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253 lines
9.2 KiB
253 lines
9.2 KiB
/*
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* Copyright (C) 2002 - 2005 Tomasz Kojm <tkojm@clamav.net>
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* With enhancements from Thomas Lamy <Thomas.Lamy@in-online.net>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#if HAVE_CONFIG_H
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#include "clamav-config.h"
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#endif
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#include <stdio.h>
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#include <string.h>
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#include <stdlib.h>
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#include <ctype.h>
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#include "clamav.h"
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#include "filetypes.h"
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#include "others.h"
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#include "readdb.h"
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struct cli_magic_s {
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int offset;
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const char *magic;
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size_t length;
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const char *descr;
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cli_file_t type;
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};
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struct cli_smagic_s {
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const char *sig;
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const char *descr;
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cli_file_t type;
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};
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static const struct cli_magic_s cli_magic[] = {
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/* Executables */
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{0, "MZ", 2, "DOS/W32 executable/library/driver", CL_TYPE_MSEXE},
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/* Archives */
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{0, "Rar!", 4, "RAR", CL_TYPE_RAR},
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{0, "PK\003\004", 4, "ZIP", CL_TYPE_ZIP},
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{0, "PK00PK\003\004", 8, "ZIP", CL_TYPE_ZIP},
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{0, "\037\213", 2, "GZip", CL_TYPE_GZ},
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{0, "BZh", 3, "BZip", CL_TYPE_BZ},
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{0, "SZDD", 4, "compress.exe'd", CL_TYPE_MSSZDD},
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{0, "MSCF", 4, "MS CAB", CL_TYPE_MSCAB},
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{0, "ITSF", 4, "MS CHM", CL_TYPE_MSCHM},
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{0, "#@~^", 4, "SCRENC", CL_TYPE_SCRENC},
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{0, "(This file must be converted with BinHex 4.0)",
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45, "BinHex", CL_TYPE_BINHEX},
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/* Mail */
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{0, "From ", 5, "MBox", CL_TYPE_MAIL},
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{0, "Received: ", 10, "Raw mail", CL_TYPE_MAIL},
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{0, "Return-Path: ", 13, "Maildir", CL_TYPE_MAIL},
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{0, "Return-path: ", 13, "Maildir", CL_TYPE_MAIL},
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{0, "Delivered-To: ", 14, "Mail", CL_TYPE_MAIL},
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{0, "X-UIDL: ", 8, "Mail", CL_TYPE_MAIL},
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{0, "X-Apparently-To: ", 17, "Mail", CL_TYPE_MAIL},
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{0, "X-Envelope-From: ", 17, "Mail", CL_TYPE_MAIL},
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{0, "X-Original-To: ", 15, "Mail", CL_TYPE_MAIL},
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{0, "X-Symantec-", 11, "Symantec", CL_TYPE_MAIL},
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{0, "X-EVS", 5, "EVS mail", CL_TYPE_MAIL},
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{0, "X-Real-To: ", 11, "Mail", CL_TYPE_MAIL},
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{0, "X-Sieve: ", 9, "Mail", CL_TYPE_MAIL},
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{0, ">From ", 6, "Mail", CL_TYPE_MAIL},
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{0, "Date: ", 6, "Mail", CL_TYPE_MAIL},
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{0, "Message-Id: ", 12, "Mail", CL_TYPE_MAIL},
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{0, "Message-ID: ", 12, "Mail", CL_TYPE_MAIL},
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{0, "Envelope-to: ", 13, "Mail", CL_TYPE_MAIL},
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{0, "Delivery-date: ", 15, "Mail", CL_TYPE_MAIL},
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{0, "To: ", 4, "Mail", CL_TYPE_MAIL},
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{0, "Subject: ", 9, "Mail", CL_TYPE_MAIL},
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{0, "For: ", 5, "Eserv mail", CL_TYPE_MAIL},
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{0, "From: ", 6, "Exim mail", CL_TYPE_MAIL},
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{0, "v:\015\012Received: ", 14, "VPOP3 Mail (DOS)", CL_TYPE_MAIL},
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{0, "v:\012Received: ", 13, "VPOP3 Mail (UNIX)", CL_TYPE_MAIL},
