net/socket.c

   1 /*
   2  * QEMU System Emulator
   3  *
   4  * Copyright (c) 2003-2008 Fabrice Bellard
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a copy
   7  * of this software and associated documentation files (the "Software"), to deal
   8  * in the Software without restriction, including without limitation the rights
   9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  10  * copies of the Software, and to permit persons to whom the Software is
  11  * furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included in
  14  * all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  22  * THE SOFTWARE.
  23  */
  24 #include "config-host.h"
  25
  26 #include "net/net.h"
  27 #include "clients.h"
  28 #include "monitor/monitor.h"
  29 #include "qemu-common.h"
  30 #include "qemu/error-report.h"
  31 #include "qemu/option.h"
  32 #include "qemu/sockets.h"
  33 #include "qemu/iov.h"
  34
  35 typedef struct NetSocketState {
  36     NetClientState nc;
  37     int listen_fd;
  38     int fd;
  39     int state; /* 0 = getting length, 1 = getting data */
  40     unsigned int index;
  41     unsigned int packet_len;
  42     unsigned int send_index;      /* number of bytes sent (only SOCK_STREAM) */
  43     uint8_t buf[NET_BUFSIZE];
  44     struct sockaddr_in dgram_dst; /* contains inet host and port destination iff connectionless (SOCK_DGRAM) */
  45     IOHandler *send_fn;           /* differs between SOCK_STREAM/SOCK_DGRAM */
  46     bool read_poll;               /* waiting to receive data? */
  47     bool write_poll;              /* waiting to transmit data? */
  48 } NetSocketState;
  49
  50 static void net_socket_accept(void *opaque);
  51 static void net_socket_writable(void *opaque);
  52
  53 /* Only read packets from socket when peer can receive them */
  54 static int net_socket_can_send(void *opaque)
  55 {
  56     NetSocketState *s = opaque;
  57
  58     return qemu_can_send_packet(&s->nc);
  59 }
  60
  61 static void net_socket_update_fd_handler(NetSocketState *s)
  62 {
  63     qemu_set_fd_handler2(s->fd,
  64                          s->read_poll  ? net_socket_can_send : NULL,
  65                          s->read_poll  ? s->send_fn : NULL,
  66                          s->write_poll ? net_socket_writable : NULL,
  67                          s);
  68 }
  69
  70 static void net_socket_read_poll(NetSocketState *s, bool enable)
  71 {
  72     s->read_poll = enable;
  73     net_socket_update_fd_handler(s);
  74 }
  75
  76 static void net_socket_write_poll(NetSocketState *s, bool enable)
  77 {
  78     s->write_poll = enable;
  79     net_socket_update_fd_handler(s);
  80 }
  81
  82 static void net_socket_writable(void *opaque)
  83 {
  84     NetSocketState *s = opaque;
  85
  86     net_socket_write_poll(s, false);
  87
  88     qemu_flush_queued_packets(&s->nc);
  89 }
  90
  91 static ssize_t net_socket_receive(NetClientState *nc, const uint8_t *buf, size_t size)
  92 {
  93     NetSocketState *s = DO_UPCAST(NetSocketState, nc, nc);
  94     uint32_t len = htonl(size);
  95     struct iovec iov[] = {
  96         {
  97             .iov_base = &len,
  98             .iov_len  = sizeof(len),
  99         }, {
 100             .iov_base = (void *)buf,
 101             .iov_len  = size,
 102         },
 103     };
 104     size_t remaining;
 105     ssize_t ret;
 106
 107     remaining = iov_size(iov, 2) - s->send_index;
 108     ret = iov_send(s->fd, iov, 2, s->send_index, remaining);
 109
 110     if (ret == -1 && errno == EAGAIN) {
 111         ret = 0; /* handled further down */
 112     }
 113     if (ret == -1) {
 114         s->send_index = 0;
 115         return -errno;
 116     }
 117     if (ret < (ssize_t)remaining) {
 118         s->send_index += ret;
 119         net_socket_write_poll(s, true);
 120         return 0;
 121     }
 122     s->send_index = 0;
 123     return size;
 124 }
 125
 126 static ssize_t net_socket_receive_dgram(NetClientState *nc, const uint8_t *buf, size_t size)
 127 {
 128     NetSocketState *s = DO_UPCAST(NetSocketState, nc, nc);
 129     ssize_t ret;
