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Commit | Line | Data |
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9fb9cbb1 YK |
1 | /* FTP extension for connection tracking. */ |
2 | ||
3 | /* (C) 1999-2001 Paul `Rusty' Russell | |
4 | * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org> | |
5 | * (C) 2003,2004 USAGI/WIDE Project <http://www.linux-ipv6.org> | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License version 2 as | |
9 | * published by the Free Software Foundation. | |
10 | * | |
11 | * 16 Dec 2003: Yasuyuki Kozakai @USAGI <yasuyuki.kozakai@toshiba.co.jp> | |
12 | * - enable working with Layer 3 protocol independent connection tracking. | |
13 | * - track EPRT and EPSV commands with IPv6 address. | |
14 | * | |
15 | * Derived from net/ipv4/netfilter/ip_conntrack_ftp.c | |
16 | */ | |
17 | ||
9fb9cbb1 YK |
18 | #include <linux/module.h> |
19 | #include <linux/moduleparam.h> | |
20 | #include <linux/netfilter.h> | |
21 | #include <linux/ip.h> | |
22 | #include <linux/ipv6.h> | |
23 | #include <linux/ctype.h> | |
24 | #include <net/checksum.h> | |
25 | #include <net/tcp.h> | |
26 | ||
27 | #include <net/netfilter/nf_conntrack.h> | |
28 | #include <net/netfilter/nf_conntrack_helper.h> | |
29 | #include <linux/netfilter/nf_conntrack_ftp.h> | |
30 | ||
31 | MODULE_LICENSE("GPL"); | |
32 | MODULE_AUTHOR("Rusty Russell <rusty@rustcorp.com.au>"); | |
33 | MODULE_DESCRIPTION("ftp connection tracking helper"); | |
34 | ||
35 | /* This is slow, but it's simple. --RR */ | |
36 | static char *ftp_buffer; | |
37 | ||
38 | static DEFINE_SPINLOCK(nf_ftp_lock); | |
39 | ||
40 | #define MAX_PORTS 8 | |
41 | static u_int16_t ports[MAX_PORTS]; | |
42 | static unsigned int ports_c; | |
43 | module_param_array(ports, ushort, &ports_c, 0400); | |
44 | ||
45 | static int loose; | |
e7be6994 | 46 | module_param(loose, bool, 0600); |
9fb9cbb1 YK |
47 | |
48 | unsigned int (*nf_nat_ftp_hook)(struct sk_buff **pskb, | |
49 | enum ip_conntrack_info ctinfo, | |
50 | enum ip_ct_ftp_type type, | |
51 | unsigned int matchoff, | |
52 | unsigned int matchlen, | |
53 | struct nf_conntrack_expect *exp, | |
54 | u32 *seq); | |
55 | EXPORT_SYMBOL_GPL(nf_nat_ftp_hook); | |
56 | ||
57 | #if 0 | |
58 | #define DEBUGP printk | |
59 | #else | |
60 | #define DEBUGP(format, args...) | |
61 | #endif | |
62 | ||
63 | static int try_rfc959(const char *, size_t, struct nf_conntrack_man *, char); | |
64 | static int try_eprt(const char *, size_t, struct nf_conntrack_man *, char); | |
65 | static int try_epsv_response(const char *, size_t, struct nf_conntrack_man *, | |
66 | char); | |
67 | ||
68 | static struct ftp_search { | |
9fb9cbb1 YK |
69 | const char *pattern; |
70 | size_t plen; | |
71 | char skip; | |
72 | char term; | |
73 | enum ip_ct_ftp_type ftptype; | |
74 | int (*getnum)(const char *, size_t, struct nf_conntrack_man *, char); | |
7d8c5018 PM |
75 | } search[IP_CT_DIR_MAX][2] = { |
76 | [IP_CT_DIR_ORIGINAL] = { | |
77 | { | |
78 | .pattern = "PORT", | |
79 | .plen = sizeof("PORT") - 1, | |
80 | .skip = ' ', | |
81 | .term = '\r', | |
82 | .ftptype = IP_CT_FTP_PORT, | |
83 | .getnum = try_rfc959, | |
84 | }, | |
85 | { | |
86 | .pattern = "EPRT", | |
87 | .plen = sizeof("EPRT") - 1, | |
88 | .skip = ' ', | |
89 | .term = '\r', | |
90 | .ftptype = IP_CT_FTP_EPRT, | |
91 | .getnum = try_eprt, | |
92 | }, | |
9fb9cbb1 | 93 | }, |
7d8c5018 PM |
94 | [IP_CT_DIR_REPLY] = { |
95 | { | |
96 | .pattern = "227 ", | |
97 | .plen = sizeof("227 ") - 1, | |
98 | .skip = '(', | |
99 | .term = ')', | |
100 | .ftptype = IP_CT_FTP_PASV, | |
101 | .getnum = try_rfc959, | |
102 | }, | |
103 | { | |
104 | .pattern = "229 ", | |
105 | .plen = sizeof("229 ") - 1, | |
106 | .skip = '(', | |
107 | .term = ')', | |
108 | .ftptype = IP_CT_FTP_EPSV, | |
109 | .getnum = try_epsv_response, | |
110 | }, | |
9fb9cbb1 YK |
111 | }, |
112 | }; | |
113 | ||
9fb9cbb1 YK |
114 | static int |
115 | get_ipv6_addr(const char *src, size_t dlen, struct in6_addr *dst, u_int8_t term) | |
116 | { | |
1884f78c YH |
117 | int ret = in6_pton(src, min_t(size_t, dlen, 0xffff), dst, term, &end); |
118 | if (ret > 0) | |
119 | return (int)(end - src); | |
120 | return 0; | |
9fb9cbb1 YK |
121 | } |
122 | ||
123 | static int try_number(const char *data, size_t dlen, u_int32_t array[], | |
124 | int array_size, char sep, char term) | |
125 | { | |
126 | u_int32_t i, len; | |
127 | ||
128 | memset(array, 0, sizeof(array[0])*array_size); | |
129 | ||
130 | /* Keep data pointing at next char. */ | |
131 | for (i = 0, len = 0; len < dlen && i < array_size; len++, data++) { | |
132 | if (*data >= '0' && *data <= '9') { | |
133 | array[i] = array[i]*10 + *data - '0'; | |
134 | } | |
135 | else if (*data == sep) | |
136 | i++; | |
137 | else { | |
138 | /* Unexpected character; true if it's the | |
139 | terminator and we're finished. */ | |
140 | if (*data == term && i == array_size - 1) | |
141 | return len; | |
142 | ||
143 | DEBUGP("Char %u (got %u nums) `%u' unexpected\n", | |
144 | len, i, *data); | |
145 | return 0; | |
146 | } | |
147 | } | |
148 | DEBUGP("Failed to fill %u numbers separated by %c\n", array_size, sep); | |
149 | ||
150 | return 0; | |
151 | } | |
152 | ||
153 | /* Returns 0, or length of numbers: 192,168,1,1,5,6 */ | |
154 | static int try_rfc959(const char *data, size_t dlen, | |
155 | struct nf_conntrack_man *cmd, char term) | |
156 | { | |
157 | int length; | |
158 | u_int32_t array[6]; | |
159 | ||
160 | length = try_number(data, dlen, array, 6, ',', term); | |
161 | if (length == 0) | |
162 | return 0; | |
163 | ||
164 | cmd->u3.ip = htonl((array[0] << 24) | (array[1] << 16) | | |
165 | (array[2] << 8) | array[3]); | |
166 | cmd->u.tcp.port = htons((array[4] << 8) | array[5]); | |
167 | return length; | |
168 | } | |
169 | ||
170 | /* Grab port: number up to delimiter */ | |
171 | static int get_port(const char *data, int start, size_t dlen, char delim, | |
172 | u_int16_t *port) | |
173 | { | |
174 | u_int16_t tmp_port = 0; | |
175 | int i; | |
176 | ||
177 | for (i = start; i < dlen; i++) { | |
178 | /* Finished? */ | |
179 | if (data[i] == delim) { | |
180 | if (tmp_port == 0) | |
181 | break; | |
182 | *port = htons(tmp_port); | |
183 | DEBUGP("get_port: return %d\n", tmp_port); | |
184 | return i + 1; | |
185 | } | |
186 | else if (data[i] >= '0' && data[i] <= '9') | |
187 | tmp_port = tmp_port*10 + data[i] - '0'; | |
188 | else { /* Some other crap */ | |
189 | DEBUGP("get_port: invalid char.\n"); | |
190 | break; | |
191 | } | |
192 | } | |
193 | return 0; | |
194 | } | |
195 | ||
196 | /* Returns 0, or length of numbers: |1|132.235.1.2|6275| or |2|3ffe::1|6275| */ | |
197 | static int try_eprt(const char *data, size_t dlen, struct nf_conntrack_man *cmd, | |
198 | char term) | |
199 | { | |
200 | char delim; | |
201 | int length; | |
202 | ||
203 | /* First character is delimiter, then "1" for IPv4 or "2" for IPv6, | |
204 | then delimiter again. */ | |
205 | if (dlen <= 3) { | |
206 | DEBUGP("EPRT: too short\n"); | |
207 | return 0; | |
208 | } | |
209 | delim = data[0]; | |
210 | if (isdigit(delim) || delim < 33 || delim > 126 || data[2] != delim) { | |
211 | DEBUGP("try_eprt: invalid delimitter.\n"); | |
212 | return 0; | |
213 | } | |
214 | ||
215 | if ((cmd->l3num == PF_INET && data[1] != '1') || | |
216 | (cmd->l3num == PF_INET6 && data[1] != '2')) { | |
217 | DEBUGP("EPRT: invalid protocol number.\n"); | |
218 | return 0; | |
219 | } | |
220 | ||
221 | DEBUGP("EPRT: Got %c%c%c\n", delim, data[1], delim); | |
222 | ||
223 | if (data[1] == '1') { | |
224 | u_int32_t array[4]; | |
225 | ||
226 | /* Now we have IP address. */ | |
227 | length = try_number(data + 3, dlen - 3, array, 4, '.', delim); | |
228 | if (length != 0) | |
229 | cmd->u3.ip = htonl((array[0] << 24) | (array[1] << 16) | |
230 | | (array[2] << 8) | array[3]); | |
231 | } else { | |
232 | /* Now we have IPv6 address. */ | |
233 | length = get_ipv6_addr(data + 3, dlen - 3, | |
234 | (struct in6_addr *)cmd->u3.ip6, delim); | |
235 | } | |
236 | ||
237 | if (length == 0) | |
238 | return 0; | |
239 | DEBUGP("EPRT: Got IP address!\n"); | |
240 | /* Start offset includes initial "|1|", and trailing delimiter */ | |
241 | return get_port(data, 3 + length + 1, dlen, delim, &cmd->u.tcp.port); | |
242 | } | |
243 | ||
244 | /* Returns 0, or length of numbers: |||6446| */ | |
245 | static int try_epsv_response(const char *data, size_t dlen, | |
246 | struct nf_conntrack_man *cmd, char term) | |
247 | { | |
248 | char delim; | |
249 | ||
250 | /* Three delimiters. */ | |
251 | if (dlen <= 3) return 0; | |
252 | delim = data[0]; | |
253 | if (isdigit(delim) || delim < 33 || delim > 126 | |
254 | || data[1] != delim || data[2] != delim) | |
255 | return 0; | |
256 | ||
257 | return get_port(data, 3, dlen, delim, &cmd->u.tcp.port); | |
258 | } | |
259 | ||
260 | /* Return 1 for match, 0 for accept, -1 for partial. */ | |
261 | static int find_pattern(const char *data, size_t dlen, | |
262 | const char *pattern, size_t plen, | |
263 | char skip, char term, | |
264 | unsigned int *numoff, | |
265 | unsigned int *numlen, | |
266 | struct nf_conntrack_man *cmd, | |
267 | int (*getnum)(const char *, size_t, | |
268 | struct nf_conntrack_man *, char)) | |
269 | { | |
270 | size_t i; | |
271 | ||
272 | DEBUGP("find_pattern `%s': dlen = %u\n", pattern, dlen); | |
273 | if (dlen == 0) | |
274 | return 0; | |
275 | ||
276 | if (dlen <= plen) { | |
277 | /* Short packet: try for partial? */ | |
278 | if (strnicmp(data, pattern, dlen) == 0) | |
279 | return -1; | |
280 | else return 0; | |
281 | } | |
282 | ||
283 | if (strnicmp(data, pattern, plen) != 0) { | |
284 | #if 0 | |
285 | size_t i; | |
286 | ||
287 | DEBUGP("ftp: string mismatch\n"); | |
288 | for (i = 0; i < plen; i++) { | |
289 | DEBUGP("ftp:char %u `%c'(%u) vs `%c'(%u)\n", | |
290 | i, data[i], data[i], | |
291 | pattern[i], pattern[i]); | |
292 | } | |
293 | #endif | |
294 | return 0; | |
295 | } | |
296 | ||
297 | DEBUGP("Pattern matches!\n"); | |
298 | /* Now we've found the constant string, try to skip | |
299 | to the 'skip' character */ | |
300 | for (i = plen; data[i] != skip; i++) | |
301 | if (i == dlen - 1) return -1; | |
302 | ||
303 | /* Skip over the last character */ | |
304 | i++; | |
305 | ||
306 | DEBUGP("Skipped up to `%c'!\n", skip); | |
307 | ||
308 | *numoff = i; | |
309 | *numlen = getnum(data + i, dlen - i, cmd, term); | |
310 | if (!*numlen) | |
311 | return -1; | |
312 | ||
313 | DEBUGP("Match succeeded!\n"); | |
314 | return 1; | |
315 | } | |
316 | ||
317 | /* Look up to see if we're just after a \n. */ | |
318 | static int find_nl_seq(u32 seq, const struct ip_ct_ftp_master *info, int dir) | |
319 | { | |
320 | unsigned int i; | |
321 | ||
322 | for (i = 0; i < info->seq_aft_nl_num[dir]; i++) | |
323 | if (info->seq_aft_nl[dir][i] == seq) | |
324 | return 1; | |
325 | return 0; | |
326 | } | |
327 | ||
328 | /* We don't update if it's older than what we have. */ | |
329 | static void update_nl_seq(u32 nl_seq, struct ip_ct_ftp_master *info, int dir, | |
330 | struct sk_buff *skb) | |
331 | { | |
332 | unsigned int i, oldest = NUM_SEQ_TO_REMEMBER; | |
333 | ||
334 | /* Look for oldest: if we find exact match, we're done. */ | |
335 | for (i = 0; i < info->seq_aft_nl_num[dir]; i++) { | |
336 | if (info->seq_aft_nl[dir][i] == nl_seq) | |
337 | return; | |
338 | ||
339 | if (oldest == info->seq_aft_nl_num[dir] | |
340 | || before(info->seq_aft_nl[dir][i], oldest)) | |
341 | oldest = i; | |
342 | } | |
343 | ||
344 | if (info->seq_aft_nl_num[dir] < NUM_SEQ_TO_REMEMBER) { | |
345 | info->seq_aft_nl[dir][info->seq_aft_nl_num[dir]++] = nl_seq; | |
346 | nf_conntrack_event_cache(IPCT_HELPINFO_VOLATILE, skb); | |
347 | } else if (oldest != NUM_SEQ_TO_REMEMBER) { | |
348 | info->seq_aft_nl[dir][oldest] = nl_seq; | |
349 | nf_conntrack_event_cache(IPCT_HELPINFO_VOLATILE, skb); | |
350 | } | |
351 | } | |
352 | ||
353 | static int help(struct sk_buff **pskb, | |
354 | unsigned int protoff, | |
355 | struct nf_conn *ct, | |
356 | enum ip_conntrack_info ctinfo) | |
357 | { | |
358 | unsigned int dataoff, datalen; | |
359 | struct tcphdr _tcph, *th; | |
360 | char *fb_ptr; | |
361 | int ret; | |
362 | u32 seq; | |
363 | int dir = CTINFO2DIR(ctinfo); | |
364 | unsigned int matchlen, matchoff; | |
dc808fe2 | 365 | struct ip_ct_ftp_master *ct_ftp_info = &nfct_help(ct)->help.ct_ftp_info; |
9fb9cbb1 YK |
366 | struct nf_conntrack_expect *exp; |
367 | struct nf_conntrack_man cmd = {}; | |
368 | ||
369 | unsigned int i; | |
370 | int found = 0, ends_in_nl; | |
371 | ||
372 | /* Until there's been traffic both ways, don't look in packets. */ | |
373 | if (ctinfo != IP_CT_ESTABLISHED | |
374 | && ctinfo != IP_CT_ESTABLISHED+IP_CT_IS_REPLY) { | |
375 | DEBUGP("ftp: Conntrackinfo = %u\n", ctinfo); | |
376 | return NF_ACCEPT; | |
377 | } | |
378 | ||
379 | th = skb_header_pointer(*pskb, protoff, sizeof(_tcph), &_tcph); | |
380 | if (th == NULL) | |
381 | return NF_ACCEPT; | |
382 | ||
383 | dataoff = protoff + th->doff * 4; | |
384 | /* No data? */ | |
385 | if (dataoff >= (*pskb)->len) { | |
386 | DEBUGP("ftp: dataoff(%u) >= skblen(%u)\n", dataoff, | |
387 | (*pskb)->len); | |
388 | return NF_ACCEPT; | |
389 | } | |
390 | datalen = (*pskb)->len - dataoff; | |
391 | ||
392 | spin_lock_bh(&nf_ftp_lock); | |
393 | fb_ptr = skb_header_pointer(*pskb, dataoff, datalen, ftp_buffer); | |
394 | BUG_ON(fb_ptr == NULL); | |
395 | ||
396 | ends_in_nl = (fb_ptr[datalen - 1] == '\n'); | |
397 | seq = ntohl(th->seq) + datalen; | |
398 | ||
399 | /* Look up to see if we're just after a \n. */ | |
400 | if (!find_nl_seq(ntohl(th->seq), ct_ftp_info, dir)) { | |
401 | /* Now if this ends in \n, update ftp info. */ | |
402 | DEBUGP("nf_conntrack_ftp_help: wrong seq pos %s(%u) or %s(%u)\n", | |
403 | ct_ftp_info->seq_aft_nl_num[dir] > 0 ? "" : "(UNSET)", | |
404 | ct_ftp_info->seq_aft_nl[dir][0], | |
405 | ct_ftp_info->seq_aft_nl_num[dir] > 1 ? "" : "(UNSET)", | |
406 | ct_ftp_info->seq_aft_nl[dir][1]); | |
407 | ret = NF_ACCEPT; | |
408 | goto out_update_nl; | |
409 | } | |
410 | ||
411 | /* Initialize IP/IPv6 addr to expected address (it's not mentioned | |
412 | in EPSV responses) */ | |
413 | cmd.l3num = ct->tuplehash[dir].tuple.src.l3num; | |
414 | memcpy(cmd.u3.all, &ct->tuplehash[dir].tuple.src.u3.all, | |
415 | sizeof(cmd.u3.all)); | |
416 | ||
7d8c5018 | 417 | for (i = 0; i < ARRAY_SIZE(search[dir]); i++) { |
9fb9cbb1 | 418 | found = find_pattern(fb_ptr, datalen, |
7d8c5018 PM |
419 | search[dir][i].pattern, |
420 | search[dir][i].plen, | |
421 | search[dir][i].skip, | |
422 | search[dir][i].term, | |
9fb9cbb1 YK |
423 | &matchoff, &matchlen, |
424 | &cmd, | |
7d8c5018 | 425 | search[dir][i].getnum); |
9fb9cbb1 YK |
426 | if (found) break; |
427 | } | |
428 | if (found == -1) { | |
429 | /* We don't usually drop packets. After all, this is | |
430 | connection tracking, not packet filtering. | |
431 | However, it is necessary for accurate tracking in | |
432 | this case. */ | |
433 | if (net_ratelimit()) | |
434 | printk("conntrack_ftp: partial %s %u+%u\n", | |
7d8c5018 | 435 | search[dir][i].pattern, |
9fb9cbb1 YK |
436 | ntohl(th->seq), datalen); |
437 | ret = NF_DROP; | |
438 | goto out; | |
439 | } else if (found == 0) { /* No match */ | |
440 | ret = NF_ACCEPT; | |
441 | goto out_update_nl; | |
442 | } | |
443 | ||
444 | DEBUGP("conntrack_ftp: match `%.*s' (%u bytes at %u)\n", | |
445 | (int)matchlen, fb_ptr + matchoff, | |
446 | matchlen, ntohl(th->seq) + matchoff); | |
447 | ||
448 | exp = nf_conntrack_expect_alloc(ct); | |
449 | if (exp == NULL) { | |
450 | ret = NF_DROP; | |
451 | goto out; | |
452 | } | |
453 | ||
454 | /* We refer to the reverse direction ("!dir") tuples here, | |
455 | * because we're expecting something in the other direction. | |
456 | * Doesn't matter unless NAT is happening. */ | |
457 | exp->tuple.dst.u3 = ct->tuplehash[!dir].tuple.dst.u3; | |
458 | ||
459 | /* Update the ftp info */ | |
460 | if ((cmd.l3num == ct->tuplehash[dir].tuple.src.l3num) && | |
461 | memcmp(&cmd.u3.all, &ct->tuplehash[dir].tuple.src.u3.all, | |
462 | sizeof(cmd.u3.all))) { | |
463 | /* Enrico Scholz's passive FTP to partially RNAT'd ftp | |
464 | server: it really wants us to connect to a | |
465 | different IP address. Simply don't record it for | |
466 | NAT. */ | |
467 | if (cmd.l3num == PF_INET) { | |
46b86a2d | 468 | DEBUGP("conntrack_ftp: NOT RECORDING: " NIPQUAD_FMT " != " NIPQUAD_FMT "\n", |
9fb9cbb1 YK |
469 | NIPQUAD(cmd.u3.ip), |
470 | NIPQUAD(ct->tuplehash[dir].tuple.src.u3.ip)); | |
471 | } else { | |
46b86a2d | 472 | DEBUGP("conntrack_ftp: NOT RECORDING: " NIP6_FMT " != " NIP6_FMT "\n", |
9fb9cbb1 YK |
473 | NIP6(*((struct in6_addr *)cmd.u3.ip6)), |
474 | NIP6(*((struct in6_addr *)ct->tuplehash[dir] | |
475 | .tuple.src.u3.ip6))); | |
476 | } | |
477 | ||
478 | /* Thanks to Cristiano Lincoln Mattos | |
479 | <lincoln@cesar.org.br> for reporting this potential | |
480 | problem (DMZ machines opening holes to internal | |
481 | networks, or the packet filter itself). */ | |
482 | if (!loose) { | |
483 | ret = NF_ACCEPT; | |
484 | goto out_put_expect; | |
485 | } | |
486 | memcpy(&exp->tuple.dst.u3, &cmd.u3.all, | |
487 | sizeof(exp->tuple.dst.u3)); | |
488 | } | |
489 | ||
490 | exp->tuple.src.u3 = ct->tuplehash[!dir].tuple.src.u3; | |
491 | exp->tuple.src.l3num = cmd.l3num; | |
492 | exp->tuple.src.u.tcp.port = 0; | |
493 | exp->tuple.dst.u.tcp.port = cmd.u.tcp.port; | |
494 | exp->tuple.dst.protonum = IPPROTO_TCP; | |
495 | ||
496 | exp->mask = (struct nf_conntrack_tuple) | |
497 | { .src = { .l3num = 0xFFFF, | |
498 | .u = { .tcp = { 0 }}, | |
499 | }, | |
500 | .dst = { .protonum = 0xFF, | |
501 | .u = { .tcp = { 0xFFFF }}, | |
502 | }, | |
503 | }; | |
504 | if (cmd.l3num == PF_INET) { | |
505 | exp->mask.src.u3.ip = 0xFFFFFFFF; | |
506 | exp->mask.dst.u3.ip = 0xFFFFFFFF; | |
507 | } else { | |
508 | memset(exp->mask.src.u3.ip6, 0xFF, | |
509 | sizeof(exp->mask.src.u3.ip6)); | |
510 | memset(exp->mask.dst.u3.ip6, 0xFF, | |
511 | sizeof(exp->mask.src.u3.ip6)); | |
512 | } | |
513 | ||
514 | exp->expectfn = NULL; | |
515 | exp->flags = 0; | |
516 | ||
517 | /* Now, NAT might want to mangle the packet, and register the | |
518 | * (possibly changed) expectation itself. */ | |
519 | if (nf_nat_ftp_hook) | |
7d8c5018 | 520 | ret = nf_nat_ftp_hook(pskb, ctinfo, search[dir][i].ftptype, |
9fb9cbb1 YK |
521 | matchoff, matchlen, exp, &seq); |
522 | else { | |
523 | /* Can't expect this? Best to drop packet now. */ | |
524 | if (nf_conntrack_expect_related(exp) != 0) | |
525 | ret = NF_DROP; | |
526 | else | |
527 | ret = NF_ACCEPT; | |
528 | } | |
529 | ||
530 | out_put_expect: | |
531 | nf_conntrack_expect_put(exp); | |
532 | ||
533 | out_update_nl: | |
534 | /* Now if this ends in \n, update ftp info. Seq may have been | |
535 | * adjusted by NAT code. */ | |
536 | if (ends_in_nl) | |
537 | update_nl_seq(seq, ct_ftp_info, dir, *pskb); | |
538 | out: | |
539 | spin_unlock_bh(&nf_ftp_lock); | |
540 | return ret; | |
541 | } | |
542 | ||
543 | static struct nf_conntrack_helper ftp[MAX_PORTS][2]; | |
544 | static char ftp_names[MAX_PORTS][2][sizeof("ftp-65535")]; | |
545 | ||
546 | /* don't make this __exit, since it's called from __init ! */ | |
65b4b4e8 | 547 | static void nf_conntrack_ftp_fini(void) |
9fb9cbb1 YK |
548 | { |
549 | int i, j; | |
550 | for (i = 0; i < ports_c; i++) { | |
551 | for (j = 0; j < 2; j++) { | |
552 | if (ftp[i][j].me == NULL) | |
553 | continue; | |
554 | ||
555 | DEBUGP("nf_ct_ftp: unregistering helper for pf: %d " | |
556 | "port: %d\n", | |
557 | ftp[i][j].tuple.src.l3num, ports[i]); | |
558 | nf_conntrack_helper_unregister(&ftp[i][j]); | |
559 | } | |
560 | } | |
561 | ||
562 | kfree(ftp_buffer); | |
563 | } | |
564 | ||
65b4b4e8 | 565 | static int __init nf_conntrack_ftp_init(void) |
9fb9cbb1 YK |
566 | { |
567 | int i, j = -1, ret = 0; | |
568 | char *tmpname; | |
569 | ||
570 | ftp_buffer = kmalloc(65536, GFP_KERNEL); | |
571 | if (!ftp_buffer) | |
572 | return -ENOMEM; | |
573 | ||
574 | if (ports_c == 0) | |
575 | ports[ports_c++] = FTP_PORT; | |
576 | ||
577 | /* FIXME should be configurable whether IPv4 and IPv6 FTP connections | |
578 | are tracked or not - YK */ | |
579 | for (i = 0; i < ports_c; i++) { | |
9fb9cbb1 YK |
580 | ftp[i][0].tuple.src.l3num = PF_INET; |
581 | ftp[i][1].tuple.src.l3num = PF_INET6; | |
582 | for (j = 0; j < 2; j++) { | |
583 | ftp[i][j].tuple.src.u.tcp.port = htons(ports[i]); | |
584 | ftp[i][j].tuple.dst.protonum = IPPROTO_TCP; | |
585 | ftp[i][j].mask.src.u.tcp.port = 0xFFFF; | |
586 | ftp[i][j].mask.dst.protonum = 0xFF; | |
587 | ftp[i][j].max_expected = 1; | |
588 | ftp[i][j].timeout = 5 * 60; /* 5 Minutes */ | |
589 | ftp[i][j].me = THIS_MODULE; | |
590 | ftp[i][j].help = help; | |
591 | tmpname = &ftp_names[i][j][0]; | |
592 | if (ports[i] == FTP_PORT) | |
593 | sprintf(tmpname, "ftp"); | |
594 | else | |
595 | sprintf(tmpname, "ftp-%d", ports[i]); | |
596 | ftp[i][j].name = tmpname; | |
597 | ||
598 | DEBUGP("nf_ct_ftp: registering helper for pf: %d " | |
599 | "port: %d\n", | |
600 | ftp[i][j].tuple.src.l3num, ports[i]); | |
601 | ret = nf_conntrack_helper_register(&ftp[i][j]); | |
602 | if (ret) { | |
603 | printk("nf_ct_ftp: failed to register helper " | |
604 | " for pf: %d port: %d\n", | |
605 | ftp[i][j].tuple.src.l3num, ports[i]); | |
65b4b4e8 | 606 | nf_conntrack_ftp_fini(); |
9fb9cbb1 YK |
607 | return ret; |
608 | } | |
609 | } | |
610 | } | |
611 | ||
612 | return 0; | |
613 | } | |
614 | ||
65b4b4e8 AM |
615 | module_init(nf_conntrack_ftp_init); |
616 | module_exit(nf_conntrack_ftp_fini); |