/*
   * net/tipc/msg.h: Include file for TIPC message header routines

   *

   * Copyright (c) 2000-2007, 2014-2015 Ericsson AB

   * Copyright (c) 2005-2008, 2010-2011, Wind River Systems

   * 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 <linux/tipc.h>

  #include "core.h"

  /*
   * Constants and routines used to read and write TIPC payload message headers
   *
   * Note: Some items are also used with TIPC internal message headers
   */

  #define TIPC_VERSION              2

  struct plist;

  /*

   * Payload message users are defined in TIPC's public API:
   * - TIPC_LOW_IMPORTANCE
   * - TIPC_MEDIUM_IMPORTANCE
   * - TIPC_HIGH_IMPORTANCE
   * - TIPC_CRITICAL_IMPORTANCE
   */

  #define TIPC_SYSTEM_IMPORTANCE	4

  
  /*
   * Payload message types

   */

  #define TIPC_CONN_MSG		0
  #define TIPC_MCAST_MSG		1
  #define TIPC_NAMED_MSG		2
  #define TIPC_DIRECT_MSG		3

  /*

   * Internal message users
   */
  #define  BCAST_PROTOCOL       5
  #define  MSG_BUNDLER          6
  #define  LINK_PROTOCOL        7
  #define  CONN_MANAGER         8

  #define  TUNNEL_PROTOCOL      10

  #define  NAME_DISTRIBUTOR     11
  #define  MSG_FRAGMENTER       12
  #define  LINK_CONFIG          13
  #define  SOCK_WAKEUP          14       /* pseudo user */
  
  /*

   * Message header sizes
   */

  #define SHORT_H_SIZE              24	/* In-cluster basic payload message */
  #define BASIC_H_SIZE              32	/* Basic payload message */
  #define NAMED_H_SIZE              40	/* Named payload message */
  #define MCAST_H_SIZE              44	/* Multicast payload message */

  #define INT_H_SIZE                40	/* Internal messages */
  #define MIN_H_SIZE                24	/* Smallest legal TIPC header size */
  #define MAX_H_SIZE                60	/* Largest possible TIPC header size */

  #define MAX_MSG_SIZE (MAX_H_SIZE + TIPC_MAX_USER_MSG_SIZE)

  #define TIPC_MEDIA_INFO_OFFSET	5

  struct tipc_skb_cb {

  	u32 bytes_read;

  	struct sk_buff *tail;

  	bool validated;

  	u16 chain_imp;

  	u16 ackers;

  };
  
  #define TIPC_SKB_CB(__skb) ((struct tipc_skb_cb *)&((__skb)->cb[0]))

  struct tipc_msg {
  	__be32 hdr[15];
  };

  static inline struct tipc_msg *buf_msg(struct sk_buff *skb)
  {
  	return (struct tipc_msg *)skb->data;
  }

  static inline u32 msg_word(struct tipc_msg *m, u32 pos)
  {
  	return ntohl(m->hdr[pos]);
  }

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

  static inline u32 msg_bits(struct tipc_msg *m, u32 w, u32 pos, u32 mask)
  {
  	return (msg_word(m, w) >> pos) & mask;
  }

  static inline void msg_set_bits(struct tipc_msg *m, u32 w,
  				u32 pos, u32 mask, u32 val)
  {

  	val = (val & mask) << pos;

  	mask = mask << pos;
  	m->hdr[w] &= ~htonl(mask);
  	m->hdr[w] |= htonl(val);

  }

  static inline void msg_swap_words(struct tipc_msg *msg, u32 a, u32 b)
  {
  	u32 temp = msg->hdr[a];
  
  	msg->hdr[a] = msg->hdr[b];
  	msg->hdr[b] = temp;
  }

  /*

   * 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, 7, 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) <= TIPC_CRITICAL_IMPORTANCE;

  }

  static inline void msg_set_user(struct tipc_msg *m, u32 n)

