net/tipc/msg.h

/*
 * net/tipc/msg.h: Include file for TIPC message header routines
 * 
 * Copyright (c) 2003-2005, Ericsson Research Canada
 * Copyright (c) 2005, Wind River Systems
 * Copyright (c) 2005-2006, Ericsson AB
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. Neither the names of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef _TIPC_MSG_H
#define _TIPC_MSG_H

#include <net/tipc/tipc_msg.h>

#define TIPC_VERSION              2
#define DATA_LOW                  TIPC_LOW_IMPORTANCE
#define DATA_MEDIUM               TIPC_MEDIUM_IMPORTANCE
#define DATA_HIGH                 TIPC_HIGH_IMPORTANCE
#define DATA_CRITICAL             TIPC_CRITICAL_IMPORTANCE
#define SHORT_H_SIZE              24	/* Connected,in cluster */
#define DIR_MSG_H_SIZE            32	/* Directly addressed messages */
#define CONN_MSG_H_SIZE           36	/* Routed connected msgs*/
#define LONG_H_SIZE               40	/* Named Messages */
#define MCAST_H_SIZE              44	/* Multicast messages */
#define MAX_H_SIZE                60	/* Inclusive full options */
#define MAX_MSG_SIZE (MAX_H_SIZE + TIPC_MAX_USER_MSG_SIZE)
#define LINK_CONFIG               13


/*
		TIPC user data message header format, version 2
		
	- Fundamental definitions available to privileged TIPC users
	  are located in tipc_msg.h.
	- Remaining definitions available to TIPC internal users appear below. 
*/


static inline void msg_set_word(struct tipc_msg *m, u32 w, u32 val)
{
	m->hdr[w] = htonl(val);
}

static inline void msg_set_bits(struct tipc_msg *m, u32 w,
				u32 pos, u32 mask, u32 val)
{
	u32 word = msg_word(m,w) & ~(mask << pos);
	msg_set_word(m, w, (word |= (val << pos)));
}

/* 
 * Word 0
 */

static inline u32 msg_version(struct tipc_msg *m)
{
	return msg_bits(m, 0, 29, 7);
}

static inline void msg_set_version(struct tipc_msg *m) 
{
	msg_set_bits(m, 0, 29, 0xf, TIPC_VERSION);
}

static inline u32 msg_user(struct tipc_msg *m)
{
	return msg_bits(m, 0, 25, 0xf);
}

static inline u32 msg_isdata(struct tipc_msg *m)
{
	return (msg_user(m) <= DATA_CRITICAL);
}

static inline void msg_set_user(struct tipc_msg *m, u32 n) 
{
	msg_set_bits(m, 0, 25, 0xf, n);
}

static inline void msg_set_importance(struct tipc_msg *m, u32 i) 
{
	msg_set_user(m, i);
}

static inline void msg_set_hdr_sz(struct tipc_msg *m,u32 n) 
{
	msg_set_bits(m, 0, 21, 0xf, n>>2);
}

static inline int msg_non_seq(struct tipc_msg *m) 
{
	return msg_bits(m, 0, 20, 1);
}

static inline void msg_set_non_seq(struct tipc_msg *m) 
{
	msg_set_bits(m, 0, 20, 1, 1);
}

static inline int msg_dest_droppable(struct tipc_msg *m) 
{
	return msg_bits(m, 0, 19, 1);
}

static inline void msg_set_dest_droppable(struct tipc_msg *m, u32 d) 
{
	msg_set_bits(m, 0, 19, 1, d);
}

static inline int msg_src_droppable(struct tipc_msg *m) 
{
	return msg_bits(m, 0, 18, 1);
}

static inline void msg_set_src_droppable(struct tipc_msg *m, u32 d) 
{
	msg_set_bits(m, 0, 18, 1, d);
}

static inline void msg_set_size(struct tipc_msg *m, u32 sz)
{
	m->hdr[0] = htonl((msg_word(m, 0) & ~0x1ffff) | sz);
}


