We will convert rtnl_lock() with rtnl_net_lock(), and we want to
convert __in6_dev_get() too.
__in6_dev_get() uses rcu_dereference_rtnl(), but as written in its
comment, rtnl_dereference() or rcu_dereference() is preferable.
Let's add __in6_dev_get_rtnl_net() that uses rtnl_net_dereference().
We can add the RCU version helper later if needed.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250115080608.28127-2-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This change introduces a mechanism for notifying userspace
applications about changes to IPv6 anycast addresses via netlink. It
includes:
* Addition and deletion of IPv6 anycast addresses are reported using
RTM_NEWANYCAST and RTM_DELANYCAST.
* A new netlink group (RTNLGRP_IPV6_ACADDR) for subscribing to these
notifications.
This enables user space applications(e.g. ip monitor) to efficiently
track anycast addresses through netlink messages, improving metrics
collection and system monitoring. It also unlocks the potential for
advanced anycast management in user space, such as hardware offload
control and fine grained network control.
Cc: Maciej Żenczykowski <maze@google.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Yuyang Huang <yuyanghuang@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20250107114355.1766086-1-yuyanghuang@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
This change introduces netlink notifications for multicast address
changes. The following features are included:
* Addition and deletion of multicast addresses are reported using
RTM_NEWMULTICAST and RTM_DELMULTICAST messages with AF_INET and
AF_INET6.
* Two new notification groups: RTNLGRP_IPV4_MCADDR and
RTNLGRP_IPV6_MCADDR are introduced for receiving these events.
This change allows user space applications (e.g., ip monitor) to
efficiently track multicast group memberships by listening for netlink
events. Previously, applications relied on inefficient polling of
procfs, introducing delays. With netlink notifications, applications
receive realtime updates on multicast group membership changes,
enabling more precise metrics collection and system monitoring.
This change also unlocks the potential for implementing a wide range
of sophisticated multicast related features in user space by allowing
applications to combine kernel provided multicast address information
with user space data and communicate decisions back to the kernel for
more fine grained control. This mechanism can be used for various
purposes, including multicast filtering, IGMP/MLD offload, and
IGMP/MLD snooping.
Cc: Maciej Żenczykowski <maze@google.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Co-developed-by: Patrick Ruddy <pruddy@vyatta.att-mail.com>
Signed-off-by: Patrick Ruddy <pruddy@vyatta.att-mail.com>
Link: https://lore.kernel.org/r/20180906091056.21109-1-pruddy@vyatta.att-mail.com
Signed-off-by: Yuyang Huang <yuyanghuang@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
INFINITY_LIFE_TIME is the common value used in IPv4 and IPv6 but defined
in both .c files.
Also, 0xffffffff used in addrconf_timeout_fixup() is INFINITY_LIFE_TIME.
Let's move INFINITY_LIFE_TIME's definition to addrconf.h
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20240809235406.50187-6-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
draft-ietf-6man-pio-pflag is adding a new flag to the Prefix Information
Option to signal that the network can allocate a unique IPv6 prefix per
client via DHCPv6-PD (see draft-ietf-v6ops-dhcp-pd-per-device).
When ra_honor_pio_pflag is enabled, the presence of a P-flag causes
SLAAC autoconfiguration to be disabled for that particular PIO.
An automated test has been added in Android (r.android.com/3195335) to
go along with this change.
Cc: Maciej Żenczykowski <maze@google.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Cc: David Lamparter <equinox@opensourcerouting.org>
Cc: Simon Horman <horms@kernel.org>
Signed-off-by: Patrick Rohr <prohr@google.com>
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
idev->cnf.ignore_routes_with_linkdown can be used without any locks,
add appropriate annotations.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In RFC 8981, REGEN_ADVANCE cannot be less than 2 seconds, and the RFC
does not permit the creation of temporary addresses with lifetimes
shorter than that:
> When processing a Router Advertisement with a
> Prefix Information option carrying a prefix for the purposes of
> address autoconfiguration (i.e., the A bit is set), the host MUST
> perform the following steps:
> 5. A temporary address is created only if this calculated preferred
> lifetime is greater than REGEN_ADVANCE time units.
