netdev - Re: [bpf-next v2 8/9] bpf: Provide helper to do forwarding lookups in kernel FIB table

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <433c2320-ed9b-446e-6e29-92075f947251@iogearbox.net>
Date:   Wed, 9 May 2018 10:15:05 +0200
From:   Daniel Borkmann <daniel@...earbox.net>
To:     David Ahern <dsahern@...il.com>, netdev@...r.kernel.org,
        borkmann@...earbox.net, ast@...nel.org
Cc:     davem@...emloft.net, shm@...ulusnetworks.com,
        roopa@...ulusnetworks.com, brouer@...hat.com, toke@...e.dk,
        john.fastabend@...il.com
Subject: Re: [bpf-next v2 8/9] bpf: Provide helper to do forwarding lookups in
 kernel FIB table

On 05/04/2018 04:54 AM, David Ahern wrote:
> Provide a helper for doing a FIB and neighbor lookup in the kernel
> tables from an XDP program. The helper provides a fastpath for forwarding
> packets. If the packet is a local delivery or for any reason is not a
> simple lookup and forward, the packet continues up the stack.
> 
> If it is to be forwarded, the forwarding can be done directly if the
> neighbor is already known. If the neighbor does not exist, the first
> few packets go up the stack for neighbor resolution. Once resolved, the
> xdp program provides the fast path.
> 
> On successful lookup the nexthop dmac, current device smac and egress
> device index are returned.
> 
> The API supports IPv4, IPv6 and MPLS protocols, but only IPv4 and IPv6
> are implemented in this patch. The API includes layer 4 parameters if
> the XDP program chooses to do deep packet inspection to allow compare
> against ACLs implemented as FIB rules.
> 
> Header rewrite is left to the XDP program.
> 
> The lookup takes 2 flags:
> - BPF_FIB_LOOKUP_DIRECT to do a lookup that bypasses FIB rules and goes
>   straight to the table associated with the device (expert setting for
>   those looking to maximize throughput)
> 
> - BPF_FIB_LOOKUP_OUTPUT to do a lookup from the egress perspective.
>   Default is an ingress lookup.
> 
> Initial performance numbers collected by Jesper, forwarded packets/sec:
> 
>        Full stack    XDP FIB lookup    XDP Direct lookup
> IPv4   1,947,969       7,074,156          7,415,333
> IPv6   1,728,000       6,165,504          7,262,720
> 
> These number are single CPU core forwarding on a Broadwell
> E5-1650 v4 @ 3.60GHz.
> 
> Signed-off-by: David Ahern <dsahern@...il.com>

Ohh well, this is causing allmodconfig build warnings (e.g. on x86) as reported today:

In file included from include/linux/dma-mapping.h:5:0,
                 from include/linux/skbuff.h:34,
                 from include/linux/if_ether.h:23,
                 from include/uapi/linux/bpf.h:13,
                 from include/linux/bpf-cgroup.h:6,
                 from include/linux/cgroup-defs.h:22,
                 from include/linux/cgroup.h:28,
                 from include/linux/perf_event.h:57,
                 from include/linux/trace_events.h:10,
                 from include/trace/trace_events.h:20,
                 from include/trace/define_trace.h:96,
                 from drivers/android/binder_trace.h:387,
                 from drivers/android/binder.c:5702:
include/linux/sizes.h:24:0: warning: "SZ_1K" redefined
 #define SZ_1K    0x00000400
drivers/android/binder.c:116:0: note: this is the location of the previous definition
 #define SZ_1K                               0x400
In file included from include/linux/dma-mapping.h:5:0,
                 from include/linux/skbuff.h:34,
                 from include/linux/if_ether.h:23,
                 from include/uapi/linux/bpf.h:13,
                 from include/linux/bpf-cgroup.h:6,
                 from include/linux/cgroup-defs.h:22,
                 from include/linux/cgroup.h:28,
                 from include/linux/perf_event.h:57,
                 from include/linux/trace_events.h:10,
                 from include/trace/trace_events.h:20,
                 from include/trace/define_trace.h:96,
                 from drivers/android/binder_trace.h:387,
                 from drivers/android/binder.c:5702:
include/linux/sizes.h:37:0: warning: "SZ_4M" redefined
 #define SZ_4M    0x00400000
drivers/android/binder.c:120:0: note: this is the location of the previous definition
 #define SZ_4M                               0x400000
fs/ecryptfs/miscdev.c:206:0: warning: "PKT_TYPE_OFFSET" redefined
 #define PKT_TYPE_OFFSET  0
In file included from include/linux/if_ether.h:23:0,
                 from include/uapi/linux/bpf.h:13,
                 from include/linux/bpf-cgroup.h:6,
                 from include/linux/cgroup-defs.h:22,
                 from include/linux/cgroup.h:28,
                 from include/linux/writeback.h:183,
                 from include/linux/backing-dev.h:16,
                 from fs/ecryptfs/ecryptfs_kernel.h:41,
                 from fs/ecryptfs/miscdev.c:30:
include/linux/skbuff.h:753:0: note: this is the location of the previous definition
 #define PKT_TYPE_OFFSET() offsetof(struct sk_buff, __pkt_type_offset)

Lets get a clean, proper version of the whole series into bpf-next. I've dropped it
from there right now and waiting for your v3 respin to apply with the above fixed.

Thank you.