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 "qemu/log.h"
  27 #include "net/slirp.h"
  28
  29
  30 #ifndef _WIN32
  31 #include <pwd.h>
  32 #include <sys/wait.h>
  33 #endif
  34 #include "net/net.h"
  35 #include "clients.h"
  36 #include "hub.h"
  37 #include "monitor/monitor.h"
  38 #include "qemu/error-report.h"
  39 #include "qemu/sockets.h"
  40 #include "slirp/libslirp.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 #include "util.h"
  47
  48 static int get_str_sep(char *buf, int buf_size, const char **pp, int sep)
  49 {
  50     const char *p, *p1;
  51     int len;
  52     p = *pp;
  53     p1 = strchr(p, sep);
  54     if (!p1)
  55         return -1;
  56     len = p1 - p;
  57     p1++;
  58     if (buf_size > 0) {
  59         if (len > buf_size - 1)
  60             len = buf_size - 1;
  61         memcpy(buf, p, len);
  62         buf[len] = '\0';
  63     }
  64     *pp = p1;
  65     return 0;
  66 }
  67
  68 /* slirp network adapter */
  69
  70 #define SLIRP_CFG_HOSTFWD 1
  71
  72 struct slirp_config_str {
  73     struct slirp_config_str *next;
  74     int flags;
  75     char str[1024];
  76 };
  77
  78 struct GuestFwd {
  79     CharBackend hd;
  80     struct in_addr server;
  81     int port;
  82     Slirp *slirp;
  83 };
  84
  85 typedef struct SlirpState {
  86     NetClientState nc;
  87     QTAILQ_ENTRY(SlirpState) entry;
  88     Slirp *slirp;
  89     Notifier exit_notifier;
  90 #ifndef _WIN32
  91     gchar *smb_dir;
  92 #endif
  93     GSList *fwd;
  94 } SlirpState;
  95
  96 static struct slirp_config_str *slirp_configs;
  97 static QTAILQ_HEAD(, SlirpState) slirp_stacks =
  98     QTAILQ_HEAD_INITIALIZER(slirp_stacks);
  99
 100 static int slirp_hostfwd(SlirpState *s, const char *redir_str, Error **errp);
 101 static int slirp_guestfwd(SlirpState *s, const char *config_str, Error **errp);
 102
 103 #ifndef _WIN32
 104 static int slirp_smb(SlirpState *s, const char *exported_dir,
 105                      struct in_addr vserver_addr, Error **errp);
 106 static void slirp_smb_cleanup(SlirpState *s);
 107 #else
 108 static inline void slirp_smb_cleanup(SlirpState *s) { }
 109 #endif
 110
 111 static void net_slirp_output(void *opaque, const uint8_t *pkt, int pkt_len)
 112 {
 113     SlirpState *s = opaque;
 114
 115     qemu_send_packet(&s->nc, pkt, pkt_len);
 116 }
 117
 118 static ssize_t net_slirp_receive(NetClientState *nc, const uint8_t *buf, size_t size)
 119 {
 120     SlirpState *s = DO_UPCAST(SlirpState, nc, nc);
 121
 122     slirp_input(s->slirp, buf, size);
 123
 124     return size;
 125 }
 126
 127 static void slirp_smb_exit(Notifier *n, void *data)
 128 {
 129     SlirpState *s = container_of(n, SlirpState, exit_notifier);
 130     slirp_smb_cleanup(s);
 131 }
 132
 133 static void slirp_free_fwd(gpointer data)
 134 {
 135     struct GuestFwd *fwd = data;
 136
 137     qemu_chr_fe_deinit(&fwd->hd, true);
 138     g_free(data);
 139 }
 140
 141 static void net_slirp_cleanup(NetClientState *nc)
 142 {
 143     SlirpState *s = DO_UPCAST(SlirpState, nc, nc);
 144
 145     g_slist_free_full(s->fwd, slirp_free_fwd);
 146     slirp_cleanup(s->slirp);
 147     if (s->exit_notifier.notify) {
 148         qemu_remove_exit_notifier(&s->exit_notifier);
 149     }
 150     slirp_smb_cleanup(s);
 151     QTAILQ_REMOVE(&slirp_stacks, s, entry);
 152 }
 153
 154 static NetClientInfo net_slirp_info = {
 155     .type = NET_CLIENT_DRIVER_USER,
 156     .size = sizeof(SlirpState),
 157     .receive = net_slirp_receive,
 158     .cleanup = net_slirp_cleanup,
 159 };
 160
 161 static void net_slirp_guest_error(const char *msg)
 162 {
 163     qemu_log_mask(LOG_GUEST_ERROR, "%s", msg);
 164 }
 165
 166 static int64_t net_slirp_clock_get_ns(void)
