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 void net_slirp_register_poll_fd(int fd)
 190 {
 191     qemu_fd_register(fd);
 192 }
 193
 194 static void net_slirp_unregister_poll_fd(int fd)
 195 {
 196     /* no qemu_fd_unregister */
 197 }
 198
 199 static const SlirpCb slirp_cb = {
 200     .output = net_slirp_output,
 201     .guest_error = net_slirp_guest_error,
 202     .clock_get_ns = net_slirp_clock_get_ns,
 203     .timer_new = net_slirp_timer_new,
 204     .timer_free = net_slirp_timer_free,
 205     .timer_mod = net_slirp_timer_mod,
 206     .register_poll_fd = net_slirp_register_poll_fd,
 207     .unregister_poll_fd = net_slirp_unregister_poll_fd,
 208     .notify = qemu_notify_event,
 209 };
 210
 211 static int net_slirp_init(NetClientState *peer, const char *model,
 212                           const char *name, int restricted,
 213                           bool ipv4, const char *vnetwork, const char *vhost,
 214                           bool ipv6, const char *vprefix6, int vprefix6_len,
 215                           const char *vhost6,
 216                           const char *vhostname, const char *tftp_export,
 217                           const char *bootfile, const char *vdhcp_start,
 218                           const char *vnameserver, const char *vnameserver6,
 219                           const char *smb_export, const char *vsmbserver,
 220                           const char **dnssearch, const char *vdomainname,
 221                           const char *tftp_server_name,
 222                           Error **errp)
 223 {
 224     /* default settings according to historic slirp */
 225     struct in_addr net  = { .s_addr = htonl(0x0a000200) }; /* 10.0.2.0 */
 226     struct in_addr mask = { .s_addr = htonl(0xffffff00) }; /* 255.255.255.0 */
 227     struct in_addr host = { .s_addr = htonl(0x0a000202) }; /* 10.0.2.2 */
 228     struct in_addr dhcp = { .s_addr = htonl(0x0a00020f) }; /* 10.0.2.15 */
 229     struct in_addr dns  = { .s_addr = htonl(0x0a000203) }; /* 10.0.2.3 */
 230     struct in6_addr ip6_prefix;
 231     struct in6_addr ip6_host;
 232     struct in6_addr ip6_dns;
 233 #ifndef _WIN32
 234     struct in_addr smbsrv = { .s_addr = 0 };
 235 #endif
 236     NetClientState *nc;
 237     SlirpState *s;
 238     char buf[20];
 239     uint32_t addr;
 240     int shift;
 241     char *end;
 242     struct slirp_config_str *config;
 243
 244     if (!ipv4 && (vnetwork || vhost || vnameserver)) {
 245         error_setg(errp, "IPv4 disabled but netmask/host/dns provided");
 246         return -1;
 247     }
 248
 249     if (!ipv6 && (vprefix6 || vhost6 || vnameserver6)) {
 250         error_setg(errp, "IPv6 disabled but prefix/host6/dns6 provided");
 251         return -1;
 252     }
 253
 254     if (!ipv4 && !ipv6) {
 255         /* It doesn't make sense to disable both */
 256         error_setg(errp, "IPv4 and IPv6 disabled");
 257         return -1;
 258     }
 259
 260     if (vnetwork) {
 261         if (get_str_sep(buf, sizeof(buf), &vnetwork, '/') < 0) {
 262             if (!inet_aton(vnetwork, &net)) {
 263                 error_setg(errp, "Failed to parse netmask");
 264                 return -1;
 265             }
 266             addr = ntohl(net.s_addr);
 267             if (!(addr & 0x80000000)) {
 268                 mask.s_addr = htonl(0xff000000); /* class A */
 269             } else if ((addr & 0xfff00000) == 0xac100000) {
 270                 mask.s_addr = htonl(0xfff00000); /* priv. 172.16.0.0/12 */
 271             } else if ((addr & 0xc0000000) == 0x80000000) {
 272                 mask.s_addr = htonl(0xffff0000); /* class B */
 273             } else if ((addr & 0xffff0000) == 0xc0a80000) {
 274                 mask.s_addr = htonl(0xffff0000); /* priv. 192.168.0.0/16 */
 275             } else if ((addr & 0xffff0000) == 0xc6120000) {
 276                 mask.s_addr = htonl(0xfffe0000); /* tests 198.18.0.0/15 */
 277             } else if ((addr & 0xe0000000) == 0xe0000000) {
 278                 mask.s_addr = htonl(0xffffff00); /* class C */
 279             } else {
 280                 mask.s_addr = htonl(0xfffffff0); /* multicast/reserved */
 281             }
 282         } else {
 283             if (!inet_aton(buf, &net)) {
 284                 error_setg(errp, "Failed to parse netmask");
 285                 return -1;
 286             }
 287             shift = strtol(vnetwork, &end, 10);
 288             if (*end != '\0') {
 289                 if (!inet_aton(vnetwork, &mask)) {
 290                     error_setg(errp,
 291                                "Failed to parse netmask (trailing chars)");
 292                     return -1;
 293                 }
 294             } else if (shift < 4 || shift > 32) {
 295                 error_setg(errp,
 296                            "Invalid netmask provided (must be in range 4-32)");
 297                 return -1;
 298             } else {
 299                 mask.s_addr = htonl(0xffffffff << (32 - shift));
 300             }
 301         }
 302         net.s_addr &= mask.s_addr;
 303         host.s_addr = net.s_addr | (htonl(0x0202) & ~mask.s_addr);
 304         dhcp.s_addr = net.s_addr | (htonl(0x020f) & ~mask.s_addr);
 305         dns.s_addr  = net.s_addr | (htonl(0x0203) & ~mask.s_addr);
 306     }
 307
 308     if (vhost && !inet_aton(vhost, &host)) {
 309         error_setg(errp, "Failed to parse host");
 310         return -1;
 311     }
 312     if ((host.s_addr & mask.s_addr) != net.s_addr) {
 313         error_setg(errp, "Host doesn't belong to network");
 314         return -1;
 315     }
 316
 317     if (vnameserver && !inet_aton(vnameserver, &dns)) {
 318         error_setg(errp, "Failed to parse DNS");
 319         return -1;
 320     }
 321     if ((dns.s_addr & mask.s_addr) != net.s_addr) {
 322         error_setg(errp, "DNS doesn't belong to network");
 323         return -1;
 324     }
 325     if (dns.s_addr == host.s_addr) {
 326         error_setg(errp, "DNS must be different from host");
 327         return -1;
 328     }
 329
 330     if (vdhcp_start && !inet_aton(vdhcp_start, &dhcp)) {
 331         error_setg(errp, "Failed to parse DHCP start address");
 332         return -1;
 333     }
 334     if ((dhcp.s_addr & mask.s_addr) != net.s_addr) {
 335         error_setg(errp, "DHCP doesn't belong to network");
 336         return -1;
 337     }
 338     if (dhcp.s_addr == host.s_addr || dhcp.s_addr == dns.s_addr) {
 339         error_setg(errp, "DNS must be different from host and DNS");
 340         return -1;
 341     }
 342
 343 #ifndef _WIN32
 344     if (vsmbserver && !inet_aton(vsmbserver, &smbsrv)) {
 345         error_setg(errp, "Failed to parse SMB address");
 346         return -1;
 347     }
 348 #endif
 349
 350     if (!vprefix6) {
 351         vprefix6 = "fec0::";
 352     }
 353     if (!inet_pton(AF_INET6, vprefix6, &ip6_prefix)) {
 354         error_setg(errp, "Failed to parse IPv6 prefix");
 355         return -1;
 356     }
 357
 358     if (!vprefix6_len) {
 359         vprefix6_len = 64;
 360     }
 361     if (vprefix6_len < 0 || vprefix6_len > 126) {
 362         error_setg(errp,
 363                    "Invalid prefix provided (prefix len must be in range 0-126");
 364         return -1;
 365     }
 366
 367     if (vhost6) {
 368         if (!inet_pton(AF_INET6, vhost6, &ip6_host)) {
 369             error_setg(errp, "Failed to parse IPv6 host");
 370             return -1;
 371         }
 372         if (!in6_equal_net(&ip6_prefix, &ip6_host, vprefix6_len)) {
 373             error_setg(errp, "IPv6 Host doesn't belong to network");
 374             return -1;
 375         }
 376     } else {
 377         ip6_host = ip6_prefix;
 378         ip6_host.s6_addr[15] |= 2;
 379     }
 380
 381     if (vnameserver6) {
 382         if (!inet_pton(AF_INET6, vnameserver6, &ip6_dns)) {
 383             error_setg(errp, "Failed to parse IPv6 DNS");
 384             return -1;
 385         }
 386         if (!in6_equal_net(&ip6_prefix, &ip6_dns, vprefix6_len)) {
 387             error_setg(errp, "IPv6 DNS doesn't belong to network");
 388             return -1;
 389         }
 390     } else {
 391         ip6_dns = ip6_prefix;
 392         ip6_dns.s6_addr[15] |= 3;
 393     }
 394
 395     if (vdomainname && !*vdomainname) {
 396         error_setg(errp, "'domainname' parameter cannot be empty");
 397         return -1;
 398     }
 399
 400     if (vdomainname && strlen(vdomainname) > 255) {
 401         error_setg(errp, "'domainname' parameter cannot exceed 255 bytes");
 402         return -1;
 403     }
 404
 405     if (vhostname && strlen(vhostname) > 255) {
 406         error_setg(errp, "'vhostname' parameter cannot exceed 255 bytes");
 407         return -1;
 408     }
 409
 410     if (tftp_server_name && strlen(tftp_server_name) > 255) {
 411         error_setg(errp, "'tftp-server-name' parameter cannot exceed 255 bytes");
 412         return -1;
 413     }
 414
 415     nc = qemu_new_net_client(&net_slirp_info, peer, model, name);
 416
 417     snprintf(nc->info_str, sizeof(nc->info_str),
 418              "net=%s,restrict=%s", inet_ntoa(net),
 419              restricted ? "on" : "off");
 420
 421     s = DO_UPCAST(SlirpState, nc, nc);
 422
 423     s->slirp = slirp_init(restricted, ipv4, net, mask, host,
 424                           ipv6, ip6_prefix, vprefix6_len, ip6_host,
 425                           vhostname, tftp_server_name,
 426                           tftp_export, bootfile, dhcp,
 427                           dns, ip6_dns, dnssearch, vdomainname,
 428                           &slirp_cb, s);
 429     QTAILQ_INSERT_TAIL(&slirp_stacks, s, entry);
 430
 431     for (config = slirp_configs; config; config = config->next) {
 432         if (config->flags & SLIRP_CFG_HOSTFWD) {
 433             if (slirp_hostfwd(s, config->str, errp) < 0) {
 434                 goto error;
 435             }
 436         } else {
 437             if (slirp_guestfwd(s, config->str, errp) < 0) {
 438                 goto error;
 439             }
 440         }
 441     }
 442 #ifndef _WIN32
 443     if (smb_export) {
 444         if (slirp_smb(s, smb_export, smbsrv, errp) < 0) {
 445             goto error;
 446         }
 447     }
 448 #endif
 449
 450     s->exit_notifier.notify = slirp_smb_exit;
 451     qemu_add_exit_notifier(&s->exit_notifier);
 452     return 0;
 453
 454 error:
 455     qemu_del_net_client(nc);
 456     return -1;
 457 }
 458
 459 static SlirpState *slirp_lookup(Monitor *mon, const char *hub_id,
 460                                 const char *name)
 461 {
 462     if (name) {
 463         NetClientState *nc;
 464         if (hub_id) {
 465             nc = net_hub_find_client_by_name(strtol(hub_id, NULL, 0), name);
 466             if (!nc) {
 467                 monitor_printf(mon, "unrecognized (hub-id, stackname) pair\n");
 468                 return NULL;
 469             }
 470             warn_report("Using 'hub-id' is deprecated, specify the netdev id "
 471                         "directly instead");
 472         } else {
 473             nc = qemu_find_netdev(name);
 474             if (!nc) {
 475                 monitor_printf(mon, "unrecognized netdev id '%s'\n", name);
 476                 return NULL;
 477             }
 478         }
 479         if (strcmp(nc->model, "user")) {
 480             monitor_printf(mon, "invalid device specified\n");
 481             return NULL;
 482         }
 483         return DO_UPCAST(SlirpState, nc, nc);
 484     } else {
 485         if (QTAILQ_EMPTY(&slirp_stacks)) {
 486             monitor_printf(mon, "user mode network stack not in use\n");
 487             return NULL;
 488         }
 489         return QTAILQ_FIRST(&slirp_stacks);
 490     }
 491 }
 492
 493 void hmp_hostfwd_remove(Monitor *mon, const QDict *qdict)
 494 {
 495     struct in_addr host_addr = { .s_addr = INADDR_ANY };
 496     int host_port;
 497     char buf[256];
 498     const char *src_str, *p;
 499     SlirpState *s;
 500     int is_udp = 0;
 501     int err;
 502     const char *arg1 = qdict_get_str(qdict, "arg1");
 503     const char *arg2 = qdict_get_try_str(qdict, "arg2");
 504     const char *arg3 = qdict_get_try_str(qdict, "arg3");
 505
 506     if (arg3) {
 507         s = slirp_lookup(mon, arg1, arg2);
 508         src_str = arg3;
 509     } else if (arg2) {
 510         s = slirp_lookup(mon, NULL, arg1);
 511         src_str = arg2;
 512     } else {
 513         s = slirp_lookup(mon, NULL, NULL);
 514         src_str = arg1;
 515     }
 516     if (!s) {
 517         return;
 518     }
 519
 520     p = src_str;
 521     if (!p || get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 522         goto fail_syntax;
 523     }
 524
 525     if (!strcmp(buf, "tcp") || buf[0] == '\0') {
 526         is_udp = 0;
 527     } else if (!strcmp(buf, "udp")) {
 528         is_udp = 1;
 529     } else {
 530         goto fail_syntax;
 531     }
 532
 533     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 534         goto fail_syntax;
 535     }
 536     if (buf[0] != '\0' && !inet_aton(buf, &host_addr)) {
 537         goto fail_syntax;
 538     }
 539
 540     if (qemu_strtoi(p, NULL, 10, &host_port)) {
 541         goto fail_syntax;
 542     }
 543
 544     err = slirp_remove_hostfwd(s->slirp, is_udp, host_addr, host_port);
 545
 546     monitor_printf(mon, "host forwarding rule for %s %s\n", src_str,
 547                    err ? "not found" : "removed");
 548     return;
 549
 550  fail_syntax:
 551     monitor_printf(mon, "invalid format\n");
 552 }
 553
 554 static int slirp_hostfwd(SlirpState *s, const char *redir_str, Error **errp)
 555 {
 556     struct in_addr host_addr = { .s_addr = INADDR_ANY };
 557     struct in_addr guest_addr = { .s_addr = 0 };
 558     int host_port, guest_port;
 559     const char *p;
 560     char buf[256];
 561     int is_udp;
 562     char *end;
 563     const char *fail_reason = "Unknown reason";
 564
 565     p = redir_str;
 566     if (!p || get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 567         fail_reason = "No : separators";
 568         goto fail_syntax;
 569     }
 570     if (!strcmp(buf, "tcp") || buf[0] == '\0') {
 571         is_udp = 0;
 572     } else if (!strcmp(buf, "udp")) {
 573         is_udp = 1;
 574     } else {
 575         fail_reason = "Bad protocol name";
 576         goto fail_syntax;
 577     }
 578
 579     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 580         fail_reason = "Missing : separator";
 581         goto fail_syntax;
 582     }
 583     if (buf[0] != '\0' && !inet_aton(buf, &host_addr)) {
 584         fail_reason = "Bad host address";
 585         goto fail_syntax;
 586     }
 587
 588     if (get_str_sep(buf, sizeof(buf), &p, '-') < 0) {
 589         fail_reason = "Bad host port separator";
 590         goto fail_syntax;
 591     }
 592     host_port = strtol(buf, &end, 0);
 593     if (*end != '\0' || host_port < 0 || host_port > 65535) {
 594         fail_reason = "Bad host port";
 595         goto fail_syntax;
 596     }
 597
 598     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 599         fail_reason = "Missing guest address";
