linux-toradex.git/net/ipv4/ip_output.c, branch v2.6.18

[IPV4]: Fix SNMPv2 "ipFragFails" counter error

2006-08-31T22:24:48+00:00

  When I tested Linux kernel 2.6.17.7 about statistics
"ipFragFails",found that this counter couldn't increase correctly. The
criteria is RFC2011:
RFC2011
  ipFragFails OBJECT-TYPE
    SYNTAX      Counter32
    MAX-ACCESS  read-only
    STATUS      current
    DESCRIPTION
            "The number of IP datagrams that have been discarded because
            they needed to be fragmented at this entity but could not
            be, e.g., because their Don't Fragment flag was set."
    ::= { ip 18 }

When I send big IP packet to a router with DF bit set to 1 which need to
be fragmented, and router just sends an ICMP error message
ICMP_FRAG_NEEDED but no increments for this counter(in the function
ip_fragment).

Signed-off-by: Wei Dong 
Signed-off-by: David S. Miller

[INET]: Use pskb_trim_unique when trimming paged unique skbs

2006-08-14T03:12:58+00:00

The IPv4/IPv6 datagram output path was using skb_trim to trim paged
packets because they know that the packet has not been cloned yet
(since the packet hasn't been given to anything else in the system).

This broke because skb_trim no longer allows paged packets to be
trimmed.  Paged packets must be given to one of the pskb_trim functions
instead.

This patch adds a new pskb_trim_unique function to cover the IPv4/IPv6
datagram output path scenario and replaces the corresponding skb_trim
calls with it.

Signed-off-by: Herbert Xu 
Signed-off-by: David S. Miller

[IPV6]: SNMPv2 "ipv6IfStatsOutFragCreates" counter error

2006-08-02T20:41:21+00:00

  When I tested linux kernel 2.6.71.7 about statistics
"ipv6IfStatsOutFragCreates", and found that it couldn't increase
correctly. The criteria is RFC 2465:

  ipv6IfStatsOutFragCreates OBJECT-TYPE
      SYNTAX      Counter32
      MAX-ACCESS  read-only
      STATUS      current
      DESCRIPTION
         "The number of output datagram fragments that have
         been generated as a result of fragmentation at
         this output interface."
      ::= { ipv6IfStatsEntry 15 }

I think there are two issues in Linux kernel. 
1st:
RFC2465 specifies the counter is "The number of output datagram
fragments...". I think increasing this counter after output a fragment
successfully is better. And it should not be increased even though a
fragment is created but failed to output.

2nd:
If we send a big ICMP/ICMPv6 echo request to a host, and receive
ICMP/ICMPv6 echo reply consisted of some fragments. As we know that in
Linux kernel first fragmentation occurs in ICMP layer(maybe saying
transport layer is better), but this is not the "real"
fragmentation,just do some "pre-fragment" -- allocate space for date,
and form a frag_list, etc. The "real" fragmentation happens in IP layer
-- set offset and MF flag and so on. So I think in "fast path" for
ip_fragment/ip6_fragment, if we send a fragment which "pre-fragment" by
upper layer we should also increase "ipv6IfStatsOutFragCreates".

Signed-off-by: Wei Dong 
Acked-by: YOSHIFUJI Hideaki 
Signed-off-by: David S. Miller

[NET] gso: Add skb_is_gso

2006-07-08T20:34:32+00:00

This patch adds the wrapper function skb_is_gso which can be used instead
of directly testing skb_shinfo(skb)->gso_size.  This makes things a little
nicer and allows us to change the primary key for indicating whether an skb
is GSO (if we ever want to do that).

Signed-off-by: Herbert Xu 
Signed-off-by: David S. Miller

Merge master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6

2006-06-30T22:40:17+00:00

* master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6:
  [IPV6]: Added GSO support for TCPv6
  [NET]: Generalise TSO-specific bits from skb_setup_caps
  [IPV6]: Added GSO support for TCPv6
  [IPV6]: Remove redundant length check on input
  [NETFILTER]: SCTP conntrack: fix crash triggered by packet without chunks
  [TG3]: Update version and reldate
  [TG3]: Add TSO workaround using GSO
  [TG3]: Turn on hw fix for ASF problems
  [TG3]: Add rx BD workaround
  [TG3]: Add tg3_netif_stop() in vlan functions
  [TCP]: Reset gso_segs if packet is dodgy

[IPV6]: Added GSO support for TCPv6

2006-06-30T21:12:10+00:00

This patch adds GSO support for IPv6 and TCPv6.  This is based on a patch
by Ananda Raju .  His original description is:

	This patch enables TSO over IPv6. Currently Linux network stacks
	restricts TSO over IPv6 by clearing of the NETIF_F_TSO bit from
	"dev->features". This patch will remove this restriction.

