/*

   * Copyright (c) 2006, 2019 Oracle and/or its affiliates. All rights reserved.

   *
   * This software is available to you under a choice of one of two
   * licenses.  You may choose to be licensed under the terms of the GNU
   * General Public License (GPL) Version 2, available from the file
   * COPYING in the main directory of this source tree, or the
   * OpenIB.org BSD license below:
   *
   *     Redistribution and use in source and binary forms, with or
   *     without modification, are permitted provided that the following
   *     conditions are met:
   *
   *      - Redistributions of source code must retain the above
   *        copyright notice, this list of conditions and the following
   *        disclaimer.
   *
   *      - Redistributions in binary form must reproduce the above
   *        copyright notice, this list of conditions and the following
   *        disclaimer in the documentation and/or other materials
   *        provided with the distribution.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
   * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
   * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
   * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
   * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   * SOFTWARE.
   *
   */
  #include <linux/module.h>
  #include <linux/errno.h>
  #include <linux/kernel.h>

  #include <linux/gfp.h>

  #include <linux/in.h>

  #include <linux/ipv6.h>

  #include <linux/poll.h>

  #include <net/sock.h>
  
  #include "rds.h"

  
  /* this is just used for stats gathering :/ */
  static DEFINE_SPINLOCK(rds_sock_lock);
  static unsigned long rds_sock_count;
  static LIST_HEAD(rds_sock_list);
  DECLARE_WAIT_QUEUE_HEAD(rds_poll_waitq);
  
  /*
   * This is called as the final descriptor referencing this socket is closed.
   * We have to unbind the socket so that another socket can be bound to the
   * address it was using.
   *
   * We have to be careful about racing with the incoming path.  sock_orphan()
   * sets SOCK_DEAD and we use that as an indicator to the rx path that new
   * messages shouldn't be queued.
   */
  static int rds_release(struct socket *sock)
  {
  	struct sock *sk = sock->sk;
  	struct rds_sock *rs;

  	if (!sk)

  		goto out;
  
  	rs = rds_sk_to_rs(sk);
  
  	sock_orphan(sk);
  	/* Note - rds_clear_recv_queue grabs rs_recv_lock, so
  	 * that ensures the recv path has completed messing
  	 * with the socket. */
  	rds_clear_recv_queue(rs);
  	rds_cong_remove_socket(rs);

  	rds_remove_bound(rs);

  	rds_send_drop_to(rs, NULL);
  	rds_rdma_drop_keys(rs);
  	rds_notify_queue_get(rs, NULL);

  	rds_notify_msg_zcopy_purge(&rs->rs_zcookie_queue);

  	spin_lock_bh(&rds_sock_lock);

  	list_del_init(&rs->rs_item);
  	rds_sock_count--;

  	spin_unlock_bh(&rds_sock_lock);

  	rds_trans_put(rs->rs_transport);

  	sock->sk = NULL;
  	sock_put(sk);
  out:
  	return 0;
  }
  
  /*
   * Careful not to race with rds_release -> sock_orphan which clears sk_sleep.
   * _bh() isn't OK here, we're called from interrupt handlers.  It's probably OK
   * to wake the waitqueue after sk_sleep is clear as we hold a sock ref, but
   * this seems more conservative.
   * NB - normally, one would use sk_callback_lock for this, but we can
   * get here from interrupts, whereas the network code grabs sk_callback_lock
   * with _lock_bh only - so relying on sk_callback_lock introduces livelocks.
   */
  void rds_wake_sk_sleep(struct rds_sock *rs)
  {
  	unsigned long flags;
  
  	read_lock_irqsave(&rs->rs_recv_lock, flags);
  	__rds_wake_sk_sleep(rds_rs_to_sk(rs));
  	read_unlock_irqrestore(&rs->rs_recv_lock, flags);
  }
  
  static int rds_getname(struct socket *sock, struct sockaddr *uaddr,

  		       int peer)

  {

  	struct rds_sock *rs = rds_sk_to_rs(sock->sk);

  	struct sockaddr_in6 *sin6;
  	struct sockaddr_in *sin;
  	int uaddr_len;

