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_neigh_lookup(const char br_name[IFNAMSIZ], const struct in6_addr *dst,
  85                  struct eth_addr *mac)
  86 {
  87     struct tnl_neigh_entry *neigh;
  88     int res = ENOENT;
  89
  90     neigh = tnl_neigh_lookup__(br_name, dst);
  91     if (neigh) {
  92         *mac = neigh->mac;
  93         res = 0;
  94     }
  95     return res;
  96 }
  97
  98 static void
  99 neigh_entry_free(struct tnl_neigh_entry *neigh)
 100 {
 101     free(neigh);
 102 }
 103
 104 static void
 105 tnl_neigh_delete(struct tnl_neigh_entry *neigh)
 106 {
 107     uint32_t hash = tnl_neigh_hash(&neigh->ip);
 108     cmap_remove(&table, &neigh->cmap_node, hash);
 109     ovsrcu_postpone(neigh_entry_free, neigh);
 110 }
 111
 112 static void
 113 tnl_neigh_set__(const char name[IFNAMSIZ], const struct in6_addr *dst,
 114               const struct eth_addr mac)
 115 {
 116     ovs_mutex_lock(&mutex);
 117     struct tnl_neigh_entry *neigh = tnl_neigh_lookup__(name, dst);
 118     if (neigh) {
 119         if (eth_addr_equals(neigh->mac, mac)) {
 120             neigh->expires = time_now() + NEIGH_ENTRY_DEFAULT_IDLE_TIME;
 121             ovs_mutex_unlock(&mutex);
 122             return;
 123         }
 124         tnl_neigh_delete(neigh);
 125         seq_change(tnl_conf_seq);
 126     }
 127
 128     neigh = xmalloc(sizeof *neigh);
 129
 130     neigh->ip = *dst;
 131     neigh->mac = mac;
 132     neigh->expires = time_now() + NEIGH_ENTRY_DEFAULT_IDLE_TIME;
 133     ovs_strlcpy(neigh->br_name, name, sizeof neigh->br_name);
 134     cmap_insert(&table, &neigh->cmap_node, tnl_neigh_hash(&neigh->ip));
 135     ovs_mutex_unlock(&mutex);
 136 }
 137
 138 static void
 139 tnl_arp_set(const char name[IFNAMSIZ], ovs_be32 dst,
 140             const struct eth_addr mac)
 141 {
 142     struct in6_addr dst6 = in6_addr_mapped_ipv4(dst);
 143     tnl_neigh_set__(name, &dst6, mac);
 144 }
 145
 146 static int
 147 tnl_arp_snoop(const struct flow *flow, struct flow_wildcards *wc,
 148               const char name[IFNAMSIZ])
 149 {
 150     if (flow->dl_type != htons(ETH_TYPE_ARP)) {
 151         return EINVAL;
 152     }
 153
 154     /* Exact Match on all ARP flows. */
 155     memset(&wc->masks.nw_proto, 0xff, sizeof wc->masks.nw_proto);
 156     memset(&wc->masks.nw_src, 0xff, sizeof wc->masks.nw_src);
 157     memset(&wc->masks.arp_sha, 0xff, sizeof wc->masks.arp_sha);
 158
 159     tnl_arp_set(name, flow->nw_src, flow->arp_sha);
 160     return 0;
 161 }
 162
 163 static int
 164 tnl_nd_snoop(const struct flow *flow, struct flow_wildcards *wc,
 165               const char name[IFNAMSIZ])
 166 {
 167     if (flow->dl_type != htons(ETH_TYPE_IPV6) ||
 168         flow->nw_proto != IPPROTO_ICMPV6 ||
 169         flow->tp_dst != htons(0) ||
 170         flow->tp_src != htons(ND_NEIGHBOR_ADVERT)) {
 171         return EINVAL;
 172     }
 173
 174     memset(&wc->masks.ipv6_src, 0xff, sizeof wc->masks.ipv6_src);
 175     memset(&wc->masks.ipv6_dst, 0xff, sizeof wc->masks.ipv6_dst);
 176     memset(&wc->masks.nd_target, 0xff, sizeof wc->masks.nd_target);
 177     memset(&wc->masks.arp_tha, 0xff, sizeof wc->masks.arp_tha);
 178
 179     tnl_neigh_set__(name, &flow->nd_target, flow->arp_tha);
 180     return 0;
 181 }
 182
 183 int
 184 tnl_neigh_snoop(const struct flow *flow, struct flow_wildcards *wc,
 185                 const char name[IFNAMSIZ])
 186 {
 187     int res;
 188     res = tnl_arp_snoop(flow, wc, name);
 189     if (res != EINVAL) {
 190         return res;
 191     }
 192     return tnl_nd_snoop(flow, wc, name);
 193 }
 194
 195 void
 196 tnl_neigh_cache_run(void)
 197 {
 198     struct tnl_neigh_entry *neigh;
 199     bool changed = false;
 200
 201     ovs_mutex_lock(&mutex);
