1 /* vi: set sw=4 ts=4: */
3 * Simple FTP daemon, based on vsftpd 2.0.7 (written by Chris Evans)
5 * Author: Adam Tkac <vonsch@gmail.com>
7 * Licensed under GPLv2, see file LICENSE in this tarball for details.
9 * Only subset of FTP protocol is implemented but vast majority of clients
10 * should not have any problem.
12 * You have to run this daemon via inetd.
17 #include <netinet/tcp.h>
19 #define FTP_DATACONN 150
20 #define FTP_NOOPOK 200
21 #define FTP_TYPEOK 200
22 #define FTP_PORTOK 200
23 #define FTP_STRUOK 200
24 #define FTP_MODEOK 200
25 #define FTP_ALLOOK 202
26 #define FTP_STATOK 211
27 #define FTP_STATFILE_OK 213
29 #define FTP_SYSTOK 215
31 #define FTP_GOODBYE 221
32 #define FTP_TRANSFEROK 226
33 #define FTP_PASVOK 227
34 /*#define FTP_EPRTOK 228*/
35 #define FTP_EPSVOK 229
36 #define FTP_LOGINOK 230
38 #define FTP_RMDIROK 250
39 #define FTP_DELEOK 250
40 #define FTP_RENAMEOK 250
42 #define FTP_MKDIROK 257
43 #define FTP_GIVEPWORD 331
44 #define FTP_RESTOK 350
45 #define FTP_RNFROK 350
46 #define FTP_TIMEOUT 421
47 #define FTP_BADSENDCONN 425
48 #define FTP_BADSENDNET 426
49 #define FTP_BADSENDFILE 451
50 #define FTP_BADCMD 500
51 #define FTP_COMMANDNOTIMPL 502
52 #define FTP_NEEDUSER 503
53 #define FTP_NEEDRNFR 503
54 #define FTP_BADSTRU 504
55 #define FTP_BADMODE 504
56 #define FTP_LOGINERR 530
57 #define FTP_FILEFAIL 550
58 #define FTP_NOPERM 550
59 #define FTP_UPLOADFAIL 553
62 #define STR(s) STR1(s)
64 /* Convert a constant to 3-digit string, packed into uint32_t */
66 /* Shift for Nth decimal digit */
67 SHIFT2 = 0 * BB_LITTLE_ENDIAN + 24 * BB_BIG_ENDIAN,
68 SHIFT1 = 8 * BB_LITTLE_ENDIAN + 16 * BB_BIG_ENDIAN,
69 SHIFT0 = 16 * BB_LITTLE_ENDIAN + 8 * BB_BIG_ENDIAN,
70 /* And for 4th position (space) */
71 SHIFTsp = 24 * BB_LITTLE_ENDIAN + 0 * BB_BIG_ENDIAN,
73 #define STRNUM32(s) (uint32_t)(0 \
74 | (('0' + ((s) / 1 % 10)) << SHIFT0) \
75 | (('0' + ((s) / 10 % 10)) << SHIFT1) \
76 | (('0' + ((s) / 100 % 10)) << SHIFT2) \
78 #define STRNUM32sp(s) (uint32_t)(0 \
80 | (('0' + ((s) / 1 % 10)) << SHIFT0) \
81 | (('0' + ((s) / 10 % 10)) << SHIFT1) \
82 | (('0' + ((s) / 100 % 10)) << SHIFT2) \
85 #define MSG_OK "Operation successful\r\n"
86 #define MSG_ERR "Error\r\n"
99 len_and_sockaddr *local_addr;
100 len_and_sockaddr *port_addr;
103 #if ENABLE_FEATURE_FTP_WRITE
106 /* We need these aligned to uint32_t */
107 char msg_ok [(sizeof("NNN " MSG_OK ) + 3) & 0xfffc];
108 char msg_err[(sizeof("NNN " MSG_ERR) + 3) & 0xfffc];
110 #define G (*(struct globals*)&bb_common_bufsiz1)
111 #define INIT_G() do { \
112 /* Moved to main */ \
113 /*strcpy(G.msg_ok + 4, MSG_OK );*/ \
114 /*strcpy(G.msg_err + 4, MSG_ERR);*/ \
119 escape_text(const char *prepend, const char *str, unsigned escapee)
121 unsigned retlen, remainlen, chunklen;
125 append = (char)escapee;
128 remainlen = strlen(str);
129 retlen = strlen(prepend);
130 ret = xmalloc(retlen + remainlen * 2 + 1 + 1);
131 strcpy(ret, prepend);
134 found = strchrnul(str, escapee);
135 chunklen = found - str + 1;
137 /* Copy chunk up to and including escapee (or NUL) to ret */
138 memcpy(ret + retlen, str, chunklen);
141 if (*found == '\0') {
142 /* It wasn't escapee, it was NUL! */
143 ret[retlen - 1] = append; /* replace NUL */
144 ret[retlen] = '\0'; /* add NUL */
147 ret[retlen++] = escapee; /* duplicate escapee */
153 /* Returns strlen as a bonus */
155 replace_char(char *str, char from, char to)
167 verbose_log(const char *str)
169 bb_error_msg("%.*s", (int)strcspn(str, "\r\n"), str);
172 /* NB: status_str is char[4] packed into uint32_t */
174 cmdio_write(uint32_t status_str, const char *str)
179 /* FTP uses telnet protocol for command link.
