<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <!--Converted with LaTeX2HTML 2002-2-1 (1.71) original version by: Nikos Drakos, CBLU, University of Leeds * revised and updated by: Marcus Hennecke, Ross Moore, Herb Swan * with significant contributions from: Jens Lippmann, Marek Rouchal, Martin Wilck and others --> <HTML> <HEAD> <TITLE>Data scan functions</TITLE> <META NAME="description" CONTENT="Data scan functions"> <META NAME="keywords" CONTENT="clamdoc"> <META NAME="resource-type" CONTENT="document"> <META NAME="distribution" CONTENT="global"> <META NAME="Generator" CONTENT="LaTeX2HTML v2002-2-1"> <META HTTP-EQUIV="Content-Style-Type" CONTENT="text/css"> <LINK REL="STYLESHEET" HREF="clamdoc.css"> <LINK REL="next" HREF="node46.html"> <LINK REL="previous" HREF="node44.html"> <LINK REL="up" HREF="node44.html"> <LINK REL="next" HREF="node46.html"> </HEAD> <BODY > <DIV CLASS="navigation"><!--Navigation Panel--> <A NAME="tex2html788" HREF="node46.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next.png"></A> <A NAME="tex2html784" HREF="node44.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up.png"></A> <A NAME="tex2html778" HREF="node44.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="prev.png"></A> <A NAME="tex2html786" HREF="node1.html"> <IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="contents.png"></A> <BR> <B> Next:</B> <A NAME="tex2html789" HREF="node46.html">Memory</A> <B> Up:</B> <A NAME="tex2html785" HREF="node44.html">Database reloading</A> <B> Previous:</B> <A NAME="tex2html779" HREF="node44.html">Database reloading</A> <B> <A NAME="tex2html787" HREF="node1.html">Contents</A></B> <BR> <BR></DIV> <!--End of Navigation Panel--> <H3><A NAME="SECTION00074100000000000000"> Data scan functions</A> </H3> It's possible to scan a file or descriptor using: <PRE> int cl_scanfile(const char *filename, const char **virname, unsigned long int *scanned, const struct cl_engine *engine, const struct cl_limits *limits, unsigned int options); int cl_scandesc(int desc, const char **virname, unsigned long int *scanned, const struct cl_engine *engine, const struct cl_limits *limits, unsigned int options); </PRE> Both functions will store a virus name under the pointer <code>virname</code>, the virus name is part of the engine structure and must not be released directly. If the third argument (<code>scanned</code>) is not NULL, the functions will increase its value with the size of scanned data (in <code>CL_COUNT_PRECISION</code> units). Both functions have support for archive limits in order to protect against Denial of Service attacks. <PRE> struct cl_limits { unsigned long int maxscansize; /* during the scanning of archives this * size will never be exceeded */ unsigned long int maxfilesize; /* compressed files will only be * decompressed and scanned up to this size */ unsigned int maxreclevel; /* maximum recursion level for archives */ unsigned int maxfiles; /* maximum number of files to be scanned * within a single archive */ unsigned short archivememlim; /* limit memory usage for some unpackers */ }; </PRE> The last argument (<code>options</code>) configures the scan engine and supports the following flags (that can be combined using bit operators): <UL> <LI><SPAN CLASS="textbf">CL_SCAN_STDOPT</SPAN> <BR> This is an alias for a recommended set of scan options. You should use it to make your software ready for new features in the future versions of libclamav. </LI> <LI><SPAN