[NETFILTER]: Fix HW checksum handling in ip_queue/ip6_queue

The checksum needs to be filled in on output, after mangling a packet
ip_summed needs to be reset.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 14 insertions, 0 deletions

diff --git a/net/ipv4/netfilter/ip_queue.c b/net/ipv4/netfilter/ip_queue.c
index eda1fba431a4..c6baa8174389 100644
--- a/net/ipv4/netfilter/ip_queue.c
+++ b/net/ipv4/netfilter/ip_queue.c
@@ -214,6 +214,12 @@ ipq_build_packet_message(struct ipq_queue_entry *entry, int *errp)
                 break;
         
         case IPQ_COPY_PACKET:
+                if (entry->skb->ip_summed == CHECKSUM_HW &&
+                    (*errp = skb_checksum_help(entry->skb,
+                                               entry->info->outdev == NULL))) {
+                        read_unlock_bh(&queue_lock);
+                        return NULL;
+                }
                 if (copy_range == 0 || copy_range > entry->skb->len)
                         data_len = entry->skb->len;
                 else
@@ -385,6 +391,7 @@ ipq_mangle_ipv4(ipq_verdict_msg_t *v, struct ipq_queue_entry *e)
         if (!skb_ip_make_writable(&e->skb, v->data_len))
                 return -ENOMEM;
         memcpy(e->skb->data, v->payload, v->data_len);
+        e->skb->ip_summed = CHECKSUM_NONE;
         e->skb->nfcache |= NFC_ALTERED;
 
         /*
diff --git a/net/ipv6/netfilter/ip6_queue.c b/net/ipv6/netfilter/ip6_queue.c
index 5493180f0d44..a16df5b27c84 100644
--- a/net/ipv6/netfilter/ip6_queue.c
+++ b/net/ipv6/netfilter/ip6_queue.c
@@ -211,6 +211,12 @@ ipq_build_packet_message(struct ipq_queue_entry *entry, int *errp)
                 break;
         
         case IPQ_COPY_PACKET:
+                if (entry->skb->ip_summed == CHECKSUM_HW &&
+                    (*errp = skb_checksum_help(entry->skb,
+                                               entry->info->outdev == NULL))) {
+                        read_unlock_bh(&queue_lock);
+                        return NULL;
+                }
                 if (copy_range == 0 || copy_range > entry->skb->len)
                         data_len = entry->skb->len;
                 else
@@ -381,6 +387,7 @@ ipq_mangle_ipv6(ipq_verdict_msg_t *v, struct ipq_queue_entry *e)
         if (!skb_ip_make_writable(&e->skb, v->data_len))
                 return -ENOMEM;
         memcpy(e->skb->data, v->payload, v->data_len);
+        e->skb->ip_summed = CHECKSUM_NONE;
         e->skb->nfcache |= NFC_ALTERED;
 
         /*