ofproto/tunnel.c

   1 /* Copyright (c) 2013 Nicira, Inc.
   2  *
   3  * Licensed under the Apache License, Version 2.0 (the "License");
   4  * you may not use this file except in compliance with the License.
   5  * You may obtain a copy of the License at:
   6  *
   7  *     http://www.apache.org/licenses/LICENSE-2.0
   8  *
   9  * Unless required by applicable law or agreed to in writing, software
  10  * distributed under the License is distributed on an "AS IS" BASIS,
  11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12  * See the License for the specific language governing permissions and
  13  * limitations under the License. */
  14
  15 #include <config.h>
  16 #include "tunnel.h"
  17
  18 #include <errno.h>
  19
  20 #include "ofproto/ofproto-provider.h"
  21 #include "byte-order.h"
  22 #include "dynamic-string.h"
  23 #include "hash.h"
  24 #include "hmap.h"
  25 #include "netdev-vport.h"
  26 #include "odp-util.h"
  27 #include "packets.h"
  28 #include "smap.h"
  29 #include "socket-util.h"
  30 #include "tunnel.h"
  31 #include "vlog.h"
  32
  33 /* XXX:
  34  *
  35  * Ability to generate metadata for packet-outs
  36  * Disallow netdevs with names like "gre64_system" to prevent collisions. */
  37
  38 VLOG_DEFINE_THIS_MODULE(tunnel);
  39
  40 /* skb mark used for IPsec tunnel packets */
  41 #define IPSEC_MARK 1
  42
  43 struct tnl_match {
  44     ovs_be64 in_key;
  45     ovs_be32 ip_src;
  46     ovs_be32 ip_dst;
  47     uint32_t odp_port;
  48     uint32_t skb_mark;
  49     bool in_key_flow;
  50 };
  51
  52 struct tnl_port {
  53     struct hmap_node match_node;
  54
  55     const struct ofport *ofport;
  56     unsigned int netdev_seq;
  57     struct tnl_match match;
  58 };
  59
  60 static struct hmap tnl_match_map = HMAP_INITIALIZER(&tnl_match_map);
  61
  62 /* Returned to callers when their ofport will never be used to receive or send
  63  * tunnel traffic. Alternatively, we could ask the caller to delete their
  64  * ofport, but this would be unclean in the reconfguration case.  For the first
  65  * time, an ofproto provider would have to call ofproto_port_del() on itself.*/
  66 static struct tnl_port void_tnl_port;
  67
  68 static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 5);
  69 static struct vlog_rate_limit dbg_rl = VLOG_RATE_LIMIT_INIT(60, 60);
  70
  71 static struct tnl_port *tnl_find(struct tnl_match *);
  72 static struct tnl_port *tnl_find_exact(struct tnl_match *);
  73 static uint32_t tnl_hash(struct tnl_match *);
  74 static void tnl_match_fmt(const struct tnl_match *, struct ds *);
  75 static char *tnl_port_fmt(const struct tnl_port *);
  76 static void tnl_port_mod_log(const struct tnl_port *, const char *action);
  77 static const char *tnl_port_get_name(const struct tnl_port *);
  78
  79 static struct tnl_port *
  80 tnl_port_add__(const struct ofport *ofport, uint32_t odp_port,
  81                bool warn)
  82 {
  83     const struct netdev_tunnel_config *cfg;
  84     struct tnl_port *existing_port;
  85     struct tnl_port *tnl_port;
  86
  87     cfg = netdev_get_tunnel_config(ofport->netdev);
  88     ovs_assert(cfg);
  89
  90     tnl_port = xzalloc(sizeof *tnl_port);
  91     tnl_port->ofport = ofport;
  92     tnl_port->netdev_seq = netdev_change_seq(tnl_port->ofport->netdev);
  93
  94     tnl_port->match.in_key = cfg->in_key;
  95     tnl_port->match.ip_src = cfg->ip_src;
  96     tnl_port->match.ip_dst = cfg->ip_dst;
  97     tnl_port->match.skb_mark = cfg->ipsec ? IPSEC_MARK : 0;
  98     tnl_port->match.in_key_flow = cfg->in_key_flow;
  99     tnl_port->match.odp_port = odp_port;
 100
 101     existing_port = tnl_find_exact(&tnl_port->match);
 102     if (existing_port) {
 103         if (warn) {
 104             struct ds ds = DS_EMPTY_INITIALIZER;
 105             tnl_match_fmt(&tnl_port->match, &ds);
 106             VLOG_WARN("%s: attempting to add tunnel port with same config as "
 107                       "port '%s' (%s)", tnl_port_get_name(tnl_port),
 108                       tnl_port_get_name(existing_port), ds_cstr(&ds));
 109             ds_destroy(&ds);
 110             free(tnl_port);
 111         }
 112         return &void_tnl_port;
 113     }
 114
 115     hmap_insert(&tnl_match_map, &tnl_port->match_node,
 116                 tnl_hash(&tnl_port->match));
 117     tnl_port_mod_log(tnl_port, "adding");
 118     return tnl_port;
 119 }
 120
 121 /* Adds 'ofport' to the module with datapath port number 'odp_port'. 'ofport's
 122  * must be added before they can be used by the module. 'ofport' must be a
 123  * tunnel. */
 124 struct tnl_port *
 125 tnl_port_add(const struct ofport *ofport, uint32_t odp_port)
 126 {
 127     return tnl_port_add__(ofport, odp_port, true);
 128 }
 129
 130 /* Checks if the tnl_port pointed to by 'tnl_portp' needs reconfiguration due
 131  * to changes in its netdev_tunnel_config.  If it does, updates 'tnl_portp' to
 132  * point to a new tnl_port and returns true.  Otherwise, returns false.