  {
  	msg_set_bits(m, 0, 25, 0xf, n);
  }

  static inline u32 msg_hdr_sz(struct tipc_msg *m)
  {
  	return msg_bits(m, 0, 21, 0xf) << 2;
  }

  static inline void msg_set_hdr_sz(struct tipc_msg *m, u32 n)

  {
  	msg_set_bits(m, 0, 21, 0xf, n>>2);
  }

  static inline u32 msg_size(struct tipc_msg *m)
  {
  	return msg_bits(m, 0, 0, 0x1ffff);
  }
  
  static inline u32 msg_data_sz(struct tipc_msg *m)
  {
  	return msg_size(m) - msg_hdr_sz(m);
  }

  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, u32 n)

  {

  	msg_set_bits(m, 0, 20, 1, n);

  }

  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);
  }

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

  /*

   * Word 1
   */

  static inline u32 msg_type(struct tipc_msg *m)
  {
  	return msg_bits(m, 1, 29, 0x7);
  }

  static inline void msg_set_type(struct tipc_msg *m, u32 n)

  {
  	msg_set_bits(m, 1, 29, 0x7, n);
  }

  static inline u32 msg_named(struct tipc_msg *m)
  {
  	return msg_type(m) == TIPC_NAMED_MSG;
  }
  
  static inline u32 msg_mcast(struct tipc_msg *m)
  {
  	return msg_type(m) == TIPC_MCAST_MSG;
  }
  
  static inline u32 msg_connected(struct tipc_msg *m)
  {
  	return msg_type(m) == TIPC_CONN_MSG;
  }
  
  static inline u32 msg_errcode(struct tipc_msg *m)
  {
  	return msg_bits(m, 1, 25, 0xf);
  }

  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 u16 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, u16 n)

  {
  	msg_set_bits(m, 1, 0, 0xffff, n);
  }

  /*

   * Word 2
   */

  static inline u16 msg_ack(struct tipc_msg *m)

  {
  	return msg_bits(m, 2, 16, 0xffff);
  }

  static inline void msg_set_ack(struct tipc_msg *m, u16 n)

  {
  	msg_set_bits(m, 2, 16, 0xffff, n);
  }

  static inline u16 msg_seqno(struct tipc_msg *m)

  {
  	return msg_bits(m, 2, 0, 0xffff);
  }

  static inline void msg_set_seqno(struct tipc_msg *m, u16 n)

  {
  	msg_set_bits(m, 2, 0, 0xffff, n);
  }

  /*

   * Words 3-10
   */

  static inline u32 msg_importance(struct tipc_msg *m)
  {

  	int usr = msg_user(m);
  
  	if (likely((usr <= TIPC_CRITICAL_IMPORTANCE) && !msg_errcode(m)))
  		return usr;
  	if ((usr == MSG_FRAGMENTER) || (usr == MSG_BUNDLER))

  		return msg_bits(m, 9, 0, 0x7);

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

  	int usr = msg_user(m);
  
  	if (likely((usr == MSG_FRAGMENTER) || (usr == MSG_BUNDLER)))

  		msg_set_bits(m, 9, 0, 0x7, i);

  	else if (i < TIPC_SYSTEM_IMPORTANCE)

  		msg_set_user(m, i);
  	else
  		pr_warn("Trying to set illegal importance in message
  ");
  }

  static inline u32 msg_prevnode(struct tipc_msg *m)
  {
  	return msg_word(m, 3);
  }

  static inline void msg_set_prevnode(struct tipc_msg *m, u32 a)

  {
  	msg_set_word(m, 3, a);
  }

  static inline u32 msg_origport(struct tipc_msg *m)
  {

  	if (msg_user(m) == MSG_FRAGMENTER)
  		m = msg_get_wrapped(m);

  	return msg_word(m, 4);
  }

  static inline void msg_set_origport(struct tipc_msg *m, u32 p)

  {
  	msg_set_word(m, 4, p);
  }

  static inline u32 msg_destport(struct tipc_msg *m)
  {
  	return msg_word(m, 5);
  }

  static inline void msg_set_destport(struct tipc_msg *m, u32 p)