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{0, "Hi. This is the qmail-send", 26, "Qmail bounce", CL_TYPE_MAIL},
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/* Others */
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{0, "\320\317\021\340\241\261\032\341",
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8, "OLE2 container", CL_TYPE_MSOLE2},
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/* Graphics (may contain exploits against MS systems) */
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{0, "GIF", 3, "GIF", CL_TYPE_GRAPHICS},
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{0, "BM", 2, "BMP", CL_TYPE_GRAPHICS},
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{0, "\377\330\377", 3, "JPEG", CL_TYPE_GRAPHICS},
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{6, "JFIF", 4, "JPEG", CL_TYPE_GRAPHICS},
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{6, "Exif", 4, "JPEG", CL_TYPE_GRAPHICS},
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{0, "\x89PNG", 4, "PNG", CL_TYPE_GRAPHICS},
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{0, "RIFF", 4, "RIFF", CL_TYPE_RIFF},
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{0, "RIFX", 4, "RIFX", CL_TYPE_RIFF},
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/* Ignored types */
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{0, "\000\000\001\263", 4, "MPEG video stream", CL_TYPE_DATA},
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{0, "\000\000\001\272", 4, "MPEG sys stream", CL_TYPE_DATA},
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{0, "OggS", 4, "Ogg Stream", CL_TYPE_DATA},
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{0, "ID3", 3, "MP3", CL_TYPE_DATA},
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{0, "\377\373\220", 3, "MP3", CL_TYPE_DATA},
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{0, "\%PDF-", 5, "PDF document", CL_TYPE_DATA},
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{0, "\%!PS-Adobe-", 11, "PostScript", CL_TYPE_DATA},
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{0, "\060\046\262\165\216\146\317", 7, "WMA/WMV/ASF", CL_TYPE_DATA},
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{0, ".RMF" , 4, "Real Media File", CL_TYPE_DATA},
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{-1, NULL, 0, NULL, CL_TYPE_UNKNOWN_DATA}
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};
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static const struct cli_smagic_s cli_smagic[] = {
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/* "\nFrom: " * "\nContent-Type: " */
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{"0a46726f6d3a20{-2048}0a436f6e74656e742d547970653a20", "Mail file", CL_TYPE_MAIL},
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/* "\nReceived: " * "\nContent-Type: " */
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{"0a52656365697665643a20{-2048}0a436f6e74656e742d547970653a20", "Mail file", CL_TYPE_MAIL},
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/* "\nReceived: " * "\nContent-type: " */
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{"0a52656365697665643a20{-2048}0a436f6e74656e742d747970653a20", "Mail file", CL_TYPE_MAIL},
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/* "MIME-Version: " * "\nContent-Type: " */
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{"4d494d452d56657273696f6e3a20{-2048}0a436f6e74656e742d547970653a20", "Mail file", CL_TYPE_MAIL},
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/* remember the matcher is case sensitive */
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{"3c62723e", "HTML data", CL_TYPE_HTML}, /* <br> */
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{"3c42723e", "HTML data", CL_TYPE_HTML}, /* <Br> */
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{"3c42523e", "HTML data", CL_TYPE_HTML}, /* <BR> */
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{"3c703e", "HTML data", CL_TYPE_HTML}, /* <p> */
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{"3c503e", "HTML data", CL_TYPE_HTML}, /* <P> */
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{"68726566", "HTML data", CL_TYPE_HTML}, /* href */
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{"48726566", "HTML data", CL_TYPE_HTML}, /* Href */
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{"48524546", "HTML data", CL_TYPE_HTML}, /* HREF */
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{"3c68746d6c3e", "HTML data", CL_TYPE_HTML}, /* <html> */
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{"3c48544d4c3e", "HTML data", CL_TYPE_HTML}, /* <HTML> */
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{"3c48746d6c3e", "HTML data", CL_TYPE_HTML}, /* <Html> */
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{"3c686561643e", "HTML data", CL_TYPE_HTML}, /* <head> */
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{"3c484541443e", "HTML data", CL_TYPE_HTML}, /* <HEAD> */
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{"3c486561643e", "HTML data", CL_TYPE_HTML}, /* <Head> */
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{"3c666f6e74", "HTML data", CL_TYPE_HTML}, /* <font */
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{"3c466f6e74", "HTML data", CL_TYPE_HTML}, /* <Font */
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{"3c464f4e54", "HTML data", CL_TYPE_HTML}, /* <FONT */
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{"3c696d67", "HTML data", CL_TYPE_HTML}, /* <img */
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{"3c494d47", "HTML data", CL_TYPE_HTML}, /* <IMG */
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{"3c496d67", "HTML data", CL_TYPE_HTML}, /* <Img */
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{"3c736372697074", "HTML data", CL_TYPE_HTML}, /* <script */
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{"3c536372697074", "HTML data", CL_TYPE_HTML}, /* <Script */
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{"3c534352495054", "HTML data", CL_TYPE_HTML}, /* <SCRIPT */
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{"3c6f626a656374", "HTML data", CL_TYPE_HTML}, /* <object */
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{"3c4f626a656374", "HTML data", CL_TYPE_HTML}, /* <Object */
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{"3c4f424a454354", "HTML data", CL_TYPE_HTML}, /* <OBJECT */
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{"3c696672616d65", "HTML data", CL_TYPE_HTML}, /* <iframe */
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{"3c494652414d45", "HTML data", CL_TYPE_HTML}, /* <IFRAME */
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{NULL, NULL, CL_TYPE_UNKNOWN_DATA}
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};
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cli_file_t cli_filetype(const char *buf, size_t buflen)
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{
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int i, ascii = 1, len;
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for(i = 0; cli_magic[i].magic; i++) {
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if(buflen >= cli_magic[i].offset+cli_magic[i].length) {
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if(memcmp(buf+cli_magic[i].offset, cli_magic[i].magic, cli_magic[i].length) == 0) {
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cli_dbgmsg("Recognized %s file\n", cli_magic[i].descr);
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return cli_magic[i].type;
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}
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}
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}
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buflen < 25 ? (len = buflen) : (len = 25);
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for(i = 0; i < len; i++)
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if(!iscntrl(buf[i]) && !isprint(buf[i])) { /* FIXME: handle international chars */
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ascii = 0;
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break;
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}
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return ascii ? CL_TYPE_UNKNOWN_TEXT : CL_TYPE_UNKNOWN_DATA;
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}
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int is_tar(unsigned char *buf, int nbytes);
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cli_file_t cli_filetype2(int desc)
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{
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char smallbuff[MAGIC_BUFFER_SIZE + 1];
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unsigned char *bigbuff;
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int bread;
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cli_file_t ret = CL_TYPE_UNKNOWN_DATA;
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memset(smallbuff, 0, sizeof(smallbuff));
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if((bread = read(desc, smallbuff, MAGIC_BUFFER_SIZE)) > 0)
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ret = cli_filetype(smallbuff, bread);
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if(ret == CL_TYPE_UNKNOWN_DATA || ret == CL_TYPE_UNKNOWN_TEXT) {
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if(!(bigbuff = (unsigned char *) cli_calloc(16384 + 1, sizeof(unsigned char))))
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return ret;
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lseek(desc, 0, SEEK_SET);
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if((bread = read(desc, bigbuff, 16384)) > 0) {
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bigbuff[bread] = 0;
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switch(is_tar(bigbuff, bread)) {
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case 1:
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ret = CL_TYPE_OLD_TAR;
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cli_dbgmsg("Recognized old fashioned tar file\n");
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break;
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case 2:
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ret = CL_TYPE_POSIX_TAR;
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cli_dbgmsg("Recognized POSIX tar file\n");
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break;
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}
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}
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free(bigbuff);
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}
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return ret;
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}
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int cli_addtypesigs(struct cl_node *root)
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{
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int i, ret;
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for(i = 0; cli_smagic[i].sig; i++) {
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if((ret = cli_parse_add(root, cli_smagic[i].descr, cli_smagic[i].sig, cli_smagic[i].type, NULL, 0))) {
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cli_errmsg("cli_addtypesigs(): Problem adding signature for %s\n", cli_smagic[i].descr);
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return ret;
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}
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}
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return 0;
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}
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