Re: socket and device relation.

[Shine Mohamed <shinemohamed_j@naturesoft.net>]

Hi Guillaume Thouvenin,

Just check my comments. If there is any mistake please 
correct me.

On Friday 05 December 2003 17:44, Guillaume Thouvenin wrote:
> > I'm trying to understant exactly where network driver is involved during
> > the connection. So I start with a user program which do the following
> > things: socket, bind, listen and accept. This is now what I understand:
> >
> > - socket() called sys_socket()
> > - sys_socket()
> >    -> sock_create()
>
> Ooops, it seems that my mail was posted before I finished my question. So I
> rewrite it.
>
>    I'm trying to understant exactly where network driver is involved during
> the connection. So I start with a user program which do the following
> things: socket, bind, listen and accept. This is what I understand:
>
> call to socket cause a syscall to sys_socketcall which call:
> - sys_socket()
>    -> sock_create()
>       * check protocol
>       * sock_alloc()
>          allocate a new inode and a new socket object

missing an important function call here( I'm refer linux-2.4.20-8)
    902         if ((i = net_families[family]->create(sock, protocol)) < 0)
    ====> net_families[family]->create()

In that protocol specific function (net_families[family]->create) the 
sock->ops is initialized.
Eg :- inet_create function in SRC/net/ipv4/af_inet.c for ipv4 protocol.
    360         sock->ops = answer->ops;

>    -> sock_map_fd()
>       * map the socket to a file descriptor
>
> So during the creation of the socket the driver is not involved.
> Now there is the binding:
>
> - sys_bind()
>    * Just bind the name and the socket
>
> At this point there something that I don't understand:
> There is a call to
> sock->ops->bind(sock, (struct sockaddr *)address, addrlen);
>
> but I don't see where sock->ops is initialized and thus, I don't find
> the function bind. Is the binding involving the network driver.
>
> Thank you for help


Regards,
Shine Mohamed

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