lib/libfetch/ftp.c

   1 /*-
   2  * Copyright (c) 1998 Dag-Erling Coïdan Smørgrav
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer
  10  *    in this position and unchanged.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. The name of the author may not be used to endorse or promote products
  15  *    derived from this software without specific prior written permission
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  *
  28  * $FreeBSD: src/lib/libfetch/ftp.c,v 1.16.2.31 2003/06/06 06:45:25 des Exp $
  29  * $DragonFly: src/lib/libfetch/ftp.c,v 1.3 2003/12/01 23:58:44 drhodus Exp $
  30  */
  31
  32 /*
  33  * Portions of this code were taken from or based on ftpio.c:
  34  *
  35  * ----------------------------------------------------------------------------
  36  * "THE BEER-WARE LICENSE" (Revision 42):
  37  * <phk@FreeBSD.org> wrote this file.  As long as you retain this notice you
  38  * can do whatever you want with this stuff. If we meet some day, and you think
  39  * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
  40  * ----------------------------------------------------------------------------
  41  *
  42  * Major Changelog:
  43  *
  44  * Dag-Erling Coïdan Smørgrav
  45  * 9 Jun 1998
  46  *
  47  * Incorporated into libfetch
  48  *
  49  * Jordan K. Hubbard
  50  * 17 Jan 1996
  51  *
  52  * Turned inside out. Now returns xfers as new file ids, not as a special
  53  * `state' of FTP_t
  54  *
  55  * $ftpioId: ftpio.c,v 1.30 1998/04/11 07:28:53 phk Exp $
  56  *
  57  */
  58
  59 #include <sys/param.h>
  60 #include <sys/socket.h>
  61 #include <netinet/in.h>
  62
  63 #include <ctype.h>
  64 #include <err.h>
  65 #include <errno.h>
  66 #include <fcntl.h>
  67 #include <netdb.h>
  68 #include <stdarg.h>
  69 #include <stdio.h>
  70 #include <stdlib.h>
  71 #include <string.h>
  72 #include <time.h>
  73 #include <unistd.h>
  74
  75 #include "fetch.h"
  76 #include "common.h"
  77 #include "ftperr.h"
  78
  79 #define FTP_ANONYMOUS_USER      "anonymous"
  80
  81 #define FTP_CONNECTION_ALREADY_OPEN     125
  82 #define FTP_OPEN_DATA_CONNECTION        150
  83 #define FTP_OK                          200
  84 #define FTP_FILE_STATUS                 213
  85 #define FTP_SERVICE_READY               220
  86 #define FTP_TRANSFER_COMPLETE           226
  87 #define FTP_PASSIVE_MODE                227
  88 #define FTP_LPASSIVE_MODE               228
  89 #define FTP_EPASSIVE_MODE               229
  90 #define FTP_LOGGED_IN                   230
  91 #define FTP_FILE_ACTION_OK              250
  92 #define FTP_NEED_PASSWORD               331
  93 #define FTP_NEED_ACCOUNT                332
  94 #define FTP_FILE_OK                     350
  95 #define FTP_SYNTAX_ERROR                500
  96 #define FTP_PROTOCOL_ERROR              999
  97
  98 static struct url cached_host;
  99 static conn_t   *cached_connection;
 100
 101 #define isftpreply(foo) (isdigit(foo[0]) && isdigit(foo[1]) \
 102                          && isdigit(foo[2]) \
 103                          && (foo[3] == ' ' || foo[3] == '\0'))
 104 #define isftpinfo(foo) (isdigit(foo[0]) && isdigit(foo[1]) \
 105                         && isdigit(foo[2]) && foo[3] == '-')
 106
 107 /*
 108  * Translate IPv4 mapped IPv6 address to IPv4 address
 109  */
 110 static void
 111 unmappedaddr(struct sockaddr_in6 *sin6)
 112 {
 113         struct sockaddr_in *sin4;
 114         u_int32_t addr;
 115         int port;
 116
 117         if (sin6->sin6_family != AF_INET6 ||
 118             !IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
 119                 return;
 120         sin4 = (struct sockaddr_in *)sin6;
 121         addr = *(u_int32_t *)&sin6->sin6_addr.s6_addr[12];
 122         port = sin6->sin6_port;
 123         memset(sin4, 0, sizeof(struct sockaddr_in));
 124         sin4->sin_addr.s_addr = addr;
 125         sin4->sin_port = port;
 126         sin4->sin_family = AF_INET;
 127         sin4->sin_len = sizeof(struct sockaddr_in);
 128 }
 129
 130 /*
 131  * Get server response
 132  */
 133 static int
 134 _ftp_chkerr(conn_t *conn)
 135 {
 136         if (_fetch_getln(conn) == -1) {
 137                 _fetch_syserr();
 138                 return (-1);
 139         }
 140         if (isftpinfo(conn->buf)) {
 141                 while (conn->buflen && !isftpreply(conn->buf)) {
 142                         if (_fetch_getln(conn) == -1) {
 143                                 _fetch_syserr();
 144                                 return (-1);
 145                         }
 146                 }
 147         }
 148
 149         while (conn->buflen && isspace(conn->buf[conn->buflen - 1]))
 150                 conn->buflen--;
 151         conn->buf[conn->buflen] = '\0';
 152
 153         if (!isftpreply(conn->buf)) {
 154                 _ftp_seterr(FTP_PROTOCOL_ERROR);
 155                 return (-1);
 156         }
 157
 158         conn->err = (conn->buf[0] - '0') * 100
 159             + (conn->buf[1] - '0') * 10
 160             + (conn->buf[2] - '0');
 161
 162         return (conn->err);
 163 }
 164
 165 /*
 166  * Send a command and check reply
 167  */
 168 static int
 169 _ftp_cmd(conn_t *conn, const char *fmt, ...)
 170 {
 171         va_list ap;
 172         size_t len;
 173         char *msg;
 174         int r;
 175
 176         va_start(ap, fmt);
 177         len = vasprintf(&msg, fmt, ap);
 178         va_end(ap);
 179
 180         if (msg == NULL) {
 181                 errno = ENOMEM;
 182                 _fetch_syserr();
 183                 return (-1);
 184         }
 185
 186         r = _fetch_putln(conn, msg, len);
 187         free(msg);
 188
 189         if (r == -1) {
 190                 _fetch_syserr();
 191                 return (-1);
 192         }
 193
 194         return (_ftp_chkerr(conn));
 195 }
 196
 197 /*
 198  * Return a pointer to the filename part of a path
 199  */
 200 static const char *
 201 _ftp_filename(const char *file)
 202 {
 203         char *s;
 204
 205         if ((s = strrchr(file, '/')) == NULL)
 206                 return (file);
 207         else
 208                 return (s + 1);
 209 }
 210
 211 /*
 212  * Change working directory to the directory that contains the specified
 213  * file.
 214  */
 215 static int
 216 _ftp_cwd(conn_t *conn, const char *file)
 217 {
 218         char *s;
 219         int e;
 220
 221         if ((s = strrchr(file, '/')) == NULL || s == file) {
 222                 e = _ftp_cmd(conn, "CWD /");
 223         } else {
 224                 e = _ftp_cmd(conn, "CWD %.*s", s - file, file);
 225         }
 226         if (e != FTP_FILE_ACTION_OK) {
 227                 _ftp_seterr(e);
 228                 return (-1);
 229         }
 230         return (0);
 231 }
 232
 233 /*
 234  * Request and parse file stats
 235  */
 236 static int
 237 _ftp_stat(conn_t *conn, const char *file, struct url_stat *us)
 238 {
 239         char *ln;
 240         const char *s;
 241         struct tm tm;
 242         time_t t;
 243         int e;
 244
 245         us->size = -1;
 246         us->atime = us->mtime = 0;
 247
 248         if ((s = strrchr(file, '/')) == NULL)
 249                 s = file;
 250         else
 251                 ++s;
 252
 253         if ((e = _ftp_cmd(conn, "SIZE %s", s)) != FTP_FILE_STATUS) {
 254                 _ftp_seterr(e);
 255                 return (-1);
 256         }
 257         for (ln = conn->buf + 4; *ln && isspace(*ln); ln++)
 258                 /* nothing */ ;
 259         for (us->size = 0; *ln && isdigit(*ln); ln++)
 260                 us->size = us->size * 10 + *ln - '0';
 261         if (*ln && !isspace(*ln)) {
 262                 _ftp_seterr(FTP_PROTOCOL_ERROR);
 263                 us->size = -1;
 264                 return (-1);
 265         }
 266         if (us->size == 0)
 267                 us->size = -1;
 268         DEBUG(fprintf(stderr, "size: [%lld]\n", (long long)us->size));
 269
 270         if ((e = _ftp_cmd(conn, "MDTM %s", s)) != FTP_FILE_STATUS) {
 271                 _ftp_seterr(e);
 272                 return (-1);
 273         }
 274         for (ln = conn->buf + 4; *ln && isspace(*ln); ln++)
 275                 /* nothing */ ;
 276         switch (strspn(ln, "0123456789")) {
 277         case 14:
 278                 break;
 279         case 15:
 280                 ln++;
 281                 ln[0] = '2';
 282                 ln[1] = '0';
 283                 break;
 284         default:
 285                 _ftp_seterr(FTP_PROTOCOL_ERROR);
 286                 return (-1);
 287         }
 288         if (sscanf(ln, "%04d%02d%02d%02d%02d%02d",
 289             &tm.tm_year, &tm.tm_mon, &tm.tm_mday,
 290             &tm.tm_hour, &tm.tm_min, &tm.tm_sec) != 6) {
 291                 _ftp_seterr(FTP_PROTOCOL_ERROR);
 292                 return (-1);
 293         }
 294         tm.tm_mon--;
 295         tm.tm_year -= 1900;
 296         tm.tm_isdst = -1;
 297         t = timegm(&tm);
 298         if (t == (time_t)-1)
 299                 t = time(NULL);
 300         us->mtime = t;
 301         us->atime = t;
 302         DEBUG(fprintf(stderr,
 303             "last modified: [%04d-%02d-%02d %02d:%02d:%02d]\n",
 304             tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
 305             tm.tm_hour, tm.tm_min, tm.tm_sec));
 306         return (0);
 307 }
 308
 309 /*
 310  * I/O functions for FTP
 311  */
 312 struct ftpio {
 313         conn_t  *cconn;         /* Control connection */
 314         conn_t  *dconn;         /* Data connection */
 315         int      dir;           /* Direction */
 316         int      eof;           /* EOF reached */
 317         int      err;           /* Error code */
 318 };
 319
 320 static int       _ftp_readfn(void *, char *, int);
 321 static int       _ftp_writefn(void *, const char *, int);
 322 static fpos_t    _ftp_seekfn(void *, fpos_t, int);
 323 static int       _ftp_closefn(void *);
 324
 325 static int
 326 _ftp_readfn(void *v, char *buf, int len)
 327 {
 328         struct ftpio *io;
 329         int r;
 330
 331         io = (struct ftpio *)v;
 332         if (io == NULL) {
 333                 errno = EBADF;
 334                 return (-1);
 335         }
 336         if (io->cconn == NULL || io->dconn == NULL || io->dir == O_WRONLY) {
 337                 errno = EBADF;
 338                 return (-1);
 339         }
 340         if (io->err) {
 341                 errno = io->err;
 342                 return (-1);
 343         }
 344         if (io->eof)
 345                 return (0);
 346         r = _fetch_read(io->dconn, buf, len);
 347         if (r > 0)
 348                 return (r);
 349         if (r == 0) {
 350                 io->eof = 1;
 351                 return (0);
 352         }
 353         if (errno != EINTR)
 354                 io->err = errno;
 355         return (-1);
 356 }
 357
 358 static int
 359 _ftp_writefn(void *v, const char *buf, int len)
 360 {
 361         struct ftpio *io;
 362         int w;
 363
 364         io = (struct ftpio *)v;
 365         if (io == NULL) {
 366                 errno = EBADF;
 367                 return (-1);
 368         }
 369         if (io->cconn == NULL || io->dconn == NULL || io->dir == O_RDONLY) {
 370                 errno = EBADF;
 371                 return (-1);
 372         }
 373         if (io->err) {
 374                 errno = io->err;
 375                 return (-1);
 376         }
 377         w = _fetch_write(io->dconn, buf, len);
 378         if (w >= 0)
 379                 return (w);
 380         if (errno != EINTR)
 381                 io->err = errno;
 382         return (-1);
 383 }
 384
 385 static fpos_t
 386 _ftp_seekfn(void *v, fpos_t pos __unused, int whence __unused)
 387 {
 388         struct ftpio *io;
 389
 390         io = (struct ftpio *)v;
 391         if (io == NULL) {
 392                 errno = EBADF;
 393                 return (-1);
 394         }
 395         errno = ESPIPE;
 396         return (-1);
 397 }
 398
 399 static int
 400 _ftp_closefn(void *v)
 401 {
 402         struct ftpio *io;
 403         int r;
 404
 405         io = (struct ftpio *)v;
 406         if (io == NULL) {
 407                 errno = EBADF;
 408                 return (-1);
 409         }
 410         if (io->dir == -1)
 411                 return (0);
 412         if (io->cconn == NULL || io->dconn == NULL) {
 413                 errno = EBADF;
 414                 return (-1);
 415         }
 416         _fetch_close(io->dconn);
 417         io->dir = -1;
 418         io->dconn = NULL;
 419         DEBUG(fprintf(stderr, "Waiting for final status\n"));
 420         r = _ftp_chkerr(io->cconn);
 421         if (io->cconn == cached_connection && io->cconn->ref == 1)
 422                 cached_connection = NULL;
 423         _fetch_close(io->cconn);
 424         free(io);
 425         return (r == FTP_TRANSFER_COMPLETE) ? 0 : -1;
 426 }
 427
 428 static FILE *
 429 _ftp_setup(conn_t *cconn, conn_t *dconn, int mode)
 430 {
 431         struct ftpio *io;
 432         FILE *f;
 433
 434         if (cconn == NULL || dconn == NULL)
 435                 return (NULL);
 436         if ((io = malloc(sizeof(*io))) == NULL)
 437                 return (NULL);
 438         io->cconn = cconn;
 439         io->dconn = dconn;
 440         io->dir = mode;
 441         io->eof = io->err = 0;
 442         f = funopen(io, _ftp_readfn, _ftp_writefn, _ftp_seekfn, _ftp_closefn);
 443         if (f == NULL)
 444                 free(io);
 445         return (f);
 446 }
 447
 448 /*
 449  * Transfer file
 450  */
 451 static FILE *
 452 _ftp_transfer(conn_t *conn, const char *oper, const char *file,
 453     int mode, off_t offset, const char *flags)
 454 {
 455         struct sockaddr_storage sa;
 456         struct sockaddr_in6 *sin6;
 457         struct sockaddr_in *sin4;
 458         int low, pasv, verbose;
 459         int e, sd = -1;
 460         socklen_t l;
 461         char *s;
 462         FILE *df;
 463
 464         /* check flags */
 465         low = CHECK_FLAG('l');
 466         pasv = CHECK_FLAG('p');
 467         verbose = CHECK_FLAG('v');
 468
 469         /* passive mode */
 470         if (!pasv)
 471                 pasv = ((s = getenv("FTP_PASSIVE_MODE")) != NULL &&
 472                     strncasecmp(s, "no", 2) != 0);
 473
 474         /* find our own address, bind, and listen */
 475         l = sizeof(sa);
 476         if (getsockname(conn->sd, (struct sockaddr *)&sa, &l) == -1)
 477                 goto sysouch;
 478         if (sa.ss_family == AF_INET6)
 479                 unmappedaddr((struct sockaddr_in6 *)&sa);
 480
 481         /* open data socket */
 482         if ((sd = socket(sa.ss_family, SOCK_STREAM, IPPROTO_TCP)) == -1) {
 483                 _fetch_syserr();
 484                 return (NULL);
 485         }
 486
 487         if (pasv) {
 488                 u_char addr[64];
 489                 char *ln, *p;
 490                 unsigned int i;
 491                 int port;
 492
 493                 /* send PASV command */
 494                 if (verbose)
 495                         _fetch_info("setting passive mode");
 496                 switch (sa.ss_family) {
 497                 case AF_INET:
 498                         if ((e = _ftp_cmd(conn, "PASV")) != FTP_PASSIVE_MODE)
 499                                 goto ouch;
 500                         break;
 501                 case AF_INET6:
 502                         if ((e = _ftp_cmd(conn, "EPSV")) != FTP_EPASSIVE_MODE) {
 503                                 if (e == -1)
 504                                         goto ouch;
 505                                 if ((e = _ftp_cmd(conn, "LPSV")) !=
 506                                     FTP_LPASSIVE_MODE)
 507                                         goto ouch;
 508                         }
 509                         break;
 510                 default:
 511                         e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
 512                         goto ouch;
 513                 }
 514
 515                 /*
 516                  * Find address and port number. The reply to the PASV command
 517                  * is IMHO the one and only weak point in the FTP protocol.
 518                  */
 519                 ln = conn->buf;
 520                 switch (e) {
 521                 case FTP_PASSIVE_MODE:
 522                 case FTP_LPASSIVE_MODE:
 523                         for (p = ln + 3; *p && !isdigit(*p); p++)
 524                                 /* nothing */ ;
 525                         if (!*p) {
 526                                 e = FTP_PROTOCOL_ERROR;
 527                                 goto ouch;
 528                         }
 529                         l = (e == FTP_PASSIVE_MODE ? 6 : 21);
 530                         for (i = 0; *p && i < l; i++, p++)
 531                                 addr[i] = strtol(p, &p, 10);
 532                         if (i < l) {
 533                                 e = FTP_PROTOCOL_ERROR;
 534                                 goto ouch;
 535                         }
 536                         break;
 537                 case FTP_EPASSIVE_MODE:
 538                         for (p = ln + 3; *p && *p != '('; p++)
 539                                 /* nothing */ ;
 540                         if (!*p) {
 541                                 e = FTP_PROTOCOL_ERROR;
 542                                 goto ouch;
 543                         }
 544                         ++p;
 545                         if (sscanf(p, "%c%c%c%d%c", &addr[0], &addr[1], &addr[2],
 546                                 &port, &addr[3]) != 5 ||
 547                             addr[0] != addr[1] ||
 548                             addr[0] != addr[2] || addr[0] != addr[3]) {
 549                                 e = FTP_PROTOCOL_ERROR;
 550                                 goto ouch;
 551                         }
 552                         break;
 553                 }
 554
 555                 /* seek to required offset */
 556                 if (offset)
 557                         if (_ftp_cmd(conn, "REST %lu", (u_long)offset) != FTP_FILE_OK)
 558                                 goto sysouch;
 559
 560                 /* construct sockaddr for data socket */
 561                 l = sizeof(sa);
 562                 if (getpeername(conn->sd, (struct sockaddr *)&sa, &l) == -1)
 563                         goto sysouch;
 564                 if (sa.ss_family == AF_INET6)
 565                         unmappedaddr((struct sockaddr_in6 *)&sa);
 566                 switch (sa.ss_family) {
 567                 case AF_INET6:
 568                         sin6 = (struct sockaddr_in6 *)&sa;
 569                         if (e == FTP_EPASSIVE_MODE)
 570                                 sin6->sin6_port = htons(port);
 571                         else {
 572                                 bcopy(addr + 2, (char *)&sin6->sin6_addr, 16);
 573                                 bcopy(addr + 19, (char *)&sin6->sin6_port, 2);
 574                         }
 575                         break;
 576                 case AF_INET:
 577                         sin4 = (struct sockaddr_in *)&sa;
 578                         if (e == FTP_EPASSIVE_MODE)
 579                                 sin4->sin_port = htons(port);
 580                         else {
 581                                 bcopy(addr, (char *)&sin4->sin_addr, 4);
 582                                 bcopy(addr + 4, (char *)&sin4->sin_port, 2);
 583                         }
 584                         break;
 585                 default:
 586                         e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
 587                         break;
 588                 }
 589
 590                 /* connect to data port */
 591                 if (verbose)
 592                         _fetch_info("opening data connection");
 593                 if (connect(sd, (struct sockaddr *)&sa, sa.ss_len) == -1)
 594                         goto sysouch;
 595
 596                 /* make the server initiate the transfer */
 597                 if (verbose)
 598                         _fetch_info("initiating transfer");
 599                 e = _ftp_cmd(conn, "%s %s", oper, _ftp_filename(file));
 600                 if (e != FTP_CONNECTION_ALREADY_OPEN && e != FTP_OPEN_DATA_CONNECTION)
 601                         goto ouch;
 602
 603         } else {
 604                 u_int32_t a;
 605                 u_short p;
 606                 int arg, d;
 607                 char *ap;
 608                 char hname[INET6_ADDRSTRLEN];
 609
 610                 switch (sa.ss_family) {
 611                 case AF_INET6:
 612                         ((struct sockaddr_in6 *)&sa)->sin6_port = 0;
 613 #ifdef IPV6_PORTRANGE
 614                         arg = low ? IPV6_PORTRANGE_DEFAULT : IPV6_PORTRANGE_HIGH;
 615                         if (setsockopt(sd, IPPROTO_IPV6, IPV6_PORTRANGE,
 616                                 (char *)&arg, sizeof(arg)) == -1)
 617                                 goto sysouch;
 618 #endif
 619                         break;
