tcp: utilize new solisten_clone() and solisten_enqueue()

This streamlines cloning of a socket from a listener. Now we do not
drop the inpcb lock during creation of a new socket, do not do useless
s

tcp: utilize new solisten_clone() and solisten_enqueue()

This streamlines cloning of a socket from a listener. Now we do not
drop the inpcb lock during creation of a new socket, do not do useless
state transitions, and put a fully initialized socket+inpcb+tcpcb into
the listen queue.

Before this change, first we would allocate the socket and inpcb+tcpcb via
tcp_usr_attach() as TCPS_CLOSED, link them into global list of pcbs, unlock
pcb and put this onto incomplete queue (see 6f3caa6d815). Then, after
sonewconn() we would lock it again, transition into TCPS_SYN_RECEIVED,
insert into inpcb hash, finalize initialization of tcpcb. And then, in
call into tcp_do_segment() and upon transition to TCPS_ESTABLISHED call
soisconnected(). This call would lock the listening socket once again
with a LOR protection sequence and then we would relocate the socket onto
the complete queue and only now it is ready for accept(2).

Reviewed by: rrs, tuexen
Differential revision: https://reviews.freebsd.org/D36064

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inpcb: gather v4/v6 handling code into in_pcballoc() from protocols

Reviewed by: rrs, tuexen
Differential revision: https://reviews.freebsd.org/D36062

tcp: remove a condition in tcp_usr_detach() that never happens

The comment from Robert Watson doubts that this condition ever happens.
Our analysis confirm that. Also, we found that if you manage t

tcp: remove a condition in tcp_usr_detach() that never happens

The comment from Robert Watson doubts that this condition ever happens.
Our analysis confirm that. Also, we found that if you manage to create
such a connection with help of some other bug, then after the "second
case" code is executed, the kernel will panic in other part of the stack.

Reviewed by: rrs, tuexen
Differential revision: https://reviews.freebsd.org/D35714

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sockets: use only soref()/sorele() as socket reference count

o Retire SS_FDREF as it is basically a debug flag on top of already
existing soref()/sorele().
o Convert SS_PROTOREF into soref()/sorel

sockets: use only soref()/sorele() as socket reference count

o Retire SS_FDREF as it is basically a debug flag on top of already
existing soref()/sorele().
o Convert SS_PROTOREF into soref()/sorele().
o Change reference model for the listen queues, see below.
o Make sofree() private. The correct KPI to use is only sorele().
o Make soabort() respect the model and sorele() instead of sofree().

Note on listening queues. Until now the sockets on a queue had zero
reference count. And the reference were given only upon accept(2). The
assumption was that there is no way to see the queued socket from anywhere
except its head. This is not true, since queued sockets already have pcbs,
which are linked at least into the global pcb lists. With this change we
put the reference right in the sonewconn() and on accept(2) path we just
hand the existing reference to the file descriptor.

Differential revision: https://reviews.freebsd.org/D35679

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tcp: use a TCP flag to check if connection has been close(2)d

The flag SS_NOFDREF is a private flag of the socket layer. It also
is supposed to be read with SOCK_LOCK(), which we don't own here.

R

tcp: use a TCP flag to check if connection has been close(2)d

The flag SS_NOFDREF is a private flag of the socket layer. It also
is supposed to be read with SOCK_LOCK(), which we don't own here.

Reviewed by: rrs, tuexen
Differential revision: https://reviews.freebsd.org/D35663

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Unlock inp when handling TCP_MD5SIG socket options

Unlock the inp when hanlding TCP_MD5SIG socket options. tcp_ipsec_pcbctl
handles locking the inp when the option is being modified.

This was found

Unlock inp when handling TCP_MD5SIG socket options

Unlock the inp when hanlding TCP_MD5SIG socket options. tcp_ipsec_pcbctl
handles locking the inp when the option is being modified.

This was found by Claudio Jeker while working on the OpenBGPd port.

On 14 we get a panic when trying to call getsockopt, on 13.1 the process
locks up using 100% CPU.

Reviewed by: rscheff (transport), tuexen
MFC after: 3 days
Sponsored by: Klara Inc.
Differential Revision: https://reviews.freebsd.org/D35532

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tcp: plug set-but-not-used vars

Sponsored by: Rubicon Communications, LLC ("Netgate")

tcp: Congestion control move to using reference counting.

In the transport call on 12/3 Gleb asked to move the CC modules towards
using reference counting to prevent folks from unloading a module in

tcp: Congestion control move to using reference counting.

In the transport call on 12/3 Gleb asked to move the CC modules towards
using reference counting to prevent folks from unloading a module in use.
It was also agreed that Michael would do a user space utility like tcp_drop
that could be used to move all connections that are using a specific CC
to some other CC.

This is the half I committed to doing, making it so that we maintain a refcount
on a cc module every time a pcb refers to it and decrementing that every
time a pcb no longer uses a cc module. This also helps us simplify the
whole unloading process by getting rid of tcp_ccunload() which munged
through all the tcb's. Instead we mark a module as being removed and
prevent further references to it. We also make sure that if a module is
marked as being removed it cannot be made as the default and also
the opposite of that, if its a default it fails and does not mark it as being
removed.

Reviewed by: Michael Tuexen, Gleb Smirnoff
Sponsored by: Netflix Inc.
Differential Revision: https://reviews.freebsd.org/D33249

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tcp: Add/update AccECN related statistics and numbers

Reserve couters in the tcps struct in preparation
for AccECN, extend the debugging output for TF2
flags, optimize the syncache flags from indivi

tcp: Add/update AccECN related statistics and numbers

Reserve couters in the tcps struct in preparation
for AccECN, extend the debugging output for TF2
flags, optimize the syncache flags from individual
bits to a codepoint for the specifc ECN handshake.

This is in preparation of AccECN.

No functional chance except for extended debug
output capabilities.

Reviewed By: #transport, rrs
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D34161

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tcp: fix compliation when KERN_TLS is not defined

Reported by: Gary Jennejohn
Fixes: fd7daa727126 - main - tcp: make tcp_ctloutput_set() non-static
Sponsored by: Netflix, Inc.

tcp: make tcp_ctloutput_set() non-static

tcp_ctloutput_set() will be used via the sysctl interface in a
upcoming command line tool tcpsso.

Reviewed by: glebius, rscheff
Sponsored by: Netflix, Inc

tcp: make tcp_ctloutput_set() non-static

tcp_ctloutput_set() will be used via the sysctl interface in a
upcoming command line tool tcpsso.

Reviewed by: glebius, rscheff
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D34164

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tcp: Prevent setting of ECN bits with setsockopt()

setsockopt() grants full access to the deprecated
TOS byte. For TCP, mask out the ECN codepoint, so that
only the DSCP portion can be adjusted.

Re

tcp: Prevent setting of ECN bits with setsockopt()

setsockopt() grants full access to the deprecated
TOS byte. For TCP, mask out the ECN codepoint, so that
only the DSCP portion can be adjusted.

Reviewed By: tuexen, hselasky, #manpages, #transport, debdrup
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D34154

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tcp: cleanup functions related to socket option handling

Consistently only pass the inp and the sopt around. Don't pass the
so around, since in a upcoming commit tcp_ctloutput_set() will be
called f

tcp: cleanup functions related to socket option handling

Consistently only pass the inp and the sopt around. Don't pass the
so around, since in a upcoming commit tcp_ctloutput_set() will be
called from a context different from setsockopt(). Also expect
the inp to be locked when calling tcp_ctloutput_[gs]et(), this is
also required for the upcoming use by tcpsso, a command line tool
to set socket options.
Reviewed by: glebius, rscheff
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D34151

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tcp: Warning cleanup from new compiler.

The clang compiler recently got an update that generates warnings of unused
variables where they were set, and then never used. This revision goes through
the

tcp: Warning cleanup from new compiler.

The clang compiler recently got an update that generates warnings of unused
variables where they were set, and then never used. This revision goes through
the tcp stack and cleans all of those up.

Reviewed by: Michael Tuexen, Gleb Smirnoff
Sponsored by: Netflix Inc.
Differential Revision:

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tcp_usr_connect: report actual error code when stack requests drop

tcp_usr_shutdown: don't cast inp_ppcb to tcpcb before checking inp_flags

While here move out one more erroneous condition out of the epoch and
common return. The only functional change is that if w

tcp_usr_shutdown: don't cast inp_ppcb to tcpcb before checking inp_flags

While here move out one more erroneous condition out of the epoch and
common return. The only functional change is that if we send control
on a shut down socket we would get EINVAL instead of ECONNRESET.

Reviewed by: tuexen
Reported by: syzbot+8388cf7f401a7b6bece6@syzkaller.appspotmail.com
Fixes: f64dc2ab5be38e5366271ef85ea90d8cb1c7841a

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tcp_usr_shutdown: don't cast inp_ppcb to tcpcb before checking inp_flags

Fixes: f64dc2ab5be38e5366271ef85ea90d8cb1c7841a

tcp_usr_rcvd: don't cast inp_ppcb to tcpcb before checking inp_flags

Fixes: f64dc2ab5be38e5366271ef85ea90d8cb1c7841a

tcp: remove delayed drop KPI

No longer needed after tcp_output() can ask caller to drop.

Reviewed by: rrs, tuexen
Differential revision: https://reviews.freebsd.org/D33371

tcp: TCP output method can request tcp_drop

The advanced TCP stacks (bbr, rack) may decide to drop a TCP connection
when they do output on it. The default stack never does this, thus
existing frame

tcp: TCP output method can request tcp_drop

The advanced TCP stacks (bbr, rack) may decide to drop a TCP connection
when they do output on it. The default stack never does this, thus
existing framework expects tcp_output() always to return locked and
valid tcpcb.

Provide KPI extension to satisfy demands of advanced stacks. If the
output method returns negative error code, it means that caller must
call tcp_drop().

In tcp_var() provide three inline methods to call tcp_output():
- tcp_output() is a drop-in replacement for the default stack, so that
default stack can continue using it internally without modifications.
For advanced stacks it would perform tcp_drop() and unlock and report
that with negative error code.
- tcp_output_unlock() handles the negative code and always converts
it to positive and always unlocks.
- tcp_output_nodrop() just calls the method and leaves the responsibility
to drop on the caller.

Sweep over the advanced stacks and use new KPI instead of using HPTS
delayed drop queue for that.

Reviewed by: rrs, tuexen
Differential revision: https://reviews.freebsd.org/D33370

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tcp: mechanically substitute call to tfb_tcp_output to new method.

Made with sed(1) execution:

sed -Ef sed -i "" $(grep --exclude tcp_var.h -lr tcp_output sys/)

sed:
s/tp->t_fb->tfb_tcp_output\(tp

tcp: mechanically substitute call to tfb_tcp_output to new method.

Made with sed(1) execution:

sed -Ef sed -i "" $(grep --exclude tcp_var.h -lr tcp_output sys/)

sed:
s/tp->t_fb->tfb_tcp_output\(tp\)/tcp_output(tp)/
s/to tfb_tcp_output\(\)/to tcp_output()/

Reviewed by: rrs, tuexen
Differential revision: https://reviews.freebsd.org/D33366

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tcp_usr_detach: revert debugging piece from f5cf1e5f5a500.

The code was probably useful during the problem being chased down,
but for brevity makes sense just to return to the original KASSERT.

Rev

tcp_usr_detach: revert debugging piece from f5cf1e5f5a500.

The code was probably useful during the problem being chased down,
but for brevity makes sense just to return to the original KASSERT.

Reviewed by: rrs
Differential revision: https://reviews.freebsd.org/D32968

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tcp: Fix a locking issue

INP_WLOCK_RECHECK_CLEANUP() and INP_WLOCK_RECHECK() might return
from the function, so any locks held must be released.

Reported by: syzbot+b1a888df08efaa7b4bf1@syzkaller.

tcp: Fix a locking issue

INP_WLOCK_RECHECK_CLEANUP() and INP_WLOCK_RECHECK() might return
from the function, so any locks held must be released.

Reported by: syzbot+b1a888df08efaa7b4bf1@syzkaller.appspotmail.com
Reviewed by: markj
Sponsored by: Netflix, Inc.
Differential Revision: https://reviews.freebsd.org/D32975

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tcp: Congestion control cleanup.

NOTE: HEADS UP read the note below if your kernel config is not including GENERIC!!

This patch does a bit of cleanup on TCP congestion control modules. There were s

tcp: Congestion control cleanup.

NOTE: HEADS UP read the note below if your kernel config is not including GENERIC!!

This patch does a bit of cleanup on TCP congestion control modules. There were some rather
interesting surprises that one could get i.e. where you use a socket option to change
from one CC (say cc_cubic) to another CC (say cc_vegas) and you could in theory get
a memory failure and end up on cc_newreno. This is not what one would expect. The
new code fixes this by requiring a cc_data_sz() function so we can malloc with M_WAITOK
and pass in to the init function preallocated memory. The CC init is expected in this
case *not* to fail but if it does and a module does break the
"no fail with memory given" contract we do fall back to the CC that was in place at the time.

This also fixes up a set of common newreno utilities that can be shared amongst other
CC modules instead of the other CC modules reaching into newreno and executing
what they think is a "common and understood" function. Lets put these functions in
cc.c and that way we have a common place that is easily findable by future developers or
bug fixers. This also allows newreno to evolve and grow support for its features i.e. ABE
and HYSTART++ without having to dance through hoops for other CC modules, instead
both newreno and the other modules just call into the common functions if they desire
that behavior or roll there own if that makes more sense.

Note: This commit changes the kernel configuration!! If you are not using GENERIC in
some form you must add a CC module option (one of CC_NEWRENO, CC_VEGAS, CC_CUBIC,
CC_CDG, CC_CHD, CC_DCTCP, CC_HTCP, CC_HD). You can have more than one defined
as well if you desire. Note that if you create a kernel configuration that does not
define a congestion control module and includes INET or INET6 the kernel compile will
break. Also you need to define a default, generic adds 'options CC_DEFAULT=\"newreno\"
but you can specify any string that represents the name of the CC module (same names
that show up in the CC module list under net.inet.tcp.cc). If you fail to add the
options CC_DEFAULT in your kernel configuration the kernel build will also break.

Reviewed by: Michael Tuexen
Sponsored by: Netflix Inc.
RELNOTES:YES
Differential Revision: https://reviews.freebsd.org/D32693

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Factor out tcp6_use_min_mtu() to handle IPV6_USE_MIN_MTU by TCP.

Pass control for IP/IP6 level options from generic tcp_ctloutput_set()
down to per-stack ctloutput.

Call tcp6_use_min_mtu() from tcp

Factor out tcp6_use_min_mtu() to handle IPV6_USE_MIN_MTU by TCP.

Pass control for IP/IP6 level options from generic tcp_ctloutput_set()
down to per-stack ctloutput.

Call tcp6_use_min_mtu() from tcp stack tcp_default_ctloutput().

Reviewed by: rrs
Differential Revision: https://reviews.freebsd.org/D32655

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