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 *vlan,
 409                                 const char *stack)
 410 {
 411
 412     if (vlan) {
 413         NetClientState *nc;
 414         nc = net_hub_find_client_by_name(strtol(vlan, NULL, 0), stack);
 415         if (!nc) {
 416             monitor_printf(mon, "unrecognized (vlan-id, stackname) pair\n");
 417             return NULL;
 418         }
 419         if (strcmp(nc->model, "user")) {
 420             monitor_printf(mon, "invalid device specified\n");
 421             return NULL;
 422         }
 423         return DO_UPCAST(SlirpState, nc, nc);
 424     } else {
 425         if (QTAILQ_EMPTY(&slirp_stacks)) {
 426             monitor_printf(mon, "user mode network stack not in use\n");
 427             return NULL;
 428         }
 429         return QTAILQ_FIRST(&slirp_stacks);
 430     }
 431 }
 432
 433 void hmp_hostfwd_remove(Monitor *mon, const QDict *qdict)
 434 {
 435     struct in_addr host_addr = { .s_addr = INADDR_ANY };
 436     int host_port;
 437     char buf[256];
 438     const char *src_str, *p;
 439     SlirpState *s;
 440     int is_udp = 0;
 441     int err;
 442     const char *arg1 = qdict_get_str(qdict, "arg1");
 443     const char *arg2 = qdict_get_try_str(qdict, "arg2");
 444     const char *arg3 = qdict_get_try_str(qdict, "arg3");
 445
 446     if (arg2) {
 447         s = slirp_lookup(mon, arg1, arg2);
 448         src_str = arg3;
 449     } else {
 450         s = slirp_lookup(mon, NULL, NULL);
 451         src_str = arg1;
 452     }
 453     if (!s) {
 454         return;
 455     }
 456
 457     p = src_str;
 458     if (!p || get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 459         goto fail_syntax;
 460     }
 461
 462     if (!strcmp(buf, "tcp") || buf[0] == '\0') {
 463         is_udp = 0;
 464     } else if (!strcmp(buf, "udp")) {
 465         is_udp = 1;
 466     } else {
 467         goto fail_syntax;
 468     }
 469
 470     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 471         goto fail_syntax;
 472     }
 473     if (buf[0] != '\0' && !inet_aton(buf, &host_addr)) {
 474         goto fail_syntax;
 475     }
 476
 477     host_port = atoi(p);
 478
 479     err = slirp_remove_hostfwd(s->slirp, is_udp, host_addr, host_port);
 480
 481     monitor_printf(mon, "host forwarding rule for %s %s\n", src_str,
 482                    err ? "not found" : "removed");
 483     return;
 484
 485  fail_syntax:
 486     monitor_printf(mon, "invalid format\n");
 487 }
 488
 489 static int slirp_hostfwd(SlirpState *s, const char *redir_str,
 490                          int legacy_format, Error **errp)
 491 {
 492     struct in_addr host_addr = { .s_addr = INADDR_ANY };
 493     struct in_addr guest_addr = { .s_addr = 0 };
 494     int host_port, guest_port;
 495     const char *p;
 496     char buf[256];
 497     int is_udp;
 498     char *end;
 499     const char *fail_reason = "Unknown reason";
 500
 501     p = redir_str;
 502     if (!p || get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 503         fail_reason = "No : separators";
 504         goto fail_syntax;
 505     }
 506     if (!strcmp(buf, "tcp") || buf[0] == '\0') {
 507         is_udp = 0;
 508     } else if (!strcmp(buf, "udp")) {
 509         is_udp = 1;
 510     } else {
 511         fail_reason = "Bad protocol name";
 512         goto fail_syntax;
 513     }
 514
 515     if (!legacy_format) {
 516         if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 517             fail_reason = "Missing : separator";
