xref: /linux/include/net/flow_dissector.h (revision 3a755ebcc2557e22b895b8976257f682c653db1d)
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 <linux/string.h>
9 #include <uapi/linux/if_ether.h>
10 
11 struct bpf_prog;
12 struct net;
13 struct sk_buff;
14 
15 /**
16  * struct flow_dissector_key_control:
17  * @thoff: Transport header offset
18  */
19 struct flow_dissector_key_control {
20 	u16	thoff;
21 	u16	addr_type;
22 	u32	flags;
23 };
24 
25 #define FLOW_DIS_IS_FRAGMENT	BIT(0)
26 #define FLOW_DIS_FIRST_FRAG	BIT(1)
27 #define FLOW_DIS_ENCAPSULATION	BIT(2)
28 
29 enum flow_dissect_ret {
30 	FLOW_DISSECT_RET_OUT_GOOD,
31 	FLOW_DISSECT_RET_OUT_BAD,
32 	FLOW_DISSECT_RET_PROTO_AGAIN,
33 	FLOW_DISSECT_RET_IPPROTO_AGAIN,
34 	FLOW_DISSECT_RET_CONTINUE,
35 };
36 
37 /**
38  * struct flow_dissector_key_basic:
39  * @n_proto: Network header protocol (eg. IPv4/IPv6)
40  * @ip_proto: Transport header protocol (eg. TCP/UDP)
41  */
42 struct flow_dissector_key_basic {
43 	__be16	n_proto;
44 	u8	ip_proto;
45 	u8	padding;
46 };
47 
48 struct flow_dissector_key_tags {
49 	u32	flow_label;
50 };
51 
52 struct flow_dissector_key_vlan {
53 	union {
54 		struct {
55 			u16	vlan_id:12,
56 				vlan_dei:1,
57 				vlan_priority:3;
58 		};
59 		__be16	vlan_tci;
60 	};
61 	__be16	vlan_tpid;
62 	__be16	vlan_eth_type;
63 	u16	padding;
64 };
65 
66 struct flow_dissector_mpls_lse {
67 	u32	mpls_ttl:8,
68 		mpls_bos:1,
69 		mpls_tc:3,
70 		mpls_label:20;
71 };
72 
73 #define FLOW_DIS_MPLS_MAX 7
74 struct flow_dissector_key_mpls {
75 	struct flow_dissector_mpls_lse ls[FLOW_DIS_MPLS_MAX]; /* Label Stack */
76 	u8 used_lses; /* One bit set for each Label Stack Entry in use */
77 };
78 
79 static inline void dissector_set_mpls_lse(struct flow_dissector_key_mpls *mpls,
80 					  int lse_index)
81 {
82 	mpls->used_lses |= 1 << lse_index;
83 }
84 
85 #define FLOW_DIS_TUN_OPTS_MAX 255
86 /**
87  * struct flow_dissector_key_enc_opts:
88  * @data: tunnel option data
89  * @len: length of tunnel option data
90  * @dst_opt_type: tunnel option type
91  */
92 struct flow_dissector_key_enc_opts {
93 	u8 data[FLOW_DIS_TUN_OPTS_MAX];	/* Using IP_TUNNEL_OPTS_MAX is desired
94 					 * here but seems difficult to #include
95 					 */
96 	u8 len;
97 	__be16 dst_opt_type;
98 };
99 
100 struct flow_dissector_key_keyid {
101 	__be32	keyid;
102 };
103 
104 /**
105  * struct flow_dissector_key_ipv4_addrs:
106  * @src: source ip address
107  * @dst: destination ip address
108  */
109 struct flow_dissector_key_ipv4_addrs {
110 	/* (src,dst) must be grouped, in the same way than in IP header */
111 	__be32 src;
112 	__be32 dst;
113 };
114 
115 /**
116  * struct flow_dissector_key_ipv6_addrs:
117  * @src: source ip address
118  * @dst: destination ip address
119  */
120 struct flow_dissector_key_ipv6_addrs {
121 	/* (src,dst) must be grouped, in the same way than in IP header */
122 	struct in6_addr src;
123 	struct in6_addr dst;
