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 #if defined(CONFIG_SMBD_COMMAND)
  31 #include <pwd.h>
  32 #include <sys/wait.h>
  33 #endif
  34 #include "net/eth.h"
  35 #include "net/net.h"
  36 #include "clients.h"
  37 #include "hub.h"
  38 #include "monitor/monitor.h"
  39 #include "qemu/error-report.h"
  40 #include "qemu/sockets.h"
  41 #include <libslirp.h>
  42 #include "chardev/char-fe.h"
  43 #include "sysemu/sysemu.h"
  44 #include "qemu/cutils.h"
  45 #include "qapi/error.h"
  46 #include "qapi/qmp/qdict.h"
  47 #include "util.h"
  48 #include "migration/register.h"
  49 #include "migration/qemu-file-types.h"
  50
  51 static int get_str_sep(char *buf, int buf_size, const char **pp, int sep)
  52 {
  53     const char *p, *p1;
  54     int len;
  55     p = *pp;
  56     p1 = strchr(p, sep);
  57     if (!p1)
  58         return -1;
  59     len = p1 - p;
  60     p1++;
  61     if (buf_size > 0) {
  62         if (len > buf_size - 1)
  63             len = buf_size - 1;
  64         memcpy(buf, p, len);
  65         buf[len] = '\0';
  66     }
  67     *pp = p1;
  68     return 0;
  69 }
  70
  71 /* slirp network adapter */
  72
  73 #define SLIRP_CFG_HOSTFWD 1
  74
  75 struct slirp_config_str {
  76     struct slirp_config_str *next;
  77     int flags;
  78     char str[1024];
  79 };
  80
  81 struct GuestFwd {
  82     CharBackend hd;
  83     struct in_addr server;
  84     int port;
  85     Slirp *slirp;
  86 };
  87
  88 typedef struct SlirpState {
  89     NetClientState nc;
  90     QTAILQ_ENTRY(SlirpState) entry;
  91     Slirp *slirp;
  92     Notifier poll_notifier;
  93     Notifier exit_notifier;
  94 #if defined(CONFIG_SMBD_COMMAND)
  95     gchar *smb_dir;
  96 #endif
  97     GSList *fwd;
  98 } SlirpState;
  99
 100 static struct slirp_config_str *slirp_configs;
 101 static QTAILQ_HEAD(, SlirpState) slirp_stacks =
 102     QTAILQ_HEAD_INITIALIZER(slirp_stacks);
 103
 104 static int slirp_hostfwd(SlirpState *s, const char *redir_str, Error **errp);
 105 static int slirp_guestfwd(SlirpState *s, const char *config_str, Error **errp);
 106
 107 #if defined(CONFIG_SMBD_COMMAND)
 108 static int slirp_smb(SlirpState *s, const char *exported_dir,
 109                      struct in_addr vserver_addr, Error **errp);
 110 static void slirp_smb_cleanup(SlirpState *s);
 111 #else
 112 static inline void slirp_smb_cleanup(SlirpState *s) { }
 113 #endif
 114
 115 static ssize_t net_slirp_send_packet(const void *pkt, size_t pkt_len,
 116                                      void *opaque)
 117 {
 118     SlirpState *s = opaque;
 119     uint8_t min_pkt[ETH_ZLEN];
 120     size_t min_pktsz = sizeof(min_pkt);
 121
 122     if (net_peer_needs_padding(&s->nc)) {
 123         if (eth_pad_short_frame(min_pkt, &min_pktsz, pkt, pkt_len)) {
 124             pkt = min_pkt;
 125             pkt_len = min_pktsz;
 126         }
 127     }
 128
 129     return qemu_send_packet(&s->nc, pkt, pkt_len);
 130 }
 131
 132 static ssize_t net_slirp_receive(NetClientState *nc, const uint8_t *buf, size_t size)
 133 {
 134     SlirpState *s = DO_UPCAST(SlirpState, nc, nc);
 135
 136     slirp_input(s->slirp, buf, size);
 137
 138     return size;
 139 }
 140
 141 static void slirp_smb_exit(Notifier *n, void *data)
 142 {
 143     SlirpState *s = container_of(n, SlirpState, exit_notifier);
 144     slirp_smb_cleanup(s);
 145 }
 146
 147 static void slirp_free_fwd(gpointer data)
 148 {
 149     struct GuestFwd *fwd = data;
 150
 151     qemu_chr_fe_deinit(&fwd->hd, true);
 152     g_free(data);
 153 }
 154
 155 static void net_slirp_cleanup(NetClientState *nc)
 156 {
 157     SlirpState *s = DO_UPCAST(SlirpState, nc, nc);
 158
 159     g_slist_free_full(s->fwd, slirp_free_fwd);
 160     main_loop_poll_remove_notifier(&s->poll_notifier);
 161     unregister_savevm(NULL, "slirp", s->slirp);
 162     slirp_cleanup(s->slirp);
 163     if (s->exit_notifier.notify) {
 164         qemu_remove_exit_notifier(&s->exit_notifier);
 165     }
 166     slirp_smb_cleanup(s);
 167     QTAILQ_REMOVE(&slirp_stacks, s, entry);
 168 }
 169
 170 static NetClientInfo net_slirp_info = {
 171     .type = NET_CLIENT_DRIVER_USER,
 172     .size = sizeof(SlirpState),
 173     .receive = net_slirp_receive,
 174     .cleanup = net_slirp_cleanup,
 175 };
 176
 177 static void net_slirp_guest_error(const char *msg, void *opaque)
 178 {
 179     qemu_log_mask(LOG_GUEST_ERROR, "%s", msg);
 180 }
 181
 182 static int64_t net_slirp_clock_get_ns(void *opaque)
 183 {
 184     return qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
 185 }
 186
 187 typedef struct SlirpTimer SlirpTimer;
 188 struct SlirpTimer {
 189     QEMUTimer timer;
 190 #if SLIRP_CHECK_VERSION(4,7,0)
 191     Slirp *slirp;
 192     SlirpTimerId id;
 193     void *cb_opaque;
 194 #endif
 195 };
 196
 197 #if SLIRP_CHECK_VERSION(4,7,0)
 198 static void net_slirp_init_completed(Slirp *slirp, void *opaque)
 199 {
 200     SlirpState *s = opaque;
 201     s->slirp = slirp;
 202 }
 203
 204 static void net_slirp_timer_cb(void *opaque)
 205 {
 206     SlirpTimer *t = opaque;
 207     slirp_handle_timer(t->slirp, t->id, t->cb_opaque);
 208 }
 209
 210 static void *net_slirp_timer_new_opaque(SlirpTimerId id,
 211                                         void *cb_opaque, void *opaque)
 212 {
 213     SlirpState *s = opaque;
 214     SlirpTimer *t = g_new(SlirpTimer, 1);
 215     t->slirp = s->slirp;
 216     t->id = id;
 217     t->cb_opaque = cb_opaque;
 218     timer_init_full(&t->timer, NULL, QEMU_CLOCK_VIRTUAL,
 219                     SCALE_MS, QEMU_TIMER_ATTR_EXTERNAL,
 220                     net_slirp_timer_cb, t);
 221     return t;
 222 }
 223 #else
 224 static void *net_slirp_timer_new(SlirpTimerCb cb,
 225                                  void *cb_opaque, void *opaque)
 226 {
 227     SlirpTimer *t = g_new(SlirpTimer, 1);
 228     timer_init_full(&t->timer, NULL, QEMU_CLOCK_VIRTUAL,
 229                     SCALE_MS, QEMU_TIMER_ATTR_EXTERNAL,
 230                     cb, cb_opaque);
 231     return t;
 232 }
 233 #endif
 234
 235 static void net_slirp_timer_free(void *timer, void *opaque)
 236 {
 237     SlirpTimer *t = timer;
 238     timer_del(&t->timer);
 239     g_free(t);
 240 }
 241
 242 static void net_slirp_timer_mod(void *timer, int64_t expire_timer,
 243                                 void *opaque)
 244 {
 245     SlirpTimer *t = timer;
 246     timer_mod(&t->timer, expire_timer);
 247 }
 248
 249 static void net_slirp_register_poll_fd(int fd, void *opaque)
 250 {
 251     qemu_fd_register(fd);
 252 }
 253
 254 static void net_slirp_unregister_poll_fd(int fd, void *opaque)
 255 {
 256     /* no qemu_fd_unregister */
 257 }
 258
 259 static void net_slirp_notify(void *opaque)
 260 {
 261     qemu_notify_event();
 262 }
 263
 264 static const SlirpCb slirp_cb = {
 265     .send_packet = net_slirp_send_packet,
 266     .guest_error = net_slirp_guest_error,
 267     .clock_get_ns = net_slirp_clock_get_ns,
 268 #if SLIRP_CHECK_VERSION(4,7,0)
 269     .init_completed = net_slirp_init_completed,
 270     .timer_new_opaque = net_slirp_timer_new_opaque,
 271 #else
 272     .timer_new = net_slirp_timer_new,
 273 #endif
 274     .timer_free = net_slirp_timer_free,
 275     .timer_mod = net_slirp_timer_mod,
 276     .register_poll_fd = net_slirp_register_poll_fd,
 277     .unregister_poll_fd = net_slirp_unregister_poll_fd,
 278     .notify = net_slirp_notify,
 279 };
 280
 281 static int slirp_poll_to_gio(int events)
 282 {
 283     int ret = 0;
 284
 285     if (events & SLIRP_POLL_IN) {
 286         ret |= G_IO_IN;
 287     }
 288     if (events & SLIRP_POLL_OUT) {
 289         ret |= G_IO_OUT;
 290     }
 291     if (events & SLIRP_POLL_PRI) {
 292         ret |= G_IO_PRI;
 293     }
 294     if (events & SLIRP_POLL_ERR) {
 295         ret |= G_IO_ERR;
 296     }
 297     if (events & SLIRP_POLL_HUP) {
 298         ret |= G_IO_HUP;
 299     }
 300
 301     return ret;
 302 }
 303
 304 static int net_slirp_add_poll(int fd, int events, void *opaque)
 305 {
 306     GArray *pollfds = opaque;
 307     GPollFD pfd = {
 308         .fd = fd,
 309         .events = slirp_poll_to_gio(events),
 310     };
 311     int idx = pollfds->len;
 312     g_array_append_val(pollfds, pfd);
 313     return idx;
 314 }
 315
 316 static int slirp_gio_to_poll(int events)
 317 {
 318     int ret = 0;
 319
 320     if (events & G_IO_IN) {
 321         ret |= SLIRP_POLL_IN;
 322     }
 323     if (events & G_IO_OUT) {
 324         ret |= SLIRP_POLL_OUT;
 325     }
 326     if (events & G_IO_PRI) {
 327         ret |= SLIRP_POLL_PRI;
 328     }
 329     if (events & G_IO_ERR) {
 330         ret |= SLIRP_POLL_ERR;
 331     }
 332     if (events & G_IO_HUP) {
 333         ret |= SLIRP_POLL_HUP;
 334     }
 335
 336     return ret;
 337 }
 338
 339 static int net_slirp_get_revents(int idx, void *opaque)
 340 {
 341     GArray *pollfds = opaque;
 342
 343     return slirp_gio_to_poll(g_array_index(pollfds, GPollFD, idx).revents);
 344 }
 345
 346 static void net_slirp_poll_notify(Notifier *notifier, void *data)
 347 {
 348     MainLoopPoll *poll = data;
 349     SlirpState *s = container_of(notifier, SlirpState, poll_notifier);
 350
 351     switch (poll->state) {
 352     case MAIN_LOOP_POLL_FILL:
 353         slirp_pollfds_fill(s->slirp, &poll->timeout,
 354                            net_slirp_add_poll, poll->pollfds);
 355         break;
 356     case MAIN_LOOP_POLL_OK:
