lib/libfetch/ftp.c

   1 /*      $NetBSD: ftp.c,v 1.35 2010/03/21 16:48:43 joerg Exp $   */
   2 /*-
   3  * Copyright (c) 1998-2004 Dag-Erling Coïdan Smørgrav
   4  * Copyright (c) 2008, 2009, 2010 Joerg Sonnenberger <joerg@NetBSD.org>
   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  *    in this position and unchanged.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. The name of the author may not be used to endorse or promote products
  17  *    derived from this software without specific prior written permission
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  *
  30  * $FreeBSD: ftp.c,v 1.101 2008/01/23 20:57:59 des Exp $
  31  */
  32
  33 /*
  34  * Portions of this code were taken from or based on ftpio.c:
  35  *
  36  * ----------------------------------------------------------------------------
  37  * "THE BEER-WARE LICENSE" (Revision 42):
  38  * <phk@FreeBSD.org> wrote this file.  As long as you retain this notice you
  39  * can do whatever you want with this stuff. If we meet some day, and you think
  40  * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
  41  * ----------------------------------------------------------------------------
  42  *
  43  * Major Changelog:
  44  *
  45  * Dag-Erling Coïdan Smørgrav
  46  * 9 Jun 1998
  47  *
  48  * Incorporated into libfetch
  49  *
  50  * Jordan K. Hubbard
  51  * 17 Jan 1996
  52  *
  53  * Turned inside out. Now returns xfers as new file ids, not as a special
  54  * `state' of FTP_t
  55  *
  56  * $ftpioId: ftpio.c,v 1.30 1998/04/11 07:28:53 phk Exp $
  57  *
  58  */
  59
  60 #ifdef __linux__
  61 /* Keep this down to Linux, it can create surprises else where. */
  62 #define _GNU_SOURCE
  63 #endif
  64
  65 #if HAVE_CONFIG_H
  66 #include "config.h"
  67 #endif
  68 #if !defined(NETBSD) && !defined(__minix)
  69 #include <nbcompat.h>
  70 #endif
  71
  72 #include <sys/types.h>
  73 #include <sys/socket.h>
  74
  75 #include <netinet/in.h>
  76 #include <arpa/inet.h>
  77
  78 #include <ctype.h>
  79 #include <errno.h>
  80 #include <fcntl.h>
  81 #if defined(HAVE_INTTYPES_H) || defined(NETBSD)
  82 #include <inttypes.h>
  83 #endif
  84 #include <stdarg.h>
  85 #if !defined(NETBSD) && !defined(__minix)
  86 #include <nbcompat/netdb.h>
  87 #include <nbcompat/stdio.h>
  88 #else
  89 #include <netdb.h>
  90 #include <stdio.h>
  91 #endif
  92 #include <stdlib.h>
  93 #include <string.h>
  94 #include <time.h>
  95 #include <unistd.h>
  96
  97 #include "common.h"
  98 #include "ftperr.h"
  99
 100 #define FTP_ANONYMOUS_USER      "anonymous"
 101
 102 #define FTP_CONNECTION_ALREADY_OPEN     125
 103 #define FTP_OPEN_DATA_CONNECTION        150
 104 #define FTP_OK                          200
 105 #define FTP_FILE_STATUS                 213
 106 #define FTP_SERVICE_READY               220
 107 #define FTP_TRANSFER_COMPLETE           226
 108 #define FTP_PASSIVE_MODE                227
 109 #define FTP_LPASSIVE_MODE               228
 110 #define FTP_EPASSIVE_MODE               229
 111 #define FTP_LOGGED_IN                   230
 112 #define FTP_FILE_ACTION_OK              250
 113 #define FTP_DIRECTORY_CREATED           257 /* multiple meanings */
 114 #define FTP_FILE_CREATED                257 /* multiple meanings */
 115 #define FTP_WORKING_DIRECTORY           257 /* multiple meanings */
 116 #define FTP_NEED_PASSWORD               331
 117 #define FTP_NEED_ACCOUNT                332
 118 #define FTP_FILE_OK                     350
 119 #define FTP_SYNTAX_ERROR                500
 120 #define FTP_PROTOCOL_ERROR              999
 121
 122 #define isftpreply(foo)                         \
 123         (isdigit((unsigned char)foo[0]) &&      \
 124             isdigit((unsigned char)foo[1]) &&   \
 125             isdigit((unsigned char)foo[2]) &&   \
 126             (foo[3] == ' ' || foo[3] == '\0'))
 127 #define isftpinfo(foo) \
 128         (isdigit((unsigned char)foo[0]) &&      \
 129             isdigit((unsigned char)foo[1]) &&   \
 130             isdigit((unsigned char)foo[2]) &&   \
 131             foo[3] == '-')
 132
 133 #define MINBUFSIZE 4096
 134
 135 #ifdef INET6
 136 /*
 137  * Translate IPv4 mapped IPv6 address to IPv4 address
 138  */
 139 static void
 140 unmappedaddr(struct sockaddr_in6 *sin6, socklen_t *len)
 141 {
 142         struct sockaddr_in *sin4;
 143         uint32_t addr;
 144         int port;
 145
 146         if (sin6->sin6_family != AF_INET6 ||
 147             !IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
 148                 return;
 149         sin4 = (struct sockaddr_in *)sin6;
 150         addr = *(uint32_t *)&sin6->sin6_addr.s6_addr[12];
 151         port = sin6->sin6_port;
 152         memset(sin4, 0, sizeof(struct sockaddr_in));
 153         sin4->sin_addr.s_addr = addr;
 154         sin4->sin_port = port;
 155         sin4->sin_family = AF_INET;
 156         *len = sizeof(struct sockaddr_in);
 157 #ifdef HAVE_SA_LEN
 158         sin4->sin_len = sizeof(struct sockaddr_in);
 159 #endif
 160 }
 161 #endif
 162
 163 /*
 164  * Get server response
 165  */
 166 static int
 167 ftp_chkerr(conn_t *conn)
 168 {
 169         if (fetch_getln(conn) == -1) {
 170                 fetch_syserr();
 171                 return (-1);
 172         }
 173         if (isftpinfo(conn->buf)) {
 174                 while (conn->buflen && !isftpreply(conn->buf)) {
 175                         if (fetch_getln(conn) == -1) {
 176                                 fetch_syserr();
 177                                 return (-1);
 178                         }
 179                 }
 180         }
 181
 182         while (conn->buflen &&
 183             isspace((unsigned char)conn->buf[conn->buflen - 1]))
 184                 conn->buflen--;
 185         conn->buf[conn->buflen] = '\0';
 186
 187         if (!isftpreply(conn->buf)) {
 188                 ftp_seterr(FTP_PROTOCOL_ERROR);
 189                 return (-1);
 190         }
 191
 192         conn->err = (conn->buf[0] - '0') * 100
 193             + (conn->buf[1] - '0') * 10
 194             + (conn->buf[2] - '0');
 195
 196         return (conn->err);
 197 }
 198
 199 /*
 200  * Send a command and check reply
 201  */
 202 #ifndef __minix
 203 static int
 204 ftp_cmd(conn_t *conn, const char *fmt, ...)
