From 1a8fd4ba87d670b759fc51bb1dc37808e5213be4 Mon Sep 17 00:00:00 2001
From: Jan-Philipp Litza <janphilipp@litza.de>
Date: Sun, 30 Apr 2017 11:41:16 +0200
Subject: [PATCH] respondd-module-airtime: Give more helpful error messages

---
 net/respondd-module-airtime/src/netlink.c | 43 +++++++++++++++++------
 1 file changed, 33 insertions(+), 10 deletions(-)

diff --git a/net/respondd-module-airtime/src/netlink.c b/net/respondd-module-airtime/src/netlink.c
index 8b96711..2030193 100644
--- a/net/respondd-module-airtime/src/netlink.c
+++ b/net/respondd-module-airtime/src/netlink.c
@@ -1,3 +1,5 @@
+#include <inttypes.h>
+
 #include <linux/nl80211.h>
 #include <netlink/genl/genl.h>
 #include <netlink/genl/ctrl.h>
@@ -6,28 +8,49 @@
 
 bool nl_send_dump(nl_recvmsg_msg_cb_t cb, void *cb_arg, int cmd, uint32_t cmd_arg) {
 	bool ok = false;
+	int ret;
 	int ctrl;
 	struct nl_sock *sk = NULL;
 	struct nl_msg *msg = NULL;
 
 
-#define CHECK(x) { if (!(x)) { fprintf(stderr, "%s: error on line %d\n", __FILE__, __LINE__); goto out; } }
+#define ERR(...) { fprintf(stderr, "respondd-module-airtime: " __VA_ARGS__); goto out; }
 
-	CHECK(sk = nl_socket_alloc());
-	CHECK(genl_connect(sk) >= 0);
+	sk = nl_socket_alloc();
+	if (!sk)
+		ERR("nl_socket_alloc() failed\n");
 
-	CHECK(ctrl = genl_ctrl_resolve(sk, NL80211_GENL_NAME));
-	CHECK(nl_socket_modify_cb(sk, NL_CB_VALID, NL_CB_CUSTOM, cb, cb_arg) == 0);
-	CHECK(msg = nlmsg_alloc());
-	CHECK(genlmsg_put(msg, 0, 0, ctrl, 0, NLM_F_DUMP, cmd, 0));
+	ret = genl_connect(sk);
+	if (ret < 0)
+		ERR("genl_connect() returned %d\n", ret);
+
+	ctrl = genl_ctrl_resolve(sk, NL80211_GENL_NAME);
+	if (ctrl < 0)
+		ERR("genl_ctrl_resolve() returned %d\n", ctrl);
+
+	ret = nl_socket_modify_cb(sk, NL_CB_VALID, NL_CB_CUSTOM, cb, cb_arg);
+	if (ret != 0)
+		ERR("nl_socket_modify_cb() returned %d\n", ret);
+
+	msg = nlmsg_alloc();
+	if (!msg)
+		ERR("nlmsg_alloc() failed\n");
+
+	if (!genlmsg_put(msg, 0, 0, ctrl, 0, NLM_F_DUMP, cmd, 0))
+		ERR("genlmsg_put() failed while putting cmd %d\n", ret, cmd);
 
 	if (cmd_arg != 0)
 		NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, cmd_arg);
 
-	CHECK(nl_send_auto_complete(sk, msg) >= 0);
-	CHECK(nl_recvmsgs_default(sk) >= 0);
+	ret = nl_send_auto_complete(sk, msg);
+	if (ret < 0)
+		ERR("nl_send_auto() returned %d while sending cmd %d with cmd_arg=%"PRIu32"\n", ret, cmd, cmd_arg);
 
-#undef CHECK
+	ret = nl_recvmsgs_default(sk);
+	if (ret < 0)
+		ERR("nl_recv_msgs_default() returned %d while receiving cmd %d with cmd_arg=%"PRIu32"\n", ret, cmd, cmd_arg);
+
+#undef ERR
 
 	ok = true;