tcp_recved: fix overflow check

Improved fix instead of patch #9699.

Signed-off-by: Simon Goldschmidt <goldsimon@gmx.de>

Revert "tcp_recved: check for overflow and warn about too big values"

This reverts commit ebb0dc14a7336c793d32c8e9ebde5bd9666f2a65.
It changes the behaviour to assert for applications running good so far.

Signed-off-by: Simon Goldschmidt <goldsimon@gmx.de>

Revert "tcp_abandon: no need to buffer pcb->local_port"

This reverts commit 1570dd8ad1c6afd2438dcb8b18d9eed794f78baa.

Buffering pcb->local_port is needed because TCP_PCB_REMOVE_ACTIVE()
sets it to 0 via tcp_pcb_remove() (comment: "reset the local port
to prevent the pcb from being 'bound'").

Signed-off-by: Simon Goldschmidt <goldsimon@gmx.de>

tcp_recved: check for overflow and warn about too big values

Apply patch #9694: Update prev pointer when skipping entries in tcp_slowtmr to prevent hitting assertion

fix bug #54315 (IPV6_V6ONLY socket accepts IPV4 connections)

Signed-off-by: Simon Goldschmidt <goldsimon@gmx.de>

tcp/udp bind: small code restructuring for IPv6-only

See bug #54229

tcp: fix RTO timer not working if link is down

... and added some test cases for this situation
See bug #54139

Signed-off-by: Simon Goldschmidt <goldsimon@gmx.de>

remove 2 NULL checks which are wrong

fix NULL checks (compiler error, tcp_rst allows pcb==NULL)

Add null pointer checks for TCP, UDP and netif

Signed-off-by: Simon Goldschmidt <goldsimon@gmx.de>

tcp: introduce ext_args per pcb

This introduces the concept of ext (external/extended) arguments per
tcp_pcb (also for listening pcbs) to store more data than just one
"void *arg" per pcb. The "arg" is for use to applications, whereas
the ext_args may be used by frameworks and leave "arg" untouched.

In addition to a void pointer, callbacks are added to help frameworks
migrate arguments from listen pcb to connection pcb and to free args
when the pcb is freed.

Signed-off-by: goldsimon <goldsimon@gmx.de>

tcp: centralize freeing tcp pcbs to memp_free

This should make it easier to add debugging messages or other hooks
to the point where tcp pcbs are deallocated.

Signed-off-by: goldsimon <goldsimon@gmx.de>

tcp_abandon: no need to buffer pcb->local_port

tcp: tiny doc update (mention tcp_output)

Work on task #14780: Add debug helper asserts to ensure threading/locking requirements are met
Add LWIP_ASSERT_CORE_LOCKED() in several places

... and fix DEBUG string

task #14600: tcp_alloc(): kill TF_CLOSEPEND connections before other ESTABLISHED

tcp: Remove superfluous variable in tcp_netif_ip_addr_changed()

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: goldsimon <goldsimon@gmx.de>

tcp_close_shutdown: always deallocate the pcb if there is unread data on close (see bug #52403)

We preserved the TIME_WAIT handling before, but it seems this is not correct: we want to issue
a RST later again if someone wants to talk to this port. With TIME_WAIT, this might not always
the case.

tcp: fix bug #36167 again (fixed in 2014, but when calling shutdown(WR) followed by recv(), this still happened)

Follow-up to patch #9472: tcp_kill_prio: Don't kill active connection that has the same priority
Correctly search for connection with lowest prio AND longest inactivity time

docs: small clean ups for last couple of commits:

* Fix typos in LWIP_NO_CTYPE_H comment block
* Update comment around caller of tcp_kill_prio()

Apply patch #9472: tcp_kill_prio: Don't kill active connection that has the same priority
in a modified, IMHO more readable way.

docs: update tcp_kill_prio same priority comments

tcp_kill_prio will kill the oldest active connection of same/lower
priority. Update all comments so that it's clear the same priority
can be killed

Move all rawapi.txt to appropriate doxygen docs

Remove raw API TCP/UDP function documentation from rawapi.txt - it is now integrated in doxygen docs.
This avoid having a second description for the same stuff that is "bit-rotting" because noone remembers to update this file.
Also remove outdated and misleading zero-copy TX information.

Improve UDP documentation using rawapi.txt texts

Improve lwIP doxygen documentation by copying several passages from rawapi.txt to the corresponding doxygen places

Improve lwIP doxygen documentation by copying several passages from rawapi.txt to the corresponding function documentation

Reformat core code using astylerc

Fix bug #51687 (tcp_close(): is it OK to return ERR_MEM if TF_CLOSEPEND is set?)

tcp: persist timer re-work (bug #50837)

This re-works the persist timer to have the following behavior:

1) Only start persist timer when a buffered segment doesn't fit within
the current window and there is no in-fligh data. Previously, the
persist timer was always started when the window went to zero even
if there was no buffered data (since timer was managed in receive
pathway rather than transmit pathway)
2) Upon first fire of persist timer, fill the remaining window if
non-zero by splitting the unsent segment. If split segment is sent,
persist timer is stopped, RTO timer is now ensuring reliable window
updates
3) If window is already zero when persist timer fires, send 1 byte probe
4) Persist timer and zero window probe should only be active when the
following are true:
* no in-flight data (pcb->unacked == NULL)
* when there is buffered data (pcb->unsent != NULL)
* when pcb->unsent->len > pcb->snd_wnd

tcp: use tcp_set_flags() rather than manually setting flag

tcp: use tcp_ack_now rather than manually setting TF_ACK_NOW

Continue fixing the spirit of bug #51663: don't change pcb state if retransmission can't be done because segments are still queued for transmission

- add a better-documented static function tcp_output_segment_busy
- try to reduce the number of checks
- tcp_rexmit_rto: iterate pcb->unacked only once
- no need to check for ref==1 in tcp_rexmit_fast when tcp_rexmit does
- call tcp_rexmit_fast if dupacks >= 3 (not == 3) and use TF_INFR flag to guard the fast-rexmit case (that way, it's triggered again on the next dupack)

tcp.c: Remove side-effects from boolean expressions

Fix "no previous prototype" warning when TCP_QUEUE_OOSEQ is disabled

work on -Wconversion...

Ensure SACKs are deleted when pbuf_free_ooseq() frees ooseq pbufs (because of memory shortage)

Cleaned up a bit after merging SACK_OUT support (mostly coding style)

Partial SACK (RFC 2018) support

Adds partial support for selective acknowledgements (RFC 2018).
This change makes lwIP negotiate SACK support, and include SACK
data in outgoing empty ACK packets. It does not include it
in outgoing packets with data payload.
It also does not add support for handling incoming SACKs.

Signed-off-by: goldsimon <goldsimon@gmx.de>

work on -Wconversion...

Use ip_addr_debug_print_val instead of ip_addr_debug_print where applicable

Initialize the tcp listen pcb netif_idx to NETIF_NO_INDEX.

Signed-off-by: goldsimon <goldsimon@gmx.de>

bug #50837: add zero-window probe timeout

This commit adds a timeout to the zero-window probing (persist timer)
mechanism. LwIP has not historically had a timeout for the persist
timer, leading to unbounded blocking if connection drops during the
zero-window condition

This commit also adds two units test, one to check the RTO timeout
and a second to check the zero-window probe timeout

tcp: Remove unreachable code in tcp_close_shutdown_fin

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Dirk Ziegelmeier <dirk@ziegelmeier.net>

tcp_fasttmr: adapt comment (to delayed FIN implementation)

Minor cleanup and documentation updates

Cleanup and simplify tcp_connect() code

Work on task #14494: Implement SO_BINDTODEVICE
TCP needs additional netif handling

Start working task #14494: Implement SO_BINDTODEVICE
Implement binding TCP, UDP and RAW PCBs to a netif

tcp: task #14128 - Appropriate Byte Counting support

This commit adds TCP Appropriate Byte Counting (ABC) support based on
RFC 3465

ABC replaces the previous congestion window growth mechanism and has been
configured with limit of 2 SMSS. See task #14128 for discussion on
defaults, but the goal is to mitigate the performance impact of delayed
ACKs on congestion window growth

This commit also introduces a mechanism to track when the stack is
undergoing a period following an RTO where data is being retransmitted.

Lastly, this adds a unit test to verify RTO period tracking and some
basic ABC cwnd checking

remove LWIP_RANDOMIZE_INITIAL_LOCAL_PORTS config option (this is implicitly done via #ifdef LWIP_RAND)

Improve TCP documentation a bit

altcp: added 'addrinfo' and 'tcp_state' functions

tcp: watch out for pcb->nrtx overflows and tcp_backoff indexing overflow

bug #50476: initialize ssthresh to TCP_SND_BUF

This commit changes ssthresh to be the largest effective congestion
window (amount of in-flight data). This follows the guidance of RFC
5681 which recommends setting ssthresh arbitrarily high.

LwIP was previously using the receive window value at the end of the
3-way handshake and in the case of an active open where the receiver
used window scaling and/or window auto-tuning, this resulted in a very
small ssthresh value even though the window ramped up once the connection
was established

tcp: fixed bug #50418: LWIP_EVENT_API: fix invalid calbacks for SYN_RCVD pcb

Fix comment typo from bug #47485

tcp_close_shutdown_impl() should be tcp_close_shutdown_fin()

Implement task #14367: Hooks need a better place to be defined
We now have a #define for a header file name that is #included in every .c file that provides hooks.

Fixed bug #47485 (tcp_close() should not fail on memory error) by retrying to send FIN from tcp_fasttmr

patch #9249: tcp: Fix unused parameter 'dest' build warning if !LWIP_IPV6
Apply modified version of Axel Lin's patch, without #ifdef

tcp: eliminate some redundant route lookups

Now that tcp_connect() always determines the outgoing netif with a
route lookup, we can compute the effective MSS without doing the same
route lookup again. The outgoing netif is already known from one
other location that computes the MSS, so we can eliminate a redundant
route lookup there too. Reduce some macro clutter as a side effect.

Add support for IPv6 address scopes

This patch adds full support for IPv6 address scopes, thereby aiming
to be compliant with IPv6 standards in general and RFC 4007 in
particular. The high-level summary is that link-local addresses are
now meaningful only in the context of their own link, guaranteeing
full isolation between links (and their addresses) in this respect.
This isolation even allows multiple interfaces to have the same
link-local addresses locally assigned.

The implementation achieves this by extending the lwIP IPv6 address
structure with a zone field that, for addresses that have a scope,
carries the scope's zone in which that address has meaning. The zone
maps to one or more interfaces. By default, lwIP uses a policy that
provides a 1:1 mapping between links and interfaces, and considers
all other addresses unscoped, corresponding to the default policy
sketched in RFC 4007 Sec. 6. The implementation allows for replacing
the default policy with a custom policy if desired, though.

The lwIP core implementation has been changed to provide somewhat of
a balance between correctness and efficiency on on side, and backward
compatibility on the other. In particular, while the application would
ideally always provide a zone for a scoped address, putting this in as
a requirement would likely break many applications. Instead, the API
accepts both "properly zoned" IPv6 addresses and addresses that, while
scoped, "lack" a zone. lwIP will try to add a zone as soon as possible
for efficiency reasons, in particular from TCP/UDP/RAW PCB bind and
connect calls, but this may fail, and sendto calls may bypass that
anyway. Ultimately, a zone is always added when an IP packet is sent
when needed, because the link-layer lwIP code (and ND6 in particualar)
requires that all addresses be properly zoned for correctness: for
example, to provide isolation between links in the ND6 destination
cache. All this applies to packet output only, because on packet
input, all scoped addresses will be given a zone automatically.

It is also worth remarking that on output, no attempt is made to stop
outgoing packets with addresses for a zone not matching the outgoing
interface. However, unless the application explicitly provides
addresses that will result in such zone violations, the core API
implementation (and the IPv6 routing algorithm in particular) itself
will never take decisions that result in zone violations itself.

This patch adds a new header file, ip6_zone.h, which contains comments
that explain several implementation aspects in a bit more detail.

For now, it is possible to disable scope support by changing the new
LWIP_IPV6_SCOPES configuration option. For users of the core API, it
is important to note that scoped addresses that are locally assigned
to a netif must always have a zone set; the standard netif address
assignment functions always do this on behalf of the caller, though.
Also, core API users will want to enable LWIP_IPV6_SCOPES_DEBUG at
least initially when upgrading, to ensure that all addresses are
properly initialized.

Fix bug #50206: UDP Netconn bind to IP6_ADDR_ANY fails
The tests were in to catch user errors, but they seem to get in the way of application programming :-)
The checks in *_send() remain active to catch when PCB source and destination address types do not match

Code cleanup: add some parentheses in tcp.c and tcp_out.c

tcp: Make tcp_listen_with_backlog_and_err return NULL if the address/port is already used

The caller of tcp_listen_with_backlog_and_err() usually check if the return
pcb is NULL before checking the err reason. I think the commit adding
tcp_listen_with_backlog_and_err() accidently change the behavior, Fix it.

Fixes: 98fc82fa7128 ("added function tcp_listen_with_backlog_and_err() to get the error reason when listening fails")
Signed-off-by: Axel Lin <axel.lin@ingics.com>

added function tcp_listen_with_backlog_and_err() to get the error reason when listening fails (bug #49861)

Add hook for TCP Initial Sequence Number generation

lwIP produces a TCP Initial Sequence Number (ISN) for each new TCP
connection. The current algorithm is simple and predictable however.
The result is that lwIP TCP connections may be the target of TCP
spoofing attacks. The problem of such attacks is well known, and a
recommended ISN generation algorithm is standardized in RFC 6528.
This algorithm requires a high-resolution timer and cryptographic
hashing function, though. The implementation (or best-effort
approximation) of both of these aspects is well beyond the scope of
lwIP itself.

For that reason, this patch adds LWIP_HOOK_TCP_ISN, a hook that
allows each platform to implement its own ISN generation using
locally available means. The hook provides full flexibility, in
that the hook may generate anything from a simple random number
(by being set to LWIP_RAND()) to a full RFC 6528 implementation.

Implementation note:

Users of the hook would typically declare the function prototype of
the hook function in arch/cc.h, as this is the last place where such
prototypes can be supplied. However, at that point, the ip_addr_t
type has not yet been defined. For that reason, this patch removes
the leading underscore from "struct _ip_addr", so that a prototype
of the hook function can use "struct ip_addr" instead of "ip_addr_t".

Signed-off-by: sg <goldsimon@gmx.de>

raw, udp, tcp connect() does NOT need to match exact IP type - when PCB is bound to IPADDR_ANY_TYPE, it is OK to connect to IPv4 or IPv6
This should finally implement task #14187: Dual Stack sendto with socket APIs

Dual-stack fixes in raw/udp/tcp
bind() may change IP type when previous type is IPADDR_TYPE_ANY
connect() IP type must exactly match bind IP type
Use correct IPADDRx_ANY type when calling ip_route()

Cleanup hton*/ntoh* function handling and platform abstraction
Let lwip use functions/macros prefixed by lwip_ internally to avoid naming clashes with external #includes.
Remove over-complicated #define handling in def.h
Make functions easier to override in cc.h. The following is sufficient now (no more LWIP_PLATFORM_BYTESWAP):
#define lwip_htons(x) <your_htons>
#define lwip_htonl(x) <your_htonl>

Implement consistent IPx_ADDR_ANYx macro naming between IPv4 and IPv6
- rename IP4_ADDR_ANY to IP4_ADDR_ANY4
- IP4_ADDR_ANY (= IP_ADDR_ANY) is now IPv4 any address in ip_addr_t format

Convert IP address type numbers to an enum to improve documentation

Documentation: Add one more note PCB is already freed in tcp_err callback.

Add some dual-stack notes to documentation

tcp: Make tcp_state_str/tcp_backoff/tcp_persist_backoff static

They are only referenced in tcp.c, so make them static.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: goldsimon <goldsimon@gmx.de>

update netif address change triggers to tpc & udp to work with IPv6, too

tcp: Prevents a 0 sized (invalid) backlog

commit 44e1a2d8e23f accidently includes below changes in tcp_listen_with_backlog
- tcp_backlog_set(lpcb, backlog);
+ lpcb->backlog = backlog;

Thus pass 0 to the backlog parameter of netconn_listen_with_backlog() fails.

Fixes: 44e1a2d8e23f ("define tcp_backlog_set() as dummy-define when backlog feature is disable")
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: goldsimon <goldsimon@gmx.de>

tcp.c: Partly undo Simon's changes from today (repairs doxygen docs)

Improve LWIP_EVENT_API compilation

Fix compilation for LWIP_EVENT_API

Without LWIP_CALLBACK_API, is no error callback function pointer in
the TCP PCB, nor is it needed, so do not attempt to access it.

Move rawapi.txt description to main page - this doc really should be found and read by users

Some documentation cleanups and include more comments that have been already in code into doxygen docs

Add one more documentation sentence in tcp.c

Add some more TCP RAW API functions to documentation

Document netif API in doxygen module style

Document DNS, memory pools and PBUFs as modules

Some more RAW API documentation updates
Improve structure of documentation: PPP is now a module, too

Start to document public RAW API via doxygen

Add links to new documentation pages in the relevant files

minor: fixed wrong indentation

Fixed trying to send RST for unconnected (but bound) pcb

Fix bug #48504: tcp_debug_print_pcbs reads nonexisting tcp_pcb fields

minor: coding style fixes

Fix clang warning about unreachable code

Do check with preprocessor instead

Fix several CLANG format string warnings

fixed bug #47743 (Closing listening tcp pcb is not posible without assert)

Create new IP_IS_V4 macros and use them at instead of !IP_IS_V6 - since we now have an IPADDR_ANY_TYPE, just checking for !V6 does not mean it is V4

Fixed possible problems with tcp_backlog_delayed/tcp_backlog_accepted

tcp_alloc(): Remove superfluous initialization for pcb->keep_cnt_sent

It's already done by memset(0). This was missed in commit 5794ac2340f2
"tcp_alloc(): remove explicit =0 already done by memset(0)", fix it.

Signed-off-by: Axel Lin <axel.lin@ingics.com>

tcp: changed accept handling to be done internally: the application does not have to call tcp_accepted() any more. Instead, when delaying accept (e.g. sockets do), call tcp_backlog_delayed()/tcp_backlog_accepted() (fixes bug #46696)

tcp_alloc(): remove explicit =0 already done by memset(0)

define tcp_backlog_set() as dummy-define when backlog feature is disable

Fix comment in tcp.c

TCP: Implement dual stack support using new IP_ANY_TYPE introduced at UDP

Allow backlog to be updated

This commit adds support to the sockets and netconn layer to update the
backlog by calling listen when the netconn is already in the listen state.
When backlog is not enabled, the call returns successfully

This commit also introduces a macro for setting the backlog value that
prevents a 0 sized (invalid) backlog

Implement UDP dual-stack PCB support
Create special IP address type "IPADDR_TYPE_ANY" for it.
SNMP uses new feature in non-netconn mode.

TODO: Same for TCP & RAW, adapt NETCONN to use this feature

Change signature of ip_output, ip_output_if, ip_output_if_src, ip_output_hinted, ip_route, ip_netif_get_local_ip, ip_route_get_local_ip and tcp_eff_send_mss not to take an isipv6 parameter. Use the IP version of the destination address instead.

Together with Simon: Eliminate last instances of isipv6 member in pcbs;
Don't allow NULL pointers (IPv4 ANY) in connect() and sendto() functions as destinations since this does not make sense.

Review with Simon: Init TCP/UDP/RAW PCBs with correct IP types in _new functions to make my changes work correct

Eliminate IP_PCB_IPVER_EQ macro

Reduce usage of PCB IP version flag in raw and tcp code. Maybe we can figure out a good way for dual-stack UDP when we manage to remove the flag (nearly) entirely from the code.

Fix tcp pcb access after it was freed in tcp.c - found by Coverity

tcp_bind/tcp_connect: Omit checking for the same port if no port specified

No port specified means to use a random port.
tcp_new_port() returns a new (free) local TCP port number on success.
So in this case we don't need iterating all lists to test if the port
number is used, tcp_new_port() alreay ensures the port is not used.

Signed-off-by: Axel Lin <axel.lin@ingics.com>

Drop #if TCP_DEBUG guard around tcp_debug_print_state calls

The #if TCP_DEBUG guard can be removed because tcp_debug_print_state()
print nothing if !TCP_DEBUG.

Signed-off-by: Axel Lin <axel.lin@ingics.com>

Simplify testing minimum priority in tcp_kill_prio()

Simplify the code a bit by setting mprio = LWIP_MIN(TCP_PRIO_MAX, prio)
before the for loop.

Signed-off-by: Axel Lin <axel.lin@ingics.com>

Trivial comment fix about calling tcp_slowtmr

Trivial typo fix.

Signed-off-by: Axel Lin <axel.lin@ingics.com>

Fixed compiling with LWIP_TCP==0

Fixed bug #46365: tcp_accept_null() should call tcp_abort()

Export tcp_pcb_lists from tcp.c - can be used in SNMP code to implement MIB2 tcp connection tables

Remove global variable used in macros, it can be declared locally.

started to move "private" header files containing implementation details to "lwip/priv/" include directory to seperate the API from the implementation.

minor: fixed coding style (lwip style)

minor: coding style

minor/coding style: removed spaces before line ending (from file header)

minor/coding style: removed spaces before line ending

minor: removed some trailing spaces in tcp.c

Removed ip_2_ip4/6_c const macros again now that ip_2_ip4/6 macros keep the original const'ness

eliminate temporary storage when using netif addresses for ip_addr_t* now that they have the correct type (ATTENTION: ip6_select_source_address() and ip4_netif_get_local_ip() now return ip_addr_t*!)

make netif_ip4_* get accessors return const pointers

fixed some printf formatters (mainly for window scaling code)

Compiler warning fixes (mostly constness in dual-stack configurations)

Separate mib2 counter/table callbacks from snmp agent. This both cleans up the code and should allow integration of a 3rd party agent/mib2.

