xref: /dpdk/lib/bpf/bpf_exec.c (revision 09442498ef736d0a96632cf8b8c15d8ca78a6468)
1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2018 Intel Corporation
3  */
4 
5 #include <stdio.h>
6 #include <stdint.h>
7 
8 #include <rte_common.h>
9 #include <rte_log.h>
10 #include <rte_debug.h>
11 #include <rte_byteorder.h>
12 
13 #include "bpf_impl.h"
14 
15 #define BPF_JMP_UNC(ins)	((ins) += (ins)->off)
16 
17 #define BPF_JMP_CND_REG(reg, ins, op, type)	\
18 	((ins) += \
19 		((type)(reg)[(ins)->dst_reg] op (type)(reg)[(ins)->src_reg]) ? \
20 		(ins)->off : 0)
21 
22 #define BPF_JMP_CND_IMM(reg, ins, op, type)	\
23 	((ins) += \
24 		((type)(reg)[(ins)->dst_reg] op (type)(ins)->imm) ? \
25 		(ins)->off : 0)
26 
27 #define BPF_NEG_ALU(reg, ins, type)	\
28 	((reg)[(ins)->dst_reg] = (type)(-(reg)[(ins)->dst_reg]))
29 
30 #define EBPF_MOV_ALU_REG(reg, ins, type)	\
31 	((reg)[(ins)->dst_reg] = (type)(reg)[(ins)->src_reg])
32 
33 #define BPF_OP_ALU_REG(reg, ins, op, type)	\
34 	((reg)[(ins)->dst_reg] = \
35 		(type)(reg)[(ins)->dst_reg] op (type)(reg)[(ins)->src_reg])
36 
37 #define EBPF_MOV_ALU_IMM(reg, ins, type)	\
38 	((reg)[(ins)->dst_reg] = (type)(ins)->imm)
39 
40 #define BPF_OP_ALU_IMM(reg, ins, op, type)	\
41 	((reg)[(ins)->dst_reg] = \
42 		(type)(reg)[(ins)->dst_reg] op (type)(ins)->imm)
43 
44 #define BPF_DIV_ZERO_CHECK(bpf, reg, ins, type) do { \
45 	if ((type)(reg)[(ins)->src_reg] == 0) { \
46 		RTE_BPF_LOG(ERR, \
47 			"%s(%p): division by 0 at pc: %#zx;\n", \
48 			__func__, bpf, \
49 			(uintptr_t)(ins) - (uintptr_t)(bpf)->prm.ins); \
50 		return 0; \
51 	} \
52 } while (0)
53 
54 #define BPF_LD_REG(reg, ins, type)	\
55 	((reg)[(ins)->dst_reg] = \
56 		*(type *)(uintptr_t)((reg)[(ins)->src_reg] + (ins)->off))
57 
58 #define BPF_ST_IMM(reg, ins, type)	\
59 	(*(type *)(uintptr_t)((reg)[(ins)->dst_reg] + (ins)->off) = \
60 		(type)(ins)->imm)
61 
62 #define BPF_ST_REG(reg, ins, type)	\
63 	(*(type *)(uintptr_t)((reg)[(ins)->dst_reg] + (ins)->off) = \
64 		(type)(reg)[(ins)->src_reg])
65 
66 #define BPF_ST_XADD_REG(reg, ins, tp)	\
67 	(rte_atomic##tp##_add((rte_atomic##tp##_t *) \
68 		(uintptr_t)((reg)[(ins)->dst_reg] + (ins)->off), \
69 		reg[ins->src_reg]))
70 
71 /* BPF_LD | BPF_ABS/BPF_IND */
72 
73 #define	NOP(x)	(x)
74 
75 #define BPF_LD_ABS(bpf, reg, ins, type, op) do { \
76 	const type *p = bpf_ld_mbuf(bpf, reg, ins, (ins)->imm, sizeof(type)); \
77 	if (p == NULL)  \
78 		return 0; \
79 	reg[EBPF_REG_0] = op(p[0]); \
80 } while (0)
81 
82 #define BPF_LD_IND(bpf, reg, ins, type, op) do { \
83 	uint32_t ofs = reg[ins->src_reg] + (ins)->imm; \
84 	const type *p = bpf_ld_mbuf(bpf, reg, ins, ofs, sizeof(type)); \
85 	if (p == NULL)  \
86 		return 0; \
87 	reg[EBPF_REG_0] = op(p[0]); \
88 } while (0)
89 
90 
91 static inline void
92 bpf_alu_be(uint64_t reg[EBPF_REG_NUM], const struct ebpf_insn *ins)
93 {
94 	uint64_t *v;
95 
96 	v = reg + ins->dst_reg;
97 	switch (ins->imm) {
98 	case 16:
99 		*v = rte_cpu_to_be_16(*v);
100 		break;
101 	case 32:
102 		*v = rte_cpu_to_be_32(*v);
103 		break;
104 	case 64:
105 		*v = rte_cpu_to_be_64(*v);
106 		break;
107 	}
108 }
109 
110 static inline void
111 bpf_alu_le(uint64_t reg[EBPF_REG_NUM], const struct ebpf_insn *ins)
112 {
113 	uint64_t *v;
114 
115 	v = reg + ins->dst_reg;
116 	switch (ins->imm) {
117 	case 16:
118 		*v = rte_cpu_to_le_16(*v);
119 		break;
120 	case 32:
121 		*v = rte_cpu_to_le_32(*v);
122 		break;
123 	case 64:
124 		*v = rte_cpu_to_le_64(*v);
125 		break;
126 	}
127 }
128 
129 static inline const void *
130 bpf_ld_mbuf(const struct rte_bpf *bpf, uint64_t reg[EBPF_REG_NUM],
131 	const struct ebpf_insn *ins, uint32_t off, uint32_t len)
132 {
133 	const struct rte_mbuf *mb;
134 	const void *p;
135 
136 	mb = (const struct rte_mbuf *)(uintptr_t)reg[EBPF_REG_6];
137 	p = rte_pktmbuf_read(mb, off, len, reg + EBPF_REG_0);
138 	if (p == NULL)
139 		RTE_BPF_LOG(DEBUG, "%s(bpf=%p, mbuf=%p, ofs=%u, len=%u): "
140 			"load beyond packet boundary at pc: %#zx;\n",
141 			__func__, bpf, mb, off, len,
142 			(uintptr_t)(ins) - (uintptr_t)(bpf)->prm.ins);
143 	return p;
144 }
145 
146 static inline uint64_t
147 bpf_exec(const struct rte_bpf *bpf, uint64_t reg[EBPF_REG_NUM])
148 {
149 	const struct ebpf_insn *ins;
150 
151 	for (ins = bpf->prm.ins; ; ins++) {
152 		switch (ins->code) {
153 		/* 32 bit ALU IMM operations */
154 		case (BPF_ALU | BPF_ADD | BPF_K):
155 			BPF_OP_ALU_IMM(reg, ins, +, uint32_t);
156 			break;
157 		case (BPF_ALU | BPF_SUB | BPF_K):
158 			BPF_OP_ALU_IMM(reg, ins, -, uint32_t);
159 			break;
160 		case (BPF_ALU | BPF_AND | BPF_K):
161 			BPF_OP_ALU_IMM(reg, ins, &, uint32_t);
162 			break;
163 		case (BPF_ALU | BPF_OR | BPF_K):
164 			BPF_OP_ALU_IMM(reg, ins, |, uint32_t);
165 			break;
166 		case (BPF_ALU | BPF_LSH | BPF_K):
167 			BPF_OP_ALU_IMM(reg, ins, <<, uint32_t);
168 			break;
169 		case (BPF_ALU | BPF_RSH | BPF_K):
170 			BPF_OP_ALU_IMM(reg, ins, >>, uint32_t);
171 			break;
172 		case (BPF_ALU | BPF_XOR | BPF_K):
173 			BPF_OP_ALU_IMM(reg, ins, ^, uint32_t);
174 			break;
175 		case (BPF_ALU | BPF_MUL | BPF_K):
176 			BPF_OP_ALU_IMM(reg, ins, *, uint32_t);
177 			break;
178 		case (BPF_ALU | BPF_DIV | BPF_K):
179 			BPF_OP_ALU_IMM(reg, ins, /, uint32_t);
