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