linux-toradex.git/include/linux/skbuff.h, branch v3.2.39

net: remove skb_orphan_try()

2012-07-25T03:11:40+00:00

commit 62b1a8ab9b3660bb820d8dfe23148ed6cda38574 upstream.

Orphaning skb in dev_hard_start_xmit() makes bonding behavior
unfriendly for applications sending big UDP bursts : Once packets
pass the bonding device and come to real device, they might hit a full
qdisc and be dropped. Without orphaning, the sender is automatically
throttled because sk->sk_wmemalloc reaches sk->sk_sndbuf (assuming
sk_sndbuf is not too big)

We could try to defer the orphaning adding another test in
dev_hard_start_xmit(), but all this seems of little gain,
now that BQL tends to make packets more likely to be parked
in Qdisc queues instead of NIC TX ring, in cases where performance
matters.

Reverts commits :
fc6055a5ba31 net: Introduce skb_orphan_try()
87fd308cfc6b net: skb_tx_hash() fix relative to skb_orphan_try()
and removes SKBTX_DRV_NEEDS_SK_REF flag

Reported-and-bisected-by: Jean-Michel Hautbois 
Signed-off-by: Eric Dumazet 
Tested-by: Oliver Hartkopp 
Acked-by: Oliver Hartkopp 
Signed-off-by: David S. Miller 
[bwh: Backported to 3.2:
 - Adjust context
 - SKBTX_WIFI_STATUS is not defined]
Signed-off-by: Ben Hutchings

skb: avoid unnecessary reallocations in __skb_cow

2012-06-10T13:42:06+00:00

[ Upstream commit 617c8c11236716dcbda877e764b7bf37c6fd8063 ]

At the beginning of __skb_cow, headroom gets set to a minimum of
NET_SKB_PAD. This causes unnecessary reallocations if the buffer was not
cloned and the headroom is just below NET_SKB_PAD, but still more than the
amount requested by the caller.
This was showing up frequently in my tests on VLAN tx, where
vlan_insert_tag calls skb_cow_head(skb, VLAN_HLEN).

Locally generated packets should have enough headroom, and for forward
paths, we already have NET_SKB_PAD bytes of headroom, so we don't need to
add any extra space here.

Signed-off-by: Felix Fietkau 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Ben Hutchings

tcp: avoid order-1 allocations on wifi and tx path

2012-05-11T12:14:22+00:00

[ This combines upstream commit
  a21d45726acacc963d8baddf74607d9b74e2b723 and the follow-on bug fix
  commit 22b4a4f22da4b39c6f7f679fd35f3d35c91bf851 ]

Marc Merlin reported many order-1 allocations failures in TX path on its
wireless setup, that dont make any sense with MTU=1500 network, and non
SG capable hardware.

After investigation, it turns out TCP uses sk_stream_alloc_skb() and
used as a convention skb_tailroom(skb) to know how many bytes of data
payload could be put in this skb (for non SG capable devices)

Note : these skb used kmalloc-4096 (MTU=1500 + MAX_HEADER +
sizeof(struct skb_shared_info) being above 2048)

Later, mac80211 layer need to add some bytes at the tail of skb
(IEEE80211_ENCRYPT_TAILROOM = 18 bytes) and since no more tailroom is
available has to call pskb_expand_head() and request order-1
allocations.

This patch changes sk_stream_alloc_skb() so that only
sk->sk_prot->max_header bytes of headroom are reserved, and use a new
skb field, avail_size to hold the data payload limit.

This way, order-0 allocations done by TCP stack can leave more than 2 KB
of tailroom and no more allocation is performed in mac80211 layer (or
any layer needing some tailroom)

avail_size is unioned with mark/dropcount, since mark will be set later
in IP stack for output packets. Therefore, skb size is unchanged.

Reported-by: Marc MERLIN 
Tested-by: Marc MERLIN 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
[bwh: Correct commit hash for follow-on bug fix]
Signed-off-by: Ben Hutchings

ipsec: be careful of non existing mac headers

2012-03-19T16:02:21+00:00

[ Upstream commit 03606895cd98c0a628b17324fd7b5ff15db7e3cd ]

Niccolo Belli reported ipsec crashes in case we handle a frame without
mac header (atm in his case)

Before copying mac header, better make sure it is present.

Bugzilla reference:  https://bugzilla.kernel.org/show_bug.cgi?id=42809

Reported-by: Niccolò Belli 
Tested-by: Niccolò Belli 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

include: linux: skbuf.h: Fix parameter documentation

2011-11-01T04:55:48+00:00

Fixes parameter name of skb_frag_dmamap function to silence warning on
make htmldocs.

Signed-off-by: Marcos Paulo de Souza 
Signed-off-by: David S. Miller

Merge branch 'master' of ra.kernel.org:/pub/scm/linux/kernel/git/davem/net

2011-10-24T22:18:09+00:00

net: hold sock reference while processing tx timestamps

2011-10-24T06:54:50+00:00

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 
Signed-off-by: Richard Cochran 
Cc: 
Signed-off-by: Eric Dumazet 
Reviewed-by: Johannes Berg 
Signed-off-by: David S. Miller

net: add opaque struct around skb frag page

2011-10-21T06:52:53+00:00

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 
Signed-off-by: David S. Miller

net: constify skbuff and Qdisc elements

2011-10-20T21:45:43+00:00

Preliminary patch before tcp constification

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

net: do not take an additional reference in skb_frag_set_page

2011-10-19T23:40:39+00:00

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:

6a930b9f163d7e6d9ef692e05616c4ede65038ec cxgb3: convert to SKB paged frag API.
5dc3e196ea21e833128d51eb5b788a070fea1f28 myri10ge: convert to SKB paged frag API.
0e0634d20dd670a89af19af2a686a6cce943ac14 vmxnet3: convert to SKB paged frag API.
86ee8130a46769f73f8f423f99dbf782a09f9233 virtionet: convert to SKB paged frag API.
4a22c4c919c201c2a7f4ee09e672435a3072d875 sfc: convert to SKB paged frag API.
18324d690d6a5028e3c174fc1921447aedead2b8 cassini: convert to SKB paged frag API.
b061b39e3ae18ad75466258cf2116e18fa5bbd80 benet: convert to SKB paged frag API.
b7b6a688d217936459ff5cf1087b2361db952509 bnx2: convert to SKB paged frag API.
804cf14ea5ceca46554d5801e2817bba8116b7e5 net: xfrm: convert to SKB frag APIs
ea2ab69379a941c6f8884e290fdd28c93936a778 net: convert core to skb paged frag APIs

Signed-off-by: Ian Campbell 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller