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7e22077d0c
When compiling larger programs with bpf_asm, it's possible to accidentally exceed jt/jf range, in which case it won't complain, but rather silently emit a truncated offset, leading to a "happy debugging" situation. Add a warning to help detecting such issues. It could be made an error instead, but this might break compilation of existing code (which might be working by accident). Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191107100349.88976-1-iii@linux.ibm.com
666 lines
16 KiB
Text
666 lines
16 KiB
Text
/*
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* BPF asm code parser
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*
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* This program is free software; you can distribute it and/or modify
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* it under the terms of the GNU General Public License as published
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* by the Free Software Foundation; either version 2 of the License,
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* or (at your option) any later version.
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*
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* Syntax kept close to:
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*
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* Steven McCanne and Van Jacobson. 1993. The BSD packet filter: a new
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* architecture for user-level packet capture. In Proceedings of the
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* USENIX Winter 1993 Conference Proceedings on USENIX Winter 1993
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* Conference Proceedings (USENIX'93). USENIX Association, Berkeley,
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* CA, USA, 2-2.
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*
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* Copyright 2013 Daniel Borkmann <borkmann@redhat.com>
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* Licensed under the GNU General Public License, version 2.0 (GPLv2)
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*/
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%{
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#include <stdio.h>
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#include <string.h>
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#include <stdint.h>
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#include <stdlib.h>
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#include <stdbool.h>
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#include <unistd.h>
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#include <errno.h>
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#include <assert.h>
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#include <linux/filter.h>
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#include "bpf_exp.yacc.h"
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enum jmp_type { JTL, JFL, JKL };
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extern FILE *yyin;
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extern int yylineno;
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extern int yylex(void);
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extern void yyerror(const char *str);
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extern void bpf_asm_compile(FILE *fp, bool cstyle);
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static void bpf_set_curr_instr(uint16_t op, uint8_t jt, uint8_t jf, uint32_t k);
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static void bpf_set_curr_label(char *label);
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static void bpf_set_jmp_label(char *label, enum jmp_type type);
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%}
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%union {
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char *label;
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uint32_t number;
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}
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%token OP_LDB OP_LDH OP_LD OP_LDX OP_ST OP_STX OP_JMP OP_JEQ OP_JGT OP_JGE
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%token OP_JSET OP_ADD OP_SUB OP_MUL OP_DIV OP_AND OP_OR OP_XOR OP_LSH OP_RSH
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%token OP_RET OP_TAX OP_TXA OP_LDXB OP_MOD OP_NEG OP_JNEQ OP_JLT OP_JLE OP_LDI
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%token OP_LDXI
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%token K_PKT_LEN
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%token ':' ',' '[' ']' '(' ')' 'x' 'a' '+' 'M' '*' '&' '#' '%'
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%token extension number label
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%type <label> label
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%type <number> extension
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%type <number> number
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%%
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prog
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: line
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| prog line
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;
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line
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: instr
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| labelled_instr
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;
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labelled_instr
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: labelled instr
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;
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instr
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: ldb
