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;
  90
  91     in6_addr_set_mapped_ipv4(&dst6, dst);
  92
  93     neigh = tnl_neigh_lookup__(br_name, &dst6);
  94     if (neigh) {
  95         *mac = neigh->mac;
  96         res = 0;
  97     }
  98
  99     return res;
 100 }
 101
 102 int
 103 tnl_neigh_lookup(const char br_name[IFNAMSIZ], const struct in6_addr *dst,
 104                  struct eth_addr *mac)
 105 {
 106     struct tnl_neigh_entry *neigh;
 107     int res = ENOENT;
 108
 109     neigh = tnl_neigh_lookup__(br_name, dst);
 110     if (neigh) {
 111         *mac = neigh->mac;
 112         res = 0;
 113     }
 114     return res;
 115 }
 116
 117 static void
 118 neigh_entry_free(struct tnl_neigh_entry *neigh)
 119 {
 120     free(neigh);
 121 }
 122
 123 static void
 124 tnl_neigh_delete(struct tnl_neigh_entry *neigh)
 125 {
 126     uint32_t hash = tnl_neigh_hash(&neigh->ip);
 127     cmap_remove(&table, &neigh->cmap_node, hash);
 128     ovsrcu_postpone(neigh_entry_free, neigh);
 129 }
 130
 131 static void
 132 tnl_neigh_set__(const char name[IFNAMSIZ], const struct in6_addr *dst,
 133               const struct eth_addr mac)
 134 {
 135     ovs_mutex_lock(&mutex);
 136     struct tnl_neigh_entry *neigh = tnl_neigh_lookup__(name, dst);
 137     if (neigh) {
 138         if (eth_addr_equals(neigh->mac, mac)) {
 139             neigh->expires = time_now() + NEIGH_ENTRY_DEFAULT_IDLE_TIME;
 140             ovs_mutex_unlock(&mutex);
 141             return;
 142         }
 143         tnl_neigh_delete(neigh);
 144         seq_change(tnl_conf_seq);
 145     }
 146
 147     neigh = xmalloc(sizeof *neigh);
 148
 149     neigh->ip = *dst;
 150     neigh->mac = mac;
 151     neigh->expires = time_now() + NEIGH_ENTRY_DEFAULT_IDLE_TIME;
 152     ovs_strlcpy(neigh->br_name, name, sizeof neigh->br_name);
 153     cmap_insert(&table, &neigh->cmap_node, tnl_neigh_hash(&neigh->ip));
 154     ovs_mutex_unlock(&mutex);
 155 }
 156
 157 static void
 158 tnl_arp_set(const char name[IFNAMSIZ], ovs_be32 dst,
 159             const struct eth_addr mac)
 160 {
 161     struct in6_addr dst6;
 162
 163     in6_addr_set_mapped_ipv4(&dst6, dst);
 164     tnl_neigh_set__(name, &dst6, mac);
 165 }
 166
 167 static int
 168 tnl_arp_snoop(const struct flow *flow, struct flow_wildcards *wc,
 169               const char name[IFNAMSIZ])
 170 {
 171     if (flow->dl_type != htons(ETH_TYPE_ARP)) {
 172         return EINVAL;
 173     }
 174
 175     /* Exact Match on all ARP flows. */
 176     memset(&wc->masks.nw_proto, 0xff, sizeof wc->masks.nw_proto);
 177     memset(&wc->masks.nw_src, 0xff, sizeof wc->masks.nw_src);
 178     memset(&wc->masks.arp_sha, 0xff, sizeof wc->masks.arp_sha);
 179
 180     tnl_arp_set(name, flow->nw_src, flow->arp_sha);
 181     return 0;
 182 }
 183
 184 static int
 185 tnl_nd_snoop(const struct flow *flow, struct flow_wildcards *wc,
 186               const char name[IFNAMSIZ])
 187 {
 188     if (flow->dl_type != htons(ETH_TYPE_IPV6) ||
 189         flow->nw_proto != IPPROTO_ICMPV6 ||
 190         flow->tp_dst != htons(0) ||
 191         flow->tp_src != htons(ND_NEIGHBOR_ADVERT)) {
 192         return EINVAL;
 193     }
 194
 195     memset(&wc->masks.ipv6_src, 0xff, sizeof wc->masks.ipv6_src);
 196     memset(&wc->masks.ipv6_dst, 0xff, sizeof wc->masks.ipv6_dst);
 197     memset(&wc->masks.nd_target, 0xff, sizeof wc->masks.nd_target);
 198     memset(&wc->masks.arp_tha, 0xff, sizeof wc->masks.arp_tha);
 199
 200     tnl_neigh_set__(name, &flow->nd_target, flow->arp_tha);
 201     return 0;
 202 }
 203
 204 int
 205 tnl_neigh_snoop(const struct flow *flow, struct flow_wildcards *wc,
 206                 const char name[IFNAMSIZ])
 207 {
 208     int res;
 209     res = tnl_arp_snoop(flow, wc, name);
 210     if (res != EINVAL) {
 211         return res;
 212     }
