C++ release_sock函数代码示例

static int connect(struct socket *sock, struct sockaddr *dest, int destlen,
		   int flags)
{
	struct sock *sk = sock->sk;
	struct sockaddr_tipc *dst = (struct sockaddr_tipc *)dest;
	struct msghdr m = {NULL,};
	struct sk_buff *buf;
	struct tipc_msg *msg;
	unsigned int timeout;
	int res;

	lock_sock(sk);

	/* For now, TIPC does not allow use of connect() with DGRAM/RDM types */

	if (sock->state == SS_READY) {
		res = -EOPNOTSUPP;
		goto exit;
	}

	/* For now, TIPC does not support the non-blocking form of connect() */

	if (flags & O_NONBLOCK) {
		res = -EOPNOTSUPP;
		goto exit;
	}

	/* Issue Posix-compliant error code if socket is in the wrong state */

	if (sock->state == SS_LISTENING) {
		res = -EOPNOTSUPP;
		goto exit;
	}
	if (sock->state == SS_CONNECTING) {
		res = -EALREADY;
		goto exit;
	}
	if (sock->state != SS_UNCONNECTED) {
		res = -EISCONN;
		goto exit;
	}

	/*
	 * Reject connection attempt using multicast address
	 *
	 * Note: send_msg() validates the rest of the address fields,
	 *       so there's no need to do it here
	 */

	if (dst->addrtype == TIPC_ADDR_MCAST) {
		res = -EINVAL;
		goto exit;
	}

	/* Reject any messages already in receive queue (very unlikely) */

	reject_rx_queue(sk);

	/* Send a 'SYN-' to destination */

	m.msg_name = dest;
	m.msg_namelen = destlen;
	res = send_msg(NULL, sock, &m, 0);
	if (res < 0)
		goto exit;

	/* Wait until an 'ACK' or 'RST' arrives, or a timeout occurs */

	timeout = tipc_sk(sk)->conn_timeout;
	release_sock(sk);
	res = wait_event_interruptible_timeout(*sk_sleep(sk),
			(!skb_queue_empty(&sk->sk_receive_queue) ||
			(sock->state != SS_CONNECTING)),
			timeout ? (long)msecs_to_jiffies(timeout)
				: MAX_SCHEDULE_TIMEOUT);
	lock_sock(sk);

	if (res > 0) {
		buf = skb_peek(&sk->sk_receive_queue);
		if (buf != NULL) {
			msg = buf_msg(buf);
			res = auto_connect(sock, msg);
			if (!res) {
				if (!msg_data_sz(msg))
					advance_rx_queue(sk);
			}
		} else {
			if (sock->state == SS_CONNECTED)
				res = -EISCONN;
			else
				res = -ECONNREFUSED;
		}
	} else {
		if (res == 0)
			res = -ETIMEDOUT;
		else
			; /* leave "res" unchanged */
		sock->state = SS_DISCONNECTING;
	}

//.........这里部分代码省略.........

//.........这里部分代码省略.........
		if (get_user(opt, (u32 __user *) optval)) {
			err = -EFAULT;
			break;
		}

		bt_sk(sk)->defer_setup = opt;
		break;

	case BT_POWER:
		if (sk->sk_type != SOCK_SEQPACKET && sk->sk_type != SOCK_STREAM
				&& sk->sk_type != SOCK_RAW) {
			err = -EINVAL;
			break;
		}

		pwr.force_active = 1;

		len = min_t(unsigned int, sizeof(pwr), optlen);
		if (copy_from_user((char *) &pwr, optval, len)) {
			err = -EFAULT;
			break;
		}
		l2cap_pi(sk)->force_active = pwr.force_active;
		break;

	case BT_AMP_POLICY:
		if (get_user(opt, (u32 __user *) optval)) {
			err = -EFAULT;
			break;
		}

		if ((opt > BT_AMP_POLICY_PREFER_AMP) ||
			((l2cap_pi(sk)->mode != L2CAP_MODE_ERTM) &&
			 (l2cap_pi(sk)->mode != L2CAP_MODE_STREAMING))) {
			err = -EINVAL;
			break;
		}

		l2cap_pi(sk)->amp_pref = (u8) opt;
		BT_DBG("BT_AMP_POLICY now %d", opt);

		if ((sk->sk_state == BT_CONNECTED) &&
			(l2cap_pi(sk)->amp_move_role == L2CAP_AMP_MOVE_NONE))
			l2cap_amp_move_init(sk);

		break;

	case BT_FLUSHABLE:
		if (get_user(opt, (u32 __user *) optval)) {
			err = -EFAULT;
			break;
		}
		l2cap_pi(sk)->flushable = opt;

		break;

	case BT_LE_PARAMS:
		if (l2cap_pi(sk)->scid != L2CAP_CID_LE_DATA) {
			err = -EINVAL;
			break;
		}

		if (copy_from_user((char *) &le_params, optval,
					sizeof(struct bt_le_params))) {
			err = -EFAULT;
			break;
		}

		conn = l2cap_pi(sk)->conn;
		if (!conn || !conn->hcon ||
				l2cap_pi(sk)->scid != L2CAP_CID_LE_DATA) {
			memcpy(&bt_sk(sk)->le_params, &le_params,
							sizeof(le_params));
			break;
		}

		if (!conn->hcon->out ||
				!l2cap_sock_le_conn_update_params_valid(
					&le_params)) {
			err = -EINVAL;
			break;
		}

		memcpy(&bt_sk(sk)->le_params, &le_params, sizeof(le_params));

		hci_le_conn_update(conn->hcon,
				le_params.interval_min,
				le_params.interval_max,
				le_params.latency,
				le_params.supervision_timeout);
		break;

	default:
		err = -ENOPROTOOPT;
		break;
	}

	release_sock(sk);
	return err;
}

static int raw_bind(struct socket *sock, struct sockaddr *uaddr, int len)
{
	struct sockaddr_can *addr = (struct sockaddr_can *)uaddr;
	struct sock *sk = sock->sk;
	struct raw_sock *ro = raw_sk(sk);
	int ifindex;
	int err = 0;
	int notify_enetdown = 0;

	if (len < sizeof(*addr))
		return -EINVAL;

	lock_sock(sk);

	if (ro->bound && addr->can_ifindex == ro->ifindex)
		goto out;

	if (addr->can_ifindex) {
		struct net_device *dev;

		dev = dev_get_by_index(&init_net, addr->can_ifindex);
		if (!dev) {
			err = -ENODEV;
			goto out;
		}
		if (dev->type != ARPHRD_CAN) {
			dev_put(dev);
			err = -ENODEV;
			goto out;
		}
		if (!(dev->flags & IFF_UP))
			notify_enetdown = 1;

		ifindex = dev->ifindex;

		/* filters set by default/setsockopt */
		err = raw_enable_allfilters(dev, sk);
		dev_put(dev);
	} else {
		ifindex = 0;

		/* filters set by default/setsockopt */
		err = raw_enable_allfilters(NULL, sk);
	}

	if (!err) {
		if (ro->bound) {
			/* unregister old filters */
			if (ro->ifindex) {
				struct net_device *dev;

				dev = dev_get_by_index(&init_net, ro->ifindex);
				if (dev) {
					raw_disable_allfilters(dev, sk);
					dev_put(dev);
				}
			} else
				raw_disable_allfilters(NULL, sk);
		}
		ro->ifindex = ifindex;
		ro->bound = 1;
	}

 out:
	release_sock(sk);

	if (notify_enetdown) {
		sk->sk_err = ENETDOWN;
		if (!sock_flag(sk, SOCK_DEAD))
			sk->sk_error_report(sk);
	}

	return err;
}

static int l2cap_sock_connect(struct socket *sock, struct sockaddr *addr, int alen, int flags)
{
	struct sock *sk = sock->sk;
	struct sockaddr_l2 la;
	int len, err = 0;

	BT_DBG("sk %p type %d mode %d state %d", sk, sk->sk_type,
		l2cap_pi(sk)->mode, sk->sk_state);

	if (!addr || alen < sizeof(addr->sa_family) ||
	    addr->sa_family != AF_BLUETOOTH)
		return -EINVAL;

	memset(&la, 0, sizeof(la));
	len = min_t(unsigned int, sizeof(la), alen);
	memcpy(&la, addr, len);

	if (la.l2_cid && la.l2_psm)
		return -EINVAL;

	lock_sock(sk);

	if ((sk->sk_type == SOCK_SEQPACKET || sk->sk_type == SOCK_STREAM)
		&& !(la.l2_psm || la.l2_cid || l2cap_pi(sk)->fixed_channel)) {
		err = -EINVAL;
		goto done;
	}

	switch (l2cap_pi(sk)->mode) {
	case L2CAP_MODE_BASIC:
		break;
	case L2CAP_MODE_ERTM:
	case L2CAP_MODE_STREAMING:
		if (!disable_ertm)
			break;
		/* fall through */
	default:
		err = -ENOTSUPP;
		goto done;
	}

	switch (sk->sk_state) {
	case BT_CONNECT:
	case BT_CONNECT2:
	case BT_CONFIG:
		/* Already connecting */
		goto wait;

	case BT_CONNECTED:
		/* Already connected */
		err = -EISCONN;
		goto done;

	case BT_OPEN:
	case BT_BOUND:
		/* Can connect */
		break;

	default:
		err = -EBADFD;
		goto done;
	}

	/* PSM must be odd and lsb of upper byte must be 0 */
	if ((__le16_to_cpu(la.l2_psm) & 0x0101) != 0x0001 &&
		!l2cap_pi(sk)->fixed_channel &&
				sk->sk_type != SOCK_RAW && !la.l2_cid) {
		BT_DBG("Bad PSM 0x%x", (int)__le16_to_cpu(la.l2_psm));
		err = -EINVAL;
		goto done;
	}

	/* Set destination address and psm */
	bacpy(&bt_sk(sk)->dst, &la.l2_bdaddr);
	l2cap_pi(sk)->psm = la.l2_psm;
	l2cap_pi(sk)->dcid = la.l2_cid;

	err = l2cap_do_connect(sk);
	if (err)
		goto done;

wait:
	err = bt_sock_wait_state(sk, BT_CONNECTED,
			sock_sndtimeo(sk, flags & O_NONBLOCK));
done:
	if (err)
		BT_ERR("failed %d", err);
	release_sock(sk);
	return err;
}

static int l2cap_sock_getsockopt(struct socket *sock, int level, int optname, char __user *optval, int __user *optlen)
{
	struct sock *sk = sock->sk;
	struct bt_security sec;
	struct bt_power pwr;
	int len, err = 0;

	BT_DBG("sk %p", sk);

	if (level == SOL_L2CAP)
		return l2cap_sock_getsockopt_old(sock, optname, optval, optlen);

	if (level != SOL_BLUETOOTH)
		return -ENOPROTOOPT;

	if (get_user(len, optlen))
		return -EFAULT;

	lock_sock(sk);

	switch (optname) {
	case BT_SECURITY:
		if (sk->sk_type != SOCK_SEQPACKET && sk->sk_type != SOCK_STREAM
				&& sk->sk_type != SOCK_RAW) {
			err = -EINVAL;
			break;
		}

		memset(&sec, 0, sizeof(sec));
		sec.level = l2cap_pi(sk)->sec_level;

		if (sk->sk_state == BT_CONNECTED) {
			sec.key_size = l2cap_pi(sk)->conn->hcon->enc_key_size;
			sec.level = l2cap_pi(sk)->conn->hcon->sec_level;
		}

		len = min_t(unsigned int, len, sizeof(sec));
		if (copy_to_user(optval, (char *) &sec, len))
			err = -EFAULT;

		break;

	case BT_DEFER_SETUP:
		if (sk->sk_state != BT_BOUND && sk->sk_state != BT_LISTEN) {
			err = -EINVAL;
			break;
		}

		if (put_user(bt_sk(sk)->defer_setup, (u32 __user *) optval))
			err = -EFAULT;

		break;

	case BT_POWER:
		if (sk->sk_type != SOCK_SEQPACKET && sk->sk_type != SOCK_STREAM
				&& sk->sk_type != SOCK_RAW) {
			err = -EINVAL;
			break;
		}

		pwr.force_active = l2cap_pi(sk)->force_active;

		len = min_t(unsigned int, len, sizeof(pwr));
		if (copy_to_user(optval, (char *) &pwr, len))
			err = -EFAULT;

		break;

	case BT_AMP_POLICY:
		if (put_user(l2cap_pi(sk)->amp_pref, (u32 __user *) optval))
			err = -EFAULT;
		break;

	case BT_LE_PARAMS:
		if (l2cap_pi(sk)->scid != L2CAP_CID_LE_DATA) {
			err = -EINVAL;
			break;
		}

		if (copy_to_user(optval, (char *) &bt_sk(sk)->le_params,
						sizeof(bt_sk(sk)->le_params)))
			err = -EFAULT;
		break;

	default:
		err = -ENOPROTOOPT;
		break;
	}

	release_sock(sk);
	return err;
}

void dccp_close(struct sock *sk, long timeout)
{
	struct dccp_sock *dp = dccp_sk(sk);
	struct sk_buff *skb;
	u32 data_was_unread = 0;
	int state;

	lock_sock(sk);

	sk->sk_shutdown = SHUTDOWN_MASK;

	if (sk->sk_state == DCCP_LISTEN) {
		dccp_set_state(sk, DCCP_CLOSED);

		/* Special case. */
		inet_csk_listen_stop(sk);

		goto adjudge_to_death;
	}

	sk_stop_timer(sk, &dp->dccps_xmit_timer);

	/*
	 * We need to flush the recv. buffs.  We do this only on the
	 * descriptor close, not protocol-sourced closes, because the
	  *reader process may not have drained the data yet!
	 */
	while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) {
		data_was_unread += skb->len;
		__kfree_skb(skb);
	}

	if (data_was_unread) {
		/* Unread data was tossed, send an appropriate Reset Code */
		DCCP_WARN("DCCP: ABORT -- %u bytes unread\n", data_was_unread);
		dccp_send_reset(sk, DCCP_RESET_CODE_ABORTED);
		dccp_set_state(sk, DCCP_CLOSED);
	} else if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
		/* Check zero linger _after_ checking for unread data. */
		sk->sk_prot->disconnect(sk, 0);
	} else if (sk->sk_state != DCCP_CLOSED) {
		dccp_terminate_connection(sk);
	}

	sk_stream_wait_close(sk, timeout);

adjudge_to_death:
	state = sk->sk_state;
	sock_hold(sk);
	sock_orphan(sk);

	/*
	 * It is the last release_sock in its life. It will remove backlog.
	 */
	release_sock(sk);
	/*
	 * Now socket is owned by kernel and we acquire BH lock
	 * to finish close. No need to check for user refs.
	 */
	local_bh_disable();
	bh_lock_sock(sk);
	WARN_ON(sock_owned_by_user(sk));

	percpu_counter_inc(sk->sk_prot->orphan_count);

	/* Have we already been destroyed by a softirq or backlog? */
	if (state != DCCP_CLOSED && sk->sk_state == DCCP_CLOSED)
		goto out;

	if (sk->sk_state == DCCP_CLOSED)
		inet_csk_destroy_sock(sk);

	/* Otherwise, socket is reprieved until protocol close. */

out:
	bh_unlock_sock(sk);
	local_bh_enable();
	sock_put(sk);
}

static int raw_getsockopt(struct socket *sock, int level, int optname,
			  char __user *optval, int __user *optlen)
{
	struct sock *sk = sock->sk;
	struct raw_sock *ro = raw_sk(sk);
	int len;
	void *val;
	int err = 0;

	if (level != SOL_CAN_RAW)
		return -EINVAL;
	if (get_user(len, optlen))
		return -EFAULT;
	if (len < 0)
		return -EINVAL;

	switch (optname) {

	case CAN_RAW_FILTER:
		lock_sock(sk);
		if (ro->count > 0) {
			int fsize = ro->count * sizeof(struct can_filter);
			if (len > fsize)
				len = fsize;
			if (copy_to_user(optval, ro->filter, len))
				err = -EFAULT;
		} else
			len = 0;
		release_sock(sk);

		if (!err)
			err = put_user(len, optlen);
		return err;

	case CAN_RAW_ERR_FILTER:
		if (len > sizeof(can_err_mask_t))
			len = sizeof(can_err_mask_t);
		val = &ro->err_mask;
		break;

	case CAN_RAW_LOOPBACK:
		if (len > sizeof(int))
			len = sizeof(int);
		val = &ro->loopback;
		break;

	case CAN_RAW_RECV_OWN_MSGS:
		if (len > sizeof(int))
			len = sizeof(int);
		val = &ro->recv_own_msgs;
		break;

	default:
		return -ENOPROTOOPT;
	}

	if (put_user(len, optlen))
		return -EFAULT;
	if (copy_to_user(optval, val, len))
		return -EFAULT;
	return 0;
}

static int send_stream(struct kiocb *iocb, struct socket *sock,
		       struct msghdr *m, size_t total_len)
{
	struct sock *sk = sock->sk;
	struct tipc_port *tport = tipc_sk_port(sk);
	struct msghdr my_msg;
	struct iovec my_iov;
	struct iovec *curr_iov;
	int curr_iovlen;
	char __user *curr_start;
	u32 hdr_size;
	int curr_left;
	int bytes_to_send;
	int bytes_sent;
	int res;

	lock_sock(sk);

	/* Handle special cases where there is no connection */

	if (unlikely(sock->state != SS_CONNECTED)) {
		if (sock->state == SS_UNCONNECTED) {
			res = send_packet(NULL, sock, m, total_len);
			goto exit;
		} else if (sock->state == SS_DISCONNECTING) {
			res = -EPIPE;
			goto exit;
		} else {
			res = -ENOTCONN;
			goto exit;
		}
	}

	if (unlikely(m->msg_name)) {
		res = -EISCONN;
		goto exit;
	}

	if ((total_len > (unsigned)INT_MAX) ||
	    (m->msg_iovlen > (unsigned)INT_MAX)) {
		res = -EMSGSIZE;
		goto exit;
	}

	/*
	 * Send each iovec entry using one or more messages
	 *
	 * Note: This algorithm is good for the most likely case
	 * (i.e. one large iovec entry), but could be improved to pass sets
	 * of small iovec entries into send_packet().
	 */

	curr_iov = m->msg_iov;
	curr_iovlen = m->msg_iovlen;
	my_msg.msg_iov = &my_iov;
	my_msg.msg_iovlen = 1;
	my_msg.msg_flags = m->msg_flags;
	my_msg.msg_name = NULL;
	bytes_sent = 0;

	hdr_size = msg_hdr_sz(&tport->phdr);

	while (curr_iovlen--) {
		curr_start = curr_iov->iov_base;
		curr_left = curr_iov->iov_len;

		while (curr_left) {
			bytes_to_send = tport->max_pkt - hdr_size;
			if (bytes_to_send > TIPC_MAX_USER_MSG_SIZE)
				bytes_to_send = TIPC_MAX_USER_MSG_SIZE;
			if (curr_left < bytes_to_send)
				bytes_to_send = curr_left;
			my_iov.iov_base = curr_start;
			my_iov.iov_len = bytes_to_send;
			res = send_packet(NULL, sock, &my_msg, bytes_to_send);
			if (res < 0) {
				if (bytes_sent)
					res = bytes_sent;
				goto exit;
			}
			curr_left -= bytes_to_send;
			curr_start += bytes_to_send;
			bytes_sent += bytes_to_send;
		}

		curr_iov++;
	}
	res = bytes_sent;
exit:
	release_sock(sk);
	return res;
}

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;
	}

	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))) {
//.........这里部分代码省略.........

