Contents of /trunk/mkinitrd-magellan/busybox/networking/ftpd.c
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Revision 984 -
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Sun May 30 11:32:42 2010 UTC (14 years, 4 months ago) by niro
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File size: 34638 byte(s)
Sun May 30 11:32:42 2010 UTC (14 years, 4 months ago) by niro
File MIME type: text/plain
File size: 34638 byte(s)
-updated to busybox-1.16.1 and enabled blkid/uuid support in default config
1 | /* vi: set sw=4 ts=4: */ |
2 | /* |
3 | * Simple FTP daemon, based on vsftpd 2.0.7 (written by Chris Evans) |
4 | * |
5 | * Author: Adam Tkac <vonsch@gmail.com> |
6 | * |
7 | * Licensed under GPLv2, see file LICENSE in this tarball for details. |
8 | * |
9 | * Only subset of FTP protocol is implemented but vast majority of clients |
10 | * should not have any problem. |
11 | * |
12 | * You have to run this daemon via inetd. |
13 | */ |
14 | |
15 | #include "libbb.h" |
16 | #include <syslog.h> |
17 | #include <netinet/tcp.h> |
18 | |
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 |
28 | #define FTP_HELP 214 |
29 | #define FTP_SYSTOK 215 |
30 | #define FTP_GREET 220 |
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 |
37 | #define FTP_CWDOK 250 |
38 | #define FTP_RMDIROK 250 |
39 | #define FTP_DELEOK 250 |
40 | #define FTP_RENAMEOK 250 |
41 | #define FTP_PWDOK 257 |
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 |
60 | |
61 | #define STR1(s) #s |
62 | #define STR(s) STR1(s) |
63 | |
64 | /* Convert a constant to 3-digit string, packed into uint32_t */ |
65 | enum { |
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, |
72 | }; |
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) \ |
77 | ) |
78 | #define STRNUM32sp(s) (uint32_t)(0 \ |
79 | | (' ' << SHIFTsp) \ |
80 | | (('0' + ((s) / 1 % 10)) << SHIFT0) \ |
81 | | (('0' + ((s) / 10 % 10)) << SHIFT1) \ |
82 | | (('0' + ((s) / 100 % 10)) << SHIFT2) \ |
83 | ) |
84 | |
85 | #define MSG_OK "Operation successful\r\n" |
86 | #define MSG_ERR "Error\r\n" |
87 | |
88 | struct globals { |
89 | int pasv_listen_fd; |
90 | #if !BB_MMU |
91 | int root_fd; |
92 | #endif |
93 | int local_file_fd; |
94 | unsigned end_time; |
95 | unsigned timeout; |
96 | unsigned verbose; |
97 | off_t local_file_pos; |
98 | off_t restart_pos; |
99 | len_and_sockaddr *local_addr; |
100 | len_and_sockaddr *port_addr; |
101 | char *ftp_cmd; |
102 | char *ftp_arg; |
103 | #if ENABLE_FEATURE_FTP_WRITE |
104 | char *rnfr_filename; |
105 | #endif |
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]; |
109 | }; |
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);*/ \ |
115 | } while (0) |
116 | |
117 | |
118 | static char * |
119 | escape_text(const char *prepend, const char *str, unsigned escapee) |
120 | { |
121 | unsigned retlen, remainlen, chunklen; |
122 | char *ret, *found; |
123 | char append; |
124 | |
125 | append = (char)escapee; |
126 | escapee >>= 8; |
127 | |
128 | remainlen = strlen(str); |
129 | retlen = strlen(prepend); |
130 | ret = xmalloc(retlen + remainlen * 2 + 1 + 1); |
131 | strcpy(ret, prepend); |
132 | |
133 | for (;;) { |
134 | found = strchrnul(str, escapee); |
135 | chunklen = found - str + 1; |
136 | |
137 | /* Copy chunk up to and including escapee (or NUL) to ret */ |
138 | memcpy(ret + retlen, str, chunklen); |
139 | retlen += chunklen; |
140 | |
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 */ |
145 | break; |
146 | } |
147 | ret[retlen++] = escapee; /* duplicate escapee */ |
148 | str = found + 1; |
149 | } |
150 | return ret; |
151 | } |
152 | |
153 | /* Returns strlen as a bonus */ |
154 | static unsigned |
155 | replace_char(char *str, char from, char to) |
156 | { |
157 | char *p = str; |
158 | while (*p) { |
159 | if (*p == from) |
160 | *p = to; |
161 | p++; |
162 | } |
163 | return p - str; |
164 | } |
165 | |
166 | static void |
167 | verbose_log(const char *str) |
168 | { |
169 | bb_error_msg("%.*s", (int)strcspn(str, "\r\n"), str); |
170 | } |
171 | |
172 | /* NB: status_str is char[4] packed into uint32_t */ |
173 | static void |
174 | cmdio_write(uint32_t status_str, const char *str) |
175 | { |
176 | char *response; |
177 | int len; |
178 | |
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'); |
182 | |
183 | /* FTP sends embedded LFs as NULs */ |
184 | len = replace_char(response, '\n', '\0'); |
185 | |
186 | response[len++] = '\n'; /* tack on trailing '\n' */ |
187 | xwrite(STDOUT_FILENO, response, len); |
188 | if (G.verbose > 1) |
189 | verbose_log(response); |
190 | free(response); |
191 | } |
192 | |
193 | static void |
194 | cmdio_write_ok(unsigned status) |
195 | { |
196 | *(uint32_t *) G.msg_ok = status; |
197 | xwrite(STDOUT_FILENO, G.msg_ok, sizeof("NNN " MSG_OK) - 1); |
198 | if (G.verbose > 1) |
199 | verbose_log(G.msg_ok); |
200 | } |
201 | #define WRITE_OK(a) cmdio_write_ok(STRNUM32sp(a)) |
202 | |
203 | /* TODO: output strerr(errno) if errno != 0? */ |
204 | static void |
205 | cmdio_write_error(unsigned status) |
206 | { |
207 | *(uint32_t *) G.msg_err = status; |
