Pablo Neira Ayuso says:
====================
Netfilter fixes for net
The following patchset contains Netfilter fixes for your net tree,
they are:
1) Fix incorrect timestamp in nfnetlink_queue introduced when addressing
y2038 safe timestamp, from Florian Westphal.
2) Get rid of leftover conntrack definition from the previous merge
window, oneliner from Florian.
3) Make nf_queue handler pernet to resolve race on dereferencing the
hook state structure with netns removal, from Eric Biederman.
4) Ensure clean exit on unregistered helper ports, from Taehee Yoo.
5) Restore FLOWI_FLAG_KNOWN_NH in nf_dup_ipv6. This got lost while
generalizing xt_TEE to add packet duplication support in nf_tables,
from Paolo Abeni.
6) Insufficient netlink NFTA_SET_TABLE attribute check in
nf_tables_getset(), from Phil Turnbull.
7) Reject helper registration on duplicated ports via modparams.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Florian Weber reported:
> Under full load (unshare() in loop -> OOM conditions) we can
> get kernel panic:
>
> BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
> IP: [<ffffffff81476c85>] nfqnl_nf_hook_drop+0x35/0x70
> [..]
> task: ffff88012dfa3840 ti: ffff88012dffc000 task.ti: ffff88012dffc000
> RIP: 0010:[<ffffffff81476c85>] [<ffffffff81476c85>] nfqnl_nf_hook_drop+0x35/0x70
> RSP: 0000:ffff88012dfffd80 EFLAGS: 00010206
> RAX: 0000000000000008 RBX: ffffffff81add0c0 RCX: ffff88013fd80000
> [..]
> Call Trace:
> [<ffffffff81474d98>] nf_queue_nf_hook_drop+0x18/0x20
> [<ffffffff814738eb>] nf_unregister_net_hook+0xdb/0x150
> [<ffffffff8147398f>] netfilter_net_exit+0x2f/0x60
> [<ffffffff8141b088>] ops_exit_list.isra.4+0x38/0x60
> [<ffffffff8141b652>] setup_net+0xc2/0x120
> [<ffffffff8141bd09>] copy_net_ns+0x79/0x120
> [<ffffffff8106965b>] create_new_namespaces+0x11b/0x1e0
> [<ffffffff810698a7>] unshare_nsproxy_namespaces+0x57/0xa0
> [<ffffffff8104baa2>] SyS_unshare+0x1b2/0x340
> [<ffffffff81608276>] entry_SYSCALL_64_fastpath+0x1e/0xa8
> Code: 65 00 48 89 e5 41 56 41 55 41 54 53 83 e8 01 48 8b 97 70 12 00 00 48 98 49 89 f4 4c 8b 74 c2 18 4d 8d 6e 08 49 81 c6 88 00 00 00 <49> 8b 5d 00 48 85 db 74 1a 48 89 df 4c 89 e2 48 c7 c6 90 68 47
>
The simple fix for this requires a new pernet variable for struct
nf_queue that indicates when it is safe to use the dynamically
allocated nf_queue state.
As we need a variable anyway make nf_register_queue_handler and
nf_unregister_queue_handler pernet. This allows the existing logic of
when it is safe to use the state from the nfnetlink_queue module to be
reused with no changes except for making it per net.
The syncrhonize_rcu from nf_unregister_queue_handler is moved to a new
function nfnl_queue_net_exit_batch so that the worst case of having a
syncrhonize_rcu in the pernet exit path is not experienced in batch
mode.
Reported-by: Florian Westphal <fw@strlen.de>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
In netdevice.h we removed the structure in net-next that is being
changes in 'net'. In macsec.c and rtnetlink.c we have overlaps
between fixes in 'net' and the u64 attribute changes in 'net-next'.
The mlx5 conflicts have to do with vxlan support dependencies.
Signed-off-by: David S. Miller <davem@davemloft.net>
An earlier patch changed lookup side to also net_eq() namespaces after
obtaining a reference on the conntrack, so a single kmemcache can be used.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
We already include netns address in the hash, so we only need to use
net_eq in find_appropriate_src and can then put all entries into
same table.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
We already include netns address in the hash and compare the netns pointers
during lookup, so even if namespaces have overlapping addresses entries
will be spread across the expectation table.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
We already include netns address in the hash and compare the netns pointers
during lookup, so even if namespaces have overlapping addresses entries
will be spread across the table.
