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
  25 #include "qemu/osdep.h"
  26 #include "net/slirp.h"
  27
  28
  29 #ifndef _WIN32
  30 #include <pwd.h>
  31 #include <sys/wait.h>
  32 #endif
  33 #include "net/net.h"
  34 #include "clients.h"
  35 #include "hub.h"
  36 #include "monitor/monitor.h"
  37 #include "qemu/error-report.h"
  38 #include "qemu/sockets.h"
  39 #include "slirp/libslirp.h"
  40 #include "slirp/ip6.h"
  41 #include "chardev/char-fe.h"
  42 #include "sysemu/sysemu.h"
  43 #include "qemu/cutils.h"
  44 #include "qapi/error.h"
  45 #include "qapi/qmp/qdict.h"
  46
  47 static int get_str_sep(char *buf, int buf_size, const char **pp, int sep)
  48 {
  49     const char *p, *p1;
  50     int len;
  51     p = *pp;
  52     p1 = strchr(p, sep);
  53     if (!p1)
  54         return -1;
  55     len = p1 - p;
  56     p1++;
  57     if (buf_size > 0) {
  58         if (len > buf_size - 1)
  59             len = buf_size - 1;
  60         memcpy(buf, p, len);
  61         buf[len] = '\0';
  62     }
  63     *pp = p1;
  64     return 0;
  65 }
  66
  67 /* slirp network adapter */
  68
  69 #define SLIRP_CFG_HOSTFWD 1
  70 #define SLIRP_CFG_LEGACY  2
  71
  72 struct slirp_config_str {
  73     struct slirp_config_str *next;
  74     int flags;
  75     char str[1024];
  76     int legacy_format;
  77 };
  78
  79 typedef struct SlirpState {
  80     NetClientState nc;
  81     QTAILQ_ENTRY(SlirpState) entry;
  82     Slirp *slirp;
  83     Notifier exit_notifier;
  84 #ifndef _WIN32
  85     gchar *smb_dir;
  86 #endif
  87 } SlirpState;
  88
  89 static struct slirp_config_str *slirp_configs;
  90 const char *legacy_tftp_prefix;
  91 const char *legacy_bootp_filename;
  92 static QTAILQ_HEAD(slirp_stacks, SlirpState) slirp_stacks =
  93     QTAILQ_HEAD_INITIALIZER(slirp_stacks);
  94
  95 static int slirp_hostfwd(SlirpState *s, const char *redir_str,
  96                          int legacy_format, Error **errp);
  97 static int slirp_guestfwd(SlirpState *s, const char *config_str,
  98                           int legacy_format, Error **errp);
  99
 100 #ifndef _WIN32
 101 static const char *legacy_smb_export;
 102
 103 static int slirp_smb(SlirpState *s, const char *exported_dir,
 104                      struct in_addr vserver_addr, Error **errp);
 105 static void slirp_smb_cleanup(SlirpState *s);
 106 #else
 107 static inline void slirp_smb_cleanup(SlirpState *s) { }
 108 #endif
 109
 110 void slirp_output(void *opaque, const uint8_t *pkt, int pkt_len)
 111 {
 112     SlirpState *s = opaque;
 113
 114     qemu_send_packet(&s->nc, pkt, pkt_len);
 115 }
 116
 117 static ssize_t net_slirp_receive(NetClientState *nc, const uint8_t *buf, size_t size)
 118 {
 119     SlirpState *s = DO_UPCAST(SlirpState, nc, nc);
 120
 121     slirp_input(s->slirp, buf, size);
 122
 123     return size;
 124 }
 125
 126 static void slirp_smb_exit(Notifier *n, void *data)
 127 {
 128     SlirpState *s = container_of(n, SlirpState, exit_notifier);
 129     slirp_smb_cleanup(s);
 130 }
 131
 132 static void net_slirp_cleanup(NetClientState *nc)
 133 {
 134     SlirpState *s = DO_UPCAST(SlirpState, nc, nc);
 135
 136     slirp_cleanup(s->slirp);
 137     if (s->exit_notifier.notify) {
 138         qemu_remove_exit_notifier(&s->exit_notifier);
 139     }
 140     slirp_smb_cleanup(s);
 141     QTAILQ_REMOVE(&slirp_stacks, s, entry);
 142 }
 143
 144 static NetClientInfo net_slirp_info = {
 145     .type = NET_CLIENT_DRIVER_USER,
 146     .size = sizeof(SlirpState),
 147     .receive = net_slirp_receive,
 148     .cleanup = net_slirp_cleanup,
 149 };
 150
 151 static int net_slirp_init(NetClientState *peer, const char *model,
 152                           const char *name, int restricted,
 153                           bool ipv4, const char *vnetwork, const char *vhost,
 154                           bool ipv6, const char *vprefix6, int vprefix6_len,
 155                           const char *vhost6,
