1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* FTP extension for connection tracking. */ |
3 | |
4 | /* (C) 1999-2001 Paul `Rusty' Russell |
5 | * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org> |
6 | * (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org> |
7 | * (C) 2006-2012 Patrick McHardy <kaber@trash.net> |
8 | */ |
9 | |
10 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
11 | |
12 | #include <linux/module.h> |
13 | #include <linux/moduleparam.h> |
14 | #include <linux/netfilter.h> |
15 | #include <linux/ip.h> |
16 | #include <linux/slab.h> |
17 | #include <linux/ipv6.h> |
18 | #include <linux/ctype.h> |
19 | #include <linux/inet.h> |
20 | #include <net/checksum.h> |
21 | #include <net/tcp.h> |
22 | |
23 | #include <net/netfilter/nf_conntrack.h> |
24 | #include <net/netfilter/nf_conntrack_expect.h> |
25 | #include <net/netfilter/nf_conntrack_ecache.h> |
26 | #include <net/netfilter/nf_conntrack_helper.h> |
27 | #include <linux/netfilter/nf_conntrack_ftp.h> |
28 | |
29 | #define HELPER_NAME "ftp" |
30 | |
31 | MODULE_LICENSE("GPL" ); |
32 | MODULE_AUTHOR("Rusty Russell <rusty@rustcorp.com.au>" ); |
33 | MODULE_DESCRIPTION("ftp connection tracking helper" ); |
34 | MODULE_ALIAS("ip_conntrack_ftp" ); |
35 | MODULE_ALIAS_NFCT_HELPER(HELPER_NAME); |
36 | static DEFINE_SPINLOCK(nf_ftp_lock); |
37 | |
38 | #define MAX_PORTS 8 |
39 | static u_int16_t ports[MAX_PORTS]; |
40 | static unsigned int ports_c; |
41 | module_param_array(ports, ushort, &ports_c, 0400); |
42 | |
43 | static bool loose; |
44 | module_param(loose, bool, 0600); |
45 | |
46 | unsigned int (*nf_nat_ftp_hook)(struct sk_buff *skb, |
47 | enum ip_conntrack_info ctinfo, |
48 | enum nf_ct_ftp_type type, |
49 | unsigned int protoff, |
50 | unsigned int matchoff, |
51 | unsigned int matchlen, |
52 | struct nf_conntrack_expect *exp); |
53 | EXPORT_SYMBOL_GPL(nf_nat_ftp_hook); |
54 | |
55 | static int try_rfc959(const char *, size_t, struct nf_conntrack_man *, |
56 | char, unsigned int *); |
57 | static int try_rfc1123(const char *, size_t, struct nf_conntrack_man *, |
58 | char, unsigned int *); |
59 | static int try_eprt(const char *, size_t, struct nf_conntrack_man *, |
60 | char, unsigned int *); |
61 | static int try_epsv_response(const char *, size_t, struct nf_conntrack_man *, |
62 | char, unsigned int *); |
63 | |
64 | static struct ftp_search { |
65 | const char *pattern; |
66 | size_t plen; |
67 | char skip; |
68 | char term; |
69 | enum nf_ct_ftp_type ftptype; |
70 | int (*getnum)(const char *, size_t, struct nf_conntrack_man *, char, unsigned int *); |
71 | } search[IP_CT_DIR_MAX][2] = { |
72 | [IP_CT_DIR_ORIGINAL] = { |
73 | { |
74 | .pattern = "PORT" , |
75 | .plen = sizeof("PORT" ) - 1, |
76 | .skip = ' ', |
77 | .term = '\r', |
78 | .ftptype = NF_CT_FTP_PORT, |
79 | .getnum = try_rfc959, |
80 | }, |
81 | { |
82 | .pattern = "EPRT" , |
83 | .plen = sizeof("EPRT" ) - 1, |
