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Author SHA1 Message Date
Eric Dumazet
cef4902b0f net: reduce rtnetlink_rcv_msg() stack usage
IFLA_MAX is increasing slowly but surely.

Some compilers use more than 512 bytes of stack in rtnetlink_rcv_msg()
because it calls rtnl_calcit() for RTM_GETLINK message.

Use noinline_for_stack attribute to not inline rtnl_calcit(),
and directly use nla_for_each_attr_type() (Jakub suggestion)
because we only care about IFLA_EXT_MASK at this stage.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20240710151653.3786604-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-07-11 17:13:58 -07:00
Jakub Kicinski
5380d64f8d rtnetlink: move rtnl_lock handling out of af_netlink
Now that we have an intermediate layer of code for handling
rtnl-level netlink dump quirks, we can move the rtnl_lock
taking there.

For dump handlers with RTNL_FLAG_DUMP_SPLIT_NLM_DONE we can
avoid taking rtnl_lock just to generate NLM_DONE, once again.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-06-10 13:15:40 +01:00
Jakub Kicinski
5b4b62a169 rtnetlink: make the "split" NLM_DONE handling generic
Jaroslav reports Dell's OMSA Systems Management Data Engine
expects NLM_DONE in a separate recvmsg(), both for rtnl_dump_ifinfo()
and inet_dump_ifaddr(). We already added a similar fix previously in
commit 460b0d33cf ("inet: bring NLM_DONE out to a separate recv() again")

Instead of modifying all the dump handlers, and making them look
different than modern for_each_netdev_dump()-based dump handlers -
put the workaround in rtnetlink code. This will also help us move
the custom rtnl-locking from af_netlink in the future (in net-next).

Note that this change is not touching rtnl_dump_all(). rtnl_dump_all()
is different kettle of fish and a potential problem. We now mix families
in a single recvmsg(), but NLM_DONE is not coalesced.

Tested:

  ./cli.py --dbg-small-recv 4096 --spec netlink/specs/rt_addr.yaml \
           --dump getaddr --json '{"ifa-family": 2}'

  ./cli.py --dbg-small-recv 4096 --spec netlink/specs/rt_route.yaml \
           --dump getroute --json '{"rtm-family": 2}'

  ./cli.py --dbg-small-recv 4096 --spec netlink/specs/rt_link.yaml \
           --dump getlink

Fixes: 3e41af9076 ("rtnetlink: use xarray iterator to implement rtnl_dump_ifinfo()")
Fixes: cdb2f80f1c ("inet: use xa_array iterator to implement inet_dump_ifaddr()")
Reported-by: Jaroslav Pulchart <jaroslav.pulchart@gooddata.com>
Link: https://lore.kernel.org/all/CAK8fFZ7MKoFSEzMBDAOjoUt+vTZRRQgLDNXEOfdCCXSoXXKE0g@mail.gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-06-05 12:34:54 +01:00
Jakub Kicinski
e7073830cc 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/hisilicon/hns3/hns3pf/hclge_main.c
  35d92abfba ("net: hns3: fix kernel crash when devlink reload during initialization")
  2a1a1a7b5f ("net: hns3: add command queue trace for hns3")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-09 10:01:01 -07:00
Eric Dumazet
9cf621bd5f rtnetlink: allow rtnl_fill_link_netnsid() to run under RCU protection
We want to be able to run rtnl_fill_ifinfo() under RCU protection
instead of RTNL in the future.

All rtnl_link_ops->get_link_net() methods already using dev_net()
are ready. I added READ_ONCE() annotations on others.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-05-07 11:14:50 +02:00
Eric Dumazet
979aad40da rtnetlink: do not depend on RTNL in rtnl_xdp_prog_skb()
dev->xdp_prog is protected by RCU, we can lift RTNL requirement
from rtnl_xdp_prog_skb().

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-05-07 11:14:50 +02:00
Eric Dumazet
6890ab31d1 rtnetlink: do not depend on RTNL in rtnl_fill_proto_down()
Change dev_change_proto_down() and dev_change_proto_down_reason()
to write once on dev->proto_down and dev->proto_down_reason.

Then rtnl_fill_proto_down() can use READ_ONCE() annotations
and run locklessly.

rtnl_proto_down_size() should assume worst case,
because readng dev->proto_down_reason multiple
times would be racy without RTNL in the future.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-05-07 11:14:50 +02:00
Eric Dumazet
6747a5d499 rtnetlink: do not depend on RTNL for many attributes
Following device fields can be read locklessly
in rtnl_fill_ifinfo() :

type, ifindex, operstate, link_mode, mtu, min_mtu, max_mtu, group,
promiscuity, allmulti, num_tx_queues, gso_max_segs, gso_max_size,
gro_max_size, gso_ipv4_max_size, gro_ipv4_max_size, tso_max_size,
tso_max_segs, num_rx_queues.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-05-07 11:14:50 +02:00
Eric Dumazet
ad13b5b0d1 rtnetlink: do not depend on RTNL for IFLA_TXQLEN output
rtnl_fill_ifinfo() can read dev->tx_queue_len locklessly,
granted we add corresponding READ_ONCE()/WRITE_ONCE() annotations.

Add missing READ_ONCE(dev->tx_queue_len) in teql_enqueue()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-05-07 11:14:50 +02:00
Eric Dumazet
8a58268133 rtnetlink: do not depend on RTNL for IFLA_IFNAME output
We can use netdev_copy_name() to no longer rely on RTNL
to fetch dev->name.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-05-07 11:14:50 +02:00
Eric Dumazet
698419ffb6 rtnetlink: do not depend on RTNL for IFLA_QDISC output
dev->qdisc can be read using RCU protection.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-05-07 11:14:50 +02:00
Roded Zats
1aec77b2bb rtnetlink: Correct nested IFLA_VF_VLAN_LIST attribute validation
Each attribute inside a nested IFLA_VF_VLAN_LIST is assumed to be a
struct ifla_vf_vlan_info so the size of such attribute needs to be at least
of sizeof(struct ifla_vf_vlan_info) which is 14 bytes.
The current size validation in do_setvfinfo is against NLA_HDRLEN (4 bytes)
which is less than sizeof(struct ifla_vf_vlan_info) so this validation
is not enough and a too small attribute might be cast to a
struct ifla_vf_vlan_info, this might result in an out of bands
read access when accessing the saved (casted) entry in ivvl.

Fixes: 79aab093a0 ("net: Update API for VF vlan protocol 802.1ad support")
Signed-off-by: Roded Zats <rzats@paloaltonetworks.com>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20240502155751.75705-1-rzats@paloaltonetworks.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-03 15:57:50 -07:00
Eric Dumazet
0feb396f74 rtnetlink: use for_each_netdev_dump() in rtnl_stats_dump()
Switch rtnl_stats_dump() to use for_each_netdev_dump()
instead of net->dev_index_head[] hash table.

This makes the code much easier to read, and fixes
scalability issues.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240502113748.1622637-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-03 15:03:42 -07:00
Eric Dumazet
136c2a9a2a rtnetlink: change rtnl_stats_dump() return value
By returning 0 (or an error) instead of skb->len,
we allow NLMSG_DONE to be appended to the current
skb at the end of a dump, saving a couple of recvmsg()
system calls.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240502113748.1622637-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-05-03 15:03:42 -07:00
Johannes Berg
e8058a49e6 netlink: introduce type-checking attribute iteration
There are, especially with multi-attr arrays, many cases
of needing to iterate all attributes of a specific type
in a netlink message or a nested attribute. Add specific
macros to support that case.

Also convert many instances using this spatch:

    @@
    iterator nla_for_each_attr;
    iterator name nla_for_each_attr_type;
    identifier nla;
    expression head, len, rem;
    expression ATTR;
    type T;
    identifier x;
    @@
    -nla_for_each_attr(nla, head, len, rem)
    +nla_for_each_attr_type(nla, ATTR, head, len, rem)
     {
    <... T x; ...>
    -if (nla_type(nla) == ATTR) {
     ...
    -}
     }

    @@
    identifier nla;
    iterator nla_for_each_nested;
    iterator name nla_for_each_nested_type;
    expression attr, rem;
    expression ATTR;
    type T;
    identifier x;
    @@
    -nla_for_each_nested(nla, attr, rem)
    +nla_for_each_nested_type(nla, ATTR, attr, rem)
     {
    <... T x; ...>
    -if (nla_type(nla) == ATTR) {
     ...
    -}
     }

    @@
    iterator nla_for_each_attr;
    iterator name nla_for_each_attr_type;
    identifier nla;
    expression head, len, rem;
    expression ATTR;
    type T;
    identifier x;
    @@
    -nla_for_each_attr(nla, head, len, rem)
    +nla_for_each_attr_type(nla, ATTR, head, len, rem)
     {
    <... T x; ...>
    -if (nla_type(nla) != ATTR) continue;
     ...
     }

    @@
    identifier nla;
    iterator nla_for_each_nested;
    iterator name nla_for_each_nested_type;
    expression attr, rem;
    expression ATTR;
    type T;
    identifier x;
    @@
    -nla_for_each_nested(nla, attr, rem)
    +nla_for_each_nested_type(nla, ATTR, attr, rem)
     {
    <... T x; ...>
    -if (nla_type(nla) != ATTR) continue;
     ...
     }

Although I had to undo one bad change this made, and
I also adjusted some other code for whitespace and to
use direct variable initialization now.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/r/20240328203144.b5a6c895fb80.I1869b44767379f204998ff44dd239803f39c23e0@changeid
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-29 15:06:02 -07:00
Eric Dumazet
02e24903e5 netlink: let core handle error cases in dump operations
After commit b5a899154a ("netlink: handle EMSGSIZE errors
in the core"), we can remove some code that was not 100 % correct
anyway.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240306102426.245689-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-07 20:48:22 -08:00
Jakub Kicinski
e3afe5dd3a Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

No conflicts.

Adjacent changes:

net/core/page_pool_user.c
  0b11b1c5c3 ("netdev: let netlink core handle -EMSGSIZE errors")
  429679dcf7 ("page_pool: fix netlink dump stop/resume")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-07 10:29:36 -08:00
Jakub Kicinski
289e922582 dpll: move all dpll<>netdev helpers to dpll code
Older versions of GCC really want to know the full definition
of the type involved in rcu_assign_pointer().

struct dpll_pin is defined in a local header, net/core can't
reach it. Move all the netdev <> dpll code into dpll, where
the type is known. Otherwise we'd need multiple function calls
to jump between the compilation units.

This is the same problem the commit under fixes was trying to address,
but with rcu_assign_pointer() not rcu_dereference().

Some of the exports are not needed, networking core can't
be a module, we only need exports for the helpers used by
drivers.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/all/35a869c8-52e8-177-1d4d-e57578b99b6@linux-m68k.org/
Fixes: 640f41ed33 ("dpll: fix build failure due to rcu_dereference_check() on unknown type")
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240305013532.694866-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-03-05 18:36:42 -08:00
Jakub Kicinski
65f5dd4f02 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

net/mptcp/protocol.c
  adf1bb78da ("mptcp: fix snd_wnd initialization for passive socket")
  9426ce476a ("mptcp: annotate lockless access for RX path fields")
https://lore.kernel.org/all/20240228103048.19255709@canb.auug.org.au/

Adjacent changes:

drivers/dpll/dpll_core.c
  0d60d8df6f ("dpll: rely on rcu for netdev_dpll_pin()")
  e7f8df0e81 ("dpll: move xa_erase() call in to match dpll_pin_alloc() error path order")

drivers/net/veth.c
  1ce7d306ea ("veth: try harder when allocating queue memory")
  0bef512012 ("net: add netdev_lockdep_set_classes() to virtual drivers")

drivers/net/wireless/intel/iwlwifi/mvm/d3.c
  8c9bef26e9 ("wifi: iwlwifi: mvm: d3: implement suspend with MLO")
  78f65fbf42 ("wifi: iwlwifi: mvm: ensure offloading TID queue exists")

net/wireless/nl80211.c
  f78c137533 ("wifi: nl80211: reject iftype change with mesh ID change")
  414532d8aa ("wifi: cfg80211: use IEEE80211_MAX_MESH_ID_LEN appropriately")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-02-29 14:24:56 -08:00
Lin Ma
743ad091fb rtnetlink: fix error logic of IFLA_BRIDGE_FLAGS writing back
In the commit d73ef2d69c ("rtnetlink: let rtnl_bridge_setlink checks
IFLA_BRIDGE_MODE length"), an adjustment was made to the old loop logic
in the function `rtnl_bridge_setlink` to enable the loop to also check
the length of the IFLA_BRIDGE_MODE attribute. However, this adjustment
removed the `break` statement and led to an error logic of the flags
writing back at the end of this function.

if (have_flags)
    memcpy(nla_data(attr), &flags, sizeof(flags));
    // attr should point to IFLA_BRIDGE_FLAGS NLA !!!

Before the mentioned commit, the `attr` is granted to be IFLA_BRIDGE_FLAGS.
However, this is not necessarily true fow now as the updated loop will let
the attr point to the last NLA, even an invalid NLA which could cause
overflow writes.

This patch introduces a new variable `br_flag` to save the NLA pointer
that points to IFLA_BRIDGE_FLAGS and uses it to resolve the mentioned
error logic.

Fixes: d73ef2d69c ("rtnetlink: let rtnl_bridge_setlink checks IFLA_BRIDGE_MODE length")
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://lore.kernel.org/r/20240227121128.608110-1-linma@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-02-28 19:38:03 -08:00
Eric Dumazet
0ec4e48c3a rtnetlink: provide RCU protection to rtnl_fill_prop_list()
We want to be able to run rtnl_fill_ifinfo() under RCU protection
instead of RTNL in the future.

dev->name_node items are already rcu protected.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-26 11:46:13 +00:00
Eric Dumazet
74808e72e0 rtnetlink: make rtnl_fill_link_ifmap() RCU ready
Use READ_ONCE() to read the following device fields:

	dev->mem_start
	dev->mem_end
	dev->base_addr
	dev->irq
	dev->dma
	dev->if_port

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-26 11:46:13 +00:00
Eric Dumazet
386520e0ec rtnetlink: add RTNL_FLAG_DUMP_UNLOCKED flag
Similarly to RTNL_FLAG_DOIT_UNLOCKED, this new flag
allows dump operations registered via rtnl_register()
or rtnl_register_module() to opt-out from RTNL protection.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-26 11:46:12 +00:00
Eric Dumazet
e353ea9ce4 rtnetlink: prepare nla_put_iflink() to run under RCU
We want to be able to run rtnl_fill_ifinfo() under RCU protection
instead of RTNL in the future.

This patch prepares dev_get_iflink() and nla_put_iflink()
to run either with RTNL or RCU held.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-26 11:46:12 +00:00
Jakub Kicinski
73be9a3aab Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

No conflicts.

Adjacent changes:

net/core/dev.c
  9f30831390 ("net: add rcu safety to rtnl_prop_list_size()")
  723de3ebef ("net: free altname using an RCU callback")

net/unix/garbage.c
  11498715f2 ("af_unix: Remove io_uring code for GC.")
  25236c91b5 ("af_unix: Fix task hung while purging oob_skb in GC.")

drivers/net/ethernet/renesas/ravb_main.c
  ed4adc0720 ("net: ravb: Count packets instead of descriptors in GbEth RX path"
)
  c2da940857 ("ravb: Add Rx checksum offload support for GbEth")

net/mptcp/protocol.c
  bdd70eb689 ("mptcp: drop the push_pending field")
  28e5c13805 ("mptcp: annotate lockless accesses around read-mostly fields")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-02-15 16:20:04 -08:00
Eric Dumazet
2dd4d828d6 net: remove dev_base_lock from do_setlink()
We hold RTNL here, and dev->link_mode readers already
are using READ_ONCE().

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-14 11:20:14 +00:00
Eric Dumazet
6a2968ee1e net: add netdev_set_operstate() helper
dev_base_lock is going away, add netdev_set_operstate() helper
so that hsr does not have to know core internals.

Remove dev_base_lock acquisition from rfc2863_policy()

v3: use an "unsigned int" for dev->operstate,
    so that try_cmpxchg() can work on all arches.
        ( https://lore.kernel.org/oe-kbuild-all/202402081918.OLyGaea3-lkp@intel.com/ )

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-14 11:20:13 +00:00
Eric Dumazet
004d138364 net-sysfs: convert dev->operstate reads to lockless ones
operstate_show() can omit dev_base_lock acquisition only
to read dev->operstate.

Annotate accesses to dev->operstate.

Writers still acquire dev_base_lock for mutual exclusion.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-14 11:20:13 +00:00
Eric Dumazet
a6473fe9b6 dev: annotate accesses to dev->link
Following patch will read dev->link locklessly,
annotate the write from do_setlink().

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-14 11:20:13 +00:00
Eric Dumazet
3e41af9076 rtnetlink: use xarray iterator to implement rtnl_dump_ifinfo()
Adopt net->dev_by_index as I did in commit 0e0939c0ad
("net-procfs: use xarray iterator to implement /proc/net/dev")

This makes sure an existing device is always visible in the dump,
regardless of concurrent insertions/deletions.

v2: added suggestions from Jakub Kicinski and Ido Schimmel,
    thanks for the help !

Link: https://lore.kernel.org/all/20240209142441.6c56435b@kernel.org/
Link: https://lore.kernel.org/all/ZckR-XOsULLI9EHc@shredder/
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/20240211214404.1882191-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-02-13 18:34:50 -08:00
Eric Dumazet
9f30831390 net: add rcu safety to rtnl_prop_list_size()
rtnl_prop_list_size() can be called while alternative names
are added or removed concurrently.

if_nlmsg_size() / rtnl_calcit() can indeed be called
without RTNL held.

Use explicit RCU protection to avoid UAF.

Fixes: 88f4fb0c74 ("net: rtnetlink: put alternative names to getlink message")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20240209181248.96637-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-02-12 17:38:52 -08:00
Eric Dumazet
ffabe98cb5 net: make dev_unreg_count global
We can use a global dev_unreg_count counter instead
of a per netns one.

As a bonus we can factorize the changes done on it
for bulk device removals.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-02-04 16:08:21 +00:00
Nicolas Dichtel
ec4ffd100f Revert "net: rtnetlink: Enslave device before bringing it up"
This reverts commit a4abfa627c.

The patch broke:
> ip link set dummy0 up
> ip link set dummy0 master bond0 down

This last command is useful to be able to enslave an interface with only
one netlink message.

After discussion, there is no good reason to support:
> ip link set dummy0 down
> ip link set dummy0 master bond0 up
because the bond interface already set the slave up when it is up.

Cc: stable@vger.kernel.org
Fixes: a4abfa627c ("net: rtnetlink: Enslave device before bringing it up")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Hangbin Liu <liuhangbin@gmail.com>
Link: https://lore.kernel.org/r/20240108094103.2001224-2-nicolas.dichtel@6wind.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-01-11 16:47:40 -08:00
Ido Schimmel
2601e9c4b1 rtnetlink: bridge: Enable MDB bulk deletion
Now that both the common code as well as individual drivers support MDB
bulk deletion, allow user space to make such requests.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-12-20 11:27:21 +00:00
Ido Schimmel
d8e81f1311 rtnetlink: bridge: Invoke MDB bulk deletion when needed
Invoke the new MDB bulk deletion device operation when the 'NLM_F_BULK'
flag is set in the netlink message header.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-12-20 11:27:20 +00:00
Ido Schimmel
e0cd06f7fc rtnetlink: bridge: Use a different policy for MDB bulk delete
For MDB bulk delete we will need to validate 'MDBA_SET_ENTRY'
differently compared to regular delete. Specifically, allow the ifindex
to be zero (in case not filtering on bridge port) and force the address
to be zero as bulk delete based on address is not supported.

