Commit 59c2cdae authored by David S. Miller's avatar David S. Miller
Browse files

Revert "udp: remove redundant variable" 



This reverts commit 81d54ec8.

If we take the "try_again" goto, due to a checksum error,
the 'len' has already been truncated.  So we won't compute
the same values as the original code did.

Reported-by: default avatarpaul bilke <fsmail@conspiracy.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent b03b6dd5

net/ipv4/udp.c

+8 −7
Original line number Diff line number Diff line
@@ -1164,7 +1164,7 @@ int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg, 
	struct inet_sock *inet = inet_sk(sk);

	struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;

	struct sk_buff *skb;

	unsigned int ulen;

	unsigned int ulen, copied;

	int peeked;

	int err;

	int is_udplite = IS_UDPLITE(sk);
@@ -1186,9 +1186,10 @@ try_again: 
		goto out;



	ulen = skb->len - sizeof(struct udphdr);

	if (len > ulen)

		len = ulen;

	else if (len < ulen)

	copied = len;

	if (copied > ulen)

		copied = ulen;

	else if (copied < ulen)

		msg->msg_flags |= MSG_TRUNC;



	/*
@@ -1197,14 +1198,14 @@ try_again: 
	 * coverage checksum (UDP-Lite), do it before the copy.

	 */



	if (len < ulen || UDP_SKB_CB(skb)->partial_cov) {

	if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {

		if (udp_lib_checksum_complete(skb))

			goto csum_copy_err;

	}



	if (skb_csum_unnecessary(skb))

		err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),

					      msg->msg_iov, len);

					      msg->msg_iov, copied);

	else {

		err = skb_copy_and_csum_datagram_iovec(skb,

						       sizeof(struct udphdr),
@@ -1233,7 +1234,7 @@ try_again: 
	if (inet->cmsg_flags)

		ip_cmsg_recv(msg, skb);



	err = len;

	err = copied;

	if (flags & MSG_TRUNC)

		err = ulen;

net/ipv6/udp.c

+8 −7
Original line number Diff line number Diff line
@@ -340,7 +340,7 @@ int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk, 
	struct ipv6_pinfo *np = inet6_sk(sk);

	struct inet_sock *inet = inet_sk(sk);

	struct sk_buff *skb;

	unsigned int ulen;

	unsigned int ulen, copied;

	int peeked;

	int err;

	int is_udplite = IS_UDPLITE(sk);
@@ -363,9 +363,10 @@ try_again: 
		goto out;



	ulen = skb->len - sizeof(struct udphdr);

	if (len > ulen)

		len = ulen;

	else if (len < ulen)

	copied = len;

	if (copied > ulen)

		copied = ulen;

	else if (copied < ulen)

		msg->msg_flags |= MSG_TRUNC;



	is_udp4 = (skb->protocol == htons(ETH_P_IP));
@@ -376,14 +377,14 @@ try_again: 
	 * coverage checksum (UDP-Lite), do it before the copy.

	 */



	if (len < ulen || UDP_SKB_CB(skb)->partial_cov) {

	if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {

		if (udp_lib_checksum_complete(skb))

			goto csum_copy_err;

	}



	if (skb_csum_unnecessary(skb))

		err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),

					      msg->msg_iov,len);

					      msg->msg_iov, copied       );

	else {

		err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);

		if (err == -EINVAL)
@@ -432,7 +433,7 @@ try_again: 
			datagram_recv_ctl(sk, msg, skb);

	}



	err = len;

	err = copied;

	if (flags & MSG_TRUNC)

		err = ulen;

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