server: Log unable to figure out pcap vs pcapng

Change-Id: I110456f142cab88ba9d51409b66d66cf093adb9f
---
M src/osmo_server_network.c
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/osmo_server_network.c b/src/osmo_server_network.c
index 66d0894..a6db562 100644
--- a/src/osmo_server_network.c
+++ b/src/osmo_server_network.c
@@ -28,6 +28,7 @@
 #include <osmocom/core/socket.h>
 #include <osmocom/core/talloc.h>
 #include <osmocom/core/rate_ctr.h>
+#include <osmocom/core/utils.h>
 
 #include <arpa/inet.h>
 #include <sys/socket.h>
@@ -124,8 +125,11 @@
 	int rc;
 
 	rc = osmo_pcap_file_discover_fmt(data->data, data->len, &conn->file_fmt);
-	if (rc < 0)
+	if (rc < 0) {
+		LOGP(DSERVER, LOGL_ERROR, "Unable to figure out pcap vs pcapng file format (len=%u): %s\n",
+		     data->len, osmo_hexdump(data->data, OSMO_MIN(data->len, 32)));
 		return rc;
+	}
 
 	if (conn->file_fmt == OSMO_PCAP_FMT_PCAPNG) {
 		rc = osmo_pcapng_file_is_swapped(data->data, data->len);

