external/bsd/fetch/dist/libfetch/ftp.c

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