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-rw-r--r--bpf_parser.y673
1 files changed, 673 insertions, 0 deletions
diff --git a/bpf_parser.y b/bpf_parser.y
new file mode 100644
index 0000000..4c35e07
--- /dev/null
+++ b/bpf_parser.y
@@ -0,0 +1,673 @@
+/*
+ * netsniff-ng - the packet sniffing beast
+ * By Daniel Borkmann <daniel@netsniff-ng.org>
+ * Copyright 2011 Daniel Borkmann <dborkma@tik.ee.ethz.ch>,
+ * Swiss federal institute of technology (ETH Zurich)
+ * Subject to the GPL, version 2.
+ */
+
+/* yaac-func-prefix: yy */
+
+%{
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <signal.h>
+#include <stdint.h>
+#include <errno.h>
+
+#include "bpf.h"
+#include "xmalloc.h"
+#include "bpf_parser.tab.h"
+#include "built_in.h"
+#include "die.h"
+
+#define MAX_INSTRUCTIONS 4096
+
+int compile_filter(char *file, int verbose, int bypass, int decimal);
+
+static int curr_instr = 0;
+
+static struct sock_filter out[MAX_INSTRUCTIONS];
+
+static char *labels[MAX_INSTRUCTIONS];
+
+static char *labels_jt[MAX_INSTRUCTIONS];
+static char *labels_jf[MAX_INSTRUCTIONS];
+static char *labels_k[MAX_INSTRUCTIONS];
+
+#define YYERROR_VERBOSE 0
+#define YYDEBUG 0
+#define YYENABLE_NLS 1
+#define YYLTYPE_IS_TRIVIAL 1
+#define ENABLE_NLS 1
+
+extern FILE *yyin;
+extern int yylex(void);
+extern void yyerror(const char *);
+extern int yylineno;
+extern char *yytext;
+
+static inline void check_max_instr(void)
+{
+ if (curr_instr >= MAX_INSTRUCTIONS)
+ panic("Exceeded maximal number of instructions!\n");
+}
+
+static inline void set_curr_instr(uint16_t code, uint8_t jt, uint8_t jf, uint32_t k)
+{
+ check_max_instr();
+
+ out[curr_instr].code = code;
+ out[curr_instr].jt = jt;
+ out[curr_instr].jf = jf;
+ out[curr_instr].k = k;
+
+ curr_instr++;
+}
+
+static inline void set_curr_label(char *label)
+{
+ check_max_instr();
+
+ labels[curr_instr] = label;
+}
+
+#define JTL 1
+#define JFL 2
+#define JKL 3
+
+static inline void set_jmp_label(char *label, int which)
+{
+ check_max_instr();
+
+ switch (which) {
+ case JTL:
+ labels_jt[curr_instr] = label;
+ break;
+ case JFL:
+ labels_jf[curr_instr] = label;
+ break;
+ case JKL:
+ labels_k[curr_instr] = label;
+ break;
+ default:
+ bug();
+ }
+}
+
+static int find_intr_offset_or_panic(char *label_to_search)
+{
+ int i, max = curr_instr, ret = -ENOENT;
+
+ bug_on(!label_to_search);
+
+ for (i = 0; i < max; ++i) {
+ if (labels[i] != NULL) {
+ /* Both are \0-terminated! */
+ if (!strcmp(label_to_search, labels[i])) {
+ ret = i;
+ break;
+ }
+ }
+ }
+
+ if (ret == -ENOENT)
+ panic("No such label!\n");
+
+ return ret;
+}
+
+%}
+
+%union {
+ char *label;
+ long int 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
+
+%token ':' ',' '[' ']' '(' ')' 'x' 'a' '+' 'M' '*' '&' '#'
+
+%token number label
+
+%type <number> number
+%type <label> label
+
+%%
+
+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 ':' { set_curr_label($1); }
+ ;
+
+ldb
+ : OP_LDB '[' 'x' '+' number ']' {
+ set_curr_instr(BPF_LD | BPF_B | BPF_IND, 0, 0, $5); }
+ | OP_LDB '[' number ']' {
+ set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0, $3); }
+ | OP_LDB K_PROTO {
+ set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_PROTOCOL); }
+ | OP_LDB K_TYPE {
+ set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_PKTTYPE); }
+ | OP_LDB K_IFIDX {
+ set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_IFINDEX); }
+ | OP_LDB K_NLATTR {
+ set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_NLATTR); }
+ | OP_LDB K_NLATTR_NEST {
+ set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_NLATTR_NEST); }
+ | OP_LDB K_MARK {
+ set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_MARK); }
+ | OP_LDB K_QUEUE {
+ set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_QUEUE); }
+ | OP_LDB K_HATYPE {
+ set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_HATYPE); }
+ | OP_LDB K_RXHASH {
+ set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_RXHASH); }
+ | OP_LDB K_CPU {
+ set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_CPU); }
+ | OP_LDB K_VLANT {
+ set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_VLAN_TAG); }
+ | OP_LDB K_VLANP {
+ set_curr_instr(BPF_LD | BPF_B | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_VLAN_TAG_PRESENT); }
+ ;
+
+ldh
+ : OP_LDH '[' 'x' '+' number ']' {
+ set_curr_instr(BPF_LD | BPF_H | BPF_IND, 0, 0, $5); }
+ | OP_LDH '[' number ']' {
+ set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0, $3); }
+ | OP_LDH K_PROTO {
+ set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_PROTOCOL); }
+ | OP_LDH K_TYPE {
+ set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_PKTTYPE); }
+ | OP_LDH K_IFIDX {
+ set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_IFINDEX); }
+ | OP_LDH K_NLATTR {
+ set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_NLATTR); }
+ | OP_LDH K_NLATTR_NEST {
+ set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_NLATTR_NEST); }
+ | OP_LDH K_MARK {
+ set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_MARK); }
+ | OP_LDH K_QUEUE {
+ set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_QUEUE); }
+ | OP_LDH K_HATYPE {
+ set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_HATYPE); }
+ | OP_LDH K_RXHASH {
+ set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_RXHASH); }
+ | OP_LDH K_CPU {
+ set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_CPU); }
+ | OP_LDH K_VLANT {
+ set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_VLAN_TAG); }
+ | OP_LDH K_VLANP {
+ set_curr_instr(BPF_LD | BPF_H | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_VLAN_TAG_PRESENT); }
+ ;
+
+ldi
+ : OP_LDI number {
+ set_curr_instr(BPF_LD | BPF_IMM, 0, 0, $2); }
+ ;
+
+ld
+ : OP_LD '#' number {
+ set_curr_instr(BPF_LD | BPF_IMM, 0, 0, $3); }
+ | OP_LD K_PKT_LEN {
+ set_curr_instr(BPF_LD | BPF_W | BPF_LEN, 0, 0, 0); }
+ | OP_LD K_PROTO {
+ set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_PROTOCOL); }
+ | OP_LD K_TYPE {
+ set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_PKTTYPE); }
+ | OP_LD K_IFIDX {
+ set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_IFINDEX); }
+ | OP_LD K_NLATTR {
+ set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_NLATTR); }
+ | OP_LD K_NLATTR_NEST {
+ set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_NLATTR_NEST); }
+ | OP_LD K_MARK {
+ set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_MARK); }
+ | OP_LD K_QUEUE {
+ set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_QUEUE); }
+ | OP_LD K_HATYPE {
+ set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_HATYPE); }
+ | OP_LD K_RXHASH {
+ set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_RXHASH); }
+ | OP_LD K_CPU {
+ set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_CPU); }
+ | OP_LD K_VLANT {
+ set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_VLAN_TAG); }
+ | OP_LD K_VLANP {
+ set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0,
+ SKF_AD_OFF + SKF_AD_VLAN_TAG_PRESENT); }
+ | OP_LD 'M' '[' number ']' {
+ set_curr_instr(BPF_LD | BPF_MEM, 0, 0, $4); }
+ | OP_LD '[' 'x' '+' number ']' {
+ set_curr_instr(BPF_LD | BPF_W | BPF_IND, 0, 0, $5); }
+ | OP_LD '[' number ']' {
+ set_curr_instr(BPF_LD | BPF_W | BPF_ABS, 0, 0, $3); }
+ ;
+
+ldxi
+ : OP_LDXI number {
+ set_curr_instr(BPF_LDX | BPF_IMM, 0, 0, $2); }
+ ;
+
+ldx
+ : OP_LDX '#' number {
+ set_curr_instr(BPF_LDX | BPF_IMM, 0, 0, $3); }
+ | OP_LDX 'M' '[' number ']' {
+ set_curr_instr(BPF_LDX | BPF_MEM, 0, 0, $4); }
+ | OP_LDXB number '*' '(' '[' number ']' '&' number ')' {
+ if ($2 != 4 || $9 != 0xf) {
+ panic("ldxb offset not supported!\n");
+ } else {
+ set_curr_instr(BPF_LDX | BPF_MSH | BPF_B, 0, 0, $6); } }
+ | OP_LDX number '*' '(' '[' number ']' '&' number ')' {
+ if ($2 != 4 || $9 != 0xf) {
+ panic("ldxb offset not supported!\n");
+ } else {
+ set_curr_instr(BPF_LDX | BPF_MSH | BPF_B, 0, 0, $6); } }
+ ;
+
+st
+ : OP_ST 'M' '[' number ']' {
+ set_curr_instr(BPF_ST, 0, 0, $4); }
+ ;
+
+stx
+ : OP_STX 'M' '[' number ']' {
+ set_curr_instr(BPF_STX, 0, 0, $4); }
+ ;
+
+jmp
+ : OP_JMP label {
+ set_jmp_label($2, JKL);
+ set_curr_instr(BPF_JMP | BPF_JA, 0, 0, 0); }
+ ;
+
+jeq
+ : OP_JEQ '#' number ',' label ',' label {
+ set_jmp_label($5, JTL);
+ set_jmp_label($7, JFL);
+ set_curr_instr(BPF_JMP | BPF_JEQ | BPF_K, 0, 0, $3); }
+ | OP_JEQ 'x' ',' label ',' label {
+ set_jmp_label($4, JTL);
+ set_jmp_label($6, JFL);
+ set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); }
+ | OP_JEQ '#' number ',' label {
+ set_jmp_label($5, JTL);
+ set_curr_instr(BPF_JMP | BPF_JEQ | BPF_K, 0, 0, $3); }
+ | OP_JEQ 'x' ',' label {
+ set_jmp_label($4, JTL);
+ set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); }
+ ;
+
+jneq
+ : OP_JNEQ '#' number ',' label {
+ set_jmp_label($5, JFL);
+ set_curr_instr(BPF_JMP | BPF_JEQ | BPF_K, 0, 0, $3); }
+ | OP_JNEQ 'x' ',' label {
+ set_jmp_label($4, JFL);
+ set_curr_instr(BPF_JMP | BPF_JEQ | BPF_X, 0, 0, 0); }
+ ;
+
+jlt
+ : OP_JLT '#' number ',' label {
+ set_jmp_label($5, JFL);
+ set_curr_instr(BPF_JMP | BPF_JGE | BPF_K, 0, 0, $3); }
+ | OP_JLT 'x' ',' label {
+ set_jmp_label($4, JFL);
+ set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); }
+ ;
+
+jle
+ : OP_JLE '#' number ',' label {
