lib/dpif-linux.c

   1 /*
   2  * Copyright (c) 2008, 2009, 2010 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 #include "dpif.h"
  19
  20 #include <assert.h>
  21 #include <ctype.h>
  22 #include <errno.h>
  23 #include <fcntl.h>
  24 #include <inttypes.h>
  25 #include <net/if.h>
  26 #include <linux/types.h>
  27 #include <linux/ethtool.h>
  28 #include <linux/pkt_sched.h>
  29 #include <linux/rtnetlink.h>
  30 #include <linux/sockios.h>
  31 #include <stdlib.h>
  32 #include <sys/ioctl.h>
  33 #include <sys/stat.h>
  34 #include <unistd.h>
  35
  36 #include "dpif-provider.h"
  37 #include "netdev.h"
  38 #include "ofpbuf.h"
  39 #include "poll-loop.h"
  40 #include "rtnetlink.h"
  41 #include "shash.h"
  42 #include "svec.h"
  43 #include "util.h"
  44 #include "vlog.h"
  45
  46 VLOG_DEFINE_THIS_MODULE(dpif_linux);
  47
  48 /* Datapath interface for the openvswitch Linux kernel module. */
  49 struct dpif_linux {
  50     struct dpif dpif;
  51     int fd;
  52
  53     /* Used by dpif_linux_get_all_names(). */
  54     char *local_ifname;
  55     int minor;
  56
  57     /* Change notification. */
  58     int local_ifindex;          /* Ifindex of local port. */
  59     struct shash changed_ports;  /* Ports that have changed. */
  60     struct rtnetlink_notifier port_notifier;
  61     bool change_error;
  62 };
  63
  64 static struct vlog_rate_limit error_rl = VLOG_RATE_LIMIT_INIT(9999, 5);
  65
  66 static int do_ioctl(const struct dpif *, int cmd, const void *arg);
  67 static int lookup_minor(const char *name, int *minor);
  68 static int finish_open(struct dpif *, const char *local_ifname);
  69 static int get_openvswitch_major(void);
  70 static int create_minor(const char *name, int minor, struct dpif **dpifp);
  71 static int open_minor(int minor, struct dpif **dpifp);
  72 static int make_openvswitch_device(int minor, char **fnp);
  73 static void dpif_linux_port_changed(const struct rtnetlink_change *,
  74                                     void *dpif);
  75
  76 static struct dpif_linux *
  77 dpif_linux_cast(const struct dpif *dpif)
  78 {
  79     dpif_assert_class(dpif, &dpif_linux_class);
  80     return CONTAINER_OF(dpif, struct dpif_linux, dpif);
  81 }
  82
  83 static int
  84 dpif_linux_enumerate(struct svec *all_dps)
  85 {
  86     int major;
  87     int error;
  88     int i;
  89
  90     /* Check that the Open vSwitch module is loaded. */
  91     major = get_openvswitch_major();
  92     if (major < 0) {
  93         return -major;
  94     }
  95
  96     error = 0;
  97     for (i = 0; i < ODP_MAX; i++) {
  98         struct dpif *dpif;
  99         char devname[16];
 100         int retval;
 101
 102         sprintf(devname, "dp%d", i);
 103         retval = dpif_open(devname, "system", &dpif);
 104         if (!retval) {
 105             svec_add(all_dps, devname);
 106             dpif_uninit(dpif, true);
 107         } else if (retval != ENODEV && !error) {
 108             error = retval;
 109         }
 110     }
 111     return error;
 112 }
 113
 114 static int
 115 dpif_linux_open(const struct dpif_class *class OVS_UNUSED, const char *name,
 116                 bool create, struct dpif **dpifp)
 117 {
 118     int minor;
 119
 120     minor = !strncmp(name, "dp", 2)
 121             && isdigit((unsigned char)name[2]) ? atoi(name + 2) : -1;
 122     if (create) {
 123         if (minor >= 0) {
 124             return create_minor(name, minor, dpifp);
 125         } else {
 126             /* Scan for unused minor number. */
 127             for (minor = 0; minor < ODP_MAX; minor++) {
 128                 int error = create_minor(name, minor, dpifp);
 129                 if (error != EBUSY) {
 130                     return error;
 131                 }
 132             }
 133
 134             /* All datapath numbers in use. */
 135             return ENOBUFS;
 136         }
 137     } else {
 138         struct dpif_linux *dpif;
 139         struct odp_port port;
 140         int error;
 141
 142         if (minor < 0) {
 143             error = lookup_minor(name, &minor);
 144             if (error) {
 145                 return error;
 146             }
 147         }
 148
 149         error = open_minor(minor, dpifp);
 150         if (error) {
 151             return error;
 152         }
 153         dpif = dpif_linux_cast(*dpifp);
 154
 155         /* We need the local port's ifindex for the poll function.  Start by
 156          * getting the local port's name. */
 157         memset(&port, 0, sizeof port);
 158         port.port = ODPP_LOCAL;
 159         if (ioctl(dpif->fd, ODP_PORT_QUERY, &port)) {
 160             error = errno;
 161             if (error != ENODEV) {
 162                 VLOG_WARN("%s: probe returned unexpected error: %s",
 163                           dpif_name(*dpifp), strerror(error));
 164             }
 165             dpif_uninit(*dpifp, true);
 166             return error;
 167         }
 168
 169         /* Then use that to finish up opening. */
 170         return finish_open(&dpif->dpif, port.devname);
 171     }
 172 }
 173
 174 static void
 175 dpif_linux_close(struct dpif *dpif_)
 176 {
 177     struct dpif_linux *dpif = dpif_linux_cast(dpif_);
 178     rtnetlink_notifier_unregister(&dpif->port_notifier);
 179     shash_destroy(&dpif->changed_ports);
 180     free(dpif->local_ifname);
 181     close(dpif->fd);
 182     free(dpif);
 183 }
 184
 185 static int
 186 dpif_linux_get_all_names(const struct dpif *dpif_, struct svec *all_names)
 187 {
 188     struct dpif_linux *dpif = dpif_linux_cast(dpif_);
 189
 190     svec_add_nocopy(all_names, xasprintf("dp%d", dpif->minor));
 191     svec_add(all_names, dpif->local_ifname);
 192     return 0;
 193 }
 194
 195 static int
 196 dpif_linux_destroy(struct dpif *dpif_)
 197 {
 198     struct odp_port *ports;
 199     size_t n_ports;
 200     int err;
 201     int i;
 202
 203     err = dpif_port_list(dpif_, &ports, &n_ports);
 204     if (err) {
 205         return err;
 206     }
 207
 208     for (i = 0; i < n_ports; i++) {
 209         if (ports[i].port != ODPP_LOCAL) {
 210             err = do_ioctl(dpif_, ODP_VPORT_DEL, ports[i].devname);
 211             if (err) {
 212                 VLOG_WARN_RL(&error_rl, "%s: error deleting port %s (%s)",
 213                              dpif_name(dpif_), ports[i].devname, strerror(err));
 214             }
 215         }
 216     }
 217
 218     free(ports);
 219
 220     return do_ioctl(dpif_, ODP_DP_DESTROY, NULL);
 221 }
 222
 223 static int
 224 dpif_linux_get_stats(const struct dpif *dpif_, struct odp_stats *stats)
 225 {
 226     memset(stats, 0, sizeof *stats);
 227     return do_ioctl(dpif_, ODP_DP_STATS, stats);
 228 }
 229
 230 static int
 231 dpif_linux_get_drop_frags(const struct dpif *dpif_, bool *drop_fragsp)
 232 {
 233     int drop_frags;
 234     int error;
 235
 236     error = do_ioctl(dpif_, ODP_GET_DROP_FRAGS, &drop_frags);
 237     if (!error) {
 238         *drop_fragsp = drop_frags & 1;
 239     }
 240     return error;
 241 }
 242
 243 static int
 244 dpif_linux_set_drop_frags(struct dpif *dpif_, bool drop_frags)
