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Name	Size	Permission	Date
9p	[ DIR ]	drwxr-xr-x	2026-06-04 06:36
bluetooth	[ DIR ]	drwxr-xr-x	2026-06-04 06:36
caif	[ DIR ]	drwxr-xr-x	2026-06-04 06:36
iucv	[ DIR ]	drwxr-xr-x	2026-06-04 06:36
mana	[ DIR ]	drwxr-xr-x	2026-06-04 06:36
netfilter	[ DIR ]	drwxr-xr-x	2026-06-04 06:36
netns	[ DIR ]	drwxr-xr-x	2026-06-04 06:36
nfc	[ DIR ]	drwxr-xr-x	2026-06-04 06:36
page_pool	[ DIR ]	drwxr-xr-x	2026-06-04 06:36
phonet	[ DIR ]	drwxr-xr-x	2026-06-04 06:36
sctp	[ DIR ]	drwxr-xr-x	2026-06-04 06:36
tc_act	[ DIR ]	drwxr-xr-x	2026-06-04 06:36
6lowpan.h	10.03 KB	-rw-r--r--	2024-03-10 20:38
Space.h	455 B	-rw-r--r--	2024-03-10 20:38
act_api.h	9.27 KB	-rw-r--r--	2024-03-10 20:38
addrconf.h	14.28 KB	-rw-r--r--	2026-05-26 09:55
af_ieee802154.h	1.19 KB	-rw-r--r--	2024-03-10 20:38
af_rxrpc.h	3.3 KB	-rw-r--r--	2024-03-10 20:38
af_unix.h	3.76 KB	-rw-r--r--	2026-05-26 09:55
af_vsock.h	8.41 KB	-rw-r--r--	2026-05-26 09:55
ah.h	382 B	-rw-r--r--	2024-03-10 20:38
amt.h	8.35 KB	-rw-r--r--	2024-03-10 20:38
arp.h	1.95 KB	-rw-r--r--	2024-03-10 20:38
atmclip.h	1.48 KB	-rw-r--r--	2024-03-10 20:38
ax25.h	14.94 KB	-rw-r--r--	2026-05-26 09:55
ax88796.h	1.43 KB	-rw-r--r--	2024-03-10 20:38
bareudp.h	333 B	-rw-r--r--	2024-03-10 20:38
bond_3ad.h	9.48 KB	-rw-r--r--	2026-05-26 09:55
bond_alb.h	6.1 KB	-rw-r--r--	2024-03-10 20:38
bond_options.h	4.83 KB	-rw-r--r--	2026-05-26 09:55
bonding.h	21.37 KB	-rw-r--r--	2026-05-26 09:55
bpf_sk_storage.h	1.74 KB	-rw-r--r--	2024-03-10 20:38
busy_poll.h	4.28 KB	-rw-r--r--	2026-05-26 09:55
calipso.h	1.55 KB	-rw-r--r--	2024-03-10 20:38
cfg80211-wext.h	1.86 KB	-rw-r--r--	2024-03-10 20:38
cfg80211.h	336.64 KB	-rw-r--r--	2026-05-26 09:55
cfg802154.h	16.68 KB	-rw-r--r--	2026-05-26 09:55
checksum.h	4.98 KB	-rw-r--r--	2026-05-26 09:55
cipso_ipv4.h	7.37 KB	-rw-r--r--	2024-03-10 20:38
cls_cgroup.h	2.04 KB	-rw-r--r--	2026-05-26 09:55
codel.h	5.86 KB	-rw-r--r--	2024-03-10 20:38
codel_impl.h	8.3 KB	-rw-r--r--	2024-03-10 20:38
codel_qdisc.h	2.95 KB	-rw-r--r--	2024-03-10 20:38
compat.h	2.48 KB	-rw-r--r--	2024-03-10 20:38
datalink.h	590 B	-rw-r--r--	2024-03-10 20:38
dcbevent.h	766 B	-rw-r--r--	2024-03-10 20:38
dcbnl.h	4.98 KB	-rw-r--r--	2024-03-10 20:38
devlink.h	70.92 KB	-rw-r--r--	2024-03-10 20:38
dropreason-core.h	14.76 KB	-rw-r--r--	2026-05-26 09:55
dropreason.h	1.36 KB	-rw-r--r--	2024-03-10 20:38
dsa.h	41.05 KB	-rw-r--r--	2026-05-26 09:55
dsa_stubs.h	1.28 KB	-rw-r--r--	2024-03-10 20:38
dsfield.h	1.12 KB	-rw-r--r--	2024-03-10 20:38
dst.h	15.12 KB	-rw-r--r--	2026-05-26 09:55
dst_cache.h	2.96 KB	-rw-r--r--	2024-03-10 20:38
dst_metadata.h	6.34 KB	-rw-r--r--	2024-03-10 20:38
dst_ops.h	2.07 KB	-rw-r--r--	2026-05-26 09:55
erspan.h	9.04 KB	-rw-r--r--	2024-03-10 20:38
esp.h	1.18 KB	-rw-r--r--	2024-03-10 20:38
espintcp.h	966 B	-rw-r--r--	2024-03-10 20:38
ethoc.h	439 B	-rw-r--r--	2024-03-10 20:38
failover.h	1.18 KB	-rw-r--r--	2024-03-10 20:38
fib_notifier.h	1.35 KB	-rw-r--r--	2024-03-10 20:38
fib_rules.h	5.39 KB	-rw-r--r--	2024-03-10 20:38
firewire.h	599 B	-rw-r--r--	2024-03-10 20:38
flow.h	4.96 KB	-rw-r--r--	2024-03-10 20:38
flow_dissector.h	11.95 KB	-rw-r--r--	2024-03-10 20:38
flow_offload.h	17.37 KB	-rw-r--r--	2024-03-10 20:38
fou.h	578 B	-rw-r--r--	2024-03-10 20:38
fq.h	2.41 KB	-rw-r--r--	2024-03-10 20:38
fq_impl.h	7.96 KB	-rw-r--r--	2024-03-10 20:38
garp.h	2.67 KB	-rw-r--r--	2024-03-10 20:38
gen_stats.h	2.99 KB	-rw-r--r--	2024-03-10 20:38
genetlink.h	19.62 KB	-rw-r--r--	2026-05-26 09:55
geneve.h	1.84 KB	-rw-r--r--	2024-03-10 20:38
gre.h	3.29 KB	-rw-r--r--	2024-03-10 20:38
gro.h	13.38 KB	-rw-r--r--	2026-05-26 09:55
gro_cells.h	443 B	-rw-r--r--	2024-03-10 20:38
gso.h	3.2 KB	-rw-r--r--	2024-03-10 20:38
gtp.h	1.46 KB	-rw-r--r--	2024-03-10 20:38
gue.h	3.29 KB	-rw-r--r--	2024-03-10 20:38
handshake.h	1.39 KB	-rw-r--r--	2024-03-10 20:38
hwbm.h	995 B	-rw-r--r--	2024-03-10 20:38
icmp.h	1.87 KB	-rw-r--r--	2024-03-10 20:38
ieee80211_radiotap.h	23.22 KB	-rw-r--r--	2026-05-26 09:55
ieee802154_netdev.h	13.02 KB	-rw-r--r--	2024-03-10 20:38
if_inet6.h	6.6 KB	-rw-r--r--	2024-03-10 20:38
ife.h	1.03 KB	-rw-r--r--	2024-03-10 20:38
inet6_connection_sock.h	794 B	-rw-r--r--	2024-03-10 20:38
inet6_hashtables.h	5.57 KB	-rw-r--r--	2026-05-26 09:55
inet_common.h	2.83 KB	-rw-r--r--	2024-03-10 20:38
inet_connection_sock.h	11.7 KB	-rw-r--r--	2026-05-26 09:55
inet_dscp.h	1.55 KB	-rw-r--r--	2024-03-10 20:38
inet_ecn.h	7.83 KB	-rw-r--r--	2024-03-10 20:38
inet_frag.h	5.25 KB	-rw-r--r--	2026-05-26 09:55
inet_hashtables.h	16.6 KB	-rw-r--r--	2026-05-26 09:55
inet_sock.h	11.36 KB	-rw-r--r--	2026-05-26 09:55
inet_timewait_sock.h	3.71 KB	-rw-r--r--	2026-05-26 09:55
inetpeer.h	3.23 KB	-rw-r--r--	2026-05-26 09:55
ioam6.h	1.19 KB	-rw-r--r--	2024-03-10 20:38
ip.h	23.18 KB	-rw-r--r--	2026-05-26 09:55
ip6_checksum.h	2.3 KB	-rw-r--r--	2024-03-10 20:38
ip6_fib.h	17.13 KB	-rw-r--r--	2026-05-26 09:55
ip6_route.h	10.18 KB	-rw-r--r--	2026-05-26 09:55
ip6_tunnel.h	5.01 KB	-rw-r--r--	2024-03-10 20:38
ip_fib.h	16.13 KB	-rw-r--r--	2026-05-26 09:55
ip_tunnels.h	16.52 KB	-rw-r--r--	2026-05-26 09:55
ip_vs.h	53.83 KB	-rw-r--r--	2024-03-10 20:38
ipcomp.h	737 B	-rw-r--r--	2024-03-10 20:38
ipconfig.h	837 B	-rw-r--r--	2024-03-10 20:38
