linux-stable.git/net/core/skbuff.c, branch linux-3.17.y Linux kernel stable tree gro: fix aggregation for skb using frag_list 2014-09-29T19:17:59+00:00 Eric Dumazet edumazet@google.com 2014-09-29T17:34:29+00:00 73d3fe6d1c6d840763ceafa9afae0aaafa18c4b5 In commit 8a29111c7ca6 ("net: gro: allow to build full sized skb") I added a regression for linear skb that traditionally force GRO to use the frag_list fallback. Erez Shitrit found that at most two segments were aggregated and the "if (skb_gro_len(p) != pinfo->gso_size)" test was failing. This is because pinfo at this spot still points to the last skb in the chain, instead of the first one, where we find the correct gso_size information. Signed-off-by: Eric Dumazet <edumazet@google.com> Fixes: 8a29111c7ca6 ("net: gro: allow to build full sized skb") Reported-by: Erez Shitrit <erezsh@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
In commit 8a29111c7ca6 ("net: gro: allow to build full sized skb")
I added a regression for linear skb that traditionally force GRO
to use the frag_list fallback.

Erez Shitrit found that at most two segments were aggregated and
the "if (skb_gro_len(p) != pinfo->gso_size)" test was failing.

This is because pinfo at this spot still points to the last skb in the
chain, instead of the first one, where we find the correct gso_size
information.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: 8a29111c7ca6 ("net: gro: allow to build full sized skb")
Reported-by: Erez Shitrit <erezsh@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: treewide: Fix typo found in DocBook/networking.xml 2014-09-06T00:35:28+00:00 Masanari Iida standby24x7@gmail.com 2014-09-04T14:44:36+00:00 e793c0f70e9bdf4a2e71c151a1a3cf85c4db92ad This patch fix spelling typo found in DocBook/networking.xml. It is because the neworking.xml is generated from comments in the source, I have to fix typo in comments within the source. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: David S. Miller <davem@davemloft.net> 
This patch fix spelling typo found in DocBook/networking.xml.
It is because the neworking.xml is generated from comments
in the source, I have to fix typo in comments within the source.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: Always untag vlan-tagged traffic on input. 2014-08-11T19:16:51+00:00 Vlad Yasevich vyasevic@redhat.com 2014-08-08T18:42:13+00:00 0d5501c1c828fb97d02af50aa9d2b1a5498b94e4 Currently the functionality to untag traffic on input resides as part of the vlan module and is build only when VLAN support is enabled in the kernel. When VLAN is disabled, the function vlan_untag() turns into a stub and doesn't really untag the packets. This seems to create an interesting interaction between VMs supporting checksum offloading and some network drivers. There are some drivers that do not allow the user to change tx-vlan-offload feature of the driver. These drivers also seem to assume that any VLAN-tagged traffic they transmit will have the vlan information in the vlan_tci and not in the vlan header already in the skb. When transmitting skbs that already have tagged data with partial checksum set, the checksum doesn't appear to be updated correctly by the card thus resulting in a failure to establish TCP connections. The following is a packet trace taken on the receiver where a sender is a VM with a VLAN configued. The host VM is running on doest not have VLAN support and the outging interface on the host is tg3: 10:12:43.503055 52:54:00:ae:42:3f > 28:d2:44:7d:c2:de, ethertype 802.1Q (0x8100), length 78: vlan 100, p 0, ethertype IPv4, (tos 0x0, ttl 64, id 27243, offset 0, flags [DF], proto TCP (6), length 60) 10.0.100.1.58545 > 10.0.100.10.ircu-2: Flags [S], cksum 0xdc39 (incorrect -> 0x48d9), seq 1069378582, win 29200, options [mss 1460,sackOK,TS val 4294837885 ecr 0,nop,wscale 7], length 0 10:12:44.505556 52:54:00:ae:42:3f > 28:d2:44:7d:c2:de, ethertype 802.1Q (0x8100), length 78: vlan 100, p 0, ethertype IPv4, (tos 0x0, ttl 64, id 27244, offset 0, flags [DF], proto TCP (6), length 60) 10.0.100.1.58545 > 10.0.100.10.ircu-2: Flags [S], cksum 0xdc39 (incorrect -> 0x44ee), seq 1069378582, win 29200, options [mss 1460,sackOK,TS val 4294838888 ecr 0,nop,wscale 7], length 0 This connection finally times out. I've only access to the TG3 hardware in this configuration thus have only tested this with TG3 driver. There are a lot of other drivers that do not permit user changes to vlan acceleration features, and I don't know if they all suffere from a similar issue. The patch attempt to fix this another way. It moves the vlan header stipping code out of the vlan module and always builds it into the kernel network core. This way, even if vlan is not supported on a virtualizatoin host, the virtual machines running on top of such host will still work with VLANs enabled. CC: Patrick McHardy <kaber@trash.net> CC: Nithin Nayak Sujir <nsujir@broadcom.com> CC: Michael Chan <mchan@broadcom.com> CC: Jiri Pirko <jiri@resnulli.us> Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com> Acked-by: Jiri Pirko <jiri@resnulli.us> Signed-off-by: David S. Miller <davem@davemloft.net> 
Currently the functionality to untag traffic on input resides
as part of the vlan module and is build only when VLAN support
is enabled in the kernel.  When VLAN is disabled, the function
vlan_untag() turns into a stub and doesn't really untag the
packets.  This seems to create an interesting interaction
between VMs supporting checksum offloading and some network drivers.

There are some drivers that do not allow the user to change
tx-vlan-offload feature of the driver.  These drivers also seem
to assume that any VLAN-tagged traffic they transmit will
have the vlan information in the vlan_tci and not in the vlan
header already in the skb.  When transmitting skbs that already
have tagged data with partial checksum set, the checksum doesn't
appear to be updated correctly by the card thus resulting in a
failure to establish TCP connections.

The following is a packet trace taken on the receiver where a
sender is a VM with a VLAN configued.  The host VM is running on
doest not have VLAN support and the outging interface on the
host is tg3:
10:12:43.503055 52:54:00:ae:42:3f > 28:d2:44:7d:c2:de, ethertype 802.1Q
(0x8100), length 78: vlan 100, p 0, ethertype IPv4, (tos 0x0, ttl 64, id 27243,
offset 0, flags [DF], proto TCP (6), length 60)
    10.0.100.1.58545 > 10.0.100.10.ircu-2: Flags [S], cksum 0xdc39 (incorrect
-> 0x48d9), seq 1069378582, win 29200, options [mss 1460,sackOK,TS val
4294837885 ecr 0,nop,wscale 7], length 0
10:12:44.505556 52:54:00:ae:42:3f > 28:d2:44:7d:c2:de, ethertype 802.1Q
(0x8100), length 78: vlan 100, p 0, ethertype IPv4, (tos 0x0, ttl 64, id 27244,
offset 0, flags [DF], proto TCP (6), length 60)
    10.0.100.1.58545 > 10.0.100.10.ircu-2: Flags [S], cksum 0xdc39 (incorrect
-> 0x44ee), seq 1069378582, win 29200, options [mss 1460,sackOK,TS val
4294838888 ecr 0,nop,wscale 7], length 0

This connection finally times out.

I've only access to the TG3 hardware in this configuration thus have
only tested this with TG3 driver.  There are a lot of other drivers
that do not permit user changes to vlan acceleration features, and
I don't know if they all suffere from a similar issue.

The patch attempt to fix this another way.  It moves the vlan header
stipping code out of the vlan module and always builds it into the
kernel network core.  This way, even if vlan is not supported on
a virtualizatoin host, the virtual machines running on top of such
host will still work with VLANs enabled.

CC: Patrick McHardy <kaber@trash.net>
CC: Nithin Nayak Sujir <nsujir@broadcom.com>
CC: Michael Chan <mchan@broadcom.com>
CC: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com>
Acked-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2014-08-06T01:46:26+00:00 David S. Miller davem@davemloft.net 2014-08-06T01:46:26+00:00 d247b6ab3ce6dd43665780865ec5fa145d9ab6bd Conflicts: drivers/net/Makefile net/ipv6/sysctl_net_ipv6.c Two ipv6_table_template[] additions overlap, so the index of the ipv6_table[x] assignments needed to be adjusted. In the drivers/net/Makefile case, we've gotten rid of the garbage whereby we had to list every single USB networking driver in the top-level Makefile, there is just one "USB_NETWORKING" that guards everything. Signed-off-by: David S. Miller <davem@davemloft.net> 
Conflicts:
	drivers/net/Makefile
	net/ipv6/sysctl_net_ipv6.c

Two ipv6_table_template[] additions overlap, so the index
of the ipv6_table[x] assignments needed to be adjusted.

In the drivers/net/Makefile case, we've gotten rid of the
garbage whereby we had to list every single USB networking
driver in the top-level Makefile, there is just one
"USB_NETWORKING" that guards everything.

Signed-off-by: David S. Miller <davem@davemloft.net>
net-timestamp: TCP timestamping 2014-08-05T23:35:54+00:00 Willem de Bruijn willemb@google.com 2014-08-05T02:11:49+00:00 4ed2d765dfaccff5ebdac68e2064b59125033a3b TCP timestamping extends SO_TIMESTAMPING to bytestreams. Bytestreams do not have a 1:1 relationship between send() buffers and network packets. The feature interprets a send call on a bytestream as a request for a timestamp for the last byte in that send() buffer. The choice corresponds to a request for a timestamp when all bytes in the buffer have been sent. That assumption depends on in-order kernel transmission. This is the common case. That said, it is possible to construct a traffic shaping tree that would result in reordering. The guarantee is strong, then, but not ironclad. This implementation supports send and sendpages (splice). GSO replaces one large packet with multiple smaller packets. This patch also copies the option into the correct smaller packet. This patch does not yet support timestamping on data in an initial TCP Fast Open SYN, because that takes a very different data path. If ID generation in ee_data is enabled, bytestream timestamps return a byte offset, instead of the packet counter for datagrams. The implementation supports a single timestamp per packet. It silenty replaces requests for previous timestamps. To avoid missing tstamps, flush the tcp queue by disabling Nagle, cork and autocork. Missing tstamps can be detected by offset when the ee_data ID is enabled. Implementation details: - On GSO, the timestamping code can be included in the main loop. I moved it into its own loop to reduce the impact on the common case to a single branch. - To avoid leaking the absolute seqno to userspace, the offset returned in ee_data must always be relative. It is an offset between an skb and sk field. The first is always set (also for GSO & ACK). The second must also never be uninitialized. Only allow the ID option on sockets in the ESTABLISHED state, for which the seqno is available. Never reset it to zero (instead, move it to the current seqno when reenabling the option). Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
TCP timestamping extends SO_TIMESTAMPING to bytestreams.

Bytestreams do not have a 1:1 relationship between send() buffers and
network packets. The feature interprets a send call on a bytestream as
a request for a timestamp for the last byte in that send() buffer.

The choice corresponds to a request for a timestamp when all bytes in
the buffer have been sent. That assumption depends on in-order kernel
transmission. This is the common case. That said, it is possible to
construct a traffic shaping tree that would result in reordering.
The guarantee is strong, then, but not ironclad.

This implementation supports send and sendpages (splice). GSO replaces
one large packet with multiple smaller packets. This patch also copies
the option into the correct smaller packet.

This patch does not yet support timestamping on data in an initial TCP
Fast Open SYN, because that takes a very different data path.

If ID generation in ee_data is enabled, bytestream timestamps return a
byte offset, instead of the packet counter for datagrams.

The implementation supports a single timestamp per packet. It silenty
replaces requests for previous timestamps. To avoid missing tstamps,
flush the tcp queue by disabling Nagle, cork and autocork. Missing
tstamps can be detected by offset when the ee_data ID is enabled.

Implementation details:

- On GSO, the timestamping code can be included in the main loop. I
moved it into its own loop to reduce the impact on the common case
to a single branch.

- To avoid leaking the absolute seqno to userspace, the offset
returned in ee_data must always be relative. It is an offset between
an skb and sk field. The first is always set (also for GSO & ACK).
The second must also never be uninitialized. Only allow the ID
option on sockets in the ESTABLISHED state, for which the seqno
is available. Never reset it to zero (instead, move it to the
current seqno when reenabling the option).

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net-timestamp: SCHED timestamp on entering packet scheduler 2014-08-05T23:35:54+00:00 Willem de Bruijn willemb@google.com 2014-08-05T02:11:48+00:00 e7fd2885385157d46c85f282fc6d7d297db43e1f Kernel transmit latency is often incurred in the packet scheduler. Introduce a new timestamp on transmission just before entering the scheduler. When data travels through multiple devices (bonding, tunneling, ...) each device will export an individual timestamp. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Kernel transmit latency is often incurred in the packet scheduler.
Introduce a new timestamp on transmission just before entering the
scheduler. When data travels through multiple devices (bonding,
tunneling, ...) each device will export an individual timestamp.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net-timestamp: add key to disambiguate concurrent datagrams 2014-08-05T23:35:54+00:00 Willem de Bruijn willemb@google.com 2014-08-05T02:11:47+00:00 09c2d251b70723650ba47e83571ff49281320f7c Datagrams timestamped on transmission can coexist in the kernel stack and be reordered in packet scheduling. When reading looped datagrams from the socket error queue it is not always possible to unique correlate looped data with original send() call (for application level retransmits). Even if possible, it may be expensive and complex, requiring packet inspection. Introduce a data-independent ID mechanism to associate timestamps with send calls. Pass an ID alongside the timestamp in field ee_data of sock_extended_err. The ID is a simple 32 bit unsigned int that is associated with the socket and incremented on each send() call for which software tx timestamp generation is enabled. The feature is enabled only if SOF_TIMESTAMPING_OPT_ID is set, to avoid changing ee_data for existing applications that expect it 0. The counter is reset each time the flag is reenabled. Reenabling does not change the ID of already submitted data. It is possible to receive out of order IDs if the timestamp stream is not quiesced first. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Datagrams timestamped on transmission can coexist in the kernel stack
and be reordered in packet scheduling. When reading looped datagrams
from the socket error queue it is not always possible to unique
correlate looped data with original send() call (for application
level retransmits). Even if possible, it may be expensive and complex,
requiring packet inspection.

