Commit Graph

270 Commits

Author SHA1 Message Date
Gleb Smirnoff
e06432800f Provide pr_ctloutput method for AF_LOCAL/SOCK_SEQPACKET sockets.
This makes setsockopt() on them working.

Reported by:	Yuri <yuri rawbw.com>
Approved by:	re (kib)
2013-09-11 18:22:30 +00:00
Pawel Jakub Dawidek
7008be5bd7 Change the cap_rights_t type from uint64_t to a structure that we can extend
in the future in a backward compatible (API and ABI) way.

The cap_rights_t represents capability rights. We used to use one bit to
represent one right, but we are running out of spare bits. Currently the new
structure provides place for 114 rights (so 50 more than the previous
cap_rights_t), but it is possible to grow the structure to hold at least 285
rights, although we can make it even larger if 285 rights won't be enough.

The structure definition looks like this:

	struct cap_rights {
		uint64_t	cr_rights[CAP_RIGHTS_VERSION + 2];
	};

The initial CAP_RIGHTS_VERSION is 0.

The top two bits in the first element of the cr_rights[] array contain total
number of elements in the array - 2. This means if those two bits are equal to
0, we have 2 array elements.

The top two bits in all remaining array elements should be 0.
The next five bits in all array elements contain array index. Only one bit is
used and bit position in this five-bits range defines array index. This means
there can be at most five array elements in the future.

To define new right the CAPRIGHT() macro must be used. The macro takes two
arguments - an array index and a bit to set, eg.

	#define	CAP_PDKILL	CAPRIGHT(1, 0x0000000000000800ULL)

We still support aliases that combine few rights, but the rights have to belong
to the same array element, eg:

	#define	CAP_LOOKUP	CAPRIGHT(0, 0x0000000000000400ULL)
	#define	CAP_FCHMOD	CAPRIGHT(0, 0x0000000000002000ULL)

	#define	CAP_FCHMODAT	(CAP_FCHMOD | CAP_LOOKUP)

There is new API to manage the new cap_rights_t structure:

	cap_rights_t *cap_rights_init(cap_rights_t *rights, ...);
	void cap_rights_set(cap_rights_t *rights, ...);
	void cap_rights_clear(cap_rights_t *rights, ...);
	bool cap_rights_is_set(const cap_rights_t *rights, ...);

	bool cap_rights_is_valid(const cap_rights_t *rights);
	void cap_rights_merge(cap_rights_t *dst, const cap_rights_t *src);
	void cap_rights_remove(cap_rights_t *dst, const cap_rights_t *src);
	bool cap_rights_contains(const cap_rights_t *big, const cap_rights_t *little);

Capability rights to the cap_rights_init(), cap_rights_set(),
cap_rights_clear() and cap_rights_is_set() functions are provided by
separating them with commas, eg:

	cap_rights_t rights;

	cap_rights_init(&rights, CAP_READ, CAP_WRITE, CAP_FSTAT);

There is no need to terminate the list of rights, as those functions are
actually macros that take care of the termination, eg:

	#define	cap_rights_set(rights, ...)				\
		__cap_rights_set((rights), __VA_ARGS__, 0ULL)
	void __cap_rights_set(cap_rights_t *rights, ...);

Thanks to using one bit as an array index we can assert in those functions that
there are no two rights belonging to different array elements provided
together. For example this is illegal and will be detected, because CAP_LOOKUP
belongs to element 0 and CAP_PDKILL to element 1:

	cap_rights_init(&rights, CAP_LOOKUP | CAP_PDKILL);

Providing several rights that belongs to the same array's element this way is
correct, but is not advised. It should only be used for aliases definition.

This commit also breaks compatibility with some existing Capsicum system calls,
but I see no other way to do that. This should be fine as Capsicum is still
experimental and this change is not going to 9.x.

Sponsored by:	The FreeBSD Foundation
2013-09-05 00:09:56 +00:00
Mateusz Guzik
a82a370603 Fix receiving fd over unix socket broken in r247740.
If n fds were passed, it would receive the first one n times.

