lib/dpif-linux.c

   1 /*
   2  * Copyright (c) 2008, 2009, 2010, 2011 Nicira Networks.
   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 "dpif-linux.h"
  20
  21 #include <assert.h>
  22 #include <ctype.h>
  23 #include <errno.h>
  24 #include <fcntl.h>
  25 #include <inttypes.h>
  26 #include <net/if.h>
  27 #include <linux/types.h>
  28 #include <linux/ethtool.h>
  29 #include <linux/pkt_sched.h>
  30 #include <linux/rtnetlink.h>
  31 #include <linux/sockios.h>
  32 #include <stdlib.h>
  33 #include <sys/ioctl.h>
  34 #include <sys/stat.h>
  35 #include <unistd.h>
  36
  37 #include "dpif-provider.h"
  38 #include "netdev.h"
  39 #include "netdev-vport.h"
  40 #include "netlink.h"
  41 #include "ofpbuf.h"
  42 #include "openvswitch/tunnel.h"
  43 #include "packets.h"
  44 #include "poll-loop.h"
  45 #include "rtnetlink.h"
  46 #include "rtnetlink-link.h"
  47 #include "shash.h"
  48 #include "svec.h"
  49 #include "util.h"
  50 #include "vlog.h"
  51
  52 VLOG_DEFINE_THIS_MODULE(dpif_linux);
  53
  54 /* Datapath interface for the openvswitch Linux kernel module. */
  55 struct dpif_linux {
  56     struct dpif dpif;
  57     int fd;
  58
  59     /* Used by dpif_linux_get_all_names(). */
  60     char *local_ifname;
  61     int minor;
  62
  63     /* Change notification. */
  64     int local_ifindex;          /* Ifindex of local port. */
  65     struct shash changed_ports;  /* Ports that have changed. */
  66     struct rtnetlink_notifier port_notifier;
  67     bool change_error;
  68 };
  69
  70 static struct vlog_rate_limit error_rl = VLOG_RATE_LIMIT_INIT(9999, 5);
  71
  72 static int do_ioctl(const struct dpif *, int cmd, const void *arg);
  73 static int lookup_internal_device(const char *name, int *dp_idx, int *port_no);
  74 static int lookup_minor(const char *name, int *minor);
  75 static int finish_open(struct dpif *, const char *local_ifname);
  76 static int get_openvswitch_major(void);
  77 static int create_minor(const char *name, int minor, struct dpif **dpifp);
  78 static int open_minor(int minor, struct dpif **dpifp);
  79 static int make_openvswitch_device(int minor, char **fnp);
  80 static void dpif_linux_port_changed(const struct rtnetlink_link_change *,
  81                                     void *dpif);
  82
  83 static struct dpif_linux *
  84 dpif_linux_cast(const struct dpif *dpif)
  85 {
  86     dpif_assert_class(dpif, &dpif_linux_class);
  87     return CONTAINER_OF(dpif, struct dpif_linux, dpif);
  88 }
  89
  90 static int
  91 dpif_linux_enumerate(struct svec *all_dps)
  92 {
  93     int major;
  94     int error;
  95     int i;
  96
  97     /* Check that the Open vSwitch module is loaded. */
  98     major = get_openvswitch_major();
  99     if (major < 0) {
 100         return -major;
 101     }
 102
 103     error = 0;
 104     for (i = 0; i < ODP_MAX; i++) {
 105         struct dpif *dpif;
 106         char devname[16];
 107         int retval;
 108
 109         sprintf(devname, "dp%d", i);
 110         retval = dpif_open(devname, "system", &dpif);
 111         if (!retval) {
 112             svec_add(all_dps, devname);
 113             dpif_uninit(dpif, true);
 114         } else if (retval != ENODEV && !error) {
 115             error = retval;
 116         }
 117     }
 118     return error;
 119 }
 120
 121 static int
 122 dpif_linux_open(const struct dpif_class *class OVS_UNUSED, const char *name,
 123                 bool create, struct dpif **dpifp)
 124 {
 125     int minor;
 126
 127     minor = !strncmp(name, "dp", 2)
 128             && isdigit((unsigned char)name[2]) ? atoi(name + 2) : -1;
 129     if (create) {
 130         if (minor >= 0) {
 131             return create_minor(name, minor, dpifp);
 132         } else {
 133             /* Scan for unused minor number. */
 134             for (minor = 0; minor < ODP_MAX; minor++) {
 135                 int error = create_minor(name, minor, dpifp);
 136                 if (error != EBUSY) {
 137                     return error;
 138                 }
 139             }
 140
 141             /* All datapath numbers in use. */
 142             return ENOBUFS;
 143         }
 144     } else {
 145         struct dpif_linux *dpif;
 146         struct odp_port port;
 147         int error;
 148
 149         if (minor < 0) {
 150             error = lookup_minor(name, &minor);
 151             if (error) {
 152                 return error;
 153             }
 154         }
 155
 156         error = open_minor(minor, dpifp);
 157         if (error) {
 158             return error;
 159         }
 160         dpif = dpif_linux_cast(*dpifp);
 161
 162         /* We need the local port's ifindex for the poll function.  Start by
 163          * getting the local port's name. */
 164         memset(&port, 0, sizeof port);
 165         port.port = ODPP_LOCAL;
 166         if (ioctl(dpif->fd, ODP_VPORT_QUERY, &port)) {
 167             error = errno;
 168             if (error != ENODEV) {
 169                 VLOG_WARN("%s: probe returned unexpected error: %s",
 170                           dpif_name(*dpifp), strerror(error));
 171             }
 172             dpif_uninit(*dpifp, true);
 173             return error;
 174         }
 175
 176         /* Then use that to finish up opening. */
 177         return finish_open(&dpif->dpif, port.devname);
 178     }
 179 }
 180
 181 static void
 182 dpif_linux_close(struct dpif *dpif_)
 183 {
 184     struct dpif_linux *dpif = dpif_linux_cast(dpif_);
 185     rtnetlink_link_notifier_unregister(&dpif->port_notifier);
 186     shash_destroy(&dpif->changed_ports);
 187     free(dpif->local_ifname);
 188     close(dpif->fd);
 189     free(dpif);
 190 }
 191
 192 static int
 193 dpif_linux_get_all_names(const struct dpif *dpif_, struct svec *all_names)
 194 {
 195     struct dpif_linux *dpif = dpif_linux_cast(dpif_);
 196
 197     svec_add_nocopy(all_names, xasprintf("dp%d", dpif->minor));
 198     svec_add(all_names, dpif->local_ifname);
 199     return 0;
 200 }
 201
 202 static int
 203 dpif_linux_destroy(struct dpif *dpif_)
 204 {
 205     return do_ioctl(dpif_, ODP_DP_DESTROY, NULL);
 206 }
 207
 208 static int
 209 dpif_linux_get_stats(const struct dpif *dpif_, struct odp_stats *stats)
 210 {
 211     memset(stats, 0, sizeof *stats);
 212     return do_ioctl(dpif_, ODP_DP_STATS, stats);
 213 }
 214
 215 static int
 216 dpif_linux_get_drop_frags(const struct dpif *dpif_, bool *drop_fragsp)
 217 {
 218     int drop_frags;
 219     int error;
 220
 221     error = do_ioctl(dpif_, ODP_GET_DROP_FRAGS, &drop_frags);
 222     if (!error) {
 223         *drop_fragsp = drop_frags & 1;
 224     }
 225     return error;
 226 }
 227
 228 static int
 229 dpif_linux_set_drop_frags(struct dpif *dpif_, bool drop_frags)
 230 {
 231     int drop_frags_int = drop_frags;
 232     return do_ioctl(dpif_, ODP_SET_DROP_FRAGS, &drop_frags_int);
 233 }
 234
 235 static const char *
 236 vport_type_to_netdev_type(const struct odp_port *odp_port)
 237 {
 238     struct tnl_port_config tnl_config;
 239
 240     switch (odp_port->type) {
 241     case ODP_VPORT_TYPE_UNSPEC:
 242         break;
 243
 244     case ODP_VPORT_TYPE_NETDEV:
 245         return "system";
 246
 247     case ODP_VPORT_TYPE_INTERNAL:
 248         return "internal";
 249
 250     case ODP_VPORT_TYPE_PATCH:
 251         return "patch";
 252
 253     case ODP_VPORT_TYPE_GRE:
 254         memcpy(&tnl_config, odp_port->config, sizeof tnl_config);
 255         return tnl_config.flags & TNL_F_IPSEC ? "ipsec_gre" : "gre";
 256
 257     case ODP_VPORT_TYPE_CAPWAP:
 258         return "capwap";
 259
 260     case __ODP_VPORT_TYPE_MAX:
 261         break;
 262     }
 263
 264     VLOG_WARN_RL(&error_rl, "dp%d: port `%s' has unsupported type %"PRIu32,
 265                  odp_port->dp_idx, odp_port->devname, odp_port->type);
 266     return "unknown";
 267 }
 268
 269 static enum odp_vport_type
 270 netdev_type_to_vport_type(const char *type)
 271 {
 272     return (!strcmp(type, "system") ? ODP_VPORT_TYPE_NETDEV
 273             : !strcmp(type, "internal") ? ODP_VPORT_TYPE_INTERNAL
 274             : !strcmp(type, "patch") ? ODP_VPORT_TYPE_PATCH
 275             : (!strcmp(type, "gre")
 276                || !strcmp(type, "ipsec_gre")) ? ODP_VPORT_TYPE_GRE
 277             : !strcmp(type, "capwap") ? ODP_VPORT_TYPE_CAPWAP
 278             : ODP_VPORT_TYPE_UNSPEC);
 279 }
 280
 281 static int
 282 dpif_linux_port_add(struct dpif *dpif, struct netdev *netdev,
 283                     uint16_t *port_nop)
 284 {
 285     const char *name = netdev_get_name(netdev);
 286     const char *type = netdev_get_type(netdev);
 287     struct odp_port port;
 288     int error;
 289
 290     memset(&port, 0, sizeof port);
 291     strncpy(port.devname, name, sizeof port.devname);
 292     netdev_vport_get_config(netdev, port.config);
 293
 294     port.type = netdev_type_to_vport_type(type);
 295     if (port.type == ODP_VPORT_TYPE_UNSPEC) {
 296         VLOG_WARN_RL(&error_rl, "%s: cannot create port `%s' because it has "
 297                      "unsupported type `%s'",
 298                      dpif_name(dpif), name, type);
 299         return EINVAL;
 300     }
 301
 302     error = do_ioctl(dpif, ODP_VPORT_ATTACH, &port);
 303     if (!error) {
 304         *port_nop = port.port;
 305     }
 306
 307     return error;
 308 }
 309
 310 static int
 311 dpif_linux_port_del(struct dpif *dpif_, uint16_t port_no_)
 312 {
 313     int port_no = port_no_;     /* Kernel expects an "int". */
 314     return do_ioctl(dpif_, ODP_VPORT_DETACH, &port_no);
 315 }
 316
 317 static int
 318 dpif_linux_port_query__(const struct dpif *dpif, uint32_t port_no,
 319                         const char *port_name, struct dpif_port *dpif_port)
 320 {
 321     struct odp_port odp_port;
 322     int error;
 323
 324     memset(&odp_port, 0, sizeof odp_port);
 325     odp_port.port = port_no;
 326     strncpy(odp_port.devname, port_name, sizeof odp_port.devname);
 327
 328     error = do_ioctl(dpif, ODP_VPORT_QUERY, &odp_port);
 329     if (error) {
 330         return error;
 331     } else if (odp_port.dp_idx != dpif_linux_cast(dpif)->minor) {
 332         /* A vport named 'port_name' exists but in some other datapath.  */
 333         return ENOENT;
 334     } else {
 335         dpif_port->name = xstrdup(odp_port.devname);
 336         dpif_port->type = xstrdup(vport_type_to_netdev_type(&odp_port));
 337         dpif_port->port_no = odp_port.port;
 338         return 0;
 339     }
 340 }
 341
 342 static int
 343 dpif_linux_port_query_by_number(const struct dpif *dpif, uint16_t port_no,
 344                                 struct dpif_port *dpif_port)
 345 {
 346     return dpif_linux_port_query__(dpif, port_no, "", dpif_port);
 347 }
 348
 349 static int
 350 dpif_linux_port_query_by_name(const struct dpif *dpif, const char *devname,
 351                               struct dpif_port *dpif_port)
 352 {
 353     return dpif_linux_port_query__(dpif, 0, devname, dpif_port);
 354 }
 355
 356 static int
 357 dpif_linux_flow_flush(struct dpif *dpif_)
 358 {
 359     return do_ioctl(dpif_, ODP_FLOW_FLUSH, NULL);
 360 }
 361
 362 static int
 363 dpif_linux_port_dump_start(const struct dpif *dpif OVS_UNUSED, void **statep)
 364 {
 365     *statep = xzalloc(sizeof(struct odp_port));
 366     return 0;
 367 }
 368
 369 static int
 370 dpif_linux_port_dump_next(const struct dpif *dpif, void *state,
 371                           struct dpif_port *dpif_port)