  
  	/* racey, don't care */
  	if (peer) {

  		if (ipv6_addr_any(&rs->rs_conn_addr))

  			return -ENOTCONN;

  		if (ipv6_addr_v4mapped(&rs->rs_conn_addr)) {
  			sin = (struct sockaddr_in *)uaddr;
  			memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
  			sin->sin_family = AF_INET;
  			sin->sin_port = rs->rs_conn_port;
  			sin->sin_addr.s_addr = rs->rs_conn_addr_v4;
  			uaddr_len = sizeof(*sin);
  		} else {
  			sin6 = (struct sockaddr_in6 *)uaddr;
  			sin6->sin6_family = AF_INET6;
  			sin6->sin6_port = rs->rs_conn_port;
  			sin6->sin6_addr = rs->rs_conn_addr;
  			sin6->sin6_flowinfo = 0;
  			/* scope_id is the same as in the bound address. */
  			sin6->sin6_scope_id = rs->rs_bound_scope_id;
  			uaddr_len = sizeof(*sin6);
  		}

  	} else {

  		/* If socket is not yet bound and the socket is connected,
  		 * set the return address family to be the same as the
  		 * connected address, but with 0 address value.  If it is not
  		 * connected, set the family to be AF_UNSPEC (value 0) and
  		 * the address size to be that of an IPv4 address.

  		 */
  		if (ipv6_addr_any(&rs->rs_bound_addr)) {

  			if (ipv6_addr_any(&rs->rs_conn_addr)) {
  				sin = (struct sockaddr_in *)uaddr;
  				memset(sin, 0, sizeof(*sin));
  				sin->sin_family = AF_UNSPEC;
  				return sizeof(*sin);
  			}

  #if IS_ENABLED(CONFIG_IPV6)
  			if (!(ipv6_addr_type(&rs->rs_conn_addr) &
  			      IPV6_ADDR_MAPPED)) {
  				sin6 = (struct sockaddr_in6 *)uaddr;
  				memset(sin6, 0, sizeof(*sin6));
  				sin6->sin6_family = AF_INET6;
  				return sizeof(*sin6);

  			}

  #endif

  			sin = (struct sockaddr_in *)uaddr;
  			memset(sin, 0, sizeof(*sin));
  			sin->sin_family = AF_INET;
  			return sizeof(*sin);

  		}
  		if (ipv6_addr_v4mapped(&rs->rs_bound_addr)) {
  			sin = (struct sockaddr_in *)uaddr;
  			memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
  			sin->sin_family = AF_INET;
  			sin->sin_port = rs->rs_bound_port;
  			sin->sin_addr.s_addr = rs->rs_bound_addr_v4;
  			uaddr_len = sizeof(*sin);
  		} else {
  			sin6 = (struct sockaddr_in6 *)uaddr;
  			sin6->sin6_family = AF_INET6;
  			sin6->sin6_port = rs->rs_bound_port;
  			sin6->sin6_addr = rs->rs_bound_addr;
  			sin6->sin6_flowinfo = 0;
  			sin6->sin6_scope_id = rs->rs_bound_scope_id;
  			uaddr_len = sizeof(*sin6);
  		}

  	}

  	return uaddr_len;

  }
  
  /*
   * RDS' poll is without a doubt the least intuitive part of the interface,

   * as EPOLLIN and EPOLLOUT do not behave entirely as you would expect from

   * a network protocol.
   *

   * EPOLLIN is asserted if

   *  -	there is data on the receive queue.
   *  -	to signal that a previously congested destination may have become
   *	uncongested
   *  -	A notification has been queued to the socket (this can be a congestion

   *	update, or a RDMA completion, or a MSG_ZEROCOPY completion).

   *

   * EPOLLOUT is asserted if there is room on the send queue. This does not mean

   * however, that the next sendmsg() call will succeed. If the application tries
   * to send to a congested destination, the system call may still fail (and
   * return ENOBUFS).
   */

  static __poll_t rds_poll(struct file *file, struct socket *sock,

  			     poll_table *wait)
  {
  	struct sock *sk = sock->sk;
  	struct rds_sock *rs = rds_sk_to_rs(sk);

  	__poll_t mask = 0;

  	unsigned long flags;

  	poll_wait(file, sk_sleep(sk), wait);

  	if (rs->rs_seen_congestion)
  		poll_wait(file, &rds_poll_waitq, wait);

  
  	read_lock_irqsave(&rs->rs_recv_lock, flags);
  	if (!rs->rs_cong_monitor) {

  		/* When a congestion map was updated, we signal EPOLLIN for

  		 * "historical" reasons. Applications can also poll for
  		 * WRBAND instead. */
  		if (rds_cong_updated_since(&rs->rs_cong_track))

  			mask |= (EPOLLIN | EPOLLRDNORM | EPOLLWRBAND);

  	} else {
  		spin_lock(&rs->rs_lock);
  		if (rs->rs_cong_notify)

  			mask |= (EPOLLIN | EPOLLRDNORM);

  		spin_unlock(&rs->rs_lock);
  	}

  	if (!list_empty(&rs->rs_recv_queue) ||

  	    !list_empty(&rs->rs_notify_queue) ||

  	    !list_empty(&rs->rs_zcookie_queue.zcookie_head))

  		mask |= (EPOLLIN | EPOLLRDNORM);

  	if (rs->rs_snd_bytes < rds_sk_sndbuf(rs))

  		mask |= (EPOLLOUT | EPOLLWRNORM);

  	if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
  		mask |= POLLERR;

  	read_unlock_irqrestore(&rs->rs_recv_lock, flags);

  	/* clear state any time we wake a seen-congested socket */
  	if (mask)
  		rs->rs_seen_congestion = 0;

  	return mask;
  }
  
  static int rds_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
  {

  	struct rds_sock *rs = rds_sk_to_rs(sock->sk);

  	rds_tos_t utos, tos = 0;

  
  	switch (cmd) {
  	case SIOCRDSSETTOS:

  		if (get_user(utos, (rds_tos_t __user *)arg))

  			return -EFAULT;
  
  		if (rs->rs_transport &&

  		    rs->rs_transport->get_tos_map)
  			tos = rs->rs_transport->get_tos_map(utos);
  		else
  			return -ENOIOCTLCMD;

  
  		spin_lock_bh(&rds_sock_lock);
  		if (rs->rs_tos || rs->rs_conn) {
  			spin_unlock_bh(&rds_sock_lock);
  			return -EINVAL;
  		}
  		rs->rs_tos = tos;
  		spin_unlock_bh(&rds_sock_lock);
  		break;
  	case SIOCRDSGETTOS:
  		spin_lock_bh(&rds_sock_lock);
  		tos = rs->rs_tos;
  		spin_unlock_bh(&rds_sock_lock);
  		if (put_user(tos, (rds_tos_t __user *)arg))
  			return -EFAULT;
  		break;
  	default:
  		return -ENOIOCTLCMD;
  	}
  
  	return 0;

  }

  static int rds_cancel_sent_to(struct rds_sock *rs, sockptr_t optval, int len)

  {

  	struct sockaddr_in6 sin6;

  	struct sockaddr_in sin;
  	int ret = 0;
  
  	/* racing with another thread binding seems ok here */

  	if (ipv6_addr_any(&rs->rs_bound_addr)) {

  		ret = -ENOTCONN; /* XXX not a great errno */
  		goto out;
  	}
  
  	if (len < sizeof(struct sockaddr_in)) {
  		ret = -EINVAL;
  		goto out;

  	} else if (len < sizeof(struct sockaddr_in6)) {
  		/* Assume IPv4 */

  		if (copy_from_sockptr(&sin, optval,
  				sizeof(struct sockaddr_in))) {

  			ret = -EFAULT;
  			goto out;
  		}
  		ipv6_addr_set_v4mapped(sin.sin_addr.s_addr, &sin6.sin6_addr);
  		sin6.sin6_port = sin.sin_port;
  	} else {

  		if (copy_from_sockptr(&sin6, optval,

  				   sizeof(struct sockaddr_in6))) {
  			ret = -EFAULT;
  			goto out;
  		}

  	}

  	rds_send_drop_to(rs, &sin6);

  out:
  	return ret;
  }

  static int rds_set_bool_option(unsigned char *optvar, sockptr_t optval,

  			       int optlen)
  {
  	int value;
  
  	if (optlen < sizeof(int))
  		return -EINVAL;

  	if (copy_from_sockptr(&value, optval, sizeof(int)))

  		return -EFAULT;
  	*optvar = !!value;
  	return 0;
  }

  static int rds_cong_monitor(struct rds_sock *rs, sockptr_t optval, int optlen)

  {
  	int ret;
  
  	ret = rds_set_bool_option(&rs->rs_cong_monitor, optval, optlen);
  	if (ret == 0) {
  		if (rs->rs_cong_monitor) {
  			rds_cong_add_socket(rs);
  		} else {
  			rds_cong_remove_socket(rs);
  			rs->rs_cong_mask = 0;
  			rs->rs_cong_notify = 0;
  		}
  	}
  	return ret;
  }

  static int rds_set_transport(struct rds_sock *rs, sockptr_t optval, int optlen)

  {
  	int t_type;
  
  	if (rs->rs_transport)
  		return -EOPNOTSUPP; /* previously attached to transport */
  
  	if (optlen != sizeof(int))
  		return -EINVAL;

  	if (copy_from_sockptr(&t_type, optval, sizeof(t_type)))

  		return -EFAULT;
  
  	if (t_type < 0 || t_type >= RDS_TRANS_COUNT)
  		return -EINVAL;
  
  	rs->rs_transport = rds_trans_get(t_type);
  
  	return rs->rs_transport ? 0 : -ENOPROTOOPT;
  }

  static int rds_enable_recvtstamp(struct sock *sk, sockptr_t optval,

  				 int optlen, int optname)

  {
  	int val, valbool;
  
  	if (optlen != sizeof(int))
  		return -EFAULT;

  	if (copy_from_sockptr(&val, optval, sizeof(int)))

  		return -EFAULT;
  
  	valbool = val ? 1 : 0;

  	if (optname == SO_TIMESTAMP_NEW)
  		sock_set_flag(sk, SOCK_TSTAMP_NEW);

  	if (valbool)
  		sock_set_flag(sk, SOCK_RCVTSTAMP);
  	else
  		sock_reset_flag(sk, SOCK_RCVTSTAMP);
  
  	return 0;
  }

  static int rds_recv_track_latency(struct rds_sock *rs, sockptr_t optval,

  				  int optlen)
  {
  	struct rds_rx_trace_so trace;
  	int i;
  
  	if (optlen != sizeof(struct rds_rx_trace_so))
  		return -EFAULT;

  	if (copy_from_sockptr(&trace, optval, sizeof(trace)))

  		return -EFAULT;

  	if (trace.rx_traces > RDS_MSG_RX_DGRAM_TRACE_MAX)
  		return -EFAULT;

  	rs->rs_rx_traces = trace.rx_traces;
  	for (i = 0; i < rs->rs_rx_traces; i++) {
  		if (trace.rx_trace_pos[i] > RDS_MSG_RX_DGRAM_TRACE_MAX) {
  			rs->rs_rx_traces = 0;
  			return -EFAULT;
  		}
  		rs->rs_rx_trace[i] = trace.rx_trace_pos[i];
  	}
  
  	return 0;
  }

  static int rds_setsockopt(struct socket *sock, int level, int optname,

  			  sockptr_t optval, unsigned int optlen)

  {
  	struct rds_sock *rs = rds_sk_to_rs(sock->sk);
  	int ret;
  
  	if (level != SOL_RDS) {
  		ret = -ENOPROTOOPT;
  		goto out;
  	}
  
  	switch (optname) {
  	case RDS_CANCEL_SENT_TO:
  		ret = rds_cancel_sent_to(rs, optval, optlen);
  		break;
  	case RDS_GET_MR:
  		ret = rds_get_mr(rs, optval, optlen);
  		break;

  	case RDS_GET_MR_FOR_DEST:
  		ret = rds_get_mr_for_dest(rs, optval, optlen);
  		break;

  	case RDS_FREE_MR:
  		ret = rds_free_mr(rs, optval, optlen);
  		break;
  	case RDS_RECVERR:
  		ret = rds_set_bool_option(&rs->rs_recverr, optval, optlen);
  		break;
  	case RDS_CONG_MONITOR:
  		ret = rds_cong_monitor(rs, optval, optlen);
  		break;

  	case SO_RDS_TRANSPORT:
  		lock_sock(sock->sk);
  		ret = rds_set_transport(rs, optval, optlen);
  		release_sock(sock->sk);
  		break;

  	case SO_TIMESTAMP_OLD:

  	case SO_TIMESTAMP_NEW:

  		lock_sock(sock->sk);

  		ret = rds_enable_recvtstamp(sock->sk, optval, optlen, optname);

  		release_sock(sock->sk);
  		break;

  	case SO_RDS_MSG_RXPATH_LATENCY:
  		ret = rds_recv_track_latency(rs, optval, optlen);
  		break;

  	default:
  		ret = -ENOPROTOOPT;
  	}
  out:
  	return ret;
  }
  
  static int rds_getsockopt(struct socket *sock, int level, int optname,
  			  char __user *optval, int __user *optlen)
  {
  	struct rds_sock *rs = rds_sk_to_rs(sock->sk);
  	int ret = -ENOPROTOOPT, len;

  	int trans;

  
  	if (level != SOL_RDS)
  		goto out;
  
  	if (get_user(len, optlen)) {
  		ret = -EFAULT;
  		goto out;
  	}
  
  	switch (optname) {
  	case RDS_INFO_FIRST ... RDS_INFO_LAST:
  		ret = rds_info_getsockopt(sock, optname, optval,
  					  optlen);
  		break;
  
  	case RDS_RECVERR:
  		if (len < sizeof(int))
  			ret = -EINVAL;
  		else

  		if (put_user(rs->rs_recverr, (int __user *) optval) ||
  		    put_user(sizeof(int), optlen))

  			ret = -EFAULT;
  		else
  			ret = 0;
  		break;

  	case SO_RDS_TRANSPORT:
  		if (len < sizeof(int)) {
  			ret = -EINVAL;
  			break;
  		}
  		trans = (rs->rs_transport ? rs->rs_transport->t_type :
  			 RDS_TRANS_NONE); /* unbound */
  		if (put_user(trans, (int __user *)optval) ||
  		    put_user(sizeof(int), optlen))
  			ret = -EFAULT;
  		else
  			ret = 0;
  		break;

  	default:
  		break;
  	}
  
  out:
  	return ret;
  
  }
  
  static int rds_connect(struct socket *sock, struct sockaddr *uaddr,
  		       int addr_len, int flags)
  {
  	struct sock *sk = sock->sk;

  	struct sockaddr_in *sin;

  	struct rds_sock *rs = rds_sk_to_rs(sk);
  	int ret = 0;

  	if (addr_len < offsetofend(struct sockaddr, sa_family))
  		return -EINVAL;

  	lock_sock(sk);

  	switch (uaddr->sa_family) {
  	case AF_INET:

  		sin = (struct sockaddr_in *)uaddr;

  		if (addr_len < sizeof(struct sockaddr_in)) {
  			ret = -EINVAL;

  			break;
  		}
  		if (sin->sin_addr.s_addr == htonl(INADDR_ANY)) {
  			ret = -EDESTADDRREQ;
  			break;
  		}

  		if (ipv4_is_multicast(sin->sin_addr.s_addr) ||

  		    sin->sin_addr.s_addr == htonl(INADDR_BROADCAST)) {
  			ret = -EINVAL;
  			break;
  		}
  		ipv6_addr_set_v4mapped(sin->sin_addr.s_addr, &rs->rs_conn_addr);
  		rs->rs_conn_port = sin->sin_port;
  		break;

  #if IS_ENABLED(CONFIG_IPV6)
  	case AF_INET6: {
  		struct sockaddr_in6 *sin6;
  		int addr_type;

  		sin6 = (struct sockaddr_in6 *)uaddr;
  		if (addr_len < sizeof(struct sockaddr_in6)) {
  			ret = -EINVAL;
  			break;
  		}
  		addr_type = ipv6_addr_type(&sin6->sin6_addr);
  		if (!(addr_type & IPV6_ADDR_UNICAST)) {
  			__be32 addr4;
  
  			if (!(addr_type & IPV6_ADDR_MAPPED)) {
  				ret = -EPROTOTYPE;
  				break;
  			}
  
  			/* It is a mapped address.  Need to do some sanity
  			 * checks.
  			 */
  			addr4 = sin6->sin6_addr.s6_addr32[3];
  			if (addr4 == htonl(INADDR_ANY) ||
  			    addr4 == htonl(INADDR_BROADCAST) ||

  			    ipv4_is_multicast(addr4)) {

  				ret = -EPROTOTYPE;
  				break;
  			}
  		}
  
  		if (addr_type & IPV6_ADDR_LINKLOCAL) {
  			/* If socket is arleady bound to a link local address,
  			 * the peer address must be on the same link.
  			 */
  			if (sin6->sin6_scope_id == 0 ||
  			    (!ipv6_addr_any(&rs->rs_bound_addr) &&
  			     rs->rs_bound_scope_id &&
  			     sin6->sin6_scope_id != rs->rs_bound_scope_id)) {
  				ret = -EINVAL;
  				break;
  			}
  			/* Remember the connected address scope ID.  It will
  			 * be checked against the binding local address when
  			 * the socket is bound.
  			 */
  			rs->rs_bound_scope_id = sin6->sin6_scope_id;
  		}
  		rs->rs_conn_addr = sin6->sin6_addr;
  		rs->rs_conn_port = sin6->sin6_port;

  		break;

  	}
  #endif

  	default:

  		ret = -EAFNOSUPPORT;

  		break;

  	}

  	release_sock(sk);
  	return ret;
  }
  
  static struct proto rds_proto = {
  	.name	  = "RDS",
  	.owner	  = THIS_MODULE,
  	.obj_size = sizeof(struct rds_sock),
  };

  static const struct proto_ops rds_proto_ops = {

  	.family =	AF_RDS,
  	.owner =	THIS_MODULE,
  	.release =	rds_release,
  	.bind =		rds_bind,
  	.connect =	rds_connect,
  	.socketpair =	sock_no_socketpair,
  	.accept =	sock_no_accept,
  	.getname =	rds_getname,
  	.poll =		rds_poll,
  	.ioctl =	rds_ioctl,
  	.listen =	sock_no_listen,
  	.shutdown =	sock_no_shutdown,
  	.setsockopt =	rds_setsockopt,
  	.getsockopt =	rds_getsockopt,
  	.sendmsg =	rds_sendmsg,
  	.recvmsg =	rds_recvmsg,
  	.mmap =		sock_no_mmap,
  	.sendpage =	sock_no_sendpage,
  };

  static void rds_sock_destruct(struct sock *sk)
  {
  	struct rds_sock *rs = rds_sk_to_rs(sk);
  
  	WARN_ON((&rs->rs_item != rs->rs_item.next ||
  		 &rs->rs_item != rs->rs_item.prev));
  }

  static int __rds_create(struct socket *sock, struct sock *sk, int protocol)
  {

  	struct rds_sock *rs;
  
  	sock_init_data(sock, sk);
  	sock->ops		= &rds_proto_ops;
  	sk->sk_protocol		= protocol;

  	sk->sk_destruct		= rds_sock_destruct;

  
  	rs = rds_sk_to_rs(sk);
  	spin_lock_init(&rs->rs_lock);
  	rwlock_init(&rs->rs_recv_lock);
  	INIT_LIST_HEAD(&rs->rs_send_queue);
  	INIT_LIST_HEAD(&rs->rs_recv_queue);
  	INIT_LIST_HEAD(&rs->rs_notify_queue);
  	INIT_LIST_HEAD(&rs->rs_cong_list);

  	rds_message_zcopy_queue_init(&rs->rs_zcookie_queue);

  	spin_lock_init(&rs->rs_rdma_lock);
  	rs->rs_rdma_keys = RB_ROOT;

  	rs->rs_rx_traces = 0;

  	rs->rs_tos = 0;
  	rs->rs_conn = NULL;

  	spin_lock_bh(&rds_sock_lock);

  	list_add_tail(&rs->rs_item, &rds_sock_list);
  	rds_sock_count++;

  	spin_unlock_bh(&rds_sock_lock);

  
  	return 0;
  }

  static int rds_create(struct net *net, struct socket *sock, int protocol,
  		      int kern)