Do that by introducing a new policy and choosing the correct policy
based on the presence of the 'NLM_F_BULK' flag in the netlink message
header. Use nlmsg_parse() for strict validation.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-12-20 11:27:20 +00:00
Pedro Tammela
174523479a net: rtnl: use rcu_replace_pointer_rtnl in rtnl_unregister_*
With the introduction of the rcu_replace_pointer_rtnl helper,
cleanup the rtnl_unregister_* functions to use the helper instead
of open coding it.

Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-12-18 02:05:45 +00:00
Johannes Berg
facd15dfd6 net: core: synchronize link-watch when carrier is queried
There are multiple ways to query for the carrier state: through
rtnetlink, sysfs, and (possibly) ethtool. Synchronize linkwatch
work before these operations so that we don't have a situation
where userspace queries the carrier state between the driver's
carrier off->on transition and linkwatch running and expects it
to work, when really (at least) TX cannot work until linkwatch
has run.

I previously posted a longer explanation of how this applies to
wireless [1] but with this wireless can simply query the state
before sending data, to ensure the kernel is ready for it.

[1] https://lore.kernel.org/all/346b21d87c69f817ea3c37caceb34f1f56255884.camel@sipsolutions.net/

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20231204214706.303c62768415.I1caedccae72ee5a45c9085c5eb49c145ce1c0dd5@changeid
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-12-05 20:16:45 -08:00
Li RongQing
ac40916a3f rtnetlink: introduce nlmsg_new_large and use it in rtnl_getlink
if a PF has 256 or more VFs, ip link command will allocate an order 3
memory or more, and maybe trigger OOM due to memory fragment,
the VFs needed memory size is computed in rtnl_vfinfo_size.

so introduce nlmsg_new_large which calls netlink_alloc_large_skb in
which vmalloc is used for large memory, to avoid the failure of
allocating memory

    ip invoked oom-killer: gfp_mask=0xc2cc0(GFP_KERNEL|__GFP_NOWARN|\
	__GFP_COMP|__GFP_NOMEMALLOC), order=3, oom_score_adj=0
    CPU: 74 PID: 204414 Comm: ip Kdump: loaded Tainted: P           OE
    Call Trace:
    dump_stack+0x57/0x6a
    dump_header+0x4a/0x210
    oom_kill_process+0xe4/0x140
    out_of_memory+0x3e8/0x790
    __alloc_pages_slowpath.constprop.116+0x953/0xc50
    __alloc_pages_nodemask+0x2af/0x310
    kmalloc_large_node+0x38/0xf0
    __kmalloc_node_track_caller+0x417/0x4d0
    __kmalloc_reserve.isra.61+0x2e/0x80
    __alloc_skb+0x82/0x1c0
    rtnl_getlink+0x24f/0x370
    rtnetlink_rcv_msg+0x12c/0x350
    netlink_rcv_skb+0x50/0x100
    netlink_unicast+0x1b2/0x280
    netlink_sendmsg+0x355/0x4a0
    sock_sendmsg+0x5b/0x60
    ____sys_sendmsg+0x1ea/0x250
    ___sys_sendmsg+0x88/0xd0
    __sys_sendmsg+0x5e/0xa0
    do_syscall_64+0x33/0x40
    entry_SYSCALL_64_after_hwframe+0x44/0xa9
    RIP: 0033:0x7f95a65a5b70

Cc: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Link: https://lore.kernel.org/r/20231115120108.3711-1-lirongqing@baidu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-11-18 20:18:25 -08:00
Ido Schimmel
ddd17a54e6 rtnetlink: Add MDB get support
Now that both the bridge and VXLAN drivers implement the MDB get net
device operation, expose the functionality to user space by registering
a handler for RTM_GETMDB messages. Derive the net device from the
ifindex specified in the ancillary header and invoke its MDB get NDO.

Note that unlike other get handlers, the allocation of the skb
containing the response is not performed in the common rtnetlink code as
the size is variable and needs to be determined by the respective
driver.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-27 10:51:42 +01:00
Jakub Kicinski
041c3466f3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

net/mac80211/key.c
  02e0e426a2 ("wifi: mac80211: fix error path key leak")
  2a8b665e6b ("wifi: mac80211: remove key_mtx")
  7d6904bf26 ("Merge wireless into wireless-next")
https://lore.kernel.org/all/20231012113648.46eea5ec@canb.auug.org.au/

Adjacent changes:

drivers/net/ethernet/ti/Kconfig
  a602ee3176 ("net: ethernet: ti: Fix mixed module-builtin object")
  98bdeae950 ("net: cpmac: remove driver to prepare for platform removal")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-19 13:29:01 -07:00
Christoph Paasch
503930f8e1 netlink: Correct offload_xstats size
rtnl_offload_xstats_get_size_hw_s_info_one() conditionalizes the
size-computation for IFLA_OFFLOAD_XSTATS_HW_S_INFO_USED based on whether
or not the device has offload_xstats enabled.

