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 #include "net/slirp.h"
  25
  26 #include "config-host.h"
  27
  28 #ifndef _WIN32
  29 #include <pwd.h>
  30 #include <sys/wait.h>
  31 #endif
  32 #include "net/net.h"
  33 #include "clients.h"
  34 #include "hub.h"
  35 #include "monitor/monitor.h"
  36 #include "qemu/error-report.h"
  37 #include "qemu/sockets.h"
  38 #include "slirp/libslirp.h"
  39 #include "sysemu/char.h"
  40
  41 static int get_str_sep(char *buf, int buf_size, const char **pp, int sep)
  42 {
  43     const char *p, *p1;
  44     int len;
  45     p = *pp;
  46     p1 = strchr(p, sep);
  47     if (!p1)
  48         return -1;
  49     len = p1 - p;
  50     p1++;
  51     if (buf_size > 0) {
  52         if (len > buf_size - 1)
  53             len = buf_size - 1;
  54         memcpy(buf, p, len);
  55         buf[len] = '\0';
  56     }
  57     *pp = p1;
  58     return 0;
  59 }
  60
  61 /* slirp network adapter */
  62
  63 #define SLIRP_CFG_HOSTFWD 1
  64 #define SLIRP_CFG_LEGACY  2
  65
  66 struct slirp_config_str {
  67     struct slirp_config_str *next;
  68     int flags;
  69     char str[1024];
  70     int legacy_format;
  71 };
  72
  73 typedef struct SlirpState {
  74     NetClientState nc;
  75     QTAILQ_ENTRY(SlirpState) entry;
  76     Slirp *slirp;
  77 #ifndef _WIN32
  78     char smb_dir[128];
  79 #endif
  80 } SlirpState;
  81
  82 static struct slirp_config_str *slirp_configs;
  83 const char *legacy_tftp_prefix;
  84 const char *legacy_bootp_filename;
  85 static QTAILQ_HEAD(slirp_stacks, SlirpState) slirp_stacks =
  86     QTAILQ_HEAD_INITIALIZER(slirp_stacks);
  87
  88 static int slirp_hostfwd(SlirpState *s, const char *redir_str,
  89                          int legacy_format);
  90 static int slirp_guestfwd(SlirpState *s, const char *config_str,
  91                           int legacy_format);
  92
  93 #ifndef _WIN32
  94 static const char *legacy_smb_export;
  95
  96 static int slirp_smb(SlirpState *s, const char *exported_dir,
  97                      struct in_addr vserver_addr);
  98 static void slirp_smb_cleanup(SlirpState *s);
  99 #else
 100 static inline void slirp_smb_cleanup(SlirpState *s) { }
 101 #endif
 102
 103 void 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 net_slirp_cleanup(NetClientState *nc)
 120 {
 121     SlirpState *s = DO_UPCAST(SlirpState, nc, nc);
 122
 123     slirp_cleanup(s->slirp);
 124     slirp_smb_cleanup(s);
 125     QTAILQ_REMOVE(&slirp_stacks, s, entry);
 126 }
 127
 128 static NetClientInfo net_slirp_info = {
 129     .type = NET_CLIENT_OPTIONS_KIND_USER,
 130     .size = sizeof(SlirpState),
 131     .receive = net_slirp_receive,
 132     .cleanup = net_slirp_cleanup,
 133 };
 134
 135 static int net_slirp_init(NetClientState *peer, const char *model,
 136                           const char *name, int restricted,
 137                           const char *vnetwork, const char *vhost,
 138                           const char *vhostname, const char *tftp_export,
 139                           const char *bootfile, const char *vdhcp_start,
 140                           const char *vnameserver, const char *smb_export,
 141                           const char *vsmbserver, const char **dnssearch)
 142 {
 143     /* default settings according to historic slirp */
 144     struct in_addr net  = { .s_addr = htonl(0x0a000200) }; /* 10.0.2.0 */
 145     struct in_addr mask = { .s_addr = htonl(0xffffff00) }; /* 255.255.255.0 */
 146     struct in_addr host = { .s_addr = htonl(0x0a000202) }; /* 10.0.2.2 */
 147     struct in_addr dhcp = { .s_addr = htonl(0x0a00020f) }; /* 10.0.2.15 */
 148     struct in_addr dns  = { .s_addr = htonl(0x0a000203) }; /* 10.0.2.3 */
 149 #ifndef _WIN32
 150     struct in_addr smbsrv = { .s_addr = 0 };
 151 #endif
 152     NetClientState *nc;
 153     SlirpState *s;
 154     char buf[20];
 155     uint32_t addr;
 156     int shift;
 157     char *end;
 158     struct slirp_config_str *config;
 159
 160     if (!tftp_export) {
 161         tftp_export = legacy_tftp_prefix;
 162     }
 163     if (!bootfile) {
 164         bootfile = legacy_bootp_filename;
 165     }
 166
 167     if (vnetwork) {
 168         if (get_str_sep(buf, sizeof(buf), &vnetwork, '/') < 0) {
 169             if (!inet_aton(vnetwork, &net)) {
 170                 return -1;
 171             }
 172             addr = ntohl(net.s_addr);
 173             if (!(addr & 0x80000000)) {
 174                 mask.s_addr = htonl(0xff000000); /* class A */
 175             } else if ((addr & 0xfff00000) == 0xac100000) {
 176                 mask.s_addr = htonl(0xfff00000); /* priv. 172.16.0.0/12 */
 177             } else if ((addr & 0xc0000000) == 0x80000000) {
 178                 mask.s_addr = htonl(0xffff0000); /* class B */
 179             } else if ((addr & 0xffff0000) == 0xc0a80000) {
 180                 mask.s_addr = htonl(0xffff0000); /* priv. 192.168.0.0/16 */
 181             } else if ((addr & 0xffff0000) == 0xc6120000) {
 182                 mask.s_addr = htonl(0xfffe0000); /* tests 198.18.0.0/15 */
 183             } else if ((addr & 0xe0000000) == 0xe0000000) {
 184                 mask.s_addr = htonl(0xffffff00); /* class C */
 185             } else {
 186                 mask.s_addr = htonl(0xfffffff0); /* multicast/reserved */
 187             }
 188         } else {
 189             if (!inet_aton(buf, &net)) {
 190                 return -1;
 191             }
 192             shift = strtol(vnetwork, &end, 10);
 193             if (*end != '\0') {
 194                 if (!inet_aton(vnetwork, &mask)) {
 195                     return -1;
 196                 }
 197             } else if (shift < 4 || shift > 32) {
 198                 return -1;
 199             } else {
 200                 mask.s_addr = htonl(0xffffffff << (32 - shift));
 201             }
 202         }
 203         net.s_addr &= mask.s_addr;
 204         host.s_addr = net.s_addr | (htonl(0x0202) & ~mask.s_addr);
 205         dhcp.s_addr = net.s_addr | (htonl(0x020f) & ~mask.s_addr);
 206         dns.s_addr  = net.s_addr | (htonl(0x0203) & ~mask.s_addr);
 207     }
 208
 209     if (vhost && !inet_aton(vhost, &host)) {
 210         return -1;
 211     }
 212     if ((host.s_addr & mask.s_addr) != net.s_addr) {
 213         return -1;
 214     }
 215
 216     if (vnameserver && !inet_aton(vnameserver, &dns)) {
 217         return -1;
 218     }
 219     if ((dns.s_addr & mask.s_addr) != net.s_addr ||
 220         dns.s_addr == host.s_addr) {
 221         return -1;
 222     }
 223
 224     if (vdhcp_start && !inet_aton(vdhcp_start, &dhcp)) {
 225         return -1;
 226     }
 227     if ((dhcp.s_addr & mask.s_addr) != net.s_addr ||
 228         dhcp.s_addr == host.s_addr || dhcp.s_addr == dns.s_addr) {
 229         return -1;
 230     }
 231
 232 #ifndef _WIN32
 233     if (vsmbserver && !inet_aton(vsmbserver, &smbsrv)) {
 234         return -1;
 235     }
 236 #endif
 237
 238     nc = qemu_new_net_client(&net_slirp_info, peer, model, name);
 239
 240     snprintf(nc->info_str, sizeof(nc->info_str),
 241              "net=%s,restrict=%s", inet_ntoa(net),
 242              restricted ? "on" : "off");
 243