 245 {
 246     int drop_frags_int = drop_frags;
 247     return do_ioctl(dpif_, ODP_SET_DROP_FRAGS, &drop_frags_int);
 248 }
 249
 250 static int
 251 dpif_linux_port_add(struct dpif *dpif_, const char *devname, uint16_t flags,
 252                     uint16_t *port_no)
 253 {
 254     struct odp_port port;
 255     int error;
 256
 257     memset(&port, 0, sizeof port);
 258     strncpy(port.devname, devname, sizeof port.devname);
 259     port.flags = flags;
 260     error = do_ioctl(dpif_, ODP_PORT_ATTACH, &port);
 261     if (!error) {
 262         *port_no = port.port;
 263     }
 264     return error;
 265 }
 266
 267 static int
 268 dpif_linux_port_del(struct dpif *dpif_, uint16_t port_no)
 269 {
 270     int tmp = port_no;
 271     int err;
 272     struct odp_port port;
 273
 274     err = dpif_port_query_by_number(dpif_, port_no, &port);
 275     if (err) {
 276         return err;
 277     }
 278
 279     err = do_ioctl(dpif_, ODP_PORT_DETACH, &tmp);
 280     if (err) {
 281         return err;
 282     }
 283
 284     if (!netdev_is_open(port.devname)) {
 285         /* Try deleting the port if no one has it open.  This shouldn't
 286          * actually be necessary unless the config changed while we weren't
 287          * running but it won't hurt anything if the port is already gone. */
 288         do_ioctl(dpif_, ODP_VPORT_DEL, port.devname);
 289     }
 290
 291     return 0;
 292 }
 293
 294 static int
 295 dpif_linux_port_query_by_number(const struct dpif *dpif_, uint16_t port_no,
 296                           struct odp_port *port)
 297 {
 298     memset(port, 0, sizeof *port);
 299     port->port = port_no;
 300     return do_ioctl(dpif_, ODP_PORT_QUERY, port);
 301 }
 302
 303 static int
 304 dpif_linux_port_query_by_name(const struct dpif *dpif_, const char *devname,
 305                               struct odp_port *port)
 306 {
 307     memset(port, 0, sizeof *port);
 308     strncpy(port->devname, devname, sizeof port->devname);
 309     return do_ioctl(dpif_, ODP_PORT_QUERY, port);
 310 }
 311
 312 static int
 313 dpif_linux_flow_flush(struct dpif *dpif_)
 314 {
 315     return do_ioctl(dpif_, ODP_FLOW_FLUSH, NULL);
 316 }
 317
 318 static int
 319 dpif_linux_port_list(const struct dpif *dpif_, struct odp_port *ports, int n)
 320 {
 321     struct odp_portvec pv;
 322     int error;
 323
 324     pv.ports = ports;
 325     pv.n_ports = n;
 326     error = do_ioctl(dpif_, ODP_PORT_LIST, &pv);
 327     return error ? -error : pv.n_ports;
 328 }
 329
 330 static int
 331 dpif_linux_port_poll(const struct dpif *dpif_, char **devnamep)
 332 {
 333     struct dpif_linux *dpif = dpif_linux_cast(dpif_);
 334
 335     if (dpif->change_error) {
 336         dpif->change_error = false;
 337         shash_clear(&dpif->changed_ports);
 338         return ENOBUFS;
 339     } else if (!shash_is_empty(&dpif->changed_ports)) {
 340         struct shash_node *node = shash_first(&dpif->changed_ports);
 341         *devnamep = shash_steal(&dpif->changed_ports, node);
 342         return 0;
 343     } else {
 344         return EAGAIN;
 345     }
 346 }
 347
 348 static void
 349 dpif_linux_port_poll_wait(const struct dpif *dpif_)
 350 {
 351     struct dpif_linux *dpif = dpif_linux_cast(dpif_);
 352     if (!shash_is_empty(&dpif->changed_ports) || dpif->change_error) {
 353         poll_immediate_wake();
 354     } else {
 355         rtnetlink_notifier_wait();
 356     }
 357 }
 358
 359 static int
 360 dpif_linux_flow_get(const struct dpif *dpif_, struct odp_flow flows[], int n)