Assuming 64k bucket size, this change saves 0.5 mbyte per namespace on a
64bit system.
NAT bysrc and expectation hash is still per namespace, those will
changed too soon.
Future patch will also make conntrack object slab cache global again.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Steffen Klassert says:
====================
pull request (net): ipsec 2016-05-04
1) The flowcache can hit an OOM condition if too
many entries are in the gc_list. Fix this by
counting the entries in the gc_list and refuse
new allocations if the value is too high.
2) The inner headers are invalid after a xfrm transformation,
so reset the skb encapsulation field to ensure nobody tries
access the inner headers. Otherwise tunnel devices stacked
on top of xfrm may build the outer headers based on wrong
informations.
3) Add pmtu handling to vti, we need it to report
pmtu informations for local generated packets.
Please pull or let me know if there are problems.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
We only allow rehash in init namespace, so we only use
init_ns.generation. And even if we would allow it, it makes no sense
as the conntrack locks are global; any ongoing rehash prevents insert/
delete.
So make this private to nf_conntrack_core instead.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Multipath route lookups should consider knowledge about next hops and not
select a hop that is known to be failed.
Example:
[h2] [h3] 15.0.0.5
| |
3| 3|
[SP1] [SP2]--+
1 2 1 2
| | /-------------+ |
| \ / |
| X |
| / \ |
| / \---------------\ |
1 2 1 2
12.0.0.2 [TOR1] 3-----------------3 [TOR2] 12.0.0.3
4 4
\ /
\ /
\ /
-------| |-----/
1 2
[TOR3]
3|
|
[h1] 12.0.0.1
host h1 with IP 12.0.0.1 has 2 paths to host h3 at 15.0.0.5:
root@h1:~# ip ro ls
...
12.0.0.0/24 dev swp1 proto kernel scope link src 12.0.0.1
15.0.0.0/16
nexthop via 12.0.0.2 dev swp1 weight 1
nexthop via 12.0.0.3 dev swp1 weight 1
...
If the link between tor3 and tor1 is down and the link between tor1
and tor2 then tor1 is effectively cut-off from h1. Yet the route lookups
in h1 are alternating between the 2 routes: ping 15.0.0.5 gets one and
ssh 15.0.0.5 gets the other. Connections that attempt to use the
12.0.0.2 nexthop fail since that neighbor is not reachable:
root@h1:~# ip neigh show
...
12.0.0.3 dev swp1 lladdr 00:02:00:00:00:1b REACHABLE
12.0.0.2 dev swp1 FAILED
...
The failed path can be avoided by considering known neighbor information
when selecting next hops. If the neighbor lookup fails we have no
knowledge about the nexthop, so give it a shot. If there is an entry
then only select the nexthop if the state is sane. This is similar to
what fib_detect_death does.
To maintain backward compatibility use of the neighbor information is
based on a new sysctl, fib_multipath_use_neigh.
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Reviewed-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
We can hit an OOM condition if we are under presure because
we can not free the entries in gc_list fast enough. So add
a counter for the not yet freed entries in the gc_list and
refuse new allocations if the value is too high.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
One of our customers observed issues with FIB6 garbage collectors
running in different network namespaces blocking each other, resulting
in soft lockups (fib6_run_gc() initiated from timer runs always in
forced mode).
Now that FIB6 walkers are separated per namespace, there is no more need
for instances of fib6_run_gc() in different namespaces blocking each
other. There is still a call to icmp6_dst_gc() which operates on shared
data but this function is protected by its own shared lock.
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The IPv6 FIB data structures are separated per network namespace but
there is still only one global walkers list and one global walker list
lock. This means changes in one namespace unnecessarily interfere with
walkers in other namespaces.
Replace the global list with per-netns lists (and give each its own
lock).
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This was initially introduced in df2cf4a78e ("IGMP: Inhibit
reports for local multicast groups") by defining the sysctl in the
ipv4_net_table array, however it was never implemented to be
namespace aware. Fix this by changing the code accordingly.
