// SPDX-License-Identifier: GPL-2.0-only
/*
* common code for virtio vsock
*
* Copyright (C) 2013-2015 Red Hat, Inc.
* Author: Asias He <[email protected]>
* Stefan Hajnoczi <[email protected]>
*/
#include <linux/spinlock.h>
#include <linux/module.h>
#include <linux/sched/signal.h>
#include <linux/ctype.h>
#include <linux/list.h>
#include <linux/virtio_vsock.h>
#include <uapi/linux/vsockmon.h>
#include <net/sock.h>
#include <net/af_vsock.h>
#define CREATE_TRACE_POINTS
#include <trace/events/vsock_virtio_transport_common.h>
/* How long to wait for graceful shutdown of a connection */
#define VSOCK_CLOSE_TIMEOUT (8 * HZ)
/* Threshold for detecting small packets to copy */
#define GOOD_COPY_LEN 128
static const struct virtio_transport *
virtio_transport_get_ops(struct vsock_sock *vsk)
{
const struct vsock_transport *t = vsock_core_get_transport(vsk);
if (WARN_ON(!t))
return NULL;
return container_of(t, struct virtio_transport, transport);
}
static bool virtio_transport_can_zcopy(const struct virtio_transport *t_ops,
struct virtio_vsock_pkt_info *info,
size_t pkt_len)
{
struct iov_iter *iov_iter;
if (!info->msg)
return false;
iov_iter = &info->msg->msg_iter;
if (iov_iter->iov_offset)
return false;
/* We can't send whole iov. */
if (iov_iter->count > pkt_len)
return false;
/* Check that transport can send data in zerocopy mode. */
t_ops = virtio_transport_get_ops(info->vsk);
if (t_ops->can_msgzerocopy) {
int pages_to_send = iov_iter_npages(iov_iter, MAX_SKB_FRAGS);
/* +1 is for packet header. */
return t_ops->can_msgzerocopy(pages_to_send + 1);
}
return true;
}
static int virtio_transport_init_zcopy_skb(struct vsock_sock *vsk,
struct sk_buff *skb,
struct msghdr *msg,
bool zerocopy)
{
struct ubuf_info *uarg;
if (msg->msg_ubuf) {
uarg = msg->msg_ubuf;
net_zcopy_get(uarg);
} else {
struct iov_iter *iter = &msg->msg_iter;
struct ubuf_info_msgzc *uarg_zc;
uarg = msg_zerocopy_realloc(sk_vsock(vsk),
iter->count,
NULL);
if (!uarg)
return -1;
uarg_zc = uarg_to_msgzc(uarg);
uarg_zc->zerocopy = zerocopy ? 1 : 0;
}
skb_zcopy_init(skb, uarg);
return 0;
}
static int virtio_transport_fill_skb(struct sk_buff *skb,
struct virtio_vsock_pkt_info *info,
size_t len,
bool zcopy)
{
if (zcopy)
return __zerocopy_sg_from_iter(info->msg, NULL, skb,
&info->msg->msg_iter,
len);
return memcpy_from_msg(skb_put(skb, len), info->msg, len);
}
static void virtio_transport_init_hdr(struct sk_buff *skb,
struct virtio_vsock_pkt_info *info,
size_t payload_len,
u32 src_cid,
u32 src_port,
u32 dst_cid,
u32 dst_port)
{
struct virtio_vsock_hdr *hdr;
hdr = virtio_vsock_hdr(skb);
hdr->type = cpu_to_le16(info->type);
hdr->op = cpu_to_le16(info->op);
hdr->src_cid = cpu_to_le64(src_cid);
hdr->dst_cid = cpu_to_le64(dst_cid);
hdr->src_port = cpu_to_le32(src_port);
hdr->dst_port = cpu_to_le32(dst_port);
hdr->flags = cpu_to_le32(info->flags);
hdr->len = cpu_to_le32(payload_len);
hdr->buf_alloc = cpu_to_le32(0);
hdr->fwd_cnt = cpu_to_le32(0);
}
static void virtio_transport_copy_nonlinear_skb(const struct sk_buff *skb,
void *dst,
size_t len)
{
struct iov_iter iov_iter = { 0 };
struct kvec kvec;
size_t to_copy;
kvec.iov_base = dst;
kvec.iov_len = len;
iov_iter.iter_type = ITER_KVEC;
iov_iter.kvec = &kvec;
iov_iter.nr_segs = 1;
to_copy = min_t(size_t, len, skb->len);
skb_copy_datagram_iter(skb, VIRTIO_VSOCK_SKB_CB(skb)->offset,
&iov_iter, to_copy);
}
/* Packet capture */
static struct sk_buff *virtio_transport_build_skb(void *opaque)
{
struct virtio_vsock_hdr *pkt_hdr;
struct sk_buff *pkt = opaque;
struct af_vsockmon_hdr *hdr;
struct sk_buff *skb;
size_t payload_len;
/* A packet could be split to fit the RX buffer, so we can retrieve
* the payload length from the header and the buffer pointer taking
* care of the offset in the original packet.
*/
pkt_hdr = virtio_vsock_hdr(pkt);
payload_len = pkt->len;
skb = alloc_skb(sizeof(*hdr) + sizeof(*pkt_hdr) + payload_len,
GFP_ATOMIC);
if (!skb)
return NULL;
hdr = skb_put(skb, sizeof(*hdr));
/* pkt->hdr is little-endian so no need to byteswap here */
hdr->src_cid = pkt_hdr->src_cid;
hdr->src_port = pkt_hdr->src_port;
hdr->dst_cid = pkt_hdr->dst_cid;
hdr->dst_port = pkt_hdr->dst_port;
hdr->transport = cpu_to_le16(AF_VSOCK_TRANSPORT_VIRTIO);
hdr->len = cpu_to_le16(sizeof(*pkt_hdr));
memset(hdr->reserved, 0, sizeof(hdr->reserved));
switch (le16_to_cpu(pkt_hdr->op)) {
case VIRTIO_VSOCK_OP_REQUEST:
case VIRTIO_VSOCK_OP_RESPONSE:
hdr->op = cpu_to_le16(AF_VSOCK_OP_CONNECT);
break;
case VIRTIO_VSOCK_OP_RST:
case VIRTIO_VSOCK_OP_SHUTDOWN:
hdr->op = cpu_to_le16(AF_VSOCK_OP_DISCONNECT);
break;
case VIRTIO_VSOCK_OP_RW:
hdr->op = cpu_to_le16(AF_VSOCK_OP_PAYLOAD);
break;
case VIRTIO_VSOCK_OP_CREDIT_UPDATE:
case VIRTIO_VSOCK_OP_CREDIT_REQUEST:
hdr->op = cpu_to_le16(AF_VSOCK_OP_CONTROL);
break;
default:
hdr->op = cpu_to_le16(AF_VSOCK_OP_UNKNOWN);
break;
}
skb_put_data(skb, pkt_hdr, sizeof(*pkt_hdr));
if (payload_len) {
if (skb_is_nonlinear(pkt)) {
void *data = skb_put(skb, payload_len);
virtio_transport_copy_nonlinear_skb(pkt, data, payload_len);
} else {
skb_put_data(skb, pkt->data, payload_len);
}
}
return skb;
}
void virtio_transport_deliver_tap_pkt(struct sk_buff *skb)
{
if (virtio_vsock_skb_tap_delivered(skb))
return;
vsock_deliver_tap(virtio_transport_build_skb, skb);
virtio_vsock_skb_set_tap_delivered(skb);
}
EXPORT_SYMBOL_GPL(virtio_transport_deliver_tap_pkt);
static u16 virtio_transport_get_type(struct sock *sk)
{
if (sk->sk_type == SOCK_STREAM)
return VIRTIO_VSOCK_TYPE_STREAM;
else
return VIRTIO_VSOCK_TYPE_SEQPACKET;
}
/* Returns new sk_buff on success, otherwise returns NULL. */
static struct sk_buff *virtio_transport_alloc_skb(struct virtio_vsock_pkt_info *info,
size_t payload_len,
bool zcopy,
u32 src_cid,
u32 src_port,
u32 dst_cid,
u32 dst_port)
{
struct vsock_sock *vsk;
struct sk_buff *skb;
size_t skb_len;
skb_len = VIRTIO_VSOCK_SKB_HEADROOM;
if (!zcopy)
skb_len += payload_len;
skb = virtio_vsock_alloc_skb(skb_len, GFP_KERNEL);
if (!skb)
return NULL;
virtio_transport_init_hdr(skb, info, payload_len, src_cid, src_port,
dst_cid, dst_port);
vsk = info->vsk;
/* If 'vsk' != NULL then payload is always present, so we
* will never call '__zerocopy_sg_from_iter()' below without
* setting skb owner in 'skb_set_owner_w()'. The only case
* when 'vsk' == NULL is VIRTIO_VSOCK_OP_RST control message
* without payload.
*/
WARN_ON_ONCE(!(vsk && (info->msg && payload_len)) && zcopy);
/* Set owner here, because '__zerocopy_sg_from_iter()' uses
* owner of skb without check to update 'sk_wmem_alloc'.
*/
if (vsk)
skb_set_owner_w(skb, sk_vsock(vsk));
if (info->msg && payload_len > 0) {
int err;
err = virtio_transport_fill_skb(skb, info, payload_len, zcopy);
if (err)
goto out;
if (msg_data_left(info->msg) == 0 &&
info->type == VIRTIO_VSOCK_TYPE_SEQPACKET) {
struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
hdr->flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOM);
if (info->msg->msg_flags & MSG_EOR)
hdr->flags |= cpu_to_le32(VIRTIO_VSOCK_SEQ_EOR);
}
}
if (info->reply)
virtio_vsock_skb_set_reply(skb);
trace_virtio_transport_alloc_pkt(src_cid, src_port,
dst_cid, dst_port,
payload_len,
info->type,
info->op,
info->flags,
zcopy);
return skb;
out:
kfree_skb(skb);
return NULL;
}
/* This function can only be used on connecting/connected sockets,
* since a socket assigned to a transport is required.
*
* Do not use on listener sockets!
*/
static int virtio_transport_send_pkt_info(struct vsock_sock *vsk,
struct virtio_vsock_pkt_info *info)
{
u32 max_skb_len = VIRTIO_VSOCK_MAX_PKT_BUF_SIZE;
u32 src_cid, src_port, dst_cid, dst_port;
const struct virtio_transport *t_ops;
struct virtio_vsock_sock *vvs;
u32 pkt_len = info->pkt_len;
bool can_zcopy = false;
u32 rest_len;
int ret;
info->type = virtio_transport_get_type(sk_vsock(vsk));
t_ops = virtio_transport_get_ops(vsk);
if (unlikely(!t_ops))
return -EFAULT;
src_cid = t_ops->transport.get_local_cid();
src_port = vsk->local_addr.svm_port;
if (!info->remote_cid) {
dst_cid = vsk->remote_addr.svm_cid;
dst_port = vsk->remote_addr.svm_port;
} else {
dst_cid = info->remote_cid;
dst_port = info->remote_port;
}
vvs = vsk->trans;
/* virtio_transport_get_credit might return less than pkt_len credit */
pkt_len = virtio_transport_get_credit(vvs, pkt_len);
/* Do not send zero length OP_RW pkt */
if (pkt_len == 0 && info->op == VIRTIO_VSOCK_OP_RW)
return pkt_len;
if (info->msg) {
/* If zerocopy is not enabled by 'setsockopt()', we behave as
* there is no MSG_ZEROCOPY flag set.
*/
if (!sock_flag(sk_vsock(vsk), SOCK_ZEROCOPY))
info->msg->msg_flags &= ~MSG_ZEROCOPY;
if (info->msg->msg_flags & MSG_ZEROCOPY)
can_zcopy = virtio_transport_can_zcopy(t_ops, info, pkt_len);
if (can_zcopy)
max_skb_len = min_t(u32, VIRTIO_VSOCK_MAX_PKT_BUF_SIZE,
(MAX_SKB_FRAGS * PAGE_SIZE));
}
rest_len = pkt_len;
do {
struct sk_buff *skb;
size_t skb_len;
skb_len = min(max_skb_len, rest_len);
skb = virtio_transport_alloc_skb(info, skb_len, can_zcopy,
src_cid, src_port,
dst_cid, dst_port);
if (!skb) {
ret = -ENOMEM;
break;
}
/* We process buffer part by part, allocating skb on
* each iteration. If this is last skb for this buffer
* and MSG_ZEROCOPY mode is in use - we must allocate
* completion for the current syscall.
*/
if (info->msg && info->msg->msg_flags & MSG_ZEROCOPY &&
skb_len == rest_len && info->op == VIRTIO_VSOCK_OP_RW) {
if (virtio_transport_init_zcopy_skb(vsk, skb,
info->msg,
can_zcopy)) {
ret = -ENOMEM;
break;
}
}
virtio_transport_inc_tx_pkt(vvs, skb);
ret = t_ops->send_pkt(skb);
if (ret < 0)
break;
/* Both virtio and vhost 'send_pkt()' returns 'skb_len',
* but for reliability use 'ret' instead of 'skb_len'.
* Also if partial send happens (e.g. 'ret' != 'skb_len')
* somehow, we break this loop, but account such returned
* value in 'virtio_transport_put_credit()'.
*/
rest_len -= ret;
if (WARN_ONCE(ret != skb_len,
"'send_pkt()' returns %i, but %zu expected\n",
ret, skb_len))
break;
} while (rest_len);
virtio_transport_put_credit(vvs, rest_len);
/* Return number of bytes, if any data has been sent. */
if (rest_len != pkt_len)
ret = pkt_len - rest_len;
return ret;
}
static bool virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs,
u32 len)
{
if (vvs->rx_bytes + len > vvs->buf_alloc)
return false;
vvs->rx_bytes += len;
return true;
}
static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs,
u32 len)
{
vvs->rx_bytes -= len;
vvs->fwd_cnt += len;
}
void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct sk_buff *skb)
{
struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
spin_lock_bh(&vvs->rx_lock);
vvs->last_fwd_cnt = vvs->fwd_cnt;
hdr->fwd_cnt = cpu_to_le32(vvs->fwd_cnt);
hdr->buf_alloc = cpu_to_le32(vvs->buf_alloc);
spin_unlock_bh(&vvs->rx_lock);
}
EXPORT_SYMBOL_GPL(virtio_transport_inc_tx_pkt);
void virtio_transport_consume_skb_sent(struct sk_buff *skb, bool consume)
{
struct sock *s = skb->sk;
if (s && skb->len) {
struct vsock_sock *vs = vsock_sk(s);
struct virtio_vsock_sock *vvs;
vvs = vs->trans;
spin_lock_bh(&vvs->tx_lock);
vvs->bytes_unsent -= skb->len;
spin_unlock_bh(&vvs->tx_lock);
}
if (consume)
consume_skb(skb);
}
EXPORT_SYMBOL_GPL(virtio_transport_consume_skb_sent);
u32 virtio_transport_get_credit(struct virtio_vsock_sock *vvs, u32 credit)
{
u32 ret;
if (!credit)
return 0;
spin_lock_bh(&vvs->tx_lock);
ret = vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt);
if (ret > credit)
ret = credit;
vvs->tx_cnt += ret;
vvs->bytes_unsent += ret;
spin_unlock_bh(&vvs->tx_lock);
return ret;
}
EXPORT_SYMBOL_GPL(virtio_transport_get_credit);
void virtio_transport_put_credit(struct virtio_vsock_sock *vvs, u32 credit)
{
if (!credit)
return;
spin_lock_bh(&vvs->tx_lock);
vvs->tx_cnt -= credit;
vvs->bytes_unsent -= credit;
spin_unlock_bh(&vvs->tx_lock);
}
EXPORT_SYMBOL_GPL(virtio_transport_put_credit);
static int virtio_transport_send_credit_update(struct vsock_sock *vsk)
{
struct virtio_vsock_pkt_info info = {
.op = VIRTIO_VSOCK_OP_CREDIT_UPDATE,
.vsk = vsk,
};
return virtio_transport_send_pkt_info(vsk, &info);
}
static ssize_t
virtio_transport_stream_do_peek(struct vsock_sock *vsk,
struct msghdr *msg,
size_t len)
{
struct virtio_vsock_sock *vvs = vsk->trans;
struct sk_buff *skb;
size_t total = 0;
int err;
spin_lock_bh(&vvs->rx_lock);
skb_queue_walk(&vvs->rx_queue, skb) {
size_t bytes;
bytes = len - total;
if (bytes > skb->len)
bytes = skb->len;
spin_unlock_bh(&vvs->rx_lock);
/* sk_lock is held by caller so no one else can dequeue.
* Unlock rx_lock since skb_copy_datagram_iter() may sleep.
*/
err = skb_copy_datagram_iter(skb, VIRTIO_VSOCK_SKB_CB(skb)->offset,
&msg->msg_iter, bytes);
if (err)
goto out;
total += bytes;
spin_lock_bh(&vvs->rx_lock);
if (total == len)
break;
}
spin_unlock_bh(&vvs->rx_lock);
return total;
out:
if (total)
err = total;
return err;
}
static ssize_t
virtio_transport_stream_do_dequeue(struct vsock_sock *vsk,
struct msghdr *msg,
size_t len)
{
struct virtio_vsock_sock *vvs = vsk->trans;
size_t bytes, total = 0;
struct sk_buff *skb;
u32 fwd_cnt_delta;
bool low_rx_bytes;
int err = -EFAULT;
u32 free_space;
spin_lock_bh(&vvs->rx_lock);
if (WARN_ONCE(skb_queue_empty(&vvs->rx_queue) && vvs->rx_bytes,
"rx_queue is empty, but rx_bytes is non-zero\n")) {
spin_unlock_bh(&vvs->rx_lock);
return err;
}
while (total < len && !skb_queue_empty(&vvs->rx_queue)) {
skb = skb_peek(&vvs->rx_queue);
bytes = min_t(size_t, len - total,
skb->len - VIRTIO_VSOCK_SKB_CB(skb)->offset);
/* sk_lock is held by caller so no one else can dequeue.
* Unlock rx_lock since skb_copy_datagram_iter() may sleep.
*/
spin_unlock_bh(&vvs->rx_lock);
err = skb_copy_datagram_iter(skb,
VIRTIO_VSOCK_SKB_CB(skb)->offset,
&msg->msg_iter, bytes);
if (err)
goto out;
spin_lock_bh(&vvs->rx_lock);
total += bytes;
VIRTIO_VSOCK_SKB_CB(skb)->offset += bytes;
if (skb->len == VIRTIO_VSOCK_SKB_CB(skb)->offset) {
u32 pkt_len = le32_to_cpu(virtio_vsock_hdr(skb)->len);
virtio_transport_dec_rx_pkt(vvs, pkt_len);
__skb_unlink(skb, &vvs->rx_queue);
consume_skb(skb);
}
}
fwd_cnt_delta = vvs->fwd_cnt - vvs->last_fwd_cnt;
free_space = vvs->buf_alloc - fwd_cnt_delta;
low_rx_bytes = (vvs->rx_bytes <
sock_rcvlowat(sk_vsock(vsk), 0, INT_MAX));
spin_unlock_bh(&vvs->rx_lock);
/* To reduce the number of credit update messages,
* don't update credits as long as lots of space is available.
* Note: the limit chosen here is arbitrary. Setting the limit
* too high causes extra messages. Too low causes transmitter
* stalls. As stalls are in theory more expensive than extra
* messages, we set the limit to a high value. TODO: experiment
* with different values. Also send credit update message when
* number of bytes in rx queue is not enough to wake up reader.
*/
if (fwd_cnt_delta &&
(free_space < VIRTIO_VSOCK_MAX_PKT_BUF_SIZE || low_rx_bytes))
virtio_transport_send_credit_update(vsk);
return total;
out:
if (total)
err = total;
return err;
}
static ssize_t
virtio_transport_seqpacket_do_peek(struct vsock_sock *vsk,
struct msghdr *msg)
{
struct virtio_vsock_sock *vvs = vsk->trans;
struct sk_buff *skb;
size_t total, len;
spin_lock_bh(&vvs->rx_lock);
if (!vvs->msg_count) {
spin_unlock_bh(&vvs->rx_lock);
return 0;
}
total = 0;
len = msg_data_left(msg);
skb_queue_walk(&vvs->rx_queue, skb) {
struct virtio_vsock_hdr *hdr;
if (total < len) {
size_t bytes;
int err;
bytes = len - total;
if (bytes > skb->len)
bytes = skb->len;
spin_unlock_bh(&vvs->rx_lock);
/* sk_lock is held by caller so no one else can dequeue.
* Unlock rx_lock since skb_copy_datagram_iter() may sleep.
*/
err = skb_copy_datagram_iter(skb, VIRTIO_VSOCK_SKB_CB(skb)->offset,
&msg->msg_iter, bytes);
if (err)
return err;
spin_lock_bh(&vvs->rx_lock);
}
total += skb->len;
hdr = virtio_vsock_hdr(skb);
if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM) {
if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOR)
msg->msg_flags |= MSG_EOR;
break;
}
}
spin_unlock_bh(&vvs->rx_lock);
return total;
}
static int virtio_transport_seqpacket_do_dequeue(struct vsock_sock *vsk,
struct msghdr *msg,
int flags)
{
struct virtio_vsock_sock *vvs = vsk->trans;
int dequeued_len = 0;
size_t user_buf_len = msg_data_left(msg);
bool msg_ready = false;
struct sk_buff *skb;
spin_lock_bh(&vvs->rx_lock);
if (vvs->msg_count == 0) {
spin_unlock_bh(&vvs->rx_lock);
return 0;
}
while (!msg_ready) {
struct virtio_vsock_hdr *hdr;
size_t pkt_len;
skb = __skb_dequeue(&vvs->rx_queue);
if (!skb)
break;
hdr = virtio_vsock_hdr(skb);
pkt_len = (size_t)le32_to_cpu(hdr->len);
if (dequeued_len >= 0) {
size_t bytes_to_copy;
bytes_to_copy = min(user_buf_len, pkt_len);
if (bytes_to_copy) {
int err;
/* sk_lock is held by caller so no one else can dequeue.
* Unlock rx_lock since skb_copy_datagram_iter() may sleep.
*/
spin_unlock_bh(&vvs->rx_lock);
err = skb_copy_datagram_iter(skb, 0,
&msg->msg_iter,
bytes_to_copy);
if (err) {
/* Copy of message failed. Rest of
* fragments will be freed without copy.
*/
dequeued_len = err;
} else {
user_buf_len -= bytes_to_copy;
}
spin_lock_bh(&vvs->rx_lock);
}
if (dequeued_len >= 0)
dequeued_len += pkt_len;
}
if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM) {
msg_ready = true;
vvs->msg_count--;
if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOR)
msg->msg_flags |= MSG_EOR;
}
virtio_transport_dec_rx_pkt(vvs, pkt_len);
kfree_skb(skb);
}
spin_unlock_bh(&vvs->rx_lock);
virtio_transport_send_credit_update(vsk);
return dequeued_len;
}
ssize_t
virtio_transport_stream_dequeue(struct vsock_sock *vsk,
struct msghdr *msg,
size_t len, int flags)
{
if (flags & MSG_PEEK)
return virtio_transport_stream_do_peek(vsk, msg, len);
else
return virtio_transport_stream_do_dequeue(vsk, msg, len);
}
EXPORT_SYMBOL_GPL(virtio_transport_stream_dequeue);
ssize_t
virtio_transport_seqpacket_dequeue(struct vsock_sock *vsk,
struct msghdr *msg,
int flags)
{
if (flags & MSG_PEEK)
return virtio_transport_seqpacket_do_peek(vsk, msg);
else
return virtio_transport_seqpacket_do_dequeue(vsk, msg, flags);
}
EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_dequeue);
int
virtio_transport_seqpacket_enqueue(struct vsock_sock *vsk,
struct msghdr *msg,
size_t len)
{
struct virtio_vsock_sock *vvs = vsk->trans;
spin_lock_bh(&vvs->tx_lock);
if (len > vvs->peer_buf_alloc) {
spin_unlock_bh(&vvs->tx_lock);
return -EMSGSIZE;
}
spin_unlock_bh(&vvs->tx_lock);
return virtio_transport_stream_enqueue(vsk, msg, len);
}
EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_enqueue);
int
virtio_transport_dgram_dequeue(struct vsock_sock *vsk,
struct msghdr *msg,
size_t len, int flags)
{
return -EOPNOTSUPP;
}
EXPORT_SYMBOL_GPL(virtio_transport_dgram_dequeue);
s64 virtio_transport_stream_has_data(struct vsock_sock *vsk)
{
struct virtio_vsock_sock *vvs = vsk->trans;
s64 bytes;
spin_lock_bh(&vvs->rx_lock);
bytes = vvs->rx_bytes;
spin_unlock_bh(&vvs->rx_lock);
return bytes;
}
EXPORT_SYMBOL_GPL(virtio_transport_stream_has_data);
u32 virtio_transport_seqpacket_has_data(struct vsock_sock *vsk)
{
struct virtio_vsock_sock *vvs = vsk->trans;
u32 msg_count;
spin_lock_bh(&vvs->rx_lock);
msg_count = vvs->msg_count;
spin_unlock_bh(&vvs->rx_lock);
return msg_count;
}
EXPORT_SYMBOL_GPL(virtio_transport_seqpacket_has_data);
static s64 virtio_transport_has_space(struct vsock_sock *vsk)
{
struct virtio_vsock_sock *vvs = vsk->trans;
s64 bytes;
bytes = (s64)vvs->peer_buf_alloc - (vvs->tx_cnt - vvs->peer_fwd_cnt);
if (bytes < 0)
bytes = 0;
return bytes;
}
s64 virtio_transport_stream_has_space(struct vsock_sock *vsk)
{
struct virtio_vsock_sock *vvs = vsk->trans;
s64 bytes;
spin_lock_bh(&vvs->tx_lock);
bytes = virtio_transport_has_space(vsk);
spin_unlock_bh(&vvs->tx_lock);
return bytes;
}
EXPORT_SYMBOL_GPL(virtio_transport_stream_has_space);
int virtio_transport_do_socket_init(struct vsock_sock *vsk,
struct vsock_sock *psk)
{
struct virtio_vsock_sock *vvs;
vvs = kzalloc(sizeof(*vvs), GFP_KERNEL);
if (!vvs)
return -ENOMEM;
vsk->trans = vvs;
vvs->vsk = vsk;
if (psk && psk->trans) {
struct virtio_vsock_sock *ptrans = psk->trans;
vvs->peer_buf_alloc = ptrans->peer_buf_alloc;
}
if (vsk->buffer_size > VIRTIO_VSOCK_MAX_BUF_SIZE)
vsk->buffer_size = VIRTIO_VSOCK_MAX_BUF_SIZE;
vvs->buf_alloc = vsk->buffer_size;
