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 <dsah...@gmail.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.
