ip_options_echo() assumes struct ip_options is provided in &IPCB(skb)->opt
Lets break this assumption, but provide a helper to not change all call points.
ip_send_unicast_reply() gets a new struct ip_options pointer.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Current ICMP rate limiting uses inetpeer cache, which is an RBL tree
protected by a lock, meaning that hosts can be stuck hard if all cpus
want to check ICMP limits.
When say a DNS or NTP server process is restarted, inetpeer tree grows
quick and machine comes to its knees.
iptables can not help because the bottleneck happens before ICMP
messages are even cooked and sent.
This patch adds a new global limitation, using a token bucket filter,
controlled by two new sysctl :
icmp_msgs_per_sec - INTEGER
Limit maximal number of ICMP packets sent per second from this host.
Only messages whose type matches icmp_ratemask are
controlled by this limit.
Default: 1000
icmp_msgs_burst - INTEGER
icmp_msgs_per_sec controls number of ICMP packets sent per second,
while icmp_msgs_burst controls the burst size of these packets.
Default: 50
Note that if we really want to send millions of ICMP messages per
second, we might extend idea and infra added in commit 04ca6973f7
("ip: make IP identifiers less predictable") :
add a token bucket in the ip_idents hash and no longer rely on inetpeer.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net.ipv4.ip_nonlocal_bind sysctl was global to all network
namespaces. This patch allows to set a different value for each
network namespace.
Signed-off-by: Vincent Bernat <vincent@bernat.im>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add inet_gro_compute_pseudo and ip6_gro_compute_pseudo. These are
the logical equivalents of inet_compute_pseudo and ip6_compute_pseudo
for GRO path. The IP header is taken from skb_gro_network_header.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We create a proc dir for each network device, this will cause
conflicts when the devices have name "all" or "default".
Rather than emitting an ugly kernel warning, we could just
fail earlier by checking the device name.
Reported-by: Stephane Chazelas <stephane.chazelas@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In "Counting Packets Sent Between Arbitrary Internet Hosts", Jeffrey and
Jedidiah describe ways exploiting linux IP identifier generation to
infer whether two machines are exchanging packets.
With commit 73f156a6e8 ("inetpeer: get rid of ip_id_count"), we
changed IP id generation, but this does not really prevent this
side-channel technique.
This patch adds a random amount of perturbation so that IP identifiers
for a given destination [1] are no longer monotonically increasing after
an idle period.
Note that prandom_u32_max(1) returns 0, so if generator is used at most
once per jiffy, this patch inserts no hole in the ID suite and do not
increase collision probability.
This is jiffies based, so in the worst case (HZ=1000), the id can
rollover after ~65 seconds of idle time, which should be fine.
We also change the hash used in __ip_select_ident() to not only hash
on daddr, but also saddr and protocol, so that ICMP probes can not be
used to infer information for other protocols.
For IPv6, adds saddr into the hash as well, but not nexthdr.
If I ping the patched target, we can see ID are now hard to predict.
21:57:11.008086 IP (...)
A > target: ICMP echo request, seq 1, length 64
21:57:11.010752 IP (... id 2081 ...)
target > A: ICMP echo reply, seq 1, length 64
21:57:12.013133 IP (...)
A > target: ICMP echo request, seq 2, length 64
21:57:12.015737 IP (... id 3039 ...)
target > A: ICMP echo reply, seq 2, length 64
21:57:13.016580 IP (...)
A > target: ICMP echo request, seq 3, length 64
21:57:13.019251 IP (... id 3437 ...)
target > A: ICMP echo reply, seq 3, length 64
[1] TCP sessions uses a per flow ID generator not changed by this patch.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Jeffrey Knockel <jeffk@cs.unm.edu>
Reported-by: Jedidiah R. Crandall <crandall@cs.unm.edu>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Hannes Frederic Sowa <hannes@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The 'nqueues' counter is protected by the lru list lock,
once thats removed this needs to be converted to atomic
counter. Given this isn't used for anything except for
reporting it to userspace via /proc, just remove it.
We still report the memory currently used by fragment
reassembly queues.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
For a connected socket we can precompute the flow hash for setting
in skb->hash on output. This is a performance advantage over
calculating the skb->hash for every packet on the connection. The
computation is done using the common hash algorithm to be consistent
with computations done for packets of the connection in other states
where thers is no socket (e.g. time-wait, syn-recv, syn-cookies).
This patch adds sk_txhash to the sock structure. inet_set_txhash and
ip6_set_txhash functions are added which are called from points in
TCP and UDP where socket moves to established state.
skb_set_hash_from_sk is a function which sets skb->hash from the
sock txhash value. This is called in UDP and TCP transmit path when
transmitting within the context of a socket.
Tested: ran super_netperf with 200 TCP_RR streams over a vxlan
interface (in this case skb_get_hash called on every TX packet to
create a UDP source port).
Before fix:
95.02% CPU utilization
154/256/505 90/95/99% latencies
1.13042e+06 tps
Time in functions:
0.28% skb_flow_dissect
0.21% __skb_get_hash
After fix:
94.95% CPU utilization
156/254/485 90/95/99% latencies
1.15447e+06
Neither __skb_get_hash nor skb_flow_dissect appear in perf
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Ideally, we would need to generate IP ID using a per destination IP
generator.
linux kernels used inet_peer cache for this purpose, but this had a huge
cost on servers disabling MTU discovery.
1) each inet_peer struct consumes 192 bytes
2) inetpeer cache uses a binary tree of inet_peer structs,
with a nominal size of ~66000 elements under load.
3) lookups in this tree are hitting a lot of cache lines, as tree depth
is about 20.
4) If server deals with many tcp flows, we have a high probability of
not finding the inet_peer, allocating a fresh one, inserting it in
the tree with same initial ip_id_count, (cf secure_ip_id())
5) We garbage collect inet_peer aggressively.
IP ID generation do not have to be 'perfect'
Goal is trying to avoid duplicates in a short period of time,
so that reassembly units have a chance to complete reassembly of
fragments belonging to one message before receiving other fragments
with a recycled ID.
We simply use an array of generators, and a Jenkin hash using the dst IP
as a key.
ipv6_select_ident() is put back into net/ipv6/ip6_output.c where it
belongs (it is only used from this file)
secure_ip_id() and secure_ipv6_id() no longer are needed.
Rename ip_select_ident_more() to ip_select_ident_segs() to avoid
unnecessary decrement/increment of the number of segments.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
> include/net/ip.h:211:5: warning: "CONFIG_SYSCTL" is not defined [-Wundef]
> #if CONFIG_SYSCTL
> ^
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
ip_local_port_range is already per netns, so should ip_local_reserved_ports
be. And since it is none by default we don't actually need it when we don't
enable CONFIG_SYSCTL.
By the way, rename inet_is_reserved_local_port() to inet_is_local_reserved_port()
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Kernel-originated IP packets that have no user socket associated
with them (e.g., ICMP errors and echo replies, TCP RSTs, etc.)
are emitted with a mark of zero. Add a sysctl to make them have
the same mark as the packet they are replying to.
This allows an administrator that wishes to do so to use
mark-based routing, firewalling, etc. for these replies by
marking the original packets inbound.
Tested using user-mode linux:
- ICMP/ICMPv6 echo replies and errors.
- TCP RST packets (IPv4 and IPv6).
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
commit 8f0ea0fe3a (snmp: reduce percpu needs by 50%)
reduced snmp array size to 1, so technically it doesn't have to be
an array any more. What's more, after the following commit:
commit 933393f58f
Date: Thu Dec 22 11:58:51 2011 -0600
percpu: Remove irqsafe_cpu_xxx variants
We simply say that regular this_cpu use must be safe regardless of
preemption and interrupt state. That has no material change for x86
and s390 implementations of this_cpu operations. However, arches that
do not provide their own implementation for this_cpu operations will
now get code generated that disables interrupts instead of preemption.
probably no arch wants to have SNMP_ARRAY_SZ == 2. At least after
almost 3 years, no one complains.
So, just convert the array to a single pointer and remove snmp_mib_init()
and snmp_mib_free() as well.
Cc: Christoph Lameter <cl@linux.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Call skb_checksum_init instead of private functions.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In the dst->output() path for ipv4, the code assumes the skb it has to
transmit is attached to an inet socket, specifically via
ip_mc_output() : The sk_mc_loop() test triggers a WARN_ON() when the
provider of the packet is an AF_PACKET socket.
The dst->output() method gets an additional 'struct sock *sk'
parameter. This needs a cascade of changes so that this parameter can
be propagated from vxlan to final consumer.