ipv6.h	37.58 KB	-rw-r--r--	2026-05-26 09:55
ipv6_frag.h	3.38 KB	-rw-r--r--	2024-03-10 20:38
ipv6_stubs.h	3.75 KB	-rw-r--r--	2026-05-26 09:55
iw_handler.h	20.66 KB	-rw-r--r--	2024-03-10 20:38
kcm.h	4.84 KB	-rw-r--r--	2026-05-26 09:55
l3mdev.h	7.03 KB	-rw-r--r--	2026-05-26 09:55
lag.h	409 B	-rw-r--r--	2024-03-10 20:38
lapb.h	4.82 KB	-rw-r--r--	2026-05-26 09:55
lib80211.h	3.92 KB	-rw-r--r--	2024-03-10 20:38
llc.h	4.41 KB	-rw-r--r--	2024-03-10 20:38
llc_c_ac.h	9.32 KB	-rw-r--r--	2024-03-10 20:38
llc_c_ev.h	10.61 KB	-rw-r--r--	2024-03-10 20:38
llc_c_st.h	1.77 KB	-rw-r--r--	2024-03-10 20:38
llc_conn.h	4.11 KB	-rw-r--r--	2024-03-10 20:38
llc_if.h	2.17 KB	-rw-r--r--	2024-03-10 20:38
llc_pdu.h	14.46 KB	-rw-r--r--	2024-03-10 20:38
llc_s_ac.h	1.59 KB	-rw-r--r--	2024-03-10 20:38
llc_s_ev.h	2.22 KB	-rw-r--r--	2024-03-10 20:38
llc_s_st.h	1.03 KB	-rw-r--r--	2024-03-10 20:38
llc_sap.h	1.08 KB	-rw-r--r--	2024-03-10 20:38
lwtunnel.h	6.69 KB	-rw-r--r--	2026-05-26 09:55
mac80211.h	293.16 KB	-rw-r--r--	2026-05-26 09:55
mac802154.h	14.88 KB	-rw-r--r--	2024-03-10 20:38
macsec.h	10.53 KB	-rw-r--r--	2026-05-26 09:55
mctp.h	8.03 KB	-rw-r--r--	2026-05-26 09:55
mctpdevice.h	1.26 KB	-rw-r--r--	2024-03-10 20:38
mip6.h	1016 B	-rw-r--r--	2024-03-10 20:38
mld.h	2.85 KB	-rw-r--r--	2024-03-10 20:38
mpls.h	943 B	-rw-r--r--	2024-03-10 20:38
mpls_iptunnel.h	481 B	-rw-r--r--	2024-03-10 20:38
mptcp.h	7.41 KB	-rw-r--r--	2024-03-10 20:38
mrp.h	3.13 KB	-rw-r--r--	2024-03-10 20:38
ncsi.h	1.94 KB	-rw-r--r--	2024-03-10 20:38
ndisc.h	14.64 KB	-rw-r--r--	2024-03-10 20:38
neighbour.h	16.55 KB	-rw-r--r--	2026-05-26 09:55
net_debug.h	5.08 KB	-rw-r--r--	2026-05-26 09:55
net_failover.h	1023 B	-rw-r--r--	2024-03-10 20:38
net_namespace.h	14.36 KB	-rw-r--r--	2026-05-26 09:55
net_ratelimit.h	220 B	-rw-r--r--	2024-03-10 20:38
net_trackers.h	424 B	-rw-r--r--	2024-03-10 20:38
netdev_queues.h	5.75 KB	-rw-r--r--	2024-03-10 20:38
netdev_rx_queue.h	1.32 KB	-rw-r--r--	2024-03-10 20:38
netevent.h	1.04 KB	-rw-r--r--	2024-03-10 20:38
netkit.h	1.16 KB	-rw-r--r--	2024-03-10 20:38
netlabel.h	20.15 KB	-rw-r--r--	2026-05-26 09:55
netlink.h	64.18 KB	-rw-r--r--	2024-03-10 20:38
netprio_cgroup.h	1.02 KB	-rw-r--r--	2024-03-10 20:38
netrom.h	7.73 KB	-rw-r--r--	2024-03-10 20:38
nexthop.h	11.91 KB	-rw-r--r--	2024-03-10 20:38
nl802154.h	16.04 KB	-rw-r--r--	2024-03-10 20:38
nsh.h	12.3 KB	-rw-r--r--	2024-03-10 20:38
p8022.h	403 B	-rw-r--r--	2024-03-10 20:38
pie.h	3.6 KB	-rw-r--r--	2024-03-10 20:38
ping.h	2.66 KB	-rw-r--r--	2024-03-10 20:38
pkt_cls.h	25.47 KB	-rw-r--r--	2024-03-10 20:38
pkt_sched.h	7.74 KB	-rw-r--r--	2026-05-26 09:55
