Commit graph

830 commits

Author SHA1 Message Date
Eric Dumazet
92548b0ee2 ipv4: fix endianness issue in inet_rtm_getroute_build_skb()
The UDP length field should be in network order.
This removes the following sparse error:

net/ipv4/route.c:3173:27: warning: incorrect type in assignment (different base types)
net/ipv4/route.c:3173:27:    expected restricted __be16 [usertype] len
net/ipv4/route.c:3173:27:    got unsigned long

Fixes: 404eb77ea7 ("ipv4: support sport, dport and ip_proto in RTM_GETROUTE")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Roopa Prabhu <roopa@nvidia.com>
Cc: David Ahern <dsahern@kernel.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-31 12:03:03 +01:00
Eric Dumazet
67d6d681e1 ipv4: make exception cache less predictible
Even after commit 6457378fe7 ("ipv4: use siphash instead of Jenkins in
fnhe_hashfun()"), an attacker can still use brute force to learn
some secrets from a victim linux host.

One way to defeat these attacks is to make the max depth of the hash
table bucket a random value.

Before this patch, each bucket of the hash table used to store exceptions
could contain 6 items under attack.

After the patch, each bucket would contains a random number of items,
between 6 and 10. The attacker can no longer infer secrets.

This is slightly increasing memory size used by the hash table,
by 50% in average, we do not expect this to be a problem.

This patch is more complex than the prior one (IPv6 equivalent),
because IPv4 was reusing the oldest entry.
Since we need to be able to evict more than one entry per
update_or_create_fnhe() call, I had to replace
fnhe_oldest() with fnhe_remove_oldest().

Also note that we will queue extra kfree_rcu() calls under stress,
which hopefully wont be a too big issue.

Fixes: 4895c771c7 ("ipv4: Add FIB nexthop exceptions.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Keyu Man <kman001@ucr.edu>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Reviewed-by: David Ahern <dsahern@kernel.org>
Tested-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-30 12:21:38 +01:00
Jakub Kicinski
97c78d0af5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
drivers/net/wwan/mhi_wwan_mbim.c - drop the extra arg.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-08-26 17:57:57 -07:00
Eric Dumazet
6457378fe7 ipv4: use siphash instead of Jenkins in fnhe_hashfun()
A group of security researchers brought to our attention
the weakness of hash function used in fnhe_hashfun().

Lets use siphash instead of Jenkins Hash, to considerably
reduce security risks.

Also remove the inline keyword, this really is distracting.

Fixes: d546c62154 ("ipv4: harden fnhe_hashfun()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Keyu Man <kman001@ucr.edu>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-26 10:20:34 +01:00
Yajun Deng
1160dfa178 net: Remove redundant if statements
The 'if (dev)' statement already move into dev_{put , hold}, so remove
redundant if statements.

Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-05 13:27:50 +01:00
Yajun Deng
0547ffe624 net: Keep vertical alignment
Those files under /proc/net/stat/ don't have vertical alignment, it looks
very difficult. Modify the seq_printf statement, keep vertical alignment.

v2:
 - Use seq_puts() and seq_printf() correctly.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-08-03 11:51:10 +01:00
Vadim Fedorenko
ac6627a28d net: ipv4: Consolidate ipv4_mtu and ip_dst_mtu_maybe_forward
Consolidate IPv4 MTU code the same way it is done in IPv6 to have code
aligned in both address families

Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-21 08:22:03 -07:00
Jakub Kicinski
b6df00789e Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Trivial conflict in net/netfilter/nf_tables_api.c.

Duplicate fix in tools/testing/selftests/net/devlink_port_split.py
- take the net-next version.

skmsg, and L4 bpf - keep the bpf code but remove the flags
and err params.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-06-29 15:45:27 -07:00
Vadim Fedorenko
fade56410c net: lwtunnel: handle MTU calculation in forwading
Commit 14972cbd34 ("net: lwtunnel: Handle fragmentation") moved
fragmentation logic away from lwtunnel by carry encap headroom and
use it in output MTU calculation. But the forwarding part was not
covered and created difference in MTU for output and forwarding and
further to silent drops on ipv4 forwarding path. Fix it by taking
into account lwtunnel encap headroom.