  {
  	msg_set_word(m, 5, p);
  }

  static inline u32 msg_mc_netid(struct tipc_msg *m)
  {
  	return msg_word(m, 5);
  }

  static inline void msg_set_mc_netid(struct tipc_msg *m, u32 p)

  {
  	msg_set_word(m, 5, p);
  }

  static inline int msg_short(struct tipc_msg *m)
  {

  	return msg_hdr_sz(m) == SHORT_H_SIZE;

  }
  
  static inline u32 msg_orignode(struct tipc_msg *m)
  {
  	if (likely(msg_short(m)))
  		return msg_prevnode(m);
  	return msg_word(m, 6);
  }

  static inline void msg_set_orignode(struct tipc_msg *m, u32 a)

  {
  	msg_set_word(m, 6, a);
  }

  static inline u32 msg_destnode(struct tipc_msg *m)
  {
  	return msg_word(m, 7);
  }

  static inline void msg_set_destnode(struct tipc_msg *m, u32 a)

  {
  	msg_set_word(m, 7, a);
  }

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

  static inline void msg_set_nametype(struct tipc_msg *m, u32 n)

  {
  	msg_set_word(m, 8, n);
  }

  static inline u32 msg_nameinst(struct tipc_msg *m)
  {
  	return msg_word(m, 9);
  }
  
  static inline u32 msg_namelower(struct tipc_msg *m)
  {
  	return msg_nameinst(m);
  }

  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 u32 msg_nameupper(struct tipc_msg *m)
  {
  	return msg_word(m, 10);
  }

  static inline void msg_set_nameupper(struct tipc_msg *m, u32 n)

  {
  	msg_set_word(m, 10, n);
  }

  /*

   * Constants and routines used to read and write TIPC internal message headers
   */

  /*

   *  Connection management protocol message types

   */

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

  /*

   * Name distributor message types

   */

  #define PUBLICATION       0
  #define WITHDRAWAL        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 SYNCH_MSG		0
  #define FAILOVER_MSG		1

  
  /*
   * Config protocol message types
   */

  #define DSC_REQ_MSG		0
  #define DSC_RESP_MSG		1

  /*

   * Word 1
   */

  static inline u32 msg_seq_gap(struct tipc_msg *m)
  {

  	return msg_bits(m, 1, 16, 0x1fff);

  }
  
  static inline void msg_set_seq_gap(struct tipc_msg *m, u32 n)
  {

  	msg_set_bits(m, 1, 16, 0x1fff, n);

  }

  static inline u32 msg_node_sig(struct tipc_msg *m)
  {
  	return msg_bits(m, 1, 0, 0xffff);
  }
  
  static inline void msg_set_node_sig(struct tipc_msg *m, u32 n)
  {
  	msg_set_bits(m, 1, 0, 0xffff, n);
  }

  static inline u32 msg_node_capabilities(struct tipc_msg *m)
  {
  	return msg_bits(m, 1, 15, 0x1fff);
  }
  
  static inline void msg_set_node_capabilities(struct tipc_msg *m, u32 n)
  {
  	msg_set_bits(m, 1, 15, 0x1fff, 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 u32 msg_bc_snd_nxt(struct tipc_msg *m)
  {
  	return msg_last_bcast(m) + 1;
  }

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

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

  static inline u16 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, u16 n)

  {
  	msg_set_bits(m, 4, 0, 0xffff, n);
  }

  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)
  {

  	if (msg_user(m) == MSG_FRAGMENTER)
  		m = (void *)msg_data(m);

  	return msg_bits(m, 4, 0, 1);
  }

  /*

   * Word 5
   */

  static inline u16 msg_session(struct tipc_msg *m)

  {
  	return msg_bits(m, 5, 16, 0xffff);
  }

  static inline void msg_set_session(struct tipc_msg *m, u16 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);

  }
  
  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, u32 r)

  {

  	msg_set_bits(m, 5, 12, 0x1, r);

  }

  static inline u32 msg_peer_stopping(struct tipc_msg *m)
  {
  	return msg_bits(m, 5, 13, 0x1);
  }
  
  static inline void msg_set_peer_stopping(struct tipc_msg *m, u32 s)
  {
  	msg_set_bits(m, 5, 13, 0x1, s);
  }

  static inline bool msg_bc_ack_invalid(struct tipc_msg *m)
  {
  	switch (msg_user(m)) {
  	case BCAST_PROTOCOL:
  	case NAME_DISTRIBUTOR:
  	case LINK_PROTOCOL:
  		return msg_bits(m, 5, 14, 0x1);
  	default:
  		return false;
  	}
  }
  
  static inline void msg_set_bc_ack_invalid(struct tipc_msg *m, bool invalid)
  {
  	msg_set_bits(m, 5, 14, 0x1, invalid);
  }

  static inline char *msg_media_addr(struct tipc_msg *m)
  {

  	return (char *)&m->hdr[TIPC_MEDIA_INFO_OFFSET];

  }

  static inline u32 msg_bc_gap(struct tipc_msg *m)
  {
  	return msg_bits(m, 8, 0, 0x3ff);
  }
  
  static inline void msg_set_bc_gap(struct tipc_msg *m, u32 n)
  {
  	msg_set_bits(m, 8, 0, 0x3ff, n);
  }

  /*

   * Word 9
   */

  static inline u16 msg_msgcnt(struct tipc_msg *m)

  {
  	return msg_bits(m, 9, 16, 0xffff);
  }

  static inline void msg_set_msgcnt(struct tipc_msg *m, u16 n)

  {
  	msg_set_bits(m, 9, 16, 0xffff, n);
  }

  static inline u32 msg_conn_ack(struct tipc_msg *m)

  {
  	return msg_bits(m, 9, 16, 0xffff);
  }

  static inline void msg_set_conn_ack(struct tipc_msg *m, u32 n)

  {
  	msg_set_bits(m, 9, 16, 0xffff, n);
  }

  static inline u32 msg_adv_win(struct tipc_msg *m)
  {
  	return msg_bits(m, 9, 0, 0xffff);
  }
  
  static inline void msg_set_adv_win(struct tipc_msg *m, u32 n)
  {
  	msg_set_bits(m, 9, 0, 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);
  }

  static inline bool msg_peer_link_is_up(struct tipc_msg *m)

  {

  	if (likely(msg_user(m) != LINK_PROTOCOL))

  		return true;

  	if (msg_type(m) == STATE_MSG)
  		return true;
  	return false;

  }

  static inline bool msg_peer_node_is_up(struct tipc_msg *m)

  {

  	if (msg_peer_link_is_up(m))
  		return true;

  	return msg_redundant_link(m);
  }

  static inline bool msg_is_reset(struct tipc_msg *hdr)
  {
  	return (msg_user(hdr) == LINK_PROTOCOL) && (msg_type(hdr) == RESET_MSG);
  }

  struct sk_buff *tipc_buf_acquire(u32 size, gfp_t gfp);

  bool tipc_msg_validate(struct sk_buff *skb);

  bool tipc_msg_reverse(u32 own_addr, struct sk_buff **skb, int err);

  void tipc_msg_init(u32 own_addr, struct tipc_msg *m, u32 user, u32 type,

  		   u32 hsize, u32 destnode);

  struct sk_buff *tipc_msg_create(uint user, uint type, uint hdr_sz,
  				uint data_sz, u32 dnode, u32 onode,
  				u32 dport, u32 oport, int errcode);

  int tipc_buf_append(struct sk_buff **headbuf, struct sk_buff **buf);

  bool tipc_msg_bundle(struct sk_buff *skb, struct tipc_msg *msg, u32 mtu);
  bool tipc_msg_make_bundle(struct sk_buff **skb, struct tipc_msg *msg,
  			  u32 mtu, u32 dnode);

  bool tipc_msg_extract(struct sk_buff *skb, struct sk_buff **iskb, int *pos);

  int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m,

  		   int offset, int dsz, int mtu, struct sk_buff_head *list);

  bool tipc_msg_lookup_dest(struct net *net, struct sk_buff *skb, int *err);

  bool tipc_msg_reassemble(struct sk_buff_head *list, struct sk_buff_head *rcvq);

  bool tipc_msg_pskb_copy(u32 dst, struct sk_buff_head *msg,
  			struct sk_buff_head *cpy);

  void __tipc_skb_queue_sorted(struct sk_buff_head *list, u16 seqno,
  			     struct sk_buff *skb);

  static inline u16 buf_seqno(struct sk_buff *skb)
  {
  	return msg_seqno(buf_msg(skb));
  }

  /* tipc_skb_peek(): peek and reserve first buffer in list
   * @list: list to be peeked in
   * Returns pointer to first buffer in list, if any
   */
  static inline struct sk_buff *tipc_skb_peek(struct sk_buff_head *list,
  					    spinlock_t *lock)
  {
  	struct sk_buff *skb;
  
  	spin_lock_bh(lock);
  	skb = skb_peek(list);
  	if (skb)
  		skb_get(skb);
  	spin_unlock_bh(lock);
  	return skb;
  }

  /* tipc_skb_peek_port(): find a destination port, ignoring all destinations
   *                       up to and including 'filter'.
   * Note: ignoring previously tried destinations minimizes the risk of
   *       contention on the socket lock
   * @list: list to be peeked in
   * @filter: last destination to be ignored from search
   * Returns a destination port number, of applicable.
   */
  static inline u32 tipc_skb_peek_port(struct sk_buff_head *list, u32 filter)
  {
  	struct sk_buff *skb;
  	u32 dport = 0;
  	bool ignore = true;
  
  	spin_lock_bh(&list->lock);
  	skb_queue_walk(list, skb) {
  		dport = msg_destport(buf_msg(skb));
  		if (!filter || skb_queue_is_last(list, skb))
  			break;
  		if (dport == filter)
  			ignore = false;
  		else if (!ignore)
  			break;
  	}
  	spin_unlock_bh(&list->lock);
  	return dport;
  }
  
  /* tipc_skb_dequeue(): unlink first buffer with dest 'dport' from list
   * @list: list to be unlinked from
   * @dport: selection criteria for buffer to unlink
   */
  static inline struct sk_buff *tipc_skb_dequeue(struct sk_buff_head *list,
  					       u32 dport)
  {
  	struct sk_buff *_skb, *tmp, *skb = NULL;
  
  	spin_lock_bh(&list->lock);
  	skb_queue_walk_safe(list, _skb, tmp) {
  		if (msg_destport(buf_msg(_skb)) == dport) {
  			__skb_unlink(_skb, list);
  			skb = _skb;
  			break;
  		}
  	}
  	spin_unlock_bh(&list->lock);
  	return skb;
  }

  /* tipc_skb_queue_splice_tail - append an skb list to lock protected list
   * @list: the new list to append. Not lock protected
   * @head: target list. Lock protected.
   */
  static inline void tipc_skb_queue_splice_tail(struct sk_buff_head *list,
  					      struct sk_buff_head *head)
  {
  	spin_lock_bh(&head->lock);
  	skb_queue_splice_tail(list, head);
  	spin_unlock_bh(&head->lock);
  }
  
  /* tipc_skb_queue_splice_tail_init - merge two lock protected skb lists
   * @list: the new list to add. Lock protected. Will be reinitialized
   * @head: target list. Lock protected.
   */
  static inline void tipc_skb_queue_splice_tail_init(struct sk_buff_head *list,
  						   struct sk_buff_head *head)
  {
  	struct sk_buff_head tmp;
  
  	__skb_queue_head_init(&tmp);
  
  	spin_lock_bh(&list->lock);
  	skb_queue_splice_tail_init(list, &tmp);
  	spin_unlock_bh(&list->lock);
  	tipc_skb_queue_splice_tail(&tmp, head);
  }

  #endif