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/*
* 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 <linux/jhash.h>
#include <linux/ratelimit.h>
#include "rds.h"
#define BIND_HASH_SIZE 1024
static struct hlist_head bind_hash_table[BIND_HASH_SIZE];
static DEFINE_SPINLOCK(rds_bind_lock);
static struct hlist_head *hash_to_bucket(__be32 addr, __be16 port)
{
return bind_hash_table + (jhash_2words((u32)addr, (u32)port, 0) &
(BIND_HASH_SIZE - 1));
}
static struct rds_sock *rds_bind_lookup(__be32 addr, __be16 port,
struct rds_sock *insert)
{
struct rds_sock *rs;
struct hlist_head *head = hash_to_bucket(addr, port);
u64 cmp;
u64 needle = ((u64)be32_to_cpu(addr) << 32) | be16_to_cpu(port);
rcu_read_lock();
hlist_for_each_entry_rcu(rs, head, rs_bound_node) {
cmp = ((u64)be32_to_cpu(rs->rs_bound_addr) << 32) |
be16_to_cpu(rs->rs_bound_port);
if (cmp == needle) {
rcu_read_unlock();
return rs;
}
}
rcu_read_unlock();
if (insert) {
/*
* make sure our addr and port are set before
* we are added to the list, other people
* in rcu will find us as soon as the
* hlist_add_head_rcu is done
*/
insert->rs_bound_addr = addr;
insert->rs_bound_port = port;
rds_sock_addref(insert);
hlist_add_head_rcu(&insert->rs_bound_node, head);
}
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;
rs = rds_bind_lookup(addr, port, NULL);
if (rs && !sock_flag(rds_rs_to_sk(rs), SOCK_DEAD))
rds_sock_addref(rs);
else
rs = NULL;
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, prandom_u32(), 2);
last = rover - 1;
}
spin_lock_irqsave(&rds_bind_lock, flags);
do {
if (rover == 0)
rover++;
if (!rds_bind_lookup(addr, cpu_to_be16(rover), rs)) {
*port = rs->rs_bound_port;
ret = 0;
rdsdebug("rs %p binding to %pI4:%d\n",
rs, &addr, (int)ntohs(*port));
break;
}
} while (rover++ != last);
spin_unlock_irqrestore(&rds_bind_lock, flags);
return ret;
}
void rds_remove_bound(struct rds_sock *rs)
{
unsigned long flags;
spin_lock_irqsave(&rds_bind_lock, flags);
if (rs->rs_bound_addr) {
rdsdebug("rs %p unbinding from %pI4:%d\n",
rs, &rs->rs_bound_addr,
ntohs(rs->rs_bound_port));
hlist_del_init_rcu(&rs->rs_bound_node);
rds_sock_put(rs);
rs->rs_bound_addr = 0;
}
spin_unlock_irqrestore(&rds_bind_lock, flags);
}
int rds_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
{
struct sock *sk = sock->sk;
struct sockaddr_in *sin = (struct sockaddr_in *)uaddr;
struct rds_sock *rs = rds_sk_to_rs(sk);
struct rds_transport *trans;
int ret = 0;
lock_sock(sk);
if (addr_len != sizeof(struct sockaddr_in) ||
sin->sin_family != AF_INET ||
rs->rs_bound_addr ||
sin->sin_addr.s_addr == htonl(INADDR_ANY)) {
ret = -EINVAL;
goto out;
}
ret = rds_add_bound(rs, sin->sin_addr.s_addr, &sin->sin_port);
if (ret)
goto out;
if (rs->rs_transport) { /* previously bound */
ret = 0;
goto out;
}
trans = rds_trans_get_preferred(sock_net(sock->sk),
sin->sin_addr.s_addr);
if (!trans) {
ret = -EADDRNOTAVAIL;
rds_remove_bound(rs);
printk_ratelimited(KERN_INFO "RDS: rds_bind() could not find a transport, "
"load rds_tcp or rds_rdma?\n");
goto out;
}
rs->rs_transport = trans;
ret = 0;
out:
release_sock(sk);
/* we might have called rds_remove_bound on error */
if (ret)
synchronize_rcu();
return ret;
}
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