Commit graph

256 commits

Author SHA1 Message Date
Quentin Deslandes
98e20e5e13 bpfilter: remove bpfilter
bpfilter was supposed to convert iptables filtering rules into
BPF programs on the fly, from the kernel, through a usermode
helper. The base code for the UMH was introduced in 2018, and
couple of attempts (2, 3) tried to introduce the BPF program
generate features but were abandoned.

bpfilter now sits in a kernel tree unused and unusable, occasionally
causing confusion amongst Linux users (4, 5).

As bpfilter is now developed in a dedicated repository on GitHub (6),
it was suggested a couple of times this year (LSFMM/BPF 2023,
LPC 2023) to remove the deprecated kernel part of the project. This
is the purpose of this patch.

[1]: https://lore.kernel.org/lkml/20180522022230.2492505-1-ast@kernel.org/
[2]: https://lore.kernel.org/bpf/20210829183608.2297877-1-me@ubique.spb.ru/#t
[3]: https://lore.kernel.org/lkml/20221224000402.476079-1-qde@naccy.de/
[4]: https://dxuuu.xyz/bpfilter.html
[5]: https://github.com/linuxkit/linuxkit/pull/3904
[6]: https://github.com/facebook/bpfilter

Signed-off-by: Quentin Deslandes <qde@naccy.de>
Link: https://lore.kernel.org/r/20231226130745.465988-1-qde@naccy.de
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-01-04 10:23:10 -08:00
Eric Dumazet
f5769faeec net: Namespace-ify sysctl_optmem_max
optmem_max being used in tx zerocopy,
we want to be able to control it on a netns basis.

Following patch changes two tests.

Tested:

oqq130:~# cat /proc/sys/net/core/optmem_max
131072
oqq130:~# echo 1000000 >/proc/sys/net/core/optmem_max
oqq130:~# cat /proc/sys/net/core/optmem_max
1000000
oqq130:~# unshare -n
oqq130:~# cat /proc/sys/net/core/optmem_max
131072
oqq130:~# exit
logout
oqq130:~# cat /proc/sys/net/core/optmem_max
1000000

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-12-15 11:01:27 +00:00
David Laight
d9f28735af Use READ/WRITE_ONCE() for IP local_port_range.
Commit 227b60f510 added a seqlock to ensure that the low and high
port numbers were always updated together.
This is overkill because the two 16bit port numbers can be held in
a u32 and read/written in a single instruction.

More recently 91d0b78c51 added support for finer per-socket limits.
The user-supplied value is 'high << 16 | low' but they are held
separately and the socket options protected by the socket lock.

Use a u32 containing 'high << 16 | low' for both the 'net' and 'sk'
fields and use READ_ONCE()/WRITE_ONCE() to ensure both values are
always updated together.

Change (the now trival) inet_get_local_port_range() to a static inline
to optimise the calling code.
(In particular avoiding returning integers by reference.)

Signed-off-by: David Laight <david.laight@aculab.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Acked-by: Mat Martineau <martineau@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/4e505d4198e946a8be03fb1b4c3072b0@AcuMS.aculab.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-12-08 10:44:42 -08:00
Yonghong Song
06497763c8 net: bpf: Use sockopt_lock_sock() in ip_sock_set_tos()
With latest sync from net-next tree, bpf-next has a bpf selftest failure:
  [root@arch-fb-vm1 bpf]# ./test_progs -t setget_sockopt
  ...
  [   76.194349] ============================================
  [   76.194682] WARNING: possible recursive locking detected
  [   76.195039] 6.6.0-rc7-g37884503df08-dirty #67 Tainted: G        W  OE
  [   76.195518] --------------------------------------------
  [   76.195852] new_name/154 is trying to acquire lock:
  [   76.196159] ffff8c3e06ad8d30 (sk_lock-AF_INET){+.+.}-{0:0}, at: ip_sock_set_tos+0x19/0x30
  [   76.196669]
  [   76.196669] but task is already holding lock:
  [   76.197028] ffff8c3e06ad8d30 (sk_lock-AF_INET){+.+.}-{0:0}, at: inet_listen+0x21/0x70
  [   76.197517]
  [   76.197517] other info that might help us debug this:
  [   76.197919]  Possible unsafe locking scenario:
  [   76.197919]
  [   76.198287]        CPU0
  [   76.198444]        ----
  [   76.198600]   lock(sk_lock-AF_INET);
  [   76.198831]   lock(sk_lock-AF_INET);
  [   76.199062]
  [   76.199062]  *** DEADLOCK ***
  [   76.199062]
  [   76.199420]  May be due to missing lock nesting notation
  [   76.199420]
  [   76.199879] 2 locks held by new_name/154:
  [   76.200131]  #0: ffff8c3e06ad8d30 (sk_lock-AF_INET){+.+.}-{0:0}, at: inet_listen+0x21/0x70
  [   76.200644]  #1: ffffffff90f96a40 (rcu_read_lock){....}-{1:2}, at: __cgroup_bpf_run_filter_sock_ops+0x55/0x290
  [   76.201268]
  [   76.201268] stack backtrace:
  [   76.201538] CPU: 4 PID: 154 Comm: new_name Tainted: G        W  OE      6.6.0-rc7-g37884503df08-dirty #67
  [   76.202134] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
  [   76.202699] Call Trace:
  [   76.202858]  <TASK>
  [   76.203002]  dump_stack_lvl+0x4b/0x80
  [   76.203239]  __lock_acquire+0x740/0x1ec0
  [   76.203503]  lock_acquire+0xc1/0x2a0
  [   76.203766]  ? ip_sock_set_tos+0x19/0x30
  [   76.204050]  ? sk_stream_write_space+0x12a/0x230
  [   76.204389]  ? lock_release+0xbe/0x260
  [   76.204661]  lock_sock_nested+0x32/0x80
  [   76.204942]  ? ip_sock_set_tos+0x19/0x30
  [   76.205208]  ip_sock_set_tos+0x19/0x30
  [   76.205452]  do_ip_setsockopt+0x4b3/0x1580
  [   76.205719]  __bpf_setsockopt+0x62/0xa0
  [   76.205963]  bpf_sock_ops_setsockopt+0x11/0x20
  [   76.206247]  bpf_prog_630217292049c96e_bpf_test_sockopt_int+0xbc/0x123
  [   76.206660]  bpf_prog_493685a3bae00bbd_bpf_test_ip_sockopt+0x49/0x4b
  [   76.207055]  bpf_prog_b0bcd27f269aeea0_skops_sockopt+0x44c/0xec7
  [   76.207437]  __cgroup_bpf_run_filter_sock_ops+0xda/0x290
  [   76.207829]  __inet_listen_sk+0x108/0x1b0
  [   76.208122]  inet_listen+0x48/0x70
  [   76.208373]  __sys_listen+0x74/0xb0
  [   76.208630]  __x64_sys_listen+0x16/0x20
  [   76.208911]  do_syscall_64+0x3f/0x90
  [   76.209174]  entry_SYSCALL_64_after_hwframe+0x6e/0xd8
  ...

Both ip_sock_set_tos() and inet_listen() calls lock_sock(sk) which
caused a dead lock.

To fix the issue, use sockopt_lock_sock() in ip_sock_set_tos()
instead. sockopt_lock_sock() will avoid lock_sock() if it is in bpf
context.

Fixes: 878d951c67 ("inet: lock the socket in ip_sock_set_tos()")
Suggested-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20231027182424.1444845-1-yonghong.song@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-10-27 15:41:28 -07:00
Eric Dumazet
878d951c67 inet: lock the socket in ip_sock_set_tos()
Christoph Paasch reported a panic in TCP stack [1]

Indeed, we should not call sk_dst_reset() without holding
the socket lock, as __sk_dst_get() callers do not all rely
on bare RCU.

[1]
BUG: kernel NULL pointer dereference, address: 0000000000000000
PGD 12bad6067 P4D 12bad6067 PUD 12bad5067 PMD 0
Oops: 0000 [#1] PREEMPT SMP
CPU: 1 PID: 2750 Comm: syz-executor.5 Not tainted 6.6.0-rc4-g7a5720a344e7 #49
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014
RIP: 0010:tcp_get_metrics+0x118/0x8f0 net/ipv4/tcp_metrics.c:321
Code: c7 44 24 70 02 00 8b 03 89 44 24 48 c7 44 24 4c 00 00 00 00 66 c7 44 24 58 02 00 66 ba 02 00 b1 01 89 4c 24 04 4c 89 7c 24 10 <49> 8b 0f 48 8b 89 50 05 00 00 48 89 4c 24 30 33 81 00 02 00 00 69
RSP: 0018:ffffc90000af79b8 EFLAGS: 00010293
RAX: 000000000100007f RBX: ffff88812ae8f500 RCX: ffff88812b5f8f01
RDX: 0000000000000002 RSI: ffffffff8300f080 RDI: 0000000000000002
RBP: 0000000000000002 R08: 0000000000000003 R09: ffffffff8205eca0
R10: 0000000000000002 R11: ffff88812b5f8f00 R12: ffff88812a9e0580
R13: 0000000000000000 R14: ffff88812ae8fbd2 R15: 0000000000000000
FS: 00007f70a006b640(0000) GS:ffff88813bd00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000012bad7003 CR4: 0000000000170ee0
Call Trace:
<TASK>
tcp_fastopen_cache_get+0x32/0x140 net/ipv4/tcp_metrics.c:567
tcp_fastopen_cookie_check+0x28/0x180 net/ipv4/tcp_fastopen.c:419
tcp_connect+0x9c8/0x12a0 net/ipv4/tcp_output.c:3839
tcp_v4_connect+0x645/0x6e0 net/ipv4/tcp_ipv4.c:323
__inet_stream_connect+0x120/0x590 net/ipv4/af_inet.c:676
tcp_sendmsg_fastopen+0x2d6/0x3a0 net/ipv4/tcp.c:1021
tcp_sendmsg_locked+0x1957/0x1b00 net/ipv4/tcp.c:1073
tcp_sendmsg+0x30/0x50 net/ipv4/tcp.c:1336
__sock_sendmsg+0x83/0xd0 net/socket.c:730
__sys_sendto+0x20a/0x2a0 net/socket.c:2194
__do_sys_sendto net/socket.c:2206 [inline]

Fixes: e08d0b3d17 ("inet: implement lockless IP_TOS")
Reported-by: Christoph Paasch <cpaasch@apple.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20231018090014.345158-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-10-19 13:13:13 +02:00
Eric Dumazet
0271592522 inet: implement lockless getsockopt(IP_MULTICAST_IF)
Add missing annotations to inet->mc_index and inet->mc_addr
to fix data-races.

getsockopt(IP_MULTICAST_IF) can be lockless.

setsockopt() side is left for later.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-01 19:39:19 +01:00
Eric Dumazet
c4480eb550 inet: lockless IP_PKTOPTIONS implementation
Current implementation is already lockless, because the socket
lock is released before reading socket fields.

