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WSL2-Linux-Kernel/net/vmw_vsock/af_vsock.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* VMware vSockets Driver
*
* Copyright (C) 2007-2013 VMware, Inc. All rights reserved.
*/
/* Implementation notes:
*
* - There are two kinds of sockets: those created by user action (such as
* calling socket(2)) and those created by incoming connection request packets.
*
* - There are two "global" tables, one for bound sockets (sockets that have
* specified an address that they are responsible for) and one for connected
* sockets (sockets that have established a connection with another socket).
* These tables are "global" in that all sockets on the system are placed
* within them. - Note, though, that the bound table contains an extra entry
* for a list of unbound sockets and SOCK_DGRAM sockets will always remain in
* that list. The bound table is used solely for lookup of sockets when packets
* are received and that's not necessary for SOCK_DGRAM sockets since we create
* a datagram handle for each and need not perform a lookup. Keeping SOCK_DGRAM
* sockets out of the bound hash buckets will reduce the chance of collisions
* when looking for SOCK_STREAM sockets and prevents us from having to check the
* socket type in the hash table lookups.
*
* - Sockets created by user action will either be "client" sockets that
* initiate a connection or "server" sockets that listen for connections; we do
* not support simultaneous connects (two "client" sockets connecting).
*
* - "Server" sockets are referred to as listener sockets throughout this
* implementation because they are in the TCP_LISTEN state. When a
* connection request is received (the second kind of socket mentioned above),
* we create a new socket and refer to it as a pending socket. These pending
* sockets are placed on the pending connection list of the listener socket.
* When future packets are received for the address the listener socket is
* bound to, we check if the source of the packet is from one that has an
* existing pending connection. If it does, we process the packet for the
* pending socket. When that socket reaches the connected state, it is removed
* from the listener socket's pending list and enqueued in the listener
* socket's accept queue. Callers of accept(2) will accept connected sockets
* from the listener socket's accept queue. If the socket cannot be accepted
* for some reason then it is marked rejected. Once the connection is
* accepted, it is owned by the user process and the responsibility for cleanup
* falls with that user process.
*
* - It is possible that these pending sockets will never reach the connected
* state; in fact, we may never receive another packet after the connection
* request. Because of this, we must schedule a cleanup function to run in the
* future, after some amount of time passes where a connection should have been
* established. This function ensures that the socket is off all lists so it
* cannot be retrieved, then drops all references to the socket so it is cleaned
* up (sock_put() -> sk_free() -> our sk_destruct implementation). Note this
* function will also cleanup rejected sockets, those that reach the connected
* state but leave it before they have been accepted.
*
* - Lock ordering for pending or accept queue sockets is:
*
* lock_sock(listener);
* lock_sock_nested(pending, SINGLE_DEPTH_NESTING);
*
* Using explicit nested locking keeps lockdep happy since normally only one
* lock of a given class may be taken at a time.
*
* - Sockets created by user action will be cleaned up when the user process
* calls close(2), causing our release implementation to be called. Our release
* implementation will perform some cleanup then drop the last reference so our
* sk_destruct implementation is invoked. Our sk_destruct implementation will
* perform additional cleanup that's common for both types of sockets.
*
* - A socket's reference count is what ensures that the structure won't be
* freed. Each entry in a list (such as the "global" bound and connected tables
* and the listener socket's pending list and connected queue) ensures a
* reference. When we defer work until process context and pass a socket as our
* argument, we must ensure the reference count is increased to ensure the
* socket isn't freed before the function is run; the deferred function will
* then drop the reference.
*
* - sk->sk_state uses the TCP state constants because they are widely used by
* other address families and exposed to userspace tools like ss(8):
*
* TCP_CLOSE - unconnected
* TCP_SYN_SENT - connecting
* TCP_ESTABLISHED - connected
* TCP_CLOSING - disconnecting
* TCP_LISTEN - listening
*/
#include <linux/types.h>
#include <linux/bitops.h>
#include <linux/cred.h>
#include <linux/init.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/sched/signal.h>
#include <linux/kmod.h>
#include <linux/list.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/net.h>
#include <linux/poll.h>
#include <linux/random.h>
#include <linux/skbuff.h>
#include <linux/smp.h>
#include <linux/socket.h>
#include <linux/stddef.h>
#include <linux/unistd.h>
#include <linux/wait.h>
#include <linux/workqueue.h>
#include <net/sock.h>
#include <net/af_vsock.h>
static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr);
static void vsock_sk_destruct(struct sock *sk);
static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
/* Protocol family. */
static struct proto vsock_proto = {
.name = "AF_VSOCK",
.owner = THIS_MODULE,
.obj_size = sizeof(struct vsock_sock),
};
/* The default peer timeout indicates how long we will wait for a peer response
* to a control message.
*/
#define VSOCK_DEFAULT_CONNECT_TIMEOUT (2 * HZ)
#define VSOCK_DEFAULT_BUFFER_SIZE (1024 * 256)
#define VSOCK_DEFAULT_BUFFER_MAX_SIZE (1024 * 256)
#define VSOCK_DEFAULT_BUFFER_MIN_SIZE 128
/* Transport used for host->guest communication */
static const struct vsock_transport *transport_h2g;
/* Transport used for guest->host communication */
static const struct vsock_transport *transport_g2h;
/* Transport used for DGRAM communication */
static const struct vsock_transport *transport_dgram;
/* Transport used for local communication */
static const struct vsock_transport *transport_local;
static DEFINE_MUTEX(vsock_register_mutex);
/**** UTILS ****/
/* Each bound VSocket is stored in the bind hash table and each connected
* VSocket is stored in the connected hash table.
*
* Unbound sockets are all put on the same list attached to the end of the hash
* table (vsock_unbound_sockets). Bound sockets are added to the hash table in
* the bucket that their local address hashes to (vsock_bound_sockets(addr)
* represents the list that addr hashes to).
*
* Specifically, we initialize the vsock_bind_table array to a size of
* VSOCK_HASH_SIZE + 1 so that vsock_bind_table[0] through
* vsock_bind_table[VSOCK_HASH_SIZE - 1] are for bound sockets and
* vsock_bind_table[VSOCK_HASH_SIZE] is for unbound sockets. The hash function
* mods with VSOCK_HASH_SIZE to ensure this.
