Step 5/10 of the namespace unification of CPU mitigations related Kconfig options.
[ mingo: Converted a few more uses in comments/messages as well. ]
Suggested-by: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Ariel Miculas <amiculas@cisco.com>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20231121160740.1249350-6-leitao@debian.org
Before this patch, transport offset (pkt->thoff) provides an offset
relative to the network header. This is fine for the inet families
because skb->data points to the network header in such case. However,
from netdev/egress, skb->data points to the mac header (if available),
thus, pkt->thoff is missing the mac header length.
Add skb_network_offset() to the transport offset (pkt->thoff) for
netdev, so transport header mangling works as expected. Adjust payload
fast eval function to use skb->data now that pkt->thoff provides an
absolute offset. This explains why users report that matching on
egress/netdev works but payload mangling does not.
This patch implicitly fixes payload mangling for IPv4 packets in
netdev/egress given skb_store_bits() requires an offset from skb->data
to reach the transport header.
I suspect that nft_exthdr and the trace infra were also broken from
netdev/egress because they also take skb->data as start, and pkt->thoff
was not correct.
Note that IPv6 is fine because ipv6_find_hdr() already provides a
transport offset starting from skb->data, which includes
skb_network_offset().
The bridge family also uses nft_set_pktinfo_ipv4_validate(), but there
skb_network_offset() is zero, so the update in this patch does not alter
the existing behaviour.
Fixes: 42df6e1d22 ("netfilter: Introduce egress hook")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
net_dropmonitor blames core.c:nf_hook_slow.
Add NF_DROP_REASON() helper and use it in nft_do_chain().
The helper releases the skb, so exact drop location becomes
available. Calling code will observe the NF_STOLEN verdict
instead.
Adjust nf_hook_slow so we can embed an erro value wih
NF_STOLEN verdicts, just like we do for NF_DROP.
After this, drop in nftables can be pinpointed to a drop due
to a rule or the chain policy.
Signed-off-by: Florian Westphal <fw@strlen.de>
nftables trace infra must mask out the non-verdict bit parts of the
return value, else followup changes that 'return errno << 8 | NF_STOLEN'
will cause breakage.
Signed-off-by: Florian Westphal <fw@strlen.de>
pass it as argument instead. This reduces size of traceinfo to
16 bytes. Total stack usage:
nf_tables_core.c:252 nft_do_chain 304 static
While its possible to also pass basechain as argument, doing so
increases nft_do_chaininfo function size.
Unlike pktinfo/verdict/rule the basechain info isn't used in
the expression evaluation path. gcc places it on the stack, which
results in extra push/pop when it gets passed to the trace helpers
as argument rather than as part of the traceinfo structure.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Just pass it as argument to nft_trace_notify. Stack is reduced by 8 bytes:
nf_tables_core.c:256 nft_do_chain 312 static
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
pass it as argument. No change in object size.
stack usage decreases by 8 byte:
nf_tables_core.c:254 nft_do_chain 320 static
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This helper is inlined, so keep it as small as possible.
If the static key is true, there is only a very small chance
that info->trace is false:
1. tracing was enabled at this very moment, the static key was
updated to active right after nft_do_table was called.
2. tracing was disabled at this very moment.
trace->info is already false, the static key is about to
be patched to false soon.
In both cases, no event will be sent because info->trace
is false (checked in noinline slowpath). info->nf_trace is irrelevant.
The nf_trace update is redunant in this case, but this will only
happen for short duration, when static key flips.
text data bss dec hex filename
old: 2980 192 32 3204 c84 nf_tables_core.o
new: 2964 192 32 3188 c74i nf_tables_core.o
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Now that the rule trailer/end marker and the rcu head reside in the
same structure, we no longer need to save/restore the chain pointer
when performing/returning from a jump.
We can simply let the trace infra walk the evaluated rule until it
hits the end marker and then fetch the chain pointer from there.
When the rule is NULL (policy tracing), then chain and basechain
pointers were already identical, so just use the basechain.
This cuts size of jumpstack in half, from 256 to 128 bytes in 64bit,
scripts/stackusage says:
nf_tables_core.c:251 nft_do_chain 328 static
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Walk the rule headers until the trailer one (last_bit flag set) instead
of stopping at last_rule address.
This avoids the need to store the address when jumping to another chain.
This cuts size of jumpstack array by one third, on 64bit from
384 to 256 bytes. Still, stack usage is still quite large:
scripts/stackusage:
nf_tables_core.c:258 nft_do_chain 496 static
Next patch will also remove chain pointer.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nft_ct expression cannot be made builtin to nf_tables without also
forcing the conntrack itself to be builtin.
However, this can be avoided by splitting retrieval of a few
selector keys that only need to access the nf_conn structure,
i.e. no function calls to nf_conntrack code.
Many rulesets start with something like
"ct status established,related accept"
With this change, this no longer requires an indirect call, which
gives about 1.8% more throughput with a simple conntrack-enabled
forwarding test (retpoline thunk used).
Signed-off-by: Florian Westphal <fw@strlen.de>
If CONFIG_RETPOLINE is enabled nf_tables avoids indirect calls for
builtin expressions.
On newer cpus indirect calls do not go through the retpoline thunk
anymore, even for RETPOLINE=y builds.
Just like with the new tc retpoline wrappers:
Add a static key to skip the if / else if cascade if the cpu
does not require retpolines.
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
This new expression allows you to match on the inner headers that are
encapsulated by any of the existing tunneling protocols.
This expression parses the inner packet to set the link, network and
transport offsets, so the existing expressions (with a few updates) can
be reused to match on the inner headers.
The inner expression supports for different tunnel combinations such as:
- ethernet frame over IPv4/IPv6 packet, eg. VxLAN.
- IPv4/IPv6 packet over IPv4/IPv6 packet, eg. IPIP.
- IPv4/IPv6 packet over IPv4/IPv6 + transport header, eg. GRE.
- transport header (ESP or SCTP) over transport header (usually UDP)
The following fields are used to describe the tunnel protocol:
- flags, which describe how to parse the inner headers:
NFT_PAYLOAD_CTX_INNER_TUN, the tunnel provides its own header.
NFT_PAYLOAD_CTX_INNER_ETHER, the ethernet frame is available as inner header.
NFT_PAYLOAD_CTX_INNER_NH, the network header is available as inner header.
NFT_PAYLOAD_CTX_INNER_TH, the transport header is available as inner header.
For example, VxLAN sets on all of these flags. While GRE only sets on
NFT_PAYLOAD_CTX_INNER_NH and NFT_PAYLOAD_CTX_INNER_TH. Then, ESP over
UDP only sets on NFT_PAYLOAD_CTX_INNER_TH.
The tunnel description is composed of the following attributes:
- header size: in case the tunnel comes with its own header, eg. VxLAN.
- type: this provides a hint to userspace on how to delinearize the rule.
This is useful for VxLAN and Geneve since they run over UDP, since
transport does not provide a hint. This is also useful in case hardware
offload is ever supported. The type is not currently interpreted by the
kernel.
- expression: currently only payload supported. Follow up patch adds
also inner meta support which is required by autogenerated
dependencies. The exthdr expression should be supported too
at some point. There is a new inner_ops operation that needs to be
set on to allow to use an existing expression from the inner expression.
This patch adds a new NFT_PAYLOAD_TUN_HEADER base which allows to match
on the tunnel header fields, eg. vxlan vni.
The payload expression is embedded into nft_inner private area and this
private data area is passed to the payload inner eval function via
direct call.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nft_objref is needed to reference named objects, it makes
no sense to disable it.
Before:
text data bss dec filename
4014 424 0 4438 nft_objref.o
4174 1128 0 5302 nft_objref.ko
359351 15276 864 375491 nf_tables.ko
After:
text data bss dec filename
3815 408 0 4223 nft_objref.o
363161 15692 864 379717 nf_tables.ko
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
do not access info->pkt when info->trace is not 1.
nft_traceinfo is not initialized, except when tracing is enabled.
The 'nft_trace_enabled' static key cannot be used for this, we must
always check info->trace first.
Pass nft_pktinfo directly to avoid this.
Fixes: e34b9ed96c ("netfilter: nf_tables: avoid skb access on nf_stolen")
Reported-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When verdict is NF_STOLEN, the skb might have been freed.
When tracing is enabled, this can result in a use-after-free:
1. access to skb->nf_trace
2. access to skb->mark
3. computation of trace id
4. dump of packet payload
To avoid 1, keep a cached copy of skb->nf_trace in the
trace state struct.
Refresh this copy whenever verdict is != STOLEN.
Avoid 2 by skipping skb->mark access if verdict is STOLEN.
3 is avoided by precomputing the trace id.
Only dump the packet when verdict is not "STOLEN".
Reported-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Allow up to 16-byte comparisons with a new cmp fast version. Use two
64-bit words and calculate the mask representing the bits to be
compared. Make sure the comparison is 64-bit aligned and avoid
out-of-bound memory access on registers.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds a blob layout per chain to represent the ruleset in the
packet datapath.
size (unsigned long)
struct nft_rule_dp
struct nft_expr
...
struct nft_rule_dp
struct nft_expr
...
struct nft_rule_dp (is_last=1)
The new structure nft_rule_dp represents the rule in a more compact way
(smaller memory footprint) compared to the control-plane nft_rule
structure.
The ruleset blob is a read-only data structure. The first field contains
the blob size, then the rules containing expressions. There is a trailing
rule which is used by the tracing infrastructure which is equivalent to
the NULL rule marker in the previous representation. The blob size field
does not include the size of this trailing rule marker.
The ruleset blob is generated from the commit path.
This patch reuses the infrastructure available since 0cbc06b3fa
("netfilter: nf_tables: remove synchronize_rcu in commit phase") to
build the array of rules per chain.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Chain stats are updated from the Netfilter hook path which already run
under rcu read-size lock section.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add a new optional expression that tells you when last matching on a
given rule / set element element has happened.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This allows to change storage placement later on without changing readers.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
A typical use of bitwise expression is to mask out parts of an IP
address when matching on the network part only. Optimize for this common
use with a fast variant for NFT_BITWISE_BOOL-type expressions operating
on 32bit-sized values.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add a boolean indicating NFT_CMP_NEQ. To include it into the match
decision, it is sufficient to XOR it with the data comparison's result.
While being at it, store the mask that is calculated during expression
init and free the eval routine from having to recalculate it each time.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Separate bridge meta key from nft_meta to meta_bridge to avoid a
dependency between the bridge module and nft_meta when using the bridge
API available through include/linux/if_bridge.h
Signed-off-by: wenxu <wenxu@ucloud.cn>
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Based on 2 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 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 4122 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Check the result of dereferencing base_chain->stats, instead of result
of this_cpu_ptr with NULL.
base_chain->stats maybe be changed to NULL when a chain is updated and a
new NULL counter can be attached.
And we do not need to check returning of this_cpu_ptr since
base_chain->stats is from percpu allocator if it is non-NULL,
this_cpu_ptr returns a valid value.
And fix two sparse error by replacing rcu_access_pointer and
rcu_dereference with READ_ONCE under rcu_read_lock.
Thanks for Eric's help to finish this patch.
Fixes: 009240940e ("netfilter: nf_tables: don't assume chain stats are set when jumplabel is set")
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Empty case is fine and does not switch fall-through
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
With CONFIG_RETPOLINE its faster to add an if (ptr == &foo_func)
check and and use direct calls for all the built-in expressions.
~15% improvement in pathological cases.
checkpatch doesn't like the X macro due to the embedded return statement,
but the macro has a very limited scope so I don't think its a problem.
I would like to avoid bugs of the form
If (e->ops->eval == (unsigned long)nft_foo_eval)
nft_bar_eval();
and open-coded if ()/else if()/else cascade, thus the macro.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add the ability to set the security context of packets within the nf_tables framework.
Add a nft_object for holding security contexts in the kernel and manipulating packets on the wire.
Convert the security context strings at rule addition time to security identifiers.
This is the same behavior like in xt_SECMARK and offers better performance than computing it per packet.
Set the maximum security context length to 256.
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Currently nft uses inlined variants for common operations
such as 'ip saddr 1.2.3.4' instead of an indirect call.
Also handle meta get operations and lookups without indirect call,
both are builtin.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When depth of chain is bigger than NFT_JUMP_STACK_SIZE, the nft_do_chain
crashes. But there is no need to crash hard here.
Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Filling in the padding slot in the bpf structure as a bug fix in 'ne'
overlapped with actually using that padding area for something in
'net-next'.
Signed-off-by: David S. Miller <davem@davemloft.net>
The comment and trace_loginfo are not used anymore.
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
synchronize_rcu() is expensive.
The commit phase currently enforces an unconditional
synchronize_rcu() after incrementing the generation counter.
This is to make sure that a packet always sees a consistent chain, either
nft_do_chain is still using old generation (it will skip the newly added
rules), or the new one (it will skip old ones that might still be linked
into the list).
We could just remove the synchronize_rcu(), it would not cause a crash but
it could cause us to evaluate a rule that was removed and new rule for the
same packet, instead of either-or.
To resolve this, add rule pointer array holding two generations, the
current one and the future generation.
In commit phase, allocate the rule blob and populate it with the rules that
will be active in the new generation.
Then, make this rule blob public, replacing the old generation pointer.
Then the generation counter can be incremented.
nft_do_chain() will either continue to use the current generation
(in case loop was invoked right before increment), or the new one.
Suggested-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch fixes the following splat.
[118709.054937] BUG: using smp_processor_id() in preemptible [00000000] code: test/1571
[118709.054970] caller is nft_update_chain_stats.isra.4+0x53/0x97 [nf_tables]
[118709.054980] CPU: 2 PID: 1571 Comm: test Not tainted 4.17.0-rc6+ #335
[...]
[118709.054992] Call Trace:
[118709.055011] dump_stack+0x5f/0x86
[118709.055026] check_preemption_disabled+0xd4/0xe4
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
Netfilter updates for net-next
The following patchset contains Netfilter updates for your net-next
tree, they are:
1) Remove obsolete nf_log tracing from nf_tables, from Florian Westphal.
2) Add support for map lookups to numgen, random and hash expressions,
from Laura Garcia.
3) Allow to register nat hooks for iptables and nftables at the same
time. Patchset from Florian Westpha.
4) Timeout support for rbtree sets.
5) ip6_rpfilter works needs interface for link-local addresses, from
Vincent Bernat.
6) Add nf_ct_hook and nf_nat_hook structures and use them.
7) Do not drop packets on packets raceing to insert conntrack entries
into hashes, this is particularly a problem in nfqueue setups.
8) Address fallout from xt_osf separation to nf_osf, patches
from Florian Westphal and Fernando Mancera.
9) Remove reference to struct nft_af_info, which doesn't exist anymore.
From Taehee Yoo.
This batch comes with is a conflict between 25fd386e0b ("netfilter:
core: add missing __rcu annotation") in your tree and 2c205dd398
("netfilter: add struct nf_nat_hook and use it") coming in this batch.
This conflict can be solved by leaving the __rcu tag on
__netfilter_net_init() - added by 25fd386e0b - and remove all code
related to nf_nat_decode_session_hook - which is gone after
2c205dd398, as described by:
diff --cc net/netfilter/core.c
index e0ae4aae96f5,206fb2c4c319..168af54db975
--- a/net/netfilter/core.c
+++ b/net/netfilter/core.c
@@@ -611,7 -580,13 +611,8 @@@ const struct nf_conntrack_zone nf_ct_zo
EXPORT_SYMBOL_GPL(nf_ct_zone_dflt);
#endif /* CONFIG_NF_CONNTRACK */
- static void __net_init __netfilter_net_init(struct nf_hook_entries **e, int max)
-#ifdef CONFIG_NF_NAT_NEEDED
-void (*nf_nat_decode_session_hook)(struct sk_buff *, struct flowi *);
-EXPORT_SYMBOL(nf_nat_decode_session_hook);
-#endif
-
+ static void __net_init
+ __netfilter_net_init(struct nf_hook_entries __rcu **e, int max)
{
int h;
I can also merge your net-next tree into nf-next, solve the conflict and
resend the pull request if you prefer so.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
S390 bpf_jit.S is removed in net-next and had changes in 'net',
since that code isn't used any more take the removal.
TLS data structures split the TX and RX components in 'net-next',
put the new struct members from the bug fix in 'net' into the RX
part.
The 'net-next' tree had some reworking of how the ERSPAN code works in
the GRE tunneling code, overlapping with a one-line headroom
calculation fix in 'net'.
Overlapping changes in __sock_map_ctx_update_elem(), keep the bits
that read the prog members via READ_ONCE() into local variables
before using them.
Signed-off-by: David S. Miller <davem@davemloft.net>
nfnetlink tracing is available since nft 0.6 (June 2016).
Remove old nf_log based tracing to avoid rule counter in main loop.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nft_chain_stats_replace() and all other spots assume ->stats can be
NULL, but nft_update_chain_stats does not. It must do this check,
just because the jump label is set doesn't mean all basechains have stats
assigned.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>