ClamAV is an open source (GPLv2) anti-virus toolkit.
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clamav/clamd/scanner.c

633 lines
16 KiB

/*
* Copyright (C) 2002 - 2007 Tomasz Kojm <tkojm@clamav.net>
* MULTISCAN code (C) 2006 Sensory Networks, Inc.
* Written by Tomasz Kojm
*
* 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.
*/
#ifdef _MSC_VER
#include <winsock.h>
#endif
#if HAVE_CONFIG_H
#include "clamav-config.h"
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include <errno.h>
#include <sys/stat.h>
#include <sys/types.h>
#ifndef C_WINDOWS
#include <sys/time.h>
#include <sys/wait.h>
#include <sys/param.h>
#include <signal.h>
#include <dirent.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#endif
#include <pthread.h>
#if defined(HAVE_READDIR_R_3) || defined(HAVE_READDIR_R_2)
#include <limits.h>
#include <stddef.h>
#endif
#include "libclamav/clamav.h"
#include "libclamav/others.h"
#include "shared/optparser.h"
#include "shared/output.h"
#include "shared/misc.h"
#include "others.h"
#include "scanner.h"
#include "shared.h"
#include "network.h"
#include "thrmgr.h"
#ifdef C_LINUX
dev_t procdev; /* /proc device */
#endif
extern int progexit;
#ifndef C_WINDOWS
#define closesocket(s) close(s)
#endif
struct multi_tag {
int sd;
unsigned int options;
const struct optstruct *opts;
char *fname;
const struct cl_engine *engine;
};
static int checksymlink(const char *path)
{
struct stat statbuf;
if(stat(path, &statbuf) == -1)
return -1;
if(S_ISDIR(statbuf.st_mode))
return 1;
if(S_ISREG(statbuf.st_mode))
return 2;
return 0;
}
static int dirscan(const char *dirname, const char *term, const char **virname, unsigned long int *scanned, const struct cl_engine *engine, unsigned int options, const struct optstruct *opts, int odesc, unsigned int *reclev, unsigned int type, threadpool_t *multi_pool)
{
DIR *dd;
struct dirent *dent;
#if defined(HAVE_READDIR_R_3) || defined(HAVE_READDIR_R_2)
union {
struct dirent d;
char b[offsetof(struct dirent, d_name) + NAME_MAX + 1];
} result;
#endif
struct stat statbuf;
char *fname;
int ret = 0, scanret = 0;
unsigned int maxdirrec = 0;
struct multi_tag *scandata;
const struct optstruct *opt;
if((opt = optget(opts, "ExcludePath"))->enabled) {
while(opt) {
if(match_regex(dirname, opt->strarg) == 1) {
mdprintf(odesc, "%s: Excluded%c", dirname, term);
return 0;
}
opt = (struct optstruct *) opt->nextarg;
}
}
maxdirrec = optget(opts, "MaxDirectoryRecursion")->numarg;
if(maxdirrec) {
if(*reclev > maxdirrec) {
logg("*Directory recursion limit exceeded at %s\n", dirname);
return 0;
}
(*reclev)++;
}
if((dd = opendir(dirname)) != NULL) {
#ifdef HAVE_READDIR_R_3
while(!readdir_r(dd, &result.d, &dent) && dent) {
#elif defined(HAVE_READDIR_R_2)
while((dent = (struct dirent *) readdir_r(dd, &result.d))) {
#else
while((dent = readdir(dd))) {
#endif
if (!is_fd_connected(odesc)) {
logg("Client disconnected\n");
closedir(dd);
return 1;
}
if(progexit) {
closedir(dd);
return 1;
}
#if (!defined(C_INTERIX)) && (!defined(C_WINDOWS))
if(dent->d_ino)
#endif
{
if(strcmp(dent->d_name, ".") && strcmp(dent->d_name, "..")) {
/* build the full name */
fname = (char *) malloc(strlen(dirname) + strlen(dent->d_name) + 2);
if(!fname) {
logg("!Can't allocate memory for fname\n");
closedir(dd);
return -2;
}
sprintf(fname, "%s/%s", dirname, dent->d_name);
/* stat the file */
if(lstat(fname, &statbuf) != -1) {
if((S_ISDIR(statbuf.st_mode) && !S_ISLNK(statbuf.st_mode)) || (S_ISLNK(statbuf.st_mode) && (checksymlink(fname) == 1) && optget(opts, "FollowDirectorySymlinks")->enabled)) {
if(dirscan(fname, term, virname, scanned, engine, options, opts, odesc, reclev, type, multi_pool) == 1) {
free(fname);
