denyhosts/clamscan/libclamav/others_common.c
2022-10-22 18:41:00 +08:00

1470 lines
42 KiB
C

/*
* Copyright (C) 2013-2022 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
* Copyright (C) 2007-2013 Sourcefire, Inc.
*
* Authors: Tomasz Kojm, Trog
*
* 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
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <stdlib.h>
#include <ctype.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <sys/types.h>
#include <sys/stat.h>
#include <dirent.h>
#ifndef _WIN32
#include <sys/wait.h>
#include <sys/time.h>
#endif
#include <time.h>
#include <fcntl.h>
#ifdef HAVE_PWD_H
#include <pwd.h>
#endif
#include <errno.h>
#include "target.h"
#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif
#ifdef HAVE_MALLOC_H
#include <malloc.h>
#endif
#include "clamav.h"
#include "others.h"
#include "str.h"
#include "platform.h"
#include "regex/regex.h"
#include "matcher-ac.h"
#include "str.h"
#include "entconv.h"
#define MSGBUFSIZ 8192
static unsigned char name_salt[16] = {16, 38, 97, 12, 8, 4, 72, 196, 217, 144, 33, 124, 18, 11, 17, 253};
#ifdef CL_THREAD_SAFE
#include <pthread.h>
static pthread_mutex_t cli_gentemp_mutex = PTHREAD_MUTEX_INITIALIZER;
#ifndef HAVE_CTIME_R
static pthread_mutex_t cli_ctime_mutex = PTHREAD_MUTEX_INITIALIZER;
#endif
static pthread_mutex_t cli_strerror_mutex = PTHREAD_MUTEX_INITIALIZER;
static pthread_key_t cli_ctx_tls_key;
static pthread_once_t cli_ctx_tls_key_once = PTHREAD_ONCE_INIT;
static void cli_ctx_tls_key_alloc(void)
{
pthread_key_create(&cli_ctx_tls_key, NULL);
}
void cli_logg_setup(const cli_ctx *ctx)
{
pthread_once(&cli_ctx_tls_key_once, cli_ctx_tls_key_alloc);
pthread_setspecific(cli_ctx_tls_key, ctx);
}
void cli_logg_unsetup(void)
{
pthread_setspecific(cli_ctx_tls_key, NULL);
}
static inline void *cli_getctx(void)
{
cli_ctx *ctx;
pthread_once(&cli_ctx_tls_key_once, cli_ctx_tls_key_alloc);
ctx = pthread_getspecific(cli_ctx_tls_key);
return ctx ? ctx->cb_ctx : NULL;
}
#else
static const cli_ctx *current_ctx = NULL;
void cli_logg_setup(const cli_ctx *ctx)
{
current_ctx = ctx;
}
static inline void *cli_getctx(void)
{
return current_ctx ? current_ctx->cb_ctx : NULL;
}
void cli_logg_unsetup(void)
{
}
#endif
uint8_t cli_debug_flag = 0;
uint8_t cli_always_gen_section_hash = 0;
static void fputs_callback(enum cl_msg severity, const char *fullmsg, const char *msg, void *context)
{
UNUSEDPARAM(severity);
UNUSEDPARAM(msg);
UNUSEDPARAM(context);
fputs(fullmsg, stderr);
}
static clcb_msg msg_callback = fputs_callback;
void cl_set_clcb_msg(clcb_msg callback)
{
msg_callback = callback;
}
#define MSGCODE(buff, len, x) \
va_list args; \
size_t len = sizeof(x) - 1; \
char buff[MSGBUFSIZ]; \
strncpy(buff, x, len); \
va_start(args, str); \
vsnprintf(buff + len, sizeof(buff) - len, str, args); \
buff[sizeof(buff) - 1] = '\0'; \
va_end(args)
void cli_warnmsg(const char *str, ...)
{
MSGCODE(buff, len, "LibClamAV Warning: ");
msg_callback(CL_MSG_WARN, buff, buff + len, cli_getctx());
}
void cli_errmsg(const char *str, ...)
{
MSGCODE(buff, len, "LibClamAV Error: ");
msg_callback(CL_MSG_ERROR, buff, buff + len, cli_getctx());
}
void cli_infomsg(const cli_ctx *ctx, const char *str, ...)
{
MSGCODE(buff, len, "LibClamAV info: ");
msg_callback(CL_MSG_INFO_VERBOSE, buff, buff + len, ctx ? ctx->cb_ctx : NULL);
}
void cli_dbgmsg_internal(const char *str, ...)