 167 {
 168     return qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
 169 }
 170
 171 static void *net_slirp_timer_new(SlirpTimerCb cb, void *opaque)
 172 {
 173     return timer_new_full(NULL, QEMU_CLOCK_VIRTUAL,
 174                           SCALE_MS, QEMU_TIMER_ATTR_EXTERNAL,
 175                           cb, opaque);
 176 }
 177
 178 static void net_slirp_timer_free(void *timer)
 179 {
 180     timer_del(timer);
 181     timer_free(timer);
 182 }
 183
 184 static void net_slirp_timer_mod(void *timer, int64_t expire_timer)
 185 {
 186     timer_mod(timer, expire_timer);
 187 }
 188
 189 static const SlirpCb slirp_cb = {
 190     .output = net_slirp_output,
 191     .guest_error = net_slirp_guest_error,
 192     .clock_get_ns = net_slirp_clock_get_ns,
 193     .timer_new = net_slirp_timer_new,
 194     .timer_free = net_slirp_timer_free,
 195     .timer_mod = net_slirp_timer_mod,
 196 };
 197
 198 static int net_slirp_init(NetClientState *peer, const char *model,
 199                           const char *name, int restricted,
 200                           bool ipv4, const char *vnetwork, const char *vhost,
 201                           bool ipv6, const char *vprefix6, int vprefix6_len,
 202                           const char *vhost6,
 203                           const char *vhostname, const char *tftp_export,
 204                           const char *bootfile, const char *vdhcp_start,
 205                           const char *vnameserver, const char *vnameserver6,
 206                           const char *smb_export, const char *vsmbserver,
 207                           const char **dnssearch, const char *vdomainname,
 208                           const char *tftp_server_name,
 209                           Error **errp)
 210 {
 211     /* default settings according to historic slirp */
 212     struct in_addr net  = { .s_addr = htonl(0x0a000200) }; /* 10.0.2.0 */
 213     struct in_addr mask = { .s_addr = htonl(0xffffff00) }; /* 255.255.255.0 */
 214     struct in_addr host = { .s_addr = htonl(0x0a000202) }; /* 10.0.2.2 */
 215     struct in_addr dhcp = { .s_addr = htonl(0x0a00020f) }; /* 10.0.2.15 */
 216     struct in_addr dns  = { .s_addr = htonl(0x0a000203) }; /* 10.0.2.3 */
 217     struct in6_addr ip6_prefix;
 218     struct in6_addr ip6_host;
 219     struct in6_addr ip6_dns;
 220 #ifndef _WIN32
 221     struct in_addr smbsrv = { .s_addr = 0 };
 222 #endif
 223     NetClientState *nc;
 224     SlirpState *s;
 225     char buf[20];
 226     uint32_t addr;
 227     int shift;
 228     char *end;
 229     struct slirp_config_str *config;
 230
 231     if (!ipv4 && (vnetwork || vhost || vnameserver)) {
 232         error_setg(errp, "IPv4 disabled but netmask/host/dns provided");
 233         return -1;
 234     }
 235
 236     if (!ipv6 && (vprefix6 || vhost6 || vnameserver6)) {
 237         error_setg(errp, "IPv6 disabled but prefix/host6/dns6 provided");
 238         return -1;
 239     }
 240
 241     if (!ipv4 && !ipv6) {
 242         /* It doesn't make sense to disable both */
 243         error_setg(errp, "IPv4 and IPv6 disabled");
 244         return -1;
 245     }
 246
 247     if (vnetwork) {
 248         if (get_str_sep(buf, sizeof(buf), &vnetwork, '/') < 0) {
 249             if (!inet_aton(vnetwork, &net)) {
 250                 error_setg(errp, "Failed to parse netmask");
 251                 return -1;
 252             }
 253             addr = ntohl(net.s_addr);
 254             if (!(addr & 0x80000000)) {
 255                 mask.s_addr = htonl(0xff000000); /* class A */
 256             } else if ((addr & 0xfff00000) == 0xac100000) {
 257                 mask.s_addr = htonl(0xfff00000); /* priv. 172.16.0.0/12 */
 258             } else if ((addr & 0xc0000000) == 0x80000000) {
 259                 mask.s_addr = htonl(0xffff0000); /* class B */
 260             } else if ((addr & 0xffff0000) == 0xc0a80000) {
 261                 mask.s_addr = htonl(0xffff0000); /* priv. 192.168.0.0/16 */
 262             } else if ((addr & 0xffff0000) == 0xc6120000) {
 263                 mask.s_addr = htonl(0xfffe0000); /* tests 198.18.0.0/15 */
 264             } else if ((addr & 0xe0000000) == 0xe0000000) {
 265                 mask.s_addr = htonl(0xffffff00); /* class C */
 266             } else {
 267                 mask.s_addr = htonl(0xfffffff0); /* multicast/reserved */
 268             }
 269         } else {
 270             if (!inet_aton(buf, &net)) {
 271                 error_setg(errp, "Failed to parse netmask");
 272                 return -1;
 273             }
 274             shift = strtol(vnetwork, &end, 10);
 275             if (*end != '\0') {
 276                 if (!inet_aton(vnetwork, &mask)) {
 277                     error_setg(errp,
 278                                "Failed to parse netmask (trailing chars)");
 279                     return -1;
 280                 }
 281             } else if (shift < 4 || shift > 32) {
 282                 error_setg(errp,
 283                            "Invalid netmask provided (must be in range 4-32)");
 284                 return -1;
 285             } else {
 286                 mask.s_addr = htonl(0xffffffff << (32 - shift));
 287             }
 288         }
 289         net.s_addr &= mask.s_addr;
 290         host.s_addr = net.s_addr | (htonl(0x0202) & ~mask.s_addr);
 291         dhcp.s_addr = net.s_addr | (htonl(0x020f) & ~mask.s_addr);
 292         dns.s_addr  = net.s_addr | (htonl(0x0203) & ~mask.s_addr);
 293     }
 294
 295     if (vhost && !inet_aton(vhost, &host)) {
 296         error_setg(errp, "Failed to parse host");
 297         return -1;
 298     }
 299     if ((host.s_addr & mask.s_addr) != net.s_addr) {
 300         error_setg(errp, "Host doesn't belong to network");
 301         return -1;
 302     }
 303
 304     if (vnameserver && !inet_aton(vnameserver, &dns)) {
 305         error_setg(errp, "Failed to parse DNS");
 306         return -1;
 307     }
 308     if ((dns.s_addr & mask.s_addr) != net.s_addr) {
 309         error_setg(errp, "DNS doesn't belong to network");
 310         return -1;
 311     }
 312     if (dns.s_addr == host.s_addr) {
 313         error_setg(errp, "DNS must be different from host");
 314         return -1;
 315     }
 316
 317     if (vdhcp_start && !inet_aton(vdhcp_start, &dhcp)) {
 318         error_setg(errp, "Failed to parse DHCP start address");
 319         return -1;
 320     }
 321     if ((dhcp.s_addr & mask.s_addr) != net.s_addr) {
 322         error_setg(errp, "DHCP doesn't belong to network");
 323         return -1;
 324     }
 325     if (dhcp.s_addr == host.s_addr || dhcp.s_addr == dns.s_addr) {
 326         error_setg(errp, "DNS must be different from host and DNS");
 327         return -1;
 328     }
 329
 330 #ifndef _WIN32
 331     if (vsmbserver && !inet_aton(vsmbserver, &smbsrv)) {
 332         error_setg(errp, "Failed to parse SMB address");
 333         return -1;
 334     }
 335 #endif
 336
 337     if (!vprefix6) {
 338         vprefix6 = "fec0::";
 339     }
 340     if (!inet_pton(AF_INET6, vprefix6, &ip6_prefix)) {
 341         error_setg(errp, "Failed to parse IPv6 prefix");
 342         return -1;
 343     }
 344
 345     if (!vprefix6_len) {
 346         vprefix6_len = 64;
 347     }
 348     if (vprefix6_len < 0 || vprefix6_len > 126) {
 349         error_setg(errp,
 350                    "Invalid prefix provided (prefix len must be in range 0-126");
 351         return -1;
 352     }
 353
 354     if (vhost6) {