 156                           const char *vhostname, const char *tftp_export,
 157                           const char *bootfile, const char *vdhcp_start,
 158                           const char *vnameserver, const char *vnameserver6,
 159                           const char *smb_export, const char *vsmbserver,
 160                           const char **dnssearch, Error **errp)
 161 {
 162     /* default settings according to historic slirp */
 163     struct in_addr net  = { .s_addr = htonl(0x0a000200) }; /* 10.0.2.0 */
 164     struct in_addr mask = { .s_addr = htonl(0xffffff00) }; /* 255.255.255.0 */
 165     struct in_addr host = { .s_addr = htonl(0x0a000202) }; /* 10.0.2.2 */
 166     struct in_addr dhcp = { .s_addr = htonl(0x0a00020f) }; /* 10.0.2.15 */
 167     struct in_addr dns  = { .s_addr = htonl(0x0a000203) }; /* 10.0.2.3 */
 168     struct in6_addr ip6_prefix;
 169     struct in6_addr ip6_host;
 170     struct in6_addr ip6_dns;
 171 #ifndef _WIN32
 172     struct in_addr smbsrv = { .s_addr = 0 };
 173 #endif
 174     NetClientState *nc;
 175     SlirpState *s;
 176     char buf[20];
 177     uint32_t addr;
 178     int shift;
 179     char *end;
 180     struct slirp_config_str *config;
 181
 182     if (!ipv4 && (vnetwork || vhost || vnameserver)) {
 183         error_setg(errp, "IPv4 disabled but netmask/host/dns provided");
 184         return -1;
 185     }
 186
 187     if (!ipv6 && (vprefix6 || vhost6 || vnameserver6)) {
 188         error_setg(errp, "IPv6 disabled but prefix/host6/dns6 provided");
 189         return -1;
 190     }
 191
 192     if (!ipv4 && !ipv6) {
 193         /* It doesn't make sense to disable both */
 194         error_setg(errp, "IPv4 and IPv6 disabled");
 195         return -1;
 196     }
 197
 198     if (!tftp_export) {
 199         tftp_export = legacy_tftp_prefix;
 200     }
 201     if (!bootfile) {
 202         bootfile = legacy_bootp_filename;
 203     }
 204
 205     if (vnetwork) {
 206         if (get_str_sep(buf, sizeof(buf), &vnetwork, '/') < 0) {
 207             if (!inet_aton(vnetwork, &net)) {
 208                 error_setg(errp, "Failed to parse netmask");
 209                 return -1;
 210             }
 211             addr = ntohl(net.s_addr);
 212             if (!(addr & 0x80000000)) {
 213                 mask.s_addr = htonl(0xff000000); /* class A */
 214             } else if ((addr & 0xfff00000) == 0xac100000) {
 215                 mask.s_addr = htonl(0xfff00000); /* priv. 172.16.0.0/12 */
 216             } else if ((addr & 0xc0000000) == 0x80000000) {
 217                 mask.s_addr = htonl(0xffff0000); /* class B */
 218             } else if ((addr & 0xffff0000) == 0xc0a80000) {
 219                 mask.s_addr = htonl(0xffff0000); /* priv. 192.168.0.0/16 */
 220             } else if ((addr & 0xffff0000) == 0xc6120000) {
 221                 mask.s_addr = htonl(0xfffe0000); /* tests 198.18.0.0/15 */
 222             } else if ((addr & 0xe0000000) == 0xe0000000) {
 223                 mask.s_addr = htonl(0xffffff00); /* class C */
 224             } else {
 225                 mask.s_addr = htonl(0xfffffff0); /* multicast/reserved */
 226             }
 227         } else {
 228             if (!inet_aton(buf, &net)) {
 229                 error_setg(errp, "Failed to parse netmask");
 230                 return -1;
 231             }
 232             shift = strtol(vnetwork, &end, 10);
 233             if (*end != '\0') {
 234                 if (!inet_aton(vnetwork, &mask)) {
 235                     error_setg(errp,
 236                                "Failed to parse netmask (trailing chars)");
 237                     return -1;
 238                 }
 239             } else if (shift < 4 || shift > 32) {
 240                 error_setg(errp,
 241                            "Invalid netmask provided (must be in range 4-32)");
 242                 return -1;
 243             } else {
 244                 mask.s_addr = htonl(0xffffffff << (32 - shift));
 245             }
