop6) {
+ is_mhop = sd == bvrf->bg_mhop6;
+ mlen = bfd_recv_ipv6(sd, msgbuf, sizeof(msgbuf), &ttl, &ifindex,
+ &local, &peer);
+ }
+
+ /*
+ * With netns backend, we have a separate socket in each VRF. It means
+ * that bvrf here is correct and we believe the bvrf->vrf->vrf_id.
+ * With VRF-lite backend, we have a single socket in the default VRF.
+ * It means that we can't believe the bvrf->vrf->vrf_id. But in
+ * VRF-lite, the ifindex is globally unique, so we can retrieve the
+ * correct vrf_id from the interface.
+ */
+ vrfid = bvrf->vrf->vrf_id;
+ if (ifindex) {
+ ifp = if_lookup_by_index(ifindex, vrfid);
+ if (ifp)
+ vrfid = ifp->vrf->vrf_id;
+ }
+
+ /* Implement RFC 5880 6.8.6 */
+ if (mlen < BFD_PKT_LEN) {
+ cp_debug(is_mhop, &peer, &local, ifindex, vrfid,
+ "too small (%ld bytes)", mlen);
+ return;
+ }
+
+ /* Validate single hop packet TTL. */
+ if ((!is_mhop) && (ttl != BFD_TTL_VAL)) {
+ cp_debug(is_mhop, &peer, &local, ifindex, vrfid,
+ "invalid TTL: %d expected %d", ttl, BFD_TTL_VAL);
+ return;
+ }
+
+ /*
+ * Parse the control header for inconsistencies:
+ * - Invalid version;
+ * - Bad multiplier configuration;
+ * - Short packets;
+ * - Invalid discriminator;
+ */
+ cp = (struct bfd_pkt *)(msgbuf);
+ if (BFD_GETVER(cp->diag) != BFD_VERSION) {
+ cp_debug(is_mhop, &peer, &local, ifindex, vrfid,
+ "bad version %d", BFD_GETVER(cp->diag));
+ return;
+ }
+
+ if (cp->detect_mult == 0) {
+ cp_debug(is_mhop, &peer, &local, ifindex, vrfid,
+ "detect multiplier set to zero");
+ return;
+ }
+
+ if ((cp->len < BFD_PKT_LEN) || (cp->len > mlen)) {
+ cp_debug(is_mhop, &peer, &local, ifindex, vrfid, "too small");
+ return;
+ }
+
+ if (cp->discrs.my_discr == 0) {
+ cp_debug(is_mhop, &peer, &local, ifindex, vrfid,
+ "'my discriminator' is zero");
+ return;
+ }
+
+ /* Find the session that this packet belongs. */
+ bfd = ptm_bfd_sess_find(cp, &peer, &local, ifp, vrfid, is_mhop);
+ if (bfd == NULL) {
+ cp_debug(is_mhop, &peer, &local, ifindex, vrfid,
+ "no session found");
+ return;
+ }
+ /*
+ * We may have a situation where received packet is on wrong vrf
+ */
+ if (bfd && bfd->vrf && bfd->vrf->vrf_id != vrfid) {
+ cp_debug(is_mhop, &peer, &local, ifindex, vrfid,
+ "wrong vrfid.");
+ return;
+ }
+
+ /* Ensure that existing good sessions are not overridden. */
+ if (!cp->discrs.remote_discr && bfd->ses_state != PTM_BFD_DOWN &&
+ bfd->ses_state != PTM_BFD_ADM_DOWN) {
+ cp_debug(is_mhop, &peer, &local, ifindex, vrfid,
+ "'remote discriminator' is zero, not overridden");
+ return;
+ }
+
+ /*
+ * Multi hop: validate packet TTL.
+ * Single hop: set local address that received the packet.
+ * set peers mac address for echo packets
+ */
+ if (is_mhop) {
+ if (ttl < bfd->mh_ttl) {
+ cp_debug(is_mhop, &peer, &local, ifindex, vrfid,
+ "exceeded max hop count (expected %d, got %d)",
+ bfd->mh_ttl, ttl);
+ return;
+ }
+ } else {
+
+ if (bfd->local_address.sa_sin.sin_family == AF_UNSPEC)
+ bfd->local_address = local;
+#ifdef BFD_LINUX
+ if (ifp)
+ bfd_peer_mac_set(sd, bfd, &peer, ifp);
+#endif
+ }
+
+ bfd->stats.rx_ctrl_pkt++;
+
+ /*
+ * If no interface was detected, save the interface where the
+ * packet came in.