static int send_msg(struct kiocb *iocb, struct socket *sock,
		    struct msghdr *m, size_t total_len)
{
	struct sock *sk = sock->sk;
	struct tipc_port *tport = tipc_sk_port(sk);
	struct sockaddr_tipc *dest = (struct sockaddr_tipc *)m->msg_name;
	int needs_conn;
	long timeout_val;
	int res = -EINVAL;

	if (unlikely(!dest))
		return -EDESTADDRREQ;
	if (unlikely((m->msg_namelen < sizeof(*dest)) ||
		     (dest->family != AF_TIPC)))
		return -EINVAL;
	if ((total_len > TIPC_MAX_USER_MSG_SIZE) ||
	    (m->msg_iovlen > (unsigned)INT_MAX))
		return -EMSGSIZE;

	if (iocb)
		lock_sock(sk);

	needs_conn = (sock->state != SS_READY);
	if (unlikely(needs_conn)) {
		if (sock->state == SS_LISTENING) {
			res = -EPIPE;
			goto exit;
		}
		if (sock->state != SS_UNCONNECTED) {
			res = -EISCONN;
			goto exit;
		}
		if ((tport->published) ||
		    ((sock->type == SOCK_STREAM) && (total_len != 0))) {
			res = -EOPNOTSUPP;
			goto exit;
		}
		if (dest->addrtype == TIPC_ADDR_NAME) {
			tport->conn_type = dest->addr.name.name.type;
			tport->conn_instance = dest->addr.name.name.instance;
		}

		/* Abort any pending connection attempts (very unlikely) */

		reject_rx_queue(sk);
	}

	timeout_val = sock_sndtimeo(sk, m->msg_flags & MSG_DONTWAIT);

	do {
		if (dest->addrtype == TIPC_ADDR_NAME) {
			res = dest_name_check(dest, m);
			if (res)
				break;
			res = tipc_send2name(tport->ref,
					     &dest->addr.name.name,
					     dest->addr.name.domain,
					     m->msg_iovlen,
					     m->msg_iov,
					     total_len);
		} else if (dest->addrtype == TIPC_ADDR_ID) {
			res = tipc_send2port(tport->ref,
					     &dest->addr.id,
					     m->msg_iovlen,
					     m->msg_iov,
					     total_len);
		} else if (dest->addrtype == TIPC_ADDR_MCAST) {
			if (needs_conn) {
				res = -EOPNOTSUPP;
				break;
			}
			res = dest_name_check(dest, m);
			if (res)
				break;
			res = tipc_multicast(tport->ref,
					     &dest->addr.nameseq,
					     m->msg_iovlen,
					     m->msg_iov,
					     total_len);
		}
		if (likely(res != -ELINKCONG)) {
			if (needs_conn && (res >= 0))
				sock->state = SS_CONNECTING;
			break;
		}
		if (timeout_val <= 0L) {
			res = timeout_val ? timeout_val : -EWOULDBLOCK;
			break;
		}
		release_sock(sk);
		timeout_val = wait_event_interruptible_timeout(*sk_sleep(sk),
					       !tport->congested, timeout_val);
		lock_sock(sk);
	} while (1);

exit:
	if (iocb)
		release_sock(sk);
	return res;
}

static int release(struct socket *sock)
{
	struct sock *sk = sock->sk;
	struct tipc_port *tport;
	struct sk_buff *buf;
	int res;

	/*
	 * Exit if socket isn't fully initialized (occurs when a failed accept()
	 * releases a pre-allocated child socket that was never used)
	 */

	if (sk == NULL)
		return 0;

	tport = tipc_sk_port(sk);
	lock_sock(sk);

	/*
	 * Reject all unreceived messages, except on an active connection
	 * (which disconnects locally & sends a 'FIN+' to peer)
	 */

	while (sock->state != SS_DISCONNECTING) {
		buf = __skb_dequeue(&sk->sk_receive_queue);
		if (buf == NULL)
			break;
		atomic_dec(&tipc_queue_size);
		if (TIPC_SKB_CB(buf)->handle != 0)
			kfree_skb(buf);
		else {
			if ((sock->state == SS_CONNECTING) ||
			    (sock->state == SS_CONNECTED)) {
				sock->state = SS_DISCONNECTING;
				tipc_disconnect(tport->ref);
			}
			tipc_reject_msg(buf, TIPC_ERR_NO_PORT);
		}
	}

	/*
	 * Delete TIPC port; this ensures no more messages are queued
	 * (also disconnects an active connection & sends a 'FIN-' to peer)
	 */

	res = tipc_deleteport(tport->ref);

	/* Discard any remaining (connection-based) messages in receive queue */

	discard_rx_queue(sk);