 357     case MAIN_LOOP_POLL_ERR:
 358         slirp_pollfds_poll(s->slirp, poll->state == MAIN_LOOP_POLL_ERR,
 359                            net_slirp_get_revents, poll->pollfds);
 360         break;
 361     default:
 362         g_assert_not_reached();
 363     }
 364 }
 365
 366 static ssize_t
 367 net_slirp_stream_read(void *buf, size_t size, void *opaque)
 368 {
 369     QEMUFile *f = opaque;
 370
 371     return qemu_get_buffer(f, buf, size);
 372 }
 373
 374 static ssize_t
 375 net_slirp_stream_write(const void *buf, size_t size, void *opaque)
 376 {
 377     QEMUFile *f = opaque;
 378
 379     qemu_put_buffer(f, buf, size);
 380     if (qemu_file_get_error(f)) {
 381         return -1;
 382     }
 383
 384     return size;
 385 }
 386
 387 static int net_slirp_state_load(QEMUFile *f, void *opaque, int version_id)
 388 {
 389     Slirp *slirp = opaque;
 390
 391     return slirp_state_load(slirp, version_id, net_slirp_stream_read, f);
 392 }
 393
 394 static void net_slirp_state_save(QEMUFile *f, void *opaque)
 395 {
 396     Slirp *slirp = opaque;
 397
 398     slirp_state_save(slirp, net_slirp_stream_write, f);
 399 }
 400
 401 static SaveVMHandlers savevm_slirp_state = {
 402     .save_state = net_slirp_state_save,
 403     .load_state = net_slirp_state_load,
 404 };
 405
 406 static int net_slirp_init(NetClientState *peer, const char *model,
 407                           const char *name, int restricted,
 408                           bool ipv4, const char *vnetwork, const char *vhost,
 409                           bool ipv6, const char *vprefix6, int vprefix6_len,
 410                           const char *vhost6,
 411                           const char *vhostname, const char *tftp_export,
 412                           const char *bootfile, const char *vdhcp_start,
 413                           const char *vnameserver, const char *vnameserver6,
 414                           const char *smb_export, const char *vsmbserver,
 415                           const char **dnssearch, const char *vdomainname,
 416                           const char *tftp_server_name,
 417                           Error **errp)
 418 {
 419     /* default settings according to historic slirp */
 420     struct in_addr net  = { .s_addr = htonl(0x0a000200) }; /* 10.0.2.0 */
 421     struct in_addr mask = { .s_addr = htonl(0xffffff00) }; /* 255.255.255.0 */
 422     struct in_addr host = { .s_addr = htonl(0x0a000202) }; /* 10.0.2.2 */
 423     struct in_addr dhcp = { .s_addr = htonl(0x0a00020f) }; /* 10.0.2.15 */
 424     struct in_addr dns  = { .s_addr = htonl(0x0a000203) }; /* 10.0.2.3 */
 425     struct in6_addr ip6_prefix;
 426     struct in6_addr ip6_host;
 427     struct in6_addr ip6_dns;
 428 #if defined(CONFIG_SMBD_COMMAND)
 429     struct in_addr smbsrv = { .s_addr = 0 };
 430 #endif
 431     SlirpConfig cfg = { 0 };
 432     NetClientState *nc;
 433     SlirpState *s;
 434     char buf[20];
 435     uint32_t addr;
 436     int shift;
 437     char *end;
 438     struct slirp_config_str *config;
 439
 440     if (!ipv4 && (vnetwork || vhost || vnameserver)) {
 441         error_setg(errp, "IPv4 disabled but netmask/host/dns provided");
 442         return -1;
 443     }
 444
 445     if (!ipv6 && (vprefix6 || vhost6 || vnameserver6)) {
 446         error_setg(errp, "IPv6 disabled but prefix/host6/dns6 provided");
 447         return -1;
 448     }
 449
 450     if (!ipv4 && !ipv6) {
 451         /* It doesn't make sense to disable both */
 452         error_setg(errp, "IPv4 and IPv6 disabled");
 453         return -1;
 454     }
 455
 456     if (vnetwork) {
 457         if (get_str_sep(buf, sizeof(buf), &vnetwork, '/') < 0) {
 458             if (!inet_aton(vnetwork, &net)) {
 459                 error_setg(errp, "Failed to parse netmask");
 460                 return -1;
 461             }
 462             addr = ntohl(net.s_addr);
 463             if (!(addr & 0x80000000)) {
 464                 mask.s_addr = htonl(0xff000000); /* class A */
 465             } else if ((addr & 0xfff00000) == 0xac100000) {
 466                 mask.s_addr = htonl(0xfff00000); /* priv. 172.16.0.0/12 */
 467             } else if ((addr & 0xc0000000) == 0x80000000) {
 468                 mask.s_addr = htonl(0xffff0000); /* class B */
 469             } else if ((addr & 0xffff0000) == 0xc0a80000) {
 470                 mask.s_addr = htonl(0xffff0000); /* priv. 192.168.0.0/16 */
 471             } else if ((addr & 0xffff0000) == 0xc6120000) {
 472                 mask.s_addr = htonl(0xfffe0000); /* tests 198.18.0.0/15 */
 473             } else if ((addr & 0xe0000000) == 0xe0000000) {
 474                 mask.s_addr = htonl(0xffffff00); /* class C */
 475             } else {
