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 typedef struct SlirpState {
  79     NetClientState nc;
  80     QTAILQ_ENTRY(SlirpState) entry;
  81     Slirp *slirp;
  82     Notifier exit_notifier;
  83 #ifndef _WIN32
  84     gchar *smb_dir;
  85 #endif
  86 } SlirpState;
  87
  88 static struct slirp_config_str *slirp_configs;
  89 static QTAILQ_HEAD(, SlirpState) slirp_stacks =
  90     QTAILQ_HEAD_INITIALIZER(slirp_stacks);
  91
  92 static int slirp_hostfwd(SlirpState *s, const char *redir_str, Error **errp);
  93 static int slirp_guestfwd(SlirpState *s, const char *config_str, Error **errp);
  94
  95 #ifndef _WIN32
  96 static int slirp_smb(SlirpState *s, const char *exported_dir,
  97                      struct in_addr vserver_addr, Error **errp);
  98 static void slirp_smb_cleanup(SlirpState *s);
  99 #else
 100 static inline void slirp_smb_cleanup(SlirpState *s) { }
 101 #endif
 102
 103 static void net_slirp_output(void *opaque, const uint8_t *pkt, int pkt_len)
 104 {
 105     SlirpState *s = opaque;
 106
 107     qemu_send_packet(&s->nc, pkt, pkt_len);
 108 }
 109
 110 static ssize_t net_slirp_receive(NetClientState *nc, const uint8_t *buf, size_t size)
 111 {
 112     SlirpState *s = DO_UPCAST(SlirpState, nc, nc);
 113
 114     slirp_input(s->slirp, buf, size);
 115
 116     return size;
 117 }
 118
 119 static void slirp_smb_exit(Notifier *n, void *data)
 120 {
 121     SlirpState *s = container_of(n, SlirpState, exit_notifier);
 122     slirp_smb_cleanup(s);
 123 }
 124
 125 static void net_slirp_cleanup(NetClientState *nc)
 126 {
 127     SlirpState *s = DO_UPCAST(SlirpState, nc, nc);
 128
 129     slirp_cleanup(s->slirp);
 130     if (s->exit_notifier.notify) {
 131         qemu_remove_exit_notifier(&s->exit_notifier);
 132     }
 133     slirp_smb_cleanup(s);
 134     QTAILQ_REMOVE(&slirp_stacks, s, entry);
 135 }
 136
 137 static NetClientInfo net_slirp_info = {
 138     .type = NET_CLIENT_DRIVER_USER,
 139     .size = sizeof(SlirpState),
 140     .receive = net_slirp_receive,
 141     .cleanup = net_slirp_cleanup,
 142 };
 143
 144 static void net_slirp_guest_error(const char *msg)
 145 {
 146     qemu_log_mask(LOG_GUEST_ERROR, "%s", msg);
 147 }
 148
 149 static int64_t net_slirp_clock_get_ns(void)
 150 {
 151     return qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
 152 }
 153
 154 static const SlirpCb slirp_cb = {
 155     .output = net_slirp_output,
 156     .guest_error = net_slirp_guest_error,
 157     .clock_get_ns = net_slirp_clock_get_ns,
 158 };
 159
 160 static int net_slirp_init(NetClientState *peer, const char *model,
 161                           const char *name, int restricted,
 162                           bool ipv4, const char *vnetwork, const char *vhost,
 163                           bool ipv6, const char *vprefix6, int vprefix6_len,
 164                           const char *vhost6,
 165                           const char *vhostname, const char *tftp_export,
 166                           const char *bootfile, const char *vdhcp_start,
 167                           const char *vnameserver, const char *vnameserver6,
 168                           const char *smb_export, const char *vsmbserver,
 169                           const char **dnssearch, const char *vdomainname,
 170                           const char *tftp_server_name,
 171                           Error **errp)
 172 {
 173     /* default settings according to historic slirp */
 174     struct in_addr net  = { .s_addr = htonl(0x0a000200) }; /* 10.0.2.0 */
 175     struct in_addr mask = { .s_addr = htonl(0xffffff00) }; /* 255.255.255.0 */
 176     struct in_addr host = { .s_addr = htonl(0x0a000202) }; /* 10.0.2.2 */
 177     struct in_addr dhcp = { .s_addr = htonl(0x0a00020f) }; /* 10.0.2.15 */
 178     struct in_addr dns  = { .s_addr = htonl(0x0a000203) }; /* 10.0.2.3 */
 179     struct in6_addr ip6_prefix;
 180     struct in6_addr ip6_host;
 181     struct in6_addr ip6_dns;
 182 #ifndef _WIN32
 183     struct in_addr smbsrv = { .s_addr = 0 };
 184 #endif
 185     NetClientState *nc;
 186     SlirpState *s;
 187     char buf[20];
 188     uint32_t addr;
 189     int shift;
 190     char *end;
 191     struct slirp_config_str *config;
 192
 193     if (!ipv4 && (vnetwork || vhost || vnameserver)) {
 194         error_setg(errp, "IPv4 disabled but netmask/host/dns provided");
 195         return -1;
 196     }
 197
 198     if (!ipv6 && (vprefix6 || vhost6 || vnameserver6)) {
 199         error_setg(errp, "IPv6 disabled but prefix/host6/dns6 provided");
 200         return -1;
 201     }
 202
 203     if (!ipv4 && !ipv6) {
 204         /* It doesn't make sense to disable both */
 205         error_setg(errp, "IPv4 and IPv6 disabled");
 206         return -1;
 207     }
 208
 209     if (vnetwork) {
 210         if (get_str_sep(buf, sizeof(buf), &vnetwork, '/') < 0) {
 211             if (!inet_aton(vnetwork, &net)) {
 212                 error_setg(errp, "Failed to parse netmask");
 213                 return -1;
 214             }
 215             addr = ntohl(net.s_addr);
 216             if (!(addr & 0x80000000)) {
 217                 mask.s_addr = htonl(0xff000000); /* class A */
 218             } else if ((addr & 0xfff00000) == 0xac100000) {
 219                 mask.s_addr = htonl(0xfff00000); /* priv. 172.16.0.0/12 */
 220             } else if ((addr & 0xc0000000) == 0x80000000) {
 221                 mask.s_addr = htonl(0xffff0000); /* class B */
 222             } else if ((addr & 0xffff0000) == 0xc0a80000) {
 223                 mask.s_addr = htonl(0xffff0000); /* priv. 192.168.0.0/16 */
 224             } else if ((addr & 0xffff0000) == 0xc6120000) {
 225                 mask.s_addr = htonl(0xfffe0000); /* tests 198.18.0.0/15 */
 226             } else if ((addr & 0xe0000000) == 0xe0000000) {
 227                 mask.s_addr = htonl(0xffffff00); /* class C */
 228             } else {
 229                 mask.s_addr = htonl(0xfffffff0); /* multicast/reserved */
 230             }
 231         } else {
 232             if (!inet_aton(buf, &net)) {
 233                 error_setg(errp, "Failed to parse netmask");
 234                 return -1;
 235             }
 236             shift = strtol(vnetwork, &end, 10);
 237             if (*end != '\0') {
 238                 if (!inet_aton(vnetwork, &mask)) {
 239                     error_setg(errp,
 240                                "Failed to parse netmask (trailing chars)");
 241                     return -1;
 242                 }
 243             } else if (shift < 4 || shift > 32) {
 244                 error_setg(errp,
 245                            "Invalid netmask provided (must be in range 4-32)");
 246                 return -1;
 247             } else {
 248                 mask.s_addr = htonl(0xffffffff << (32 - shift));
 249             }
 250         }
 251         net.s_addr &= mask.s_addr;
 252         host.s_addr = net.s_addr | (htonl(0x0202) & ~mask.s_addr);
 253         dhcp.s_addr = net.s_addr | (htonl(0x020f) & ~mask.s_addr);
