qemu/net/socket.c
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   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
  37typedef struct NetSocketState {
  38    NetClientState nc;
  39    int listen_fd;
  40    int fd;
  41    SocketReadState rs;
  42    unsigned int send_index;      /* number of bytes sent (only SOCK_STREAM) */
  43    struct sockaddr_in dgram_dst; /* contains inet host and port destination iff connectionless (SOCK_DGRAM) */
  44    IOHandler *send_fn;           /* differs between SOCK_STREAM/SOCK_DGRAM */
  45    bool read_poll;               /* waiting to receive data? */
  46    bool write_poll;              /* waiting to transmit data? */
  47} NetSocketState;
  48
  49static void net_socket_accept(void *opaque);
  50static void net_socket_writable(void *opaque);
  51
  52static void net_socket_update_fd_handler(NetSocketState *s)
  53{
  54    qemu_set_fd_handler(s->fd,
  55                        s->read_poll ? s->send_fn : NULL,
  56                        s->write_poll ? net_socket_writable : NULL,
  57                        s);
  58}
  59
  60static void net_socket_read_poll(NetSocketState *s, bool enable)
  61{
  62    s->read_poll = enable;
  63    net_socket_update_fd_handler(s);
  64}
  65
  66static void net_socket_write_poll(NetSocketState *s, bool enable)
  67{
  68    s->write_poll = enable;
  69    net_socket_update_fd_handler(s);
  70}
  71
  72static void net_socket_writable(void *opaque)
  73{
  74    NetSocketState *s = opaque;
  75
  76    net_socket_write_poll(s, false);
  77
  78    qemu_flush_queued_packets(&s->nc);
  79}
  80
  81static ssize_t net_socket_receive(NetClientState *nc, const uint8_t *buf, size_t size)
  82{
  83    NetSocketState *s = DO_UPCAST(NetSocketState, nc, nc);
  84    uint32_t len = htonl(size);
  85    struct iovec iov[] = {
  86        {
  87            .iov_base = &len,
  88            .iov_len  = sizeof(len),
  89        }, {
  90            .iov_base = (void *)buf,
  91            .iov_len  = size,
  92        },
  93    };
  94    size_t remaining;
  95    ssize_t ret;
  96
  97    remaining = iov_size(iov, 2) - s->send_index;
  98    ret = iov_send(s->fd, iov, 2, s->send_index, remaining);
  99
 100    if (ret == -1 && errno == EAGAIN) {
 101        ret = 0; /* handled further down */
 102    }
 103    if (ret == -1) {
 104        s->send_index = 0;
 105        return -errno;
 106    }
 107    if (ret < (ssize_t)remaining) {
 108        s->send_index += ret;
 109        net_socket_write_poll(s, true);
 110        return 0;
 111    }
 112    s->send_index = 0;
 113    return size;
 114}
 115
 116static ssize_t net_socket_receive_dgram(NetClientState *nc, const uint8_t *buf, size_t size)
 117{
 118    NetSocketState *s = DO_UPCAST(NetSocketState, nc, nc);
 119    ssize_t ret;
 120
 121    do {
 122        ret = qemu_sendto(s->fd, buf, size, 0,
 123                          (struct sockaddr *)&s->dgram_dst,
 124                          sizeof(s->dgram_dst));
 125    } while (ret == -1 && errno == EINTR);
 126
 127    if (ret == -1 && errno == EAGAIN) {
 128        net_socket_write_poll(s, true);
 129        return 0;
 130    }
 131    return ret;
 132}
 133
 134static void net_socket_send_completed(NetClientState *nc, ssize_t len)
 135{
 136    NetSocketState *s = DO_UPCAST(NetSocketState, nc, nc);
