README.md

@@ -22,7 +22,7 @@ packetdrill. If you are on a Linux system based on Debian/Ubuntu then you can
 use a command like:
 
 ```
-sudo apt install git gcc make bison flex python net-tools
+sudo apt install git gcc make bison flex python3 net-tools
 ```
 
 To check out and build packetdrill:

gtests/net/packetdrill/config.c

@@ -244,6 +244,8 @@ static void set_wire_client_defaults(struct config *config)
 	if (!config->is_wire_client)
 		return;
 
+	DEBUGP("setting wire client defaults\n");
+
 	if (config->wire_server_ip_string == NULL)
 		die("when using --wire_client, must specify "
 		    "--wire_server_at or --wire_server_ip");

gtests/net/packetdrill/wire_client.c

@@ -139,16 +139,28 @@ static void wire_client_send_hw_address(struct wire_client *wire_client,
 				"error sending WIRE_HARDWARE_ADDR");
 }
 
-/* Send the IP address to which the server should send packets. */
-static void wire_client_send_ip_address(struct wire_client *wire_client,
-					const struct config *config)
+/* Send the IP live_local address to which the server should send packets. */
+static void wire_client_send_live_local_ip(struct wire_client *wire_client,
+					   const struct config *config)
 {
 	if (wire_conn_write(wire_client->wire_conn,
-			    WIRE_IP_ADDR,
+			    WIRE_LIVE_LOCAL_IP,
 			    config->live_local_ip_string,
 			    strlen(config->live_local_ip_string)))
 		wire_client_die(wire_client,
-				"error sending WIRE_IP_ADDR");
+				"error sending WIRE_LIVE_LOCAL_IP");
+}
+
+/* Send the IP live_remote address from which the server should send packets. */
+static void wire_client_send_live_remote_ip(struct wire_client *wire_client,
+					   const struct config *config)
+{
+	if (wire_conn_write(wire_client->wire_conn,
+			    WIRE_LIVE_REMOTE_IP,
+			    config->live_remote_ip_string,
+			    strlen(config->live_remote_ip_string)))
+		wire_client_die(wire_client,
+				"error sending WIRE_LIVE_REMOTE_IP");
 }
 
 /* Receive server's message that the server is ready to execute the script. */
@@ -277,7 +289,9 @@ int wire_client_init(struct wire_client *wire_client,
 
 	wire_client_send_hw_address(wire_client, config);
 
-	wire_client_send_ip_address(wire_client, config);
+	wire_client_send_live_local_ip(wire_client, config);
+
+	wire_client_send_live_remote_ip(wire_client, config);
 
 	wire_client_receive_server_ready(wire_client);
 

gtests/net/packetdrill/wire_protocol.c

@@ -36,7 +36,8 @@ const char *wire_op_to_string(enum wire_op_t op)
 	case WIRE_SCRIPT_PATH:		return "WIRE_SCRIPT_PATH";
 	case WIRE_SCRIPT:		return "WIRE_SCRIPT";
 	case WIRE_HARDWARE_ADDR:	return "WIRE_HARDWARE_ADDR";
-	case WIRE_IP_ADDR:		return "WIRE_IP_ADDR";
+	case WIRE_LIVE_LOCAL_IP:	return "WIRE_LIVE_LOCAL_IP";
+	case WIRE_LIVE_REMOTE_IP:	return "WIRE_LIVE_REMOTE_IP";
 	case WIRE_SERVER_READY:		return "WIRE_SERVER_READY";
 	case WIRE_CLIENT_STARTING:	return "WIRE_CLIENT_STARTING";
 	case WIRE_PACKETS_START:	return "WIRE_PACKETS_START";

gtests/net/packetdrill/wire_protocol.h

@@ -34,7 +34,8 @@ enum wire_op_t {
 	WIRE_SCRIPT_PATH,	/* "here's the path of the script" */
 	WIRE_SCRIPT,		/* "here's the script we're going to start" */
 	WIRE_HARDWARE_ADDR,	/* "here's my ethernet MAC address" */
-	WIRE_IP_ADDR,		/* "here's the client live_local_ip_string */
+	WIRE_LIVE_LOCAL_IP,	/* "here's the client live_local_ip_string */
+	WIRE_LIVE_REMOTE_IP,	/* "here's the live_remote_ip_string to use */
 	WIRE_SERVER_READY,	/* "server ready to start script execution" */
 	WIRE_CLIENT_STARTING,	/* "i'm starting script execution... now!" */
 	WIRE_PACKETS_START,	/* "please start handling packet events" */

gtests/net/packetdrill/wire_server.c

@@ -207,8 +207,8 @@ static int wire_server_receive_hw_address(struct wire_server *wire_server)
 	return STATUS_OK;
 }
 
-/* Receive the IP address to which the server should send packets. */
-static int wire_server_receive_ip_address(struct wire_server *wire_server)
+/* Receive the live_local IP address to which the server should send packets. */
+static int wire_server_receive_live_local_ip(struct wire_server *wire_server)
 {
 	enum wire_op_t op = WIRE_INVALID;
 	void *buf = NULL;
@@ -217,9 +217,9 @@ static int wire_server_receive_ip_address(struct wire_server *wire_server)
 
 	if (wire_conn_read(wire_server->wire_conn, &op, &buf, &buf_len))
 		return STATUS_ERR;
-	if (op != WIRE_IP_ADDR) {
+	if (op != WIRE_LIVE_LOCAL_IP) {
 		fprintf(stderr,
-			"bad wire client: expected WIRE_IP_ADDR\n");
+			"bad wire client: expected WIRE_LIVE_LOCAL_IP\n");
 		return STATUS_ERR;
 	}
 	if (buf_len + 1 > sizeof(config->live_local_ip_string)) {
@@ -230,7 +230,37 @@ static int wire_server_receive_ip_address(struct wire_server *wire_server)
 
 	memcpy(config->live_local_ip_string, buf, buf_len);
 	config->live_local_ip_string[buf_len] = '\0';  /* NULL-terminate str */
-	DEBUGP("got WIRE_IP_ADDR: [%s]\n", config->live_local_ip_string);
+	DEBUGP("got WIRE_LIVE_LOCAL_IP: [%s]\n",
+	       config->live_local_ip_string);
+
+	return STATUS_OK;
+}
+
+/* Receive the live_remote IP from which the server should send packets. */
+static int wire_server_receive_live_remote_ip(struct wire_server *wire_server)
+{
+	enum wire_op_t op = WIRE_INVALID;
+	void *buf = NULL;
+	int buf_len = -1;
+	struct config *config = &wire_server->config;
+
+	if (wire_conn_read(wire_server->wire_conn, &op, &buf, &buf_len))
+		return STATUS_ERR;
+	if (op != WIRE_LIVE_REMOTE_IP) {
+		fprintf(stderr,
+			"bad wire client: expected WIRE_LIVE_REMOTE_IP\n");
+		return STATUS_ERR;
+	}
+	if (buf_len + 1 > sizeof(config->live_remote_ip_string)) {
+		fprintf(stderr,
+			"bad wire client: ip address too long\n");
+		return STATUS_ERR;
+	}
+
+	memcpy(config->live_remote_ip_string, buf, buf_len);
+	config->live_remote_ip_string[buf_len] = '\0';  /* NULL-terminate str */
+	DEBUGP("got WIRE_LIVE_REMOTE_IP: [%s]\n",
+	       config->live_remote_ip_string);
 
 	return STATUS_OK;
 }
@@ -484,7 +514,10 @@ static void *wire_server_thread(void *arg)
 	if (wire_server_receive_hw_address(wire_server))
 		goto error_done;
 
-	if (wire_server_receive_ip_address(wire_server))
+	if (wire_server_receive_live_local_ip(wire_server))
+		goto error_done;
+
+	if (wire_server_receive_live_remote_ip(wire_server))
 		goto error_done;
 