208 | xwrite(STDOUT_FILENO, G.msg_err, sizeof("NNN " MSG_ERR) - 1); |
209 | if (G.verbose > 1) |
210 | verbose_log(G.msg_err); |
211 | } |
212 | #define WRITE_ERR(a) cmdio_write_error(STRNUM32sp(a)) |
213 | |
214 | static void |
215 | cmdio_write_raw(const char *p_text) |
216 | { |
217 | xwrite_str(STDOUT_FILENO, p_text); |
218 | if (G.verbose > 1) |
219 | verbose_log(p_text); |
220 | } |
221 | |
222 | static void |
223 | timeout_handler(int sig UNUSED_PARAM) |
224 | { |
225 | off_t pos; |
226 | int sv_errno = errno; |
227 | |
228 | if ((int)(monotonic_sec() - G.end_time) >= 0) |
229 | goto timed_out; |
230 | |
231 | if (!G.local_file_fd) |
232 | goto timed_out; |
233 | |
234 | pos = xlseek(G.local_file_fd, 0, SEEK_CUR); |
235 | if (pos == G.local_file_pos) |
236 | goto timed_out; |
237 | G.local_file_pos = pos; |
238 | |
239 | alarm(G.timeout); |
240 | errno = sv_errno; |
241 | return; |
242 | |
243 | timed_out: |
244 | cmdio_write_raw(STR(FTP_TIMEOUT)" Timeout\r\n"); |
245 | /* TODO: do we need to abort (as opposed to usual shutdown) data transfer? */ |
246 | exit(1); |
247 | } |
248 | |
249 | /* Simple commands */ |
250 | |
251 | static void |
252 | handle_pwd(void) |
253 | { |
254 | char *cwd, *response; |
255 | |
256 | cwd = xrealloc_getcwd_or_warn(NULL); |
257 | if (cwd == NULL) |
258 | cwd = xstrdup(""); |
259 | |
260 | /* We have to promote each " to "" */ |
261 | response = escape_text(" \"", cwd, ('"' << 8) + '"'); |
262 | free(cwd); |
263 | cmdio_write(STRNUM32(FTP_PWDOK), response); |
264 | free(response); |
265 | } |
266 | |
267 | static void |
268 | handle_cwd(void) |
269 | { |
270 | if (!G.ftp_arg || chdir(G.ftp_arg) != 0) { |
271 | WRITE_ERR(FTP_FILEFAIL); |
272 | return; |
273 | } |
274 | WRITE_OK(FTP_CWDOK); |
275 | } |
276 | |
277 | static void |
278 | handle_cdup(void) |
279 | { |
280 | G.ftp_arg = (char*)".."; |
281 | handle_cwd(); |
282 | } |
283 | |
284 | static void |
285 | handle_stat(void) |
286 | { |
287 | cmdio_write_raw(STR(FTP_STATOK)"-Server status:\r\n" |
288 | " TYPE: BINARY\r\n" |
289 | STR(FTP_STATOK)" Ok\r\n"); |
290 | } |
291 | |
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. |
296 | FEAT |
297 | 211-Features: |
298 | EPRT |
299 | EPSV |
300 | MDTM |
301 | PASV |
302 | REST STREAM |
303 | SIZE |
304 | TVFS |
305 | UTF8 |
306 | 211 End |
307 | HELP |
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 |
312 | XPWD XRMD |
313 | 214 Help OK. |
314 | */ |
315 | static void |
316 | handle_feat(unsigned status) |
317 | { |
318 | cmdio_write(status, "-Features:"); |
319 | cmdio_write_raw(" EPSV\r\n" |
320 | " PASV\r\n" |
321 | " REST STREAM\r\n" |
322 | " MDTM\r\n" |
323 | " SIZE\r\n"); |
324 | cmdio_write(status, " Ok"); |
325 | } |
326 | |
327 | /* Download commands */ |
328 | |
329 | static inline int |
330 | port_active(void) |
331 | { |
332 | return (G.port_addr != NULL); |
333 | } |
334 | |
335 | static inline int |
336 | pasv_active(void) |
337 | { |
338 | return (G.pasv_listen_fd > STDOUT_FILENO); |
339 | } |
340 | |
341 | static void |
342 | port_pasv_cleanup(void) |
343 | { |
344 | free(G.port_addr); |
345 | G.port_addr = NULL; |
346 | if (G.pasv_listen_fd > STDOUT_FILENO) |
347 | close(G.pasv_listen_fd); |
348 | G.pasv_listen_fd = -1; |
349 | } |
350 | |
351 | /* On error, emits error code to the peer */ |
352 | static int |
353 | ftpdataio_get_pasv_fd(void) |
354 | { |
355 | int remote_fd; |
356 | |
357 | remote_fd = accept(G.pasv_listen_fd, NULL, 0); |
358 | |
359 | if (remote_fd < 0) { |
360 | WRITE_ERR(FTP_BADSENDCONN); |
361 | return remote_fd; |
362 | } |
363 | |
364 | setsockopt(remote_fd, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1)); |
365 | return remote_fd; |
366 | } |
367 | |
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. |
373 | */ |
374 | static int |
375 | get_remote_transfer_fd(const char *p_status_msg) |
376 | { |
377 | int remote_fd; |
378 | |
379 | if (pasv_active()) |
380 | /* On error, emits error code to the peer */ |
381 | remote_fd = ftpdataio_get_pasv_fd(); |
382 | else |
383 | /* Exits on error */ |
384 | remote_fd = xconnect_stream(G.port_addr); |
385 | |
386 | port_pasv_cleanup(); |
387 | |
388 | if (remote_fd < 0) |
389 | return remote_fd; |
390 | |
391 | cmdio_write(STRNUM32(FTP_DATACONN), p_status_msg); |
392 | return remote_fd; |
393 | } |
394 | |
395 | /* If there were neither PASV nor PORT, emits error code to the peer */ |
396 | static int |
397 | port_or_pasv_was_seen(void) |
398 | { |
399 | if (!pasv_active() && !port_active()) { |
400 | cmdio_write_raw(STR(FTP_BADSENDCONN)" Use PORT/PASV first\r\n"); |
401 | return 0; |
402 | } |
403 | |
404 | return 1; |
405 | } |
406 | |
407 | /* Exits on error */ |
408 | static unsigned |
409 | bind_for_passive_mode(void) |
410 | { |
411 | int fd; |
412 | unsigned port; |
413 | |
414 | port_pasv_cleanup(); |
415 | |
416 | G.pasv_listen_fd = fd = xsocket(G.local_addr->u.sa.sa_family, SOCK_STREAM, 0); |
417 | setsockopt_reuseaddr(fd); |
418 | |
419 | set_nport(G.local_addr, 0); |
420 | xbind(fd, &G.local_addr->u.sa, G.local_addr->len); |
421 | xlisten(fd, 1); |