 205 {
 206         va_list ap;
 207         size_t len;
 208         char *msg;
 209         int r;
 210
 211         va_start(ap, fmt);
 212         len = vasprintf(&msg, fmt, ap);
 213         va_end(ap);
 214
 215         if (msg == NULL) {
 216                 errno = ENOMEM;
 217                 fetch_syserr();
 218                 return (-1);
 219         }
 220
 221         r = fetch_write(conn, msg, len);
 222         free(msg);
 223
 224         if (r == -1) {
 225                 fetch_syserr();
 226                 return (-1);
 227         }
 228
 229         return (ftp_chkerr(conn));
 230 }
 231 #else
 232 static int
 233 ftp_cmd(conn_t *conn, const char *fmt, ...)
 234 {
 235         va_list ap;
 236         size_t len;
 237         char msg[MINBUFSIZE];
 238         int r;
 239
 240         va_start(ap, fmt);
 241         len = vsnprintf(&msg[0], MINBUFSIZE, fmt, ap);
 242         va_end(ap);
 243
 244         if (len >= MINBUFSIZE) {
 245                 errno = ENOMEM;
 246                 fetch_syserr();
 247                 return (-1);
 248         }
 249
 250         r = fetch_write(conn, msg, len);
 251
 252         if (r == -1) {
 253                 fetch_syserr();
 254                 return (-1);
 255         }
 256
 257         return (ftp_chkerr(conn));
 258 }
 259 #endif
 260 /*
 261  * Return a pointer to the filename part of a path
 262  */
 263 static const char *
 264 ftp_filename(const char *file, int *len, int *type, int subdir)
 265 {
 266         const char *s;
 267
 268         if ((s = strrchr(file, '/')) == NULL || subdir)
 269                 s = file;
 270         else
 271                 s = s + 1;
 272         *len = strlen(s);
 273         if (*len > 7 && strncmp(s + *len - 7, ";type=", 6) == 0) {
 274                 *type = s[*len - 1];
 275                 *len -= 7;
 276         } else {
 277                 *type = '\0';
 278         }
 279         return (s);
 280 }
 281
 282 /*
 283  * Get current working directory from the reply to a CWD, PWD or CDUP
 284  * command.
 285  */
 286 static int
 287 ftp_pwd(conn_t *conn, char **pwd)
 288 {
 289         char *src, *dst, *end;
 290         int q;
 291
 292         if (conn->err != FTP_WORKING_DIRECTORY &&
 293             conn->err != FTP_FILE_ACTION_OK)
 294                 return (FTP_PROTOCOL_ERROR);
 295         end = conn->buf + conn->buflen;
 296         src = conn->buf + 4;
 297         if (src >= end || *src++ != '"')
 298                 return (FTP_PROTOCOL_ERROR);
 299         *pwd = malloc(end - src + 1);
 300         if (*pwd == NULL)
 301                 return (FTP_PROTOCOL_ERROR);
 302         for (q = 0, dst = *pwd; src < end; ++src) {
 303                 if (!q && *src == '"')
 304                         q = 1;
 305                 else if (q && *src != '"')
 306                         break;
 307                 else if (q)
 308                         *dst++ = '"', q = 0;
 309                 else
 310                         *dst++ = *src;
 311         }
 312         *dst = '\0';
 313         if (**pwd != '/') {
 314                 free(*pwd);
 315                 *pwd = NULL;
 316                 return (FTP_PROTOCOL_ERROR);
 317         }
 318         return (FTP_OK);
 319 }
 320
 321 /*
 322  * Change working directory to the directory that contains the specified
 323  * file.
