[PATCH 2/5] batctl: tpmeter: abort result wait on receive errors

tp_recv_result() loops on nl_recvmsgs() until the tp_meter result
notification arrives, but never checks its return value. When the receive
fails (receive queue overrun and drops notification, socket failed
completely, ...), the loop just calls nl_recvmsgs() again and blocks
forever in recvmsg() waiting for a message that will never arrive.

Leave the receive loop on errors instead; the existing checks below then
report the failure to the caller.

Fixes: f109b3473f86 ("batctl: introduce throughput meter support")
Signed-off-by: Sven Eckelmann <[email protected]>
---
 throughputmeter.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/throughputmeter.c b/throughputmeter.c
index 10f4f24..fd4165c 100644
--- a/throughputmeter.c
+++ b/throughputmeter.c
@@ -198,6 +198,7 @@ static int tp_recv_result(struct nl_sock *sock, struct tp_result *result)
 {
 	struct nl_cb *cb;
 	int err = 0;
+	int ret;
 
 	cb = nl_cb_alloc(NL_CB_DEFAULT);
 	nl_cb_set(cb, NL_CB_SEQ_CHECK, NL_CB_CUSTOM, no_seq_check, NULL);
@@ -205,8 +206,11 @@ static int tp_recv_result(struct nl_sock *sock, struct tp_result *result)
 		  result);
 	nl_cb_err(cb, NL_CB_CUSTOM, tpmeter_nl_print_error, result);
 
-	while (result->error == 0 && !result->found)
-		nl_recvmsgs(sock, cb);
+	while (result->error == 0 && !result->found) {
+		ret = nl_recvmsgs(sock, cb);
+		if (ret < 0)
+			break;
+	}
 
 	nl_cb_put(cb);
 

-- 
2.47.3