Create RADIUS_MAX_MSG_LEN param in the shared radius.h

The RADIUS client currently uses a hardcoded value of 3000 for the
maximum length of a RADIUS message, and the RADIUS server currently
defines a constant value for the maximum length of the RADIUS message
within its source. The client and the server should use the same
maximum length value, so this change creates a shared parameter
RADIUS_MAX_MSG_LEN within the header file radius.h and modifies
both the client and the server to use that parameter instead of
a locally set value.

Signed-off-by: Anusha Datar <anusha@meter.com>
Reviewed-by: Steve deRosier <derosier@cal-sierra.com>
Reviewed-by: Julian Squires <julian@cipht.net>

src/radius/radius.h

@@ -225,6 +225,8 @@ struct radius_msg;
 /* Default size to be allocated for attribute array */
 #define RADIUS_DEFAULT_ATTR_COUNT 16
 
+/* Maximum message length for incoming RADIUS messages */
+#define RADIUS_MAX_MSG_LEN 3000
 
 /* MAC address ASCII format for IEEE 802.1X use
  * (draft-congdon-radius-8021x-20.txt) */

src/radius/radius_client.c

@@ -816,7 +816,7 @@ static void radius_client_receive(int sock, void *eloop_ctx, void *sock_ctx)
 	struct hostapd_radius_servers *conf = radius->conf;
 	RadiusType msg_type = (RadiusType) sock_ctx;
 	int len, roundtrip;
-	unsigned char buf[3000];
+	unsigned char buf[RADIUS_MAX_MSG_LEN + 1];
 	struct radius_msg *msg;
 	struct radius_hdr *hdr;
 	struct radius_rx_handler *handlers;

src/radius/radius_server.c

@@ -35,11 +35,6 @@
  */
 #define RADIUS_MAX_SESSION 1000
 
-/**
- * RADIUS_MAX_MSG_LEN - Maximum message length for incoming RADIUS messages
- */
-#define RADIUS_MAX_MSG_LEN 3000
-
 static const struct eapol_callbacks radius_server_eapol_cb;
 
 struct radius_client;