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comparison src/lookup.c @ 10:26e34ae9a3e3

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changed indention and line wrapping to a more consistent style
author meillo@marmaro.de
date Mon, 27 Oct 2008 16:23:10 +0100
parents 08114f7dcc23
children f671821d8222
comparison
equal deleted inserted replaced
9:31cc8a89cb74 10:26e34ae9a3e3
2 * 2 *
3 * This program is free software; you can redistribute it and/or modify 3 * This program is free software; you can redistribute it and/or modify
4 * it under the terms of the GNU General Public License as published by 4 * it under the terms of the GNU General Public License as published by
5 * the Free Software Foundation; either version 2 of the License, or 5 * the Free Software Foundation; either version 2 of the License, or
6 * (at your option) any later version. 6 * (at your option) any later version.
7 * 7 *
8 * This program is distributed in the hope that it will be useful, 8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of 9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details. 11 * GNU General Public License for more details.
12 * 12 *
31 #endif 31 #endif
32 32
33 #ifdef ENABLE_RESOLVER 33 #ifdef ENABLE_RESOLVER
34 34
35 static union { 35 static union {
36 HEADER hdr; 36 HEADER hdr;
37 unsigned char buf[PACKETSZ]; 37 unsigned char buf[PACKETSZ];
38 } response; 38 } response;
39 static unsigned char *resp_end; 39 static unsigned char *resp_end;
40 static unsigned char *resp_pos; 40 static unsigned char *resp_pos;
41 41
42 static int num_answers; 42 static int num_answers;
43 static char name[MAX_DNSNAME]; 43 static char name[MAX_DNSNAME];
44 44
45 unsigned short rr_type; 45 unsigned short rr_type;
46 unsigned short rr_dlen; 46 unsigned short rr_dlen;
47 47
48 static 48 static unsigned short
49 unsigned short getshort(unsigned char *c) 49 getshort(unsigned char *c)
50 { 50 {
51 unsigned short u; 51 unsigned short u;
52 u = c[0]; 52 u = c[0];
53 return (u << 8) + c[1]; 53 return (u << 8) + c[1];
54 } 54 }
55 55
56 static 56 static int
57 int dns_resolve(char *domain, int type, gboolean do_search) 57 dns_resolve(char *domain, int type, gboolean do_search)
58 { 58 {
59 int n; 59 int n;
60 int i; 60 int i;
61 61
62 int resp_len; 62 int resp_len;
63 /*errno = 0;*/ 63 /*errno = 0; */
64 64
65 /* 65 /*
66 if (!stralloc_copy(&glue,domain)) return DNS_MEM; 66 if (!stralloc_copy(&glue,domain)) return DNS_MEM;
67 if (!stralloc_0(&glue)) return DNS_MEM; 67 if (!stralloc_0(&glue)) return DNS_MEM;
68 */ 68 */
69 69
70 // resp_len = res_query(domain, C_IN, type, response.buf, sizeof(response)); 70 // resp_len = res_query(domain, C_IN, type, response.buf, sizeof(response));
71 DEBUG(5) debugf("DNS: before res_search()\n"); 71 DEBUG(5) debugf("DNS: before res_search()\n");
72 if(do_search) 72 if (do_search)
73 resp_len = res_search(domain, C_IN, type, response.buf, sizeof(response)); 73 resp_len = res_search(domain, C_IN, type, response.buf, sizeof(response));
74 else 74 else
75 resp_len = res_query(domain, C_IN, type, response.buf, sizeof(response)); 75 resp_len = res_query(domain, C_IN, type, response.buf, sizeof(response));
76 DEBUG(5) debugf("DBG: after res_search()\n"); 76 DEBUG(5) debugf("DBG: after res_search()\n");
77 77
78 if (resp_len <= 0){ 78 if (resp_len <= 0) {
79 /* 79 /*
80 if (errno == ECONNREFUSED) return DNS_SOFT; 80 if (errno == ECONNREFUSED) return DNS_SOFT;
81 if (h_errno == TRY_AGAIN) return DNS_SOFT; 81 if (h_errno == TRY_AGAIN) return DNS_SOFT;
82 return DNS_HARD; 82 return DNS_HARD;
83 */ 83 */
84 return -1; 84 return -1;
85 } 85 }
86 if (resp_len >= sizeof(response)) 86 if (resp_len >= sizeof(response))
87 resp_len = sizeof(response); 87 resp_len = sizeof(response);
88 88
89 resp_end = response.buf + resp_len; 89 resp_end = response.buf + resp_len;
90 resp_pos = response.buf + sizeof(HEADER); 90 resp_pos = response.buf + sizeof(HEADER);
91 n = ntohs(response.hdr.qdcount); 91 n = ntohs(response.hdr.qdcount);
92 92
93 while (n-- > 0){ 93 while (n-- > 0) {
94 i = dn_expand(response.buf, resp_end, resp_pos, name, MAX_DNSNAME); 94 i = dn_expand(response.buf, resp_end, resp_pos, name, MAX_DNSNAME);
95 if (i < 0) 95 if (i < 0)
96 return -1;
97 DEBUG(5) debugf("DBG: resolve name = %s\n", name);
98 resp_pos += i;
99 i = resp_end - resp_pos;
100 if (i < QFIXEDSZ)
101 return -1;
102 resp_pos += QFIXEDSZ;
103 }
104 num_answers = ntohs(response.hdr.ancount);
105
106 return 0;
107 }
108
109 static int
110 dns_next()
111 {
112 int i;
113
114 if (num_answers <= 0)
115 return 2;
116 num_answers--;
117
118 if (resp_pos == resp_end)
119 return -1; /* soft */
120
121 i = dn_expand(response.buf, resp_end, resp_pos, name, 256);
122 if (i < 0)
123 return -1; /* soft */
124 resp_pos += i;
125
126 i = resp_end - resp_pos;
127 if (i < 4 + 3 * 2)
128 return -1; /* soft */
129
130 rr_type = getshort(resp_pos);
131 rr_dlen = getshort(resp_pos + 8);
132 resp_pos += 10;
133
134 return 0;
135 }
136
137 static int
138 dns_getip(guint32 * ip)
139 {
140 int ret;
141
142 if ((ret = dns_next()))
143 return ret;
144
145 if (rr_type == T_A) {
146 if (rr_dlen < 4)
147 return -1; /* soft */
148 *ip = *(guint32 *) (resp_pos);
149 DEBUG(5) debugf("DNS: dns_getip(): ip = %s\n", inet_ntoa(*(struct in_addr *) ip));
150 resp_pos += rr_dlen;
151
152 return 1;
153 }
154 resp_pos += rr_dlen;
155 return 0;
156 }
157
158 static int
159 dns_getmx(int *pref)
160 {
161 int ret;
162
163 if ((ret = dns_next()))
164 return ret;
165
166 if (rr_type == T_MX) {
167 if (rr_dlen < 3)
168 return -1; /* soft */
169
170 *pref = (resp_pos[0] << 8) + resp_pos[1];
171 if (dn_expand(response.buf, resp_end, resp_pos + 2, name, MAX_DNSNAME) < 0)
172 return -1;
173
174 resp_pos += rr_dlen;
175
176 return 1;
177 }
178 resp_pos += rr_dlen;
179 return 0;
180 }
181
182 /*
183 static int
184 dns_getname(int type)
185 {
186 int ret;
187
188 if((ret = dns_next())) return ret;
189
190 if (rr_type == type){
191 if (dn_expand(response.buf, resp_end, resp_pos, name, MAX_DNSNAME) < 0)
96 return -1; 192 return -1;
97 DEBUG(5) debugf("DBG: resolve name = %s\n", name); 193
98 resp_pos += i;
