af_x25.c

Linux Kernel 2.6.9 for OMAP1710

	if (sock->type != SOCK_SEQPACKET || protocol)
		goto out;

	rc = -ENOMEM;
	if ((sk = x25_alloc_socket()) == NULL)
		goto out;

	x25 = x25_sk(sk);

	sock_init_data(sock, sk);
	sk_set_owner(sk, THIS_MODULE);

	x25_init_timers(sk);

	sock->ops    = &x25_proto_ops;
	sk->sk_protocol = protocol;
	sk->sk_backlog_rcv = x25_backlog_rcv;

	x25->t21   = sysctl_x25_call_request_timeout;
	x25->t22   = sysctl_x25_reset_request_timeout;
	x25->t23   = sysctl_x25_clear_request_timeout;
	x25->t2    = sysctl_x25_ack_holdback_timeout;
	x25->state = X25_STATE_0;

	x25->facilities.winsize_in  = X25_DEFAULT_WINDOW_SIZE;
	x25->facilities.winsize_out = X25_DEFAULT_WINDOW_SIZE;
	x25->facilities.pacsize_in  = X25_DEFAULT_PACKET_SIZE;
	x25->facilities.pacsize_out = X25_DEFAULT_PACKET_SIZE;
	x25->facilities.throughput  = X25_DEFAULT_THROUGHPUT;
	x25->facilities.reverse     = X25_DEFAULT_REVERSE;
	rc = 0;
out:
	return rc;
}

static struct sock *x25_make_new(struct sock *osk)
{
	struct sock *sk = NULL;
	struct x25_opt *x25, *ox25;

	if (osk->sk_type != SOCK_SEQPACKET)
		goto out;

	if ((sk = x25_alloc_socket()) == NULL)
		goto out;

	x25 = x25_sk(sk);

	sk->sk_type        = osk->sk_type;
	sk->sk_socket      = osk->sk_socket;
	sk->sk_priority    = osk->sk_priority;
	sk->sk_protocol    = osk->sk_protocol;
	sk->sk_rcvbuf      = osk->sk_rcvbuf;
	sk->sk_sndbuf      = osk->sk_sndbuf;
	sk->sk_debug       = osk->sk_debug;
	sk->sk_state       = TCP_ESTABLISHED;
	sk->sk_sleep       = osk->sk_sleep;
	sk->sk_zapped      = osk->sk_zapped;
	sk->sk_backlog_rcv = osk->sk_backlog_rcv;

	ox25 = x25_sk(osk);
	x25->t21        = ox25->t21;
	x25->t22        = ox25->t22;
	x25->t23        = ox25->t23;
	x25->t2         = ox25->t2;
	x25->facilities = ox25->facilities;
	x25->qbitincl   = ox25->qbitincl;

	x25_init_timers(sk);
out:
	return sk;
}

static int x25_release(struct socket *sock)
{
	struct sock *sk = sock->sk;
	struct x25_opt *x25;

	if (!sk)
		goto out;

	x25 = x25_sk(sk);

	switch (x25->state) {

		case X25_STATE_0:
		case X25_STATE_2:
			x25_disconnect(sk, 0, 0, 0);
			x25_destroy_socket(sk);
			goto out;

		case X25_STATE_1:
		case X25_STATE_3:
		case X25_STATE_4:
			x25_clear_queues(sk);
			x25_write_internal(sk, X25_CLEAR_REQUEST);
			x25_start_t23timer(sk);
			x25->state = X25_STATE_2;
			sk->sk_state	= TCP_CLOSE;
			sk->sk_shutdown	|= SEND_SHUTDOWN;
			sk->sk_state_change(sk);
			sock_set_flag(sk, SOCK_DEAD);
			sock_set_flag(sk, SOCK_DESTROY);
			break;
	}

	sock->sk	= NULL;	
	sk->sk_socket	= NULL;	/* Not used, but we should do this */
out:
	return 0;
}

static int x25_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
{
	struct sock *sk = sock->sk;
	struct sockaddr_x25 *addr = (struct sockaddr_x25 *)uaddr;

	if (!sk->sk_zapped ||
	    addr_len != sizeof(struct sockaddr_x25) ||
	    addr->sx25_family != AF_X25)
		return -EINVAL;

	x25_sk(sk)->source_addr = addr->sx25_addr;
	x25_insert_socket(sk);
	sk->sk_zapped = 0;
	SOCK_DEBUG(sk, "x25_bind: socket is bound\n");

	return 0;
}

static int x25_wait_for_connection_establishment(struct sock *sk)
{
	DECLARE_WAITQUEUE(wait, current);
        int rc;

	add_wait_queue_exclusive(sk->sk_sleep, &wait);
	for (;;) {
		__set_current_state(TASK_INTERRUPTIBLE);
		rc = -ERESTARTSYS;
		if (signal_pending(current))
			break;
		rc = sock_error(sk);
		if (rc) {
			sk->sk_socket->state = SS_UNCONNECTED;
			break;
		}
		rc = 0;
		if (sk->sk_state != TCP_ESTABLISHED) {
			release_sock(sk);
			schedule();
			lock_sock(sk);
		} else
			break;
	}
	__set_current_state(TASK_RUNNING);
	remove_wait_queue(sk->sk_sleep, &wait);
	return rc;
}