*/
#define MAX_PORT_RETRIES 24
#define VSOCK_HASH(addr) ((addr)->svm_port % VSOCK_HASH_SIZE)
#define vsock_bound_sockets(addr) (&vsock_bind_table[VSOCK_HASH(addr)])
#define vsock_unbound_sockets (&vsock_bind_table[VSOCK_HASH_SIZE])
/* XXX This can probably be implemented in a better way. */
#define VSOCK_CONN_HASH(src, dst) \
(((src)->svm_cid ^ (dst)->svm_port) % VSOCK_HASH_SIZE)
#define vsock_connected_sockets(src, dst) \
(&vsock_connected_table[VSOCK_CONN_HASH(src, dst)])
#define vsock_connected_sockets_vsk(vsk) \
vsock_connected_sockets(&(vsk)->remote_addr, &(vsk)->local_addr)
struct list_head vsock_bind_table[VSOCK_HASH_SIZE + 1];
EXPORT_SYMBOL_GPL(vsock_bind_table);
struct list_head vsock_connected_table[VSOCK_HASH_SIZE];
EXPORT_SYMBOL_GPL(vsock_connected_table);
DEFINE_SPINLOCK(vsock_table_lock);
EXPORT_SYMBOL_GPL(vsock_table_lock);
/* Autobind this socket to the local address if necessary. */
static int vsock_auto_bind(struct vsock_sock *vsk)
{
struct sock *sk = sk_vsock(vsk);
struct sockaddr_vm local_addr;
if (vsock_addr_bound(&vsk->local_addr))
return 0;
vsock_addr_init(&local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
return __vsock_bind(sk, &local_addr);
}
static void vsock_init_tables(void)
{
int i;
for (i = 0; i < ARRAY_SIZE(vsock_bind_table); i++)
INIT_LIST_HEAD(&vsock_bind_table[i]);
for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++)
INIT_LIST_HEAD(&vsock_connected_table[i]);
}
static void __vsock_insert_bound(struct list_head *list,
struct vsock_sock *vsk)
{
sock_hold(&vsk->sk);
list_add(&vsk->bound_table, list);
}
static void __vsock_insert_connected(struct list_head *list,
struct vsock_sock *vsk)
{
sock_hold(&vsk->sk);
list_add(&vsk->connected_table, list);
}
static void __vsock_remove_bound(struct vsock_sock *vsk)
{
list_del_init(&vsk->bound_table);
sock_put(&vsk->sk);
}
static void __vsock_remove_connected(struct vsock_sock *vsk)
{
list_del_init(&vsk->connected_table);
sock_put(&vsk->sk);
}
static struct sock *__vsock_find_bound_socket(struct sockaddr_vm *addr)
{
struct vsock_sock *vsk;
list_for_each_entry(vsk, vsock_bound_sockets(addr), bound_table) {
if (vsock_addr_equals_addr(addr, &vsk->local_addr))
return sk_vsock(vsk);
if (addr->svm_port == vsk->local_addr.svm_port &&
(vsk->local_addr.svm_cid == VMADDR_CID_ANY ||
addr->svm_cid == VMADDR_CID_ANY))
return sk_vsock(vsk);
}
return NULL;
}
static struct sock *__vsock_find_connected_socket(struct sockaddr_vm *src,
struct sockaddr_vm *dst)
{
struct vsock_sock *vsk;
list_for_each_entry(vsk, vsock_connected_sockets(src, dst),
connected_table) {
if (vsock_addr_equals_addr(src, &vsk->remote_addr) &&
dst->svm_port == vsk->local_addr.svm_port) {
return sk_vsock(vsk);
}
}
return NULL;
}
static void vsock_insert_unbound(struct vsock_sock *vsk)
{
spin_lock_bh(&vsock_table_lock);
__vsock_insert_bound(vsock_unbound_sockets, vsk);
spin_unlock_bh(&vsock_table_lock);
}
void vsock_insert_connected(struct vsock_sock *vsk)
{
struct list_head *list = vsock_connected_sockets(
&vsk->remote_addr, &vsk->local_addr);
spin_lock_bh(&vsock_table_lock);
__vsock_insert_connected(list, vsk);
spin_unlock_bh(&vsock_table_lock);
}
EXPORT_SYMBOL_GPL(vsock_insert_connected);
void vsock_remove_bound(struct vsock_sock *vsk)
{
spin_lock_bh(&vsock_table_lock);
if (__vsock_in_bound_table(vsk))
__vsock_remove_bound(vsk);
spin_unlock_bh(&vsock_table_lock);
}
EXPORT_SYMBOL_GPL(vsock_remove_bound);
void vsock_remove_connected(struct vsock_sock *vsk)
{
spin_lock_bh(&vsock_table_lock);
if (__vsock_in_connected_table(vsk))
__vsock_remove_connected(vsk);
spin_unlock_bh(&vsock_table_lock);
}
EXPORT_SYMBOL_GPL(vsock_remove_connected);
struct sock *vsock_find_bound_socket(struct sockaddr_vm *addr)
{
struct sock *sk;
spin_lock_bh(&vsock_table_lock);
sk = __vsock_find_bound_socket(addr);
if (sk)
sock_hold(sk);
spin_unlock_bh(&vsock_table_lock);
return sk;
}
EXPORT_SYMBOL_GPL(vsock_find_bound_socket);
struct sock *vsock_find_connected_socket(struct sockaddr_vm *src,
struct sockaddr_vm *dst)
{
struct sock *sk;
spin_lock_bh(&vsock_table_lock);
sk = __vsock_find_connected_socket(src, dst);
if (sk)
sock_hold(sk);
spin_unlock_bh(&vsock_table_lock);
return sk;
}
EXPORT_SYMBOL_GPL(vsock_find_connected_socket);
void vsock_remove_sock(struct vsock_sock *vsk)
{
vsock_remove_bound(vsk);
vsock_remove_connected(vsk);
}
EXPORT_SYMBOL_GPL(vsock_remove_sock);
void vsock_for_each_connected_socket(void (*fn)(struct sock *sk))
{
int i;
spin_lock_bh(&vsock_table_lock);
for (i = 0; i < ARRAY_SIZE(vsock_connected_table); i++) {
struct vsock_sock *vsk;
list_for_each_entry(vsk, &vsock_connected_table[i],
connected_table)
fn(sk_vsock(vsk));
}
spin_unlock_bh(&vsock_table_lock);
}
EXPORT_SYMBOL_GPL(vsock_for_each_connected_socket);
void vsock_add_pending(struct sock *listener, struct sock *pending)
{
struct vsock_sock *vlistener;
struct vsock_sock *vpending;
vlistener = vsock_sk(listener);
vpending = vsock_sk(pending);
sock_hold(pending);
sock_hold(listener);
list_add_tail(&vpending->pending_links, &vlistener->pending_links);
}
EXPORT_SYMBOL_GPL(vsock_add_pending);
void vsock_remove_pending(struct sock *listener, struct sock *pending)
{
struct vsock_sock *vpending = vsock_sk(pending);
list_del_init(&vpending->pending_links);
sock_put(listener);
sock_put(pending);
}
EXPORT_SYMBOL_GPL(vsock_remove_pending);
void vsock_enqueue_accept(struct sock *listener, struct sock *connected)
{
struct vsock_sock *vlistener;
struct vsock_sock *vconnected;
vlistener = vsock_sk(listener);
vconnected = vsock_sk(connected);
sock_hold(connected);
sock_hold(listener);
list_add_tail(&vconnected->accept_queue, &vlistener->accept_queue);
}
EXPORT_SYMBOL_GPL(vsock_enqueue_accept);
static bool vsock_use_local_transport(unsigned int remote_cid)
{
if (!transport_local)
return false;
if (remote_cid == VMADDR_CID_LOCAL)
return true;
if (transport_g2h) {
return remote_cid == transport_g2h->get_local_cid();
} else {
return remote_cid == VMADDR_CID_HOST;
}
}
static void vsock_deassign_transport(struct vsock_sock *vsk)
{
if (!vsk->transport)
return;
vsk->transport->destruct(vsk);
module_put(vsk->transport->module);
vsk->transport = NULL;
}
/* Assign a transport to a socket and call the .init transport callback.
*
* Note: for stream socket this must be called when vsk->remote_addr is set
* (e.g. during the connect() or when a connection request on a listener
* socket is received).
* The vsk->remote_addr is used to decide which transport to use:
* - remote CID == VMADDR_CID_LOCAL or g2h->local_cid or VMADDR_CID_HOST if
* g2h is not loaded, will use local transport;
* - remote CID <= VMADDR_CID_HOST will use guest->host transport;
* - remote CID > VMADDR_CID_HOST will use host->guest transport;
*/
int vsock_assign_transport(struct vsock_sock *vsk, struct vsock_sock *psk)
{
const struct vsock_transport *new_transport;
struct sock *sk = sk_vsock(vsk);
unsigned int remote_cid = vsk->remote_addr.svm_cid;
int ret;
switch (sk->sk_type) {
case SOCK_DGRAM:
new_transport = transport_dgram;
break;
case SOCK_STREAM:
if (vsock_use_local_transport(remote_cid))
new_transport = transport_local;
else if (remote_cid <= VMADDR_CID_HOST)
new_transport = transport_g2h;
else
new_transport = transport_h2g;
break;
default:
return -ESOCKTNOSUPPORT;
}
if (vsk->transport) {
if (vsk->transport == new_transport)
return 0;
/* transport->release() must be called with sock lock acquired.
