denyhosts/clamav/libclamav/regex_list.c

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2022-10-22 18:41:00 +08:00
/*
* Match a string against a list of patterns/regexes.
*
* Copyright (C) 2013-2022 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
* Copyright (C) 2007-2013 Sourcefire, Inc.
*
* Authors: Török Edvin
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
* MA 02110-1301, USA.
*/
#if HAVE_CONFIG_H
#include "clamav-config.h"
#endif
#ifdef CL_THREAD_SAFE
#ifndef _REENTRANT
#define _REENTRANT
#endif
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <zlib.h>
#include <limits.h>
#include <sys/types.h>
#include "regex/regex.h"
#include "clamav.h"
#include "others.h"
#include "regex_list.h"
#include "matcher-ac.h"
#include "matcher.h"
#include "str.h"
#include "readdb.h"
#include "jsparse/textbuf.h"
#include "regex_suffix.h"
#include "default.h"
#include "hashtab.h"
#include "mpool.h"
/* Prototypes */
static regex_t *new_preg(struct regex_matcher *matcher);
static size_t reverse_string(char *pattern);
static cl_error_t add_pattern_suffix(void *cbdata, const char *suffix, size_t suffix_len, const struct regex_list *regex);
static cl_error_t add_static_pattern(struct regex_matcher *matcher, char *pattern);
/* ---------- */
#define MATCH_SUCCESS 0
#define MATCH_FAILED -1
/*
* Call this function when an unrecoverable error has occurred, (instead of exit).
*/
static void fatal_error(struct regex_matcher *matcher)
{
regex_list_done(matcher);
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matcher->list_inited = -1; /* the phishing module will know we tried to load an allow list, and failed, so it will disable itself too*/
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}
static inline char get_char_at_pos_with_skip(const struct pre_fixup_info *info, const char *buffer, size_t pos)
{
const char *str;
size_t realpos = 0;
if (!info) {
return (pos <= strlen(buffer)) ? buffer[pos > 0 ? pos - 1 : 0] : '\0';
}
str = info->pre_displayLink.data;
cli_dbgmsg("calc_pos_with_skip: skip:%llu, %llu - %llu \"%s\",\"%s\"\n", (long long unsigned)pos, (long long unsigned)info->host_start,
(long long unsigned)info->host_end, str, buffer);
pos += info->host_start;
while (str[realpos] && !isalnum(str[realpos])) realpos++;
for (; str[realpos] && (pos > 0); pos--) {
while (str[realpos] == ' ') realpos++;
realpos++;
}
while (str[realpos] == ' ') realpos++;
cli_dbgmsg("calc_pos_with_skip:%s\n", str + realpos);
return (pos > 0 && !str[realpos]) ? '\0' : str[realpos > 0 ? realpos - 1 : 0];
}
static int validate_subdomain(const struct regex_list *regex, const struct pre_fixup_info *pre_fixup, const char *buffer, size_t buffer_len, char *real_url, size_t real_len, char *orig_real_url)
{
char c;
size_t match_len;
if (!regex || !regex->pattern)
return 0;
match_len = strlen(regex->pattern);
if (((c = get_char_at_pos_with_skip(pre_fixup, buffer, buffer_len + 1)) == ' ' || c == '\0' || c == '/' || c == '?') &&
(match_len == buffer_len || /* full match */
(match_len < buffer_len &&
((c = get_char_at_pos_with_skip(pre_fixup, buffer, buffer_len - match_len)) == '.' || (c == ' ')))
/* subdomain matched*/)) {
/* we have an extra / at the end */
if (match_len > 0) match_len--;
cli_dbgmsg("Got a match: %s with %s\n", buffer, regex->pattern);
cli_dbgmsg("Before inserting .: %s\n", orig_real_url);
if (real_len >= match_len + 1) {
const size_t pos = real_len - match_len - 1;
if (real_url[pos] != '.') {
/* we need to shift left, and insert a '.'
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* we have an extra '.' at the beginning inserted by get_host to have room,
* orig_real_url has to be used here,
* because we want to overwrite that extra '.' */
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size_t orig_real_len = strlen(orig_real_url);
cli_dbgmsg("No dot here:%s\n", real_url + pos);
real_url = orig_real_url;
memmove(real_url, real_url + 1, orig_real_len - match_len - 1);
real_url[orig_real_len - match_len - 1] = '.';
cli_dbgmsg("After inserting .: %s\n", real_url);
}
}
return 1;
}
cli_dbgmsg("Ignoring false match: %s with %s, mismatched character: %c\n", buffer, regex->pattern, c);
return 0;
}
/*
* @matcher - matcher structure to use
* @real_url - href target
* @display_url - <a> tag contents
* @hostOnly - if you want to match only the host part
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* @is_allow_list_lookup - is this a lookup in an allow list?
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*
* @return - CL_SUCCESS - url doesn't match
* - CL_VIRUS - url matches list
*
* Do not send NULL pointers to this function!!
*
*/
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cl_error_t regex_list_match(struct regex_matcher *matcher, char *real_url, const char *display_url, const struct pre_fixup_info *pre_fixup, int hostOnly, const char **info, int is_allow_list_lookup)
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{
char *orig_real_url = real_url;
struct regex_list *regex;
size_t real_len, display_len, buffer_len;
char *buffer = NULL;
char *bufrev = NULL;
cl_error_t rc = CL_SUCCESS;
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// int filter_search_rc = 0;
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int root;
struct cli_ac_data mdata;
struct cli_ac_result *res = NULL;
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if (NULL == matcher) {
rc = CL_ENULLARG;
cli_errmsg("regex_list_match: matcher must be initialized\n");
goto done;
}
if (NULL == real_url) {
rc = CL_ENULLARG;
cli_errmsg("regex_list_match: real_url must be initialized\n");
goto done;
}
if (NULL == display_url) {
rc = CL_ENULLARG;
cli_errmsg("regex_list_match: display_url must be initialized\n");
goto done;
}
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*info = NULL;
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if (1 != matcher->list_inited) {
rc = CL_SUCCESS;
goto done;
}
if (0 == matcher->list_built) {
cli_errmsg("regex_list_match: matcher->list_built must be initialized\n");
rc = CL_ENULLARG;
goto done;
}
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/* skip initial '.' inserted by get_host */
if (real_url[0] == '.') real_url++;
if (display_url[0] == '.') display_url++;
real_len = strlen(real_url);
display_len = strlen(display_url);
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buffer_len = (hostOnly && !is_allow_list_lookup) ? real_len + 1 : real_len + display_len + 1 + 1;
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if (buffer_len < 3) {
/* too short, no match possible */
return CL_SUCCESS;
}
buffer = cli_malloc(buffer_len + 1);
if (!buffer) {
cli_errmsg("regex_list_match: Unable to allocate memory for buffer\n");
return CL_EMEM;
}
strncpy(buffer, real_url, real_len);
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buffer[real_len] = (!is_allow_list_lookup && hostOnly) ? '/' : ':';
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/*
* For H-type PDB signatures, real_url is actually the DisplayedHostname.
* RealHostname is not used.
*/
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if (!hostOnly || is_allow_list_lookup) {
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/* For all other PDB and WDB signatures concatenate Real:Displayed. */
strncpy(buffer + real_len + 1, display_url, display_len);
}
buffer[buffer_len - 1] = '/';
buffer[buffer_len] = 0;
cli_dbgmsg("Looking up in regex_list: %s\n", buffer);
if (CL_SUCCESS != (rc = cli_ac_initdata(&mdata, 0, 0, 0, CLI_DEFAULT_AC_TRACKLEN)))
return rc;
bufrev = cli_strdup(buffer);
if (!bufrev)
return CL_EMEM;
reverse_string(bufrev);
// TODO Add this back in once we improve the regex parsing code that finds
// suffixes to add to the filter.
//
// Reviewing Coverity bug reports we found that the return value to this
// filter_search call was effectively being ignored, causing no filtering
// to occur. Fixing this issue resulted in a unit test that uses the
// following match list regex to fail when searching for `ebay.com`.:
//
// .+\\.paypal\\.(com|de|fr|it)([/?].*)?:.+\\.ebay\\.(at|be|ca|ch|co\\.uk|de|es|fr|ie|in|it|nl|ph|pl|com(\\.(au|cn|hk|my|sg))?)/
//
// After investigating further, this is because the regex_list_add_pattern
// call, which parses the regex for suffixes and attempts to add these to
// the filter, can't handle the `com(\\.(au|cn|hk|my|sg))?` portion of
// the regex. As a result, it only adds `ebay.at`, `ebay.be`, `ebay.ca`, up
// through `ebay.pl` into the filter). With the commented out code below
// uncommented, these suffixes not existing in the filter are treated as
// there not being a corresponding regex for ebay.com, causing no regex
// rules to be evaluated against the URL.