 246         }
 247         net.s_addr &= mask.s_addr;
 248         host.s_addr = net.s_addr | (htonl(0x0202) & ~mask.s_addr);
 249         dhcp.s_addr = net.s_addr | (htonl(0x020f) & ~mask.s_addr);
 250         dns.s_addr  = net.s_addr | (htonl(0x0203) & ~mask.s_addr);
 251     }
 252
 253     if (vhost && !inet_aton(vhost, &host)) {
 254         error_setg(errp, "Failed to parse host");
 255         return -1;
 256     }
 257     if ((host.s_addr & mask.s_addr) != net.s_addr) {
 258         error_setg(errp, "Host doesn't belong to network");
 259         return -1;
 260     }
 261
 262     if (vnameserver && !inet_aton(vnameserver, &dns)) {
 263         error_setg(errp, "Failed to parse DNS");
 264         return -1;
 265     }
 266     if ((dns.s_addr & mask.s_addr) != net.s_addr) {
 267         error_setg(errp, "DNS doesn't belong to network");
 268         return -1;
 269     }
 270     if (dns.s_addr == host.s_addr) {
 271         error_setg(errp, "DNS must be different from host");
 272         return -1;
 273     }
 274
 275     if (vdhcp_start && !inet_aton(vdhcp_start, &dhcp)) {
 276         error_setg(errp, "Failed to parse DHCP start address");
 277         return -1;
 278     }
 279     if ((dhcp.s_addr & mask.s_addr) != net.s_addr) {
 280         error_setg(errp, "DHCP doesn't belong to network");
 281         return -1;
 282     }
 283     if (dhcp.s_addr == host.s_addr || dhcp.s_addr == dns.s_addr) {
 284         error_setg(errp, "DNS must be different from host and DNS");
 285         return -1;
 286     }
 287
 288 #ifndef _WIN32
 289     if (vsmbserver && !inet_aton(vsmbserver, &smbsrv)) {
 290         error_setg(errp, "Failed to parse SMB address");
 291         return -1;
 292     }
 293 #endif
 294
 295 #if defined(_WIN32) && (_WIN32_WINNT < 0x0600)
 296     /* No inet_pton helper before Vista... */
 297     if (vprefix6) {
 298         /* Unsupported */
 299         error_setg(errp, "IPv6 prefix not supported");
 300         return -1;
 301     }
 302     memset(&ip6_prefix, 0, sizeof(ip6_prefix));
 303     ip6_prefix.s6_addr[0] = 0xfe;
 304     ip6_prefix.s6_addr[1] = 0xc0;
 305 #else
 306     if (!vprefix6) {
 307         vprefix6 = "fec0::";
 308     }
 309     if (!inet_pton(AF_INET6, vprefix6, &ip6_prefix)) {
 310         error_setg(errp, "Failed to parse IPv6 prefix");
 311         return -1;
 312     }
 313 #endif
 314
 315     if (!vprefix6_len) {
 316         vprefix6_len = 64;
 317     }
 318     if (vprefix6_len < 0 || vprefix6_len > 126) {
 319         error_setg(errp,
 320                    "Invalid prefix provided (prefix len must be in range 0-126");
 321         return -1;
 322     }
 323
 324     if (vhost6) {
 325 #if defined(_WIN32) && (_WIN32_WINNT < 0x0600)
 326         error_setg(errp, "IPv6 host not supported");
 327         return -1;
 328 #else
 329         if (!inet_pton(AF_INET6, vhost6, &ip6_host)) {
 330             error_setg(errp, "Failed to parse IPv6 host");
 331             return -1;
 332         }
 333         if (!in6_equal_net(&ip6_prefix, &ip6_host, vprefix6_len)) {
 334             error_setg(errp, "IPv6 Host doesn't belong to network");
 335             return -1;
 336         }
 337 #endif
 338     } else {
 339         ip6_host = ip6_prefix;
 340         ip6_host.s6_addr[15] |= 2;
 341     }
 342
 343     if (vnameserver6) {
 344 #if defined(_WIN32) && (_WIN32_WINNT < 0x0600)
 345         error_setg(errp, "IPv6 DNS not supported");
 346         return -1;
 347 #else
 348         if (!inet_pton(AF_INET6, vnameserver6, &ip6_dns)) {
 349             error_setg(errp, "Failed to parse IPv6 DNS");
 350             return -1;
 351         }
 352         if (!in6_equal_net(&ip6_prefix, &ip6_dns, vprefix6_len)) {
 353             error_setg(errp, "IPv6 DNS doesn't belong to network");
 354             return -1;
 355         }
 356 #endif
 357     } else {
 358         ip6_dns = ip6_prefix;
 359         ip6_dns.s6_addr[15] |= 3;
 360     }
 361
 362
 363     nc = qemu_new_net_client(&net_slirp_info, peer, model, name);
 364
 365     snprintf(nc->info_str, sizeof(nc->info_str),
 366              "net=%s,restrict=%s", inet_ntoa(net),
 367              restricted ? "on" : "off");
 368
 369     s = DO_UPCAST(SlirpState, nc, nc);
 370
 371     s->slirp = slirp_init(restricted, ipv4, net, mask, host,
 372                           ipv6, ip6_prefix, vprefix6_len, ip6_host,
 373                           vhostname, tftp_export, bootfile, dhcp,
 374                           dns, ip6_dns, dnssearch, s);
 375     QTAILQ_INSERT_TAIL(&slirp_stacks, s, entry);
 376
 377     for (config = slirp_configs; config; config = config->next) {
 378         if (config->flags & SLIRP_CFG_HOSTFWD) {
 379             if (slirp_hostfwd(s, config->str,
 380                               config->flags & SLIRP_CFG_LEGACY, errp) < 0) {
 381                 goto error;
 382             }
 383         } else {
 384             if (slirp_guestfwd(s, config->str,
 385                                config->flags & SLIRP_CFG_LEGACY, errp) < 0) {
 386                 goto error;
 387             }
 388         }
 389     }
 390 #ifndef _WIN32
 391     if (!smb_export) {
 392         smb_export = legacy_smb_export;
 393     }
 394     if (smb_export) {
 395         if (slirp_smb(s, smb_export, smbsrv, errp) < 0) {
 396             goto error;
 397         }
 398     }
 399 #endif
 400
 401     s->exit_notifier.notify = slirp_smb_exit;
 402     qemu_add_exit_notifier(&s->exit_notifier);
 403     return 0;
 404
 405 error:
 406     qemu_del_net_client(nc);
 407     return -1;
 408 }
 409
 410 static SlirpState *slirp_lookup(Monitor *mon, const char *hub_id,
 411                                 const char *name)
 412 {
 413     if (name) {
 414         NetClientState *nc;
 415         if (hub_id) {
 416             nc = net_hub_find_client_by_name(strtol(hub_id, NULL, 0), name);
 417             if (!nc) {
 418                 monitor_printf(mon, "unrecognized (vlan-id, stackname) pair\n");
 419                 return NULL;
 420             }
 421         } else {
 422             nc = qemu_find_netdev(name);
 423             if (!nc) {
 424                 monitor_printf(mon, "unrecognized netdev id '%s'\n", name);
 425                 return NULL;
 426             }
 427         }
 428         if (strcmp(nc->model, "user")) {
 429             monitor_printf(mon, "invalid device specified\n");
 430             return NULL;
 431         }
 432         return DO_UPCAST(SlirpState, nc, nc);
 433     } else {
 434         if (QTAILQ_EMPTY(&slirp_stacks)) {
 435             monitor_printf(mon, "user mode network stack not in use\n");
 436             return NULL;
 437         }
 438         return QTAILQ_FIRST(&slirp_stacks);
 439     }
 440 }
 441
 442 void hmp_hostfwd_remove(Monitor *mon, const QDict *qdict)
 443 {
 444     struct in_addr host_addr = { .s_addr = INADDR_ANY };
 445     int host_port;
 446     char buf[256];
 447     const char *src_str, *p;
 448     SlirpState *s;
 449     int is_udp = 0;
 450     int err;
 451     const char *arg1 = qdict_get_str(qdict, "arg1");
 452     const char *arg2 = qdict_get_try_str(qdict, "arg2");
 453     const char *arg3 = qdict_get_try_str(qdict, "arg3");
 454
 455     if (arg3) {
 456         s = slirp_lookup(mon, arg1, arg2);
 457         src_str = arg3;
 458     } else if (arg2) {
 459         s = slirp_lookup(mon, NULL, arg1);
 460         src_str = arg2;
 461     } else {
 462         s = slirp_lookup(mon, NULL, NULL);
 463         src_str = arg1;
 464     }
 465     if (!s) {
 466         return;
 467     }
 468
 469     p = src_str;
 470     if (!p || get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 471         goto fail_syntax;
 472     }
 473
 474     if (!strcmp(buf, "tcp") || buf[0] == '\0') {
 475         is_udp = 0;
 476     } else if (!strcmp(buf, "udp")) {
 477         is_udp = 1;
 478     } else {
 479         goto fail_syntax;
 480     }
 481
 482     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 483         goto fail_syntax;
 484     }
 485     if (buf[0] != '\0' && !inet_aton(buf, &host_addr)) {
 486         goto fail_syntax;
 487     }
 488
 489     host_port = atoi(p);
 490
 491     err = slirp_remove_hostfwd(s->slirp, is_udp, host_addr, host_port);
 492
 493     monitor_printf(mon, "host forwarding rule for %s %s\n", src_str,
 494                    err ? "not found" : "removed");
 495     return;
 496
 497  fail_syntax:
 498     monitor_printf(mon, "invalid format\n");
 499 }
 500
 501 static int slirp_hostfwd(SlirpState *s, const char *redir_str,
 502                          int legacy_format, Error **errp)
 503 {
 504     struct in_addr host_addr = { .s_addr = INADDR_ANY };
 505     struct in_addr guest_addr = { .s_addr = 0 };
 506     int host_port, guest_port;
 507     const char *p;
 508     char buf[256];
 509     int is_udp;
 510     char *end;
 511     const char *fail_reason = "Unknown reason";
 512
 513     p = redir_str;
 514     if (!p || get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 515         fail_reason = "No : separators";
 516         goto fail_syntax;
 517     }
 518     if (!strcmp(buf, "tcp") || buf[0] == '\0') {
 519         is_udp = 0;
 520     } else if (!strcmp(buf, "udp")) {
 521         is_udp = 1;
 522     } else {
 523         fail_reason = "Bad protocol name";
 524         goto fail_syntax;
 525     }
 526
 527     if (!legacy_format) {
 528         if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 529             fail_reason = "Missing : separator";
 530             goto fail_syntax;
 531         }
 532         if (buf[0] != '\0' && !inet_aton(buf, &host_addr)) {
 533             fail_reason = "Bad host address";
 534             goto fail_syntax;
 535         }
 536     }
 537
 538     if (get_str_sep(buf, sizeof(buf), &p, legacy_format ? ':' : '-') < 0) {
 539         fail_reason = "Bad host port separator";
 540         goto fail_syntax;
 541     }
 542     host_port = strtol(buf, &end, 0);
 543     if (*end != '\0' || host_port < 0 || host_port > 65535) {
 544         fail_reason = "Bad host port";
 545         goto fail_syntax;
 546     }
 547
 548     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 549         fail_reason = "Missing guest address";
 550         goto fail_syntax;
 551     }
 552     if (buf[0] != '\0' && !inet_aton(buf, &guest_addr)) {
 553         fail_reason = "Bad guest address";
 554         goto fail_syntax;
 555     }
 556
 557     guest_port = strtol(p, &end, 0);
 558     if (*end != '\0' || guest_port < 1 || guest_port > 65535) {
 559         fail_reason = "Bad guest port";
 560         goto fail_syntax;
 561     }
 562
 563     if (slirp_add_hostfwd(s->slirp, is_udp, host_addr, host_port, guest_addr,
 564                           guest_port) < 0) {
 565         error_setg(errp, "Could not set up host forwarding rule '%s'",
 566                    redir_str);
 567         return -1;
 568     }
 569     return 0;
 570
 571  fail_syntax:
 572     error_setg(errp, "Invalid host forwarding rule '%s' (%s)", redir_str,
 573                fail_reason);
 574     return -1;
 575 }
 576
 577 void hmp_hostfwd_add(Monitor *mon, const QDict *qdict)
 578 {
 579     const char *redir_str;
 580     SlirpState *s;
 581     const char *arg1 = qdict_get_str(qdict, "arg1");
 582     const char *arg2 = qdict_get_try_str(qdict, "arg2");
 583     const char *arg3 = qdict_get_try_str(qdict, "arg3");
 584
 585     if (arg3) {
 586         s = slirp_lookup(mon, arg1, arg2);
 587         redir_str = arg3;
 588     } else if (arg2) {
 589         s = slirp_lookup(mon, NULL, arg1);
 590         redir_str = arg2;
 591     } else {
 592         s = slirp_lookup(mon, NULL, NULL);
 593         redir_str = arg1;
 594     }
 595     if (s) {
 596         Error *err = NULL;
 597         if (slirp_hostfwd(s, redir_str, 0, &err) < 0) {
 598             error_report_err(err);
 599         }
 600     }
 601
 602 }
 603
 604 int net_slirp_redir(const char *redir_str)
 605 {
 606     struct slirp_config_str *config;
 607     Error *err = NULL;
 608     int res;
 609
 610     if (QTAILQ_EMPTY(&slirp_stacks)) {
 611         config = g_malloc(sizeof(*config));
 612         pstrcpy(config->str, sizeof(config->str), redir_str);
 613         config->flags = SLIRP_CFG_HOSTFWD | SLIRP_CFG_LEGACY;
 614         config->next = slirp_configs;
 615         slirp_configs = config;
 616         return 0;
 617     }
 618
 619     res = slirp_hostfwd(QTAILQ_FIRST(&slirp_stacks), redir_str, 1, &err);
 620     if (res < 0) {
 621         error_report_err(err);
 622     }
 623     return res;
 624 }
 625
 626 #ifndef _WIN32
 627
 628 /* automatic user mode samba server configuration */
 629 static void slirp_smb_cleanup(SlirpState *s)
 630 {
 631     int ret;
 632
 633     if (s->smb_dir) {
 634         gchar *cmd = g_strdup_printf("rm -rf %s", s->smb_dir);
 635         ret = system(cmd);
 636         if (ret == -1 || !WIFEXITED(ret)) {
 637             error_report("'%s' failed.", cmd);
 638         } else if (WEXITSTATUS(ret)) {
 639             error_report("'%s' failed. Error code: %d",
 640                          cmd, WEXITSTATUS(ret));
 641         }
 642         g_free(cmd);
 643         g_free(s->smb_dir);
 644         s->smb_dir = NULL;
 645     }
 646 }
 647
 648 static int slirp_smb(SlirpState* s, const char *exported_dir,
 649                      struct in_addr vserver_addr, Error **errp)
 650 {
 651     char *smb_conf;
 652     char *smb_cmdline;
 653     struct passwd *passwd;
 654     FILE *f;
 655
 656     passwd = getpwuid(geteuid());
 657     if (!passwd) {
 658         error_setg(errp, "Failed to retrieve user name");
 659         return -1;
 660     }
 661
 662     if (access(CONFIG_SMBD_COMMAND, F_OK)) {
 663         error_setg(errp, "Could not find '%s', please install it",
 664                    CONFIG_SMBD_COMMAND);
 665         return -1;
 666     }
 667
 668     if (access(exported_dir, R_OK | X_OK)) {
 669         error_setg(errp, "Error accessing shared directory '%s': %s",
 670                    exported_dir, strerror(errno));
 671         return -1;
 672     }
 673
 674     s->smb_dir = g_dir_make_tmp("qemu-smb.XXXXXX", NULL);
 675     if (!s->smb_dir) {
 676         error_setg(errp, "Could not create samba server dir");
 677         return -1;
 678     }
 679     smb_conf = g_strdup_printf("%s/%s", s->smb_dir, "smb.conf");
 680
 681     f = fopen(smb_conf, "w");
 682     if (!f) {
 683         slirp_smb_cleanup(s);
 684         error_setg(errp,
 685                    "Could not create samba server configuration file '%s'",
 686                     smb_conf);
 687         g_free(smb_conf);
 688         return -1;
 689     }
 690     fprintf(f,
 691             "[global]\n"
 692             "private dir=%s\n"
 693             "interfaces=127.0.0.1\n"
 694             "bind interfaces only=yes\n"
 695             "pid directory=%s\n"
 696             "lock directory=%s\n"
 697             "state directory=%s\n"
 698             "cache directory=%s\n"
 699             "ncalrpc dir=%s/ncalrpc\n"
 700             "log file=%s/log.smbd\n"
 701             "smb passwd file=%s/smbpasswd\n"
 702             "security = user\n"
 703             "map to guest = Bad User\n"
 704             "load printers = no\n"
 705             "printing = bsd\n"
 706             "disable spoolss = yes\n"
 707             "usershare max shares = 0\n"
 708             "[qemu]\n"
 709             "path=%s\n"
 710             "read only=no\n"
 711             "guest ok=yes\n"
 712             "force user=%s\n",
 713             s->smb_dir,
 714             s->smb_dir,
 715             s->smb_dir,
 716             s->smb_dir,
 717             s->smb_dir,
 718             s->smb_dir,
 719             s->smb_dir,
 720             s->smb_dir,
 721             exported_dir,
 722             passwd->pw_name
 723             );
 724     fclose(f);
 725