 324  */
 325 static int
 326 ftp_cwd(conn_t *conn, const char *path, int subdir)
 327 {
 328         const char *beg, *end;
 329         char *pwd, *dst;
 330         int e, i, len;
 331
 332         if (*path != '/') {
 333                 ftp_seterr(501);
 334                 return (-1);
 335         }
 336         ++path;
 337
 338         /* Simple case: still in the home directory and no directory change. */
 339         if (conn->ftp_home == NULL && strchr(path, '/') == NULL &&
 340             (!subdir || *path == '\0'))
 341                 return 0;
 342
 343         if ((e = ftp_cmd(conn, "PWD\r\n")) != FTP_WORKING_DIRECTORY ||
 344             (e = ftp_pwd(conn, &pwd)) != FTP_OK) {
 345                 ftp_seterr(e);
 346                 return (-1);
 347         }
 348         if (conn->ftp_home == NULL && (conn->ftp_home = strdup(pwd)) == NULL) {
 349                 fetch_syserr();
 350                 free(pwd);
 351                 return (-1);
 352         }
 353         if (*path == '/') {
 354                 while (path[1] == '/')
 355                         ++path;
 356                 dst = strdup(path);
 357         } else if (strcmp(conn->ftp_home, "/") == 0) {
 358                 dst = strdup(path - 1);
 359         } else {
 360 #ifndef __minix
 361                 asprintf(&dst, "%s/%s", conn->ftp_home, path);
 362 #else
 363                 if((dst = malloc(sizeof(char)*MINBUFSIZE)) != NULL) {
 364                         len = snprintf(dst, MINBUFSIZE, "%s/%s", conn->ftp_home, path);
 365
 366                         if(len >= MINBUFSIZE) {
 367                                 free(dst);
 368                                 dst = NULL;
 369                         }
 370                 }
 371 #endif
 372         }
 373         if (dst == NULL) {
 374                 fetch_syserr();
 375                 free(pwd);
 376                 return (-1);
 377         }
 378
 379         if (subdir)
 380                 end = dst + strlen(dst);
 381         else
 382                 end = strrchr(dst, '/');
 383
 384         for (;;) {
 385                 len = strlen(pwd);
 386
 387                 /* Look for a common prefix between PWD and dir to fetch. */
 388                 for (i = 0; i <= len && i <= end - dst; ++i)
 389                         if (pwd[i] != dst[i])
 390                                 break;
 391                 /* Keep going up a dir until we have a matching prefix. */
 392                 if (strcmp(pwd, "/") == 0)
 393                         break;
 394                 if (pwd[i] == '\0' && (dst[i - 1] == '/' || dst[i] == '/'))
 395                         break;
 396                 free(pwd);
 397                 if ((e = ftp_cmd(conn, "CDUP\r\n")) != FTP_FILE_ACTION_OK ||
 398                     (e = ftp_cmd(conn, "PWD\r\n")) != FTP_WORKING_DIRECTORY ||
 399                     (e = ftp_pwd(conn, &pwd)) != FTP_OK) {
 400                         ftp_seterr(e);
 401                         free(dst);
 402                         return (-1);
 403                 }
 404         }
 405         free(pwd);
 406
 407 #ifdef FTP_COMBINE_CWDS
 408         /* Skip leading slashes, even "////". */
 409         for (beg = dst + i; beg < end && *beg == '/'; ++beg, ++i)
 410                 /* nothing */ ;
 411
 412         /* If there is no trailing dir, we're already there. */
 413         if (beg >= end) {
 414                 free(dst);
 415                 return (0);
 416         }
 417
 418         /* Change to the directory all in one chunk (e.g., foo/bar/baz). */
 419         e = ftp_cmd(conn, "CWD %.*s\r\n", (int)(end - beg), beg);
 420         if (e == FTP_FILE_ACTION_OK) {
 421                 free(dst);
 422                 return (0);
 423         }
 424 #endif /* FTP_COMBINE_CWDS */
 425
 426         /* That didn't work so go back to legacy behavior (multiple CWDs). */
 427         for (beg = dst + i; beg < end; beg = dst + i + 1) {
 428                 while (*beg == '/')
 429                         ++beg, ++i;
 430                 for (++i; dst + i < end && dst[i] != '/'; ++i)
 431                         /* nothing */ ;
 432                 e = ftp_cmd(conn, "CWD %.*s\r\n", dst + i - beg, beg);
 433                 if (e != FTP_FILE_ACTION_OK) {
 434                         free(dst);
 435                         ftp_seterr(e);
 436                         return (-1);
 437                 }
 438         }
 439         free(dst);
 440         return (0);
 441 }
 442
 443 /*
 444  * Set transfer mode and data type
 445  */
 446 static int
 447 ftp_mode_type(conn_t *conn, int mode, int type)
 448 {
 449         int e;
 450
 451         switch (mode) {
 452         case 0:
 453         case 's':
 454                 mode = 'S';
 455         case 'S':
 456                 break;
 457         default:
 458                 return (FTP_PROTOCOL_ERROR);
 459         }
 460         if ((e = ftp_cmd(conn, "MODE %c\r\n", mode)) != FTP_OK) {
 461                 if (mode == 'S') {
 462                         /*
 463                          * Stream mode is supposed to be the default - so
 464                          * much so that some servers not only do not
 465                          * support any other mode, but do not support the
 466                          * MODE command at all.
 467                          *
 468                          * If "MODE S" fails, it is unlikely that we
 469                          * previously succeeded in setting a different
 470                          * mode.  Therefore, we simply hope that the
 471                          * server is already in the correct mode, and
 472                          * silently ignore the failure.
 473                          */
 474                 } else {
 475                         return (e);
 476                 }
 477         }
 478
 479         switch (type) {
 480         case 0:
 481         case 'i':
 482                 type = 'I';
 483         case 'I':
 484                 break;
 485         case 'a':
 486                 type = 'A';
 487         case 'A':
 488                 break;
 489         case 'd':
 490                 type = 'D';
 491         case 'D':
 492                 /* can't handle yet */
 493         default:
 494                 return (FTP_PROTOCOL_ERROR);
 495         }
 496         if ((e = ftp_cmd(conn, "TYPE %c\r\n", type)) != FTP_OK)
 497                 return (e);
 498
 499         return (FTP_OK);
 500 }
 501
 502 /*
 503  * Request and parse file stats
 504  */
 505 static int
 506 ftp_stat(conn_t *conn, const char *file, struct url_stat *us)
 507 {
 508         char *ln;
 509         const char *filename;
 510         int filenamelen, type;
