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authorDavid S. Miller <davem@davemloft.net>2021-03-25 15:31:22 -0700
committerDavid S. Miller <davem@davemloft.net>2021-03-25 15:31:22 -0700
commitefd13b71a3fa31413f8d15342e01d44b60b0a432 (patch)
tree2ed1b299e25538c5a60485a1047507b49d3e0ecf /net/core/filter.c
parent84c7f6c33f42a12eb036ebf0f0e3670799304120 (diff)
parent002322402dafd846c424ffa9240a937f49b48c42 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/filter.c')
-rw-r--r--net/core/filter.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/net/core/filter.c b/net/core/filter.c
index b6732000d8a2..f5eeebf6a16f 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -5600,7 +5600,7 @@ BPF_CALL_5(bpf_skb_check_mtu, struct sk_buff *, skb,
if (unlikely(flags & ~(BPF_MTU_CHK_SEGS)))
return -EINVAL;
- if (unlikely(flags & BPF_MTU_CHK_SEGS && len_diff))
+ if (unlikely(flags & BPF_MTU_CHK_SEGS && (len_diff || *mtu_len)))
return -EINVAL;
dev = __dev_via_ifindex(dev, ifindex);
@@ -5610,7 +5610,11 @@ BPF_CALL_5(bpf_skb_check_mtu, struct sk_buff *, skb,
mtu = READ_ONCE(dev->mtu);
dev_len = mtu + dev->hard_header_len;
- skb_len = skb->len + len_diff; /* minus result pass check */
+
+ /* If set use *mtu_len as input, L3 as iph->tot_len (like fib_lookup) */
+ skb_len = *mtu_len ? *mtu_len + dev->hard_header_len : skb->len;
+
+ skb_len += len_diff; /* minus result pass check */
if (skb_len <= dev_len) {
ret = BPF_MTU_CHK_RET_SUCCESS;
goto out;
@@ -5655,6 +5659,10 @@ BPF_CALL_5(bpf_xdp_check_mtu, struct xdp_buff *, xdp,
/* Add L2-header as dev MTU is L3 size */
dev_len = mtu + dev->hard_header_len;
+ /* Use *mtu_len as input, L3 as iph->tot_len (like fib_lookup) */
+ if (*mtu_len)
+ xdp_len = *mtu_len + dev->hard_header_len;
+
xdp_len += len_diff; /* minus result pass check */
if (xdp_len > dev_len)
ret = BPF_MTU_CHK_RET_FRAG_NEEDED;