closedir(dd);
return 1;
}
free(fname);
} else {
if(S_ISREG(statbuf.st_mode) || (S_ISLNK(statbuf.st_mode) && (checksymlink(fname) == 2) && optget(opts, "FollowFileSymlinks")->enabled)) {
#ifdef C_LINUX
if(procdev && (statbuf.st_dev == procdev))
free(fname);
else
#endif
{
if(type == TYPE_MULTISCAN) {
scandata = (struct multi_tag *) malloc(sizeof(struct multi_tag));
if(!scandata) {
logg("!Can't allocate memory for scandata\n");
free(fname);
closedir(dd);
return -2;
}
scandata->sd = odesc;
scandata->options = options;
scandata->opts = opts;
scandata->fname = fname;
scandata->engine = engine;
if(!thrmgr_dispatch(multi_pool, scandata)) {
logg("!thread dispatch failed for multi_pool (file %s)\n", fname);
mdprintf(odesc, "ERROR: Can't scan file %s%c", fname, term);
free(fname);
free(scandata);
closedir(dd);
return 1;
}
pthread_mutex_lock(&multi_pool->pool_mutex);
while(!multi_pool->thr_idle) /* non-critical */ {
pthread_cond_wait(&multi_pool->idle_cond, &multi_pool->pool_mutex);
}
pthread_mutex_unlock(&multi_pool->pool_mutex);
} else { /* CONTSCAN, SCAN */
thrmgr_setactivetask(fname, NULL);
scanret = cl_scanfile(fname, virname, scanned, engine, options);
thrmgr_setactivetask(NULL, NULL);
if(scanret == CL_VIRUS) {
mdprintf(odesc, "%s: %s FOUND%c", fname, *virname, term);
logg("~%s: %s FOUND\n", fname, *virname);
virusaction(fname, *virname, opts);
if(type == TYPE_SCAN) {
closedir(dd);
free(fname);
return 1;
} else /* CONTSCAN */
ret = 2;
} else if(scanret != CL_CLEAN) {
mdprintf(odesc, "%s: %s ERROR%c", fname, cl_strerror(scanret), term);
logg("~%s: %s ERROR\n", fname, cl_strerror(scanret));
if(scanret == CL_EMEM) {
closedir(dd);
free(fname);
return -2;
}
} else if(logok) {
logg("~%s: OK\n", fname);
}
free(fname);
}
}
} else {
free(fname);
}
}
} else {
logg("^lstat failed on %s: %s\n", fname, strerror(errno));
free(fname);
}
}
}
}
closedir(dd);
} else {
return -1;
}
(*reclev)--;
return ret;
}
static void multiscanfile(void *arg)
{
struct multi_tag *tag = (struct multi_tag *) arg;
const char *virname;
#ifndef C_WINDOWS
sigset_t sigset;
#endif
int ret;
#ifndef C_WINDOWS
/* ignore all signals */
sigfillset(&sigset);
pthread_sigmask(SIG_SETMASK, &sigset, NULL);
#endif
thrmgr_setactivetask(tag->fname, "MULTISCANFILE");
ret = cl_scanfile(tag->fname, &virname, NULL, tag->engine, tag->options);
thrmgr_setactivetask(NULL, NULL);
if(ret == CL_VIRUS) {
mdprintf(tag->sd, "%s: %s FOUND\n", tag->fname, virname);
logg("~%s: %s FOUND\n", tag->fname, virname);
virusaction(tag->fname, virname, tag->opts);
} else if(ret != CL_CLEAN) {
mdprintf(tag->sd, "%s: %s ERROR\n", tag->fname, cl_strerror(ret));
logg("~%s: %s ERROR\n", tag->fname, cl_strerror(ret));
} else if(logok) {
logg("~%s: OK\n", tag->fname);
}
free(tag->fname);
free(tag);
return;
}
int scan(const char *filename, const char term, unsigned long int *scanned, const struct cl_engine *engine, unsigned int options, const struct optstruct *opts, int odesc, unsigned int type)
{
struct stat sb;
int ret = 0;
unsigned int reclev = 0;
const char *virname;
const struct optstruct *opt;
threadpool_t *multi_pool = NULL;
/* stat file */
if(lstat(filename, &sb) == -1) {
mdprintf(odesc, "%s: lstat() failed. ERROR%c", filename, term);
return -1;
}
/* check permissions */
if(access(filename, R_OK)) {
mdprintf(odesc, "%s: Access denied. ERROR%c", filename, term);
return -1;
}
if((opt = optget(opts, "ExcludePath"))->enabled) {
if(match_regex(filename, opt->strarg) == 1) {
mdprintf(odesc, "%s: Excluded%c", filename, term);
return 0;
}
}
switch(sb.st_mode & S_IFMT) {
#ifdef S_IFLNK
case S_IFLNK:
if(!optget(opts, "FollowFileSymlinks")->enabled)
break;
/* else go to the next case */
#endif
case S_IFREG:
if(sb.st_size == 0) { /* empty file */
mdprintf(odesc, "%s: Empty file%c", filename, term);
return 0;
}
#ifdef C_LINUX
if(procdev && (sb.st_dev == procdev))
ret = CL_CLEAN;
else
#endif
{
thrmgr_setactivetask(filename, NULL);
ret = cl_scanfile(filename, &virname, scanned, engine, options);
thrmgr_setactivetask(NULL, NULL);
}
if(ret == CL_VIRUS) {
mdprintf(odesc, "%s: %s FOUND%c", filename, virname, term);
logg("~%s: %s FOUND\n", filename, virname);
virusaction(filename, virname, opts);
} else if(ret != CL_CLEAN) {
mdprintf(odesc, "%s: %s ERROR%c", filename, cl_strerror(ret), term);
logg("~%s: %s ERROR\n", filename, cl_strerror(ret));
if(ret == CL_EMEM)
return -2;
} else if (logok) {
logg("~%s: OK\n", filename);
}
break;
case S_IFDIR:
if(type == TYPE_MULTISCAN) {
int idletimeout = optget(opts, "IdleTimeout")->numarg;
int max_threads = optget(opts, "MaxThreads")->numarg;
if((multi_pool = thrmgr_new(max_threads, idletimeout, multiscanfile)) == NULL) {
logg("!thrmgr_new failed for multi_pool\n");
mdprintf(odesc, "thrmgr_new failed for multi_pool ERROR%c", term);
return -1;
}
}
ret = dirscan(filename, term, &virname, scanned, engine, options, opts, odesc, &reclev, type, multi_pool);
if(multi_pool)
thrmgr_destroy(multi_pool);
break;
default:
mdprintf(odesc, "%s: Not supported file type. ERROR%c", filename, term);
return -1;
}
if(!ret)
mdprintf(odesc, "%s: OK%c", filename, term);
return ret;
}
/*
* This function was readded by mbalmer@openbsd.org. That is the reason
* why it is so nicely formatted.
*/
int scanfd(const int fd, unsigned long int *scanned,
const struct cl_engine *engine,
unsigned int options, const struct optstruct *opts, int odesc)
{
int ret;
const char *virname;
struct stat statbuf;
char fdstr[32];
if(fstat(fd, &statbuf) == -1)
return -1;
if(!S_ISREG(statbuf.st_mode))
return -1;
snprintf(fdstr, sizeof(fdstr), "fd[%d]", fd);
thrmgr_setactivetask(fdstr, NULL);
ret = cl_scandesc(fd, &virname, scanned, engine, options);
thrmgr_setactivetask(NULL, NULL);
if(ret == CL_VIRUS) {
mdprintf(odesc, "%s: %s FOUND\n", fdstr, virname);
logg("%s: %s FOUND\n", fdstr, virname);
virusaction(fdstr, virname, opts);
} else if(ret != CL_CLEAN) {
mdprintf(odesc, "%s: %s ERROR\n", fdstr, cl_strerror(ret));
logg("%s: %s ERROR\n", fdstr, cl_strerror(ret));
} else {
mdprintf(odesc, "%s: OK\n", fdstr);
if(logok)
logg("%s: OK\n", fdstr);
}
return ret;
}
int scanstream(int odesc, unsigned long int *scanned, const struct cl_engine *engine, unsigned int options, const struct optstruct *opts)
{
int ret, sockfd, acceptd;
int tmpd, bread, retval, timeout, btread;
unsigned int port = 0, portscan = 1000, min_port, max_port;
unsigned long int size = 0, maxsize = 0;
short bound = 0, rnd_port_first = 1;
const char *virname;
char buff[FILEBUFF];
char peer_addr[32];
struct sockaddr_in server;
struct sockaddr_in peer;
socklen_t addrlen;
struct hostent he;
const struct optstruct *opt;
char *tmpname;
/* get min port */
min_port = optget(opts, "StreamMinPort")->numarg;
if(min_port < 1024 || min_port > 65535)
min_port = 1024;
/* get max port */
max_port = optget(opts, "StreamMaxPort")->numarg;
if(max_port < min_port || max_port > 65535)
max_port = 65535;
/* bind to a free port */
while(!bound && --portscan) {
if(rnd_port_first) {
/* try a random port first */
port = min_port + cli_rndnum(max_port - min_port);
rnd_port_first = 0;
} else {
/* try the neighbor ports */
if(--port < min_port)
port=max_port;
}
memset((char *) &server, 0, sizeof(server));
server.sin_family = AF_INET;
server.sin_port = htons(port);
if((opt = optget(opts, "TCPAddr"))->enabled) {
if(r_gethostbyname(opt->strarg, &he, buff, sizeof(buff)) == -1) {
