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-common.h"
  31 #include "qemu/error-report.h"
  32 #include "qemu/option.h"
  33 #include "qemu/sockets.h"
  34 #include "qemu/iov.h"
  35 #include "qemu/main-loop.h"
  36
  37 typedef struct NetSocketState {
  38     NetClientState nc;
  39     int listen_fd;
  40     int fd;
  41     int state; /* 0 = getting length, 1 = getting data */
  42     unsigned int index;
  43     unsigned int packet_len;
  44     unsigned int send_index;      /* number of bytes sent (only SOCK_STREAM) */
  45     uint8_t buf[NET_BUFSIZE];
  46     struct sockaddr_in dgram_dst; /* contains inet host and port destination iff connectionless (SOCK_DGRAM) */
  47     IOHandler *send_fn;           /* differs between SOCK_STREAM/SOCK_DGRAM */
  48     bool read_poll;               /* waiting to receive data? */
  49     bool write_poll;              /* waiting to transmit data? */
  50 } NetSocketState;
  51
  52 static void net_socket_accept(void *opaque);
  53 static void net_socket_writable(void *opaque);
  54
  55 static void net_socket_update_fd_handler(NetSocketState *s)
  56 {
  57     qemu_set_fd_handler(s->fd,
  58                         s->read_poll ? s->send_fn : NULL,
  59                         s->write_poll ? net_socket_writable : NULL,
  60                         s);
  61 }
  62
  63 static void net_socket_read_poll(NetSocketState *s, bool enable)
  64 {
  65     s->read_poll = enable;
  66     net_socket_update_fd_handler(s);
  67 }
  68
  69 static void net_socket_write_poll(NetSocketState *s, bool enable)
  70 {
  71     s->write_poll = enable;
  72     net_socket_update_fd_handler(s);
  73 }
  74
  75 static void net_socket_writable(void *opaque)
  76 {
  77     NetSocketState *s = opaque;
  78
  79     net_socket_write_poll(s, false);
  80
  81     qemu_flush_queued_packets(&s->nc);
  82 }
  83
  84 static ssize_t net_socket_receive(NetClientState *nc, const uint8_t *buf, size_t size)
  85 {
  86     NetSocketState *s = DO_UPCAST(NetSocketState, nc, nc);
  87     uint32_t len = htonl(size);
  88     struct iovec iov[] = {
  89         {
  90             .iov_base = &len,
  91             .iov_len  = sizeof(len),
  92         }, {
  93             .iov_base = (void *)buf,
  94             .iov_len  = size,
  95         },
  96     };
  97     size_t remaining;
  98     ssize_t ret;
  99
 100     remaining = iov_size(iov, 2) - s->send_index;
 101     ret = iov_send(s->fd, iov, 2, s->send_index, remaining);
 102
 103     if (ret == -1 && errno == EAGAIN) {
 104         ret = 0; /* handled further down */
 105     }
 106     if (ret == -1) {
 107         s->send_index = 0;
 108         return -errno;
 109     }
 110     if (ret < (ssize_t)remaining) {
 111         s->send_index += ret;
 112         net_socket_write_poll(s, true);
 113         return 0;
 114     }
 115     s->send_index = 0;
 116     return size;
 117 }
 118
 119 static ssize_t net_socket_receive_dgram(NetClientState *nc, const uint8_t *buf, size_t size)
 120 {
 121     NetSocketState *s = DO_UPCAST(NetSocketState, nc, nc);
 122     ssize_t ret;
 123
 124     do {
 125         ret = qemu_sendto(s->fd, buf, size, 0,
 126                           (struct sockaddr *)&s->dgram_dst,
 127                           sizeof(s->dgram_dst));
 128     } while (ret == -1 && errno == EINTR);
 129
 130     if (ret == -1 && errno == EAGAIN) {
 131         net_socket_write_poll(s, true);
 132         return 0;
 133     }
 134     return ret;
 135 }
 136
 137 static void net_socket_send_completed(NetClientState *nc, ssize_t len)
 138 {
 139     NetSocketState *s = DO_UPCAST(NetSocketState, nc, nc);
 140
 141     if (!s->read_poll) {
 142         net_socket_read_poll(s, true);
 143     }
 144 }
 145
 146 static void net_socket_send(void *opaque)
 147 {
 148     NetSocketState *s = opaque;
 149     int size;
 150     unsigned l;
 151     uint8_t buf1[NET_BUFSIZE];
 152     const uint8_t *buf;
 153
 154     size = qemu_recv(s->fd, buf1, sizeof(buf1), 0);
 155     if (size < 0) {
 156         if (errno != EWOULDBLOCK)
 157             goto eoc;
 158     } else if (size == 0) {
 159         /* end of connection */
 160     eoc:
 161         net_socket_read_poll(s, false);
 162         net_socket_write_poll(s, false);
 163         if (s->listen_fd != -1) {
 164             qemu_set_fd_handler(s->listen_fd, net_socket_accept, NULL, s);
 165         }
 166         closesocket(s->fd);
 167
 168         s->fd = -1;
 169         s->state = 0;
 170         s->index = 0;
 171         s->packet_len = 0;
 172         s->nc.link_down = true;
 173         memset(s->buf, 0, sizeof(s->buf));
 174         memset(s->nc.info_str, 0, sizeof(s->nc.info_str));
 175
 176         return;
 177     }
 178     buf = buf1;
 179     while (size > 0) {
 180         /* reassemble a packet from the network */
 181         switch(s->state) {
 182         case 0:
 183             l = 4 - s->index;
 184             if (l > size)
 185                 l = size;
 186             memcpy(s->buf + s->index, buf, l);
 187             buf += l;
 188             size -= l;
 189             s->index += l;
 190             if (s->index == 4) {
 191                 /* got length */
 192                 s->packet_len = ntohl(*(uint32_t *)s->buf);
 193                 s->index = 0;
 194                 s->state = 1;
 195             }
 196             break;
 197         case 1:
 198             l = s->packet_len - s->index;
 199             if (l > size)
 200                 l = size;
 201             if (s->index + l <= sizeof(s->buf)) {
 202                 memcpy(s->buf + s->index, buf, l);
 203             } else {
 204                 fprintf(stderr, "serious error: oversized packet received,"
 205                     "connection terminated.\n");
 206                 s->state = 0;
 207                 goto eoc;
 208             }
 209
 210             s->index += l;
 211             buf += l;
 212             size -= l;
 213             if (s->index >= s->packet_len) {
 214                 s->index = 0;
 215                 s->state = 0;
 216                 if (qemu_send_packet_async(&s->nc, s->buf, s->packet_len,
 217                                            net_socket_send_completed) == 0) {
 218                     net_socket_read_poll(s, false);
 219                     break;
 220                 }
 221             }
 222             break;
 223         }
 224     }
 225 }
 226
 227 static void net_socket_send_dgram(void *opaque)
 228 {
 229     NetSocketState *s = opaque;
 230     int size;
 231
 232     size = qemu_recv(s->fd, s->buf, sizeof(s->buf), 0);
 233     if (size < 0)
 234         return;
 235     if (size == 0) {
 236         /* end of connection */
 237         net_socket_read_poll(s, false);
 238         net_socket_write_poll(s, false);
 239         return;
 240     }
 241     if (qemu_send_packet_async(&s->nc, s->buf, size,
 242                                net_socket_send_completed) == 0) {
 243         net_socket_read_poll(s, false);
 244     }
 245 }
 246
 247 static int net_socket_mcast_create(struct sockaddr_in *mcastaddr, struct in_addr *localaddr)
 248 {
 249     struct ip_mreq imr;
 250     int fd;
 251     int val, ret;
 252 #ifdef __OpenBSD__
 253     unsigned char loop;
 254 #else
 255     int loop;
 256 #endif
 257
 258     if (!IN_MULTICAST(ntohl(mcastaddr->sin_addr.s_addr))) {
 259         fprintf(stderr, "qemu: error: specified mcastaddr \"%s\" (0x%08x) "
 260                 "does not contain a multicast address\n",
 261                 inet_ntoa(mcastaddr->sin_addr),
 262                 (int)ntohl(mcastaddr->sin_addr.s_addr));
 263         return -1;
 264
 265     }
 266     fd = qemu_socket(PF_INET, SOCK_DGRAM, 0);
 267     if (fd < 0) {
 268         perror("socket(PF_INET, SOCK_DGRAM)");
 269         return -1;
 270     }
 271
 272     /* Allow multiple sockets to bind the same multicast ip and port by setting
 273      * SO_REUSEADDR. This is the only situation where SO_REUSEADDR should be set
 274      * on windows. Use socket_set_fast_reuse otherwise as it sets SO_REUSEADDR
 275      * only on posix systems.
 276      */
 277     val = 1;
 278     ret = qemu_setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
 279     if (ret < 0) {
 280         perror("setsockopt(SOL_SOCKET, SO_REUSEADDR)");
 281         goto fail;
 282     }
 283
 284     ret = bind(fd, (struct sockaddr *)mcastaddr, sizeof(*mcastaddr));
 285     if (ret < 0) {
 286         perror("bind");
 287         goto fail;
 288     }
 289
 290     /* Add host to multicast group */
 291     imr.imr_multiaddr = mcastaddr->sin_addr;
 292     if (localaddr) {
 293         imr.imr_interface = *localaddr;
 294     } else {
 295         imr.imr_interface.s_addr = htonl(INADDR_ANY);
 296     }
 297
 298     ret = qemu_setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
 299                           &imr, sizeof(struct ip_mreq));
 300     if (ret < 0) {
 301         perror("setsockopt(IP_ADD_MEMBERSHIP)");
 302         goto fail;
 303     }
 304
 305     /* Force mcast msgs to loopback (eg. several QEMUs in same host */
 306     loop = 1;
 307     ret = qemu_setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP,
 308                           &loop, sizeof(loop));
 309     if (ret < 0) {
 310         perror("setsockopt(SOL_IP, IP_MULTICAST_LOOP)");
 311         goto fail;
 312     }
 313
 314     /* If a bind address is given, only send packets from that address */
 315     if (localaddr != NULL) {
 316         ret = qemu_setsockopt(fd, IPPROTO_IP, IP_MULTICAST_IF,
 317                               localaddr, sizeof(*localaddr));
 318         if (ret < 0) {
 319             perror("setsockopt(IP_MULTICAST_IF)");
 320             goto fail;
 321         }
 322     }
 323
 324     qemu_set_nonblock(fd);
 325     return fd;
 326 fail:
 327     if (fd >= 0)
 328         closesocket(fd);
 329     return -1;
 330 }
 331
 332 static void net_socket_cleanup(NetClientState *nc)
 333 {
 334     NetSocketState *s = DO_UPCAST(NetSocketState, nc, nc);
 335     if (s->fd != -1) {
 336         net_socket_read_poll(s, false);
 337         net_socket_write_poll(s, false);
 338         close(s->fd);
 339         s->fd = -1;
 340     }
 341     if (s->listen_fd != -1) {
 342         qemu_set_fd_handler(s->listen_fd, NULL, NULL, NULL);
 343         closesocket(s->listen_fd);
 344         s->listen_fd = -1;
 345     }
 346 }
 347
 348 static NetClientInfo net_dgram_socket_info = {
 349     .type = NET_CLIENT_OPTIONS_KIND_SOCKET,
 350     .size = sizeof(NetSocketState),
 351     .receive = net_socket_receive_dgram,
 352     .cleanup = net_socket_cleanup,
 353 };
 354
 355 static NetSocketState *net_socket_fd_init_dgram(NetClientState *peer,
 356                                                 const char *model,
 357                                                 const char *name,
 358                                                 int fd, int is_connected)
 359 {
 360     struct sockaddr_in saddr;
 361     int newfd;
 362     socklen_t saddr_len = sizeof(saddr);
 363     NetClientState *nc;
 364     NetSocketState *s;
 365
 366     /* fd passed: multicast: "learn" dgram_dst address from bound address and save it
 367      * Because this may be "shared" socket from a "master" process, datagrams would be recv()
 368      * by ONLY ONE process: we must "clone" this dgram socket --jjo
 369      */
 370
 371     if (is_connected) {
 372         if (getsockname(fd, (struct sockaddr *) &saddr, &saddr_len) == 0) {
 373             /* must be bound */
 374             if (saddr.sin_addr.s_addr == 0) {
 375                 fprintf(stderr, "qemu: error: init_dgram: fd=%d unbound, "
 376                         "cannot setup multicast dst addr\n", fd);
 377                 goto err;
 378             }
 379             /* clone dgram socket */
 380             newfd = net_socket_mcast_create(&saddr, NULL);
 381             if (newfd < 0) {
 382                 /* error already reported by net_socket_mcast_create() */
 383                 goto err;
 384             }
 385             /* clone newfd to fd, close newfd */
 386             dup2(newfd, fd);
 387             close(newfd);
 388
 389         } else {