+ */
+ if (!is_mhop && bfd->ifp == NULL)
+ bfd->ifp = ifp;
+
+ /* Log remote discriminator changes. */
+ if ((bfd->discrs.remote_discr != 0)
+ && (bfd->discrs.remote_discr != ntohl(cp->discrs.my_discr)))
+ cp_debug(is_mhop, &peer, &local, ifindex, vrfid,
+ "remote discriminator mismatch (expected %u, got %u)",
+ bfd->discrs.remote_discr, ntohl(cp->discrs.my_discr));
+
+ bfd->discrs.remote_discr = ntohl(cp->discrs.my_discr);
+
+ /* Save remote diagnostics before state switch. */
+ bfd->remote_diag = cp->diag & BFD_DIAGMASK;
+
+ /* Update remote timers settings. */
+ bfd->remote_timers.desired_min_tx = ntohl(cp->timers.desired_min_tx);
+ bfd->remote_timers.required_min_rx = ntohl(cp->timers.required_min_rx);
+ bfd->remote_timers.required_min_echo =
+ ntohl(cp->timers.required_min_echo);
+ bfd->remote_detect_mult = cp->detect_mult;
+
+ if (BFD_GETCBIT(cp->flags))
+ bfd->remote_cbit = 1;
+ else
+ bfd->remote_cbit = 0;
+
+ /* State switch from section 6.2. */
+ bs_state_handler(bfd, BFD_GETSTATE(cp->flags));
+
+ /* RFC 5880, Section 6.5: handle POLL/FINAL negotiation sequence. */
+ if (bfd->polling && BFD_GETFBIT(cp->flags)) {
+ /* Disable polling. */
+ bfd->polling = 0;
+
+ /* Handle poll finalization. */
+ bs_final_handler(bfd);
+ }
+
+ /*
+ * Detection timeout calculation:
+ * The minimum detection timeout is the remote detection
+ * multipler (number of packets to be missed) times the agreed
+ * transmission interval.
+ *
+ * RFC 5880, Section 6.8.4.
+ */
+ if (bfd->cur_timers.required_min_rx > bfd->remote_timers.desired_min_tx)
+ bfd->detect_TO = bfd->remote_detect_mult
+ * bfd->cur_timers.required_min_rx;
+ else
+ bfd->detect_TO = bfd->remote_detect_mult
+ * bfd->remote_timers.desired_min_tx;
+
+ /* Apply new receive timer immediately. */
+ bfd_recvtimer_update(bfd);
+
+ /* Handle echo timers changes. */
+ bs_echo_timer_handler(bfd);
+
+ /*
+ * We've received a packet with the POLL bit set, we must send
+ * a control packet back with the FINAL bit set.
+ *
+ * RFC 5880, Section 6.5.
+ */
+ if (BFD_GETPBIT(cp->flags)) {
+ /* We are finalizing a poll negotiation. */
+ bs_final_handler(bfd);
+
+ /* Send the control packet with the final bit immediately. */
+ ptm_bfd_snd(bfd, 1);
+ }
+}
+
+/*
+ * bp_bfd_echo_in: proccesses an BFD echo packet. On TTL == BFD_TTL_VAL
+ * the packet is looped back or returns the my discriminator ID along
+ * with the TTL.
+ *
+ * Returns -1 on error or loopback or 0 on success.
