tests/vhost-user-bridge.c

   1 /*
   2  * Vhost User Bridge
   3  *
   4  * Copyright (c) 2015 Red Hat, Inc.
   5  *
   6  * Authors:
   7  *  Victor Kaplansky <victork@redhat.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2 or
  10  * later.  See the COPYING file in the top-level directory.
  11  */
  12
  13 /*
  14  * TODO:
  15  *     - main should get parameters from the command line.
  16  *     - implement all request handlers. Still not implemented:
  17  *          vubr_get_queue_num_exec()
  18  *          vubr_send_rarp_exec()
  19  *     - test for broken requests and virtqueue.
  20  *     - implement features defined by Virtio 1.0 spec.
  21  *     - support mergeable buffers and indirect descriptors.
  22  *     - implement clean shutdown.
  23  *     - implement non-blocking writes to UDP backend.
  24  *     - implement polling strategy.
  25  *     - implement clean starting/stopping of vq processing
  26  *     - implement clean starting/stopping of used and buffers
  27  *       dirty page logging.
  28  */
  29
  30 #define _FILE_OFFSET_BITS 64
  31
  32 #include "qemu/osdep.h"
  33 #include "qemu/atomic.h"
  34 #include "qemu/ctype.h"
  35 #include "qemu/iov.h"
  36 #include "standard-headers/linux/virtio_net.h"
  37 #include "libvhost-user.h"
  38
  39 #define VHOST_USER_BRIDGE_DEBUG 1
  40
  41 #define DPRINT(...) \
  42     do { \
  43         if (VHOST_USER_BRIDGE_DEBUG) { \
  44             printf(__VA_ARGS__); \
  45         } \
  46     } while (0)
  47
  48 enum {
  49     VHOST_USER_BRIDGE_MAX_QUEUES = 8,
  50 };
  51
  52 typedef void (*CallbackFunc)(int sock, void *ctx);
  53
  54 typedef struct Event {
  55     void *ctx;
  56     CallbackFunc callback;
  57 } Event;
  58
  59 typedef struct Dispatcher {
  60     int max_sock;
  61     fd_set fdset;
  62     Event events[FD_SETSIZE];
  63 } Dispatcher;
  64
  65 typedef struct VubrDev {
  66     VuDev vudev;
  67     Dispatcher dispatcher;
  68     int backend_udp_sock;
  69     struct sockaddr_in backend_udp_dest;
  70     int hdrlen;
  71     int sock;
  72     int ready;
  73     int quit;
  74     struct {
  75         int fd;
  76         void *addr;
  77         pthread_t thread;
  78     } notifier;
  79 } VubrDev;
  80
  81 static void
  82 vubr_die(const char *s)
  83 {
  84     perror(s);
  85     exit(1);
  86 }
  87
  88 static int
  89 dispatcher_init(Dispatcher *dispr)
  90 {
  91     FD_ZERO(&dispr->fdset);
  92     dispr->max_sock = -1;
  93     return 0;
  94 }
  95
  96 static int
  97 dispatcher_add(Dispatcher *dispr, int sock, void *ctx, CallbackFunc cb)
  98 {
  99     if (sock >= FD_SETSIZE) {
 100         fprintf(stderr,
 101                 "Error: Failed to add new event. sock %d should be less than %d\n",
 102                 sock, FD_SETSIZE);
 103         return -1;
 104     }
 105
 106     dispr->events[sock].ctx = ctx;
 107     dispr->events[sock].callback = cb;
 108
 109     FD_SET(sock, &dispr->fdset);
 110     if (sock > dispr->max_sock) {
 111         dispr->max_sock = sock;
 112     }
 113     DPRINT("Added sock %d for watching. max_sock: %d\n",
 114            sock, dispr->max_sock);
 115     return 0;
 116 }
 117
 118 static int
 119 dispatcher_remove(Dispatcher *dispr, int sock)
 120 {
 121     if (sock >= FD_SETSIZE) {
 122         fprintf(stderr,
 123                 "Error: Failed to remove event. sock %d should be less than %d\n",
 124                 sock, FD_SETSIZE);
 125         return -1;
 126     }
 127
 128     FD_CLR(sock, &dispr->fdset);
