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-char.h"
  26 #include "slirp.h"
  27 #include "hw/hw.h"
  28
  29 /* host address */
  30 struct in_addr our_addr;
  31 /* host dns address */
  32 struct in_addr dns_addr;
  33 /* host loopback address */
  34 struct in_addr loopback_addr;
  35
  36 /* address for slirp virtual addresses */
  37 struct in_addr special_addr;
  38 /* virtual address alias for host */
  39 struct in_addr alias_addr;
  40
  41 static const uint8_t special_ethaddr[6] = {
  42     0x52, 0x54, 0x00, 0x12, 0x35, 0x00
  43 };
  44
  45 /* ARP cache for the guest IP addresses (XXX: allow many entries) */
  46 uint8_t client_ethaddr[6];
  47 static struct in_addr client_ipaddr;
  48
  49 static const uint8_t zero_ethaddr[6] = { 0, 0, 0, 0, 0, 0 };
  50
  51 const char *slirp_special_ip = CTL_SPECIAL;
  52 int slirp_restrict;
  53 static int do_slowtimo;
  54 int link_up;
  55 struct timeval tt;
  56 FILE *lfd;
  57 struct ex_list *exec_list;
  58
  59 /* XXX: suppress those select globals */
  60 fd_set *global_readfds, *global_writefds, *global_xfds;
  61
  62 char slirp_hostname[33];
  63
  64 #ifdef _WIN32
  65
  66 static int get_dns_addr(struct in_addr *pdns_addr)
  67 {
  68     FIXED_INFO *FixedInfo=NULL;
  69     ULONG    BufLen;
  70     DWORD    ret;
  71     IP_ADDR_STRING *pIPAddr;
  72     struct in_addr tmp_addr;
  73
  74     FixedInfo = (FIXED_INFO *)GlobalAlloc(GPTR, sizeof(FIXED_INFO));
  75     BufLen = sizeof(FIXED_INFO);
  76
  77     if (ERROR_BUFFER_OVERFLOW == GetNetworkParams(FixedInfo, &BufLen)) {
  78         if (FixedInfo) {
  79             GlobalFree(FixedInfo);
  80             FixedInfo = NULL;
  81         }
  82         FixedInfo = GlobalAlloc(GPTR, BufLen);
  83     }
  84
  85     if ((ret = GetNetworkParams(FixedInfo, &BufLen)) != ERROR_SUCCESS) {
  86         printf("GetNetworkParams failed. ret = %08x\n", (u_int)ret );
  87         if (FixedInfo) {
  88             GlobalFree(FixedInfo);
  89             FixedInfo = NULL;
  90         }
  91         return -1;
  92     }
  93
  94     pIPAddr = &(FixedInfo->DnsServerList);
  95     inet_aton(pIPAddr->IpAddress.String, &tmp_addr);
  96     *pdns_addr = tmp_addr;
  97 #if 0
  98     printf( "DNS Servers:\n" );
  99     printf( "DNS Addr:%s\n", pIPAddr->IpAddress.String );
 100
 101     pIPAddr = FixedInfo -> DnsServerList.Next;
 102     while ( pIPAddr ) {
 103             printf( "DNS Addr:%s\n", pIPAddr ->IpAddress.String );
 104             pIPAddr = pIPAddr ->Next;
 105     }
 106 #endif
 107     if (FixedInfo) {
 108         GlobalFree(FixedInfo);
 109         FixedInfo = NULL;
 110     }
 111     return 0;
 112 }
 113
 114 #else
 115
 116 static int get_dns_addr(struct in_addr *pdns_addr)
 117 {
 118     char buff[512];
 119     char buff2[257];
 120     FILE *f;
 121     int found = 0;
 122     struct in_addr tmp_addr;
 123
 124     f = fopen("/etc/resolv.conf", "r");
 125     if (!f)
 126         return -1;
 127
 128 #ifdef DEBUG
 129     lprint("IP address of your DNS(s): ");
 130 #endif
 131     while (fgets(buff, 512, f) != NULL) {
 132         if (sscanf(buff, "nameserver%*[ \t]%256s", buff2) == 1) {
 133             if (!inet_aton(buff2, &tmp_addr))
 134                 continue;
 135             if (tmp_addr.s_addr == loopback_addr.s_addr)
 136                 tmp_addr = our_addr;
 137             /* If it's the first one, set it to dns_addr */
 138             if (!found)
 139                 *pdns_addr = tmp_addr;
 140 #ifdef DEBUG
 141             else
 142                 lprint(", ");
 143 #endif
 144             if (++found > 3) {
 145 #ifdef DEBUG
 146                 lprint("(more)");
 147 #endif
 148                 break;
 149             }
 150 #ifdef DEBUG
 151             else
 152                 lprint("%s", inet_ntoa(tmp_addr));
 153 #endif
 154         }
 155     }
 156     fclose(f);
 157     if (!found)
 158         return -1;
 159     return 0;
 160 }
 161
 162 #endif
 163
 164 #ifdef _WIN32
 165 static void slirp_cleanup(void)
 166 {
 167     WSACleanup();
 168 }
 169 #endif
 170
 171 static void slirp_state_save(QEMUFile *f, void *opaque);
 172 static int slirp_state_load(QEMUFile *f, void *opaque, int version_id);
 173
 174 void slirp_init(int restricted, char *special_ip)
 175 {
 176     //    debug_init("/tmp/slirp.log", DEBUG_DEFAULT);
 177
 178 #ifdef _WIN32
 179     {
 180         WSADATA Data;
 181         WSAStartup(MAKEWORD(2,0), &Data);
 182         atexit(slirp_cleanup);
 183     }
 184 #endif
 185
 186     link_up = 1;
 187     slirp_restrict = restricted;
 188
 189     if_init();
 190     ip_init();
 191
 192     /* Initialise mbufs *after* setting the MTU */
 193     m_init();
 194
 195     /* set default addresses */
 196     inet_aton("127.0.0.1", &loopback_addr);
 197
 198     if (get_dns_addr(&dns_addr) < 0) {
 199         dns_addr = loopback_addr;
 200         fprintf (stderr, "Warning: No DNS servers found\n");
 201     }
 202
 203     if (special_ip)
 204         slirp_special_ip = special_ip;
 205
 206     inet_aton(slirp_special_ip, &special_addr);
 207     alias_addr.s_addr = special_addr.s_addr | htonl(CTL_ALIAS);
 208     getouraddr();
 209     register_savevm("slirp", 0, 1, slirp_state_save, slirp_state_load, NULL);
 210 }
 211
 212 #define CONN_CANFSEND(so) (((so)->so_state & (SS_FCANTSENDMORE|SS_ISFCONNECTED)) == SS_ISFCONNECTED)
 213 #define CONN_CANFRCV(so) (((so)->so_state & (SS_FCANTRCVMORE|SS_ISFCONNECTED)) == SS_ISFCONNECTED)
 214 #define UPD_NFDS(x) if (nfds < (x)) nfds = (x)
 215
 216 /*
 217  * curtime kept to an accuracy of 1ms
 218  */
 219 #ifdef _WIN32
 220 static void updtime(void)
 221 {
 222     struct _timeb tb;
 223
 224     _ftime(&tb);
 225     curtime = (u_int)tb.time * (u_int)1000;
 226     curtime += (u_int)tb.millitm;
 227 }
 228 #else
 229 static void updtime(void)
 230 {
 231         gettimeofday(&tt, NULL);
 232
 233         curtime = (u_int)tt.tv_sec * (u_int)1000;
 234         curtime += (u_int)tt.tv_usec / (u_int)1000;
 235
 236         if ((tt.tv_usec % 1000) >= 500)
 237            curtime++;
 238 }
 239 #endif
 240
 241 void slirp_select_fill(int *pnfds,
 242                        fd_set *readfds, fd_set *writefds, fd_set *xfds)
 243 {
 244     struct socket *so, *so_next;
 245     struct timeval timeout;
 246     int nfds;
 247     int tmp_time;
 248
 249     /* fail safe */
 250     global_readfds = NULL;
 251     global_writefds = NULL;
 252     global_xfds = NULL;
 253
 254     nfds = *pnfds;
 255         /*
 256          * First, TCP sockets
 257          */
 258         do_slowtimo = 0;
 259         if (link_up) {
 260                 /*
 261                  * *_slowtimo needs calling if there are IP fragments
 262                  * in the fragment queue, or there are TCP connections active
 263                  */
 264                 do_slowtimo = ((tcb.so_next != &tcb) ||
 265                 (&ipq.ip_link != ipq.ip_link.next));
 266
 267                 for (so = tcb.so_next; so != &tcb; so = so_next) {
 268                         so_next = so->so_next;
 269
 270                         /*
 271                          * See if we need a tcp_fasttimo
 272                          */
 273                         if (time_fasttimo == 0 && so->so_tcpcb->t_flags & TF_DELACK)
 274                            time_fasttimo = curtime; /* Flag when we want a fasttimo */
 275
 276                         /*
 277                          * NOFDREF can include still connecting to local-host,
 278                          * newly socreated() sockets etc. Don't want to select these.
 279                          */
 280                         if (so->so_state & SS_NOFDREF || so->s == -1)
 281                            continue;
 282
 283                         /*
 284                          * Set for reading sockets which are accepting
 285                          */
 286                         if (so->so_state & SS_FACCEPTCONN) {
 287                                 FD_SET(so->s, readfds);
 288                                 UPD_NFDS(so->s);
 289                                 continue;
 290                         }
 291
 292                         /*
 293                          * Set for writing sockets which are connecting
 294                          */
 295                         if (so->so_state & SS_ISFCONNECTING) {
 296                                 FD_SET(so->s, writefds);
 297                                 UPD_NFDS(so->s);
 298                                 continue;
 299                         }
 300
 301                         /*
 302                          * Set for writing if we are connected, can send more, and
 303                          * we have something to send
 304                          */
 305                         if (CONN_CANFSEND(so) && so->so_rcv.sb_cc) {
 306                                 FD_SET(so->s, writefds);
 307                                 UPD_NFDS(so->s);
 308                         }
 309
 310                         /*
 311                          * Set for reading (and urgent data) if we are connected, can
 312                          * receive more, and we have room for it XXX /2 ?
 313                          */
 314                         if (CONN_CANFRCV(so) && (so->so_snd.sb_cc < (so->so_snd.sb_datalen/2))) {
 315                                 FD_SET(so->s, readfds);
 316                                 FD_SET(so->s, xfds);
 317                                 UPD_NFDS(so->s);
 318                         }
 319                 }
 320
 321                 /*
 322                  * UDP sockets
 323                  */
 324                 for (so = udb.so_next; so != &udb; so = so_next) {
 325                         so_next = so->so_next;
 326
 327                         /*
 328                          * See if it's timed out
 329                          */
 330                         if (so->so_expire) {
 331                                 if (so->so_expire <= curtime) {
 332                                         udp_detach(so);
 333                                         continue;
 334                                 } else
 335                                         do_slowtimo = 1; /* Let socket expire */
 336                         }
 337
 338                         /*
 339                          * When UDP packets are received from over the
 340                          * link, they're sendto()'d straight away, so
 341                          * no need for setting for writing
 342                          * Limit the number of packets queued by this session
 343                          * to 4.  Note that even though we try and limit this
 344                          * to 4 packets, the session could have more queued
 345                          * if the packets needed to be fragmented
 346                          * (XXX <= 4 ?)
 347                          */
 348                         if ((so->so_state & SS_ISFCONNECTED) && so->so_queued <= 4) {
 349                                 FD_SET(so->s, readfds);
 350                                 UPD_NFDS(so->s);
 351                         }
 352                 }
 353         }
 354
 355         /*
 356          * Setup timeout to use minimum CPU usage, especially when idle
 357          */
 358
 359         /*
 360          * First, see the timeout needed by *timo
 361          */
 362         timeout.tv_sec = 0;
 363         timeout.tv_usec = -1;
 364         /*
 365          * If a slowtimo is needed, set timeout to 500ms from the last
 366          * slow timeout. If a fast timeout is needed, set timeout within
 367          * 200ms of when it was requested.
 368          */
 369         if (do_slowtimo) {
 370                 /* XXX + 10000 because some select()'s aren't that accurate */
 371                 timeout.tv_usec = ((500 - (curtime - last_slowtimo)) * 1000) + 10000;
 372                 if (timeout.tv_usec < 0)
 373                    timeout.tv_usec = 0;
 374                 else if (timeout.tv_usec > 510000)
 375                    timeout.tv_usec = 510000;
 376
 377                 /* Can only fasttimo if we also slowtimo */
 378                 if (time_fasttimo) {
 379                         tmp_time = (200 - (curtime - time_fasttimo)) * 1000;
 380                         if (tmp_time < 0)
 381                            tmp_time = 0;
 382
 383                         /* Choose the smallest of the 2 */
 384                         if (tmp_time < timeout.tv_usec)
 385                            timeout.tv_usec = (u_int)tmp_time;
 386                 }
 387         }
 388         *pnfds = nfds;
 389 }
 390
 391 void slirp_select_poll(fd_set *readfds, fd_set *writefds, fd_set *xfds)
 392 {
 393     struct socket *so, *so_next;
 394     int ret;
 395
 396     global_readfds = readfds;
 397     global_writefds = writefds;
 398     global_xfds = xfds;
 399
 400         /* Update time */
 401         updtime();
 402
 403         /*
 404          * See if anything has timed out
 405          */
 406         if (link_up) {
 407                 if (time_fasttimo && ((curtime - time_fasttimo) >= 2)) {
 408                         tcp_fasttimo();
 409                         time_fasttimo = 0;
 410                 }
 411                 if (do_slowtimo && ((curtime - last_slowtimo) >= 499)) {
 412                         ip_slowtimo();
 413                         tcp_slowtimo();
 414                         last_slowtimo = curtime;
 415                 }
 416         }
 417
 418         /*
 419          * Check sockets
 420          */
 421         if (link_up) {
 422                 /*
 423                  * Check TCP sockets
 424                  */
 425                 for (so = tcb.so_next; so != &tcb; so = so_next) {
 426                         so_next = so->so_next;
 427
 428                         /*
 429                          * FD_ISSET is meaningless on these sockets
 430                          * (and they can crash the program)
 431                          */
 432                         if (so->so_state & SS_NOFDREF || so->s == -1)
 433                            continue;
 434
 435                         /*
 436                          * Check for URG data
 437                          * This will soread as well, so no need to
 438                          * test for readfds below if this succeeds
 439                          */
 440                         if (FD_ISSET(so->s, xfds))
 441                            sorecvoob(so);
 442                         /*
 443                          * Check sockets for reading
 444                          */
 445                         else if (FD_ISSET(so->s, readfds)) {
 446                                 /*
 447                                  * Check for incoming connections
 448                                  */
 449                                 if (so->so_state & SS_FACCEPTCONN) {
 450                                         tcp_connect(so);
 451                                         continue;
 452                                 } /* else */
 453                                 ret = soread(so);
 454
 455                                 /* Output it if we read something */
 456                                 if (ret > 0)
 457                                    tcp_output(sototcpcb(so));
 458                         }
 459
 460                         /*
 461                          * Check sockets for writing
 462                          */
 463                         if (FD_ISSET(so->s, writefds)) {
 464                           /*
 465                            * Check for non-blocking, still-connecting sockets
 466                            */
 467                           if (so->so_state & SS_ISFCONNECTING) {
 468                             /* Connected */
 469                             so->so_state &= ~SS_ISFCONNECTING;
 470
 471                             ret = send(so->s, (const void *) &ret, 0, 0);
 472                             if (ret < 0) {
 473                               /* XXXXX Must fix, zero bytes is a NOP */
 474                               if (errno == EAGAIN || errno == EWOULDBLOCK ||
 475                                   errno == EINPROGRESS || errno == ENOTCONN)
 476                                 continue;
 477
 478                               /* else failed */
 479                               so->so_state = SS_NOFDREF;
 480                             }
 481                             /* else so->so_state &= ~SS_ISFCONNECTING; */
 482
 483                             /*
 484                              * Continue tcp_input
 485                              */
 486                             tcp_input((struct mbuf *)NULL, sizeof(struct ip), so);
 487                             /* continue; */
 488                           } else
 489                             ret = sowrite(so);
 490                           /*
 491                            * XXXXX If we wrote something (a lot), there
 492                            * could be a need for a window update.
