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/* Copyright (C) 2000-2006 Boris Wesslowski */
/* $Id: ipfilter.l,v 1.23 2006/03/08 19:36:02 bw Exp $ */
%option prefix="ipf"
%option outfile="ipfilter.c"
%option noyywrap
%{
#define YY_NO_UNPUT
#include <unistd.h>
#include <string.h>
#include <ctype.h>
#include <netdb.h>
#include "main.h"
#include "utils.h"
extern struct options opt;
void ipf_parse_date(char *input);
void ipf_parse_data(char *input, unsigned char mode);
void ipf_parse_ips(char *input, unsigned char mode);
void ipf_parse_proto(char *input);
void ipf_parse_flags(char *input);
%}
MONTH "Jan"|"Feb"|"Mar"|"Apr"|"May"|"Jun"|"Jul"|"Aug"|"Sep"|"Oct"|"Nov"|"Dec"
STRING [a-zA-Z0-9.,_-]*
LOGHOST [0-9.a-zA-Z()_:-]*
DIGIT [0-9]
NUMBER {DIGIT}+
HEXDIGIT [0-9a-f]
OCTET {DIGIT}{1,3}
PORT {DIGIT}{1,5}
IPFILTER "ipmon["{NUMBER}"]:"
FLAGS "-"[SAFRPU]+
PROTO [0-9a-z-]+
TARGET [SpPbBnL]
%%
{MONTH}[ ]{1,2}{DIGIT}{1,2}[ ]{DIGIT}{2}:{DIGIT}{2}:{DIGIT}{2}[ ]{LOGHOST} ipf_parse_date(ipftext);
{IPFILTER} /* ignore */
"[ID "{NUMBER}" "{STRING}"]" /* ignore */
{DIGIT}{2}":"{DIGIT}{2}":"{DIGIT}{2}"."{DIGIT}{6} /* ignore */
{STRING}[ ]"@"{NUMBER}":"{NUMBER}[ ]{TARGET} ipf_parse_data(ipftext, IPF_OPT_NONE);
{NUMBER}"x"[ ]+{STRING}[ ]"@"{NUMBER}":"{NUMBER}[ ]{TARGET} ipf_parse_data(ipftext, IPF_OPT_COUNT);
{OCTET}"."{OCTET}"."{OCTET}"."{OCTET} ipf_parse_ips(ipftext, IPF_OPT_SRC);
" -> "{OCTET}"."{OCTET}"."{OCTET}"."{OCTET} ipf_parse_ips(ipftext+4, IPF_OPT_DST);
{OCTET}"."{OCTET}"."{OCTET}"."{OCTET}","{PORT} ipf_parse_ips(ipftext, IPF_OPT_SRC|IPF_OPT_PORT);
" -> "{OCTET}"."{OCTET}"."{OCTET}"."{OCTET}","{PORT} ipf_parse_ips(ipftext+4, IPF_OPT_DST|IPF_OPT_PORT);
{STRING}"["{OCTET}"."{OCTET}"."{OCTET}"."{OCTET}"]" ipf_parse_ips(ipftext, IPF_OPT_SRC|IPF_OPT_RES);
" -> "{STRING}"["{OCTET}"."{OCTET}"."{OCTET}"."{OCTET}"]" ipf_parse_ips(ipftext+4, IPF_OPT_DST|IPF_OPT_RES);
{STRING}"["{OCTET}"."{OCTET}"."{OCTET}"."{OCTET}"],"{PORT} ipf_parse_ips(ipftext, IPF_OPT_SRC|IPF_OPT_RES|IPF_OPT_PORT);
" -> "{STRING}"["{OCTET}"."{OCTET}"."{OCTET}"."{OCTET}"],"{PORT} ipf_parse_ips(ipftext+4, IPF_OPT_DST|IPF_OPT_RES|IPF_OPT_PORT);
{OCTET}"."{OCTET}"."{OCTET}"."{OCTET}","{STRING} ipf_parse_ips(ipftext, IPF_OPT_SRC|IPF_OPT_RPORT);
" -> "{OCTET}"."{OCTET}"."{OCTET}"."{OCTET}","{STRING} ipf_parse_ips(ipftext+4, IPF_OPT_DST|IPF_OPT_RPORT);
{STRING}"["{OCTET}"."{OCTET}"."{OCTET}"."{OCTET}"],"{STRING} ipf_parse_ips(ipftext, IPF_OPT_SRC|IPF_OPT_RES|IPF_OPT_RPORT);
