net/slirp.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 #include "net/slirp.h"
  26
  27
  28 #ifndef _WIN32
  29 #include <pwd.h>
  30 #include <sys/wait.h>
  31 #endif
  32 #include "net/net.h"
  33 #include "clients.h"
  34 #include "hub.h"
  35 #include "monitor/monitor.h"
  36 #include "qemu/error-report.h"
  37 #include "qemu/sockets.h"
  38 #include "slirp/libslirp.h"
  39 #include "slirp/ip6.h"
  40 #include "sysemu/char.h"
  41 #include "sysemu/sysemu.h"
  42 #include "qemu/cutils.h"
  43
  44 static int get_str_sep(char *buf, int buf_size, const char **pp, int sep)
  45 {
  46     const char *p, *p1;
  47     int len;
  48     p = *pp;
  49     p1 = strchr(p, sep);
  50     if (!p1)
  51         return -1;
  52     len = p1 - p;
  53     p1++;
  54     if (buf_size > 0) {
  55         if (len > buf_size - 1)
  56             len = buf_size - 1;
  57         memcpy(buf, p, len);
  58         buf[len] = '\0';
  59     }
  60     *pp = p1;
  61     return 0;
  62 }
  63
  64 /* slirp network adapter */
  65
  66 #define SLIRP_CFG_HOSTFWD 1
  67 #define SLIRP_CFG_LEGACY  2
  68
  69 struct slirp_config_str {
  70     struct slirp_config_str *next;
  71     int flags;
  72     char str[1024];
  73     int legacy_format;
  74 };
  75
  76 typedef struct SlirpState {
  77     NetClientState nc;
  78     QTAILQ_ENTRY(SlirpState) entry;
  79     Slirp *slirp;
  80     Notifier exit_notifier;
  81 #ifndef _WIN32
  82     char smb_dir[128];
  83 #endif
  84 } SlirpState;
  85
  86 static struct slirp_config_str *slirp_configs;
  87 const char *legacy_tftp_prefix;
  88 const char *legacy_bootp_filename;
  89 static QTAILQ_HEAD(slirp_stacks, SlirpState) slirp_stacks =
  90     QTAILQ_HEAD_INITIALIZER(slirp_stacks);
  91
  92 static int slirp_hostfwd(SlirpState *s, const char *redir_str,
  93                          int legacy_format);
  94 static int slirp_guestfwd(SlirpState *s, const char *config_str,
  95                           int legacy_format);
  96
  97 #ifndef _WIN32
  98 static const char *legacy_smb_export;
  99
 100 static int slirp_smb(SlirpState *s, const char *exported_dir,
 101                      struct in_addr vserver_addr);
 102 static void slirp_smb_cleanup(SlirpState *s);
 103 #else
 104 static inline void slirp_smb_cleanup(SlirpState *s) { }
 105 #endif
 106
 107 void slirp_output(void *opaque, const uint8_t *pkt, int pkt_len)
 108 {
 109     SlirpState *s = opaque;
 110
 111     qemu_send_packet(&s->nc, pkt, pkt_len);
 112 }
 113
 114 static ssize_t net_slirp_receive(NetClientState *nc, const uint8_t *buf, size_t size)
 115 {
 116     SlirpState *s = DO_UPCAST(SlirpState, nc, nc);
 117
 118     slirp_input(s->slirp, buf, size);
 119
 120     return size;
 121 }
 122
 123 static void slirp_smb_exit(Notifier *n, void *data)
 124 {
 125     SlirpState *s = container_of(n, SlirpState, exit_notifier);
 126     slirp_smb_cleanup(s);
 127 }
 128
 129 static void net_slirp_cleanup(NetClientState *nc)
 130 {
 131     SlirpState *s = DO_UPCAST(SlirpState, nc, nc);
 132
 133     slirp_cleanup(s->slirp);
 134     if (s->exit_notifier.notify) {
 135         qemu_remove_exit_notifier(&s->exit_notifier);
 136     }
 137     slirp_smb_cleanup(s);
 138     QTAILQ_REMOVE(&slirp_stacks, s, entry);
 139 }
 140
 141 static NetClientInfo net_slirp_info = {
 142     .type = NET_CLIENT_DRIVER_USER,
 143     .size = sizeof(SlirpState),
 144     .receive = net_slirp_receive,
 145     .cleanup = net_slirp_cleanup,
 146 };
 147
 148 static int net_slirp_init(NetClientState *peer, const char *model,
 149                           const char *name, int restricted,
 150                           bool ipv4, const char *vnetwork, const char *vhost,
 151                           bool ipv6, const char *vprefix6, int vprefix6_len,
 152                           const char *vhost6,
 153                           const char *vhostname, const char *tftp_export,
 154                           const char *bootfile, const char *vdhcp_start,
 155                           const char *vnameserver, const char *vnameserver6,
 156                           const char *smb_export, const char *vsmbserver,
 157                           const char **dnssearch)
 158 {
 159     /* default settings according to historic slirp */
 160     struct in_addr net  = { .s_addr = htonl(0x0a000200) }; /* 10.0.2.0 */
 161     struct in_addr mask = { .s_addr = htonl(0xffffff00) }; /* 255.255.255.0 */
 162     struct in_addr host = { .s_addr = htonl(0x0a000202) }; /* 10.0.2.2 */
 163     struct in_addr dhcp = { .s_addr = htonl(0x0a00020f) }; /* 10.0.2.15 */
 164     struct in_addr dns  = { .s_addr = htonl(0x0a000203) }; /* 10.0.2.3 */
 165     struct in6_addr ip6_prefix;
 166     struct in6_addr ip6_host;
 167     struct in6_addr ip6_dns;
 168 #ifndef _WIN32
 169     struct in_addr smbsrv = { .s_addr = 0 };
 170 #endif
 171     NetClientState *nc;
 172     SlirpState *s;
 173     char buf[20];
 174     uint32_t addr;
 175     int shift;
 176     char *end;
 177     struct slirp_config_str *config;
 178
 179     if (!ipv4 && (vnetwork || vhost || vnameserver)) {
 180         return -1;
 181     }
 182
 183     if (!ipv6 && (vprefix6 || vhost6 || vnameserver6)) {
 184         return -1;
 185     }
 186
 187     if (!ipv4 && !ipv6) {
 188         /* It doesn't make sense to disable both */
 189         return -1;
 190     }
 191
 192     if (!tftp_export) {
 193         tftp_export = legacy_tftp_prefix;
 194     }
 195     if (!bootfile) {
 196         bootfile = legacy_bootp_filename;
 197     }
 198
 199     if (vnetwork) {
 200         if (get_str_sep(buf, sizeof(buf), &vnetwork, '/') < 0) {
 201             if (!inet_aton(vnetwork, &net)) {
 202                 return -1;
 203             }
 204             addr = ntohl(net.s_addr);
 205             if (!(addr & 0x80000000)) {
 206                 mask.s_addr = htonl(0xff000000); /* class A */
 207             } else if ((addr & 0xfff00000) == 0xac100000) {
 208                 mask.s_addr = htonl(0xfff00000); /* priv. 172.16.0.0/12 */
 209             } else if ((addr & 0xc0000000) == 0x80000000) {
 210                 mask.s_addr = htonl(0xffff0000); /* class B */
 211             } else if ((addr & 0xffff0000) == 0xc0a80000) {
 212                 mask.s_addr = htonl(0xffff0000); /* priv. 192.168.0.0/16 */
 213             } else if ((addr & 0xffff0000) == 0xc6120000) {
 214                 mask.s_addr = htonl(0xfffe0000); /* tests 198.18.0.0/15 */
 215             } else if ((addr & 0xe0000000) == 0xe0000000) {
 216                 mask.s_addr = htonl(0xffffff00); /* class C */
 217             } else {
 218                 mask.s_addr = htonl(0xfffffff0); /* multicast/reserved */
 219             }
 220         } else {
 221             if (!inet_aton(buf, &net)) {
 222                 return -1;
 223             }
 224             shift = strtol(vnetwork, &end, 10);
 225             if (*end != '\0') {
 226                 if (!inet_aton(vnetwork, &mask)) {
 227                     return -1;
 228                 }
 229             } else if (shift < 4 || shift > 32) {
 230                 return -1;
 231             } else {
 232                 mask.s_addr = htonl(0xffffffff << (32 - shift));
 233             }
 234         }
 235         net.s_addr &= mask.s_addr;
 236         host.s_addr = net.s_addr | (htonl(0x0202) & ~mask.s_addr);
 237         dhcp.s_addr = net.s_addr | (htonl(0x020f) & ~mask.s_addr);
 238         dns.s_addr  = net.s_addr | (htonl(0x0203) & ~mask.s_addr);
 239     }
 240
 241     if (vhost && !inet_aton(vhost, &host)) {
 242         return -1;
 243     }
 244     if ((host.s_addr & mask.s_addr) != net.s_addr) {
 245         return -1;
 246     }
 247
 248     if (vnameserver && !inet_aton(vnameserver, &dns)) {
 249         return -1;
 250     }
 251     if ((dns.s_addr & mask.s_addr) != net.s_addr ||
 252         dns.s_addr == host.s_addr) {
 253         return -1;
 254     }
 255
 256     if (vdhcp_start && !inet_aton(vdhcp_start, &dhcp)) {
 257         return -1;
 258     }
 259     if ((dhcp.s_addr & mask.s_addr) != net.s_addr ||
 260         dhcp.s_addr == host.s_addr || dhcp.s_addr == dns.s_addr) {
 261         return -1;
 262     }
 263
 264 #ifndef _WIN32
 265     if (vsmbserver && !inet_aton(vsmbserver, &smbsrv)) {
 266         return -1;
 267     }
 268 #endif
 269
 270 #if defined(_WIN32) && (_WIN32_WINNT < 0x0600)
 271     /* No inet_pton helper before Vista... */
 272     if (vprefix6) {
 273         /* Unsupported */
 274         return -1;
 275     }
 276     memset(&ip6_prefix, 0, sizeof(ip6_prefix));
 277     ip6_prefix.s6_addr[0] = 0xfe;
 278     ip6_prefix.s6_addr[1] = 0xc0;
 279 #else
 280     if (!vprefix6) {
 281         vprefix6 = "fec0::";
 282     }
 283     if (!inet_pton(AF_INET6, vprefix6, &ip6_prefix)) {
 284         return -1;
 285     }
 286 #endif
 287
 288     if (!vprefix6_len) {
 289         vprefix6_len = 64;
 290     }
 291     if (vprefix6_len < 0 || vprefix6_len > 126) {
 292         return -1;
 293     }
 294
 295     if (vhost6) {
 296 #if defined(_WIN32) && (_WIN32_WINNT < 0x0600)
 297         return -1;
 298 #else
 299         if (!inet_pton(AF_INET6, vhost6, &ip6_host)) {
 300             return -1;
 301         }
 302         if (!in6_equal_net(&ip6_prefix, &ip6_host, vprefix6_len)) {
 303             return -1;
 304         }
 305 #endif
 306     } else {
 307         ip6_host = ip6_prefix;
 308         ip6_host.s6_addr[15] |= 2;
 309     }
 310
 311     if (vnameserver6) {
 312 #if defined(_WIN32) && (_WIN32_WINNT < 0x0600)
 313         return -1;
 314 #else
 315         if (!inet_pton(AF_INET6, vnameserver6, &ip6_dns)) {
 316             return -1;
 317         }
 318         if (!in6_equal_net(&ip6_prefix, &ip6_dns, vprefix6_len)) {
 319             return -1;
 320         }
 321 #endif
 322     } else {
 323         ip6_dns = ip6_prefix;
 324         ip6_dns.s6_addr[15] |= 3;
 325     }
 326
 327
 328     nc = qemu_new_net_client(&net_slirp_info, peer, model, name);
 329
 330     snprintf(nc->info_str, sizeof(nc->info_str),
 331              "net=%s,restrict=%s", inet_ntoa(net),
 332              restricted ? "on" : "off");
 333
 334     s = DO_UPCAST(SlirpState, nc, nc);
 335
 336     s->slirp = slirp_init(restricted, ipv4, net, mask, host,
 337                           ipv6, ip6_prefix, vprefix6_len, ip6_host,
 338                           vhostname, tftp_export, bootfile, dhcp,
 339                           dns, ip6_dns, dnssearch, s);
 340     QTAILQ_INSERT_TAIL(&slirp_stacks, s, entry);
 341
 342     for (config = slirp_configs; config; config = config->next) {
 343         if (config->flags & SLIRP_CFG_HOSTFWD) {
 344             if (slirp_hostfwd(s, config->str,
 345                               config->flags & SLIRP_CFG_LEGACY) < 0)
 346                 goto error;
 347         } else {
 348             if (slirp_guestfwd(s, config->str,
