wpa_debug: Support outputting hexdumps into syslog

This patch allows to log hexdumps into syslog.

This is useful when testing, as syslog's network logging
helps to collect debug outputs from several machines.

Signed-hostapd: Nicolas Cavallari <cavallar@lri.fr>

src/utils/wpa_debug.c

@@ -166,6 +166,38 @@ static void _wpa_hexdump(int level, const char *title, const u8 *buf,
 	size_t i;
 	if (level < wpa_debug_level)
 		return;
+#ifdef CONFIG_DEBUG_SYSLOG
+	if (wpa_debug_syslog) {
+		const char *display;
+		char *strbuf = NULL;
+
+		if (buf == NULL) {
+			display = " [NULL]";
+		} else if (len == 0) {
+			display = "";
+		} else if (show && len) {
+			strbuf = os_malloc(1 + 3 * len);
+			if (strbuf == NULL) {
+				wpa_printf(MSG_ERROR, "wpa_hexdump: Failed to "
+					   "allocate message buffer");
+				return;
+			}
+
+			for (i = 0; i < len; i++)
+				os_snprintf(&strbuf[i * 3], 4, " %02x",
+					    buf[i]);
+
+			display = strbuf;
+		} else {
+			display = " [REMOVED]";
+		}
+
+		syslog(syslog_priority(level), "%s - hexdump(len=%lu):%s",
+		       title, len, display);
+		os_free(strbuf);
+		return;
+	}
+#endif /* CONFIG_DEBUG_SYSLOG */
 	wpa_debug_print_timestamp();
 #ifdef CONFIG_DEBUG_FILE
 	if (out_file) {