Introduce a data-independent ID mechanism to associate timestamps with
send calls. Pass an ID alongside the timestamp in field ee_data of
sock_extended_err.

The ID is a simple 32 bit unsigned int that is associated with the
socket and incremented on each send() call for which software tx
timestamp generation is enabled.

The feature is enabled only if SOF_TIMESTAMPING_OPT_ID is set, to
avoid changing ee_data for existing applications that expect it 0.
The counter is reset each time the flag is reenabled. Reenabling
does not change the ID of already submitted data. It is possible
to receive out of order IDs if the timestamp stream is not quiesced
first.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net-timestamp: extend SCM_TIMESTAMPING ancillary data struct 2014-08-05T23:35:53+00:00 Willem de Bruijn willemb@google.com 2014-08-05T02:11:45+00:00 f24b9be5957b38bb420b838115040dc2031b7d0c Applications that request kernel tx timestamps with SO_TIMESTAMPING read timestamps as recvmsg() ancillary data. The response is defined implicitly as timespec[3]. 1) define struct scm_timestamping explicitly and 2) add support for new tstamp types. On tx, scm_timestamping always accompanies a sock_extended_err. Define previously unused field ee_info to signal the type of ts[0]. Introduce SCM_TSTAMP_SND to define the existing behavior. The reception path is not modified. On rx, no struct similar to sock_extended_err is passed along with SCM_TIMESTAMPING. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Applications that request kernel tx timestamps with SO_TIMESTAMPING
read timestamps as recvmsg() ancillary data. The response is defined
implicitly as timespec[3].

1) define struct scm_timestamping explicitly and

2) add support for new tstamp types. On tx, scm_timestamping always
   accompanies a sock_extended_err. Define previously unused field
   ee_info to signal the type of ts[0]. Introduce SCM_TSTAMP_SND to
   define the existing behavior.

The reception path is not modified. On rx, no struct similar to
sock_extended_err is passed along with SCM_TIMESTAMPING.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: Correctly set segment mac_len in skb_segment(). 2014-08-01T05:28:39+00:00 Vlad Yasevich vyasevic@redhat.com 2014-07-31T14:33:06+00:00 fcdfe3a7fa4cb74391d42b6a26dc07c20dab1d82 When performing segmentation, the mac_len value is copied right out of the original skb. However, this value is not always set correctly (like when the packet is VLAN-tagged) and we'll end up copying a bad value. One way to demonstrate this is to configure a VM which tags packets internally and turn off VLAN acceleration on the forwarding bridge port. The packets show up corrupt like this: 16:18:24.985548 52:54:00:ab:be:25 > 52:54:00:26:ce:a3, ethertype 802.1Q (0x8100), length 1518: vlan 100, p 0, ethertype 0x05e0, 0x0000: 8cdb 1c7c 8cdb 0064 4006 b59d 0a00 6402 ...|...d@.....d. 0x0010: 0a00 6401 9e0d b441 0a5e 64ec 0330 14fa ..d....A.^d..0.. 0x0020: 29e3 01c9 f871 0000 0101 080a 000a e833)....q.........3 0x0030: 000f 8c75 6e65 7470 6572 6600 6e65 7470 ...unetperf.netp 0x0040: 6572 6600 6e65 7470 6572 6600 6e65 7470 erf.netperf.netp 0x0050: 6572 6600 6e65 7470 6572 6600 6e65 7470 erf.netperf.netp 0x0060: 6572 6600 6e65 7470 6572 6600 6e65 7470 erf.netperf.netp ... This also leads to awful throughput as GSO packets are dropped and cause retransmissions. The solution is to set the mac_len using the values already available in then new skb. We've already adjusted all of the header offset, so we might as well correctly figure out the mac_len using skb_reset_mac_len(). After this change, packets are segmented correctly and performance is restored. CC: Eric Dumazet <edumazet@google.com> Signed-off-by: Vlad Yasevich <vyasevic@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
When performing segmentation, the mac_len value is copied right
out of the original skb.  However, this value is not always set correctly
(like when the packet is VLAN-tagged) and we'll end up copying a bad
value.

One way to demonstrate this is to configure a VM which tags
packets internally and turn off VLAN acceleration on the forwarding
bridge port.  The packets show up corrupt like this:
16:18:24.985548 52:54:00:ab:be:25 > 52:54:00:26:ce:a3, ethertype 802.1Q
(0x8100), length 1518: vlan 100, p 0, ethertype 0x05e0,
        0x0000:  8cdb 1c7c 8cdb 0064 4006 b59d 0a00 6402 ...|...d@.....d.
        0x0010:  0a00 6401 9e0d b441 0a5e 64ec 0330 14fa ..d....A.^d..0..
        0x0020:  29e3 01c9 f871 0000 0101 080a 000a e833)....q.........3
        0x0030:  000f 8c75 6e65 7470 6572 6600 6e65 7470 ...unetperf.netp
        0x0040:  6572 6600 6e65 7470 6572 6600 6e65 7470 erf.netperf.netp
        0x0050:  6572 6600 6e65 7470 6572 6600 6e65 7470 erf.netperf.netp
        0x0060:  6572 6600 6e65 7470 6572 6600 6e65 7470 erf.netperf.netp
        ...

This also leads to awful throughput as GSO packets are dropped and
cause retransmissions.

The solution is to set the mac_len using the values already available
in then new skb.  We've already adjusted all of the header offset, so we
might as well correctly figure out the mac_len using skb_reset_mac_len().
After this change, packets are segmented correctly and performance
is restored.

CC: Eric Dumazet <edumazet@google.com>
Signed-off-by: Vlad Yasevich <vyasevic@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: fix setting csum_start in skb_segment() 2014-06-26T03:45:54+00:00 Tom Herbert therbert@google.com 2014-06-25T19:51:01+00:00 de843723f9b989178762196fb24dd050cbe20ca3 Dave Jones reported that a crash is occurring in csum_partial tcp_gso_segment inet_gso_segment ? update_dl_migration skb_mac_gso_segment __skb_gso_segment dev_hard_start_xmit sch_direct_xmit __dev_queue_xmit ? dev_hard_start_xmit dev_queue_xmit ip_finish_output ? ip_output ip_output ip_forward_finish ip_forward ip_rcv_finish ip_rcv __netif_receive_skb_core ? __netif_receive_skb_core ? trace_hardirqs_on __netif_receive_skb netif_receive_skb_internal napi_gro_complete ? napi_gro_complete dev_gro_receive ? dev_gro_receive napi_gro_receive It looks like a likely culprit is that SKB_GSO_CB()->csum_start is not set correctly when doing non-scatter gather. We are using offset as opposed to doffset. Reported-by: Dave Jones <davej@redhat.com> Tested-by: Dave Jones <davej@redhat.com> Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Fixes: 7e2b10c1e52ca ("net: Support for multiple checksums with gso") Acked-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Dave Jones reported that a crash is occurring in

csum_partial
tcp_gso_segment
inet_gso_segment
? update_dl_migration
skb_mac_gso_segment
__skb_gso_segment
dev_hard_start_xmit
sch_direct_xmit
__dev_queue_xmit
? dev_hard_start_xmit
dev_queue_xmit
ip_finish_output
? ip_output
ip_output
ip_forward_finish
ip_forward
ip_rcv_finish
ip_rcv
__netif_receive_skb_core
? __netif_receive_skb_core
? trace_hardirqs_on
__netif_receive_skb
netif_receive_skb_internal
napi_gro_complete
? napi_gro_complete
dev_gro_receive
? dev_gro_receive
napi_gro_receive

It looks like a likely culprit is that SKB_GSO_CB()->csum_start is
not set correctly when doing non-scatter gather. We are using
offset as opposed to doffset.

Reported-by: Dave Jones <davej@redhat.com>
Tested-by: Dave Jones <davej@redhat.com>
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: 7e2b10c1e52ca ("net: Support for multiple checksums with gso")
Acked-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>