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
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