The same commit also introduced difference in how to treat RTAX_MTU
in IPv4 and IPv6 where latter explicitly removes lwtunnel encap
headroom from route MTU. Make IPv4 version do the same.

Fixes: 14972cbd34 ("net: lwtunnel: Handle fragmentation")
Suggested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-28 12:42:14 -07:00
Jakub Kicinski
adc2e56ebe Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Trivial conflicts in net/can/isotp.c and
tools/testing/selftests/net/mptcp/mptcp_connect.sh

scaled_ppm_to_ppb() was moved from drivers/ptp/ptp_clock.c
to include/linux/ptp_clock_kernel.h in -next so re-apply
the fix there.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-06-18 19:47:02 -07:00
David Ahern
b87b04f501 ipv4: Fix device used for dst_alloc with local routes
Oliver reported a use case where deleting a VRF device can hang
waiting for the refcnt to drop to 0. The root cause is that the dst
is allocated against the VRF device but cached on the loopback
device.

The use case (added to the selftests) has an implicit VRF crossing
due to the ordering of the FIB rules (lookup local is before the
l3mdev rule, but the problem occurs even if the FIB rules are
re-ordered with local after l3mdev because the VRF table does not
have a default route to terminate the lookup). The end result is
is that the FIB lookup returns the loopback device as the nexthop,
but the ingress device is in a VRF. The mismatch causes the dst
alloc against the VRF device but then cached on the loopback.

The fix is to bring the trick used for IPv6 (see ip6_rt_get_dev_rcu):
pick the dst alloc device based the fib lookup result but with checks
that the result has a nexthop device (e.g., not an unreachable or
prohibit entry).

Fixes: f5a0aab84b ("net: ipv4: dst for local input routes should use l3mdev if relevant")
Reported-by: Oliver Herms <oliver.peter.herms@gmail.com>
Signed-off-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-14 12:30:53 -07:00
Ido Schimmel
4253b4986f ipv4: Add custom multipath hash policy
Add a new multipath hash policy where the packet fields used for hash
calculation are determined by user space via the
fib_multipath_hash_fields sysctl that was introduced in the previous
patch.

The current set of available packet fields includes both outer and inner
fields, which requires two invocations of the flow dissector. Avoid
unnecessary dissection of the outer or inner flows by skipping
dissection if none of the outer or inner fields are required.

In accordance with the existing policies, when an skb is not available,
packet fields are extracted from the provided flow key. In which case,
only outer fields are considered.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-05-18 13:27:32 -07:00
Ido Schimmel
2e68ea9268 ipv4: Calculate multipath hash inside switch statement
A subsequent patch will add another multipath hash policy where the
multipath hash is calculated directly by the policy specific code and
not outside of the switch statement.

Prepare for this change by moving the multipath hash calculation inside
the switch statement.

No functional changes intended.

Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-05-18 13:27:32 -07:00
David S. Miller
efd13b71a3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-25 15:31:22 -07:00
Eric Dumazet
aa6dd211e4 inet: use bigger hash table for IP ID generation
In commit 73f156a6e8 ("inetpeer: get rid of ip_id_count")
I used a very small hash table that could be abused
by patient attackers to reveal sensitive information.

Switch to a dynamic sizing, depending on RAM size.

Typical big hosts will now use 128x more storage (2 MB)
to get a similar increase in security and reduction
of hash collisions.

As a bonus, use of alloc_large_system_hash() spreads
allocated memory among all NUMA nodes.

Fixes: 73f156a6e8 ("inetpeer: get rid of ip_id_count")
Reported-by: Amit Klein <aksecurity@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-24 16:45:11 -07:00
Yejune Deng
f105f26e45 net: ipv4: route.c: simplify procfs code
proc_creat_seq() that directly take a struct seq_operations,
and deal with network namespaces in ->open.

Signed-off-by: Yejune Deng <yejune.deng@gmail.com>
Reviewed-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-16 14:43:49 -07:00
Shubhankar Kuranagatti
6ad086009f net: ipv4: route.c: Fix indentation of multi line comment.
All comment lines inside the comment block have been aligned.
Every line of comment starts with a * (uniformity in code).

Signed-off-by: Shubhankar Kuranagatti <shubhankarvk@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-12 17:02:30 -08:00
Shubhankar Kuranagatti
6b9c8f46af net: ipv4: route.c: fix space before tab
The extra space before tab space has been removed.

Signed-off-by: Shubhankar Kuranagatti <shubhankarvk@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-10 15:37:19 -08:00
Daniel Borkmann
c4c877b273 net: Consolidate common blackhole dst ops
Move generic blackhole dst ops to the core and use them from both
ipv4_dst_blackhole_ops and ip6_dst_blackhole_ops where possible. No
functional change otherwise. We need these also in other locations
and having to define them over and over again is not great.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-03-10 12:24:18 -08:00
Amit Cohen
36c5100e85 IPv4: Add "offload failed" indication to routes
After installing a route to the kernel, user space receives an
acknowledgment, which means the route was installed in the kernel, but not
necessarily in hardware.

The asynchronous nature of route installation in hardware can lead to a
routing daemon advertising a route before it was actually installed in
hardware. This can result in packet loss or mis-routed packets until the
route is installed in hardware.

To avoid such cases, previous patch set added the ability to emit
RTM_NEWROUTE notifications whenever RTM_F_OFFLOAD/RTM_F_TRAP flags
are changed, this behavior is controlled by sysctl.

With the above mentioned behavior, it is possible to know from user-space
if the route was offloaded, but if the offload fails there is no indication
to user-space. Following a failure, a routing daemon will wait indefinitely
for a notification that will never come.

This patch adds an "offload_failed" indication to IPv4 routes, so that
users will have better visibility into the offload process.

'struct fib_alias', and 'struct fib_rt_info' are extended with new field
that indicates if route offload failed. Note that the new field is added
using unused bit and therefore there is no need to increase structs size.

Signed-off-by: Amit Cohen <amcohen@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-08 16:47:03 -08:00
Brian Vazquez
9c97921a51 net: fix building errors on powerpc when CONFIG_RETPOLINE is not set
This commit fixes the errores reported when building for powerpc:

 ERROR: modpost: "ip6_dst_check" [vmlinux] is a static EXPORT_SYMBOL
 ERROR: modpost: "ipv4_dst_check" [vmlinux] is a static EXPORT_SYMBOL
 ERROR: modpost: "ipv4_mtu" [vmlinux] is a static EXPORT_SYMBOL
 ERROR: modpost: "ip6_mtu" [vmlinux] is a static EXPORT_SYMBOL

Fixes: f67fbeaebd ("net: use indirect call helpers for dst_mtu")
Fixes: bbd807dfbf ("net: indirect call helpers for ipv4/ipv6 dst_check functions")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Brian Vazquez <brianvv@google.com>
Link: https://lore.kernel.org/r/20210204181839.558951-2-brianvv@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-04 18:06:27 -08:00
Brian Vazquez
bbd807dfbf net: indirect call helpers for ipv4/ipv6 dst_check functions
This patch avoids the indirect call for the common case:
ip6_dst_check and ipv4_dst_check

Signed-off-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-03 14:51:40 -08:00
Brian Vazquez
f67fbeaebd net: use indirect call helpers for dst_mtu
This patch avoids the indirect call for the common case:
ip6_mtu and ipv4_mtu

Signed-off-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-02-03 14:51:39 -08:00
Jakub Kicinski
55fd59b003 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Conflicts:
	drivers/net/ethernet/ibm/ibmvnic.c

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-12-03 15:44:09 -08:00
Guillaume Nault
1ebf179037 ipv4: Fix tos mask in inet_rtm_getroute()
When inet_rtm_getroute() was converted to use the RCU variants of
ip_route_input() and ip_route_output_key(), the TOS parameters
stopped being masked with IPTOS_RT_MASK before doing the route lookup.

As a result, "ip route get" can return a different route than what
would be used when sending real packets.

For example:

    $ ip route add 192.0.2.11/32 dev eth0
    $ ip route add unreachable 192.0.2.11/32 tos 2
    $ ip route get 192.0.2.11 tos 2
    RTNETLINK answers: No route to host

But, packets with TOS 2 (ECT(0) if interpreted as an ECN bit) would
actually be routed using the first route:

    $ ping -c 1 -Q 2 192.0.2.11
    PING 192.0.2.11 (192.0.2.11) 56(84) bytes of data.
    64 bytes from 192.0.2.11: icmp_seq=1 ttl=64 time=0.173 ms

    --- 192.0.2.11 ping statistics ---
    1 packets transmitted, 1 received, 0% packet loss, time 0ms
    rtt min/avg/max/mdev = 0.173/0.173/0.173/0.000 ms

This patch re-applies IPTOS_RT_MASK in inet_rtm_getroute(), to
return results consistent with real route lookups.

Fixes: 3765d35ed8 ("net: ipv4: Convert inet_rtm_getroute to rcu versions of route lookup")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/b2d237d08317ca55926add9654a48409ac1b8f5b.1606412894.git.gnault@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-28 13:14:23 -08:00
Oliver Herms
ae8cb93286 IPv4: RTM_GETROUTE: Add RTA_ENCAP to result
This patch adds an IPv4 routes encapsulation attribute
to the result of netlink RTM_GETROUTE requests
(e.g. ip route get 192.0.2.1).

Signed-off-by: Oliver Herms <oliver.peter.herms@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20201113085517.GA1307262@tws
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-14 16:06:36 -08:00
Vincent Bernat
62679a8d3a net: evaluate net.ipvX.conf.all.disable_policy and disable_xfrm
The disable_policy and disable_xfrm are a per-interface sysctl to
disable IPsec policy or encryption on an interface. However, while a
"all" variant is exposed, it was a noop since it was never evaluated.
We use the usual "or" logic for this kind of sysctls.

Signed-off-by: Vincent Bernat <vincent@bernat.ch>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-11-11 16:41:31 -08:00
Jakub Kicinski
2295cddf99 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Minor conflicts in net/mptcp/protocol.h and
tools/testing/selftests/net/Makefile.

In both cases code was added on both sides in the same place
so just keep both.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-15 12:43:21 -07:00
David Ahern
874fb9e2ca ipv4: Restore flowi4_oif update before call to xfrm_lookup_route
Tobias reported regressions in IPsec tests following the patch
referenced by the Fixes tag below. The root cause is dropping the
reset of the flowi4_oif after the fib_lookup. Apparently it is
needed for xfrm cases, so restore the oif update to ip_route_output_flow
right before the call to xfrm_lookup_route.

Fixes: 2fbc6e89b2 ("ipv4: Update exception handling for multipath routes via same device")
Reported-by: Tobias Brunner <tobias@strongswan.org>
Signed-off-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-10 11:38:59 -07:00
David S. Miller
3ab0a7a0c3 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Two minor conflicts:

1) net/ipv4/route.c, adding a new local variable while
   moving another local variable and removing it's
   initial assignment.

2) drivers/net/dsa/microchip/ksz9477.c, overlapping changes.
   One pretty prints the port mode differently, whilst another
   changes the driver to try and obtain the port mode from
   the port node rather than the switch node.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-22 16:45:34 -07:00
David Ahern
2fbc6e89b2 ipv4: Update exception handling for multipath routes via same device
Kfir reported that pmtu exceptions are not created properly for
deployments where multipath routes use the same device.

After some digging I see 2 compounding problems:
1. ip_route_output_key_hash_rcu is updating the flowi4_oif *after*
   the route lookup. This is the second use case where this has
   been a problem (the first is related to use of vti devices with
   VRF). I can not find any reason for the oif to be changed after the
   lookup; the code goes back to the start of git. It does not seem
   logical so remove it.

2. fib_lookups for exceptions do not call fib_select_path to handle
   multipath route selection based on the hash.

The end result is that the fib_lookup used to add the exception
always creates it based using the first leg of the route.

An example topology showing the problem:

                 |  host1
             +------+
             | eth0 |  .209
             +------+
                 |
             +------+
     switch  | br0  |
             +------+
                 |
       +---------+---------+
       | host2             |  host3
   +------+             +------+
   | eth0 | .250        | eth0 | 192.168.252.252
   +------+             +------+

   +-----+             +-----+
   | vti | .2          | vti | 192.168.247.3
   +-----+             +-----+
       \                  /
 =================================
 tunnels
         192.168.247.1/24

for h in host1 host2 host3; do
        ip netns add ${h}
        ip -netns ${h} link set lo up
        ip netns exec ${h} sysctl -wq net.ipv4.ip_forward=1
done

ip netns add switch
ip -netns switch li set lo up
ip -netns switch link add br0 type bridge stp 0
ip -netns switch link set br0 up

for n in 1 2 3; do
        ip -netns switch link add eth-sw type veth peer name eth-h${n}
        ip -netns switch li set eth-h${n} master br0 up
        ip -netns switch li set eth-sw netns host${n} name eth0
done

ip -netns host1 addr add 192.168.252.209/24 dev eth0
ip -netns host1 link set dev eth0 up
ip -netns host1 route add 192.168.247.0/24 \
        nexthop via 192.168.252.250 dev eth0 nexthop via 192.168.252.252 dev eth0

ip -netns host2 addr add 192.168.252.250/24 dev eth0
ip -netns host2 link set dev eth0 up

ip -netns host2 addr add 192.168.252.252/24 dev eth0
ip -netns host3 link set dev eth0 up

ip netns add tunnel
ip -netns tunnel li set lo up
ip -netns tunnel li add br0 type bridge
ip -netns tunnel li set br0 up
for n in $(seq 11 20); do
        ip -netns tunnel addr add dev br0 192.168.247.${n}/24
done

for n in 2 3
do
        ip -netns tunnel link add vti${n} type veth peer name eth${n}
        ip -netns tunnel link set eth${n} mtu 1360 master br0 up
        ip -netns tunnel link set vti${n} netns host${n} mtu 1360 up
        ip -netns host${n} addr add dev vti${n} 192.168.247.${n}/24
done
ip -netns tunnel ro add default nexthop via 192.168.247.2 nexthop via 192.168.247.3

ip netns exec host1 ping -M do -s 1400 -c3 -I 192.168.252.209 192.168.247.11
ip netns exec host1 ping -M do -s 1400 -c3 -I 192.168.252.209 192.168.247.15
ip -netns host1 ro ls cache

Before this patch the cache always shows exceptions against the first
leg in the multipath route; 192.168.252.250 per this example. Since the
hash has an initial random seed, you may need to vary the final octet
more than what is listed. In my tests, using addresses between 11 and 19
usually found 1 that used both legs.

With this patch, the cache will have exceptions for both legs.

Fixes: 4895c771c7 ("ipv4: Add FIB nexthop exceptions")
Reported-by: Kfir Itzhak <mastertheknife@gmail.com>
Signed-off-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-15 15:44:09 -07:00
David Ahern
1869e226a7 ipv4: Initialize flowi4_multipath_hash in data path
flowi4_multipath_hash was added by the commit referenced below for
tunnels. Unfortunately, the patch did not initialize the new field
for several fast path lookups that do not initialize the entire flow
struct to 0. Fix those locations. Currently, flowi4_multipath_hash
is random garbage and affects the hash value computed by
fib_multipath_hash for multipath selection.

