Skip logging for DNSSEC responses [BZ 14841]

DNSSEC defines a number of response types that one me expect when the
DO bit is set.  We don't process any of them, but since we do allow
setting the DO bit, skip them without logging an error since it is
only a nuisance.

Tested on x86_64.

	[BZ #14841]
	* resolv/gethnamaddr.c (getanswer): Skip logging if
	RES_USE_DNSSEC is set.
	* resolv/nss_dns/dns-host.c (getanswer_r): Likewise.

1 files changed, 8 insertions, 15 deletions

diff --git a/resolv/nss_dns/dns-host.c b/resolv/nss_dns/dns-host.c
index f715ab0b3f..b16b0ddf11 100644
--- a/resolv/nss_dns/dns-host.c
+++ b/resolv/nss_dns/dns-host.c
@@ -820,26 +820,19 @@ getanswer_r (const querybuf *answer, int anslen, const char *qname, int qtype,
 	  linebuflen -= n;
 	  continue;
 	}
-      if (__builtin_expect (type == T_SIG, 0)
-	  || __builtin_expect (type == T_KEY, 0)
-	  || __builtin_expect (type == T_NXT, 0))
-	{
-	  /* We don't support DNSSEC yet.  For now, ignore the record
-	     and send a low priority message to syslog.  */
-	  syslog (LOG_DEBUG | LOG_AUTH,
-	       "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"",
-		  qname, p_class (C_IN), p_type(qtype), p_type (type));
-	  cp += n;
-	  continue;
-	}
 
       if (type == T_A && qtype == T_AAAA && map)
 	have_to_map = 1;
       else if (__glibc_unlikely (type != qtype))
 	{
-	  syslog (LOG_NOTICE | LOG_AUTH,
-	       "gethostby*.getanswer: asked for \"%s %s %s\", got type \"%s\"",
-		  qname, p_class (C_IN), p_type (qtype), p_type (type));
+	  /* Log a low priority message if we get an unexpected record, but
+	     skip it if we are using DNSSEC since it uses many different types
+	     in responses that do not match QTYPE.  */
+	  if ((_res.options & RES_USE_DNSSEC) == 0)
+	    syslog (LOG_NOTICE | LOG_AUTH,
+		    "gethostby*.getanswer: asked for \"%s %s %s\", "
+		    "got type \"%s\"",
+		    qname, p_class (C_IN), p_type (qtype), p_type (type));
 	  cp += n;
 	  continue;			/* XXX - had_error++ ? */
 	}