From dcda138d2f27e32bd0d6250cc42839b0d70bb4b8 Mon Sep 17 00:00:00 2001 From: Sjur Braendeland Date: Fri, 21 May 2010 02:16:12 +0000 Subject: caif: Bugfix - use MSG_TRUNC in receive Fixed handling when skb don't fit in user buffer, instead of returning -EMSGSIZE, the buffer is truncated (just as unix seqpakcet does). Signed-off-by: Sjur Braendeland Signed-off-by: David S. Miller --- net/caif/caif_socket.c | 47 ++++++++++++++++++----------------------------- 1 file changed, 18 insertions(+), 29 deletions(-) (limited to 'net/caif') diff --git a/net/caif/caif_socket.c b/net/caif/caif_socket.c index 691a571..3d0e095 100644 --- a/net/caif/caif_socket.c +++ b/net/caif/caif_socket.c @@ -292,53 +292,42 @@ static void caif_check_flow_release(struct sock *sk) caif_flow_ctrl(sk, CAIF_MODEMCMD_FLOW_ON_REQ); } } + /* - * Copied from sock.c:sock_queue_rcv_skb(), and added check that user buffer - * has sufficient size. + * Copied from unix_dgram_recvmsg, but removed credit checks, + * changed locking, address handling and added MSG_TRUNC. */ - static int caif_seqpkt_recvmsg(struct kiocb *iocb, struct socket *sock, - struct msghdr *m, size_t buf_len, int flags) + struct msghdr *m, size_t len, int flags) { struct sock *sk = sock->sk; struct sk_buff *skb; - int ret = 0; - int len; + int ret; + int copylen; - if (unlikely(!buf_len)) - return -EINVAL; + ret = -EOPNOTSUPP; + if (m->msg_flags&MSG_OOB) + goto read_error; skb = skb_recv_datagram(sk, flags, 0 , &ret); if (!skb) goto read_error; - - len = skb->len; - - if (skb && skb->len > buf_len && !(flags & MSG_PEEK)) { - len = buf_len; - /* - * Push skb back on receive queue if buffer too small. - * This has a built-in race where multi-threaded receive - * may get packet in wrong order, but multiple read does - * not really guarantee ordered delivery anyway. - * Let's optimize for speed without taking locks. - */ - - skb_queue_head(&sk->sk_receive_queue, skb); - ret = -EMSGSIZE; - goto read_error; + copylen = skb->len; + if (len < copylen) { + m->msg_flags |= MSG_TRUNC; + copylen = len; } - ret = skb_copy_datagram_iovec(skb, 0, m->msg_iov, len); + ret = skb_copy_datagram_iovec(skb, 0, m->msg_iov, copylen); if (ret) - goto read_error; + goto out_free; + ret = (flags & MSG_TRUNC) ? skb->len : copylen; +out_free: skb_free_datagram(sk, skb); - caif_check_flow_release(sk); - - return len; + return ret; read_error: return ret; -- cgit v1.1