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An netadmin inside container can use 'ip a a' and 'ip r a'
to assign a large number of ipv4/ipv6 addresses and routing entries
and force kernel to allocate megabytes of unaccounted memory
for long-lived per-netdevice related kernel objects:
'struct in_ifaddr', 'struct inet6_ifaddr', 'struct fib6_node',
'struct rt6_info', 'struct fib_rules' and ip_fib caches.
These objects can be manually removed, though usually they lives
in memory till destroy of its net namespace.
It makes sense to account for them to restrict the host's memory
consumption from inside the memcg-limited container.
One of such objects is the 'struct fib6_node' mostly allocated in
net/ipv6/route.c::__ip6_ins_rt() inside the lock_bh()/unlock_bh() section:
write_lock_bh(&table->tb6_lock);
err = fib6_add(&table->tb6_root, rt, info, mxc);
write_unlock_bh(&table->tb6_lock);
In this case it is not enough to simply add SLAB_ACCOUNT to corresponding
kmem cache. The proper memory cgroup still cannot be found due to the
incorrect 'in_interrupt()' check used in memcg_kmem_bypass().
Obsoleted in_interrupt() does not describe real execution context properly.
>From include/linux/preempt.h:
The following macros are deprecated and should not be used in new code:
in_interrupt() - We're in NMI,IRQ,SoftIRQ context or have BH disabled
To verify the current execution context new macro should be used instead:
in_task() - We're in task context
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
A subsequent patch will add a new multipath hash policy where the packet
fields used for multipath hash calculation are determined by user space.
This patch adds a sysctl that allows user space to set these fields.
The packet fields are represented using a bitmask and are common between
IPv4 and IPv6 to allow user space to use the same numbering across both
protocols. For example, to hash based on standard 5-tuple:
# sysctl -w net.ipv6.fib_multipath_hash_fields=0x0037
net.ipv6.fib_multipath_hash_fields = 0x0037
To avoid introducing holes in 'struct netns_sysctl_ipv6', move the
'bindv6only' field after the multipath hash fields.
The kernel rejects unknown fields, for example:
# sysctl -w net.ipv6.fib_multipath_hash_fields=0x1000
sysctl: setting key "net.ipv6.fib_multipath_hash_fields": Invalid argument
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The 'out_timer' label was added in commit 63152fc0de ("[NETNS][IPV6]
ip6_fib - gc timer per namespace") when the timer was allocated on the
heap.
Commit 417f28bb34 ("netns: dont alloc ipv6 fib timer list") removed
the allocation, but kept the label name.
Rename it to a more suitable name.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The function fib6_walk_continue() cannot return a positive value when
called from register_fib_notifier(), but ignoring causes static analyzer to
generate warnings in users of register_fib_notifier() that try to convert
returned error code to pointer with ERR_PTR(). Handle such case by
explicitly checking for positive error values and converting them to
-EINVAL in fib6_tables_dump().
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Suggested-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Vlad Buslov <vladbu@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Route removal is handled by two code paths. The main removal path is via
fib6_del_route() which will handle purging any PMTU exceptions from the
cache, removing all per-cpu copies of the DST entry used by the route, and
releasing the fib6_info struct.
The second removal location is during fib6_add_rt2node() during a route
replacement operation. This path also calls fib6_purge_rt() to handle
cleaning up the per-cpu copies of the DST entries and releasing the
fib6_info associated with the older route, but it does not flush any PMTU
exceptions that the older route had. Since the older route is removed from
the tree during the replacement, we lose any way of accessing it again.
As these lingering DSTs and the fib6_info struct are holding references to
the underlying netdevice struct as well, unregistering that device from the
kernel can never complete.
Fixes: 2b760fcf5c ("ipv6: hook up exception table to store dst cache")
Signed-off-by: Sean Tranchetti <stranche@codeaurora.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/1609892546-11389-1-git-send-email-stranche@quicinc.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Minor conflicts in net/mptcp/protocol.h and
tools/testing/selftests/net/Makefile.
In both cases code was added on both sides in the same place
so just keep both.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit 4fc427e051 ("ipv6_route_seq_next should increase position index")
tried to fix the issue where seq_file pos is not increased
if a NULL element is returned with seq_ops->next(). See bug
https://bugzilla.kernel.org/show_bug.cgi?id=206283
The commit effectively does:
- increase pos for all seq_ops->start()
- increase pos for all seq_ops->next()
For ipv6_route, increasing pos for all seq_ops->next() is correct.
