Eric Lee / smarc-fsl-linux-kernel

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tools/bpf/bpf_exp.y 15.7 KB
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3f356385e   Daniel Borkmann   filter: bpf_asm: ... 
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  /*
   * BPF asm code parser
   *
   * This program is free software; you can distribute it and/or modify
   * it under the terms of the GNU General Public License as published
   * by the Free Software Foundation; either version 2 of the License,
   * or (at your option) any later version.
   *
   * Syntax kept close to:
   *
   * Steven McCanne and Van Jacobson. 1993. The BSD packet filter: a new
   * architecture for user-level packet capture. In Proceedings of the
   * USENIX Winter 1993 Conference Proceedings on USENIX Winter 1993
   * Conference Proceedings (USENIX'93). USENIX Association, Berkeley,
   * CA, USA, 2-2.
   *
   * Copyright 2013 Daniel Borkmann <borkmann@redhat.com>
   * Licensed under the GNU General Public License, version 2.0 (GPLv2)
   */
  
  %{
  
  #include <stdio.h>
  #include <string.h>
  #include <stdint.h>
  #include <stdlib.h>
  #include <stdbool.h>
  #include <unistd.h>
  #include <errno.h>
  #include <assert.h>
  #include <linux/filter.h>
  
  #include "bpf_exp.yacc.h"
  
  enum jmp_type { JTL, JFL, JKL };
  
  extern FILE *yyin;
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  extern int yylineno;
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  extern int yylex(void);
  extern void yyerror(const char *str);
  
  extern void bpf_asm_compile(FILE *fp, bool cstyle);
  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);
  static void bpf_set_jmp_label(char *label, enum jmp_type type);
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  %}
  
  %union {
  	char *label;
  	uint32_t number;
  }
  
  %token OP_LDB OP_LDH OP_LD OP_LDX OP_ST OP_STX OP_JMP OP_JEQ OP_JGT OP_JGE
  %token OP_JSET OP_ADD OP_SUB OP_MUL OP_DIV OP_AND OP_OR OP_XOR OP_LSH OP_RSH
  %token OP_RET OP_TAX OP_TXA OP_LDXB OP_MOD OP_NEG OP_JNEQ OP_JLT OP_JLE OP_LDI
  %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
  
  %%
  
  prog
  	: line
  	| prog line
  	;
  
  line
  	: instr
  	| labelled_instr
  	;
  
  labelled_instr
  	: labelled instr
  	;
  
  instr
  	: ldb
  	| ldh
  	| ld
  	| ldi
  	| ldx
  	| ldxi
  	| st
  	| stx
  	| jmp
  	| jeq
  	| jneq
  	| jlt
  	| jle
  	| jgt
  	| jge
  	| jset
  	| add
  	| sub
  	| mul
  	| div
  	| mod
  	| neg
  	| and
  	| or
  	| xor
  	| lsh
  	| rsh
  	| ret
  	| tax
  	| txa
  	;
  
  labelled
  	: label ':' { bpf_set_curr_label($1); }
  	;
  
  ldb
  	: OP_LDB '[' 'x' '+' number ']' {
  		bpf_set_curr_instr(BPF_LD | BPF_B | BPF_IND, 0, 0, $5); }
  	| OP_LDB '[' '%' 'x' '+' number ']' {
  		bpf_set_curr_instr(BPF_LD | BPF_B | BPF_IND, 0, 0, $6); }
  	| OP_LDB '[' number ']' {
  		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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  	;
  
  ldh
  	: OP_LDH '[' 'x' '+' number ']' {
  		bpf_set_curr_instr(BPF_LD | BPF_H | BPF_IND, 0, 0, $5); }
  	| OP_LDH '[' '%' 'x' '+' number ']' {
  		bpf_set_curr_instr(BPF_LD | BPF_H | BPF_IND, 0, 0, $6); }
  	| OP_LDH '[' number ']' {
  		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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  	;
  
  ldi
  	: OP_LDI '#' number {
  		bpf_set_curr_instr(BPF_LD | BPF_IMM, 0, 0, $3); }
  	| OP_LDI number {
  		bpf_set_curr_instr(BPF_LD | BPF_IMM, 0, 0, $2); }
  	;
  
