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