spin_lock_init(&vvs->rx_lock);
spin_lock_init(&vvs->tx_lock);
skb_queue_head_init(&vvs->rx_queue);
return 0;
}
EXPORT_SYMBOL_GPL(virtio_transport_do_socket_init);
/* sk_lock held by the caller */
void virtio_transport_notify_buffer_size(struct vsock_sock *vsk, u64 *val)
{
struct virtio_vsock_sock *vvs = vsk->trans;
if (*val > VIRTIO_VSOCK_MAX_BUF_SIZE)
*val = VIRTIO_VSOCK_MAX_BUF_SIZE;
vvs->buf_alloc = *val;
virtio_transport_send_credit_update(vsk);
}
EXPORT_SYMBOL_GPL(virtio_transport_notify_buffer_size);
int
virtio_transport_notify_poll_in(struct vsock_sock *vsk,
size_t target,
bool *data_ready_now)
{
*data_ready_now = vsock_stream_has_data(vsk) >= target;
return 0;
}
EXPORT_SYMBOL_GPL(virtio_transport_notify_poll_in);
int
virtio_transport_notify_poll_out(struct vsock_sock *vsk,
size_t target,
bool *space_avail_now)
{
s64 free_space;
free_space = vsock_stream_has_space(vsk);
if (free_space > 0)
*space_avail_now = true;
else if (free_space == 0)
*space_avail_now = false;
return 0;
}
EXPORT_SYMBOL_GPL(virtio_transport_notify_poll_out);
int virtio_transport_notify_recv_init(struct vsock_sock *vsk,
size_t target, struct vsock_transport_recv_notify_data *data)
{
return 0;
}
EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_init);
int virtio_transport_notify_recv_pre_block(struct vsock_sock *vsk,
size_t target, struct vsock_transport_recv_notify_data *data)
{
return 0;
}
EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_pre_block);
int virtio_transport_notify_recv_pre_dequeue(struct vsock_sock *vsk,
size_t target, struct vsock_transport_recv_notify_data *data)
{
return 0;
}
EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_pre_dequeue);
int virtio_transport_notify_recv_post_dequeue(struct vsock_sock *vsk,
size_t target, ssize_t copied, bool data_read,
struct vsock_transport_recv_notify_data *data)
{
return 0;
}
EXPORT_SYMBOL_GPL(virtio_transport_notify_recv_post_dequeue);
int virtio_transport_notify_send_init(struct vsock_sock *vsk,
struct vsock_transport_send_notify_data *data)
{
return 0;
}
EXPORT_SYMBOL_GPL(virtio_transport_notify_send_init);
int virtio_transport_notify_send_pre_block(struct vsock_sock *vsk,
struct vsock_transport_send_notify_data *data)
{
return 0;
}
EXPORT_SYMBOL_GPL(virtio_transport_notify_send_pre_block);
int virtio_transport_notify_send_pre_enqueue(struct vsock_sock *vsk,
struct vsock_transport_send_notify_data *data)
{
return 0;
}
EXPORT_SYMBOL_GPL(virtio_transport_notify_send_pre_enqueue);
int virtio_transport_notify_send_post_enqueue(struct vsock_sock *vsk,
ssize_t written, struct vsock_transport_send_notify_data *data)
{
return 0;
}
EXPORT_SYMBOL_GPL(virtio_transport_notify_send_post_enqueue);
u64 virtio_transport_stream_rcvhiwat(struct vsock_sock *vsk)
{
return vsk->buffer_size;
}
EXPORT_SYMBOL_GPL(virtio_transport_stream_rcvhiwat);
bool virtio_transport_stream_is_active(struct vsock_sock *vsk)
{
return true;
}
EXPORT_SYMBOL_GPL(virtio_transport_stream_is_active);
bool virtio_transport_stream_allow(u32 cid, u32 port)
{
return true;
}
EXPORT_SYMBOL_GPL(virtio_transport_stream_allow);
int virtio_transport_dgram_bind(struct vsock_sock *vsk,
struct sockaddr_vm *addr)
{
return -EOPNOTSUPP;
}
EXPORT_SYMBOL_GPL(virtio_transport_dgram_bind);
bool virtio_transport_dgram_allow(u32 cid, u32 port)
{
return false;
}
EXPORT_SYMBOL_GPL(virtio_transport_dgram_allow);
int virtio_transport_connect(struct vsock_sock *vsk)
{
struct virtio_vsock_pkt_info info = {
.op = VIRTIO_VSOCK_OP_REQUEST,
.vsk = vsk,
};
return virtio_transport_send_pkt_info(vsk, &info);
}
EXPORT_SYMBOL_GPL(virtio_transport_connect);
int virtio_transport_shutdown(struct vsock_sock *vsk, int mode)
{
struct virtio_vsock_pkt_info info = {
.op = VIRTIO_VSOCK_OP_SHUTDOWN,
.flags = (mode & RCV_SHUTDOWN ?
VIRTIO_VSOCK_SHUTDOWN_RCV : 0) |
(mode & SEND_SHUTDOWN ?
VIRTIO_VSOCK_SHUTDOWN_SEND : 0),
.vsk = vsk,
};
return virtio_transport_send_pkt_info(vsk, &info);
}
EXPORT_SYMBOL_GPL(virtio_transport_shutdown);
int
virtio_transport_dgram_enqueue(struct vsock_sock *vsk,
struct sockaddr_vm *remote_addr,
struct msghdr *msg,
size_t dgram_len)
{
return -EOPNOTSUPP;
}
EXPORT_SYMBOL_GPL(virtio_transport_dgram_enqueue);
ssize_t
virtio_transport_stream_enqueue(struct vsock_sock *vsk,
struct msghdr *msg,
size_t len)
{
struct virtio_vsock_pkt_info info = {
.op = VIRTIO_VSOCK_OP_RW,
.msg = msg,
.pkt_len = len,
.vsk = vsk,
};
return virtio_transport_send_pkt_info(vsk, &info);
}
EXPORT_SYMBOL_GPL(virtio_transport_stream_enqueue);
void virtio_transport_destruct(struct vsock_sock *vsk)
{
struct virtio_vsock_sock *vvs = vsk->trans;
kfree(vvs);
}
EXPORT_SYMBOL_GPL(virtio_transport_destruct);
ssize_t virtio_transport_unsent_bytes(struct vsock_sock *vsk)
{
struct virtio_vsock_sock *vvs = vsk->trans;
size_t ret;
spin_lock_bh(&vvs->tx_lock);
ret = vvs->bytes_unsent;
spin_unlock_bh(&vvs->tx_lock);
return ret;
}
EXPORT_SYMBOL_GPL(virtio_transport_unsent_bytes);
static int virtio_transport_reset(struct vsock_sock *vsk,
struct sk_buff *skb)
{
struct virtio_vsock_pkt_info info = {
.op = VIRTIO_VSOCK_OP_RST,
.reply = !!skb,
.vsk = vsk,
};
/* Send RST only if the original pkt is not a RST pkt */
if (skb && le16_to_cpu(virtio_vsock_hdr(skb)->op) == VIRTIO_VSOCK_OP_RST)
return 0;
return virtio_transport_send_pkt_info(vsk, &info);
}
/* Normally packets are associated with a socket. There may be no socket if an
* attempt was made to connect to a socket that does not exist.
