path: root/net/tipc/msg.h

/*
 * 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  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 FB_MTU                  3744
#define TIPC_MEDIA_INFO_OFFSET	5

struct tipc_skb_cb {
	u32 bytes_read;
	u32 orig_member;
	struct sk_buff *tail;
	unsigned long nxt_retr;
	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];
};

/* 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
 * @gack_cnt: number of Gap ACK blocks in the record
 * @gacks: array of Gap ACK blocks
 */
struct tipc_gap_ack_blks {
	__be16 len;
	u8 gack_cnt;
	u8 reserved;
	struct tipc_gap_ack gacks[];
};

#define tipc_gap_ack_blks_sz(n) (sizeof(struct tipc_gap_ack_blks) + \
				 sizeof(struct tipc_gap_ack) * (n))

#define MAX_GAP_ACK_BLKS	32
#define MAX_GAP_ACK_BLKS_SZ	tipc_gap_ack_blks_sz(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);
}

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);
}