nr_frags can be 8 bits since 256 is plenty of fragments. This allows it to be
packed with tx_flags.
Also by moving ip6_frag_id and dataref (both 4 bytes) next to each other we can
avoid a hole between ip6_frag_id and frag_list on 64 bit systems.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In order to accommodate a 64K buffer we need 64K/PAGE_SIZE plus one more page
in order to allow for a buffer which does not start on a page boundary.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We discovered that TCP stack could retransmit misaligned skbs if a
malicious peer acknowledged sub MSS frame. This currently can happen
only if output interface is non SG enabled : If SG is enabled, tcp
builds headless skbs (all payload is included in fragments), so the tcp
trimming process only removes parts of skb fragments, header stay
aligned.
Some arches cant handle misalignments, so force a head reallocation and
shrink headroom to MAX_TCP_HEADER.
Dont care about misaligments on x86 and PPC (or other arches setting
NET_IP_ALIGN to 0)
This patch introduces __pskb_copy() which can specify the headroom of
new head, and pskb_copy() becomes a wrapper on top of __pskb_copy()
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Given we dont use anymore the struct net_device *dev argument, and this
interface brings litle benefit, remove netdev_{alloc|free}_page(), to
debloat include/linux/skbuff.h a bit.
(Some drivers used a mix of these interfaces and alloc_pages())
When allocating a page given to device for DMA transfer (device to
memory), it makes sense to use a cold one (__GFP_COLD)
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
CC: Dimitris Michailidis <dm@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Only distinct use is checking if NETIF_F_NOCACHE_COPY should be
enabled by default. The check heuristics is altered a bit here,
so it hits other people than before. The default shouldn't be
trusted for performance-critical cases anyway.
For all other uses NETIF_F_NO_CSUM is equivalent to NETIF_F_HW_CSUM.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
v2: add couple missing conversions in drivers
split unexporting netdev_fix_features()
implemented %pNF
convert sock::sk_route_(no?)caps
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
One of the thing we discussed during netdev 2011 conference was the idea
to change some network drivers to allocate/populate their skb at RX
completion time, right before feeding the skb to network stack.
In old days, we allocated skbs when populating the RX ring.
This means bringing into cpu cache sk_buff and skb_shared_info cache
lines (since we clear/initialize them), then 'queue' skb->data to NIC.
By the time NIC fills a frame in skb->data buffer and host can process
it, cpu probably threw away the cache lines from its caches, because lot
of things happened between the allocation and final use.
So the deal would be to allocate only the data buffer for the NIC to
populate its RX ring buffer. And use build_skb() at RX completion to
attach a data buffer (now filled with an ethernet frame) to a new skb,
initialize the skb_shared_info portion, and give the hot skb to network
stack.
build_skb() is the function to allocate an skb, caller providing the
data buffer that should be attached to it. Drivers are expected to call
skb_reserve() right after build_skb() to adjust skb->data to the
Ethernet frame (usually skipping NET_SKB_PAD and NET_IP_ALIGN, but some
drivers might add a hardware provided alignment)
Data provided to build_skb() MUST have been allocated by a prior
kmalloc() call, with enough room to add SKB_DATA_ALIGN(sizeof(struct
skb_shared_info)) bytes at the end of the data without corrupting
incoming frame.
data = kmalloc(NET_SKB_PAD + NET_IP_ALIGN + 1536 +
SKB_DATA_ALIGN(sizeof(struct skb_shared_info)),
GFP_ATOMIC);
...
skb = build_skb(data);
if (!skb) {
recycle_data(data);
} else {
skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN);
...
}
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Eilon Greenstein <eilong@broadcom.com>
CC: Ben Hutchings <bhutchings@solarflare.com>
CC: Tom Herbert <therbert@google.com>
CC: Jamal Hadi Salim <hadi@mojatatu.com>
CC: Stephen Hemminger <shemminger@vyatta.com>
CC: Thomas Graf <tgraf@infradead.org>
CC: Herbert Xu <herbert@gondor.apana.org.au>
CC: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The 802.1X EAPOL handshake hostapd does requires
knowing whether the frame was ack'ed by the peer.
Currently, we fudge this pretty badly by not even
transmitting the frame as a normal data frame but
injecting it with radiotap and getting the status
out of radiotap monitor as well. This is rather
complex, confuses users (mon.wlan0 presence) and
doesn't work with all hardware.
To get rid of that hack, introduce a real wifi TX
status option for data frame transmissions.