//
// We should get the regex parsing code working (and ensure it handles any
// other complex cases in daily.cdb) before re-enabling this code. The code
// has had no effect for 12+ years at this point, though, so it's probably
// safe to wait a bit longer without it.
//
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// filter_search_rc = filter_search(&matcher->filter, (const unsigned char *)bufrev, buffer_len);
// if (filter_search_rc == -1) {
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// free(buffer);
// free(bufrev);
// /* filter says this suffix doesn't match.
// * The filter has false positives, but no false
// * negatives */
// return CL_SUCCESS;
//}
rc = cli_ac_scanbuff((const unsigned char *)bufrev, buffer_len, NULL, (void *)&regex, &res, &matcher->suffixes, &mdata, 0, 0, NULL, AC_SCAN_VIR, NULL);
free(bufrev);
cli_ac_freedata(&mdata);
rc = CL_SUCCESS;
root = matcher->root_regex_idx;
while (res || root) {
struct cli_ac_result *q;
if (!res) {
regex = matcher->suffix_regexes[root].head;
root = 0;
} else {
regex = res->customdata;
}
while (!rc && regex) {
/* loop over multiple regexes corresponding to
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* this suffix */
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if (!regex->preg) {
/* we matched a static pattern */
rc = validate_subdomain(regex, pre_fixup, buffer, buffer_len, real_url, real_len, orig_real_url);
} else {
rc = !cli_regexec(regex->preg, buffer, 0, NULL, 0);
}
if (rc) *info = regex->pattern;
regex = regex->nxt;
}
if (res) {
q = res;
res = res->next;
free(q);
}
}
free(buffer);
if (!rc)
cli_dbgmsg("Lookup result: not in regex list\n");
else
cli_dbgmsg("Lookup result: in regex list\n");
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done:
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return rc;
}
/* Initialization & loading */
/* Initializes @matcher, allocating necessary substructures */
cl_error_t init_regex_list(struct regex_matcher *matcher, uint8_t dconf_prefiltering)
{
#ifdef USE_MPOOL
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mpool_t *mp = NULL;
#endif
cl_error_t rc = CL_SUCCESS;
if (NULL == matcher) {
cli_errmsg("init_regex_list: matcher must be initialized\n");
rc = CL_ENULLARG;
goto done;
}
#ifdef USE_MPOOL
mp = matcher->mempool;
if (NULL == mp) {
cli_errmsg("init_regex_list: matcher->mempool must be initialized\n");
rc = CL_ENULLARG;
goto done;
}
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#endif
memset(matcher, 0, sizeof(*matcher));
matcher->list_inited = 1;
matcher->list_built = 0;
matcher->list_loaded = 0;
cli_hashtab_init(&matcher->suffix_hash, 512);
#ifdef USE_MPOOL
matcher->mempool = mp;
matcher->suffixes.mempool = mp;
#endif
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if ((rc = cli_ac_init(&matcher->suffixes, 2, 32, dconf_prefiltering))) {
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goto done;
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}
#ifdef USE_MPOOL
matcher->sha256_hashes.mempool = mp;
matcher->hostkey_prefix.mempool = mp;
#endif
if ((rc = cli_bm_init(&matcher->sha256_hashes))) {
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goto done;
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}
if ((rc = cli_bm_init(&matcher->hostkey_prefix))) {
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goto done;
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}
filter_init(&matcher->filter);
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done:
return rc;
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}
static int functionality_level_check(char *line)
{
char *ptmin;
char *ptmax;
size_t j;
ptmin = strrchr(line, ':');
if (!ptmin)
return CL_SUCCESS;
ptmin++;
