1 files changed, 266 insertions, 0 deletions
diff --git a/zebra/zebra_pw.c b/zebra/zebra_pw.c
new file mode 100644
index 0000000000..b8ce1826d3
--- /dev/null
+++ b/zebra/zebra_pw.c
@@ -0,0 +1,266 @@
+/* Zebra PW code
+ * Copyright (C) 2016 Volta 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 "log.h"
+#include "memory.h"
+#include "thread.h"
+#include "vrf.h"
+
+#include "zebra/debug.h"
+#include "zebra/rib.h"
+#include "zebra/zserv.h"
+#include "zebra/zebra_vrf.h"
+#include "zebra/zebra_pw.h"
+
+DEFINE_MTYPE_STATIC(LIB, PW, "Pseudowire")
+
+DEFINE_HOOK(pw_install, (struct zebra_pw *pw), (pw))
+DEFINE_HOOK(pw_uninstall, (struct zebra_pw *pw), (pw))
+
+extern struct zebra_t zebrad;
+
+static void zebra_pw_install(struct zebra_pw *);
+static void zebra_pw_uninstall(struct zebra_pw *);
+static int zebra_pw_install_retry(struct thread *);
+static int zebra_pw_check_reachability(struct zebra_pw *);
+static void zebra_pw_update_status(struct zebra_pw *, int);
+
+static inline int zebra_pw_compare(const struct zebra_pw *a,
+				     const struct zebra_pw *b)
+{
+	return (strcmp(a->ifname, b->ifname));
+}
+
+RB_GENERATE(zebra_pw_head, zebra_pw, entry, zebra_pw_compare)
+
+struct zebra_pw *zebra_pw_add(struct zebra_vrf *zvrf, const char *ifname,
+			      uint8_t protocol, struct zserv *client)
+{
+	struct zebra_pw *pw;
+
+	if (IS_ZEBRA_DEBUG_PW)
+		zlog_debug("%u: adding pseudowire %s protocol %s",
+			   zvrf_id(zvrf), ifname, zebra_route_string(protocol));
+
+	pw = XCALLOC(MTYPE_PW, sizeof(*pw));
+	strlcpy(pw->ifname, ifname, sizeof(pw->ifname));
+	pw->protocol = protocol;
+	pw->vrf_id = zvrf_id(zvrf);
+	pw->client = client;
+	pw->status = PW_STATUS_UP;
+
+	RB_INSERT(zebra_pw_head, &zvrf->pseudowires, pw);
+
+	return pw;
+}
+
+void zebra_pw_del(struct zebra_vrf *zvrf, struct zebra_pw *pw)
+{
+	if (IS_ZEBRA_DEBUG_PW)
+		zlog_debug("%u: deleting pseudowire %s protocol %s", pw->vrf_id,
+			   pw->ifname, zebra_route_string(pw->protocol));
+
+	/* uninstall */
+	if (pw->status == PW_STATUS_UP)
+		hook_call(pw_uninstall, pw);
+	else if (pw->install_retry_timer)
+		THREAD_TIMER_OFF(pw->install_retry_timer);
+
+	/* unlink and release memory */
+	RB_REMOVE(zebra_pw_head, &zvrf->pseudowires, pw);
+	XFREE(MTYPE_PW, pw);
+}
+
+void zebra_pw_change(struct zebra_pw *pw, ifindex_t ifindex, int type, int af,
+		     union g_addr *nexthop, uint32_t local_label,
+		     uint32_t remote_label, uint8_t flags,
+		     union pw_protocol_fields *data)
+{
+	pw->ifindex = ifindex;
+	pw->type = type;
+	pw->af = af;
+	pw->nexthop = *nexthop;
+	pw->local_label = local_label;
+	pw->remote_label = remote_label;
+	pw->flags = flags;
+	pw->data = *data;
+
+	if (pw->enabled)
+		zebra_pw_update(pw);
+	else
+		zebra_pw_uninstall(pw);
+}
+
+struct zebra_pw *zebra_pw_find(struct zebra_vrf *zvrf, const char *ifname)
+{
+	struct zebra_pw pw;
+	strlcpy(pw.ifname, ifname, sizeof(pw.ifname));
+	return (RB_FIND(zebra_pw_head, &zvrf->pseudowires, &pw));
+}
+
+void zebra_pw_update(struct zebra_pw *pw)
+{
+	if (zebra_pw_check_reachability(pw) < 0) {
+		zebra_pw_uninstall(pw);
+	} else {
+		/*
+		 * Install or reinstall the pseudowire (e.g. to update
+		 * parameters like the nexthop or the use of the control word).
+		 */
+		zebra_pw_install(pw);
+	}
+}
+
+static void zebra_pw_install(struct zebra_pw *pw)
+{
+	if (IS_ZEBRA_DEBUG_PW)
+		zlog_debug("%u: installing pseudowire %s protocol %s",
+			   pw->vrf_id, pw->ifname,
+			   zebra_route_string(pw->protocol));
+
+	if (hook_call(pw_install, pw)) {
+		zebra_pw_install_failure(pw);
+		return;
+	}
+
+	if (pw->status == PW_STATUS_DOWN)
+		zebra_pw_update_status(pw, PW_STATUS_UP);
+}
+
+static void zebra_pw_uninstall(struct zebra_pw *pw)
+{
+	if (pw->status == PW_STATUS_DOWN)
+		return;
+
+	if (IS_ZEBRA_DEBUG_PW)
+		zlog_debug("%u: uninstalling pseudowire %s protocol %s",
+			   pw->vrf_id, pw->ifname,
+			   zebra_route_string(pw->protocol));
+
+	/* ignore any possible error */
+	hook_call(pw_uninstall, pw);
+
+	if (pw->enabled)
+		zebra_pw_update_status(pw, PW_STATUS_DOWN);
+}
+
+/*
+ * Installation of the pseudowire in the kernel or hardware has failed. This
+ * function will notify the pseudowire client about the failure and schedule
+ * to retry the installation later. This function can be called by an external
+ * agent that performs the pseudowire installation in an asynchronous way.
+ */
+void zebra_pw_install_failure(struct zebra_pw *pw)
+{
+	if (IS_ZEBRA_DEBUG_PW)
+		zlog_debug("%u: failed installing pseudowire %s, "
+			   "scheduling retry in %u seconds", pw->vrf_id,
+			   pw->ifname, PW_INSTALL_RETRY_INTERVAL);
+
+	/* schedule to retry later */
+	THREAD_TIMER_OFF(pw->install_retry_timer);
+	pw->install_retry_timer =
+		thread_add_timer(zebrad.master, zebra_pw_install_retry,
+		pw, PW_INSTALL_RETRY_INTERVAL);
+
+	zebra_pw_update_status(pw, PW_STATUS_DOWN);
+}
+
+static int zebra_pw_install_retry(struct thread *thread)
+{
+	struct zebra_pw *pw = THREAD_ARG(thread);
+
+	pw->install_retry_timer = NULL;
+	zebra_pw_install(pw);
+
+	return 0;
+}
+
+static void zebra_pw_update_status(struct zebra_pw *pw, int status)
+{
+	pw->status = status;
+	if (pw->client)
+		zsend_pw_update(pw->client, pw);
+}
+
+static int zebra_pw_check_reachability(struct zebra_pw *pw)
+{
+	struct rib *rib;
+	struct nexthop *nexthop, *tnexthop;
+	int recursing;
+
+	/* TODO: consider GRE/L2TPv3 tunnels in addition to MPLS LSPs */
+
+	/* find route to the remote end of the pseudowire */
+	rib = rib_match(family2afi(pw->af), SAFI_UNICAST, pw->vrf_id,
+			&pw->nexthop, NULL);
+	if (!rib) {
+		if (IS_ZEBRA_DEBUG_PW)
+			zlog_warn("%s: no route found for %s", __func__,
+				  pw->ifname);
+		return -1;
+	}
+
+	/*
+	 * Need to ensure that there's a label binding for all nexthops.
+	 * Otherwise, ECMP for this route could render the pseudowire unusable.
+	 */
+	for (ALL_NEXTHOPS_RO(rib->nexthop, nexthop, tnexthop, recursing)) {
+		if (!nexthop->nh_label) {
+			if (IS_ZEBRA_DEBUG_PW)
+				zlog_warn("%s: unlabeled route for %s",
+				    __func__, pw->ifname);
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+void
+zebra_pw_client_close(struct zserv *client)
+{
+	struct vrf *vrf;
+	struct zebra_vrf *zvrf;
+	struct zebra_pw *pw, *tmp;
+
+	RB_FOREACH(vrf, vrf_id_head, &vrfs_by_id) {
+		zvrf = vrf->info;
+		RB_FOREACH_SAFE(pw, zebra_pw_head, &zvrf->pseudowires, tmp) {
+			if (pw->client != client)
+				continue;
+			zebra_pw_del(zvrf, pw);
+		}
+	}
+}
+
+void zebra_pw_init(struct zebra_vrf *zvrf)
+{
+	RB_INIT(&zvrf->pseudowires);
+}
+
+void zebra_pw_exit(struct zebra_vrf *zvrf)
+{
+	struct zebra_pw *pw;
+
+	while ((pw = RB_ROOT(&zvrf->pseudowires)) != NULL)
+		zebra_pw_del(zvrf, pw);
+}