+ set_jmp_label($5, JFL);
+ set_curr_instr(BPF_JMP | BPF_JGT | BPF_K, 0, 0, $3); }
+ | OP_JLE 'x' ',' label {
+ set_jmp_label($4, JFL);
+ set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); }
+ ;
+
+jgt
+ : OP_JGT '#' number ',' label ',' label {
+ set_jmp_label($5, JTL);
+ set_jmp_label($7, JFL);
+ set_curr_instr(BPF_JMP | BPF_JGT | BPF_K, 0, 0, $3); }
+ | OP_JGT 'x' ',' label ',' label {
+ set_jmp_label($4, JTL);
+ set_jmp_label($6, JFL);
+ set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); }
+ | OP_JGT '#' number ',' label {
+ set_jmp_label($5, JTL);
+ set_curr_instr(BPF_JMP | BPF_JGT | BPF_K, 0, 0, $3); }
+ | OP_JGT 'x' ',' label {
+ set_jmp_label($4, JTL);
+ set_curr_instr(BPF_JMP | BPF_JGT | BPF_X, 0, 0, 0); }
+ ;
+
+jge
+ : OP_JGE '#' number ',' label ',' label {
+ set_jmp_label($5, JTL);
+ set_jmp_label($7, JFL);
+ set_curr_instr(BPF_JMP | BPF_JGE | BPF_K, 0, 0, $3); }
+ | OP_JGE 'x' ',' label ',' label {
+ set_jmp_label($4, JTL);
+ set_jmp_label($6, JFL);
+ set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); }
+ | OP_JGE '#' number ',' label {
+ set_jmp_label($5, JTL);
+ set_curr_instr(BPF_JMP | BPF_JGE | BPF_K, 0, 0, $3); }
+ | OP_JGE 'x' ',' label {
+ set_jmp_label($4, JTL);
+ set_curr_instr(BPF_JMP | BPF_JGE | BPF_X, 0, 0, 0); }
+ ;
+
+jset
+ : OP_JSET '#' number ',' label ',' label {
+ set_jmp_label($5, JTL);
+ set_jmp_label($7, JFL);
+ set_curr_instr(BPF_JMP | BPF_JSET | BPF_K, 0, 0, $3); }
+ | OP_JSET 'x' ',' label ',' label {
+ set_jmp_label($4, JTL);
+ set_jmp_label($6, JFL);
+ set_curr_instr(BPF_JMP | BPF_JSET | BPF_X, 0, 0, 0); }
+ | OP_JSET '#' number ',' label {
+ set_jmp_label($5, JTL);
+ set_curr_instr(BPF_JMP | BPF_JSET | BPF_K, 0, 0, $3); }
+ | OP_JSET 'x' ',' label {
+ set_jmp_label($4, JTL);
+ set_curr_instr(BPF_JMP | BPF_JSET | BPF_X, 0, 0, 0); }
+ ;
+
+add
+ : OP_ADD '#' number {
+ set_curr_instr(BPF_ALU | BPF_ADD | BPF_K, 0, 0, $3); }
+ | OP_ADD 'x' {
+ set_curr_instr(BPF_ALU | BPF_ADD | BPF_X, 0, 0, 0); }
+ ;
+
+sub
+ : OP_SUB '#' number {
+ set_curr_instr(BPF_ALU | BPF_SUB | BPF_K, 0, 0, $3); }
+ | OP_SUB 'x' {
+ set_curr_instr(BPF_ALU | BPF_SUB | BPF_X, 0, 0, 0); }
+ ;
+
+mul
+ : OP_MUL '#' number {
+ set_curr_instr(BPF_ALU | BPF_MUL | BPF_K, 0, 0, $3); }
+ | OP_MUL 'x' {
+ set_curr_instr(BPF_ALU | BPF_MUL | BPF_X, 0, 0, 0); }
+ ;
+
+div
+ : OP_DIV '#' number {
+ set_curr_instr(BPF_ALU | BPF_DIV | BPF_K, 0, 0, $3); }
+ | OP_DIV 'x' {
+ set_curr_instr(BPF_ALU | BPF_DIV | BPF_X, 0, 0, 0); }
+ ;
+
+mod
+ : OP_MOD '#' number {
+ set_curr_instr(BPF_ALU | BPF_MOD | BPF_K, 0, 0, $3); }
+ | OP_MOD 'x' {
+ set_curr_instr(BPF_ALU | BPF_MOD | BPF_X, 0, 0, 0); }
+ ;
+
+neg
+ : OP_NEG {
+ set_curr_instr(BPF_ALU | BPF_NEG, 0, 0, 0); }
+ ;
+
+and
+ : OP_AND '#' number {
+ set_curr_instr(BPF_ALU | BPF_AND | BPF_K, 0, 0, $3); }
+ | OP_AND 'x' {
+ set_curr_instr(BPF_ALU | BPF_AND | BPF_X, 0, 0, 0); }
+ ;
+
+or
+ : OP_OR '#' number {
+ set_curr_instr(BPF_ALU | BPF_OR | BPF_K, 0, 0, $3); }
+ | OP_OR 'x' {
+ set_curr_instr(BPF_ALU | BPF_OR | BPF_X, 0, 0, 0); }
+ ;
