aboutsummaryrefslogtreecommitdiffstats
path: root/src
diff options
context:
space:
mode:
authorFlorin Coras <fcoras@cisco.com>2017-05-07 19:12:02 -0700
committerDamjan Marion <dmarion.lists@gmail.com>2017-05-09 14:38:56 +0000
commitf6d68ed2db2bcd41c9b7ddde5e411073c1566c29 (patch)
tree7477fb7b0187d36429e9e2d1a348be14157ebb09 /src
parent1ea82dfe5dabb0f9bbfa5ba953ef31328c987b89 (diff)
Add support for tcp/session buffer chains
Change-Id: I01c6e3dc3a1b2785df37bb66b19c4b5cbb8f3211 Signed-off-by: Florin Coras <fcoras@cisco.com>
Diffstat (limited to 'src')
-rw-r--r--src/scripts/vnet/uri/dummy_app.py19
-rw-r--r--src/uri/uri_socket_server.c47
-rw-r--r--src/vnet/session/node.c172
-rw-r--r--src/vnet/session/session.c89
-rw-r--r--src/vnet/session/session.h4
-rw-r--r--src/vnet/tcp/tcp_input.c16
-rw-r--r--src/vnet/tcp/tcp_output.c4
7 files changed, 266 insertions, 85 deletions
diff --git a/src/scripts/vnet/uri/dummy_app.py b/src/scripts/vnet/uri/dummy_app.py
index 50333923d6e..ff00f2fc8c6 100644
--- a/src/scripts/vnet/uri/dummy_app.py
+++ b/src/scripts/vnet/uri/dummy_app.py
@@ -6,14 +6,28 @@ import time
# action can be reflect or drop
action = "drop"
+test = 0
+
+def test_data (data, n_rcvd):
+ n_read = len (data);
+ for i in range(n_read):
+ expected = (n_rcvd + i) & 0xff
+ byte_got = ord (data[i])
+ if (byte_got != expected):
+ print("Difference at byte {}. Expected {} got {}"
+ .format(n_rcvd + i, expected, byte_got))
+ return n_read
def handle_connection (connection, client_address):
print("Received connection from {}".format(repr(client_address)))
+ n_rcvd = 0
try:
while True:
data = connection.recv(4096)
if not data:
break;
+ if (test == 1):
+ n_rcvd += test_data (data, n_rcvd)
if (action != "drop"):
connection.sendall(data)
finally:
@@ -78,8 +92,9 @@ def run(mode, ip, port):
if __name__ == "__main__":
if (len(sys.argv)) < 4:
- raise Exception("Usage: ./dummy_app <mode> <ip> <port> [<action>]")
- if (len(sys.argv) == 5):
+ raise Exception("Usage: ./dummy_app <mode> <ip> <port> [<action> <test>]")
+ if (len(sys.argv) == 6):
action = sys.argv[4]
+ test = int(sys.argv[5])
run (sys.argv[1], sys.argv[2], int(sys.argv[3]))
diff --git a/src/uri/uri_socket_server.c b/src/uri/uri_socket_server.c
index 64d3b49252a..2366f420126 100644
--- a/src/uri/uri_socket_server.c
+++ b/src/uri/uri_socket_server.c
@@ -17,6 +17,7 @@
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
+#include <arpa/inet.h>
#include <netdb.h>
#include <vppinfra/format.h>
#include <signal.h>
@@ -72,32 +73,59 @@ setup_signal_handler (void)
int
main (int argc, char *argv[])
{
- int sockfd, portno, n, sent, accfd;
+ int sockfd, portno, n, sent, accfd, reuse;
+ socklen_t client_addr_len;
struct sockaddr_in serv_addr;
+ struct sockaddr_in client;
struct hostent *server;
u8 *rx_buffer = 0;
- if (0 && argc < 3)
+ if (argc > 1 && argc < 3)
{
- fformat (stderr, "usage %s hostname port\n", argv[0]);
+ fformat (stderr, "usage %s host port\n", argv[0]);
exit (0);
}
+ if (argc >= 3)
+ {
+ portno = atoi (argv[2]);
+ server = gethostbyname (argv[1]);
+ if (server == NULL)
+ {
+ clib_unix_warning ("gethostbyname");
+ exit (1);
+ }
+ }
+ else
+ {
+ /* Defaults */
+ portno = 1234;
+ server = gethostbyname ("6.0.1.1");
+ if (server == NULL)
+ {
+ clib_unix_warning ("gethostbyname");
+ exit (1);
+ }
+ }
+
+
setup_signal_handler ();
- portno = 1234; // atoi(argv[2]);
sockfd = socket (AF_INET, SOCK_STREAM, 0);
if (sockfd < 0)
{
clib_unix_error ("socket");
exit (1);
}
- server = gethostbyname ("6.0.1.1");
- if (server == NULL)
+
+ reuse = 1;
+ if (setsockopt (sockfd, SOL_SOCKET, SO_REUSEADDR, (const char *) &reuse,
+ sizeof (reuse)) < 0)
{
- clib_unix_warning ("gethostbyname");
+ clib_unix_error ("setsockopt(SO_REUSEADDR) failed");
exit (1);
}
+
bzero ((char *) &serv_addr, sizeof (serv_addr));
serv_addr.sin_family = AF_INET;
bcopy ((char *) server->h_addr,
@@ -123,12 +151,15 @@ main (int argc, char *argv[])
if (signal_received)
break;
- accfd = accept (sockfd, 0 /* don't care */ , 0);
+ client_addr_len = sizeof (struct sockaddr);
+ accfd = accept (sockfd, (struct sockaddr *) &client, &client_addr_len);
if (accfd < 0)
{
clib_unix_warning ("accept");
continue;
}
+ fformat (stderr, "Accepted connection from: %s : %d\n",
+ inet_ntoa (client.sin_addr), client.sin_port);
while (1)
{
n = recv (accfd, rx_buffer, vec_len (rx_buffer), 0 /* flags */ );
diff --git a/src/vnet/session/node.c b/src/vnet/session/node.c
index 2d12ee2bac9..ce7c38683f5 100644
--- a/src/vnet/session/node.c
+++ b/src/vnet/session/node.c
@@ -70,6 +70,58 @@ static u32 session_type_to_next[] = {
SESSION_QUEUE_NEXT_IP6_LOOKUP,
};
+always_inline void
+session_tx_fifo_chain_tail (session_manager_main_t * smm, vlib_main_t * vm,
+ u8 thread_index, svm_fifo_t * fifo,
+ vlib_buffer_t * b0, u32 bi0, u8 n_bufs_per_seg,
+ u32 * left_to_snd0, u16 * n_bufs, u32 * rx_offset,
+ u16 deq_per_buf, u8 peek_data)
+{
+ vlib_buffer_t *chain_b0, *prev_b0;
+ u32 chain_bi0;
+ u16 len_to_deq0, n_bytes_read;
+ u8 *data0, j;
+
+ chain_bi0 = bi0;
+ chain_b0 = b0;
+ for (j = 1; j < n_bufs_per_seg; j++)
+ {
+ prev_b0 = chain_b0;
+ len_to_deq0 = clib_min (*left_to_snd0, deq_per_buf);
+
+ *n_bufs -= 1;
+ chain_bi0 = smm->tx_buffers[thread_index][*n_bufs];
+ _vec_len (smm->tx_buffers[thread_index]) = *n_bufs;
+
+ chain_b0 = vlib_get_buffer (vm, chain_bi0);
+ chain_b0->current_data = 0;
+ data0 = vlib_buffer_get_current (chain_b0);
+ if (peek_data)
+ {
+ n_bytes_read = svm_fifo_peek (fifo, *rx_offset, len_to_deq0, data0);
+ *rx_offset += n_bytes_read;
+ }
+ else
+ {
+ n_bytes_read = svm_fifo_dequeue_nowait (fifo, len_to_deq0, data0);
+ }
+ ASSERT (n_bytes_read == len_to_deq0);
+ chain_b0->current_length = n_bytes_read;
+ b0->total_length_not_including_first_buffer += chain_b0->current_length;
+
+ /* update previous buffer */
+ prev_b0->next_buffer = chain_bi0;
+ prev_b0->flags |= VLIB_BUFFER_NEXT_PRESENT;
+
+ /* update current buffer */
+ chain_b0->next_buffer = 0;
+
+ *left_to_snd0 -= n_bytes_read;
+ if (*left_to_snd0 == 0)
+ break;
+ }
+}
+
always_inline int
session_tx_fifo_read_and_snd_i (vlib_main_t * vm, vlib_node_runtime_t * node,
session_manager_main_t * smm,
@@ -78,16 +130,17 @@ session_tx_fifo_read_and_snd_i (vlib_main_t * vm, vlib_node_runtime_t * node,