 620                 case AF_INET:
 621                         ((struct sockaddr_in *)&sa)->sin_port = 0;
 622                         arg = low ? IP_PORTRANGE_DEFAULT : IP_PORTRANGE_HIGH;
 623                         if (setsockopt(sd, IPPROTO_IP, IP_PORTRANGE,
 624                                 (char *)&arg, sizeof(arg)) == -1)
 625                                 goto sysouch;
 626                         break;
 627                 }
 628                 if (verbose)
 629                         _fetch_info("binding data socket");
 630                 if (bind(sd, (struct sockaddr *)&sa, sa.ss_len) == -1)
 631                         goto sysouch;
 632                 if (listen(sd, 1) == -1)
 633                         goto sysouch;
 634
 635                 /* find what port we're on and tell the server */
 636                 if (getsockname(sd, (struct sockaddr *)&sa, &l) == -1)
 637                         goto sysouch;
 638                 switch (sa.ss_family) {
 639                 case AF_INET:
 640                         sin4 = (struct sockaddr_in *)&sa;
 641                         a = ntohl(sin4->sin_addr.s_addr);
 642                         p = ntohs(sin4->sin_port);
 643                         e = _ftp_cmd(conn, "PORT %d,%d,%d,%d,%d,%d",
 644                             (a >> 24) & 0xff, (a >> 16) & 0xff,
 645                             (a >> 8) & 0xff, a & 0xff,
 646                             (p >> 8) & 0xff, p & 0xff);
 647                         break;
 648                 case AF_INET6:
 649 #define UC(b)   (((int)b)&0xff)
 650                         e = -1;
 651                         sin6 = (struct sockaddr_in6 *)&sa;
 652                         sin6->sin6_scope_id = 0;
 653                         if (getnameinfo((struct sockaddr *)&sa, sa.ss_len,
 654                                 hname, sizeof(hname),
 655                                 NULL, 0, NI_NUMERICHOST) == 0) {
 656                                 e = _ftp_cmd(conn, "EPRT |%d|%s|%d|", 2, hname,
 657                                     htons(sin6->sin6_port));
 658                                 if (e == -1)
 659                                         goto ouch;
 660                         }
 661                         if (e != FTP_OK) {
 662                                 ap = (char *)&sin6->sin6_addr;
 663                                 e = _ftp_cmd(conn,
 664                                     "LPRT %d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d",
 665                                     6, 16,
 666                                     UC(ap[0]), UC(ap[1]), UC(ap[2]), UC(ap[3]),
 667                                     UC(ap[4]), UC(ap[5]), UC(ap[6]), UC(ap[7]),
 668                                     UC(ap[8]), UC(ap[9]), UC(ap[10]), UC(ap[11]),
 669                                     UC(ap[12]), UC(ap[13]), UC(ap[14]), UC(ap[15]),
 670                                     2,
 671                                     (ntohs(sin6->sin6_port) >> 8) & 0xff,
 672                                     ntohs(sin6->sin6_port)        & 0xff);
 673                         }
 674                         break;
 675                 default:
 676                         e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
 677                         goto ouch;
 678                 }
 679                 if (e != FTP_OK)
 680                         goto ouch;
 681
 682                 /* seek to required offset */
 683                 if (offset)
 684                         if (_ftp_cmd(conn, "REST %llu",
 685                             (unsigned long long)offset) != FTP_FILE_OK)
 686                                 goto sysouch;
 687
 688                 /* make the server initiate the transfer */
 689                 if (verbose)
 690                         _fetch_info("initiating transfer");
 691                 e = _ftp_cmd(conn, "%s %s", oper, _ftp_filename(file));
 692                 if (e != FTP_OPEN_DATA_CONNECTION)
 693                         goto ouch;
 694
 695                 /* accept the incoming connection and go to town */
 696                 if ((d = accept(sd, NULL, NULL)) == -1)
 697                         goto sysouch;
 698                 close(sd);
 699                 sd = d;
 700         }
 701
 702         if ((df = _ftp_setup(conn, _fetch_reopen(sd), mode)) == NULL)
 703                 goto sysouch;
 704         return (df);
 705
 706 sysouch:
 707         _fetch_syserr();
 708         if (sd >= 0)
 709                 close(sd);
 710         return (NULL);
 711
 712 ouch:
 713         if (e != -1)
 714                 _ftp_seterr(e);
 715         if (sd >= 0)
 716                 close(sd);
 717         return (NULL);
 718 }
 719
 720 /*
 721  * Authenticate
 722  */
 723 static int
 724 _ftp_authenticate(conn_t *conn, struct url *url, struct url *purl)
 725 {
 726         const char *user, *pwd, *logname;
