src/bpf_hla_lexer.l

   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 %{
  10
  11 #include <stdio.h>
  12 #include <stdlib.h>
  13 #include <string.h>
  14 #include <ctype.h>
  15
  16 #include "bpf_hla_parser.tab.h"
  17 #include "bpf_symtab.h"
  18 #include "built_in.h"
  19
  20 void bpf_hla_lex_init(void);
  21
  22 struct res_keywords {
  23         const char *key;
  24         int token;
  25 };
  26
  27 #define KEYPAIR(k,t)    { .key = (k), .token = (t)}
  28 static const struct res_keywords keytab[] = {
  29         KEYPAIR("def",  K_DEF),
  30         KEYPAIR("pkt",  K_PKT),
  31         KEYPAIR("ret",  K_RET),
  32         KEYPAIR("if",   K_IF),
  33         KEYPAIR("elif", K_ELIF),
  34         KEYPAIR("else", K_ELSE),
  35 };
  36
  37 void bpf_hla_lex_init(void)
  38 {
  39         int i;
  40         for (i = 0; i < array_size(keytab); ++i)
  41                 bpf_symtab_insert(keytab[i].key, keytab[i].token);
  42 }
  43
  44 #define YY_USER_INIT    bpf_hla_lex_init();
  45
  46 extern void zzerror(const char *);
  47
  48 %}
  49
  50 %option align
  51 %option nounput
  52 %option noyywrap
  53 %option noreject
  54 %option 8bit
  55 %option caseless
  56 %option noinput
  57 %option nodefault
  58
  59 alpha           [A-Za-z]
  60 alphanum        [A-Za-z0-9]
  61
  62 digit           [0-9]
  63 digit_s         [1-9]
  64 digit_n         [0]
  65 bindigit        [0-1]
  66 bindigit_b      [b]
  67 hex             [a-fA-F0-9]
  68 hex_x           [x]
  69
  70 number_dec      {digit_n}|{digit_s}{digit}*
  71 number_oct      {digit_n}{digit}+
  72 number_hex      {digit_n}{hex_x}{hex}+
  73 number_bin      {digit_n}{bindigit_b}{bindigit}+
  74
  75 %%
  76
  77 {alpha}{alphanum}* {
  78                 zzlval.idx = bpf_symtab_find(zztext);
  79                 if (zzlval.idx < 0) {
  80                         zzlval.idx = bpf_symtab_insert(zztext, K_NAME);
  81                         return K_NAME;
  82                   } else {
  83                         return bpf_symtab_type(zzlval.idx);
  84                 }}
  85
  86 "("             { return '('; }
  87 ")"             { return ')'; }
  88 "{"             { return '{'; }
  89 "}"             { return '}'; }
  90 "="             { return '='; }
  91 ";"             { return ';'; }
  92 ","             { return ','; }
  93 "+"             { return '+'; }
  94 "-"             { return '-'; }
  95 "&"             { return '&'; }
  96 "|"             { return '|'; }
  97 "^"             { return '^'; }
  98 "!"             { return '!'; }
  99 "<"             { return '<'; }
 100 ">"             { return '>'; }
 101 "*"             { return '*'; }
 102 "/"             { return '/'; }
 103 "%"             { return '%'; }
 104
 105 {number_hex}    { zzlval.number = strtoul(zztext, NULL, 16);
 106                   return number_hex; }
 107
 108 {number_dec}    { zzlval.number = strtol(zztext, NULL, 10);
 109                   return number_dec; }
 110
 111 {number_oct}    { zzlval.number = strtol(zztext, NULL, 8);
 112                   return number_oct; }
 113
 114 {number_bin}    { zzlval.number = strtol(zztext + 2, NULL, 2);
 115                   return number_bin; }
 116
 117 "/*"([^\*]|\*[^/])*"*/" { /* NOP */ }
 118 ";"[^\n]*       {/* NOP */}
 119 "\n"            { zzlineno++; }
 120 [ \t]+          {/* NOP */ }
 121 .               { printf("Unknown character '%s'", zztext);
 122                   zzerror("lex Unknown character"); }
 123
 124 %%