int *n_tx_packets, u8 peek_data)
{
u32 n_trace = vlib_get_trace_count (vm, node);
- u32 left_to_snd0, max_len_to_snd0, len_to_deq0, n_bufs, snd_space0;
- u32 n_frame_bytes, n_frames_per_evt;
+ u32 left_to_snd0, max_len_to_snd0, len_to_deq0, snd_space0;
+ u32 n_bufs_per_evt, n_frames_per_evt;
transport_connection_t *tc0;
transport_proto_vft_t *transport_vft;
u32 next_index, next0, *to_next, n_left_to_next, bi0;
vlib_buffer_t *b0;
- u32 rx_offset = 0, max_dequeue0;
- u16 snd_mss0;
+ u32 rx_offset = 0, max_dequeue0, n_bytes_per_seg;
+ u16 snd_mss0, n_bufs_per_seg, n_bufs;
u8 *data0;
int i, n_bytes_read;
+ u32 n_bytes_per_buf, deq_per_buf;
next_index = next0 = session_type_to_next[s0->session_type];
@@ -134,8 +187,15 @@ session_tx_fifo_read_and_snd_i (vlib_main_t * vm, vlib_node_runtime_t * node,
max_len_to_snd0 = snd_space0;
}
- n_frame_bytes = snd_mss0 * VLIB_FRAME_SIZE;
- n_frames_per_evt = ceil ((double) max_len_to_snd0 / n_frame_bytes);
+ n_bytes_per_buf = vlib_buffer_free_list_buffer_size (vm,
+ VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);
+ n_bytes_per_seg = MAX_HDRS_LEN + snd_mss0;
+ n_bufs_per_seg = ceil ((double) n_bytes_per_seg / n_bytes_per_buf);
+ n_bufs_per_evt = (ceil ((double) max_len_to_snd0 / n_bytes_per_seg))
+ * n_bufs_per_seg;
+ n_frames_per_evt = ceil ((double) n_bufs_per_evt / VLIB_FRAME_SIZE);
+
+ deq_per_buf = clib_min (snd_mss0, n_bytes_per_buf);
n_bufs = vec_len (smm->tx_buffers[thread_index]);
left_to_snd0 = max_len_to_snd0;
@@ -146,9 +206,9 @@ session_tx_fifo_read_and_snd_i (vlib_main_t * vm, vlib_node_runtime_t * node,
{
vec_validate (smm->tx_buffers[thread_index],
n_bufs + VLIB_FRAME_SIZE - 1);
- n_bufs +=
- vlib_buffer_alloc (vm, &smm->tx_buffers[thread_index][n_bufs],
- VLIB_FRAME_SIZE);
+ n_bufs += vlib_buffer_alloc (vm,
+ &smm->tx_buffers[thread_index][n_bufs],
+ VLIB_FRAME_SIZE);
/* buffer shortage
* XXX 0.9 because when debugging we might not get a full frame */
@@ -165,11 +225,14 @@ session_tx_fifo_read_and_snd_i (vlib_main_t * vm, vlib_node_runtime_t * node,
}
vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
- while (left_to_snd0 && n_left_to_next)
+ while (left_to_snd0 && n_left_to_next >= n_bufs_per_seg)
{
+ /*
+ * Handle first buffer in chain separately
+ */
+
/* Get free buffer */
- n_bufs--;
- bi0 = smm->tx_buffers[thread_index][n_bufs];
+ bi0 = smm->tx_buffers[thread_index][--n_bufs];
_vec_len (smm->tx_buffers[thread_index]) = n_bufs;
b0 = vlib_get_buffer (vm, bi0);
@@ -177,52 +240,19 @@ session_tx_fifo_read_and_snd_i (vlib_main_t * vm, vlib_node_runtime_t * node,
b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID
| VNET_BUFFER_LOCALLY_ORIGINATED;
b0->current_data = 0;
+ b0->total_length_not_including_first_buffer = 0;
/* RX on the local interface. tx in default fib */
vnet_buffer (b0)->sw_if_index[VLIB_RX] = 0;
vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
- /* usual speculation, or the enqueue_x1 macro will barf */
- to_next[0] = bi0;
- to_next += 1;
- n_left_to_next -= 1;
-
- VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b0);
- if (PREDICT_FALSE (n_trace > 0))
- {
