From 91687355b92735e5f247ed163b3b0b4d14c3cab6 Mon Sep 17 00:00:00 2001 From: Tom Herbert Date: Mon, 7 Mar 2016 14:11:08 -0800 Subject: [PATCH] kcm: Splice support Implement kcm_splice_read. This is supported only for seqpacket. Add kcm_seqpacket_ops and set splice read to kcm_splice_read. Signed-off-by: Tom Herbert Signed-off-by: David S. Miller --- net/kcm/kcmsock.c | 98 ++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 96 insertions(+), 2 deletions(-) diff --git a/net/kcm/kcmsock.c b/net/kcm/kcmsock.c index f938d7d3e6e2..982ea5f77bfc 100644 --- a/net/kcm/kcmsock.c +++ b/net/kcm/kcmsock.c @@ -1256,6 +1256,76 @@ out: return copied ? : err; } +static ssize_t kcm_sock_splice(struct sock *sk, + struct pipe_inode_info *pipe, + struct splice_pipe_desc *spd) +{ + int ret; + + release_sock(sk); + ret = splice_to_pipe(pipe, spd); + lock_sock(sk); + + return ret; +} + +static ssize_t kcm_splice_read(struct socket *sock, loff_t *ppos, + struct pipe_inode_info *pipe, size_t len, + unsigned int flags) +{ + struct sock *sk = sock->sk; + struct kcm_sock *kcm = kcm_sk(sk); + long timeo; + struct kcm_rx_msg *rxm; + int err = 0; + size_t copied; + struct sk_buff *skb; + + /* Only support splice for SOCKSEQPACKET */ + + timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); + + lock_sock(sk); + + skb = kcm_wait_data(sk, flags, timeo, &err); + if (!skb) + goto err_out; + + /* Okay, have a message on the receive queue */ + + rxm = kcm_rx_msg(skb); + + if (len > rxm->full_len) + len = rxm->full_len; + + copied = skb_splice_bits(skb, sk, rxm->offset, pipe, len, flags, + kcm_sock_splice); + if (copied < 0) { + err = copied; + goto err_out; + } + + KCM_STATS_ADD(kcm->stats.rx_bytes, copied); + + rxm->offset += copied; + rxm->full_len -= copied; + + /* We have no way to return MSG_EOR. If all the bytes have been + * read we still leave the message in the receive socket buffer. + * A subsequent recvmsg needs to be done to return MSG_EOR and + * finish reading the message. + */ + + release_sock(sk); + + return copied; + +err_out: + release_sock(sk); + + return err; +} + /* kcm sock lock held */ static void kcm_recv_disable(struct kcm_sock *kcm) { @@ -1907,7 +1977,7 @@ static int kcm_release(struct socket *sock) return 0; } -static const struct proto_ops kcm_ops = { +static const struct proto_ops kcm_dgram_ops = { .family = PF_KCM, .owner = THIS_MODULE, .release = kcm_release, @@ -1928,6 +1998,28 @@ static const struct proto_ops kcm_ops = { .sendpage = sock_no_sendpage, }; +static const struct proto_ops kcm_seqpacket_ops = { + .family = PF_KCM, + .owner = THIS_MODULE, + .release = kcm_release, + .bind = sock_no_bind, + .connect = sock_no_connect, + .socketpair = sock_no_socketpair, + .accept = sock_no_accept, + .getname = sock_no_getname, + .poll = datagram_poll, + .ioctl = kcm_ioctl, + .listen = sock_no_listen, + .shutdown = sock_no_shutdown, + .setsockopt = kcm_setsockopt, + .getsockopt = kcm_getsockopt, + .sendmsg = kcm_sendmsg, + .recvmsg = kcm_recvmsg, + .mmap = sock_no_mmap, + .sendpage = sock_no_sendpage, + .splice_read = kcm_splice_read, +}; + /* Create proto operation for kcm sockets */ static int kcm_create(struct net *net, struct socket *sock, int protocol, int kern) @@ -1938,8 +2030,10 @@ static int kcm_create(struct net *net, struct socket *sock, switch (sock->type) { case SOCK_DGRAM: + sock->ops = &kcm_dgram_ops; + break; case SOCK_SEQPACKET: - sock->ops = &kcm_ops; + sock->ops = &kcm_seqpacket_ops; break; default: return -ESOCKTNOSUPPORT; -- 2.20.1