slirp/slirp.c

   1 /*
   2  * libslirp glue
   3  *
   4  * Copyright (c) 2004-2008 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 "qemu-common.h"
  25 #include "qemu-timer.h"
  26 #include "qemu-char.h"
  27 #include "slirp.h"
  28 #include "hw/hw.h"
  29
  30 /* host loopback address */
  31 struct in_addr loopback_addr;
  32 /* host loopback network mask */
  33 unsigned long loopback_mask;
  34
  35 /* emulated hosts use the MAC addr 52:55:IP:IP:IP:IP */
  36 static const uint8_t special_ethaddr[ETH_ALEN] = {
  37     0x52, 0x55, 0x00, 0x00, 0x00, 0x00
  38 };
  39
  40 static const uint8_t zero_ethaddr[ETH_ALEN] = { 0, 0, 0, 0, 0, 0 };
  41
  42 /* XXX: suppress those select globals */
  43 fd_set *global_readfds, *global_writefds, *global_xfds;
  44
  45 u_int curtime;
  46 static u_int time_fasttimo, last_slowtimo;
  47 static int do_slowtimo;
  48
  49 static QTAILQ_HEAD(slirp_instances, Slirp) slirp_instances =
  50     QTAILQ_HEAD_INITIALIZER(slirp_instances);
  51
  52 static struct in_addr dns_addr;
  53 static u_int dns_addr_time;
  54
  55 #ifdef _WIN32
  56
  57 int get_dns_addr(struct in_addr *pdns_addr)
  58 {
  59     FIXED_INFO *FixedInfo=NULL;
  60     ULONG    BufLen;
  61     DWORD    ret;
  62     IP_ADDR_STRING *pIPAddr;
  63     struct in_addr tmp_addr;
  64
  65     if (dns_addr.s_addr != 0 && (curtime - dns_addr_time) < 1000) {
  66         *pdns_addr = dns_addr;
  67         return 0;
  68     }
  69
  70     FixedInfo = (FIXED_INFO *)GlobalAlloc(GPTR, sizeof(FIXED_INFO));
  71     BufLen = sizeof(FIXED_INFO);
  72
  73     if (ERROR_BUFFER_OVERFLOW == GetNetworkParams(FixedInfo, &BufLen)) {
  74         if (FixedInfo) {
  75             GlobalFree(FixedInfo);
  76             FixedInfo = NULL;
  77         }
  78         FixedInfo = GlobalAlloc(GPTR, BufLen);
  79     }
  80
  81     if ((ret = GetNetworkParams(FixedInfo, &BufLen)) != ERROR_SUCCESS) {
  82         printf("GetNetworkParams failed. ret = %08x\n", (u_int)ret );
  83         if (FixedInfo) {
  84             GlobalFree(FixedInfo);
  85             FixedInfo = NULL;
  86         }
  87         return -1;
  88     }
  89
  90     pIPAddr = &(FixedInfo->DnsServerList);
  91     inet_aton(pIPAddr->IpAddress.String, &tmp_addr);
  92     *pdns_addr = tmp_addr;
  93     dns_addr = tmp_addr;
  94     dns_addr_time = curtime;
  95     if (FixedInfo) {
  96         GlobalFree(FixedInfo);
  97         FixedInfo = NULL;
  98     }
  99     return 0;
 100 }
 101
 102 static void winsock_cleanup(void)
 103 {
 104     WSACleanup();
 105 }
 106
 107 #else
 108
 109 static struct stat dns_addr_stat;
 110
 111 int get_dns_addr(struct in_addr *pdns_addr)
 112 {
 113     char buff[512];
 114     char buff2[257];
 115     FILE *f;
 116     int found = 0;
 117     struct in_addr tmp_addr;
 118
 119     if (dns_addr.s_addr != 0) {
 120         struct stat old_stat;
 121         if ((curtime - dns_addr_time) < 1000) {
 122             *pdns_addr = dns_addr;
 123             return 0;
 124         }
 125         old_stat = dns_addr_stat;
 126         if (stat("/etc/resolv.conf", &dns_addr_stat) != 0)
 127             return -1;
 128         if ((dns_addr_stat.st_dev == old_stat.st_dev)
 129             && (dns_addr_stat.st_ino == old_stat.st_ino)
 130             && (dns_addr_stat.st_size == old_stat.st_size)
 131             && (dns_addr_stat.st_mtime == old_stat.st_mtime)) {
 132             *pdns_addr = dns_addr;
 133             return 0;
 134         }
 135     }
 136
 137     f = fopen("/etc/resolv.conf", "r");
 138     if (!f)
 139         return -1;
 140
 141 #ifdef DEBUG
 142     lprint("IP address of your DNS(s): ");
 143 #endif
 144     while (fgets(buff, 512, f) != NULL) {
 145         if (sscanf(buff, "nameserver%*[ \t]%256s", buff2) == 1) {
 146             if (!inet_aton(buff2, &tmp_addr))
 147                 continue;
 148             /* If it's the first one, set it to dns_addr */
 149             if (!found) {
 150                 *pdns_addr = tmp_addr;
 151                 dns_addr = tmp_addr;
 152                 dns_addr_time = curtime;
 153             }
 154 #ifdef DEBUG
 155             else
 156                 lprint(", ");
 157 #endif
 158             if (++found > 3) {
 159 #ifdef DEBUG
 160                 lprint("(more)");
 161 #endif
 162                 break;
 163             }
 164 #ifdef DEBUG
 165             else
 166                 lprint("%s", inet_ntoa(tmp_addr));
 167 #endif
 168         }
 169     }
 170     fclose(f);
 171     if (!found)
