Commit | Line | Data |
---|---|---|
f5bffecd AS |
1 | /* |
2 | * Linux Socket Filter - Kernel level socket filtering | |
3 | * | |
4 | * Based on the design of the Berkeley Packet Filter. The new | |
5 | * internal format has been designed by PLUMgrid: | |
6 | * | |
7 | * Copyright (c) 2011 - 2014 PLUMgrid, http://plumgrid.com | |
8 | * | |
9 | * Authors: | |
10 | * | |
11 | * Jay Schulist <jschlst@samba.org> | |
12 | * Alexei Starovoitov <ast@plumgrid.com> | |
13 | * Daniel Borkmann <dborkman@redhat.com> | |
14 | * | |
15 | * This program is free software; you can redistribute it and/or | |
16 | * modify it under the terms of the GNU General Public License | |
17 | * as published by the Free Software Foundation; either version | |
18 | * 2 of the License, or (at your option) any later version. | |
19 | * | |
20 | * Andi Kleen - Fix a few bad bugs and races. | |
4df95ff4 | 21 | * Kris Katterjohn - Added many additional checks in bpf_check_classic() |
f5bffecd | 22 | */ |
738cbe72 | 23 | |
f5bffecd AS |
24 | #include <linux/filter.h> |
25 | #include <linux/skbuff.h> | |
60a3b225 | 26 | #include <linux/vmalloc.h> |
738cbe72 DB |
27 | #include <linux/random.h> |
28 | #include <linux/moduleloader.h> | |
f5bffecd | 29 | #include <asm/unaligned.h> |
09756af4 | 30 | #include <linux/bpf.h> |
f5bffecd AS |
31 | |
32 | /* Registers */ | |
33 | #define BPF_R0 regs[BPF_REG_0] | |
34 | #define BPF_R1 regs[BPF_REG_1] | |
35 | #define BPF_R2 regs[BPF_REG_2] | |
36 | #define BPF_R3 regs[BPF_REG_3] | |
37 | #define BPF_R4 regs[BPF_REG_4] | |
38 | #define BPF_R5 regs[BPF_REG_5] | |
39 | #define BPF_R6 regs[BPF_REG_6] | |
40 | #define BPF_R7 regs[BPF_REG_7] | |
41 | #define BPF_R8 regs[BPF_REG_8] | |
42 | #define BPF_R9 regs[BPF_REG_9] | |
43 | #define BPF_R10 regs[BPF_REG_10] | |
44 | ||
45 | /* Named registers */ | |
46 | #define DST regs[insn->dst_reg] | |
47 | #define SRC regs[insn->src_reg] | |
48 | #define FP regs[BPF_REG_FP] | |
49 | #define ARG1 regs[BPF_REG_ARG1] | |
50 | #define CTX regs[BPF_REG_CTX] | |
51 | #define IMM insn->imm | |
52 | ||
53 | /* No hurry in this branch | |
54 | * | |
55 | * Exported for the bpf jit load helper. | |
56 | */ | |
57 | void *bpf_internal_load_pointer_neg_helper(const struct sk_buff *skb, int k, unsigned int size) | |
58 | { | |
59 | u8 *ptr = NULL; | |
60 | ||
61 | if (k >= SKF_NET_OFF) | |
62 | ptr = skb_network_header(skb) + k - SKF_NET_OFF; | |
63 | else if (k >= SKF_LL_OFF) | |
64 | ptr = skb_mac_header(skb) + k - SKF_LL_OFF; | |
65 | if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb)) | |
66 | return ptr; | |
67 | ||
68 | return NULL; | |
69 | } | |
70 | ||
60a3b225 DB |
71 | struct bpf_prog *bpf_prog_alloc(unsigned int size, gfp_t gfp_extra_flags) |
72 | { | |
73 | gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO | | |
74 | gfp_extra_flags; | |
09756af4 | 75 | struct bpf_prog_aux *aux; |
60a3b225 DB |
76 | struct bpf_prog *fp; |
77 | ||
78 | size = round_up(size, PAGE_SIZE); | |
