Commit Graph

124 Commits

Author SHA1 Message Date
Li Zetao
649c3c9b8e net: nexthop: delete redundant judgment statements
The initial value of err is -ENOBUFS, and err is guaranteed to be
less than 0 before all goto errout. Therefore, on the error path
of errout, there is no need to repeatedly judge that err is less than 0,
and delete redundant judgments to make the code more concise.

Signed-off-by: Li Zetao <lizetao1@huawei.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-08-23 14:27:45 +01:00
Petr Machata
b72a6a7ab9 net: nexthop: Increase weight to u16
In CLOS networks, as link failures occur at various points in the network,
ECMP weights of the involved nodes are adjusted to compensate. With high
fan-out of the involved nodes, and overall high number of nodes,
a (non-)ECMP weight ratio that we would like to configure does not fit into
8 bits. Instead of, say, 255:254, we might like to configure something like
1000:999. For these deployments, the 8-bit weight may not be enough.

To that end, in this patch increase the next hop weight from u8 to u16.

Increasing the width of an integral type can be tricky, because while the
code still compiles, the types may not check out anymore, and numerical
errors come up. To prevent this, the conversion was done in two steps.
First the type was changed from u8 to a single-member structure, which
invalidated all uses of the field. This allowed going through them one by
one and audit for type correctness. Then the structure was replaced with a
vanilla u16 again. This should ensure that no place was missed.

The UAPI for configuring nexthop group members is that an attribute
NHA_GROUP carries an array of struct nexthop_grp entries:

	struct nexthop_grp {
		__u32	id;	  /* nexthop id - must exist */
		__u8	weight;   /* weight of this nexthop */
		__u8	resvd1;
		__u16	resvd2;
	};

The field resvd1 is currently validated and required to be zero. We can
lift this requirement and carry high-order bits of the weight in the
reserved field:

	struct nexthop_grp {
		__u32	id;	  /* nexthop id - must exist */
		__u8	weight;   /* weight of this nexthop */
		__u8	weight_high;
		__u16	resvd2;
	};

Keeping the fields split this way was chosen in case an existing userspace
makes assumptions about the width of the weight field, and to sidestep any
endianness issues.

The weight field is currently encoded as the weight value minus one,
because weight of 0 is invalid. This same trick is impossible for the new
weight_high field, because zero must mean actual zero. With this in place:

- Old userspace is guaranteed to carry weight_high of 0, therefore
  configuring 8-bit weights as appropriate. When dumping nexthops with
  16-bit weight, it would only show the lower 8 bits. But configuring such
  nexthops implies existence of userspace aware of the extension in the
  first place.

- New userspace talking to an old kernel will work as long as it only
  attempts to configure 8-bit weights, where the high-order bits are zero.
  Old kernel will bounce attempts at configuring >8-bit weights.

Renaming reserved fields as they are allocated for some purpose is commonly
done in Linux. Whoever touches a reserved field is doing so at their own
risk. nexthop_grp::resvd1 in particular is currently used by at least
strace, however they carry an own copy of UAPI headers, and the conversion
should be trivial. A helper is provided for decoding the weight out of the
two fields. Forcing a conversion seems preferable to bending backwards and
introducing anonymous unions or whatever.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Link: https://patch.msgid.link/483e2fcf4beb0d9135d62e7d27b46fa2685479d4.1723036486.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-12 17:50:34 -07:00
Petr Machata
75bab45e6b net: nexthop: Add flag to assert that NHGRP reserved fields are zero
There are many unpatched kernel versions out there that do not initialize
the reserved fields of struct nexthop_grp. The issue with that is that if
those fields were to be used for some end (i.e. stop being reserved), old
kernels would still keep sending random data through the field, and a new
userspace could not rely on the value.

In this patch, use the existing NHA_OP_FLAGS, which is currently inbound
only, to carry flags back to the userspace. Add a flag to indicate that the
reserved fields in struct nexthop_grp are zeroed before dumping. This is
reliant on the actual fix from commit 6d745cd0e9 ("net: nexthop:
Initialize all fields in dumped nexthops").

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/21037748d4f9d8ff486151f4c09083bcf12d5df8.1723036486.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-08-12 17:50:34 -07:00
Petr Machata
6d745cd0e9 net: nexthop: Initialize all fields in dumped nexthops
struct nexthop_grp contains two reserved fields that are not initialized by
nla_put_nh_group(), and carry garbage. This can be observed e.g. with
strace (edited for clarity):

    # ip nexthop add id 1 dev lo
    # ip nexthop add id 101 group 1
    # strace -e recvmsg ip nexthop get id 101
    ...
    recvmsg(... [{nla_len=12, nla_type=NHA_GROUP},
                 [{id=1, weight=0, resvd1=0x69, resvd2=0x67}]] ...) = 52

The fields are reserved and therefore not currently used. But as they are, they
leak kernel memory, and the fact they are not just zero complicates repurposing
of the fields for new ends. Initialize the full structure.

Fixes: 430a049190 ("nexthop: Add support for nexthop groups")
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-07-24 15:13:43 +01:00
Dan Carpenter
9145e2249e nexthop: fix uninitialized variable in nla_put_nh_group_stats()
The "*hw_stats_used" value needs to be set on the success paths to prevent
an uninitialized variable bug in the caller, nla_put_nh_group_stats().

Fixes: 5072ae00ae ("net: nexthop: Expose nexthop group HW stats to user space")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/f08ac289-d57f-4a1a-830f-cf9a0563cb9c@moroto.mountain
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-22 18:03:29 -07:00
Ido Schimmel
e006858f1a nexthop: Fix splat with CONFIG_DEBUG_PREEMPT=y
Locally generated packets can increment the new nexthop statistics from
process context, resulting in the following splat [1] due to preemption
being enabled. Fix by using get_cpu_ptr() / put_cpu_ptr() which will
which take care of disabling / enabling preemption.

BUG: using smp_processor_id() in preemptible [00000000] code: ping/949
caller is nexthop_select_path+0xcf8/0x1e30
CPU: 12 PID: 949 Comm: ping Not tainted 6.8.0-rc7-custom-gcb450f605fae #11
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc38 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xbd/0xe0
 check_preemption_disabled+0xce/0xe0
 nexthop_select_path+0xcf8/0x1e30
 fib_select_multipath+0x865/0x18b0
 fib_select_path+0x311/0x1160
 ip_route_output_key_hash_rcu+0xe54/0x2720
 ip_route_output_key_hash+0x193/0x380
 ip_route_output_flow+0x25/0x130
 raw_sendmsg+0xbab/0x34a0
 inet_sendmsg+0xa2/0xe0
 __sys_sendto+0x2ad/0x430
 __x64_sys_sendto+0xe5/0x1c0
 do_syscall_64+0xc5/0x1d0
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
[...]

Fixes: f4676ea74b ("net: nexthop: Add nexthop group entry stats")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240311162307.545385-5-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-11 20:35:20 -07:00
Ido Schimmel
d8a21070b6 nexthop: Fix out-of-bounds access during attribute validation
Passing a maximum attribute type to nlmsg_parse() that is larger than
the size of the passed policy will result in an out-of-bounds access [1]
when the attribute type is used as an index into the policy array.

Fix by setting the maximum attribute type according to the policy size,
as is already done for RTM_NEWNEXTHOP messages. Add a test case that
triggers the bug.

No regressions in fib nexthops tests:

 # ./fib_nexthops.sh
 [...]
 Tests passed: 236
 Tests failed:   0

[1]
BUG: KASAN: global-out-of-bounds in __nla_validate_parse+0x1e53/0x2940
Read of size 1 at addr ffffffff99ab4d20 by task ip/610

CPU: 3 PID: 610 Comm: ip Not tainted 6.8.0-rc7-custom-gd435d6e3e161 #9
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-1.fc38 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x8f/0xe0
 print_report+0xcf/0x670
 kasan_report+0xd8/0x110
 __nla_validate_parse+0x1e53/0x2940
 __nla_parse+0x40/0x50
 rtm_del_nexthop+0x1bd/0x400
 rtnetlink_rcv_msg+0x3cc/0xf20
 netlink_rcv_skb+0x170/0x440
 netlink_unicast+0x540/0x820
 netlink_sendmsg+0x8d3/0xdb0
 ____sys_sendmsg+0x31f/0xa60
 ___sys_sendmsg+0x13a/0x1e0
 __sys_sendmsg+0x11c/0x1f0
 do_syscall_64+0xc5/0x1d0
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
[...]