422 | getsockname(fd, &G.local_addr->u.sa, &G.local_addr->len); |
423 | |
424 | port = get_nport(&G.local_addr->u.sa); |
425 | port = ntohs(port); |
426 | return port; |
427 | } |
428 | |
429 | /* Exits on error */ |
430 | static void |
431 | handle_pasv(void) |
432 | { |
433 | unsigned port; |
434 | char *addr, *response; |
435 | |
436 | port = bind_for_passive_mode(); |
437 | |
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, '.', ','); |
443 | |
444 | response = xasprintf(STR(FTP_PASVOK)" PASV ok (%s,%u,%u)\r\n", |
445 | addr, (int)(port >> 8), (int)(port & 255)); |
446 | free(addr); |
447 | cmdio_write_raw(response); |
448 | free(response); |
449 | } |
450 | |
451 | /* Exits on error */ |
452 | static void |
453 | handle_epsv(void) |
454 | { |
455 | unsigned port; |
456 | char *response; |
457 | |
458 | port = bind_for_passive_mode(); |
459 | response = xasprintf(STR(FTP_EPSVOK)" EPSV ok (|||%u|)\r\n", port); |
460 | cmdio_write_raw(response); |
461 | free(response); |
462 | } |
463 | |
464 | /* libbb candidate */ |
465 | static |
466 | len_and_sockaddr* get_peer_lsa(int fd) |
467 | { |
468 | len_and_sockaddr *lsa; |
469 | socklen_t len = 0; |
470 | |
471 | if (getpeername(fd, NULL, &len) != 0) |
472 | return NULL; |
473 | lsa = xzalloc(LSA_LEN_SIZE + len); |
474 | lsa->len = len; |
475 | getpeername(fd, &lsa->u.sa, &lsa->len); |
476 | return lsa; |
477 | } |
478 | |
479 | static void |
480 | handle_port(void) |
481 | { |
482 | unsigned port, port_hi; |
483 | char *raw, *comma; |
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; |
488 | #endif |
489 | |
490 | port_pasv_cleanup(); |
491 | |
492 | raw = G.ftp_arg; |
493 | |
494 | /* PORT command format makes sense only over IPv4 */ |
495 | if (!raw |
496 | #ifdef WHY_BOTHER_WE_CAN_ASSUME_IP_MATCHES |
497 | || G.local_addr->u.sa.sa_family != AF_INET |
498 | #endif |
499 | ) { |
500 | bail: |
501 | WRITE_ERR(FTP_BADCMD); |
502 | return; |
503 | } |
504 | |
505 | comma = strrchr(raw, ','); |
506 | if (comma == NULL) |
507 | goto bail; |
508 | *comma = '\0'; |
509 | port = bb_strtou(&comma[1], NULL, 10); |
510 | if (errno || port > 0xff) |
511 | goto bail; |
512 | |
513 | comma = strrchr(raw, ','); |
514 | if (comma == NULL) |
515 | goto bail; |
516 | *comma = '\0'; |
517 | port_hi = bb_strtou(&comma[1], NULL, 10); |
518 | if (errno || port_hi > 0xff) |
519 | goto bail; |
520 | port |= port_hi << 8; |
521 | |
522 | #ifdef WHY_BOTHER_WE_CAN_ASSUME_IP_MATCHES |
523 | replace_char(raw, ',', '.'); |
524 | |
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; |
531 | */ |
532 | if (!inet_aton(raw, &port_ipv4_sin_addr)) |
533 | goto bail; |
534 | peer_ipv4_len = sizeof(peer_ipv4); |
535 | if (getpeername(STDIN_FILENO, &peer_ipv4, &peer_ipv4_len) != 0) |
536 | goto bail; |
537 | if (memcmp(&port_ipv4_sin_addr, &peer_ipv4.sin_addr, sizeof(struct in_addr)) != 0) |
538 | goto bail; |
539 | |
540 | G.port_addr = xdotted2sockaddr(raw, port); |
541 | #else |
542 | G.port_addr = get_peer_lsa(STDIN_FILENO); |
543 | set_nport(G.port_addr, htons(port)); |
544 | #endif |
545 | WRITE_OK(FTP_PORTOK); |
546 | } |
547 | |
548 | static void |
549 | handle_rest(void) |
550 | { |
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); |
554 | } |
555 | |
556 | static void |
557 | handle_retr(void) |
558 | { |
559 | struct stat statbuf; |
560 | off_t bytes_transferred; |
561 | int remote_fd; |
562 | int local_file_fd; |
563 | off_t offset = G.restart_pos; |
564 | char *response; |
565 | |
566 | G.restart_pos = 0; |
567 | |
568 | if (!port_or_pasv_was_seen()) |
569 | return; /* port_or_pasv_was_seen emitted error response */ |
570 | |
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); |
575 | return; |
576 | } |
577 | |
578 | if (fstat(local_file_fd, &statbuf) != 0 || !S_ISREG(statbuf.st_mode)) { |
579 | /* Note - pretend open failed */ |
580 | WRITE_ERR(FTP_FILEFAIL); |
581 | goto file_close_out; |
582 | } |
583 | G.local_file_fd = local_file_fd; |
584 | |
585 | /* Now deactive O_NONBLOCK, otherwise we have a problem |
586 | * on DMAPI filesystems such as XFS DMAPI. |
587 | */ |
588 | ndelay_off(local_file_fd); |
589 | |
590 | /* Set the download offset (from REST) if any */ |
591 | if (offset != 0) |
592 | xlseek(local_file_fd, offset, SEEK_SET); |
593 | |
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); |
598 | free(response); |
599 | if (remote_fd < 0) |
600 | goto file_close_out; |
601 | |
602 | bytes_transferred = bb_copyfd_eof(local_file_fd, remote_fd); |
603 | close(remote_fd); |
604 | if (bytes_transferred < 0) |
605 | WRITE_ERR(FTP_BADSENDFILE); |
606 | else |
607 | WRITE_OK(FTP_TRANSFEROK); |
608 | |
609 | file_close_out: |
610 | close(local_file_fd); |
611 | G.local_file_fd = 0; |
612 | } |
613 | |
614 | /* List commands */ |
615 | |
616 | static int |
617 | popen_ls(const char *opt) |
618 | { |
619 | const char *argv[5]; |
620 | struct fd_pair outfd; |
621 | pid_t pid; |
622 | |
623 | argv[0] = "ftpd"; |
624 | argv[1] = opt; /* "-l" or "-1" */ |
625 | #if BB_MMU |
626 | argv[2] = "--"; |
627 | #else |
628 | /* NOMMU ftpd ls helper chdirs to argv[2], |
