Re: ingress hook on interface with multiple addresses ?

[Pablo Neira Ayuso <pablo@netfilter.org>]

On Thu, Aug 13, 2020 at 12:03:05AM +0200, Florian Westphal wrote:
> sean darcy <seandarcy2@gmail.com> wrote:
> > On 8/12/20 4:57 PM, Florian Westphal wrote:
> > > sean darcy <seandarcy2@gmail.com> wrote:
> > > > I have an interface with 2 ip addresses:
> > > > 
> > > > ip a
> > > > 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group
> > > > default qlen 1000
> > > > ............
> > > > 2: enp1s0f1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state
> > > > UP group default qlen 1000
> > > >      link/ether 98:29:a6:48:49:8e brd ff:ff:ff:ff:ff:ff
> > > >      inet 10.0.0.61/24 brd 10.0.0.255 scope global noprefixroute enp1s0f1
> > > >         valid_lft forever preferred_lft forever
> > > >      inet 10.0.0.2/32 scope global noprefixroute enp1s0f1
> > > >         valid_lft forever preferred_lft forever
> > > > 
> > > > When I try to add a chain on ingress hook, nft is unhappy:
> > > > 
> > > > nft list table netdev foo
> > > > table netdev foo {
> > > > 	set allowlist {
> > > > 		type ipv4_addr
> > > > 		flags interval
> > > > 		auto-merge
> > > > 		elements = { 10.0.0.0/8, 127.0.0.1 }
> > > > 	}
> > > > }
> > > > 
> > > > 
> > > > nft 'add chain netdev foo dev0filter { type filter hook ingress device
> > > > enp1s0f1 priority 0 ; }'
> > > > Error: Could not process rule: No such file or directory
> > > > add chain netdev foo dev0filter { type filter hook ingress device enp1s0f1
> > > > priority 0 ; }
> > > 
> > > works fine for me on 5.7.11 kernel (with adjusted interface name).
> > > 
> > > > Can you have a chain on ingress hook for an interface that has multiple
> > > > addresses ?
> > > 
> > > Its not relevant how many addresses are assigned.
> > > 
> > I'm on Fedora 32:
> > 
> > 5.7.14-200.fc32.
> > rpm -q nftables libnftnl
> > nftables-0.9.3-3.fc32.x86_64
> > libnftnl-1.1.5-2.fc32.x86_64
> 
> Exact same versions here:
> libnftnl-1.1.5-2.fc32.x86_64
> nftables-0.9.3-3.fc32.x86_64
> 
> I will do a kernel update and see if that breaks it.
> I get the same error message if I mistype the device name, but it looks
> like thats not it as per your "ip a" output.

Probably this patch is missing in nftables-0.9.3-3.fc32.x86_64 ?

commit 78bbe7f7a55be48909067e25900de27623d8fa6a
Author: Pablo Neira Ayuso <pablo@netfilter.org>
Date:   Wed Feb 19 21:05:26 2020 +0100

    mnl: do not use expr->identifier to fetch device name
    
    This string might not be nul-terminated, resulting in spurious errors
    when adding netdev chains.