The checksum is optional for UDP packets. However nf_reject would
previously require a valid checksum to elicit a response such as
ICMP_DEST_UNREACH.
Add some logic to nf_reject_verify_csum to determine if a UDP packet has
a zero checksum and should therefore not be verified.
Signed-off-by: Kevin Mitchell <kevmitch@arista.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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Merge tag 'selinux-pr-20201214' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux
Pull selinux updates from Paul Moore:
"While we have a small number of SELinux patches for v5.11, there are a
few changes worth highlighting:
- Change the LSM network hooks to pass flowi_common structs instead
of the parent flowi struct as the LSMs do not currently need the
full flowi struct and they do not have enough information to use it
safely (missing information on the address family).
This patch was discussed both with Herbert Xu (representing team
netdev) and James Morris (representing team
LSMs-other-than-SELinux).
- Fix how we handle errors in inode_doinit_with_dentry() so that we
attempt to properly label the inode on following lookups instead of
continuing to treat it as unlabeled.
- Tweak the kernel logic around allowx, auditallowx, and dontauditx
SELinux policy statements such that the auditx/dontauditx are
effective even without the allowx statement.
Everything passes our test suite"
* tag 'selinux-pr-20201214' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
lsm,selinux: pass flowi_common instead of flowi to the LSM hooks
selinux: Fix fall-through warnings for Clang
selinux: drop super_block backpointer from superblock_security_struct
selinux: fix inode_doinit_with_dentry() LABEL_INVALID error handling
selinux: allow dontauditx and auditallowx rules to take effect without allowx
selinux: fix error initialization in inode_doinit_with_dentry()
True to the message of commit v5.10-rc1-105-g46d6c5ae953c, _do_
actually make use of state->sk when possible, such as in the REJECT
modules.
Reported-by: Minqiang Chen <ptpt52@gmail.com>
Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Jan Engelhardt <jengelh@inai.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
As pointed out by Herbert in a recent related patch, the LSM hooks do
not have the necessary address family information to use the flowi
struct safely. As none of the LSMs currently use any of the protocol
specific flowi information, replace the flowi pointers with pointers
to the address family independent flowi_common struct.
Reported-by: Herbert Xu <herbert@gondor.apana.org.au>
Acked-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Enhance validation to support for reject from inet ingress chains.
Note that, reject from inet ingress and netdev ingress differ.
Reject packets from inet ingress are sent through ip_local_out() since
inet reject emulates the IP layer receive path. So the reject packet
follows to classic IP output and postrouting paths.
The reject action from netdev ingress assumes the packet not yet entered
the IP layer, so the reject packet is sent through dev_queue_xmit().
Therefore, reject packets from netdev ingress do not follow the classic
IP output and postrouting paths.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Adds reject skbuff creation helper functions to ipv4/6 nf_reject
infrastructure. Use these functions for reject verdict in bridge
family.
Can be reused by all different families that support reject and
will not inject the reject packet through ip local out.
Signed-off-by: Jose M. Guisado Gomez <guigom@riseup.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
REJECT statement can be only used in INPUT, FORWARD and OUTPUT
chains. This patch adds support of REJECT, both icmp and tcp
reset, at PREROUTING stage.
The need for this patch comes from the requirement of some
forwarding devices to reject traffic before the natting and
routing decisions.
The main use case is to be able to send a graceful termination
to legitimate clients that, under any circumstances, the NATed
endpoints are not available. This option allows clients to
decide either to perform a reconnection or manage the error in
their side, instead of just dropping the connection and let
them die due to timeout.
It is supported ipv4, ipv6 and inet families for nft
infrastructure.
Signed-off-by: Laura Garcia Liebana <nevola@gmail.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>
Some protocols have other means to verify the payload integrity
(AH, ESP, SCTP) while others are incompatible with nf_ip(6)_checksum
implementation because checksum is either optional or might be
partial (UDPLITE, DCCP, GRE). Because nf_ip(6)_checksum was used
to validate the packets, ip(6)tables REJECT rules were not capable
to generate ICMP(v6) errors for the protocols mentioned above.
This commit also fixes the incorrect pseudo-header protocol used
for IPv4 packets that carry other transport protocols than TCP or
UDP (pseudo-header used protocol 0 iso the proper value).
Signed-off-by: Alin Nastac <alin.nastac@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This pointer is going to be removed soon, so use the existing helpers in
more places to avoid noise when the removal happens.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
It seems like a historic accident that these return unsigned char *,
and in many places that means casts are required, more often than not.