 349                                config->flags & SLIRP_CFG_LEGACY) < 0)
 350                 goto error;
 351         }
 352     }
 353 #ifndef _WIN32
 354     if (!smb_export) {
 355         smb_export = legacy_smb_export;
 356     }
 357     if (smb_export) {
 358         if (slirp_smb(s, smb_export, smbsrv) < 0)
 359             goto error;
 360     }
 361 #endif
 362
 363     s->exit_notifier.notify = slirp_smb_exit;
 364     qemu_add_exit_notifier(&s->exit_notifier);
 365     return 0;
 366
 367 error:
 368     qemu_del_net_client(nc);
 369     return -1;
 370 }
 371
 372 static SlirpState *slirp_lookup(Monitor *mon, const char *vlan,
 373                                 const char *stack)
 374 {
 375
 376     if (vlan) {
 377         NetClientState *nc;
 378         nc = net_hub_find_client_by_name(strtol(vlan, NULL, 0), stack);
 379         if (!nc) {
 380             monitor_printf(mon, "unrecognized (vlan-id, stackname) pair\n");
 381             return NULL;
 382         }
 383         if (strcmp(nc->model, "user")) {
 384             monitor_printf(mon, "invalid device specified\n");
 385             return NULL;
 386         }
 387         return DO_UPCAST(SlirpState, nc, nc);
 388     } else {
 389         if (QTAILQ_EMPTY(&slirp_stacks)) {
 390             monitor_printf(mon, "user mode network stack not in use\n");
 391             return NULL;
 392         }
 393         return QTAILQ_FIRST(&slirp_stacks);
 394     }
 395 }
 396
 397 void hmp_hostfwd_remove(Monitor *mon, const QDict *qdict)
 398 {
 399     struct in_addr host_addr = { .s_addr = INADDR_ANY };
 400     int host_port;
 401     char buf[256];
 402     const char *src_str, *p;
 403     SlirpState *s;
 404     int is_udp = 0;
 405     int err;
 406     const char *arg1 = qdict_get_str(qdict, "arg1");
 407     const char *arg2 = qdict_get_try_str(qdict, "arg2");
 408     const char *arg3 = qdict_get_try_str(qdict, "arg3");
 409
 410     if (arg2) {
 411         s = slirp_lookup(mon, arg1, arg2);
 412         src_str = arg3;
 413     } else {
 414         s = slirp_lookup(mon, NULL, NULL);
 415         src_str = arg1;
 416     }
 417     if (!s) {
 418         return;
 419     }
 420
 421     p = src_str;
 422     if (!p || get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 423         goto fail_syntax;
 424     }
 425
 426     if (!strcmp(buf, "tcp") || buf[0] == '\0') {
 427         is_udp = 0;
 428     } else if (!strcmp(buf, "udp")) {
 429         is_udp = 1;
 430     } else {
 431         goto fail_syntax;
 432     }
 433
 434     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 435         goto fail_syntax;
 436     }
 437     if (buf[0] != '\0' && !inet_aton(buf, &host_addr)) {
 438         goto fail_syntax;
 439     }
 440
 441     host_port = atoi(p);
 442
 443     err = slirp_remove_hostfwd(s->slirp, is_udp, host_addr, host_port);
 444
 445     monitor_printf(mon, "host forwarding rule for %s %s\n", src_str,
 446                    err ? "not found" : "removed");
 447     return;
 448
 449  fail_syntax:
 450     monitor_printf(mon, "invalid format\n");
 451 }
 452
 453 static int slirp_hostfwd(SlirpState *s, const char *redir_str,
 454                          int legacy_format)
 455 {
 456     struct in_addr host_addr = { .s_addr = INADDR_ANY };
 457     struct in_addr guest_addr = { .s_addr = 0 };
 458     int host_port, guest_port;
 459     const char *p;
 460     char buf[256];
 461     int is_udp;
 462     char *end;
 463
 464     p = redir_str;
 465     if (!p || get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 466         goto fail_syntax;
 467     }