But increasing pos for seq_ops->start() is not correct
since pos is used to determine how many items to skip during
seq_ops->start():
iter->skip = *pos;
seq_ops->start() just fetches the *current* pos item.
The item can be skipped only after seq_ops->show() which essentially
is the beginning of seq_ops->next().
For example, I have 7 ipv6 route entries,
root@arch-fb-vm1:~/net-next dd if=/proc/net/ipv6_route bs=4096
00000000000000000000000000000000 40 00000000000000000000000000000000 00 00000000000000000000000000000000 00000400 00000001 00000000 00000001 eth0
fe800000000000000000000000000000 40 00000000000000000000000000000000 00 00000000000000000000000000000000 00000100 00000001 00000000 00000001 eth0
00000000000000000000000000000000 00 00000000000000000000000000000000 00 00000000000000000000000000000000 ffffffff 00000001 00000000 00200200 lo
00000000000000000000000000000001 80 00000000000000000000000000000000 00 00000000000000000000000000000000 00000000 00000003 00000000 80200001 lo
fe800000000000002050e3fffebd3be8 80 00000000000000000000000000000000 00 00000000000000000000000000000000 00000000 00000002 00000000 80200001 eth0
ff000000000000000000000000000000 08 00000000000000000000000000000000 00 00000000000000000000000000000000 00000100 00000004 00000000 00000001 eth0
00000000000000000000000000000000 00 00000000000000000000000000000000 00 00000000000000000000000000000000 ffffffff 00000001 00000000 00200200 lo
0+1 records in
0+1 records out
1050 bytes (1.0 kB, 1.0 KiB) copied, 0.00707908 s, 148 kB/s
root@arch-fb-vm1:~/net-next
In the above, I specify buffer size 4096, so all records can be returned
to user space with a single trip to the kernel.
If I use buffer size 128, since each record size is 149, internally
kernel seq_read() will read 149 into its internal buffer and return the data
to user space in two read() syscalls. Then user read() syscall will trigger
next seq_ops->start(). Since the current implementation increased pos even
for seq_ops->start(), it will skip record #2, #4 and #6, assuming the first
record is #1.
root@arch-fb-vm1:~/net-next dd if=/proc/net/ipv6_route bs=128
00000000000000000000000000000000 40 00000000000000000000000000000000 00 00000000000000000000000000000000 00000400 00000001 00000000 00000001 eth0
00000000000000000000000000000000 00 00000000000000000000000000000000 00 00000000000000000000000000000000 ffffffff 00000001 00000000 00200200 lo
fe800000000000002050e3fffebd3be8 80 00000000000000000000000000000000 00 00000000000000000000000000000000 00000000 00000002 00000000 80200001 eth0
00000000000000000000000000000000 00 00000000000000000000000000000000 00 00000000000000000000000000000000 ffffffff 00000001 00000000 00200200 lo
4+1 records in
4+1 records out
600 bytes copied, 0.00127758 s, 470 kB/s
To fix the problem, create a fake pos pointer so seq_ops->start()
won't actually increase seq_file pos. With this fix, the
above `dd` command with `bs=128` will show correct result.
Fixes: 4fc427e051 ("ipv6_route_seq_next should increase position index")
Cc: Alexei Starovoitov <ast@kernel.org>
Suggested-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Two minor conflicts:
1) net/ipv4/route.c, adding a new local variable while
moving another local variable and removing it's
initial assignment.
2) drivers/net/dsa/microchip/ksz9477.c, overlapping changes.
One pretty prints the port mode differently, whilst another
changes the driver to try and obtain the port mode from
the port node rather than the switch node.
Signed-off-by: David S. Miller <davem@davemloft.net>
It was reported that a considerable amount of cycles were spent on the
expensive indirect calls on fib6_rule_lookup. This patch introduces an
inline helper called pol_route_func that uses the indirect_call_wrappers
to avoid the indirect calls.
This patch saves around 50ns per call.
Performance was measured on the receiver by checking the amount of
syncookies that server was able to generate under a synflood load.
Traffic was generated using trafgen[1] which was pushing around 1Mpps on
a single queue. Receiver was using only one rx queue which help to
create a bottle neck and make the experiment rx-bounded.