 	if (parse_script_and_set_config(wire_server->argc,

gtests/net/tcp/cubic/cubic-bulk-166k-idle-restart.pkt

@@ -0,0 +1,111 @@
+// Test bulk CUBIC flow at 166 kbit/sec (2 1000-byte payloads each 100ms
+// means 2 * 1040 * 8 / .1 = 166400 bits/sec).
+// This variant checks to see if CUBIC grows its cwnd unreasonably
+// due to crediting itself for time accumulated in an idle state.
+
+// For this test We mostly just care about cwnd values, not exact timing.
+// So to reduce flakes allow ~20ms of timing variation:
+--tolerance_usecs=20000
+
+`../../common/defaults.sh
+tc qdisc replace dev tun0 root fq
+sysctl -q net.ipv4.tcp_congestion_control=cubic
+sysctl -q net.ipv4.tcp_min_tso_segs=4
+# Disable TLP to avoid flakes from spurious retransmits:
+sysctl -q net.ipv4.tcp_early_retrans=0`
+
+// Initialize connection
+    0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
+   +0 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
+   +0 bind(3, ..., ...) = 0
+   +0 listen(3, 1) = 0
+
+   +0 < S 0:0(0) win 32792 <mss 1000,sackOK,nop,nop,nop,wscale 10>
+   +0 > S. 0:0(0) ack 1 <mss 1460,nop,nop,sackOK,nop,wscale 8>
+  +.1 < . 1:1(0) ack 1 win 514
+
+   +0 accept(3, ..., ...) = 4
+
+   +0 setsockopt(4, SOL_SOCKET, SO_SNDBUF, [2000000], 4) = 0
+   +0 %{ assert tcpi_snd_cwnd == 10, tcpi_snd_cwnd }%
+   +0 write(4, ..., 40000) = 40000
+
+  +.1 < .  1:1(0) ack 2001 win 514
+  +.1 < .  1:1(0) ack 4001 win 514
+  +.1 < .  1:1(0) ack 6001 win 514
+  +.1 < .  1:1(0) ack 8001 win 514
+  +.1 < .  1:1(0) ack 10001 win 514
+   +0 %{ print(tcpi_snd_cwnd); assert tcpi_snd_cwnd == 20, tcpi_snd_cwnd }%
+  +.1 < .  1:1(0) ack 12001 win 514
+  +.1 < .  1:1(0) ack 14001 win 514
+  +.1 < .  1:1(0) ack 16001 win 514
+  +.1 < .  1:1(0) ack 18001 win 514
+  +.1 < .  1:1(0) ack 20001 win 514
+   +0 %{ print(tcpi_snd_cwnd); assert tcpi_snd_cwnd == 30, tcpi_snd_cwnd }%
+
+  +.1 < .  1:1(0) ack 22001 win 514
+  +.1 < .  1:1(0) ack 24001 win 514
+  +.1 < .  1:1(0) ack 26001 win 514
+  +.1 < .  1:1(0) ack 28001 win 514
+  +.1 < .  1:1(0) ack 30001 win 514
+   +0 %{ print(tcpi_snd_cwnd); assert tcpi_snd_cwnd == 40, tcpi_snd_cwnd }%
+  +.1 < .  1:1(0) ack 32001 win 514
+  +.1 < .  1:1(0) ack 34001 win 514
+  +.1 < .  1:1(0) ack 36001 win 514
+  +.1 < .  1:1(0) ack 38001 win 514
+// Hystart exits slow start here at a cwnd of 48:
+   +0 %{ print(tcpi_snd_cwnd); assert tcpi_snd_cwnd == 48, tcpi_snd_cwnd }%
+  +.1 < .  1:1(0) ack 40001 win 514
+
+// Go idle for a while in order to verify that this doesn't let us
+// accumulate "credit" toward increasing cwnd quickly when we go
+// cwnd-limited again.
+   +4 write(4, ..., 160000) = 160000
+
+  +.1 < .  1:1(0) ack 42001 win 514
+  +.1 < .  1:1(0) ack 44001 win 514
+  +.1 < .  1:1(0) ack 46001 win 514
+  +.1 < .  1:1(0) ack 48001 win 514
+  +.1 < .  1:1(0) ack 50001 win 514
+  +.1 < .  1:1(0) ack 52001 win 514
+  +.1 < .  1:1(0) ack 54001 win 514
+  +.1 < .  1:1(0) ack 56001 win 514
+  +.1 < .  1:1(0) ack 58001 win 514
+  +.1 < .  1:1(0) ack 60001 win 514
+   +0 %{ print(tcpi_snd_cwnd);  assert tcpi_snd_cwnd == 48, tcpi_snd_cwnd }%
+
+  +.1 < .  1:1(0) ack 62001 win 514
+  +.1 < .  1:1(0) ack 64001 win 514
+  +.1 < .  1:1(0) ack 66001 win 514
+  +.1 < .  1:1(0) ack 68001 win 514
+  +.1 < .  1:1(0) ack 70001 win 514
+  +.1 < .  1:1(0) ack 72001 win 514
+  +.1 < .  1:1(0) ack 74001 win 514
+  +.1 < .  1:1(0) ack 76001 win 514
+  +.1 < .  1:1(0) ack 78001 win 514
+  +.1 < .  1:1(0) ack 80001 win 514
+   +0 %{ print(tcpi_snd_cwnd);  assert tcpi_snd_cwnd == 49, tcpi_snd_cwnd }%
+
+  +.1 < .  1:1(0) ack 82001 win 514
+  +.1 < .  1:1(0) ack 84001 win 514
+  +.1 < .  1:1(0) ack 86001 win 514
+  +.1 < .  1:1(0) ack 88001 win 514
+  +.1 < .  1:1(0) ack 90001 win 514
+  +.1 < .  1:1(0) ack 92001 win 514
+  +.1 < .  1:1(0) ack 94001 win 514
+  +.1 < .  1:1(0) ack 96001 win 514
+  +.1 < .  1:1(0) ack 98001 win 514
+  +.1 < .  1:1(0) ack 100001 win 514
+   +0 %{ print(tcpi_snd_cwnd);  assert tcpi_snd_cwnd == 52, tcpi_snd_cwnd }%
+
+  +.1 < .  1:1(0) ack 102001 win 514
+  +.1 < .  1:1(0) ack 104001 win 514
+  +.1 < .  1:1(0) ack 106001 win 514
+  +.1 < .  1:1(0) ack 108001 win 514
+  +.1 < .  1:1(0) ack 110001 win 514
+  +.1 < .  1:1(0) ack 112001 win 514
+  +.1 < .  1:1(0) ack 114001 win 514
+  +.1 < .  1:1(0) ack 116001 win 514
+  +.1 < .  1:1(0) ack 118001 win 514
+  +.1 < .  1:1(0) ack 120001 win 514
+   +0 %{ print(tcpi_snd_cwnd);  assert tcpi_snd_cwnd == 58, tcpi_snd_cwnd }%