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|
/**************************************
**
** PARSER RULES
**
** (a) must set record->host
** (eventually to dummy value)
**
** (b) must set record->prefix
** (itoa(status))
**
**
**************************************/
/* for strptime */
#define _XOPEN_SOURCE 500
#include "config_xor.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <time.h>
#ifdef USE_LOGFILE_MONITOR
#undef FIL__
#define FIL__ _("sh_log_parse_apache.c")
/* Debian/Ubuntu: libpcre3-dev */
#ifdef HAVE_PCRE_PCRE_H
#include <pcre/pcre.h>
#else
#include <pcre.h>
#endif
#include "samhain.h"
#include "sh_pthread.h"
#include "sh_log_check.h"
#include "sh_utils.h"
#include "sh_string.h"
extern int flag_err_debug;
struct sh_fileinfo_apache {
pcre * line_regex;
int * line_ovector; /* captured substrings */
int line_ovecnum; /* how many captured */
int pos_host;
int pos_status;
int pos_time;
char * format_time;
};
static const char lf_error0[] = N_("%error");
static const char lf_common0[] = N_("%h %l %u %t \"%r\" %>s %b");
static const char lf_combined0[] = N_("%h %l %u %t \"%r\" %>s %b \"%{Referer}i\" \"%{User-Agent}i\"");
/* This variable is not used anywhere. It only exist
* to assign &new to them, which keeps gcc from
* putting it into a register, and avoids the 'clobbered
* by longjmp' warning. And no, 'volatile' proved insufficient.
*/
void * sh_dummy_65_new = NULL;
void * sh_dummy_66_fti = NULL;
void * sh_dummy_67_ftr = NULL;
void * sh_eval_fileinfo_apache(char * str)
{
struct sh_fileinfo_apache * result = NULL;
unsigned int i, quotes;
unsigned int nfields = 64;
size_t lengths[64];
char * new = NULL;
char ** splits;
char * token;
sh_string * re_string;
char * p;
volatile int p_host = -1;
volatile int p_status = -1;
volatile int p_time = -1;
char * f_time = NULL;
const char * error;
int erroffset;
/* Take the address to keep gcc from putting them into registers.
* Avoids the 'clobbered by longjmp' warning.
*/
sh_dummy_65_new = (void*) &new;
sh_dummy_66_fti = (void*) &f_time;
sh_dummy_67_ftr = (void*) &result;
if (0 == strncmp("common", str, 6))
{
new = sh_util_strdup(_(lf_common0));
}
else if (0 == strncmp("combined", str, 8))
{
new = sh_util_strdup(_(lf_combined0));
}
else if (0 == strncmp("error", str, 8))
{
new = sh_util_strdup(_(lf_error0));
}
else
{
new = sh_util_strdup(str);
}
if (flag_err_debug == S_TRUE)
{
SH_MUTEX_LOCK(mutex_thread_nolog);
sh_error_handle(SH_ERR_ALL, FIL__, __LINE__, 0, MSG_E_SUBGEN,
new,
_("eval_fileinfo"));
SH_MUTEX_UNLOCK(mutex_thread_nolog);
}
splits = split_array_ws(new, &nfields, lengths);
if (nfields < 1)
{
SH_FREE(splits);
SH_FREE(new);
return NULL;
}
/* Build the regex string re_string
*/
re_string = sh_string_new(0);
sh_string_add_from_char(re_string, "^");
for (i = 0; i < nfields; ++i)
{
if (i > 0)
sh_string_add_from_char(re_string, " ");
if (splits[i][0] != '"')
quotes = 0;
else
quotes = 1;
if (quotes && lengths[i] > 1 && splits[i][lengths[i]-1] == '"')
{
splits[i][lengths[i]-1] = '\0'; /* cut trailing quote */
token = &(splits[i][1]);
} else {
token = splits[i];
}
if(quotes)
{
if(strcmp(token, "%r") == 0 ||
strstr(token, _("{Referer}")) != NULL ||
strstr(token, _("{User-Agent}")) != NULL ||
strstr(token, _("{X-Forwarded-For}")) != NULL )
{
/*
