protocol.h

  1/* SPDX-License-Identifier: GPL-2.0-or-later */
  2/* packet.h: Rx packet layout and definitions
  3 *
  4 * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved.
  5 * Written by David Howells (dhowells@redhat.com)
  6 */
  7
  8#ifndef _LINUX_RXRPC_PACKET_H
  9#define _LINUX_RXRPC_PACKET_H
 10
 11typedef u32	rxrpc_seq_t;	/* Rx message sequence number */
 12typedef u32	rxrpc_serial_t;	/* Rx message serial number */
 13typedef __be32	rxrpc_seq_net_t; /* on-the-wire Rx message sequence number */
 14typedef __be32	rxrpc_serial_net_t; /* on-the-wire Rx message serial number */
 15
 16/*****************************************************************************/
 17/*
 18 * on-the-wire Rx packet header
 19 * - all multibyte fields should be in network byte order
 20 */
 21struct rxrpc_wire_header {
 22	__be32		epoch;		/* client boot timestamp */
 23#define RXRPC_RANDOM_EPOCH	0x80000000	/* Random if set, date-based if not */
 24
 25	__be32		cid;		/* connection and channel ID */
 26#define RXRPC_MAXCALLS		4			/* max active calls per conn */
 27#define RXRPC_CHANNELMASK	(RXRPC_MAXCALLS-1)	/* mask for channel ID */
 28#define RXRPC_CIDMASK		(~RXRPC_CHANNELMASK)	/* mask for connection ID */
 29#define RXRPC_CIDSHIFT		ilog2(RXRPC_MAXCALLS)	/* shift for connection ID */
 30#define RXRPC_CID_INC		(1 << RXRPC_CIDSHIFT)	/* connection ID increment */
 31
 32	__be32		callNumber;	/* call ID (0 for connection-level packets) */
 33	__be32		seq;		/* sequence number of pkt in call stream */
 34	__be32		serial;		/* serial number of pkt sent to network */
 35
 36	uint8_t		type;		/* packet type */
 37#define RXRPC_PACKET_TYPE_DATA		1	/* data */
 38#define RXRPC_PACKET_TYPE_ACK		2	/* ACK */
 39#define RXRPC_PACKET_TYPE_BUSY		3	/* call reject */
 40#define RXRPC_PACKET_TYPE_ABORT		4	/* call/connection abort */
 41#define RXRPC_PACKET_TYPE_ACKALL	5	/* ACK all outstanding packets on call */
 42#define RXRPC_PACKET_TYPE_CHALLENGE	6	/* connection security challenge (SRVR->CLNT) */
 43#define RXRPC_PACKET_TYPE_RESPONSE	7	/* connection secutity response (CLNT->SRVR) */
 44#define RXRPC_PACKET_TYPE_DEBUG		8	/* debug info request */
 45#define RXRPC_PACKET_TYPE_PARAMS	9	/* Parameter negotiation (unspec'd, ignore) */
 46#define RXRPC_PACKET_TYPE_10		10	/* Ignored */
 47#define RXRPC_PACKET_TYPE_11		11	/* Ignored */
 48#define RXRPC_PACKET_TYPE_VERSION	13	/* version string request */
 49
 50	uint8_t		flags;		/* packet flags */
 51#define RXRPC_CLIENT_INITIATED	0x01		/* signifies a packet generated by a client */
 52#define RXRPC_REQUEST_ACK	0x02		/* request an unconditional ACK of this packet */
 53#define RXRPC_LAST_PACKET	0x04		/* the last packet from this side for this call */
 54#define RXRPC_MORE_PACKETS	0x08		/* more packets to come */
 55#define RXRPC_JUMBO_PACKET	0x20		/* [DATA] this is a jumbo packet */
 56#define RXRPC_SLOW_START_OK	0x20		/* [ACK] slow start supported */
 57
 58	uint8_t		userStatus;	/* app-layer defined status */
 59#define RXRPC_USERSTATUS_SERVICE_UPGRADE 0x01	/* AuriStor service upgrade request */
 60
 61	uint8_t		securityIndex;	/* security protocol ID */
 62	union {
 63		__be16	_rsvd;		/* reserved */
 64		__be16	cksum;		/* kerberos security checksum */
 65	};
 66	__be16		serviceId;	/* service ID */
 67
 68} __packed;
 69
 70/*****************************************************************************/
 71/*
 72 * jumbo packet secondary header
 73 * - can be mapped to read header by:
 74 *   - new_serial = serial + 1
 75 *   - new_seq = seq + 1
 76 *   - new_flags = j_flags
 77 *   - new__rsvd = j__rsvd
 78 *   - duplicating all other fields
 79 */
 80struct rxrpc_jumbo_header {
 81	uint8_t		flags;		/* packet flags (as per rxrpc_header) */
 82	uint8_t		pad;
 83	union {
 84		__be16	_rsvd;		/* reserved */
 85		__be16	cksum;		/* kerberos security checksum */
 86	};
 87} __packed;
 88
 89#define RXRPC_JUMBO_DATALEN	1412	/* non-terminal jumbo packet data length */
 90#define RXRPC_JUMBO_SUBPKTLEN	(RXRPC_JUMBO_DATALEN + sizeof(struct rxrpc_jumbo_header))
 91
 92/*
 93 * The maximum number of subpackets that can possibly fit in a UDP packet is:
 94 *
 95 *	(max_UDP - wirehdr + jumbohdr) / (jumbohdr + 1412)
 96 *	= ((65535 - 28 + 4) / 1416)
 97 *	= 45 non-terminal packets and 1 terminal packet.