 511         struct tm tm;
 512         time_t t;
 513         int e;
 514
 515         us->size = -1;
 516         us->atime = us->mtime = 0;
 517
 518         filename = ftp_filename(file, &filenamelen, &type, 0);
 519
 520         if ((e = ftp_mode_type(conn, 0, type)) != FTP_OK) {
 521                 ftp_seterr(e);
 522                 return (-1);
 523         }
 524
 525         e = ftp_cmd(conn, "SIZE %.*s\r\n", filenamelen, filename);
 526         if (e != FTP_FILE_STATUS) {
 527                 ftp_seterr(e);
 528                 return (-1);
 529         }
 530         for (ln = conn->buf + 4; *ln && isspace((unsigned char)*ln); ln++)
 531                 /* nothing */ ;
 532         for (us->size = 0; *ln && isdigit((unsigned char)*ln); ln++)
 533                 us->size = us->size * 10 + *ln - '0';
 534         if (*ln && !isspace((unsigned char)*ln)) {
 535                 ftp_seterr(FTP_PROTOCOL_ERROR);
 536                 us->size = -1;
 537                 return (-1);
 538         }
 539         if (us->size == 0)
 540                 us->size = -1;
 541
 542         e = ftp_cmd(conn, "MDTM %.*s\r\n", filenamelen, filename);
 543         if (e != FTP_FILE_STATUS) {
 544                 ftp_seterr(e);
 545                 return (-1);
 546         }
 547         for (ln = conn->buf + 4; *ln && isspace((unsigned char)*ln); ln++)
 548                 /* nothing */ ;
 549         switch (strspn(ln, "0123456789")) {
 550         case 14:
 551                 break;
 552         case 15:
 553                 ln++;
 554                 ln[0] = '2';
 555                 ln[1] = '0';
 556                 break;
 557         default:
 558                 ftp_seterr(FTP_PROTOCOL_ERROR);
 559                 return (-1);
 560         }
 561         if (sscanf(ln, "%04d%02d%02d%02d%02d%02d",
 562             &tm.tm_year, &tm.tm_mon, &tm.tm_mday,
 563             &tm.tm_hour, &tm.tm_min, &tm.tm_sec) != 6) {
 564                 ftp_seterr(FTP_PROTOCOL_ERROR);
 565                 return (-1);
 566         }
 567         tm.tm_mon--;
 568         tm.tm_year -= 1900;
 569         tm.tm_isdst = -1;
 570         t = timegm(&tm);
 571         if (t == (time_t)-1)
 572                 t = time(NULL);
 573         us->mtime = t;
 574         us->atime = t;
 575
 576         return (0);
 577 }
 578
 579 /*
 580  * I/O functions for FTP
 581  */
 582 struct ftpio {
 583         conn_t  *cconn;         /* Control connection */
 584         conn_t  *dconn;         /* Data connection */
 585         int      dir;           /* Direction */
 586         int      eof;           /* EOF reached */
 587         int      err;           /* Error code */
 588 };
 589
 590 static ssize_t   ftp_readfn(void *, void *, size_t);
 591 static ssize_t   ftp_writefn(void *, const void *, size_t);
 592 static void      ftp_closefn(void *);
 593
 594 static ssize_t
 595 ftp_readfn(void *v, void *buf, size_t len)
 596 {
 597         struct ftpio *io;
 598         int r;
 599
 600         io = (struct ftpio *)v;
 601         if (io == NULL) {
 602                 errno = EBADF;
 603                 return (-1);
 604         }
 605         if (io->cconn == NULL || io->dconn == NULL || io->dir == O_WRONLY) {
 606                 errno = EBADF;
 607                 return (-1);
 608         }
 609         if (io->err) {
 610                 errno = io->err;
 611                 return (-1);
 612         }
 613         if (io->eof)
 614                 return (0);
 615         r = fetch_read(io->dconn, buf, len);
 616         if (r > 0)
 617                 return (r);
 618         if (r == 0) {
 619                 io->eof = 1;
 620                 return (0);
 621         }
 622         if (errno != EINTR)
 623                 io->err = errno;
 624         return (-1);
 625 }
 626
 627 static ssize_t
 628 ftp_writefn(void *v, const void *buf, size_t len)
 629 {
 630         struct ftpio *io;
 631         int w;
 632
 633         io = (struct ftpio *)v;
 634         if (io == NULL) {
 635                 errno = EBADF;
 636                 return (-1);
 637         }
 638         if (io->cconn == NULL || io->dconn == NULL || io->dir == O_RDONLY) {
 639                 errno = EBADF;
 640                 return (-1);
 641         }
 642         if (io->err) {
 643                 errno = io->err;
 644                 return (-1);
 645         }
 646         w = fetch_write(io->dconn, buf, len);
 647         if (w >= 0)
 648                 return (w);
 649         if (errno != EINTR)
 650                 io->err = errno;
 651         return (-1);
 652 }
 653
 654 static int
 655 ftp_disconnect(conn_t *conn)
 656 {
 657         ftp_cmd(conn, "QUIT\r\n");
 658         return fetch_close(conn);
 659 }
 660
 661 static void
 662 ftp_closefn(void *v)
 663 {
 664         struct ftpio *io;
 665         int r;
 666
 667         io = (struct ftpio *)v;
 668         if (io == NULL) {
 669                 errno = EBADF;
 670                 return;
 671         }
 672         if (io->dir == -1)
 673                 return;
 674         if (io->cconn == NULL || io->dconn == NULL) {
 675                 errno = EBADF;
 676                 return;
 677         }
 678         fetch_close(io->dconn);
 679         io->dconn = NULL;
 680         io->dir = -1;
 681         r = ftp_chkerr(io->cconn);
 682         fetch_cache_put(io->cconn, ftp_disconnect);
 683         free(io);
 684         return;
 685 }
 686
 687 static fetchIO *
 688 ftp_setup(conn_t *cconn, conn_t *dconn, int mode)
 689 {
 690         struct ftpio *io;
 691         fetchIO *f;
 692
 693         if (cconn == NULL || dconn == NULL)
 694                 return (NULL);
 695         if ((io = malloc(sizeof(*io))) == NULL)
 696                 return (NULL);
 697         io->cconn = cconn;
 698         io->dconn = dconn;
 699         io->dir = mode;
 700         io->eof = io->err = 0;
 701         f = fetchIO_unopen(io, ftp_readfn, ftp_writefn, ftp_closefn);
 702         if (f == NULL)
 703                 free(io);
 704         return (f);
 705 }
 706
 707 /*
 708  * Transfer file
 709  */
 710 static fetchIO *
 711 ftp_transfer(conn_t *conn, const char *oper, const char *file, const char *op_arg,
 712     int mode, off_t offset, const char *flags)
 713 {
 714         union anonymous {
 715                 struct sockaddr_storage ss;
 716                 struct sockaddr sa;
 717                 struct sockaddr_in6 sin6;
 718                 struct sockaddr_in sin4;
 719         } u;
 720         const char *bindaddr;
 721         const char *filename;
 722         int filenamelen, type;
 723         int low, pasv, verbose;
 724         int e, sd = -1;
 725         socklen_t l;
 726         char *s;