support IPv4 source based routing: define LWIP_HOOK_IP4_ROUTE_SRC to point to a routing function

fixed bug #44023: TCP ssthresh value is unclear: ssthresh is set to the full send window for active open, too, and is updated once after SYN to ensure the correct send window is used

fixed bug #45818: API functions should check if type of ip_addr_t parameter matches the pcb type

fixed bug #45559: Window scaling casts u32_t to u16_t without checks

Fixed bug #45161 tcp.c / tcp_abandon / pcb->local_port set to zero but needed later for tcp_rst (introduced some months ago when fixing bug #42299)

changed IP_IS_V6_VAL() to take an instance, not a pointer (to get the _val() functions the same)

fixed missing casts found with msvc /Wall

Added some macros with extension "_val" that work on actual instances and leave away the "if != NULL" check to get rid of gcc "-Waddress" warnings in the core code at least (I might not have caught all of them, yet)

task #12722 (improve IPv4/v6 address handling): renamed ip_addr_t to ip4_addr_t, renamed ipX_addr_t to ip_addr_t and added IP version;
ip_addr_t is used for all generic IP addresses for the API, ip(4/6)_addr_t are only used internally or when initializing netifs or when calling version-related functions

fixed bug #41318 (Bad memory ref in tcp_input() after tcp_close())

tcp/udp_netif_ipv4_addr_changed(): don't change specific-address of local tcp_listen/udp_pcb to ANY on address change

fixed bug #44378 (TCP connections are not aborted on netif remove)

Fixed last commit: can only check for bound sockets, not for unbound. There's some work to do for IPv6 in TCP...

Fixed bug #41700 (Call to tcp_listen_dual() should not accept IPv4 listen PCB args)

(api break) qualify ip_addr_t as const where feasible

this changes the callback signatures of the ip_output and the
{udp,raw}_recv functions.

changes were made by going through all header files, searching for
occurrences of ip_addr_t, qualifying them as const and if required
modifying the corresponding c files, looking for other uses of ip_addr_t
that would be required.

the following header files were not treated as i'm not using them and
wouldn't see them compiled: api.h api_msg.h dhcp.h dns.h igmp.h
netifapi.h pppapi.h snmp.h snmp_msg.h snmp_structs.h ppp.h pppol2tp.h
test/*

no modifications were done on ip6_addr_t.

tcp_alloc() prefers killing CLOSING/LAST_ACK over active connections (see bug #39565) (tcp_kill_prio(): back to old implementation)

fixed bug #37614 "Errors from ipX_output are not processed". Now tcp_output(_segment) checks for the return value of ipX_output and does not try to send more on error. A netif driver can call tcp_txnow() (from tcpip_thread!) to try to send again if TX buffers are available again.

tcp_kill_prio(): prefer nearly-closed connections (waiting for the last ACK only) over established connections when out of tcp pcbs

Fixed bug #38315 tcp_eff_send_mss_impl() always subtract the difference in IPv6 header size

tcp_close_shutdown: remove invalid comment on linger: we cannot support linger for the raw API since linger implies blocking

- fixed bug #43797 set/getsockopt: SO_SNDTIMEO/SO_RCVTIMEO take int as option but should take timeval (LWIP_SO_SNDRCVTIMEO_STANDARD==0 can be used to revert to the old 'winsock' style behaviour);
- Fixed implementation of SO_ACCEPTCONN to just look at the pcb state;
- cleaned up the SO/SOF defines (only 3 left a ip_pcb level);

Parts of patch #8397 Typos corrected in comments and text outputs

fixed bug #42299 tcp_abort() leaves freed pcb on tcp_bound_pcbs list

again bug #26069: Documentation of tcp_connect() incorrectly describes handling of errors

Fixed bug #36167 tcp server crash when client closes (maximum window)

Another fix to window scaling: support queueing more than 64 KByte in ooseq data

patch #6537/#7858: TCP window scaling support (OOS queueing still needs special handling)

fixed bug #39898 tcp_fasttmr() possible lock due to infinte queue process loop

patch #8030: fixed spelling of "received"

Fix bug #36857: tcp_listen_dual_with_backlog() only works with ANY
address

Change-Id: I092a4c9978d88040214fc44a4c4b353be618d76c

tcp_abort/tcp_abandon: don't send RST if pcb->state is CLOSED

fixed bug #35435: No pcb state check before adding it to time-wait queue while closing

fixed bug #35305: pcb may be freed too early on shutdown(WR)

fixed bug #34636: FIN_WAIT_2 - Incorrect shutdown of TCP pcb: don't let PCBs time out from FIN_WAIT_2 if the RX side wasn't close (by either calling tcp_close or tcp_shutdown(RDWR))

implemented API functions to access so_options of IP pcbs (UDP, TCP, RAW) (fixes bug #35061)

fixed bug #31177: tcp timers can corrupt tcp_active_pcbs in some cases

- moved processing of refused_data to an own function (used from tcp_fasttmr and tcp_input);
- improved readability of tcp_slowtmr by using defines to access keepalive variables

Reverted invalid fix for invalid bug #34360 done yesterday...

fixed bug #33871: rejecting TCP_EVENT_RECV() for the last packet including FIN can lose data

fixed bug #34360 tcp_shutdown: RST on unacked is not send when shutting down both rx AND tx

Added a config option to randomize initial local TCP/UDP ports (so that different port ranges are used after a reboot; bug #33818; this one added tcp_init/udp_init functions again);
fixed a possible endless loop in tcp_new_port() if the number of active PCBs exceeds the number of available ports;

fixed bug #31723 (tcp_kill_prio() kills pcbs with the same prio) by updating its documentation only.

Added some more asserts to check that pcb->state != LISTEN

use PCB_IS_IPV6(pcb) instead of pcb->isipv6 everywhere

Added ipX versions for routing

Fixed pointless conversion when checking TCP port range (bug #33398)

Combined IPv4 and IPv6 code where possible, added defines to access IPv4/IPv6 in non-IP code so that the code is more readable.

... and finally, we got a first working version of a dual-stack lwIP runnin IPv4 and IPv6 in parallel - big thanks to Ivan Delamer! (this is work in progress, so please beware, test a lot and report problems!)

Fixed overflow in tcp_new_port() after changing port range to IANA "Dynamic and/or Private Ports" range

Fixed bug #33048 (Bad range for IP source port numbers) by using ports in the IANA private/dynamic range (49152 through 65535).

Fixed bug #32926 (TCP_RMV(&tcp_bound_pcbs) is called on unbound tcp pcbs) by checking if the pcb was bound (local_port != 0).

Move tcp_pcb_lists to const section.

tcp_bind: return ERR_VAL instead of ERR_ISCONN when trying to bind with state!=CLOSED; fixed a typo

tcp_slowtmr(): change the scope of 'pcb2' to reflect its block-only usage.

Fixed bug #30728: tcp_new_port() did not check listen pcbs

Fixed bug #30565 (tcp_connect() check bound list): that check did no harm but never did anything

Fixed bug #30447: tcp.c:tcp_bind() - suspicious nested #if

patch #7239: make tcp_state_str pointers constant

Fix compilation for LWIP_EVENT_API==1 (unused args)

SO_REUSE: tcp_listen/tcp_connect: make sure that the 5-tuple is unique

task #6995: Implement SO_REUSEADDR (correctly)

Minor: source code layout

Check that tcp_abort/tcp_abandon isn't called for listen-pcbs

task #10088: Fixed a bug in RST-on-close-when-not-all-data-acked implementation (plus removed some unnecessary casts)

tcp_listen() did not copy the pcb's prio

Fixed some issues in the TCP_OVERSIZE code:
- reset tcp_pcb.unsent_oversize when last_unsent is changed;
- added TCP_OVERSIZE_DBGCHECK: check tcp_pcb.unsent_oversize vs. (debug-only) tcp_seg.oversize_left to ensure the pcb counter is correct;
- fixed a memory leak in tcp_write;

task #7040 (Work on tcp_enqueue): Don't waste memory when chaining segments, added option TCP_OVERSIZE to prevent creating many small pbufs when calling tcp_write with many small blocks of data. Instead, pbufs are allocated larger than needed and the space is used for later calls to tcp_write.

tcp_connect: send timestamp-option only if (pcb->flags & TF_TIMESTAMP) != NULL (same as for passive open)

Fixed accessing invalid memory when closing a listening pcb (introduced with tcp_shutdown)

Moved stack-internal parts of tcp.h to tcp_impl.h, tcp.h now only contains the actual application programmer's API

Task #10088: Correctly implement close() vs. shutdown(). Now the application does not get any more recv callbacks after calling tcp_close(). Added tcp_shutdown().

tcp_alloc: set given prio to the new pcb, not TCP_PRIO_NORMAL; minor: changed comments and source code layout

tcp_seg(s)_free: remove return value, noone uses it

Use new macro ip_addr_copy where applicable

patch #6865: use so_options SOF_REUSEADDR instead of flags TF_REUSEADDR (which has ben removed again)

patch #6865 (SO_REUSEADDR for TCP): if tcp_pcb.flags has TF_REUSEADDR set, allow binding to endpoint in TIME_WAIT

Replaced struct ip_addr by typedef ip_addr_t to make changing the actual implementation behind the typedef easier.

Use macros defined in ip_addr.h (some of them new) to work with IP addresses (preparation for bug #27352 - Change ip_addr from struct to typedef (u32_t) - and better code).

Ensure ssthresh >= 2*MSS

Fixed bug #27871: Calling tcp_abort() in recv callback can lead to accessing unallocated memory. As a consequence, ERR_ABRT means the application has called tcp_abort()!

bug #28659: Missing casts

bug #26523: Compiler Warnings

Fixed bug #28651 (tcp_connect: no callbacks called if tcp_enqueue fails) both in raw- and netconn-API

Using typedefs for function prototypes and -pointers throughout the stack for clarity

Minor fix: bug #28555: Retransmission timer only stopped if TCP_QUEUE_OOSEQ==1

D'Oh!

bug #28127: remove call to tcp_output() from tcp_ack(_now)()

Commented 2 variables

tcp_alloc: prevent increasing stats.err for MEMP_TCP_PCB when reusing time-wait pcb as suggested by Bill 4 months ago

tcp_recv_null: call tcp_recved() if p != NULL to keep the window correct

Fixed bug #28049 (Keep Alive timeout frees pcb then uses it, sometimes causing crash error) by calling tcp_rst() instead of tcp_abort() in tcp_slowtmr() when retransmit timer expires.

Fixed comment: tcp_pcb_remove does *not* deallocate the pcb

Fixed bug #27783: Silly window avoidance for small window sizes

Make tcp_debug_state_str() always available, not only in DEBUG mode

Added function tcp_debug_state_str() to convert a tcp state to a human-readable string.

BUG27209: handle trimming of segments when out of window or out of
order properly

Added newline to TCP header flags debug print

BUG26301 and BUG26267: correct simultaneous close behaviour, and make
snd_nxt have the same meaning as in the RFCs.

BUG20515: rework way TCP window updates are calculated and sent

TASK9218: add support for TCP timestamp options

BUG25622: handle return code of tcp_enqueue in tcp_listen_input()

fixed bug #24440: TCP connection close problem on 64-bit host by moving accept callback function pointer to TCP_PCB_COMMON

fixed bug #25467: Listen backlog is not reset on timeout in SYN_RCVD: Accepts_pending is decrease on a corresponding listen pcb when a connection in state SYN_RCVD is close.

* tcp.c: Fix bug #24227, wrong error message in tcp_bind.

fixed bug #22249: division by zero could occur if a remote host sent a zero mss as TCP option.

tcp.c, tcp_in.c, tcp.h, opt.h: Rename LWIP_CALCULATE_EFF_SEND_MSS in TCP_CALCULATE_EFF_SEND_MSS to have coherent TCP options names.

rawapi.txt, api_msg.c, tcp.c, tcp_in.c, tcp.h: changes for task #7675 "Enable to refuse data on a TCP_EVENT_RECV call". Important, behavior changes for the tcp_recv callback (see rawapi.txt).

Minor change: add comment

Minor changes in lwip folder: fix some warnings, coding style, and rename "internal" netconn_alloc function.

rawapi.txt, api.h, api_lib.c, api_msg.h, api_msg.c, sockets.c, tcp.h, tcp.c, tcp_in.c, init.c, opt.h: rename backlog options with TCP_ prefix, limit the "backlog" parameter in an u8_t, 0 is interpreted as "smallest queue", add documentation in the rawapi.txt file.

Add persist timer

tcp.h, opt.h, api.h, api_msg.h, tcp.c, tcp_in.c, api_lib.c, api_msg.c, sockets.c, init.c: task #7252: Implement TCP listen backlog: Warning: raw API applications have to call 'tcp_accepted(pcb)' in their accept callback to keep accepting new connections.

Whitespace fix.

2007-12-20 Kieran Mansley (based on patch from Per-Henrik Lundbolm)
* tcp.c, tcp_in.c, tcp_out.c, tcp.h: fix bug #20199 (better handling
of silly window avoidance and prevent lwIP from shrinking the window)

fix bug #21699 (segment leak in ooseq): add assert that all segment lists are empty in tcp_pcb_remove before setting pcb to CLOSED state; don't directly set CLOSED state from LAST_ACK in tcp_process

Check state == CLOSED in tcp_bind and tcp_connect to prevent binding/connecting twice (using LWIP_ERROR: can be disabled)

Implemented calculating the effective send-mss based on the MTU of the netif used to send. Enabled by default. Disable by setting LWIP_CALCULATE_EFF_SEND_MSS to 0. This fixes bug #21535.

Fixed bug #21494: The send mss (pcb->mss) is set to 536 (or TCP_MSS if that is smaller) as long as no MSS option is received from the remote host.

Fixed bug #21491: The MSS option sent (with SYN) is now based on TCP_MSS instead of pcb->mss (on passive open now effectively sending our configured TCP_MSS instead of the one received).

Added some explaining comments.

Changed initialization: many init functions are not needed any more since we now rely on the compiler initializing global and static variables to zero!

Fixed bug #21080 (tcp_bind without check pcbs in TIME_WAIT state) by checking tcp_tw_pcbs also

Minor changes (but in lot of files): add #if/#endif for options where they could miss. #if LWIP_xxx if always put after #include "lwip/opt.h" (note this one indirectly include cc.h). Move others includes inside #if/#endif block.

Comments Fix for Doxygen documentation

Added a better comment to explain why tcp_close doesn't care for the return value of tcp_output

Another fix for bug #20021: by not returning an error if tcp_output fails in tcp_close, the code in do_close_internal gets simpler (tcp_output is called again later from tcp timers).

Fix bug #20480: Check the pcb passed to tcp_listen() for the correct state (must be CLOSED).

Added some ASSERTS and casts to prevent warnings when assigning to smaller types.

Removed warning when assigning from u32_t to u16_t by casting to u16_t.

Done some work on task #6933: converted some LWIP_ASSERTs to LWIP_ERROR to give back an error return value for LWIP_NOASSERT=1

Corrected some copy & paste errors

Done some work on task #1549 (function documentation)

Use TCP_RMV instead of tcp_pcb_remove when removing pcbs from tcp_bound_pcbs list (bug introduced while fixing bug #1895)

Fixed bug #1895 (tcp_bind not correct) by introducing a list of bound but unconnected (and non-listening) tcp_pcbs.

Included patch #5920: Create define to override C-library memcpy. 2 Defines are created: MEMCPY() for normal memcpy, SMEMCPY() for situations where some compilers might inline the copy and save a function call. Also replaced all calls to memcpy() with calls to (S)MEMCPY().

* tcp.c, tcp_in.c, tcp_out.c, tcp.h: Modify way the retransmission
timer is reset to fix bug#19434, with help from Oleg Tyshev.

Ongoing fix to patch #5822: converted more statements like (void)arg; into LWIP_UNUSED_ARG(arg);

Keepalive values can be configured at run time with LWIP_TCP_KEEPALIVE, but don't change this unless you know what you're doing (default are RFC1122 compliant). Note that TCP_KEEPIDLE and TCP_KEEPINTVL have to be set in seconds.

Old TCP_KEEPALIVE can always be used, and its only difference with TCP_KEEPIDLE is this last use seconds and not milliseconds with setsockopt.

Some documentation (not perfect, but...):

http://publib.boulder.ibm.com/infocenter/pseries/v5r3/index.jsp?topic=/com.ibm.aix.commtechref/doc/commtrf2/setsockopt.htm

Added SNMP counters.

Fix debug print, remove reference to TCP_COARSE_TIMEOUT

Remove PCBs which stay in LAST_ACK state too long.

Introduced cc.h formatters and removed SO_REUSE from transport layers.

christiaans: cosmetic change debug formatters as requested by Tom.

16th October 2004 - Kieran Mansley - kjm25@cam.ac.uk
- Add code to tcp_recved() to send an ACK (window update)
immediately, even if one is already pending, if the rcv_wnd is above a
threshold (currently TCP_WND/2)
- This avoids waiting for a timer to expire to send a delayed ACK in
order to open the window if the stack is only receiving data.

Kieran Mansley - kjm25@cam.ac.uk - 12th September 2004

Applied patch from Sam Jansen as detailed in
http://lists.gnu.org/archive/html/lwip-users/2004-07/msg00106.html
to correctly handle retransmission after a retransmission timeout

Stop compiler complaining of empty if statement when LWIP_DEBUGF() empty.

Kieran Mansley - kjm25@cam.ac.uk - 23rd July 2004

Now handle CLOSED state in tcp_close() explicitely, and free the pcb.
This is for the case that a pcb has been allocated but never used (so
is in the default "CLOSED" state) and needs to be freed.

Dependencies on C library memset() etc., so include <string.h>.

Clean-up source comment documentation for Doxygen.

Clean-up source comment documentation for Doxygen.

fix SO_REUSE ifdef fixes

Kieran Mansley - kjm25@cam.ac.uk - 23rd March 2003
- Changed all #ifdef SO_REUSE into #if SO_REUSE

Made #ifdef's into #if's for SO_REUSE.

Kieran Mansley, kjm25@cam.ac.uk, 08th Mar 2004
- added a comment to tcp_recved() to clarify reasons for call to tcp_ack()

Applied Ian Wienand's patches (4-2-2004). Was partly applied earlier.

Merged from DEVEL, except for the API change in etharp.c.

Applied alias.diff by Ian Wienand on lwip-devel on February 4th 2004.
Using union to make explicit either tcp_listen_pcb or tcp_pcb.

Merged from DEVEL to main. Two TCP fixes and two NULL reference fixes.

Merged from DEVEL into main tree.

Applied patch #1596 fixing wrongly cast LWIP_DEBUGF arguments.
(printf expects integers on the var args stack)

Changed DEBUGF to LWIP_DEBUGF

Replaced all tabs with two spaces (regardless of indentation is correct).

put LWIP_MAX and LWIP_MIN macros in def.h and use these instead of locally declaring them in .c files

patches 1492, 1493 and 1494 from Marc

Major stylo search/replace for "One space between keyword and opening bracket."

Fixed tabs into spaces. Fixed other stylos.

Prevent compiler warning on unused function arguments.

Fixed bug #3112 (faulty behaviour calling tcp_listen() when already listening)

In keeping with pbuf->ref always having the count of the number of pointers
to the particular buffer (and the last rewrite of pbuf_free), changed most
pbuf_ref_chain() calls back to pbuf_ref(). I think this was causing some pbuf
leaks.

Documentation changes. Added missing trailing newlines to debug messages.

Added documentation and comments.

if LWIP_TCP is 0 do not link in TCP code.putting ugly ifdefs in api and core :(.Also only udp_init if LWIP_UDP is on

Fixed up and made work a PBUF_REF type. Most of the code uses this now
instead of PBUF_ROM. This addition allows support of copy-on-demand where the
lower layers can call pbuf_unref() which tests for any PBUF_REF buffers and
replaces them with PBUF_POOL buffers. This is now used
everywhere. pbuf_unref() is called in ARP queueing and in the coldfire
driver, which puts frames on a DMA queue and frees them later.

Along with this change pbuf_free() now goes through the entire chain of
buffers and tests all the ref counters, not just the first one. Generally now
pbuf_ref_chain() should be called and not pbuf_ref(). This change was made
because it is possible for the head of the pbuf chain to have a different
count than the payload pbuf which might have been passed by the application.

byte-order handling functions are in inet.c now and the uperrcase counterparts are gone. opt.h has all the
configurable items debug does not need to be directly included.

do not directly include lwipopts.h but lwip/opt.h instead

Add the following features and bugfixes:

Added select() functionality to sockets library.
Support for errno in sockets library.
Byte ordering fixes.
basic lwip_ioctl(), FIONREAD, get/setsockopt() etc. support

- added additional argument to netif_add to pass state pointer so that the
if_init function has access to context information before
the interface is added, without accessing globals.

- added netif_remove()

- to conserve cpu load the tcpip_tcp_timer should only be active
when tcbs that need it exist.

- pass length of available data to callbacks for NETCONN_EVT_RCV events

- added tcpip_link_input(), a hack to allow processing of PPP
packets in tcpip_thread() context. This saves threads and context
switches.

- renamed incompatible ASSERT() macro to LWIP_ASSERT() to avoid name
collision.

- changed a bunch of %d's to %u's in format strings for unsigned values.

- added ip_frag to lwip_stats.

- changed IP_REASS_MAXAGE and IP_REASS_TMO defaults to more realistic
values.

- added sys_timeout_remove() function to cancel timeouts (needed by PPP
amongst other things).

- tolerate NULL returns from sys_arch_timeouts() since some threads might
not need to use or have timeouts.

- added sys_sem_wait_timeout()

- moved mem_malloc() function to end of mem.c to work around tasking
compiler bug.

- automatically bind to local tcp port if 0.

- allow customization of port ranges for automatic local bindings.

- corrected various typos, spelling errors, etc..

Thanks to Marc Boucher for many of these changes.

put a state field in listen PCBs to since they are often treated as normal pcbs. patch #922, bug #2114

print correct pcb->rtime value in debug statament.it does not directly depend on tcp_ticks

fix debug messages in tcp_slowtmr to reflect the correct name of this function

Merged patch #927 which fixes "needs modifiable lvalue" compile error in TCP_REG.

Updated lwIP module copyright years to include 2003. Committers must check theirs.

use memset and memcpy instead of bzero and bcopy throughout lwIP core code.Archs need to update.Bug #1899

Use C style comments.In debug stataments cast various struct pointers to void* to
avoid printf warnings.misc warnings in etharp.

Fixed argument type compiler warnings of the bcopy() call using type casting.

Added debug messages for corner cases of TCP states.

The code that increased the retransmission time was commented out for some reason. This has been fixed. Also removed some old, out-commented, code.

Fix function names in DEBUGF stataments.Remove reference to "reclaimed" field in stat.

Initialize err in tcp_slowtmr to prevent compiler warning.

Workaround for compile error on TCP_REG. This workaround is disabled by default.

Initial revision