linux-toradex.git/include/linux/ipv6.h, branch v4.3

net: ipv6 sysctl option to ignore routes when nexthop link is down

2015-08-14T04:27:19+00:00

Like the ipv4 patch with a similar title, this adds a sysctl to allow
the user to change routing behavior based on whether or not the
interface associated with the nexthop was an up or down link.  The
default setting preserves the current behavior, but anyone that enables
it will notice that nexthops on down interfaces will no longer be
selected:

net.ipv6.conf.all.ignore_routes_with_linkdown = 0
net.ipv6.conf.default.ignore_routes_with_linkdown = 0
net.ipv6.conf.lo.ignore_routes_with_linkdown = 0
...

When the above sysctls are set, not only will link status be reported to
userspace, but an indication that a nexthop is dead and will not be used
is also reported.

1000::/8 via 7000::2 dev p7p1  metric 1024 dead linkdown  pref medium
1000::/8 via 8000::2 dev p8p1  metric 1024  pref medium
7000::/8 dev p7p1  proto kernel  metric 256 dead linkdown  pref medium
8000::/8 dev p8p1  proto kernel  metric 256  pref medium
9000::/8 via 8000::2 dev p8p1  metric 2048  pref medium
9000::/8 via 7000::2 dev p7p1  metric 1024 dead linkdown  pref medium
fe80::/64 dev p7p1  proto kernel  metric 256 dead linkdown  pref medium
fe80::/64 dev p8p1  proto kernel  metric 256  pref medium

This also adds devconf support and notification when sysctl values
change.

v2: drop use of rt6i_nhflags since it is not needed right now

Signed-off-by: Andy Gospodarek 
Signed-off-by: Dinesh Dutt 
Signed-off-by: David S. Miller

net/ipv6: add sysctl option accept_ra_min_hop_limit

2015-07-30T22:56:40+00:00

Commit 6fd99094de2b ("ipv6: Don't reduce hop limit for an interface")
disabled accept hop limit from RA if it is smaller than the current hop
limit for security stuff. But this behavior kind of break the RFC definition.

RFC 4861, 6.3.4.  Processing Received Router Advertisements
   A Router Advertisement field (e.g., Cur Hop Limit, Reachable Time,
   and Retrans Timer) may contain a value denoting that it is
   unspecified.  In such cases, the parameter should be ignored and the
   host should continue using whatever value it is already using.

   If the received Cur Hop Limit value is non-zero, the host SHOULD set
   its CurHopLimit variable to the received value.

So add sysctl option accept_ra_min_hop_limit to let user choose the minimum
hop limit value they can accept from RA. And set default to 1 to meet RFC
standards.

Signed-off-by: Hangbin Liu 
Acked-by: YOSHIFUJI Hideaki 
Signed-off-by: David S. Miller

ipv6: sysctl to restrict candidate source addresses

2015-07-22T17:54:11+00:00

Per RFC 6724, section 4, "Candidate Source Addresses":

    It is RECOMMENDED that the candidate source addresses be the set
    of unicast addresses assigned to the interface that will be used
    to send to the destination (the "outgoing" interface).

Add a sysctl to enable this behaviour.

Signed-off-by: Erik Kline 
Signed-off-by: David S. Miller

ipv6: use flag instead of u16 for hop in inet6_skb_parm

2015-07-09T22:06:59+00:00

Hop was always either 0 or sizeof(struct ipv6hdr).

Signed-off-by: Florian Westphal 
Signed-off-by: David S. Miller

ipv6: introduce secret_stable to ipv6_devconf

2015-03-24T02:12:08+00:00

This patch implements the procfs logic for the stable_address knob:
The secret is formatted as an ipv6 address and will be stored per
interface and per namespace. We track initialized flag and return EIO
errors until the secret is set.

We don't inherit the secret to newly created namespaces.

Cc: Erik Kline 
Cc: Fernando Gont 
Cc: Lorenzo Colitti 
Cc: YOSHIFUJI Hideaki/吉藤英明 
Signed-off-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller

ipv6: pull cork initialization into its own function.

2015-02-03T03:28:04+00:00

Pull IPv6 cork initialization into its own function that
can be re-used.  IPv6 specific cork data did not have an
explicit data structure.  This patch creats eone so that
just ipv6 cork data can be as arguemts.  Also, since
IPv6 tries to save the flow label into inet_cork_full
tructure, pass the full cork.

