2017-04-24 112 views
1

我們有一個2.6內核的netfilter內核模塊,現在移植到4.1.23。我的鉤子功能看起來破碎。我無法檢索數據包標題。Netfilter內核模塊遷移到4.1.23 - 無法檢索IP標頭

這是2.6內核的代碼片段。這是長時間的生產。

static unsigned int main_hook(unsigned int hooknum, struct sk_buff *skb, const struct net_device *in,const struct net_device *out, int (*okfn)(struct sk_buff*)) 
{ 
    //struct sk_buff *skb = (skb_p); 
    struct iphdr *ih = (struct iphdr *)(skb->data); 
    u32 saddr = ih->saddr; 
    u32 daddr = ih->daddr; 

經過netfilter.h中搜查互聯網在4.1.23

static unsigned int main_hook(const struct nf_hook_ops *ops, struct sk_buff *skb, const struct nf_hook_state *state) 
     { 
      //struct sk_buff *skb = (skb_p); 
      struct iphdr *ih = (struct iphdr *)(skb->data); 
      u32 saddr = ih->saddr; 
      u32 daddr = ih->daddr; 

註冊鉤以下如下到達。

netfilter_ops.hook    =  main_hook; 
    netfilter_ops.pf    =  PF_INET; 
    netfilter_ops.hooknum   =  NF_INET_FORWARD; 
    netfilter_ops.priority   =  NF_IP_PRI_FIRST; 
    netfilter_ops.owner    =  THIS_MODULE; 
    nf_register_hook(&netfilter_ops); 

我沒有從saddr和daddr獲取源IP和目標IP。

刪除一切並嘗試以下

static unsigned int main_hook(const struct nf_hook_ops *ops, struct sk_buff *skb, const struct nf_hook_state *state) 
{ 
    struct iphdr *ip_header = (struct iphdr *) (skb->data); 
    unsigned int src_ip = (unsigned int)ip_header->saddr; 
    unsigned int dest_ip = (unsigned int)ip_header->daddr; 
    printk("IP addres = %pI4 DEST = %pI4\n", &src_ip, &dest_ip); 
    return NF_ACCEPT; 

下面是結果

[37501.345997] IP addres = 0.0.0.0 DEST = 0.0.0.0 
[37506.337854] IP addres = 0.0.0.0 DEST = 0.0.0.0 
[37511.345295] IP addres = 0.0.0.0 DEST = 0.0.0.0 
[37516.337132] IP addres = 0.0.0.0 DEST = 0.0.0.0 
[37521.344589] IP addres = 0.0.0.0 DEST = 0.0.0.0 
[37526.336426] IP addres = 0.0.0.0 DEST = 0.0.0.0 
[37531.343866] IP addres = 0.0.0.0 DEST = 0.0.0.0 

嘗試以下過,但得到的垃圾

buff = (unsigned char *) skb->data; 
for (i=0;i<60;i++) printk("%d.", buff[i]); 
printk("\n"); 

我試着用函數來獲得數據(skb_network_header) ,甚至嘗試寫出你好的世界。 請幫忙。

回答

1

嘗試提取物是這樣的:

struct iphdr *ip_hdr = (struct iphdr *)skb_network_header(skb); 

和訪問是這樣的:

printk("IP addres = %u DEST = %u\n", ip_hdr->saddr, ip_hdr->daddr);