xref: /openbmc/linux/include/net/flow_dissector.h (revision 4b4f3acc)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _NET_FLOW_DISSECTOR_H
3 #define _NET_FLOW_DISSECTOR_H
4 
5 #include <linux/types.h>
6 #include <linux/in6.h>
7 #include <uapi/linux/if_ether.h>
8 
9 /**
10  * struct flow_dissector_key_control:
11  * @thoff: Transport header offset
12  */
13 struct flow_dissector_key_control {
14 	u16	thoff;
15 	u16	addr_type;
16 	u32	flags;
17 };
18 
19 #define FLOW_DIS_IS_FRAGMENT	BIT(0)
20 #define FLOW_DIS_FIRST_FRAG	BIT(1)
21 #define FLOW_DIS_ENCAPSULATION	BIT(2)
22 
23 enum flow_dissect_ret {
24 	FLOW_DISSECT_RET_OUT_GOOD,
25 	FLOW_DISSECT_RET_OUT_BAD,
26 	FLOW_DISSECT_RET_PROTO_AGAIN,
27 	FLOW_DISSECT_RET_IPPROTO_AGAIN,
28 	FLOW_DISSECT_RET_CONTINUE,
29 };
30 
31 /**
32  * struct flow_dissector_key_basic:
33  * @thoff: Transport header offset
34  * @n_proto: Network header protocol (eg. IPv4/IPv6)
35  * @ip_proto: Transport header protocol (eg. TCP/UDP)
36  */
37 struct flow_dissector_key_basic {
38 	__be16	n_proto;
39 	u8	ip_proto;
40 	u8	padding;
41 };
42 
43 struct flow_dissector_key_tags {
44 	u32	flow_label;
45 };
46 
47 struct flow_dissector_key_vlan {
48 	u16	vlan_id:12,
49 		vlan_dei:1,
50 		vlan_priority:3;
51 	__be16	vlan_tpid;
52 };
53 
54 struct flow_dissector_key_mpls {
55 	u32	mpls_ttl:8,
56 		mpls_bos:1,
57 		mpls_tc:3,
58 		mpls_label:20;
59 };
60 
61 #define FLOW_DIS_TUN_OPTS_MAX 255
62 /**
63  * struct flow_dissector_key_enc_opts:
64  * @data: tunnel option data
65  * @len: length of tunnel option data
66  * @dst_opt_type: tunnel option type
67  */
68 struct flow_dissector_key_enc_opts {
69 	u8 data[FLOW_DIS_TUN_OPTS_MAX];	/* Using IP_TUNNEL_OPTS_MAX is desired
70 					 * here but seems difficult to #include
71 					 */
72 	u8 len;
73 	__be16 dst_opt_type;
74 };
75 
76 struct flow_dissector_key_keyid {
77 	__be32	keyid;
78 };
79 
80 /**
81  * struct flow_dissector_key_ipv4_addrs:
82  * @src: source ip address
83  * @dst: destination ip address
84  */
85 struct flow_dissector_key_ipv4_addrs {
86 	/* (src,dst) must be grouped, in the same way than in IP header */
87 	__be32 src;
88 	__be32 dst;
89 };
90 
91 /**
92  * struct flow_dissector_key_ipv6_addrs:
93  * @src: source ip address
94  * @dst: destination ip address
95  */
96 struct flow_dissector_key_ipv6_addrs {
97 	/* (src,dst) must be grouped, in the same way than in IP header */
98 	struct in6_addr src;
99 	struct in6_addr dst;
100 };
101 
102 /**
103  * struct flow_dissector_key_tipc:
104  * @key: source node address combined with selector
105  */
106 struct flow_dissector_key_tipc {
107 	__be32 key;
108 };
109 
110 /**
111  * struct flow_dissector_key_addrs:
112  * @v4addrs: IPv4 addresses
113  * @v6addrs: IPv6 addresses
114  */
115 struct flow_dissector_key_addrs {
116 	union {
117 		struct flow_dissector_key_ipv4_addrs v4addrs;
118 		struct flow_dissector_key_ipv6_addrs v6addrs;
119 		struct flow_dissector_key_tipc tipckey;
120 	};
121 };
122 
123 /**
124  * flow_dissector_key_arp:
125  *	@ports: Operation, source and target addresses for an ARP header
126  *              for Ethernet hardware addresses and IPv4 protocol addresses
127  *		sip: Sender IP address
128  *		tip: Target IP address
129  *		op:  Operation
130  *		sha: Sender hardware address
131  *		tpa: Target hardware address
132  */
133 struct flow_dissector_key_arp {
134 	__u32 sip;
135 	__u32 tip;
136 	__u8 op;
137 	unsigned char sha[ETH_ALEN];
138 	unsigned char tha[ETH_ALEN];
139 };
140 
141 /**
142  * flow_dissector_key_tp_ports:
143  *	@ports: port numbers of Transport header
144  *		src: source port number
145  *		dst: destination port number
146  */
147 struct flow_dissector_key_ports {
148 	union {
149 		__be32 ports;
150 		struct {
151 			__be16 src;
152 			__be16 dst;
153 		};
154 	};
155 };
156 
157 /**
158  * flow_dissector_key_icmp:
159  *	@ports: type and code of ICMP header
160  *		icmp: ICMP type (high) and code (low)
161  *		type: ICMP type
162  *		code: ICMP code
163  */
164 struct flow_dissector_key_icmp {
165 	union {
166 		__be16 icmp;
167 		struct {
168 			u8 type;
169 			u8 code;
170 		};
171 	};
172 };
173 
174 /**
175  * struct flow_dissector_key_eth_addrs:
176  * @src: source Ethernet address
177  * @dst: destination Ethernet address
178  */
179 struct flow_dissector_key_eth_addrs {
180 	/* (dst,src) must be grouped, in the same way than in ETH header */
181 	unsigned char dst[ETH_ALEN];
182 	unsigned char src[ETH_ALEN];
183 };
184 
185 /**
186  * struct flow_dissector_key_tcp:
187  * @flags: flags
188  */
189 struct flow_dissector_key_tcp {
190 	__be16 flags;
191 };
192 
193 /**
194  * struct flow_dissector_key_ip:
195  * @tos: tos
196  * @ttl: ttl
197  */
198 struct flow_dissector_key_ip {
199 	__u8	tos;
200 	__u8	ttl;
201 };
202 
203 enum flow_dissector_key_id {
204 	FLOW_DISSECTOR_KEY_CONTROL, /* struct flow_dissector_key_control */
205 	FLOW_DISSECTOR_KEY_BASIC, /* struct flow_dissector_key_basic */
206 	FLOW_DISSECTOR_KEY_IPV4_ADDRS, /* struct flow_dissector_key_ipv4_addrs */
207 	FLOW_DISSECTOR_KEY_IPV6_ADDRS, /* struct flow_dissector_key_ipv6_addrs */
208 	FLOW_DISSECTOR_KEY_PORTS, /* struct flow_dissector_key_ports */
209 	FLOW_DISSECTOR_KEY_ICMP, /* struct flow_dissector_key_icmp */
210 	FLOW_DISSECTOR_KEY_ETH_ADDRS, /* struct flow_dissector_key_eth_addrs */
211 	FLOW_DISSECTOR_KEY_TIPC, /* struct flow_dissector_key_tipc */
212 	FLOW_DISSECTOR_KEY_ARP, /* struct flow_dissector_key_arp */
213 	FLOW_DISSECTOR_KEY_VLAN, /* struct flow_dissector_key_vlan */
214 	FLOW_DISSECTOR_KEY_FLOW_LABEL, /* struct flow_dissector_key_tags */
215 	FLOW_DISSECTOR_KEY_GRE_KEYID, /* struct flow_dissector_key_keyid */
216 	FLOW_DISSECTOR_KEY_MPLS_ENTROPY, /* struct flow_dissector_key_keyid */
217 	FLOW_DISSECTOR_KEY_ENC_KEYID, /* struct flow_dissector_key_keyid */
218 	FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS, /* struct flow_dissector_key_ipv4_addrs */
219 	FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS, /* struct flow_dissector_key_ipv6_addrs */
220 	FLOW_DISSECTOR_KEY_ENC_CONTROL, /* struct flow_dissector_key_control */
221 	FLOW_DISSECTOR_KEY_ENC_PORTS, /* struct flow_dissector_key_ports */
222 	FLOW_DISSECTOR_KEY_MPLS, /* struct flow_dissector_key_mpls */
223 	FLOW_DISSECTOR_KEY_TCP, /* struct flow_dissector_key_tcp */
224 	FLOW_DISSECTOR_KEY_IP, /* struct flow_dissector_key_ip */
