From 749c08f8206cdf5cad15d557912898ce22aa55da Mon Sep 17 00:00:00 2001 From: Richard Sailer Date: Mon, 20 Jul 2020 18:06:14 +0200 Subject: [PATCH] net: dccp: Add SIOCOUTQ IOCTL support (send buffer fill) This adds support for the SIOCOUTQ IOCTL to get the send buffer fill of a DCCP socket, like UDP and TCP sockets already have. Regarding the used data field: DCCP uses per packet sequence numbers, not per byte, so sequence numbers can't be used like in TCP. sk_wmem_queued is not used by DCCP and always 0, even in test on highly congested paths. Therefore this uses sk_wmem_alloc like in UDP. Signed-off-by: Richard Sailer Signed-off-by: David S. Miller --- Documentation/networking/dccp.rst | 3 +++ net/dccp/proto.c | 9 +++++++++ 2 files changed, 12 insertions(+) diff --git a/Documentation/networking/dccp.rst b/Documentation/networking/dccp.rst index dde16be04456..91e5c33ba3ff 100644 --- a/Documentation/networking/dccp.rst +++ b/Documentation/networking/dccp.rst @@ -192,6 +192,9 @@ FIONREAD Works as in udp(7): returns in the ``int`` argument pointer the size of the next pending datagram in bytes, or 0 when no datagram is pending. +SIOCOUTQ + Returns the number of unsent data bytes in the socket send queue as ``int`` + into the buffer specified by the argument pointer. Other tunables ============== diff --git a/net/dccp/proto.c b/net/dccp/proto.c index fd92d3fe321f..9e453611107f 100644 --- a/net/dccp/proto.c +++ b/net/dccp/proto.c @@ -375,6 +375,15 @@ int dccp_ioctl(struct sock *sk, int cmd, unsigned long arg) goto out; switch (cmd) { + case SIOCOUTQ: { + int amount = sk_wmem_alloc_get(sk); + /* Using sk_wmem_alloc here because sk_wmem_queued is not used by DCCP and + * always 0, comparably to UDP. + */ + + rc = put_user(amount, (int __user *)arg); + } + break; case SIOCINQ: { struct sk_buff *skb; unsigned long amount = 0;