From 8dfd329fbc240729938d24bf87aca49ea89289c5 Mon Sep 17 00:00:00 2001 From: Zhang Shengju Date: Fri, 4 Mar 2016 14:07:54 +0000 Subject: [PATCH] arp: correct return value of arp_rcv Currently, arp_rcv() always return zero on a packet delivery upcall. To make its behavior more compliant with the way this API should be used, this patch changes this to let it return NET_RX_SUCCESS when the packet is proper handled, and NET_RX_DROP otherwise. v1->v2: If sanity check is failed, call kfree_skb() instead of consume_skb(), then return the correct return value. Signed-off-by: Zhang Shengju Signed-off-by: David S. Miller --- net/ipv4/arp.c | 35 ++++++++++++++++++++--------------- 1 file changed, 20 insertions(+), 15 deletions(-) diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c index c102eb5ac55c..c34c7544d1db 100644 --- a/net/ipv4/arp.c +++ b/net/ipv4/arp.c @@ -665,7 +665,7 @@ static int arp_process(struct net *net, struct sock *sk, struct sk_buff *skb) */ if (!in_dev) - goto out; + goto out_free_skb; arp = arp_hdr(skb); @@ -673,7 +673,7 @@ static int arp_process(struct net *net, struct sock *sk, struct sk_buff *skb) default: if (arp->ar_pro != htons(ETH_P_IP) || htons(dev_type) != arp->ar_hrd) - goto out; + goto out_free_skb; break; case ARPHRD_ETHER: case ARPHRD_FDDI: @@ -690,17 +690,17 @@ static int arp_process(struct net *net, struct sock *sk, struct sk_buff *skb) if ((arp->ar_hrd != htons(ARPHRD_ETHER) && arp->ar_hrd != htons(ARPHRD_IEEE802)) || arp->ar_pro != htons(ETH_P_IP)) - goto out; + goto out_free_skb; break; case ARPHRD_AX25: if (arp->ar_pro != htons(AX25_P_IP) || arp->ar_hrd != htons(ARPHRD_AX25)) - goto out; + goto out_free_skb; break; case ARPHRD_NETROM: if (arp->ar_pro != htons(AX25_P_IP) || arp->ar_hrd != htons(ARPHRD_NETROM)) - goto out; + goto out_free_skb; break; } @@ -708,7 +708,7 @@ static int arp_process(struct net *net, struct sock *sk, struct sk_buff *skb) if (arp->ar_op != htons(ARPOP_REPLY) && arp->ar_op != htons(ARPOP_REQUEST)) - goto out; + goto out_free_skb; /* * Extract fields @@ -733,7 +733,7 @@ static int arp_process(struct net *net, struct sock *sk, struct sk_buff *skb) */ if (ipv4_is_multicast(tip) || (!IN_DEV_ROUTE_LOCALNET(in_dev) && ipv4_is_loopback(tip))) - goto out; + goto out_free_skb; /* * For some 802.11 wireless deployments (and possibly other networks), @@ -741,7 +741,7 @@ static int arp_process(struct net *net, struct sock *sk, struct sk_buff *skb) * and thus should not be accepted. */ if (sip == tip && IN_DEV_ORCONF(in_dev, DROP_GRATUITOUS_ARP)) - goto out; + goto out_free_skb; /* * Special case: We must set Frame Relay source Q.922 address @@ -778,7 +778,7 @@ static int arp_process(struct net *net, struct sock *sk, struct sk_buff *skb) !arp_ignore(in_dev, sip, tip)) arp_send_dst(ARPOP_REPLY, ETH_P_ARP, sip, dev, tip, sha, dev->dev_addr, sha, reply_dst); - goto out; + goto out_consume_skb; } if (arp->ar_op == htons(ARPOP_REQUEST) && @@ -803,7 +803,7 @@ static int arp_process(struct net *net, struct sock *sk, struct sk_buff *skb) neigh_release(n); } } - goto out; + goto out_consume_skb; } else if (IN_DEV_FORWARD(in_dev)) { if (addr_type == RTN_UNICAST && (arp_fwd_proxy(in_dev, dev, rt) || @@ -826,7 +826,7 @@ static int arp_process(struct net *net, struct sock *sk, struct sk_buff *skb) in_dev->arp_parms, skb); goto out_free_dst; } - goto out; + goto out_consume_skb; } } } @@ -876,11 +876,16 @@ static int arp_process(struct net *net, struct sock *sk, struct sk_buff *skb) neigh_release(n); } -out: +out_consume_skb: consume_skb(skb); + out_free_dst: dst_release(reply_dst); - return 0; + return NET_RX_SUCCESS; + +out_free_skb: + kfree_skb(skb); + return NET_RX_DROP; } static void parp_redo(struct sk_buff *skb) @@ -924,11 +929,11 @@ static int arp_rcv(struct sk_buff *skb, struct net_device *dev, consumeskb: consume_skb(skb); - return 0; + return NET_RX_SUCCESS; freeskb: kfree_skb(skb); out_of_mem: - return 0; + return NET_RX_DROP; } /* -- GitLab