84 | .skip = ' ', |
85 | .term = '\r', |
86 | .ftptype = NF_CT_FTP_EPRT, |
87 | .getnum = try_eprt, |
88 | }, |
89 | }, |
90 | [IP_CT_DIR_REPLY] = { |
91 | { |
92 | .pattern = "227 " , |
93 | .plen = sizeof("227 " ) - 1, |
94 | .ftptype = NF_CT_FTP_PASV, |
95 | .getnum = try_rfc1123, |
96 | }, |
97 | { |
98 | .pattern = "229 " , |
99 | .plen = sizeof("229 " ) - 1, |
100 | .skip = '(', |
101 | .term = ')', |
102 | .ftptype = NF_CT_FTP_EPSV, |
103 | .getnum = try_epsv_response, |
104 | }, |
105 | }, |
106 | }; |
107 | |
108 | static int |
109 | get_ipv6_addr(const char *src, size_t dlen, struct in6_addr *dst, u_int8_t term) |
110 | { |
111 | const char *end; |
112 | int ret = in6_pton(src, min_t(size_t, dlen, 0xffff), dst: (u8 *)dst, delim: term, end: &end); |
113 | if (ret > 0) |
114 | return (int)(end - src); |
115 | return 0; |
116 | } |
117 | |
118 | static int try_number(const char *data, size_t dlen, u_int32_t array[], |
119 | int array_size, char sep, char term) |
120 | { |
121 | u_int32_t i, len; |
122 | |
123 | memset(array, 0, sizeof(array[0])*array_size); |
124 | |
125 | /* Keep data pointing at next char. */ |
126 | for (i = 0, len = 0; len < dlen && i < array_size; len++, data++) { |
127 | if (*data >= '0' && *data <= '9') { |
128 | array[i] = array[i]*10 + *data - '0'; |
129 | } |
130 | else if (*data == sep) |
131 | i++; |
132 | else { |
133 | /* Unexpected character; true if it's the |
134 | terminator (or we don't care about one) |
135 | and we're finished. */ |
136 | if ((*data == term || !term) && i == array_size - 1) |
137 | return len; |
138 | |
139 | pr_debug("Char %u (got %u nums) `%u' unexpected\n" , |
140 | len, i, *data); |
141 | return 0; |
142 | } |
143 | } |
144 | pr_debug("Failed to fill %u numbers separated by %c\n" , |
145 | array_size, sep); |
146 | return 0; |
147 | } |
148 | |
149 | /* Returns 0, or length of numbers: 192,168,1,1,5,6 */ |
150 | static int try_rfc959(const char *data, size_t dlen, |
151 | struct nf_conntrack_man *cmd, char term, |
152 | unsigned int *offset) |
153 | { |
154 | int length; |
155 | u_int32_t array[6]; |
156 | |
157 | length = try_number(data, dlen, array, array_size: 6, sep: ',', term); |
158 | if (length == 0) |
159 | return 0; |
160 | |
161 | cmd->u3.ip = htonl((array[0] << 24) | (array[1] << 16) | |
162 | (array[2] << 8) | array[3]); |
163 | cmd->u.tcp.port = htons((array[4] << 8) | array[5]); |
164 | return length; |
165 | } |
166 | |
167 | /* |
168 | * From RFC 1123: |
169 | * The format of the 227 reply to a PASV command is not |
170 | * well standardized. In particular, an FTP client cannot |
171 | * assume that the parentheses shown on page 40 of RFC-959 |
172 | * will be present (and in fact, Figure 3 on page 43 omits |
173 | * them). Therefore, a User-FTP program that interprets |
174 | * the PASV reply must scan the reply for the first digit |
175 | * of the host and port numbers. |
176 | */ |
177 | static int try_rfc1123(const char *data, size_t dlen, |
178 | struct nf_conntrack_man *cmd, char term, |
179 | unsigned int *offset) |
180 | { |
181 | int i; |
182 | for (i = 0; i < dlen; i++) |
183 | if (isdigit(c: data[i])) |
184 | break; |
185 | |
186 | if (i == dlen) |
187 | return 0; |
188 | |
189 | *offset += i; |
190 | |
191 | return try_rfc959(data: data + i, dlen: dlen - i, cmd, term: 0, offset); |
192 | } |
193 | |
194 | /* Grab port: number up to delimiter */ |
195 | static int get_port(const char *data, int start, size_t dlen, char delim, |
196 | __be16 *port) |
197 | { |
198 | u_int16_t tmp_port = 0; |
199 | int i; |
200 | |
201 | for (i = start; i < dlen; i++) { |
202 | /* Finished? */ |
203 | if (data[i] == delim) { |
204 | if (tmp_port == 0) |
205 | break; |
206 | *port = htons(tmp_port); |
207 | pr_debug("get_port: return %d\n" , tmp_port); |
208 | return i + 1; |
209 | } |
210 | else if (data[i] >= '0' && data[i] <= '9') |
211 | tmp_port = tmp_port*10 + data[i] - '0'; |
212 | else { /* Some other crap */ |
213 | pr_debug("get_port: invalid char.\n" ); |
214 | break; |
215 | } |
216 | } |
217 | return 0; |
218 | } |
219 | |
220 | /* Returns 0, or length of numbers: |1|132.235.1.2|6275| or |2|3ffe::1|6275| */ |
221 | static int try_eprt(const char *data, size_t dlen, struct nf_conntrack_man *cmd, |
222 | char term, unsigned int *offset) |
223 | { |
224 | char delim; |
225 | int length; |
226 | |
227 | /* First character is delimiter, then "1" for IPv4 or "2" for IPv6, |
228 | then delimiter again. */ |
229 | if (dlen <= 3) { |
230 | pr_debug("EPRT: too short\n" ); |
231 | return 0; |
232 | } |
233 | delim = data[0]; |
234 | if (isdigit(c: delim) || delim < 33 || delim > 126 || data[2] != delim) { |
235 | pr_debug("try_eprt: invalid delimiter.\n" ); |
236 | return 0; |
237 | } |
238 | |
239 | if ((cmd->l3num == PF_INET && data[1] != '1') || |
240 | (cmd->l3num == PF_INET6 && data[1] != '2')) { |
241 | pr_debug("EPRT: invalid protocol number.\n" ); |
242 | return 0; |
243 | } |
244 | |
245 | pr_debug("EPRT: Got %c%c%c\n" , delim, data[1], delim); |
246 | |
247 | if (data[1] == '1') { |
248 | u_int32_t array[4]; |
249 | |
250 | /* Now we have IP address. */ |
251 | length = try_number(data: data + 3, dlen: dlen - 3, array, array_size: 4, sep: '.', term: delim); |
252 | if (length != 0) |
253 | cmd->u3.ip = htonl((array[0] << 24) | (array[1] << 16) |
254 | | (array[2] << 8) | array[3]); |
255 | } else { |
256 | /* Now we have IPv6 address. */ |
257 | length = get_ipv6_addr(src: data + 3, dlen: dlen - 3, |
258 | dst: (struct in6_addr *)cmd->u3.ip6, term: delim); |
259 | } |
260 | |
261 | if (length == 0) |
262 | return 0; |
263 | pr_debug("EPRT: Got IP address!\n" ); |
264 | /* Start offset includes initial "|1|", and trailing delimiter */ |
265 | return get_port(data, start: 3 + length + 1, dlen, delim, port: &cmd->u.tcp.port); |
266 | } |
267 | |
268 | /* Returns 0, or length of numbers: |||6446| */ |
269 | static int try_epsv_response(const char *data, size_t dlen, |
270 | struct nf_conntrack_man *cmd, char term, |
271 | unsigned int *offset) |
272 | { |
273 | char delim; |
274 | |
275 | /* Three delimiters. */ |
276 | if (dlen <= 3) return 0; |
277 | delim = data[0]; |
278 | if (isdigit(c: delim) || delim < 33 || delim > 126 || |
279 | data[1] != delim || data[2] != delim) |
280 | return 0; |
281 | |
282 | return get_port(data, start: 3, dlen, delim, port: &cmd->u.tcp.port); |
283 | } |
284 | |
285 | /* Return 1 for match, 0 for accept, -1 for partial. */ |
286 | static int find_pattern(const char *data, size_t dlen, |
287 | const char *pattern, size_t plen, |
288 | char skip, char term, |
289 | unsigned int *numoff, |
290 | unsigned int *numlen, |
291 | struct nf_conntrack_man *cmd, |
292 | int (*getnum)(const char *, size_t, |
293 | struct nf_conntrack_man *, char, |
294 | unsigned int *)) |
295 | { |
296 | size_t i = plen; |
297 | |
298 | pr_debug("find_pattern `%s': dlen = %zu\n" , pattern, dlen); |
299 | |
300 | if (dlen <= plen) { |
301 | /* Short packet: try for partial? */ |
302 | if (strncasecmp(s1: data, s2: pattern, n: dlen) == 0) |
303 | return -1; |
304 | else return 0; |
305 | } |
306 | |
307 | if (strncasecmp(s1: data, s2: pattern, n: plen) != 0) |
308 | return 0; |
309 | |
310 | pr_debug("Pattern matches!\n" ); |
311 | /* Now we've found the constant string, try to skip |
312 | to the 'skip' character */ |
313 | if (skip) { |
314 | for (i = plen; data[i] != skip; i++) |
315 | if (i == dlen - 1) return -1; |
316 | |
317 | /* Skip over the last character */ |
318 | i++; |
319 | } |
320 | |
321 | pr_debug("Skipped up to 0x%hhx delimiter!\n" , skip); |
322 | |
323 | *numoff = i; |
324 | *numlen = getnum(data + i, dlen - i, cmd, term, numoff); |
325 | if (!*numlen) |
326 | return -1; |
327 | |
328 | pr_debug("Match succeeded!\n" ); |
329 | return 1; |
330 | } |
331 | |
332 | /* Look up to see if we're just after a \n. */ |
333 | static int find_nl_seq(u32 seq, const struct nf_ct_ftp_master *info, int dir) |
334 | { |
335 | unsigned int i; |
336 | |
337 | for (i = 0; i < info->seq_aft_nl_num[dir]; i++) |
338 | if (info->seq_aft_nl[dir][i] == seq) |
339 | return 1; |
340 | return 0; |
341 | } |
342 | |
343 | /* We don't update if it's older than what we have. */ |
344 | static void update_nl_seq(struct nf_conn *ct, u32 nl_seq, |
345 | struct nf_ct_ftp_master *info, int dir, |
346 | struct sk_buff *skb) |
347 | { |
348 | unsigned int i, oldest; |
349 | |
350 | /* Look for oldest: if we find exact match, we're done. */ |
351 | for (i = 0; i < info->seq_aft_nl_num[dir]; i++) { |
352 | if (info->seq_aft_nl[dir][i] == nl_seq) |
353 | return; |
354 | } |
355 | |
356 | if (info->seq_aft_nl_num[dir] < NUM_SEQ_TO_REMEMBER) { |
357 | info->seq_aft_nl[dir][info->seq_aft_nl_num[dir]++] = nl_seq; |
358 | } else { |