 254         dns.s_addr  = net.s_addr | (htonl(0x0203) & ~mask.s_addr);
 255     }
 256
 257     if (vhost && !inet_aton(vhost, &host)) {
 258         error_setg(errp, "Failed to parse host");
 259         return -1;
 260     }
 261     if ((host.s_addr & mask.s_addr) != net.s_addr) {
 262         error_setg(errp, "Host doesn't belong to network");
 263         return -1;
 264     }
 265
 266     if (vnameserver && !inet_aton(vnameserver, &dns)) {
 267         error_setg(errp, "Failed to parse DNS");
 268         return -1;
 269     }
 270     if ((dns.s_addr & mask.s_addr) != net.s_addr) {
 271         error_setg(errp, "DNS doesn't belong to network");
 272         return -1;
 273     }
 274     if (dns.s_addr == host.s_addr) {
 275         error_setg(errp, "DNS must be different from host");
 276         return -1;
 277     }
 278
 279     if (vdhcp_start && !inet_aton(vdhcp_start, &dhcp)) {
 280         error_setg(errp, "Failed to parse DHCP start address");
 281         return -1;
 282     }
 283     if ((dhcp.s_addr & mask.s_addr) != net.s_addr) {
 284         error_setg(errp, "DHCP doesn't belong to network");
 285         return -1;
 286     }
 287     if (dhcp.s_addr == host.s_addr || dhcp.s_addr == dns.s_addr) {
 288         error_setg(errp, "DNS must be different from host and DNS");
 289         return -1;
 290     }
 291
 292 #ifndef _WIN32
 293     if (vsmbserver && !inet_aton(vsmbserver, &smbsrv)) {
 294         error_setg(errp, "Failed to parse SMB address");
 295         return -1;
 296     }
 297 #endif
 298
 299     if (!vprefix6) {
 300         vprefix6 = "fec0::";
 301     }
 302     if (!inet_pton(AF_INET6, vprefix6, &ip6_prefix)) {
 303         error_setg(errp, "Failed to parse IPv6 prefix");
 304         return -1;
 305     }
 306
 307     if (!vprefix6_len) {
 308         vprefix6_len = 64;
 309     }
 310     if (vprefix6_len < 0 || vprefix6_len > 126) {
 311         error_setg(errp,
 312                    "Invalid prefix provided (prefix len must be in range 0-126");
 313         return -1;
 314     }
 315
 316     if (vhost6) {
 317         if (!inet_pton(AF_INET6, vhost6, &ip6_host)) {
 318             error_setg(errp, "Failed to parse IPv6 host");
 319             return -1;
 320         }
 321         if (!in6_equal_net(&ip6_prefix, &ip6_host, vprefix6_len)) {
 322             error_setg(errp, "IPv6 Host doesn't belong to network");
 323             return -1;
 324         }
 325     } else {
 326         ip6_host = ip6_prefix;
 327         ip6_host.s6_addr[15] |= 2;
 328     }
 329
 330     if (vnameserver6) {
 331         if (!inet_pton(AF_INET6, vnameserver6, &ip6_dns)) {
 332             error_setg(errp, "Failed to parse IPv6 DNS");
 333             return -1;
 334         }
 335         if (!in6_equal_net(&ip6_prefix, &ip6_dns, vprefix6_len)) {
 336             error_setg(errp, "IPv6 DNS doesn't belong to network");
 337             return -1;
 338         }
 339     } else {
 340         ip6_dns = ip6_prefix;
 341         ip6_dns.s6_addr[15] |= 3;
 342     }
 343
 344     if (vdomainname && !*vdomainname) {
 345         error_setg(errp, "'domainname' parameter cannot be empty");
 346         return -1;
 347     }
 348
 349     if (vdomainname && strlen(vdomainname) > 255) {
 350         error_setg(errp, "'domainname' parameter cannot exceed 255 bytes");
 351         return -1;
 352     }
 353
 354     if (vhostname && strlen(vhostname) > 255) {
 355         error_setg(errp, "'vhostname' parameter cannot exceed 255 bytes");
