the fact that the loop through inpcb's in udp_input() tracks the
last inpcb while looping. We keep that name in the calling loop
but not in the delivery routine itself.
MFC after: 3 months
into in_pcbdrop(). Expand logic to detach the inpcb from its bound
address/port so that dropping a TCP connection releases the inpcb resource
reservation, which since the introduction of socket/pcb reference count
updates, has been persisting until the socket closed rather than being
released implicitly due to prior freeing of the inpcb on TCP drop.
MFC after: 3 months
common pcb tear-down logic into tcp_detach(), which is called from
either. Invoke tcp_drop() from the tcp_usr_abort() path rather than
tcp_disconnect(), as we want to drop it immediately not perform a
FIN sequence. This is one reason why some people were experiencing
panics in sodealloc(), as the netisr and aborting thread were
simultaneously trying to tear down the socket. This bug could often
be reproduced using repeated runs of the listenclose regression test.
MFC after: 3 months
PR: 96090
Reported by: Peter Kostouros <kpeter at melbpc dot org dot au>, kris
Tested by: Peter Kostouros <kpeter at melbpc dot org dot au>, kris
number state, rather than re-using pcbinfo. This introduces some
additional mutex operations during isn query, but avoids hitting the TCP
pcbinfo lock out of yet another frequently firing TCP timer.
MFC after: 3 months
holding the inpcb lock is sufficient to prevent races in reading
the address and port, as both the inpcb lock and pcbinfo lock are
required to change the address/port.
Improve consistency of spelling in assertions about inp != NULL.
MFC after: 3 months
reference. For now, we allow the possibility that the in_ppcb
pointer in the inpcb may be NULL if a timewait socket has had its
tcptw structure recycled. This allows tcp_timewait() to
consistently unlock the inpcb.
Reported by: Kazuaki Oda <kaakun at highway dot ne dot jp>
MFC after: 3 months
(tcp_sack_output_debug checks cached hints aginst computed values by walking the
scoreboard and reports discrepancies). The sack hinting code has been stable for
many months now so it is time for the debug code to go. Leaving tcp_sack_output_debug
ifdef'ed out in case we need to resurrect it at a later point.
tcp_timewait(). This corrects a bug (or lack of fixing of a bug)
in tcp_input.c:1.295.
Submitted by: Kazuaki Oda <kaakun at highway dot ne dot jp>
MFC after: 3 months
NULL. We currently do allow this to happen, but may want to remove that
possibility in the future. This case can occur when a socket is left
open after TCP wraps up, and the timewait state is recycled. This will
be cleaned up in the future.
Found by: Kazuaki Oda <kaakun at highway dot ne dot jp>
MFC after: 3 months
The INP_DROPPED check replaces the current NULL checks; the INP_TIMEWAIT
checks appear to have always been required, but not been there, which
is/was a bug. This avoids unconditionally casting of in_ppcb to a tcpcb,
when it may be a twtcb, which may have resulted in obscure ICMP-related
panics in earlier releases.
MFC after: 3 months
casts.
Consistently use intotw() to cast inp_ppcb pointers to struct tcptw *
pointers.
Consistently use intotcpcb() to cast inp_ppcb pointers to struct tcpcb *
pointers.
Don't assign tp to the results to intotcpcb() during variable declation
at the top of functions, as that is before the asserts relating to
locking have been performed. Do this later in the function after
appropriate assertions have run to allow that operation to be conisdered
safe.
MFC after: 3 months
immediately rather than jumping to the normal output handling, which
assumes we've pulled out the inpcb, which hasn't happened at this
point (and isn't necessary).
Return ECONNABORTED instead of EINVAL when the inpcb has entered
INP_TIMEWAIT or INP_DROPPED, as this is the documented error value.
This may correct the panic seen by Ganbold.
MFC after: 1 month
Reported by: Ganbold <ganbold at micom dot mng dot net>
disconnect for fully connected sockets was dropped, meaning that if
the socket was closed while the connection was alive, it would be
leaked. Structure tcp_usr_detach() so that there are two clear
parts: initiating disconnect, and reclaiming state, and reintroduce
the tcp_disconnect() call in the first part.
MFC after: 3 months
socket can have a tcp connection that has entered time wait
attached to it, in the event that shutdown() is called on the
socket and the FINs properly exchange before close(). In this
case we don't detach or free the inpcb, just leave the tcptw
detached and freed, but we must release the inpcb lock (which we
didn't previously).
