Add a generic function for TCP option parsing. So far we're
interested only in MSS option value, so that's what it handles.
Use it to parse MSS value in net_context incoming SYN packet
handler.
Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
MSS is Maximum Segment Size (data payload) of TCP. In SYN packets,
each side of the connection shares an MSS it wants to use (receive)
via the corresponding TCP option. If the option is not available,
the RFC mandates use of the value 536.
This patch handles storage of the send MSS (in the TCP structure,
in TCP backlog), with follow up patch handling actual parsing it
from the SYN TCP options.
Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
The expire function can call net_context_unref() which tries to
get a semaphore with K_FOREVER. This is not allowed in interrupt
context. To overcome this, run the expire functionality from
system work queue instead.
Fixes#4683
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Add option to set initial Retransmission Timeout value. The value is
different from NET_TCP_ACK_TIMEOUT since latter affects TCP states
timeout when waiting for ACK for example.
Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
There were decrements of TCP sequence numbers, inherited from FNET
stack implementation, as was used as an initial base. RFC793 does
not specify conditions for decrementing sequence numbers, so such
decrements are an artifact of FNET implementation. In Zephyr code,
we had to compensate for these decrements by extra increments
(including an increment-by-2). So, remove decrements and associated
extra increments to simplify the code.
Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
If the caller has passed net_pkt to prepare_segment(), then
it is caller responsibility to unref it in a case of error.
Fixes#4292
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Instead of hard coded 1280 bytes MSS, use the MTU of the link
for MSS. The minimal MSS is still 1280 which is mandated by
IPv6 RFC.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
This reverts commit 817245c564.
In certain cases the peer seems to discard the FIN packet we are
sending, which means that the TCP stream is not closed properly.
This needs more work so revert this for time being.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
If network context is closed, send FIN by placing it to the end
of send queue instead of sending it immediately. This way all
pending data is sent before the connection is closed.
Jira: ZEP-1853
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
This is very unlikely to happen but the device will access null
pointer if we do not properly check the return value of header
check function.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Using memcpy() to copy net_pkt is not safe because there are
pointers inside. So use the new net_pkt_clone() to do that.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
k_delayed_work_cancel now only fail if it hasn't been submitted which
means it is not in use anyway so it safe to reset its data regardless
of its return.
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
If we are not in ESTABLISHED state, then there is no need to
try to resend any pending data packets.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
If the expire send timer expires, then it sends the packet.
If that happens, then we must not try to send the same packet
again if we receive ACK etc. which can cause re-sends to happen.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
If the packet sending is slow then we must NOT increment the ref
count when re-sending it. This is unlikely but can happen if there
are lot of debug prints etc. extra activities that prevent the driver
to actually send the packet fast enough.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Make sure that the sent flag is only set after we have really
sent the packet and the driver has verified that.
If the net_pkt_set_sent() is called while still in tcp.c, then
depending on how fast the device is, it might happen that the
retry timer expires before the packet is actually sent. This was
seen in frdm-k64f with ethernet and various debug prints activated.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
The second 'const' is misguided, indicating that the returns pointer
value itself cannot be changed, but since pointers are passed by value
anyway this is not useful and was generating warnings with XCC.
The leading 'const' indicates that the memory pointed to is constant,
which is all we needed.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This is needed in order to get information which function is
doing the ref. With inline function this was not possible.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
The API name space for Bluetooth is bt_* and BT_* so it makes sense to
align the Kconfig name space with this. The additional benefit is that
this also makes the names shorter. It is also in line with what Linux
uses for Bluetooth Kconfig entries.
Some Bluetooth-related Networking Kconfig defines are renamed as well
in order to be consistent, such as NET_L2_BLUETOOTH.
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
This fixes the existing situation that "if application buffers data,
it's the problem of application". It's actually the problem of the
stack, as it doesn't allow application to control receive window,
and without this control, any buffer will overflow, peer packets
will be dropped, peer won't receive acks for them, and will employ
exponential backoff, the connection will crawl to a halt.
This patch adds net_context_tcp_recved() function which an
application must explicitly call when it *processes* data, to
advance receive window.
Jira: ZEP-1999
Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
For IPv6 header compressed packet, the IP header offsets will
be wrong. In this case there is no need to print error when
trying to print TCP packet information.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
The sequence number validator was checking the seq numbers
incorrectly. This caused some valid RST packets to be dropped
and the TCP stream to hang.
Added also a TCP test case that tests the seq validator.
Jira: ZEP-2289
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
The commit 210c30805b ("net: context: Close connection fast
if TIME_WAIT support is off") was not a proper way of closing
the connection. So if Zephyr closes the connection (active close),
then send FIN and install a timer that makes sure that if the peer
FIN + ACK is lost, we close the connection properly after a timeout.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
The commit 00ac0487b0 ("net: context: Remove tcp struct SYN-ACK
timer handling") removed also the passive close ACK timer.
Adding that ACK timer back so that we can close the connection
properly even if the last ACK from peer is lost.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
If the TCP data packet needs to be re-sent after the packet is lost,
then the acknowledgment number will be changed. This then means that
the TCP checksum needs to be recalculated too.
Signed-off-by: june li <junelizh@foxmail.com>
Remove NET_TCP_HDR() macro as we cannot safely access TCP header
via it if the network packet header spans over multiple net_buf
fragments.
Fixed also the TCP unit tests so that they pass correctly.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Instead of waiting forever for a free net_buf, set a timeout to
the allocations (500 ms). This way the application will not be
blocked by memory exhaustion.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Defines a new tunable, CONFIG_NET_TCP_RETRY_COUNT, that determines the
number of segment retransmissions that the IP stack will attempt to
perform before resetting the connection.
The default value is 9 retransmissions, which amounts to 1:42 minutes,
as close as possible to the minimum recommended by RFC1122.
Jira: ZEP-1956, ZEP-1957
Signed-off-by: Leandro Pereira <leandro.pereira@intel.com>
Without change to add ACK to FIN, invalid TCP packet is generated,
where ack sequence number is non-zero. Without adjusting sequence
number as done, ACK which we send in response to peer's FIN/ACK is
not recognized by peer, and peer keeps retransmitting its FIN/ACK.
Jira: ZEP-2104
Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
We must check if we receive RST in any of the TCP states.
If we do not do this, then the net_context might leak as it
would never be released in some of the states. Receiving RST
in any TCP state is not described in TCP state diagram but is
described in RFC 793 which says in chapter "Reset Processing"
that system "...aborts the connection and advises the user and
goes to the CLOSED state."
We need to also validate the received RST and accept only those
TCP reset packets that contain valid sequence number.
The validate_state_transitions() function is also changed to
accept CLOSED state transition from various other states.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
RFC793, "Transmission Control Protocol", defines sequence numbers
just as 32-bit numbers without a sign. It doesn't specify any adhoc
rules for comparing them, so standard modular arithmetic should be
used.
Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>
This is related to commit "net: tcp: Make sure ACK timer is not
run if cancelled" which did not set the cancel flag when the timer
was cancelled from tcp.c.
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
The TCP trace values were not printed because of incorrect
config option used. Print also seq and ack values in decimal
in order to make it easier to correlate the values in other
prints in tcp.c.
Change-Id: I44d1535a84dcba8c6c937d348516ba801193ca23
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Convert code to use u{8,16,32,64}_t and s{8,16,32,64}_t instead of C99
integer types.
Jira: ZEP-2051
Change-Id: I4ec03eb2183d59ef86ea2c20d956e5d272656837
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
If TCP debugging is enabled but if the loglevel is set to lower
than 4, then compiler prints warning about unused flags variable
in net_tcp_trace().
Change-Id: I2e663644b50fe97b75088202e21b286aa010953e
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
Most of these macros are not exactly exposing a buffer, but a specific
header pointer (ipv6, ivp4, ethernet and so on), so it relevant to
rename them accordingly.
Change-Id: I66e32f7c3f2bc75994befb28d823e24299a53f5c
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
- net_pkt becomes a stand-alone structure with network packet meta
information.
- network packet data is still managed through net_buf, mostly named
'frag'.
- net_pkt memory management is done through k_mem_slab
- function got introduced or relevantly renamed to target eithe net_pkt
or net_buf fragments.
- net_buf's sent_list ends up in net_pkt now, and thus helps to save
memory when TCP is enabled.
Change-Id: Ibd5c17df4f75891dec79db723a4c9fc704eb843d
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
There have been long lasting confusion between net_buf and net_nbuf.
While the first is actually a buffer, the second one is not. It's a
network buffer descriptor. More precisely it provides meta data about a
network packet, and holds the chain of buffer fragments made of net_buf.
Thus renaming net_nbuf to net_pkt and all names around it as well
(function, Kconfig option, ..).
Though net_pkt if the new name, it still inherit its logic from net_buf.
'
This patch is the first of a serie that will separate completely net_pkt
from net_buf.
Change-Id: Iecb32d2a0d8f4647692e5328e54b5c35454194cd
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
We need to check whether buf_sent was true when resending the TCP
segment, and do a buf ref if needed. If this is not done, the buf
will be unref after send, which will cause unpredictable results.
Change-Id: Ibd4490305de88ac6ffd04ec42bba196e57da5c10
Signed-off-by: june li <junelizh@foxmail.com>
After failing to send the buf we need to release it.
This is not done for Bluetooth or IEEE 802.15.4 links which
create a copy of the sent buf and the failure case is already
checked by net_tcp_send_buf().
Change-Id: Ia556376b58ad74f68accb64eb2221a78d59dc2ec
Signed-off-by: june li <junelizh@foxmail.com>
Use UNALIGNED_PUT() to store the MSS value into network packet
because the memory location cannot be guaranteed to be properly
aligned.
Change-Id: I77fd7a70ef45eedb657cac29457b0239b0a1d4c2
Signed-off-by: Jukka Rissanen <jukka.rissanen@linux.intel.com>
When sending TCP data, check if the retry timer needs
to be started.
Change-Id: Iea90716e918dec0b22e60bf32467b11c0d1a296f
Signed-off-by: june li <junelizh@foxmail.com>
