[PATCH v2 15/42] gresolv: Add GError for hostname lookup

Add a GError for the hostname lookup call to indicate the error as the
function should return either 0 in case of error or the source id. This
fixes the wrong returns when error happens and makes it possible to
check the error. The error message is propagated from add_query() and a
generic G_RESOLV_ERROR_ADD_QUERY error is reported as the GError code.
---
 gweb/gresolv.c      | 40 +++++++++++++++++++++++++++++++++++-----
 gweb/gresolv.h      |  8 +++++++-
 gweb/gweb.c         |  2 +-
 plugins/vpn.c       |  2 +-
 src/dnsproxy.c      |  4 ++--
 src/timeserver.c    |  2 +-
 src/wpad.c          |  4 ++--
 tools/resolv-test.c |  2 +-
 tools/wpad-test.c   |  5 +++--
 vpn/vpn-provider.c  |  2 +-
 10 files changed, 54 insertions(+), 17 deletions(-)

diff --git a/gweb/gresolv.c b/gweb/gresolv.c
index 8101d718..e1d23f8f 100644
--- a/gweb/gresolv.c
+++ b/gweb/gresolv.c
@@ -40,6 +40,9 @@
 
 #include "gresolv.h"
 
+#define G_RESOLV_ERROR g_resolv_error_quark ()
+G_DEFINE_QUARK (g-resolv-error-quark, g_resolv_error)
+
 struct sort_result {
 	int precedence;
 	int src_scope;
@@ -116,6 +119,7 @@ struct _GResolv {
 
 	GResolvDebugFunc debug_func;
 	gpointer debug_data;
+	int err;
 };
 
 #define debug(resolv, format, arg...)				\
@@ -1014,9 +1018,11 @@ static gint add_query(struct resolv_lookup *lookup, const char *hostname, int ty
 }
 
 guint g_resolv_lookup_hostname(GResolv *resolv, const char *hostname,
-				GResolvResultFunc func, gpointer user_data)
+				GResolvResultFunc func, gpointer user_data,
+				GError **error)
 {
 	struct resolv_lookup *lookup;
+	gint err;
 
 	if (!resolv)
 		return 0;
@@ -1058,14 +1064,23 @@ guint g_resolv_lookup_hostname(GResolv *resolv, const char *hostname,
 	lookup->id = resolv->next_lookup_id++;
 
 	if (resolv->result_family != AF_INET6) {
-		if (add_query(lookup, hostname, ns_t_a)) {
+		err = add_query(lookup, hostname, ns_t_a);
+		if (err) {
 			g_free(lookup);
-			return -EIO;
+
+			g_set_error(error,
+					G_RESOLV_ERROR,
+					G_RESOLV_ERROR_ADD_QUERY,
+					"Failed to add query: %s",
+					g_strerror(-err));
+
+			return 0;
 		}
 	}
 
 	if (resolv->result_family != AF_INET) {
-		if (add_query(lookup, hostname, ns_t_aaaa)) {
+		err = add_query(lookup, hostname, ns_t_aaaa);
+		if (err) {
 			if (resolv->result_family != AF_INET6) {
 				g_queue_remove(resolv->query_queue,
 						lookup->ipv4_query);
@@ -1073,7 +1088,14 @@ guint g_resolv_lookup_hostname(GResolv *resolv, const char *hostname,
 			}
 
 			g_free(lookup);
-			return -EIO;
+
+			g_set_error(error,
+					G_RESOLV_ERROR,
+					G_RESOLV_ERROR_ADD_QUERY,
+					"Failed to add query: %s",
+					g_strerror(-err));
+
+			return 0;
 		}
 	}
 
@@ -1119,3 +1141,11 @@ bool g_resolv_set_address_family(GResolv *resolv, int family)
 
 	return true;
 }
+
+int g_resolv_get_error(GResolv *resolv)
+{
+	if (!resolv)
+		return 0;
+
+	return resolv->err;
+}
diff --git a/gweb/gresolv.h b/gweb/gresolv.h
index 5e82c168..093b9a2d 100644
--- a/gweb/gresolv.h
+++ b/gweb/gresolv.h
@@ -47,6 +47,11 @@ typedef enum {
 	G_RESOLV_RESULT_STATUS_NO_ANSWER,
 } GResolvResultStatus;
 
+typedef enum {
+	G_RESOLV_ERROR_ADD_QUERY,
+	G_RESOLV_ERROR_NO_ERROR,
+} GResolvError;
+
 typedef void (*GResolvResultFunc)(GResolvResultStatus status,
 					char **results, gpointer user_data);
 