Fixes: 24ba14406c ("route: Add multipath_hash in flowi_common to make user-define hash")
Signed-off-by: David Ahern <dsahern@gmail.com>
Cc: wenxu <wenxu@ucloud.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-14 14:54:56 -07:00
Miaohe Lin
5af68891dc net: clean up codestyle
This is a pure codestyle cleanup patch. No functional change intended.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-31 12:33:34 -07:00
Miaohe Lin
343d8c6014 net: clean up codestyle for net/ipv4
This is a pure codestyle cleanup patch. Also add a blank line after
declarations as warned by checkpatch.pl.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-25 06:28:02 -07:00
Miaohe Lin
8b4510d76c net: gain ipv4 mtu when mtu is not locked
When mtu is locked, we should not obtain ipv4 mtu as we return immediately
in this case and leave acquired ipv4 mtu unused.

Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-25 06:04:39 -07:00
Stefano Brivio
df23bb18b4 ipv4: route: Ignore output interface in FIB lookup for PMTU route
Currently, processes sending traffic to a local bridge with an
encapsulation device as a port don't get ICMP errors if they exceed
the PMTU of the encapsulated link.

David Ahern suggested this as a hack, but it actually looks like
the correct solution: when we update the PMTU for a given destination
by means of updating or creating a route exception, the encapsulation
might trigger this because of PMTU discovery happening either on the
encapsulation device itself, or its lower layer. This happens on
bridged encapsulations only.

The output interface shouldn't matter, because we already have a
valid destination. Drop the output interface restriction from the
associated route lookup.

For UDP tunnels, we will now have a route exception created for the
encapsulation itself, with a MTU value reflecting its headroom, which
allows a bridge forwarding IP packets originated locally to deliver
errors back to the sending socket.

The behaviour is now consistent with IPv6 and verified with selftests
pmtu_ipv{4,6}_br_{geneve,vxlan}{4,6}_exception introduced later in
this series.

v2:
- reset output interface only for bridge ports (David Ahern)
- add and use netif_is_any_bridge_port() helper (David Ahern)

Suggested-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-04 13:01:45 -07:00
Miaohe Lin
2ce578ca94 net: ipv4: Fix wrong type conversion from hint to rt in ip_route_use_hint()
We can't cast sk_buff to rtable by (struct rtable *)hint. Use skb_rtable().

Fixes: 02b2494161 ("ipv4: use dst hint for ipv4 list receive")
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-27 18:02:32 -07:00
David S. Miller
13209a8f73 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
The MSCC bug fix in 'net' had to be slightly adjusted because the
register accesses are done slightly differently in net-next.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-24 13:47:27 -07:00
Yuqi Jin
a6211caa63 net: revert "net: get rid of an signed integer overflow in ip_idents_reserve()"
Commit adb03115f4 ("net: get rid of an signed integer overflow in ip_idents_reserve()")
used atomic_cmpxchg to replace "atomic_add_return" inside the function
"ip_idents_reserve". The reason was to avoid UBSAN warning.
However, this change has caused performance degrade and in GCC-8,
fno-strict-overflow is now mapped to -fwrapv -fwrapv-pointer
and signed integer overflow is now undefined by default at all
optimization levels[1]. Moreover, it was a bug in UBSAN vs -fwrapv
/-fno-strict-overflow, so Let's revert it safely.

[1] https://gcc.gnu.org/gcc-8/changes.html

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Eric Dumazet <edumazet@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Jiri Pirko <jiri@resnulli.us>
Cc: Arvind Sankar <nivedita@alum.mit.edu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jiong Wang <jiongwang@huawei.com>
Signed-off-by: Yuqi Jin <jinyuqi@huawei.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-17 12:33:51 -07:00
David S. Miller
da07f52d3c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Move the bpf verifier trace check into the new switch statement in
HEAD.

Resolve the overlapping changes in hinic, where bug fixes overlap
the addition of VF support.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-15 13:48:59 -07:00
Paolo Abeni
57644431a6 net: ipv4: really enforce backoff for redirects
In commit b406472b5a ("net: ipv4: avoid mixed n_redirects and
rate_tokens usage") I missed the fact that a 0 'rate_tokens' will
bypass the backoff algorithm.