+ */
+int bp_bfd_echo_in(struct bfd_vrf_global *bvrf, int sd, uint8_t *ttl,
+ uint32_t *my_discr, uint64_t *my_rtt)
+{
+ struct bfd_echo_pkt *bep;
+ ssize_t rlen;
+ struct sockaddr_any local, peer;
+ ifindex_t ifindex = IFINDEX_INTERNAL;
+ vrf_id_t vrfid = VRF_DEFAULT;
+ uint8_t msgbuf[1516];
+ size_t bfd_offset = 0;
+
+ if (sd == bvrf->bg_echo) {
+#ifdef BFD_LINUX
+ rlen = bfd_recv_ipv4_fp(sd, msgbuf, sizeof(msgbuf), ttl,
+ &ifindex, &local, &peer);
+
+ /* silently drop echo packet that is looped in fastpath but
+ * still comes up to BFD
+ */
+ if (rlen == -1)
+ return -1;
+ bfd_offset = sizeof(struct udphdr) + sizeof(struct iphdr) +
+ sizeof(struct ethhdr);
+#else
+ rlen = bfd_recv_ipv4(sd, msgbuf, sizeof(msgbuf), ttl, &ifindex,
+ &local, &peer);
+ bfd_offset = 0;
+#endif
+ } else {
+ rlen = bfd_recv_ipv6(sd, msgbuf, sizeof(msgbuf), ttl, &ifindex,
+ &local, &peer);
+ bfd_offset = 0;
+ }
+
+ /* Short packet, better not risk reading it. */
+ if (rlen < (ssize_t)sizeof(*bep)) {
+ cp_debug(false, &peer, &local, ifindex, vrfid,
+ "small echo packet");
+ return -1;
+ }
+
+ /* Test for loopback for ipv6, ipv4 is looped in forwarding plane */
+ if ((*ttl == BFD_TTL_VAL) && (sd == bvrf->bg_echov6)) {
+ bp_udp_send(sd, *ttl - 1, msgbuf, rlen,
+ (struct sockaddr *)&peer,
+ (sd == bvrf->bg_echo) ? sizeof(peer.sa_sin)
+ : sizeof(peer.sa_sin6));
+ return -1;
+ }
+
+ /* Read my discriminator from BFD Echo packet. */
+ bep = (struct bfd_echo_pkt *)(msgbuf + bfd_offset);
+ *my_discr = ntohl(bep->my_discr);
+ if (*my_discr == 0) {
+ cp_debug(false, &peer, &local, ifindex, vrfid,
+ "invalid echo packet discriminator (zero)");
+ return -1;
+ }
+
+#ifdef BFD_LINUX
+ /* RTT Calculation: determine RTT time of IPv4 echo pkt */
+ if (sd == bvrf->bg_echo) {
+ struct timeval time_sent = {0, 0};
+
+ time_sent.tv_sec = be64toh(bep->time_sent_sec);
+ time_sent.tv_usec = be64toh(bep->time_sent_usec);
+ *my_rtt = monotime_since(&time_sent, NULL);
+ }
+#endif
+
+ return 0;
+}
+
+#ifdef BFD_LINUX
+/*
+ * send a bfd packet with src/dst same IP so that the peer will receive
+ * the packet and forward it back to sender in the forwarding plane
+ */
+int bp_udp_send_fp(int sd, uint8_t *data, size_t datalen,
+ struct bfd_session *bfd)
+{
+ ssize_t wlen;
+ struct msghdr msg = {0};
+ struct iovec iov[1];
+ uint8_t msgctl[255];
+ struct sockaddr_ll sadr_ll = {0};
+
+ sadr_ll.sll_ifindex = bfd->ifp->ifindex;
+ sadr_ll.sll_halen = ETH_ALEN;
+ memcpy(sadr_ll.sll_addr, bfd->peer_hw_addr, sizeof(bfd->peer_hw_addr));
+ sadr_ll.sll_protocol = htons(ETH_P_IP);
+
+ /* Prepare message data. */
+ iov[0].iov_base = data;
+ iov[0].iov_len = datalen;
+
+ memset(msgctl, 0, sizeof(msgctl));
+ msg.msg_name = &sadr_ll;
+ msg.msg_namelen = sizeof(sadr_ll);
+ msg.msg_iov = iov;
+ msg.msg_iovlen = 1;
+
+ /* Send echo to peer */
+ wlen = sendmsg(sd, &msg, 0);
+
+ if (wlen <= 0) {
+ if (bglobal.debug_network)
+ zlog_debug("%s: loopback failure: (%d) %s", __func__,