 361 {
 362     struct odp_flowvec fv;
 363     fv.flows = flows;
 364     fv.n_flows = n;
 365     return do_ioctl(dpif_, ODP_FLOW_GET, &fv);
 366 }
 367
 368 static int
 369 dpif_linux_flow_put(struct dpif *dpif_, struct odp_flow_put *put)
 370 {
 371     return do_ioctl(dpif_, ODP_FLOW_PUT, put);
 372 }
 373
 374 static int
 375 dpif_linux_flow_del(struct dpif *dpif_, struct odp_flow *flow)
 376 {
 377     return do_ioctl(dpif_, ODP_FLOW_DEL, flow);
 378 }
 379
 380 static int
 381 dpif_linux_flow_list(const struct dpif *dpif_, struct odp_flow flows[], int n)
 382 {
 383     struct odp_flowvec fv;
 384     int error;
 385
 386     fv.flows = flows;
 387     fv.n_flows = n;
 388     error = do_ioctl(dpif_, ODP_FLOW_LIST, &fv);
 389     return error ? -error : fv.n_flows;
 390 }
 391
 392 static int
 393 dpif_linux_execute(struct dpif *dpif_,
 394                    const union odp_action actions[], int n_actions,
 395                    const struct ofpbuf *buf)
 396 {
 397     struct odp_execute execute;
 398     memset(&execute, 0, sizeof execute);
 399     execute.actions = (union odp_action *) actions;
 400     execute.n_actions = n_actions;
 401     execute.data = buf->data;
 402     execute.length = buf->size;
 403     return do_ioctl(dpif_, ODP_EXECUTE, &execute);
 404 }
 405
 406 static int
 407 dpif_linux_recv_get_mask(const struct dpif *dpif_, int *listen_mask)
 408 {
 409     return do_ioctl(dpif_, ODP_GET_LISTEN_MASK, listen_mask);
 410 }
 411
 412 static int
 413 dpif_linux_recv_set_mask(struct dpif *dpif_, int listen_mask)
 414 {
 415     return do_ioctl(dpif_, ODP_SET_LISTEN_MASK, &listen_mask);
 416 }
 417
 418 static int
 419 dpif_linux_get_sflow_probability(const struct dpif *dpif_,
 420                                  uint32_t *probability)
 421 {
 422     return do_ioctl(dpif_, ODP_GET_SFLOW_PROBABILITY, probability);
 423 }
 424
 425 static int
 426 dpif_linux_set_sflow_probability(struct dpif *dpif_, uint32_t probability)
 427 {
 428     return do_ioctl(dpif_, ODP_SET_SFLOW_PROBABILITY, &probability);
 429 }
 430
 431 static int
 432 dpif_linux_queue_to_priority(const struct dpif *dpif OVS_UNUSED,
 433                              uint32_t queue_id, uint32_t *priority)
 434 {
 435     if (queue_id < 0xf000) {
 436         *priority = TC_H_MAKE(1 << 16, queue_id + 1);
 437         return 0;
 438     } else {
 439         return EINVAL;
 440     }
 441 }
 442
 443 static int
 444 dpif_linux_recv(struct dpif *dpif_, struct ofpbuf **bufp)
 445 {
 446     struct dpif_linux *dpif = dpif_linux_cast(dpif_);
 447     struct ofpbuf *buf;
 448     int retval;
 449     int error;
 450
 451     buf = ofpbuf_new_with_headroom(65536, DPIF_RECV_MSG_PADDING);
 452     retval = read(dpif->fd, ofpbuf_tail(buf), ofpbuf_tailroom(buf));
 453     if (retval < 0) {
 454         error = errno;
 455         if (error != EAGAIN) {
 456             VLOG_WARN_RL(&error_rl, "%s: read failed: %s",
 457                          dpif_name(dpif_), strerror(error));
 458         }
 459     } else if (retval >= sizeof(struct odp_msg)) {
 460         struct odp_msg *msg = buf->data;
 461         if (msg->length <= retval) {
 462             buf->size += retval;
 463             *bufp = buf;
 464             return 0;
 465         } else {
 466             VLOG_WARN_RL(&error_rl, "%s: discarding message truncated "
 467                          "from %"PRIu32" bytes to %d",
 468                          dpif_name(dpif_), msg->length, retval);
 469             error = ERANGE;
 470         }
