Function Application Instances in list. h in Linux

These code snippets show how to use the Linux kernel module, list, and hash

============================= Tccounter. c ==================================

# Include <Linux/init. h>

# Include <Linux/module. h>

# Include <Linux/moduleparam. h>

# Include <Linux/list. h>

# Include <Linux/jhash. h>

# Include <Linux/ctype. h>

# Include <Linux/proc_fs.h>

# Include <ASM/uaccess. h>

Module_license ("GPL ");

Static unsigned int IP = 123456789;

Module_param (IP, uint, 0 );

Static unsigned int Port = 1;

Module_param (port, uint, 0 );

# Define tccount_size 255

Struct tccount

{

Struct list_head list;

Unsigned int IP address;

Unsigned short port;

Unsigned short counter;

};

Struct tccount tclist [tccount_size];

Unsigned int gethash (unsigned int IP, unsigned int port)

{

Return jhash_2words (IP, port, 4) % tccount_size;

}

Int tccount_init (void)

{

Int I;

For (I = 0; I <tccount_size; I ++)

{

Init_list_head (& (tclist [I]. List ));

Tclist [I]. IP = 0;

Tclist [I]. Port = 0;

Tclist [I]. Counter = 0;

}

Return 0;

}

Int addnewstream (unsigned int sip, unsigned int Sport)

{

Unsigned int hash;

Struct tccount * stream;

Hash = gethash (SIP, sport );

List_for_each_entry (stream, & (tclist [hash]. List), list)

{

If (Stream & stream-> IP = sip & stream-> Port = sport)

{

Stream-> counter ++;

Return 0;

}

}

Stream = kmalloc (sizeof (struct tccount), gfp_kernel );

Stream-> IP = sip;

Stream-> Port = sport;

Stream-> counter = 1;

List_add_rcu (& (Stream-> list), & (tclist [hash]. List ));

Return 0;

}

Int delstream (unsigned int sip, unsigned int Sport)

{

Unsigned int hash;

Struct tccount * stream;

Hash = gethash (SIP, sport );

List_for_each_entry (stream, & (tclist [hash]. List), list)

{

If (Stream-> IP = sip & stream-> Port = sport)

{

Stream-> counter --;

If (Stream-> counter = 0 & stream! = & Tclist [hash])

{

List_del_rcu (& (Stream-> List ));

Kfree (& stream );

}

}

}

Return 0;

}

Unsigned short getstreamcount (unsigned int sip, unsigned int Sport)

{

Unsigned int hash;

Struct tccount * stream;

Hash = gethash (SIP, sport );

List_for_each_entry (stream, & (tclist [hash]. List), list)

{

If (Stream-> IP = sip & stream-> Port = sport)

Return stream-> counter;

}

Return 0;

}

/* Debug proc */

Static int proc_show_tccount (struct file * F, const char * Buf, unsigned long CNT, void * Data)

{

Char input [32];

Int R;

Unsigned int IP address;

Unsigned int port;

Unsigned short count;

If (copy_from_user (input, Buf, CNT )! = 0)

Return-efault;

R = CNT;

Sscanf (input, "% u", & IP, & Port );

Count = getstreamcount (IP, Port );

Printk (kern_alert "(% d, % d) Counter: % u/N", IP, port, count );

Return CNT;

}

Static int proc_set_tccount (struct file * F, const char * Buf, unsigned long CNT, void * Data)

{

Char input [32];

Int R;

Unsigned int IP address;

Unsigned int port;

Unsigned int count;

If (copy_from_user (input, Buf, CNT )! = 0)

Return-efault;

R = CNT;

Sscanf (input, "% u", & IP, & Port );

Count = addnewstream (IP, Port );

Printk (kern_alert "(% d, % d) has been added/N", IP, Port );

Return CNT;

}

Static int proc_del_tccount (struct file * F, const char * Buf, unsigned long CNT, void * Data)

{

Char input [32];

Int R;

Unsigned int IP address;

Unsigned int port;

Unsigned int count;

If (copy_from_user (input, Buf, CNT )! = 0)

Return-efault;

R = CNT;

Sscanf (input, "% u", & IP, & Port );

Count = delstream (IP, Port );

Printk (kern_alert "a stream of (% d, % d) has been deleted/N", IP, Port );

Return CNT;

}

Static int proc_add (void)

{

Char TMP [32];

Struct proc_dir_entry * proc_tcctl, * pentry;

Sprintf (TMP, "tccount ");

Proc_tcctl = proc_mkdir (TMP, null );

Sprintf (TMP, "show ");

Pentry = create_proc_entry (TMP, 0644, proc_tcctl );

Pentry-> DATA = NULL;

Pentry-> read_proc = NULL;

Pentry-> write_proc = proc_show_tccount;

Pentry-> owner = this_module;

Sprintf (TMP, "Del ");

Pentry = create_proc_entry (TMP, 0644, proc_tcctl );

Pentry-> DATA = NULL;

Pentry-> read_proc = NULL;

Pentry-> write_proc = proc_del_tccount;

Pentry-> owner = this_module;

Sprintf (TMP, "add ");

Pentry = create_proc_entry (TMP, 0644, proc_tcctl );

Pentry-> DATA = NULL;

Pentry-> read_proc = NULL;

Pentry-> write_proc = proc_set_tccount;

Pentry-> owner = this_module;

Return 0;

}

Static int hello_init (void)

{

Tccount_init ();

Proc_add ();

Return 0;

}

Static void hello_exit (void)

{

Printk ("goodbye! /N ");

}

Module_init (hello_init );

Module_exit (hello_exit );

================================= Makefile ======================== =====

 

OBJ-M + = tccounter. o

ALL:

Make-C/lib/modules/$ (shell uname-R)/build M = $ (PWD) Modules

Clean:

Make-C/lib/modules/$ (shell uname-R)/build M = $ (PWD) clean

=============================== Debug Method ======================== ==== echo 8>/proc/sys/kernel/printkecho 1234234123 123>/proc/tccount/showecho 1234234123 123>/proc/tccount/addecho 1234234123 123>/proc/tccount /del