 356         return -1;
 357     }
 358
 359     if (tftp_server_name && strlen(tftp_server_name) > 255) {
 360         error_setg(errp, "'tftp-server-name' parameter cannot exceed 255 bytes");
 361         return -1;
 362     }
 363
 364     nc = qemu_new_net_client(&net_slirp_info, peer, model, name);
 365
 366     snprintf(nc->info_str, sizeof(nc->info_str),
 367              "net=%s,restrict=%s", inet_ntoa(net),
 368              restricted ? "on" : "off");
 369
 370     s = DO_UPCAST(SlirpState, nc, nc);
 371
 372     s->slirp = slirp_init(restricted, ipv4, net, mask, host,
 373                           ipv6, ip6_prefix, vprefix6_len, ip6_host,
 374                           vhostname, tftp_server_name,
 375                           tftp_export, bootfile, dhcp,
 376                           dns, ip6_dns, dnssearch, vdomainname,
 377                           &slirp_cb, s);
 378     QTAILQ_INSERT_TAIL(&slirp_stacks, s, entry);
 379
 380     for (config = slirp_configs; config; config = config->next) {
 381         if (config->flags & SLIRP_CFG_HOSTFWD) {
 382             if (slirp_hostfwd(s, config->str, errp) < 0) {
 383                 goto error;
 384             }
 385         } else {
 386             if (slirp_guestfwd(s, config->str, errp) < 0) {
 387                 goto error;
 388             }
 389         }
 390     }
 391 #ifndef _WIN32
 392     if (smb_export) {
 393         if (slirp_smb(s, smb_export, smbsrv, errp) < 0) {
 394             goto error;
 395         }
 396     }
 397 #endif
 398
 399     s->exit_notifier.notify = slirp_smb_exit;
 400     qemu_add_exit_notifier(&s->exit_notifier);
 401     return 0;
 402
 403 error:
 404     qemu_del_net_client(nc);
 405     return -1;
 406 }
 407
 408 static SlirpState *slirp_lookup(Monitor *mon, const char *hub_id,
 409                                 const char *name)
 410 {
 411     if (name) {
 412         NetClientState *nc;
 413         if (hub_id) {
 414             nc = net_hub_find_client_by_name(strtol(hub_id, NULL, 0), name);
 415             if (!nc) {
 416                 monitor_printf(mon, "unrecognized (hub-id, stackname) pair\n");
 417                 return NULL;
 418             }
 419             warn_report("Using 'hub-id' is deprecated, specify the netdev id "
 420                         "directly instead");
 421         } else {
 422             nc = qemu_find_netdev(name);
 423             if (!nc) {
 424                 monitor_printf(mon, "unrecognized netdev id '%s'\n", name);
 425                 return NULL;
 426             }
 427         }
 428         if (strcmp(nc->model, "user")) {
 429             monitor_printf(mon, "invalid device specified\n");
 430             return NULL;
 431         }
 432         return DO_UPCAST(SlirpState, nc, nc);
 433     } else {
 434         if (QTAILQ_EMPTY(&slirp_stacks)) {
 435             monitor_printf(mon, "user mode network stack not in use\n");
 436             return NULL;
 437         }
 438         return QTAILQ_FIRST(&slirp_stacks);
 439     }
 440 }
 441
 442 void hmp_hostfwd_remove(Monitor *mon, const QDict *qdict)
 443 {
 444     struct in_addr host_addr = { .s_addr = INADDR_ANY };
 445     int host_port;
 446     char buf[256];
 447     const char *src_str, *p;
 448     SlirpState *s;
 449     int is_udp = 0;
 450     int err;
 451     const char *arg1 = qdict_get_str(qdict, "arg1");
 452     const char *arg2 = qdict_get_try_str(qdict, "arg2");
 453     const char *arg3 = qdict_get_try_str(qdict, "arg3");
 454
 455     if (arg3) {
 456         s = slirp_lookup(mon, arg1, arg2);
 457         src_str = arg3;
 458     } else if (arg2) {
 459         s = slirp_lookup(mon, NULL, arg1);
 460         src_str = arg2;
 461     } else {
 462         s = slirp_lookup(mon, NULL, NULL);
 463         src_str = arg1;
 464     }
 465     if (!s) {
 466         return;
 467     }
 468
 469     p = src_str;
 470     if (!p || get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 471         goto fail_syntax;
 472     }
 473
 474     if (!strcmp(buf, "tcp") || buf[0] == '\0') {
 475         is_udp = 0;
 476     } else if (!strcmp(buf, "udp")) {
 477         is_udp = 1;
 478     } else {
 479         goto fail_syntax;
 480     }
 481
 482     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 483         goto fail_syntax;
 484     }
 485     if (buf[0] != '\0' && !inet_aton(buf, &host_addr)) {
 486         goto fail_syntax;
 487     }
 488
 489     if (qemu_strtoi(p, NULL, 10, &host_port)) {
 490         goto fail_syntax;
 491     }
 492
 493     err = slirp_remove_hostfwd(s->slirp, is_udp, host_addr, host_port);
 494
 495     monitor_printf(mon, "host forwarding rule for %s %s\n", src_str,
 496                    err ? "not found" : "removed");
 497     return;
 498
 499  fail_syntax:
 500     monitor_printf(mon, "invalid format\n");
 501 }
 502
 503 static int slirp_hostfwd(SlirpState *s, const char *redir_str, Error **errp)
 504 {
 505     struct in_addr host_addr = { .s_addr = INADDR_ANY };
 506     struct in_addr guest_addr = { .s_addr = 0 };
 507     int host_port, guest_port;
 508     const char *p;
 509     char buf[256];
 510     int is_udp;
 511     char *end;
 512     const char *fail_reason = "Unknown reason";
 513
 514     p = redir_str;
 515     if (!p || get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 516         fail_reason = "No : separators";
 517         goto fail_syntax;
 518     }
 519     if (!strcmp(buf, "tcp") || buf[0] == '\0') {
 520         is_udp = 0;
 521     } else if (!strcmp(buf, "udp")) {
 522         is_udp = 1;
 523     } else {
 524         fail_reason = "Bad protocol name";
 525         goto fail_syntax;
 526     }
 527
 528     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 529         fail_reason = "Missing : separator";
 530         goto fail_syntax;
 531     }
 532     if (buf[0] != '\0' && !inet_aton(buf, &host_addr)) {
 533         fail_reason = "Bad host address";
 534         goto fail_syntax;
 535     }
 536
 537     if (get_str_sep(buf, sizeof(buf), &p, '-') < 0) {
 538         fail_reason = "Bad host port separator";
 539         goto fail_syntax;
 540     }
 541     host_port = strtol(buf, &end, 0);
 542     if (*end != '\0' || host_port < 0 || host_port > 65535) {
 543         fail_reason = "Bad host port";
 544         goto fail_syntax;
 545     }
 546
 547     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 548         fail_reason = "Missing guest address";
 549         goto fail_syntax;
 550     }
 551     if (buf[0] != '\0' && !inet_aton(buf, &guest_addr)) {
 552         fail_reason = "Bad guest address";
 553         goto fail_syntax;
 554     }
 555
 556     guest_port = strtol(p, &end, 0);
 557     if (*end != '\0' || guest_port < 1 || guest_port > 65535) {
 558         fail_reason = "Bad guest port";
 559         goto fail_syntax;
 560     }
 561
 562     if (slirp_add_hostfwd(s->slirp, is_udp, host_addr, host_port, guest_addr,
 563                           guest_port) < 0) {
 564         error_setg(errp, "Could not set up host forwarding rule '%s'",
 565                    redir_str);
 566         return -1;
 567     }
 568     return 0;
 569
 570  fail_syntax:
 571     error_setg(errp, "Invalid host forwarding rule '%s' (%s)", redir_str,
 572                fail_reason);
 573     return -1;
 574 }
 575
 576 void hmp_hostfwd_add(Monitor *mon, const QDict *qdict)
 577 {
 578     const char *redir_str;
 579     SlirpState *s;
 580     const char *arg1 = qdict_get_str(qdict, "arg1");
 581     const char *arg2 = qdict_get_try_str(qdict, "arg2");
 582     const char *arg3 = qdict_get_try_str(qdict, "arg3");
 583
 584     if (arg3) {
 585         s = slirp_lookup(mon, arg1, arg2);
 586         redir_str = arg3;
 587     } else if (arg2) {
 588         s = slirp_lookup(mon, NULL, arg1);
 589         redir_str = arg2;
 590     } else {
 591         s = slirp_lookup(mon, NULL, NULL);
 592         redir_str = arg1;
 593     }
 594     if (s) {
 595         Error *err = NULL;
 596         if (slirp_hostfwd(s, redir_str, &err) < 0) {
 597             error_report_err(err);
 598         }
 599     }
 600
 601 }
 602
 603 #ifndef _WIN32
 604
 605 /* automatic user mode samba server configuration */
 606 static void slirp_smb_cleanup(SlirpState *s)
 607 {
 608     int ret;
 609
 610     if (s->smb_dir) {
 611         gchar *cmd = g_strdup_printf("rm -rf %s", s->smb_dir);
 612         ret = system(cmd);
 613         if (ret == -1 || !WIFEXITED(ret)) {
 614             error_report("'%s' failed.", cmd);
 615         } else if (WEXITSTATUS(ret)) {
 616             error_report("'%s' failed. Error code: %d",
 617                          cmd, WEXITSTATUS(ret));
 618         }
 619         g_free(cmd);
 620         g_free(s->smb_dir);
 621         s->smb_dir = NULL;
 622     }
 623 }
 624
 625 static int slirp_smb(SlirpState* s, const char *exported_dir,
 626                      struct in_addr vserver_addr, Error **errp)
 627 {
 628     char *smb_conf;
 629     char *smb_cmdline;
 630     struct passwd *passwd;
 631     FILE *f;
 632
 633     passwd = getpwuid(geteuid());
 634     if (!passwd) {
 635         error_setg(errp, "Failed to retrieve user name");
 636         return -1;
 637     }
 638
 639     if (access(CONFIG_SMBD_COMMAND, F_OK)) {
 640         error_setg(errp, "Could not find '%s', please install it",
 641                    CONFIG_SMBD_COMMAND);
 642         return -1;
 643     }
 644
 645     if (access(exported_dir, R_OK | X_OK)) {
 646         error_setg(errp, "Error accessing shared directory '%s': %s",
 647                    exported_dir, strerror(errno));
 648         return -1;
 649     }
 650
 651     s->smb_dir = g_dir_make_tmp("qemu-smb.XXXXXX", NULL);
 652     if (!s->smb_dir) {
 653         error_setg(errp, "Could not create samba server dir");
 654         return -1;
 655     }
 656     smb_conf = g_strdup_printf("%s/%s", s->smb_dir, "smb.conf");
 657
 658     f = fopen(smb_conf, "w");
 659     if (!f) {
 660         slirp_smb_cleanup(s);
 661         error_setg(errp,
 662                    "Could not create samba server configuration file '%s'",
 663                     smb_conf);
 664         g_free(smb_conf);
 665         return -1;
 666     }
 667     fprintf(f,
 668             "[global]\n"
 669             "private dir=%s\n"
 670             "interfaces=127.0.0.1\n"
 671             "bind interfaces only=yes\n"
 672             "pid directory=%s\n"
 673             "lock directory=%s\n"
 674             "state directory=%s\n"
