lib/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  * $FreeBSD: src/lib/libfetch/ftp.c,v 1.102 2008/02/08 09:48:48 des Exp $
  29  * $DragonFly: src/lib/libfetch/ftp.c,v 1.4 2007/08/05 21:48:12 swildner Exp $
  30  */
  31
  32 /*
  33  * Portions of this code were taken from or based on ftpio.c:
  34  *
  35  * ----------------------------------------------------------------------------
  36  * "THE BEER-WARE LICENSE" (Revision 42):
  37  * <phk@FreeBSD.org> wrote this file.  As long as you retain this notice you
  38  * can do whatever you want with this stuff. If we meet some day, and you think
  39  * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
  40  * ----------------------------------------------------------------------------
  41  *
  42  * Major Changelog:
  43  *
  44  * Dag-Erling Coïdan Smørgrav
  45  * 9 Jun 1998
  46  *
  47  * Incorporated into libfetch
  48  *
  49  * Jordan K. Hubbard
  50  * 17 Jan 1996
  51  *
  52  * Turned inside out. Now returns xfers as new file ids, not as a special
  53  * `state' of FTP_t
  54  *
  55  * $ftpioId: ftpio.c,v 1.30 1998/04/11 07:28:53 phk Exp $
  56  *
  57  */
  58
  59 #include <sys/param.h>
  60 #include <sys/socket.h>
  61 #include <netinet/in.h>
  62
  63 #include <ctype.h>
  64 #include <err.h>
  65 #include <errno.h>
  66 #include <fcntl.h>
  67 #include <netdb.h>
  68 #include <stdarg.h>
  69 #include <stdint.h>
  70 #include <stdio.h>
  71 #include <stdlib.h>
  72 #include <string.h>
  73 #include <time.h>
  74 #include <unistd.h>
  75
  76 #include "fetch.h"
  77 #include "common.h"
  78 #include "ftperr.h"
  79
  80 #define FTP_ANONYMOUS_USER      "anonymous"
  81
  82 #define FTP_CONNECTION_ALREADY_OPEN     125
  83 #define FTP_OPEN_DATA_CONNECTION        150
  84 #define FTP_OK                          200
  85 #define FTP_FILE_STATUS                 213
  86 #define FTP_SERVICE_READY               220
  87 #define FTP_TRANSFER_COMPLETE           226
  88 #define FTP_PASSIVE_MODE                227
  89 #define FTP_LPASSIVE_MODE               228
  90 #define FTP_EPASSIVE_MODE               229
  91 #define FTP_LOGGED_IN                   230
  92 #define FTP_FILE_ACTION_OK              250
  93 #define FTP_DIRECTORY_CREATED           257 /* multiple meanings */
  94 #define FTP_FILE_CREATED                257 /* multiple meanings */
  95 #define FTP_WORKING_DIRECTORY           257 /* multiple meanings */
  96 #define FTP_NEED_PASSWORD               331
  97 #define FTP_NEED_ACCOUNT                332
  98 #define FTP_FILE_OK                     350
  99 #define FTP_SYNTAX_ERROR                500
 100 #define FTP_PROTOCOL_ERROR              999
 101
 102 static struct url cached_host;
 103 static conn_t   *cached_connection;
 104
 105 #define isftpreply(foo)                         \
 106         (isdigit((unsigned char)foo[0]) &&      \
 107             isdigit((unsigned char)foo[1]) &&   \
 108             isdigit((unsigned char)foo[2]) &&   \
 109             (foo[3] == ' ' || foo[3] == '\0'))
 110 #define isftpinfo(foo) \
 111         (isdigit((unsigned char)foo[0]) &&      \
 112             isdigit((unsigned char)foo[1]) &&   \
 113             isdigit((unsigned char)foo[2]) &&   \
 114             foo[3] == '-')
 115
 116 /*
 117  * Translate IPv4 mapped IPv6 address to IPv4 address
 118  */
 119 static void
 120 unmappedaddr(struct sockaddr_in6 *sin6)
 121 {
 122         struct sockaddr_in *sin4;
 123         u_int32_t addr;
 124         int port;
 125
 126         if (sin6->sin6_family != AF_INET6 ||
 127             !IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
 128                 return;
 129         sin4 = (struct sockaddr_in *)sin6;
 130         addr = *(u_int32_t *)&sin6->sin6_addr.s6_addr[12];
 131         port = sin6->sin6_port;
 132         memset(sin4, 0, sizeof(struct sockaddr_in));
 133         sin4->sin_addr.s_addr = addr;
 134         sin4->sin_port = port;
 135         sin4->sin_family = AF_INET;
 136         sin4->sin_len = sizeof(struct sockaddr_in);
 137 }
 138
 139 /*
 140  * Get server response
 141  */
 142 static int
 143 ftp_chkerr(conn_t *conn)
 144 {
 145         if (fetch_getln(conn) == -1) {
 146                 fetch_syserr();
 147                 return (-1);
 148         }
 149         if (isftpinfo(conn->buf)) {
 150                 while (conn->buflen && !isftpreply(conn->buf)) {
 151                         if (fetch_getln(conn) == -1) {
 152                                 fetch_syserr();
 153                                 return (-1);
 154                         }
 155                 }
 156         }
 157
 158         while (conn->buflen &&
 159             isspace((unsigned char)conn->buf[conn->buflen - 1]))
 160                 conn->buflen--;
 161         conn->buf[conn->buflen] = '\0';
 162
 163         if (!isftpreply(conn->buf)) {
 164                 ftp_seterr(FTP_PROTOCOL_ERROR);
 165                 return (-1);
 166         }
 167
 168         conn->err = (conn->buf[0] - '0') * 100
 169             + (conn->buf[1] - '0') * 10
 170             + (conn->buf[2] - '0');
 171
 172         return (conn->err);
 173 }
 174
 175 /*
 176  * Send a command and check reply
 177  */
 178 static int
 179 ftp_cmd(conn_t *conn, const char *fmt, ...)