 137
 138    if (!s->read_poll) {
 139        net_socket_read_poll(s, true);
 140    }
 141}
 142
 143static void net_socket_rs_finalize(SocketReadState *rs)
 144{
 145    NetSocketState *s = container_of(rs, NetSocketState, rs);
 146
 147    if (qemu_send_packet_async(&s->nc, rs->buf,
 148                               rs->packet_len,
 149                               net_socket_send_completed) == 0) {
 150        net_socket_read_poll(s, false);
 151    }
 152}
 153
 154static void net_socket_send(void *opaque)
 155{
 156    NetSocketState *s = opaque;
 157    int size;
 158    int ret;
 159    uint8_t buf1[NET_BUFSIZE];
 160    const uint8_t *buf;
 161
 162    size = qemu_recv(s->fd, buf1, sizeof(buf1), 0);
 163    if (size < 0) {
 164        if (errno != EWOULDBLOCK)
 165            goto eoc;
 166    } else if (size == 0) {
 167        /* end of connection */
 168    eoc:
 169        net_socket_read_poll(s, false);
 170        net_socket_write_poll(s, false);
 171        if (s->listen_fd != -1) {
 172            qemu_set_fd_handler(s->listen_fd, net_socket_accept, NULL, s);
 173        }
 174        closesocket(s->fd);
 175
 176        s->fd = -1;
 177        net_socket_rs_init(&s->rs, net_socket_rs_finalize, false);
 178        s->nc.link_down = true;
 179        memset(s->nc.info_str, 0, sizeof(s->nc.info_str));
 180
 181        return;
 182    }
 183    buf = buf1;
 184
 185    ret = net_fill_rstate(&s->rs, buf, size);
 186
 187    if (ret == -1) {
 188        goto eoc;
 189    }
 190}
 191
 192static void net_socket_send_dgram(void *opaque)
 193{
 194    NetSocketState *s = opaque;
 195    int size;
 196
 197    size = qemu_recv(s->fd, s->rs.buf, sizeof(s->rs.buf), 0);
 198    if (size < 0)
 199        return;
 200    if (size == 0) {
 201        /* end of connection */
 202        net_socket_read_poll(s, false);
 203        net_socket_write_poll(s, false);
 204        return;
 205    }
 206    if (qemu_send_packet_async(&s->nc, s->rs.buf, size,
 207                               net_socket_send_completed) == 0) {
 208        net_socket_read_poll(s, false);
 209    }
 210}
 211
 212static int net_socket_mcast_create(struct sockaddr_in *mcastaddr,
 213                                   struct in_addr *localaddr,
 214                                   Error **errp)
 215{
 216    struct ip_mreq imr;
 217    int fd;
 218    int val, ret;
 219#ifdef __OpenBSD__
 220    unsigned char loop;
 221#else
 222    int loop;
 223#endif
 224
 225    if (!IN_MULTICAST(ntohl(mcastaddr->sin_addr.s_addr))) {
 226        error_setg(errp, "specified mcastaddr %s (0x%08x) "
 227                   "does not contain a multicast address",
 228                   inet_ntoa(mcastaddr->sin_addr),
 229                   (int)ntohl(mcastaddr->sin_addr.s_addr));
 230        return -1;
 231    }
 232
 233    fd = qemu_socket(PF_INET, SOCK_DGRAM, 0);
 234    if (fd < 0) {
 235        error_setg_errno(errp, errno, "can't create datagram socket");
 236        return -1;
 237    }
 238
 239    /* Allow multiple sockets to bind the same multicast ip and port by setting
 240     * SO_REUSEADDR. This is the only situation where SO_REUSEADDR should be set
 241     * on windows. Use socket_set_fast_reuse otherwise as it sets SO_REUSEADDR
 242     * only on posix systems.