 372 {
 373     struct odp_port *odp_port = state;
 374     struct odp_vport_dump dump;
 375     int error;
 376
 377     dump.port = odp_port;
 378     dump.port_no = odp_port->port;
 379     error = do_ioctl(dpif, ODP_VPORT_DUMP, &dump);
 380     if (error) {
 381         return error;
 382     } else if (odp_port->devname[0] == '\0') {
 383         return EOF;
 384     } else {
 385         dpif_port->name = odp_port->devname;
 386         dpif_port->type = (char *) vport_type_to_netdev_type(odp_port);
 387         dpif_port->port_no = odp_port->port;
 388         odp_port->port++;
 389         return 0;
 390     }
 391 }
 392
 393 static int
 394 dpif_linux_port_dump_done(const struct dpif *dpif OVS_UNUSED, void *state)
 395 {
 396     free(state);
 397     return 0;
 398 }
 399
 400 static int
 401 dpif_linux_port_poll(const struct dpif *dpif_, char **devnamep)
 402 {
 403     struct dpif_linux *dpif = dpif_linux_cast(dpif_);
 404
 405     if (dpif->change_error) {
 406         dpif->change_error = false;
 407         shash_clear(&dpif->changed_ports);
 408         return ENOBUFS;
 409     } else if (!shash_is_empty(&dpif->changed_ports)) {
 410         struct shash_node *node = shash_first(&dpif->changed_ports);
 411         *devnamep = shash_steal(&dpif->changed_ports, node);
 412         return 0;
 413     } else {
 414         return EAGAIN;
 415     }
 416 }
 417
 418 static void
 419 dpif_linux_port_poll_wait(const struct dpif *dpif_)
 420 {
 421     struct dpif_linux *dpif = dpif_linux_cast(dpif_);
 422     if (!shash_is_empty(&dpif->changed_ports) || dpif->change_error) {
 423         poll_immediate_wake();
 424     } else {
 425         rtnetlink_link_notifier_wait();
 426     }
 427 }
 428
 429 static int
 430 dpif_linux_flow_get(const struct dpif *dpif_, struct odp_flow flows[], int n)
 431 {
 432     struct odp_flowvec fv;
 433     fv.flows = flows;
 434     fv.n_flows = n;
 435     return do_ioctl(dpif_, ODP_FLOW_GET, &fv);
 436 }
 437
 438 static int
 439 dpif_linux_flow_put(struct dpif *dpif_, struct odp_flow_put *put)
 440 {
 441     return do_ioctl(dpif_, ODP_FLOW_PUT, put);
 442 }
 443
 444 static int
 445 dpif_linux_flow_del(struct dpif *dpif_, struct odp_flow *flow)
 446 {
 447     return do_ioctl(dpif_, ODP_FLOW_DEL, flow);
 448 }
 449
 450 static int
 451 dpif_linux_flow_dump_start(const struct dpif *dpif OVS_UNUSED, void **statep)
 452 {
 453     *statep = xzalloc(sizeof(struct odp_flow_dump));
 454     return 0;
 455 }
 456
 457 static int
 458 dpif_linux_flow_dump_next(const struct dpif *dpif, void *state,
 459                           struct odp_flow *flow)
 460 {
 461     struct odp_flow_dump *dump = state;
 462     int error;
 463
 464     dump->flow = flow;
 465     error = do_ioctl(dpif, ODP_FLOW_DUMP, dump);
 466     return error ? error : flow->flags & ODPFF_EOF ? EOF : 0;
 467 }
 468
 469 static int
 470 dpif_linux_flow_dump_done(const struct dpif *dpif OVS_UNUSED, void *state)
 471 {
 472     free(state);
 473     return 0;
 474 }
 475
 476 static int
 477 dpif_linux_execute(struct dpif *dpif_,
 478                    const struct nlattr *actions, size_t actions_len,
 479                    const struct ofpbuf *buf)
 480 {
 481     struct odp_execute execute;
 482     memset(&execute, 0, sizeof execute);
 483     execute.actions = (struct nlattr *) actions;
 484     execute.actions_len = actions_len;
 485     execute.data = buf->data;
 486     execute.length = buf->size;
 487     return do_ioctl(dpif_, ODP_EXECUTE, &execute);
 488 }
 489
 490 static int
 491 dpif_linux_recv_get_mask(const struct dpif *dpif_, int *listen_mask)
 492 {
 493     return do_ioctl(dpif_, ODP_GET_LISTEN_MASK, listen_mask);
 494 }
 495
 496 static int
 497 dpif_linux_recv_set_mask(struct dpif *dpif_, int listen_mask)
 498 {
