1)定義
#include <linux/proc_fs.h> /* Needed by proc entry */
int aegis_enable = 1;
2)宣告
static struct proc_dir_entry *entry_aegis_enable = NULL;
3)Kernel主體
/* read operation for /proc/net/aegis/aegis_enable entry */
ssize_t proc_aegis_enable_read(struct file *file, char *ubuf, size_t bytes, loff_t *pos)
{
char buf[16];
int len=0, rlen;
if(bytes < 0)
return -EINVAL;
if(bytes == 0)
return 0;
/*print message here*/
len += snprintf(buf + len, 16, "%d", aegis_enable);
if (*pos >= len)
return 0;
rlen = len - *pos;
if (rlen > bytes)
rlen = bytes;
if (copy_to_user(ubuf, buf + *pos, rlen))
return -EFAULT;
*pos += rlen;
return rlen;
}
/* write operation for /proc/net/aegis/aegis_enable entry */
ssize_t proc_aegis_enable_write(struct file *file, const char *buf, size_t bytes, loff_t *pos)
{
unsigned char tmp[16];
int tmpval = 0, retval = 0, i = 0;
memset(tmp, 0, 16);
if (bytes > 0) {
if (*pos == 0)
tmp[0]=0x00;
retval = copy_from_user(tmp + *pos, buf, bytes);
if (retval != 0) {
printk("proc_aegis_enable_write: copy_from_user() failed!\n");
return -EFAULT;
}
*pos += bytes;
tmp[*pos] = '\0';
for (i = 0; tmp[i] != 0; i++) {
if (tmp[i] >= '0' && tmp[i] <= '9')
tmpval = (tmpval * 10) + (tmp[i] - '0');
else /* Some other crap */
break;
}
aegis_enable = tmpval;
}
return bytes;
}
static struct file_operations aegis_enable_file_ops = {
read: proc_aegis_enable_read,
write: proc_aegis_enable_write,
};
4)在module_init的function裡
/* create /proc/net/aegis/aegis_enable entry*/
entry_aegis_enable = create_proc_entry ("aegis_enable", 0644, dir_aegis);
if (entry_aegis_enable) {
entry_aegis_enable->proc_fops = &aegis_enable_file_ops;
entry_aegis_enable->owner = THIS_MODULE;
}
5)在module_exit的function裡
remove_proc_entry("aegis_enable", dir_aegis);
6) 在userspace把PROC讀取出來
#define PROC_AEGIS_ENABLE_PATH "/proc/net/aegis/aegis_enable"
int get_DOS_status(void)
{
FILE *fp;
int i, c, dosEnable = 0;
char buf[32];
/* DOS_status check */
fp = fopen(PROC_AEGIS_ENABLE_PATH, "r");
if(fp != NULL){
c = fgetc(fp);
snprintf(buf, sizeof(buf), "%c", (char)c);
if(i < 32 && !feof(fp)){
fprintf(stderr, "DOS_Status error reading.\n");
}
fclose(fp);
}
else {
fprintf(stderr, "%s error opening.\n", PROC_AEGIS_ENABLE_PATH);
fclose(fp);
return -1;
}
dosEnable = atoi(buf);
return dosEnable;
}