static int x25_connect(struct socket *sock, struct sockaddr *uaddr,
		       int addr_len, int flags)
{
	struct sock *sk = sock->sk;
	struct x25_opt *x25 = x25_sk(sk);
	struct sockaddr_x25 *addr = (struct sockaddr_x25 *)uaddr;
	struct x25_route *rt;
	int rc = 0;

	lock_sock(sk);
	if (sk->sk_state == TCP_ESTABLISHED && sock->state == SS_CONNECTING) {
		sock->state = SS_CONNECTED;
		goto out; /* Connect completed during a ERESTARTSYS event */
	}

	rc = -ECONNREFUSED;
	if (sk->sk_state == TCP_CLOSE && sock->state == SS_CONNECTING) {
		sock->state = SS_UNCONNECTED;
		goto out;
	}

	rc = -EISCONN;	/* No reconnect on a seqpacket socket */
	if (sk->sk_state == TCP_ESTABLISHED)
		goto out;

	sk->sk_state   = TCP_CLOSE;	
	sock->state = SS_UNCONNECTED;

	rc = -EINVAL;
	if (addr_len != sizeof(struct sockaddr_x25) ||
	    addr->sx25_family != AF_X25)
		goto out;

	rc = -ENETUNREACH;
	rt = x25_get_route(&addr->sx25_addr);
	if (!rt)
		goto out;

	x25->neighbour = x25_get_neigh(rt->dev);
	if (!x25->neighbour)
		goto out_put_route;

	x25_limit_facilities(&x25->facilities, x25->neighbour);

	x25->lci = x25_new_lci(x25->neighbour);
	if (!x25->lci)
		goto out_put_neigh;

	rc = -EINVAL;
	if (sk->sk_zapped) /* Must bind first - autobinding does not work */
		goto out_put_neigh;

	if (!strcmp(x25->source_addr.x25_addr, null_x25_address.x25_addr))
		memset(&x25->source_addr, '\0', X25_ADDR_LEN);

	x25->dest_addr = addr->sx25_addr;

	/* Move to connecting socket, start sending Connect Requests */
	sock->state   = SS_CONNECTING;
	sk->sk_state  = TCP_SYN_SENT;

	x25->state = X25_STATE_1;

	x25_write_internal(sk, X25_CALL_REQUEST);

	x25_start_heartbeat(sk);
	x25_start_t21timer(sk);

	/* Now the loop */
	rc = -EINPROGRESS;
	if (sk->sk_state != TCP_ESTABLISHED && (flags & O_NONBLOCK))
		goto out_put_neigh;

	rc = x25_wait_for_connection_establishment(sk);
	if (rc)
		goto out_put_neigh;

	sock->state = SS_CONNECTED;
	rc = 0;
out_put_neigh:
	if (rc)
		x25_neigh_put(x25->neighbour);
out_put_route:
	x25_route_put(rt);
out:
	release_sock(sk);
	return rc;
}

static int x25_wait_for_data(struct sock *sk, int timeout)
{
	DECLARE_WAITQUEUE(wait, current);
	int rc = 0;

	add_wait_queue_exclusive(sk->sk_sleep, &wait);
	for (;;) {
		__set_current_state(TASK_INTERRUPTIBLE);
		if (sk->sk_shutdown & RCV_SHUTDOWN)
			break;
		rc = -ERESTARTSYS;
		if (signal_pending(current))
			break;
		rc = -EAGAIN;
		if (!timeout)
			break;
		rc = 0;
		if (skb_queue_empty(&sk->sk_receive_queue)) {
			release_sock(sk);
			timeout = schedule_timeout(timeout);
			lock_sock(sk);
		} else
			break;
	}
	__set_current_state(TASK_RUNNING);
	remove_wait_queue(sk->sk_sleep, &wait);
	return rc;
}
	
static int x25_accept(struct socket *sock, struct socket *newsock, int flags)
{
	struct sock *sk = sock->sk;
	struct sock *newsk;
	struct sk_buff *skb;
	int rc = -EINVAL;

	if (!sk || sk->sk_state != TCP_LISTEN)
		goto out;

	rc = -EOPNOTSUPP;
	if (sk->sk_type != SOCK_SEQPACKET)
		goto out;

	lock_sock(sk);
	rc = x25_wait_for_data(sk, sk->sk_rcvtimeo);
	if (rc)
		goto out2;
	skb = skb_dequeue(&sk->sk_receive_queue);
	rc = -EINVAL;
	if (!skb->sk)
		goto out2;
	newsk		 = skb->sk;
	newsk->sk_socket = newsock;
	newsk->sk_sleep  = &newsock->wait;