180 			break;
181 		case (BPF_ALU | BPF_MOD | BPF_K):
182 			BPF_OP_ALU_IMM(reg, ins, %, uint32_t);
183 			break;
184 		case (BPF_ALU | EBPF_MOV | BPF_K):
185 			EBPF_MOV_ALU_IMM(reg, ins, uint32_t);
186 			break;
187 		/* 32 bit ALU REG operations */
188 		case (BPF_ALU | BPF_ADD | BPF_X):
189 			BPF_OP_ALU_REG(reg, ins, +, uint32_t);
190 			break;
191 		case (BPF_ALU | BPF_SUB | BPF_X):
192 			BPF_OP_ALU_REG(reg, ins, -, uint32_t);
193 			break;
194 		case (BPF_ALU | BPF_AND | BPF_X):
195 			BPF_OP_ALU_REG(reg, ins, &, uint32_t);
196 			break;
197 		case (BPF_ALU | BPF_OR | BPF_X):
198 			BPF_OP_ALU_REG(reg, ins, |, uint32_t);
199 			break;
200 		case (BPF_ALU | BPF_LSH | BPF_X):
201 			BPF_OP_ALU_REG(reg, ins, <<, uint32_t);
202 			break;
203 		case (BPF_ALU | BPF_RSH | BPF_X):
204 			BPF_OP_ALU_REG(reg, ins, >>, uint32_t);
205 			break;
206 		case (BPF_ALU | BPF_XOR | BPF_X):
207 			BPF_OP_ALU_REG(reg, ins, ^, uint32_t);
208 			break;
209 		case (BPF_ALU | BPF_MUL | BPF_X):
210 			BPF_OP_ALU_REG(reg, ins, *, uint32_t);
211 			break;
212 		case (BPF_ALU | BPF_DIV | BPF_X):
213 			BPF_DIV_ZERO_CHECK(bpf, reg, ins, uint32_t);
214 			BPF_OP_ALU_REG(reg, ins, /, uint32_t);
215 			break;
216 		case (BPF_ALU | BPF_MOD | BPF_X):
217 			BPF_DIV_ZERO_CHECK(bpf, reg, ins, uint32_t);
218 			BPF_OP_ALU_REG(reg, ins, %, uint32_t);
219 			break;
220 		case (BPF_ALU | EBPF_MOV | BPF_X):
221 			EBPF_MOV_ALU_REG(reg, ins, uint32_t);
222 			break;
223 		case (BPF_ALU | BPF_NEG):
224 			BPF_NEG_ALU(reg, ins, uint32_t);
225 			break;
226 		case (BPF_ALU | EBPF_END | EBPF_TO_BE):
227 			bpf_alu_be(reg, ins);
228 			break;
229 		case (BPF_ALU | EBPF_END | EBPF_TO_LE):
230 			bpf_alu_le(reg, ins);
231 			break;
232 		/* 64 bit ALU IMM operations */
233 		case (EBPF_ALU64 | BPF_ADD | BPF_K):
234 			BPF_OP_ALU_IMM(reg, ins, +, uint64_t);
235 			break;
236 		case (EBPF_ALU64 | BPF_SUB | BPF_K):
237 			BPF_OP_ALU_IMM(reg, ins, -, uint64_t);
238 			break;
239 		case (EBPF_ALU64 | BPF_AND | BPF_K):
240 			BPF_OP_ALU_IMM(reg, ins, &, uint64_t);
241 			break;
242 		case (EBPF_ALU64 | BPF_OR | BPF_K):
243 			BPF_OP_ALU_IMM(reg, ins, |, uint64_t);
244 			break;
245 		case (EBPF_ALU64 | BPF_LSH | BPF_K):
246 			BPF_OP_ALU_IMM(reg, ins, <<, uint64_t);
247 			break;
248 		case (EBPF_ALU64 | BPF_RSH | BPF_K):
249 			BPF_OP_ALU_IMM(reg, ins, >>, uint64_t);
250 			break;
251 		case (EBPF_ALU64 | EBPF_ARSH | BPF_K):
252 			BPF_OP_ALU_IMM(reg, ins, >>, int64_t);
253 			break;
254 		case (EBPF_ALU64 | BPF_XOR | BPF_K):
255 			BPF_OP_ALU_IMM(reg, ins, ^, uint64_t);
256 			break;
257 		case (EBPF_ALU64 | BPF_MUL | BPF_K):
