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  } __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_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[];		/* list of ACK/NAKs */
130  #define RXRPC_ACK_TYPE_NACK		0
131  #define RXRPC_ACK_TYPE_ACK		1
132  
133  } __packed;
134  
135  /*
136   * ACK packets can have a further piece of information tagged on the end
137   */
138  struct rxrpc_acktrailer {
139  	__be32		maxMTU;		/* maximum Rx MTU size (bytes) [AFS 3.3] */
140  	__be32		ifMTU;		/* maximum interface MTU size (bytes) [AFS 3.3] */
141  	__be32		rwind;		/* Rx window size (packets) [AFS 3.4] */
142  	__be32		jumbo_max;	/* max packets to stick into a jumbo packet [AFS 3.5] */
143  };
144  
145  /*****************************************************************************/
146  /*
147   * Kerberos security type-2 challenge packet
148   */
149  struct rxkad_challenge {
150  	__be32		version;	/* version of this challenge type */
151  	__be32		nonce;		/* encrypted random number */
152  	__be32		min_level;	/* minimum security level */
153  	__be32		__padding;	/* padding to 8-byte boundary */
154  } __packed;
155  
156  /*****************************************************************************/
157  /*
158   * Kerberos security type-2 response packet
159   */
160  struct rxkad_response {
161  	__be32		version;	/* version of this response type */
162  	__be32		__pad;
163  
164  	/* encrypted bit of the response */
165  	struct {
166  		__be32		epoch;		/* current epoch */
167  		__be32		cid;		/* parent connection ID */
168  		__be32		checksum;	/* checksum */
169  		__be32		securityIndex;	/* security type */
170  		__be32		call_id[4];	/* encrypted call IDs */
171  		__be32		inc_nonce;	/* challenge nonce + 1 */
172  		__be32		level;		/* desired level */
173  	} encrypted;
174  
175  	__be32		kvno;		/* Kerberos key version number */
176  	__be32		ticket_len;	/* Kerberos ticket length  */
177  } __packed;
178  
179  #endif /* _LINUX_RXRPC_PACKET_H */
180