 476                 mask.s_addr = htonl(0xfffffff0); /* multicast/reserved */
 477             }
 478         } else {
 479             if (!inet_aton(buf, &net)) {
 480                 error_setg(errp, "Failed to parse netmask");
 481                 return -1;
 482             }
 483             shift = strtol(vnetwork, &end, 10);
 484             if (*end != '\0') {
 485                 if (!inet_aton(vnetwork, &mask)) {
 486                     error_setg(errp,
 487                                "Failed to parse netmask (trailing chars)");
 488                     return -1;
 489                 }
 490             } else if (shift < 4 || shift > 32) {
 491                 error_setg(errp,
 492                            "Invalid netmask provided (must be in range 4-32)");
 493                 return -1;
 494             } else {
 495                 mask.s_addr = htonl(0xffffffff << (32 - shift));
 496             }
 497         }
 498         net.s_addr &= mask.s_addr;
 499         host.s_addr = net.s_addr | (htonl(0x0202) & ~mask.s_addr);
 500         dhcp.s_addr = net.s_addr | (htonl(0x020f) & ~mask.s_addr);
 501         dns.s_addr  = net.s_addr | (htonl(0x0203) & ~mask.s_addr);
 502     }
 503
 504     if (vhost && !inet_aton(vhost, &host)) {
 505         error_setg(errp, "Failed to parse host");
 506         return -1;
 507     }
 508     if ((host.s_addr & mask.s_addr) != net.s_addr) {
 509         error_setg(errp, "Host doesn't belong to network");
 510         return -1;
 511     }
 512
 513     if (vnameserver && !inet_aton(vnameserver, &dns)) {
 514         error_setg(errp, "Failed to parse DNS");
 515         return -1;
 516     }
 517     if (restricted && (dns.s_addr & mask.s_addr) != net.s_addr) {
 518         error_setg(errp, "DNS doesn't belong to network");
 519         return -1;
 520     }
 521     if (dns.s_addr == host.s_addr) {
 522         error_setg(errp, "DNS must be different from host");
 523         return -1;
 524     }
 525
 526     if (vdhcp_start && !inet_aton(vdhcp_start, &dhcp)) {
 527         error_setg(errp, "Failed to parse DHCP start address");
 528         return -1;
 529     }
 530     if ((dhcp.s_addr & mask.s_addr) != net.s_addr) {
 531         error_setg(errp, "DHCP doesn't belong to network");
 532         return -1;
 533     }
 534     if (dhcp.s_addr == host.s_addr || dhcp.s_addr == dns.s_addr) {
 535         error_setg(errp, "DHCP must be different from host and DNS");
 536         return -1;
 537     }
 538
 539 #if defined(CONFIG_SMBD_COMMAND)
 540     if (vsmbserver && !inet_aton(vsmbserver, &smbsrv)) {
 541         error_setg(errp, "Failed to parse SMB address");
 542         return -1;
 543     }
 544 #endif
 545
 546     if (!vprefix6) {
 547         vprefix6 = "fec0::";
 548     }
 549     if (!inet_pton(AF_INET6, vprefix6, &ip6_prefix)) {
 550         error_setg(errp, "Failed to parse IPv6 prefix");
 551         return -1;
 552     }
 553
 554     if (!vprefix6_len) {
 555         vprefix6_len = 64;
 556     }
 557     if (vprefix6_len < 0 || vprefix6_len > 126) {
 558         error_setg(errp,
 559                    "Invalid IPv6 prefix provided "
 560                    "(IPv6 prefix length must be between 0 and 126)");
 561         return -1;
 562     }
 563
 564     if (vhost6) {
 565         if (!inet_pton(AF_INET6, vhost6, &ip6_host)) {
 566             error_setg(errp, "Failed to parse IPv6 host");
 567             return -1;
 568         }
 569         if (!in6_equal_net(&ip6_prefix, &ip6_host, vprefix6_len)) {
 570             error_setg(errp, "IPv6 Host doesn't belong to network");
 571             return -1;
 572         }
 573     } else {
 574         ip6_host = ip6_prefix;
 575         ip6_host.s6_addr[15] |= 2;
 576     }
 577
 578     if (vnameserver6) {
 579         if (!inet_pton(AF_INET6, vnameserver6, &ip6_dns)) {
 580             error_setg(errp, "Failed to parse IPv6 DNS");
 581             return -1;
 582         }
 583         if (restricted && !in6_equal_net(&ip6_prefix, &ip6_dns, vprefix6_len)) {
 584             error_setg(errp, "IPv6 DNS doesn't belong to network");
 585             return -1;
 586         }
 587     } else {
 588         ip6_dns = ip6_prefix;
 589         ip6_dns.s6_addr[15] |= 3;
 590     }
 591
 592     if (vdomainname && !*vdomainname) {
 593         error_setg(errp, "'domainname' parameter cannot be empty");
 594         return -1;
 595     }
 596
 597     if (vdomainname && strlen(vdomainname) > 255) {
 598         error_setg(errp, "'domainname' parameter cannot exceed 255 bytes");
 599         return -1;
 600     }
 601
 602     if (vhostname && strlen(vhostname) > 255) {
 603         error_setg(errp, "'vhostname' parameter cannot exceed 255 bytes");