258 			BPF_OP_ALU_IMM(reg, ins, *, uint64_t);
259 			break;
260 		case (EBPF_ALU64 | BPF_DIV | BPF_K):
261 			BPF_OP_ALU_IMM(reg, ins, /, uint64_t);
262 			break;
263 		case (EBPF_ALU64 | BPF_MOD | BPF_K):
264 			BPF_OP_ALU_IMM(reg, ins, %, uint64_t);
265 			break;
266 		case (EBPF_ALU64 | EBPF_MOV | BPF_K):
267 			EBPF_MOV_ALU_IMM(reg, ins, uint64_t);
268 			break;
269 		/* 64 bit ALU REG operations */
270 		case (EBPF_ALU64 | BPF_ADD | BPF_X):
271 			BPF_OP_ALU_REG(reg, ins, +, uint64_t);
272 			break;
273 		case (EBPF_ALU64 | BPF_SUB | BPF_X):
274 			BPF_OP_ALU_REG(reg, ins, -, uint64_t);
275 			break;
276 		case (EBPF_ALU64 | BPF_AND | BPF_X):
277 			BPF_OP_ALU_REG(reg, ins, &, uint64_t);
278 			break;
279 		case (EBPF_ALU64 | BPF_OR | BPF_X):
280 			BPF_OP_ALU_REG(reg, ins, |, uint64_t);
281 			break;
282 		case (EBPF_ALU64 | BPF_LSH | BPF_X):
283 			BPF_OP_ALU_REG(reg, ins, <<, uint64_t);
284 			break;
285 		case (EBPF_ALU64 | BPF_RSH | BPF_X):
286 			BPF_OP_ALU_REG(reg, ins, >>, uint64_t);
287 			break;
288 		case (EBPF_ALU64 | EBPF_ARSH | BPF_X):
289 			BPF_OP_ALU_REG(reg, ins, >>, int64_t);
290 			break;
291 		case (EBPF_ALU64 | BPF_XOR | BPF_X):
292 			BPF_OP_ALU_REG(reg, ins, ^, uint64_t);
293 			break;
294 		case (EBPF_ALU64 | BPF_MUL | BPF_X):
295 			BPF_OP_ALU_REG(reg, ins, *, uint64_t);
296 			break;
297 		case (EBPF_ALU64 | BPF_DIV | BPF_X):
298 			BPF_DIV_ZERO_CHECK(bpf, reg, ins, uint64_t);
299 			BPF_OP_ALU_REG(reg, ins, /, uint64_t);
300 			break;
301 		case (EBPF_ALU64 | BPF_MOD | BPF_X):
302 			BPF_DIV_ZERO_CHECK(bpf, reg, ins, uint64_t);
303 			BPF_OP_ALU_REG(reg, ins, %, uint64_t);
304 			break;
305 		case (EBPF_ALU64 | EBPF_MOV | BPF_X):
306 			EBPF_MOV_ALU_REG(reg, ins, uint64_t);
307 			break;
308 		case (EBPF_ALU64 | BPF_NEG):
309 			BPF_NEG_ALU(reg, ins, uint64_t);
310 			break;
311 		/* load instructions */
312 		case (BPF_LDX | BPF_MEM | BPF_B):
313 			BPF_LD_REG(reg, ins, uint8_t);
314 			break;
315 		case (BPF_LDX | BPF_MEM | BPF_H):
316 			BPF_LD_REG(reg, ins, uint16_t);
317 			break;
318 		case (BPF_LDX | BPF_MEM | BPF_W):
319 			BPF_LD_REG(reg, ins, uint32_t);
320 			break;
321 		case (BPF_LDX | BPF_MEM | EBPF_DW):
322 			BPF_LD_REG(reg, ins, uint64_t);
323 			break;
324 		/* load 64 bit immediate value */
325 		case (BPF_LD | BPF_IMM | EBPF_DW):
326 			reg[ins->dst_reg] = (uint32_t)ins[0].imm |
327 				(uint64_t)(uint32_t)ins[1].imm << 32;
328 			ins++;
329 			break;
330 		/* load absolute instructions */
331 		case (BPF_LD | BPF_ABS | BPF_B):
332 			BPF_LD_ABS(bpf, reg, ins, uint8_t, NOP);
333 			break;
334 		case (BPF_LD | BPF_ABS | BPF_H):
