linux/net/vmw_vsock/virtio_transport_common.c
Stefano Garzarella 3fe356d58e vsock/virtio: discard packets only when socket is really closed
Starting from commit 8692cefc43 ("virtio_vsock: Fix race condition
in virtio_transport_recv_pkt"), we discard packets in
virtio_transport_recv_pkt() if the socket has been released.

When the socket is connected, we schedule a delayed work to wait the
RST packet from the other peer, also if SHUTDOWN_MASK is set in
sk->sk_shutdown.
This is done to complete the virtio-vsock shutdown algorithm, releasing
the port assigned to the socket definitively only when the other peer
has consumed all the packets.

If we discard the RST packet received, the socket will be closed only
when the VSOCK_CLOSE_TIMEOUT is reached.

Sergio discovered the issue while running ab(1) HTTP benchmark using
libkrun [1] and observing a latency increase with that commit.

To avoid this issue, we discard packet only if the socket is really
closed (SOCK_DONE flag is set).
We also set SOCK_DONE in virtio_transport_release() when we don't need
to wait any packets from the other peer (we didn't schedule the delayed
work). In this case we remove the socket from the vsock lists, releasing
the port assigned.

[1] https://github.com/containers/libkrun

Fixes: 8692cefc43 ("virtio_vsock: Fix race condition in virtio_transport_recv_pkt")
Cc: justin.he@arm.com
Reported-by: Sergio Lopez <slp@redhat.com>
Tested-by: Sergio Lopez <slp@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Jia He <justin.he@arm.com>
Link: https://lore.kernel.org/r/20201120104736.73749-1-sgarzare@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-23 16:36:29 -08:00

1196 lines
28 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* common code for virtio vsock
*
* Copyright (C) 2013-2015 Red Hat, Inc.
* Author: Asias He <asias@redhat.com>
* Stefan Hajnoczi <stefanha@redhat.com>
*/
#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 struct virtio_vsock_pkt *
virtio_transport_alloc_pkt(struct virtio_vsock_pkt_info *info,
size_t len,
u32 src_cid,
u32 src_port,
u32 dst_cid,
u32 dst_port)
{
struct virtio_vsock_pkt *pkt;
int err;
pkt = kzalloc(sizeof(*pkt), GFP_KERNEL);
if (!pkt)
return NULL;
pkt->hdr.type = cpu_to_le16(info->type);
pkt->hdr.op = cpu_to_le16(info->op);
pkt->hdr.src_cid = cpu_to_le64(src_cid);
pkt->hdr.dst_cid = cpu_to_le64(dst_cid);
pkt->hdr.src_port = cpu_to_le32(src_port);
pkt->hdr.dst_port = cpu_to_le32(dst_port);
pkt->hdr.flags = cpu_to_le32(info->flags);
pkt->len = len;
pkt->hdr.len = cpu_to_le32(len);
pkt->reply = info->reply;
pkt->vsk = info->vsk;
if (info->msg && len > 0) {
pkt->buf = kmalloc(len, GFP_KERNEL);
if (!pkt->buf)
goto out_pkt;
pkt->buf_len = len;
err = memcpy_from_msg(pkt->buf, info->msg, len);
if (err)
goto out;
}
trace_virtio_transport_alloc_pkt(src_cid, src_port,
dst_cid, dst_port,
len,
info->type,
info->op,
info->flags);
return pkt;
out:
kfree(pkt->buf);
out_pkt:
kfree(pkt);
return NULL;
}
/* Packet capture */
static struct sk_buff *virtio_transport_build_skb(void *opaque)
{
struct virtio_vsock_pkt *pkt = opaque;
struct af_vsockmon_hdr *hdr;
struct sk_buff *skb;
size_t payload_len;
void *payload_buf;
/* 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.