*/
static int virtio_transport_reset_no_sock(const struct virtio_transport *t,
struct sk_buff *skb)
{
struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
struct virtio_vsock_pkt_info info = {
.op = VIRTIO_VSOCK_OP_RST,
.type = le16_to_cpu(hdr->type),
.reply = true,
};
struct sk_buff *reply;
/* Send RST only if the original pkt is not a RST pkt */
if (le16_to_cpu(hdr->op) == VIRTIO_VSOCK_OP_RST)
return 0;
if (!t)
return -ENOTCONN;
reply = virtio_transport_alloc_skb(&info, 0, false,
le64_to_cpu(hdr->dst_cid),
le32_to_cpu(hdr->dst_port),
le64_to_cpu(hdr->src_cid),
le32_to_cpu(hdr->src_port));
if (!reply)
return -ENOMEM;
return t->send_pkt(reply);
}
/* This function should be called with sk_lock held and SOCK_DONE set */
static void virtio_transport_remove_sock(struct vsock_sock *vsk)
{
struct virtio_vsock_sock *vvs = vsk->trans;
/* We don't need to take rx_lock, as the socket is closing and we are
* removing it.
*/
__skb_queue_purge(&vvs->rx_queue);
vsock_remove_sock(vsk);
}
static void virtio_transport_wait_close(struct sock *sk, long timeout)
{
if (timeout) {
DEFINE_WAIT_FUNC(wait, woken_wake_function);
add_wait_queue(sk_sleep(sk), &wait);
do {
if (sk_wait_event(sk, &timeout,
sock_flag(sk, SOCK_DONE), &wait))
break;
} while (!signal_pending(current) && timeout);
remove_wait_queue(sk_sleep(sk), &wait);
}
}
static void virtio_transport_do_close(struct vsock_sock *vsk,
bool cancel_timeout)
{
struct sock *sk = sk_vsock(vsk);
sock_set_flag(sk, SOCK_DONE);
vsk->peer_shutdown = SHUTDOWN_MASK;
if (vsock_stream_has_data(vsk) <= 0)
sk->sk_state = TCP_CLOSING;
sk->sk_state_change(sk);
if (vsk->close_work_scheduled &&
(!cancel_timeout || cancel_delayed_work(&vsk->close_work))) {
vsk->close_work_scheduled = false;
virtio_transport_remove_sock(vsk);
/* Release refcnt obtained when we scheduled the timeout */
sock_put(sk);
}
}
static void virtio_transport_close_timeout(struct work_struct *work)
{
struct vsock_sock *vsk =
container_of(work, struct vsock_sock, close_work.work);
struct sock *sk = sk_vsock(vsk);
sock_hold(sk);
lock_sock(sk);
if (!sock_flag(sk, SOCK_DONE)) {
(void)virtio_transport_reset(vsk, NULL);
virtio_transport_do_close(vsk, false);
}
vsk->close_work_scheduled = false;
release_sock(sk);
sock_put(sk);
}
/* User context, vsk->sk is locked */
static bool virtio_transport_close(struct vsock_sock *vsk)
{
struct sock *sk = &vsk->sk;
if (!(sk->sk_state == TCP_ESTABLISHED ||
sk->sk_state == TCP_CLOSING))
return true;
/* Already received SHUTDOWN from peer, reply with RST */
if ((vsk->peer_shutdown & SHUTDOWN_MASK) == SHUTDOWN_MASK) {
(void)virtio_transport_reset(vsk, NULL);
return true;
}
if ((sk->sk_shutdown & SHUTDOWN_MASK) != SHUTDOWN_MASK)
(void)virtio_transport_shutdown(vsk, SHUTDOWN_MASK);
if (sock_flag(sk, SOCK_LINGER) && !(current->flags & PF_EXITING))
virtio_transport_wait_close(sk, sk->sk_lingertime);
if (sock_flag(sk, SOCK_DONE)) {
return true;
}
sock_hold(sk);
INIT_DELAYED_WORK(&vsk->close_work,
virtio_transport_close_timeout);
vsk->close_work_scheduled = true;
schedule_delayed_work(&vsk->close_work, VSOCK_CLOSE_TIMEOUT);
return false;
}
void virtio_transport_release(struct vsock_sock *vsk)
{
struct sock *sk = &vsk->sk;
bool remove_sock = true;
if (sk->sk_type == SOCK_STREAM || sk->sk_type == SOCK_SEQPACKET)
remove_sock = virtio_transport_close(vsk);
if (remove_sock) {
sock_set_flag(sk, SOCK_DONE);
virtio_transport_remove_sock(vsk);
}
}
EXPORT_SYMBOL_GPL(virtio_transport_release);
static int
virtio_transport_recv_connecting(struct sock *sk,
struct sk_buff *skb)
{
struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
struct vsock_sock *vsk = vsock_sk(sk);
int skerr;
int err;
switch (le16_to_cpu(hdr->op)) {
case VIRTIO_VSOCK_OP_RESPONSE:
sk->sk_state = TCP_ESTABLISHED;
sk->sk_socket->state = SS_CONNECTED;
vsock_insert_connected(vsk);
sk->sk_state_change(sk);
break;
case VIRTIO_VSOCK_OP_INVALID:
break;
case VIRTIO_VSOCK_OP_RST:
skerr = ECONNRESET;
err = 0;
goto destroy;
default:
skerr = EPROTO;
err = -EINVAL;
goto destroy;
}
return 0;
destroy:
virtio_transport_reset(vsk, skb);
sk->sk_state = TCP_CLOSE;
sk->sk_err = skerr;
sk_error_report(sk);
return err;
}
static void
virtio_transport_recv_enqueue(struct vsock_sock *vsk,
struct sk_buff *skb)
{
struct virtio_vsock_sock *vvs = vsk->trans;
bool can_enqueue, free_pkt = false;
struct virtio_vsock_hdr *hdr;
u32 len;
hdr = virtio_vsock_hdr(skb);
len = le32_to_cpu(hdr->len);
spin_lock_bh(&vvs->rx_lock);
can_enqueue = virtio_transport_inc_rx_pkt(vvs, len);
if (!can_enqueue) {
free_pkt = true;
goto out;
}
if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SEQ_EOM)
vvs->msg_count++;
/* Try to copy small packets into the buffer of last packet queued,
* to avoid wasting memory queueing the entire buffer with a small
* payload.