335 			BPF_LD_ABS(bpf, reg, ins, uint16_t, rte_be_to_cpu_16);
336 			break;
337 		case (BPF_LD | BPF_ABS | BPF_W):
338 			BPF_LD_ABS(bpf, reg, ins, uint32_t, rte_be_to_cpu_32);
339 			break;
340 		/* load indirect instructions */
341 		case (BPF_LD | BPF_IND | BPF_B):
342 			BPF_LD_IND(bpf, reg, ins, uint8_t, NOP);
343 			break;
344 		case (BPF_LD | BPF_IND | BPF_H):
345 			BPF_LD_IND(bpf, reg, ins, uint16_t, rte_be_to_cpu_16);
346 			break;
347 		case (BPF_LD | BPF_IND | BPF_W):
348 			BPF_LD_IND(bpf, reg, ins, uint32_t, rte_be_to_cpu_32);
349 			break;
350 		/* store instructions */
351 		case (BPF_STX | BPF_MEM | BPF_B):
352 			BPF_ST_REG(reg, ins, uint8_t);
353 			break;
354 		case (BPF_STX | BPF_MEM | BPF_H):
355 			BPF_ST_REG(reg, ins, uint16_t);
356 			break;
357 		case (BPF_STX | BPF_MEM | BPF_W):
358 			BPF_ST_REG(reg, ins, uint32_t);
359 			break;
360 		case (BPF_STX | BPF_MEM | EBPF_DW):
361 			BPF_ST_REG(reg, ins, uint64_t);
362 			break;
363 		case (BPF_ST | BPF_MEM | BPF_B):
364 			BPF_ST_IMM(reg, ins, uint8_t);
365 			break;
366 		case (BPF_ST | BPF_MEM | BPF_H):
367 			BPF_ST_IMM(reg, ins, uint16_t);
368 			break;
369 		case (BPF_ST | BPF_MEM | BPF_W):
370 			BPF_ST_IMM(reg, ins, uint32_t);
371 			break;
372 		case (BPF_ST | BPF_MEM | EBPF_DW):
373 			BPF_ST_IMM(reg, ins, uint64_t);
374 			break;
375 		/* atomic add instructions */
376 		case (BPF_STX | EBPF_XADD | BPF_W):
377 			BPF_ST_XADD_REG(reg, ins, 32);
378 			break;
379 		case (BPF_STX | EBPF_XADD | EBPF_DW):
380 			BPF_ST_XADD_REG(reg, ins, 64);
381 			break;
382 		/* jump instructions */
383 		case (BPF_JMP | BPF_JA):
384 			BPF_JMP_UNC(ins);
385 			break;
386 		/* jump IMM instructions */
387 		case (BPF_JMP | BPF_JEQ | BPF_K):
388 			BPF_JMP_CND_IMM(reg, ins, ==, uint64_t);
389 			break;
390 		case (BPF_JMP | EBPF_JNE | BPF_K):
391 			BPF_JMP_CND_IMM(reg, ins, !=, uint64_t);
392 			break;
393 		case (BPF_JMP | BPF_JGT | BPF_K):
394 			BPF_JMP_CND_IMM(reg, ins, >, uint64_t);
395 			break;
396 		case (BPF_JMP | EBPF_JLT | BPF_K):
397 			BPF_JMP_CND_IMM(reg, ins, <, uint64_t);
398 			break;
399 		case (BPF_JMP | BPF_JGE | BPF_K):
400 			BPF_JMP_CND_IMM(reg, ins, >=, uint64_t);
401 			break;
402 		case (BPF_JMP | EBPF_JLE | BPF_K):
403 			BPF_JMP_CND_IMM(reg, ins, <=, uint64_t);
404 			break;
405 		case (BPF_JMP | EBPF_JSGT | BPF_K):
406 			BPF_JMP_CND_IMM(reg, ins, >, int64_t);
407 			break;
408 		case (BPF_JMP | EBPF_JSLT | BPF_K):
409 			BPF_JMP_CND_IMM(reg, ins, <, int64_t);
410 			break;
411 		case (BPF_JMP | EBPF_JSGE | BPF_K):
412 			BPF_JMP_CND_IMM(reg, ins, >=, int64_t);
413 			break;