124 };
125 
126 /**
127  * struct flow_dissector_key_tipc:
128  * @key: source node address combined with selector
129  */
130 struct flow_dissector_key_tipc {
131 	__be32 key;
132 };
133 
134 /**
135  * struct flow_dissector_key_addrs:
136  * @v4addrs: IPv4 addresses
137  * @v6addrs: IPv6 addresses
138  */
139 struct flow_dissector_key_addrs {
140 	union {
141 		struct flow_dissector_key_ipv4_addrs v4addrs;
142 		struct flow_dissector_key_ipv6_addrs v6addrs;
143 		struct flow_dissector_key_tipc tipckey;
144 	};
145 };
146 
147 /**
148  * flow_dissector_key_arp:
149  *	@ports: Operation, source and target addresses for an ARP header
150  *              for Ethernet hardware addresses and IPv4 protocol addresses
151  *		sip: Sender IP address
152  *		tip: Target IP address
153  *		op:  Operation
154  *		sha: Sender hardware address
155  *		tpa: Target hardware address
156  */
157 struct flow_dissector_key_arp {
158 	__u32 sip;
159 	__u32 tip;
160 	__u8 op;
161 	unsigned char sha[ETH_ALEN];
162 	unsigned char tha[ETH_ALEN];
163 };
164 
165 /**
166  * flow_dissector_key_tp_ports:
167  *	@ports: port numbers of Transport header
168  *		src: source port number
169  *		dst: destination port number
170  */
171 struct flow_dissector_key_ports {
172 	union {
173 		__be32 ports;
174 		struct {
175 			__be16 src;
176 			__be16 dst;
177 		};
178 	};
179 };
180 
181 /**
182  * flow_dissector_key_icmp:
183  *		type: ICMP type
184  *		code: ICMP code
185  *		id:   session identifier
186  */
187 struct flow_dissector_key_icmp {
188 	struct {
189 		u8 type;
190 		u8 code;
191 	};
192 	u16 id;
193 };
194 
195 /**
196  * struct flow_dissector_key_eth_addrs:
197  * @src: source Ethernet address
198  * @dst: destination Ethernet address
199  */
200 struct flow_dissector_key_eth_addrs {
201 	/* (dst,src) must be grouped, in the same way than in ETH header */
202 	unsigned char dst[ETH_ALEN];
203 	unsigned char src[ETH_ALEN];
204 };
205 
206 /**
207  * struct flow_dissector_key_tcp:
208  * @flags: flags
209  */
210 struct flow_dissector_key_tcp {
211 	__be16 flags;
212 };
213 
214 /**
215  * struct flow_dissector_key_ip:
216  * @tos: tos
217  * @ttl: ttl
218  */
219 struct flow_dissector_key_ip {
220 	__u8	tos;
221 	__u8	ttl;
222 };
223 
224 /**
225  * struct flow_dissector_key_meta:
226  * @ingress_ifindex: ingress ifindex
227  * @ingress_iftype: ingress interface type
228  */
229 struct flow_dissector_key_meta {
230 	int ingress_ifindex;
231 	u16 ingress_iftype;
232 };
233 
234 /**
235  * struct flow_dissector_key_ct:
236  * @ct_state: conntrack state after converting with map
237  * @ct_mark: conttrack mark
238  * @ct_zone: conntrack zone
239  * @ct_labels: conntrack labels
240  */
241 struct flow_dissector_key_ct {
242 	u16	ct_state;
243 	u16	ct_zone;
244 	u32	ct_mark;
245 	u32	ct_labels[4];
246 };
247 
248 /**
249  * struct flow_dissector_key_hash:
250  * @hash: hash value