*/
if (len <= GOOD_COPY_LEN && !skb_queue_empty(&vvs->rx_queue)) {
struct virtio_vsock_hdr *last_hdr;
struct sk_buff *last_skb;
last_skb = skb_peek_tail(&vvs->rx_queue);
last_hdr = virtio_vsock_hdr(last_skb);
/* If there is space in the last packet queued, we copy the
* new packet in its buffer. We avoid this if the last packet
* queued has VIRTIO_VSOCK_SEQ_EOM set, because this is
* delimiter of SEQPACKET message, so 'pkt' is the first packet
* of a new message.
*/
if (skb->len < skb_tailroom(last_skb) &&
!(le32_to_cpu(last_hdr->flags) & VIRTIO_VSOCK_SEQ_EOM)) {
memcpy(skb_put(last_skb, skb->len), skb->data, skb->len);
free_pkt = true;
last_hdr->flags |= hdr->flags;
le32_add_cpu(&last_hdr->len, len);
goto out;
}
}
__skb_queue_tail(&vvs->rx_queue, skb);
out:
spin_unlock_bh(&vvs->rx_lock);
if (free_pkt)
kfree_skb(skb);
}
static int
virtio_transport_recv_connected(struct sock *sk,
struct sk_buff *skb)
{
struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
struct vsock_sock *vsk = vsock_sk(sk);
int err = 0;
switch (le16_to_cpu(hdr->op)) {
case VIRTIO_VSOCK_OP_RW:
virtio_transport_recv_enqueue(vsk, skb);
vsock_data_ready(sk);
return err;
case VIRTIO_VSOCK_OP_CREDIT_REQUEST:
virtio_transport_send_credit_update(vsk);
break;
case VIRTIO_VSOCK_OP_CREDIT_UPDATE:
sk->sk_write_space(sk);
break;
case VIRTIO_VSOCK_OP_SHUTDOWN:
if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SHUTDOWN_RCV)
vsk->peer_shutdown |= RCV_SHUTDOWN;
if (le32_to_cpu(hdr->flags) & VIRTIO_VSOCK_SHUTDOWN_SEND)
vsk->peer_shutdown |= SEND_SHUTDOWN;
if (vsk->peer_shutdown == SHUTDOWN_MASK) {
if (vsock_stream_has_data(vsk) <= 0 && !sock_flag(sk, SOCK_DONE)) {
(void)virtio_transport_reset(vsk, NULL);
virtio_transport_do_close(vsk, true);
}
/* Remove this socket anyway because the remote peer sent
* the shutdown. This way a new connection will succeed
* if the remote peer uses the same source port,
* even if the old socket is still unreleased, but now disconnected.
*/
vsock_remove_sock(vsk);
}
if (le32_to_cpu(virtio_vsock_hdr(skb)->flags))
sk->sk_state_change(sk);
break;
case VIRTIO_VSOCK_OP_RST:
virtio_transport_do_close(vsk, true);
break;
default:
err = -EINVAL;
break;
}
kfree_skb(skb);
return err;
}
static void
virtio_transport_recv_disconnecting(struct sock *sk,
struct sk_buff *skb)
{
struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
struct vsock_sock *vsk = vsock_sk(sk);
if (le16_to_cpu(hdr->op) == VIRTIO_VSOCK_OP_RST)
virtio_transport_do_close(vsk, true);
}
static int
virtio_transport_send_response(struct vsock_sock *vsk,
struct sk_buff *skb)
{
struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
struct virtio_vsock_pkt_info info = {
.op = VIRTIO_VSOCK_OP_RESPONSE,
.remote_cid = le64_to_cpu(hdr->src_cid),
.remote_port = le32_to_cpu(hdr->src_port),
.reply = true,
.vsk = vsk,
};
return virtio_transport_send_pkt_info(vsk, &info);
}
static bool virtio_transport_space_update(struct sock *sk,
struct sk_buff *skb)
{
struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
struct vsock_sock *vsk = vsock_sk(sk);
struct virtio_vsock_sock *vvs = vsk->trans;
bool space_available;
/* Listener sockets are not associated with any transport, so we are
* not able to take the state to see if there is space available in the
* remote peer, but since they are only used to receive requests, we
* can assume that there is always space available in the other peer.
*/
if (!vvs)
return true;
/* buf_alloc and fwd_cnt is always included in the hdr */
spin_lock_bh(&vvs->tx_lock);
vvs->peer_buf_alloc = le32_to_cpu(hdr->buf_alloc);
vvs->peer_fwd_cnt = le32_to_cpu(hdr->fwd_cnt);
space_available = virtio_transport_has_space(vsk);
spin_unlock_bh(&vvs->tx_lock);
return space_available;
}
/* Handle server socket */
static int
virtio_transport_recv_listen(struct sock *sk, struct sk_buff *skb,
struct virtio_transport *t)
{
struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
struct vsock_sock *vsk = vsock_sk(sk);
struct vsock_sock *vchild;
struct sock *child;
int ret;
if (le16_to_cpu(hdr->op) != VIRTIO_VSOCK_OP_REQUEST) {
virtio_transport_reset_no_sock(t, skb);
return -EINVAL;
}
if (sk_acceptq_is_full(sk)) {
virtio_transport_reset_no_sock(t, skb);
return -ENOMEM;
}
child = vsock_create_connected(sk);
if (!child) {
virtio_transport_reset_no_sock(t, skb);
return -ENOMEM;
}
sk_acceptq_added(sk);
lock_sock_nested(child, SINGLE_DEPTH_NESTING);
child->sk_state = TCP_ESTABLISHED;
vchild = vsock_sk(child);
vsock_addr_init(&vchild->local_addr, le64_to_cpu(hdr->dst_cid),
le32_to_cpu(hdr->dst_port));
vsock_addr_init(&vchild->remote_addr, le64_to_cpu(hdr->src_cid),
le32_to_cpu(hdr->src_port));
ret = vsock_assign_transport(vchild, vsk);
/* Transport assigned (looking at remote_addr) must be the same
* where we received the request.
