linux/net/core
David S. Miller b5cdae3291 net: Generic XDP
This provides a generic SKB based non-optimized XDP path which is used
if either the driver lacks a specific XDP implementation, or the user
requests it via a new IFLA_XDP_FLAGS value named XDP_FLAGS_SKB_MODE.

It is arguable that perhaps I should have required something like
this as part of the initial XDP feature merge.

I believe this is critical for two reasons:

1) Accessibility.  More people can play with XDP with less
   dependencies.  Yes I know we have XDP support in virtio_net, but
   that just creates another depedency for learning how to use this
   facility.

   I wrote this to make life easier for the XDP newbies.

2) As a model for what the expected semantics are.  If there is a pure
   generic core implementation, it serves as a semantic example for
   driver folks adding XDP support.

One thing I have not tried to address here is the issue of
XDP_PACKET_HEADROOM, thanks to Daniel for spotting that.  It seems
incredibly expensive to do a skb_cow(skb, XDP_PACKET_HEADROOM) or
whatever even if the XDP program doesn't try to push headers at all.
I think we really need the verifier to somehow propagate whether
certain XDP helpers are used or not.

v5:
 - Handle both negative and positive offset after running prog
 - Fix mac length in XDP_TX case (Alexei)
 - Use rcu_dereference_protected() in free_netdev (kbuild test robot)

v4:
 - Fix MAC header adjustmnet before calling prog (David Ahern)
 - Disable LRO when generic XDP is installed (Michael Chan)
 - Bypass qdisc et al. on XDP_TX and record the event (Alexei)
 - Do not perform generic XDP on reinjected packets (DaveM)

v3:
 - Make sure XDP program sees packet at MAC header, push back MAC
   header if we do XDP_TX.  (Alexei)
 - Elide GRO when generic XDP is in use.  (Alexei)
 - Add XDP_FLAG_SKB_MODE flag which the user can use to request generic
   XDP even if the driver has an XDP implementation.  (Alexei)
 - Report whether SKB mode is in use in rtnl_xdp_fill() via XDP_FLAGS
   attribute.  (Daniel)

v2:
 - Add some "fall through" comments in switch statements based
   upon feedback from Andrew Lunn
 - Use RCU for generic xdp_prog, thanks to Johannes Berg.

Tested-by: Andy Gospodarek <andy@greyhouse.net>
Tested-by: Jesper Dangaard Brouer <brouer@redhat.com>
Tested-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-25 13:33:49 -04:00
..
datagram.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-04-15 21:16:30 -04:00
dev_addr_lists.c net: fix spelling for synchronized 2014-11-18 15:26:32 -05:00
dev_ioctl.c dev_ioctl: use sizeof(x) instead of sizeof x 2014-11-18 15:27:32 -05:00
dev.c net: Generic XDP 2017-04-25 13:33:49 -04:00
devlink.c net/devlink: Add E-Switch encapsulation control 2017-04-22 20:26:37 +03:00
drop_monitor.c drop_monitor: use setup_timer 2017-03-12 23:47:16 -07:00
dst_cache.c net: dst_cache_per_cpu_dst_set() can be static 2016-03-18 17:45:08 -04:00
dst.c net: pending_confirm is not used anymore 2017-02-07 13:07:47 -05:00
ethtool.c net: Add ESP offload features 2017-04-14 10:05:36 +02:00
fib_rules.c net: rtnetlink: plumb extended ack to doit function 2017-04-17 15:35:38 -04:00
filter.c bpf: add napi_id read access to __sk_buff 2017-04-21 13:53:27 -04:00
flow_dissector.c flow_dissector: add mpls support (v2) 2017-04-24 14:30:46 -04:00
flow.c flowcache: more "unsigned int" 2017-04-03 19:04:48 -07:00
gen_estimator.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
gen_stats.c net_sched: gen_estimator: complete rewrite of rate estimators 2016-12-05 15:21:59 -05:00
gro_cells.c net: Generic XDP 2017-04-25 13:33:49 -04:00
hwbm.c net: hwbm: Fix unbalanced spinlock in error case 2016-05-25 12:35:09 -07:00
link_watch.c dev: introduce dev_get_iflink() 2015-04-02 14:04:59 -04:00
lwt_bpf.c netlink: pass extended ACK struct to parsing functions 2017-04-13 13:58:22 -04:00
lwtunnel.c lwtunnel: check return value of nla_nest_start 2017-04-24 15:51:30 -04:00
Makefile gro_cells: move to net/core/gro_cells.c 2017-02-08 14:38:18 -05:00
neighbour.c net: rtnetlink: plumb extended ack to doit function 2017-04-17 15:35:38 -04:00
net_namespace.c net: rtnetlink: plumb extended ack to doit function 2017-04-17 15:35:38 -04:00
net-procfs.c net: remove NETDEV_TX_LOCKED support 2016-04-26 15:53:05 -04:00
net-sysfs.c net: use net->count to check whether a netns is alive or not 2017-03-13 16:02:27 -07:00
net-sysfs.h net: netdev_kobject_init: annotate with __init 2014-01-05 20:27:54 -05:00
net-traces.c net: IPv6 fib lookup tracepoint 2015-11-22 11:54:10 -05:00
netclassid_cgroup.c cgroup, net_cls: iterate the fds of only the tasks which are being migrated 2017-03-22 10:32:46 -07:00
netevent.c netevent: remove automatic variable in register_netevent_notifier() 2015-05-31 00:03:21 -07:00
netpoll.c netpoll: Check for skb->queue_mapping 2017-04-21 15:45:19 -04:00
netprio_cgroup.c net: break include loop netdevice.h, dsa.h, devlink.h 2017-03-28 22:46:04 -07:00
pktgen.c net-tc: convert tc_verd to integer bitfields 2017-01-08 20:58:52 -05:00
ptp_classifier.c ptp: Change ptp_class to a proper bitmask 2015-11-03 11:08:22 -05:00
request_sock.c ipv4: Namespaceify tcp_max_syn_backlog knob 2016-12-29 11:38:31 -05:00
rtnetlink.c net: Generic XDP 2017-04-25 13:33:49 -04:00
scm.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/user.h> 2017-03-02 08:42:29 +01:00
secure_seq.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-04-06 08:24:51 -07:00
skbuff.c gso: Validate assumption of frag_list segementation 2017-04-21 13:30:29 -04:00
sock_diag.c netlink: extended ACK reporting 2017-04-13 13:58:20 -04:00
sock_reuseport.c soreuseport: use "unsigned int" in __reuseport_alloc() 2017-04-03 19:06:38 -07:00
sock.c New getsockopt option to get socket cookie 2017-04-08 08:07:01 -07:00
stream.c sched/headers: Prepare for new header dependencies before moving code to <linux/sched/signal.h> 2017-03-02 08:42:29 +01:00
sysctl_net_core.c Replace 2 jiffies with sysctl netdev_budget_usecs to enable softirq tuning 2017-04-21 13:22:34 -04:00
timestamping.c net: skb_defer_rx_timestamp should check for phydev before setting up classify 2015-07-09 14:17:15 -07:00
tso.c net: tso: add support for IPv6 2015-10-26 22:24:22 -07:00
utils.c net: make in_aton() 32-bit internally 2017-03-24 13:27:19 -07:00