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 "ovs-router-linux.h"
34 #include "rtnetlink-link.h"
37 VLOG_DEFINE_THIS_MODULE(route_table);
40 /* Copied from struct rtmsg. */
41 unsigned char rtm_dst_len;
43 /* Extracted from Netlink attributes. */
44 ovs_be32 rta_dst; /* 0 if missing. */
46 char ifname[IFNAMSIZ]; /* Interface name. */
49 /* A digested version of a route message sent down by the kernel to indicate
50 * that a route has changed. */
51 struct route_table_msg {
52 bool relevant; /* Should this message be processed? */
53 int nlmsg_type; /* e.g. RTM_NEWROUTE, RTM_DELROUTE. */
54 struct route_data rd; /* Data parsed from this message. */
57 static struct ovs_mutex route_table_mutex = OVS_MUTEX_INITIALIZER;
58 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(5, 20);
60 /* Global change number for route-table, which should be incremented
61 * every time route_table_reset() is called. */
62 static uint64_t rt_change_seq;
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_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_init(void)
90 OVS_EXCLUDED(route_table_mutex)
92 ovs_mutex_lock(&route_table_mutex);
94 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,
107 ovs_mutex_unlock(&route_table_mutex);
110 /* Run periodically to update the locally maintained routing table. */
112 route_table_run(void)
113 OVS_EXCLUDED(route_table_mutex)
115 ovs_mutex_lock(&route_table_mutex);
117 rtnetlink_link_run();
120 if (!route_table_valid) {
124 ovs_mutex_unlock(&route_table_mutex);
127 /* Causes poll_block() to wake up when route_table updates are required. */
129 route_table_wait(void)
130 OVS_EXCLUDED(route_table_mutex)
132 ovs_mutex_lock(&route_table_mutex);
134 rtnetlink_link_wait();
137 ovs_mutex_unlock(&route_table_mutex);
141 route_table_reset(void)
144 struct rtgenmsg *rtmsg;
145 uint64_t reply_stub[NL_DUMP_BUFSIZE / 8];
146 struct ofpbuf request, reply, buf;
149 route_table_valid = true;
152 ofpbuf_init(&request, 0);
154 nl_msg_put_nlmsghdr(&request, sizeof *rtmsg, RTM_GETROUTE, NLM_F_REQUEST);
156 rtmsg = ofpbuf_put_zeros(&request, sizeof *rtmsg);
157 rtmsg->rtgen_family = AF_INET;
159 nl_dump_start(&dump, NETLINK_ROUTE, &request);
160 ofpbuf_uninit(&request);
162 ofpbuf_use_stub(&buf, reply_stub, sizeof reply_stub);
163 while (nl_dump_next(&dump, &reply, &buf)) {
164 struct route_table_msg msg;
166 if (route_table_parse(&reply, &msg)) {
167 route_table_handle_msg(&msg);
172 return nl_dump_done(&dump);
177 route_table_parse(struct ofpbuf *buf, struct route_table_msg *change)
181 static const struct nl_policy policy[] = {
182 [RTA_DST] = { .type = NL_A_U32, .optional = true },
183 [RTA_OIF] = { .type = NL_A_U32, .optional = false },
184 [RTA_GATEWAY] = { .type = NL_A_U32, .optional = true },
187 struct nlattr *attrs[ARRAY_SIZE(policy)];
189 parsed = nl_policy_parse(buf, NLMSG_HDRLEN + sizeof(struct rtmsg),
190 policy, attrs, ARRAY_SIZE(policy));
193 const struct rtmsg *rtm;
194 const struct nlmsghdr *nlmsg;
195 int rta_oif; /* Output interface index. */
197 nlmsg = ofpbuf_data(buf);
198 rtm = ofpbuf_at(buf, NLMSG_HDRLEN, sizeof *rtm);
200 if (rtm->rtm_family != AF_INET) {
201 VLOG_DBG_RL(&rl, "received non AF_INET rtnetlink route message");
205 memset(change, 0, sizeof *change);
206 change->relevant = true;
208 if (rtm->rtm_scope == RT_SCOPE_NOWHERE) {
209 change->relevant = false;
212 if (rtm->rtm_type != RTN_UNICAST &&
213 rtm->rtm_type != RTN_LOCAL) {
214 change->relevant = false;
216 change->nlmsg_type = nlmsg->nlmsg_type;
217 change->rd.rtm_dst_len = rtm->rtm_dst_len;
218 rta_oif = nl_attr_get_u32(attrs[RTA_OIF]);
220 if (!if_indextoname(rta_oif, change->rd.ifname)) {
223 VLOG_DBG_RL(&rl, "Could not find interface name[%u]: %s",
224 rta_oif, ovs_strerror(error));
228 if (attrs[RTA_DST]) {
229 change->rd.rta_dst = nl_attr_get_be32(attrs[RTA_DST]);
231 if (attrs[RTA_GATEWAY]) {
232 change->rd.rta_gw = nl_attr_get_be32(attrs[RTA_GATEWAY]);
237 VLOG_DBG_RL(&rl, "received unparseable rtnetlink route message");
244 route_table_change(const struct route_table_msg *change OVS_UNUSED,
245 void *aux OVS_UNUSED)
247 route_table_valid = false;
251 route_table_handle_msg(const struct route_table_msg *change)
253 if (change->relevant && change->nlmsg_type == RTM_NEWROUTE) {
254 const struct route_data *rd = &change->rd;
256 ovs_router_insert(rd->rta_dst, rd->rtm_dst_len,
257 rd->ifname, rd->rta_gw);
262 route_map_clear(void)
271 name_table_init(void)
273 name_notifier = rtnetlink_link_notifier_create(name_table_change, NULL);
278 name_table_change(const struct rtnetlink_link_change *change OVS_UNUSED,
279 void *aux OVS_UNUSED)
281 /* Changes to interface status can cause routing table changes that some
282 * versions of the linux kernel do not advertise for some reason. */
283 route_table_valid = false;