 600         goto fail_syntax;
 601     }
 602     if (buf[0] != '\0' && !inet_aton(buf, &guest_addr)) {
 603         fail_reason = "Bad guest address";
 604         goto fail_syntax;
 605     }
 606
 607     guest_port = strtol(p, &end, 0);
 608     if (*end != '\0' || guest_port < 1 || guest_port > 65535) {
 609         fail_reason = "Bad guest port";
 610         goto fail_syntax;
 611     }
 612
 613     if (slirp_add_hostfwd(s->slirp, is_udp, host_addr, host_port, guest_addr,
 614                           guest_port) < 0) {
 615         error_setg(errp, "Could not set up host forwarding rule '%s'",
 616                    redir_str);
 617         return -1;
 618     }
 619     return 0;
 620
 621  fail_syntax:
 622     error_setg(errp, "Invalid host forwarding rule '%s' (%s)", redir_str,
 623                fail_reason);
 624     return -1;
 625 }
 626
 627 void hmp_hostfwd_add(Monitor *mon, const QDict *qdict)
 628 {
 629     const char *redir_str;
 630     SlirpState *s;
 631     const char *arg1 = qdict_get_str(qdict, "arg1");
 632     const char *arg2 = qdict_get_try_str(qdict, "arg2");
 633     const char *arg3 = qdict_get_try_str(qdict, "arg3");
 634
 635     if (arg3) {
 636         s = slirp_lookup(mon, arg1, arg2);
 637         redir_str = arg3;
 638     } else if (arg2) {
 639         s = slirp_lookup(mon, NULL, arg1);
 640         redir_str = arg2;
 641     } else {
 642         s = slirp_lookup(mon, NULL, NULL);
 643         redir_str = arg1;
 644     }
 645     if (s) {
 646         Error *err = NULL;
 647         if (slirp_hostfwd(s, redir_str, &err) < 0) {
 648             error_report_err(err);
 649         }
 650     }
 651
 652 }
 653
 654 #ifndef _WIN32
 655
 656 /* automatic user mode samba server configuration */
 657 static void slirp_smb_cleanup(SlirpState *s)
 658 {
 659     int ret;
 660
 661     if (s->smb_dir) {
 662         gchar *cmd = g_strdup_printf("rm -rf %s", s->smb_dir);
 663         ret = system(cmd);
 664         if (ret == -1 || !WIFEXITED(ret)) {
 665             error_report("'%s' failed.", cmd);
 666         } else if (WEXITSTATUS(ret)) {
 667             error_report("'%s' failed. Error code: %d",
 668                          cmd, WEXITSTATUS(ret));
 669         }
 670         g_free(cmd);
 671         g_free(s->smb_dir);
 672         s->smb_dir = NULL;
 673     }
 674 }
 675
 676 static int slirp_smb(SlirpState* s, const char *exported_dir,
 677                      struct in_addr vserver_addr, Error **errp)
 678 {
 679     char *smb_conf;
 680     char *smb_cmdline;
 681     struct passwd *passwd;
 682     FILE *f;
 683
 684     passwd = getpwuid(geteuid());
 685     if (!passwd) {
 686         error_setg(errp, "Failed to retrieve user name");
 687         return -1;
 688     }
 689
 690     if (access(CONFIG_SMBD_COMMAND, F_OK)) {
 691         error_setg(errp, "Could not find '%s', please install it",
 692                    CONFIG_SMBD_COMMAND);
 693         return -1;
 694     }
 695
 696     if (access(exported_dir, R_OK | X_OK)) {
 697         error_setg(errp, "Error accessing shared directory '%s': %s",
 698                    exported_dir, strerror(errno));
 699         return -1;
 700     }
 701
 702     s->smb_dir = g_dir_make_tmp("qemu-smb.XXXXXX", NULL);
 703     if (!s->smb_dir) {
 704         error_setg(errp, "Could not create samba server dir");
 705         return -1;
 706     }
 707     smb_conf = g_strdup_printf("%s/%s", s->smb_dir, "smb.conf");
 708
 709     f = fopen(smb_conf, "w");
 710     if (!f) {
 711         slirp_smb_cleanup(s);
 712         error_setg(errp,
 713                    "Could not create samba server configuration file '%s'",
 714                     smb_conf);
 715         g_free(smb_conf);
 716         return -1;