Signed-off-by: David S. Miller <davem@davemloft.net>
This is the final part required to namespaceify the tcp
keep alive mechanism.
Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is required to have full tcp keepalive mechanism namespace
support.
Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Different net namespaces might have different requirements as to
the keepalive time of tcp sockets. This might be required in cases
where different firewall rules are in place which require tcp
timeout sockets to be increased/decreased independently of the host.
Signed-off-by: Nikolay Borisov <kernel@kyup.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Allow accepted sockets to derive their sk_bound_dev_if setting from the
l3mdev domain in which the packets originated. A sysctl setting is added
to control the behavior which is similar to sk_mark and
sysctl_tcp_fwmark_accept.
This effectively allow a process to have a "VRF-global" listen socket,
with child sockets bound to the VRF device in which the packet originated.
A similar behavior can be achieved using sk_mark, but a solution using marks
is incomplete as it does not handle duplicate addresses in different L3
domains/VRFs. Allowing sockets to inherit the sk_bound_dev_if from l3mdev
domain provides a complete solution.
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
As we all know, the value of pf_retrans >= max_retrans_path can
disable pf state. The variables of pf_retrans and max_retrans_path
can be changed by the userspace application.
Sometimes the user expects to disable pf state while the 2
variables are changed to enable pf state. So it is necessary to
introduce a new variable to disable pf state.
According to the suggestions from Vlad Yasevich, extra1 and extra2
are removed. The initialization of pf_enable is added.
Acked-by: Vlad Yasevich <vyasevich@gmail.com>
Signed-off-by: Zhu Yanjun <zyjzyj2000@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pablo Neira Ayuso says:
====================
Netfilter updates for net-next
The following patchset contains Netfilter updates for net-next, they are:
1) A couple of cleanups for the netfilter core hook from Eric Biederman.
2) Net namespace hook registration, also from Eric. This adds a dependency with
the rtnl_lock. This should be fine by now but we have to keep an eye on this
because if we ever get the per-subsys nfnl_lock before rtnl we have may
problems in the future. But we have room to remove this in the future by
propagating the complexity to the clients, by registering hooks for the init
netns functions.
3) Update nf_tables to use the new net namespace hook infrastructure, also from
Eric.
4) Three patches to refine and to address problems from the new net namespace
hook infrastructure.
5) Switch to alternate jumpstack in xtables iff the packet is reentering. This
only applies to a very special case, the TEE target, but Eric Dumazet
reports that this is slowing down things for everyone else. So let's only
switch to the alternate jumpstack if the tee target is in used through a
static key. This batch also comes with offline precalculation of the
jumpstack based on the callchain depth. From Florian Westphal.
6) Minimal SCTP multihoming support for our conntrack helper, from Michal
Kubecek.
7) Reduce nf_bridge_info per skbuff scratchpad area to 32 bytes, from Florian
Westphal.
8) Fix several checkpatch errors in bridge netfilter, from Bernhard Thaler.
9) Get rid of useless debug message in ip6t_REJECT, from Subash Abhinov.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
arch/s390/net/bpf_jit_comp.c
drivers/net/ethernet/ti/netcp_ethss.c
net/bridge/br_multicast.c
net/ipv4/ip_fragment.c
All four conflicts were cases of simple overlapping
changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
Quoting Daniel Borkmann:
"When adding connection tracking template rules to a netns, f.e. to
configure netfilter zones, the kernel will endlessly busy-loop as soon
as we try to delete the given netns in case there's at least one
template present, which is problematic i.e. if there is such bravery that
the priviledged user inside the netns is assumed untrusted.
Minimal example:
ip netns add foo
ip netns exec foo iptables -t raw -A PREROUTING -d 1.2.3.4 -j CT --zone 1
ip netns del foo
What happens is that when nf_ct_iterate_cleanup() is being called from
nf_conntrack_cleanup_net_list() for a provided netns, we always end up
with a net->ct.count > 0 and thus jump back to i_see_dead_people. We
don't get a soft-lockup as we still have a schedule() point, but the
serving CPU spins on 100% from that point onwards.