 727         fetchIO *df;
 728
 729         /* check flags */
 730         low = CHECK_FLAG('l');
 731         pasv = !CHECK_FLAG('a');
 732         verbose = CHECK_FLAG('v');
 733
 734         /* passive mode */
 735         if (!pasv)
 736                 pasv = ((s = getenv("FTP_PASSIVE_MODE")) != NULL &&
 737                     strncasecmp(s, "no", 2) != 0);
 738
 739         /* isolate filename */
 740         filename = ftp_filename(file, &filenamelen, &type, op_arg != NULL);
 741
 742         /* set transfer mode and data type */
 743         if ((e = ftp_mode_type(conn, 0, type)) != FTP_OK)
 744                 goto ouch;
 745
 746         /* find our own address, bind, and listen */
 747         l = sizeof(u.ss);
 748         if (getsockname(conn->sd, &u.sa, &l) == -1)
 749                 goto sysouch;
 750 #ifdef INET6
 751         if (u.ss.ss_family == AF_INET6)
 752                 unmappedaddr(&u.sin6, &l);
 753 #endif
 754
 755 retry_mode:
 756
 757         /* open data socket */
 758         if ((sd = socket(u.ss.ss_family, SOCK_STREAM, IPPROTO_TCP)) == -1) {
 759                 fetch_syserr();
 760                 return (NULL);
 761         }
 762
 763         if (pasv) {
 764                 unsigned char addr[64];
 765                 char *ln, *p;
 766                 unsigned int i;
 767                 int port;
 768
 769                 /* send PASV command */
 770                 if (verbose)
 771                         fetch_info("setting passive mode");
 772                 switch (u.ss.ss_family) {
 773                 case AF_INET:
 774                         if ((e = ftp_cmd(conn, "PASV\r\n")) != FTP_PASSIVE_MODE)
 775                                 goto ouch;
 776                         break;
 777 #ifdef INET6
 778                 case AF_INET6:
 779                         if ((e = ftp_cmd(conn, "EPSV\r\n")) != FTP_EPASSIVE_MODE) {
 780                                 if (e == -1)
 781                                         goto ouch;
 782                                 if ((e = ftp_cmd(conn, "LPSV\r\n")) !=
 783                                     FTP_LPASSIVE_MODE)
 784                                         goto ouch;
 785                         }
 786                         break;
 787 #endif
 788                 default:
 789                         e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
 790                         goto ouch;
 791                 }
 792
 793                 /*
 794                  * Find address and port number. The reply to the PASV command
 795                  * is IMHO the one and only weak point in the FTP protocol.
 796                  */
 797                 ln = conn->buf;
 798                 switch (e) {
 799                 case FTP_PASSIVE_MODE:
 800                 case FTP_LPASSIVE_MODE:
 801                         for (p = ln + 3; *p && !isdigit((unsigned char)*p); p++)
 802                                 /* nothing */ ;
 803                         if (!*p) {
 804                                 e = FTP_PROTOCOL_ERROR;
 805                                 goto ouch;
 806                         }
 807                         l = (e == FTP_PASSIVE_MODE ? 6 : 21);
 808                         for (i = 0; *p && i < l; i++, p++)
 809                                 addr[i] = strtol(p, &p, 10);
 810                         if (i < l) {
 811                                 e = FTP_PROTOCOL_ERROR;
 812                                 goto ouch;
 813                         }
 814                         break;
 815                 case FTP_EPASSIVE_MODE:
 816                         for (p = ln + 3; *p && *p != '('; p++)
 817                                 /* nothing */ ;
 818                         if (!*p) {
 819                                 e = FTP_PROTOCOL_ERROR;
 820                                 goto ouch;
 821                         }
 822                         ++p;
 823                         if (sscanf(p, "%c%c%c%d%c", &addr[0], &addr[1], &addr[2],
 824                                 &port, &addr[3]) != 5 ||
 825                             addr[0] != addr[1] ||
 826                             addr[0] != addr[2] || addr[0] != addr[3]) {
 827                                 e = FTP_PROTOCOL_ERROR;
 828                                 goto ouch;
 829                         }
 830                         break;
 831                 case FTP_SYNTAX_ERROR:
 832                         if (verbose)
 833                                 fetch_info("passive mode failed");
 834                         /* Close socket and retry with passive mode. */
 835                         pasv = 0;
 836                         close(sd);
 837                         sd = -1;
 838                         goto retry_mode;
 839                 }
 840
 841                 /* seek to required offset */
 842                 if (offset)
 843                         if (ftp_cmd(conn, "REST %lu\r\n", (unsigned long)offset) != FTP_FILE_OK)
 844                                 goto sysouch;
 845
 846                 /* construct sockaddr for data socket */
 847                 l = sizeof(u.ss);
 848                 if (getpeername(conn->sd, &u.sa, &l) == -1)
 849                         goto sysouch;
 850 #ifdef INET6
 851                 if (u.ss.ss_family == AF_INET6)
 852                         unmappedaddr(&u.sin6, &l);
 853 #endif
 854                 switch (u.ss.ss_family) {
 855 #ifdef INET6
 856                 case AF_INET6:
 857                         if (e == FTP_EPASSIVE_MODE)
 858                                 u.sin6.sin6_port = htons(port);
 859                         else {
 860                                 memcpy(&u.sin6.sin6_addr, addr + 2, 16);
 861                                 memcpy(&u.sin6.sin6_port, addr + 19, 2);
 862                         }
 863                         break;
 864 #endif
 865                 case AF_INET:
 866                         if (e == FTP_EPASSIVE_MODE)
 867                                 u.sin4.sin_port = htons(port);
 868                         else {
 869                                 memcpy(&u.sin4.sin_addr, addr, 4);
 870                                 memcpy(&u.sin4.sin_port, addr + 4, 2);
 871                         }
 872                         break;
 873                 default:
 874                         e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
 875                         break;
 876                 }
 877
 878                 /* connect to data port */
 879                 if (verbose)
 880                         fetch_info("opening data connection");
 881                 bindaddr = getenv("FETCH_BIND_ADDRESS");
