gtphub: log: limit length of hex dumps.

The debug log prints the received/sent bytes in hex. When this data surpasses
the buffer size available for the log string (4096), the log is truncated
and lacks a newline character. Limit the amount of dumped bytes to 1000.

Sponsored-by: On-Waves ehi

openbsc/src/gprs/gtphub.c

@@ -942,9 +942,10 @@ static int gtphub_read(const struct osmo_fd *from,
 		return 0;
 	}
 
-	LOG(LOGL_DEBUG, "Received %d bytes from %s: %s\n",
+	LOG(LOGL_DEBUG, "Received %d bytes from %s: %s%s\n",
 	    (int)received, osmo_sockaddr_to_str(from_addr),
-	    osmo_hexdump(buf, received));
+	    osmo_hexdump(buf, received > 1000? 1000 : received),
+	    received > 1000 ? "..." : "");
 
 	return received;
 }

openbsc/src/gprs/gtphub_sock.c

@@ -50,8 +50,10 @@ int gtphub_write(const struct osmo_fd *to,
 		LOG(LOGL_ERROR, "sent(%d) != data_len(%d)\n",
 		    (int)sent, (int)buf_len);
 	else
-		LOG(LOGL_DEBUG, "Sent %d: %s\n",
-		    (int)sent, osmo_hexdump(buf, sent));
+		LOG(LOGL_DEBUG, "Sent %d: %s%s\n",
+		    (int)sent,
+		    osmo_hexdump(buf, sent > 1000? 1000 : sent),
+		    sent > 1000 ? "..." : "");
 
 	return 0;
 }