 471     } else if (!retval) {
 472         VLOG_WARN_RL(&error_rl, "%s: unexpected end of file", dpif_name(dpif_));
 473         error = EPROTO;
 474     } else {
 475         VLOG_WARN_RL(&error_rl,
 476                      "%s: discarding too-short message (%d bytes)",
 477                      dpif_name(dpif_), retval);
 478         error = ERANGE;
 479     }
 480
 481     *bufp = NULL;
 482     ofpbuf_delete(buf);
 483     return error;
 484 }
 485
 486 static void
 487 dpif_linux_recv_wait(struct dpif *dpif_)
 488 {
 489     struct dpif_linux *dpif = dpif_linux_cast(dpif_);
 490     poll_fd_wait(dpif->fd, POLLIN);
 491 }
 492
 493 const struct dpif_class dpif_linux_class = {
 494     "system",
 495     NULL,
 496     NULL,
 497     dpif_linux_enumerate,
 498     dpif_linux_open,
 499     dpif_linux_close,
 500     dpif_linux_get_all_names,
 501     dpif_linux_destroy,
 502     dpif_linux_get_stats,
 503     dpif_linux_get_drop_frags,
 504     dpif_linux_set_drop_frags,
 505     dpif_linux_port_add,
 506     dpif_linux_port_del,
 507     dpif_linux_port_query_by_number,
 508     dpif_linux_port_query_by_name,
 509     dpif_linux_port_list,
 510     dpif_linux_port_poll,
 511     dpif_linux_port_poll_wait,
 512     dpif_linux_flow_get,
 513     dpif_linux_flow_put,
 514     dpif_linux_flow_del,
 515     dpif_linux_flow_flush,
 516     dpif_linux_flow_list,
 517     dpif_linux_execute,
 518     dpif_linux_recv_get_mask,
 519     dpif_linux_recv_set_mask,
 520     dpif_linux_get_sflow_probability,
 521     dpif_linux_set_sflow_probability,
 522     dpif_linux_queue_to_priority,
 523     dpif_linux_recv,
 524     dpif_linux_recv_wait,
 525 };
 526 \f
 527 static int get_openvswitch_major(void);
 528 static int get_major(const char *target);
 529
 530 static int
 531 do_ioctl(const struct dpif *dpif_, int cmd, const void *arg)
 532 {
 533     struct dpif_linux *dpif = dpif_linux_cast(dpif_);
 534     return ioctl(dpif->fd, cmd, arg) ? errno : 0;
 535 }
 536
 537 static int
 538 lookup_minor(const char *name, int *minorp)
 539 {
 540     struct ethtool_drvinfo drvinfo;
 541     int minor, port_no;
 542     struct ifreq ifr;
 543     int error;
 544     int sock;
 545
 546     sock = socket(AF_INET, SOCK_DGRAM, 0);
 547     if (sock < 0) {
 548         VLOG_WARN("socket(AF_INET) failed: %s", strerror(errno));
 549         error = errno;
 550         goto error;
 551     }
 552
 553     memset(&ifr, 0, sizeof ifr);
 554     strncpy(ifr.ifr_name, name, sizeof ifr.ifr_name);
 555     ifr.ifr_data = (caddr_t) &drvinfo;
 556
 557     memset(&drvinfo, 0, sizeof drvinfo);
 558     drvinfo.cmd = ETHTOOL_GDRVINFO;
 559     if (ioctl(sock, SIOCETHTOOL, &ifr)) {
 560         VLOG_WARN("ioctl(SIOCETHTOOL) failed: %s", strerror(errno));
 561         error = errno;
 562         goto error_close_sock;
 563     }
 564
 565     if (strcmp(drvinfo.driver, "openvswitch")) {
 566         VLOG_WARN("%s is not an openvswitch device", name);
 567         error = EOPNOTSUPP;
 568         goto error_close_sock;
 569     }
 570
 571     if (sscanf(drvinfo.bus_info, "%d.%d", &minor, &port_no) != 2) {
 572         VLOG_WARN("%s ethtool bus_info has unexpected format", name);
 573         error = EPROTOTYPE;
 574         goto error_close_sock;
 575     } else if (port_no != ODPP_LOCAL) {
 576         /* This is an Open vSwitch device but not the local port.  We
 577          * intentionally support only using the name of the local port as the
 578          * name of a datapath; otherwise, it would be too difficult to