* This path can only be taken during vsock_stream_connect(),
* where we have already held the sock lock.
* In the other cases, this function is called on a new socket
* which is not assigned to any transport.
*/
vsk->transport->release(vsk);
vsock_deassign_transport(vsk);
}
/* We increase the module refcnt to prevent the transport unloading
* while there are open sockets assigned to it.
*/
if (!new_transport || !try_module_get(new_transport->module))
return -ENODEV;
ret = new_transport->init(vsk, psk);
if (ret) {
module_put(new_transport->module);
return ret;
}
vsk->transport = new_transport;
return 0;
}
EXPORT_SYMBOL_GPL(vsock_assign_transport);
bool vsock_find_cid(unsigned int cid)
{
if (transport_g2h && cid == transport_g2h->get_local_cid())
return true;
if (transport_h2g && cid == VMADDR_CID_HOST)
return true;
if (transport_local && cid == VMADDR_CID_LOCAL)
return true;
return false;
}
EXPORT_SYMBOL_GPL(vsock_find_cid);
static struct sock *vsock_dequeue_accept(struct sock *listener)
{
struct vsock_sock *vlistener;
struct vsock_sock *vconnected;
vlistener = vsock_sk(listener);
if (list_empty(&vlistener->accept_queue))
return NULL;
vconnected = list_entry(vlistener->accept_queue.next,
struct vsock_sock, accept_queue);
list_del_init(&vconnected->accept_queue);
sock_put(listener);
/* The caller will need a reference on the connected socket so we let
* it call sock_put().
*/
return sk_vsock(vconnected);
}
static bool vsock_is_accept_queue_empty(struct sock *sk)
{
struct vsock_sock *vsk = vsock_sk(sk);
return list_empty(&vsk->accept_queue);
}
static bool vsock_is_pending(struct sock *sk)
{
struct vsock_sock *vsk = vsock_sk(sk);
return !list_empty(&vsk->pending_links);
}
static int vsock_send_shutdown(struct sock *sk, int mode)
{
struct vsock_sock *vsk = vsock_sk(sk);
if (!vsk->transport)
return -ENODEV;
return vsk->transport->shutdown(vsk, mode);
}
static void vsock_pending_work(struct work_struct *work)
{
struct sock *sk;
struct sock *listener;
struct vsock_sock *vsk;
bool cleanup;
vsk = container_of(work, struct vsock_sock, pending_work.work);
sk = sk_vsock(vsk);
listener = vsk->listener;
cleanup = true;
lock_sock(listener);
lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
if (vsock_is_pending(sk)) {
vsock_remove_pending(listener, sk);
sk_acceptq_removed(listener);
} else if (!vsk->rejected) {
/* We are not on the pending list and accept() did not reject
* us, so we must have been accepted by our user process. We
* just need to drop our references to the sockets and be on
* our way.
*/
cleanup = false;
goto out;
}
/* We need to remove ourself from the global connected sockets list so
* incoming packets can't find this socket, and to reduce the reference
* count.
*/
vsock_remove_connected(vsk);
sk->sk_state = TCP_CLOSE;
out:
release_sock(sk);
release_sock(listener);
if (cleanup)
sock_put(sk);
sock_put(sk);
sock_put(listener);
}
/**** SOCKET OPERATIONS ****/
static int __vsock_bind_stream(struct vsock_sock *vsk,
struct sockaddr_vm *addr)
{
static u32 port;
struct sockaddr_vm new_addr;
if (!port)
port = LAST_RESERVED_PORT + 1 +
prandom_u32_max(U32_MAX - LAST_RESERVED_PORT);
vsock_addr_init(&new_addr, addr->svm_cid, addr->svm_port);
if (addr->svm_port == VMADDR_PORT_ANY) {
bool found = false;
unsigned int i;
for (i = 0; i < MAX_PORT_RETRIES; i++) {
if (port <= LAST_RESERVED_PORT)
port = LAST_RESERVED_PORT + 1;
new_addr.svm_port = port++;
if (!__vsock_find_bound_socket(&new_addr)) {
found = true;
break;
}
}
if (!found)
return -EADDRNOTAVAIL;
} else {
/* If port is in reserved range, ensure caller
* has necessary privileges.
*/
if (addr->svm_port <= LAST_RESERVED_PORT &&
!capable(CAP_NET_BIND_SERVICE)) {
return -EACCES;
}
if (__vsock_find_bound_socket(&new_addr))
return -EADDRINUSE;
}
vsock_addr_init(&vsk->local_addr, new_addr.svm_cid, new_addr.svm_port);
/* Remove stream sockets from the unbound list and add them to the hash
* table for easy lookup by its address. The unbound list is simply an
* extra entry at the end of the hash table, a trick used by AF_UNIX.
*/
__vsock_remove_bound(vsk);
__vsock_insert_bound(vsock_bound_sockets(&vsk->local_addr), vsk);
return 0;
}
static int __vsock_bind_dgram(struct vsock_sock *vsk,
struct sockaddr_vm *addr)
{
return vsk->transport->dgram_bind(vsk, addr);
}
static int __vsock_bind(struct sock *sk, struct sockaddr_vm *addr)
{
struct vsock_sock *vsk = vsock_sk(sk);
int retval;
/* First ensure this socket isn't already bound. */
if (vsock_addr_bound(&vsk->local_addr))
return -EINVAL;
/* Now bind to the provided address or select appropriate values if
* none are provided (VMADDR_CID_ANY and VMADDR_PORT_ANY). Note that
* like AF_INET prevents binding to a non-local IP address (in most
* cases), we only allow binding to a local CID.
*/
if (addr->svm_cid != VMADDR_CID_ANY && !vsock_find_cid(addr->svm_cid))
return -EADDRNOTAVAIL;
switch (sk->sk_socket->type) {
case SOCK_STREAM:
spin_lock_bh(&vsock_table_lock);
retval = __vsock_bind_stream(vsk, addr);
spin_unlock_bh(&vsock_table_lock);
break;
case SOCK_DGRAM:
retval = __vsock_bind_dgram(vsk, addr);
break;
default:
retval = -EINVAL;
break;
}
return retval;
}
static void vsock_connect_timeout(struct work_struct *work);
static struct sock *__vsock_create(struct net *net,
struct socket *sock,
struct sock *parent,
gfp_t priority,
unsigned short type,
int kern)
{
struct sock *sk;
struct vsock_sock *psk;
struct vsock_sock *vsk;
sk = sk_alloc(net, AF_VSOCK, priority, &vsock_proto, kern);
if (!sk)
return NULL;
sock_init_data(sock, sk);
/* sk->sk_type is normally set in sock_init_data, but only if sock is
* non-NULL. We make sure that our sockets always have a type by
* setting it here if needed.