 133  * 'ofport' and 'odp_port' should be the same as would be passed to
 134  * tnl_port_add(). */
 135 bool
 136 tnl_port_reconfigure(const struct ofport *ofport, uint32_t odp_port,
 137                      struct tnl_port **tnl_portp)
 138 {
 139     struct tnl_port *tnl_port = *tnl_portp;
 140
 141     if (tnl_port == &void_tnl_port) {
 142         *tnl_portp = tnl_port_add__(ofport, odp_port, false);
 143         return *tnl_portp != &void_tnl_port;
 144     } else if (tnl_port->ofport != ofport
 145                || tnl_port->match.odp_port != odp_port
 146                || tnl_port->netdev_seq != netdev_change_seq(ofport->netdev)) {
 147         VLOG_DBG("reconfiguring %s", tnl_port_get_name(tnl_port));
 148         tnl_port_del(tnl_port);
 149         *tnl_portp = tnl_port_add(ofport, odp_port);
 150         return true;
 151     }
 152     return false;
 153 }
 154
 155 /* Removes 'tnl_port' from the module. */
 156 void
 157 tnl_port_del(struct tnl_port *tnl_port)
 158 {
 159     if (tnl_port && tnl_port != &void_tnl_port) {
 160         tnl_port_mod_log(tnl_port, "removing");
 161         hmap_remove(&tnl_match_map, &tnl_port->match_node);
 162         free(tnl_port);
 163     }
 164 }
 165
 166 /* Transforms 'flow' so that it appears to have been received by a tunnel
 167  * OpenFlow port controlled by this module instead of the datapath port it
 168  * actually came in on.  Sets 'flow''s in_port to the appropriate OpenFlow port
 169  * number.  Returns the 'ofport' corresponding to the new in_port.
 170  *
 171  * Callers should verify that 'flow' needs to be received by calling
 172  * tnl_port_should_receive() before this function.
 173  *
 174  * Leaves 'flow' untouched and returns null if unsuccessful. */
 175 const struct ofport *
 176 tnl_port_receive(struct flow *flow)
 177 {
 178     char *pre_flow_str = NULL;
 179     struct tnl_port *tnl_port;
 180     struct tnl_match match;
 181
 182     memset(&match, 0, sizeof match);
 183     match.odp_port = flow->in_port;
 184     match.ip_src = flow->tunnel.ip_dst;
 185     match.ip_dst = flow->tunnel.ip_src;
 186     match.in_key = flow->tunnel.tun_id;
 187     match.skb_mark = flow->skb_mark;
 188
 189     tnl_port = tnl_find(&match);
 190     if (!tnl_port) {
 191         struct ds ds = DS_EMPTY_INITIALIZER;
 192
 193         tnl_match_fmt(&match, &ds);
 194         VLOG_WARN_RL(&rl, "receive tunnel port not found (%s)", ds_cstr(&ds));
 195         ds_destroy(&ds);
 196         return NULL;
 197     }
 198
 199     if (!VLOG_DROP_DBG(&dbg_rl)) {
 200         pre_flow_str = flow_to_string(flow);
 201     }
 202
 203     flow->in_port = tnl_port->ofport->ofp_port;
 204     memset(&flow->tunnel, 0, sizeof flow->tunnel);
 205     flow->tunnel.tun_id = match.in_key;
 206
 207     if (pre_flow_str) {
 208         char *post_flow_str = flow_to_string(flow);
 209         char *tnl_str = tnl_port_fmt(tnl_port);
 210         VLOG_DBG("flow received\n"
 211                  "%s"
 212                  " pre: %s\n"
 213                  "post: %s",
 214                  tnl_str, pre_flow_str, post_flow_str);
 215         free(tnl_str);
 216         free(pre_flow_str);
 217         free(post_flow_str);
 218     }
 219     return tnl_port->ofport;
 220 }
 221