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| ldh
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| ld
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| ldi
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| ldx
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| ldxi
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| st
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| stx
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| jmp
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| jeq
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| jneq
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| jlt
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| jle
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| jgt
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| jge
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| jset
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| add
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| sub
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| mul
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| div
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| mod
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| neg
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| and
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| or
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| xor
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| lsh
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| rsh
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| ret
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| tax
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| txa
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;
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labelled
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: label ':' { bpf_set_curr_label($1); }
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;
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ldb
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: OP_LDB '[' 'x' '+' number ']' {
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bpf_set_curr_instr(BPF_LD | BPF_B | BPF_IND, 0, 0, $5); }
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| OP_LDB '[' '%' 'x' '+' number ']' {
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bpf_set_curr_instr(BPF_LD | BPF_B | BPF_IND, 0, 0, $6); }
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| OP_LDB '[' number ']' {
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bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, $3); }
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| OP_LDB extension {
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bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
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SKF_AD_OFF + $2); }
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;
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ldh
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: OP_LDH '[' 'x' '+' number ']' {
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bpf_set_curr_instr(BPF_LD | BPF_H | BPF_IND, 0, 0, $5); }
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| OP_LDH '[' '%' 'x' '+' number ']' {
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bpf_set_curr_instr(BPF_LD | BPF_H | BPF_IND, 0, 0, $6); }
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| OP_LDH '[' number ']' {
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bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, $3); }
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| OP_LDH extension {
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bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
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SKF_AD_OFF + $2); }
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;
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ldi
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: OP_LDI '#' number {
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bpf_set_curr_instr(BPF_LD | BPF_IMM, 0, 0, $3); }
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| OP_LDI number {
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bpf_set_curr_instr(BPF_LD | BPF_IMM, 0, 0, $2); }
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;
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ld
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: OP_LD '#' number {
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bpf_set_curr_instr(BPF_LD | BPF_IMM, 0, 0, $3); }
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| OP_LD K_PKT_LEN {
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bpf_set_curr_instr(BPF_LD | BPF_W | BPF_LEN, 0, 0, 0); }
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| OP_LD extension {
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bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
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SKF_AD_OFF + $2); }
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| OP_LD 'M' '[' number ']' {
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bpf_set_curr_instr(BPF_LD | BPF_MEM, 0, 0, $4); }
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| OP_LD '[' 'x' '+' number ']' {
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bpf_set_curr_instr(BPF_LD | BPF_W | BPF_IND, 0, 0, $5); }
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| OP_LD '[' '%' 'x' '+' number ']' {
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bpf_set_curr_instr(BPF_LD | BPF_W | BPF_IND, 0, 0, $6); }
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| OP_LD '[' number ']' {
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bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, $3); }
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;
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ldxi
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: OP_LDXI '#' number {
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bpf_set_curr_instr(BPF_LDX | BPF_IMM, 0, 0, $3); }
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| OP_LDXI number {
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bpf_set_curr_instr(BPF_LDX | BPF_IMM, 0, 0, $2); }
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;
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ldx
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: OP_LDX '#' number {
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bpf_set_curr_instr(BPF_LDX | BPF_IMM, 0, 0, $3); }
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| OP_LDX K_PKT_LEN {
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bpf_set_curr_instr(BPF_LDX | BPF_W | BPF_LEN, 0, 0, 0); }
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| OP_LDX 'M' '[' number ']' {
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bpf_set_curr_instr(BPF_LDX | BPF_MEM, 0, 0, $4); }
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| OP_LDXB number '*' '(' '[' number ']' '&' number ')' {
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if ($2 != 4 || $9 != 0xf) {
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fprintf(stderr, "ldxb offset not supported!\n");
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exit(0);
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} else {
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bpf_set_curr_instr(BPF_LDX | BPF_MSH | BPF_B, 0, 0, $6); } }
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| OP_LDX number '*' '(' '[' number ']' '&' number ')' {
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if ($2 != 4 || $9 != 0xf) {
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fprintf(stderr, "ldxb offset not supported!\n");
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exit(0);
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} else {
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bpf_set_curr_instr(BPF_LDX | BPF_MSH | BPF_B, 0, 0, $6); } }
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;
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st
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: OP_ST 'M' '[' number ']' {
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bpf_set_curr_instr(BPF_ST, 0, 0, $4); }
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;
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stx
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: OP_STX 'M' '[' number ']' {
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bpf_set_curr_instr(BPF_STX, 0, 0, $4); }
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;
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jmp
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: OP_JMP label {
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bpf_set_jmp_label($2, JKL);
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bpf_set_curr_instr(BPF_JMP | BPF_JA, 0, 0, 0); }
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;
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jeq
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: OP_JEQ '#' number ',' label ',' label {
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bpf_set_jmp_label($5, JTL);
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bpf_set_jmp_label($7, JFL);
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bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_K, 0, 0, $3); }
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| OP_JEQ 'x' ',' label ',' label {
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bpf_set_jmp_label($4, JTL);
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bpf_set_jmp_label($6, JFL);
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bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); }
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| OP_JEQ '%' 'x' ',' label ',' label {
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bpf_set_jmp_label($5, JTL);
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bpf_set_jmp_label($7, JFL);
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bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); }
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| OP_JEQ '#' number ',' label {
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bpf_set_jmp_label($5, JTL);
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bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_K, 0, 0, $3); }
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| OP_JEQ 'x' ',' label {
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bpf_set_jmp_label($4, JTL);
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bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); }
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| OP_JEQ '%' 'x' ',' label {
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bpf_set_jmp_label($5, JTL);
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bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); }
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;
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jneq
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: OP_JNEQ '#' number ',' label {
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bpf_set_jmp_label($5, JFL);
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bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_K, 0, 0, $3); }
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| OP_JNEQ 'x' ',' label {
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bpf_set_jmp_label($4, JFL);
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bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); }
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| OP_JNEQ '%' 'x' ',' label {
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bpf_set_jmp_label($5, JFL);
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bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); }
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;
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jlt
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: OP_JLT '#' number ',' label {
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bpf_set_jmp_label($5, JFL);
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bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_K, 0, 0, $3); }
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| OP_JLT 'x' ',' label {
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bpf_set_jmp_label($4, JFL);
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bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); }
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| OP_JLT '%' 'x' ',' label {
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bpf_set_jmp_label($5, JFL);
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bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); }
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;
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jle
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: OP_JLE '#' number ',' label {
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bpf_set_jmp_label($5, JFL);
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bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_K, 0, 0, $3); }
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| OP_JLE 'x' ',' label {
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bpf_set_jmp_label($4, JFL);
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bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); }
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| OP_JLE '%' 'x' ',' label {
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bpf_set_jmp_label($5, JFL);
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bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); }
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;
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jgt
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: OP_JGT '#' number ',' label ',' label {
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bpf_set_jmp_label($5, JTL);
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bpf_set_jmp_label($7, JFL);
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bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_K, 0, 0, $3); }
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| OP_JGT 'x' ',' label ',' label {
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bpf_set_jmp_label($4, JTL);
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bpf_set_jmp_label($6, JFL);
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bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); }
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| OP_JGT '%' 'x' ',' label ',' label {
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bpf_set_jmp_label($5, JTL);
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bpf_set_jmp_label($7, JFL);
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bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); }
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| OP_JGT '#' number ',' label {
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bpf_set_jmp_label($5, JTL);
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bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_K, 0, 0, $3); }
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| OP_JGT 'x' ',' label {
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bpf_set_jmp_label($4, JTL);
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bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); }
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| OP_JGT '%' 'x' ',' label {
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bpf_set_jmp_label($5, JTL);
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bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); }
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;
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jge
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: OP_JGE '#' number ',' label ',' label {
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bpf_set_jmp_label($5, JTL);
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bpf_set_jmp_label($7, JFL);
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bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_K, 0, 0, $3); }
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| OP_JGE 'x' ',' label ',' label {
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bpf_set_jmp_label($4, JTL);
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bpf_set_jmp_label($6, JFL);
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bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); }
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| OP_JGE '%' 'x' ',' label ',' label {
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bpf_set_jmp_label($5, JTL);
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bpf_set_jmp_label($7, JFL);
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bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); }
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| OP_JGE '#' number ',' label {
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bpf_set_jmp_label($5, JTL);
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bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_K, 0, 0, $3); }
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| OP_JGE 'x' ',' label {
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bpf_set_jmp_label($4, JTL);
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bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); }
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| OP_JGE '%' 'x' ',' label {
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bpf_set_jmp_label($5, JTL);
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bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); }
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;