/* 
 * Word 1
 */

static inline void msg_set_type(struct tipc_msg *m, u32 n) 
{
	msg_set_bits(m, 1, 29, 0x7, n);
}

static inline void msg_set_errcode(struct tipc_msg *m, u32 err) 
{
	msg_set_bits(m, 1, 25, 0xf, err);
}

static inline u32 msg_reroute_cnt(struct tipc_msg *m) 
{
	return msg_bits(m, 1, 21, 0xf);
}

static inline void msg_incr_reroute_cnt(struct tipc_msg *m) 
{
	msg_set_bits(m, 1, 21, 0xf, msg_reroute_cnt(m) + 1);
}

static inline void msg_reset_reroute_cnt(struct tipc_msg *m) 
{
	msg_set_bits(m, 1, 21, 0xf, 0);
}

static inline u32 msg_lookup_scope(struct tipc_msg *m)
{
	return msg_bits(m, 1, 19, 0x3);
}

static inline void msg_set_lookup_scope(struct tipc_msg *m, u32 n) 
{
	msg_set_bits(m, 1, 19, 0x3, n);
}

static inline void msg_set_options(struct tipc_msg *m, const char *opt, u32 sz) 
{
	u32 hsz = msg_hdr_sz(m);
	char *to = (char *)&m->hdr[hsz/4];

	if ((hsz < DIR_MSG_H_SIZE) || ((hsz + sz) > MAX_H_SIZE))
		return;
	msg_set_bits(m, 1, 16, 0x7, (hsz - 28)/4);
	msg_set_hdr_sz(m, hsz + sz);
	memcpy(to, opt, sz);
}

static inline u32 msg_bcast_ack(struct tipc_msg *m)
{
	return msg_bits(m, 1, 0, 0xffff);
}

static inline void msg_set_bcast_ack(struct tipc_msg *m, u32 n) 
{
	msg_set_bits(m, 1, 0, 0xffff, n);
}


/* 
 * Word 2
 */

static inline u32 msg_ack(struct tipc_msg *m)
{
	return msg_bits(m, 2, 16, 0xffff);
}

static inline void msg_set_ack(struct tipc_msg *m, u32 n) 
{
	msg_set_bits(m, 2, 16, 0xffff, n);
}

static inline u32 msg_seqno(struct tipc_msg *m)
{
	return msg_bits(m, 2, 0, 0xffff);
}

static inline void msg_set_seqno(struct tipc_msg *m, u32 n) 
{
	msg_set_bits(m, 2, 0, 0xffff, n);
}


/* 
 * Words 3-10
 */


static inline void msg_set_prevnode(struct tipc_msg *m, u32 a) 
{
	msg_set_word(m, 3, a);
}

static inline void msg_set_origport(struct tipc_msg *m, u32 p) 
{
	msg_set_word(m, 4, p);
}

static inline void msg_set_destport(struct tipc_msg *m, u32 p) 
{
	msg_set_word(m, 5, p);
}

static inline void msg_set_mc_netid(struct tipc_msg *m, u32 p) 
{
	msg_set_word(m, 5, p);
}

static inline void msg_set_orignode(struct tipc_msg *m, u32 a) 
{
	msg_set_word(m, 6, a);
}

static inline void msg_set_destnode(struct tipc_msg *m, u32 a) 
{
	msg_set_word(m, 7, a);
}

static inline int msg_is_dest(struct tipc_msg *m, u32 d) 
{
	return(msg_short(m) || (msg_destnode(m) == d));
}

static inline u32 msg_routed(struct tipc_msg *m)
{
	if (likely(msg_short(m)))
		return 0;
	return(msg_destnode(m) ^ msg_orignode(m)) >> 11;
}

static inline void msg_set_nametype(struct tipc_msg *m, u32 n) 
{
	msg_set_word(m, 8, n);
}

static inline u32 msg_transp_seqno(struct tipc_msg *m)
{
	return msg_word(m, 8);
}

static inline void msg_set_timestamp(struct tipc_msg *m, u32 n)
{
	msg_set_word(m, 8, n);
}

static inline u32 msg_timestamp(struct tipc_msg *m)
{
	return msg_word(m, 8);
}

static inline void msg_set_transp_seqno(struct tipc_msg *m, u32 n)
{
	msg_set_word(m, 8, n);
}

static inline void msg_set_namelower(struct tipc_msg *m, u32 n) 
{
	msg_set_word(m, 9, n);
}

static inline void msg_set_nameinst(struct tipc_msg *m, u32 n) 
{
	msg_set_namelower(m, n);
}

static inline void msg_set_nameupper(struct tipc_msg *m, u32 n) 
{
	msg_set_word(m, 10, n);
}

static inline struct tipc_msg *msg_get_wrapped(struct tipc_msg *m)
{
	return (struct tipc_msg *)msg_data(m);
}

static inline void msg_expand(struct tipc_msg *m, u32 destnode) 
{
	if (!msg_short(m))
		return;
	msg_set_hdr_sz(m, LONG_H_SIZE);
	msg_set_orignode(m, msg_prevnode(m));
	msg_set_destnode(m, destnode);
	memset(&m->hdr[8], 0, 12);
}



/*
		TIPC internal message header format, version 2

       1 0 9 8 7 6 5 4|3 2 1 0 9 8 7 6|5 4 3 2 1 0 9 8|7 6 5 4 3 2 1 0 
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   w0:|vers |msg usr|hdr sz |n|resrv|            packet size          |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   w1:|m typ|rsv=0|   sequence gap    |       broadcast ack no        |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   w2:| link level ack no/bc_gap_from |     seq no / bcast_gap_to     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   w3:|                       previous node                           |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   w4:|  next sent broadcast/fragm no | next sent pkt/ fragm msg no   |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   w5:|          session no           |rsv=0|r|berid|link prio|netpl|p|
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   w6:|                      originating node                         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   w7:|                      destination node                         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   w8:|                   transport sequence number                   |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
   w9:|   msg count / bcast tag       |       link tolerance          |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      \                                                               \
      /                     User Specific Data                        /
      \                                                               \
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

      NB: CONN_MANAGER use data message format. LINK_CONFIG has own format.
*/   

/* 
 * Internal users
 */

#define  BCAST_PROTOCOL       5
#define  MSG_BUNDLER          6
#define  LINK_PROTOCOL        7
#define  CONN_MANAGER         8
#define  ROUTE_DISTRIBUTOR    9
#define  CHANGEOVER_PROTOCOL  10
#define  NAME_DISTRIBUTOR     11
#define  MSG_FRAGMENTER       12
#define  LINK_CONFIG          13
#define  INT_H_SIZE           40
#define  DSC_H_SIZE           40

/* 
 *  Connection management protocol messages
 */

#define CONN_PROBE        0
#define CONN_PROBE_REPLY  1
#define CONN_ACK          2

/* 
 * Name distributor messages
 */

#define PUBLICATION       0
#define WITHDRAWAL        1


/* 
 * Word 1
 */

static inline u32 msg_seq_gap(struct tipc_msg *m)
{
	return msg_bits(m, 1, 16, 0xff);
}

static inline void msg_set_seq_gap(struct tipc_msg *m, u32 n)
{
	msg_set_bits(m, 1, 16, 0xff, n);
}

static inline u32 msg_req_links(struct tipc_msg *m)
{
	return msg_bits(m, 1, 16, 0xfff);
}

static inline void msg_set_req_links(struct tipc_msg *m, u32 n) 
{
	msg_set_bits(m, 1, 16, 0xfff, n);
}


/* 
 * Word 2
 */

static inline u32 msg_dest_domain(struct tipc_msg *m)
{
	return msg_word(m, 2);
}

static inline void msg_set_dest_domain(struct tipc_msg *m, u32 n) 
{
	msg_set_word(m, 2, n);
}

static inline u32 msg_bcgap_after(struct tipc_msg *m)
{
	return msg_bits(m, 2, 16, 0xffff);
}

static inline void msg_set_bcgap_after(struct tipc_msg *m, u32 n)
{
	msg_set_bits(m, 2, 16, 0xffff, n);
}

static inline u32 msg_bcgap_to(struct tipc_msg *m)
{
	return msg_bits(m, 2, 0, 0xffff);
}

static inline void msg_set_bcgap_to(struct tipc_msg *m, u32 n) 
{
	msg_set_bits(m, 2, 0, 0xffff, n);
}


/* 
 * Word 4
 */

static inline u32 msg_last_bcast(struct tipc_msg *m)
{
	return msg_bits(m, 4, 16, 0xffff);
}

static inline void msg_set_last_bcast(struct tipc_msg *m, u32 n)
{
	msg_set_bits(m, 4, 16, 0xffff, n);
}


static inline u32 msg_fragm_no(struct tipc_msg *m)
{
	return msg_bits(m, 4, 16, 0xffff);
}

static inline void msg_set_fragm_no(struct tipc_msg *m, u32 n)
{
	msg_set_bits(m, 4, 16, 0xffff, n);
}


static inline u32 msg_next_sent(struct tipc_msg *m)
{
	return msg_bits(m, 4, 0, 0xffff);
}