Add missing READ_ONCE() annotations.

Note that corresponding WRITE_ONCE() are needed, the order
of the patches do not really matter.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-01 19:39:19 +01:00
Eric Dumazet
959d5c1160 inet: implement lockless getsockopt(IP_UNICAST_IF)
Add missing READ_ONCE() annotations when reading inet->uc_index

Implementing getsockopt(IP_UNICAST_IF) locklessly seems possible,
the setsockopt() part might not be possible at the moment.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-01 19:39:19 +01:00
Eric Dumazet
3523bc91e4 inet: lockless getsockopt(IP_MTU)
sk_dst_get() does not require socket lock.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-01 19:39:19 +01:00
Eric Dumazet
a4725d0d89 inet: lockless getsockopt(IP_OPTIONS)
inet->inet_opt being RCU protected, we can use RCU instead
of locking the socket.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-01 19:39:18 +01:00
Eric Dumazet
e08d0b3d17 inet: implement lockless IP_TOS
Some reads of inet->tos are racy.

Add needed READ_ONCE() annotations and convert IP_TOS option lockless.

v2: missing changes in include/net/route.h (David Ahern)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-01 19:39:18 +01:00
Eric Dumazet
ceaa714138 inet: implement lockless IP_MTU_DISCOVER
inet->pmtudisc can be read locklessly.

Implement proper lockless reads and writes to inet->pmtudisc

ip_sock_set_mtu_discover() can now be called from arbitrary
contexts.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-01 19:39:18 +01:00
Eric Dumazet
c9746e6a19 inet: implement lockless IP_MULTICAST_TTL
inet->mc_ttl can be read locklessly.

Implement proper lockless reads and writes to inet->mc_ttl

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-10-01 19:39:18 +01:00
Eric Dumazet
e3390b30a5 net: annotate data-races around sk->sk_tsflags
sk->sk_tsflags can be read locklessly, add corresponding annotations.

Fixes: b9f40e21ef ("net-timestamp: move timestamp flags out of sk_flags")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-09-01 07:27:33 +01:00
Eric Dumazet
8be6f88b9d inet: fix IP_TRANSPARENT error handling
My recent patch forgot to change error handling for IP_TRANSPARENT
socket option.

WARNING: bad unlock balance detected!
6.5.0-rc7-syzkaller-01717-g59da9885767a #0 Not tainted
-------------------------------------
syz-executor151/5028 is trying to release lock (sk_lock-AF_INET) at:
[<ffffffff88213983>] sockopt_release_sock+0x53/0x70 net/core/sock.c:1073
but there are no more locks to release!

other info that might help us debug this:
1 lock held by syz-executor151/5028:

stack backtrace:
CPU: 0 PID: 5028 Comm: syz-executor151 Not tainted 6.5.0-rc7-syzkaller-01717-g59da9885767a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/26/2023
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
__lock_release kernel/locking/lockdep.c:5438 [inline]
lock_release+0x4b5/0x680 kernel/locking/lockdep.c:5781
sock_release_ownership include/net/sock.h:1824 [inline]
release_sock+0x175/0x1b0 net/core/sock.c:3527
sockopt_release_sock+0x53/0x70 net/core/sock.c:1073
do_ip_setsockopt+0x12c1/0x3640 net/ipv4/ip_sockglue.c:1364
ip_setsockopt+0x59/0xe0 net/ipv4/ip_sockglue.c:1419
raw_setsockopt+0x218/0x290 net/ipv4/raw.c:833
__sys_setsockopt+0x2cd/0x5b0 net/socket.c:2305
__do_sys_setsockopt net/socket.c:2316 [inline]
__se_sys_setsockopt net/socket.c:2313 [inline]

Fixes: 4bd0623f04 ("inet: move inet->transparent to inet->inet_flags")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Simon Horman <horms@kernel.org>
Cc: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-28 10:27:03 +01:00
Eric Dumazet
0f158b32a9 net: selectively purge error queue in IP_RECVERR / IPV6_RECVERR
Setting IP_RECVERR and IPV6_RECVERR options to zero currently
purges the socket error queue, which was probably not expected
for zerocopy and tx_timestamp users.

I discovered this issue while preparing commit 6b5f43ea08
("inet: move inet->recverr to inet->inet_flags"), I presume this
change does not need to be backported to stable kernels.

Add skb_errqueue_purge() helper to purge error messages only.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-20 15:17:47 +01:00
Eric Dumazet
12af73269f inet: implement lockless IP_MINTTL
inet->min_ttl is already read with READ_ONCE().

Implementing IP_MINTTL socket option set/read
without holding the socket lock is easy.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-16 11:09:18 +01:00
Eric Dumazet
10f42426e5 inet: implement lockless IP_TTL
ip_select_ttl() is racy, because it reads inet->uc_ttl
without proper locking.