 180 {
 181         va_list ap;
 182         size_t len;
 183         char *msg;
 184         int r;
 185
 186         va_start(ap, fmt);
 187         len = vasprintf(&msg, fmt, ap);
 188         va_end(ap);
 189
 190         if (msg == NULL) {
 191                 errno = ENOMEM;
 192                 fetch_syserr();
 193                 return (-1);
 194         }
 195
 196         r = fetch_putln(conn, msg, len);
 197         free(msg);
 198
 199         if (r == -1) {
 200                 fetch_syserr();
 201                 return (-1);
 202         }
 203
 204         return (ftp_chkerr(conn));
 205 }
 206
 207 /*
 208  * Return a pointer to the filename part of a path
 209  */
 210 static const char *
 211 ftp_filename(const char *file, int *len, int *type)
 212 {
 213         const char *s;
 214
 215         if ((s = strrchr(file, '/')) == NULL)
 216                 s = file;
 217         else
 218                 s = s + 1;
 219         *len = strlen(s);
 220         if (*len > 7 && strncmp(s + *len - 7, ";type=", 6) == 0) {
 221                 *type = s[*len - 1];
 222                 *len -= 7;
 223         } else {
 224                 *type = '\0';
 225         }
 226         return (s);
 227 }
 228
 229 /*
 230  * Get current working directory from the reply to a CWD, PWD or CDUP
 231  * command.
 232  */
 233 static int
 234 ftp_pwd(conn_t *conn, char *pwd, size_t pwdlen)
 235 {
 236         char *src, *dst, *end;
 237         int q;
 238
 239         if (conn->err != FTP_WORKING_DIRECTORY &&
 240             conn->err != FTP_FILE_ACTION_OK)
 241                 return (FTP_PROTOCOL_ERROR);
 242         end = conn->buf + conn->buflen;
 243         src = conn->buf + 4;
 244         if (src >= end || *src++ != '"')
 245                 return (FTP_PROTOCOL_ERROR);
 246         for (q = 0, dst = pwd; src < end && pwdlen--; ++src) {
 247                 if (!q && *src == '"')
 248                         q = 1;
 249                 else if (q && *src != '"')
 250                         break;
 251                 else if (q)
 252                         *dst++ = '"', q = 0;
 253                 else
 254                         *dst++ = *src;
 255         }
 256         if (!pwdlen)
 257                 return (FTP_PROTOCOL_ERROR);
 258         *dst = '\0';
 259 #if 0
 260         DEBUG(fprintf(stderr, "pwd: [%s]\n", pwd));
 261 #endif
 262         return (FTP_OK);
 263 }
 264
 265 /*
 266  * Change working directory to the directory that contains the specified
 267  * file.
 268  */
 269 static int
 270 ftp_cwd(conn_t *conn, const char *file)
 271 {
 272         const char *beg, *end;
 273         char pwd[PATH_MAX];
 274         int e, i, len;
 275
 276         /* If no slashes in name, no need to change dirs. */
 277         if ((end = strrchr(file, '/')) == NULL)
 278                 return (0);
 279         if ((e = ftp_cmd(conn, "PWD")) != FTP_WORKING_DIRECTORY ||
 280             (e = ftp_pwd(conn, pwd, sizeof(pwd))) != FTP_OK) {
 281                 ftp_seterr(e);
 282                 return (-1);
 283         }
 284         for (;;) {
 285                 len = strlen(pwd);
 286
 287                 /* Look for a common prefix between PWD and dir to fetch. */
 288                 for (i = 0; i <= len && i <= end - file; ++i)
 289                         if (pwd[i] != file[i])
 290                                 break;
 291 #if 0
 292                 DEBUG(fprintf(stderr, "have: [%.*s|%s]\n", i, pwd, pwd + i));
 293                 DEBUG(fprintf(stderr, "want: [%.*s|%s]\n", i, file, file + i));
 294 #endif
 295                 /* Keep going up a dir until we have a matching prefix. */
 296                 if (pwd[i] == '\0' && (file[i - 1] == '/' || file[i] == '/'))
 297                         break;
 298                 if ((e = ftp_cmd(conn, "CDUP")) != FTP_FILE_ACTION_OK ||
 299                     (e = ftp_cmd(conn, "PWD")) != FTP_WORKING_DIRECTORY ||
 300                     (e = ftp_pwd(conn, pwd, sizeof(pwd))) != FTP_OK) {
 301                         ftp_seterr(e);
 302                         return (-1);
 303                 }
 304         }
 305
 306 #ifdef FTP_COMBINE_CWDS
 307         /* Skip leading slashes, even "////". */
 308         for (beg = file + i; beg < end && *beg == '/'; ++beg, ++i)
 309                 /* nothing */ ;
 310
 311         /* If there is no trailing dir, we're already there. */
 312         if (beg >= end)
 313                 return (0);
 314
 315         /* Change to the directory all in one chunk (e.g., foo/bar/baz). */
 316         e = ftp_cmd(conn, "CWD %.*s", (int)(end - beg), beg);
 317         if (e == FTP_FILE_ACTION_OK)
 318                 return (0);
 319 #endif /* FTP_COMBINE_CWDS */
 320
 321         /* That didn't work so go back to legacy behavior (multiple CWDs). */
 322         for (beg = file + i; beg < end; beg = file + i + 1) {
 323                 while (*beg == '/')
 324                         ++beg, ++i;
 325                 for (++i; file + i < end && file[i] != '/'; ++i)
 326                         /* nothing */ ;
 327                 e = ftp_cmd(conn, "CWD %.*s", file + i - beg, beg);
 328                 if (e != FTP_FILE_ACTION_OK) {
 329                         ftp_seterr(e);
 330                         return (-1);
 331                 }
 332         }
 333         return (0);
 334 }
 335
 336 /*
 337  * Set transfer mode and data type
 338  */
 339 static int
 340 ftp_mode_type(conn_t *conn, int mode, int type)
 341 {
 342         int e;
 343
 344         switch (mode) {
 345         case 0:
 346         case 's':
 347                 mode = 'S';
 348         case 'S':
 349                 break;
 350         default:
 351                 return (FTP_PROTOCOL_ERROR);
 352         }
 353         if ((e = ftp_cmd(conn, "MODE %c", mode)) != FTP_OK) {
 354                 if (mode == 'S') {
 355                         /*
 356                          * Stream mode is supposed to be the default - so
 357                          * much so that some servers not only do not
 358                          * support any other mode, but do not support the
 359                          * MODE command at all.
