1 files changed, 291 insertions, 0 deletions
diff --git a/pimd/pim_msdp_socket.c b/pimd/pim_msdp_socket.c
new file mode 100644
index 0000000..819a747
--- /dev/null
+++ b/pimd/pim_msdp_socket.c
@@ -0,0 +1,291 @@
+/*
+ * IP MSDP socket management
+ * Copyright (C) 2016 Cumulus Networks, Inc.
+ *
+ * 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
+ */
+
+#include <zebra.h>
+
+#include <lib/log.h>
+#include <lib/network.h>
+#include <lib/sockunion.h>
+#include <lib/thread.h>
+#include <lib/vty.h>
+#include <lib/if.h>
+#include <lib/vrf.h>
+#include <lib/lib_errors.h>
+
+#include "pimd.h"
+#include "pim_instance.h"
+#include "pim_sock.h"
+#include "pim_errors.h"
+
+#include "pim_msdp.h"
+#include "pim_msdp_socket.h"
+
+#include "sockopt.h"
+
+/* increase socket send buffer size */
+static void pim_msdp_update_sock_send_buffer_size(int fd)
+{
+	int size = PIM_MSDP_SOCKET_SNDBUF_SIZE;
+	int optval;
+	socklen_t optlen = sizeof(optval);
+
+	if (getsockopt(fd, SOL_SOCKET, SO_SNDBUF, &optval, &optlen) < 0) {
+		flog_err_sys(EC_LIB_SOCKET,
+			     "getsockopt of SO_SNDBUF failed %s",
+			     safe_strerror(errno));
+		return;
+	}
+
+	if (optval < size) {
+		if (setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &size, sizeof(size))
+		    < 0) {
+			flog_err_sys(EC_LIB_SOCKET,
+				     "Couldn't increase send buffer: %s",
+				     safe_strerror(errno));
+		}
+	}
+}
+
+/* passive peer socket accept */
+static void pim_msdp_sock_accept(struct thread *thread)
+{
+	union sockunion su;
+	struct pim_instance *pim = THREAD_ARG(thread);
+	int accept_sock;
+	int msdp_sock;
+	struct pim_msdp_peer *mp;
+
+	sockunion_init(&su);
+
+	/* re-register accept thread */
+	accept_sock = THREAD_FD(thread);
+	if (accept_sock < 0) {
+		flog_err(EC_LIB_DEVELOPMENT, "accept_sock is negative value %d",
+			 accept_sock);
+		return;
+	}
+	pim->msdp.listener.thread = NULL;
+	thread_add_read(router->master, pim_msdp_sock_accept, pim, accept_sock,
+			&pim->msdp.listener.thread);
+
+	/* accept client connection. */
+	msdp_sock = sockunion_accept(accept_sock, &su);
+	if (msdp_sock < 0) {
+		flog_err_sys(EC_LIB_SOCKET, "pim_msdp_sock_accept failed (%s)",
+			     safe_strerror(errno));
+		return;
+	}
+
+	/* see if have peer config for this */
+	mp = pim_msdp_peer_find(pim, su.sin.sin_addr);
+	if (!mp || !PIM_MSDP_PEER_IS_LISTENER(mp)) {
+		++pim->msdp.rejected_accepts;
+		if (PIM_DEBUG_MSDP_EVENTS) {
+			flog_err(EC_PIM_MSDP_PACKET,
+				 "msdp peer connection refused from %pSU", &su);
+		}
+		close(msdp_sock);
+		return;
+	}
+
+	if (PIM_DEBUG_MSDP_INTERNAL) {
+		zlog_debug("MSDP peer %s accept success%s", mp->key_str,
+			   mp->fd >= 0 ? "(dup)" : "");
+	}
+
+	/* if we have an existing connection we need to kill that one
+	 * with this one */
+	if (mp->fd >= 0) {
+		if (PIM_DEBUG_MSDP_EVENTS) {
+			zlog_notice(
+				"msdp peer new connection from %pSU stop old connection",
+				&su);
+		}
+		pim_msdp_peer_stop_tcp_conn(mp, true /* chg_state */);
+	}
+	mp->fd = msdp_sock;
+	set_nonblocking(mp->fd);
+	pim_msdp_update_sock_send_buffer_size(mp->fd);
+	pim_msdp_peer_established(mp);
+}
+
+/* global listener for the MSDP well know TCP port */
+int pim_msdp_sock_listen(struct pim_instance *pim)
+{
+	int sock;
+	int socklen;
+	struct sockaddr_in sin;
+	int rc;
+	struct pim_msdp_listener *listener = &pim->msdp.listener;
+
+	if (pim->msdp.flags & PIM_MSDPF_LISTENER) {
+		/* listener already setup */
+		return 0;
+	}
+
+	sock = socket(AF_INET, SOCK_STREAM, 0);
+	if (sock < 0) {
+		flog_err_sys(EC_LIB_SOCKET, "socket: %s", safe_strerror(errno));
+		return sock;
+	}
+
+	memset(&sin, 0, sizeof(struct sockaddr_in));
+	sin.sin_family = AF_INET;
+	sin.sin_port = htons(PIM_MSDP_TCP_PORT);
