When the core networking needs to detect the transport offset in a given
packet and parse it explicitly, a full-blown flow_keys struct is used for
storage.
This patch introduces a smaller keys store, rework the basic flow dissect
helper to use it, and apply this new helper where possible - namely in
skb_probe_transport_header(). The used flow dissector data structures
are renamed to match more closely the new role.

The above gives ~50% performance improvement in micro benchmarking around
skb_probe_transport_header() and ~30% around eth_get_headlen(), mostly due
to the smaller memset. Small, but measurable improvement is measured also
in macro benchmarking.

v1 -> v2: use the new helper in eth_get_headlen() and skb_get_poff(),
  as per DaveM suggestion
Suggested-by: NDavid Miller <davem@davemloft.net>
Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It seems like a historic accident that these return unsigned char *,
and in many places that means casts are required, more often than not.

Make these functions return void * and remove all the casts across
the tree, adding a (u8 *) cast only where the unsigned char pointer
was used directly, all done with the following spatch:

    @@
    expression SKB, LEN;
    typedef u8;
    identifier fn = { skb_push, __skb_push, skb_push_rcsum };
    @@
    - *(fn(SKB, LEN))
    + *(u8 *)fn(SKB, LEN)

    @@
    expression E, SKB, LEN;
    identifier fn = { skb_push, __skb_push, skb_push_rcsum };
    type T;
    @@
    - E = ((T *)(fn(SKB, LEN)))
    + E = fn(SKB, LEN)

    @@
    expression SKB, LEN;
    identifier fn = { skb_push, __skb_push, skb_push_rcsum };
    @@
    - fn(SKB, LEN)[0]
    + *(u8 *)fn(SKB, LEN)

Note that the last part there converts from push(...)[0] to the
more idiomatic *(u8 *)push(...).
Signed-off-by: NJohannes Berg <johannes.berg@intel.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add a skb_gro_flush_final helper to prepare for  consuming
skbs in call_gro_receive. We will extend this helper to not
touch the skb if the skb is consumed by a gro callback with
a followup patch. We need this to handle the upcomming IPsec
ESP callbacks as they reinject the skb to the napi_gro_receive
asynchronous. The handler is used in all gro_receive functions
that can call the ESP gro handlers.
Signed-off-by: NSteffen Klassert <steffen.klassert@secunet.com>

The stack must not pass packets to device drivers that are shorter
than the minimum link layer header length.

Previously, packet sockets would drop packets smaller than or equal
to dev->hard_header_len, but this has false positives. Zero length
payload is used over Ethernet. Other link layer protocols support
variable length headers. Support for validation of these protocols
removed the min length check for all protocols.

Introduce an explicit dev->min_header_len parameter and drop all
packets below this value. Initially, set it to non-zero only for
Ethernet and loopback. Other protocols can follow in a patch to
net-next.

Fixes: 9ed988cd ("packet: validate variable length ll headers")
Reported-by: NSowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Acked-by: NEric Dumazet <edumazet@google.com>
Acked-by: NSowmini Varadhan <sowmini.varadhan@oracle.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds devm_alloc_etherdev_mqs function and devm_alloc_etherdev
macro. These can be used for simpler netdev allocation without having to
care about calling free_netdev.

Thanks to this change drivers, their error paths and removal paths may
get simpler by a bit.
Signed-off-by: NRafał Miłecki <rafal@milecki.pl>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The default TX queue length of Ethernet devices have been a magic
constant of 1000, ever since the initial git import.

Looking back in historical trees[1][2] the value used to be 100,
with the same comment "Ethernet wants good queues". The commit[3]
that changed this from 100 to 1000 didn't describe why, but from
conversations with Robert Olsson it seems that it was changed
when Ethernet devices went from 100Mbit/s to 1Gbit/s, because the
link speed increased x10 the queue size were also adjusted.  This
value later caused much heartache for the bufferbloat community.

This patch merely moves the value into a defined constant.

[1] https://git.kernel.org/cgit/linux/kernel/git/davem/netdev-vger-cvs.git/
[2] https://git.kernel.org/cgit/linux/kernel/git/tglx/history.git/
[3] https://git.kernel.org/tglx/history/c/98921832c232Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently, GRO can do unlimited recursion through the gro_receive
handlers.  This was fixed for tunneling protocols by limiting tunnel GRO
to one level with encap_mark, but both VLAN and TEB still have this
problem.  Thus, the kernel is vulnerable to a stack overflow, if we
receive a packet composed entirely of VLAN headers.