 604         return -1;
 605     }
 606
 607     if (tftp_server_name && strlen(tftp_server_name) > 255) {
 608         error_setg(errp, "'tftp-server-name' parameter cannot exceed 255 bytes");
 609         return -1;
 610     }
 611
 612     nc = qemu_new_net_client(&net_slirp_info, peer, model, name);
 613
 614     qemu_set_info_str(nc, "net=%s,restrict=%s", inet_ntoa(net),
 615                       restricted ? "on" : "off");
 616
 617     s = DO_UPCAST(SlirpState, nc, nc);
 618
 619     cfg.version = SLIRP_CHECK_VERSION(4,7,0) ? 4 : 1;
 620     cfg.restricted = restricted;
 621     cfg.in_enabled = ipv4;
 622     cfg.vnetwork = net;
 623     cfg.vnetmask = mask;
 624     cfg.vhost = host;
 625     cfg.in6_enabled = ipv6;
 626     cfg.vprefix_addr6 = ip6_prefix;
 627     cfg.vprefix_len = vprefix6_len;
 628     cfg.vhost6 = ip6_host;
 629     cfg.vhostname = vhostname;
 630     cfg.tftp_server_name = tftp_server_name;
 631     cfg.tftp_path = tftp_export;
 632     cfg.bootfile = bootfile;
 633     cfg.vdhcp_start = dhcp;
 634     cfg.vnameserver = dns;
 635     cfg.vnameserver6 = ip6_dns;
 636     cfg.vdnssearch = dnssearch;
 637     cfg.vdomainname = vdomainname;
 638     s->slirp = slirp_new(&cfg, &slirp_cb, s);
 639     QTAILQ_INSERT_TAIL(&slirp_stacks, s, entry);
 640
 641     /*
 642      * Make sure the current bitstream version of slirp is 4, to avoid
 643      * QEMU migration incompatibilities, if upstream slirp bumped the
 644      * version.
 645      *
 646      * FIXME: use bitfields of features? teach libslirp to save with
 647      * specific version?
 648      */
 649     g_assert(slirp_state_version() == 4);
 650     register_savevm_live("slirp", 0, slirp_state_version(),
 651                          &savevm_slirp_state, s->slirp);
 652
 653     s->poll_notifier.notify = net_slirp_poll_notify;
 654     main_loop_poll_add_notifier(&s->poll_notifier);
 655
 656     for (config = slirp_configs; config; config = config->next) {
 657         if (config->flags & SLIRP_CFG_HOSTFWD) {
 658             if (slirp_hostfwd(s, config->str, errp) < 0) {
 659                 goto error;
 660             }
 661         } else {
 662             if (slirp_guestfwd(s, config->str, errp) < 0) {
 663                 goto error;
 664             }
 665         }
 666     }
 667 #if defined(CONFIG_SMBD_COMMAND)
 668     if (smb_export) {
 669         if (slirp_smb(s, smb_export, smbsrv, errp) < 0) {
 670             goto error;
 671         }
 672     }
 673 #endif
 674
 675     s->exit_notifier.notify = slirp_smb_exit;
 676     qemu_add_exit_notifier(&s->exit_notifier);
 677     return 0;
 678
 679 error:
 680     qemu_del_net_client(nc);
 681     return -1;
 682 }
 683
 684 static SlirpState *slirp_lookup(Monitor *mon, const char *id)
 685 {
 686     if (id) {
 687         NetClientState *nc = qemu_find_netdev(id);
 688         if (!nc) {
 689             monitor_printf(mon, "unrecognized netdev id '%s'\n", id);
 690             return NULL;
 691         }
 692         if (strcmp(nc->model, "user")) {
 693             monitor_printf(mon, "invalid device specified\n");
 694             return NULL;
 695         }
 696         return DO_UPCAST(SlirpState, nc, nc);
 697     } else {
 698         if (QTAILQ_EMPTY(&slirp_stacks)) {
 699             monitor_printf(mon, "user mode network stack not in use\n");
 700             return NULL;
 701         }
 702         return QTAILQ_FIRST(&slirp_stacks);
 703     }
 704 }
 705
 706 void hmp_hostfwd_remove(Monitor *mon, const QDict *qdict)
 707 {
 708     struct in_addr host_addr = { .s_addr = INADDR_ANY };
 709     int host_port;
 710     char buf[256];
 711     const char *src_str, *p;
 712     SlirpState *s;
 713     int is_udp = 0;
 714     int err;
 715     const char *arg1 = qdict_get_str(qdict, "arg1");
 716     const char *arg2 = qdict_get_try_str(qdict, "arg2");
 717
 718     if (arg2) {
 719         s = slirp_lookup(mon, arg1);
 720         src_str = arg2;
 721     } else {
 722         s = slirp_lookup(mon, NULL);
 723         src_str = arg1;
 724     }
 725     if (!s) {
 726         return;
 727     }
 728
 729     p = src_str;
 730     if (!p || get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 731         goto fail_syntax;
 732     }
 733
 734     if (!strcmp(buf, "tcp") || buf[0] == '\0') {
 735         is_udp = 0;
 736     } else if (!strcmp(buf, "udp")) {
 737         is_udp = 1;
 738     } else {
 739         goto fail_syntax;
 740     }
 741
 742     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 743         goto fail_syntax;
 744     }
 745     if (buf[0] != '\0' && !inet_aton(buf, &host_addr)) {
 746         goto fail_syntax;
 747     }
 748
 749     if (qemu_strtoi(p, NULL, 10, &host_port)) {
 750         goto fail_syntax;
 751     }
 752
 753     err = slirp_remove_hostfwd(s->slirp, is_udp, host_addr, host_port);
 754
 755     monitor_printf(mon, "host forwarding rule for %s %s\n", src_str,
 756                    err ? "not found" : "removed");
 757     return;
 758
 759  fail_syntax:
 760     monitor_printf(mon, "invalid format\n");
 761 }
 762
 763 static int slirp_hostfwd(SlirpState *s, const char *redir_str, Error **errp)
 764 {
 765     struct in_addr host_addr = { .s_addr = INADDR_ANY };
 766     struct in_addr guest_addr = { .s_addr = 0 };
 767     int host_port, guest_port;
 768     const char *p;
 769     char buf[256];
 770     int is_udp;
 771     char *end;
 772     const char *fail_reason = "Unknown reason";
 773
 774     p = redir_str;
 775     if (!p || get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 776         fail_reason = "No : separators";
 777         goto fail_syntax;
 778     }
 779     if (!strcmp(buf, "tcp") || buf[0] == '\0') {
 780         is_udp = 0;
 781     } else if (!strcmp(buf, "udp")) {
 782         is_udp = 1;
 783     } else {
 784         fail_reason = "Bad protocol name";
 785         goto fail_syntax;
 786     }
 787
 788     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 789         fail_reason = "Missing : separator";
 790         goto fail_syntax;
 791     }
 792     if (buf[0] != '\0' && !inet_aton(buf, &host_addr)) {
 793         fail_reason = "Bad host address";
 794         goto fail_syntax;
 795     }
 796
 797     if (get_str_sep(buf, sizeof(buf), &p, '-') < 0) {
 798         fail_reason = "Bad host port separator";
 799         goto fail_syntax;
 800     }
 801     host_port = strtol(buf, &end, 0);
 802     if (*end != '\0' || host_port < 0 || host_port > 65535) {
 803         fail_reason = "Bad host port";
 804         goto fail_syntax;
 805     }
 806
 807     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
 808         fail_reason = "Missing guest address";
 809         goto fail_syntax;
 810     }
 811     if (buf[0] != '\0' && !inet_aton(buf, &guest_addr)) {
 812         fail_reason = "Bad guest address";
 813         goto fail_syntax;
 814     }
 815
 816     guest_port = strtol(p, &end, 0);
 817     if (*end != '\0' || guest_port < 1 || guest_port > 65535) {
 818         fail_reason = "Bad guest port";
 819         goto fail_syntax;
 820     }
 821
 822     if (slirp_add_hostfwd(s->slirp, is_udp, host_addr, host_port, guest_addr,
 823                           guest_port) < 0) {
 824         error_setg(errp, "Could not set up host forwarding rule '%s'",
 825                    redir_str);
 826         return -1;
 827     }
 828     return 0;
 829
 830  fail_syntax:
 831     error_setg(errp, "Invalid host forwarding rule '%s' (%s)", redir_str,
 832                fail_reason);
 833     return -1;
 834 }
 835
 836 void hmp_hostfwd_add(Monitor *mon, const QDict *qdict)
 837 {
 838     const char *redir_str;
 839     SlirpState *s;
 840     const char *arg1 = qdict_get_str(qdict, "arg1");
 841     const char *arg2 = qdict_get_try_str(qdict, "arg2");
 842
 843     if (arg2) {
 844         s = slirp_lookup(mon, arg1);
 845         redir_str = arg2;
 846     } else {
 847         s = slirp_lookup(mon, NULL);
 848         redir_str = arg1;
 849     }
 850     if (s) {
 851         Error *err = NULL;
 852         if (slirp_hostfwd(s, redir_str, &err) < 0) {
 853             error_report_err(err);
 854         }
 855     }
 856
 857 }
 858
 859 #if defined(CONFIG_SMBD_COMMAND)
 860
 861 /* automatic user mode samba server configuration */
 862 static void slirp_smb_cleanup(SlirpState *s)
 863 {
 864     int ret;
 865
 866     if (s->smb_dir) {
 867         gchar *cmd = g_strdup_printf("rm -rf %s", s->smb_dir);
 868         ret = system(cmd);
 869         if (ret == -1 || !WIFEXITED(ret)) {
 870             error_report("'%s' failed.", cmd);
 871         } else if (WEXITSTATUS(ret)) {
 872             error_report("'%s' failed. Error code: %d",
 873                          cmd, WEXITSTATUS(ret));
 874         }
 875         g_free(cmd);
 876         g_free(s->smb_dir);
 877         s->smb_dir = NULL;
 878     }
 879 }
 880
 881 static int slirp_smb(SlirpState* s, const char *exported_dir,
 882                      struct in_addr vserver_addr, Error **errp)
 883 {
 884     char *smb_conf;
 885     char *smb_cmdline;
 886     struct passwd *passwd;
 887     FILE *f;
 888
 889     passwd = getpwuid(geteuid());
 890     if (!passwd) {
 891         error_setg(errp, "Failed to retrieve user name");
 892         return -1;
 893     }
 894
 895     if (access(CONFIG_SMBD_COMMAND, F_OK)) {
 896         error_setg(errp, "Could not find '%s', please install it",