@@ -65,7 +70,8 @@ bool g_resolv_add_nameserver(GResolv *resolv, const char *address,
 void g_resolv_flush_nameservers(GResolv *resolv);
 
 guint g_resolv_lookup_hostname(GResolv *resolv, const char *hostname,
-				GResolvResultFunc func, gpointer user_data);
+				GResolvResultFunc func, gpointer user_data,
+				GError **error);
 
 bool g_resolv_cancel_lookup(GResolv *resolv, guint id);
 
diff --git a/gweb/gweb.c b/gweb/gweb.c
index 4dbbb4c8..4aa4416a 100644
--- a/gweb/gweb.c
+++ b/gweb/gweb.c
@@ -2673,7 +2673,7 @@ static guint do_request(GWeb *web, const char *url,
 		session->address_action = g_idle_add(already_resolved, session);
 	} else {
 		session->resolv_action = g_resolv_lookup_hostname(web->resolv,
-					host, resolv_result, session);
+					host, resolv_result, session, NULL);
 		if (session->resolv_action <= 0) {
 			free_session(session);
 			/*
diff --git a/plugins/vpn.c b/plugins/vpn.c
index d683c67d..c0739fc1 100644
--- a/plugins/vpn.c
+++ b/plugins/vpn.c
@@ -243,7 +243,7 @@ static void resolv_host_addr(struct connection_data *data)
 	DBG("Trying to resolv %s", data->host);
 
 	data->resolv_id = g_resolv_lookup_hostname(data->resolv, data->host,
-						resolv_result, data);
+						resolv_result, data, NULL);
 }
 
 static void free_config_cb_data(struct config_create_data *cb_data)
diff --git a/src/dnsproxy.c b/src/dnsproxy.c
index 1dd2f7f5..71a01f6d 100644
--- a/src/dnsproxy.c
+++ b/src/dnsproxy.c
@@ -400,14 +400,14 @@ static void refresh_dns_entry(struct cache_entry *entry, char *name)
 	if (!entry->ipv4) {
 		debug("Refreshing A record for %s", name);
 		g_resolv_lookup_hostname(ipv4_resolve, name,
-					dummy_resolve_func, NULL);
+					dummy_resolve_func, NULL, NULL);
 		age = 4;
 	}
 
 	if (!entry->ipv6) {
 		debug("Refreshing AAAA record for %s", name);
 		g_resolv_lookup_hostname(ipv6_resolve, name,
-					dummy_resolve_func, NULL);
+					dummy_resolve_func, NULL, NULL);
 		age = 4;
 	}
 
diff --git a/src/timeserver.c b/src/timeserver.c
index d364f728..8f077307 100644
--- a/src/timeserver.c
+++ b/src/timeserver.c
@@ -204,7 +204,7 @@ static void sync_next(void)
 
 		DBG("Resolving timeserver %s", ts_current);
 		resolv_id = g_resolv_lookup_hostname(resolv, ts_current,
-						resolv_result, NULL);
+						resolv_result, NULL, NULL);
 		return;
 	}
 
diff --git a/src/wpad.c b/src/wpad.c
index e1886d2b..f3bc6282 100644
--- a/src/wpad.c
+++ b/src/wpad.c
@@ -111,7 +111,7 @@ static void wpad_result(GResolvResultStatus status,
 	DBG("hostname %s", wpad->hostname);
 
 	g_resolv_lookup_hostname(wpad->resolv, wpad->hostname,
-							wpad_result, wpad);
+						wpad_result, wpad, NULL);
 
 	return;
 
@@ -176,7 +176,7 @@ int __connman_wpad_start(struct connman_service *service)
 	wpad->service = connman_service_ref(service);
 
 	g_resolv_lookup_hostname(wpad->resolv, wpad->hostname,
-							wpad_result, wpad);
+						wpad_result, wpad, NULL);
 
 	g_hash_table_replace(wpad_list, GINT_TO_POINTER(index), wpad);
 
diff --git a/tools/resolv-test.c b/tools/resolv-test.c
index 1aad2841..acf4f0bd 100644
--- a/tools/resolv-test.c
+++ b/tools/resolv-test.c
@@ -146,7 +146,7 @@ int main(int argc, char *argv[])
 	timer = g_timer_new();
 
 	if (g_resolv_lookup_hostname(resolv, argv[1],
-					resolv_result, NULL) == 0) {
+					resolv_result, NULL, NULL) == 0) {
 		printf("failed to start lookup\n");
 		return 1;
 	}
diff --git a/tools/wpad-test.c b/tools/wpad-test.c
index 2ecbcdae..518d42ea 100644
--- a/tools/wpad-test.c
+++ b/tools/wpad-test.c
@@ -75,7 +75,7 @@ static void resolv_result(GResolvResultStatus status,
 
 	str = g_strdup_printf("wpad.%s", ptr + 1);
 
-	g_resolv_lookup_hostname(resolv, str, resolv_result, str);
+	g_resolv_lookup_hostname(resolv, str, resolv_result, str, NULL);
 
 	g_free(hostname);
 
@@ -118,7 +118,8 @@ static void start_wpad(const char *search)
 
 	hostname = g_strdup_printf("wpad.%s", domainname);
 
-	g_resolv_lookup_hostname(resolv, hostname, resolv_result, hostname);
+	g_resolv_lookup_hostname(resolv, hostname, resolv_result, hostname,
+					NULL);
 
 	return;
 
diff --git a/vpn/vpn-provider.c b/vpn/vpn-provider.c
index b21e9e61..b79b7963 100644
--- a/vpn/vpn-provider.c
+++ b/vpn/vpn-provider.c
@@ -980,7 +980,7 @@ static void provider_resolv_host_addr(struct vpn_provider *provider)
 	vpn_provider_ref(provider);
 
 	g_resolv_lookup_hostname(provider->resolv, provider->host,
-				resolv_result, provider);
+				resolv_result, provider, NULL);
 }
 
 void __vpn_provider_append_properties(struct vpn_provider *provider,
-- 
2.39.5