+ errno, strerror(errno));
+ return -1;
+ } else if (wlen < (ssize_t)datalen) {
+ if (bglobal.debug_network)
+ zlog_debug("%s: partial send: %zd expected %zu",
+ __func__, wlen, datalen);
+ return -1;
+ }
+
+ return 0;
+}
+#endif
+
+int bp_udp_send(int sd, uint8_t ttl, uint8_t *data, size_t datalen,
+ struct sockaddr *to, socklen_t tolen)
+{
+ struct cmsghdr *cmsg;
+ ssize_t wlen;
+ int ttlval = ttl;
+ bool is_ipv6 = to->sa_family == AF_INET6;
+ struct msghdr msg;
+ struct iovec iov[1];
+ uint8_t msgctl[255];
+
+ /* Prepare message data. */
+ iov[0].iov_base = data;
+ iov[0].iov_len = datalen;
+
+ memset(&msg, 0, sizeof(msg));
+ memset(msgctl, 0, sizeof(msgctl));
+ msg.msg_name = to;
+ msg.msg_namelen = tolen;
+ msg.msg_iov = iov;
+ msg.msg_iovlen = 1;
+
+ /* Prepare the packet TTL information. */
+ if (ttl > 0) {
+ /* Use ancillary data. */
+ msg.msg_control = msgctl;
+ msg.msg_controllen = CMSG_LEN(sizeof(ttlval));
+
+ /* Configure the ancillary data. */
+ cmsg = CMSG_FIRSTHDR(&msg);
+ cmsg->cmsg_len = CMSG_LEN(sizeof(ttlval));
+ if (is_ipv6) {
+ cmsg->cmsg_level = IPPROTO_IPV6;
+ cmsg->cmsg_type = IPV6_HOPLIMIT;
+ } else {
+#ifdef BFD_LINUX
+ cmsg->cmsg_level = IPPROTO_IP;
+ cmsg->cmsg_type = IP_TTL;
+#else
+ /* FreeBSD does not support TTL in ancillary data. */
+ msg.msg_control = NULL;
+ msg.msg_controllen = 0;
+
+ bp_set_ttl(sd, ttl);
+#endif /* BFD_BSD */
+ }
+ memcpy(CMSG_DATA(cmsg), &ttlval, sizeof(ttlval));
+ }
+
+ /* Send echo back. */
+ wlen = sendmsg(sd, &msg, 0);
+ if (wlen <= 0) {
+ if (bglobal.debug_network)
+ zlog_debug("%s: loopback failure: (%d) %s", __func__,
+ errno, strerror(errno));
+ return -1;
+ } else if (wlen < (ssize_t)datalen) {
+ if (bglobal.debug_network)
+ zlog_debug("%s: partial send: %zd expected %zu",
+ __func__, wlen, datalen);
+ return -1;
+ }
+
+ return 0;
+}
+
+
+/*
+ * Sockets creation.
+ */
+
+
+/*
+ * IPv4 sockets
+ */
+int bp_set_ttl(int sd, uint8_t value)
+{
+ int ttl = value;
+
+ if (setsockopt(sd, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl)) == -1) {
+ zlog_warn("%s: setsockopt(IP_TTL, %d): %s", __func__, value,
+ strerror(errno));
+ return -1;
+ }
+
+ return 0;
+}
+
+int bp_set_tos(int sd, uint8_t value)
+{
+ int tos = value;
+
+ if (setsockopt(sd, IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) == -1) {
+ zlog_warn("%s: setsockopt(IP_TOS, %d): %s", __func__, value,
+ strerror(errno));
+ return -1;
+ }
+
+ return 0;
+}
+
+static bool bp_set_reuse_addr(int sd)
+{
+ int one = 1;
+
+ if (setsockopt(sd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)) == -1) {
+ zlog_warn("%s: setsockopt(SO_REUSEADDR, %d): %s", __func__, one,
+ strerror(errno));
+ return false;
+ }
+ return true;
+}
+
+static bool bp_set_reuse_port(int sd)
+{
+ int one = 1;
+
+ if (setsockopt(sd, SOL_SOCKET, SO_REUSEPORT, &one, sizeof(one)) == -1) {
+ zlog_warn("%s: setsockopt(SO_REUSEPORT, %d): %s", __func__, one,
+ strerror(errno));
+ return false;
+ }