629 | * preventing peer from seeing real root. */ |
630 | argv[2] = xrealloc_getcwd_or_warn(NULL); |
631 | #endif |
632 | argv[3] = G.ftp_arg; |
633 | argv[4] = NULL; |
634 | |
635 | /* Improve compatibility with non-RFC conforming FTP clients |
636 | * which send e.g. "LIST -l", "LIST -la". |
637 | * See https://bugs.kde.org/show_bug.cgi?id=195578 */ |
638 | if (ENABLE_FEATURE_FTPD_ACCEPT_BROKEN_LIST |
639 | && G.ftp_arg && G.ftp_arg[0] == '-' && G.ftp_arg[1] == 'l' |
640 | ) { |
641 | const char *tmp = strchr(G.ftp_arg, ' '); |
642 | if (tmp) /* skip the space */ |
643 | tmp++; |
644 | argv[3] = tmp; |
645 | } |
646 | |
647 | xpiped_pair(outfd); |
648 | |
649 | /*fflush_all(); - so far we dont use stdio on output */ |
650 | pid = BB_MMU ? fork() : vfork(); |
651 | if (pid < 0) |
652 | bb_perror_msg_and_die(BB_MMU ? "fork" : "vfork"); |
653 | |
654 | if (pid == 0) { |
655 | /* child */ |
656 | #if !BB_MMU |
657 | /* On NOMMU, we want to execute a child - copy of ourself. |
658 | * In chroot we usually can't do it. Thus we chdir |
659 | * out of the chroot back to original root, |
660 | * and (see later below) execute bb_busybox_exec_path |
661 | * relative to current directory */ |
662 | if (fchdir(G.root_fd) != 0) |
663 | _exit(127); |
664 | /*close(G.root_fd); - close_on_exec_on() took care of this */ |
665 | #endif |
666 | /* NB: close _first_, then move fd! */ |
667 | close(outfd.rd); |
668 | xmove_fd(outfd.wr, STDOUT_FILENO); |
669 | /* Opening /dev/null in chroot is hard. |
670 | * Just making sure STDIN_FILENO is opened |
671 | * to something harmless. Paranoia, |
672 | * ls won't read it anyway */ |
673 | close(STDIN_FILENO); |
674 | dup(STDOUT_FILENO); /* copy will become STDIN_FILENO */ |
675 | #if BB_MMU |
676 | /* memset(&G, 0, sizeof(G)); - ls_main does it */ |
677 | exit(ls_main(ARRAY_SIZE(argv) - 1, (char**) argv)); |
678 | #else |
679 | /* + 1: we must use relative path here if in chroot. |
680 | * For example, execv("/proc/self/exe") will fail, since |
681 | * it looks for "/proc/self/exe" _relative to chroot!_ */ |
682 | execv(bb_busybox_exec_path + 1, (char**) argv); |
683 | _exit(127); |
684 | #endif |
685 | } |
686 | |
687 | /* parent */ |
688 | close(outfd.wr); |
689 | #if !BB_MMU |
690 | free((char*)argv[2]); |
691 | #endif |
692 | return outfd.rd; |
693 | } |
694 | |
695 | enum { |
696 | USE_CTRL_CONN = 1, |
697 | LONG_LISTING = 2, |
698 | }; |
699 | |
700 | static void |
701 | handle_dir_common(int opts) |
702 | { |
703 | FILE *ls_fp; |
704 | char *line; |
705 | int ls_fd; |
706 | |
707 | if (!(opts & USE_CTRL_CONN) && !port_or_pasv_was_seen()) |
708 | return; /* port_or_pasv_was_seen emitted error response */ |
709 | |
710 | /* -n prevents user/groupname display, |
711 | * which can be problematic in chroot */ |
712 | ls_fd = popen_ls((opts & LONG_LISTING) ? "-l" : "-1"); |
713 | ls_fp = xfdopen_for_read(ls_fd); |
714 | |
715 | if (opts & USE_CTRL_CONN) { |
716 | /* STAT <filename> */ |
717 | cmdio_write_raw(STR(FTP_STATFILE_OK)"-File status:\r\n"); |
718 | while (1) { |
719 | line = xmalloc_fgetline(ls_fp); |
720 | if (!line) |
721 | break; |
722 | /* Hack: 0 results in no status at all */ |
723 | /* Note: it's ok that we don't prepend space, |
724 | * ftp.kernel.org doesn't do that too */ |
725 | cmdio_write(0, line); |
726 | free(line); |
727 | } |
728 | WRITE_OK(FTP_STATFILE_OK); |
729 | } else { |
730 | /* LIST/NLST [<filename>] */ |
731 | int remote_fd = get_remote_transfer_fd(" Directory listing"); |
732 | if (remote_fd >= 0) { |
733 | while (1) { |
734 | line = xmalloc_fgetline(ls_fp); |
735 | if (!line) |
736 | break; |
737 | /* I've seen clients complaining when they |
738 | * are fed with ls output with bare '\n'. |
739 | * Pity... that would be much simpler. |
740 | */ |
741 | /* TODO: need to s/LF/NUL/g here */ |
742 | xwrite_str(remote_fd, line); |
743 | xwrite(remote_fd, "\r\n", 2); |
744 | free(line); |
745 | } |
746 | } |
747 | close(remote_fd); |
748 | WRITE_OK(FTP_TRANSFEROK); |
749 | } |
750 | fclose(ls_fp); /* closes ls_fd too */ |
751 | } |
752 | static void |
753 | handle_list(void) |
754 | { |
755 | handle_dir_common(LONG_LISTING); |
756 | } |
757 | static void |
758 | handle_nlst(void) |
759 | { |
760 | /* NLST returns list of names, "\r\n" terminated without regard |
761 | * to the current binary flag. Names may start with "/", |
762 | * then they represent full names (we don't produce such names), |
763 | * otherwise names are relative to current directory. |
764 | * Embedded "\n" are replaced by NULs. This is safe since names |
765 | * can never contain NUL. |
766 | */ |
767 | handle_dir_common(0); |
768 | } |
769 | static void |
770 | handle_stat_file(void) |
771 | { |
772 | handle_dir_common(LONG_LISTING + USE_CTRL_CONN); |
773 | } |
774 | |
775 | /* This can be extended to handle MLST, as all info is available |
776 | * in struct stat for that: |
777 | * MLST file_name |
778 | * 250-Listing file_name |
779 | * type=file;size=4161;modify=19970214165800; /dir/dir/file_name |
780 | * 250 End |
781 | * Nano-doc: |
782 | * MLST [<file or dir name, "." assumed if not given>] |