logg("!r_gethostbyname(%s) error: %s\n", opt->strarg, strerror(errno));
mdprintf(odesc, "r_gethostbyname(%s) ERROR\n", opt->strarg);
return -1;
}
server.sin_addr = *(struct in_addr *) he.h_addr_list[0];
} else
server.sin_addr.s_addr = INADDR_ANY;
if((sockfd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
continue;
if(bind(sockfd, (struct sockaddr *) &server, sizeof(struct sockaddr_in)) == -1)
closesocket(sockfd);
else
bound = 1;
}
timeout = optget(opts, "ReadTimeout")->numarg;
if(timeout == 0)
timeout = -1;
if(!bound && !portscan) {
logg("!ScanStream: Can't find any free port.\n");
mdprintf(odesc, "Can't find any free port. ERROR\n");
closesocket(sockfd);
return -1;
} else {
listen(sockfd, 1);
if(mdprintf(odesc, "PORT %u\n", port) <= 0) {
logg("!ScanStream: error transmitting port.\n");
closesocket(sockfd);
return -1;
}
}
switch(retval = poll_fd(sockfd, timeout, 0)) {
case 0: /* timeout */
mdprintf(odesc, "Accept timeout. ERROR\n");
logg("!ScanStream %u: accept timeout.\n", port);
closesocket(sockfd);
return -1;
case -1:
mdprintf(odesc, "Accept poll. ERROR\n");
logg("!ScanStream %u: accept poll failed.\n", port);
closesocket(sockfd);
return -1;
}
addrlen = sizeof(peer);
if((acceptd = accept(sockfd, (struct sockaddr *) &peer, &addrlen)) == -1) {
closesocket(sockfd);
mdprintf(odesc, "accept() ERROR\n");
logg("!ScanStream %u: accept() failed.\n", port);
return -1;
}
snprintf(peer_addr, sizeof(peer_addr), "%s", inet_ntoa(peer.sin_addr));
logg("*Accepted connection from %s on port %u, fd %d\n", peer_addr, port, acceptd);
if(cli_gentempfd(optget(opts, "TemporaryDirectory")->strarg, &tmpname, &tmpd)) {
shutdown(sockfd, 2);
closesocket(sockfd);
closesocket(acceptd);
mdprintf(odesc, "cli_gentempfd() failed. ERROR\n");
logg("!ScanStream(%s@%u): Can't create temporary file.\n", peer_addr, port);
return -1;
}
maxsize = optget(opts, "StreamMaxLength")->numarg;
btread = sizeof(buff);
while((retval = poll_fd(acceptd, timeout, 0)) == 1) {
bread = recv(acceptd, buff, btread, 0);
if(bread <= 0)
break;
size += bread;
if(writen(tmpd, buff, bread) != bread) {
shutdown(sockfd, 2);
closesocket(sockfd);
closesocket(acceptd);
mdprintf(odesc, "Temporary file -> write ERROR\n");
logg("!ScanStream(%s@%u): Can't write to temporary file.\n", peer_addr, port);
close(tmpd);
if(!optget(opts, "LeaveTemporaryFiles")->enabled)
unlink(tmpname);
free(tmpname);
return -1;
}
if(maxsize && (size + btread >= maxsize)) {
btread = (maxsize - size); /* only read up to max */
if(btread <= 0) {
logg("^ScanStream(%s@%u): Size limit reached (max: %lu)\n", peer_addr, port, maxsize);
break; /* Scan what we have */
}
}
}
switch(retval) {
case 0: /* timeout */
mdprintf(odesc, "read timeout ERROR\n");
logg("!ScanStream(%s@%u): read timeout.\n", peer_addr, port);
break;
case -1:
mdprintf(odesc, "read poll ERROR\n");
logg("!ScanStream(%s@%u): read poll failed.\n", peer_addr, port);
break;
}
if(retval == 1) {
lseek(tmpd, 0, SEEK_SET);
thrmgr_setactivetask(peer_addr, NULL);
ret = cl_scandesc(tmpd, &virname, scanned, engine, options);
thrmgr_setactivetask(NULL, NULL);
} else {
ret = -1;
}
close(tmpd);
if(!optget(opts, "LeaveTemporaryFiles")->enabled)
unlink(tmpname);
free(tmpname);
closesocket(acceptd);
closesocket(sockfd);
if(ret == CL_VIRUS) {
mdprintf(odesc, "stream: %s FOUND\n", virname);
logg("stream(%s@%u): %s FOUND\n", peer_addr, port, virname);
virusaction("stream", virname, opts);
} else if(ret != CL_CLEAN) {
if(retval == 1) {
mdprintf(odesc, "stream: %s ERROR\n", cl_strerror(ret));
logg("stream(%s@%u): %s ERROR\n", peer_addr, port, cl_strerror(ret));
}
} else {
mdprintf(odesc, "stream: OK\n");
if(logok)
logg("stream(%s@%u): OK\n", peer_addr, port);
}
return ret;
}