+ return true;
+}
+
+
+static void bp_set_ipopts(int sd)
+{
+ int rcvttl = BFD_RCV_TTL_VAL;
+
+ if (!bp_set_reuse_addr(sd))
+ zlog_fatal("set-reuse-addr: failed");
+
+ if (!bp_set_reuse_port(sd))
+ zlog_fatal("set-reuse-port: failed");
+
+ if (bp_set_ttl(sd, BFD_TTL_VAL) != 0)
+ zlog_fatal("set-ipopts: TTL configuration failed");
+
+ if (setsockopt(sd, IPPROTO_IP, IP_RECVTTL, &rcvttl, sizeof(rcvttl))
+ == -1)
+ zlog_fatal("set-ipopts: setsockopt(IP_RECVTTL, %d): %s", rcvttl,
+ strerror(errno));
+
+#ifdef BFD_LINUX
+ int pktinfo = BFD_PKT_INFO_VAL;
+
+ /* Figure out address and interface to do the peer matching. */
+ if (setsockopt(sd, IPPROTO_IP, IP_PKTINFO, &pktinfo, sizeof(pktinfo))
+ == -1)
+ zlog_fatal("set-ipopts: setsockopt(IP_PKTINFO, %d): %s",
+ pktinfo, strerror(errno));
+#endif /* BFD_LINUX */
+#ifdef BFD_BSD
+ int yes = 1;
+
+ /* Find out our address for peer matching. */
+ if (setsockopt(sd, IPPROTO_IP, IP_RECVDSTADDR, &yes, sizeof(yes)) == -1)
+ zlog_fatal("set-ipopts: setsockopt(IP_RECVDSTADDR, %d): %s",
+ yes, strerror(errno));
+
+ /* Find out interface where the packet came in. */
+ if (setsockopt_ifindex(AF_INET, sd, yes) == -1)
+ zlog_fatal("set-ipopts: setsockopt_ipv4_ifindex(%d): %s", yes,
+ strerror(errno));
+#endif /* BFD_BSD */
+}
+
+static void bp_bind_ip(int sd, uint16_t port)
+{
+ struct sockaddr_in sin;
+
+ memset(&sin, 0, sizeof(sin));
+ sin.sin_family = AF_INET;
+ sin.sin_addr.s_addr = htonl(INADDR_ANY);
+ sin.sin_port = htons(port);
+ if (bind(sd, (struct sockaddr *)&sin, sizeof(sin)) == -1)
+ zlog_fatal("bind-ip: bind: %s", strerror(errno));
+}
+
+int bp_udp_shop(const struct vrf *vrf)
+{
+ int sd;
+
+ frr_with_privs(&bglobal.bfdd_privs) {
+ sd = vrf_socket(AF_INET, SOCK_DGRAM, PF_UNSPEC, vrf->vrf_id,
+ vrf->name);
+ }
+ if (sd == -1)
+ zlog_fatal("udp-shop: socket: %s", strerror(errno));
+
+ bp_set_ipopts(sd);
+ bp_bind_ip(sd, BFD_DEFDESTPORT);
+ return sd;
+}
+
+int bp_udp_mhop(const struct vrf *vrf)
+{
+ int sd;
+
+ frr_with_privs(&bglobal.bfdd_privs) {
+ sd = vrf_socket(AF_INET, SOCK_DGRAM, PF_UNSPEC, vrf->vrf_id,
+ vrf->name);
+ }
+ if (sd == -1)
+ zlog_fatal("udp-mhop: socket: %s", strerror(errno));
+
+ bp_set_ipopts(sd);
+ bp_bind_ip(sd, BFD_DEF_MHOP_DEST_PORT);
+
+ return sd;
+}
+
+int bp_peer_socket(const struct bfd_session *bs)
+{
+ int sd, pcount;
+ struct sockaddr_in sin;
+ static int srcPort = BFD_SRCPORTINIT;
+ const char *device_to_bind = NULL;
+
+ if (bs->key.ifname[0])
+ device_to_bind = (const char *)bs->key.ifname;
+ else if ((!vrf_is_backend_netns() && bs->vrf->vrf_id != VRF_DEFAULT)
+ || ((CHECK_FLAG(bs->flags, BFD_SESS_FLAG_MH)
+ && bs->key.vrfname[0])))
+ device_to_bind = (const char *)bs->key.vrfname;
+
+ frr_with_privs(&bglobal.bfdd_privs) {
+ sd = vrf_socket(AF_INET, SOCK_DGRAM, PF_UNSPEC,
+ bs->vrf->vrf_id, device_to_bind);
+ }
+ if (sd == -1) {
+ zlog_err("ipv4-new: failed to create socket: %s",
+ strerror(errno));
+ return -1;
+ }
+
