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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"); |
4dc06f96 | 32 | MODULE_ALIAS_NFCT_HELPER("ftp"); |
9fb9cbb1 YK |
33 | |
34 | /* This is slow, but it's simple. --RR */ | |
35 | static char *ftp_buffer; | |
36 | ||
37 | static DEFINE_SPINLOCK(nf_ftp_lock); | |
38 | ||
39 | #define MAX_PORTS 8 | |
40 | static u_int16_t ports[MAX_PORTS]; | |
41 | static unsigned int ports_c; | |
42 | module_param_array(ports, ushort, &ports_c, 0400); | |
43 | ||
44 | static int loose; | |
e7be6994 | 45 | module_param(loose, bool, 0600); |
9fb9cbb1 | 46 | |
3db05fea | 47 | unsigned int (*nf_nat_ftp_hook)(struct sk_buff *skb, |
9fb9cbb1 | 48 | enum ip_conntrack_info ctinfo, |
55a73324 | 49 | enum nf_ct_ftp_type type, |
9fb9cbb1 YK |
50 | unsigned int matchoff, |
51 | unsigned int matchlen, | |
25b86e05 | 52 | struct nf_conntrack_expect *exp); |
9fb9cbb1 YK |
53 | EXPORT_SYMBOL_GPL(nf_nat_ftp_hook); |
54 | ||
9fb9cbb1 YK |
55 | static int try_rfc959(const char *, size_t, struct nf_conntrack_man *, char); |
56 | static int try_eprt(const char *, size_t, struct nf_conntrack_man *, char); | |
57 | static int try_epsv_response(const char *, size_t, struct nf_conntrack_man *, | |
58 | char); | |
59 | ||
60 | static struct ftp_search { | |
9fb9cbb1 YK |
61 | const char *pattern; |
62 | size_t plen; | |
63 | char skip; | |
64 | char term; | |
55a73324 | 65 | enum nf_ct_ftp_type ftptype; |
9fb9cbb1 | 66 | int (*getnum)(const char *, size_t, struct nf_conntrack_man *, char); |
7d8c5018 PM |
67 | } search[IP_CT_DIR_MAX][2] = { |
68 | [IP_CT_DIR_ORIGINAL] = { | |
69 | { | |
70 | .pattern = "PORT", | |
71 | .plen = sizeof("PORT") - 1, | |
72 | .skip = ' ', | |
73 | .term = '\r', | |
55a73324 | 74 | .ftptype = NF_CT_FTP_PORT, |
7d8c5018 PM |
75 | .getnum = try_rfc959, |
76 | }, | |
77 | { | |
78 | .pattern = "EPRT", | |
79 | .plen = sizeof("EPRT") - 1, | |
80 | .skip = ' ', | |
81 | .term = '\r', | |
55a73324 | 82 | .ftptype = NF_CT_FTP_EPRT, |
7d8c5018 PM |
83 | .getnum = try_eprt, |
84 | }, | |
9fb9cbb1 | 85 | }, |
7d8c5018 PM |
86 | [IP_CT_DIR_REPLY] = { |
87 | { | |
88 | .pattern = "227 ", | |
89 | .plen = sizeof("227 ") - 1, | |
90 | .skip = '(', | |
91 | .term = ')', | |
55a73324 | 92 | .ftptype = NF_CT_FTP_PASV, |
7d8c5018 PM |
93 | .getnum = try_rfc959, |
94 | }, | |
95 | { | |
96 | .pattern = "229 ", | |
97 | .plen = sizeof("229 ") - 1, | |
98 | .skip = '(', | |
99 | .term = ')', | |
55a73324 | 100 | .ftptype = NF_CT_FTP_EPSV, |
7d8c5018 PM |
101 | .getnum = try_epsv_response, |
102 | }, | |
9fb9cbb1 YK |
103 | }, |
104 | }; | |
105 | ||
9fb9cbb1 YK |
106 | static int |
107 | get_ipv6_addr(const char *src, size_t dlen, struct in6_addr *dst, u_int8_t term) | |
108 | { | |
6a28ec8c DM |
109 | const char *end; |
110 | int ret = in6_pton(src, min_t(size_t, dlen, 0xffff), (u8 *)dst, term, &end); | |
1884f78c YH |
111 | if (ret > 0) |
112 | return (int)(end - src); | |
113 | return 0; | |
9fb9cbb1 YK |