ptmax = strchr(ptmin, '-');
if (!ptmax)
return CL_SUCCESS; /* there is no functionality level specified, so we're ok */
else {
size_t min, max;
ptmax++;
for (j = 0; j + ptmin + 1 < ptmax; j++)
if (!isdigit(ptmin[j]))
return CL_SUCCESS; /* not numbers, not functionality level */
for (j = 0; j < strlen(ptmax); j++)
if (!isdigit(ptmax[j]))
return CL_SUCCESS; /* see above */
ptmax[-1] = '\0';
min = atoi(ptmin);
if (strlen(ptmax) == 0)
max = INT_MAX;
else
max = atoi(ptmax);
if (min > cl_retflevel()) {
cli_dbgmsg("regex list line %s not loaded (required f-level: %u)\n", line, (unsigned int)min);
return CL_EMALFDB;
}
if (max < cl_retflevel())
return CL_EMALFDB;
ptmin[-1] = '\0';
return CL_SUCCESS;
}
}
static int add_hash(struct regex_matcher *matcher, char *pattern, const char fl, int is_prefix)
{
int rc;
struct cli_bm_patt *pat = MPOOL_CALLOC(matcher->mempool, 1, sizeof(*pat));
struct cli_matcher *bm;
const char *vname = NULL;
if (!pat)
return CL_EMEM;
pat->pattern = (unsigned char *)CLI_MPOOL_HEX2STR(matcher->mempool, pattern);
if (!pat->pattern)
return CL_EMALFDB;
pat->length = 32;
if (is_prefix) {
pat->length = 4;
bm = &matcher->hostkey_prefix;
} else {
bm = &matcher->sha256_hashes;
}
if (!matcher->sha256_pfx_set.keys) {
if ((rc = cli_hashset_init(&matcher->sha256_pfx_set, 1048576, 90))) {
return rc;
}
}
if (fl != 'W' && pat->length == 32 &&
cli_hashset_contains(&matcher->sha256_pfx_set, cli_readint32(pat->pattern)) &&
cli_bm_scanbuff(pat->pattern, 32, &vname, NULL, &matcher->sha256_hashes, 0, NULL, NULL, NULL) == CL_VIRUS) {
if (*vname == 'W') {
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/* hash is allowed in local.gdb */
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cli_dbgmsg("Skipping hash %s\n", pattern);
MPOOL_FREE(matcher->mempool, pat->pattern);
MPOOL_FREE(matcher->mempool, pat);
return CL_SUCCESS;
}
}
pat->virname = MPOOL_MALLOC(matcher->mempool, 1);
if (!pat->virname) {
free(pat);
cli_errmsg("add_hash: Unable to allocate memory for path->virname\n");
return CL_EMEM;
}
*pat->virname = fl;
cli_hashset_addkey(&matcher->sha256_pfx_set, cli_readint32(pat->pattern));
if ((rc = cli_bm_addpatt(bm, pat, "*"))) {
cli_errmsg("add_hash: failed to add BM pattern\n");
free(pat->pattern);
free(pat->virname);
free(pat);
return CL_EMALFDB;
}
return CL_SUCCESS;
}
/* Load patterns/regexes from file */
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cl_error_t load_regex_matcher(struct cl_engine *engine, struct regex_matcher *matcher, FILE *fd, unsigned int *signo, unsigned int options, int is_allow_list_lookup, struct cli_dbio *dbio, uint8_t dconf_prefiltering)
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{
cl_error_t rc;
int line = 0, entry = 0;
char buffer[FILEBUFF];
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if (NULL == matcher) {
cli_errmsg("load_regex_matcher: matcher must be initialized\n");
return CL_ENULLARG;
}
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if (matcher->list_inited == -1)
return CL_EMALFDB; /* already failed to load */
if (!fd && !dbio) {
cli_errmsg("Unable to load regex list (null file)\n");
return CL_ENULLARG;
}
cli_dbgmsg("Loading regex_list\n");
if (!matcher->list_inited) {
rc = init_regex_list(matcher, dconf_prefiltering);
if (!matcher->list_inited) {
cli_errmsg("Regex list failed to initialize!\n");
fatal_error(matcher);
return rc;
}
}
/*
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* Regexlist db format, common to .wdb (allow list) and .pdb (domain list) files.
*
* Multiple lines of form, (empty lines are skipped):
* Flags RealURL DisplayedURL
* Where:
* Flags:
*
* .pdb files:
* R - regex, H - host-only, followed by (optional) 3-digit hexnumber representing
* flags that should be filtered.