 172         return -1;
 173     return 0;
 174 }
 175
 176 #endif
 177
 178 static void slirp_init_once(void)
 179 {
 180     static int initialized;
 181 #ifdef _WIN32
 182     WSADATA Data;
 183 #endif
 184
 185     if (initialized) {
 186         return;
 187     }
 188     initialized = 1;
 189
 190 #ifdef _WIN32
 191     WSAStartup(MAKEWORD(2,0), &Data);
 192     atexit(winsock_cleanup);
 193 #endif
 194
 195     loopback_addr.s_addr = htonl(INADDR_LOOPBACK);
 196     loopback_mask = htonl(IN_CLASSA_NET);
 197 }
 198
 199 static void slirp_state_save(QEMUFile *f, void *opaque);
 200 static int slirp_state_load(QEMUFile *f, void *opaque, int version_id);
 201
 202 Slirp *slirp_init(int restricted, struct in_addr vnetwork,
 203                   struct in_addr vnetmask, struct in_addr vhost,
 204                   const char *vhostname, const char *tftp_path,
 205                   const char *bootfile, struct in_addr vdhcp_start,
 206                   struct in_addr vnameserver, void *opaque)
 207 {
 208     Slirp *slirp = g_malloc0(sizeof(Slirp));
 209
 210     slirp_init_once();
 211
 212     slirp->restricted = restricted;
 213
 214     if_init(slirp);
 215     ip_init(slirp);
 216
 217     /* Initialise mbufs *after* setting the MTU */
 218     m_init(slirp);
 219
 220     slirp->vnetwork_addr = vnetwork;
 221     slirp->vnetwork_mask = vnetmask;
 222     slirp->vhost_addr = vhost;
 223     if (vhostname) {
 224         pstrcpy(slirp->client_hostname, sizeof(slirp->client_hostname),
 225                 vhostname);
 226     }
 227     if (tftp_path) {
 228         slirp->tftp_prefix = g_strdup(tftp_path);
 229     }
 230     if (bootfile) {
 231         slirp->bootp_filename = g_strdup(bootfile);
 232     }
 233     slirp->vdhcp_startaddr = vdhcp_start;
 234     slirp->vnameserver_addr = vnameserver;
 235
 236     slirp->opaque = opaque;
 237
 238     register_savevm(NULL, "slirp", 0, 3,
 239                     slirp_state_save, slirp_state_load, slirp);
 240
 241     QTAILQ_INSERT_TAIL(&slirp_instances, slirp, entry);
 242
 243     return slirp;
 244 }
 245
 246 void slirp_cleanup(Slirp *slirp)
 247 {
 248     QTAILQ_REMOVE(&slirp_instances, slirp, entry);
 249
 250     unregister_savevm(NULL, "slirp", slirp);
 251
 252     ip_cleanup(slirp);
 253     m_cleanup(slirp);
 254
 255     g_free(slirp->tftp_prefix);
 256     g_free(slirp->bootp_filename);
 257     g_free(slirp);
 258 }
 259
 260 #define CONN_CANFSEND(so) (((so)->so_state & (SS_FCANTSENDMORE|SS_ISFCONNECTED)) == SS_ISFCONNECTED)
 261 #define CONN_CANFRCV(so) (((so)->so_state & (SS_FCANTRCVMORE|SS_ISFCONNECTED)) == SS_ISFCONNECTED)
 262 #define UPD_NFDS(x) if (nfds < (x)) nfds = (x)
 263
 264 void slirp_update_timeout(uint32_t *timeout)
 265 {
 266     if (!QTAILQ_EMPTY(&slirp_instances)) {
 267         *timeout = MIN(1000, *timeout);
 268     }
 269 }
 270
 271 void slirp_select_fill(int *pnfds,
 272                        fd_set *readfds, fd_set *writefds, fd_set *xfds)
 273 {
 274     Slirp *slirp;
 275     struct socket *so, *so_next;
 276     int nfds;
 277
 278     if (QTAILQ_EMPTY(&slirp_instances)) {
 279         return;
 280     }
 281
 282     /* fail safe */
 283     global_readfds = NULL;
 284     global_writefds = NULL;
 285     global_xfds = NULL;
 286
 287     nfds = *pnfds;
 288         /*
 289          * First, TCP sockets
 290          */
 291         do_slowtimo = 0;
 292
 293         QTAILQ_FOREACH(slirp, &slirp_instances, entry) {
 294                 /*
 295                  * *_slowtimo needs calling if there are IP fragments
 296                  * in the fragment queue, or there are TCP connections active
 297                  */
 298                 do_slowtimo |= ((slirp->tcb.so_next != &slirp->tcb) ||
 299                     (&slirp->ipq.ip_link != slirp->ipq.ip_link.next));
 300
 301                 for (so = slirp->tcb.so_next; so != &slirp->tcb;
 302                      so = so_next) {
 303                         so_next = so->so_next;
 304
 305                         /*
 306                          * See if we need a tcp_fasttimo
 307                          */
 308                         if (time_fasttimo == 0 && so->so_tcpcb->t_flags & TF_DELACK)
 309                            time_fasttimo = curtime; /* Flag when we want a fasttimo */
 310
 311                         /*
 312                          * NOFDREF can include still connecting to local-host,
 313                          * newly socreated() sockets etc. Don't want to select these.
 314                          */
 315                         if (so->so_state & SS_NOFDREF || so->s == -1)
 316                            continue;
 317
 318                         /*
 319                          * Set for reading sockets which are accepting
 320                          */
 321                         if (so->so_state & SS_FACCEPTCONN) {
 322                                 FD_SET(so->s, readfds);
 323                                 UPD_NFDS(so->s);
 324                                 continue;
 325                         }
 326
 327                         /*
 328                          * Set for writing sockets which are connecting
 329                          */
 330                         if (so->so_state & SS_ISFCONNECTING) {
 331                                 FD_SET(so->s, writefds);
 332                                 UPD_NFDS(so->s);
 333                                 continue;
 334                         }
 335
 336                         /*
 337                          * Set for writing if we are connected, can send more, and
 338                          * we have something to send
 339                          */
 340                         if (CONN_CANFSEND(so) && so->so_rcv.sb_cc) {
 341                                 FD_SET(so->s, writefds);
 342                                 UPD_NFDS(so->s);
 343                         }
 344
 345                         /*
 346                          * Set for reading (and urgent data) if we are connected, can
 347                          * receive more, and we have room for it XXX /2 ?
 348                          */
 349                         if (CONN_CANFRCV(so) && (so->so_snd.sb_cc < (so->so_snd.sb_datalen/2))) {
 350                                 FD_SET(so->s, readfds);
 351                                 FD_SET(so->s, xfds);
 352                                 UPD_NFDS(so->s);
 353                         }
 354                 }
 355
 356                 /*
 357                  * UDP sockets
 358                  */
 359                 for (so = slirp->udb.so_next; so != &slirp->udb;
 360                      so = so_next) {
 361                         so_next = so->so_next;
 362
 363                         /*
 364                          * See if it's timed out
 365                          */
 366                         if (so->so_expire) {
 367                                 if (so->so_expire <= curtime) {
 368                                         udp_detach(so);
 369                                         continue;
 370                                 } else
 371                                         do_slowtimo = 1; /* Let socket expire */
 372                         }
 373
 374                         /*
 375                          * When UDP packets are received from over the
 376                          * link, they're sendto()'d straight away, so
 377                          * no need for setting for writing
 378                          * Limit the number of packets queued by this session
 379                          * to 4.  Note that even though we try and limit this
 380                          * to 4 packets, the session could have more queued
 381                          * if the packets needed to be fragmented
 382                          * (XXX <= 4 ?)
 383                          */
 384                         if ((so->so_state & SS_ISFCONNECTED) && so->so_queued <= 4) {
 385                                 FD_SET(so->s, readfds);
 386                                 UPD_NFDS(so->s);
 387                         }
 388                 }
 389
 390                 /*
 391                  * ICMP sockets
 392                  */
 393                 for (so = slirp->icmp.so_next; so != &slirp->icmp;
 394                      so = so_next) {
 395                     so_next = so->so_next;
 396
 397                     /*
 398                      * See if it's timed out
 399                      */
 400                     if (so->so_expire) {
 401                         if (so->so_expire <= curtime) {
 402                             icmp_detach(so);
 403                             continue;
 404                         } else {
 405                             do_slowtimo = 1; /* Let socket expire */
 406                         }
 407                     }
 408
 409                     if (so->so_state & SS_ISFCONNECTED) {
 410                         FD_SET(so->s, readfds);
 411                         UPD_NFDS(so->s);
 412                     }
 413                 }
 414         }
 415
 416         *pnfds = nfds;
 417 }
 418
 419 void slirp_select_poll(fd_set *readfds, fd_set *writefds, fd_set *xfds,
 420                        int select_error)
 421 {
 422     Slirp *slirp;
 423     struct socket *so, *so_next;
 424     int ret;
 425
 426     if (QTAILQ_EMPTY(&slirp_instances)) {
 427         return;
 428     }
 429
 430     global_readfds = readfds;
 431     global_writefds = writefds;
 432     global_xfds = xfds;
 433
 434     curtime = qemu_get_clock_ms(rt_clock);
 435
 436     QTAILQ_FOREACH(slirp, &slirp_instances, entry) {
 437         /*
 438          * See if anything has timed out
 439          */
 440                 if (time_fasttimo && ((curtime - time_fasttimo) >= 2)) {
 441                         tcp_fasttimo(slirp);
 442                         time_fasttimo = 0;
 443                 }
 444                 if (do_slowtimo && ((curtime - last_slowtimo) >= 499)) {
 445                         ip_slowtimo(slirp);
 446                         tcp_slowtimo(slirp);
 447                         last_slowtimo = curtime;
 448                 }
 449
 450         /*
 451          * Check sockets
 452          */
 453         if (!select_error) {
 454                 /*
 455                  * Check TCP sockets
 456                  */
 457                 for (so = slirp->tcb.so_next; so != &slirp->tcb;
 458                      so = so_next) {
 459                         so_next = so->so_next;
 460
 461                         /*
 462                          * FD_ISSET is meaningless on these sockets
 463                          * (and they can crash the program)
 464                          */
 465                         if (so->so_state & SS_NOFDREF || so->s == -1)
 466                            continue;
 467
 468                         /*
 469                          * Check for URG data
 470                          * This will soread as well, so no need to
 471                          * test for readfds below if this succeeds
 472                          */
 473                         if (FD_ISSET(so->s, xfds))
 474                            sorecvoob(so);
 475                         /*
 476                          * Check sockets for reading
 477                          */
 478                         else if (FD_ISSET(so->s, readfds)) {
 479                                 /*
 480                                  * Check for incoming connections
 481                                  */
 482                                 if (so->so_state & SS_FACCEPTCONN) {
 483                                         tcp_connect(so);
 484                                         continue;
 485                                 } /* else */
 486                                 ret = soread(so);
 487
 488                                 /* Output it if we read something */
 489                                 if (ret > 0)
 490                                    tcp_output(sototcpcb(so));
 491                         }
 492
 493                         /*
 494                          * Check sockets for writing
 495                          */
 496                         if (FD_ISSET(so->s, writefds)) {
 497                           /*
 498                            * Check for non-blocking, still-connecting sockets
 499                            */
 500                           if (so->so_state & SS_ISFCONNECTING) {
 501                             /* Connected */
 502                             so->so_state &= ~SS_ISFCONNECTING;
 503
 504                             ret = send(so->s, (const void *) &ret, 0, 0);
 505                             if (ret < 0) {
 506                               /* XXXXX Must fix, zero bytes is a NOP */
 507                               if (errno == EAGAIN || errno == EWOULDBLOCK ||
 508                                   errno == EINPROGRESS || errno == ENOTCONN)
 509                                 continue;
 510
 511                               /* else failed */
 512                               so->so_state &= SS_PERSISTENT_MASK;
 513                               so->so_state |= SS_NOFDREF;
 514                             }
 515                             /* else so->so_state &= ~SS_ISFCONNECTING; */
 516
 517                             /*
 518                              * Continue tcp_input
 519                              */
 520                             tcp_input((struct mbuf *)NULL, sizeof(struct ip), so);
 521                             /* continue; */
 522                           } else
 523                             ret = sowrite(so);
 524                           /*
 525                            * XXXXX If we wrote something (a lot), there
 526                            * could be a need for a window update.
 527                            * In the worst case, the remote will send
 528                            * a window probe to get things going again
 529                            */
 530                         }
 531
 532                         /*
 533                          * Probe a still-connecting, non-blocking socket
 534                          * to check if it's still alive
 535                          */
 536 #ifdef PROBE_CONN
 537                         if (so->so_state & SS_ISFCONNECTING) {
 538                           ret = qemu_recv(so->s, &ret, 0,0);
 539
 540                           if (ret < 0) {
 541                             /* XXX */
 542                             if (errno == EAGAIN || errno == EWOULDBLOCK ||
 543                                 errno == EINPROGRESS || errno == ENOTCONN)
 544                               continue; /* Still connecting, continue */
 545
 546                             /* else failed */
 547                             so->so_state &= SS_PERSISTENT_MASK;
 548                             so->so_state |= SS_NOFDREF;
 549
 550                             /* tcp_input will take care of it */
 551                           } else {
 552                             ret = send(so->s, &ret, 0,0);
 553                             if (ret < 0) {
 554                               /* XXX */
 555                               if (errno == EAGAIN || errno == EWOULDBLOCK ||
 556                                   errno == EINPROGRESS || errno == ENOTCONN)
 557                                 continue;
 558                               /* else failed */
 559                               so->so_state &= SS_PERSISTENT_MASK;
 560                               so->so_state |= SS_NOFDREF;
 561                             } else
 562                               so->so_state &= ~SS_ISFCONNECTING;
 563
 564                           }
 565                           tcp_input((struct mbuf *)NULL, sizeof(struct ip),so);
 566                         } /* SS_ISFCONNECTING */
 567 #endif
 568                 }
 569
 570                 /*
 571                  * Now UDP sockets.
 572                  * Incoming packets are sent straight away, they're not buffered.
 573                  * Incoming UDP data isn't buffered either.
 574                  */
 575                 for (so = slirp->udb.so_next; so != &slirp->udb;
 576                      so = so_next) {
 577                         so_next = so->so_next;
 578
 579                         if (so->s != -1 && FD_ISSET(so->s, readfds)) {
 580                             sorecvfrom(so);
 581                         }
 582                 }
 583
 584                 /*
 585                  * Check incoming ICMP relies.
 586                  */
 587                 for (so = slirp->icmp.so_next; so != &slirp->icmp;
 588                      so = so_next) {
 589                      so_next = so->so_next;
 590
 591                     if (so->s != -1 && FD_ISSET(so->s, readfds)) {
 592                         icmp_receive(so);
 593                     }
 594                 }
 595         }
 596
 597         if_start(slirp);
 598     }
 599
 600         /* clear global file descriptor sets.
 601          * these reside on the stack in vl.c
 602          * so they're unusable if we're not in
 603          * slirp_select_fill or slirp_select_poll.
 604          */
 605          global_readfds = NULL;
 606          global_writefds = NULL;
 607          global_xfds = NULL;
 608 }
 609
 610 static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
 611 {
 612     struct arphdr *ah = (struct arphdr *)(pkt + ETH_HLEN);
 613     uint8_t arp_reply[max(ETH_HLEN + sizeof(struct arphdr), 64)];
 614     struct ethhdr *reh = (struct ethhdr *)arp_reply;
 615     struct arphdr *rah = (struct arphdr *)(arp_reply + ETH_HLEN);
 616     int ar_op;
 617     struct ex_list *ex_ptr;
 618
 619     ar_op = ntohs(ah->ar_op);
 620     switch(ar_op) {
 621     case ARPOP_REQUEST:
 622         if (ah->ar_tip == ah->ar_sip) {
 623             /* Gratuitous ARP */
 624             arp_table_add(slirp, ah->ar_sip, ah->ar_sha);
 625             return;
 626         }
 627
 628         if ((ah->ar_tip & slirp->vnetwork_mask.s_addr) ==
 629             slirp->vnetwork_addr.s_addr) {
 630             if (ah->ar_tip == slirp->vnameserver_addr.s_addr ||
 631                 ah->ar_tip == slirp->vhost_addr.s_addr)
 632                 goto arp_ok;
 633             for (ex_ptr = slirp->exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next) {
 634                 if (ex_ptr->ex_addr.s_addr == ah->ar_tip)
 635                     goto arp_ok;
 636             }
 637             return;
 638         arp_ok:
 639             memset(arp_reply, 0, sizeof(arp_reply));
 640
 641             arp_table_add(slirp, ah->ar_sip, ah->ar_sha);
 642
 643             /* ARP request for alias/dns mac address */
 644             memcpy(reh->h_dest, pkt + ETH_ALEN, ETH_ALEN);
 645             memcpy(reh->h_source, special_ethaddr, ETH_ALEN - 4);
 646             memcpy(&reh->h_source[2], &ah->ar_tip, 4);
 647             reh->h_proto = htons(ETH_P_ARP);
 648
 649             rah->ar_hrd = htons(1);
 650             rah->ar_pro = htons(ETH_P_IP);
 651             rah->ar_hln = ETH_ALEN;
 652             rah->ar_pln = 4;
 653             rah->ar_op = htons(ARPOP_REPLY);
 654             memcpy(rah->ar_sha, reh->h_source, ETH_ALEN);
 655             rah->ar_sip = ah->ar_tip;
 656             memcpy(rah->ar_tha, ah->ar_sha, ETH_ALEN);
 657             rah->ar_tip = ah->ar_sip;
 658             slirp_output(slirp->opaque, arp_reply, sizeof(arp_reply));
 659         }
 660         break;
 661     case ARPOP_REPLY:
 662         arp_table_add(slirp, ah->ar_sip, ah->ar_sha);
 663         break;
 664     default:
 665         break;
 666     }
 667 }
 668
 669 void slirp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
 670 {
 671     struct mbuf *m;
 672     int proto;
 673
 674     if (pkt_len < ETH_HLEN)
 675         return;
 676
 677     proto = ntohs(*(uint16_t *)(pkt + 12));
 678     switch(proto) {
 679     case ETH_P_ARP:
 680         arp_input(slirp, pkt, pkt_len);
 681         break;
 682     case ETH_P_IP:
 683         m = m_get(slirp);
 684         if (!m)
 685             return;
 686         /* Note: we add to align the IP header */
 687         if (M_FREEROOM(m) < pkt_len + 2) {
 688             m_inc(m, pkt_len + 2);
 689         }
 690         m->m_len = pkt_len + 2;
 691         memcpy(m->m_data + 2, pkt, pkt_len);
 692
 693         m->m_data += 2 + ETH_HLEN;
 694         m->m_len -= 2 + ETH_HLEN;
 695
 696         ip_input(m);
 697         break;
 698     default:
 699         break;
 700     }
 701 }
 702
 703 /* Output the IP packet to the ethernet device. Returns 0 if the packet must be
 704  * re-queued.
 705  */
 706 int if_encap(Slirp *slirp, struct mbuf *ifm)
 707 {
 708     uint8_t buf[1600];
 709     struct ethhdr *eh = (struct ethhdr *)buf;
 710     uint8_t ethaddr[ETH_ALEN];
 711     const struct ip *iph = (const struct ip *)ifm->m_data;
 712
 713     if (ifm->m_len + ETH_HLEN > sizeof(buf)) {
 714         return 1;
 715     }
 716
 717     if (!arp_table_search(slirp, iph->ip_dst.s_addr, ethaddr)) {
 718         uint8_t arp_req[ETH_HLEN + sizeof(struct arphdr)];
 719         struct ethhdr *reh = (struct ethhdr *)arp_req;
 720         struct arphdr *rah = (struct arphdr *)(arp_req + ETH_HLEN);
 721
 722         if (!ifm->arp_requested) {
 723             /* If the client addr is not known, send an ARP request */
 724             memset(reh->h_dest, 0xff, ETH_ALEN);
 725             memcpy(reh->h_source, special_ethaddr, ETH_ALEN - 4);
 726             memcpy(&reh->h_source[2], &slirp->vhost_addr, 4);
 727             reh->h_proto = htons(ETH_P_ARP);
 728             rah->ar_hrd = htons(1);
 729             rah->ar_pro = htons(ETH_P_IP);
 730             rah->ar_hln = ETH_ALEN;
 731             rah->ar_pln = 4;
 732             rah->ar_op = htons(ARPOP_REQUEST);
 733
 734             /* source hw addr */
 735             memcpy(rah->ar_sha, special_ethaddr, ETH_ALEN - 4);
 736             memcpy(&rah->ar_sha[2], &slirp->vhost_addr, 4);
 737
 738             /* source IP */
 739             rah->ar_sip = slirp->vhost_addr.s_addr;
 740
 741             /* target hw addr (none) */
 742             memset(rah->ar_tha, 0, ETH_ALEN);
 743
 744             /* target IP */
 745             rah->ar_tip = iph->ip_dst.s_addr;
 746             slirp->client_ipaddr = iph->ip_dst;
 747             slirp_output(slirp->opaque, arp_req, sizeof(arp_req));
 748             ifm->arp_requested = true;
 749
 750             /* Expire request and drop outgoing packet after 1 second */
 751             ifm->expiration_date = qemu_get_clock_ns(rt_clock) + 1000000000ULL;
 752         }
 753         return 0;
 754     } else {
 755         memcpy(eh->h_dest, ethaddr, ETH_ALEN);
 756         memcpy(eh->h_source, special_ethaddr, ETH_ALEN - 4);
 757         /* XXX: not correct */
 758         memcpy(&eh->h_source[2], &slirp->vhost_addr, 4);
 759         eh->h_proto = htons(ETH_P_IP);
 760         memcpy(buf + sizeof(struct ethhdr), ifm->m_data, ifm->m_len);
 761         slirp_output(slirp->opaque, buf, ifm->m_len + ETH_HLEN);
 762         return 1;
 763     }
 764 }
 765
 766 /* Drop host forwarding rule, return 0 if found. */
 767 int slirp_remove_hostfwd(Slirp *slirp, int is_udp, struct in_addr host_addr,
 768                          int host_port)
 769 {
 770     struct socket *so;
 771     struct socket *head = (is_udp ? &slirp->udb : &slirp->tcb);
 772     struct sockaddr_in addr;
 773     int port = htons(host_port);
 774     socklen_t addr_len;
 775
 776     for (so = head->so_next; so != head; so = so->so_next) {
 777         addr_len = sizeof(addr);
 778         if ((so->so_state & SS_HOSTFWD) &&
 779             getsockname(so->s, (struct sockaddr *)&addr, &addr_len) == 0 &&
 780             addr.sin_addr.s_addr == host_addr.s_addr &&
 781             addr.sin_port == port) {
 782             close(so->s);
 783             sofree(so);
 784             return 0;
 785         }
 786     }
 787
 788     return -1;
 789 }
 790
 791 int slirp_add_hostfwd(Slirp *slirp, int is_udp, struct in_addr host_addr,
 792                       int host_port, struct in_addr guest_addr, int guest_port)
 793 {
 794     if (!guest_addr.s_addr) {
 795         guest_addr = slirp->vdhcp_startaddr;
 796     }
 797     if (is_udp) {
 798         if (!udp_listen(slirp, host_addr.s_addr, htons(host_port),
 799                         guest_addr.s_addr, htons(guest_port), SS_HOSTFWD))
 800             return -1;
 801     } else {
 802         if (!tcp_listen(slirp, host_addr.s_addr, htons(host_port),
 803                         guest_addr.s_addr, htons(guest_port), SS_HOSTFWD))
 804             return -1;
 805     }
 806     return 0;
 807 }
 808
 809 int slirp_add_exec(Slirp *slirp, int do_pty, const void *args,
 810                    struct in_addr *guest_addr, int guest_port)
 811 {
 812     if (!guest_addr->s_addr) {
 813         guest_addr->s_addr = slirp->vnetwork_addr.s_addr |
 814             (htonl(0x0204) & ~slirp->vnetwork_mask.s_addr);
 815     }
 816     if ((guest_addr->s_addr & slirp->vnetwork_mask.s_addr) !=
 817         slirp->vnetwork_addr.s_addr ||
 818         guest_addr->s_addr == slirp->vhost_addr.s_addr ||
 819         guest_addr->s_addr == slirp->vnameserver_addr.s_addr) {
 820         return -1;
 821     }
 822     return add_exec(&slirp->exec_list, do_pty, (char *)args, *guest_addr,
 823                     htons(guest_port));
 824 }
 825
 826 ssize_t slirp_send(struct socket *so, const void *buf, size_t len, int flags)
 827 {
 828         if (so->s == -1 && so->extra) {
 829                 qemu_chr_fe_write(so->extra, buf, len);
 830                 return len;
 831         }
 832
 833         return send(so->s, buf, len, flags);
 834 }
 835
 836 static struct socket *
 837 slirp_find_ctl_socket(Slirp *slirp, struct in_addr guest_addr, int guest_port)
 838 {
 839     struct socket *so;
 840
 841     for (so = slirp->tcb.so_next; so != &slirp->tcb; so = so->so_next) {
 842         if (so->so_faddr.s_addr == guest_addr.s_addr &&
 843             htons(so->so_fport) == guest_port) {
 844             return so;
 845         }
 846     }
 847     return NULL;
 848 }
 849
 850 size_t slirp_socket_can_recv(Slirp *slirp, struct in_addr guest_addr,
 851                              int guest_port)
 852 {
 853         struct iovec iov[2];
 854         struct socket *so;
 855
 856         so = slirp_find_ctl_socket(slirp, guest_addr, guest_port);
 857
 858         if (!so || so->so_state & SS_NOFDREF)
