[TCP]: Splice receive support.
Support for network splice receive.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 8e65182..56ed407 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -254,6 +254,10 @@
#include <linux/poll.h>
#include <linux/init.h>
#include <linux/fs.h>
+#include <linux/skbuff.h>
+#include <linux/splice.h>
+#include <linux/net.h>
+#include <linux/socket.h>
#include <linux/random.h>
#include <linux/bootmem.h>
#include <linux/cache.h>
@@ -265,6 +269,7 @@
#include <net/xfrm.h>
#include <net/ip.h>
#include <net/netdma.h>
+#include <net/sock.h>
#include <asm/uaccess.h>
#include <asm/ioctls.h>
@@ -292,6 +297,15 @@
EXPORT_SYMBOL(tcp_sockets_allocated);
/*
+ * TCP splice context
+ */
+struct tcp_splice_state {
+ struct pipe_inode_info *pipe;
+ size_t len;
+ unsigned int flags;
+};
+
+/*
* Pressure flag: try to collapse.
* Technical note: it is used by multiple contexts non atomically.
* All the sk_stream_mem_schedule() is of this nature: accounting
@@ -501,6 +515,120 @@
}
}
+int tcp_splice_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
+ unsigned int offset, size_t len)
+{
+ struct tcp_splice_state *tss = rd_desc->arg.data;
+
+ return skb_splice_bits(skb, offset, tss->pipe, tss->len, tss->flags);
+}
+
+static int __tcp_splice_read(struct sock *sk, struct tcp_splice_state *tss)
+{
+ /* Store TCP splice context information in read_descriptor_t. */
+ read_descriptor_t rd_desc = {
+ .arg.data = tss,
+ };
+
+ return tcp_read_sock(sk, &rd_desc, tcp_splice_data_recv);
+}
+
+/**
+ * tcp_splice_read - splice data from TCP socket to a pipe
+ * @sock: socket to splice from
+ * @ppos: position (not valid)
+ * @pipe: pipe to splice to
+ * @len: number of bytes to splice
+ * @flags: splice modifier flags
+ *
+ * Description:
+ * Will read pages from given socket and fill them into a pipe.
+ *
+ **/
+ssize_t tcp_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 tcp_splice_state tss = {
+ .pipe = pipe,
+ .len = len,
+ .flags = flags,
+ };
+ long timeo;
+ ssize_t spliced;
+ int ret;
+
+ /*
+ * We can't seek on a socket input
+ */
+ if (unlikely(*ppos))
+ return -ESPIPE;
+
+ ret = spliced = 0;
+
+ lock_sock(sk);
+
+ timeo = sock_rcvtimeo(sk, flags & SPLICE_F_NONBLOCK);
+ while (tss.len) {
+ ret = __tcp_splice_read(sk, &tss);
+ if (ret < 0)
+ break;
+ else if (!ret) {
+ if (spliced)
+ break;
+ if (flags & SPLICE_F_NONBLOCK) {
+ ret = -EAGAIN;
+ break;
+ }
+ if (sock_flag(sk, SOCK_DONE))
+ break;
+ if (sk->sk_err) {
+ ret = sock_error(sk);
+ break;
+ }
+ if (sk->sk_shutdown & RCV_SHUTDOWN)
+ break;
+ if (sk->sk_state == TCP_CLOSE) {
+ /*
+ * This occurs when user tries to read
+ * from never connected socket.
+ */
+ if (!sock_flag(sk, SOCK_DONE))
+ ret = -ENOTCONN;
+ break;
+ }
+ if (!timeo) {
+ ret = -EAGAIN;
+ break;
+ }
+ sk_wait_data(sk, &timeo);
+ if (signal_pending(current)) {
+ ret = sock_intr_errno(timeo);
+ break;
+ }
+ continue;
+ }
+ tss.len -= ret;
+ spliced += ret;
+
+ release_sock(sk);
+ lock_sock(sk);
+
+ if (sk->sk_err || sk->sk_state == TCP_CLOSE ||
+ (sk->sk_shutdown & RCV_SHUTDOWN) || !timeo ||
+ signal_pending(current))
+ break;
+ }
+
+ release_sock(sk);
+
+ if (spliced)
+ return spliced;
+
+ return ret;
+}
+
static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffset,
size_t psize, int flags)
{
@@ -2532,6 +2660,7 @@
EXPORT_SYMBOL(tcp_read_sock);
EXPORT_SYMBOL(tcp_recvmsg);
EXPORT_SYMBOL(tcp_sendmsg);
+EXPORT_SYMBOL(tcp_splice_read);
EXPORT_SYMBOL(tcp_sendpage);
EXPORT_SYMBOL(tcp_setsockopt);
EXPORT_SYMBOL(tcp_shutdown);