linux.git/net/netfilter, branch v5.3-rc2

net: flow_offload: add flow_block structure and use it

2019-07-20T04:27:45+00:00

This object stores the flow block callbacks that are attached to this
block. Update flow_block_cb_lookup() to take this new object.

This patch restores the block sharing feature.

Fixes: da3eeb904ff4 ("net: flow_offload: add list handling functions")
Signed-off-by: Pablo Neira Ayuso 
Acked-by: Jiri Pirko 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf

2019-07-20T04:25:10+00:00

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

1) Fix a deadlock when module is requested via netlink_bind()
   in nfnetlink, from Florian Westphal.

2) Fix ipt_rpfilter and ip6t_rpfilter with VRF, from Miaohe Lin.

3) Skip master comparison in SIP helper to fix expectation clash
   under two valid scenarios, from xiao ruizhu.

4) Remove obsolete comments in nf_conntrack codebase, from
   Yonatan Goldschmidt.

5) Fix redirect extension module autoload, from Christian Hesse.

6) Fix incorrect mssg option sent to client in synproxy,
   from Fernando Fernandez.

7) Fix incorrect window calculations in TCP conntrack, from
   Florian Westphal.

8) Don't bail out when updating basechain policy due to recent
   offload works, also from Florian.

9) Allow symhash to use modulus 1 as other hash extensions do,
   from Laura.Garcia.

10) Missing NAT chain module autoload for the inet family,
    from Phil Sutter.

11) Fix missing adjustment of TCP RST packet in synproxy,
    from Fernando Fernandez.

12) Skip EAGAIN path when nft_meta_bridge is built-in or
    not selected.

13) Conntrack bridge does not depend on nf_tables_bridge.

14) Turn NF_TABLES_BRIDGE into tristate to fix possible
    link break of nft_meta_bridge, from Arnd Bergmann.
====================

Signed-off-by: David S. Miller

netfilter: bridge: make NF_TABLES_BRIDGE tristate

2019-07-19T16:08:14+00:00

The new nft_meta_bridge code fails to link as built-in when NF_TABLES
is a loadable module.

net/bridge/netfilter/nft_meta_bridge.o: In function `nft_meta_bridge_get_eval':
nft_meta_bridge.c:(.text+0x1e8): undefined reference to `nft_meta_get_eval'
net/bridge/netfilter/nft_meta_bridge.o: In function `nft_meta_bridge_get_init':
nft_meta_bridge.c:(.text+0x468): undefined reference to `nft_meta_get_init'
nft_meta_bridge.c:(.text+0x49c): undefined reference to `nft_parse_register'
nft_meta_bridge.c:(.text+0x4cc): undefined reference to `nft_validate_register_store'
net/bridge/netfilter/nft_meta_bridge.o: In function `nft_meta_bridge_module_exit':
nft_meta_bridge.c:(.exit.text+0x14): undefined reference to `nft_unregister_expr'
net/bridge/netfilter/nft_meta_bridge.o: In function `nft_meta_bridge_module_init':
nft_meta_bridge.c:(.init.text+0x14): undefined reference to `nft_register_expr'
net/bridge/netfilter/nft_meta_bridge.o:(.rodata+0x60): undefined reference to `nft_meta_get_dump'
net/bridge/netfilter/nft_meta_bridge.o:(.rodata+0x88): undefined reference to `nft_meta_set_eval'

This can happen because the NF_TABLES_BRIDGE dependency itself is just a
'bool'.  Make the symbol a 'tristate' instead so Kconfig can propagate the
dependencies correctly.

Fixes: 30e103fe24de ("netfilter: nft_meta: move bridge meta keys into nft_meta_bridge")
Signed-off-by: Arnd Bergmann 
Signed-off-by: Pablo Neira Ayuso

proc/sysctl: add shared variables for range check

2019-07-19T00:08:07+00:00

In the sysctl code the proc_dointvec_minmax() function is often used to
validate the user supplied value between an allowed range.  This
function uses the extra1 and extra2 members from struct ctl_table as
minimum and maximum allowed value.

On sysctl handler declaration, in every source file there are some
readonly variables containing just an integer which address is assigned
to the extra1 and extra2 members, so the sysctl range is enforced.

The special values 0, 1 and INT_MAX are very often used as range
boundary, leading duplication of variables like zero=0, one=1,
int_max=INT_MAX in different source files:

    $ git grep -E '\.extra[12].*&(zero|one|int_max)' |wc -l
    248

Add a const int array containing the most commonly used values, some
macros to refer more easily to the correct array member, and use them
instead of creating a local one for every object file.

This is the bloat-o-meter output comparing the old and new binary
compiled with the default Fedora config:

    # scripts/bloat-o-meter -d vmlinux.o.old vmlinux.o
    add/remove: 2/2 grow/shrink: 0/2 up/down: 24/-188 (-164)
    Data                                         old     new   delta
    sysctl_vals                                    -      12     +12
    __kstrtab_sysctl_vals                          -      12     +12
    max                                           14      10      -4
    int_max                                       16       -     -16
    one                                           68       -     -68
    zero                                         128      28    -100
    Total: Before=20583249, After=20583085, chg -0.00%

[mcroce@redhat.com: tipc: remove two unused variables]
  Link: http://lkml.kernel.org/r/20190530091952.4108-1-mcroce@redhat.com
[akpm@linux-foundation.org: fix net/ipv6/sysctl_net_ipv6.c]
[arnd@arndb.de: proc/sysctl: make firmware loader table conditional]
  Link: http://lkml.kernel.org/r/20190617130014.1713870-1-arnd@arndb.de
[akpm@linux-foundation.org: fix fs/eventpoll.c]
Link: http://lkml.kernel.org/r/20190430180111.10688-1-mcroce@redhat.com
Signed-off-by: Matteo Croce 
Signed-off-by: Arnd Bergmann 
Acked-by: Kees Cook 
Reviewed-by: Aaron Tomlin 
Cc: Matthew Wilcox 
Cc: Stephen Rothwell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

netfilter: nft_meta: skip EAGAIN if nft_meta_bridge is not a module

2019-07-18T18:55:54+00:00

If it is a module, request this module. Otherwise, if it is compiled
built-in or not selected, skip this.

Fixes: 0ef1efd1354d ("netfilter: nf_tables: force module load in case select_ops() returns -EAGAIN")
Signed-off-by: Pablo Neira Ayuso

netfilter: synproxy: fix rst sequence number mismatch

2019-07-18T18:55:53+00:00

14:51:00.024418 IP 192.168.122.1.41462 > netfilter.90: Flags [S], seq
4023580551,
14:51:00.024454 IP netfilter.90 > 192.168.122.1.41462: Flags [S.], seq
727560212, ack 4023580552,
14:51:00.024524 IP 192.168.122.1.41462 > netfilter.90: Flags [.], ack 1,

Note: here, synproxy will send a SYN to the real server, as the 3whs was
completed sucessfully. Instead of a syn/ack that we can intercept, we instead
received a reset packet from the real backend, that we forward to the original
client. However, we don't use the correct sequence number, so the reset is not
effective in closing the connection coming from the client.

14:51:00.024550 IP netfilter.90 > 192.168.122.1.41462: Flags [R.], seq
3567407084,
14:51:00.231196 IP 192.168.122.1.41462 > netfilter.90: Flags [.], ack 1,
14:51:00.647911 IP 192.168.122.1.41462 > netfilter.90: Flags [.], ack 1,
14:51:01.474395 IP 192.168.122.1.41462 > netfilter.90: Flags [.], ack 1,

Fixes: 48b1de4c110a ("netfilter: add SYNPROXY core/target")
Signed-off-by: Fernando Fernandez Mancera 
Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: Support auto-loading for inet nat

2019-07-18T18:19:02+00:00

Trying to create an inet family nat chain would not cause
nft_chain_nat.ko module to auto-load due to missing module alias. Add a
proper one with hard-coded family value 1 for the pseudo-family
NFPROTO_INET.

Fixes: d164385ec572 ("netfilter: nat: add inet family nat support")
Signed-off-by: Phil Sutter 
Signed-off-by: Pablo Neira Ayuso

netfilter: nft_hash: fix symhash with modulus one

2019-07-16T11:17:03+00:00

The rule below doesn't work as the kernel raises -ERANGE.

nft add rule netdev nftlb lb01 ip daddr set \
	symhash mod 1 map { 0 : 192.168.0.10 } fwd to "eth0"

This patch allows to use the symhash modulus with one
element, in the same way that the other types of hashes and
algorithms that uses the modulus parameter.

Signed-off-by: Laura Garcia Liebana 
Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: don't fail when updating base chain policy

2019-07-16T11:17:02+00:00

The following nftables test case fails on nf-next:

tests/shell/run-tests.sh tests/shell/testcases/transactions/0011chain_0

The test case contains:
add chain x y { type filter hook input priority 0; }
add chain x y { policy drop; }"

The new test
if (chain->flags ^ flags)
	return -EOPNOTSUPP;

triggers here, because chain->flags has NFT_BASE_CHAIN set, but flags
is 0 because no flag attribute was present in the policy update.

Just fetch the current flag settings of a pre-existing chain in case
userspace did not provide any.

Fixes: c9626a2cbdb20 ("netfilter: nf_tables: add hardware offload support")
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: conntrack: always store window size un-scaled

2019-07-16T11:17:02+00:00

Jakub Jankowski reported following oddity:

After 3 way handshake completes, timeout of new connection is set to
max_retrans (300s) instead of established (5 days).

shortened excerpt from pcap provided:
25.070622 IP (flags [DF], proto TCP (6), length 52)
10.8.5.4.1025 > 10.8.1.2.80: Flags [S], seq 11, win 64240, [wscale 8]
26.070462 IP (flags [DF], proto TCP (6), length 48)
10.8.1.2.80 > 10.8.5.4.1025: Flags [S.], seq 82, ack 12, win 65535, [wscale 3]
27.070449 IP (flags [DF], proto TCP (6), length 40)
10.8.5.4.1025 > 10.8.1.2.80: Flags [.], ack 83, win 512, length 0

Turns out the last_win is of u16 type, but we store the scaled value:
512 << 8 (== 0x20000) becomes 0 window.

The Fixes tag is not correct, as the bug has existed forever, but
without that change all that this causes might cause is to mistake a
window update (to-nonzero-from-zero) for a retransmit.

Fixes: fbcd253d2448b8 ("netfilter: conntrack: lower timeout to RETRANS seconds if window is 0")
Reported-by: Jakub Jankowski 
Tested-by: Jakub Jankowski 
Signed-off-by: Florian Westphal 
Acked-by: Jozsef Kadlecsik 
Signed-off-by: Pablo Neira Ayuso