 244     s = DO_UPCAST(SlirpState, nc, nc);
 245
 246     s->slirp = slirp_init(restricted, net, mask, host, vhostname,
 247                           tftp_export, bootfile, dhcp, dns, dnssearch, s);
 248     QTAILQ_INSERT_TAIL(&slirp_stacks, s, entry);
 249
 250     for (config = slirp_configs; config; config = config->next) {
 251         if (config->flags & SLIRP_CFG_HOSTFWD) {
 252             if (slirp_hostfwd(s, config->str,
 253                               config->flags & SLIRP_CFG_LEGACY) < 0)
 254                 goto error;
 255         } else {
 256             if (slirp_guestfwd(s, config->str,
 257                                config->flags & SLIRP_CFG_LEGACY) < 0)
 258                 goto error;
 259         }
 260     }
 261 #ifndef _WIN32
 262     if (!smb_export) {
 263         smb_export = legacy_smb_export;
 264     }
 265     if (smb_export) {
 266         if (slirp_smb(s, smb_export, smbsrv) < 0)
 267             goto error;
 268     }
 269 #endif
 270
 271     return 0;
 272
 273 error:
 274     qemu_del_net_client(nc);
 275     return -1;
 276 }
 277
 278 static SlirpState *slirp_lookup(Monitor *mon, const char *vlan,
 279                                 const char *stack)
 280 {
 281
 282     if (vlan) {
 283         NetClientState *nc;
 284         nc = net_hub_find_client_by_name(strtol(vlan, NULL, 0), stack);
 285         if (!nc) {
 286             monitor_printf(mon, "unrecognized (vlan-id, stackname) pair\n");
 287             return NULL;
 288         }
 289         if (strcmp(nc->model, "user")) {
 290             monitor_printf(mon, "invalid device specified\n");
 291             return NULL;
 292         }
 293         return DO_UPCAST(SlirpState, nc, nc);
 294     } else {
 295         if (QTAILQ_EMPTY(&slirp_stacks)) {
 296             monitor_printf(mon, "user mode network stack not in use\n");
 297             return NULL;
 298         }
 299         return QTAILQ_FIRST(&slirp_stacks);
 300     }
 301 }
 302
 303 void hmp_hostfwd_remove(Monitor *mon, const QDict *qdict)
 304 {
 305     struct in_addr host_addr = { .s_addr = INADDR_ANY };
 306     int host_port;
 307     char buf[256];
 308     const char *src_str, *p;
 309     SlirpState *s;
 310     int is_udp = 0;
 311     int err;
 312     const char *arg1 = qdict_get_str(qdict, "arg1");
 313     const char *arg2 = qdict_get_try_str(qdict, "arg2");
 314     const char *arg3 = qdict_get_try_str(qdict, "arg3");
 315
 316     if (arg2) {
 317         s = slirp_lookup(mon, arg1, arg2);
 318         src_str = arg3;
 319     } else {
 320         s = slirp_lookup(mon, NULL, NULL);
 321         src_str = arg1;
 322     }
 323     if (!s) {
 324         return;
 325     }
 326
 327     p = src_str;
 328     if (!p || get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 329         goto fail_syntax;
 330     }
 331
 332     if (!strcmp(buf, "tcp") || buf[0] == '\0') {
 333         is_udp = 0;
 334     } else if (!strcmp(buf, "udp")) {
 335         is_udp = 1;
 336     } else {
 337         goto fail_syntax;
 338     }
 339
 340     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 341         goto fail_syntax;
 342     }
 343     if (buf[0] != '\0' && !inet_aton(buf, &host_addr)) {
 344         goto fail_syntax;
 345     }
 346
 347     host_port = atoi(p);
 348
 349     err = slirp_remove_hostfwd(s->slirp, is_udp, host_addr, host_port);
 350
 351     monitor_printf(mon, "host forwarding rule for %s %s\n", src_str,
 352                    err ? "not found" : "removed");
 353     return;
 354
 355  fail_syntax:
 356     monitor_printf(mon, "invalid format\n");
 357 }
 358
