use res_ninit to guess dns names

.cproject

@@ -78,6 +78,11 @@
 							</tool>
 						</toolChain>
 					</folderInfo>
+					<sourceEntries>
+						<entry flags="VALUE_WORKSPACE_PATH" kind="sourcePath" name="include/belle-sip"/>
+						<entry flags="VALUE_WORKSPACE_PATH" kind="sourcePath" name="src"/>
+						<entry flags="VALUE_WORKSPACE_PATH" kind="sourcePath" name="tester"/>
+					</sourceEntries>
 				</configuration>
 			</storageModule>
 			<storageModule moduleId="org.eclipse.cdt.core.externalSettings"/>
@@ -114,6 +119,7 @@
 			</target>
 		</buildTargets>
 	</storageModule>
+	<storageModule moduleId="org.eclipse.cdt.core.LanguageSettingsProviders"/>
 	<storageModule moduleId="scannerConfiguration">
 		<autodiscovery enabled="true" problemReportingEnabled="true" selectedProfileId=""/>
 		<profile id="org.eclipse.cdt.make.core.GCCStandardMakePerProjectProfile">
@@ -199,7 +205,7 @@
 				</scannerInfoProvider>
 			</profile>
 		</scannerConfigBuildInfo>
-		<scannerConfigBuildInfo instanceId="cdt.managedbuild.toolchain.gnu.macosx.base.557244179;cdt.managedbuild.toolchain.gnu.macosx.base.557244179.779699347;cdt.managedbuild.tool.gnu.c.compiler.macosx.base.1327025999;cdt.managedbuild.tool.gnu.c.compiler.input.1517483722">
+		<scannerConfigBuildInfo instanceId="cdt.managedbuild.toolchain.gnu.macosx.base.557244179.959032290;cdt.managedbuild.toolchain.gnu.macosx.base.557244179.959032290.;cdt.managedbuild.tool.gnu.c.compiler.macosx.base.3940526;cdt.managedbuild.tool.gnu.c.compiler.input.2089521215">
 			<autodiscovery enabled="true" problemReportingEnabled="true" selectedProfileId="org.eclipse.cdt.managedbuilder.core.GCCManagedMakePerProjectProfileC"/>
 			<profile id="org.eclipse.cdt.make.core.GCCStandardMakePerProjectProfile">
 				<buildOutputProvider>
@@ -242,7 +248,7 @@
 				</scannerInfoProvider>
 			</profile>
 		</scannerConfigBuildInfo>
-		<scannerConfigBuildInfo instanceId="cdt.managedbuild.toolchain.gnu.macosx.base.557244179.959032290;cdt.managedbuild.toolchain.gnu.macosx.base.557244179.959032290.;cdt.managedbuild.tool.gnu.c.compiler.macosx.base.3940526;cdt.managedbuild.tool.gnu.c.compiler.input.2089521215">
+		<scannerConfigBuildInfo instanceId="cdt.managedbuild.toolchain.gnu.macosx.base.557244179;cdt.managedbuild.toolchain.gnu.macosx.base.557244179.779699347;cdt.managedbuild.tool.gnu.c.compiler.macosx.base.1327025999;cdt.managedbuild.tool.gnu.c.compiler.input.1517483722">
 			<autodiscovery enabled="true" problemReportingEnabled="true" selectedProfileId="org.eclipse.cdt.managedbuilder.core.GCCManagedMakePerProjectProfileC"/>
 			<profile id="org.eclipse.cdt.make.core.GCCStandardMakePerProjectProfile">
 				<buildOutputProvider>
@@ -286,5 +292,4 @@
 			</profile>
 		</scannerConfigBuildInfo>
 	</storageModule>
-	<storageModule moduleId="org.eclipse.cdt.core.LanguageSettingsProviders"/>
 </cproject>

configure.ac

@@ -71,6 +71,11 @@ CPPFLAGS_save=$CPPFLAGS
 CPPFLAGS="$CPPFLAGS $ANTLR_CFLAGS"
 AC_CHECK_HEADERS([antlr3.h], [found_antlr3=yes])
 AC_CHECK_DECL([antlr3StringStreamNew], [found_antlr3=yes], [found_antlr3=no],[#include <antlr3.h>])
+AC_CHECK_DECL([res_ninit]
+				,[AC_DEFINE(HAVE_RESINIT,1,[Defined when res_ninit api is available])  LIBS="$LIBS -lresolv"]
+				,[foo=bar]
+				,[#include <resolv.h>])
+				
 CPPFLAGS=$CPPFLAGS_save
 
 if test "$found_antlr3" != "yes" ; then

src/belle_sip_resolver.c

@@ -25,7 +25,7 @@
 
 
 static struct dns_resolv_conf *resconf(belle_sip_resolver_context_t *ctx) {
-#ifndef _WIN32
+#if !_WIN32 && !HAVE_RESINIT
 	const char *path;
 #endif
 	int error;
@@ -43,12 +43,16 @@ static struct dns_resolv_conf *resconf(belle_sip_resolver_context_t *ctx) {
 	if (error) {
 		belle_sip_error("%s dns_resconf_loadwin error", __FUNCTION__);
 	}
-#else
-#ifdef ANDROID
+#elif ANDROID
 	error = dns_resconf_loadandroid(ctx->resconf);
 	if (error) {
 		belle_sip_error("%s dns_resconf_loadandroid error", __FUNCTION__);
 	}
+#elif HAVE_RESINIT
+	error = dns_resconf_loadfromresolv(ctx->resconf);
+	if (error) {
+		belle_sip_error("%s dns_resconf_loadfromresolv error", __FUNCTION__);
+	}
 #else
 	path = "/etc/resolv.conf";
 	error = dns_resconf_loadpath(ctx->resconf, path);
@@ -63,7 +67,7 @@ static struct dns_resolv_conf *resconf(belle_sip_resolver_context_t *ctx) {
 		belle_sip_message("%s dns_nssconf_loadpath error [%s]: %s", __FUNCTION__, path, dns_strerror(error));
 	}
 #endif
-#endif
+
 
 	return ctx->resconf;
 }

src/dns.c

@@ -104,6 +104,9 @@
 
 #include "dns.h"
 
+#ifdef HAVE_RESINIT
+#include <resolv.h>
+#endif
 
 /*
  * C O M P I L E R  A N N O T A T I O N S
@@ -4367,6 +4370,23 @@ int dns_resconf_loadandroid(struct dns_resolv_conf *resconf) {
 } /* dns_resconf_loadandroid */
 #endif
 
+#ifdef HAVE_RESINIT
+int dns_resconf_loadfromresolv(struct dns_resolv_conf *resconf) {
+	struct __res_state res;
+	union res_sockaddr_union addresses[3];
+	int i,error;
+
+	if ((error = res_ninit(&res))) {
+		return error;
+	}
+
+    for (i = 0; i < res_getservers(&res,addresses,res.nscount) && i<3 /*only 3 element*/; i++ ) {
+    	memcpy(&resconf->nameserver[i],&addresses[i],sizeof(union res_sockaddr_union));
+    }
+    res_ndestroy(&res);
+    return i>0?0:-1;
+}
+#endif /*HAVE_RESINIT*/
 
 struct dns_anyconf {
 	char *token[16];

src/dns.h

@@ -25,7 +25,9 @@
  */
 #ifndef DNS_H
 #define DNS_H
-
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
 #include <stddef.h>		/* size_t offsetof() */
 #include <stdio.h>		/* FILE */
 
@@ -911,7 +913,9 @@ int dns_resconf_loadpath(struct dns_resolv_conf *, const char *);
 #ifdef _WIN32
 int dns_resconf_loadwin(struct dns_resolv_conf *);
 #endif
-
+#ifdef HAVE_RESINIT
+int dns_resconf_loadfromresolv(struct dns_resolv_conf *resconf);
+#endif /*HAVE_RESINIT*/
 int dns_nssconf_loadfile(struct dns_resolv_conf *, FILE *);
 
 int dns_nssconf_loadpath(struct dns_resolv_conf *, const char *);