[PATCH] sctp: implement SIOCINQ ioctl() (take 2)
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From: Diego Elio 'Flameeyes' Pettenò on 24 Jun 2010 10:30 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. --- net/sctp/socket.c | 35 ++++++++++++++++++++++++++++++++++- 1 files changed, 34 insertions(+), 1 deletions(-) diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 44a1ab0..f339383 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -3595,7 +3595,40 @@ out: /* 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 long 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 -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |