When a route needs to be appended to an existing multipath route,
fib6_add_rt2node() first appends it to the siblings list and increments
the number of sibling routes on each sibling.
Later, the function notifies the route via call_fib6_entry_notifiers().
In case the notification is vetoed, the route is not unlinked from the
siblings list, which can result in a use-after-free.
Fix this by unlinking the route from the siblings list before returning
an error.
Audited the rest of the call sites from which the FIB notification chain
is called and could not find more problems.
Fixes: 2233000cba ("net/ipv6: Move call_fib6_entry_notifiers up for route adds")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reported-by: Alexander Petrovskiy <alexpe@mellanox.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When we perform an inexact match on FIB nodes via fib6_locate_1(), longer
prefixes will be preferred to shorter ones. However, it might happen that
a node, with higher fn_bit value than some other, has no valid routing
information.
In this case, we'll pick that node, but it will be discarded by the check
on RTN_RTINFO in fib6_locate(), and we might miss nodes with valid routing
information but with lower fn_bit value.
This is apparent when a routing exception is created for a default route:
# ip -6 route list
fc00:1::/64 dev veth_A-R1 proto kernel metric 256 pref medium
fc00:2::/64 dev veth_A-R2 proto kernel metric 256 pref medium
fc00:4::1 via fc00:2::2 dev veth_A-R2 metric 1024 pref medium
fe80::/64 dev veth_A-R1 proto kernel metric 256 pref medium
fe80::/64 dev veth_A-R2 proto kernel metric 256 pref medium
default via fc00:1::2 dev veth_A-R1 metric 1024 pref medium
# ip -6 route list cache
fc00:4::1 via fc00:2::2 dev veth_A-R2 metric 1024 expires 593sec mtu 1500 pref medium
fc00:3::1 via fc00:1::2 dev veth_A-R1 metric 1024 expires 593sec mtu 1500 pref medium
# ip -6 route flush cache # node for default route is discarded
Failed to send flush request: No such process
# ip -6 route list cache
fc00:3::1 via fc00:1::2 dev veth_A-R1 metric 1024 expires 586sec mtu 1500 pref medium
Check right away if the node has a RTN_RTINFO flag, before replacing the
'prev' pointer, that indicates the longest matching prefix found so far.
Fixes: 38fbeeeecc ("ipv6: prepare fib6_locate() for exception table")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since commit 2b760fcf5c ("ipv6: hook up exception table to store dst
cache"), route exceptions reside in a separate hash table, and won't be
found by walking the FIB, so they won't be dumped to userspace on a
RTM_GETROUTE message.
This causes 'ip -6 route list cache' and 'ip -6 route flush cache' to
have no function anymore:
# ip -6 route get fc00:3::1
fc00:3::1 via fc00:1::2 dev veth_A-R1 src fc00:1::1 metric 1024 expires 539sec mtu 1400 pref medium
# ip -6 route get fc00:4::1
fc00:4::1 via fc00:2::2 dev veth_A-R2 src fc00:2::1 metric 1024 expires 536sec mtu 1500 pref medium
# ip -6 route list cache
# ip -6 route flush cache
# ip -6 route get fc00:3::1
fc00:3::1 via fc00:1::2 dev veth_A-R1 src fc00:1::1 metric 1024 expires 520sec mtu 1400 pref medium
# ip -6 route get fc00:4::1
fc00:4::1 via fc00:2::2 dev veth_A-R2 src fc00:2::1 metric 1024 expires 519sec mtu 1500 pref medium
because iproute2 lists cached routes using RTM_GETROUTE, and flushes them
by listing all the routes, and deleting them with RTM_DELROUTE one by one.
If cached routes are requested using the RTM_F_CLONED flag together with
strict checking, or if no strict checking is requested (and hence we can't
consistently apply filters), look up exceptions in the hash table
associated with the current fib6_info in rt6_dump_route(), and, if present
and not expired, add them to the dump.
We might be unable to dump all the entries for a given node in a single
message, so keep track of how many entries were handled for the current
node in fib6_walker, and skip that amount in case we start from the same
partially dumped node.
When a partial dump restarts, as the starting node might change when
'sernum' changes, we have no guarantee that we need to skip the same
amount of in-node entries. Therefore, we need two counters, and we need to
zero the in-node counter if the node from which the dump is resumed
differs.