 726     smb_cmdline = g_strdup_printf("%s -l %s -s %s",
 727              CONFIG_SMBD_COMMAND, s->smb_dir, smb_conf);
 728     g_free(smb_conf);
 729
 730     if (slirp_add_exec(s->slirp, 0, smb_cmdline, &vserver_addr, 139) < 0 ||
 731         slirp_add_exec(s->slirp, 0, smb_cmdline, &vserver_addr, 445) < 0) {
 732         slirp_smb_cleanup(s);
 733         g_free(smb_cmdline);
 734         error_setg(errp, "Conflicting/invalid smbserver address");
 735         return -1;
 736     }
 737     g_free(smb_cmdline);
 738     return 0;
 739 }
 740
 741 /* automatic user mode samba server configuration (legacy interface) */
 742 int net_slirp_smb(const char *exported_dir)
 743 {
 744     struct in_addr vserver_addr = { .s_addr = 0 };
 745
 746     if (legacy_smb_export) {
 747         fprintf(stderr, "-smb given twice\n");
 748         return -1;
 749     }
 750     legacy_smb_export = exported_dir;
 751     if (!QTAILQ_EMPTY(&slirp_stacks)) {
 752         Error *err = NULL;
 753         int res = slirp_smb(QTAILQ_FIRST(&slirp_stacks), exported_dir,
 754                             vserver_addr, &err);
 755         if (res < 0) {
 756             error_report_err(err);
 757         }
 758         return res;
 759     }
 760     return 0;
 761 }
 762
 763 #endif /* !defined(_WIN32) */
 764
 765 struct GuestFwd {
 766     CharBackend hd;
 767     struct in_addr server;
 768     int port;
 769     Slirp *slirp;
 770 };
 771
 772 static int guestfwd_can_read(void *opaque)
 773 {
 774     struct GuestFwd *fwd = opaque;
 775     return slirp_socket_can_recv(fwd->slirp, fwd->server, fwd->port);
 776 }
 777
 778 static void guestfwd_read(void *opaque, const uint8_t *buf, int size)
 779 {
 780     struct GuestFwd *fwd = opaque;
 781     slirp_socket_recv(fwd->slirp, fwd->server, fwd->port, buf, size);
 782 }
 783
 784 static int slirp_guestfwd(SlirpState *s, const char *config_str,
 785                           int legacy_format, Error **errp)
 786 {
 787     struct in_addr server = { .s_addr = 0 };
 788     struct GuestFwd *fwd;
 789     const char *p;
 790     char buf[128];
 791     char *end;
 792     int port;
 793
 794     p = config_str;
 795     if (legacy_format) {
 796         if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 797             goto fail_syntax;
 798         }
 799     } else {
 800         if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 801             goto fail_syntax;
 802         }
 803         if (strcmp(buf, "tcp") && buf[0] != '\0') {
 804             goto fail_syntax;
 805         }
 806         if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 807             goto fail_syntax;
 808         }
 809         if (buf[0] != '\0' && !inet_aton(buf, &server)) {
 810             goto fail_syntax;
 811         }
 812         if (get_str_sep(buf, sizeof(buf), &p, '-') < 0) {
 813             goto fail_syntax;
 814         }
 815     }
 816     port = strtol(buf, &end, 10);
 817     if (*end != '\0' || port < 1 || port > 65535) {
 818         goto fail_syntax;
 819     }
 820
 821     snprintf(buf, sizeof(buf), "guestfwd.tcp.%d", port);
 822
 823     if ((strlen(p) > 4) && !strncmp(p, "cmd:", 4)) {
 824         if (slirp_add_exec(s->slirp, 0, &p[4], &server, port) < 0) {
 825             error_setg(errp, "Conflicting/invalid host:port in guest "
 826                        "forwarding rule '%s'", config_str);
 827             return -1;
 828         }
 829     } else {
 830         Error *err = NULL;
 831         Chardev *chr = qemu_chr_new(buf, p);
 832
 833         if (!chr) {
 834             error_setg(errp, "Could not open guest forwarding device '%s'",
 835                        buf);
 836             return -1;
 837         }
 838
 839         fwd = g_new(struct GuestFwd, 1);
 840         qemu_chr_fe_init(&fwd->hd, chr, &err);
 841         if (err) {
 842             error_propagate(errp, err);
 843             g_free(fwd);
 844             return -1;
 845         }
 846
 847         if (slirp_add_exec(s->slirp, 3, &fwd->hd, &server, port) < 0) {