	/* Now attach up the new socket */
	skb->sk = NULL;
	kfree_skb(skb);
	sk->sk_ack_backlog--;
	newsock->sk    = newsk;
	newsock->state = SS_CONNECTED;
	rc = 0;
out2:
	release_sock(sk);
out:
	return rc;
}

static int x25_getname(struct socket *sock, struct sockaddr *uaddr,
		       int *uaddr_len, int peer)
{
	struct sockaddr_x25 *sx25 = (struct sockaddr_x25 *)uaddr;
	struct sock *sk = sock->sk;
	struct x25_opt *x25 = x25_sk(sk);

	if (peer) {
		if (sk->sk_state != TCP_ESTABLISHED)
			return -ENOTCONN;
		sx25->sx25_addr = x25->dest_addr;
	} else
		sx25->sx25_addr = x25->source_addr;

	sx25->sx25_family = AF_X25;
	*uaddr_len = sizeof(*sx25);

	return 0;
}
 
int x25_rx_call_request(struct sk_buff *skb, struct x25_neigh *nb,
			unsigned int lci)
{
	struct sock *sk;
	struct sock *make;
	struct x25_opt *makex25;
	struct x25_address source_addr, dest_addr;
	struct x25_facilities facilities;
	int len, rc;

	/*
	 *	Remove the LCI and frame type.
	 */
	skb_pull(skb, X25_STD_MIN_LEN);

	/*
	 *	Extract the X.25 addresses and convert them to ASCII strings,
	 *	and remove them.
	 */
	skb_pull(skb, x25_addr_ntoa(skb->data, &source_addr, &dest_addr));

	/*
	 *	Find a listener for the particular address.
	 */
	sk = x25_find_listener(&source_addr);

	/*
	 *	We can't accept the Call Request.
	 */
	if (!sk || sk->sk_ack_backlog == sk->sk_max_ack_backlog)
		goto out_clear_request;

	/*
	 *	Try to reach a compromise on the requested facilities.
	 */
	if ((len = x25_negotiate_facilities(skb, sk, &facilities)) == -1)
		goto out_sock_put;

	/*
	 * current neighbour/link might impose additional limits
	 * on certain facilties
	 */

	x25_limit_facilities(&facilities, nb);

	/*
	 *	Try to create a new socket.
	 */
	make = x25_make_new(sk);
	if (!make)
		goto out_sock_put;

	/*
	 *	Remove the facilities, leaving any Call User Data.
	 */
	skb_pull(skb, len);

	skb->sk     = make;
	make->sk_state = TCP_ESTABLISHED;

	makex25 = x25_sk(make);
	makex25->lci           = lci;
	makex25->dest_addr     = dest_addr;
	makex25->source_addr   = source_addr;
	makex25->neighbour     = nb;
	makex25->facilities    = facilities;
	makex25->vc_facil_mask = x25_sk(sk)->vc_facil_mask;

	x25_write_internal(make, X25_CALL_ACCEPTED);

	/*
	 *	Incoming Call User Data.
	 */
	if (skb->len >= 0) {
		memcpy(makex25->calluserdata.cuddata, skb->data, skb->len);
		makex25->calluserdata.cudlength = skb->len;
	}

	makex25->state = X25_STATE_3;

	sk->sk_ack_backlog++;

	x25_insert_socket(make);

	skb_queue_head(&sk->sk_receive_queue, skb);

	x25_start_heartbeat(make);

	if (!sock_flag(sk, SOCK_DEAD))
		sk->sk_data_ready(sk, skb->len);
	rc = 1;
	sock_put(sk);
out:
	return rc;
out_sock_put:
	sock_put(sk);
out_clear_request:
	rc = 0;
	x25_transmit_clear_request(nb, lci, 0x01);
	goto out;
}

static int x25_sendmsg(struct kiocb *iocb, struct socket *sock,
		       struct msghdr *msg, size_t len)
{
	struct sock *sk = sock->sk;
	struct x25_opt *x25 = x25_sk(sk);
	struct sockaddr_x25 *usx25 = (struct sockaddr_x25 *)msg->msg_name;
	struct sockaddr_x25 sx25;
	struct sk_buff *skb;
	unsigned char *asmptr;
	int noblock = msg->msg_flags & MSG_DONTWAIT;
	size_t size;
	int qbit = 0, rc = -EINVAL;

	if (msg->msg_flags & ~(MSG_DONTWAIT|MSG_OOB|MSG_EOR|MSG_CMSG_COMPAT))
		goto out;

	/* we currently don't support segmented records at the user interface */
	if (!(msg->msg_flags & (MSG_EOR|MSG_OOB)))
		goto out;

	rc = -EADDRNOTAVAIL;
	if (sk->sk_zapped)
		goto out;

	rc = -EPIPE;
	if (sk->sk_shutdown & SEND_SHUTDOWN) {
		send_sig(SIGPIPE, current, 0);
		goto out;
	}

	rc = -ENETUNREACH;