/* * Copyright (C) 2002, 2003 Tomasz Kojm * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * 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., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include #include #include #include #include #include #include #include #ifdef CL_THREAD_SAFE # include pthread_mutex_t cli_scanrar_mutex = PTHREAD_MUTEX_INITIALIZER; int cli_scanrar_inuse = 0; //pthread_mutex_t cli_mbox_mutex = PTHREAD_MUTEX_INITIALIZER; //int cli_mbox_inuse = 0; #endif #include "clamav.h" #include "others.h" #include "matcher.h" #include "unrarlib.h" #ifdef HAVE_ZLIB_H #include #include #endif #ifdef HAVE_BZLIB_H #include #endif #define SCAN_ARCHIVE (options & CL_ARCHIVE) #define SCAN_MAIL (options & CL_MAIL) #define DISABLE_RAR (options & CL_DISABLERAR) #define MAGIC_BUFFER_SIZE 14 #define RAR_MAGIC_STR "Rar!" #define ZIP_MAGIC_STR "PK\003\004" #define GZIP_MAGIC_STR "\037\213" #define MAIL_MAGIC_STR "From " #define RAWMAIL_MAGIC_STR "Received: " #define MAILDIR_MAGIC_STR "Return-Path: " #define DELIVERED_MAGIC_STR "Delivered-To: " #define BZIP_MAGIC_STR "BZh" int cli_magic_scandesc(int desc, char **virname, long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options, int *reclev); int cli_scandesc(int desc, char **virname, long int *scanned, const struct cl_node *root) { char *buffer, *buff, *endbl, *pt; int bytes, buffsize, length; /* prepare the buffer */ buffsize = root->maxpatlen + SCANBUFF; if(!(buffer = (char *) cli_calloc(buffsize, sizeof(char)))) { cli_dbgmsg("cli_scandesc(): unable to malloc(%d)\n", buffsize); return CL_EMEM; } buff = buffer; buff += root->maxpatlen; /* pointer to read data block */ endbl = buff + SCANBUFF - root->maxpatlen; /* pointer to the last block * length of root->maxpatlen */ pt= buff; length = SCANBUFF; while((bytes = read(desc, buff, SCANBUFF)) > 0) { if(scanned != NULL) *scanned += bytes / CL_COUNT_PRECISION; if(bytes < SCANBUFF) length -= SCANBUFF - bytes; if(cl_scanbuff(pt, length, virname, root) == CL_VIRUS) { free(buffer); return CL_VIRUS; } if(bytes == SCANBUFF) memmove(buffer, endbl, root->maxpatlen); pt = buffer; length=buffsize; } free(buffer); return CL_CLEAN; } #ifdef CL_THREAD_SAFE void cli_unlock_mutex(void *mtx) { cli_dbgmsg("Pthread cancelled. Unlocking mutex.\n"); pthread_mutex_unlock(mtx); } #endif int cli_scanrar(int desc, char **virname, long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options, int *reclev) { FILE *tmp = NULL; int files = 0, fd, ret = CL_CLEAN; ArchiveList_struct *rarlist = NULL; char *rar_data_ptr; unsigned long rar_data_size; cli_dbgmsg("Starting scanrar()\n"); #ifdef CL_THREAD_SAFE pthread_cleanup_push(cli_unlock_mutex, &cli_scanrar_mutex); pthread_mutex_lock(&cli_scanrar_mutex); cli_scanrar_inuse = 1; #endif if(!urarlib_list(desc, (ArchiveList_struct *) &rarlist)) { #ifdef CL_THREAD_SAFE pthread_mutex_unlock(&cli_scanrar_mutex); cli_scanrar_inuse = 0; #endif return CL_ERAR; } while(rarlist) { if(limits) { if(limits->maxfilesize && (rarlist->item.UnpSize > limits->maxfilesize)) { cli_dbgmsg("RAR->%s: Size exceeded (%d, max: %d)\n", rarlist->item.Name, rarlist->item.UnpSize, limits->maxfilesize); rarlist = rarlist->next; files++; ret = CL_EMAXSIZE; continue; } if(limits->maxfiles && (files > limits->maxfiles)) { cli_dbgmsg("RAR: Files limit reached (max: %d)\n", limits->maxfiles); ret = CL_EMAXFILES; break; } } if((tmp = tmpfile()) == NULL) { cli_dbgmsg("RAR -> Can't generate tmpfile().\n"); #ifdef CL_THREAD_SAFE pthread_mutex_unlock(&cli_scanrar_mutex); cli_scanrar_inuse = 0; #endif return CL_ETMPFILE; } fd = fileno(tmp); if(urarlib_get(&rar_data_ptr, &rar_data_size, rarlist->item.Name, desc, "clam")) { cli_dbgmsg("RAR -> Extracted: %s, size: %d\n", rarlist->item.Name, rar_data_size); if(fwrite(rar_data_ptr, rar_data_size, 1, tmp) != 1) { cli_dbgmsg("RAR -> Can't write() file.\n"); fclose(tmp); tmp = NULL; ret = CL_ERAR; if(rar_data_ptr) { free(rar_data_ptr); rar_data_ptr = NULL; } break; } if(rar_data_ptr) { free(rar_data_ptr); rar_data_ptr = NULL; } if(fflush(tmp) != 0) { cli_dbgmsg("fflush() failed: %s\n", strerror(errno)); fclose(tmp); urarlib_freelist(rarlist); #ifdef CL_THREAD_SAFE pthread_mutex_unlock(&cli_scanrar_mutex); cli_scanrar_inuse = 0; #endif return CL_EFSYNC; } lseek(fd, 0, SEEK_SET); if((ret = cli_magic_scandesc(fd, virname, scanned, root, limits, options, reclev)) == CL_VIRUS ) { cli_dbgmsg("RAR -> Found %s virus.\n", *virname); fclose(tmp); urarlib_freelist(rarlist); #ifdef CL_THREAD_SAFE pthread_mutex_unlock(&cli_scanrar_mutex); cli_scanrar_inuse = 0; #endif return CL_VIRUS; } } else { cli_dbgmsg("RAR -> Can't decompress file %s\n", rarlist->item.Name); fclose(tmp); ret = CL_ERAR; /* WinRAR 3.0 ? */ break; } fclose(tmp); tmp = NULL; rarlist = rarlist->next; files++; } urarlib_freelist(rarlist); #ifdef CL_THREAD_SAFE pthread_mutex_unlock(&cli_scanrar_mutex); cli_scanrar_inuse = 0; pthread_cleanup_pop(0); #endif return ret; } #ifdef HAVE_ZLIB_H int cli_scanzip(int desc, char **virname, long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options, int *reclev) { ZZIP_DIR *zdir; ZZIP_DIRENT zdirent; ZZIP_FILE *zfp; FILE *tmp = NULL; char *buff; int fd, bytes, files = 0, ret = CL_CLEAN, err; struct stat source; cli_dbgmsg("Starting scanzip()\n"); if((zdir = zzip_dir_fdopen(dup(desc), &err)) == NULL) { cli_dbgmsg("Zip -> Not supported file format ?.\n"); cli_dbgmsg("zzip_dir_fdopen() return code: %d\n", err); return CL_EZIP; } fstat(desc, &source); if(!(buff = (char *) cli_malloc(FILEBUFF))) { cli_dbgmsg("cli_scanzip(): unable to malloc(%d)\n", FILEBUFF); zzip_dir_close(zdir); return CL_EMEM; } while(zzip_dir_read(zdir, &zdirent)) { if(!zdirent.d_name || !strlen(zdirent.d_name)) { /* Mimail fix */ cli_dbgmsg("strlen(zdirent.d_name) == %d\n", strlen(zdirent.d_name)); *virname = "Suspected.Zip"; ret = CL_VIRUS; break; } cli_dbgmsg("Zip -> %s, compressed: %d, normal: %d.\n", zdirent.d_name, zdirent.d_csize, zdirent.st_size); if(limits && limits->maxratio > 0 && source.st_size && (zdirent.st_size / source.st_size) >= limits->maxratio) { *virname = "Oversized.Zip"; ret = CL_VIRUS; break; } if(!zdirent.st_size) { /* omit directories and null files */ files++; continue; } /* work-around for problematic zips (zziplib crashes with them) */ if(zdirent.d_csize < 0 || zdirent.st_size < 0) { files++; cli_dbgmsg("Zip -> Malformed archive detected.\n"); /* ret = CL_EMALFZIP; */ /* report it as a virus */ *virname = "Suspected.Zip"; ret = CL_VIRUS; break; } if(limits) { if(limits->maxfilesize && (zdirent.st_size > limits->maxfilesize)) { cli_dbgmsg("Zip -> %s: Size exceeded (%d, max: %d)\n", zdirent.d_name, zdirent.st_size, limits->maxfilesize); files++; ret = CL_EMAXSIZE; continue; /* this is not a bug */ } if(limits->maxfiles && (files > limits->maxfiles)) { cli_dbgmsg("Zip: Files limit reached (max: %d)\n", limits->maxfiles); ret = CL_EMAXFILES; break; } } /* generate temporary file and get its descriptor */ if((tmp = tmpfile()) == NULL) { cli_dbgmsg("Zip -> Can't generate tmpfile().