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a2d9c494 EK |
1 | /* |
2 | * ircd-ratbox: A slightly useful ircd. | |
3 | * filter.c: Drop messages we don't like | |
4 | * | |
5 | * Copyright (C) 1990 Jarkko Oikarinen and University of Oulu, Co Center | |
6 | * Copyright (C) 1996-2002 Hybrid Development Team | |
7 | * Copyright (C) 2002-2005 ircd-ratbox development team | |
8 | * | |
9 | * This program is free software; you can redistribute it and/or modify | |
10 | * it under the terms of the GNU General Public License as published by | |
11 | * the Free Software Foundation; either version 2 of the License, or | |
12 | * (at your option) any later version. | |
13 | * | |
14 | * This program is distributed in the hope that it will be useful, | |
15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | * GNU General Public License for more details. | |
18 | * | |
19 | * You should have received a copy of the GNU General Public License | |
20 | * along with this program; if not, write to the Free Software | |
21 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 | |
22 | * USA | |
23 | * | |
24 | * $Id$ | |
25 | */ | |
26 | ||
27 | #include "stdinc.h" | |
28 | #include "channel.h" | |
29 | #include "client.h" | |
30 | #include "match.h" | |
31 | #include "ircd.h" | |
32 | #include "numeric.h" | |
33 | #include "send.h" | |
34 | #include "s_serv.h" | |
35 | #include "s_newconf.h" | |
36 | #include "msg.h" | |
37 | #include "parse.h" | |
38 | #include "modules.h" | |
39 | #include "operhash.h" | |
40 | #include "inline/stringops.h" | |
41 | #include "msgbuf.h" | |
42 | ||
43 | #include <hs_common.h> | |
44 | #include <hs_runtime.h> | |
45 | ||
81e41406 EK |
46 | #define FILTER_NICK 0 |
47 | #define FILTER_USER 0 | |
48 | #define FILTER_HOST 0 | |
49 | ||
a2d9c494 EK |
50 | static void filter_msg_user(void *data); |
51 | static void filter_msg_channel(void *data); | |
52 | static void on_client_exit(void *data); | |
53 | ||
54 | static void mo_setfilter(struct MsgBuf *, struct Client *, struct Client *, int, const char **); | |
55 | static void me_setfilter(struct MsgBuf *, struct Client *, struct Client *, int, const char **); | |
56 | ||
57 | static char *filter_data = NULL; | |
58 | static size_t filter_data_len = 0; | |
59 | static hs_database_t *filter_db; | |
60 | static hs_scratch_t *filter_scratch; | |
61 | ||
62 | static int filter_enable = 1; | |
63 | ||
64 | static const char *cmdname[MESSAGE_TYPE_COUNT] = { | |
65 | [MESSAGE_TYPE_PRIVMSG] = "PRIVMSG", | |
66 | [MESSAGE_TYPE_NOTICE] = "NOTICE", | |
67 | }; | |
68 | ||
69 | enum filter_state { | |
70 | FILTER_EMPTY, | |
71 | FILTER_FILLING, | |
72 | FILTER_LOADED | |
73 | }; | |
74 | ||
75 | #define ACT_DROP (1 << 0) | |
76 | #define ACT_KILL (1 << 1) | |
77 | #define ACT_ALARM (1 << 2) | |
78 | ||
79 | static enum filter_state state = FILTER_EMPTY; | |
80 | static char check_str[21] = ""; | |
81 | ||
82 | mapi_hfn_list_av1 filter_hfnlist[] = { | |
83 | { "privmsg_user", (hookfn) filter_msg_user }, | |
84 | { "privmsg_channel", (hookfn) filter_msg_channel }, | |
85 | { "client_exit", (hookfn) on_client_exit }, | |
86 | { NULL, NULL } | |
87 | }; | |
88 | ||
89 | ||
90 | struct Message setfilter_msgtab = { | |
91 | "SETFILTER", 0, 0, 0, 0, | |
92 | {mg_unreg, mg_not_oper, mg_ignore, mg_ignore, {me_setfilter, 2}, {mo_setfilter, 2}} | |
93 | }; | |
94 | ||
95 | static void | |
96 | moddeinit(void) | |
97 | { | |
98 | if (filter_scratch) | |
99 | hs_free_scratch(filter_scratch); | |
100 | if (filter_db) | |
101 | hs_free_database(filter_db); | |
102 | if (filter_data) | |
103 | rb_free(filter_data); | |
104 | } | |
105 | ||
106 | ||
107 | mapi_clist_av1 filter_clist[] = { &setfilter_msgtab, NULL }; | |
108 | ||
4950a943 | 109 | DECLARE_MODULE_AV1(filter, NULL, moddeinit, filter_clist, NULL, filter_hfnlist, "0.3"); |
a2d9c494 EK |
110 | |
111 | static int | |
112 | setfilter(const char *check, const char *data, const char **error) | |
113 | { | |
114 | if (error) *error = "unknown"; | |
115 | ||
116 | if (!strcasecmp(data, "disable")) { | |
117 | filter_enable = 0; | |
118 | sendto_realops_snomask(SNO_GENERAL, L_ALL | L_NETWIDE, | |
119 | "Filtering disabled."); | |
120 | return 0; | |
121 | } | |
122 | if (!strcasecmp(data, "enable")) { | |
123 | filter_enable = 1; | |
124 | sendto_realops_snomask(SNO_GENERAL, L_ALL | L_NETWIDE, | |
125 | "Filtering enabled."); | |
126 | return 0; | |
127 | } | |
128 | ||
129 | if (strlen(check) > sizeof check_str - 1) { | |
130 | if (error) *error = "check string too long"; | |
131 | return -1; | |
132 | } | |
133 | ||
134 | if (!strcasecmp(data, "new")) { | |
135 | if (state == FILTER_FILLING) { | |
136 | rb_free(filter_data); | |
137 | filter_data = 0; | |
138 | filter_data_len = 0; | |
139 | } | |
140 | state = FILTER_FILLING; | |
141 | strcpy(check_str, check); | |
142 | return 0; | |
143 | } | |
144 | ||
145 | if (strcmp(check, check_str) != 0) { | |
146 | if (error) *error = "check strings don't match"; | |
147 | return -1; | |
148 | } | |
149 | ||
150 | if (!strcasecmp(data, "apply")) { | |
151 | if (state != FILTER_FILLING) { | |
152 | if (error) *error = "not loading anything"; | |
153 | return -1; | |
154 | } | |
155 | hs_database_t *db; | |
156 | hs_error_t r = hs_deserialize_database(filter_data, filter_data_len, &db); | |
157 | if (r != HS_SUCCESS) { | |
158 | if (error) *error = "couldn't deserialize db"; | |
159 | return -1; | |
160 | } | |
161 | r = hs_alloc_scratch(db, &filter_scratch); | |
162 | if (r != HS_SUCCESS) { | |
163 | if (error) *error = "couldn't allocate scratch"; | |
164 | return -1; | |
165 | } | |
166 | if (filter_db) { | |
167 | hs_free_database(filter_db); | |
168 | } | |
169 | state = FILTER_LOADED; | |
170 | filter_db = db; | |
171 | sendto_realops_snomask(SNO_GENERAL, L_ALL | L_NETWIDE, | |
172 | "New filters loaded."); | |
173 | rb_free(filter_data); | |
174 | filter_data = 0; | |
175 | filter_data_len = 0; | |
176 | return 0; | |
177 | } | |
178 | ||
179 | if (state == FILTER_FILLING) { | |
180 | int dl; | |
181 | unsigned char *d = rb_base64_decode(data, strlen(data), &dl); | |
182 | if (!d) { | |
183 | if (error) *error = "invalid data"; | |
184 | return -1; | |
185 | } | |
186 | if (filter_data_len + dl > 10000000ul) { | |
187 | if (error) *error = "data over size limit"; | |
188 | rb_free(d); | |
189 | return -1; | |
190 | } | |
191 | filter_data = rb_realloc(filter_data, filter_data_len + dl); | |
192 | memcpy(filter_data + filter_data_len, d, dl); | |
193 | rb_free(d); | |
194 | filter_data_len += dl; | |
195 | } else { | |
196 | if (error) *error = "send \"new\" first"; | |
197 | return -1; | |
198 | } | |
199 | return 0; | |
200 | } | |
201 | ||
202 | /* /SETFILTER [server-mask] <check> { NEW | APPLY | <data> } | |
203 | * <check> must be the same for the entirety of a new...data...apply run, | |
204 | * and exists just to ensure runs don't mix | |
205 | * NEW prepares a buffer to receive a hyperscan database | |
206 | * <data> is base64 encoded chunks of hyperscan database, which are decoded | |
207 | * and appended to the buffer | |
208 | * APPLY deserialises the buffer and sets the resulting hyperscan database | |
209 | * as the one to use for filtering */ | |
210 | static void | |
211 | mo_setfilter(struct MsgBuf *msgbuf, struct Client *client_p, struct Client *source_p, int parc, const char **parv) | |
212 | { | |
213 | int for_me = 0; | |
214 | const char *check; | |
215 | const char *data; | |
216 | if (!IsOperAdmin(source_p)) { | |
217 | sendto_one(source_p, form_str(ERR_NOPRIVS), me.name, source_p->name, "admin"); | |
218 | return; | |
219 | } | |
220 | if (parc == 4) { | |
221 | check = parv[2]; | |
222 | data = parv[3]; | |
223 | if(match(parv[1], me.name)) { | |
224 | for_me = 1; | |
225 | } | |
226 | sendto_match_servs(source_p, parv[1], | |
227 | CAP_ENCAP, NOCAPS, | |
228 | "ENCAP %s SETFILTER %s :%s", parv[1], check, data); | |
229 | } else if (parc == 3) { | |
230 | check = parv[1]; | |
231 | data = parv[2]; | |
232 | for_me = 1; | |
233 | } else { | |
234 | sendto_one_notice(source_p, ":SETFILTER needs 2 or 3 params, have %d", parc - 1); | |
235 | return; | |
236 | } | |
237 | if (for_me) { | |
238 | const char *error; | |
239 | int r = setfilter(check, data, &error); | |
240 | if (r) { | |
241 | sendto_one_notice(source_p, ":SETFILTER failed: %s", error); | |
242 | } else { | |
243 | sendto_one_notice(source_p, ":SETFILTER ok"); | |
244 | } | |
245 | } | |
246 | } | |
247 | ||
248 | static void | |
249 | me_setfilter(struct MsgBuf *msgbuf, struct Client *client_p, struct Client *source_p, int parc, const char **parv) | |
250 | { | |
251 | if(!IsPerson(source_p)) | |
252 | return; | |
253 | ||
254 | const char *error; | |
255 | int r = setfilter(parv[1], parv[2], &error); | |
256 | if (r) { | |
257 | sendto_one_notice(source_p, ":SETFILTER failed: %s", error); | |
258 | } | |
259 | ||
260 | return; | |
261 | } | |
262 | ||
263 | /* will be called for every match | |
264 | * hyperscan provides us one piece of information about the expression | |
265 | * matched, an integer ID. we're co-opting the lowest 3 bits of this | |
266 | * as a flag set. conveniently, this means all we really need to do | |
267 | * here is or the IDs together. */ | |
268 | int match_callback(unsigned id, | |
269 | unsigned long long from, | |
270 | unsigned long long to, | |
271 | unsigned flags, | |
272 | void *context_) | |
273 | { | |
274 | unsigned *context = context_; | |
275 | *context |= id; | |
276 | return 0; | |
277 | } | |
278 | ||
279 | ||
280 | unsigned match_message(const char *msg) | |
281 | { | |
282 | unsigned state = 0; | |
283 | if (!filter_enable) | |
284 | return 0; | |
285 | if (!filter_db) | |
286 | return 0; | |
287 | hs_error_t r = hs_scan(filter_db, msg, strlen(msg), 0, filter_scratch, match_callback, &state); | |
288 | if (r != HS_SUCCESS && r != HS_SCAN_TERMINATED) | |
289 | return 0; | |
290 | return state; | |
291 | } | |
292 | ||
293 | static char check_buffer[2000]; | |
f982238e | 294 | static char clean_buffer[BUFSIZE]; |
a2d9c494 EK |
295 | |
296 | void | |
297 | filter_msg_user(void *data_) | |
298 | { | |
299 | hook_data_privmsg_user *data = data_; | |
300 | struct Client *s = data->source_p; | |
86ee00db EK |
301 | /* we only need to filter once */ |
302 | if (!MyClient(s)) { | |
303 | return; | |
304 | } | |
a2d9c494 EK |
305 | /* opers are immune to checking, for obvious reasons |
306 | * anything sent to an oper is also immune, because that should make it | |
307 | * less impossible to deal with reports. */ | |
308 | if (IsOper(s) || IsOper(data->target_p)) { | |
309 | return; | |
310 | } | |
f982238e | 311 | char *text = strcpy(clean_buffer, data->text); |
a2d9c494 EK |
312 | strip_colour(text); |
313 | strip_unprintable(text); | |
11c11f30 | 314 | snprintf(check_buffer, sizeof check_buffer, ":%s!%s@%s#%c %s 0 :%s", |
81e41406 EK |
315 | #if FILTER_NICK |
316 | s->name, | |
317 | #else | |
318 | "*", | |
319 | #endif | |
320 | #if FILTER_USER | |
321 | s->username, | |
322 | #else | |
323 | "*", | |
324 | #endif | |
325 | #if FILTER_HOST | |
326 | s->host, | |
327 | #else | |
328 | "*", | |
329 | #endif | |
3fbb1d7a | 330 | s->user && s->user->suser[0] != '\0' ? '1' : '0', |
a2d9c494 | 331 | cmdname[data->msgtype], |
a2d9c494 EK |
332 | text); |
333 | unsigned r = match_message(check_buffer); | |
7bb7f899 EK |
334 | if (r & ACT_DROP) { |
335 | sendto_one_numeric(s, ERR_CANNOTSENDTOCHAN, | |
336 | form_str(ERR_CANNOTSENDTOCHAN), | |
337 | data->target_p->name); | |
a2d9c494 EK |
338 | data->approved = 1; |
339 | } | |
86ee00db | 340 | if (r & ACT_ALARM) { |
6a14bf78 | 341 | sendto_realops_snomask(SNO_GENERAL, L_ALL | L_NETWIDE, |
a2d9c494 EK |
342 | "FILTER: %s!%s@%s [%s]", |
343 | s->name, s->username, s->host, s->sockhost); | |
344 | } | |
6a14bf78 | 345 | if (r & ACT_KILL) { |
7bb7f899 | 346 | data->approved = 1; |
6a14bf78 EK |
347 | exit_client(NULL, s, s, "Excess flood"); |
348 | } | |
a2d9c494 EK |
349 | } |
350 | ||
351 | void | |
352 | filter_msg_channel(void *data_) | |
353 | { | |
354 | hook_data_privmsg_channel *data = data_; | |
355 | struct Client *s = data->source_p; | |
86ee00db EK |
356 | /* we only need to filter once */ |
357 | if (!MyClient(s)) { | |
358 | return; | |
359 | } | |
a2d9c494 EK |
360 | /* just normal oper immunity for channels. i'd like to have a mode that |
361 | * disables the filter per-channel, but that's for the future */ | |
362 | if (IsOper(s)) { | |
363 | return; | |
364 | } | |
f982238e | 365 | char *text = strcpy(clean_buffer, data->text); |
a2d9c494 EK |
366 | strip_colour(text); |
367 | strip_unprintable(text); | |
3fbb1d7a | 368 | snprintf(check_buffer, sizeof check_buffer, ":%s!%s@%s#%c %s %s :%s", |
81e41406 EK |
369 | #if FILTER_NICK |
370 | s->name, | |
371 | #else | |
372 | "*", | |
373 | #endif | |
374 | #if FILTER_USER | |
375 | s->username, | |
376 | #else | |
377 | "*", | |
378 | #endif | |
379 | #if FILTER_HOST | |
380 | s->host, | |
381 | #else | |
382 | "*", | |
383 | #endif | |
3fbb1d7a | 384 | s->user && s->user->suser[0] != '\0' ? '1' : '0', |
a2d9c494 EK |
385 | cmdname[data->msgtype], |
386 | data->chptr->chname, | |
387 | text); | |
388 | unsigned r = match_message(check_buffer); | |
7bb7f899 EK |
389 | if (r & ACT_DROP) { |
390 | sendto_one_numeric(s, ERR_CANNOTSENDTOCHAN, | |
391 | form_str(ERR_CANNOTSENDTOCHAN), | |
392 | data->chptr->chname); | |
a2d9c494 EK |
393 | data->approved = 1; |
394 | } | |
86ee00db | 395 | if (r & ACT_ALARM) { |
6a14bf78 | 396 | sendto_realops_snomask(SNO_GENERAL, L_ALL | L_NETWIDE, |
a2d9c494 EK |
397 | "FILTER: %s!%s@%s [%s]", |
398 | s->name, s->username, s->host, s->sockhost); | |
399 | } | |
6a14bf78 | 400 | if (r & ACT_KILL) { |
7bb7f899 | 401 | data->approved = 1; |
6a14bf78 EK |
402 | exit_client(NULL, s, s, "Excess flood"); |
403 | } | |
a2d9c494 EK |
404 | } |
405 | ||
406 | void | |
407 | on_client_exit(void *data_) | |
408 | { | |
409 | /* If we see a netsplit, abort the current FILTER_FILLING attempt */ | |
410 | hook_data_client_exit *data = data_; | |
411 | ||
412 | if (!IsServer(data->target)) return; | |
413 | ||
414 | if (state == FILTER_FILLING) { | |
415 | state = filter_db ? FILTER_LOADED : FILTER_EMPTY; | |
416 | } | |
417 | } | |
418 |