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/*
* netsniff-ng - the packet sniffing beast
* By Daniel Borkmann <daniel@netsniff-ng.org>
* Copyright 2012 Daniel Borkmann <dborkma@tik.ee.ethz.ch>,
* Swiss federal institute of technology (ETH Zurich)
* Subject to the GPL, version 2.
*/
/* lex-func-prefix: yy */
%{
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include "trafgen_parser.tab.h"
#include "xmalloc.h"
extern void yyerror(const char *);
static char *try_convert_shellcode(char *sstr)
{
int j = 0;
char *bstr, *ostr = sstr, *hay;
size_t blen, slen = strlen(sstr), tot = 0;
const char *needle = "\\x";
sstr++;
slen -= 2;
if (slen % 4 != 0)
return sstr;
blen = slen / 4;
hay = sstr;
while ((hay = strstr(hay, needle)) != NULL ) {
hay += strlen(needle) + 2;
tot++;
}
if (blen != tot) {
printf("Warning: mixed shellcode with strings, "
"using strings!\n");
return sstr;
}
blen += 2;
bstr = xzmalloc(blen);
bstr[j++] = '\"';
while (j < blen - 1)
bstr[j++] = (uint8_t) strtoul(sstr + 2, &sstr, 16);
bstr[j++] = '\"';
xfree(ostr);
return bstr;
}
%}
%option align
%option nounput
%option noyywrap
%option noreject
%option 8bit
%option caseless
%option noinput
%option nodefault
number_oct ([0][0-9]+)
number_hex ([0][x][a-fA-F0-9]+)
number_bin ([0][b][0-1]+)
number_dec (([0])|([1-9][0-9]*))
number_ascii ([a-zA-Z])
%%
"cpu" { return K_CPU; }
"fill" { return K_FILL; }
"rnd" { return K_RND; }
"csum16" { return K_CSUMIP; }
"csumip" { return K_CSUMIP; }
"csumip4" { return K_CSUMIP; }
"csumicmp" { return K_CSUMIP; }
"csumicmp4" { return K_CSUMIP; }
"csumudp" { return K_CSUMUDP; }
"csumtcp" { return K_CSUMTCP; }
"drnd" { return K_DRND; }
"dinc" { return K_DINC; }
"ddec" { return K_DDEC; }
"seqinc" { return K_SEQINC; }
"seqdec" { return K_SEQDEC; }
"const8"|"c8" { return K_CONST8; }
"const16"|"c16" { return K_CONST16; }
"const32"|"c32" { return K_CONST32; }
"const64"|"c64" { return K_CONST64; }
[ ]*"-"[ ]* { return '-'; }
[ ]*"+"[ ]* { return '+'; }
[ ]*"*"[ ]* { return '*'; }
[ ]*"/"[ ]* { return '/'; }
[ ]*"%"[ ]* { return '%'; }
[ ]*"&"[ ]* { return '&'; }
[ ]*"|"[ ]* { return '|'; }
[ ]*"<"[ ]* { return '<'; }
[ ]*">"[ ]* { return '>'; }
[ ]*"^"[ ]* { return '^'; }
"{" { return '{'; }
"}" { return '}'; }
"(" { return '('; }
")" { return ')'; }
"[" { return '['; }
"]" { return ']'; }
"," { return ','; }
":" { return ':'; }
"\n" { yylineno++; }
"\""[^\"]+"\"" { yylval.str = try_convert_shellcode(xstrdup(yytext));
return string; }
([ \t\n]+)? { return K_WHITE; }
"/*"([^\*]|\*[^/])*"*/" { return K_COMMENT; }
"#"[^\n]* { return K_COMMENT; }
{number_hex} { yylval.number = strtoul(yytext, NULL, 16);
return number; }
{number_dec} { yylval.number = strtol(yytext, NULL, 10);
return number; }
{number_oct} { yylval.number = strtol(yytext + 1, NULL, 8);
return number; }
{number_bin} { yylval.number = strtol(yytext + 2, NULL, 2);
return number; }
{number_ascii} { yylval.number = (uint8_t) (*yytext);
return number; }
"'\\x"[a-fA-F0-9]{2}"'" { yylval.number = strtol(yytext + 3, NULL, 16);
return number; }
"'"."'" { yylval.number = (uint8_t) (*(yytext + 1));
return number; }
";"[^\n]* {/* NOP */}
. { printf("Unknown character '%s'", yytext);
yyerror("lex Unknown character"); }
%%
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