linux.git/net/ipv6/raw.c, branch v2.6.22

[XFRM]: Allow packet drops during larval state resolution.

2007-05-25T01:17:54+00:00

The current IPSEC rule resolution behavior we have does not work for a
lot of people, even though technically it's an improvement from the
-EAGAIN buisness we had before.

Right now we'll block until the key manager resolves the route.  That
works for simple cases, but many folks would rather packets get
silently dropped until the key manager resolves the IPSEC rules.

We can't tell these folks to "set the socket non-blocking" because
they don't have control over the non-block setting of things like the
sockets used to resolve DNS deep inside of the resolver libraries in
libc.

With that in mind I coded up the patch below with some help from
Herbert Xu which provides packet-drop behavior during larval state
resolution, controllable via sysctl and off by default.

This lays the framework to either:

1) Make this default at some point or...

2) Move this logic into xfrm{4,6}_policy.c and implement the
   ARP-like resolution queue we've all been dreaming of.
   The idea would be to queue packets to the policy, then
   once the larval state is resolved by the key manager we
   re-resolve the route and push the packets out.  The
   packets would timeout if the rule didn't get resolved
   in a certain amount of time.

Signed-off-by: David S. Miller

[NET]: cleanup extra semicolons

2007-04-26T05:29:24+00:00

Spring cleaning time...

There seems to be a lot of places in the network code that have
extra bogus semicolons after conditionals.  Most commonly is a
bogus semicolon after: switch() { }

Signed-off-by: Stephen Hemminger 
Signed-off-by: David S. Miller

[NET]: Treat CHECKSUM_PARTIAL as CHECKSUM_UNNECESSARY

2007-04-26T05:28:43+00:00

When a transmitted packet is looped back directly, CHECKSUM_PARTIAL
maps to the semantics of CHECKSUM_UNNECESSARY.  Therefore we should
treat it as such in the stack.

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

[SK_BUFF]: Convert skb->tail to sk_buff_data_t

2007-04-26T05:26:28+00:00

So that it is also an offset from skb->head, reduces its size from 8 to 4 bytes
on 64bit architectures, allowing us to combine the 4 bytes hole left by the
layer headers conversion, reducing struct sk_buff size to 256 bytes, i.e. 4
64byte cachelines, and since the sk_buff slab cache is SLAB_HWCACHE_ALIGN...
:-)

Many calculations that previously required that skb->{transport,network,
mac}_header be first converted to a pointer now can be done directly, being
meaningful as offsets or pointers.

Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: David S. Miller

[SK_BUFF]: unions of just one member don't get anything done, kill them

2007-04-26T05:26:20+00:00

Renaming skb->h to skb->transport_header, skb->nh to skb->network_header and
skb->mac to skb->mac_header, to match the names of the associated helpers
(skb[_[re]set]_{transport,network,mac}_header).

Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: David S. Miller

[SK_BUFF]: Introduce skb_network_header_len

2007-04-26T05:26:19+00:00

For the common sequence "skb->h.raw - skb->nh.raw", similar to skb->mac_len,
that is precalculated tho, don't think we need to bloat skb with one more
member, so just use this new helper, reducing the number of non-skbuff.h
references to the layer headers even more.

Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: David S. Miller

[SK_BUFF]: Introduce skb_transport_header(skb)

2007-04-26T05:25:31+00:00

For the places where we need a pointer to the transport header, it is
still legal to touch skb->h.raw directly if just adding to,
subtracting from or setting it to another layer header.

Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: David S. Miller

[SK_BUFF]: Introduce skb_transport_offset()

2007-04-26T05:25:16+00:00

For the quite common 'skb->h.raw - skb->data' sequence.

Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: David S. Miller

[SK_BUFF]: Introduce ipv6_hdr(), remove skb->nh.ipv6h

2007-04-26T05:25:14+00:00

Now the skb->nh union has just one member, .raw, i.e. it is just like the
skb->mac union, strange, no? I'm just leaving it like that till the transport
layer is done with, when we'll rename skb->mac.raw to skb->mac_header (or
->mac_header_offset?), ditto for ->{h,nh}.

Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: David S. Miller

[SK_BUFF]: Introduce skb_network_header()

2007-04-26T05:24:59+00:00

For the places where we need a pointer to the network header, it is still legal
to touch skb->nh.raw directly if just adding to, subtracting from or setting it
to another layer header.

Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: David S. Miller