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