tcp: Disallow re-connection of a connected socket

soconnectat() tries to ensure that one cannot connect a connected
socket. However, the check is racy and does not really prevent two
threads from a

tcp: Disallow re-connection of a connected socket

soconnectat() tries to ensure that one cannot connect a connected
socket. However, the check is racy and does not really prevent two
threads from attempting to connect the same TCP socket.

Modify tcp_connect() and tcp6_connect() to perform the check again, this
time synchronized by the inpcb lock, under which we call
soisconnecting().

Reported by: syzkaller
Reviewed by: glebius
MFC after: 2 weeks
Sponsored by: Klara, Inc.
Sponsored by: Modirum MDPay
Differential Revision: https://reviews.freebsd.org/D38507

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tcp: Remove a redundant net_epoch entry in tcp6_connect()

tcp6_connect() is always called in a net_epoch read section.

Fixes: 3d76be28ec60 ("netinet6: require network epoch for in6_pcbconnect()")

tcp: Remove a redundant net_epoch entry in tcp6_connect()

tcp6_connect() is always called in a net_epoch read section.

Fixes: 3d76be28ec60 ("netinet6: require network epoch for in6_pcbconnect()")
Reviewed by: tuexen, glebius
Sponsored by: Klara, Inc.
Differential Revision: https://reviews.freebsd.org/D38506

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tcp: use straight in_pcbconnect() in tcp_connect()

This brings tcp_connect() par with tcp6_connect(). The code removed
now is a remnant of "truncating old TIME-WAIT" removed back in 2004
in c94c54e

tcp: use straight in_pcbconnect() in tcp_connect()

This brings tcp_connect() par with tcp6_connect(). The code removed
now is a remnant of "truncating old TIME-WAIT" removed back in 2004
in c94c54e4df9a.

Reviewed by: markj, tuexen
Differential Revision: https://reviews.freebsd.org/D38405

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db_printf: fix a typo

PR: 269377

netinet: don't return conflicting inpcb in in_pcbconnect_setup()

Last time this inpcb was actually used was in tcp_connect()
before c94c54e4df9a.

tcp: bring comment for tcp_connect() up to date

We no longer use in_pcbbind() since 25102351509. The comment about
truncating old TIME-WAIT describes a code that had been removed back
in 2004 in c9

tcp: bring comment for tcp_connect() up to date

We no longer use in_pcbbind() since 25102351509. The comment about
truncating old TIME-WAIT describes a code that had been removed back
in 2004 in c94c54e4df9a.

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inpcb: use family specific sockaddr argument for connect functions

Do the cast from sockaddr to either IPv4 or IPv6 sockaddr in the
protocol's pr_connect method and from there on go down the call
st

inpcb: use family specific sockaddr argument for connect functions

Do the cast from sockaddr to either IPv4 or IPv6 sockaddr in the
protocol's pr_connect method and from there on go down the call
stack with family specific argument.

Reviewed by: markj
Differential revision: https://reviews.freebsd.org/D38356

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netinet6: require network epoch for in6_pcbconnect()

This removes recursive epoch entry in the syncache case. Fixes
unprotected access to V_in6_ifaddrhead in in6_pcbladdr(), as
well as access to pr

netinet6: require network epoch for in6_pcbconnect()

This removes recursive epoch entry in the syncache case. Fixes
unprotected access to V_in6_ifaddrhead in in6_pcbladdr(), as
well as access to prison IP address lists. It also matches what
IPv4 in_pcbconnect() does.

Reviewed by: markj
Differential revision: https://reviews.freebsd.org/D38355

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inpcb: merge two versions of in6_pcbconnect() into one

No functional change.

Reviewed by: markj
Differential revision: https://reviews.freebsd.org/D38354

tcp: retire net.inet.tcp.tcp_require_unique_port

It was a safe belt just in case if the new port allocation
behaviour introduced in 25102351509 would cause a problem.

Reviewed by: markj, rscheff,

tcp: retire net.inet.tcp.tcp_require_unique_port

It was a safe belt just in case if the new port allocation
behaviour introduced in 25102351509 would cause a problem.

Reviewed by: markj, rscheff, tuexen
Differential revision: https://reviews.freebsd.org/D38353

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tcp: reduce the size of t_rttupdated in tcpcb

During tcp session start, various mechanisms need to
track a few initial RTTs before becoming active.
Prevent overflows of the corresponding tracking co

tcp: reduce the size of t_rttupdated in tcpcb

During tcp session start, various mechanisms need to
track a few initial RTTs before becoming active.
Prevent overflows of the corresponding tracking counter
and reduce the size of tcpcb simultaneously.

Reviewed By: #transport, tuexen, guest-ccui
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D21117

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tcp: retire TCPDEBUG

This subsystem is superseded by modern debugging facilities,
e.g. DTrace probes and TCP black box logging.

We intentionally leave SO_DEBUG in place, as many utilities may
set i

tcp: retire TCPDEBUG

This subsystem is superseded by modern debugging facilities,
e.g. DTrace probes and TCP black box logging.

We intentionally leave SO_DEBUG in place, as many utilities may
set it on a socket. Also the tcp::debug DTrace probes look at
this flag on a socket.

Reviewed by: gnn, tuexen
Discussed with: rscheff, rrs, jtl
Differential revision: https://reviews.freebsd.org/D37694

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tcp: use single locked callout per tcpcb for the TCP timers

Use only one callout structure per tcpcb that is responsible for handling
all five TCP timeouts. Use locked version of callout, of course

tcp: use single locked callout per tcpcb for the TCP timers

Use only one callout structure per tcpcb that is responsible for handling
all five TCP timeouts. Use locked version of callout, of course. The
callout function tcp_timer_enter() chooses soonest timer and executes it
with lock held. Unless the timer reports that the tcpcb has been freed,
the callout is rescheduled for next soonest timer, if there is any.

With single callout per tcpcb on connection teardown we should be able
to fully stop the callout and immediately free it, avoiding use of
callout_async_drain(). There is one gotcha here: callout_stop() can
actually touch our memory when a rare race condition happens. See
comment above tcp_timer_stop(). Synchronous stop of the callout makes
tcp_discardcb() the single entry point for tcpcb destructor, merging the
tcp_freecb() to the end of the function.

While here, also remove lots of lingering checks in the beginning of
TCP timer functions. With a locked callout they are unnecessary.

While here, clean unused parts of timer KPI for the pluggable TCP stacks.

While here, remove TCPDEBUG from tcp_timer.c, as this allows for more
simplification of TCP timers. The TCPDEBUG is scheduled for removal.

Move the DTrace probes in timers to the beginning of a function, where
a tcpcb is always existing.

Discussed with: rrs, tuexen, rscheff (the TCP part of the diff)
Reviewed by: hselasky, kib, mav (the callout part)
Differential revision: https://reviews.freebsd.org/D37321

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tcp: embed inpcb into tcpcb

For the TCP protocol inpcb storage specify allocation size that would
provide space to most of the data a TCP connection needs, embedding
into struct tcpcb several struct

tcp: embed inpcb into tcpcb

For the TCP protocol inpcb storage specify allocation size that would
provide space to most of the data a TCP connection needs, embedding
into struct tcpcb several structures, that previously were allocated
separately.

The most import one is the inpcb itself. With embedding we can provide
strong guarantee that with a valid TCP inpcb the tcpcb is always valid
and vice versa. Also we reduce number of allocs/frees per connection.
The embedded inpcb is placed in the beginning of the struct tcpcb,
since in_pcballoc() requires that. However, later we may want to move
it around for cache line efficiency, and this can be done with a little
effort. The new intotcpcb() macro is ready for such move.

The congestion algorithm data, the TCP timers and osd(9) data are
also embedded into tcpcb, and temprorary struct tcpcb_mem goes away.
There was no extra allocation here, but we went through extra pointer
every time we accessed this data.

One interesting side effect is that now TCP data is allocated from
SMR-protected zone. Potentially this allows the TCP stacks or other
TCP related modules to utilize that for their own synchronization.

Large part of the change was done with sed script:

s/tp->ccv->/tp->t_ccv./g
s/tp->ccv/\&tp->t_ccv/g
s/tp->cc_algo/tp->t_cc/g
s/tp->t_timers->tt_/tp->tt_/g
s/CCV\(ccv, osd\)/\&CCV(ccv, t_osd)/g

Dependency side effect is that code that needs to know struct tcpcb
should also know struct inpcb, that added several <netinet/in_pcb.h>.

Differential revision: https://reviews.freebsd.org/D37127

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tcp: remove unused t_rttbest

No functional change intended.

Reviewed by: rscheff@
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D37401

tcp: provide macros to access inpcb and socket from a tcpcb

There should be no functional changes with this commit.

Reviewed by: rscheff
Differential revision: https://reviews.freebsd.org/D37123

tcp: add AccECN CE packet counters to tcpinfo

Provide diagnostics information around AccECN into
the tcpinfo struct.

Event: IETF 115 Hackathon
Reviewed By: tuexen, #transport
Sponsored by: NetA

tcp: add AccECN CE packet counters to tcpinfo

Provide diagnostics information around AccECN into
the tcpinfo struct.

Event: IETF 115 Hackathon
Reviewed By: tuexen, #transport
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D37280

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tcp: remove INP_TIMEWAIT flag

Mechanically cleanup INP_TIMEWAIT from the kernel sources. After
0d7445193ab, this commit shall not cause any functional changes.

Note: this flag was very often check

tcp: remove INP_TIMEWAIT flag

Mechanically cleanup INP_TIMEWAIT from the kernel sources. After
0d7445193ab, this commit shall not cause any functional changes.

Note: this flag was very often checked together with INP_DROPPED.
If we modify in_pcblookup*() not to return INP_DROPPED pcbs, we
will be able to remove most of this checks and turn them to
assertions. Some of them can be turned into assertions right now,
but that should be carefully done on a case by case basis.

Differential revision: https://reviews.freebsd.org/D36400

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tcp: in tcp_usr_detach() remove special handling of compressed time-wait

Differential revision: https://reviews.freebsd.org/D36399

Tcp progress timeout

Rack has had the ability to timeout connections that just sit idle automatically. This
feature of course is off by default and requires the user set it on (though the socket opt

Tcp progress timeout

Rack has had the ability to timeout connections that just sit idle automatically. This
feature of course is off by default and requires the user set it on (though the socket option
has been missing in tcp_usrreq.c). Lets get the progress timeout fully supported in
the base stack as well as rack.

Reviewed by: tuexen
Sponsored by: Netflix Inc
Differential Revision: https://reviews.freebsd.org/D36716

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tcp: fix simultaneous open and refine e80062a2d43

- The soisconnected() call on transition from SYN_RCVD to ESTABLISHED
is also necessary for a half-synchronized connection. Fix that
just setti

tcp: fix simultaneous open and refine e80062a2d43

- The soisconnected() call on transition from SYN_RCVD to ESTABLISHED
is also necessary for a half-synchronized connection. Fix that
just setting the flag, when we transfer SYN-SENT -> SYN-RECEIVED.
- Provide a comment that explains at what conditions the call to
soisconnected() is necessary.
- Hence mechanically rename the TF_INCQUEUE flag to TF_SONOTCONN.
- Extend the change to the BBR and RACK stacks.

Note: the interaction between the accept_filter(9) and the socket layer
is not fully consistent, yet. For most accept filters this call to
soisconnected() will not move the connection from the incomplete queue
to the complete. The move would happen only when the filter has received
the desired data, and soisconnected() would be called once again from
sorwakeup(). Ideally, we should mark socket as connected only there,
and leave the soisconnected() from SYN_RCVD->ESTABLISHED only for the
simultaneous open case. However, this doesn't yet work.

Reviewed by: rscheff, tuexen, rrs
Differential revision: https://reviews.freebsd.org/D36641

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tcp: avoid call to soisconnected() on transition to ESTABLISHED

This call existed since pre-FreeBSD times, and it is hard to understand
why it was there in the first place. After 6f3caa6d815 it def

tcp: avoid call to soisconnected() on transition to ESTABLISHED

This call existed since pre-FreeBSD times, and it is hard to understand
why it was there in the first place. After 6f3caa6d815 it definitely
became necessary always and commit message from f1ee30ccd60 confirms that.
Now that 6f3caa6d815 is effectively backed out by 07285bb4c22, the call
appears to be useful only for sockets that landed on the incomplete queue,
e.g. sockets that have accept_filter(9) enabled on them.

Provide a new TCP flag to mark connections that are known to be on the
incomplete queue, and call soisconnected() only for those connections.

Reviewed by: rrs, tuexen
Differential revision: https://reviews.freebsd.org/D36488

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tcp: tcp6_connect() requires net epoch

PR: 262663
Reported & tested by: dch
MFC after: 2 weeks

protosw: refactor protosw and domain static declaration and load

o Assert that every protosw has pr_attach. Now this structure is
only for socket protocols declarations and nothing else.
o Merge

protosw: refactor protosw and domain static declaration and load

o Assert that every protosw has pr_attach. Now this structure is
only for socket protocols declarations and nothing else.
o Merge struct pr_usrreqs into struct protosw. This was suggested
in 1996 by wollman@ (see 7b187005d18ef), and later reiterated
in 2006 by rwatson@ (see 6fbb9cf860dcd).
o Make struct domain hold a variable sized array of protosw pointers.
For most protocols these pointers are initialized statically.
Those domains that may have loadable protocols have spacers. IPv4
and IPv6 have 8 spacers each (andre@ dff3237ee54ea).
o For inetsw and inet6sw leave a comment noting that many protosw
entries very likely are dead code.
o Refactor pf_proto_[un]register() into protosw_[un]register().
o Isolate pr_*_notsupp() methods into uipc_domain.c

Reviewed by: melifaro
Differential revision: https://reviews.freebsd.org/D36232

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protosw: retire PRU_ flags and their char names

For many years only TCP debugging used them, but relatively recently
TCP DTrace probes also start to use them. Move their declarations
into tcp_debug

protosw: retire PRU_ flags and their char names

For many years only TCP debugging used them, but relatively recently
TCP DTrace probes also start to use them. Move their declarations
into tcp_debug.h, but start including tcp_debug.h unconditionally,
so that compilation with DTrace and without TCPDEBUG is possible.

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