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  1. 03 Jun, 2018 3 commits
  3. 02 Jun, 2018 9 commits
  5. 30 May, 2018 7 commits
  7. 29 May, 2018 4 commits
  9. 28 May, 2018 10 commits
    • Daniel Borkmann's avatar
      Merge branch 'bpf-sendmsg-hook' · f198222f
      Daniel Borkmann authored 
      Andrey Ignatov says:

====================
v3 -> v4:
* handle static key correctly for CONFIG_CGROUP_BPF=n.

v2 -> v3:
* place BPF logic under static key in udp_sendmsg, udpv6_sendmsg;
* rebase.

v1 -> v2:
* return ENOTSUPP if bpf_prog rewrote IPv6-only with IPv4-mapped IPv6;
* add test for IPv4-mapped IPv6 use-case;
* fix build for CONFIG_CGROUP_BPF=n;
* rebase.

This path set adds BPF hooks for sys_sendmsg similar to existing hooks for
sys_bind and sys_connect.

Hooks allow to override source IP (including the case when it's set via
cmsg(3)) and destination IP:port for unconnected UDP (slow path). TCP and
connected UDP (fast path) are not affected. This makes UDP support
complete: connected UDP is handled by sys_connect hooks, unconnected by
sys_sendmsg ones.

Similar to sys_connect hooks, sys_sendmsg ones can be used to make system
calls such as sendmsg(2) and sendto(2) return EPERM.

Please see patch 0002 for more details.
====================
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      f198222f
    • Andrey Ignatov's avatar
      selftests/bpf: Selftest for sys_sendmsg hooks · 04b6ab73
      Andrey Ignatov authored 
      Add selftest for BPF_CGROUP_UDP4_SENDMSG and BPF_CGROUP_UDP6_SENDMSG
attach types.

Try to sendmsg(2) to specific IP:port and test that:
* source IP is overridden as expected.
* remote IP:port pair is overridden as expected;

Both UDPv4 and UDPv6 are tested.

Output:
  # test_sock_addr.sh 2>/dev/null
  Wait for testing IPv4/IPv6 to become available ... OK
  ... pre-existing test-cases skipped ...
  Test case: sendmsg4: load prog with wrong expected attach type .. [PASS]
  Test case: sendmsg4: attach prog with wrong attach type .. [PASS]
  Test case: sendmsg4: rewrite IP & port (asm) .. [PASS]
  Test case: sendmsg4: rewrite IP & port (C) .. [PASS]
  Test case: sendmsg4: deny call .. [PASS]
  Test case: sendmsg6: load prog with wrong expected attach type .. [PASS]
  Test case: sendmsg6: attach prog with wrong attach type .. [PASS]
  Test case: sendmsg6: rewrite IP & port (asm) .. [PASS]
  Test case: sendmsg6: rewrite IP & port (C) .. [PASS]
  Test case: sendmsg6: IPv4-mapped IPv6 .. [PASS]
  Test case: sendmsg6: deny call .. [PASS]
  Summary: 27 PASSED, 0 FAILED
Signed-off-by: default avatarAndrey Ignatov <rdna@fb.com>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      04b6ab73
    • Andrey Ignatov's avatar
      selftests/bpf: Prepare test_sock_addr for extension · 9be71aa6
      Andrey Ignatov authored 
      test_sock_addr was not easy to extend since it was focused on sys_bind
and sys_connect quite a bit.

Reorganized it so that it'll be easier to cover new test-cases for
`BPF_PROG_TYPE_CGROUP_SOCK_ADDR`:

- decouple test-cases so that only one BPF prog is tested at a time;

- check programmatically that local IP:port for sys_bind, source IP and
  destination IP:port for sys_connect are rewritten property by tested
  BPF programs.