 360                          *
 361                          * If "MODE S" fails, it is unlikely that we
 362                          * previously succeeded in setting a different
 363                          * mode.  Therefore, we simply hope that the
 364                          * server is already in the correct mode, and
 365                          * silently ignore the failure.
 366                          */
 367                 } else {
 368                         return (e);
 369                 }
 370         }
 371
 372         switch (type) {
 373         case 0:
 374         case 'i':
 375                 type = 'I';
 376         case 'I':
 377                 break;
 378         case 'a':
 379                 type = 'A';
 380         case 'A':
 381                 break;
 382         case 'd':
 383                 type = 'D';
 384         case 'D':
 385                 /* can't handle yet */
 386         default:
 387                 return (FTP_PROTOCOL_ERROR);
 388         }
 389         if ((e = ftp_cmd(conn, "TYPE %c", type)) != FTP_OK)
 390                 return (e);
 391
 392         return (FTP_OK);
 393 }
 394
 395 /*
 396  * Request and parse file stats
 397  */
 398 static int
 399 ftp_stat(conn_t *conn, const char *file, struct url_stat *us)
 400 {
 401         char *ln;
 402         const char *filename;
 403         int filenamelen, type;
 404         struct tm tm;
 405         time_t t;
 406         int e;
 407
 408         us->size = -1;
 409         us->atime = us->mtime = 0;
 410
 411         filename = ftp_filename(file, &filenamelen, &type);
 412
 413         if ((e = ftp_mode_type(conn, 0, type)) != FTP_OK) {
 414                 ftp_seterr(e);
 415                 return (-1);
 416         }
 417
 418         e = ftp_cmd(conn, "SIZE %.*s", filenamelen, filename);
 419         if (e != FTP_FILE_STATUS) {
 420                 ftp_seterr(e);
 421                 return (-1);
 422         }
 423         for (ln = conn->buf + 4; *ln && isspace((unsigned char)*ln); ln++)
 424                 /* nothing */ ;
 425         for (us->size = 0; *ln && isdigit((unsigned char)*ln); ln++)
 426                 us->size = us->size * 10 + *ln - '0';
 427         if (*ln && !isspace((unsigned char)*ln)) {
 428                 ftp_seterr(FTP_PROTOCOL_ERROR);
 429                 us->size = -1;
 430                 return (-1);
 431         }
 432         if (us->size == 0)
 433                 us->size = -1;
 434         DEBUG(fprintf(stderr, "size: [%lld]\n", (long long)us->size));
 435
 436         e = ftp_cmd(conn, "MDTM %.*s", filenamelen, filename);
 437         if (e != FTP_FILE_STATUS) {
 438                 ftp_seterr(e);
 439                 return (-1);
 440         }
 441         for (ln = conn->buf + 4; *ln && isspace((unsigned char)*ln); ln++)
 442                 /* nothing */ ;
 443         switch (strspn(ln, "0123456789")) {
 444         case 14:
 445                 break;
 446         case 15:
 447                 ln++;
 448                 ln[0] = '2';
 449                 ln[1] = '0';
 450                 break;
 451         default:
 452                 ftp_seterr(FTP_PROTOCOL_ERROR);
 453                 return (-1);
 454         }
 455         if (sscanf(ln, "%04d%02d%02d%02d%02d%02d",
 456             &tm.tm_year, &tm.tm_mon, &tm.tm_mday,
 457             &tm.tm_hour, &tm.tm_min, &tm.tm_sec) != 6) {
 458                 ftp_seterr(FTP_PROTOCOL_ERROR);
 459                 return (-1);
 460         }
 461         tm.tm_mon--;
 462         tm.tm_year -= 1900;
 463         tm.tm_isdst = -1;
 464         t = timegm(&tm);
 465         if (t == (time_t)-1)
 466                 t = time(NULL);
 467         us->mtime = t;
 468         us->atime = t;
 469         DEBUG(fprintf(stderr,
 470             "last modified: [%04d-%02d-%02d %02d:%02d:%02d]\n",
 471             tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
 472             tm.tm_hour, tm.tm_min, tm.tm_sec));
 473         return (0);
 474 }
 475
 476 /*
 477  * I/O functions for FTP
 478  */
 479 struct ftpio {
 480         conn_t  *cconn;         /* Control connection */
 481         conn_t  *dconn;         /* Data connection */
 482         int      dir;           /* Direction */
 483         int      eof;           /* EOF reached */
 484         int      err;           /* Error code */
 485 };
 486
 487 static int       ftp_readfn(void *, char *, int);
 488 static int       ftp_writefn(void *, const char *, int);
 489 static fpos_t    ftp_seekfn(void *, fpos_t, int);
 490 static int       ftp_closefn(void *);
 491
 492 static int
 493 ftp_readfn(void *v, char *buf, int len)
 494 {
 495         struct ftpio *io;
 496         int r;
 497
 498         io = (struct ftpio *)v;
 499         if (io == NULL) {
 500                 errno = EBADF;
 501                 return (-1);
 502         }
 503         if (io->cconn == NULL || io->dconn == NULL || io->dir == O_WRONLY) {
 504                 errno = EBADF;
 505                 return (-1);
 506         }
 507         if (io->err) {
 508                 errno = io->err;
 509                 return (-1);
 510         }
 511         if (io->eof)
 512                 return (0);