p = "\"([^\"\\\\]*(?:\\\\.[^\"\\\\]*)*)\"";
sh_string_add_from_char(re_string, p);
*/
sh_string_add_from_char(re_string, "\"([^");
sh_string_add_from_char(re_string, "\"\\\\");
sh_string_add_from_char(re_string, "]*");
sh_string_add_from_char(re_string, "(?:");
sh_string_add_from_char(re_string, "\\\\.");
sh_string_add_from_char(re_string, "[^\"");
sh_string_add_from_char(re_string, "\\\\]*");
sh_string_add_from_char(re_string, ")*)\"");
}
else
{
sh_string_add_from_char(re_string, "(");
sh_string_add_from_char(re_string, "\\S+");
sh_string_add_from_char(re_string, ")");
}
}
else if (token[0] == 'R' && token[1] == 'E' && token[2] == '{' && token[strlen(token)-1] == '}')
{
char * lb = strchr(token, '{');
char * rb = strrchr(token, '}');
if (lb && rb)
{
++lb; *rb = '\0';
sh_string_add_from_char(re_string, lb);
}
}
else if (token[0] == '%' && token[strlen(token)-1] == 't')
{
char * lb = strchr(token, '{');
char * rb = strchr(token, '}');
sh_string_add_from_char(re_string, "\\[");
sh_string_add_from_char(re_string, "([^");
sh_string_add_from_char(re_string, "(\\]");
sh_string_add_from_char(re_string, "]+)");
sh_string_add_from_char(re_string, "\\]");
p_time = i+1;
if (lb && rb)
{
++lb; *rb = '\0';
f_time = sh_util_strdup(lb);
}
else
{
f_time = sh_util_strdup(_("%d/%b/%Y:%T"));
}
}
else if (token[0] == '%' && token[1] == 'e' && 0 == strcmp(token, _("%error")))
{
sh_string_add_from_char(re_string, "\\[");
sh_string_add_from_char(re_string, "([^");
sh_string_add_from_char(re_string, "]");
sh_string_add_from_char(re_string, "]+)");
sh_string_add_from_char(re_string, "\\]");
p_time = i+1; f_time = sh_util_strdup(_("%a %b %d %T %Y")); ++i;
sh_string_add_from_char(re_string, " ");
sh_string_add_from_char(re_string, "\\[");
sh_string_add_from_char(re_string, "([^");
sh_string_add_from_char(re_string, "]");
sh_string_add_from_char(re_string, "]+)");
sh_string_add_from_char(re_string, "\\]");
p_status = i+1;
sh_string_add_from_char(re_string, " ");
p = "(.+)";
sh_string_add_from_char(re_string, p);
nfields = 3;
break;
}
else
{
sh_string_add_from_char(re_string, "(");
sh_string_add_from_char(re_string, "\\S+");
sh_string_add_from_char(re_string, ")");
if (token[0] == '%' && token[strlen(token)-1] == 's')
p_status = i+1;
else if (token[0] == '%' && token[strlen(token)-1] == 'v')
p_host = i+1;
}
}
sh_string_add_from_char(re_string, "$");
if (flag_err_debug == S_TRUE)
{
SH_MUTEX_LOCK(mutex_thread_nolog);
sh_error_handle(SH_ERR_ALL, FIL__, __LINE__, 0, MSG_E_SUBGEN,
sh_string_str(re_string),
_("eval_fileinfo"));
SH_MUTEX_UNLOCK(mutex_thread_nolog);
}
result = SH_ALLOC(sizeof(struct sh_fileinfo_apache));
result->line_regex = pcre_compile(sh_string_str(re_string), 0,
&error, &erroffset, NULL);
if (!(result->line_regex))
{
sh_string * msg = sh_string_new(0);
sh_string_add_from_char(msg, _("Bad regex: "));
sh_string_add_from_char(msg, sh_string_str(re_string));
SH_MUTEX_LOCK(mutex_thread_nolog);
sh_error_handle(SH_ERR_ERR, FIL__, __LINE__, 0, MSG_E_SUBGEN,
sh_string_str(msg),
_("eval_fileinfo"));
SH_MUTEX_UNLOCK(mutex_thread_nolog);
SH_FREE(result);
SH_FREE(splits);
SH_FREE(new);
sh_string_destroy(&msg);
sh_string_destroy(&re_string);
return NULL;
}
sh_string_destroy(&re_string);
result->line_ovector = SH_ALLOC(sizeof(int) * (nfields+1) * 3);
result->line_ovecnum = nfields;
result->pos_host = p_host;
result->pos_status = p_status;
result->pos_time = p_time;
result->format_time = f_time;
SH_FREE(splits);
SH_FREE(new);
return (void*)result;
}
struct sh_logrecord * sh_parse_apache (sh_string * logline, void * fileinfo)
{
static struct tm old_tm;
static time_t old_time;
char tstr[128];
char sstr[128];
const char * hstr;
int res;
const char **hstr_addr = (const char **) &hstr;
struct sh_fileinfo_apache * info = (struct sh_fileinfo_apache *) fileinfo;
if (sh_string_len(logline) > 0 && flag_err_debug == S_TRUE)
{
SH_MUTEX_LOCK(mutex_thread_nolog);
sh_error_handle(SH_ERR_ALL, FIL__, __LINE__, 0, MSG_E_SUBGEN,
sh_string_str(logline),
_("sh_parse_apache"));
SH_MUTEX_UNLOCK(mutex_thread_nolog);
}
if (logline == NULL || info == NULL)
{
return NULL;
}
res = pcre_exec(info->line_regex, NULL,
sh_string_str(logline), (int)sh_string_len(logline), 0,
0, info->line_ovector, (3*(1+info->line_ovecnum)));
if (res == (1+info->line_ovecnum))
{
struct sh_logrecord * record;
time_t timestamp = 0;
if (info->pos_time > 0)
{
res = pcre_copy_substring(sh_string_str(logline),
info->line_ovector, res,
info->pos_time, tstr, sizeof(tstr));
if (res <= 0)
goto corrupt;
}
else
{
res = 0;
timestamp = 0;
info->format_time = sh_util_strdup(_("%d/%b/%Y:%T"));
sl_strlcpy(tstr, _("01/Jan/1970:00:00:00"), sizeof(tstr));
}
if (res > 0)
{
struct tm btime;
char * ptr = NULL;
memset(&btime, '\0', sizeof(struct tm));
btime.tm_isdst = -1;
/* example: 01/Jun/2008:07:55:28 +0200 */
ptr = /*@i@*/strptime(tstr, info->format_time, &btime);
if (ptr)
{
timestamp = conv_timestamp(&btime, &old_tm, &old_time);
}
else
goto corrupt;
}
if (info->pos_status > 0)
{
res = pcre_copy_substring(sh_string_str(logline),
info->line_ovector, res,
info->pos_status, sstr, sizeof(sstr));
if (res <= 0)
goto corrupt;
}
else
{
sl_strlcpy(sstr, _("000"), sizeof(sstr));
}
if (info->pos_host > 0)
{
res = pcre_get_substring(sh_string_str(logline),
info->line_ovector, res,
info->pos_host, hstr_addr);
if (res <= 0)
goto corrupt;
}
else
{
hstr = NULL;
}
record = SH_ALLOC(sizeof(struct sh_logrecord));
record->timestamp = timestamp;
record->timestr = sh_string_new_from_lchar(tstr, strlen(tstr));
if (hstr)
record->host = sh_string_new_from_lchar(hstr, strlen(hstr));
else
record->host = sh_string_new_from_lchar(sh.host.name, strlen(sh.host.name));
record->message = sh_string_new_from_lchar(sh_string_str(logline),
sh_string_len(logline));
record->pid = PID_INVALID;
pcre_free_substring(hstr);
return record;
}
else
{
char msg[128];
sl_snprintf(msg, sizeof(msg), _("Incorrect number of captured subexpressions: %d vs %d"),
res, info->line_ovecnum);
SH_MUTEX_LOCK(mutex_thread_nolog);
sh_error_handle(SH_ERR_ERR, FIL__, __LINE__, 0, MSG_E_SUBGEN,
msg,
_("sh_parse_apache"));
SH_MUTEX_UNLOCK(mutex_thread_nolog);
}
/* Corrupted logline */
corrupt:
{
sh_string * msg = sh_string_new(0);
sh_string_add_from_char(msg, _("Corrupt logline: "));
sh_string_add_from_char(msg, sh_string_str(logline));
SH_MUTEX_LOCK(mutex_thread_nolog);
sh_error_handle(SH_ERR_ERR, FIL__, __LINE__, 0, MSG_E_SUBGEN,
sh_string_str(msg),
_("sh_parse_apache"));
SH_MUTEX_UNLOCK(mutex_thread_nolog);
sh_string_destroy(&msg);
}
return NULL;
}
/* USE_LOGFILE_MONITOR */
#endif
|