However, rtnl_offload_xstats_fill_hw_s_info_one() is adding the u8 for
that field uncondtionally.

syzkaller triggered a WARNING in rtnl_stats_get due to this:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 754 at net/core/rtnetlink.c:5982 rtnl_stats_get+0x2f4/0x300
Modules linked in:
CPU: 0 PID: 754 Comm: syz-executor148 Not tainted 6.6.0-rc2-g331b78eb12af #45
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
RIP: 0010:rtnl_stats_get+0x2f4/0x300 net/core/rtnetlink.c:5982
Code: ff ff 89 ee e8 7d 72 50 ff 83 fd a6 74 17 e8 33 6e 50 ff 4c 89 ef be 02 00 00 00 e8 86 00 fa ff e9 7b fe ff ff e8 1c 6e 50 ff <0f> 0b eb e5 e8 73 79 7b 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc900006837c0 EFLAGS: 00010293
RAX: ffffffff81cf7f24 RBX: ffff8881015d9000 RCX: ffff888101815a00
RDX: 0000000000000000 RSI: 00000000ffffffa6 RDI: 00000000ffffffa6
RBP: 00000000ffffffa6 R08: ffffffff81cf7f03 R09: 0000000000000001
R10: ffff888101ba47b9 R11: ffff888101815a00 R12: ffff8881017dae00
R13: ffff8881017dad00 R14: ffffc90000683ab8 R15: ffffffff83c1f740
FS:  00007fbc22dbc740(0000) GS:ffff88813bc00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000046 CR3: 000000010264e003 CR4: 0000000000170ef0
Call Trace:
 <TASK>
 rtnetlink_rcv_msg+0x677/0x710 net/core/rtnetlink.c:6480
 netlink_rcv_skb+0xea/0x1c0 net/netlink/af_netlink.c:2545
 netlink_unicast+0x430/0x500 net/netlink/af_netlink.c:1342
 netlink_sendmsg+0x4fc/0x620 net/netlink/af_netlink.c:1910
 sock_sendmsg+0xa8/0xd0 net/socket.c:730
 ____sys_sendmsg+0x22a/0x320 net/socket.c:2541
 ___sys_sendmsg+0x143/0x190 net/socket.c:2595
 __x64_sys_sendmsg+0xd8/0x150 net/socket.c:2624
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x47/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x6e/0xd8
RIP: 0033:0x7fbc22e8d6a9
Code: 5c c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 4f 37 0d 00 f7 d8 64 89 01 48
RSP: 002b:00007ffc4320e778 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004007d0 RCX: 00007fbc22e8d6a9
RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 0000000000000001 R08: 0000000000000000 R09: 00000000004007d0
R10: 0000000000000008 R11: 0000000000000246 R12: 00007ffc4320e898
R13: 00007ffc4320e8a8 R14: 00000000004004a0 R15: 00007fbc22fa5a80
 </TASK>
---[ end trace 0000000000000000 ]---

Which didn't happen prior to commit bf9f1baa27 ("net: add dedicated
kmem_cache for typical/small skb->head") as the skb always was large
enough.

Fixes: 0e7788fd76 ("net: rtnetlink: Add UAPI for obtaining L3 offload xstats")
Signed-off-by: Christoph Paasch <cpaasch@apple.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Link: https://lore.kernel.org/r/20231013041448.8229-1-cpaasch@apple.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-16 17:32:59 -07:00
Amit Cohen
38985e8c27 net: Handle bulk delete policy in bridge driver
The merge commit 9271686937 ("Merge branch 'br-flush-filtering'")
added support for FDB flushing in bridge driver. The following patches
will extend VXLAN driver to support FDB flushing as well. The netlink
message for bulk delete is shared between the drivers. With the existing
implementation, there is no way to prevent user from flushing with
attributes that are not supported per driver. For example, when VNI will
be added, user will not get an error for flush FDB entries in bridge
with VNI, although this attribute is not relevant for bridge.

As preparation for support of FDB flush in VXLAN driver, move the policy
to be handled in bridge driver, later a new policy for VXLAN will be
added in VXLAN driver. Do not pass 'vid' as part of ndo_fdb_del_bulk(),
as this field is relevant only for bridge.

Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-13 10:00:30 +01:00
Jiri Pirko
5f18426928 netdev: expose DPLL pin handle for netdevice
In case netdevice represents a SyncE port, the user needs to understand
the connection between netdevice and associated DPLL pin. There might me
multiple netdevices pointing to the same pin, in case of VF/SF
implementation.

Add a IFLA Netlink attribute to nest the DPLL pin handle, similar to
how it is implemented for devlink port. Add a struct dpll_pin pointer
to netdev and protect access to it by RTNL. Expose netdev_dpll_pin_set()
and netdev_dpll_pin_clear() helpers to the drivers so they can set/clear
the DPLL pin relationship to netdev.

Note that during the lifetime of struct dpll_pin the pin handle does not
change. Therefore it is save to access it lockless. It is drivers
responsibility to call netdev_dpll_pin_clear() before dpll_pin_put().