*/
if (ret || vchild->transport != &t->transport) {
release_sock(child);
virtio_transport_reset_no_sock(t, skb);
sock_put(child);
return ret;
}
if (virtio_transport_space_update(child, skb))
child->sk_write_space(child);
vsock_insert_connected(vchild);
vsock_enqueue_accept(sk, child);
virtio_transport_send_response(vchild, skb);
release_sock(child);
sk->sk_data_ready(sk);
return 0;
}
static bool virtio_transport_valid_type(u16 type)
{
return (type == VIRTIO_VSOCK_TYPE_STREAM) ||
(type == VIRTIO_VSOCK_TYPE_SEQPACKET);
}
/* We are under the virtio-vsock's vsock->rx_lock or vhost-vsock's vq->mutex
* lock.
*/
void virtio_transport_recv_pkt(struct virtio_transport *t,
struct sk_buff *skb)
{
struct virtio_vsock_hdr *hdr = virtio_vsock_hdr(skb);
struct sockaddr_vm src, dst;
struct vsock_sock *vsk;
struct sock *sk;
bool space_available;
vsock_addr_init(&src, le64_to_cpu(hdr->src_cid),
le32_to_cpu(hdr->src_port));
vsock_addr_init(&dst, le64_to_cpu(hdr->dst_cid),
le32_to_cpu(hdr->dst_port));
trace_virtio_transport_recv_pkt(src.svm_cid, src.svm_port,
dst.svm_cid, dst.svm_port,
le32_to_cpu(hdr->len),
le16_to_cpu(hdr->type),
le16_to_cpu(hdr->op),
le32_to_cpu(hdr->flags),
le32_to_cpu(hdr->buf_alloc),
le32_to_cpu(hdr->fwd_cnt));
if (!virtio_transport_valid_type(le16_to_cpu(hdr->type))) {
(void)virtio_transport_reset_no_sock(t, skb);
goto free_pkt;
}
/* The socket must be in connected or bound table
* otherwise send reset back
*/
sk = vsock_find_connected_socket(&src, &dst);
if (!sk) {
sk = vsock_find_bound_socket(&dst);
if (!sk) {
(void)virtio_transport_reset_no_sock(t, skb);
goto free_pkt;
}
}
if (virtio_transport_get_type(sk) != le16_to_cpu(hdr->type)) {
(void)virtio_transport_reset_no_sock(t, skb);
sock_put(sk);
goto free_pkt;
}
if (!skb_set_owner_sk_safe(skb, sk)) {
WARN_ONCE(1, "receiving vsock socket has sk_refcnt == 0\n");
goto free_pkt;
}
vsk = vsock_sk(sk);
lock_sock(sk);
/* Check if sk has been closed before lock_sock */
if (sock_flag(sk, SOCK_DONE)) {
(void)virtio_transport_reset_no_sock(t, skb);
release_sock(sk);
sock_put(sk);
goto free_pkt;
}
space_available = virtio_transport_space_update(sk, skb);
/* Update CID in case it has changed after a transport reset event */
if (vsk->local_addr.svm_cid != VMADDR_CID_ANY)
vsk->local_addr.svm_cid = dst.svm_cid;
if (space_available)
sk->sk_write_space(sk);
switch (sk->sk_state) {
case TCP_LISTEN:
virtio_transport_recv_listen(sk, skb, t);
kfree_skb(skb);
break;
case TCP_SYN_SENT:
virtio_transport_recv_connecting(sk, skb);
kfree_skb(skb);
break;
case TCP_ESTABLISHED:
virtio_transport_recv_connected(sk, skb);
break;
case TCP_CLOSING:
virtio_transport_recv_disconnecting(sk, skb);
kfree_skb(skb);
break;
default:
(void)virtio_transport_reset_no_sock(t, skb);
kfree_skb(skb);
break;
}
release_sock(sk);
/* Release refcnt obtained when we fetched this socket out of the
* bound or connected list.
*/
sock_put(sk);
return;
free_pkt:
kfree_skb(skb);
}
EXPORT_SYMBOL_GPL(virtio_transport_recv_pkt);
/* Remove skbs found in a queue that have a vsk that matches.
*
* Each skb is freed.
*
* Returns the count of skbs that were reply packets.
*/
int virtio_transport_purge_skbs(void *vsk, struct sk_buff_head *queue)
{
struct sk_buff_head freeme;
struct sk_buff *skb, *tmp;
int cnt = 0;
skb_queue_head_init(&freeme);
spin_lock_bh(&queue->lock);
skb_queue_walk_safe(queue, skb, tmp) {
if (vsock_sk(skb->sk) != vsk)
continue;
__skb_unlink(skb, queue);
__skb_queue_tail(&freeme, skb);
if (virtio_vsock_skb_reply(skb))
cnt++;
}
spin_unlock_bh(&queue->lock);
__skb_queue_purge(&freeme);
return cnt;
}
EXPORT_SYMBOL_GPL(virtio_transport_purge_skbs);
int virtio_transport_read_skb(struct vsock_sock *vsk, skb_read_actor_t recv_actor)
{
struct virtio_vsock_sock *vvs = vsk->trans;
struct sock *sk = sk_vsock(vsk);
struct sk_buff *skb;
int off = 0;
int err;
spin_lock_bh(&vvs->rx_lock);
/* Use __skb_recv_datagram() for race-free handling of the receive. It
* works for types other than dgrams.
*/
skb = __skb_recv_datagram(sk, &vvs->rx_queue, MSG_DONTWAIT, &off, &err);
spin_unlock_bh(&vvs->rx_lock);
if (!skb)
return err;
return recv_actor(sk, skb);
}
EXPORT_SYMBOL_GPL(virtio_transport_read_skb);
int virtio_transport_notify_set_rcvlowat(struct vsock_sock *vsk, int val)
{
struct virtio_vsock_sock *vvs = vsk->trans;
bool send_update;
spin_lock_bh(&vvs->rx_lock);
/* If number of available bytes is less than new SO_RCVLOWAT value,
* kick sender to send more data, because sender may sleep in its
* 'send()' syscall waiting for enough space at our side. Also
* don't send credit update when peer already knows actual value -
* such transmission will be useless.
*/
send_update = (vvs->rx_bytes < val) &&
(vvs->fwd_cnt != vvs->last_fwd_cnt);
spin_unlock_bh(&vvs->rx_lock);
if (send_update) {
int err;
err = virtio_transport_send_credit_update(vsk);
if (err < 0)
return err;
}
return 0;
}
EXPORT_SYMBOL_GPL(virtio_transport_notify_set_rcvlowat);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Asias He");
MODULE_DESCRIPTION("common code for virtio vsock");
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