Commit Graph

31 Commits

Author SHA1 Message Date
Peng Tao 380feae0de vsock: cancel packets when failing to connect
Otherwise we'll leave the packets queued until releasing vsock device.
E.g., if guest is slow to start up, resulting ETIMEDOUT on connect, guest
will get the connect requests from failed host sockets.

Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Jorgen Hansen <jhansen@vmware.com>
Signed-off-by: Peng Tao <bergwolf@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-21 14:41:47 -07:00
David Howells cdfbabfb2f net: Work around lockdep limitation in sockets that use sockets
Lockdep issues a circular dependency warning when AFS issues an operation
through AF_RXRPC from a context in which the VFS/VM holds the mmap_sem.

The theory lockdep comes up with is as follows:

 (1) If the pagefault handler decides it needs to read pages from AFS, it
     calls AFS with mmap_sem held and AFS begins an AF_RXRPC call, but
     creating a call requires the socket lock:

	mmap_sem must be taken before sk_lock-AF_RXRPC

 (2) afs_open_socket() opens an AF_RXRPC socket and binds it.  rxrpc_bind()
     binds the underlying UDP socket whilst holding its socket lock.
     inet_bind() takes its own socket lock:

	sk_lock-AF_RXRPC must be taken before sk_lock-AF_INET

 (3) Reading from a TCP socket into a userspace buffer might cause a fault
     and thus cause the kernel to take the mmap_sem, but the TCP socket is
     locked whilst doing this:

	sk_lock-AF_INET must be taken before mmap_sem

However, lockdep's theory is wrong in this instance because it deals only
with lock classes and not individual locks.  The AF_INET lock in (2) isn't
really equivalent to the AF_INET lock in (3) as the former deals with a
socket entirely internal to the kernel that never sees userspace.  This is
a limitation in the design of lockdep.

Fix the general case by:

 (1) Double up all the locking keys used in sockets so that one set are
     used if the socket is created by userspace and the other set is used
     if the socket is created by the kernel.

 (2) Store the kern parameter passed to sk_alloc() in a variable in the
     sock struct (sk_kern_sock).  This informs sock_lock_init(),
     sock_init_data() and sk_clone_lock() as to the lock keys to be used.

     Note that the child created by sk_clone_lock() inherits the parent's
     kern setting.

 (3) Add a 'kern' parameter to ->accept() that is analogous to the one
     passed in to ->create() that distinguishes whether kernel_accept() or
     sys_accept4() was the caller and can be passed to sk_alloc().

     Note that a lot of accept functions merely dequeue an already
     allocated socket.  I haven't touched these as the new socket already
     exists before we get the parameter.

     Note also that there are a couple of places where I've made the accepted
     socket unconditionally kernel-based:

	irda_accept()
	rds_rcp_accept_one()
	tcp_accept_from_sock()

     because they follow a sock_create_kern() and accept off of that.

Whilst creating this, I noticed that lustre and ocfs don't create sockets
through sock_create_kern() and thus they aren't marked as for-kernel,
though they appear to be internal.  I wonder if these should do that so
that they use the new set of lock keys.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-09 18:23:27 -08:00
Ingo Molnar 174cd4b1e5 sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h>
Fix up affected files that include this signal functionality via sched.h.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:32 +01:00
Jorgen Hansen 1190cfdb1a VSOCK: Don't dec ack backlog twice for rejected connections
If a pending socket is marked as rejected, we will decrease the
sk_ack_backlog twice. So don't decrement it for rejected sockets
in vsock_pending_work().

Testing of the rejected socket path was done through code
modifications.

Reported-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Jorgen Hansen <jhansen@vmware.com>
Reviewed-by: Adit Ranadive <aditr@vmware.com>
Reviewed-by: Aditya Sarwade <asarwade@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-09-27 07:59:25 -04:00
Stefan Hajnoczi 6773b7dc39 VSOCK: defer sock removal to transports
The virtio transport will implement graceful shutdown and the related
SO_LINGER socket option.  This requires orphaning the sock but keeping
it in the table of connections after .release().

This patch adds the vsock_remove_sock() function and leaves it up to the
transport when to remove the sock.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-08-02 02:57:28 +03:00
Stefan Hajnoczi 0b01aeb3d2 VSOCK: transport-specific vsock_transport functions
struct vsock_transport contains function pointers called by AF_VSOCK
core code.  The transport may want its own transport-specific function
pointers and they can be added after struct vsock_transport.