The output of new version:
  # test_sock_addr.sh 2>/dev/null
  Wait for testing IPv4/IPv6 to become available ... OK
  Test case: bind4: load prog with wrong expected attach type .. [PASS]
  Test case: bind4: attach prog with wrong attach type .. [PASS]
  Test case: bind4: rewrite IP & TCP port in .. [PASS]
  Test case: bind4: rewrite IP & UDP port in .. [PASS]
  Test case: bind6: load prog with wrong expected attach type .. [PASS]
  Test case: bind6: attach prog with wrong attach type .. [PASS]
  Test case: bind6: rewrite IP & TCP port in .. [PASS]
  Test case: bind6: rewrite IP & UDP port in .. [PASS]
  Test case: connect4: load prog with wrong expected attach type .. [PASS]
  Test case: connect4: attach prog with wrong attach type .. [PASS]
  Test case: connect4: rewrite IP & TCP port .. [PASS]
  Test case: connect4: rewrite IP & UDP port .. [PASS]
  Test case: connect6: load prog with wrong expected attach type .. [PASS]
  Test case: connect6: attach prog with wrong attach type .. [PASS]
  Test case: connect6: rewrite IP & TCP port .. [PASS]
  Test case: connect6: rewrite IP & UDP port .. [PASS]
  Summary: 16 PASSED, 0 FAILED

(stderr contains errors from libbpf when testing load/attach with
invalid arguments)
Signed-off-by: default avatarAndrey Ignatov <rdna@fb.com>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      9be71aa6
    • Andrey Ignatov's avatar
      libbpf: Support guessing sendmsg{4,6} progs · 72481f39
      Andrey Ignatov authored 
      libbpf can guess prog type and expected attach type based on section
name. Add hints for "cgroup/sendmsg4" and "cgroup/sendmsg6" section
names.
Signed-off-by: default avatarAndrey Ignatov <rdna@fb.com>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      72481f39
    • Andrey Ignatov's avatar
      bpf: Sync bpf.h to tools/ · 3024cf82
      Andrey Ignatov authored 
      Sync new `BPF_CGROUP_UDP4_SENDMSG` and `BPF_CGROUP_UDP6_SENDMSG`
attach types to tools/.
Signed-off-by: default avatarAndrey Ignatov <rdna@fb.com>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      3024cf82
    • Andrey Ignatov's avatar
      bpf: Hooks for sys_sendmsg · 1cedee13
      Andrey Ignatov authored 
      In addition to already existing BPF hooks for sys_bind and sys_connect,
the patch provides new hooks for sys_sendmsg.

It leverages existing BPF program type `BPF_PROG_TYPE_CGROUP_SOCK_ADDR`
that provides access to socket itlself (properties like family, type,
protocol) and user-passed `struct sockaddr *` so that BPF program can
override destination IP and port for system calls such as sendto(2) or
sendmsg(2) and/or assign source IP to the socket.

The hooks are implemented as two new attach types:
`BPF_CGROUP_UDP4_SENDMSG` and `BPF_CGROUP_UDP6_SENDMSG` for UDPv4 and
UDPv6 correspondingly.

UDPv4 and UDPv6 separate attach types for same reason as sys_bind and
sys_connect hooks, i.e. to prevent reading from / writing to e.g.
user_ip6 fields when user passes sockaddr_in since it'd be out-of-bound.

The difference with already existing hooks is sys_sendmsg are
implemented only for unconnected UDP.

For TCP it doesn't make sense to change user-provided `struct sockaddr *`
at sendto(2)/sendmsg(2) time since socket either was already connected
and has source/destination set or wasn't connected and call to
sendto(2)/sendmsg(2) would lead to ENOTCONN anyway.

Connected UDP is already handled by sys_connect hooks that can override
source/destination at connect time and use fast-path later, i.e. these
hooks don't affect UDP fast-path.

Rewriting source IP is implemented differently than that in sys_connect
hooks. When sys_sendmsg is used with unconnected UDP it doesn't work to
just bind socket to desired local IP address since source IP can be set
on per-packet basis by using ancillary data (cmsg(3)). So no matter if
socket is bound or not, source IP has to be rewritten on every call to
sys_sendmsg.