 222 /* Given that 'flow' should be output to the ofport corresponding to
 223  * 'tnl_port', updates 'flow''s tunnel headers and returns the actual datapath
 224  * port that the output should happen on.  May return OVSP_NONE if the output
 225  * shouldn't occur. */
 226 uint32_t
 227 tnl_port_send(const struct tnl_port *tnl_port, struct flow *flow)
 228 {
 229     const struct netdev_tunnel_config *cfg;
 230     char *pre_flow_str = NULL;
 231
 232     if (tnl_port == &void_tnl_port) {
 233         return OVSP_NONE;
 234     }
 235
 236     cfg = netdev_get_tunnel_config(tnl_port->ofport->netdev);
 237     ovs_assert(cfg);
 238
 239     if (!VLOG_DROP_DBG(&dbg_rl)) {
 240         pre_flow_str = flow_to_string(flow);
 241     }
 242
 243     flow->tunnel.ip_src = tnl_port->match.ip_src;
 244     flow->tunnel.ip_dst = tnl_port->match.ip_dst;
 245     flow->skb_mark = tnl_port->match.skb_mark;
 246
 247     if (!cfg->out_key_flow) {
 248         flow->tunnel.tun_id = cfg->out_key;
 249     }
 250
 251     if (cfg->ttl_inherit && is_ip_any(flow)) {
 252         flow->tunnel.ip_ttl = flow->nw_ttl;
 253     } else {
 254         flow->tunnel.ip_ttl = cfg->ttl;
 255     }
 256
 257     if (cfg->tos_inherit && is_ip_any(flow)) {
 258         flow->tunnel.ip_tos = flow->nw_tos & IP_DSCP_MASK;
 259     } else {
 260         flow->tunnel.ip_tos = cfg->tos;
 261     }
 262
 263     if ((flow->nw_tos & IP_ECN_MASK) == IP_ECN_CE) {
 264         flow->tunnel.ip_tos |= IP_ECN_ECT_0;
 265     } else {
 266         flow->tunnel.ip_tos |= flow->nw_tos & IP_ECN_MASK;
 267     }
 268
 269     flow->tunnel.flags = (cfg->dont_fragment ? FLOW_TNL_F_DONT_FRAGMENT : 0)
 270         | (cfg->csum ? FLOW_TNL_F_CSUM : 0)
 271         | (cfg->out_key_present ? FLOW_TNL_F_KEY : 0);
 272
 273     if (pre_flow_str) {
 274         char *post_flow_str = flow_to_string(flow);
 275         char *tnl_str = tnl_port_fmt(tnl_port);
 276         VLOG_DBG("flow sent\n"
 277                  "%s"
 278                  " pre: %s\n"
 279                  "post: %s",
 280                  tnl_str, pre_flow_str, post_flow_str);
 281         free(tnl_str);
 282         free(pre_flow_str);
 283         free(post_flow_str);
 284     }
 285
 286     return tnl_port->match.odp_port;
 287 }
 288
 289 static uint32_t
 290 tnl_hash(struct tnl_match *match)
 291 {
 292     BUILD_ASSERT_DECL(sizeof *match % sizeof(uint32_t) == 0);
 293     return hash_words((uint32_t *) match, sizeof *match / sizeof(uint32_t), 0);
 294 }
 295
 296 static struct tnl_port *
 297 tnl_find_exact(struct tnl_match *match)
 298 {
 299     struct tnl_port *tnl_port;
 300
 301     HMAP_FOR_EACH_WITH_HASH (tnl_port, match_node, tnl_hash(match),
 302                              &tnl_match_map) {
 303         if (!memcmp(match, &tnl_port->match, sizeof *match)) {
 304             return tnl_port;
 305         }
 306     }
 307     return NULL;
 308 }
 309
 310 static struct tnl_port *
 311 tnl_find(struct tnl_match *match_)
 312 {
 313     struct tnl_match match = *match_;
 314     struct tnl_port *tnl_port;
 315
 316     /* remote_ip, local_ip, in_key */
 317     tnl_port = tnl_find_exact(&match);
 318     if (tnl_port) {
 319         return tnl_port;
 320     }
 321
 322     /* remote_ip, in_key */
 323     match.ip_src = 0;
