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. */
45 char ifname[IFNAMSIZ]; /* Interface name. */
48 /* A digested version of a route message sent down by the kernel to indicate
49 * that a route has changed. */
50 struct route_table_msg {
51 bool relevant; /* Should this message be processed? */
52 int nlmsg_type; /* e.g. RTM_NEWROUTE, RTM_DELROUTE. */
53 struct route_data rd; /* Data parsed from this message. */
56 static struct ovs_mutex route_table_mutex = OVS_MUTEX_INITIALIZER;
57 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 20);
59 /* Global change number for route-table, which should be incremented
60 * every time route_table_reset() is called. */
61 static uint64_t rt_change_seq;
63 static unsigned int register_count = 0;
64 static struct nln *nln = NULL;
65 static struct route_table_msg rtmsg;
66 static struct nln_notifier *route_notifier = NULL;
67 static struct nln_notifier *name_notifier = NULL;
69 static bool route_table_valid = false;
71 static int route_table_reset(void);
72 static void route_table_handle_msg(const struct route_table_msg *);
73 static bool route_table_parse(struct ofpbuf *, struct route_table_msg *);
74 static void route_table_change(const struct route_table_msg *, void *);
75 static void route_map_clear(void);
77 static void name_table_init(void);
78 static void name_table_uninit(void);
79 static void name_table_change(const struct rtnetlink_link_change *, void *);
82 route_table_get_change_seq(void)
87 /* Users of the route_table module should register themselves with this
88 * function before making any other route_table function calls. */
90 route_table_register(void)
91 OVS_EXCLUDED(route_table_mutex)
93 ovs_mutex_lock(&route_table_mutex);
94 if (!register_count) {
96 ovs_assert(!route_notifier);
98 nln = nln_create(NETLINK_ROUTE, RTNLGRP_IPV4_ROUTE,
99 (nln_parse_func *) route_table_parse, &rtmsg);
102 nln_notifier_create(nln, (nln_notify_func *) route_table_change,
110 ovs_mutex_unlock(&route_table_mutex);
113 /* Users of the route_table module should unregister themselves with this
114 * function when they will no longer be making any more route_table fuction
117 route_table_unregister(void)
118 OVS_EXCLUDED(route_table_mutex)
120 ovs_mutex_lock(&route_table_mutex);
123 if (!register_count) {
124 nln_notifier_destroy(route_notifier);
125 route_notifier = NULL;
132 ovs_mutex_unlock(&route_table_mutex);
135 /* Run periodically to update the locally maintained routing table. */
137 route_table_run(void)
138 OVS_EXCLUDED(route_table_mutex)
140 ovs_mutex_lock(&route_table_mutex);
142 rtnetlink_link_run();
145 if (!route_table_valid) {
149 ovs_mutex_unlock(&route_table_mutex);
152 /* Causes poll_block() to wake up when route_table updates are required. */
154 route_table_wait(void)
155 OVS_EXCLUDED(route_table_mutex)
157 ovs_mutex_lock(&route_table_mutex);
159 rtnetlink_link_wait();
162 ovs_mutex_unlock(&route_table_mutex);
166 route_table_reset(void)
169 struct rtgenmsg *rtmsg;
170 uint64_t reply_stub[NL_DUMP_BUFSIZE / 8];
171 struct ofpbuf request, reply, buf;
174 route_table_valid = true;
177 ofpbuf_init(&request, 0);
179 nl_msg_put_nlmsghdr(&request, sizeof *rtmsg, RTM_GETROUTE, NLM_F_REQUEST);
181 rtmsg = ofpbuf_put_zeros(&request, sizeof *rtmsg);
182 rtmsg->rtgen_family = AF_INET;
184 nl_dump_start(&dump, NETLINK_ROUTE, &request);
185 ofpbuf_uninit(&request);
187 ofpbuf_use_stub(&buf, reply_stub, sizeof reply_stub);
188 while (nl_dump_next(&dump, &reply, &buf)) {
189 struct route_table_msg msg;
191 if (route_table_parse(&reply, &msg)) {
192 route_table_handle_msg(&msg);
197 return nl_dump_done(&dump);
202 route_table_parse(struct ofpbuf *buf, struct route_table_msg *change)
206 static const struct nl_policy policy[] = {
207 [RTA_DST] = { .type = NL_A_U32, .optional = true },
208 [RTA_OIF] = { .type = NL_A_U32, .optional = false },
209 [RTA_GATEWAY] = { .type = NL_A_U32, .optional = true },
212 struct nlattr *attrs[ARRAY_SIZE(policy)];
214 parsed = nl_policy_parse(buf, NLMSG_HDRLEN + sizeof(struct rtmsg),
215 policy, attrs, ARRAY_SIZE(policy));
218 const struct rtmsg *rtm;
219 const struct nlmsghdr *nlmsg;
220 int rta_oif; /* Output interface index. */
222 nlmsg = ofpbuf_data(buf);
223 rtm = ofpbuf_at(buf, NLMSG_HDRLEN, sizeof *rtm);
225 if (rtm->rtm_family != AF_INET) {
226 VLOG_DBG_RL(&rl, "received non AF_INET rtnetlink route message");
230 memset(change, 0, sizeof *change);
231 change->relevant = true;
233 if (rtm->rtm_scope == RT_SCOPE_NOWHERE) {
234 change->relevant = false;
237 if (rtm->rtm_type != RTN_UNICAST &&
238 rtm->rtm_type != RTN_LOCAL) {
239 change->relevant = false;
241 change->nlmsg_type = nlmsg->nlmsg_type;
242 change->rd.rtm_dst_len = rtm->rtm_dst_len;
243 rta_oif = nl_attr_get_u32(attrs[RTA_OIF]);
245 if (!if_indextoname(rta_oif, change->rd.ifname)) {
248 VLOG_DBG_RL(&rl, "Could not find interface name[%u]: %s",
249 rta_oif, ovs_strerror(error));
253 if (attrs[RTA_DST]) {
254 change->rd.rta_dst = nl_attr_get_be32(attrs[RTA_DST]);
256 if (attrs[RTA_GATEWAY]) {
257 change->rd.rta_gw = nl_attr_get_be32(attrs[RTA_GATEWAY]);
262 VLOG_DBG_RL(&rl, "received unparseable rtnetlink route message");
269 route_table_change(const struct route_table_msg *change OVS_UNUSED,
270 void *aux OVS_UNUSED)
272 route_table_valid = false;
276 route_table_handle_msg(const struct route_table_msg *change)
278 if (change->relevant && change->nlmsg_type == RTM_NEWROUTE) {
279 const struct route_data *rd = &change->rd;
281 ovs_router_insert(rd->rta_dst, rd->rtm_dst_len,
282 rd->ifname, rd->rta_gw);
287 route_map_clear(void)
296 name_table_init(void)
298 name_notifier = rtnetlink_link_notifier_create(name_table_change, NULL);
302 name_table_uninit(void)
304 rtnetlink_link_notifier_destroy(name_notifier);
305 name_notifier = NULL;
309 name_table_change(const struct rtnetlink_link_change *change OVS_UNUSED,
310 void *aux OVS_UNUSED)
312 /* Changes to interface status can cause routing table changes that some
313 * versions of the linux kernel do not advertise for some reason. */
314 route_table_valid = false;