 675             "cache directory=%s\n"
 676             "ncalrpc dir=%s/ncalrpc\n"
 677             "log file=%s/log.smbd\n"
 678             "smb passwd file=%s/smbpasswd\n"
 679             "security = user\n"
 680             "map to guest = Bad User\n"
 681             "load printers = no\n"
 682             "printing = bsd\n"
 683             "disable spoolss = yes\n"
 684             "usershare max shares = 0\n"
 685             "[qemu]\n"
 686             "path=%s\n"
 687             "read only=no\n"
 688             "guest ok=yes\n"
 689             "force user=%s\n",
 690             s->smb_dir,
 691             s->smb_dir,
 692             s->smb_dir,
 693             s->smb_dir,
 694             s->smb_dir,
 695             s->smb_dir,
 696             s->smb_dir,
 697             s->smb_dir,
 698             exported_dir,
 699             passwd->pw_name
 700             );
 701     fclose(f);
 702
 703     smb_cmdline = g_strdup_printf("%s -l %s -s %s",
 704              CONFIG_SMBD_COMMAND, s->smb_dir, smb_conf);
 705     g_free(smb_conf);
 706
 707     if (slirp_add_exec(s->slirp, NULL, smb_cmdline, &vserver_addr, 139) < 0 ||
 708         slirp_add_exec(s->slirp, NULL, smb_cmdline, &vserver_addr, 445) < 0) {
 709         slirp_smb_cleanup(s);
 710         g_free(smb_cmdline);
 711         error_setg(errp, "Conflicting/invalid smbserver address");
 712         return -1;
 713     }
 714     g_free(smb_cmdline);
 715     return 0;
 716 }
 717
 718 #endif /* !defined(_WIN32) */
 719
 720 struct GuestFwd {
 721     CharBackend hd;
 722     struct in_addr server;
 723     int port;
 724     Slirp *slirp;
 725 };
 726
 727 static int guestfwd_can_read(void *opaque)
 728 {
 729     struct GuestFwd *fwd = opaque;
 730     return slirp_socket_can_recv(fwd->slirp, fwd->server, fwd->port);
 731 }
 732
 733 static void guestfwd_read(void *opaque, const uint8_t *buf, int size)
 734 {
 735     struct GuestFwd *fwd = opaque;
 736     slirp_socket_recv(fwd->slirp, fwd->server, fwd->port, buf, size);
 737 }
 738
 739 static int slirp_guestfwd(SlirpState *s, const char *config_str, Error **errp)
 740 {
 741     struct in_addr server = { .s_addr = 0 };
 742     struct GuestFwd *fwd;
 743     const char *p;
 744     char buf[128];
 745     char *end;
 746     int port;
 747
 748     p = config_str;
 749     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 750         goto fail_syntax;
 751     }
 752     if (strcmp(buf, "tcp") && buf[0] != '\0') {
 753         goto fail_syntax;
 754     }
 755     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 756         goto fail_syntax;
 757     }
 758     if (buf[0] != '\0' && !inet_aton(buf, &server)) {
 759         goto fail_syntax;
 760     }
 761     if (get_str_sep(buf, sizeof(buf), &p, '-') < 0) {
 762         goto fail_syntax;
 763     }
 764     port = strtol(buf, &end, 10);
 765     if (*end != '\0' || port < 1 || port > 65535) {
 766         goto fail_syntax;
 767     }
 768
 769     snprintf(buf, sizeof(buf), "guestfwd.tcp.%d", port);
 770
 771     if ((strlen(p) > 4) && !strncmp(p, "cmd:", 4)) {
 772         if (slirp_add_exec(s->slirp, NULL, &p[4], &server, port) < 0) {
 773             error_setg(errp, "Conflicting/invalid host:port in guest "
 774                        "forwarding rule '%s'", config_str);
 775             return -1;
 776         }
 777     } else {
 778         Error *err = NULL;
 779         /*
 780          * FIXME: sure we want to support implicit
 781          * muxed monitors here?
