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<title>lwn.git/net/ipv4/route.c, branch v2.6.32.14</title>
<subtitle>Linux kernel documentation tree maintained by Jonathan Corbet</subtitle>
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<updated>2009-10-30T05:49:12+00:00</updated>
<entry>
<title>net: Fix RPF to work with policy routing</title>
<updated>2009-10-30T05:49:12+00:00</updated>
<author>
<name>jamal</name>
<email>hadi@cyberus.ca</email>
</author>
<published>2009-10-18T02:12:33+00:00</published>
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<id>urn:sha1:b0c110ca8e89f2c9cd52ec7fb1b98c5b7aa78496</id>
<content type='text'>
Policy routing is not looked up by mark on reverse path filtering.
This fixes it.

Signed-off-by: Jamal Hadi Salim &lt;hadi@cyberus.ca&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>sysctl: remove "struct file *" argument of -&gt;proc_handler</title>
<updated>2009-09-24T14:21:04+00:00</updated>
<author>
<name>Alexey Dobriyan</name>
<email>adobriyan@gmail.com</email>
</author>
<published>2009-09-23T22:57:19+00:00</published>
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<id>urn:sha1:8d65af789f3e2cf4cfbdbf71a0f7a61ebcd41d38</id>
<content type='text'>
It's unused.

It isn't needed -- read or write flag is already passed and sysctl
shouldn't care about the rest.

It _was_ used in two places at arch/frv for some reason.

Signed-off-by: Alexey Dobriyan &lt;adobriyan@gmail.com&gt;
Cc: David Howells &lt;dhowells@redhat.com&gt;
Cc: "Eric W. Biederman" &lt;ebiederm@xmission.com&gt;
Cc: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: Martin Schwidefsky &lt;schwidefsky@de.ibm.com&gt;
Cc: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Cc: James Morris &lt;jmorris@namei.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>mm: replace various uses of num_physpages by totalram_pages</title>
<updated>2009-09-22T14:17:38+00:00</updated>
<author>
<name>Jan Beulich</name>
<email>JBeulich@novell.com</email>
</author>
<published>2009-09-22T00:03:05+00:00</published>
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<id>urn:sha1:4481374ce88ba8f460c8b89f2572027bd27057d0</id>
<content type='text'>
Sizing of memory allocations shouldn't depend on the number of physical
pages found in a system, as that generally includes (perhaps a huge amount
of) non-RAM pages.  The amount of what actually is usable as storage
should instead be used as a basis here.

Some of the calculations (i.e.  those not intending to use high memory)
should likely even use (totalram_pages - totalhigh_pages).

Signed-off-by: Jan Beulich &lt;jbeulich@novell.com&gt;
Acked-by: Rusty Russell &lt;rusty@rustcorp.com.au&gt;
Acked-by: Ingo Molnar &lt;mingo@elte.hu&gt;
Cc: Dave Airlie &lt;airlied@linux.ie&gt;
Cc: Kyle McMartin &lt;kyle@mcmartin.ca&gt;
Cc: Jeremy Fitzhardinge &lt;jeremy@goop.org&gt;
Cc: Pekka Enberg &lt;penberg@cs.helsinki.fi&gt;
Cc: Hugh Dickins &lt;hugh.dickins@tiscali.co.uk&gt;
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Cc: Patrick McHardy &lt;kaber@trash.net&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>net: ip_rt_send_redirect() optimization</title>
<updated>2009-08-29T06:52:01+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>eric.dumazet@gmail.com</email>
</author>
<published>2009-08-29T06:52:01+00:00</published>
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<id>urn:sha1:30038fc61adfdab162b1966e34261f06eda67f02</id>
<content type='text'>
While doing some forwarding benchmarks, I noticed
ip_rt_send_redirect() is rather expensive, even if send_redirects is
false for the device.

Fix is to avoid two atomic ops, we dont really need to take a
reference on in_dev

Signed-off-by: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>xfrm: select sane defaults for xfrm[4|6] gc_thresh</title>
<updated>2009-07-31T01:52:15+00:00</updated>
<author>
<name>Neil Horman</name>
<email>nhorman@tuxdriver.com</email>
</author>
<published>2009-07-31T01:52:15+00:00</published>
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<id>urn:sha1:a33bc5c15154c835aae26f16e6a3a7d9ad4acb45</id>
<content type='text'>
Choose saner defaults for xfrm[4|6] gc_thresh values on init

Currently, the xfrm[4|6] code has hard-coded initial gc_thresh values
(set to 1024).  Given that the ipv4 and ipv6 routing caches are sized
dynamically at boot time, the static selections can be non-sensical.
This patch dynamically selects an appropriate gc threshold based on
the corresponding main routing table size, using the assumption that
we should in the worst case be able to handle as many connections as
the routing table can.

For ipv4, the maximum route cache size is 16 * the number of hash
buckets in the route cache.  Given that xfrm4 starts garbage
collection at the gc_thresh and prevents new allocations at 2 *
gc_thresh, we set gc_thresh to half the maximum route cache size.

For ipv6, its a bit trickier.  there is no maximum route cache size,
but the ipv6 dst_ops gc_thresh is statically set to 1024.  It seems
sane to select a simmilar gc_thresh for the xfrm6 code that is half
the number of hash buckets in the v6 route cache times 16 (like the v4
code does).