The buggy address belongs to the variable:
 rtm_nh_policy_del+0x20/0x40

Fixes: 2118f9390d ("net: nexthop: Adjust netlink policy parsing for a new attribute")
Reported-by: Eric Dumazet <edumazet@google.com>
Closes: https://lore.kernel.org/netdev/CANn89i+UNcG0PJMW5X7gOMunF38ryMh=L1aeZUKH3kL4UdUqag@mail.gmail.com/
Reported-by: syzbot+65bb09a7208ce3d4a633@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/00000000000088981b06133bc07b@google.com/
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240311162307.545385-4-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-11 20:35:20 -07:00
Ido Schimmel
262a68aa46 nexthop: Only parse NHA_OP_FLAGS for dump messages that require it
The attribute is parsed in __nh_valid_dump_req() which is called by the
dump handlers of RTM_GETNEXTHOP and RTM_GETNEXTHOPBUCKET although it is
only used by the former and rejected by the policy of the latter.

Move the parsing to nh_valid_dump_req() which is only called by the dump
handler of RTM_GETNEXTHOP.

This is a preparation for a subsequent patch.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240311162307.545385-3-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-11 20:35:20 -07:00
Ido Schimmel
dc5e0141ff nexthop: Only parse NHA_OP_FLAGS for get messages that require it
The attribute is parsed into 'op_flags' in nh_valid_get_del_req() which
is called from the handlers of three message types: RTM_DELNEXTHOP,
RTM_GETNEXTHOPBUCKET and RTM_GETNEXTHOP. The attribute is only used by
the latter and rejected by the policies of the other two.

Pass 'op_flags' as NULL from the handlers of the other two and only
parse the attribute when the argument is not NULL.

This is a preparation for a subsequent patch.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240311162307.545385-2-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-11 20:35:20 -07:00
Petr Machata
e99eb57e9b net: nexthop: Have all NH notifiers carry NH ID
When sending the notifications to collect NH statistics for resilient
groups, the driver will need to know the nexthop IDs in individual buckets
to look up the right counter. To that end, move the nexthop ID from struct
nh_notifier_grp_entry_info to nh_notifier_single_info.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/8f964cd50b1a56d3606ce7ab4c50354ae019c43b.1709901020.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-11 14:14:07 -07:00
Petr Machata
2d32c49386 net: nexthop: Initialize NH group ID in resilient NH group notifiers
The NEXTHOP_EVENT_RES_TABLE_PRE_REPLACE notifier currently keeps the group
ID unset. That makes it impossible to look up the group for which the
notifier is intended. This is not an issue at the moment, because the only
client is netdevsim, and that just so that it veto replacements, which is a
static property not tied to a particular group. But for any practical use,
the ID is necessary. Set it.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/025fef095dcfb408042568bb5439da014d47239e.1709901020.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-11 14:14:06 -07:00
Ido Schimmel
5d9b7cb383 nexthop: Simplify dump error handling
The only error that can happen during a nexthop dump is insufficient
space in the skb caring the netlink messages (EMSGSIZE). If this happens
and some messages were already filled in, the nexthop code returns the
skb length to signal the netlink core that more objects need to be
dumped.

After commit b5a899154a ("netlink: handle EMSGSIZE errors in the
core") there is no need to handle this error in the nexthop code as it
is now handled in the core.

Simplify the code and simply return the error to the core.

No regressions in nexthop tests:

 # ./fib_nexthops.sh
 Tests passed: 234
 Tests failed:   0

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240307154727.3555462-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-08 11:39:12 -08:00
Ido Schimmel
5072ae00ae net: nexthop: Expose nexthop group HW stats to user space
Add netlink support for reading NH group hardware stats.

Stats collection is done through a new notifier,
NEXTHOP_EVENT_HW_STATS_REPORT_DELTA. Drivers that implement HW counters for
a given NH group are thereby asked to collect the stats and report back to
core by calling nh_grp_hw_stats_report_delta(). This is similar to what
netdevice L3 stats do.

Besides exposing number of packets that passed in the HW datapath, also
include information on whether any driver actually realizes the counters.
The core can tell based on whether it got any _report_delta() reports from
the drivers. This allows enabling the statistics at the group at any time,
with drivers opting into supporting them. This is also in line with what
netdevice L3 stats are doing.

So as not to waste time and space, tie the collection and reporting of HW
stats with a new op flag, NHA_OP_FLAG_DUMP_HW_STATS.

Co-developed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Kees Cook <keescook@chromium.org> # For the __counted_by bits
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-03-08 10:35:47 +00:00
Ido Schimmel
746c19a52e net: nexthop: Add ability to enable / disable hardware statistics
Add netlink support for enabling collection of HW statistics on nexthop
groups.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-03-08 10:35:47 +00:00
Ido Schimmel
5877786fcf net: nexthop: Add hardware statistics notifications
Add hw_stats field to several notifier structures to communicate to the
drivers that HW statistics should be configured for nexthops within a given
group.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-03-08 10:35:47 +00:00
Ido Schimmel
95fedd7685 net: nexthop: Expose nexthop group stats to user space
Add netlink support for reading NH group stats.

This data is only for statistics of the traffic in the SW datapath. HW
nexthop group statistics will be added in the following patches.

Emission of the stats is keyed to a new op_stats flag to avoid cluttering
the netlink message with stats if the user doesn't need them:
NHA_OP_FLAG_DUMP_STATS.

Co-developed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-03-08 10:35:47 +00:00
Ido Schimmel
f4676ea74b net: nexthop: Add nexthop group entry stats
Add nexthop group entry stats to count the number of packets forwarded
via each nexthop in the group. The stats will be exposed to user space
for better data path observability in the next patch.

The per-CPU stats pointer is placed at the beginning of 'struct
nh_grp_entry', so that all the fields accessed for the data path reside
on the same cache line:

struct nh_grp_entry {
        struct nexthop *           nh;                   /*     0     8 */
        struct nh_grp_entry_stats * stats;               /*     8     8 */
        u8                         weight;               /*    16     1 */

        /* XXX 7 bytes hole, try to pack */

        union {
                struct {
                        atomic_t   upper_bound;          /*    24     4 */
                } hthr;                                  /*    24     4 */
                struct {
                        struct list_head uw_nh_entry;    /*    24    16 */
                        u16        count_buckets;        /*    40     2 */
                        u16        wants_buckets;        /*    42     2 */
                } res;                                   /*    24    24 */
        };                                               /*    24    24 */
        struct list_head           nh_list;              /*    48    16 */
        /* --- cacheline 1 boundary (64 bytes) --- */
        struct nexthop *           nh_parent;            /*    64     8 */

        /* size: 72, cachelines: 2, members: 6 */
        /* sum members: 65, holes: 1, sum holes: 7 */
        /* last cacheline: 8 bytes */
};

Co-developed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-03-08 10:35:46 +00:00
Petr Machata
a207eab103 net: nexthop: Add NHA_OP_FLAGS
In order to add per-nexthop statistics, but still not increase netlink
message size for consumers that do not care about them, there needs to be a
toggle through which the user indicates their desire to get the statistics.
To that end, add a new attribute, NHA_OP_FLAGS. The idea is to be able to
use the attribute for carrying of arbitrary operation-specific flags, i.e.
not make it specific for get / dump.

Add the new attribute to get and dump policies, but do not actually allow
any flags yet -- those will come later as the flags themselves are defined.
Add the necessary parsing code.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-03-08 10:35:46 +00:00
Petr Machata
2118f9390d net: nexthop: Adjust netlink policy parsing for a new attribute
A following patch will introduce a new attribute, op-specific flags to
adjust the behavior of an operation. Different operations will recognize
different flags.

- To make the differentiation possible, stop sharing the policies for get
  and del operations.

- To allow querying for presence of the attribute, have all the attribute
  arrays sized to NHA_MAX, regardless of what is permitted by policy, and
  pass the corresponding value to nlmsg_parse() as well.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-03-08 10:35:46 +00:00
Eric Dumazet
70f16ea2e4 ipv4: add __unregister_nexthop_notifier()
unregister_nexthop_notifier() assumes the caller does not hold rtnl.

We need in the following patch to use it from a context
already holding rtnl.

Add __unregister_nexthop_notifier().

unregister_nexthop_notifier() becomes a wrapper.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Antoine Tenart <atenart@kernel.org>
Link: https://lore.kernel.org/r/20240206144313.2050392-9-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-02-07 18:55:11 -08:00
Eric Dumazet
a7ec2512ad nexthop: convert nexthop_net_exit_batch to exit_batch_rtnl method
exit_batch_rtnl() is called while RTNL is held.

This saves one rtnl_lock()/rtnl_unlock() pair.

We also need to create nexthop_net_exit()
to make sure net->nexthop.devhash is not freed too soon,
otherwise we will not be able to unregister netdev
from exit_batch_rtnl() methods.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Antoine Tenart <atenart@kernel.org>
Link: https://lore.kernel.org/r/20240206144313.2050392-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-02-07 18:55:11 -08:00
Ido Schimmel
db1428f66a nexthop: Do not increment dump sentinel at the end of the dump
The nexthop and nexthop bucket dump callbacks previously returned a
positive return code even when the dump was complete, prompting the core
netlink code to invoke the callback again, until returning zero.

