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47 # include "sm_resolve.h"
49 SM_RCSID("$Id: sm_resolve.c,v 8.24.4.7 2003/03/22 22:55:37 ca Exp $")
62 # endif /* NETINET6 */
74 ** DNS_STRING_TO_TYPE -- convert resource record name into type
77 ** name -- name of resource record type
85 dns_string_to_type(name)
88 struct stot *p = stot;
90 for (p = stot; p->st_name != NULL; p++)
91 if (sm_strcasecmp(name, p->st_name) == 0)
97 ** DNS_TYPE_TO_STRING -- convert resource record type into name
100 ** type -- resource record type
103 ** name if succeeded.
108 dns_type_to_string(type)
111 struct stot *p = stot;
113 for (p = stot; p->st_name != NULL; p++)
114 if (type == p->st_type)
120 ** DNS_FREE_DATA -- free all components of a DNS_REPLY_T
123 ** r -- pointer to DNS_REPLY_T
133 RESOURCE_RECORD_T *rr;
135 if (r->dns_r_q.dns_q_domain != NULL)
136 sm_free(r->dns_r_q.dns_q_domain);
137 for (rr = r->dns_r_head; rr != NULL; )
139 RESOURCE_RECORD_T *tmp = rr;
141 if (rr->rr_domain != NULL)
142 sm_free(rr->rr_domain);
143 if (rr->rr_u.rr_data != NULL)
144 sm_free(rr->rr_u.rr_data);
152 ** PARSE_DNS_REPLY -- parse DNS reply data.
155 ** data -- pointer to dns data
156 ** len -- len of data
159 ** pointer to DNS_REPLY_T if succeeded.
164 parse_dns_reply(data, len)
171 char host[MAXHOSTNAMELEN];
173 RESOURCE_RECORD_T **rr;
175 r = (DNS_REPLY_T *) sm_malloc(sizeof(*r));
178 memset(r, 0, sizeof(*r));
182 /* doesn't work on Crays? */
183 memcpy(&r->dns_r_h, p, sizeof(r->dns_r_h));
184 p += sizeof(r->dns_r_h);
185 status = dn_expand(data, data + len, p, host, sizeof host);
191 r->dns_r_q.dns_q_domain = sm_strdup(host);
192 if (r->dns_r_q.dns_q_domain == NULL)
198 GETSHORT(r->dns_r_q.dns_q_type, p);
199 GETSHORT(r->dns_r_q.dns_q_class, p);
201 while (p < data + len)
203 int type, class, ttl, size, txtlen;
205 status = dn_expand(data, data + len, p, host, sizeof host);
216 if (p + size > data + len)
219 ** announced size of data exceeds length of
220 ** data paket: someone is cheating.
224 sm_syslog(LOG_WARNING, NOQID,
225 "ERROR: DNS RDLENGTH=%d > data len=%d",
226 size, len - (p - data));
230 *rr = (RESOURCE_RECORD_T *) sm_malloc(sizeof(**rr));
236 memset(*rr, 0, sizeof(**rr));
237 (*rr)->rr_domain = sm_strdup(host);
238 if ((*rr)->rr_domain == NULL)
243 (*rr)->rr_type = type;
244 (*rr)->rr_class = class;
246 (*rr)->rr_size = size;
252 status = dn_expand(data, data + len, p, host,
259 (*rr)->rr_u.rr_txt = sm_strdup(host);
260 if ((*rr)->rr_u.rr_txt == NULL)
269 status = dn_expand(data, data + len, p + 2, host,
276 l = strlen(host) + 1;
277 (*rr)->rr_u.rr_mx = (MX_RECORD_T *)
278 sm_malloc(sizeof(*((*rr)->rr_u.rr_mx)) + l);
279 if ((*rr)->rr_u.rr_mx == NULL)
284 (*rr)->rr_u.rr_mx->mx_r_preference = (p[0] << 8) | p[1];
285 (void) sm_strlcpy((*rr)->rr_u.rr_mx->mx_r_domain,
290 status = dn_expand(data, data + len, p + 6, host,
297 l = strlen(host) + 1;
298 (*rr)->rr_u.rr_srv = (SRV_RECORDT_T*)
299 sm_malloc(sizeof(*((*rr)->rr_u.rr_srv)) + l);
300 if ((*rr)->rr_u.rr_srv == NULL)
305 (*rr)->rr_u.rr_srv->srv_r_priority = (p[0] << 8) | p[1];
306 (*rr)->rr_u.rr_srv->srv_r_weight = (p[2] << 8) | p[3];
307 (*rr)->rr_u.rr_srv->srv_r_port = (p[4] << 8) | p[5];
308 (void) sm_strlcpy((*rr)->rr_u.rr_srv->srv_r_target,
315 ** The TXT record contains the length as
316 ** leading byte, hence the value is restricted
317 ** to 255, which is less than the maximum value
318 ** of RDLENGTH (size). Nevertheless, txtlen
319 ** must be less than size because the latter
320 ** specifies the length of the entire TXT
328 sm_syslog(LOG_WARNING, NOQID,
329 "ERROR: DNS TXT record size=%d <= text len=%d",
334 (*rr)->rr_u.rr_txt = (char *) sm_malloc(txtlen + 1);
335 if ((*rr)->rr_u.rr_txt == NULL)
340 (void) sm_strlcpy((*rr)->rr_u.rr_txt, (char*) p + 1,
345 (*rr)->rr_u.rr_data = (unsigned char*) sm_malloc(size);
346 if ((*rr)->rr_u.rr_data == NULL)
351 (void) memcpy((*rr)->rr_u.rr_data, p, size);
355 rr = &(*rr)->rr_next;
362 ** DNS_LOOKUP_INT -- perform dns map lookup (internal helper routine)
365 ** domain -- name to lookup
366 ** rr_class -- resource record class
367 ** rr_type -- resource record type
368 ** retrans -- retransmission timeout
369 ** retry -- number of retries
372 ** result of lookup if succeeded.
377 dns_lookup_int(domain, rr_class, rr_type, retrans, retry)
385 unsigned long old_options = 0;
386 time_t save_retrans = 0;
388 DNS_REPLY_T *r = NULL;
389 unsigned char reply[1024];
393 old_options = _res.options;
394 _res.options |= RES_DEBUG;
395 sm_dprintf("dns_lookup(%s, %d, %s)\n", domain,
396 rr_class, dns_type_to_string(rr_type));
400 save_retrans = _res.retrans;
401 _res.retrans = retrans;
405 save_retry = _res.retry;
410 len = res_search(domain, rr_class, rr_type, reply, sizeof reply);
413 _res.options = old_options;
414 sm_dprintf("dns_lookup(%s, %d, %s) --> %d\n",
415 domain, rr_class, dns_type_to_string(rr_type), len);
418 r = parse_dns_reply(reply, len);
420 _res.retrans = save_retrans;
422 _res.retry = save_retry;
428 dns_lookup(domain, type_name, retrans, retry)
430 const char *type_name;
436 type = dns_string_to_type(type_name);
440 sm_dprintf("dns_lookup: unknown resource type: `%s'\n",
444 return dns_lookup_int(domain, C_IN, type, retrans, retry);
447 # endif /* NAMED_BIND */