180 * In telnet, 0xff is an escape char, and needs to be escaped: */
181 response = escape_text((char *) &status_str, str, (0xff << 8) + '\r');
183 /* FTP sends embedded LFs as NULs */
184 len = replace_char(response, '\n', '\0');
186 response[len++] = '\n'; /* tack on trailing '\n' */
187 xwrite(STDOUT_FILENO, response, len);
189 verbose_log(response);
194 cmdio_write_ok(unsigned status)
196 *(uint32_t *) G.msg_ok = status;
197 xwrite(STDOUT_FILENO, G.msg_ok, sizeof("NNN " MSG_OK) - 1);
199 verbose_log(G.msg_ok);
201 #define WRITE_OK(a) cmdio_write_ok(STRNUM32sp(a))
203 /* TODO: output strerr(errno) if errno != 0? */
205 cmdio_write_error(unsigned status)
207 *(uint32_t *) G.msg_err = status;
208 xwrite(STDOUT_FILENO, G.msg_err, sizeof("NNN " MSG_ERR) - 1);
210 verbose_log(G.msg_err);
212 #define WRITE_ERR(a) cmdio_write_error(STRNUM32sp(a))
215 cmdio_write_raw(const char *p_text)
217 xwrite_str(STDOUT_FILENO, p_text);
223 timeout_handler(int sig UNUSED_PARAM)
226 int sv_errno = errno;
228 if ((int)(monotonic_sec() - G.end_time) >= 0)
231 if (!G.local_file_fd)
234 pos = xlseek(G.local_file_fd, 0, SEEK_CUR);
235 if (pos == G.local_file_pos)
237 G.local_file_pos = pos;
244 cmdio_write_raw(STR(FTP_TIMEOUT)" Timeout\r\n");
245 /* TODO: do we need to abort (as opposed to usual shutdown) data transfer? */
249 /* Simple commands */
254 char *cwd, *response;
256 cwd = xrealloc_getcwd_or_warn(NULL);
260 /* We have to promote each " to "" */
261 response = escape_text(" \"", cwd, ('"' << 8) + '"');
263 cmdio_write(STRNUM32(FTP_PWDOK), response);
270 if (!G.ftp_arg || chdir(G.ftp_arg) != 0) {
271 WRITE_ERR(FTP_FILEFAIL);
280 G.ftp_arg = (char*)"..";
287 cmdio_write_raw(STR(FTP_STATOK)"-Server status:\r\n"
289 STR(FTP_STATOK)" Ok\r\n");
292 /* Examples of HELP and FEAT:
293 # nc -vvv ftp.kernel.org 21
294 ftp.kernel.org (130.239.17.4:21) open
295 220 Welcome to ftp.kernel.org.
308 214-The following commands are recognized.
309 ABOR ACCT ALLO APPE CDUP CWD DELE EPRT EPSV FEAT HELP LIST MDTM MKD
310 MODE NLST NOOP OPTS PASS PASV PORT PWD QUIT REIN REST RETR RMD RNFR
311 RNTO SITE SIZE SMNT STAT STOR STOU STRU SYST TYPE USER XCUP XCWD XMKD
316 handle_feat(unsigned status)
318 cmdio_write(status, "-Features:");
319 cmdio_write_raw(" EPSV\r\n"
324 cmdio_write(status, " Ok");
327 /* Download commands */
332 return (G.port_addr != NULL);
338 return (G.pasv_listen_fd > STDOUT_FILENO);
342 port_pasv_cleanup(void)
346 if (G.pasv_listen_fd > STDOUT_FILENO)
347 close(G.pasv_listen_fd);
348 G.pasv_listen_fd = -1;
351 /* On error, emits error code to the peer */
353 ftpdataio_get_pasv_fd(void)
357 remote_fd = accept(G.pasv_listen_fd, NULL, 0);
360 WRITE_ERR(FTP_BADSENDCONN);
364 setsockopt(remote_fd, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1));
368 /* Clears port/pasv data.