+ /* Set TTL to 255 for all transmitted packets */
+ if (bp_set_ttl(sd, BFD_TTL_VAL) != 0) {
+ close(sd);
+ return -1;
+ }
+
+ /* Set TOS to CS6 for all transmitted packets */
+ if (bp_set_tos(sd, BFD_TOS_VAL) != 0) {
+ close(sd);
+ return -1;
+ }
+
+ /* Find an available source port in the proper range */
+ memset(&sin, 0, sizeof(sin));
+ sin.sin_family = AF_INET;
+#ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
+ sin.sin_len = sizeof(sin);
+#endif /* HAVE_STRUCT_SOCKADDR_SA_LEN */
+ memcpy(&sin.sin_addr, &bs->key.local, sizeof(sin.sin_addr));
+
+ pcount = 0;
+ do {
+ if ((++pcount) > (BFD_SRCPORTMAX - BFD_SRCPORTINIT)) {
+ /* Searched all ports, none available */
+ zlog_err("ipv4-new: failed to bind port: %s",
+ strerror(errno));
+ close(sd);
+ return -1;
+ }
+ if (srcPort >= BFD_SRCPORTMAX)
+ srcPort = BFD_SRCPORTINIT;
+ sin.sin_port = htons(srcPort++);
+ } while (bind(sd, (struct sockaddr *)&sin, sizeof(sin)) < 0);
+
+ return sd;
+}
+
+
+/*
+ * IPv6 sockets
+ */
+
+int bp_peer_socketv6(const struct bfd_session *bs)
+{
+ int sd, pcount;
+ struct sockaddr_in6 sin6;
+ static int srcPort = BFD_SRCPORTINIT;
+ const char *device_to_bind = NULL;
+
+ if (bs->key.ifname[0])
+ device_to_bind = (const char *)bs->key.ifname;
+ else if ((!vrf_is_backend_netns() && bs->vrf->vrf_id != VRF_DEFAULT)
+ || ((CHECK_FLAG(bs->flags, BFD_SESS_FLAG_MH)
+ && bs->key.vrfname[0])))
+ device_to_bind = (const char *)bs->key.vrfname;
+
+ frr_with_privs(&bglobal.bfdd_privs) {
+ sd = vrf_socket(AF_INET6, SOCK_DGRAM, PF_UNSPEC,
+ bs->vrf->vrf_id, device_to_bind);
+ }
+ if (sd == -1) {
+ zlog_err("ipv6-new: failed to create socket: %s",
+ strerror(errno));
+ return -1;
+ }
+
+ /* Set TTL to 255 for all transmitted packets */
+ if (bp_set_ttlv6(sd, BFD_TTL_VAL) != 0) {
+ close(sd);
+ return -1;
+ }
+
+ /* Set TOS to CS6 for all transmitted packets */
+ if (bp_set_tosv6(sd, BFD_TOS_VAL) != 0) {
+ close(sd);
+ return -1;
+ }
+
+ /* Find an available source port in the proper range */
+ memset(&sin6, 0, sizeof(sin6));
+ sin6.sin6_family = AF_INET6;
+#ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
+ sin6.sin6_len = sizeof(sin6);
+#endif /* HAVE_STRUCT_SOCKADDR_SA_LEN */
+ memcpy(&sin6.sin6_addr, &bs->key.local, sizeof(sin6.sin6_addr));
+ if (bs->ifp && IN6_IS_ADDR_LINKLOCAL(&sin6.sin6_addr))
+ sin6.sin6_scope_id = bs->ifp->ifindex;
+
+ pcount = 0;
+ do {
+ if ((++pcount) > (BFD_SRCPORTMAX - BFD_SRCPORTINIT)) {
+ /* Searched all ports, none available */
+ zlog_err("ipv6-new: failed to bind port: %s",
+ strerror(errno));
+ close(sd);
+ return -1;
+ }
+ if (srcPort >= BFD_SRCPORTMAX)
+ srcPort = BFD_SRCPORTINIT;
+ sin6.sin6_port = htons(srcPort++);
+ } while (bind(sd, (struct sockaddr *)&sin6, sizeof(sin6)) < 0);
+
+ return sd;
+}
+
+int bp_set_ttlv6(int sd, uint8_t value)
+{
+ int ttl = value;
+
+ if (setsockopt(sd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl))
+ == -1) {
+ zlog_warn("set-ttlv6: setsockopt(IPV6_UNICAST_HOPS, %d): %s",
