share/examples/refuse/ian/libfetch/ftp.c

   1 /*-
   2  * Copyright (c) 1998-2004 Dag-Erling Coïdan Smørgrav
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer
  10  *    in this position and unchanged.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. The name of the author may not be used to endorse or promote products
  15  *    derived from this software without specific prior written permission
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #include "free2net.h"
  30
  31 #include <sys/cdefs.h>
  32 __FBSDID("$FreeBSD: src/lib/libfetch/ftp.c,v 1.91.2.2 2007/05/16 07:04:02 njl Exp $");
  33
  34 /*
  35  * Portions of this code were taken from or based on ftpio.c:
  36  *
  37  * ----------------------------------------------------------------------------
  38  * "THE BEER-WARE LICENSE" (Revision 42):
  39  * <phk@FreeBSD.org> wrote this file.  As long as you retain this notice you
  40  * can do whatever you want with this stuff. If we meet some day, and you think
  41  * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
  42  * ----------------------------------------------------------------------------
  43  *
  44  * Major Changelog:
  45  *
  46  * Dag-Erling Coïdan Smørgrav
  47  * 9 Jun 1998
  48  *
  49  * Incorporated into libfetch
  50  *
  51  * Jordan K. Hubbard
  52  * 17 Jan 1996
  53  *
  54  * Turned inside out. Now returns xfers as new file ids, not as a special
  55  * `state' of FTP_t
  56  *
  57  * $ftpioId: ftpio.c,v 1.30 1998/04/11 07:28:53 phk Exp $
  58  *
  59  */
  60
  61 #include <sys/param.h>
  62 #include <sys/socket.h>
  63 #include <netinet/in.h>
  64
  65 #include <ctype.h>
  66 #include <err.h>
  67 #include <errno.h>
  68 #include <fcntl.h>
  69 #include <netdb.h>
  70 #include <stdarg.h>
  71 #include <stdint.h>
  72 #include <stdio.h>
  73 #include <stdlib.h>
  74 #include <string.h>
  75 #include <time.h>
  76 #include <unistd.h>
  77
  78 #include "fetch.h"
  79 #include "common.h"
  80 #include "ftperr.h"
  81
  82 #define FTP_ANONYMOUS_USER      "anonymous"
  83
  84 #define FTP_CONNECTION_ALREADY_OPEN     125
  85 #define FTP_OPEN_DATA_CONNECTION        150
  86 #define FTP_OK                          200
  87 #define FTP_FILE_STATUS                 213
  88 #define FTP_SERVICE_READY               220
  89 #define FTP_TRANSFER_COMPLETE           226
  90 #define FTP_PASSIVE_MODE                227
  91 #define FTP_LPASSIVE_MODE               228
  92 #define FTP_EPASSIVE_MODE               229
  93 #define FTP_LOGGED_IN                   230
  94 #define FTP_FILE_ACTION_OK              250
  95 #define FTP_DIRECTORY_CREATED           257 /* multiple meanings */
  96 #define FTP_FILE_CREATED                257 /* multiple meanings */
  97 #define FTP_WORKING_DIRECTORY           257 /* multiple meanings */
  98 #define FTP_NEED_PASSWORD               331
  99 #define FTP_NEED_ACCOUNT                332
 100 #define FTP_FILE_OK                     350
 101 #define FTP_SYNTAX_ERROR                500
 102 #define FTP_PROTOCOL_ERROR              999
 103
 104 static struct url cached_host;
 105 static conn_t   *cached_connection;
 106
 107 #define isftpreply(foo) (isdigit((unsigned)foo[0]) && \
 108                          isdigit((unsigned)foo[1]) && \
 109                          isdigit((unsigned)foo[2]) && \
 110                          (foo[3] == ' ' || foo[3] == '\0'))
 111 #define isftpinfo(foo) (isdigit((unsigned)foo[0]) && \
 112                          isdigit((unsigned)foo[1]) && \
 113                          isdigit((unsigned)foo[2]) && foo[3] == '-')
 114
 115 /*
 116  * Translate IPv4 mapped IPv6 address to IPv4 address
 117  */
 118 static void
 119 unmappedaddr(struct sockaddr_in6 *sin6)
 120 {
 121         struct sockaddr_in *sin4;
 122         u_int32_t addr;
 123         int port;
 124
 125         if (sin6->sin6_family != AF_INET6 ||
 126             !IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
 127                 return;
 128         sin4 = (struct sockaddr_in *)(void *)sin6;
 129         addr = *(u_int32_t *)(void *)&sin6->sin6_addr.s6_addr[12];
 130         port = sin6->sin6_port;
 131         memset(sin4, 0, sizeof(struct sockaddr_in));
 132         sin4->sin_addr.s_addr = addr;
 133         sin4->sin_port = port;
 134         sin4->sin_family = AF_INET;
 135         sin4->sin_len = sizeof(struct sockaddr_in);
 136 }
 137
 138 /*
 139  * Get server response
 140  */
 141 static int
 142 _ftp_chkerr(conn_t *conn)
 143 {
 144         if (_fetch_getln(conn) == -1) {
 145                 _fetch_syserr();
 146                 return (-1);
 147         }
 148         if (isftpinfo(conn->buf)) {
 149                 while (conn->buflen && !isftpreply(conn->buf)) {
 150                         if (_fetch_getln(conn) == -1) {
 151                                 _fetch_syserr();
 152                                 return (-1);
 153                         }
 154                 }
 155         }
 156
 157         while (conn->buflen && isspace((unsigned)conn->buf[conn->buflen - 1]))
 158                 conn->buflen--;
 159         conn->buf[conn->buflen] = '\0';
 160
 161         if (!isftpreply(conn->buf)) {
 162                 _ftp_seterr(FTP_PROTOCOL_ERROR);
 163                 return (-1);
 164         }
 165
 166         conn->err = (conn->buf[0] - '0') * 100
 167             + (conn->buf[1] - '0') * 10
 168             + (conn->buf[2] - '0');
 169
 170         return (conn->err);
 171 }
 172
 173 /*
 174  * Send a command and check reply
 175  */
 176 static int
 177 _ftp_cmd(conn_t *conn, const char *fmt, ...)