- session_queue_trace_t *t0;
- vlib_trace_buffer (vm, node, next_index, b0,
- 1 /* follow_chain */ );
- vlib_set_trace_count (vm, node, --n_trace);
- t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
- t0->session_index = s0->session_index;
- t0->server_thread_index = s0->thread_index;
- }
+ len_to_deq0 = clib_min (left_to_snd0, deq_per_buf);
- len_to_deq0 = (left_to_snd0 < snd_mss0) ? left_to_snd0 : snd_mss0;
-
- /* *INDENT-OFF* */
- SESSION_EVT_DBG(SESSION_EVT_DEQ, s0, ({
- ed->data[0] = e0->event_id;
- ed->data[1] = max_dequeue0;
- ed->data[2] = len_to_deq0;
- ed->data[3] = left_to_snd0;
- }));
- /* *INDENT-ON* */
-
- /* Make room for headers */
data0 = vlib_buffer_make_headroom (b0, MAX_HDRS_LEN);
-
- /* Dequeue the data
- * TODO 1) peek instead of dequeue
- * 2) buffer chains */
if (peek_data)
{
n_bytes_read = svm_fifo_peek (s0->server_tx_fifo, rx_offset,
len_to_deq0, data0);
- if (n_bytes_read <= 0)
- goto dequeue_fail;
-
/* Keep track of progress locally, transport is also supposed to
* increment it independently when pushing the header */
rx_offset += n_bytes_read;
@@ -231,18 +261,56 @@ session_tx_fifo_read_and_snd_i (vlib_main_t * vm, vlib_node_runtime_t * node,
{
n_bytes_read = svm_fifo_dequeue_nowait (s0->server_tx_fifo,
len_to_deq0, data0);
- if (n_bytes_read <= 0)
- goto dequeue_fail;
}
- b0->current_length = n_bytes_read;
+ if (n_bytes_read <= 0)
+ goto dequeue_fail;
- /* Ask transport to push header */
- transport_vft->push_header (tc0, b0);
+ b0->current_length = n_bytes_read;
left_to_snd0 -= n_bytes_read;
*n_tx_packets = *n_tx_packets + 1;
+ /*
+ * Fill in the remaining buffers in the chain, if any
+ */
+ if (PREDICT_FALSE (n_bufs_per_seg > 1))
+ session_tx_fifo_chain_tail (smm, vm, thread_index,
+ s0->server_tx_fifo, b0, bi0,
+ n_bufs_per_seg, &left_to_snd0,
+ &n_bufs, &rx_offset, deq_per_buf,
+ peek_data);
+
+ /* Ask transport to push header after current_length and
+ * total_length_not_including_first_buffer are updated */
+ transport_vft->push_header (tc0, b0);
+
+ /* *INDENT-OFF* */
+ SESSION_EVT_DBG(SESSION_EVT_DEQ, s0, ({
+ ed->data[0] = e0->event_id;
+ ed->data[1] = max_dequeue0;
+ ed->data[2] = len_to_deq0;
+ ed->data[3] = left_to_snd0;
+ }));
+ /* *INDENT-ON* */
+
+ /* usual speculation, or the enqueue_x1 macro will barf */
+ to_next[0] = bi0;
+ to_next += 1;
+ n_left_to_next -= 1;
+
+ VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b0);
+ if (PREDICT_FALSE (n_trace > 0))
+ {
+ session_queue_trace_t *t0;
+ vlib_trace_buffer (vm, node, next_index, b0,
+ 1 /* follow_chain */ );
+ vlib_set_trace_count (vm, node, --n_trace);
+ t0 = vlib_add_trace (vm, node, b0, sizeof (*t0));
+ t0->session_index = s0->session_index;
+ t0->server_thread_index = s0->thread_index;
+ }
+
vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
to_next, n_left_to_next,
bi0, next0);
diff --git a/src/vnet/session/session.c b/src/vnet/session/session.c
index e92bb440601..6e129dde018 100644
--- a/src/vnet/session/session.c
+++ b/src/vnet/session/session.c
@@ -432,33 +432,97 @@ stream_session_create_i (segment_manager_t * sm, transport_connection_t * tc,
return 0;
}