{
MSGCODE(buff, len, "LibClamAV debug: ");
fputs(buff, stderr);
}
int cli_matchregex(const char *str, const char *regex)
{
regex_t reg;
int match, flags = REG_EXTENDED | REG_NOSUB;
#ifdef _WIN32
flags |= REG_ICASE;
#endif
if (cli_regcomp(&reg, regex, flags) == 0) {
match = (cli_regexec(&reg, str, 0, NULL, 0) == REG_NOMATCH) ? 0 : 1;
cli_regfree(&reg);
return match;
}
return 0;
}
void *cli_malloc(size_t size)
{
void *alloc;
if (!size || size > CLI_MAX_ALLOCATION) {
cli_errmsg("cli_malloc(): Attempt to allocate %lu bytes. Please report to https://github.com/Cisco-Talos/clamav/issues\n", (unsigned long int)size);
return NULL;
}
alloc = malloc(size);
if (!alloc) {
perror("malloc_problem");
cli_errmsg("cli_malloc(): Can't allocate memory (%lu bytes).\n", (unsigned long int)size);
return NULL;
} else
return alloc;
}
void *cli_calloc(size_t nmemb, size_t size)
{
void *alloc;
if (!nmemb || !size || size > CLI_MAX_ALLOCATION || nmemb > CLI_MAX_ALLOCATION || (nmemb * size > CLI_MAX_ALLOCATION)) {
cli_errmsg("cli_calloc(): Attempt to allocate %lu bytes. Please report to https://github.com/Cisco-Talos/clamav/issues\n", (unsigned long int)nmemb * size);
return NULL;
}
alloc = calloc(nmemb, size);
if (!alloc) {
perror("calloc_problem");
cli_errmsg("cli_calloc(): Can't allocate memory (%lu bytes).\n", (unsigned long int)(nmemb * size));
return NULL;
} else
return alloc;
}
void *cli_realloc(void *ptr, size_t size)
{
void *alloc;
if (!size || size > CLI_MAX_ALLOCATION) {
cli_errmsg("cli_realloc(): Attempt to allocate %lu bytes. Please report to https://github.com/Cisco-Talos/clamav/issues\n", (unsigned long int)size);
return NULL;
}
alloc = realloc(ptr, size);
if (!alloc) {
perror("realloc_problem");
cli_errmsg("cli_realloc(): Can't re-allocate memory to %lu bytes.\n", (unsigned long int)size);
return NULL;
} else
return alloc;
}
void *cli_realloc2(void *ptr, size_t size)
{
void *alloc;
if (!size || size > CLI_MAX_ALLOCATION) {
cli_errmsg("cli_realloc2(): Attempt to allocate %lu bytes. Please report to https://github.com/Cisco-Talos/clamav/issues\n", (unsigned long int)size);
return NULL;
}
alloc = realloc(ptr, size);
if (!alloc) {
perror("realloc_problem");
cli_errmsg("cli_realloc2(): Can't re-allocate memory to %lu bytes.\n", (unsigned long int)size);
if (ptr)
free(ptr);
return NULL;
} else
return alloc;
}
char *cli_strdup(const char *s)
{
char *alloc;
if (s == NULL) {
cli_errmsg("cli_strdup(): s == NULL. Please report to https://github.com/Cisco-Talos/clamav/issues\n");
return NULL;
}
alloc = strdup(s);
if (!alloc) {
perror("strdup_problem");
cli_errmsg("cli_strdup(): Can't allocate memory (%u bytes).\n", (unsigned int)strlen(s));
return NULL;
}
return alloc;
}
/* returns converted timestamp, in case of error the returned string contains at least one character */
const char *cli_ctime(const time_t *timep, char *buf, const size_t bufsize)
{
const char *ret;
if (bufsize < 26) {
/* standard says we must have at least 26 bytes buffer */
cli_warnmsg("buffer too small for ctime\n");
return " ";
}
if ((uint32_t)(*timep) > 0x7fffffff) {
/* some systems can consider these timestamps invalid */
strncpy(buf, "invalid timestamp", bufsize - 1);
buf[bufsize - 1] = '\0';
return buf;
}
#ifdef HAVE_CTIME_R
#ifdef HAVE_CTIME_R_2
ret = ctime_r(timep, buf);
#else
ret = ctime_r(timep, buf, bufsize);
#endif
#else /* no ctime_r */
#ifdef CL_THREAD_SAFE
pthread_mutex_lock(&cli_ctime_mutex);
#endif
ret = ctime(timep);
if (ret) {
strncpy(buf, ret, bufsize - 1);
buf[bufsize - 1] = '\0';
ret = buf;
}
#ifdef CL_THREAD_SAFE
pthread_mutex_unlock(&cli_ctime_mutex);
#endif
#endif
/* common */
if (!ret) {
buf[0] = ' ';
buf[1] = '\0';
return buf;
}
return ret;
}
/**
* @brief Try hard to read the requested number of bytes
*
* @param fd File desriptor to read from.
* @param buff Buffer to read data into.
* @param count # of bytes to read.
* @return size_t # of bytes read.
* @return size_t (size_t)-1 if error.
*/
size_t cli_readn(int fd, void *buff, size_t count)
{
ssize_t retval;
size_t todo;
unsigned char *current;
todo = count;
current = (unsigned char *)buff;
do {
retval = read(fd, current, todo);
if (retval == 0) {
return (count - todo);
}
if (retval < 0) {
char err[128];
if (errno == EINTR) {
continue;
}
cli_errmsg("cli_readn: read error: %s\n", cli_strerror(errno, err, sizeof(err)));
return (size_t)-1;
}
if ((size_t)retval > todo) {
break;
} else {
todo -= retval;
}
current += retval;
} while (todo > 0);
return count;
}
/**
* @brief Try hard to write the specified number of bytes
*
* @param fd File descriptor to write to.
* @param buff Buffer to write from.
* @param count # of bytes to write.
* @return size_t # of bytes written
* @return size_t (size_t)-1 if error.