 882                 if (bindaddr != NULL && *bindaddr != '\0' &&
 883                     fetch_bind(sd, u.ss.ss_family, bindaddr) != 0)
 884                         goto sysouch;
 885                 if (connect(sd, &u.sa, l) == -1)
 886                         goto sysouch;
 887
 888                 /* make the server initiate the transfer */
 889                 if (verbose)
 890                         fetch_info("initiating transfer");
 891                 if (op_arg)
 892                         e = ftp_cmd(conn, "%s%s%s\r\n", oper, *op_arg ? " " : "", op_arg);
 893                 else
 894                         e = ftp_cmd(conn, "%s %.*s\r\n", oper,
 895                             filenamelen, filename);
 896                 if (e != FTP_CONNECTION_ALREADY_OPEN && e != FTP_OPEN_DATA_CONNECTION)
 897                         goto ouch;
 898
 899         } else {
 900                 uint32_t a;
 901                 uint16_t p;
 902 #if defined(IPV6_PORTRANGE) || defined(IP_PORTRANGE)
 903                 int arg;
 904 #endif
 905                 int d;
 906 #ifdef INET6
 907                 char *ap;
 908                 char hname[INET6_ADDRSTRLEN];
 909 #endif
 910
 911                 switch (u.ss.ss_family) {
 912 #ifdef INET6
 913                 case AF_INET6:
 914                         u.sin6.sin6_port = 0;
 915 #ifdef IPV6_PORTRANGE
 916                         arg = low ? IPV6_PORTRANGE_DEFAULT : IPV6_PORTRANGE_HIGH;
 917                         if (setsockopt(sd, IPPROTO_IPV6, IPV6_PORTRANGE,
 918                                 (char *)&arg, sizeof(arg)) == -1)
 919                                 goto sysouch;
 920 #endif
 921                         break;
 922 #endif
 923                 case AF_INET:
 924                         u.sin4.sin_port = 0;
 925 #ifdef IP_PORTRANGE
 926                         arg = low ? IP_PORTRANGE_DEFAULT : IP_PORTRANGE_HIGH;
 927                         if (setsockopt(sd, IPPROTO_IP, IP_PORTRANGE,
 928                                 (char *)&arg, sizeof(arg)) == -1)
 929                                 goto sysouch;
 930 #endif
 931                         break;
 932                 }
 933                 if (verbose)
 934                         fetch_info("binding data socket");
 935                 if (bind(sd, &u.sa, l) == -1)
 936                         goto sysouch;
 937                 if (listen(sd, 1) == -1)
 938                         goto sysouch;
 939
 940                 /* find what port we're on and tell the server */
 941                 if (getsockname(sd, &u.sa, &l) == -1)
 942                         goto sysouch;
 943                 switch (u.ss.ss_family) {
 944                 case AF_INET:
 945                         a = ntohl(u.sin4.sin_addr.s_addr);
 946                         p = ntohs(u.sin4.sin_port);
 947                         e = ftp_cmd(conn, "PORT %d,%d,%d,%d,%d,%d\r\n",
 948                             (a >> 24) & 0xff, (a >> 16) & 0xff,
 949                             (a >> 8) & 0xff, a & 0xff,
 950                             (p >> 8) & 0xff, p & 0xff);
 951                         break;
 952 #ifdef INET6
 953                 case AF_INET6:
 954 #define UC(b)   (((int)b)&0xff)
 955                         e = -1;
 956                         u.sin6.sin6_scope_id = 0;
 957                         if (getnameinfo(&u.sa, l,
 958                                 hname, sizeof(hname),
 959                                 NULL, 0, NI_NUMERICHOST) == 0) {
 960                                 e = ftp_cmd(conn, "EPRT |%d|%s|%d|\r\n", 2, hname,
 961                                     htons(u.sin6.sin6_port));
 962                                 if (e == -1)
 963                                         goto ouch;
 964                         }
 965                         if (e != FTP_OK) {
 966                                 ap = (char *)&u.sin6.sin6_addr;
 967                                 e = ftp_cmd(conn,
 968                                     "LPRT %d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d\r\n",
 969                                     6, 16,
 970                                     UC(ap[0]), UC(ap[1]), UC(ap[2]), UC(ap[3]),
 971                                     UC(ap[4]), UC(ap[5]), UC(ap[6]), UC(ap[7]),
 972                                     UC(ap[8]), UC(ap[9]), UC(ap[10]), UC(ap[11]),
 973                                     UC(ap[12]), UC(ap[13]), UC(ap[14]), UC(ap[15]),
 974                                     2,
 975                                     (ntohs(u.sin6.sin6_port) >> 8) & 0xff,
 976                                     ntohs(u.sin6.sin6_port)        & 0xff);
 977                         }
 978                         break;
 979 #endif
 980                 default:
 981                         e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
 982                         goto ouch;
 983                 }
 984                 if (e != FTP_OK)
 985                         goto ouch;
 986
 987 #ifndef __minix
 988                 /* seek to required offset */
 989                 if (offset)
 990                         if (ftp_cmd(conn, "REST %llu\r\n", (unsigned long long)offset) != FTP_FILE_OK)
 991                                 goto sysouch;
 992 #else
 993 /* seek to required offset */
 994                 if (offset)
 995                         if (ftp_cmd(conn, "REST %lu\r\n", (unsigned long)offset) != FTP_FILE_OK)
 996                                 goto sysouch;
 997 #endif
 998
 999                 /* make the server initiate the transfer */
1000                 if (verbose)
1001                         fetch_info("initiating transfer");
1002                 if (op_arg)
1003                         e = ftp_cmd(conn, "%s%s%s\r\n", oper, *op_arg ? " " : "", op_arg);
1004                 else
1005                         e = ftp_cmd(conn, "%s %.*s\r\n", oper,
1006                             filenamelen, filename);
1007                 if (e != FTP_CONNECTION_ALREADY_OPEN && e != FTP_OPEN_DATA_CONNECTION)
1008                         goto ouch;
1009
1010                 /* accept the incoming connection and go to town */
1011                 if ((d = accept(sd, NULL, NULL)) == -1)
1012                         goto sysouch;
1013                 close(sd);
1014                 sd = d;
1015         }
1016
1017         if ((df = ftp_setup(conn, fetch_reopen(sd), mode)) == NULL)
1018                 goto sysouch;
1019         return (df);
1020
1021 sysouch:
1022         fetch_syserr();
1023         if (sd >= 0)
1024                 close(sd);
1025         return (NULL);
1026
1027 ouch:
1028         if (e != -1)
1029                 ftp_seterr(e);
1030         if (sd >= 0)