*/
payload_len = le32_to_cpu(pkt->hdr.len);
payload_buf = pkt->buf + pkt->off;
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) {
skb_put_data(skb, payload_buf, payload_len);
}
return skb;
}
void virtio_transport_deliver_tap_pkt(struct virtio_vsock_pkt *pkt)
{
if (pkt->tap_delivered)
return;
vsock_deliver_tap(virtio_transport_build_skb, pkt);
pkt->tap_delivered = true;
}
EXPORT_SYMBOL_GPL(virtio_transport_deliver_tap_pkt);
/* 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 src_cid, src_port, dst_cid, dst_port;
const struct virtio_transport *t_ops;
struct virtio_vsock_sock *vvs;
struct virtio_vsock_pkt *pkt;
u32 pkt_len = info->pkt_len;
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;
/* we can send less than pkt_len bytes */
if (pkt_len > VIRTIO_VSOCK_MAX_PKT_BUF_SIZE)
pkt_len = VIRTIO_VSOCK_MAX_PKT_BUF_SIZE;
/* 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;
pkt = virtio_transport_alloc_pkt(info, pkt_len,
src_cid, src_port,
dst_cid, dst_port);
if (!pkt) {
virtio_transport_put_credit(vvs, pkt_len);
return -ENOMEM;
}
virtio_transport_inc_tx_pkt(vvs, pkt);
return t_ops->send_pkt(pkt);
}
static bool virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs,
struct virtio_vsock_pkt *pkt)
{
if (vvs->rx_bytes + pkt->len > vvs->buf_alloc)
return false;
vvs->rx_bytes += pkt->len;
return true;
}
static void virtio_transport_dec_rx_pkt(struct virtio_vsock_sock *vvs,
struct virtio_vsock_pkt *pkt)
{
vvs->rx_bytes -= pkt->len;
vvs->fwd_cnt += pkt->len;
}
void virtio_transport_inc_tx_pkt(struct virtio_vsock_sock *vvs, struct virtio_vsock_pkt *pkt)
{
spin_lock_bh(&vvs->rx_lock);
vvs->last_fwd_cnt = vvs->fwd_cnt;
pkt->hdr.fwd_cnt = cpu_to_le32(vvs->fwd_cnt);
pkt->hdr.buf_alloc = cpu_to_le32(vvs->buf_alloc);
spin_unlock_bh(&vvs->rx_lock);
}
EXPORT_SYMBOL_GPL(virtio_transport_inc_tx_pkt);
u32 virtio_transport_get_credit(struct virtio_vsock_sock *vvs, u32 credit)
{
u32 ret;
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;
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)
{
spin_lock_bh(&vvs->tx_lock);
vvs->tx_cnt -= 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,
int type,
struct virtio_vsock_hdr *hdr)
{
struct virtio_vsock_pkt_info info = {
.op = VIRTIO_VSOCK_OP_CREDIT_UPDATE,
.type = type,
.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 virtio_vsock_pkt *pkt;
size_t bytes, total = 0, off;
int err = -EFAULT;
spin_lock_bh(&vvs->rx_lock);
list_for_each_entry(pkt, &vvs->rx_queue, list) {
off = pkt->off;
if (total == len)
break;
while (total < len && off < pkt->len) {
bytes = len - total;
if (bytes > pkt->len - off)
bytes = pkt->len - off;
/* sk_lock is held by caller so no one else can dequeue.
* Unlock rx_lock since memcpy_to_msg() may sleep.
*/
spin_unlock_bh(&vvs->rx_lock);
err = memcpy_to_msg(msg, pkt->buf + off, bytes);
if (err)
goto out;
spin_lock_bh(&vvs->rx_lock);
total += bytes;
off += bytes;
}
}
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;
struct virtio_vsock_pkt *pkt;
size_t bytes, total = 0;
u32 free_space;
int err = -EFAULT;
spin_lock_bh(&vvs->rx_lock);
while (total < len && !list_empty(&vvs->rx_queue)) {
pkt = list_first_entry(&vvs->rx_queue,
struct virtio_vsock_pkt, list);
bytes = len - total;
if (bytes > pkt->len - pkt->off)
bytes = pkt->len - pkt->off;
/* sk_lock is held by caller so no one else can dequeue.