Fixes: 8f646c922d ("vxlan: keep original skb ownership")
Reported-by: lucien xin <lucien.xin@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
ip_queue_xmit() assumes the skb it has to transmit is attached to an
inet socket. Commit 31c70d5956 ("l2tp: keep original skb ownership")
changed l2tp to not change skb ownership and thus broke this assumption.
One fix is to add a new 'struct sock *sk' parameter to ip_queue_xmit(),
so that we do not assume skb->sk points to the socket used by l2tp
tunnel.
Fixes: 31c70d5956 ("l2tp: keep original skb ownership")
Reported-by: Zhan Jianyu <nasa4836@gmail.com>
Tested-by: Zhan Jianyu <nasa4836@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Can be invoked from non-BH context.
Based upon a patch by Eric Dumazet.
Fixes: f19c29e3e3 ("tcp: snmp stats for Fast Open, SYN rtx, and data pkts")
Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
IP_PMTUDISC_INTERFACE has a design error: because it does not allow the
generation of fragments if the interface mtu is exceeded, it is very
hard to make use of this option in already deployed name server software
for which I introduced this option.
This patch adds yet another new IP_MTU_DISCOVER option to not honor any
path mtu information and not accepting new icmp notifications destined for
the socket this option is enabled on. But we allow outgoing fragmentation
in case the packet size exceeds the outgoing interface mtu.
As such this new option can be used as a drop-in replacement for
IP_PMTUDISC_DONT, which is currently in use by most name server software
making the adoption of this option very smooth and easy.
The original advantage of IP_PMTUDISC_INTERFACE is still maintained:
ignoring incoming path MTU updates and not honoring discovered path MTUs
in the output path.
Fixes: 482fc6094a ("ipv4: introduce new IP_MTU_DISCOVER mode IP_PMTUDISC_INTERFACE")
Cc: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
In case we decide in udp6_sendmsg to send the packet down the ipv4
udp_sendmsg path because the destination is either of family AF_INET or
the destination is an ipv4 mapped ipv6 address, we don't honor the
maybe specified ipv4 mapped ipv6 address in IPV6_PKTINFO.
We simply can check for this option in ip_cmsg_send because no calls to
ipv6 module functions are needed to do so.
Reported-by: Gert Doering <gert@space.net>
Cc: Tore Anderson <tore@fud.no>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
We currently don't report IPV6_RECVPKTINFO in cmsg access ancillary data
for IPv4 datagrams on IPv6 sockets.
This patch splits the ip6_datagram_recv_ctl into two functions, one
which handles both protocol families, AF_INET and AF_INET6, while the
ip6_datagram_recv_specific_ctl only handles IPv6 cmsg data.
ip6_datagram_recv_*_ctl never reported back any errors, so we can make
them return void. Also provide a helper for protocols which don't offer dual
personality to further use ip6_datagram_recv_ctl, which is exported to
modules.
I needed to shuffle the code for ping around a bit to make it easier to
implement dual personality for ping ipv6 sockets in future.
Reported-by: Gert Doering <gert@space.net>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
While forwarding we should not use the protocol path mtu to calculate
the mtu for a forwarded packet but instead use the interface mtu.
We mark forwarded skbs in ip_forward with IPSKB_FORWARDED, which was
introduced for multicast forwarding. But as it does not conflict with
our usage in unicast code path it is perfect for reuse.
I moved the functions ip_sk_accept_pmtu, ip_sk_use_pmtu and ip_skb_dst_mtu
along with the new ip_dst_mtu_maybe_forward to net/ip.h to fix circular
dependencies because of IPSKB_FORWARDED.
Because someone might have written a software which does probe
destinations manually and expects the kernel to honour those path mtus
I introduced a new per-namespace "ip_forward_use_pmtu" knob so someone
can disable this new behaviour. We also still use mtus which are locked on a
route for forwarding.
The reason for this change is, that path mtus information can be injected
into the kernel via e.g. icmp_err protocol handler without verification
of local sockets. As such, this could cause the IPv4 forwarding path to
wrongfully emit fragmentation needed notifications or start to fragment
packets along a path.
Tunnel and ipsec output paths clear IPCB again, thus IPSKB_FORWARDED
won't be set and further fragmentation logic will use the path mtu to
determine the fragmentation size. They also recheck packet size with
help of path mtu discovery and report appropriate errors.
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Miller <davem@davemloft.net>
Cc: John Heffner <johnwheffner@gmail.com>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
The other field in ipv4_config, log_martians, was converted to a
per-interface setting, so we can just remove the whole structure.
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