Reported by:	Shawn Webb <lattera@gmail.com>, koobs, gleb
Tested by:	koobs, gleb
Reviewed by:	pjd
2013-07-02 07:36:04 +00:00
Gleb Smirnoff
82e825c4c9 Improve r250890, so that we stop processing of a message with zero
descriptors as early as possible, and assert that number of descriptors
is positive in unp_freerights().

Reviewed by:	mjg, pjd, jilles
2013-06-04 11:19:08 +00:00
Mateusz Guzik
ecbb2a1819 passing fd over unix socket: fix a corner case where caller
wants to pass no descriptors.

Previously the kernel would leak memory and try to free a potentially
arbitrary pointer.

Reviewed by:	pjd
2013-05-21 21:58:00 +00:00
Eitan Adler
7a2b450ff8 Fxi a bunch of typos.
PR:	misc/174625
Submitted by:	Jeremy Chadwick <jdc@koitsu.org>
2013-05-10 16:41:26 +00:00
Mateusz Guzik
db8f33fd32 Add fdallocn function and use it when passing fds over unix socket.
This gets rid of "unp_externalize fdalloc failed" panic.

Reviewed by:	pjd
MFC after:	1 week
2013-04-14 17:08:34 +00:00
Jilles Tjoelker
c2e3c52e0d Implement SOCK_CLOEXEC, SOCK_NONBLOCK and MSG_CMSG_CLOEXEC.
This change allows creating file descriptors with close-on-exec set in some
situations. SOCK_CLOEXEC and SOCK_NONBLOCK can be OR'ed in socket() and
socketpair()'s type parameter, and MSG_CMSG_CLOEXEC to recvmsg() makes file
descriptors (SCM_RIGHTS) atomically close-on-exec.

The numerical values for SOCK_CLOEXEC and SOCK_NONBLOCK are as in NetBSD.
MSG_CMSG_CLOEXEC is the first free bit for MSG_*.

The SOCK_* flags are not passed to MAC because this may cause incorrect
failures and can be done later via fcntl() anyway. On the other hand, audit
is expected to cope with the new flags.

For MSG_CMSG_CLOEXEC, unp_externalize() is extended to take a flags
argument.

Reviewed by:	kib
2013-03-19 20:58:17 +00:00
Pawel Jakub Dawidek
be26ba7cd3 Fix memory leak when one process send descriptor over UNIX domain socket,
but the other process exited before receiving it.
2013-03-11 22:59:07 +00:00
Pawel Jakub Dawidek
8cb539f18f For some reason when I started to pass filedescent structures instead of
pointers to the file structure receiving descriptors stopped to work when also
at least few kilobytes of data is being send. In the kernel the
soreceive_generic() function doesn't see control mbuf as the first mbuf and
unp_externalize() is never called, first 6(?) kilobytes of data is missing as
well on receiving end.

This breaks for example tmux.

I don't know yet why going from 8 bytes to sizeof(struct filedescent) per
descriptor (or even to 16 bytes per descriptor) breaks things, but to
work-around it for now use 8 bytes per file descriptor at the cost of memory
allocation.

Reported by:	flo, Diane Bruce, Jan Beich <jbeich@tormail.org>
Simple testcase provided by:	mjg
2013-03-03 23:39:30 +00:00
Pawel Jakub Dawidek
a6157c3d61 Plug memory leaks in file descriptors passing. 2013-03-03 23:23:35 +00:00
Pawel Jakub Dawidek
7493f24ee6 - Implement two new system calls:
int bindat(int fd, int s, const struct sockaddr *addr, socklen_t addrlen);
	int connectat(int fd, int s, const struct sockaddr *name, socklen_t namelen);

  which allow to bind and connect respectively to a UNIX domain socket with a
  path relative to the directory associated with the given file descriptor 'fd'.

- Add manual pages for the new syscalls.

- Make the new syscalls available for processes in capability mode sandbox.

- Add capability rights CAP_BINDAT and CAP_CONNECTAT that has to be present on
  the directory descriptor for the syscalls to work.