 513         r = fetch_read(io->dconn, buf, len);
 514         if (r > 0)
 515                 return (r);
 516         if (r == 0) {
 517                 io->eof = 1;
 518                 return (0);
 519         }
 520         if (errno != EINTR)
 521                 io->err = errno;
 522         return (-1);
 523 }
 524
 525 static int
 526 ftp_writefn(void *v, const char *buf, int len)
 527 {
 528         struct ftpio *io;
 529         int w;
 530
 531         io = (struct ftpio *)v;
 532         if (io == NULL) {
 533                 errno = EBADF;
 534                 return (-1);
 535         }
 536         if (io->cconn == NULL || io->dconn == NULL || io->dir == O_RDONLY) {
 537                 errno = EBADF;
 538                 return (-1);
 539         }
 540         if (io->err) {
 541                 errno = io->err;
 542                 return (-1);
 543         }
 544         w = fetch_write(io->dconn, buf, len);
 545         if (w >= 0)
 546                 return (w);
 547         if (errno != EINTR)
 548                 io->err = errno;
 549         return (-1);
 550 }
 551
 552 static fpos_t
 553 ftp_seekfn(void *v, fpos_t pos __unused, int whence __unused)
 554 {
 555         struct ftpio *io;
 556
 557         io = (struct ftpio *)v;
 558         if (io == NULL) {
 559                 errno = EBADF;
 560                 return (-1);
 561         }
 562         errno = ESPIPE;
 563         return (-1);
 564 }
 565
 566 static int
 567 ftp_closefn(void *v)
 568 {
 569         struct ftpio *io;
 570         int r;
 571
 572         io = (struct ftpio *)v;
 573         if (io == NULL) {
 574                 errno = EBADF;
 575                 return (-1);
 576         }
 577         if (io->dir == -1)
 578                 return (0);
 579         if (io->cconn == NULL || io->dconn == NULL) {
 580                 errno = EBADF;
 581                 return (-1);
 582         }
 583         fetch_close(io->dconn);
 584         io->dir = -1;
 585         io->dconn = NULL;
 586         DEBUG(fprintf(stderr, "Waiting for final status\n"));
 587         r = ftp_chkerr(io->cconn);
 588         if (io->cconn == cached_connection && io->cconn->ref == 1)
 589                 cached_connection = NULL;
 590         fetch_close(io->cconn);
 591         free(io);
 592         return (r == FTP_TRANSFER_COMPLETE) ? 0 : -1;
 593 }
 594
 595 static FILE *
 596 ftp_setup(conn_t *cconn, conn_t *dconn, int mode)
 597 {
 598         struct ftpio *io;
 599         FILE *f;
 600
 601         if (cconn == NULL || dconn == NULL)
 602                 return (NULL);
 603         if ((io = malloc(sizeof(*io))) == NULL)
 604                 return (NULL);
 605         io->cconn = cconn;
 606         io->dconn = dconn;
 607         io->dir = mode;
 608         io->eof = io->err = 0;
 609         f = funopen(io, ftp_readfn, ftp_writefn, ftp_seekfn, ftp_closefn);
 610         if (f == NULL)
 611                 free(io);
 612         return (f);
 613 }
 614
 615 /*
 616  * Transfer file
 617  */
 618 static FILE *
 619 ftp_transfer(conn_t *conn, const char *oper, const char *file,
 620     int mode, off_t offset, const char *flags)
 621 {
 622         struct sockaddr_storage sa;
 623         struct sockaddr_in6 *sin6;
 624         struct sockaddr_in *sin4;
 625         const char *bindaddr;
 626         const char *filename;
 627         int filenamelen, type;
 628         int low, pasv, verbose;
 629         int e, sd = -1;
 630         socklen_t l;
 631         char *s;
 632         FILE *df;
 633
 634         /* check flags */
 635         low = CHECK_FLAG('l');
 636         pasv = CHECK_FLAG('p');
 637         verbose = CHECK_FLAG('v');
 638
 639         /* passive mode */
 640         if (!pasv)
 641                 pasv = ((s = getenv("FTP_PASSIVE_MODE")) != NULL &&
 642                     strncasecmp(s, "no", 2) != 0);
 643
 644         /* isolate filename */
 645         filename = ftp_filename(file, &filenamelen, &type);
 646
 647         /* set transfer mode and data type */
 648         if ((e = ftp_mode_type(conn, 0, type)) != FTP_OK)
 649                 goto ouch;
 650
 651         /* find our own address, bind, and listen */
 652         l = sizeof(sa);
 653         if (getsockname(conn->sd, (struct sockaddr *)&sa, &l) == -1)
 654                 goto sysouch;
 655         if (sa.ss_family == AF_INET6)
 656                 unmappedaddr((struct sockaddr_in6 *)&sa);
 657
 658         /* open data socket */
 659         if ((sd = socket(sa.ss_family, SOCK_STREAM, IPPROTO_TCP)) == -1) {
 660                 fetch_syserr();
 661                 return (NULL);
 662         }
 663
 664         if (pasv) {
 665                 u_char addr[64];
 666                 char *ln, *p;
 667                 unsigned int i;
 668                 int port;
 669
 670                 /* send PASV command */
 671                 if (verbose)
 672                         fetch_info("setting passive mode");
 673                 switch (sa.ss_family) {
 674                 case AF_INET:
 675                         if ((e = ftp_cmd(conn, "PASV")) != FTP_PASSIVE_MODE)
 676                                 goto ouch;
 677                         break;