+ value, strerror(errno));
+ return -1;
+ }
+
+ return 0;
+}
+
+int bp_set_tosv6(int sd, uint8_t value)
+{
+ int tos = value;
+
+ if (setsockopt(sd, IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos))
+ == -1) {
+ zlog_warn("set-tosv6: setsockopt(IPV6_TCLASS, %d): %s", value,
+ strerror(errno));
+ return -1;
+ }
+
+ return 0;
+}
+
+static void bp_set_ipv6opts(int sd)
+{
+ int ipv6_pktinfo = BFD_IPV6_PKT_INFO_VAL;
+ int ipv6_only = BFD_IPV6_ONLY_VAL;
+
+ if (!bp_set_reuse_addr(sd))
+ zlog_fatal("set-reuse-addr: failed");
+
+ if (!bp_set_reuse_port(sd))
+ zlog_fatal("set-reuse-port: failed");
+
+ if (bp_set_ttlv6(sd, BFD_TTL_VAL) == -1)
+ zlog_fatal(
+ "set-ipv6opts: setsockopt(IPV6_UNICAST_HOPS, %d): %s",
+ BFD_TTL_VAL, strerror(errno));
+
+ if (setsockopt_ipv6_hoplimit(sd, BFD_RCV_TTL_VAL) == -1)
+ zlog_fatal("set-ipv6opts: setsockopt(IPV6_HOPLIMIT, %d): %s",
+ BFD_RCV_TTL_VAL, strerror(errno));
+
+ if (setsockopt_ipv6_pktinfo(sd, ipv6_pktinfo) == -1)
+ zlog_fatal("set-ipv6opts: setsockopt(IPV6_PKTINFO, %d): %s",
+ ipv6_pktinfo, strerror(errno));
+
+ if (setsockopt(sd, IPPROTO_IPV6, IPV6_V6ONLY, &ipv6_only,
+ sizeof(ipv6_only))
+ == -1)
+ zlog_fatal("set-ipv6opts: setsockopt(IPV6_V6ONLY, %d): %s",
+ ipv6_only, strerror(errno));
+}
+
+static void bp_bind_ipv6(int sd, uint16_t port)
+{
+ struct sockaddr_in6 sin6;
+
+ memset(&sin6, 0, sizeof(sin6));
+ sin6.sin6_family = AF_INET6;
+ sin6.sin6_addr = in6addr_any;
+ sin6.sin6_port = htons(port);
+#ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
+ sin6.sin6_len = sizeof(sin6);
+#endif /* HAVE_STRUCT_SOCKADDR_SA_LEN */
+ if (bind(sd, (struct sockaddr *)&sin6, sizeof(sin6)) == -1)
+ zlog_fatal("bind-ipv6: bind: %s", strerror(errno));
+}
+
+int bp_udp6_shop(const struct vrf *vrf)
+{
+ int sd;
+
+ frr_with_privs(&bglobal.bfdd_privs) {
+ sd = vrf_socket(AF_INET6, SOCK_DGRAM, PF_UNSPEC, vrf->vrf_id,
+ vrf->name);
+ }
+ if (sd == -1) {
+ if (errno != EAFNOSUPPORT)
+ zlog_fatal("udp6-shop: socket: %s", strerror(errno));
+ else
+ zlog_warn("udp6-shop: V6 is not supported, continuing");
+
+ return -1;
+ }
+
+ bp_set_ipv6opts(sd);
+ bp_bind_ipv6(sd, BFD_DEFDESTPORT);
+
+ return sd;
+}
+
+int bp_udp6_mhop(const struct vrf *vrf)
+{
+ int sd;
+
+ frr_with_privs(&bglobal.bfdd_privs) {
+ sd = vrf_socket(AF_INET6, SOCK_DGRAM, PF_UNSPEC, vrf->vrf_id,
+ vrf->name);
+ }
+ if (sd == -1) {
+ if (errno != EAFNOSUPPORT)
+ zlog_fatal("udp6-mhop: socket: %s", strerror(errno));
+ else
+ zlog_warn("udp6-mhop: V6 is not supported, continuing");
+
+ return -1;
+ }
+
+ bp_set_ipv6opts(sd);
+ bp_bind_ipv6(sd, BFD_DEF_MHOP_DEST_PORT);
+
+ return sd;
+}
+
+#ifdef BFD_LINUX
+/* tcpdump -dd udp dst port 3785 */
+struct sock_filter my_filterudp[] = {
+ {0x28, 0, 0, 0x0000000c}, {0x15, 0, 8, 0x00000800},
+ {0x30, 0, 0, 0x00000017}, {0x15, 0, 6, 0x00000011},
+ {0x28, 0, 0, 0x00000014}, {0x45, 4, 0, 0x00001fff},
+ {0xb1, 0, 0, 0x0000000e}, {0x48, 0, 0, 0x00000010},