369 * This means we dont waste resources, for example, keeping
370 * PASV listening socket open when it is no longer needed.
371 * On error, emits error code to the peer (or exits).
372 * On success, emits p_status_msg to the peer.
375 get_remote_transfer_fd(const char *p_status_msg)
380 /* On error, emits error code to the peer */
381 remote_fd = ftpdataio_get_pasv_fd();
384 remote_fd = xconnect_stream(G.port_addr);
391 cmdio_write(STRNUM32(FTP_DATACONN), p_status_msg);
395 /* If there were neither PASV nor PORT, emits error code to the peer */
397 port_or_pasv_was_seen(void)
399 if (!pasv_active() && !port_active()) {
400 cmdio_write_raw(STR(FTP_BADSENDCONN)" Use PORT/PASV first\r\n");
409 bind_for_passive_mode(void)
416 G.pasv_listen_fd = fd = xsocket(G.local_addr->u.sa.sa_family, SOCK_STREAM, 0);
417 setsockopt_reuseaddr(fd);
419 set_nport(G.local_addr, 0);
420 xbind(fd, &G.local_addr->u.sa, G.local_addr->len);
422 getsockname(fd, &G.local_addr->u.sa, &G.local_addr->len);
424 port = get_nport(&G.local_addr->u.sa);
434 char *addr, *response;
436 port = bind_for_passive_mode();
438 if (G.local_addr->u.sa.sa_family == AF_INET)
439 addr = xmalloc_sockaddr2dotted_noport(&G.local_addr->u.sa);
440 else /* seen this in the wild done by other ftp servers: */
441 addr = xstrdup("0.0.0.0");
442 replace_char(addr, '.', ',');
444 response = xasprintf(STR(FTP_PASVOK)" PASV ok (%s,%u,%u)\r\n",
445 addr, (int)(port >> 8), (int)(port & 255));
447 cmdio_write_raw(response);
458 port = bind_for_passive_mode();
459 response = xasprintf(STR(FTP_EPSVOK)" EPSV ok (|||%u|)\r\n", port);
460 cmdio_write_raw(response);
464 /* libbb candidate */
466 len_and_sockaddr* get_peer_lsa(int fd)
468 len_and_sockaddr *lsa;
471 if (getpeername(fd, NULL, &len) != 0)
473 lsa = xzalloc(LSA_LEN_SIZE + len);
475 getpeername(fd, &lsa->u.sa, &lsa->len);
482 unsigned port, port_hi;
484 #ifdef WHY_BOTHER_WE_CAN_ASSUME_IP_MATCHES
485 socklen_t peer_ipv4_len;
486 struct sockaddr_in peer_ipv4;
487 struct in_addr port_ipv4_sin_addr;
494 /* PORT command format makes sense only over IPv4 */
496 #ifdef WHY_BOTHER_WE_CAN_ASSUME_IP_MATCHES
497 || G.local_addr->u.sa.sa_family != AF_INET
501 WRITE_ERR(FTP_BADCMD);
505 comma = strrchr(raw, ',');
509 port = bb_strtou(&comma[1], NULL, 10);
510 if (errno || port > 0xff)
513 comma = strrchr(raw, ',');
517 port_hi = bb_strtou(&comma[1], NULL, 10);
518 if (errno || port_hi > 0xff)
520 port |= port_hi << 8;
522 #ifdef WHY_BOTHER_WE_CAN_ASSUME_IP_MATCHES
523 replace_char(raw, ',', '.');
525 /* We are verifying that PORT's IP matches getpeername().
526 * Otherwise peer can make us open data connections
527 * to other hosts (security problem!)
528 * This code would be too simplistic:
529 * lsa = xdotted2sockaddr(raw, port);
530 * if (lsa == NULL) goto bail;
532 if (!inet_aton(raw, &port_ipv4_sin_addr))
534 peer_ipv4_len = sizeof(peer_ipv4);
535 if (getpeername(STDIN_FILENO, &peer_ipv4, &peer_ipv4_len) != 0)
537 if (memcmp(&port_ipv4_sin_addr, &peer_ipv4.sin_addr, sizeof(struct in_addr)) != 0)
540 G.port_addr = xdotted2sockaddr(raw, port);
542 G.port_addr = get_peer_lsa(STDIN_FILENO);
543 set_nport(G.port_addr, htons(port));
545 WRITE_OK(FTP_PORTOK);
551 /* When ftp_arg == NULL simply restart from beginning */
552 G.restart_pos = G.ftp_arg ? xatoi_u(G.ftp_arg) : 0;
553 WRITE_OK(FTP_RESTOK);
560 off_t bytes_transferred;
563 off_t offset = G.restart_pos;
568 if (!port_or_pasv_was_seen())
569 return; /* port_or_pasv_was_seen emitted error response */
571 /* O_NONBLOCK is useful if file happens to be a device node */
572 local_file_fd = G.ftp_arg ? open(G.ftp_arg, O_RDONLY | O_NONBLOCK) : -1;
573 if (local_file_fd < 0) {
574 WRITE_ERR(FTP_FILEFAIL);
578 if (fstat(local_file_fd, &statbuf) != 0 || !S_ISREG(statbuf.st_mode)) {
579 /* Note - pretend open failed */
580 WRITE_ERR(FTP_FILEFAIL);
583 G.local_file_fd = local_file_fd;
585 /* Now deactive O_NONBLOCK, otherwise we have a problem
586 * on DMAPI filesystems such as XFS DMAPI.
588 ndelay_off(local_file_fd);
590 /* Set the download offset (from REST) if any */
592 xlseek(local_file_fd, offset, SEEK_SET);
594 response = xasprintf(
595 " Opening BINARY connection for %s (%"OFF_FMT"u bytes)",
596 G.ftp_arg, statbuf.st_size);
597 remote_fd = get_remote_transfer_fd(response);
602 bytes_transferred = bb_copyfd_eof(local_file_fd, remote_fd);
604 if (bytes_transferred < 0)
605 WRITE_ERR(FTP_BADSENDFILE);
607 WRITE_OK(FTP_TRANSFEROK);
610 close(local_file_fd);
617 popen_ls(const char *opt)
620 const char *argv[] = {
623 BB_MMU ? "--" : NULL,
627 struct fd_pair outfd;
630 cwd = xrealloc_getcwd_or_warn(NULL);
633 /*fflush(NULL); - so far we dont use stdio on output */
634 pid = BB_MMU ? fork() : vfork();
636 bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork");
641 if (fchdir(G.root_fd) != 0)
645 /* NB: close _first_, then move fd! */
647 xmove_fd(outfd.wr, STDOUT_FILENO);
648 /* Opening /dev/null in chroot is hard.
649 * Just making sure STDIN_FILENO is opened
650 * to something harmless. Paranoia,
651 * ls won't read it anyway */
653 dup(STDOUT_FILENO); /* copy will become STDIN_FILENO */
655 /* ftpd ls helper chdirs to argv[2],
656 * preventing peer from seeing real root we are in now
659 /* + 1: we must use relative path here if in chroot.
660 * For example, execv("/proc/self/exe") will fail, since
661 * it looks for "/proc/self/exe" _relative to chroot!_ */
662 execv(CONFIG_BUSYBOX_EXEC_PATH + 1, (char**) argv);
665 memset(&G, 0, sizeof(G));
666 exit(ls_main(ARRAY_SIZE(argv) - 1, (char**) argv));
682 handle_dir_common(int opts)
688 if (!(opts & USE_CTRL_CONN) && !port_or_pasv_was_seen())
689 return; /* port_or_pasv_was_seen emitted error response */
691 /* -n prevents user/groupname display,
692 * which can be problematic in chroot */
693 ls_fd = popen_ls((opts & LONG_LISTING) ? "-l" : "-1");
694 ls_fp = fdopen(ls_fd, "r");
695 if (!ls_fp) /* never happens. paranoia */
696 bb_perror_msg_and_die("fdopen");
698 if (opts & USE_CTRL_CONN) {
699 /* STAT <filename> */
700 cmdio_write_raw(STR(FTP_STATFILE_OK)"-File status:\r\n");
702 line = xmalloc_fgetline(ls_fp);
705 cmdio_write(0, line); /* hack: 0 results in no status at all */
708 WRITE_OK(FTP_STATFILE_OK);
710 /* LIST/NLST [<filename>] */
711 int remote_fd = get_remote_transfer_fd(" Directory listing");
712 if (remote_fd >= 0) {
714 line = xmalloc_fgetline(ls_fp);
717 /* I've seen clients complaining when they
718 * are fed with ls output with bare '\n'.
719 * Pity... that would be much simpler.
721 /* TODO: need to s/LF/NUL/g here */
722 xwrite_str(remote_fd, line);
723 xwrite(remote_fd, "\r\n", 2);
728 WRITE_OK(FTP_TRANSFEROK);
730 fclose(ls_fp); /* closes ls_fd too */
735 handle_dir_common(LONG_LISTING);
740 /* NLST returns list of names, "\r\n" terminated without regard
741 * to the current binary flag. Names may start with "/",
742 * then they represent full names (we don't produce such names),
743 * otherwise names are relative to current directory.
744 * Embedded "\n" are replaced by NULs. This is safe since names
745 * can never contain NUL.
747 handle_dir_common(0);
750 handle_stat_file(void)
752 handle_dir_common(LONG_LISTING + USE_CTRL_CONN);
755 /* This can be extended to handle MLST, as all info is available
756 * in struct stat for that:
758 * 250-Listing file_name
759 * type=file;size=4161;modify=19970214165800; /dir/dir/file_name
762 * MLST [<file or dir name, "." assumed if not given>]
763 * Returned name should be either the same as requested, or fully qualified.
764 * If there was no parameter, return "" or (preferred) fully-qualified name.
765 * Returned "facts" (case is not important):
766 * size - size in octets
767 * modify - last modification time
768 * type - entry type (file,dir,OS.unix=block)
769 * (+ cdir and pdir types for MLSD)
770 * unique - unique id of file/directory (inode#)
772 * a: can be appended to (APPE)
773 * d: can be deleted (RMD/DELE)
774 * f: can be renamed (RNFR)
775 * r: can be read (RETR)
776 * w: can be written (STOR)
777 * e: can CWD into this dir
778 * l: this dir can be listed (dir only!)
779 * c: can create files in this dir
780 * m: can create dirs in this dir (MKD)
781 * p: can delete files in this dir
782 * UNIX.mode - unix file mode
785 handle_size_or_mdtm(int need_size)
788 struct tm broken_out;
789 char buf[(sizeof("NNN %"OFF_FMT"u\r\n") + sizeof(off_t) * 3)
790 | sizeof("NNN YYYYMMDDhhmmss\r\n")
794 || stat(G.ftp_arg, &statbuf) != 0
795 || !S_ISREG(statbuf.st_mode)
797 WRITE_ERR(FTP_FILEFAIL);
801 sprintf(buf, STR(FTP_STATFILE_OK)" %"OFF_FMT"u\r\n", statbuf.st_size);
803 gmtime_r(&statbuf.st_mtime, &broken_out);
804 sprintf(buf, STR(FTP_STATFILE_OK)" %04u%02u%02u%02u%02u%02u\r\n",
805 broken_out.tm_year + 1900,
812 cmdio_write_raw(buf);
815 /* Upload commands */
817 #if ENABLE_FEATURE_FTP_WRITE
821 if (!G.ftp_arg || mkdir(G.ftp_arg, 0777) != 0) {
822 WRITE_ERR(FTP_FILEFAIL);
825 WRITE_OK(FTP_MKDIROK);
831 if (!G.ftp_arg || rmdir(G.ftp_arg) != 0) {
832 WRITE_ERR(FTP_FILEFAIL);
835 WRITE_OK(FTP_RMDIROK);
841 if (!G.ftp_arg || unlink(G.ftp_arg) != 0) {
842 WRITE_ERR(FTP_FILEFAIL);
845 WRITE_OK(FTP_DELEOK);
851 free(G.rnfr_filename);
852 G.rnfr_filename = xstrdup(G.ftp_arg);
853 WRITE_OK(FTP_RNFROK);
861 /* If we didn't get a RNFR, throw a wobbly */
862 if (G.rnfr_filename == NULL || G.ftp_arg == NULL) {
863 cmdio_write_raw(STR(FTP_NEEDRNFR)" Use RNFR first\r\n");
867 retval = rename(G.rnfr_filename, G.ftp_arg);
868 free(G.rnfr_filename);
869 G.rnfr_filename = NULL;
872 WRITE_ERR(FTP_FILEFAIL);
875 WRITE_OK(FTP_RENAMEOK);
879 handle_upload_common(int is_append, int is_unique)
883 off_t bytes_transferred;
888 offset = G.restart_pos;
891 if (!port_or_pasv_was_seen())
892 return; /* port_or_pasv_was_seen emitted error response */
897 tempname = xstrdup(" FILE: uniq.XXXXXX");
898 local_file_fd = mkstemp(tempname + 7);
899 } else if (G.ftp_arg) {
900 int flags = O_WRONLY | O_CREAT | O_TRUNC;
902 flags = O_WRONLY | O_CREAT | O_APPEND;
904 flags = O_WRONLY | O_CREAT;
905 local_file_fd = open(G.ftp_arg, flags, 0666);
908 if (local_file_fd < 0
909 || fstat(local_file_fd, &statbuf) != 0
910 || !S_ISREG(statbuf.st_mode)
912 WRITE_ERR(FTP_UPLOADFAIL);
913 if (local_file_fd >= 0)
914 goto close_local_and_bail;
917 G.local_file_fd = local_file_fd;
920 xlseek(local_file_fd, offset, SEEK_SET);
922 remote_fd = get_remote_transfer_fd(tempname ? tempname : " Ok to send data");
926 goto close_local_and_bail;
928 bytes_transferred = bb_copyfd_eof(remote_fd, local_file_fd);
930 if (bytes_transferred < 0)
931 WRITE_ERR(FTP_BADSENDFILE);
933 WRITE_OK(FTP_TRANSFEROK);
935 close_local_and_bail:
936 close(local_file_fd);
943 handle_upload_common(0, 0);
950 handle_upload_common(1, 0);
957 handle_upload_common(0, 1);
959 #endif /* ENABLE_FEATURE_FTP_WRITE */
962 cmdio_get_cmd_and_arg(void)
971 len = 8 * 1024; /* Paranoia. Peer may send 1 gigabyte long cmd... */
972 G.ftp_cmd = cmd = xmalloc_reads(STDIN_FILENO, NULL, &len);
976 /* Trailing '\n' is already stripped, strip '\r' */
977 len = strlen(cmd) - 1;
978 if ((ssize_t)len >= 0 && cmd[len] == '\r')
984 G.ftp_arg = strchr(cmd, ' ');
985 if (G.ftp_arg != NULL)
988 /* Uppercase and pack into uint32_t first word of the command */
991 cmdval = (cmdval << 8) + ((unsigned char)*cmd++ & (unsigned char)~0x20);
996 #define mk_const4(a,b,c,d) (((a * 0x100 + b) * 0x100 + c) * 0x100 + d)
997 #define mk_const3(a,b,c) ((a * 0x100 + b) * 0x100 + c)
999 const_ALLO = mk_const4('A', 'L', 'L', 'O'),
1000 const_APPE = mk_const4('A', 'P', 'P', 'E'),
1001 const_CDUP = mk_const4('C', 'D', 'U', 'P'),
1002 const_CWD = mk_const3('C', 'W', 'D'),
1003 const_DELE = mk_const4('D', 'E', 'L', 'E'),
1004 const_EPSV = mk_const4('E', 'P', 'S', 'V'),
1005 const_FEAT = mk_const4('F', 'E', 'A', 'T'),
1006 const_HELP = mk_const4('H', 'E', 'L', 'P'),
1007 const_LIST = mk_const4('L', 'I', 'S', 'T'),
1008 const_MDTM = mk_const4('M', 'D', 'T', 'M'),
1009 const_MKD = mk_const3('M', 'K', 'D'),
1010 const_MODE = mk_const4('M', 'O', 'D', 'E'),
1011 const_NLST = mk_const4('N', 'L', 'S', 'T'),
1012 const_NOOP = mk_const4('N', 'O', 'O', 'P'),
1013 const_PASS = mk_const4('P', 'A', 'S', 'S'),
1014 const_PASV = mk_const4('P', 'A', 'S', 'V'),
1015 const_PORT = mk_const4('P', 'O', 'R', 'T'),
1016 const_PWD = mk_const3('P', 'W', 'D'),
1017 const_QUIT = mk_const4('Q', 'U', 'I', 'T'),
1018 const_REST = mk_const4('R', 'E', 'S', 'T'),
1019 const_RETR = mk_const4('R', 'E', 'T', 'R'),
1020 const_RMD = mk_const3('R', 'M', 'D'),
1021 const_RNFR = mk_const4('R', 'N', 'F', 'R'),
1022 const_RNTO = mk_const4('R', 'N', 'T', 'O'),
1023 const_SIZE = mk_const4('S', 'I', 'Z', 'E'),
1024 const_STAT = mk_const4('S', 'T', 'A', 'T'),
1025 const_STOR = mk_const4('S', 'T', 'O', 'R'),
1026 const_STOU = mk_const4('S', 'T', 'O', 'U'),
1027 const_STRU = mk_const4('S', 'T', 'R', 'U'),
1028 const_SYST = mk_const4('S', 'Y', 'S', 'T'),
1029 const_TYPE = mk_const4('T', 'Y', 'P', 'E'),
1030 const_USER = mk_const4('U', 'S', 'E', 'R'),
1036 OPT_v = (1 << ((!BB_MMU) * 2 + 0)),
1037 OPT_S = (1 << ((!BB_MMU) * 2 + 1)),
1038 OPT_w = (1 << ((!BB_MMU) * 2 + 2)) * ENABLE_FEATURE_FTP_WRITE,
1041 int ftpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1043 int ftpd_main(int argc, char **argv)
1045 int ftpd_main(int argc UNUSED_PARAM, char **argv)
1048 unsigned abs_timeout;
1053 abs_timeout = 1 * 60 * 60;
