usr.sbin/faithd/ftp.c

   1 /*      $KAME: ftp.c,v 1.11 2001/07/02 14:36:49 itojun Exp $    */
   2
   3 /*
   4  * Copyright (C) 1997 and 1998 WIDE Project.
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the project nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  * $FreeBSD: src/usr.sbin/faithd/ftp.c,v 1.2.2.5 2002/04/28 05:40:29 suz Exp $
  32  * $DragonFly: src/usr.sbin/faithd/ftp.c,v 1.4 2003/11/16 14:10:45 eirikn Exp $
  33  */
  34
  35 #include <sys/param.h>
  36 #include <sys/types.h>
  37 #include <sys/socket.h>
  38 #include <sys/ioctl.h>
  39 #include <sys/time.h>
  40
  41 #include <stdio.h>
  42 #include <stdlib.h>
  43 #include <string.h>
  44 #include <syslog.h>
  45 #include <unistd.h>
  46 #include <errno.h>
  47 #include <ctype.h>
  48
  49 #include <netinet/in.h>
  50 #include <arpa/inet.h>
  51 #include <netdb.h>
  52
  53 #include "faithd.h"
  54
  55 static char rbuf[MSS];
  56 static char sbuf[MSS];
  57 static int passivemode = 0;
  58 static int wport4 = -1;                 /* listen() to active */
  59 static int wport6 = -1;                 /* listen() to passive */
  60 static int port4 = -1;                  /* active: inbound  passive: outbound */
  61 static int port6 = -1;                  /* active: outbound  passive: inbound */
  62 static struct sockaddr_storage data4;   /* server data address */
  63 static struct sockaddr_storage data6;   /* client data address */
  64 static int epsvall = 0;
  65
  66 #ifdef FAITH4
  67 enum state { NONE, LPRT, EPRT, PORT, LPSV, EPSV, PASV };
  68 #else
  69 enum state { NONE, LPRT, EPRT, LPSV, EPSV };
  70 #endif
  71
  72 static int ftp_activeconn(void);
  73 static int ftp_passiveconn(void);
  74 static int ftp_copy(int, int);
  75 static int ftp_copyresult(int, int, enum state);
  76 static int ftp_copycommand(int, int, enum state *);
  77
  78 void
  79 ftp_relay(int ctl6, int ctl4)
  80 {
  81         fd_set readfds;
  82         int error;
  83         enum state state = NONE;
  84         struct timeval tv;
  85
  86         syslog(LOG_INFO, "starting ftp control connection");
  87
  88         for (;;) {
  89                 FD_ZERO(&readfds);
  90                 FD_SET(ctl4, &readfds);
  91                 FD_SET(ctl6, &readfds);
  92                 if (0 <= port4)
  93                         FD_SET(port4, &readfds);
  94                 if (0 <= port6)
  95                         FD_SET(port6, &readfds);
  96 #if 0
  97                 if (0 <= wport4)
  98                         FD_SET(wport4, &readfds);
  99                 if (0 <= wport6)
 100                         FD_SET(wport6, &readfds);
 101 #endif
 102                 tv.tv_sec = FAITH_TIMEOUT;
 103                 tv.tv_usec = 0;
 104
 105                 error = select(256, &readfds, NULL, NULL, &tv);
 106                 if (error == -1)
 107                         exit_failure("select: %s", strerror(errno));
 108                 else if (error == 0)
 109                         exit_failure("connection timeout");
 110
 111                 /*
 112                  * The order of the following checks does (slightly) matter.
 113                  * It is important to visit all checks (do not use "continue"),
 114                  * otherwise some of the pipe may become full and we cannot
 115                  * relay correctly.
 116                  */
 117                 if (FD_ISSET(ctl6, &readfds)) {
 118                         /*
 119                          * copy control connection from the client.
 120                          * command translation is necessary.
 121                          */
 122                         error = ftp_copycommand(ctl6, ctl4, &state);
 123
 124                         switch (error) {
 125                         case -1:
 126                                 goto bad;
 127                         case 0:
 128                                 close(ctl4);
 129                                 close(ctl6);
 130                                 exit_success("terminating ftp control connection");
 131                                 /*NOTREACHED*/
 132                         default:
 133                                 break;
 134                         }
 135                 }
 136                 if (FD_ISSET(ctl4, &readfds)) {
 137                         /*
 138                          * copy control connection from the server
 139                          * translation of result code is necessary.
 140                          */
 141                         error = ftp_copyresult(ctl4, ctl6, state);
 142
 143                         switch (error) {
 144                         case -1:
 145                                 goto bad;
 146                         case 0:
 147                                 close(ctl4);
 148                                 close(ctl6);
 149                                 exit_success("terminating ftp control connection");
 150                                 /*NOTREACHED*/
 151                         default:
 152                                 break;
 153                         }
 154                 }
 155                 if (0 <= port4 && 0 <= port6 && FD_ISSET(port4, &readfds)) {
 156                         /*
 157                          * copy data connection.
 158                          * no special treatment necessary.
 159                          */
 160                         if (FD_ISSET(port4, &readfds))
 161                                 error = ftp_copy(port4, port6);
 162                         switch (error) {
 163                         case -1:
 164                                 goto bad;
 165                         case 0:
 166                                 close(port4);
 167                                 close(port6);
 168                                 port4 = port6 = -1;
 169                                 syslog(LOG_INFO, "terminating data connection");
 170                                 break;
 171                         default:
 172                                 break;
 173                         }
 174                 }
 175                 if (0 <= port4 && 0 <= port6 && FD_ISSET(port6, &readfds)) {
 176                         /*
 177                          * copy data connection.
 178                          * no special treatment necessary.
 179                          */
 180                         if (FD_ISSET(port6, &readfds))
 181                                 error = ftp_copy(port6, port4);
 182                         switch (error) {
 183                         case -1:
 184                                 goto bad;
 185                         case 0:
 186                                 close(port4);
 187                                 close(port6);
 188                                 port4 = port6 = -1;
 189                                 syslog(LOG_INFO, "terminating data connection");
 190                                 break;
 191                         default:
 192                                 break;
 193                         }
 194                 }
 195 #if 0
 196                 if (wport4 && FD_ISSET(wport4, &readfds)) {
 197                         /*
 198                          * establish active data connection from the server.
 199                          */
 200                         ftp_activeconn();
 201                 }
 202                 if (wport6 && FD_ISSET(wport6, &readfds)) {
 203                         /*
 204                          * establish passive data connection from the client.
 205                          */
 206                         ftp_passiveconn();
 207                 }
 208 #endif
 209         }
 210
 211  bad:
 212         exit_failure("%s", strerror(errno));
 213 }
 214
 215 static int
 216 ftp_activeconn(void)
 217 {
 218         int n;
 219         int error;
 220         fd_set set;
 221         struct timeval timeout;
 222         struct sockaddr *sa;
 223
 224         /* get active connection from server */
 225         FD_ZERO(&set);
 226         FD_SET(wport4, &set);
 227         timeout.tv_sec = 120;
 228         timeout.tv_usec = -1;
 229         n = sizeof(data4);
 230         if (select(wport4 + 1, &set, NULL, NULL, &timeout) == 0
 231          || (port4 = accept(wport4, (struct sockaddr *)&data4, &n)) < 0) {
 232                 close(wport4);
 233                 wport4 = -1;
 234                 syslog(LOG_INFO, "active mode data connection failed");
 235                 return -1;
 236         }
 237
 238         /* ask active connection to client */
 239         sa = (struct sockaddr *)&data6;
 240         port6 = socket(sa->sa_family, SOCK_STREAM, 0);
 241         if (port6 == -1) {
 242                 close(port4);
 243                 close(wport4);
 244                 port4 = wport4 = -1;
 245                 syslog(LOG_INFO, "active mode data connection failed");
 246                 return -1;
 247         }
 248         error = connect(port6, sa, sa->sa_len);
 249         if (error < 0) {
 250                 close(port6);
 251                 close(port4);
 252                 close(wport4);
 253                 port6 = port4 = wport4 = -1;
 254                 syslog(LOG_INFO, "active mode data connection failed");
 255                 return -1;
 256         }
 257
 258         syslog(LOG_INFO, "active mode data connection established");
 259         return 0;
 260 }
 261
 262 static int
 263 ftp_passiveconn(void)
 264 {
 265         int n;
 266         int error;
 267         fd_set set;
 268         struct timeval timeout;
 269         struct sockaddr *sa;
 270
 271         /* get passive connection from client */
 272         FD_ZERO(&set);
 273         FD_SET(wport6, &set);
 274         timeout.tv_sec = 120;
 275         timeout.tv_usec = 0;
 276         n = sizeof(data6);
 277         if (select(wport6 + 1, &set, NULL, NULL, &timeout) == 0
 278          || (port6 = accept(wport6, (struct sockaddr *)&data6, &n)) < 0) {
 279                 close(wport6);
 280                 wport6 = -1;
 281                 syslog(LOG_INFO, "passive mode data connection failed");
 282                 return -1;
 283         }
 284
 285         /* ask passive connection to server */
 286         sa = (struct sockaddr *)&data4;
 287         port4 = socket(sa->sa_family, SOCK_STREAM, 0);
 288         if (port4 == -1) {
 289                 close(wport6);
 290                 close(port6);
 291                 wport6 = port6 = -1;
 292                 syslog(LOG_INFO, "passive mode data connection failed");
 293                 return -1;
 294         }
 295         error = connect(port4, sa, sa->sa_len);
 296         if (error < 0) {
 297                 close(wport6);
 298                 close(port4);
 299                 close(port6);
 300                 wport6 = port4 = port6 = -1;
 301                 syslog(LOG_INFO, "passive mode data connection failed");
 302                 return -1;
 303         }
 304
 305         syslog(LOG_INFO, "passive mode data connection established");
 306         return 0;
 307 }
 308
 309 static int
 310 ftp_copy(int src, int dst)
 311 {
 312         int error, atmark;
 313         int n;
 314
 315         /* OOB data handling */
 316         error = ioctl(src, SIOCATMARK, &atmark);
 317         if (error != -1 && atmark == 1) {
 318                 n = read(src, rbuf, 1);
 319                 if (n == -1)
 320                         goto bad;
 321                 send(dst, rbuf, n, MSG_OOB);
 322 #if 0
 323                 n = read(src, rbuf, sizeof(rbuf));
 324                 if (n == -1)
 325                         goto bad;
 326                 write(dst, rbuf, n);
 327                 return n;
 328 #endif
 329         }
 330
 331         n = read(src, rbuf, sizeof(rbuf));
 332         switch (n) {
 333         case -1:
 334         case 0:
 335                 return n;
 336         default:
 337                 write(dst, rbuf, n);
 338                 return n;
 339         }
 340
 341  bad:
 342         exit_failure("%s", strerror(errno));
 343         /*NOTREACHED*/
 344         return 0;       /* to make gcc happy */
 345 }
 346
 347 static int
 348 ftp_copyresult(int src, int dst, enum state state)
 349 {
 350         int error, atmark;
 351         int n;
 352         char *param;
 353         int code;
 354
 355         /* OOB data handling */
 356         error = ioctl(src, SIOCATMARK, &atmark);
 357         if (error != -1 && atmark == 1) {
 358                 n = read(src, rbuf, 1);
 359                 if (n == -1)
 360                         goto bad;
 361                 send(dst, rbuf, n, MSG_OOB);
 362 #if 0
 363                 n = read(src, rbuf, sizeof(rbuf));
 364                 if (n == -1)
 365                         goto bad;
 366                 write(dst, rbuf, n);
 367                 return n;
 368 #endif
 369         }
 370
 371         n = read(src, rbuf, sizeof(rbuf));
 372         if (n <= 0)
 373                 return n;
 374         rbuf[n] = '\0';
 375
 376         /*
 377          * parse argument
 378          */
 379     {
 380         char *p;
 381         int i;
 382
 383         p = rbuf;
 384         for (i = 0; i < 3; i++) {
 385                 if (!isdigit(*p)) {
 386                         /* invalid reply */
 387                         write(dst, rbuf, n);
 388                         return n;
 389                 }
 390                 p++;
 391         }
 392         if (!isspace(*p)) {
 393                 /* invalid reply */
 394                 write(dst, rbuf, n);
 395                 return n;
 396         }
 397         code = atoi(rbuf);
 398         param = p;
 399         /* param points to first non-command token, if any */
 400         while (*param && isspace(*param))
 401                 param++;
 402         if (!*param)
 403                 param = NULL;
 404     }
 405
 406         switch (state) {
 407         case NONE:
 408                 if (!passivemode && rbuf[0] == '1') {
 409                         if (ftp_activeconn() < 0) {
 410                                 n = snprintf(rbuf, sizeof(rbuf),
 411                                         "425 Cannot open data connetion\r\n");
 412                         }
 413                 }
 414                 write(dst, rbuf, n);
 415                 return n;
 416         case LPRT:
 417         case EPRT:
 418                 /* expecting "200 PORT command successful." */
 419                 if (code == 200) {
 420                         char *p;
 421
 422                         p = strstr(rbuf, "PORT");
 423                         if (p) {
 424                                 p[0] = (state == LPRT) ? 'L' : 'E';
 425                                 p[1] = 'P';
 426                         }
 427                 } else {
 428                         close(wport4);
 429                         wport4 = -1;
 430                 }
 431                 write(dst, rbuf, n);
 432                 return n;
 433 #ifdef FAITH4
 434         case PORT:
 435                 /* expecting "200 EPRT command successful." */
 436                 if (code == 200) {
 437                         char *p;
 438
 439                         p = strstr(rbuf, "EPRT");
 440                         if (p) {
 441                                 p[0] = 'P';
 442                                 p[1] = 'O';
 443                         }
 444                 } else {
 445                         close(wport4);
 446                         wport4 = -1;
 447                 }
 448                 write(dst, rbuf, n);
 449                 return n;
 450 #endif
 451         case LPSV:
 452         case EPSV:
 453                 /*
 454                  * expecting "227 Entering Passive Mode (x,x,x,x,x,x,x)"
 455                  * (in some cases result comes without paren)
 456                  */
 457                 if (code != 227) {
 458 passivefail0:
 459                         close(wport6);
 460                         wport6 = -1;
 461                         write(dst, rbuf, n);
 462                         return n;
 463                 }
 464
 465             {
 466                 unsigned int ho[4], po[2];
 467                 struct sockaddr_in *sin;
 468                 struct sockaddr_in6 *sin6;
 469                 u_short port;
 470                 char *p;
 471
 472                 /*
 473                  * PASV result -> LPSV/EPSV result
 474                  */
 475                 p = param;
 476                 while (*p && *p != '(' && !isdigit(*p)) /*)*/
 477                         p++;
 478                 if (!*p)
 479                         goto passivefail0;      /*XXX*/
 480                 if (*p == '(')  /*)*/
 481                         p++;
 482                 n = sscanf(p, "%u,%u,%u,%u,%u,%u",
 483                         &ho[0], &ho[1], &ho[2], &ho[3], &po[0], &po[1]);
 484                 if (n != 6)
 485                         goto passivefail0;      /*XXX*/
 486
 487                 /* keep PORT parameter */
 488                 memset(&data4, 0, sizeof(data4));
 489                 sin = (struct sockaddr_in *)&data4;
 490                 sin->sin_len = sizeof(*sin);
 491                 sin->sin_family = AF_INET;
 492                 sin->sin_addr.s_addr = 0;
 493                 for (n = 0; n < 4; n++) {
 494                         sin->sin_addr.s_addr |=
 495                                 htonl((ho[n] & 0xff) << ((3 - n) * 8));
 496                 }
 497                 sin->sin_port = htons(((po[0] & 0xff) << 8) | (po[1] & 0xff));
 498
 499                 /* get ready for passive data connection */
 500                 memset(&data6, 0, sizeof(data6));
 501                 sin6 = (struct sockaddr_in6 *)&data6;
 502                 sin6->sin6_len = sizeof(*sin6);
 503                 sin6->sin6_family = AF_INET6;
 504                 wport6 = socket(sin6->sin6_family, SOCK_STREAM, 0);
 505                 if (wport6 == -1) {
 506 passivefail:
 507                         n = snprintf(sbuf, sizeof(sbuf),
 508                                 "500 could not translate from PASV\r\n");
 509                         write(src, sbuf, n);
 510                         return n;
 511                 }
 512 #ifdef IPV6_FAITH
 513             {
 514                 int on = 1;
 515                 error = setsockopt(wport6, IPPROTO_IPV6, IPV6_FAITH,
 516                         &on, sizeof(on));
 517                 if (error == -1)
 518                         exit_failure("setsockopt(IPV6_FAITH): %s", strerror(errno));
 519             }
 520 #endif
 521                 error = bind(wport6, (struct sockaddr *)sin6, sin6->sin6_len);
 522                 if (error == -1) {
 523                         close(wport6);
 524                         wport6 = -1;
 525                         goto passivefail;
 526                 }
 527                 error = listen(wport6, 1);
 528                 if (error == -1) {
 529                         close(wport6);
 530                         wport6 = -1;
 531                         goto passivefail;
 532                 }
 533
 534                 /* transmit LPSV or EPSV */
 535                 /*
 536                  * addr from dst, port from wport6
 537                  */
 538                 n = sizeof(data6);
 539                 error = getsockname(wport6, (struct sockaddr *)&data6, &n);
 540                 if (error == -1) {
 541                         close(wport6);
 542                         wport6 = -1;
 543                         goto passivefail;
 544                 }
 545                 sin6 = (struct sockaddr_in6 *)&data6;
 546                 port = sin6->sin6_port;
 547
 548                 n = sizeof(data6);
 549                 error = getsockname(dst, (struct sockaddr *)&data6, &n);
 550                 if (error == -1) {
 551                         close(wport6);
 552                         wport6 = -1;
 553                         goto passivefail;
 554                 }
 555                 sin6 = (struct sockaddr_in6 *)&data6;
 556                 sin6->sin6_port = port;
 557
 558                 if (state == LPSV) {
 559                         char *a, *p;
 560
 561                         a = (char *)&sin6->sin6_addr;
 562                         p = (char *)&sin6->sin6_port;
 563                         n = snprintf(sbuf, sizeof(sbuf),
 564 "228 Entering Long Passive Mode (%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d)\r\n",
 565                                 6, 16, UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
 566                                 UC(a[4]), UC(a[5]), UC(a[6]), UC(a[7]),
 567                                 UC(a[8]), UC(a[9]), UC(a[10]), UC(a[11]),
 568                                 UC(a[12]), UC(a[13]), UC(a[14]), UC(a[15]),
 569                                 2, UC(p[0]), UC(p[1]));
 570                         write(dst, sbuf, n);
 571                         passivemode = 1;
 572                         return n;
 573                 } else {
 574                         n = snprintf(sbuf, sizeof(sbuf),
 575 "229 Entering Extended Passive Mode (|||%d|)\r\n",
 576                                 ntohs(sin6->sin6_port));
 577                         write(dst, sbuf, n);
 578                         passivemode = 1;
 579                         return n;
 580                 }
 581             }
 582 #ifdef FAITH4
 583         case PASV:
 584                 /* expecting "229 Entering Extended Passive Mode (|||x|)" */
 585                 if (code != 229) {
 586 passivefail1:
 587                         close(wport6);
 588                         wport6 = -1;
 589                         write(dst, rbuf, n);
 590                         return n;
 591                 }
 592
 593             {
 594                 u_short port;
 595                 char *p;
 596                 struct sockaddr_in *sin;
 597                 struct sockaddr_in6 *sin6;
 598
 599                 /*
 600                  * EPSV result -> PORT result
 601                  */
 602                 p = param;
 603                 while (*p && *p != '(') /*)*/
 604                         p++;
 605                 if (!*p)
 606                         goto passivefail1;      /*XXX*/
 607                 p++;
 608                 n = sscanf(p, "|||%hu|", &port);
 609                 if (n != 1)
 610                         goto passivefail1;      /*XXX*/
 611
 612                 /* keep EPRT parameter */
 613                 n = sizeof(data4);
 614                 error = getpeername(src, (struct sockaddr *)&data4, &n);
 615                 if (error == -1)
 616                         goto passivefail1;      /*XXX*/
 617                 sin6 = (struct sockaddr_in6 *)&data4;
 618                 sin6->sin6_port = htons(port);
 619
 620                 /* get ready for passive data connection */
 621                 memset(&data6, 0, sizeof(data6));
 622                 sin = (struct sockaddr_in *)&data6;
 623                 sin->sin_len = sizeof(*sin);
 624                 sin->sin_family = AF_INET;
 625                 wport6 = socket(sin->sin_family, SOCK_STREAM, 0);
 626                 if (wport6 == -1) {
 627 passivefail2:
 628                         n = snprintf(sbuf, sizeof(sbuf),
 629                                 "500 could not translate from EPSV\r\n");
 630                         write(src, sbuf, n);
 631                         return n;
 632                 }
 633 #ifdef IP_FAITH
 634             {
 635                 int on = 1;
 636                 error = setsockopt(wport6, IPPROTO_IP, IP_FAITH,
 637                         &on, sizeof(on));
 638                 if (error == -1)
 639                         exit_error("setsockopt(IP_FAITH): %s", strerror(errno));
 640             }
 641 #endif
 642                 error = bind(wport6, (struct sockaddr *)sin, sin->sin_len);
 643                 if (error == -1) {
 644                         close(wport6);
 645                         wport6 = -1;
 646                         goto passivefail2;
 647                 }
 648                 error = listen(wport6, 1);
 649                 if (error == -1) {
 650                         close(wport6);
 651                         wport6 = -1;
 652                         goto passivefail2;
 653                 }
 654
 655                 /* transmit PORT */
 656                 /*
 657                  * addr from dst, port from wport6
 658                  */
 659                 n = sizeof(data6);
 660                 error = getsockname(wport6, (struct sockaddr *)&data6, &n);
 661                 if (error == -1) {
 662                         close(wport6);
 663                         wport6 = -1;
 664                         goto passivefail2;
 665                 }
 666                 sin = (struct sockaddr_in *)&data6;
 667                 port = sin->sin_port;
 668
 669                 n = sizeof(data6);
 670                 error = getsockname(dst, (struct sockaddr *)&data6, &n);
 671                 if (error == -1) {
 672                         close(wport6);
 673                         wport6 = -1;
 674                         goto passivefail2;
 675                 }
 676                 sin = (struct sockaddr_in *)&data6;
 677                 sin->sin_port = port;
 678
 679                 {
 680                         char *a, *p;
 681
 682                         a = (char *)&sin->sin_addr;
 683                         p = (char *)&sin->sin_port;
 684                         n = snprintf(sbuf, sizeof(sbuf),
 685 "227 Entering Passive Mode (%d,%d,%d,%d,%d,%d)\r\n",
 686                                 UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
 687                                 UC(p[0]), UC(p[1]));
 688                         write(dst, sbuf, n);
 689                         passivemode = 1;
 690                         return n;
 691                 }
 692             }
 693 #endif /* FAITH4 */
 694         }
 695
 696  bad:
 697         exit_failure("%s", strerror(errno));
 698         /*NOTREACHED*/
 699         return 0;       /* to make gcc happy */
 700 }
 701
 702 static int
 703 ftp_copycommand(int src, int dst, enum state *state)
 704 {
 705         int error, atmark;
 706         int n;
 707         unsigned int af, hal, ho[16], pal, po[2];
 708         char *a, *p;
 709         char cmd[5], *param;
 710         struct sockaddr_in *sin;
 711         struct sockaddr_in6 *sin6;
 712         enum state nstate;
 713         char ch;
 714
 715         /* OOB data handling */
 716         error = ioctl(src, SIOCATMARK, &atmark);
 717         if (error != -1 && atmark == 1) {
 718                 n = read(src, rbuf, 1);
 719                 if (n == -1)
 720                         goto bad;
 721                 send(dst, rbuf, n, MSG_OOB);
 722 #if 0
 723                 n = read(src, rbuf, sizeof(rbuf));
 724                 if (n == -1)
 725                         goto bad;
 726                 write(dst, rbuf, n);
 727                 return n;
 728 #endif
 729         }
 730
 731         n = read(src, rbuf, sizeof(rbuf));
 732         if (n <= 0)
 733                 return n;
 734         rbuf[n] = '\0';
 735
 736         if (n < 4) {
 737                 write(dst, rbuf, n);
 738                 return n;
 739         }
 740
 741         /*
 742          * parse argument
 743          */
 744     {
 745         char *p, *q;
 746         int i;
 747
 748         p = rbuf;
 749         q = cmd;
 750         for (i = 0; i < 4; i++) {
 751                 if (!isalpha(*p)) {
 752                         /* invalid command */
 753                         write(dst, rbuf, n);
 754                         return n;
 755                 }
 756                 *q++ = islower(*p) ? toupper(*p) : *p;
 757                 p++;
 758         }
 759         if (!isspace(*p)) {
 760                 /* invalid command */
 761                 write(dst, rbuf, n);
 762                 return n;
 763         }
 764         *q = '\0';
 765         param = p;
 766         /* param points to first non-command token, if any */
 767         while (*param && isspace(*param))
 768                 param++;
 769         if (!*param)
 770                 param = NULL;
 771     }
 772
 773         *state = NONE;
 774
 775         if (strcmp(cmd, "LPRT") == 0 && param) {
 776                 /*
 777                  * LPRT -> PORT
 778                  */
 779                 nstate = LPRT;
 780
 781                 close(wport4);
 782                 close(wport6);
 783                 close(port4);
 784                 close(port6);
 785                 wport4 = wport6 = port4 = port6 = -1;
 786
 787                 if (epsvall) {
 788                         n = snprintf(sbuf, sizeof(sbuf), "501 %s disallowed in EPSV ALL\r\n",
 789                                 cmd);
 790                         write(src, sbuf, n);
 791                         return n;
 792                 }
 793
 794                 n = sscanf(param,
 795 "%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u,%u",
 796                               &af, &hal, &ho[0], &ho[1], &ho[2], &ho[3],
 797                               &ho[4], &ho[5], &ho[6], &ho[7],
 798                               &ho[8], &ho[9], &ho[10], &ho[11],
 799                               &ho[12], &ho[13], &ho[14], &ho[15],
 800                               &pal, &po[0], &po[1]);
 801                 if (n != 21 || af != 6 || hal != 16|| pal != 2) {
 802                         n = snprintf(sbuf, sizeof(sbuf),
 803                                 "501 illegal parameter to LPRT\r\n");
 804                         write(src, sbuf, n);
 805                         return n;
 806                 }
 807
 808                 /* keep LPRT parameter */
 809                 memset(&data6, 0, sizeof(data6));
 810                 sin6 = (struct sockaddr_in6 *)&data6;
 811                 sin6->sin6_len = sizeof(*sin6);
 812                 sin6->sin6_family = AF_INET6;
 813                 for (n = 0; n < 16; n++)
 814                         sin6->sin6_addr.s6_addr[n] = ho[n];
 815                 sin6->sin6_port = htons(((po[0] & 0xff) << 8) | (po[1] & 0xff));
 816
 817 sendport:
 818                 /* get ready for active data connection */
 819                 n = sizeof(data4);
 820                 error = getsockname(dst, (struct sockaddr *)&data4, &n);
 821                 if (error == -1) {
 822 lprtfail:
 823                         n = snprintf(sbuf, sizeof(sbuf),
 824                                 "500 could not translate to PORT\r\n");
 825                         write(src, sbuf, n);
 826                         return n;
 827                 }
 828                 if (((struct sockaddr *)&data4)->sa_family != AF_INET)
 829                         goto lprtfail;
 830                 sin = (struct sockaddr_in *)&data4;
 831                 sin->sin_port = 0;
 832                 wport4 = socket(sin->sin_family, SOCK_STREAM, 0);
 833                 if (wport4 == -1)
 834                         goto lprtfail;
 835                 error = bind(wport4, (struct sockaddr *)sin, sin->sin_len);
 836                 if (error == -1) {
 837                         close(wport4);
 838                         wport4 = -1;
 839                         goto lprtfail;
 840                 }
 841                 error = listen(wport4, 1);
 842                 if (error == -1) {
 843                         close(wport4);
 844                         wport4 = -1;
 845                         goto lprtfail;
 846                 }
 847
 848                 /* transmit PORT */
 849                 n = sizeof(data4);
 850                 error = getsockname(wport4, (struct sockaddr *)&data4, &n);
 851                 if (error == -1) {
 852                         close(wport4);
 853                         wport4 = -1;
 854                         goto lprtfail;
 855                 }
 856                 if (((struct sockaddr *)&data4)->sa_family != AF_INET) {
 857                         close(wport4);
 858                         wport4 = -1;
 859                         goto lprtfail;
 860                 }
 861                 sin = (struct sockaddr_in *)&data4;
 862                 a = (char *)&sin->sin_addr;
 863                 p = (char *)&sin->sin_port;
 864                 n = snprintf(sbuf, sizeof(sbuf), "PORT %d,%d,%d,%d,%d,%d\r\n",
 865                                   UC(a[0]), UC(a[1]), UC(a[2]), UC(a[3]),
 866                                   UC(p[0]), UC(p[1]));
 867                 write(dst, sbuf, n);
 868                 *state = nstate;
 869                 passivemode = 0;
 870                 return n;
 871         } else if (strcmp(cmd, "EPRT") == 0 && param) {
 872                 /*
 873                  * EPRT -> PORT
 874                  */
 875                 char *afp, *hostp, *portp;
 876                 struct addrinfo hints, *res;
 877
 878                 nstate = EPRT;
 879
 880                 close(wport4);
 881                 close(wport6);
 882                 close(port4);
 883                 close(port6);
 884                 wport4 = wport6 = port4 = port6 = -1;
 885
 886                 if (epsvall) {
 887                         n = snprintf(sbuf, sizeof(sbuf), "501 %s disallowed in EPSV ALL\r\n",
 888                                 cmd);
 889                         write(src, sbuf, n);
 890                         return n;
 891                 }
 892
 893                 p = param;
 894                 ch = *p++;      /* boundary character */
 895                 afp = p;
 896                 while (*p && *p != ch)
 897                         p++;
 898                 if (!*p) {
 899 eprtparamfail:
 900                         n = snprintf(sbuf, sizeof(sbuf),
 901                                 "501 illegal parameter to EPRT\r\n");
 902                         write(src, sbuf, n);
 903                         return n;
 904                 }
 905                 *p++ = '\0';
 906                 hostp = p;
 907                 while (*p && *p != ch)
 908                         p++;
 909                 if (!*p)
 910                         goto eprtparamfail;
 911                 *p++ = '\0';
 912                 portp = p;
 913                 while (*p && *p != ch)
 914                         p++;
 915                 if (!*p)
 916                         goto eprtparamfail;
 917                 *p++ = '\0';
 918
 919                 n = sscanf(afp, "%d", &af);
 920                 if (n != 1 || af != 2) {
 921                         n = snprintf(sbuf, sizeof(sbuf),
 922                                 "501 unsupported address family to EPRT\r\n");
 923                         write(src, sbuf, n);
 924                         return n;
 925                 }
 926                 memset(&hints, 0, sizeof(hints));
 927                 hints.ai_family = AF_UNSPEC;
 928                 hints.ai_socktype = SOCK_STREAM;
 929                 error = getaddrinfo(hostp, portp, &hints, &res);
 930                 if (error) {
 931                         n = snprintf(sbuf, sizeof(sbuf),
 932                                 "501 EPRT: %s\r\n", gai_strerror(error));
 933                         write(src, sbuf, n);
 934                         return n;
 935                 }
 936                 if (res->ai_next) {
 937                         n = snprintf(sbuf, sizeof(sbuf),
 938                                 "501 EPRT: %s resolved to multiple addresses\r\n", hostp);
 939                         write(src, sbuf, n);
 940                         return n;
 941                 }
 942
 943                 memcpy(&data6, res->ai_addr, res->ai_addrlen);
 944
 945                 goto sendport;
 946         } else if (strcmp(cmd, "LPSV") == 0 && !param) {
 947                 /*
 948                  * LPSV -> PASV
 949                  */
 950                 nstate = LPSV;
 951
 952                 close(wport4);
 953                 close(wport6);
 954                 close(port4);
 955                 close(port6);
 956                 wport4 = wport6 = port4 = port6 = -1;
 957
 958                 if (epsvall) {
 959                         n = snprintf(sbuf, sizeof(sbuf), "501 %s disallowed in EPSV ALL\r\n",
 960                                 cmd);
 961                         write(src, sbuf, n);
 962                         return n;
 963                 }
 964
 965                 /* transmit PASV */
 966                 n = snprintf(sbuf, sizeof(sbuf), "PASV\r\n");
 967                 write(dst, sbuf, n);
 968                 *state = LPSV;
 969                 passivemode = 0;        /* to be set to 1 later */
 970                 return n;
 971         } else if (strcmp(cmd, "EPSV") == 0 && !param) {
 972                 /*
 973                  * EPSV -> PASV
 974                  */
 975                 close(wport4);
 976                 close(wport6);
 977                 close(port4);
 978                 close(port6);
 979                 wport4 = wport6 = port4 = port6 = -1;
 980
 981                 n = snprintf(sbuf, sizeof(sbuf), "PASV\r\n");
 982                 write(dst, sbuf, n);
 983                 *state = EPSV;
 984                 passivemode = 0;        /* to be set to 1 later */
 985                 return n;
 986         } else if (strcmp(cmd, "EPSV") == 0 && param
 987          && strncasecmp(param, "ALL", 3) == 0 && isspace(param[3])) {
 988                 /*
 989                  * EPSV ALL
 990                  */
 991                 epsvall = 1;
 992                 n = snprintf(sbuf, sizeof(sbuf), "200 EPSV ALL command successful.\r\n");
 993                 write(src, sbuf, n);
 994                 return n;
 995 #ifdef FAITH4
 996         } else if (strcmp(cmd, "PORT") == 0 && param) {
 997                 /*
 998                  * PORT -> EPRT
 999                  */
1000                 char host[NI_MAXHOST], serv[NI_MAXSERV];
1001
1002                 nstate = PORT;
1003
1004                 close(wport4);
1005                 close(wport6);
1006                 close(port4);
1007                 close(port6);
1008                 wport4 = wport6 = port4 = port6 = -1;
1009
1010                 p = param;
1011                 n = sscanf(p, "%u,%u,%u,%u,%u,%u",
1012                         &ho[0], &ho[1], &ho[2], &ho[3], &po[0], &po[1]);
1013                 if (n != 6) {
1014                         n = snprintf(sbuf, sizeof(sbuf),
1015                                 "501 illegal parameter to PORT\r\n");
1016                         write(src, sbuf, n);
1017                         return n;
1018                 }
1019
1020                 memset(&data6, 0, sizeof(data6));
1021                 sin = (struct sockaddr_in *)&data6;
1022                 sin->sin_len = sizeof(*sin);
1023                 sin->sin_family = AF_INET;
1024                 sin->sin_addr.s_addr = htonl(
1025                         ((ho[0] & 0xff) << 24) | ((ho[1] & 0xff) << 16) |
1026                         ((ho[2] & 0xff) << 8) | (ho[3] & 0xff));
1027                 sin->sin_port = htons(((po[0] & 0xff) << 8) | (po[1] & 0xff));
1028
1029                 /* get ready for active data connection */
1030                 n = sizeof(data4);
1031                 error = getsockname(dst, (struct sockaddr *)&data4, &n);
1032                 if (error == -1) {
1033 portfail:
1034                         n = snprintf(sbuf, sizeof(sbuf),
1035                                 "500 could not translate to EPRT\r\n");
1036                         write(src, sbuf, n);
1037                         return n;
1038                 }
1039                 if (((struct sockaddr *)&data4)->sa_family != AF_INET6)
1040                         goto portfail;
1041
1042                 ((struct sockaddr_in6 *)&data4)->sin6_port = 0;
1043                 sa = (struct sockaddr *)&data4;
1044                 wport4 = socket(sa->sa_family, SOCK_STREAM, 0);
1045                 if (wport4 == -1)
1046                         goto portfail;
1047                 error = bind(wport4, sa, sa->sa_len);
1048                 if (error == -1) {
1049                         close(wport4);
1050                         wport4 = -1;
1051                         goto portfail;
1052                 }
1053                 error = listen(wport4, 1);
1054                 if (error == -1) {
1055                         close(wport4);
1056                         wport4 = -1;
1057                         goto portfail;
1058                 }
1059
1060                 /* transmit EPRT */
1061                 n = sizeof(data4);
1062                 error = getsockname(wport4, (struct sockaddr *)&data4, &n);
1063                 if (error == -1) {
1064                         close(wport4);
1065                         wport4 = -1;
1066                         goto portfail;
1067                 }
1068                 af = 2;
1069                 sa = (struct sockaddr *)&data4;
1070                 if (getnameinfo(sa, sa->sa_len, host, sizeof(host),
1071                         serv, sizeof(serv), NI_NUMERICHOST | NI_NUMERICSERV)) {
1072                         close(wport4);
1073                         wport4 = -1;
1074                         goto portfail;
1075                 }
1076                 n = snprintf(sbuf, sizeof(sbuf), "EPRT |%d|%s|%s|\r\n", af, host, serv);
1077                 write(dst, sbuf, n);
1078                 *state = nstate;
1079                 passivemode = 0;
1080                 return n;
1081         } else if (strcmp(cmd, "PASV") == 0 && !param) {
1082                 /*
1083                  * PASV -> EPSV
1084                  */
1085
1086                 nstate = PASV;
1087
1088                 close(wport4);
1089                 close(wport6);
1090                 close(port4);
1091                 close(port6);
1092                 wport4 = wport6 = port4 = port6 = -1;
1093
1094                 /* transmit EPSV */
1095                 n = snprintf(sbuf, sizeof(sbuf), "EPSV\r\n");
1096                 write(dst, sbuf, n);
1097                 *state = PASV;
1098                 passivemode = 0;        /* to be set to 1 later */
1099                 return n;
1100 #else /* FAITH4 */
1101         } else if (strcmp(cmd, "PORT") == 0 || strcmp(cmd, "PASV") == 0) {
1102                 /*
1103                  * reject PORT/PASV
1104                  */
1105                 n = snprintf(sbuf, sizeof(sbuf), "502 %s not implemented.\r\n", cmd);
1106                 write(src, sbuf, n);
1107                 return n;
1108 #endif /* FAITH4 */
1109         } else if (passivemode
1110                 && (strcmp(cmd, "STOR") == 0
1111                  || strcmp(cmd, "STOU") == 0
1112                  || strcmp(cmd, "RETR") == 0
1113                  || strcmp(cmd, "LIST") == 0
1114                  || strcmp(cmd, "NLST") == 0
1115                  || strcmp(cmd, "APPE") == 0)) {
1116                 /*
1117                  * commands with data transfer.  need to care about passive
1118                  * mode data connection.
1119                  */
1120
1121                 if (ftp_passiveconn() < 0) {
1122                         n = snprintf(sbuf, sizeof(sbuf), "425 Cannot open data connetion\r\n");
1123                         write(src, sbuf, n);
1124                 } else {
1125                         /* simply relay the command */
1126                         write(dst, rbuf, n);
1127                 }
1128
1129                 *state = NONE;
1130                 return n;
1131         } else {
1132                 /* simply relay it */
1133                 *state = NONE;
1134                 write(dst, rbuf, n);
1135                 return n;
1136         }
1137
1138  bad:
1139         exit_failure("%s", strerror(errno));
1140         /*NOTREACHED*/
1141         return 0;       /* to make gcc happy */
1142 }