吃饱饭继续浏览Manager.c的scanmanager函数，这个函数的功能吧，暂时理解如下。
接收一个命令行参数（经过处理的optstruct结构指针）。
然后根据选项判断文件类型种类，还有一些扫描选项。看到了AC-Only选项，可是没有BM-Only选项，不解。然后就进行了病毒库的加载和引擎的初始化，接着进行了一些扫描限制（扫描文件大小、数量、递归深度等）设定，还有扫描的文件类型（貌似上面的是用来构建引擎，现在的是用来设置扫描）。然后就是重点，针对文件名进行处理，判断是否是目录还是单个文件，调用不同的扫描函数。
代码注释如下：（应该不是完全正确的）
int scanmanager(const struct optstruct *opt)
{
mode_t fmode;
int ret = 0, extunpacker = 0, fmodeint, i, x;
unsigned int options = 0, dboptions = 0;
struct cl_engine *engine = NULL;
struct cl_limits limits;
struct passwd *user = NULL;
struct stat sb;
char *fullpath = NULL, cwd[1024]; //扫描文件类型判断
if(opt_check(opt, "unzip") || opt_check(opt, "unrar") || opt_check(opt, "arj") ||
opt_check(opt, "unzoo") || opt_check(opt, "jar") || opt_check(opt, "lha") ||
opt_check(opt, "tar") || opt_check(opt, "tgz") || opt_check(opt, "deb"))
extunpacker = 1; //获取CLAMAVUSER的用户信息，识别码和根目录
//参考passwd结构
/* njh@bandsman.co.uk: BeOS */
#if !defined(C_CYGWIN) && !defined(C_OS2) && !defined(C_BEOS) && !defined(C_WINDOWS)
if(extunpacker && !geteuid()) {
if((user = getpwnam(CLAMAVUSER)) == NULL) {
logg("!Can't get information about user "CLAMAVUSER" (required to run external unpackers)\n");
exit(60); /* this is critical problem, so we just exit here */
}
}
#endif //添加扫描选项
if(!opt_check(opt, "no-phishing-sigs"))
dboptions |= CL_DB_PHISHING; if(!opt_check(opt,"no-phishing-scan-urls"))
dboptions |= CL_DB_PHISHING_URLS;
if(opt_check(opt,"phishing-ssl")) {
options |= CL_SCAN_PHISHING_BLOCKSSL;
}
if(opt_check(opt,"phishing-cloak")) {
options |= CL_SCAN_PHISHING_BLOCKCLOAK;
} if(opt_check(opt, "dev-ac-only"))
dboptions |= CL_DB_ACONLY; //这个选项需要学习下，深度搜查用AC?
if(opt_check(opt, "dev-ac-depth"))
cli_ac_setdepth(AC_DEFAULT_MIN_DEPTH, atoi(opt_arg(opt, "dev-ac-depth"))); if(opt_check(opt, "detect-pua"))
dboptions |= CL_DB_PUA; //传说中的病毒库加载
if(opt_check(opt, "database")) {
if((ret = cl_load(opt_arg(opt, "database"), &engine, &info.sigs, dboptions))) {
logg("!%s\n", cl_strerror(ret));
return 50;
} } else {
char *dbdir = freshdbdir(); //病毒库更新后重新加载
if((ret = cl_load(dbdir, &engine, &info.sigs, dboptions))) {
logg("!%s\n", cl_strerror(ret));
free(dbdir);
return 50;
}
free(dbdir);
} if(!engine) {
logg("!Can't initialize the virus database\n");
return 50;
} //引擎构建
if((ret = cl_build(engine)) != 0) {
logg("!Database initialization error: %s\n", cl_strerror(ret));;
return 50;
} /* set limits */
//开始设置限制，应该是扫描大小等
memset(&limits, 0, sizeof(struct cl_limits)); //最大的扫描大小
if(opt_check(opt, "max-scansize")) {
char *cpy, *ptr;
ptr = opt_arg(opt, "max-scansize");
if(tolower(ptr[strlen(ptr) - 1]) == 'm') {
cpy = calloc(strlen(ptr), 1);
strncpy(cpy, ptr, strlen(ptr) - 1);
cpy[strlen(ptr)-1]='\0';
limits.maxscansize = atoi(cpy) * 1024 * 1024;
free(cpy);
} else
limits.maxscansize = atoi(ptr) * 1024;
} else
limits.maxscansize = 104857600; //最大文件大小
if(opt_check(opt, "max-filesize")) {
char *cpy, *ptr;
ptr = opt_arg(opt, "max-filesize");
if(tolower(ptr[strlen(ptr) - 1]) == 'm') {
cpy = calloc(strlen(ptr), 1);
strncpy(cpy, ptr, strlen(ptr) - 1);
cpy[strlen(ptr)-1]='\0';
limits.maxfilesize = atoi(cpy) * 1024 * 1024;
free(cpy);
} else
limits.maxfilesize = atoi(ptr) * 1024;
} else
limits.maxfilesize = 26214400; //最大文件数
if(opt_check(opt, "max-files"))
limits.maxfiles = atoi(opt_arg(opt, "max-files"));
else
limits.maxfiles = 10000; //最大递归深度