225 	FLOW_DISSECTOR_KEY_CVLAN, /* struct flow_dissector_key_vlan */
226 	FLOW_DISSECTOR_KEY_ENC_IP, /* struct flow_dissector_key_ip */
227 	FLOW_DISSECTOR_KEY_ENC_OPTS, /* struct flow_dissector_key_enc_opts */
228 
229 	FLOW_DISSECTOR_KEY_MAX,
230 };
231 
232 #define FLOW_DISSECTOR_F_PARSE_1ST_FRAG		BIT(0)
233 #define FLOW_DISSECTOR_F_STOP_AT_L3		BIT(1)
234 #define FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL	BIT(2)
235 #define FLOW_DISSECTOR_F_STOP_AT_ENCAP		BIT(3)
236 
237 struct flow_dissector_key {
238 	enum flow_dissector_key_id key_id;
239 	size_t offset; /* offset of struct flow_dissector_key_*
240 			  in target the struct */
241 };
242 
243 struct flow_dissector {
244 	unsigned int used_keys; /* each bit repesents presence of one key id */
245 	unsigned short int offset[FLOW_DISSECTOR_KEY_MAX];
246 };
247 
248 struct flow_keys_basic {
249 	struct flow_dissector_key_control control;
250 	struct flow_dissector_key_basic basic;
251 };
252 
253 struct flow_keys {
254 	struct flow_dissector_key_control control;
255 #define FLOW_KEYS_HASH_START_FIELD basic
256 	struct flow_dissector_key_basic basic;
257 	struct flow_dissector_key_tags tags;
258 	struct flow_dissector_key_vlan vlan;
259 	struct flow_dissector_key_vlan cvlan;
260 	struct flow_dissector_key_keyid keyid;
261 	struct flow_dissector_key_ports ports;
262 	struct flow_dissector_key_addrs addrs;
263 };
264 
265 #define FLOW_KEYS_HASH_OFFSET		\
266 	offsetof(struct flow_keys, FLOW_KEYS_HASH_START_FIELD)
267 
268 __be32 flow_get_u32_src(const struct flow_keys *flow);
269 __be32 flow_get_u32_dst(const struct flow_keys *flow);
270 
271 extern struct flow_dissector flow_keys_dissector;
272 extern struct flow_dissector flow_keys_basic_dissector;
273 
274 /* struct flow_keys_digest:
275  *
276  * This structure is used to hold a digest of the full flow keys. This is a
277  * larger "hash" of a flow to allow definitively matching specific flows where
278  * the 32 bit skb->hash is not large enough. The size is limited to 16 bytes so
279  * that it can be used in CB of skb (see sch_choke for an example).
280  */
281 #define FLOW_KEYS_DIGEST_LEN	16
282 struct flow_keys_digest {
283 	u8	data[FLOW_KEYS_DIGEST_LEN];
284 };
285 
286 void make_flow_keys_digest(struct flow_keys_digest *digest,
287 			   const struct flow_keys *flow);
288 
289 static inline bool flow_keys_have_l4(const struct flow_keys *keys)
290 {
291 	return (keys->ports.ports || keys->tags.flow_label);
292 }
293 
294 u32 flow_hash_from_keys(struct flow_keys *keys);
295 
296 static inline bool dissector_uses_key(const struct flow_dissector *flow_dissector,
297 				      enum flow_dissector_key_id key_id)
298 {
299 	return flow_dissector->used_keys & (1 << key_id);
300 }
301 
302 static inline void *skb_flow_dissector_target(struct flow_dissector *flow_dissector,
303 					      enum flow_dissector_key_id key_id,
304 					      void *target_container)
305 {
306 	return ((char *)target_container) + flow_dissector->offset[key_id];
307 }
308 
309 struct bpf_flow_dissector {
310 	struct bpf_flow_keys	*flow_keys;
311 	const struct sk_buff	*skb;
312 	void			*data;
313 	void			*data_end;
314 };
315 
316 #endif
317