Commit Graph

115 Commits

Author SHA1 Message Date
Kip Macy
77931dd513 Add flowtable support to IPv6
Tested by: qingli@

Reviewed by:	qingli@
MFC after:	3 days
2010-05-09 20:32:00 +00:00
Robert Watson
530c006014 Merge the remainder of kern_vimage.c and vimage.h into vnet.c and
vnet.h, we now use jails (rather than vimages) as the abstraction
for virtualization management, and what remained was specific to
virtual network stacks.  Minor cleanups are done in the process,
and comments updated to reflect these changes.

Reviewed by:	bz
Approved by:	re (vimage blanket)
2009-08-01 19:26:27 +00:00
Robert Watson
eddfbb763d Build on Jeff Roberson's linker-set based dynamic per-CPU allocator
(DPCPU), as suggested by Peter Wemm, and implement a new per-virtual
network stack memory allocator.  Modify vnet to use the allocator
instead of monolithic global container structures (vinet, ...).  This
change solves many binary compatibility problems associated with
VIMAGE, and restores ELF symbols for virtualized global variables.

Each virtualized global variable exists as a "reference copy", and also
once per virtual network stack.  Virtualized global variables are
tagged at compile-time, placing the in a special linker set, which is
loaded into a contiguous region of kernel memory.  Virtualized global
variables in the base kernel are linked as normal, but those in modules
are copied and relocated to a reserved portion of the kernel's vnet
region with the help of a the kernel linker.

Virtualized global variables exist in per-vnet memory set up when the
network stack instance is created, and are initialized statically from
the reference copy.  Run-time access occurs via an accessor macro, which
converts from the current vnet and requested symbol to a per-vnet
address.  When "options VIMAGE" is not compiled into the kernel, normal
global ELF symbols will be used instead and indirection is avoided.

This change restores static initialization for network stack global
variables, restores support for non-global symbols and types, eliminates
the need for many subsystem constructors, eliminates large per-subsystem
structures that caused many binary compatibility issues both for
monitoring applications (netstat) and kernel modules, removes the
per-function INIT_VNET_*() macros throughout the stack, eliminates the
need for vnet_symmap ksym(2) munging, and eliminates duplicate
definitions of virtualized globals under VIMAGE_GLOBALS.

Bump __FreeBSD_version and update UPDATING.

Portions submitted by:  bz
Reviewed by:            bz, zec
Discussed with:         gnn, jamie, jeff, jhb, julian, sam
Suggested by:           peter
Approved by:            re (kensmith)
2009-07-14 22:48:30 +00:00
Bjoern A. Zeeb
88d166bf19 Make callers to in6_selectsrc() and in6_pcbladdr() pass in memory
to save the selected source address rather than returning an
unreferenced copy to a pointer that might long be gone by the
time we use the pointer for anything meaningful.

Asked for by:	rwatson
Reviewed by:	rwatson
2009-06-23 22:08:55 +00:00
Robert Watson
bcf11e8d00 Move "options MAC" from opt_mac.h to opt_global.h, as it's now in GENERIC
and used in a large number of files, but also because an increasing number
of incorrect uses of MAC calls were sneaking in due to copy-and-paste of
MAC-aware code without the associated opt_mac.h include.

Discussed with:	pjd
2009-06-05 14:55:22 +00:00
Bjoern A. Zeeb
6a9148fe92 Implement UDP control block support.
So far the udp_tun_func_t had been (ab)using inp_ppcb for udp in kernel
tunneling callbacks.  Move that into the udpcb and add a field for flags
there to be used by upcoming changes instead of sticking udp only flags
into in_pcb flags2.

Bump __FreeBSD_version for ports to detect it and because of vnet* struct
size changes.

Submitted by:	jhb (7.x version)
Reviewed by:	rwatson
2009-05-23 16:51:13 +00:00
Bruce M Simpson
a3d3b633a9 Limit scope of acquisition of INP_RLOCK for multicast input filter
to the scope of its use, even though this may thrash the lock if
the INP is referenced for other purposes.

Tested by:	David Wolfskill
2009-05-01 11:05:24 +00:00
Bruce M Simpson
33cde13046 Bite the bullet, and make the IPv6 SSM and MLDv2 mega-commit:
import from p4 bms_netdev.  Summary of changes:

 * Connect netinet6/in6_mcast.c to build.
   The legacy KAME KPIs are mostly preserved.
 * Eliminate now dead code from ip6_output.c.
   Don't do mbuf bingo, we are not going to do RFC 2292 style
   CMSG tricks for multicast options as they are not required
   by any current IPv6 normative reference.
 * Refactor transports (UDP, raw_ip6) to do own mcast filtering.
   SCTP, TCP unaffected by this change.
 * Add ip6_msource, in6_msource structs to in6_var.h.
 * Hookup mld_ifinfo state to in6_ifextra, allocate from
   domifattach path.
 * Eliminate IN6_LOOKUP_MULTI(), it is no longer referenced.
   Kernel consumers which need this should use in6m_lookup().
 * Refactor IPv6 socket group memberships to use a vector (like IPv4).
 * Update ifmcstat(8) for IPv6 SSM.
 * Add witness lock order for IN6_MULTI_LOCK.
 * Move IN6_MULTI_LOCK out of lower ip6_output()/ip6_input() paths.
 * Introduce IP6STAT_ADD/SUB/INC/DEC as per rwatson's IPv4 cleanup.
 * Update carp(4) for new IPv6 SSM KPIs.
 * Virtualize ip6_mrouter socket.
   Changes mostly localized to IPv6 MROUTING.
 * Don't do a local group lookup in MROUTING.
 * Kill unused KAME prototypes in6_purgemkludge(), in6_restoremkludge().
 * Preserve KAME DAD timer jitter behaviour in MLDv1 compatibility mode.
 * Bump __FreeBSD_version to 800084.
 * Update UPDATING.

NOTE WELL:
 * This code hasn't been tested against real MLDv2 queriers
   (yet), although the on-wire protocol has been verified in Wireshark.
 * There are a few unresolved issues in the socket layer APIs to
   do with scope ID propagation.
 * There is a LOR present in ip6_output()'s use of
   in6_setscope() which needs to be resolved. See comments in mld6.c.
   This is believed to be benign and can't be avoided for the moment
   without re-introducing an indirect netisr.

This work was mostly derived from the IGMPv3 implementation, and
has been sponsored by a third party.
2009-04-29 19:19:13 +00:00
Robert Watson
f68f9f77fe Commit file omitted in r190962:
Update stats in struct udpstat using two new macros, UDPSTAT_ADD()
and UDPSTAT_INC(), rather than directly manipulating the fields
across the kernel.  This will make it easier to change the
implementation of these statistics, such as using per-CPU versions
of the data structures.

MFC after:    3 days
2009-04-12 11:53:12 +00:00
Jamie Gritton
67c19233f1 Don't bother null-checking the thread pointer before the prison checks
in udp6_connect (td is already dereferenced elsewhere without such a
check).  This makes the conversion from a sockaddr to a sockaddr_in6
always happen, so convert once at the beginning of the function rather
than twice in the middle.

Approved by:	bz (mentor)
2009-02-05 15:04:23 +00:00
Jamie Gritton
b89e82dd87 Standardize the various prison_foo_ip[46] functions and prison_if to
return zero on success and an error code otherwise.  The possible errors
are EADDRNOTAVAIL if an address being checked for doesn't match the
prison, and EAFNOSUPPORT if the prison doesn't have any addresses in
that address family.  For most callers of these functions, use the
returned error code instead of e.g. a hard-coded EADDRNOTAVAIL or
EINVAL.

Always include a jailed() check in these functions, where a non-jailed
cred always returns success (and makes no changes).  Remove the explicit
jailed() checks that preceded many of the function calls.

Approved by:	bz (mentor)
2009-02-05 14:06:09 +00:00
Randall Stewart
bbb0e3d9d5 Addresses Roberts comments on comments. Also adds
the KASSERT and checks suggested.

Reviewed by:	The udp tunneling was discussed on net@ under the
                thread entitled "Heads up -- Thinking about UDP and tunneling"
2009-01-06 13:27:56 +00:00
Randall Stewart
c7c7ea4b5a Add the ability of an alternate transport protocol
to easily tunnel over udp by providing a hook
function that will be called instead of appending
to the socket buffer.
2009-01-06 12:13:40 +00:00
Bjoern A. Zeeb
97590249ad Another step assimilating IPv[46] PCB code:
normalize IN6P_* compat flags usage to their equialent
INP_* counterpart.

