Messages in this thread | | | Date | Wed, 7 Jul 2021 09:42:18 -0700 | From | Jakub Kicinski <> | Subject | Re: [PATCH IPV6 1/1] ipv6: allocate enough headroom in ip6_finish_output2() |
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On Wed, 7 Jul 2021 08:45:13 -0600 David Ahern wrote: > On 7/7/21 8:04 AM, Vasily Averin wrote: > > diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c > > index ff4f9eb..e5af740 100644 > > --- a/net/ipv6/ip6_output.c > > +++ b/net/ipv6/ip6_output.c > > @@ -61,9 +61,24 @@ static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff * > > struct dst_entry *dst = skb_dst(skb); > > struct net_device *dev = dst->dev; > > const struct in6_addr *nexthop; > > + unsigned int hh_len = LL_RESERVED_SPACE(dev); > > struct neighbour *neigh; > > int ret; > > > > + /* Be paranoid, rather than too clever. */ > > + if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) { > > + struct sk_buff *skb2; > > + > > + skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev)); > > why not use hh_len here?
Is there a reason for the new skb? Why not pskb_expand_head()?
> > + if (!skb2) { > > + kfree_skb(skb); > > + return -ENOMEM; > > + } > > + if (skb->sk) > > + skb_set_owner_w(skb2, skb->sk); > > + consume_skb(skb); > > + skb = skb2; > > + } > > if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) { > > struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
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