 178 {
 179         va_list ap;
 180         size_t len;
 181         char *msg;
 182         int r;
 183
 184         va_start(ap, fmt);
 185         len = vasprintf(&msg, fmt, ap);
 186         va_end(ap);
 187
 188         if (msg == NULL) {
 189                 errno = ENOMEM;
 190                 _fetch_syserr();
 191                 return (-1);
 192         }
 193
 194         r = _fetch_putln(conn, msg, len);
 195         free(msg);
 196
 197         if (r == -1) {
 198                 _fetch_syserr();
 199                 return (-1);
 200         }
 201
 202         return (_ftp_chkerr(conn));
 203 }
 204
 205 /*
 206  * Return a pointer to the filename part of a path
 207  */
 208 static const char *
 209 _ftp_filename(const char *file, int *len, int *type)
 210 {
 211         const char *s;
 212
 213         if ((s = strrchr(file, '/')) == NULL)
 214                 s = file;
 215         else
 216                 s = s + 1;
 217         *len = strlen(s);
 218         if (*len > 7 && strncmp(s + *len - 7, ";type=", 6) == 0) {
 219                 *type = s[*len - 1];
 220                 *len -= 7;
 221         } else {
 222                 *type = '\0';
 223         }
 224         return (s);
 225 }
 226
 227 /*
 228  * Get current working directory from the reply to a CWD, PWD or CDUP
 229  * command.
 230  */
 231 static int
 232 _ftp_pwd(conn_t *conn, char *pwd, size_t pwdlen)
 233 {
 234         char *src, *dst, *end;
 235         int q;
 236
 237         if (conn->err != FTP_WORKING_DIRECTORY &&
 238             conn->err != FTP_FILE_ACTION_OK)
 239                 return (FTP_PROTOCOL_ERROR);
 240         end = conn->buf + conn->buflen;
 241         src = conn->buf + 4;
 242         if (src >= end || *src++ != '"')
 243                 return (FTP_PROTOCOL_ERROR);
 244         for (q = 0, dst = pwd; src < end && pwdlen--; ++src) {
 245                 if (!q && *src == '"')
 246                         q = 1;
 247                 else if (q && *src != '"')
 248                         break;
 249                 else if (q)
 250                         *dst++ = '"', q = 0;
 251                 else
 252                         *dst++ = *src;
 253         }
 254         if (!pwdlen)
 255                 return (FTP_PROTOCOL_ERROR);
 256         *dst = '\0';
 257 #if 0
 258         DEBUG(fprintf(stderr, "pwd: [%s]\n", pwd));
 259 #endif
 260         return (FTP_OK);
 261 }
 262
 263 /*
 264  * Change working directory to the directory that contains the specified
 265  * file.
 266  */
 267 static int
 268 _ftp_cwd(conn_t *conn, const char *file)
 269 {
 270         const char *beg, *end;
 271         char pwd[PATH_MAX];
 272         int e, i, len;
 273
 274         /* If no slashes in name, no need to change dirs. */
 275         if ((end = strrchr(file, '/')) == NULL)
 276                 return (0);
 277         if ((e = _ftp_cmd(conn, "PWD")) != FTP_WORKING_DIRECTORY ||
 278             (e = _ftp_pwd(conn, pwd, sizeof(pwd))) != FTP_OK) {
 279                 _ftp_seterr(e);
 280                 return (-1);
 281         }
 282         for (;;) {
 283                 len = strlen(pwd);
 284
 285                 /* Look for a common prefix between PWD and dir to fetch. */
 286                 for (i = 0; i <= len && i <= end - file; ++i)
 287                         if (pwd[i] != file[i])
 288                                 break;
 289 #if 0
 290                 DEBUG(fprintf(stderr, "have: [%.*s|%s]\n", i, pwd, pwd + i));
 291                 DEBUG(fprintf(stderr, "want: [%.*s|%s]\n", i, file, file + i));
 292 #endif
 293                 /* Keep going up a dir until we have a matching prefix. */
 294                 if (pwd[i] == '\0' && (file[i - 1] == '/' || file[i] == '/'))
 295                         break;
 296                 if ((e = _ftp_cmd(conn, "CDUP")) != FTP_FILE_ACTION_OK ||
 297                     (e = _ftp_cmd(conn, "PWD")) != FTP_WORKING_DIRECTORY ||
 298                     (e = _ftp_pwd(conn, pwd, sizeof(pwd))) != FTP_OK) {
 299                         _ftp_seterr(e);
 300                         return (-1);
 301                 }
 302         }
 303
 304 #ifdef FTP_COMBINE_CWDS
 305         /* Skip leading slashes, even "////". */
 306         for (beg = file + i; beg < end && *beg == '/'; ++beg, ++i)
 307                 /* nothing */ ;
 308
 309         /* If there is no trailing dir, we're already there. */
 310         if (beg >= end)
 311                 return (0);
 312
 313         /* Change to the directory all in one chunk (e.g., foo/bar/baz). */
 314         e = _ftp_cmd(conn, "CWD %.*s", (int)(end - beg), beg);
 315         if (e == FTP_FILE_ACTION_OK)
 316                 return (0);
 317 #endif /* FTP_COMBINE_CWDS */
 318
 319         /* That didn't work so go back to legacy behavior (multiple CWDs). */
 320         for (beg = file + i; beg < end; beg = file + i + 1) {
 321                 while (*beg == '/')
 322                         ++beg, ++i;
 323                 for (++i; file + i < end && file[i] != '/'; ++i)
 324                         /* nothing */ ;
 325                 e = _ftp_cmd(conn, "CWD %.*s", file + i - beg, beg);
 326                 if (e != FTP_FILE_ACTION_OK) {
 327                         _ftp_seterr(e);
 328                         return (-1);
 329                 }
 330         }
 331         return (0);
 332 }
 333
 334 /*
 335  * Set transfer mode and data type
 336  */
 337 static int
 338 _ftp_mode_type(conn_t *conn, int mode, int type)
 339 {
 340         int e;
 341
 342         switch (mode) {
 343         case 0:
 344         case 's':
 345                 mode = 'S';
 346                 /* FALLTHROUGH */
 347         case 'S':
 348                 break;
 349         default:
 350                 return (FTP_PROTOCOL_ERROR);
 351         }
 352         if ((e = _ftp_cmd(conn, "MODE %c", mode)) != FTP_OK) {
 353                 if (mode == 'S') {
 354                         /*
 355                          * Stream mode is supposed to be the default - so
 356                          * much so that some servers not only do not
 357                          * support any other mode, but do not support the
 358                          * MODE command at all.