 717     }
 718     fprintf(f,
 719             "[global]\n"
 720             "private dir=%s\n"
 721             "interfaces=127.0.0.1\n"
 722             "bind interfaces only=yes\n"
 723             "pid directory=%s\n"
 724             "lock directory=%s\n"
 725             "state directory=%s\n"
 726             "cache directory=%s\n"
 727             "ncalrpc dir=%s/ncalrpc\n"
 728             "log file=%s/log.smbd\n"
 729             "smb passwd file=%s/smbpasswd\n"
 730             "security = user\n"
 731             "map to guest = Bad User\n"
 732             "load printers = no\n"
 733             "printing = bsd\n"
 734             "disable spoolss = yes\n"
 735             "usershare max shares = 0\n"
 736             "[qemu]\n"
 737             "path=%s\n"
 738             "read only=no\n"
 739             "guest ok=yes\n"
 740             "force user=%s\n",
 741             s->smb_dir,
 742             s->smb_dir,
 743             s->smb_dir,
 744             s->smb_dir,
 745             s->smb_dir,
 746             s->smb_dir,
 747             s->smb_dir,
 748             s->smb_dir,
 749             exported_dir,
 750             passwd->pw_name
 751             );
 752     fclose(f);
 753
 754     smb_cmdline = g_strdup_printf("%s -l %s -s %s",
 755              CONFIG_SMBD_COMMAND, s->smb_dir, smb_conf);
 756     g_free(smb_conf);
 757
 758     if (slirp_add_exec(s->slirp, smb_cmdline, &vserver_addr, 139) < 0 ||
 759         slirp_add_exec(s->slirp, smb_cmdline, &vserver_addr, 445) < 0) {
 760         slirp_smb_cleanup(s);
 761         g_free(smb_cmdline);
 762         error_setg(errp, "Conflicting/invalid smbserver address");
 763         return -1;
 764     }
 765     g_free(smb_cmdline);
 766     return 0;
 767 }
 768
 769 #endif /* !defined(_WIN32) */
 770
 771 static int guestfwd_can_read(void *opaque)
 772 {
 773     struct GuestFwd *fwd = opaque;
 774     return slirp_socket_can_recv(fwd->slirp, fwd->server, fwd->port);
 775 }
 776
 777 static void guestfwd_read(void *opaque, const uint8_t *buf, int size)
 778 {
 779     struct GuestFwd *fwd = opaque;
 780     slirp_socket_recv(fwd->slirp, fwd->server, fwd->port, buf, size);
 781 }
 782
 783 static int guestfwd_write(const void *buf, size_t len, void *chr)
 784 {
 785     return qemu_chr_fe_write_all(chr, buf, len);
 786 }
 787
 788 static int slirp_guestfwd(SlirpState *s, const char *config_str, Error **errp)
 789 {
 790     struct in_addr server = { .s_addr = 0 };
 791     struct GuestFwd *fwd;
 792     const char *p;
 793     char buf[128];
 794     char *end;
 795     int port;
 796
 797     p = config_str;
 798     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 799         goto fail_syntax;
 800     }
 801     if (strcmp(buf, "tcp") && buf[0] != '\0') {
 802         goto fail_syntax;
 803     }
 804     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 805         goto fail_syntax;
 806     }
 807     if (buf[0] != '\0' && !inet_aton(buf, &server)) {
 808         goto fail_syntax;
 809     }
 810     if (get_str_sep(buf, sizeof(buf), &p, '-') < 0) {
 811         goto fail_syntax;
 812     }
 813     port = strtol(buf, &end, 10);
 814     if (*end != '\0' || port < 1 || port > 65535) {
 815         goto fail_syntax;
 816     }
 817
 818     snprintf(buf, sizeof(buf), "guestfwd.tcp.%d", port);
 819
 820     if (g_str_has_prefix(p, "cmd:")) {
 821         if (slirp_add_exec(s->slirp, &p[4], &server, port) < 0) {
 822             error_setg(errp, "Conflicting/invalid host:port in guest "
 823                        "forwarding rule '%s'", config_str);
 824             return -1;
 825         }
 826     } else {
 827         Error *err = NULL;
 828         /*
 829          * FIXME: sure we want to support implicit
 830          * muxed monitors here?