- Update audit(4) to support those two new syscalls and to handle path
  in sockaddr_un structure relative to the given directory descriptor.

- Update procstat(1) to recognize the new capability rights.

- Document the new capability rights in cap_rights_limit(2).

Sponsored by:	The FreeBSD Foundation
Discussed with:	rwatson, jilles, kib, des
2013-03-02 21:11:30 +00:00
Pawel Jakub Dawidek
2609222ab4 Merge Capsicum overhaul:
- Capability is no longer separate descriptor type. Now every descriptor
  has set of its own capability rights.

- The cap_new(2) system call is left, but it is no longer documented and
  should not be used in new code.

- The new syscall cap_rights_limit(2) should be used instead of
  cap_new(2), which limits capability rights of the given descriptor
  without creating a new one.

- The cap_getrights(2) syscall is renamed to cap_rights_get(2).

- If CAP_IOCTL capability right is present we can further reduce allowed
  ioctls list with the new cap_ioctls_limit(2) syscall. List of allowed
  ioctls can be retrived with cap_ioctls_get(2) syscall.

- If CAP_FCNTL capability right is present we can further reduce fcntls
  that can be used with the new cap_fcntls_limit(2) syscall and retrive
  them with cap_fcntls_get(2).

- To support ioctl and fcntl white-listing the filedesc structure was
  heavly modified.

- The audit subsystem, kdump and procstat tools were updated to
  recognize new syscalls.

- Capability rights were revised and eventhough I tried hard to provide
  backward API and ABI compatibility there are some incompatible changes
  that are described in detail below:

	CAP_CREATE old behaviour:
	- Allow for openat(2)+O_CREAT.
	- Allow for linkat(2).
	- Allow for symlinkat(2).
	CAP_CREATE new behaviour:
	- Allow for openat(2)+O_CREAT.

	Added CAP_LINKAT:
	- Allow for linkat(2). ABI: Reuses CAP_RMDIR bit.
	- Allow to be target for renameat(2).

	Added CAP_SYMLINKAT:
	- Allow for symlinkat(2).

	Removed CAP_DELETE. Old behaviour:
	- Allow for unlinkat(2) when removing non-directory object.
	- Allow to be source for renameat(2).

	Removed CAP_RMDIR. Old behaviour:
	- Allow for unlinkat(2) when removing directory.

	Added CAP_RENAMEAT:
	- Required for source directory for the renameat(2) syscall.

	Added CAP_UNLINKAT (effectively it replaces CAP_DELETE and CAP_RMDIR):
	- Allow for unlinkat(2) on any object.
	- Required if target of renameat(2) exists and will be removed by this
	  call.

	Removed CAP_MAPEXEC.

	CAP_MMAP old behaviour:
	- Allow for mmap(2) with any combination of PROT_NONE, PROT_READ and
	  PROT_WRITE.
	CAP_MMAP new behaviour:
	- Allow for mmap(2)+PROT_NONE.

	Added CAP_MMAP_R:
	- Allow for mmap(PROT_READ).
	Added CAP_MMAP_W:
	- Allow for mmap(PROT_WRITE).
	Added CAP_MMAP_X:
	- Allow for mmap(PROT_EXEC).
	Added CAP_MMAP_RW:
	- Allow for mmap(PROT_READ | PROT_WRITE).
	Added CAP_MMAP_RX:
	- Allow for mmap(PROT_READ | PROT_EXEC).
	Added CAP_MMAP_WX:
	- Allow for mmap(PROT_WRITE | PROT_EXEC).
	Added CAP_MMAP_RWX:
	- Allow for mmap(PROT_READ | PROT_WRITE | PROT_EXEC).

	Renamed CAP_MKDIR to CAP_MKDIRAT.
	Renamed CAP_MKFIFO to CAP_MKFIFOAT.
	Renamed CAP_MKNODE to CAP_MKNODEAT.

	CAP_READ old behaviour:
	- Allow pread(2).
	- Disallow read(2), readv(2) (if there is no CAP_SEEK).
	CAP_READ new behaviour:
	- Allow read(2), readv(2).
	- Disallow pread(2) (CAP_SEEK was also required).

	CAP_WRITE old behaviour:
	- Allow pwrite(2).
	- Disallow write(2), writev(2) (if there is no CAP_SEEK).
	CAP_WRITE new behaviour:
	- Allow write(2), writev(2).
	- Disallow pwrite(2) (CAP_SEEK was also required).

	Added convinient defines:

	#define	CAP_PREAD		(CAP_SEEK | CAP_READ)
	#define	CAP_PWRITE		(CAP_SEEK | CAP_WRITE)
	#define	CAP_MMAP_R		(CAP_MMAP | CAP_SEEK | CAP_READ)
	#define	CAP_MMAP_W		(CAP_MMAP | CAP_SEEK | CAP_WRITE)
	#define	CAP_MMAP_X		(CAP_MMAP | CAP_SEEK | 0x0000000000000008ULL)
	#define	CAP_MMAP_RW		(CAP_MMAP_R | CAP_MMAP_W)
	#define	CAP_MMAP_RX		(CAP_MMAP_R | CAP_MMAP_X)
	#define	CAP_MMAP_WX		(CAP_MMAP_W | CAP_MMAP_X)
	#define	CAP_MMAP_RWX		(CAP_MMAP_R | CAP_MMAP_W | CAP_MMAP_X)
	#define	CAP_RECV		CAP_READ
	#define	CAP_SEND		CAP_WRITE

	#define	CAP_SOCK_CLIENT \
		(CAP_CONNECT | CAP_GETPEERNAME | CAP_GETSOCKNAME | CAP_GETSOCKOPT | \
		 CAP_PEELOFF | CAP_RECV | CAP_SEND | CAP_SETSOCKOPT | CAP_SHUTDOWN)
	#define	CAP_SOCK_SERVER \
		(CAP_ACCEPT | CAP_BIND | CAP_GETPEERNAME | CAP_GETSOCKNAME | \
		 CAP_GETSOCKOPT | CAP_LISTEN | CAP_PEELOFF | CAP_RECV | CAP_SEND | \
		 CAP_SETSOCKOPT | CAP_SHUTDOWN)

	Added defines for backward API compatibility:

	#define	CAP_MAPEXEC		CAP_MMAP_X
	#define	CAP_DELETE		CAP_UNLINKAT
	#define	CAP_MKDIR		CAP_MKDIRAT
	#define	CAP_RMDIR		CAP_UNLINKAT
	#define	CAP_MKFIFO		CAP_MKFIFOAT
	#define	CAP_MKNOD		CAP_MKNODAT
	#define	CAP_SOCK_ALL		(CAP_SOCK_CLIENT | CAP_SOCK_SERVER)

Sponsored by:	The FreeBSD Foundation
Reviewed by:	Christoph Mallon <christoph.mallon@gmx.de>
Many aspects discussed with:	rwatson, benl, jonathan
ABI compatibility discussed with:	kib
2013-03-02 00:53:12 +00:00
Sergey Kandaurov
ab15d8039e Add support of passing SCM_BINTIME ancillary data object for PF_LOCAL
sockets.

PR:		kern/175883
Submitted by:	Andrey Simonenko <simon@comsys.ntu-kpi.kiev.ua>
Discussed with:	glebius, phk
MFC after:	2 weeks
2013-02-15 13:00:20 +00:00
Pawel Jakub Dawidek
6e0b674628 Configure UMA warnings for the following zones:
- unp_zone: kern.ipc.maxsockets limit reached
- socket_zone: kern.ipc.maxsockets limit reached
- zone_mbuf: kern.ipc.nmbufs limit reached
- zone_clust: kern.ipc.nmbclusters limit reached
- zone_jumbop: kern.ipc.nmbjumbop limit reached
- zone_jumbo9: kern.ipc.nmbjumbo9 limit reached
- zone_jumbo16: kern.ipc.nmbjumbo16 limit reached

Note that those warnings are printed not often than every five minutes and can
be globally turned off by setting sysctl/tunable vm.zone_warnings to 0.

Discussed on:	arch
Obtained from:	WHEEL Systems
MFC after:	2 weeks
2012-12-07 22:30:30 +00:00
Konstantin Belousov
daee0f0b0b Schedule garbage collection run for the in-flight rights passed over
the unix domain sockets to the next tick, coalescing the serial calls
until the collection fires.  The thought is that more work for the
collector could arise in the near time, allowing to clean more and not
spend too much CPU on repeated collection when there is no garbage.

Currently the collection task is fired immediately upon unix domain
socket close if there are any rights in flight, which caused excessive
CPU usage and too long blocking of the threads waiting for
unp_list_lock and unp_link_rwlock in write mode.

Robert noted that it would be nice if we could find some heuristic by
which we decide whether to run GC a bit more quickly.  E.g., if the
number of UNIX domain sockets is close to its resource limit, but not
quite.

Reported and tested by:	Markus Gebert <markus.gebert@hostpoint.ch>
Reviewed by:	rwatson
MFC after:	2 weeks
2012-11-20 15:45:48 +00:00
Gleb Smirnoff
716963cb5d Update comment. 2012-11-16 14:00:54 +00:00
Konstantin Belousov
5050aa86cf Remove the support for using non-mpsafe filesystem modules.
In particular, do not lock Giant conditionally when calling into the
filesystem module, remove the VFS_LOCK_GIANT() and related
macros. Stop handling buffers belonging to non-mpsafe filesystems.

The VFS_VERSION is bumped to indicate the interface change which does
not result in the interface signatures changes.

Conducted and reviewed by:	attilio
Tested by:	pho
2012-10-22 17:50:54 +00:00
Matthew D Fleming
fc8fdae0df Fix up kernel sources to be ready for a 64-bit ino_t.
Original code by:	Gleb Kurtsou
2012-09-27 23:30:49 +00:00
Gleb Smirnoff
aaf6343576 Supply the pr_ctloutput method for local datagram sockets,
so that setsockopt() and getsockopt() work on them.

This makes 'tools/regression/sockets/unix_cmsg -t dgram'
more successful.
2012-09-07 21:06:54 +00:00
Pawel Jakub Dawidek
620216725a When checking if file descriptor number is valid, explicitely check for 'fd'
being less than 0 instead of using cast-to-unsigned hack.

Today's commit was brought to you by the letters 'B', 'D' and 'E' :)
2012-06-13 22:12:10 +00:00
Mikolaj Golub
c7e41c8b50 Introduce VOP_UNP_BIND(), VOP_UNP_CONNECT(), and VOP_UNP_DETACH()
operations for setting and accessing vnode's v_socket field.

The operations are necessary to implement proper unix socket handling
on layered file systems like nullfs(5).

This change fixes the long standing issue with nullfs(5) being in that
unix sockets did not work between lower and upper layers: if we bound
to a socket on the lower layer we could connect only to the lower
path; if we bound to the upper layer we could connect only to the
upper path. The new behavior is one can connect to both the lower and
the upper paths regardless what layer path one binds to.

PR:		kern/51583, kern/159663
Suggested by:	kib
Reviewed by:	arch
MFC after:	2 weeks
2012-02-29 21:38:31 +00:00
Mikolaj Golub
662c901c54 When detaching an unix domain socket, uipc_detach() checks
unp->unp_vnode pointer to detect if there is a vnode associated with
(binded to) this socket and does necessary cleanup if there is.

The issue is that after forced unmount this check may be too late as
the unp_vnode is reclaimed and the reference is stale.

To fix this provide a helper function that is called on a socket vnode
reclamation to do necessary cleanup.

Pointed by:	kib
Reviewed by:	kib
MFC after:	2 weeks
2012-02-25 10:15:41 +00:00
Mikolaj Golub
a95852edf3 unp_connect() may use a shared lock on the vnode to fetch the socket.
Suggested by:	jhb
Reviewed by:	jhb, kib, rwatson
MFC after:	2 weeks
2012-02-21 19:40:13 +00:00
Ed Schouten
6472ac3d8a Mark all SYSCTL_NODEs static that have no corresponding SYSCTL_DECLs.
The SYSCTL_NODE macro defines a list that stores all child-elements of
that node. If there's no SYSCTL_DECL macro anywhere else, there's no
reason why it shouldn't be static.
2011-11-07 15:43:11 +00:00
Bjoern A. Zeeb
a06534c3c2 Fix handling of corrupt compress(1)ed data. [11:04]
Add missing length checks on unix socket addresses. [11:05]

Approved by:	so (cperciva)
Approved by:	re (kensmith)
Security:	FreeBSD-SA-11:04.compress
Security:	CVE-2011-2895 [11:04]
Security:	FreeBSD-SA-11:05.unix
2011-09-28 08:47:17 +00:00
Konstantin Belousov
aab4f50170 Prevent the hiwatermark for the unix domain socket from becoming
effectively negative. Often seen as upstream fastcgi connection timeouts
in nginx when using sendfile over unix domain sockets for communication.

Sendfile(2) may send more bytes then currently allowed by the
hiwatermark of the socket, e.g. because the so_snd sockbuf lock is
dropped after sbspace() call in the kern_sendfile() loop. In this case,
recalculated hiwatermark will overflow. Since lowatermark is renewed
as half of the hiwatermark by sendfile code, and both are unsigned,
the send buffer never reaches the free space requested by lowatermark,
causing indefinite wait in sendfile.

Reviewed by:	rwatson
Approved by:	re (bz)
MFC after:	2 weeks
2011-08-20 16:12:29 +00:00
Bjoern A. Zeeb
1fb51a12f2 Mfp4 CH=177274,177280,177284-177285,177297,177324-177325
VNET socket push back:
  try to minimize the number of places where we have to switch vnets
  and narrow down the time we stay switched.  Add assertions to the
  socket code to catch possibly unset vnets as seen in r204147.

  While this reduces the number of vnet recursion in some places like
  NFS, POSIX local sockets and some netgraph, .. recursions are
  impossible to fix.

  The current expectations are documented at the beginning of
  uipc_socket.c along with the other information there.

  Sponsored by: The FreeBSD Foundation
  Sponsored by: CK Software GmbH
  Reviewed by:  jhb
  Tested by:    zec

Tested by:	Mikolaj Golub (to.my.trociny gmail.com)
MFC after:	2 weeks
2011-02-16 21:29:13 +00:00
Konstantin Belousov
f7780c61e7 The unp_gc() function drops and reaquires lock between scan and
collect phases.  The unp_discard() function executes
unp_externalize_fp(), which might make the socket eligible for gc-ing,
and then, later, taskqueue will close the socket.  Since unp_gc()
dropped the list lock to do the malloc, close might happen after the
mark step but before the collection step, causing collection to not
find the socket and miss one array element.

I believe that the race was there before r216158, but the stated
revision made the window much wider by postponing the close to
taskqueue sometimes.

Only process as much array elements as we find the sockets during
second phase of gc [1].  Take linkage lock and recheck the eligibility
of the socket for gc, as well as call fhold() under the linkage lock.

Reported and tested by:	jmallett
Submitted by:   jmallett [1]
Reviewed by:	rwatson, jeff (possibly)
MFC after:	1 week
2011-02-01 13:33:49 +00:00
Matthew D Fleming
2fee06f087 Specify a CTLTYPE_FOO so that a future sysctl(8) change does not need
to rely on the format string.
2011-01-18 21:14:18 +00:00
Konstantin Belousov
9f4ba450f2 Trim whitespaces at the end of lines. Use the commit to record
proper log message for r216150.

MFC after:	1 week

If unix socket has a unix socket attached as the rights that has a
unix socket attached as the rights that has a unix socket attached as
the rights ... Kernel may overflow the stack on attempt to close such
socket.

Only close the rights file in the context of the current close if the
file is not unix domain socket. Otherwise, postpone the work to
taskqueue, preventing unlimited recursion.

The pass of the unix domain sockets over the SCM_RIGHTS message
control is not widely used, and more, the close of the socket with
still attached rights is mostly an application failure. The change
should not affect the performance of typical users of SCM_RIGHTS.

Reviewed by:	jeff, rwatson
2010-12-03 20:39:06 +00:00
Konstantin Belousov
0cb64678bc Reviewed by: jeff, rwatson
MFC after:	1 week
2010-12-03 16:15:44 +00:00
Edward Tomasz Napierala
175389cff2 Remove spurious '/*-' marks and fix some other style problems.
Submitted by:	bde@
2010-07-22 05:42:29 +00:00
Edward Tomasz Napierala
1a996ed1d8 Revert r210225 - turns out I was wrong; the "/*-" is not license-only
thing; it's also used to indicate that the comment should not be automatically
rewrapped.

Explained by:	cperciva@
2010-07-18 20:57:53 +00:00
Edward Tomasz Napierala
805cc58ac0 The "/*-" comment marker is supposed to denote copyrights. Remove non-copyright
occurences from sys/sys/ and sys/kern/.
2010-07-18 20:23:10 +00:00
Robert Watson
604f19c91e Fix build on amd64, where sysctl arg1 is a pointer.
Reported by:	Mr Tinderbox
MFC after:	3 months
2009-10-05 22:23:12 +00:00
Robert Watson
84d61770bc First cut at implementing SOCK_SEQPACKET support for UNIX (local) domain
sockets.  This allows for reliable bi-directional datagram communication
over UNIX domain sockets, in contrast to SOCK_DGRAM (M:N, unreliable) or
SOCK_STERAM (bi-directional bytestream).  Largely, this reuses existing
UNIX domain socket code.  This allows applications requiring record-
oriented semantics to do so reliably via local IPC.

Some implementation notes (also present in XXX comments):

- Currently we lack an sbappend variant able to do datagrams and control
  data without doing addresses, so we mark SOCK_SEQPACKET as PR_ADDR.
  Adding a new variant will solve this problem.

- UNIX domain sockets on FreeBSD provide back-pressure/flow control
  notification for stream sockets by manipulating the send socket
  buffer's size during pru_send and pru_rcvd.  This trick works less well
  for SOCK_SEQPACKET as sosend_generic() uses sb_hiwat not just to
  manage blocking, but also to determine maximum datagram size.  Fixing
  this requires rethinking how back-pressure is done for SOCK_SEQPACKET;
  in the mean time, it's possible to get EMSGSIZE when buffers fill,
  instead of blocking.

Discussed with:	benl
Reviewed by:	bz, rpaulo
MFC after:	3 months
Sponsored by:	Google
2009-10-05 14:49:16 +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
Jamie Gritton
399645e1b9 Remove unnecessary/redundant includes.
Approved by:	bz (mentor)
2009-06-23 14:39:21 +00:00
John Baldwin
afd9f91c63 Fix a deadlock in the getpeername() method for UNIX domain sockets.
Instead of locking the local unp followed by the remote unp, use the same
locking model as accept() and read lock the global link lock followed by
the remote unp while fetching the remote sockaddr.

Reported by:	Mel Flynn  mel.flynn of mailing.thruhere.net
Reviewed by:	rwatson
MFC after:	1 week
2009-06-18 20:56:22 +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
Robert Watson
f93bfb23dc Add internal 'mac_policy_count' counter to the MAC Framework, which is a
count of the number of registered policies.

Rather than unconditionally locking sockets before passing them into MAC,
lock them in the MAC entry points only if mac_policy_count is non-zero.

This avoids locking overhead for a number of socket system calls when no
policies are registered, eliminating measurable overhead for the MAC
Framework for the socket subsystem when there are no active policies.

Possibly socket locks should be acquired by policies if they are required
for socket labels, which would further avoid locking overhead when there
are policies but they don't require labeling of sockets, or possibly
don't even implement socket controls.

Obtained from:	TrustedBSD Project
2009-06-02 18:26:17 +00:00
Marko Zec
21ca7b57bd Change the curvnet variable from a global const struct vnet *,
previously always pointing to the default vnet context, to a
dynamically changing thread-local one.  The currvnet context
should be set on entry to networking code via CURVNET_SET() macros,
and reverted to previous state via CURVNET_RESTORE().  Recursions
on curvnet are permitted, though strongly discuouraged.

This change should have no functional impact on nooptions VIMAGE
kernel builds, where CURVNET_* macros expand to whitespace.

The curthread->td_vnet (aka curvnet) variable's purpose is to be an
indicator of the vnet context in which the current network-related
operation takes place, in case we cannot deduce the current vnet
context from any other source, such as by looking at mbuf's
m->m_pkthdr.rcvif->if_vnet, sockets's so->so_vnet etc.  Moreover, so
far curvnet has turned out to be an invaluable consistency checking
aid: it helps to catch cases when sockets, ifnets or any other
vnet-aware structures may have leaked from one vnet to another.

The exact placement of the CURVNET_SET() / CURVNET_RESTORE() macros
was a result of an empirical iterative process, whith an aim to
reduce recursions on CURVNET_SET() to a minimum, while still reducing
the scope of CURVNET_SET() to networking only operations - the
alternative would be calling CURVNET_SET() on each system call entry.
In general, curvnet has to be set in three typicall cases: when
processing socket-related requests from userspace or from within the
kernel; when processing inbound traffic flowing from device drivers
to upper layers of the networking stack, and when executing
timer-driven networking functions.

This change also introduces a DDB subcommand to show the list of all
vnet instances.

Approved by:	julian (mentor)
2009-05-05 10:56:12 +00:00
Robert Watson
885868cd8f Remove VOP_LEASE and supporting functions. This hasn't been used since
the removal of NQNFS, but was left in in case it was required for NFSv4.
Since our new NFSv4 client and server can't use it for their
requirements, GC the old mechanism, as well as other unused lease-
related code and interfaces.

Due to its impact on kernel programming and binary interfaces, this
change should not be MFC'd.

Proposed by:    jeff
Reviewed by:    jeff
Discussed with: rmacklem, zach loafman @ isilon
2009-04-10 10:52:19 +00:00
Robert Watson
3dab55bc86 Decompose the global UNIX domain sockets rwlock into two different
locks: a global list/counter/generation counter protected by a new
mutex unp_list_lock, and a global linkage rwlock, unp_global_rwlock,
which protects the connections between UNIX domain sockets.

This eliminates conditional lock acquisition that was previously a
property of the global lock being held over sonewconn() leading to a
call to uipc_attach(), which also required the global lock, but
couldn't rely on it as other paths existed to uipc_attach() that
didn't hold it: now uipc_attach() uses only the list lock, which
follows the linkage lock in the lock order.  It may also reduce
contention on the global lock for some workloads.

Add global UNIX domain socket locks to hard-coded witness lock
order.

MFC after:	1 week
Discussed with:	kris
2009-03-08 21:48:29 +00:00
Robert Watson
b523ec24b9 White space and comment tweaks.
MFC after:	3 weeks
2009-01-01 20:03:22 +00:00
Robert Watson
a9f3c7d2ff Rename mbcnt to mbcnt_delta in uipc_send() -- unlike other local
variables named mbcnt in uipc_usrreq.c, this instance is a delta
rather than a cache of sb_mbcnt.

MFC after:	3 weeks
2008-12-30 16:09:57 +00:00
Dag-Erling Smørgrav
1ede983cc9 Retire the MALLOC and FREE macros. They are an abomination unto style(9).
MFC after:	3 months
2008-10-23 15:53:51 +00:00
Robert Watson
4b0e2b9add Remove stale comment: while uipc_connect2() was, until recently, not
static so it could be used by fifofs (actually portalfs), it is now
static.

Submitted by:	kensmith
2008-10-11 17:28:22 +00:00
Robert Watson
e298cf5902 Remove stale comment (and XXX saying so) about why we zero the file
descriptor pointer in unp_freerights: we can no longer recurse into
unp_gc due to unp_gc being invoked in a deferred way, but it's still
a good idea.

MFC after:	3 days
2008-10-08 06:26:51 +00:00