Note that, with the current version of iproute2, this only fixes the
'ip -6 route list cache': on a flush command, iproute2 doesn't pass
RTM_F_CLONED and, due to this inconsistency, 'ip -6 route flush cache' is
still unable to fetch the routes to be flushed. This will be addressed in
a patch for iproute2.
To flush cached routes, a procfs entry could be introduced instead: that's
how it works for IPv4. We already have a rt6_flush_exception() function
ready to be wired to it. However, this would not solve the issue for
listing.
Versions of iproute2 and kernel tested:
iproute2
kernel 4.14.0 4.15.0 4.19.0 5.0.0 5.1.0 5.1.0, patched
3.18 list + + + + + +
flush + + + + + +
4.4 list + + + + + +
flush + + + + + +
4.9 list + + + + + +
flush + + + + + +
4.14 list + + + + + +
flush + + + + + +
4.15 list
flush
4.19 list
flush
5.0 list
flush
5.1 list
flush
with list + + + + + +
fix flush + + + +
v7:
- Explain usage of "skip" counters in commit message (suggested by
David Ahern)
v6:
- Rebase onto net-next, use recently introduced nexthop walker
- Make rt6_nh_dump_exceptions() a separate function (suggested by David
Ahern)
v5:
- Use dump_routes and dump_exceptions from filter, ignore NLM_F_MATCH,
update test results (flushing works with iproute2 < 5.0.0 now)
v4:
- Split NLM_F_MATCH and strict check handling in separate patches
- Filter routes using RTM_F_CLONED: if it's not set, only return
non-cached routes, and if it's set, only return cached routes:
change requested by David Ahern and Martin Lau. This implies that
iproute2 needs a separate patch to be able to flush IPv6 cached
routes. This is not ideal because we can't fix the breakage caused
by 2b760fcf5c entirely in kernel. However, two years have passed
since then, and this makes it more tolerable
v3:
- More descriptive comment about expired exceptions in rt6_dump_route()
- Swap return values of rt6_dump_route() (suggested by Martin Lau)
- Don't zero skip_in_node in case we don't dump anything in a given pass
(also suggested by Martin Lau)
- Remove check on RTM_F_CLONED altogether: in the current UAPI semantic,
it's just a flag to indicate the route was cloned, not to filter on
routes
v2: Add tracking of number of entries to be skipped in current node after
a partial dump. As we restart from the same node, if not all the
exceptions for a given node fit in a single message, the dump will
not terminate, as suggested by Martin Lau. This is a concrete
possibility, setting up a big number of exceptions for the same route
actually causes the issue, suggested by David Ahern.
Reported-by: Jianlin Shi <jishi@redhat.com>
Fixes: 2b760fcf5c ("ipv6: hook up exception table to store dst cache")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In the next patch, we are going to add optional dump of exceptions to
rt6_dump_route().
Change the return code of rt6_dump_route() to accomodate partial node
dumps: we might dump multiple routes per node, and might be able to dump
only a given number of them, so fib6_dump_node() will need to know how
many routes have been dumped on partial dump, to restart the dump from the
point where it was interrupted.
Note that fib6_dump_node() is the only caller and already handles all
non-negative return codes as success: those become -1 to signal that we're
done with the node. If we fail, return 0, as we were unable to dump the
single route in the node, but we're not done with it.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This reverts commit 08e814c9e8eb5a982cbd1e8f6bd255d97c51026f: as we
are preparing to fix listing and dumping of IPv6 cached routes, we
need to allow RTM_F_CLONED as a flag to match routes against while
dumping them.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The following patches add back the ability to dump IPv4 and IPv6 exception
routes, and we need to allow selection of regular routes or exceptions.
Use RTM_F_CLONED as filter to decide whether to dump routes or exceptions:
iproute2 passes it in dump requests (except for IPv6 cache flush requests,
this will be fixed in iproute2) and this used to work as long as
exceptions were stored directly in the FIB, for both IPv4 and IPv6.
Caveat: if strict checking is not requested (that is, if the dump request
doesn't go through ip_valid_fib_dump_req()), we can't filter on protocol,
tables or route types.
In this case, filtering on RTM_F_CLONED would be inconsistent: we would
fix 'ip route list cache' by returning exception routes and at the same
time introduce another bug in case another selector is present, e.g. on
'ip route list cache table main' we would return all exception routes,
without filtering on tables.
