Commit Graph

24 Commits

Author SHA1 Message Date
Kees Cook 896880ff30 bpf: Replace bpf_lpm_trie_key 0-length array with flexible array
Replace deprecated 0-length array in struct bpf_lpm_trie_key with
flexible array. Found with GCC 13:

../kernel/bpf/lpm_trie.c:207:51: warning: array subscript i is outside array bounds of 'const __u8[0]' {aka 'const unsigned char[]'} [-Warray-bounds=]
  207 |                                        *(__be16 *)&key->data[i]);
      |                                                   ^~~~~~~~~~~~~
../include/uapi/linux/swab.h:102:54: note: in definition of macro '__swab16'
  102 | #define __swab16(x) (__u16)__builtin_bswap16((__u16)(x))
      |                                                      ^
../include/linux/byteorder/generic.h:97:21: note: in expansion of macro '__be16_to_cpu'
   97 | #define be16_to_cpu __be16_to_cpu
      |                     ^~~~~~~~~~~~~
../kernel/bpf/lpm_trie.c:206:28: note: in expansion of macro 'be16_to_cpu'
  206 |                 u16 diff = be16_to_cpu(*(__be16 *)&node->data[i]
^
      |                            ^~~~~~~~~~~
In file included from ../include/linux/bpf.h:7:
../include/uapi/linux/bpf.h:82:17: note: while referencing 'data'
   82 |         __u8    data[0];        /* Arbitrary size */
      |                 ^~~~

And found at run-time under CONFIG_FORTIFY_SOURCE:

  UBSAN: array-index-out-of-bounds in kernel/bpf/lpm_trie.c:218:49
  index 0 is out of range for type '__u8 [*]'

Changing struct bpf_lpm_trie_key is difficult since has been used by
userspace. For example, in Cilium:

	struct egress_gw_policy_key {
	        struct bpf_lpm_trie_key lpm_key;
	        __u32 saddr;
	        __u32 daddr;
	};

While direct references to the "data" member haven't been found, there
are static initializers what include the final member. For example,
the "{}" here:

        struct egress_gw_policy_key in_key = {
                .lpm_key = { 32 + 24, {} },
                .saddr   = CLIENT_IP,
                .daddr   = EXTERNAL_SVC_IP & 0Xffffff,
        };

To avoid the build time and run time warnings seen with a 0-sized
trailing array for struct bpf_lpm_trie_key, introduce a new struct
that correctly uses a flexible array for the trailing bytes,
struct bpf_lpm_trie_key_u8. As part of this, include the "header"
portion (which is just the "prefixlen" member), so it can be used
by anything building a bpf_lpr_trie_key that has trailing members that
aren't a u8 flexible array (like the self-test[1]), which is named
struct bpf_lpm_trie_key_hdr.

Unfortunately, C++ refuses to parse the __struct_group() helper, so
it is not possible to define struct bpf_lpm_trie_key_hdr directly in
struct bpf_lpm_trie_key_u8, so we must open-code the union directly.

Adjust the kernel code to use struct bpf_lpm_trie_key_u8 through-out,
and for the selftest to use struct bpf_lpm_trie_key_hdr. Add a comment
to the UAPI header directing folks to the two new options.

Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Closes: https://paste.debian.net/hidden/ca500597/
Link: https://lore.kernel.org/all/202206281009.4332AA33@keescook/ [1]
Link: https://lore.kernel.org/bpf/20240222155612.it.533-kees@kernel.org
2024-02-29 22:52:43 +01:00
Rong Tao 19a2bdbaad samples/bpf: Fix wrong allocation size in xdp_router_ipv4_user
prefix_key->data allocates three bytes using alloca(), but four bytes are
actually accessed in the program.

Signed-off-by: Rong Tao <rongtao@cestc.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/tencent_F9E2E81922B0C181D05B96DAE5AB0ACE6B06@qq.com
2022-11-25 00:21:29 +01:00
Deming Wang b59cc7fcba samples/bpf: Fix typo in xdp_router_ipv4 sample
Fix typo in xdp_router_ipv4 sample.

Signed-off-by: Deming Wang <wangdeming@inspur.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220927192527.8722-1-wangdeming@inspur.com
2022-09-30 15:04:23 -07:00
Yafang Shao b25acdafd3 samples/bpf: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK
We have switched to memcg-based memory accouting and thus the rlimit is
not needed any more. LIBBPF_STRICT_AUTO_RLIMIT_MEMLOCK was introduced in
libbpf for backward compatibility, so we can use it instead now.

This patch also removes the useless header sys/resource.h from many files
in samples/bpf.

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220409125958.92629-2-laoar.shao@gmail.com
2022-04-10 20:17:15 -07:00
Lorenzo Bianconi 587323cf6a samples, bpf: Move routes monitor in xdp_router_ipv4 in a dedicated thread
In order to not miss any netlink message from the kernel, move routes
monitor to a dedicated thread.

Fixes: 85bf1f5169 ("samples: bpf: Convert xdp_router_ipv4 to XDP samples helper")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/e364b817c69ded73be24b677ab47a157f7c21b64.1649167911.git.lorenzo@kernel.org
2022-04-08 22:10:57 +02:00
Lorenzo Bianconi 85bf1f5169 samples: bpf: Convert xdp_router_ipv4 to XDP samples helper
Rely on the libbpf skeleton facility and other utilities provided by XDP
sample helpers in xdp_router_ipv4 sample.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/7f4d98ee2c13c04d5eb924eebf79ced32fee8418.1647414711.git.lorenzo@kernel.org
2022-04-03 17:12:09 -07:00
Andrii Nakryiko 1e4edb6d8c samples/bpf: Get rid of bpf_prog_load_xattr() use
Remove all the remaining uses of deprecated bpf_prog_load_xattr() API.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20220202225916.3313522-7-andrii@kernel.org
2022-02-03 16:32:25 +01:00
Andrii Nakryiko d4e34bfcbe samples/bpf: adapt samples/bpf to bpf_xdp_xxx() APIs
Use new bpf_xdp_*() APIs across all XDP-related BPF samples.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220120061422.2710637-5-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-01-20 21:22:02 -08:00
Gokul Sivakumar cf8980a362 samples: bpf: Convert ARP table network order fields into readable format
The ARP table that is dumped when the xdp_router_ipv4 process is launched
has the IP address & MAC address in non-readable network byte order format,
also the alignment is off when printing the table.

Address HwAddress
160000e0                1600005e0001
ff96a8c0                ffffffffffff
faffffef                faff7f5e0001
196a8c0		9607871293ea
fb0000e0                fb00005e0001
0               0
196a8c0		9607871293ea
ffff11ac                ffffffffffff
faffffef                faff7f5e0001
fb0000e0                fb00005e0001
160000e0                1600005e0001
160000e0                1600005e0001
faffffef                faff7f5e0001
fb0000e0                fb00005e0001
40011ac         40011ac4202

Fix this by converting the "Address" field from network byte order Hex into
dotted decimal notation IPv4 format and "HwAddress" field from network byte
order Hex into Colon separated Hex format. Also fix the aligntment of the
fields in the ARP table.

Address         HwAddress
224.0.0.22      01:00:5e:00:00:16
192.168.150.255 ff:ff:ff:ff:ff:ff
239.255.255.250 01:00:5e:7f:ff:fa
192.168.150.1	ea:93:12:87:07:96
224.0.0.251     01:00:5e:00:00:fb
0.0.0.0         00:00:00:00:00:00
192.168.150.1	ea:93:12:87:07:96
172.17.255.255  ff:ff:ff:ff:ff:ff
239.255.255.250 01:00:5e:7f:ff:fa
224.0.0.251     01:00:5e:00:00:fb
224.0.0.22      01:00:5e:00:00:16
224.0.0.22      01:00:5e:00:00:16
239.255.255.250 01:00:5e:7f:ff:fa
224.0.0.251     01:00:5e:00:00:fb
172.17.0.4      02:42:ac:11:00:04

Signed-off-by: Gokul Sivakumar <gokulkumar792@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210919080305.173588-2-gokulkumar792@gmail.com
2021-09-21 13:27:54 -07:00
Gokul Sivakumar f5c4e4191b samples: bpf: Convert route table network order fields into readable format
The route table that is dumped when the xdp_router_ipv4 process is launched
has the "Gateway" field in non-readable network byte order format, also the
alignment is off when printing the table.

Destination             Gateway         Genmask         Metric          Iface
  0.0.0.0               196a8c0         0               0               enp7s0
  0.0.0.0               196a8c0         0               0               wlp6s0
169.254.0.0             196a8c0         16              0               enp7s0
172.17.0.0                0             16              0               docker0
192.168.150.0             0             24              0               enp7s0
192.168.150.0             0             24              0               wlp6s0

Fix this by converting the "Gateway" field from network byte order Hex into
dotted decimal notation IPv4 format and "Genmask" from CIDR notation into
dotted decimal notation IPv4 format. Also fix the aligntment of the fields
in the route table.

Destination     Gateway         Genmask         Metric Iface
0.0.0.0         192.168.150.1   0.0.0.0         0      enp7s0
0.0.0.0         192.168.150.1   0.0.0.0         0      wlp6s0
169.254.0.0     192.168.150.1   255.255.0.0     0      enp7s0
172.17.0.0      0.0.0.0         255.255.0.0     0      docker0
192.168.150.0   0.0.0.0         255.255.255.0   0      enp7s0
192.168.150.0   0.0.0.0         255.255.255.0   0      wlp6s0

Signed-off-by: Gokul Sivakumar <gokulkumar792@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210919080305.173588-1-gokulkumar792@gmail.com
2021-09-21 13:27:54 -07:00
Roman Gushchin 5b0764b2d3 bpf: samples: Do not touch RLIMIT_MEMLOCK
Since bpf is not using rlimit memlock for the memory accounting
and control, do not change the limit in sample applications.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-35-guro@fb.com
2020-12-02 18:32:47 -08:00
Toke Høiland-Jørgensen 7cf245a37e samples/bpf: Use consistent include paths for libbpf
Fix all files in samples/bpf to include libbpf header files with the bpf/
prefix, to be consistent with external users of the library. Also ensure
that all includes of exported libbpf header files (those that are exported
on 'make install' of the library) use bracketed includes instead of quoted.

To make sure no new files are introduced that doesn't include the bpf/
prefix in its include, remove tools/lib/bpf from the include path entirely,
and use tools/lib instead.

Fixes: 6910d7d386 ("selftests/bpf: Ensure bpf_helper_defs.h are taken from selftests dir")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157952560911.1683545.8795966751309534150.stgit@toke.dk
2020-01-20 16:37:45 -08:00
Toke Høiland-Jørgensen d50ecc46d1 samples/bpf: Attach XDP programs in driver mode by default
When attaching XDP programs, userspace can set flags to request the attach
mode (generic/SKB mode, driver mode or hw offloaded mode). If no such flags
are requested, the kernel will attempt to attach in driver mode, and then
silently fall back to SKB mode if this fails.

The silent fallback is a major source of user confusion, as users will try
to load a program on a device without XDP support, and instead of an error
they will get the silent fallback behaviour, not notice, and then wonder
why performance is not what they were expecting.

In an attempt to combat this, let's switch all the samples to default to
explicitly requesting driver-mode attach. As part of this, ensure that all
the userspace utilities have a switch to enable SKB mode. For those that
have a switch to request driver mode, keep it but turn it into a no-op.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: David Ahern <dsahern@gmail.com>
Link: https://lore.kernel.org/bpf/20191216110742.364456-1-toke@redhat.com
2019-12-16 07:05:38 -08:00
David S. Miller dca73a65a6 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:

====================
pull-request: bpf-next 2019-06-19

The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) new SO_REUSEPORT_DETACH_BPF setsocktopt, from Martin.

2) BTF based map definition, from Andrii.

3) support bpf_map_lookup_elem for xskmap, from Jonathan.

4) bounded loops and scalar precision logic in the verifier, from Alexei.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-20 00:06:27 -04:00
Daniel T. Lee 4d18f6de6a samples: bpf: refactor header include path
Currently, header inclusion in each file is inconsistent.
For example, "libbpf.h" header is included as multiple ways.

