/* * 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 1024static 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, net_random(), 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; 	trans = rds_trans_get_preferred(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;}