Commit Graph

204 Commits

Author SHA1 Message Date
Mateusz Guzik
f6f6d24062 Implement lockless resource limits.
Use the same scheme implemented to manage credentials.

Code needing to look at process's credentials (as opposed to thred's) is
provided with *_proc variants of relevant functions.

Places which possibly had to take the proc lock anyway still use the proc
pointer to access limits.
2015-06-10 10:48:12 +00:00
Gleb Smirnoff
53b680caa2 In sbappend*() family of functions clear M_PROTO flags of incoming
mbufs. sbappendstream() already does this in m_demote().

PR:		196174
Sponsored by:	Nginx, Inc.
2014-12-22 15:39:24 +00:00
Gleb Smirnoff
e834a84026 Revert r274494, r274712, r275955 and provide extra comments explaining
why there could appear a zero-sized mbufs in socket buffers.

A proper fix would be to divorce record socket buffers and stream
socket buffers, and divorce pru_send that accepts normal data from
pru_send that accepts control data.
2014-12-20 22:12:04 +00:00
Gleb Smirnoff
b7413232f6 Add to sbappendstream_locked() a check against NULL mbuf, like it is done
in sbappend_locked() and sbappendrecord_locked().

This is a quick fix to the panic introduced by r274712.

A proper solution should be to make sosend_generic() avoid calling
pru_send() with NULL mbuf for the protocols that do not understand
control messages. Those protocols that understand control messages,
should be able to receive NULL mbuf, if control is non-NULL.
2014-12-20 14:19:46 +00:00
Gleb Smirnoff
651e4e6a30 Merge from projects/sendfile: extend protocols API to support
sending not ready data:
o Add new flag to pru_send() flags - PRUS_NOTREADY.
o Add new protocol method pru_ready().

Sponsored by:	Nginx, Inc.
Sponsored by:	Netflix
2014-11-30 13:24:21 +00:00
Gleb Smirnoff
0f9d0a73a4 Merge from projects/sendfile:
o Introduce a notion of "not ready" mbufs in socket buffers.  These
mbufs are now being populated by some I/O in background and are
referenced outside.  This forces following implications:
- An mbuf which is "not ready" can't be taken out of the buffer.
- An mbuf that is behind a "not ready" in the queue neither.
- If sockbet buffer is flushed, then "not ready" mbufs shouln't be
  freed.

o In struct sockbuf the sb_cc field is split into sb_ccc and sb_acc.
  The sb_ccc stands for ""claimed character count", or "committed
  character count".  And the sb_acc is "available character count".
  Consumers of socket buffer API shouldn't already access them directly,
  but use sbused() and sbavail() respectively.
o Not ready mbufs are marked with M_NOTREADY, and ready but blocked ones
  with M_BLOCKED.
o New field sb_fnrdy points to the first not ready mbuf, to avoid linear
  search.
o New function sbready() is provided to activate certain amount of mbufs
  in a socket buffer.

A special note on SCTP:
  SCTP has its own sockbufs.  Unfortunately, FreeBSD stack doesn't yet
allow protocol specific sockbufs.  Thus, SCTP does some hacks to make
itself compatible with FreeBSD: it manages sockbufs on its own, but keeps
sb_cc updated to inform the stack of amount of data in them.  The new
notion of "not ready" data isn't supported by SCTP.  Instead, only a
mechanical substitute is done: s/sb_cc/sb_ccc/.
  A proper solution would be to take away struct sockbuf from struct
socket and allow protocols to implement their own socket buffers, like
SCTP already does.  This was discussed with rrs@.

Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.
2014-11-30 12:52:33 +00:00
Gleb Smirnoff
57f43a45a3 - Move sbcheck() declaration under SOCKBUF_DEBUG.
- Improve SOCKBUF_DEBUG macros.
- Improve sbcheck().

Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.
2014-11-30 11:22:39 +00:00
Gleb Smirnoff
8967b220a3 Make sballoc() and sbfree() functions. Ideally, they could be marked
as static, but unfortunately Infiniband (ab)uses them.

Sponsored by:	Nginx, Inc.
2014-11-30 11:02:07 +00:00
Gleb Smirnoff
8146bcfea1 - Use NULL to compare a pointer.
- Use KASSERT() instead of panic.
- Remove useless 'continue', no need to restart cycle here.

Sponsored by:	Nginx, Inc.
2014-11-14 15:44:19 +00:00
Gleb Smirnoff
f274e25659 There should not be zero length mbufs in socket buffers. The code comes
from r1451, and thus can't be explained.  A patch with explicit panic()
here survived all tests.

Tested by:	pho
Sponsored by:	Nginx, Inc.
2014-11-14 06:02:29 +00:00
Hans Petter Selasky
9fd573c39d Improve transmit sending offload, TSO, algorithm in general.
The current TSO limitation feature only takes the total number of
bytes in an mbuf chain into account and does not limit by the number
of mbufs in a chain. Some kinds of hardware is limited by two
factors. One is the fragment length and the second is the fragment
count. Both of these limits need to be taken into account when doing
TSO. Else some kinds of hardware might have to drop completely valid
mbuf chains because they cannot loaded into the given hardware's DMA
engine. The new way of doing TSO limitation has been made backwards
compatible as input from other FreeBSD developers and will use
defaults for values not set.

Reviewed by:	adrian, rmacklem
Sponsored by:	Mellanox Technologies
MFC after:	1 week
2014-09-22 08:27:27 +00:00
Xin LI
2827952eb4 Don't leave the padding between the msg header and the cmsg data,
and the padding after the cmsg data un-initialized.

Submitted by:	tuexen
Security:	CVE-2014-3952
Security:	FreeBSD-SA-14:17.kmem
2014-07-08 21:54:23 +00:00
Alan Somers
8de34a88de Fix PR kern/185813 "SOCK_SEQPACKET AF_UNIX sockets with asymmetrical
buffers drop packets".  It was caused by a check for the space available
in a sockbuf, but it was checking the wrong sockbuf.

sys/sys/sockbuf.h
sys/kern/uipc_sockbuf.c
    Add sbappendaddr_nospacecheck_locked(), which is just like
    sbappendaddr_locked but doesn't validate the receiving socket's
    space.  Factor out common code into sbappendaddr_locked_internal().
    We shouldn't simply make sbappendaddr_locked check the space and
    then call sbappendaddr_nospacecheck_locked, because that would cause
    the O(n) function m_length to be called twice.

sys/kern/uipc_usrreq.c
    Use sbappendaddr_nospacecheck_locked for SOCK_SEQPACKET sockets,
    because the receiving sockbuf's size limit is irrelevant.

tests/sys/kern/unix_seqpacket_test.c
    Now that 185813 is fixed, pipe_128k_8k fails intermittently due to
    185812.  Make it fail every time by adding a usleep after starting
    the writer thread and before starting the reader thread in
    test_pipe.  That gives the writer time to fill up its send buffer.
    Also, clear the expected failure message due to 185813.  It actually
    said "185812", but that was a typo.

PR:		kern/185813
Reviewed by:	silence from freebsd-net@ and rwatson@
MFC after:	3 weeks
Sponsored by:	Spectra Logic Corporation
2014-03-06 20:24:15 +00:00
Gleb Smirnoff
761a9a1f8d Fix comment. 2014-01-17 11:09:05 +00:00
Gleb Smirnoff
1d2df300e9 - Substitute sbdrop_internal() with sbcut_internal(). The latter doesn't free
mbufs, but return chain of free mbufs to a caller. Caller can either reuse
  them or return to allocator in a batch manner.
- Implement sbdrop()/sbdrop_locked() as a wrapper around sbcut_internal().
- Expose sbcut_locked() for outside usage.

Sponsored by:	Netflix
Sponsored by:	Nginx, Inc.
Approved by:	re (marius)
2013-10-09 11:57:53 +00:00
Davide Italiano
7729cbf1a6 Fix socket buffer timeouts precision using the new sbintime_t KPI instead
of relying on the tvtohz() workaround. The latter has been introduced
lately by jhb@ (r254699) in order to have a fix that can be backported
to STABLE.

Reported by:	Vitja Makarov <vitja.makarov at gmail dot com>
Reviewed by:	jhb (earlier version)
2013-09-01 23:34:53 +00:00
Lawrence Stewart
0963c8e431 When a previous call to sbsndptr() leaves sb->sb_sndptroff at the start of an
mbuf that was fully consumed by the previous call, the mbuf ptr returned by the
current call ends up being the previous mbuf in the sb chain to the one that
contains the data we want.

This does not cause any observable issues because the mbuf copy routines happily
walk the mbuf chain to get to the data at the moff offset, which in this case
means they effectively skip over the mbuf returned by sbsndptr().

We can't adjust sb->sb_sndptr during the previous call for this case because the
next mbuf in the chain may not exist yet. We therefore need to detect the
condition and make the adjustment during the current call.

Fix by detecting the special case of moff being at the start of the next mbuf in
the chain and adjust the required accounting variables accordingly.

Reviewed by:	andre
MFC after:	2 weeks
2013-06-19 03:08:01 +00:00
Gleb Smirnoff
844cacd17c Once ng_ksocket(4) is fixed, re-apply r194662. See this revision for
longer description.

Discussed with:	andre, rwatson
Sponsored by:	Nginx, Inc.
2013-03-29 14:06:04 +00:00
Gleb Smirnoff
c8b59ea750 Use m_get() and m_getcl() instead of compat macros. 2013-03-15 10:21:18 +00:00
Gleb Smirnoff
eb1b1807af Mechanically substitute flags from historic mbuf allocator with
malloc(9) flags within sys.

Exceptions:

- sys/contrib not touched
- sys/mbuf.h edited manually
2012-12-05 08:04:20 +00:00
Eitan Adler
3eb9ab5255 Document a large number of currently undocumented sysctls. While here
fix some style(9) issues and reduce redundancy.

PR:		kern/155491
PR:		kern/155490
PR:		kern/155489
Submitted by:	Galimov Albert <wtfcrap@mail.ru>
Approved by:	bde
Reviewed by:	jhb
MFC after:	1 week
2011-12-13 00:38:50 +00:00
Bjoern A. Zeeb
b233773bb9 Increase the defaults for the maximum socket buffer limit,
and the maximum TCP send and receive buffer limits from 256kB
to 2MB.

For sb_max_adj we need to add the cast as already used in the sysctl
handler to not overflow the type doing the maths.

Note that this is just the defaults.  They will allow more memory
to be consumed per socket/connection if needed but not change the
default "idle" memory consumption.   All values are still tunable
by sysctls.

Suggested by:	gnn
Discussed on:	arch (Mar and Aug 2011)
MFC after:	3 weeks
Approved by:	re (kib)
2011-08-25 09:20:13 +00:00
Gleb Smirnoff
443301e296 Revert r194662, since it breaks ng_ksocket(4) and may break
other socket consumers with alternate sb_upcall.

PR:		kern/154676
Submitted by:	Arnaud Lacombe <lacombar gmail.com>
MFC after:	7 days
2011-04-14 14:54:22 +00:00
Andre Oppermann
4ad1c464fe In sbappendstream_locked() demote all incoming packet mbufs (and
chains) to pure data mbufs using m_demote().  This removes the
packet header and all m_tag information as they are not meaningful
anymore on a stream socket where mbufs are linked through m->m_next.
Strictly speaking a packet header can be only ever valid on the first
mbuf in an m_next chain.

sbcompress() was doing this already when the mbuf chain layout lent
itself to it (e.g. header splitting or merge-append), just not
consistently.

This frees resources at socket buffer append time instead of at
sbdrop_internal() time after data has been read from the socket.

For MAC the per packet information has done its duty and during
socket buffer appending the policy of the socket itself takes over.
With the append the packet boundaries disappear naturally and with
it any context that was based on it.  None of the residual information
from mbuf headers in the socket buffer on stream sockets was looked at.
2009-06-22 21:46:40 +00:00
John Baldwin
74fb0ba732 Rework socket upcalls to close some races with setup/teardown of upcalls.
- Each socket upcall is now invoked with the appropriate socket buffer
  locked.  It is not permissible to call soisconnected() with this lock
  held; however, so socket upcalls now return an integer value.  The two
  possible values are SU_OK and SU_ISCONNECTED.  If an upcall returns
  SU_ISCONNECTED, then the soisconnected() will be invoked on the
  socket after the socket buffer lock is dropped.
- A new API is provided for setting and clearing socket upcalls.  The
  API consists of soupcall_set() and soupcall_clear().
- To simplify locking, each socket buffer now has a separate upcall.
- When a socket upcall returns SU_ISCONNECTED, the upcall is cleared from
  the receive socket buffer automatically.  Note that a SO_SND upcall
  should never return SU_ISCONNECTED.
- All this means that accept filters should now return SU_ISCONNECTED
  instead of calling soisconnected() directly.  They also no longer need
  to explicitly clear the upcall on the new socket.
- The HTTP accept filter still uses soupcall_set() to manage its internal
  state machine, but other accept filters no longer have any explicit
  knowlege of socket upcall internals aside from their return value.
- The various RPC client upcalls currently drop the socket buffer lock
  while invoking soreceive() as a temporary band-aid.  The plan for
  the future is to add a new flag to allow soreceive() to be called with
  the socket buffer locked.
- The AIO callback for socket I/O is now also invoked with the socket
  buffer locked.  Previously sowakeup() would drop the socket buffer
  lock only to call aio_swake() which immediately re-acquired the socket
  buffer lock for the duration of the function call.

Discussed with:	rwatson, rmacklem
2009-06-01 21:17:03 +00:00
Maksim Yevmenkin
e72a94adc3 Fix sbappendrecord_locked().
The main problem is that sbappendrecord_locked() relies on sbcompress()
to set sb_mbtail. This will not happen if sbappendrecord_locked() is
called with mbuf chain made of exactly one mbuf (i.e. m0->m_next == NULL).
In this case sbcompress() will be called with m == NULL and will do
nothing. I'm not entirely sure if m == NULL is a valid argument for
sbcompress(), and, it rather pointless to call it like that, but keep
calling it so it can do SBLASTMBUFCHK().

The problem is triggered by the SOCKBUF_DEBUG kernel option that
enables SBLASTRECORDCHK() and SBLASTMBUFCHK() checks.

PR:			kern/126742
Investigated by:	pluknet < pluknet -at- gmail -dot- com >
No response from:	freebsd-current@, freebsd-bluetooth@
MFC after:		3 days
2009-04-21 19:14:13 +00:00
Robert Watson
7978014d3a Rewrite sbreserve_locked()'s comment on NULL thread pointers, eliminating
an XXXRW about the comment being stale.

MFC after:	3 days
2008-10-07 09:51:39 +00:00
Bjoern A. Zeeb
6f4745d575 Catch a possible NULL pointer deref in case the offsets got mangled
somehow.
As a consequence we may now get an unexpected result(*).
Catch that error cases with a well defined panic giving appropriate
pointers to ease debugging.

(*) While the concensus was that the case should never happen unless
    there was a bug, noone was definitively sure.

Discussed with:		kmacy (about 8 months back)
Reviewed by:		silby (as part of a larger patch in March)
MFC after:		2 months
2008-09-07 13:09:04 +00:00
George V. Neville-Neil
49f287f8c5 Update the kernel to count the number of mbufs and clusters
(all types) used per socket buffer.

Add support to netstat to print out all of the socket buffer
statistics.

Update the netstat manual page to describe the new -x flag
which gives the extended output.

Reviewed by:	rwatson, julian
2008-05-15 20:18:44 +00:00
Robert Watson
3f0bfcccfd Further clean up sorflush:
- Expose sbrelease_internal(), a variant of sbrelease() with no
  expectations about the validity of locks in the socket buffer.
- Use sbrelease_internel() in sorflush(), and as a result avoid intializing
  and destroying a socket buffer lock for the temporary stack copy of the
  actual buffer, asb.
- Add a comment indicating why we do what we do, and remove an XXX since
  things have gotten less ugly in sorflush() lately.

This makes socket close cleaner, and possibly also marginally faster.

MFC after:	3 weeks
2008-02-04 12:25:13 +00:00
Robert Watson
265de5bb62 Correct two problems relating to sorflush(), which is called to flush
read socket buffers in shutdown() and close():

- Call socantrcvmore() before sblock() to dislodge any threads that
  might be sleeping (potentially indefinitely) while holding sblock(),
  such as a thread blocked in recv().

- Flag the sblock() call as non-interruptible so that a signal
  delivered to the thread calling sorflush() doesn't cause sblock() to
  fail.  The sblock() is required to ensure that all other socket
  consumer threads have, in fact, left, and do not enter, the socket
  buffer until we're done flushin it.

To implement the latter, change the 'flags' argument to sblock() to
accept two flags, SBL_WAIT and SBL_NOINTR, rather than one M_WAITOK
flag.  When SBL_NOINTR is set, it forces a non-interruptible sx
acquisition, regardless of the setting of the disposition of SB_NOINTR
on the socket buffer; without this change it would be possible for
another thread to clear SB_NOINTR between when the socket buffer mutex
is released and sblock() is invoked.

Reviewed by:	bz, kmacy
Reported by:	Jos Backus <jos at catnook dot com>
2008-01-31 08:22:24 +00:00
Kip Macy
5e0f5cfaed Add SB_NOCOALESCE flag to disable socket buffer update in place 2007-12-17 10:02:01 +00:00
Jeff Roberson
ace8398da0 Refactor select to reduce contention and hide internal implementation
details from consumers.

 - Track individual selecters on a per-descriptor basis such that there
   are no longer collisions and after sleeping for events only those
   descriptors which triggered events must be rescaned.
 - Protect the selinfo (per descriptor) structure with a mtx pool mutex.
   mtx pool mutexes were chosen to preserve api compatibility with
   existing code which does nothing but bzero() to setup selinfo
   structures.
 - Use a per-thread wait channel rather than a global wait channel.
 - Hide select implementation details in a seltd structure which is
   opaque to the rest of the kernel.
 - Provide a 'selsocket' interface for those kernel consumers who wish to
   select on a socket when they have no fd so they no longer have to
   be aware of select implementation details.

Tested by:	kris
Reviewed on:	arch
2007-12-16 06:21:20 +00:00
Mohan Srinivasan
58d14dae6d Set the NFS server sockbuf high watermarks to the system defaults
(up form 32KB). The low highwatermark setting caused UDP fullsock
request drops, throttling thruput greatly.
Reported by: Kris Kennaway
Approved by: re@ (Ken Smith)
2007-10-12 03:56:27 +00:00
Robert Watson
049c3b6cdf Now that sx(9) locks support an interruptible lock acquire primitive,
properly observe the SB_NOINTR flag in sblock.  This restores the
required behavior that lock acquisition be interruptible on the socket
buffer I/O serialization lock to allow threads waiting for I/O to be
signaled even if they aren't the thread currently holding the I/O lock.
With this change, the sblock regression test is again passed.

Reported by:		alfred
sx(9) handiwork:	attilio
2007-05-31 11:51:22 +00:00
Robert Watson
d19e16a72c Generally migrate to ANSI function headers, and remove 'register' use. 2007-05-16 20:41:08 +00:00
Robert Watson
7abab91135 sblock() implements a sleep lock by interlocking SB_WANT and SB_LOCK flags
on each socket buffer with the socket buffer's mutex.  This sleep lock is
used to serialize I/O on sockets in order to prevent I/O interlacing.

This change replaces the custom sleep lock with an sx(9) lock, which
results in marginally better performance, better handling of contention
during simultaneous socket I/O across multiple threads, and a cleaner
separation between the different layers of locking in socket buffers.
Specifically, the socket buffer mutex is now solely responsible for
serializing simultaneous operation on the socket buffer data structure,
and not for I/O serialization.

While here, fix two historic bugs:

(1) a bug allowing I/O to be occasionally interlaced during long I/O
    operations (discovere by Isilon).

(2) a bug in which failed non-blocking acquisition of the socket buffer
    I/O serialization lock might be ignored (discovered by sam).

SCTP portion of this patch submitted by rrs.
2007-05-03 14:42:42 +00:00
Robert Watson
8c799760e1 Following movement of functions from uipc_socket2.c to uipc_socket.c and
uipc_sockbuf.c, clean up and update comments.
2007-03-26 17:05:09 +00:00
Robert Watson
20d9e5e87c Complete removal of uipc_socket2.c by moving the last few functions to
other C files:

- Move sbcreatecontrol() and sbtoxsockbuf() to uipc_sockbuf.c.  While
  sbcreatecontrol() is really an mbuf allocation routine, it does its work
  with awareness of the layout of socket buffer memory.

- Move pru_*() protocol switch stubs to uipc_socket.c where the non-stub
  versions of several of these functions live.  Likewise, move socket state
  transition calls (soisconnecting(), etc) to uipc_socket.c.  Moveo
  sodupsockaddr() and sotoxsocket().
2007-03-26 08:59:03 +00:00
Andre Oppermann
4e02375908 Maintain a pointer and offset pair into the socket buffer mbuf chain to
avoid traversal of the entire socket buffer for larger offsets on stream
sockets.

Adjust tcp_output() make use of it.

Tested by:	gallatin
2007-03-19 18:35:13 +00:00
John Baldwin
86a93d51e3 Use sysctl_handle_long() instead of duplicating it's logic for
kern.ipc.maxsockbuf so that this sysctl works for 32-bit binaries running
on amd64 via compat/freebsd32.

MFC after:	3 days
2006-09-06 21:59:36 +00:00
Robert Watson
050ac26521 Remove 'register'.
Use ANSI C prototypes/function headers.
More deterministically line wrap comments.
2006-08-02 13:01:58 +00:00
Robert Watson
eaa6dfbcc2 Reimplement socket buffer tear-down in sofree(): as the socket is no
longer referenced by other threads (hence our freeing it), we don't need
to set the can't send and can't receive flags, wake up the consumers,
perform two levels of locking, etc.  Implement a fast-path teardown,
sbdestroy(), which flushes and releases each socket buffer.  A manual
dom_dispose of the receive buffer is still required explicitly to GC
any in-flight file descriptors, etc, before flushing the buffer.

This results in a 9% UP performance improvement and 16% SMP performance
improvement on a tight loop of socket();close(); in micro-benchmarking,
but will likely also affect CPU-bound macro-benchmark performance.
2006-08-01 10:30:26 +00:00
Robert Watson
f14cce87dc Remove non-socket buffer routines from uipc_sockbuf.c, and socket buffer
specific routines from uipc_socket2.c following repo-copy.  We might
rethink the location of one or two at some point, but the division was
relatively clean.  uipc_sockbuf.c is now the home of routines that
manipulate socket buffers.
2006-07-24 16:21:31 +00:00
Robert Watson
5908c617bb Several protocol switch functions (pru_abort, pru_detach, pru_sosetlabel)
return void, so don't implement no-op versions of these functions.
Instead, consistently check if those switch pointers are NULL before
invoking them.
2006-07-11 23:18:28 +00:00
Robert Watson
6435cdafa3 Remove now unneeded opt_mac.h and mac.h includes. 2006-07-06 13:25:51 +00:00
Robert Watson
cd3a3a269f Remove sbinsertoob(), sbinsertoob_locked(). They violate (and have
basically always violated) invariannts of soreceive(), which assume
that the first mbuf pointer in a receive socket buffer can't change
while the SB_LOCK sleepable lock is held on the socket buffer,
which is precisely what these functions do.  No current protocols
invoke these functions, and removing them will help discourage them
from ever being used.  I should have removed them years ago, but
lost track of it.

MFC after:	1 week
Prodded almost by accident by:	peter
2006-06-17 22:48:34 +00:00
Robert Watson
b37ffd3189 Move some functions and definitions from uipc_socket2.c to uipc_socket.c:
- Move sonewconn(), which creates new sockets for incoming connections on
  listen sockets, so that all socket allocate code is together in
  uipc_socket.c.

- Move 'maxsockets' and associated sysctls to uipc_socket.c with the
  socket allocation code.

- Move kern.ipc sysctl node to uipc_socket.c, add a SYSCTL_DECL() for it
  to sysctl.h and remove lots of scattered implementations in various
  IPC modules.

- Sort sodealloc() after soalloc() in uipc_socket.c for dependency order
  reasons.  Statisticize soalloc() and sodealloc() as they are now
  required only in uipc_socket.c, and are internal to the socket
  implementation.

After this change, socket allocation and deallocation is entirely
centralized in one file, and uipc_socket2.c consists entirely of socket
buffer manipulation and default protocol switch functions.

MFC after:	1 month
2006-06-10 14:34:07 +00:00
Paul Saab
4f590175b7 Allow for nmbclusters and maxsockets to be increased via sysctl.
An eventhandler is used to update all the various zones that depend
on these values.
2006-04-21 09:25:40 +00:00
Robert Watson
bc725eafc7 Chance protocol switch method pru_detach() so that it returns void
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
2006-04-01 15:42:02 +00:00