Update the resolver in libc to BIND9's one.

Since, res_sendsigned(3) and the friends use MD5 functions, it is
hard to include them without having MD5 functions in libc.  So,
res_sendsigned(3) is not merged into libc.

Since, res_update(3) in BIND9 is not binary compatible with our
res_update(3), res_update(3) is leaved as is, except some
necessary modifications.
The res_update(3) and the friends are not essential part of the
resolver.  They are not defined in resolv.h but defined in
res_update.h separately in BIND9.  Further, they are not called from
our tree.  So, I hide them from our resolv.h, but leave them only
for binary backward compatibility (perhaps, no one calls them).

Since, struct __res_state_ext is not exposed in BIND9, I hide it
from our resolv.h.  And, global variable _res_ext is removed.  It
breaks binary backward compatibility.  But, since it is not used from
outside of our libc, I think it is safe.

Reviewed by:	arch@ (no objection)

1 files changed, 3 insertions, 1 deletions

diff --git a/lib/libc/net/res_update.c b/lib/libc/net/res_update.c
index fda6f77..d78ca70 100644
--- a/lib/libc/net/res_update.c
+++ b/lib/libc/net/res_update.c
@@ -36,6 +36,8 @@ __FBSDID("$FreeBSD$");
 #include <stdlib.h>
 #include <string.h>
 
+#include "res_update.h"
+
 /*
  * Separate a linked list of records into groups so that all records
  * in a group will belong to a single zone on the nameserver.
@@ -85,7 +87,7 @@ res_update(ns_updrec *rrecp_in) {
 	u_int32_t ttl;
 
 	if ((_res.options & RES_INIT) == 0 && res_init() == -1) {
-		h_errno = NETDB_INTERNAL;
+		RES_SET_H_ERRNO(&_res, NETDB_INTERNAL);
 		return (-1);
 	}