* Unlock rx_lock since memcpy_to_msg() may sleep.
*/
spin_unlock_bh(&vvs->rx_lock);
err = memcpy_to_msg(msg, pkt->buf + pkt->off, bytes);
if (err)
goto out;
spin_lock_bh(&vvs->rx_lock);
total += bytes;
pkt->off += bytes;
if (pkt->off == pkt->len) {
virtio_transport_dec_rx_pkt(vvs, pkt);
list_del(&pkt->list);
virtio_transport_free_pkt(pkt);
}
}
free_space = vvs->buf_alloc - (vvs->fwd_cnt - vvs->last_fwd_cnt);
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.
*/
if (free_space < VIRTIO_VSOCK_MAX_PKT_BUF_SIZE) {
virtio_transport_send_credit_update(vsk,
VIRTIO_VSOCK_TYPE_STREAM,
NULL);
}
return total;
out:
if (total)
err = total;
return err;
}
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);
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);
static s64 virtio_transport_has_space(struct vsock_sock *vsk)
{
struct virtio_vsock_sock *vvs = vsk->trans;
s64 bytes;
bytes = 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);
INIT_LIST_HEAD(&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, VIRTIO_VSOCK_TYPE_STREAM,
NULL);
}
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)
{
if (vsock_stream_has_data(vsk))
*data_ready_now = true;
else
*data_ready_now = false;
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,
.type = VIRTIO_VSOCK_TYPE_STREAM,
.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,
.type = VIRTIO_VSOCK_TYPE_STREAM,
.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,
.type = VIRTIO_VSOCK_TYPE_STREAM,
.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);
static int virtio_transport_reset(struct vsock_sock *vsk,
struct virtio_vsock_pkt *pkt)
{
struct virtio_vsock_pkt_info info = {
.op = VIRTIO_VSOCK_OP_RST,
.type = VIRTIO_VSOCK_TYPE_STREAM,
.reply = !!pkt,
.vsk = vsk,
};
/* Send RST only if the original pkt is not a RST pkt */
if (pkt && le16_to_cpu(pkt->hdr.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 virtio_vsock_pkt *pkt)
{
struct virtio_vsock_pkt *reply;
struct virtio_vsock_pkt_info info = {
.op = VIRTIO_VSOCK_OP_RST,
.type = le16_to_cpu(pkt->hdr.type),
.reply = true,
};
/* Send RST only if the original pkt is not a RST pkt */
if (le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
return 0;
reply = virtio_transport_alloc_pkt(&info, 0,
le64_to_cpu(pkt->hdr.dst_cid),
le32_to_cpu(pkt->hdr.dst_port),
le64_to_cpu(pkt->hdr.src_cid),
le32_to_cpu(pkt->hdr.src_port));
if (!reply)
return -ENOMEM;
if (!t) {
virtio_transport_free_pkt(reply);
return -ENOTCONN;
}
return t->send_pkt(reply);
}
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;
vsock_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 virtio_vsock_sock *vvs = vsk->trans;
struct virtio_vsock_pkt *pkt, *tmp;
struct sock *sk = &vsk->sk;
bool remove_sock = true;
if (sk->sk_type == SOCK_STREAM)
remove_sock = virtio_transport_close(vsk);
list_for_each_entry_safe(pkt, tmp, &vvs->rx_queue, list) {
list_del(&pkt->list);
virtio_transport_free_pkt(pkt);
}
if (remove_sock) {
sock_set_flag(sk, SOCK_DONE);
vsock_remove_sock(vsk);
}
}
EXPORT_SYMBOL_GPL(virtio_transport_release);
static int
virtio_transport_recv_connecting(struct sock *sk,
struct virtio_vsock_pkt *pkt)
{
struct vsock_sock *vsk = vsock_sk(sk);
int err;
int skerr;
switch (le16_to_cpu(pkt->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, pkt);
sk->sk_state = TCP_CLOSE;
sk->sk_err = skerr;
sk->sk_error_report(sk);
return err;
}
static void
virtio_transport_recv_enqueue(struct vsock_sock *vsk,
struct virtio_vsock_pkt *pkt)
{
struct virtio_vsock_sock *vvs = vsk->trans;
bool can_enqueue, free_pkt = false;
pkt->len = le32_to_cpu(pkt->hdr.len);
pkt->off = 0;
spin_lock_bh(&vvs->rx_lock);
can_enqueue = virtio_transport_inc_rx_pkt(vvs, pkt);
if (!can_enqueue) {
free_pkt = true;
goto out;
}
/* 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 (pkt->len <= GOOD_COPY_LEN && !list_empty(&vvs->rx_queue)) {
struct virtio_vsock_pkt *last_pkt;
last_pkt = list_last_entry(&vvs->rx_queue,
struct virtio_vsock_pkt, list);
/* If there is space in the last packet queued, we copy the
* new packet in its buffer.
*/
if (pkt->len <= last_pkt->buf_len - last_pkt->len) {
memcpy(last_pkt->buf + last_pkt->len, pkt->buf,
pkt->len);
last_pkt->len += pkt->len;
free_pkt = true;
goto out;
}
}
list_add_tail(&pkt->list, &vvs->rx_queue);
out:
spin_unlock_bh(&vvs->rx_lock);
if (free_pkt)
virtio_transport_free_pkt(pkt);
}
static int
virtio_transport_recv_connected(struct sock *sk,
struct virtio_vsock_pkt *pkt)
{
struct vsock_sock *vsk = vsock_sk(sk);
int err = 0;
switch (le16_to_cpu(pkt->hdr.op)) {
case VIRTIO_VSOCK_OP_RW:
virtio_transport_recv_enqueue(vsk, pkt);
sk->sk_data_ready(sk);
return err;
case VIRTIO_VSOCK_OP_CREDIT_UPDATE:
sk->sk_write_space(sk);
break;
case VIRTIO_VSOCK_OP_SHUTDOWN:
if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SHUTDOWN_RCV)
vsk->peer_shutdown |= RCV_SHUTDOWN;
if (le32_to_cpu(pkt->hdr.flags) & VIRTIO_VSOCK_SHUTDOWN_SEND)
vsk->peer_shutdown |= SEND_SHUTDOWN;
if (vsk->peer_shutdown == SHUTDOWN_MASK &&
vsock_stream_has_data(vsk) <= 0 &&
!sock_flag(sk, SOCK_DONE)) {
(void)virtio_transport_reset(vsk, NULL);
virtio_transport_do_close(vsk, true);
}
if (le32_to_cpu(pkt->hdr.flags))
sk->sk_state_change(sk);
break;
case VIRTIO_VSOCK_OP_RST:
virtio_transport_do_close(vsk, true);
break;
default:
err = -EINVAL;
break;
}
virtio_transport_free_pkt(pkt);
return err;
}
static void
virtio_transport_recv_disconnecting(struct sock *sk,
struct virtio_vsock_pkt *pkt)
{
struct vsock_sock *vsk = vsock_sk(sk);
if (le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST)
virtio_transport_do_close(vsk, true);
}
static int
virtio_transport_send_response(struct vsock_sock *vsk,
struct virtio_vsock_pkt *pkt)
{
struct virtio_vsock_pkt_info info = {
.op = VIRTIO_VSOCK_OP_RESPONSE,
.type = VIRTIO_VSOCK_TYPE_STREAM,
.remote_cid = le64_to_cpu(pkt->hdr.src_cid),
.remote_port = le32_to_cpu(pkt->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 virtio_vsock_pkt *pkt)
{
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(pkt->hdr.buf_alloc);
