path: root/src/network/res_query.c
diff options
authorRich Felker <>2014-06-02 02:13:57 -0400
committerRich Felker <>2014-06-02 02:13:57 -0400
commit8312f7f60f9dfe88118163d38b8282abf04aac2f (patch)
tree0dcbcbd3f9e6b3362a920707895624bdc3adb1f5 /src/network/res_query.c
parent1871f583f419f58bbcd921cda41c991994672c8a (diff)
implement new dns backend, res_send and other legacy resolver functions
this is the second phase of the "resolver overhaul" project. the key additions in this commit are the __res_msend and __res_mkquery functions, which have been factored so as to provide a backend for both the legacy res_* functions and the standard getaddrinfo and getnameinfo functions. the latter however are still using the old backend code; there is code duplication which still needs to be removed, and this will be the next phase of the resolver overhaul. __res_msend is derived from the old __dns_doqueries function, but generalized to send arbitrary caller-provided packets in parallel rather than producing the parallel queries itself. this allows it to be used (completely trivially) as a backend for res_send. the factored-out query generation code, with slightly more generality, is now part of __res_mkquery.
Diffstat (limited to 'src/network/res_query.c')
1 files changed, 10 insertions, 18 deletions
diff --git a/src/network/res_query.c b/src/network/res_query.c
index 3847da37..2b4e4bb1 100644
--- a/src/network/res_query.c
+++ b/src/network/res_query.c
@@ -1,25 +1,17 @@
-#define _GNU_SOURCE
#include <resolv.h>
#include <netdb.h>
-#include "__dns.h"
#include "libc.h"
-int res_query(const char *name, int class, int type, unsigned char *dest, int len)
+int __res_mkquery(int, const char *, int, int, const unsigned char *, int, const unsigned char*, unsigned char *, int);
+int __res_send(const unsigned char *, int, unsigned char *, int);
+int __res_query(const char *name, int class, int type, unsigned char *dest, int len)
- if (class != 1 || len < 512)
- return -1;
- switch(__dns_doqueries(dest, name, &type, 1)) {
- case EAI_NONAME:
- h_errno = HOST_NOT_FOUND;
- return -1;
- case EAI_AGAIN:
- h_errno = TRY_AGAIN;
- return -1;
- case EAI_FAIL:
- h_errno = NO_RECOVERY;
- return -1;
- }
- return 512;
+ unsigned char q[280];
+ int ql = __res_mkquery(0, name, class, type, 0, 0, 0, q, sizeof q);
+ if (ql < 0) return ql;
+ return __res_send(q, ql, dest, len);
-weak_alias(res_query, res_search);
+weak_alias(__res_query, res_query);
+weak_alias(__res_query, res_search);