if(opt_check(opt, "max-recursion"))
limits.maxreclevel = atoi(opt_arg(opt, "max-recursion"));
else
limits.maxreclevel = 16; /* set options */
//设置选项，扫描文件类型相关
if(opt_check(opt, "disable-archive") || opt_check(opt, "no-archive"))
options &= ~CL_SCAN_ARCHIVE;
else
options |= CL_SCAN_ARCHIVE; if(opt_check(opt, "detect-broken"))
options |= CL_SCAN_BLOCKBROKEN; if(opt_check(opt, "block-encrypted"))
options |= CL_SCAN_BLOCKENCRYPTED; if(opt_check(opt, "no-pe"))
options &= ~CL_SCAN_PE;
else
options |= CL_SCAN_PE; if(opt_check(opt, "no-elf"))
options &= ~CL_SCAN_ELF;
else
options |= CL_SCAN_ELF; if(opt_check(opt, "no-ole2"))
options &= ~CL_SCAN_OLE2;
else
options |= CL_SCAN_OLE2; if(opt_check(opt, "no-pdf"))
options &= ~CL_SCAN_PDF;
else
options |= CL_SCAN_PDF; if(opt_check(opt, "no-html"))
options &= ~CL_SCAN_HTML;
else
options |= CL_SCAN_HTML; if(opt_check(opt, "no-mail")) {
options &= ~CL_SCAN_MAIL;
} else {
options |= CL_SCAN_MAIL; if(opt_check(opt, "mail-follow-urls"))
options |= CL_SCAN_MAILURL;
} if(opt_check(opt, "no-algorithmic"))
options &= ~CL_SCAN_ALGORITHMIC;
else
options |= CL_SCAN_ALGORITHMIC; //Linux下，需要获取设备号
//具体参见文件属性stat结构
#ifdef C_LINUX
procdev = (dev_t) 0;
if(stat("/proc", &sb) != -1 && !sb.st_size)
procdev = sb.st_dev;
#endif /* check filetype */
//遇到扫描目录的情况
if(opt->filename == NULL || strlen(opt->filename) == 0) { /* we need full path for some reasons (eg. archive handling) */
//获取当前工作目录
//获取到后调用目录扫描函数scandirs
if(!getcwd(cwd, sizeof(cwd))) {
logg("!Can't get absolute pathname of current working directory\n");
ret = 57;
} else
ret = scandirs(cwd, engine, user, opt, &limits, options); } else if(!strcmp(opt->filename, "-")) { /* read data from stdin */
ret = scanstdin(engine, &limits, options); } else {
//扫描文件的情况
char *thefilename;
for (x = 0; (thefilename = cli_strtok(opt->filename, x, "\t")) != NULL; x++) {
//fileinfo函数在clamscan的others.c里定义
//2代表获取文件权限
//有访问权限后找出最右边/的个数
if((fmodeint = fileinfo(thefilename, 2)) == -1) {
logg("^Can't access file %s\n", thefilename);
perror(thefilename);
ret = 56;
} else {
int slash = 1;
for(i = strlen(thefilename) - 1; i > 0 && slash; i--) {
if(thefilename[i] == '/')
thefilename[i] = 0;
else
slash = 0;
} fmode = (mode_t) fmodeint; //下面依旧是处理文件名的
if(extunpacker && (thefilename[0] != '/' && thefilename[0] != '\\' && thefilename[1] != ':')) {
/* we need to complete the path */
if(!getcwd(cwd, sizeof(cwd))) {
logg("!Can't get absolute pathname of current working directory\n");
return 57;
} else {
fullpath = malloc(512);
#ifdef NO_SNPRINTF
sprintf(fullpath, "%s/%s", cwd, thefilename);
#else
snprintf(fullpath, 512, "%s/%s", cwd, thefilename);
#endif
logg("*Full path: %s\n", fullpath);
}
} else
fullpath = thefilename; //开始区别扫描文件和文件夹
switch(fmode & S_IFMT) {
case S_IFREG:
ret = scanfile(fullpath, engine, user, opt, &limits, options);
break; case S_IFDIR:
ret = scandirs(fullpath, engine, user, opt, &limits, options);
break; default:
logg("!Not supported file type (%s)\n", thefilename);
ret = 52;
} if(extunpacker && (thefilename[0] != '/' && thefilename[0] != '\\' && thefilename[1] != ':')) {
free(fullpath);
fullpath = NULL;
}
}
free(thefilename);
}
} /* free the engine */
cl_free(engine); /* overwrite return code */
if(info.ifiles)
ret = 1;
else if(ret < 50) /* hopefully no error detected */
ret = 0; /* just make sure it's 0 */ return ret;
}