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jset
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: OP_JSET '#' number ',' label ',' label {
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bpf_set_jmp_label($5, JTL);
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bpf_set_jmp_label($7, JFL);
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bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_K, 0, 0, $3); }
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| OP_JSET 'x' ',' label ',' label {
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bpf_set_jmp_label($4, JTL);
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bpf_set_jmp_label($6, JFL);
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bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_X, 0, 0, 0); }
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| OP_JSET '%' 'x' ',' label ',' label {
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bpf_set_jmp_label($5, JTL);
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bpf_set_jmp_label($7, JFL);
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bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_X, 0, 0, 0); }
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| OP_JSET '#' number ',' label {
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bpf_set_jmp_label($5, JTL);
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bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_K, 0, 0, $3); }
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| OP_JSET 'x' ',' label {
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bpf_set_jmp_label($4, JTL);
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bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_X, 0, 0, 0); }
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| OP_JSET '%' 'x' ',' label {
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bpf_set_jmp_label($5, JTL);
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bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_X, 0, 0, 0); }
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;
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add
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: OP_ADD '#' number {
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bpf_set_curr_instr(BPF_ALU | BPF_ADD | BPF_K, 0, 0, $3); }
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| OP_ADD 'x' {
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bpf_set_curr_instr(BPF_ALU | BPF_ADD | BPF_X, 0, 0, 0); }
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| OP_ADD '%' 'x' {
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bpf_set_curr_instr(BPF_ALU | BPF_ADD | BPF_X, 0, 0, 0); }
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;
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sub
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: OP_SUB '#' number {
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bpf_set_curr_instr(BPF_ALU | BPF_SUB | BPF_K, 0, 0, $3); }
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| OP_SUB 'x' {
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bpf_set_curr_instr(BPF_ALU | BPF_SUB | BPF_X, 0, 0, 0); }
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| OP_SUB '%' 'x' {
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bpf_set_curr_instr(BPF_ALU | BPF_SUB | BPF_X, 0, 0, 0); }
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;
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mul
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: OP_MUL '#' number {
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bpf_set_curr_instr(BPF_ALU | BPF_MUL | BPF_K, 0, 0, $3); }
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| OP_MUL 'x' {
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bpf_set_curr_instr(BPF_ALU | BPF_MUL | BPF_X, 0, 0, 0); }
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| OP_MUL '%' 'x' {
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bpf_set_curr_instr(BPF_ALU | BPF_MUL | BPF_X, 0, 0, 0); }
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;
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div
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: OP_DIV '#' number {
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bpf_set_curr_instr(BPF_ALU | BPF_DIV | BPF_K, 0, 0, $3); }
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| OP_DIV 'x' {
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bpf_set_curr_instr(BPF_ALU | BPF_DIV | BPF_X, 0, 0, 0); }
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| OP_DIV '%' 'x' {
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bpf_set_curr_instr(BPF_ALU | BPF_DIV | BPF_X, 0, 0, 0); }
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;
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mod
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: OP_MOD '#' number {
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bpf_set_curr_instr(BPF_ALU | BPF_MOD | BPF_K, 0, 0, $3); }
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| OP_MOD 'x' {
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bpf_set_curr_instr(BPF_ALU | BPF_MOD | BPF_X, 0, 0, 0); }
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| OP_MOD '%' 'x' {
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bpf_set_curr_instr(BPF_ALU | BPF_MOD | BPF_X, 0, 0, 0); }
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;
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neg
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: OP_NEG {
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bpf_set_curr_instr(BPF_ALU | BPF_NEG, 0, 0, 0); }
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;
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and
|
|
: OP_AND '#' number {
|
|
bpf_set_curr_instr(BPF_ALU | BPF_AND | BPF_K, 0, 0, $3); }
|
|
| OP_AND 'x' {
|
|
bpf_set_curr_instr(BPF_ALU | BPF_AND | BPF_X, 0, 0, 0); }
|
|
| OP_AND '%' 'x' {
|
|
bpf_set_curr_instr(BPF_ALU | BPF_AND | BPF_X, 0, 0, 0); }
|