 359                          *
 360                          * If "MODE S" fails, it is unlikely that we
 361                          * previously succeeded in setting a different
 362                          * mode.  Therefore, we simply hope that the
 363                          * server is already in the correct mode, and
 364                          * silently ignore the failure.
 365                          */
 366                 } else {
 367                         return (e);
 368                 }
 369         }
 370
 371         switch (type) {
 372         case 0:
 373         case 'i':
 374                 type = 'I';
 375                 /* FALLTHROUGH */
 376         case 'I':
 377                 break;
 378         case 'a':
 379                 type = 'A';
 380                 /* FALLTHROUGH */
 381         case 'A':
 382                 break;
 383         case 'd':
 384                 type = 'D';
 385                 /* FALLTHROUGH */
 386         case 'D':
 387                 /* can't handle yet */
 388         default:
 389                 return (FTP_PROTOCOL_ERROR);
 390         }
 391         if ((e = _ftp_cmd(conn, "TYPE %c", type)) != FTP_OK)
 392                 return (e);
 393
 394         return (FTP_OK);
 395 }
 396
 397 /*
 398  * Request and parse file stats
 399  */
 400 static int
 401 _ftp_stat(conn_t *conn, const char *file, struct url_stat *us)
 402 {
 403         char *ln;
 404         const char *filename;
 405         int filenamelen, type;
 406         struct tm tm;
 407         time_t t;
 408         int e;
 409
 410         us->size = -1;
 411         us->atime = us->mtime = 0;
 412
 413         filename = _ftp_filename(file, &filenamelen, &type);
 414
 415         if ((e = _ftp_mode_type(conn, 0, type)) != FTP_OK) {
 416                 _ftp_seterr(e);
 417                 return (-1);
 418         }
 419
 420         e = _ftp_cmd(conn, "SIZE %.*s", filenamelen, filename);
 421         if (e != FTP_FILE_STATUS) {
 422                 _ftp_seterr(e);
 423                 return (-1);
 424         }
 425         for (ln = conn->buf + 4; *ln && isspace((unsigned)*ln); ln++)
 426                 /* nothing */ ;
 427         for (us->size = 0; *ln && isdigit((unsigned)*ln); ln++)
 428                 us->size = us->size * 10 + *ln - '0';
 429         if (*ln && !isspace((unsigned)*ln)) {
 430                 _ftp_seterr(FTP_PROTOCOL_ERROR);
 431                 us->size = -1;
 432                 return (-1);
 433         }
 434         if (us->size == 0)
 435                 us->size = -1;
 436         DEBUG(fprintf(stderr, "size: [%lld]\n", (long long)us->size));
 437
 438         e = _ftp_cmd(conn, "MDTM %.*s", filenamelen, filename);
 439         if (e != FTP_FILE_STATUS) {
 440                 _ftp_seterr(e);
 441                 return (-1);
 442         }
 443         for (ln = conn->buf + 4; *ln && isspace((unsigned)*ln); ln++)
 444                 /* nothing */ ;
 445         switch (strspn(ln, "0123456789")) {
 446         case 14:
 447                 break;
 448         case 15:
 449                 ln++;
 450                 ln[0] = '2';
 451                 ln[1] = '0';
 452                 break;
 453         default:
 454                 _ftp_seterr(FTP_PROTOCOL_ERROR);
 455                 return (-1);
 456         }
 457         if (sscanf(ln, "%04d%02d%02d%02d%02d%02d",
 458             &tm.tm_year, &tm.tm_mon, &tm.tm_mday,
 459             &tm.tm_hour, &tm.tm_min, &tm.tm_sec) != 6) {
 460                 _ftp_seterr(FTP_PROTOCOL_ERROR);
 461                 return (-1);
 462         }
 463         tm.tm_mon--;
 464         tm.tm_year -= 1900;
 465         tm.tm_isdst = -1;
 466         t = timegm(&tm);
 467         if (t == (time_t)-1)
 468                 t = time(NULL);
 469         us->mtime = t;
 470         us->atime = t;
 471         DEBUG(fprintf(stderr,
 472             "last modified: [%04d-%02d-%02d %02d:%02d:%02d]\n",
 473             tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
 474             tm.tm_hour, tm.tm_min, tm.tm_sec));
 475         return (0);
 476 }
 477
 478 /*
 479  * I/O functions for FTP
 480  */
 481 struct ftpio {
 482         conn_t  *cconn;         /* Control connection */
 483         conn_t  *dconn;         /* Data connection */
 484         int      dir;           /* Direction */
 485         int      eof;           /* EOF reached */
 486         int      err;           /* Error code */
 487 };
 488
 489 static int       _ftp_readfn(void *, char *, int);
 490 static int       _ftp_writefn(void *, const char *, int);
 491 static fpos_t    _ftp_seekfn(void *, fpos_t, int);
 492 static int       _ftp_closefn(void *);
 493
 494 static int
 495 _ftp_readfn(void *v, char *buf, int len)
 496 {
 497         struct ftpio *io;
 498         int r;
 499
 500         io = (struct ftpio *)v;
 501         if (io == NULL) {
 502                 errno = EBADF;
 503                 return (-1);
 504         }
 505         if (io->cconn == NULL || io->dconn == NULL || io->dir == O_WRONLY) {
 506                 errno = EBADF;
 507                 return (-1);
 508         }
 509         if (io->err) {
 510                 errno = io->err;
 511                 return (-1);
 512         }
 513         if (io->eof)
 514                 return (0);
 515         r = _fetch_read(io->dconn, buf, (unsigned)len);
 516         if (r > 0)
 517                 return (r);
 518         if (r == 0) {
 519                 io->eof = 1;
 520                 return (0);
 521         }
 522         if (errno != EINTR)
 523                 io->err = errno;
 524         return (-1);
 525 }
 526
 527 static int
 528 _ftp_writefn(void *v, const char *buf, int len)
 529 {
 530         struct ftpio *io;
 531         int w;
 532
 533         io = (struct ftpio *)v;
 534         if (io == NULL) {
 535                 errno = EBADF;
 536                 return (-1);
 537         }
 538         if (io->cconn == NULL || io->dconn == NULL || io->dir == O_RDONLY) {
 539                 errno = EBADF;
 540                 return (-1);
 541         }
 542         if (io->err) {
 543                 errno = io->err;
 544                 return (-1);
 545         }
 546         w = _fetch_write(io->dconn, buf, (unsigned)len);
 547         if (w >= 0)
 548                 return (w);
 549         if (errno != EINTR)
 550                 io->err = errno;
 551         return (-1);
 552 }
 553
 554 /* ARGSUSED1 */
 555 static fpos_t
 556 _ftp_seekfn(void *v, fpos_t pos __unused, int whence __unused)
 557 {
 558         struct ftpio *io;
 559
 560         io = (struct ftpio *)v;
 561         if (io == NULL) {
 562                 errno = EBADF;
 563                 return (-1);
 564         }
 565         errno = ESPIPE;
 566         return (-1);
 567 }
 568
 569 static int
 570 _ftp_closefn(void *v)
 571 {
 572         struct ftpio *io;
 573         int r;
 574
 575         io = (struct ftpio *)v;
 576         if (io == NULL) {
 577                 errno = EBADF;
 578                 return (-1);
 579         }
 580         if (io->dir == -1)
 581                 return (0);
 582         if (io->cconn == NULL || io->dconn == NULL) {
 583                 errno = EBADF;
 584                 return (-1);
 585         }
 586         _fetch_close(io->dconn);
 587         io->dir = -1;
 588         io->dconn = NULL;
 589         DEBUG(fprintf(stderr, "Waiting for final status\n"));
 590         r = _ftp_chkerr(io->cconn);
 591         if (io->cconn == cached_connection && io->cconn->ref == 1)
 592                 cached_connection = NULL;
 593         _fetch_close(io->cconn);
 594         free(io);
 595         return (r == FTP_TRANSFER_COMPLETE) ? 0 : -1;
 596 }
 597
 598 static FILE *
 599 _ftp_setup(conn_t *cconn, conn_t *dconn, int mode)
 600 {
 601         struct ftpio *io;
 602         FILE *f;
 603
 604         if (cconn == NULL || dconn == NULL)
 605                 return (NULL);
 606         if ((io = malloc(sizeof(*io))) == NULL)
 607                 return (NULL);
 608         io->cconn = cconn;
 609         io->dconn = dconn;
 610         io->dir = mode;
 611         io->eof = io->err = 0;
 612         f = funopen(io, _ftp_readfn, _ftp_writefn, _ftp_seekfn, _ftp_closefn);
 613         if (f == NULL)
 614                 free(io);
 615         return (f);
 616 }
 617
 618 /*
 619  * Transfer file
 620  */
 621 static FILE *
 622 _ftp_transfer(conn_t *conn, const char *oper, const char *file,
 623     int mode, off_t offset, const char *flags)
 624 {
 625         struct sockaddr_storage sa;
 626         struct sockaddr_in6 *sin6;
 627         struct sockaddr_in *sin4;
 628         const char *bindaddr;
 629         const char *filename;
 630         int filenamelen, type;
 631         int low, pasv, verbose;
 632         int e, sd = -1;
 633         socklen_t l;
 634         char *s;
 635         FILE *df;
 636
 637         /* check flags */
 638         low = CHECK_FLAG('l');
 639         pasv = CHECK_FLAG('p');
 640         verbose = CHECK_FLAG('v');
 641
 642         /* passive mode */
 643         if (!pasv)
 644                 pasv = ((s = getenv("FTP_PASSIVE_MODE")) != NULL &&
 645                     strncasecmp(s, "no", 2) != 0);
 646
 647         /* isolate filename */
 648         filename = _ftp_filename(file, &filenamelen, &type);
 649
 650         /* set transfer mode and data type */
 651         if ((e = _ftp_mode_type(conn, 0, type)) != FTP_OK)
 652                 goto ouch;
 653
 654         /* find our own address, bind, and listen */
 655         l = sizeof(sa);
 656         if (getsockname(conn->sd, (struct sockaddr *)(void *)&sa, &l) == -1)
 657                 goto sysouch;
 658         if (sa.ss_family == AF_INET6)
 659                 unmappedaddr((struct sockaddr_in6 *)(void *)&sa);
 660
 661         /* open data socket */
 662         if ((sd = socket(sa.ss_family, SOCK_STREAM, IPPROTO_TCP)) == -1) {
 663                 _fetch_syserr();
 664                 return (NULL);
 665         }
 666
 667         if (pasv) {
 668                 u_char addr[64];
 669                 char *ln, *p;
 670                 unsigned int i;
 671                 int port;
 672
 673                 /* send PASV command */
 674                 if (verbose)
 675                         _fetch_info("setting passive mode");
 676                 switch (sa.ss_family) {
 677                 case AF_INET:
 678                         if ((e = _ftp_cmd(conn, "PASV")) != FTP_PASSIVE_MODE)
 679                                 goto ouch;
 680                         break;
 681                 case AF_INET6:
 682                         if ((e = _ftp_cmd(conn, "EPSV")) != FTP_EPASSIVE_MODE) {
 683                                 if (e == -1)
 684                                         goto ouch;
 685                                 if ((e = _ftp_cmd(conn, "LPSV")) !=
 686                                     FTP_LPASSIVE_MODE)
 687                                         goto ouch;
 688                         }
 689                         break;
 690                 default:
 691                         e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
 692                         goto ouch;
 693                 }
 694
 695                 /*
 696                  * Find address and port number. The reply to the PASV command
 697                  * is IMHO the one and only weak point in the FTP protocol.
 698                  */
 699                 ln = conn->buf;
 700                 switch (e) {
 701                 case FTP_PASSIVE_MODE:
 702                 case FTP_LPASSIVE_MODE:
 703                         for (p = ln + 3; *p && !isdigit((unsigned)*p); p++)
 704                                 /* nothing */ ;
 705                         if (!*p) {
 706                                 e = FTP_PROTOCOL_ERROR;
 707                                 goto ouch;
 708                         }
 709                         l = (e == FTP_PASSIVE_MODE ? 6 : 21);
 710                         for (i = 0; *p && i < l; i++, p++)
 711                                 addr[i] = (unsigned char) strtol(p, &p, 10);
 712                         if (i < l) {
 713                                 e = FTP_PROTOCOL_ERROR;
 714                                 goto ouch;
 715                         }
 716                         break;
 717                 case FTP_EPASSIVE_MODE:
 718                         for (p = ln + 3; *p && *p != '('; p++)
 719                                 /* nothing */ ;
 720                         if (!*p) {
 721                                 e = FTP_PROTOCOL_ERROR;
 722                                 goto ouch;
 723                         }
 724                         ++p;
 725                         if (sscanf(p, "%c%c%c%d%c", &addr[0], &addr[1], &addr[2],
 726                                 &port, &addr[3]) != 5 ||
 727                             addr[0] != addr[1] ||
 728                             addr[0] != addr[2] || addr[0] != addr[3]) {
 729                                 e = FTP_PROTOCOL_ERROR;
 730                                 goto ouch;
 731                         }
 732                         break;
 733                 }
 734
 735                 /* seek to required offset */
 736                 if (offset)
 737                         if (_ftp_cmd(conn, "REST %lu", (u_long)offset) != FTP_FILE_OK)
 738                                 goto sysouch;
 739
 740                 /* construct sockaddr for data socket */
 741                 l = sizeof(sa);
 742                 if (getpeername(conn->sd, (struct sockaddr *)(void *)&sa, &l) == -1)
 743                         goto sysouch;
 744                 if (sa.ss_family == AF_INET6)
 745                         unmappedaddr((struct sockaddr_in6 *)(void *)&sa);
 746                 switch (sa.ss_family) {
 747                 case AF_INET6:
 748                         sin6 = (struct sockaddr_in6 *)(void *)&sa;
 749                         if (e == FTP_EPASSIVE_MODE)
 750                                 sin6->sin6_port = htons(port);
 751                         else {
 752                                 bcopy(addr + 2, (char *)(void *)&sin6->sin6_addr, 16);
 753                                 bcopy(addr + 19, (char *)(void *)&sin6->sin6_port, 2);
 754                         }
 755                         break;
 756                 case AF_INET:
 757                         sin4 = (struct sockaddr_in *)(void *)&sa;
 758                         if (e == FTP_EPASSIVE_MODE)
 759                                 sin4->sin_port = htons(port);
 760                         else {
 761                                 bcopy(addr, (char *)(void *)&sin4->sin_addr, 4);
 762                                 bcopy(addr + 4, (char *)(void *)&sin4->sin_port, 2);
 763                         }
 764                         break;
 765                 default:
 766                         e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
 767                         break;
 768                 }
 769
 770                 /* connect to data port */
 771                 if (verbose)
 772                         _fetch_info("opening data connection");
 773                 bindaddr = getenv("FETCH_BIND_ADDRESS");
 774                 if (bindaddr != NULL && *bindaddr != '\0' &&
 775                     _fetch_bind(sd, sa.ss_family, bindaddr) != 0)
 776                         goto sysouch;
 777                 if (connect(sd, (struct sockaddr *)(void *)&sa, (unsigned)sa.ss_len) == -1)
 778                         goto sysouch;
 779
 780                 /* make the server initiate the transfer */