 499     return do_ioctl(dpif_, ODP_SET_LISTEN_MASK, &listen_mask);
 500 }
 501
 502 static int
 503 dpif_linux_get_sflow_probability(const struct dpif *dpif_,
 504                                  uint32_t *probability)
 505 {
 506     return do_ioctl(dpif_, ODP_GET_SFLOW_PROBABILITY, probability);
 507 }
 508
 509 static int
 510 dpif_linux_set_sflow_probability(struct dpif *dpif_, uint32_t probability)
 511 {
 512     return do_ioctl(dpif_, ODP_SET_SFLOW_PROBABILITY, &probability);
 513 }
 514
 515 static int
 516 dpif_linux_queue_to_priority(const struct dpif *dpif OVS_UNUSED,
 517                              uint32_t queue_id, uint32_t *priority)
 518 {
 519     if (queue_id < 0xf000) {
 520         *priority = TC_H_MAKE(1 << 16, queue_id + 1);
 521         return 0;
 522     } else {
 523         return EINVAL;
 524     }
 525 }
 526
 527 static int
 528 parse_odp_packet(struct ofpbuf *buf, struct dpif_upcall *upcall)
 529 {
 530     static const struct nl_policy odp_packet_policy[] = {
 531         /* Always present. */
 532         [ODP_PACKET_ATTR_TYPE] = { .type = NL_A_U32 },
 533         [ODP_PACKET_ATTR_PACKET] = { .type = NL_A_UNSPEC,
 534                                      .min_len = ETH_HEADER_LEN },
 535         [ODP_PACKET_ATTR_KEY] = { .type = NL_A_NESTED },
 536
 537         /* _ODPL_ACTION_NR only. */
 538         [ODP_PACKET_ATTR_USERDATA] = { .type = NL_A_U64, .optional = true },
 539
 540         /* _ODPL_SFLOW_NR only. */
 541         [ODP_PACKET_ATTR_SAMPLE_POOL] = { .type = NL_A_U32, .optional = true },
 542         [ODP_PACKET_ATTR_ACTIONS] = { .type = NL_A_NESTED, .optional = true },
 543     };
 544
 545     struct odp_packet *odp_packet = buf->data;
 546     struct nlattr *a[ARRAY_SIZE(odp_packet_policy)];
 547
 548     if (!nl_policy_parse(buf, sizeof *odp_packet, odp_packet_policy,
 549                          a, ARRAY_SIZE(odp_packet_policy))) {
 550         return EINVAL;
 551     }
 552
 553     memset(upcall, 0, sizeof *upcall);
 554     upcall->type = nl_attr_get_u32(a[ODP_PACKET_ATTR_TYPE]);
 555     upcall->packet = buf;
 556     upcall->packet->data = (void *) nl_attr_get(a[ODP_PACKET_ATTR_PACKET]);
 557     upcall->packet->size = nl_attr_get_size(a[ODP_PACKET_ATTR_PACKET]);
 558     upcall->key = (void *) nl_attr_get(a[ODP_PACKET_ATTR_KEY]);
 559     upcall->key_len = nl_attr_get_size(a[ODP_PACKET_ATTR_KEY]);
 560     upcall->userdata = (a[ODP_PACKET_ATTR_USERDATA]
 561                         ? nl_attr_get_u64(a[ODP_PACKET_ATTR_USERDATA])
 562                         : 0);
 563     upcall->sample_pool = (a[ODP_PACKET_ATTR_SAMPLE_POOL]
 564                         ? nl_attr_get_u32(a[ODP_PACKET_ATTR_SAMPLE_POOL])
 565                            : 0);
 566     if (a[ODP_PACKET_ATTR_ACTIONS]) {
 567         upcall->actions = (void *) nl_attr_get(a[ODP_PACKET_ATTR_ACTIONS]);
 568         upcall->actions_len = nl_attr_get_size(a[ODP_PACKET_ATTR_ACTIONS]);
 569     }
 570
 571     return 0;
 572 }
 573
 574 static int
 575 dpif_linux_recv(struct dpif *dpif_, struct dpif_upcall *upcall)
 576 {
 577     struct dpif_linux *dpif = dpif_linux_cast(dpif_);
 578     struct ofpbuf *buf;
 579     int retval;
 580     int error;
 581
 582     buf = ofpbuf_new(65536);
 583     retval = read(dpif->fd, ofpbuf_tail(buf), ofpbuf_tailroom(buf));
 584     if (retval < 0) {
 585         error = errno;
 586         if (error != EAGAIN) {
 587             VLOG_WARN_RL(&error_rl, "%s: read failed: %s",
 588                          dpif_name(dpif_), strerror(error));
 589         }
 590     } else if (retval >= sizeof(struct odp_packet)) {
 591         struct odp_packet *odp_packet = buf->data;
 592         buf->size += retval;
 593
 594         if (odp_packet->len <= retval) {
 595             error = parse_odp_packet(buf, upcall);
 596         } else {