pptp.h	604 B	-rw-r--r--	2024-03-10 20:38
protocol.h	3.81 KB	-rw-r--r--	2024-03-10 20:38
psample.h	1.06 KB	-rw-r--r--	2024-03-10 20:38
psnap.h	430 B	-rw-r--r--	2024-03-10 20:38
raw.h	2.46 KB	-rw-r--r--	2024-03-10 20:38
rawv6.h	862 B	-rw-r--r--	2024-03-10 20:38
red.h	11.33 KB	-rw-r--r--	2024-03-10 20:38
regulatory.h	9.96 KB	-rw-r--r--	2024-03-10 20:38
request_sock.h	6.5 KB	-rw-r--r--	2024-03-10 20:38
rose.h	8.06 KB	-rw-r--r--	2026-05-26 09:55
route.h	11.32 KB	-rw-r--r--	2026-05-26 09:55
rpl.h	749 B	-rw-r--r--	2024-03-10 20:38
rsi_91x.h	1.67 KB	-rw-r--r--	2024-03-10 20:38
rtnetlink.h	7.58 KB	-rw-r--r--	2026-05-26 09:55
rtnh.h	859 B	-rw-r--r--	2024-03-10 20:38
sch_generic.h	34.15 KB	-rw-r--r--	2026-05-26 09:55
scm.h	5.36 KB	-rw-r--r--	2026-05-26 09:55
secure_seq.h	868 B	-rw-r--r--	2024-03-10 20:38
seg6.h	2.18 KB	-rw-r--r--	2024-03-10 20:38
seg6_hmac.h	1.44 KB	-rw-r--r--	2024-03-10 20:38
seg6_local.h	644 B	-rw-r--r--	2024-03-10 20:38
selftests.h	582 B	-rw-r--r--	2024-03-10 20:38
slhc_vj.h	6.67 KB	-rw-r--r--	2024-03-10 20:38
smc.h	2.5 KB	-rw-r--r--	2026-05-26 09:55
snmp.h	5.14 KB	-rw-r--r--	2024-03-10 20:38
sock.h	85.78 KB	-rw-r--r--	2026-05-26 09:55
sock_reuseport.h	1.83 KB	-rw-r--r--	2024-03-10 20:38
stp.h	412 B	-rw-r--r--	2024-03-10 20:38
strparser.h	4.34 KB	-rw-r--r--	2026-05-26 09:55
switchdev.h	15.1 KB	-rw-r--r--	2024-03-10 20:38
tc_wrapper.h	6.29 KB	-rw-r--r--	2026-05-26 09:55
tcp.h	85.12 KB	-rw-r--r--	2026-05-26 09:55
tcp_ao.h	12.08 KB	-rw-r--r--	2026-05-26 09:55
tcp_states.h	1.3 KB	-rw-r--r--	2024-03-10 20:38
tcx.h	4.3 KB	-rw-r--r--	2026-05-26 09:55
timewait_sock.h	925 B	-rw-r--r--	2024-03-10 20:38
tipc.h	2.35 KB	-rw-r--r--	2024-03-10 20:38
tls.h	13.28 KB	-rw-r--r--	2026-05-26 09:55
tls_prot.h	1.84 KB	-rw-r--r--	2024-03-10 20:38
tls_toe.h	2.94 KB	-rw-r--r--	2024-03-10 20:38
transp_v6.h	1.88 KB	-rw-r--r--	2024-03-10 20:38
tso.h	721 B	-rw-r--r--	2024-03-10 20:38
tun_proto.h	1015 B	-rw-r--r--	2024-03-10 20:38
udp.h	15.88 KB	-rw-r--r--	2026-05-26 09:55
udp_tunnel.h	12.47 KB	-rw-r--r--	2024-03-10 20:38
udplite.h	2.3 KB	-rw-r--r--	2024-03-10 20:38
vsock_addr.h	662 B	-rw-r--r--	2024-03-10 20:38
vxlan.h	15.83 KB	-rw-r--r--	2026-05-26 09:55
wext.h	1.47 KB	-rw-r--r--	2024-03-10 20:38
x25.h	9.46 KB	-rw-r--r--	2024-03-10 20:38
x25device.h	387 B	-rw-r--r--	2024-03-10 20:38
xdp.h	15.85 KB	-rw-r--r--	2026-05-26 09:55
xdp_priv.h	427 B	-rw-r--r--	2024-03-10 20:38
xdp_sock.h	6.3 KB	-rw-r--r--	2026-05-26 09:55
xdp_sock_drv.h	9.33 KB	-rw-r--r--	2024-03-10 20:38
xfrm.h	58.29 KB	-rw-r--r--	2026-05-26 09:55
xsk_buff_pool.h	7.13 KB	-rw-r--r--	2026-05-26 09:55