1031                 close(sd);
1032         return (NULL);
1033 }
1034
1035 /*
1036  * Authenticate
1037  */
1038 static int
1039 ftp_authenticate(conn_t *conn, struct url *url, struct url *purl)
1040 {
1041         const char *user, *pwd, *login_name;
1042         char pbuf[URL_USERLEN + 1 + URL_HOSTLEN + 1];
1043         int e, len;
1044
1045         /* XXX FTP_AUTH, and maybe .netrc */
1046
1047         /* send user name and password */
1048         if (url->user[0] == '\0')
1049                 fetch_netrc_auth(url);
1050         user = url->user;
1051         if (*user == '\0')
1052                 user = getenv("FTP_LOGIN");
1053         if (user == NULL || *user == '\0')
1054                 user = FTP_ANONYMOUS_USER;
1055         if (purl && url->port == fetch_default_port(url->scheme))
1056                 e = ftp_cmd(conn, "USER %s@%s\r\n", user, url->host);
1057         else if (purl)
1058                 e = ftp_cmd(conn, "USER %s@%s@%d\r\n", user, url->host, url->port);
1059         else
1060                 e = ftp_cmd(conn, "USER %s\r\n", user);
1061
1062         /* did the server request a password? */
1063         if (e == FTP_NEED_PASSWORD) {
1064                 pwd = url->pwd;
1065                 if (*pwd == '\0')
1066                         pwd = getenv("FTP_PASSWORD");
1067                 if (pwd == NULL || *pwd == '\0') {
1068                         if ((login_name = getlogin()) == 0)
1069                                 login_name = FTP_ANONYMOUS_USER;
1070                         if ((len = snprintf(pbuf, URL_USERLEN + 2, "%s@", login_name)) < 0)
1071                                 len = 0;
1072                         else if (len > URL_USERLEN + 1)
1073                                 len = URL_USERLEN + 1;
1074                         gethostname(pbuf + len, sizeof(pbuf) - len);
1075                         /* MAXHOSTNAMELEN can differ from URL_HOSTLEN + 1 */
1076                         pbuf[sizeof(pbuf) - 1] = '\0';
1077                         pwd = pbuf;
1078                 }
1079                 e = ftp_cmd(conn, "PASS %s\r\n", pwd);
1080         }
1081
1082         return (e);
1083 }
1084
1085 /*
1086  * Log on to FTP server
1087  */
1088 static conn_t *
1089 ftp_connect(struct url *url, struct url *purl, const char *flags)
1090 {
1091         conn_t *conn;
1092         int e, direct, verbose;
1093 #ifdef INET6
1094         int af = AF_UNSPEC;
1095 #else
1096         int af = AF_INET;
1097 #endif
1098
1099         direct = CHECK_FLAG('d');
1100         verbose = CHECK_FLAG('v');
1101         if (CHECK_FLAG('4'))
1102                 af = AF_INET;
1103 #ifdef INET6
1104         else if (CHECK_FLAG('6'))
1105                 af = AF_INET6;
1106 #endif
1107         if (direct)
1108                 purl = NULL;
1109
1110         /* check for proxy */
1111         if (purl) {
1112                 /* XXX proxy authentication! */
1113                 /* XXX connetion caching */
1114                 if (!purl->port)
1115                         purl->port = fetch_default_port(purl->scheme);
1116
1117                 conn = fetch_connect(purl, af, verbose);
1118         } else {
1119                 /* no proxy, go straight to target */
1120                 if (!url->port)
1121                         url->port = fetch_default_port(url->scheme);
1122
1123                 while ((conn = fetch_cache_get(url, af)) != NULL) {
1124                         e = ftp_cmd(conn, "NOOP\r\n");
1125                         if (e == FTP_OK)
1126                                 return conn;
1127                         fetch_close(conn);
1128                 }
1129                 conn = fetch_connect(url, af, verbose);
1130                 purl = NULL;
1131         }
1132
1133         /* check connection */
1134         if (conn == NULL)
1135                 /* fetch_connect() has already set an error code */
1136                 return (NULL);
1137
1138         /* expect welcome message */
1139         if ((e = ftp_chkerr(conn)) != FTP_SERVICE_READY)
1140                 goto fouch;
1141
1142         /* authenticate */
1143         if ((e = ftp_authenticate(conn, url, purl)) != FTP_LOGGED_IN)
1144                 goto fouch;
1145
1146         /* TODO: Request extended features supported, if any (RFC 3659). */
1147
1148         /* done */
1149         return (conn);
1150
1151 fouch:
1152         if (e != -1)
1153                 ftp_seterr(e);
1154         fetch_close(conn);
1155         return (NULL);
1156 }
1157
1158 /*
1159  * Check the proxy settings
1160  */
1161 static struct url *
1162 ftp_get_proxy(struct url * url, const char *flags)
1163 {
1164         struct url *purl;
1165         char *p;
1166
1167         if (flags != NULL && strchr(flags, 'd') != NULL)
1168                 return (NULL);
1169         if (fetch_no_proxy_match(url->host))
1170                 return (NULL);
1171         if (((p = getenv("FTP_PROXY")) || (p = getenv("ftp_proxy")) ||
1172                 (p = getenv("HTTP_PROXY")) || (p = getenv("http_proxy"))) &&
1173             *p && (purl = fetchParseURL(p)) != NULL) {
1174                 if (!*purl->scheme) {
1175                         if (getenv("FTP_PROXY") || getenv("ftp_proxy"))
1176                                 strcpy(purl->scheme, SCHEME_FTP);
1177                         else
1178                                 strcpy(purl->scheme, SCHEME_HTTP);
1179                 }
1180                 if (!purl->port)
1181                         purl->port = fetch_default_proxy_port(purl->scheme);
1182                 if (strcasecmp(purl->scheme, SCHEME_FTP) == 0 ||
1183                     strcasecmp(purl->scheme, SCHEME_HTTP) == 0)
1184                         return (purl);
1185                 fetchFreeURL(purl);
1186         }
1187         return (NULL);
1188 }
1189
1190 /*
1191  * Process an FTP request
1192  */
1193 fetchIO *
1194 ftp_request(struct url *url, const char *op, const char *op_arg,
1195     struct url_stat *us, struct url *purl, const char *flags)
1196 {
1197         fetchIO *f;
1198         char *path;
1199         conn_t *conn;
1200         int if_modified_since, oflag;
1201         struct url_stat local_us;
1202
1203         /* check if we should use HTTP instead */
1204         if (purl && strcasecmp(purl->scheme, SCHEME_HTTP) == 0) {
1205                 if (strcmp(op, "STAT") == 0)
1206                         return (http_request(url, "HEAD", us, purl, flags));
1207                 else if (strcmp(op, "RETR") == 0)
1208                         return (http_request(url, "GET", us, purl, flags));
1209                 /*
1210                  * Our HTTP code doesn't support PUT requests yet, so try
1211                  * a direct connection.
