RDS: Socket interface

/*

 * Copyright (c) 2006 Oracle.  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/in.h>

#include <linux/poll.h>

#include <linux/version.h>

#include <net/sock.h>

#include "rds.h"

#include "rdma.h"

#include "rdma_transport.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;

	unsigned long flags;

	if (sk == NULL)

		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);

	spin_lock_irqsave(&rds_sock_lock, flags);

	list_del_init(&rs->rs_item);

	rds_sock_count--;

	spin_unlock_irqrestore(&rds_sock_lock, flags);

	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 *uaddr_len, int peer)

{

	struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;

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

	memset(sin->sin_zero, 0, sizeof(sin->sin_zero));

	/* racey, don't care */

	if (peer) {

		if (!rs->rs_conn_addr)

			return -ENOTCONN;

		sin->sin_port = rs->rs_conn_port;

		sin->sin_addr.s_addr = rs->rs_conn_addr;

	} else {

		sin->sin_port = rs->rs_bound_port;

		sin->sin_addr.s_addr = rs->rs_bound_addr;

	}

	sin->sin_family = AF_INET;

	*uaddr_len = sizeof(*sin);

	return 0;

}

/*

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

 * as POLLIN and POLLOUT do not behave entirely as you would expect from

 * a network protocol.

 *

 * POLLIN 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).

 *

 * POLLOUT 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 unsigned int 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);

	unsigned int mask = 0;

	unsigned long flags;

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

	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 POLLIN for

		 * "historical" reasons. Applications can also poll for

		 * WRBAND instead. */

		if (rds_cong_updated_since(&rs->rs_cong_track))

			mask |= (POLLIN | POLLRDNORM | POLLWRBAND);

	} else {

		spin_lock(&rs->rs_lock);

		if (rs->rs_cong_notify)

			mask |= (POLLIN | POLLRDNORM);

		spin_unlock(&rs->rs_lock);

	}

	if (!list_empty(&rs->rs_recv_queue)

	 || !list_empty(&rs->rs_notify_queue))

		mask |= (POLLIN | POLLRDNORM);

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

		mask |= (POLLOUT | POLLWRNORM);

	read_unlock_irqrestore(&rs->rs_recv_lock, flags);

	return mask;

}

static int rds_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)

{

	return -ENOIOCTLCMD;

}

static int rds_cancel_sent_to(struct rds_sock *rs, char __user *optval,

			      int len)

{

	struct sockaddr_in sin;

	int ret = 0;

	/* racing with another thread binding seems ok here */

	if (rs->rs_bound_addr == 0) {

		ret = -ENOTCONN; /* XXX not a great errno */

		goto out;

	}

	if (len < sizeof(struct sockaddr_in)) {

		ret = -EINVAL;

		goto out;

	}

	if (copy_from_user(&sin, optval, sizeof(sin))) {

		ret = -EFAULT;

		goto out;

	}

	rds_send_drop_to(rs, &sin);

out:

	return ret;

}

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

			       int optlen)

{

	int value;

	if (optlen < sizeof(int))

		return -EINVAL;

	if (get_user(value, (int __user *) optval))

		return -EFAULT;

	*optvar = !!value;

	return 0;

}

static int rds_cong_monitor(struct rds_sock *rs, char __user *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_setsockopt(struct socket *sock, int level, int optname,

			  char __user *optval, 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_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;

	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;

	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;

	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 sockaddr_in *)uaddr;

	struct rds_sock *rs = rds_sk_to_rs(sk);

	int ret = 0;

	lock_sock(sk);

	if (addr_len != sizeof(struct sockaddr_in)) {

		ret = -EINVAL;

		goto out;

	}

	if (sin->sin_family != AF_INET) {

		ret = -EAFNOSUPPORT;

		goto out;

	}

	if (sin->sin_addr.s_addr == htonl(INADDR_ANY)) {

		ret = -EDESTADDRREQ;

		goto out;

	}

	rs->rs_conn_addr = sin->sin_addr.s_addr;

	rs->rs_conn_port = sin->sin_port;

out:

	release_sock(sk);

	return ret;

}

static struct proto rds_proto = {

	.name	  = "RDS",

	.owner	  = THIS_MODULE,

	.obj_size = sizeof(struct rds_sock),

};

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

{

	unsigned long flags;

	struct rds_sock *rs;

	sock_init_data(sock, sk);

	sock->ops		= &rds_proto_ops;

	sk->sk_protocol		= protocol;

	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);

	spin_lock_init(&rs->rs_rdma_lock);

	rs->rs_rdma_keys = RB_ROOT;

	spin_lock_irqsave(&rds_sock_lock, flags);

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

	rds_sock_count++;

	spin_unlock_irqrestore(&rds_sock_lock, flags);

	return 0;

}

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

{

	struct sock *sk;

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

		return -ESOCKTNOSUPPORT;

	sk = sk_alloc(net, AF_RDS, GFP_ATOMIC, &rds_proto);

	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 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 sock *sk;

	struct rds_incoming *inc;

	unsigned long flags;

	unsigned int total = 0;

	len /= sizeof(struct rds_info_message);

	spin_lock_irqsave(&rds_sock_lock, flags);

	list_for_each_entry(rs, &rds_sock_list, rs_item) {

		sk = rds_rs_to_sk(rs);

		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,

						  rs->rs_bound_addr, 1);

		}

		read_unlock(&rs->rs_recv_lock);

	}

	spin_unlock_irqrestore(&rds_sock_lock, flags);

	lens->nr = total;

	lens->each = sizeof(struct rds_info_message);

}

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;

	struct rds_sock *rs;

	unsigned long flags;

	len /= sizeof(struct rds_info_socket);

	spin_lock_irqsave(&rds_sock_lock, flags);

	if (len < rds_sock_count)

		goto out;

	list_for_each_entry(rs, &rds_sock_list, rs_item) {

		sinfo.sndbuf = rds_sk_sndbuf(rs);

		sinfo.rcvbuf = rds_sk_rcvbuf(rs);

		sinfo.bound_addr = rs->rs_bound_addr;

		sinfo.connected_addr = rs->rs_conn_addr;

		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));

	}

out:

	lens->nr = rds_sock_count;

	lens->each = sizeof(struct rds_info_socket);

	spin_unlock_irqrestore(&rds_sock_lock, flags);

}

static void __exit rds_exit(void)

{

	rds_rdma_exit();

	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_info_deregister_func(RDS_INFO_SOCKETS, rds_sock_info);

	rds_info_deregister_func(RDS_INFO_RECV_MESSAGES, rds_sock_inc_info);

}

module_exit(rds_exit);

static int __init rds_init(void)

{

	int ret;

	ret = rds_conn_init();

	if (ret)

		goto out;

	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);

	/* ib/iwarp transports currently compiled-in */

	ret = rds_rdma_init();

	if (ret)

		goto out_sock;

	goto out;

out_sock:

	sock_unregister(rds_family_ops.family);

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:

	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);

/*

 * Copyright (c) 2006 Oracle.  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/kernel.h>

#include <net/sock.h>

#include <linux/in.h>

#include <linux/if_arp.h>

#include "rds.h"

/*

 * XXX this probably still needs more work.. no INADDR_ANY, and rbtrees aren't

 * particularly zippy.

 *

 * This is now called for every incoming frame so we arguably care much more

 * about it than we used to.

 */

static DEFINE_SPINLOCK(rds_bind_lock);

static struct rb_root rds_bind_tree = RB_ROOT;

static struct rds_sock *rds_bind_tree_walk(__be32 addr, __be16 port,

					   struct rds_sock *insert)

{

	struct rb_node **p = &rds_bind_tree.rb_node;

	struct rb_node *parent = NULL;

	struct rds_sock *rs;

	u64 cmp;

	u64 needle = ((u64)be32_to_cpu(addr) << 32) | be16_to_cpu(port);

	while (*p) {

		parent = *p;

		rs = rb_entry(parent, struct rds_sock, rs_bound_node);

		cmp = ((u64)be32_to_cpu(rs->rs_bound_addr) << 32) |

		      be16_to_cpu(rs->rs_bound_port);

		if (needle < cmp)

			p = &(*p)->rb_left;

		else if (needle > cmp)

			p = &(*p)->rb_right;

		else

			return rs;

	}

	if (insert) {

		rb_link_node(&insert->rs_bound_node, parent, p);

		rb_insert_color(&insert->rs_bound_node, &rds_bind_tree);

	}

	return NULL;

}

/*

 * Return the rds_sock bound at the given local address.

 *

 * The rx path can race with rds_release.  We notice if rds_release() has

 * marked this socket and don't return a rs ref to the rx path.

 */

struct rds_sock *rds_find_bound(__be32 addr, __be16 port)

{

	struct rds_sock *rs;

	unsigned long flags;

	spin_lock_irqsave(&rds_bind_lock, flags);

	rs = rds_bind_tree_walk(addr, port, NULL);

	if (rs && !sock_flag(rds_rs_to_sk(rs), SOCK_DEAD))

		rds_sock_addref(rs);

	else

		rs = NULL;

	spin_unlock_irqrestore(&rds_bind_lock, flags);

	rdsdebug("returning rs %p for %pI4:%u\n", rs, &addr,

		ntohs(port));

	return rs;

}

/* returns -ve errno or +ve port */

static int rds_add_bound(struct rds_sock *rs, __be32 addr, __be16 *port)

{

	unsigned long flags;

	int ret = -EADDRINUSE;

	u16 rover, last;

	if (*port != 0) {

		rover = be16_to_cpu(*port);

		last = rover;

	} else {

		rover = max_t(u16, net_random(), 2);

		last = rover - 1;

	}

	spin_lock_irqsave(&rds_bind_lock, flags);

	do {

		if (rover == 0)

			rover++;

		if (rds_bind_tree_walk(addr, cpu_to_be16(rover), rs) == NULL) {

			*port = cpu_to_be16(rover);

			ret = 0;

			break;

		}

	} while (rover++ != last);

	if (ret == 0)  {

		rs->rs_bound_addr = addr;

		rs->rs_bound_port = *port;

		rds_sock_addref(rs);

		rdsdebug("rs %p binding to %pI4:%d\n",

		  rs, &addr, (int)ntohs(*port));

	}

	spin_unlock_irqrestore(&rds_bind_lock, flags);