Pushing original fragments through causes several problems. For example
for matching, frags may not be matched correctly. Take following
example:
<example>
On HOSTA do:
ip6tables -I INPUT -p icmpv6 -j DROP
ip6tables -I INPUT -p icmpv6 -m icmp6 --icmpv6-type 128 -j ACCEPT
and on HOSTB you do:
ping6 HOSTA -s2000 (MTU is 1500)
Incoming echo requests will be filtered out on HOSTA. This issue does
not occur with smaller packets than MTU (where fragmentation does not happen)
</example>
As was discussed previously, the only correct solution seems to be to use
reassembled skb instead of separete frags. Doing this has positive side
effects in reducing sk_buff by one pointer (nfct_reasm) and also the reams
dances in ipvs and conntrack can be removed.
Future plan is to remove net/ipv6/netfilter/nf_conntrack_reasm.c
entirely and use code in net/ipv6/reassembly.c instead.
Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Marcelo Ricardo Leitner <mleitner@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
It is already possible to set/put/renew a label
with IPV6_FLOWLABEL_MGR and setsockopt. This patch
add the possibility to get information about this
label (current value, time before expiration, etc).
It helps application to take decision for a renew
or a release of the label.
v2:
* Add spin_lock to prevent race condition
* return -ENOENT if no result found
* check if flr_action is GET
v3:
* move the spin_lock to protect only the
relevant code
Signed-off-by: Florent Fourcot <florent.fourcot@enst-bretagne.fr>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Just an unnecessary semicolon that should be removed...
Whitespace neatening of macro too.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Sockets marked with IP_PMTUDISC_INTERFACE won't do path mtu discovery,
their sockets won't accept and install new path mtu information and they
will always use the interface mtu for outgoing packets. It is guaranteed
that the packet is not fragmented locally. But we won't set the DF-Flag
on the outgoing frames.
Florian Weimer had the idea to use this flag to ensure DNS servers are
never generating outgoing fragments. They may well be fragmented on the
path, but the server never stores or usees path mtu values, which could
well be forged in an attack.
(The root of the problem with path MTU discovery is that there is
no reliable way to authenticate ICMP Fragmentation Needed But DF Set
messages because they are sent from intermediate routers with their
source addresses, and the IMCP payload will not always contain sufficient
information to identify a flow.)
Recent research in the DNS community showed that it is possible to
implement an attack where DNS cache poisoning is feasible by spoofing
fragments. This work was done by Amir Herzberg and Haya Shulman:
<https://sites.google.com/site/hayashulman/files/fragmentation-poisoning.pdf>
This issue was previously discussed among the DNS community, e.g.
<http://www.ietf.org/mail-archive/web/dnsext/current/msg01204.html>,
without leading to fixes.
This patch depends on the patch "ipv4: fix DO and PROBE pmtu mode
regarding local fragmentation with UFO/CORK" for the enforcement of the
non-fragmentable checks. If other users than ip_append_page/data should
use this semantic too, we have to add a new flag to IPCB(skb)->flags to
suppress local fragmentation and check for this in ip_finish_output.
Many thanks to Florian Weimer for the idea and feedback while implementing
this patch.
Cc: David S. Miller <davem@davemloft.net>
Suggested-by: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
John W. Linville says:
====================
Please accept the following pull request intended for the 3.13 tree...
I had intended to pass most of these to you as much as two weeks ago.
Unfortunately, I failed to account for the effects of bad Internet
connections and my own fatique/laziness while traveling. On the bright
side, at least these have been baking in linux-next for some time!
For the mac80211 bits, Johannes says:
"This time I have two fixes for P2P (which requires not using CCK rates)
and a workaround for APs with broken WMM information."
For the iwlwifi bits, Johannes says:
"I have a few fixes for warnings/issues: one from Alex, fixing scan
timings, one from Emmanuel fixing a WARN_ON in the DVM driver, one from
Stanislaw removing a trigger-happy WARN_ON in the MVM driver and a
change from myself to try to recover when the device isn't processing
commands quickly."
And:
"For this round, I have a lot of changes:
* power management improvements
* BT coexistence improvements/updates
* new device support
* VHT support
* IBSS support (though due to a small bug it requires new firmware)
* various other fixes/improvements."
For the Bluetooth bits, Gustavo says:
"More patches for 3.12, busy times for Bluetooth. More than a 100 commits since
the last pull. The bulk of work comes from Johan and Marcel, they are doing
fixes and improvements all over the Bluetooth subsystem, as the diffstat can
show."
For the ath10k and ath6kl bits, Kalle says:
"Bartosz added support to ath10k for our 10.x AP firmware branch, which
gives us AP specific features and fixes. We still support the main
firmware branch as well just like before, ath10k detects runtime what
firmware is used. Unfortunately the firmware interface in 10.x branch is
somewhat different so there was quite a lot of changes in ath10k for
this.
Michal and Sujith did some performance improvements in ath10k. Vladimir
fixed a compiler warning and Fengguang removed an extra semicolon."
For the NFC bits, Samuel says:
"It's a fairly big one, with the following highlights:
- NFC digital layer implementation: Most NFC chipsets implement the NFC
digital layer in firmware, but others have more basic functionalities
and expect the host to implement the digital layer. This layer sits
below the NFC core.
- Sony's port100 support: This is "soft" NFC USB dongle that expects the
digital layer to be implemented on the host. This is the first user of
our NFC digital stack implementation.
- Secure element API: We now provide a netlink API for enabling,
disabling and discovering NFC attached (embedded or UICC ones) secure
elements. With some userspace help, this allows us to support NFC
payments.
Only the pn544 driver currently supports that API.
- NCI SPI fixes and improvements: In order to support NCI devices over
SPI, we fixed and improved our NCI/SPI implementation. The currently
most deployed NFC NCI chipset, Broadcom's bcm2079x, supports that mode
and we're planning to use our NCI/SPI framework to implement a
driver for it.
- pn533 fragmentation support in target mode: This was the only missing
feature from our pn533 impementation. We now support fragmentation in
both Tx and Rx modes, in target mode."
On top of all that, brcmfmac and rt2x00 both get the usual flurry
of updates. A few other drivers get hit here or there as well.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
As described in commit 5a581b367 (jiffies: Avoid undefined
behavior from signed overflow), according to the C standard
3.4.3p3, overflow of a signed integer results in undefined
behavior.
To fix this, do as the above commit, and do an unsigned
subtraction, and interpreting the result as a signed
two's-complement number. This is based on the theory from
RFC 1982 and is nicely described in wikipedia here:
https://en.wikipedia.org/wiki/Serial_number_arithmetic#General_Solution
A side-note, I have seen practical issues with the previous logic
when dealing with 16-bit, on a 64-bit machine (gcc version
4.4.5). This were 32-bit, which I have not observed issues with.
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Jesper Dangaard Brouer <netoptimizer@brouer.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Slow start now increases cwnd by 1 if an ACK acknowledges some packets,
regardless the number of packets. Consequently slow start performance
is highly dependent on the degree of the stretch ACKs caused by
receiver or network ACK compression mechanisms (e.g., delayed-ACK,
GRO, etc). But slow start algorithm is to send twice the amount of
packets of packets left so it should process a stretch ACK of degree
N as if N ACKs of degree 1, then exits when cwnd exceeds ssthresh. A
follow up patch will use the remainder of the N (if greater than 1)
to adjust cwnd in the congestion avoidance phase.
In addition this patch retires the experimental limited slow start
(LSS) feature. LSS has multiple drawbacks but questionable benefit. The
fractional cwnd increase in LSS requires a loop in slow start even
though it's rarely used. Configuring such an increase step via a global
sysctl on different BDPS seems hard. Finally and most importantly the
slow start overshoot concern is now better covered by the Hybrid slow
start (hystart) enabled by default.
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pablo Neira Ayuso says:
====================
This is another batch containing Netfilter/IPVS updates for your net-next
tree, they are:
* Six patches to make the ipt_CLUSTERIP target support netnamespace,
from Gao feng.
* Two cleanups for the nf_conntrack_acct infrastructure, introducing
a new structure to encapsulate conntrack counters, from Holger
Eitzenberger.
* Fix missing verdict in SCTP support for IPVS, from Daniel Borkmann.
* Skip checksum recalculation in SCTP support for IPVS, also from
Daniel Borkmann.
* Fix behavioural change in xt_socket after IP early demux, from
Florian Westphal.
* Fix bogus large memory allocation in the bitmap port set type in ipset,
from Jozsef Kadlecsik.
* Fix possible compilation issues in the hash netnet set type in ipset,
also from Jozsef Kadlecsik.
* Define constants to identify netlink callback data in ipset dumps,
again from Jozsef Kadlecsik.
* Use sock_gen_put() in xt_socket to replace xt_socket_put_sk,
from Eric Dumazet.
