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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;
+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
+
+%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); }
+ ;
+
+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); }
+ ;
+
+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 '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);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-22 03:11:48 +0100