* [i.e. phishcheck urls.flags that we don't want to be done for this particular host]
*
* .wdb files:
* X - full URL regex
* Y - host-only regex
* M - host simple pattern
*
* If a line in the file doesn't conform to this format, loading fails
*
*/
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while (cli_dbgets(buffer, FILEBUFF, fd, dbio)) {
char *pattern;
char *flags;
size_t pattern_len;
cli_chomp(buffer);
line++;
if (!*buffer)
continue; /* skip empty lines */
if (buffer[0] == '#')
continue;
if (functionality_level_check(buffer))
continue;
if (engine->cb_sigload && engine->cb_sigload("phishing", buffer, ~options & CL_DB_OFFICIAL, engine->cb_sigload_ctx)) {
cli_dbgmsg("load_regex_matcher: skipping %s due to callback\n", buffer);
continue;
}
entry++;
pattern = strchr(buffer, ':');
if (!pattern) {
cli_errmsg("Malformed regex list line %d\n", line);
fatal_error(matcher);
return CL_EMALFDB;
}
/*pattern[0]='\0';*/
flags = buffer + 1;
pattern++;
pattern_len = strlen(pattern);
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/* '-3' to leave room for the '/' and null being
* appended below.
*/
if ((pattern - buffer) + pattern_len < (FILEBUFF - 3)) {
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pattern[pattern_len] = '/';
pattern[pattern_len + 1] = '\0';
} else {
cli_errmsg("Overlong regex line %d\n", line);
fatal_error(matcher);
return CL_EMALFDB;
}
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if ((buffer[0] == 'R' && !is_allow_list_lookup) || ((buffer[0] == 'X' || buffer[0] == 'Y') && is_allow_list_lookup)) {
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/* regex for hostname*/
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if ((rc = regex_list_add_pattern(matcher, pattern))) {
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return rc == CL_EMEM ? CL_EMEM : CL_EMALFDB;
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}
} else if ((buffer[0] == 'H' && !is_allow_list_lookup) || (buffer[0] == 'M' && is_allow_list_lookup)) {
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/*matches displayed host*/
if ((rc = add_static_pattern(matcher, pattern)))
return rc == CL_EMEM ? CL_EMEM : CL_EMALFDB;
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} else if (buffer[0] == 'S' && (!is_allow_list_lookup || pattern[0] == 'W')) {
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pattern[pattern_len] = '\0';
if (pattern[0] == 'W')
flags[0] = 'W';
if ((pattern[0] == 'W' || pattern[0] == 'F' || pattern[0] == 'P') && pattern[1] == ':') {
pattern += 2;
if ((rc = add_hash(matcher, pattern, flags[0], pattern[-2] == 'P'))) {
cli_errmsg("Error loading at line: %d\n", line);
return rc == CL_EMEM ? CL_EMEM : CL_EMALFDB;
}
} else {
cli_errmsg("Error loading line: %d, %c\n", line, *pattern);
return CL_EMALFDB;
}
} else {
return CL_EMALFDB;
}
}
matcher->list_loaded = 1;
if (signo)
*signo += entry;
return CL_SUCCESS;
}
/* Build the matcher list */
cl_error_t cli_build_regex_list(struct regex_matcher *matcher)
{
cl_error_t rc;
if (!matcher)
return CL_SUCCESS;
if (!matcher->list_inited || !matcher->list_loaded) {
cli_errmsg("Regex list not loaded!\n");
return -1; /*TODO: better error code */
}
cli_dbgmsg("Building regex list\n");
cli_hashtab_free(&matcher->suffix_hash);
if ((rc = cli_ac_buildtrie(&matcher->suffixes)))
return rc;
matcher->list_built = 1;
cli_hashset_destroy(&matcher->sha256_pfx_set);
return CL_SUCCESS;
}
/* Done with this matcher, free resources */
void regex_list_done(struct regex_matcher *matcher)
{
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if (NULL == matcher) {
cli_errmsg("regex_list_done: matcher must be initialized\n");
goto done;
}
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if (matcher->list_inited == 1) {
size_t i;
cli_ac_free(&matcher->suffixes);
if (matcher->suffix_regexes) {
for (i = 0; i < matcher->suffix_cnt; i++) {
struct regex_list *r = matcher->suffix_regexes[i].head;
while (r) {
struct regex_list *q = r;
r = r->nxt;
free(q->pattern);
free(q);
}
}
free(matcher->suffix_regexes);
matcher->suffix_regexes = NULL;
}
if (matcher->all_pregs) {
for (i = 0; i < matcher->regex_cnt; i++) {
regex_t *r = matcher->all_pregs[i];
cli_regfree(r);
MPOOL_FREE(matcher->mempool, r);
}
MPOOL_FREE(matcher->mempool, matcher->all_pregs);
}
cli_hashtab_free(&matcher->suffix_hash);
cli_bm_free(&matcher->sha256_hashes);
cli_bm_free(&matcher->hostkey_prefix);
}
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done:
return;
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}
int is_regex_ok(struct regex_matcher *matcher)
{
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int ret = 0;
if (NULL == matcher) {
cli_errmsg("is_regex_ok: matcher must be initialized\n");
} else {
ret = (!matcher->list_inited || matcher->list_inited != -1); /* either we don't have a regexlist, or we initialized it successfully */
}
return ret;
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}
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static cl_error_t add_newsuffix(struct regex_matcher *matcher, struct regex_list *info, const char *suffix, size_t len)
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{
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struct cli_matcher *root = NULL;
struct cli_ac_patt *new = NULL;
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size_t i;
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cl_error_t ret = CL_SUCCESS;
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if (NULL == matcher) {
cli_errmsg("add_newsuffix: matcher must be initialized\n");
ret = CL_ENULLARG;
goto done;
}
root = &matcher->suffixes;
if (NULL == root) {
cli_errmsg("add_newsuffix: root must be initialized\n");
ret = CL_ENULLARG;
goto done;
}
if (NULL == suffix) {
cli_errmsg("add_newsuffix: suffix must be initialized\n");
ret = CL_ENULLARG;
goto done;
}
new = MPOOL_CALLOC(matcher->mempool, 1, sizeof(*new));
if (!new) {
cli_errmsg("add_newsuffix: Unable to allocate memory for new\n");
ret = CL_EMEM;
goto done;
}
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new->rtype = 0;
new->type = 0;
new->sigid = 0;
new->parts = 0;
new->partno = 0;
new->mindist = 0;
new->maxdist = 0;
new->offset_min = CLI_OFF_ANY;
new->length[0] = (uint16_t)len;
new->ch[0] = new->ch[1] |= CLI_MATCH_IGNORE;
if (new->length[0] > root->maxpatlen)
root->maxpatlen = new->length[0];
new->pattern = MPOOL_MALLOC(matcher->mempool, sizeof(new->pattern[0]) * len);
if (!new->pattern) {
cli_errmsg("add_newsuffix: Unable to allocate memory for new->pattern\n");
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ret = CL_EMEM;
goto done;
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}
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for (i = 0; i < len; i++) {
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new->pattern[i] = suffix[i]; /*new->pattern is short int* */
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}
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new->customdata = info;
new->virname = NULL;
if ((ret = cli_ac_addpatt(root, new))) {
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goto done;
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}
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if (filter_add_static(&matcher->filter, (const unsigned char *)suffix, len, "regex") < 0) {
cli_errmsg("add_newsuffix: Unable to add filter\n");
ret = CL_ERROR;
goto done;
}
done:
if (CL_SUCCESS != ret) {
if (NULL != new) {
if (NULL != new->pattern) {
MPOOL_FREE(matcher->mempool, new->pattern);
}
MPOOL_FREE(matcher->mempool, new);
}
}
return ret;
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}
#define MODULE "regex_list: "
/* ------ load a regex, determine suffix, determine suffix2regexlist map ---- */
static void list_add_tail(struct regex_list_ht *ht, struct regex_list *regex)
{
if (!ht->head)
ht->head = regex;
if (ht->tail) {
ht->tail->nxt = regex;
}
ht->tail = regex;
}
static cl_error_t add_pattern_suffix(void *cbdata, const char *suffix, size_t suffix_len, const struct regex_list *iregex)
{
struct regex_matcher *matcher = cbdata;
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struct regex_list *regex = NULL;
const struct cli_element *el = NULL;
cl_error_t ret = CL_SUCCESS;
if (NULL == matcher) {
cli_errmsg("add_pattern_suffix: matcher must be initialized\n");
ret = CL_ENULLARG;
goto done;
}
if (NULL == suffix) {
cli_errmsg("add_pattern_suffix: suffix must be initialized\n");
ret = CL_ENULLARG;
goto done;
}
if (NULL == iregex) {
cli_errmsg("add_pattern_suffix: iregex must be initialized\n");
ret = CL_ENULLARG;
goto done;
}
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CLI_MALLOC(regex, sizeof(*regex),
cli_errmsg("add_pattern_suffix: Unable to allocate memory for regex\n");
ret = CL_EMEM);
if (NULL == iregex->pattern) {
regex->pattern = NULL;
} else {