 359 static int slirp_hostfwd(SlirpState *s, const char *redir_str,
 360                          int legacy_format)
 361 {
 362     struct in_addr host_addr = { .s_addr = INADDR_ANY };
 363     struct in_addr guest_addr = { .s_addr = 0 };
 364     int host_port, guest_port;
 365     const char *p;
 366     char buf[256];
 367     int is_udp;
 368     char *end;
 369
 370     p = redir_str;
 371     if (!p || get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 372         goto fail_syntax;
 373     }
 374     if (!strcmp(buf, "tcp") || buf[0] == '\0') {
 375         is_udp = 0;
 376     } else if (!strcmp(buf, "udp")) {
 377         is_udp = 1;
 378     } else {
 379         goto fail_syntax;
 380     }
 381
 382     if (!legacy_format) {
 383         if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 384             goto fail_syntax;
 385         }
 386         if (buf[0] != '\0' && !inet_aton(buf, &host_addr)) {
 387             goto fail_syntax;
 388         }
 389     }
 390
 391     if (get_str_sep(buf, sizeof(buf), &p, legacy_format ? ':' : '-') < 0) {
 392         goto fail_syntax;
 393     }
 394     host_port = strtol(buf, &end, 0);
 395     if (*end != '\0' || host_port < 1 || host_port > 65535) {
 396         goto fail_syntax;
 397     }
 398
 399     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 400         goto fail_syntax;
 401     }
 402     if (buf[0] != '\0' && !inet_aton(buf, &guest_addr)) {
 403         goto fail_syntax;
 404     }
 405
 406     guest_port = strtol(p, &end, 0);
 407     if (*end != '\0' || guest_port < 1 || guest_port > 65535) {
 408         goto fail_syntax;
 409     }
 410
 411     if (slirp_add_hostfwd(s->slirp, is_udp, host_addr, host_port, guest_addr,
 412                           guest_port) < 0) {
 413         error_report("could not set up host forwarding rule '%s'",
 414                      redir_str);
 415         return -1;
 416     }
 417     return 0;
 418
 419  fail_syntax:
 420     error_report("invalid host forwarding rule '%s'", redir_str);
 421     return -1;
 422 }
 423
 424 void hmp_hostfwd_add(Monitor *mon, const QDict *qdict)
 425 {
 426     const char *redir_str;
 427     SlirpState *s;
 428     const char *arg1 = qdict_get_str(qdict, "arg1");
 429     const char *arg2 = qdict_get_try_str(qdict, "arg2");
 430     const char *arg3 = qdict_get_try_str(qdict, "arg3");
 431
 432     if (arg2) {
 433         s = slirp_lookup(mon, arg1, arg2);
 434         redir_str = arg3;
 435     } else {
 436         s = slirp_lookup(mon, NULL, NULL);
 437         redir_str = arg1;
 438     }
 439     if (s) {
 440         slirp_hostfwd(s, redir_str, 0);
 441     }
 442
 443 }
 444
 445 int net_slirp_redir(const char *redir_str)
 446 {
 447     struct slirp_config_str *config;
 448
 449     if (QTAILQ_EMPTY(&slirp_stacks)) {
 450         config = g_malloc(sizeof(*config));
 451         pstrcpy(config->str, sizeof(config->str), redir_str);
 452         config->flags = SLIRP_CFG_HOSTFWD | SLIRP_CFG_LEGACY;
 453         config->next = slirp_configs;
 454         slirp_configs = config;
 455         return 0;
 456     }
 457
 458     return slirp_hostfwd(QTAILQ_FIRST(&slirp_stacks), redir_str, 1);
 459 }
 460
 461 #ifndef _WIN32
 462
 463 /* automatic user mode samba server configuration */
 464 static void slirp_smb_cleanup(SlirpState *s)
 465 {
 466     char cmd[128];
 467     int ret;
 468
 469     if (s->smb_dir[0] != '\0') {
 470         snprintf(cmd, sizeof(cmd), "rm -rf %s", s->smb_dir);
 471         ret = system(cmd);
 472         if (ret == -1 || !WIFEXITED(ret)) {
 473             error_report("'%s' failed.", cmd);
 474         } else if (WEXITSTATUS(ret)) {
 475             error_report("'%s' failed. Error code: %d",
 476                          cmd, WEXITSTATUS(ret));
 477         }
 478         s->smb_dir[0] = '\0';
 479     }
 480 }
 481
 482 static int slirp_smb(SlirpState* s, const char *exported_dir,
 483                      struct in_addr vserver_addr)
 484 {
 485     char smb_conf[128];
 486     char smb_cmdline[128];
 487     struct passwd *passwd;
 488     FILE *f;
 489
 490     passwd = getpwuid(geteuid());
 491     if (!passwd) {
 492         error_report("failed to retrieve user name");
 493         return -1;
 494     }
 495
 496     if (access(CONFIG_SMBD_COMMAND, F_OK)) {
 497         error_report("could not find '%s', please install it",
 498                      CONFIG_SMBD_COMMAND);
 499         return -1;
 500     }
 501
 502     if (access(exported_dir, R_OK | X_OK)) {
 503         error_report("error accessing shared directory '%s': %s",
 504                      exported_dir, strerror(errno));
 505         return -1;
 506     }
 507
 508     snprintf(s->smb_dir, sizeof(s->smb_dir), "/tmp/qemu-smb.XXXXXX");
 509     if (!mkdtemp(s->smb_dir)) {
 510         error_report("could not create samba server dir '%s'", s->smb_dir);
 511         s->smb_dir[0] = 0;
 512         return -1;
 513     }
 514     snprintf(smb_conf, sizeof(smb_conf), "%s/%s", s->smb_dir, "smb.conf");
 515
 516     f = fopen(smb_conf, "w");
 517     if (!f) {
 518         slirp_smb_cleanup(s);
 519         error_report("could not create samba server configuration file '%s'",
 520                      smb_conf);
 521         return -1;
 522     }
 523     fprintf(f,
 524             "[global]\n"
 525             "private dir=%s\n"
 526             "interfaces=127.0.0.1\n"
 527             "bind interfaces only=yes\n"
 528             "pid directory=%s\n"
 529             "lock directory=%s\n"
 530             "state directory=%s\n"
 531             "cache directory=%s\n"
 532             "ncalrpc dir=%s/ncalrpc\n"
 533             "log file=%s/log.smbd\n"
 534             "smb passwd file=%s/smbpasswd\n"
 535             "security = user\n"
 536             "map to guest = Bad User\n"
 537             "load printers = no\n"
 538             "printing = bsd\n"
 539             "disable spoolss = yes\n"
 540             "usershare max shares = 0\n"
 541             "[qemu]\n"
 542             "path=%s\n"
 543             "read only=no\n"
 544             "guest ok=yes\n"
 545             "force user=%s\n",
 546             s->smb_dir,
 547             s->smb_dir,
 548             s->smb_dir,
 549             s->smb_dir,
 550             s->smb_dir,
 551             s->smb_dir,
 552             s->smb_dir,
 553             s->smb_dir,
 554             exported_dir,
 555             passwd->pw_name
 556             );
 557     fclose(f);
 558
 559     snprintf(smb_cmdline, sizeof(smb_cmdline), "%s -l %s -s %s",
 560              CONFIG_SMBD_COMMAND, s->smb_dir, smb_conf);
 561
 562     if (slirp_add_exec(s->slirp, 0, smb_cmdline, &vserver_addr, 139) < 0 ||
 563         slirp_add_exec(s->slirp, 0, smb_cmdline, &vserver_addr, 445) < 0) {
 564         slirp_smb_cleanup(s);
 565         error_report("conflicting/invalid smbserver address");
 566         return -1;
 567     }
 568     return 0;
 569 }
 570
 571 /* automatic user mode samba server configuration (legacy interface) */
 572 int net_slirp_smb(const char *exported_dir)
 573 {
 574     struct in_addr vserver_addr = { .s_addr = 0 };
 575
 576     if (legacy_smb_export) {
 577         fprintf(stderr, "-smb given twice\n");