 518             goto fail_syntax;
 519         }
 520         if (buf[0] != '\0' && !inet_aton(buf, &host_addr)) {
 521             fail_reason = "Bad host address";
 522             goto fail_syntax;
 523         }
 524     }
 525
 526     if (get_str_sep(buf, sizeof(buf), &p, legacy_format ? ':' : '-') < 0) {
 527         fail_reason = "Bad host port separator";
 528         goto fail_syntax;
 529     }
 530     host_port = strtol(buf, &end, 0);
 531     if (*end != '\0' || host_port < 0 || host_port > 65535) {
 532         fail_reason = "Bad host port";
 533         goto fail_syntax;
 534     }
 535
 536     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 537         fail_reason = "Missing guest address";
 538         goto fail_syntax;
 539     }
 540     if (buf[0] != '\0' && !inet_aton(buf, &guest_addr)) {
 541         fail_reason = "Bad guest address";
 542         goto fail_syntax;
 543     }
 544
 545     guest_port = strtol(p, &end, 0);
 546     if (*end != '\0' || guest_port < 1 || guest_port > 65535) {
 547         fail_reason = "Bad guest port";
 548         goto fail_syntax;
 549     }
 550
 551     if (slirp_add_hostfwd(s->slirp, is_udp, host_addr, host_port, guest_addr,
 552                           guest_port) < 0) {
 553         error_setg(errp, "Could not set up host forwarding rule '%s'",
 554                    redir_str);
 555         return -1;
 556     }
 557     return 0;
 558
 559  fail_syntax:
 560     error_setg(errp, "Invalid host forwarding rule '%s' (%s)", redir_str,
 561                fail_reason);
 562     return -1;
 563 }
 564
 565 void hmp_hostfwd_add(Monitor *mon, const QDict *qdict)
 566 {
 567     const char *redir_str;
 568     SlirpState *s;
 569     const char *arg1 = qdict_get_str(qdict, "arg1");
 570     const char *arg2 = qdict_get_try_str(qdict, "arg2");
 571     const char *arg3 = qdict_get_try_str(qdict, "arg3");
 572
 573     if (arg2) {
 574         s = slirp_lookup(mon, arg1, arg2);
 575         redir_str = arg3;
 576     } else {
 577         s = slirp_lookup(mon, NULL, NULL);
 578         redir_str = arg1;
 579     }
 580     if (s) {
 581         Error *err = NULL;
 582         if (slirp_hostfwd(s, redir_str, 0, &err) < 0) {
 583             error_report_err(err);
 584         }
 585     }
 586
 587 }
 588
 589 int net_slirp_redir(const char *redir_str)
 590 {
 591     struct slirp_config_str *config;
 592     Error *err = NULL;
 593     int res;
 594
 595     if (QTAILQ_EMPTY(&slirp_stacks)) {
 596         config = g_malloc(sizeof(*config));
 597         pstrcpy(config->str, sizeof(config->str), redir_str);
 598         config->flags = SLIRP_CFG_HOSTFWD | SLIRP_CFG_LEGACY;
 599         config->next = slirp_configs;
 600         slirp_configs = config;
 601         return 0;
 602     }
 603
 604     res = slirp_hostfwd(QTAILQ_FIRST(&slirp_stacks), redir_str, 1, &err);
 605     if (res < 0) {
 606         error_report_err(err);
 607     }
 608     return res;
 609 }
 610
 611 #ifndef _WIN32
 612
 613 /* automatic user mode samba server configuration */
 614 static void slirp_smb_cleanup(SlirpState *s)
 615 {
 616     int ret;
 617
 618     if (s->smb_dir) {
 619         gchar *cmd = g_strdup_printf("rm -rf %s", s->smb_dir);
 620         ret = system(cmd);
 621         if (ret == -1 || !WIFEXITED(ret)) {
 622             error_report("'%s' failed.", cmd);
 623         } else if (WEXITSTATUS(ret)) {
 624             error_report("'%s' failed. Error code: %d",
 625                          cmd, WEXITSTATUS(ret));
 626         }
 627         g_free(cmd);
 628         g_free(s->smb_dir);
 629         s->smb_dir = NULL;
 630     }
 631 }
 632
 633 static int slirp_smb(SlirpState* s, const char *exported_dir,
 634                      struct in_addr vserver_addr, Error **errp)
 635 {
 636     char *smb_conf;
 637     char *smb_cmdline;
 638     struct passwd *passwd;
 639     FILE *f;
 640
 641     passwd = getpwuid(geteuid());
 642     if (!passwd) {
 643         error_setg(errp, "Failed to retrieve user name");
 644         return -1;
 645     }
 646
 647     if (access(CONFIG_SMBD_COMMAND, F_OK)) {
 648         error_setg(errp, "Could not find '%s', please install it",
 649                    CONFIG_SMBD_COMMAND);
 650         return -1;
 651     }
 652
 653     if (access(exported_dir, R_OK | X_OK)) {
 654         error_setg(errp, "Error accessing shared directory '%s': %s",
 655                    exported_dir, strerror(errno));
 656         return -1;
 657     }
 658
 659     s->smb_dir = g_dir_make_tmp("qemu-smb.XXXXXX", NULL);
 660     if (!s->smb_dir) {
 661         error_setg(errp, "Could not create samba server dir");
 662         return -1;
 663     }
 664     smb_conf = g_strdup_printf("%s/%s", s->smb_dir, "smb.conf");
 665
 666     f = fopen(smb_conf, "w");
 667     if (!f) {
 668         slirp_smb_cleanup(s);
 669         error_setg(errp,
 670                    "Could not create samba server configuration file '%s'",
 671                     smb_conf);
 672         g_free(smb_conf);
 673         return -1;
 674     }
 675     fprintf(f,
 676             "[global]\n"
 677             "private dir=%s\n"
 678             "interfaces=127.0.0.1\n"
 679             "bind interfaces only=yes\n"
 680             "pid directory=%s\n"
 681             "lock directory=%s\n"
 682             "state directory=%s\n"
 683             "cache directory=%s\n"
 684             "ncalrpc dir=%s/ncalrpc\n"
 685             "log file=%s/log.smbd\n"
 686             "smb passwd file=%s/smbpasswd\n"
 687             "security = user\n"
 688             "map to guest = Bad User\n"
 689             "load printers = no\n"
 690             "printing = bsd\n"
 691             "disable spoolss = yes\n"
 692             "usershare max shares = 0\n"
 693             "[qemu]\n"
 694             "path=%s\n"
 695             "read only=no\n"
 696             "guest ok=yes\n"
 697             "force user=%s\n",
 698             s->smb_dir,
 699             s->smb_dir,
 700             s->smb_dir,
 701             s->smb_dir,
 702             s->smb_dir,
 703             s->smb_dir,
 704             s->smb_dir,
 705             s->smb_dir,
 706             exported_dir,
 707             passwd->pw_name
 708             );
 709     fclose(f);
 710
 711     smb_cmdline = g_strdup_printf("%s -l %s -s %s",
 712              CONFIG_SMBD_COMMAND, s->smb_dir, smb_conf);
 713     g_free(smb_conf);
 714
 715     if (slirp_add_exec(s->slirp, 0, smb_cmdline, &vserver_addr, 139) < 0 ||
 716         slirp_add_exec(s->slirp, 0, smb_cmdline, &vserver_addr, 445) < 0) {
 717         slirp_smb_cleanup(s);
 718         g_free(smb_cmdline);
 719         error_setg(errp, "Conflicting/invalid smbserver address");
 720         return -1;
 721     }
 722     g_free(smb_cmdline);
 723     return 0;
 724 }
 725
 726 /* automatic user mode samba server configuration (legacy interface) */
 727 int net_slirp_smb(const char *exported_dir)
 728 {
 729     struct in_addr vserver_addr = { .s_addr = 0 };
 730
 731     if (legacy_smb_export) {
 732         fprintf(stderr, "-smb given twice\n");
 733         return -1;
 734     }
 735     legacy_smb_export = exported_dir;
 736     if (!QTAILQ_EMPTY(&slirp_stacks)) {
 737         Error *err = NULL;
 738         int res = slirp_smb(QTAILQ_FIRST(&slirp_stacks), exported_dir,
 739                             vserver_addr, &err);
 740         if (res < 0) {
 741             error_report_err(err);
 742         }
 743         return res;
 744     }
 745     return 0;
 746 }
 747
 748 #endif /* !defined(_WIN32) */
 749
 750 struct GuestFwd {
 751     CharBackend hd;
 752     struct in_addr server;
 753     int port;
 754     Slirp *slirp;
 755 };
 756
 757 static int guestfwd_can_read(void *opaque)
 758 {
 759     struct GuestFwd *fwd = opaque;
 760     return slirp_socket_can_recv(fwd->slirp, fwd->server, fwd->port);
 761 }
 762
 763 static void guestfwd_read(void *opaque, const uint8_t *buf, int size)
 764 {
 765     struct GuestFwd *fwd = opaque;
 766     slirp_socket_recv(fwd->slirp, fwd->server, fwd->port, buf, size);
 767 }
 768
 769 static int slirp_guestfwd(SlirpState *s, const char *config_str,
 770                           int legacy_format, Error **errp)
 771 {
 772     struct in_addr server = { .s_addr = 0 };
 773     struct GuestFwd *fwd;
 774     const char *p;
 775     char buf[128];
 776     char *end;
 777     int port;
 778
 779     p = config_str;
 780     if (legacy_format) {
 781         if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 782             goto fail_syntax;
 783         }
 784     } else {
 785         if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 786             goto fail_syntax;
 787         }
 788         if (strcmp(buf, "tcp") && buf[0] != '\0') {
 789             goto fail_syntax;
 790         }
 791         if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 792             goto fail_syntax;
 793         }
 794         if (buf[0] != '\0' && !inet_aton(buf, &server)) {
 795             goto fail_syntax;
 796         }
 797         if (get_str_sep(buf, sizeof(buf), &p, '-') < 0) {
 798             goto fail_syntax;
 799         }
 800     }
 801     port = strtol(buf, &end, 10);
 802     if (*end != '\0' || port < 1 || port > 65535) {
 803         goto fail_syntax;
 804     }
 805
 806     snprintf(buf, sizeof(buf), "guestfwd.tcp.%d", port);
 807
 808     if ((strlen(p) > 4) && !strncmp(p, "cmd:", 4)) {
 809         if (slirp_add_exec(s->slirp, 0, &p[4], &server, port) < 0) {
 810             error_setg(errp, "Conflicting/invalid host:port in guest "
 811                        "forwarding rule '%s'", config_str);
 812             return -1;
 813         }
 814     } else {
 815         Error *err = NULL;
 816         Chardev *chr = qemu_chr_new(buf, p);
 817
 818         if (!chr) {
 819             error_setg(errp, "Could not open guest forwarding device '%s'",
 820                        buf);
 821             return -1;
 822         }
 823
 824         fwd = g_new(struct GuestFwd, 1);
 825         qemu_chr_fe_init(&fwd->hd, chr, &err);
 826         if (err) {
 827             error_propagate(errp, err);
 828             g_free(fwd);
 829             return -1;
 830         }
 831
 832         if (slirp_add_exec(s->slirp, 3, &fwd->hd, &server, port) < 0) {
 833             error_setg(errp, "Conflicting/invalid host:port in guest "
 834                        "forwarding rule '%s'", config_str);
 835             g_free(fwd);
 836             return -1;
 837         }
 838         fwd->server = server;
 839         fwd->port = port;
 840         fwd->slirp = s->slirp;
 841
 842         qemu_chr_fe_set_handlers(&fwd->hd, guestfwd_can_read, guestfwd_read,
