linux/net/ipv6
Maciej Żenczykowski 2210d6b2f2 net: ipv6: sysctl to specify IPv6 ND traffic class
Add a per-device sysctl to specify the default traffic class to use for
kernel originated IPv6 Neighbour Discovery packets.

Currently this includes:

  - Router Solicitation (ICMPv6 type 133)
    ndisc_send_rs() -> ndisc_send_skb() -> ip6_nd_hdr()

  - Neighbour Solicitation (ICMPv6 type 135)
    ndisc_send_ns() -> ndisc_send_skb() -> ip6_nd_hdr()

  - Neighbour Advertisement (ICMPv6 type 136)
    ndisc_send_na() -> ndisc_send_skb() -> ip6_nd_hdr()

  - Redirect (ICMPv6 type 137)
    ndisc_send_redirect() -> ndisc_send_skb() -> ip6_nd_hdr()

and if the kernel ever gets around to generating RA's,
it would presumably also include:

  - Router Advertisement (ICMPv6 type 134)
    (radvd daemon could pick up on the kernel setting and use it)

Interface drivers may examine the Traffic Class value and translate
the DiffServ Code Point into a link-layer appropriate traffic
prioritization scheme.  An example of mapping IETF DSCP values to
IEEE 802.11 User Priority values can be found here:

    https://tools.ietf.org/html/draft-ietf-tsvwg-ieee-802-11

The expected primary use case is to properly prioritize ND over wifi.

Testing:
  jzem22:~# cat /proc/sys/net/ipv6/conf/eth0/ndisc_tclass
  0
  jzem22:~# echo -1 > /proc/sys/net/ipv6/conf/eth0/ndisc_tclass
  -bash: echo: write error: Invalid argument
  jzem22:~# echo 256 > /proc/sys/net/ipv6/conf/eth0/ndisc_tclass
  -bash: echo: write error: Invalid argument
  jzem22:~# echo 0 > /proc/sys/net/ipv6/conf/eth0/ndisc_tclass
  jzem22:~# echo 255 > /proc/sys/net/ipv6/conf/eth0/ndisc_tclass
  jzem22:~# cat /proc/sys/net/ipv6/conf/eth0/ndisc_tclass
  255
  jzem22:~# echo 34 > /proc/sys/net/ipv6/conf/eth0/ndisc_tclass
  jzem22:~# cat /proc/sys/net/ipv6/conf/eth0/ndisc_tclass
  34

  jzem22:~# echo $[0xDC] > /proc/sys/net/ipv6/conf/eth0/ndisc_tclass
  jzem22:~# tcpdump -v -i eth0 icmp6 and src host jzem22.pgc and dst host fe80::1
  tcpdump: listening on eth0, link-type EN10MB (Ethernet), capture size 262144 bytes
  IP6 (class 0xdc, hlim 255, next-header ICMPv6 (58) payload length: 24)
  jzem22.pgc > fe80::1: [icmp6 sum ok] ICMP6, neighbor advertisement,
  length 24, tgt is jzem22.pgc, Flags [solicited]

(based on original change written by Erik Kline, with minor changes)

v2: fix 'suspicious rcu_dereference_check() usage'
    by explicitly grabbing the rcu_read_lock.

Cc: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Erik Kline <ek@google.com>
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-11 15:13:02 +09:00
..
ila ila: Add a hook type for LWT routes 2017-11-08 11:20:49 +09:00
netfilter Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next 2017-11-08 14:22:50 +09:00
addrconf_core.c net: ipv6: Make inet6addr_validator a blocking notifier 2017-10-20 13:15:07 +01:00
addrconf.c net: ipv6: sysctl to specify IPv6 ND traffic class 2017-11-11 15:13:02 +09:00
addrlabel.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
af_inet6.c ipv6: Implement limits on Hop-by-Hop and Destination options 2017-11-03 09:50:22 +09:00
ah6.c ipv6: mark expected switch fall-throughs 2017-10-18 14:13:08 +01:00
anycast.c net, ipv6: convert ifacaddr6.aca_refcnt from atomic_t to refcount_t 2017-07-04 01:29:04 -07:00
calipso.c net, calipso: convert calipso_doi.refcount from atomic_t to refcount_t 2017-07-04 22:35:16 +01:00
datagram.c net: convert sock.sk_refcnt from atomic_t to refcount_t 2017-07-01 07:39:08 -07:00
esp6_offload.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-09-01 17:42:05 -07:00
esp6.c ipv6: esp6: use BUG_ON instead of if condition followed by BUG 2017-10-27 08:02:00 +02:00
exthdrs_core.c net: ipv6: remove unused code in ipv6_find_hdr() 2017-10-05 21:53:02 -07:00
exthdrs_offload.c
exthdrs.c ipv6: Implement limits on Hop-by-Hop and Destination options 2017-11-03 09:50:22 +09:00
fib6_notifier.c net: Add module reference to FIB notifiers 2017-09-01 20:33:42 -07:00
fib6_rules.c net: ipv6: avoid overhead when no custom FIB rules are installed 2017-08-08 21:40:08 -07:00
fou6.c fou: make local function static 2017-05-21 13:42:36 -04:00
icmp.c ipv6: mark expected switch fall-throughs 2017-10-18 14:13:08 +01:00
inet6_connection_sock.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-01-28 10:33:06 -05:00
inet6_hashtables.c net: ipv6: add second dif to inet6 socket lookups 2017-08-07 11:39:22 -07:00
ip6_checksum.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ip6_fib.c net: Add extack to fib_notifier_info 2017-11-01 11:50:43 +09:00
ip6_flowlabel.c ipv6: flowlabel: do not leave opt->tot_len with garbage 2017-10-22 03:22:24 +01:00
ip6_gre.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-10-30 21:09:24 +09:00
ip6_icmp.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ip6_input.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-04-20 10:35:33 -04:00
ip6_offload.c gso: fix payload length when gso_size is zero 2017-10-08 10:12:15 -07:00
ip6_offload.h
ip6_output.c ipv6: flowlabel: do not leave opt->tot_len with garbage 2017-10-22 03:22:24 +01:00
ip6_tunnel.c ip6_tunnel: Allow rcv/xmit even if remote address is a local address 2017-10-25 10:33:27 +09:00
ip6_udp_tunnel.c
ip6_vti.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-10-05 18:19:22 -07:00
ip6mr.c ipv6: mark expected switch fall-throughs 2017-10-18 14:13:08 +01:00
ipcomp6.c
ipv6_sockglue.c net-ipv6: add support for sockopt(SOL_IPV6, IPV6_FREEBIND) 2017-09-30 05:30:52 +01:00
Kconfig ipv6: sr: add helper functions for seg6local 2017-08-25 17:10:24 -07:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mcast_snoop.c
mcast.c net, ipv6: convert ifmcaddr6.mca_refcnt from atomic_t to refcount_t 2017-07-04 01:29:04 -07:00
mip6.c ktime: Get rid of ktime_equal() 2016-12-25 17:21:23 +01:00
ndisc.c net: ipv6: sysctl to specify IPv6 ND traffic class 2017-11-11 15:13:02 +09:00
netfilter.c
output_core.c ipv6: accept 64k - 1 packet length in ip6_find_1stfragopt() 2017-08-22 10:23:26 -07:00
ping.c net/ipv6: Convert icmpv6_push_pending_frames to void 2017-10-06 09:52:31 -07:00
proc.c proc: snmp6: Use correct type in memset 2017-06-12 09:53:14 -04:00
protocol.c net: Add sysctl to toggle early demux for tcp and udp 2017-03-24 13:17:07 -07:00
raw.c ipv6: mark expected switch fall-throughs 2017-10-18 14:13:08 +01:00
reassembly.c inet: frags: Convert timers to use timer_setup() 2017-10-18 12:39:55 +01:00
route.c ipv6: prevent user from adding cached routes 2017-10-29 12:18:58 +09:00
seg6_hmac.c ipv6: sr: Use ARRAY_SIZE macro 2017-09-01 18:35:23 -07:00
seg6_iptunnel.c ipv6: sr: add support for encapsulation of L2 frames 2017-08-25 17:10:23 -07:00
seg6_local.c ipv6: sr: remove duplicate routing header type check 2017-09-11 14:34:10 -07:00
seg6.c ipv6: sr: define core operations for seg6local lightweight tunnel 2017-08-07 14:16:22 -07:00
sit.c net: sit: Update lookup to handle links set to L3 slave 2017-11-01 12:35:17 +09:00
syncookies.c tcp: Namespace-ify sysctl_tcp_workaround_signed_windows 2017-10-28 19:24:38 +09:00
sysctl_net_ipv6.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
tcp_ipv6.c tcp: Namespace-ify sysctl_tcp_rmem and sysctl_tcp_wmem 2017-11-10 14:34:58 +09:00
tcpv6_offload.c
tunnel6.c
udp_impl.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
udp_offload.c net: avoid skb_warn_bad_offload false positives on UFO 2017-08-08 21:39:01 -07:00
udp.c udpv6: Fix the checksum computation when HW checksum does not apply 2017-09-18 11:43:03 -07:00
udplite.c
xfrm6_input.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xfrm6_mode_beet.c networking: make skb_pull & friends return void pointers 2017-06-16 11:48:39 -04:00
xfrm6_mode_ro.c ipv6: xfrm: Handle errors reported by xfrm6_find_1stfragopt() 2017-06-02 13:57:27 -04:00
xfrm6_mode_transport.c ipv6: xfrm: Handle errors reported by xfrm6_find_1stfragopt() 2017-06-02 13:57:27 -04:00
xfrm6_mode_tunnel.c xfrm: Add encapsulation header offsets while SKB is not encrypted 2017-04-14 10:07:39 +02:00
xfrm6_output.c xfrm: Add an IPsec hardware offloading API 2017-04-14 10:06:10 +02:00
xfrm6_policy.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-11-04 09:26:51 +09:00
xfrm6_protocol.c xfrm: input: constify xfrm_input_afinfo 2017-02-09 10:22:17 +01:00
xfrm6_state.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xfrm6_tunnel.c net, ipv6: convert xfrm6_tunnel_spi.refcnt from atomic_t to refcount_t 2017-07-04 01:29:04 -07:00