These are the syncookies generated over 10s from the different runs:
Whithout the patch:
TcpExtSyncookiesSent 3553749 0.0
TcpExtSyncookiesSent 3550895 0.0
TcpExtSyncookiesSent 3553845 0.0
TcpExtSyncookiesSent 3541050 0.0
TcpExtSyncookiesSent 3539921 0.0
TcpExtSyncookiesSent 3557659 0.0
TcpExtSyncookiesSent 3526812 0.0
TcpExtSyncookiesSent 3536121 0.0
TcpExtSyncookiesSent 3529963 0.0
TcpExtSyncookiesSent 3536319 0.0
With the patch:
TcpExtSyncookiesSent 3611786 0.0
TcpExtSyncookiesSent 3596682 0.0
TcpExtSyncookiesSent 3606878 0.0
TcpExtSyncookiesSent 3599564 0.0
TcpExtSyncookiesSent 3601304 0.0
TcpExtSyncookiesSent 3609249 0.0
TcpExtSyncookiesSent 3617437 0.0
TcpExtSyncookiesSent 3608765 0.0
TcpExtSyncookiesSent 3620205 0.0
TcpExtSyncookiesSent 3601895 0.0
Without the patch the average is 354263 pkt/s or 2822 ns/pkt and with
the patch the average is 360738 pkt/s or 2772 ns/pkt which gives an
estimate of 50 ns per packet.
[1] http://netsniff-ng.org/
Changelog since v1:
- Change ordering in the ICW (Paolo Abeni)
Cc: Luigi Rizzo <lrizzo@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Brian Vazquez <brianvv@google.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The MSCC bug fix in 'net' had to be slightly adjusted because the
register accesses are done slightly differently in net-next.
Signed-off-by: David S. Miller <davem@davemloft.net>
In case we can't find a ->dumpit callback for the requested
(family,type) pair, we fall back to (PF_UNSPEC,type). In effect, we're
in the same situation as if userspace had requested a PF_UNSPEC
dump. For RTM_GETROUTE, that handler is rtnl_dump_all, which calls all
the registered RTM_GETROUTE handlers.
The requested table id may or may not exist for all of those
families. commit ae677bbb44 ("net: Don't return invalid table id
error when dumping all families") fixed the problem when userspace
explicitly requests a PF_UNSPEC dump, but missed the fallback case.
For example, when we pass ipv6.disable=1 to a kernel with
CONFIG_IP_MROUTE=y and CONFIG_IP_MROUTE_MULTIPLE_TABLES=y,
the (PF_INET6, RTM_GETROUTE) handler isn't registered, so we end up in
rtnl_dump_all, and listing IPv6 routes will unexpectedly print:
# ip -6 r
Error: ipv4: MR table does not exist.
Dump terminated
commit ae677bbb44 introduced the dump_all_families variable, which
gets set when userspace requests a PF_UNSPEC dump. However, we can't
simply set the family to PF_UNSPEC in rtnetlink_rcv_msg in the
fallback case to get dump_all_families == true, because some messages
types (for example RTM_GETRULE and RTM_GETNEIGH) only register the
PF_UNSPEC handler and use the family to filter in the kernel what is
dumped to userspace. We would then export more entries, that userspace
would have to filter. iproute does that, but other programs may not.
Instead, this patch removes dump_all_families and updates the
RTM_GETROUTE handlers to check if the family that is being dumped is
their own. When it's not, which covers both the intentional PF_UNSPEC
dumps (as dump_all_families did) and the fallback case, ignore the
missing table id error.
Fixes: cb167893f4 ("net: Plumb support for filtering ipv4 and ipv6 multicast route dumps")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit b121b341e5 ("bpf: Add PTR_TO_BTF_ID_OR_NULL
support") adds a field btf_id_or_null_non0_off to
bpf_prog->aux structure to indicate that the
first ctx argument is PTR_TO_BTF_ID reg_type and
all others are PTR_TO_BTF_ID_OR_NULL.
This approach does not really scale if we have
other different reg types in the future, e.g.,
a pointer to a buffer.
This patch enables bpf_iter targets registering ctx argument
reg types which may be different from the default one.
For example, for pointers to structures, the default reg_type
is PTR_TO_BTF_ID for tracing program. The target can register
a particular pointer type as PTR_TO_BTF_ID_OR_NULL which can
be used by the verifier to enforce accesses.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200513180221.2949882-1-yhs@fb.com
This patch added netlink and ipv6_route targets, using
the same seq_ops (except show() and minor changes for stop())
for /proc/net/{netlink,ipv6_route}.
The net namespace for these targets are the current net
namespace at file open stage, similar to
/proc/net/{netlink,ipv6_route} reference counting
the net namespace at seq_file open stage.