    #include "bpf/libbpf.h"
    #include "libbpf.h"

Due to commit b552d33c80 ("samples/bpf: fix include path
in Makefile"), $(srctree)/tools/lib/bpf/ path had been included
during build, path "bpf/" in header isn't necessary anymore.

This commit removes path "bpf/" in header inclusion.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-06-18 00:28:36 +02:00
Thomas Gleixner 25763b3c86 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of version 2 of the gnu general public license as
  published by the free software foundation

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 107 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528171438.615055994@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:29:53 -07:00
Maciej Fijalkowski 3b7a8ec2de samples/bpf: Check the prog id before exiting
Check the program id within the signal handler on polling xdp samples
that were previously converted to libbpf usage. Avoid the situation of
unloading the program that was not attached by sample that is exiting.
Handle also the case where bpf_get_link_xdp_id didn't exit with an error
but the xdp program was not found on an interface.

Reported-by: Michal Papaj <michal.papaj@intel.com>
Reported-by: Jakub Spizewski <jakub.spizewski@intel.com>
Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-02-01 23:37:51 +01:00
Maciej Fijalkowski 743e568c15 samples/bpf: Add a "force" flag to XDP samples
Make xdp samples consistent with iproute2 behavior and set the
XDP_FLAGS_UPDATE_IF_NOEXIST by default when setting the xdp program on
interface. Provide an option for user to force the program loading,
which as a result will not include the mentioned flag in
bpf_set_link_xdp_fd call.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-02-01 23:37:51 +01:00
Maciej Fijalkowski 6a5457618f samples/bpf: Extend RLIMIT_MEMLOCK for xdp_{sample_pkts, router_ipv4}
There is a common problem with xdp samples that happens when user wants
to run a particular sample and some bpf program is already loaded. The
default 64kb RLIMIT_MEMLOCK resource limit will cause a following error
(assuming that xdp sample that is failing was converted to libbpf
usage):

libbpf: Error in bpf_object__probe_name():Operation not permitted(1).
Couldn't load basic 'r0 = 0' BPF program.
libbpf: failed to load object './xdp_sample_pkts_kern.o'

Fix it in xdp_sample_pkts and xdp_router_ipv4 by setting RLIMIT_MEMLOCK
to RLIM_INFINITY.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-02-01 23:37:51 +01:00
Maciej Fijalkowski bbaf6029c4 samples/bpf: Convert XDP samples to libbpf usage
Some of XDP samples that are attaching the bpf program to the interface
via libbpf's bpf_set_link_xdp_fd are still using the bpf_load.c for
loading and manipulating the ebpf program and maps. Convert them to do
this through libbpf usage and remove bpf_load from the picture.

While at it remove what looks like debug leftover in
xdp_redirect_map_user.c

In xdp_redirect_cpu, change the way that the program to be loaded onto
interface is chosen - user now needs to pass the program's section name
instead of the relative number. In case of typo print out the section
names to choose from.

Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-02-01 23:37:51 +01:00
Jakub Kicinski 2bf3e2ef42 samples: bpf: include bpf/bpf.h instead of local libbpf.h
There are two files in the tree called libbpf.h which is becoming
problematic.  Most samples don't actually need the local libbpf.h
they simply include it to get to bpf/bpf.h.  Include bpf/bpf.h
directly instead.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-05-14 22:52:10 -07:00
Eric Leblond b259c2ffd9 samples/bpf: use bpf_set_link_xdp_fd
Use bpf_set_link_xdp_fd instead of set_link_xdp_fd to remove some
code duplication and benefit of netlink ext ack errors message.

Signed-off-by: Eric Leblond <eric@regit.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-02-02 17:53:48 -08:00
Dan Carpenter fae45363ae xdp: sample: Missing curly braces in read_route()
The assert statement is supposed to be part of the else branch but the
curly braces were accidentally left off.

Fixes: 3e29cd0e65 ("xdp: Sample xdp program implementing ip forward")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-14 22:00:13 +09:00
Christina Jacob 3e29cd0e65 xdp: Sample xdp program implementing ip forward
Implements port to port forwarding with route table and arp table
lookup for ipv4 packets using bpf_redirect helper function and
lpm_trie  map.

Signed-off-by: Christina Jacob <Christina.Jacob@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-11-08 10:39:41 +09:00