 897                    CONFIG_SMBD_COMMAND);
 898         return -1;
 899     }
 900
 901     if (access(exported_dir, R_OK | X_OK)) {
 902         error_setg(errp, "Error accessing shared directory '%s': %s",
 903                    exported_dir, strerror(errno));
 904         return -1;
 905     }
 906
 907     s->smb_dir = g_dir_make_tmp("qemu-smb.XXXXXX", NULL);
 908     if (!s->smb_dir) {
 909         error_setg(errp, "Could not create samba server dir");
 910         return -1;
 911     }
 912     smb_conf = g_strdup_printf("%s/%s", s->smb_dir, "smb.conf");
 913
 914     f = fopen(smb_conf, "w");
 915     if (!f) {
 916         slirp_smb_cleanup(s);
 917         error_setg(errp,
 918                    "Could not create samba server configuration file '%s'",
 919                     smb_conf);
 920         g_free(smb_conf);
 921         return -1;
 922     }
 923     fprintf(f,
 924             "[global]\n"
 925             "private dir=%s\n"
 926             "interfaces=127.0.0.1\n"
 927             "bind interfaces only=yes\n"
 928             "pid directory=%s\n"
 929             "lock directory=%s\n"
 930             "state directory=%s\n"
 931             "cache directory=%s\n"
 932             "ncalrpc dir=%s/ncalrpc\n"
 933             "log file=%s/log.smbd\n"
 934             "smb passwd file=%s/smbpasswd\n"
 935             "security = user\n"
 936             "map to guest = Bad User\n"
 937             "load printers = no\n"
 938             "printing = bsd\n"
 939             "disable spoolss = yes\n"
 940             "usershare max shares = 0\n"
 941             "[qemu]\n"
 942             "path=%s\n"
 943             "read only=no\n"
 944             "guest ok=yes\n"
 945             "force user=%s\n",
 946             s->smb_dir,
 947             s->smb_dir,
 948             s->smb_dir,
 949             s->smb_dir,
 950             s->smb_dir,
 951             s->smb_dir,
 952             s->smb_dir,
 953             s->smb_dir,
 954             exported_dir,
 955             passwd->pw_name
 956             );
 957     fclose(f);
 958
 959     smb_cmdline = g_strdup_printf("%s -l %s -s %s",
 960              CONFIG_SMBD_COMMAND, s->smb_dir, smb_conf);
 961     g_free(smb_conf);
 962
 963     if (slirp_add_exec(s->slirp, smb_cmdline, &vserver_addr, 139) < 0 ||
 964         slirp_add_exec(s->slirp, smb_cmdline, &vserver_addr, 445) < 0) {
 965         slirp_smb_cleanup(s);
 966         g_free(smb_cmdline);
 967         error_setg(errp, "Conflicting/invalid smbserver address");
 968         return -1;
 969     }
 970     g_free(smb_cmdline);
 971     return 0;
 972 }
 973
 974 #endif /* defined(CONFIG_SMBD_COMMAND) */
 975
 976 static int guestfwd_can_read(void *opaque)
 977 {
 978     struct GuestFwd *fwd = opaque;
 979     return slirp_socket_can_recv(fwd->slirp, fwd->server, fwd->port);
 980 }
 981
 982 static void guestfwd_read(void *opaque, const uint8_t *buf, int size)
 983 {
 984     struct GuestFwd *fwd = opaque;
 985     slirp_socket_recv(fwd->slirp, fwd->server, fwd->port, buf, size);
 986 }
 987
 988 static ssize_t guestfwd_write(const void *buf, size_t len, void *chr)
 989 {
 990     return qemu_chr_fe_write_all(chr, buf, len);
 991 }
 992
 993 static int slirp_guestfwd(SlirpState *s, const char *config_str, Error **errp)
 994 {
 995     /* TODO: IPv6 */
 996     struct in_addr server = { .s_addr = 0 };
 997     struct GuestFwd *fwd;
 998     const char *p;
 999     char buf[128];
1000     char *end;
1001     int port;
1002
1003     p = config_str;
1004     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
1005         goto fail_syntax;
1006     }
1007     if (strcmp(buf, "tcp") && buf[0] != '\0') {
1008         goto fail_syntax;
1009     }
1010     if (get_str_sep(buf, sizeof(buf), &p, ':') < 0) {
1011         goto fail_syntax;
1012     }
1013     if (buf[0] != '\0' && !inet_aton(buf, &server)) {
1014         goto fail_syntax;
1015     }
1016     if (get_str_sep(buf, sizeof(buf), &p, '-') < 0) {
1017         goto fail_syntax;
1018     }
1019     port = strtol(buf, &end, 10);
1020     if (*end != '\0' || port < 1 || port > 65535) {
1021         goto fail_syntax;
1022     }
1023
1024     snprintf(buf, sizeof(buf), "guestfwd.tcp.%d", port);
1025
1026     if (g_str_has_prefix(p, "cmd:")) {
1027         if (slirp_add_exec(s->slirp, &p[4], &server, port) < 0) {
1028             error_setg(errp, "Conflicting/invalid host:port in guest "
1029                        "forwarding rule '%s'", config_str);
1030             return -1;
1031         }
1032     } else {
1033         Error *err = NULL;
1034         /*
1035          * FIXME: sure we want to support implicit
1036          * muxed monitors here?