Add READ_ONCE()/WRITE_ONCE() annotations while
allowing IP_TTL socket option to be set/read without
holding the socket lock.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-16 11:09:18 +01:00
Eric Dumazet
ca571e2eb7 inet: move inet->bind_address_no_port to inet->inet_flags
IP_BIND_ADDRESS_NO_PORT socket option can now be set/read
without locking the socket.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-16 11:09:17 +01:00
Eric Dumazet
f04b8d3478 inet: move inet->nodefrag to inet->inet_flags
IP_NODEFRAG socket option can now be set/read
without locking the socket.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-16 11:09:17 +01:00
Eric Dumazet
b1c0356a58 inet: move inet->is_icsk to inet->inet_flags
We move single bit fields to inet->inet_flags to avoid races.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-16 11:09:17 +01:00
Eric Dumazet
4bd0623f04 inet: move inet->transparent to inet->inet_flags
IP_TRANSPARENT socket option can now be set/read
without locking the socket.

v2: removed unused issk variable in mptcp_setsockopt_sol_ip_set_transparent()
v4: rebased after commit 3f326a821b ("mptcp: change the mpc check helper to return a sk")

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-16 11:09:17 +01:00
Eric Dumazet
307b4ac6dc inet: move inet->mc_all to inet->inet_frags
IP_MULTICAST_ALL socket option can now be set/read
without locking the socket.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-16 11:09:17 +01:00
Eric Dumazet
b09bde5c35 inet: move inet->mc_loop to inet->inet_frags
IP_MULTICAST_LOOP socket option can now be set/read
without locking the socket.

v3: fix build bot error reported in ipvs set_mcast_loop()

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-16 11:09:17 +01:00
Eric Dumazet
cafbe182a4 inet: move inet->hdrincl to inet->inet_flags
IP_HDRINCL socket option can now be set/read
without locking the socket.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-16 11:09:17 +01:00
Eric Dumazet
3f7e753206 inet: move inet->freebind to inet->inet_flags
IP_FREEBIND socket option can now be set/read
without locking the socket.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-16 11:09:17 +01:00
Eric Dumazet
8e8cfb114d inet: move inet->recverr_rfc4884 to inet->inet_flags
IP_RECVERR_RFC4884 socket option can now be set/read
without locking the socket.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-16 11:09:17 +01:00
Eric Dumazet
6b5f43ea08 inet: move inet->recverr to inet->inet_flags
IP_RECVERR socket option can now be set/get without locking the socket.

This patch potentially avoid data-races around inet->recverr.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-16 11:09:17 +01:00
Eric Dumazet
b4d84bce4c inet: set/get simple options locklessly
Now we have inet->inet_flags, we can set following options
without having to hold the socket lock:

IP_PKTINFO, IP_RECVTTL, IP_RECVTOS, IP_RECVOPTS, IP_RETOPTS,
IP_PASSSEC, IP_RECVORIGDSTADDR, IP_RECVFRAGSIZE.

ip_sock_set_pktinfo() no longer hold the socket lock.

Similarly we can get the following options whithout holding
the socket lock:

IP_PKTINFO, IP_RECVTTL, IP_RECVTOS, IP_RECVOPTS, IP_RETOPTS,
IP_PASSSEC, IP_RECVORIGDSTADDR, IP_CHECKSUM, IP_RECVFRAGSIZE.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-16 11:09:17 +01:00
Eric Dumazet
c274af2242 inet: introduce inet->inet_flags
Various inet fields are currently racy.

do_ip_setsockopt() and do_ip_getsockopt() are mostly holding
the socket lock, but some (fast) paths do not.

Use a new inet->inet_flags to hold atomic bits in the series.

Remove inet->cmsg_flags, and use instead 9 bits from inet_flags.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-08-16 11:09:16 +01:00
Eric Dumazet
8bf43be799 net: annotate data-races around sk->sk_priority
sk_getsockopt() runs locklessly. This means sk->sk_priority
can be read while other threads are changing its value.

Other reads also happen without socket lock being held.

Add missing annotations where needed.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-07-29 18:13:41 +01:00
Nicolas Dichtel
3632679d9e ipv{4,6}/raw: fix output xfrm lookup wrt protocol
With a raw socket bound to IPPROTO_RAW (ie with hdrincl enabled), the
protocol field of the flow structure, build by raw_sendmsg() /
rawv6_sendmsg()),  is set to IPPROTO_RAW. This breaks the ipsec policy
lookup when some policies are defined with a protocol in the selector.

For ipv6, the sin6_port field from 'struct sockaddr_in6' could be used to
specify the protocol. Just accept all values for IPPROTO_RAW socket.

For ipv4, the sin_port field of 'struct sockaddr_in' could not be used
without breaking backward compatibility (the value of this field was never
checked). Let's add a new kind of control message, so that the userland
could specify which protocol is used.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
CC: stable@vger.kernel.org
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Link: https://lore.kernel.org/r/20230522120820.1319391-1-nicolas.dichtel@6wind.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-05-23 15:38:59 +02:00
Jakub Sitnicki
91d0b78c51 inet: Add IP_LOCAL_PORT_RANGE socket option
Users who want to share a single public IP address for outgoing connections
between several hosts traditionally reach for SNAT. However, SNAT requires
state keeping on the node(s) performing the NAT.

A stateless alternative exists, where a single IP address used for egress
can be shared between several hosts by partitioning the available ephemeral
port range. In such a setup:

1. Each host gets assigned a disjoint range of ephemeral ports.
2. Applications open connections from the host-assigned port range.
3. Return traffic gets routed to the host based on both, the destination IP
   and the destination port.

An application which wants to open an outgoing connection (connect) from a
given port range today can choose between two solutions:

1. Manually pick the source port by bind()'ing to it before connect()'ing
   the socket.

   This approach has a couple of downsides:

   a) Search for a free port has to be implemented in the user-space. If
      the chosen 4-tuple happens to be busy, the application needs to retry
      from a different local port number.

      Detecting if 4-tuple is busy can be either easy (TCP) or hard
      (UDP). In TCP case, the application simply has to check if connect()
      returned an error (EADDRNOTAVAIL). That is assuming that the local
      port sharing was enabled (REUSEADDR) by all the sockets.

        # Assume desired local port range is 60_000-60_511
        s = socket(AF_INET, SOCK_STREAM)
        s.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1)
        s.bind(("192.0.2.1", 60_000))
        s.connect(("1.1.1.1", 53))
        # Fails only if 192.0.2.1:60000 -> 1.1.1.1:53 is busy
        # Application must retry with another local port

      In case of UDP, the network stack allows binding more than one socket
      to the same 4-tuple, when local port sharing is enabled
      (REUSEADDR). Hence detecting the conflict is much harder and involves
      querying sock_diag and toggling the REUSEADDR flag [1].

   b) For TCP, bind()-ing to a port within the ephemeral port range means
      that no connecting sockets, that is those which leave it to the
      network stack to find a free local port at connect() time, can use
      the this port.

      IOW, the bind hash bucket tb->fastreuse will be 0 or 1, and the port
      will be skipped during the free port search at connect() time.

2. Isolate the app in a dedicated netns and use the use the per-netns
   ip_local_port_range sysctl to adjust the ephemeral port range bounds.

   The per-netns setting affects all sockets, so this approach can be used
   only if:

   - there is just one egress IP address, or
   - the desired egress port range is the same for all egress IP addresses
     used by the application.

   For TCP, this approach avoids the downsides of (1). Free port search and
   4-tuple conflict detection is done by the network stack:

     system("sysctl -w net.ipv4.ip_local_port_range='60000 60511'")

     s = socket(AF_INET, SOCK_STREAM)
     s.setsockopt(SOL_IP, IP_BIND_ADDRESS_NO_PORT, 1)
     s.bind(("192.0.2.1", 0))
     s.connect(("1.1.1.1", 53))
     # Fails if all 4-tuples 192.0.2.1:60000-60511 -> 1.1.1.1:53 are busy

  For UDP this approach has limited applicability. Setting the
  IP_BIND_ADDRESS_NO_PORT socket option does not result in local source
  port being shared with other connected UDP sockets.

  Hence relying on the network stack to find a free source port, limits the
  number of outgoing UDP flows from a single IP address down to the number
  of available ephemeral ports.

To put it another way, partitioning the ephemeral port range between hosts
using the existing Linux networking API is cumbersome.

To address this use case, add a new socket option at the SOL_IP level,
named IP_LOCAL_PORT_RANGE. The new option can be used to clamp down the
ephemeral port range for each socket individually.

The option can be used only to narrow down the per-netns local port
range. If the per-socket range lies outside of the per-netns range, the
latter takes precedence.

UAPI-wise, the low and high range bounds are passed to the kernel as a pair
of u16 values in host byte order packed into a u32. This avoids pointer
passing.

  PORT_LO = 40_000
  PORT_HI = 40_511

  s = socket(AF_INET, SOCK_STREAM)
  v = struct.pack("I", PORT_HI << 16 | PORT_LO)
  s.setsockopt(SOL_IP, IP_LOCAL_PORT_RANGE, v)
  s.bind(("127.0.0.1", 0))
  s.getsockname()
  # Local address between ("127.0.0.1", 40_000) and ("127.0.0.1", 40_511),
  # if there is a free port. EADDRINUSE otherwise.

[1] https://github.com/cloudflare/cloudflare-blog/blob/232b432c1d57/2022-02-connectx/connectx.py#L116

Reviewed-by: Marek Majkowski <marek@cloudflare.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-01-25 22:45:00 -08:00
David Howells
42fb06b391 net: Change the udp encap_err_rcv to allow use of {ip,ipv6}_icmp_error()
Change the udp encap_err_rcv signature to match ip_icmp_error() and
ipv6_icmp_error() so that those can be used from the called function and
export them.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org
2022-11-08 16:42:28 +00:00
xu xin
233baf9a1b net: remove useless parameter of __sock_cmsg_send
The parameter 'msg' has never been used by __sock_cmsg_send, so we can remove it
safely.

Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: xu xin <xu.xin16@zte.com.cn>
Reviewed-by: Zhang Yunkai <zhang.yunkai@zte.com.cn>
Acked-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-10-24 12:43:46 +01:00
Paolo Abeni
2786bcff28 Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2022-09-05

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

We've added 106 non-merge commits during the last 18 day(s) which contain
a total of 159 files changed, 5225 insertions(+), 1358 deletions(-).