Allow the transport to fetch vsock_transport.  It can downcast it to
access transport-specific function pointers.

The virtio transport will use this.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2016-08-02 02:57:28 +03:00
Stefan Hajnoczi 4192f672fa vsock: make listener child lock ordering explicit
There are several places where the listener and pending or accept queue
child sockets are accessed at the same time.  Lockdep is unhappy that
two locks from the same class are held.

Tell lockdep that it is safe and document the lock ordering.

Originally Claudio Imbrenda <imbrenda@linux.vnet.ibm.com> sent a similar
patch asking whether this is safe.  I have audited the code and also
covered the vsock_pending_work() function.

Suggested-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-27 10:44:46 -04:00
Ian Campbell dedc58e067 VSOCK: do not disconnect socket when peer has shutdown SEND only
The peer may be expecting a reply having sent a request and then done a
shutdown(SHUT_WR), so tearing down the whole socket at this point seems
wrong and breaks for me with a client which does a SHUT_WR.

Looking at other socket family's stream_recvmsg callbacks doing a shutdown
here does not seem to be the norm and removing it does not seem to have
had any adverse effects that I can see.

I'm using Stefan's RFC virtio transport patches, I'm unsure of the impact
on the vmci transport.

Signed-off-by: Ian Campbell <ian.campbell@docker.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Cc: Andy King <acking@vmware.com>
Cc: Dmitry Torokhov <dtor@vmware.com>
Cc: Jorgen Hansen <jhansen@vmware.com>
Cc: Adit Ranadive <aditr@vmware.com>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-05-05 23:31:29 -04:00
Claudio Imbrenda f7f9b5e7f8 AF_VSOCK: Shrink the area influenced by prepare_to_wait
When a thread is prepared for waiting by calling prepare_to_wait, sleeping
is not allowed until either the wait has taken place or finish_wait has
been called.  The existing code in af_vsock imposed unnecessary no-sleep
assumptions to a broad list of backend functions.
This patch shrinks the influence of prepare_to_wait to the area where it
is strictly needed, therefore relaxing the no-sleep restriction there.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-22 16:18:41 -04:00
Claudio Imbrenda 6f57e56a15 Revert "vsock: Fix blocking ops call in prepare_to_wait"
This reverts commit 5988818008 ("vsock: Fix
blocking ops call in prepare_to_wait")

The commit reverted with this patch caused us to potentially miss wakeups.
Since the condition is not checked between the prepare_to_wait and the
schedule(), if a wakeup happens after the condition is checked but before
the sleep happens, we will miss it. ( A description of the problem can be
found here: http://www.makelinux.net/ldd3/chp-6-sect-2 ).

By reverting the patch, the behaviour is still incorrect (since we
shouldn't sleep between the prepare_to_wait and the schedule) but at least
it will not miss wakeups.

The next patch in the series actually fixes the behaviour.

Signed-off-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-03-22 16:18:41 -04:00
Laura Abbott 5988818008 vsock: Fix blocking ops call in prepare_to_wait
We receoved a bug report from someone using vmware:

WARNING: CPU: 3 PID: 660 at kernel/sched/core.c:7389
__might_sleep+0x7d/0x90()
do not call blocking ops when !TASK_RUNNING; state=1 set at
[<ffffffff810fa68d>] prepare_to_wait+0x2d/0x90
Modules linked in: vmw_vsock_vmci_transport vsock snd_seq_midi
snd_seq_midi_event snd_ens1371 iosf_mbi gameport snd_rawmidi
snd_ac97_codec ac97_bus snd_seq coretemp snd_seq_device snd_pcm
snd_timer snd soundcore ppdev crct10dif_pclmul crc32_pclmul
ghash_clmulni_intel vmw_vmci vmw_balloon i2c_piix4 shpchp parport_pc
parport acpi_cpufreq nfsd auth_rpcgss nfs_acl lockd grace sunrpc btrfs
xor raid6_pq 8021q garp stp llc mrp crc32c_intel serio_raw mptspi vmwgfx
drm_kms_helper ttm drm scsi_transport_spi mptscsih e1000 ata_generic
mptbase pata_acpi
CPU: 3 PID: 660 Comm: vmtoolsd Not tainted
4.2.0-0.rc1.git3.1.fc23.x86_64 #1
Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop
Reference Platform, BIOS 6.00 05/20/2014
 0000000000000000 0000000049e617f3 ffff88006ac37ac8 ffffffff818641f5
 0000000000000000 ffff88006ac37b20 ffff88006ac37b08 ffffffff810ab446
 ffff880068009f40 ffffffff81c63bc0 0000000000000061 0000000000000000
Call Trace:
 [<ffffffff818641f5>] dump_stack+0x4c/0x65
 [<ffffffff810ab446>] warn_slowpath_common+0x86/0xc0
 [<ffffffff810ab4d5>] warn_slowpath_fmt+0x55/0x70
 [<ffffffff8112551d>] ? debug_lockdep_rcu_enabled+0x1d/0x20
 [<ffffffff810fa68d>] ? prepare_to_wait+0x2d/0x90
 [<ffffffff810fa68d>] ? prepare_to_wait+0x2d/0x90
 [<ffffffff810da2bd>] __might_sleep+0x7d/0x90
 [<ffffffff812163b3>] __might_fault+0x43/0xa0
 [<ffffffff81430477>] copy_from_iter+0x87/0x2a0
 [<ffffffffa039460a>] __qp_memcpy_to_queue+0x9a/0x1b0 [vmw_vmci]
 [<ffffffffa0394740>] ? qp_memcpy_to_queue+0x20/0x20 [vmw_vmci]
 [<ffffffffa0394757>] qp_memcpy_to_queue_iov+0x17/0x20 [vmw_vmci]
 [<ffffffffa0394d50>] qp_enqueue_locked+0xa0/0x140 [vmw_vmci]
 [<ffffffffa039593f>] vmci_qpair_enquev+0x4f/0xd0 [vmw_vmci]
 [<ffffffffa04847bb>] vmci_transport_stream_enqueue+0x1b/0x20
[vmw_vsock_vmci_transport]
 [<ffffffffa047ae05>] vsock_stream_sendmsg+0x2c5/0x320 [vsock]
 [<ffffffff810fabd0>] ? wake_atomic_t_function+0x70/0x70
 [<ffffffff81702af8>] sock_sendmsg+0x38/0x50
 [<ffffffff81702ff4>] SYSC_sendto+0x104/0x190
 [<ffffffff8126e25a>] ? vfs_read+0x8a/0x140
 [<ffffffff817042ee>] SyS_sendto+0xe/0x10
 [<ffffffff8186d9ae>] entry_SYSCALL_64_fastpath+0x12/0x76

transport->stream_enqueue may call copy_to_user so it should
not be called inside a prepare_to_wait. Narrow the scope of
the prepare_to_wait to avoid the bad call. This also applies
to vsock_stream_recvmsg as well.

Reported-by: Vinson Lee <vlee@freedesktop.org>
Tested-by: Vinson Lee <vlee@freedesktop.org>
Signed-off-by: Laura Abbott <labbott@fedoraproject.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-02-13 05:57:39 -05:00
Stefan Hajnoczi ea3803c193 VSOCK: define VSOCK_SS_LISTEN once only
The SS_LISTEN socket state is defined by both af_vsock.c and
vmci_transport.c.  This is risky since the value could be changed in one
file and the other would be out of sync.

Rename from SS_LISTEN to VSOCK_SS_LISTEN since the constant is not part
of enum socket_state (SS_CONNECTED, ...).  This way it is clear that the
constant is vsock-specific.

The big text reflow in af_vsock.c was necessary to keep to the maximum
line length.  Text is unchanged except for s/SS_LISTEN/VSOCK_SS_LISTEN/.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-11-01 12:14:47 -05:00
Gao feng f6a835bb04 vsock: fix missing cleanup when misc_register failed
reset transport and unlock if misc_register failed.

Signed-off-by: Gao feng <omarapazanadi@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-10-21 07:41:06 -07:00
Eric W. Biederman 11aa9c28b4 net: Pass kern from net_proto_family.create to sk_alloc
In preparation for changing how struct net is refcounted
on kernel sockets pass the knowledge that we are creating
a kernel socket from sock_create_kern through to sk_alloc.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-11 10:50:17 -04:00
Ying Xue 1b78414047 net: Remove iocb argument from sendmsg and recvmsg
After TIPC doesn't depend on iocb argument in its internal
implementations of sendmsg() and recvmsg() hooks defined in proto
structure, no any user is using iocb argument in them at all now.
Then we can drop the redundant iocb argument completely from kinds of
implementations of both sendmsg() and recvmsg() in the entire
networking stack.

Cc: Christoph Hellwig <hch@lst.de>
Suggested-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-03-02 13:06:31 -05:00
Al Viro 0f7db23a07 vmci_transport: switch ->enqeue_dgram, ->enqueue_stream and ->dequeue_stream to msghdr
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-11-24 05:16:42 -05:00
Andy King 2c4a336e0a vsock: Make transport the proto owner
Right now the core vsock module is the owner of the proto family. This
means there's nothing preventing the transport module from unloading if
there are open sockets, which results in a panic. Fix that by allowing
the transport to be the owner, which will refcount it properly.

Includes version bump to 1.0.1.0-k

Passes checkpatch this time, I swear...

Acked-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Andy King <acking@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2014-05-05 13:13:50 -04:00
Hannes Frederic Sowa f3d3342602 net: rework recvmsg handler msg_name and msg_namelen logic
This patch now always passes msg->msg_namelen as 0. recvmsg handlers must
set msg_namelen to the proper size <= sizeof(struct sockaddr_storage)
to return msg_name to the user.

This prevents numerous uninitialized memory leaks we had in the
recvmsg handlers and makes it harder for new code to accidentally leak
uninitialized memory.

Optimize for the case recvfrom is called with NULL as address. We don't
need to copy the address at all, so set it to NULL before invoking the
recvmsg handler. We can do so, because all the recvmsg handlers must
cope with the case a plain read() is called on them. read() also sets
msg_name to NULL.

Also document these changes in include/linux/net.h as suggested by David
Miller.

Changes since RFC:

Set msg->msg_name = NULL if user specified a NULL in msg_name but had a
non-null msg_namelen in verify_iovec/verify_compat_iovec. This doesn't
affect sendto as it would bail out earlier while trying to copy-in the
address. It also more naturally reflects the logic by the callers of
verify_iovec.

With this change in place I could remove "
if (!uaddr || msg_sys->msg_namelen == 0)
	msg->msg_name = NULL
".

This change does not alter the user visible error logic as we ignore
msg_namelen as long as msg_name is NULL.

Also remove two unnecessary curly brackets in ___sys_recvmsg and change
comments to netdev style.

Cc: David Miller <davem@davemloft.net>
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-11-20 21:52:30 -05:00
David S. Miller 2ff1cf12c9 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2013-08-16 15:37:26 -07:00
Julia Lawall d9af2d67e4 net/vmw_vsock/af_vsock.c: drop unneeded semicolon
Drop the semicolon at the end of the list_for_each_entry loop header.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-08-05 11:07:44 -07:00
Asias He 82a54d0ebb VSOCK: Move af_vsock.h and vsock_addr.h to include/net
This is useful for other VSOCK transport implemented outside the
net/vmw_vsock/ directory to use these headers.

Signed-off-by: Asias He <asias@redhat.com>
Acked-by: Andy King <acking@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-07-27 22:14:06 -07:00
Asias He a49dd9dcb5 VSOCK: Fix VSOCK_HASH and VSOCK_CONN_HASH
If we mod with VSOCK_HASH_SIZE -1, we get 0, 1, .... 249.  Actually, we
have vsock_bind_table[0 ... 250] and vsock_connected_table[0 .. 250].
In this case the last entry will never be used.

We should mod with VSOCK_HASH_SIZE instead.

Signed-off-by: Asias He <asias@redhat.com>
Acked-by: Andy King <acking@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-23 23:51:48 -07:00
Asias He b3a6dfe817 VSOCK: Introduce vsock_auto_bind helper
This peace of code is called three times, let's have a helper for it.

Signed-off-by: Asias He <asias@redhat.com>
Acked-by: Andy King <acking@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-06-23 23:51:48 -07:00
Geert Uytterhoeven 22ee3b57c3 VSOCK: Drop bogus __init annotation from vsock_init_tables()
If gcc (e.g. 4.1.2) decides not to inline vsock_init_tables(), this will
cause a section mismatch:

WARNING: net/vmw_vsock/vsock.o(.text+0x1bc): Section mismatch in reference from the function __vsock_core_init() to the function .init.text:vsock_init_tables()
The function __vsock_core_init() references
the function __init vsock_init_tables().
This is often because __vsock_core_init lacks a __init
annotation or the annotation of vsock_init_tables is wrong.

This may cause crashes if VSOCKETS=y and VMWARE_VMCI_VSOCKETS=m.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-25 04:21:51 -04:00
Asias He 6ad0b2f7fd VSOCK: Fix misc device registration
When we call vsock_core_init to init VSOCK the second time,
vsock_device.minor still points to the old dynamically allocated minor
number. misc_register will allocate it for us successfully as if we were
asking for a static one. However, when other user call misc_register to
allocate a dynamic minor number, it will give the one used by
vsock_core_init(), causing this:

  [  405.470687] WARNING: at fs/sysfs/dir.c:536 sysfs_add_one+0xcc/0xf0()
  [  405.470689] Hardware name: OptiPlex 790
  [  405.470690] sysfs: cannot create duplicate filename '/dev/char/10:54'

Always set vsock_device.minor to MISC_DYNAMIC_MINOR before we
register.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Andy King <acking@vmware.com>
Cc: Dmitry Torokhov <dtor@vmware.com>
Cc: Reilly Grant <grantr@vmware.com>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Asias He <asias@redhat.com>
Acked-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-25 04:21:22 -04:00
Mathias Krause d5e0d0f607 VSOCK: Fix missing msg_namelen update in vsock_stream_recvmsg()
The code misses to update the msg_namelen member to 0 and therefore
makes net/socket.c leak the local, uninitialized sockaddr_storage
variable to userland -- 128 bytes of kernel stack memory.

Cc: Andy King <acking@vmware.com>
Cc: Dmitry Torokhov <dtor@vmware.com>
Cc: George Zhang <georgezhang@vmware.com>
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-07 16:28:02 -04:00
Reilly Grant 990454b5a4 VSOCK: Handle changes to the VMCI context ID.
The VMCI context ID of a virtual machine may change at any time. There
is a VMCI event which signals this but datagrams may be processed before
this is handled. It is therefore necessary to be flexible about the
destination context ID of any datagrams received. (It can be assumed to
be correct because it is provided by the hypervisor.) The context ID on
existing sockets should be updated to reflect how the hypervisor is
currently referring to the system.

Signed-off-by: Reilly Grant <grantr@vmware.com>
Acked-by: Andy King <acking@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-04-02 14:39:17 -04:00
Andy King 6cf1c5fc26 VSOCK: Don't reject PF_VSOCK protocol
Allow our own family as the protocol value for socket creation.

Reported-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Andy King <acking@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-18 15:02:51 -05:00
Dmitry Torokhov 7ccd7de691 VSOCK: get rid of vsock_version.h
There isn't really a need to have a separate file for it.

Acked-by: Andy King <acking@vmware.com>
Signed-off-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-18 15:02:51 -05:00
Dmitry Torokhov 7777ac3860 VSOCK: get rid of EXPORT_SYMTAB
This is the default behavior for a looooooong time.

Acked-by: Andy King <acking@vmware.com>
Signed-off-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-18 15:02:51 -05:00
Andy King d021c34405 VSOCK: Introduce VM Sockets
VM Sockets allows communication between virtual machines and the hypervisor.
User level applications both in a virtual machine and on the host can use the
VM Sockets API, which facilitates fast and efficient communication between
guest virtual machines and their host.  A socket address family, designed to be
compatible with UDP and TCP at the interface level, is provided.

Today, VM Sockets is used by various VMware Tools components inside the guest
for zero-config, network-less access to VMware host services.  In addition to
this, VMware's users are using VM Sockets for various applications, where
network access of the virtual machine is restricted or non-existent.  Examples
of this are VMs communicating with device proxies for proprietary hardware
running as host applications and automated testing of applications running
within virtual machines.

The VMware VM Sockets are similar to other socket types, like Berkeley UNIX
socket interface.  The VM Sockets module supports both connection-oriented
stream sockets like TCP, and connectionless datagram sockets like UDP. The VM
Sockets protocol family is defined as "AF_VSOCK" and the socket operations
split for SOCK_DGRAM and SOCK_STREAM.

For additional information about the use of VM Sockets, please refer to the
VM Sockets Programming Guide available at:

https://www.vmware.com/support/developer/vmci-sdk/

Signed-off-by: George Zhang <georgezhang@vmware.com>
Signed-off-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Andy king <acking@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2013-02-10 19:41:08 -05:00