*/
size_t cli_writen(int fd, const void *buff, size_t count)
{
ssize_t retval;
size_t todo;
const unsigned char *current;
if (!buff) {
cli_errmsg("cli_writen: invalid NULL buff argument\n");
return (size_t)-1;
}
todo = count;
current = (const unsigned char *)buff;
do {
retval = write(fd, current, todo);
if (retval < 0) {
char err[128];
if (errno == EINTR) {
continue;
}
cli_errmsg("cli_writen: write error: %s\n", cli_strerror(errno, err, sizeof(err)));
return (size_t)-1;
}
if ((size_t)retval > todo) {
break;
} else {
todo -= retval;
}
current += retval;
} while (todo > 0);
return count;
}
int cli_filecopy(const char *src, const char *dest)
{
#ifdef _WIN32
return CopyFileA(src, dest, 0) ? 0 : -1;
#else
char *buffer;
int s, d;
size_t bytes;
if ((s = open(src, O_RDONLY | O_BINARY)) == -1)
return -1;
if ((d = open(dest, O_CREAT | O_WRONLY | O_TRUNC | O_BINARY, S_IRUSR | S_IWUSR)) == -1) {
close(s);
return -1;
}
if (!(buffer = cli_malloc(FILEBUFF))) {
close(s);
close(d);
return -1;
}
bytes = cli_readn(s, buffer, FILEBUFF);
while ((bytes != (size_t)-1) && (bytes != 0)) {
cli_writen(d, buffer, bytes);
bytes = cli_readn(s, buffer, FILEBUFF);
}
free(buffer);
close(s);
return close(d);
#endif
}
#ifndef P_tmpdir
#ifdef _WIN32
#define P_tmpdir "C:\\"
#else
#define P_tmpdir "/tmp"
#endif /* _WIN32 */
#endif /* P_tmpdir */
const char *cli_gettmpdir(void)
{
const char *tmpdir;
unsigned int i;
#ifdef _WIN32
char *envs[] = {"TEMP", "TMP", NULL};
#else
char *envs[] = {"TMPDIR", NULL};
#endif
for (i = 0; envs[i] != NULL; i++)
if ((tmpdir = getenv(envs[i])))
return tmpdir;
return P_tmpdir;
}
struct dirent_data {
char *filename;
const char *dirname;
STATBUF *statbuf;
long ino; /* -1: inode not available */
int is_dir; /* 0 - no, 1 - yes */
};
/* sort files before directories, and lower inodes before higher inodes */
static int ftw_compare(const void *a, const void *b)
{
const struct dirent_data *da = a;
const struct dirent_data *db = b;
long diff = da->is_dir - db->is_dir;
if (!diff) {
diff = da->ino - db->ino;
}
return diff;
}
enum filetype {
ft_unknown,
ft_link,
ft_directory,
ft_regular,
ft_skipped_special,
ft_skipped_link
};
static inline int ft_skipped(enum filetype ft)
{
return ft != ft_regular && ft != ft_directory;
}
#define FOLLOW_SYMLINK_MASK (CLI_FTW_FOLLOW_FILE_SYMLINK | CLI_FTW_FOLLOW_DIR_SYMLINK)
static int get_filetype(const char *fname, int flags, int need_stat,
STATBUF *statbuf, enum filetype *ft)
{
int stated = 0;
if (*ft == ft_unknown || *ft == ft_link) {
need_stat = 1;
if ((flags & FOLLOW_SYMLINK_MASK) != FOLLOW_SYMLINK_MASK) {
/* Following only one of directory/file symlinks, or none, may
* need to lstat.
* If we're following both file and directory symlinks, we don't need
* to lstat(), we can just stat() directly.*/
if (*ft != ft_link) {
/* need to lstat to determine if it is a symlink */
if (LSTAT(fname, statbuf) == -1)
return -1;
if (S_ISLNK(statbuf->st_mode)) {
*ft = ft_link;
} else {
/* It was not a symlink, stat() not needed */
need_stat = 0;
stated = 1;
}
}
if (*ft == ft_link && !(flags & FOLLOW_SYMLINK_MASK)) {
/* This is a symlink, but we don't follow any symlinks */
*ft = ft_skipped_link;
return 0;
}
}
}
if (need_stat) {
if (CLAMSTAT(fname, statbuf) == -1)
return -1;
stated = 1;
}
if (*ft == ft_unknown || *ft == ft_link) {
if (S_ISDIR(statbuf->st_mode) &&
(*ft != ft_link || (flags & CLI_FTW_FOLLOW_DIR_SYMLINK))) {
/* A directory, or (a symlink to a directory and we're following dir
* symlinks) */
*ft = ft_directory;
} else if (S_ISREG(statbuf->st_mode) &&
(*ft != ft_link || (flags & CLI_FTW_FOLLOW_FILE_SYMLINK))) {
/* A file, or (a symlink to a file and we're following file symlinks) */
*ft = ft_regular;
} else {
/* default: skipped */
*ft = S_ISLNK(statbuf->st_mode) ? ft_skipped_link : ft_skipped_special;
}
}
return stated;
}
/**
* @brief Determine the file type and pass the metadata to the callback as the "reason".
*
* The callback may end up doing something or doing nothing, depending on the reason.
*
* @param fname The file path
* @param flags CLI_FTW_* bitflag field
* @param statbuf [out] the stat metadata for the file.
* @param stated [out] 1 if statbuf contains stat info, 0 if not. -1 if there was a stat error.
* @param ft [out] will indicate if the file was skipped based on the file type.