* Improvements for the SH scheduler in IPVS, from Alexander Frolkin.
* Remove extra delay due to unneeded rcu barrier in IPVS net namespace
cleanup path, from Julian Anastasov.
* Save some cycles in ip6t_REJECT by skipping checksum validation in
packets leaving from our stack, from Stanislav Fomichev.
* Fix IPVS_CMD_ATTR_MAX definition in IPVS, larger that required, from
Julian Anastasov.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch fixes a build warning in skb_checksum() by wrapping the
csum_partial() usage in skb_checksum(). The problem is that on a few
architectures, csum_partial is used with prefix asmlinkage whereas
on most architectures it's not. So fix this up generically as we did
with csum_block_add_ext() to match the signature. Introduced by
2817a336d4 ("net: skb_checksum: allow custom update/combine for
walking skb").
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/net/ethernet/emulex/benet/be.h
drivers/net/netconsole.c
net/bridge/br_private.h
Three mostly trivial conflicts.
The net/bridge/br_private.h conflict was a function signature (argument
addition) change overlapping with the extern removals from Joe Perches.
In drivers/net/netconsole.c we had one change adjusting a printk message
whilst another changed "printk(KERN_INFO" into "pr_info(".
Lastly, the emulex change was a new inline function addition overlapping
with Joe Perches's extern removals.
Signed-off-by: David S. Miller <davem@davemloft.net>
This fixes an outstanding bug found through IPVS, where SCTP packets
with skb->data_len > 0 (non-linearized) and empty frag_list, but data
accumulated in frags[] member, are forwarded with incorrect checksum
letting SCTP initial handshake fail on some systems. Linearizing each
SCTP skb in IPVS to prevent that would not be a good solution as
this leads to an additional and unnecessary performance penalty on
the load-balancer itself for no good reason (as we actually only want
to update the checksum, and can do that in a different/better way
presented here).
The actual problem is elsewhere, namely, that SCTP's checksumming
in sctp_compute_cksum() does not take frags[] into account like
skb_checksum() does. So while we are fixing this up, we better reuse
the existing code that we have anyway in __skb_checksum() and use it
for walking through the data doing checksumming. This will not only
fix this issue, but also consolidates some SCTP code with core
sk_buff code, bringing it closer together and removing respectively
avoiding reimplementation of skb_checksum() for no good reason.
As crc32c() can use hardware implementation within the crypto layer,
we leave that intact (it wraps around / falls back to e.g. slice-by-8
algorithm in __crc32c_le() otherwise); plus use the __crc32c_le_combine()
combinator for crc32c blocks.
Also, we remove all other SCTP checksumming code, so that we only
have to use sctp_compute_cksum() from now on; for doing that, we need
to transform SCTP checkumming in output path slightly, and can leave
the rest intact.
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, skb_checksum walks over 1) linearized, 2) frags[], and
3) frag_list data and calculats the one's complement, a 32 bit
result suitable for feeding into itself or csum_tcpudp_magic(),
but unsuitable for SCTP as we're calculating CRC32c there.
Hence, in order to not re-implement the very same function in
SCTP (and maybe other protocols) over and over again, use an
update() + combine() callback internally to allow for walking
over the skb with different algorithms.
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Encapsulate counters for both directions into nf_conn_acct. During
that process also consistently name pointers to the extend 'acct',
not 'counters'. This patch is a cleanup.
Signed-off-by: Holger Eitzenberger <holger@eitzenberger.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Conflicts:
net/xfrm/xfrm_policy.c
Minor merge conflict in xfrm_policy.c, consisting of overlapping
changes which were trivial to resolve.
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch removes the burden from the NIC drivers to check if the
vxlan driver is enabled in the kernel and also makes available
the vxlan headrooms to them.
Signed-off-by: Joseph Gasparakis <joseph.gasparakis@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
The code for privacy extentions is very mature, and making it
configurable only gives marginal memory/code savings in exchange
for obfuscation and hard to read code via CPP ifdef'ery.
Signed-off-by: David S. Miller <davem@davemloft.net>
This can be used by a driver to prepare skbs for transmission, which were
obtained via functions such as ieee80211_probereq_get or
ieee80211_nullfunc_get.
This is useful for drivers that want to send those frames directly, but
need rate control information to be prepared first.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Drivers can now use this to parse the regulatory request and
be more verbose when needed.
Signed-off-by: Luis R. Rodriguez <mcgrof@do-not-panic.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