Zero was only returned by these callbacks when no information was filled
in the provided skb, which was achieved by incrementing the dump
sentinel at the end of the dump beyond the ID of the last nexthop.

This is no longer necessary as when the dump is complete these callbacks
return zero.

Remove the unnecessary increment.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20230813164856.2379822-3-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-15 18:54:53 -07:00
Ido Schimmel
23ab9324fd nexthop: Simplify nexthop bucket dump
Before commit f10d3d9df4 ("nexthop: Make nexthop bucket dump more
efficient"), rtm_dump_nexthop_bucket_nh() returned a non-zero return
code for each resilient nexthop group whose buckets it dumped,
regardless if it encountered an error or not.

This meant that the sentinel ('dd->ctx->nh.idx') used by the function
that walked the different nexthops could not be used as a sentinel for
the bucket dump, as otherwise buckets from the same group would be
dumped over and over again.

This was dealt with by adding another sentinel ('dd->ctx->done_nh_idx')
that was incremented by rtm_dump_nexthop_bucket_nh() after successfully
dumping all the buckets from a given group.

After the previously mentioned commit this sentinel is no longer
necessary since the function no longer returns a non-zero return code
when successfully dumping all the buckets from a given group.

Remove this sentinel and simplify the code.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20230813164856.2379822-2-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-15 18:54:52 -07:00
Jakub Kicinski
4d016ae42e Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

No conflicts.

Adjacent changes:

drivers/net/ethernet/intel/igc/igc_main.c
  06b412589e ("igc: Add lock to safeguard global Qbv variables")
  d3750076d4 ("igc: Add TransmissionOverrun counter")

drivers/net/ethernet/microsoft/mana/mana_en.c
  a7dfeda6fd ("net: mana: Fix MANA VF unload when hardware is unresponsive")
  a9ca9f9cef ("page_pool: split types and declarations from page_pool.h")
  92272ec410 ("eth: add missing xdp.h includes in drivers")

net/mptcp/protocol.h
  511b90e392 ("mptcp: fix disconnect vs accept race")
  b8dc6d6ce9 ("mptcp: fix rcv buffer auto-tuning")

tools/testing/selftests/net/mptcp/mptcp_join.sh
  c8c101ae39 ("selftests: mptcp: join: fix 'implicit EP' test")
  03668c65d1 ("selftests: mptcp: join: rework detailed report")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-10 14:10:53 -07:00
Ido Schimmel
8743aeff5b nexthop: Fix infinite nexthop bucket dump when using maximum nexthop ID
A netlink dump callback can return a positive number to signal that more
information needs to be dumped or zero to signal that the dump is
complete. In the second case, the core netlink code will append the
NLMSG_DONE message to the skb in order to indicate to user space that
the dump is complete.

The nexthop bucket dump callback always returns a positive number if
nexthop buckets were filled in the provided skb, even if the dump is
complete. This means that a dump will span at least two recvmsg() calls
as long as nexthop buckets are present. In the last recvmsg() call the
dump callback will not fill in any nexthop buckets because the previous
call indicated that the dump should restart from the last dumped nexthop
ID plus one.

 # ip link add name dummy1 up type dummy
 # ip nexthop add id 1 dev dummy1
 # ip nexthop add id 10 group 1 type resilient buckets 2
 # strace -e sendto,recvmsg -s 5 ip nexthop bucket
 sendto(3, [[{nlmsg_len=24, nlmsg_type=RTM_GETNEXTHOPBUCKET, nlmsg_flags=NLM_F_REQUEST|NLM_F_DUMP, nlmsg_seq=1691396980, nlmsg_pid=0}, {family=AF_UNSPEC, data="\x00\x00\x00\x00\x00"...}], {nlmsg_len=0, nlmsg_type=0 /* NLMSG_??? */, nlmsg_flags=0, nlmsg_seq=0, nlmsg_pid=0}], 152, 0, NULL, 0) = 152
 recvmsg(3, {msg_name={sa_family=AF_NETLINK, nl_pid=0, nl_groups=00000000}, msg_namelen=12, msg_iov=[{iov_base=NULL, iov_len=0}], msg_iovlen=1, msg_controllen=0, msg_flags=MSG_TRUNC}, MSG_PEEK|MSG_TRUNC) = 128
 recvmsg(3, {msg_name={sa_family=AF_NETLINK, nl_pid=0, nl_groups=00000000}, msg_namelen=12, msg_iov=[{iov_base=[[{nlmsg_len=64, nlmsg_type=RTM_NEWNEXTHOPBUCKET, nlmsg_flags=NLM_F_MULTI, nlmsg_seq=1691396980, nlmsg_pid=347}, {family=AF_UNSPEC, data="\x00\x00\x00\x00\x00"...}], [{nlmsg_len=64, nlmsg_type=RTM_NEWNEXTHOPBUCKET, nlmsg_flags=NLM_F_MULTI, nlmsg_seq=1691396980, nlmsg_pid=347}, {family=AF_UNSPEC, data="\x00\x00\x00\x00\x00"...}]], iov_len=32768}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 128
 id 10 index 0 idle_time 6.66 nhid 1
 id 10 index 1 idle_time 6.66 nhid 1
 recvmsg(3, {msg_name={sa_family=AF_NETLINK, nl_pid=0, nl_groups=00000000}, msg_namelen=12, msg_iov=[{iov_base=NULL, iov_len=0}], msg_iovlen=1, msg_controllen=0, msg_flags=MSG_TRUNC}, MSG_PEEK|MSG_TRUNC) = 20
 recvmsg(3, {msg_name={sa_family=AF_NETLINK, nl_pid=0, nl_groups=00000000}, msg_namelen=12, msg_iov=[{iov_base=[{nlmsg_len=20, nlmsg_type=NLMSG_DONE, nlmsg_flags=NLM_F_MULTI, nlmsg_seq=1691396980, nlmsg_pid=347}, 0], iov_len=32768}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 20
 +++ exited with 0 +++

This behavior is both inefficient and buggy. If the last nexthop to be
dumped had the maximum ID of 0xffffffff, then the dump will restart from
0 (0xffffffff + 1) and never end:

 # ip link add name dummy1 up type dummy
 # ip nexthop add id 1 dev dummy1
 # ip nexthop add id $((2**32-1)) group 1 type resilient buckets 2
 # ip nexthop bucket
 id 4294967295 index 0 idle_time 5.55 nhid 1
 id 4294967295 index 1 idle_time 5.55 nhid 1
 id 4294967295 index 0 idle_time 5.55 nhid 1
 id 4294967295 index 1 idle_time 5.55 nhid 1
 [...]

Fix by adjusting the dump callback to return zero when the dump is
complete. After the fix only one recvmsg() call is made and the
NLMSG_DONE message is appended to the RTM_NEWNEXTHOPBUCKET responses:

 # ip link add name dummy1 up type dummy
 # ip nexthop add id 1 dev dummy1
 # ip nexthop add id $((2**32-1)) group 1 type resilient buckets 2
 # strace -e sendto,recvmsg -s 5 ip nexthop bucket
 sendto(3, [[{nlmsg_len=24, nlmsg_type=RTM_GETNEXTHOPBUCKET, nlmsg_flags=NLM_F_REQUEST|NLM_F_DUMP, nlmsg_seq=1691396737, nlmsg_pid=0}, {family=AF_UNSPEC, data="\x00\x00\x00\x00\x00"...}], {nlmsg_len=0, nlmsg_type=0 /* NLMSG_??? */, nlmsg_flags=0, nlmsg_seq=0, nlmsg_pid=0}], 152, 0, NULL, 0) = 152
 recvmsg(3, {msg_name={sa_family=AF_NETLINK, nl_pid=0, nl_groups=00000000}, msg_namelen=12, msg_iov=[{iov_base=NULL, iov_len=0}], msg_iovlen=1, msg_controllen=0, msg_flags=MSG_TRUNC}, MSG_PEEK|MSG_TRUNC) = 148
 recvmsg(3, {msg_name={sa_family=AF_NETLINK, nl_pid=0, nl_groups=00000000}, msg_namelen=12, msg_iov=[{iov_base=[[{nlmsg_len=64, nlmsg_type=RTM_NEWNEXTHOPBUCKET, nlmsg_flags=NLM_F_MULTI, nlmsg_seq=1691396737, nlmsg_pid=350}, {family=AF_UNSPEC, data="\x00\x00\x00\x00\x00"...}], [{nlmsg_len=64, nlmsg_type=RTM_NEWNEXTHOPBUCKET, nlmsg_flags=NLM_F_MULTI, nlmsg_seq=1691396737, nlmsg_pid=350}, {family=AF_UNSPEC, data="\x00\x00\x00\x00\x00"...}], [{nlmsg_len=20, nlmsg_type=NLMSG_DONE, nlmsg_flags=NLM_F_MULTI, nlmsg_seq=1691396737, nlmsg_pid=350}, 0]], iov_len=32768}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 148
 id 4294967295 index 0 idle_time 6.61 nhid 1
 id 4294967295 index 1 idle_time 6.61 nhid 1
 +++ exited with 0 +++

Note that if the NLMSG_DONE message cannot be appended because of size
limitations, then another recvmsg() will be needed, but the core netlink
code will not invoke the dump callback and simply reply with a
NLMSG_DONE message since it knows that the callback previously returned
zero.