Discussed with:	rwatson
Reviewed by:	rwatson
MFC after:	4 weeks
2008-12-17 13:00:18 +00:00
Bjoern A. Zeeb
fc384fa5d6 Another step assimilating IPv[46] PCB code - directly use
the inpcb names rather than the following IPv6 compat macros:
in6pcb,in6p_sp, in6p_ip6_nxt,in6p_flowinfo,in6p_vflag,
in6p_flags,in6p_socket,in6p_lport,in6p_fport,in6p_ppcb and
sotoin6pcb().

Apart from removing duplicate code in netipsec, this is a pure
whitespace, not a functional change.

Discussed with:	rwatson
Reviewed by:	rwatson (version before review requested changes)
MFC after:	4 weeks (set the timer and see then)
2008-12-15 21:50:54 +00:00
Bjoern A. Zeeb
4b79449e2f Rather than using hidden includes (with cicular dependencies),
directly include only the header files needed. This reduces the
unneeded spamming of various headers into lots of files.

For now, this leaves us with very few modules including vnet.h
and thus needing to depend on opt_route.h.

Reviewed by:	brooks, gnn, des, zec, imp
Sponsored by:	The FreeBSD Foundation
2008-12-02 21:37:28 +00:00
Bjoern A. Zeeb
413628a7e3 MFp4:
Bring in updated jail support from bz_jail branch.

This enhances the current jail implementation to permit multiple
addresses per jail. In addtion to IPv4, IPv6 is supported as well.
Due to updated checks it is even possible to have jails without
an IP address at all, which basically gives one a chroot with
restricted process view, no networking,..

SCTP support was updated and supports IPv6 in jails as well.

Cpuset support permits jails to be bound to specific processor
sets after creation.

Jails can have an unrestricted (no duplicate protection, etc.) name
in addition to the hostname. The jail name cannot be changed from
within a jail and is considered to be used for management purposes
or as audit-token in the future.

DDB 'show jails' command was added to aid debugging.

Proper compat support permits 32bit jail binaries to be used on 64bit
systems to manage jails. Also backward compatibility was preserved where
possible: for jail v1 syscalls, as well as with user space management
utilities.

Both jail as well as prison version were updated for the new features.
A gap was intentionally left as the intermediate versions had been
used by various patches floating around the last years.

Bump __FreeBSD_version for the afore mentioned and in kernel changes.

Special thanks to:
- Pawel Jakub Dawidek (pjd) for his multi-IPv4 patches
  and Olivier Houchard (cognet) for initial single-IPv6 patches.
- Jeff Roberson (jeff) and Randall Stewart (rrs) for their
  help, ideas and review on cpuset and SCTP support.
- Robert Watson (rwatson) for lots and lots of help, discussions,
  suggestions and review of most of the patch at various stages.
- John Baldwin (jhb) for his help.
- Simon L. Nielsen (simon) as early adopter testing changes
  on cluster machines as well as all the testers and people
  who provided feedback the last months on freebsd-jail and
  other channels.
- My employer, CK Software GmbH, for the support so I could work on this.

Reviewed by:	(see above)
MFC after:	3 months (this is just so that I get the mail)
X-MFC Before:   7.2-RELEASE if possible
2008-11-29 14:32:14 +00:00
Bjoern A. Zeeb
6aee2fc550 Merge in6_pcbfree() into in_pcbfree() which after the previous
IPsec change in r185366 only differed in two additonal IPv6 lines.
Rather than splattering conditional code everywhere add the v6
check centrally at this single place.

Reviewed by:	rwatson (as part of a larger changset)
MFC after:	6 weeks (*)
(*) possibly need to leave a stub wrapper in 7 to keep the symbol.
2008-11-27 12:04:35 +00:00
Bjoern A. Zeeb
0206cdb846 Remove in6_pcbdetach() as it is exactly the same function
as in_pcbdetach() and we don't need the code twice.

Reviewed by:	rwatson
MFC after:	6 weeks (*)
(*) possibly need to leave a stub wrapper in 7 to keep the symbol.
2008-11-26 20:52:26 +00:00
Robert Watson
a6a6167314 When disconnecting a UDPv6 socket, acquire the socket lock around the
changing of the so_state field, as is done in UDPv4.  Remove XXX
locking comment.

MFC after:	3 days
2008-10-12 20:01:32 +00:00
Bjoern A. Zeeb
86d02c5c63 Cache so_cred as inp_cred in the inpcb.
This means that inp_cred is always there, even after the socket
has gone away. It also means that it is constant for the lifetime
of the inp.
Both facts lead to simpler code and possibly less locking.

Suggested by:	rwatson
Reviewed by:	rwatson
MFC after:	6 weeks
X-MFC Note:	use a inp_pspare for inp_cred
2008-10-04 15:06:34 +00:00
Marko Zec
8b615593fc Step 1.5 of importing the network stack virtualization infrastructure
from the vimage project, as per plan established at devsummit 08/08:
http://wiki.freebsd.org/Image/Notes200808DevSummit

Introduce INIT_VNET_*() initializer macros, VNET_FOREACH() iterator
macros, and CURVNET_SET() context setting macros, all currently
resolving to NOPs.

Prepare for virtualization of selected SYSCTL objects by introducing a
family of SYSCTL_V_*() macros, currently resolving to their global
counterparts, i.e. SYSCTL_V_INT() == SYSCTL_INT().

Move selected #defines from sys/sys/vimage.h to newly introduced header
files specific to virtualized subsystems (sys/net/vnet.h,
sys/netinet/vinet.h etc.).

All the changes are verified to have zero functional impact at this
point in time by doing MD5 comparision between pre- and post-change
object files(*).

(*) netipsec/keysock.c did not validate depending on compile time options.

Implemented by:	julian, bz, brooks, zec
Reviewed by:	julian, bz, brooks, kris, rwatson, ...
Approved by:	julian (mentor)
Obtained from:	//depot/projects/vimage-commit2/...
X-MFC after:	never
Sponsored by:	NLnet Foundation, The FreeBSD Foundation
2008-10-02 15:37:58 +00:00
Robert Watson
4a0a13971e When invoking the udp_send() from udp6_send() due to use of a v6-mapped
IPv4 address, first drop the udbinfo and inpcb locks, which will otherwise
be recursed.  This leads to a potential minor race, but is preferable to a
deadlock when acquiring a read lock after a write lock on the inpcb.

MFC after:	3 days
Reported by:	Norbert Papke <fbsd-ml@scrapper.ca>, lioux
2008-09-22 06:44:03 +00:00
Robert Watson
7a0a0eecf0 In UDPv6, reduce scope of global udbinfo lock during append to last
matching socket by dropping it before udp6_append(), and remove
duplicate unlocks of udbinfo and inpcb in sysctl return path.

MFC after:	3 days
2008-08-31 13:16:45 +00:00
Bjoern A. Zeeb
603724d3ab Commit step 1 of the vimage project, (network stack)
virtualization work done by Marko Zec (zec@).

This is the first in a series of commits over the course
of the next few weeks.

Mark all uses of global variables to be virtualized
with a V_ prefix.
Use macros to map them back to their global names for
now, so this is a NOP change only.

We hope to have caught at least 85-90% of what is needed
so we do not invalidate a lot of outstanding patches again.

Obtained from:	//depot/projects/vimage-commit2/...
Reviewed by:	brooks, des, ed, mav, julian,
		jamie, kris, rwatson, zec, ...
		(various people I forgot, different versions)
		md5 (with a bit of help)
Sponsored by:	NLnet Foundation, The FreeBSD Foundation
X-MFC after:	never
V_Commit_Message_Reviewed_By:	more people than the patch
2008-08-17 23:27:27 +00:00
Bjoern A. Zeeb
f2f877d38c Change the parameters to in6_selectsrc():
- pass in the inp instead of both in6p_moptions and laddr.
 - pass in cred for upcoming prison checks.

Reviewed by:	rwatson
2008-07-08 18:41:36 +00:00
Robert Watson
963e491243 Use soreceive_dgram() and sosend_dgram() with UDPv6, as we do with UDPv4.
Tested by:	ps
MFC after:	3 months
2008-07-08 10:15:23 +00:00
Robert Watson
65c577c01d Drop read lock on udbinfo earlier during delivery to the last matching
UDP socket for a datagram; the inpcb read lock is sufficient to provide
inpcb stability during udp6_append().

MFC after:      1 month
2008-07-07 10:11:17 +00:00
Robert Watson
9622e84fcf Employ read locks on UDP inpcbs, rather than write locks, when
monitoring UDP connections using sysctls.  In some cases, add
previously missing locking of inpcbs, as inp_socket is followed,
which also allows us to drop global locks more quickly.

MFC after:	1 week
2008-05-29 08:27:14 +00:00
Robert Watson
c7bc5dc1f5 Acquire a read lock, rather than a write lock, on a UDPv6 inpcb when
delivering to the socket or extracting socket details for monitoring
purposes.

MFC after:	3 months
2008-04-22 12:20:33 +00:00
Robert Watson
8501a69cc9 Convert pcbinfo and inpcb mutexes to rwlocks, and modify macros to
explicitly select write locking for all use of the inpcb mutex.
Update some pcbinfo lock assertions to assert locked rather than
write-locked, although in practice almost all uses of the pcbinfo
rwlock main exclusive, and all instances of inpcb lock acquisition
are exclusive.

This change should introduce (ideally) little functional change.
However, it lays the groundwork for significantly increased
parallelism in the TCP/IP code.

MFC after:	3 months
Tested by:	kris (superset of committered patch)
2008-04-17 21:38:18 +00:00
Bjoern A. Zeeb
79ba395267 Replace the last susers calls in netinet6/ with privilege checks.
Introduce a new privilege allowing to set certain IP header options
(hop-by-hop, routing headers).

Leave a few comments to be addressed later.

Reviewed by:	rwatson (older version, before addressing his comments)
2008-01-24 08:25:59 +00:00
David E. O'Brien
9233d8f3ad un-__P() 2008-01-08 19:08:58 +00:00
David E. O'Brien
b48287a32a Clean up VCS Ids. 2007-12-10 16:03:40 +00:00
Robert Watson
30d239bc4c Merge first in a series of TrustedBSD MAC Framework KPI changes
from Mac OS X Leopard--rationalize naming for entry points to
the following general forms:

  mac_<object>_<method/action>
  mac_<object>_check_<method/action>

The previous naming scheme was inconsistent and mostly
reversed from the new scheme.  Also, make object types more
consistent and remove spaces from object types that contain
multiple parts ("posix_sem" -> "posixsem") to make mechanical
parsing easier.  Introduce a new "netinet" object type for
certain IPv4/IPv6-related methods.  Also simplify, slightly,
some entry point names.

All MAC policy modules will need to be recompiled, and modules
not updates as part of this commit will need to be modified to
conform to the new KPI.

Sponsored by:	SPARTA (original patches against Mac OS X)
Obtained from:	TrustedBSD Project, Apple Computer
2007-10-24 19:04:04 +00:00
Robert Watson
ce4d8529e3 Continue UDP/UDPv6 synchronization project:
- Fix copyrights, comments in UDPv6.
- Remove macro defines for in6pcb and udp6stat.
- Consistently refer to inpcbs as 'inp' and not also 'in6p'.

Reviewed by:	gnn, jinmei, bz
Approved by:	re (bmah)
2007-09-08 08:18:24 +00:00
Robert Watson
9e7a99e592 Continue effort to improve parity between UDPv4 and UDPv6: add a missing
scope security check for the UDPv6 socket credential lookup service,
allowing security policies to bound access to credential information.
While not an immediate issue for Jail, which doesn't allow use of UDPv6,
this may be relevant to other security policies that may wish to control
ident lookups.

While here, eliminate a very unlikely panic case, in which a socket in
the process of being freed is inspected by the sysctl.

Approved by:	re (kensmith)
Reviewed by:	bz
2007-07-27 08:25:02 +00:00
Robert Watson
8136d21ec0 Continue effort to align UDPv4 and UDPv6 implementations by merging
udp6_output() from udp6_output.c to udp6_usrreq.c, matching the UDPv4
structure, and allowing us to remove udp6_output.c.

Reviewed by:	bz, gnn
Approved by:	re (bmah)
2007-07-23 07:58:58 +00:00
Robert Watson
08af97b790 Attempt to improve feature parity between UDPv4 and UDPv6 by merging
UDPv4 features to UDPv6:

- Add MAC checks on delivery and MAC labeling on transmit.
- Check for (and reject) datagrams with destination port 0.
- For multicast delivery, check the source port only if the socket being
  considered as a destination has been connected.
- Implement UDP blackholing based on net.inet.udp.blackhole.
- Add a new ICMPv6 unreachable reply rate limiting category for failed
  delivery attempts and implement rate limiting for UDPv6 (submitted by
  bz).

Approved by:	re (kensmith)
Reviewed by:	bz
2007-07-19 22:34:25 +00:00
Robert Watson
542a638396 General style, white space, and comment cleanup; move to ANSI C
prototypes, don't use register, etc.  Synchronize structure and
layout to the IPv4 versions of these functions to a greater extent,
making visual comparison easier.

Remove now stale or incorrect comments.

Enable full lock assertions, and correct one exception handling
case where the wrong label was jumped to.

Tested by:	bz
Approved by:	re (bmah)
2007-07-09 17:47:04 +00:00
Xin LI
2a463222be Space cleanup
Approved by:	re (rwatson)
2007-07-05 16:29:40 +00:00
Xin LI
1272577e22 ANSIfy[1] plus some style cleanup nearby.
Discussed with:	gnn, rwatson
Submitted by:	Karl Sj?dahl - dunceor <dunceor gmail com> [1]
Approved by:	re (rwatson)
2007-07-05 16:23:49 +00:00
George V. Neville-Neil
b2630c2934 Commit the change from FAST_IPSEC to IPSEC. The FAST_IPSEC
option is now deprecated, as well as the KAME IPsec code.
What was FAST_IPSEC is now IPSEC.

Approved by: re
Sponsored by: Secure Computing
2007-07-03 12:13:45 +00:00
George V. Neville-Neil
2cb64cb272 Commit IPv6 support for FAST_IPSEC to the tree.
This commit includes only the kernel files, the rest of the files
will follow in a second commit.

Reviewed by:    bz
Approved by:    re
Supported by:   Secure Computing
2007-07-01 11:41:27 +00:00
Robert Watson
32f9753cfb Eliminate now-unused SUSER_ALLOWJAIL arguments to priv_check_cred(); in
some cases, move to priv_check() if it was an operation on a thread and
no other flags were present.

Eliminate caller-side jail exception checking (also now-unused); jail
privilege exception code now goes solely in kern_jail.c.

We can't yet eliminate suser() due to some cases in the KAME code where
a privilege check is performed and then used in many different deferred
paths.  Do, however, move those prototypes to priv.h.

Reviewed by:	csjp
Obtained from:	TrustedBSD Project
2007-06-12 00:12:01 +00:00
Robert Watson
afdb42748d Rename two identically named log_in_vain variables: tcp_input.c's static
log_in_vain to tcp_log_in_vain, and udp_usrreq's global log_in_vain to
udp_log_in_vain.

MFC after:	1 week
2007-02-20 10:20:03 +00:00
Bjoern A. Zeeb
1d54aa3ba9 MFp4: 92972, 98913 + one more change
In ip6_sprintf no longer use and return one of eight static buffers
for printing/logging ipv6 addresses.
The caller now has to hand in a sufficiently large buffer as first
argument.
2006-12-12 12:17:58 +00:00
Robert Watson
acd3428b7d Sweep kernel replacing suser(9) calls with priv(9) calls, assigning
specific privilege names to a broad range of privileges.  These may
require some future tweaking.

Sponsored by:           nCircle Network Security, Inc.
Obtained from:          TrustedBSD Project
Discussed on:           arch@
Reviewed (at least in part) by: mlaier, jmg, pjd, bde, ceri,
                        Alex Lyashkov <umka at sevcity dot net>,
                        Skip Ford <skip dot ford at verizon dot net>,
                        Antoine Brodin <antoine dot brodin at laposte dot net>
2006-11-06 13:42:10 +00:00
John Hay
1fcae350ae All multicast listeners on a port should get one copy of the packet. This
was broken during the locking changes.
2006-09-07 18:44:54 +00:00
Robert Watson
a152f8a361 Change semantics of socket close and detach. Add a new protocol switch
function, pru_close, to notify protocols that the file descriptor or
other consumer of a socket is closing the socket.  pru_abort is now a
notification of close also, and no longer detaches.  pru_detach is no
longer used to notify of close, and will be called during socket
tear-down by sofree() when all references to a socket evaporate after
an earlier call to abort or close the socket.  This means detach is now
an unconditional teardown of a socket, whereas previously sockets could
persist after detach of the protocol retained a reference.

This faciliates sharing mutexes between layers of the network stack as
the mutex is required during the checking and removal of references at
the head of sofree().  With this change, pru_detach can now assume that
the mutex will no longer be required by the socket layer after
completion, whereas before this was not necessarily true.

Reviewed by:	gnn
2006-07-21 17:11:15 +00:00