lib/tnl-neigh-cache.c

   1 /*
   2  * Copyright (c) 2014, 2015, 2016 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 "openvswitch/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 = CMAP_INITIALIZER;
  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         flow->nw_proto != ARP_OP_REPLY ||
 152         eth_addr_is_zero(flow->arp_sha)) {
 153         return EINVAL;
 154     }
 155
 156     /* Exact Match on all ARP flows. */
 157     memset(&wc->masks.nw_proto, 0xff, sizeof wc->masks.nw_proto);
 158     memset(&wc->masks.nw_src, 0xff, sizeof wc->masks.nw_src);
 159     memset(&wc->masks.arp_sha, 0xff, sizeof wc->masks.arp_sha);
 160
 161     tnl_arp_set(name, flow->nw_src, flow->arp_sha);
 162     return 0;
 163 }
 164
 165 static int
 166 tnl_nd_snoop(const struct flow *flow, struct flow_wildcards *wc,
 167               const char name[IFNAMSIZ])
 168 {
 169     if (flow->dl_type != htons(ETH_TYPE_IPV6) ||
 170         flow->nw_proto != IPPROTO_ICMPV6 ||
 171         flow->tp_dst != htons(0) ||
 172         flow->tp_src != htons(ND_NEIGHBOR_ADVERT)) {
 173         return EINVAL;
 174     }
 175     /* - RFC4861 says Neighbor Advertisements sent in response to unicast Neighbor
 176      *   Solicitations SHOULD include the Target link-layer address. However, Linux
 177      *   doesn't. So, the response to Solicitations sent by OVS will include the
 178      *   TLL address and other Advertisements not including it can be ignored.
 179      * - OVS flow extract can set this field to zero in case of packet parsing errors.
 180      *   For details refer miniflow_extract()*/
 181     if (eth_addr_is_zero(flow->arp_tha)) {
 182         return EINVAL;
 183     }
 184
 185     memset(&wc->masks.ipv6_src, 0xff, sizeof wc->masks.ipv6_src);
 186     memset(&wc->masks.ipv6_dst, 0xff, sizeof wc->masks.ipv6_dst);
 187     memset(&wc->masks.nd_target, 0xff, sizeof wc->masks.nd_target);
 188     memset(&wc->masks.arp_tha, 0xff, sizeof wc->masks.arp_tha);
 189
 190     tnl_neigh_set__(name, &flow->nd_target, flow->arp_tha);
 191     return 0;
 192 }
 193
 194 int
 195 tnl_neigh_snoop(const struct flow *flow, struct flow_wildcards *wc,
 196                 const char name[IFNAMSIZ])
 197 {
 198     int res;
 199     res = tnl_arp_snoop(flow, wc, name);
 200     if (res != EINVAL) {
 201         return res;
 202     }
 203     return tnl_nd_snoop(flow, wc, name);
 204 }
 205
 206 void
 207 tnl_neigh_cache_run(void)
 208 {
 209     struct tnl_neigh_entry *neigh;
 210     bool changed = false;
 211
 212     ovs_mutex_lock(&mutex);
 213     CMAP_FOR_EACH(neigh, cmap_node, &table) {
 214         if (neigh->expires <= time_now()) {
 215             tnl_neigh_delete(neigh);
 216             changed = true;
 217         }
 218     }
 219     ovs_mutex_unlock(&mutex);
 220
 221     if (changed) {
 222         seq_change(tnl_conf_seq);
 223     }
 224 }
 225
 226 static void
 227 tnl_neigh_cache_flush(struct unixctl_conn *conn, int argc OVS_UNUSED,
 228                     const char *argv[] OVS_UNUSED, void *aux OVS_UNUSED)
 229 {
 230     struct tnl_neigh_entry *neigh;
 231     bool changed = false;
 232
 233     ovs_mutex_lock(&mutex);
 234     CMAP_FOR_EACH(neigh, cmap_node, &table) {
 235         tnl_neigh_delete(neigh);
 236         changed = true;
 237     }
 238     ovs_mutex_unlock(&mutex);
 239     if (changed) {
 240         seq_change(tnl_conf_seq);
 241     }
 242     unixctl_command_reply(conn, "OK");
 243 }
 244
 245 static int
 246 lookup_any(const char *host_name, struct in6_addr *address)
 247 {
 248     if (addr_is_ipv6(host_name)) {
 249         return lookup_ipv6(host_name, address);
 250     } else {
 251         int r;
 252         struct in_addr ip;
 253         r = lookup_ip(host_name, &ip);
 254         if (r == 0) {
 255             in6_addr_set_mapped_ipv4(address, ip.s_addr);
 256         }
 257         return r;
 258     }
 259     return ENOENT;
 260 }
 261
 262 static void
 263 tnl_neigh_cache_add(struct unixctl_conn *conn, int argc OVS_UNUSED,
 264                     const char *argv[], void *aux OVS_UNUSED)
 265 {
 266     const char *br_name = argv[1];
 267     struct eth_addr mac;
 268     struct in6_addr ip6;
 269
 270     if (lookup_any(argv[2], &ip6) != 0) {
 271         unixctl_command_reply_error(conn, "bad IP address");
 272         return;
 273     }
 274
 275     if (!eth_addr_from_string(argv[3], &mac)) {
 276         unixctl_command_reply_error(conn, "bad MAC address");
 277         return;
 278     }
 279
 280     tnl_neigh_set__(br_name, &ip6, mac);
 281     unixctl_command_reply(conn, "OK");
 282 }
 283
 284 static void
 285 tnl_neigh_cache_show(struct unixctl_conn *conn, int argc OVS_UNUSED,
 286                      const char *argv[] OVS_UNUSED, void *aux OVS_UNUSED)
 287 {
 288     struct ds ds = DS_EMPTY_INITIALIZER;
 289     struct tnl_neigh_entry *neigh;
 290
 291     ds_put_cstr(&ds, "IP                                            MAC                 Bridge\n");
 292     ds_put_cstr(&ds, "==========================================================================\n");
 293     ovs_mutex_lock(&mutex);
 294     CMAP_FOR_EACH(neigh, cmap_node, &table) {
 295         int start_len, need_ws;
 296
 297         start_len = ds.length;
 298         ipv6_format_mapped(&neigh->ip, &ds);
 299
 300         need_ws = INET6_ADDRSTRLEN - (ds.length - start_len);
 301         ds_put_char_multiple(&ds, ' ', need_ws);
 302
 303         ds_put_format(&ds, ETH_ADDR_FMT"   %s\n",
 304                       ETH_ADDR_ARGS(neigh->mac), neigh->br_name);
 305
 306     }
 307     ovs_mutex_unlock(&mutex);
 308     unixctl_command_reply(conn, ds_cstr(&ds));
 309     ds_destroy(&ds);
 310 }
 311
 312 void
 313 tnl_neigh_cache_init(void)
 314 {
 315     unixctl_command_register("tnl/arp/show", "", 0, 0, tnl_neigh_cache_show, NULL);
 316     unixctl_command_register("tnl/arp/set", "BRIDGE IP MAC", 3, 3, tnl_neigh_cache_add, NULL);
 317     unixctl_command_register("tnl/arp/flush", "", 0, 0, tnl_neigh_cache_flush, NULL);
 318     unixctl_command_register("tnl/neigh/show", "", 0, 0, tnl_neigh_cache_show, NULL);
 319     unixctl_command_register("tnl/neigh/set", "BRIDGE IP MAC", 3, 3, tnl_neigh_cache_add, NULL);
 320     unixctl_command_register("tnl/neigh/flush", "", 0, 0, tnl_neigh_cache_flush, NULL);
 321 }