Since templates are normally allocated with nf_conntrack_alloc(), we
also bump net->ct.count. The issue why they are not yet nf_ct_put() is
because the per netns .exit() handler from x_tables (which would eventually
invoke xt_CT's xt_ct_tg_destroy() that drops reference on info->ct) is
called in the dependency chain at a *later* point in time than the per
netns .exit() handler for the connection tracker.
This is clearly a chicken'n'egg problem: after the connection tracker
.exit() handler, we've teared down all the connection tracking
infrastructure already, so rightfully, xt_ct_tg_destroy() cannot be
invoked at a later point in time during the netns cleanup, as that would
lead to a use-after-free. At the same time, we cannot make x_tables depend
on the connection tracker module, so that the xt_ct_tg_destroy() would
be invoked earlier in the cleanup chain."
Daniel confirms this has to do with the order in which modules are loaded or
having compiled nf_conntrack as modules while x_tables built-in. So we have no
guarantees regarding the order in which netns callbacks are executed.
Fix this by allocating the templates through kmalloc() from the respective
SYNPROXY and CT targets, so they don't depend on the conntrack kmem cache.
Then, release then via nf_ct_tmpl_free() from destroy_conntrack(). This branch
is marked as unlikely since conntrack templates are rarely allocated and only
from the configuration plane path.
Note that templates are not kept in any list to avoid further dependencies with
nf_conntrack anymore, thus, the tmpl larval list is removed.
Reported-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Tested-by: Daniel Borkmann <daniel@iogearbox.net>
- Add a new set of functions for registering and unregistering per
network namespace hooks.
- Modify the old global namespace hook functions to use the per
network namespace hooks in their implementation, so their remains a
single list that needs to be walked for any hook (this is important
for keeping the hook priority working and for keeping the code
walking the hooks simple).
- Only allow registering the per netdevice hooks in the network
namespace where the network device lives.
- Dynamically allocate the structures in the per network namespace
hook list in nf_register_net_hook, and unregister them in
nf_unregister_net_hook.
Dynamic allocate is required somewhere as the number of network
namespaces are not fixed so we might as well allocate them in the
registration function.
The chain of registered hooks on any list is expected to be small so
the cost of walking that list to find the entry we are unregistering
should also be small.
Performing the management of the dynamically allocated list entries
in the registration and unregistration functions keeps the complexity
from spreading.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Add support to allow non-local binds similar to how this was done for IPv4.
Non-local binds are very useful in emulating the Internet in a box, etc.
This add the ip_nonlocal_bind sysctl under ipv6.
Testing:
Set up nonlocal binding and receive routing on a host, e.g.:
ip -6 rule add from ::/0 iif eth0 lookup 200
ip -6 route add local 2001:0:0:1::/64 dev lo proto kernel scope host table 200
sysctl -w net.ipv6.ip_nonlocal_bind=1
Set up routing to 2001:0:0:1::/64 on peer to go to first host
ping6 -I 2001:0:0:1::1 peer-address -- to verify
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/net/ethernet/mellanox/mlx4/main.c
net/packet/af_packet.c
Both conflicts were cases of simple overlapping changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
This pulls the full hook netfilter definitions from all those that include
net_namespace.h.
Instead let's just include the bare minimum required in the new
linux/netfilter_defs.h file, and use it from the netfilter netns header files.
I also needed to include in.h and in6.h from linux/netfilter.h otherwise we hit
this compilation error:
In file included from include/linux/netfilter_defs.h:4:0,
from include/net/netns/netfilter.h:4,
from include/net/net_namespace.h:22,
from include/linux/netdevice.h:43,
from net/netfilter/nfnetlink_queue_core.c:23:
include/uapi/linux/netfilter.h:76:17: error: field ‘in’ has incomplete type struct in_addr in;
And also explicit include linux/netfilter.h in several spots.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
We don't need to pull the full definitions in that file, a simple forward
declaration is enough.
Moreover, include linux/procfs.h from nf_synproxy_core, otherwise this hits a
compilation error due to missing declarations, ie.
net/netfilter/nf_synproxy_core.c: In function ‘synproxy_proc_init’:
net/netfilter/nf_synproxy_core.c:326:2: error: implicit declaration of function ‘proc_create’ [-Werror=implicit-function-declaration]
if (!proc_create("synproxy", S_IRUGO, net->proc_net_stat,
^
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
->auto_asconf_splist is per namespace and mangled by functions like
sctp_setsockopt_auto_asconf() which doesn't guarantee any serialization.