+
+xor
+ : OP_XOR '#' number {
+ set_curr_instr(BPF_ALU | BPF_XOR | BPF_K, 0, 0, $3); }
+ | OP_XOR 'x' {
+ set_curr_instr(BPF_ALU | BPF_XOR | BPF_X, 0, 0, 0); }
+ ;
+
+lsh
+ : OP_LSH '#' number {
+ set_curr_instr(BPF_ALU | BPF_LSH | BPF_K, 0, 0, $3); }
+ | OP_LSH 'x' {
+ set_curr_instr(BPF_ALU | BPF_LSH | BPF_X, 0, 0, 0); }
+ ;
+
+rsh
+ : OP_RSH '#' number {
+ set_curr_instr(BPF_ALU | BPF_RSH | BPF_K, 0, 0, $3); }
+ | OP_RSH 'x' {
+ set_curr_instr(BPF_ALU | BPF_RSH | BPF_X, 0, 0, 0); }
+ ;
+
+ret
+ : OP_RET 'a' {
+ set_curr_instr(BPF_RET | BPF_A, 0, 0, 0); }
+ | OP_RET 'x' {
+ set_curr_instr(BPF_RET | BPF_X, 0, 0, 0); }
+ | OP_RET '#' number {
+ set_curr_instr(BPF_RET | BPF_K, 0, 0, $3); }
+ ;
+
+tax
+ : OP_TAX {
+ set_curr_instr(BPF_MISC | BPF_TAX, 0, 0, 0); }
+ ;
+
+txa
+ : OP_TXA {
+ set_curr_instr(BPF_MISC | BPF_TXA, 0, 0, 0); }
+ ;
+
+%%
+
+static void stage_1_inline(void)
+{
+ yyparse();
+}
+
+static void stage_2_label_reduce(void)
+{
+ int i, max = curr_instr, off;
+
+ /* 1. reduce k jumps */
+ for (i = 0; i < max; ++i) {
+ if (labels_k[i] != NULL) {
+ off = find_intr_offset_or_panic(labels_k[i]);
+ out[i].k = (uint32_t) (off - i - 1);
+ }
+ }
+
+ /* 1. reduce jt jumps */
+ for (i = 0; i < max; ++i) {
+ if (labels_jt[i] != NULL) {
+ off = find_intr_offset_or_panic(labels_jt[i]);
+ out[i].jt = (uint8_t) (off - i -1);
+ }
+ }
+
+ /* 1. reduce jf jumps */
+ for (i = 0; i < max; ++i) {
+ if (labels_jf[i] != NULL) {
+ off = find_intr_offset_or_panic(labels_jf[i]);
+ out[i].jf = (uint8_t) (off - i - 1);
+ }
+ }
+}
+
+int compile_filter(char *file, int verbose, int bypass, int decimal)
+{
+ int i;
+ struct sock_fprog res;
+
+ if (!strncmp("-", file, strlen("-")))
+ yyin = stdin;
+ else
+ yyin = fopen(file, "r");
+ if (!yyin)
+ panic("Cannot open file!\n");
+
+ memset(out, 0, sizeof(out));
+ memset(labels, 0, sizeof(labels));
+ memset(labels_jf, 0, sizeof(labels_jf));
+ memset(labels_jt, 0, sizeof(labels_jt));
+ memset(labels_k, 0, sizeof(labels_k));
+
+ stage_1_inline();
+ stage_2_label_reduce();
+
+ res.filter = out;
+ res.len = curr_instr;
+
+ if (verbose) {
+ printf("Generated program:\n");
+ bpf_dump_all(&res);
+ }
+
+ if (!bypass) {
+ if (verbose) {
+ printf("Validating: ");
+ fflush(stdout);
+ }
+
+ if (__bpf_validate(&res) == 0) {
+ if (verbose)
+ printf("Semantic error! BPF validation failed!\n");
+ else
+ panic("Semantic error! BPF validation failed! "
+ "Try -V for debugging output!\n");
+ } else if (verbose) {
+ printf("is runnable!\n");
+ }
+ }
+
+ if (verbose)
+ printf("Result:\n");
+ for (i = 0; i < res.len; ++i) {
+ if (decimal) {
+ printf("%u %u %u %u\n",
+ res.filter[i].code, res.filter[i].jt,
+ res.filter[i].jf, res.filter[i].k);
+ } else {
+ printf("{ 0x%x, %u, %u, 0x%08x },\n",
+ res.filter[i].code, res.filter[i].jt,
+ res.filter[i].jf, res.filter[i].k);
+ }
+
+ free(labels[i]);
+ free(labels_jt[i]);
+ free(labels_jf[i]);
+ free(labels_k[i]);
+ }
+
+ fclose(yyin);
+ return 0;
+}
+
+void yyerror(const char *err)
+{
+ panic("Syntax error at line %d: %s! %s!\n",
+ yylineno, yytext, err);
+}