xref: /linux/net/rxrpc/protocol.h (revision cc8c418b4fc09ed58ddd27b8e90ec797e9ca1e67)
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 
11 typedef u32	rxrpc_seq_t;	/* Rx message sequence number */
12 typedef u32	rxrpc_serial_t;	/* Rx message serial number */
13 typedef __be32	rxrpc_seq_net_t; /* on-the-wire Rx message sequence number */
14 typedef __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  */
21 struct 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  */
80 struct 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 };
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_IP - IP_hdr - UDP_hdr) / RXRPC_JUMBO_SUBPKTLEN) + 1
96  *	= ((65535 - 28 - 28) / 1416) + 1
97  *	= 46 non-terminal packets and 1 terminal packet.
98  */
99 #define RXRPC_MAX_NR_JUMBO	47
100 
101 /*****************************************************************************/
102 /*
103  * on-the-wire Rx ACK packet data payload
104  * - all multibyte fields should be in network byte order
105  */
106 struct rxrpc_ackpacket {
107 	__be16		bufferSpace;	/* number of packet buffers available */
108 	__be16		maxSkew;	/* diff between serno being ACK'd and highest serial no
109 					 * received */
110 	__be32		firstPacket;	/* sequence no of first ACK'd packet in attached list */
111 	__be32		previousPacket;	/* sequence no of previous packet received */
112 	__be32		serial;		/* serial no of packet that prompted this ACK */
113 
114 	uint8_t		reason;		/* reason for ACK */
115 #define RXRPC_ACK_REQUESTED		1	/* ACK was requested on packet */
116 #define RXRPC_ACK_DUPLICATE		2	/* duplicate packet received */
117 #define RXRPC_ACK_OUT_OF_SEQUENCE	3	/* out of sequence packet received */
118 #define RXRPC_ACK_EXCEEDS_WINDOW	4	/* packet received beyond end of ACK window */
119 #define RXRPC_ACK_NOSPACE		5	/* packet discarded due to lack of buffer space */
120 #define RXRPC_ACK_PING			6	/* keep alive ACK */
121 #define RXRPC_ACK_PING_RESPONSE		7	/* response to RXRPC_ACK_PING */
122 #define RXRPC_ACK_DELAY			8	/* nothing happened since received packet */
123 #define RXRPC_ACK_IDLE			9	/* ACK due to fully received ACK window */
124 #define RXRPC_ACK__INVALID		10	/* Representation of invalid ACK reason */
125 
126 	uint8_t		nAcks;		/* number of ACKs */
127 #define RXRPC_MAXACKS	255
128 
129 	uint8_t		acks[0];	/* list of ACK/NAKs */
130 #define RXRPC_ACK_TYPE_NACK		0
131 #define RXRPC_ACK_TYPE_ACK		1
132 
133 } __packed;
134 
135 /* Some ACKs refer to specific packets and some are general and can be updated. */
136 #define RXRPC_ACK_UPDATEABLE ((1 << RXRPC_ACK_REQUESTED)	|	\
137 			      (1 << RXRPC_ACK_PING_RESPONSE)	|	\
138 			      (1 << RXRPC_ACK_DELAY)		|	\
139 			      (1 << RXRPC_ACK_IDLE))
140 
141 
142 /*
143  * ACK packets can have a further piece of information tagged on the end
144  */
145 struct rxrpc_ackinfo {
146 	__be32		rxMTU;		/* maximum Rx MTU size (bytes) [AFS 3.3] */
147 	__be32		maxMTU;		/* maximum interface MTU size (bytes) [AFS 3.3] */
148 	__be32		rwind;		/* Rx window size (packets) [AFS 3.4] */
149 	__be32		jumbo_max;	/* max packets to stick into a jumbo packet [AFS 3.5] */
150 };
151 
152 /*****************************************************************************/
153 /*
154  * Kerberos security type-2 challenge packet
155  */
156 struct rxkad_challenge {
157 	__be32		version;	/* version of this challenge type */
158 	__be32		nonce;		/* encrypted random number */
159 	__be32		min_level;	/* minimum security level */
160 	__be32		__padding;	/* padding to 8-byte boundary */
161 } __packed;
162 
163 /*****************************************************************************/
164 /*
165  * Kerberos security type-2 response packet
166  */
167 struct rxkad_response {
168 	__be32		version;	/* version of this response type */
169 	__be32		__pad;
170 
171 	/* encrypted bit of the response */
172 	struct {
173 		__be32		epoch;		/* current epoch */
174 		__be32		cid;		/* parent connection ID */
175 		__be32		checksum;	/* checksum */
176 		__be32		securityIndex;	/* security type */
177 		__be32		call_id[4];	/* encrypted call IDs */
178 		__be32		inc_nonce;	/* challenge nonce + 1 */
179 		__be32		level;		/* desired level */
180 	} encrypted;
181 
182 	__be32		kvno;		/* Kerberos key version number */
183 	__be32		ticket_len;	/* Kerberos ticket length  */
184 } __packed;
185 
186 #endif /* _LINUX_RXRPC_PACKET_H */
187