xref: /linux/net/rxrpc/protocol.h (revision 5bdd5fbb35ab0fe21bf2263106f51c5bee466a07)
1 /* packet.h: Rx packet layout and definitions
2  *
3  * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved.
4  * Written by David Howells (dhowells@redhat.com)
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version
9  * 2 of the License, or (at your option) any later version.
10  */
11 
12 #ifndef _LINUX_RXRPC_PACKET_H
13 #define _LINUX_RXRPC_PACKET_H
14 
15 typedef u32	rxrpc_seq_t;	/* Rx message sequence number */
16 typedef u32	rxrpc_serial_t;	/* Rx message serial number */
17 typedef __be32	rxrpc_seq_net_t; /* on-the-wire Rx message sequence number */
18 typedef __be32	rxrpc_serial_net_t; /* on-the-wire Rx message serial number */
19 
20 /*****************************************************************************/
21 /*
22  * on-the-wire Rx packet header
23  * - all multibyte fields should be in network byte order
24  */
25 struct rxrpc_wire_header {
26 	__be32		epoch;		/* client boot timestamp */
27 #define RXRPC_RANDOM_EPOCH	0x80000000	/* Random if set, date-based if not */
28 
29 	__be32		cid;		/* connection and channel ID */
30 #define RXRPC_MAXCALLS		4			/* max active calls per conn */
31 #define RXRPC_CHANNELMASK	(RXRPC_MAXCALLS-1)	/* mask for channel ID */
32 #define RXRPC_CIDMASK		(~RXRPC_CHANNELMASK)	/* mask for connection ID */
33 #define RXRPC_CIDSHIFT		ilog2(RXRPC_MAXCALLS)	/* shift for connection ID */
34 #define RXRPC_CID_INC		(1 << RXRPC_CIDSHIFT)	/* connection ID increment */
35 
36 	__be32		callNumber;	/* call ID (0 for connection-level packets) */
37 	__be32		seq;		/* sequence number of pkt in call stream */
38 	__be32		serial;		/* serial number of pkt sent to network */
39 
40 	uint8_t		type;		/* packet type */
41 #define RXRPC_PACKET_TYPE_DATA		1	/* data */
42 #define RXRPC_PACKET_TYPE_ACK		2	/* ACK */
43 #define RXRPC_PACKET_TYPE_BUSY		3	/* call reject */
44 #define RXRPC_PACKET_TYPE_ABORT		4	/* call/connection abort */
45 #define RXRPC_PACKET_TYPE_ACKALL	5	/* ACK all outstanding packets on call */
46 #define RXRPC_PACKET_TYPE_CHALLENGE	6	/* connection security challenge (SRVR->CLNT) */
47 #define RXRPC_PACKET_TYPE_RESPONSE	7	/* connection secutity response (CLNT->SRVR) */
48 #define RXRPC_PACKET_TYPE_DEBUG		8	/* debug info request */
49 #define RXRPC_PACKET_TYPE_PARAMS	9	/* Parameter negotiation (unspec'd, ignore) */
50 #define RXRPC_PACKET_TYPE_10		10	/* Ignored */
51 #define RXRPC_PACKET_TYPE_11		11	/* Ignored */
52 #define RXRPC_PACKET_TYPE_VERSION	13	/* version string request */
53 #define RXRPC_N_PACKET_TYPES		14	/* number of packet types (incl type 0) */
54 
55 	uint8_t		flags;		/* packet flags */
56 #define RXRPC_CLIENT_INITIATED	0x01		/* signifies a packet generated by a client */
57 #define RXRPC_REQUEST_ACK	0x02		/* request an unconditional ACK of this packet */
58 #define RXRPC_LAST_PACKET	0x04		/* the last packet from this side for this call */
59 #define RXRPC_MORE_PACKETS	0x08		/* more packets to come */
60 #define RXRPC_JUMBO_PACKET	0x20		/* [DATA] this is a jumbo packet */
61 #define RXRPC_SLOW_START_OK	0x20		/* [ACK] slow start supported */
62 
63 	uint8_t		userStatus;	/* app-layer defined status */
64 #define RXRPC_USERSTATUS_SERVICE_UPGRADE 0x01	/* AuriStor service upgrade request */
65 
66 	uint8_t		securityIndex;	/* security protocol ID */
67 	union {
68 		__be16	_rsvd;		/* reserved */
69 		__be16	cksum;		/* kerberos security checksum */
70 	};
71 	__be16		serviceId;	/* service ID */
72 
73 } __packed;
74 
75 #define RXRPC_SUPPORTED_PACKET_TYPES (			\
76 		(1 << RXRPC_PACKET_TYPE_DATA) |		\
77 		(1 << RXRPC_PACKET_TYPE_ACK) |		\
78 		(1 << RXRPC_PACKET_TYPE_BUSY) |		\
79 		(1 << RXRPC_PACKET_TYPE_ABORT) |	\
80 		(1 << RXRPC_PACKET_TYPE_ACKALL) |	\
81 		(1 << RXRPC_PACKET_TYPE_CHALLENGE) |	\
82 		(1 << RXRPC_PACKET_TYPE_RESPONSE) |	\
83 		/*(1 << RXRPC_PACKET_TYPE_DEBUG) | */	\
84 		(1 << RXRPC_PACKET_TYPE_PARAMS) |	\
85 		(1 << RXRPC_PACKET_TYPE_10) |		\
86 		(1 << RXRPC_PACKET_TYPE_11) |		\
87 		(1 << RXRPC_PACKET_TYPE_VERSION))
88 
89 /*****************************************************************************/
90 /*
91  * jumbo packet secondary header
92  * - can be mapped to read header by:
93  *   - new_serial = serial + 1
94  *   - new_seq = seq + 1
95  *   - new_flags = j_flags
96  *   - new__rsvd = j__rsvd
97  *   - duplicating all other fields
98  */
99 struct rxrpc_jumbo_header {
100 	uint8_t		flags;		/* packet flags (as per rxrpc_header) */
101 	uint8_t		pad;
102 	union {
103 		__be16	_rsvd;		/* reserved */
104 		__be16	cksum;		/* kerberos security checksum */
105 	};
106 };
107 
108 #define RXRPC_JUMBO_DATALEN	1412	/* non-terminal jumbo packet data length */
109 #define RXRPC_JUMBO_SUBPKTLEN	(RXRPC_JUMBO_DATALEN + sizeof(struct rxrpc_jumbo_header))
110 
111 /*****************************************************************************/
112 /*
113  * on-the-wire Rx ACK packet data payload
114  * - all multibyte fields should be in network byte order
115  */
116 struct rxrpc_ackpacket {
117 	__be16		bufferSpace;	/* number of packet buffers available */
118 	__be16		maxSkew;	/* diff between serno being ACK'd and highest serial no
119 					 * received */
120 	__be32		firstPacket;	/* sequence no of first ACK'd packet in attached list */
121 	__be32		previousPacket;	/* sequence no of previous packet received */
122 	__be32		serial;		/* serial no of packet that prompted this ACK */
123 
124 	uint8_t		reason;		/* reason for ACK */
125 #define RXRPC_ACK_REQUESTED		1	/* ACK was requested on packet */
126 #define RXRPC_ACK_DUPLICATE		2	/* duplicate packet received */
127 #define RXRPC_ACK_OUT_OF_SEQUENCE	3	/* out of sequence packet received */
128 #define RXRPC_ACK_EXCEEDS_WINDOW	4	/* packet received beyond end of ACK window */
129 #define RXRPC_ACK_NOSPACE		5	/* packet discarded due to lack of buffer space */
130 #define RXRPC_ACK_PING			6	/* keep alive ACK */
131 #define RXRPC_ACK_PING_RESPONSE		7	/* response to RXRPC_ACK_PING */
132 #define RXRPC_ACK_DELAY			8	/* nothing happened since received packet */
133 #define RXRPC_ACK_IDLE			9	/* ACK due to fully received ACK window */
134 #define RXRPC_ACK__INVALID		10	/* Representation of invalid ACK reason */
135 
136 	uint8_t		nAcks;		/* number of ACKs */
137 #define RXRPC_MAXACKS	255
138 
139 	uint8_t		acks[0];	/* list of ACK/NAKs */
140 #define RXRPC_ACK_TYPE_NACK		0
141 #define RXRPC_ACK_TYPE_ACK		1
142 
143 } __packed;
144 
145 /* Some ACKs refer to specific packets and some are general and can be updated. */
146 #define RXRPC_ACK_UPDATEABLE ((1 << RXRPC_ACK_REQUESTED)	|	\
147 			      (1 << RXRPC_ACK_PING_RESPONSE)	|	\
148 			      (1 << RXRPC_ACK_DELAY)		|	\
149 			      (1 << RXRPC_ACK_IDLE))
150 
151 
152 /*
153  * ACK packets can have a further piece of information tagged on the end
154  */
155 struct rxrpc_ackinfo {
156 	__be32		rxMTU;		/* maximum Rx MTU size (bytes) [AFS 3.3] */
157 	__be32		maxMTU;		/* maximum interface MTU size (bytes) [AFS 3.3] */
158 	__be32		rwind;		/* Rx window size (packets) [AFS 3.4] */
159 	__be32		jumbo_max;	/* max packets to stick into a jumbo packet [AFS 3.5] */
160 };
161 
162 /*****************************************************************************/
163 /*
164  * Kerberos security type-2 challenge packet
165  */
166 struct rxkad_challenge {
167 	__be32		version;	/* version of this challenge type */
168 	__be32		nonce;		/* encrypted random number */
169 	__be32		min_level;	/* minimum security level */
170 	__be32		__padding;	/* padding to 8-byte boundary */
171 } __packed;
172 
173 /*****************************************************************************/
174 /*
175  * Kerberos security type-2 response packet
176  */
177 struct rxkad_response {
178 	__be32		version;	/* version of this response type */
179 	__be32		__pad;
180 
181 	/* encrypted bit of the response */
182 	struct {
183 		__be32		epoch;		/* current epoch */
184 		__be32		cid;		/* parent connection ID */
185 		__be32		checksum;	/* checksum */
186 		__be32		securityIndex;	/* security type */
187 		__be32		call_id[4];	/* encrypted call IDs */
188 		__be32		inc_nonce;	/* challenge nonce + 1 */
189 		__be32		level;		/* desired level */
190 	} encrypted;
191 
192 	__be32		kvno;		/* Kerberos key version number */
193 	__be32		ticket_len;	/* Kerberos ticket length  */
194 } __packed;
195 
196 #endif /* _LINUX_RXRPC_PACKET_H */
197