xref: /linux-6.15/include/uapi/linux/bpf.h (revision 5fd003f5)
1 /* Copyright (c) 2011-2014 PLUMgrid, http://plumgrid.com
2  *
3  * This program is free software; you can redistribute it and/or
4  * modify it under the terms of version 2 of the GNU General Public
5  * License as published by the Free Software Foundation.
6  */
7 #ifndef _UAPI__LINUX_BPF_H__
8 #define _UAPI__LINUX_BPF_H__
9 
10 #include <linux/types.h>
11 #include <linux/bpf_common.h>
12 
13 /* Extended instruction set based on top of classic BPF */
14 
15 /* instruction classes */
16 #define BPF_ALU64	0x07	/* alu mode in double word width */
17 
18 /* ld/ldx fields */
19 #define BPF_DW		0x18	/* double word */
20 #define BPF_XADD	0xc0	/* exclusive add */
21 
22 /* alu/jmp fields */
23 #define BPF_MOV		0xb0	/* mov reg to reg */
24 #define BPF_ARSH	0xc0	/* sign extending arithmetic shift right */
25 
26 /* change endianness of a register */
27 #define BPF_END		0xd0	/* flags for endianness conversion: */
28 #define BPF_TO_LE	0x00	/* convert to little-endian */
29 #define BPF_TO_BE	0x08	/* convert to big-endian */
30 #define BPF_FROM_LE	BPF_TO_LE
31 #define BPF_FROM_BE	BPF_TO_BE
32 
33 #define BPF_JNE		0x50	/* jump != */
34 #define BPF_JSGT	0x60	/* SGT is signed '>', GT in x86 */
35 #define BPF_JSGE	0x70	/* SGE is signed '>=', GE in x86 */
36 #define BPF_CALL	0x80	/* function call */
37 #define BPF_EXIT	0x90	/* function return */
38 
39 /* Register numbers */
40 enum {
41 	BPF_REG_0 = 0,
42 	BPF_REG_1,
43 	BPF_REG_2,
44 	BPF_REG_3,
45 	BPF_REG_4,
46 	BPF_REG_5,
47 	BPF_REG_6,
48 	BPF_REG_7,
49 	BPF_REG_8,
50 	BPF_REG_9,
51 	BPF_REG_10,
52 	__MAX_BPF_REG,
53 };
54 
55 /* BPF has 10 general purpose 64-bit registers and stack frame. */
56 #define MAX_BPF_REG	__MAX_BPF_REG
57 
58 struct bpf_insn {
59 	__u8	code;		/* opcode */
60 	__u8	dst_reg:4;	/* dest register */
61 	__u8	src_reg:4;	/* source register */
62 	__s16	off;		/* signed offset */
63 	__s32	imm;		/* signed immediate constant */
64 };
65 
66 /* BPF syscall commands, see bpf(2) man-page for details. */
67 enum bpf_cmd {
68 	BPF_MAP_CREATE,
69 	BPF_MAP_LOOKUP_ELEM,
70 	BPF_MAP_UPDATE_ELEM,
71 	BPF_MAP_DELETE_ELEM,
72 	BPF_MAP_GET_NEXT_KEY,
73 	BPF_PROG_LOAD,
74 	BPF_OBJ_PIN,
75 	BPF_OBJ_GET,
76 };
77 
78 enum bpf_map_type {
79 	BPF_MAP_TYPE_UNSPEC,
80 	BPF_MAP_TYPE_HASH,
81 	BPF_MAP_TYPE_ARRAY,
82 	BPF_MAP_TYPE_PROG_ARRAY,
83 	BPF_MAP_TYPE_PERF_EVENT_ARRAY,
84 	BPF_MAP_TYPE_PERCPU_HASH,
85 	BPF_MAP_TYPE_PERCPU_ARRAY,
86 };
87 
88 enum bpf_prog_type {
89 	BPF_PROG_TYPE_UNSPEC,
90 	BPF_PROG_TYPE_SOCKET_FILTER,
91 	BPF_PROG_TYPE_KPROBE,
92 	BPF_PROG_TYPE_SCHED_CLS,
93 	BPF_PROG_TYPE_SCHED_ACT,
94 };
95 
96 #define BPF_PSEUDO_MAP_FD	1
97 
98 /* flags for BPF_MAP_UPDATE_ELEM command */
99 #define BPF_ANY		0 /* create new element or update existing */
100 #define BPF_NOEXIST	1 /* create new element if it didn't exist */
101 #define BPF_EXIST	2 /* update existing element */
102 
103 union bpf_attr {
104 	struct { /* anonymous struct used by BPF_MAP_CREATE command */
105 		__u32	map_type;	/* one of enum bpf_map_type */
106 		__u32	key_size;	/* size of key in bytes */
107 		__u32	value_size;	/* size of value in bytes */
108 		__u32	max_entries;	/* max number of entries in a map */
109 	};
110 
111 	struct { /* anonymous struct used by BPF_MAP_*_ELEM commands */
112 		__u32		map_fd;
113 		__aligned_u64	key;
114 		union {
115 			__aligned_u64 value;
116 			__aligned_u64 next_key;
117 		};
118 		__u64		flags;
119 	};