 782          */
 783         Chardev *chr = qemu_chr_new_mux_mon(buf, p);
 784
 785         if (!chr) {
 786             error_setg(errp, "Could not open guest forwarding device '%s'",
 787                        buf);
 788             return -1;
 789         }
 790
 791         fwd = g_new(struct GuestFwd, 1);
 792         qemu_chr_fe_init(&fwd->hd, chr, &err);
 793         if (err) {
 794             error_propagate(errp, err);
 795             g_free(fwd);
 796             return -1;
 797         }
 798
 799         if (slirp_add_exec(s->slirp, &fwd->hd, NULL, &server, port) < 0) {
 800             error_setg(errp, "Conflicting/invalid host:port in guest "
 801                        "forwarding rule '%s'", config_str);
 802             g_free(fwd);
 803             return -1;
 804         }
 805         fwd->server = server;
 806         fwd->port = port;
 807         fwd->slirp = s->slirp;
 808
 809         qemu_chr_fe_set_handlers(&fwd->hd, guestfwd_can_read, guestfwd_read,
 810                                  NULL, NULL, fwd, NULL, true);
 811     }
 812     return 0;
 813
 814  fail_syntax:
 815     error_setg(errp, "Invalid guest forwarding rule '%s'", config_str);
 816     return -1;
 817 }
 818
 819 void hmp_info_usernet(Monitor *mon, const QDict *qdict)
 820 {
 821     SlirpState *s;
 822
 823     QTAILQ_FOREACH(s, &slirp_stacks, entry) {
 824         int id;
 825         bool got_hub_id = net_hub_id_for_client(&s->nc, &id) == 0;
 826         char *info = slirp_connection_info(s->slirp);
 827         monitor_printf(mon, "Hub %d (%s):\n%s",
 828                        got_hub_id ? id : -1,
 829                        s->nc.name, info);
 830         g_free(info);
 831     }
 832 }
 833
 834 static void
 835 net_init_slirp_configs(const StringList *fwd, int flags)
 836 {
 837     while (fwd) {
 838         struct slirp_config_str *config;
 839
 840         config = g_malloc0(sizeof(*config));
 841         pstrcpy(config->str, sizeof(config->str), fwd->value->str);
 842         config->flags = flags;
 843         config->next = slirp_configs;
 844         slirp_configs = config;
 845
 846         fwd = fwd->next;
 847     }
 848 }
 849
 850 static const char **slirp_dnssearch(const StringList *dnsname)
 851 {
 852     const StringList *c = dnsname;
 853     size_t i = 0, num_opts = 0;
 854     const char **ret;
 855
 856     while (c) {
 857         num_opts++;
 858         c = c->next;
 859     }
 860
 861     if (num_opts == 0) {
 862         return NULL;
 863     }
 864
 865     ret = g_malloc((num_opts + 1) * sizeof(*ret));
 866     c = dnsname;
 867     while (c) {
 868         ret[i++] = c->value->str;
 869         c = c->next;
 870     }
 871     ret[i] = NULL;
 872     return ret;
 873 }
 874
 875 int net_init_slirp(const Netdev *netdev, const char *name,
 876                    NetClientState *peer, Error **errp)
 877 {
 878     struct slirp_config_str *config;
 879     char *vnet;
 880     int ret;
 881     const NetdevUserOptions *user;
 882     const char **dnssearch;
 883     bool ipv4 = true, ipv6 = true;
 884
 885     assert(netdev->type == NET_CLIENT_DRIVER_USER);
 886     user = &netdev->u.user;
 887
 888     if ((user->has_ipv6 && user->ipv6 && !user->has_ipv4) ||
 889         (user->has_ipv4 && !user->ipv4)) {
 890         ipv4 = 0;
 891     }
 892     if ((user->has_ipv4 && user->ipv4 && !user->has_ipv6) ||
 893         (user->has_ipv6 && !user->ipv6)) {
 894         ipv6 = 0;
 895     }
 896
 897     vnet = user->has_net ? g_strdup(user->net) :
 898            user->has_ip  ? g_strdup_printf("%s/24", user->ip) :
 899            NULL;
 900
 901     dnssearch = slirp_dnssearch(user->dnssearch);
 902
 903     /* all optional fields are initialized to "all bits zero" */
 904
 905     net_init_slirp_configs(user->hostfwd, SLIRP_CFG_HOSTFWD);
 906     net_init_slirp_configs(user->guestfwd, 0);
 907
 908     ret = net_slirp_init(peer, "user", name, user->q_restrict,
 909                          ipv4, vnet, user->host,
 910                          ipv6, user->ipv6_prefix, user->ipv6_prefixlen,
 911                          user->ipv6_host, user->hostname, user->tftp,
 912                          user->bootfile, user->dhcpstart,
 913                          user->dns, user->ipv6_dns, user->smb,
 914                          user->smbserver, dnssearch, user->domainname,
 915                          user->tftp_server_name, errp);
 916
 917     while (slirp_configs) {
 918         config = slirp_configs;
 919         slirp_configs = config->next;
 920         g_free(config);
 921     }
 922
 923     g_free(vnet);
 924     g_free(dnssearch);
 925
 926     return ret;
 927 }