Merge branch 'bpf-next'
Daniel Borkmann says:
====================
BPF update
Fixes a csum issue on ingress. As mentioned previously, net-next
seems just fine imho. Later on, will follow up with couple of
replacements like ovs_skb_postpush_rcsum() etc.
Thanks!
v1 -> v2:
- Added patch 1 with helper
- Implemented Hannes' idea to just use csum_partial, thanks!
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 6b6bd42..07f9ccd 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -2805,6 +2805,23 @@
unsigned char *skb_pull_rcsum(struct sk_buff *skb, unsigned int len);
+static inline void skb_postpush_rcsum(struct sk_buff *skb,
+ const void *start, unsigned int len)
+{
+ /* For performing the reverse operation to skb_postpull_rcsum(),
+ * we can instead of ...
+ *
+ * skb->csum = csum_add(skb->csum, csum_partial(start, len, 0));
+ *
+ * ... just use this equivalent version here to save a few
+ * instructions. Feeding csum of 0 in csum_partial() and later
+ * on adding skb->csum is equivalent to feed skb->csum in the
+ * first place.
+ */
+ if (skb->ip_summed == CHECKSUM_COMPLETE)
+ skb->csum = csum_partial(start, len, skb->csum);
+}
+
/**
* pskb_trim_rcsum - trim received skb and update checksum
* @skb: buffer to trim
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h
index b2a8e63..636a362 100644
--- a/include/net/sch_generic.h
+++ b/include/net/sch_generic.h
@@ -407,6 +407,15 @@
void tcf_destroy_chain(struct tcf_proto __rcu **fl);
int skb_do_redirect(struct sk_buff *);
+static inline bool skb_at_tc_ingress(const struct sk_buff *skb)
+{
+#ifdef CONFIG_NET_CLS_ACT
+ return G_TC_AT(skb->tc_verd) & AT_INGRESS;
+#else
+ return false;
+#endif
+}
+
/* Reset all TX qdiscs greater then index of a device. */
static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i)
{
diff --git a/net/core/filter.c b/net/core/filter.c
index 35e6fed..0db92b5 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -1368,8 +1368,9 @@
/* skb_store_bits cannot return -EFAULT here */
skb_store_bits(skb, offset, ptr, len);
- if (BPF_RECOMPUTE_CSUM(flags) && skb->ip_summed == CHECKSUM_COMPLETE)
- skb->csum = csum_add(skb->csum, csum_partial(ptr, len, 0));
+ if (BPF_RECOMPUTE_CSUM(flags))
+ skb_postpush_rcsum(skb, ptr, len);
+
return 0;
}
@@ -1525,8 +1526,12 @@
if (unlikely(!skb2))
return -ENOMEM;
- if (BPF_IS_REDIRECT_INGRESS(flags))
+ if (BPF_IS_REDIRECT_INGRESS(flags)) {
+ if (skb_at_tc_ingress(skb2))
+ skb_postpush_rcsum(skb2, skb_mac_header(skb2),
+ skb2->mac_len);
return dev_forward_skb(dev, skb2);
+ }
skb2->dev = dev;
skb_sender_cpu_clear(skb2);
@@ -1569,8 +1574,12 @@
return -EINVAL;
}
- if (BPF_IS_REDIRECT_INGRESS(ri->flags))
+ if (BPF_IS_REDIRECT_INGRESS(ri->flags)) {
+ if (skb_at_tc_ingress(skb))
+ skb_postpush_rcsum(skb, skb_mac_header(skb),
+ skb->mac_len);
return dev_forward_skb(dev, skb);
+ }
skb->dev = dev;
skb_sender_cpu_clear(skb);
diff --git a/net/sched/cls_bpf.c b/net/sched/cls_bpf.c
index 5faaa54..b3c8bb4 100644
--- a/net/sched/cls_bpf.c
+++ b/net/sched/cls_bpf.c
@@ -79,12 +79,8 @@
struct tcf_result *res)
{
struct cls_bpf_head *head = rcu_dereference_bh(tp->root);
+ bool at_ingress = skb_at_tc_ingress(skb);
struct cls_bpf_prog *prog;
-#ifdef CONFIG_NET_CLS_ACT
- bool at_ingress = G_TC_AT(skb->tc_verd) & AT_INGRESS;
-#else
- bool at_ingress = false;
-#endif
int ret = -1;
if (unlikely(!skb_mac_header_was_set(skb)))