 579          * enumerate all the names of a datapath. */
 580         error = EOPNOTSUPP;
 581         goto error_close_sock;
 582     }
 583
 584     *minorp = minor;
 585     close(sock);
 586     return 0;
 587
 588 error_close_sock:
 589     close(sock);
 590 error:
 591     return error;
 592 }
 593
 594 static int
 595 make_openvswitch_device(int minor, char **fnp)
 596 {
 597     const char dirname[] = "/dev/net";
 598     int major;
 599     dev_t dev;
 600     struct stat s;
 601     char fn[128];
 602
 603     *fnp = NULL;
 604
 605     major = get_openvswitch_major();
 606     if (major < 0) {
 607         return -major;
 608     }
 609     dev = makedev(major, minor);
 610
 611     sprintf(fn, "%s/dp%d", dirname, minor);
 612     if (!stat(fn, &s)) {
 613         if (!S_ISCHR(s.st_mode)) {
 614             VLOG_WARN_RL(&error_rl, "%s is not a character device, fixing",
 615                          fn);
 616         } else if (s.st_rdev != dev) {
 617             VLOG_WARN_RL(&error_rl,
 618                          "%s is device %u:%u but should be %u:%u, fixing",
 619                          fn, major(s.st_rdev), minor(s.st_rdev),
 620                          major(dev), minor(dev));
 621         } else {
 622             goto success;
 623         }
 624         if (unlink(fn)) {
 625             VLOG_WARN_RL(&error_rl, "%s: unlink failed (%s)",
 626                          fn, strerror(errno));
 627             return errno;
 628         }
 629     } else if (errno == ENOENT) {
 630         if (stat(dirname, &s)) {
 631             if (errno == ENOENT) {
 632                 if (mkdir(dirname, 0755)) {
 633                     VLOG_WARN_RL(&error_rl, "%s: mkdir failed (%s)",
 634                                  dirname, strerror(errno));
 635                     return errno;
 636                 }
 637             } else {
 638                 VLOG_WARN_RL(&error_rl, "%s: stat failed (%s)",
 639                              dirname, strerror(errno));
 640                 return errno;
 641             }
 642         }
 643     } else {
 644         VLOG_WARN_RL(&error_rl, "%s: stat failed (%s)", fn, strerror(errno));
 645         return errno;
 646     }
 647
 648     /* The device needs to be created. */
 649     if (mknod(fn, S_IFCHR | 0700, dev)) {
 650         VLOG_WARN_RL(&error_rl,
 651                      "%s: creating character device %u:%u failed (%s)",
 652                      fn, major(dev), minor(dev), strerror(errno));
 653         return errno;
 654     }
 655
 656 success:
 657     *fnp = xstrdup(fn);
 658     return 0;
 659 }
 660
 661 /* Return the major device number of the Open vSwitch device.  If it
 662  * cannot be determined, a negative errno is returned. */
 663 static int
 664 get_openvswitch_major(void)
 665 {
 666     static int openvswitch_major = -1;
 667     if (openvswitch_major < 0) {
 668         openvswitch_major = get_major("openvswitch");
 669     }
 670     return openvswitch_major;
 671 }
 672
 673 static int
 674 get_major(const char *target)
 675 {
 676     const char fn[] = "/proc/devices";
 677     char line[128];
 678     FILE *file;
 679     int ln;
 680
 681     file = fopen(fn, "r");
 682     if (!file) {
 683         VLOG_ERR("opening %s failed (%s)", fn, strerror(errno));
 684         return -errno;
 685     }
 686
 687     for (ln = 1; fgets(line, sizeof line, file); ln++) {
 688         char name[64];
 689         int major;
 690
 691         if (!strncmp(line, "Character", 9) || line[0] == '\0') {
 692             /* Nothing to do. */
