1 files changed, 204 insertions, 19 deletions

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 8e65182..a0d373b 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>
@@ -292,9 +297,18 @@ EXPORT_SYMBOL(tcp_memory_allocated);
 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
+ * All the __sk_mem_schedule() is of this nature: accounting
  * is strict, actions are advisory and have some latency.
  */
 int tcp_memory_pressure __read_mostly;
@@ -471,7 +485,8 @@ static inline void skb_entail(struct sock *sk, struct sk_buff *skb)
 	tcb->sacked  = 0;
 	skb_header_release(skb);
 	tcp_add_write_queue_tail(sk, skb);
-	sk_charge_skb(sk, skb);
+	sk->sk_wmem_queued += skb->truesize;
+	sk_mem_charge(sk, skb->truesize);
 	if (tp->nonagle & TCP_NAGLE_PUSH)
 		tp->nonagle &= ~TCP_NAGLE_PUSH;
 }
@@ -482,7 +497,6 @@ static inline void tcp_mark_urg(struct tcp_sock *tp, int flags,
 	if (flags & MSG_OOB) {
 		tp->urg_mode = 1;
 		tp->snd_up = tp->write_seq;
-		TCP_SKB_CB(skb)->sacked |= TCPCB_URG;
 	}
 }
 
@@ -501,6 +515,145 @@ static inline void tcp_push(struct sock *sk, int flags, int mss_now,
 	}
 }
 
+static 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;
+}
+
+struct sk_buff *sk_stream_alloc_skb(struct sock *sk, int size, gfp_t gfp)
+{
+	struct sk_buff *skb;
+
+	/* The TCP header must be at least 32-bit aligned.  */
+	size = ALIGN(size, 4);
+
+	skb = alloc_skb_fclone(size + sk->sk_prot->max_header, gfp);
+	if (skb) {
+		if (sk_wmem_schedule(sk, skb->truesize)) {
+			/*
+			 * Make sure that we have exactly size bytes
+			 * available to the caller, no more, no less.
+			 */
+			skb_reserve(skb, skb_tailroom(skb) - size);
+			return skb;
+		}
+		__kfree_skb(skb);
+	} else {
+		sk->sk_prot->enter_memory_pressure();
+		sk_stream_moderate_sndbuf(sk);
+	}
+	return NULL;
+}
+
 static ssize_t do_tcp_sendpages(struct sock *sk, struct page **pages, int poffset,
 			 size_t psize, int flags)
 {
@@ -537,8 +690,7 @@ new_segment:
 			if (!sk_stream_memory_free(sk))
 				goto wait_for_sndbuf;
 
-			skb = sk_stream_alloc_pskb(sk, 0, 0,
-						   sk->sk_allocation);
+			skb = sk_stream_alloc_skb(sk, 0, sk->sk_allocation);
 			if (!skb)
 				goto wait_for_memory;
 
@@ -555,7 +707,7 @@ new_segment:
 			tcp_mark_push(tp, skb);
 			goto new_segment;
 		}
-		if (!sk_stream_wmem_schedule(sk, copy))
+		if (!sk_wmem_schedule(sk, copy))
 			goto wait_for_memory;
 
 		if (can_coalesce) {
@@ -569,7 +721,7 @@ new_segment:
 		skb->data_len += copy;
 		skb->truesize += copy;
 		sk->sk_wmem_queued += copy;
-		sk->sk_forward_alloc -= copy;
+		sk_mem_charge(sk, copy);
 		skb->ip_summed = CHECKSUM_PARTIAL;
 		tp->write_seq += copy;
 		TCP_SKB_CB(skb)->end_seq += copy;
@@ -718,8 +870,8 @@ new_segment:
 				if (!sk_stream_memory_free(sk))
 					goto wait_for_sndbuf;
 
-				skb = sk_stream_alloc_pskb(sk, select_size(sk),
-							   0, sk->sk_allocation);
+				skb = sk_stream_alloc_skb(sk, select_size(sk),
+						sk->sk_allocation);
 				if (!skb)
 					goto wait_for_memory;
 
@@ -776,7 +928,7 @@ new_segment:
 				if (copy > PAGE_SIZE - off)
 					copy = PAGE_SIZE - off;
 
-				if (!sk_stream_wmem_schedule(sk, copy))
+				if (!sk_wmem_schedule(sk, copy))
 					goto wait_for_memory;
 
 				if (!page) {
@@ -867,7 +1019,7 @@ do_fault:
 		 * reset, where we can be unlinking the send_head.
 		 */
 		tcp_check_send_head(sk, skb);
-		sk_stream_free_skb(sk, skb);
+		sk_wmem_free_skb(sk, skb);
 	}
 
 do_error:
@@ -1500,6 +1652,41 @@ recv_urg:
 	goto out;
 }
 
+void tcp_set_state(struct sock *sk, int state)
+{
+	int oldstate = sk->sk_state;
+
+	switch (state) {
+	case TCP_ESTABLISHED:
+		if (oldstate != TCP_ESTABLISHED)
+			TCP_INC_STATS(TCP_MIB_CURRESTAB);
+		break;
+
+	case TCP_CLOSE:
+		if (oldstate == TCP_CLOSE_WAIT || oldstate == TCP_ESTABLISHED)
+			TCP_INC_STATS(TCP_MIB_ESTABRESETS);
+
+		sk->sk_prot->unhash(sk);
+		if (inet_csk(sk)->icsk_bind_hash &&
+		    !(sk->sk_userlocks & SOCK_BINDPORT_LOCK))
+			inet_put_port(&tcp_hashinfo, sk);
+		/* fall through */
+	default:
+		if (oldstate==TCP_ESTABLISHED)
+			TCP_DEC_STATS(TCP_MIB_CURRESTAB);
+	}
+
+	/* Change state AFTER socket is unhashed to avoid closed
+	 * socket sitting in hash tables.
+	 */
+	sk->sk_state = state;
+
+#ifdef STATE_TRACE
+	SOCK_DEBUG(sk, "TCP sk=%p, State %s -> %s\n",sk, statename[oldstate],statename[state]);
+#endif
+}
+EXPORT_SYMBOL_GPL(tcp_set_state);
+
 /*
  *	State processing on a close. This implements the state shift for
  *	sending our FIN frame. Note that we only send a FIN for some
@@ -1586,7 +1773,7 @@ void tcp_close(struct sock *sk, long timeout)
 		__kfree_skb(skb);
 	}
 
-	sk_stream_mem_reclaim(sk);
+	sk_mem_reclaim(sk);
 
 	/* As outlined in RFC 2525, section 2.17, we send a RST here because
 	 * data was lost. To witness the awful effects of the old behavior of
@@ -1689,7 +1876,7 @@ adjudge_to_death:
 		}
 	}
 	if (sk->sk_state != TCP_CLOSE) {
-		sk_stream_mem_reclaim(sk);
+		sk_mem_reclaim(sk);
 		if (tcp_too_many_orphans(sk,
 				atomic_read(sk->sk_prot->orphan_count))) {
 			if (net_ratelimit())
@@ -2411,7 +2598,6 @@ void tcp_done(struct sock *sk)
 }
 EXPORT_SYMBOL_GPL(tcp_done);
 
-extern void __skb_cb_too_small_for_tcp(int, int);
 extern struct tcp_congestion_ops tcp_reno;
 
 static __initdata unsigned long thash_entries;
@@ -2430,9 +2616,7 @@ void __init tcp_init(void)
 	unsigned long limit;
 	int order, i, max_share;
 
-	if (sizeof(struct tcp_skb_cb) > sizeof(skb->cb))
-		__skb_cb_too_small_for_tcp(sizeof(struct tcp_skb_cb),
-					   sizeof(skb->cb));
+	BUILD_BUG_ON(sizeof(struct tcp_skb_cb) > sizeof(skb->cb));
 
 	tcp_hashinfo.bind_bucket_cachep =
 		kmem_cache_create("tcp_bind_bucket",
@@ -2509,11 +2693,11 @@ void __init tcp_init(void)
 	limit = ((unsigned long)sysctl_tcp_mem[1]) << (PAGE_SHIFT - 7);
 	max_share = min(4UL*1024*1024, limit);
 
-	sysctl_tcp_wmem[0] = SK_STREAM_MEM_QUANTUM;
+	sysctl_tcp_wmem[0] = SK_MEM_QUANTUM;
 	sysctl_tcp_wmem[1] = 16*1024;
 	sysctl_tcp_wmem[2] = max(64*1024, max_share);
 
-	sysctl_tcp_rmem[0] = SK_STREAM_MEM_QUANTUM;
+	sysctl_tcp_rmem[0] = SK_MEM_QUANTUM;
 	sysctl_tcp_rmem[1] = 87380;
 	sysctl_tcp_rmem[2] = max(87380, max_share);
 
@@ -2532,6 +2716,7 @@ EXPORT_SYMBOL(tcp_poll);
 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);