Also, the call to inet_sk_copy_descendant() was backuping
->auto_asconf_list through the copy but was not honoring
->do_auto_asconf, which could lead to list corruption if it was
different between both sockets.
This commit thus fixes the list handling by using ->addr_wq_lock
spinlock to protect the list. A special handling is done upon socket
creation and destruction for that. Error handlig on sctp_init_sock()
will never return an error after having initialized asconf, so
sctp_destroy_sock() can be called without addrq_wq_lock. The lock now
will be take on sctp_close_sock(), before locking the socket, so we
don't do it in inverse order compared to sctp_addr_wq_timeout_handler().
Instead of taking the lock on sctp_sock_migrate() for copying and
restoring the list values, it's preferred to avoid rewritting it by
implementing sctp_copy_descendant().
Issue was found with a test application that kept flipping sysctl
default_auto_asconf on and off, but one could trigger it by issuing
simultaneous setsockopt() calls on multiple sockets or by
creating/destroying sockets fast enough. This is only triggerable
locally.
Fixes: 9f7d653b67 ("sctp: Add Auto-ASCONF support (core).")
Reported-by: Ji Jianwen <jiji@redhat.com>
Suggested-by: Neil Horman <nhorman@tuxdriver.com>
Suggested-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pablo Neira Ayuso says:
====================
Netfilter updates for net-next
The following patchset contains Netfilter updates for net-next, they are:
1) default CONFIG_NETFILTER_INGRESS to y for easier compile-testing of all
options.
2) Allow to bind a table to net_device. This introduces the internal
NFT_AF_NEEDS_DEV flag to perform a mandatory check for this binding.
This is required by the next patch.
3) Add the 'netdev' table family, this new table allows you to create ingress
filter basechains. This provides access to the existing nf_tables features
from ingress.
4) Kill unused argument from compat_find_calc_{match,target} in ip_tables
and ip6_tables, from Florian Westphal.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
After commit 07f4c90062 ("tcp/dccp: try to not exhaust
ip_local_port_range in connect()") it is advised to have an even number
of ports described in /proc/sys/net/ipv4/ip_local_port_range
This means start/end values should have a different parity.
Let's warn sysadmins of this, so that they can update their settings
if they want to.
Suggested-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This allows us to create netdev tables that contain ingress chains. Use
skb_header_pointer() as we may see shared sk_buffs at this stage.
This change provides access to the existing nf_tables features from the ingress
hook.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This work as a follow-up of commit f7b3bec6f5 ("net: allow setting ecn
via routing table") and adds RFC3168 section 6.1.1.1. fallback for outgoing
ECN connections. In other words, this work adds a retry with a non-ECN
setup SYN packet, as suggested from the RFC on the first timeout:
[...] A host that receives no reply to an ECN-setup SYN within the
normal SYN retransmission timeout interval MAY resend the SYN and
any subsequent SYN retransmissions with CWR and ECE cleared. [...]
Schematic client-side view when assuming the server is in tcp_ecn=2 mode,
that is, Linux default since 2009 via commit 255cac91c3 ("tcp: extend
ECN sysctl to allow server-side only ECN"):
1) Normal ECN-capable path:
SYN ECE CWR ----->
<----- SYN ACK ECE
ACK ----->
2) Path with broken middlebox, when client has fallback:
SYN ECE CWR ----X crappy middlebox drops packet
(timeout, rtx)
SYN ----->
<----- SYN ACK
ACK ----->
In case we would not have the fallback implemented, the middlebox drop
point would basically end up as:
SYN ECE CWR ----X crappy middlebox drops packet
(timeout, rtx)
SYN ECE CWR ----X crappy middlebox drops packet
(timeout, rtx)
SYN ECE CWR ----X crappy middlebox drops packet
(timeout, rtx)
In any case, it's rather a smaller percentage of sites where there would
occur such additional setup latency: it was found in end of 2014 that ~56%
of IPv4 and 65% of IPv6 servers of Alexa 1 million list would negotiate
ECN (aka tcp_ecn=2 default), 0.42% of these webservers will fail to connect
when trying to negotiate with ECN (tcp_ecn=1) due to timeouts, which the
fallback would mitigate with a slight latency trade-off. Recent related
paper on this topic:
Brian Trammell, Mirja Kühlewind, Damiano Boppart, Iain Learmonth,
Gorry Fairhurst, and Richard Scheffenegger:
"Enabling Internet-Wide Deployment of Explicit Congestion Notification."