" -> "{STRING}"["{OCTET}"."{OCTET}"."{OCTET}"."{OCTET}"],"{STRING} ipf_parse_ips(ipftext+4, IPF_OPT_DST|IPF_OPT_RES|IPF_OPT_RPORT);
"PR "{PROTO} ipf_parse_proto(ipftext+3);
"len "{NUMBER}[ ][(]?{NUMBER}[)]? opt.line->datalen = atoi(ipftext+4);
"frag "{NUMBER}"@"{NUMBER} /* ignore */
"icmp "{DIGIT}{1,2}"/"{DIGIT}{1,2} sscanf(ipftext, "icmp %d/%d", &opt.line->sport, &opt.line->dport); opt.parser=opt.parser|IPF_SRC_PORT|IPF_DST_PORT;
"icmp echo/0" opt.line->sport = 8; opt.line->dport = 0; opt.parser=opt.parser|IPF_SRC_PORT|IPF_DST_PORT;
"icmp echoreply/0" opt.line->sport = 0; opt.line->dport = 0; opt.parser=opt.parser|IPF_SRC_PORT|IPF_DST_PORT;
"icmp sourcequench/0" opt.line->sport = 4; opt.line->dport = 0; opt.parser=opt.parser|IPF_SRC_PORT|IPF_DST_PORT;
"icmp unreach/host" opt.line->sport = 3; opt.line->dport = 1; opt.parser=opt.parser|IPF_SRC_PORT|IPF_DST_PORT;
"icmp unreach/port" opt.line->sport = 3; opt.line->dport = 3; opt.parser=opt.parser|IPF_SRC_PORT|IPF_DST_PORT;
"icmp unreach/admin_prohibit" opt.line->sport = 3; opt.line->dport = 10; opt.parser=opt.parser|IPF_SRC_PORT|IPF_DST_PORT;
"icmp timxceed/intrans" opt.line->sport = 11; opt.line->dport = 1; opt.parser=opt.parser|IPF_SRC_PORT|IPF_DST_PORT;
"for "{OCTET}"."{OCTET}"."{OCTET}"."{OCTET}","{PORT}" - "{OCTET}"."{OCTET}"."{OCTET}"."{OCTET}","{PORT}" PR "{PROTO}" len "{NUMBER}[ ]{NUMBER} /* ignore */
"for "{OCTET}"."{OCTET}"."{OCTET}"."{OCTET}","{STRING}" - "{STRING}"["{OCTET}"."{OCTET}"."{OCTET}"."{OCTET}"],"{STRING}" PR "{PROTO}" len "{NUMBER}[ ]{NUMBER} /* ignore */
"for "{STRING}"["{OCTET}"."{OCTET}"."{OCTET}"."{OCTET}"],"{PORT}" - "{OCTET}"."{OCTET}"."{OCTET}"."{OCTET}","{PORT}" PR "{PROTO}" len "{NUMBER}[ ]{NUMBER} /* ignore */
"for "{STRING}"["{OCTET}"."{OCTET}"."{OCTET}"."{OCTET}"],"{PORT}" - "{OCTET}"."{OCTET}"."{OCTET}"."{OCTET}","{STRING}" PR "{PROTO}" len "{NUMBER}[ ]{NUMBER} /* ignore */
"for "{STRING}"["{OCTET}"."{OCTET}"."{OCTET}"."{OCTET}"] - "{STRING}"["{OCTET}"."{OCTET}"."{OCTET}"."{OCTET}"] PR "{PROTO}" len "{NUMBER}" ("{NUMBER}")" /* ignore */
"for "{STRING}"["{OCTET}"."{OCTET}"."{OCTET}"."{OCTET}"],"{PORT}" - "{STRING}"["{OCTET}"."{OCTET}"."{OCTET}"."{OCTET}"],"{PORT}" PR "{PROTO}" len "{NUMBER}[ ]{NUMBER} /* ignore */
"for "{STRING}"["{OCTET}"."{OCTET}"."{OCTET}"."{OCTET}"],"{PORT}" - "{STRING}"["{OCTET}"."{OCTET}"."{OCTET}"."{OCTET}"],"{STRING}" PR "{PROTO}" len "{NUMBER}[ ]{NUMBER} /* ignore */
{FLAGS} ipf_parse_flags(ipftext+1);
"K-S" /* ignore */
"K-F" /* ignore */
"IN" /* ignore */
"OUT" /* ignore */
"mbcast" /* ignore */
{NUMBER}[ ]{NUMBER}[ ]{NUMBER}" IN" /* ignore */
({HEXDIGIT}{HEXDIGIT}[ ]?)+[ ]+[ -~]+ opt.parser=opt.parser|IPF_NO_HIT;
[ \t]+ /* ignore whitespace */
[\n] /* ignore */
{STRING} if(opt.verbose) fprintf(stderr, "Unrecognized token: %s\n", ipftext);
. if(opt.verbose) fprintf(stderr, "Unrecognized character: %s\n", ipftext);
%%
void ipf_parse_date(char *input)
{
int retval, day, hour, minute, second;
char smonth[3];
retval = sscanf(input, "%3s %2d %2d:%2d:%2d %32s",
smonth, &day, &hour, &minute, &second,
opt.line->hostname);
if (retval != 6) return;
build_time(smonth, day, hour, minute, second);
opt.parser=opt.parser|IPF_DATE;
}
void ipf_parse_data(char *input, unsigned char mode)
{
int retval;
if (mode == IPF_OPT_COUNT) {
retval = sscanf(input, "%dx %" SHORTLEN_S "s @%" SHORTLEN_S "s %" SHORTLEN_S "s",
&opt.line->count,
opt.line->interface,
opt.line->chainlabel,
opt.line->branchname);
if (retval != 4) return;
} else {
retval = sscanf(input, "%" SHORTLEN_S "s @%" SHORTLEN_S "s %" SHORTLEN_S "s",
opt.line->interface,
opt.line->chainlabel,
opt.line->branchname);
if (retval != 3) return;
opt.line->count = 1;
}
opt.parser=opt.parser|IPF_DATA;
}
void ipf_parse_ips(char *input, unsigned char mode)
{
int host1, host2, host3, host4, port;
int retval;
char ip[IPLEN];
if (mode == (IPF_OPT_SRC|IPF_OPT_RES|IPF_OPT_RPORT) || mode == (IPF_OPT_DST|IPF_OPT_RES|IPF_OPT_RPORT)) {
char name[255], *ptr, portname[32];
ptr = strchr(input, '['); *ptr = ' ';
retval = sscanf(input, "%255s %3d.%3d.%3d.%3d],%32s",
name, &host1, &host2, &host3, &host4, portname);
if(retval != 6) return;
} else if (mode == (IPF_OPT_SRC|IPF_OPT_RES|IPF_OPT_PORT) || mode == (IPF_OPT_DST|IPF_OPT_RES|IPF_OPT_PORT)) {
char name[255], *ptr;
ptr = strchr(input, '['); *ptr = ' ';
retval = sscanf(input, "%255s %3d.%3d.%3d.%3d],%5d",
name, &host1, &host2, &host3, &host4, &port);
if(retval != 6) return;
} else if (mode == (IPF_OPT_SRC|IPF_OPT_RES) || mode == (IPF_OPT_DST|IPF_OPT_RES)) {
char name[255], *ptr;
ptr = strchr(input, '['); *ptr = ' ';
retval = sscanf(input, "%255s %3d.%3d.%3d.%3d]",
name, &host1, &host2, &host3, &host4);
if(retval != 5) return;
} else if (mode == (IPF_OPT_SRC|IPF_OPT_RPORT) || mode == (IPF_OPT_DST|IPF_OPT_RPORT)) {