 727         char pbuf[MAXHOSTNAMELEN + MAXLOGNAME + 1];
 728         int e, len;
 729
 730         /* XXX FTP_AUTH, and maybe .netrc */
 731
 732         /* send user name and password */
 733         if (url->user[0] == '\0')
 734                 _fetch_netrc_auth(url);
 735         user = url->user;
 736         if (*user == '\0')
 737                 user = getenv("FTP_LOGIN");
 738         if (user == NULL || *user == '\0')
 739                 user = FTP_ANONYMOUS_USER;
 740         if (purl && url->port == _fetch_default_port(url->scheme))
 741                 e = _ftp_cmd(conn, "USER %s@%s", user, url->host);
 742         else if (purl)
 743                 e = _ftp_cmd(conn, "USER %s@%s@%d", user, url->host, url->port);
 744         else
 745                 e = _ftp_cmd(conn, "USER %s", user);
 746
 747         /* did the server request a password? */
 748         if (e == FTP_NEED_PASSWORD) {
 749                 pwd = url->pwd;
 750                 if (*pwd == '\0')
 751                         pwd = getenv("FTP_PASSWORD");
 752                 if (pwd == NULL || *pwd == '\0') {
 753                         if ((logname = getlogin()) == 0)
 754                                 logname = FTP_ANONYMOUS_USER;
 755                         if ((len = snprintf(pbuf, MAXLOGNAME + 1, "%s@", logname)) < 0)
 756                                 len = 0;
 757                         else if (len > MAXLOGNAME)
 758                                 len = MAXLOGNAME;
 759                         gethostname(pbuf + len, sizeof(pbuf) - len);
 760                         pwd = pbuf;
 761                 }
 762                 e = _ftp_cmd(conn, "PASS %s", pwd);
 763         }
 764
 765         return (e);
 766 }
 767
 768 /*
 769  * Log on to FTP server
 770  */
 771 static conn_t *
 772 _ftp_connect(struct url *url, struct url *purl, const char *flags)
 773 {
 774         conn_t *conn;
 775         int e, direct, verbose;
 776 #ifdef INET6
 777         int af = AF_UNSPEC;
 778 #else
 779         int af = AF_INET;
 780 #endif
 781
 782         direct = CHECK_FLAG('d');
 783         verbose = CHECK_FLAG('v');
 784         if (CHECK_FLAG('4'))
 785                 af = AF_INET;
 786         else if (CHECK_FLAG('6'))
 787                 af = AF_INET6;
 788
 789         if (direct)
 790                 purl = NULL;
 791
 792         /* check for proxy */
 793         if (purl) {
 794                 /* XXX proxy authentication! */
 795                 conn = _fetch_connect(purl->host, purl->port, af, verbose);
 796         } else {
 797                 /* no proxy, go straight to target */
 798                 conn = _fetch_connect(url->host, url->port, af, verbose);
 799                 purl = NULL;
 800         }
 801
 802         /* check connection */
 803         if (conn == NULL)
 804                 /* _fetch_connect() has already set an error code */
 805                 return (NULL);
 806
 807         /* expect welcome message */
 808         if ((e = _ftp_chkerr(conn)) != FTP_SERVICE_READY)
 809                 goto fouch;
 810
 811         /* authenticate */
 812         if ((e = _ftp_authenticate(conn, url, purl)) != FTP_LOGGED_IN)
 813                 goto fouch;
 814
 815         /* might as well select mode and type at once */
 816 #ifdef FTP_FORCE_STREAM_MODE
 817         if ((e = _ftp_cmd(conn, "MODE S")) != FTP_OK) /* default is S */
 818                 goto fouch;
 819 #endif
 820         if ((e = _ftp_cmd(conn, "TYPE I")) != FTP_OK) /* default is A */
 821                 goto fouch;
 822
 823         /* done */
 824         return (conn);
 825
 826 fouch:
 827         if (e != -1)
 828                 _ftp_seterr(e);
 829         _fetch_close(conn);
 830         return (NULL);
 831 }
 832
 833 /*
 834  * Disconnect from server
 835  */
 836 static void
 837 _ftp_disconnect(conn_t *conn)
 838 {
 839         (void)_ftp_cmd(conn, "QUIT");
 840         if (conn == cached_connection && conn->ref == 1)
 841                 cached_connection = NULL;
 842         _fetch_close(conn);
 843 }
 844
 845 /*
 846  * Check if we're already connected
 847  */
 848 static int
 849 _ftp_isconnected(struct url *url)
 850 {
 851         return (cached_connection
 852             && (strcmp(url->host, cached_host.host) == 0)
 853             && (strcmp(url->user, cached_host.user) == 0)
 854             && (strcmp(url->pwd, cached_host.pwd) == 0)
 855             && (url->port == cached_host.port));
 856 }
 857
 858 /*
 859  * Check the cache, reconnect if no luck
 860  */
 861 static conn_t *
 862 _ftp_cached_connect(struct url *url, struct url *purl, const char *flags)
 863 {
 864         conn_t *conn;
 865         int e;
 866
 867         /* set default port */
 868         if (!url->port)
 869                 url->port = _fetch_default_port(url->scheme);
 870
 871         /* try to use previously cached connection */