 390             fprintf(stderr,
 391                     "qemu: error: init_dgram: fd=%d failed getsockname(): %s\n",
 392                     fd, strerror(errno));
 393             goto err;
 394         }
 395     }
 396
 397     nc = qemu_new_net_client(&net_dgram_socket_info, peer, model, name);
 398
 399     s = DO_UPCAST(NetSocketState, nc, nc);
 400
 401     s->fd = fd;
 402     s->listen_fd = -1;
 403     s->send_fn = net_socket_send_dgram;
 404     net_socket_read_poll(s, true);
 405
 406     /* mcast: save bound address as dst */
 407     if (is_connected) {
 408         s->dgram_dst = saddr;
 409         snprintf(nc->info_str, sizeof(nc->info_str),
 410                  "socket: fd=%d (cloned mcast=%s:%d)",
 411                  fd, inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
 412     } else {
 413         snprintf(nc->info_str, sizeof(nc->info_str),
 414                  "socket: fd=%d", fd);
 415     }
 416
 417     return s;
 418
 419 err:
 420     closesocket(fd);
 421     return NULL;
 422 }
 423
 424 static void net_socket_connect(void *opaque)
 425 {
 426     NetSocketState *s = opaque;
 427     s->send_fn = net_socket_send;
 428     net_socket_read_poll(s, true);
 429 }
 430
 431 static NetClientInfo net_socket_info = {
 432     .type = NET_CLIENT_OPTIONS_KIND_SOCKET,
 433     .size = sizeof(NetSocketState),
 434     .receive = net_socket_receive,
 435     .cleanup = net_socket_cleanup,
 436 };
 437
 438 static NetSocketState *net_socket_fd_init_stream(NetClientState *peer,
 439                                                  const char *model,
 440                                                  const char *name,
 441                                                  int fd, int is_connected)
 442 {
 443     NetClientState *nc;
 444     NetSocketState *s;
 445
 446     nc = qemu_new_net_client(&net_socket_info, peer, model, name);
 447
 448     snprintf(nc->info_str, sizeof(nc->info_str), "socket: fd=%d", fd);
 449
 450     s = DO_UPCAST(NetSocketState, nc, nc);
 451
 452     s->fd = fd;
 453     s->listen_fd = -1;
 454
 455     /* Disable Nagle algorithm on TCP sockets to reduce latency */
 456     socket_set_nodelay(fd);
 457
 458     if (is_connected) {
 459         net_socket_connect(s);
 460     } else {
 461         qemu_set_fd_handler(s->fd, NULL, net_socket_connect, s);
 462     }
 463     return s;
 464 }
 465
 466 static NetSocketState *net_socket_fd_init(NetClientState *peer,
 467                                           const char *model, const char *name,
 468                                           int fd, int is_connected)
 469 {
 470     int so_type = -1, optlen=sizeof(so_type);
 471
 472     if(getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&so_type,
 473         (socklen_t *)&optlen)< 0) {
 474         fprintf(stderr, "qemu: error: getsockopt(SO_TYPE) for fd=%d failed\n",
 475                 fd);
 476         closesocket(fd);
 477         return NULL;
 478     }
 479     switch(so_type) {
 480     case SOCK_DGRAM:
 481         return net_socket_fd_init_dgram(peer, model, name, fd, is_connected);
 482     case SOCK_STREAM:
 483         return net_socket_fd_init_stream(peer, model, name, fd, is_connected);
 484     default:
 485         /* who knows ... this could be a eg. a pty, do warn and continue as stream */
 486         fprintf(stderr, "qemu: warning: socket type=%d for fd=%d is not SOCK_DGRAM or SOCK_STREAM\n", so_type, fd);
 487         return net_socket_fd_init_stream(peer, model, name, fd, is_connected);
 488     }
 489     return NULL;
 490 }
 491
 492 static void net_socket_accept(void *opaque)
 493 {
 494     NetSocketState *s = opaque;
 495     struct sockaddr_in saddr;
 496     socklen_t len;
 497     int fd;
 498
 499     for(;;) {
 500         len = sizeof(saddr);
 501         fd = qemu_accept(s->listen_fd, (struct sockaddr *)&saddr, &len);
 502         if (fd < 0 && errno != EINTR) {
 503             return;
 504         } else if (fd >= 0) {
 505             qemu_set_fd_handler(s->listen_fd, NULL, NULL, NULL);
 506             break;
 507         }
 508     }
 509
 510     s->fd = fd;
 511     s->nc.link_down = false;
 512     net_socket_connect(s);
 513     snprintf(s->nc.info_str, sizeof(s->nc.info_str),
 514              "socket: connection from %s:%d",
 515              inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
 516 }
 517
 518 static int net_socket_listen_init(NetClientState *peer,
 519                                   const char *model,
 520                                   const char *name,
 521                                   const char *host_str)
 522 {
 523     NetClientState *nc;
 524     NetSocketState *s;
 525     struct sockaddr_in saddr;
 526     int fd, ret;
 527
 528     if (parse_host_port(&saddr, host_str) < 0)
 529         return -1;
 530
 531     fd = qemu_socket(PF_INET, SOCK_STREAM, 0);
 532     if (fd < 0) {
 533         perror("socket");
 534         return -1;
 535     }
 536     qemu_set_nonblock(fd);
 537
 538     socket_set_fast_reuse(fd);
 539
 540     ret = bind(fd, (struct sockaddr *)&saddr, sizeof(saddr));
 541     if (ret < 0) {
 542         perror("bind");
 543         closesocket(fd);
 544         return -1;
 545     }
 546     ret = listen(fd, 0);
 547     if (ret < 0) {
 548         perror("listen");
 549         closesocket(fd);
 550         return -1;
 551     }
 552
 553     nc = qemu_new_net_client(&net_socket_info, peer, model, name);
 554     s = DO_UPCAST(NetSocketState, nc, nc);
 555     s->fd = -1;
 556     s->listen_fd = fd;
 557     s->nc.link_down = true;
 558
 559     qemu_set_fd_handler(s->listen_fd, net_socket_accept, NULL, s);
 560     return 0;
 561 }
 562
 563 static int net_socket_connect_init(NetClientState *peer,
 564                                    const char *model,
 565                                    const char *name,
 566                                    const char *host_str)
 567 {
 568     NetSocketState *s;
 569     int fd, connected, ret;
 570     struct sockaddr_in saddr;
 571
 572     if (parse_host_port(&saddr, host_str) < 0)
 573         return -1;
 574
 575     fd = qemu_socket(PF_INET, SOCK_STREAM, 0);
 576     if (fd < 0) {
 577         perror("socket");
 578         return -1;
 579     }
 580     qemu_set_nonblock(fd);
 581
 582     connected = 0;
 583     for(;;) {
 584         ret = connect(fd, (struct sockaddr *)&saddr, sizeof(saddr));
 585         if (ret < 0) {
 586             if (errno == EINTR || errno == EWOULDBLOCK) {
 587                 /* continue */
 588             } else if (errno == EINPROGRESS ||
 589                        errno == EALREADY ||
 590                        errno == EINVAL) {
 591                 break;
 592             } else {
 593                 perror("connect");
 594                 closesocket(fd);
 595                 return -1;
 596             }
 597         } else {
 598             connected = 1;
 599             break;
 600         }
 601     }
 602     s = net_socket_fd_init(peer, model, name, fd, connected);
 603     if (!s)
 604         return -1;
 605     snprintf(s->nc.info_str, sizeof(s->nc.info_str),
 606              "socket: connect to %s:%d",
 607              inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
 608     return 0;
 609 }
 610
 611 static int net_socket_mcast_init(NetClientState *peer,
 612                                  const char *model,
 613                                  const char *name,
 614                                  const char *host_str,
 615                                  const char *localaddr_str)
 616 {
 617     NetSocketState *s;
 618     int fd;
 619     struct sockaddr_in saddr;
 620     struct in_addr localaddr, *param_localaddr;
 621
 622     if (parse_host_port(&saddr, host_str) < 0)
 623         return -1;
 624
 625     if (localaddr_str != NULL) {
 626         if (inet_aton(localaddr_str, &localaddr) == 0)
 627             return -1;
 628         param_localaddr = &localaddr;
 629     } else {
 630         param_localaddr = NULL;
 631     }
 632
 633     fd = net_socket_mcast_create(&saddr, param_localaddr);
 634     if (fd < 0)
 635         return -1;
 636
 637     s = net_socket_fd_init(peer, model, name, fd, 0);
 638     if (!s)
 639         return -1;
 640
 641     s->dgram_dst = saddr;
 642
 643     snprintf(s->nc.info_str, sizeof(s->nc.info_str),
 644              "socket: mcast=%s:%d",
 645              inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
 646     return 0;
 647
 648 }
 649
 650 static int net_socket_udp_init(NetClientState *peer,
 651                                  const char *model,
 652                                  const char *name,
 653                                  const char *rhost,
 654                                  const char *lhost)
 655 {
 656     NetSocketState *s;
 657     int fd, ret;
 658     struct sockaddr_in laddr, raddr;
 659
 660     if (parse_host_port(&laddr, lhost) < 0) {
 661         return -1;
 662     }
 663
 664     if (parse_host_port(&raddr, rhost) < 0) {
 665         return -1;
 666     }
 667
 668     fd = qemu_socket(PF_INET, SOCK_DGRAM, 0);
 669     if (fd < 0) {
 670         perror("socket(PF_INET, SOCK_DGRAM)");
 671         return -1;
 672     }
 673
 674     ret = socket_set_fast_reuse(fd);
 675     if (ret < 0) {
 676         closesocket(fd);
 677         return -1;
 678     }
 679     ret = bind(fd, (struct sockaddr *)&laddr, sizeof(laddr));
 680     if (ret < 0) {
 681         perror("bind");
 682         closesocket(fd);
 683         return -1;
 684     }
 685     qemu_set_nonblock(fd);
 686
 687     s = net_socket_fd_init(peer, model, name, fd, 0);
 688     if (!s) {
 689         return -1;
 690     }
 691
 692     s->dgram_dst = raddr;
 693
 694     snprintf(s->nc.info_str, sizeof(s->nc.info_str),
 695              "socket: udp=%s:%d",
 696              inet_ntoa(raddr.sin_addr), ntohs(raddr.sin_port));
 697     return 0;
 698 }
 699
 700 int net_init_socket(const NetClientOptions *opts, const char *name,
 701                     NetClientState *peer, Error **errp)
 702 {
 703     /* FIXME error_setg(errp, ...) on failure */
 704     Error *err = NULL;
 705     const NetdevSocketOptions *sock;
 706
 707     assert(opts->type == NET_CLIENT_OPTIONS_KIND_SOCKET);
 708     sock = opts->u.socket.data;
 709
 710     if (sock->has_fd + sock->has_listen + sock->has_connect + sock->has_mcast +
 711         sock->has_udp != 1) {
 712         error_report("exactly one of fd=, listen=, connect=, mcast= or udp="
 713                      " is required");
 714         return -1;
 715     }
 716
 717     if (sock->has_localaddr && !sock->has_mcast && !sock->has_udp) {
 718         error_report("localaddr= is only valid with mcast= or udp=");
 719         return -1;
 720     }
 721
 722     if (sock->has_fd) {
 723         int fd;
 724
 725         fd = monitor_fd_param(cur_mon, sock->fd, &err);
 726         if (fd == -1) {
 727             error_report_err(err);
 728             return -1;
 729         }
 730         qemu_set_nonblock(fd);
 731         if (!net_socket_fd_init(peer, "socket", name, fd, 1)) {
 732             return -1;
 733         }
 734         return 0;
 735     }
 736
 737     if (sock->has_listen) {
 738         if (net_socket_listen_init(peer, "socket", name, sock->listen) == -1) {
 739             return -1;
 740         }
 741         return 0;
 742     }
 743
 744     if (sock->has_connect) {
 745         if (net_socket_connect_init(peer, "socket", name, sock->connect) ==
 746             -1) {
 747             return -1;
 748         }
 749         return 0;
 750     }
 751
 752     if (sock->has_mcast) {
 753         /* if sock->localaddr is missing, it has been initialized to "all bits
 754          * zero" */
 755         if (net_socket_mcast_init(peer, "socket", name, sock->mcast,
 756             sock->localaddr) == -1) {
 757             return -1;
 758         }
 759         return 0;
 760     }
 761
 762     assert(sock->has_udp);
 763     if (!sock->has_localaddr) {
 764         error_report("localaddr= is mandatory with udp=");
 765         return -1;
 766     }
 767     if (net_socket_udp_init(peer, "socket", name, sock->udp, sock->localaddr) ==
 768         -1) {
 769         return -1;
 770     }
 771     return 0;
 772 }