To do so two new fields are added to UAPI `struct bpf_sock_addr`;
* `msg_src_ip4` to set source IPv4 for UDPv4;
* `msg_src_ip6` to set source IPv6 for UDPv6.
Signed-off-by: default avatarAndrey Ignatov <rdna@fb.com>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      1cedee13
    • Andrey Ignatov's avatar
      bpf: Define cgroup_bpf_enabled for CONFIG_CGROUP_BPF=n · 13193b0f
      Andrey Ignatov authored 
      Static key is used to enable/disable cgroup-bpf related code paths at
run time.

Though it's not defined when cgroup-bpf is disabled at compile time,
i.e. CONFIG_CGROUP_BPF=n, and if some code wants to use it, it has to do
this:

	#ifdef CONFIG_CGROUP_BPF
		if (cgroup_bpf_enabled) {
			/* ... some work ... */
		}
	#endif

This code can be simplified by setting cgroup_bpf_enabled to 0 for
CONFIG_CGROUP_BPF=n case:

	if (cgroup_bpf_enabled) {
		/* ... some work ... */
	}

And it aligns well with existing BPF_CGROUP_RUN_PROG_* macros that
defined for both states of CONFIG_CGROUP_BPF.
Signed-off-by: default avatarAndrey Ignatov <rdna@fb.com>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      13193b0f
    • Mathieu Xhonneux's avatar
      selftests/bpf: missing headers test_lwt_seg6local · 3b296633
      Mathieu Xhonneux authored 
      Previous patch "selftests/bpf: test for seg6local End.BPF action" lacks
some UAPI headers in tools/.

clang -I. -I./include/uapi -I../../../include/uapi -idirafter
/usr/local/include -idirafter
/data/users/yhs/work/llvm/build/install/lib/clang/7.0.0/include
-idirafter /usr/include -Wno-compare-distinct-pointer-types \
         -O2 -target bpf -emit-llvm -c test_lwt_seg6local.c -o - |      \
llc -march=bpf -mcpu=generic  -filetype=obj -o
[...]/net-next/tools/testing/selftests/bpf/test_lwt_seg6local.o
test_lwt_seg6local.c:4:10: fatal error: 'linux/seg6_local.h' file not found
         ^~~~~~~~~~~~~~~~~~~~
1 error generated.
make: Leaving directory
`/data/users/yhs/work/net-next/tools/testing/selftests/bpf'

v2: moving the headers to tools/include/uapi/.
Reported-by: default avatarY Song <ys114321@gmail.com>
Signed-off-by: default avatarMathieu Xhonneux <m.xhonneux@gmail.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      3b296633
    • Arnd Bergmann's avatar
      bpf: avoid -Wmaybe-uninitialized warning · dc3b8ae9
      Arnd Bergmann authored 
      The stack_map_get_build_id_offset() function is too long for gcc to track
whether 'work' may or may not be initialized at the end of it, leading
to a false-positive warning:

kernel/bpf/stackmap.c: In function 'stack_map_get_build_id_offset':
kernel/bpf/stackmap.c:334:13: error: 'work' may be used uninitialized in this function [-Werror=maybe-uninitialized]

This removes the 'in_nmi_ctx' flag and uses the state of that variable
itself to see if it got initialized.

Fixes: bae77c5e ("bpf: enable stackmap with build_id in nmi context")
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Acked-by: default avatarSong Liu <songliubraving@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      dc3b8ae9
    • Arnd Bergmann's avatar
      bpf: btf: avoid -Wreturn-type warning · 53c8036c
      Arnd Bergmann authored 
      gcc warns about a noreturn function possibly returning in
some configurations:

kernel/bpf/btf.c: In function 'env_type_is_resolve_sink':
kernel/bpf/btf.c:729:1: error: control reaches end of non-void function [-Werror=return-type]

Using BUG() instead of BUG_ON() avoids that warning and otherwise
does the exact same thing.

Fixes: eb3f595d ("bpf: btf: Validate type reference")
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Acked-by: default avatarSong Liu <songliubraving@fb.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
      53c8036c
  11. 27 May, 2018 1 commit
  13. 26 May, 2018 6 commits
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