xref: /dpdk/lib/net/rte_l2tpv2.h (revision 988cd040)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2021 Intel Corporation.
3  */
4 
5 #ifndef _RTE_L2TPV2_H_
6 #define _RTE_L2TPV2_H_
7 
8 /**
9  * @file
10  *
11  * L2TP header:
12  *
13  * `-0--------------------1----------------2-------------------3`
14  *
15  * `-0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1`
16  *
17  * `+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+`
18  *
19  * `|T|L|x|x|S|x|O|P|x|x|x|x|--Ver--|-----------Length (opt)--------|`
20  *
21  * `+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+`
22  *
23  * `|-----------Tunnel ID-----------|-----------Session ID----------|`
24  *
25  * `+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+`
26  *
27  * `|-----------Ns (opt)------------|-----------Nr (opt)------------|`
28  *
29  * `+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+`
30  *
31  * `|---------Offset Size (opt)-----|---------Offset pad... (opt)`
32  *
33  * `+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+`
34  *
35  * The Type (T) bit indicates the type of message. It is set to 0 for a data
36  * message and 1 for a control message.
37  *
38  * If the Length (L) bit is 1, the Length field is present. This bit MUST be
39  * set to 1 for control messages.
40  *
41  * The x bits are reserved for future extensions. All reserved bits MUST
42  * be set to 0 on outgoing messages and ignored on incoming messages.
43  *
44  * If the Sequence (S) bit is set to 1 the Ns and Nr fields are present.
45  * The S bit MUST be set to 1 for control messages.
46  *
47  * If the Offset (O) bit is 1, the Offset Size field is present. The O
48  * bit MUST be set to 0 for control messages.
49  *
50  * If the Priority (P) bit is 1, this data message should receive
51  * preferential treatment in its local queuing and transmission.
52  * The P bit MUST be set to 0 for control messages.
53  *
54  * Ver MUST be 2, indicating the version of the L2TP data message header.
55  *
56  * The Length field indicates the total length of the message in octets.
57  *
58  * Tunnel ID indicates the identifier for the control connection.
59  *
60  * Session ID indicates the identifier for a session within a tunnel.
61  *
62  * Ns indicates the sequence number for this data or control message.
63  *
64  * Nr indicates the sequence number expected in the next control message
65  * to be received.
66  *
67  * The Offset Size field, if present, specifies the number of octets
68  * past the L2TP header at which the payload data is expected to start.
69  * Actual data within the offset padding is undefined. If the offset
70  * field is present, the L2TP header ends after the last octet of the
71  * offset padding.
72  */
73 
74 #include <stdint.h>
75 #include <rte_byteorder.h>
76 
77 #ifdef __cplusplus
78 extern "C" {
79 #endif
80 
81 /*
82  * L2TPv2 Message Type
83  */
84 #define RTE_L2TPV2_MSG_TYPE_CONTROL	0xC802
85 #define RTE_L2TPV2_MSG_TYPE_DATA	0x0002
86 #define RTE_L2TPV2_MSG_TYPE_DATA_L	0x4002
87 #define RTE_L2TPV2_MSG_TYPE_DATA_S	0x0802
88 #define RTE_L2TPV2_MSG_TYPE_DATA_O	0x0202
89 #define RTE_L2TPV2_MSG_TYPE_DATA_L_S	0x4802
90 #define RTE_L2TPV2_MSG_TYPE_DATA_L_O	0x4202
91 #define RTE_L2TPV2_MSG_TYPE_DATA_S_O	0x0A02
92 #define RTE_L2TPV2_MSG_TYPE_DATA_L_S_O	0x4A02
93 
94 /**
95  * L2TPv2 Common Header
96  */
97 RTE_STD_C11
98 struct rte_l2tpv2_common_hdr {
99 	union {
100 		/** header flags and protocol version */
101 		rte_be16_t flags_version;
102 		__extension__
103 		struct {
104 #if RTE_BYTE_ORDER == RTE_LITTLE_ENDIAN
105 			uint16_t ver:4;		/**< protocol version */
106 			uint16_t res3:4;	/**< reserved */
107 			uint16_t p:1;		/**< priority option bit */
108 			uint16_t o:1;		/**< offset option bit */
109 			uint16_t res2:1;	/**< reserved */
110 			uint16_t s:1;		/**< ns/nr option bit */
111 			uint16_t res1:2;	/**< reserved */
112 			uint16_t l:1;		/**< length option bit */
113 			uint16_t t:1;		/**< message Type */
114 #elif RTE_BYTE_ORDER == RTE_BIG_ENDIAN
115 			uint16_t t:1;		/**< message Type */
116 			uint16_t l:1;		/**< length option bit */
117 			uint16_t res1:2;	/**< reserved */
118 			uint16_t s:1;		/**< ns/nr option bit */
119 			uint16_t res2:1;	/**< reserved */
120 			uint16_t o:1;		/**< offset option bit */
121 			uint16_t p:1;		/**< priority option bit */
122 			uint16_t res3:4;	/**< reserved */
123 			uint16_t ver:4;		/**< protocol version */
124 #endif
125 		};
126 	};
127 };
128 
129 /**
130  * L2TPv2 message Header contains all options(length, ns, nr,
131  * offset size, offset padding).
