bpf.h 17 KB

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  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. #include <linux/types.h>
  10. #include <linux/bpf_common.h>
  11. /* Extended instruction set based on top of classic BPF */
  12. /* instruction classes */
  13. #define BPF_ALU64 0x07 /* alu mode in double word width */
  14. /* ld/ldx fields */
  15. #define BPF_DW 0x18 /* double word */
  16. #define BPF_XADD 0xc0 /* exclusive add */
  17. /* alu/jmp fields */
  18. #define BPF_MOV 0xb0 /* mov reg to reg */
  19. #define BPF_ARSH 0xc0 /* sign extending arithmetic shift right */
  20. /* change endianness of a register */
  21. #define BPF_END 0xd0 /* flags for endianness conversion: */
  22. #define BPF_TO_LE 0x00 /* convert to little-endian */
  23. #define BPF_TO_BE 0x08 /* convert to big-endian */
  24. #define BPF_FROM_LE BPF_TO_LE
  25. #define BPF_FROM_BE BPF_TO_BE
  26. #define BPF_JNE 0x50 /* jump != */
  27. #define BPF_JSGT 0x60 /* SGT is signed '>', GT in x86 */
  28. #define BPF_JSGE 0x70 /* SGE is signed '>=', GE in x86 */
  29. #define BPF_CALL 0x80 /* function call */
  30. #define BPF_EXIT 0x90 /* function return */
  31. /* Register numbers */
  32. enum {
  33. BPF_REG_0 = 0,
  34. BPF_REG_1,
  35. BPF_REG_2,
  36. BPF_REG_3,
  37. BPF_REG_4,
  38. BPF_REG_5,
  39. BPF_REG_6,
  40. BPF_REG_7,
  41. BPF_REG_8,
  42. BPF_REG_9,
  43. BPF_REG_10,
  44. __MAX_BPF_REG,
  45. };
  46. /* BPF has 10 general purpose 64-bit registers and stack frame. */
  47. #define MAX_BPF_REG __MAX_BPF_REG
  48. struct bpf_insn {
  49. __u8 code; /* opcode */
  50. __u8 dst_reg:4; /* dest register */
  51. __u8 src_reg:4; /* source register */
  52. __s16 off; /* signed offset */
  53. __s32 imm; /* signed immediate constant */
  54. };
  55. /* BPF syscall commands, see bpf(2) man-page for details. */
  56. enum bpf_cmd {
  57. BPF_MAP_CREATE,
  58. BPF_MAP_LOOKUP_ELEM,
  59. BPF_MAP_UPDATE_ELEM,
  60. BPF_MAP_DELETE_ELEM,
  61. BPF_MAP_GET_NEXT_KEY,
  62. BPF_PROG_LOAD,
  63. BPF_OBJ_PIN,
  64. BPF_OBJ_GET,
  65. BPF_PROG_ATTACH,
  66. BPF_PROG_DETACH,
  67. };
  68. enum bpf_map_type {
  69. BPF_MAP_TYPE_UNSPEC,
  70. BPF_MAP_TYPE_HASH,
  71. BPF_MAP_TYPE_ARRAY,
  72. BPF_MAP_TYPE_PROG_ARRAY,
  73. BPF_MAP_TYPE_PERF_EVENT_ARRAY,
  74. BPF_MAP_TYPE_PERCPU_HASH,
  75. BPF_MAP_TYPE_PERCPU_ARRAY,
  76. BPF_MAP_TYPE_STACK_TRACE,
  77. BPF_MAP_TYPE_CGROUP_ARRAY,
  78. BPF_MAP_TYPE_LRU_HASH,
  79. BPF_MAP_TYPE_LRU_PERCPU_HASH,
  80. };
  81. enum bpf_prog_type {
  82. BPF_PROG_TYPE_UNSPEC,
  83. BPF_PROG_TYPE_SOCKET_FILTER,
  84. BPF_PROG_TYPE_KPROBE,
  85. BPF_PROG_TYPE_SCHED_CLS,
  86. BPF_PROG_TYPE_SCHED_ACT,
  87. BPF_PROG_TYPE_TRACEPOINT,
  88. BPF_PROG_TYPE_XDP,
  89. BPF_PROG_TYPE_PERF_EVENT,
  90. BPF_PROG_TYPE_CGROUP_SKB,
  91. BPF_PROG_TYPE_LWT_IN,
  92. BPF_PROG_TYPE_LWT_OUT,
  93. BPF_PROG_TYPE_LWT_XMIT,
  94. };