  ld
  	: OP_LD '#' number {
  		bpf_set_curr_instr(BPF_LD | BPF_IMM, 0, 0, $3); }
  	| OP_LD K_PKT_LEN {
  		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 ']' {
  		bpf_set_curr_instr(BPF_LD | BPF_MEM, 0, 0, $4); }
  	| OP_LD '[' 'x' '+' number ']' {
  		bpf_set_curr_instr(BPF_LD | BPF_W | BPF_IND, 0, 0, $5); }
  	| OP_LD '[' '%' 'x' '+' number ']' {
  		bpf_set_curr_instr(BPF_LD | BPF_W | BPF_IND, 0, 0, $6); }
  	| OP_LD '[' number ']' {
  		bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, $3); }
  	;
  
  ldxi
  	: OP_LDXI '#' number {
  		bpf_set_curr_instr(BPF_LDX | BPF_IMM, 0, 0, $3); }
  	| OP_LDXI number {
  		bpf_set_curr_instr(BPF_LDX | BPF_IMM, 0, 0, $2); }
  	;
  
  ldx
  	: OP_LDX '#' number {
  		bpf_set_curr_instr(BPF_LDX | BPF_IMM, 0, 0, $3); }
  	| OP_LDX K_PKT_LEN {
  		bpf_set_curr_instr(BPF_LDX | BPF_W | BPF_LEN, 0, 0, 0); }
  	| OP_LDX 'M' '[' number ']' {
  		bpf_set_curr_instr(BPF_LDX | BPF_MEM, 0, 0, $4); }
  	| OP_LDXB number '*' '(' '[' number ']' '&' number ')' {
  		if ($2 != 4 || $9 != 0xf) {
  			fprintf(stderr, "ldxb offset not supported!
  ");
  			exit(0);
  		} else {
  			bpf_set_curr_instr(BPF_LDX | BPF_MSH | BPF_B, 0, 0, $6); } }
  	| OP_LDX number '*' '(' '[' number ']' '&' number ')' {
  		if ($2 != 4 || $9 != 0xf) {
  			fprintf(stderr, "ldxb offset not supported!
  ");
  			exit(0);
  		} else {
  			bpf_set_curr_instr(BPF_LDX | BPF_MSH | BPF_B, 0, 0, $6); } }
  	;
  
  st
  	: OP_ST 'M' '[' number ']' {
  		bpf_set_curr_instr(BPF_ST, 0, 0, $4); }
  	;
  
  stx
  	: OP_STX 'M' '[' number ']' {
  		bpf_set_curr_instr(BPF_STX, 0, 0, $4); }
  	;
  
  jmp
  	: OP_JMP label {
  		bpf_set_jmp_label($2, JKL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JA, 0, 0, 0); }
  	;
  
  jeq
  	: OP_JEQ '#' number ',' label ',' label {
  		bpf_set_jmp_label($5, JTL);
  		bpf_set_jmp_label($7, JFL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_K, 0, 0, $3); }
  	| OP_JEQ 'x' ',' label ',' label {
  		bpf_set_jmp_label($4, JTL);
  		bpf_set_jmp_label($6, JFL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); }
  	| OP_JEQ '%' 'x' ',' label ',' label {
  		bpf_set_jmp_label($5, JTL);
  		bpf_set_jmp_label($7, JFL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); }
  	| OP_JEQ '#' number ',' label {
  		bpf_set_jmp_label($5, JTL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_K, 0, 0, $3); }
  	| OP_JEQ 'x' ',' label {
  		bpf_set_jmp_label($4, JTL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); }
  	| OP_JEQ '%' 'x' ',' label {
  		bpf_set_jmp_label($5, JTL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); }
  	;
  
  jneq
  	: OP_JNEQ '#' number ',' label {
  		bpf_set_jmp_label($5, JFL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_K, 0, 0, $3); }
  	| OP_JNEQ 'x' ',' label {
  		bpf_set_jmp_label($4, JFL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); }
  	| OP_JNEQ '%' 'x' ',' label {
  		bpf_set_jmp_label($5, JFL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); }
  	;
  
  jlt
  	: OP_JLT '#' number ',' label {
  		bpf_set_jmp_label($5, JFL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_K, 0, 0, $3); }
  	| OP_JLT 'x' ',' label {
  		bpf_set_jmp_label($4, JFL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); }
  	| OP_JLT '%' 'x' ',' label {
  		bpf_set_jmp_label($5, JFL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); }
  	;
  
  jle
  	: OP_JLE '#' number ',' label {
  		bpf_set_jmp_label($5, JFL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_K, 0, 0, $3); }
  	| OP_JLE 'x' ',' label {
  		bpf_set_jmp_label($4, JFL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); }
  	| OP_JLE '%' 'x' ',' label {
  		bpf_set_jmp_label($5, JFL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); }
  	;
  
  jgt
  	: OP_JGT '#' number ',' label ',' label {
  		bpf_set_jmp_label($5, JTL);
  		bpf_set_jmp_label($7, JFL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_K, 0, 0, $3); }
  	| OP_JGT 'x' ',' label ',' label {
  		bpf_set_jmp_label($4, JTL);
  		bpf_set_jmp_label($6, JFL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); }
  	| OP_JGT '%' 'x' ',' label ',' label {
  		bpf_set_jmp_label($5, JTL);
  		bpf_set_jmp_label($7, JFL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); }
  	| OP_JGT '#' number ',' label {
  		bpf_set_jmp_label($5, JTL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_K, 0, 0, $3); }
  	| OP_JGT 'x' ',' label {
  		bpf_set_jmp_label($4, JTL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); }
  	| OP_JGT '%' 'x' ',' label {
  		bpf_set_jmp_label($5, JTL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); }
  	;
  
  jge
  	: OP_JGE '#' number ',' label ',' label {
  		bpf_set_jmp_label($5, JTL);
  		bpf_set_jmp_label($7, JFL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_K, 0, 0, $3); }
  	| OP_JGE 'x' ',' label ',' label {
  		bpf_set_jmp_label($4, JTL);
  		bpf_set_jmp_label($6, JFL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); }
  	| OP_JGE '%' 'x' ',' label ',' label {
  		bpf_set_jmp_label($5, JTL);
  		bpf_set_jmp_label($7, JFL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); }
  	| OP_JGE '#' number ',' label {
  		bpf_set_jmp_label($5, JTL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_K, 0, 0, $3); }
  	| OP_JGE 'x' ',' label {
  		bpf_set_jmp_label($4, JTL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); }
  	| OP_JGE '%' 'x' ',' label {
  		bpf_set_jmp_label($5, JTL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); }
  	;
  
  jset
  	: OP_JSET '#' number ',' label ',' label {
  		bpf_set_jmp_label($5, JTL);
  		bpf_set_jmp_label($7, JFL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_K, 0, 0, $3); }
  	| OP_JSET 'x' ',' label ',' label {
  		bpf_set_jmp_label($4, JTL);
  		bpf_set_jmp_label($6, JFL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_X, 0, 0, 0); }
  	| OP_JSET '%' 'x' ',' label ',' label {
  		bpf_set_jmp_label($5, JTL);
  		bpf_set_jmp_label($7, JFL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_X, 0, 0, 0); }
  	| OP_JSET '#' number ',' label {
  		bpf_set_jmp_label($5, JTL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_K, 0, 0, $3); }
  	| OP_JSET 'x' ',' label {
  		bpf_set_jmp_label($4, JTL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_X, 0, 0, 0); }
  	| OP_JSET '%' 'x' ',' label {
  		bpf_set_jmp_label($5, JTL);
  		bpf_set_curr_instr(BPF_JMP | BPF_JSET | BPF_X, 0, 0, 0); }
  	;
  
  add
  	: OP_ADD '#' number {
  		bpf_set_curr_instr(BPF_ALU | BPF_ADD | BPF_K, 0, 0, $3); }
  	| OP_ADD 'x' {
  		bpf_set_curr_instr(BPF_ALU | BPF_ADD | BPF_X, 0, 0, 0); }
  	| OP_ADD '%' 'x' {
  		bpf_set_curr_instr(BPF_ALU | BPF_ADD | BPF_X, 0, 0, 0); }
  	;
  