783 | * Returned name should be either the same as requested, or fully qualified. |
784 | * If there was no parameter, return "" or (preferred) fully-qualified name. |
785 | * Returned "facts" (case is not important): |
786 | * size - size in octets |
787 | * modify - last modification time |
788 | * type - entry type (file,dir,OS.unix=block) |
789 | * (+ cdir and pdir types for MLSD) |
790 | * unique - unique id of file/directory (inode#) |
791 | * perm - |
792 | * a: can be appended to (APPE) |
793 | * d: can be deleted (RMD/DELE) |
794 | * f: can be renamed (RNFR) |
795 | * r: can be read (RETR) |
796 | * w: can be written (STOR) |
797 | * e: can CWD into this dir |
798 | * l: this dir can be listed (dir only!) |
799 | * c: can create files in this dir |
800 | * m: can create dirs in this dir (MKD) |
801 | * p: can delete files in this dir |
802 | * UNIX.mode - unix file mode |
803 | */ |
804 | static void |
805 | handle_size_or_mdtm(int need_size) |
806 | { |
807 | struct stat statbuf; |
808 | struct tm broken_out; |
809 | char buf[(sizeof("NNN %"OFF_FMT"u\r\n") + sizeof(off_t) * 3) |
810 | | sizeof("NNN YYYYMMDDhhmmss\r\n") |
811 | ]; |
812 | |
813 | if (!G.ftp_arg |
814 | || stat(G.ftp_arg, &statbuf) != 0 |
815 | || !S_ISREG(statbuf.st_mode) |
816 | ) { |
817 | WRITE_ERR(FTP_FILEFAIL); |
818 | return; |
819 | } |
820 | if (need_size) { |
821 | sprintf(buf, STR(FTP_STATFILE_OK)" %"OFF_FMT"u\r\n", statbuf.st_size); |
822 | } else { |
823 | gmtime_r(&statbuf.st_mtime, &broken_out); |
824 | sprintf(buf, STR(FTP_STATFILE_OK)" %04u%02u%02u%02u%02u%02u\r\n", |
825 | broken_out.tm_year + 1900, |
826 | broken_out.tm_mon, |
827 | broken_out.tm_mday, |
828 | broken_out.tm_hour, |
829 | broken_out.tm_min, |
830 | broken_out.tm_sec); |
831 | } |
832 | cmdio_write_raw(buf); |
833 | } |
834 | |
835 | /* Upload commands */ |
836 | |
837 | #if ENABLE_FEATURE_FTP_WRITE |
838 | static void |
839 | handle_mkd(void) |
840 | { |
841 | if (!G.ftp_arg || mkdir(G.ftp_arg, 0777) != 0) { |
842 | WRITE_ERR(FTP_FILEFAIL); |
843 | return; |
844 | } |
845 | WRITE_OK(FTP_MKDIROK); |
846 | } |
847 | |
848 | static void |
849 | handle_rmd(void) |
850 | { |
851 | if (!G.ftp_arg || rmdir(G.ftp_arg) != 0) { |
852 | WRITE_ERR(FTP_FILEFAIL); |
853 | return; |
854 | } |
855 | WRITE_OK(FTP_RMDIROK); |
856 | } |
857 | |
858 | static void |
859 | handle_dele(void) |
860 | { |
861 | if (!G.ftp_arg || unlink(G.ftp_arg) != 0) { |
862 | WRITE_ERR(FTP_FILEFAIL); |
863 | return; |
864 | } |
865 | WRITE_OK(FTP_DELEOK); |
866 | } |
867 | |
868 | static void |
869 | handle_rnfr(void) |
870 | { |
871 | free(G.rnfr_filename); |
872 | G.rnfr_filename = xstrdup(G.ftp_arg); |
873 | WRITE_OK(FTP_RNFROK); |
874 | } |
875 | |
876 | static void |
877 | handle_rnto(void) |
878 | { |
879 | int retval; |
880 | |
881 | /* If we didn't get a RNFR, throw a wobbly */ |
882 | if (G.rnfr_filename == NULL || G.ftp_arg == NULL) { |
883 | cmdio_write_raw(STR(FTP_NEEDRNFR)" Use RNFR first\r\n"); |
884 | return; |
885 | } |
886 | |
887 | retval = rename(G.rnfr_filename, G.ftp_arg); |
888 | free(G.rnfr_filename); |
889 | G.rnfr_filename = NULL; |
890 | |
891 | if (retval) { |
892 | WRITE_ERR(FTP_FILEFAIL); |
893 | return; |
894 | } |
895 | WRITE_OK(FTP_RENAMEOK); |
896 | } |
897 | |
898 | static void |
899 | handle_upload_common(int is_append, int is_unique) |
900 | { |
901 | struct stat statbuf; |
902 | char *tempname; |
903 | off_t bytes_transferred; |
904 | off_t offset; |
905 | int local_file_fd; |
906 | int remote_fd; |
907 | |
908 | offset = G.restart_pos; |
909 | G.restart_pos = 0; |
910 | |
911 | if (!port_or_pasv_was_seen()) |
912 | return; /* port_or_pasv_was_seen emitted error response */ |
913 | |
914 | tempname = NULL; |
915 | local_file_fd = -1; |
916 | if (is_unique) { |
917 | tempname = xstrdup(" FILE: uniq.XXXXXX"); |
918 | local_file_fd = mkstemp(tempname + 7); |
919 | } else if (G.ftp_arg) { |
920 | int flags = O_WRONLY | O_CREAT | O_TRUNC; |
921 | if (is_append) |
922 | flags = O_WRONLY | O_CREAT | O_APPEND; |
923 | if (offset) |
924 | flags = O_WRONLY | O_CREAT; |
925 | local_file_fd = open(G.ftp_arg, flags, 0666); |
926 | } |
927 | |
928 | if (local_file_fd < 0 |
929 | || fstat(local_file_fd, &statbuf) != 0 |
930 | || !S_ISREG(statbuf.st_mode) |
931 | ) { |
932 | WRITE_ERR(FTP_UPLOADFAIL); |
933 | if (local_file_fd >= 0) |
934 | goto close_local_and_bail; |
935 | return; |
936 | } |
937 | G.local_file_fd = local_file_fd; |
938 | |
939 | if (offset) |
940 | xlseek(local_file_fd, offset, SEEK_SET); |
941 | |
942 | remote_fd = get_remote_transfer_fd(tempname ? tempname : " Ok to send data"); |
943 | free(tempname); |
944 | |
945 | if (remote_fd < 0) |
946 | goto close_local_and_bail; |
947 | |
948 | bytes_transferred = bb_copyfd_eof(remote_fd, local_file_fd); |
949 | close(remote_fd); |
950 | if (bytes_transferred < 0) |
951 | WRITE_ERR(FTP_BADSENDFILE); |
952 | else |
953 | WRITE_OK(FTP_TRANSFEROK); |
954 | |
955 | close_local_and_bail: |
956 | close(local_file_fd); |
957 | G.local_file_fd = 0; |
958 | } |
959 | |
960 | static void |
961 | handle_stor(void) |
