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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 <stdbool.h>
#include <arpa/inet.h>
#include "trafgen_parser.tab.h"
#include "xmalloc.h"
#include "built_in.h"
#include "str.h"
extern void yyerror(const char *);
static char *try_convert_shellcode(char *sstr)
{
bool found_any = false;
char *bstr, *ostr = sstr, *hay, *orig = sstr;
size_t j = 0, blen, slen = strlen(sstr), tot = 0;
const char *needle = "\\x";
sstr++;
slen -= 2;
if (slen % 4 != 0)
return orig;
blen = slen / 4;
hay = sstr;
while ((hay = strstr(hay, needle)) != NULL ) {
hay += strlen(needle) + 2;
found_any = true;
tot++;
}
if (blen != tot || !found_any)
return orig;
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])
a_hex ([a-fA-F0-9]+)
mac ({a_hex}:{a_hex}:{a_hex}:{a_hex}:{a_hex}:{a_hex})
ip4_addr ([0-9]+\.[0-9]+\.[0-9]+\.[0-9]+)
/* We're very permissive about IPv6 addresses the grammar accepts, as
* they can come in various different formats. In any case,
* inet_pton(AF_INET6, ...) will reject the invalid ones later on. */
ip6_addr (({a_hex}?:)?({a_hex}?:)?({a_hex}?:)?({a_hex}?:)?({a_hex}?:)?({a_hex}?:)?({a_hex}?:)?({a_hex})?)
%%
"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; }
"csumudp6" { return K_CSUMUDP6; }
"csumtcp6" { return K_CSUMTCP6; }
"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; }
"prot"[o]? { return K_PROT; }
"tc"|"tclass" { return K_TC; }
/* Ethernet */
"daddr"|"da" { return K_DADDR; }
"saddr"|"sa" { return K_SADDR; }
"etype" { return K_ETYPE; }
"type" { return K_TYPE; }
/* VLAN (802.1Q & 802.1ad) */
"tpid" { return K_TPID; }
"tci" { return K_TCI; }
"pcp" { return K_PCP; }
"dei"|"cfi" { return K_DEI; }
"1ad" { return K_1AD; }
"1q" { return K_1Q; }
/* MPLS (Multi Protocol Label Switching) */
"lbl"|"label" { return K_LABEL; }
"last" { return K_LAST; }
"exp" { return K_EXP; }
/* ARP */
"sha"|"smac" { return K_SHA; }
"spa"|"sip" { return K_SPA; }
"tha"|"tmac" { return K_THA; }
"tpa"|"tip" { return K_TPA; }
"req"|"request" { return K_REQUEST; }
"reply" { return K_REPLY; }
"op"|"oper" { return K_OPER; }
"htype" { return K_HTYPE; }
"ptype" { return K_PTYPE; }
/* IPv4 */
"ihl" { return K_IHL; }
"ver"|"version" { return K_VER; }
"ttl" { return K_TTL; }
"dscp" { return K_DSCP; }
"ecn" { return K_ECN; }
"tos" { return K_TOS; }
"len"|"length" { return K_LEN; }
"id" { return K_ID; }
"flags" { return K_FLAGS; }
"frag" { return K_FRAG; }
"csum" { return K_CSUM; }
"df" { return K_DF; }
"mf" { return K_MF; }
/* IPv6 */
"fl"|"flow" { return K_FLOW; }
"nh"|"nexthdr" { return K_NEXT_HDR; }
"hl"|"hoplimit" { return K_HOP_LIMIT; }
/* ICMPv6 */
"mtype" { return K_MTYPE; }
"code" { return K_CODE; }
"echorequest" { return K_ECHO_REQUEST; }
"echoreply" { return K_ECHO_REPLY; }
/* UDP */
"sp"|"sport" { return K_SPORT; }
"dp"|"dport" { return K_DPORT; }
/* TCP */
"seq" { return K_SEQ; }
"ackseq"|"aseq" { return K_ACK_SEQ; }
"doff"|hlen { return K_DOFF; }
"cwr" { return K_CWR; }
"ece"|"ecn" { return K_ECE; }
"urg" { return K_URG; }
"ack" { return K_ACK; }
"psh" { return K_PSH; }
"rst" { return K_RST; }
"syn" { return K_SYN; }
"fin" { return K_FIN; }
"win"|"window" { return K_WINDOW; }
"urgptr" { return K_URG_PTR; }
"eth" { return K_ETH; }
"vlan" { return K_VLAN; }
"mpls" { return K_MPLS; }
"arp" { return K_ARP; }
"ip4"|"ipv4" { return K_IP4; }
"ip6"|"ipv6" { return K_IP6; }
"icmp6"|"icmpv6" { return K_ICMP6; }
"udp" { return K_UDP; }
"tcp" { return K_TCP; }
[ ]*"-"[ ]* { return '-'; }
[ ]*"+"[ ]* { 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 + (yytext[0] == 'x' ? 1 : 0),
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 + (yytext[0] == 'b' ? 1 : 2),
NULL, 2);
return number; }
{number_ascii} { yylval.number = (uint8_t) (*yytext);
return number; }
{mac} { if (str2mac(yytext, yylval.bytes, 256))
panic("Failed to parse MAC address %s\n", yytext);
return mac; }
{ip4_addr} { if (inet_pton(AF_INET, yytext, &yylval.ip4_addr) != 1)
panic("Failed to parse IPv4 address %s\n", yytext);
return ip4_addr; };
{ip6_addr} { if (inet_pton(AF_INET6, yytext, &yylval.ip6_addr) != 1)
panic("Failed to parse IPv6 address %s\n", yytext);
return ip6_addr; };
"'\\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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