masqmail

view src/lookup.c @ 421:f37384470855

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Changed lockdir to /var/lock/masqmail; Create lockdir and piddir on startup. Moved the lockdir out of the spool dir. (When /var/lock is a ramdisk we do well to have the lock files there.) Added the new configure option --with-lockdir to change that location. Nontheless, if we run_as_user, then lock files are always stored in the spool dir directly. Instead of installing the lockdir and piddir at installation time, we create them on startup time now if they are missing. This is necessary if lockdir or piddir are a tmpfs.
author markus schnalke <meillo@marmaro.de>
date Wed, 30 May 2012 09:38:38 +0200
parents 41958685480d
children
line source
1 /*
2 ** MasqMail
3 ** Copyright (C) Oliver Kurth
4 ** Copyright (C) markus schnalke <meillo@marmaro.de>
5 **
6 ** This program is free software; you can redistribute it and/or modify
7 ** it under the terms of the GNU General Public License as published by
8 ** the Free Software Foundation; either version 2 of the License, or
9 ** (at your option) any later version.
10 **
11 ** This program is distributed in the hope that it will be useful,
12 ** but WITHOUT ANY WARRANTY; without even the implied warranty of
13 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 ** GNU General Public License for more details.
15 **
16 ** You should have received a copy of the GNU General Public License
17 ** along with this program; if not, write to the Free Software
18 ** Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 */
20
21 #include <sys/types.h>
22 #include <netinet/in.h>
23 #include <arpa/nameser.h>
24 #include <resolv.h>
25
26 #include "masqmail.h"
27
28
29 #ifdef ENABLE_RESOLVER
30
31 static union {
32 HEADER hdr;
33 unsigned char buf[PACKETSZ];
34 } response;
35 static unsigned char *resp_end;
36 static unsigned char *resp_pos;
37
38 static int num_answers;
39 static char name[MAX_DNSNAME];
40
41 unsigned short rr_type;
42 unsigned short rr_dlen;
43
44 static unsigned short
45 getshort(unsigned char *c)
46 {
47 unsigned short u;
48 u = c[0];
49 return (u << 8) + c[1];
50 }
51
52 static int
53 dns_resolve(char *domain, int type, gboolean do_search)
54 {
55 int n;
56 int i;
57 int resp_len;
58
59 DEBUG(5) debugf("DNS: before res_search()\n");
60 if (do_search)
61 resp_len = res_search(domain, C_IN, type, response.buf, sizeof(response));
62 else
63 resp_len = res_query(domain, C_IN, type, response.buf, sizeof(response));
64 DEBUG(5) debugf("DBG: after res_search()\n");
65
66 if (resp_len <= 0) {
67 /*
68 ** if (errno == ECONNREFUSED) return DNS_SOFT;
69 ** if (h_errno == TRY_AGAIN) return DNS_SOFT;
70 ** return DNS_HARD;
71 */
72 return -1;
73 }
74 if (resp_len >= sizeof(response))
75 resp_len = sizeof(response);
76
77 resp_end = response.buf + resp_len;
78 resp_pos = response.buf + sizeof(HEADER);
79 n = ntohs(response.hdr.qdcount);
80
81 while (n-- > 0) {
82 i = dn_expand(response.buf, resp_end, resp_pos, name, MAX_DNSNAME);
83 if (i < 0)
84 return -1;
85 DEBUG(5) debugf("DBG: resolve name = %s\n", name);
86 resp_pos += i;
87 i = resp_end - resp_pos;
88 if (i < QFIXEDSZ)
89 return -1;
90 resp_pos += QFIXEDSZ;
91 }
92 num_answers = ntohs(response.hdr.ancount);
93
94 return 0;
95 }
96
97 static int
98 dns_next()
99 {
100 int i;
101
102 if (num_answers <= 0)
103 return 2;
104 num_answers--;
105
106 if (resp_pos == resp_end)
107 return -1; /* soft */
108
109 i = dn_expand(response.buf, resp_end, resp_pos, name, 256);
110 if (i < 0)
111 return -1; /* soft */
112 resp_pos += i;
113
114 i = resp_end - resp_pos;
115 if (i < 4 + 3 * 2)
116 return -1; /* soft */
117
118 rr_type = getshort(resp_pos);
119 rr_dlen = getshort(resp_pos + 8);
120 resp_pos += 10;
121
122 return 0;
123 }
124
125 static int
126 dns_getip(guint32 *ip)
127 {
128 int ret;
129
130 if ((ret = dns_next()))
131 return ret;
132
133 if (rr_type == T_A) {
134 if (rr_dlen < 4)
