netfilter: nf_tables: Extend nft_expr_ops::dump callback parameters

Add a 'reset' flag just like with nft_object_ops::dump. This will be
useful to reset "anonymous stateful objects", e.g. simple rule counters.

No functional change intended.

Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nf_tables: do not reduce read-only expressions

Skip register tracking for expressions that perform read-only operations
on the registers. Define and use a cookie pointer NFT_REDUCE_READONLY to
avoid defining stubs for these expressions.

This patch re-enables register tracking which was disabled in ed5f85d42290
("netfilter: nf_tables: disable register tracking"). Follow up patches
add remaining register tracking for existing expressions.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nft_log: perform module load from nf_tables

modprobe calls from the nf_logger_find_get() API causes deadlock in very
special cases because they occur with the nf_tables transaction mutex held.

In the specific case of nf_log, deadlock is via:

A nf_tables -> transaction mutex -> nft_log -> modprobe -> nf_log_syslog \
-> pernet_ops rwsem -> wait for C
B netlink event -> rtnl_mutex -> nf_tables transaction mutex -> wait for A
C close() -> ip6mr_sk_done -> rtnl_mutex -> wait for B

Earlier patch added NFLOG/xt_LOG module softdeps to avoid the need to load
the backend module during a transaction.

For nft_log we would have to add a softdep for both nfnetlink_log or
nf_log_syslog, since we do not know in advance which of the two backends
are going to be configured.

This defers the modprobe op until after the transaction mutex is released.

Tested-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

treewide: rename nla_strlcpy to nla_strscpy.

Calls to nla_strlcpy are now replaced by calls to nla_strscpy which is the new
name of this function.

Signed-off-by: Francis Laniel <laniel_francis@privacyrequired.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

netfilter: Add MODULE_DESCRIPTION entries to kernel modules

The user tool modinfo is used to get information on kernel modules, including a
description where it is available.

This patch adds a brief MODULE_DESCRIPTION to netfilter kernel modules
(descriptions taken from Kconfig file or code comments)

Signed-off-by: Rob Gill <rrobgill@protonmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

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>

netfilter: nf_tables: add NFT_LOGLEVEL_* enumeration and use it

This is internal, not exposed through uapi, and although it maps with
userspace LOG_*, with the introduction of LOGLEVEL_AUDIT we are
incurring in namespace pollution.

This patch adds the NFT_LOGLEVEL_ enumeration and use it from nft_log.

Fixes: 1a893b44de45 ("netfilter: nf_tables: Add audit support to log statement")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>

netfilter: nf_tables: Add audit support to log statement

This extends log statement to support the behaviour achieved with
AUDIT target in iptables.

Audit logging is enabled via a pseudo log level 8. In this case any
other settings like log prefix are ignored since audit log format is
fixed.

Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nf_tables: add single table list for all families

Place all existing user defined tables in struct net *, instead of
having one list per family. This saves us from one level of indentation
in netlink dump functions.

Place pointer to struct nft_af_info in struct nft_table temporarily, as
we still need this to put back reference module reference counter on
table removal.

This patch comes in preparation for the removal of struct nft_af_info.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nft_log: restrict the log prefix length to 127

First, log prefix will be truncated to NF_LOG_PREFIXLEN-1, i.e. 127,
at nf_log_packet(), so the extra part is useless.

Second, after adding a log rule with a very very long prefix, we will
fail to dump the nft rules after this _special_ one, but acctually,
they do exist. For example:
# name_65000=$(printf "%0.sQ" {1..65000})
# nft add rule filter output log prefix "$name_65000"
# nft add rule filter output counter
# nft add rule filter output counter
# nft list chain filter output
table ip filter {
chain output {
type filter hook output priority 0; policy accept;
}
}

So now, restrict the log prefix length to NF_LOG_PREFIXLEN-1.

Fixes: 96518518cc41 ("netfilter: add nftables")
Signed-off-by: Liping Zhang <zlpnobody@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nf_tables: use hook state from xt_action_param structure

Don't copy relevant fields from hook state structure, instead use the
one that is already available in struct xt_action_param.

This patch also adds a set of new wrapper functions to fetch relevant
hook state structure fields.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nft_log: complete NFTA_LOG_FLAGS attr support

NFTA_LOG_FLAGS attribute is already supported, but the related
NF_LOG_XXX flags are not exposed to the userspace. So we cannot
explicitly enable log flags to log uid, tcp sequence, ip options
and so on, i.e. such rule "nft add rule filter output log uid"
is not supported yet.

So move NF_LOG_XXX macro definitions to the uapi/../nf_log.h. In
order to keep consistent with other modules, change NF_LOG_MASK to
refer to all supported log flags. On the other hand, add a new
NF_LOG_DEFAULT_MASK to refer to the original default log flags.

Finally, if user specify the unsupported log flags or NFTA_LOG_GROUP
and NFTA_LOG_FLAGS are set at the same time, report EINVAL to the
userspace.

Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nft_log: fix snaplen does not truncate packets

There's a similar problem in xt_NFLOG, and was fixed by commit 7643507fe8b5
("netfilter: xt_NFLOG: nflog-range does not truncate packets"). Only set
copy_len here does not work, so we should enable NF_LOG_F_COPY_LEN also.

Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nft_log: check the validity of log level

User can specify the log level larger than 7(debug level) via
nfnetlink, this is invalid. So in this case, we should report
EINVAL to the userspace.

Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nft_log: fix possible memory leak if log expr init fail

Suppose that we specify the NFTA_LOG_PREFIX, then NFTA_LOG_LEVEL
and NFTA_LOG_GROUP are specified together or nf_logger_find_get
call returns fail, i.e. expr init fail, memory leak will happen.

Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nf_log: handle NFPROTO_INET properly in nf_logger_[find_get|put]

When we request NFPROTO_INET, it means both NFPROTO_IPV4 and NFPROTO_IPV6.

Signed-off-by: Liping Zhang <liping.zhang@spreadtrum.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nf_tables: Use pkt->net instead of computing net from the passed net_devices

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nf_tables: kill nft_pktinfo.ops

- Add nft_pktinfo.pf to replace ops->pf
- Add nft_pktinfo.hook to replace ops->hooknum

This simplifies the code, makes it more readable, and likely reduces
cache line misses. Maintainability is enhanced as the details of
nft_hook_ops are of no concern to the recpients of nft_pktinfo.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nf_tables: get rid of NFT_REG_VERDICT usage

Replace the array of registers passed to expressions by a struct nft_regs,
containing the verdict as a seperate member, which aliases to the
NFT_REG_VERDICT register.

This is needed to seperate the verdict from the data registers completely,
so their size can be changed.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: Use LOGLEVEL_<FOO> defines

Use the #defines where appropriate.

Miscellanea:

Add explicit #include <linux/kernel.h> where it was not
previously used so that these #defines are a bit more
explicitly defined instead of indirectly included via:
module.h->moduleparam.h->kernel.h

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nft_log: fix coccinelle warnings

net/netfilter/nft_log.c:79:44-45: Unneeded semicolon

Removes unneeded semicolon.

Generated by: scripts/coccinelle/misc/semicolon.cocci

CC: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nft_log: complete logging support

Use the unified nf_log_packet() interface that allows us explicit
logger selection through the nf_loginfo structure.

If you specify the group attribute, this means you want to receive
logging messages through nfnetlink_log. In that case, the snaplen
and qthreshold attributes allows you to tune internal aspects of
the netlink logging infrastructure.

On the other hand, if the level is specified, then the plain text
format through the kernel logging ring is used instead, which is
also used by default if neither group nor level are indicated.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nft_log: request explicit logger when loading rules

This includes the special handling for NFPROTO_INET. There is
no real inet logger since we don't see packets of this family.
However, rules are loaded using this special family type. So
let's just request both IPV4 and IPV6 loggers.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nf_tables: restore context for expression destructors

In order to fix set destruction notifications and get rid of unnecessary
members in private data structures, pass the context to expressions'
destructor functions again.

In order to do so, replace various members in the nft_rule_trans structure
by the full context.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nf_tables: fix log/queue expressions for NFPROTO_INET

The log and queue expressions both store the family during ->init() and
use it to deliver packets. This is wrong when used in NFPROTO_INET since
they should both deliver to the actual AF of the packet, not the dummy
NFPROTO_INET.

Use the family from the hook ops to fix this.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nf_tables: add hook ops to struct nft_pktinfo

Multi-family tables need the AF from the hook ops. Add a pointer to the
hook ops and replace usage of the hooknum member in struct nft_pktinfo.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: nf_tables: expression ops overloading

Split the expression ops into two parts and support overloading of
the runtime expression ops based on the requested function through
a ->select_ops() callback.

This can be used to provide optimized implementations, for instance
for loading small aligned amounts of data from the packet or inlining
frequently used operations into the main evaluation loop.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

netfilter: add nftables

This patch adds nftables which is the intended successor of iptables.
This packet filtering framework reuses the existing netfilter hooks,
the connection tracking system, the NAT subsystem, the transparent
proxying engine, the logging infrastructure and the userspace packet
queueing facilities.

In a nutshell, nftables provides a pseudo-state machine with 4 general
purpose registers of 128 bits and 1 specific purpose register to store
verdicts. This pseudo-machine comes with an extensible instruction set,
a.k.a. "expressions" in the nftables jargon. The expressions included
in this patch provide the basic functionality, they are:

* bitwise: to perform bitwise operations.
* byteorder: to change from host/network endianess.
* cmp: to compare data with the content of the registers.
* counter: to enable counters on rules.
* ct: to store conntrack keys into register.
* exthdr: to match IPv6 extension headers.
* immediate: to load data into registers.
* limit: to limit matching based on packet rate.
* log: to log packets.
* meta: to match metainformation that usually comes with the skbuff.
* nat: to perform Network Address Translation.
* payload: to fetch data from the packet payload and store it into
registers.
* reject (IPv4 only): to explicitly close connection, eg. TCP RST.

Using this instruction-set, the userspace utility 'nft' can transform
the rules expressed in human-readable text representation (using a
new syntax, inspired by tcpdump) to nftables bytecode.

nftables also inherits the table, chain and rule objects from
iptables, but in a more configurable way, and it also includes the
original datatype-agnostic set infrastructure with mapping support.
This set infrastructure is enhanced in the follow up patch (netfilter:
nf_tables: add netlink set API).

This patch includes the following components:

* the netlink API: net/netfilter/nf_tables_api.c and
include/uapi/netfilter/nf_tables.h
* the packet filter core: net/netfilter/nf_tables_core.c
* the expressions (described above): net/netfilter/nft_*.c
* the filter tables: arp, IPv4, IPv6 and bridge:
net/ipv4/netfilter/nf_tables_ipv4.c
net/ipv6/netfilter/nf_tables_ipv6.c
net/ipv4/netfilter/nf_tables_arp.c
net/bridge/netfilter/nf_tables_bridge.c
* the NAT table (IPv4 only):
net/ipv4/netfilter/nf_table_nat_ipv4.c
* the route table (similar to mangle):
net/ipv4/netfilter/nf_table_route_ipv4.c
net/ipv6/netfilter/nf_table_route_ipv6.c
* internal definitions under:
include/net/netfilter/nf_tables.h
include/net/netfilter/nf_tables_core.h
* It also includes an skeleton expression:
net/netfilter/nft_expr_template.c
and the preliminary implementation of the meta target
net/netfilter/nft_meta_target.c

It also includes a change in struct nf_hook_ops to add a new
pointer to store private data to the hook, that is used to store
the rule list per chain.

This patch is based on the patch from Patrick McHardy, plus merged
accumulated cleanups, fixes and small enhancements to the nftables
code that has been done since 2009, which are:

From Patrick McHardy:
* nf_tables: adjust netlink handler function signatures
* nf_tables: only retry table lookup after successful table module load
* nf_tables: fix event notification echo and avoid unnecessary messages
* nft_ct: add l3proto support
* nf_tables: pass expression context to nft_validate_data_load()
* nf_tables: remove redundant definition
* nft_ct: fix maxattr initialization
* nf_tables: fix invalid event type in nf_tables_getrule()
* nf_tables: simplify nft_data_init() usage
* nf_tables: build in more core modules
* nf_tables: fix double lookup expression unregistation
* nf_tables: move expression initialization to nf_tables_core.c
* nf_tables: build in payload module
* nf_tables: use NFPROTO constants
* nf_tables: rename pid variables to portid
* nf_tables: save 48 bits per rule
* nf_tables: introduce chain rename
* nf_tables: check for duplicate names on chain rename
* nf_tables: remove ability to specify handles for new rules
* nf_tables: return error for rule change request
* nf_tables: return error for NLM_F_REPLACE without rule handle
* nf_tables: include NLM_F_APPEND/NLM_F_REPLACE flags in rule notification
* nf_tables: fix NLM_F_MULTI usage in netlink notifications
* nf_tables: include NLM_F_APPEND in rule dumps

From Pablo Neira Ayuso:
* nf_tables: fix stack overflow in nf_tables_newrule
* nf_tables: nft_ct: fix compilation warning
* nf_tables: nft_ct: fix crash with invalid packets
* nft_log: group and qthreshold are 2^16
* nf_tables: nft_meta: fix socket uid,gid handling
* nft_counter: allow to restore counters
* nf_tables: fix module autoload
* nf_tables: allow to remove all rules placed in one chain
* nf_tables: use 64-bits rule handle instead of 16-bits
* nf_tables: fix chain after rule deletion
* nf_tables: improve deletion performance
* nf_tables: add missing code in route chain type
* nf_tables: rise maximum number of expressions from 12 to 128
* nf_tables: don't delete table if in use
* nf_tables: fix basechain release

From Tomasz Bursztyka:
* nf_tables: Add support for changing users chain's name
* nf_tables: Change chain's name to be fixed sized
* nf_tables: Add support for replacing a rule by another one
* nf_tables: Update uapi nftables netlink header documentation

From Florian Westphal:
* nft_log: group is u16, snaplen u32

From Phil Oester:
* nf_tables: operational limit match

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>