int accept(int sockfd, struct sockaddr *addr, socklen_t *addrlen)
{
FAR struct socket *psock = sockfd_socket(sockfd);
FAR struct socket *pnewsock;
FAR struct uip_conn *conn;
struct accept_s state;
#ifdef CONFIG_NET_IPv6
FAR struct sockaddr_in6 *inaddr = (struct sockaddr_in6 *)addr;
#else
FAR struct sockaddr_in *inaddr = (struct sockaddr_in *)addr;
#endif
uip_lock_t save;
int newfd;
int err;
int ret;
/* Verify that the sockfd corresponds to valid, allocated socket */
if (!psock || psock->s_crefs <= 0)
{
/* It is not a valid socket description. Distinguish between the cases
* where sockfd is a just valid and when it is a valid file descriptor used
* in the wrong context.
*/
#if CONFIG_NFILE_DESCRIPTORS > 0
if ((unsigned int)sockfd < CONFIG_NFILE_DESCRIPTORS)
{
err = ENOTSOCK;
}
else
#endif
{
err = EBADF;
}
goto errout;
}
/* We have a socket descriptor, but it is a stream? */
if (psock->s_type != SOCK_STREAM)
{
err = EOPNOTSUPP;
goto errout;
}
/* Is the socket listening for a connection? */
if (!_SS_ISLISTENING(psock->s_flags))
{
err = EINVAL;
goto errout;
}
/* Verify that a valid memory block has been provided to receive the
* address
*/
if (addr)
{
#ifdef CONFIG_NET_IPv6
if (*addrlen < sizeof(struct sockaddr_in6))
#else
if (*addrlen < sizeof(struct sockaddr_in))
#endif
{
err = EBADF;
goto errout;
}
}
/* Allocate a socket descriptor for the new connection now (so that it
* cannot fail later)
*/
newfd = sockfd_allocate(0);
if (newfd < 0)
{
err = ENFILE;
goto errout;
}
pnewsock = sockfd_socket(newfd);
if (!pnewsock)
{
err = ENFILE;
goto errout_with_socket;
}
/* Check the backlog to see if there is a connection already pending for
* this listener.
*/
save = uip_lock();
conn = (struct uip_conn *)psock->s_conn;
#ifdef CONFIG_NET_TCPBACKLOG
state.acpt_newconn = uip_backlogremove(conn);
if (state.acpt_newconn)
{
/* Yes... get the address of the connected client */
nvdbg("Pending conn=%p\n", state.acpt_newconn);
accept_tcpsender(state.acpt_newconn, inaddr);
}
/* In general, this uIP-based implementation will not support non-blocking
* socket operations... except in a few cases: Here for TCP accept with backlog
* enabled. If this socket is configured as non-blocking then return EAGAIN
* if there is no pending connection in the backlog.
*/
else if (_SS_ISNONBLOCK(psock->s_flags))
{
err = EAGAIN;
goto errout_with_lock;
}
else
#endif
{
/* Set the socket state to accepting */
psock->s_flags = _SS_SETSTATE(psock->s_flags, _SF_ACCEPT);
/* Perform the TCP accept operation */
/* Initialize the state structure. This is done with interrupts
* disabled because we don't want anything to happen until we
* are ready.
*/
state.acpt_addr = inaddr;
state.acpt_newconn = NULL;
state.acpt_result = OK;
sem_init(&state.acpt_sem, 0, 0);
/* Set up the callback in the connection */
conn->accept_private = (void*)&state;
conn->accept = accept_interrupt;
/* Wait for the send to complete or an error to occur: NOTES: (1)
* uip_lockedwait will also terminate if a signal is received, (2) interrupts
* may be disabled! They will be re-enabled while the task sleeps and
* automatically re-enabled when the task restarts.
*/
ret = uip_lockedwait(&state.acpt_sem);
/* Make sure that no further interrupts are processed */
conn->accept_private = NULL;
conn->accept = NULL;
sem_destroy(&state. acpt_sem);
/* Set the socket state to idle */
psock->s_flags = _SS_SETSTATE(psock->s_flags, _SF_IDLE);
/* Check for a errors. Errors are signaled by negative errno values
* for the send length.
*/
if (state.acpt_result != 0)
{
err = state.acpt_result;
goto errout_with_lock;
}
/* If uip_lockedwait failed, then we were probably reawakened by a signal. In
* this case, uip_lockedwait will have set errno appropriately.