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Signed-off-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-09-17 11:50:20 +01:00
Jakub Kicinski
57ce6427e0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

include/net/inet_sock.h
  f866fbc842 ("ipv4: fix data-races around inet->inet_id")
  c274af2242 ("inet: introduce inet->inet_flags")
https://lore.kernel.org/all/679ddff6-db6e-4ff6-b177-574e90d0103d@tessares.net/

Adjacent changes:

drivers/net/bonding/bond_alb.c
  e74216b8de ("bonding: fix macvlan over alb bond support")
  f11e5bd159 ("bonding: support balance-alb with openvswitch")

drivers/net/ethernet/broadcom/bgmac.c
  d6499f0b7c ("net: bgmac: Return PTR_ERR() for fixed_phy_register()")
  23a14488ea ("net: bgmac: Fix return value check for fixed_phy_register()")

drivers/net/ethernet/broadcom/genet/bcmmii.c
  32bbe64a13 ("net: bcmgenet: Fix return value check for fixed_phy_register()")
  acf50d1adb ("net: bcmgenet: Return PTR_ERR() for fixed_phy_register()")

net/sctp/socket.c
  f866fbc842 ("ipv4: fix data-races around inet->inet_id")
  b09bde5c35 ("inet: move inet->mc_loop to inet->inet_frags")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-24 10:51:39 -07:00
Ido Schimmel
30188bd783 rtnetlink: Reject negative ifindexes in RTM_NEWLINK
Negative ifindexes are illegal, but the kernel does not validate the
ifindex in the ancillary header of RTM_NEWLINK messages, resulting in
the kernel generating a warning [1] when such an ifindex is specified.

Fix by rejecting negative ifindexes.

[1]
WARNING: CPU: 0 PID: 5031 at net/core/dev.c:9593 dev_index_reserve+0x1a2/0x1c0 net/core/dev.c:9593
[...]
Call Trace:
 <TASK>
 register_netdevice+0x69a/0x1490 net/core/dev.c:10081
 br_dev_newlink+0x27/0x110 net/bridge/br_netlink.c:1552
 rtnl_newlink_create net/core/rtnetlink.c:3471 [inline]
 __rtnl_newlink+0x115e/0x18c0 net/core/rtnetlink.c:3688
 rtnl_newlink+0x67/0xa0 net/core/rtnetlink.c:3701
 rtnetlink_rcv_msg+0x439/0xd30 net/core/rtnetlink.c:6427
 netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2545
 netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline]
 netlink_unicast+0x536/0x810 net/netlink/af_netlink.c:1368
 netlink_sendmsg+0x93c/0xe40 net/netlink/af_netlink.c:1910
 sock_sendmsg_nosec net/socket.c:728 [inline]
 sock_sendmsg+0xd9/0x180 net/socket.c:751
 ____sys_sendmsg+0x6ac/0x940 net/socket.c:2538
 ___sys_sendmsg+0x135/0x1d0 net/socket.c:2592
 __sys_sendmsg+0x117/0x1e0 net/socket.c:2621
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fixes: 38f7b870d4 ("[RTNETLINK]: Link creation API")
Reported-by: syzbot+5ba06978f34abb058571@syzkaller.appspotmail.com
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20230823064348.2252280-1-idosch@nvidia.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-08-24 09:45:52 +02:00
Jakub Kicinski
f534f6581e net: validate veth and vxcan peer ifindexes
veth and vxcan need to make sure the ifindexes of the peer
are not negative, core does not validate this.

Using iproute2 with user-space-level checking removed:

Before:

  # ./ip link add index 10 type veth peer index -1
  # ip link show
  1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
  2: enp1s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP mode DEFAULT group default qlen 1000
    link/ether 52:54:00:74:b2:03 brd ff:ff:ff:ff:ff:ff
  10: veth1@veth0: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
    link/ether 8a:90:ff:57:6d:5d brd ff:ff:ff:ff:ff:ff
  -1: veth0@veth1: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
    link/ether ae:ed:18:e6:fa:7f brd ff:ff:ff:ff:ff:ff

Now:

  $ ./ip link add index 10 type veth peer index -1
  Error: ifindex can't be negative.

This problem surfaced in net-next because an explicit WARN()
was added, the root cause is older.

Fixes: e6f8f1a739 ("veth: Allow to create peer link with given ifindex")
Fixes: a8f820a380 ("can: add Virtual CAN Tunnel driver (vxcan)")
Reported-by: syzbot+5ba06978f34abb058571@syzkaller.appspotmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-20 11:40:03 +01:00
Jakub Kicinski
35b1b1fd96 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

net/dsa/port.c
  9945c1fb03 ("net: dsa: fix older DSA drivers using phylink")
  a88dd75384 ("net: dsa: remove legacy_pre_march2020 detection")
https://lore.kernel.org/all/20230731102254.2c9868ca@canb.auug.org.au/

net/xdp/xsk.c
  3c5b4d69c3 ("net: annotate data-races around sk->sk_mark")
  b7f72a30e9 ("xsk: introduce wrappers and helpers for supporting multi-buffer in Tx path")
https://lore.kernel.org/all/20230731102631.39988412@canb.auug.org.au/

drivers/net/ethernet/broadcom/bnxt/bnxt.c
  37b61cda9c ("bnxt: don't handle XDP in netpoll")
  2b56b3d992 ("eth: bnxt: handle invalid Tx completions more gracefully")
https://lore.kernel.org/all/20230801101708.1dc7faac@canb.auug.org.au/