	/* Reject any messages that accumulated in backlog queue */

	sock->state = SS_DISCONNECTING;
	release_sock(sk);

	sock_put(sk);
	sock->sk = NULL;

	return res;
}

static int accept(struct socket *sock, struct socket *new_sock, int flags)
{
	struct sock *sk = sock->sk;
	struct sk_buff *buf;
	int res;

	lock_sock(sk);

	if (sock->state != SS_LISTENING) {
		res = -EINVAL;
		goto exit;
	}

	while (skb_queue_empty(&sk->sk_receive_queue)) {
		if (flags & O_NONBLOCK) {
			res = -EWOULDBLOCK;
			goto exit;
		}
		release_sock(sk);
		res = wait_event_interruptible(*sk_sleep(sk),
				(!skb_queue_empty(&sk->sk_receive_queue)));
		lock_sock(sk);
		if (res)
			goto exit;
	}

	buf = skb_peek(&sk->sk_receive_queue);

	res = tipc_create(sock_net(sock->sk), new_sock, 0, 0);
	if (!res) {
		struct sock *new_sk = new_sock->sk;
		struct tipc_sock *new_tsock = tipc_sk(new_sk);
		struct tipc_port *new_tport = new_tsock->p;
		u32 new_ref = new_tport->ref;
		struct tipc_msg *msg = buf_msg(buf);

		lock_sock(new_sk);

		/*
		 * Reject any stray messages received by new socket
		 * before the socket lock was taken (very, very unlikely)
		 */

		reject_rx_queue(new_sk);

		/* Connect new socket to it's peer */

		new_tsock->peer_name.ref = msg_origport(msg);
		new_tsock->peer_name.node = msg_orignode(msg);
		tipc_connect2port(new_ref, &new_tsock->peer_name);
		new_sock->state = SS_CONNECTED;

		tipc_set_portimportance(new_ref, msg_importance(msg));
		if (msg_named(msg)) {
			new_tport->conn_type = msg_nametype(msg);
			new_tport->conn_instance = msg_nameinst(msg);
		}

		/*
		 * Respond to 'SYN-' by discarding it & returning 'ACK'-.
		 * Respond to 'SYN+' by queuing it on new socket.
		 */

		if (!msg_data_sz(msg)) {
			struct msghdr m = {NULL,};

			advance_rx_queue(sk);
			send_packet(NULL, new_sock, &m, 0);
		} else {
			__skb_dequeue(&sk->sk_receive_queue);
			__skb_queue_head(&new_sk->sk_receive_queue, buf);
		}
		release_sock(new_sk);
	}
exit:
	release_sock(sk);
	return res;
}

//.........这里部分代码省略.........
		case SO_TIMESTAMP:
			sk->sk_rcvtstamp = valbool;
			break;

		case SO_RCVLOWAT:
			if (val < 0)
				val = INT_MAX;
			sk->sk_rcvlowat = val ? : 1;
			break;

		case SO_RCVTIMEO:
			ret = sock_set_timeout(&sk->sk_rcvtimeo, optval, optlen);
			break;

		case SO_SNDTIMEO:
			ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen);
			break;

#ifdef CONFIG_NETDEVICES
		case SO_BINDTODEVICE:
		{
			char devname[IFNAMSIZ]; 

			/* Sorry... */ 
			if (!capable(CAP_NET_RAW)) {
				ret = -EPERM;
				break;
			}

			/* Bind this socket to a particular device like "eth0",
			 * as specified in the passed interface name. If the
			 * name is "" or the option length is zero the socket 
			 * is not bound. 
			 */ 

			if (!valbool) {
				sk->sk_bound_dev_if = 0;
			} else {
				if (optlen > IFNAMSIZ) 
					optlen = IFNAMSIZ; 
				if (copy_from_user(devname, optval, optlen)) {
					ret = -EFAULT;
					break;
				}

