【IT168 服务器学院】----[ A.3 - 头文件 : lwfw.h

　　<++> lwfw/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
　　*/
　　#ifdef __KERNEL__
　　# 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                       /* __KERNEL__ */
　　#endif
　　<-->

　　<++> lwfw/Makefile
　　CC= egcs
　　CFLAGS= -Wall -O2
　　OBJS= lwfw.o

　　.c.o:
　　$(CC) -c $< -o $@ $(CFLAGS)

　　all: $(OBJS)

　　clean:
　　rm -rf *.o
　　rm -rf ./*~
　　<-->