+/** Enqueue buffer chain tail */
+always_inline int
+session_enqueue_chain_tail (stream_session_t * s, vlib_buffer_t * b,
+ u32 offset, u8 is_in_order)
+{
+ vlib_buffer_t *chain_b;
+ u32 chain_bi = b->next_buffer;
+ vlib_main_t *vm = vlib_get_main ();
+ u8 *data, len;
+ u16 written = 0;
+ int rv = 0;
+
+ do
+ {
+ chain_b = vlib_get_buffer (vm, chain_bi);
+ data = vlib_buffer_get_current (chain_b);
+ len = chain_b->current_length;
+ if (is_in_order)
+ {
+ rv = svm_fifo_enqueue_nowait (s->server_rx_fifo, len, data);
+ if (rv < len)
+ {
+ return (rv > 0) ? (written + rv) : written;
+ }
+ written += rv;
+ }
+ else
+ {
+ rv = svm_fifo_enqueue_with_offset (s->server_rx_fifo, offset, len,
+ data);
+ if (rv)
+ return -1;
+ offset += len;
+ }
+ }
+ while ((chain_bi = (chain_b->flags & VLIB_BUFFER_NEXT_PRESENT)
+ ? chain_b->next_buffer : 0));
+
+ if (is_in_order)
+ return written;
+
+ return 0;
+}
+
/*
* Enqueue data for delivery to session peer. Does not notify peer of enqueue
* event but on request can queue notification events for later delivery by
* calling stream_server_flush_enqueue_events().
*
* @param tc Transport connection which is to be enqueued data
- * @param data Data to be enqueued
- * @param len Length of data to be enqueued
+ * @param b Buffer to be enqueued
+ * @param offset Offset at which to start enqueueing if out-of-order
* @param queue_event Flag to indicate if peer is to be notified or if event
* is to be queued. The former is useful when more data is
* enqueued and only one event is to be generated.
+ * @param is_in_order Flag to indicate if data is in order
* @return Number of bytes enqueued or a negative value if enqueueing failed.
*/
int
-stream_session_enqueue_data (transport_connection_t * tc, u8 * data, u16 len,
- u8 queue_event)
+stream_session_enqueue_data (transport_connection_t * tc, vlib_buffer_t * b,
+ u32 offset, u8 queue_event, u8 is_in_order)
{
stream_session_t *s;
- int enqueued;
+ int enqueued = 0, rv;
s = stream_session_get (tc->s_index, tc->thread_index);
- /* Make sure there's enough space left. We might've filled the pipes */
- if (PREDICT_FALSE (len > svm_fifo_max_enqueue (s->server_rx_fifo)))
- return -1;
-
- enqueued = svm_fifo_enqueue_nowait (s->server_rx_fifo, len, data);
+ if (is_in_order)
+ {
+ enqueued =
+ svm_fifo_enqueue_nowait (s->server_rx_fifo, b->current_length,
+ vlib_buffer_get_current (b));
+ if (PREDICT_FALSE
+ ((b->flags & VLIB_BUFFER_NEXT_PRESENT) && enqueued > 0))
+ {
+ rv = session_enqueue_chain_tail (s, b, 0, 1);
+ if (rv <= 0)
+ return enqueued;
+ enqueued += rv;
+ }
+ }
+ else
+ {
+ rv = svm_fifo_enqueue_with_offset (s->server_rx_fifo, offset,
+ b->current_length,
+ vlib_buffer_get_current (b));
+ if (PREDICT_FALSE ((b->flags & VLIB_BUFFER_NEXT_PRESENT) && !rv))
+ rv = session_enqueue_chain_tail (s, b, offset + b->current_length, 0);
+ if (rv)
+ return -1;
+ }
if (queue_event)
{
@@ -476,7 +540,10 @@ stream_session_enqueue_data (transport_connection_t * tc, u8 * data, u16 len,
}
}
- return enqueued;
+ if (is_in_order)
+ return enqueued;
+
+ return 0;
}
/** Check if we have space in rx fifo to push more bytes */