 98 */
 99#define RXRPC_MAX_NR_JUMBO	46
100
101/* Size of a jumbo packet with N subpackets, excluding UDP+IP */
102#define RXRPC_JUMBO(N) ((int)sizeof(struct rxrpc_wire_header) + \
103			RXRPC_JUMBO_DATALEN +				\
104			((N) - 1) * RXRPC_JUMBO_SUBPKTLEN)
105
106/*****************************************************************************/
107/*
108 * on-the-wire Rx ACK packet data payload
109 * - all multibyte fields should be in network byte order
110 */
111struct rxrpc_ackpacket {
112	__be16		bufferSpace;	/* number of packet buffers available */
113	__be16		maxSkew;	/* diff between serno being ACK'd and highest serial no
114					 * received */
115	__be32		firstPacket;	/* sequence no of first ACK'd packet in attached list */
116	__be32		previousPacket;	/* sequence no of previous packet received */
117	__be32		serial;		/* serial no of packet that prompted this ACK */
118
119	uint8_t		reason;		/* reason for ACK */
120#define RXRPC_ACK_REQUESTED		1	/* ACK was requested on packet */
121#define RXRPC_ACK_DUPLICATE		2	/* duplicate packet received */
122#define RXRPC_ACK_OUT_OF_SEQUENCE	3	/* out of sequence packet received */
123#define RXRPC_ACK_EXCEEDS_WINDOW	4	/* packet received beyond end of ACK window */
124#define RXRPC_ACK_NOSPACE		5	/* packet discarded due to lack of buffer space */
125#define RXRPC_ACK_PING			6	/* keep alive ACK */
126#define RXRPC_ACK_PING_RESPONSE		7	/* response to RXRPC_ACK_PING */
127#define RXRPC_ACK_DELAY			8	/* nothing happened since received packet */
128#define RXRPC_ACK_IDLE			9	/* ACK due to fully received ACK window */
129#define RXRPC_ACK__INVALID		10	/* Representation of invalid ACK reason */
130
131	uint8_t		nAcks;		/* number of ACKs */
132#define RXRPC_MAXACKS	255
133
134	uint8_t		acks[];		/* list of ACK/NAKs */
135#define RXRPC_ACK_TYPE_NACK		0
136#define RXRPC_ACK_TYPE_ACK		1
137
138} __packed;
139
140/*
141 * ACK packets can have a further piece of information tagged on the end
142 */
143struct rxrpc_acktrailer {
144	__be32		maxMTU;		/* maximum Rx MTU size (bytes) [AFS 3.3] */
145	__be32		ifMTU;		/* maximum interface MTU size (bytes) [AFS 3.3] */
146	__be32		rwind;		/* Rx window size (packets) [AFS 3.4] */
147	__be32		jumbo_max;	/* max packets to stick into a jumbo packet [AFS 3.5] */
148};
149
150/*****************************************************************************/
151/*
152 * Kerberos security type-2 challenge packet
153 */
154struct rxkad_challenge {
155	__be32		version;	/* version of this challenge type */
156	__be32		nonce;		/* encrypted random number */
157	__be32		min_level;	/* minimum security level */
158	__be32		__padding;	/* padding to 8-byte boundary */
159} __packed;
160
161/*****************************************************************************/
162/*
163 * Kerberos security type-2 response packet
164 */
165struct rxkad_response {
166	__be32		version;	/* version of this response type */
167	__be32		__pad;
168
169	/* encrypted bit of the response */
170	struct {
171		__be32		epoch;		/* current epoch */
172		__be32		cid;		/* parent connection ID */
173		__be32		checksum;	/* checksum */
174		__be32		securityIndex;	/* security type */
175		__be32		call_id[4];	/* encrypted call IDs */
176		__be32		inc_nonce;	/* challenge nonce + 1 */
177		__be32		level;		/* desired level */
178	} encrypted;
179
180	__be32		kvno;		/* Kerberos key version number */
181	__be32		ticket_len;	/* Kerberos ticket length  */
182} __packed;
183
184/*
185 * GSSAPI security type-4 and type-6 data header.
186 */
187struct rxgk_header {
188	__be32	epoch;
189	__be32	cid;
190	__be32	call_number;
191	__be32	seq;
192	__be32	sec_index;
193	__be32	data_len;
194} __packed;
195
196/*
197 * GSSAPI security type-4 and type-6 response packet header.
198 */
199struct rxgk_response {
200	__be64	start_time;
201	__be32	token_len;
202} __packed;
203
204#endif /* _LINUX_RXRPC_PACKET_H */