135 return -1; /* soft */
136 *ip = *(guint32 *) (resp_pos);
137 DEBUG(5) debugf("DNS: dns_getip(): ip = %s\n", inet_ntoa(*(struct in_addr *) ip));
138 resp_pos += rr_dlen;
139
140 return 1;
141 }
142 resp_pos += rr_dlen;
143 return 0;
144 }
145
146 static int
147 dns_getmx(int *pref)
148 {
149 int ret;
150
151 if ((ret = dns_next()))
152 return ret;
153
154 if (rr_type == T_MX) {
155 if (rr_dlen < 3)
156 return -1; /* soft */
157
158 *pref = (resp_pos[0] << 8) + resp_pos[1];
159 if (dn_expand(response.buf, resp_end, resp_pos + 2, name, MAX_DNSNAME) < 0)
160 return -1;
161
162 resp_pos += rr_dlen;
163
164 return 1;
165 }
166 resp_pos += rr_dlen;
167 return 0;
168 }
169
170 int
171 dns_look_ip(gchar *domain, guint32 *ip)
172 {
173 gchar *n = domain;
174
175 while (TRUE) {
176 if (dns_resolve(n, T_A, FALSE) != 0) {
177 return -1;
178 }
179
180 dns_next();
181 if (rr_type == T_A) {
182 if (rr_dlen < 4) {
183 return -1; /* soft */
184 }
185 *ip = *(guint32 *) (resp_pos);
186
187 DEBUG(5) debugf("DNS: dns_look_ip(): ip = %s\n", inet_ntoa(*(struct in_addr *) ip));
188
189 resp_pos += rr_dlen;
190 return 0;
191 } else if (rr_type == T_CNAME) {
192 if (dn_expand(response.buf, resp_end, resp_pos, name, MAX_DNSNAME) < 0) {
193 return -1;
194 }
195
196 DEBUG(5) debugf("DNS: (CNAME) dns_look_ip(): name = %s\n", name);
197
198 resp_pos += rr_dlen;
199 n = name;
200 } else {
201 return -1;
202 }
203 }
204 }
205
206 GList*
207 resolve_dns_a(GList *list, gchar *domain)
208 {
209 int ret;
210
211 DEBUG(5) debugf("DNS: resolve_dns_a entered\n");
212
213 if (dns_resolve(domain, T_A, TRUE) == 0) {
214 mxip_addr mxip;
215 while ((ret = dns_getip(&(mxip.ip))) != 2) {
216 if (ret == 1) {
217 mxip.name = g_strdup(name);
218 mxip.pref = 0;
219 list = g_list_append(list, g_memdup(&mxip, sizeof(mxip)));
220 }
221 }
222 }
223 return list;
224 }
225
226 static gint
227 _mx_sort_func(gconstpointer aa, gconstpointer bb)
228 {
229 const mxip_addr *a = (mxip_addr *) aa;
230 const mxip_addr *b = (mxip_addr *) bb;
231
232 if (a->pref == b->pref)
233 return a->ip - b->ip;
234 else
235 return a->pref - b->pref;
236 }
237
238 GList*
239 resolve_dns_mx(GList *list, gchar *domain)
240 {
241 GList *node;
242 int ret;
243 int cnt = 0;
244
245 DEBUG(5) debugf("DNS: resolve_dns_mx entered\n");
246
247 if (dns_resolve(domain, T_MX, TRUE) == 0) {
248 GList *node_next;
249 mxip_addr mxip;
250 while ((ret = dns_getmx(&(mxip.pref))) != 2) {
251 if (ret == 1) {
252 mxip.name = g_strdup(name);
253 mxip.ip = rand();
254 list = g_list_append(list, g_memdup(&mxip, sizeof(mxip)));
255 cnt++;
256 }
257 }
258
259 DEBUG(5) debugf("DNS: found %d mx records\n", cnt);
260
261 /*
262 ** to randomize sequences with equal pref values,
263 ** we temporarily 'misused' the ip field and
264 ** put a random number in it as a secondary sort key.
265 */
266 list = g_list_sort(list, _mx_sort_func);
267
268 /* CNAME resolving has to be added as well. */
269
270 for (node = g_list_first(list); node != NULL; node = node_next) {
271
272 mxip_addr *p_mxip = (mxip_addr *) (node->data);
273 node_next = g_list_next(node);
274
275 if (dns_look_ip(p_mxip->name, &(p_mxip->ip)) != 0) {
276 DEBUG(1) debugf("DNS: could not resolve target of mx %s\n", p_mxip->name);
277 list = g_list_remove_link(list, node);
278 g_free(node->data);
279 g_list_free_1(node);
280 }
281 }
282 }
283 return list;
284 }
285
286 #endif
287
288 /* now something completely different... */
289
290 GList*
291 resolve_byname(GList *list, gchar *domain)
292 {
293 struct hostent *hent;
294
295 DEBUG(5) debugf("DNS: resolve_byname entered\n");
296
297 if ((hent = gethostbyname(domain))) {
298 char *haddr;
299 int i = 0;
300 while ((haddr = hent->h_addr_list[i++])) {
301 mxip_addr mxip;
302 mxip.ip = *(guint32 *) (haddr);
303 mxip.pref = 0;
304 mxip.name = g_strdup(hent->h_name);
305 list = g_list_append(list, g_memdup(&mxip, sizeof(mxip)));
306 }
307 }
308 return list;
309 }