 597             VLOG_WARN_RL(&error_rl, "%s: discarding message truncated "
 598                          "from %"PRIu32" bytes to %d",
 599                          dpif_name(dpif_), odp_packet->len, retval);
 600             error = ERANGE;
 601         }
 602     } else if (!retval) {
 603         VLOG_WARN_RL(&error_rl, "%s: unexpected end of file", dpif_name(dpif_));
 604         error = EPROTO;
 605     } else {
 606         VLOG_WARN_RL(&error_rl, "%s: discarding too-short message (%d bytes)",
 607                      dpif_name(dpif_), retval);
 608         error = ERANGE;
 609     }
 610
 611     if (error) {
 612         ofpbuf_delete(buf);
 613     }
 614     return error;
 615 }
 616
 617 static void
 618 dpif_linux_recv_wait(struct dpif *dpif_)
 619 {
 620     struct dpif_linux *dpif = dpif_linux_cast(dpif_);
 621     poll_fd_wait(dpif->fd, POLLIN);
 622 }
 623
 624 const struct dpif_class dpif_linux_class = {
 625     "system",
 626     NULL,
 627     NULL,
 628     dpif_linux_enumerate,
 629     dpif_linux_open,
 630     dpif_linux_close,
 631     dpif_linux_get_all_names,
 632     dpif_linux_destroy,
 633     dpif_linux_get_stats,
 634     dpif_linux_get_drop_frags,
 635     dpif_linux_set_drop_frags,
 636     dpif_linux_port_add,
 637     dpif_linux_port_del,
 638     dpif_linux_port_query_by_number,
 639     dpif_linux_port_query_by_name,
 640     dpif_linux_port_dump_start,
 641     dpif_linux_port_dump_next,
 642     dpif_linux_port_dump_done,
 643     dpif_linux_port_poll,
 644     dpif_linux_port_poll_wait,
 645     dpif_linux_flow_get,
 646     dpif_linux_flow_put,
 647     dpif_linux_flow_del,
 648     dpif_linux_flow_flush,
 649     dpif_linux_flow_dump_start,
 650     dpif_linux_flow_dump_next,
 651     dpif_linux_flow_dump_done,
 652     dpif_linux_execute,
 653     dpif_linux_recv_get_mask,
 654     dpif_linux_recv_set_mask,
 655     dpif_linux_get_sflow_probability,
 656     dpif_linux_set_sflow_probability,
 657     dpif_linux_queue_to_priority,
 658     dpif_linux_recv,
 659     dpif_linux_recv_wait,
 660 };
 661 \f
 662 static int get_openvswitch_major(void);
 663 static int get_major(const char *target);
 664
 665 static int
 666 do_ioctl(const struct dpif *dpif_, int cmd, const void *arg)
 667 {
 668     struct dpif_linux *dpif = dpif_linux_cast(dpif_);
 669     return ioctl(dpif->fd, cmd, arg) ? errno : 0;
 670 }
 671
 672 static int
 673 lookup_internal_device(const char *name, int *dp_idx, int *port_no)
 674 {
 675     struct odp_port odp_port;
 676     static int dp0_fd = -1;
 677
 678     if (dp0_fd < 0) {
 679         int error;
 680         char *fn;
 681
 682         error = make_openvswitch_device(0, &fn);
 683         if (error) {
 684             return error;
 685         }
 686
 687         dp0_fd = open(fn, O_RDONLY | O_NONBLOCK);
 688         if (dp0_fd < 0) {
 689             VLOG_WARN_RL(&error_rl, "%s: open failed (%s)",
 690                          fn, strerror(errno));
 691             free(fn);
 692             return errno;
 693         }
 694         free(fn);
 695     }
 696
 697     memset(&odp_port, 0, sizeof odp_port);
 698     strncpy(odp_port.devname, name, sizeof odp_port.devname);
 699     if (ioctl(dp0_fd, ODP_VPORT_QUERY, &odp_port)) {
 700         if (errno != ENODEV) {
 701             VLOG_WARN_RL(&error_rl, "%s: vport query failed (%s)",
 702                          name, strerror(errno));
 703         }
 704         return errno;
 705     } else if (odp_port.type == ODP_VPORT_TYPE_INTERNAL) {
 706         *dp_idx = odp_port.dp_idx;
 707         *port_no = odp_port.port;
 708         return 0;
 709     } else {
 710         return EINVAL;
 711     }
 712 }
 713
 714 static int
 715 lookup_minor(const char *name, int *minorp)
 716 {
 717     int minor, port_no;
 718     int error;
 719
