summaryrefslogtreecommitdiffstats
path: root/net/rxrpc/protocol.h
blob: e8ee4af43ca89b4b5d00f42baf5b3c5642b9c4b0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
/* 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 (dhowells@redhat.com)
 */

#ifndef _LINUX_RXRPC_PACKET_H
#define _LINUX_RXRPC_PACKET_H

typedef u32	rxrpc_seq_t;	/* Rx message sequence number */
typedef u32	rxrpc_serial_t;	/* Rx message serial number */
typedef __be32	rxrpc_seq_net_t; /* on-the-wire Rx message sequence number */
typedef __be32	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 {
	__be32		epoch;		/* client boot timestamp */
#define RXRPC_RANDOM_EPOCH	0x80000000	/* Random if set, date-based if not */

	__be32		cid;		/* connection and channel ID */
#define RXRPC_MAXCALLS		4			/* max active calls per conn */
#define RXRPC_CHANNELMASK	(RXRPC_MAXCALLS-1)	/* mask for channel ID */
#define RXRPC_CIDMASK		(~RXRPC_CHANNELMASK)	/* mask for connection ID */
#define RXRPC_CIDSHIFT		ilog2(RXRPC_MAXCALLS)	/* shift for connection ID */
#define RXRPC_CID_INC		(1 << RXRPC_CIDSHIFT)	/* connection ID increment */

	__be32		callNumber;	/* call ID (0 for connection-level packets) */
	__be32		seq;		/* sequence number of pkt in call stream */
	__be32		serial;		/* serial number of pkt sent to network */

	uint8_t		type;		/* packet type */
#define RXRPC_PACKET_TYPE_DATA		1	/* data */
#define RXRPC_PACKET_TYPE_ACK		2	/* ACK */
#define RXRPC_PACKET_TYPE_BUSY		3	/* call reject */
#define RXRPC_PACKET_TYPE_ABORT		4	/* call/connection abort */
#define RXRPC_PACKET_TYPE_ACKALL	5	/* ACK all outstanding packets on call */
#define RXRPC_PACKET_TYPE_CHALLENGE	6	/* connection security challenge (SRVR->CLNT) */
#define RXRPC_PACKET_TYPE_RESPONSE	7	/* connection secutity response (CLNT->SRVR) */
#define RXRPC_PACKET_TYPE_DEBUG		8	/* debug info request */
#define RXRPC_PACKET_TYPE_PARAMS	9	/* Parameter negotiation (unspec'd, ignore) */
#define RXRPC_PACKET_TYPE_10		10	/* Ignored */
#define RXRPC_PACKET_TYPE_11		11	/* Ignored */
#define RXRPC_PACKET_TYPE_VERSION	13	/* version string request */

	uint8_t		flags;		/* packet flags */
#define RXRPC_CLIENT_INITIATED	0x01		/* signifies a packet generated by a client */
#define RXRPC_REQUEST_ACK	0x02		/* request an unconditional ACK of this packet */
#define RXRPC_LAST_PACKET	0x04		/* the last packet from this side for this call */
#define RXRPC_MORE_PACKETS	0x08		/* more packets to come */
#define RXRPC_JUMBO_PACKET	0x20		/* [DATA] this is a jumbo packet */
#define RXRPC_SLOW_START_OK	0x20		/* [ACK] slow start supported */

	uint8_t		userStatus;	/* app-layer defined status */
#define RXRPC_USERSTATUS_SERVICE_UPGRADE 0x01	/* AuriStor service upgrade request */

	uint8_t		securityIndex;	/* security protocol ID */
	union {
		__be16	_rsvd;		/* reserved */
		__be16	cksum;		/* kerberos security checksum */
	};
	__be16		serviceId;	/* service ID */

} __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 {
	uint8_t		flags;		/* packet flags (as per rxrpc_header) */
	uint8_t		pad;
	union {
		__be16	_rsvd;		/* reserved */
		__be16	cksum;		/* kerberos security checksum */
	};
} __packed;

#define RXRPC_JUMBO_DATALEN	1412	/* non-terminal jumbo packet data length */
#define RXRPC_JUMBO_SUBPKTLEN	(RXRPC_JUMBO_DATALEN + sizeof(struct rxrpc_jumbo_header))

/*
 * 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	47

/*****************************************************************************/
/*
 * on-the-wire Rx ACK packet data payload
 * - all multibyte fields should be in network byte order
 */
struct rxrpc_ackpacket {
	__be16		bufferSpace;	/* number of packet buffers available */
	__be16		maxSkew;	/* diff between serno being ACK'd and highest serial no
					 * received */
	__be32		firstPacket;	/* sequence no of first ACK'd packet in attached list */
	__be32		previousPacket;	/* sequence no of previous packet received */
	__be32		serial;		/* serial no of packet that prompted this ACK */

	uint8_t		reason;		/* reason for ACK */
#define RXRPC_ACK_REQUESTED		1	/* ACK was requested on packet */
#define RXRPC_ACK_DUPLICATE		2	/* duplicate packet received */
#define RXRPC_ACK_OUT_OF_SEQUENCE	3	/* out of sequence packet received */
#define RXRPC_ACK_EXCEEDS_WINDOW	4	/* packet received beyond end of ACK window */
#define RXRPC_ACK_NOSPACE		5	/* packet discarded due to lack of buffer space */
#define RXRPC_ACK_PING			6	/* keep alive ACK */
#define RXRPC_ACK_PING_RESPONSE		7	/* response to RXRPC_ACK_PING */
#define RXRPC_ACK_DELAY			8	/* nothing happened since received packet */
#define RXRPC_ACK_IDLE			9	/* ACK due to fully received ACK window */
#define RXRPC_ACK__INVALID		10	/* Representation of invalid ACK reason */

	uint8_t		nAcks;		/* number of ACKs */
#define RXRPC_MAXACKS	255

	uint8_t		acks[];		/* list of ACK/NAKs */
#define RXRPC_ACK_TYPE_NACK		0
#define RXRPC_ACK_TYPE_ACK		1

} __packed;

/*
 * ACK packets can have a further piece of information tagged on the end
 */
struct rxrpc_ackinfo {
	__be32		rxMTU;		/* maximum Rx MTU size (bytes) [AFS 3.3] */
	__be32		maxMTU;		/* maximum interface MTU size (bytes) [AFS 3.3] */
	__be32		rwind;		/* Rx window size (packets) [AFS 3.4] */
	__be32		jumbo_max;	/* max packets to stick into a jumbo packet [AFS 3.5] */
};

/*****************************************************************************/
/*
 * Kerberos security type-2 challenge packet
 */
struct rxkad_challenge {
	__be32		version;	/* version of this challenge type */
	__be32		nonce;		/* encrypted random number */
	__be32		min_level;	/* minimum security level */
	__be32		__padding;	/* padding to 8-byte boundary */
} __packed;

/*****************************************************************************/
/*
 * Kerberos security type-2 response packet
 */
struct rxkad_response {
	__be32		version;	/* version of this response type */
	__be32		__pad;

	/* encrypted bit of the response */
	struct {
		__be32		epoch;		/* current epoch */
		__be32		cid;		/* parent connection ID */
		__be32		checksum;	/* checksum */
		__be32		securityIndex;	/* security type */
		__be32		call_id[4];	/* encrypted call IDs */
		__be32		inc_nonce;	/* challenge nonce + 1 */
		__be32		level;		/* desired level */
	} encrypted;

	__be32		kvno;		/* Kerberos key version number */
	__be32		ticket_len;	/* Kerberos ticket length  */
} __packed;

#endif /* _LINUX_RXRPC_PACKET_H */