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xiaoxiang pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/incubator-nuttx.git
The following commit(s) were added to refs/heads/master by this push:
new 1d3594b tcp_send_buffered.c: Fix broken retransmit
1d3594b is described below
commit 1d3594ba0791fe6e80cf3443f04f8d8fd0dcb503
Author: YAMAMOTO Takashi <[email protected]>
AuthorDate: Thu Jul 15 15:56:06 2021 +0900
tcp_send_buffered.c: Fix broken retransmit
With an applictation using mbedtls, I observed retransmitted segments
with corrupted user data, detected by the peer tls during mac processing.
Looking at the packet dump, I suspect that a wrb which has been put back
onto the write_q for retransmission was partially sent but fully acked.
Note: it's normal for a retransmission to be acked before sent.
In that case, the bug fixed in this commit would cause the wrb have
a wrong sequence number, possibly the same as the next wrb. It matches
what I saw in the packet dump. That is, the broken segments contain the
payload identical to one of the previous segment.
---
net/tcp/tcp_send_buffered.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/tcp/tcp_send_buffered.c b/net/tcp/tcp_send_buffered.c
index 239107e..1000097 100644
--- a/net/tcp/tcp_send_buffered.c
+++ b/net/tcp/tcp_send_buffered.c
@@ -506,7 +506,7 @@ static uint16_t psock_send_eventhandler(FAR struct
net_driver_s *dev,
ninfo("ACK: wrb=%p trim %u bytes\n", wrb, trimlen);
TCP_WBTRIM(wrb, trimlen);
- TCP_WBSEQNO(wrb) = ackno;
+ TCP_WBSEQNO(wrb) += trimlen;
TCP_WBSENT(wrb) -= trimlen;
/* Set the new sequence number for what remains */
@@ -571,7 +571,7 @@ static uint16_t psock_send_eventhandler(FAR struct
net_driver_s *dev,
/* Trim the ACKed bytes from the beginning of the write buffer. */
TCP_WBTRIM(wrb, nacked);
- TCP_WBSEQNO(wrb) = ackno;
+ TCP_WBSEQNO(wrb) += nacked;
TCP_WBSENT(wrb) -= nacked;
ninfo("ACK: wrb=%p seqno=%" PRIu32 " pktlen=%u sent=%u\n",