Rename

#ifndef __LINUX_ERSPAN_H
#define __LINUX_ERSPAN_H

/*
 * GRE header for ERSPAN type I encapsulation (4 octets [34:37])
 *      0                   1                   2                   3
 *      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *     |0|0|0|0|0|00000|000000000|00000|    Protocol Type for ERSPAN   |
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 *  The Type I ERSPAN frame format is based on the barebones IP + GRE
 *  encapsulation (as described above) on top of the raw mirrored frame.
 *  There is no extra ERSPAN header.
 *
 *
 * GRE header for ERSPAN type II and II encapsulation (8 octets [34:41])
 *       0                   1                   2                   3
 *      0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *     |0|0|0|1|0|00000|000000000|00000|    Protocol Type for ERSPAN   |
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *     |      Sequence Number (increments per packet per session)      |
 *     +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 *  Note that in the above GRE header [RFC1701] out of the C, R, K, S,
 *  s, Recur, Flags, Version fields only S (bit 03) is set to 1. The
 *  other fields are set to zero, so only a sequence number follows.
 *
 *  ERSPAN Version 1 (Type II) header (8 octets [42:49])
 *  0                   1                   2                   3
 *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * |  Ver  |          VLAN         | COS | En|T|    Session ID     |
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * |      Reserved         |                  Index                |
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 *
 *  ERSPAN Version 2 (Type III) header (12 octets [42:49])
 *  0                   1                   2                   3
 *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * |  Ver  |          VLAN         | COS |BSO|T|     Session ID    |
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * |                          Timestamp                            |
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * |             SGT               |P|    FT   |   Hw ID   |D|Gra|O|
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 *      Platform Specific SubHeader (8 octets, optional)
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * |  Platf ID |               Platform Specific Info              |
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 * |                  Platform Specific Info                       |
 * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 * GRE proto ERSPAN type I/II = 0x88BE, type III = 0x22EB
 */

#include <linux/ip.h>
#include <linux/ipv6.h>
#include <linux/skbuff.h>
#include <uapi/linux/erspan.h>

#define ERSPAN_VERSION	0x1	/* ERSPAN type II */
#define VER_MASK	0xf000
#define VLAN_MASK	0x0fff
#define COS_MASK	0xe000
#define EN_MASK		0x1800
#define T_MASK		0x0400
#define ID_MASK		0x03ff
#define INDEX_MASK	0xfffff

