linux-toradex.git/net/ipv4/fib_trie.c, branch v5.17-rc4 Linux kernel for Apalis and Colibri modules memcg: enable accounting for IP address and routing-related objects 2021-07-20T13:00:38+00:00 Vasily Averin vvs@virtuozzo.com 2021-07-19T10:44:31+00:00 6126891c6d4f6f4ef50323d2020635ee255a796e An netadmin inside container can use 'ip a a' and 'ip r a' to assign a large number of ipv4/ipv6 addresses and routing entries and force kernel to allocate megabytes of unaccounted memory for long-lived per-netdevice related kernel objects: 'struct in_ifaddr', 'struct inet6_ifaddr', 'struct fib6_node', 'struct rt6_info', 'struct fib_rules' and ip_fib caches. These objects can be manually removed, though usually they lives in memory till destroy of its net namespace. It makes sense to account for them to restrict the host's memory consumption from inside the memcg-limited container. One of such objects is the 'struct fib6_node' mostly allocated in net/ipv6/route.c::__ip6_ins_rt() inside the lock_bh()/unlock_bh() section: write_lock_bh(&table->tb6_lock); err = fib6_add(&table->tb6_root, rt, info, mxc); write_unlock_bh(&table->tb6_lock); In this case it is not enough to simply add SLAB_ACCOUNT to corresponding kmem cache. The proper memory cgroup still cannot be found due to the incorrect 'in_interrupt()' check used in memcg_kmem_bypass(). Obsoleted in_interrupt() does not describe real execution context properly. >From include/linux/preempt.h: The following macros are deprecated and should not be used in new code: in_interrupt() - We're in NMI,IRQ,SoftIRQ context or have BH disabled To verify the current execution context new macro should be used instead: in_task() - We're in task context Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
An netadmin inside container can use 'ip a a' and 'ip r a'
to assign a large number of ipv4/ipv6 addresses and routing entries
and force kernel to allocate megabytes of unaccounted memory
for long-lived per-netdevice related kernel objects:
'struct in_ifaddr', 'struct inet6_ifaddr', 'struct fib6_node',
'struct rt6_info', 'struct fib_rules' and ip_fib caches.

These objects can be manually removed, though usually they lives
in memory till destroy of its net namespace.

It makes sense to account for them to restrict the host's memory
consumption from inside the memcg-limited container.

One of such objects is the 'struct fib6_node' mostly allocated in
net/ipv6/route.c::__ip6_ins_rt() inside the lock_bh()/unlock_bh() section:

 write_lock_bh(&table->tb6_lock);
 err = fib6_add(&table->tb6_root, rt, info, mxc);
 write_unlock_bh(&table->tb6_lock);

In this case it is not enough to simply add SLAB_ACCOUNT to corresponding
kmem cache. The proper memory cgroup still cannot be found due to the
incorrect 'in_interrupt()' check used in memcg_kmem_bypass().

Obsoleted in_interrupt() does not describe real execution context properly.
>From include/linux/preempt.h:

 The following macros are deprecated and should not be used in new code:
 in_interrupt()	- We're in NMI,IRQ,SoftIRQ context or have BH disabled

To verify the current execution context new macro should be used instead:
 in_task()	- We're in task context

Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
IPv4: Extend 'fib_notify_on_flag_change' sysctl 2021-02-09T00:47:03+00:00 Amit Cohen amcohen@nvidia.com 2021-02-07T08:22:51+00:00 648106c30a635e18fb55da60d4fcbfca6f6483ac Add the value '2' to 'fib_notify_on_flag_change' to allow sending notifications only for failed route installation. Separate value is added for such notifications because there are less of them, so they do not impact performance and some users will find them more important. Signed-off-by: Amit Cohen <amcohen@nvidia.com> Signed-off-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Add the value '2' to 'fib_notify_on_flag_change' to allow sending
notifications only for failed route installation.

Separate value is added for such notifications because there are less of
them, so they do not impact performance and some users will find them more
important.

Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
IPv4: Add "offload failed" indication to routes 2021-02-09T00:47:03+00:00 Amit Cohen amcohen@nvidia.com 2021-02-07T08:22:50+00:00 36c5100e859d93b3436ae24810612b05addb1e89 After installing a route to the kernel, user space receives an acknowledgment, which means the route was installed in the kernel, but not necessarily in hardware. The asynchronous nature of route installation in hardware can lead to a routing daemon advertising a route before it was actually installed in hardware. This can result in packet loss or mis-routed packets until the route is installed in hardware. To avoid such cases, previous patch set added the ability to emit RTM_NEWROUTE notifications whenever RTM_F_OFFLOAD/RTM_F_TRAP flags are changed, this behavior is controlled by sysctl. With the above mentioned behavior, it is possible to know from user-space if the route was offloaded, but if the offload fails there is no indication to user-space. Following a failure, a routing daemon will wait indefinitely for a notification that will never come. This patch adds an "offload_failed" indication to IPv4 routes, so that users will have better visibility into the offload process. 'struct fib_alias', and 'struct fib_rt_info' are extended with new field that indicates if route offload failed. Note that the new field is added using unused bit and therefore there is no need to increase structs size. Signed-off-by: Amit Cohen <amcohen@nvidia.com> Signed-off-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
After installing a route to the kernel, user space receives an
acknowledgment, which means the route was installed in the kernel, but not
necessarily in hardware.

The asynchronous nature of route installation in hardware can lead to a
routing daemon advertising a route before it was actually installed in
hardware. This can result in packet loss or mis-routed packets until the
route is installed in hardware.

To avoid such cases, previous patch set added the ability to emit
RTM_NEWROUTE notifications whenever RTM_F_OFFLOAD/RTM_F_TRAP flags
are changed, this behavior is controlled by sysctl.

With the above mentioned behavior, it is possible to know from user-space
if the route was offloaded, but if the offload fails there is no indication
to user-space. Following a failure, a routing daemon will wait indefinitely
for a notification that will never come.

This patch adds an "offload_failed" indication to IPv4 routes, so that
users will have better visibility into the offload process.

'struct fib_alias', and 'struct fib_rt_info' are extended with new field
that indicates if route offload failed. Note that the new field is added
using unused bit and therefore there is no need to increase structs size.

Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: ipv4: Emit notification when fib hardware flags are changed 2021-02-03T01:45:59+00:00 Amit Cohen amcohen@nvidia.com 2021-02-01T19:47:52+00:00 680aea08e78c003292415518ad270bc20f9c80b1 After installing a route to the kernel, user space receives an acknowledgment, which means the route was installed in the kernel, but not necessarily in hardware. The asynchronous nature of route installation in hardware can lead to a routing daemon advertising a route before it was actually installed in hardware. This can result in packet loss or mis-routed packets until the route is installed in hardware. It is also possible for a route already installed in hardware to change its action and therefore its flags. For example, a host route that is trapping packets can be "promoted" to perform decapsulation following the installation of an IPinIP/VXLAN tunnel. Emit RTM_NEWROUTE notifications whenever RTM_F_OFFLOAD/RTM_F_TRAP flags are changed. The aim is to provide an indication to user-space (e.g., routing daemons) about the state of the route in hardware. Introduce a sysctl that controls this behavior. Keep the default value at 0 (i.e., do not emit notifications) for several reasons: - Multiple RTM_NEWROUTE notification per-route might confuse existing routing daemons. - Convergence reasons in routing daemons. - The extra notifications will negatively impact the insertion rate. - Not all users are interested in these notifications. Signed-off-by: Amit Cohen <amcohen@nvidia.com> Acked-by: Roopa Prabhu <roopa@nvidia.com> Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
After installing a route to the kernel, user space receives an
acknowledgment, which means the route was installed in the kernel,
but not necessarily in hardware.

The asynchronous nature of route installation in hardware can lead to a
routing daemon advertising a route before it was actually installed in
hardware. This can result in packet loss or mis-routed packets until the
route is installed in hardware.

It is also possible for a route already installed in hardware to change
its action and therefore its flags. For example, a host route that is
trapping packets can be "promoted" to perform decapsulation following
the installation of an IPinIP/VXLAN tunnel.

Emit RTM_NEWROUTE notifications whenever RTM_F_OFFLOAD/RTM_F_TRAP flags
are changed. The aim is to provide an indication to user-space
(e.g., routing daemons) about the state of the route in hardware.

Introduce a sysctl that controls this behavior.

Keep the default value at 0 (i.e., do not emit notifications) for several
reasons:
- Multiple RTM_NEWROUTE notification per-route might confuse existing
  routing daemons.
- Convergence reasons in routing daemons.
- The extra notifications will negatively impact the insertion rate.
- Not all users are interested in these notifications.

Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Acked-by: Roopa Prabhu <roopa@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
nexthop: Remove in-kernel route notifications when nexthop changes 2020-11-06T19:28:50+00:00 Ido Schimmel idosch@nvidia.com 2020-11-04T13:30:36+00:00 bbea126c2badf677925e46083d708ca292c530f6 Remove in-kernel route notifications when the configuration of their nexthop changes. These notifications are unnecessary because the route still uses the same nexthop ID. A separate notification for the nexthop change itself is now sent in the nexthop notification chain. Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Remove in-kernel route notifications when the configuration of their
nexthop changes.

These notifications are unnecessary because the route still uses the
same nexthop ID. A separate notification for the nexthop change itself
is now sent in the nexthop notification chain.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
ipv4: Silence suspicious RCU usage warning 2020-08-26T22:58:48+00:00 Ido Schimmel idosch@nvidia.com 2020-08-26T16:48:10+00:00 7f6f32bb7d3355cd78ebf1dece9a6ea7a0ca8158 fib_info_notify_update() is always called with RTNL held, but not from an RCU read-side critical section. This leads to the following warning [1] when the FIB table list is traversed with hlist_for_each_entry_rcu(), but without a proper lockdep expression. Since modification of the list is protected by RTNL, silence the warning by adding a lockdep expression which verifies RTNL is held. [1] ============================= WARNING: suspicious RCU usage 5.9.0-rc1-custom-14233-g2f26e122d62f #129 Not tainted ----------------------------- net/ipv4/fib_trie.c:2124 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by ip/834: #0: ffffffff85a3b6b0 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x49a/0xbd0 stack backtrace: CPU: 0 PID: 834 Comm: ip Not tainted 5.9.0-rc1-custom-14233-g2f26e122d62f #129 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-2.fc32 04/01/2014 Call Trace: dump_stack+0x100/0x184 lockdep_rcu_suspicious+0x143/0x14d fib_info_notify_update+0x8d1/0xa60 __nexthop_replace_notify+0xd2/0x290 rtm_new_nexthop+0x35e2/0x5946 rtnetlink_rcv_msg+0x4f7/0xbd0 netlink_rcv_skb+0x17a/0x480 rtnetlink_rcv+0x22/0x30 netlink_unicast+0x5ae/0x890 netlink_sendmsg+0x98a/0xf40 ____sys_sendmsg+0x879/0xa00 ___sys_sendmsg+0x122/0x190 __sys_sendmsg+0x103/0x1d0 __x64_sys_sendmsg+0x7d/0xb0 do_syscall_64+0x32/0x50 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7fde28c3be57 Code: 0c 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10 RSP: 002b:00007ffc09330028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fde28c3be57 RDX: 0000000000000000 RSI: 00007ffc09330090 RDI: 0000000000000003 RBP: 000000005f45f911 R08: 0000000000000001 R09: 00007ffc0933012c R10: 0000000000000076 R11: 0000000000000246 R12: 0000000000000001 R13: 00007ffc09330290 R14: 00007ffc09330eee R15: 00005610e48ed020 Fixes: 1bff1a0c9bbd ("ipv4: Add function to send route updates") Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
fib_info_notify_update() is always called with RTNL held, but not from
an RCU read-side critical section. This leads to the following warning
[1] when the FIB table list is traversed with
hlist_for_each_entry_rcu(), but without a proper lockdep expression.

Since modification of the list is protected by RTNL, silence the warning
by adding a lockdep expression which verifies RTNL is held.

[1]
 =============================
 WARNING: suspicious RCU usage
 5.9.0-rc1-custom-14233-g2f26e122d62f #129 Not tainted
 -----------------------------
 net/ipv4/fib_trie.c:2124 RCU-list traversed in non-reader section!!

 other info that might help us debug this:

 rcu_scheduler_active = 2, debug_locks = 1
 1 lock held by ip/834:
  #0: ffffffff85a3b6b0 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x49a/0xbd0

 stack backtrace:
 CPU: 0 PID: 834 Comm: ip Not tainted 5.9.0-rc1-custom-14233-g2f26e122d62f #129
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-2.fc32 04/01/2014
 Call Trace:
  dump_stack+0x100/0x184
  lockdep_rcu_suspicious+0x143/0x14d
  fib_info_notify_update+0x8d1/0xa60
  __nexthop_replace_notify+0xd2/0x290
  rtm_new_nexthop+0x35e2/0x5946
  rtnetlink_rcv_msg+0x4f7/0xbd0
  netlink_rcv_skb+0x17a/0x480
  rtnetlink_rcv+0x22/0x30
  netlink_unicast+0x5ae/0x890
  netlink_sendmsg+0x98a/0xf40
  ____sys_sendmsg+0x879/0xa00
  ___sys_sendmsg+0x122/0x190
  __sys_sendmsg+0x103/0x1d0
  __x64_sys_sendmsg+0x7d/0xb0
  do_syscall_64+0x32/0x50
  entry_SYSCALL_64_after_hwframe+0x44/0xa9
 RIP: 0033:0x7fde28c3be57
 Code: 0c 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51
c3 48 83 ec 28 89 54 24 1c 48 89 74 24 10
RSP: 002b:00007ffc09330028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fde28c3be57
RDX: 0000000000000000 RSI: 00007ffc09330090 RDI: 0000000000000003
RBP: 000000005f45f911 R08: 0000000000000001 R09: 00007ffc0933012c
R10: 0000000000000076 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffc09330290 R14: 00007ffc09330eee R15: 00005610e48ed020

Fixes: 1bff1a0c9bbd ("ipv4: Add function to send route updates")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-08-02T08:02:12+00:00 David S. Miller davem@davemloft.net 2020-08-02T08:02:12+00:00 bd0b33b24897ba9ddad221e8ac5b6f0e38a2e004 Resolved kernel/bpf/btf.c using instructions from merge commit 69138b34a7248d2396ab85c8652e20c0c39beaba Signed-off-by: David S. Miller <davem@davemloft.net> 
Resolved kernel/bpf/btf.c using instructions from merge commit
69138b34a7248d2396ab85c8652e20c0c39beaba

Signed-off-by: David S. Miller <davem@davemloft.net>
ipv4: Silence suspicious RCU usage warning 2020-07-29T19:12:50+00:00 Ido Schimmel idosch@mellanox.com 2020-07-29T08:37:13+00:00 83f3522860f702748143e022f1a546547314c715 fib_trie_unmerge() is called with RTNL held, but not from an RCU read-side critical section. This leads to the following warning [1] when the FIB alias list in a leaf is traversed with hlist_for_each_entry_rcu(). Since the function is always called with RTNL held and since modification of the list is protected by RTNL, simply use hlist_for_each_entry() and silence the warning. [1] WARNING: suspicious RCU usage 5.8.0-rc4-custom-01520-gc1f937f3f83b #30 Not tainted ----------------------------- net/ipv4/fib_trie.c:1867 RCU-list traversed in non-reader section!! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by ip/164: #0: ffffffff85a27850 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x49a/0xbd0 stack backtrace: CPU: 0 PID: 164 Comm: ip Not tainted 5.8.0-rc4-custom-01520-gc1f937f3f83b #30 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-2.fc32 04/01/2014 Call Trace: dump_stack+0x100/0x184 lockdep_rcu_suspicious+0x153/0x15d fib_trie_unmerge+0x608/0xdb0 fib_unmerge+0x44/0x360 fib4_rule_configure+0xc8/0xad0 fib_nl_newrule+0x37a/0x1dd0 rtnetlink_rcv_msg+0x4f7/0xbd0 netlink_rcv_skb+0x17a/0x480 rtnetlink_rcv+0x22/0x30 netlink_unicast+0x5ae/0x890 netlink_sendmsg+0x98a/0xf40 ____sys_sendmsg+0x879/0xa00 ___sys_sendmsg+0x122/0x190 __sys_sendmsg+0x103/0x1d0 __x64_sys_sendmsg+0x7d/0xb0 do_syscall_64+0x54/0xa0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7fc80a234e97 Code: Bad RIP value. RSP: 002b:00007ffef8b66798 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc80a234e97 RDX: 0000000000000000 RSI: 00007ffef8b66800 RDI: 0000000000000003 RBP: 000000005f141b1c R08: 0000000000000001 R09: 0000000000000000 R10: 00007fc80a2a8ac0 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000000 R14: 00007ffef8b67008 R15: 0000556fccb10020 Fixes: 0ddcf43d5d4a ("ipv4: FIB Local/MAIN table collapse") Signed-off-by: Ido Schimmel <idosch@mellanox.com> Reviewed-by: Jiri Pirko <jiri@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
fib_trie_unmerge() is called with RTNL held, but not from an RCU
read-side critical section. This leads to the following warning [1] when
the FIB alias list in a leaf is traversed with
hlist_for_each_entry_rcu().

Since the function is always called with RTNL held and since
modification of the list is protected by RTNL, simply use
hlist_for_each_entry() and silence the warning.

[1]
WARNING: suspicious RCU usage
5.8.0-rc4-custom-01520-gc1f937f3f83b #30 Not tainted
-----------------------------
net/ipv4/fib_trie.c:1867 RCU-list traversed in non-reader section!!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
1 lock held by ip/164:
 #0: ffffffff85a27850 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x49a/0xbd0

stack backtrace:
CPU: 0 PID: 164 Comm: ip Not tainted 5.8.0-rc4-custom-01520-gc1f937f3f83b #30
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-2.fc32 04/01/2014
Call Trace:
 dump_stack+0x100/0x184
 lockdep_rcu_suspicious+0x153/0x15d
 fib_trie_unmerge+0x608/0xdb0
 fib_unmerge+0x44/0x360
 fib4_rule_configure+0xc8/0xad0
 fib_nl_newrule+0x37a/0x1dd0
 rtnetlink_rcv_msg+0x4f7/0xbd0
 netlink_rcv_skb+0x17a/0x480
 rtnetlink_rcv+0x22/0x30
 netlink_unicast+0x5ae/0x890
 netlink_sendmsg+0x98a/0xf40
 ____sys_sendmsg+0x879/0xa00
 ___sys_sendmsg+0x122/0x190
 __sys_sendmsg+0x103/0x1d0
 __x64_sys_sendmsg+0x7d/0xb0
 do_syscall_64+0x54/0xa0
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fc80a234e97
Code: Bad RIP value.
RSP: 002b:00007ffef8b66798 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc80a234e97
RDX: 0000000000000000 RSI: 00007ffef8b66800 RDI: 0000000000000003
RBP: 000000005f141b1c R08: 0000000000000001 R09: 0000000000000000
R10: 00007fc80a2a8ac0 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000000 R14: 00007ffef8b67008 R15: 0000556fccb10020

Fixes: 0ddcf43d5d4a ("ipv4: FIB Local/MAIN table collapse")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Replace HTTP links with HTTPS ones: IPv* 2020-07-06T20:23:03+00:00 Alexander A. Klimov grandmaster@al2klimov.de 2020-07-06T17:38:50+00:00 7a6498ebcdc0fde4613a20ae405481d49166e8bb Rationale: Reduces attack surface on kernel devs opening the links for MITM as HTTPS traffic is much harder to manipulate. Deterministic algorithm: For each file: If not .svg: For each line: If doesn't contain `\bxmlns\b`: For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`: If both the HTTP and HTTPS versions return 200 OK and serve the same content: Replace HTTP with HTTPS. Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de> Signed-off-by: David S. Miller <davem@davemloft.net> 
Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Deterministic algorithm:
For each file:
  If not .svg:
    For each line:
      If doesn't contain `\bxmlns\b`:
        For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
          If both the HTTP and HTTPS versions
          return 200 OK and serve the same content:
            Replace HTTP with HTTPS.

Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
ipv4: Refactor nhc evaluation in fib_table_lookup 2020-05-26T23:06:07+00:00 David Ahern dsahern@gmail.com 2020-05-26T18:56:17+00:00 af7888ad9edbd8ba7f6449d1c27ce281ad4b26fd FIB lookups can return an entry that references an external nexthop. While walking the nexthop struct we do not want to make multiple calls into the nexthop code which can result in 2 different structs getting accessed - one returning the number of paths the rest of the loop seeing a different nh_grp struct. If the nexthop group shrunk, the result is an attempt to access a fib_nh_common that does not exist for the new nh_grp struct but did for the old one. To fix that move the device evaluation code to a helper that can be used for inline fib_nh path as well as external nexthops. Update the existing check for fi->nh in fib_table_lookup to call a new helper, nexthop_get_nhc_lookup, which walks the external nexthop with a single rcu dereference. Fixes: 430a049190de ("nexthop: Add support for nexthop groups") Signed-off-by: David Ahern <dsahern@gmail.com> Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
FIB lookups can return an entry that references an external nexthop.
While walking the nexthop struct we do not want to make multiple calls
into the nexthop code which can result in 2 different structs getting
accessed - one returning the number of paths the rest of the loop
seeing a different nh_grp struct. If the nexthop group shrunk, the
result is an attempt to access a fib_nh_common that does not exist for
the new nh_grp struct but did for the old one.

To fix that move the device evaluation code to a helper that can be
used for inline fib_nh path as well as external nexthops.

Update the existing check for fi->nh in fib_table_lookup to call a
new helper, nexthop_get_nhc_lookup, which walks the external nexthop
with a single rcu dereference.

Fixes: 430a049190de ("nexthop: Add support for nexthop groups")
Signed-off-by: David Ahern <dsahern@gmail.com>
Acked-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>