 130
 131     do {
 132         ret = qemu_sendto(s->fd, buf, size, 0,
 133                           (struct sockaddr *)&s->dgram_dst,
 134                           sizeof(s->dgram_dst));
 135     } while (ret == -1 && errno == EINTR);
 136
 137     if (ret == -1 && errno == EAGAIN) {
 138         net_socket_write_poll(s, true);
 139         return 0;
 140     }
 141     return ret;
 142 }
 143
 144 static void net_socket_send(void *opaque)
 145 {
 146     NetSocketState *s = opaque;
 147     int size, err;
 148     unsigned l;
 149     uint8_t buf1[NET_BUFSIZE];
 150     const uint8_t *buf;
 151
 152     size = qemu_recv(s->fd, buf1, sizeof(buf1), 0);
 153     if (size < 0) {
 154         err = socket_error();
 155         if (err != EWOULDBLOCK)
 156             goto eoc;
 157     } else if (size == 0) {
 158         /* end of connection */
 159     eoc:
 160         net_socket_read_poll(s, false);
 161         net_socket_write_poll(s, false);
 162         if (s->listen_fd != -1) {
 163             qemu_set_fd_handler(s->listen_fd, net_socket_accept, NULL, s);
 164         }
 165         closesocket(s->fd);
 166
 167         s->fd = -1;
 168         s->state = 0;
 169         s->index = 0;
 170         s->packet_len = 0;
 171         s->nc.link_down = true;
 172         memset(s->buf, 0, sizeof(s->buf));
 173         memset(s->nc.info_str, 0, sizeof(s->nc.info_str));
 174
 175         return;
 176     }
 177     buf = buf1;
 178     while (size > 0) {
 179         /* reassemble a packet from the network */
 180         switch(s->state) {
 181         case 0:
 182             l = 4 - s->index;
 183             if (l > size)
 184                 l = size;
 185             memcpy(s->buf + s->index, buf, l);
 186             buf += l;
 187             size -= l;
 188             s->index += l;
 189             if (s->index == 4) {
 190                 /* got length */
 191                 s->packet_len = ntohl(*(uint32_t *)s->buf);
 192                 s->index = 0;
 193                 s->state = 1;
 194             }
 195             break;
 196         case 1:
 197             l = s->packet_len - s->index;
 198             if (l > size)
 199                 l = size;
 200             if (s->index + l <= sizeof(s->buf)) {
 201                 memcpy(s->buf + s->index, buf, l);
 202             } else {
 203                 fprintf(stderr, "serious error: oversized packet received,"
 204                     "connection terminated.\n");
 205                 s->state = 0;
 206                 goto eoc;
 207             }
 208
 209             s->index += l;
 210             buf += l;
 211             size -= l;
 212             if (s->index >= s->packet_len) {
 213                 qemu_send_packet(&s->nc, s->buf, s->packet_len);
 214                 s->index = 0;
 215                 s->state = 0;
 216             }
 217             break;
 218         }
 219     }
 220 }
 221
 222 static void net_socket_send_dgram(void *opaque)
 223 {
 224     NetSocketState *s = opaque;
 225     int size;
 226
 227     size = qemu_recv(s->fd, s->buf, sizeof(s->buf), 0);
 228     if (size < 0)
 229         return;
 230     if (size == 0) {
 231         /* end of connection */
 232         net_socket_read_poll(s, false);
 233         net_socket_write_poll(s, false);
 234         return;
 235     }
 236     qemu_send_packet(&s->nc, s->buf, size);
 237 }
 238
 239 static int net_socket_mcast_create(struct sockaddr_in *mcastaddr, struct in_addr *localaddr)
 240 {
 241     struct ip_mreq imr;
 242     int fd;
 243     int val, ret;
 244 #ifdef __OpenBSD__
 245     unsigned char loop;
 246 #else
 247     int loop;
 248 #endif
 249
 250     if (!IN_MULTICAST(ntohl(mcastaddr->sin_addr.s_addr))) {
 251         fprintf(stderr, "qemu: error: specified mcastaddr \"%s\" (0x%08x) "
 252                 "does not contain a multicast address\n",
 253                 inet_ntoa(mcastaddr->sin_addr),
 254                 (int)ntohl(mcastaddr->sin_addr.s_addr));
 255         return -1;
 256
 257     }
 258     fd = qemu_socket(PF_INET, SOCK_DGRAM, 0);
 259     if (fd < 0) {
 260         perror("socket(PF_INET, SOCK_DGRAM)");
 261         return -1;
 262     }
 263
 264     val = 1;
 265     ret = qemu_setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
 266     if (ret < 0) {
 267         perror("setsockopt(SOL_SOCKET, SO_REUSEADDR)");
 268         goto fail;
 269     }
 270
 271     ret = bind(fd, (struct sockaddr *)mcastaddr, sizeof(*mcastaddr));
 272     if (ret < 0) {
 273         perror("bind");
 274         goto fail;
 275     }
 276
 277     /* Add host to multicast group */
 278     imr.imr_multiaddr = mcastaddr->sin_addr;
 279     if (localaddr) {
 280         imr.imr_interface = *localaddr;
 281     } else {
 282         imr.imr_interface.s_addr = htonl(INADDR_ANY);
 283     }
 284
 285     ret = qemu_setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
 286                           &imr, sizeof(struct ip_mreq));
 287     if (ret < 0) {
 288         perror("setsockopt(IP_ADD_MEMBERSHIP)");
 289         goto fail;
 290     }
 291
 292     /* Force mcast msgs to loopback (eg. several QEMUs in same host */
 293     loop = 1;
 294     ret = qemu_setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP,
 295                           &loop, sizeof(loop));
 296     if (ret < 0) {
 297         perror("setsockopt(SOL_IP, IP_MULTICAST_LOOP)");
 298         goto fail;
 299     }
 300
 301     /* If a bind address is given, only send packets from that address */
 302     if (localaddr != NULL) {
 303         ret = qemu_setsockopt(fd, IPPROTO_IP, IP_MULTICAST_IF,
 304                               localaddr, sizeof(*localaddr));
 305         if (ret < 0) {
 306             perror("setsockopt(IP_MULTICAST_IF)");
 307             goto fail;
 308         }
 309     }
 310
 311     socket_set_nonblock(fd);
 312     return fd;
 313 fail:
 314     if (fd >= 0)
 315         closesocket(fd);
 316     return -1;
 317 }
 318
 319 static void net_socket_cleanup(NetClientState *nc)
 320 {
 321     NetSocketState *s = DO_UPCAST(NetSocketState, nc, nc);
 322     if (s->fd != -1) {
 323         net_socket_read_poll(s, false);
 324         net_socket_write_poll(s, false);
 325         close(s->fd);
 326         s->fd = -1;
 327     }
 328     if (s->listen_fd != -1) {
 329         qemu_set_fd_handler(s->listen_fd, NULL, NULL, NULL);
 330         closesocket(s->listen_fd);
 331         s->listen_fd = -1;
 332     }
 333 }
 334
 335 static NetClientInfo net_dgram_socket_info = {
 336     .type = NET_CLIENT_OPTIONS_KIND_SOCKET,
 337     .size = sizeof(NetSocketState),
 338     .receive = net_socket_receive_dgram,
 339     .cleanup = net_socket_cleanup,
 340 };
 341
 342 static NetSocketState *net_socket_fd_init_dgram(NetClientState *peer,
 343                                                 const char *model,
 344                                                 const char *name,
 345                                                 int fd, int is_connected)
 346 {
 347     struct sockaddr_in saddr;
 348     int newfd;
 349     socklen_t saddr_len;
 350     NetClientState *nc;
 351     NetSocketState *s;
 352
 353     /* fd passed: multicast: "learn" dgram_dst address from bound address and save it
 354      * Because this may be "shared" socket from a "master" process, datagrams would be recv()
 355      * by ONLY ONE process: we must "clone" this dgram socket --jjo
 356      */
 357
 358     if (is_connected) {
 359         if (getsockname(fd, (struct sockaddr *) &saddr, &saddr_len) == 0) {
 360             /* must be bound */
 361             if (saddr.sin_addr.s_addr == 0) {
 362                 fprintf(stderr, "qemu: error: init_dgram: fd=%d unbound, "
 363                         "cannot setup multicast dst addr\n", fd);
 364                 goto err;
 365             }
 366             /* clone dgram socket */
 367             newfd = net_socket_mcast_create(&saddr, NULL);
 368             if (newfd < 0) {
 369                 /* error already reported by net_socket_mcast_create() */
 370                 goto err;
 371             }
 372             /* clone newfd to fd, close newfd */
 373             dup2(newfd, fd);
