/*
 * net/tipc/msg.h: Include file for TIPC message header routines
 *
 * Copyright (c) 2000-2007, 2014-2017 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
#define TIPC_GRP_MEMBER_EVT     4
#define TIPC_GRP_BCAST_MSG      5
#define TIPC_GRP_MCAST_MSG      6
#define TIPC_GRP_UCAST_MSG      7

/*
 * Internal message users
 */
#define  BCAST_PROTOCOL       5
#define  MSG_BUNDLER          6
#define  LINK_PROTOCOL        7
#define  CONN_MANAGER         8
#define  GROUP_PROTOCOL       9
#define  TUNNEL_PROTOCOL      10
#define  NAME_DISTRIBUTOR     11
#define  MSG_FRAGMENTER       12
#define  LINK_CONFIG          13
#define  MSG_CRYPTO           14
#define  SOCK_WAKEUP          14       /* pseudo user */
#define  TOP_SRV              15       /* 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 GROUP_H_SIZE              44    /* Group 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

extern const int one_page_mtu;

struct tipc_skb_cb {
        union {
                struct {
                        struct sk_buff *tail;
                        unsigned long nxt_retr;
                        unsigned long retr_stamp;
                        u32 bytes_read;
                        u32 orig_member;
                        u16 chain_imp;
                        u16 ackers;
                        u16 retr_cnt;
                } __packed;
#ifdef CONFIG_TIPC_CRYPTO
                struct {
                        struct tipc_crypto *rx;
                        struct tipc_aead *last;
                        u8 recurs;
                } tx_clone_ctx __packed;
#endif
        } __packed;
        union {
                struct {
                        u8 validated:1;
#ifdef CONFIG_TIPC_CRYPTO
                        u8 encrypted:1;
                        u8 decrypted:1;
#define SKB_PROBING     1
#define SKB_GRACING     2
                        u8 xmit_type:2;
                        u8 tx_clone_deferred:1;
#endif
                };
                u8 flags;
        };
        u8 reserved;
#ifdef CONFIG_TIPC_CRYPTO
        void *crypto_ctx;
#endif
} __packed;

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

struct tipc_msg {
        __be32 hdr[15];
};

/* struct tipc_gap_ack - TIPC Gap ACK block
 * @ack: seqno of the last consecutive packet in link deferdq
 * @gap: number of gap packets since the last ack
 *
 * E.g:
 *       link deferdq: 1 2 3 4      10 11      13 14 15       20
 * --> Gap ACK blocks:      <4, 5>,   <11, 1>,      <15, 4>, <20, 0>
 */
struct tipc_gap_ack {
        __be16 ack;
        __be16 gap;
};

/* struct tipc_gap_ack_blks
 * @len: actual length of the record
 * @ugack_cnt: number of Gap ACK blocks for unicast (following the broadcast
 *             ones)
 * @start_index: starting index for "valid" broadcast Gap ACK blocks
 * @bgack_cnt: number of Gap ACK blocks for broadcast in the record
 * @gacks: array of Gap ACK blocks
 *
 *  31                       16 15                        0
 * +-------------+-------------+-------------+-------------+
 * |  bgack_cnt  |  ugack_cnt  |            len            |
 * +-------------+-------------+-------------+-------------+  -
 * |            gap            |            ack            |   |
 * +-------------+-------------+-------------+-------------+    > bc gacks
 * :                           :                           :   |
 * +-------------+-------------+-------------+-------------+  -
 * |            gap            |            ack            |   |
 * +-------------+-------------+-------------+-------------+    > uc gacks
 * :                           :                           :   |
 * +-------------+-------------+-------------+-------------+  -
 */
struct tipc_gap_ack_blks {
        __be16 len;
        union {
                u8 ugack_cnt;
                u8 start_index;
        };
        u8 bgack_cnt;
        struct tipc_gap_ack gacks[];
};

#define MAX_GAP_ACK_BLKS        128
#define MAX_GAP_ACK_BLKS_SZ     (sizeof(struct tipc_gap_ack_blks) + \
                                 sizeof(struct tipc_gap_ack) * MAX_GAP_ACK_BLKS)

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);
}

/*
 * 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_blocks(struct tipc_msg *m)
{
        return (msg_size(m) / 1024) + 1;
}

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_is_syn(struct tipc_msg *m)
{
        return msg_bits(m, 0, 17, 1);
}

static inline void msg_set_syn(struct tipc_msg *m, u32 d)
{
        msg_set_bits(m, 0, 17, 1, d);
}