vvs->peer_fwd_cnt = le32_to_cpu(pkt->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 virtio_vsock_pkt *pkt,
struct virtio_transport *t)
{
struct vsock_sock *vsk = vsock_sk(sk);
struct vsock_sock *vchild;
struct sock *child;
int ret;
if (le16_to_cpu(pkt->hdr.op) != VIRTIO_VSOCK_OP_REQUEST) {
virtio_transport_reset_no_sock(t, pkt);
return -EINVAL;
}
if (sk_acceptq_is_full(sk)) {
virtio_transport_reset_no_sock(t, pkt);
return -ENOMEM;
}
child = vsock_create_connected(sk);
if (!child) {
virtio_transport_reset_no_sock(t, pkt);
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(pkt->hdr.dst_cid),
le32_to_cpu(pkt->hdr.dst_port));
vsock_addr_init(&vchild->remote_addr, le64_to_cpu(pkt->hdr.src_cid),
le32_to_cpu(pkt->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, pkt);
sock_put(child);
return ret;
}
if (virtio_transport_space_update(child, pkt))
child->sk_write_space(child);
vsock_insert_connected(vchild);
vsock_enqueue_accept(sk, child);
virtio_transport_send_response(vchild, pkt);
release_sock(child);
sk->sk_data_ready(sk);
return 0;
}
/* 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 virtio_vsock_pkt *pkt)
{
struct sockaddr_vm src, dst;
struct vsock_sock *vsk;
struct sock *sk;
bool space_available;
vsock_addr_init(&src, le64_to_cpu(pkt->hdr.src_cid),
le32_to_cpu(pkt->hdr.src_port));
vsock_addr_init(&dst, le64_to_cpu(pkt->hdr.dst_cid),
le32_to_cpu(pkt->hdr.dst_port));
trace_virtio_transport_recv_pkt(src.svm_cid, src.svm_port,
dst.svm_cid, dst.svm_port,
le32_to_cpu(pkt->hdr.len),
le16_to_cpu(pkt->hdr.type),
le16_to_cpu(pkt->hdr.op),
le32_to_cpu(pkt->hdr.flags),
le32_to_cpu(pkt->hdr.buf_alloc),
le32_to_cpu(pkt->hdr.fwd_cnt));
if (le16_to_cpu(pkt->hdr.type) != VIRTIO_VSOCK_TYPE_STREAM) {
(void)virtio_transport_reset_no_sock(t, pkt);
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, pkt);
goto free_pkt;
}
}
vsk = vsock_sk(sk);
space_available = virtio_transport_space_update(sk, pkt);
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, pkt);
release_sock(sk);
sock_put(sk);
goto free_pkt;
}
/* Update CID in case it has changed after a transport reset event */
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, pkt, t);
virtio_transport_free_pkt(pkt);
break;
case TCP_SYN_SENT:
virtio_transport_recv_connecting(sk, pkt);
virtio_transport_free_pkt(pkt);
break;
case TCP_ESTABLISHED:
virtio_transport_recv_connected(sk, pkt);
break;
case TCP_CLOSING:
virtio_transport_recv_disconnecting(sk, pkt);
virtio_transport_free_pkt(pkt);
break;
default:
(void)virtio_transport_reset_no_sock(t, pkt);
virtio_transport_free_pkt(pkt);
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:
virtio_transport_free_pkt(pkt);
}
EXPORT_SYMBOL_GPL(virtio_transport_recv_pkt);
void virtio_transport_free_pkt(struct virtio_vsock_pkt *pkt)
{
kfree(pkt->buf);
kfree(pkt);
}
EXPORT_SYMBOL_GPL(virtio_transport_free_pkt);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Asias He");
MODULE_DESCRIPTION("common code for virtio vsock");