1037          */
1038         Chardev *chr = qemu_chr_new_mux_mon(buf, p, NULL);
1039
1040         if (!chr) {
1041             error_setg(errp, "Could not open guest forwarding device '%s'",
1042                        buf);
1043             return -1;
1044         }
1045
1046         fwd = g_new(struct GuestFwd, 1);
1047         qemu_chr_fe_init(&fwd->hd, chr, &err);
1048         if (err) {
1049             error_propagate(errp, err);
1050             object_unparent(OBJECT(chr));
1051             g_free(fwd);
1052             return -1;
1053         }
1054
1055         if (slirp_add_guestfwd(s->slirp, guestfwd_write, &fwd->hd,
1056                                &server, port) < 0) {
1057             error_setg(errp, "Conflicting/invalid host:port in guest "
1058                        "forwarding rule '%s'", config_str);
1059             qemu_chr_fe_deinit(&fwd->hd, true);
1060             g_free(fwd);
1061             return -1;
1062         }
1063         fwd->server = server;
1064         fwd->port = port;
1065         fwd->slirp = s->slirp;
1066
1067         qemu_chr_fe_set_handlers(&fwd->hd, guestfwd_can_read, guestfwd_read,
1068                                  NULL, NULL, fwd, NULL, true);
1069         s->fwd = g_slist_append(s->fwd, fwd);
1070     }
1071     return 0;
1072
1073  fail_syntax:
1074     error_setg(errp, "Invalid guest forwarding rule '%s'", config_str);
1075     return -1;
1076 }
1077
1078 void hmp_info_usernet(Monitor *mon, const QDict *qdict)
1079 {
1080     SlirpState *s;
1081
1082     QTAILQ_FOREACH(s, &slirp_stacks, entry) {
1083         int id;
1084         bool got_hub_id = net_hub_id_for_client(&s->nc, &id) == 0;
1085         char *info = slirp_connection_info(s->slirp);
1086         monitor_printf(mon, "Hub %d (%s):\n%s",
1087                        got_hub_id ? id : -1,
1088                        s->nc.name, info);
1089         g_free(info);
1090     }
1091 }
1092
1093 static void
1094 net_init_slirp_configs(const StringList *fwd, int flags)
1095 {
1096     while (fwd) {
1097         struct slirp_config_str *config;
1098
1099         config = g_malloc0(sizeof(*config));
1100         pstrcpy(config->str, sizeof(config->str), fwd->value->str);
1101         config->flags = flags;
1102         config->next = slirp_configs;
1103         slirp_configs = config;
1104
1105         fwd = fwd->next;
1106     }
1107 }
1108
1109 static const char **slirp_dnssearch(const StringList *dnsname)
1110 {
1111     const StringList *c = dnsname;
1112     size_t i = 0, num_opts = 0;
1113     const char **ret;
1114
1115     while (c) {
1116         num_opts++;
1117         c = c->next;
1118     }
1119
1120     if (num_opts == 0) {
1121         return NULL;
1122     }
1123
1124     ret = g_malloc((num_opts + 1) * sizeof(*ret));
1125     c = dnsname;
1126     while (c) {
1127         ret[i++] = c->value->str;
1128         c = c->next;
1129     }
1130     ret[i] = NULL;
1131     return ret;
1132 }
1133
1134 int net_init_slirp(const Netdev *netdev, const char *name,
1135                    NetClientState *peer, Error **errp)
1136 {
1137     struct slirp_config_str *config;
1138     char *vnet;
1139     int ret;
1140     const NetdevUserOptions *user;
1141     const char **dnssearch;
1142     bool ipv4 = true, ipv6 = true;
1143
1144     assert(netdev->type == NET_CLIENT_DRIVER_USER);
1145     user = &netdev->u.user;
1146
1147     if ((user->has_ipv6 && user->ipv6 && !user->has_ipv4) ||
1148         (user->has_ipv4 && !user->ipv4)) {
1149         ipv4 = 0;
1150     }
1151     if ((user->has_ipv4 && user->ipv4 && !user->has_ipv6) ||
1152         (user->has_ipv6 && !user->ipv6)) {
1153         ipv6 = 0;
1154     }
1155
1156     vnet = user->has_net ? g_strdup(user->net) :
1157            user->has_ip  ? g_strdup_printf("%s/24", user->ip) :
1158            NULL;
1159
1160     dnssearch = slirp_dnssearch(user->dnssearch);
1161
1162     /* all optional fields are initialized to "all bits zero" */
1163
1164     net_init_slirp_configs(user->hostfwd, SLIRP_CFG_HOSTFWD);
1165     net_init_slirp_configs(user->guestfwd, 0);
1166
1167     ret = net_slirp_init(peer, "user", name, user->q_restrict,
1168                          ipv4, vnet, user->host,
1169                          ipv6, user->ipv6_prefix, user->ipv6_prefixlen,
1170                          user->ipv6_host, user->hostname, user->tftp,
1171                          user->bootfile, user->dhcpstart,
1172                          user->dns, user->ipv6_dns, user->smb,
1173                          user->smbserver, dnssearch, user->domainname,
1174                          user->tftp_server_name, errp);
1175
1176     while (slirp_configs) {
1177         config = slirp_configs;
1178         slirp_configs = config->next;
1179         g_free(config);
1180     }
1181
1182     g_free(vnet);
1183     g_free(dnssearch);
1184
1185     return ret;
1186 }