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如何更改ip頭中tos位的值？ 我試着用iphdr結構直接修改它。 它使用netfilter在內核級完成。 我寫的代碼如下：如何更改ip頭中的tos位而不會破壞頭
// Including the required header files
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv4.h>
#include <linux/init.h>
#include <linux/kthread.h>
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/wait.h>
#include <linux/types.h>
#include <linux/netdevice.h>
#include <linux/ip.h>
#include <linux/tcp.h>
#include <linux/in.h>
#include <linux/inet.h>
#include <linux/delay.h>
#include <linux/string.h>
#include <linux/socket.h>
#include <linux/net.h>
#include <net/sock.h>
#include <asm/processor.h>
#include <asm/uaccess.h>
#include <linux/file.h>
#include <linux/fs.h>
#include <linux/stat.h>
#include <linux/proc_fs.h>
// Defining the name of the module
#define MODULE_NAME "TOS_setter"
// Structure definition for processing outgoing packets
static struct nf_hook_ops nf_ops_out;
//===========================================================
// Function that modifies the TOS bits
unsigned int tos_setter(unsigned int hooknum,struct sk_buff *skb, const struct net_device *in,
const struct net_device *out,int (*okfn)(struct sk_buff*))
{
struct iphdr *iph;
unsigned char tosbits;
if (!skb)return NF_ACCEPT;
iph = ip_hdr(skb);
if (!iph)return NF_ACCEPT;
//if(iph->protocol==IPPROTO_TCP)return NF_ACCEPT;
if (iph->protocol==IPPROTO_TCP)
{
printk(KERN_ALERT " The total length is : %d\n" , (int)iph->tot_len);
iph->tos = tosbits | (unsigned char)2;
tosbits = iph->tos;
printk(KERN_ALERT " The tos bits are : %d\n" , (int)tosbits);
printk(KERN_ALERT " The total length is : %d\n" , (int)iph->tot_len);
}
return NF_ACCEPT;
}
//===========================================================
//Initialisation function
static int __init init(void){
printk(KERN_ALERT " Initialization Started \n");
// Initialize Hook Functions
nf_ops_out.hook = tos_setter;
nf_ops_out.pf = PF_INET;
nf_ops_out.hooknum =4;
nf_ops_out.priority = NF_IP_PRI_FIRST;
// Register the Hook functions
nf_register_hook(&nf_ops_out);
printk(KERN_ALERT "hook functions registered\n");
printk(KERN_ALERT " KSTAT Initialization Completed \n");
return 0;
}
static void __exit cleanup(void){
printk(KERN_ALERT "KSTAT Exit Started\n");
// Unregister the hook functions
nf_unregister_hook(&nf_ops_out);
printk("Unregistered the hooks\n");
printk(KERN_ALERT "KSTAT Exit Completed\n");
}
/* init and cleanup functions */
module_init(init);
module_exit(cleanup);
MODULE_LICENSE("GPL");
的問題是，當我嘗試改變TOS值的位我的Internet停止工作。 有沒有其他方式，或者如果有人能指出我做錯了什麼，這將是非常有益的。