  sub
  	: OP_SUB '#' number {
  		bpf_set_curr_instr(BPF_ALU | BPF_SUB | BPF_K, 0, 0, $3); }
  	| OP_SUB 'x' {
  		bpf_set_curr_instr(BPF_ALU | BPF_SUB | BPF_X, 0, 0, 0); }
  	| OP_SUB '%' 'x' {
  		bpf_set_curr_instr(BPF_ALU | BPF_SUB | BPF_X, 0, 0, 0); }
  	;
  
  mul
  	: OP_MUL '#' number {
  		bpf_set_curr_instr(BPF_ALU | BPF_MUL | BPF_K, 0, 0, $3); }
  	| OP_MUL 'x' {
  		bpf_set_curr_instr(BPF_ALU | BPF_MUL | BPF_X, 0, 0, 0); }
  	| OP_MUL '%' 'x' {
  		bpf_set_curr_instr(BPF_ALU | BPF_MUL | BPF_X, 0, 0, 0); }
  	;
  
  div
  	: OP_DIV '#' number {
  		bpf_set_curr_instr(BPF_ALU | BPF_DIV | BPF_K, 0, 0, $3); }
  	| OP_DIV 'x' {
  		bpf_set_curr_instr(BPF_ALU | BPF_DIV | BPF_X, 0, 0, 0); }
  	| OP_DIV '%' 'x' {
  		bpf_set_curr_instr(BPF_ALU | BPF_DIV | BPF_X, 0, 0, 0); }
  	;
  
  mod
  	: OP_MOD '#' number {
  		bpf_set_curr_instr(BPF_ALU | BPF_MOD | BPF_K, 0, 0, $3); }
  	| OP_MOD 'x' {
  		bpf_set_curr_instr(BPF_ALU | BPF_MOD | BPF_X, 0, 0, 0); }
  	| OP_MOD '%' 'x' {
  		bpf_set_curr_instr(BPF_ALU | BPF_MOD | BPF_X, 0, 0, 0); }
  	;
  
  neg
  	: OP_NEG {
  		bpf_set_curr_instr(BPF_ALU | BPF_NEG, 0, 0, 0); }
  	;
  
  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];
d207cf4c1   Daniel Borkmann   bpf_exp: free dup... 
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  static char **labels, **labels_jt, **labels_jf, **labels_k;
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  static void bpf_assert_max(void)
  {
  	if (curr_instr >= BPF_MAXINSNS) {
  		fprintf(stderr, "only max %u insns allowed!
  ", 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++;
  }
d207cf4c1   Daniel Borkmann   bpf_exp: free dup... 
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  static void bpf_set_curr_label(char *label)
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  {
  	bpf_assert_max();
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  	labels[curr_instr] = label;
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  }
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  static void bpf_set_jmp_label(char *label, enum jmp_type type)
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  {
  	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\'!
  ", 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);
  		}
  	}
  }
7e22077d0   Ilya Leoshkevich   tools, bpf_asm: W... 
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  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
  ", i, off);
  	return (uint8_t) delta;
  }
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  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]);
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  			out[i].jt = bpf_encode_jt_jf_offset(off, i);
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  		}
  	}
  }
  
  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]);
7e22077d0   Ilya Leoshkevich   tools, bpf_asm: W... 
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  			out[i].jf = bpf_encode_jt_jf_offset(off, i);
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  		}
  	}
  }
  
  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 },
  ", 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("
  ");
  }
  
  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);
  }
d207cf4c1   Daniel Borkmann   bpf_exp: free dup... 
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  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]);
  	}
  }
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  static void bpf_destroy(void)
  {
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  	bpf_destroy_labels();
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  	free(labels_jt);
  	free(labels_jf);
  	free(labels_k);
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  	free(labels);
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  }
  
  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)
  {
b1d95ae5c   Ray Bellis   tools, bpf_asm: s... 
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  	fprintf(stderr, "error: %s at line %d
  ", str, yylineno);
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  	exit(1);
  }