[PATCH 04/10] net: netconsole: cache environment settings

nc_refresh_settings_from_env() compares the current environment ID
with a cached value, but never updates the cache. It consequently
reparses the environment for every packet.

Build a complete settings value from the defaults whenever the
environment changes, publish it after successful parsing and record the
new ID. Keeping the defaults with the cached settings also avoids
resetting configured ports when another stdio stream starts.

Signed-off-by: James Hilliard <[email protected]>
---
 drivers/net/netconsole.c | 34 +++++++++++++++++++++-------------
 1 file changed, 21 insertions(+), 13 deletions(-)

diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c
index 305a6cf12c6..63b92e12bf4 100644
--- a/drivers/net/netconsole.c
+++ b/drivers/net/netconsole.c
@@ -16,12 +16,18 @@
 #define CFG_NETCONSOLE_BUFFER_SIZE 512
 #endif
 
+#define NC_DEFAULT_PORT 6666
+
 static char input_buffer[CFG_NETCONSOLE_BUFFER_SIZE];
 static int input_size; /* char count in input buffer */
 static int input_offset; /* offset to valid chars in input buffer */
 static int input_recursion;
 static int output_recursion;
-struct nc_settings nc_settings;
+struct nc_settings nc_settings = {
+	.ip.s_addr = ~0,
+	.out_port = NC_DEFAULT_PORT,
+	.in_port = NC_DEFAULT_PORT,
+};
 
 bool nc_is_broadcast(struct in_addr ip)
 {
@@ -46,8 +52,13 @@ bool nc_is_broadcast(struct in_addr ip)
 
 int nc_refresh_settings_from_env(void)
 {
+	struct nc_settings settings = {
+		.ip.s_addr = ~0,
+		.out_port = NC_DEFAULT_PORT,
+		.in_port = NC_DEFAULT_PORT,
+	};
 	const char *p;
-	static int env_changed_id;
+	static int env_changed_id = -1;
 	int env_id = env_get_id();
 
 	/* update only when the environment has changed */
@@ -55,25 +66,25 @@ int nc_refresh_settings_from_env(void)
 		char *tmp = env_get("ncip");
 
 		if (tmp) {
-			nc_settings.ip = string_to_ip(tmp);
-			if (!nc_settings.ip.s_addr)
+			settings.ip = string_to_ip(tmp);
+			if (!settings.ip.s_addr)
 				return -1;	/* ncip is 0.0.0.0 */
 			p = strchr(tmp, ':');
 			if (p != NULL) {
-				nc_settings.out_port = dectoul(p + 1, NULL);
-				nc_settings.in_port = nc_settings.out_port;
+				settings.out_port = dectoul(p + 1, NULL);
+				settings.in_port = settings.out_port;
 			}
-		} else {
-			nc_settings.ip.s_addr = ~0;
 		}
 
 		p = env_get("ncoutport");
 		if (p != NULL)
-			nc_settings.out_port = dectoul(p, NULL);
+			settings.out_port = dectoul(p, NULL);
 		p = env_get("ncinport");
 		if (p != NULL)
-			nc_settings.in_port = dectoul(p, NULL);
+			settings.in_port = dectoul(p, NULL);
 
+		nc_settings = settings;
+		env_changed_id = env_id;
 		return 1;
 	}
 
@@ -130,9 +141,6 @@ int nc_input_packet(uchar *pkt, struct in_addr src_ip, unsigned dest_port,
 
 static int nc_stdio_start(struct stdio_dev *dev)
 {
-	nc_settings.out_port = 6666;
-	nc_settings.in_port = nc_settings.out_port;
-
 	return nc_transport_start();
 }
 

-- 
2.53.0