 859                 return 0;
 860
 861         if (!CONN_CANFRCV(so) || so->so_snd.sb_cc >= (so->so_snd.sb_datalen/2))
 862                 return 0;
 863
 864         return sopreprbuf(so, iov, NULL);
 865 }
 866
 867 void slirp_socket_recv(Slirp *slirp, struct in_addr guest_addr, int guest_port,
 868                        const uint8_t *buf, int size)
 869 {
 870     int ret;
 871     struct socket *so = slirp_find_ctl_socket(slirp, guest_addr, guest_port);
 872
 873     if (!so)
 874         return;
 875
 876     ret = soreadbuf(so, (const char *)buf, size);
 877
 878     if (ret > 0)
 879         tcp_output(sototcpcb(so));
 880 }
 881
 882 static void slirp_tcp_save(QEMUFile *f, struct tcpcb *tp)
 883 {
 884     int i;
 885
 886     qemu_put_sbe16(f, tp->t_state);
 887     for (i = 0; i < TCPT_NTIMERS; i++)
 888         qemu_put_sbe16(f, tp->t_timer[i]);
 889     qemu_put_sbe16(f, tp->t_rxtshift);
 890     qemu_put_sbe16(f, tp->t_rxtcur);
 891     qemu_put_sbe16(f, tp->t_dupacks);
 892     qemu_put_be16(f, tp->t_maxseg);
 893     qemu_put_sbyte(f, tp->t_force);
 894     qemu_put_be16(f, tp->t_flags);
 895     qemu_put_be32(f, tp->snd_una);
 896     qemu_put_be32(f, tp->snd_nxt);
 897     qemu_put_be32(f, tp->snd_up);
 898     qemu_put_be32(f, tp->snd_wl1);
 899     qemu_put_be32(f, tp->snd_wl2);
 900     qemu_put_be32(f, tp->iss);
 901     qemu_put_be32(f, tp->snd_wnd);
 902     qemu_put_be32(f, tp->rcv_wnd);
 903     qemu_put_be32(f, tp->rcv_nxt);
 904     qemu_put_be32(f, tp->rcv_up);
 905     qemu_put_be32(f, tp->irs);
 906     qemu_put_be32(f, tp->rcv_adv);
 907     qemu_put_be32(f, tp->snd_max);
 908     qemu_put_be32(f, tp->snd_cwnd);
 909     qemu_put_be32(f, tp->snd_ssthresh);
 910     qemu_put_sbe16(f, tp->t_idle);
 911     qemu_put_sbe16(f, tp->t_rtt);
 912     qemu_put_be32(f, tp->t_rtseq);
 913     qemu_put_sbe16(f, tp->t_srtt);
 914     qemu_put_sbe16(f, tp->t_rttvar);
 915     qemu_put_be16(f, tp->t_rttmin);
 916     qemu_put_be32(f, tp->max_sndwnd);
 917     qemu_put_byte(f, tp->t_oobflags);
 918     qemu_put_byte(f, tp->t_iobc);
 919     qemu_put_sbe16(f, tp->t_softerror);
 920     qemu_put_byte(f, tp->snd_scale);
 921     qemu_put_byte(f, tp->rcv_scale);
 922     qemu_put_byte(f, tp->request_r_scale);
 923     qemu_put_byte(f, tp->requested_s_scale);
 924     qemu_put_be32(f, tp->ts_recent);
 925     qemu_put_be32(f, tp->ts_recent_age);
 926     qemu_put_be32(f, tp->last_ack_sent);
 927 }
 928
 929 static void slirp_sbuf_save(QEMUFile *f, struct sbuf *sbuf)
 930 {
 931     uint32_t off;
 932
 933     qemu_put_be32(f, sbuf->sb_cc);
 934     qemu_put_be32(f, sbuf->sb_datalen);
 935     off = (uint32_t)(sbuf->sb_wptr - sbuf->sb_data);
 936     qemu_put_sbe32(f, off);
 937     off = (uint32_t)(sbuf->sb_rptr - sbuf->sb_data);
 938     qemu_put_sbe32(f, off);
 939     qemu_put_buffer(f, (unsigned char*)sbuf->sb_data, sbuf->sb_datalen);
 940 }
 941
 942 static void slirp_socket_save(QEMUFile *f, struct socket *so)
 943 {
 944     qemu_put_be32(f, so->so_urgc);
 945     qemu_put_be32(f, so->so_faddr.s_addr);
 946     qemu_put_be32(f, so->so_laddr.s_addr);
 947     qemu_put_be16(f, so->so_fport);
 948     qemu_put_be16(f, so->so_lport);
 949     qemu_put_byte(f, so->so_iptos);
 950     qemu_put_byte(f, so->so_emu);
 951     qemu_put_byte(f, so->so_type);
 952     qemu_put_be32(f, so->so_state);
 953     slirp_sbuf_save(f, &so->so_rcv);
 954     slirp_sbuf_save(f, &so->so_snd);
 955     slirp_tcp_save(f, so->so_tcpcb);
 956 }
 957
 958 static void slirp_bootp_save(QEMUFile *f, Slirp *slirp)
 959 {
 960     int i;
 961
 962     for (i = 0; i < NB_BOOTP_CLIENTS; i++) {
 963         qemu_put_be16(f, slirp->bootp_clients[i].allocated);
 964         qemu_put_buffer(f, slirp->bootp_clients[i].macaddr, 6);
 965     }
 966 }
 967
 968 static void slirp_state_save(QEMUFile *f, void *opaque)
 969 {
 970     Slirp *slirp = opaque;
 971     struct ex_list *ex_ptr;
 972
 973     for (ex_ptr = slirp->exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next)
 974         if (ex_ptr->ex_pty == 3) {
 975             struct socket *so;
 976             so = slirp_find_ctl_socket(slirp, ex_ptr->ex_addr,
 977                                        ntohs(ex_ptr->ex_fport));
 978             if (!so)
 979                 continue;
 980
 981             qemu_put_byte(f, 42);
 982             slirp_socket_save(f, so);
 983         }
 984     qemu_put_byte(f, 0);
 985
 986     qemu_put_be16(f, slirp->ip_id);
 987
 988     slirp_bootp_save(f, slirp);
 989 }
 990
 991 static void slirp_tcp_load(QEMUFile *f, struct tcpcb *tp)
 992 {
 993     int i;
 994
 995     tp->t_state = qemu_get_sbe16(f);
