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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. | |
9fb9cbb1 YK |
10 | */ |
11 | ||
9fb9cbb1 YK |
12 | #include <linux/module.h> |
13 | #include <linux/moduleparam.h> | |
14 | #include <linux/netfilter.h> | |
15 | #include <linux/ip.h> | |
16 | #include <linux/ipv6.h> | |
17 | #include <linux/ctype.h> | |
6a28ec8c | 18 | #include <linux/inet.h> |
9fb9cbb1 YK |
19 | #include <net/checksum.h> |
20 | #include <net/tcp.h> | |
21 | ||
22 | #include <net/netfilter/nf_conntrack.h> | |
77ab9cff | 23 | #include <net/netfilter/nf_conntrack_expect.h> |
f6180121 | 24 | #include <net/netfilter/nf_conntrack_ecache.h> |
9fb9cbb1 YK |
25 | #include <net/netfilter/nf_conntrack_helper.h> |
26 | #include <linux/netfilter/nf_conntrack_ftp.h> | |
27 | ||
28 | MODULE_LICENSE("GPL"); | |
29 | MODULE_AUTHOR("Rusty Russell <rusty@rustcorp.com.au>"); | |
30 | MODULE_DESCRIPTION("ftp connection tracking helper"); | |
d2483dde | 31 | MODULE_ALIAS("ip_conntrack_ftp"); |
9fb9cbb1 YK |
32 | |
33 | /* This is slow, but it's simple. --RR */ | |
34 | static char *ftp_buffer; | |
35 | ||
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 int loose; | |
e7be6994 | 44 | module_param(loose, bool, 0600); |
9fb9cbb1 YK |
45 | |
46 | unsigned int (*nf_nat_ftp_hook)(struct sk_buff **pskb, | |
47 | enum ip_conntrack_info ctinfo, | |
55a73324 | 48 | enum nf_ct_ftp_type type, |
9fb9cbb1 YK |
49 | unsigned int matchoff, |
50 | unsigned int matchlen, | |
25b86e05 | 51 | struct nf_conntrack_expect *exp); |
9fb9cbb1 YK |
52 | EXPORT_SYMBOL_GPL(nf_nat_ftp_hook); |
53 | ||
54 | #if 0 | |
55 | #define DEBUGP printk | |
56 | #else | |
57 | #define DEBUGP(format, args...) | |
58 | #endif | |
59 | ||
60 | static int try_rfc959(const char *, size_t, struct nf_conntrack_man *, char); | |
61 | static int try_eprt(const char *, size_t, struct nf_conntrack_man *, char); | |
62 | static int try_epsv_response(const char *, size_t, struct nf_conntrack_man *, | |
63 | char); | |
64 | ||
65 | static struct ftp_search { | |
9fb9cbb1 YK |
66 | const char *pattern; |
67 | size_t plen; | |
68 | char skip; | |
69 | char term; | |
55a73324 | 70 | enum nf_ct_ftp_type ftptype; |
9fb9cbb1 | 71 | int (*getnum)(const char *, size_t, struct nf_conntrack_man *, char); |
7d8c5018 PM |
72 | } search[IP_CT_DIR_MAX][2] = { |
73 | [IP_CT_DIR_ORIGINAL] = { | |
74 | { | |
75 | .pattern = "PORT", | |
76 | .plen = sizeof("PORT") - 1, | |
77 | .skip = ' ', | |
78 | .term = '\r', | |
55a73324 | 79 | .ftptype = NF_CT_FTP_PORT, |
7d8c5018 PM |
80 | .getnum = try_rfc959, |
81 | }, | |
82 | { | |
83 | .pattern = "EPRT", | |
84 | .plen = sizeof("EPRT") - 1, | |
85 | .skip = ' ', | |
86 | .term = '\r', | |
55a73324 | 87 | .ftptype = NF_CT_FTP_EPRT, |
7d8c5018 PM |
88 | .getnum = try_eprt, |
89 | }, | |
9fb9cbb1 | 90 | }, |
7d8c5018 PM |
91 | [IP_CT_DIR_REPLY] = { |
92 | { | |
93 | .pattern = "227 ", | |
94 | .plen = sizeof("227 ") - 1, | |
95 | .skip = '(', | |
96 | .term = ')', | |
55a73324 | 97 | .ftptype = NF_CT_FTP_PASV, |
7d8c5018 PM |
98 | .getnum = try_rfc959, |
99 | }, | |
100 | { | |
101 | .pattern = "229 ", | |
102 | .plen = sizeof("229 ") - 1, | |
103 | .skip = '(', | |
104 | .term = ')', | |
55a73324 | 105 | .ftptype = NF_CT_FTP_EPSV, |
7d8c5018 PM |
106 | .getnum = try_epsv_response, |
107 | }, | |
9fb9cbb1 YK |
108 | }, |
109 | }; | |
110 | ||
9fb9cbb1 YK |
111 | static int |
112 | get_ipv6_addr(const char *src, size_t dlen, struct in6_addr *dst, u_int8_t term) | |
113 | { | |
6a28ec8c DM |
114 | const char *end; |
115 | int ret = in6_pton(src, min_t(size_t, dlen, 0xffff), (u8 *)dst, term, &end); | |
1884f78c YH |
116 | if (ret > 0) |
117 | return (int)(end - src); | |
118 | return 0; | |
9fb9cbb1 YK |
119 | } |
120 | ||
121 | static int try_number(const char *data, size_t dlen, u_int32_t array[], | |
601e68e1 | 122 | int array_size, char sep, char term) |
9fb9cbb1 YK |
123 | { |
124 | u_int32_t i, len; | |
125 | ||
126 | memset(array, 0, sizeof(array[0])*array_size); | |
127 | ||
128 | /* Keep data pointing at next char. */ | |
129 | for (i = 0, len = 0; len < dlen && i < array_size; len++, data++) { | |
130 | if (*data >= '0' && *data <= '9') { | |
131 | array[i] = array[i]*10 + *data - '0'; | |
132 | } | |
133 | else if (*data == sep) | |
134 | i++; | |
135 | else { | |
136 | /* Unexpected character; true if it's the | |
137 | terminator and we're finished. */ | |
138 | if (*data == term && i == array_size - 1) | |
139 | return len; | |
140 | ||
141 | DEBUGP("Char %u (got %u nums) `%u' unexpected\n", | |
142 | len, i, *data); | |
143 | return 0; | |
144 | } | |
145 | } | |
146 | DEBUGP("Failed to fill %u numbers separated by %c\n", array_size, sep); | |
147 | ||
148 | return 0; | |
149 | } | |
150 | ||
151 | /* Returns 0, or length of numbers: 192,168,1,1,5,6 */ | |
152 | static int try_rfc959(const char *data, size_t dlen, | |
153 | struct nf_conntrack_man *cmd, char term) | |
154 | { | |
155 | int length; | |
156 | u_int32_t array[6]; | |
157 | ||
158 | length = try_number(data, dlen, array, 6, ',', term); | |
159 | if (length == 0) | |
160 | return 0; | |
161 | ||
162 | cmd->u3.ip = htonl((array[0] << 24) | (array[1] << 16) | | |
163 | (array[2] << 8) | array[3]); | |
164 | cmd->u.tcp.port = htons((array[4] << 8) | array[5]); | |
165 | return length; | |
166 | } | |
167 | ||
168 | /* Grab port: number up to delimiter */ | |
169 | static int get_port(const char *data, int start, size_t dlen, char delim, | |
bff9a89b | 170 | __be16 *port) |
9fb9cbb1 YK |
171 | { |
172 | u_int16_t tmp_port = 0; | |
173 | int i; | |
174 | ||
175 | for (i = start; i < dlen; i++) { | |
176 | /* Finished? */ | |
177 | if (data[i] == delim) { | |
178 | if (tmp_port == 0) | |
179 | break; | |
180 | *port = htons(tmp_port); | |
181 | DEBUGP("get_port: return %d\n", tmp_port); | |
182 | return i + 1; | |
183 | } | |
184 | else if (data[i] >= '0' && data[i] <= '9') | |
185 | tmp_port = tmp_port*10 + data[i] - '0'; | |
186 | else { /* Some other crap */ | |
187 | DEBUGP("get_port: invalid char.\n"); | |
188 | break; | |
189 | } | |
190 | } | |
191 | return 0; | |
192 | } | |
193 | ||
194 | /* Returns 0, or length of numbers: |1|132.235.1.2|6275| or |2|3ffe::1|6275| */ | |
195 | static int try_eprt(const char *data, size_t dlen, struct nf_conntrack_man *cmd, | |
196 | char term) | |
197 | { | |
198 | char delim; | |
199 | int length; | |
200 | ||
201 | /* First character is delimiter, then "1" for IPv4 or "2" for IPv6, | |
202 | then delimiter again. */ | |
203 | if (dlen <= 3) { | |
204 | DEBUGP("EPRT: too short\n"); | |
205 | return 0; | |
206 | } | |
207 | delim = data[0]; | |
208 | if (isdigit(delim) || delim < 33 || delim > 126 || data[2] != delim) { | |
209 | DEBUGP("try_eprt: invalid delimitter.\n"); | |
210 | return 0; | |
211 | } | |
212 | ||
213 | if ((cmd->l3num == PF_INET && data[1] != '1') || | |
214 | (cmd->l3num == PF_INET6 && data[1] != '2')) { | |
215 | DEBUGP("EPRT: invalid protocol number.\n"); | |
216 | return 0; | |
217 | } | |
218 | ||
219 | DEBUGP("EPRT: Got %c%c%c\n", delim, data[1], delim); | |
220 | ||
221 | if (data[1] == '1') { | |
222 | u_int32_t array[4]; | |
223 | ||
224 | /* Now we have IP address. */ | |
225 | length = try_number(data + 3, dlen - 3, array, 4, '.', delim); | |
226 | if (length != 0) | |
227 | cmd->u3.ip = htonl((array[0] << 24) | (array[1] << 16) | |
228 | | (array[2] << 8) | array[3]); | |
229 | } else { | |
230 | /* Now we have IPv6 address. */ | |
231 | length = get_ipv6_addr(data + 3, dlen - 3, | |
232 | (struct in6_addr *)cmd->u3.ip6, delim); | |
233 | } | |
234 | ||
235 | if (length == 0) | |
236 | return 0; | |
237 | DEBUGP("EPRT: Got IP address!\n"); | |
238 | /* Start offset includes initial "|1|", and trailing delimiter */ | |
239 | return get_port(data, 3 + length + 1, dlen, delim, &cmd->u.tcp.port); | |
240 | } | |
241 | ||
242 | /* Returns 0, or length of numbers: |||6446| */ | |
243 | static int try_epsv_response(const char *data, size_t dlen, | |
244 | struct nf_conntrack_man *cmd, char term) | |
245 | { | |
246 | char delim; | |
247 | ||
248 | /* Three delimiters. */ | |
249 | if (dlen <= 3) return 0; | |
250 | delim = data[0]; | |
251 | if (isdigit(delim) || delim < 33 || delim > 126 | |
252 | || data[1] != delim || data[2] != delim) | |
253 | return 0; | |
254 | ||
255 | return get_port(data, 3, dlen, delim, &cmd->u.tcp.port); | |
256 | } | |
257 | ||
258 | /* Return 1 for match, 0 for accept, -1 for partial. */ | |
259 | static int find_pattern(const char *data, size_t dlen, | |
260 | const char *pattern, size_t plen, | |
261 | char skip, char term, | |
262 | unsigned int *numoff, | |
263 | unsigned int *numlen, | |
264 | struct nf_conntrack_man *cmd, | |
265 | int (*getnum)(const char *, size_t, | |
266 | struct nf_conntrack_man *, char)) | |
267 | { | |
268 | size_t i; | |
269 | ||
270 | DEBUGP("find_pattern `%s': dlen = %u\n", pattern, dlen); | |
271 | if (dlen == 0) | |
272 | return 0; | |
273 | ||
274 | if (dlen <= plen) { | |
275 | /* Short packet: try for partial? */ | |
276 | if (strnicmp(data, pattern, dlen) == 0) | |
277 | return -1; | |
278 | else return 0; | |
279 | } | |
280 | ||
281 | if (strnicmp(data, pattern, plen) != 0) { | |
282 | #if 0 | |
283 | size_t i; | |
284 | ||
285 | DEBUGP("ftp: string mismatch\n"); | |
286 | for (i = 0; i < plen; i++) { | |
287 | DEBUGP("ftp:char %u `%c'(%u) vs `%c'(%u)\n", | |
288 | i, data[i], data[i], | |
289 | pattern[i], pattern[i]); | |
290 | } | |
291 | #endif | |
292 | return 0; | |
293 | } | |
294 | ||
295 | DEBUGP("Pattern matches!\n"); | |
296 | /* Now we've found the constant string, try to skip | |
297 | to the 'skip' character */ | |
298 | for (i = plen; data[i] != skip; i++) | |
299 | if (i == dlen - 1) return -1; | |
300 | ||
301 | /* Skip over the last character */ | |
302 | i++; | |
303 | ||
304 | DEBUGP("Skipped up to `%c'!\n", skip); | |
305 | ||
306 | *numoff = i; | |
307 | *numlen = getnum(data + i, dlen - i, cmd, term); | |
308 | if (!*numlen) | |
309 | return -1; | |
310 | ||
311 | DEBUGP("Match succeeded!\n"); | |
312 | return 1; | |
313 | } | |
314 | ||
315 | /* Look up to see if we're just after a \n. */ | |
55a73324 | 316 | static int find_nl_seq(u32 seq, const struct nf_ct_ftp_master *info, int dir) |
9fb9cbb1 YK |
317 | { |
318 | unsigned int i; | |
319 | ||
320 | for (i = 0; i < info->seq_aft_nl_num[dir]; i++) | |
321 | if (info->seq_aft_nl[dir][i] == seq) | |
322 | return 1; | |
323 | return 0; | |
324 | } | |
325 | ||
326 | /* We don't update if it's older than what we have. */ | |
55a73324 | 327 | static void update_nl_seq(u32 nl_seq, struct nf_ct_ftp_master *info, int dir, |
9fb9cbb1 YK |
328 | struct sk_buff *skb) |
329 | { | |
330 | unsigned int i, oldest = NUM_SEQ_TO_REMEMBER; | |
331 | ||
332 | /* Look for oldest: if we find exact match, we're done. */ | |
333 | for (i = 0; i < info->seq_aft_nl_num[dir]; i++) { | |
334 | if (info->seq_aft_nl[dir][i] == nl_seq) | |
335 | return; | |
336 | ||
5fe26f53 PM |
337 | if (oldest == info->seq_aft_nl_num[dir] || |
338 | before(info->seq_aft_nl[dir][i], | |
339 | info->seq_aft_nl[dir][oldest])) | |
9fb9cbb1 YK |
340 | oldest = i; |
341 | } | |
342 | ||
343 | if (info->seq_aft_nl_num[dir] < NUM_SEQ_TO_REMEMBER) { | |
344 | info->seq_aft_nl[dir][info->seq_aft_nl_num[dir]++] = nl_seq; | |
345 | nf_conntrack_event_cache(IPCT_HELPINFO_VOLATILE, skb); | |
5fe26f53 PM |
346 | } else if (oldest != NUM_SEQ_TO_REMEMBER && |
347 | after(nl_seq, info->seq_aft_nl[dir][oldest])) { | |
9fb9cbb1 YK |
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; | |
55a73324 | 365 | struct nf_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 = {}; | |
9fb9cbb1 YK |
368 | unsigned int i; |
369 | int found = 0, ends_in_nl; | |
337fbc41 | 370 | typeof(nf_nat_ftp_hook) nf_nat_ftp; |
9fb9cbb1 YK |
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 | ||
601e68e1 YH |
411 | /* Initialize IP/IPv6 addr to expected address (it's not mentioned |
412 | in EPSV responses) */ | |
9fb9cbb1 YK |
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 | ||
6823645d | 448 | exp = nf_ct_expect_alloc(ct); |
9fb9cbb1 YK |
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 | |
601e68e1 YH |
464 | server: it really wants us to connect to a |
465 | different IP address. Simply don't record it for | |
466 | NAT. */ | |
9fb9cbb1 | 467 | if (cmd.l3num == PF_INET) { |
601e68e1 | 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, | |
bff9a89b | 501 | .u = { .tcp = { __constant_htons(0xFFFF) }}, |
9fb9cbb1 YK |
502 | }, |
503 | }; | |
504 | if (cmd.l3num == PF_INET) { | |
bff9a89b PM |
505 | exp->mask.src.u3.ip = htonl(0xFFFFFFFF); |
506 | exp->mask.dst.u3.ip = htonl(0xFFFFFFFF); | |
9fb9cbb1 YK |
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; | |
9457d851 | 515 | exp->helper = NULL; |
9fb9cbb1 YK |
516 | exp->flags = 0; |
517 | ||
518 | /* Now, NAT might want to mangle the packet, and register the | |
519 | * (possibly changed) expectation itself. */ | |
337fbc41 | 520 | nf_nat_ftp = rcu_dereference(nf_nat_ftp_hook); |
55a73324 | 521 | if (nf_nat_ftp && ct->status & IPS_NAT_MASK) |
337fbc41 | 522 | ret = nf_nat_ftp(pskb, ctinfo, search[dir][i].ftptype, |
25b86e05 | 523 | matchoff, matchlen, exp); |
9fb9cbb1 YK |
524 | else { |
525 | /* Can't expect this? Best to drop packet now. */ | |
6823645d | 526 | if (nf_ct_expect_related(exp) != 0) |
9fb9cbb1 YK |
527 | ret = NF_DROP; |
528 | else | |
529 | ret = NF_ACCEPT; | |
530 | } | |
531 | ||
532 | out_put_expect: | |
6823645d | 533 | nf_ct_expect_put(exp); |
9fb9cbb1 YK |
534 | |
535 | out_update_nl: | |
536 | /* Now if this ends in \n, update ftp info. Seq may have been | |
537 | * adjusted by NAT code. */ | |
538 | if (ends_in_nl) | |
539 | update_nl_seq(seq, ct_ftp_info, dir, *pskb); | |
540 | out: | |
541 | spin_unlock_bh(&nf_ftp_lock); | |
542 | return ret; | |
543 | } | |
544 | ||
545 | static struct nf_conntrack_helper ftp[MAX_PORTS][2]; | |
546 | static char ftp_names[MAX_PORTS][2][sizeof("ftp-65535")]; | |
547 | ||
548 | /* don't make this __exit, since it's called from __init ! */ | |
65b4b4e8 | 549 | static void nf_conntrack_ftp_fini(void) |
9fb9cbb1 YK |
550 | { |
551 | int i, j; | |
552 | for (i = 0; i < ports_c; i++) { | |
553 | for (j = 0; j < 2; j++) { | |
554 | if (ftp[i][j].me == NULL) | |
555 | continue; | |
556 | ||
557 | DEBUGP("nf_ct_ftp: unregistering helper for pf: %d " | |
558 | "port: %d\n", | |
559 | ftp[i][j].tuple.src.l3num, ports[i]); | |
560 | nf_conntrack_helper_unregister(&ftp[i][j]); | |
561 | } | |
562 | } | |
563 | ||
564 | kfree(ftp_buffer); | |
565 | } | |
566 | ||
65b4b4e8 | 567 | static int __init nf_conntrack_ftp_init(void) |
9fb9cbb1 YK |
568 | { |
569 | int i, j = -1, ret = 0; | |
570 | char *tmpname; | |
571 | ||
572 | ftp_buffer = kmalloc(65536, GFP_KERNEL); | |
573 | if (!ftp_buffer) | |
574 | return -ENOMEM; | |
575 | ||
576 | if (ports_c == 0) | |
577 | ports[ports_c++] = FTP_PORT; | |
578 | ||
579 | /* FIXME should be configurable whether IPv4 and IPv6 FTP connections | |
580 | are tracked or not - YK */ | |
581 | for (i = 0; i < ports_c; i++) { | |
9fb9cbb1 YK |
582 | ftp[i][0].tuple.src.l3num = PF_INET; |
583 | ftp[i][1].tuple.src.l3num = PF_INET6; | |
584 | for (j = 0; j < 2; j++) { | |
585 | ftp[i][j].tuple.src.u.tcp.port = htons(ports[i]); | |
586 | ftp[i][j].tuple.dst.protonum = IPPROTO_TCP; | |
d7346853 | 587 | ftp[i][j].mask.src.l3num = 0xFFFF; |
bff9a89b | 588 | ftp[i][j].mask.src.u.tcp.port = htons(0xFFFF); |
9fb9cbb1 YK |
589 | ftp[i][j].mask.dst.protonum = 0xFF; |
590 | ftp[i][j].max_expected = 1; | |
591 | ftp[i][j].timeout = 5 * 60; /* 5 Minutes */ | |
592 | ftp[i][j].me = THIS_MODULE; | |
593 | ftp[i][j].help = help; | |
594 | tmpname = &ftp_names[i][j][0]; | |
595 | if (ports[i] == FTP_PORT) | |
596 | sprintf(tmpname, "ftp"); | |
597 | else | |
598 | sprintf(tmpname, "ftp-%d", ports[i]); | |
599 | ftp[i][j].name = tmpname; | |
600 | ||
601 | DEBUGP("nf_ct_ftp: registering helper for pf: %d " | |
602 | "port: %d\n", | |
603 | ftp[i][j].tuple.src.l3num, ports[i]); | |
604 | ret = nf_conntrack_helper_register(&ftp[i][j]); | |
605 | if (ret) { | |
606 | printk("nf_ct_ftp: failed to register helper " | |
607 | " for pf: %d port: %d\n", | |
608 | ftp[i][j].tuple.src.l3num, ports[i]); | |
65b4b4e8 | 609 | nf_conntrack_ftp_fini(); |
9fb9cbb1 YK |
610 | return ret; |
611 | } | |
612 | } | |
613 | } | |
614 | ||
615 | return 0; | |
616 | } | |
617 | ||
65b4b4e8 AM |
618 | module_init(nf_conntrack_ftp_init); |
619 | module_exit(nf_conntrack_ftp_fini); |