Keep this consistent by applying no filters at all, and dumping both
routes and exceptions, if strict checking is not requested. iproute2
currently filters results anyway, and no unwanted results will be
presented to the user. The kernel will just dump more data than needed.
v7: No changes
v6: Rebase onto net-next, no changes
v5: New patch: add dump_routes and dump_exceptions flags in filter and
simply clear the unwanted one if strict checking is enabled, don't
ignore NLM_F_MATCH and don't set filter_set if NLM_F_MATCH is set.
Skip filtering altogether if no strict checking is requested:
selecting routes or exceptions only would be inconsistent with the
fact we can't filter on tables.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch specifically converts the rule lookup logic to honor this
flag and not release refcnt when traversing each rule and calling
lookup() on each routing table.
Similar to previous patch, we also need some special handling of dst
entries in uncached list because there is always 1 refcnt taken for them
even if RT6_LOOKUP_F_DST_NOREF flag is set.
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Both listeners - mlxsw and netdevsim - of IPv6 FIB notifications are now
ready to handle IPv6 multipath notifications.
Therefore, stop ignoring such notifications in both drivers and stop
sending notification for each added / deleted nexthop.
v2:
* Remove 'multipath_rt' from 'struct fib6_entry_notifier_info'
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Extend the IPv6 FIB notifier info with number of sibling routes being
notified.
This will later allow listeners to process one notification for a
multipath routes instead of N, where N is the number of nexthops.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use nexthop_for_each_fib6_nh to walk all fib6_nh in a nexthop when
dropping 'from' reference in pcpu routes.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some ISDN files that got removed in net-next had some changes
done in mainline, take the removals.
Signed-off-by: David S. Miller <davem@davemloft.net>
Add struct nexthop and nh_list list_head to fib6_info. nh_list is the
fib6_info side of the nexthop <-> fib_info relationship. Since a fib6_info
referencing a nexthop object can not have 'sibling' entries (the old way
of doing multipath routes), the nh_list is a union with fib6_siblings.
Add f6i_list list_head to 'struct nexthop' to track fib6_info entries
using a nexthop instance. Update __remove_nexthop_fib to walk f6_list
and delete fib entries using the nexthop.
Add a few nexthop helpers for use when a nexthop is added to fib6_info:
- nexthop_fib6_nh - return first fib6_nh in a nexthop object
- fib6_info_nh_dev moved to nexthop.h and updated to use nexthop_fib6_nh
if the fib6_info references a nexthop object
- nexthop_path_fib6_result - similar to ipv4, select a path within a
multipath nexthop object. If the nexthop is a blackhole, set
fib6_result type to RTN_BLACKHOLE, and set the REJECT flag
Update the fib6_info references to check for nh and take a different path
as needed:
- rt6_qualify_for_ecmp - if a fib entry uses a nexthop object it can NOT
be coalesced with other fib entries into a multipath route
- rt6_duplicate_nexthop - use nexthop_cmp if either fib6_info references
a nexthop
- addrconf (host routes), RA's and info entries (anything configured via
ndisc) does not use nexthop objects
- fib6_info_destroy_rcu - put reference to nexthop object
- fib6_purge_rt - drop fib6_info from f6i_list
- fib6_select_path - update to use the new nexthop_path_fib6_result when
fib entry uses a nexthop object
- rt6_device_match - update to catch use of nexthop object as a blackhole
and set fib6_type and flags.
- ip6_route_info_create - don't add space for fib6_nh if fib entry is
going to reference a nexthop object, take a reference to nexthop object,
disallow use of source routing
- rt6_nlmsg_size - add space for RTA_NH_ID
- add rt6_fill_node_nexthop to add nexthop data on a dump
As with ipv4, most of the changes push existing code into the else branch
of whether the fib entry uses a nexthop object.
Update the nexthop code to walk f6i_list on a nexthop deleted to remove
fib entries referencing it.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-or-later
has been chosen to replace the boilerplate/reference in 3029 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Move fib6_nh to the end of fib6_info and make it an array of
size 0. Pass a flag to fib6_info_alloc indicating if the
allocation needs to add space for a fib6_nh.
The current code path always has a fib6_nh allocated with a
fib6_info; with nexthop objects they will be separate.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Similar to the pcpu routes exceptions are really per nexthop, so move
rt6i_exception_bucket from fib6_info to fib6_nh.
To avoid additional increases to the size of fib6_nh for a 1-bit flag,
use the lowest bit in the allocated memory pointer for the flushed flag.
Add helpers for retrieving the bucket pointer to mask off the flag.
The cleanup of the exception bucket is moved to fib6_nh_release.
fib6_nh_flush_exceptions can now be called from 2 contexts:
1. deleting a fib entry
2. deleting a fib6_nh
For 1., fib6_nh_flush_exceptions is called for a specific fib6_info that
is getting deleted. All exceptions in the cache using the entry are
deleted. For 2, the fib6_nh itself is getting destroyed so
fib6_nh_flush_exceptions is called for a NULL fib6_info which means
flush all entries.
The pmtu.sh selftest exercises the affected code paths - from creating
exceptions to cleaning them up on device delete. All tests pass without
any rcu locking or memleak warnings.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Move the existing pcpu walk in fib6_drop_pcpu_from to a new
helper, __fib6_drop_pcpu_from, that can be invoked per fib6_nh with a
reference to the from entries that need to be evicted. If the passed
in 'from' is non-NULL then only entries associated with that fib6_info
are removed (e.g., case where fib entry is deleted); if the 'from' is
NULL are entries are flushed (e.g., fib6_nh is deleted).
For fib6_info entries with builtin fib6_nh (ie., current code) there
is no change in behavior.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
rt6_info are specific instances of a fib entry and are tied to a
device and gateway - ie., a nexthop. Before nexthop objects, IPv6 fib
entries have separate fib6_info for each nexthop in a multipath route,
so the location of the pcpu cache in the fib6_info struct worked.
However, with nexthop objects a fib6_info can point to a set of nexthops
(yet another alignment of ipv6 with ipv4). Accordingly, the pcpu
cache needs to be moved to the fib6_nh struct so the cached entries
are local to the nexthop specification used to create the rt6_info.
Initialization and free of the pcpu entries moved to fib6_nh_init and
fib6_nh_release.
Change in location only, from fib6_info down to fib6_nh; no other
functional change intended.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add fib6_rt_update to send RTM_NEWROUTE with NLM_F_REPLACE set. This
helper will be used by the nexthop code to notify userspace of routes
that are impacted when a nexthop config is updated via replace.
This notification is needed for legacy apps that do not understand
the new nexthop object. Apps that are nexthop aware can use the
RTA_NH_ID attribute in the route notification to just ignore it.
In the future this should be wrapped in a sysctl to allow OS'es that
are fully updated to avoid the notificaton storm.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add hook to ipv6 stub to bump the sernum up to the root node for a
route. This is needed by the nexthop code when a nexthop config changes.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
At ipv6 route dismantle, fib6_drop_pcpu_from() is responsible
for finding all percpu routes and set their ->from pointer
to NULL, so that fib6_ref can reach its expected value (1).
The problem right now is that other cpus can still catch the
route being deleted, since there is no rcu grace period
between the route deletion and call to fib6_drop_pcpu_from()
This can leak the fib6 and associated resources, since no
notifier will take care of removing the last reference(s).
I decided to add another boolean (fib6_destroying) instead
of reusing/renaming exception_bucket_flushed to ease stable backports,
and properly document the memory barriers used to implement this fix.
This patch has been co-developped with Wei Wang.
Fixes: 93531c6743 ("net/ipv6: separate handling of FIB entries from dst based routes")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Wei Wang <weiwan@google.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Martin Lau <kafai@fb.com>
Acked-by: Wei Wang <weiwan@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We suspect some issues involving fib6_ref 0 -> 1 transitions might
cause strange syzbot reports.
Lets convert fib6_ref to refcount_t to catch them earlier.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Wei Wang <weiwan@google.com>
Acked-by: Wei Wang <weiwan@google.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Instead of using atomic_inc(), prefer fib6_info_hold()
so that upcoming refcount_t conversion is simpler.
Only fib6_info_alloc() is using atomic_set() since we
just allocated a new object.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Wei Wang <weiwan@google.com>
Acked-by: Wei Wang <weiwan@google.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We do not need to clear f6i->rt6i_exception_bucket right before
freeing f6i.
Note that f6i->rt6i_exception_bucket is properly protected by
f6i->exception_bucket_flushed being set to one in rt6_flush_exceptions()
under the protection of rt6_exception_lock.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Wei Wang <weiwan@google.com>
Acked-by: Wei Wang <weiwan@google.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Change fib6_lookup and fib6_table_lookup to take a fib6_result and set
f6i and nh rather than returning a fib6_info. For now both always
return 0.
A later patch set can make these more like the IPv4 counterparts and
return EINVAL, EACCESS, etc based on fib6_type.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Allow the gateway in a fib_nh_common to be from a different address
family than the outer fib{6}_nh. To that end, replace nhc_has_gw with
nhc_gw_family and update users of nhc_has_gw to check nhc_gw_family.
Now nhc_family is used to know if the nh_common is part of a fib_nh
or fib6_nh (used for container_of to get to route family specific data),
and nhc_gw_family represents the address family for the gateway.
Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rename fib6_nh entries that will be moved to a fib_nh_common struct.
Specifically, the device, gateway, flags, and lwtstate are common
with all nexthop definitions. In some places new temporary variables
are declared or local variables renamed to maintain line lengths.
Rename only; no functional change intended.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The gateway setting is not per fib6_info entry but per-fib6_nh. Add a new
fib_nh_has_gw flag to fib6_nh and convert references to RTF_GATEWAY to
the new flag. For IPv6 address the flag is cheaper than checking that
nh_gw is non-0 like IPv4 does.
While this increases fib6_nh by 8-bytes, the effective allocation size of
a fib6_info is unchanged. The 8 bytes is recovered later with a
fib_nh_common change.
Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Move the fib6_nh cleanup code to a new helper, fib6_nh_release.
Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Dump of a specific table with strict checking enabled is looping. The
problem is that the end of the table dump is not marked in the cb. When
dumping a specific table, cb args 0 and 1 are not used (they are the hash
index and entry with an hash table index when dumping all tables). Re-use
args[0] to hold a 'done' flag for the specific table dump.
Fixes: 13e38901d4 ("net/ipv6: Plumb support for filtering route dumps")
Reported-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Make sure we call fib6_dump_end() if it happens that skb->len
is zero. rtnl_dump_all() can reset cb->args on the next loop
iteration there.
Fixes: 08e814c9e8 ("net/ipv6: Bail early if user only wants cloned entries")
Fixes: ae677bbb44 ("net: Don't return invalid table id error when dumping all families")
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When doing a route dump across all address families, do not error out
if the table does not exist. This allows a route dump for AF_UNSPEC
with a table id that may only exist for some of the families.
Do return the table does not exist error if dumping routes for a
specific family and the table does not exist.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Similar to IPv4, IPv6 fib no longer contains cloned routes. If a user
requests a route dump for only cloned entries, no sense walking the FIB
and returning everything.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Update parsing of route dump request to enable kernel side filtering.
Allow filtering results by protocol (e.g., which routing daemon installed
the route), route type (e.g., unicast), table id and nexthop device. These
amount to the low hanging fruit, yet a huge improvement, for dumping
routes.
ip_valid_fib_dump_req is called with RTNL held, so __dev_get_by_index can
be used to look up the device index without taking a reference. From
there filter->dev is only used during dump loops with the lock still held.
Set NLM_F_DUMP_FILTERED in the answer_flags so the user knows the results
have been filtered should no entries be returned.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Implement kernel side filtering of routes by table id, egress device
index, protocol, and route type. If the table id is given in the filter,
lookup the table and call fib6_dump_table directly for it.
Move the existing route flags check for prefix only routes to the new
filter.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add struct fib_dump_filter for options on limiting which routes are
returned in a dump request. The current list is table id, protocol,
route type, rtm_flags and nexthop device index. struct net is needed
to lookup the net_device from the index.
Declare the filter for each route dump handler and plumb the new
arguments from dump handlers to ip_valid_fib_dump_req.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts were easy to resolve using immediate context mostly,
except the cls_u32.c one where I simply too the entire HEAD
chunk.
Signed-off-by: David S. Miller <davem@davemloft.net>
Another difference between IPv4 and IPv6 is the generation of RTM_DELROUTE
notifications when a device is taken down (admin down) or deleted. IPv4
does not generate a message for routes evicted by the down or delete;
IPv6 does. A NOS at scale really needs to avoid these messages and have
IPv4 and IPv6 behave similarly, relying on userspace to handle link
notifications and evict the routes.
At this point existing user behavior needs to be preserved. Since
notifications are a global action (not per app) the only way to preserve
existing behavior and allow the messages to be skipped is to add a new
sysctl (net/ipv6/route/skip_notify_on_dev_down) which can be set to
disable the notificatioons.