static inline void msg_set_next_sent(struct tipc_msg *m, u32 n)
{
	msg_set_bits(m, 4, 0, 0xffff, n);
}


static inline u32 msg_long_msgno(struct tipc_msg *m)
{
	return msg_bits(m, 4, 0, 0xffff);
}

static inline void msg_set_long_msgno(struct tipc_msg *m, u32 n)
{
	msg_set_bits(m, 4, 0, 0xffff, n);
}

static inline u32 msg_bc_netid(struct tipc_msg *m)
{
	return msg_word(m, 4);
}

static inline void msg_set_bc_netid(struct tipc_msg *m, u32 id)
{
	msg_set_word(m, 4, id);
}

static inline u32 msg_link_selector(struct tipc_msg *m)
{
	return msg_bits(m, 4, 0, 1);
}

static inline void msg_set_link_selector(struct tipc_msg *m, u32 n)
{
	msg_set_bits(m, 4, 0, 1, (n & 1));
}

/* 
 * Word 5
 */

static inline u32 msg_session(struct tipc_msg *m)
{
	return msg_bits(m, 5, 16, 0xffff);
}

static inline void msg_set_session(struct tipc_msg *m, u32 n)
{
	msg_set_bits(m, 5, 16, 0xffff, n);
}

static inline u32 msg_probe(struct tipc_msg *m)
{
	return msg_bits(m, 5, 0, 1);
}

static inline void msg_set_probe(struct tipc_msg *m, u32 val)
{
	msg_set_bits(m, 5, 0, 1, (val & 1));
}

static inline char msg_net_plane(struct tipc_msg *m)
{
	return msg_bits(m, 5, 1, 7) + 'A';
}

static inline void msg_set_net_plane(struct tipc_msg *m, char n)
{
	msg_set_bits(m, 5, 1, 7, (n - 'A'));
}

static inline u32 msg_linkprio(struct tipc_msg *m)
{
	return msg_bits(m, 5, 4, 0x1f);
}

static inline void msg_set_linkprio(struct tipc_msg *m, u32 n)
{
	msg_set_bits(m, 5, 4, 0x1f, n);
}

static inline u32 msg_bearer_id(struct tipc_msg *m)
{
	return msg_bits(m, 5, 9, 0x7);
}

static inline void msg_set_bearer_id(struct tipc_msg *m, u32 n)
{
	msg_set_bits(m, 5, 9, 0x7, n);
}

static inline u32 msg_redundant_link(struct tipc_msg *m)
{
	return msg_bits(m, 5, 12, 0x1);
}

static inline void msg_set_redundant_link(struct tipc_msg *m)
{
	msg_set_bits(m, 5, 12, 0x1, 1);
}

static inline void msg_clear_redundant_link(struct tipc_msg *m)
{
	msg_set_bits(m, 5, 12, 0x1, 0);
}


/* 
 * Word 9
 */

static inline u32 msg_msgcnt(struct tipc_msg *m)
{
	return msg_bits(m, 9, 16, 0xffff);
}

static inline void msg_set_msgcnt(struct tipc_msg *m, u32 n)
{
	msg_set_bits(m, 9, 16, 0xffff, n);
}

static inline u32 msg_bcast_tag(struct tipc_msg *m)
{
	return msg_bits(m, 9, 16, 0xffff);
}

static inline void msg_set_bcast_tag(struct tipc_msg *m, u32 n)
{
	msg_set_bits(m, 9, 16, 0xffff, n);
}

static inline u32 msg_max_pkt(struct tipc_msg *m) 
{
	return (msg_bits(m, 9, 16, 0xffff) * 4);
}

static inline void msg_set_max_pkt(struct tipc_msg *m, u32 n) 
{
	msg_set_bits(m, 9, 16, 0xffff, (n / 4));
}

static inline u32 msg_link_tolerance(struct tipc_msg *m)
{
	return msg_bits(m, 9, 0, 0xffff);
}

static inline void msg_set_link_tolerance(struct tipc_msg *m, u32 n)
{
	msg_set_bits(m, 9, 0, 0xffff, n);
}

/* 
 * Routing table message data
 */


static inline u32 msg_remote_node(struct tipc_msg *m)
{
	return msg_word(m, msg_hdr_sz(m)/4);
}

static inline void msg_set_remote_node(struct tipc_msg *m, u32 a)
{
	msg_set_word(m, msg_hdr_sz(m)/4, a);
}

static inline int msg_dataoctet(struct tipc_msg *m, u32 pos)
{
	return(msg_data(m)[pos + 4] != 0);
}

static inline void msg_set_dataoctet(struct tipc_msg *m, u32 pos)
{
	msg_data(m)[pos + 4] = 1;
}