 129     DPRINT("Sock %d removed from dispatcher watch.\n", sock);
 130     return 0;
 131 }
 132
 133 /* timeout in us */
 134 static int
 135 dispatcher_wait(Dispatcher *dispr, uint32_t timeout)
 136 {
 137     struct timeval tv;
 138     tv.tv_sec = timeout / 1000000;
 139     tv.tv_usec = timeout % 1000000;
 140
 141     fd_set fdset = dispr->fdset;
 142
 143     /* wait until some of sockets become readable. */
 144     int rc = select(dispr->max_sock + 1, &fdset, 0, 0, &tv);
 145
 146     if (rc == -1) {
 147         vubr_die("select");
 148     }
 149
 150     /* Timeout */
 151     if (rc == 0) {
 152         return 0;
 153     }
 154
 155     /* Now call callback for every ready socket. */
 156
 157     int sock;
 158     for (sock = 0; sock < dispr->max_sock + 1; sock++) {
 159         /* The callback on a socket can remove other sockets from the
 160          * dispatcher, thus we have to check that the socket is
 161          * still not removed from dispatcher's list
 162          */
 163         if (FD_ISSET(sock, &fdset) && FD_ISSET(sock, &dispr->fdset)) {
 164             Event *e = &dispr->events[sock];
 165             e->callback(sock, e->ctx);
 166         }
 167     }
 168
 169     return 0;
 170 }
 171
 172 static void
 173 vubr_handle_tx(VuDev *dev, int qidx)
 174 {
 175     VuVirtq *vq = vu_get_queue(dev, qidx);
 176     VubrDev *vubr = container_of(dev, VubrDev, vudev);
 177     int hdrlen = vubr->hdrlen;
 178     VuVirtqElement *elem = NULL;
 179
 180     assert(qidx % 2);
 181
 182     for (;;) {
 183         ssize_t ret;
 184         unsigned int out_num;
 185         struct iovec sg[VIRTQUEUE_MAX_SIZE], *out_sg;
 186
 187         elem = vu_queue_pop(dev, vq, sizeof(VuVirtqElement));
 188         if (!elem) {
 189             break;
 190         }
 191
 192         out_num = elem->out_num;
 193         out_sg = elem->out_sg;
 194         if (out_num < 1) {
 195             fprintf(stderr, "virtio-net header not in first element\n");
 196             break;
 197         }
 198         if (VHOST_USER_BRIDGE_DEBUG) {
 199             iov_hexdump(out_sg, out_num, stderr, "TX:", 1024);
 200         }
 201
 202         if (hdrlen) {
 203             unsigned sg_num = iov_copy(sg, ARRAY_SIZE(sg),
 204                                        out_sg, out_num,
 205                                        hdrlen, -1);
 206             out_num = sg_num;
 207             out_sg = sg;
 208         }
 209
 210         struct msghdr msg = {
 211             .msg_name = (struct sockaddr *) &vubr->backend_udp_dest,
 212             .msg_namelen = sizeof(struct sockaddr_in),
 213             .msg_iov = out_sg,
 214             .msg_iovlen = out_num,
 215         };
 216         do {
 217             ret = sendmsg(vubr->backend_udp_sock, &msg, 0);
 218         } while (ret == -1 && (errno == EAGAIN || errno == EINTR));
 219
 220         if (ret == -1) {
 221             vubr_die("sendmsg()");
 222         }
 223
 224         vu_queue_push(dev, vq, elem, 0);
 225         vu_queue_notify(dev, vq);
 226
 227         free(elem);
 228         elem = NULL;
 229     }
 230
 231     free(elem);
 232 }
 233
 234
 235 /* this function reverse the effect of iov_discard_front() it must be
 236  * called with 'front' being the original struct iovec and 'bytes'
 237  * being the number of bytes you shaved off
 238  */
 239 static void
 240 iov_restore_front(struct iovec *front, struct iovec *iov, size_t bytes)
 241 {
 242     struct iovec *cur;
 243
 244     for (cur = front; cur != iov; cur++) {
