From 2212c1420c92a33b0e0bd9a34938c9814a56c0f7 Mon Sep 17 00:00:00 2001
From: Andreas Schwab <schwab@suse.de>
Date: Thu, 19 Feb 2015 15:52:08 +0100
Subject: Simplify handling of nameserver configuration in resolver

Remove use of ext.nsmap member of struct __res_state and always use
an identity mapping betwen the nsaddr_list array and the ext.nsaddrs
array.  The fact that a nameserver has an IPv6 address is signalled by
setting nsaddr_list[].sin_family to zero.
---
 resolv/res_init.c | 47 ++++++++++++++---------------------------------
 1 file changed, 14 insertions(+), 33 deletions(-)

(limited to 'resolv/res_init.c')

diff --git a/resolv/res_init.c b/resolv/res_init.c
index 553ba12a5a..66561ffac2 100644
--- a/resolv/res_init.c
+++ b/resolv/res_init.c
@@ -153,10 +153,8 @@ __res_vinit(res_state statp, int preinit) {
 	char *cp, **pp;
 	int n;
 	char buf[BUFSIZ];
-	int nserv = 0;    /* number of IPv4 nameservers read from file */
-#ifdef _LIBC
-	int nservall = 0; /* number of (IPv4 + IPV6) nameservers read from file */
-#endif
+	int nserv = 0;    /* number of nameservers read from file */
+	int have_serv6 = 0;
 	int haveenv = 0;
 	int havesearch = 0;
 #ifdef RESOLVSORT
@@ -184,15 +182,9 @@ __res_vinit(res_state statp, int preinit) {
 	statp->_flags = 0;
 	statp->qhook = NULL;
 	statp->rhook = NULL;
-	statp->_u._ext.nsinit = 0;
 	statp->_u._ext.nscount = 0;
-#ifdef _LIBC
-	statp->_u._ext.nscount6 = 0;
-	for (n = 0; n < MAXNS; n++) {
-		statp->_u._ext.nsaddrs[n] = NULL;
-		statp->_u._ext.nsmap[n] = MAXNS;
-	}
-#endif
+	for (n = 0; n < MAXNS; n++)
+	    statp->_u._ext.nsaddrs[n] = NULL;
 
 	/* Allow user to override the local domain definition */
 	if ((cp = getenv("LOCALDOMAIN")) != NULL) {
@@ -296,11 +288,7 @@ __res_vinit(res_state statp, int preinit) {
 		    continue;
 		}
 		/* read nameservers to query */
-#ifdef _LIBC
-		if (MATCH(buf, "nameserver") && nservall < MAXNS) {
-#else
 		if (MATCH(buf, "nameserver") && nserv < MAXNS) {
-#endif
 		    struct in_addr a;
 
 		    cp = buf + sizeof("nameserver") - 1;
@@ -308,13 +296,12 @@ __res_vinit(res_state statp, int preinit) {
 			cp++;
 		    if ((*cp != '\0') && (*cp != '\n')
 			&& __inet_aton(cp, &a)) {
-			statp->nsaddr_list[nservall].sin_addr = a;
-			statp->nsaddr_list[nservall].sin_family = AF_INET;
-			statp->nsaddr_list[nservall].sin_port =
+			statp->nsaddr_list[nserv].sin_addr = a;
+			statp->nsaddr_list[nserv].sin_family = AF_INET;
+			statp->nsaddr_list[nserv].sin_port =
 				htons(NAMESERVER_PORT);
 			nserv++;
 #ifdef _LIBC
-			nservall++;
 		    } else {
 			struct in6_addr a6;
 			char *el;
@@ -356,10 +343,11 @@ __res_vinit(res_state statp, int preinit) {
 				    }
 				}
 
-				statp->_u._ext.nsaddrs[nservall] = sa6;
-				statp->_u._ext.nssocks[nservall] = -1;
-				statp->_u._ext.nsmap[nservall] = MAXNS + 1;
-				nservall++;
+				statp->nsaddr_list[nserv].sin_family = 0;
+				statp->_u._ext.nsaddrs[nserv] = sa6;
+				statp->_u._ext.nssocks[nserv] = -1;
+				have_serv6 = 1;
+				nserv++;
 			    }
 			}
 #endif
@@ -414,10 +402,9 @@ __res_vinit(res_state statp, int preinit) {
 		    continue;
 		}
 	    }
-	    statp->nscount = nservall;
+	    statp->nscount = nserv;
 #ifdef _LIBC
-	    if (nservall - nserv > 0) {
-		statp->_u._ext.nscount6 = nservall - nserv;
+	    if (have_serv6) {
 		/* We try IPv6 servers again.  */
 		statp->ipv6_unavail = false;
 	    }
@@ -606,11 +593,7 @@ __res_iclose(res_state statp, bool free_addr) {
 		statp->_vcsock = -1;
 		statp->_flags &= ~(RES_F_VC | RES_F_CONN);
 	}
-#ifdef _LIBC
-	for (ns = 0; ns < MAXNS; ns++)
-#else
 	for (ns = 0; ns < statp->_u._ext.nscount; ns++)
-#endif
 		if (statp->_u._ext.nsaddrs[ns]) {
 			if (statp->_u._ext.nssocks[ns] != -1) {
 				close_not_cancel_no_status(statp->_u._ext.nssocks[ns]);
@@ -621,8 +604,6 @@ __res_iclose(res_state statp, bool free_addr) {
 				statp->_u._ext.nsaddrs[ns] = NULL;
 			}
 		}
-	if (free_addr)
-		statp->_u._ext.nsinit = 0;
 }
 libc_hidden_def (__res_iclose)
 
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