Since rate_tokens is cleared after a redirect silence, and never
incremented on redirects, if the host keeps receiving packets
requiring redirect it will reply ignoring the backoff.

Additionally, the 'rate_last' field will be updated with the
cadence of the ingress packet requiring redirect. If that rate is
high enough, that will prevent the host from generating any
other kind of ICMP messages

The check for a zero 'rate_tokens' value was likely a shortcut
to avoid the more complex backoff algorithm after a redirect
silence period. Address the issue checking for 'n_redirects'
instead, which is incremented on successful redirect, and
does not interfere with other ICMP replies.

Fixes: b406472b5a ("net: ipv4: avoid mixed n_redirects and rate_tokens usage")
Reported-and-tested-by: Colin Walters <walters@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-05-08 22:52:57 -07:00
Christoph Hellwig
32927393dc sysctl: pass kernel pointers to ->proc_handler
Instead of having all the sysctl handlers deal with user pointers, which
is rather hairy in terms of the BPF interaction, copy the input to and
from  userspace in common code.  This also means that the strings are
always NUL-terminated by the common code, making the API a little bit
safer.

As most handler just pass through the data to one of the common handlers
a lot of the changes are mechnical.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-04-27 02:07:40 -04:00
David Laight
af13b3c338 Remove DST_HOST
Previous changes to the IP routing code have removed all the
tests for the DS_HOST route flag.
Remove the flags and all the code that sets it.

Signed-off-by: David Laight <david.laight@aculab.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-23 21:57:44 -07:00
Martin Varghese
571912c69f net: UDP tunnel encapsulation module for tunnelling different protocols like MPLS, IP, NSH etc.
The Bareudp tunnel module provides a generic L3 encapsulation
tunnelling module for tunnelling different protocols like MPLS,
IP,NSH etc inside a UDP tunnel.

Signed-off-by: Martin Varghese <martin.varghese@nokia.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-24 13:31:42 -08:00
Alexey Dobriyan
97a32539b9 proc: convert everything to "struct proc_ops"
The most notable change is DEFINE_SHOW_ATTRIBUTE macro split in
seq_file.h.

Conversion rule is:

	llseek		=> proc_lseek
	unlocked_ioctl	=> proc_ioctl

	xxx		=> proc_xxx

	delete ".owner = THIS_MODULE" line

[akpm@linux-foundation.org: fix drivers/isdn/capi/kcapi_proc.c]
[sfr@canb.auug.org.au: fix kernel/sched/psi.c]
  Link: http://lkml.kernel.org/r/20200122180545.36222f50@canb.auug.org.au
Link: http://lkml.kernel.org/r/20191225172546.GB13378@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-02-04 03:05:26 +00:00
David S. Miller
4d8773b68e Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Minor conflict in mlx5 because changes happened to code that has
moved meanwhile.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-26 10:40:21 +01:00
Vasily Averin
a3ea86739f rt_cpu_seq_next should increase position index
if seq_file .next fuction does not change position index,
read after some lseek can generate unexpected output.

https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-24 11:42:18 +01:00
Ido Schimmel
90b93f1b31 ipv4: Add "offload" and "trap" indications to routes
When performing L3 offload, routes and nexthops are usually programmed
into two different tables in the underlying device. Therefore, the fact
that a nexthop resides in hardware does not necessarily mean that all
the associated routes also reside in hardware and vice-versa.

While the kernel can signal to user space the presence of a nexthop in
hardware (via 'RTNH_F_OFFLOAD'), it does not have a corresponding flag
for routes. In addition, the fact that a route resides in hardware does
not necessarily mean that the traffic is offloaded. For example,
unreachable routes (i.e., 'RTN_UNREACHABLE') are programmed to trap
packets to the CPU so that the kernel will be able to generate the
appropriate ICMP error packet.

This patch adds an "offload" and "trap" indications to IPv4 routes, so
that users will have better visibility into the offload process.

'struct fib_alias' is extended with two new fields that indicate if the
route resides in hardware or not and if it is offloading traffic from
the kernel or trapping packets to it. Note that the new fields are added
in the 6 bytes hole and therefore the struct still fits in a single
cache line [1].

