The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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: dcb1ecb50e (“ipv4: Prepare for fib6_nh from a nexthop object”)
Signed-off-by: Donald Sharp <sharpd@cumulusnetworks.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Donald reported this sequence:
ip next add id 1 blackhole
ip next add id 2 blackhole
ip ro add 1.1.1.1/32 nhid 1
ip ro add 1.1.1.2/32 nhid 2
would cause a crash. Backtrace is:
[ 151.302790] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[ 151.304043] CPU: 1 PID: 277 Comm: ip Not tainted 5.3.0-rc5+ #37
[ 151.305078] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.1-1 04/01/2014
[ 151.306526] RIP: 0010:fib_add_nexthop+0x8b/0x2aa
[ 151.307343] Code: 35 f7 81 48 8d 14 01 c7 02 f1 f1 f1 f1 c7 42 04 01 f4 f4 f4 48 89 f2 48 c1 ea 03 65 48 8b 0c 25 28 00 00 00 48 89 4d d0 31 c9 <80> 3c 02 00 74 08 48 89 f7 e8 1a e8 53 ff be 08 00 00 00 4c 89 e7
[ 151.310549] RSP: 0018:ffff888116c27340 EFLAGS: 00010246
[ 151.311469] RAX: dffffc0000000000 RBX: ffff8881154ece00 RCX: 0000000000000000
[ 151.312713] RDX: 0000000000000004 RSI: 0000000000000020 RDI: ffff888115649b40
[ 151.313968] RBP: ffff888116c273d8 R08: ffffed10221e3757 R09: ffff888110f1bab8
[ 151.315212] R10: 0000000000000001 R11: ffff888110f1bab3 R12: ffff888115649b40
[ 151.316456] R13: 0000000000000020 R14: ffff888116c273b0 R15: ffff888115649b40
[ 151.317707] FS: 00007f60b4d8d800(0000) GS:ffff88811ac00000(0000) knlGS:0000000000000000
[ 151.319113] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 151.320119] CR2: 0000555671ffdc00 CR3: 00000001136ba005 CR4: 0000000000020ee0
[ 151.321367] Call Trace:
[ 151.321820] ? fib_nexthop_info+0x635/0x635
[ 151.322572] fib_dump_info+0xaa4/0xde0
[ 151.323247] ? fib_create_info+0x2431/0x2431
[ 151.324008] ? napi_alloc_frag+0x2a/0x2a
[ 151.324711] rtmsg_fib+0x2c4/0x3be
[ 151.325339] fib_table_insert+0xe2f/0xeee
...
fib_dump_info incorrectly has nhs = 0 for blackhole nexthops, so it
believes the nexthop object is a multipath group (nhs != 1) and ends
up down the nexthop_mpath_fill_node() path which is wrong for a
blackhole.
The blackhole check in nexthop_num_path is leftover from early days
of the blackhole implementation which did not initialize the device.
In the end the design was simpler (fewer special case checks) to set
the device to loopback in nh_info, so the check in nexthop_num_path
should have been removed.
Fixes: 430a049190 ("nexthop: Add support for nexthop groups")
Reported-by: Donald Sharp <sharpd@cumulusnetworks.com>
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
IPv6 has traditionally had a single fib6_nh per fib6_info. With
nexthops we can have multiple fib6_nh associated with a fib6_info.
Add a nexthop helper to invoke a callback for each fib6_nh in a
'struct nexthop'. If the callback returns non-0, the loop is
stopped and the return value passed to the caller.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The nhg->nh_entries[] array is allocated in nexthop_grp_alloc() and it
has nhg->num_nh elements so this check should be >= instead of >.
Fixes: 430a049190 ("nexthop: Add support for nexthop groups")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add struct nexthop and nh_list list_head to fib6_info. nh_list is the
fib6_info side of the nexthop <-> fib_info relationship. Since a fib6_info
referencing a nexthop object can not have 'sibling' entries (the old way
of doing multipath routes), the nh_list is a union with fib6_siblings.
Add f6i_list list_head to 'struct nexthop' to track fib6_info entries
using a nexthop instance. Update __remove_nexthop_fib to walk f6_list
and delete fib entries using the nexthop.
Add a few nexthop helpers for use when a nexthop is added to fib6_info:
- nexthop_fib6_nh - return first fib6_nh in a nexthop object
- fib6_info_nh_dev moved to nexthop.h and updated to use nexthop_fib6_nh
if the fib6_info references a nexthop object
- nexthop_path_fib6_result - similar to ipv4, select a path within a
multipath nexthop object. If the nexthop is a blackhole, set
fib6_result type to RTN_BLACKHOLE, and set the REJECT flag
Update the fib6_info references to check for nh and take a different path
as needed:
- rt6_qualify_for_ecmp - if a fib entry uses a nexthop object it can NOT
be coalesced with other fib entries into a multipath route
- rt6_duplicate_nexthop - use nexthop_cmp if either fib6_info references
a nexthop
- addrconf (host routes), RA's and info entries (anything configured via
ndisc) does not use nexthop objects
- fib6_info_destroy_rcu - put reference to nexthop object
- fib6_purge_rt - drop fib6_info from f6i_list
- fib6_select_path - update to use the new nexthop_path_fib6_result when
fib entry uses a nexthop object
- rt6_device_match - update to catch use of nexthop object as a blackhole
and set fib6_type and flags.
- ip6_route_info_create - don't add space for fib6_nh if fib entry is
going to reference a nexthop object, take a reference to nexthop object,
disallow use of source routing
- rt6_nlmsg_size - add space for RTA_NH_ID
- add rt6_fill_node_nexthop to add nexthop data on a dump
As with ipv4, most of the changes push existing code into the else branch
of whether the fib entry uses a nexthop object.
Update the nexthop code to walk f6i_list on a nexthop deleted to remove
fib entries referencing it.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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 <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use helpers to access fib_nh and fib_nhs fields of a fib_info. Drop the
fib_dev macro which is an alias for the first nexthop. Replacements:
fi->fib_dev --> fib_info_nh(fi, 0)->fib_nh_dev
fi->fib_nh --> fib_info_nh(fi, 0)
fi->fib_nh[i] --> fib_info_nh(fi, i)
fi->fib_nhs --> fib_info_num_path(fi)
where fib_info_nh(fi, i) returns fi->fib_nh[nhsel] and fib_info_num_path
returns fi->fib_nhs.
Move the existing fib_info_nhc to nexthop.h and define the new ones
there. A later patch adds a check if a fib_info uses a nexthop object,
and defining the helpers in nexthop.h avoid circular header
dependencies.
After this all remaining open coded references to fi->fib_nhs and
fi->fib_nh are in:
- fib_create_info and helpers used to lookup an existing fib_info
entry, and
- the netdev event functions fib_sync_down_dev and fib_sync_up.
The latter two will not be reused for nexthops, and the fib_create_info
will be updated to handle a nexthop in a fib_info.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Allow the creation of nexthop groups which reference other nexthop
objects to create multipath routes:
+--------------+
+------------+ +--------------+ |
| nh nh_grp --->| nh_grp_entry |-+
+------------+ +---------|----+
^ | | +------------+
+----------------+ +--->| nh, weight |
nh_parent +------------+
A group entry points to a nexthop with a weight for that hop within the
group. The nexthop has a list_head, grp_list, for tracking which groups
it is a member of and the group entry has a reference back to the parent.
The grp_list is used when a nexthop is deleted - to efficiently remove
it from groups using it.
If a nexthop group spec is given, no other attributes can be set. Each
nexthop id in a group spec must already exist.
Similar to single nexthops, the specification of a nexthop group can be
updated so that data is managed with rcu locking.
Add path selection function to account for multiple paths and add
ipv{4,6}_good_nh helpers to know that if a neighbor entry exists it is
in a good state.
Update NETDEV event handling to rebalance multipath nexthop groups if
a nexthop is deleted due to a link event (down or unregister).
When a nexthop is removed any groups using it are updated. Groups using a
nexthop a tracked via a grp_list.
Nexthop dumps can be limited to groups only by adding NHA_GROUPS to the
request.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add support for NHA_ENCAP and NHA_ENCAP_TYPE. Leverages the existing code
for lwtunnel within fib_nh_common, so the only change needed is handling
the attributes in the nexthop code.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Handle IPv6 gateway in a nexthop spec. If nh_family is set to AF_INET6,
NHA_GATEWAY is expected to be an IPv6 address. Add ipv6 option to gw in
nh_config to hold the address, add fib6_nh to nh_info to leverage the
ipv6 initialization and cleanup code. Update nh_fill_node to dump the v6
address.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add support for IPv4 nexthops. If nh_family is set to AF_INET, then
NHA_GATEWAY is expected to be an IPv4 address.
Register for netdev events to be notified of admin up/down changes as
well as deletes. A hash table is used to track nexthop per devices to
quickly convert device events to the affected nexthops.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Barebones start point for nexthops. Implementation for RTM commands,
notifications, management of rbtree for holding nexthops by id, and
kernel side data structures for nexthops and nexthop config.
Nexthops are maintained in an rbtree sorted by id. Similar to routes,
nexthops are configured per namespace using netns_nexthop struct added
to struct net.
Nexthop notifications are sent when a nexthop is added or deleted,
but NOT if the delete is due to a device event or network namespace
teardown (which also involves device events). Applications are
expected to use the device down event to flush nexthops and any
routes used by the nexthops.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The header contains rtnh_ macros so rename the file accordingly.
Allows a later patch to use the nexthop.h name for the new
nexthop code.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
syzbot reported :
BUG: KMSAN: uninit-value in rtnh_ok include/net/nexthop.h:11 [inline]
BUG: KMSAN: uninit-value in fib_count_nexthops net/ipv4/fib_semantics.c:469 [inline]
BUG: KMSAN: uninit-value in fib_create_info+0x554/0x8d20 net/ipv4/fib_semantics.c:1091
@remaining is an integer, coming from user space.
If it is negative we want rtnh_ok() to return false.
Fixes: 4e902c5741 ("[IPv4]: FIB configuration using struct fib_config")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Introduces struct fib_config replacing the ugly struct kern_rta
prone to ordering issues. Avoids creating faked netlink messages
for auto generated routes or requests via ioctl.
A new interface net/nexthop.h is added to help navigate through
nexthop configuration arrays.
A new struct nl_info will be used to carry the necessary netlink
information to be used for notifications later on.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Gustavo A. R. Silva