 355         if (!inet_pton(AF_INET6, vhost6, &ip6_host)) {
 356             error_setg(errp, "Failed to parse IPv6 host");
 357             return -1;
 358         }
 359         if (!in6_equal_net(&ip6_prefix, &ip6_host, vprefix6_len)) {
 360             error_setg(errp, "IPv6 Host doesn't belong to network");
 361             return -1;
 362         }
 363     } else {
 364         ip6_host = ip6_prefix;
 365         ip6_host.s6_addr[15] |= 2;
 366     }
 367
 368     if (vnameserver6) {
 369         if (!inet_pton(AF_INET6, vnameserver6, &ip6_dns)) {
 370             error_setg(errp, "Failed to parse IPv6 DNS");
 371             return -1;
 372         }
 373         if (!in6_equal_net(&ip6_prefix, &ip6_dns, vprefix6_len)) {
 374             error_setg(errp, "IPv6 DNS doesn't belong to network");
 375             return -1;
 376         }
 377     } else {
 378         ip6_dns = ip6_prefix;
 379         ip6_dns.s6_addr[15] |= 3;
 380     }
 381
 382     if (vdomainname && !*vdomainname) {
 383         error_setg(errp, "'domainname' parameter cannot be empty");
 384         return -1;
 385     }
 386
 387     if (vdomainname && strlen(vdomainname) > 255) {
 388         error_setg(errp, "'domainname' parameter cannot exceed 255 bytes");
 389         return -1;
 390     }
 391
 392     if (vhostname && strlen(vhostname) > 255) {
 393         error_setg(errp, "'vhostname' parameter cannot exceed 255 bytes");
 394         return -1;
 395     }
 396
 397     if (tftp_server_name && strlen(tftp_server_name) > 255) {
 398         error_setg(errp, "'tftp-server-name' parameter cannot exceed 255 bytes");
 399         return -1;
 400     }
 401
 402     nc = qemu_new_net_client(&net_slirp_info, peer, model, name);
 403
 404     snprintf(nc->info_str, sizeof(nc->info_str),
 405              "net=%s,restrict=%s", inet_ntoa(net),
 406              restricted ? "on" : "off");
 407
 408     s = DO_UPCAST(SlirpState, nc, nc);
 409
 410     s->slirp = slirp_init(restricted, ipv4, net, mask, host,
 411                           ipv6, ip6_prefix, vprefix6_len, ip6_host,
 412                           vhostname, tftp_server_name,
 413                           tftp_export, bootfile, dhcp,
 414                           dns, ip6_dns, dnssearch, vdomainname,
 415                           &slirp_cb, s);
 416     QTAILQ_INSERT_TAIL(&slirp_stacks, s, entry);
 417
 418     for (config = slirp_configs; config; config = config->next) {
 419         if (config->flags & SLIRP_CFG_HOSTFWD) {
 420             if (slirp_hostfwd(s, config->str, errp) < 0) {
 421                 goto error;
 422             }
 423         } else {
 424             if (slirp_guestfwd(s, config->str, errp) < 0) {
 425                 goto error;
 426             }
 427         }
 428     }
 429 #ifndef _WIN32
 430     if (smb_export) {
 431         if (slirp_smb(s, smb_export, smbsrv, errp) < 0) {
 432             goto error;
 433         }
 434     }
 435 #endif
 436
 437     s->exit_notifier.notify = slirp_smb_exit;
 438     qemu_add_exit_notifier(&s->exit_notifier);
 439     return 0;
 440
 441 error:
 442     qemu_del_net_client(nc);
 443     return -1;
 444 }
 445
 446 static SlirpState *slirp_lookup(Monitor *mon, const char *hub_id,
 447                                 const char *name)
 448 {
 449     if (name) {
 450         NetClientState *nc;
 451         if (hub_id) {
 452             nc = net_hub_find_client_by_name(strtol(hub_id, NULL, 0), name);
 453             if (!nc) {
 454                 monitor_printf(mon, "unrecognized (hub-id, stackname) pair\n");
 455                 return NULL;
 456             }
 457             warn_report("Using 'hub-id' is deprecated, specify the netdev id "
 458                         "directly instead");