  95. enum bpf_attach_type {
  96. BPF_CGROUP_INET_INGRESS,
  97. BPF_CGROUP_INET_EGRESS,
  98. __MAX_BPF_ATTACH_TYPE
  99. };
  100. #define MAX_BPF_ATTACH_TYPE __MAX_BPF_ATTACH_TYPE
  101. #define BPF_PSEUDO_MAP_FD 1
  102. /* flags for BPF_MAP_UPDATE_ELEM command */
  103. #define BPF_ANY 0 /* create new element or update existing */
  104. #define BPF_NOEXIST 1 /* create new element if it didn't exist */
  105. #define BPF_EXIST 2 /* update existing element */
  106. #define BPF_F_NO_PREALLOC (1U << 0)
  107. /* Instead of having one common LRU list in the
  108. * BPF_MAP_TYPE_LRU_[PERCPU_]HASH map, use a percpu LRU list
  109. * which can scale and perform better.
  110. * Note, the LRU nodes (including free nodes) cannot be moved
  111. * across different LRU lists.
  112. */
  113. #define BPF_F_NO_COMMON_LRU (1U << 1)
  114. union bpf_attr {
  115. struct { /* anonymous struct used by BPF_MAP_CREATE command */
  116. __u32 map_type; /* one of enum bpf_map_type */
  117. __u32 key_size; /* size of key in bytes */
  118. __u32 value_size; /* size of value in bytes */
  119. __u32 max_entries; /* max number of entries in a map */
  120. __u32 map_flags; /* prealloc or not */
  121. };
  122. struct { /* anonymous struct used by BPF_MAP_*_ELEM commands */
  123. __u32 map_fd;
  124. __aligned_u64 key;
  125. union {
  126. __aligned_u64 value;
  127. __aligned_u64 next_key;
  128. };
  129. __u64 flags;
  130. };
  131. struct { /* anonymous struct used by BPF_PROG_LOAD command */
  132. __u32 prog_type; /* one of enum bpf_prog_type */
  133. __u32 insn_cnt;
  134. __aligned_u64 insns;
  135. __aligned_u64 license;
  136. __u32 log_level; /* verbosity level of verifier */
  137. __u32 log_size; /* size of user buffer */
  138. __aligned_u64 log_buf; /* user supplied buffer */
  139. __u32 kern_version; /* checked when prog_type=kprobe */
  140. };
  141. struct { /* anonymous struct used by BPF_OBJ_* commands */
  142. __aligned_u64 pathname;
  143. __u32 bpf_fd;
  144. };
  145. struct { /* anonymous struct used by BPF_PROG_ATTACH/DETACH commands */
  146. __u32 target_fd; /* container object to attach to */
  147. __u32 attach_bpf_fd; /* eBPF program to attach */
  148. __u32 attach_type;
  149. };
  150. } __attribute__((aligned(8)));
  151. /* BPF helper function descriptions:
  152. *
  153. * void *bpf_map_lookup_elem(&map, &key)
  154. * Return: Map value or NULL
  155. *
  156. * int bpf_map_update_elem(&map, &key, &value, flags)
  157. * Return: 0 on success or negative error
  158. *
  159. * int bpf_map_delete_elem(&map, &key)
  160. * Return: 0 on success or negative error
  161. *
  162. * int bpf_probe_read(void *dst, int size, void *src)
  163. * Return: 0 on success or negative error
  164. *
  165. * u64 bpf_ktime_get_ns(void)
  166. * Return: current ktime
  167. *
  168. * int bpf_trace_printk(const char *fmt, int fmt_size, ...)
  169. * Return: length of buffer written or negative error
  170. *
  171. * u32 bpf_prandom_u32(void)
  172. * Return: random value
  173. *
  174. * u32 bpf_raw_smp_processor_id(void)
  175. * Return: SMP processor ID
  176. *
  177. * int bpf_skb_store_bytes(skb, offset, from, len, flags)
  178. * store bytes into packet
  179. * @skb: pointer to skb
  180. * @offset: offset within packet from skb->mac_header
  181. * @from: pointer where to copy bytes from
  182. * @len: number of bytes to store into packet
  183. * @flags: bit 0 - if true, recompute skb->csum
  184. * other bits - reserved
  185. * Return: 0 on success or negative error
  186. *
  187. * int bpf_l3_csum_replace(skb, offset, from, to, flags)
  188. * recompute IP checksum
  189. * @skb: pointer to skb
  190. * @offset: offset within packet where IP checksum is located
  191. * @from: old value of header field
  192. * @to: new value of header field
  193. * @flags: bits 0-3 - size of header field
  194. * other bits - reserved
  195. * Return: 0 on success or negative error
  196. *
  197. * int bpf_l4_csum_replace(skb, offset, from, to, flags)
  198. * recompute TCP/UDP checksum
  199. * @skb: pointer to skb
  200. * @offset: offset within packet where TCP/UDP checksum is located
  201. * @from: old value of header field
  202. * @to: new value of header field
  203. * @flags: bits 0-3 - size of header field
  204. * bit 4 - is pseudo header
  205. * other bits - reserved
  206. * Return: 0 on success or negative error
  207. *
  208. * int bpf_tail_call(ctx, prog_array_map, index)
  209. * jump into another BPF program
  210. * @ctx: context pointer passed to next program
  211. * @prog_array_map: pointer to map which type is BPF_MAP_TYPE_PROG_ARRAY
  212. * @index: index inside array that selects specific program to run
  213. * Return: 0 on success or negative error
  214. *
  215. * int bpf_clone_redirect(skb, ifindex, flags)
  216. * redirect to another netdev
  217. * @skb: pointer to skb
  218. * @ifindex: ifindex of the net device
  219. * @flags: bit 0 - if set, redirect to ingress instead of egress
  220. * other bits - reserved
  221. * Return: 0 on success or negative error
  222. *
  223. * u64 bpf_get_current_pid_tgid(void)
  224. * Return: current->tgid << 32 | current->pid
  225. *
  226. * u64 bpf_get_current_uid_gid(void)
  227. * Return: current_gid << 32 | current_uid
  228. *
  229. * int bpf_get_current_comm(char *buf, int size_of_buf)
  230. * stores current->comm into buf
  231. * Return: 0 on success or negative error
  232. *
  233. * u32 bpf_get_cgroup_classid(skb)
  234. * retrieve a proc's classid
  235. * @skb: pointer to skb
  236. * Return: classid if != 0
  237. *
  238. * int bpf_skb_vlan_push(skb, vlan_proto, vlan_tci)
  239. * Return: 0 on success or negative error
  240. *
  241. * int bpf_skb_vlan_pop(skb)
  242. * Return: 0 on success or negative error
  243. *
  244. * int bpf_skb_get_tunnel_key(skb, key, size, flags)
  245. * int bpf_skb_set_tunnel_key(skb, key, size, flags)
  246. * retrieve or populate tunnel metadata
  247. * @skb: pointer to skb
  248. * @key: pointer to 'struct bpf_tunnel_key'
  249. * @size: size of 'struct bpf_tunnel_key'
  250. * @flags: room for future extensions
  251. * Return: 0 on success or negative error
  252. *
  253. * u64 bpf_perf_event_read(&map, index)
  254. * Return: Number events read or error code
  255. *
  256. * int bpf_redirect(ifindex, flags)
  257. * redirect to another netdev
  258. * @ifindex: ifindex of the net device
  259. * @flags: bit 0 - if set, redirect to ingress instead of egress
  260. * other bits - reserved
  261. * Return: TC_ACT_REDIRECT
  262. *
  263. * u32 bpf_get_route_realm(skb)
  264. * retrieve a dst's tclassid
  265. * @skb: pointer to skb
  266. * Return: realm if != 0
  267. *