+	socklen = sizeof(struct sockaddr_in);
+#ifdef HAVE_STRUCT_SOCKADDR_IN_SIN_LEN
+	sin.sin_len = socklen;
+#endif /* HAVE_STRUCT_SOCKADDR_IN_SIN_LEN */
+
+	sockopt_reuseaddr(sock);
+	sockopt_reuseport(sock);
+
+	if (pim->vrf->vrf_id != VRF_DEFAULT) {
+		struct interface *ifp =
+			if_lookup_by_name(pim->vrf->name, pim->vrf->vrf_id);
+		if (!ifp) {
+			flog_err(EC_LIB_INTERFACE,
+				 "%s: Unable to lookup vrf interface: %s",
+				 __func__, pim->vrf->name);
+			close(sock);
+			return -1;
+		}
+		if (pim_socket_bind(sock, ifp)) {
+			flog_err_sys(EC_LIB_SOCKET,
+				     "%s: Unable to bind to socket: %s",
+				     __func__, safe_strerror(errno));
+			close(sock);
+			return -1;
+		}
+	}
+
+	frr_with_privs(&pimd_privs) {
+		/* bind to well known TCP port */
+		rc = bind(sock, (struct sockaddr *)&sin, socklen);
+	}
+
+	if (rc < 0) {
+		flog_err_sys(EC_LIB_SOCKET,
+			     "pim_msdp_socket bind to port %d: %s",
+			     ntohs(sin.sin_port), safe_strerror(errno));
+		close(sock);
+		return rc;
+	}
+
+	rc = listen(sock, 3 /* backlog */);
+	if (rc < 0) {
+		flog_err_sys(EC_LIB_SOCKET, "pim_msdp_socket listen: %s",
+			     safe_strerror(errno));
+		close(sock);
+		return rc;
+	}
+
+	/* Set socket DSCP byte */
+	if (setsockopt_ipv4_tos(sock, IPTOS_PREC_INTERNETCONTROL)) {
+		zlog_warn("can't set sockopt IP_TOS to MSDP socket %d: %s",
+				sock, safe_strerror(errno));
+	}
+
+	/* add accept thread */
+	listener->fd = sock;
+	memcpy(&listener->su, &sin, socklen);
+	thread_add_read(pim->msdp.master, pim_msdp_sock_accept, pim, sock,
+			&listener->thread);
+
+	pim->msdp.flags |= PIM_MSDPF_LISTENER;
+	return 0;
+}
+
+/* active peer socket setup */
+int pim_msdp_sock_connect(struct pim_msdp_peer *mp)
+{
+	int rc;
+
+	if (PIM_DEBUG_MSDP_INTERNAL) {
+		zlog_debug("MSDP peer %s attempt connect%s", mp->key_str,
+			   mp->fd < 0 ? "" : "(dup)");
+	}
+
+	/* if we have an existing connection we need to kill that one
+	 * with this one */
+	if (mp->fd >= 0) {
+		if (PIM_DEBUG_MSDP_EVENTS) {
+			zlog_notice(
+				"msdp duplicate connect to %s nuke old connection",
+				mp->key_str);
+		}
+		pim_msdp_peer_stop_tcp_conn(mp, false /* chg_state */);
+	}
+
+	/* Make socket for the peer. */
+	mp->fd = sockunion_socket(&mp->su_peer);
+	if (mp->fd < 0) {
+		flog_err_sys(EC_LIB_SOCKET,
+			     "pim_msdp_socket socket failure: %s",
+			     safe_strerror(errno));
+		return -1;
+	}
+
+	if (mp->pim->vrf->vrf_id != VRF_DEFAULT) {
+		struct interface *ifp = if_lookup_by_name(mp->pim->vrf->name,
+							  mp->pim->vrf->vrf_id);
+		if (!ifp) {
+			flog_err(EC_LIB_INTERFACE,
+				 "%s: Unable to lookup vrf interface: %s",
+				 __func__, mp->pim->vrf->name);
+			return -1;
+		}
+		if (pim_socket_bind(mp->fd, ifp)) {
+			flog_err_sys(EC_LIB_SOCKET,
+				     "%s: Unable to bind to socket: %s",
+				     __func__, safe_strerror(errno));
+			close(mp->fd);
+			mp->fd = -1;
+			return -1;
+		}
+	}
+
+	set_nonblocking(mp->fd);
+
+	/* Set socket send buffer size */
+	pim_msdp_update_sock_send_buffer_size(mp->fd);
+	sockopt_reuseaddr(mp->fd);
+	sockopt_reuseport(mp->fd);
+
+	/* source bind */
+	rc = sockunion_bind(mp->fd, &mp->su_local, 0, &mp->su_local);
+	if (rc < 0) {
+		flog_err_sys(EC_LIB_SOCKET,
+			     "pim_msdp_socket connect bind failure: %s",
+			     safe_strerror(errno));
+		close(mp->fd);
+		mp->fd = -1;
+		return rc;
+	}
+
+	/* Set socket DSCP byte */
+	if (setsockopt_ipv4_tos(mp->fd, IPTOS_PREC_INTERNETCONTROL)) {
+		zlog_warn("can't set sockopt IP_TOS to MSDP socket %d: %s",
+				mp->fd, safe_strerror(errno));
+	}
+
+	/* Connect to the remote mp. */
+	return (sockunion_connect(mp->fd, &mp->su_peer,
+				  htons(PIM_MSDP_TCP_PORT), 0));
+}