static int recv_stream(struct kiocb *iocb, struct socket *sock,
struct msghdr *m, size_t buf_len, int flags)
{
struct sock *sk = sock->sk;
struct tipc_port *tport = tipc_sk_port(sk);
struct sk_buff *buf;
struct tipc_msg *msg;
long timeout;
unsigned int sz;
int sz_to_copy, target, needed;
int sz_copied = 0;
u32 err;
int res = 0;
/* Catch invalid receive attempts */
if (unlikely(!buf_len))
return -EINVAL;
lock_sock(sk);
if (unlikely((sock->state == SS_UNCONNECTED) ||
(sock->state == SS_CONNECTING))) {
res = -ENOTCONN;
goto exit;
}
/* will be updated in set_orig_addr() if needed */
m->msg_namelen = 0;
target = sock_rcvlowat(sk, flags & MSG_WAITALL, buf_len);
timeout = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
restart:
/* Look for a message in receive queue; wait if necessary */
while (skb_queue_empty(&sk->sk_receive_queue)) {
if (sock->state == SS_DISCONNECTING) {
res = -ENOTCONN;
goto exit;
}
if (timeout <= 0L) {
res = timeout ? timeout : -EWOULDBLOCK;
goto exit;
}
release_sock(sk);
timeout = wait_event_interruptible_timeout(*sk_sleep(sk),
tipc_rx_ready(sock),
timeout);
lock_sock(sk);
}
/* Look at first message in receive queue */
buf = skb_peek(&sk->sk_receive_queue);
msg = buf_msg(buf);
sz = msg_data_sz(msg);
err = msg_errcode(msg);
/* Discard an empty non-errored message & try again */
if ((!sz) && (!err)) {
advance_rx_queue(sk);
goto restart;
}
/* Optionally capture sender's address & ancillary data of first msg */
if (sz_copied == 0) {
set_orig_addr(m, msg);
res = anc_data_recv(m, msg, tport);
if (res)
goto exit;
}
/* Capture message data (if valid) & compute return value (always) */
if (!err) {
u32 offset = (u32)(unsigned long)(TIPC_SKB_CB(buf)->handle);
sz -= offset;
needed = (buf_len - sz_copied);
sz_to_copy = (sz <= needed) ? sz : needed;
res = skb_copy_datagram_iovec(buf, msg_hdr_sz(msg) + offset,
m->msg_iov, sz_to_copy);
if (res)
goto exit;
sz_copied += sz_to_copy;
if (sz_to_copy < sz) {
if (!(flags & MSG_PEEK))
TIPC_SKB_CB(buf)->handle =
(void *)(unsigned long)(offset + sz_to_copy);
goto exit;
}
} else {
if (sz_copied != 0)
goto exit; /* can't add error msg to valid data */
if ((err == TIPC_CONN_SHUTDOWN) || m->msg_control)
res = 0;
else
res = -ECONNRESET;
}
/* Consume received message (optional) */
if (likely(!(flags & MSG_PEEK))) {
if (unlikely(++tport->conn_unacked >= TIPC_FLOW_CONTROL_WIN))
tipc_acknowledge(tport->ref, tport->conn_unacked);
advance_rx_queue(sk);
}
/* Loop around if more data is required */
if ((sz_copied < buf_len) && /* didn't get all requested data */
(!skb_queue_empty(&sk->sk_receive_queue) ||
(sz_copied < target)) && /* and more is ready or required */
(!(flags & MSG_PEEK)) && /* and aren't just peeking at data */
(!err)) /* and haven't reached a FIN */
goto restart;
exit:
release_sock(sk);
return sz_copied ? sz_copied : res;
}
static int
vsock_stream_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
int flags)
{
struct sock *sk;
struct vsock_sock *vsk;
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);
err = 0;
lock_sock(sk);
if (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 int recv_stream(struct kiocb *iocb, struct socket *sock,
struct msghdr *m, size_t buf_len, int flags)
{
struct sock *sk = sock->sk;
struct tipc_port *tport = tipc_sk_port(sk);
struct sk_buff *buf;
struct tipc_msg *msg;
unsigned int sz;
int sz_to_copy, target, needed;
int sz_copied = 0;
char __user *crs = m->msg_iov->iov_base;
unsigned char *buf_crs;
u32 err;
int res = 0;
/* Catch invalid receive attempts */
if (m->msg_iovlen != 1)
return -EOPNOTSUPP; /* Don't do multiple iovec entries yet */
if (unlikely(!buf_len))
return -EINVAL;
lock_sock(sk);
if (unlikely((sock->state == SS_UNCONNECTED) ||
(sock->state == SS_CONNECTING))) {
res = -ENOTCONN;
goto exit;
}
target = sock_rcvlowat(sk, flags & MSG_WAITALL, buf_len);
restart:
/* Look for a message in receive queue; wait if necessary */
while (skb_queue_empty(&sk->sk_receive_queue)) {
if (sock->state == SS_DISCONNECTING) {
res = -ENOTCONN;
goto exit;
}
if (flags & MSG_DONTWAIT) {
res = -EWOULDBLOCK;
goto exit;
}
release_sock(sk);
res = wait_event_interruptible(*sk_sleep(sk),
(!skb_queue_empty(&sk->sk_receive_queue) ||
(sock->state == SS_DISCONNECTING)));
lock_sock(sk);
if (res)
goto exit;
}
/* Look at first message in receive queue */
buf = skb_peek(&sk->sk_receive_queue);
msg = buf_msg(buf);
sz = msg_data_sz(msg);
err = msg_errcode(msg);
/* Discard an empty non-errored message & try again */
if ((!sz) && (!err)) {
advance_rx_queue(sk);
goto restart;
}
/* Optionally capture sender's address & ancillary data of first msg */
if (sz_copied == 0) {
set_orig_addr(m, msg);
res = anc_data_recv(m, msg, tport);
if (res)
goto exit;
}
/* Capture message data (if valid) & compute return value (always) */
if (!err) {
buf_crs = (unsigned char *)(TIPC_SKB_CB(buf)->handle);
sz = (unsigned char *)msg + msg_size(msg) - buf_crs;
needed = (buf_len - sz_copied);
sz_to_copy = (sz <= needed) ? sz : needed;
if (unlikely(copy_to_user(crs, buf_crs, sz_to_copy))) {
res = -EFAULT;
goto exit;
}
sz_copied += sz_to_copy;
if (sz_to_copy < sz) {
if (!(flags & MSG_PEEK))
TIPC_SKB_CB(buf)->handle = buf_crs + sz_to_copy;
goto exit;
}
crs += sz_to_copy;
} else {
if (sz_copied != 0)
goto exit; /* can't add error msg to valid data */
if ((err == TIPC_CONN_SHUTDOWN) || m->msg_control)
res = 0;
else
res = -ECONNRESET;
}
/* Consume received message (optional) */
if (likely(!(flags & MSG_PEEK))) {
if (unlikely(++tport->conn_unacked >= TIPC_FLOW_CONTROL_WIN))
tipc_acknowledge(tport->ref, tport->conn_unacked);
advance_rx_queue(sk);
}
/* Loop around if more data is required */
if ((sz_copied < buf_len) && /* didn't get all requested data */
(!skb_queue_empty(&sk->sk_receive_queue) ||
(sz_copied < target)) && /* and more is ready or required */
(!(flags & MSG_PEEK)) && /* and aren't just peeking at data */
(!err)) /* and haven't reached a FIN */
goto restart;
exit:
release_sock(sk);
return sz_copied ? sz_copied : res;
}