* @param callback the callback (E.g. function that may scan the file)
* @param data callback data
* @return cl_error_t
*/
static cl_error_t handle_filetype(const char *fname, int flags,
STATBUF *statbuf, int *stated, enum filetype *ft,
cli_ftw_cb callback, struct cli_ftw_cbdata *data)
{
cl_error_t status = CL_EMEM;
*stated = get_filetype(fname, flags, flags & CLI_FTW_NEED_STAT, statbuf, ft);
if (*stated == -1) {
/* we failed a stat() or lstat() */
char *fname_copy = cli_strdup(fname);
if (NULL == fname_copy) {
goto done;
}
status = callback(NULL, fname_copy, fname, error_stat, data);
if (status != CL_SUCCESS) {
goto done;
}
*ft = ft_unknown;
} else if (*ft == ft_skipped_link || *ft == ft_skipped_special) {
/* skipped filetype */
char *fname_copy = cli_strdup(fname);
if (NULL == fname_copy) {
goto done;
}
status = callback(stated ? statbuf : NULL,
fname_copy,
fname,
*ft == ft_skipped_link ? warning_skipped_link : warning_skipped_special,
data);
if (status != CL_SUCCESS)
goto done;
}
status = CL_SUCCESS;
done:
return status;
}
static cl_error_t cli_ftw_dir(const char *dirname, int flags, int maxdepth, cli_ftw_cb callback, struct cli_ftw_cbdata *data, cli_ftw_pathchk pathchk);
static int handle_entry(struct dirent_data *entry, int flags, int maxdepth, cli_ftw_cb callback, struct cli_ftw_cbdata *data, cli_ftw_pathchk pathchk)
{
if (!entry->is_dir) {
return callback(entry->statbuf, entry->filename, entry->filename, visit_file, data);
} else {
return cli_ftw_dir(entry->dirname, flags, maxdepth, callback, data, pathchk);
}
}
cl_error_t cli_ftw(char *path, int flags, int maxdepth, cli_ftw_cb callback, struct cli_ftw_cbdata *data, cli_ftw_pathchk pathchk)
{
cl_error_t status = CL_EMEM;
STATBUF statbuf;
enum filetype ft = ft_unknown;
struct dirent_data entry = {0};
int stated = 0;
char *filename_for_callback = NULL;
char *filename_for_handleentry = NULL;
if (((flags & CLI_FTW_TRIM_SLASHES) || pathchk) && path[0] && path[1]) {
char *pathend;
/* trim slashes so that dir and dir/ behave the same when
* they are symlinks, and we are not following symlinks */
#ifndef _WIN32
while (path[0] == *PATHSEP && path[1] == *PATHSEP) path++;
#endif
pathend = path + strlen(path);
while (pathend > path && pathend[-1] == *PATHSEP) --pathend;
*pathend = '\0';
}
if (pathchk && pathchk(path, data) == 1) {
status = CL_SUCCESS;
goto done;
}
/* Determine if the file should be skipped (special file or symlink).
This will also get the stat metadata. */
status = handle_filetype(path, flags, &statbuf, &stated, &ft, callback, data);
if (status != CL_SUCCESS) {
goto done;
}
/* Bail out if the file should be skipped. */
if (ft_skipped(ft)) {
status = CL_SUCCESS;
goto done;
}
entry.statbuf = stated ? &statbuf : NULL;
entry.is_dir = ft == ft_directory;
/*
* handle_entry() doesn't call the callback for directories, so we'll call it now first.
*/
if (entry.is_dir) {
/* Allocate the filename for the callback function. TODO: this FTW code is spaghetti, refactor. */
filename_for_callback = cli_strdup(path);
if (NULL == filename_for_callback) {
goto done;
}
status = callback(entry.statbuf, filename_for_callback, path, visit_directory_toplev, data);
filename_for_callback = NULL; // free'd by the callback
if (status != CL_SUCCESS) {
goto done;
}
}
/*
* Now call handle_entry() to either call the callback for files,
* or recurse deeper into the file tree walk.
* TODO: Recursion is bad, this whole thing should be iterative
*/
if (entry.is_dir) {
entry.dirname = path;
} else {
/* Allocate the filename for the callback function within the handle_entry function. TODO: this FTW code is spaghetti, refactor. */
filename_for_handleentry = cli_strdup(path);
if (NULL == filename_for_handleentry) {
goto done;
}
entry.filename = filename_for_handleentry;
}
status = handle_entry(&entry, flags, maxdepth, callback, data, pathchk);
filename_for_handleentry = NULL; // free'd by the callback call in handle_entry()
done:
if (NULL != filename_for_callback) {
/* Free-check just in case someone injects additional calls and error handling before callback(). */
free(filename_for_callback);
}
if (NULL != filename_for_handleentry) {
/* Free-check just in case someone injects additional calls and error handling before handle_entry(). */
free(filename_for_handleentry);
}
return status;
}
static cl_error_t cli_ftw_dir(const char *dirname, int flags, int maxdepth, cli_ftw_cb callback, struct cli_ftw_cbdata *data, cli_ftw_pathchk pathchk)
{
DIR *dd;
struct dirent_data *entries = NULL;
size_t i, entries_cnt = 0;
cl_error_t ret;
if (maxdepth < 0) {
/* exceeded recursion limit */
ret = callback(NULL, NULL, dirname, warning_skipped_dir, data);
return ret;
}
if ((dd = opendir(dirname)) != NULL) {
struct dirent *dent;
errno = 0;
ret = CL_SUCCESS;
while ((dent = readdir(dd))) {
int stated = 0;
enum filetype ft;
char *fname;
STATBUF statbuf;
STATBUF *statbufp;
if (!strcmp(dent->d_name, ".") || !strcmp(dent->d_name, ".."))
