If the user hasn't actually installed any custom rules, or fiddled
with the default ones, don't go through the whole FIB rules layer.
It's just pure overhead.
Instead do what we do with CONFIG_IP_MULTIPLE_TABLES disabled, check
the individual tables by hand, one by one.
Also, move fib_num_tclassid_users into the ipv4 network namespace.
Signed-off-by: David S. Miller <davem@davemloft.net>
ip_options_compile() can avoid calling fib_compute_spec_dst()
by default, and perform the call only if needed.
David suggested to add a helper to make the call only once.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Causes the handler to use the daddr in the ipv4/ipv6 header when
the route gateway is unspecified (local subnet).
Signed-off-by: David S. Miller <davem@davemloft.net>
When a dst_confirm() happens, mark the confirmation as pending in the
dst. Then on the next packet out, when we have the neigh in-hand, do
the update.
This removes the dependency in dst_confirm() of dst's having an
attached neigh.
While we're here, remove the explicit 'dst' NULL check, all except 2
or 3 call sites ensure it's not NULL. So just fix those cases up.
Signed-off-by: David S. Miller <davem@davemloft.net>
Soon routes will not have a cached neigh attached, nor will we
be able to necessarily go directly to a neigh from an arbitrary
route.
Signed-off-by: David S. Miller <davem@davemloft.net>
The spec_dst uses should be guarded by skb_rtable() being non-NULL
not just the SKB being non-null.
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch generalizes nf_ct_l4proto_net by splitting it into chunks and
moving the corresponding protocol part to where it really belongs to.
To clarify, note that we follow two different approaches to support per-net
depending if it's built-in or run-time loadable protocol tracker.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Gao feng <gaofeng@cn.fujitsu.com>
This patch adds the following structure:
struct netlink_kernel_cfg {
unsigned int groups;
void (*input)(struct sk_buff *skb);
struct mutex *cb_mutex;
};
That can be passed to netlink_kernel_create to set optional configurations
for netlink kernel sockets.
I've populated this structure by looking for NULL and zero parameters at the
existing code. The remaining parameters that always need to be set are still
left in the original interface.
That includes optional parameters for the netlink socket creation. This allows
easy extensibility of this interface in the future.
This patch also adapts all callers to use this new interface.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
If rpfilter is off (or the SKB has an IPSEC path) and there are not
tclassid users, we don't have to do anything at all when
fib_validate_source() is invoked besides setting the itag to zero.
We monitor tclassid uses with a counter (modified only under RTNL and
marked __read_mostly) and we protect the fib_validate_source() real
work with a test against this counter and whether rpfilter is to be
done.
Having a way to know whether we need no tclassid processing or not
also opens the door for future optimized rpfilter algorithms that do
not perform full FIB lookups.
Signed-off-by: David S. Miller <davem@davemloft.net>
Checking for in_dev being NULL is pointless.
In fact, all of our callers have in_dev precomputed already,
so just pass it in and remove the NULL checking.
Signed-off-by: David S. Miller <davem@davemloft.net>
Based upon feedback from Julian Anastasov.
1) Use route flags to determine multicast/broadcast, not the
packet flags.
2) Leave saddr unspecified in flow key.
3) Adjust how we invoke inet_select_addr(). Pass ip_hdr(skb)->saddr as
second arg, and if it was zeronet use link scope.
4) Use loopback as input interface in flow key.
Signed-off-by: David S. Miller <davem@davemloft.net>
The specific destination is the host we direct unicast replies to.
Usually this is the original packet source address, but if we are
responding to a multicast or broadcast packet we have to use something
different.
Specifically we must use the source address we would use if we were to
send a packet to the unicast source of the original packet.
The routing cache precomputes this value, but we want to remove that
precomputation because it creates a hard dependency on the expensive
rpfilter source address validation which we'd like to make cheaper.
There are only three places where this matters:
1) ICMP replies.
2) pktinfo CMSG
3) IP options
Now there will be no real users of rt->rt_spec_dst and we can simply
remove it altogether.
Signed-off-by: David S. Miller <davem@davemloft.net>
Rename it to ip_send_unicast_reply() and add explicit 'saddr'
argument.
This removed one of the few users of rt->rt_spec_dst.
Signed-off-by: David S. Miller <davem@davemloft.net>
This reverts commit c074da2810.
This change has several unwanted side effects:
1) Sockets will cache the DST_NOCACHE route in sk->sk_rx_dst and we'll
thus never create a real cached route.
