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