962 | { |
963 | handle_upload_common(0, 0); |
964 | } |
965 | |
966 | static void |
967 | handle_appe(void) |
968 | { |
969 | G.restart_pos = 0; |
970 | handle_upload_common(1, 0); |
971 | } |
972 | |
973 | static void |
974 | handle_stou(void) |
975 | { |
976 | G.restart_pos = 0; |
977 | handle_upload_common(0, 1); |
978 | } |
979 | #endif /* ENABLE_FEATURE_FTP_WRITE */ |
980 | |
981 | static uint32_t |
982 | cmdio_get_cmd_and_arg(void) |
983 | { |
984 | size_t len; |
985 | uint32_t cmdval; |
986 | char *cmd; |
987 | |
988 | alarm(G.timeout); |
989 | |
990 | free(G.ftp_cmd); |
991 | len = 8 * 1024; /* Paranoia. Peer may send 1 gigabyte long cmd... */ |
992 | G.ftp_cmd = cmd = xmalloc_fgets_str_len(stdin, "\r\n", &len); |
993 | if (!cmd) |
994 | exit(0); |
995 | |
996 | /* De-escape telnet: 0xff,0xff => 0xff */ |
997 | /* RFC959 says that ABOR, STAT, QUIT may be sent even during |
998 | * data transfer, and may be preceded by telnet's "Interrupt Process" |
999 | * code (two-byte sequence 255,244) and then by telnet "Synch" code |
1000 | * 255,242 (byte 242 is sent with TCP URG bit using send(MSG_OOB) |
1001 | * and may generate SIGURG on our side. See RFC854). |
1002 | * So far we don't support that (may install SIGURG handler if we'd want to), |
1003 | * but we need to at least remove 255,xxx pairs. lftp sends those. */ |
1004 | /* Then de-escape FTP: NUL => '\n' */ |
1005 | /* Testing for \xff: |
1006 | * Create file named '\xff': echo Hello >`echo -ne "\xff"` |
1007 | * Try to get it: ftpget -v 127.0.0.1 Eff `echo -ne "\xff\xff"` |
1008 | * (need "\xff\xff" until ftpget applet is fixed to do escaping :) |
1009 | * Testing for embedded LF: |
1010 | * LF_HERE=`echo -ne "LF\nHERE"` |
1011 | * echo Hello >"$LF_HERE" |
1012 | * ftpget -v 127.0.0.1 LF_HERE "$LF_HERE" |
1013 | */ |
1014 | { |
1015 | int dst, src; |
1016 | |
1017 | /* Strip "\r\n" if it is there */ |
1018 | if (len != 0 && cmd[len - 1] == '\n') { |
1019 | len--; |
1020 | if (len != 0 && cmd[len - 1] == '\r') |
1021 | len--; |
1022 | cmd[len] = '\0'; |
1023 | } |
1024 | src = strchrnul(cmd, 0xff) - cmd; |
1025 | /* 99,99% there are neither NULs nor 255s and src == len */ |
1026 | if (src < len) { |
1027 | dst = src; |
1028 | do { |
1029 | if ((unsigned char)(cmd[src]) == 255) { |
1030 | src++; |
1031 | /* 255,xxx - skip 255 */ |
1032 | if ((unsigned char)(cmd[src]) != 255) { |
1033 | /* 255,!255 - skip both */ |
1034 | src++; |
1035 | continue; |
1036 | } |
1037 | /* 255,255 - retain one 255 */ |
1038 | } |
1039 | /* NUL => '\n' */ |
1040 | cmd[dst++] = cmd[src] ? cmd[src] : '\n'; |
1041 | src++; |
1042 | } while (src < len); |
1043 | cmd[dst] = '\0'; |
1044 | } |
1045 | } |
1046 | |
1047 | if (G.verbose > 1) |
1048 | verbose_log(cmd); |
1049 | |
1050 | G.ftp_arg = strchr(cmd, ' '); |
1051 | if (G.ftp_arg != NULL) |
1052 | *G.ftp_arg++ = '\0'; |
1053 | |
1054 | /* Uppercase and pack into uint32_t first word of the command */ |
1055 | cmdval = 0; |
1056 | while (*cmd) |
1057 | cmdval = (cmdval << 8) + ((unsigned char)*cmd++ & (unsigned char)~0x20); |
1058 | |
1059 | return cmdval; |
1060 | } |
1061 | |
1062 | #define mk_const4(a,b,c,d) (((a * 0x100 + b) * 0x100 + c) * 0x100 + d) |
1063 | #define mk_const3(a,b,c) ((a * 0x100 + b) * 0x100 + c) |
1064 | enum { |
1065 | const_ALLO = mk_const4('A', 'L', 'L', 'O'), |
1066 | const_APPE = mk_const4('A', 'P', 'P', 'E'), |
1067 | const_CDUP = mk_const4('C', 'D', 'U', 'P'), |
1068 | const_CWD = mk_const3('C', 'W', 'D'), |
1069 | const_DELE = mk_const4('D', 'E', 'L', 'E'), |
1070 | const_EPSV = mk_const4('E', 'P', 'S', 'V'), |
1071 | const_FEAT = mk_const4('F', 'E', 'A', 'T'), |
1072 | const_HELP = mk_const4('H', 'E', 'L', 'P'), |
1073 | const_LIST = mk_const4('L', 'I', 'S', 'T'), |
1074 | const_MDTM = mk_const4('M', 'D', 'T', 'M'), |
1075 | const_MKD = mk_const3('M', 'K', 'D'), |
1076 | const_MODE = mk_const4('M', 'O', 'D', 'E'), |
1077 | const_NLST = mk_const4('N', 'L', 'S', 'T'), |
1078 | const_NOOP = mk_const4('N', 'O', 'O', 'P'), |
1079 | const_PASS = mk_const4('P', 'A', 'S', 'S'), |
1080 | const_PASV = mk_const4('P', 'A', 'S', 'V'), |
1081 | const_PORT = mk_const4('P', 'O', 'R', 'T'), |
1082 | const_PWD = mk_const3('P', 'W', 'D'), |
1083 | const_QUIT = mk_const4('Q', 'U', 'I', 'T'), |
1084 | const_REST = mk_const4('R', 'E', 'S', 'T'), |
1085 | const_RETR = mk_const4('R', 'E', 'T', 'R'), |
1086 | const_RMD = mk_const3('R', 'M', 'D'), |
1087 | const_RNFR = mk_const4('R', 'N', 'F', 'R'), |
1088 | const_RNTO = mk_const4('R', 'N', 'T', 'O'), |
1089 | const_SIZE = mk_const4('S', 'I', 'Z', 'E'), |
1090 | const_STAT = mk_const4('S', 'T', 'A', 'T'), |
1091 | const_STOR = mk_const4('S', 'T', 'O', 'R'), |
1092 | const_STOU = mk_const4('S', 'T', 'O', 'U'), |
1093 | const_STRU = mk_const4('S', 'T', 'R', 'U'), |
1094 | const_SYST = mk_const4('S', 'Y', 'S', 'T'), |
1095 | const_TYPE = mk_const4('T', 'Y', 'P', 'E'), |
1096 | const_USER = mk_const4('U', 'S', 'E', 'R'), |
1097 | |
1098 | #if !BB_MMU |
1099 | OPT_l = (1 << 0), |
1100 | OPT_1 = (1 << 1), |
1101 | #endif |
1102 | OPT_v = (1 << ((!BB_MMU) * 2 + 0)), |