continue;
#ifdef _DIRENT_HAVE_D_TYPE
switch (dent->d_type) {
case DT_DIR:
ft = ft_directory;
break;
case DT_LNK:
if (!(flags & FOLLOW_SYMLINK_MASK)) {
/* we don't follow symlinks, don't bother
* stating it */
errno = 0;
continue;
}
ft = ft_link;
break;
case DT_REG:
ft = ft_regular;
break;
case DT_UNKNOWN:
ft = ft_unknown;
break;
default:
ft = ft_skipped_special;
break;
}
#else
ft = ft_unknown;
#endif
fname = (char *)cli_malloc(strlen(dirname) + strlen(dent->d_name) + 2);
if (!fname) {
ret = callback(NULL, NULL, dirname, error_mem, data);
if (ret != CL_SUCCESS)
break;
continue; /* have to skip this one if continuing after error */
}
if (!strcmp(dirname, PATHSEP))
sprintf(fname, PATHSEP "%s", dent->d_name);
else
sprintf(fname, "%s" PATHSEP "%s", dirname, dent->d_name);
if (pathchk && pathchk(fname, data) == 1) {
free(fname);
continue;
}
ret = handle_filetype(fname, flags, &statbuf, &stated, &ft, callback, data);
if (ret != CL_SUCCESS) {
free(fname);
break;
}
if (ft_skipped(ft)) { /* skip */
free(fname);
errno = 0;
continue;
}
if (stated && (flags & CLI_FTW_NEED_STAT)) {
statbufp = cli_malloc(sizeof(*statbufp));
if (!statbufp) {
ret = callback(stated ? &statbuf : NULL, NULL, fname, error_mem, data);
free(fname);
if (ret != CL_SUCCESS)
break;
else {
errno = 0;
continue;
}
}
memcpy(statbufp, &statbuf, sizeof(statbuf));
} else {
statbufp = 0;
}
entries_cnt++;
entries = cli_realloc(entries, entries_cnt * sizeof(*entries));
if (!entries) {
ret = callback(stated ? &statbuf : NULL, NULL, fname, error_mem, data);
free(fname);
if (statbufp)
free(statbufp);
break;
} else {
struct dirent_data *entry = &entries[entries_cnt - 1];
entry->filename = fname;
entry->statbuf = statbufp;
entry->is_dir = ft == ft_directory;
entry->dirname = entry->is_dir ? fname : NULL;
#ifdef _XOPEN_UNIX
entry->ino = dent->d_ino;
#else
entry->ino = -1;
#endif
}
errno = 0;
}
closedir(dd);
ret = CL_SUCCESS;
if (entries) {
cli_qsort(entries, entries_cnt, sizeof(*entries), ftw_compare);
for (i = 0; i < entries_cnt; i++) {
struct dirent_data *entry = &entries[i];
ret = handle_entry(entry, flags, maxdepth - 1, callback, data, pathchk);
if (entry->is_dir)
free(entry->filename);
if (entry->statbuf)
free(entry->statbuf);
if (ret != CL_SUCCESS) {
/* Something went horribly wrong, Skip the rest of the files */
cli_errmsg("File tree walk aborted.\n");
break;
}
}
for (i++; i < entries_cnt; i++) {
struct dirent_data *entry = &entries[i];
free(entry->filename);
free(entry->statbuf);
}
free(entries);
}
} else {
ret = callback(NULL, NULL, dirname, error_stat, data);
}
return ret;
}
/* strerror_r is not available everywhere, (and when it is there are two variants,
* the XSI, and the GNU one, so provide a wrapper to make sure correct one is
* used */
const char *cli_strerror(int errnum, char *buf, size_t len)
{
char *err;
#ifdef CL_THREAD_SAFE
pthread_mutex_lock(&cli_strerror_mutex);
#endif
err = strerror(errnum);
strncpy(buf, err, len);
buf[len - 1] = '\0'; /* just in case */
#ifdef CL_THREAD_SAFE
pthread_mutex_unlock(&cli_strerror_mutex);
#endif
return buf;
}
static char *cli_md5buff(const unsigned char *buffer, unsigned int len, unsigned char *dig)
{
unsigned char digest[16];
char *md5str, *pt;
int i;
cl_hash_data("md5", buffer, len, digest, NULL);
if (dig)
memcpy(dig, digest, 16);
if (!(md5str = (char *)cli_calloc(32 + 1, sizeof(char))))
return NULL;
pt = md5str;
for (i = 0; i < 16; i++) {
sprintf(pt, "%02x", digest[i]);
pt += 2;
}
return md5str;
}
unsigned int cli_rndnum(unsigned int max)
{
if (name_salt[0] == 16) { /* minimizes re-seeding after the first call to cli_gentemp() */
struct timeval tv;
gettimeofday(&tv, (struct timezone *)0);
srand(tv.tv_usec + clock() + rand());
}
return 1 + (unsigned int)(max * (rand() / (1.0 + RAND_MAX)));
}
char *cli_sanitize_filepath(const char *filepath, size_t filepath_len, char **sanitized_filebase)
{
uint32_t depth = 0;
size_t index = 0;
size_t sanitized_index = 0;
char *sanitized_filepath = NULL;
if ((NULL == filepath) || (0 == filepath_len) || (PATH_MAX < filepath_len)) {
goto done;
}
if (NULL != sanitized_filebase) {
*sanitized_filebase = NULL;
}
sanitized_filepath = cli_calloc(filepath_len + 1, sizeof(unsigned char));
if (NULL == sanitized_filepath) {
cli_dbgmsg("cli_sanitize_filepath: out of memory\n");
goto done;
}
while (index < filepath_len) {
char *next_pathsep = NULL;
if (0 == strncmp(filepath + index, PATHSEP, strlen(PATHSEP))) {
/*
* Is "/" (or "\\" on Windows)
*/
/* Skip leading pathsep in absolute path, or extra pathsep) */
index += strlen(PATHSEP);
continue;
} else if (0 == strncmp(filepath + index, "." PATHSEP, strlen("." PATHSEP))) {
/*
* Is "./" (or ".\\" on Windows)
*/
/* Current directory indicator is meaningless and should not add to the depth. Skip it. */
index += strlen("." PATHSEP);
continue;
} else if (0 == strncmp(filepath + index, ".." PATHSEP, strlen(".." PATHSEP))) {
/*
* Is "../" (or "..\\" on Windows)
*/
if (depth == 0) {
/* Relative path would traverse parent directory. Skip it. */
index += strlen(".." PATHSEP);
continue;
} else {
/* Relative path is safe. Allow it. */
strncpy(sanitized_filepath + sanitized_index, filepath + index, strlen(".." PATHSEP));
sanitized_index += strlen(".." PATHSEP);
index += strlen(".." PATHSEP);
depth--;
}
#ifdef _WIN32
/*
* Windows' POSIX style API's accept both "/" and "\\" style path separators.