However, some users want to change their IPv6 address as frequently as
possible regardless of the RFC's arbitrary minimum lifetime. For the
benefit of those users, add a regen_min_advance sysctl parameter that
can be set to below or above 2 seconds.
Link: https://datatracker.ietf.org/doc/html/rfc8981
Signed-off-by: Alex Henrie <alexhenrie24@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Lorenzo points out that we effectively clear all unknown
flags from PIO when copying them to userspace in the netlink
RTM_NEWPREFIX notification.
We could fix this one at a time as new flags are defined,
or in one fell swoop - I choose the latter.
We could either define 6 new reserved flags (reserved1..6) and handle
them individually (and rename them as new flags are defined), or we
could simply copy the entire unmodified byte over - I choose the latter.
This unfortunately requires some anonymous union/struct magic,
so we add a static assert on the struct size for a little extra safety.
Cc: David Ahern <dsahern@kernel.org>
Cc: Lorenzo Colitti <lorenzo@google.com>
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Change net device's MTU to smaller than IPV6_MIN_MTU or unregister
device while matching route. That may trigger null-ptr-deref bug
for ip6_ptr probability as following.
=========================================================
BUG: KASAN: null-ptr-deref in find_match.part.0+0x70/0x134
Read of size 4 at addr 0000000000000308 by task ping6/263
CPU: 2 PID: 263 Comm: ping6 Not tainted 5.19.0-rc7+ #14
Call trace:
dump_backtrace+0x1a8/0x230
show_stack+0x20/0x70
dump_stack_lvl+0x68/0x84
print_report+0xc4/0x120
kasan_report+0x84/0x120
__asan_load4+0x94/0xd0
find_match.part.0+0x70/0x134
__find_rr_leaf+0x408/0x470
fib6_table_lookup+0x264/0x540
ip6_pol_route+0xf4/0x260
ip6_pol_route_output+0x58/0x70
fib6_rule_lookup+0x1a8/0x330
ip6_route_output_flags_noref+0xd8/0x1a0
ip6_route_output_flags+0x58/0x160
ip6_dst_lookup_tail+0x5b4/0x85c
ip6_dst_lookup_flow+0x98/0x120
rawv6_sendmsg+0x49c/0xc70
inet_sendmsg+0x68/0x94
Reproducer as following:
Firstly, prepare conditions:
$ip netns add ns1
$ip netns add ns2
$ip link add veth1 type veth peer name veth2
$ip link set veth1 netns ns1
$ip link set veth2 netns ns2
$ip netns exec ns1 ip -6 addr add 2001:0db8:0:f101::1/64 dev veth1
$ip netns exec ns2 ip -6 addr add 2001:0db8:0:f101::2/64 dev veth2
$ip netns exec ns1 ifconfig veth1 up
$ip netns exec ns2 ifconfig veth2 up
$ip netns exec ns1 ip -6 route add 2000::/64 dev veth1 metric 1
$ip netns exec ns2 ip -6 route add 2001::/64 dev veth2 metric 1
Secondly, execute the following two commands in two ssh windows
respectively:
$ip netns exec ns1 sh
$while true; do ip -6 addr add 2001:0db8:0:f101::1/64 dev veth1; ip -6 route add 2000::/64 dev veth1 metric 1; ping6 2000::2; done
$ip netns exec ns1 sh
$while true; do ip link set veth1 mtu 1000; ip link set veth1 mtu 1500; sleep 5; done
It is because ip6_ptr has been assigned to NULL in addrconf_ifdown() firstly,
then ip6_ignore_linkdown() accesses ip6_ptr directly without NULL check.
cpu0 cpu1
fib6_table_lookup
__find_rr_leaf
addrconf_notify [ NETDEV_CHANGEMTU ]
addrconf_ifdown
RCU_INIT_POINTER(dev->ip6_ptr, NULL)
find_match
ip6_ignore_linkdown
So we can add NULL check for ip6_ptr before using in ip6_ignore_linkdown() to
fix the null-ptr-deref bug.
Fixes: dcd1f57295 ("net/ipv6: Remove fib6_idev")
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20220728013307.656257-1-william.xuanziyang@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch adds a new protocol attribute to IPv4 and IPv6 addresses.
Inspiration was taken from the protocol attribute of routes. User space
applications like iproute2 can set/get the protocol with the Netlink API.
The attribute is stored as an 8-bit unsigned integer.
The protocol attribute is set by kernel for these categories:
- IPv4 and IPv6 loopback addresses
- IPv6 addresses generated from router announcements
- IPv6 link local addresses
User space may pass custom protocols, not defined by the kernel.
Grouping addresses on their origin is useful in scenarios where you want
to distinguish between addresses based on who added them, e.g. kernel
vs. user space.
Tagging addresses with a string label is an existing feature that could be
used as a solution. Unfortunately the max length of a label is
15 characters, and for compatibility reasons the label must be prefixed
with the name of the device followed by a colon. Since device names also
have a max length of 15 characters, only -1 characters is guaranteed to be
available for any origin tag, which is not that much.
A reference implementation of user space setting and getting protocols
is available for iproute2:
https://github.com/westermo/iproute2/commit/9a6ea18bd79f47f293e5edc7780f315ea42ff540
Signed-off-by: Jacques de Laval <Jacques.De.Laval@westermo.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20220217150202.80802-1-Jacques.De.Laval@westermo.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This reverts commit b75326c201.
This commit breaks Linux compatibility with USGv6 tests. The RFC this
commit was based on is actually an expired draft: no published RFC
currently allows the new behaviour it introduced.
Without full IETF endorsement, the flash renumbering scenario this
patch was supposed to enable is never going to work, as other IPv6
equipements on the same LAN will keep the 2 hours limit.
Fixes: b75326c201 ("ipv6: Honor all IPv6 PIO Valid Lifetime values")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The IPv6 Multicast Router Advertisements parsing has the following two
issues:
For one thing, ICMPv6 MRD Advertisements are smaller than ICMPv6 MLD
messages (ICMPv6 MRD Adv.: 8 bytes vs. ICMPv6 MLDv1/2: >= 24 bytes,
assuming MLDv2 Reports with at least one multicast address entry).
When ipv6_mc_check_mld_msg() tries to parse an Multicast Router
Advertisement its MLD length check will fail - and it will wrongly
return -EINVAL, even if we have a valid MRD Advertisement. With the
returned -EINVAL the bridge code will assume a broken packet and will
wrongly discard it, potentially leading to multicast packet loss towards
multicast routers.
The second issue is the MRD header parsing in
br_ip6_multicast_mrd_rcv(): It wrongly checks for an ICMPv6 header
immediately after the IPv6 header (IPv6 next header type). However
according to RFC4286, section 2 all MRD messages contain a Router Alert
option (just like MLD). So instead there is an IPv6 Hop-by-Hop option
for the Router Alert between the IPv6 and ICMPv6 header, again leading
to the bridge wrongly discarding Multicast Router Advertisements.
To fix these two issues, introduce a new return value -ENODATA to
ipv6_mc_check_mld() to indicate a valid ICMPv6 packet with a hop-by-hop
option which is not an MLD but potentially an MRD packet. This also
simplifies further parsing in the bridge code, as ipv6_mc_check_mld()
already fully checks the ICMPv6 header and hop-by-hop option.
These issues were found and fixed with the help of the mrdisc tool
(https://github.com/troglobit/mrdisc).
Fixes: 4b3087c7e3 ("bridge: Snoop Multicast Router Advertisements")
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch is to do 3 things for ipv6_dev_find():
As David A. noticed,
- rt6_lookup() is not really needed. Different from __ip_dev_find(),
ipv6_dev_find() doesn't have a compatibility problem, so remove it.
As Hideaki suggested,
- "valid" (non-tentative) check for the address is also needed.
ipv6_chk_addr() calls ipv6_chk_addr_and_flags(), which will
traverse the address hash list, but it's heavy to be called
inside ipv6_dev_find(). This patch is to reuse the code of
ipv6_chk_addr_and_flags() for ipv6_dev_find().
