tree 445bea0019805bc08fdba4e33eecbee8a6dd101a
parent cc12ab5951aa3a9d0893614120560179db8659a2
author Xin Long <lucien.xin@gmail.com> 1626471847 -0400
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1631965218 +0200

tipc: keep the skb in rcv queue until the whole data is read

[ Upstream commit f4919ff59c2828064b4156e3c3600a169909bcf4 ]

Currently, when userspace reads a datagram with a buffer that is
smaller than this datagram, the data will be truncated and only
part of it can be received by users. It doesn't seem right that
users don't know the datagram size and have to use a huge buffer
to read it to avoid the truncation.

This patch to fix it by keeping the skb in rcv queue until the
whole data is read by users. Only the last msg of the datagram
will be marked with MSG_EOR, just as TCP/SCTP does.

Note that this will work as above only when MSG_EOR is set in the
flags parameter of recvmsg(), so that it won't break any old user
applications.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Jon Maloy <jmaloy@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>