132  */
133 struct rte_l2tpv2_msg_with_all_options {
134 	rte_be16_t length;		/**< length(16) */
135 	rte_be16_t tunnel_id;		/**< tunnel ID(16) */
136 	rte_be16_t session_id;		/**< session ID(16) */
137 	rte_be16_t ns;			/**< Ns(16) */
138 	rte_be16_t nr;			/**< Nr(16) */
139 	rte_be16_t offset_size;		/**< offset size(16) */
140 	uint8_t   *offset_padding;	/**< offset padding(variable length) */
141 } __rte_packed;
142 
143 /**
144  * L2TPv2 message Header contains all options except length(ns, nr,
145  * offset size, offset padding).
146  */
147 struct rte_l2tpv2_msg_without_length {
148 	rte_be16_t tunnel_id;		/**< tunnel ID(16) */
149 	rte_be16_t session_id;		/**< session ID(16) */
150 	rte_be16_t ns;			/**< Ns(16) */
151 	rte_be16_t nr;			/**< Nr(16) */
152 	rte_be16_t offset_size;		/**< offset size(16) */
153 	uint8_t   *offset_padding;	/**< offset padding(variable length) */
154 } __rte_packed;
155 
156 /**
157  * L2TPv2 message Header contains all options except ns_nr(length,
158  * offset size, offset padding).
159  * Ns and Nr MUST be together.
160  */
161 struct rte_l2tpv2_msg_without_ns_nr {
162 	rte_be16_t length;		/**< length(16) */
163 	rte_be16_t tunnel_id;		/**< tunnel ID(16) */
164 	rte_be16_t session_id;		/**< session ID(16) */
165 	rte_be16_t offset_size;		/**< offset size(16) */
166 	uint8_t   *offset_padding;	/**< offset padding(variable length) */
167 };
168 
169 /**
170  * L2TPv2 message Header contains all options except ns_nr(length, ns, nr).
171  * offset size and offset padding MUST be together.
172  */
173 struct rte_l2tpv2_msg_without_offset {
174 	rte_be16_t length;		/**< length(16) */
175 	rte_be16_t tunnel_id;		/**< tunnel ID(16) */
176 	rte_be16_t session_id;		/**< session ID(16) */
177 	rte_be16_t ns;			/**< Ns(16) */
178 	rte_be16_t nr;			/**< Nr(16) */
179 };
180 
181 /**
182  * L2TPv2 message Header contains options offset size and offset padding.
183  */
184 struct rte_l2tpv2_msg_with_offset {
185 	rte_be16_t tunnel_id;		/**< tunnel ID(16) */
186 	rte_be16_t session_id;		/**< session ID(16) */
187 	rte_be16_t offset_size;		/**< offset size(16) */
188 	uint8_t   *offset_padding;	/**< offset padding(variable length) */
189 } __rte_packed;
190 
191 /**
192  * L2TPv2 message Header contains options ns and nr.
193  */
194 struct rte_l2tpv2_msg_with_ns_nr {
195 	rte_be16_t tunnel_id;		/**< tunnel ID(16) */
196 	rte_be16_t session_id;		/**< session ID(16) */
197 	rte_be16_t ns;			/**< Ns(16) */
198 	rte_be16_t nr;			/**< Nr(16) */
199 };
200 
201 /**
202  * L2TPv2 message Header contains option length.
203  */
204 struct rte_l2tpv2_msg_with_length {
205 	rte_be16_t length;		/**< length(16) */
206 	rte_be16_t tunnel_id;		/**< tunnel ID(16) */
207 	rte_be16_t session_id;		/**< session ID(16) */
208 };
209 
210 /**
211  * L2TPv2 message Header without all options.
212  */
213 struct rte_l2tpv2_msg_without_all_options {
214 	rte_be16_t tunnel_id;		/**< tunnel ID(16) */
215 	rte_be16_t session_id;		/**< session ID(16) */
216 };
217 
218 /**
219  * L2TPv2 Combined Message Header Format: Common Header + Options
220  */
221 RTE_STD_C11
222 struct rte_l2tpv2_combined_msg_hdr {
223 	struct rte_l2tpv2_common_hdr common; /**< common header */
224 	union {
225 		/** header with all options */
226 		struct rte_l2tpv2_msg_with_all_options type0;
227 		/** header with all options except length */
228 		struct rte_l2tpv2_msg_without_length type1;
229 		/** header with all options except ns/nr */
230 		struct rte_l2tpv2_msg_without_ns_nr type2;
231 		/** header with all options except offset */
232 		struct rte_l2tpv2_msg_without_offset type3;
233 		/** header with offset options */
234 		struct rte_l2tpv2_msg_with_offset type4;
235 		/** header with ns/nr options */
236 		struct rte_l2tpv2_msg_with_ns_nr type5;
237 		/** header with length option */
238 		struct rte_l2tpv2_msg_with_length type6;
239 		/** header without all options */
240 		struct rte_l2tpv2_msg_without_all_options type7;
241 	};
242 } __rte_packed;
243 
244 #ifdef __cplusplus
245 }
246 #endif
247 
248 #endif /* _RTE_L2TPV2_H_ */
249