sk_buff: remove support for csum_bad in sk_buff

This bit was introduced with commit 5a21232983aa ("net: Support for
csum_bad in skbuff") to reduce the stack workload when processing RX
packets carrying a wrong Internet Checksum. Up to now, only one driver and
GRO core are setting it.

Suggested-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/aquantia/atlantic/aq_ring.c b/drivers/net/ethernet/aquantia/atlantic/aq_ring.c
index 3a8a4aa..9a08179 100644 (file)
--- a/drivers/net/ethernet/aquantia/atlantic/aq_ring.c
+++ b/drivers/net/ethernet/aquantia/atlantic/aq_ring.c
@@ -223,7 +223,7 @@ int aq_ring_rx_clean(struct aq_ring_s *self, int *work_done, int budget)
                skb->protocol = eth_type_trans(skb, ndev);
                if (unlikely(buff->is_cso_err)) {
                        ++self->stats.rx.errors;
-                       __skb_mark_checksum_bad(skb);
+                       skb->ip_summed = CHECKSUM_NONE;
                } else {
                        if (buff->is_ip_cso) {
                                __skb_incr_checksum_unnecessary(skb);

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index abbc72e..c1611ac 100644 (file)
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2573,9 +2573,7 @@ static inline void skb_gro_incr_csum_unnecessary(struct sk_buff *skb)
        if (__skb_gro_checksum_validate_needed(skb, zero_okay, check))  \
                __ret = __skb_gro_checksum_validate_complete(skb,       \
                                compute_pseudo(skb, proto));            \
-       if (__ret)                                                      \
-               __skb_mark_checksum_bad(skb);                           \
-       else                                                            \
+       if (!__ret)                                                     \
                skb_gro_incr_csum_unnecessary(skb);                     \
        __ret;                                                          \
 })

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 62d6296..c38f890 100644 (file)
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -685,7 +685,7 @@ struct sk_buff {
        __u8                    csum_valid:1;
        __u8                    csum_complete_sw:1;
        __u8                    csum_level:2;
-       __u8                    csum_bad:1;
+       __u8                    __csum_bad_unused:1; /* one bit hole */
 
        __u8                    dst_pending_confirm:1;
 #ifdef CONFIG_IPV6_NDISC_NODETYPE
@@ -3336,21 +3336,6 @@ static inline void __skb_incr_checksum_unnecessary(struct sk_buff *skb)
        }
 }
 
-static inline void __skb_mark_checksum_bad(struct sk_buff *skb)
-{
-       /* Mark current checksum as bad (typically called from GRO
-        * path). In the case that ip_summed is CHECKSUM_NONE
-        * this must be the first checksum encountered in the packet.
-        * When ip_summed is CHECKSUM_UNNECESSARY, this is the first
-        * checksum after the last one validated. For UDP, a zero
-        * checksum can not be marked as bad.
-        */
-
-       if (skb->ip_summed == CHECKSUM_NONE ||
-           skb->ip_summed == CHECKSUM_UNNECESSARY)
-               skb->csum_bad = 1;
-}
-
 /* Check if we need to perform checksum complete validation.
  *
  * Returns true if checksum complete is needed, false otherwise
@@ -3404,9 +3389,6 @@ static inline __sum16 __skb_checksum_validate_complete(struct sk_buff *skb,
                        skb->csum_valid = 1;
                        return 0;
                }
-       } else if (skb->csum_bad) {
-               /* ip_summed == CHECKSUM_NONE in this case */
-               return (__force __sum16)1;
        }
 
        skb->csum = psum;
@@ -3466,8 +3448,7 @@ static inline __wsum null_compute_pseudo(struct sk_buff *skb, int proto)
 
 static inline bool __skb_checksum_convert_check(struct sk_buff *skb)
 {
-       return (skb->ip_summed == CHECKSUM_NONE &&
-               skb->csum_valid && !skb->csum_bad);
+       return (skb->ip_summed == CHECKSUM_NONE && skb->csum_valid);
 }
 
 static inline void __skb_checksum_convert(struct sk_buff *skb,

diff --git a/net/bridge/netfilter/nft_reject_bridge.c b/net/bridge/netfilter/nft_reject_bridge.c
index 346ef6b..c16dd3a 100644 (file)
--- a/net/bridge/netfilter/nft_reject_bridge.c
+++ b/net/bridge/netfilter/nft_reject_bridge.c
@@ -111,7 +111,7 @@ static void nft_reject_br_send_v4_unreach(struct net *net,
        __wsum csum;
        u8 proto;
 
-       if (oldskb->csum_bad || !nft_bridge_iphdr_validate(oldskb))
+       if (!nft_bridge_iphdr_validate(oldskb))
                return;
 
        /* IP header checks: fragment. */
@@ -226,9 +226,6 @@ static bool reject6_br_csum_ok(struct sk_buff *skb, int hook)
        __be16 fo;
        u8 proto = ip6h->nexthdr;
 
-       if (skb->csum_bad)
-               return false;
-
        if (skb_csum_unnecessary(skb))
                return true;
 

diff --git a/net/core/dev.c b/net/core/dev.c
index 8356d5f..f0281ff 100644 (file)
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4678,9 +4678,6 @@ static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff
        if (netif_elide_gro(skb->dev))
                goto normal;
 
-       if (skb->csum_bad)
-               goto normal;
-
        gro_list_prepare(napi, skb);
 
        rcu_read_lock();

diff --git a/net/ipv4/netfilter/nf_reject_ipv4.c b/net/ipv4/netfilter/nf_reject_ipv4.c
index 7cd8d0d..6f8d9e5 100644 (file)
--- a/net/ipv4/netfilter/nf_reject_ipv4.c
+++ b/net/ipv4/netfilter/nf_reject_ipv4.c
@@ -172,7 +172,7 @@ void nf_send_unreach(struct sk_buff *skb_in, int code, int hook)
        struct iphdr *iph = ip_hdr(skb_in);
        u8 proto;
 
-       if (skb_in->csum_bad || iph->frag_off & htons(IP_OFFSET))
+       if (iph->frag_off & htons(IP_OFFSET))
                return;
 
        if (skb_csum_unnecessary(skb_in)) {

diff --git a/net/ipv6/netfilter/nf_reject_ipv6.c b/net/ipv6/netfilter/nf_reject_ipv6.c
index eedee5d..f63b18e 100644 (file)
--- a/net/ipv6/netfilter/nf_reject_ipv6.c
+++ b/net/ipv6/netfilter/nf_reject_ipv6.c
@@ -220,9 +220,6 @@ static bool reject6_csum_ok(struct sk_buff *skb, int hook)
        __be16 fo;
        u8 proto;
 
-       if (skb->csum_bad)
-               return false;
-
        if (skb_csum_unnecessary(skb))
                return true;