114 | } |
115 | ||
116 | static int try_number(const char *data, size_t dlen, u_int32_t array[], | |
601e68e1 | 117 | int array_size, char sep, char term) |
9fb9cbb1 YK |
118 | { |
119 | u_int32_t i, len; | |
120 | ||
121 | memset(array, 0, sizeof(array[0])*array_size); | |
122 | ||
123 | /* Keep data pointing at next char. */ | |
124 | for (i = 0, len = 0; len < dlen && i < array_size; len++, data++) { | |
125 | if (*data >= '0' && *data <= '9') { | |
126 | array[i] = array[i]*10 + *data - '0'; | |
127 | } | |
128 | else if (*data == sep) | |
129 | i++; | |
130 | else { | |
131 | /* Unexpected character; true if it's the | |
132 | terminator and we're finished. */ | |
133 | if (*data == term && i == array_size - 1) | |
134 | return len; | |
135 | ||
0d53778e PM |
136 | pr_debug("Char %u (got %u nums) `%u' unexpected\n", |
137 | len, i, *data); | |
9fb9cbb1 YK |
138 | return 0; |
139 | } | |
140 | } | |
0d53778e PM |
141 | pr_debug("Failed to fill %u numbers separated by %c\n", |
142 | array_size, sep); | |
9fb9cbb1 YK |
143 | return 0; |
144 | } | |
145 | ||
146 | /* Returns 0, or length of numbers: 192,168,1,1,5,6 */ | |
147 | static int try_rfc959(const char *data, size_t dlen, | |
148 | struct nf_conntrack_man *cmd, char term) | |
149 | { | |
150 | int length; | |
151 | u_int32_t array[6]; | |
152 | ||
153 | length = try_number(data, dlen, array, 6, ',', term); | |
154 | if (length == 0) | |
155 | return 0; | |
156 | ||
157 | cmd->u3.ip = htonl((array[0] << 24) | (array[1] << 16) | | |
158 | (array[2] << 8) | array[3]); | |
159 | cmd->u.tcp.port = htons((array[4] << 8) | array[5]); | |
160 | return length; | |
161 | } | |
162 | ||
163 | /* Grab port: number up to delimiter */ | |
164 | static int get_port(const char *data, int start, size_t dlen, char delim, | |
bff9a89b | 165 | __be16 *port) |
9fb9cbb1 YK |
166 | { |
167 | u_int16_t tmp_port = 0; | |
168 | int i; | |
169 | ||
170 | for (i = start; i < dlen; i++) { | |
171 | /* Finished? */ | |
172 | if (data[i] == delim) { | |
173 | if (tmp_port == 0) | |
174 | break; | |
175 | *port = htons(tmp_port); | |
0d53778e | 176 | pr_debug("get_port: return %d\n", tmp_port); |
9fb9cbb1 YK |
177 | return i + 1; |
178 | } | |
179 | else if (data[i] >= '0' && data[i] <= '9') | |
180 | tmp_port = tmp_port*10 + data[i] - '0'; | |
181 | else { /* Some other crap */ | |
0d53778e | 182 | pr_debug("get_port: invalid char.\n"); |
9fb9cbb1 YK |
183 | break; |
184 | } | |
185 | } | |
186 | return 0; | |
187 | } | |
188 | ||
189 | /* Returns 0, or length of numbers: |1|132.235.1.2|6275| or |2|3ffe::1|6275| */ | |
190 | static int try_eprt(const char *data, size_t dlen, struct nf_conntrack_man *cmd, | |
191 | char term) | |
192 | { | |
193 | char delim; | |
194 | int length; | |
195 | ||
196 | /* First character is delimiter, then "1" for IPv4 or "2" for IPv6, | |
197 | then delimiter again. */ | |
198 | if (dlen <= 3) { | |
0d53778e | 199 | pr_debug("EPRT: too short\n"); |
9fb9cbb1 YK |