* The following checks using POSIX style path separators on Windows.
*/
} else if (0 == strncmp(filepath + index, "/", strlen("/"))) {
/*
* Is "/".
*/
/* Skip leading pathsep in absolute path, or extra pathsep) */
index += strlen("/");
continue;
} else if (0 == strncmp(filepath + index, "./", strlen("./"))) {
/*
* Is "./"
*/
/* Current directory indicator is meaningless and should not add to the depth. Skip it. */
index += strlen("./");
continue;
} else if (0 == strncmp(filepath + index, "../", strlen("../"))) {
/*
* Is "../"
*/
if (depth == 0) {
/* Relative path would traverse parent directory. Skip it. */
index += strlen("../");
continue;
} else {
/* Relative path is safe. Allow it. */
strncpy(sanitized_filepath + sanitized_index, filepath + index, strlen("../"));
sanitized_index += strlen("../");
index += strlen("../");
depth--;
/* Convert path separator to Windows separator */
sanitized_filepath[sanitized_index - 1] = '\\';
}
#endif
} else {
/*
* Is not "/", "./", or "../".
*/
/* Find the next path separator. */
#ifdef _WIN32
char *next_windows_pathsep = NULL;
#endif
next_pathsep = CLI_STRNSTR(filepath + index, "/", filepath_len - index);
#ifdef _WIN32
/* Check for both types of separators. */
next_windows_pathsep = CLI_STRNSTR(filepath + index, "\\", filepath_len - index);
if (NULL != next_windows_pathsep) {
if ((NULL == next_pathsep) || (next_windows_pathsep < next_pathsep)) {
next_pathsep = next_windows_pathsep;
}
}
#endif
if (NULL == next_pathsep) {
/* No more path separators, copy the rest (filename) into the sanitized path */
strncpy(sanitized_filepath + sanitized_index, filepath + index, filepath_len - index);
if (NULL != sanitized_filebase) {
/* Set output variable to point to the file base name */
*sanitized_filebase = sanitized_filepath + sanitized_index;
}
break;
}
next_pathsep += strlen(PATHSEP); /* Include the path separator in the copy */
/* Copy next directory name into the sanitized path */
strncpy(sanitized_filepath + sanitized_index, filepath + index, next_pathsep - (filepath + index));
sanitized_index += next_pathsep - (filepath + index);
index += next_pathsep - (filepath + index);
depth++;
#ifdef _WIN32
/* Convert path separator to Windows separator */
sanitized_filepath[sanitized_index - 1] = '\\';
#endif
}
}
done:
if ((NULL != sanitized_filepath) && (0 == strlen(sanitized_filepath))) {
free(sanitized_filepath);
sanitized_filepath = NULL;
if (NULL != sanitized_filebase) {
*sanitized_filebase = NULL;
}
}
return sanitized_filepath;
}
#define SHORT_HASH_LENGTH 10
char *cli_genfname(const char *prefix)
{
char *sanitized_prefix = NULL;
char *sanitized_prefix_base = NULL;
char *fname = NULL;
unsigned char salt[16 + 32];
char *tmp;
int i;
size_t len;
if (prefix && (strlen(prefix) > 0)) {
sanitized_prefix = cli_sanitize_filepath(prefix, strlen(prefix), &sanitized_prefix_base);
}
if (NULL != sanitized_prefix_base) {
len = strlen(sanitized_prefix_base) + strlen(".") + SHORT_HASH_LENGTH + 1; /* {prefix}.{SHORT_HASH_LENGTH}\0 */
} else {
len = strlen("clamav-") + 48 + strlen(".tmp") + 1; /* clamav-{48}.tmp\0 */
}
fname = (char *)cli_calloc(len, sizeof(char));
if (!fname) {
cli_dbgmsg("cli_genfname: out of memory\n");
return NULL;
}
#ifdef CL_THREAD_SAFE
pthread_mutex_lock(&cli_gentemp_mutex);
#endif
memcpy(salt, name_salt, 16);
for (i = 16; i < 48; i++)
salt[i] = cli_rndnum(255);
tmp = cli_md5buff(salt, 48, name_salt);
#ifdef CL_THREAD_SAFE
pthread_mutex_unlock(&cli_gentemp_mutex);
#endif
if (NULL == tmp) {
free(fname);
cli_dbgmsg("cli_genfname: out of memory\n");
return NULL;
}
if (NULL != sanitized_prefix_base) {
snprintf(fname, len, "%s.%.*s", sanitized_prefix_base, SHORT_HASH_LENGTH, tmp);
} else {
snprintf(fname, len, "clamav-%s.tmp", tmp);
}
if (NULL != sanitized_prefix) {
free(sanitized_prefix);
}
free(tmp);
return (fname);
}
