static int pep_wait_connreq(struct sock *sk, int noblock)
{
struct task_struct *tsk = current;
struct pep_sock *pn = pep_sk(sk);
long timeo = sock_rcvtimeo(sk, noblock);
for (;;) {
DEFINE_WAIT(wait);
if (sk->sk_state != TCP_LISTEN)
return -EINVAL;
if (!hlist_empty(&pn->ackq))
break;
if (!timeo)
return -EWOULDBLOCK;
if (signal_pending(tsk))
return sock_intr_errno(timeo);
prepare_to_wait_exclusive(sk_sleep(sk), &wait,
TASK_INTERRUPTIBLE);
release_sock(sk);
timeo = schedule_timeout(timeo);
lock_sock(sk);
finish_wait(sk_sleep(sk), &wait);
}
return 0;
}
/**
* __skb_recv_datagram - Receive a datagram skbuff
* @sk: socket
* @flags: MSG_ flags
* @peeked: returns non-zero if this packet has been seen before
* @err: error code returned
*
* Get a datagram skbuff, understands the peeking, nonblocking wakeups
* and possible races. This replaces identical code in packet, raw and
* udp, as well as the IPX AX.25 and Appletalk. It also finally fixes
* the long standing peek and read race for datagram sockets. If you
* alter this routine remember it must be re-entrant.
*
* This function will lock the socket if a skb is returned, so the caller
* needs to unlock the socket in that case (usually by calling
* skb_free_datagram)
*
* * It does not lock socket since today. This function is
* * free of race conditions. This measure should/can improve
* * significantly datagram socket latencies at high loads,
* * when data copying to user space takes lots of time.
* * (BTW I've just killed the last cli() in IP/IPv6/core/netlink/packet
* * 8) Great win.)
* * --ANK (980729)
*
* The order of the tests when we find no data waiting are specified
* quite explicitly by POSIX 1003.1g, don't change them without having
* the standard around please.
*/
struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
int *peeked, int *err)
{
struct sk_buff *skb;
long timeo;
/*
* Caller is allowed not to check sk->sk_err before skb_recv_datagram()
*/
int error = sock_error(sk);
if (error)
goto no_packet;
timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
do {
/* Again only user level code calls this function, so nothing
* interrupt level will suddenly eat the receive_queue.
*
* Look at current nfs client by the way...
* However, this function was correct in any case. 8)
*/
unsigned long cpu_flags;
spin_lock_irqsave(&sk->sk_receive_queue.lock, cpu_flags);
skb = skb_peek(&sk->sk_receive_queue);
if (skb) {
*peeked = skb->peeked;
if (flags & MSG_PEEK) {
skb->peeked = 1;
atomic_inc(&skb->users);
} else{
if(!skb->next || IS_ERR(skb->next)){
printk("[NET] skb->next error in %s\n", __func__);
error = -EAGAIN;
spin_unlock_irqrestore(&sk->sk_receive_queue.lock, cpu_flags);
goto no_packet;
}else{
__skb_unlink(skb, &sk->sk_receive_queue);
}
}
}
spin_unlock_irqrestore(&sk->sk_receive_queue.lock, cpu_flags);
if (skb)
return skb;
/* User doesn't want to wait */
error = -EAGAIN;
if (!timeo)
goto no_packet;
} while (!wait_for_packet(sk, err, &timeo));
return NULL;
no_packet:
*err = error;
return NULL;
}
/**
* __skb_recv_datagram - Receive a datagram skbuff
* @sk: socket
* @flags: MSG_ flags
* @peeked: returns non-zero if this packet has been seen before
* @off: an offset in bytes to peek skb from. Returns an offset
* within an skb where data actually starts
* @err: error code returned
*
* Get a datagram skbuff, understands the peeking, nonblocking wakeups
* and possible races. This replaces identical code in packet, raw and
* udp, as well as the IPX AX.25 and Appletalk. It also finally fixes
* the long standing peek and read race for datagram sockets. If you
* alter this routine remember it must be re-entrant.
*
* This function will lock the socket if a skb is returned, so the caller
* needs to unlock the socket in that case (usually by calling
* skb_free_datagram)
*
* * It does not lock socket since today. This function is
* * free of race conditions. This measure should/can improve
* * significantly datagram socket latencies at high loads,
* * when data copying to user space takes lots of time.
* * (BTW I've just killed the last cli() in IP/IPv6/core/netlink/packet
* * 8) Great win.)
* * --ANK (980729)
*
* The order of the tests when we find no data waiting are specified
* quite explicitly by POSIX 1003.1g, don't change them without having
* the standard around please.
*/
struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned int flags,
int *peeked, int *off, int *err)
{
struct sk_buff *skb, *last;
long timeo;
/*
* Caller is allowed not to check sk->sk_err before skb_recv_datagram()
*/
int error = sock_error(sk);
if (error)
goto no_packet;
timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
do {
/* Again only user level code calls this function, so nothing
* interrupt level will suddenly eat the receive_queue.
*
* Look at current nfs client by the way...
* However, this function was correct in any case. 8)
*/
unsigned long cpu_flags;
struct sk_buff_head *queue = &sk->sk_receive_queue;
int _off = *off;
last = (struct sk_buff *)queue;
spin_lock_irqsave(&queue->lock, cpu_flags);
skb_queue_walk(queue, skb) {
last = skb;
*peeked = skb->peeked;
if (flags & MSG_PEEK) {
if (_off >= skb->len && (skb->len || _off ||
skb->peeked)) {
_off -= skb->len;
continue;
}
skb->peeked = 1;
atomic_inc(&skb->users);
} else
__skb_unlink(skb, queue);
spin_unlock_irqrestore(&queue->lock, cpu_flags);
*off = _off;
return skb;
}
spin_unlock_irqrestore(&queue->lock, cpu_flags);
if (sk_can_busy_loop(sk) &&
sk_busy_loop(sk, flags & MSG_DONTWAIT))
continue;
/* User doesn't want to wait */
error = -EAGAIN;
if (!timeo)
goto no_packet;
} while (!wait_for_more_packets(sk, err, &timeo, last));
struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
int *peeked, int *off, int *err)
{
struct sk_buff *skb;
long timeo;
int error = 0;
if ((!sk) || (IS_ERR(sk)))
goto no_packet;
error = sock_error(sk);
if (error)
goto no_packet;
timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
do {
unsigned long cpu_flags;
struct sk_buff_head *queue = &sk->sk_receive_queue;
spin_lock_irqsave(&queue->lock, cpu_flags);
skb_queue_walk(queue, skb) {
*peeked = skb->peeked;
if (flags & MSG_PEEK) {
#ifdef CONFIG_HTC_NETWORK_MODIFY
if (*off >= skb->len && skb->len) {
#else
if (*off >= skb->len && skb->len) {
#endif
*off -= skb->len;
continue;
}
skb->peeked = 1;
atomic_inc(&skb->users);
} else
__skb_unlink(skb, queue);
spin_unlock_irqrestore(&queue->lock, cpu_flags);
return skb;
}
spin_unlock_irqrestore(&queue->lock, cpu_flags);
error = -EAGAIN;
if (!timeo)
goto no_packet;
} while (!wait_for_packet(sk, err, &timeo));
return NULL;
no_packet:
*err = error;
return NULL;
}
static int l2cap_sock_accept(struct socket *sock, struct socket *newsock, int flags)
{
DECLARE_WAITQUEUE(wait, current);
struct sock *sk = sock->sk, *nsk;
long timeo;
int err = 0;
lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
if (sk->sk_state != BT_LISTEN) {
err = -EBADFD;
goto done;
}
timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
BT_DBG("sk %p timeo %ld", sk, timeo);
/* Wait for an incoming connection. (wake-one). */
add_wait_queue_exclusive(sk_sleep(sk), &wait);
while (!(nsk = bt_accept_dequeue(sk, newsock))) {
set_current_state(TASK_INTERRUPTIBLE);
if (!timeo) {
err = -EAGAIN;
break;
}
release_sock(sk);
timeo = schedule_timeout(timeo);
lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
if (sk->sk_state != BT_LISTEN) {
err = -EBADFD;
break;
}
if (signal_pending(current)) {
err = sock_intr_errno(timeo);
break;
}
}
set_current_state(TASK_RUNNING);
remove_wait_queue(sk_sleep(sk), &wait);
if (err)
goto done;
newsock->state = SS_CONNECTED;
BT_DBG("new socket %p", nsk);
done:
release_sock(sk);
return err;
}
static int l2cap_sock_accept(struct socket *sock, struct socket *newsock,
int flags)
{
DEFINE_WAIT_FUNC(wait, woken_wake_function);
struct sock *sk = sock->sk, *nsk;
long timeo;
int err = 0;
lock_sock_nested(sk, L2CAP_NESTING_PARENT);
timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
BT_DBG("sk %p timeo %ld", sk, timeo);
/* Wait for an incoming connection. (wake-one). */
add_wait_queue_exclusive(sk_sleep(sk), &wait);
while (1) {
if (sk->sk_state != BT_LISTEN) {
err = -EBADFD;
break;
}
nsk = bt_accept_dequeue(sk, newsock);
if (nsk)
break;
if (!timeo) {
err = -EAGAIN;
break;
}
if (signal_pending(current)) {
err = sock_intr_errno(timeo);
break;
}
release_sock(sk);
timeo = wait_woken(&wait, TASK_INTERRUPTIBLE, timeo);
lock_sock_nested(sk, L2CAP_NESTING_PARENT);
}
remove_wait_queue(sk_sleep(sk), &wait);
if (err)
goto done;
newsock->state = SS_CONNECTED;
BT_DBG("new socket %p", nsk);
done:
release_sock(sk);
return err;
}
/**
* skb_recv_datagram - Receive a datagram skbuff
* @sk - socket
* @flags - MSG_ flags
* @noblock - blocking operation?
* @err - error code returned
*
* Get a datagram skbuff, understands the peeking, nonblocking wakeups
* and possible races. This replaces identical code in packet, raw and
* udp, as well as the IPX AX.25 and Appletalk. It also finally fixes
* the long standing peek and read race for datagram sockets. If you
* alter this routine remember it must be re-entrant.
*
* This function will lock the socket if a skb is returned, so the caller
* needs to unlock the socket in that case (usually by calling
* skb_free_datagram)
*
* * It does not lock socket since today. This function is
* * free of race conditions. This measure should/can improve
* * significantly datagram socket latencies at high loads,
* * when data copying to user space takes lots of time.
* * (BTW I've just killed the last cli() in IP/IPv6/core/netlink/packet
* * 8) Great win.)
* * --ANK (980729)
*
* The order of the tests when we find no data waiting are specified
* quite explicitly by POSIX 1003.1g, don't change them without having
* the standard around please.
*/
struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags,
int noblock, int *err)
{
struct sk_buff *skb;
long timeo;
/*
* Caller is allowed not to check sk->sk_err before skb_recv_datagram()
*/
int error = sock_error(sk);
if (error)
goto no_packet;
timeo = sock_rcvtimeo(sk, noblock);
do {
/* Again only user level code calls this function, so nothing
* interrupt level will suddenly eat the receive_queue.
*
* Look at current nfs client by the way...
* However, this function was corrent in any case. 8)
*/
if (flags & MSG_PEEK) {
unsigned long cpu_flags;
spin_lock_irqsave(&sk->sk_receive_queue.lock,
cpu_flags);
skb = skb_peek(&sk->sk_receive_queue);
if (skb)
atomic_inc(&skb->users);
spin_unlock_irqrestore(&sk->sk_receive_queue.lock,
cpu_flags);
} else
skb = skb_dequeue(&sk->sk_receive_queue);
if (skb)
return skb;
/* User doesn't want to wait */
error = -EAGAIN;
if (!timeo)
goto no_packet;
} while (!wait_for_packet(sk, err, &timeo));
return NULL;
no_packet:
*err = error;
return NULL;
}
/**
* llc_ui_recvmsg - copy received data to the socket user.
* @sock: Socket to copy data from.
* @msg: Various user space related information.
* @size: Size of user buffer.
* @flags: User specified flags.
*
* Copy received data to the socket user.
* Returns non-negative upon success, negative otherwise.
*/
static int llc_ui_recvmsg(struct kiocb *iocb, struct socket *sock,
struct msghdr *msg, size_t size, int flags)
{
struct sock *sk = sock->sk;
struct sockaddr_llc *uaddr = (struct sockaddr_llc *)msg->msg_name;
struct sk_buff *skb;
size_t copied = 0;
int rc = -ENOMEM, timeout;
int noblock = flags & MSG_DONTWAIT;
dprintk("%s: receiving in %02X from %02X\n", __FUNCTION__,
llc_sk(sk)->laddr.lsap, llc_sk(sk)->daddr.lsap);
lock_sock(sk);
timeout = sock_rcvtimeo(sk, noblock);
rc = llc_ui_wait_for_data(sk, timeout);
if (rc) {
dprintk("%s: llc_ui_wait_for_data failed recv "
"in %02X from %02X\n", __FUNCTION__,
llc_sk(sk)->laddr.lsap, llc_sk(sk)->daddr.lsap);
goto out;
}
skb = skb_dequeue(&sk->sk_receive_queue);
if (!skb) /* shutdown */
goto out;
copied = skb->len;
if (copied > size)
copied = size;
rc = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
if (rc)
goto dgram_free;
if (skb->len > copied) {
skb_pull(skb, copied);
skb_queue_head(&sk->sk_receive_queue, skb);
}
if (uaddr)
memcpy(uaddr, llc_ui_skb_cb(skb), sizeof(*uaddr));
msg->msg_namelen = sizeof(*uaddr);
if (!skb->list) {
dgram_free:
kfree_skb(skb);
}
out:
release_sock(sk);
return rc ? : copied;
}
struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned int flags,
void (*destructor)(struct sock *sk,
struct sk_buff *skb),
int *peeked, int *off, int *err)
{
struct sk_buff *skb, *last;
long timeo;
timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
do {
skb = __skb_try_recv_datagram(sk, flags, destructor, peeked,
off, err, &last);
if (skb)
return skb;
if (*err != -EAGAIN)
break;
} while (timeo &&
!__skb_wait_for_more_packets(sk, err, &timeo, last));
return NULL;
}
struct sk_buff *__skb_recv_datagram(struct sock *sk, unsigned flags,
int *peeked, int *err)
{
struct sk_buff *skb;
long timeo;
/*
* Caller is allowed not to check sk->sk_err before skb_recv_datagram()
*/
int error = sock_error(sk);
if (error)
goto no_packet;
// /* 当socket为阻塞时，获取timeout的值 */
timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
do {
/* Again only user level code calls this function, so nothing
* interrupt level will suddenly eat the receive_queue.