 578         return -1;
 579     }
 580     legacy_smb_export = exported_dir;
 581     if (!QTAILQ_EMPTY(&slirp_stacks)) {
 582         return slirp_smb(QTAILQ_FIRST(&slirp_stacks), exported_dir,
 583                          vserver_addr);
 584     }
 585     return 0;
 586 }
 587
 588 #endif /* !defined(_WIN32) */
 589
 590 struct GuestFwd {
 591     CharDriverState *hd;
 592     struct in_addr server;
 593     int port;
 594     Slirp *slirp;
 595 };
 596
 597 static int guestfwd_can_read(void *opaque)
 598 {
 599     struct GuestFwd *fwd = opaque;
 600     return slirp_socket_can_recv(fwd->slirp, fwd->server, fwd->port);
 601 }
 602
 603 static void guestfwd_read(void *opaque, const uint8_t *buf, int size)
 604 {
 605     struct GuestFwd *fwd = opaque;
 606     slirp_socket_recv(fwd->slirp, fwd->server, fwd->port, buf, size);
 607 }
 608
 609 static int slirp_guestfwd(SlirpState *s, const char *config_str,
 610                           int legacy_format)
 611 {
 612     struct in_addr server = { .s_addr = 0 };
 613     struct GuestFwd *fwd;
 614     const char *p;
 615     char buf[128];
 616     char *end;
 617     int port;
 618
 619     p = config_str;
 620     if (legacy_format) {
 621         if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 622             goto fail_syntax;
 623         }
 624     } else {
 625         if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 626             goto fail_syntax;
 627         }
 628         if (strcmp(buf, "tcp") && buf[0] != '\0') {
 629             goto fail_syntax;
 630         }
 631         if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 632             goto fail_syntax;
 633         }
 634         if (buf[0] != '\0' && !inet_aton(buf, &server)) {
 635             goto fail_syntax;
 636         }
 637         if (get_str_sep(buf, sizeof(buf), &p, '-') < 0) {
 638             goto fail_syntax;
 639         }
 640     }
 641     port = strtol(buf, &end, 10);
 642     if (*end != '\0' || port < 1 || port > 65535) {
 643         goto fail_syntax;
 644     }
 645
 646     snprintf(buf, sizeof(buf), "guestfwd.tcp.%d", port);
 647
 648     if ((strlen(p) > 4) && !strncmp(p, "cmd:", 4)) {
 649         if (slirp_add_exec(s->slirp, 0, &p[4], &server, port) < 0) {
 650             error_report("conflicting/invalid host:port in guest forwarding "
 651                          "rule '%s'", config_str);
 652             return -1;
 653         }
 654     } else {
 655         fwd = g_new(struct GuestFwd, 1);
 656         fwd->hd = qemu_chr_new(buf, p, NULL);
 657         if (!fwd->hd) {
 658             error_report("could not open guest forwarding device '%s'", buf);
 659             g_free(fwd);
 660             return -1;
 661         }
 662
 663         if (slirp_add_exec(s->slirp, 3, fwd->hd, &server, port) < 0) {
 664             error_report("conflicting/invalid host:port in guest forwarding "
 665                          "rule '%s'", config_str);
 666             g_free(fwd);
 667             return -1;
 668         }
 669         fwd->server = server;
 670         fwd->port = port;
 671         fwd->slirp = s->slirp;
 672
 673         qemu_chr_fe_claim_no_fail(fwd->hd);
 674         qemu_chr_add_handlers(fwd->hd, guestfwd_can_read, guestfwd_read,
 675                               NULL, fwd);
 676     }
 677     return 0;
 678
 679  fail_syntax:
 680     error_report("invalid guest forwarding rule '%s'", config_str);
 681     return -1;
 682 }
 683
 684 void hmp_info_usernet(Monitor *mon, const QDict *qdict)
 685 {
 686     SlirpState *s;
 687
 688     QTAILQ_FOREACH(s, &slirp_stacks, entry) {
 689         int id;
 690         bool got_vlan_id = net_hub_id_for_client(&s->nc, &id) == 0;
 691         monitor_printf(mon, "VLAN %d (%s):\n",
 692                        got_vlan_id ? id : -1,
 693                        s->nc.name);
 694         slirp_connection_info(s->slirp, mon);
 695     }
 696 }
 697
 698 static void
 699 net_init_slirp_configs(const StringList *fwd, int flags)
 700 {
 701     while (fwd) {
 702         struct slirp_config_str *config;
 703
 704         config = g_malloc0(sizeof(*config));
 705         pstrcpy(config->str, sizeof(config->str), fwd->value->str);
 706         config->flags = flags;
 707         config->next = slirp_configs;
 708         slirp_configs = config;
 709
 710         fwd = fwd->next;
 711     }
 712 }
 713
 714 static const char **slirp_dnssearch(const StringList *dnsname)
 715 {
 716     const StringList *c = dnsname;
 717     size_t i = 0, num_opts = 0;
 718     const char **ret;
 719
 720     while (c) {
 721         num_opts++;
 722         c = c->next;
 723     }
 724
 725     if (num_opts == 0) {
 726         return NULL;
 727     }
 728
 729     ret = g_malloc((num_opts + 1) * sizeof(*ret));
 730     c = dnsname;
 731     while (c) {
 732         ret[i++] = c->value->str;
 733         c = c->next;
 734     }
 735     ret[i] = NULL;
 736     return ret;
 737 }
 738
 739 int net_init_slirp(const NetClientOptions *opts, const char *name,
 740                    NetClientState *peer, Error **errp)
 741 {
 742     /* FIXME error_setg(errp, ...) on failure */
 743     struct slirp_config_str *config;
 744     char *vnet;
 745     int ret;
 746     const NetdevUserOptions *user;
 747     const char **dnssearch;
 748
 749     assert(opts->kind == NET_CLIENT_OPTIONS_KIND_USER);
 750     user = opts->user;
 751
 752     vnet = user->has_net ? g_strdup(user->net) :
 753            user->has_ip  ? g_strdup_printf("%s/24", user->ip) :
 754            NULL;
 755
 756     dnssearch = slirp_dnssearch(user->dnssearch);
 757
 758     /* all optional fields are initialized to "all bits zero" */
 759
 760     net_init_slirp_configs(user->hostfwd, SLIRP_CFG_HOSTFWD);
 761     net_init_slirp_configs(user->guestfwd, 0);
 762
 763     ret = net_slirp_init(peer, "user", name, user->q_restrict, vnet,
 764                          user->host, user->hostname, user->tftp,
 765                          user->bootfile, user->dhcpstart, user->dns, user->smb,
 766                          user->smbserver, dnssearch);
 767
 768     while (slirp_configs) {
 769         config = slirp_configs;
 770         slirp_configs = config->next;
 771         g_free(config);
 772     }
 773
 774     g_free(vnet);
 775     g_free(dnssearch);
 776
 777     return ret;
 778 }
 779
 780 int net_slirp_parse_legacy(QemuOptsList *opts_list, const char *optarg, int *ret)
 781 {
 782     if (strcmp(opts_list->name, "net") != 0 ||
 783         strncmp(optarg, "channel,", strlen("channel,")) != 0) {
 784         return 0;
 785     }
 786
 787     /* handle legacy -net channel,port:chr */
 788     optarg += strlen("channel,");
 789
 790     if (QTAILQ_EMPTY(&slirp_stacks)) {
 791         struct slirp_config_str *config;
 792
 793         config = g_malloc(sizeof(*config));
 794         pstrcpy(config->str, sizeof(config->str), optarg);
 795         config->flags = SLIRP_CFG_LEGACY;
 796         config->next = slirp_configs;
 797         slirp_configs = config;
 798         *ret = 0;
 799     } else {
 800         *ret = slirp_guestfwd(QTAILQ_FIRST(&slirp_stacks), optarg, 1);
 801     }
 802
 803     return 1;
 804 }
 805