 843                                  NULL, NULL, fwd, NULL, true);
 844     }
 845     return 0;
 846
 847  fail_syntax:
 848     error_setg(errp, "Invalid guest forwarding rule '%s'", config_str);
 849     return -1;
 850 }
 851
 852 void hmp_info_usernet(Monitor *mon, const QDict *qdict)
 853 {
 854     SlirpState *s;
 855
 856     QTAILQ_FOREACH(s, &slirp_stacks, entry) {
 857         int id;
 858         bool got_vlan_id = net_hub_id_for_client(&s->nc, &id) == 0;
 859         monitor_printf(mon, "VLAN %d (%s):\n",
 860                        got_vlan_id ? id : -1,
 861                        s->nc.name);
 862         slirp_connection_info(s->slirp, mon);
 863     }
 864 }
 865
 866 static void
 867 net_init_slirp_configs(const StringList *fwd, int flags)
 868 {
 869     while (fwd) {
 870         struct slirp_config_str *config;
 871
 872         config = g_malloc0(sizeof(*config));
 873         pstrcpy(config->str, sizeof(config->str), fwd->value->str);
 874         config->flags = flags;
 875         config->next = slirp_configs;
 876         slirp_configs = config;
 877
 878         fwd = fwd->next;
 879     }
 880 }
 881
 882 static const char **slirp_dnssearch(const StringList *dnsname)
 883 {
 884     const StringList *c = dnsname;
 885     size_t i = 0, num_opts = 0;
 886     const char **ret;
 887
 888     while (c) {
 889         num_opts++;
 890         c = c->next;
 891     }
 892
 893     if (num_opts == 0) {
 894         return NULL;
 895     }
 896
 897     ret = g_malloc((num_opts + 1) * sizeof(*ret));
 898     c = dnsname;
 899     while (c) {
 900         ret[i++] = c->value->str;
 901         c = c->next;
 902     }
 903     ret[i] = NULL;
 904     return ret;
 905 }
 906
 907 int net_init_slirp(const Netdev *netdev, const char *name,
 908                    NetClientState *peer, Error **errp)
 909 {
 910     struct slirp_config_str *config;
 911     char *vnet;
 912     int ret;
 913     const NetdevUserOptions *user;
 914     const char **dnssearch;
 915     bool ipv4 = true, ipv6 = true;
 916
 917     assert(netdev->type == NET_CLIENT_DRIVER_USER);
 918     user = &netdev->u.user;
 919
 920     if ((user->has_ipv6 && user->ipv6 && !user->has_ipv4) ||
 921         (user->has_ipv4 && !user->ipv4)) {
 922         ipv4 = 0;
 923     }
 924     if ((user->has_ipv4 && user->ipv4 && !user->has_ipv6) ||
 925         (user->has_ipv6 && !user->ipv6)) {
 926         ipv6 = 0;
 927     }
 928
 929     vnet = user->has_net ? g_strdup(user->net) :
 930            user->has_ip  ? g_strdup_printf("%s/24", user->ip) :
 931            NULL;
 932
 933     dnssearch = slirp_dnssearch(user->dnssearch);
 934
 935     /* all optional fields are initialized to "all bits zero" */
 936
 937     net_init_slirp_configs(user->hostfwd, SLIRP_CFG_HOSTFWD);
 938     net_init_slirp_configs(user->guestfwd, 0);
 939
 940     ret = net_slirp_init(peer, "user", name, user->q_restrict,
 941                          ipv4, vnet, user->host,
 942                          ipv6, user->ipv6_prefix, user->ipv6_prefixlen,
 943                          user->ipv6_host, user->hostname, user->tftp,
 944                          user->bootfile, user->dhcpstart,
 945                          user->dns, user->ipv6_dns, user->smb,
 946                          user->smbserver, dnssearch, errp);
 947
 948     while (slirp_configs) {
 949         config = slirp_configs;
 950         slirp_configs = config->next;
 951         g_free(config);
 952     }
 953
 954     g_free(vnet);
 955     g_free(dnssearch);
 956
 957     return ret;
 958 }