2) All TCP traffic will use DST_NOCACHE and never use the routing
cache at all.
Signed-off-by: David S. Miller <davem@davemloft.net>
dropwatch wrongly diagnose all received UDP packets as drops.
This patch removes trace_kfree_skb() done in skb_free_datagram_locked().
Locations calling skb_free_datagram_locked() should do it on their own.
As a result, drops are accounted on the right function.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Also fix a needless skb tailroom check for a 4 bytes area
after after each rtnexthop block.
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Also, no need to trim on nlmsg_put() failure, nothing has been added
yet. We also want to use nlmsg_end(), nlmsg_new() and nlmsg_free().
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
DDOS synflood attacks hit badly IP route cache.
On typical machines, this cache is allowed to hold up to 8 Millions dst
entries, 256 bytes for each, for a total of 2GB of memory.
rt_garbage_collect() triggers and tries to cleanup things.
Eventually route cache is disabled but machine is under fire and might
OOM and crash.
This patch exploits the new TCP early demux, to set a nocache
boolean in case incoming TCP frame is for a not yet ESTABLISHED or
TIMEWAIT socket.
This 'nocache' boolean is then used in case dst entry is not found in
route cache, to create an unhashed dst entry (DST_NOCACHE)
SYN-cookie-ACK sent use a similar mechanism (ipv4: tcp: dont cache
output dst for syncookies), so after this patch, a machine is able to
absorb a DDOS synflood attack without polluting its IP route cache.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Hans Schillstrom <hans.schillstrom@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Split sysctl function into smaller chucks to cleanup code and prepare
patches to reduce ifdef pollution.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
l4proto->init contain quite redundant code. We can simplify this
by adding a new parameter l3proto.
This patch prepares that code simplification.
Signed-off-by: Gao feng <gaofeng@cn.fujitsu.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
And account for the fact that, when we are not forwarding, we should
bump statistic counters rather than emit an ICMP response.
RP-filter rejected lookups are still not cached.
Since -EHOSTUNREACH and -ENETUNREACH can now no longer be seen in
ip_rcv_finish(), remove those checks.
Signed-off-by: David S. Miller <davem@davemloft.net>
IPv4 routing cache entries no longer use dst->expires, because the
metrics, PMTU, and redirect information are stored in the inetpeer
cache.
Signed-off-by: David S. Miller <davem@davemloft.net>
The dest port for the call to __inet_lookup_established() in TCP early demux
code is passed with the wrong endian-ness. This causes the lookup to fail
leading to early demux not being used.
Signed-off-by: Vijay Subramanian <subramanian.vijay@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pablo says:
====================
The following four patches provide Netfilter fixes for the cthelper
infrastructure that was recently merged mainstream, they are:
* two fixes for compilation breakage with two different configurations:
- CONFIG_NF_NAT=m and CONFIG_NF_CT_NETLINK=y
- NF_CONNTRACK_EVENTS=n and CONFIG_NETFILTER_NETLINK_QUEUE_CT=y
* two fixes for sparse warnings.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Don't cache output dst for syncookies, as this adds pressure on IP route
cache and rcu subsystem for no gain.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Hans Schillstrom <hans.schillstrom@ericsson.com>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This change is meant to add a control for disabling early socket demux.
The main motivation behind this patch is to provide an option to disable
the feature as it adds an additional cost to routing that reduces overall
throughput by up to 5%. For example one of my systems went from 12.1Mpps
to 11.6 after the early socket demux was added. It looks like the reason
for the regression is that we are now having to perform two lookups, first
the one for an established socket, and then the one for the routing table.
By adding this patch and toggling the value for ip_early_demux to 0 I am
able to get back to the 12.1Mpps I was previously seeing.
[ Move local variables in ip_rcv_finish() down into the basic
block in which they are actually used. -DaveM ]
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
LD init/built-in.o
net/built-in.o:(.data+0x4408): undefined reference to `nf_nat_tcp_seq_adjust'
make: *** [vmlinux] Error 1
This patch adds a new pointer hook (nfq_ct_nat_hook) similar to other existing
in Netfilter to solve our complicated configuration dependencies.
Reported-by: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
No need to use cmpxchg() in inetpeer_invalidate_tree() since we hold
base lock.
Also use correct rcu annotations to remove sparse errors
(CONFIG_SPARSE_RCU_POINTER=y)
net/ipv4/inetpeer.c:144:19: error: incompatible types in comparison
expression (different address spaces)
net/ipv4/inetpeer.c:149:20: error: incompatible types in comparison
expression (different address spaces)
net/ipv4/inetpeer.c:595:10: error: incompatible types in comparison
expression (different address spaces)
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Input packet processing for local sockets involves two major demuxes.
One for the route and one for the socket.
But we can optimize this down to one demux for certain kinds of local
sockets.
Currently we only do this for established TCP sockets, but it could
at least in theory be expanded to other kinds of connections.
If a TCP socket is established then it's identity is fully specified.
This means that whatever input route was used during the three-way
handshake must work equally well for the rest of the connection since
the keys will not change.
Once we move to established state, we cache the receive packet's input
route to use later.
Like the existing cached route in sk->sk_dst_cache used for output
packets, we have to check for route invalidations using dst->obsolete
and dst->ops->check().
Early demux occurs outside of a socket locked section, so when a route
invalidation occurs we defer the fixup of sk->sk_rx_dst until we are
actually inside of established state packet processing and thus have
the socket locked.
Signed-off-by: David S. Miller <davem@davemloft.net>
Don't pretend that inet_protos[] and inet6_protos[] are hashes, thay
are just a straight arrays. Remove all unnecessary hash masking.
Document MAX_INET_PROTOS.
Use RAW_HTABLE_SIZE when appropriate.
Reported-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It makes no sense to execute this limit test every time we create a
routing cache entry.
We can't simply error out on these things since we've silently
accepted and truncated them forever.
Signed-off-by: David S. Miller <davem@davemloft.net>
Pablo says:
====================
This is the second batch of Netfilter updates for net-next. It contains the
kernel changes for the new user-space connection tracking helper
infrastructure.
More details on this infrastructure are provides here:
http://lwn.net/Articles/500196/
Still, I plan to provide some official documentation through the
conntrack-tools user manual on how to setup user-space utilities for this.
So far, it provides two helper in user-space, one for NFSv3 and another for
Oracle/SQLnet/TNS. Yet in my TODO list.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
There are good reasons to supports helpers in user-space instead:
* Rapid connection tracking helper development, as developing code
in user-space is usually faster.
* Reliability: A buggy helper does not crash the kernel. Moreover,
we can monitor the helper process and restart it in case of problems.
* Security: Avoid complex string matching and mangling in kernel-space
running in privileged mode. Going further, we can even think about
running user-space helpers as a non-root process.
* Extensibility: It allows the development of very specific helpers (most
likely non-standard proprietary protocols) that are very likely not to be
accepted for mainline inclusion in the form of kernel-space connection
tracking helpers.
This patch adds the infrastructure to allow the implementation of
user-space conntrack helpers by means of the new nfnetlink subsystem
`nfnetlink_cthelper' and the existing queueing infrastructure
(nfnetlink_queue).
I had to add the new hook NF_IP6_PRI_CONNTRACK_HELPER to register
ipv[4|6]_helper which results from splitting ipv[4|6]_confirm into
two pieces. This change is required not to break NAT sequence
adjustment and conntrack confirmation for traffic that is enqueued
to our user-space conntrack helpers.
Basic operation, in a few steps:
1) Register user-space helper by means of `nfct':
nfct helper add ftp inet tcp
[ It must be a valid existing helper supported by conntrack-tools ]
2) Add rules to enable the FTP user-space helper which is
used to track traffic going to TCP port 21.
For locally generated packets:
iptables -I OUTPUT -t raw -p tcp --dport 21 -j CT --helper ftp
For non-locally generated packets:
iptables -I PREROUTING -t raw -p tcp --dport 21 -j CT --helper ftp
3) Run the test conntrackd in helper mode (see example files under
doc/helper/conntrackd.conf
conntrackd
4) Generate FTP traffic going, if everything is OK, then conntrackd
should create expectations (you can check that with `conntrack':
conntrack -E expect
[NEW] 301 proto=6 src=192.168.1.136 dst=130.89.148.12 sport=0 dport=54037 mask-src=255.255.255.255 mask-dst=255.255.255.255 sport=0 dport=65535 master-src=192.168.1.136 master-dst=130.89.148.12 sport=57127 dport=21 class=0 helper=ftp
[DESTROY] 301 proto=6 src=192.168.1.136 dst=130.89.148.12 sport=0 dport=54037 mask-src=255.255.255.255 mask-dst=255.255.255.255 sport=0 dport=65535 master-src=192.168.1.136 master-dst=130.89.148.12 sport=57127 dport=21 class=0 helper=ftp
This confirms that our test helper is receiving packets including the
conntrack information, and adding expectations in kernel-space.