79 | fp = __vmalloc(size, gfp_flags, PAGE_KERNEL); | |
80 | if (fp == NULL) | |
81 | return NULL; | |
82 | ||
09756af4 AS |
83 | aux = kzalloc(sizeof(*aux), GFP_KERNEL | gfp_extra_flags); |
84 | if (aux == NULL) { | |
60a3b225 DB |
85 | vfree(fp); |
86 | return NULL; | |
87 | } | |
88 | ||
89 | fp->pages = size / PAGE_SIZE; | |
09756af4 | 90 | fp->aux = aux; |
60a3b225 DB |
91 | |
92 | return fp; | |
93 | } | |
94 | EXPORT_SYMBOL_GPL(bpf_prog_alloc); | |
95 | ||
96 | struct bpf_prog *bpf_prog_realloc(struct bpf_prog *fp_old, unsigned int size, | |
97 | gfp_t gfp_extra_flags) | |
98 | { | |
99 | gfp_t gfp_flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO | | |
100 | gfp_extra_flags; | |
101 | struct bpf_prog *fp; | |
102 | ||
103 | BUG_ON(fp_old == NULL); | |
104 | ||
105 | size = round_up(size, PAGE_SIZE); | |
106 | if (size <= fp_old->pages * PAGE_SIZE) | |
107 | return fp_old; | |
108 | ||
109 | fp = __vmalloc(size, gfp_flags, PAGE_KERNEL); | |
110 | if (fp != NULL) { | |
111 | memcpy(fp, fp_old, fp_old->pages * PAGE_SIZE); | |
112 | fp->pages = size / PAGE_SIZE; | |
113 | ||
09756af4 | 114 | /* We keep fp->aux from fp_old around in the new |
60a3b225 DB |
115 | * reallocated structure. |
116 | */ | |
09756af4 | 117 | fp_old->aux = NULL; |
60a3b225 DB |
118 | __bpf_prog_free(fp_old); |
119 | } | |
120 | ||
121 | return fp; | |
122 | } | |
123 | EXPORT_SYMBOL_GPL(bpf_prog_realloc); | |
124 | ||
125 | void __bpf_prog_free(struct bpf_prog *fp) | |
126 | { | |
09756af4 | 127 | kfree(fp->aux); |
60a3b225 DB |
128 | vfree(fp); |
129 | } | |
130 | EXPORT_SYMBOL_GPL(__bpf_prog_free); | |
131 | ||
b954d834 | 132 | #ifdef CONFIG_BPF_JIT |
738cbe72 DB |
133 | struct bpf_binary_header * |
134 | bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr, | |
135 | unsigned int alignment, | |
136 | bpf_jit_fill_hole_t bpf_fill_ill_insns) | |
137 | { | |
138 | struct bpf_binary_header *hdr; | |
139 | unsigned int size, hole, start; | |
140 | ||
141 | /* Most of BPF filters are really small, but if some of them | |
142 | * fill a page, allow at least 128 extra bytes to insert a | |
143 | * random section of illegal instructions. | |
144 | */ | |
145 | size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE); | |
146 | hdr = module_alloc(size); | |
147 | if (hdr == NULL) | |
148 | return NULL; | |
149 | ||
150 | /* Fill space with illegal/arch-dep instructions. */ | |
151 | bpf_fill_ill_insns(hdr, size); | |
152 | ||
153 | hdr->pages = size / PAGE_SIZE; | |
154 | hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)), | |
155 | PAGE_SIZE - sizeof(*hdr)); | |
156 | start = (prandom_u32() % hole) & ~(alignment - 1); | |
157 | ||
158 | /* Leave a random number of instructions before BPF code. */ | |
159 | *image_ptr = &hdr->image[start]; | |
160 | ||
161 | return hdr; | |
162 | } | |
163 | ||
164 | void bpf_jit_binary_free(struct bpf_binary_header *hdr) | |
165 | { | |
be1f221c | 166 | module_memfree(hdr); |
738cbe72 | 167 | } |
b954d834 | 168 | #endif /* CONFIG_BPF_JIT */ |
738cbe72 | 169 | |
f5bffecd AS |
170 | /* Base function for offset calculation. Needs to go into .text section, |
171 | * therefore keeping it non-static as well; will also be used by JITs | |
172 | * anyway later on, so do not let the compiler omit it. | |
173 | */ | |
174 | noinline u64 __bpf_call_base(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) | |
175 | { | |
176 | return 0; | |
177 | } | |
178 | ||
179 | /** | |
7ae457c1 AS |
180 | * __bpf_prog_run - run eBPF program on a given context |
181 | * @ctx: is the data we are operating on | |
182 | * @insn: is the array of eBPF instructions | |
f5bffecd | 183 | * |
7ae457c1 | 184 | * Decode and execute eBPF instructions. |
f5bffecd | 185 | */ |
7ae457c1 | 186 | static unsigned int __bpf_prog_run(void *ctx, const struct bpf_insn *insn) |
f5bffecd AS |
187 | { |
188 | u64 stack[MAX_BPF_STACK / sizeof(u64)]; | |
189 | u64 regs[MAX_BPF_REG], tmp; | |
190 | static const void *jumptable[256] = { | |
191 | [0 ... 255] = &&default_label, | |
192 | /* Now overwrite non-defaults ... */ | |
193 | /* 32 bit ALU operations */ | |
194 | [BPF_ALU | BPF_ADD | BPF_X] = &&ALU_ADD_X, | |
195 | [BPF_ALU | BPF_ADD | BPF_K] = &&ALU_ADD_K, | |
196 | [BPF_ALU | BPF_SUB | BPF_X] = &&ALU_SUB_X, | |
197 | [BPF_ALU | BPF_SUB | BPF_K] = &&ALU_SUB_K, | |
198 | [BPF_ALU | BPF_AND | BPF_X] = &&ALU_AND_X, | |
199 | [BPF_ALU | BPF_AND | BPF_K] = &&ALU_AND_K, | |
200 | [BPF_ALU | BPF_OR | BPF_X] = &&ALU_OR_X, | |
201 | [BPF_ALU | BPF_OR | BPF_K] = &&ALU_OR_K, | |
202 | [BPF_ALU | BPF_LSH | BPF_X] = &&ALU_LSH_X, | |
203 | [BPF_ALU | BPF_LSH | BPF_K] = &&ALU_LSH_K, | |
204 | [BPF_ALU | BPF_RSH | BPF_X] = &&ALU_RSH_X, | |
205 | [BPF_ALU | BPF_RSH | BPF_K] = &&ALU_RSH_K, | |
206 | [BPF_ALU | BPF_XOR | BPF_X] = &&ALU_XOR_X, | |
207 | [BPF_ALU | BPF_XOR | BPF_K] = &&ALU_XOR_K, | |
208 | [BPF_ALU | BPF_MUL | BPF_X] = &&ALU_MUL_X, | |
209 | [BPF_ALU | BPF_MUL | BPF_K] = &&ALU_MUL_K, | |
210 | [BPF_ALU | BPF_MOV | BPF_X] = &&ALU_MOV_X, | |
211 | [BPF_ALU | BPF_MOV | BPF_K] = &&ALU_MOV_K, | |
212 | [BPF_ALU | BPF_DIV | BPF_X] = &&ALU_DIV_X, | |
213 | [BPF_ALU | BPF_DIV | BPF_K] = &&ALU_DIV_K, | |
214 | [BPF_ALU | BPF_MOD | BPF_X] = &&ALU_MOD_X, | |
215 | [BPF_ALU | BPF_MOD | BPF_K] = &&ALU_MOD_K, | |
216 | [BPF_ALU | BPF_NEG] = &&ALU_NEG, | |
217 | [BPF_ALU | BPF_END | BPF_TO_BE] = &&ALU_END_TO_BE, | |
218 | [BPF_ALU | BPF_END | BPF_TO_LE] = &&ALU_END_TO_LE, | |
219 | /* 64 bit ALU operations */ | |
220 | [BPF_ALU64 | BPF_ADD | BPF_X] = &&ALU64_ADD_X, | |
221 | [BPF_ALU64 | BPF_ADD | BPF_K] = &&ALU64_ADD_K, | |
222 | [BPF_ALU64 | BPF_SUB | BPF_X] = &&ALU64_SUB_X, | |
223 | [BPF_ALU64 | BPF_SUB | BPF_K] = &&ALU64_SUB_K, | |
224 | [BPF_ALU64 | BPF_AND | BPF_X] = &&ALU64_AND_X, | |
225 | [BPF_ALU64 | BPF_AND | BPF_K] = &&ALU64_AND_K, | |
226 | [BPF_ALU64 | BPF_OR | BPF_X] = &&ALU64_OR_X, | |
227 | [BPF_ALU64 | BPF_OR | BPF_K] = &&ALU64_OR_K, | |
228 | [BPF_ALU64 | BPF_LSH | BPF_X] = &&ALU64_LSH_X, | |
229 | [BPF_ALU64 | BPF_LSH | BPF_K] = &&ALU64_LSH_K, | |
230 | [BPF_ALU64 | BPF_RSH | BPF_X] = &&ALU64_RSH_X, | |
231 | [BPF_ALU64 | BPF_RSH | BPF_K] = &&ALU64_RSH_K, | |
232 | [BPF_ALU64 | BPF_XOR | BPF_X] = &&ALU64_XOR_X, | |
233 | [BPF_ALU64 | BPF_XOR | BPF_K] = &&ALU64_XOR_K, | |
234 | [BPF_ALU64 | BPF_MUL | BPF_X] = &&ALU64_MUL_X, | |
235 | [BPF_ALU64 | BPF_MUL | BPF_K] = &&ALU64_MUL_K, | |
236 | [BPF_ALU64 | BPF_MOV | BPF_X] = &&ALU64_MOV_X, | |
237 | [BPF_ALU64 | BPF_MOV | BPF_K] = &&ALU64_MOV_K, | |
238 | [BPF_ALU64 | BPF_ARSH | BPF_X] = &&ALU64_ARSH_X, | |
239 | [BPF_ALU64 | BPF_ARSH | BPF_K] = &&ALU64_ARSH_K, | |
240 | [BPF_ALU64 | BPF_DIV | BPF_X] = &&ALU64_DIV_X, | |
241 | [BPF_ALU64 | BPF_DIV | BPF_K] = &&ALU64_DIV_K, | |
242 | [BPF_ALU64 | BPF_MOD | BPF_X] = &&ALU64_MOD_X, | |
243 | [BPF_ALU64 | BPF_MOD | BPF_K] = &&ALU64_MOD_K, | |
244 | [BPF_ALU64 | BPF_NEG] = &&ALU64_NEG, | |
245 | /* Call instruction */ | |
246 | [BPF_JMP | BPF_CALL] = &&JMP_CALL, | |
247 | /* Jumps */ | |
248 | [BPF_JMP | BPF_JA] = &&JMP_JA, | |
249 | [BPF_JMP | BPF_JEQ | BPF_X] = &&JMP_JEQ_X, | |
250 | [BPF_JMP | BPF_JEQ | BPF_K] = &&JMP_JEQ_K, | |
251 | [BPF_JMP | BPF_JNE | BPF_X] = &&JMP_JNE_X, | |
252 | [BPF_JMP | BPF_JNE | BPF_K] = &&JMP_JNE_K, | |
253 | [BPF_JMP | BPF_JGT | BPF_X] = &&JMP_JGT_X, | |
254 | [BPF_JMP | BPF_JGT | BPF_K] = &&JMP_JGT_K, | |
255 | [BPF_JMP | BPF_JGE | BPF_X] = &&JMP_JGE_X, | |
256 | [BPF_JMP | BPF_JGE | BPF_K] = &&JMP_JGE_K, | |
257 | [BPF_JMP | BPF_JSGT | BPF_X] = &&JMP_JSGT_X, | |
258 | [BPF_JMP | BPF_JSGT | BPF_K] = &&JMP_JSGT_K, | |
259 | [BPF_JMP | BPF_JSGE | BPF_X] = &&JMP_JSGE_X, | |
260 | [BPF_JMP | BPF_JSGE | BPF_K] = &&JMP_JSGE_K, | |
261 | [BPF_JMP | BPF_JSET | BPF_X] = &&JMP_JSET_X, | |
262 | [BPF_JMP | BPF_JSET | BPF_K] = &&JMP_JSET_K, | |
263 | /* Program return */ | |
264 | [BPF_JMP | BPF_EXIT] = &&JMP_EXIT, | |
265 | /* Store instructions */ | |
266 | [BPF_STX | BPF_MEM | BPF_B] = &&STX_MEM_B, | |
267 | [BPF_STX | BPF_MEM | BPF_H] = &&STX_MEM_H, | |
268 | [BPF_STX | BPF_MEM | BPF_W] = &&STX_MEM_W, | |
269 | [BPF_STX | BPF_MEM | BPF_DW] = &&STX_MEM_DW, | |
270 | [BPF_STX | BPF_XADD | BPF_W] = &&STX_XADD_W, | |
271 | [BPF_STX | BPF_XADD | BPF_DW] = &&STX_XADD_DW, | |
272 | [BPF_ST | BPF_MEM | BPF_B] = &&ST_MEM_B, | |
273 | [BPF_ST | BPF_MEM | BPF_H] = &&ST_MEM_H, | |
274 | [BPF_ST | BPF_MEM | BPF_W] = &&ST_MEM_W, | |
275 | [BPF_ST | BPF_MEM | BPF_DW] = &&ST_MEM_DW, | |
276 | /* Load instructions */ | |
277 | [BPF_LDX | BPF_MEM | BPF_B] = &&LDX_MEM_B, | |
278 | [BPF_LDX | BPF_MEM | BPF_H] = &&LDX_MEM_H, | |
279 | [BPF_LDX | BPF_MEM | BPF_W] = &&LDX_MEM_W, | |
280 | [BPF_LDX | BPF_MEM | BPF_DW] = &&LDX_MEM_DW, | |
281 | [BPF_LD | BPF_ABS | BPF_W] = &&LD_ABS_W, | |
282 | [BPF_LD | BPF_ABS | BPF_H] = &&LD_ABS_H, | |
283 | [BPF_LD | BPF_ABS | BPF_B] = &&LD_ABS_B, | |
284 | [BPF_LD | BPF_IND | BPF_W] = &&LD_IND_W, | |
285 | [BPF_LD | BPF_IND | BPF_H] = &&LD_IND_H, | |
286 | [BPF_LD | BPF_IND | BPF_B] = &&LD_IND_B, | |
02ab695b | 287 | [BPF_LD | BPF_IMM | BPF_DW] = &&LD_IMM_DW, |
f5bffecd AS |
288 | }; |
289 | void *ptr; | |
290 | int off; | |
291 | ||
292 | #define CONT ({ insn++; goto select_insn; }) | |
293 | #define CONT_JMP ({ insn++; goto select_insn; }) | |
294 | ||
295 | FP = (u64) (unsigned long) &stack[ARRAY_SIZE(stack)]; | |
296 | ARG1 = (u64) (unsigned long) ctx; | |
297 | ||
298 | /* Registers used in classic BPF programs need to be reset first. */ | |
299 | regs[BPF_REG_A] = 0; | |
300 | regs[BPF_REG_X] = 0; | |
301 | ||
302 | select_insn: | |
303 | goto *jumptable[insn->code]; | |
304 | ||
305 | /* ALU */ | |
306 | #define ALU(OPCODE, OP) \ | |
307 | ALU64_##OPCODE##_X: \ | |
308 | DST = DST OP SRC; \ | |
309 | CONT; \ | |
310 | ALU_##OPCODE##_X: \ | |
311 | DST = (u32) DST OP (u32) SRC; \ | |
312 | CONT; \ | |
313 | ALU64_##OPCODE##_K: \ | |
314 | DST = DST OP IMM; \ | |
315 | CONT; \ | |
316 | ALU_##OPCODE##_K: \ | |
317 | DST = (u32) DST OP (u32) IMM; \ | |
318 | CONT; | |
319 | ||
320 | ALU(ADD, +) | |
321 | ALU(SUB, -) | |
322 | ALU(AND, &) | |
323 | ALU(OR, |) | |
324 | ALU(LSH, <<) | |
325 | ALU(RSH, >>) | |
326 | ALU(XOR, ^) | |
327 | ALU(MUL, *) | |
328 | #undef ALU | |
329 | ALU_NEG: | |
330 | DST = (u32) -DST; | |
331 | CONT; | |
332 | ALU64_NEG: | |
333 | DST = -DST; | |
334 | CONT; | |
335 | ALU_MOV_X: | |
336 | DST = (u32) SRC; | |
337 | CONT; | |
338 | ALU_MOV_K: | |
339 | DST = (u32) IMM; | |
340 | CONT; | |
341 | ALU64_MOV_X: | |
342 | DST = SRC; | |
343 | CONT; | |
344 | ALU64_MOV_K: | |
345 | DST = IMM; | |
346 | CONT; | |
02ab695b AS |
347 | LD_IMM_DW: |
348 | DST = (u64) (u32) insn[0].imm | ((u64) (u32) insn[1].imm) << 32; | |
349 | insn++; | |
350 | CONT; | |
f5bffecd AS |
351 | ALU64_ARSH_X: |
352 | (*(s64 *) &DST) >>= SRC; | |
353 | CONT; | |
354 | ALU64_ARSH_K: | |
355 | (*(s64 *) &DST) >>= IMM; | |
356 | CONT; | |
357 | ALU64_MOD_X: | |
358 | if (unlikely(SRC == 0)) | |
359 | return 0; | |
360 | tmp = DST; | |
361 | DST = do_div(tmp, SRC); | |
362 | CONT; | |
363 | ALU_MOD_X: | |
364 | if (unlikely(SRC == 0)) | |
365 | return 0; | |
366 | tmp = (u32) DST; | |
367 | DST = do_div(tmp, (u32) SRC); | |
368 | CONT; | |
369 | ALU64_MOD_K: | |
370 | tmp = DST; | |
371 | DST = do_div(tmp, IMM); | |
372 | CONT; | |
373 | ALU_MOD_K: | |
374 | tmp = (u32) DST; | |
375 | DST = do_div(tmp, (u32) IMM); | |
376 | CONT; | |
377 | ALU64_DIV_X: | |
378 | if (unlikely(SRC == 0)) | |
379 | return 0; | |
380 | do_div(DST, SRC); | |
381 | CONT; | |
382 | ALU_DIV_X: | |
383 | if (unlikely(SRC == 0)) | |
384 | return 0; | |
385 | tmp = (u32) DST; | |
386 | do_div(tmp, (u32) SRC); | |
387 | DST = (u32) tmp; | |
388 | CONT; | |
389 | ALU64_DIV_K: | |
390 | do_div(DST, IMM); | |
391 | CONT; | |
392 | ALU_DIV_K: | |
393 | tmp = (u32) DST; | |
394 | do_div(tmp, (u32) IMM); | |