120 
121 	struct { /* anonymous struct used by BPF_PROG_LOAD command */
122 		__u32		prog_type;	/* one of enum bpf_prog_type */
123 		__u32		insn_cnt;
124 		__aligned_u64	insns;
125 		__aligned_u64	license;
126 		__u32		log_level;	/* verbosity level of verifier */
127 		__u32		log_size;	/* size of user buffer */
128 		__aligned_u64	log_buf;	/* user supplied buffer */
129 		__u32		kern_version;	/* checked when prog_type=kprobe */
130 	};
131 
132 	struct { /* anonymous struct used by BPF_OBJ_* commands */
133 		__aligned_u64	pathname;
134 		__u32		bpf_fd;
135 	};
136 } __attribute__((aligned(8)));
137 
138 /* integer value in 'imm' field of BPF_CALL instruction selects which helper
139  * function eBPF program intends to call
140  */
141 enum bpf_func_id {
142 	BPF_FUNC_unspec,
143 	BPF_FUNC_map_lookup_elem, /* void *map_lookup_elem(&map, &key) */
144 	BPF_FUNC_map_update_elem, /* int map_update_elem(&map, &key, &value, flags) */
145 	BPF_FUNC_map_delete_elem, /* int map_delete_elem(&map, &key) */
146 	BPF_FUNC_probe_read,      /* int bpf_probe_read(void *dst, int size, void *src) */
147 	BPF_FUNC_ktime_get_ns,    /* u64 bpf_ktime_get_ns(void) */
148 	BPF_FUNC_trace_printk,    /* int bpf_trace_printk(const char *fmt, int fmt_size, ...) */
149 	BPF_FUNC_get_prandom_u32, /* u32 prandom_u32(void) */
150 	BPF_FUNC_get_smp_processor_id, /* u32 raw_smp_processor_id(void) */
151 
152 	/**
153 	 * skb_store_bytes(skb, offset, from, len, flags) - store bytes into packet
154 	 * @skb: pointer to skb
155 	 * @offset: offset within packet from skb->mac_header
156 	 * @from: pointer where to copy bytes from
157 	 * @len: number of bytes to store into packet
158 	 * @flags: bit 0 - if true, recompute skb->csum
159 	 *         other bits - reserved
160 	 * Return: 0 on success
161 	 */
162 	BPF_FUNC_skb_store_bytes,
163 
164 	/**
165 	 * l3_csum_replace(skb, offset, from, to, flags) - recompute IP checksum
166 	 * @skb: pointer to skb
167 	 * @offset: offset within packet where IP checksum is located
168 	 * @from: old value of header field
169 	 * @to: new value of header field
170 	 * @flags: bits 0-3 - size of header field
171 	 *         other bits - reserved
172 	 * Return: 0 on success
173 	 */
174 	BPF_FUNC_l3_csum_replace,
175 
176 	/**
177 	 * l4_csum_replace(skb, offset, from, to, flags) - recompute TCP/UDP checksum
178 	 * @skb: pointer to skb
179 	 * @offset: offset within packet where TCP/UDP checksum is located
180 	 * @from: old value of header field
181 	 * @to: new value of header field
182 	 * @flags: bits 0-3 - size of header field
183 	 *         bit 4 - is pseudo header
184 	 *         other bits - reserved
185 	 * Return: 0 on success
186 	 */
187 	BPF_FUNC_l4_csum_replace,
188 
189 	/**
190 	 * bpf_tail_call(ctx, prog_array_map, index) - jump into another BPF program
191 	 * @ctx: context pointer passed to next program
192 	 * @prog_array_map: pointer to map which type is BPF_MAP_TYPE_PROG_ARRAY
193 	 * @index: index inside array that selects specific program to run
194 	 * Return: 0 on success
195 	 */
196 	BPF_FUNC_tail_call,
197 
198 	/**
199 	 * bpf_clone_redirect(skb, ifindex, flags) - redirect to another netdev
200 	 * @skb: pointer to skb
201 	 * @ifindex: ifindex of the net device
202 	 * @flags: bit 0 - if set, redirect to ingress instead of egress
203 	 *         other bits - reserved
204 	 * Return: 0 on success
205 	 */
206 	BPF_FUNC_clone_redirect,
207 
208 	/**
209 	 * u64 bpf_get_current_pid_tgid(void)