char *cli_newfilepath(const char *dir, const char *fname)
{
char *fullpath;
const char *mdir;
size_t len;
mdir = dir ? dir : cli_gettmpdir();
if (!fname) {
cli_dbgmsg("cli_newfilepath('%s'): out of memory\n", mdir);
return NULL;
}
len = strlen(mdir) + strlen(PATHSEP) + strlen(fname) + 1; /* mdir/fname\0 */
fullpath = (char *)cli_calloc(len, sizeof(char));
if (!fullpath) {
cli_dbgmsg("cli_newfilepath('%s'): out of memory\n", mdir);
return NULL;
}
snprintf(fullpath, len, "%s" PATHSEP "%s", mdir, fname);
return (fullpath);
}
cl_error_t cli_newfilepathfd(const char *dir, char *fname, char **name, int *fd)
{
*name = cli_newfilepath(dir, fname);
if (!*name)
return CL_EMEM;
*fd = open(*name, O_RDWR | O_CREAT | O_TRUNC | O_BINARY | O_EXCL, S_IRUSR | S_IWUSR);
/*
* EEXIST is almost impossible to occur, so we just treat it as other
* errors
*/
if (*fd == -1) {
cli_errmsg("cli_newfilepathfd: Can't create file %s: %s\n", *name, strerror(errno));
free(*name);
*name = NULL;
return CL_ECREAT;
}
return CL_SUCCESS;
}
char *cli_gentemp_with_prefix(const char *dir, const char *prefix)
{
char *fname;
char *fullpath;
const char *mdir;
size_t len;
mdir = dir ? dir : cli_gettmpdir();
fname = cli_genfname(prefix);
if (!fname) {
cli_dbgmsg("cli_gentemp_with_prefix('%s'): out of memory\n", mdir);
return NULL;
}
len = strlen(mdir) + strlen(PATHSEP) + strlen(fname) + 1; /* mdir/fname\0 */
fullpath = (char *)cli_calloc(len, sizeof(char));
if (!fullpath) {
free(fname);
cli_dbgmsg("cli_gentemp_with_prefix('%s'): out of memory\n", mdir);
return NULL;
}
snprintf(fullpath, len, "%s" PATHSEP "%s", mdir, fname);
free(fname);
return (fullpath);
}
char *cli_gentemp(const char *dir)
{
return cli_gentemp_with_prefix(dir, NULL);
}
cl_error_t cli_gentempfd(const char *dir, char **name, int *fd)
{
return cli_gentempfd_with_prefix(dir, NULL, name, fd);
}
cl_error_t cli_gentempfd_with_prefix(const char *dir, char *prefix, char **name, int *fd)
{
*name = cli_gentemp_with_prefix(dir, prefix);
if (!*name)
return CL_EMEM;
*fd = open(*name, O_RDWR | O_CREAT | O_TRUNC | O_BINARY | O_EXCL, S_IRUSR | S_IWUSR);
/*
* EEXIST is almost impossible to occur, so we just treat it as other
* errors
*/
if (*fd == -1) {
if ((EILSEQ == errno) || (EINVAL == errno) || (ENAMETOOLONG == errno)) {
cli_dbgmsg("cli_gentempfd_with_prefix: Can't create temp file using prefix. Using a randomly generated name instead.\n");
free(*name);
*name = cli_gentemp(dir);
if (!*name)
return CL_EMEM;
*fd = open(*name, O_RDWR | O_CREAT | O_TRUNC | O_BINARY | O_EXCL, S_IRUSR | S_IWUSR);
if (*fd == -1) {
cli_errmsg("cli_gentempfd_with_prefix: Can't create temporary file %s: %s\n", *name, strerror(errno));
free(*name);
*name = NULL;
return CL_ECREAT;
}
} else {
cli_errmsg("cli_gentempfd_with_prefix: Can't create temporary file %s: %s\n", *name, strerror(errno));
free(*name);
*name = NULL;
return CL_ECREAT;
}
}
return CL_SUCCESS;
}
int cli_regcomp(regex_t *preg, const char *pattern, int cflags)
{
if (!strncmp(pattern, "(?i)", 4)) {
pattern += 4;
cflags |= REG_ICASE;
}
return cli_regcomp_real(preg, pattern, cflags);
}
cl_error_t cli_get_filepath_from_filedesc(int desc, char **filepath)
{
cl_error_t status = CL_EARG;
char *evaluated_filepath = NULL;
#ifdef __linux__
char fname[PATH_MAX];
char link[32];
ssize_t linksz;
memset(&fname, 0, PATH_MAX);
if (NULL == filepath) {
cli_errmsg("cli_get_filepath_from_filedesc: Invalid args.\n");
goto done;
}
snprintf(link, sizeof(link), "/proc/self/fd/%u", desc);
link[sizeof(link) - 1] = '\0';
if (-1 == (linksz = readlink(link, fname, PATH_MAX - 1))) {
cli_dbgmsg("cli_get_filepath_from_filedesc: Failed to resolve filename for descriptor %d (%s)\n", desc, link);
status = CL_EOPEN;
goto done;
}
/* Success. Add null terminator */
fname[linksz] = '\0';
evaluated_filepath = CLI_STRNDUP(fname, CLI_STRNLEN(fname, PATH_MAX));
if (NULL == evaluated_filepath) {
cli_errmsg("cli_get_filepath_from_filedesc: Failed to allocate memory to store filename\n");
status = CL_EMEM;
goto done;
}
#elif __APPLE__
char fname[PATH_MAX];
memset(&fname, 0, PATH_MAX);
if (NULL == filepath) {
cli_errmsg("cli_get_filepath_from_filedesc: Invalid args.\n");
goto done;
}
if (fcntl(desc, F_GETPATH, &fname) < 0) {
cli_dbgmsg("cli_get_filepath_from_filedesc: Failed to resolve filename for descriptor %d\n", desc);
status = CL_EOPEN;
goto done;
}
evaluated_filepath = CLI_STRNDUP(fname, CLI_STRNLEN(fname, PATH_MAX));
if (NULL == evaluated_filepath) {
cli_errmsg("cli_get_filepath_from_filedesc: Failed to allocate memory to store filename\n");
status = CL_EMEM;
goto done;
}
#elif _WIN32
DWORD dwRet = 0;
intptr_t hFile = _get_osfhandle(desc);
WCHAR *long_evaluated_filepathW = NULL;
char *long_evaluated_filepathA = NULL;
size_t evaluated_filepath_len = 0;
cl_error_t conv_result;
if (NULL == filepath) {
cli_errmsg("cli_get_filepath_from_filedesc: Invalid args.\n");
goto done;
}
dwRet = GetFinalPathNameByHandleW((HANDLE)hFile, NULL, 0, VOLUME_NAME_DOS);
if (dwRet == 0) {
cli_dbgmsg("cli_get_filepath_from_filedesc: Failed to resolve filename for descriptor %d\n", desc);
status = CL_EOPEN;
goto done;
}
long_evaluated_filepathW = calloc(dwRet + 1, sizeof(WCHAR));
if (NULL == long_evaluated_filepathW) {
cli_errmsg("cli_get_filepath_from_filedesc: Failed to allocate %u bytes to store filename\n", dwRet + 1);
status = CL_EMEM;
goto done;
}
dwRet = GetFinalPathNameByHandleW((HANDLE)hFile, long_evaluated_filepathW, dwRet + 1, VOLUME_NAME_DOS);
if (dwRet == 0) {
cli_dbgmsg("cli_get_filepath_from_filedesc: Failed to resolve filename for descriptor %d\n", desc);
status = CL_EOPEN;
goto done;
}
if (0 == wcsncmp(L"\\\\?\\UNC", long_evaluated_filepathW, wcslen(L"\\\\?\\UNC"))) {
conv_result = cli_codepage_to_utf8(
long_evaluated_filepathW,
(wcslen(long_evaluated_filepathW)) * sizeof(WCHAR),
CODEPAGE_UTF16_LE,
&evaluated_filepath,
&evaluated_filepath_len);
if (CL_SUCCESS != conv_result) {
cli_errmsg("cli_get_filepath_from_filedesc: Failed to convert UTF16_LE filename to UTF8\n", dwRet + 1);
status = CL_EOPEN;
goto done;
}
} else {
conv_result = cli_codepage_to_utf8(
long_evaluated_filepathW + wcslen(L"\\\\?\\"),
(wcslen(long_evaluated_filepathW) - wcslen(L"\\\\?\\")) * sizeof(WCHAR),
CODEPAGE_UTF16_LE,
&evaluated_filepath,
&evaluated_filepath_len);
if (CL_SUCCESS != conv_result) {
cli_errmsg("cli_get_filepath_from_filedesc: Failed to convert UTF16_LE filename to UTF8\n", dwRet + 1);
status = CL_EOPEN;
goto done;
}
}
#else
cli_dbgmsg("cli_get_filepath_from_filedesc: No mechanism implemented to determine filename from file descriptor.\n");
status = CL_BREAK;
goto done;
#endif
cli_dbgmsg("cli_get_filepath_from_filedesc: File path for fd [%d] is: %s\n", desc, evaluated_filepath);
status = CL_SUCCESS;
*filepath = evaluated_filepath;
done:
#ifdef _WIN32
if (NULL != long_evaluated_filepathW) {
free(long_evaluated_filepathW);
}
#endif
return status;
}
cl_error_t cli_realpath(const char *file_name, char **real_filename)
{
char *real_file_path = NULL;
cl_error_t status = CL_EARG;
#ifdef _WIN32
int desc = -1;
#endif
cli_dbgmsg("Checking realpath of %s\n", file_name);
if (NULL == file_name || NULL == real_filename) {
cli_warnmsg("cli_realpath: Invalid arguments.\n");
goto done;
}
#ifndef _WIN32
real_file_path = realpath(file_name, NULL);
if (NULL == real_file_path) {
status = CL_EMEM;
goto done;
}
status = CL_SUCCESS;
#else
if ((desc = safe_open(file_name, O_RDONLY | O_BINARY)) == -1) {
cli_warnmsg("Can't open file %s: %s\n", file_name, strerror(errno));
status = CL_EOPEN;
goto done;
}
status = cli_get_filepath_from_filedesc(desc, &real_file_path);
#endif
*real_filename = real_file_path;
done:
#ifdef _WIN32
if (-1 != desc) {
close(desc);
}
#endif
return status;
}