If a packet is too long, truncate at the last good attribute

diff --git a/src/lib/radius.c b/src/lib/radius.c
index c352273..6c73e8f 100644 (file)
--- a/src/lib/radius.c
+++ b/src/lib/radius.c
@@ -658,18 +658,6 @@ int rad_encode(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
                }
                
                /*
-                *      Check that the packet is no more than 4k in
-                *      size, AFTER over-flowing the 4k boundary.
-                *      Note that the 'data' buffer, above, is one
-                *      attribute longer than necessary, in order to
-                *      permit this overflow.
-                */
-               if (total_length > MAX_PACKET_LEN) {
-                       librad_log("ERROR: Too many attributes for packet, result is larger than RFC maximum of 4k");
-                       return -1;
-               }
-               
-               /*
                 *      Set the Message-Authenticator to the correct
                 *      length and initial value.
                 */
@@ -688,6 +676,19 @@ int rad_encode(RADIUS_PACKET *packet, const RADIUS_PACKET *original,
 
                len = rad_vp2attr(packet, original, secret, reply, ptr);
                if (len < 0) return -1;
+
+               /*
+                *      Check that the packet is no more than 4k in
+                *      size, AFTER writing the attribute past the 4k
+                *      boundary, but BEFORE deciding to increase the
+                *      size of the packet. Note that the 'data'
+                *      buffer, above, is one attribute longer than
+                *      necessary, in order to permit this overflow.
+                */
+               if ((total_length + len) > MAX_PACKET_LEN) {
+                       break;
+               }
+
                ptr += len;
                total_length += len;
        } /* done looping over all attributes */