Author: mmichelson
Date: Mon Apr 6 15:24:31 2015
New Revision: 434152
URL: http://svnview.digium.com/svn/asterisk?view=rev&rev=434152
Log:
Place record location code within the DNS core.
This eliminates some more duplication.
Modified:
team/group/dns/include/asterisk/dns_internal.h
team/group/dns/main/dns_core.c
team/group/dns/main/dns_naptr.c
team/group/dns/main/dns_srv.c
Modified: team/group/dns/include/asterisk/dns_internal.h
URL:
http://svnview.digium.com/svn/asterisk/team/group/dns/include/asterisk/dns_internal.h?view=diff&rev=434152&r1=434151&r2=434152
==============================================================================
--- team/group/dns/include/asterisk/dns_internal.h (original)
+++ team/group/dns/include/asterisk/dns_internal.h Mon Apr 6 15:24:31 2015
@@ -204,3 +204,18 @@
*/
void dns_srv_sort(struct ast_dns_result *result);
+/*!
+ * \brief Find the location of a DNS record within the entire DNS answer
+ *
+ * The DNS record that has been returned by the resolver may be a copy of the
record that was
+ * found in the complete DNS response. If so, then some DNS record types
(specifically those that
+ * parse domains) will need to locate the DNS record within the complete DNS
response. This is so
+ * that if the domain contains pointers to other sections of the DNS response,
then the referenced
+ * domains may be located.
+ *
+ * \param record The DNS record returned by a resolver implementation
+ * \param record_size The size of the DNS record in bytes
+ * \param response The complete DNS answer
+ * \param response_size The size of the complete DNS response
+ */
+char *dns_find_record(const char *record, size_t record_size, const char
*response, size_t response_size);
Modified: team/group/dns/main/dns_core.c
URL:
http://svnview.digium.com/svn/asterisk/team/group/dns/main/dns_core.c?view=diff&rev=434152&r1=434151&r2=434152
==============================================================================
--- team/group/dns/main/dns_core.c (original)
+++ team/group/dns/main/dns_core.c Mon Apr 6 15:24:31 2015
@@ -610,3 +610,24 @@
ast_verb(2, "Unregistered DNS resolver '%s'\n", resolver->name);
}
+
+char *dns_find_record(const char *record, size_t record_size, const char
*response, size_t response_size)
+{
+ size_t remaining_size = response_size;
+ const char *search_base = response;
+ char *record_offset;
+
+ while (1) {
+ record_offset = memchr(search_base, record[0], remaining_size);
+
+ ast_assert(record_offset != NULL);
+ ast_assert(search_base + remaining_size - record_offset >=
record_size);
+
+ if (!memcmp(record_offset, record, record_size)) {
+ return record_offset;
+ }
+
+ remaining_size -= record_offset - search_base;
+ search_base = record_offset + 1;
+ }
+}
Modified: team/group/dns/main/dns_naptr.c
URL:
http://svnview.digium.com/svn/asterisk/team/group/dns/main/dns_naptr.c?view=diff&rev=434152&r1=434151&r2=434152
==============================================================================
--- team/group/dns/main/dns_naptr.c (original)
+++ team/group/dns/main/dns_naptr.c Mon Apr 6 15:24:31 2015
@@ -392,54 +392,10 @@
char *regexp;
char replacement[256] = "";
int replacement_size;
- char *naptr_offset;
- char *naptr_search_base = (char *)query->result->answer;
- size_t remaining_size = query->result->answer_size;
- char *end_of_record;
+ const char *end_of_record;
enum flags_result flags_res;
- /*
- * This is bordering on the hackiest thing I've ever written.
- * Part of parsing a NAPTR record is to parse a potential replacement
- * domain name. Decoding this domain name requires the use of the
- * dn_expand() function. This function requires that the domain you
- * pass in be a pointer to within the full DNS answer. Unfortunately,
- * libunbound gives its RRs back as copies of data from the DNS answer
- * instead of pointers to within the DNS answer. This means that in
order
- * to be able to parse the domain name correctly, I need to find the
- * current NAPTR record inside the DNS answer and operate on it. This
- * loop is designed to find the current NAPTR record within the full
- * DNS answer and set the "ptr" variable to the beginning of the
- * NAPTR RDATA
- */
- while (1) {
- naptr_offset = memchr(naptr_search_base, data[0],
remaining_size);
-
- /* Since the NAPTR record we have been given came from the DNS
answer,
- * we should never run into a situation where we can't find
ourself
- * in the answer
- */
- ast_assert(naptr_offset != NULL);
- ast_assert(naptr_search_base + remaining_size - naptr_offset >=
size);
-
- /* ... but just to be on the safe side, let's be sure we can
break
- * out if the assertion doesn't hold
- */
- if (!naptr_offset || naptr_search_base + remaining_size -
naptr_offset < size) {
- ast_log(LOG_ERROR, "Failed to locate NAPTR record
within DNS result\n");
- return NULL;
- }
-
- if (!memcmp(naptr_offset, data, size)) {
- /* BAM! FOUND IT! */
- ptr = naptr_offset;
- break;
- }
- /* Data didn't match us, so keep looking */
- remaining_size -= naptr_offset - naptr_search_base;
- naptr_search_base = naptr_offset + 1;
- }
-
+ ptr = dns_find_record(data, size, query->result->answer,
query->result->answer_size);
ast_assert(ptr != NULL);
end_of_record = ptr + size;
@@ -472,6 +428,7 @@
if (PAST_END_OF_RECORD) {
return NULL;
}
+
flags = ptr;
ptr += flags_size;
if (PAST_END_OF_RECORD) {
Modified: team/group/dns/main/dns_srv.c
URL:
http://svnview.digium.com/svn/asterisk/team/group/dns/main/dns_srv.c?view=diff&rev=434152&r1=434151&r2=434152
==============================================================================
--- team/group/dns/main/dns_srv.c (original)
+++ team/group/dns/main/dns_srv.c Mon Apr 6 15:24:31 2015
@@ -47,29 +47,12 @@
uint16_t weight;
uint16_t port;
const char *ptr;
- char *srv_offset;
- char *srv_search_base = (char *)query->result->answer;
- size_t remaining_size = query->result->answer_size;
const char *end_of_record;
struct ast_dns_srv_record *srv;
int host_size;
char host[NI_MAXHOST] = "";
- while (1) {
- srv_offset = memchr(srv_search_base, data[0], remaining_size);
-
- ast_assert(srv_offset != NULL);
- ast_assert(srv_search_base + remaining_size - srv_offset >=
size);
-
- if (!memcmp(srv_offset, data, size)) {
- ptr = srv_offset;
- break;
- }
-
- remaining_size -= srv_offset - srv_search_base;
- srv_search_base = srv_offset + 1;
- }
-
+ ptr = dns_find_record(data, size, query->result->answer,
query->result->answer_size);
ast_assert(ptr != NULL);
end_of_record = ptr + size;
--
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