395 | DST = (u32) tmp; | |
396 | CONT; | |
397 | ALU_END_TO_BE: | |
398 | switch (IMM) { | |
399 | case 16: | |
400 | DST = (__force u16) cpu_to_be16(DST); | |
401 | break; | |
402 | case 32: | |
403 | DST = (__force u32) cpu_to_be32(DST); | |
404 | break; | |
405 | case 64: | |
406 | DST = (__force u64) cpu_to_be64(DST); | |
407 | break; | |
408 | } | |
409 | CONT; | |
410 | ALU_END_TO_LE: | |
411 | switch (IMM) { | |
412 | case 16: | |
413 | DST = (__force u16) cpu_to_le16(DST); | |
414 | break; | |
415 | case 32: | |
416 | DST = (__force u32) cpu_to_le32(DST); | |
417 | break; | |
418 | case 64: | |
419 | DST = (__force u64) cpu_to_le64(DST); | |
420 | break; | |
421 | } | |
422 | CONT; | |
423 | ||
424 | /* CALL */ | |
425 | JMP_CALL: | |
426 | /* Function call scratches BPF_R1-BPF_R5 registers, | |
427 | * preserves BPF_R6-BPF_R9, and stores return value | |
428 | * into BPF_R0. | |
429 | */ | |
430 | BPF_R0 = (__bpf_call_base + insn->imm)(BPF_R1, BPF_R2, BPF_R3, | |
431 | BPF_R4, BPF_R5); | |
432 | CONT; | |
433 | ||
434 | /* JMP */ | |
435 | JMP_JA: | |
436 | insn += insn->off; | |
437 | CONT; | |
438 | JMP_JEQ_X: | |
439 | if (DST == SRC) { | |
440 | insn += insn->off; | |
441 | CONT_JMP; | |
442 | } | |
443 | CONT; | |
444 | JMP_JEQ_K: | |
445 | if (DST == IMM) { | |
446 | insn += insn->off; | |
447 | CONT_JMP; | |
448 | } | |
449 | CONT; | |
450 | JMP_JNE_X: | |
451 | if (DST != SRC) { | |
452 | insn += insn->off; | |
453 | CONT_JMP; | |
454 | } | |
455 | CONT; | |
456 | JMP_JNE_K: | |
457 | if (DST != IMM) { | |
458 | insn += insn->off; | |
459 | CONT_JMP; | |
460 | } | |
461 | CONT; | |
462 | JMP_JGT_X: | |
463 | if (DST > SRC) { | |
464 | insn += insn->off; | |
465 | CONT_JMP; | |
466 | } | |
467 | CONT; | |
468 | JMP_JGT_K: | |
469 | if (DST > IMM) { | |
470 | insn += insn->off; | |
471 | CONT_JMP; | |
472 | } | |
473 | CONT; | |
474 | JMP_JGE_X: | |
475 | if (DST >= SRC) { | |
476 | insn += insn->off; | |
477 | CONT_JMP; | |
478 | } | |
479 | CONT; | |
480 | JMP_JGE_K: | |
481 | if (DST >= IMM) { | |
482 | insn += insn->off; | |
483 | CONT_JMP; | |
484 | } | |
485 | CONT; | |
486 | JMP_JSGT_X: | |
487 | if (((s64) DST) > ((s64) SRC)) { | |
488 | insn += insn->off; | |
489 | CONT_JMP; | |
490 | } | |
491 | CONT; | |
492 | JMP_JSGT_K: | |
493 | if (((s64) DST) > ((s64) IMM)) { | |
494 | insn += insn->off; | |
495 | CONT_JMP; | |
496 | } | |
497 | CONT; | |
498 | JMP_JSGE_X: | |
499 | if (((s64) DST) >= ((s64) SRC)) { | |
500 | insn += insn->off; | |
501 | CONT_JMP; | |
502 | } | |
503 | CONT; | |
504 | JMP_JSGE_K: | |
505 | if (((s64) DST) >= ((s64) IMM)) { | |
506 | insn += insn->off; | |
507 | CONT_JMP; | |
508 | } | |
509 | CONT; | |
510 | JMP_JSET_X: | |
511 | if (DST & SRC) { | |
512 | insn += insn->off; | |
513 | CONT_JMP; | |
514 | } | |
515 | CONT; | |
516 | JMP_JSET_K: | |
517 | if (DST & IMM) { | |
518 | insn += insn->off; | |
519 | CONT_JMP; | |
520 | } | |
521 | CONT; | |
522 | JMP_EXIT: | |
523 | return BPF_R0; | |
524 | ||
525 | /* STX and ST and LDX*/ | |
526 | #define LDST(SIZEOP, SIZE) \ | |
527 | STX_MEM_##SIZEOP: \ | |
528 | *(SIZE *)(unsigned long) (DST + insn->off) = SRC; \ | |
529 | CONT; \ | |
530 | ST_MEM_##SIZEOP: \ | |
531 | *(SIZE *)(unsigned long) (DST + insn->off) = IMM; \ | |
532 | CONT; \ | |
533 | LDX_MEM_##SIZEOP: \ | |
534 | DST = *(SIZE *)(unsigned long) (SRC + insn->off); \ | |
535 | CONT; | |
536 | ||
537 | LDST(B, u8) | |
538 | LDST(H, u16) | |
539 | LDST(W, u32) | |
540 | LDST(DW, u64) | |
541 | #undef LDST | |
542 | STX_XADD_W: /* lock xadd *(u32 *)(dst_reg + off16) += src_reg */ | |
543 | atomic_add((u32) SRC, (atomic_t *)(unsigned long) | |
544 | (DST + insn->off)); | |
545 | CONT; | |
546 | STX_XADD_DW: /* lock xadd *(u64 *)(dst_reg + off16) += src_reg */ | |
547 | atomic64_add((u64) SRC, (atomic64_t *)(unsigned long) | |
548 | (DST + insn->off)); | |
549 | CONT; | |
550 | LD_ABS_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + imm32)) */ | |
551 | off = IMM; | |
552 | load_word: | |
553 | /* BPF_LD + BPD_ABS and BPF_LD + BPF_IND insns are | |
554 | * only appearing in the programs where ctx == | |
555 | * skb. All programs keep 'ctx' in regs[BPF_REG_CTX] | |
8fb575ca | 556 | * == BPF_R6, bpf_convert_filter() saves it in BPF_R6, |
f5bffecd AS |
557 | * internal BPF verifier will check that BPF_R6 == |
558 | * ctx. | |
559 | * | |
560 | * BPF_ABS and BPF_IND are wrappers of function calls, | |
561 | * so they scratch BPF_R1-BPF_R5 registers, preserve | |
562 | * BPF_R6-BPF_R9, and store return value into BPF_R0. | |
563 | * | |
564 | * Implicit input: | |
565 | * ctx == skb == BPF_R6 == CTX | |
566 | * | |
567 | * Explicit input: | |
568 | * SRC == any register | |
569 | * IMM == 32-bit immediate | |
570 | * | |
571 | * Output: | |
572 | * BPF_R0 - 8/16/32-bit skb data converted to cpu endianness | |
573 | */ | |
574 | ||
575 | ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 4, &tmp); | |
576 | if (likely(ptr != NULL)) { | |
577 | BPF_R0 = get_unaligned_be32(ptr); | |
578 | CONT; | |
579 | } | |
580 | ||
581 | return 0; | |
582 | LD_ABS_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + imm32)) */ | |
583 | off = IMM; | |
584 | load_half: | |
585 | ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 2, &tmp); | |
586 | if (likely(ptr != NULL)) { | |
587 | BPF_R0 = get_unaligned_be16(ptr); | |
588 | CONT; | |
589 | } | |
590 | ||
591 | return 0; | |
592 | LD_ABS_B: /* BPF_R0 = *(u8 *) (skb->data + imm32) */ | |
593 | off = IMM; | |
594 | load_byte: | |
595 | ptr = bpf_load_pointer((struct sk_buff *) (unsigned long) CTX, off, 1, &tmp); | |
596 | if (likely(ptr != NULL)) { | |
597 | BPF_R0 = *(u8 *)ptr; | |
598 | CONT; | |
599 | } | |
600 | ||
601 | return 0; | |
602 | LD_IND_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + src_reg + imm32)) */ | |
603 | off = IMM + SRC; | |
604 | goto load_word; | |