 996     for (i = 0; i < TCPT_NTIMERS; i++)
 997         tp->t_timer[i] = qemu_get_sbe16(f);
 998     tp->t_rxtshift = qemu_get_sbe16(f);
 999     tp->t_rxtcur = qemu_get_sbe16(f);
1000     tp->t_dupacks = qemu_get_sbe16(f);
1001     tp->t_maxseg = qemu_get_be16(f);
1002     tp->t_force = qemu_get_sbyte(f);
1003     tp->t_flags = qemu_get_be16(f);
1004     tp->snd_una = qemu_get_be32(f);
1005     tp->snd_nxt = qemu_get_be32(f);
1006     tp->snd_up = qemu_get_be32(f);
1007     tp->snd_wl1 = qemu_get_be32(f);
1008     tp->snd_wl2 = qemu_get_be32(f);
1009     tp->iss = qemu_get_be32(f);
1010     tp->snd_wnd = qemu_get_be32(f);
1011     tp->rcv_wnd = qemu_get_be32(f);
1012     tp->rcv_nxt = qemu_get_be32(f);
1013     tp->rcv_up = qemu_get_be32(f);
1014     tp->irs = qemu_get_be32(f);
1015     tp->rcv_adv = qemu_get_be32(f);
1016     tp->snd_max = qemu_get_be32(f);
1017     tp->snd_cwnd = qemu_get_be32(f);
1018     tp->snd_ssthresh = qemu_get_be32(f);
1019     tp->t_idle = qemu_get_sbe16(f);
1020     tp->t_rtt = qemu_get_sbe16(f);
1021     tp->t_rtseq = qemu_get_be32(f);
1022     tp->t_srtt = qemu_get_sbe16(f);
1023     tp->t_rttvar = qemu_get_sbe16(f);
1024     tp->t_rttmin = qemu_get_be16(f);
1025     tp->max_sndwnd = qemu_get_be32(f);
1026     tp->t_oobflags = qemu_get_byte(f);
1027     tp->t_iobc = qemu_get_byte(f);
1028     tp->t_softerror = qemu_get_sbe16(f);
1029     tp->snd_scale = qemu_get_byte(f);
1030     tp->rcv_scale = qemu_get_byte(f);
1031     tp->request_r_scale = qemu_get_byte(f);
1032     tp->requested_s_scale = qemu_get_byte(f);
1033     tp->ts_recent = qemu_get_be32(f);
1034     tp->ts_recent_age = qemu_get_be32(f);
1035     tp->last_ack_sent = qemu_get_be32(f);
1036     tcp_template(tp);
1037 }
1038
1039 static int slirp_sbuf_load(QEMUFile *f, struct sbuf *sbuf)
1040 {
1041     uint32_t off, sb_cc, sb_datalen;
1042
1043     sb_cc = qemu_get_be32(f);
1044     sb_datalen = qemu_get_be32(f);
1045
1046     sbreserve(sbuf, sb_datalen);
1047
1048     if (sbuf->sb_datalen != sb_datalen)
1049         return -ENOMEM;
1050
1051     sbuf->sb_cc = sb_cc;
1052
1053     off = qemu_get_sbe32(f);
1054     sbuf->sb_wptr = sbuf->sb_data + off;
1055     off = qemu_get_sbe32(f);
1056     sbuf->sb_rptr = sbuf->sb_data + off;
1057     qemu_get_buffer(f, (unsigned char*)sbuf->sb_data, sbuf->sb_datalen);
1058
1059     return 0;
1060 }
1061
1062 static int slirp_socket_load(QEMUFile *f, struct socket *so)
1063 {
1064     if (tcp_attach(so) < 0)
1065         return -ENOMEM;
1066
1067     so->so_urgc = qemu_get_be32(f);
1068     so->so_faddr.s_addr = qemu_get_be32(f);
1069     so->so_laddr.s_addr = qemu_get_be32(f);
1070     so->so_fport = qemu_get_be16(f);
1071     so->so_lport = qemu_get_be16(f);
1072     so->so_iptos = qemu_get_byte(f);
1073     so->so_emu = qemu_get_byte(f);
1074     so->so_type = qemu_get_byte(f);
1075     so->so_state = qemu_get_be32(f);
1076     if (slirp_sbuf_load(f, &so->so_rcv) < 0)
1077         return -ENOMEM;
1078     if (slirp_sbuf_load(f, &so->so_snd) < 0)
1079         return -ENOMEM;
1080     slirp_tcp_load(f, so->so_tcpcb);
1081
1082     return 0;
1083 }
1084
1085 static void slirp_bootp_load(QEMUFile *f, Slirp *slirp)
1086 {
1087     int i;
1088
1089     for (i = 0; i < NB_BOOTP_CLIENTS; i++) {
1090         slirp->bootp_clients[i].allocated = qemu_get_be16(f);
1091         qemu_get_buffer(f, slirp->bootp_clients[i].macaddr, 6);
1092     }
1093 }
1094
1095 static int slirp_state_load(QEMUFile *f, void *opaque, int version_id)
1096 {
1097     Slirp *slirp = opaque;
1098     struct ex_list *ex_ptr;
1099
1100     while (qemu_get_byte(f)) {
1101         int ret;
1102         struct socket *so = socreate(slirp);
1103
1104         if (!so)
1105             return -ENOMEM;
1106
1107         ret = slirp_socket_load(f, so);
1108
1109         if (ret < 0)
1110             return ret;
1111
1112         if ((so->so_faddr.s_addr & slirp->vnetwork_mask.s_addr) !=
1113             slirp->vnetwork_addr.s_addr) {
1114             return -EINVAL;
1115         }
1116         for (ex_ptr = slirp->exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next) {
1117             if (ex_ptr->ex_pty == 3 &&
1118                 so->so_faddr.s_addr == ex_ptr->ex_addr.s_addr &&
1119                 so->so_fport == ex_ptr->ex_fport) {
1120                 break;
1121             }
1122         }
1123         if (!ex_ptr)
1124             return -EINVAL;
1125
1126         so->extra = (void *)ex_ptr->ex_exec;
1127     }
1128
1129     if (version_id >= 2) {
1130         slirp->ip_id = qemu_get_be16(f);
1131     }
1132
1133     if (version_id >= 3) {
1134         slirp_bootp_load(f, slirp);
1135     }
1136
1137     return 0;
1138 }