2 * Copyright (c) 2011, 2012, 2013, 2014 Nicira, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
19 #include "route-table.h"
22 #include <arpa/inet.h>
23 #include <sys/socket.h>
24 #include <linux/rtnetlink.h>
29 #include "netlink-notifier.h"
30 #include "netlink-socket.h"
32 #include "ovs-router.h"
33 #include "rtnetlink-link.h"
36 VLOG_DEFINE_THIS_MODULE(route_table);
39 /* Copied from struct rtmsg. */
40 unsigned char rtm_dst_len;
42 /* Extracted from Netlink attributes. */
43 ovs_be32 rta_dst; /* 0 if missing. */
44 char ifname[IFNAMSIZ]; /* Interface name. */
47 /* A digested version of a route message sent down by the kernel to indicate
48 * that a route has changed. */
49 struct route_table_msg {
50 bool relevant; /* Should this message be processed? */
51 int nlmsg_type; /* e.g. RTM_NEWROUTE, RTM_DELROUTE. */
52 struct route_data rd; /* Data parsed from this message. */
55 static struct ovs_mutex route_table_mutex = OVS_MUTEX_INITIALIZER;
56 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 20);
58 /* Global change number for route-table, which should be incremented
59 * every time route_table_reset() is called. */
60 static uint64_t rt_change_seq;
62 static unsigned int register_count = 0;
63 static struct nln *nln = NULL;
64 static struct route_table_msg rtmsg;
65 static struct nln_notifier *route_notifier = NULL;
66 static struct nln_notifier *name_notifier = NULL;
68 static bool route_table_valid = false;
70 static int route_table_reset(void);
71 static void route_table_handle_msg(const struct route_table_msg *);
72 static bool route_table_parse(struct ofpbuf *, struct route_table_msg *);
73 static void route_table_change(const struct route_table_msg *, void *);
74 static void route_map_clear(void);
76 static void name_table_init(void);
77 static void name_table_uninit(void);
78 static void name_table_change(const struct rtnetlink_link_change *, void *);
81 route_table_get_change_seq(void)
86 /* Users of the route_table module should register themselves with this
87 * function before making any other route_table function calls. */
89 route_table_register(void)
90 OVS_EXCLUDED(route_table_mutex)
92 ovs_mutex_lock(&route_table_mutex);
93 if (!register_count) {
95 ovs_assert(!route_notifier);
97 nln = nln_create(NETLINK_ROUTE, RTNLGRP_IPV4_ROUTE,
98 (nln_parse_func *) route_table_parse, &rtmsg);
101 nln_notifier_create(nln, (nln_notify_func *) route_table_change,
109 ovs_mutex_unlock(&route_table_mutex);
112 /* Users of the route_table module should unregister themselves with this
113 * function when they will no longer be making any more route_table fuction
116 route_table_unregister(void)
117 OVS_EXCLUDED(route_table_mutex)
119 ovs_mutex_lock(&route_table_mutex);
122 if (!register_count) {
123 nln_notifier_destroy(route_notifier);
124 route_notifier = NULL;
131 ovs_mutex_unlock(&route_table_mutex);
134 /* Run periodically to update the locally maintained routing table. */
136 route_table_run(void)
137 OVS_EXCLUDED(route_table_mutex)
139 ovs_mutex_lock(&route_table_mutex);
141 rtnetlink_link_run();
144 if (!route_table_valid) {
148 ovs_mutex_unlock(&route_table_mutex);
151 /* Causes poll_block() to wake up when route_table updates are required. */