 243     */
 244    val = 1;
 245    ret = qemu_setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &val, sizeof(val));
 246    if (ret < 0) {
 247        error_setg_errno(errp, errno,
 248                         "can't set socket option SO_REUSEADDR");
 249        goto fail;
 250    }
 251
 252    ret = bind(fd, (struct sockaddr *)mcastaddr, sizeof(*mcastaddr));
 253    if (ret < 0) {
 254        error_setg_errno(errp, errno, "can't bind ip=%s to socket",
 255                         inet_ntoa(mcastaddr->sin_addr));
 256        goto fail;
 257    }
 258
 259    /* Add host to multicast group */
 260    imr.imr_multiaddr = mcastaddr->sin_addr;
 261    if (localaddr) {
 262        imr.imr_interface = *localaddr;
 263    } else {
 264        imr.imr_interface.s_addr = htonl(INADDR_ANY);
 265    }
 266
 267    ret = qemu_setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
 268                          &imr, sizeof(struct ip_mreq));
 269    if (ret < 0) {
 270        error_setg_errno(errp, errno,
 271                         "can't add socket to multicast group %s",
 272                         inet_ntoa(imr.imr_multiaddr));
 273        goto fail;
 274    }
 275
 276    /* Force mcast msgs to loopback (eg. several QEMUs in same host */
 277    loop = 1;
 278    ret = qemu_setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP,
 279                          &loop, sizeof(loop));
 280    if (ret < 0) {
 281        error_setg_errno(errp, errno,
 282                         "can't force multicast message to loopback");
 283        goto fail;
 284    }
 285
 286    /* If a bind address is given, only send packets from that address */
 287    if (localaddr != NULL) {
 288        ret = qemu_setsockopt(fd, IPPROTO_IP, IP_MULTICAST_IF,
 289                              localaddr, sizeof(*localaddr));
 290        if (ret < 0) {
 291            error_setg_errno(errp, errno,
 292                             "can't set the default network send interface");
 293            goto fail;
 294        }
 295    }
 296
 297    qemu_set_nonblock(fd);
 298    return fd;
 299fail:
 300    if (fd >= 0)
 301        closesocket(fd);
 302    return -1;
 303}
 304
 305static void net_socket_cleanup(NetClientState *nc)
 306{
 307    NetSocketState *s = DO_UPCAST(NetSocketState, nc, nc);
 308    if (s->fd != -1) {
 309        net_socket_read_poll(s, false);
 310        net_socket_write_poll(s, false);
 311        close(s->fd);
 312        s->fd = -1;
 313    }
 314    if (s->listen_fd != -1) {
 315        qemu_set_fd_handler(s->listen_fd, NULL, NULL, NULL);
 316        closesocket(s->listen_fd);
 317        s->listen_fd = -1;
 318    }
 319}
 320
 321static NetClientInfo net_dgram_socket_info = {
 322    .type = NET_CLIENT_DRIVER_SOCKET,
 323    .size = sizeof(NetSocketState),
 324    .receive = net_socket_receive_dgram,
 325    .cleanup = net_socket_cleanup,
 326};
 327
 328static NetSocketState *net_socket_fd_init_dgram(NetClientState *peer,
 329                                                const char *model,
 330                                                const char *name,
 331                                                int fd, int is_connected,
 332                                                const char *mcast,
 333                                                Error **errp)
 334{
 335    struct sockaddr_in saddr;
 336    int newfd;
 337    NetClientState *nc;
 338    NetSocketState *s;
 339
 340    /* fd passed: multicast: "learn" dgram_dst address from bound address and save it
 341     * Because this may be "shared" socket from a "master" process, datagrams would be recv()
 342     * by ONLY ONE process: we must "clone" this dgram socket --jjo
 343     */
 344
 345    if (is_connected && mcast != NULL) {
 346            if (parse_host_port(&saddr, mcast, errp) < 0) {
 347                goto err;
 348            }
 349            /* must be bound */
 350            if (saddr.sin_addr.s_addr == 0) {
 351                error_setg(errp, "can't setup multicast destination address");
 352                goto err;
 353            }
 354            /* clone dgram socket */
 355            newfd = net_socket_mcast_create(&saddr, NULL, errp);
 356            if (newfd < 0) {
 357                goto err;
 358            }
 359            /* clone newfd to fd, close newfd */
