Subject: Re: [PATCH] linux 2.9.10-rc1: Fix oops in unix_dgram_sendmsg when using SELinux and SOCK_SEQPACKET

From: Ross Kendall Axe <[email-masked]>
Date: Fri, 19 Nov 2004 03:23:50 +0000

Chris Wright wrote:
> 
> Why not make a unix_seq_sendmsg, which is a very small wrapper?
> e.g.
> static int unix_seq_sendmsg(struct kiocb *kiocb, struct socket *sock,
> 			    struct msghdr *msg, size_t len)
> {
> 	struct sock *sk = sock->sk;
> 
> 	if (sk->sk_type == SOCK_SEQPACKET && sk->sk_state != TCP_ESTABLISHED)
> 		return -ENOTCONN;
> 	if (msg->msg_name || msg->msg_namelen)
> 		return -EINVAL;
> 	return unix_dgram_sendmsg(kiocb, sock, msg, len);
> }
> 
> 
> -chris

Taking this idea further, couldn't we split unix_dgram_sendmsg into 2 
functions, do_unix_dgram_sendmsg and do_unix_connectionless_sendmsg (and 
similarly for unix_stream_sendmsg), then all we'd need is:

<pseudocode>
static int do_unix_dgram_sendmsg(...);
static int do_unix_stream_sendmsg(...);
static int do_unix_connectionless_sendmsg(...);
static int do_unix_connectional_sendmsg(...);

static int unix_dgram_sendmsg(struct kiocb *kiocb, struct socket *sock,
			      struct msghdr *msg, size_t len)
{
	return do_unix_connectionless_sendmsg(kiocb, sock, msg, len,
					      do_unix_dgram_sendmsg);
}
static int unix_stream_sendmsg(struct kiocb *kiocb, struct socket *sock,
			       struct msghdr *msg, size_t len)
{
	return do_unix_connectional_sendmsg(kiocb, sock, msg, len,
					    do_unix_stream_sendmsg);
}
static int unix_seqpacket_sendmsg(struct kiocb *kiocb, struct socket *sock,
				  struct msghdr *msg, size_t len)
{
	return do_unix_connectional_sendmsg(kiocb, sock, msg, len,
					    do_unix_dgram_sendmsg);
}
</pseudocode>

What do we think?

Ross