99 i = resp_end - resp_pos;
100 if (i < QFIXEDSZ)
101 return -1;
102 resp_pos += QFIXEDSZ;
103 }
104 num_answers = ntohs(response.hdr.ancount);
105
106 return 0;
107 }
108
109 static int dns_next()
110 {
111 int i;
112
113 if (num_answers <= 0) return 2;
114 num_answers--;
115
116 if (resp_pos == resp_end)
117 return -1 /* soft */;
118
119 i = dn_expand(response.buf, resp_end, resp_pos, name, 256);
120 if (i < 0)
121 return -1; /* soft */
122 resp_pos += i;
123
124 i = resp_end - resp_pos;
125 if (i < 4 + 3 * 2)
126 return -1; /* soft */
127
128 rr_type = getshort(resp_pos);
129 rr_dlen = getshort(resp_pos + 8);
130 resp_pos += 10;
131
132 return 0;
133 }
134
135 static
136 int dns_getip(guint32 *ip)
137 {
138 int ret;
139
140 if((ret = dns_next())) return ret;
141
142 if (rr_type == T_A){
143 if (rr_dlen < 4)
144 return -1; /* soft */
145 *ip = *(guint32 *)(resp_pos);
146 DEBUG(5) debugf("DNS: dns_getip(): ip = %s\n", inet_ntoa(*(struct in_addr*)ip));
147 resp_pos += rr_dlen; 194 resp_pos += rr_dlen;
148 195
149 return 1; 196 return 1;
150 } 197 }
151 resp_pos += rr_dlen; 198 resp_pos += rr_dlen;
152 return 0; 199 return 0;
153 } 200 }
154
155 static
156 int dns_getmx(int *pref)
157 {
158 int ret;
159
160 if((ret = dns_next())) return ret;
161
162 if (rr_type == T_MX){
163 if (rr_dlen < 3)
164 return -1; /* soft */
165
166 *pref = (resp_pos[0] << 8) + resp_pos[1];
167 if (dn_expand(response.buf, resp_end, resp_pos + 2, name, MAX_DNSNAME) < 0)
168 return -1;
169
170 resp_pos += rr_dlen;
171
172 return 1;
173 }
174 resp_pos += rr_dlen;
175 return 0;
176 }
177
178 /*
179 static
180 int dns_getname(int type)
181 {
182 int ret;
183
184 if((ret = dns_next())) return ret;
185
186 if (rr_type == type){
187 if (dn_expand(response.buf, resp_end, resp_pos, name, MAX_DNSNAME) < 0)
188 return -1;
189
190 resp_pos += rr_dlen;
191
192 return 1;
193 }
194 resp_pos += rr_dlen;
195 return 0;
196 }
197 */ 201 */
198 202
199 static 203 static int
200 int dns_look_ip(gchar *domain, guint32 *ip) 204 dns_look_ip(gchar * domain, guint32 * ip)
201 { 205 {
202 gchar *n = domain; 206 gchar *n = domain;
203 207
204 while(TRUE){ 208 while (TRUE) {
205 if(dns_resolve(n, T_A, FALSE) == 0){ 209 if (dns_resolve(n, T_A, FALSE) == 0) {
206 dns_next(); 210 dns_next();
207 if(rr_type == T_A){ 211 if (rr_type == T_A) {
208 if (rr_dlen < 4) 212 if (rr_dlen < 4)
209 return -1; /* soft */ 213 return -1; /* soft */
210 *ip = *(guint32 *)(resp_pos); 214 *ip = *(guint32 *) (resp_pos);
211 215
212 DEBUG(5) debugf("DNS: dns_look_ip(): ip = %s\n", 216 DEBUG(5) debugf("DNS: dns_look_ip(): ip = %s\n", inet_ntoa(*(struct in_addr *) ip));
213 inet_ntoa(*(struct in_addr*)ip)); 217
214 218 resp_pos += rr_dlen;
215 resp_pos += rr_dlen; 219 return 0;
216 return 0; 220 } else if (rr_type == T_CNAME) {
217 }else if(rr_type == T_CNAME){ 221 if (dn_expand(response.buf, resp_end, resp_pos, name, MAX_DNSNAME) < 0)
218 if (dn_expand(response.buf, resp_end, resp_pos, name, MAX_DNSNAME) < 0) 222 return -1;
219 return -1; 223
220 224 DEBUG(5) debugf("DNS: (CNAME) dns_look_ip(): name = %s\n", name);
221 DEBUG(5) debugf("DNS: (CNAME) dns_look_ip(): name = %s\n", name); 225
222 226 resp_pos += rr_dlen;
223 resp_pos += rr_dlen; 227 n = name;
224 n = name; 228 } else
225 }else 229 return -1;
226 return -1; 230 } else
227 }else 231 return -1;
228 return -1; 232 }
229 } 233 }
230 } 234
231 235 GList*
232 GList *resolve_dns_a(GList *list, gchar *domain) 236 resolve_dns_a(GList * list, gchar * domain)
233 { 237 {
234 int ret; 238 int ret;
235 239
236 DEBUG(5) debugf("DNS: resolve_dns_a entered\n"); 240 DEBUG(5) debugf("DNS: resolve_dns_a entered\n");
237 241
238 if(dns_resolve(domain, T_A, TRUE) == 0){ 242 if (dns_resolve(domain, T_A, TRUE) == 0) {
239 mxip_addr mxip; 243 mxip_addr mxip;
240 while((ret = dns_getip(&(mxip.ip))) != 2){ 244 while ((ret = dns_getip(&(mxip.ip))) != 2) {
241 if(ret == 1){ 245 if (ret == 1) {
242 mxip.name = g_strdup(name); 246 mxip.name = g_strdup(name);
243 mxip.pref = 0; 247 mxip.pref = 0;
244 list = g_list_append(list, g_memdup(&mxip, sizeof(mxip))); 248 list = g_list_append(list, g_memdup(&mxip, sizeof(mxip)));
245 } 249 }
246 } 250 }
247 } 251 }
248 return list; 252 return list;
249 } 253 }
250 254
251 static 255 static gint
252 gint _mx_sort_func(gconstpointer aa, gconstpointer bb) 256 _mx_sort_func(gconstpointer aa, gconstpointer bb)
253 { 257 {
254 const mxip_addr *a = (mxip_addr *)aa; 258 const mxip_addr *a = (mxip_addr *) aa;
255 const mxip_addr *b = (mxip_addr *)bb; 259 const mxip_addr *b = (mxip_addr *) bb;
256 260
257 if(a->pref == b->pref) 261 if (a->pref == b->pref)
258 return a->ip - b->ip; 262 return a->ip - b->ip;
259 else 263 else
260 return a->pref - b->pref; 264 return a->pref - b->pref;
261 } 265 }
262 266
263 GList *resolve_dns_mx(GList *list, gchar *domain) 267 GList*
264 { 268 resolve_dns_mx(GList * list, gchar * domain)
265 GList *node; 269 {
266 int ret; 270 GList *node;
267 int cnt = 0; 271 int ret;
268 272 int cnt = 0;
269 DEBUG(5) debugf("DNS: resolve_dns_mx entered\n"); 273
270 274 DEBUG(5) debugf("DNS: resolve_dns_mx entered\n");
271 if(dns_resolve(domain, T_MX, TRUE) == 0){ 275
272 GList *node_next; 276 if (dns_resolve(domain, T_MX, TRUE) == 0) {
273 mxip_addr mxip; 277 GList *node_next;
274 while((ret = dns_getmx(&(mxip.pref))) != 2){ 278 mxip_addr mxip;
275 if(ret == 1){ 279 while ((ret = dns_getmx(&(mxip.pref))) != 2) {
276 mxip.name = g_strdup(name); 280 if (ret == 1) {
277 mxip.ip = rand(); 281 mxip.name = g_strdup(name);
278 list = g_list_append(list, g_memdup(&mxip, sizeof(mxip))); 282 mxip.ip = rand();
279 cnt++; 283 list = g_list_append(list, g_memdup(&mxip, sizeof(mxip)));
280 } 284 cnt++;
281 } 285 }
282 286 }
283 DEBUG(5) debugf("DNS: found %d mx records\n", cnt); 287
284 288 DEBUG(5) debugf("DNS: found %d mx records\n", cnt);
285 /* to randomize sequences with equal pref values, 289
286 we temporarily 'misused' the ip field and 290 /* to randomize sequences with equal pref values,
287 put a random number in it as a secondary sort key. 291 we temporarily 'misused' the ip field and
288 */ 292 put a random number in it as a secondary sort key.
289 list = g_list_sort(list, _mx_sort_func); 293 */
290 294 list = g_list_sort(list, _mx_sort_func);
291 /* CNAME resolving has to be added as well. */ 295
292 296 /* CNAME resolving has to be added as well. */
293 for(node = g_list_first(list); 297
294 node != NULL; 298 for (node = g_list_first(list); node != NULL; node = node_next) {
295 node = node_next){ 299
296 300 mxip_addr *p_mxip = (mxip_addr *) (node->data);
297 mxip_addr *p_mxip = (mxip_addr *)(node->data); 301 node_next = g_list_next(node);
298 node_next = g_list_next(node); 302
299 303 if (dns_look_ip(p_mxip->name, &(p_mxip->ip)) != 0) {
300 if(dns_look_ip(p_mxip->name, &(p_mxip->ip)) != 0){ 304 DEBUG(1) debugf("DNS: could not resolve target of mx %s\n", p_mxip->name);
301 DEBUG(1) debugf("DNS: could not resolve target of mx %s\n", p_mxip->name); 305 list = g_list_remove_link(list, node);
302 list = g_list_remove_link(list, node); 306 g_free(node->data);
303 g_free(node->data); 307 g_list_free_1(node);
304 g_list_free_1(node); 308 }
305 } 309 }
306 } 310 }
307 } 311 return list;
308 return list;
309 } 312 }
310 313
311 #endif 314 #endif
312 315
313 /* now something completely different... */ 316 /* now something completely different... */
314 317
315 GList *resolve_byname(GList *list, gchar *domain) 318 GList*
316 { 319 resolve_byname(GList * list, gchar * domain)
317 struct hostent *hent; 320 {
318 321 struct hostent *hent;
319 DEBUG(5) debugf("DNS: resolve_byname entered\n"); 322
320 323 DEBUG(5) debugf("DNS: resolve_byname entered\n");
321 if((hent = gethostbyname(domain))){ 324
322 char *haddr; 325 if ((hent = gethostbyname(domain))) {
323 int i = 0; 326 char *haddr;
324 while((haddr = hent->h_addr_list[i++])){ 327 int i = 0;
325 mxip_addr mxip; 328 while ((haddr = hent->h_addr_list[i++])) {
326 mxip.ip = *(guint32 *)(haddr); 329 mxip_addr mxip;
327 mxip.pref = 0; 330 mxip.ip = *(guint32 *) (haddr);
328 mxip.name = g_strdup(hent->h_name); 331 mxip.pref = 0;
329 list = g_list_append(list, g_memdup(&mxip, sizeof(mxip))); 332 mxip.name = g_strdup(hent->h_name);
330 } 333 list = g_list_append(list, g_memdup(&mxip, sizeof(mxip)));
331 } 334 }
332 return list; 335 }
336 return list;
333 } 337 }
334 338
335 #ifdef RESOLV_TEST 339 #ifdef RESOLV_TEST
336 int main(int argc, char *argv[]) 340 int
337 { 341 main(int argc, char *argv[])
338 GList *addr_list = NULL, *node; 342 {
339 343 GList *addr_list = NULL, *node;
340 g_print("starting res_init()\n"); 344
341 345 g_print("starting res_init()\n");
342 g_print("retrans = %d, retry = %d\n", _res.retrans, _res.retry); 346
343 347 g_print("retrans = %d, retry = %d\n", _res.retrans, _res.retry);
344 if(res_init() == 0){ 348
345 349 if (res_init() == 0) {
346 addr_list = resolve_dns_a(NULL, argv[1]); 350
347 g_print("A:\n"); 351 addr_list = resolve_dns_a(NULL, argv[1]);
348 352 g_print("A:\n");
349 foreach(addr_list, node){ 353
350 mxip_addr *p_mxip = (mxip_addr *)(node->data); 354 foreach(addr_list, node) {
351 355 mxip_addr *p_mxip = (mxip_addr *) (node->data);
352 printf("name = %s\n IP = %s\n", 356
353 p_mxip->name, 357 printf("name = %s\n IP = %s\n", p_mxip->name, inet_ntoa(*(struct in_addr *) &(p_mxip->ip)));
354 inet_ntoa(*(struct in_addr *)&(p_mxip->ip))); 358 }
355 } 359 addr_list = resolve_dns_mx(NULL, argv[1]);
356 addr_list = resolve_dns_mx(NULL, argv[1]); 360 g_print("MX:\n");
357 g_print("MX:\n"); 361
358 362 foreach(addr_list, node) {
359 foreach(addr_list, node){ 363 mxip_addr *p_mxip = (mxip_addr *) (node->data);
360 mxip_addr *p_mxip = (mxip_addr *)(node->data); 364
361 365 printf("name = %s\n IP = %s pref = %d\n", p_mxip->name, inet_ntoa(*(struct in_addr *) &(p_mxip->ip)), p_mxip->pref);
362 printf("name = %s\n IP = %s pref = %d\n", 366 }
363 p_mxip->name, 367 {
364 inet_ntoa(*(struct in_addr *)&(p_mxip->ip)), 368 guint32 ip;
365 p_mxip->pref); 369 dns_look_ip(argv[1], &ip);
366 } 370 printf("dns_look_ip: %s\n", inet_ntoa(*((struct in_addr *) (&ip))));
367 { 371 }
368 guint32 ip; 372 } else
369 dns_look_ip(argv[1], &ip); 373 printf("res_init() failed.\n");
370 printf("dns_look_ip: %s\n", inet_ntoa(*((struct in_addr *)(&ip)))); 374
371 }
372 }else
373 printf("res_init() failed.\n");
374
375 } 375 }
376 #endif 376 #endif