The user-space helper can also store its private tracking information
in the conntrack structure in the kernel via the CTA_HELP_INFO. The
kernel will consider this a binary blob whose layout is unknown. This
information will be included in the information that is transfered
to user-space via glue code that integrates nfnetlink_queue and
ctnetlink.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
User-space programs that receive traffic via NFQUEUE may mangle packets.
If NAT is enabled, this usually puzzles sequence tracking, leading to
traffic disruptions.
With this patch, nfnl_queue will make the corresponding NAT TCP sequence
adjustment if:
1) The packet has been mangled,
2) the NFQA_CFG_F_CONNTRACK flag has been set, and
3) NAT is detected.
There are some records on the Internet complaning about this issue:
http://stackoverflow.com/questions/260757/packet-mangling-utilities-besides-iptables
By now, we only support TCP since we have no helpers for DCCP or SCTP.
Better to add this if we ever have some helper over those layer 4 protocols.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch uses the new variable length conntrack extensions.
Instead of using union nf_conntrack_help that contain all the
helper private data information, we allocate variable length
area to store the private helper data.
This patch includes the modification of all existing helpers.
It also includes a couple of include header to avoid compilation
warnings.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
With ip_rt_frag_needed() removed, we have to explicitly update PMTU
information in every ICMP error handler.
Create two helper functions to facilitate this.
1) ipv4_sk_update_pmtu()
This updates the PMTU when we have a socket context to
work with.
2) ipv4_update_pmtu()
Raw version, used when no socket context is available. For this
interface, we essentially just pass in explicit arguments for
the flow identity information we would have extracted from the
socket.
And you'll notice that ipv4_sk_update_pmtu() is simply implemented
in terms of ipv4_update_pmtu()
Note that __ip_route_output_key() is used, rather than something like
ip_route_output_flow() or ip_route_output_key(). This is because we
absolutely do not want to end up with a route that does IPSEC
encapsulation and the like. Instead, we only want the route that
would get us to the node described by the outermost IP header.
Reported-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
MAINTAINERS
drivers/net/wireless/iwlwifi/pcie/trans.c
The iwlwifi conflict was resolved by keeping the code added
in 'net' that turns off the buggy chip feature.
The MAINTAINERS conflict was merely overlapping changes, one
change updated all the wireless web site URLs and the other
changed some GIT trees to be Johannes's instead of John's.
Signed-off-by: David S. Miller <davem@davemloft.net>
Add dev_loopback_xmit() in order to deduplicate functions
ip_dev_loopback_xmit() (in net/ipv4/ip_output.c) and
ip6_dev_loopback_xmit() (in net/ipv6/ip6_output.c).
I was about to reinvent the wheel when I noticed that
ip_dev_loopback_xmit() and ip6_dev_loopback_xmit() do exactly what I
need and are not IP-only functions, but they were not available to reuse
elsewhere.
ip6_dev_loopback_xmit() does not have line "skb_dst_force(skb);", but I
understand that this is harmless, and should be in dev_loopback_xmit().
Signed-off-by: Michel Machado <michel@digirati.com.br>
CC: "David S. Miller" <davem@davemloft.net>
CC: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
CC: James Morris <jmorris@namei.org>
CC: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
CC: Patrick McHardy <kaber@trash.net>
CC: Eric Dumazet <edumazet@google.com>
CC: Jiri Pirko <jpirko@redhat.com>
CC: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
CC: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Routing of 127/8 is tradtionally forbidden, we consider
packets from that address block martian when routing and do
not process corresponding ARP requests.
This is a sane default but renders a huge address space
practically unuseable.
The RFC states that no address within the 127/8 block should
ever appear on any network anywhere but it does not forbid
the use of such addresses outside of the loopback device in
particular. For example to address a pool of virtual guests
behind a load balancer.
This patch adds a new interface option 'route_localnet'
enabling routing of the 127/8 address block and processing
of ARP requests on a specific interface.
Note that for the feature to work, the default local route
covering 127/8 dev lo needs to be removed.
Example:
$ sysctl -w net.ipv4.conf.eth0.route_localnet=1
$ ip route del 127.0.0.0/8 dev lo table local
$ ip addr add 127.1.0.1/16 dev eth0
$ ip route flush cache
V2: Fix invalid check to auto flush cache (thanks davem)
Signed-off-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