 245         assert(bytes >= cur->iov_len);
 246         bytes -= cur->iov_len;
 247     }
 248
 249     cur->iov_base -= bytes;
 250     cur->iov_len += bytes;
 251 }
 252
 253 static void
 254 iov_truncate(struct iovec *iov, unsigned iovc, size_t bytes)
 255 {
 256     unsigned i;
 257
 258     for (i = 0; i < iovc; i++, iov++) {
 259         if (bytes < iov->iov_len) {
 260             iov->iov_len = bytes;
 261             return;
 262         }
 263
 264         bytes -= iov->iov_len;
 265     }
 266
 267     assert(!"couldn't truncate iov");
 268 }
 269
 270 static void
 271 vubr_backend_recv_cb(int sock, void *ctx)
 272 {
 273     VubrDev *vubr = (VubrDev *) ctx;
 274     VuDev *dev = &vubr->vudev;
 275     VuVirtq *vq = vu_get_queue(dev, 0);
 276     VuVirtqElement *elem = NULL;
 277     struct iovec mhdr_sg[VIRTQUEUE_MAX_SIZE];
 278     struct virtio_net_hdr_mrg_rxbuf mhdr;
 279     unsigned mhdr_cnt = 0;
 280     int hdrlen = vubr->hdrlen;
 281     int i = 0;
 282     struct virtio_net_hdr hdr = {
 283         .flags = 0,
 284         .gso_type = VIRTIO_NET_HDR_GSO_NONE
 285     };
 286
 287     DPRINT("\n\n   ***   IN UDP RECEIVE CALLBACK    ***\n\n");
 288     DPRINT("    hdrlen = %d\n", hdrlen);
 289
 290     if (!vu_queue_enabled(dev, vq) ||
 291         !vu_queue_started(dev, vq) ||
 292         !vu_queue_avail_bytes(dev, vq, hdrlen, 0)) {
 293         DPRINT("Got UDP packet, but no available descriptors on RX virtq.\n");
 294         return;
 295     }
 296
 297     while (1) {
 298         struct iovec *sg;
 299         ssize_t ret, total = 0;
 300         unsigned int num;
 301
 302         elem = vu_queue_pop(dev, vq, sizeof(VuVirtqElement));
 303         if (!elem) {
 304             break;
 305         }
 306
 307         if (elem->in_num < 1) {
 308             fprintf(stderr, "virtio-net contains no in buffers\n");
 309             break;
 310         }
 311
 312         sg = elem->in_sg;
 313         num = elem->in_num;
 314         if (i == 0) {
 315             if (hdrlen == 12) {
 316                 mhdr_cnt = iov_copy(mhdr_sg, ARRAY_SIZE(mhdr_sg),
 317                                     sg, elem->in_num,
 318                                     offsetof(typeof(mhdr), num_buffers),
 319                                     sizeof(mhdr.num_buffers));
 320             }
 321             iov_from_buf(sg, elem->in_num, 0, &hdr, sizeof hdr);
 322             total += hdrlen;
 323             ret = iov_discard_front(&sg, &num, hdrlen);
 324             assert(ret == hdrlen);
 325         }
 326
 327         struct msghdr msg = {
 328             .msg_name = (struct sockaddr *) &vubr->backend_udp_dest,
 329             .msg_namelen = sizeof(struct sockaddr_in),
 330             .msg_iov = sg,
 331             .msg_iovlen = num,
 332             .msg_flags = MSG_DONTWAIT,
 333         };
 334         ret = RETRY_ON_EINTR(recvmsg(vubr->backend_udp_sock, &msg, 0));
 335
 336         if (i == 0) {
 337             iov_restore_front(elem->in_sg, sg, hdrlen);
 338         }
 339
 340         if (ret == -1) {
 341             if (errno == EWOULDBLOCK) {
 342                 vu_queue_rewind(dev, vq, 1);
 343                 break;
 344             }
 345
 346             vubr_die("recvmsg()");
 347         }
 348
 349         total += ret;
 350         iov_truncate(elem->in_sg, elem->in_num, total);
 351         vu_queue_fill(dev, vq, elem, total, i++);
 352
 353         free(elem);
 354         elem = NULL;
 355
 356         break;        /* could loop if DONTWAIT worked? */
 357     }
 358
 359     if (mhdr_cnt) {
 360         mhdr.num_buffers = i;
 361         iov_from_buf(mhdr_sg, mhdr_cnt,
 362                      0,
 363                      &mhdr.num_buffers, sizeof mhdr.num_buffers);
 364     }
 365
 366     vu_queue_flush(dev, vq, i);
 367     vu_queue_notify(dev, vq);
 368
 369     free(elem);
 370 }
 371
 372 static void
 373 vubr_receive_cb(int sock, void *ctx)
 374 {
 375     VubrDev *vubr = (VubrDev *)ctx;
 376
 377     if (!vu_dispatch(&vubr->vudev)) {
 378         fprintf(stderr, "Error while dispatching\n");
 379     }
 380 }
 381
 382 typedef struct WatchData {
 383     VuDev *dev;
 384     vu_watch_cb cb;
 385     void *data;
 386 } WatchData;
 387
 388 static void
 389 watch_cb(int sock, void *ctx)
 390 {
 391     struct WatchData *wd = ctx;
 392
 393     wd->cb(wd->dev, VU_WATCH_IN, wd->data);
 394 }
 395
 396 static void
 397 vubr_set_watch(VuDev *dev, int fd, int condition,
 398                vu_watch_cb cb, void *data)
 399 {
 400     VubrDev *vubr = container_of(dev, VubrDev, vudev);
 401     static WatchData watches[FD_SETSIZE];
 402     struct WatchData *wd = &watches[fd];
 403
 404     wd->cb = cb;
 405     wd->data = data;
 406     wd->dev = dev;
 407     dispatcher_add(&vubr->dispatcher, fd, wd, watch_cb);
 408 }
 409
 410 static void
 411 vubr_remove_watch(VuDev *dev, int fd)
 412 {
 413     VubrDev *vubr = container_of(dev, VubrDev, vudev);
 414
 415     dispatcher_remove(&vubr->dispatcher, fd);
 416 }
 417
 418 static int
 419 vubr_send_rarp_exec(VuDev *dev, VhostUserMsg *vmsg)
 420 {
 421     DPRINT("Function %s() not implemented yet.\n", __func__);
 422     return 0;
 423 }
 424
 425 static int
 426 vubr_process_msg(VuDev *dev, VhostUserMsg *vmsg, int *do_reply)
 427 {
 428     switch (vmsg->request) {
 429     case VHOST_USER_SEND_RARP:
 430         *do_reply = vubr_send_rarp_exec(dev, vmsg);
 431         return 1;
 432     default:
 433         /* let the library handle the rest */
 434         return 0;
 435     }
 436
 437     return 0;
 438 }
 439
 440 static void
 441 vubr_set_features(VuDev *dev, uint64_t features)
 442 {
 443     VubrDev *vubr = container_of(dev, VubrDev, vudev);
 444
 445     if ((features & (1ULL << VIRTIO_F_VERSION_1)) ||
 446         (features & (1ULL << VIRTIO_NET_F_MRG_RXBUF))) {
 447         vubr->hdrlen = 12;
 448     } else {
 449         vubr->hdrlen = 10;
 450     }
 451 }
 452
 453 static uint64_t
 454 vubr_get_features(VuDev *dev)
 455 {
 456     return 1ULL << VIRTIO_NET_F_GUEST_ANNOUNCE |
 457         1ULL << VIRTIO_NET_F_MRG_RXBUF |
 458         1ULL << VIRTIO_F_VERSION_1;
 459 }
 460
 461 static void
 462 vubr_queue_set_started(VuDev *dev, int qidx, bool started)
 463 {
 464     VubrDev *vubr = container_of(dev, VubrDev, vudev);
 465     VuVirtq *vq = vu_get_queue(dev, qidx);
 466
 467     if (started && vubr->notifier.fd >= 0) {
 468         vu_set_queue_host_notifier(dev, vq, vubr->notifier.fd,
 469                                    qemu_real_host_page_size(),
 470                                    qidx * qemu_real_host_page_size());
 471     }
 472
 473     if (qidx % 2 == 1) {
 474         vu_set_queue_handler(dev, vq, started ? vubr_handle_tx : NULL);
 475     }
 476 }
 477
 478 static void
 479 vubr_panic(VuDev *dev, const char *msg)
 480 {
 481     VubrDev *vubr = container_of(dev, VubrDev, vudev);
 482
 483     fprintf(stderr, "PANIC: %s\n", msg);
 484
 485     dispatcher_remove(&vubr->dispatcher, dev->sock);
 486     vubr->quit = 1;
 487 }
 488
