Merge pull request #333 from DrDoof/feat/syslog-hostname-port

syslog: send a hostname, allow a port other than 514, and stop the save from dropping the address

cmd_parser.c

@@ -67,6 +67,10 @@ __xdata	char save_cmd;
 
 __xdata uint8_t ip[4];
 
+/* Scratch for parse_syslog(), in xdata: a local here would take internal RAM
+ * the linker has none of. */
+__xdata uint8_t  syslog_port_was_on;
+
 // These variables combined create a Fixed-capacity vector/bounded buffer.
 // `N_WORDS`: The total number of command arguments that can be tracked.
 // `cmd_words_len` stores the number of arguments found inside `cmd_buffer`
@@ -1415,6 +1419,7 @@ void parse_syslog(void)
 		if (syslog_state.enabled) {
 			print_string("enabled, sending to ");
 			print_ip(syslog_state.server_ip);
+			write_char(':'); itoa_short(syslog_state.server_port);
 			write_char('\n');
 		} else {
 			print_string("disabled\n");
@@ -1443,11 +1448,34 @@ void parse_syslog(void)
 		} else {
 			print_string("Invalid IP address\n");
 		}
+	} else if (cmd_compare(1, "port")) {
+		if (cmd_words_len < 3) { // no additional argument -> print current port
+			print_string("Current syslog port: ");
+			itoa_short(syslog_state.server_port); write_char('\n');
+			return;
+		}
+		/* atoi_short() returns zero for no digits and for a value past
+		 * 65535; port zero is not a port either, so both tests are needed. */
+		if (!atoi_short(cmd_words_b[2]) || !atoi_results_short) {
+			print_string("Invalid port\n");
+			return;
+		}
+		/* The port is frozen into the connection by uip_udp_new(), so
+		 * changing it has to tear the connection down and build a new one -
+		 * same dance as setting the address above. */
+		syslog_port_was_on = syslog_state.enabled;
+		if (syslog_port_was_on)
+			syslog_stop();
+		print_string("Setting new syslog port.\n");
+		syslog_state.server_port = atoi_results_short;
+		if (syslog_port_was_on)
+			syslog_start();
 	}
 	else
 	{
-		print_string("Error: syslog [on|off|ip [ip-address]]\n");
-		print_string("  on/off enables or disables syslog, ip sets the syslog server IP address\n");
+		print_string("Error: syslog [on|off|ip [ip-address]|port [number]]\n");
+		print_string("  on/off enables or disables syslog, ip sets the syslog server IP address,\n");
+		print_string("  port sets the destination UDP port (default 514)\n");
 	}
 }