Winpcap Study Notes (1)

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Note: this series of articles is a learning note prepared after I read the Winpcap manual. AllCodeI learned the sample code in the Winpcap manual and passed the debugging. I modified some of the code. I respect the copyright in the Winpcap manual, I am not liable for any copyright or security threats caused by using the code in this series.

Download wpdpack_3_2_alpha1.zip (: http://www.winpcap.org/install/bin/WpdPack_3_2_alpha1.zip), decompress in addition to the documentation, examples include and Lib, so I want to use TC2 for development environment, but the compilation always has a problem, so give up. Later, after reading the Winpcap manual, I learned that because it was developed on Windows, VC ++ 6.0 is recommended, so I switched to VC instead.

The first test is:

# Include
# Include

Int main (){
Pcap_if_t * alldevs;
Pcap_if_t * D;
Int I = 0;
Char errbuf [pcap_errbuf_size];

/* Retrieve the device list from the local machine */
If (pcap_findalldevs_ex (pcap_src_if_string, null/* auth is not needed */, & alldevs, errbuf) =-1)
{
Printf ("error in pcap_findalldevs_ex: % s/n", errbuf );
Exit (1 );
}

/* Print the list */
For (D = alldevs; D! = NULL; D = D-> next)
{
/* Print the device's name */
Printf ("% d. % s", ++ I, d-> name );

/* Print the device's dashboard */
If (D-> description)
{
Printf ("(% s)/n", D-> description );
}
Else
{
Printf ("(no description available)/n ");
}
}

If (I = 0)
{
Printf ("/Nno interfaces found! Make sure Winpcap is installed./N ");
Return 0;
}

/* We don't need any more the device list. Free It */
Pcap_freealldevs (alldevs );

Return 1;
}

Another problem occurs during compilation -- "pcap. h cannot be enabled ". Check the development manual to find the solution:

1. Install the Winpcap driver. : Http://www.winpcap.org/install/bin/winpcap_3_1.exe.

2. Add the include and Lib directories of Winpcap to the environment variables of vc6.0;

3. for each project, open the project with VC, and select "C/C ++" in "Project-> Settings ", add "wpcap" in the "Preprocessor definitions" input box, select "Link", and add "wpcap" in the "Object/library modules" input box. lib packet. lib ".

After compilation, the system is finally okay. After reading the code and reading the development manual, I learned the following:

Pcap_if is a struct. Its node is a linked list. Its definition is as follows:

Struct pcap_if {

Struct pcap_if * next;

Char * Name;

Char * description;

Struct pcap_addr * addresses;

U_int flags;

}

In pcap. h, there is a "typedef struct pcap_if pcap_if_t;", so you can also replace pcap_if_t with pcap_if.

Int pcap_findalldevs_ex (char * source,

Struct pcap_rmtauth * auth,

Pcap_if_t ** alldevs,

Char * errbuf

)

This function is a superset of 'pcap _ findalldevs. 'Pcap _ findalldevs () 'is old. It only allows listing devices on local machines. However, 'pcap _ findalldevs_ex () 'can not only list local devices but also devices on remote machines. In addition, it can list all available pcap files to the specified folder. 'Pcap _ findalldevs_ex () 'is platform independent. However, it has obtained the address of the local machine from the standard 'pcap _ findalldevs.
 

This article from China protocol analysis network | www.cnpaf.net Original article links: http://www.cnpaf.net/Class/winpcap/200610/16292.html