605 | LD_IND_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + src_reg + imm32)) */ | |
606 | off = IMM + SRC; | |
607 | goto load_half; | |
608 | LD_IND_B: /* BPF_R0 = *(u8 *) (skb->data + src_reg + imm32) */ | |
609 | off = IMM + SRC; | |
610 | goto load_byte; | |
611 | ||
612 | default_label: | |
613 | /* If we ever reach this, we have a bug somewhere. */ | |
614 | WARN_RATELIMIT(1, "unknown opcode %02x\n", insn->code); | |
615 | return 0; | |
616 | } | |
617 | ||
7ae457c1 | 618 | void __weak bpf_int_jit_compile(struct bpf_prog *prog) |
f5bffecd AS |
619 | { |
620 | } | |
621 | ||
622 | /** | |
7ae457c1 AS |
623 | * bpf_prog_select_runtime - select execution runtime for BPF program |
624 | * @fp: bpf_prog populated with internal BPF program | |
f5bffecd AS |
625 | * |
626 | * try to JIT internal BPF program, if JIT is not available select interpreter | |
7ae457c1 | 627 | * BPF program will be executed via BPF_PROG_RUN() macro |
f5bffecd | 628 | */ |
7ae457c1 | 629 | void bpf_prog_select_runtime(struct bpf_prog *fp) |
f5bffecd | 630 | { |
7ae457c1 | 631 | fp->bpf_func = (void *) __bpf_prog_run; |
f5bffecd AS |
632 | |
633 | /* Probe if internal BPF can be JITed */ | |
634 | bpf_int_jit_compile(fp); | |
60a3b225 DB |
635 | /* Lock whole bpf_prog as read-only */ |
636 | bpf_prog_lock_ro(fp); | |
f5bffecd | 637 | } |
7ae457c1 | 638 | EXPORT_SYMBOL_GPL(bpf_prog_select_runtime); |
f5bffecd | 639 | |
60a3b225 DB |
640 | static void bpf_prog_free_deferred(struct work_struct *work) |
641 | { | |
09756af4 | 642 | struct bpf_prog_aux *aux; |
60a3b225 | 643 | |
09756af4 AS |
644 | aux = container_of(work, struct bpf_prog_aux, work); |
645 | bpf_jit_free(aux->prog); | |
60a3b225 DB |
646 | } |
647 | ||
648 | /* Free internal BPF program */ | |
7ae457c1 | 649 | void bpf_prog_free(struct bpf_prog *fp) |
f5bffecd | 650 | { |
09756af4 | 651 | struct bpf_prog_aux *aux = fp->aux; |
60a3b225 | 652 | |
09756af4 AS |
653 | INIT_WORK(&aux->work, bpf_prog_free_deferred); |
654 | aux->prog = fp; | |
655 | schedule_work(&aux->work); | |
f5bffecd | 656 | } |
7ae457c1 | 657 | EXPORT_SYMBOL_GPL(bpf_prog_free); |
f89b7755 | 658 | |
3ba67dab DB |
659 | /* Weak definitions of helper functions in case we don't have bpf syscall. */ |
660 | const struct bpf_func_proto bpf_map_lookup_elem_proto __weak; | |
661 | const struct bpf_func_proto bpf_map_update_elem_proto __weak; | |
662 | const struct bpf_func_proto bpf_map_delete_elem_proto __weak; | |
663 | ||
03e69b50 | 664 | const struct bpf_func_proto bpf_get_prandom_u32_proto __weak; |
c04167ce | 665 | const struct bpf_func_proto bpf_get_smp_processor_id_proto __weak; |
03e69b50 | 666 | |
f89b7755 AS |
667 | /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call |
668 | * skb_copy_bits(), so provide a weak definition of it for NET-less config. | |
669 | */ | |
670 | int __weak skb_copy_bits(const struct sk_buff *skb, int offset, void *to, | |
671 | int len) | |
672 | { | |
673 | return -EFAULT; | |
674 | } |