251  */
252 struct flow_dissector_key_hash {
253 	u32 hash;
254 };
255 
256 enum flow_dissector_key_id {
257 	FLOW_DISSECTOR_KEY_CONTROL, /* struct flow_dissector_key_control */
258 	FLOW_DISSECTOR_KEY_BASIC, /* struct flow_dissector_key_basic */
259 	FLOW_DISSECTOR_KEY_IPV4_ADDRS, /* struct flow_dissector_key_ipv4_addrs */
260 	FLOW_DISSECTOR_KEY_IPV6_ADDRS, /* struct flow_dissector_key_ipv6_addrs */
261 	FLOW_DISSECTOR_KEY_PORTS, /* struct flow_dissector_key_ports */
262 	FLOW_DISSECTOR_KEY_PORTS_RANGE, /* struct flow_dissector_key_ports */
263 	FLOW_DISSECTOR_KEY_ICMP, /* struct flow_dissector_key_icmp */
264 	FLOW_DISSECTOR_KEY_ETH_ADDRS, /* struct flow_dissector_key_eth_addrs */
265 	FLOW_DISSECTOR_KEY_TIPC, /* struct flow_dissector_key_tipc */
266 	FLOW_DISSECTOR_KEY_ARP, /* struct flow_dissector_key_arp */
267 	FLOW_DISSECTOR_KEY_VLAN, /* struct flow_dissector_key_vlan */
268 	FLOW_DISSECTOR_KEY_FLOW_LABEL, /* struct flow_dissector_key_tags */
269 	FLOW_DISSECTOR_KEY_GRE_KEYID, /* struct flow_dissector_key_keyid */
270 	FLOW_DISSECTOR_KEY_MPLS_ENTROPY, /* struct flow_dissector_key_keyid */
271 	FLOW_DISSECTOR_KEY_ENC_KEYID, /* struct flow_dissector_key_keyid */
272 	FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS, /* struct flow_dissector_key_ipv4_addrs */
273 	FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS, /* struct flow_dissector_key_ipv6_addrs */
274 	FLOW_DISSECTOR_KEY_ENC_CONTROL, /* struct flow_dissector_key_control */
275 	FLOW_DISSECTOR_KEY_ENC_PORTS, /* struct flow_dissector_key_ports */
276 	FLOW_DISSECTOR_KEY_MPLS, /* struct flow_dissector_key_mpls */
277 	FLOW_DISSECTOR_KEY_TCP, /* struct flow_dissector_key_tcp */
278 	FLOW_DISSECTOR_KEY_IP, /* struct flow_dissector_key_ip */
279 	FLOW_DISSECTOR_KEY_CVLAN, /* struct flow_dissector_key_vlan */
280 	FLOW_DISSECTOR_KEY_ENC_IP, /* struct flow_dissector_key_ip */
281 	FLOW_DISSECTOR_KEY_ENC_OPTS, /* struct flow_dissector_key_enc_opts */
282 	FLOW_DISSECTOR_KEY_META, /* struct flow_dissector_key_meta */
283 	FLOW_DISSECTOR_KEY_CT, /* struct flow_dissector_key_ct */
284 	FLOW_DISSECTOR_KEY_HASH, /* struct flow_dissector_key_hash */
285 
286 	FLOW_DISSECTOR_KEY_MAX,
287 };
288 
289 #define FLOW_DISSECTOR_F_PARSE_1ST_FRAG		BIT(0)
290 #define FLOW_DISSECTOR_F_STOP_AT_FLOW_LABEL	BIT(1)
291 #define FLOW_DISSECTOR_F_STOP_AT_ENCAP		BIT(2)
292 #define FLOW_DISSECTOR_F_STOP_BEFORE_ENCAP	BIT(3)
293 
294 struct flow_dissector_key {
295 	enum flow_dissector_key_id key_id;
296 	size_t offset; /* offset of struct flow_dissector_key_*
297 			  in target the struct */
298 };
299 
300 struct flow_dissector {
301 	unsigned int used_keys; /* each bit repesents presence of one key id */
302 	unsigned short int offset[FLOW_DISSECTOR_KEY_MAX];
303 };
304 
305 struct flow_keys_basic {
306 	struct flow_dissector_key_control control;
307 	struct flow_dissector_key_basic basic;
308 };
309 
310 struct flow_keys {