 720     error = lookup_internal_device(name, &minor, &port_no);
 721     if (error) {
 722         return error;
 723     } else if (port_no != ODPP_LOCAL) {
 724         /* This is an Open vSwitch device but not the local port.  We
 725          * intentionally support only using the name of the local port as the
 726          * name of a datapath; otherwise, it would be too difficult to
 727          * enumerate all the names of a datapath. */
 728         return EOPNOTSUPP;
 729     } else {
 730         *minorp = minor;
 731         return 0;
 732     }
 733 }
 734
 735 bool
 736 dpif_linux_is_internal_device(const char *name)
 737 {
 738     int minor, port_no;
 739
 740     return !lookup_internal_device(name, &minor, &port_no);
 741 }
 742
 743 static int
 744 make_openvswitch_device(int minor, char **fnp)
 745 {
 746     const char dirname[] = "/dev/net";
 747     int major;
 748     dev_t dev;
 749     struct stat s;
 750     char fn[128];
 751
 752     *fnp = NULL;
 753
 754     major = get_openvswitch_major();
 755     if (major < 0) {
 756         return -major;
 757     }
 758     dev = makedev(major, minor);
 759
 760     sprintf(fn, "%s/dp%d", dirname, minor);
 761     if (!stat(fn, &s)) {
 762         if (!S_ISCHR(s.st_mode)) {
 763             VLOG_WARN_RL(&error_rl, "%s is not a character device, fixing",
 764                          fn);
 765         } else if (s.st_rdev != dev) {
 766             VLOG_WARN_RL(&error_rl,
 767                          "%s is device %u:%u but should be %u:%u, fixing",
 768                          fn, major(s.st_rdev), minor(s.st_rdev),
 769                          major(dev), minor(dev));
 770         } else {
 771             goto success;
 772         }
 773         if (unlink(fn)) {
 774             VLOG_WARN_RL(&error_rl, "%s: unlink failed (%s)",
 775                          fn, strerror(errno));
 776             return errno;
 777         }
 778     } else if (errno == ENOENT) {
 779         if (stat(dirname, &s)) {
 780             if (errno == ENOENT) {
 781                 if (mkdir(dirname, 0755)) {
 782                     VLOG_WARN_RL(&error_rl, "%s: mkdir failed (%s)",
 783                                  dirname, strerror(errno));
 784                     return errno;
 785                 }
 786             } else {
 787                 VLOG_WARN_RL(&error_rl, "%s: stat failed (%s)",
 788                              dirname, strerror(errno));
 789                 return errno;
 790             }
 791         }
 792     } else {
 793         VLOG_WARN_RL(&error_rl, "%s: stat failed (%s)", fn, strerror(errno));
 794         return errno;
 795     }
 796
 797     /* The device needs to be created. */
 798     if (mknod(fn, S_IFCHR | 0700, dev)) {
 799         VLOG_WARN_RL(&error_rl,
 800                      "%s: creating character device %u:%u failed (%s)",
 801                      fn, major(dev), minor(dev), strerror(errno));
 802         return errno;
 803     }
 804
 805 success:
 806     *fnp = xstrdup(fn);
 807     return 0;
 808 }
 809
 810 /* Return the major device number of the Open vSwitch device.  If it
 811  * cannot be determined, a negative errno is returned. */
 812 static int
 813 get_openvswitch_major(void)
 814 {
 815     static int openvswitch_major = -1;
 816     if (openvswitch_major < 0) {
 817         openvswitch_major = get_major("openvswitch");
 818     }
 819     return openvswitch_major;
 820 }
 821
 822 static int
 823 get_major(const char *target)
 824 {
 825     const char fn[] = "/proc/devices";
 826     char line[128];
 827     FILE *file;
 828     int ln;
 829
 830     file = fopen(fn, "r");
 831     if (!file) {
 832         VLOG_ERR("opening %s failed (%s)", fn, strerror(errno));
 833         return -errno;
 834     }
 835
 836     for (ln = 1; fgets(line, sizeof line, file); ln++) {
