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