 781                 if (verbose)
 782                         _fetch_info("initiating transfer");
 783                 e = _ftp_cmd(conn, "%s %.*s", oper, filenamelen, filename);
 784                 if (e != FTP_CONNECTION_ALREADY_OPEN && e != FTP_OPEN_DATA_CONNECTION)
 785                         goto ouch;
 786
 787         } else {
 788                 u_int32_t a;
 789                 u_short p;
 790                 int arg, d;
 791                 char *ap;
 792                 char hname[INET6_ADDRSTRLEN];
 793
 794                 switch (sa.ss_family) {
 795                 case AF_INET6:
 796                         ((struct sockaddr_in6 *)(void *)&sa)->sin6_port = 0;
 797 #ifdef IPV6_PORTRANGE
 798                         arg = low ? IPV6_PORTRANGE_DEFAULT : IPV6_PORTRANGE_HIGH;
 799                         if (setsockopt(sd, IPPROTO_IPV6, IPV6_PORTRANGE,
 800                                 (char *)(void *)&arg, sizeof(arg)) == -1)
 801                                 goto sysouch;
 802 #endif
 803                         break;
 804                 case AF_INET:
 805                         ((struct sockaddr_in *)(void *)&sa)->sin_port = 0;
 806                         arg = low ? IP_PORTRANGE_DEFAULT : IP_PORTRANGE_HIGH;
 807                         if (setsockopt(sd, IPPROTO_IP, IP_PORTRANGE,
 808                                 (char *)(void *)&arg, sizeof(arg)) == -1)
 809                                 goto sysouch;
 810                         break;
 811                 }
 812                 if (verbose)
 813                         _fetch_info("binding data socket");
 814                 if (bind(sd, (struct sockaddr *)(void *)&sa, (unsigned) sa.ss_len) == -1)
 815                         goto sysouch;
 816                 if (listen(sd, 1) == -1)
 817                         goto sysouch;
 818
 819                 /* find what port we're on and tell the server */
 820                 if (getsockname(sd, (struct sockaddr *)(void *)&sa, &l) == -1)
 821                         goto sysouch;
 822                 switch (sa.ss_family) {
 823                 case AF_INET:
 824                         sin4 = (struct sockaddr_in *)(void *)&sa;
 825                         a = ntohl(sin4->sin_addr.s_addr);
 826                         p = ntohs(sin4->sin_port);
 827                         e = _ftp_cmd(conn, "PORT %d,%d,%d,%d,%d,%d",
 828                             (a >> 24) & 0xff, (a >> 16) & 0xff,
 829                             (a >> 8) & 0xff, a & 0xff,
 830                             ((unsigned)p >> 8) & 0xff, p & 0xff);
 831                         break;
 832                 case AF_INET6:
 833 #define UC(b)   (((int)b)&0xff)
 834                         e = -1;
 835                         sin6 = (struct sockaddr_in6 *)(void *)&sa;
 836                         sin6->sin6_scope_id = 0;
 837                         if (getnameinfo((struct sockaddr *)(void *)&sa,
 838                                 (unsigned)sa.ss_len,
 839                                 hname, sizeof(hname),
 840                                 NULL, 0, NI_NUMERICHOST) == 0) {
 841                                 e = _ftp_cmd(conn, "EPRT |%d|%s|%d|", 2, hname,
 842                                     htons(sin6->sin6_port));
 843                                 if (e == -1)
 844                                         goto ouch;
 845                         }
 846                         if (e != FTP_OK) {
 847                                 ap = (char *)(void *)&sin6->sin6_addr;
 848                                 e = _ftp_cmd(conn,
 849                                     "LPRT %d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d",
 850                                     6, 16,
 851                                     UC(ap[0]), UC(ap[1]), UC(ap[2]), UC(ap[3]),
 852                                     UC(ap[4]), UC(ap[5]), UC(ap[6]), UC(ap[7]),
 853                                     UC(ap[8]), UC(ap[9]), UC(ap[10]), UC(ap[11]),
 854                                     UC(ap[12]), UC(ap[13]), UC(ap[14]), UC(ap[15]),
 855                                     2,
 856                                     ((unsigned)ntohs(sin6->sin6_port) >> 8) & 0xff,
 857                                     ntohs(sin6->sin6_port)        & 0xff);
 858                         }
 859                         break;
 860                 default:
 861                         e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
 862                         goto ouch;
 863                 }
 864                 if (e != FTP_OK)
 865                         goto ouch;
 866
 867                 /* seek to required offset */
 868                 if (offset)
 869                         if (_ftp_cmd(conn, "REST %ju", (uintmax_t)offset) != FTP_FILE_OK)
 870                                 goto sysouch;
 871
 872                 /* make the server initiate the transfer */
 873                 if (verbose)
 874                         _fetch_info("initiating transfer");
 875                 e = _ftp_cmd(conn, "%s %.*s", oper, filenamelen, filename);
 876                 if (e != FTP_CONNECTION_ALREADY_OPEN && e != FTP_OPEN_DATA_CONNECTION)
 877                         goto ouch;
 878