char portname[32];
retval = sscanf(input, "%3d.%3d.%3d.%3d,%32s",
&host1, &host2, &host3, &host4, portname);
if(retval != 5) return;
} else if (mode == (IPF_OPT_SRC|IPF_OPT_PORT) || mode == (IPF_OPT_DST|IPF_OPT_PORT)) {
retval = sscanf(input, "%3d.%3d.%3d.%3d,%5d",
&host1, &host2, &host3, &host4, &port);
if(retval != 5) return;
} else if (mode == IPF_OPT_SRC || mode == IPF_OPT_DST) {
retval = sscanf(input, "%3d.%3d.%3d.%3d",
&host1, &host2, &host3, &host4);
if(retval != 4) return;
} else {
return;
}
snprintf(ip, IPLEN, "%d.%d.%d.%d", host1, host2, host3, host4);
if(mode & IPF_OPT_SRC) {
if(convert_ip(ip, &opt.line->shost) == IN_ADDR_ERROR) return;
opt.parser=opt.parser|IPF_SRC_IP;
if(mode & IPF_OPT_PORT) {
opt.line->sport = port;
opt.parser=opt.parser|IPF_SRC_PORT;
}
} else {
if(convert_ip(ip, &opt.line->dhost) == IN_ADDR_ERROR) return;
opt.parser=opt.parser|IPF_DST_IP;
if(mode & IPF_OPT_PORT) {
opt.line->dport = port;
opt.parser=opt.parser|IPF_DST_PORT;
}
}
}
void ipf_parse_proto(char *input)
{
if(isdigit((int)input[0])) {
opt.line->protocol = atoi(input);
} else {
struct protoent *proto;
proto = getprotobyname(input);
if (proto != NULL)
opt.line->protocol = proto->p_proto;
}
if (opt.line->protocol != 0) {
opt.parser=opt.parser|IPF_PROTO;
} else {
fprintf(stderr, "Unknown protocol (not in /etc/protocols), ignoring: %s\n", input);
opt.parser=opt.parser|IPF_NO_HIT;
}
}
void ipf_parse_flags(char *input)
{
while (*input != '\0') {
if(*input == 'S') opt.line->flags = opt.line->flags | TCP_SYN;
if(*input == 'A') opt.line->flags = opt.line->flags | TCP_ACK;
if(*input == 'F') opt.line->flags = opt.line->flags | TCP_FIN;
if(*input == 'R') opt.line->flags = opt.line->flags | TCP_RST;
if(*input == 'P') opt.line->flags = opt.line->flags | TCP_PSH;
if(*input == 'U') opt.line->flags = opt.line->flags | TCP_URG;
input++;
}
}
unsigned char flex_ipfilter(char *input, int linenum)
{
opt.parser = 0;
init_line();
ipf_scan_string(input);
ipflex();
ipf_delete_buffer(YY_CURRENT_BUFFER);
if (opt.parser & IPF_NO_HIT)
return PARSE_NO_HIT;
if (opt.parser == (IPF_DATE|IPF_DATA|IPF_PROTO|IPF_SRC_IP|IPF_DST_IP|IPF_SRC_PORT|IPF_DST_PORT)) {
return PARSE_OK;
} else {
if(opt.verbose)
fprintf(stderr, "ipfilter parse error in line %d, ignoring.\n", linenum);
if(opt.verbose == 2)
fprintf(stderr, "input was: \"%s\"\n", input);
return PARSE_WRONG_FORMAT;
}
}
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