359 | if (before(seq1: info->seq_aft_nl[dir][0], seq2: info->seq_aft_nl[dir][1])) |
360 | oldest = 0; |
361 | else |
362 | oldest = 1; |
363 | |
364 | if (after(nl_seq, info->seq_aft_nl[dir][oldest])) |
365 | info->seq_aft_nl[dir][oldest] = nl_seq; |
366 | } |
367 | } |
368 | |
369 | static int help(struct sk_buff *skb, |
370 | unsigned int protoff, |
371 | struct nf_conn *ct, |
372 | enum ip_conntrack_info ctinfo) |
373 | { |
374 | unsigned int dataoff, datalen; |
375 | const struct tcphdr *th; |
376 | struct tcphdr _tcph; |
377 | const char *fb_ptr; |
378 | int ret; |
379 | u32 seq; |
380 | int dir = CTINFO2DIR(ctinfo); |
381 | unsigned int matchlen, matchoff; |
382 | struct nf_ct_ftp_master *ct_ftp_info = nfct_help_data(ct); |
383 | struct nf_conntrack_expect *exp; |
384 | union nf_inet_addr *daddr; |
385 | struct nf_conntrack_man cmd = {}; |
386 | unsigned int i; |
387 | int found = 0, ends_in_nl; |
388 | typeof(nf_nat_ftp_hook) nf_nat_ftp; |
389 | |
390 | /* Until there's been traffic both ways, don't look in packets. */ |
391 | if (ctinfo != IP_CT_ESTABLISHED && |
392 | ctinfo != IP_CT_ESTABLISHED_REPLY) { |
393 | pr_debug("ftp: Conntrackinfo = %u\n" , ctinfo); |
394 | return NF_ACCEPT; |
395 | } |
396 | |
397 | if (unlikely(skb_linearize(skb))) |
398 | return NF_DROP; |
399 | |
400 | th = skb_header_pointer(skb, offset: protoff, len: sizeof(_tcph), buffer: &_tcph); |
401 | if (th == NULL) |
402 | return NF_ACCEPT; |
403 | |
404 | dataoff = protoff + th->doff * 4; |
405 | /* No data? */ |
406 | if (dataoff >= skb->len) { |
407 | pr_debug("ftp: dataoff(%u) >= skblen(%u)\n" , dataoff, |
408 | skb->len); |
409 | return NF_ACCEPT; |
410 | } |
411 | datalen = skb->len - dataoff; |
412 | |
413 | /* seqadj (nat) uses ct->lock internally, nf_nat_ftp would cause deadlock */ |
414 | spin_lock_bh(lock: &nf_ftp_lock); |
415 | fb_ptr = skb->data + dataoff; |
416 | |
417 | ends_in_nl = (fb_ptr[datalen - 1] == '\n'); |
418 | seq = ntohl(th->seq) + datalen; |
419 | |
420 | /* Look up to see if we're just after a \n. */ |
421 | if (!find_nl_seq(ntohl(th->seq), info: ct_ftp_info, dir)) { |
422 | /* We're picking up this, clear flags and let it continue */ |
423 | if (unlikely(ct_ftp_info->flags[dir] & NF_CT_FTP_SEQ_PICKUP)) { |
424 | ct_ftp_info->flags[dir] ^= NF_CT_FTP_SEQ_PICKUP; |
425 | goto skip_nl_seq; |
426 | } |
427 | |
428 | /* Now if this ends in \n, update ftp info. */ |
429 | pr_debug("nf_conntrack_ftp: wrong seq pos %s(%u) or %s(%u)\n" , |
430 | ct_ftp_info->seq_aft_nl_num[dir] > 0 ? "" : "(UNSET)" , |
431 | ct_ftp_info->seq_aft_nl[dir][0], |
432 | ct_ftp_info->seq_aft_nl_num[dir] > 1 ? "" : "(UNSET)" , |
433 | ct_ftp_info->seq_aft_nl[dir][1]); |
434 | ret = NF_ACCEPT; |
435 | goto out_update_nl; |
436 | } |
437 | |
438 | skip_nl_seq: |
439 | /* Initialize IP/IPv6 addr to expected address (it's not mentioned |
440 | in EPSV responses) */ |
441 | cmd.l3num = nf_ct_l3num(ct); |
442 | memcpy(cmd.u3.all, &ct->tuplehash[dir].tuple.src.u3.all, |
443 | sizeof(cmd.u3.all)); |
444 | |
445 | for (i = 0; i < ARRAY_SIZE(search[dir]); i++) { |
446 | found = find_pattern(data: fb_ptr, dlen: datalen, |
447 | pattern: search[dir][i].pattern, |
448 | plen: search[dir][i].plen, |
449 | skip: search[dir][i].skip, |
450 | term: search[dir][i].term, |
451 | numoff: &matchoff, numlen: &matchlen, |
452 | cmd: &cmd, |
453 | getnum: search[dir][i].getnum); |
454 | if (found) break; |
455 | } |
456 | if (found == -1) { |
457 | /* We don't usually drop packets. After all, this is |
458 | connection tracking, not packet filtering. |
459 | However, it is necessary for accurate tracking in |
460 | this case. */ |
461 | nf_ct_helper_log(skb, ct, fmt: "partial matching of `%s'" , |
462 | search[dir][i].pattern); |
463 | ret = NF_DROP; |
464 | goto out; |
465 | } else if (found == 0) { /* No match */ |
466 | ret = NF_ACCEPT; |
467 | goto out_update_nl; |
468 | } |
469 | |
470 | pr_debug("conntrack_ftp: match `%.*s' (%u bytes at %u)\n" , |
471 | matchlen, fb_ptr + matchoff, |
472 | matchlen, ntohl(th->seq) + matchoff); |
473 | |
474 | exp = nf_ct_expect_alloc(me: ct); |
475 | if (exp == NULL) { |
476 | nf_ct_helper_log(skb, ct, fmt: "cannot alloc expectation" ); |
477 | ret = NF_DROP; |
478 | goto out; |
479 | } |
480 | |
481 | /* We refer to the reverse direction ("!dir") tuples here, |
482 | * because we're expecting something in the other direction. |
483 | * Doesn't matter unless NAT is happening. */ |
484 | daddr = &ct->tuplehash[!dir].tuple.dst.u3; |
485 | |
486 | /* Update the ftp info */ |
487 | if ((cmd.l3num == nf_ct_l3num(ct)) && |
488 | memcmp(p: &cmd.u3.all, q: &ct->tuplehash[dir].tuple.src.u3.all, |
489 | size: sizeof(cmd.u3.all))) { |
490 | /* Enrico Scholz's passive FTP to partially RNAT'd ftp |
491 | server: it really wants us to connect to a |
492 | different IP address. Simply don't record it for |
493 | NAT. */ |
494 | if (cmd.l3num == PF_INET) { |
495 | pr_debug("NOT RECORDING: %pI4 != %pI4\n" , |
496 | &cmd.u3.ip, |
497 | &ct->tuplehash[dir].tuple.src.u3.ip); |
498 | } else { |
499 | pr_debug("NOT RECORDING: %pI6 != %pI6\n" , |
500 | cmd.u3.ip6, |
501 | ct->tuplehash[dir].tuple.src.u3.ip6); |
502 | } |
503 | |
504 | /* Thanks to Cristiano Lincoln Mattos |
505 | <lincoln@cesar.org.br> for reporting this potential |
506 | problem (DMZ machines opening holes to internal |
507 | networks, or the packet filter itself). */ |
508 | if (!loose) { |
509 | ret = NF_ACCEPT; |
510 | goto out_put_expect; |
511 | } |
512 | daddr = &cmd.u3; |
513 | } |
514 | |
515 | nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, cmd.l3num, |
516 | &ct->tuplehash[!dir].tuple.src.u3, daddr, |
517 | IPPROTO_TCP, NULL, &cmd.u.tcp.port); |
518 | |
519 | /* Now, NAT might want to mangle the packet, and register the |
520 | * (possibly changed) expectation itself. */ |
521 | nf_nat_ftp = rcu_dereference(nf_nat_ftp_hook); |
522 | if (nf_nat_ftp && ct->status & IPS_NAT_MASK) |
523 | ret = nf_nat_ftp(skb, ctinfo, search[dir][i].ftptype, |
524 | protoff, matchoff, matchlen, exp); |
525 | else { |
526 | /* Can't expect this? Best to drop packet now. */ |
527 | if (nf_ct_expect_related(expect: exp, flags: 0) != 0) { |
528 | nf_ct_helper_log(skb, ct, fmt: "cannot add expectation" ); |
529 | ret = NF_DROP; |
530 | } else |
531 | ret = NF_ACCEPT; |
532 | } |
533 | |
534 | out_put_expect: |
535 | nf_ct_expect_put(exp); |
536 | |
537 | out_update_nl: |
538 | /* Now if this ends in \n, update ftp info. Seq may have been |
539 | * adjusted by NAT code. */ |
540 | if (ends_in_nl) |
541 | update_nl_seq(ct, nl_seq: seq, info: ct_ftp_info, dir, skb); |
542 | out: |
543 | spin_unlock_bh(lock: &nf_ftp_lock); |
544 | return ret; |
545 | } |
546 | |
547 | static int nf_ct_ftp_from_nlattr(struct nlattr *attr, struct nf_conn *ct) |
548 | { |
549 | struct nf_ct_ftp_master *ftp = nfct_help_data(ct); |
550 | |
551 | /* This conntrack has been injected from user-space, always pick up |
552 | * sequence tracking. Otherwise, the first FTP command after the |
553 | * failover breaks. |
554 | */ |
555 | ftp->flags[IP_CT_DIR_ORIGINAL] |= NF_CT_FTP_SEQ_PICKUP; |
556 | ftp->flags[IP_CT_DIR_REPLY] |= NF_CT_FTP_SEQ_PICKUP; |
557 | return 0; |
558 | } |
559 | |
560 | static struct nf_conntrack_helper ftp[MAX_PORTS * 2] __read_mostly; |
561 | |
562 | static const struct nf_conntrack_expect_policy ftp_exp_policy = { |
563 | .max_expected = 1, |
564 | .timeout = 5 * 60, |
565 | }; |
566 | |
567 | static void __exit nf_conntrack_ftp_fini(void) |
568 | { |
569 | nf_conntrack_helpers_unregister(ftp, ports_c * 2); |
570 | } |
571 | |
572 | static int __init nf_conntrack_ftp_init(void) |
573 | { |
574 | int i, ret = 0; |
575 | |
576 | NF_CT_HELPER_BUILD_BUG_ON(sizeof(struct nf_ct_ftp_master)); |
577 | |
578 | if (ports_c == 0) |
579 | ports[ports_c++] = FTP_PORT; |
580 | |
581 | /* FIXME should be configurable whether IPv4 and IPv6 FTP connections |
582 | are tracked or not - YK */ |
583 | for (i = 0; i < ports_c; i++) { |
584 | nf_ct_helper_init(helper: &ftp[2 * i], AF_INET, IPPROTO_TCP, |
585 | HELPER_NAME, FTP_PORT, spec_port: ports[i], id: ports[i], |
586 | exp_pol: &ftp_exp_policy, expect_class_max: 0, help, |
587 | from_nlattr: nf_ct_ftp_from_nlattr, THIS_MODULE); |
588 | nf_ct_helper_init(helper: &ftp[2 * i + 1], AF_INET6, IPPROTO_TCP, |
589 | HELPER_NAME, FTP_PORT, spec_port: ports[i], id: ports[i], |
590 | exp_pol: &ftp_exp_policy, expect_class_max: 0, help, |
591 | from_nlattr: nf_ct_ftp_from_nlattr, THIS_MODULE); |
592 | } |
593 | |
594 | ret = nf_conntrack_helpers_register(ftp, ports_c * 2); |
595 | if (ret < 0) { |
596 | pr_err("failed to register helpers\n" ); |
597 | return ret; |
598 | } |
599 | |
600 | return 0; |
601 | } |
602 | |
603 | module_init(nf_conntrack_ftp_init); |
604 | module_exit(nf_conntrack_ftp_fini); |
605 | |