CLI_STRDUP(iregex->pattern, regex->pattern,
cli_errmsg("add_pattern_suffix: unable to strdup iregex->pattern");
ret = CL_EMEM);
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}
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regex->preg = iregex->preg;
regex->nxt = NULL;
el = cli_hashtab_find(&matcher->suffix_hash, suffix, suffix_len);
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/* TODO: what if suffixes are prefixes of eachother and only one will
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* match? */
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if (el) {
/* existing suffix */
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if ((size_t)el->data >= matcher->suffix_cnt) {
cli_errmsg("add_pattern_suffix: el-> data too large");
ret = CL_ERROR;
goto done;
}
list_add_tail(&matcher->suffix_regexes[(size_t)el->data], regex);
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} else {
/* new suffix */
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size_t n = matcher->suffix_cnt;
el = cli_hashtab_insert(&matcher->suffix_hash, suffix, suffix_len, (cli_element_data)n);
CLI_REALLOC(matcher->suffix_regexes,
(n + 1) * sizeof(*matcher->suffix_regexes),
cli_errmsg("add_pattern_suffix: Unable to reallocate memory for matcher->suffix_regexes\n");
ret = CL_EMEM);
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matcher->suffix_regexes[n].tail = regex;
matcher->suffix_regexes[n].head = regex;
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if (suffix[0] == '/' && suffix[1] == '\0') {
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matcher->root_regex_idx = n;
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}
ret = add_newsuffix(matcher, regex, suffix, suffix_len);
if (CL_SUCCESS != ret) {
cli_hashtab_delete(&matcher->suffix_hash, suffix, suffix_len);
/*shrink the size back to what it was.*/
CLI_REALLOC(matcher->suffix_regexes, n * sizeof(*matcher->suffix_regexes));
} else {
matcher->suffix_cnt++;
}
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}
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done:
if (CL_SUCCESS != ret) {
FREE(regex->pattern);
FREE(regex);
}
return ret;
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}
static size_t reverse_string(char *pattern)
{
size_t len = strlen(pattern);
size_t i;
for (i = 0; i < (len / 2); i++) {
char aux = pattern[i];
pattern[i] = pattern[len - i - 1];
pattern[len - i - 1] = aux;
}
return len;
}
static regex_t *new_preg(struct regex_matcher *matcher)
{
regex_t *r;
matcher->all_pregs = MPOOL_REALLOC(matcher->mempool, matcher->all_pregs, ++matcher->regex_cnt * sizeof(*matcher->all_pregs));
if (!matcher->all_pregs) {
cli_errmsg("new_preg: Unable to reallocate memory\n");
return NULL;
}
r = MPOOL_MALLOC(matcher->mempool, sizeof(*r));
if (!r) {
cli_errmsg("new_preg: Unable to allocate memory\n");
return NULL;
}
matcher->all_pregs[matcher->regex_cnt - 1] = r;
return r;
}
static cl_error_t add_static_pattern(struct regex_matcher *matcher, char *pattern)
{
size_t len;
struct regex_list regex;
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cl_error_t rc = CL_EMEM;
len = reverse_string(pattern);
regex.nxt = NULL;
CLI_STRDUP(pattern, regex.pattern,
cli_errmsg("add_static_pattern: Cannot allocate memory for regex.pattern\n");
rc = CL_EMEM);
regex.preg = NULL;
rc = add_pattern_suffix(matcher, pattern, len, &regex);
done:
FREE(regex.pattern);
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return rc;
}
cl_error_t regex_list_add_pattern(struct regex_matcher *matcher, char *pattern)
{
cl_error_t rc;
regex_t *preg;
size_t len;
/* we only match the host, so remove useless stuff */
const char remove_end[] = "([/?].*)?/";
const char remove_end2[] = "([/?].*)/";
len = strlen(pattern);
if (len > sizeof(remove_end)) {
if (strncmp(&pattern[len - sizeof(remove_end) + 1], remove_end, sizeof(remove_end) - 1) == 0) {
len -= sizeof(remove_end) - 1;
pattern[len++] = '/';
}
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}
if (len > sizeof(remove_end2)) {
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if (strncmp(&pattern[len - sizeof(remove_end2) + 1], remove_end2, sizeof(remove_end2) - 1) == 0) {
len -= sizeof(remove_end2) - 1;
pattern[len++] = '/';
}
}
pattern[len] = '\0';
preg = new_preg(matcher);
if (!preg)
return CL_EMEM;
rc = cli_regex2suffix(pattern, preg, add_pattern_suffix, (void *)matcher);
if (rc) {
cli_regfree(preg);
}
return rc;
}