\n"); ret = CL_ETMPFILE; break; } if((zfp = zzip_file_open(zdir, zdirent.d_name, 0)) == NULL) { cli_dbgmsg("Zip -> %s: Can't open file.\n", zdirent.d_name); ret = CL_EZIP; break; } while((bytes = zzip_file_read(zfp, buff, FILEBUFF)) > 0) { if(fwrite(buff, bytes, 1, tmp)*bytes != bytes) { cli_dbgmsg("Zip -> Can't fwrite() file: %s\n", strerror(errno)); zzip_file_close(zfp); zzip_dir_close(zdir); fclose(tmp); free(buff); return CL_EZIP; } } zzip_file_close(zfp); if(fflush(tmp) != 0) { cli_errmsg("fflush() failed: %s\n", strerror(errno)); ret = CL_EFSYNC; break; } fd = fileno(tmp); lseek(fd, 0, SEEK_SET); if((ret = cli_magic_scandesc(fd, virname, scanned, root, limits, options, reclev)) == CL_VIRUS ) { cli_dbgmsg("Zip -> Found %s virus.\n", *virname); ret = CL_VIRUS; break; } else if(ret == CL_EMALFZIP) { /* * The trick with detection of ZoD only works with higher (>= 5) * recursion limit level. */ cli_dbgmsg("Zip -> Malformed Zip, scanning stopped.\n"); *virname = "Suspected.Zip"; ret = CL_VIRUS; break; } if (tmp) { fclose(tmp); tmp = NULL; } files++; } zzip_dir_close(zdir); if (tmp) { fclose(tmp); tmp = NULL; } free(buff); return ret; } int cli_scangzip(int desc, char **virname, long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options, int *reclev) { int fd, bytes, ret = CL_CLEAN; long int size = 0; char *buff; FILE *tmp = NULL; gzFile gd; cli_dbgmsg("in cli_scangzip()\n"); if((gd = gzdopen(dup(desc), "rb")) == NULL) { cli_dbgmsg("Can't gzdopen() descriptor %d.\n", desc); return CL_EGZIP; } if((tmp = tmpfile()) == NULL) { cli_dbgmsg("Can't generate tmpfile().\n"); gzclose(gd); return CL_ETMPFILE; } fd = fileno(tmp); if(!(buff = (char *) cli_malloc(FILEBUFF))) { cli_dbgmsg("cli_scangzip(): unable to malloc(%d)\n", FILEBUFF); gzclose(gd); return CL_EMEM; } while((bytes = gzread(gd, buff, FILEBUFF)) > 0) { size += bytes; if(limits) if(limits->maxfilesize && (size + FILEBUFF > limits->maxfilesize)) { cli_dbgmsg("Gzip->desc(%d): Size exceeded (stopped at %d, max: %d)\n", desc, size, limits->maxfilesize); ret = CL_EMAXSIZE; break; } if(write(fd, buff, bytes) != bytes) { cli_dbgmsg("Gzip -> Can't write() file.\n"); fclose(tmp); gzclose(gd); free(buff); return CL_EGZIP; } } free(buff); gzclose(gd); if(fsync(fd) == -1) { cli_dbgmsg("fsync() failed for descriptor %d\n", fd); fclose(tmp); return CL_EFSYNC; } lseek(fd, 0, SEEK_SET); if((ret = cli_magic_scandesc(fd, virname, scanned, root, limits, options, reclev)) == CL_VIRUS ) { cli_dbgmsg("Gzip -> Found %s virus.\n", *virname); fclose(tmp); return CL_VIRUS; } fclose(tmp); return ret; } #endif #ifdef HAVE_BZLIB_H #ifdef NOBZ2PREFIX #define BZ2_bzReadOpen bzReadOpen #define BZ2_bzReadClose bzReadClose #define BZ2_bzRead bzRead #endif int cli_scanbzip(int desc, char **virname, long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options, int *reclev) { int fd, bytes, ret = CL_CLEAN, bzerror = 0; short memlim = 0; long int size = 0; char *buff; FILE *fs, *tmp = NULL; BZFILE *bfd; if((fs = fdopen(dup(desc), "rb")) == NULL) { cli_errmsg("Can't fdopen() descriptor %d.\n", desc); return CL_EBZIP; } if(limits) if(limits->archivememlim) memlim = 1; if((bfd = BZ2_bzReadOpen(&bzerror, fs, memlim, 0, NULL, 0)) == NULL) { cli_dbgmsg("Can't initialize bzip2 library (descriptor %d).\n", desc); fclose(fs); return CL_EBZIP; } if((tmp = tmpfile()) == NULL) { cli_dbgmsg("Can't generate tmpfile().\n"); BZ2_bzReadClose(&bzerror, bfd); fclose(fs); return CL_ETMPFILE; } fd = fileno(tmp); if(!(buff = (char *) malloc(FILEBUFF))) { cli_dbgmsg("cli_scanbzip(): unable to malloc(%d)\n", FILEBUFF); fclose(tmp); fclose(fs); BZ2_bzReadClose(&bzerror, bfd); return CL_EMEM; } while((bytes = BZ2_bzRead(&bzerror, bfd, buff, FILEBUFF)) > 0) { size += bytes; if(limits) if(limits->maxfilesize && (size + FILEBUFF > limits->maxfilesize)) { cli_dbgmsg("Bzip2->desc(%d): Size exceeded (stopped at %d, max: %d)\n", desc, size, limits->maxfilesize); ret = CL_EMAXSIZE; break; } if(write(fd, buff, bytes) != bytes) { cli_dbgmsg("Bzip2 -> Can't write() file.\n"); BZ2_bzReadClose(&bzerror, bfd); fclose(tmp); free(buff); fclose(fs); return CL_EGZIP; } } free(buff); BZ2_bzReadClose(&bzerror, bfd); if(fsync(fd) == -1) { cli_dbgmsg("fsync() failed for descriptor %d\n", fd); fclose(tmp); fclose(fs); return CL_EFSYNC; } lseek(fd, 0, SEEK_SET); if((ret = cli_magic_scandesc(fd, virname, scanned, root, limits, options, reclev)) == CL_VIRUS ) { cli_dbgmsg("Bzip2 -> Found %s virus.\n", *virname); } fclose(tmp); fclose(fs); return ret; } #endif int cli_scandir(char *dirname, char **virname, long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options, int *reclev) { DIR *dd; struct dirent *dent; struct stat statbuf; char *fname; if((dd = opendir(dirname)) != NULL) { while((dent = readdir(dd))) { if(dent->d_ino) { if(strcmp(dent->d_name, ".") && strcmp(dent->d_name, "..")) { /* build the full name */ fname = cli_calloc(strlen(dirname) + strlen(dent->d_name) + 2, sizeof(char)); 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)) cli_scandir(dirname, virname, scanned, root, limits, options, reclev); else if(S_ISREG(statbuf.st_mode)) if(cl_scanfile(fname, virname, scanned, root, limits, options) == CL_VIRUS) { free(fname); closedir(dd); return CL_VIRUS; } } free(fname); } } } } else { cli_errmsg("ScanDir -> Can't open directory %s.\n", dirname); return CL_EOPEN; } closedir(dd); return 0; } int cli_scanmail(int desc, char **virname, long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options, int *reclev) { const char *tmpdir; char *dir; int ret; cli_dbgmsg("Starting scanmail()\n"); /* #ifdef CL_THREAD_SAFE pthread_cleanup_push(cli_unlock_mutex, &cli_mbox_mutex); pthread_mutex_lock(&cli_mbox_mutex); cli_mbox_inuse = 1; #endif */ tmpdir = getenv("TMPDIR"); if(tmpdir == NULL) #ifdef P_tmpdir tmpdir = P_tmpdir; #else tmpdir = "/tmp"; #endif /* generate the temporary directory */ dir = cl_gentemp(tmpdir); if(mkdir(dir, 0700)) { cli_errmsg("ScanMail -> Can't create temporary directory %s\n", dir); /* #ifdef CL_THREAD_SAFE pthread_mutex_unlock(&cli_mbox_mutex); cli_mbox_inuse = 0; #endif */ return CL_ETMPDIR; } /* * Extract the attachments into the temporary directory */ ret = cl_mbox(dir, desc); /* FIXME: check mbox return code */ ret = cli_scandir(dir, virname, scanned, root, limits, options, reclev); cli_rmdirs(dir); free(dir); /* #ifdef CL_THREAD_SAFE pthread_mutex_unlock(&cli_mbox_mutex); cli_mbox_inuse = 0; pthread_cleanup_pop(0); #endif */ return ret; } int cli_magic_scandesc(int desc, char **virname, long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options, int *reclev) { char