 879                 /* accept the incoming connection and go to town */
 880                 if ((d = accept(sd, NULL, NULL)) == -1)
 881                         goto sysouch;
 882                 close(sd);
 883                 sd = d;
 884         }
 885
 886         if ((df = _ftp_setup(conn, _fetch_reopen(sd), mode)) == NULL)
 887                 goto sysouch;
 888         return (df);
 889
 890 sysouch:
 891         _fetch_syserr();
 892         if (sd >= 0)
 893                 close(sd);
 894         return (NULL);
 895
 896 ouch:
 897         if (e != -1)
 898                 _ftp_seterr(e);
 899         if (sd >= 0)
 900                 close(sd);
 901         return (NULL);
 902 }
 903
 904 /*
 905  * Authenticate
 906  */
 907 static int
 908 _ftp_authenticate(conn_t *conn, struct url *url, struct url *purl)
 909 {
 910         const char *user, *pwd, *logname;
 911         char pbuf[MAXHOSTNAMELEN + MAXLOGNAME + 1];
 912         int e, len;
 913
 914         /* XXX FTP_AUTH, and maybe .netrc */
 915
 916         /* send user name and password */
 917         if (url->user[0] == '\0')
 918                 _fetch_netrc_auth(url);
 919         user = url->user;
 920         if (*user == '\0')
 921                 user = getenv("FTP_LOGIN");
 922         if (user == NULL || *user == '\0')
 923                 user = FTP_ANONYMOUS_USER;
 924         if (purl && url->port == _fetch_default_port(url->scheme))
 925                 e = _ftp_cmd(conn, "USER %s@%s", user, url->host);
 926         else if (purl)
 927                 e = _ftp_cmd(conn, "USER %s@%s@%d", user, url->host, url->port);
 928         else
 929                 e = _ftp_cmd(conn, "USER %s", user);
 930
 931         /* did the server request a password? */
 932         if (e == FTP_NEED_PASSWORD) {
 933                 pwd = url->pwd;
 934                 if (*pwd == '\0')
 935                         pwd = getenv("FTP_PASSWORD");
 936                 if (pwd == NULL || *pwd == '\0') {
 937                         if ((logname = getlogin()) == 0)
 938                                 logname = FTP_ANONYMOUS_USER;
 939                         if ((len = snprintf(pbuf, MAXLOGNAME + 1, "%s@", logname)) < 0)
 940                                 len = 0;
 941                         else if (len > MAXLOGNAME)
 942                                 len = MAXLOGNAME;
 943                         gethostname(pbuf + len, sizeof(pbuf) - len);
 944                         pwd = pbuf;
 945                 }
 946                 e = _ftp_cmd(conn, "PASS %s", pwd);
 947         }
 948
 949         return (e);
 950 }
 951
 952 /*
 953  * Log on to FTP server
 954  */
 955 static conn_t *
 956 _ftp_connect(struct url *url, struct url *purl, const char *flags)
 957 {
 958         conn_t *conn;
 959         int e, direct, verbose;
 960 #ifdef INET6
 961         int af = AF_UNSPEC;
 962 #else
 963         int af = AF_INET;
 964 #endif
 965
 966         direct = CHECK_FLAG('d');
 967         verbose = CHECK_FLAG('v');
 968         if (CHECK_FLAG('4'))
 969                 af = AF_INET;
 970         else if (CHECK_FLAG('6'))
 971                 af = AF_INET6;
 972
 973         if (direct)
 974                 purl = NULL;
 975
 976         /* check for proxy */
 977         if (purl) {
 978                 /* XXX proxy authentication! */
 979                 conn = _fetch_connect(purl->host, purl->port, af, verbose);
 980         } else {
 981                 /* no proxy, go straight to target */
 982                 conn = _fetch_connect(url->host, url->port, af, verbose);
 983                 purl = NULL;
 984         }
 985
 986         /* check connection */
 987         if (conn == NULL)
 988                 /* _fetch_connect() has already set an error code */
 989                 return (NULL);
 990
 991         /* expect welcome message */
 992         if ((e = _ftp_chkerr(conn)) != FTP_SERVICE_READY)
 993                 goto fouch;
 994
 995         /* authenticate */
 996         if ((e = _ftp_authenticate(conn, url, purl)) != FTP_LOGGED_IN)
 997                 goto fouch;
 998
 999         /* TODO: Request extended features supported, if any (RFC 3659). */
1000
1001         /* done */
1002         return (conn);
1003
1004 fouch:
1005         if (e != -1)
1006                 _ftp_seterr(e);
1007         _fetch_close(conn);
1008         return (NULL);
1009 }
1010
1011 /*
1012  * Disconnect from server
1013  */
1014 static void
1015 _ftp_disconnect(conn_t *conn)
1016 {
1017         (void)_ftp_cmd(conn, "QUIT");
1018         if (conn == cached_connection && conn->ref == 1)
1019                 cached_connection = NULL;
1020         _fetch_close(conn);
1021 }
1022
1023 /*
1024  * Check if we're already connected
1025  */
1026 static int
1027 _ftp_isconnected(struct url *url)
1028 {
1029         return (cached_connection
1030             && (strcmp(url->host, cached_host.host) == 0)
1031             && (strcmp(url->user, cached_host.user) == 0)
1032             && (strcmp(url->pwd, cached_host.pwd) == 0)
1033             && (url->port == cached_host.port));
1034 }
1035
1036 /*
1037  * Check the cache, reconnect if no luck
1038  */
1039 static conn_t *
1040 _ftp_cached_connect(struct url *url, struct url *purl, const char *flags)
