lwfw.h

/* Include file for the Light-weight Fire Wall LKM.
* 
* A very simple Netfilter module that drops backets based on either
* their incoming interface or source IP address.
* 
* Written by bioforge  -  March 2003
*/

#ifndef __LWFW_INCLUDE__
#define __LWFW_INCLUDE__

/* NOTE: The LWFW_MAJOR symbol is only made available for kernel code.
* Userspace code has no business knowing about it. */
# define LWFW_NAME        "lwfw" 

/* Version of LWFW */
# define LWFW_VERS        0x0001       /* 0.1 */

/* Definition of the LWFW_TALKATIVE symbol controls whether LWFW will
* print anything with printk(). This is included for debugging purposes.
*/
#define LWFW_TALKATIVE

/* These are the IOCTL codes used for the control device */
#define LWFW_CTRL_SET   0xFEED0000     /* The 0xFEED... prefix is arbitrary */
#define LWFW_GET_VERS   0xFEED0001     /* Get the version of LWFM */
#define LWFW_ACTIVATE   0xFEED0002
#define LWFW_DEACTIVATE 0xFEED0003
#define LWFW_GET_STATS  0xFEED0004
#define LWFW_DENY_IF    0xFEED0005
#define LWFW_DENY_IP    0xFEED0006
#define LWFW_DENY_PORT  0xFEED0007

/* Control flags/Options */
#define LWFW_IF_DENY_ACTIVE   0x00000001
#define LWFW_IP_DENY_ACTIVE   0x00000002
#define LWFW_PORT_DENY_ACTIVE 0x00000004

/* Statistics structure for LWFW.
* Note that whenever a rule's condition is changed the related
* xxx_dropped field is reset.
*/
struct lwfw_stats {
   unsigned int if_dropped;           /* Packets dropped by interface rule */
   unsigned int ip_dropped;           /* Packets dropped by IP addr. rule */
   unsigned int tcp_dropped;           /* Packets dropped by TCP port rule */
   unsigned long total_dropped;   /* Total packets dropped */
   unsigned long total_seen;      /* Total packets seen by filter */
};

/* 
* From here on is used solely for the actual kernel module
*/
# define LWFW_MAJOR       241   /* This exists in the experimental range */

/* This macro is used to prevent dereferencing of NULL pointers. If
* a pointer argument is NULL, this will return -EINVAL */
#define NULL_CHECK(ptr)    \
   if ((ptr) == NULL)  return -EINVAL

/* Macros for accessing options */
#define DENY_IF_ACTIVE    (lwfw_options & LWFW_IF_DENY_ACTIVE)
#define DENY_IP_ACTIVE    (lwfw_options & LWFW_IP_DENY_ACTIVE)
#define DENY_PORT_ACTIVE  (lwfw_options & LWFW_PORT_DENY_ACTIVE)

#endif