This patch adds a recursion counter to the GRO layer to prevent stack
overflow.  When a gro_receive function hits the recursion limit, GRO is
aborted for this skb and it is processed normally.  This recursion
counter is put in the GRO CB, but could be turned into a percpu counter
if we run out of space in the CB.

Thanks to Vladimír Beneš <vbenes@redhat.com> for the initial bug report.

Fixes: CVE-2016-7039
Fixes: 9b174d88 ("net: Add Transparent Ethernet Bridging GRO support.")
Fixes: 66e5133f ("vlan: Add GRO support for non hardware accelerated vlan")
Signed-off-by: NSabrina Dubroca <sd@queasysnail.net>
Reviewed-by: NJiri Benc <jbenc@redhat.com>
Acked-by: NHannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With centralized MTU checking, there's nothing productive done by
eth_change_mtu that isn't already done in dev_set_mtu, so mark it as
deprecated and remove all usage of it in the kernel. All callers have been
audited for calls to alloc_etherdev* or ether_setup directly, which means
they all have a valid dev->min_mtu and dev->max_mtu. Now eth_change_mtu
prints out a netdev_warn about being deprecated, for the benefit of
out-of-tree drivers that might be utilizing it.

Of note, dvb_net.c actually had dev->mtu = 4096, while using
eth_change_mtu, meaning that if you ever tried changing it's mtu, you
couldn't set it above 1500 anymore. It's now getting dev->max_mtu also set
to 4096 to remedy that.

v2: fix up lantiq_etop, missed breakage due to drive not compiling on x86

CC: netdev@vger.kernel.org
Signed-off-by: NJarod Wilson <jarod@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We want to try and pull the L4 header in if it is available in the first
fragment.  As such add the flag to indicate we want to pull the headers on
the first fragment in.
Signed-off-by: NAlexander Duyck <aduyck@mirantis.com>
Acked-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A repeating pattern in drivers has become to use OF node information
and, if not found, platform specific host information to extract the
ethernet address for a given device.

Currently this is done with a call to of_get_mac_address() and then
some ifdef'd stuff for SPARC.

Consolidate this into a portable routine, and provide the
arch_get_platform_mac_address() weak function hook for all
architectures to implement if they want.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Noticed that the compiler (gcc version 4.8.5 20150623 (Red Hat 4.8.5-4) (GCC))
generated suboptimal assembler code in eth_get_headlen().

This early return coding style is usually not an issue, on super scalar CPUs,
but the compiler choose to put the return statement after this very unlikely
branch, thus creating larger jump down to the likely code path.

Performance wise, I could measure slightly less L1-icache-load-misses
and less branch-misses, and an improvement of 1 nanosec with an IP-forwarding
use-case with 257 bytes packets with ixgbe (CPU i7-4790K @ 4.00GHz).
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The flags argument will allow control of the dissection process (for
instance whether to parse beyond L3).
Signed-off-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch fix double word "the the" in
Documentation/DocBook/networking/API-eth-get-headlen.html
Documentation/DocBook/networking/netdev.html
Documentation/DocBook/networking.xml

These files are generated from comment in source,
so I have to fix comment in net/ethernet/eth.c.
Signed-off-by: NMasanari Iida <standby24x7@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch adds full IPv6 addresses into flow_keys and uses them as
input to the flow hash function. The implementation supports either
IPv4 or IPv6 addresses in a union, and selector is used to determine
how may words to input to jhash2.

We also add flow_get_u32_dst and flow_get_u32_src functions which are
used to get a u32 representation of the source and destination
addresses. For IPv6, ipv6_addr_hash is called. These functions retain
getting the legacy values of src and dst in flow_keys.

With this patch, Ethertype and IP protocol are now included in the
flow hash input.
Signed-off-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When we scan a packet for GRO processing, we want to see the most
common packet types in the front of the offload_base list.

So add a priority field so we can handle this properly.

IPv4/IPv6 get the highest priority with the implicit zero priority
field.

Next comes ethernet with a priority of 10, and then we have the MPLS
types with a priority of 15.
Suggested-by: NEric Dumazet <eric.dumazet@gmail.com>
Suggested-by: NToshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since these functions are defined in flow_dissector.c, move header
declarations from skbuff.h into flow_dissector.h
Signed-off-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This change does two things.  First it fixes a sparse error for the fact
that the __be16 degrades to an integer.  Since that is actually what I am
kind of doing I am simply working around that by forcing both sides of the
comparison to u16.

Also I realized on some compilers I was generating another instruction for
big endian systems such as PowerPC since it was masking the value before
doing the comparison.  So to resolve that I have simply pulled the mask out
and wrapped it in an #ifndef __BIG_ENDIAN.