Make these functions (skb_put, __skb_put and pskb_put) return void *
and remove all the casts across the tree, adding a (u8 *) cast only
where the unsigned char pointer was used directly, all done with the
following spatch:
@@
expression SKB, LEN;
typedef u8;
identifier fn = { skb_put, __skb_put };
@@
- *(fn(SKB, LEN))
+ *(u8 *)fn(SKB, LEN)
@@
expression E, SKB, LEN;
identifier fn = { skb_put, __skb_put };
type T;
@@
- E = ((T *)(fn(SKB, LEN)))
+ E = fn(SKB, LEN)
which actually doesn't cover pskb_put since there are only three
users overall.
A handful of stragglers were converted manually, notably a macro in
drivers/isdn/i4l/isdn_bsdcomp.c and, oddly enough, one of the many
instances in net/bluetooth/hci_sock.c. In the former file, I also
had to fix one whitespace problem spatch introduced.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This bit was introduced with commit 5a21232983 ("net: Support for
csum_bad in skbuff") to reduce the stack workload when processing RX
packets carrying a wrong Internet Checksum. Up to now, only one driver and
GRO core are setting it.
Suggested-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Otherwise, RST packets generated by ipt_REJECT always have mark 0 when
the routing is checked later in the same code path.
Fixes: e110861f86 ("net: add a sysctl to reflect the fwmark on replies")
Cc: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Pau Espin Pedrol <pau.espin@tessares.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nf_send_reset6 is not considering the L3 domain and lookups are sent
to the wrong table. For example consider the following output rule:
ip6tables -A OUTPUT -p tcp --dport 12345 -j REJECT --reject-with tcp-reset
using perf to analyze lookups via the fib6_table_lookup tracepoint shows:
swapper 0 [001] 248.787816: fib6:fib6_table_lookup: table 255 oif 0 iif 1 src 2100:1::3 dst 2100:1:
ffffffff81439cdc perf_trace_fib6_table_lookup ([kernel.kallsyms])
ffffffff814c1ce3 trace_fib6_table_lookup ([kernel.kallsyms])
ffffffff814c3e89 ip6_pol_route ([kernel.kallsyms])
ffffffff814c40d5 ip6_pol_route_output ([kernel.kallsyms])
ffffffff814e7b6f fib6_rule_action ([kernel.kallsyms])
ffffffff81437f60 fib_rules_lookup ([kernel.kallsyms])
ffffffff814e7c79 fib6_rule_lookup ([kernel.kallsyms])
ffffffff814c2541 ip6_route_output_flags ([kernel.kallsyms])
528 nf_send_reset6 ([nf_reject_ipv6])
The lookup is directed to table 255 rather than the table associated with
the device via the L3 domain. Update nf_send_reset6 to pull the L3 domain
from the dst currently attached to the skb.
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
ip6_route_output() never returns NULL, so it is not appropriate to
check if the return value is NULL.
Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This merge resolves conflicts with 75aec9df3a ("bridge: Remove
br_nf_push_frag_xmit_sk") as part of Eric Biederman's effort to improve
netns support in the network stack that reached upstream via David's
net-next tree.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Conflicts:
net/bridge/br_netfilter_hooks.c
This patch cleanses whitespace around arithmetical operators.
No changes detected by objdiff.
Signed-off-by: Ian Morris <ipm@chirality.org.uk>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Stop hidding the sk parameter with an inline helper function and make
all of the callers pass it, so that it is clear what the function is
doing.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
right now we store this in the nf_bridge_info struct, accessible
via skb->nf_bridge. This patch prepares removal of this pointer from skb:
Instead of using skb->nf_bridge->x, we use helpers to obtain the in/out
device (or ifindexes).
Followup patches to netfilter will then allow nf_bridge_info to be
obtained by a call into the br_netfilter core, rather than keeping a
pointer to it in sk_buff.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
make C=1 CF=-D__CHECK_ENDIAN__ shows following:
net/bridge/netfilter/nft_reject_bridge.c:65:50: warning: incorrect type in argument 3 (different base types)
net/bridge/netfilter/nft_reject_bridge.c:65:50: expected restricted __be16 [usertype] protocol [..]
net/bridge/netfilter/nft_reject_bridge.c:102:37: warning: cast from restricted __be16
net/bridge/netfilter/nft_reject_bridge.c:102:37: warning: incorrect type in argument 1 (different base types) [..]
net/bridge/netfilter/nft_reject_bridge.c:121:50: warning: incorrect type in argument 3 (different base types) [..]
net/bridge/netfilter/nft_reject_bridge.c:168:52: warning: incorrect type in argument 3 (different base types) [..]
net/bridge/netfilter/nft_reject_bridge.c:233:52: warning: incorrect type in argument 3 (different base types) [..]