 837         char name[64];
 838         int major;
 839
 840         if (!strncmp(line, "Character", 9) || line[0] == '\0') {
 841             /* Nothing to do. */
 842         } else if (!strncmp(line, "Block", 5)) {
 843             /* We only want character devices, so skip the rest of the file. */
 844             break;
 845         } else if (sscanf(line, "%d %63s", &major, name)) {
 846             if (!strcmp(name, target)) {
 847                 fclose(file);
 848                 return major;
 849             }
 850         } else {
 851             VLOG_WARN_ONCE("%s:%d: syntax error", fn, ln);
 852         }
 853     }
 854
 855     fclose(file);
 856
 857     VLOG_ERR("%s: %s major not found (is the module loaded?)", fn, target);
 858     return -ENODEV;
 859 }
 860
 861 static int
 862 finish_open(struct dpif *dpif_, const char *local_ifname)
 863 {
 864     struct dpif_linux *dpif = dpif_linux_cast(dpif_);
 865     dpif->local_ifname = xstrdup(local_ifname);
 866     dpif->local_ifindex = if_nametoindex(local_ifname);
 867     if (!dpif->local_ifindex) {
 868         int error = errno;
 869         dpif_uninit(dpif_, true);
 870         VLOG_WARN("could not get ifindex of %s device: %s",
 871                   local_ifname, strerror(errno));
 872         return error;
 873     }
 874     return 0;
 875 }
 876
 877 static int
 878 create_minor(const char *name, int minor, struct dpif **dpifp)
 879 {
 880     int error = open_minor(minor, dpifp);
 881     if (!error) {
 882         error = do_ioctl(*dpifp, ODP_DP_CREATE, name);
 883         if (!error) {
 884             error = finish_open(*dpifp, name);
 885         } else {
 886             dpif_uninit(*dpifp, true);
 887         }
 888     }
 889     return error;
 890 }
 891
 892 static int
 893 open_minor(int minor, struct dpif **dpifp)
 894 {
 895     int error;
 896     char *fn;
 897     int fd;
 898
 899     error = make_openvswitch_device(minor, &fn);
 900     if (error) {
 901         return error;
 902     }
 903
 904     fd = open(fn, O_RDONLY | O_NONBLOCK);
 905     if (fd >= 0) {
 906         struct dpif_linux *dpif = xmalloc(sizeof *dpif);
 907         error = rtnetlink_link_notifier_register(&dpif->port_notifier,
 908                                                  dpif_linux_port_changed,
 909                                                  dpif);
 910         if (!error) {
 911             char *name;
 912
 913             name = xasprintf("dp%d", minor);
 914             dpif_init(&dpif->dpif, &dpif_linux_class, name, minor, minor);
 915             free(name);
 916
 917             dpif->fd = fd;
 918             dpif->local_ifname = NULL;
 919             dpif->minor = minor;
 920             dpif->local_ifindex = 0;
 921             shash_init(&dpif->changed_ports);
 922             dpif->change_error = false;
 923             *dpifp = &dpif->dpif;
 924         } else {
 925             free(dpif);
 926         }
 927     } else {
 928         error = errno;
 929         VLOG_WARN("%s: open failed (%s)", fn, strerror(error));
 930     }
 931     free(fn);
 932
 933     return error;
 934 }
 935
 936 static void
 937 dpif_linux_port_changed(const struct rtnetlink_link_change *change,
 938                         void *dpif_)
 939 {
 940     struct dpif_linux *dpif = dpif_;
 941
 942     if (change) {
 943         if (change->master_ifindex == dpif->local_ifindex
 944             && (change->nlmsg_type == RTM_NEWLINK
 945                 || change->nlmsg_type == RTM_DELLINK))
 946         {
 947             /* Our datapath changed, either adding a new port or deleting an
 948              * existing one. */
 949             shash_add_once(&dpif->changed_ports, change->ifname, NULL);
 950         }
 951     } else {
 952         dpif->change_error = true;
 953     }
 954 }