*/
if (!sock)
sk->sk_type = type;
vsk = vsock_sk(sk);
vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
sk->sk_destruct = vsock_sk_destruct;
sk->sk_backlog_rcv = vsock_queue_rcv_skb;
sock_reset_flag(sk, SOCK_DONE);
INIT_LIST_HEAD(&vsk->bound_table);
INIT_LIST_HEAD(&vsk->connected_table);
vsk->listener = NULL;
INIT_LIST_HEAD(&vsk->pending_links);
INIT_LIST_HEAD(&vsk->accept_queue);
vsk->rejected = false;
vsk->sent_request = false;
vsk->ignore_connecting_rst = false;
vsk->peer_shutdown = 0;
INIT_DELAYED_WORK(&vsk->connect_work, vsock_connect_timeout);
INIT_DELAYED_WORK(&vsk->pending_work, vsock_pending_work);
psk = parent ? vsock_sk(parent) : NULL;
if (parent) {
vsk->trusted = psk->trusted;
vsk->owner = get_cred(psk->owner);
vsk->connect_timeout = psk->connect_timeout;
vsk->buffer_size = psk->buffer_size;
vsk->buffer_min_size = psk->buffer_min_size;
vsk->buffer_max_size = psk->buffer_max_size;
} else {
vsk->trusted = capable(CAP_NET_ADMIN);
vsk->owner = get_current_cred();
vsk->connect_timeout = VSOCK_DEFAULT_CONNECT_TIMEOUT;
vsk->buffer_size = VSOCK_DEFAULT_BUFFER_SIZE;
vsk->buffer_min_size = VSOCK_DEFAULT_BUFFER_MIN_SIZE;
vsk->buffer_max_size = VSOCK_DEFAULT_BUFFER_MAX_SIZE;
}
return sk;
}
static void __vsock_release(struct sock *sk, int level)
{
if (sk) {
struct sock *pending;
struct vsock_sock *vsk;
vsk = vsock_sk(sk);
pending = NULL; /* Compiler warning. */
/* When "level" is SINGLE_DEPTH_NESTING, use the nested
* version to avoid the warning "possible recursive locking
* detected". When "level" is 0, lock_sock_nested(sk, level)
* is the same as lock_sock(sk).
*/
lock_sock_nested(sk, level);
if (vsk->transport)
vsk->transport->release(vsk);
else if (sk->sk_type == SOCK_STREAM)
vsock_remove_sock(vsk);
sock_orphan(sk);
sk->sk_shutdown = SHUTDOWN_MASK;
skb_queue_purge(&sk->sk_receive_queue);
/* Clean up any sockets that never were accepted. */
while ((pending = vsock_dequeue_accept(sk)) != NULL) {
__vsock_release(pending, SINGLE_DEPTH_NESTING);
sock_put(pending);
}
release_sock(sk);
sock_put(sk);
}
}
static void vsock_sk_destruct(struct sock *sk)
{
struct vsock_sock *vsk = vsock_sk(sk);
vsock_deassign_transport(vsk);
/* When clearing these addresses, there's no need to set the family and
* possibly register the address family with the kernel.
*/
vsock_addr_init(&vsk->local_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY, VMADDR_PORT_ANY);
put_cred(vsk->owner);
}
static int vsock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
{
int err;
err = sock_queue_rcv_skb(sk, skb);
if (err)
kfree_skb(skb);
return err;
}
struct sock *vsock_create_connected(struct sock *parent)
{
return __vsock_create(sock_net(parent), NULL, parent, GFP_KERNEL,
parent->sk_type, 0);
}
EXPORT_SYMBOL_GPL(vsock_create_connected);
s64 vsock_stream_has_data(struct vsock_sock *vsk)
{
return vsk->transport->stream_has_data(vsk);
}
EXPORT_SYMBOL_GPL(vsock_stream_has_data);
s64 vsock_stream_has_space(struct vsock_sock *vsk)
{
return vsk->transport->stream_has_space(vsk);
}
EXPORT_SYMBOL_GPL(vsock_stream_has_space);
static int vsock_release(struct socket *sock)
{
__vsock_release(sock->sk, 0);
sock->sk = NULL;
sock->state = SS_FREE;
return 0;
}
static int
vsock_bind(struct socket *sock, struct sockaddr *addr, int addr_len)
{
int err;
struct sock *sk;
struct sockaddr_vm *vm_addr;
sk = sock->sk;
if (vsock_addr_cast(addr, addr_len, &vm_addr) != 0)
return -EINVAL;
lock_sock(sk);
err = __vsock_bind(sk, vm_addr);
release_sock(sk);
return err;
}
static int vsock_getname(struct socket *sock,
struct sockaddr *addr, int peer)
{
int err;
struct sock *sk;
struct vsock_sock *vsk;
struct sockaddr_vm *vm_addr;
sk = sock->sk;
vsk = vsock_sk(sk);
err = 0;
lock_sock(sk);
if (peer) {
if (sock->state != SS_CONNECTED) {
err = -ENOTCONN;
goto out;
}
vm_addr = &vsk->remote_addr;
} else {
vm_addr = &vsk->local_addr;
}
if (!vm_addr) {
err = -EINVAL;
goto out;
}
/* sys_getsockname() and sys_getpeername() pass us a
* MAX_SOCK_ADDR-sized buffer and don't set addr_len. Unfortunately
* that macro is defined in socket.c instead of .h, so we hardcode its
* value here.
*/
BUILD_BUG_ON(sizeof(*vm_addr) > 128);
memcpy(addr, vm_addr, sizeof(*vm_addr));
err = sizeof(*vm_addr);
out:
release_sock(sk);
return err;
}
static int vsock_shutdown(struct socket *sock, int mode)
{
int err;
struct sock *sk;
/* User level uses SHUT_RD (0) and SHUT_WR (1), but the kernel uses
* RCV_SHUTDOWN (1) and SEND_SHUTDOWN (2), so we must increment mode
* here like the other address families do. Note also that the
* increment makes SHUT_RDWR (2) into RCV_SHUTDOWN | SEND_SHUTDOWN (3),
* which is what we want.
*/
mode++;
if ((mode & ~SHUTDOWN_MASK) || !mode)
return -EINVAL;
/* If this is a STREAM socket and it is not connected then bail out
* immediately. If it is a DGRAM socket then we must first kick the
* socket so that it wakes up from any sleeping calls, for example
* recv(), and then afterwards return the error.
*/
sk = sock->sk;
if (sock->state == SS_UNCONNECTED) {
err = -ENOTCONN;
if (sk->sk_type == SOCK_STREAM)
return err;
} else {
sock->state = SS_DISCONNECTING;
err = 0;
}
/* Receive and send shutdowns are treated alike. */
mode = mode & (RCV_SHUTDOWN | SEND_SHUTDOWN);
if (mode) {
lock_sock(sk);
sk->sk_shutdown |= mode;
sk->sk_state_change(sk);
release_sock(sk);
if (sk->sk_type == SOCK_STREAM) {
sock_reset_flag(sk, SOCK_DONE);
vsock_send_shutdown(sk, mode);
}
}
return err;
}
static __poll_t vsock_poll(struct file *file, struct socket *sock,
poll_table *wait)
{
struct sock *sk;
__poll_t mask;
struct vsock_sock *vsk;
sk = sock->sk;
vsk = vsock_sk(sk);
poll_wait(file, sk_sleep(sk), wait);
mask = 0;
if (sk->sk_err)
/* Signify that there has been an error on this socket. */
mask |= EPOLLERR;
/* INET sockets treat local write shutdown and peer write shutdown as a
* case of EPOLLHUP set.
*/
if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
((sk->sk_shutdown & SEND_SHUTDOWN) &&
(vsk->peer_shutdown & SEND_SHUTDOWN))) {
mask |= EPOLLHUP;
}
if (sk->sk_shutdown & RCV_SHUTDOWN ||
vsk->peer_shutdown & SEND_SHUTDOWN) {
mask |= EPOLLRDHUP;
}
if (sock->type == SOCK_DGRAM) {
/* For datagram sockets we can read if there is something in
* the queue and write as long as the socket isn't shutdown for
* sending.
*/
if (!skb_queue_empty_lockless(&sk->sk_receive_queue) ||
(sk->sk_shutdown & RCV_SHUTDOWN)) {
mask |= EPOLLIN | EPOLLRDNORM;
}
if (!(sk->sk_shutdown & SEND_SHUTDOWN))
mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
} else if (sock->type == SOCK_STREAM) {
const struct vsock_transport *transport = vsk->transport;
lock_sock(sk);
/* Listening sockets that have connections in their accept
* queue can be read.