Adjacent changes:

drivers/net/ethernet/mellanox/mlx5/core/en_accel/ipsec_fs.c
  62da08331f ("net/mlx5e: Set proper IPsec source port in L4 selector")
  fbd517549c ("net/mlx5e: Add function to get IPsec offload namespace")

drivers/net/ethernet/sfc/selftest.c
  55c1528f9b ("sfc: fix field-spanning memcpy in selftest")
  ae9d445cd4 ("sfc: Miscellaneous comment removals")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-08-03 14:34:37 -07:00
Lin Ma
d73ef2d69c rtnetlink: let rtnl_bridge_setlink checks IFLA_BRIDGE_MODE length
There are totally 9 ndo_bridge_setlink handlers in the current kernel,
which are 1) bnxt_bridge_setlink, 2) be_ndo_bridge_setlink 3)
i40e_ndo_bridge_setlink 4) ice_bridge_setlink 5)
ixgbe_ndo_bridge_setlink 6) mlx5e_bridge_setlink 7)
nfp_net_bridge_setlink 8) qeth_l2_bridge_setlink 9) br_setlink.

By investigating the code, we find that 1-7 parse and use nlattr
IFLA_BRIDGE_MODE but 3 and 4 forget to do the nla_len check. This can
lead to an out-of-attribute read and allow a malformed nlattr (e.g.,
length 0) to be viewed as a 2 byte integer.

To avoid such issues, also for other ndo_bridge_setlink handlers in the
future. This patch adds the nla_len check in rtnl_bridge_setlink and
does an early error return if length mismatches. To make it works, the
break is removed from the parsing for IFLA_BRIDGE_FLAGS to make sure
this nla_for_each_nested iterates every attribute.

Fixes: b1edc14a3f ("ice: Implement ice_bridge_getlink and ice_bridge_setlink")
Fixes: 51616018dd ("i40e: Add support for getlink, setlink ndo ops")
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Reviewed-by: Hangbin Liu <liuhangbin@gmail.com>
Link: https://lore.kernel.org/r/20230726075314.1059224-1-linma@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-07-27 17:14:01 -07:00
Ido Schimmel
29cfb2aaa4 bridge: Add backup nexthop ID support
Add a new bridge port attribute that allows attaching a nexthop object
ID to an skb that is redirected to a backup bridge port with VLAN
tunneling enabled.

Specifically, when redirecting a known unicast packet, read the backup
nexthop ID from the bridge port that lost its carrier and set it in the
bridge control block of the skb before forwarding it via the backup
port. Note that reading the ID from the bridge port should not result in
a cache miss as the ID is added next to the 'backup_port' field that was
already accessed. After this change, the 'state' field still stays on
the first cache line, together with other data path related fields such
as 'flags and 'vlgrp':

struct net_bridge_port {
        struct net_bridge *        br;                   /*     0     8 */
        struct net_device *        dev;                  /*     8     8 */
        netdevice_tracker          dev_tracker;          /*    16     0 */
        struct list_head           list;                 /*    16    16 */
        long unsigned int          flags;                /*    32     8 */
        struct net_bridge_vlan_group * vlgrp;            /*    40     8 */
        struct net_bridge_port *   backup_port;          /*    48     8 */
        u32                        backup_nhid;          /*    56     4 */
        u8                         priority;             /*    60     1 */
        u8                         state;                /*    61     1 */
        u16                        port_no;              /*    62     2 */
        /* --- cacheline 1 boundary (64 bytes) --- */
[...]
} __attribute__((__aligned__(8)));

When forwarding an skb via a bridge port that has VLAN tunneling
enabled, check if the backup nexthop ID stored in the bridge control
block is valid (i.e., not zero). If so, instead of attaching the
pre-allocated metadata (that only has the tunnel key set), allocate a
new metadata, set both the tunnel key and the nexthop object ID and
attach it to the skb.

By default, do not dump the new attribute to user space as a value of
zero is an invalid nexthop object ID.

The above is useful for EVPN multihoming. When one of the links
composing an Ethernet Segment (ES) fails, traffic needs to be redirected
towards the host via one of the other ES peers. For example, if a host
is multihomed to three different VTEPs, the backup port of each ES link
needs to be set to the VXLAN device and the backup nexthop ID needs to
point to an FDB nexthop group that includes the IP addresses of the
other two VTEPs. The VXLAN driver will extract the ID from the metadata
of the redirected skb, calculate its flow hash and forward it towards
one of the other VTEPs. If the ID does not exist, or represents an
invalid nexthop object, the VXLAN driver will drop the skb. This
relieves the bridge driver from the need to validate the ID.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-07-19 10:53:49 +01:00