 693         } else if (!strncmp(line, "Block", 5)) {
 694             /* We only want character devices, so skip the rest of the file. */
 695             break;
 696         } else if (sscanf(line, "%d %63s", &major, name)) {
 697             if (!strcmp(name, target)) {
 698                 fclose(file);
 699                 return major;
 700             }
 701         } else {
 702             VLOG_WARN_ONCE("%s:%d: syntax error", fn, ln);
 703         }
 704     }
 705
 706     fclose(file);
 707
 708     VLOG_ERR("%s: %s major not found (is the module loaded?)", fn, target);
 709     return -ENODEV;
 710 }
 711
 712 static int
 713 finish_open(struct dpif *dpif_, const char *local_ifname)
 714 {
 715     struct dpif_linux *dpif = dpif_linux_cast(dpif_);
 716     dpif->local_ifname = xstrdup(local_ifname);
 717     dpif->local_ifindex = if_nametoindex(local_ifname);
 718     if (!dpif->local_ifindex) {
 719         int error = errno;
 720         dpif_uninit(dpif_, true);
 721         VLOG_WARN("could not get ifindex of %s device: %s",
 722                   local_ifname, strerror(errno));
 723         return error;
 724     }
 725     return 0;
 726 }
 727
 728 static int
 729 create_minor(const char *name, int minor, struct dpif **dpifp)
 730 {
 731     int error = open_minor(minor, dpifp);
 732     if (!error) {
 733         error = do_ioctl(*dpifp, ODP_DP_CREATE, name);
 734         if (!error) {
 735             error = finish_open(*dpifp, name);
 736         } else {
 737             dpif_uninit(*dpifp, true);
 738         }
 739     }
 740     return error;
 741 }
 742
 743 static int
 744 open_minor(int minor, struct dpif **dpifp)
 745 {
 746     int error;
 747     char *fn;
 748     int fd;
 749
 750     error = make_openvswitch_device(minor, &fn);
 751     if (error) {
 752         return error;
 753     }
 754
 755     fd = open(fn, O_RDONLY | O_NONBLOCK);
 756     if (fd >= 0) {
 757         struct dpif_linux *dpif = xmalloc(sizeof *dpif);
 758         error = rtnetlink_notifier_register(&dpif->port_notifier,
 759                                            dpif_linux_port_changed, dpif);
 760         if (!error) {
 761             char *name;
 762
 763             name = xasprintf("dp%d", minor);
 764             dpif_init(&dpif->dpif, &dpif_linux_class, name, minor, minor);
 765             free(name);
 766
 767             dpif->fd = fd;
 768             dpif->local_ifname = NULL;
 769             dpif->minor = minor;
 770             dpif->local_ifindex = 0;
 771             shash_init(&dpif->changed_ports);
 772             dpif->change_error = false;
 773             *dpifp = &dpif->dpif;
 774         } else {
 775             free(dpif);
 776         }
 777     } else {
 778         error = errno;
 779         VLOG_WARN("%s: open failed (%s)", fn, strerror(error));
 780     }
 781     free(fn);
 782
 783     return error;
 784 }
 785
 786 static void
 787 dpif_linux_port_changed(const struct rtnetlink_change *change, void *dpif_)
 788 {
 789     struct dpif_linux *dpif = dpif_;
 790
 791     if (change) {
 792         if (change->master_ifindex == dpif->local_ifindex
 793             && (change->nlmsg_type == RTM_NEWLINK
 794                 || change->nlmsg_type == RTM_DELLINK))
 795         {
 796             /* Our datapath changed, either adding a new port or deleting an
 797              * existing one. */
 798             shash_add_once(&dpif->changed_ports, change->ifname, NULL);
 799         }
 800     } else {
 801         dpif->change_error = true;
 802     }
 803 }