MFC after: 3 months
pru_abort(), pru_detach(), and in_pcbdetach():
- Universally support and enforce the invariant that so_pcb is
never NULL, converting dozens of unnecessary NULL checks into
assertions, and eliminating dozens of unnecessary error handling
cases in protocol code.
- In some cases, eliminate unnecessary pcbinfo locking, as it is no
longer required to ensure so_pcb != NULL. For example, the receive
code no longer requires the pcbinfo lock, and the send code only
requires it if building a new connection on an otherwise unconnected
socket triggered via sendto() with an address. This should
significnatly reduce tcbinfo lock contention in the receive and send
cases.
- In order to support the invariant that so_pcb != NULL, it is now
necessary for the TCP code to not discard the tcpcb any time a
connection is dropped, but instead leave the tcpcb until the socket
is shutdown. This case is handled by setting INP_DROPPED, to
substitute for using a NULL so_pcb to indicate that the connection
has been dropped. This requires the inpcb lock, but not the pcbinfo
lock.
- Unlike all other protocols in the tree, TCP may need to retain access
to the socket after the file descriptor has been closed. Set
SS_PROTOREF in tcp_detach() in order to prevent the socket from being
freed, and add a flag, INP_SOCKREF, so that the TCP code knows whether
or not it needs to free the socket when the connection finally does
close. The typical case where this occurs is if close() is called on
a TCP socket before all sent data in the send socket buffer has been
transmitted or acknowledged. If INP_SOCKREF is found when the
connection is dropped, we release the inpcb, tcpcb, and socket instead
of flagging INP_DROPPED.
- Abort and detach protocol switch methods no longer return failures,
nor attempt to free sockets, as the socket layer does this.
- Annotate the existence of a long-standing race in the TCP timer code,
in which timers are stopped but not drained when the socket is freed,
as waiting for drain may lead to deadlocks, or have to occur in a
context where waiting is not permitted. This race has been handled
by testing to see if the tcpcb pointer in the inpcb is NULL (and vice
versa), which is not normally permitted, but may be true of a inpcb
and tcpcb have been freed. Add a counter to test how often this race
has actually occurred, and a large comment for each instance where
we compare potentially freed memory with NULL. This will have to be
fixed in the near future, but requires is to further address how to
handle the timer shutdown shutdown issue.
- Several TCP calls no longer potentially free the passed inpcb/tcpcb,
so no longer need to return a pointer to indicate whether the argument
passed in is still valid.
- Un-macroize debugging and locking setup for various protocol switch
methods for TCP, as it lead to more obscurity, and as locking becomes
more customized to the methods, offers less benefit.
- Assert copyright on tcp_usrreq.c due to significant modifications that
have been made as part of this work.
These changes significantly modify the memory management and connection
logic of our TCP implementation, and are (as such) High Risk Changes,
and likely to contain serious bugs. Please report problems to the
current@ mailing list ASAP, ideally with simple test cases, and
optionally, packet traces.
MFC after: 3 months
pru_abort(), pru_detach(), and in_pcbdetach():
- Universally support and enforce the invariant that so_pcb is
never NULL, converting dozens of unnecessary NULL checks into
assertions, and eliminating dozens of unnecessary error handling
cases in protocol code.
- In some cases, eliminate unnecessary pcbinfo locking, as it is no
longer required to ensure so_pcb != NULL. For example, in protocol
shutdown methods, and in raw IP send.
- Abort and detach protocol switch methods no longer return failures,
nor attempt to free sockets, as the socket layer does this.
- Invoke in_pcbfree() after in_pcbdetach() in order to free the
detached in_pcb structure for a socket.
MFC after: 3 months
- in_pcbdetach(), which removes the link between an inpcb and its
socket.
- in_pcbfree(), which frees a detached pcb.
Unlike the previous in_pcbdetach(), neither of these functions will
attempt to conditionally free the socket, as they are responsible only
for managing in_pcb memory. Mirror these changes into in6_pcbdetach()
by breaking it into in6_pcbdetach() and in6_pcbfree().
While here, eliminate undesired checks for NULL inpcb pointers in
sockets, as we will now have as an invariant that sockets will always
have valid so_pcb pointers.
MFC after: 3 months
rather than an error. Detaches do not "fail", they other occur or
the protocol flags SS_PROTOREF to take ownership of the socket.
soclose() no longer looks at so_pcb to see if it's NULL, relying
entirely on the protocol to decide whether it's time to free the
socket or not using SS_PROTOREF. so_pcb is now entirely owned and
managed by the protocol code. Likewise, no longer test so_pcb in
other socket functions, such as soreceive(), which have no business
digging into protocol internals.
Protocol detach routines no longer try to free the socket on detach,
this is performed in the socket code if the protocol permits it.
In rts_detach(), no longer test for rp != NULL in detach, and
likewise in other protocols that don't permit a NULL so_pcb, reduce
the incidence of testing for it during detach.
netinet and netinet6 are not fully updated to this change, which
will be in an upcoming commit. In their current state they may leak
memory or panic.
MFC after: 3 months
than an int, as an error here is not meaningful. Modify soabort() to
unconditionally free the socket on the return of pru_abort(), and
modify most protocols to no longer conditionally free the socket,
since the caller will do this.
This commit likely leaves parts of netinet and netinet6 in a situation
where they may panic or leak memory, as they have not are not fully
updated by this commit. This will be corrected shortly in followup
commits to these components.
MFC after: 3 months
reason, seems to be where new flags are getting defined:
INP_DROPPED - The protocol has terminated this connection and the socket
is not reusable: when the socket code enters the protocol,
an error is immediately returned. This will substitute for
NULLing the so_pcb socket field, helping to implement the
invariant that all valid sockets have valid pcb's in TCP.
INP_SOCKREF - The protocol has become the owner of the socket reference,
and will need to free it when freeing the pcb, which will
be used when a TCP socket is closed but still has queued
data.
MFC after: 1 month
multicast addresses from carp interface. [1]
o Rewrite carpdetach(), so that it does the following things: [1]
- Stops callouts.
- Decrements carp_suppress_preempt, if needed.
- Downs interface and sets CARP state to INIT.
- Calls carp_multicast_cleanup().
- Detaches softc from carp_if and if we are the last frees
the carp_if.
o Use new carpdetach() in carp_clone_destroy().
o In carp_ifdetach() acquire the carp_if lock and cleanup all
interfaces hanging on carp_if. [1]
o Make carp_ifdetach() static and use EVENT(9) to call it
from if_detach(). [2]
o In carp_setrun() exit if the softc doesn't have a valid pointer
to parent. [1]
Obtained from: OpenBSD [1]
Submitted by: Dan Lukes <dan obluda.cz> [2]
PR: kern/82908 [2]
net.inet.ip.portrange.reservedlow apply to IPv6 aswell as IPv4.
We could have made new sysctls for IPv6, but that potentially makes
things complicated for mapped addresses. This seems like the least
confusing option and least likely to cause obscure problems in the
future.
This change makes the mac_portacl module useful with IPv6 apps.
Reviewed by: ume
MFC after: 1 month
consumers ignore the return value, soabort() is required to succeed,
and protocols produce errors here to report multiple freeing of the
pcb, which we hope to eliminate.
right from the beginning and partly clean up the differences in handling
between SYN_SENT and SYN_RCVD (syncache).
Further changes to this code to come. This is a first incremental step
to a general overhaul and streamlining of the TCP code.
PR: kern/15095
PR: kern/92690 (partly)
Reviewed by: qingli (and tested with ANVL)
Sponsored by: TCP/IP Optimization Fundraise 2005
simultaneous open. Both the bug and the patch were verified using the
ANVL test suite.
PR: kern/74935
Submitted by: qingli (before I became committer)
Reviewed by: andre
MFC after: 5 days
threshold. Inflight doesn't make sense on a LAN as it has
trouble figuring out the maximal bandwidth because of the coarse
tick granularity.
The sysctl net.inet.tcp.inflight.rttthresh specifies the threshold
in milliseconds below which inflight will disengage. It defaults
to 10ms.
Tested by: Joao Barros <joao.barros-at-gmail.com>,
Rich Murphey <rich-at-whiteoaklabs.com>
Sponsored by: TCP/IP Optimization Fundraise 2005
it so that ip_id etc. don't get overwritten. This fixes forwarding
of fragmented IP packets through a dummynet pipe -- fragments came
out with modified and different(!) ip_id's, making it impossible to
reassemble a datagram at the receiver side.
Submitted by: Alexander Karptsov (reworked by me)
MFC after: 3 days