CLASS="textbf">CL_SCAN_RAW</SPAN> <BR> Use it alone if you want to disable support for special files. </LI> <LI><SPAN CLASS="textbf">CL_SCAN_ARCHIVE</SPAN> <BR> This flag enables transparent scanning of various archive formats. </LI> <LI><SPAN CLASS="textbf">CL_SCAN_BLOCKENCRYPTED</SPAN> <BR> With this flag the library will mark encrypted archives as viruses (Encrypted.Zip, Encrypted.RAR). </LI> <LI><SPAN CLASS="textbf">CL_SCAN_MAIL</SPAN> <BR> Enable support for mail files. </LI> <LI><SPAN CLASS="textbf">CL_SCAN_MAILURL</SPAN> <BR> The mail scanner will download and scan URLs listed in a mail body. This flag should not be used on loaded servers. Due to potential problems please do not enable it by default but make it optional. </LI> <LI><SPAN CLASS="textbf">CL_SCAN_OLE2</SPAN> <BR> Enables support for OLE2 containers (used by MS Office and .msi files). </LI> <LI><SPAN CLASS="textbf">CL_SCAN_PDF</SPAN> <BR> Enables scanning within PDF files. </LI> <LI><SPAN CLASS="textbf">CL_SCAN_PE</SPAN> <BR> This flag enables deep scanning of Portable Executable files and allows libclamav to unpack executables compressed with run-time unpackers. </LI> <LI><SPAN CLASS="textbf">CL_SCAN_ELF</SPAN> <BR> Enable support for ELF files. </LI> <LI><SPAN CLASS="textbf">CL_SCAN_BLOCKBROKEN</SPAN> <BR> libclamav will try to detect broken executables and mark them as Broken.Executable. </LI> <LI><SPAN CLASS="textbf">CL_SCAN_HTML</SPAN> <BR> This flag enables HTML normalisation (including ScrEnc decryption). </LI> <LI><SPAN CLASS="textbf">CL_SCAN_ALGORITHMIC</SPAN> <BR> Enable algorithmic detection of viruses. </LI> <LI><SPAN CLASS="textbf">CL_SCAN_PHISHING_BLOCKSSL</SPAN> <BR> Phishing module: always block SSL mismatches in URLs. </LI> <LI><SPAN CLASS="textbf">CL_SCAN_PHISHING_BLOCKCLOAK</SPAN> <BR> Phishing module: always block cloaked URLs. </LI> </UL> All functions return 0 (<code>CL_CLEAN</code>) when the file seems clean, <code>CL_VIRUS</code> when a virus is detected and another value on failure. <PRE> ... struct cl_limits limits; const char *virname; memset(&limits, 0, sizeof(struct cl_limits)); limits.maxfiles = 10000; limits.maxscansize = 100 * 1048576; /* 100 MB */ limits.maxfilesize = 10 * 1048576; /* 10 MB */ limits.maxreclevel = 16; if((ret = cl_scanfile("/tmp/test.exe", &virname, NULL, engine, &limits, CL_STDOPT)) == CL_VIRUS) { printf("Virus detected: %s\n", virname); } else { printf("No virus detected.\n"); if(ret != CL_CLEAN) printf("Error: %s\n", cl_strerror(ret)); } </PRE> <P> <DIV CLASS="navigation"><HR> <!--Navigation Panel--> <A NAME="tex2html788" HREF="node46.html"> <IMG WIDTH="37" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="next" SRC="next.png"></A> <A NAME="tex2html784" HREF="node44.html"> <IMG WIDTH="26" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="up" SRC="up.png"></A> <A NAME="tex2html778" HREF="node44.html"> <IMG WIDTH="63" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="previous" SRC="prev.png"></A> <A NAME="tex2html786" HREF="node1.html"> <IMG WIDTH="65" HEIGHT="24" ALIGN="BOTTOM" BORDER="0" ALT="contents" SRC="contents.png"></A> <BR> <B> Next:</B> <A NAME="tex2html789" HREF="node46.html">Memory</A> <B> Up:</B> <A NAME="tex2html785" HREF="node44.html">Database reloading</A> <B> Previous:</B> <A NAME="tex2html779" HREF="node44.html">Database reloading</A> <B> <A NAME="tex2html787" HREF="node1.html">Contents</A></B> </DIV> <!--End of Navigation Panel--> <ADDRESS> Tomasz Kojm 2008-10-15 </ADDRESS> </BODY> </HTML>