 202     CMAP_FOR_EACH(neigh, cmap_node, &table) {
 203         if (neigh->expires <= time_now()) {
 204             tnl_neigh_delete(neigh);
 205             changed = true;
 206         }
 207     }
 208     ovs_mutex_unlock(&mutex);
 209
 210     if (changed) {
 211         seq_change(tnl_conf_seq);
 212     }
 213 }
 214
 215 static void
 216 tnl_neigh_cache_flush(struct unixctl_conn *conn, int argc OVS_UNUSED,
 217                     const char *argv[] OVS_UNUSED, void *aux OVS_UNUSED)
 218 {
 219     struct tnl_neigh_entry *neigh;
 220     bool changed = false;
 221
 222     ovs_mutex_lock(&mutex);
 223     CMAP_FOR_EACH(neigh, cmap_node, &table) {
 224         tnl_neigh_delete(neigh);
 225         changed = true;
 226     }
 227     ovs_mutex_unlock(&mutex);
 228     if (changed) {
 229         seq_change(tnl_conf_seq);
 230     }
 231     unixctl_command_reply(conn, "OK");
 232 }
 233
 234 static int
 235 lookup_any(const char *host_name, struct in6_addr *address)
 236 {
 237     if (addr_is_ipv6(host_name)) {
 238         return lookup_ipv6(host_name, address);
 239     } else {
 240         int r;
 241         struct in_addr ip;
 242         r = lookup_ip(host_name, &ip);
 243         if (r == 0) {
 244             in6_addr_set_mapped_ipv4(address, ip.s_addr);
 245         }
 246         return r;
 247     }
 248     return ENOENT;
 249 }
 250
 251 static void
 252 tnl_neigh_cache_add(struct unixctl_conn *conn, int argc OVS_UNUSED,
 253                     const char *argv[], void *aux OVS_UNUSED)
 254 {
 255     const char *br_name = argv[1];
 256     struct eth_addr mac;
 257     struct in6_addr ip6;
 258
 259     if (lookup_any(argv[2], &ip6) != 0) {
 260         unixctl_command_reply_error(conn, "bad IP address");
 261         return;
 262     }
 263
 264     if (!eth_addr_from_string(argv[3], &mac)) {
 265         unixctl_command_reply_error(conn, "bad MAC address");
 266         return;
 267     }
 268
 269     tnl_neigh_set__(br_name, &ip6, mac);
 270     unixctl_command_reply(conn, "OK");
 271 }
 272
 273 static void
 274 tnl_neigh_cache_show(struct unixctl_conn *conn, int argc OVS_UNUSED,
 275                      const char *argv[] OVS_UNUSED, void *aux OVS_UNUSED)
 276 {
 277     struct ds ds = DS_EMPTY_INITIALIZER;
 278     struct tnl_neigh_entry *neigh;
 279
 280     ds_put_cstr(&ds, "IP                                            MAC                 Bridge\n");
 281     ds_put_cstr(&ds, "==========================================================================\n");
 282     ovs_mutex_lock(&mutex);
 283     CMAP_FOR_EACH(neigh, cmap_node, &table) {
 284         int start_len, need_ws;
 285
 286         start_len = ds.length;
 287         ipv6_format_mapped(&neigh->ip, &ds);
 288
 289         need_ws = INET6_ADDRSTRLEN - (ds.length - start_len);
 290         ds_put_char_multiple(&ds, ' ', need_ws);
 291
 292         ds_put_format(&ds, ETH_ADDR_FMT"   %s\n",
 293                       ETH_ADDR_ARGS(neigh->mac), neigh->br_name);
 294
 295     }
 296     ovs_mutex_unlock(&mutex);
 297     unixctl_command_reply(conn, ds_cstr(&ds));
 298     ds_destroy(&ds);
 299 }
 300
 301 void
 302 tnl_neigh_cache_init(void)
 303 {
 304     cmap_init(&table);
 305
 306     unixctl_command_register("tnl/arp/show", "", 0, 0, tnl_neigh_cache_show, NULL);
 307     unixctl_command_register("tnl/arp/set", "BRIDGE IP MAC", 3, 3, tnl_neigh_cache_add, NULL);
 308     unixctl_command_register("tnl/arp/flush", "", 0, 0, tnl_neigh_cache_flush, NULL);
 309     unixctl_command_register("tnl/neigh/show", "", 0, 0, tnl_neigh_cache_show, NULL);
 310     unixctl_command_register("tnl/neigh/set", "BRIDGE IP MAC", 3, 3, tnl_neigh_cache_add, NULL);
 311     unixctl_command_register("tnl/neigh/flush", "", 0, 0, tnl_neigh_cache_flush, NULL);
 312 }