1041 {
1042         conn_t *conn;
1043         int e;
1044
1045         /* set default port */
1046         if (!url->port)
1047                 url->port = _fetch_default_port(url->scheme);
1048
1049         /* try to use previously cached connection */
1050         if (_ftp_isconnected(url)) {
1051                 e = _ftp_cmd(cached_connection, "NOOP");
1052                 if (e == FTP_OK || e == FTP_SYNTAX_ERROR)
1053                         return (_fetch_ref(cached_connection));
1054         }
1055
1056         /* connect to server */
1057         if ((conn = _ftp_connect(url, purl, flags)) == NULL)
1058                 return (NULL);
1059         if (cached_connection)
1060                 _ftp_disconnect(cached_connection);
1061         cached_connection = _fetch_ref(conn);
1062         memcpy(&cached_host, url, sizeof(*url));
1063         return (conn);
1064 }
1065
1066 /*
1067  * Check the proxy settings
1068  */
1069 static struct url *
1070 _ftp_get_proxy(const char *flags)
1071 {
1072         struct url *purl;
1073         char *p;
1074
1075         if (flags != NULL && strchr(flags, 'd') != NULL)
1076                 return (NULL);
1077         if (((p = getenv("FTP_PROXY")) || (p = getenv("ftp_proxy")) ||
1078                 (p = getenv("HTTP_PROXY")) || (p = getenv("http_proxy"))) &&
1079             *p && (purl = fetchParseURL(p)) != NULL) {
1080                 if (!*purl->scheme) {
1081                         if (getenv("FTP_PROXY") || getenv("ftp_proxy"))
1082                                 strcpy(purl->scheme, SCHEME_FTP);
1083                         else
1084                                 strcpy(purl->scheme, SCHEME_HTTP);
1085                 }
1086                 if (!purl->port)
1087                         purl->port = _fetch_default_proxy_port(purl->scheme);
1088                 if (strcasecmp(purl->scheme, SCHEME_FTP) == 0 ||
1089                     strcasecmp(purl->scheme, SCHEME_HTTP) == 0)
1090                         return (purl);
1091                 fetchFreeURL(purl);
1092         }
1093         return (NULL);
1094 }
1095
1096 /*
1097  * Process an FTP request
1098  */
1099 FILE *
1100 _ftp_request(struct url *url, const char *op, struct url_stat *us,
1101     struct url *purl, const char *flags)
1102 {
1103         conn_t *conn;
1104         int oflag;
1105
1106         /* check if we should use HTTP instead */
1107         if (purl && strcasecmp(purl->scheme, SCHEME_HTTP) == 0) {
1108                 if (strcmp(op, "STAT") == 0)
1109                         return (_http_request(url, "HEAD", us, purl, flags));
1110                 else if (strcmp(op, "RETR") == 0)
1111                         return (_http_request(url, "GET", us, purl, flags));
1112                 /*
1113                  * Our HTTP code doesn't support PUT requests yet, so try
1114                  * a direct connection.
1115                  */
1116         }
1117
1118         /* connect to server */
1119         conn = _ftp_cached_connect(url, purl, flags);
1120         if (purl)
1121                 fetchFreeURL(purl);
1122         if (conn == NULL)
1123                 return (NULL);
1124
1125         /* change directory */
1126         if (_ftp_cwd(conn, url->doc) == -1)
1127                 return (NULL);
1128
1129         /* stat file */
1130         if (us && _ftp_stat(conn, url->doc, us) == -1
1131             && fetchLastErrCode != FETCH_PROTO
1132             && fetchLastErrCode != FETCH_UNAVAIL)
1133                 return (NULL);
1134
1135         /* just a stat */
1136         if (strcmp(op, "STAT") == 0)
1137                 return (FILE *)1; /* bogus return value */
1138         if (strcmp(op, "STOR") == 0 || strcmp(op, "APPE") == 0)
1139                 oflag = O_WRONLY;
1140         else
1141                 oflag = O_RDONLY;
1142
1143         /* initiate the transfer */
1144         return (_ftp_transfer(conn, op, url->doc, oflag, url->offset, flags));
1145 }
1146
1147 /*
1148  * Get and stat file
1149  */
1150 FILE *
1151 fetchXGetFTP(struct url *url, struct url_stat *us, const char *flags)
1152 {
1153         return (_ftp_request(url, "RETR", us, _ftp_get_proxy(flags), flags));
1154 }
1155
1156 /*
1157  * Get file
1158  */
1159 FILE *
1160 fetchGetFTP(struct url *url, const char *flags)
1161 {
1162         return (fetchXGetFTP(url, NULL, flags));
1163 }
1164
1165 /*
1166  * Put file
1167  */
1168 FILE *
1169 fetchPutFTP(struct url *url, const char *flags)
1170 {
1171
1172         return (_ftp_request(url, CHECK_FLAG('a') ? "APPE" : "STOR", NULL,
1173             _ftp_get_proxy(flags), flags));
1174 }
1175
1176 /*
1177  * Get file stats
1178  */
1179 int
1180 fetchStatFTP(struct url *url, struct url_stat *us, const char *flags)
1181 {
1182         FILE *f;
1183
1184         f = _ftp_request(url, "STAT", us, _ftp_get_proxy(flags), flags);
1185         if (f == NULL)
1186                 return (-1);
1187         return (0);
1188 }
1189
1190 /*
1191  * List a directory
1192  */
1193 /* ARGSUSED0 */
1194 struct url_ent *
1195 fetchListFTP(struct url *url __unused, const char *flags __unused)
1196 {
1197         warnx("fetchListFTP(): not implemented");
1198         return (NULL);
1199 }