 489 static bool
 490 vubr_queue_is_processed_in_order(VuDev *dev, int qidx)
 491 {
 492     return true;
 493 }
 494
 495 static const VuDevIface vuiface = {
 496     .get_features = vubr_get_features,
 497     .set_features = vubr_set_features,
 498     .process_msg = vubr_process_msg,
 499     .queue_set_started = vubr_queue_set_started,
 500     .queue_is_processed_in_order = vubr_queue_is_processed_in_order,
 501 };
 502
 503 static void
 504 vubr_accept_cb(int sock, void *ctx)
 505 {
 506     VubrDev *dev = (VubrDev *)ctx;
 507     int conn_fd;
 508     struct sockaddr_un un;
 509     socklen_t len = sizeof(un);
 510
 511     conn_fd = accept(sock, (struct sockaddr *) &un, &len);
 512     if (conn_fd == -1) {
 513         vubr_die("accept()");
 514     }
 515     DPRINT("Got connection from remote peer on sock %d\n", conn_fd);
 516
 517     if (!vu_init(&dev->vudev,
 518                  VHOST_USER_BRIDGE_MAX_QUEUES,
 519                  conn_fd,
 520                  vubr_panic,
 521                  NULL,
 522                  vubr_set_watch,
 523                  vubr_remove_watch,
 524                  &vuiface)) {
 525         fprintf(stderr, "Failed to initialize libvhost-user\n");
 526         exit(1);
 527     }
 528
 529     dispatcher_add(&dev->dispatcher, conn_fd, ctx, vubr_receive_cb);
 530     dispatcher_remove(&dev->dispatcher, sock);
 531 }
 532
 533 static VubrDev *
 534 vubr_new(const char *path, bool client)
 535 {
 536     VubrDev *dev = (VubrDev *) calloc(1, sizeof(VubrDev));
 537     struct sockaddr_un un;
 538     CallbackFunc cb;
 539     size_t len;
 540
 541     if (strlen(path) >= sizeof(un.sun_path)) {
 542         fprintf(stderr, "unix domain socket path '%s' is too long\n", path);
 543         exit(1);
 544     }
 545
 546     /* Get a UNIX socket. */
 547     dev->sock = socket(AF_UNIX, SOCK_STREAM, 0);
 548     if (dev->sock == -1) {
 549         vubr_die("socket");
 550     }
 551
 552     dev->notifier.fd = -1;
 553
 554     un.sun_family = AF_UNIX;
 555     strcpy(un.sun_path, path);
 556     len = sizeof(un.sun_family) + strlen(path);
 557
 558     if (!client) {
 559         unlink(path);
 560
 561         if (bind(dev->sock, (struct sockaddr *) &un, len) == -1) {
 562             vubr_die("bind");
 563         }
 564
 565         if (listen(dev->sock, 1) == -1) {
 566             vubr_die("listen");
 567         }
 568         cb = vubr_accept_cb;
 569
 570         DPRINT("Waiting for connections on UNIX socket %s ...\n", path);
 571     } else {
 572         if (connect(dev->sock, (struct sockaddr *)&un, len) == -1) {
 573             vubr_die("connect");
 574         }
 575
 576         if (!vu_init(&dev->vudev,
 577                      VHOST_USER_BRIDGE_MAX_QUEUES,
 578                      dev->sock,
 579                      vubr_panic,
 580                      NULL,
 581                      vubr_set_watch,
 582                      vubr_remove_watch,
 583                      &vuiface)) {
 584             fprintf(stderr, "Failed to initialize libvhost-user\n");
 585             exit(1);
 586         }
 587
 588         cb = vubr_receive_cb;
 589     }
 590
 591     dispatcher_init(&dev->dispatcher);
 592
 593     dispatcher_add(&dev->dispatcher, dev->sock, (void *)dev, cb);
 594
 595     return dev;
 596 }
 597
 598 static void *notifier_thread(void *arg)
 599 {
 600     VuDev *dev = (VuDev *)arg;
 601     VubrDev *vubr = container_of(dev, VubrDev, vudev);
 602     int pagesize = qemu_real_host_page_size();
 603     int qidx;
 604
