Re: Getting IP address and port of a file descriptor

[Cong Wang]

On Mon, Jul 18, 2016 at 12:09 PM, Peter Chen
 wrote:
> Hi,
>
>I was wondering, if I was in the kernel, and I intercepted a system
> call such as read(). Would I be able, from the fd, determine the
> whether the fd is (1) a network socket? (2) the IP address and port of
> this socket? What are the kernel data structures and functions that
> can get these information for me in the kernel? Thanks.

You can use sockfd_lookup() to read the sock structure from a given fd,
after than you can call, for example, sock->ops->getname() to read
local IP address etc.

Getting IP address and port of a file descriptor

[Peter Chen]

Hi,

   I was wondering, if I was in the kernel, and I intercepted a system
call such as read(). Would I be able, from the fd, determine the
whether the fd is (1) a network socket? (2) the IP address and port of
this socket? What are the kernel data structures and functions that
can get these information for me in the kernel? Thanks.

Peter