  268. * int bpf_perf_event_output(ctx, map, index, data, size)
  269. * output perf raw sample
  270. * @ctx: struct pt_regs*
  271. * @map: pointer to perf_event_array map
  272. * @index: index of event in the map
  273. * @data: data on stack to be output as raw data
  274. * @size: size of data
  275. * Return: 0 on success or negative error
  276. *
  277. * int bpf_get_stackid(ctx, map, flags)
  278. * walk user or kernel stack and return id
  279. * @ctx: struct pt_regs*
  280. * @map: pointer to stack_trace map
  281. * @flags: bits 0-7 - numer of stack frames to skip
  282. * bit 8 - collect user stack instead of kernel
  283. * bit 9 - compare stacks by hash only
  284. * bit 10 - if two different stacks hash into the same stackid
  285. * discard old
  286. * other bits - reserved
  287. * Return: >= 0 stackid on success or negative error
  288. *
  289. * s64 bpf_csum_diff(from, from_size, to, to_size, seed)
  290. * calculate csum diff
  291. * @from: raw from buffer
  292. * @from_size: length of from buffer
  293. * @to: raw to buffer
  294. * @to_size: length of to buffer
  295. * @seed: optional seed
  296. * Return: csum result or negative error code
  297. *
  298. * int bpf_skb_get_tunnel_opt(skb, opt, size)
  299. * retrieve tunnel options metadata
  300. * @skb: pointer to skb
  301. * @opt: pointer to raw tunnel option data
  302. * @size: size of @opt
  303. * Return: option size
  304. *
  305. * int bpf_skb_set_tunnel_opt(skb, opt, size)
  306. * populate tunnel options metadata
  307. * @skb: pointer to skb
  308. * @opt: pointer to raw tunnel option data
  309. * @size: size of @opt
  310. * Return: 0 on success or negative error
  311. *
  312. * int bpf_skb_change_proto(skb, proto, flags)
  313. * Change protocol of the skb. Currently supported is v4 -> v6,
  314. * v6 -> v4 transitions. The helper will also resize the skb. eBPF
  315. * program is expected to fill the new headers via skb_store_bytes
  316. * and lX_csum_replace.
  317. * @skb: pointer to skb
  318. * @proto: new skb->protocol type
  319. * @flags: reserved
  320. * Return: 0 on success or negative error
  321. *
  322. * int bpf_skb_change_type(skb, type)
  323. * Change packet type of skb.
  324. * @skb: pointer to skb
  325. * @type: new skb->pkt_type type
  326. * Return: 0 on success or negative error
  327. *
  328. * int bpf_skb_under_cgroup(skb, map, index)
  329. * Check cgroup2 membership of skb
  330. * @skb: pointer to skb
  331. * @map: pointer to bpf_map in BPF_MAP_TYPE_CGROUP_ARRAY type
  332. * @index: index of the cgroup in the bpf_map
  333. * Return:
  334. * == 0 skb failed the cgroup2 descendant test
  335. * == 1 skb succeeded the cgroup2 descendant test
  336. * < 0 error
  337. *
  338. * u32 bpf_get_hash_recalc(skb)
  339. * Retrieve and possibly recalculate skb->hash.
  340. * @skb: pointer to skb
  341. * Return: hash
  342. *
  343. * u64 bpf_get_current_task(void)
  344. * Returns current task_struct
  345. * Return: current
  346. *
  347. * int bpf_probe_write_user(void *dst, void *src, int len)
  348. * safely attempt to write to a location
  349. * @dst: destination address in userspace
  350. * @src: source address on stack
  351. * @len: number of bytes to copy
  352. * Return: 0 on success or negative error
  353. *
  354. * int bpf_current_task_under_cgroup(map, index)
  355. * Check cgroup2 membership of current task
  356. * @map: pointer to bpf_map in BPF_MAP_TYPE_CGROUP_ARRAY type
  357. * @index: index of the cgroup in the bpf_map
  358. * Return:
  359. * == 0 current failed the cgroup2 descendant test
  360. * == 1 current succeeded the cgroup2 descendant test
  361. * < 0 error
  362. *
  363. * int bpf_skb_change_tail(skb, len, flags)
  364. * The helper will resize the skb to the given new size, to be used f.e.
  365. * with control messages.
  366. * @skb: pointer to skb
  367. * @len: new skb length
  368. * @flags: reserved
  369. * Return: 0 on success or negative error
  370. *
  371. * int bpf_skb_pull_data(skb, len)
  372. * The helper will pull in non-linear data in case the skb is non-linear
  373. * and not all of len are part of the linear section. Only needed for
  374. * read/write with direct packet access.
  375. * @skb: pointer to skb
  376. * @len: len to make read/writeable
  377. * Return: 0 on success or negative error
  378. *
  379. * s64 bpf_csum_update(skb, csum)
  380. * Adds csum into skb->csum in case of CHECKSUM_COMPLETE.
  381. * @skb: pointer to skb
  382. * @csum: csum to add
  383. * Return: csum on success or negative error
  384. *
  385. * void bpf_set_hash_invalid(skb)
  386. * Invalidate current skb->hash.
  387. * @skb: pointer to skb
  388. *
  389. * int bpf_get_numa_node_id()
  390. * Return: Id of current NUMA node.
  391. *
  392. * int bpf_skb_change_head()
  393. * Grows headroom of skb and adjusts MAC header offset accordingly.
  394. * Will extends/reallocae as required automatically.
  395. * May change skb data pointer and will thus invalidate any check
  396. * performed for direct packet access.
  397. * @skb: pointer to skb
  398. * @len: length of header to be pushed in front
  399. * @flags: Flags (unused for now)
  400. * Return: 0 on success or negative error
  401. */
  402. #define __BPF_FUNC_MAPPER(FN) \
  403. FN(unspec), \
  404. FN(map_lookup_elem), \
  405. FN(map_update_elem), \
  406. FN(map_delete_elem), \
  407. FN(probe_read), \
  408. FN(ktime_get_ns), \
  409. FN(trace_printk), \
  410. FN(get_prandom_u32), \
  411. FN(get_smp_processor_id), \
  412. FN(skb_store_bytes), \
  413. FN(l3_csum_replace), \
  414. FN(l4_csum_replace), \
  415. FN(tail_call), \
  416. FN(clone_redirect), \
  417. FN(get_current_pid_tgid), \
  418. FN(get_current_uid_gid), \
  419. FN(get_current_comm), \
  420. FN(get_cgroup_classid), \
  421. FN(skb_vlan_push), \
  422. FN(skb_vlan_pop), \
  423. FN(skb_get_tunnel_key), \
  424. FN(skb_set_tunnel_key), \
  425. FN(perf_event_read), \
  426. FN(redirect), \
  427. FN(get_route_realm), \
  428. FN(perf_event_output), \
  429. FN(skb_load_bytes), \
  430. FN(get_stackid), \
  431. FN(csum_diff), \
  432. FN(skb_get_tunnel_opt), \
  433. FN(skb_set_tunnel_opt), \
  434. FN(skb_change_proto), \
  435. FN(skb_change_type), \
  436. FN(skb_under_cgroup), \
  437. FN(get_hash_recalc), \
  438. FN(get_current_task), \
  439. FN(probe_write_user), \
  440. FN(current_task_under_cgroup), \
  441. FN(skb_change_tail), \
  442. FN(skb_pull_data), \
  443. FN(csum_update), \
  444. FN(set_hash_invalid), \
  445. FN(get_numa_node_id), \
  446. FN(skb_change_head),
  447. /* integer value in 'imm' field of BPF_CALL instruction selects which helper
  448. * function eBPF program intends to call
  449. */
  450. #define __BPF_ENUM_FN(x) BPF_FUNC_ ## x
  451. enum bpf_func_id {
  452. __BPF_FUNC_MAPPER(__BPF_ENUM_FN)
  453. __BPF_FUNC_MAX_ID,
  454. };
  455. #undef __BPF_ENUM_FN
  456. /* All flags used by eBPF helper functions, placed here. */
  457. /* BPF_FUNC_skb_store_bytes flags. */
  458. #define BPF_F_RECOMPUTE_CSUM (1ULL << 0)
  459. #define BPF_F_INVALIDATE_HASH (1ULL << 1)
  460. /* BPF_FUNC_l3_csum_replace and BPF_FUNC_l4_csum_replace flags.