 459         } else {
 460             nc = qemu_find_netdev(name);
 461             if (!nc) {
 462                 monitor_printf(mon, "unrecognized netdev id '%s'\n", name);
 463                 return NULL;
 464             }
 465         }
 466         if (strcmp(nc->model, "user")) {
 467             monitor_printf(mon, "invalid device specified\n");
 468             return NULL;
 469         }
 470         return DO_UPCAST(SlirpState, nc, nc);
 471     } else {
 472         if (QTAILQ_EMPTY(&slirp_stacks)) {
 473             monitor_printf(mon, "user mode network stack not in use\n");
 474             return NULL;
 475         }
 476         return QTAILQ_FIRST(&slirp_stacks);
 477     }
 478 }
 479
 480 void hmp_hostfwd_remove(Monitor *mon, const QDict *qdict)
 481 {
 482     struct in_addr host_addr = { .s_addr = INADDR_ANY };
 483     int host_port;
 484     char buf[256];
 485     const char *src_str, *p;
 486     SlirpState *s;
 487     int is_udp = 0;
 488     int err;
 489     const char *arg1 = qdict_get_str(qdict, "arg1");
 490     const char *arg2 = qdict_get_try_str(qdict, "arg2");
 491     const char *arg3 = qdict_get_try_str(qdict, "arg3");
 492
 493     if (arg3) {
 494         s = slirp_lookup(mon, arg1, arg2);
 495         src_str = arg3;
 496     } else if (arg2) {
 497         s = slirp_lookup(mon, NULL, arg1);
 498         src_str = arg2;
 499     } else {
 500         s = slirp_lookup(mon, NULL, NULL);
 501         src_str = arg1;
 502     }
 503     if (!s) {
 504         return;
 505     }
 506
 507     p = src_str;
 508     if (!p || get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 509         goto fail_syntax;
 510     }
 511
 512     if (!strcmp(buf, "tcp") || buf[0] == '\0') {
 513         is_udp = 0;
 514     } else if (!strcmp(buf, "udp")) {
 515         is_udp = 1;
 516     } else {
 517         goto fail_syntax;
 518     }
 519
 520     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 521         goto fail_syntax;
 522     }
 523     if (buf[0] != '\0' && !inet_aton(buf, &host_addr)) {
 524         goto fail_syntax;
 525     }
 526
 527     if (qemu_strtoi(p, NULL, 10, &host_port)) {
 528         goto fail_syntax;
 529     }
 530
 531     err = slirp_remove_hostfwd(s->slirp, is_udp, host_addr, host_port);
 532
 533     monitor_printf(mon, "host forwarding rule for %s %s\n", src_str,
 534                    err ? "not found" : "removed");
 535     return;
 536
 537  fail_syntax:
 538     monitor_printf(mon, "invalid format\n");
 539 }
 540
 541 static int slirp_hostfwd(SlirpState *s, const char *redir_str, Error **errp)
 542 {
 543     struct in_addr host_addr = { .s_addr = INADDR_ANY };
 544     struct in_addr guest_addr = { .s_addr = 0 };
 545     int host_port, guest_port;
 546     const char *p;
 547     char buf[256];
 548     int is_udp;
 549     char *end;
 550     const char *fail_reason = "Unknown reason";
 551
 552     p = redir_str;
 553     if (!p || get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 554         fail_reason = "No : separators";
 555         goto fail_syntax;
 556     }
 557     if (!strcmp(buf, "tcp") || buf[0] == '\0') {
 558         is_udp = 0;
 559     } else if (!strcmp(buf, "udp")) {
 560         is_udp = 1;
 561     } else {
 562         fail_reason = "Bad protocol name";
 563         goto fail_syntax;
 564     }
 565
 566     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 567         fail_reason = "Missing : separator";
 568         goto fail_syntax;
 569     }
 570     if (buf[0] != '\0' && !inet_aton(buf, &host_addr)) {
 571         fail_reason = "Bad host address";
 572         goto fail_syntax;
 573     }
 574
 575     if (get_str_sep(buf, sizeof(buf), &p, '-') < 0) {