	This patch will introduce a new flag NETIF_F_TSO6 which will be used
	to check whether device supports TSO over IPv6. If device support TSO
	over IPv6 then we don't clear of NETIF_F_TSO and which will make the
	TCP layer to create TSO packets. Any device supporting TSO over IPv6
	will set NETIF_F_TSO6 flag in "dev->features" along with NETIF_F_TSO.

	In case when user disables TSO using ethtool, NETIF_F_TSO will get
	cleared from "dev->features". So even if we have NETIF_F_TSO6 we don't
	get TSO packets created by TCP layer.

	SKB_GSO_TCPV4 renamed to SKB_GSO_TCP to make it generic GSO packet.
	SKB_GSO_UDPV4 renamed to SKB_GSO_UDP as UFO is not a IPv4 feature.
	UFO is supported over IPv6 also

	The following table shows there is significant improvement in
	throughput with normal frames and CPU usage for both normal and jumbo.

	--------------------------------------------------
	|          |     1500        |      9600         |
	|          ------------------|-------------------|
	|          | thru     CPU    |  thru     CPU     |
	--------------------------------------------------
	| TSO OFF  | 2.00   5.5% id  |  5.66   20.0% id  |
	--------------------------------------------------
	| TSO ON   | 2.63   78.0 id  |  5.67   39.0% id  |
	--------------------------------------------------

Signed-off-by: Herbert Xu 
Signed-off-by: David S. Miller

Remove obsolete #include

2006-06-30T17:25:36+00:00

Signed-off-by: Jörn Engel 
Signed-off-by: Adrian Bunk

[NET]: Merge TSO/UFO fields in sk_buff

2006-06-23T09:07:29+00:00

Having separate fields in sk_buff for TSO/UFO (tso_size/ufo_size) is not
going to scale if we add any more segmentation methods (e.g., DCCP).  So
let's merge them.

They were used to tell the protocol of a packet.  This function has been
subsumed by the new gso_type field.  This is essentially a set of netdev
feature bits (shifted by 16 bits) that are required to process a specific
skb.  As such it's easy to tell whether a given device can process a GSO
skb: you just have to and the gso_type field and the netdev's features
field.

I've made gso_type a conjunction.  The idea is that you have a base type
(e.g., SKB_GSO_TCPV4) that can be modified further to support new features.
For example, if we add a hardware TSO type that supports ECN, they would
declare NETIF_F_TSO | NETIF_F_TSO_ECN.  All TSO packets with CWR set would
have a gso_type of SKB_GSO_TCPV4 | SKB_GSO_TCPV4_ECN while all other TSO
packets would be SKB_GSO_TCPV4.  This means that only the CWR packets need
to be emulated in software.

Signed-off-by: Herbert Xu 
Signed-off-by: David S. Miller

[NET]: Add NETIF_F_GEN_CSUM and NETIF_F_ALL_CSUM

2006-06-18T05:06:05+00:00

The current stack treats NETIF_F_HW_CSUM and NETIF_F_NO_CSUM
identically so we test for them in quite a few places.  For the sake
of brevity, I'm adding the macro NETIF_F_GEN_CSUM for these two.  We
also test the disjunct of NETIF_F_IP_CSUM and the other two in various
places, for that purpose I've added NETIF_F_ALL_CSUM.

Signed-off-by: Herbert Xu 
Signed-off-by: David S. Miller

[SECMARK]: Add secmark support to core networking.

2006-06-18T04:29:57+00:00

Add a secmark field to the skbuff structure, to allow security subsystems to
place security markings on network packets.  This is similar to the nfmark
field, except is intended for implementing security policy, rather than than
networking policy.

This patch was already acked in principle by Dave Miller.

Signed-off-by: James Morris 
Signed-off-by: Andrew Morton 
Signed-off-by: David S. Miller