1055 opt_complementary = "t+:T+:vv";
1057 opts = getopt32(argv, "vS" USE_FEATURE_FTP_WRITE("w") "t:T:", &G.timeout, &abs_timeout, &G.verbose);
1059 opts = getopt32(argv, "l1vS" USE_FEATURE_FTP_WRITE("w") "t:T:", &G.timeout, &abs_timeout, &G.verbose);
1060 if (opts & (OPT_l|OPT_1)) {
1061 /* Our secret backdoor to ls */
1062 /* TODO: pass -n too? */
1063 /* --group-directories-first would be nice, but ls don't do that yet */
1065 argv[2] = (char*)"--";
1066 memset(&G, 0, sizeof(G));
1067 return ls_main(argc, argv);
1070 if (abs_timeout | G.timeout) {
1071 if (abs_timeout == 0)
1072 abs_timeout = INT_MAX;
1073 G.end_time = monotonic_sec() + abs_timeout;
1074 if (G.timeout > abs_timeout)
1075 G.timeout = abs_timeout;
1077 strcpy(G.msg_ok + 4, MSG_OK );
1078 strcpy(G.msg_err + 4, MSG_ERR);
1080 G.local_addr = get_sock_lsa(STDIN_FILENO);
1081 if (!G.local_addr) {
1082 /* This is confusing:
1083 * bb_error_msg_and_die("stdin is not a socket");
1086 /* Help text says that ftpd must be used as inetd service,
1087 * which is by far the most usual cause of get_sock_lsa
1091 if (!(opts & OPT_v))
1092 logmode = LOGMODE_NONE;
1094 /* LOG_NDELAY is needed since we may chroot later */
1095 openlog(applet_name, LOG_PID | LOG_NDELAY, LOG_DAEMON);
1096 logmode |= LOGMODE_SYSLOG;
1099 applet_name = xasprintf("%s[%u]", applet_name, (int)getpid());
1102 G.root_fd = xopen("/", O_RDONLY | O_DIRECTORY);
1106 xchdir(argv[optind]);
1110 //umask(077); - admin can set umask before starting us
1112 /* Signals. We'll always take -EPIPE rather than a rude signal, thanks */
1113 signal(SIGPIPE, SIG_IGN);
1115 /* Set up options on the command socket (do we need these all? why?) */
1116 setsockopt(STDIN_FILENO, IPPROTO_TCP, TCP_NODELAY, &const_int_1, sizeof(const_int_1));
1117 setsockopt(STDIN_FILENO, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1));
1118 setsockopt(STDIN_FILENO, SOL_SOCKET, SO_OOBINLINE, &const_int_1, sizeof(const_int_1));
1120 WRITE_OK(FTP_GREET);
1121 signal(SIGALRM, timeout_handler);
1123 #ifdef IF_WE_WANT_TO_REQUIRE_LOGIN
1125 smallint user_was_specified = 0;
1127 uint32_t cmdval = cmdio_get_cmd_and_arg();
1129 if (cmdval == const_USER) {
1130 if (G.ftp_arg == NULL || strcasecmp(G.ftp_arg, "anonymous") != 0)
1131 cmdio_write_raw(STR(FTP_LOGINERR)" Server is anonymous only\r\n");
1133 user_was_specified = 1;
1134 cmdio_write_raw(STR(FTP_GIVEPWORD)" Please specify the password\r\n");
1136 } else if (cmdval == const_PASS) {
1137 if (user_was_specified)
1139 cmdio_write_raw(STR(FTP_NEEDUSER)" Login with USER\r\n");
1140 } else if (cmdval == const_QUIT) {
1141 WRITE_OK(FTP_GOODBYE);
1144 cmdio_write_raw(STR(FTP_LOGINERR)" Login with USER and PASS\r\n");
1148 WRITE_OK(FTP_LOGINOK);
1151 /* RFC-959 Section 5.1
1152 * The following commands and options MUST be supported by every
1153 * server-FTP and user-FTP, except in cases where the underlying
1154 * file system or operating system does not allow or support
1155 * a particular command.
1156 * Type: ASCII Non-print, IMAGE, LOCAL 8
1158 * Structure: File, Record*
1159 * (Record structure is REQUIRED only for hosts whose file
1160 * systems support record structure).
1162 * USER, PASS, ACCT, [bbox: ACCT not supported]
1167 * CWD, CDUP, RMD, MKD, PWD,
1173 * "The argument field is a Telnet string identifying the user's account.
1174 * The command is not necessarily related to the USER command, as some
1175 * sites may require an account for login and others only for specific
1176 * access, such as storing files. In the latter case the command may
1177 * arrive at any time.
1178 * There are reply codes to differentiate these cases for the automation:
1179 * when account information is required for login, the response to
1180 * a successful PASSword command is reply code 332. On the other hand,
1181 * if account information is NOT required for login, the reply to
1182 * a successful PASSword command is 230; and if the account information
1183 * is needed for a command issued later in the dialogue, the server
1184 * should return a 332 or 532 reply depending on whether it stores
1185 * (pending receipt of the ACCounT command) or discards the command,
1190 uint32_t cmdval = cmdio_get_cmd_and_arg();
1192 if (cmdval == const_QUIT) {
1193 WRITE_OK(FTP_GOODBYE);
1196 else if (cmdval == const_USER)
1197 /* This would mean "ok, now give me PASS". */
1198 /*WRITE_OK(FTP_GIVEPWORD);*/
1199 /* vsftpd can be configured to not require that,
1200 * and this also saves one roundtrip:
1202 WRITE_OK(FTP_LOGINOK);
1203 else if (cmdval == const_PASS)
1204 WRITE_OK(FTP_LOGINOK);
1205 else if (cmdval == const_NOOP)
1206 WRITE_OK(FTP_NOOPOK);
1207 else if (cmdval == const_TYPE)
1208 WRITE_OK(FTP_TYPEOK);
1209 else if (cmdval == const_STRU)
1210 WRITE_OK(FTP_STRUOK);
1211 else if (cmdval == const_MODE)
1212 WRITE_OK(FTP_MODEOK);
1213 else if (cmdval == const_ALLO)
1214 WRITE_OK(FTP_ALLOOK);
1215 else if (cmdval == const_SYST)
1216 cmdio_write_raw(STR(FTP_SYSTOK)" UNIX Type: L8\r\n");
1217 else if (cmdval == const_PWD)
1219 else if (cmdval == const_CWD)
1221 else if (cmdval == const_CDUP) /* cd .. */
1223 /* HELP is nearly useless, but we can reuse FEAT for it */
1224 /* lftp uses FEAT */
1225 else if (cmdval == const_HELP || cmdval == const_FEAT)
1226 handle_feat(cmdval == const_HELP
1227 ? STRNUM32(FTP_HELP)
1228 : STRNUM32(FTP_STATOK)
1230 else if (cmdval == const_LIST) /* ls -l */
1232 else if (cmdval == const_NLST) /* "name list", bare ls */
1234 /* SIZE is crucial for wget's download indicator etc */
1235 /* Mozilla, lftp use MDTM (presumably for caching) */
1236 else if (cmdval == const_SIZE || cmdval == const_MDTM)
1237 handle_size_or_mdtm(cmdval == const_SIZE);
1238 else if (cmdval == const_STAT) {
1239 if (G.ftp_arg == NULL)
1244 else if (cmdval == const_PASV)
1246 else if (cmdval == const_EPSV)
1248 else if (cmdval == const_RETR)
1250 else if (cmdval == const_PORT)
1252 else if (cmdval == const_REST)
1254 #if ENABLE_FEATURE_FTP_WRITE
1255 else if (opts & OPT_w) {
1256 if (cmdval == const_STOR)
1258 else if (cmdval == const_MKD)
1260 else if (cmdval == const_RMD)
1262 else if (cmdval == const_DELE)
1264 else if (cmdval == const_RNFR) /* "rename from" */
1266 else if (cmdval == const_RNTO) /* "rename to" */
1268 else if (cmdval == const_APPE)
1270 else if (cmdval == const_STOU) /* "store unique" */
1275 else if (cmdval == const_STOR
1276 || cmdval == const_MKD
1277 || cmdval == const_RMD
1278 || cmdval == const_DELE
1279 || cmdval == const_RNFR
1280 || cmdval == const_RNTO
1281 || cmdval == const_APPE
1282 || cmdval == const_STOU
1284 cmdio_write_raw(STR(FTP_NOPERM)" Permission denied\r\n");
1288 /* Which unsupported commands were seen in the wild?
1289 * (doesn't necessarily mean "we must support them")
1290 * foo 1.2.3: XXXX - comment
1292 cmdio_write_raw(STR(FTP_BADCMD)" Unknown command\r\n");