Return-Path: Subject: Re: [PATCH 8/9] Bluetooth: Use a stream-oriented recvmsg with SOCK_STREAM L2CAP sockets. From: Marcel Holtmann To: Mat Martineau Cc: linux-bluetooth@vger.kernel.org, gustavo@padovan.org, rshaffer@codeaurora.org, linux-arm-msm@vger.kernel.org In-Reply-To: <1281048867-32630-9-git-send-email-mathewm@codeaurora.org> References: <1281048867-32630-1-git-send-email-mathewm@codeaurora.org> <1281048867-32630-9-git-send-email-mathewm@codeaurora.org> Content-Type: text/plain; charset="UTF-8" Date: Sun, 08 Aug 2010 22:50:04 -0400 Message-ID: <1281322204.12579.188.camel@localhost.localdomain> Mime-Version: 1.0 Sender: linux-bluetooth-owner@vger.kernel.org List-ID: Hi Mat, > L2CAP ERTM sockets can be opened with the SOCK_STREAM socket type, > which is a mandatory request for ERTM mode. > > However, these sockets still have SOCK_SEQPACKET read semantics when > bt_sock_recvmsg() is used to pull data from the receive queue. If the > application is only reading part of a frame, then the unread portion > of the frame is discarded. If the application requests more bytes > than are in the current frame, only the current frame's data is > returned. > > This patch utilizes common code derived from RFCOMM's recvmsg() > function to make L2CAP SOCK_STREAM reads behave like RFCOMM reads (and > other SOCK_STREAM sockets in general). The application may read one > byte at a time from the input stream and not lose any data, and may > also read across L2CAP frame boundaries. > > Signed-off-by: Mat Martineau > --- > net/bluetooth/l2cap.c | 5 ++++- > 1 files changed, 4 insertions(+), 1 deletions(-) > > diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c > index 43e0eae..cd0e150 100644 > --- a/net/bluetooth/l2cap.c > +++ b/net/bluetooth/l2cap.c > @@ -1956,7 +1956,10 @@ static int l2cap_sock_recvmsg(struct kiocb *iocb, struct socket *sock, struct ms > > release_sock(sk); > > - return bt_sock_recvmsg(iocb, sock, msg, len, flags); > + if (sock->type == SOCK_STREAM) > + return bt_sock_stream_recvmsg(iocb, sock, msg, len, flags); > + else > + return bt_sock_recvmsg(iocb, sock, msg, len, flags); > } > > static int l2cap_sock_setsockopt_old(struct socket *sock, int optname, char __user *optval, unsigned int optlen) this is more a style issue, but I clearly prefer this: if (sock->type == SOCK_STREAM) return bt_sock_stream_recvmsg(iocb, sock, msg, len, flags); return bt_sock_recvmsg(iocb, sock, msg, len, flags); Regards Marcel