指向从“struct net *"分配给“u32"(又名“unsigned int")的整数转换的不兼容指针 [英] Incompatible pointer to integer conversion assigning to 'u32' (aka 'unsigned int') from 'struct net *'

问题描述

我想要的:

向 execsnoop bcc 工具添加网络命名空间选项，以仅跟踪具有指定网络命名空间的日志，就像我们在许多其他 bcc 工具中具有过滤器 PID 选项一样.例如:execsnoop -N "ns_id"

To add a network namespace option to execsnoop bcc tool to trace only the logs with specified network namespace just like we have filter PID option in many other bcc tools. For eg: execsnoop -N "ns_id"

我正在使用 linux 内核结构来检索名称空间 ID net = task->nsproxy->net_ns; 并且需要将检索到的 ns 分配给 data.netns这是 u32 int.

I am using linux kernel structures to retrieve namespace id net = task->nsproxy->net_ns; and need to assign the retrieved ns to data.netns which is u32 int.

我在做什么:

int syscall__execve(struct pt_regs *ctx,
    const char __user *filename,
    const char __user *const __user *__argv,
    const char __user *const __user *__envp)
{
    // create data here and pass to submit_arg to save stack space (#555)
    //int ret = PT_REGS_RC(ctx);
    struct data_t data = {};
    struct task_struct *task;
    struct nsproxy *nsproxy;
    struct net *net;
    //struct mnt_namespace *mnt_ns;

    data.pid = bpf_get_current_pid_tgid() >> 32;

    u32 net_ns_inum = 0;
    //net = (struct net *)get_net_ns_by_pid(data.pid); //
       //net_ns_inum = (uintptr_t)net;


    task = (struct task_struct *)bpf_get_current_task();
    // Some kernels, like Ubuntu 4.13.0-generic, return 0
    // as the real_parent->tgid.
    // We use the get_ppid function as a fallback in those cases. (#1883)

    data.ppid = task->real_parent->tgid;

    net = task->nsproxy->net_ns;
    FILTER_NETNS

    data.netns =  (uintptr_t)net; //here have to perform casting

我添加了 #include </usr/include/stdint.h> 但得到 警告 尽管 include 存在于 stdint.h 文件中:

I have added #include </usr/include/stdint.h> but getting the warning though include <bits/libc-header-start.h> is present in stdint.h file:

In file included from /virtual/main.c:8:
/usr/include/stdint.h:26:10: fatal error: 'bits/libc-header-start.h' file not found
#include <bits/libc-header-start.h>
         ^~~~~~~~~~~~~~~~~~~~~~~~~~

如果我解决了这个错误，它会继续生成其他丢失的头文件错误.

and it keeps on generating other missing header files error if I resolve this one.

推荐答案

我已经解决了这个问题:

I have resolved this issue:

我没有使用 net = task->nsproxy->net_ns; 我使用了 net = task->nsproxy->net_ns->ns.inum;code> 是 unsigned int，我们可以直接从中检索命名空间.

Instead of using net = task->nsproxy->net_ns; I used net = task->nsproxy->net_ns->ns.inum; which is unsigned int and we can directly retrieve namespace from it.

这个结构可以在头文件中找到.

This structure can be found in <linux/ns_common.h> header file.

struct ns_common {
    atomic_long_t stashed;
    const struct proc_ns_operations *ops;
    unsigned int inum;
};

要获得在 execsnoop 工具中添加命名空间选项的修改代码，请点击此链接:https://github.com/Sheenam3/ebpf/blob/master/execsnoop.py#L143

To get a modified code with added namespace option in execsnoop tool, please follow this link: https://github.com/Sheenam3/ebpf/blob/master/execsnoop.py#L143

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