 360            dup2(newfd, fd);
 361            close(newfd);
 362
 363    }
 364
 365    nc = qemu_new_net_client(&net_dgram_socket_info, peer, model, name);
 366
 367    s = DO_UPCAST(NetSocketState, nc, nc);
 368
 369    s->fd = fd;
 370    s->listen_fd = -1;
 371    s->send_fn = net_socket_send_dgram;
 372    net_socket_rs_init(&s->rs, net_socket_rs_finalize, false);
 373    net_socket_read_poll(s, true);
 374
 375    /* mcast: save bound address as dst */
 376    if (is_connected && mcast != NULL) {
 377        s->dgram_dst = saddr;
 378        snprintf(nc->info_str, sizeof(nc->info_str),
 379                 "socket: fd=%d (cloned mcast=%s:%d)",
 380                 fd, inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
 381    } else {
 382        snprintf(nc->info_str, sizeof(nc->info_str),
 383                 "socket: fd=%d", fd);
 384    }
 385
 386    return s;
 387
 388err:
 389    closesocket(fd);
 390    return NULL;
 391}
 392
 393static void net_socket_connect(void *opaque)
 394{
 395    NetSocketState *s = opaque;
 396    s->send_fn = net_socket_send;
 397    net_socket_read_poll(s, true);
 398}
 399
 400static NetClientInfo net_socket_info = {
 401    .type = NET_CLIENT_DRIVER_SOCKET,
 402    .size = sizeof(NetSocketState),
 403    .receive = net_socket_receive,
 404    .cleanup = net_socket_cleanup,
 405};
 406
 407static NetSocketState *net_socket_fd_init_stream(NetClientState *peer,
 408                                                 const char *model,
 409                                                 const char *name,
 410                                                 int fd, int is_connected)
 411{
 412    NetClientState *nc;
 413    NetSocketState *s;
 414
 415    nc = qemu_new_net_client(&net_socket_info, peer, model, name);
 416
 417    snprintf(nc->info_str, sizeof(nc->info_str), "socket: fd=%d", fd);
 418
 419    s = DO_UPCAST(NetSocketState, nc, nc);
 420
 421    s->fd = fd;
 422    s->listen_fd = -1;
 423    net_socket_rs_init(&s->rs, net_socket_rs_finalize, false);
 424
 425    /* Disable Nagle algorithm on TCP sockets to reduce latency */
 426    socket_set_nodelay(fd);
 427
 428    if (is_connected) {
 429        net_socket_connect(s);
 430    } else {
 431        qemu_set_fd_handler(s->fd, NULL, net_socket_connect, s);
 432    }
 433    return s;
 434}
 435
 436static NetSocketState *net_socket_fd_init(NetClientState *peer,
 437                                          const char *model, const char *name,
 438                                          int fd, int is_connected,
 439                                          const char *mc, Error **errp)
 440{
 441    int so_type = -1, optlen=sizeof(so_type);
 442
 443    if(getsockopt(fd, SOL_SOCKET, SO_TYPE, (char *)&so_type,
 444        (socklen_t *)&optlen)< 0) {
 445        error_setg(errp, "can't get socket option SO_TYPE");
 446        closesocket(fd);
 447        return NULL;
 448    }
 449    switch(so_type) {
 450    case SOCK_DGRAM:
 451        return net_socket_fd_init_dgram(peer, model, name, fd, is_connected,
 452                                        mc, errp);
 453    case SOCK_STREAM:
 454        return net_socket_fd_init_stream(peer, model, name, fd, is_connected);
 455    default:
 456        error_setg(errp, "socket type=%d for fd=%d must be either"
 457                   " SOCK_DGRAM or SOCK_STREAM", so_type, fd);
 458        closesocket(fd);
 459    }
 460    return NULL;
 461}
 462
 463static void net_socket_accept(void *opaque)
 464{
 465    NetSocketState *s = opaque;
 466    struct sockaddr_in saddr;
 467    socklen_t len;
 468    int fd;
 469
 470    for(;;) {
 471        len = sizeof(saddr);
 472        fd = qemu_accept(s->listen_fd, (struct sockaddr *)&saddr, &len);
 473        if (fd < 0 && errno != EINTR) {
 474            return;
 475        } else if (fd >= 0) {
 476            qemu_set_fd_handler(s->listen_fd, NULL, NULL, NULL);
 477            break;
 478        }
 479    }
 480
 481    s->fd = fd;
 482    s->nc.link_down = false;
 483    net_socket_connect(s);
 484    snprintf(s->nc.info_str, sizeof(s->nc.info_str),
 485             "socket: connection from %s:%d",
 486             inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
 487}
 488
 489static int net_socket_listen_init(NetClientState *peer,
 490                                  const char *model,