414 		case (BPF_JMP | EBPF_JSLE | BPF_K):
415 			BPF_JMP_CND_IMM(reg, ins, <=, int64_t);
416 			break;
417 		case (BPF_JMP | BPF_JSET | BPF_K):
418 			BPF_JMP_CND_IMM(reg, ins, &, uint64_t);
419 			break;
420 		/* jump REG instructions */
421 		case (BPF_JMP | BPF_JEQ | BPF_X):
422 			BPF_JMP_CND_REG(reg, ins, ==, uint64_t);
423 			break;
424 		case (BPF_JMP | EBPF_JNE | BPF_X):
425 			BPF_JMP_CND_REG(reg, ins, !=, uint64_t);
426 			break;
427 		case (BPF_JMP | BPF_JGT | BPF_X):
428 			BPF_JMP_CND_REG(reg, ins, >, uint64_t);
429 			break;
430 		case (BPF_JMP | EBPF_JLT | BPF_X):
431 			BPF_JMP_CND_REG(reg, ins, <, uint64_t);
432 			break;
433 		case (BPF_JMP | BPF_JGE | BPF_X):
434 			BPF_JMP_CND_REG(reg, ins, >=, uint64_t);
435 			break;
436 		case (BPF_JMP | EBPF_JLE | BPF_X):
437 			BPF_JMP_CND_REG(reg, ins, <=, uint64_t);
438 			break;
439 		case (BPF_JMP | EBPF_JSGT | BPF_X):
440 			BPF_JMP_CND_REG(reg, ins, >, int64_t);
441 			break;
442 		case (BPF_JMP | EBPF_JSLT | BPF_X):
443 			BPF_JMP_CND_REG(reg, ins, <, int64_t);
444 			break;
445 		case (BPF_JMP | EBPF_JSGE | BPF_X):
446 			BPF_JMP_CND_REG(reg, ins, >=, int64_t);
447 			break;
448 		case (BPF_JMP | EBPF_JSLE | BPF_X):
449 			BPF_JMP_CND_REG(reg, ins, <=, int64_t);
450 			break;
451 		case (BPF_JMP | BPF_JSET | BPF_X):
452 			BPF_JMP_CND_REG(reg, ins, &, uint64_t);
453 			break;
454 		/* call instructions */
455 		case (BPF_JMP | EBPF_CALL):
456 			reg[EBPF_REG_0] = bpf->prm.xsym[ins->imm].func.val(
457 				reg[EBPF_REG_1], reg[EBPF_REG_2],
458 				reg[EBPF_REG_3], reg[EBPF_REG_4],
459 				reg[EBPF_REG_5]);
460 			break;
461 		/* return instruction */
462 		case (BPF_JMP | EBPF_EXIT):
463 			return reg[EBPF_REG_0];
464 		default:
465 			RTE_BPF_LOG(ERR,
466 				"%s(%p): invalid opcode %#x at pc: %#zx;\n",
467 				__func__, bpf, ins->code,
468 				(uintptr_t)ins - (uintptr_t)bpf->prm.ins);
469 			return 0;
470 		}
471 	}
472 
473 	/* should never be reached */
474 	RTE_VERIFY(0);
475 	return 0;
476 }
477 
478 uint32_t
479 rte_bpf_exec_burst(const struct rte_bpf *bpf, void *ctx[], uint64_t rc[],
480 	uint32_t num)
481 {
482 	uint32_t i;
483 	uint64_t reg[EBPF_REG_NUM];
484 	uint64_t stack[MAX_BPF_STACK_SIZE / sizeof(uint64_t)];
485 
486 	for (i = 0; i != num; i++) {
487 
488 		reg[EBPF_REG_1] = (uintptr_t)ctx[i];
489 		reg[EBPF_REG_10] = (uintptr_t)(stack + RTE_DIM(stack));
490 
491 		rc[i] = bpf_exec(bpf, reg);
492 	}
493 
494 	return i;
495 }
496 
497 uint64_t
498 rte_bpf_exec(const struct rte_bpf *bpf, void *ctx)
499 {
500 	uint64_t rc;
501 
502 	rte_bpf_exec_burst(bpf, &ctx, &rc, 1);
503 	return rc;
504 }
505