 576         fail_reason = "Bad host port separator";
 577         goto fail_syntax;
 578     }
 579     host_port = strtol(buf, &end, 0);
 580     if (*end != '\0' || host_port < 0 || host_port > 65535) {
 581         fail_reason = "Bad host port";
 582         goto fail_syntax;
 583     }
 584
 585     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 586         fail_reason = "Missing guest address";
 587         goto fail_syntax;
 588     }
 589     if (buf[0] != '\0' && !inet_aton(buf, &guest_addr)) {
 590         fail_reason = "Bad guest address";
 591         goto fail_syntax;
 592     }
 593
 594     guest_port = strtol(p, &end, 0);
 595     if (*end != '\0' || guest_port < 1 || guest_port > 65535) {
 596         fail_reason = "Bad guest port";
 597         goto fail_syntax;
 598     }
 599
 600     if (slirp_add_hostfwd(s->slirp, is_udp, host_addr, host_port, guest_addr,
 601                           guest_port) < 0) {
 602         error_setg(errp, "Could not set up host forwarding rule '%s'",
 603                    redir_str);
 604         return -1;
 605     }
 606     return 0;
 607
 608  fail_syntax:
 609     error_setg(errp, "Invalid host forwarding rule '%s' (%s)", redir_str,
 610                fail_reason);
 611     return -1;
 612 }
 613
 614 void hmp_hostfwd_add(Monitor *mon, const QDict *qdict)
 615 {
 616     const char *redir_str;
 617     SlirpState *s;
 618     const char *arg1 = qdict_get_str(qdict, "arg1");
 619     const char *arg2 = qdict_get_try_str(qdict, "arg2");
 620     const char *arg3 = qdict_get_try_str(qdict, "arg3");
 621
 622     if (arg3) {
 623         s = slirp_lookup(mon, arg1, arg2);
 624         redir_str = arg3;
 625     } else if (arg2) {
 626         s = slirp_lookup(mon, NULL, arg1);
 627         redir_str = arg2;
 628     } else {
 629         s = slirp_lookup(mon, NULL, NULL);
 630         redir_str = arg1;
 631     }
 632     if (s) {
 633         Error *err = NULL;
 634         if (slirp_hostfwd(s, redir_str, &err) < 0) {
 635             error_report_err(err);
 636         }
 637     }
 638
 639 }
 640
 641 #ifndef _WIN32
 642
 643 /* automatic user mode samba server configuration */
 644 static void slirp_smb_cleanup(SlirpState *s)
 645 {
 646     int ret;
 647
 648     if (s->smb_dir) {
 649         gchar *cmd = g_strdup_printf("rm -rf %s", s->smb_dir);
 650         ret = system(cmd);
 651         if (ret == -1 || !WIFEXITED(ret)) {
 652             error_report("'%s' failed.", cmd);
 653         } else if (WEXITSTATUS(ret)) {
 654             error_report("'%s' failed. Error code: %d",
 655                          cmd, WEXITSTATUS(ret));
 656         }
 657         g_free(cmd);
 658         g_free(s->smb_dir);
 659         s->smb_dir = NULL;
 660     }
 661 }
 662
 663 static int slirp_smb(SlirpState* s, const char *exported_dir,
 664                      struct in_addr vserver_addr, Error **errp)
 665 {
 666     char *smb_conf;
 667     char *smb_cmdline;
 668     struct passwd *passwd;
 669     FILE *f;
 670
 671     passwd = getpwuid(geteuid());
 672     if (!passwd) {
 673         error_setg(errp, "Failed to retrieve user name");
 674         return -1;
 675     }
 676
 677     if (access(CONFIG_SMBD_COMMAND, F_OK)) {
 678         error_setg(errp, "Could not find '%s', please install it",
 679                    CONFIG_SMBD_COMMAND);
 680         return -1;
 681     }
 682
 683     if (access(exported_dir, R_OK | X_OK)) {
 684         error_setg(errp, "Error accessing shared directory '%s': %s",
 685                    exported_dir, strerror(errno));
 686         return -1;
 687     }
 688
 689     s->smb_dir = g_dir_make_tmp("qemu-smb.XXXXXX", NULL);
 690     if (!s->smb_dir) {
 691         error_setg(errp, "Could not create samba server dir");
