lib/tnl-neigh-cache.c

   1 /*
   2  * Copyright (c) 2014, 2015 Nicira, Inc.
   3  *
   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:
   7  *
   8  *     http://www.apache.org/licenses/LICENSE-2.0
   9  *
  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.
  15  */
  16
  17 #include <config.h>
  18
  19 #include "tnl-neigh-cache.h"
  20
  21 #include <inttypes.h>
  22 #include <sys/types.h>
  23 #include <netinet/in.h>
  24 #include <netinet/icmp6.h>
  25 #include <stdlib.h>
  26
  27 #include "bitmap.h"
  28 #include "cmap.h"
  29 #include "coverage.h"
  30 #include "dpif-netdev.h"
  31 #include "dynamic-string.h"
  32 #include "errno.h"
  33 #include "flow.h"
  34 #include "netdev.h"
  35 #include "ovs-thread.h"
  36 #include "packets.h"
  37 #include "poll-loop.h"
  38 #include "seq.h"
  39 #include "socket-util.h"
  40 #include "timeval.h"
  41 #include "unaligned.h"
  42 #include "unixctl.h"
  43 #include "util.h"
  44 #include "openvswitch/vlog.h"
  45
  46
  47 /* In seconds */
  48 #define NEIGH_ENTRY_DEFAULT_IDLE_TIME  (15 * 60)
  49
  50 struct tnl_neigh_entry {
  51     struct cmap_node cmap_node;
  52     struct in6_addr ip;
  53     struct eth_addr mac;
  54     time_t expires;             /* Expiration time. */
  55     char br_name[IFNAMSIZ];
  56 };
  57
  58 static struct cmap table;
  59 static struct ovs_mutex mutex = OVS_MUTEX_INITIALIZER;
  60
  61 static uint32_t
  62 tnl_neigh_hash(const struct in6_addr *ip)
  63 {
  64     return hash_bytes(ip->s6_addr, 16, 0);
  65 }
  66
  67 static struct tnl_neigh_entry *
  68 tnl_neigh_lookup__(const char br_name[IFNAMSIZ], const struct in6_addr *dst)
  69 {
  70     struct tnl_neigh_entry *neigh;
  71     uint32_t hash;
  72
  73     hash = tnl_neigh_hash(dst);
  74     CMAP_FOR_EACH_WITH_HASH (neigh, cmap_node, hash, &table) {
  75         if (ipv6_addr_equals(&neigh->ip, dst) && !strcmp(neigh->br_name, br_name)) {
  76             neigh->expires = time_now() + NEIGH_ENTRY_DEFAULT_IDLE_TIME;
  77             return neigh;
  78         }
  79     }
  80     return NULL;
  81 }
  82
  83 int
  84 tnl_arp_lookup(const char br_name[IFNAMSIZ], ovs_be32 dst,
  85                struct eth_addr *mac)
  86 {
  87     struct tnl_neigh_entry *neigh;
  88     int res = ENOENT;
  89     struct in6_addr dst6 = in6_addr_mapped_ipv4(dst);
  90
  91     neigh = tnl_neigh_lookup__(br_name, &dst6);
  92     if (neigh) {
  93         *mac = neigh->mac;
  94         res = 0;
  95     }
  96
  97     return res;
  98 }
  99
 100 int
 101 tnl_neigh_lookup(const char br_name[IFNAMSIZ], const struct in6_addr *dst,
 102                  struct eth_addr *mac)
 103 {
 104     struct tnl_neigh_entry *neigh;
 105     int res = ENOENT;
 106
 107     neigh = tnl_neigh_lookup__(br_name, dst);
 108     if (neigh) {
 109         *mac = neigh->mac;
 110         res = 0;
 111     }
 112     return res;
 113 }
 114
 115 static void
 116 neigh_entry_free(struct tnl_neigh_entry *neigh)
 117 {
 118     free(neigh);
 119 }
 120
 121 static void
 122 tnl_neigh_delete(struct tnl_neigh_entry *neigh)
 123 {
 124     uint32_t hash = tnl_neigh_hash(&neigh->ip);
 125     cmap_remove(&table, &neigh->cmap_node, hash);
 126     ovsrcu_postpone(neigh_entry_free, neigh);
 127 }
 128
 129 static void
 130 tnl_neigh_set__(const char name[IFNAMSIZ], const struct in6_addr *dst,
 131               const struct eth_addr mac)
 132 {
 133     ovs_mutex_lock(&mutex);
 134     struct tnl_neigh_entry *neigh = tnl_neigh_lookup__(name, dst);
 135     if (neigh) {
 136         if (eth_addr_equals(neigh->mac, mac)) {
 137             neigh->expires = time_now() + NEIGH_ENTRY_DEFAULT_IDLE_TIME;
 138             ovs_mutex_unlock(&mutex);
 139             return;
 140         }
 141         tnl_neigh_delete(neigh);
 142         seq_change(tnl_conf_seq);
 143     }
 144
 145     neigh = xmalloc(sizeof *neigh);
 146
 147     neigh->ip = *dst;
 148     neigh->mac = mac;
 149     neigh->expires = time_now() + NEIGH_ENTRY_DEFAULT_IDLE_TIME;
 150     ovs_strlcpy(neigh->br_name, name, sizeof neigh->br_name);
 151     cmap_insert(&table, &neigh->cmap_node, tnl_neigh_hash(&neigh->ip));
 152     ovs_mutex_unlock(&mutex);
 153 }
 154
 155 static void
 156 tnl_arp_set(const char name[IFNAMSIZ], ovs_be32 dst,
 157             const struct eth_addr mac)
 158 {
 159     struct in6_addr dst6 = in6_addr_mapped_ipv4(dst);
 160     tnl_neigh_set__(name, &dst6, mac);
 161 }
 162
 163 static int
 164 tnl_arp_snoop(const struct flow *flow, struct flow_wildcards *wc,
 165               const char name[IFNAMSIZ])
 166 {
 167     if (flow->dl_type != htons(ETH_TYPE_ARP)) {
 168         return EINVAL;
 169     }
 170
 171     /* Exact Match on all ARP flows. */
 172     memset(&wc->masks.nw_proto, 0xff, sizeof wc->masks.nw_proto);
 173     memset(&wc->masks.nw_src, 0xff, sizeof wc->masks.nw_src);
 174     memset(&wc->masks.arp_sha, 0xff, sizeof wc->masks.arp_sha);
 175
 176     tnl_arp_set(name, flow->nw_src, flow->arp_sha);
 177     return 0;
 178 }
 179
 180 static int
 181 tnl_nd_snoop(const struct flow *flow, struct flow_wildcards *wc,
 182               const char name[IFNAMSIZ])
 183 {
 184     if (flow->dl_type != htons(ETH_TYPE_IPV6) ||
 185         flow->nw_proto != IPPROTO_ICMPV6 ||
 186         flow->tp_dst != htons(0) ||
 187         flow->tp_src != htons(ND_NEIGHBOR_ADVERT)) {
 188         return EINVAL;
 189     }
 190
 191     memset(&wc->masks.ipv6_src, 0xff, sizeof wc->masks.ipv6_src);
 192     memset(&wc->masks.ipv6_dst, 0xff, sizeof wc->masks.ipv6_dst);
 193     memset(&wc->masks.nd_target, 0xff, sizeof wc->masks.nd_target);
 194     memset(&wc->masks.arp_tha, 0xff, sizeof wc->masks.arp_tha);
 195
 196     tnl_neigh_set__(name, &flow->nd_target, flow->arp_tha);
 197     return 0;
 198 }
 199
 200 int
 201 tnl_neigh_snoop(const struct flow *flow, struct flow_wildcards *wc,
 202                 const char name[IFNAMSIZ])
 203 {
 204     int res;
 205     res = tnl_arp_snoop(flow, wc, name);
 206     if (res != EINVAL) {
 207         return res;
 208     }
 209     return tnl_nd_snoop(flow, wc, name);
 210 }
 211
 212 void
 213 tnl_neigh_cache_run(void)
 214 {
 215     struct tnl_neigh_entry *neigh;
 216     bool changed = false;
 217
 218     ovs_mutex_lock(&mutex);
 219     CMAP_FOR_EACH(neigh, cmap_node, &table) {
 220         if (neigh->expires <= time_now()) {
 221             tnl_neigh_delete(neigh);
 222             changed = true;
 223         }
 224     }
 225     ovs_mutex_unlock(&mutex);
 226
 227     if (changed) {
 228         seq_change(tnl_conf_seq);
 229     }
 230 }
 231
 232 static void
 233 tnl_neigh_cache_flush(struct unixctl_conn *conn, int argc OVS_UNUSED,