1103 | OPT_S = (1 << ((!BB_MMU) * 2 + 1)), |
1104 | OPT_w = (1 << ((!BB_MMU) * 2 + 2)) * ENABLE_FEATURE_FTP_WRITE, |
1105 | }; |
1106 | |
1107 | int ftpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
1108 | #if !BB_MMU |
1109 | int ftpd_main(int argc, char **argv) |
1110 | #else |
1111 | int ftpd_main(int argc UNUSED_PARAM, char **argv) |
1112 | #endif |
1113 | { |
1114 | unsigned abs_timeout; |
1115 | unsigned verbose_S; |
1116 | smallint opts; |
1117 | |
1118 | INIT_G(); |
1119 | |
1120 | abs_timeout = 1 * 60 * 60; |
1121 | verbose_S = 0; |
1122 | G.timeout = 2 * 60; |
1123 | opt_complementary = "t+:T+:vv:SS"; |
1124 | #if BB_MMU |
1125 | opts = getopt32(argv, "vS" IF_FEATURE_FTP_WRITE("w") "t:T:", &G.timeout, &abs_timeout, &G.verbose, &verbose_S); |
1126 | #else |
1127 | opts = getopt32(argv, "l1vS" IF_FEATURE_FTP_WRITE("w") "t:T:", &G.timeout, &abs_timeout, &G.verbose, &verbose_S); |
1128 | if (opts & (OPT_l|OPT_1)) { |
1129 | /* Our secret backdoor to ls */ |
1130 | /* TODO: pass -n? It prevents user/group resolution, whicj may not work in chroot anyway */ |
1131 | /* TODO: pass -A? It shows dot files */ |
1132 | /* TODO: pass --group-directories-first? would be nice, but ls don't do that yet */ |
1133 | xchdir(argv[2]); |
1134 | argv[2] = (char*)"--"; |
1135 | /* memset(&G, 0, sizeof(G)); - ls_main does it */ |
1136 | return ls_main(argc, argv); |
1137 | } |
1138 | #endif |
1139 | if (G.verbose < verbose_S) |
1140 | G.verbose = verbose_S; |
1141 | if (abs_timeout | G.timeout) { |
1142 | if (abs_timeout == 0) |
1143 | abs_timeout = INT_MAX; |
1144 | G.end_time = monotonic_sec() + abs_timeout; |
1145 | if (G.timeout > abs_timeout) |
1146 | G.timeout = abs_timeout; |
1147 | } |
1148 | strcpy(G.msg_ok + 4, MSG_OK ); |
1149 | strcpy(G.msg_err + 4, MSG_ERR); |
1150 | |
1151 | G.local_addr = get_sock_lsa(STDIN_FILENO); |
1152 | if (!G.local_addr) { |
1153 | /* This is confusing: |
1154 | * bb_error_msg_and_die("stdin is not a socket"); |
1155 | * Better: */ |
1156 | bb_show_usage(); |
1157 | /* Help text says that ftpd must be used as inetd service, |
1158 | * which is by far the most usual cause of get_sock_lsa |
1159 | * failure */ |
1160 | } |
1161 | |
1162 | if (!(opts & OPT_v)) |
1163 | logmode = LOGMODE_NONE; |
1164 | if (opts & OPT_S) { |
1165 | /* LOG_NDELAY is needed since we may chroot later */ |
1166 | openlog(applet_name, LOG_PID | LOG_NDELAY, LOG_DAEMON); |
1167 | logmode |= LOGMODE_SYSLOG; |
1168 | } |
1169 | if (logmode) |
1170 | applet_name = xasprintf("%s[%u]", applet_name, (int)getpid()); |
1171 | |
1172 | #if !BB_MMU |
1173 | G.root_fd = xopen("/", O_RDONLY | O_DIRECTORY); |
1174 | close_on_exec_on(G.root_fd); |
1175 | #endif |
1176 | |
1177 | if (argv[optind]) { |
1178 | xchdir(argv[optind]); |
1179 | chroot("."); |
1180 | } |
1181 | |
1182 | //umask(077); - admin can set umask before starting us |
1183 | |
1184 | /* Signals. We'll always take -EPIPE rather than a rude signal, thanks */ |
1185 | signal(SIGPIPE, SIG_IGN); |
1186 | |
1187 | /* Set up options on the command socket (do we need these all? why?) */ |
1188 | setsockopt(STDIN_FILENO, IPPROTO_TCP, TCP_NODELAY, &const_int_1, sizeof(const_int_1)); |
1189 | setsockopt(STDIN_FILENO, SOL_SOCKET, SO_KEEPALIVE, &const_int_1, sizeof(const_int_1)); |
1190 | /* Telnet protocol over command link may send "urgent" data, |
1191 | * we prefer it to be received in the "normal" data stream: */ |
1192 | setsockopt(STDIN_FILENO, SOL_SOCKET, SO_OOBINLINE, &const_int_1, sizeof(const_int_1)); |
1193 | |
1194 | WRITE_OK(FTP_GREET); |
1195 | signal(SIGALRM, timeout_handler); |
1196 | |
1197 | #ifdef IF_WE_WANT_TO_REQUIRE_LOGIN |
1198 | { |
1199 | smallint user_was_specified = 0; |
1200 | while (1) { |
1201 | uint32_t cmdval = cmdio_get_cmd_and_arg(); |
1202 | |
1203 | if (cmdval == const_USER) { |
1204 | if (G.ftp_arg == NULL || strcasecmp(G.ftp_arg, "anonymous") != 0) |
1205 | cmdio_write_raw(STR(FTP_LOGINERR)" Server is anonymous only\r\n"); |
1206 | else { |
1207 | user_was_specified = 1; |
1208 | cmdio_write_raw(STR(FTP_GIVEPWORD)" Please specify the password\r\n"); |
1209 | } |
1210 | } else if (cmdval == const_PASS) { |
1211 | if (user_was_specified) |
1212 | break; |
1213 | cmdio_write_raw(STR(FTP_NEEDUSER)" Login with USER\r\n"); |
1214 | } else if (cmdval == const_QUIT) { |
1215 | WRITE_OK(FTP_GOODBYE); |
1216 | return 0; |
1217 | } else { |
1218 | cmdio_write_raw(STR(FTP_LOGINERR)" Login with USER and PASS\r\n"); |
1219 | } |
1220 | } |
1221 | } |
1222 | WRITE_OK(FTP_LOGINOK); |
1223 | #endif |
1224 | |
1225 | /* RFC-959 Section 5.1 |
1226 | * The following commands and options MUST be supported by every |
1227 | * server-FTP and user-FTP, except in cases where the underlying |
1228 | * file system or operating system does not allow or support |
1229 | * a particular command. |
1230 | * Type: ASCII Non-print, IMAGE, LOCAL 8 |
1231 | * Mode: Stream |
1232 | * Structure: File, Record* |
1233 | * (Record structure is REQUIRED only for hosts whose file |
1234 | * systems support record structure). |
1235 | * Commands: |
