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 "qemu/osdep.h"
  25
  26 #include "net/net.h"
  27 #include "clients.h"
  28 #include "monitor/monitor.h"
  29 #include "qapi/error.h"
  30 #include "qemu/error-report.h"
  31 #include "qemu/option.h"
  32 #include "qemu/sockets.h"
  33 #include "qemu/iov.h"
  34 #include "qemu/main-loop.h"
  35
  36 typedef struct NetSocketState {
  37     NetClientState nc;
  38     int listen_fd;
  39     int fd;
  40     SocketReadState rs;
  41     unsigned int send_index;      /* number of bytes sent (only SOCK_STREAM) */
  42     struct sockaddr_in dgram_dst; /* contains inet host and port destination iff connectionless (SOCK_DGRAM) */
  43     IOHandler *send_fn;           /* differs between SOCK_STREAM/SOCK_DGRAM */
  44     bool read_poll;               /* waiting to receive data? */
  45     bool write_poll;              /* waiting to transmit data? */
  46 } NetSocketState;
  47
  48 static void net_socket_accept(void *opaque);
  49 static void net_socket_writable(void *opaque);
  50
  51 static void net_socket_update_fd_handler(NetSocketState *s)
  52 {
  53     qemu_set_fd_handler(s->fd,
  54                         s->read_poll ? s->send_fn : NULL,
  55                         s->write_poll ? net_socket_writable : NULL,
  56                         s);
  57 }
  58
  59 static void net_socket_read_poll(NetSocketState *s, bool enable)
  60 {
  61     s->read_poll = enable;
  62     net_socket_update_fd_handler(s);
  63 }
  64
  65 static void net_socket_write_poll(NetSocketState *s, bool enable)
  66 {
  67     s->write_poll = enable;
  68     net_socket_update_fd_handler(s);
  69 }
  70
  71 static void net_socket_writable(void *opaque)
  72 {
  73     NetSocketState *s = opaque;
  74
  75     net_socket_write_poll(s, false);
  76
  77     qemu_flush_queued_packets(&s->nc);
  78 }
  79
  80 static ssize_t net_socket_receive(NetClientState *nc, const uint8_t *buf, size_t size)
  81 {
  82     NetSocketState *s = DO_UPCAST(NetSocketState, nc, nc);
  83     uint32_t len = htonl(size);
  84     struct iovec iov[] = {
  85         {
  86             .iov_base = &len,
  87             .iov_len  = sizeof(len),
  88         }, {
  89             .iov_base = (void *)buf,
  90             .iov_len  = size,
  91         },
  92     };
  93     size_t remaining;
  94     ssize_t ret;
  95
  96     remaining = iov_size(iov, 2) - s->send_index;
  97     ret = iov_send(s->fd, iov, 2, s->send_index, remaining);
  98
  99     if (ret == -1 && errno == EAGAIN) {
 100         ret = 0; /* handled further down */
 101     }
 102     if (ret == -1) {
 103         s->send_index = 0;
 104         return -errno;
 105     }
 106     if (ret < (ssize_t)remaining) {
 107         s->send_index += ret;
 108         net_socket_write_poll(s, true);
 109         return 0;
 110     }
 111     s->send_index = 0;
 112     return size;
 113 }
 114
 115 static ssize_t net_socket_receive_dgram(NetClientState *nc, const uint8_t *buf, size_t size)
 116 {
 117     NetSocketState *s = DO_UPCAST(NetSocketState, nc, nc);
 118     ssize_t ret;
 119
 120     ret = RETRY_ON_EINTR(
 121         s->dgram_dst.sin_family != AF_UNIX ?
 122             sendto(s->fd, buf, size, 0,
 123                      (struct sockaddr *)&s->dgram_dst,
 124                      sizeof(s->dgram_dst)) :
 125             send(s->fd, buf, size, 0)
 126     );
 127
 128     if (ret == -1 && errno == EAGAIN) {
 129         net_socket_write_poll(s, true);
 130         return 0;
 131     }
 132     return ret;
 133 }
 134
 135 static void net_socket_send_completed(NetClientState *nc, ssize_t len)
 136 {
 137     NetSocketState *s = DO_UPCAST(NetSocketState, nc, nc);
 138
 139     if (!s->read_poll) {
 140         net_socket_read_poll(s, true);
 141     }
 142 }
 143
 144 static void net_socket_rs_finalize(SocketReadState *rs)
 145 {
 146     NetSocketState *s = container_of(rs, NetSocketState, rs);
 147
 148     if (qemu_send_packet_async(&s->nc, rs->buf,
 149                                rs->packet_len,
 150                                net_socket_send_completed) == 0) {
 151         net_socket_read_poll(s, false);
 152     }
 153 }
 154
 155 static void net_socket_send(void *opaque)
 156 {
 157     NetSocketState *s = opaque;
 158     int size;
 159     int ret;
 160     uint8_t buf1[NET_BUFSIZE];
 161     const uint8_t *buf;
 162
 163     size = recv(s->fd, buf1, sizeof(buf1), 0);
 164     if (size < 0) {
 165         if (errno != EWOULDBLOCK)
 166             goto eoc;
 167     } else if (size == 0) {
 168         /* end of connection */
 169     eoc:
 170         net_socket_read_poll(s, false);
 171         net_socket_write_poll(s, false);
 172         if (s->listen_fd != -1) {
 173             qemu_set_fd_handler(s->listen_fd, net_socket_accept, NULL, s);
 174         }
 175         close(s->fd);
 176
 177         s->fd = -1;
 178         net_socket_rs_init(&s->rs, net_socket_rs_finalize, false);
 179         s->nc.link_down = true;
 180         qemu_set_info_str(&s->nc, "%s", "");
 181
 182         return;
 183     }
 184     buf = buf1;
 185
 186     ret = net_fill_rstate(&s->rs, buf, size);
 187
 188     if (ret == -1) {
 189         goto eoc;
 190     }
 191 }
 192
 193 static void net_socket_send_dgram(void *opaque)
 194 {
 195     NetSocketState *s = opaque;
 196     int size;
 197
 198     size = recv(s->fd, s->rs.buf, sizeof(s->rs.buf), 0);
 199     if (size < 0)
 200         return;
 201     if (size == 0) {
 202         /* end of connection */
 203         net_socket_read_poll(s, false);
 204         net_socket_write_poll(s, false);
 205         return;
 206     }
 207     if (qemu_send_packet_async(&s->nc, s->rs.buf, size,
 208                                net_socket_send_completed) == 0) {
 209         net_socket_read_poll(s, false);
 210     }
 211 }
 212
 213 static int net_socket_mcast_create(struct sockaddr_in *mcastaddr,
 214                                    struct in_addr *localaddr,
 215                                    Error **errp)
 216 {
 217     struct ip_mreq imr;
 218     int fd;
 219     int val, ret;
 220 #ifdef __OpenBSD__
 221     unsigned char loop;
 222 #else
 223     int loop;
 224 #endif
 225
 226     if (!IN_MULTICAST(ntohl(mcastaddr->sin_addr.s_addr))) {
 227         error_setg(errp, "specified mcastaddr %s (0x%08x) "
 228                    "does not contain a multicast address",
 229                    inet_ntoa(mcastaddr->sin_addr),
 230                    (int)ntohl(mcastaddr->sin_addr.s_addr));
 231         return -1;
 232     }
 233
 234     fd = qemu_socket(PF_INET, SOCK_DGRAM, 0);
 235     if (fd < 0) {
 236         error_setg_errno(errp, errno, "can't create datagram socket");
 237         return -1;
 238     }
 239
 240     /* Allow multiple sockets to bind the same multicast ip and port by setting
 241      * SO_REUSEADDR. This is the only situation where SO_REUSEADDR should be set
 242      * on windows. Use socket_set_fast_reuse otherwise as it sets SO_REUSEADDR
 243      * only on posix systems.
 244      */
 245     val = 1;
 246     ret = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
 247     if (ret < 0) {
 248         error_setg_errno(errp, errno,
 249                          "can't set socket option SO_REUSEADDR");
 250         goto fail;
 251     }
 252
 253     ret = bind(fd, (struct sockaddr *)mcastaddr, sizeof(*mcastaddr));
 254     if (ret < 0) {
 255         error_setg_errno(errp, errno, "can't bind ip=%s to socket",
 256                          inet_ntoa(mcastaddr->sin_addr));
 257         goto fail;
 258     }
 259
 260     /* Add host to multicast group */
 261     imr.imr_multiaddr = mcastaddr->sin_addr;
 262     if (localaddr) {
 263         imr.imr_interface = *localaddr;
 264     } else {
 265         imr.imr_interface.s_addr = htonl(INADDR_ANY);
 266     }
 267
 268     ret = setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
 269                      &imr, sizeof(struct ip_mreq));
 270     if (ret < 0) {
 271         error_setg_errno(errp, errno,
 272                          "can't add socket to multicast group %s",
 273                          inet_ntoa(imr.imr_multiaddr));
 274         goto fail;
 275     }
 276
 277     /* Force mcast msgs to loopback (eg. several QEMUs in same host */
 278     loop = 1;
 279     ret = setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP,
 280                      &loop, sizeof(loop));
 281     if (ret < 0) {
 282         error_setg_errno(errp, errno,
 283                          "can't force multicast message to loopback");
 284         goto fail;
 285     }
 286
 287     /* If a bind address is given, only send packets from that address */
 288     if (localaddr != NULL) {
 289         ret = setsockopt(fd, IPPROTO_IP, IP_MULTICAST_IF,
 290                          localaddr, sizeof(*localaddr));
 291         if (ret < 0) {
 292             error_setg_errno(errp, errno,
 293                              "can't set the default network send interface");
 294             goto fail;
 295         }
 296     }
 297
 298     qemu_socket_set_nonblock(fd);
 299     return fd;
 300 fail:
 301     if (fd >= 0)
 302         close(fd);
 303     return -1;
 304 }
 305
 306 static void net_socket_cleanup(NetClientState *nc)
 307 {
 308     NetSocketState *s = DO_UPCAST(NetSocketState, nc, nc);
 309     if (s->fd != -1) {
 310         net_socket_read_poll(s, false);
 311         net_socket_write_poll(s, false);
 312         close(s->fd);
 313         s->fd = -1;
 314     }
 315     if (s->listen_fd != -1) {
 316         qemu_set_fd_handler(s->listen_fd, NULL, NULL, NULL);
 317         close(s->listen_fd);
 318         s->listen_fd = -1;
 319     }
 320 }
 321
 322 static NetClientInfo net_dgram_socket_info = {
 323     .type = NET_CLIENT_DRIVER_SOCKET,
 324     .size = sizeof(NetSocketState),
 325     .receive = net_socket_receive_dgram,
 326     .cleanup = net_socket_cleanup,
 327 };
 328
 329 static NetSocketState *net_socket_fd_init_dgram(NetClientState *peer,
 330                                                 const char *model,
 331                                                 const char *name,
 332                                                 int fd, int is_connected,
 333                                                 const char *mcast,
 334                                                 Error **errp)
 335 {
 336     struct sockaddr_in saddr;
 337     int newfd;
 338     NetClientState *nc;
 339     NetSocketState *s;
 340     SocketAddress *sa;
 341     SocketAddressType sa_type;
 342
 343     sa = socket_local_address(fd, errp);
 344     if (!sa) {
 345         return NULL;
 346     }
 347     sa_type = sa->type;
 348     qapi_free_SocketAddress(sa);
 349
 350     /* fd passed: multicast: "learn" dgram_dst address from bound address and save it
 351      * Because this may be "shared" socket from a "master" process, datagrams would be recv()
 352      * by ONLY ONE process: we must "clone" this dgram socket --jjo
 353      */
 354
 355     if (is_connected && mcast != NULL) {
 356             if (parse_host_port(&saddr, mcast, errp) < 0) {
 357                 goto err;
 358             }
 359             /* must be bound */
 360             if (saddr.sin_addr.s_addr == 0) {
 361                 error_setg(errp, "can't setup multicast destination address");
 362                 goto err;
 363             }
 364             /* clone dgram socket */
 365             newfd = net_socket_mcast_create(&saddr, NULL, errp);
 366             if (newfd < 0) {
 367                 goto err;
 368             }
 369             /* clone newfd to fd, close newfd */
 370             dup2(newfd, fd);
 371             close(newfd);
 372
 373     }
 374
 375     nc = qemu_new_net_client(&net_dgram_socket_info, peer, model, name);
 376
 377     s = DO_UPCAST(NetSocketState, nc, nc);
 378
 379     s->fd = fd;
 380     s->listen_fd = -1;
 381     s->send_fn = net_socket_send_dgram;
 382     net_socket_rs_init(&s->rs, net_socket_rs_finalize, false);
 383     net_socket_read_poll(s, true);
 384
 385     /* mcast: save bound address as dst */
 386     if (is_connected && mcast != NULL) {
 387         s->dgram_dst = saddr;
 388         qemu_set_info_str(nc, "socket: fd=%d (cloned mcast=%s:%d)", fd,
 389                           inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
 390     } else {
 391         if (sa_type == SOCKET_ADDRESS_TYPE_UNIX) {
 392             s->dgram_dst.sin_family = AF_UNIX;
 393         }
 394
 395         qemu_set_info_str(nc, "socket: fd=%d %s", fd,
 396                           SocketAddressType_str(sa_type));
 397     }
 398
 399     return s;
 400
 401 err:
 402     close(fd);
 403     return NULL;
 404 }
 405
 406 static void net_socket_connect(void *opaque)
 407 {
 408     NetSocketState *s = opaque;
 409     s->send_fn = net_socket_send;
 410     net_socket_read_poll(s, true);
 411 }
 412
 413 static NetClientInfo net_socket_info = {
 414     .type = NET_CLIENT_DRIVER_SOCKET,
 415     .size = sizeof(NetSocketState),
 416     .receive = net_socket_receive,
 417     .cleanup = net_socket_cleanup,
 418 };
 419
 420 static NetSocketState *net_socket_fd_init_stream(NetClientState *peer,
 421                                                  const char *model,
 422                                                  const char *name,
 423                                                  int fd, int is_connected)
 424 {
 425     NetClientState *nc;
 426     NetSocketState *s;
 427
 428     nc = qemu_new_net_client(&net_socket_info, peer, model, name);
 429
 430     qemu_set_info_str(nc, "socket: fd=%d", fd);
 431
 432     s = DO_UPCAST(NetSocketState, nc, nc);
 433
 434     s->fd = fd;
 435     s->listen_fd = -1;
 436     net_socket_rs_init(&s->rs, net_socket_rs_finalize, false);
 437
 438     /* Disable Nagle algorithm on TCP sockets to reduce latency */
 439     socket_set_nodelay(fd);
 440
 441     if (is_connected) {
 442         net_socket_connect(s);
 443     } else {
 444         qemu_set_fd_handler(s->fd, NULL, net_socket_connect, s);
 445     }
 446     return s;
 447 }
 448
 449 static NetSocketState *net_socket_fd_init(NetClientState *peer,
 450                                           const char *model, const char *name,
 451                                           int fd, int is_connected,
 452                                           const char *mc, Error **errp)
 453 {
 454     int so_type = -1, optlen=sizeof(so_type);
 455
 456     if(getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&so_type,
 457         (socklen_t *)&optlen)< 0) {
 458         error_setg(errp, "can't get socket option SO_TYPE");
 459         close(fd);
 460         return NULL;
 461     }
 462     switch(so_type) {
 463     case SOCK_DGRAM:
 464         return net_socket_fd_init_dgram(peer, model, name, fd, is_connected,
 465                                         mc, errp);
 466     case SOCK_STREAM:
 467         return net_socket_fd_init_stream(peer, model, name, fd, is_connected);
 468     default:
 469         error_setg(errp, "socket type=%d for fd=%d must be either"
 470                    " SOCK_DGRAM or SOCK_STREAM", so_type, fd);
 471         close(fd);
 472     }
 473     return NULL;
 474 }
 475
 476 static void net_socket_accept(void *opaque)
 477 {
 478     NetSocketState *s = opaque;
 479     struct sockaddr_in saddr;
 480     socklen_t len;
 481     int fd;
 482
 483     for(;;) {
 484         len = sizeof(saddr);
 485         fd = qemu_accept(s->listen_fd, (struct sockaddr *)&saddr, &len);
 486         if (fd < 0 && errno != EINTR) {
 487             return;
 488         } else if (fd >= 0) {
 489             qemu_set_fd_handler(s->listen_fd, NULL, NULL, NULL);
 490             break;
 491         }
 492     }
 493
 494     s->fd = fd;
 495     s->nc.link_down = false;
 496     net_socket_connect(s);
 497     qemu_set_info_str(&s->nc, "socket: connection from %s:%d",
 498                       inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
 499 }
 500
 501 static int net_socket_listen_init(NetClientState *peer,
 502                                   const char *model,
 503                                   const char *name,
 504                                   const char *host_str,
 505                                   Error **errp)
 506 {
 507     NetClientState *nc;
 508     NetSocketState *s;
 509     struct sockaddr_in saddr;
 510     int fd, ret;
 511
 512     if (parse_host_port(&saddr, host_str, errp) < 0) {
 513         return -1;
 514     }
 515
 516     fd = qemu_socket(PF_INET, SOCK_STREAM, 0);
 517     if (fd < 0) {
 518         error_setg_errno(errp, errno, "can't create stream socket");
 519         return -1;
 520     }
 521     qemu_socket_set_nonblock(fd);
 522
 523     socket_set_fast_reuse(fd);
 524
 525     ret = bind(fd, (struct sockaddr *)&saddr, sizeof(saddr));
 526     if (ret < 0) {
 527         error_setg_errno(errp, errno, "can't bind ip=%s to socket",
 528                          inet_ntoa(saddr.sin_addr));
 529         close(fd);
 530         return -1;
 531     }
 532     ret = listen(fd, 0);
 533     if (ret < 0) {
 534         error_setg_errno(errp, errno, "can't listen on socket");
 535         close(fd);
 536         return -1;
 537     }
 538
 539     nc = qemu_new_net_client(&net_socket_info, peer, model, name);
 540     s = DO_UPCAST(NetSocketState, nc, nc);
 541     s->fd = -1;
 542     s->listen_fd = fd;
 543     s->nc.link_down = true;
 544     net_socket_rs_init(&s->rs, net_socket_rs_finalize, false);
 545
 546     qemu_set_fd_handler(s->listen_fd, net_socket_accept, NULL, s);
 547     return 0;
 548 }
 549
 550 static int net_socket_connect_init(NetClientState *peer,
 551                                    const char *model,
 552                                    const char *name,
 553                                    const char *host_str,
 554                                    Error **errp)
 555 {
 556     NetSocketState *s;
 557     int fd, connected, ret;
 558     struct sockaddr_in saddr;
 559
 560     if (parse_host_port(&saddr, host_str, errp) < 0) {
 561         return -1;
 562     }
 563
 564     fd = qemu_socket(PF_INET, SOCK_STREAM, 0);
 565     if (fd < 0) {
 566         error_setg_errno(errp, errno, "can't create stream socket");
 567         return -1;
 568     }
 569     qemu_socket_set_nonblock(fd);
 570
 571     connected = 0;
 572     for(;;) {
 573         ret = connect(fd, (struct sockaddr *)&saddr, sizeof(saddr));
 574         if (ret < 0) {
 575             if (errno == EINTR || errno == EWOULDBLOCK) {
 576                 /* continue */
 577             } else if (errno == EINPROGRESS ||
 578                        errno == EALREADY) {
 579                 break;
 580             } else {
 581                 error_setg_errno(errp, errno, "can't connect socket");
 582                 close(fd);
 583                 return -1;
 584             }
 585         } else {
 586             connected = 1;
 587             break;
 588         }
 589     }
 590     s = net_socket_fd_init(peer, model, name, fd, connected, NULL, errp);
 591     if (!s) {
 592         return -1;
 593     }
 594
 595     qemu_set_info_str(&s->nc, "socket: connect to %s:%d",
 596                       inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
 597     return 0;
 598 }
 599
 600 static int net_socket_mcast_init(NetClientState *peer,
 601                                  const char *model,
 602                                  const char *name,
 603                                  const char *host_str,
 604                                  const char *localaddr_str,
 605                                  Error **errp)
 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, errp) < 0) {
 613         return -1;
 614     }
 615
 616     if (localaddr_str != NULL) {
 617         if (inet_aton(localaddr_str, &localaddr) == 0) {
 618             error_setg(errp, "localaddr '%s' is not a valid IPv4 address",
 619                        localaddr_str);
 620             return -1;
 621         }
 622         param_localaddr = &localaddr;
 623     } else {
 624         param_localaddr = NULL;
 625     }
 626
 627     fd = net_socket_mcast_create(&saddr, param_localaddr, errp);
 628     if (fd < 0) {
 629         return -1;
 630     }
 631
 632     s = net_socket_fd_init(peer, model, name, fd, 0, NULL, errp);
 633     if (!s) {
 634         return -1;
 635     }
 636
 637     s->dgram_dst = saddr;
 638
 639     qemu_set_info_str(&s->nc, "socket: mcast=%s:%d",
 640                       inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
 641     return 0;
 642
 643 }
 644
 645 static int net_socket_udp_init(NetClientState *peer,
 646                                  const char *model,
 647                                  const char *name,
 648                                  const char *rhost,
 649                                  const char *lhost,
 650                                  Error **errp)
 651 {
 652     NetSocketState *s;
 653     int fd, ret;
 654     struct sockaddr_in laddr, raddr;
 655
 656     if (parse_host_port(&laddr, lhost, errp) < 0) {
 657         return -1;
 658     }
 659
 660     if (parse_host_port(&raddr, rhost, errp) < 0) {
 661         return -1;
 662     }
 663
 664     fd = qemu_socket(PF_INET, SOCK_DGRAM, 0);
 665     if (fd < 0) {
 666         error_setg_errno(errp, errno, "can't create datagram socket");
 667         return -1;
 668     }
 669
 670     ret = socket_set_fast_reuse(fd);
 671     if (ret < 0) {
 672         error_setg_errno(errp, errno,
 673                          "can't set socket option SO_REUSEADDR");
 674         close(fd);
 675         return -1;
 676     }
 677     ret = bind(fd, (struct sockaddr *)&laddr, sizeof(laddr));
 678     if (ret < 0) {
 679         error_setg_errno(errp, errno, "can't bind ip=%s to socket",
 680                          inet_ntoa(laddr.sin_addr));
 681         close(fd);
 682         return -1;
 683     }
 684     qemu_socket_set_nonblock(fd);
 685
 686     s = net_socket_fd_init(peer, model, name, fd, 0, NULL, errp);
 687     if (!s) {
 688         return -1;
 689     }
 690
 691     s->dgram_dst = raddr;
 692
 693     qemu_set_info_str(&s->nc, "socket: udp=%s:%d", inet_ntoa(raddr.sin_addr),
 694                       ntohs(raddr.sin_port));
 695     return 0;
 696 }
 697
 698 int net_init_socket(const Netdev *netdev, const char *name,
 699                     NetClientState *peer, Error **errp)
 700 {
 701     const NetdevSocketOptions *sock;
 702
 703     assert(netdev->type == NET_CLIENT_DRIVER_SOCKET);
 704     sock = &netdev->u.socket;
 705
 706     if (!!sock->fd + !!sock->listen + !!sock->connect + !!sock->mcast +
 707         !!sock->udp != 1) {
 708         error_setg(errp, "exactly one of listen=, connect=, mcast= or udp="
 709                    " is required");
 710         return -1;
 711     }
 712
 713     if (sock->localaddr && !sock->mcast && !sock->udp) {
 714         error_setg(errp, "localaddr= is only valid with mcast= or udp=");
 715         return -1;
 716     }
 717
 718     if (sock->fd) {
 719         int fd, ret;
 720
 721         fd = monitor_fd_param(monitor_cur(), sock->fd, errp);
 722         if (fd == -1) {
 723             return -1;
 724         }
 725         ret = qemu_socket_try_set_nonblock(fd);
 726         if (ret < 0) {
 727             error_setg_errno(errp, -ret, "%s: Can't use file descriptor %d",
 728                              name, fd);
 729             return -1;
 730         }
 731         if (!net_socket_fd_init(peer, "socket", name, fd, 1, sock->mcast,
 732                                 errp)) {
 733             return -1;
 734         }
 735         return 0;
 736     }
 737
 738     if (sock->listen) {
 739         if (net_socket_listen_init(peer, "socket", name, sock->listen, errp)
 740             < 0) {
 741             return -1;
 742         }
 743         return 0;
 744     }
 745
 746     if (sock->connect) {
 747         if (net_socket_connect_init(peer, "socket", name, sock->connect, errp)
 748             < 0) {
 749             return -1;
 750         }
 751         return 0;
 752     }
 753
 754     if (sock->mcast) {
 755         /* if sock->localaddr is missing, it has been initialized to "all bits
 756          * zero" */
 757         if (net_socket_mcast_init(peer, "socket", name, sock->mcast,
 758                                   sock->localaddr, errp) < 0) {
 759             return -1;
 760         }
 761         return 0;
 762     }
 763
 764     assert(sock->udp);
 765     if (!sock->localaddr) {
 766         error_setg(errp, "localaddr= is mandatory with udp=");
 767         return -1;
 768     }
 769     if (net_socket_udp_init(peer, "socket", name, sock->udp, sock->localaddr,
 770                             errp) < 0) {
 771         return -1;
 772     }
 773     return 0;
 774 }