#define ERSPAN_VERSION2	0x2	/* ERSPAN type III*/
#define BSO_MASK	EN_MASK
#define SGT_MASK	0xffff0000
#define P_MASK		0x8000
#define FT_MASK		0x7c00
#define HWID_MASK	0x03f0
#define DIR_MASK	0x0008
#define GRA_MASK	0x0006
#define O_MASK		0x0001

#define HWID_OFFSET    4
#define DIR_OFFSET     3

enum erspan_encap_type {
	ERSPAN_ENCAP_NOVLAN = 0x0,	/* originally without VLAN tag */
	ERSPAN_ENCAP_ISL = 0x1,		/* originally ISL encapsulated */
	ERSPAN_ENCAP_8021Q = 0x2,	/* originally 802.1Q encapsulated */
	ERSPAN_ENCAP_INFRAME = 0x3,	/* VLAN tag perserved in frame */
};

#define ERSPAN_V1_MDSIZE	4
#define ERSPAN_V2_MDSIZE	8

struct erspan_base_hdr {
#if defined(__LITTLE_ENDIAN_BITFIELD)
	__u8	vlan_upper:4,
		ver:4;
	__u8	vlan:8;
	__u8	session_id_upper:2,
		t:1,
		en:2,
		cos:3;
	__u8	session_id:8;
#elif defined(__BIG_ENDIAN_BITFIELD)
	__u8	ver: 4,
		vlan_upper:4;
	__u8	vlan:8;
	__u8	cos:3,
		en:2,
		t:1,
		session_id_upper:2;
	__u8	session_id:8;
#else
#error "Please fix <asm/byteorder.h>"
#endif
};

static inline void set_session_id(struct erspan_base_hdr *ershdr, u16 id)
{
	ershdr->session_id = id & 0xff;
	ershdr->session_id_upper = (id >> 8) & 0x3;
}

static inline u16 get_session_id(const struct erspan_base_hdr *ershdr)
{
	return (ershdr->session_id_upper << 8) + ershdr->session_id;
}

static inline void set_vlan(struct erspan_base_hdr *ershdr, u16 vlan)
{
	ershdr->vlan = vlan & 0xff;
	ershdr->vlan_upper = (vlan >> 8) & 0xf;
}

static inline u16 get_vlan(const struct erspan_base_hdr *ershdr)
{
	return (ershdr->vlan_upper << 8) + ershdr->vlan;
}

static inline void set_hwid(struct erspan_md2 *md2, u8 hwid)
{
	md2->hwid = hwid & 0xf;
	md2->hwid_upper = (hwid >> 4) & 0x3;
}

static inline u8 get_hwid(const struct erspan_md2 *md2)
{
	return (md2->hwid_upper << 4) + md2->hwid;
}

static inline int erspan_hdr_len(int version)
{
	if (version == 0)
		return 0;

return sizeof(struct erspan_base_hdr) +
	       (version == 1 ? ERSPAN_V1_MDSIZE : ERSPAN_V2_MDSIZE);
}

static inline u8 tos_to_cos(u8 tos)
{
	u8 dscp, cos;

dscp = tos >> 2;
	cos = dscp >> 3;
	return cos;
}

static inline void erspan_build_header(struct sk_buff *skb,
				u32 id, u32 index,
				bool truncate, bool is_ipv4)
{
	struct ethhdr *eth = (struct ethhdr *)skb->data;
	enum erspan_encap_type enc_type;
	struct erspan_base_hdr *ershdr;
	struct qtag_prefix {
		__be16 eth_type;
		__be16 tci;
	} *qp;
	u16 vlan_tci = 0;
	u8 tos;
	__be32 *idx;

tos = is_ipv4 ? ip_hdr(skb)->tos :
			(ipv6_hdr(skb)->priority << 4) +
			(ipv6_hdr(skb)->flow_lbl[0] >> 4);

enc_type = ERSPAN_ENCAP_NOVLAN;

/* If mirrored packet has vlan tag, extract tci and
	 *  perserve vlan header in the mirrored frame.
	 */
	if (eth->h_proto == htons(ETH_P_8021Q)) {
		qp = (struct qtag_prefix *)(skb->data + 2 * ETH_ALEN);
		vlan_tci = ntohs(qp->tci);
		enc_type = ERSPAN_ENCAP_INFRAME;
	}

skb_push(skb, sizeof(*ershdr) + ERSPAN_V1_MDSIZE);
	ershdr = (struct erspan_base_hdr *)skb->data;
	memset(ershdr, 0, sizeof(*ershdr) + ERSPAN_V1_MDSIZE);

