"When trying to add a rule which contains an anonymous chain to a
non-existent chain, string_misspell_update() is called with a NULL
string because the anonymous chain has no name. Avoid this by making the
function NULL-pointer tolerant."
Fixes: c330152b7f777 ("src: support for implicit chain bindings") Reported-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Sam James [Thu, 24 Feb 2022 19:45:43 +0000 (19:45 +0000)]
build: explicitly pass --version-script to linker
--version-script is a linker option, so let's use -Wl, so that
libtool handles it properly. It seems like the previous method gets silently
ignored with GNU libtool in some cases(?) and downstream in Gentoo,
we had to apply this change to make the build work with slibtool anyway.
But it's indeed correct in any case, so let's swap.
Signed-off-by: Sam James <sam@gentoo.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Sam James [Thu, 24 Feb 2022 19:45:42 +0000 (19:45 +0000)]
libnftables.map: export new nft_ctx_{get,set}_optimize API
[ Remove incorrect symbol names were exported via .map file ]
Without this, we're not explicitly saying this is part of the
public API.
This new API was added in 1.0.2 and is used by e.g. the main
nft binary. Noticed when fixing the version-script option
(separate patch) which picked up this problem when .map
was missing symbols (related to when symbol visibility
options get set).
Signed-off-by: Sam James <sam@gentoo.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Florian Westphal [Tue, 22 Feb 2022 12:51:09 +0000 (13:51 +0100)]
tests: add test case for flowtable with owner flag
BUG: KASAN: use-after-free in nf_hook_entries_grow+0x675/0x980
Read of size 4 at ... nft/19662
nf_hook_entries_grow+0x675/0x980
This is fixed by kernel commit 6069da443bf
("netfilter: nf_tables: unregister flowtable hooks on netns exit").
The test case here uses owner flag, netlink event handler doesn't
release the flowtable, next attempt to add one then causes uaf because
of dangling ingress hook reference.
examples: compile with `make check' and add AM_CPPFLAGS
Compile examples via `make check' like libnftnl does. Use AM_CPPFLAGS to
specify local headers via -I.
Unfortunately, `make distcheck' did not catch this compile time error in
my system, since it was using the nftables/libnftables.h file of the
previous nftables release.
Fixes: 5b364657a35f ("build: missing SUBIRS update") Fixes: caf2a6ad2d22 ("examples: add libnftables example program") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Eugene Crosser [Thu, 9 Dec 2021 18:26:06 +0000 (19:26 +0100)]
netlink: Use abort() in case of netlink_abi_error
Library functions should not use exit(), application that uses the
library may contain error handling path, that cannot be executed if
library functions calls exit(). For truly fatal errors, using abort() is
more acceptable than exit().
Signed-off-by: Eugene Crosser <crosser@average.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Jeremy Sowden [Sat, 15 Jan 2022 18:27:06 +0000 (18:27 +0000)]
src: add a helper that returns a payload dependency for a particular base
Currently, with only one base and dependency stored this is superfluous,
but it will become more useful when the next commit adds support for
storing a payload for every base.
Remove redundant `ctx->pbase` check.
Signed-off-by: Jeremy Sowden <jeremy@azazel.net> Signed-off-by: Florian Westphal <fw@strlen.de>
Florian Westphal [Sat, 15 Jan 2022 19:00:49 +0000 (20:00 +0100)]
src: silence compiler warnings
cache.c:504:22: warning: ‘chain’ may be used uninitialized in this function [-Wmaybe-uninitialized]
cache.c:504:22: warning: ‘table’ may be used uninitialized in this function [-Wmaybe-uninitialized]
erec.c:128:16: warning: ‘line’ may be used uninitialized in this function [-Wmaybe-uninitialized]
optimize.c:524:9: warning: ‘line’ may be used uninitialized in this function [-Wmaybe-uninitialized]
Fixes: 8ad4056e9182 ("erec: expose print_location() and line_location()") Fixes: afbd102211dc ("src: do not use the nft_cache_filter object from mnl.c") Fixes: fb298877ece2 ("src: add ruleset optimization infrastructure") Signed-off-by: Florian Westphal <fw@strlen.de>
src: 'nft list chain' prints anonymous chains correctly
If the user is requesting a chain listing, e.g. nft list chain x y
and a rule refers to an anonymous chain that cannot be found in the cache,
then fetch such anonymous chain and its ruleset.
Closes: https://bugzilla.netfilter.org/show_bug.cgi?id=1577 Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
optimize: merge rules with same selectors into a concatenation
This patch extends the ruleset optimization infrastructure to collapse
several rules with the same selectors into a concatenation.
Transform:
meta iifname eth1 ip saddr 1.1.1.1 ip daddr 2.2.2.3 accept
meta iifname eth1 ip saddr 1.1.1.2 ip daddr 2.2.2.5 accept
meta iifname eth2 ip saddr 1.1.1.3 ip daddr 2.2.2.6 accept
into:
meta iifname . ip saddr . ip daddr { eth1 . 1.1.1.1 . 2.2.2.6, eth1 . 1.1.1.2 . 2.2.2.5 , eth1 . 1.1.1.3 . 2.2.2.6 } accept
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch adds a new -o/--optimize option to enable ruleset
optimization.
You can combine this option with the dry run mode (--check) to review
the proposed ruleset updates without actually loading the ruleset, e.g.
# nft -c -o -f ruleset.test
Merging:
ruleset.nft:16:3-37: ip daddr 192.168.0.1 counter accept
ruleset.nft:17:3-37: ip daddr 192.168.0.2 counter accept
ruleset.nft:18:3-37: ip daddr 192.168.0.3 counter accept
into:
ip daddr { 192.168.0.1, 192.168.0.2, 192.168.0.3 } counter packets 0 bytes 0 accept
This infrastructure collects the common statements that are used in
rules, then it builds a matrix of rules vs. statements. Then, it looks
for common statements in consecutive rules which allows to merge rules.
This ruleset optimization always performs an implicit dry run to
validate that the original ruleset is correct. Then, on a second pass,
it performs the ruleset optimization and add the rules into the kernel
(unless --check has been specified by the user).
From libnftables perspective, there is a new API to enable
this feature:
This patch adds support for the first optimization: Collapse a linear
list of rules matching on a single selector into a set as exposed in the
example above.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The error reporting infrastructure performs a fseek() on the file
descriptor which does not work in this case since the data from the
descriptor has been already consumed.
This patch adds a new stdin input descriptor to perform this special
handling which consists on re-routing this request through the buffer
functions.
Fixes: 935f82e7dd49 ("Support 'nft -f -' to read from stdin") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
There are several places where we check whether `ctx->pdctx.pbase`
equal to `PROTO_BASE_INVALID` and don't bother trying to free the
dependency if so. However, these checks are redundant.
In `payload_match_expand` and `trace_gen_stmts`, we skip a call to
`payload_dependency_kill`, but that calls `payload_dependency_exists` to check a
dependency exists before doing anything else.
In `ct_meta_common_postprocess`, we skip an open-coded equivalent to
`payload_dependency_kill` which performs some different checks, but the
first is the same: a call to `payload_dependency_exists`.
Therefore, we can drop the redundant checks and simplify the flow-
control in the functions.
Signed-off-by: Jeremy Sowden <jeremy@azazel.net> Signed-off-by: Florian Westphal <fw@strlen.de>
Jeremy Sowden [Tue, 21 Dec 2021 19:36:49 +0000 (19:36 +0000)]
tests: py: fix inet/ip_tcp.t test
Contrary to the comment and expected output, nft does _not_ eliminate
the redundant `ip protocol` expression from the second test. Dependency
elimination requires a higher level expression. `ip saddr` cannot lead
to the elimination of `ip protocol` since they are both L3 expressions.
`tcp dport` cannot because although `ip saddr` and `ip protocol` both
imply that the L3 protocol is `ip`, only protocol matches are stored as
dependencies, so the redundancy is not apparent, and in fact,
`payload_may_dependency_kill` explicitly checks for the combination of
inet, bridge or netdev family, L4 expression and L3 ipv4 or ipv6
dependency and returns false.
Correct the expected output and comment.
Signed-off-by: Jeremy Sowden <jeremy@azazel.net> Signed-off-by: Florian Westphal <fw@strlen.de>
Florian Westphal [Tue, 11 Jan 2022 11:08:59 +0000 (12:08 +0100)]
evaluate: attempt to set_eval flag if dynamic updates requested
When passing no upper size limit, the dynset expression forces
an internal 64k upperlimit.
In some cases, this can result in 'nft -f' to restore the ruleset.
Avoid this by always setting the EVAL flag on a set definition when
we encounter packet-path update attempt in the batch.
Reported-by: Yi Chen <yiche@redhat.com> Suggested-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Florian Westphal <fw@strlen.de>
Jeremy Sowden [Thu, 16 Dec 2021 16:37:20 +0000 (16:37 +0000)]
build: remove scanner.c and parser_bison.c with `maintainer-clean`
automake recommends shipping the output of bison and lex in distribution
tar-balls and runs bison and lex during `make dist` (this has the
advantage that end-users don't need to have bison or lex installed to
compile the software). Accordingly, automake also recommends removing
these files with `make maintainer-clean` and generates rules to do so.
Therefore, remove scanner.c and parser_bison.c from `CLEANFILES`.
Signed-off-by: Jeremy Sowden <jeremy@azazel.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Jeremy Sowden [Wed, 15 Dec 2021 18:44:40 +0000 (18:44 +0000)]
build: fix autoconf warnings
autoconf complains about three obsolete macros.
`AC_CONFIG_HEADER` has been superseded by `AC_CONFIG_HEADERS`, so
replace it.
`AM_PROG_LEX` calls `AC_PROG_LEX` with no arguments, but this usage is
deprecated. The only difference between `AM_PROG_LEX` and `AC_PROG_LEX`
is that the former defines `$LEX` as "./build-aux/missing lex" if no lex
is found to ensure a useful error is reported when make is run. How-
ever, the configure script checks that we have a working lex and exits
with an error if none is available, so `$LEX` will never be called and
we can replace `AM_PROG_LEX` with `AC_PROG_LEX`.
`AM_PROG_LIBTOOL` has been superseded by `LT_INIT`, which is already in
configure.ac, so remove it.
We can also replace `AC_DISABLE_STATIC` with an argument to `LT_INIT`.
Signed-off-by: Jeremy Sowden <jeremy@azazel.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Jeremy Sowden [Sat, 11 Dec 2021 18:55:25 +0000 (18:55 +0000)]
evaluate: reject: support ethernet as L2 protocol for inet table
When we are evaluating a `reject` statement in the `inet` family, we may
have `ether` and `ip` or `ip6` as the L2 and L3 protocols in the
evaluation context:
The reason it fails is that the ethernet protocol numbers for IPv4 and
IPv6 (`ETH_P_IP` and `ETH_P_IPV6`) do not match `NFPROTO_IPV4` and
`NFPROTO_IPV6`. Add support for the ethernet protocol numbers.
Replace the current `BUG("unsupported family")` error message with
something more informative that tells the user to provide an explicit
reject option.
Jeremy Sowden [Sat, 11 Dec 2021 18:55:23 +0000 (18:55 +0000)]
proto: short-circuit loops over upper protocols
Each `struct proto_desc` contains a fixed-size array of higher layer
protocols. Only the first few are not NULL. Therefore, we can stop
iterating over the array once we reach a NULL member.
Signed-off-by: Jeremy Sowden <jeremy@azazel.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
First binop masks out unwanted parts of the 16-bit field.
Second binop needs to left-shift so that lookups in the set will work.
When decoding, the first binop is removed after the exthdr load
has been adjusted accordingly. Constant propagation adjusts the
shift-value to 0 on removal. This change then gets rid of the
shift-by-0 entirely.
After this change, 'frag frag-off @s4' input is shown as-is.
Štěpán Němec [Wed, 1 Dec 2021 11:12:00 +0000 (12:12 +0100)]
tests: shell: better parameters for the interval stack overflow test
Wider testing has shown that 128 kB stack is too low (e.g. for systems
with 64 kB page size), leading to false failures in some environments.
Based on results from a matrix of RHEL 8 and RHEL 9 systems across
x86_64, aarch64, ppc64le and s390x architectures as well as some
anecdotal testing of other Linux distros on x86_64 machines, 400 kB
seems safe: the normal nft stack (which should stay constant during
this test) on all tested systems doesn't exceed 200 kB (stays around
100 kB on typical systems with 4 kB page size), while always growing
beyond 500 kB in the failing case (nftables before baecd1cf2685) with
the increased set size.
Fixes: d8ccad2a2b73 ("tests: cover baecd1cf2685 ("segtree: Fix segfault when restoring a huge interval set")") Signed-off-by: Štěpán Němec <snemec@redhat.com> Signed-off-by: Phil Sutter <phil@nwl.cc>
Its always 0, so remove it.
Looks like this was intended to support variable options that have
array-like members, but so far this isn't implemented, better remove
dead code and implement it properly when such support is needed.