Add a test that fails before the fix:

 # ./fib_nexthops.sh -t basic_res
 [...]
 TEST: Maximum nexthop ID dump                                       [FAIL]
 [...]

And passes after it:

 # ./fib_nexthops.sh -t basic_res
 [...]
 TEST: Maximum nexthop ID dump                                       [ OK ]
 [...]

Fixes: 8a1bbabb03 ("nexthop: Add netlink handlers for bucket dump")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20230808075233.3337922-4-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-09 13:45:12 -07:00
Ido Schimmel
f10d3d9df4 nexthop: Make nexthop bucket dump more efficient
rtm_dump_nexthop_bucket_nh() is used to dump nexthop buckets belonging
to a specific resilient nexthop group. The function returns a positive
return code (the skb length) upon both success and failure.

The above behavior is problematic. When a complete nexthop bucket dump
is requested, the function that walks the different nexthops treats the
non-zero return code as an error. This causes buckets belonging to
different resilient nexthop groups to be dumped using different buffers
even if they can all fit in the same buffer:

 # ip link add name dummy1 up type dummy
 # ip nexthop add id 1 dev dummy1
 # ip nexthop add id 10 group 1 type resilient buckets 1
 # ip nexthop add id 20 group 1 type resilient buckets 1
 # strace -e recvmsg -s 0 ip nexthop bucket
 [...]
 recvmsg(3, {msg_name={sa_family=AF_NETLINK, nl_pid=0, nl_groups=00000000}, msg_namelen=12, msg_iov=[...], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 64
 id 10 index 0 idle_time 10.27 nhid 1
 [...]
 recvmsg(3, {msg_name={sa_family=AF_NETLINK, nl_pid=0, nl_groups=00000000}, msg_namelen=12, msg_iov=[...], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 64
 id 20 index 0 idle_time 6.44 nhid 1
 [...]

Fix by only returning a non-zero return code when an error occurred and
restarting the dump from the bucket index we failed to fill in. This
allows buckets belonging to different resilient nexthop groups to be
dumped using the same buffer:

 # ip link add name dummy1 up type dummy
 # ip nexthop add id 1 dev dummy1
 # ip nexthop add id 10 group 1 type resilient buckets 1
 # ip nexthop add id 20 group 1 type resilient buckets 1
 # strace -e recvmsg -s 0 ip nexthop bucket
 [...]
 recvmsg(3, {msg_name={sa_family=AF_NETLINK, nl_pid=0, nl_groups=00000000}, msg_namelen=12, msg_iov=[...], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 128
 id 10 index 0 idle_time 30.21 nhid 1
 id 20 index 0 idle_time 26.7 nhid 1
 [...]

While this change is more of a performance improvement change than an
actual bug fix, it is a prerequisite for a subsequent patch that does
fix a bug.

Fixes: 8a1bbabb03 ("nexthop: Add netlink handlers for bucket dump")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20230808075233.3337922-3-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-09 13:45:04 -07:00
Ido Schimmel
913f60cacd nexthop: Fix infinite nexthop dump when using maximum nexthop ID
A netlink dump callback can return a positive number to signal that more
information needs to be dumped or zero to signal that the dump is
complete. In the second case, the core netlink code will append the
NLMSG_DONE message to the skb in order to indicate to user space that
the dump is complete.

The nexthop dump callback always returns a positive number if nexthops
were filled in the provided skb, even if the dump is complete. This
means that a dump will span at least two recvmsg() calls as long as
nexthops are present. In the last recvmsg() call the dump callback will
not fill in any nexthops because the previous call indicated that the
dump should restart from the last dumped nexthop ID plus one.

 # ip nexthop add id 1 blackhole
 # strace -e sendto,recvmsg -s 5 ip nexthop
 sendto(3, [[{nlmsg_len=24, nlmsg_type=RTM_GETNEXTHOP, nlmsg_flags=NLM_F_REQUEST|NLM_F_DUMP, nlmsg_seq=1691394315, nlmsg_pid=0}, {nh_family=AF_UNSPEC, nh_scope=RT_SCOPE_UNIVERSE, nh_protocol=RTPROT_UNSPEC, nh_flags=0}], {nlmsg_len=0, nlmsg_type=0 /* NLMSG_??? */, nlmsg_flags=0, nlmsg_seq=0, nlmsg_pid=0}], 152, 0, NULL, 0) = 152
 recvmsg(3, {msg_name={sa_family=AF_NETLINK, nl_pid=0, nl_groups=00000000}, msg_namelen=12, msg_iov=[{iov_base=NULL, iov_len=0}], msg_iovlen=1, msg_controllen=0, msg_flags=MSG_TRUNC}, MSG_PEEK|MSG_TRUNC) = 36
 recvmsg(3, {msg_name={sa_family=AF_NETLINK, nl_pid=0, nl_groups=00000000}, msg_namelen=12, msg_iov=[{iov_base=[{nlmsg_len=36, nlmsg_type=RTM_NEWNEXTHOP, nlmsg_flags=NLM_F_MULTI, nlmsg_seq=1691394315, nlmsg_pid=343}, {nh_family=AF_INET, nh_scope=RT_SCOPE_UNIVERSE, nh_protocol=RTPROT_UNSPEC, nh_flags=0}, [[{nla_len=8, nla_type=NHA_ID}, 1], {nla_len=4, nla_type=NHA_BLACKHOLE}]], iov_len=32768}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 36
 id 1 blackhole
 recvmsg(3, {msg_name={sa_family=AF_NETLINK, nl_pid=0, nl_groups=00000000}, msg_namelen=12, msg_iov=[{iov_base=NULL, iov_len=0}], msg_iovlen=1, msg_controllen=0, msg_flags=MSG_TRUNC}, MSG_PEEK|MSG_TRUNC) = 20
 recvmsg(3, {msg_name={sa_family=AF_NETLINK, nl_pid=0, nl_groups=00000000}, msg_namelen=12, msg_iov=[{iov_base=[{nlmsg_len=20, nlmsg_type=NLMSG_DONE, nlmsg_flags=NLM_F_MULTI, nlmsg_seq=1691394315, nlmsg_pid=343}, 0], iov_len=32768}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 20
 +++ exited with 0 +++

This behavior is both inefficient and buggy. If the last nexthop to be
dumped had the maximum ID of 0xffffffff, then the dump will restart from
0 (0xffffffff + 1) and never end:

 # ip nexthop add id $((2**32-1)) blackhole
 # ip nexthop
 id 4294967295 blackhole
 id 4294967295 blackhole
 [...]

Fix by adjusting the dump callback to return zero when the dump is
complete. After the fix only one recvmsg() call is made and the
NLMSG_DONE message is appended to the RTM_NEWNEXTHOP response:

 # ip nexthop add id $((2**32-1)) blackhole
 # strace -e sendto,recvmsg -s 5 ip nexthop
 sendto(3, [[{nlmsg_len=24, nlmsg_type=RTM_GETNEXTHOP, nlmsg_flags=NLM_F_REQUEST|NLM_F_DUMP, nlmsg_seq=1691394080, nlmsg_pid=0}, {nh_family=AF_UNSPEC, nh_scope=RT_SCOPE_UNIVERSE, nh_protocol=RTPROT_UNSPEC, nh_flags=0}], {nlmsg_len=0, nlmsg_type=0 /* NLMSG_??? */, nlmsg_flags=0, nlmsg_seq=0, nlmsg_pid=0}], 152, 0, NULL, 0) = 152
 recvmsg(3, {msg_name={sa_family=AF_NETLINK, nl_pid=0, nl_groups=00000000}, msg_namelen=12, msg_iov=[{iov_base=NULL, iov_len=0}], msg_iovlen=1, msg_controllen=0, msg_flags=MSG_TRUNC}, MSG_PEEK|MSG_TRUNC) = 56
 recvmsg(3, {msg_name={sa_family=AF_NETLINK, nl_pid=0, nl_groups=00000000}, msg_namelen=12, msg_iov=[{iov_base=[[{nlmsg_len=36, nlmsg_type=RTM_NEWNEXTHOP, nlmsg_flags=NLM_F_MULTI, nlmsg_seq=1691394080, nlmsg_pid=342}, {nh_family=AF_INET, nh_scope=RT_SCOPE_UNIVERSE, nh_protocol=RTPROT_UNSPEC, nh_flags=0}, [[{nla_len=8, nla_type=NHA_ID}, 4294967295], {nla_len=4, nla_type=NHA_BLACKHOLE}]], [{nlmsg_len=20, nlmsg_type=NLMSG_DONE, nlmsg_flags=NLM_F_MULTI, nlmsg_seq=1691394080, nlmsg_pid=342}, 0]], iov_len=32768}], msg_iovlen=1, msg_controllen=0, msg_flags=0}, 0) = 56
 id 4294967295 blackhole
 +++ exited with 0 +++

Note that if the NLMSG_DONE message cannot be appended because of size
limitations, then another recvmsg() will be needed, but the core netlink
code will not invoke the dump callback and simply reply with a
NLMSG_DONE message since it knows that the callback previously returned
zero.

Add a test that fails before the fix:

 # ./fib_nexthops.sh -t basic
 [...]
 TEST: Maximum nexthop ID dump                                       [FAIL]
 [...]

And passes after it:

 # ./fib_nexthops.sh -t basic
 [...]
 TEST: Maximum nexthop ID dump                                       [ OK ]
 [...]

Fixes: ab84be7e54 ("net: Initial nexthop code")
Reported-by: Petr Machata <petrm@nvidia.com>
Closes: https://lore.kernel.org/netdev/87sf91enuf.fsf@nvidia.com/
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20230808075233.3337922-2-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-09 13:44:36 -07:00
Benjamin Poirier
75f5f04c7b nexthop: Do not return invalid nexthop object during multipath selection
With legacy nexthops, when net.ipv4.fib_multipath_use_neigh is set,
fib_select_multipath() will never set res->nhc to a nexthop that is not
good (as per fib_good_nh()). OTOH, with nexthop objects,
nexthop_select_path_hthr() may return a nexthop that failed the
nexthop_is_good_nh() test even if there was one that passed. Refactor
nexthop_select_path_hthr() to follow a selection logic more similar to
fib_select_multipath().

The issue can be demonstrated with the following sequence of commands. The
first block shows that things work as expected with legacy nexthops. The
last sequence of `ip rou get` in the second block shows the problem case -
some routes still use the .2 nexthop.

sysctl net.ipv4.fib_multipath_use_neigh=1
ip link add dummy1 up type dummy
ip rou add 198.51.100.0/24 nexthop via 192.0.2.1 dev dummy1 onlink nexthop via 192.0.2.2 dev dummy1 onlink
for i in {10..19}; do ip -o rou get 198.51.100.$i; done
ip neigh add 192.0.2.1 dev dummy1 nud failed
echo ".1 failed:"  # results should not use .1
for i in {10..19}; do ip -o rou get 198.51.100.$i; done
ip neigh del 192.0.2.1 dev dummy1
ip neigh add 192.0.2.2 dev dummy1 nud failed
echo ".2 failed:"  # results should not use .2
for i in {10..19}; do ip -o rou get 198.51.100.$i; done
ip link del dummy1

ip link add dummy1 up type dummy
ip nexthop add id 1 via 192.0.2.1 dev dummy1 onlink
ip nexthop add id 2 via 192.0.2.2 dev dummy1 onlink
ip nexthop add id 1001 group 1/2
ip rou add 198.51.100.0/24 nhid 1001
for i in {10..19}; do ip -o rou get 198.51.100.$i; done
ip neigh add 192.0.2.1 dev dummy1 nud failed
echo ".1 failed:"  # results should not use .1
for i in {10..19}; do ip -o rou get 198.51.100.$i; done
ip neigh del 192.0.2.1 dev dummy1
ip neigh add 192.0.2.2 dev dummy1 nud failed
echo ".2 failed:"  # results should not use .2
for i in {10..19}; do ip -o rou get 198.51.100.$i; done
ip link del dummy1

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Benjamin Poirier <bpoirier@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20230719-nh_select-v2-3-04383e89f868@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-20 20:23:20 -07:00
Benjamin Poirier
4bb5239b43 nexthop: Factor out neighbor validity check
For legacy nexthops, there is fib_good_nh() to check the neighbor validity.
In order to make the nexthop object code more similar to the legacy nexthop
code, factor out the nexthop object neighbor validity check into its own
function.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Benjamin Poirier <bpoirier@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20230719-nh_select-v2-2-04383e89f868@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-20 20:23:20 -07:00
Benjamin Poirier
eedd47a6ec nexthop: Factor out hash threshold fdb nexthop selection
The loop in nexthop_select_path_hthr() includes code to check for neighbor
validity. Since this does not apply to fdb nexthops, simplify the loop by
moving the fdb nexthop selection to its own function.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Benjamin Poirier <bpoirier@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20230719-nh_select-v2-1-04383e89f868@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-20 20:23:20 -07:00
Eric Dumazet
09eed1192c neighbour: switch to standard rcu, instead of rcu_bh
rcu_bh is no longer a win, especially for objects freed
with standard call_rcu().

Switch neighbour code to no longer disable BH when not necessary.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-03-21 21:32:18 -07:00
Eric Dumazet
b071af5235 neighbour: annotate lockless accesses to n->nud_state
We have many lockless accesses to n->nud_state.

Before adding another one in the following patch,
add annotations to readers and writers.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-03-15 00:37:32 -07:00
Nicolas Dichtel
bac0f937c3 nh: fix scope used to find saddr when adding non gw nh
As explained by Julian, fib_nh_scope is related to fib_nh_gw4, but
fib_info_update_nhc_saddr() needs the scope of the route, which is
the scope "before" fib_nh_scope, ie fib_nh_scope - 1.

This patch fixes the problem described in commit 747c143072 ("ip: fix
dflt addr selection for connected nexthop").

Fixes: 597cfe4fc3 ("nexthop: Add support for IPv4 nexthops")
Link: https://lore.kernel.org/netdev/6c8a44ba-c2d5-cdf-c5c7-5baf97cba38@ssi.bg/
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-10-27 10:17:40 -07:00
Kuniyuki Iwashima
bdf00bf24b nexthop: Fix data-races around nexthop_compat_mode.
While reading nexthop_compat_mode, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.

Fixes: 4f80116d3d ("net: ipv4: add sysctl for nexthop api compatibility mode")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-13 12:56:50 +01:00
Eric Dumazet
fea7b20132 nexthop: change nexthop_net_exit() to nexthop_net_exit_batch()
cleanup_net() is competing with other rtnl users.

nexthop_net_exit() seems a good candidate for exit_batch(),
as this gives chance for cleanup_net() to progress much faster,
holding rtnl a bit longer.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-02-08 20:41:33 -08:00
Jakub Kicinski
b6459415b3 net: Don't include filter.h from net/sock.h
sock.h is pretty heavily used (5k objects rebuilt on x86 after
it's touched). We can drop the include of filter.h from it and
add a forward declaration of struct sk_filter instead.
This decreases the number of rebuilt objects when bpf.h
is touched from ~5k to ~1k.

There's a lot of missing includes this was masking. Primarily
in networking tho, this time.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Acked-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/bpf/20211229004913.513372-1-kuba@kernel.org
2021-12-29 08:48:14 -08:00
Nikolay Aleksandrov
7709efa62c net: nexthop: reduce rcu synchronizations when replacing resilient groups
We can optimize resilient nexthop group replaces by reducing the number of
synchronize_net calls. After commit 1005f19b93 ("net: nexthop: release
IPv6 per-cpu dsts when replacing a nexthop group") we always do a
synchronize_net because we must ensure no new dsts can be created for the
replaced group's removed nexthops, but we already did that when replacing
resilient groups, so if we always call synchronize_net after any group
type replacement we'll take care of both cases and reduce synchronize_net
calls for resilient groups.

Suggested-by: Ido Schimmel <idosch@idosch.org>
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-11-30 11:59:18 +00:00
Nikolay Aleksandrov
1c743127cc net: nexthop: fix null pointer dereference when IPv6 is not enabled
When we try to add an IPv6 nexthop and IPv6 is not enabled
(!CONFIG_IPV6) we'll hit a NULL pointer dereference[1] in the error path
of nh_create_ipv6() due to calling ipv6_stub->fib6_nh_release. The bug
has been present since the beginning of IPv6 nexthop gateway support.
Commit 1aefd3de7b ("ipv6: Add fib6_nh_init and release to stubs") tells
us that only fib6_nh_init has a dummy stub because fib6_nh_release should
not be called if fib6_nh_init returns an error, but the commit below added
a call to ipv6_stub->fib6_nh_release in its error path. To fix it return
the dummy stub's -EAFNOSUPPORT error directly without calling
ipv6_stub->fib6_nh_release in nh_create_ipv6()'s error path.