Since module is not supported for now, ipv6_route is
supported only if the IPV6 is built-in, i.e., not compiled
as a module. The restriction can be lifted once module
is properly supported for bpf_iter.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175910.2476329-1-yhs@fb.com
Convert the various uses of fallthrough comments to fallthrough;
Done via script
Link: https://lore.kernel.org/lkml/b56602fcf79f849e733e7b521bb0e17895d390fa.1582230379.git.joe@perches.com/
And by hand:
net/ipv6/ip6_fib.c has a fallthrough comment outside of an #ifdef block
that causes gcc to emit a warning if converted in-place.
So move the new fallthrough; inside the containing #ifdef/#endif too.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After commit 2759647247 ("ipv6: fix ECMP route replacement") it is no
longer possible to replace an ECMP-able route by a non ECMP-able route.
For example,
ip route add 2001:db8::1/128 via fe80::1 dev dummy0
ip route replace 2001:db8::1/128 dev dummy0
does not work as expected.
Tweak the replacement logic so that point 3 in the log of the above commit
becomes:
3. If the new route is not ECMP-able, and no matching non-ECMP-able route
exists, replace matching ECMP-able route (if any) or add the new route.
We can now summarize the entire replace semantics to:
When doing a replace, prefer replacing a matching route of the same
"ECMP-able-ness" as the replace argument. If there is no such candidate,
fallback to the first route found.
Fixes: 2759647247 ("ipv6: fix ECMP route replacement")
Signed-off-by: Benjamin Poirier <bpoirier@cumulusnetworks.com>
Reviewed-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
if seq_file .next fuction does not change position index,
read after some lseek can generate unexpected output.
https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Now that mlxsw is converted to use the new FIB notifications it is
possible to delete the old ones and use the new replace / append /
delete notifications.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
For the purpose of route offload, when a single route is deleted, it is
only of interest if it is the first route in the node or if it is
sibling to such a route.
In the first case, distinguish between several possibilities:
1. Route is the last route in the node. Emit a delete notification
2. Route is followed by a non-multipath route. Emit a replace
notification for the non-multipath route.
3. Route is followed by a multipath route. Emit a replace notification
for the multipath route.
In the second case, only emit a delete notification to ensure the route
is no longer used as a valid nexthop.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When a new listener is registered to the FIB notification chain it
receives a dump of all the available routes in the system. Instead, make
sure to only replay the IPv6 routes that are actually used in the data
path and are of any interest to the new listener.
This is done by iterating over all the routing tables in the given
namespace, but from each traversed node only the first route ('leaf') is
notified. Multipath routes are notified in a single notification instead
of one for each nexthop.
Add fib6_rt_dump_tmp() to do that. Later on in the patch set it will be
renamed to fib6_rt_dump() instead of the existing one.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Similar to the corresponding IPv4 patch, only notify the new route if it
is replacing the currently offloaded one. Meaning, the one pointed to by
'fn->leaf'.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
fib6_add_rt2node() takes care of adding a single route ('struct
fib6_info') to a FIB node. The route in question should only be notified
in case it is added as the first route in the node (lowest metric) or if
it is added as a sibling route to the first route in the node.
The first criterion can be tested by checking if the route is pointed to
by 'fn->leaf'. The second criterion can be tested by checking the new
'notify_sibling_rt' variable that is set when the route is added as a
sibling to the first route in the node.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use a per namespace counter, increment it on successful creation
of any route using the source address, decrement it on deletion
of such routes.
This allows us to check easily if the routing decision in the
current namespace depends on the packet source. Will be used
by the next patch.
Suggested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since errors are propagated all the way up to the caller, propagate
possible extack of the caller all the way down to the notifier block
callback.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Unlike events for registered notifier, during the registration, the
errors that happened for the block being registered are not propagated
up to the caller. Make sure the error is propagated for FIB rules and
entries.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently all users of FIB notifier only cares about events in init_net.
Later in this patchset, users get interested in other namespaces too.
However, for every registered block user is interested only about one
namespace. Make the FIB notifier registration per-netns and avoid
unnecessary calls of notifier block for other namespaces.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Yi Ren reported an issue discovered by syzkaller, and bisected
to the cited commit.
Many thanks to Yi, this trivial patch does not reflect the patient
work that has been done.
Fixes: d64a1f574a ("ipv6: honor RT6_LOOKUP_F_DST_NOREF in rule lookup logic")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Wei Wang <weiwan@google.com>
Bisected-and-reported-by: Yi Ren <c4tren@gmail.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
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 08e814c9e8: 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>