 213     return tnl_nd_snoop(flow, wc, name);
 214 }
 215
 216 void
 217 tnl_neigh_cache_run(void)
 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         if (neigh->expires <= time_now()) {
 225             tnl_neigh_delete(neigh);
 226             changed = true;
 227         }
 228     }
 229     ovs_mutex_unlock(&mutex);
 230
 231     if (changed) {
 232         seq_change(tnl_conf_seq);
 233     }
 234 }
 235
 236 static void
 237 tnl_neigh_cache_flush(struct unixctl_conn *conn, int argc OVS_UNUSED,
 238                     const char *argv[] OVS_UNUSED, void *aux OVS_UNUSED)
 239 {
 240     struct tnl_neigh_entry *neigh;
 241     bool changed = false;
 242
 243     ovs_mutex_lock(&mutex);
 244     CMAP_FOR_EACH(neigh, cmap_node, &table) {
 245         tnl_neigh_delete(neigh);
 246         changed = true;
 247     }
 248     ovs_mutex_unlock(&mutex);
 249     if (changed) {
 250         seq_change(tnl_conf_seq);
 251     }
 252     unixctl_command_reply(conn, "OK");
 253 }
 254
 255 static int
 256 lookup_any(const char *host_name, struct in6_addr *address)
 257 {
 258     if (addr_is_ipv6(host_name)) {
 259         return lookup_ipv6(host_name, address);
 260     } else {
 261         int r;
 262         struct in_addr ip;
 263         r = lookup_ip(host_name, &ip);
 264         if (r == 0) {
 265             in6_addr_set_mapped_ipv4(address, ip.s_addr);
 266         }
 267         return r;
 268     }
 269     return ENOENT;
 270 }
 271
 272 static void
 273 tnl_neigh_cache_add(struct unixctl_conn *conn, int argc OVS_UNUSED,
 274                     const char *argv[], void *aux OVS_UNUSED)
 275 {
 276     const char *br_name = argv[1];
 277     struct eth_addr mac;
 278     struct in6_addr ip6;
 279
 280     if (lookup_any(argv[2], &ip6) != 0) {
 281         unixctl_command_reply_error(conn, "bad IP address");
 282         return;
 283     }
 284
 285     if (!eth_addr_from_string(argv[3], &mac)) {
 286         unixctl_command_reply_error(conn, "bad MAC address");
 287         return;
 288     }
 289
 290     tnl_neigh_set__(br_name, &ip6, mac);
 291     unixctl_command_reply(conn, "OK");
 292 }
 293
 294 static void
 295 tnl_neigh_cache_show(struct unixctl_conn *conn, int argc OVS_UNUSED,
 296                      const char *argv[] OVS_UNUSED, void *aux OVS_UNUSED)
 297 {
 298     struct ds ds = DS_EMPTY_INITIALIZER;
 299     struct tnl_neigh_entry *neigh;
 300
 301     ds_put_cstr(&ds, "IP                                            MAC                 Bridge\n");
 302     ds_put_cstr(&ds, "==========================================================================\n");
 303     ovs_mutex_lock(&mutex);
 304     CMAP_FOR_EACH(neigh, cmap_node, &table) {
 305         int start_len, need_ws;
 306
 307         start_len = ds.length;
 308         ipv6_format_mapped(&neigh->ip, &ds);
 309
 310         need_ws = INET6_ADDRSTRLEN - (ds.length - start_len);
 311         ds_put_char_multiple(&ds, ' ', need_ws);
 312
 313         ds_put_format(&ds, ETH_ADDR_FMT"   %s\n",
 314                       ETH_ADDR_ARGS(neigh->mac), neigh->br_name);
 315
 316     }
 317     ovs_mutex_unlock(&mutex);
 318     unixctl_command_reply(conn, ds_cstr(&ds));
 319     ds_destroy(&ds);
 320 }
 321
 322 void
 323 tnl_neigh_cache_init(void)
 324 {
 325     cmap_init(&table);
 326
 327     unixctl_command_register("tnl/arp/show", "", 0, 0, tnl_neigh_cache_show, NULL);
 328     unixctl_command_register("tnl/arp/set", "BRIDGE IP MAC", 3, 3, tnl_neigh_cache_add, NULL);
 329     unixctl_command_register("tnl/arp/flush", "", 0, 0, tnl_neigh_cache_flush, NULL);
 330     unixctl_command_register("tnl/neigh/show", "", 0, 0, tnl_neigh_cache_show, NULL);
 331     unixctl_command_register("tnl/neigh/set", "BRIDGE IP MAC", 3, 3, tnl_neigh_cache_add, NULL);
 332     unixctl_command_register("tnl/neigh/flush", "", 0, 0, tnl_neigh_cache_flush, NULL);
 333 }