 468     if (!strcmp(buf, "tcp") || buf[0] == '\0') {
 469         is_udp = 0;
 470     } else if (!strcmp(buf, "udp")) {
 471         is_udp = 1;
 472     } else {
 473         goto fail_syntax;
 474     }
 475
 476     if (!legacy_format) {
 477         if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 478             goto fail_syntax;
 479         }
 480         if (buf[0] != '\0' && !inet_aton(buf, &host_addr)) {
 481             goto fail_syntax;
 482         }
 483     }
 484
 485     if (get_str_sep(buf, sizeof(buf), &p, legacy_format ? ':' : '-') < 0) {
 486         goto fail_syntax;
 487     }
 488     host_port = strtol(buf, &end, 0);
 489     if (*end != '\0' || host_port < 1 || host_port > 65535) {
 490         goto fail_syntax;
 491     }
 492
 493     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 494         goto fail_syntax;
 495     }
 496     if (buf[0] != '\0' && !inet_aton(buf, &guest_addr)) {
 497         goto fail_syntax;
 498     }
 499
 500     guest_port = strtol(p, &end, 0);
 501     if (*end != '\0' || guest_port < 1 || guest_port > 65535) {
 502         goto fail_syntax;
 503     }
 504
 505     if (slirp_add_hostfwd(s->slirp, is_udp, host_addr, host_port, guest_addr,
 506                           guest_port) < 0) {
 507         error_report("could not set up host forwarding rule '%s'",
 508                      redir_str);
 509         return -1;
 510     }
 511     return 0;
 512
 513  fail_syntax:
 514     error_report("invalid host forwarding rule '%s'", redir_str);
 515     return -1;
 516 }
 517
 518 void hmp_hostfwd_add(Monitor *mon, const QDict *qdict)
 519 {
 520     const char *redir_str;
 521     SlirpState *s;
 522     const char *arg1 = qdict_get_str(qdict, "arg1");
 523     const char *arg2 = qdict_get_try_str(qdict, "arg2");
 524     const char *arg3 = qdict_get_try_str(qdict, "arg3");
 525
 526     if (arg2) {
 527         s = slirp_lookup(mon, arg1, arg2);
 528         redir_str = arg3;
 529     } else {
 530         s = slirp_lookup(mon, NULL, NULL);
 531         redir_str = arg1;
 532     }
 533     if (s) {
 534         slirp_hostfwd(s, redir_str, 0);
 535     }
 536
 537 }
 538
 539 int net_slirp_redir(const char *redir_str)
 540 {
 541     struct slirp_config_str *config;
 542
 543     if (QTAILQ_EMPTY(&slirp_stacks)) {
 544         config = g_malloc(sizeof(*config));
 545         pstrcpy(config->str, sizeof(config->str), redir_str);
 546         config->flags = SLIRP_CFG_HOSTFWD | SLIRP_CFG_LEGACY;
 547         config->next = slirp_configs;
 548         slirp_configs = config;
 549         return 0;
 550     }
 551
 552     return slirp_hostfwd(QTAILQ_FIRST(&slirp_stacks), redir_str, 1);
 553 }
 554
 555 #ifndef _WIN32
 556
 557 /* automatic user mode samba server configuration */
 558 static void slirp_smb_cleanup(SlirpState *s)
 559 {
 560     char cmd[128];
 561     int ret;
 562
 563     if (s->smb_dir[0] != '\0') {
 564         snprintf(cmd, sizeof(cmd), "rm -rf %s", s->smb_dir);
 565         ret = system(cmd);
 566         if (ret == -1 || !WIFEXITED(ret)) {
 567             error_report("'%s' failed.", cmd);
 568         } else if (WEXITSTATUS(ret)) {
 569             error_report("'%s' failed. Error code: %d",
 570                          cmd, WEXITSTATUS(ret));
 571         }
 572         s->smb_dir[0] = '\0';
 573     }
 574 }
 575
 576 static int slirp_smb(SlirpState* s, const char *exported_dir,
 577                      struct in_addr vserver_addr)
 578 {
 579     char smb_conf[128];
 580     char smb_cmdline[128];
 581     struct passwd *passwd;
 582     FILE *f;
 583
 584     passwd = getpwuid(geteuid());
 585     if (!passwd) {
