772 lines
20 KiB
Plaintext
772 lines
20 KiB
Plaintext
/*
|
|
* 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;
|
|
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);
|
|
static void bpf_set_curr_label(char *label);
|
|
static void bpf_set_jmp_label(char *label, enum jmp_type type);
|
|
|
|
%}
|
|
|
|
%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
|
|
|
|
%token K_PKT_LEN K_PROTO K_TYPE K_NLATTR K_NLATTR_NEST K_MARK K_QUEUE K_HATYPE
|
|
%token K_RXHASH K_CPU K_IFIDX K_VLANT K_VLANP K_POFF K_RAND
|
|
|
|
%token ':' ',' '[' ']' '(' ')' 'x' 'a' '+' 'M' '*' '&' '#' '%'
|
|
|
|
%token number label
|
|
|
|
%type <label> label
|
|
%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); }
|
|
| OP_LDB K_PROTO {
|
|
bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_PROTOCOL); }
|
|
| OP_LDB K_TYPE {
|
|
bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_PKTTYPE); }
|
|
| OP_LDB K_IFIDX {
|
|
bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_IFINDEX); }
|
|
| OP_LDB K_NLATTR {
|
|
bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_NLATTR); }
|
|
| OP_LDB K_NLATTR_NEST {
|
|
bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_NLATTR_NEST); }
|
|
| OP_LDB K_MARK {
|
|
bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_MARK); }
|
|
| OP_LDB K_QUEUE {
|
|
bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_QUEUE); }
|
|
| OP_LDB K_HATYPE {
|
|
bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_HATYPE); }
|
|
| OP_LDB K_RXHASH {
|
|
bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_RXHASH); }
|
|
| OP_LDB K_CPU {
|
|
bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_CPU); }
|
|
| OP_LDB K_VLANT {
|
|
bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_VLAN_TAG); }
|
|
| OP_LDB K_VLANP {
|
|
bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_VLAN_TAG_PRESENT); }
|
|
| OP_LDB K_POFF {
|
|
bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_PAY_OFFSET); }
|
|
| OP_LDB K_RAND {
|
|
bpf_set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_RANDOM); }
|
|
;
|
|
|
|
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); }
|
|
| OP_LDH K_PROTO {
|
|
bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_PROTOCOL); }
|
|
| OP_LDH K_TYPE {
|
|
bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_PKTTYPE); }
|
|
| OP_LDH K_IFIDX {
|
|
bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_IFINDEX); }
|
|
| OP_LDH K_NLATTR {
|
|
bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_NLATTR); }
|
|
| OP_LDH K_NLATTR_NEST {
|
|
bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_NLATTR_NEST); }
|
|
| OP_LDH K_MARK {
|
|
bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_MARK); }
|
|
| OP_LDH K_QUEUE {
|
|
bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_QUEUE); }
|
|
| OP_LDH K_HATYPE {
|
|
bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_HATYPE); }
|
|
| OP_LDH K_RXHASH {
|
|
bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_RXHASH); }
|
|
| OP_LDH K_CPU {
|
|
bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_CPU); }
|
|
| OP_LDH K_VLANT {
|
|
bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_VLAN_TAG); }
|
|
| OP_LDH K_VLANP {
|
|
bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_VLAN_TAG_PRESENT); }
|
|
| OP_LDH K_POFF {
|
|
bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_PAY_OFFSET); }
|
|
| OP_LDH K_RAND {
|
|
bpf_set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_RANDOM); }
|
|
;
|
|
|
|
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); }
|
|
| OP_LD K_PROTO {
|
|
bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_PROTOCOL); }
|
|
| OP_LD K_TYPE {
|
|
bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_PKTTYPE); }
|
|
| OP_LD K_IFIDX {
|
|
bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_IFINDEX); }
|
|
| OP_LD K_NLATTR {
|
|
bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_NLATTR); }
|
|
| OP_LD K_NLATTR_NEST {
|
|
bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_NLATTR_NEST); }
|
|
| OP_LD K_MARK {
|
|
bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_MARK); }
|
|
| OP_LD K_QUEUE {
|
|
bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_QUEUE); }
|
|
| OP_LD K_HATYPE {
|
|
bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_HATYPE); }
|
|
| OP_LD K_RXHASH {
|
|
bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_RXHASH); }
|
|
| OP_LD K_CPU {
|
|
bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_CPU); }
|
|
| OP_LD K_VLANT {
|
|
bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_VLAN_TAG); }
|
|
| OP_LD K_VLANP {
|
|
bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_VLAN_TAG_PRESENT); }
|
|
| OP_LD K_POFF {
|
|
bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_PAY_OFFSET); }
|
|
| OP_LD K_RAND {
|
|
bpf_set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
|
|
SKF_AD_OFF + SKF_AD_RANDOM); }
|
|
| 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!\n");
|
|
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!\n");
|
|
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];
|
|
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 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 = (uint8_t) (off - i -1);
|
|
}
|
|
}
|
|
}
|
|
|
|
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 = (uint8_t) (off - i - 1);
|
|
}
|
|
}
|
|
}
|
|
|
|
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)
|
|
{
|
|
exit(1);
|
|
}
|