Use correct NET_RX_* returns for atalk_rcv()

In all rx'd SKB cases, atalk_rcv() either eventually jumps to or falls through
    to the label out:, which  returns numeric 0. Numeric 0 corresponds to
    NET_RX_SUCCESS, which is incorrect in failed SKB cases.

    This patch makes atalk_rcv() provide the correct returns by:

    o  explicitly returning NET_RX_SUCCESS in the two success cases
    o  having the out: label return NET_RX_DROP, instead of numeric 0
    o  making the failed SKB labels and processing more consistent with other
       _rcv() routines in the kernel, simplifying validation and removing a
       backwards goto

Signed-off-by: Mark Smith <markzzzsmith@yahoo.com.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 14 insertions, 11 deletions

diff --git a/net/appletalk/ddp.c b/net/appletalk/ddp.c
index 875eda5dbad7..0d42d5da50ad 100644
--- a/net/appletalk/ddp.c
+++ b/net/appletalk/ddp.c
@@ -1400,7 +1400,7 @@ static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
         __u16 len_hops;
 
         if (!net_eq(dev_net(dev), &init_net))
-                goto freeit;
+                goto drop;
 
         /* Don't mangle buffer if shared */
         if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
@@ -1408,7 +1408,7 @@ static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
 
         /* Size check and make sure header is contiguous */
         if (!pskb_may_pull(skb, sizeof(*ddp)))
-                goto freeit;
+                goto drop;
 
         ddp = ddp_hdr(skb);
 
@@ -1426,7 +1426,7 @@ static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
         if (skb->len < sizeof(*ddp) || skb->len < (len_hops & 1023)) {
                 pr_debug("AppleTalk: dropping corrupted frame (deh_len=%u, "
                          "skb->len=%u)\n", len_hops & 1023, skb->len);
-                goto freeit;
+                goto drop;
         }
 
         /*
@@ -1436,7 +1436,7 @@ static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
         if (ddp->deh_sum &&
             atalk_checksum(skb, len_hops & 1023) != ddp->deh_sum)
                 /* Not a valid AppleTalk frame - dustbin time */
-                goto freeit;
+                goto drop;
 
         /* Check the packet is aimed at us */
         if (!ddp->deh_dnet)     /* Net 0 is 'this network' */
@@ -1449,7 +1449,7 @@ static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
                  * AppleTalk iface
                  */
                 atalk_route_packet(skb, dev, ddp, len_hops, origlen);
-                goto out;
+                return NET_RX_SUCCESS;
         }
 
         /* if IP over DDP is not selected this code will be optimized out */
@@ -1465,18 +1465,21 @@ static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
 
         sock = atalk_search_socket(&tosat, atif);
         if (!sock) /* But not one of our sockets */
-                goto freeit;
+                goto drop;
 
         /* Queue packet (standard) */
         skb->sk = sock;
 
         if (sock_queue_rcv_skb(sock, skb) < 0)
-                goto freeit;
-out:
-        return 0;
-freeit:
+                goto drop;
+
+        return NET_RX_SUCCESS;
+
+drop:
         kfree_skb(skb);
-        goto out;
+out:
+        return NET_RX_DROP;
+
 }
 
 /*