This works similar to the existing TX timestamping
in that it reflects the SKB back to the socket's
error queue with a SCM_WIFI_STATUS cmsg that has
an int indicating ACK status (0/1).
Since it is possible that at some point we will
want to have TX timestamping and wifi status in a
single errqueue SKB (there's little point in not
doing that), redefine SO_EE_ORIGIN_TIMESTAMPING
to SO_EE_ORIGIN_TXSTATUS which can collect more
than just the timestamp; keep the old constant
as an alias of course. Currently the internal APIs
don't make that possible, but it wouldn't be hard
to split them up in a way that makes it possible.
Thanks to Neil Horman for helping me figure out
the functions that add the control messages.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Fixes parameter name of skb_frag_dmamap function to silence warning on
make htmldocs.
Signed-off-by: Marcos Paulo de Souza <marcos.mage@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The pair of functions,
* skb_clone_tx_timestamp()
* skb_complete_tx_timestamp()
were designed to allow timestamping in PHY devices. The first
function, called during the MAC driver's hard_xmit method, identifies
PTP protocol packets, clones them, and gives them to the PHY device
driver. The PHY driver may hold onto the packet and deliver it at a
later time using the second function, which adds the packet to the
socket's error queue.
As pointed out by Johannes, nothing prevents the socket from
disappearing while the cloned packet is sitting in the PHY driver
awaiting a timestamp. This patch fixes the issue by taking a reference
on the socket for each such packet. In addition, the comments
regarding the usage of these function are expanded to highlight the
rule that PHY drivers must use skb_complete_tx_timestamp() to release
the packet, in order to release the socket reference, too.
These functions first appeared in v2.6.36.
Reported-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Cc: <stable@vger.kernel.org>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
I've split this bit out of the skb frag destructor patch since it helps enforce
the use of the fragment API.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
I audited all of the callers in the tree and only one of them (pktgen) expects
it to do so. Taking this reference is pretty obviously confusing and error
prone.
In particular I looked at the following commits which switched callers of
(__)skb_frag_set_page to the skb paged fragment api:
6a930b9f16 cxgb3: convert to SKB paged frag API.
5dc3e196ea myri10ge: convert to SKB paged frag API.
0e0634d20d vmxnet3: convert to SKB paged frag API.
86ee8130a4 virtionet: convert to SKB paged frag API.
4a22c4c919 sfc: convert to SKB paged frag API.
18324d690d cassini: convert to SKB paged frag API.
b061b39e3a benet: convert to SKB paged frag API.
b7b6a688d2 bnx2: convert to SKB paged frag API.
804cf14ea5 net: xfrm: convert to SKB frag APIs
ea2ab69379 net: convert core to skb paged frag APIs
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
skb_recycle_check resets the skb if it's eligible for recycling.
However, there are times when a driver might want to optionally
manipulate the skb data with the skb before resetting the skb,
but after it has determined eligibility. We do this by splitting the
eligibility check from the skb reset, creating two inline functions to
accomplish that task.
Signed-off-by: Andy Fleming <afleming@freescale.com>
Acked-by: David Daney <david.daney@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
To ease skb->truesize sanitization, its better to be able to localize
all references to skb frags size.
Define accessors : skb_frag_size() to fetch frag size, and
skb_frag_size_{set|add|sub}() to manipulate it.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
skb truesize currently accounts for sk_buff struct and part of skb head.
kmalloc() roundings are also ignored.
Considering that skb_shared_info is larger than sk_buff, its time to
take it into account for better memory accounting.
This patch introduces SKB_TRUESIZE(X) macro to centralize various
assumptions into a single place.
At skb alloc phase, we put skb_shared_info struct at the exact end of
skb head, to allow a better use of memory (lowering number of
reallocations), since kmalloc() gives us power-of-two memory blocks.
Unless SLUB/SLUB debug is active, both skb->head and skb_shared_info are
aligned to cache lines, as before.
Note: This patch might trigger performance regressions because of
misconfigured protocol stacks, hitting per socket or global memory
limits that were previously not reached. But its a necessary step for a
more accurate memory accounting.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Andi Kleen <ak@linux.intel.com>
CC: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
dev_forward_skb loops an skb back into host networking
stack which might hang on the memory indefinitely.
In particular, this can happen in macvtap in bridged mode.
Copy the userspace fragments to avoid blocking the
sender in that case.
As this patch makes skb_copy_ubufs extern now,
I also added some documentation and made it clear
the SKBTX_DEV_ZEROCOPY flag automatically instead
of doing it in all callers. This can be made into a separate
patch if people feel it's worth it.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
The primary aim is to add skb_frag_(ref|unref) in order to remove the use of
bare get/put_page on SKB pages fragments and to isolate users from subsequent
changes to the skb_frag_t data structure.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: "Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
The l4_rxhash flag was added to the skb structure to indicate
that the rxhash value was computed over the 4 tuple for the
packet which includes the port information in the encapsulated
transport packet. This is used by the stack to preserve the
rxhash value in __skb_rx_tunnel.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>
Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
RX rings should use GFP_KERNEL allocations if possible, add
__netdev_alloc_skb_ip_align() helper to ease this.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Rearrange struct sk_buff members comments to follow their
definition order. Also, add missing comments for ooo_okay
and dropcount members.
Signed-off-by: Daniel Baluta <dbaluta@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds userspace buffers support in skb shared info. A new
struct skb_ubuf_info is needed to maintain the userspace buffers
argument and index, a callback is used to notify userspace to release
the buffers once lower device has done DMA (Last reference to that skb
has gone).
If there is any userspace apps to reference these userspace buffers,
then these userspaces buffers will be copied into kernel. This way we
can prevent userspace apps from holding these userspace buffers too long.
Use destructor_arg to point to the userspace buffer info; a new tx flags
SKBTX_DEV_ZEROCOPY is added for zero-copy buffer check.
Signed-off-by: Shirley Ma <xma@...ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The comment for the skb_tx_timestamp() function suggests calling it just
after a buffer is released to the hardware for transmission. However,
for drivers that free the buffer in an ISR, this produces a race between
the time stamp code and the ISR. This commit changes the comment to advise
placing the call just before handing the buffer over to the hardware.
Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Signed-off-by: David S. Miller <davem@davemloft.net>
Testing of VLAN_FLAG_REORDER_HDR does not belong in vlan_untag
but rather in vlan_do_receive. Otherwise the vlan header
will not be properly put on the packet in the case of
vlan header accelleration.
As we remove the check from vlan_check_reorder_header
rename it vlan_reorder_header to keep the naming clean.
Fix up the skb->pkt_type early so we don't look at the packet
after adding the vlan tag, which guarantees we don't goof
and look at the wrong field.
Use a simple if statement instead of a complicated switch
statement to decided that we need to increment rx_stats
for a multicast packet.
Hopefully at somepoint we will just declare the case where
VLAN_FLAG_REORDER_HDR is cleared as unsupported and remove
the code. Until then this keeps it working correctly.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Acked-by: Changli Gao <xiaosuo@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (27 commits)
bnx2x: allow device properly initialize after hotplug
bnx2x: fix DMAE timeout according to hw specifications
bnx2x: properly handle CFC DEL in cnic flow
bnx2x: call dev_kfree_skb_any instead of dev_kfree_skb
net: filter: move forward declarations to avoid compile warnings
pktgen: refactor pg_init() code
pktgen: use vzalloc_node() instead of vmalloc_node() + memset()
net: skb_trim explicitely check the linearity instead of data_len
ipv4: Give backtrace in ip_rt_bug().
net: avoid synchronize_rcu() in dev_deactivate_many
net: remove synchronize_net() from netdev_set_master()
rtnetlink: ignore NETDEV_RELEASE and NETDEV_JOIN event
net: rename NETDEV_BONDING_DESLAVE to NETDEV_RELEASE
bridge: call NETDEV_JOIN notifiers when add a slave
netpoll: disable netpoll when enslave a device
macvlan: Forward unicast frames in bridge mode to lowerdev
net: Remove linux/prefetch.h include from linux/skbuff.h
ipv4: Include linux/prefetch.h in fib_trie.c
netlabel: Remove prefetches from list handlers.
drivers/net: add prefetch header for prefetch users
...
Fixed up prefetch parts: removed a few duplicate prefetch.h includes,
fixed the location of the igb prefetch.h, took my version of the
skbuff.h code without the extra parentheses etc.
Commit e66eed651f ("list: remove prefetching from regular list
iterators") removed the include of prefetch.h from list.h. The skbuff
list traversal still had them.
Quoth David Miller:
"Please just remove the prefetches.
Those are modelled after list.h as I intend to eventually convert
SKB list handling to "struct list_head" but we're not there yet.
Therefore if we kill prefetches from list.h we should kill it from
these things in skbuff.h too."
Requested-by: David Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The purpose of the check on data_len is to check linearity, so use the inline
helper for this. No overhead and more explicit.
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fixes build errors on s390 and probably other archs as well:
In file included from net/ipv4/ip_forward.c:32:0:
include/net/udp.h: In function 'udp_csum_outgoing':
include/net/udp.h:141:2: error: implicit declaration of function 'prefetch'
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
After commit a715dea3c8 ("net: Always
allocate at least 16 skb frags regardless of page size"), the value
of MAX_SKB_FRAGS can now take on either an "unsigned long" or an
"int" value.
This causes warnings like:
net/packet/af_packet.c: In function ‘tpacket_fill_skb’:
net/packet/af_packet.c:948: warning: format ‘%lu’ expects type ‘long unsigned int’, but argument 2 has type ‘int’
Fix by forcing the constant to be unsigned long, otherwise we have
a situation where the type of a system wide constant is variable.
Signed-off-by: David S. Miller <davem@davemloft.net>
When analysing performance of the cxgb3 on a ppc64 box I noticed that
we weren't doing much GRO merging. It turns out we are limited by the
number of SKB frags:
#define MAX_SKB_FRAGS (65536/PAGE_SIZE + 2)
With a 4kB page size we have 18 frags, but with a 64kB page size we
only have 3 frags.
I ran a single stream TCP bandwidth test to compare the performance of
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch allows rx_handlers to better signalize what to do next to
it's caller. That makes skb->deliver_no_wcard no longer needed.
kernel-doc for rx_handler_result is taken from Nicolas' patch.
Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Reviewed-by: Nicolas de Pesloüan <nicolas.2p.debian@free.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
Quoting Ben Hutchings: we presumably won't be defining features that
can only be enabled on 64-bit architectures.
Occurences found by `grep -r` on net/, drivers/net, include/
[ Move features and vlan_features next to each other in
struct netdev, as per Eric Dumazet's suggestion -DaveM ]
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
The IPv6 tproxy patches split IPv6 defragmentation off of conntrack, but
failed to update the #ifdef stanzas guarding the defragmentation related
fields and code in skbuff and conntrack related code in nf_defrag_ipv6.c.
This patch adds the required #ifdefs so that IPv6 tproxy can truly be used
without connection tracking.
Original report:
http://marc.info/?l=linux-netdev&m=129010118516341&w=2
Reported-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: KOVACS Krisztian <hidden@balabit.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Introduce skb_checksum_start_offset() to replace repetitive calculation.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
Move the calcualation of the Tx hash for a given hash range into a separate
function and define the skb_tx_hash(), which calculates a Tx hash for a
[0; dev->real_num_tx_queues - 1] hash values range, using this
function (__skb_tx_hash()).
Signed-off-by: Vladislav Zolotarov <vladz@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In dev_pick_tx, don't do work in calculating queue
index or setting
the index in the sock unless the device has more than one queue. This
allows the sock to be set only with a queue index of a multi-queue
device which is desirable if device are stacked like in a tunnel.
We also allow the mapping of a socket to queue to be changed. To
maintain in order packet transmission a flag (ooo_okay) has been
added to the sk_buff structure. If a transport layer sets this flag
on a packet, the transmit queue can be changed for the socket.
Presumably, the transport would set this if there was no possbility
of creating OOO packets (for instance, there are no packets in flight
for the socket). This patch includes the modification in TCP output
for setting this flag.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There is no point using RCU for dst we allocate for a very short time
(used once).
Change dst_release() to take DST_NOCACHE into account, but also change
skb_dst_set_noref() to force a refcount increment for such dst.
This is a _huge_ gain, because we dont waste memory to store xx thousand
of dsts. Instead of queueing them to RCU, we can free them instantly.
CPU caches can stay hot, re-using same memory blocks to hold temporary
dsts.
Note : remove unneeded smp_mb__before_atomic_dec(); in dst_release(),
since atomic_dec_return() implies a full memory barrier.
Stress test, 160.000.000 udp frames sent, IP route cache disabled
(DDOS).
Before:
real 0m38.091s
user 0m13.189s
sys 7m53.018s
After:
real 0m29.946s
user 0m12.157s
sys 7m40.605s
For reference, if IP route cache was enabled :
real 0m32.030s
user 0m10.521s
sys 8m15.243s
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