  {
  	struct sock *sk;
  
  	if (sock->type != SOCK_SEQPACKET || protocol)
  		return -ESOCKTNOSUPPORT;

  	sk = sk_alloc(net, AF_RDS, GFP_KERNEL, &rds_proto, kern);

  	if (!sk)
  		return -ENOMEM;
  
  	return __rds_create(sock, sk, protocol);
  }
  
  void rds_sock_addref(struct rds_sock *rs)
  {
  	sock_hold(rds_rs_to_sk(rs));
  }
  
  void rds_sock_put(struct rds_sock *rs)
  {
  	sock_put(rds_rs_to_sk(rs));
  }

  static const struct net_proto_family rds_family_ops = {

  	.family =	AF_RDS,
  	.create =	rds_create,
  	.owner	=	THIS_MODULE,
  };
  
  static void rds_sock_inc_info(struct socket *sock, unsigned int len,
  			      struct rds_info_iterator *iter,
  			      struct rds_info_lengths *lens)
  {
  	struct rds_sock *rs;

  	struct rds_incoming *inc;

  	unsigned int total = 0;
  
  	len /= sizeof(struct rds_info_message);

  	spin_lock_bh(&rds_sock_lock);

  
  	list_for_each_entry(rs, &rds_sock_list, rs_item) {

  		/* This option only supports IPv4 sockets. */
  		if (!ipv6_addr_v4mapped(&rs->rs_bound_addr))
  			continue;

  		read_lock(&rs->rs_recv_lock);
  
  		/* XXX too lazy to maintain counts.. */
  		list_for_each_entry(inc, &rs->rs_recv_queue, i_item) {
  			total++;
  			if (total <= len)

  				rds_inc_info_copy(inc, iter,
  						  inc->i_saddr.s6_addr32[3],
  						  rs->rs_bound_addr_v4,
  						  1);

  		}
  
  		read_unlock(&rs->rs_recv_lock);
  	}

  	spin_unlock_bh(&rds_sock_lock);

  
  	lens->nr = total;
  	lens->each = sizeof(struct rds_info_message);
  }

  #if IS_ENABLED(CONFIG_IPV6)
  static void rds6_sock_inc_info(struct socket *sock, unsigned int len,
  			       struct rds_info_iterator *iter,
  			       struct rds_info_lengths *lens)
  {
  	struct rds_incoming *inc;
  	unsigned int total = 0;
  	struct rds_sock *rs;
  
  	len /= sizeof(struct rds6_info_message);
  
  	spin_lock_bh(&rds_sock_lock);
  
  	list_for_each_entry(rs, &rds_sock_list, rs_item) {
  		read_lock(&rs->rs_recv_lock);
  
  		list_for_each_entry(inc, &rs->rs_recv_queue, i_item) {
  			total++;
  			if (total <= len)
  				rds6_inc_info_copy(inc, iter, &inc->i_saddr,
  						   &rs->rs_bound_addr, 1);
  		}
  
  		read_unlock(&rs->rs_recv_lock);
  	}
  
  	spin_unlock_bh(&rds_sock_lock);
  
  	lens->nr = total;
  	lens->each = sizeof(struct rds6_info_message);
  }
  #endif

  static void rds_sock_info(struct socket *sock, unsigned int len,
  			  struct rds_info_iterator *iter,
  			  struct rds_info_lengths *lens)
  {
  	struct rds_info_socket sinfo;

  	unsigned int cnt = 0;

  	struct rds_sock *rs;

  
  	len /= sizeof(struct rds_info_socket);

  	spin_lock_bh(&rds_sock_lock);

  	if (len < rds_sock_count) {
  		cnt = rds_sock_count;

  		goto out;

  	}

  
  	list_for_each_entry(rs, &rds_sock_list, rs_item) {

  		/* This option only supports IPv4 sockets. */
  		if (!ipv6_addr_v4mapped(&rs->rs_bound_addr))
  			continue;

  		sinfo.sndbuf = rds_sk_sndbuf(rs);
  		sinfo.rcvbuf = rds_sk_rcvbuf(rs);

  		sinfo.bound_addr = rs->rs_bound_addr_v4;
  		sinfo.connected_addr = rs->rs_conn_addr_v4;

  		sinfo.bound_port = rs->rs_bound_port;
  		sinfo.connected_port = rs->rs_conn_port;
  		sinfo.inum = sock_i_ino(rds_rs_to_sk(rs));
  
  		rds_info_copy(iter, &sinfo, sizeof(sinfo));

  		cnt++;

  	}
  
  out:

  	lens->nr = cnt;

  	lens->each = sizeof(struct rds_info_socket);

  	spin_unlock_bh(&rds_sock_lock);

  }

  #if IS_ENABLED(CONFIG_IPV6)
  static void rds6_sock_info(struct socket *sock, unsigned int len,
  			   struct rds_info_iterator *iter,
  			   struct rds_info_lengths *lens)
  {
  	struct rds6_info_socket sinfo6;
  	struct rds_sock *rs;
  
  	len /= sizeof(struct rds6_info_socket);
  
  	spin_lock_bh(&rds_sock_lock);
  
  	if (len < rds_sock_count)
  		goto out;
  
  	list_for_each_entry(rs, &rds_sock_list, rs_item) {
  		sinfo6.sndbuf = rds_sk_sndbuf(rs);
  		sinfo6.rcvbuf = rds_sk_rcvbuf(rs);
  		sinfo6.bound_addr = rs->rs_bound_addr;
  		sinfo6.connected_addr = rs->rs_conn_addr;
  		sinfo6.bound_port = rs->rs_bound_port;
  		sinfo6.connected_port = rs->rs_conn_port;
  		sinfo6.inum = sock_i_ino(rds_rs_to_sk(rs));
  
  		rds_info_copy(iter, &sinfo6, sizeof(sinfo6));
  	}
  
   out:
  	lens->nr = rds_sock_count;
  	lens->each = sizeof(struct rds6_info_socket);
  
  	spin_unlock_bh(&rds_sock_lock);
  }
  #endif

  static void rds_exit(void)

  {

  	sock_unregister(rds_family_ops.family);
  	proto_unregister(&rds_proto);
  	rds_conn_exit();
  	rds_cong_exit();
  	rds_sysctl_exit();
  	rds_threads_exit();
  	rds_stats_exit();
  	rds_page_exit();

  	rds_bind_lock_destroy();

  	rds_info_deregister_func(RDS_INFO_SOCKETS, rds_sock_info);
  	rds_info_deregister_func(RDS_INFO_RECV_MESSAGES, rds_sock_inc_info);

  #if IS_ENABLED(CONFIG_IPV6)
  	rds_info_deregister_func(RDS6_INFO_SOCKETS, rds6_sock_info);
  	rds_info_deregister_func(RDS6_INFO_RECV_MESSAGES, rds6_sock_inc_info);
  #endif

  }
  module_exit(rds_exit);

  u32 rds_gen_num;

  static int rds_init(void)

  {
  	int ret;

  	net_get_random_once(&rds_gen_num, sizeof(rds_gen_num));

  	ret = rds_bind_lock_init();
  	if (ret)
  		goto out;

  	ret = rds_conn_init();
  	if (ret)

  		goto out_bind;

  	ret = rds_threads_init();
  	if (ret)
  		goto out_conn;
  	ret = rds_sysctl_init();
  	if (ret)
  		goto out_threads;
  	ret = rds_stats_init();
  	if (ret)
  		goto out_sysctl;
  	ret = proto_register(&rds_proto, 1);
  	if (ret)
  		goto out_stats;
  	ret = sock_register(&rds_family_ops);
  	if (ret)
  		goto out_proto;
  
  	rds_info_register_func(RDS_INFO_SOCKETS, rds_sock_info);
  	rds_info_register_func(RDS_INFO_RECV_MESSAGES, rds_sock_inc_info);

  #if IS_ENABLED(CONFIG_IPV6)
  	rds_info_register_func(RDS6_INFO_SOCKETS, rds6_sock_info);
  	rds_info_register_func(RDS6_INFO_RECV_MESSAGES, rds6_sock_inc_info);
  #endif

  	goto out;

  out_proto:
  	proto_unregister(&rds_proto);
  out_stats:
  	rds_stats_exit();
  out_sysctl:
  	rds_sysctl_exit();
  out_threads:
  	rds_threads_exit();
  out_conn:
  	rds_conn_exit();
  	rds_cong_exit();
  	rds_page_exit();

  out_bind:
  	rds_bind_lock_destroy();

  out:
  	return ret;
  }
  module_init(rds_init);
  
  #define DRV_VERSION     "4.0"
  #define DRV_RELDATE     "Feb 12, 2009"
  
  MODULE_AUTHOR("Oracle Corporation <rds-devel@oss.oracle.com>");
  MODULE_DESCRIPTION("RDS: Reliable Datagram Sockets"
  		   " v" DRV_VERSION " (" DRV_RELDATE ")");
  MODULE_VERSION(DRV_VERSION);
  MODULE_LICENSE("Dual BSD/GPL");
  MODULE_ALIAS_NETPROTO(PF_RDS);