Question

我们有2.6内核的netfilter内核模块，现在移植到4.1.23。我的钩子功能看起来很破碎我无法检索数据包标题。

这是2.6内核的代码片段。这是长期生产。

def convert(snippet, phrase):
    class_names = [w.capitalize() for w in random.sample(WORDS, snippet.count("%%%"))]
    other_names = random.sample(WORDS, snippet.count("***"))
    class_names = [name.decode('UTF-8') for name in class_names]
    other_names = [name.decode('UTF-8') for name in other_names]

检查netfilter.h并搜索Internet以获得4.1.23中的以下内容

    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;

注册挂钩如下。

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;

我没有从saddr和daddr获得源ip和目标ip。

删除了所有内容并尝试了

  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);

结果如下

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;

也试过以下但是得到了垃圾

[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

我尝试使用函数来获取数据（skb_network_header），甚至尝试编写hello world。请帮忙。

Netfilter内核模块迁移到4.1.23 - 无法检索ip头

0 个答案: