Mirrors_Framework/nuttx
1
0
Fork 0
mirror of https://github.com/apache/nuttx.git synced 2025-12-14 07:25:51 +08:00
Code Issues Actions 1 Packages Projects Releases Wiki Activity

net/tcp: add Selective-ACK support

Browse Source 
Reference:
https://datatracker.ietf.org/doc/html/rfc2018

Iperf2 client/server test on esp32c3:

Drop(1/50):
CONFIG_NET_TCP_DEBUG_DROP_SEND=y
CONFIG_NET_TCP_DEBUG_DROP_SEND_PROBABILITY=50  // Drop probability: 1/50
CONFIG_NET_TCP_DEBUG_DROP_RECV=y
CONFIG_NET_TCP_DEBUG_DROP_RECV_PROBABILITY=50  // Drop probability: 1/50

Drop(1/50) + OFO/SACK:
CONFIG_NET_TCP_DEBUG_DROP_SEND=y
CONFIG_NET_TCP_DEBUG_DROP_SEND_PROBABILITY=50  // Drop probability: 1/50
CONFIG_NET_TCP_DEBUG_DROP_RECV=y
CONFIG_NET_TCP_DEBUG_DROP_RECV_PROBABILITY=50  // Drop probability: 1/50

CONFIG_NET_TCP_OUT_OF_ORDER=y
CONFIG_NET_TCP_SELECTIVE_ACK=y

---------------------------------------------------------
|  TCP Config            | Server | Client |            |
|-------------------------------------------------------|
|  Original              |   12   |     9  |  Mbits/sec |
|  Drop(1/50)            |  0.6   |   0.3  |  Mbits/sec |
|  Drop(1/50) + OFO/SACK |    8   |     8  |  Mbits/sec |
---------------------------------------------------------

Signed-off-by: chao an <anchao@xiaomi.com>
This commit is contained in:
chao an
2023-01-10 13:41:02 +08:00
committed by Xiang Xiao
parent c581cc5f9b
commit 64dd7e6376
6 changed files with 392 additions and 128 deletions
Download Patch File Download Diff File Expand all files Collapse all files

318
net/tcp/tcp_send_buffered.c
View File

@@ -170,6 +170,80 @@ static void psock_writebuffer_notify(FAR struct tcp_conn_s *conn)
# define psock_writebuffer_notify(conn)
#endif
static void retransmit_segment(FAR struct tcp_conn_s *conn,
FAR struct tcp_wrbuffer_s *wrb)
{
uint16_t sent;
/* Reset the number of bytes sent sent from the write buffer */
sent = TCP_WBSENT(wrb);
if (conn->tx_unacked > sent)
{
conn->tx_unacked -= sent;
}
else
{
conn->tx_unacked = 0;
}
if (conn->sent > sent)
{
conn->sent -= sent;
}
else
{
conn->sent = 0;
}
TCP_WBSENT(wrb) = 0;
ninfo("REXMIT: wrb=%p sent=%u, "
"conn tx_unacked=%" PRId32 " sent=%" PRId32 "\n",
wrb, TCP_WBSENT(wrb), conn->tx_unacked, conn->sent);
/* Free any write buffers that have exceed the retry count */
if (++TCP_WBNRTX(wrb) >= TCP_MAXRTX)
{
nwarn("WARNING: Expiring wrb=%p nrtx=%u\n",
wrb, TCP_WBNRTX(wrb));
/* Return the write buffer to the free list */
tcp_wrbuffer_release(wrb);
/* Notify any waiters if the write buffers have been
* drained.
*/
psock_writebuffer_notify(conn);
/* NOTE expired is different from un-ACKed, it is designed
* to represent the number of segments that have been sent,
* retransmitted, and un-ACKed, if expired is not zero, the
* connection will be closed.
*
* field expired can only be updated at TCP_ESTABLISHED
* state
*/
conn->expired++;
}
else
{
/* Insert the write buffer into the write_q (in sequence
* number order). The retransmission will occur below
* when the write buffer with the lowest sequence number
* is pulled from the write_q again.
*/
ninfo("REXMIT: Moving wrb=%p nrtx=%u\n",
wrb, TCP_WBNRTX(wrb));
psock_insert_segment(wrb, &conn->write_q);
}
}
/****************************************************************************
* Name: psock_lost_connection
*
@@ -285,6 +359,97 @@ static inline void send_ipselect(FAR struct net_driver_s *dev,
}
#endif
/****************************************************************************
* Name: parse_sack
*
* Description:
* Parse sack from incoming TCP options
*
* Input Parameters:
* conn - The TCP connection of interest
* tcp - Header of tcp structure
* segs - Segments edge of sacks
*
* Returned Value:
* Number of sacks
*
* Assumptions:
* The network is locked.
*
****************************************************************************/
#ifdef CONFIG_NET_TCP_SELECTIVE_ACK
static int parse_sack(FAR struct tcp_conn_s *conn, FAR struct tcp_hdr_s *tcp,
FAR struct tcp_ofoseg_s *segs)
{
FAR struct tcp_sack_s *sacks;
int nsack = 0;
uint8_t opt;
int i;
/* Get the size of the link layer header,
* the IP and TCP header
*/
for (i = 0; i < ((tcp->tcpoffset >> 4) - 5) << 2 ; )
{
opt = *(tcp->optdata + i);
if (opt == TCP_OPT_END)
{
/* End of options. */
break;
}
else if (opt == TCP_OPT_NOOP)
{
/* NOP option. */
++i;
continue;
}
else if (opt == TCP_OPT_SACK)
{
nsack = (*(tcp->optdata + 1 + i) -
TCP_OPT_SACK_PERM_LEN) /
(sizeof(uint32_t) * 2);
sacks = (FAR struct tcp_sack_s *)
(tcp->optdata + i +
TCP_OPT_SACK_PERM_LEN);
for (i = 0; i < nsack; i++)
{
segs[i].left = tcp_getsequence((uint8_t *)&sacks[i].left);
segs[i].right = tcp_getsequence((uint8_t *)&sacks[i].right);
}
tcp_reorder_ofosegs(nsack, segs);
break;
}
else
{
/* All other options have a length field,
* so that we easily can skip past them.
*/
if (*(tcp->optdata + 1 + i) == 0)
{
/* If the length field is zero,
* the options are malformed and
* we don't process them further.
*/
break;
}
}
i += *(tcp->optdata + 1 + i);
}
return nsack;
}
#endif /* CONFIG_NET_TCP_SELECTIVE_ACK */
/****************************************************************************
* Name: psock_send_eventhandler
*
@@ -309,6 +474,10 @@ static uint16_t psock_send_eventhandler(FAR struct net_driver_s *dev,
FAR void *pvpriv, uint16_t flags)
{
FAR struct tcp_conn_s *conn = pvpriv;
#ifdef CONFIG_NET_TCP_SELECTIVE_ACK
struct tcp_ofoseg_s ofosegs[TCP_SACK_RANGES_MAX];
uint8_t nsacks = 0;
#endif
#ifdef CONFIG_NET_TCP_FAST_RETRANSMIT
uint32_t rexmitno = 0;
#endif
@@ -458,7 +627,6 @@ static uint16_t psock_send_eventhandler(FAR struct net_driver_s *dev,
wrb, TCP_WBSEQNO(wrb), TCP_WBPKTLEN(wrb));
}
}
#ifdef CONFIG_NET_TCP_FAST_RETRANSMIT
else if (ackno == TCP_WBSEQNO(wrb))
{
/* Reset the duplicate ack counter */
@@ -472,16 +640,33 @@ static uint16_t psock_send_eventhandler(FAR struct net_driver_s *dev,
if (++TCP_WBNACK(wrb) == TCP_FAST_RETRANSMISSION_THRESH)
{
/* Do fast retransmit */
#ifdef CONFIG_NET_TCP_SELECTIVE_ACK
if ((conn->flags & TCP_SACK) &&
(tcp->tcpoffset & 0xf0) > 0x50)
{
/* Parse s-ack from tcp options */
rexmitno = ackno;
nsacks = parse_sack(conn, tcp, ofosegs);
/* Reset counter */
flags |= TCP_REXMIT;
}
#ifdef CONFIG_NET_TCP_FAST_RETRANSMIT
else
#endif
#endif
{
#ifdef CONFIG_NET_TCP_FAST_RETRANSMIT
/* Do fast retransmit */
TCP_WBNACK(wrb) = 0;
rexmitno = ackno;
#endif
/* Reset counter */
TCP_WBNACK(wrb) = 0;
}
}
}
#endif
}
/* A special case is the head of the write_q which may be partially
@@ -613,6 +798,57 @@ static uint16_t psock_send_eventhandler(FAR struct net_driver_s *dev,
}
#endif
#ifdef CONFIG_NET_TCP_SELECTIVE_ACK
/* Check if we are being asked to retransmit s-ack data */
if (nsacks > 0)
{
FAR struct tcp_wrbuffer_s *wrb;
FAR sq_entry_t *entry;
FAR sq_entry_t *next;
uint32_t right;
int i;
/* Dump s-ack edge */
for (i = 0, right = 0; i < nsacks; i++)
{
ninfo("TCP SACK [%d]"
"[%" PRIu32 " : %" PRIu32 " : %" PRIu32 "]\n",
i, ofosegs[i].left, ofosegs[i].right,
TCP_SEQ_SUB(ofosegs[i].right, ofosegs[i].left));
}
for (entry = sq_peek(&conn->unacked_q); entry; entry = next)
{
wrb = (FAR struct tcp_wrbuffer_s *)entry;
next = sq_next(entry);
for (i = 0, right = 0; i < nsacks; i++)
{
/* Wrb seqno out of s-ack edge ? do retransmit ! */
if (TCP_SEQ_LT(TCP_WBSEQNO(wrb), ofosegs[i].left) &&
TCP_SEQ_GTE(TCP_WBSEQNO(wrb), right))
{
ninfo("TCP REXMIT "
"[%" PRIu32 " : %" PRIu32 " : %d]\n",
TCP_WBSEQNO(wrb),
TCP_SEQ_ADD(TCP_WBSEQNO(wrb), TCP_WBPKTLEN(wrb)),
TCP_WBPKTLEN(wrb));
sq_rem(entry, &conn->unacked_q);
retransmit_segment(conn, (FAR void *)entry);
break;
}
right = ofosegs[i].right;
}
}
}
else
#endif
/* Check if we are being asked to retransmit data */
if ((flags & TCP_REXMIT) != 0)
@@ -706,75 +942,7 @@ static uint16_t psock_send_eventhandler(FAR struct net_driver_s *dev,
while ((entry = sq_remlast(&conn->unacked_q)) != NULL)
{
wrb = (FAR struct tcp_wrbuffer_s *)entry;
uint16_t sent;
/* Reset the number of bytes sent sent from the write buffer */
sent = TCP_WBSENT(wrb);
if (conn->tx_unacked > sent)
{
conn->tx_unacked -= sent;
}
else
{
conn->tx_unacked = 0;
}
if (conn->sent > sent)
{
conn->sent -= sent;
}
else
{
conn->sent = 0;
}
TCP_WBSENT(wrb) = 0;
ninfo("REXMIT: wrb=%p sent=%u, "
"conn tx_unacked=%" PRId32 " sent=%" PRId32 "\n",
wrb, TCP_WBSENT(wrb), conn->tx_unacked, conn->sent);
/* Free any write buffers that have exceed the retry count */
if (++TCP_WBNRTX(wrb) >= TCP_MAXRTX)
{
nwarn("WARNING: Expiring wrb=%p nrtx=%u\n",
wrb, TCP_WBNRTX(wrb));
/* Return the write buffer to the free list */
tcp_wrbuffer_release(wrb);
/* Notify any waiters if the write buffers have been
* drained.
*/
psock_writebuffer_notify(conn);
/* NOTE expired is different from un-ACKed, it is designed to
* represent the number of segments that have been sent,
* retransmitted, and un-ACKed, if expired is not zero, the
* connection will be closed.
*
* field expired can only be updated at TCP_ESTABLISHED state
*/
conn->expired++;
continue;
}
else
{
/* Insert the write buffer into the write_q (in sequence
* number order). The retransmission will occur below
* when the write buffer with the lowest sequence number
* is pulled from the write_q again.
*/
ninfo("REXMIT: Moving wrb=%p nrtx=%u\n", wrb, TCP_WBNRTX(wrb));
psock_insert_segment(wrb, &conn->write_q);
}
retransmit_segment(conn, (FAR void *)entry);
}
}