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