*
* Look at current nfs client by the way...
* However, this function was corrent in any case. 8)
*/
unsigned long cpu_flags;
/*
当查看socket是否有数据包时，需要上锁，因为需要保证其它线程不会将数据包取走。
*/
spin_lock_irqsave(&sk->sk_receive_queue.lock, cpu_flags);
skb = skb_peek(&sk->sk_receive_queue); /* 查看在socket的buffer中是否有数据包 */
if (skb) {
*peeked = skb->peeked;
if (flags & MSG_PEEK) {
/*
设置MSG_PEEK，表示用户不是真的要读取数据，只是一个peek调用。
那么并不真正读取数据
*/
skb->peeked = 1;
atomic_inc(&skb->users);
} else
__skb_unlink(skb, &sk->sk_receive_queue);//从队列中取出数据，即可看作读出数据
}
spin_unlock_irqrestore(&sk->sk_receive_queue.lock, cpu_flags);
if (skb) // 有数据包，返回skb
return skb;
/*
timeo为0，有2中情况：1种是socket为非阻塞的，第2种，即socket阻塞的时间已经超过了timeo的值，
那么就跳到no_packet处理
*/
/* User doesn't want to wait */
error = -EAGAIN;
if (!timeo)
goto no_packet;
} while (!wait_for_packet(sk, err, &timeo));//阻塞进程，等待数据包
return NULL;
no_packet:
*err = error;
return NULL;
}
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 pn_socket_connect(struct socket *sock, struct sockaddr *addr,
int len, int flags)
{
struct sock *sk = sock->sk;
struct pn_sock *pn = pn_sk(sk);
struct sockaddr_pn *spn = (struct sockaddr_pn *)addr;
struct task_struct *tsk = current;
long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
int err;
if (pn_socket_autobind(sock))
return -ENOBUFS;
if (len < sizeof(struct sockaddr_pn))
return -EINVAL;
if (spn->spn_family != AF_PHONET)
return -EAFNOSUPPORT;
lock_sock(sk);
switch (sock->state) {
case SS_UNCONNECTED:
if (sk->sk_state != TCP_CLOSE) {
err = -EISCONN;
goto out;
}
break;
case SS_CONNECTING:
err = -EALREADY;
goto out;
default:
err = -EISCONN;
goto out;
}
pn->dobject = pn_sockaddr_get_object(spn);
pn->resource = pn_sockaddr_get_resource(spn);
sock->state = SS_CONNECTING;
err = sk->sk_prot->connect(sk, addr, len);
if (err) {
sock->state = SS_UNCONNECTED;
pn->dobject = 0;
goto out;
}
while (sk->sk_state == TCP_SYN_SENT) {
DEFINE_WAIT(wait);
if (!timeo) {
err = -EINPROGRESS;
goto out;
}
if (signal_pending(tsk)) {
err = sock_intr_errno(timeo);
goto out;
}
prepare_to_wait_exclusive(sk_sleep(sk), &wait,
TASK_INTERRUPTIBLE);
release_sock(sk);
timeo = schedule_timeout(timeo);
lock_sock(sk);
finish_wait(sk_sleep(sk), &wait);
}
if ((1 << sk->sk_state) & (TCPF_SYN_RECV|TCPF_ESTABLISHED))
err = 0;
else if (sk->sk_state == TCP_CLOSE_WAIT)
err = -ECONNRESET;
else
err = -ECONNREFUSED;
sock->state = err ? SS_UNCONNECTED : SS_CONNECTED;
out:
release_sock(sk);
return err;
}
int dccp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
size_t len, int nonblock, int flags, int *addr_len)
{
const struct dccp_hdr *dh;
long timeo;
lock_sock(sk);
if (sk->sk_state == DCCP_LISTEN) {
len = -ENOTCONN;
goto out;
}
timeo = sock_rcvtimeo(sk, nonblock);
do {
struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
if (skb == NULL)
goto verify_sock_status;
dh = dccp_hdr(skb);
switch (dh->dccph_type) {
case DCCP_PKT_DATA:
case DCCP_PKT_DATAACK:
goto found_ok_skb;
case DCCP_PKT_CLOSE:
case DCCP_PKT_CLOSEREQ:
if (!(flags & MSG_PEEK))
dccp_finish_passive_close(sk);
/* fall through */
case DCCP_PKT_RESET:
dccp_pr_debug("found fin (%s) ok!\n",
dccp_packet_name(dh->dccph_type));
len = 0;
goto found_fin_ok;
default:
dccp_pr_debug("packet_type=%s\n",
dccp_packet_name(dh->dccph_type));
sk_eat_skb(sk, skb, false);
}
verify_sock_status:
if (sock_flag(sk, SOCK_DONE)) {
len = 0;
break;
}
if (sk->sk_err) {
len = sock_error(sk);
break;
}
if (sk->sk_shutdown & RCV_SHUTDOWN) {
len = 0;
break;
}
if (sk->sk_state == DCCP_CLOSED) {
if (!sock_flag(sk, SOCK_DONE)) {
/* This occurs when user tries to read
* from never connected socket.
*/
len = -ENOTCONN;
break;
}
len = 0;
break;
}
if (!timeo) {
len = -EAGAIN;
break;
}
if (signal_pending(current)) {
len = sock_intr_errno(timeo);
break;
}
sk_wait_data(sk, &timeo);
continue;
found_ok_skb:
if (len > skb->len)
len = skb->len;
else if (len < skb->len)
msg->msg_flags |= MSG_TRUNC;
if (skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len)) {
/* Exception. Bailout! */
len = -EFAULT;
break;
}
if (flags & MSG_TRUNC)
len = skb->len;
found_fin_ok:
if (!(flags & MSG_PEEK))
sk_eat_skb(sk, skb, false);
break;
} while (1);
out:
release_sock(sk);
return len;
}
/*
* receive a message from an RxRPC socket
* - we need to be careful about two or more threads calling recvmsg
* simultaneously
*/
int rxrpc_recvmsg(struct kiocb *iocb, struct socket *sock,
struct msghdr *msg, size_t len, int flags)
{
struct rxrpc_skb_priv *sp;
struct rxrpc_call *call = NULL, *continue_call = NULL;
struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
struct sk_buff *skb;
long timeo;
int copy, ret, ullen, offset, copied = 0;
u32 abort_code;
DEFINE_WAIT(wait);
_enter(",,,%zu,%d", len, flags);
if (flags & (MSG_OOB | MSG_TRUNC))
return -EOPNOTSUPP;
ullen = msg->msg_flags & MSG_CMSG_COMPAT ? 4 : sizeof(unsigned long);
timeo = sock_rcvtimeo(&rx->sk, flags & MSG_DONTWAIT);
msg->msg_flags |= MSG_MORE;
lock_sock(&rx->sk);
for (;;) {
/* return immediately if a client socket has no outstanding
* calls */
if (RB_EMPTY_ROOT(&rx->calls)) {
if (copied)
goto out;
if (rx->sk.sk_state != RXRPC_SERVER_LISTENING) {
release_sock(&rx->sk);
if (continue_call)
rxrpc_put_call(continue_call);
return -ENODATA;
}
}
/* get the next message on the Rx queue */
skb = skb_peek(&rx->sk.sk_receive_queue);
if (!skb) {
/* nothing remains on the queue */
if (copied &&
(msg->msg_flags & MSG_PEEK || timeo == 0))
goto out;
/* wait for a message to turn up */
release_sock(&rx->sk);
prepare_to_wait_exclusive(sk_sleep(&rx->sk), &wait,
TASK_INTERRUPTIBLE);
ret = sock_error(&rx->sk);
if (ret)
goto wait_error;
if (skb_queue_empty(&rx->sk.sk_receive_queue)) {
if (signal_pending(current))
goto wait_interrupted;
timeo = schedule_timeout(timeo);
}
finish_wait(sk_sleep(&rx->sk), &wait);
lock_sock(&rx->sk);
continue;
}
peek_next_packet:
sp = rxrpc_skb(skb);
call = sp->call;
ASSERT(call != NULL);
_debug("next pkt %s", rxrpc_pkts[sp->hdr.type]);
/* make sure we wait for the state to be updated in this call */
spin_lock_bh(&call->lock);
spin_unlock_bh(&call->lock);
if (test_bit(RXRPC_CALL_RELEASED, &call->flags)) {
_debug("packet from released call");
if (skb_dequeue(&rx->sk.sk_receive_queue) != skb)
BUG();
rxrpc_free_skb(skb);
continue;
}
/* determine whether to continue last data receive */
if (continue_call) {
_debug("maybe cont");
if (call != continue_call ||
skb->mark != RXRPC_SKB_MARK_DATA) {
release_sock(&rx->sk);
rxrpc_put_call(continue_call);
_leave(" = %d [noncont]", copied);
return copied;
}
}
rxrpc_get_call(call);
/* copy the peer address and timestamp */
if (!continue_call) {
if (msg->msg_name) {
size_t len =
sizeof(call->conn->trans->peer->srx);
memcpy(msg->msg_name,
&call->conn->trans->peer->srx, len);
msg->msg_namelen = len;
}
sock_recv_ts_and_drops(msg, &rx->sk, skb);
}
/* receive the message */
if (skb->mark != RXRPC_SKB_MARK_DATA)
goto receive_non_data_message;
_debug("recvmsg DATA #%u { %d, %d }",
ntohl(sp->hdr.seq), skb->len, sp->offset);
if (!continue_call) {
/* only set the control data once per recvmsg() */
ret = put_cmsg(msg, SOL_RXRPC, RXRPC_USER_CALL_ID,
ullen, &call->user_call_ID);
if (ret < 0)
goto copy_error;
ASSERT(test_bit(RXRPC_CALL_HAS_USERID, &call->flags));
}
ASSERTCMP(ntohl(sp->hdr.seq), >=, call->rx_data_recv);
ASSERTCMP(ntohl(sp->hdr.seq), <=, call->rx_data_recv + 1);
call->rx_data_recv = ntohl(sp->hdr.seq);
ASSERTCMP(ntohl(sp->hdr.seq), >, call->rx_data_eaten);
offset = sp->offset;
copy = skb->len - offset;
if (copy > len - copied)
copy = len - copied;
ret = skb_copy_datagram_iovec(skb, offset, msg->msg_iov, copy);
if (ret < 0)
goto copy_error;
/* handle piecemeal consumption of data packets */
_debug("copied %d+%d", copy, copied);
offset += copy;
copied += copy;
if (!(flags & MSG_PEEK))
sp->offset = offset;
if (sp->offset < skb->len) {
_debug("buffer full");
ASSERTCMP(copied, ==, len);
break;
}
/* we transferred the whole data packet */
if (sp->hdr.flags & RXRPC_LAST_PACKET) {
_debug("last");
if (call->conn->out_clientflag) {
/* last byte of reply received */
ret = copied;
goto terminal_message;
}
/* last bit of request received */
if (!(flags & MSG_PEEK)) {
_debug("eat packet");
if (skb_dequeue(&rx->sk.sk_receive_queue) !=
skb)
BUG();
rxrpc_free_skb(skb);
}
msg->msg_flags &= ~MSG_MORE;
break;
}
/* move on to the next data message */
_debug("next");
if (!continue_call)
continue_call = sp->call;
else
rxrpc_put_call(call);
call = NULL;
if (flags & MSG_PEEK) {
_debug("peek next");
skb = skb->next;
if (skb == (struct sk_buff *) &rx->sk.sk_receive_queue)
break;
goto peek_next_packet;
}
_debug("eat packet");
if (skb_dequeue(&rx->sk.sk_receive_queue) != skb)
BUG();
rxrpc_free_skb(skb);
}
static int recv_msg(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;
u32 err;
int res;
/* Catch invalid receive requests */
if (unlikely(!buf_len))
return -EINVAL;
lock_sock(sk);
if (unlikely(sock->state == SS_UNCONNECTED)) {
res = -ENOTCONN;
goto exit;
}
/* will be updated in set_orig_addr() if needed */
m->msg_namelen = 0;
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);
/* Complete connection setup for an implied connect */
if (unlikely(sock->state == SS_CONNECTING)) {
res = auto_connect(sock, msg);
if (res)
goto exit;
}
/* Discard an empty non-errored message & try again */
if ((!sz) && (!err)) {
advance_rx_queue(sk);
goto restart;
}
/* Capture sender's address (optional) */
set_orig_addr(m, msg);
/* Capture ancillary data (optional) */
res = anc_data_recv(m, msg, tport);
if (res)
goto exit;
/* Capture message data (if valid) & compute return value (always) */
if (!err) {
if (unlikely(buf_len < sz)) {
sz = buf_len;
m->msg_flags |= MSG_TRUNC;
}
res = skb_copy_datagram_iovec(buf, msg_hdr_sz(msg),
m->msg_iov, sz);
if (res)
goto exit;
res = sz;
} else {
if ((sock->state == SS_READY) ||
((err == TIPC_CONN_SHUTDOWN) || m->msg_control))
res = 0;
else
res = -ECONNRESET;
}
/* Consume received message (optional) */
if (likely(!(flags & MSG_PEEK))) {
if ((sock->state != SS_READY) &&
(++tport->conn_unacked >= TIPC_FLOW_CONTROL_WIN))
tipc_acknowledge(tport->ref, tport->conn_unacked);
advance_rx_queue(sk);
}
exit:
release_sock(sk);
return res;
}
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;
}
/*
* Receive a message from an RxRPC socket
* - we need to be careful about two or more threads calling recvmsg
* simultaneously
*/
int rxrpc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
int flags)
{
struct rxrpc_call *call;
struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
struct list_head *l;
size_t copied = 0;
long timeo;
int ret;
DEFINE_WAIT(wait);
trace_rxrpc_recvmsg(NULL, rxrpc_recvmsg_enter, 0, 0, 0, 0);
if (flags & (MSG_OOB | MSG_TRUNC))
return -EOPNOTSUPP;
timeo = sock_rcvtimeo(&rx->sk, flags & MSG_DONTWAIT);
try_again:
lock_sock(&rx->sk);
/* Return immediately if a client socket has no outstanding calls */
if (RB_EMPTY_ROOT(&rx->calls) &&
list_empty(&rx->recvmsg_q) &&
rx->sk.sk_state != RXRPC_SERVER_LISTENING) {
release_sock(&rx->sk);
return -ENODATA;
}
if (list_empty(&rx->recvmsg_q)) {
ret = -EWOULDBLOCK;
if (timeo == 0) {
call = NULL;
goto error_no_call;
}
release_sock(&rx->sk);
/* Wait for something to happen */
prepare_to_wait_exclusive(sk_sleep(&rx->sk), &wait,
TASK_INTERRUPTIBLE);
ret = sock_error(&rx->sk);
if (ret)
goto wait_error;
if (list_empty(&rx->recvmsg_q)) {
if (signal_pending(current))
goto wait_interrupted;
trace_rxrpc_recvmsg(NULL, rxrpc_recvmsg_wait,
0, 0, 0, 0);
timeo = schedule_timeout(timeo);
}
finish_wait(sk_sleep(&rx->sk), &wait);
goto try_again;
}
/* Find the next call and dequeue it if we're not just peeking. If we
* do dequeue it, that comes with a ref that we will need to release.
*/
write_lock_bh(&rx->recvmsg_lock);
l = rx->recvmsg_q.next;
call = list_entry(l, struct rxrpc_call, recvmsg_link);
if (!(flags & MSG_PEEK))
list_del_init(&call->recvmsg_link);
else
rxrpc_get_call(call, rxrpc_call_got);
write_unlock_bh(&rx->recvmsg_lock);
trace_rxrpc_recvmsg(call, rxrpc_recvmsg_dequeue, 0, 0, 0, 0);
if (test_bit(RXRPC_CALL_RELEASED, &call->flags))
BUG();
if (test_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
if (flags & MSG_CMSG_COMPAT) {
unsigned int id32 = call->user_call_ID;
ret = put_cmsg(msg, SOL_RXRPC, RXRPC_USER_CALL_ID,
sizeof(unsigned int), &id32);
} else {
ret = put_cmsg(msg, SOL_RXRPC, RXRPC_USER_CALL_ID,
sizeof(unsigned long),
&call->user_call_ID);
}
if (ret < 0)
goto error;
}
if (msg->msg_name) {
size_t len = sizeof(call->conn->params.peer->srx);
memcpy(msg->msg_name, &call->conn->params.peer->srx, len);
msg->msg_namelen = len;
}
switch (call->state) {
case RXRPC_CALL_SERVER_ACCEPTING:
ret = rxrpc_recvmsg_new_call(rx, call, msg, flags);
break;
case RXRPC_CALL_CLIENT_RECV_REPLY:
case RXRPC_CALL_SERVER_RECV_REQUEST:
case RXRPC_CALL_SERVER_ACK_REQUEST:
ret = rxrpc_recvmsg_data(sock, call, msg, &msg->msg_iter, len,
flags, &copied);
if (ret == -EAGAIN)
ret = 0;
if (after(call->rx_top, call->rx_hard_ack) &&
call->rxtx_buffer[(call->rx_hard_ack + 1) & RXRPC_RXTX_BUFF_MASK])
rxrpc_notify_socket(call);
break;
default:
ret = 0;
break;
}
if (ret < 0)
goto error;
if (call->state == RXRPC_CALL_COMPLETE) {
ret = rxrpc_recvmsg_term(call, msg);
if (ret < 0)
goto error;
if (!(flags & MSG_PEEK))
rxrpc_release_call(rx, call);
msg->msg_flags |= MSG_EOR;
ret = 1;
}
if (ret == 0)
msg->msg_flags |= MSG_MORE;
else
msg->msg_flags &= ~MSG_MORE;
ret = copied;
error:
rxrpc_put_call(call, rxrpc_call_put);
error_no_call:
release_sock(&rx->sk);
trace_rxrpc_recvmsg(call, rxrpc_recvmsg_return, 0, 0, 0, ret);
return ret;
wait_interrupted:
ret = sock_intr_errno(timeo);
wait_error:
finish_wait(sk_sleep(&rx->sk), &wait);
call = NULL;
goto error_no_call;
}
int rxrpc_recvmsg(struct kiocb *iocb, struct socket *sock,
struct msghdr *msg, size_t len, int flags)
{
struct rxrpc_skb_priv *sp;
struct rxrpc_call *call = NULL, *continue_call = NULL;
struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
struct sk_buff *skb;
long timeo;
int copy, ret, ullen, offset, copied = 0;
u32 abort_code;
DEFINE_WAIT(wait);
_enter(",,,%zu,%d", len, flags);
if (flags & (MSG_OOB | MSG_TRUNC))
return -EOPNOTSUPP;
ullen = msg->msg_flags & MSG_CMSG_COMPAT ? 4 : sizeof(unsigned long);
timeo = sock_rcvtimeo(&rx->sk, flags & MSG_DONTWAIT);
msg->msg_flags |= MSG_MORE;
lock_sock(&rx->sk);
for (;;) {
if (RB_EMPTY_ROOT(&rx->calls)) {
if (copied)
goto out;
if (rx->sk.sk_state != RXRPC_SERVER_LISTENING) {
release_sock(&rx->sk);
if (continue_call)
rxrpc_put_call(continue_call);
return -ENODATA;
}
}
skb = skb_peek(&rx->sk.sk_receive_queue);
if (!skb) {
if (copied &&
(msg->msg_flags & MSG_PEEK || timeo == 0))
goto out;
release_sock(&rx->sk);
prepare_to_wait_exclusive(sk_sleep(&rx->sk), &wait,
TASK_INTERRUPTIBLE);
ret = sock_error(&rx->sk);
if (ret)
goto wait_error;
if (skb_queue_empty(&rx->sk.sk_receive_queue)) {
if (signal_pending(current))
goto wait_interrupted;
timeo = schedule_timeout(timeo);
}
finish_wait(sk_sleep(&rx->sk), &wait);
lock_sock(&rx->sk);
continue;
}
peek_next_packet:
sp = rxrpc_skb(skb);
call = sp->call;
ASSERT(call != NULL);
_debug("next pkt %s", rxrpc_pkts[sp->hdr.type]);
spin_lock_bh(&call->lock);
spin_unlock_bh(&call->lock);
if (test_bit(RXRPC_CALL_RELEASED, &call->flags)) {
_debug("packet from released call");
if (skb_dequeue(&rx->sk.sk_receive_queue) != skb)
BUG();
rxrpc_free_skb(skb);
continue;
}
if (continue_call) {
_debug("maybe cont");
if (call != continue_call ||
skb->mark != RXRPC_SKB_MARK_DATA) {
release_sock(&rx->sk);
rxrpc_put_call(continue_call);
_leave(" = %d [noncont]", copied);
return copied;
}
}
rxrpc_get_call(call);
if (!continue_call) {
if (msg->msg_name && msg->msg_namelen > 0)
memcpy(msg->msg_name,
&call->conn->trans->peer->srx,
sizeof(call->conn->trans->peer->srx));
sock_recv_ts_and_drops(msg, &rx->sk, skb);
}
if (skb->mark != RXRPC_SKB_MARK_DATA)
goto receive_non_data_message;
_debug("recvmsg DATA #%u { %d, %d }",
ntohl(sp->hdr.seq), skb->len, sp->offset);
if (!continue_call) {
ret = put_cmsg(msg, SOL_RXRPC, RXRPC_USER_CALL_ID,
ullen, &call->user_call_ID);
if (ret < 0)
goto copy_error;
ASSERT(test_bit(RXRPC_CALL_HAS_USERID, &call->flags));
}
ASSERTCMP(ntohl(sp->hdr.seq), >=, call->rx_data_recv);
ASSERTCMP(ntohl(sp->hdr.seq), <=, call->rx_data_recv + 1);
call->rx_data_recv = ntohl(sp->hdr.seq);
ASSERTCMP(ntohl(sp->hdr.seq), >, call->rx_data_eaten);
offset = sp->offset;
copy = skb->len - offset;
if (copy > len - copied)
copy = len - copied;
if (skb->ip_summed == CHECKSUM_UNNECESSARY) {
ret = skb_copy_datagram_iovec(skb, offset,
msg->msg_iov, copy);
} else {
ret = skb_copy_and_csum_datagram_iovec(skb, offset,
msg->msg_iov);
if (ret == -EINVAL)
goto csum_copy_error;
}
if (ret < 0)
goto copy_error;
_debug("copied %d+%d", copy, copied);
offset += copy;
copied += copy;
if (!(flags & MSG_PEEK))
sp->offset = offset;
if (sp->offset < skb->len) {
_debug("buffer full");
ASSERTCMP(copied, ==, len);
break;
}
if (sp->hdr.flags & RXRPC_LAST_PACKET) {
_debug("last");
if (call->conn->out_clientflag) {
ret = copied;
goto terminal_message;
}
if (!(flags & MSG_PEEK)) {
_debug("eat packet");
if (skb_dequeue(&rx->sk.sk_receive_queue) !=
skb)
BUG();
rxrpc_free_skb(skb);
}
msg->msg_flags &= ~MSG_MORE;
break;
}
_debug("next");
if (!continue_call)
continue_call = sp->call;
else
rxrpc_put_call(call);
call = NULL;
if (flags & MSG_PEEK) {
_debug("peek next");
skb = skb->next;
if (skb == (struct sk_buff *) &rx->sk.sk_receive_queue)
break;
goto peek_next_packet;
}
_debug("eat packet");
if (skb_dequeue(&rx->sk.sk_receive_queue) != skb)
BUG();
rxrpc_free_skb(skb);
}