  461. * First 4 bits are for passing the header field size.
  462. */
  463. #define BPF_F_HDR_FIELD_MASK 0xfULL
  464. /* BPF_FUNC_l4_csum_replace flags. */
  465. #define BPF_F_PSEUDO_HDR (1ULL << 4)
  466. #define BPF_F_MARK_MANGLED_0 (1ULL << 5)
  467. /* BPF_FUNC_clone_redirect and BPF_FUNC_redirect flags. */
  468. #define BPF_F_INGRESS (1ULL << 0)
  469. /* BPF_FUNC_skb_set_tunnel_key and BPF_FUNC_skb_get_tunnel_key flags. */
  470. #define BPF_F_TUNINFO_IPV6 (1ULL << 0)
  471. /* BPF_FUNC_get_stackid flags. */
  472. #define BPF_F_SKIP_FIELD_MASK 0xffULL
  473. #define BPF_F_USER_STACK (1ULL << 8)
  474. #define BPF_F_FAST_STACK_CMP (1ULL << 9)
  475. #define BPF_F_REUSE_STACKID (1ULL << 10)
  476. /* BPF_FUNC_skb_set_tunnel_key flags. */
  477. #define BPF_F_ZERO_CSUM_TX (1ULL << 1)
  478. #define BPF_F_DONT_FRAGMENT (1ULL << 2)
  479. /* BPF_FUNC_perf_event_output and BPF_FUNC_perf_event_read flags. */
  480. #define BPF_F_INDEX_MASK 0xffffffffULL
  481. #define BPF_F_CURRENT_CPU BPF_F_INDEX_MASK
  482. /* BPF_FUNC_perf_event_output for sk_buff input context. */
  483. #define BPF_F_CTXLEN_MASK (0xfffffULL << 32)
  484. /* user accessible mirror of in-kernel sk_buff.
  485. * new fields can only be added to the end of this structure
  486. */
  487. struct __sk_buff {
  488. __u32 len;
  489. __u32 pkt_type;
  490. __u32 mark;
  491. __u32 queue_mapping;
  492. __u32 protocol;
  493. __u32 vlan_present;
  494. __u32 vlan_tci;
  495. __u32 vlan_proto;
  496. __u32 priority;
  497. __u32 ingress_ifindex;
  498. __u32 ifindex;
  499. __u32 tc_index;
  500. __u32 cb[5];
  501. __u32 hash;
  502. __u32 tc_classid;
  503. __u32 data;
  504. __u32 data_end;
  505. };
  506. struct bpf_tunnel_key {
  507. __u32 tunnel_id;
  508. union {
  509. __u32 remote_ipv4;
  510. __u32 remote_ipv6[4];
  511. };
  512. __u8 tunnel_tos;
  513. __u8 tunnel_ttl;
  514. __u16 tunnel_ext;
  515. __u32 tunnel_label;
  516. };
  517. /* Generic BPF return codes which all BPF program types may support.
  518. * The values are binary compatible with their TC_ACT_* counter-part to
  519. * provide backwards compatibility with existing SCHED_CLS and SCHED_ACT
  520. * programs.
  521. *
  522. * XDP is handled seprately, see XDP_*.
  523. */
  524. enum bpf_ret_code {
  525. BPF_OK = 0,
  526. /* 1 reserved */
  527. BPF_DROP = 2,
  528. /* 3-6 reserved */
  529. BPF_REDIRECT = 7,
  530. /* >127 are reserved for prog type specific return codes */
  531. };
  532. /* User return codes for XDP prog type.
  533. * A valid XDP program must return one of these defined values. All other
  534. * return codes are reserved for future use. Unknown return codes will result
  535. * in packet drop.
  536. */
  537. enum xdp_action {
  538. XDP_ABORTED = 0,
  539. XDP_DROP,
  540. XDP_PASS,
  541. XDP_TX,
  542. };
  543. /* user accessible metadata for XDP packet hook
  544. * new fields must be added to the end of this structure
  545. */
  546. struct xdp_md {
  547. __u32 data;
  548. __u32 data_end;
  549. };
  550. #endif /* _UAPI__LINUX_BPF_H__ */