 491                                  const char *name,
 492                                  const char *host_str,
 493                                  Error **errp)
 494{
 495    NetClientState *nc;
 496    NetSocketState *s;
 497    struct sockaddr_in saddr;
 498    int fd, ret;
 499
 500    if (parse_host_port(&saddr, host_str, errp) < 0) {
 501        return -1;
 502    }
 503
 504    fd = qemu_socket(PF_INET, SOCK_STREAM, 0);
 505    if (fd < 0) {
 506        error_setg_errno(errp, errno, "can't create stream socket");
 507        return -1;
 508    }
 509    qemu_set_nonblock(fd);
 510
 511    socket_set_fast_reuse(fd);
 512
 513    ret = bind(fd, (struct sockaddr *)&saddr, sizeof(saddr));
 514    if (ret < 0) {
 515        error_setg_errno(errp, errno, "can't bind ip=%s to socket",
 516                         inet_ntoa(saddr.sin_addr));
 517        closesocket(fd);
 518        return -1;
 519    }
 520    ret = listen(fd, 0);
 521    if (ret < 0) {
 522        error_setg_errno(errp, errno, "can't listen on socket");
 523        closesocket(fd);
 524        return -1;
 525    }
 526
 527    nc = qemu_new_net_client(&net_socket_info, peer, model, name);
 528    s = DO_UPCAST(NetSocketState, nc, nc);
 529    s->fd = -1;
 530    s->listen_fd = fd;
 531    s->nc.link_down = true;
 532    net_socket_rs_init(&s->rs, net_socket_rs_finalize, false);
 533
 534    qemu_set_fd_handler(s->listen_fd, net_socket_accept, NULL, s);
 535    return 0;
 536}
 537
 538static int net_socket_connect_init(NetClientState *peer,
 539                                   const char *model,
 540                                   const char *name,
 541                                   const char *host_str,
 542                                   Error **errp)
 543{
 544    NetSocketState *s;
 545    int fd, connected, ret;
 546    struct sockaddr_in saddr;
 547
 548    if (parse_host_port(&saddr, host_str, errp) < 0) {
 549        return -1;
 550    }
 551
 552    fd = qemu_socket(PF_INET, SOCK_STREAM, 0);
 553    if (fd < 0) {
 554        error_setg_errno(errp, errno, "can't create stream socket");
 555        return -1;
 556    }
 557    qemu_set_nonblock(fd);
 558
 559    connected = 0;
 560    for(;;) {
 561        ret = connect(fd, (struct sockaddr *)&saddr, sizeof(saddr));
 562        if (ret < 0) {
 563            if (errno == EINTR || errno == EWOULDBLOCK) {
 564                /* continue */
 565            } else if (errno == EINPROGRESS ||
 566                       errno == EALREADY ||
 567                       errno == EINVAL) {
 568                break;
 569            } else {
 570                error_setg_errno(errp, errno, "can't connect socket");
 571                closesocket(fd);
 572                return -1;
 573            }
 574        } else {
 575            connected = 1;
 576            break;
 577        }
 578    }
 579    s = net_socket_fd_init(peer, model, name, fd, connected, NULL, errp);
 580    if (!s) {
 581        return -1;
 582    }
 583
 584    snprintf(s->nc.info_str, sizeof(s->nc.info_str),
 585             "socket: connect to %s:%d",
 586             inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
 587    return 0;
 588}
 589
 590static int net_socket_mcast_init(NetClientState *peer,
 591                                 const char *model,
 592                                 const char *name,
 593                                 const char *host_str,
 594                                 const char *localaddr_str,
 595                                 Error **errp)
 596{
 597    NetSocketState *s;
 598    int fd;
 599    struct sockaddr_in saddr;
 600    struct in_addr localaddr, *param_localaddr;
 601
 602    if (parse_host_port(&saddr, host_str, errp) < 0) {
 603        return -1;
 604    }
 605
 606    if (localaddr_str != NULL) {
 607        if (inet_aton(localaddr_str, &localaddr) == 0) {
 608            error_setg(errp, "localaddr '%s' is not a valid IPv4 address",
 609                       localaddr_str);
 610            return -1;
 611        }
 612        param_localaddr = &localaddr;
 613    } else {
 614        param_localaddr = NULL;
 615    }
 616
 617    fd = net_socket_mcast_create(&saddr, param_localaddr, errp);
 618    if (fd < 0) {
 619        return -1;
 620    }
 621