Proc. PAM 2015, New York.
http://ecn.ethz.ch/ecn-pam15.pdf
Thus, when net.ipv4.tcp_ecn=1 is being set, the patch will perform RFC3168,
section 6.1.1.1. fallback on timeout. For users explicitly not wanting this
which can be in DC use case, we add a net.ipv4.tcp_ecn_fallback knob that
allows for disabling the fallback.
tp->ecn_flags are not being cleared in tcp_ecn_clear_syn() on output, but
rather we let tcp_ecn_rcv_synack() take that over on input path in case a
SYN ACK ECE was delayed. Thus a spurious SYN retransmission will not prevent
ECN being negotiated eventually in that case.
Reference: https://www.ietf.org/proceedings/92/slides/slides-92-iccrg-1.pdf
Reference: https://www.ietf.org/proceedings/89/slides/slides-89-tsvarea-1.pdf
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Mirja Kühlewind <mirja.kuehlewind@tik.ee.ethz.ch>
Signed-off-by: Brian Trammell <trammell@tik.ee.ethz.ch>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Dave That <dave.taht@gmail.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch divides the IPv6 flow label space into two ranges:
0-7ffff is reserved for flow label manager, 80000-fffff will be
used for creating auto flow labels (per RFC6438). This only affects how
labels are set on transmit, it does not affect receive. This range split
can be disbaled by systcl.
Background:
IPv6 flow labels have been an unmitigated disappointment thus far
in the lifetime of IPv6. Support in HW devices to use them for ECMP
is lacking, and OSes don't turn them on by default. If we had these
we could get much better hashing in IPv6 networks without resorting
to DPI, possibly eliminating some of the motivations to to define new
encaps in UDP just for getting ECMP.
Unfortunately, the initial specfications of IPv6 did not clarify
how they are to be used. There has always been a vague concept that
these can be used for ECMP, flow hashing, etc. and we do now have a
good standard how to this in RFC6438. The problem is that flow labels
can be either stateful or stateless (as in RFC6438), and we are
presented with the possibility that a stateless label may collide
with a stateful one. Attempts to split the flow label space were
rejected in IETF. When we added support in Linux for RFC6438, we
could not turn on flow labels by default due to this conflict.
This patch splits the flow label space and should give us
a path to enabling auto flow labels by default for all IPv6 packets.
This is an API change so we need to consider compatibility with
existing deployment. The stateful range is chosen to be the lower
values in hopes that most uses would have chosen small numbers.
Once we resolve the stateless/stateful issue, we can proceed to
look at enabling RFC6438 flow labels by default (starting with
scaled testing).
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This inline has ~500 callsites.
On 04/14/2015 08:37 PM, David Miller wrote:
> That BUG_ON() was added 7 years ago, and I don't remember it ever
> triggering or helping us diagnose something, so just remove it and
> keep the function inlined.
On x86 allyesconfig build:
text data bss dec hex filename
82447071 22255384 20627456 125329911 77861f7 vmlinux4
82441375 22255384 20627456 125324215 7784bb7 vmlinux5prime
Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
CC: Eric W. Biederman <ebiederm@xmission.com>
CC: David S. Miller <davem@davemloft.net>
CC: Jan Engelhardt <jengelh@medozas.de>
CC: Jiri Pirko <jpirko@redhat.com>
CC: linux-kernel@vger.kernel.org
CC: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
This is specified by RFC 7217.
Cc: Erik Kline <ek@google.com>
Cc: Fernando Gont <fgont@si6networks.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Cc: YOSHIFUJI Hideaki/吉藤英明 <hideaki.yoshifuji@miraclelinux.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