1236 | * USER, PASS, ACCT, [bbox: ACCT not supported] |
1237 | * PORT, PASV, |
1238 | * TYPE, MODE, STRU, |
1239 | * RETR, STOR, APPE, |
1240 | * RNFR, RNTO, DELE, |
1241 | * CWD, CDUP, RMD, MKD, PWD, |
1242 | * LIST, NLST, |
1243 | * SYST, STAT, |
1244 | * HELP, NOOP, QUIT. |
1245 | */ |
1246 | /* ACCOUNT (ACCT) |
1247 | * "The argument field is a Telnet string identifying the user's account. |
1248 | * The command is not necessarily related to the USER command, as some |
1249 | * sites may require an account for login and others only for specific |
1250 | * access, such as storing files. In the latter case the command may |
1251 | * arrive at any time. |
1252 | * There are reply codes to differentiate these cases for the automation: |
1253 | * when account information is required for login, the response to |
1254 | * a successful PASSword command is reply code 332. On the other hand, |
1255 | * if account information is NOT required for login, the reply to |
1256 | * a successful PASSword command is 230; and if the account information |
1257 | * is needed for a command issued later in the dialogue, the server |
1258 | * should return a 332 or 532 reply depending on whether it stores |
1259 | * (pending receipt of the ACCounT command) or discards the command, |
1260 | * respectively." |
1261 | */ |
1262 | |
1263 | while (1) { |
1264 | uint32_t cmdval = cmdio_get_cmd_and_arg(); |
1265 | |
1266 | if (cmdval == const_QUIT) { |
1267 | WRITE_OK(FTP_GOODBYE); |
1268 | return 0; |
1269 | } |
1270 | else if (cmdval == const_USER) |
1271 | /* This would mean "ok, now give me PASS". */ |
1272 | /*WRITE_OK(FTP_GIVEPWORD);*/ |
1273 | /* vsftpd can be configured to not require that, |
1274 | * and this also saves one roundtrip: |
1275 | */ |
1276 | WRITE_OK(FTP_LOGINOK); |
1277 | else if (cmdval == const_PASS) |
1278 | WRITE_OK(FTP_LOGINOK); |
1279 | else if (cmdval == const_NOOP) |
1280 | WRITE_OK(FTP_NOOPOK); |
1281 | else if (cmdval == const_TYPE) |
1282 | WRITE_OK(FTP_TYPEOK); |
1283 | else if (cmdval == const_STRU) |
1284 | WRITE_OK(FTP_STRUOK); |
1285 | else if (cmdval == const_MODE) |
1286 | WRITE_OK(FTP_MODEOK); |
1287 | else if (cmdval == const_ALLO) |
1288 | WRITE_OK(FTP_ALLOOK); |
1289 | else if (cmdval == const_SYST) |
1290 | cmdio_write_raw(STR(FTP_SYSTOK)" UNIX Type: L8\r\n"); |
1291 | else if (cmdval == const_PWD) |
1292 | handle_pwd(); |
1293 | else if (cmdval == const_CWD) |
1294 | handle_cwd(); |
1295 | else if (cmdval == const_CDUP) /* cd .. */ |
1296 | handle_cdup(); |
1297 | /* HELP is nearly useless, but we can reuse FEAT for it */ |
1298 | /* lftp uses FEAT */ |
1299 | else if (cmdval == const_HELP || cmdval == const_FEAT) |
1300 | handle_feat(cmdval == const_HELP |
1301 | ? STRNUM32(FTP_HELP) |
1302 | : STRNUM32(FTP_STATOK) |
1303 | ); |
1304 | else if (cmdval == const_LIST) /* ls -l */ |
1305 | handle_list(); |
1306 | else if (cmdval == const_NLST) /* "name list", bare ls */ |
1307 | handle_nlst(); |
1308 | /* SIZE is crucial for wget's download indicator etc */ |
1309 | /* Mozilla, lftp use MDTM (presumably for caching) */ |
1310 | else if (cmdval == const_SIZE || cmdval == const_MDTM) |
1311 | handle_size_or_mdtm(cmdval == const_SIZE); |
1312 | else if (cmdval == const_STAT) { |
1313 | if (G.ftp_arg == NULL) |
1314 | handle_stat(); |
1315 | else |
1316 | handle_stat_file(); |
1317 | } |
1318 | else if (cmdval == const_PASV) |
1319 | handle_pasv(); |
1320 | else if (cmdval == const_EPSV) |
1321 | handle_epsv(); |
1322 | else if (cmdval == const_RETR) |
1323 | handle_retr(); |
1324 | else if (cmdval == const_PORT) |
1325 | handle_port(); |
1326 | else if (cmdval == const_REST) |
1327 | handle_rest(); |
1328 | #if ENABLE_FEATURE_FTP_WRITE |
1329 | else if (opts & OPT_w) { |
1330 | if (cmdval == const_STOR) |
1331 | handle_stor(); |
1332 | else if (cmdval == const_MKD) |
1333 | handle_mkd(); |
1334 | else if (cmdval == const_RMD) |
1335 | handle_rmd(); |
1336 | else if (cmdval == const_DELE) |
1337 | handle_dele(); |
1338 | else if (cmdval == const_RNFR) /* "rename from" */ |
1339 | handle_rnfr(); |
1340 | else if (cmdval == const_RNTO) /* "rename to" */ |
1341 | handle_rnto(); |
1342 | else if (cmdval == const_APPE) |
1343 | handle_appe(); |
1344 | else if (cmdval == const_STOU) /* "store unique" */ |
1345 | handle_stou(); |
1346 | else |
1347 | goto bad_cmd; |
1348 | } |
1349 | #endif |
1350 | #if 0 |
1351 | else if (cmdval == const_STOR |
1352 | || cmdval == const_MKD |
1353 | || cmdval == const_RMD |
1354 | || cmdval == const_DELE |
1355 | || cmdval == const_RNFR |
1356 | || cmdval == const_RNTO |
1357 | || cmdval == const_APPE |
1358 | || cmdval == const_STOU |
1359 | ) { |
1360 | cmdio_write_raw(STR(FTP_NOPERM)" Permission denied\r\n"); |
1361 | } |
1362 | #endif |
1363 | else { |
1364 | /* Which unsupported commands were seen in the wild? |
1365 | * (doesn't necessarily mean "we must support them") |
1366 | * foo 1.2.3: XXXX - comment |
1367 | */ |
1368 | #if ENABLE_FEATURE_FTP_WRITE |
1369 | bad_cmd: |
1370 | #endif |
1371 | cmdio_write_raw(STR(FTP_BADCMD)" Unknown command\r\n"); |
1372 | } |
1373 | } |
1374 | } |