|
;
|
|
|
|
or
|
|
: OP_OR '#' number {
|
|
bpf_set_curr_instr(BPF_ALU | BPF_OR | BPF_K, 0, 0, $3); }
|
|
| OP_OR 'x' {
|
|
bpf_set_curr_instr(BPF_ALU | BPF_OR | BPF_X, 0, 0, 0); }
|
|
| OP_OR '%' 'x' {
|
|
bpf_set_curr_instr(BPF_ALU | BPF_OR | BPF_X, 0, 0, 0); }
|
|
;
|
|
|
|
xor
|
|
: OP_XOR '#' number {
|
|
bpf_set_curr_instr(BPF_ALU | BPF_XOR | BPF_K, 0, 0, $3); }
|
|
| OP_XOR 'x' {
|
|
bpf_set_curr_instr(BPF_ALU | BPF_XOR | BPF_X, 0, 0, 0); }
|
|
| OP_XOR '%' 'x' {
|
|
bpf_set_curr_instr(BPF_ALU | BPF_XOR | BPF_X, 0, 0, 0); }
|
|
;
|
|
|
|
lsh
|
|
: OP_LSH '#' number {
|
|
bpf_set_curr_instr(BPF_ALU | BPF_LSH | BPF_K, 0, 0, $3); }
|
|
| OP_LSH 'x' {
|
|
bpf_set_curr_instr(BPF_ALU | BPF_LSH | BPF_X, 0, 0, 0); }
|
|
| OP_LSH '%' 'x' {
|
|
bpf_set_curr_instr(BPF_ALU | BPF_LSH | BPF_X, 0, 0, 0); }
|
|
;
|
|
|
|
rsh
|
|
: OP_RSH '#' number {
|
|
bpf_set_curr_instr(BPF_ALU | BPF_RSH | BPF_K, 0, 0, $3); }
|
|
| OP_RSH 'x' {
|
|
bpf_set_curr_instr(BPF_ALU | BPF_RSH | BPF_X, 0, 0, 0); }
|
|
| OP_RSH '%' 'x' {
|
|
bpf_set_curr_instr(BPF_ALU | BPF_RSH | BPF_X, 0, 0, 0); }
|
|
;
|
|
|
|
ret
|
|
: OP_RET 'a' {
|
|
bpf_set_curr_instr(BPF_RET | BPF_A, 0, 0, 0); }
|
|
| OP_RET '%' 'a' {
|
|
bpf_set_curr_instr(BPF_RET | BPF_A, 0, 0, 0); }
|
|
| OP_RET 'x' {
|
|
bpf_set_curr_instr(BPF_RET | BPF_X, 0, 0, 0); }
|
|
| OP_RET '%' 'x' {
|
|
bpf_set_curr_instr(BPF_RET | BPF_X, 0, 0, 0); }
|
|
| OP_RET '#' number {
|
|
bpf_set_curr_instr(BPF_RET | BPF_K, 0, 0, $3); }
|
|
;
|
|
|
|
tax
|
|
: OP_TAX {
|
|
bpf_set_curr_instr(BPF_MISC | BPF_TAX, 0, 0, 0); }
|
|
;
|
|
|
|
txa
|
|
: OP_TXA {
|
|
bpf_set_curr_instr(BPF_MISC | BPF_TXA, 0, 0, 0); }
|
|
;
|
|
|
|
%%
|
|
|
|
static int curr_instr = 0;
|
|
static struct sock_filter out[BPF_MAXINSNS];
|
|
static char **labels, **labels_jt, **labels_jf, **labels_k;
|
|
|
|
static void bpf_assert_max(void)
|
|
{
|
|
if (curr_instr >= BPF_MAXINSNS) {
|
|
fprintf(stderr, "only max %u insns allowed!\n", BPF_MAXINSNS);
|
|
exit(0);
|
|
}
|
|
}
|
|
|
|
static void bpf_set_curr_instr(uint16_t code, uint8_t jt, uint8_t jf,
|
|
uint32_t k)
|
|
{
|
|
bpf_assert_max();
|
|
out[curr_instr].code = code;
|
|
out[curr_instr].jt = jt;
|
|
out[curr_instr].jf = jf;
|
|
out[curr_instr].k = k;
|
|
curr_instr++;
|
|
}
|
|
|
|
static void bpf_set_curr_label(char *label)
|
|
{
|
|
bpf_assert_max();
|
|
labels[curr_instr] = label;
|
|
}
|
|
|
|
static void bpf_set_jmp_label(char *label, enum jmp_type type)
|
|
{
|
|
bpf_assert_max();
|
|
switch (type) {
|
|
case JTL:
|
|
labels_jt[curr_instr] = label;
|
|
break;
|
|
case JFL:
|
|
labels_jf[curr_instr] = label;
|
|
break;
|
|
case JKL:
|
|
labels_k[curr_instr] = label;
|
|
break;
|
|
}
|
|
}
|
|
|
|
static int bpf_find_insns_offset(const char *label)
|
|
{
|
|
int i, max = curr_instr, ret = -ENOENT;
|
|
|
|
for (i = 0; i < max; i++) {
|
|
if (labels[i] && !strcmp(label, labels[i])) {
|
|
ret = i;
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (ret == -ENOENT) {
|
|
fprintf(stderr, "no such label \'%s\'!\n", label);
|
|
exit(0);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static void bpf_stage_1_insert_insns(void)
|
|
{
|
|
yyparse();
|
|
}
|
|
|
|
static void bpf_reduce_k_jumps(void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < curr_instr; i++) {
|
|
if (labels_k[i]) {
|
|
int off = bpf_find_insns_offset(labels_k[i]);
|
|
out[i].k = (uint32_t) (off - i - 1);
|
|
}
|
|
}
|
|
}
|
|
|
|
static uint8_t bpf_encode_jt_jf_offset(int off, int i)
|
|
{
|
|
int delta = off - i - 1;
|
|
|
|
if (delta < 0 || delta > 255)
|
|
fprintf(stderr, "warning: insn #%d jumps to insn #%d, "
|
|
"which is out of range\n", i, off);
|
|
return (uint8_t) delta;
|
|
}
|
|
|
|
static void bpf_reduce_jt_jumps(void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < curr_instr; i++) {
|
|
if (labels_jt[i]) {
|
|
int off = bpf_find_insns_offset(labels_jt[i]);
|
|
out[i].jt = bpf_encode_jt_jf_offset(off, i);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void bpf_reduce_jf_jumps(void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < curr_instr; i++) {
|
|
if (labels_jf[i]) {
|
|
int off = bpf_find_insns_offset(labels_jf[i]);
|
|
out[i].jf = bpf_encode_jt_jf_offset(off, i);
|
|
}
|
|
}
|
|
}
|
|
|
|
static void bpf_stage_2_reduce_labels(void)
|
|
{
|
|
bpf_reduce_k_jumps();
|
|
bpf_reduce_jt_jumps();
|
|
bpf_reduce_jf_jumps();
|
|
}
|
|
|
|
static void bpf_pretty_print_c(void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < curr_instr; i++)
|
|
printf("{ %#04x, %2u, %2u, %#010x },\n", out[i].code,
|
|
out[i].jt, out[i].jf, out[i].k);
|
|
}
|
|
|
|
static void bpf_pretty_print(void)
|
|
{
|
|
int i;
|
|
|
|
printf("%u,", curr_instr);
|
|
for (i = 0; i < curr_instr; i++)
|
|
printf("%u %u %u %u,", out[i].code,
|
|
out[i].jt, out[i].jf, out[i].k);
|
|
printf("\n");
|
|
}
|
|
|
|
static void bpf_init(void)
|
|
{
|
|
memset(out, 0, sizeof(out));
|
|
|
|
labels = calloc(BPF_MAXINSNS, sizeof(*labels));
|
|
assert(labels);
|
|
labels_jt = calloc(BPF_MAXINSNS, sizeof(*labels_jt));
|
|
assert(labels_jt);
|
|
labels_jf = calloc(BPF_MAXINSNS, sizeof(*labels_jf));
|
|
assert(labels_jf);
|
|
labels_k = calloc(BPF_MAXINSNS, sizeof(*labels_k));
|
|
assert(labels_k);
|
|
}
|
|
|
|
static void bpf_destroy_labels(void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < curr_instr; i++) {
|
|
free(labels_jf[i]);
|
|
free(labels_jt[i]);
|
|
free(labels_k[i]);
|
|
free(labels[i]);
|
|
}
|
|
}
|
|
|
|
static void bpf_destroy(void)
|
|
{
|
|
bpf_destroy_labels();
|
|
free(labels_jt);
|
|
free(labels_jf);
|
|
free(labels_k);
|
|
free(labels);
|
|
}
|
|
|
|
void bpf_asm_compile(FILE *fp, bool cstyle)
|
|
{
|
|
yyin = fp;
|
|
|
|
bpf_init();
|
|
bpf_stage_1_insert_insns();
|
|
bpf_stage_2_reduce_labels();
|
|
bpf_destroy();
|
|
|
|
if (cstyle)
|
|
bpf_pretty_print_c();
|
|
else
|
|
bpf_pretty_print();
|
|
|
|
if (fp != stdin)
|
|
fclose(yyin);
|
|
}
|
|
|
|
void yyerror(const char *str)
|
|
{
|
|
fprintf(stderr, "error: %s at line %d\n", str, yylineno);
|
|
exit(1);
|
|
}
|