magic[MAGIC_BUFFER_SIZE+1]; int ret = CL_CLEAN; int bread = 0; if(!root) { cli_errmsg("root == NULL\n"); return -1; } if(SCAN_ARCHIVE || SCAN_MAIL) { /* Need to examine file type */ if(SCAN_ARCHIVE && limits && limits->maxreclevel) if(*reclev > limits->maxreclevel) return CL_EMAXREC; (*reclev)++; lseek(desc, 0, SEEK_SET); bread = read(desc, magic, MAGIC_BUFFER_SIZE); magic[MAGIC_BUFFER_SIZE] = '\0'; /* terminate magic string properly */ lseek(desc, 0, SEEK_SET); if (bread != MAGIC_BUFFER_SIZE) { /* short read: No need to do magic */ (*reclev)--; return ret; } #ifdef CL_THREAD_SAFE /* this check protects against recursive deadlock */ if(!DISABLE_RAR && SCAN_ARCHIVE && !cli_scanrar_inuse && !strncmp(magic, RAR_MAGIC_STR, strlen(RAR_MAGIC_STR))) { cli_dbgmsg("Recognized rar file.\n"); ret = cli_scanrar(desc, virname, scanned, root, limits, options, reclev); } #else if(!DISABLE_RAR && SCAN_ARCHIVE && !strncmp(magic, RAR_MAGIC_STR, strlen(RAR_MAGIC_STR))) { cli_dbgmsg("Recognized rar file.\n"); ret = cli_scanrar(desc, virname, scanned, root, limits, options, reclev); } #endif #ifdef HAVE_ZLIB_H else if(SCAN_ARCHIVE && !strncmp(magic, ZIP_MAGIC_STR, strlen(ZIP_MAGIC_STR))) { cli_dbgmsg("Recognized zip file.\n"); ret = cli_scanzip(desc, virname, scanned, root, limits, options, reclev); } else if(SCAN_ARCHIVE && !strncmp(magic, GZIP_MAGIC_STR, strlen(GZIP_MAGIC_STR))) { cli_dbgmsg("Recognized gzip file.\n"); ret = cli_scangzip(desc, virname, scanned, root, limits, options, reclev); } #endif #ifdef HAVE_BZLIB_H else if(SCAN_ARCHIVE && !strncmp(magic, BZIP_MAGIC_STR, strlen(BZIP_MAGIC_STR))) { cli_dbgmsg("Recognized bzip file.\n"); ret = cli_scanbzip(desc, virname, scanned, root, limits, options, reclev); } #endif else if(SCAN_MAIL && !strncmp(magic, MAIL_MAGIC_STR, strlen(MAIL_MAGIC_STR))) { cli_dbgmsg("Recognized mail file.\n"); ret = cli_scanmail(desc, virname, scanned, root, limits, options, reclev); } else if(SCAN_MAIL && !strncmp(magic, RAWMAIL_MAGIC_STR, strlen(RAWMAIL_MAGIC_STR))) { cli_dbgmsg("Recognized raw mail file.\n"); ret = cli_scanmail(desc, virname, scanned, root, limits, options, reclev); } else if(SCAN_MAIL && !strncmp(magic, MAILDIR_MAGIC_STR, strlen(MAILDIR_MAGIC_STR))) { cli_dbgmsg("Recognized Maildir mail file.\n"); ret = cli_scanmail(desc, virname, scanned, root, limits, options, reclev); } else if(SCAN_MAIL && !strncmp(magic, DELIVERED_MAGIC_STR, strlen(DELIVERED_MAGIC_STR))) { cli_dbgmsg("Recognized (Delivered-To) mail file.\n"); ret = cli_scanmail(desc, virname, scanned, root, limits, options, reclev); } (*reclev)--; } if(ret != CL_VIRUS) /* scan the raw file */ lseek(desc, 0, SEEK_SET); /* If archive scan didn't rewind desc */ if(cli_scandesc(desc, virname, scanned, root) == CL_VIRUS) { cli_dbgmsg("%s virus found in descriptor %d.\n", *virname, desc); return CL_VIRUS; } return ret; } int cl_scandesc(int desc, char **virname, unsigned long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options) { int reclev = 0; return cli_magic_scandesc(desc, virname, scanned, root, limits, options, &reclev); } int cl_scanfile(const char *filename, char **virname, unsigned long int *scanned, const struct cl_node *root, const struct cl_limits *limits, int options) { int fd, ret; if((fd = open(filename, O_RDONLY)) == -1) return CL_EOPEN; cli_dbgmsg("Scanning %s\n", filename); ret = cl_scandesc(fd, virname, scanned, root, limits, options); close(fd); return ret; }