Caused by two (harmless) errors:
1. htons() instead of ntohs()
2. __be16 for protocol in nf_reject_ipXhdr_put API, use u8 instead.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
tcp resets are never emitted if the packet that triggers the
reject/reset has an invalid checksum.
For icmp error responses there was no such check.
It allows to distinguish icmp response generated via
iptables -I INPUT -p udp --dport 42 -j REJECT
and those emitted by network stack (won't respond if csum is invalid,
REJECT does).
Arguably its possible to avoid this by using conntrack and only
using REJECT with -m conntrack NEW/RELATED.
However, this doesn't work when connection tracking is not in use
or when using nf_conntrack_checksum=0.
Furthermore, sending errors in response to invalid csums doesn't make
much sense so just add similar test as in nf_send_reset.
Validate csum if needed and only send the response if it is ok.
Reference: http://bugzilla.redhat.com/show_bug.cgi?id=1169829
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
netfilter/ipvs updates for net-next
The following patchset contains Netfilter updates for your net-next
tree, this includes the NAT redirection support for nf_tables, the
cgroup support for nft meta and conntrack zone support for the connlimit
match. Coming after those, a bunch of sparse warning fixes, missing
netns bits and cleanups. More specifically, they are:
1) Prepare IPv4 and IPv6 NAT redirect code to use it from nf_tables,
patches from Arturo Borrero.
2) Introduce the nf_tables redir expression, from Arturo Borrero.
3) Remove an unnecessary assignment in ip_vs_xmit/__ip_vs_get_out_rt().
Patch from Alex Gartrell.
4) Add nft_log_dereference() macro to the nf_log infrastructure, patch
from Marcelo Leitner.
5) Add some extra validation when registering logger families, also
from Marcelo.
6) Some spelling cleanups from stephen hemminger.
7) Fix sparse warning in nf_logger_find_get().
8) Add cgroup support to nf_tables meta, patch from Ana Rey.
9) A Kconfig fix for the new redir expression and fix sparse warnings in
the new redir expression.
10) Fix several sparse warnings in the netfilter tree, from
Florian Westphal.
11) Reduce verbosity when OOM in nfnetlink_log. User can basically do
nothing when this situation occurs.
12) Add conntrack zone support to xt_connlimit, again from Florian.
13) Add netnamespace support to the h323 conntrack helper, contributed
by Vasily Averin.
14) Remove unnecessary nul-pointer checks before free_percpu() and
module_put(), from Markus Elfring.
15) Use pr_fmt in nfnetlink_log, again patch from Marcelo Leitner.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
net/bridge/br_netfilter.c:870:6: symbol 'br_netfilter_enable' was not declared. Should it be static?
no; add include
net/ipv4/netfilter/nft_reject_ipv4.c:22:6: symbol 'nft_reject_ipv4_eval' was not declared. Should it be static?
yes
net/ipv6/netfilter/nf_reject_ipv6.c:16:6: symbol 'nf_send_reset6' was not declared. Should it be static?
no; add include
net/ipv6/netfilter/nft_reject_ipv6.c:22:6: symbol 'nft_reject_ipv6_eval' was not declared. Should it be static?
yes
net/netfilter/core.c:33:32: symbol 'nf_ipv6_ops' was not declared. Should it be static?
no; add include
net/netfilter/xt_DSCP.c:40:57: cast truncates bits from constant value (ffffff03 becomes 3)
net/netfilter/xt_DSCP.c:57:59: cast truncates bits from constant value (ffffff03 becomes 3)
add __force, 3 is what we want.
net/ipv4/netfilter/nf_log_arp.c:77:6: symbol 'nf_log_arp_packet' was not declared. Should it be static?
yes
net/ipv4/netfilter/nf_reject_ipv4.c:17:6: symbol 'nf_send_reset' was not declared. Should it be static?
no; add include
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
That can be reused by the reject bridge expression to build the reject
packet. The new functions are:
* nf_reject_ip6_tcphdr_get(): to sanitize and to obtain the TCP header.
* nf_reject_ip6hdr_put(): to build the IPv6 header.
* nf_reject_ip6_tcphdr_put(): to build the TCP header.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Move nf_send_reset() and nf_send_reset6() to nf_reject_ipv4 and
nf_reject_ipv6 respectively. This code is shared by x_tables and
nf_tables.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>