[1]
 Output is a bit truncated, but it clearly shows the error.
 BUG: kernel NULL pointer dereference, address: 000000000000000000
 #PF: supervisor instruction fetch in kernel modede
 #PF: error_code(0x0010) - not-present pagege
 PGD 0 P4D 0
 Oops: 0010 [#1] PREEMPT SMP NOPTI
 CPU: 4 PID: 638 Comm: ip Kdump: loaded Not tainted 5.16.0-rc1+ #446
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-4.fc34 04/01/2014
 RIP: 0010:0x0
 Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
 RSP: 0018:ffff888109f5b8f0 EFLAGS: 00010286^Ac
 RAX: 0000000000000000 RBX: ffff888109f5ba28 RCX: 0000000000000000
 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8881008a2860
 RBP: ffff888109f5b9d8 R08: 0000000000000000 R09: 0000000000000000
 R10: ffff888109f5b978 R11: ffff888109f5b948 R12: 00000000ffffff9f
 R13: ffff8881008a2a80 R14: ffff8881008a2860 R15: ffff8881008a2840
 FS:  00007f98de70f100(0000) GS:ffff88822bf00000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: ffffffffffffffd6 CR3: 0000000100efc000 CR4: 00000000000006e0
 Call Trace:
  <TASK>
  nh_create_ipv6+0xed/0x10c
  rtm_new_nexthop+0x6d7/0x13f3
  ? check_preemption_disabled+0x3d/0xf2
  ? lock_is_held_type+0xbe/0xfd
  rtnetlink_rcv_msg+0x23f/0x26a
  ? check_preemption_disabled+0x3d/0xf2
  ? rtnl_calcit.isra.0+0x147/0x147
  netlink_rcv_skb+0x61/0xb2
  netlink_unicast+0x100/0x187
  netlink_sendmsg+0x37f/0x3a0
  ? netlink_unicast+0x187/0x187
  sock_sendmsg_nosec+0x67/0x9b
  ____sys_sendmsg+0x19d/0x1f9
  ? copy_msghdr_from_user+0x4c/0x5e
  ? rcu_read_lock_any_held+0x2a/0x78
  ___sys_sendmsg+0x6c/0x8c
  ? asm_sysvec_apic_timer_interrupt+0x12/0x20
  ? lockdep_hardirqs_on+0xd9/0x102
  ? sockfd_lookup_light+0x69/0x99
  __sys_sendmsg+0x50/0x6e
  do_syscall_64+0xcb/0xf2
  entry_SYSCALL_64_after_hwframe+0x44/0xae
 RIP: 0033:0x7f98dea28914
 Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b5 0f 1f 80 00 00 00 00 48 8d 05 e9 5d 0c 00 8b 00 85 c0 75 13 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 41 54 41 89 d4 55 48 89 f5 53
 RSP: 002b:00007fff859f5e68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e2e
 RAX: ffffffffffffffda RBX: 00000000619cb810 RCX: 00007f98dea28914
 RDX: 0000000000000000 RSI: 00007fff859f5ed0 RDI: 0000000000000003
 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000008
 R10: fffffffffffffce6 R11: 0000000000000246 R12: 0000000000000001
 R13: 000055c0097ae520 R14: 000055c0097957fd R15: 00007fff859f63a0
 </TASK>
 Modules linked in: bridge stp llc bonding virtio_net

Cc: stable@vger.kernel.org
Fixes: 53010f991a ("nexthop: Add support for IPv6 gateways")
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-11-23 11:39:53 +00:00
Nikolay Aleksandrov
1005f19b93 net: nexthop: release IPv6 per-cpu dsts when replacing a nexthop group
When replacing a nexthop group, we must release the IPv6 per-cpu dsts of
the removed nexthop entries after an RCU grace period because they
contain references to the nexthop's net device and to the fib6 info.
With specific series of events[1] we can reach net device refcount
imbalance which is unrecoverable. IPv4 is not affected because dsts
don't take a refcount on the route.

[1]
 $ ip nexthop list
  id 200 via 2002:db8::2 dev bridge.10 scope link onlink
  id 201 via 2002:db8::3 dev bridge scope link onlink
  id 203 group 201/200
 $ ip -6 route
  2001:db8::10 nhid 203 metric 1024 pref medium
     nexthop via 2002:db8::3 dev bridge weight 1 onlink
     nexthop via 2002:db8::2 dev bridge.10 weight 1 onlink

Create rt6_info through one of the multipath legs, e.g.:
 $ taskset -a -c 1  ./pkt_inj 24 bridge.10 2001:db8::10
 (pkt_inj is just a custom packet generator, nothing special)

Then remove that leg from the group by replace (let's assume it is id
200 in this case):
 $ ip nexthop replace id 203 group 201

Now remove the IPv6 route:
 $ ip -6 route del 2001:db8::10/128

The route won't be really deleted due to the stale rt6_info holding 1
refcnt in nexthop id 200.
At this point we have the following reference count dependency:
 (deleted) IPv6 route holds 1 reference over nhid 203
 nh 203 holds 1 ref over id 201
 nh 200 holds 1 ref over the net device and the route due to the stale
 rt6_info

Now to create circular dependency between nh 200 and the IPv6 route, and
also to get a reference over nh 200, restore nhid 200 in the group:
 $ ip nexthop replace id 203 group 201/200

And now we have a permanent circular dependncy because nhid 203 holds a
reference over nh 200 and 201, but the route holds a ref over nh 203 and
is deleted.

To trigger the bug just delete the group (nhid 203):
 $ ip nexthop del id 203

It won't really be deleted due to the IPv6 route dependency, and now we
have 2 unlinked and deleted objects that reference each other: the group
and the IPv6 route. Since the group drops the reference it holds over its
entries at free time (i.e. its own refcount needs to drop to 0) that will
never happen and we get a permanent ref on them, since one of the entries
holds a reference over the IPv6 route it will also never be released.

At this point the dependencies are:
 (deleted, only unlinked) IPv6 route holds reference over group nh 203
 (deleted, only unlinked) group nh 203 holds reference over nh 201 and 200
 nh 200 holds 1 ref over the net device and the route due to the stale
 rt6_info

This is the last point where it can be fixed by running traffic through
nh 200, and specifically through the same CPU so the rt6_info (dst) will
get released due to the IPv6 genid, that in turn will free the IPv6
route, which in turn will free the ref count over the group nh 203.

If nh 200 is deleted at this point, it will never be released due to the
ref from the unlinked group 203, it will only be unlinked:
 $ ip nexthop del id 200
 $ ip nexthop
 $

Now we can never release that stale rt6_info, we have IPv6 route with ref
over group nh 203, group nh 203 with ref over nh 200 and 201, nh 200 with
rt6_info (dst) with ref over the net device and the IPv6 route. All of
these objects are only unlinked, and cannot be released, thus they can't
release their ref counts.

 Message from syslogd@dev at Nov 19 14:04:10 ...
  kernel:[73501.828730] unregister_netdevice: waiting for bridge.10 to become free. Usage count = 3
 Message from syslogd@dev at Nov 19 14:04:20 ...
  kernel:[73512.068811] unregister_netdevice: waiting for bridge.10 to become free. Usage count = 3

Fixes: 7bf4796dd0 ("nexthops: add support for replace")
Signed-off-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-11-22 15:44:49 +00:00
Ido Schimmel
3106a08475 nexthop: Fix memory leaks in nexthop notification chain listeners
syzkaller discovered memory leaks [1] that can be reduced to the
following commands:

 # ip nexthop add id 1 blackhole
 # devlink dev reload pci/0000:06:00.0

As part of the reload flow, mlxsw will unregister its netdevs and then
unregister from the nexthop notification chain. Before unregistering
from the notification chain, mlxsw will receive delete notifications for
nexthop objects using netdevs registered by mlxsw or their uppers. mlxsw
will not receive notifications for nexthops using netdevs that are not
dismantled as part of the reload flow. For example, the blackhole
nexthop above that internally uses the loopback netdev as its nexthop
device.

One way to fix this problem is to have listeners flush their nexthop
tables after unregistering from the notification chain. This is
error-prone as evident by this patch and also not symmetric with the
registration path where a listener receives a dump of all the existing
nexthops.

Therefore, fix this problem by replaying delete notifications for the
listener being unregistered. This is symmetric to the registration path
and also consistent with the netdev notification chain.

The above means that unregister_nexthop_notifier(), like
register_nexthop_notifier(), will have to take RTNL in order to iterate
over the existing nexthops and that any callers of the function cannot
hold RTNL. This is true for mlxsw and netdevsim, but not for the VXLAN
driver. To avoid a deadlock, change the latter to unregister its nexthop
listener without holding RTNL, making it symmetric to the registration
path.