 848             error_setg(errp, "Conflicting/invalid host:port in guest "
 849                        "forwarding rule '%s'", config_str);
 850             g_free(fwd);
 851             return -1;
 852         }
 853         fwd->server = server;
 854         fwd->port = port;
 855         fwd->slirp = s->slirp;
 856
 857         qemu_chr_fe_set_handlers(&fwd->hd, guestfwd_can_read, guestfwd_read,
 858                                  NULL, NULL, fwd, NULL, true);
 859     }
 860     return 0;
 861
 862  fail_syntax:
 863     error_setg(errp, "Invalid guest forwarding rule '%s'", config_str);
 864     return -1;
 865 }
 866
 867 void hmp_info_usernet(Monitor *mon, const QDict *qdict)
 868 {
 869     SlirpState *s;
 870
 871     QTAILQ_FOREACH(s, &slirp_stacks, entry) {
 872         int id;
 873         bool got_vlan_id = net_hub_id_for_client(&s->nc, &id) == 0;
 874         monitor_printf(mon, "VLAN %d (%s):\n",
 875                        got_vlan_id ? id : -1,
 876                        s->nc.name);
 877         slirp_connection_info(s->slirp, mon);
 878     }
 879 }
 880
 881 static void
 882 net_init_slirp_configs(const StringList *fwd, int flags)
 883 {
 884     while (fwd) {
 885         struct slirp_config_str *config;
 886
 887         config = g_malloc0(sizeof(*config));
 888         pstrcpy(config->str, sizeof(config->str), fwd->value->str);
 889         config->flags = flags;
 890         config->next = slirp_configs;
 891         slirp_configs = config;
 892
 893         fwd = fwd->next;
 894     }
 895 }
 896
 897 static const char **slirp_dnssearch(const StringList *dnsname)
 898 {
 899     const StringList *c = dnsname;
 900     size_t i = 0, num_opts = 0;
 901     const char **ret;
 902
 903     while (c) {
 904         num_opts++;
 905         c = c->next;
 906     }
 907
 908     if (num_opts == 0) {
 909         return NULL;
 910     }
 911
 912     ret = g_malloc((num_opts + 1) * sizeof(*ret));
 913     c = dnsname;
 914     while (c) {
 915         ret[i++] = c->value->str;
 916         c = c->next;
 917     }
 918     ret[i] = NULL;
 919     return ret;
 920 }
 921
 922 int net_init_slirp(const Netdev *netdev, const char *name,
 923                    NetClientState *peer, Error **errp)
 924 {
 925     struct slirp_config_str *config;
 926     char *vnet;
 927     int ret;
 928     const NetdevUserOptions *user;
 929     const char **dnssearch;
 930     bool ipv4 = true, ipv6 = true;
 931
 932     assert(netdev->type == NET_CLIENT_DRIVER_USER);
 933     user = &netdev->u.user;
 934
 935     if ((user->has_ipv6 && user->ipv6 && !user->has_ipv4) ||
 936         (user->has_ipv4 && !user->ipv4)) {
 937         ipv4 = 0;
 938     }
 939     if ((user->has_ipv4 && user->ipv4 && !user->has_ipv6) ||
 940         (user->has_ipv6 && !user->ipv6)) {
 941         ipv6 = 0;
 942     }
 943
 944     vnet = user->has_net ? g_strdup(user->net) :
 945            user->has_ip  ? g_strdup_printf("%s/24", user->ip) :
 946            NULL;
 947
 948     dnssearch = slirp_dnssearch(user->dnssearch);
 949
 950     /* all optional fields are initialized to "all bits zero" */
 951
 952     net_init_slirp_configs(user->hostfwd, SLIRP_CFG_HOSTFWD);
 953     net_init_slirp_configs(user->guestfwd, 0);
 954
 955     ret = net_slirp_init(peer, "user", name, user->q_restrict,
 956                          ipv4, vnet, user->host,
 957                          ipv6, user->ipv6_prefix, user->ipv6_prefixlen,
 958                          user->ipv6_host, user->hostname, user->tftp,
 959                          user->bootfile, user->dhcpstart,
 960                          user->dns, user->ipv6_dns, user->smb,
 961                          user->smbserver, dnssearch, errp);
 962
 963     while (slirp_configs) {
 964         config = slirp_configs;
 965         slirp_configs = config->next;
 966         g_free(config);
 967     }
 968
 969     g_free(vnet);
 970     g_free(dnssearch);
 971
 972     return ret;
 973 }