				/* Remove any cached route for this socket. */
				sk_dst_reset(sk);

				if (devname[0] == '\0') {
					sk->sk_bound_dev_if = 0;
				} else {
					struct net_device *dev = dev_get_by_name(devname);
					if (!dev) {
						ret = -ENODEV;
						break;
					}
					sk->sk_bound_dev_if = dev->ifindex;
					dev_put(dev);
				}
			}
			break;
		}
#endif


		case SO_ATTACH_FILTER:
			ret = -EINVAL;
			if (optlen == sizeof(struct sock_fprog)) {
				struct sock_fprog fprog;

				ret = -EFAULT;
				if (copy_from_user(&fprog, optval, sizeof(fprog)))
					break;

				ret = sk_attach_filter(&fprog, sk);
			}
			break;

		case SO_DETACH_FILTER:
			spin_lock_bh(&sk->sk_lock.slock);
			filter = sk->sk_filter;
                        if (filter) {
				sk->sk_filter = NULL;
				spin_unlock_bh(&sk->sk_lock.slock);
				sk_filter_release(sk, filter);
				break;
			}
			spin_unlock_bh(&sk->sk_lock.slock);
			ret = -ENONET;
			break;

		/* We implement the SO_SNDLOWAT etc to
		   not be settable (1003.1g 5.3) */
		default:
		  	ret = -ENOPROTOOPT;
			break;
  	}
	release_sock(sk);
	return ret;
}

//.........这里部分代码省略.........
			if (retv)
				break;
			omode = MCAST_INCLUDE;
			add = 1;
		} else /*IP_DROP_SOURCE_MEMBERSHIP */ {
			omode = MCAST_INCLUDE;
			add = 0;
		}
		retv = ip6_mc_source(add, omode, sk, &greqs);
		break;
	}
	case MCAST_MSFILTER:
	{
		extern int sysctl_optmem_max;
		extern int sysctl_mld_max_msf;
		struct group_filter *gsf;

		if (optlen < GROUP_FILTER_SIZE(0))
			goto e_inval;
		if (optlen > sysctl_optmem_max) {
			retv = -ENOBUFS;
			break;
		}
		gsf = (struct group_filter *)kmalloc(optlen,GFP_KERNEL);
		if (gsf == 0) {
			retv = -ENOBUFS;
			break;
		}
		retv = -EFAULT;
		if (copy_from_user(gsf, optval, optlen)) {
			kfree(gsf);
			break;
		}
		/* numsrc >= (4G-140)/128 overflow in 32 bits */
		if (gsf->gf_numsrc >= 0x1ffffffU ||
		    gsf->gf_numsrc > sysctl_mld_max_msf) {
			kfree(gsf);
			retv = -ENOBUFS;
			break;
		}
		if (GROUP_FILTER_SIZE(gsf->gf_numsrc) > optlen) {
			kfree(gsf);
			retv = -EINVAL;
			break;
		}
		retv = ip6_mc_msfilter(sk, gsf);
		kfree(gsf);

		break;
	}
	case IPV6_ROUTER_ALERT:
		retv = ip6_ra_control(sk, val, NULL);
		break;
	case IPV6_MTU_DISCOVER:
		if (val<0 || val>2)
			goto e_inval;
		np->pmtudisc = val;
		retv = 0;
		break;
	case IPV6_MTU:
		if (val && val < IPV6_MIN_MTU)
			goto e_inval;
		np->frag_size = val;
		retv = 0;
		break;
	case IPV6_RECVERR:
		np->recverr = valbool;
		if (!val)
			skb_queue_purge(&sk->sk_error_queue);
		retv = 0;
		break;
	case IPV6_FLOWINFO_SEND:
		np->sndflow = valbool;
		retv = 0;
		break;
	case IPV6_FLOWLABEL_MGR:
		retv = ipv6_flowlabel_opt(sk, optval, optlen);
		break;
	case IPV6_IPSEC_POLICY:
	case IPV6_XFRM_POLICY:
		retv = xfrm_user_policy(sk, optname, optval, optlen);
		break;

#ifdef CONFIG_NETFILTER
	default:
		retv = nf_setsockopt(sk, PF_INET6, optname, optval, 
					    optlen);
		break;
#endif

	}
	release_sock(sk);

out:
	return retv;

e_inval:
	release_sock(sk);
	return -EINVAL;
}

//.........这里部分代码省略.........

	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, 0);
		}
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, 0);
		break;
	} while (1);
out:
	release_sock(sk);
	return len;
}