xref: /linux/include/net/flow_dissector.h (revision 52338415) 
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 <linux/siphash.h>
8 #include <uapi/linux/if_ether.h>
9 
10 /**
11  * struct flow_dissector_key_control:
12  * @thoff: Transport header offset
13  */
14 struct flow_dissector_key_control {
15 	u16	thoff;
16 	u16	addr_type;
17 	u32	flags;
18 };
19 
20 #define FLOW_DIS_IS_FRAGMENT	BIT(0)
21 #define FLOW_DIS_FIRST_FRAG	BIT(1)
22 #define FLOW_DIS_ENCAPSULATION	BIT(2)
23 
24 enum flow_dissect_ret {
25 	FLOW_DISSECT_RET_OUT_GOOD,
26 	FLOW_DISSECT_RET_OUT_BAD,
27 	FLOW_DISSECT_RET_PROTO_AGAIN,
28 	FLOW_DISSECT_RET_IPPROTO_AGAIN,
29 	FLOW_DISSECT_RET_CONTINUE,
30 };
31 
32 /**
33  * struct flow_dissector_key_basic:
34  * @thoff: Transport header offset
35  * @n_proto: Network header protocol (eg. IPv4/IPv6)
36  * @ip_proto: Transport header protocol (eg. TCP/UDP)
37  */
38 struct flow_dissector_key_basic {
39 	__be16	n_proto;
40 	u8	ip_proto;
41 	u8	padding;
42 };
43 
44 struct flow_dissector_key_tags {
45 	u32	flow_label;
46 };
47 
48 struct flow_dissector_key_vlan {
49 	u16	vlan_id:12,
50 		vlan_dei:1,
51 		vlan_priority:3;
52 	__be16	vlan_tpid;
53 };
54 
55 struct flow_dissector_key_mpls {
56 	u32	mpls_ttl:8,
57 		mpls_bos:1,
58 		mpls_tc:3,
59 		mpls_label:20;
60 };
61 
62 #define FLOW_DIS_TUN_OPTS_MAX 255
63 /**
64  * struct flow_dissector_key_enc_opts:
65  * @data: tunnel option data
66  * @len: length of tunnel option data
67  * @dst_opt_type: tunnel option type
68  */
69 struct flow_dissector_key_enc_opts {
70 	u8 data[FLOW_DIS_TUN_OPTS_MAX];	/* Using IP_TUNNEL_OPTS_MAX is desired
71 					 * here but seems difficult to #include
72 					 */
73 	u8 len;
74 	__be16 dst_opt_type;
75 };
76 
77 struct flow_dissector_key_keyid {
78 	__be32	keyid;
79 };
80 
81 /**
82  * struct flow_dissector_key_ipv4_addrs:
83  * @src: source ip address
84  * @dst: destination ip address
85  */
86 struct flow_dissector_key_ipv4_addrs {
87 	/* (src,dst) must be grouped, in the same way than in IP header */
88 	__be32 src;
89 	__be32 dst;
90 };
91 
92 /**
93  * struct flow_dissector_key_ipv6_addrs:
94  * @src: source ip address
95  * @dst: destination ip address
96  */
97 struct flow_dissector_key_ipv6_addrs {
98 	/* (src,dst) must be grouped, in the same way than in IP header */
99 	struct in6_addr src;
100 	struct in6_addr dst;
101 };
102 
103 /**
104  * struct flow_dissector_key_tipc:
105  * @key: source node address combined with selector
106  */
107 struct flow_dissector_key_tipc {
108 	__be32 key;
109 };
110 
111 /**
112  * struct flow_dissector_key_addrs:
113  * @v4addrs: IPv4 addresses
114  * @v6addrs: IPv6 addresses
115  */
116 struct flow_dissector_key_addrs {
117 	union {
118 		struct flow_dissector_key_ipv4_addrs v4addrs;
119 		struct flow_dissector_key_ipv6_addrs v6addrs;
120 		struct flow_dissector_key_tipc tipckey;
121 	};
122 };
123 
124 /**
125  * flow_dissector_key_arp:
126  *	@ports: Operation, source and target addresses for an ARP header
127  *              for Ethernet hardware addresses and IPv4 protocol addresses
128  *		sip: Sender IP address
129  *		tip: Target IP address
130  *		op:  Operation
131  *		sha: Sender hardware address
132  *		tpa: Target hardware address
133  */
134 struct flow_dissector_key_arp {
135 	__u32 sip;
136 	__u32 tip;
137 	__u8 op;
138 	unsigned char sha[ETH_ALEN];