200 | return 0; |
201 | } | |
202 | delim = data[0]; | |
203 | if (isdigit(delim) || delim < 33 || delim > 126 || data[2] != delim) { | |
0d53778e | 204 | pr_debug("try_eprt: invalid delimitter.\n"); |
9fb9cbb1 YK |
205 | return 0; |
206 | } | |
207 | ||
208 | if ((cmd->l3num == PF_INET && data[1] != '1') || | |
209 | (cmd->l3num == PF_INET6 && data[1] != '2')) { | |
0d53778e | 210 | pr_debug("EPRT: invalid protocol number.\n"); |
9fb9cbb1 YK |
211 | return 0; |
212 | } | |
213 | ||
0d53778e | 214 | pr_debug("EPRT: Got %c%c%c\n", delim, data[1], delim); |
9fb9cbb1 YK |
215 | |
216 | if (data[1] == '1') { | |
217 | u_int32_t array[4]; | |
218 | ||
219 | /* Now we have IP address. */ | |
220 | length = try_number(data + 3, dlen - 3, array, 4, '.', delim); | |
221 | if (length != 0) | |
222 | cmd->u3.ip = htonl((array[0] << 24) | (array[1] << 16) | |
223 | | (array[2] << 8) | array[3]); | |
224 | } else { | |
225 | /* Now we have IPv6 address. */ | |
226 | length = get_ipv6_addr(data + 3, dlen - 3, | |
227 | (struct in6_addr *)cmd->u3.ip6, delim); | |
228 | } | |
229 | ||
230 | if (length == 0) | |
231 | return 0; | |
0d53778e | 232 | pr_debug("EPRT: Got IP address!\n"); |
9fb9cbb1 YK |
233 | /* Start offset includes initial "|1|", and trailing delimiter */ |
234 | return get_port(data, 3 + length + 1, dlen, delim, &cmd->u.tcp.port); | |
235 | } | |
236 | ||
237 | /* Returns 0, or length of numbers: |||6446| */ | |
238 | static int try_epsv_response(const char *data, size_t dlen, | |
239 | struct nf_conntrack_man *cmd, char term) | |
240 | { | |
241 | char delim; | |
242 | ||
243 | /* Three delimiters. */ | |
244 | if (dlen <= 3) return 0; | |
245 | delim = data[0]; | |
f64f9e71 JP |
246 | if (isdigit(delim) || delim < 33 || delim > 126 || |
247 | data[1] != delim || data[2] != delim) | |
9fb9cbb1 YK |
248 | return 0; |
249 | ||
250 | return get_port(data, 3, dlen, delim, &cmd->u.tcp.port); | |
251 | } | |
252 | ||
253 | /* Return 1 for match, 0 for accept, -1 for partial. */ | |
254 | static int find_pattern(const char *data, size_t dlen, | |
255 | const char *pattern, size_t plen, | |
256 | char skip, char term, | |
257 | unsigned int *numoff, | |
258 | unsigned int *numlen, | |
259 | struct nf_conntrack_man *cmd, | |
260 | int (*getnum)(const char *, size_t, | |
261 | struct nf_conntrack_man *, char)) | |
262 | { | |
263 | size_t i; | |
264 | ||
0d53778e | 265 | pr_debug("find_pattern `%s': dlen = %Zu\n", pattern, dlen); |
9fb9cbb1 YK |
266 | if (dlen == 0) |
267 | return 0; | |
268 | ||
269 | if (dlen <= plen) { | |
270 | /* Short packet: try for partial? */ | |
271 | if (strnicmp(data, pattern, dlen) == 0) | |
272 | return -1; | |
273 | else return 0; | |
274 | } | |
275 | ||
276 | if (strnicmp(data, pattern, plen) != 0) { | |
277 | #if 0 | |
278 | size_t i; | |
279 | ||
0d53778e | 280 | pr_debug("ftp: string mismatch\n"); |
9fb9cbb1 | 281 | for (i = 0; i < plen; i++) { |
0d53778e PM |
282 | pr_debug("ftp:char %u `%c'(%u) vs `%c'(%u)\n", |
283 | i, data[i], data[i], | |
284 | pattern[i], pattern[i]); | |
9fb9cbb1 YK |
285 | } |
286 | #endif | |
287 | return 0; | |
288 | } | |
289 | ||
0d53778e | 290 | pr_debug("Pattern matches!\n"); |
9fb9cbb1 YK |
291 | /* Now we've found the constant string, try to skip |
292 | to the 'skip' character */ | |
293 | for (i = plen; data[i] != skip; i++) | |
294 | if (i == dlen - 1) return -1; | |
295 | ||
296 | /* Skip over the last character */ | |
297 | i++; | |
298 | ||
0d53778e | 299 | pr_debug("Skipped up to `%c'!\n", skip); |
9fb9cbb1 YK |
300 | |
301 | *numoff = i; | |
302 | *numlen = getnum(data + i, dlen - i, cmd, term); | |
303 | if (!*numlen) | |
304 | return -1; | |
305 | ||
0d53778e | 306 | pr_debug("Match succeeded!\n"); |
9fb9cbb1 YK |
307 | return 1; |
308 | } | |
309 | ||
310 | /* Look up to see if we're just after a \n. */ | |
55a73324 | 311 | static int find_nl_seq(u32 seq, const struct nf_ct_ftp_master *info, int dir) |
9fb9cbb1 YK |
312 | { |
313 | unsigned int i; | |
314 | ||
315 | for (i = 0; i < info->seq_aft_nl_num[dir]; i++) | |
316 | if (info->seq_aft_nl[dir][i] == seq) | |
317 | return 1; | |
318 | return 0; | |
319 | } | |
320 | ||
321 | /* We don't update if it's older than what we have. */ | |
a71996fc AD |
322 | static void update_nl_seq(struct nf_conn *ct, u32 nl_seq, |
323 | struct nf_ct_ftp_master *info, int dir, | |
9fb9cbb1 YK |
324 | struct sk_buff *skb) |
325 | { | |
326 | unsigned int i, oldest = NUM_SEQ_TO_REMEMBER; | |
327 | ||
328 | /* Look for oldest: if we find exact match, we're done. */ | |
329 | for (i = 0; i < info->seq_aft_nl_num[dir]; i++) { | |
330 | if (info->seq_aft_nl[dir][i] == nl_seq) | |
331 | return; | |
332 | ||
5fe26f53 PM |
333 | if (oldest == info->seq_aft_nl_num[dir] || |
334 | before(info->seq_aft_nl[dir][i], | |
335 | info->seq_aft_nl[dir][oldest])) | |
9fb9cbb1 YK |
336 | oldest = i; |
337 | } | |
338 | ||
339 | if (info->seq_aft_nl_num[dir] < NUM_SEQ_TO_REMEMBER) { | |
340 | info->seq_aft_nl[dir][info->seq_aft_nl_num[dir]++] = nl_seq; | |
5fe26f53 PM |
341 | } else if (oldest != NUM_SEQ_TO_REMEMBER && |
342 | after(nl_seq, info->seq_aft_nl[dir][oldest])) { | |
9fb9cbb1 | 343 | info->seq_aft_nl[dir][oldest] = nl_seq; |
9fb9cbb1 YK |
344 | } |
345 | } | |
346 | ||
3db05fea | 347 | static int help(struct sk_buff *skb, |
9fb9cbb1 YK |
348 | unsigned int protoff, |
349 | struct nf_conn *ct, | |
350 | enum ip_conntrack_info ctinfo) | |
351 | { | |
352 | unsigned int dataoff, datalen; | |
58c0fb0d JE |
353 | const struct tcphdr *th; |
354 | struct tcphdr _tcph; | |
355 | const char *fb_ptr; | |
9fb9cbb1 YK |
356 | int ret; |
357 | u32 seq; | |
358 | int dir = CTINFO2DIR(ctinfo); | |
d6e8cc6c | 359 | unsigned int uninitialized_var(matchlen), uninitialized_var(matchoff); |
55a73324 | 360 | struct nf_ct_ftp_master *ct_ftp_info = &nfct_help(ct)->help.ct_ftp_info; |
9fb9cbb1 | 361 | struct nf_conntrack_expect *exp; |
643a2c15 | 362 | union nf_inet_addr *daddr; |
9fb9cbb1 | 363 | struct nf_conntrack_man cmd = {}; |
9fb9cbb1 YK |
364 | unsigned int i; |
365 | int found = 0, ends_in_nl; | |
337fbc41 | 366 | typeof(nf_nat_ftp_hook) nf_nat_ftp; |
9fb9cbb1 YK |
367 | |
368 | /* Until there's been traffic both ways, don't look in packets. */ | |
f64f9e71 JP |
369 | if (ctinfo != IP_CT_ESTABLISHED && |
370 | ctinfo != IP_CT_ESTABLISHED + IP_CT_IS_REPLY) { | |
0d53778e | 371 | pr_debug("ftp: Conntrackinfo = %u\n", ctinfo); |
9fb9cbb1 YK |
372 | return NF_ACCEPT; |
373 | } | |
374 | ||
3db05fea | 375 | th = skb_header_pointer(skb, protoff, sizeof(_tcph), &_tcph); |
9fb9cbb1 YK |
376 | if (th == NULL) |
377 | return NF_ACCEPT; | |
378 | ||
379 | dataoff = protoff + th->doff * 4; | |
380 | /* No data? */ | |
3db05fea | 381 | if (dataoff >= skb->len) { |
0d53778e | 382 | pr_debug("ftp: dataoff(%u) >= skblen(%u)\n", dataoff, |
3db05fea | 383 | skb->len); |
9fb9cbb1 YK |
384 | return NF_ACCEPT; |
385 | } | |
3db05fea | 386 | datalen = skb->len - dataoff; |
9fb9cbb1 YK |
387 | |
388 | spin_lock_bh(&nf_ftp_lock); | |
3db05fea | 389 | fb_ptr = skb_header_pointer(skb, dataoff, datalen, ftp_buffer); |
9fb9cbb1 YK |
390 | BUG_ON(fb_ptr == NULL); |
391 | ||
392 | ends_in_nl = (fb_ptr[datalen - 1] == '\n'); | |
393 | seq = ntohl(th->seq) + datalen; | |
394 | ||
395 | /* Look up to see if we're just after a \n. */ | |
396 | if (!find_nl_seq(ntohl(th->seq), ct_ftp_info, dir)) { | |
397 | /* Now if this ends in \n, update ftp info. */ | |
0d53778e PM |
398 | pr_debug("nf_conntrack_ftp: wrong seq pos %s(%u) or %s(%u)\n", |
399 | ct_ftp_info->seq_aft_nl_num[dir] > 0 ? "" : "(UNSET)", | |
400 | ct_ftp_info->seq_aft_nl[dir][0], | |
401 | ct_ftp_info->seq_aft_nl_num[dir] > 1 ? "" : "(UNSET)", | |
402 | ct_ftp_info->seq_aft_nl[dir][1]); | |
9fb9cbb1 YK |
403 | ret = NF_ACCEPT; |
404 | goto out_update_nl; | |
405 | } | |
406 | ||
601e68e1 YH |
407 | /* Initialize IP/IPv6 addr to expected address (it's not mentioned |
408 | in EPSV responses) */ | |
5e8fbe2a | 409 | cmd.l3num = nf_ct_l3num(ct); |
9fb9cbb1 YK |
410 | memcpy(cmd.u3.all, &ct->tuplehash[dir].tuple.src.u3.all, |
411 | sizeof(cmd.u3.all)); | |
412 | ||
7d8c5018 | 413 | for (i = 0; i < ARRAY_SIZE(search[dir]); i++) { |
9fb9cbb1 | 414 | found = find_pattern(fb_ptr, datalen, |
7d8c5018 PM |
415 | search[dir][i].pattern, |
416 | search[dir][i].plen, | |
417 | search[dir][i].skip, | |
418 | search[dir][i].term, | |
9fb9cbb1 YK |
419 | &matchoff, &matchlen, |
420 | &cmd, | |
7d8c5018 | 421 | search[dir][i].getnum); |
9fb9cbb1 YK |
422 | if (found) break; |
423 | } | |
424 | if (found == -1) { | |
425 | /* We don't usually drop packets. After all, this is | |
426 | connection tracking, not packet filtering. | |
427 | However, it is necessary for accurate tracking in | |
428 | this case. */ | |
4813eadf PM |
429 | pr_debug("conntrack_ftp: partial %s %u+%u\n", |
430 | search[dir][i].pattern, ntohl(th->seq), datalen); | |
9fb9cbb1 YK |
431 | ret = NF_DROP; |
432 | goto out; | |
433 | } else if (found == 0) { /* No match */ | |
434 | ret = NF_ACCEPT; | |
435 | goto out_update_nl; | |
436 | } | |
437 | ||
0d53778e PM |
438 | pr_debug("conntrack_ftp: match `%.*s' (%u bytes at %u)\n", |
439 | matchlen, fb_ptr + matchoff, | |
440 | matchlen, ntohl(th->seq) + matchoff); | |
9fb9cbb1 | 441 | |
6823645d | 442 | exp = nf_ct_expect_alloc(ct); |
9fb9cbb1 YK |
443 | if (exp == NULL) { |
444 | ret = NF_DROP; | |
445 | goto out; | |
446 | } | |
447 | ||
448 | /* We refer to the reverse direction ("!dir") tuples here, | |
449 | * because we're expecting something in the other direction. | |
450 | * Doesn't matter unless NAT is happening. */ | |
df43b4e7 | 451 | daddr = &ct->tuplehash[!dir].tuple.dst.u3; |
9fb9cbb1 YK |
452 | |
453 | /* Update the ftp info */ | |
5e8fbe2a | 454 | if ((cmd.l3num == nf_ct_l3num(ct)) && |
9fb9cbb1 YK |
455 | memcmp(&cmd.u3.all, &ct->tuplehash[dir].tuple.src.u3.all, |
456 | sizeof(cmd.u3.all))) { | |
457 | /* Enrico Scholz's passive FTP to partially RNAT'd ftp | |
601e68e1 YH |
458 | server: it really wants us to connect to a |
459 | different IP address. Simply don't record it for | |
460 | NAT. */ | |
9fb9cbb1 | 461 | if (cmd.l3num == PF_INET) { |
14d5e834 HH |
462 | pr_debug("conntrack_ftp: NOT RECORDING: %pI4 != %pI4\n", |
463 | &cmd.u3.ip, | |
464 | &ct->tuplehash[dir].tuple.src.u3.ip); | |
9fb9cbb1 | 465 | } else { |
5b095d98 | 466 | pr_debug("conntrack_ftp: NOT RECORDING: %pI6 != %pI6\n", |
38ff4fa4 HH |
467 | cmd.u3.ip6, |
468 | ct->tuplehash[dir].tuple.src.u3.ip6); | |
9fb9cbb1 YK |
469 | } |
470 | ||
471 | /* Thanks to Cristiano Lincoln Mattos | |
472 | <lincoln@cesar.org.br> for reporting this potential | |
473 | problem (DMZ machines opening holes to internal | |
474 | networks, or the packet filter itself). */ | |
475 | if (!loose) { | |
476 | ret = NF_ACCEPT; | |
477 | goto out_put_expect; | |
478 | } | |
df43b4e7 | 479 | daddr = &cmd.u3; |
9fb9cbb1 YK |
480 | } |
481 | ||
6002f266 | 482 | nf_ct_expect_init(exp, NF_CT_EXPECT_CLASS_DEFAULT, cmd.l3num, |
df43b4e7 PM |
483 | &ct->tuplehash[!dir].tuple.src.u3, daddr, |
484 | IPPROTO_TCP, NULL, &cmd.u.tcp.port); | |
9fb9cbb1 YK |
485 | |
486 | /* Now, NAT might want to mangle the packet, and register the | |
487 | * (possibly changed) expectation itself. */ | |
337fbc41 | 488 | nf_nat_ftp = rcu_dereference(nf_nat_ftp_hook); |
55a73324 | 489 | if (nf_nat_ftp && ct->status & IPS_NAT_MASK) |
3db05fea | 490 | ret = nf_nat_ftp(skb, ctinfo, search[dir][i].ftptype, |
25b86e05 | 491 | matchoff, matchlen, exp); |
9fb9cbb1 YK |
492 | else { |
493 | /* Can't expect this? Best to drop packet now. */ | |
6823645d | 494 | if (nf_ct_expect_related(exp) != 0) |
9fb9cbb1 YK |
495 | ret = NF_DROP; |
496 | else | |
497 | ret = NF_ACCEPT; | |
498 | } | |
499 | ||
500 | out_put_expect: | |
6823645d | 501 | nf_ct_expect_put(exp); |
9fb9cbb1 YK |
502 | |
503 | out_update_nl: | |
504 | /* Now if this ends in \n, update ftp info. Seq may have been | |
505 | * adjusted by NAT code. */ | |
506 | if (ends_in_nl) | |
a71996fc | 507 | update_nl_seq(ct, seq, ct_ftp_info, dir, skb); |
9fb9cbb1 YK |
508 | out: |
509 | spin_unlock_bh(&nf_ftp_lock); | |
510 | return ret; | |
511 | } | |
512 | ||
ec59a111 PM |
513 | static struct nf_conntrack_helper ftp[MAX_PORTS][2] __read_mostly; |
514 | static char ftp_names[MAX_PORTS][2][sizeof("ftp-65535")] __read_mostly; | |
9fb9cbb1 | 515 | |
6002f266 PM |
516 | static const struct nf_conntrack_expect_policy ftp_exp_policy = { |
517 | .max_expected = 1, | |
518 | .timeout = 5 * 60, | |
519 | }; | |
520 | ||
9fb9cbb1 | 521 | /* don't make this __exit, since it's called from __init ! */ |
65b4b4e8 | 522 | static void nf_conntrack_ftp_fini(void) |
9fb9cbb1 YK |
523 | { |
524 | int i, j; | |
525 | for (i = 0; i < ports_c; i++) { | |
526 | for (j = 0; j < 2; j++) { | |
527 | if (ftp[i][j].me == NULL) | |
528 | continue; | |
529 | ||
0d53778e PM |
530 | pr_debug("nf_ct_ftp: unregistering helper for pf: %d " |
531 | "port: %d\n", | |
532 | ftp[i][j].tuple.src.l3num, ports[i]); | |
9fb9cbb1 YK |
533 | nf_conntrack_helper_unregister(&ftp[i][j]); |
534 | } | |
535 | } | |
536 | ||
537 | kfree(ftp_buffer); | |
538 | } | |
539 | ||
65b4b4e8 | 540 | static int __init nf_conntrack_ftp_init(void) |
9fb9cbb1 YK |
541 | { |
542 | int i, j = -1, ret = 0; | |
543 | char *tmpname; | |
544 | ||
545 | ftp_buffer = kmalloc(65536, GFP_KERNEL); | |
546 | if (!ftp_buffer) | |
547 | return -ENOMEM; | |
548 | ||
549 | if (ports_c == 0) | |
550 | ports[ports_c++] = FTP_PORT; | |
551 | ||
552 | /* FIXME should be configurable whether IPv4 and IPv6 FTP connections | |
553 | are tracked or not - YK */ | |
554 | for (i = 0; i < ports_c; i++) { | |
9fb9cbb1 YK |
555 | ftp[i][0].tuple.src.l3num = PF_INET; |
556 | ftp[i][1].tuple.src.l3num = PF_INET6; | |
557 | for (j = 0; j < 2; j++) { | |
558 | ftp[i][j].tuple.src.u.tcp.port = htons(ports[i]); | |
559 | ftp[i][j].tuple.dst.protonum = IPPROTO_TCP; | |
6002f266 | 560 | ftp[i][j].expect_policy = &ftp_exp_policy; |
9fb9cbb1 YK |
561 | ftp[i][j].me = THIS_MODULE; |
562 | ftp[i][j].help = help; | |
563 | tmpname = &ftp_names[i][j][0]; | |
564 | if (ports[i] == FTP_PORT) | |
565 | sprintf(tmpname, "ftp"); | |
566 | else | |
567 | sprintf(tmpname, "ftp-%d", ports[i]); | |
568 | ftp[i][j].name = tmpname; | |
569 | ||
0d53778e PM |
570 | pr_debug("nf_ct_ftp: registering helper for pf: %d " |
571 | "port: %d\n", | |
572 | ftp[i][j].tuple.src.l3num, ports[i]); | |
9fb9cbb1 YK |
573 | ret = nf_conntrack_helper_register(&ftp[i][j]); |
574 | if (ret) { | |
575 | printk("nf_ct_ftp: failed to register helper " | |
576 | " for pf: %d port: %d\n", | |
577 | ftp[i][j].tuple.src.l3num, ports[i]); | |
65b4b4e8 | 578 | nf_conntrack_ftp_fini(); |
9fb9cbb1 YK |
579 | return ret; |
580 | } | |
581 | } | |
582 | } | |
583 | ||
584 | return 0; | |
585 | } | |
586 | ||
65b4b4e8 AM |
587 | module_init(nf_conntrack_ftp_init); |
588 | module_exit(nf_conntrack_ftp_fini); |