save a copy of the packet only if we're going to resend it

src/modules/rlm_radius/bio.c

@@ -614,6 +614,11 @@ static void conn_init_writable(fr_event_list_t *el, UNUSED int fd, UNUSED int fl
 		PERROR("%s - Failed inserting timer event", h->ctx.module_name);
 		goto fail;
 	}
+
+	/*
+	 *	Save a copy of the header + Authentication Vector for checking the response.
+	 */
+	MEM(u->packet = talloc_memdup(u, u->packet, RADIUS_HEADER_LENGTH));
 }
 
 /** Free a connection handle, closing associated resources
@@ -1255,13 +1260,6 @@ static int encode(bio_handle_t *h, request_t *request, bio_request_t *u, uint8_t
 		goto error;
 	}
 
-	/*
-	 *	Keep a copy of the packet for potential retransmission.
-	 *
-	 *	@todo - do this only for UDP.
-	 */
-	MEM(u->packet = talloc_memdup(u, h->buffer, packet_len));
-
 	return 0;
 }
 
@@ -1657,6 +1655,11 @@ static void mod_write(request_t *request, trunk_request_t *treq, bio_handle_t *h
 
 	packet_len += slen;
 	if (packet_len < u->packet_len) {
+		/*
+		 *	The first time around, save a copy of the packet for later writing.
+		 */
+		if (!u->partial) MEM(u->packet = talloc_memdup(u, u->packet, u->packet_len));
+
 		u->partial = packet_len;
 		trunk_request_signal_partial(treq);
 		return;
@@ -1710,6 +1713,18 @@ static void mod_write(request_t *request, trunk_request_t *treq, bio_handle_t *h
 		 */
 		RDEBUG("%s request.  Relying on NAS to perform more retransmissions", action);
 	}
+
+	/*
+	 *	We don't retransmit over TCP.
+	 */
+	if (h->ctx.fd_config->type != SOCK_DGRAM) return;
+
+	/*
+	 *	If we only send one datagram packet, then don't bother saving it.
+	 */
+	if (u->retry.config && u->retry.config->mrc == 1) return;
+
+	MEM(u->packet = talloc_memdup(u, u->packet, u->packet_len));
 }
 
 /** Deal with Protocol-Error replies, and possible negotiation