311 	struct flow_dissector_key_control control;
312 #define FLOW_KEYS_HASH_START_FIELD basic
313 	struct flow_dissector_key_basic basic __aligned(SIPHASH_ALIGNMENT);
314 	struct flow_dissector_key_tags tags;
315 	struct flow_dissector_key_vlan vlan;
316 	struct flow_dissector_key_vlan cvlan;
317 	struct flow_dissector_key_keyid keyid;
318 	struct flow_dissector_key_ports ports;
319 	struct flow_dissector_key_icmp icmp;
320 	/* 'addrs' must be the last member */
321 	struct flow_dissector_key_addrs addrs;
322 };
323 
324 #define FLOW_KEYS_HASH_OFFSET		\
325 	offsetof(struct flow_keys, FLOW_KEYS_HASH_START_FIELD)
326 
327 __be32 flow_get_u32_src(const struct flow_keys *flow);
328 __be32 flow_get_u32_dst(const struct flow_keys *flow);
329 
330 extern struct flow_dissector flow_keys_dissector;
331 extern struct flow_dissector flow_keys_basic_dissector;
332 
333 /* struct flow_keys_digest:
334  *
335  * This structure is used to hold a digest of the full flow keys. This is a
336  * larger "hash" of a flow to allow definitively matching specific flows where
337  * the 32 bit skb->hash is not large enough. The size is limited to 16 bytes so
338  * that it can be used in CB of skb (see sch_choke for an example).
339  */
340 #define FLOW_KEYS_DIGEST_LEN	16
341 struct flow_keys_digest {
342 	u8	data[FLOW_KEYS_DIGEST_LEN];
343 };
344 
345 void make_flow_keys_digest(struct flow_keys_digest *digest,
346 			   const struct flow_keys *flow);
347 
348 static inline bool flow_keys_have_l4(const struct flow_keys *keys)
349 {
350 	return (keys->ports.ports || keys->tags.flow_label);
351 }
352 
353 u32 flow_hash_from_keys(struct flow_keys *keys);
354 void skb_flow_get_icmp_tci(const struct sk_buff *skb,
355 			   struct flow_dissector_key_icmp *key_icmp,
356 			   const void *data, int thoff, int hlen);
357 
358 static inline bool dissector_uses_key(const struct flow_dissector *flow_dissector,
359 				      enum flow_dissector_key_id key_id)
360 {
361 	return flow_dissector->used_keys & (1 << key_id);
362 }
363 
364 static inline void *skb_flow_dissector_target(struct flow_dissector *flow_dissector,
365 					      enum flow_dissector_key_id key_id,
366 					      void *target_container)
367 {
368 	return ((char *)target_container) + flow_dissector->offset[key_id];
369 }
370 
371 struct bpf_flow_dissector {
372 	struct bpf_flow_keys	*flow_keys;
373 	const struct sk_buff	*skb;
374 	const void		*data;
375 	const void		*data_end;
376 };
377 
378 static inline void
379 flow_dissector_init_keys(struct flow_dissector_key_control *key_control,
380 			 struct flow_dissector_key_basic *key_basic)
381 {
382 	memset(key_control, 0, sizeof(*key_control));
383 	memset(key_basic, 0, sizeof(*key_basic));
384 }
385 
386 #ifdef CONFIG_BPF_SYSCALL
387 int flow_dissector_bpf_prog_attach_check(struct net *net,
388 					 struct bpf_prog *prog);
389 #endif /* CONFIG_BPF_SYSCALL */
390 
391 #endif
392