Revert "udp: remove redundant variable"

This reverts commit 81d54ec8479a2c695760da81f05b5a9fb2dbe40a.

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: paul bilke <fsmail@conspiracy.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index ab0966d..5a65eea 100644 (file)
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -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;
 

diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 846f475..8c25419 100644 (file)
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -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;