 831          */
 832         Chardev *chr = qemu_chr_new_mux_mon(buf, p);
 833
 834         if (!chr) {
 835             error_setg(errp, "Could not open guest forwarding device '%s'",
 836                        buf);
 837             return -1;
 838         }
 839
 840         fwd = g_new(struct GuestFwd, 1);
 841         qemu_chr_fe_init(&fwd->hd, chr, &err);
 842         if (err) {
 843             error_propagate(errp, err);
 844             object_unparent(OBJECT(chr));
 845             g_free(fwd);
 846             return -1;
 847         }
 848
 849         if (slirp_add_guestfwd(s->slirp, guestfwd_write, &fwd->hd,
 850                                &server, port) < 0) {
 851             error_setg(errp, "Conflicting/invalid host:port in guest "
 852                        "forwarding rule '%s'", config_str);
 853             qemu_chr_fe_deinit(&fwd->hd, true);
 854             g_free(fwd);
 855             return -1;
 856         }
 857         fwd->server = server;
 858         fwd->port = port;
 859         fwd->slirp = s->slirp;
 860
 861         qemu_chr_fe_set_handlers(&fwd->hd, guestfwd_can_read, guestfwd_read,
 862                                  NULL, NULL, fwd, NULL, true);
 863         s->fwd = g_slist_append(s->fwd, fwd);
 864     }
 865     return 0;
 866
 867  fail_syntax:
 868     error_setg(errp, "Invalid guest forwarding rule '%s'", config_str);
 869     return -1;
 870 }
 871
 872 void hmp_info_usernet(Monitor *mon, const QDict *qdict)
 873 {
 874     SlirpState *s;
 875
 876     QTAILQ_FOREACH(s, &slirp_stacks, entry) {
 877         int id;
 878         bool got_hub_id = net_hub_id_for_client(&s->nc, &id) == 0;
 879         char *info = slirp_connection_info(s->slirp);
 880         monitor_printf(mon, "Hub %d (%s):\n%s",
 881                        got_hub_id ? id : -1,
 882                        s->nc.name, info);
 883         g_free(info);
 884     }
 885 }
 886
 887 static void
 888 net_init_slirp_configs(const StringList *fwd, int flags)
 889 {
 890     while (fwd) {
 891         struct slirp_config_str *config;
 892
 893         config = g_malloc0(sizeof(*config));
 894         pstrcpy(config->str, sizeof(config->str), fwd->value->str);
 895         config->flags = flags;
 896         config->next = slirp_configs;
 897         slirp_configs = config;
 898
 899         fwd = fwd->next;
 900     }
 901 }
 902
 903 static const char **slirp_dnssearch(const StringList *dnsname)
 904 {
 905     const StringList *c = dnsname;
 906     size_t i = 0, num_opts = 0;
 907     const char **ret;
 908
 909     while (c) {
 910         num_opts++;
 911         c = c->next;
 912     }
 913
 914     if (num_opts == 0) {
 915         return NULL;
 916     }
 917
 918     ret = g_malloc((num_opts + 1) * sizeof(*ret));
 919     c = dnsname;
 920     while (c) {
 921         ret[i++] = c->value->str;
 922         c = c->next;
 923     }
 924     ret[i] = NULL;
 925     return ret;
 926 }
 927
 928 int net_init_slirp(const Netdev *netdev, const char *name,
 929                    NetClientState *peer, Error **errp)
 930 {
 931     struct slirp_config_str *config;
 932     char *vnet;
 933     int ret;
 934     const NetdevUserOptions *user;
 935     const char **dnssearch;
 936     bool ipv4 = true, ipv6 = true;
 937
 938     assert(netdev->type == NET_CLIENT_DRIVER_USER);
 939     user = &netdev->u.user;
 940
 941     if ((user->has_ipv6 && user->ipv6 && !user->has_ipv4) ||
 942         (user->has_ipv4 && !user->ipv4)) {
 943         ipv4 = 0;
 944     }
 945     if ((user->has_ipv4 && user->ipv4 && !user->has_ipv6) ||
 946         (user->has_ipv6 && !user->ipv6)) {
 947         ipv6 = 0;
 948     }
 949
 950     vnet = user->has_net ? g_strdup(user->net) :
 951            user->has_ip  ? g_strdup_printf("%s/24", user->ip) :
 952            NULL;
 953
 954     dnssearch = slirp_dnssearch(user->dnssearch);
 955
 956     /* all optional fields are initialized to "all bits zero" */
 957
 958     net_init_slirp_configs(user->hostfwd, SLIRP_CFG_HOSTFWD);
 959     net_init_slirp_configs(user->guestfwd, 0);
 960
 961     ret = net_slirp_init(peer, "user", name, user->q_restrict,
 962                          ipv4, vnet, user->host,
 963                          ipv6, user->ipv6_prefix, user->ipv6_prefixlen,
 964                          user->ipv6_host, user->hostname, user->tftp,
 965                          user->bootfile, user->dhcpstart,
 966                          user->dns, user->ipv6_dns, user->smb,
 967                          user->smbserver, dnssearch, user->domainname,
 968                          user->tftp_server_name, errp);
 969
 970     while (slirp_configs) {
 971         config = slirp_configs;
 972         slirp_configs = config->next;
 973         g_free(config);
 974     }
 975
 976     g_free(vnet);
 977     g_free(dnssearch);
 978
 979     return ret;
 980 }