 234                     const char *argv[] OVS_UNUSED, void *aux OVS_UNUSED)
 235 {
 236     struct tnl_neigh_entry *neigh;
 237     bool changed = false;
 238
 239     ovs_mutex_lock(&mutex);
 240     CMAP_FOR_EACH(neigh, cmap_node, &table) {
 241         tnl_neigh_delete(neigh);
 242         changed = true;
 243     }
 244     ovs_mutex_unlock(&mutex);
 245     if (changed) {
 246         seq_change(tnl_conf_seq);
 247     }
 248     unixctl_command_reply(conn, "OK");
 249 }
 250
 251 static int
 252 lookup_any(const char *host_name, struct in6_addr *address)
 253 {
 254     if (addr_is_ipv6(host_name)) {
 255         return lookup_ipv6(host_name, address);
 256     } else {
 257         int r;
 258         struct in_addr ip;
 259         r = lookup_ip(host_name, &ip);
 260         if (r == 0) {
 261             in6_addr_set_mapped_ipv4(address, ip.s_addr);
 262         }
 263         return r;
 264     }
 265     return ENOENT;
 266 }
 267
 268 static void
 269 tnl_neigh_cache_add(struct unixctl_conn *conn, int argc OVS_UNUSED,
 270                     const char *argv[], void *aux OVS_UNUSED)
 271 {
 272     const char *br_name = argv[1];
 273     struct eth_addr mac;
 274     struct in6_addr ip6;
 275
 276     if (lookup_any(argv[2], &ip6) != 0) {
 277         unixctl_command_reply_error(conn, "bad IP address");
 278         return;
 279     }
 280
 281     if (!eth_addr_from_string(argv[3], &mac)) {
 282         unixctl_command_reply_error(conn, "bad MAC address");
 283         return;
 284     }
 285
 286     tnl_neigh_set__(br_name, &ip6, mac);
 287     unixctl_command_reply(conn, "OK");
 288 }
 289
 290 static void
 291 tnl_neigh_cache_show(struct unixctl_conn *conn, int argc OVS_UNUSED,
 292                      const char *argv[] OVS_UNUSED, void *aux OVS_UNUSED)
 293 {
 294     struct ds ds = DS_EMPTY_INITIALIZER;
 295     struct tnl_neigh_entry *neigh;
 296
 297     ds_put_cstr(&ds, "IP                                            MAC                 Bridge\n");
 298     ds_put_cstr(&ds, "==========================================================================\n");
 299     ovs_mutex_lock(&mutex);
 300     CMAP_FOR_EACH(neigh, cmap_node, &table) {
 301         int start_len, need_ws;
 302
 303         start_len = ds.length;
 304         ipv6_format_mapped(&neigh->ip, &ds);
 305
 306         need_ws = INET6_ADDRSTRLEN - (ds.length - start_len);
 307         ds_put_char_multiple(&ds, ' ', need_ws);
 308
 309         ds_put_format(&ds, ETH_ADDR_FMT"   %s\n",
 310                       ETH_ADDR_ARGS(neigh->mac), neigh->br_name);
 311
 312     }
 313     ovs_mutex_unlock(&mutex);
 314     unixctl_command_reply(conn, ds_cstr(&ds));
 315     ds_destroy(&ds);
 316 }
 317
 318 void
 319 tnl_neigh_cache_init(void)
 320 {
 321     cmap_init(&table);
 322
 323     unixctl_command_register("tnl/arp/show", "", 0, 0, tnl_neigh_cache_show, NULL);
 324     unixctl_command_register("tnl/arp/set", "BRIDGE IP MAC", 3, 3, tnl_neigh_cache_add, NULL);
 325     unixctl_command_register("tnl/arp/flush", "", 0, 0, tnl_neigh_cache_flush, NULL);
 326     unixctl_command_register("tnl/neigh/show", "", 0, 0, tnl_neigh_cache_show, NULL);
 327     unixctl_command_register("tnl/neigh/set", "BRIDGE IP MAC", 3, 3, tnl_neigh_cache_add, NULL);
 328     unixctl_command_register("tnl/neigh/flush", "", 0, 0, tnl_neigh_cache_flush, NULL);
 329 }