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Commit | Line | Data |
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212380e3 AC |
1 | /* |
2 | * charybdis: A slightly useful ircd. | |
3 | * blacklist.c: Manages DNS blacklist entries and lookups | |
4 | * | |
0a1e77c2 | 5 | * Copyright (C) 2006-2011 charybdis development team |
212380e3 AC |
6 | * |
7 | * Redistribution and use in source and binary forms, with or without | |
8 | * modification, are permitted provided that the following conditions are | |
9 | * met: | |
10 | * | |
11 | * 1. Redistributions of source code must retain the above copyright notice, | |
12 | * this list of conditions and the following disclaimer. | |
13 | * | |
14 | * 2. Redistributions in binary form must reproduce the above copyright | |
15 | * notice, this list of conditions and the following disclaimer in the | |
16 | * documentation and/or other materials provided with the distribution. | |
17 | * | |
18 | * 3. The name of the author may not be used to endorse or promote products | |
19 | * derived from this software without specific prior written permission. | |
20 | * | |
21 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
22 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED | |
23 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | |
24 | * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, | |
25 | * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES | |
26 | * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR | |
27 | * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, | |
29 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING | |
30 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | |
31 | * POSSIBILITY OF SUCH DAMAGE. | |
32 | * | |
212380e3 AC |
33 | */ |
34 | ||
35 | #include "stdinc.h" | |
36 | #include "client.h" | |
37 | #include "res.h" | |
212380e3 AC |
38 | #include "numeric.h" |
39 | #include "reject.h" | |
40 | #include "s_conf.h" | |
41 | #include "s_user.h" | |
42 | #include "blacklist.h" | |
43 | ||
b2f0da88 | 44 | rb_dlink_list blacklist_list = { NULL, NULL, 0 }; |
212380e3 AC |
45 | |
46 | /* private interfaces */ | |
47 | static struct Blacklist *find_blacklist(char *name) | |
48 | { | |
b2f0da88 | 49 | rb_dlink_node *nptr; |
212380e3 | 50 | |
b2f0da88 | 51 | RB_DLINK_FOREACH(nptr, blacklist_list.head) |
212380e3 AC |
52 | { |
53 | struct Blacklist *blptr = (struct Blacklist *) nptr->data; | |
54 | ||
55 | if (!irccmp(blptr->host, name)) | |
56 | return blptr; | |
57 | } | |
58 | ||
59 | return NULL; | |
60 | } | |
61 | ||
3c93d380 EM |
62 | static inline int blacklist_check_reply(struct BlacklistClient *blcptr, struct rb_sockaddr_storage *addr) |
63 | { | |
64 | struct Blacklist *blptr = blcptr->blacklist; | |
65 | char ipaddr[HOSTIPLEN]; | |
66 | char *lastoctet; | |
67 | rb_dlink_node *ptr; | |
68 | ||
69 | /* XXX the below two checks might want to change at some point | |
70 | * e.g. if IPv6 blacklists don't use 127.x.y.z or A records anymore | |
71 | * --Elizabeth | |
72 | */ | |
73 | if (addr->ss_family != AF_INET || | |
74 | memcmp(&((struct sockaddr_in *)addr)->sin_addr, "\177", 1)) | |
75 | goto blwarn; | |
76 | ||
77 | /* No filters and entry found - thus positive match */ | |
78 | if (!rb_dlink_list_length(&blptr->filters)) | |
79 | return 1; | |
80 | ||
81 | rb_inet_ntop_sock((struct sockaddr *)addr, ipaddr, sizeof(ipaddr)); | |
82 | ||
83 | /* Below will prolly have to change too if the above changes */ | |
84 | if ((lastoctet = strrchr(ipaddr, '.')) == NULL || *(++lastoctet) == '\0') | |
85 | goto blwarn; | |
86 | ||
87 | RB_DLINK_FOREACH(ptr, blcptr->blacklist->filters.head) | |
88 | { | |
89 | struct BlacklistFilter *filter = ptr->data; | |
90 | char *cmpstr; | |
91 | ||
92 | if (filter->type == BLACKLIST_FILTER_ALL) | |
93 | cmpstr = ipaddr; | |
94 | else if (filter->type == BLACKLIST_FILTER_LAST) | |
95 | cmpstr = lastoctet; | |
96 | else | |
97 | { | |
98 | sendto_realops_snomask(SNO_GENERAL, L_ALL, | |
99 | "blacklist_check_reply(): Unknown filtertype (BUG!)"); | |
100 | continue; | |
101 | } | |
102 | ||
103 | if (strcmp(cmpstr, filter->filterstr) == 0) | |
104 | /* Match! */ | |
105 | return 1; | |
106 | } | |
107 | ||
108 | return 0; | |
109 | blwarn: | |
110 | if (blcptr->blacklist->lastwarning + 3600 < rb_current_time()) | |
111 | { | |
112 | sendto_realops_snomask(SNO_GENERAL, L_ALL, | |
113 | "Garbage reply from blacklist %s", | |
114 | blcptr->blacklist->host); | |
115 | blcptr->blacklist->lastwarning = rb_current_time(); | |
116 | } | |
117 | return 0; | |
118 | } | |
119 | ||
212380e3 AC |
120 | static void blacklist_dns_callback(void *vptr, struct DNSReply *reply) |
121 | { | |
122 | struct BlacklistClient *blcptr = (struct BlacklistClient *) vptr; | |
137d856d | 123 | int listed = 0; |
212380e3 AC |
124 | |
125 | if (blcptr == NULL || blcptr->client_p == NULL) | |
126 | return; | |
127 | ||
128 | if (blcptr->client_p->preClient == NULL) | |
129 | { | |
130 | sendto_realops_snomask(SNO_GENERAL, L_ALL, | |
131 | "blacklist_dns_callback(): blcptr->client_p->preClient (%s) is NULL", get_client_name(blcptr->client_p, HIDE_IP)); | |
637c4932 | 132 | rb_free(blcptr); |
212380e3 AC |
133 | return; |
134 | } | |
135 | ||
137d856d JT |
136 | if (reply != NULL) |
137 | { | |
3c93d380 | 138 | if (blacklist_check_reply(blcptr, &reply->addr)) |
96274734 | 139 | listed = TRUE; |
137d856d JT |
140 | } |
141 | ||
212380e3 | 142 | /* they have a blacklist entry for this client */ |
137d856d | 143 | if (listed && blcptr->client_p->preClient->dnsbl_listed == NULL) |
212380e3 AC |
144 | { |
145 | blcptr->client_p->preClient->dnsbl_listed = blcptr->blacklist; | |
146 | /* reference to blacklist moves from blcptr to client_p->preClient... */ | |
147 | } | |
148 | else | |
149 | unref_blacklist(blcptr->blacklist); | |
150 | ||
b2f0da88 | 151 | rb_dlinkDelete(&blcptr->node, &blcptr->client_p->preClient->dnsbl_queries); |
212380e3 AC |
152 | |
153 | /* yes, it can probably happen... */ | |
b2f0da88 | 154 | if (rb_dlink_list_length(&blcptr->client_p->preClient->dnsbl_queries) == 0 && blcptr->client_p->flags & FLAGS_SENTUSER && !EmptyString(blcptr->client_p->name)) |
212380e3 AC |
155 | { |
156 | char buf[USERLEN + 1]; | |
f427c8b0 | 157 | rb_strlcpy(buf, blcptr->client_p->username, sizeof buf); |
212380e3 AC |
158 | register_local_user(blcptr->client_p, blcptr->client_p, buf); |
159 | } | |
160 | ||
637c4932 | 161 | rb_free(blcptr); |
212380e3 AC |
162 | } |
163 | ||
212380e3 AC |
164 | static void initiate_blacklist_dnsquery(struct Blacklist *blptr, struct Client *client_p) |
165 | { | |
eddc2ab6 | 166 | struct BlacklistClient *blcptr = rb_malloc(sizeof(struct BlacklistClient)); |
db3efb7a | 167 | char buf[IRCD_RES_HOSTLEN + 1]; |
5d21ef50 | 168 | uint8_t *ip; |
212380e3 AC |
169 | |
170 | blcptr->blacklist = blptr; | |
171 | blcptr->client_p = client_p; | |
172 | ||
173 | blcptr->dns_query.ptr = blcptr; | |
174 | blcptr->dns_query.callback = blacklist_dns_callback; | |
175 | ||
0a1e77c2 EM |
176 | if ((client_p->localClient->ip.ss_family == AF_INET) && blptr->ipv4) |
177 | { | |
178 | ip = (uint8_t *)&((struct sockaddr_in *)&client_p->localClient->ip)->sin_addr.s_addr; | |
179 | ||
180 | /* becomes 2.0.0.127.torbl.ahbl.org or whatever */ | |
181 | rb_snprintf(buf, sizeof buf, "%d.%d.%d.%d.%s", | |
182 | (unsigned int) ip[3], | |
183 | (unsigned int) ip[2], | |
184 | (unsigned int) ip[1], | |
185 | (unsigned int) ip[0], | |
186 | blptr->host); | |
187 | } | |
188 | /* IPv6 is supported now. --Elizabeth */ | |
189 | else if ((client_p->localClient->ip.ss_family == AF_INET6) && blptr->ipv6) | |
190 | { | |
191 | /* Breaks it into ip[0] = 0x00, ip[1] = 0x00... ip[16] = 0x01 for localhost | |
192 | * I wish there was a uint4_t for C, this would make the below cleaner, but... */ | |
193 | ip = (uint8_t *)&((struct sockaddr_in6 *)&client_p->localClient->ip)->sin6_addr.s6_addr; | |
194 | char *bufptr = buf; | |
195 | int i; | |
196 | ||
197 | /* The below will give us something like | |
198 | * 1.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.foobl.invalid | |
199 | */ | |
200 | ||
201 | /* Going backwards */ | |
202 | for (i = 15; i >= 0; i--) | |
203 | { | |
204 | /* Get upper and lower nibbles (yes this works fine on | |
205 | * both big and little endian) */ | |
206 | uint8_t hi = (ip[i] >> 4) & 0x0F; | |
207 | uint8_t lo = ip[i] & 0x0F; | |
208 | ||
209 | /* One part... (why 5? rb_snprintf adds \0) */ | |
210 | rb_snprintf(bufptr, 5, "%1x.%1x.", | |
211 | (unsigned int) lo, /* Remember, backwards */ | |
212 | (unsigned int) hi); | |
213 | ||
214 | /* Lurch forward to next position */ | |
215 | bufptr += 4; | |
216 | } | |
212380e3 | 217 | |
0a1e77c2 EM |
218 | /* Tack host on */ |
219 | strcpy(bufptr, blptr->host); | |
220 | } | |
221 | /* This shouldn't happen... */ | |
222 | else | |
223 | return; | |
212380e3 AC |
224 | |
225 | gethost_byname_type(buf, &blcptr->dns_query, T_A); | |
226 | ||
b2f0da88 | 227 | rb_dlinkAdd(blcptr, &blcptr->node, &client_p->preClient->dnsbl_queries); |
212380e3 AC |
228 | blptr->refcount++; |
229 | } | |
230 | ||
231 | /* public interfaces */ | |
3c93d380 | 232 | struct Blacklist *new_blacklist(char *name, char *reject_reason, int ipv4, int ipv6, rb_dlink_list *filters) |
212380e3 AC |
233 | { |
234 | struct Blacklist *blptr; | |
235 | ||
236 | if (name == NULL || reject_reason == NULL) | |
237 | return NULL; | |
238 | ||
239 | blptr = find_blacklist(name); | |
240 | if (blptr == NULL) | |
241 | { | |
eddc2ab6 | 242 | blptr = rb_malloc(sizeof(struct Blacklist)); |
b2f0da88 | 243 | rb_dlinkAddAlloc(blptr, &blacklist_list); |
212380e3 AC |
244 | } |
245 | else | |
246 | blptr->status &= ~CONF_ILLEGAL; | |
3c93d380 | 247 | |
db3efb7a | 248 | rb_strlcpy(blptr->host, name, IRCD_RES_HOSTLEN + 1); |
f427c8b0 | 249 | rb_strlcpy(blptr->reject_reason, reject_reason, IRCD_BUFSIZE); |
0a1e77c2 EM |
250 | blptr->ipv4 = ipv4; |
251 | blptr->ipv6 = ipv6; | |
3c93d380 EM |
252 | |
253 | rb_dlinkMoveList(filters, &blptr->filters); | |
254 | ||
96274734 | 255 | blptr->lastwarning = 0; |
212380e3 AC |
256 | |
257 | return blptr; | |
258 | } | |
259 | ||
260 | void unref_blacklist(struct Blacklist *blptr) | |
261 | { | |
3c93d380 EM |
262 | rb_dlink_node *ptr, *next_ptr; |
263 | ||
212380e3 AC |
264 | blptr->refcount--; |
265 | if (blptr->status & CONF_ILLEGAL && blptr->refcount <= 0) | |
266 | { | |
3c93d380 EM |
267 | RB_DLINK_FOREACH_SAFE(ptr, next_ptr, blptr->filters.head) |
268 | { | |
269 | rb_free(ptr); | |
270 | rb_dlinkDelete(ptr, &blptr->filters); | |
271 | } | |
272 | ||
b2f0da88 | 273 | rb_dlinkFindDestroy(blptr, &blacklist_list); |
637c4932 | 274 | rb_free(blptr); |
212380e3 AC |
275 | } |
276 | } | |
277 | ||
278 | void lookup_blacklists(struct Client *client_p) | |
279 | { | |
b2f0da88 | 280 | rb_dlink_node *nptr; |
212380e3 | 281 | |
b2f0da88 | 282 | RB_DLINK_FOREACH(nptr, blacklist_list.head) |
212380e3 AC |
283 | { |
284 | struct Blacklist *blptr = (struct Blacklist *) nptr->data; | |
285 | ||
286 | if (!(blptr->status & CONF_ILLEGAL)) | |
287 | initiate_blacklist_dnsquery(blptr, client_p); | |
288 | } | |
289 | } | |
290 | ||
291 | void abort_blacklist_queries(struct Client *client_p) | |
292 | { | |
637c4932 | 293 | rb_dlink_node *ptr, *next_ptr; |
212380e3 AC |
294 | struct BlacklistClient *blcptr; |
295 | ||
296 | if (client_p->preClient == NULL) | |
297 | return; | |
637c4932 | 298 | RB_DLINK_FOREACH_SAFE(ptr, next_ptr, client_p->preClient->dnsbl_queries.head) |
212380e3 AC |
299 | { |
300 | blcptr = ptr->data; | |
b2f0da88 | 301 | rb_dlinkDelete(&blcptr->node, &client_p->preClient->dnsbl_queries); |
212380e3 AC |
302 | unref_blacklist(blcptr->blacklist); |
303 | delete_resolver_queries(&blcptr->dns_query); | |
637c4932 | 304 | rb_free(blcptr); |
212380e3 AC |
305 | } |
306 | } | |
307 | ||
308 | void destroy_blacklists(void) | |
309 | { | |
637c4932 | 310 | rb_dlink_node *ptr, *next_ptr; |
212380e3 AC |
311 | struct Blacklist *blptr; |
312 | ||
637c4932 | 313 | RB_DLINK_FOREACH_SAFE(ptr, next_ptr, blacklist_list.head) |
212380e3 AC |
314 | { |
315 | blptr = ptr->data; | |
316 | blptr->hits = 0; /* keep it simple and consistent */ | |
317 | if (blptr->refcount > 0) | |
318 | blptr->status |= CONF_ILLEGAL; | |
319 | else | |
320 | { | |
637c4932 | 321 | rb_free(ptr->data); |
b2f0da88 | 322 | rb_dlinkDestroy(ptr, &blacklist_list); |
212380e3 AC |
323 | } |
324 | } | |
325 | } |