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_is_keepalive(struct tipc_msg *m)
{
        return msg_bits(m, 0, 19, 1);
}

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

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

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

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

static inline bool msg_is_rcast(struct tipc_msg *m)
{
        return msg_bits(m, 0, 18, 0x1);
}

static inline void msg_set_is_rcast(struct tipc_msg *m, bool d)
{
        msg_set_bits(m, 0, 18, 0x1, 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_inner_hdr(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 int msg_in_group(struct tipc_msg *m)
{
        int mtyp = msg_type(m);

        return mtyp >= TIPC_GRP_MEMBER_EVT && mtyp <= TIPC_GRP_UCAST_MSG;
}

static inline bool msg_is_grp_evt(struct tipc_msg *m)
{
        return msg_type(m) == TIPC_GRP_MEMBER_EVT;
}

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)
{
        int mtyp = msg_type(m);

        return ((mtyp == TIPC_MCAST_MSG) || (mtyp == TIPC_GRP_BCAST_MSG) ||
                (mtyp == TIPC_GRP_MCAST_MSG));
}

static inline u32 msg_connected(struct tipc_msg *m)
{
        return msg_type(m) == TIPC_CONN_MSG;
}

static inline u32 msg_direct(struct tipc_msg *m)
{
        return msg_type(m) == TIPC_DIRECT_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 void msg_set_bulk(struct tipc_msg *m)
{
        msg_set_bits(m, 1, 28, 0x1, 1);
}

static inline u32 msg_is_bulk(struct tipc_msg *m)
{
        return msg_bits(m, 1, 28, 0x1);
}

static inline void msg_set_last_bulk(struct tipc_msg *m)
{
        msg_set_bits(m, 1, 27, 0x1, 1);
}

static inline u32 msg_is_last_bulk(struct tipc_msg *m)
{
        return msg_bits(m, 1, 27, 0x1);
}

static inline void msg_set_non_legacy(struct tipc_msg *m)
{
        msg_set_bits(m, 1, 26, 0x1, 1);
}

static inline u32 msg_is_legacy(struct tipc_msg *m)
{
        return !msg_bits(m, 1, 26, 0x1);
}

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 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);
}

/* Note: reusing bits in word 1 for ACTIVATE_MSG only, to re-synch
 * link peer session number
 */
static inline bool msg_dest_session_valid(struct tipc_msg *m)
{
        return msg_bits(m, 1, 16, 0x1);
}

static inline void msg_set_dest_session_valid(struct tipc_msg *m, bool valid)
{
        msg_set_bits(m, 1, 16, 0x1, valid);
}

static inline u16 msg_dest_session(struct tipc_msg *m)
{
        return msg_bits(m, 1, 0, 0xffff);
}

static inline void msg_set_dest_session(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\n");
}

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_inner_hdr(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 u16 msg_named_seqno(struct tipc_msg *m)
{
        return msg_bits(m, 4, 0, 0xffff);
}

static inline void msg_set_named_seqno(struct tipc_msg *m, u16 n)
{
        msg_set_bits(m, 4, 0, 0xffff, n);
}

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
#define DSC_TRIAL_MSG           2
#define DSC_TRIAL_FAIL_MSG      3

/*
 * Group protocol message types
 */
#define GRP_JOIN_MSG         0
#define GRP_LEAVE_MSG        1
#define GRP_ADV_MSG          2
#define GRP_ACK_MSG          3
#define GRP_RECLAIM_MSG      4
#define GRP_REMIT_MSG        5

/* Crypto message types */
#define KEY_DISTR_MSG           0

/*
 * 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 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 u32 msg_nof_fragms(struct tipc_msg *m)
{
        return msg_bits(m, 4, 0, 0xffff);
}

static inline void msg_set_nof_fragms(struct tipc_msg *m, u32 n)
{
        msg_set_bits(m, 4, 0, 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 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 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 u16 msg_syncpt(struct tipc_msg *m)
{
        return msg_bits(m, 9, 16, 0xffff);
}

static inline void msg_set_syncpt(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 u16 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, u16 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 u16 msg_grp_bc_syncpt(struct tipc_msg *m)
{
        return msg_bits(m, 9, 16, 0xffff);
}

static inline void msg_set_grp_bc_syncpt(struct tipc_msg *m, u16 n)
{
        msg_set_bits(m, 9, 16, 0xffff, n);
}

static inline u16 msg_grp_bc_acked(struct tipc_msg *m)
{
        return msg_bits(m, 9, 16, 0xffff);
}

static inline void msg_set_grp_bc_acked(struct tipc_msg *m, u16 n)
{
        msg_set_bits(m, 9, 16, 0xffff, n);
}

static inline u16 msg_grp_remitted(struct tipc_msg *m)
{
        return msg_bits(m, 9, 16, 0xffff);
}

static inline void msg_set_grp_remitted(struct tipc_msg *m, u16 n)
{
        msg_set_bits(m, 9, 16, 0xffff, n);
}

/* Word 10
 */
static inline u16 msg_grp_evt(struct tipc_msg *m)
{
        return msg_bits(m, 10, 0, 0x3);
}

static inline void msg_set_grp_evt(struct tipc_msg *m, int n)
{
        msg_set_bits(m, 10, 0, 0x3, n);
}

static inline u16 msg_grp_bc_ack_req(struct tipc_msg *m)
{
        return msg_bits(m, 10, 0, 0x1);
}

static inline void msg_set_grp_bc_ack_req(struct tipc_msg *m, bool n)
{
        msg_set_bits(m, 10, 0, 0x1, n);
}

static inline u16 msg_grp_bc_seqno(struct tipc_msg *m)
{
        return msg_bits(m, 10, 16, 0xffff);
}

static inline void msg_set_grp_bc_seqno(struct tipc_msg *m, u32 n)
{
        msg_set_bits(m, 10, 16, 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);
}

/* Word 13
 */
static inline void msg_set_peer_net_hash(struct tipc_msg *m, u32 n)
{
        msg_set_word(m, 13, n);
}

static inline u32 msg_peer_net_hash(struct tipc_msg *m)
{
        return msg_word(m, 13);
}

/* Word 14
 */
static inline u32 msg_sugg_node_addr(struct tipc_msg *m)
{
        return msg_word(m, 14);
}

static inline void msg_set_sugg_node_addr(struct tipc_msg *m, u32 n)
{
        msg_set_word(m, 14, n);
}

static inline void msg_set_node_id(struct tipc_msg *hdr, u8 *id)
{
        memcpy(msg_data(hdr), id, 16);
}

static inline u8 *msg_node_id(struct tipc_msg *hdr)
{
        return (u8 *)msg_data(hdr);
}

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_skb_reject(struct net *net, int err, struct sk_buff *skb,
                     struct sk_buff_head *xmitq);
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_try_bundle(struct sk_buff *tskb, struct sk_buff **skb, u32 mss,
                         u32 dnode, bool *new_bundle);
bool tipc_msg_extract(struct sk_buff *skb, struct sk_buff **iskb, int *pos);
int tipc_msg_fragment(struct sk_buff *skb, const struct tipc_msg *hdr,
                      int pktmax, struct sk_buff_head *frags);
int tipc_msg_build(struct tipc_msg *mhdr, struct msghdr *m,
                   int offset, int dsz, int mtu, struct sk_buff_head *list);
int tipc_msg_append(struct tipc_msg *hdr, struct msghdr *m, int dlen,
                    int mss, struct sk_buff_head *txq);
bool tipc_msg_lookup_dest(struct net *net, struct sk_buff *skb, int *err);
bool tipc_msg_assemble(struct sk_buff_head *list);
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);
bool __tipc_skb_queue_sorted(struct sk_buff_head *list, u16 seqno,
                             struct sk_buff *skb);
bool tipc_msg_skb_clone(struct sk_buff_head *msg, struct sk_buff_head *cpy);

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

static inline int buf_roundup_len(struct sk_buff *skb)
{
        return (skb->len / 1024 + 1) * 1024;
}

/* 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);
}

/* __tipc_skb_dequeue() - dequeue the head skb according to expected seqno
 * @list: list to be dequeued from
 * @seqno: seqno of the expected msg
 *
 * returns skb dequeued from the list if its seqno is less than or equal to
 * the expected one, otherwise the skb is still hold
 *
 * Note: must be used with appropriate locks held only
 */
static inline struct sk_buff *__tipc_skb_dequeue(struct sk_buff_head *list,
                                                 u16 seqno)
{
        struct sk_buff *skb = skb_peek(list);

        if (skb && less_eq(buf_seqno(skb), seqno)) {
                __skb_unlink(skb, list);
                return skb;
        }
        return NULL;
}

#endif