Adjust ip6_cork_release() to take cork data structures.

Signed-off-by: Vladislav Yasevich 
Signed-off-by: David S. Miller

net: ipv6: Add sysctl entry to disable MTU updates from RA

2015-01-25T22:54:41+00:00

The kernel forcefully applies MTU values received in router
advertisements provided the new MTU is less than the current. This
behavior is undesirable when the user space is managing the MTU. Instead
a sysctl flag 'accept_ra_mtu' is introduced such that the user space
can control whether or not RA provided MTU updates should be applied. The
default behavior is unchanged; user space must explicitly set this flag
to 0 for RA MTUs to be ignored.

Signed-off-by: Harout Hedeshian 
Signed-off-by: David S. Miller

ipv6: move INET6_MATCH() to include/net/inet6_hashtables.h

2014-11-05T21:59:04+00:00

It is only used in net/ipv6/inet6_hashtables.c.

Cc: David S. Miller 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller

net: ipv6: Add a sysctl to make optimistic addresses useful candidates

2014-10-29T19:11:36+00:00

Add a sysctl that causes an interface's optimistic addresses
to be considered equivalent to other non-deprecated addresses
for source address selection purposes.  Preferred addresses
will still take precedence over optimistic addresses, subject
to other ranking in the source address selection algorithm.

This is useful where different interfaces are connected to
different networks from different ISPs (e.g., a cell network
and a home wifi network).

The current behaviour complies with RFC 3484/6724, and it
makes sense if the host has only one interface, or has
multiple interfaces on the same network (same or cooperating
administrative domain(s), but not in the multiple distinct
networks case.

For example, if a mobile device has an IPv6 address on an LTE
network and then connects to IPv6-enabled wifi, while the wifi
IPv6 address is undergoing DAD, IPv6 connections will try use
the wifi default route with the LTE IPv6 address, and will get
stuck until they time out.

Also, because optimistic nodes can receive frames, issue
an RTM_NEWADDR as soon as DAD starts (with the IFA_F_OPTIMSTIC
flag appropriately set).  A second RTM_NEWADDR is sent if DAD
completes (the address flags have changed), otherwise an
RTM_DELADDR is sent.

Also: add an entry in ip-sysctl.txt for optimistic_dad.

Signed-off-by: Erik Kline 
Acked-by: Lorenzo Colitti 
Acked-by: Hannes Frederic Sowa 
Signed-off-by: David S. Miller

ipv6: Implement automatic flow label generation on transmit

2014-07-08T04:14:21+00:00

Automatically generate flow labels for IPv6 packets on transmit.
The flow label is computed based on skb_get_hash. The flow label will
only automatically be set when it is zero otherwise (i.e. flow label
manager hasn't set one). This supports the transmit side functionality
of RFC 6438.

Added an IPv6 sysctl auto_flowlabels to enable/disable this behavior
system wide, and added IPV6_AUTOFLOWLABEL socket option to enable this
functionality per socket.

By default, auto flowlabels are disabled to avoid possible conflicts
with flow label manager, however if this feature proves useful we
may want to enable it by default.

It should also be noted that FreeBSD has already implemented automatic
flow labels (including the sysctl and socket option). In FreeBSD,
automatic flow labels default to enabled.

Performance impact:

Running super_netperf with 200 flows for TCP_RR and UDP_RR for
IPv6. Note that in UDP case, __skb_get_hash will be called for
every packet with explains slight regression. In the TCP case
the hash is saved in the socket so there is no regression.

Automatic flow labels disabled:

  TCP_RR:
    86.53% CPU utilization
    127/195/322 90/95/99% latencies
    1.40498e+06 tps

  UDP_RR:
    90.70% CPU utilization
    118/168/243 90/95/99% latencies
    1.50309e+06 tps

Automatic flow labels enabled:

  TCP_RR:
    85.90% CPU utilization
    128/199/337 90/95/99% latencies
    1.40051e+06

  UDP_RR
    92.61% CPU utilization
    115/164/236 90/95/99% latencies
    1.4687e+06

Signed-off-by: Tom Herbert 
Signed-off-by: David S. Miller