*/
if (ret < 0)
{
err = -ret;
goto errout_with_lock;
}
}
/* Initialize the socket structure and mark the socket as connected.
* (The reference count on the new connection structure was set in the
* interrupt handler).
*/
pnewsock->s_type = SOCK_STREAM;
pnewsock->s_conn = state.acpt_newconn;
pnewsock->s_flags |= _SF_CONNECTED;
pnewsock->s_flags &= ~_SF_CLOSED;
/* Begin monitoring for TCP connection events on the newly connected socket */
net_startmonitor(pnewsock);
uip_unlock(save);
return newfd;
errout_with_lock:
uip_unlock(save);
errout_with_socket:
sockfd_release(newfd);
errout:
errno = err;
return ERROR;
}
int tcp_pollsetup(FAR struct socket *psock, FAR struct pollfd *fds)
{
FAR struct tcp_conn_s *conn = psock->s_conn;
FAR struct tcp_poll_s *info;
FAR struct devif_callback_s *cb;
net_lock_t flags;
int ret;
/* Sanity check */
#ifdef CONFIG_DEBUG
if (!conn || !fds)
{
return -EINVAL;
}
#endif
/* Allocate a container to hold the poll information */
info = (FAR struct tcp_poll_s *)kmm_malloc(sizeof(struct tcp_poll_s));
if (!info)
{
return -ENOMEM;
}
/* Some of the following must be atomic */
flags = net_lock();
/* Allocate a TCP/IP callback structure */
cb = tcp_callback_alloc(conn);
if (!cb)
{
ret = -EBUSY;
goto errout_with_lock;
}
/* Initialize the poll info container */
info->psock = psock;
info->fds = fds;
info->cb = cb;
/* Initialize the callback structure. Save the reference to the info
* structure as callback private data so that it will be available during
* callback processing.
*/
cb->flags = (TCP_NEWDATA | TCP_BACKLOG | TCP_POLL | TCP_CLOSE |
TCP_ABORT | TCP_TIMEDOUT);
cb->priv = (FAR void *)info;
cb->event = tcp_poll_interrupt;
/* Save the reference in the poll info structure as fds private as well
* for use durring poll teardown as well.
*/
fds->priv = (FAR void *)info;
#ifdef CONFIG_NET_TCPBACKLOG
/* Check for read data or backlogged connection availability now */
if (!IOB_QEMPTY(&conn->readahead) || tcp_backlogavailable(conn))
#else
/* Check for read data availability now */
if (!IOB_QEMPTY(&conn->readahead))
#endif
{
/* Normal data may be read without blocking. */
fds->revents |= (POLLRDNORM & fds->events);
}
/* Check for a loss of connection events. We need to be careful here.
* There are four possibilities:
*
* 1) The socket is connected and we are waiting for data availability
* events.
*
* __SS_ISCONNECTED(f) == true
* __SS_ISLISTENING(f) == false
* __SS_ISCLOSED(f) == false
*
* Action: Wait for data availability events
*
* 2) This is a listener socket that was never connected and we are
* waiting for connection events.
*
* __SS_ISCONNECTED(f) == false
* __SS_ISLISTENING(f) == true
* __SS_ISCLOSED(f) == false
*
* Action: Wait for connection events
*
* 3) This socket was previously connected, but the peer has gracefully
* closed the connection.
*
* __SS_ISCONNECTED(f) == false
* __SS_ISLISTENING(f) == false
* __SS_ISCLOSED(f) == true
*
* Action: Return with POLLHUP|POLLERR events
*
* 4) This socket was previously connected, but we lost the connection
* due to some exceptional event.
*
* __SS_ISCONNECTED(f) == false
* __SS_ISLISTENING(f) == false
* __SS_ISCLOSED(f) == false
*
* Action: Return with POLLHUP|POLLERR events
*/
if (!_SS_ISCONNECTED(psock->s_flags) && !_SS_ISLISTENING(psock->s_flags))
{
/* We were previously connected but lost the connection either due
* to a graceful shutdown by the remote peer or because of some
* exceptional event.
*/
fds->revents |= (POLLERR | POLLHUP);
}
/* Check if any requested events are already in effect */
if (fds->revents != 0)
{
/* Yes.. then signal the poll logic */
sem_post(fds->sem);
}
net_unlock(flags);
return OK;
errout_with_lock:
kmm_free(info);
net_unlock(flags);
return ret;
}
