net: Add and use skb_copy_datagram_msg() helper.

This encapsulates all of the skb_copy_datagram_iovec() callers
with call argument signature "skb, offset, msghdr->msg_iov, length".

When we move to iov_iters in the networking, the iov_iter object will
sit in the msghdr.

Having a helper like this means there will be less places to touch
during that transformation.

Based upon descriptions and patch from Al Viro.

Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/isdn/mISDN/socket.c

@@ -163,7 +163,7 @@ mISDN_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
 	memcpy(skb_push(skb, MISDN_HEADER_LEN), mISDN_HEAD_P(skb),
 	       MISDN_HEADER_LEN);
 
-	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
+	err = skb_copy_datagram_msg(skb, 0, msg, copied);
 
 	mISDN_sock_cmsg(sk, msg, skb);
 

drivers/net/ppp/pppoe.c

@@ -981,7 +981,7 @@ static int pppoe_recvmsg(struct kiocb *iocb, struct socket *sock,
 
 	if (skb) {
 		total_len = min_t(size_t, total_len, skb->len);
-		error = skb_copy_datagram_iovec(skb, 0, m->msg_iov, total_len);
+		error = skb_copy_datagram_msg(skb, 0, m, total_len);
 		if (error == 0) {
 			consume_skb(skb);
 			return total_len;

include/linux/skbuff.h

@@ -21,6 +21,7 @@
 #include <linux/bug.h>
 #include <linux/cache.h>
 #include <linux/rbtree.h>
+#include <linux/socket.h>
 
 #include <linux/atomic.h>
 #include <asm/types.h>
@@ -2639,6 +2640,11 @@ unsigned int datagram_poll(struct file *file, struct socket *sock,
 			   struct poll_table_struct *wait);
 int skb_copy_datagram_iovec(const struct sk_buff *from, int offset,
 			    struct iovec *to, int size);
+static inline int skb_copy_datagram_msg(const struct sk_buff *from, int offset,
+					struct msghdr *msg, int size)
+{
+	return skb_copy_datagram_iovec(from, offset, msg->msg_iov, size);
+}
 int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb, int hlen,
 				     struct iovec *iov);
 int skb_copy_datagram_from_iovec(struct sk_buff *skb, int offset,

net/appletalk/ddp.c

@@ -1758,7 +1758,7 @@ static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr
 		copied = size;
 		msg->msg_flags |= MSG_TRUNC;
 	}
-	err = skb_copy_datagram_iovec(skb, offset, msg->msg_iov, copied);
+	err = skb_copy_datagram_msg(skb, offset, msg, copied);
 
 	if (!err && msg->msg_name) {
 		DECLARE_SOCKADDR(struct sockaddr_at *, sat, msg->msg_name);

net/atm/common.c

@@ -554,7 +554,7 @@ int vcc_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
 		msg->msg_flags |= MSG_TRUNC;
 	}
 
-	error = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
+	error = skb_copy_datagram_msg(skb, 0, msg, copied);
 	if (error)
 		return error;
 	sock_recv_ts_and_drops(msg, sk, skb);

net/ax25/af_ax25.c

@@ -1634,7 +1634,7 @@ static int ax25_recvmsg(struct kiocb *iocb, struct socket *sock,
 		msg->msg_flags |= MSG_TRUNC;
 	}
 
-	skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
+	skb_copy_datagram_msg(skb, 0, msg, copied);
 
 	if (msg->msg_name) {
 		ax25_digi digi;

net/bluetooth/af_bluetooth.c

@@ -237,7 +237,7 @@ int bt_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
 	}
 
 	skb_reset_transport_header(skb);
-	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
+	err = skb_copy_datagram_msg(skb, 0, msg, copied);
 	if (err == 0) {
 		sock_recv_ts_and_drops(msg, sk, skb);
 
@@ -328,7 +328,7 @@ int bt_sock_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
 		}
 
 		chunk = min_t(unsigned int, skb->len, size);
-		if (skb_copy_datagram_iovec(skb, 0, msg->msg_iov, chunk)) {
+		if (skb_copy_datagram_msg(skb, 0, msg, chunk)) {
 			skb_queue_head(&sk->sk_receive_queue, skb);
 			if (!copied)
 				copied = -EFAULT;

net/bluetooth/hci_sock.c

@@ -878,7 +878,7 @@ static int hci_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
 	}
 
 	skb_reset_transport_header(skb);
-	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
+	err = skb_copy_datagram_msg(skb, 0, msg, copied);
 
 	switch (hci_pi(sk)->channel) {
 	case HCI_CHANNEL_RAW:

net/caif/caif_socket.c

@@ -293,7 +293,7 @@ static int caif_seqpkt_recvmsg(struct kiocb *iocb, struct socket *sock,
 		copylen = len;
 	}
 
-	ret = skb_copy_datagram_iovec(skb, 0, m->msg_iov, copylen);
+	ret = skb_copy_datagram_msg(skb, 0, m, copylen);
 	if (ret)
 		goto out_free;
 

net/core/sock.c

@@ -2457,7 +2457,7 @@ int sock_recv_errqueue(struct sock *sk, struct msghdr *msg, int len,
 		msg->msg_flags |= MSG_TRUNC;
 		copied = len;
 	}
-	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
+	err = skb_copy_datagram_msg(skb, 0, msg, copied);
 	if (err)
 		goto out_free_skb;
 

net/dccp/proto.c

@@ -896,7 +896,7 @@ verify_sock_status:
 		else if (len < skb->len)
 			msg->msg_flags |= MSG_TRUNC;
 
-		if (skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len)) {
+		if (skb_copy_datagram_msg(skb, 0, msg, len)) {
 			/* Exception. Bailout! */
 			len = -EFAULT;
 			break;

net/ieee802154/dgram.c

@@ -324,7 +324,7 @@ static int dgram_recvmsg(struct kiocb *iocb, struct sock *sk,
 	}
 
 	/* FIXME: skip headers if necessary ?! */
-	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
+	err = skb_copy_datagram_msg(skb, 0, msg, copied);
 	if (err)
 		goto done;
 

net/ieee802154/raw.c

@@ -195,7 +195,7 @@ static int raw_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 		copied = len;
 	}
 
-	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
+	err = skb_copy_datagram_msg(skb, 0, msg, copied);
 	if (err)
 		goto done;
 

net/ipv4/ip_sockglue.c

@@ -424,7 +424,7 @@ int ip_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 		msg->msg_flags |= MSG_TRUNC;
 		copied = len;
 	}
-	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
+	err = skb_copy_datagram_msg(skb, 0, msg, copied);
 	if (err)
 		goto out_free_skb;
 

net/ipv4/ping.c

@@ -875,7 +875,7 @@ int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 	}
 
 	/* Don't bother checking the checksum */
-	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
+	err = skb_copy_datagram_msg(skb, 0, msg, copied);
 	if (err)
 		goto done;
 

net/ipv4/raw.c

@@ -718,7 +718,7 @@ static int raw_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 		copied = len;
 	}
 
-	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
+	err = skb_copy_datagram_msg(skb, 0, msg, copied);
 	if (err)
 		goto done;
 

net/ipv4/tcp.c

@@ -1377,7 +1377,7 @@ static int tcp_peek_sndq(struct sock *sk, struct msghdr *msg, int len)
 	/* XXX -- need to support SO_PEEK_OFF */
 
 	skb_queue_walk(&sk->sk_write_queue, skb) {
-		err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, skb->len);
+		err = skb_copy_datagram_msg(skb, 0, msg, skb->len);
 		if (err)
 			break;
 
@@ -1833,8 +1833,7 @@ do_prequeue:
 		}
 
 		if (!(flags & MSG_TRUNC)) {
-			err = skb_copy_datagram_iovec(skb, offset,
-						      msg->msg_iov, used);
+			err = skb_copy_datagram_msg(skb, offset, msg, used);
 			if (err) {
 				/* Exception. Bailout! */
 				if (!copied)

net/ipv4/udp.c

@@ -1281,8 +1281,8 @@ try_again:
 	}
 
 	if (skb_csum_unnecessary(skb))
-		err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
-					      msg->msg_iov, copied);
+		err = skb_copy_datagram_msg(skb, sizeof(struct udphdr),
+					    msg, copied);
 	else {
 		err = skb_copy_and_csum_datagram_iovec(skb,
 						       sizeof(struct udphdr),

net/ipv6/datagram.c

@@ -351,7 +351,7 @@ int ipv6_recv_error(struct sock *sk, struct msghdr *msg, int len, int *addr_len)
 		msg->msg_flags |= MSG_TRUNC;
 		copied = len;
 	}
-	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
+	err = skb_copy_datagram_msg(skb, 0, msg, copied);
 	if (err)
 		goto out_free_skb;
 
@@ -445,7 +445,7 @@ int ipv6_recv_rxpmtu(struct sock *sk, struct msghdr *msg, int len,
 		msg->msg_flags |= MSG_TRUNC;
 		copied = len;
 	}
-	err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
+	err = skb_copy_datagram_msg(skb, 0, msg, copied);
 	if (err)
 		goto out_free_skb;
 

net/ipv6/raw.c

@@ -486,11 +486,11 @@ static int rawv6_recvmsg(struct kiocb *iocb, struct sock *sk,
 	}
 
 	if (skb_csum_unnecessary(skb)) {
-		err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
+		err = skb_copy_datagram_msg(skb, 0, msg, copied);
 	} else if (msg->msg_flags&MSG_TRUNC) {
 		if (__skb_checksum_complete(skb))
 			goto csum_copy_err;
-		err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
+		err = skb_copy_datagram_msg(skb, 0, msg, copied);
 	} else {
 		err = skb_copy_and_csum_datagram_iovec(skb, 0, msg->msg_iov);
 		if (err == -EINVAL)