 493                            * In the worst case, the remote will send
 494                            * a window probe to get things going again
 495                            */
 496                         }
 497
 498                         /*
 499                          * Probe a still-connecting, non-blocking socket
 500                          * to check if it's still alive
 501                          */
 502 #ifdef PROBE_CONN
 503                         if (so->so_state & SS_ISFCONNECTING) {
 504                           ret = recv(so->s, (char *)&ret, 0,0);
 505
 506                           if (ret < 0) {
 507                             /* XXX */
 508                             if (errno == EAGAIN || errno == EWOULDBLOCK ||
 509                                 errno == EINPROGRESS || errno == ENOTCONN)
 510                               continue; /* Still connecting, continue */
 511
 512                             /* else failed */
 513                             so->so_state = SS_NOFDREF;
 514
 515                             /* tcp_input will take care of it */
 516                           } else {
 517                             ret = send(so->s, &ret, 0,0);
 518                             if (ret < 0) {
 519                               /* XXX */
 520                               if (errno == EAGAIN || errno == EWOULDBLOCK ||
 521                                   errno == EINPROGRESS || errno == ENOTCONN)
 522                                 continue;
 523                               /* else failed */
 524                               so->so_state = SS_NOFDREF;
 525                             } else
 526                               so->so_state &= ~SS_ISFCONNECTING;
 527
 528                           }
 529                           tcp_input((struct mbuf *)NULL, sizeof(struct ip),so);
 530                         } /* SS_ISFCONNECTING */
 531 #endif
 532                 }
 533
 534                 /*
 535                  * Now UDP sockets.
 536                  * Incoming packets are sent straight away, they're not buffered.
 537                  * Incoming UDP data isn't buffered either.
 538                  */
 539                 for (so = udb.so_next; so != &udb; so = so_next) {
 540                         so_next = so->so_next;
 541
 542                         if (so->s != -1 && FD_ISSET(so->s, readfds)) {
 543                             sorecvfrom(so);
 544                         }
 545                 }
 546         }
 547
 548         /*
 549          * See if we can start outputting
 550          */
 551         if (if_queued && link_up)
 552            if_start();
 553
 554         /* clear global file descriptor sets.
 555          * these reside on the stack in vl.c
 556          * so they're unusable if we're not in
 557          * slirp_select_fill or slirp_select_poll.
 558          */
 559          global_readfds = NULL;
 560          global_writefds = NULL;
 561          global_xfds = NULL;
 562 }
 563
 564 #define ETH_ALEN 6
 565 #define ETH_HLEN 14
 566
 567 #define ETH_P_IP        0x0800          /* Internet Protocol packet     */
 568 #define ETH_P_ARP       0x0806          /* Address Resolution packet    */
 569
 570 #define ARPOP_REQUEST   1               /* ARP request                  */
 571 #define ARPOP_REPLY     2               /* ARP reply                    */
 572
 573 struct ethhdr
 574 {
 575         unsigned char   h_dest[ETH_ALEN];       /* destination eth addr */
 576         unsigned char   h_source[ETH_ALEN];     /* source ether addr    */
 577         unsigned short  h_proto;                /* packet type ID field */
 578 };
 579
 580 struct arphdr
 581 {
 582         unsigned short  ar_hrd;         /* format of hardware address   */
 583         unsigned short  ar_pro;         /* format of protocol address   */
 584         unsigned char   ar_hln;         /* length of hardware address   */
 585         unsigned char   ar_pln;         /* length of protocol address   */
 586         unsigned short  ar_op;          /* ARP opcode (command)         */
 587
 588          /*
 589           *      Ethernet looks like this : This bit is variable sized however...
 590           */
 591         unsigned char           ar_sha[ETH_ALEN];       /* sender hardware address      */
 592         unsigned char           ar_sip[4];              /* sender IP address            */
 593         unsigned char           ar_tha[ETH_ALEN];       /* target hardware address      */
 594         unsigned char           ar_tip[4];              /* target IP address            */
 595 };
 596
 597 static void arp_input(const uint8_t *pkt, int pkt_len)
 598 {
 599     struct ethhdr *eh = (struct ethhdr *)pkt;
 600     struct arphdr *ah = (struct arphdr *)(pkt + ETH_HLEN);
 601     uint8_t arp_reply[ETH_HLEN + sizeof(struct arphdr)];
 602     struct ethhdr *reh = (struct ethhdr *)arp_reply;
 603     struct arphdr *rah = (struct arphdr *)(arp_reply + ETH_HLEN);
 604     int ar_op;
 605     struct ex_list *ex_ptr;
 606
 607     ar_op = ntohs(ah->ar_op);
 608     switch(ar_op) {
 609     case ARPOP_REQUEST:
 610         if (!memcmp(ah->ar_tip, &special_addr, 3)) {
 611             if (ah->ar_tip[3] == CTL_DNS || ah->ar_tip[3] == CTL_ALIAS)
 612                 goto arp_ok;
 613             for (ex_ptr = exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next) {
 614                 if (ex_ptr->ex_addr == ah->ar_tip[3])
 615                     goto arp_ok;
 616             }
 617             return;
 618         arp_ok:
 619             /* XXX: make an ARP request to have the client address */
 620             memcpy(client_ethaddr, eh->h_source, ETH_ALEN);
 621
 622             /* ARP request for alias/dns mac address */
 623             memcpy(reh->h_dest, pkt + ETH_ALEN, ETH_ALEN);
 624             memcpy(reh->h_source, special_ethaddr, ETH_ALEN - 1);
 625             reh->h_source[5] = ah->ar_tip[3];
 626             reh->h_proto = htons(ETH_P_ARP);
 627
 628             rah->ar_hrd = htons(1);
 629             rah->ar_pro = htons(ETH_P_IP);
 630             rah->ar_hln = ETH_ALEN;
 631             rah->ar_pln = 4;
 632             rah->ar_op = htons(ARPOP_REPLY);
 633             memcpy(rah->ar_sha, reh->h_source, ETH_ALEN);
 634             memcpy(rah->ar_sip, ah->ar_tip, 4);
 635             memcpy(rah->ar_tha, ah->ar_sha, ETH_ALEN);
 636             memcpy(rah->ar_tip, ah->ar_sip, 4);
 637             slirp_output(arp_reply, sizeof(arp_reply));
 638         }
 639         break;
 640     case ARPOP_REPLY:
 641         /* reply to request of client mac address ? */
 642         if (!memcmp(client_ethaddr, zero_ethaddr, ETH_ALEN) &&
 643             !memcmp(ah->ar_sip, &client_ipaddr.s_addr, 4)) {
 644             memcpy(client_ethaddr, ah->ar_sha, ETH_ALEN);
 645         }
 646         break;
 647     default:
 648         break;
 649     }
 650 }
 651
 652 void slirp_input(const uint8_t *pkt, int pkt_len)
 653 {
 654     struct mbuf *m;
 655     int proto;
 656
 657     if (pkt_len < ETH_HLEN)
 658         return;
 659
 660     proto = ntohs(*(uint16_t *)(pkt + 12));
 661     switch(proto) {
 662     case ETH_P_ARP:
 663         arp_input(pkt, pkt_len);
 664         break;
 665     case ETH_P_IP:
 666         m = m_get();
 667         if (!m)
 668             return;
 669         /* Note: we add to align the IP header */
 670         if (M_FREEROOM(m) < pkt_len + 2) {
 671             m_inc(m, pkt_len + 2);
 672         }
 673         m->m_len = pkt_len + 2;
 674         memcpy(m->m_data + 2, pkt, pkt_len);
 675
 676         m->m_data += 2 + ETH_HLEN;
 677         m->m_len -= 2 + ETH_HLEN;
 678
 679         ip_input(m);
 680         break;
 681     default:
 682         break;
 683     }
 684 }
 685
 686 /* output the IP packet to the ethernet device */
 687 void if_encap(const uint8_t *ip_data, int ip_data_len)
 688 {
 689     uint8_t buf[1600];
 690     struct ethhdr *eh = (struct ethhdr *)buf;
 691
 692     if (ip_data_len + ETH_HLEN > sizeof(buf))
 693         return;
 694
 695     if (!memcmp(client_ethaddr, zero_ethaddr, ETH_ALEN)) {
 696         uint8_t arp_req[ETH_HLEN + sizeof(struct arphdr)];
 697         struct ethhdr *reh = (struct ethhdr *)arp_req;
 698         struct arphdr *rah = (struct arphdr *)(arp_req + ETH_HLEN);
 699         const struct ip *iph = (const struct ip *)ip_data;
 700
 701         /* If the client addr is not known, there is no point in
 702            sending the packet to it. Normally the sender should have
 703            done an ARP request to get its MAC address. Here we do it
 704            in place of sending the packet and we hope that the sender
 705            will retry sending its packet. */
 706         memset(reh->h_dest, 0xff, ETH_ALEN);
 707         memcpy(reh->h_source, special_ethaddr, ETH_ALEN - 1);
 708         reh->h_source[5] = CTL_ALIAS;
 709         reh->h_proto = htons(ETH_P_ARP);
 710         rah->ar_hrd = htons(1);
 711         rah->ar_pro = htons(ETH_P_IP);
 712         rah->ar_hln = ETH_ALEN;
 713         rah->ar_pln = 4;
 714         rah->ar_op = htons(ARPOP_REQUEST);
 715         /* source hw addr */
 716         memcpy(rah->ar_sha, special_ethaddr, ETH_ALEN - 1);
 717         rah->ar_sha[5] = CTL_ALIAS;
 718         /* source IP */
 719         memcpy(rah->ar_sip, &alias_addr, 4);
 720         /* target hw addr (none) */
 721         memset(rah->ar_tha, 0, ETH_ALEN);
 722         /* target IP */
 723         memcpy(rah->ar_tip, &iph->ip_dst, 4);
 724         client_ipaddr = iph->ip_dst;
 725         slirp_output(arp_req, sizeof(arp_req));
 726     } else {
 727         memcpy(eh->h_dest, client_ethaddr, ETH_ALEN);
 728         memcpy(eh->h_source, special_ethaddr, ETH_ALEN - 1);
 729         /* XXX: not correct */
 730         eh->h_source[5] = CTL_ALIAS;
 731         eh->h_proto = htons(ETH_P_IP);
 732         memcpy(buf + sizeof(struct ethhdr), ip_data, ip_data_len);
 733         slirp_output(buf, ip_data_len + ETH_HLEN);
 734     }
 735 }
 736
 737 static void _slirp_redir_loop(void (*func)(void *opaque, int is_udp,
 738                                            struct in_addr *laddr, u_int lport,
 739                                            struct in_addr *faddr, u_int fport),
 740                               void *opaque, int is_udp)
 741 {
 742     struct socket *head = (is_udp ? &udb : &tcb);
 743     struct socket *so;
 744
 745     for (so = head->so_next; so != head; so = so->so_next) {
 746         func(opaque, is_udp,
 747              &so->so_laddr, ntohs(so->so_lport),
 748              &so->so_faddr, ntohs(so->so_fport));
 749     }
 750 }
 751
 752 void slirp_redir_loop(void (*func)(void *opaque, int is_udp,
 753                                   struct in_addr *laddr, u_int lport,
 754                                   struct in_addr *faddr, u_int fport),
 755                      void *opaque)
 756 {
 757     _slirp_redir_loop(func, opaque, 0);
 758     _slirp_redir_loop(func, opaque, 1);
 759 }
 760
 761 /* Unlistens a redirection
 762  *
 763  * Return value: number of redirs removed */
 764 int slirp_redir_rm(int is_udp, int host_port)
 765 {
 766     struct socket *so;
 767     struct socket *head = (is_udp ? &udb : &tcb);
 768     int fport = htons(host_port);
 769     int n = 0;
 770
 771  loop_again:
 772     for (so = head->so_next; so != head; so = so->so_next) {
 773         if (so->so_fport == fport) {
 774             close(so->s);
 775             sofree(so);
 776             n++;
 777             goto loop_again;
 778         }
 779     }
 780
 781     return n;
 782 }
 783
 784 int slirp_redir(int is_udp, int host_port,
 785                 struct in_addr guest_addr, int guest_port)
 786 {
 787     if (is_udp) {
 788         if (!udp_listen(htons(host_port), guest_addr.s_addr,
 789                         htons(guest_port), 0))
 790             return -1;
 791     } else {
 792         if (!solisten(htons(host_port), guest_addr.s_addr,
 793                       htons(guest_port), 0))
 794             return -1;
 795     }
 796     return 0;
 797 }
 798
 799 int slirp_add_exec(int do_pty, const void *args, int addr_low_byte,
 800                   int guest_port)
 801 {
 802     return add_exec(&exec_list, do_pty, (char *)args,
 803                     addr_low_byte, htons(guest_port));
 804 }
 805
 806 ssize_t slirp_send(struct socket *so, const void *buf, size_t len, int flags)
 807 {
 808         if (so->s == -1 && so->extra) {
 809                 qemu_chr_write(so->extra, buf, len);
 810                 return len;
 811         }
 812
 813         return send(so->s, buf, len, flags);
 814 }
 815
 816 static struct socket *slirp_find_ctl_socket(int addr_low_byte, int guest_port)
 817 {
 818         struct socket *so;
 819
 820         for (so = tcb.so_next; so != &tcb; so = so->so_next) {
 821                 if ((so->so_faddr.s_addr & htonl(0xffffff00)) ==
 822                                 special_addr.s_addr
 823                                 && (ntohl(so->so_faddr.s_addr) & 0xff) ==
 824                                 addr_low_byte
 825                                 && htons(so->so_fport) == guest_port)
 826                         return so;
 827         }
 828
 829         return NULL;
 830 }
 831
 832 size_t slirp_socket_can_recv(int addr_low_byte, int guest_port)
 833 {
 834         struct iovec iov[2];
 835         struct socket *so;
 836
 837     if (!link_up)
 838         return 0;
 839
 840         so = slirp_find_ctl_socket(addr_low_byte, guest_port);
 841
 842         if (!so || so->so_state & SS_NOFDREF)
 843                 return 0;
 844
 845         if (!CONN_CANFRCV(so) || so->so_snd.sb_cc >= (so->so_snd.sb_datalen/2))
 846                 return 0;
 847
 848         return sopreprbuf(so, iov, NULL);
 849 }
 850
 851 void slirp_socket_recv(int addr_low_byte, int guest_port, const uint8_t *buf,
 852         int size)
 853 {
 854     int ret;
 855     struct socket *so = slirp_find_ctl_socket(addr_low_byte, guest_port);
 856
 857     if (!so)
 858         return;
 859
 860     ret = soreadbuf(so, (const char *)buf, size);
 861
 862     if (ret > 0)
 863         tcp_output(sototcpcb(so));
 864 }
 865
 866 static void slirp_tcp_save(QEMUFile *f, struct tcpcb *tp)
 867 {
 868     int i;
 869
 870     qemu_put_sbe16(f, tp->t_state);
 871     for (i = 0; i < TCPT_NTIMERS; i++)
 872         qemu_put_sbe16(f, tp->t_timer[i]);
 873     qemu_put_sbe16(f, tp->t_rxtshift);
 874     qemu_put_sbe16(f, tp->t_rxtcur);
 875     qemu_put_sbe16(f, tp->t_dupacks);
 876     qemu_put_be16(f, tp->t_maxseg);
 877     qemu_put_sbyte(f, tp->t_force);
 878     qemu_put_be16(f, tp->t_flags);
 879     qemu_put_be32(f, tp->snd_una);
 880     qemu_put_be32(f, tp->snd_nxt);
 881     qemu_put_be32(f, tp->snd_up);
 882     qemu_put_be32(f, tp->snd_wl1);
 883     qemu_put_be32(f, tp->snd_wl2);
 884     qemu_put_be32(f, tp->iss);
 885     qemu_put_be32(f, tp->snd_wnd);
 886     qemu_put_be32(f, tp->rcv_wnd);
 887     qemu_put_be32(f, tp->rcv_nxt);
 888     qemu_put_be32(f, tp->rcv_up);
 889     qemu_put_be32(f, tp->irs);
 890     qemu_put_be32(f, tp->rcv_adv);
 891     qemu_put_be32(f, tp->snd_max);
 892     qemu_put_be32(f, tp->snd_cwnd);
 893     qemu_put_be32(f, tp->snd_ssthresh);
 894     qemu_put_sbe16(f, tp->t_idle);
 895     qemu_put_sbe16(f, tp->t_rtt);
 896     qemu_put_be32(f, tp->t_rtseq);
 897     qemu_put_sbe16(f, tp->t_srtt);
 898     qemu_put_sbe16(f, tp->t_rttvar);
 899     qemu_put_be16(f, tp->t_rttmin);
 900     qemu_put_be32(f, tp->max_sndwnd);
 901     qemu_put_byte(f, tp->t_oobflags);
 902     qemu_put_byte(f, tp->t_iobc);
 903     qemu_put_sbe16(f, tp->t_softerror);
 904     qemu_put_byte(f, tp->snd_scale);
 905     qemu_put_byte(f, tp->rcv_scale);
 906     qemu_put_byte(f, tp->request_r_scale);
 907     qemu_put_byte(f, tp->requested_s_scale);
 908     qemu_put_be32(f, tp->ts_recent);
 909     qemu_put_be32(f, tp->ts_recent_age);
 910     qemu_put_be32(f, tp->last_ack_sent);
 911 }
 912
 913 static void slirp_sbuf_save(QEMUFile *f, struct sbuf *sbuf)
 914 {
 915     uint32_t off;
 916
 917     qemu_put_be32(f, sbuf->sb_cc);
 918     qemu_put_be32(f, sbuf->sb_datalen);
 919     off = (uint32_t)(sbuf->sb_wptr - sbuf->sb_data);
 920     qemu_put_sbe32(f, off);
 921     off = (uint32_t)(sbuf->sb_rptr - sbuf->sb_data);
 922     qemu_put_sbe32(f, off);
 923     qemu_put_buffer(f, (unsigned char*)sbuf->sb_data, sbuf->sb_datalen);
 924 }
 925
 926 static void slirp_socket_save(QEMUFile *f, struct socket *so)
 927 {
 928     qemu_put_be32(f, so->so_urgc);
 929     qemu_put_be32(f, so->so_faddr.s_addr);
 930     qemu_put_be32(f, so->so_laddr.s_addr);
 931     qemu_put_be16(f, so->so_fport);
 932     qemu_put_be16(f, so->so_lport);
 933     qemu_put_byte(f, so->so_iptos);
 934     qemu_put_byte(f, so->so_emu);
 935     qemu_put_byte(f, so->so_type);
 936     qemu_put_be32(f, so->so_state);
 937     slirp_sbuf_save(f, &so->so_rcv);
 938     slirp_sbuf_save(f, &so->so_snd);
 939     slirp_tcp_save(f, so->so_tcpcb);
 940 }
 941
 942 static void slirp_state_save(QEMUFile *f, void *opaque)
 943 {
 944     struct ex_list *ex_ptr;
 945
 946     for (ex_ptr = exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next)
 947         if (ex_ptr->ex_pty == 3) {
 948             struct socket *so;
 949             so = slirp_find_ctl_socket(ex_ptr->ex_addr, ntohs(ex_ptr->ex_fport));
 950             if (!so)
 951                 continue;
 952
 953             qemu_put_byte(f, 42);
 954             slirp_socket_save(f, so);
 955         }
 956     qemu_put_byte(f, 0);
 957 }
 958
 959 static void slirp_tcp_load(QEMUFile *f, struct tcpcb *tp)
 960 {
 961     int i;
 962
 963     tp->t_state = qemu_get_sbe16(f);
 964     for (i = 0; i < TCPT_NTIMERS; i++)
 965         tp->t_timer[i] = qemu_get_sbe16(f);
 966     tp->t_rxtshift = qemu_get_sbe16(f);
 967     tp->t_rxtcur = qemu_get_sbe16(f);
 968     tp->t_dupacks = qemu_get_sbe16(f);
 969     tp->t_maxseg = qemu_get_be16(f);
 970     tp->t_force = qemu_get_sbyte(f);
 971     tp->t_flags = qemu_get_be16(f);
 972     tp->snd_una = qemu_get_be32(f);
 973     tp->snd_nxt = qemu_get_be32(f);
 974     tp->snd_up = qemu_get_be32(f);
 975     tp->snd_wl1 = qemu_get_be32(f);
 976     tp->snd_wl2 = qemu_get_be32(f);
 977     tp->iss = qemu_get_be32(f);
 978     tp->snd_wnd = qemu_get_be32(f);
 979     tp->rcv_wnd = qemu_get_be32(f);
 980     tp->rcv_nxt = qemu_get_be32(f);
 981     tp->rcv_up = qemu_get_be32(f);
 982     tp->irs = qemu_get_be32(f);
 983     tp->rcv_adv = qemu_get_be32(f);
 984     tp->snd_max = qemu_get_be32(f);
 985     tp->snd_cwnd = qemu_get_be32(f);
 986     tp->snd_ssthresh = qemu_get_be32(f);
 987     tp->t_idle = qemu_get_sbe16(f);
 988     tp->t_rtt = qemu_get_sbe16(f);
 989     tp->t_rtseq = qemu_get_be32(f);
 990     tp->t_srtt = qemu_get_sbe16(f);
 991     tp->t_rttvar = qemu_get_sbe16(f);
 992     tp->t_rttmin = qemu_get_be16(f);
 993     tp->max_sndwnd = qemu_get_be32(f);
 994     tp->t_oobflags = qemu_get_byte(f);
 995     tp->t_iobc = qemu_get_byte(f);
 996     tp->t_softerror = qemu_get_sbe16(f);
 997     tp->snd_scale = qemu_get_byte(f);
 998     tp->rcv_scale = qemu_get_byte(f);
 999     tp->request_r_scale = qemu_get_byte(f);
1000     tp->requested_s_scale = qemu_get_byte(f);
1001     tp->ts_recent = qemu_get_be32(f);
1002     tp->ts_recent_age = qemu_get_be32(f);
1003     tp->last_ack_sent = qemu_get_be32(f);
1004     tcp_template(tp);
1005 }
1006
1007 static int slirp_sbuf_load(QEMUFile *f, struct sbuf *sbuf)
1008 {
1009     uint32_t off, sb_cc, sb_datalen;
1010
1011     sb_cc = qemu_get_be32(f);
1012     sb_datalen = qemu_get_be32(f);
1013
1014     sbreserve(sbuf, sb_datalen);
1015
1016     if (sbuf->sb_datalen != sb_datalen)
1017         return -ENOMEM;
1018
1019     sbuf->sb_cc = sb_cc;
1020
1021     off = qemu_get_sbe32(f);
1022     sbuf->sb_wptr = sbuf->sb_data + off;
1023     off = qemu_get_sbe32(f);
1024     sbuf->sb_rptr = sbuf->sb_data + off;
1025     qemu_get_buffer(f, (unsigned char*)sbuf->sb_data, sbuf->sb_datalen);
1026
1027     return 0;
1028 }
1029
1030 static int slirp_socket_load(QEMUFile *f, struct socket *so)
1031 {
1032     if (tcp_attach(so) < 0)
1033         return -ENOMEM;
1034
1035     so->so_urgc = qemu_get_be32(f);
1036     so->so_faddr.s_addr = qemu_get_be32(f);
1037     so->so_laddr.s_addr = qemu_get_be32(f);
1038     so->so_fport = qemu_get_be16(f);
1039     so->so_lport = qemu_get_be16(f);
1040     so->so_iptos = qemu_get_byte(f);
1041     so->so_emu = qemu_get_byte(f);
1042     so->so_type = qemu_get_byte(f);
1043     so->so_state = qemu_get_be32(f);
1044     if (slirp_sbuf_load(f, &so->so_rcv) < 0)
1045         return -ENOMEM;
1046     if (slirp_sbuf_load(f, &so->so_snd) < 0)
1047         return -ENOMEM;
1048     slirp_tcp_load(f, so->so_tcpcb);
1049
1050     return 0;
1051 }
1052
1053 static int slirp_state_load(QEMUFile *f, void *opaque, int version_id)
1054 {
1055     struct ex_list *ex_ptr;
1056     int r;
1057
1058     while ((r = qemu_get_byte(f))) {
1059         int ret;
1060         struct socket *so = socreate();
1061
1062         if (!so)
1063             return -ENOMEM;
1064
1065         ret = slirp_socket_load(f, so);
1066
1067         if (ret < 0)
1068             return ret;
1069
1070         if ((so->so_faddr.s_addr & htonl(0xffffff00)) != special_addr.s_addr)
1071             return -EINVAL;
1072
1073         for (ex_ptr = exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next)
1074             if (ex_ptr->ex_pty == 3 &&
1075                     (ntohl(so->so_faddr.s_addr) & 0xff) == ex_ptr->ex_addr &&
1076                     so->so_fport == ex_ptr->ex_fport)
1077                 break;
1078
1079         if (!ex_ptr)
1080             return -EINVAL;
1081
1082         so->extra = (void *)ex_ptr->ex_exec;
1083     }
1084
1085     return 0;
1086 }