 374             close(newfd);
 375
 376         } else {
 377             fprintf(stderr,
 378                     "qemu: error: init_dgram: fd=%d failed getsockname(): %s\n",
 379                     fd, strerror(errno));
 380             goto err;
 381         }
 382     }
 383
 384     nc = qemu_new_net_client(&net_dgram_socket_info, peer, model, name);
 385
 386     snprintf(nc->info_str, sizeof(nc->info_str),
 387             "socket: fd=%d (%s mcast=%s:%d)",
 388             fd, is_connected ? "cloned" : "",
 389             inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
 390
 391     s = DO_UPCAST(NetSocketState, nc, nc);
 392
 393     s->fd = fd;
 394     s->listen_fd = -1;
 395     s->send_fn = net_socket_send_dgram;
 396     net_socket_read_poll(s, true);
 397
 398     /* mcast: save bound address as dst */
 399     if (is_connected) {
 400         s->dgram_dst = saddr;
 401     }
 402
 403     return s;
 404
 405 err:
 406     closesocket(fd);
 407     return NULL;
 408 }
 409
 410 static void net_socket_connect(void *opaque)
 411 {
 412     NetSocketState *s = opaque;
 413     s->send_fn = net_socket_send;
 414     net_socket_read_poll(s, true);
 415 }
 416
 417 static NetClientInfo net_socket_info = {
 418     .type = NET_CLIENT_OPTIONS_KIND_SOCKET,
 419     .size = sizeof(NetSocketState),
 420     .receive = net_socket_receive,
 421     .cleanup = net_socket_cleanup,
 422 };
 423
 424 static NetSocketState *net_socket_fd_init_stream(NetClientState *peer,
 425                                                  const char *model,
 426                                                  const char *name,
 427                                                  int fd, int is_connected)
 428 {
 429     NetClientState *nc;
 430     NetSocketState *s;
 431
 432     nc = qemu_new_net_client(&net_socket_info, peer, model, name);
 433
 434     snprintf(nc->info_str, sizeof(nc->info_str), "socket: fd=%d", fd);
 435
 436     s = DO_UPCAST(NetSocketState, nc, nc);
 437
 438     s->fd = fd;
 439     s->listen_fd = -1;
 440
 441     /* Disable Nagle algorithm on TCP sockets to reduce latency */
 442     socket_set_nodelay(fd);
 443
 444     if (is_connected) {
 445         net_socket_connect(s);
 446     } else {
 447         qemu_set_fd_handler(s->fd, NULL, net_socket_connect, s);
 448     }
 449     return s;
 450 }
 451
 452 static NetSocketState *net_socket_fd_init(NetClientState *peer,
 453                                           const char *model, const char *name,
 454                                           int fd, int is_connected)
 455 {
 456     int so_type = -1, optlen=sizeof(so_type);
 457
 458     if(getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&so_type,
 459         (socklen_t *)&optlen)< 0) {
 460         fprintf(stderr, "qemu: error: getsockopt(SO_TYPE) for fd=%d failed\n",
 461                 fd);
 462         closesocket(fd);
 463         return NULL;
 464     }
 465     switch(so_type) {
 466     case SOCK_DGRAM:
 467         return net_socket_fd_init_dgram(peer, model, name, fd, is_connected);
 468     case SOCK_STREAM:
 469         return net_socket_fd_init_stream(peer, model, name, fd, is_connected);
 470     default:
 471         /* who knows ... this could be a eg. a pty, do warn and continue as stream */
 472         fprintf(stderr, "qemu: warning: socket type=%d for fd=%d is not SOCK_DGRAM or SOCK_STREAM\n", so_type, fd);
 473         return net_socket_fd_init_stream(peer, model, name, fd, is_connected);
 474     }
 475     return NULL;
 476 }
 477
 478 static void net_socket_accept(void *opaque)
 479 {
 480     NetSocketState *s = opaque;
 481     struct sockaddr_in saddr;
 482     socklen_t len;
 483     int fd;
 484
 485     for(;;) {
 486         len = sizeof(saddr);
 487         fd = qemu_accept(s->listen_fd, (struct sockaddr *)&saddr, &len);
 488         if (fd < 0 && errno != EINTR) {
 489             return;
 490         } else if (fd >= 0) {
 491             qemu_set_fd_handler(s->listen_fd, NULL, NULL, NULL);
 492             break;
 493         }
 494     }
 495
 496     s->fd = fd;
