Currently, all ipv6 addresses are flushed when the interface is configured
down, including global, static addresses:
$ ip -6 addr show dev eth1
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 state UP qlen 1000
inet6 2100:1::2/120 scope global
valid_lft forever preferred_lft forever
inet6 fe80::e0:f9ff:fe79:34bd/64 scope link
valid_lft forever preferred_lft forever
$ ip link set dev eth1 down
$ ip -6 addr show dev eth1
<< nothing; all addresses have been flushed>>
Add a new sysctl to make this behavior optional. The new setting defaults to
flush all addresses to maintain backwards compatibility. When the set global
addresses with no expire times are not flushed on an admin down. The sysctl
is per-interface or system-wide for all interfaces
$ sysctl -w net.ipv6.conf.eth1.keep_addr_on_down=1
or
$ sysctl -w net.ipv6.conf.all.keep_addr_on_down=1
Will keep addresses on eth1 on an admin down.
$ ip -6 addr show dev eth1
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 state UP qlen 1000
inet6 2100:1::2/120 scope global
valid_lft forever preferred_lft forever
inet6 fe80::e0:f9ff:fe79:34bd/64 scope link
valid_lft forever preferred_lft forever
$ ip link set dev eth1 down
$ ip -6 addr show dev eth1
3: eth1: <BROADCAST,MULTICAST> mtu 1500 state DOWN qlen 1000
inet6 2100:1::2/120 scope global tentative
valid_lft forever preferred_lft forever
inet6 fe80::e0:f9ff:fe79:34bd/64 scope link tentative
valid_lft forever preferred_lft forever
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In certain 802.11 wireless deployments, there will be NA proxies
that use knowledge of the network to correctly answer requests.
To prevent unsolicitd advertisements on the shared medium from
being a problem, on such deployments wireless needs to drop them.
Enable this by providing an option called "drop_unsolicited_na".
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In order to solve a problem with 802.11, the so-called hole-196 attack,
add an option (sysctl) called "drop_unicast_in_l2_multicast" which, if
enabled, causes the stack to drop IPv6 unicast packets encapsulated in
link-layer multi- or broadcast frames. Such frames can (as an attack)
be created by any member of the same wireless network and transmitted
as valid encrypted frames since the symmetric key for broadcast frames
is shared between all stations.
Reviewed-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch addresses multiple problems :
UDP/RAW sendmsg() need to get a stable struct ipv6_txoptions
while socket is not locked : Other threads can change np->opt
concurrently. Dmitry posted a syzkaller
(http://github.com/google/syzkaller) program desmonstrating
use-after-free.
Starting with TCP/DCCP lockless listeners, tcp_v6_syn_recv_sock()
and dccp_v6_request_recv_sock() also need to use RCU protection
to dereference np->opt once (before calling ipv6_dup_options())
This patch adds full RCU protection to np->opt
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
SYN_RECV & TIMEWAIT sockets are not full blown, they do not have a pinet6
pointer.
Fixes: ca6fb06518 ("tcp: attach SYNACK messages to request sockets instead of listener")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 <gospo@cumulusnetworks.com>
Signed-off-by: Dinesh Dutt <ddutt@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 6fd99094de ("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 <liuhangbin@gmail.com>
Acked-by: YOSHIFUJI Hideaki <hideaki.yoshifuji@miraclelinux.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 <ek@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 <ek@google.com>
Cc: Fernando Gont <fgont@si6networks.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Cc: YOSHIFUJI Hideaki/吉藤英明 <hideaki.yoshifuji@miraclelinux.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 <harouth@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 <ek@google.com>
Acked-by: Lorenzo Colitti <lorenzo@google.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When an UDP application switches from AF_INET to AF_INET6 sockets, we
have a small performance degradation for IPv4 communications because of
extra cache line misses to access ipv6only information.
This can also be noticed for TCP listeners, as ipv6_only_sock() is also
used from __inet_lookup_listener()->compute_score()
This is magnified when SO_REUSEPORT is used.
Move ipv6only into struct sock_common so that it is available at
no extra cost in lookups.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This can be used in virtual networking applications, and
may have other uses as well. The option is disabled by
default.
A specific use case is setting up virtual routers, bridges, and
hosts on a single OS without the use of network namespaces or
virtual machines. With proper use of ip rules, routing tables,
veth interface pairs and/or other virtual interfaces,
and applications that can bind to interfaces and/or IP addresses,
it is possibly to create one or more virtual routers with multiple
hosts attached. The host interfaces can act as IPv6 systems,
with radvd running on the ports in the virtual routers. With the
option provided in this patch enabled, those hosts can now properly
obtain IPv6 addresses from the radvd.
Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since pktops is only used for IPv6 only and opts is used for IPv4
only, we can move these fields into a union and this allows us to drop
the inet6_reqsk_alloc function as after this change it becomes
equivalent with inet_reqsk_alloc.
This patch also fixes a kmemcheck issue in the IPv6 stack: the flags
field was not annotated after a request_sock was allocated.
Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We currently don't report IPV6_RECVPKTINFO in cmsg access ancillary data
for IPv4 datagrams on IPv6 sockets.
This patch splits the ip6_datagram_recv_ctl into two functions, one
which handles both protocol families, AF_INET and AF_INET6, while the
ip6_datagram_recv_specific_ctl only handles IPv6 cmsg data.
ip6_datagram_recv_*_ctl never reported back any errors, so we can make
them return void. Also provide a helper for protocols which don't offer dual
personality to further use ip6_datagram_recv_ctl, which is exported to
modules.
I needed to shuffle the code for ping around a bit to make it easier to
implement dual personality for ping ipv6 sockets in future.
Reported-by: Gert Doering <gert@space.net>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
With this option, the socket will reply with the flow label value read
on received packets.
The goal is to have a connection with the same flow label in both
direction of the communication.
Changelog of V4:
* Do not erase the flow label on the listening socket. Use pktopts to
store the received value
Signed-off-by: Florent Fourcot <florent.fourcot@enst-bretagne.fr>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
IPV6_PMTU_INTERFACE is the same as IPV6_PMTU_PROBE for ipv6. Add it
nontheless for symmetry with IPv4 sockets. Also drop incoming MTU
information if this mode is enabled.
The additional bit in ipv6_pinfo just eats in the padding behind the
bitfield. There are no changes to the layout of the struct at all.
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The current implementation of IPV6_FLOWINFO only gives a
result if pktoptions is available (thanks to the
ip6_datagram_recv_ctl function).
It gives inconsistent results to user space, sometimes
there is a result for getsockopt(IPV6_FLOWINFO), sometimes
not.
This patch add rcv_flowinfo to store it, and return it to
the userspace in the same way than other pkt_options.
Signed-off-by: Florent Fourcot <florent.fourcot@enst-bretagne.fr>
Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The code to detect fragments in checksum_setup() was missing for IPv4 and
too eager for IPv6. (It transpires that Windows seems to send IPv6 packets
with a fragment header even if they are not a fragment - i.e. offset is zero,
and M bit is not set).
This patch also incorporates a fix to callers of maybe_pull_tail() where
skb->network_header was being erroneously added to the length argument.
Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Cc: Wei Liu <wei.liu2@citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: David Vrabel <david.vrabel@citrix.com>
cc: David Miller <davem@davemloft.net>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The code for privacy extentions is very mature, and making it
configurable only gives marginal memory/code savings in exchange
for obfuscation and hard to read code via CPP ifdef'ery.
Signed-off-by: David S. Miller <davem@davemloft.net>