1212                  */
1213         }
1214
1215         /* connect to server */
1216         conn = ftp_connect(url, purl, flags);
1217         if (purl)
1218                 fetchFreeURL(purl);
1219         if (conn == NULL)
1220                 return (NULL);
1221
1222         if ((path = fetchUnquotePath(url)) == NULL) {
1223                 fetch_syserr();
1224                 return NULL;
1225         }
1226
1227         /* change directory */
1228         if (ftp_cwd(conn, path, op_arg != NULL) == -1) {
1229                 free(path);
1230                 return (NULL);
1231         }
1232
1233         if_modified_since = CHECK_FLAG('i');
1234         if (if_modified_since && us == NULL)
1235                 us = &local_us;
1236
1237         /* stat file */
1238         if (us && ftp_stat(conn, path, us) == -1
1239             && fetchLastErrCode != FETCH_PROTO
1240             && fetchLastErrCode != FETCH_UNAVAIL) {
1241                 free(path);
1242                 return (NULL);
1243         }
1244
1245         if (if_modified_since && url->last_modified > 0 &&
1246             url->last_modified >= us->mtime) {
1247                 free(path);
1248                 fetchLastErrCode = FETCH_UNCHANGED;
1249                 snprintf(fetchLastErrString, MAXERRSTRING, "Unchanged");
1250                 return NULL;
1251         }
1252
1253         /* just a stat */
1254         if (strcmp(op, "STAT") == 0) {
1255                 free(path);
1256                 return fetchIO_unopen(NULL, NULL, NULL, NULL);
1257         }
1258         if (strcmp(op, "STOR") == 0 || strcmp(op, "APPE") == 0)
1259                 oflag = O_WRONLY;
1260         else
1261                 oflag = O_RDONLY;
1262
1263         /* initiate the transfer */
1264         f = (ftp_transfer(conn, op, path, op_arg, oflag, url->offset, flags));
1265         free(path);
1266         return f;
1267 }
1268
1269 /*
1270  * Get and stat file
1271  */
1272 fetchIO *
1273 fetchXGetFTP(struct url *url, struct url_stat *us, const char *flags)
1274 {
1275         return (ftp_request(url, "RETR", NULL, us, ftp_get_proxy(url, flags), flags));
1276 }
1277
1278 /*
1279  * Get file
1280  */
1281 fetchIO *
1282 fetchGetFTP(struct url *url, const char *flags)
1283 {
1284         return (fetchXGetFTP(url, NULL, flags));
1285 }
1286
1287 /*
1288  * Put file
1289  */
1290 fetchIO *
1291 fetchPutFTP(struct url *url, const char *flags)
1292 {
1293         return (ftp_request(url, CHECK_FLAG('a') ? "APPE" : "STOR", NULL, NULL,
1294             ftp_get_proxy(url, flags), flags));
1295 }
1296
1297 /*
1298  * Get file stats
1299  */
1300 int
1301 fetchStatFTP(struct url *url, struct url_stat *us, const char *flags)
1302 {
1303         fetchIO *f;
1304
1305         f = ftp_request(url, "STAT", NULL, us, ftp_get_proxy(url, flags), flags);
1306         if (f == NULL)
1307                 return (-1);
1308         fetchIO_close(f);
1309         return (0);
1310 }
1311
1312 /*
1313  * List a directory
1314  */
1315 int
1316 fetchListFTP(struct url_list *ue, struct url *url, const char *pattern, const char *flags)
1317 {
1318         fetchIO *f;
1319         char buf[2 * PATH_MAX], *eol, *eos;
1320         ssize_t len;
1321         size_t cur_off;
1322         int ret;
1323
1324         /* XXX What about proxies? */
1325         if (pattern == NULL || strcmp(pattern, "*") == 0)
1326                 pattern = "";
1327         f = ftp_request(url, "NLST", pattern, NULL, ftp_get_proxy(url, flags), flags);
1328         if (f == NULL)
1329                 return -1;
1330
1331         cur_off = 0;
1332         ret = 0;
1333
1334         while ((len = fetchIO_read(f, buf + cur_off, sizeof(buf) - cur_off)) > 0) {
1335                 cur_off += len;
1336                 while ((eol = memchr(buf, '\n', cur_off)) != NULL) {
1337                         if (len == eol - buf)
1338                                 break;
1339                         if (eol != buf) {
1340                                 if (eol[-1] == '\r')
1341                                         eos = eol - 1;
1342                                 else
1343                                         eos = eol;
1344                                 *eos = '\0';
1345                                 ret = fetch_add_entry(ue, url, buf, 0);
1346                                 if (ret)
1347                                         break;
1348                                 cur_off -= eol - buf + 1;
1349                                 memmove(buf, eol + 1, cur_off);
1350                         }
1351                 }
1352                 if (ret)
1353                         break;
1354         }
1355         if (cur_off != 0 || len < 0) {
1356                 /* Not RFC conform, bail out. */
1357                 fetchIO_close(f);
1358                 return -1;
1359         }
1360         fetchIO_close(f);
1361         return ret;
1362 }