210 	 * Return: current->tgid << 32 | current->pid
211 	 */
212 	BPF_FUNC_get_current_pid_tgid,
213 
214 	/**
215 	 * u64 bpf_get_current_uid_gid(void)
216 	 * Return: current_gid << 32 | current_uid
217 	 */
218 	BPF_FUNC_get_current_uid_gid,
219 
220 	/**
221 	 * bpf_get_current_comm(char *buf, int size_of_buf)
222 	 * stores current->comm into buf
223 	 * Return: 0 on success
224 	 */
225 	BPF_FUNC_get_current_comm,
226 
227 	/**
228 	 * bpf_get_cgroup_classid(skb) - retrieve a proc's classid
229 	 * @skb: pointer to skb
230 	 * Return: classid if != 0
231 	 */
232 	BPF_FUNC_get_cgroup_classid,
233 	BPF_FUNC_skb_vlan_push, /* bpf_skb_vlan_push(skb, vlan_proto, vlan_tci) */
234 	BPF_FUNC_skb_vlan_pop,  /* bpf_skb_vlan_pop(skb) */
235 
236 	/**
237 	 * bpf_skb_[gs]et_tunnel_key(skb, key, size, flags)
238 	 * retrieve or populate tunnel metadata
239 	 * @skb: pointer to skb
240 	 * @key: pointer to 'struct bpf_tunnel_key'
241 	 * @size: size of 'struct bpf_tunnel_key'
242 	 * @flags: room for future extensions
243 	 * Retrun: 0 on success
244 	 */
245 	BPF_FUNC_skb_get_tunnel_key,
246 	BPF_FUNC_skb_set_tunnel_key,
247 	BPF_FUNC_perf_event_read,	/* u64 bpf_perf_event_read(&map, index) */
248 	/**
249 	 * bpf_redirect(ifindex, flags) - redirect to another netdev
250 	 * @ifindex: ifindex of the net device
251 	 * @flags: bit 0 - if set, redirect to ingress instead of egress
252 	 *         other bits - reserved
253 	 * Return: TC_ACT_REDIRECT
254 	 */
255 	BPF_FUNC_redirect,
256 
257 	/**
258 	 * bpf_get_route_realm(skb) - retrieve a dst's tclassid
259 	 * @skb: pointer to skb
260 	 * Return: realm if != 0
261 	 */
262 	BPF_FUNC_get_route_realm,
263 
264 	/**
265 	 * bpf_perf_event_output(ctx, map, index, data, size) - output perf raw sample
266 	 * @ctx: struct pt_regs*
267 	 * @map: pointer to perf_event_array map
268 	 * @index: index of event in the map
269 	 * @data: data on stack to be output as raw data
270 	 * @size: size of data
271 	 * Return: 0 on success
272 	 */
273 	BPF_FUNC_perf_event_output,
274 	BPF_FUNC_skb_load_bytes,
275 	__BPF_FUNC_MAX_ID,
276 };
277 
278 /* All flags used by eBPF helper functions, placed here. */
279 
280 /* BPF_FUNC_skb_store_bytes flags. */
281 #define BPF_F_RECOMPUTE_CSUM		(1ULL << 0)
282 
283 /* BPF_FUNC_l3_csum_replace and BPF_FUNC_l4_csum_replace flags.
284  * First 4 bits are for passing the header field size.
285  */
286 #define BPF_F_HDR_FIELD_MASK		0xfULL
287 
288 /* BPF_FUNC_l4_csum_replace flags. */
289 #define BPF_F_PSEUDO_HDR		(1ULL << 4)
290 
291 /* BPF_FUNC_clone_redirect and BPF_FUNC_redirect flags. */
292 #define BPF_F_INGRESS			(1ULL << 0)
293 
294 /* BPF_FUNC_skb_set_tunnel_key and BPF_FUNC_skb_get_tunnel_key flags. */
295 #define BPF_F_TUNINFO_IPV6		(1ULL << 0)
296 
297 /* user accessible mirror of in-kernel sk_buff.
298  * new fields can only be added to the end of this structure
299  */
300 struct __sk_buff {
301 	__u32 len;
302 	__u32 pkt_type;
303 	__u32 mark;
304 	__u32 queue_mapping;
305 	__u32 protocol;
306 	__u32 vlan_present;
307 	__u32 vlan_tci;
308 	__u32 vlan_proto;
309 	__u32 priority;
310 	__u32 ingress_ifindex;
311 	__u32 ifindex;
312 	__u32 tc_index;
313 	__u32 cb[5];
314 	__u32 hash;
315 	__u32 tc_classid;
316 };
317 
318 struct bpf_tunnel_key {
319 	__u32 tunnel_id;
320 	union {
321 		__u32 remote_ipv4;
322 		__u32 remote_ipv6[4];
323 	};
324 	__u8 tunnel_tos;
325 	__u8 tunnel_ttl;
326 };
327 
328 #endif /* _UAPI__LINUX_BPF_H__ */
329