*/
if (sk->sk_state == TCP_LISTEN
&& !vsock_is_accept_queue_empty(sk))
mask |= EPOLLIN | EPOLLRDNORM;
/* If there is something in the queue then we can read. */
if (transport && transport->stream_is_active(vsk) &&
!(sk->sk_shutdown & RCV_SHUTDOWN)) {
bool data_ready_now = false;
int ret = transport->notify_poll_in(
vsk, 1, &data_ready_now);
if (ret < 0) {
mask |= EPOLLERR;
} else {
if (data_ready_now)
mask |= EPOLLIN | EPOLLRDNORM;
}
}
/* Sockets whose connections have been closed, reset, or
* terminated should also be considered read, and we check the
* shutdown flag for that.
*/
if (sk->sk_shutdown & RCV_SHUTDOWN ||
vsk->peer_shutdown & SEND_SHUTDOWN) {
mask |= EPOLLIN | EPOLLRDNORM;
}
/* Connected sockets that can produce data can be written. */
if (sk->sk_state == TCP_ESTABLISHED) {
if (!(sk->sk_shutdown & SEND_SHUTDOWN)) {
bool space_avail_now = false;
int ret = transport->notify_poll_out(
vsk, 1, &space_avail_now);
if (ret < 0) {
mask |= EPOLLERR;
} else {
if (space_avail_now)
/* Remove EPOLLWRBAND since INET
* sockets are not setting it.
*/
mask |= EPOLLOUT | EPOLLWRNORM;
}
}
}
/* Simulate INET socket poll behaviors, which sets
* EPOLLOUT|EPOLLWRNORM when peer is closed and nothing to read,
* but local send is not shutdown.
*/
if (sk->sk_state == TCP_CLOSE || sk->sk_state == TCP_CLOSING) {
if (!(sk->sk_shutdown & SEND_SHUTDOWN))
mask |= EPOLLOUT | EPOLLWRNORM;
}
release_sock(sk);
}
return mask;
}
static int vsock_dgram_sendmsg(struct socket *sock, struct msghdr *msg,
size_t len)
{
int err;
struct sock *sk;
struct vsock_sock *vsk;
struct sockaddr_vm *remote_addr;
const struct vsock_transport *transport;
if (msg->msg_flags & MSG_OOB)
return -EOPNOTSUPP;
/* For now, MSG_DONTWAIT is always assumed... */
err = 0;
sk = sock->sk;
vsk = vsock_sk(sk);
transport = vsk->transport;
lock_sock(sk);
err = vsock_auto_bind(vsk);
if (err)
goto out;
/* If the provided message contains an address, use that. Otherwise
* fall back on the socket's remote handle (if it has been connected).
*/
if (msg->msg_name &&
vsock_addr_cast(msg->msg_name, msg->msg_namelen,
&remote_addr) == 0) {
/* Ensure this address is of the right type and is a valid
* destination.
*/
if (remote_addr->svm_cid == VMADDR_CID_ANY)
remote_addr->svm_cid = transport->get_local_cid();
if (!vsock_addr_bound(remote_addr)) {
err = -EINVAL;
goto out;
}
} else if (sock->state == SS_CONNECTED) {
remote_addr = &vsk->remote_addr;
if (remote_addr->svm_cid == VMADDR_CID_ANY)
remote_addr->svm_cid = transport->get_local_cid();
/* XXX Should connect() or this function ensure remote_addr is
* bound?
*/
if (!vsock_addr_bound(&vsk->remote_addr)) {
err = -EINVAL;
goto out;
}
} else {
err = -EINVAL;
goto out;
}
if (!transport->dgram_allow(remote_addr->svm_cid,
remote_addr->svm_port)) {
err = -EINVAL;
goto out;
}
err = transport->dgram_enqueue(vsk, remote_addr, msg, len);
out:
release_sock(sk);
return err;
}
static int vsock_dgram_connect(struct socket *sock,
struct sockaddr *addr, int addr_len, int flags)
{
int err;
struct sock *sk;
struct vsock_sock *vsk;
struct sockaddr_vm *remote_addr;
sk = sock->sk;
vsk = vsock_sk(sk);
err = vsock_addr_cast(addr, addr_len, &remote_addr);
if (err == -EAFNOSUPPORT && remote_addr->svm_family == AF_UNSPEC) {
lock_sock(sk);
vsock_addr_init(&vsk->remote_addr, VMADDR_CID_ANY,
VMADDR_PORT_ANY);
sock->state = SS_UNCONNECTED;
release_sock(sk);
return 0;
} else if (err != 0)
return -EINVAL;
lock_sock(sk);
err = vsock_auto_bind(vsk);
if (err)
goto out;
if (!vsk->transport->dgram_allow(remote_addr->svm_cid,
remote_addr->svm_port)) {
err = -EINVAL;
goto out;
}
memcpy(&vsk->remote_addr, remote_addr, sizeof(vsk->remote_addr));
sock->state = SS_CONNECTED;
out:
release_sock(sk);
return err;
}
static int vsock_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
size_t len, int flags)
{
struct vsock_sock *vsk = vsock_sk(sock->sk);
return vsk->transport->dgram_dequeue(vsk, msg, len, flags);
}
static const struct proto_ops vsock_dgram_ops = {
.family = PF_VSOCK,
.owner = THIS_MODULE,
.release = vsock_release,
.bind = vsock_bind,
.connect = vsock_dgram_connect,
.socketpair = sock_no_socketpair,
.accept = sock_no_accept,
.getname = vsock_getname,
.poll = vsock_poll,
.ioctl = sock_no_ioctl,
.listen = sock_no_listen,
.shutdown = vsock_shutdown,
.setsockopt = sock_no_setsockopt,
.getsockopt = sock_no_getsockopt,
.sendmsg = vsock_dgram_sendmsg,
.recvmsg = vsock_dgram_recvmsg,
.mmap = sock_no_mmap,
.sendpage = sock_no_sendpage,
};
static int vsock_transport_cancel_pkt(struct vsock_sock *vsk)
{
const struct vsock_transport *transport = vsk->transport;
if (!transport->cancel_pkt)
return -EOPNOTSUPP;
return transport->cancel_pkt(vsk);
}
static void vsock_connect_timeout(struct work_struct *work)
{
struct sock *sk;
struct vsock_sock *vsk;
int cancel = 0;
vsk = container_of(work, struct vsock_sock, connect_work.work);
sk = sk_vsock(vsk);
lock_sock(sk);
if (sk->sk_state == TCP_SYN_SENT &&
(sk->sk_shutdown != SHUTDOWN_MASK)) {
sk->sk_state = TCP_CLOSE;
sk->sk_err = ETIMEDOUT;
sk->sk_error_report(sk);
cancel = 1;
}
release_sock(sk);
if (cancel)
vsock_transport_cancel_pkt(vsk);
sock_put(sk);
}
static int vsock_stream_connect(struct socket *sock, struct sockaddr *addr,
int addr_len, int flags)
{
int err;
struct sock *sk;
struct vsock_sock *vsk;
const struct vsock_transport *transport;
struct sockaddr_vm *remote_addr;
long timeout;
DEFINE_WAIT(wait);
err = 0;
sk = sock->sk;
vsk = vsock_sk(sk);
lock_sock(sk);
/* XXX AF_UNSPEC should make us disconnect like AF_INET. */
switch (sock->state) {
case SS_CONNECTED:
err = -EISCONN;
goto out;
case SS_DISCONNECTING:
err = -EINVAL;
goto out;
case SS_CONNECTING:
/* This continues on so we can move sock into the SS_CONNECTED
* state once the connection has completed (at which point err
* will be set to zero also). Otherwise, we will either wait
* for the connection or return -EALREADY should this be a
* non-blocking call.
*/
err = -EALREADY;
break;
default:
if ((sk->sk_state == TCP_LISTEN) ||
vsock_addr_cast(addr, addr_len, &remote_addr) != 0) {
err = -EINVAL;
goto out;
}
/* Set the remote address that we are connecting to. */
memcpy(&vsk->remote_addr, remote_addr,
sizeof(vsk->remote_addr));
err = vsock_assign_transport(vsk, NULL);
if (err)
goto out;
transport = vsk->transport;
/* The hypervisor and well-known contexts do not have socket
* endpoints.
*/
if (!transport ||
!transport->stream_allow(remote_addr->svm_cid,
remote_addr->svm_port)) {
err = -ENETUNREACH;
goto out;
}
err = vsock_auto_bind(vsk);
if (err)
goto out;
sk->sk_state = TCP_SYN_SENT;
err = transport->connect(vsk);
if (err < 0)
goto out;
/* Mark sock as connecting and set the error code to in
* progress in case this is a non-blocking connect.
*/
sock->state = SS_CONNECTING;
err = -EINPROGRESS;
}
/* The receive path will handle all communication until we are able to
* enter the connected state. Here we wait for the connection to be
* completed or a notification of an error.
*/
timeout = vsk->connect_timeout;
prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
while (sk->sk_state != TCP_ESTABLISHED && sk->sk_err == 0) {
if (flags & O_NONBLOCK) {
/* If we're not going to block, we schedule a timeout
* function to generate a timeout on the connection
* attempt, in case the peer doesn't respond in a
* timely manner. We hold on to the socket until the
* timeout fires.
*/
sock_hold(sk);
schedule_delayed_work(&vsk->connect_work, timeout);
/* Skip ahead to preserve error code set above. */
goto out_wait;
}
release_sock(sk);
timeout = schedule_timeout(timeout);
lock_sock(sk);
if (signal_pending(current)) {
err = sock_intr_errno(timeout);
sk->sk_state = TCP_CLOSE;
sock->state = SS_UNCONNECTED;
vsock_transport_cancel_pkt(vsk);
goto out_wait;
} else if (timeout == 0) {
err = -ETIMEDOUT;
sk->sk_state = TCP_CLOSE;
sock->state = SS_UNCONNECTED;
vsock_transport_cancel_pkt(vsk);
goto out_wait;
}
prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
}
if (sk->sk_err) {
err = -sk->sk_err;
sk->sk_state = TCP_CLOSE;
sock->state = SS_UNCONNECTED;
} else {
err = 0;
}
out_wait:
finish_wait(sk_sleep(sk), &wait);
out:
release_sock(sk);
return err;
}
static int vsock_accept(struct socket *sock, struct socket *newsock, int flags,
bool kern)
{
struct sock *listener;
int err;
struct sock *connected;
struct vsock_sock *vconnected;
long timeout;
DEFINE_WAIT(wait);
err = 0;
listener = sock->sk;
lock_sock(listener);
if (sock->type != SOCK_STREAM) {
err = -EOPNOTSUPP;
goto out;
}
if (listener->sk_state != TCP_LISTEN) {
err = -EINVAL;
goto out;
}
/* Wait for children sockets to appear; these are the new sockets
* created upon connection establishment.
*/
timeout = sock_sndtimeo(listener, flags & O_NONBLOCK);
prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
while ((connected = vsock_dequeue_accept(listener)) == NULL &&
listener->sk_err == 0) {
release_sock(listener);
timeout = schedule_timeout(timeout);
finish_wait(sk_sleep(listener), &wait);
lock_sock(listener);
if (signal_pending(current)) {
err = sock_intr_errno(timeout);
goto out;
} else if (timeout == 0) {
err = -EAGAIN;
goto out;
}
prepare_to_wait(sk_sleep(listener), &wait, TASK_INTERRUPTIBLE);
}
finish_wait(sk_sleep(listener), &wait);
if (listener->sk_err)
err = -listener->sk_err;
if (connected) {
sk_acceptq_removed(listener);
lock_sock_nested(connected, SINGLE_DEPTH_NESTING);
vconnected = vsock_sk(connected);
/* If the listener socket has received an error, then we should
* reject this socket and return. Note that we simply mark the
* socket rejected, drop our reference, and let the cleanup
* function handle the cleanup; the fact that we found it in
* the listener's accept queue guarantees that the cleanup
* function hasn't run yet.
*/
if (err) {
vconnected->rejected = true;
} else {
newsock->state = SS_CONNECTED;
sock_graft(connected, newsock);
}
release_sock(connected);
sock_put(connected);
}
out:
release_sock(listener);
return err;
}
static int vsock_listen(struct socket *sock, int backlog)
{
int err;
struct sock *sk;
struct vsock_sock *vsk;
sk = sock->sk;
lock_sock(sk);
if (sock->type != SOCK_STREAM) {
err = -EOPNOTSUPP;
goto out;
}
if (sock->state != SS_UNCONNECTED) {
err = -EINVAL;
goto out;
}
vsk = vsock_sk(sk);
if (!vsock_addr_bound(&vsk->local_addr)) {
err = -EINVAL;
goto out;
}
sk->sk_max_ack_backlog = backlog;
sk->sk_state = TCP_LISTEN;
err = 0;
out:
release_sock(sk);
return err;
}
static void vsock_update_buffer_size(struct vsock_sock *vsk,
const struct vsock_transport *transport,
u64 val)
{
if (val > vsk->buffer_max_size)
val = vsk->buffer_max_size;
if (val < vsk->buffer_min_size)
val = vsk->buffer_min_size;
if (val != vsk->buffer_size &&
transport && transport->notify_buffer_size)
transport->notify_buffer_size(vsk, &val);
vsk->buffer_size = val;
}
static int vsock_stream_setsockopt(struct socket *sock,
int level,
int optname,
char __user *optval,
unsigned int optlen)
{
int err;
struct sock *sk;
struct vsock_sock *vsk;
const struct vsock_transport *transport;
u64 val;
if (level != AF_VSOCK)
return -ENOPROTOOPT;
#define COPY_IN(_v) \
do { \
if (optlen < sizeof(_v)) { \
err = -EINVAL; \
goto exit; \
} \
if (copy_from_user(&_v, optval, sizeof(_v)) != 0) { \
err = -EFAULT; \
goto exit; \
} \
} while (0)
err = 0;
sk = sock->sk;
vsk = vsock_sk(sk);
transport = vsk->transport;
lock_sock(sk);
switch (optname) {
case SO_VM_SOCKETS_BUFFER_SIZE:
COPY_IN(val);
vsock_update_buffer_size(vsk, transport, val);
break;
case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
COPY_IN(val);
vsk->buffer_max_size = val;
vsock_update_buffer_size(vsk, transport, vsk->buffer_size);
break;
case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
COPY_IN(val);
vsk->buffer_min_size = val;
vsock_update_buffer_size(vsk, transport, vsk->buffer_size);
break;
case SO_VM_SOCKETS_CONNECT_TIMEOUT: {
struct __kernel_old_timeval tv;
COPY_IN(tv);
if (tv.tv_sec >= 0 && tv.tv_usec < USEC_PER_SEC &&
tv.tv_sec < (MAX_SCHEDULE_TIMEOUT / HZ - 1)) {
vsk->connect_timeout = tv.tv_sec * HZ +
DIV_ROUND_UP(tv.tv_usec, (1000000 / HZ));
if (vsk->connect_timeout == 0)
vsk->connect_timeout =
VSOCK_DEFAULT_CONNECT_TIMEOUT;
} else {
err = -ERANGE;
}
break;
}
default:
err = -ENOPROTOOPT;
break;
}
#undef COPY_IN
exit:
release_sock(sk);
return err;
}
static int vsock_stream_getsockopt(struct socket *sock,
int level, int optname,
char __user *optval,
int __user *optlen)
{
int err;
int len;
struct sock *sk;
struct vsock_sock *vsk;
u64 val;
if (level != AF_VSOCK)
return -ENOPROTOOPT;