 692         return -1;
 693     }
 694     smb_conf = g_strdup_printf("%s/%s", s->smb_dir, "smb.conf");
 695
 696     f = fopen(smb_conf, "w");
 697     if (!f) {
 698         slirp_smb_cleanup(s);
 699         error_setg(errp,
 700                    "Could not create samba server configuration file '%s'",
 701                     smb_conf);
 702         g_free(smb_conf);
 703         return -1;
 704     }
 705     fprintf(f,
 706             "[global]\n"
 707             "private dir=%s\n"
 708             "interfaces=127.0.0.1\n"
 709             "bind interfaces only=yes\n"
 710             "pid directory=%s\n"
 711             "lock directory=%s\n"
 712             "state directory=%s\n"
 713             "cache directory=%s\n"
 714             "ncalrpc dir=%s/ncalrpc\n"
 715             "log file=%s/log.smbd\n"
 716             "smb passwd file=%s/smbpasswd\n"
 717             "security = user\n"
 718             "map to guest = Bad User\n"
 719             "load printers = no\n"
 720             "printing = bsd\n"
 721             "disable spoolss = yes\n"
 722             "usershare max shares = 0\n"
 723             "[qemu]\n"
 724             "path=%s\n"
 725             "read only=no\n"
 726             "guest ok=yes\n"
 727             "force user=%s\n",
 728             s->smb_dir,
 729             s->smb_dir,
 730             s->smb_dir,
 731             s->smb_dir,
 732             s->smb_dir,
 733             s->smb_dir,
 734             s->smb_dir,
 735             s->smb_dir,
 736             exported_dir,
 737             passwd->pw_name
 738             );
 739     fclose(f);
 740
 741     smb_cmdline = g_strdup_printf("%s -l %s -s %s",
 742              CONFIG_SMBD_COMMAND, s->smb_dir, smb_conf);
 743     g_free(smb_conf);
 744
 745     if (slirp_add_exec(s->slirp, smb_cmdline, &vserver_addr, 139) < 0 ||
 746         slirp_add_exec(s->slirp, smb_cmdline, &vserver_addr, 445) < 0) {
 747         slirp_smb_cleanup(s);
 748         g_free(smb_cmdline);
 749         error_setg(errp, "Conflicting/invalid smbserver address");
 750         return -1;
 751     }
 752     g_free(smb_cmdline);
 753     return 0;
 754 }
 755
 756 #endif /* !defined(_WIN32) */
 757
 758 static int guestfwd_can_read(void *opaque)
 759 {
 760     struct GuestFwd *fwd = opaque;
 761     return slirp_socket_can_recv(fwd->slirp, fwd->server, fwd->port);
 762 }
 763
 764 static void guestfwd_read(void *opaque, const uint8_t *buf, int size)
 765 {
 766     struct GuestFwd *fwd = opaque;
 767     slirp_socket_recv(fwd->slirp, fwd->server, fwd->port, buf, size);
 768 }
 769
 770 static int guestfwd_write(const void *buf, size_t len, void *chr)
 771 {
 772     return qemu_chr_fe_write_all(chr, buf, len);
 773 }
 774
 775 static int slirp_guestfwd(SlirpState *s, const char *config_str, Error **errp)
 776 {
 777     struct in_addr server = { .s_addr = 0 };
 778     struct GuestFwd *fwd;
 779     const char *p;
 780     char buf[128];
 781     char *end;
 782     int port;
 783
 784     p = config_str;
 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     port = strtol(buf, &end, 10);
 801     if (*end != '\0' || port < 1 || port > 65535) {
 802         goto fail_syntax;
 803     }
 804
 805     snprintf(buf, sizeof(buf), "guestfwd.tcp.%d", port);
 806
 807     if (g_str_has_prefix(p, "cmd:")) {
 808         if (slirp_add_exec(s->slirp, &p[4], &server, port) < 0) {
 809             error_setg(errp, "Conflicting/invalid host:port in guest "
 810                        "forwarding rule '%s'", config_str);
 811             return -1;
 812         }
 813     } else {
 814         Error *err = NULL;
 815         /*
 816          * FIXME: sure we want to support implicit
 817          * muxed monitors here?