 872         if (_ftp_isconnected(url)) {
 873                 e = _ftp_cmd(cached_connection, "NOOP");
 874                 if (e == FTP_OK || e == FTP_SYNTAX_ERROR)
 875                         return (_fetch_ref(cached_connection));
 876         }
 877
 878         /* connect to server */
 879         if ((conn = _ftp_connect(url, purl, flags)) == NULL)
 880                 return (NULL);
 881         if (cached_connection)
 882                 _ftp_disconnect(cached_connection);
 883         cached_connection = _fetch_ref(conn);
 884         memcpy(&cached_host, url, sizeof(*url));
 885         return (conn);
 886 }
 887
 888 /*
 889  * Check the proxy settings
 890  */
 891 static struct url *
 892 _ftp_get_proxy(const char *flags)
 893 {
 894         struct url *purl;
 895         char *p;
 896
 897         if (flags != NULL && strchr(flags, 'd') != NULL)
 898                 return (NULL);
 899         if (((p = getenv("FTP_PROXY")) || (p = getenv("ftp_proxy")) ||
 900                 (p = getenv("HTTP_PROXY")) || (p = getenv("http_proxy"))) &&
 901             *p && (purl = fetchParseURL(p)) != NULL) {
 902                 if (!*purl->scheme) {
 903                         if (getenv("FTP_PROXY") || getenv("ftp_proxy"))
 904                                 strcpy(purl->scheme, SCHEME_FTP);
 905                         else
 906                                 strcpy(purl->scheme, SCHEME_HTTP);
 907                 }
 908                 if (!purl->port)
 909                         purl->port = _fetch_default_proxy_port(purl->scheme);
 910                 if (strcasecmp(purl->scheme, SCHEME_FTP) == 0 ||
 911                     strcasecmp(purl->scheme, SCHEME_HTTP) == 0)
 912                         return (purl);
 913                 fetchFreeURL(purl);
 914         }
 915         return (NULL);
 916 }
 917
 918 /*
 919  * Process an FTP request
 920  */
 921 FILE *
 922 _ftp_request(struct url *url, const char *op, struct url_stat *us,
 923     struct url *purl, const char *flags)
 924 {
 925         conn_t *conn;
 926         int oflag;
 927
 928         /* check if we should use HTTP instead */
 929         if (purl && strcasecmp(purl->scheme, SCHEME_HTTP) == 0) {
 930                 if (strcmp(op, "STAT") == 0)
 931                         return (_http_request(url, "HEAD", us, purl, flags));
 932                 else if (strcmp(op, "RETR") == 0)
 933                         return (_http_request(url, "GET", us, purl, flags));
 934                 /*
 935                  * Our HTTP code doesn't support PUT requests yet, so try
 936                  * a direct connection.
 937                  */
 938         }
 939
 940         /* connect to server */
 941         conn = _ftp_cached_connect(url, purl, flags);
 942         if (purl)
 943                 fetchFreeURL(purl);
 944         if (conn == NULL)
 945                 return (NULL);
 946
 947         /* change directory */
 948         if (_ftp_cwd(conn, url->doc) == -1)
 949                 return (NULL);
 950
 951         /* stat file */
 952         if (us && _ftp_stat(conn, url->doc, us) == -1
 953             && fetchLastErrCode != FETCH_PROTO
 954             && fetchLastErrCode != FETCH_UNAVAIL)
 955                 return (NULL);
 956
 957         /* just a stat */
 958         if (strcmp(op, "STAT") == 0)
 959                 return (FILE *)1; /* bogus return value */
 960         if (strcmp(op, "STOR") == 0 || strcmp(op, "APPE") == 0)
 961                 oflag = O_WRONLY;
 962         else
 963                 oflag = O_RDONLY;
 964
 965         /* initiate the transfer */
 966         return (_ftp_transfer(conn, op, url->doc, oflag, url->offset, flags));
 967 }
 968
 969 /*
 970  * Get and stat file
 971  */
 972 FILE *
 973 fetchXGetFTP(struct url *url, struct url_stat *us, const char *flags)
 974 {
 975         return (_ftp_request(url, "RETR", us, _ftp_get_proxy(flags), flags));
 976 }
 977
 978 /*
 979  * Get file
 980  */
 981 FILE *
 982 fetchGetFTP(struct url *url, const char *flags)
 983 {
 984         return (fetchXGetFTP(url, NULL, flags));
 985 }
 986
 987 /*
 988  * Put file
 989  */
 990 FILE *
 991 fetchPutFTP(struct url *url, const char *flags)
 992 {
 993
 994         return (_ftp_request(url, CHECK_FLAG('a') ? "APPE" : "STOR", NULL,
 995             _ftp_get_proxy(flags), flags));
 996 }
 997
 998 /*
 999  * Get file stats
1000  */
1001 int
1002 fetchStatFTP(struct url *url, struct url_stat *us, const char *flags)
1003 {
1004         FILE *f;
1005
1006         f = _ftp_request(url, "STAT", us, _ftp_get_proxy(flags), flags);
1007         if (f == NULL)
1008                 return (-1);
1009         return (0);
1010 }
1011
1012 /*
1013  * List a directory
1014  */
1015 struct url_ent *
1016 fetchListFTP(struct url *url __unused, const char *flags __unused)
1017 {
1018         warnx("fetchListFTP(): not implemented");
1019         return (NULL);
1020 }