diff options
Diffstat (limited to 'debug/disasm.c')
| -rw-r--r-- | debug/disasm.c | 281 |
1 files changed, 281 insertions, 0 deletions
diff --git a/debug/disasm.c b/debug/disasm.c new file mode 100644 index 0000000..fae96b7 --- /dev/null +++ b/debug/disasm.c @@ -0,0 +1,281 @@ +/* SPDX-License-Identifier: GPL-3.0-or-later + * Copyright 2023 Red Hat GmbH + * Author: Alice Frosi <afrosi@redhat.com> + */ + +#define _GNU_SOURCE +#include <stdbool.h> +#include <stddef.h> +#include <stdio.h> +#include <string.h> +#include <unistd.h> + +#include <linux/filter.h> + +#include "disasm.h" + +/* From linux tools/bpf/bpf_dbg.c */ +#define BPF_LDX_B (BPF_LDX | BPF_B) +#define BPF_LDX_W (BPF_LDX | BPF_W) +#define BPF_JMP_JA (BPF_JMP | BPF_JA) +#define BPF_JMP_JEQ (BPF_JMP | BPF_JEQ) +#define BPF_JMP_JGT (BPF_JMP | BPF_JGT) +#define BPF_JMP_JGE (BPF_JMP | BPF_JGE) +#define BPF_JMP_JSET (BPF_JMP | BPF_JSET) +#define BPF_ALU_ADD (BPF_ALU | BPF_ADD) +#define BPF_ALU_SUB (BPF_ALU | BPF_SUB) +#define BPF_ALU_MUL (BPF_ALU | BPF_MUL) +#define BPF_ALU_DIV (BPF_ALU | BPF_DIV) +#define BPF_ALU_MOD (BPF_ALU | BPF_MOD) +#define BPF_ALU_NEG (BPF_ALU | BPF_NEG) +#define BPF_ALU_AND (BPF_ALU | BPF_AND) +#define BPF_ALU_OR (BPF_ALU | BPF_OR) +#define BPF_ALU_XOR (BPF_ALU | BPF_XOR) +#define BPF_ALU_LSH (BPF_ALU | BPF_LSH) +#define BPF_ALU_RSH (BPF_ALU | BPF_RSH) +#define BPF_MISC_TAX (BPF_MISC | BPF_TAX) +#define BPF_MISC_TXA (BPF_MISC | BPF_TXA) +#define BPF_LD_B (BPF_LD | BPF_B) +#define BPF_LD_H (BPF_LD | BPF_H) +#define BPF_LD_W (BPF_LD | BPF_W) +static const char *const op_table[] = { + [BPF_ST] = "st", [BPF_STX] = "stx", [BPF_LD_B] = "ldb", + [BPF_LD_H] = "ldh", [BPF_LD_W] = "ld", [BPF_LDX] = "ldx", + [BPF_LDX_B] = "ldxb", [BPF_JMP_JA] = "ja", [BPF_JMP_JEQ] = "jeq", + [BPF_JMP_JGT] = "jgt", [BPF_JMP_JGE] = "jge", [BPF_JMP_JSET] = "jset", + [BPF_ALU_ADD] = "add", [BPF_ALU_SUB] = "sub", [BPF_ALU_MUL] = "mul", + [BPF_ALU_DIV] = "div", [BPF_ALU_MOD] = "mod", [BPF_ALU_NEG] = "neg", + [BPF_ALU_AND] = "and", [BPF_ALU_OR] = "or", [BPF_ALU_XOR] = "xor", + [BPF_ALU_LSH] = "lsh", [BPF_ALU_RSH] = "rsh", [BPF_MISC_TAX] = "tax", + [BPF_MISC_TXA] = "txa", [BPF_RET] = "ret", +}; + +void bpf_disasm(const struct sock_filter f, unsigned int i) +{ + const char *op, *fmt; + int val = f.k; + char buf[256]; + + switch (f.code) { + case BPF_RET | BPF_K: + op = op_table[BPF_RET]; + fmt = "#%#x"; + break; + case BPF_RET | BPF_A: + op = op_table[BPF_RET]; + fmt = "a"; + break; + case BPF_RET | BPF_X: + op = op_table[BPF_RET]; + fmt = "x"; + break; + case BPF_MISC_TAX: + op = op_table[BPF_MISC_TAX]; + fmt = ""; + break; + case BPF_MISC_TXA: + op = op_table[BPF_MISC_TXA]; + fmt = ""; + break; + case BPF_ST: + op = op_table[BPF_ST]; + fmt = "M[%d]"; + break; + case BPF_STX: + op = op_table[BPF_STX]; + fmt = "M[%d]"; + break; + case BPF_LD_W | BPF_ABS: + op = op_table[BPF_LD_W]; + fmt = "[%d]"; + break; + case BPF_LD_H | BPF_ABS: + op = op_table[BPF_LD_H]; + fmt = "[%d]"; + break; + case BPF_LD_B | BPF_ABS: + op = op_table[BPF_LD_B]; + fmt = "[%d]"; + break; + case BPF_LD_W | BPF_LEN: + op = op_table[BPF_LD_W]; + fmt = "#len"; + break; + case BPF_LD_W | BPF_IND: + op = op_table[BPF_LD_W]; + fmt = "[x+%d]"; + break; + case BPF_LD_H | BPF_IND: + op = op_table[BPF_LD_H]; + fmt = "[x+%d]"; + break; + case BPF_LD_B | BPF_IND: + op = op_table[BPF_LD_B]; + fmt = "[x+%d]"; + break; + case BPF_LD | BPF_IMM: + op = op_table[BPF_LD_W]; + fmt = "#%#x"; + break; + case BPF_LDX | BPF_IMM: + op = op_table[BPF_LDX]; + fmt = "#%#x"; + break; + case BPF_LDX_B | BPF_MSH: + op = op_table[BPF_LDX_B]; + fmt = "4*([%d]&0xf)"; + break; + case BPF_LD | BPF_MEM: + op = op_table[BPF_LD_W]; + fmt = "M[%d]"; + break; + case BPF_LDX | BPF_MEM: + op = op_table[BPF_LDX]; + fmt = "M[%d]"; + break; + case BPF_JMP_JA: + op = op_table[BPF_JMP_JA]; + fmt = "%d"; + val = i + 1 + f.k; + break; + case BPF_JMP_JGT | BPF_X: + op = op_table[BPF_JMP_JGT]; + fmt = "x"; + break; + case BPF_JMP_JGT | BPF_K: + op = op_table[BPF_JMP_JGT]; + fmt = "#%#x"; + break; + case BPF_JMP_JGE | BPF_X: + op = op_table[BPF_JMP_JGE]; + fmt = "x"; + break; + case BPF_JMP_JGE | BPF_K: + op = op_table[BPF_JMP_JGE]; + fmt = "#%#x"; + break; + case BPF_JMP_JEQ | BPF_X: + op = op_table[BPF_JMP_JEQ]; + fmt = "x"; + break; + case BPF_JMP_JEQ | BPF_K: + op = op_table[BPF_JMP_JEQ]; + fmt = "#%#x"; + break; + case BPF_JMP_JSET | BPF_X: + op = op_table[BPF_JMP_JSET]; + fmt = "x"; + break; + case BPF_JMP_JSET | BPF_K: + op = op_table[BPF_JMP_JSET]; + fmt = "#%#x"; + break; + case BPF_ALU_NEG: + op = op_table[BPF_ALU_NEG]; + fmt = ""; + break; + case BPF_ALU_LSH | BPF_X: + op = op_table[BPF_ALU_LSH]; + fmt = "x"; + break; + case BPF_ALU_LSH | BPF_K: + op = op_table[BPF_ALU_LSH]; + fmt = "#%d"; + break; + case BPF_ALU_RSH | BPF_X: + op = op_table[BPF_ALU_RSH]; + fmt = "x"; + break; + case BPF_ALU_RSH | BPF_K: + op = op_table[BPF_ALU_RSH]; + fmt = "#%d"; + break; + case BPF_ALU_ADD | BPF_X: + op = op_table[BPF_ALU_ADD]; + fmt = "x"; + break; + case BPF_ALU_ADD | BPF_K: + op = op_table[BPF_ALU_ADD]; + fmt = "#%d"; + break; + case BPF_ALU_SUB | BPF_X: + op = op_table[BPF_ALU_SUB]; + fmt = "x"; + break; + case BPF_ALU_SUB | BPF_K: + op = op_table[BPF_ALU_SUB]; + fmt = "#%d"; + break; + case BPF_ALU_MUL | BPF_X: + op = op_table[BPF_ALU_MUL]; + fmt = "x"; + break; + case BPF_ALU_MUL | BPF_K: + op = op_table[BPF_ALU_MUL]; + fmt = "#%d"; + break; + case BPF_ALU_DIV | BPF_X: + op = op_table[BPF_ALU_DIV]; + fmt = "x"; + break; + case BPF_ALU_DIV | BPF_K: + op = op_table[BPF_ALU_DIV]; + fmt = "#%d"; + break; + case BPF_ALU_MOD | BPF_X: + op = op_table[BPF_ALU_MOD]; + fmt = "x"; + break; + case BPF_ALU_MOD | BPF_K: + op = op_table[BPF_ALU_MOD]; + fmt = "#%d"; + break; + case BPF_ALU_AND | BPF_X: + op = op_table[BPF_ALU_AND]; + fmt = "x"; + break; + case BPF_ALU_AND | BPF_K: + op = op_table[BPF_ALU_AND]; + fmt = "#%#x"; + break; + case BPF_ALU_OR | BPF_X: + op = op_table[BPF_ALU_OR]; + fmt = "x"; + break; + case BPF_ALU_OR | BPF_K: + op = op_table[BPF_ALU_OR]; + fmt = "#%#x"; + break; + case BPF_ALU_XOR | BPF_X: + op = op_table[BPF_ALU_XOR]; + fmt = "x"; + break; + case BPF_ALU_XOR | BPF_K: + op = op_table[BPF_ALU_XOR]; + fmt = "#%#x"; + break; + default: + op = "nosup"; + fmt = "%#x"; + val = f.code; + break; + } + + memset(buf, 0, sizeof(buf)); + snprintf(buf, sizeof(buf), fmt, val); + buf[sizeof(buf) - 1] = 0; + + if ((BPF_CLASS(f.code) == BPF_JMP && BPF_OP(f.code) != BPF_JA)) { + printf("l%d:\t%s %s, l%d, l%d\n", i, op, buf, i + 1 + f.jt, + i + 1 + f.jf); + } else { + printf("l%d:\t%s %s\n", i, op, buf); + } +} + +void bpf_disasm_all(const struct sock_filter *f, unsigned int len) +{ + unsigned int i; + for (i = 0; i < len; i++) + bpf_disasm(f[i], i); +} |