 678                 case AF_INET6:
 679                         if ((e = ftp_cmd(conn, "EPSV")) != FTP_EPASSIVE_MODE) {
 680                                 if (e == -1)
 681                                         goto ouch;
 682                                 if ((e = ftp_cmd(conn, "LPSV")) !=
 683                                     FTP_LPASSIVE_MODE)
 684                                         goto ouch;
 685                         }
 686                         break;
 687                 default:
 688                         e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
 689                         goto ouch;
 690                 }
 691
 692                 /*
 693                  * Find address and port number. The reply to the PASV command
 694                  * is IMHO the one and only weak point in the FTP protocol.
 695                  */
 696                 ln = conn->buf;
 697                 switch (e) {
 698                 case FTP_PASSIVE_MODE:
 699                 case FTP_LPASSIVE_MODE:
 700                         for (p = ln + 3; *p && !isdigit((unsigned char)*p); p++)
 701                                 /* nothing */ ;
 702                         if (!*p) {
 703                                 e = FTP_PROTOCOL_ERROR;
 704                                 goto ouch;
 705                         }
 706                         l = (e == FTP_PASSIVE_MODE ? 6 : 21);
 707                         for (i = 0; *p && i < l; i++, p++)
 708                                 addr[i] = strtol(p, &p, 10);
 709                         if (i < l) {
 710                                 e = FTP_PROTOCOL_ERROR;
 711                                 goto ouch;
 712                         }
 713                         break;
 714                 case FTP_EPASSIVE_MODE:
 715                         for (p = ln + 3; *p && *p != '('; p++)
 716                                 /* nothing */ ;
 717                         if (!*p) {
 718                                 e = FTP_PROTOCOL_ERROR;
 719                                 goto ouch;
 720                         }
 721                         ++p;
 722                         if (sscanf(p, "%c%c%c%d%c", &addr[0], &addr[1], &addr[2],
 723                                 &port, &addr[3]) != 5 ||
 724                             addr[0] != addr[1] ||
 725                             addr[0] != addr[2] || addr[0] != addr[3]) {
 726                                 e = FTP_PROTOCOL_ERROR;
 727                                 goto ouch;
 728                         }
 729                         break;
 730                 }
 731
 732                 /* seek to required offset */
 733                 if (offset)
 734                         if (ftp_cmd(conn, "REST %lu", (u_long)offset) != FTP_FILE_OK)
 735                                 goto sysouch;
 736
 737                 /* construct sockaddr for data socket */
 738                 l = sizeof(sa);
 739                 if (getpeername(conn->sd, (struct sockaddr *)&sa, &l) == -1)
 740                         goto sysouch;
 741                 if (sa.ss_family == AF_INET6)
 742                         unmappedaddr((struct sockaddr_in6 *)&sa);
 743                 switch (sa.ss_family) {
 744                 case AF_INET6:
 745                         sin6 = (struct sockaddr_in6 *)&sa;
 746                         if (e == FTP_EPASSIVE_MODE)
 747                                 sin6->sin6_port = htons(port);
 748                         else {
 749                                 memcpy(&sin6->sin6_addr, addr + 2, 16);
 750                                 memcpy(&sin6->sin6_port, addr + 19, 2);
 751                         }
 752                         break;
 753                 case AF_INET:
 754                         sin4 = (struct sockaddr_in *)&sa;
 755                         if (e == FTP_EPASSIVE_MODE)
 756                                 sin4->sin_port = htons(port);
 757                         else {
 758                                 memcpy(&sin4->sin_addr, addr, 4);
 759                                 memcpy(&sin4->sin_port, addr + 4, 2);
 760                         }
 761                         break;
 762                 default:
 763                         e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
 764                         break;
 765                 }
 766
 767                 /* connect to data port */
 768                 if (verbose)
 769                         fetch_info("opening data connection");
 770                 bindaddr = getenv("FETCH_BIND_ADDRESS");
 771                 if (bindaddr != NULL && *bindaddr != '\0' &&
 772                     fetch_bind(sd, sa.ss_family, bindaddr) != 0)
 773                         goto sysouch;
 774                 if (connect(sd, (struct sockaddr *)&sa, sa.ss_len) == -1)
 775                         goto sysouch;
 776
 777                 /* make the server initiate the transfer */
 778                 if (verbose)
 779                         fetch_info("initiating transfer");
 780                 e = ftp_cmd(conn, "%s %.*s", oper, filenamelen, filename);
 781                 if (e != FTP_CONNECTION_ALREADY_OPEN && e != FTP_OPEN_DATA_CONNECTION)
 782                         goto ouch;
 783
 784         } else {
 785                 u_int32_t a;
 786                 u_short p;
 787                 int arg, d;
 788                 char *ap;
 789                 char hname[INET6_ADDRSTRLEN];
 790
 791                 switch (sa.ss_family) {
 792                 case AF_INET6:
 793                         ((struct sockaddr_in6 *)&sa)->sin6_port = 0;
 794 #ifdef IPV6_PORTRANGE
 795                         arg = low ? IPV6_PORTRANGE_DEFAULT : IPV6_PORTRANGE_HIGH;
 796                         if (setsockopt(sd, IPPROTO_IPV6, IPV6_PORTRANGE,
 797                                 (char *)&arg, sizeof(arg)) == -1)
 798                                 goto sysouch;
 799 #endif
 800                         break;
 801                 case AF_INET:
 802                         ((struct sockaddr_in *)&sa)->sin_port = 0;
 803                         arg = low ? IP_PORTRANGE_DEFAULT : IP_PORTRANGE_HIGH;
 804                         if (setsockopt(sd, IPPROTO_IP, IP_PORTRANGE,
 805                                 (char *)&arg, sizeof(arg)) == -1)
 806                                 goto sysouch;
 807                         break;
 808                 }
 809                 if (verbose)
 810                         fetch_info("binding data socket");
 811                 if (bind(sd, (struct sockaddr *)&sa, sa.ss_len) == -1)
 812                         goto sysouch;
 813                 if (listen(sd, 1) == -1)
 814                         goto sysouch;
 815
 816                 /* find what port we're on and tell the server */
 817                 if (getsockname(sd, (struct sockaddr *)&sa, &l) == -1)
 818                         goto sysouch;
 819                 switch (sa.ss_family) {
 820                 case AF_INET:
 821                         sin4 = (struct sockaddr_in *)&sa;
 822                         a = ntohl(sin4->sin_addr.s_addr);
 823                         p = ntohs(sin4->sin_port);
 824                         e = ftp_cmd(conn, "PORT %d,%d,%d,%d,%d,%d",
 825                             (a >> 24) & 0xff, (a >> 16) & 0xff,
 826                             (a >> 8) & 0xff, a & 0xff,
 827                             (p >> 8) & 0xff, p & 0xff);
 828                         break;
 829                 case AF_INET6:
 830 #define UC(b)   (((int)b)&0xff)
 831                         e = -1;
 832                         sin6 = (struct sockaddr_in6 *)&sa;
 833                         sin6->sin6_scope_id = 0;
 834                         if (getnameinfo((struct sockaddr *)&sa, sa.ss_len,
 835                                 hname, sizeof(hname),
 836                                 NULL, 0, NI_NUMERICHOST) == 0) {
 837                                 e = ftp_cmd(conn, "EPRT |%d|%s|%d|", 2, hname,
 838                                     htons(sin6->sin6_port));
 839                                 if (e == -1)
 840                                         goto ouch;
 841                         }
 842                         if (e != FTP_OK) {
 843                                 ap = (char *)&sin6->sin6_addr;
 844                                 e = ftp_cmd(conn,
 845                                     "LPRT %d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d,%d",
 846                                     6, 16,
 847                                     UC(ap[0]), UC(ap[1]), UC(ap[2]), UC(ap[3]),
 848                                     UC(ap[4]), UC(ap[5]), UC(ap[6]), UC(ap[7]),
 849                                     UC(ap[8]), UC(ap[9]), UC(ap[10]), UC(ap[11]),
 850                                     UC(ap[12]), UC(ap[13]), UC(ap[14]), UC(ap[15]),
 851                                     2,
 852                                     (ntohs(sin6->sin6_port) >> 8) & 0xff,
 853                                     ntohs(sin6->sin6_port)        & 0xff);
 854                         }
 855                         break;
 856                 default:
 857                         e = FTP_PROTOCOL_ERROR; /* XXX: error code should be prepared */
 858                         goto ouch;
 859                 }
 860                 if (e != FTP_OK)
 861                         goto ouch;
 862
 863                 /* seek to required offset */
 864                 if (offset)
 865                         if (ftp_cmd(conn, "REST %ju", (uintmax_t)offset) != FTP_FILE_OK)
 866                                 goto sysouch;
 867
 868                 /* make the server initiate the transfer */
 869                 if (verbose)
 870                         fetch_info("initiating transfer");
 871                 e = ftp_cmd(conn, "%s %.*s", oper, filenamelen, filename);
 872                 if (e != FTP_CONNECTION_ALREADY_OPEN && e != FTP_OPEN_DATA_CONNECTION)
 873                         goto ouch;
 874
 875                 /* accept the incoming connection and go to town */
 876                 if ((d = accept(sd, NULL, NULL)) == -1)
 877                         goto sysouch;
 878                 close(sd);
 879                 sd = d;
 880         }
 881
 882         if ((df = ftp_setup(conn, fetch_reopen(sd), mode)) == NULL)
 883                 goto sysouch;
 884         return (df);
 885
 886 sysouch:
 887         fetch_syserr();
 888         if (sd >= 0)
 889                 close(sd);
 890         return (NULL);
 891
 892 ouch:
 893         if (e != -1)
 894                 ftp_seterr(e);
 895         if (sd >= 0)
 896                 close(sd);
 897         return (NULL);
 898 }
 899
 900 /*
 901  * Authenticate
 902  */
 903 static int
 904 ftp_authenticate(conn_t *conn, struct url *url, struct url *purl)
 905 {
 906         const char *user, *pwd, *logname;
 907         char pbuf[MAXHOSTNAMELEN + MAXLOGNAME + 1];
 908         int e, len;
 909
 910         /* XXX FTP_AUTH, and maybe .netrc */
 911
 912         /* send user name and password */
 913         if (url->user[0] == '\0')
 914                 fetch_netrc_auth(url);
 915         user = url->user;
 916         if (*user == '\0')
 917                 user = getenv("FTP_LOGIN");
 918         if (user == NULL || *user == '\0')
 919                 user = FTP_ANONYMOUS_USER;
 920         if (purl && url->port == fetch_default_port(url->scheme))
 921                 e = ftp_cmd(conn, "USER %s@%s", user, url->host);
 922         else if (purl)
 923                 e = ftp_cmd(conn, "USER %s@%s@%d", user, url->host, url->port);
 924         else
 925                 e = ftp_cmd(conn, "USER %s", user);
 926
 927         /* did the server request a password? */
 928         if (e == FTP_NEED_PASSWORD) {
 929                 pwd = url->pwd;
 930                 if (*pwd == '\0')
 931                         pwd = getenv("FTP_PASSWORD");
 932                 if (pwd == NULL || *pwd == '\0') {
 933                         if ((logname = getlogin()) == 0)
 934                                 logname = FTP_ANONYMOUS_USER;
 935                         if ((len = snprintf(pbuf, MAXLOGNAME + 1, "%s@", logname)) < 0)
 936                                 len = 0;
 937                         else if (len > MAXLOGNAME)
 938                                 len = MAXLOGNAME;
 939                         gethostname(pbuf + len, sizeof(pbuf) - len);
 940                         pwd = pbuf;
 941                 }
 942                 e = ftp_cmd(conn, "PASS %s", pwd);
 943         }
 944
 945         return (e);
 946 }
 947
 948 /*
 949  * Log on to FTP server
 950  */
 951 static conn_t *
 952 ftp_connect(struct url *url, struct url *purl, const char *flags)
 953 {
 954         conn_t *conn;
 955         int e, direct, verbose;
 956 #ifdef INET6
 957         int af = AF_UNSPEC;
 958 #else
 959         int af = AF_INET;
 960 #endif
 961
 962         direct = CHECK_FLAG('d');
 963         verbose = CHECK_FLAG('v');
 964         if (CHECK_FLAG('4'))
 965                 af = AF_INET;
 966         else if (CHECK_FLAG('6'))
 967                 af = AF_INET6;
 968
 969         if (direct)
 970                 purl = NULL;
 971
 972         /* check for proxy */
 973         if (purl) {
 974                 /* XXX proxy authentication! */
 975                 conn = fetch_connect(purl->host, purl->port, af, verbose);
 976         } else {
 977                 /* no proxy, go straight to target */
 978                 conn = fetch_connect(url->host, url->port, af, verbose);
 979                 purl = NULL;
 980         }
 981
 982         /* check connection */
 983         if (conn == NULL)
 984                 /* fetch_connect() has already set an error code */
 985                 return (NULL);
 986
 987         /* expect welcome message */
 988         if ((e = ftp_chkerr(conn)) != FTP_SERVICE_READY)
 989                 goto fouch;
 990
 991         /* authenticate */
 992         if ((e = ftp_authenticate(conn, url, purl)) != FTP_LOGGED_IN)
 993                 goto fouch;
 994
 995         /* TODO: Request extended features supported, if any (RFC 3659). */
 996
 997         /* done */
 998         return (conn);
 999
1000 fouch:
1001         if (e != -1)
1002                 ftp_seterr(e);
1003         fetch_close(conn);
1004         return (NULL);
1005 }
1006
1007 /*
1008  * Disconnect from server
1009  */
1010 static void
1011 ftp_disconnect(conn_t *conn)
1012 {
1013         (void)ftp_cmd(conn, "QUIT");
1014         if (conn == cached_connection && conn->ref == 1)
1015                 cached_connection = NULL;
1016         fetch_close(conn);
1017 }
1018
1019 /*
1020  * Check if we're already connected
1021  */
1022 static int
1023 ftp_isconnected(struct url *url)
1024 {
1025         return (cached_connection
1026             && (strcmp(url->host, cached_host.host) == 0)
1027             && (strcmp(url->user, cached_host.user) == 0)
1028             && (strcmp(url->pwd, cached_host.pwd) == 0)
1029             && (url->port == cached_host.port));
1030 }
1031
1032 /*
1033  * Check the cache, reconnect if no luck
1034  */
1035 static conn_t *
1036 ftp_cached_connect(struct url *url, struct url *purl, const char *flags)
1037 {
1038         conn_t *conn;
1039         int e;
1040
1041         /* set default port */
1042         if (!url->port)
1043                 url->port = fetch_default_port(url->scheme);
1044
1045         /* try to use previously cached connection */
1046         if (ftp_isconnected(url)) {
1047                 e = ftp_cmd(cached_connection, "NOOP");
1048                 if (e == FTP_OK || e == FTP_SYNTAX_ERROR)
1049                         return (fetch_ref(cached_connection));
1050         }
1051
1052         /* connect to server */
1053         if ((conn = ftp_connect(url, purl, flags)) == NULL)
1054                 return (NULL);
1055         if (cached_connection)
1056                 ftp_disconnect(cached_connection);
1057         cached_connection = fetch_ref(conn);
1058         memcpy(&cached_host, url, sizeof(*url));
1059         return (conn);
1060 }
1061
1062 /*
1063  * Check the proxy settings
1064  */
1065 static struct url *
1066 ftp_get_proxy(struct url * url, const char *flags)
1067 {
1068         struct url *purl;
1069         char *p;
1070
1071         if (flags != NULL && strchr(flags, 'd') != NULL)
1072                 return (NULL);
1073         if (fetch_no_proxy_match(url->host))
1074                 return (NULL);
1075         if (((p = getenv("FTP_PROXY")) || (p = getenv("ftp_proxy")) ||
1076                 (p = getenv("HTTP_PROXY")) || (p = getenv("http_proxy"))) &&
1077             *p && (purl = fetchParseURL(p)) != NULL) {
1078                 if (!*purl->scheme) {
1079                         if (getenv("FTP_PROXY") || getenv("ftp_proxy"))
1080                                 strcpy(purl->scheme, SCHEME_FTP);
1081                         else
1082                                 strcpy(purl->scheme, SCHEME_HTTP);
1083                 }
1084                 if (!purl->port)
1085                         purl->port = fetch_default_proxy_port(purl->scheme);
1086                 if (strcasecmp(purl->scheme, SCHEME_FTP) == 0 ||
1087                     strcasecmp(purl->scheme, SCHEME_HTTP) == 0)
1088                         return (purl);
1089                 fetchFreeURL(purl);
1090         }
1091         return (NULL);
1092 }
1093
1094 /*
1095  * Process an FTP request
1096  */
1097 FILE *
1098 ftp_request(struct url *url, const char *op, struct url_stat *us,
1099     struct url *purl, const char *flags)
1100 {
1101         conn_t *conn;
1102         int oflag;
1103
1104         /* check if we should use HTTP instead */
1105         if (purl && strcasecmp(purl->scheme, SCHEME_HTTP) == 0) {
1106                 if (strcmp(op, "STAT") == 0)
1107                         return (http_request(url, "HEAD", us, purl, flags));
1108                 else if (strcmp(op, "RETR") == 0)
1109                         return (http_request(url, "GET", us, purl, flags));
1110                 /*
1111                  * Our HTTP code doesn't support PUT requests yet, so try
1112                  * a direct connection.
1113                  */
1114         }
1115
1116         /* connect to server */
1117         conn = ftp_cached_connect(url, purl, flags);
1118         if (purl)
1119                 fetchFreeURL(purl);
1120         if (conn == NULL)
1121                 return (NULL);
1122
1123         /* change directory */
1124         if (ftp_cwd(conn, url->doc) == -1)
1125                 return (NULL);
1126
1127         /* stat file */
1128         if (us && ftp_stat(conn, url->doc, us) == -1
1129             && fetchLastErrCode != FETCH_PROTO
1130             && fetchLastErrCode != FETCH_UNAVAIL)
1131                 return (NULL);
1132
1133         /* just a stat */
1134         if (strcmp(op, "STAT") == 0)
1135                 return (FILE *)1; /* bogus return value */
1136         if (strcmp(op, "STOR") == 0 || strcmp(op, "APPE") == 0)
1137                 oflag = O_WRONLY;
1138         else
1139                 oflag = O_RDONLY;
1140
1141         /* initiate the transfer */
1142         return (ftp_transfer(conn, op, url->doc, oflag, url->offset, flags));
1143 }
1144
1145 /*
1146  * Get and stat file
1147  */
1148 FILE *
1149 fetchXGetFTP(struct url *url, struct url_stat *us, const char *flags)
1150 {
1151         return (ftp_request(url, "RETR", us, ftp_get_proxy(url, flags), flags));
1152 }
1153
1154 /*
1155  * Get file
1156  */
1157 FILE *
1158 fetchGetFTP(struct url *url, const char *flags)
1159 {
1160         return (fetchXGetFTP(url, NULL, flags));
1161 }
1162
1163 /*
1164  * Put file
1165  */
1166 FILE *
1167 fetchPutFTP(struct url *url, const char *flags)
1168 {
1169         return (ftp_request(url, CHECK_FLAG('a') ? "APPE" : "STOR", NULL,
1170             ftp_get_proxy(url, flags), flags));
1171 }
1172
1173 /*
1174  * Get file stats
1175  */
1176 int
1177 fetchStatFTP(struct url *url, struct url_stat *us, const char *flags)
1178 {
1179         FILE *f;
1180
1181         f = ftp_request(url, "STAT", us, ftp_get_proxy(url, flags), flags);
1182         if (f == NULL)
1183                 return (-1);
1184         /*
1185          * When op is "STAT", ftp_request() will return either NULL or
1186          * (FILE *)1, never a valid FILE *, so we mustn't fclose(f) before
1187          * returning, as it would cause a segfault.
1188          */
1189         return (0);
1190 }
1191
1192 /*
1193  * List a directory
1194  */
1195 struct url_ent *
1196 fetchListFTP(struct url *url __unused, const char *flags __unused)
1197 {
1198         warnx("fetchListFTP(): not implemented");
1199         return (NULL);
1200 }