Commit 65040c33 authored by Diego Elio 'Flameeyes' Pettenò's avatar Diego Elio 'Flameeyes' Pettenò Committed by David S. Miller
Browse files

sctp: implement SIOCINQ ioctl() (take 3) 



This simple patch copies the current approach for SIOCINQ ioctl() from DCCP
into SCTP so that the userland code working with SCTP can use a similar
interface across different protocols to know how much space to allocate for
a buffer.

Signed-off-by: default avatarDiego Elio Pettenò <flameeyes@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2edae08e

net/sctp/socket.c

+34 −1
Original line number Diff line number Diff line
@@ -3592,7 +3592,40 @@ SCTP_STATIC struct sock *sctp_accept(struct sock *sk, int flags, int *err) 
/* The SCTP ioctl handler. */

SCTP_STATIC int sctp_ioctl(struct sock *sk, int cmd, unsigned long arg)

{

	return -ENOIOCTLCMD;

	int rc = -ENOTCONN;



	sctp_lock_sock(sk);



	/*

	 * SEQPACKET-style sockets in LISTENING state are valid, for

	 * SCTP, so only discard TCP-style sockets in LISTENING state.

	 */

	if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))

		goto out;



	switch (cmd) {

	case SIOCINQ: {

		struct sk_buff *skb;

		unsigned int amount = 0;



		skb = skb_peek(&sk->sk_receive_queue);

		if (skb != NULL) {

			/*

			 * We will only return the amount of this packet since

			 * that is all that will be read.

			 */

			amount = skb->len;

		}

		rc = put_user(amount, (int __user *)arg);

	}

		break;

	default:

		rc = -ENOIOCTLCMD;

		break;

	}

out:

	sctp_release_sock(sk);

	return rc;

}



/* This is the function which gets called during socket creation to