Signed-off-by: Neil Horman &lt;nhorman@tuxdriver.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>ipv4 routing: Ensure that route cache entries are usable and reclaimable with caching is off</title>
<updated>2009-06-23T23:36:26+00:00</updated>
<author>
<name>Neil Horman</name>
<email>nhorman@tuxdriver.com</email>
</author>
<published>2009-06-22T10:18:53+00:00</published>
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<id>urn:sha1:b6280b47a7a42970d098a3059f4ebe7e55e90d8d</id>
<content type='text'>
When route caching is disabled (rt_caching returns false), We still use route
cache entries that are created and passed into rt_intern_hash once.  These
routes need to be made usable for the one call path that holds a reference to
them, and they need to be reclaimed when they're finished with their use.  To be
made usable, they need to be associated with a neighbor table entry (which they
currently are not), otherwise iproute_finish2 just discards the packet, since we
don't know which L2 peer to send the packet to.  To do this binding, we need to
follow the path a bit higher up in rt_intern_hash, which calls
arp_bind_neighbour, but not assign the route entry to the hash table.
Currently, if caching is off, we simply assign the route to the rp pointer and
are reutrn success.  This patch associates us with a neighbor entry first.

Secondly, we need to make sure that any single use routes like this are known to
the garbage collector when caching is off.  If caching is off, and we try to
hash in a route, it will leak when its refcount reaches zero.  To avoid this,
this patch calls rt_free on the route cache entry passed into rt_intern_hash.
This places us on the gc list for the route cache garbage collector, so that
when its refcount reaches zero, it will be reclaimed (Thanks to Alexey for this
suggestion).

I've tested this on a local system here, and with these patches in place, I'm
able to maintain routed connectivity to remote systems, even if I set
/proc/sys/net/ipv4/rt_cache_rebuild_count to -1, which forces rt_caching to
return false.

Signed-off-by: Neil Horman &lt;nhorman@redhat.com&gt;
Reported-by: Jarek Poplawski &lt;jarkao2@gmail.com&gt;
Reported-by: Maxime Bizon &lt;mbizon@freebox.fr&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>ipv4: fix NULL pointer + success return in route lookup path</title>
<updated>2009-06-20T08:15:16+00:00</updated>
<author>
<name>Neil Horman</name>
<email>nhorman@tuxdriver.com</email>
</author>
<published>2009-06-20T08:15:16+00:00</published>
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<id>urn:sha1:73e42897e8e5619eacb787d2ce69be12f47cfc21</id>
<content type='text'>
Don't drop route if we're not caching	

	I recently got a report of an oops on a route lookup.  Maxime was
testing what would happen if route caching was turned off (doing so by setting
making rt_caching always return 0), and found that it triggered an oops.  I
looked at it and found that the problem stemmed from the fact that the route
lookup routines were returning success from their lookup paths (which is good),
but never set the **rp pointer to anything (which is bad).  This happens because
in rt_intern_hash, if rt_caching returns false, we call rt_drop and return 0.
This almost emulates slient success.  What we should be doing is assigning *rp =
rt and _not_ dropping the route.  This way, during slow path lookups, when we
create a new route cache entry, we don't immediately discard it, rather we just
don't add it into the cache hash table, but we let this one lookup use it for
the purpose of this route request.  Maxime has tested and reports it prevents
the oops.  There is still a subsequent routing issue that I'm looking into
further, but I'm confident that, even if its related to this same path, this
patch makes sense to take.

Signed-off-by: Neil Horman &lt;nhorman@tuxdriver.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>net: use a deferred timer in rt_check_expire</title>
<updated>2009-06-14T06:36:31+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>eric.dumazet@gmail.com</email>
</author>
<published>2009-06-11T20:10:07+00:00</published>
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<id>urn:sha1:125bb8f5637bd653244728f734bcac218986d910</id>
<content type='text'>
For the sake of power saver lovers, use a deferrable timer to fire
rt_check_expire()

As some big routers cache equilibrium depends on garbage collection
done in time, we take into account elapsed time between two
rt_check_expire() invocations to adjust the amount of slots we have to
check.

Based on an initial idea and patch from Tero Kristo

Signed-off-by: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Signed-off-by: Tero Kristo &lt;tero.kristo@nokia.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>net: skb-&gt;dst accessors</title>
<updated>2009-06-03T09:51:04+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>eric.dumazet@gmail.com</email>
</author>
<published>2009-06-02T05:19:30+00:00</published>
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<id>urn:sha1:adf30907d63893e4208dfe3f5c88ae12bc2f25d5</id>
<content type='text'>
Define three accessors to get/set dst attached to a skb

struct dst_entry *skb_dst(const struct sk_buff *skb)

void skb_dst_set(struct sk_buff *skb, struct dst_entry *dst)

void skb_dst_drop(struct sk_buff *skb)
This one should replace occurrences of :
dst_release(skb-&gt;dst)
skb-&gt;dst = NULL;

Delete skb-&gt;dst field

Signed-off-by: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
<entry>
<title>net: skb-&gt;rtable accessor</title>
<updated>2009-06-03T09:51:02+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>eric.dumazet@gmail.com</email>
</author>
<published>2009-06-02T05:14:27+00:00</published>
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<id>urn:sha1:511c3f92ad5b6d9f8f6464be1b4f85f0422be91a</id>
<content type='text'>
Define skb_rtable(const struct sk_buff *skb) accessor to get rtable from skb

Delete skb-&gt;rtable field

Setting rtable is not allowed, just set dst instead as rtable is an alias.

Signed-off-by: Eric Dumazet &lt;eric.dumazet@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
</entry>
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