err = get_user(len, optlen);
if (err != 0)
return err;
#define COPY_OUT(_v) \
do { \
if (len < sizeof(_v)) \
return -EINVAL; \
\
len = sizeof(_v); \
if (copy_to_user(optval, &_v, len) != 0) \
return -EFAULT; \
\
} while (0)
err = 0;
sk = sock->sk;
vsk = vsock_sk(sk);
switch (optname) {
case SO_VM_SOCKETS_BUFFER_SIZE:
val = vsk->buffer_size;
COPY_OUT(val);
break;
case SO_VM_SOCKETS_BUFFER_MAX_SIZE:
val = vsk->buffer_max_size;
COPY_OUT(val);
break;
case SO_VM_SOCKETS_BUFFER_MIN_SIZE:
val = vsk->buffer_min_size;
COPY_OUT(val);
break;
case SO_VM_SOCKETS_CONNECT_TIMEOUT: {
struct __kernel_old_timeval tv;
tv.tv_sec = vsk->connect_timeout / HZ;
tv.tv_usec =
(vsk->connect_timeout -
tv.tv_sec * HZ) * (1000000 / HZ);
COPY_OUT(tv);
break;
}
default:
return -ENOPROTOOPT;
}
err = put_user(len, optlen);
if (err != 0)
return -EFAULT;
#undef COPY_OUT
return 0;
}
static int vsock_stream_sendmsg(struct socket *sock, struct msghdr *msg,
size_t len)
{
struct sock *sk;
struct vsock_sock *vsk;
const struct vsock_transport *transport;
ssize_t total_written;
long timeout;
int err;
struct vsock_transport_send_notify_data send_data;
DEFINE_WAIT_FUNC(wait, woken_wake_function);
sk = sock->sk;
vsk = vsock_sk(sk);
transport = vsk->transport;
total_written = 0;
err = 0;
if (msg->msg_flags & MSG_OOB)
return -EOPNOTSUPP;
lock_sock(sk);
/* Callers should not provide a destination with stream sockets. */
if (msg->msg_namelen) {
err = sk->sk_state == TCP_ESTABLISHED ? -EISCONN : -EOPNOTSUPP;
goto out;
}
/* Send data only if both sides are not shutdown in the direction. */
if (sk->sk_shutdown & SEND_SHUTDOWN ||
vsk->peer_shutdown & RCV_SHUTDOWN) {
err = -EPIPE;
goto out;
}
if (!transport || sk->sk_state != TCP_ESTABLISHED ||
!vsock_addr_bound(&vsk->local_addr)) {
err = -ENOTCONN;
goto out;
}
if (!vsock_addr_bound(&vsk->remote_addr)) {
err = -EDESTADDRREQ;
goto out;
}
/* Wait for room in the produce queue to enqueue our user's data. */
timeout = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
err = transport->notify_send_init(vsk, &send_data);
if (err < 0)
goto out;
while (total_written < len) {
ssize_t written;
add_wait_queue(sk_sleep(sk), &wait);
while (vsock_stream_has_space(vsk) == 0 &&
sk->sk_err == 0 &&
!(sk->sk_shutdown & SEND_SHUTDOWN) &&
!(vsk->peer_shutdown & RCV_SHUTDOWN)) {
/* Don't wait for non-blocking sockets. */
if (timeout == 0) {
err = -EAGAIN;
remove_wait_queue(sk_sleep(sk), &wait);
goto out_err;
}
err = transport->notify_send_pre_block(vsk, &send_data);
if (err < 0) {
remove_wait_queue(sk_sleep(sk), &wait);
goto out_err;
}
release_sock(sk);
timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, timeout);
lock_sock(sk);
if (signal_pending(current)) {
err = sock_intr_errno(timeout);
remove_wait_queue(sk_sleep(sk), &wait);
goto out_err;
} else if (timeout == 0) {
err = -EAGAIN;
remove_wait_queue(sk_sleep(sk), &wait);
goto out_err;
}
}
remove_wait_queue(sk_sleep(sk), &wait);
/* These checks occur both as part of and after the loop
* conditional since we need to check before and after
* sleeping.
*/
if (sk->sk_err) {
err = -sk->sk_err;
goto out_err;
} else if ((sk->sk_shutdown & SEND_SHUTDOWN) ||
(vsk->peer_shutdown & RCV_SHUTDOWN)) {
err = -EPIPE;
goto out_err;
}
err = transport->notify_send_pre_enqueue(vsk, &send_data);
if (err < 0)
goto out_err;
/* Note that enqueue will only write as many bytes as are free
* in the produce queue, so we don't need to ensure len is
* smaller than the queue size. It is the caller's
* responsibility to check how many bytes we were able to send.
*/
written = transport->stream_enqueue(
vsk, msg,
len - total_written);
if (written < 0) {
err = -ENOMEM;
goto out_err;
}
total_written += written;
err = transport->notify_send_post_enqueue(
vsk, written, &send_data);
if (err < 0)
goto out_err;
}
out_err:
if (total_written > 0)
err = total_written;
out:
release_sock(sk);
return err;
}
static int
vsock_stream_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
int flags)
{
struct sock *sk;
struct vsock_sock *vsk;
const struct vsock_transport *transport;
int err;
size_t target;
ssize_t copied;
long timeout;
struct vsock_transport_recv_notify_data recv_data;
DEFINE_WAIT(wait);
sk = sock->sk;
vsk = vsock_sk(sk);
transport = vsk->transport;
err = 0;
lock_sock(sk);
if (!transport || sk->sk_state != TCP_ESTABLISHED) {
/* Recvmsg is supposed to return 0 if a peer performs an
* orderly shutdown. Differentiate between that case and when a
* peer has not connected or a local shutdown occured with the
* SOCK_DONE flag.
*/
if (sock_flag(sk, SOCK_DONE))
err = 0;
else
err = -ENOTCONN;
goto out;
}
if (flags & MSG_OOB) {
err = -EOPNOTSUPP;
goto out;
}
/* We don't check peer_shutdown flag here since peer may actually shut
* down, but there can be data in the queue that a local socket can
* receive.
*/
if (sk->sk_shutdown & RCV_SHUTDOWN) {
err = 0;
goto out;
}
/* It is valid on Linux to pass in a zero-length receive buffer. This
* is not an error. We may as well bail out now.
*/
if (!len) {
err = 0;
goto out;
}
/* We must not copy less than target bytes into the user's buffer
* before returning successfully, so we wait for the consume queue to
* have that much data to consume before dequeueing. Note that this
* makes it impossible to handle cases where target is greater than the
* queue size.
*/
target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
if (target >= transport->stream_rcvhiwat(vsk)) {
err = -ENOMEM;
goto out;
}
timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
copied = 0;
err = transport->notify_recv_init(vsk, target, &recv_data);
if (err < 0)
goto out;
while (1) {
s64 ready;
prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
ready = vsock_stream_has_data(vsk);
if (ready == 0) {
if (sk->sk_err != 0 ||
(sk->sk_shutdown & RCV_SHUTDOWN) ||
(vsk->peer_shutdown & SEND_SHUTDOWN)) {
finish_wait(sk_sleep(sk), &wait);
break;
}
/* Don't wait for non-blocking sockets. */
if (timeout == 0) {
err = -EAGAIN;
finish_wait(sk_sleep(sk), &wait);
break;
}
err = transport->notify_recv_pre_block(
vsk, target, &recv_data);
if (err < 0) {
finish_wait(sk_sleep(sk), &wait);
break;
}
release_sock(sk);
timeout = schedule_timeout(timeout);
lock_sock(sk);
if (signal_pending(current)) {
err = sock_intr_errno(timeout);
finish_wait(sk_sleep(sk), &wait);
break;
} else if (timeout == 0) {
err = -EAGAIN;
finish_wait(sk_sleep(sk), &wait);
break;
}
} else {
ssize_t read;
finish_wait(sk_sleep(sk), &wait);
if (ready < 0) {
/* Invalid queue pair content. XXX This should
* be changed to a connection reset in a later
* change.