 324     tnl_port = tnl_find_exact(&match);
 325     if (tnl_port) {
 326         return tnl_port;
 327     }
 328     match.ip_src = match_->ip_src;
 329
 330     /* remote_ip, local_ip */
 331     match.in_key = 0;
 332     match.in_key_flow = true;
 333     tnl_port = tnl_find_exact(&match);
 334     if (tnl_port) {
 335         return tnl_port;
 336     }
 337
 338     /* remote_ip */
 339     match.ip_src = 0;
 340     tnl_port = tnl_find_exact(&match);
 341     if (tnl_port) {
 342         return tnl_port;
 343     }
 344
 345     return NULL;
 346 }
 347
 348 static void
 349 tnl_match_fmt(const struct tnl_match *match, struct ds *ds)
 350 {
 351     ds_put_format(ds, IP_FMT"->"IP_FMT, IP_ARGS(match->ip_src),
 352                   IP_ARGS(match->ip_dst));
 353
 354     if (match->in_key_flow) {
 355         ds_put_cstr(ds, ", key=flow");
 356     } else {
 357         ds_put_format(ds, ", key=%#"PRIx64, ntohll(match->in_key));
 358     }
 359
 360     ds_put_format(ds, ", dp port=%"PRIu32, match->odp_port);
 361     ds_put_format(ds, ", skb mark=%"PRIu32, match->skb_mark);
 362 }
 363
 364 static void
 365 tnl_port_mod_log(const struct tnl_port *tnl_port, const char *action)
 366 {
 367     if (VLOG_IS_DBG_ENABLED()) {
 368         struct ds ds = DS_EMPTY_INITIALIZER;
 369
 370         tnl_match_fmt(&tnl_port->match, &ds);
 371         VLOG_INFO("%s tunnel port %s (%s)", action,
 372                   tnl_port_get_name(tnl_port), ds_cstr(&ds));
 373         ds_destroy(&ds);
 374     }
 375 }
 376
 377 static char *
 378 tnl_port_fmt(const struct tnl_port *tnl_port)
 379 {
 380     const struct netdev_tunnel_config *cfg =
 381         netdev_get_tunnel_config(tnl_port->ofport->netdev);
 382     struct ds ds = DS_EMPTY_INITIALIZER;
 383
 384     ds_put_format(&ds, "port %"PRIu32": %s (%s: ", tnl_port->match.odp_port,
 385                   tnl_port_get_name(tnl_port),
 386                   netdev_get_type(tnl_port->ofport->netdev));
 387     tnl_match_fmt(&tnl_port->match, &ds);
 388
 389     if (cfg->out_key != cfg->in_key ||
 390         cfg->out_key_present != cfg->in_key_present ||
 391         cfg->out_key_flow != cfg->in_key_flow) {
 392         ds_put_cstr(&ds, ", out_key=");
 393         if (!cfg->out_key_present) {
 394             ds_put_cstr(&ds, "none");
 395         } else if (cfg->out_key_flow) {
 396             ds_put_cstr(&ds, "flow");
 397         } else {
 398             ds_put_format(&ds, "%#"PRIx64, ntohll(cfg->out_key));
 399         }
 400     }
 401
 402     if (cfg->ttl_inherit) {
 403         ds_put_cstr(&ds, ", ttl=inherit");
 404     } else {
 405         ds_put_format(&ds, ", ttl=%"PRIu8, cfg->ttl);
 406     }
 407
 408     if (cfg->tos_inherit) {
 409         ds_put_cstr(&ds, ", tos=inherit");
 410     } else if (cfg->tos) {
 411         ds_put_format(&ds, ", tos=%#"PRIx8, cfg->tos);
 412     }
 413
 414     if (!cfg->dont_fragment) {
 415         ds_put_cstr(&ds, ", df=false");
 416     }
 417
 418     if (cfg->csum) {
 419         ds_put_cstr(&ds, ", csum=true");
 420     }
 421
 422     ds_put_cstr(&ds, ")\n");
 423
 424     return ds_steal_cstr(&ds);
 425 }
 426
 427 static const char *
 428 tnl_port_get_name(const struct tnl_port *tnl_port)
 429 {
 430     return netdev_get_name(tnl_port->ofport->netdev);
 431 }