Capable drivers are expected to invoke fib_alias_hw_flags_set() with the
route's key in order to set the flags.

The indications are dumped to user space via a new flags (i.e.,
'RTM_F_OFFLOAD' and 'RTM_F_TRAP') in the 'rtm_flags' field in the
ancillary header.

v2:
* Make use of 'struct fib_rt_info' in fib_alias_hw_flags_set()

[1]
struct fib_alias {
        struct hlist_node  fa_list;                      /*     0    16 */
        struct fib_info *          fa_info;              /*    16     8 */
        u8                         fa_tos;               /*    24     1 */
        u8                         fa_type;              /*    25     1 */
        u8                         fa_state;             /*    26     1 */
        u8                         fa_slen;              /*    27     1 */
        u32                        tb_id;                /*    28     4 */
        s16                        fa_default;           /*    32     2 */
        u8                         offload:1;            /*    34: 0  1 */
        u8                         trap:1;               /*    34: 1  1 */
        u8                         unused:6;             /*    34: 2  1 */

        /* XXX 5 bytes hole, try to pack */

        struct callback_head rcu __attribute__((__aligned__(8))); /*    40    16 */

        /* size: 56, cachelines: 1, members: 12 */
        /* sum members: 50, holes: 1, sum holes: 5 */
        /* sum bitfield members: 8 bits (1 bytes) */
        /* forced alignments: 1, forced holes: 1, sum forced holes: 5 */
        /* last cacheline: 56 bytes */
} __attribute__((__aligned__(8)));

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-14 18:53:35 -08:00
Ido Schimmel
1e301fd04e ipv4: Encapsulate function arguments in a struct
fib_dump_info() is used to prepare RTM_{NEW,DEL}ROUTE netlink messages
using the passed arguments. Currently, the function takes 11 arguments,
6 of which are attributes of the route being dumped (e.g., prefix, TOS).

The next patch will need the function to also dump to user space an
indication if the route is present in hardware or not. Instead of
passing yet another argument, change the function to take a struct
containing the different route attributes.

v2:
* Name last argument of fib_dump_info()
* Move 'struct fib_rt_info' to include/net/ip_fib.h so that it could
  later be passed to fib_alias_hw_flags_set()

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-14 18:53:35 -08:00
Hangbin Liu
bd085ef678 net: add bool confirm_neigh parameter for dst_ops.update_pmtu
The MTU update code is supposed to be invoked in response to real
networking events that update the PMTU. In IPv6 PMTU update function
__ip6_rt_update_pmtu() we called dst_confirm_neigh() to update neighbor
confirmed time.

But for tunnel code, it will call pmtu before xmit, like:
  - tnl_update_pmtu()
    - skb_dst_update_pmtu()
      - ip6_rt_update_pmtu()
        - __ip6_rt_update_pmtu()
          - dst_confirm_neigh()

If the tunnel remote dst mac address changed and we still do the neigh
confirm, we will not be able to update neigh cache and ping6 remote
will failed.

So for this ip_tunnel_xmit() case, _EVEN_ if the MTU is changed, we
should not be invoking dst_confirm_neigh() as we have no evidence
of successful two-way communication at this point.

On the other hand it is also important to keep the neigh reachability fresh
for TCP flows, so we cannot remove this dst_confirm_neigh() call.

To fix the issue, we have to add a new bool parameter for dst_ops.update_pmtu
to choose whether we should do neigh update or not. I will add the parameter
in this patch and set all the callers to true to comply with the previous
way, and fix the tunnel code one by one on later patches.

v5: No change.
v4: No change.
v3: Do not remove dst_confirm_neigh, but add a new bool parameter in
    dst_ops.update_pmtu to control whether we should do neighbor confirm.
    Also split the big patch to small ones for each area.
v2: Remove dst_confirm_neigh in __ip6_rt_update_pmtu.

Suggested-by: David Miller <davem@davemloft.net>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-24 22:28:54 -08:00