- dev parameter is passed into ipv6_dev_find(), as link-local
addresses from user space has sin6_scope_id set and the dev
lookup needs it.
Fixes: 81f6cb3122 ("ipv6: add ipv6_dev_find()")
Suggested-by: YOSHIFUJI Hideaki <hideaki.yoshifuji@miraclelinux.com>
Reported-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is to add an ip_dev_find like function for ipv6, used to find
the dev by saddr.
It will be used by TIPC protocol. So also export it.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
IPV6_ADDRFORM causes resource leaks when converting an IPv6 socket
to IPv4, particularly struct ipv6_ac_socklist. Similar to
struct ipv6_mc_socklist, we should just close it on this path.
This bug can be easily reproduced with the following C program:
#include <stdio.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <arpa/inet.h>
int main()
{
int s, value;
struct sockaddr_in6 addr;
struct ipv6_mreq m6;
s = socket(AF_INET6, SOCK_DGRAM, 0);
addr.sin6_family = AF_INET6;
addr.sin6_port = htons(5000);
inet_pton(AF_INET6, "::ffff:192.168.122.194", &addr.sin6_addr);
connect(s, (struct sockaddr *)&addr, sizeof(addr));
inet_pton(AF_INET6, "fe80::AAAA", &m6.ipv6mr_multiaddr);
m6.ipv6mr_interface = 5;
setsockopt(s, SOL_IPV6, IPV6_JOIN_ANYCAST, &m6, sizeof(m6));
value = AF_INET;
setsockopt(s, SOL_IPV6, IPV6_ADDRFORM, &value, sizeof(value));
close(s);
return 0;
}
Reported-by: ch3332xr@gmail.com
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
RFC4862 5.5.3 e) prevents received Router Advertisements from reducing
the Valid Lifetime of configured addresses to less than two hours, thus
preventing hosts from reacting to the information provided by a router
that has positive knowledge that a prefix has become invalid.
This patch makes hosts honor all Valid Lifetime values, as per
draft-gont-6man-slaac-renum-06, Section 4.2. This is meant to help
mitigate the problem discussed in draft-ietf-v6ops-slaac-renum.
Note: Attacks aiming at disabling an advertised prefix via a Valid
Lifetime of 0 are not really more harmful than other attacks
that can be performed via forged RA messages, such as those
aiming at completely disabling a next-hop router via an RA that
advertises a Router Lifetime of 0, or performing a Denial of
Service (DoS) attack by advertising illegitimate prefixes via
forged PIOs. In scenarios where RA-based attacks are of concern,
proper mitigations such as RA-Guard [RFC6105] [RFC7113] should
be implemented.
Signed-off-by: Fernando Gont <fgont@si6networks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds a functionality to addrconf to check on a specific RPL
address configuration. According to RFC 6554:
To detect loops in the SRH, a router MUST determine if the SRH
includes multiple addresses assigned to any interface on that
router. If such addresses appear more than once and are separated by
at least one address not assigned to that router.
Signed-off-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The sparse commit 6002ded74587 ("add a flag to warn on casts to/from
bitwise pointers") introduced a check for non-direct casts from/to
restricted datatypes (when -Wbitwise-pointer is enabled).
This triggered a warning in the 64 bit optimized ipv6_addr_is_*() functions
because sparse doesn't know that the buffer already points to some data in
the correct bitwise integer format. But these were correct and can
therefore be marked with __force to signalize sparse an intended cast to a
specific bitwise type.
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fernando Fernandez Mancera
Kuniyuki Iwashima
Kuniyuki Iwashima
Yuyang Huang
Simon Horman
Patrick Rohr
Jiri Benc
Eric Dumazet
Alex Henrie
Maciej Żenczykowski
Ziyang Xuan
Jacques de Laval
Ignat Korchagin
Guillaume Nault
Linus Lüssing
Xin Long
Cong Wang
Fernando Gont
Alexander Aring
Sven Eckelmann
David S. Miller