[1]
unreferenced object 0xffff88806173d600 (size 512):
  comm "syz-executor.0", pid 1290, jiffies 4295583142 (age 143.507s)
  hex dump (first 32 bytes):
    41 9d 1e 60 80 88 ff ff 08 d6 73 61 80 88 ff ff  A..`......sa....
    08 d6 73 61 80 88 ff ff 01 00 00 00 00 00 00 00  ..sa............
  backtrace:
    [<ffffffff81a6b576>] kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline]
    [<ffffffff81a6b576>] slab_post_alloc_hook+0x96/0x490 mm/slab.h:522
    [<ffffffff81a716d3>] slab_alloc_node mm/slub.c:3206 [inline]
    [<ffffffff81a716d3>] slab_alloc mm/slub.c:3214 [inline]
    [<ffffffff81a716d3>] kmem_cache_alloc_trace+0x163/0x370 mm/slub.c:3231
    [<ffffffff82e8681a>] kmalloc include/linux/slab.h:591 [inline]
    [<ffffffff82e8681a>] kzalloc include/linux/slab.h:721 [inline]
    [<ffffffff82e8681a>] mlxsw_sp_nexthop_obj_group_create drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:4918 [inline]
    [<ffffffff82e8681a>] mlxsw_sp_nexthop_obj_new drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:5054 [inline]
    [<ffffffff82e8681a>] mlxsw_sp_nexthop_obj_event+0x59a/0x2910 drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:5239
    [<ffffffff813ef67d>] notifier_call_chain+0xbd/0x210 kernel/notifier.c:83
    [<ffffffff813f0662>] blocking_notifier_call_chain kernel/notifier.c:318 [inline]
    [<ffffffff813f0662>] blocking_notifier_call_chain+0x72/0xa0 kernel/notifier.c:306
    [<ffffffff8384b9c6>] call_nexthop_notifiers+0x156/0x310 net/ipv4/nexthop.c:244
    [<ffffffff83852bd8>] insert_nexthop net/ipv4/nexthop.c:2336 [inline]
    [<ffffffff83852bd8>] nexthop_add net/ipv4/nexthop.c:2644 [inline]
    [<ffffffff83852bd8>] rtm_new_nexthop+0x14e8/0x4d10 net/ipv4/nexthop.c:2913
    [<ffffffff833e9a78>] rtnetlink_rcv_msg+0x448/0xbf0 net/core/rtnetlink.c:5572
    [<ffffffff83608703>] netlink_rcv_skb+0x173/0x480 net/netlink/af_netlink.c:2504
    [<ffffffff833de032>] rtnetlink_rcv+0x22/0x30 net/core/rtnetlink.c:5590
    [<ffffffff836069de>] netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
    [<ffffffff836069de>] netlink_unicast+0x5ae/0x7f0 net/netlink/af_netlink.c:1340
    [<ffffffff83607501>] netlink_sendmsg+0x8e1/0xe30 net/netlink/af_netlink.c:1929
    [<ffffffff832fde84>] sock_sendmsg_nosec net/socket.c:704 [inline]
    [<ffffffff832fde84>] sock_sendmsg net/socket.c:724 [inline]
    [<ffffffff832fde84>] ____sys_sendmsg+0x874/0x9f0 net/socket.c:2409
    [<ffffffff83304a44>] ___sys_sendmsg+0x104/0x170 net/socket.c:2463
    [<ffffffff83304c01>] __sys_sendmsg+0x111/0x1f0 net/socket.c:2492
    [<ffffffff83304d5d>] __do_sys_sendmsg net/socket.c:2501 [inline]
    [<ffffffff83304d5d>] __se_sys_sendmsg net/socket.c:2499 [inline]
    [<ffffffff83304d5d>] __x64_sys_sendmsg+0x7d/0xc0 net/socket.c:2499

Fixes: 2a014b200b ("mlxsw: spectrum_router: Add support for nexthop objects")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-23 12:33:22 +01:00
Ido Schimmel
563f23b002 nexthop: Fix division by zero while replacing a resilient group
The resilient nexthop group torture tests in fib_nexthop.sh exposed a
possible division by zero while replacing a resilient group [1]. The
division by zero occurs when the data path sees a resilient nexthop
group with zero buckets.

The tests replace a resilient nexthop group in a loop while traffic is
forwarded through it. The tests do not specify the number of buckets
while performing the replacement, resulting in the kernel allocating a
stub resilient table (i.e, 'struct nh_res_table') with zero buckets.

This table should never be visible to the data path, but the old nexthop
group (i.e., 'oldg') might still be used by the data path when the stub
table is assigned to it.

Fix this by only assigning the stub table to the old nexthop group after
making sure the group is no longer used by the data path.

Tested with fib_nexthops.sh:

Tests passed: 222
Tests failed:   0

[1]
 divide error: 0000 [#1] PREEMPT SMP KASAN
 CPU: 0 PID: 1850 Comm: ping Not tainted 5.14.0-custom-10271-ga86eb53057fe #1107
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-4.fc34 04/01/2014
 RIP: 0010:nexthop_select_path+0x2d2/0x1a80
[...]
 Call Trace:
  fib_select_multipath+0x79b/0x1530
  fib_select_path+0x8fb/0x1c10
  ip_route_output_key_hash_rcu+0x1198/0x2da0
  ip_route_output_key_hash+0x190/0x340
  ip_route_output_flow+0x21/0x120
  raw_sendmsg+0x91d/0x2e10
  inet_sendmsg+0x9e/0xe0
  __sys_sendto+0x23d/0x360
  __x64_sys_sendto+0xe1/0x1b0
  do_syscall_64+0x35/0x80
  entry_SYSCALL_64_after_hwframe+0x44/0xae

Cc: stable@vger.kernel.org
Fixes: 283a72a559 ("nexthop: Add implementation of resilient next-hop groups")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-20 09:45:14 +01:00
Ryoga Saito
9aca491e0d Set fc_nlinfo in nh_create_ipv4, nh_create_ipv6
This patch fixes kernel NULL pointer dereference when creating nexthop
which is bound with SRv6 decapsulation. In the creation of nexthop,
__seg6_end_dt_vrf_build is called. __seg6_end_dt_vrf_build expects
fc_lninfo in fib6_config is set correctly, but it isn't set in
nh_create_ipv6, which causes kernel crash.

Here is steps to reproduce kernel crash:

1. modprobe vrf
2. ip -6 nexthop add encap seg6local action End.DT4 vrftable 1 dev eth0

We got the following message:

[  901.370336] BUG: kernel NULL pointer dereference, address: 0000000000000ba0
[  901.371658] #PF: supervisor read access in kernel mode
[  901.372672] #PF: error_code(0x0000) - not-present page
[  901.373672] PGD 0 P4D 0
[  901.374248] Oops: 0000 [#1] SMP PTI
[  901.374944] CPU: 0 PID: 8593 Comm: ip Not tainted 5.14-051400-generic #202108310811-Ubuntu
[  901.376404] Hardware name: Red Hat KVM, BIOS 1.11.1-4.module_el8.2.0+320+13f867d7 04/01/2014
[  901.377907] RIP: 0010:vrf_ifindex_lookup_by_table_id+0x19/0x90 [vrf]
[  901.379182] Code: c1 e9 72 ff ff ff e8 96 49 01 c2 66 0f 1f 44 00 00 0f 1f 44 00 00 55 48 89 e5 41 56 41 55 41 89 f5 41 54 53 8b 05 47 4c 00 00 <48> 8b 97 a0 0b 00 00 48 8b 1c c2 e8 57 27 53 c1 4c 8d a3 88 00 00
[  901.382652] RSP: 0018:ffffbf2d02043590 EFLAGS: 00010282
[  901.383746] RAX: 000000000000000b RBX: ffff990808255e70 RCX: ffffbf2d02043aa8
[  901.385436] RDX: 0000000000000001 RSI: 0000000000000001 RDI: 0000000000000000
[  901.386924] RBP: ffffbf2d020435b0 R08: 00000000000000c0 R09: ffff990808255e40
[  901.388537] R10: ffffffff83b08c90 R11: 0000000000000009 R12: 0000000000000000
[  901.389937] R13: 0000000000000001 R14: 0000000000000000 R15: 000000000000000b
[  901.391226] FS:  00007fe49381f740(0000) GS:ffff99087dc00000(0000) knlGS:0000000000000000
[  901.392737] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  901.393803] CR2: 0000000000000ba0 CR3: 000000000e3e8003 CR4: 0000000000770ef0
[  901.395122] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  901.396496] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  901.397833] PKRU: 55555554
[  901.398578] Call Trace:
[  901.399144]  l3mdev_ifindex_lookup_by_table_id+0x3b/0x70
[  901.400179]  __seg6_end_dt_vrf_build+0x34/0xd0
[  901.401067]  seg6_end_dt4_build+0x16/0x20
[  901.401904]  seg6_local_build_state+0x271/0x430
[  901.402797]  lwtunnel_build_state+0x81/0x130
[  901.403645]  fib_nh_common_init+0x82/0x100
[  901.404465]  ? sock_def_readable+0x4b/0x80
[  901.405285]  fib6_nh_init+0x115/0x7c0
[  901.406033]  nh_create_ipv6.isra.0+0xe1/0x140
[  901.406932]  rtm_new_nexthop+0x3b7/0xeb0
[  901.407828]  rtnetlink_rcv_msg+0x152/0x3a0
[  901.408663]  ? rtnl_calcit.isra.0+0x130/0x130
[  901.409535]  netlink_rcv_skb+0x55/0x100
[  901.410319]  rtnetlink_rcv+0x15/0x20
[  901.411026]  netlink_unicast+0x1a8/0x250
[  901.411813]  netlink_sendmsg+0x238/0x470
[  901.412602]  ? _copy_from_user+0x2b/0x60
[  901.413394]  sock_sendmsg+0x65/0x70
[  901.414112]  ____sys_sendmsg+0x218/0x290
[  901.414929]  ? copy_msghdr_from_user+0x5c/0x90
[  901.415814]  ___sys_sendmsg+0x81/0xc0
[  901.416559]  ? fsnotify_destroy_marks+0x27/0xf0
[  901.417447]  ? call_rcu+0xa4/0x230
[  901.418153]  ? kmem_cache_free+0x23f/0x410
[  901.418972]  ? dentry_free+0x37/0x70
[  901.419705]  ? mntput_no_expire+0x4c/0x260
[  901.420574]  __sys_sendmsg+0x62/0xb0
[  901.421297]  __x64_sys_sendmsg+0x1f/0x30
[  901.422057]  do_syscall_64+0x5c/0xc0
[  901.422756]  ? syscall_exit_to_user_mode+0x27/0x50
[  901.423675]  ? __x64_sys_close+0x12/0x40
[  901.424462]  ? do_syscall_64+0x69/0xc0
[  901.425219]  ? irqentry_exit_to_user_mode+0x9/0x20
[  901.426149]  ? irqentry_exit+0x19/0x30
[  901.426901]  ? exc_page_fault+0x89/0x160
[  901.427709]  ? asm_exc_page_fault+0x8/0x30
[  901.428536]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[  901.429514] RIP: 0033:0x7fe493945747
[  901.430248] Code: 64 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10
[  901.433549] RSP: 002b:00007ffe9932cf68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
[  901.434981] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe493945747
[  901.436303] RDX: 0000000000000000 RSI: 00007ffe9932cfe0 RDI: 0000000000000003
[  901.437607] RBP: 00000000613053f7 R08: 0000000000000001 R09: 00007ffe9932d07c
[  901.438990] R10: 000055f4a903a010 R11: 0000000000000246 R12: 0000000000000001
[  901.440340] R13: 0000000000000001 R14: 000055f4a802b163 R15: 000055f4a8042020
[  901.441630] Modules linked in: vrf nls_utf8 isofs nls_iso8859_1 dm_multipath scsi_dh_rdac scsi_dh_emc scsi_dh_alua intel_rapl_msr intel_rapl_common isst_if_mbox_msr isst_if_common nfit rapl input_leds joydev serio_raw qemu_fw_cfg mac_hid sch_fq_codel drm virtio_rng ip_tables x_tables autofs4 btrfs blake2b_generic zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel crypto_simd virtio_net net_failover cryptd psmouse virtio_blk failover i2c_piix4 pata_acpi floppy
[  901.450808] CR2: 0000000000000ba0
[  901.451514] ---[ end trace c27b934b99ade304 ]---
[  901.452403] RIP: 0010:vrf_ifindex_lookup_by_table_id+0x19/0x90 [vrf]
[  901.453626] Code: c1 e9 72 ff ff ff e8 96 49 01 c2 66 0f 1f 44 00 00 0f 1f 44 00 00 55 48 89 e5 41 56 41 55 41 89 f5 41 54 53 8b 05 47 4c 00 00 <48> 8b 97 a0 0b 00 00 48 8b 1c c2 e8 57 27 53 c1 4c 8d a3 88 00 00
[  901.456910] RSP: 0018:ffffbf2d02043590 EFLAGS: 00010282
[  901.457912] RAX: 000000000000000b RBX: ffff990808255e70 RCX: ffffbf2d02043aa8
[  901.459238] RDX: 0000000000000001 RSI: 0000000000000001 RDI: 0000000000000000
[  901.460552] RBP: ffffbf2d020435b0 R08: 00000000000000c0 R09: ffff990808255e40
[  901.461882] R10: ffffffff83b08c90 R11: 0000000000000009 R12: 0000000000000000
[  901.463208] R13: 0000000000000001 R14: 0000000000000000 R15: 000000000000000b
[  901.464529] FS:  00007fe49381f740(0000) GS:ffff99087dc00000(0000) knlGS:0000000000000000
[  901.466058] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  901.467189] CR2: 0000000000000ba0 CR3: 000000000e3e8003 CR4: 0000000000770ef0
[  901.468515] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  901.469858] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  901.471139] PKRU: 55555554

Signed-off-by: Ryoga Saito <contact@proelbtn.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-09-02 11:42:13 +01:00
Ido Schimmel
9e46fb656f nexthop: Restart nexthop dump based on last dumped nexthop identifier
Currently, a multi-part nexthop dump is restarted based on the number of
nexthops that have been dumped so far. This can result in a lot of
nexthops not being dumped when nexthops are simultaneously deleted:

 # ip nexthop | wc -l
 65536
 # ip nexthop flush
 Dump was interrupted and may be inconsistent.
 Flushed 36040 nexthops
 # ip nexthop | wc -l
 29496

Instead, restart the dump based on the nexthop identifier (fixed number)
of the last successfully dumped nexthop:

 # ip nexthop | wc -l
 65536
 # ip nexthop flush
 Dump was interrupted and may be inconsistent.
 Flushed 65536 nexthops
 # ip nexthop | wc -l
 0

Reported-by: Maksym Yaremchuk <maksymy@nvidia.com>
Tested-by: Maksym Yaremchuk <maksymy@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-19 15:20:34 -07:00
Petr Machata
de1d1ee3e3 nexthop: Rename artifacts related to legacy multipath nexthop groups
After resilient next-hop groups have been added recently, there are two
types of multipath next-hop groups: the legacy "mpath", and the new
"resilient". Calling the legacy next-hop group type "mpath" is unfortunate,
because that describes the fact that a packet could be forwarded in one of
several paths, which is also true for the resilient next-hop groups.

Therefore, to make the naming clearer, rename various artifacts to reflect
the assumptions made. Therefore as of this patch:

- The flag for multipath groups is nh_grp_entry::is_multipath. This
  includes the legacy and resilient groups, as well as any future group
  types that behave as multipath groups.
  Functions that assume this have "mpath" in the name.

- The flag for legacy multipath groups is nh_grp_entry::hash_threshold.
  Functions that assume this have "hthr" in the name.

- The flag for resilient groups is nh_grp_entry::resilient.
  Functions that assume this have "res" in the name.

Besides the above, struct nh_grp_entry::mpath was renamed to ::hthr as
well.

UAPI artifacts were obviously left intact.

Suggested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-28 17:53:39 -07:00
Petr Machata
15e1dd5703 nexthop: Enable resilient next-hop groups
Now that all the code is in place, stop rejecting requests to create
resilient next-hop groups.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-11 16:13:00 -08:00
Petr Machata
0b4818aabc nexthop: Notify userspace about bucket migrations
Nexthop replacements et.al. are notified through netlink, but if a delayed
work migrates buckets on the background, userspace will stay oblivious.
Notify these as RTM_NEWNEXTHOPBUCKET events.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-11 16:13:00 -08:00
Petr Machata
187d4c6b97 nexthop: Add netlink handlers for bucket get
Allow getting (but not setting) individual buckets to inspect the next hop
mapped therein, idle time, and flags.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-11 16:13:00 -08:00
Petr Machata
8a1bbabb03 nexthop: Add netlink handlers for bucket dump
Add a dump handler for resilient next hop buckets. When next-hop group ID
is given, it walks buckets of that group, otherwise it walks buckets of all
groups. It then dumps the buckets whose next hops match the given filtering
criteria.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-11 16:13:00 -08:00
Petr Machata
a2601e2b1e nexthop: Add netlink handlers for resilient nexthop groups
Implement the netlink messages that allow creation and dumping of resilient
nexthop groups.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-11 16:13:00 -08:00
Ido Schimmel
cfc15c1dbb nexthop: Allow reporting activity of nexthop buckets
The kernel periodically checks the idle time of nexthop buckets to
determine if they are idle and can be re-populated with a new nexthop.

When the resilient nexthop group is offloaded to hardware, the kernel
will not see activity on nexthop buckets unless it is reported from
hardware.

Add a function that can be periodically called by device drivers to
report activity on nexthop buckets after querying it from the underlying
device.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-11 16:13:00 -08:00