 586         error_report("failed to retrieve user name");
 587         return -1;
 588     }
 589
 590     if (access(CONFIG_SMBD_COMMAND, F_OK)) {
 591         error_report("could not find '%s', please install it",
 592                      CONFIG_SMBD_COMMAND);
 593         return -1;
 594     }
 595
 596     if (access(exported_dir, R_OK | X_OK)) {
 597         error_report("error accessing shared directory '%s': %s",
 598                      exported_dir, strerror(errno));
 599         return -1;
 600     }
 601
 602     snprintf(s->smb_dir, sizeof(s->smb_dir), "/tmp/qemu-smb.XXXXXX");
 603     if (!mkdtemp(s->smb_dir)) {
 604         error_report("could not create samba server dir '%s'", s->smb_dir);
 605         s->smb_dir[0] = 0;
 606         return -1;
 607     }
 608     snprintf(smb_conf, sizeof(smb_conf), "%s/%s", s->smb_dir, "smb.conf");
 609
 610     f = fopen(smb_conf, "w");
 611     if (!f) {
 612         slirp_smb_cleanup(s);
 613         error_report("could not create samba server configuration file '%s'",
 614                      smb_conf);
 615         return -1;
 616     }
 617     fprintf(f,
 618             "[global]\n"
 619             "private dir=%s\n"
 620             "interfaces=127.0.0.1\n"
 621             "bind interfaces only=yes\n"
 622             "pid directory=%s\n"
 623             "lock directory=%s\n"
 624             "state directory=%s\n"
 625             "cache directory=%s\n"
 626             "ncalrpc dir=%s/ncalrpc\n"
 627             "log file=%s/log.smbd\n"
 628             "smb passwd file=%s/smbpasswd\n"
 629             "security = user\n"
 630             "map to guest = Bad User\n"
 631             "load printers = no\n"
 632             "printing = bsd\n"
 633             "disable spoolss = yes\n"
 634             "usershare max shares = 0\n"
 635             "[qemu]\n"
 636             "path=%s\n"
 637             "read only=no\n"
 638             "guest ok=yes\n"
 639             "force user=%s\n",
 640             s->smb_dir,
 641             s->smb_dir,
 642             s->smb_dir,
 643             s->smb_dir,
 644             s->smb_dir,
 645             s->smb_dir,
 646             s->smb_dir,
 647             s->smb_dir,
 648             exported_dir,
 649             passwd->pw_name
 650             );
 651     fclose(f);
 652
 653     snprintf(smb_cmdline, sizeof(smb_cmdline), "%s -l %s -s %s",
 654              CONFIG_SMBD_COMMAND, s->smb_dir, smb_conf);
 655
 656     if (slirp_add_exec(s->slirp, 0, smb_cmdline, &vserver_addr, 139) < 0 ||
 657         slirp_add_exec(s->slirp, 0, smb_cmdline, &vserver_addr, 445) < 0) {
 658         slirp_smb_cleanup(s);
 659         error_report("conflicting/invalid smbserver address");
 660         return -1;
 661     }
 662     return 0;
 663 }
 664
 665 /* automatic user mode samba server configuration (legacy interface) */
 666 int net_slirp_smb(const char *exported_dir)
 667 {
 668     struct in_addr vserver_addr = { .s_addr = 0 };
 669
 670     if (legacy_smb_export) {
 671         fprintf(stderr, "-smb given twice\n");
 672         return -1;
 673     }
 674     legacy_smb_export = exported_dir;
 675     if (!QTAILQ_EMPTY(&slirp_stacks)) {
 676         return slirp_smb(QTAILQ_FIRST(&slirp_stacks), exported_dir,
 677                          vserver_addr);
 678     }
 679     return 0;
 680 }
 681
 682 #endif /* !defined(_WIN32) */
 683
 684 struct GuestFwd {
 685     CharDriverState *hd;
 686     struct in_addr server;
 687     int port;
 688     Slirp *slirp;
 689 };
 690
 691 static int guestfwd_can_read(void *opaque)
 692 {
 693     struct GuestFwd *fwd = opaque;
 694     return slirp_socket_can_recv(fwd->slirp, fwd->server, fwd->port);
 695 }
 696
 697 static void guestfwd_read(void *opaque, const uint8_t *buf, int size)
 698 {
 699     struct GuestFwd *fwd = opaque;
 700     slirp_socket_recv(fwd->slirp, fwd->server, fwd->port, buf, size);
 701 }
 702
 703 static int slirp_guestfwd(SlirpState *s, const char *config_str,
 704                           int legacy_format)
 705 {
 706     struct in_addr server = { .s_addr = 0 };
 707     struct GuestFwd *fwd;
 708     const char *p;
 709     char buf[128];
 710     char *end;
 711     int port;
 712
 713     p = config_str;
 714     if (legacy_format) {
 715         if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 716             goto fail_syntax;
 717         }
 718     } else {
 719         if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 720             goto fail_syntax;
 721         }
 722         if (strcmp(buf, "tcp") && buf[0] != '\0') {
 723             goto fail_syntax;
 724         }
 725         if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 726             goto fail_syntax;
 727         }
 728         if (buf[0] != '\0' && !inet_aton(buf, &server)) {
 729             goto fail_syntax;
 730         }
 731         if (get_str_sep(buf, sizeof(buf), &p, '-') < 0) {
 732             goto fail_syntax;
 733         }
 734     }
 735     port = strtol(buf, &end, 10);
 736     if (*end != '\0' || port < 1 || port > 65535) {
 737         goto fail_syntax;
 738     }
 739
 740     snprintf(buf, sizeof(buf), "guestfwd.tcp.%d", port);
 741
 742     if ((strlen(p) > 4) && !strncmp(p, "cmd:", 4)) {
 743         if (slirp_add_exec(s->slirp, 0, &p[4], &server, port) < 0) {
 744             error_report("conflicting/invalid host:port in guest forwarding "
 745                          "rule '%s'", config_str);
 746             return -1;
 747         }
 748     } else {
 749         fwd = g_new(struct GuestFwd, 1);
 750         fwd->hd = qemu_chr_new(buf, p, NULL);
 751         if (!fwd->hd) {
 752             error_report("could not open guest forwarding device '%s'", buf);
 753             g_free(fwd);
 754             return -1;
 755         }
 756
 757         if (slirp_add_exec(s->slirp, 3, fwd->hd, &server, port) < 0) {
 758             error_report("conflicting/invalid host:port in guest forwarding "
 759                          "rule '%s'", config_str);
 760             g_free(fwd);
 761             return -1;
 762         }
 763         fwd->server = server;
 764         fwd->port = port;
 765         fwd->slirp = s->slirp;
 766
 767         qemu_chr_fe_claim_no_fail(fwd->hd);
 768         qemu_chr_add_handlers(fwd->hd, guestfwd_can_read, guestfwd_read,
 769                               NULL, fwd);
 770     }
 771     return 0;
 772
 773  fail_syntax:
 774     error_report("invalid guest forwarding rule '%s'", config_str);
 775     return -1;
 776 }
 777
 778 void hmp_info_usernet(Monitor *mon, const QDict *qdict)
 779 {
 780     SlirpState *s;
 781
 782     QTAILQ_FOREACH(s, &slirp_stacks, entry) {
 783         int id;
 784         bool got_vlan_id = net_hub_id_for_client(&s->nc, &id) == 0;
 785         monitor_printf(mon, "VLAN %d (%s):\n",
 786                        got_vlan_id ? id : -1,
 787                        s->nc.name);
 788         slirp_connection_info(s->slirp, mon);
 789     }
 790 }
 791
 792 static void
 793 net_init_slirp_configs(const StringList *fwd, int flags)
 794 {
 795     while (fwd) {
 796         struct slirp_config_str *config;
 797
 798         config = g_malloc0(sizeof(*config));
 799         pstrcpy(config->str, sizeof(config->str), fwd->value->str);
 800         config->flags = flags;
 801         config->next = slirp_configs;
 802         slirp_configs = config;
 803
 804         fwd = fwd->next;
 805     }
 806 }
 807
 808 static const char **slirp_dnssearch(const StringList *dnsname)
 809 {
 810     const StringList *c = dnsname;
 811     size_t i = 0, num_opts = 0;
 812     const char **ret;
 813
 814     while (c) {
 815         num_opts++;
 816         c = c->next;
 817     }
 818
 819     if (num_opts == 0) {
 820         return NULL;
 821     }
 822
 823     ret = g_malloc((num_opts + 1) * sizeof(*ret));
 824     c = dnsname;
 825     while (c) {
 826         ret[i++] = c->value->str;
 827         c = c->next;
 828     }
 829     ret[i] = NULL;
 830     return ret;
 831 }
 832
 833 int net_init_slirp(const Netdev *netdev, const char *name,
 834                    NetClientState *peer, Error **errp)
 835 {
 836     /* FIXME error_setg(errp, ...) on failure */
 837     struct slirp_config_str *config;
 838     char *vnet;
 839     int ret;
 840     const NetdevUserOptions *user;
 841     const char **dnssearch;
 842     bool ipv4 = true, ipv6 = true;
 843
 844     assert(netdev->type == NET_CLIENT_DRIVER_USER);
 845     user = &netdev->u.user;
 846
 847     if ((user->has_ipv6 && user->ipv6 && !user->has_ipv4) ||
 848         (user->has_ipv4 && !user->ipv4)) {
 849         ipv4 = 0;
 850     }
 851     if ((user->has_ipv4 && user->ipv4 && !user->has_ipv6) ||
 852         (user->has_ipv6 && !user->ipv6)) {
 853         ipv6 = 0;
 854     }
 855
 856     vnet = user->has_net ? g_strdup(user->net) :
 857            user->has_ip  ? g_strdup_printf("%s/24", user->ip) :
 858            NULL;
 859
 860     dnssearch = slirp_dnssearch(user->dnssearch);
 861
 862     /* all optional fields are initialized to "all bits zero" */
 863
 864     net_init_slirp_configs(user->hostfwd, SLIRP_CFG_HOSTFWD);
 865     net_init_slirp_configs(user->guestfwd, 0);
 866
 867     ret = net_slirp_init(peer, "user", name, user->q_restrict,
 868                          ipv4, vnet, user->host,
 869                          ipv6, user->ipv6_prefix, user->ipv6_prefixlen,
 870                          user->ipv6_host, user->hostname, user->tftp,
 871                          user->bootfile, user->dhcpstart,
 872                          user->dns, user->ipv6_dns, user->smb,
 873                          user->smbserver, dnssearch);
 874
 875     while (slirp_configs) {
 876         config = slirp_configs;
 877         slirp_configs = config->next;
 878         g_free(config);
 879     }
 880
 881     g_free(vnet);
 882     g_free(dnssearch);
 883
 884     return ret;
 885 }
 886
 887 int net_slirp_parse_legacy(QemuOptsList *opts_list, const char *optarg, int *ret)
 888 {
 889     if (strcmp(opts_list->name, "net") != 0 ||
 890         strncmp(optarg, "channel,", strlen("channel,")) != 0) {
 891         return 0;
 892     }
 893
 894     error_report("The '-net channel' option is deprecated. "
 895                  "Please use '-netdev user,guestfwd=...' instead.");
 896
 897     /* handle legacy -net channel,port:chr */
 898     optarg += strlen("channel,");
 899
 900     if (QTAILQ_EMPTY(&slirp_stacks)) {
 901         struct slirp_config_str *config;
 902
 903         config = g_malloc(sizeof(*config));
 904         pstrcpy(config->str, sizeof(config->str), optarg);
 905         config->flags = SLIRP_CFG_LEGACY;
 906         config->next = slirp_configs;
 907         slirp_configs = config;
 908         *ret = 0;
 909     } else {
 910         *ret = slirp_guestfwd(QTAILQ_FIRST(&slirp_stacks), optarg, 1);
 911     }
 912
 913     return 1;
 914 }
 915