 497     s->nc.link_down = false;
 498     net_socket_connect(s);
 499     snprintf(s->nc.info_str, sizeof(s->nc.info_str),
 500              "socket: connection from %s:%d",
 501              inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
 502 }
 503
 504 static int net_socket_listen_init(NetClientState *peer,
 505                                   const char *model,
 506                                   const char *name,
 507                                   const char *host_str)
 508 {
 509     NetClientState *nc;
 510     NetSocketState *s;
 511     struct sockaddr_in saddr;
 512     int fd, val, ret;
 513
 514     if (parse_host_port(&saddr, host_str) < 0)
 515         return -1;
 516
 517     fd = qemu_socket(PF_INET, SOCK_STREAM, 0);
 518     if (fd < 0) {
 519         perror("socket");
 520         return -1;
 521     }
 522     socket_set_nonblock(fd);
 523
 524     /* allow fast reuse */
 525     val = 1;
 526     qemu_setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
 527
 528     ret = bind(fd, (struct sockaddr *)&saddr, sizeof(saddr));
 529     if (ret < 0) {
 530         perror("bind");
 531         closesocket(fd);
 532         return -1;
 533     }
 534     ret = listen(fd, 0);
 535     if (ret < 0) {
 536         perror("listen");
 537         closesocket(fd);
 538         return -1;
 539     }
 540
 541     nc = qemu_new_net_client(&net_socket_info, peer, model, name);
 542     s = DO_UPCAST(NetSocketState, nc, nc);
 543     s->fd = -1;
 544     s->listen_fd = fd;
 545     s->nc.link_down = true;
 546
 547     qemu_set_fd_handler(s->listen_fd, net_socket_accept, NULL, s);
 548     return 0;
 549 }
 550
 551 static int net_socket_connect_init(NetClientState *peer,
 552                                    const char *model,
 553                                    const char *name,
 554                                    const char *host_str)
 555 {
 556     NetSocketState *s;
 557     int fd, connected, ret, err;
 558     struct sockaddr_in saddr;
 559
 560     if (parse_host_port(&saddr, host_str) < 0)
 561         return -1;
 562
 563     fd = qemu_socket(PF_INET, SOCK_STREAM, 0);
 564     if (fd < 0) {
 565         perror("socket");
 566         return -1;
 567     }
 568     socket_set_nonblock(fd);
 569
 570     connected = 0;
 571     for(;;) {
 572         ret = connect(fd, (struct sockaddr *)&saddr, sizeof(saddr));
 573         if (ret < 0) {
 574             err = socket_error();
 575             if (err == EINTR || err == EWOULDBLOCK) {
 576             } else if (err == EINPROGRESS) {
 577                 break;
 578 #ifdef _WIN32
 579             } else if (err == WSAEALREADY || err == WSAEINVAL) {
 580                 break;
 581 #endif
 582             } else {
 583                 perror("connect");
 584                 closesocket(fd);
 585                 return -1;
 586             }
 587         } else {
 588             connected = 1;
 589             break;
 590         }
 591     }
 592     s = net_socket_fd_init(peer, model, name, fd, connected);
 593     if (!s)
 594         return -1;
 595     snprintf(s->nc.info_str, sizeof(s->nc.info_str),
 596              "socket: connect to %s:%d",
 597              inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
 598     return 0;
 599 }
 600
 601 static int net_socket_mcast_init(NetClientState *peer,
 602                                  const char *model,
 603                                  const char *name,
 604                                  const char *host_str,
 605                                  const char *localaddr_str)
 606 {
 607     NetSocketState *s;
 608     int fd;
 609     struct sockaddr_in saddr;
 610     struct in_addr localaddr, *param_localaddr;
 611
 612     if (parse_host_port(&saddr, host_str) < 0)
 613         return -1;
 614
 615     if (localaddr_str != NULL) {
 616         if (inet_aton(localaddr_str, &localaddr) == 0)
 617             return -1;
 618         param_localaddr = &localaddr;
 619     } else {
 620         param_localaddr = NULL;
 621     }
 622
 623     fd = net_socket_mcast_create(&saddr, param_localaddr);
 624     if (fd < 0)
 625         return -1;
 626
 627     s = net_socket_fd_init(peer, model, name, fd, 0);
 628     if (!s)
 629         return -1;
 630
 631     s->dgram_dst = saddr;
 632
 633     snprintf(s->nc.info_str, sizeof(s->nc.info_str),
 634              "socket: mcast=%s:%d",
 635              inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
 636     return 0;
 637
 638 }
 639
 640 static int net_socket_udp_init(NetClientState *peer,
 641                                  const char *model,
 642                                  const char *name,
 643                                  const char *rhost,
 644                                  const char *lhost)
 645 {
 646     NetSocketState *s;
 647     int fd, val, ret;
 648     struct sockaddr_in laddr, raddr;
 649
 650     if (parse_host_port(&laddr, lhost) < 0) {
 651         return -1;
 652     }
 653
 654     if (parse_host_port(&raddr, rhost) < 0) {
 655         return -1;
 656     }
 657
 658     fd = qemu_socket(PF_INET, SOCK_DGRAM, 0);
 659     if (fd < 0) {
 660         perror("socket(PF_INET, SOCK_DGRAM)");
 661         return -1;
 662     }
 663     val = 1;
 664     ret = qemu_setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
 665                           &val, sizeof(val));
 666     if (ret < 0) {
 667         perror("setsockopt(SOL_SOCKET, SO_REUSEADDR)");
 668         closesocket(fd);
 669         return -1;
 670     }
 671     ret = bind(fd, (struct sockaddr *)&laddr, sizeof(laddr));
 672     if (ret < 0) {
 673         perror("bind");
 674         closesocket(fd);
 675         return -1;
 676     }
 677
 678     s = net_socket_fd_init(peer, model, name, fd, 0);
 679     if (!s) {
 680         return -1;
 681     }
 682
 683     s->dgram_dst = raddr;
 684
 685     snprintf(s->nc.info_str, sizeof(s->nc.info_str),
 686              "socket: udp=%s:%d",
 687              inet_ntoa(raddr.sin_addr), ntohs(raddr.sin_port));
 688     return 0;
 689 }
 690
 691 int net_init_socket(const NetClientOptions *opts, const char *name,
 692                     NetClientState *peer)
 693 {
 694     const NetdevSocketOptions *sock;
 695
 696     assert(opts->kind == NET_CLIENT_OPTIONS_KIND_SOCKET);
 697     sock = opts->socket;
 698
 699     if (sock->has_fd + sock->has_listen + sock->has_connect + sock->has_mcast +
 700         sock->has_udp != 1) {
 701         error_report("exactly one of fd=, listen=, connect=, mcast= or udp="
 702                      " is required");
 703         return -1;
 704     }
 705
 706     if (sock->has_localaddr && !sock->has_mcast && !sock->has_udp) {
 707         error_report("localaddr= is only valid with mcast= or udp=");
 708         return -1;
 709     }
 710
 711     if (sock->has_fd) {
 712         int fd;
 713
 714         fd = monitor_handle_fd_param(cur_mon, sock->fd);
 715         if (fd == -1 || !net_socket_fd_init(peer, "socket", name, fd, 1)) {
 716             return -1;
 717         }
 718         return 0;
 719     }
 720
 721     if (sock->has_listen) {
 722         if (net_socket_listen_init(peer, "socket", name, sock->listen) == -1) {
 723             return -1;
 724         }
 725         return 0;
 726     }
 727
 728     if (sock->has_connect) {
 729         if (net_socket_connect_init(peer, "socket", name, sock->connect) ==
 730             -1) {
 731             return -1;
 732         }
 733         return 0;
 734     }
 735
 736     if (sock->has_mcast) {
 737         /* if sock->localaddr is missing, it has been initialized to "all bits
 738          * zero" */
 739         if (net_socket_mcast_init(peer, "socket", name, sock->mcast,
 740             sock->localaddr) == -1) {
 741             return -1;
 742         }
 743         return 0;
 744     }
 745
 746     assert(sock->has_udp);
 747     if (!sock->has_localaddr) {
 748         error_report("localaddr= is mandatory with udp=");
 749         return -1;
 750     }
 751     if (net_socket_udp_init(peer, "socket", name, sock->udp, sock->localaddr) ==
 752         -1) {
 753         return -1;
 754     }
 755     return 0;
 756 }