src/bpf_hla_parser.y

   1 /*
   2  * netsniff-ng - the packet sniffing beast
   3  * By Daniel Borkmann <daniel@netsniff-ng.org>
   4  * Copyright 2012 Daniel Borkmann <dborkma@tik.ee.ethz.ch>,
   5  * Swiss federal institute of technology (ETH Zurich)
   6  * Subject to the GPL, version 2.
   7  */
   8
   9 /* yaac-func-prefix: zz */
  10
  11 /*
  12     TODO:
  13         - intermediate representation
  14         - code optimization (symbolic reduction?)
  15         - linearization (jumps, etc)
  16         - bpf emitter
  17  */
  18
  19 %{
  20
  21 #include <stdio.h>
  22 #include <stdlib.h>
  23 #include <stdbool.h>
  24 #include <stdint.h>
  25 #include <errno.h>
  26
  27 #include "bpf.h"
  28 #include "bpf_hla_parser.tab.h"
  29 #include "bpf_symtab.h"
  30 #include "xmalloc.h"
  31 #include "xutils.h"
  32 #include "built_in.h"
  33 #include "die.h"
  34
  35 #define YYERROR_VERBOSE         0
  36 #define YYDEBUG                 0
  37 #define YYENABLE_NLS            1
  38 #define YYLTYPE_IS_TRIVIAL      1
  39 #define ENABLE_NLS              1
  40
  41 extern FILE *zzin;
  42 extern int zzlex(void);
  43 extern void zzerror(const char *);
  44 extern int zzlineno;
  45 extern char *zztext;
  46
  47 int compile_hla_filter(char *file, int verbose, int debug);
  48
  49 %}
  50
  51 %union {
  52         int idx;
  53         long int number;
  54 }
  55
  56 %token K_NAME K_DEF K_PKT K_RET K_IF K_ELIF K_ELSE
  57 %token K_MACRO_IPV4 K_MACRO_IPV6 K_MACRO_IP K_MACRO_UDP K_MACRO_TCP
  58
  59 %token number
  60
  61 %token '(' ')' '{' '}' '=' ';' '+' '-' '&' '|' '^' '!' '<' '>' '*' '/' '%' ','
  62
  63 %type <number> number
  64
  65 %%
  66
  67 program
  68         : { printf("Not supported yet!\n"); }
  69         ;
  70
  71 %%
  72
  73 static void stage_1_compile(void)
  74 {
  75         zzparse();
  76 }
  77
  78 int compile_hla_filter(char *file, int verbose, int debug)
  79 {
  80         int fd;
  81         fpos_t pos;
  82         char file_tmp[128];
  83
  84         /* XXX */
  85         verbose = verbose;
  86
  87         if (!strncmp("-", file, strlen("-")))
  88                 zzin = stdin;
  89         else
  90                 zzin = fopen(file, "r");
  91         if (!zzin)
  92                 panic("Cannot open file!\n");
  93         if (!debug) {
  94                 fd = dup(fileno(stdout));
  95
  96                 slprintf(file_tmp, sizeof(file_tmp), ".%s", file);
  97                 if (freopen(file_tmp, "w", stdout) == NULL)
  98                         panic("Cannot reopen file!\n");
  99         }
 100
 101         stage_1_compile();
 102
 103         if (!debug) {
 104                 fflush(stdout);
 105                 dup2(fd, fileno(stdout));
 106
 107                 close(fd);
 108                 clearerr(stdout);
 109                 fsetpos(stdout, &pos);
 110         }
 111
 112         fclose(zzin);
 113
 114         bpf_symtab_cleanup();
 115         if (debug)
 116                 die();
 117
 118         return 0;
 119 }
 120
 121 void zzerror(const char *err)
 122 {
 123         panic("Syntax error at line %d: %s! %s!\n",
 124               zzlineno, zztext, err);
 125 }