 622    s = net_socket_fd_init(peer, model, name, fd, 0, NULL, errp);
 623    if (!s) {
 624        return -1;
 625    }
 626
 627    s->dgram_dst = saddr;
 628
 629    snprintf(s->nc.info_str, sizeof(s->nc.info_str),
 630             "socket: mcast=%s:%d",
 631             inet_ntoa(saddr.sin_addr), ntohs(saddr.sin_port));
 632    return 0;
 633
 634}
 635
 636static int net_socket_udp_init(NetClientState *peer,
 637                                 const char *model,
 638                                 const char *name,
 639                                 const char *rhost,
 640                                 const char *lhost,
 641                                 Error **errp)
 642{
 643    NetSocketState *s;
 644    int fd, ret;
 645    struct sockaddr_in laddr, raddr;
 646
 647    if (parse_host_port(&laddr, lhost, errp) < 0) {
 648        return -1;
 649    }
 650
 651    if (parse_host_port(&raddr, rhost, errp) < 0) {
 652        return -1;
 653    }
 654
 655    fd = qemu_socket(PF_INET, SOCK_DGRAM, 0);
 656    if (fd < 0) {
 657        error_setg_errno(errp, errno, "can't create datagram socket");
 658        return -1;
 659    }
 660
 661    ret = socket_set_fast_reuse(fd);
 662    if (ret < 0) {
 663        error_setg_errno(errp, errno,
 664                         "can't set socket option SO_REUSEADDR");
 665        closesocket(fd);
 666        return -1;
 667    }
 668    ret = bind(fd, (struct sockaddr *)&laddr, sizeof(laddr));
 669    if (ret < 0) {
 670        error_setg_errno(errp, errno, "can't bind ip=%s to socket",
 671                         inet_ntoa(laddr.sin_addr));
 672        closesocket(fd);
 673        return -1;
 674    }
 675    qemu_set_nonblock(fd);
 676
 677    s = net_socket_fd_init(peer, model, name, fd, 0, NULL, errp);
 678    if (!s) {
 679        return -1;
 680    }
 681
 682    s->dgram_dst = raddr;
 683
 684    snprintf(s->nc.info_str, sizeof(s->nc.info_str),
 685             "socket: udp=%s:%d",
 686             inet_ntoa(raddr.sin_addr), ntohs(raddr.sin_port));
 687    return 0;
 688}
 689
 690int net_init_socket(const Netdev *netdev, const char *name,
 691                    NetClientState *peer, Error **errp)
 692{
 693    const NetdevSocketOptions *sock;
 694
 695    assert(netdev->type == NET_CLIENT_DRIVER_SOCKET);
 696    sock = &netdev->u.socket;
 697
 698    if (sock->has_fd + sock->has_listen + sock->has_connect + sock->has_mcast +
 699        sock->has_udp != 1) {
 700        error_setg(errp, "exactly one of listen=, connect=, mcast= or udp="
 701                   " is required");
 702        return -1;
 703    }
 704
 705    if (sock->has_localaddr && !sock->has_mcast && !sock->has_udp) {
 706        error_setg(errp, "localaddr= is only valid with mcast= or udp=");
 707        return -1;
 708    }
 709
 710    if (sock->has_fd) {
 711        int fd;
 712
 713        fd = monitor_fd_param(cur_mon, sock->fd, errp);
 714        if (fd == -1) {
 715            return -1;
 716        }
 717        qemu_set_nonblock(fd);
 718        if (!net_socket_fd_init(peer, "socket", name, fd, 1, sock->mcast,
 719                                errp)) {
 720            return -1;
 721        }
 722        return 0;
 723    }
 724
 725    if (sock->has_listen) {
 726        if (net_socket_listen_init(peer, "socket", name, sock->listen, errp)
 727            < 0) {
 728            return -1;
 729        }
 730        return 0;
 731    }
 732
 733    if (sock->has_connect) {
 734        if (net_socket_connect_init(peer, "socket", name, sock->connect, errp)
 735            < 0) {
 736            return -1;
 737        }
 738        return 0;
 739    }
 740
 741    if (sock->has_mcast) {
 742        /* if sock->localaddr is missing, it has been initialized to "all bits
 743         * zero" */
 744        if (net_socket_mcast_init(peer, "socket", name, sock->mcast,
 745                                  sock->localaddr, errp) < 0) {
 746            return -1;
 747        }
 748        return 0;
 749    }
 750
 751    assert(sock->has_udp);
 752    if (!sock->has_localaddr) {
 753        error_setg(errp, "localaddr= is mandatory with udp=");
 754        return -1;
 755    }
 756    if (net_socket_udp_init(peer, "socket", name, sock->udp, sock->localaddr,
 757                            errp) < 0) {
 758        return -1;
 759    }
 760    return 0;
 761}
 762