153 route_table_wait(void)
154 OVS_EXCLUDED(route_table_mutex)
156 ovs_mutex_lock(&route_table_mutex);
158 rtnetlink_link_wait();
161 ovs_mutex_unlock(&route_table_mutex);
165 route_table_reset(void)
168 struct rtgenmsg *rtmsg;
169 uint64_t reply_stub[NL_DUMP_BUFSIZE / 8];
170 struct ofpbuf request, reply, buf;
173 route_table_valid = true;
176 ofpbuf_init(&request, 0);
178 nl_msg_put_nlmsghdr(&request, sizeof *rtmsg, RTM_GETROUTE, NLM_F_REQUEST);
180 rtmsg = ofpbuf_put_zeros(&request, sizeof *rtmsg);
181 rtmsg->rtgen_family = AF_INET;
183 nl_dump_start(&dump, NETLINK_ROUTE, &request);
184 ofpbuf_uninit(&request);
186 ofpbuf_use_stub(&buf, reply_stub, sizeof reply_stub);
187 while (nl_dump_next(&dump, &reply, &buf)) {
188 struct route_table_msg msg;
190 if (route_table_parse(&reply, &msg)) {
191 route_table_handle_msg(&msg);
196 return nl_dump_done(&dump);
201 route_table_parse(struct ofpbuf *buf, struct route_table_msg *change)
205 static const struct nl_policy policy[] = {
206 [RTA_DST] = { .type = NL_A_U32, .optional = true },
207 [RTA_OIF] = { .type = NL_A_U32, .optional = false },
210 struct nlattr *attrs[ARRAY_SIZE(policy)];
212 parsed = nl_policy_parse(buf, NLMSG_HDRLEN + sizeof(struct rtmsg),
213 policy, attrs, ARRAY_SIZE(policy));
216 const struct rtmsg *rtm;
217 const struct nlmsghdr *nlmsg;
218 int rta_oif; /* Output interface index. */
220 nlmsg = ofpbuf_data(buf);
221 rtm = ofpbuf_at(buf, NLMSG_HDRLEN, sizeof *rtm);
223 if (rtm->rtm_family != AF_INET) {
224 VLOG_DBG_RL(&rl, "received non AF_INET rtnetlink route message");
228 memset(change, 0, sizeof *change);
229 change->relevant = true;
231 if (rtm->rtm_scope == RT_SCOPE_NOWHERE) {
232 change->relevant = false;
235 if (rtm->rtm_type != RTN_UNICAST &&
236 rtm->rtm_type != RTN_LOCAL) {
237 change->relevant = false;
239 change->nlmsg_type = nlmsg->nlmsg_type;
240 change->rd.rtm_dst_len = rtm->rtm_dst_len;
241 rta_oif = nl_attr_get_u32(attrs[RTA_OIF]);
243 if (!if_indextoname(rta_oif, change->rd.ifname)) {
246 VLOG_DBG_RL(&rl, "Could not find interface name[%u]: %s",
247 rta_oif, ovs_strerror(error));
251 if (attrs[RTA_DST]) {
252 change->rd.rta_dst = nl_attr_get_be32(attrs[RTA_DST]);
256 VLOG_DBG_RL(&rl, "received unparseable rtnetlink route message");
263 route_table_change(const struct route_table_msg *change OVS_UNUSED,
264 void *aux OVS_UNUSED)
266 route_table_valid = false;
270 route_table_handle_msg(const struct route_table_msg *change)
272 if (change->relevant && change->nlmsg_type == RTM_NEWROUTE) {
273 const struct route_data *rd = &change->rd;
275 ovs_router_insert(rd->rta_dst, rd->rtm_dst_len, rd->ifname, 0);
280 route_map_clear(void)
289 name_table_init(void)
291 name_notifier = rtnetlink_link_notifier_create(name_table_change, NULL);
295 name_table_uninit(void)
297 rtnetlink_link_notifier_destroy(name_notifier);
298 name_notifier = NULL;
302 name_table_change(const struct rtnetlink_link_change *change OVS_UNUSED,
303 void *aux OVS_UNUSED)
305 /* Changes to interface status can cause routing table changes that some
306 * versions of the linux kernel do not advertise for some reason. */
307 route_table_valid = false;