IPv6 route code already supports the option to skip the message (it is
used for multipath routes for example). Besides the new sysctl we need
to pass the skip_notify setting through the generic fib6_clean and
fib6_walk functions to fib6_clean_node and to set skip_notify on calls
to __ip_del_rt for the addrconf_ifdown path.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The fib6_info_alloc() function allocates percpu memory to hold per CPU
pointers to rt6_info, but this memory is never freed. Fix it.
Fixes: a64efe142f ("net/ipv6: introduce fib6_info struct and helpers")
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add helper to check netlink message for route dumps. If the strict flag
is set the dump request is expected to have an rtmsg struct as the header.
All elements of the struct are expected to be 0 with the exception of
rtm_flags (which is used by both ipv4 and ipv6 dumps) and no attributes
can be appended. rtm_flags can only have RTM_F_CLONED and RTM_F_PREFIX
set.
Update inet_dump_fib, inet6_dump_fib, mpls_dump_routes, ipmr_rtm_dumproute,
and ip6mr_rtm_dumproute to call this helper if strict data checking is
enabled.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Move the refcounting and potential free of dst metrics associated
with a fib entry to a helper and use it in both ipv4 and ipv6.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Consolidate initialization of ipv4 and ipv6 metrics when fib entries
are created into a single helper, ip_fib_metrics_init, that handles
the call to ip_metrics_convert.
If no metrics are defined for the fib entry, then the metrics is set
to dst_default_metrics.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Jan reported a regression after an update to 4.18.5. In this case ipv6
default route is setup by systemd-networkd based on data from an RA. The
RA contains an MTU of 1492 which is used when the route is first inserted
but then systemd-networkd pushes down updates to the default route
without the mtu set.
Prior to the change to fib6_info, metrics such as MTU were held in the
dst_entry and rt6i_pmtu in rt6_info contained an update to the mtu if
any. ip6_mtu would look at rt6i_pmtu first and use it if set. If not,
the value from the metrics is used if it is set and finally falling
back to the idev value.
After the fib6_info change metrics are contained in the fib6_info struct
and there is no equivalent to rt6i_pmtu. To maintain consistency with
the old behavior the new code should only reset the MTU in the metrics
if the route update has it set.
Fixes: d4ead6b34b ("net/ipv6: move metrics from dst to rt6_info")
Reported-by: Jan Janssen <medhefgo@web.de>
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Prior to the introduction of fib6_info lwtstate was managed by the dst
code. With fib6_info releasing lwtstate needs to be done when the struct
is freed.
Fixes: 93531c6743 ("net/ipv6: separate handling of FIB entries from dst based routes")
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This reverts commit df18b50448.
This change causes other problems and use-after-free situations as
found by syzbot.
Signed-off-by: David S. Miller <davem@davemloft.net>
Since commit d4ead6b34b ("net/ipv6: move metrics from dst to
rt6_info"), ipv6 metrics are shared and refcounted. rt6_set_from()
assigns the rt->from pointer and increases the refcount on from's
metrics. This reference is never released.
Introduce the fib6_metrics_release() helper and use it to release the
metrics.
Fixes: d4ead6b34b ("net/ipv6: move metrics from dst to rt6_info")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
NetworkManager likes to manage linklocal prefix routes and does so with
the NLM_F_APPEND flag, breaking attempts to simplify the IPv6 route
code and by extension enable multipath routes with device only nexthops.
Revert f34436a430 and these followup patches:
6eba08c362 ("ipv6: Only emit append events for appended routes").
ce45bded64 ("mlxsw: spectrum_router: Align with new route replace logic")
53b562df8c ("mlxsw: spectrum_router: Allow appending to dev-only routes")
Update the fib_tests cases to reflect the old behavior.
Fixes: f34436a430 ("net/ipv6: Simplify route replace and appending into multipath route")
Signed-off-by: David Ahern <dsahern@gmail.com>
Current code will emit an append event in the FIB notification chain for
any route added with NLM_F_APPEND set, even if the route was not
appended to any existing route.
This is inconsistent with IPv4 where such an event is only emitted when
the new route is appended after an existing one.
Align IPv6 behavior with IPv4, thereby allowing listeners to more easily
handle these events.
Fixes: f34436a430 ("net/ipv6: Simplify route replace and appending into multipath route")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Ido Schimmel