diff --git a/src/vnet/session/session.h b/src/vnet/session/session.h
index f41a8a96eb5..f152a2be0e2 100644
--- a/src/vnet/session/session.h
+++ b/src/vnet/session/session.h
@@ -345,8 +345,8 @@ stream_session_fifo_size (transport_connection_t * tc)
}
int
-stream_session_enqueue_data (transport_connection_t * tc, u8 * data, u16 len,
- u8 queue_event);
+stream_session_enqueue_data (transport_connection_t * tc, vlib_buffer_t * b,
+ u32 offset, u8 queue_event, u8 is_in_order);
u32
stream_session_peek_bytes (transport_connection_t * tc, u8 * buffer,
u32 offset, u32 max_bytes);
diff --git a/src/vnet/tcp/tcp_input.c b/src/vnet/tcp/tcp_input.c
index d268251cb38..ceb00fc3e41 100644
--- a/src/vnet/tcp/tcp_input.c
+++ b/src/vnet/tcp/tcp_input.c
@@ -993,9 +993,8 @@ tcp_session_enqueue_data (tcp_connection_t * tc, vlib_buffer_t * b,
return TCP_ERROR_PURE_ACK;
}
- written = stream_session_enqueue_data (&tc->connection,
- vlib_buffer_get_current (b),
- data_len, 1 /* queue event */ );
+ written = stream_session_enqueue_data (&tc->connection, b, 0,
+ 1 /* queue event */ , 1);
TCP_EVT_DBG (TCP_EVT_INPUT, tc, 0, data_len, written);
@@ -1053,12 +1052,10 @@ tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
return TCP_ERROR_PURE_ACK;
}
- s0 = stream_session_get (tc->c_s_index, tc->c_thread_index);
-
/* Enqueue out-of-order data with absolute offset */
- rv = svm_fifo_enqueue_with_offset (s0->server_rx_fifo,
- vnet_buffer (b)->tcp.seq_number,
- data_len, vlib_buffer_get_current (b));
+ rv = stream_session_enqueue_data (&tc->connection, b,
+ vnet_buffer (b)->tcp.seq_number,
+ 0 /* queue event */ , 0);
/* Nothing written */
if (rv)
@@ -1075,6 +1072,8 @@ tcp_session_enqueue_ooo (tcp_connection_t * tc, vlib_buffer_t * b,
ooo_segment_t *newest;
u32 start, end;
+ s0 = stream_session_get (tc->c_s_index, tc->c_thread_index);
+
/* Get the newest segment from the fifo */
newest = svm_fifo_newest_ooo_segment (s0->server_rx_fifo);
start = ooo_segment_offset (s0->server_rx_fifo, newest);
@@ -2543,6 +2542,7 @@ do { \
_(FIN_WAIT_1, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
/* FIN confirming that the peer (app) has closed */
_(FIN_WAIT_2, TCP_FLAG_FIN, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
+ _(FIN_WAIT_2, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
_(FIN_WAIT_2, TCP_FLAG_FIN | TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS,
TCP_ERROR_NONE);
_(LAST_ACK, TCP_FLAG_ACK, TCP_INPUT_NEXT_RCV_PROCESS, TCP_ERROR_NONE);
diff --git a/src/vnet/tcp/tcp_output.c b/src/vnet/tcp/tcp_output.c
index 2a1b140750c..33e599ece32 100644
--- a/src/vnet/tcp/tcp_output.c
+++ b/src/vnet/tcp/tcp_output.c
@@ -46,7 +46,7 @@ typedef struct
tcp_connection_t tcp_connection;
} tcp_tx_trace_t;
-u16 dummy_mtu = 400;
+u16 dummy_mtu = 1460;
u8 *
format_tcp_tx_trace (u8 * s, va_list * args)
@@ -923,7 +923,7 @@ tcp_push_hdr_i (tcp_connection_t * tc, vlib_buffer_t * b,
u8 tcp_hdr_opts_len, opts_write_len, flags;
tcp_header_t *th;
- data_len = b->current_length;
+ data_len = b->current_length + b->total_length_not_including_first_buffer;
vnet_buffer (b)->tcp.flags = 0;
if (compute_opts)