* Do not accept the window in old segments.
Implement SND.WL1/WL2 things in the RFC.
* Do not accept the window in the segment w/o ACK bit set.
The window is an offset from the ack seq.
(maybe it's simpler to just drop segments w/o ACK though)
* Subtract snd_wnd by the amount of the ack advancement.
Fix a wrong assertion in:
```
commit 98ec46d726
Author: YAMAMOTO Takashi <yamamoto@midokura.com>
Date: Tue Jul 20 09:10:43 2021 +0900
tcp_send_buffered.c: fix iob allocation deadlock
Ensure to put the wrb back onto the write_q when blocking
on iob allocation. Otherwise, it can deadlock with other
threads doing the same thing.
```
I forget to submit this with https://github.com/apache/incubator-nuttx/pull/4257
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.
Consider a bi-directional TCP connection:
1. we use all IOBs for tx queue
2. we advertize zero recv window because we have no free IOBs
3. if the peer tcp does the same thing,
both sides advertize zero window and can not drain the tx queue.
For a similar stall to happen, the peer doesn't need to be
a naive tcp implementation like nuttx. A naive application blocking
on send() without draining its read buffer is enough.
(Probably such an application should be fixed to drain rx even
when tx is full. However, it's another story.)
This commit avoids the situation by prevent tx from grabbing
the all IOBs in the first place. (assuming CONFIG_IOB_THROTTLE > 0)
Since we do not have the Nagle's algorithm,
the TCP_NODELAY socket option is enabled by default.
Change-Id: I0c8619bb06cf418f7eded5bd72ac512b349cacc5
Signed-off-by: chao.an <anchao@xiaomi.com>
Since a SOL option IP_TTL exist, we should rename this IP_TTL
in netconfig.h to avoid confusion.
Signed-off-by: Huang Qi <huangqi3@xiaomi.com>
Change-Id: Ib04c36553f23bce8d362e97294a8b83eaa050cf3
quote from https://man7.org/linux/man-pages/man2/sendfile.2.html:
If offset is not NULL, then it points to a variable holding the
file offset from which sendfile() will start reading data from
in_fd. When sendfile() returns, this variable will be set to the
offset of the byte following the last byte that was read. If
offset is not NULL, then sendfile() does not modify the file
offset of in_fd; otherwise the file offset is adjusted to reflect
the number of bytes read from in_fd.
If offset is NULL, then data will be read from in_fd starting at
the file offset, and the file offset will be updated by the call.
The change also align with the implementation at:
libs/libc/misc/lib_sendfile.c
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>
Change-Id: I607944f40b04f76731af7b205dcd319b0637fa04
1. change all window relative value type to uint32_t
2. move window range validity check(UINT16_MAX) before assembling TCP header
Signed-off-by: chao.an <anchao@xiaomi.com>
Reason:
When user call rpmsg_socket_close() at the same time
rpmsg_socket_ns_unbind() is called by remote CPU,
then will meet multi-access to rpmsg_socket_device_destroy()
Fix:
reuse recvlock to handle this
Change-Id: I8f33658f19c56a4000382ff9355ff052c45afea0
Signed-off-by: ligd <liguiding1@xiaomi.com>
tcp_close disposes the connection immediately if it's called in
TCP_LAST_ACK. If it happens, we will end up with responding the
last ACK with a RST.
This commit fixes it by making tcp_close wait for the completion
of the passive close.
This fixes connection closing issues with CONFIG_NET_TCP_WRITE_BUFFERS.
Because TCP_CLOSE is used for both of input and output for tcp_callback,
the close callback and the send callback confuses each other as
the following. As it effectively disposes the connection immediately,
we end up with responding to the consequent ACK and FIN/ACK from the peer
with RSTs.
tcp_timer
-> tcp_close_eventhandler
returns TCP_CLOSE (meaning an active close)
-> psock_send_eventhandler
called with TCP_CLOSE from tcp_close_eventhandler, misinterpet as
a passive close.
-> tcp_lost_connection
-> tcp_shutdown_monitor
-> tcp_callback
-> tcp_close_eventhandler
misinterpret TCP_CLOSE from itself as
a passive close
The current code just leave the window value from the segment
from the peer. It doesn't make sense.
Instead, always use 0.
This matches what NetBSD and Linux do.
(As far as I read their code correctly.)
* It doesn't make sense to have this conditional on our own
SO_KEEPALIVE support. (CONFIG_NET_TCP_KEEPALIVE)
Actually we don't have a control on the peer tcp stack,
who decides to send us keep-alive probes.
* We should respond them for non ESTABLISHED states. eg. FIN_WAIT_2
See also:
https://github.com/apache/incubator-nuttx/pull/3919#issuecomment-868248576
Do not bother to preserve segment boundaries in the tcp
readahead queues.
* Avoid wasting the tail IOB space for each segments.
Instead, pack the newly received data into the tail space
of the last IOB. Also, advertise the tail space as
a part of the window.
* Use IOB chain directly. Eliminate IOB queue overhead.
* Allow to accept only a part of a segment.
* This change improves the memory efficiency.
And probably more importantly, allows less-confusing
recv window advertisement behavior.
Previously, even when we advertise N bytes window,
we often couldn't actually accept N bytes. Depending on
the segment sizes and IOB configurations, it was causing
segment drops.
Also, the previous code was moving the right edge of the
window back and forth too often, even when nothing in
the system was competing on the IOBs. Shrinking the
window that way is a kinda well known recipe to confuse
the peer stack.
* Move the code to advance rcvseq for user data from tcp_input
to receive handlers.
Motivation: allow partial ack.
* If we drop a segment, ignore FIN as well. Note than tcp FIN bit is
logically after the user data in the same segment.
I assume this was just an oversight because I couldn't
find any obvious reason to special-case only the first IOB.
The commit message of the original commit is cited below.
```
commit bf21056001
Author: chao.an <anchao@xiaomi.com>
Date: Fri Nov 27 09:50:38 2020 +0800
net/tcp: fallback to unthrottle pool to avoid deadlock
Add a fallback mechanism to ensure that there are still available
iobs for an free connection, Guarantees all connections will have
a minimum threshold iob to keep the connection not be hanged.
Change-Id: I59bed98d135ccd1f16264b9ccacdd1b0d91261de
Signed-off-by: chao.an <anchao@xiaomi.com>
```
* Fixes the case where the window was small but not zero.
* tcp_recvfrom: Remove tcp_ackhandler. Instead, simply schedule TX for
a possible window update and make tcp_appsend decide.
* Replace rcv_wnd (the last advertized window size value) with
rcv_adv. (the window edge sequence number advertized to the peer)
rcv_wnd was complicated to deal with because its base (rcvseq) is
also moving.
* tcp_appsend: Send a window update even if there are no other reasons
to send an ack.
Namely, send an update if it increases the window by
* 2 * mss
* or the half of the max possible window size
Gregory Nutt is the copyright holder for those files and he has submitted the
SGA as a result we can migrate the licenses to Apache.
Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
NuttX provides the UDP_BINDTODEVICE socket option. This is a UDP protocol-specific implementation of the semi-standard Linux SO_BINDTODEVICE socket option: "SO_BINDTODEVICE forces packets on the socket to only egress the bound interface, regardless of what the IP routing table would normally choose. Similarly only packets which ingress the bound interface will be received on the socket, packets from other interfaces will not be delivered to the socket." https://codingrelic.geekhold.com/2009/10/code-snippet-sobindtodevice.html
If CONFIG_NET_UDP_BINDTODEVICE is selected and a UDP socket is bound to the device, then unrecognized packets UDP packets must not be dropped, but must be forwarded along to the bound socket unconditionally.
It the typical case, this should have no impact. It does effect the applications that use DHCP and do select the UDP_BINDTODEVICE socket option.
This PR replace existing improper logic in the code and also the improper attempts to fix problems from PR #3601 and PR #3598. Those changes are improper because they expose DHCP appliction dependencies in the OS, breaking modularity and independence of the OS and application.
Tested with stm32f4discovery:netnsh with CONFIG_NET_UDP_BINDTODEVICE. A proper DHCP test setup is needed, however.
Several licenses were missed in the initial work
David Sidrane has submitted the ICLA and we can migrate the licenses
to Apache.
Gregory Nutt has submitted the SGA and we can migrate the licenses
to Apache.
Signed-off-by: Alin Jerpelea <alin.jerpelea@sony.com>