Lastly I pulled this all out into its own function.  I notices there are
similar checks in a number of other places so this function can be reused
there to help reduce overhead in these paths as well.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Avoid recomputing the Ethernet header location and instead just use the
pointer provided by skb->data.  The problem with using eth_hdr is that the
compiler wasn't smart enough to realize that skb->head + skb->mac_header
was the same thing as skb->data before it added ETH_HLEN.  By just caching
it off before calling skb_pull_inline we can avoid a few unnecessary
instructions.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This change makes it so that we process the address in
is_multicast_ether_addr at the same size as the other calls.  This allows
us to avoid duplicate reads when used with other calls such as
is_zero_ether_addr or eth_addr_copy.  In addition I have added a 64 bit
version of the function so in eth_type_trans we can process the destination
address as a 64 bit value throughout.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This change takes advantage of the fact that ETH_P_802_3_MIN is aligned to
512 so as a result we can actually ignore the lower 8b when comparing the
Ethertype to ETH_P_802_3_MIN.  This allows us to avoid a byte swap by simply
masking the value and comparing it to the byte swapped value for
ETH_P_802_3_MIN.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use the built-in function instead of memset.
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Now that there are no more users kill dev_rebuild_header and all of it's
implementations.

This is long overdue.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Currently the only tunnel protocol that supports GRO with encapsulated
Ethernet is VXLAN. This pulls out the Ethernet code into a proper layer
so that it can be used by other tunnel protocols such as GRE and Geneve.
Signed-off-by: NJesse Gross <jesse@nicira.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This patch updates some of the flow_dissector api so that it can be used to
parse the length of ethernet buffers stored in fragments.  Most of the
changes needed were to __skb_get_poff as it needed to be updated to support
sending a linear buffer instead of a skb.

I have split __skb_get_poff into two functions, the first is skb_get_poff
and it retains the functionality of the original __skb_get_poff.  The other
function is __skb_get_poff which now works much like __skb_flow_dissect in
relation to skb_flow_dissect in that it provides the same functionality but
works with just a data buffer and hlen instead of needing an skb.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Acked-by: NAlexei Starovoitov <ast@plumgrid.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

DSA is currently registering one packet_type function per EtherType it
needs to intercept in the receive path of a DSA-enabled Ethernet device.
Right now we have three of them: trailer, DSA and eDSA, and there might
be more in the future, this will not scale to the addition of new
protocols.

This patch proceeds with adding a new layer of abstraction and two new
functions:

dsa_switch_rcv() which will dispatch into the tag-protocol specific
receive function implemented by net/dsa/tag_*.c

dsa_slave_xmit() which will dispatch into the tag-protocol specific
transmit function implemented by net/dsa/tag_*.c

When we do create the per-port slave network devices, we iterate over
the switch protocol to assign the DSA-specific receive and transmit
operations.

A new fake ethertype value is used: ETH_P_XDSA to illustrate the fact
that this is no longer going to look like ETH_P_DSA or ETH_P_TRAILER
like it used to be.

This allows us to greatly simplify the check in eth_type_trans() and
always override the skb->protocol with ETH_P_XDSA for Ethernet switches
tagged protocol, while also reducing the number repetitive slave
netdevice_ops assignments.
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Extend alloc_netdev{,_mq{,s}}() to take name_assign_type as argument, and convert
all users to pass NET_NAME_UNKNOWN.

Coccinelle patch:

@@
expression sizeof_priv, name, setup, txqs, rxqs, count;
@@

(
-alloc_netdev_mqs(sizeof_priv, name, setup, txqs, rxqs)
+alloc_netdev_mqs(sizeof_priv, name, NET_NAME_UNKNOWN, setup, txqs, rxqs)
|
-alloc_netdev_mq(sizeof_priv, name, setup, count)
+alloc_netdev_mq(sizeof_priv, name, NET_NAME_UNKNOWN, setup, count)
|
-alloc_netdev(sizeof_priv, name, setup)
+alloc_netdev(sizeof_priv, name, NET_NAME_UNKNOWN, setup)
)

v9: move comments here from the wrong commit
Signed-off-by: NTom Gundersen <teg@jklm.no>
Reviewed-by: NDavid Herrmann <dh.herrmann@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

eth_type_trans() can read uninitialized memory as drivers
do not necessarily pull more than 14 bytes in skb->head before
calling it.