*/
err = -ENOMEM;
goto out;
}
err = transport->notify_recv_pre_dequeue(
vsk, target, &recv_data);
if (err < 0)
break;
read = transport->stream_dequeue(
vsk, msg,
len - copied, flags);
if (read < 0) {
err = -ENOMEM;
break;
}
copied += read;
err = transport->notify_recv_post_dequeue(
vsk, target, read,
!(flags & MSG_PEEK), &recv_data);
if (err < 0)
goto out;
if (read >= target || flags & MSG_PEEK)
break;
target -= read;
}
}
if (sk->sk_err)
err = -sk->sk_err;
else if (sk->sk_shutdown & RCV_SHUTDOWN)
err = 0;
if (copied > 0)
err = copied;
out:
release_sock(sk);
return err;
}
static const struct proto_ops vsock_stream_ops = {
.family = PF_VSOCK,
.owner = THIS_MODULE,
.release = vsock_release,
.bind = vsock_bind,
.connect = vsock_stream_connect,
.socketpair = sock_no_socketpair,
.accept = vsock_accept,
.getname = vsock_getname,
.poll = vsock_poll,
.ioctl = sock_no_ioctl,
.listen = vsock_listen,
.shutdown = vsock_shutdown,
.setsockopt = vsock_stream_setsockopt,
.getsockopt = vsock_stream_getsockopt,
.sendmsg = vsock_stream_sendmsg,
.recvmsg = vsock_stream_recvmsg,
.mmap = sock_no_mmap,
.sendpage = sock_no_sendpage,
};
static int vsock_create(struct net *net, struct socket *sock,
int protocol, int kern)
{
struct vsock_sock *vsk;
struct sock *sk;
int ret;
if (!sock)
return -EINVAL;
if (protocol && protocol != PF_VSOCK)
return -EPROTONOSUPPORT;
switch (sock->type) {
case SOCK_DGRAM:
sock->ops = &vsock_dgram_ops;
break;
case SOCK_STREAM:
sock->ops = &vsock_stream_ops;
break;
default:
return -ESOCKTNOSUPPORT;
}
sock->state = SS_UNCONNECTED;
sk = __vsock_create(net, sock, NULL, GFP_KERNEL, 0, kern);
if (!sk)
return -ENOMEM;
vsk = vsock_sk(sk);
if (sock->type == SOCK_DGRAM) {
ret = vsock_assign_transport(vsk, NULL);
if (ret < 0) {
sock_put(sk);
return ret;
}
}
vsock_insert_unbound(vsk);
return 0;
}
static const struct net_proto_family vsock_family_ops = {
.family = AF_VSOCK,
.create = vsock_create,
.owner = THIS_MODULE,
};
static long vsock_dev_do_ioctl(struct file *filp,
unsigned int cmd, void __user *ptr)
{
u32 __user *p = ptr;
u32 cid = VMADDR_CID_ANY;
int retval = 0;
switch (cmd) {
case IOCTL_VM_SOCKETS_GET_LOCAL_CID:
/* To be compatible with the VMCI behavior, we prioritize the
* guest CID instead of well-know host CID (VMADDR_CID_HOST).
*/
if (transport_g2h)
cid = transport_g2h->get_local_cid();
else if (transport_h2g)
cid = transport_h2g->get_local_cid();
if (put_user(cid, p) != 0)
retval = -EFAULT;
break;
default:
pr_err("Unknown ioctl %d\n", cmd);
retval = -EINVAL;
}
return retval;
}
static long vsock_dev_ioctl(struct file *filp,
unsigned int cmd, unsigned long arg)
{
return vsock_dev_do_ioctl(filp, cmd, (void __user *)arg);
}
#ifdef CONFIG_COMPAT
static long vsock_dev_compat_ioctl(struct file *filp,
unsigned int cmd, unsigned long arg)
{
return vsock_dev_do_ioctl(filp, cmd, compat_ptr(arg));
}
#endif
static const struct file_operations vsock_device_ops = {
.owner = THIS_MODULE,
.unlocked_ioctl = vsock_dev_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = vsock_dev_compat_ioctl,
#endif
.open = nonseekable_open,
};
static struct miscdevice vsock_device = {
.name = "vsock",
.fops = &vsock_device_ops,
};
static int __init vsock_init(void)
{
int err = 0;
vsock_init_tables();
vsock_proto.owner = THIS_MODULE;
vsock_device.minor = MISC_DYNAMIC_MINOR;
err = misc_register(&vsock_device);
if (err) {
pr_err("Failed to register misc device\n");
goto err_reset_transport;
}
err = proto_register(&vsock_proto, 1); /* we want our slab */
if (err) {
pr_err("Cannot register vsock protocol\n");
goto err_deregister_misc;
}
err = sock_register(&vsock_family_ops);
if (err) {
pr_err("could not register af_vsock (%d) address family: %d\n",
AF_VSOCK, err);
goto err_unregister_proto;
}
return 0;
err_unregister_proto:
proto_unregister(&vsock_proto);
err_deregister_misc:
misc_deregister(&vsock_device);
err_reset_transport:
return err;
}
static void __exit vsock_exit(void)
{
misc_deregister(&vsock_device);
sock_unregister(AF_VSOCK);
proto_unregister(&vsock_proto);
}
const struct vsock_transport *vsock_core_get_transport(struct vsock_sock *vsk)
{
return vsk->transport;
}
EXPORT_SYMBOL_GPL(vsock_core_get_transport);
int vsock_core_register(const struct vsock_transport *t, int features)
{
const struct vsock_transport *t_h2g, *t_g2h, *t_dgram, *t_local;
int err = mutex_lock_interruptible(&vsock_register_mutex);
if (err)
return err;
t_h2g = transport_h2g;
t_g2h = transport_g2h;
t_dgram = transport_dgram;
t_local = transport_local;
if (features & VSOCK_TRANSPORT_F_H2G) {
if (t_h2g) {
err = -EBUSY;
goto err_busy;
}
t_h2g = t;
}
if (features & VSOCK_TRANSPORT_F_G2H) {
if (t_g2h) {
err = -EBUSY;
goto err_busy;
}
t_g2h = t;
}
if (features & VSOCK_TRANSPORT_F_DGRAM) {
if (t_dgram) {
err = -EBUSY;
goto err_busy;
}
t_dgram = t;
}
if (features & VSOCK_TRANSPORT_F_LOCAL) {
if (t_local) {
err = -EBUSY;
goto err_busy;
}
t_local = t;
}
transport_h2g = t_h2g;
transport_g2h = t_g2h;
transport_dgram = t_dgram;
transport_local = t_local;
err_busy:
mutex_unlock(&vsock_register_mutex);
return err;
}
EXPORT_SYMBOL_GPL(vsock_core_register);
void vsock_core_unregister(const struct vsock_transport *t)
{
mutex_lock(&vsock_register_mutex);
if (transport_h2g == t)
transport_h2g = NULL;
if (transport_g2h == t)
transport_g2h = NULL;
if (transport_dgram == t)
transport_dgram = NULL;
if (transport_local == t)
transport_local = NULL;
mutex_unlock(&vsock_register_mutex);
}
EXPORT_SYMBOL_GPL(vsock_core_unregister);
module_init(vsock_init);
module_exit(vsock_exit);
MODULE_AUTHOR("VMware, Inc.");
MODULE_DESCRIPTION("VMware Virtual Socket Family");
MODULE_VERSION("1.0.2.0-k");
MODULE_LICENSE("GPL v2");
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