linux-stable.git/include/net/ip_fib.h, branch linux-5.4.y

ipv4: convert fib_num_tclassid_users to atomic_t

2021-12-08T08:01:12+00:00

commit 213f5f8f31f10aa1e83187ae20fb7fa4e626b724 upstream.

Before commit faa041a40b9f ("ipv4: Create cleanup helper for fib_nh")
changes to net->ipv4.fib_num_tclassid_users were protected by RTNL.

After the change, this is no longer the case, as free_fib_info_rcu()
runs after rcu grace period, without rtnl being held.

Fixes: faa041a40b9f ("ipv4: Create cleanup helper for fib_nh")
Signed-off-by: Eric Dumazet 
Cc: David Ahern 
Reviewed-by: David Ahern 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: ipv4: Fix rtnexthop len when RTA_FLOW is present

2021-10-06T13:42:33+00:00

[ Upstream commit 597aa16c782496bf74c5dc3b45ff472ade6cee64 ]

Multipath RTA_FLOW is embedded in nexthop. Dump it in fib_add_nexthop()
to get the length of rtnexthop correct.

Fixes: b0f60193632e ("ipv4: Refactor nexthop attributes in fib_dump_info")
Signed-off-by: Xiao Liang 
Reviewed-by: David Ahern 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

ipv4: nexthop version of fib_info_nh_uses_dev

2020-06-03T06:21:37+00:00

commit 1fd1c768f3624a5e66766e7b4ddb9b607cd834a5 upstream.

Similar to the last path, need to fix fib_info_nh_uses_dev for
external nexthops to avoid referencing multiple nh_grp structs.
Move the device check in fib_info_nh_uses_dev to a helper and
create a nexthop version that is called if the fib_info uses an
external nexthop.

Fixes: 430a049190de ("nexthop: Add support for nexthop groups")
Signed-off-by: David Ahern 
Acked-by: Nikolay Aleksandrov 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: don't return invalid table id error when we fall back to PF_UNSPEC

2020-06-03T06:20:41+00:00

[ Upstream commit 41b4bd986f86331efc599b9a3f5fb86ad92e9af9 ]

In case we can't find a ->dumpit callback for the requested
(family,type) pair, we fall back to (PF_UNSPEC,type). In effect, we're
in the same situation as if userspace had requested a PF_UNSPEC
dump. For RTM_GETROUTE, that handler is rtnl_dump_all, which calls all
the registered RTM_GETROUTE handlers.

The requested table id may or may not exist for all of those
families. commit ae677bbb4441 ("net: Don't return invalid table id
error when dumping all families") fixed the problem when userspace
explicitly requests a PF_UNSPEC dump, but missed the fallback case.

For example, when we pass ipv6.disable=1 to a kernel with
CONFIG_IP_MROUTE=y and CONFIG_IP_MROUTE_MULTIPLE_TABLES=y,
the (PF_INET6, RTM_GETROUTE) handler isn't registered, so we end up in
rtnl_dump_all, and listing IPv6 routes will unexpectedly print:

# ip -6 r
Error: ipv4: MR table does not exist.
Dump terminated

commit ae677bbb4441 introduced the dump_all_families variable, which
gets set when userspace requests a PF_UNSPEC dump. However, we can't
simply set the family to PF_UNSPEC in rtnetlink_rcv_msg in the
fallback case to get dump_all_families == true, because some messages
types (for example RTM_GETRULE and RTM_GETNEIGH) only register the
PF_UNSPEC handler and use the family to filter in the kernel what is
dumped to userspace. We would then export more entries, that userspace
would have to filter. iproute does that, but other programs may not.

Instead, this patch removes dump_all_families and updates the
RTM_GETROUTE handlers to check if the family that is being dumped is
their own. When it's not, which covers both the intentional PF_UNSPEC
dumps (as dump_all_families did) and the fallback case, ignore the
missing table id error.

Fixes: cb167893f41e ("net: Plumb support for filtering ipv4 and ipv6 multicast route dumps")
Signed-off-by: Sabrina Dubroca
Reviewed-by: David Ahern
Signed-off-by: David S. Miller
Signed-off-by: Greg Kroah-Hartman

net: Properly update v4 routes with v6 nexthop

2019-09-05T10:35:58+00:00

When creating a v4 route that uses a v6 nexthop from a nexthop group.
Allow the kernel to properly send the nexthop as v6 via the RTA_VIA
attribute.

Broken behavior:

$ ip nexthop add via fe80::9 dev eth0
$ ip nexthop show
id 1 via fe80::9 dev eth0 scope link
$ ip route add 4.5.6.7/32 nhid 1
$ ip route show
default via 10.0.2.2 dev eth0
4.5.6.7 nhid 1 via 254.128.0.0 dev eth0
10.0.2.0/24 dev eth0 proto kernel scope link src 10.0.2.15
$

Fixed behavior:

$ ip nexthop add via fe80::9 dev eth0
$ ip nexthop show
id 1 via fe80::9 dev eth0 scope link
$ ip route add 4.5.6.7/32 nhid 1
$ ip route show
default via 10.0.2.2 dev eth0
4.5.6.7 nhid 1 via inet6 fe80::9 dev eth0
10.0.2.0/24 dev eth0 proto kernel scope link src 10.0.2.15
$

v2, v3: Addresses code review comments from David Ahern

Fixes: dcb1ecb50edf (“ipv4: Prepare for fib6_nh from a nexthop object”)
Signed-off-by: Donald Sharp 
Reviewed-by: David Ahern 
Signed-off-by: David S. Miller

fib_frontend, ip6_fib: Select routes or exceptions dump from RTM_F_CLONED

2019-06-24T17:18:48+00:00

The following patches add back the ability to dump IPv4 and IPv6 exception
routes, and we need to allow selection of regular routes or exceptions.

Use RTM_F_CLONED as filter to decide whether to dump routes or exceptions:
iproute2 passes it in dump requests (except for IPv6 cache flush requests,
this will be fixed in iproute2) and this used to work as long as
exceptions were stored directly in the FIB, for both IPv4 and IPv6.

Caveat: if strict checking is not requested (that is, if the dump request
doesn't go through ip_valid_fib_dump_req()), we can't filter on protocol,
tables or route types.

In this case, filtering on RTM_F_CLONED would be inconsistent: we would
fix 'ip route list cache' by returning exception routes and at the same
time introduce another bug in case another selector is present, e.g. on
'ip route list cache table main' we would return all exception routes,
without filtering on tables.

Keep this consistent by applying no filters at all, and dumping both
routes and exceptions, if strict checking is not requested. iproute2
currently filters results anyway, and no unwanted results will be
presented to the user. The kernel will just dump more data than needed.

v7: No changes

v6: Rebase onto net-next, no changes

v5: New patch: add dump_routes and dump_exceptions flags in filter and
    simply clear the unwanted one if strict checking is enabled, don't
    ignore NLM_F_MATCH and don't set filter_set if NLM_F_MATCH is set.
    Skip filtering altogether if no strict checking is requested:
    selecting routes or exceptions only would be inconsistent with the
    fact we can't filter on tables.

Signed-off-by: Stefano Brivio 
Reviewed-by: David Ahern 
Signed-off-by: David S. Miller

ipv4: Allow routes to use nexthop objects

2019-06-10T17:44:56+00:00

Add support for RTA_NH_ID attribute to allow a user to specify a
nexthop id to use with a route. fc_nh_id is added to fib_config to
hold the value passed in the RTA_NH_ID attribute. If a nexthop id
is given, the gateway, device, encap and multipath attributes can
not be set.

Update fib_nh_match to check ids on a route delete.

Signed-off-by: David Ahern 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2019-06-07T18:00:14+00:00

Some ISDN files that got removed in net-next had some changes
done in mainline, take the removals.

Signed-off-by: David S. Miller

ipv4: Plumb support for nexthop object in a fib_info

2019-06-05T02:26:49+00:00

Add 'struct nexthop' and nh_list list_head to fib_info. nh_list is the
fib_info side of the nexthop <-> fib_info relationship.

Add fi_list list_head to 'struct nexthop' to track fib_info entries
using a nexthop instance. Add __remove_nexthop_fib and add it to
__remove_nexthop to walk the new list_head and mark those fib entries
as dead when the nexthop is deleted.

Add a few nexthop helpers for use when a nexthop is added to fib_info:
- nexthop_cmp to determine if 2 nexthops are the same
- nexthop_path_fib_result to select a path for a multipath
  'struct nexthop'
- nexthop_fib_nhc to select a specific fib_nh_common within a
  multipath 'struct nexthop'

Update existing fib_info_nhc to use nexthop_fib_nhc if a fib_info uses
a 'struct nexthop', and mark fib_info_nh as only used for the non-nexthop
case.

Update the fib_info functions to check for fi->nh and take a different
path as needed:
- free_fib_info_rcu - put the nexthop object reference
- fib_release_info - remove the fib_info from the nexthop's fi_list
- nh_comp - use nexthop_cmp when either fib_info references a nexthop
  object
- fib_info_hashfn - use the nexthop id for the hashing vs the oif of
  each fib_nh in a fib_info
- fib_nlmsg_size - add space for the RTA_NH_ID attribute
- fib_create_info - verify nexthop reference can be taken, verify
  nexthop spec is valid for fib entry, and add fib_info to fi_list for
  a nexthop
- fib_select_multipath - use the new nexthop_path_fib_result to select a
  path when nexthop objects are used
- fib_table_lookup - if the 'struct nexthop' is a blackhole nexthop, treat
  it the same as a fib entry using 'blackhole'

The bulk of the changes are in fib_semantics.c and most of that is
moving the existing change_nexthops into an else branch.

Update the nexthop code to walk fi_list on a nexthop deleted to remove
fib entries referencing it.

Signed-off-by: David Ahern 
Signed-off-by: David S. Miller

ipv4: Prepare for fib6_nh from a nexthop object

2019-06-05T02:26:49+00:00

Convert more IPv4 code to use fib_nh_common over fib_nh to enable routes
to use a fib6_nh based nexthop. In the end, only code not using a
nexthop object in a fib_info should directly access fib_nh in a fib_info
without checking the famiy and going through fib_nh_common. Those
functions will be marked when it is not directly evident.

Signed-off-by: David Ahern 
Signed-off-by: David S. Miller