There are two small merge conflicts, resolve them as follows:

1) tools/testing/selftests/bpf/DENYLIST.s390x

  Commit 27e23836ce ("selftests/bpf: Add lru_bug to s390x deny list") in
  bpf tree was needed to get BPF CI green on s390x, but it conflicted with
  newly added tests on bpf-next. Resolve by adding both hunks, result:

  [...]
  lru_bug                                  # prog 'printk': failed to auto-attach: -524
  setget_sockopt                           # attach unexpected error: -524                                               (trampoline)
  cb_refs                                  # expected error message unexpected error: -524                               (trampoline)
  cgroup_hierarchical_stats                # JIT does not support calling kernel function                                (kfunc)
  htab_update                              # failed to attach: ERROR: strerror_r(-524)=22                                (trampoline)
  [...]

2) net/core/filter.c

  Commit 1227c1771d ("net: Fix data-races around sysctl_[rw]mem_(max|default).")
  from net tree conflicts with commit 29003875bd ("bpf: Change bpf_setsockopt(SOL_SOCKET)
  to reuse sk_setsockopt()") from bpf-next tree. Take the code as it is from
  bpf-next tree, result:

  [...]
	if (getopt) {
		if (optname == SO_BINDTODEVICE)
			return -EINVAL;
		return sk_getsockopt(sk, SOL_SOCKET, optname,
				     KERNEL_SOCKPTR(optval),
				     KERNEL_SOCKPTR(optlen));
	}

	return sk_setsockopt(sk, SOL_SOCKET, optname,
			     KERNEL_SOCKPTR(optval), *optlen);
  [...]

The main changes are:

1) Add any-context BPF specific memory allocator which is useful in particular for BPF
   tracing with bonus of performance equal to full prealloc, from Alexei Starovoitov.

2) Big batch to remove duplicated code from bpf_{get,set}sockopt() helpers as an effort
   to reuse the existing core socket code as much as possible, from Martin KaFai Lau.

3) Extend BPF flow dissector for BPF programs to just augment the in-kernel dissector
   with custom logic. In other words, allow for partial replacement, from Shmulik Ladkani.

4) Add a new cgroup iterator to BPF with different traversal options, from Hao Luo.

5) Support for BPF to collect hierarchical cgroup statistics efficiently through BPF
   integration with the rstat framework, from Yosry Ahmed.

6) Support bpf_{g,s}et_retval() under more BPF cgroup hooks, from Stanislav Fomichev.

7) BPF hash table and local storages fixes under fully preemptible kernel, from Hou Tao.

8) Add various improvements to BPF selftests and libbpf for compilation with gcc BPF
   backend, from James Hilliard.

9) Fix verifier helper permissions and reference state management for synchronous
   callbacks, from Kumar Kartikeya Dwivedi.

10) Add support for BPF selftest's xskxceiver to also be used against real devices that
    support MAC loopback, from Maciej Fijalkowski.

11) Various fixes to the bpf-helpers(7) man page generation script, from Quentin Monnet.

12) Document BPF verifier's tnum_in(tnum_range(), ...) gotchas, from Shung-Hsi Yu.

13) Various minor misc improvements all over the place.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (106 commits)
  bpf: Optimize rcu_barrier usage between hash map and bpf_mem_alloc.
  bpf: Remove usage of kmem_cache from bpf_mem_cache.
  bpf: Remove prealloc-only restriction for sleepable bpf programs.
  bpf: Prepare bpf_mem_alloc to be used by sleepable bpf programs.
  bpf: Remove tracing program restriction on map types
  bpf: Convert percpu hash map to per-cpu bpf_mem_alloc.
  bpf: Add percpu allocation support to bpf_mem_alloc.
  bpf: Batch call_rcu callbacks instead of SLAB_TYPESAFE_BY_RCU.
  bpf: Adjust low/high watermarks in bpf_mem_cache
  bpf: Optimize call_rcu in non-preallocated hash map.
  bpf: Optimize element count in non-preallocated hash map.
  bpf: Relax the requirement to use preallocated hash maps in tracing progs.
  samples/bpf: Reduce syscall overhead in map_perf_test.
  selftests/bpf: Improve test coverage of test_maps
  bpf: Convert hash map to bpf_mem_alloc.
  bpf: Introduce any context BPF specific memory allocator.
  selftest/bpf: Add test for bpf_getsockopt()
  bpf: Change bpf_getsockopt(SOL_IPV6) to reuse do_ipv6_getsockopt()
  bpf: Change bpf_getsockopt(SOL_IP) to reuse do_ip_getsockopt()
  bpf: Change bpf_getsockopt(SOL_TCP) to reuse do_tcp_getsockopt()
  ...
====================

Link: https://lore.kernel.org/r/20220905161136.9150-1-daniel@iogearbox.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2022-09-06 23:21:18 +02:00
Martin KaFai Lau
fd969f25fe bpf: Change bpf_getsockopt(SOL_IP) to reuse do_ip_getsockopt()
This patch changes bpf_getsockopt(SOL_IP) to reuse
do_ip_getsockopt() and remove the duplicated code.

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20220902002925.2895416-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-09-02 20:34:32 -07:00
Martin KaFai Lau
1985320c54 bpf: net: Avoid do_ip_getsockopt() taking sk lock when called from bpf
Similar to the earlier commit that changed sk_setsockopt() to
use sockopt_{lock,release}_sock() such that it can avoid taking
lock when called from bpf.  This patch also changes do_ip_getsockopt()
to use sockopt_{lock,release}_sock() such that a latter patch can
make bpf_getsockopt(SOL_IP) to reuse do_ip_getsockopt().

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20220902002834.2891514-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-09-02 20:34:31 -07:00
Martin KaFai Lau
728f064cd7 bpf: net: Change do_ip_getsockopt() to take the sockptr_t argument
Similar to the earlier patch that changes sk_getsockopt() to
take the sockptr_t argument.  This patch also changes
do_ip_getsockopt() to take the sockptr_t argument such that
a latter patch can make bpf_getsockopt(SOL_IP) to reuse
do_ip_getsockopt().

Note on the change in ip_mc_gsfget().  This function is to
return an array of sockaddr_storage in optval.  This function
is shared between ip_get_mcast_msfilter() and
compat_ip_get_mcast_msfilter().  However, the sockaddr_storage
is stored at different offset of the optval because of
the difference between group_filter and compat_group_filter.
Thus, a new 'ss_offset' argument is added to ip_mc_gsfget().

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20220902002828.2890585-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-09-02 20:34:31 -07:00
Kuniyuki Iwashima
7de6d09f51 net: Fix data-races around sysctl_optmem_max.
While reading sysctl_optmem_max, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-08-24 13:46:57 +01:00
Martin KaFai Lau
ee7f1e1302 bpf: Change bpf_setsockopt(SOL_IP) to reuse do_ip_setsockopt()
After the prep work in the previous patches,
this patch removes the dup code from bpf_setsockopt(SOL_IP)
and reuses the implementation in do_ip_setsockopt().

The existing optname white-list is refactored into a new
function sol_ip_setsockopt().

NOTE,
the current bpf_setsockopt(IP_TOS) is quite different from the
the do_ip_setsockopt(IP_TOS).  For example, it does not take
the INET_ECN_MASK into the account for tcp and also does not adjust
sk->sk_priority.  It looks like the current bpf_setsockopt(IP_TOS)
was referencing the IPV6_TCLASS implementation instead of IP_TOS.
This patch tries to rectify that by using the do_ip_setsockopt(IP_TOS).
While this is a behavior change,  the do_ip_setsockopt(IP_TOS) behavior
is arguably what the user is expecting.  At least, the INET_ECN_MASK bits
should be masked out for tcp.

Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220817061826.4180990-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-18 17:06:13 -07:00
Martin KaFai Lau
1df055d3c7 bpf: net: Change do_ip_setsockopt() to use the sockopt's lock_sock() and capable()
Similar to the earlier patch that avoids sk_setsockopt() from
taking sk lock and doing capable test when called by bpf.  This patch
changes do_ip_setsockopt() to use the sockopt_{lock,release}_sock()
and sockopt_[ns_]capable().

Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220817061737.4176402-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-08-18 17:06:13 -07:00
Kuniyuki Iwashima
6ae0f2e553 igmp: Fix data-races around sysctl_igmp_max_msf.
While reading sysctl_igmp_max_msf, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-18 12:21:53 +01:00
Kuniyuki Iwashima
8281b7ec5c ip: Fix data-races around sysctl_ip_default_ttl.
While reading sysctl_ip_default_ttl, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-07-15 11:49:55 +01:00
Poorva Sonparote
4f47d5d507 ipv4: Exposing __ip_sock_set_tos() in ip.h
Making the static function __ip_sock_set_tos() from net/ipv4/ip_sockglue.c
accessible by declaring it in include/net/ip.h
The reason for doing this is to use this function to set IP_TOS value in
mptcp_setsockopt() without the lock.

Signed-off-by: Poorva Sonparote <psonparo@redhat.com>
Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-11-20 14:11:00 +00:00
Eric Dumazet
020e71a3cf ipv4: guard IP_MINTTL with a static key
RFC 5082 IP_MINTTL option is rarely used on hosts.

Add a static key to remove from TCP fast path useless code,
and potential cache line miss to fetch inet_sk(sk)->min_ttl

Note that once ip4_min_ttl static key has been enabled,
it stays enabled until next boot.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-10-25 18:02:14 -07:00
Eric Dumazet
14834c4f4e ipv4: annotate data races arount inet->min_ttl
No report yet from KCSAN, yet worth documenting the races.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-10-25 18:02:13 -07:00
Gustavo A. R. Silva
db243b7964 net/ipv4/ipv6: Replace one-element arraya with flexible-array members
There is a regular need in the kernel to provide a way to declare having
a dynamically sized set of trailing elements in a structure. Kernel code
should always use “flexible array members”[1] for these cases. The older
style of one-element or zero-length arrays should no longer be used[2].

Use an anonymous union with a couple of anonymous structs in order to
keep userspace unchanged and refactor the related code accordingly:

$ pahole -C group_filter net/ipv4/ip_sockglue.o
struct group_filter {
	union {
		struct {
			__u32      gf_interface_aux;     /*     0     4 */

			/* XXX 4 bytes hole, try to pack */

			struct __kernel_sockaddr_storage gf_group_aux; /*     8   128 */
			/* --- cacheline 2 boundary (128 bytes) was 8 bytes ago --- */
			__u32      gf_fmode_aux;         /*   136     4 */
			__u32      gf_numsrc_aux;        /*   140     4 */
			struct __kernel_sockaddr_storage gf_slist[1]; /*   144   128 */
		};                                       /*     0   272 */
		struct {
			__u32      gf_interface;         /*     0     4 */

			/* XXX 4 bytes hole, try to pack */

			struct __kernel_sockaddr_storage gf_group; /*     8   128 */
			/* --- cacheline 2 boundary (128 bytes) was 8 bytes ago --- */
			__u32      gf_fmode;             /*   136     4 */
			__u32      gf_numsrc;            /*   140     4 */
			struct __kernel_sockaddr_storage gf_slist_flex[0]; /*   144     0 */
		};                                       /*     0   144 */
	};                                               /*     0   272 */

	/* size: 272, cachelines: 5, members: 1 */
	/* last cacheline: 16 bytes */
};

$ pahole -C compat_group_filter net/ipv4/ip_sockglue.o
struct compat_group_filter {
	union {
		struct {
			__u32      gf_interface_aux;     /*     0     4 */
			struct __kernel_sockaddr_storage gf_group_aux __attribute__((__aligned__(4))); /*     4   128 */
			/* --- cacheline 2 boundary (128 bytes) was 4 bytes ago --- */
			__u32      gf_fmode_aux;         /*   132     4 */
			__u32      gf_numsrc_aux;        /*   136     4 */
			struct __kernel_sockaddr_storage gf_slist[1] __attribute__((__aligned__(4))); /*   140   128 */
		} __attribute__((__packed__)) __attribute__((__aligned__(4)));                     /*     0   268 */
		struct {
			__u32      gf_interface;         /*     0     4 */
			struct __kernel_sockaddr_storage gf_group __attribute__((__aligned__(4))); /*     4   128 */
			/* --- cacheline 2 boundary (128 bytes) was 4 bytes ago --- */
			__u32      gf_fmode;             /*   132     4 */
			__u32      gf_numsrc;            /*   136     4 */
			struct __kernel_sockaddr_storage gf_slist_flex[0] __attribute__((__aligned__(4))); /*   140     0 */
		} __attribute__((__packed__)) __attribute__((__aligned__(4)));                     /*     0   140 */
	} __attribute__((__aligned__(1)));               /*     0   268 */

	/* size: 268, cachelines: 5, members: 1 */
	/* forced alignments: 1 */
	/* last cacheline: 12 bytes */
} __attribute__((__packed__));

This helps with the ongoing efforts to globally enable -Warray-bounds
and get us closer to being able to tighten the FORTIFY_SOURCE routines
on memcpy().

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays

Link: https://github.com/KSPP/linux/issues/79
Link: https://github.com/KSPP/linux/issues/109
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-05 11:46:42 +01:00
Gustavo A. R. Silva
4167a96057 net/ipv4: Revert use of struct_size() helper
Revert the use of structr_size() and stay with IP_MSFILTER_SIZE() for
now, as in this case, the size of struct ip_msfilter didn't change with
the addition of the flexible array imsf_slist_flex[]. So, if we use
struct_size() we will be allocating and calculating the size of
struct ip_msfilter with one too many items for imsf_slist_flex[].

We might use struct_size() in the future, but for now let's stay
with IP_MSFILTER_SIZE().

Fixes: 	2d3e5caf96 ("net/ipv4: Replace one-element array with flexible-array member")
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-05 11:33:50 +01:00
Gustavo A. R. Silva
2d3e5caf96 net/ipv4: Replace one-element array with flexible-array member
There is a regular need in the kernel to provide a way to declare having
a dynamically sized set of trailing elements in a structure. Kernel code
should always use “flexible array members”[1] for these cases. The older
style of one-element or zero-length arrays should no longer be used[2].

Use an anonymous union with a couple of anonymous structs in order to
keep userspace unchanged:

$ pahole -C ip_msfilter net/ipv4/ip_sockglue.o
struct ip_msfilter {
	union {
		struct {
			__be32     imsf_multiaddr_aux;   /*     0     4 */
			__be32     imsf_interface_aux;   /*     4     4 */
			__u32      imsf_fmode_aux;       /*     8     4 */
			__u32      imsf_numsrc_aux;      /*    12     4 */
			__be32     imsf_slist[1];        /*    16     4 */
		};                                       /*     0    20 */
		struct {
			__be32     imsf_multiaddr;       /*     0     4 */
			__be32     imsf_interface;       /*     4     4 */
			__u32      imsf_fmode;           /*     8     4 */
			__u32      imsf_numsrc;          /*    12     4 */
			__be32     imsf_slist_flex[0];   /*    16     0 */
		};                                       /*     0    16 */
	};                                               /*     0    20 */

	/* size: 20, cachelines: 1, members: 1 */
	/* last cacheline: 20 bytes */
};

Also, refactor the code accordingly and make use of the struct_size()
and flex_array_size() helpers.

This helps with the ongoing efforts to globally enable -Warray-bounds
and get us closer to being able to tighten the FORTIFY_SOURCE routines
on memcpy().

[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://www.kernel.org/doc/html/v5.10/process/deprecated.html#zero-length-and-one-element-arrays

Link: https://github.com/KSPP/linux/issues/79
Link: https://github.com/KSPP/linux/issues/109
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-02 15:17:28 +01:00