+ {0x15, 0, 1, 0x00000ec9}, {0x6, 0, 0, 0x00040000},
+ {0x6, 0, 0, 0x00000000},
+};
+
+#define MY_FILTER_LENGTH 11
+
+int bp_echo_socket(const struct vrf *vrf)
+{
+ int s;
+
+ frr_with_privs (&bglobal.bfdd_privs) {
+ s = vrf_socket(AF_PACKET, SOCK_RAW, ETH_P_IP, vrf->vrf_id,
+ vrf->name);
+ }
+
+ if (s == -1)
+ zlog_fatal("echo-socket: socket: %s", strerror(errno));
+
+ struct sock_fprog pf;
+ struct sockaddr_ll sll = {0};
+
+ /* adjust filter for socket to only receive ECHO packets */
+ pf.filter = my_filterudp;
+ pf.len = MY_FILTER_LENGTH;
+ if (setsockopt(s, SOL_SOCKET, SO_ATTACH_FILTER, &pf, sizeof(pf)) ==
+ -1) {
+ zlog_warn("%s: setsockopt(SO_ATTACH_FILTER): %s", __func__,
+ strerror(errno));
+ close(s);
+ return -1;
+ }
+
+ memset(&sll, 0, sizeof(sll));
+ sll.sll_family = AF_PACKET;
+ sll.sll_protocol = htons(ETH_P_IP);
+ sll.sll_ifindex = 0;
+ if (bind(s, (struct sockaddr *)&sll, sizeof(sll)) < 0) {
+ zlog_warn("Failed to bind echo socket: %s",
+ safe_strerror(errno));
+ close(s);
+ return -1;
+ }
+
+ return s;
+}
+#else
+int bp_echo_socket(const struct vrf *vrf)
+{
+ int s;
+
+ frr_with_privs(&bglobal.bfdd_privs) {
+ s = vrf_socket(AF_INET, SOCK_DGRAM, 0, vrf->vrf_id, vrf->name);
+ }
+ if (s == -1)
+ zlog_fatal("echo-socket: socket: %s", strerror(errno));
+
+ bp_set_ipopts(s);
+ bp_bind_ip(s, BFD_DEF_ECHO_PORT);
+
+ return s;
+}
+#endif
+
+int bp_echov6_socket(const struct vrf *vrf)
+{
+ int s;
+
+ frr_with_privs(&bglobal.bfdd_privs) {
+ s = vrf_socket(AF_INET6, SOCK_DGRAM, 0, vrf->vrf_id, vrf->name);
+ }
+ if (s == -1) {
+ if (errno != EAFNOSUPPORT)
+ zlog_fatal("echov6-socket: socket: %s",
+ strerror(errno));
+ else
+ zlog_warn("echov6-socket: V6 is not supported, continuing");
+
+ return -1;
+ }
+
+ bp_set_ipv6opts(s);
+ bp_bind_ipv6(s, BFD_DEF_ECHO_PORT);
+
+ return s;
+}
+
+#ifdef BFD_LINUX
+/* get peer's mac address to be used with Echo packets when they are looped in
+ * peers forwarding plane
+ */
+void bfd_peer_mac_set(int sd, struct bfd_session *bfd,
+ struct sockaddr_any *peer, struct interface *ifp)
+{
+ struct arpreq arpreq_;
+
+ if (CHECK_FLAG(bfd->flags, BFD_SESS_FLAG_MAC_SET))
+ return;
+ if (ifp->flags & IFF_NOARP)
+ return;
+
+ if (peer->sa_sin.sin_family == AF_INET) {
+ /* IPV4 */
+ struct sockaddr_in *addr =
+ (struct sockaddr_in *)&arpreq_.arp_pa;
+
+ memset(&arpreq_, 0, sizeof(struct arpreq));
+ addr->sin_family = AF_INET;
+ memcpy(&addr->sin_addr.s_addr, &peer->sa_sin.sin_addr,
+ sizeof(addr->sin_addr));
+ strlcpy(arpreq_.arp_dev, ifp->name, sizeof(arpreq_.arp_dev));
+
+ if (ioctl(sd, SIOCGARP, &arpreq_) < 0) {
+ zlog_warn(
+ "BFD: getting peer's mac on %s failed error %s",
+ ifp->name, strerror(errno));
+ UNSET_FLAG(bfd->flags, BFD_SESS_FLAG_MAC_SET);
+ memset(bfd->peer_hw_addr, 0, sizeof(bfd->peer_hw_addr));
+
+ } else {
+ memcpy(bfd->peer_hw_addr, arpreq_.arp_ha.sa_data,
+ sizeof(bfd->peer_hw_addr));
+ SET_FLAG(bfd->flags, BFD_SESS_FLAG_MAC_SET);
+ }
+ }
+}
+#endif