/* 
 * Segmentation message types
 */

#define FIRST_FRAGMENT     0
#define FRAGMENT           1
#define LAST_FRAGMENT      2

/* 
 * Link management protocol message types
 */

#define STATE_MSG       0
#define RESET_MSG       1
#define ACTIVATE_MSG    2

/* 
 * Changeover tunnel message types
 */
#define DUPLICATE_MSG    0
#define ORIGINAL_MSG     1

/* 
 * Routing table message types
 */
#define EXT_ROUTING_TABLE    0
#define LOCAL_ROUTING_TABLE  1
#define SLAVE_ROUTING_TABLE  2
#define ROUTE_ADDITION       3
#define ROUTE_REMOVAL        4

/* 
 * Config protocol message types
 */

#define DSC_REQ_MSG          0
#define DSC_RESP_MSG         1

static inline u32 msg_tot_importance(struct tipc_msg *m)
{
	if (likely(msg_isdata(m))) {
		if (likely(msg_orignode(m) == tipc_own_addr))
			return msg_importance(m);
		return msg_importance(m) + 4;
	}
	if ((msg_user(m) == MSG_FRAGMENTER)  &&
	    (msg_type(m) == FIRST_FRAGMENT))
		return msg_importance(msg_get_wrapped(m));
	return msg_importance(m);
}


static inline void msg_init(struct tipc_msg *m, u32 user, u32 type, 
			    u32 err, u32 hsize, u32 destnode)
{
	memset(m, 0, hsize);
	msg_set_version(m);
	msg_set_user(m, user);
	msg_set_hdr_sz(m, hsize);
	msg_set_size(m, hsize);
	msg_set_prevnode(m, tipc_own_addr);
	msg_set_type(m, type);
	msg_set_errcode(m, err);
	if (!msg_short(m)) {
		msg_set_orignode(m, tipc_own_addr);
		msg_set_destnode(m, destnode);
	}
}

/** 
 * msg_calc_data_size - determine total data size for message
 */

static inline int msg_calc_data_size(struct iovec const *msg_sect, u32 num_sect)
{
	int dsz = 0;
	int i;

	for (i = 0; i < num_sect; i++)
		dsz += msg_sect[i].iov_len;
	return dsz;
}

/** 
 * msg_build - create message using specified header and data
 * 
 * Note: Caller must not hold any locks in case copy_from_user() is interrupted!
 * 
 * Returns message data size or errno
 */

static inline int msg_build(struct tipc_msg *hdr, 
			    struct iovec const *msg_sect, u32 num_sect,
			    int max_size, int usrmem, struct sk_buff** buf)
{
	int dsz, sz, hsz, pos, res, cnt;

	dsz = msg_calc_data_size(msg_sect, num_sect);
	if (unlikely(dsz > TIPC_MAX_USER_MSG_SIZE)) {
		*buf = NULL;
		return -EINVAL;
	}

	pos = hsz = msg_hdr_sz(hdr);
	sz = hsz + dsz;
	msg_set_size(hdr, sz);
	if (unlikely(sz > max_size)) {
		*buf = NULL;
		return dsz;
	}

	*buf = buf_acquire(sz);
	if (!(*buf))
		return -ENOMEM;
	memcpy((*buf)->data, (unchar *)hdr, hsz);
	for (res = 1, cnt = 0; res && (cnt < num_sect); cnt++) {
		if (likely(usrmem))
			res = !copy_from_user((*buf)->data + pos, 
					      msg_sect[cnt].iov_base, 
					      msg_sect[cnt].iov_len);
		else
			memcpy((*buf)->data + pos, msg_sect[cnt].iov_base, 
			       msg_sect[cnt].iov_len);
		pos += msg_sect[cnt].iov_len;
	}
	if (likely(res))
		return dsz;

	buf_discard(*buf);
	*buf = NULL;
	return -EFAULT;
}


struct tipc_media_addr;

extern void msg_set_media_addr(struct tipc_msg *m,
			       struct tipc_media_addr *a);

extern void msg_get_media_addr(struct tipc_msg *m,
			       struct tipc_media_addr *a);


#endif