 605     while (true) {
 606         for (qidx = 0; qidx < VHOST_USER_BRIDGE_MAX_QUEUES; qidx++) {
 607             uint16_t *n = vubr->notifier.addr + pagesize * qidx;
 608
 609             if (*n == qidx) {
 610                 *n = 0xffff;
 611                 /* We won't miss notifications if we reset
 612                  * the memory first. */
 613                 smp_mb();
 614
 615                 DPRINT("Got a notification for queue%d via host notifier.\n",
 616                        qidx);
 617
 618                 if (qidx % 2 == 1) {
 619                     vubr_handle_tx(dev, qidx);
 620                 }
 621             }
 622             usleep(1000);
 623         }
 624     }
 625
 626     return NULL;
 627 }
 628
 629 static void
 630 vubr_host_notifier_setup(VubrDev *dev)
 631 {
 632     pthread_t thread;
 633     size_t length;
 634     void *addr;
 635     int fd;
 636
 637     length = qemu_real_host_page_size() * VHOST_USER_BRIDGE_MAX_QUEUES;
 638
 639     fd = g_file_open_tmp("vubr-XXXXXX", NULL, NULL);
 640     if (fd < 0) {
 641         vubr_die("mkstemp()");
 642     }
 643
 644     if (posix_fallocate(fd, 0, length) != 0) {
 645         vubr_die("posix_fallocate()");
 646     }
 647
 648     addr = mmap(NULL, length, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
 649     if (addr == MAP_FAILED) {
 650         vubr_die("mmap()");
 651     }
 652
 653     memset(addr, 0xff, length);
 654
 655     if (pthread_create(&thread, NULL, notifier_thread, &dev->vudev) != 0) {
 656         vubr_die("pthread_create()");
 657     }
 658
 659     dev->notifier.fd = fd;
 660     dev->notifier.addr = addr;
 661     dev->notifier.thread = thread;
 662 }
 663
 664 static void
 665 vubr_set_host(struct sockaddr_in *saddr, const char *host)
 666 {
 667     if (qemu_isdigit(host[0])) {
 668         if (!inet_aton(host, &saddr->sin_addr)) {
 669             fprintf(stderr, "inet_aton() failed.\n");
 670             exit(1);
 671         }
 672     } else {
 673         struct hostent *he = gethostbyname(host);
 674
 675         if (!he) {
 676             fprintf(stderr, "gethostbyname() failed.\n");
 677             exit(1);
 678         }
 679         saddr->sin_addr = *(struct in_addr *)he->h_addr;
 680     }
 681 }
 682
 683 static void
 684 vubr_backend_udp_setup(VubrDev *dev,
 685                        const char *local_host,
 686                        const char *local_port,
 687                        const char *remote_host,
 688                        const char *remote_port)
 689 {
 690     int sock;
 691     const char *r;
 692
 693     int lport, rport;
 694
 695     lport = strtol(local_port, (char **)&r, 0);
 696     if (r == local_port) {
 697         fprintf(stderr, "lport parsing failed.\n");
 698         exit(1);
 699     }
 700
 701     rport = strtol(remote_port, (char **)&r, 0);
 702     if (r == remote_port) {
 703         fprintf(stderr, "rport parsing failed.\n");
 704         exit(1);
 705     }
 706
 707     struct sockaddr_in si_local = {
 708         .sin_family = AF_INET,
 709         .sin_port = htons(lport),
 710     };
 711
 712     vubr_set_host(&si_local, local_host);
 713
 714     /* setup destination for sends */
 715     dev->backend_udp_dest = (struct sockaddr_in) {
 716         .sin_family = AF_INET,
 717         .sin_port = htons(rport),
 718     };
 719     vubr_set_host(&dev->backend_udp_dest, remote_host);
 720
 721     sock = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
 722     if (sock == -1) {
 723         vubr_die("socket");
 724     }
 725
 726     if (bind(sock, (struct sockaddr *)&si_local, sizeof(si_local)) == -1) {
 727         vubr_die("bind");
 728     }
 729
 730     dev->backend_udp_sock = sock;
 731     dispatcher_add(&dev->dispatcher, sock, dev, vubr_backend_recv_cb);
 732     DPRINT("Waiting for data from udp backend on %s:%d...\n",
 733            local_host, lport);
 734 }
 735
 736 static void
 737 vubr_run(VubrDev *dev)
 738 {
 739     while (!dev->quit) {
 740         /* timeout 200ms */
 741         dispatcher_wait(&dev->dispatcher, 200000);
 742         /* Here one can try polling strategy. */
 743     }
 744 }
 745
 746 static int
 747 vubr_parse_host_port(const char **host, const char **port, const char *buf)
 748 {
 749     char *p = strchr(buf, ':');
 750
 751     if (!p) {
 752         return -1;
 753     }
 754     *p = '\0';
 755     *host = strdup(buf);
 756     *port = strdup(p + 1);
 757     return 0;
 758 }
 759
 760 #define DEFAULT_UD_SOCKET "/tmp/vubr.sock"
 761 #define DEFAULT_LHOST "127.0.0.1"
 762 #define DEFAULT_LPORT "4444"
 763 #define DEFAULT_RHOST "127.0.0.1"
 764 #define DEFAULT_RPORT "5555"
 765
 766 static const char *ud_socket_path = DEFAULT_UD_SOCKET;
 767 static const char *lhost = DEFAULT_LHOST;
 768 static const char *lport = DEFAULT_LPORT;
 769 static const char *rhost = DEFAULT_RHOST;
 770 static const char *rport = DEFAULT_RPORT;
 771
 772 int
 773 main(int argc, char *argv[])
 774 {
 775     VubrDev *dev;
 776     int opt;
 777     bool client = false;
 778     bool host_notifier = false;
 779
 780     while ((opt = getopt(argc, argv, "l:r:u:cH")) != -1) {
 781
 782         switch (opt) {
 783         case 'l':
 784             if (vubr_parse_host_port(&lhost, &lport, optarg) < 0) {
 785                 goto out;
 786             }
 787             break;
 788         case 'r':
 789             if (vubr_parse_host_port(&rhost, &rport, optarg) < 0) {
 790                 goto out;
 791             }
 792             break;
 793         case 'u':
 794             ud_socket_path = strdup(optarg);
 795             break;
 796         case 'c':
 797             client = true;
 798             break;
 799         case 'H':
 800             host_notifier = true;
 801             break;
 802         default:
 803             goto out;
 804         }
 805     }
 806
 807     DPRINT("ud socket: %s (%s)\n", ud_socket_path,
 808            client ? "client" : "server");
 809     DPRINT("local:     %s:%s\n", lhost, lport);
 810     DPRINT("remote:    %s:%s\n", rhost, rport);
 811
 812     dev = vubr_new(ud_socket_path, client);
 813     if (!dev) {
 814         return 1;
 815     }
 816
 817     if (host_notifier) {
 818         vubr_host_notifier_setup(dev);
 819     }
 820
 821     vubr_backend_udp_setup(dev, lhost, lport, rhost, rport);
 822     vubr_run(dev);
 823
 824     vu_deinit(&dev->vudev);
 825
 826     return 0;
 827
 828 out:
 829     fprintf(stderr, "Usage: %s ", argv[0]);
 830     fprintf(stderr, "[-c] [-H] [-u ud_socket_path] [-l lhost:lport] [-r rhost:rport]\n");
 831     fprintf(stderr, "\t-u path to unix domain socket. default: %s\n",
 832             DEFAULT_UD_SOCKET);
 833     fprintf(stderr, "\t-l local host and port. default: %s:%s\n",
 834             DEFAULT_LHOST, DEFAULT_LPORT);
 835     fprintf(stderr, "\t-r remote host and port. default: %s:%s\n",
 836             DEFAULT_RHOST, DEFAULT_RPORT);
 837     fprintf(stderr, "\t-c client mode\n");
 838     fprintf(stderr, "\t-H use host notifier\n");
 839
 840     return 1;
 841 }