As David suggested, we can use skb_header_pointer() to
fix this without breaking some drivers that might not expect
eth_type_trans() pulling 2 additional bytes.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Mark code path's likely/unlikely based on most common usage.
  * Very few devices use dsa tags.
  * Most traffic is Ethernet (not 802.2)
  * No sane person uses trailer type or Novell encapsulation
Signed-off-by: NStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove old legacy comment and weird if condition.
The comment has outlived it's stay and is throwback to some
early net code (before my time). Maybe Dave remembers what it meant.
Signed-off-by: NStephen Hemminger <stephen@networkplumber.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

removed these checkpatch.pl warnings:
net/ethernet/eth.c:61: WARNING: Use #include <linux/uaccess.h> instead of <asm/uaccess.h>
net/ethernet/eth.c:136: WARNING: Prefer netdev_dbg(netdev, ... then dev_dbg(dev, ... then pr_debug(...  to printk(KERN_DEBUG ...
net/ethernet/eth.c:181: ERROR: space prohibited before that close parenthesis ')'
Signed-off-by: NAvinash Kumar <avi.kp.137@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

It's just a duplicate implementation of "%*phC".  Thanks to Joe
Perches for showing that we had exactly this support in the
lib/vsprintf.c code already.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add a new constant ETH_P_802_3_MIN, the minimum ethernet type for
an 802.3 frame. Frames with a lower value in the ethernet type field
are Ethernet II.

Also update all the users of this value that David Miller and
I could find to use the new constant.

Also correct a bug in util.c. The comparison with ETH_P_802_3_MIN
should be >= not >.

As suggested by Jesse Gross.

Compile tested only.

Cc: David Miller <davem@davemloft.net>
Cc: Jesse Gross <jesse@nicira.com>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: John W. Linville <linville@tuxdriver.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Bart De Schuymer <bart.de.schuymer@pandora.be>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Cc: linux-bluetooth@vger.kernel.org
Cc: netfilter-devel@vger.kernel.org
Cc: bridge@lists.linux-foundation.org
Cc: linux-wireless@vger.kernel.org
Cc: linux1394-devel@lists.sourceforge.net
Cc: linux-media@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: dev@openvswitch.org
Acked-by: NMauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: NStefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: NSimon Horman <horms@verge.net.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When we set mac address, software mac address in system and hardware mac
address all need to be updated. Current eth_mac_addr() doesn't allow
callers to implement error handling nicely.

This patch split eth_mac_addr() to prepare part and real commit part,
then we can prepare first, and try to change hardware address, then do
the real commit if hardware address is set successfully.
Signed-off-by: NStefan Hajnoczi <stefanha@gmail.com>
Signed-off-by: NAmos Kong <akong@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

NET_ADDR_SET is set in dev_set_mac_address() no need to alter
dev->addr_assign_type value in drivers.
Signed-off-by: NJiri Pirko <jiri@resnulli.us>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fix incorrect start markers, wrapped summary lines, missing section
breaks, incorrect separators, and some name mismatches.
Signed-off-by: NBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Introduce IFF_LIVE_ADDR_CHANGE priv_flag and use it to disable
netif_running() check in eth_mac_addr()
Signed-off-by: NJiri Pirko <jpirko@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use the new bool function ether_addr_equal_64bits to add
some clarity and reduce the likelihood for misuse of
compare_ether_addr_64bits for sorting.

Done via cocci script:

$ cat compare_ether_addr_64bits.cocci
@@
expression a,b;
@@
-	!compare_ether_addr_64bits(a, b)
+	ether_addr_equal_64bits(a, b)

@@
expression a,b;
@@
-	compare_ether_addr_64bits(a, b)
+	!ether_addr_equal_64bits(a, b)

@@
expression a,b;
@@
-	!ether_addr_equal_64bits(a, b) == 0
+	ether_addr_equal_64bits(a, b)

@@
expression a,b;
@@
-	!ether_addr_equal_64bits(a, b) != 0
+	!ether_addr_equal_64bits(a, b)

@@
expression a,b;
@@
-	ether_addr_equal_64bits(a, b) == 0
+	!ether_addr_equal_64bits(a, b)

@@
expression a,b;
@@
-	ether_addr_equal_64bits(a, b) != 0
+	ether_addr_equal_64bits(a, b)

@@
expression a,b;
@@
-	!!ether_addr_equal_64bits(a, b)
+	ether_addr_equal_64bits(a, b)
Signed-off-by: NJoe Perches <joe@perches.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use of "unsigned int" is preferred to bare "unsigned" in net tree.
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove all #inclusions of asm/system.h preparatory to splitting and killing
it.  Performed with the following command:

perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *`
Signed-off-by: NDavid Howells <dhowells@redhat.com>