linux/net/rxrpc/protocol.h

/* SPDX-License-Identifier: GPL-2.0-or-later */
/* packet.h: Rx packet layout and definitions
 *
 * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells ([email protected])
 */

#ifndef _LINUX_RXRPC_PACKET_H
#define _LINUX_RXRPC_PACKET_H

rxrpc_seq_t;	/* Rx message sequence number */
rxrpc_serial_t;	/* Rx message serial number */
rxrpc_seq_net_t; /* on-the-wire Rx message sequence number */
rxrpc_serial_net_t; /* on-the-wire Rx message serial number */

/*****************************************************************************/
/*
 * on-the-wire Rx packet header
 * - all multibyte fields should be in network byte order
 */
struct rxrpc_wire_header { … } __packed;

/*****************************************************************************/
/*
 * jumbo packet secondary header
 * - can be mapped to read header by:
 *   - new_serial = serial + 1
 *   - new_seq = seq + 1
 *   - new_flags = j_flags
 *   - new__rsvd = j__rsvd
 *   - duplicating all other fields
 */
struct rxrpc_jumbo_header { … } __packed;

#define RXRPC_JUMBO_DATALEN …
#define RXRPC_JUMBO_SUBPKTLEN …

/*
 * The maximum number of subpackets that can possibly fit in a UDP packet is:
 *
 *	((max_IP - IP_hdr - UDP_hdr) / RXRPC_JUMBO_SUBPKTLEN) + 1
 *	= ((65535 - 28 - 28) / 1416) + 1
 *	= 46 non-terminal packets and 1 terminal packet.
 */
#define RXRPC_MAX_NR_JUMBO …

/*****************************************************************************/
/*
 * on-the-wire Rx ACK packet data payload
 * - all multibyte fields should be in network byte order
 */
struct rxrpc_ackpacket { … } __packed;

/*
 * ACK packets can have a further piece of information tagged on the end
 */
struct rxrpc_acktrailer { … };

/*****************************************************************************/
/*
 * Kerberos security type-2 challenge packet
 */
struct rxkad_challenge { … } __packed;

/*****************************************************************************/
/*
 * Kerberos security type-2 response packet
 */
struct rxkad_response { … } __packed;

#endif /* _LINUX_RXRPC_PACKET_H */