139 	unsigned char tha[ETH_ALEN];
140 };
141 
142 /**
143  * flow_dissector_key_tp_ports:
144  *	@ports: port numbers of Transport header
145  *		src: source port number
146  *		dst: destination port number
147  */
148 struct flow_dissector_key_ports {
149 	union {
150 		__be32 ports;
151 		struct {
152 			__be16 src;
153 			__be16 dst;
154 		};
155 	};
156 };
157 
158 /**
159  * flow_dissector_key_icmp:
160  *	@ports: type and code of ICMP header
161  *		icmp: ICMP type (high) and code (low)
162  *		type: ICMP type
163  *		code: ICMP code
164  */
165 struct flow_dissector_key_icmp {
166 	union {
167 		__be16 icmp;
168 		struct {
169 			u8 type;
170 			u8 code;
171 		};
172 	};
173 };
174 
175 /**
176  * struct flow_dissector_key_eth_addrs:
177  * @src: source Ethernet address
178  * @dst: destination Ethernet address
179  */
180 struct flow_dissector_key_eth_addrs {
181 	/* (dst,src) must be grouped, in the same way than in ETH header */
182 	unsigned char dst[ETH_ALEN];
183 	unsigned char src[ETH_ALEN];
184 };
185 
186 /**
187  * struct flow_dissector_key_tcp:
188  * @flags: flags
189  */
190 struct flow_dissector_key_tcp {
191 	__be16 flags;
192 };
193 
194 /**
195  * struct flow_dissector_key_ip:
196  * @tos: tos
197  * @ttl: ttl
198  */
199 struct flow_dissector_key_ip {
200 	__u8	tos;
201 	__u8	ttl;
202 };
203 
204 /**
205  * struct flow_dissector_key_meta:
206  * @ingress_ifindex: ingress ifindex
207  */
208 struct flow_dissector_key_meta {
209 	int ingress_ifindex;
210 };
211 
212 /**
213  * struct flow_dissector_key_ct:
214  * @ct_state: conntrack state after converting with map
215  * @ct_mark: conttrack mark
216  * @ct_zone: conntrack zone
217  * @ct_labels: conntrack labels
218  */
219 struct flow_dissector_key_ct {
220 	u16	ct_state;
221 	u16	ct_zone;
222 	u32	ct_mark;
223 	u32	ct_labels[4];
224 };
225 
226 enum flow_dissector_key_id {
227 	FLOW_DISSECTOR_KEY_CONTROL, /* struct flow_dissector_key_control */
228 	FLOW_DISSECTOR_KEY_BASIC, /* struct flow_dissector_key_basic */
229 	FLOW_DISSECTOR_KEY_IPV4_ADDRS, /* struct flow_dissector_key_ipv4_addrs */
230 	FLOW_DISSECTOR_KEY_IPV6_ADDRS, /* struct flow_dissector_key_ipv6_addrs */
231 	FLOW_DISSECTOR_KEY_PORTS, /* struct flow_dissector_key_ports */
232 	FLOW_DISSECTOR_KEY_ICMP, /* struct flow_dissector_key_icmp */
233 	FLOW_DISSECTOR_KEY_ETH_ADDRS, /* struct flow_dissector_key_eth_addrs */
234 	FLOW_DISSECTOR_KEY_TIPC, /* struct flow_dissector_key_tipc */
235 	FLOW_DISSECTOR_KEY_ARP, /* struct flow_dissector_key_arp */
236 	FLOW_DISSECTOR_KEY_VLAN, /* struct flow_dissector_key_vlan */
237 	FLOW_DISSECTOR_KEY_FLOW_LABEL, /* struct flow_dissector_key_tags */
238 	FLOW_DISSECTOR_KEY_GRE_KEYID, /* struct flow_dissector_key_keyid */
239 	FLOW_DISSECTOR_KEY_MPLS_ENTROPY, /* struct flow_dissector_key_keyid */
240 	FLOW_DISSECTOR_KEY_ENC_KEYID, /* struct flow_dissector_key_keyid */
241 	FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS, /* struct flow_dissector_key_ipv4_addrs */
242 	FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS, /* struct flow_dissector_key_ipv6_addrs */
243 	FLOW_DISSECTOR_KEY_ENC_CONTROL, /* struct flow_dissector_key_control */
244 	FLOW_DISSECTOR_KEY_ENC_PORTS, /* struct flow_dissector_key_ports */
245 	FLOW_DISSECTOR_KEY_MPLS, /* struct flow_dissector_key_mpls */
246 	FLOW_DISSECTOR_KEY_TCP, /* struct flow_dissector_key_tcp */
247 	FLOW_DISSECTOR_KEY_IP, /* struct flow_dissector_key_ip */
248 	FLOW_DISSECTOR_KEY_CVLAN, /* struct flow_dissector_key_vlan */
249 	FLOW_DISSECTOR_KEY_ENC_IP, /* struct flow_dissector_key_ip */
250 	FLOW_DISSECTOR_KEY_ENC_OPTS, /* struct flow_dissector_key_enc_opts */
251 	FLOW_DISSECTOR_KEY_META, /* struct flow_dissector_key_meta */
252 	FLOW_DISSECTOR_KEY_CT, /* struct flow_dissector_key_ct */
253 
254 	FLOW_DISSECTOR_KEY_MAX,
255 };
256 
257 #define FLOW_DISSECTOR_F_PARSE_1ST_FRAG		BIT(0)
258 #define FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL	BIT(1)
259 #define FLOW_DISSECTOR_F_STOP_AT_ENCAP		BIT(2)
260 
261 struct flow_dissector_key {
262 	enum flow_dissector_key_id key_id;
263 	size_t offset; /* offset of struct flow_dissector_key_*
264 			  in target the struct */
265 };
266 
267 struct flow_dissector {
268 	unsigned int used_keys; /* each bit repesents presence of one key id */
269 	unsigned short int offset[FLOW_DISSECTOR_KEY_MAX];
270 };
271 
272 struct flow_keys_basic {
273 	struct flow_dissector_key_control control;
274 	struct flow_dissector_key_basic basic;
275 };
276 
277 struct flow_keys {
278 	struct flow_dissector_key_control control;
279 #define FLOW_KEYS_HASH_START_FIELD basic
280 	struct flow_dissector_key_basic basic __aligned(SIPHASH_ALIGNMENT);
281 	struct flow_dissector_key_tags tags;
282 	struct flow_dissector_key_vlan vlan;
283 	struct flow_dissector_key_vlan cvlan;
284 	struct flow_dissector_key_keyid keyid;
285 	struct flow_dissector_key_ports ports;
286 	struct flow_dissector_key_addrs addrs;
287 };
288 
289 #define FLOW_KEYS_HASH_OFFSET		\
290 	offsetof(struct flow_keys, FLOW_KEYS_HASH_START_FIELD)
291 
292 __be32 flow_get_u32_src(const struct flow_keys *flow);
293 __be32 flow_get_u32_dst(const struct flow_keys *flow);
294 
295 extern struct flow_dissector flow_keys_dissector;
296 extern struct flow_dissector flow_keys_basic_dissector;
297 
298 /* struct flow_keys_digest:
299  *
300  * This structure is used to hold a digest of the full flow keys. This is a
301  * larger "hash" of a flow to allow definitively matching specific flows where
302  * the 32 bit skb->hash is not large enough. The size is limited to 16 bytes so
303  * that it can be used in CB of skb (see sch_choke for an example).
304  */
305 #define FLOW_KEYS_DIGEST_LEN	16
306 struct flow_keys_digest {
307 	u8	data[FLOW_KEYS_DIGEST_LEN];
308 };
309 
310 void make_flow_keys_digest(struct flow_keys_digest *digest,
311 			   const struct flow_keys *flow);
312 
313 static inline bool flow_keys_have_l4(const struct flow_keys *keys)
314 {
315 	return (keys->ports.ports || keys->tags.flow_label);
316 }
317 
318 u32 flow_hash_from_keys(struct flow_keys *keys);
319 
320 static inline bool dissector_uses_key(const struct flow_dissector *flow_dissector,
321 				      enum flow_dissector_key_id key_id)
322 {
323 	return flow_dissector->used_keys & (1 << key_id);
324 }
325 
326 static inline void *skb_flow_dissector_target(struct flow_dissector *flow_dissector,
327 					      enum flow_dissector_key_id key_id,
328 					      void *target_container)
329 {
330 	return ((char *)target_container) + flow_dissector->offset[key_id];
331 }
332 
333 struct bpf_flow_dissector {
334 	struct bpf_flow_keys	*flow_keys;
335 	const struct sk_buff	*skb;
336 	void			*data;
337 	void			*data_end;
338 };
339 
340 #endif
341