litmus-rt.git - The LITMUS^RT kernel.

/* SCTP kernel implementation
 * (C) Copyright IBM Corp. 2001, 2003
 * Copyright (c) Cisco 1999,2000
 * Copyright (c) Motorola 1999,2000,2001
 * Copyright (c) La Monte H.P. Yarroll 2001
 *
 * This file is part of the SCTP kernel implementation.
 *
 * A collection class to handle the storage of transport addresses.
 *
 * This SCTP implementation is free software;
 * you can redistribute it and/or modify it under the terms of
 * the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This SCTP implementation is distributed in the hope that it
 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
 *                 ************************
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GNU CC; see the file COPYING.  If not, write to
 * the Free Software Foundation, 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * Please send any bug reports or fixes you make to the
 * email address(es):
 *    lksctp developers <linux-sctp@vger.kernel.org>
 *
 * Written or modified by:
 *    La Monte H.P. Yarroll <piggy@acm.org>
 *    Karl Knutson          <karl@athena.chicago.il.us>
 *    Jon Grimm             <jgrimm@us.ibm.com>
 *    Daisy Chang           <daisyc@us.ibm.com>
 */

#include <linux/types.h>
#include <linux/slab.h>
#include <linux/in.h>
#include <net/sock.h>
#include <net/ipv6.h>
#include <net/if_inet6.h>
#include <net/sctp/sctp.h>
#include <net/sctp/sm.h>

/* Forward declarations for internal helpers. */
static int sctp_copy_one_addr(struct net *, struct sctp_bind_addr *,
			      union sctp_addr *, sctp_scope_t scope, gfp_t gfp,
			      int flags);
static void sctp_bind_addr_clean(struct sctp_bind_addr *);

/* First Level Abstractions. */

/* Copy 'src' to 'dest' taking 'scope' into account.  Omit addresses
 * in 'src' which have a broader scope than 'scope'.
 */
int sctp_bind_addr_copy(struct net *net, struct sctp_bind_addr *dest,
			const struct sctp_bind_addr *src,
			sctp_scope_t scope, gfp_t gfp,
			int flags)
{
	struct sctp_sockaddr_entry *addr;
	int error = 0;

	/* All addresses share the same port.  */
	dest->port = src->port;

	/* Extract the addresses which are relevant for this scope.  */
	list_for_each_entry(addr, &src->address_list, list) {
		error = sctp_copy_one_addr(net, dest, &addr->a, scope,
					   gfp, flags);
		if (error < 0)
			goto out;
	}

	/* If there are no addresses matching the scope and
	 * this is global scope, try to get a link scope address, with
	 * the assumption that we must be sitting behind a NAT.
	 */
	if (list_empty(&dest->address_list) && (SCTP_SCOPE_GLOBAL == scope)) {
		list_for_each_entry(addr, &src->address_list, list) {
			error = sctp_copy_one_addr(net, dest, &addr->a,
						   SCTP_SCOPE_LINK, gfp,
						   flags);
			if (error < 0)
				goto out;
		}
	}

out:
	if (error)
		sctp_bind_addr_clean(dest);

	return error;
}

/* Exactly duplicate the address lists.  This is necessary when doing
 * peer-offs and accepts.  We don't want to put all the current system
 * addresses into the endpoint.  That's useless.  But we do want duplicat
 * the list of bound addresses that the older endpoint used.
 */
int sctp_bind_addr_dup(struct sctp_bind_addr *dest,
			const struct sctp_bind_addr *src,
			gfp_t gfp)
{
	struct sctp_sockaddr_entry *addr;
	int error = 0;

	/* All addresses share the same port.  */
	dest->port = src->port;

	list_for_each_entry(addr, &src->address_list, list) {
		error = sctp_add_bind_addr(dest, &addr->a, 1, gfp);
		if (error < 0)
			break;
	}

	return error;
}

/* Initialize the SCTP_bind_addr structure for either an endpoint or
 * an association.
 */
void sctp_bind_addr_init(struct sctp_bind_addr *bp, __u16 port)
{
	INIT_LIST_HEAD(&bp->address_list);
	bp->port = port;
}

/* Dispose of the address list. */
static void sctp_bind_addr_clean(struct sctp_bind_addr *bp)
{
	struct sctp_sockaddr_entry *addr, *temp;

	/* Empty the bind address list. */
	list_for_each_entry_safe(addr, temp, &bp->address_list, list) {
		list_del_rcu(&addr->list);
		kfree_rcu(addr, rcu);
		SCTP_DBG_OBJCNT_DEC(addr);
	}
}

/* Dispose of an SCTP_bind_addr structure  */
void sctp_bind_addr_free(struct sctp_bind_addr *bp)
{
	/* Empty the bind address list. */
	sctp_bind_addr_clean(bp);
}

/* Add an address to the bind address list in the SCTP_bind_addr structure. */
int sctp_add_bind_addr(struct sctp_bind_addr *bp, union sctp_addr *new,
		       __u8 addr_state, gfp_t gfp)
{
	struct sctp_sockaddr_entry *addr;


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