/* Build base header */
	ershdr->ver = ERSPAN_VERSION;
	ershdr->cos = tos_to_cos(tos);
	ershdr->en = enc_type;
	ershdr->t = truncate;
	set_vlan(ershdr, vlan_tci);
	set_session_id(ershdr, id);

/* Build metadata */
	idx = (__be32 *)(ershdr + 1);
	*idx = htonl(index & INDEX_MASK);
}

/* ERSPAN GRA: timestamp granularity
 *   00b --> granularity = 100 microseconds
 *   01b --> granularity = 100 nanoseconds
 *   10b --> granularity = IEEE 1588
 * Here we only support 100 microseconds.
 */
static inline __be32 erspan_get_timestamp(void)
{
	u64 h_usecs;
	ktime_t kt;

kt = ktime_get_real();
	h_usecs = ktime_divns(kt, 100 * NSEC_PER_USEC);

/* ERSPAN base header only has 32-bit,
	 * so it wraps around 4 days.
	 */
	return htonl((u32)h_usecs);
}

/* ERSPAN BSO (Bad/Short/Oversized), see RFC1757
 *   00b --> Good frame with no error, or unknown integrity
 *   01b --> Payload is a Short Frame
 *   10b --> Payload is an Oversized Frame
 *   11b --> Payload is a Bad Frame with CRC or Alignment Error
 */
enum erspan_bso {
	BSO_NOERROR = 0x0,
	BSO_SHORT = 0x1,
	BSO_OVERSIZED = 0x2,
	BSO_BAD = 0x3,
};

static inline u8 erspan_detect_bso(struct sk_buff *skb)
{
	/* BSO_BAD is not handled because the frame CRC
	 * or alignment error information is in FCS.
	 */
	if (skb->len < ETH_ZLEN)
		return BSO_SHORT;

if (skb->len > ETH_FRAME_LEN)
		return BSO_OVERSIZED;

return BSO_NOERROR;
}

static inline void erspan_build_header_v2(struct sk_buff *skb,
					  u32 id, u8 direction, u16 hwid,
					  bool truncate, bool is_ipv4)
{
	struct ethhdr *eth = (struct ethhdr *)skb->data;
	struct erspan_base_hdr *ershdr;
	struct erspan_md2 *md2;
	struct qtag_prefix {
		__be16 eth_type;
		__be16 tci;
	} *qp;
	u16 vlan_tci = 0;
	u8 gra = 0; /* 100 usec */
	u8 bso = 0; /* Bad/Short/Oversized */
	u8 sgt = 0;
	u8 tos;

tos = is_ipv4 ? ip_hdr(skb)->tos :
			(ipv6_hdr(skb)->priority << 4) +
			(ipv6_hdr(skb)->flow_lbl[0] >> 4);

/* Unlike v1, v2 does not have En field,
	 * so only extract vlan tci field.
	 */
	if (eth->h_proto == htons(ETH_P_8021Q)) {
		qp = (struct qtag_prefix *)(skb->data + 2 * ETH_ALEN);
		vlan_tci = ntohs(qp->tci);
	}

bso = erspan_detect_bso(skb);
	skb_push(skb, sizeof(*ershdr) + ERSPAN_V2_MDSIZE);
	ershdr = (struct erspan_base_hdr *)skb->data;
	memset(ershdr, 0, sizeof(*ershdr) + ERSPAN_V2_MDSIZE);

/* Build base header */
	ershdr->ver = ERSPAN_VERSION2;
	ershdr->cos = tos_to_cos(tos);
	ershdr->en = bso;
	ershdr->t = truncate;
	set_vlan(ershdr, vlan_tci);
	set_session_id(ershdr, id);

/* Build metadata */
	md2 = (struct erspan_md2 *)(ershdr + 1);
	md2->timestamp = erspan_get_timestamp();
	md2->sgt = htons(sgt);
	md2->p = 1;
	md2->ft = 0;
	md2->dir = direction;
	md2->gra = gra;
	md2->o = 0;
	set_hwid(md2, hwid);
}

#endif