Merge pull request #10 from Masaq-/extended-options

improvements for empty pings mode

src/pdesc.h

@@ -156,6 +156,7 @@ typedef struct proxy_desc_t {
 	double last_ack;
 	/** Time when a packet was last received. */
 	double last_activity;
+	double last_data_activity;
 	uint16_t window_size;
 	double ack_interval;
 	double resend_interval;

src/pkt.c

@@ -297,6 +297,10 @@ void handle_packet(char *buf, unsigned bytes, int is_pcap, struct sockaddr_in *a
 				}
 
 				if (cur && cur->sock) {
+					double now = time_as_double();
+					if (pt_pkt->state != kProto_ack) {
+						cur->last_data_activity = now;
+					}
 					if (pt_pkt->state == kProto_data || pt_pkt->state == kProxy_start ||
 					    pt_pkt->state   == kProto_ack)
 					{
@@ -309,7 +313,7 @@ void handle_packet(char *buf, unsigned bytes, int is_pcap, struct sockaddr_in *a
 					handle_ack((uint16_t)pt_pkt->ack, cur->send_ring, &cur->send_wait_ack,
 					           0, cur->send_idx, &cur->send_first_ack, &cur->remote_ack_val,
 					           is_pcap, cur->window_size);
-					cur->last_activity      = time_as_double();
+					cur->last_activity = now;
 				}
 			}
 		}
@@ -432,10 +436,14 @@ void handle_extended_options(void *vcur)
 {
 	proxy_desc_t *cur = (proxy_desc_t *)vcur;
 	if (cur->extended_options[0] > 0) {
-		remove_proxy_desc_rings(cur);
+		if (cur->extended_options[0] > cur->window_size) {
+			size_t extend = cur->extended_options[0] - cur->window_size;
+			cur->send_ring = realloc(cur->send_ring, cur->extended_options[0] * sizeof(icmp_desc_t));
+			cur->recv_ring = realloc(cur->recv_ring, cur->extended_options[0] * sizeof(forward_desc_t *));
+			memset(cur->send_ring + cur->window_size, 0, extend * sizeof(icmp_desc_t));
+			memset(cur->recv_ring + cur->window_size, 0, extend * sizeof(forward_desc_t *));
+		}
 		cur->window_size = cur->extended_options[0];
-		cur->send_ring = calloc(cur->window_size, sizeof(icmp_desc_t));
-		cur->recv_ring = calloc(cur->window_size, sizeof(forward_desc_t *));
 		pt_log(kLog_verbose, "Received extended option for window size %d \n", cur->window_size);
 	}
 	if (cur->extended_options[1] > 0) {

src/ptunnel.c

@@ -662,21 +662,25 @@ void* pt_proxy(void *args) {
 			    cur->remote_ack_val+1 != cur->next_remote_seq)
 			{
 				idx = cur->send_idx;
-				cur->last_ack = now;
 				queue_packet(fwd_sock, cur->pkt_type, 0, 0, cur->id_no, cur->icmp_id,
 				             &cur->my_seq, cur->send_ring, &cur->send_idx, &cur->send_wait_ack,
 				             cur->dst_ip, cur->dst_port, kProto_ack | cur->type_flag,
 				             &cur->dest_addr, cur->next_remote_seq, &cur->send_first_ack, &cur->ping_seq, cur->window_size);
 				cur->xfer.icmp_ack_out++;
-				if (cur->send_ring[idx].pkt_len > sizeof(icmp_echo_packet_t) && cur->send_ring[idx].pkt->type == kICMP_echo_request) {
+				if (opts.empty_pings &&
+					cur->last_data_activity > cur->last_ack &&
+					cur->send_ring[idx].pkt_len > sizeof(icmp_echo_packet_t) &&
+					cur->send_ring[idx].pkt->type == kICMP_echo_request) {
 					for (uint16_t e = 0; e < opts.empty_pings; e++) {
 						cur->send_ring[idx].pkt->seq      = htons(cur->ping_seq);
 						cur->ping_seq++;
+						cur->send_ring[idx].pkt->checksum = 0;
 						cur->send_ring[idx].pkt->checksum = htons(calc_icmp_checksum((uint16_t*)cur->send_ring[idx].pkt, sizeof(icmp_echo_packet_t)));
 						sendto(fwd_sock, (const void*)cur->send_ring[idx].pkt, sizeof(icmp_echo_packet_t),
 						       0, (struct sockaddr*)&cur->dest_addr, sizeof(struct sockaddr));
 					}
 				}
+				cur->last_ack = now;
 			}
 		}
 		pthread_mutex_unlock(&chain_lock);