 818          */
 819         Chardev *chr = qemu_chr_new_mux_mon(buf, p);
 820
 821         if (!chr) {
 822             error_setg(errp, "Could not open guest forwarding device '%s'",
 823                        buf);
 824             return -1;
 825         }
 826
 827         fwd = g_new(struct GuestFwd, 1);
 828         qemu_chr_fe_init(&fwd->hd, chr, &err);
 829         if (err) {
 830             error_propagate(errp, err);
 831             object_unparent(OBJECT(chr));
 832             g_free(fwd);
 833             return -1;
 834         }
 835
 836         if (slirp_add_guestfwd(s->slirp, guestfwd_write, &fwd->hd,
 837                                &server, port) < 0) {
 838             error_setg(errp, "Conflicting/invalid host:port in guest "
 839                        "forwarding rule '%s'", config_str);
 840             qemu_chr_fe_deinit(&fwd->hd, true);
 841             g_free(fwd);
 842             return -1;
 843         }
 844         fwd->server = server;
 845         fwd->port = port;
 846         fwd->slirp = s->slirp;
 847
 848         qemu_chr_fe_set_handlers(&fwd->hd, guestfwd_can_read, guestfwd_read,
 849                                  NULL, NULL, fwd, NULL, true);
 850         s->fwd = g_slist_append(s->fwd, fwd);
 851     }
 852     return 0;
 853
 854  fail_syntax:
 855     error_setg(errp, "Invalid guest forwarding rule '%s'", config_str);
 856     return -1;
 857 }
 858
 859 void hmp_info_usernet(Monitor *mon, const QDict *qdict)
 860 {
 861     SlirpState *s;
 862
 863     QTAILQ_FOREACH(s, &slirp_stacks, entry) {
 864         int id;
 865         bool got_hub_id = net_hub_id_for_client(&s->nc, &id) == 0;
 866         char *info = slirp_connection_info(s->slirp);
 867         monitor_printf(mon, "Hub %d (%s):\n%s",
 868                        got_hub_id ? id : -1,
 869                        s->nc.name, info);
 870         g_free(info);
 871     }
 872 }
 873
 874 static void
 875 net_init_slirp_configs(const StringList *fwd, int flags)
 876 {
 877     while (fwd) {
 878         struct slirp_config_str *config;
 879
 880         config = g_malloc0(sizeof(*config));
 881         pstrcpy(config->str, sizeof(config->str), fwd->value->str);
 882         config->flags = flags;
 883         config->next = slirp_configs;
 884         slirp_configs = config;
 885
 886         fwd = fwd->next;
 887     }
 888 }
 889
 890 static const char **slirp_dnssearch(const StringList *dnsname)
 891 {
 892     const StringList *c = dnsname;
 893     size_t i = 0, num_opts = 0;
 894     const char **ret;
 895
 896     while (c) {
 897         num_opts++;
 898         c = c->next;
 899     }
 900
 901     if (num_opts == 0) {
 902         return NULL;
 903     }
 904
 905     ret = g_malloc((num_opts + 1) * sizeof(*ret));
 906     c = dnsname;
 907     while (c) {
 908         ret[i++] = c->value->str;
 909         c = c->next;
 910     }
 911     ret[i] = NULL;
 912     return ret;
 913 }
 914
 915 int net_init_slirp(const Netdev *netdev, const char *name,
 916                    NetClientState *peer, Error **errp)
 917 {
 918     struct slirp_config_str *config;
 919     char *vnet;
 920     int ret;
 921     const NetdevUserOptions *user;
 922     const char **dnssearch;
 923     bool ipv4 = true, ipv6 = true;
 924
 925     assert(netdev->type == NET_CLIENT_DRIVER_USER);
 926     user = &netdev->u.user;
 927
 928     if ((user->has_ipv6 && user->ipv6 && !user->has_ipv4) ||
 929         (user->has_ipv4 && !user->ipv4)) {
 930         ipv4 = 0;
 931     }
 932     if ((user->has_ipv4 && user->ipv4 && !user->has_ipv6) ||
 933         (user->has_ipv6 && !user->ipv6)) {
 934         ipv6 = 0;
 935     }
 936
 937     vnet = user->has_net ? g_strdup(user->net) :
 938            user->has_ip  ? g_strdup_printf("%s/24", user->ip) :
 939            NULL;
 940
 941     dnssearch = slirp_dnssearch(user->dnssearch);
 942
 943     /* all optional fields are initialized to "all bits zero" */
 944
 945     net_init_slirp_configs(user->hostfwd, SLIRP_CFG_HOSTFWD);
 946     net_init_slirp_configs(user->guestfwd, 0);
 947
 948     ret = net_slirp_init(peer, "user", name, user->q_restrict,
 949                          ipv4, vnet, user->host,
 950                          ipv6, user->ipv6_prefix, user->ipv6_prefixlen,
 951                          user->ipv6_host, user->hostname, user->tftp,
 952                          user->bootfile, user->dhcpstart,
 953                          user->dns, user->ipv6_dns, user->smb,
 954                          user->smbserver, dnssearch, user->domainname,
 955                          user->tftp_server_name, errp);
 956
 957     while (slirp_configs) {
 958         config = slirp_configs;
 959         slirp_configs = config->next;
 960         g_free(config);
 961     }
 962
 963     g_free(vnet);
 964     g_free(dnssearch);
 965
 966     return ret;
 967 }