1
Commit Graph

318 Commits

Author SHA1 Message Date
David S. Miller
9a1b9496cd ipv4: Pass explicit saddr/daddr args to ipmr_get_route().
This eliminates the need to use rt->rt_{src,dst}.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-04 12:18:54 -07:00
David S. Miller
475949d8e8 ipv4: Renamt struct rtable's rt_tos to rt_key_tos.
To more accurately reflect that it is purely a routing
cache lookup key and is used in no other context.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-03 19:45:15 -07:00
David S. Miller
5615787257 ipv4: Make sure flowi4->{saddr,daddr} are always set.
Slow path output route resolution always makes sure that
->{saddr,daddr} are set, and also if we trigger into IPSEC resolution
we initialize them as well, because xfrm_lookup() expects them to be
fully resolved.

But if we hit the fast path and flowi4->flowi4_proto is zero, we won't
do this initialization.

Therefore, move the IPSEC path initialization to the route cache
lookup fast path to make sure these are always set.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-02 14:37:45 -07:00
David S. Miller
813b3b5db8 ipv4: Use caller's on-stack flowi as-is in output route lookups.
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-28 22:26:00 -07:00
David S. Miller
cf91166223 net: Use non-zero allocations in dst_alloc().
Make dst_alloc() and it's users explicitly initialize the entire
entry.

The zero'ing done by kmem_cache_zalloc() was almost entirely
redundant.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-28 22:26:00 -07:00
David S. Miller
5c1e6aa300 net: Make dst_alloc() take more explicit initializations.
Now the dst->dev, dev->obsolete, and dst->flags values can
be specified as well.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-28 22:25:59 -07:00
David S. Miller
2bd93d7af1 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Resolved logic conflicts causing a build failure due to
drivers/net/r8169.c changes using a patch from Stephen Rothwell.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-26 12:16:46 -07:00
Held Bernhard
0972ddb237 net: provide cow_metrics() methods to blackhole dst_ops
Since commit 62fa8a846d (net: Implement read-only protection and COW'ing
of metrics.) the kernel throws an oops.

[  101.620985] BUG: unable to handle kernel NULL pointer dereference at
           (null)
[  101.621050] IP: [<          (null)>]           (null)
[  101.621084] PGD 6e53c067 PUD 3dd6a067 PMD 0
[  101.621122] Oops: 0010 [#1] SMP
[  101.621153] last sysfs file: /sys/devices/virtual/ppp/ppp/uevent
[  101.621192] CPU 2
[  101.621206] Modules linked in: l2tp_ppp pppox ppp_generic slhc
l2tp_netlink l2tp_core deflate zlib_deflate twofish_x86_64
twofish_common des_generic cbc ecb sha1_generic hmac af_key
iptable_filter snd_pcm_oss snd_mixer_oss snd_seq snd_seq_device loop
snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_intel snd_hda_codec
snd_pcm snd_timer snd i2c_i801 iTCO_wdt psmouse soundcore snd_page_alloc
evdev uhci_hcd ehci_hcd thermal
[  101.621552]
[  101.621567] Pid: 5129, comm: openl2tpd Not tainted 2.6.39-rc4-Quad #3
Gigabyte Technology Co., Ltd. G33-DS3R/G33-DS3R
[  101.621637] RIP: 0010:[<0000000000000000>]  [<          (null)>]   (null)
[  101.621684] RSP: 0018:ffff88003ddeba60  EFLAGS: 00010202
[  101.621716] RAX: ffff88003ddb5600 RBX: ffff88003ddb5600 RCX:
0000000000000020
[  101.621758] RDX: ffffffff81a69a00 RSI: ffffffff81b7ee61 RDI:
ffff88003ddb5600
[  101.621800] RBP: ffff8800537cd900 R08: 0000000000000000 R09:
ffff88003ddb5600
[  101.621840] R10: 0000000000000005 R11: 0000000000014b38 R12:
ffff88003ddb5600
[  101.621881] R13: ffffffff81b7e480 R14: ffffffff81b7e8b8 R15:
ffff88003ddebad8
[  101.621924] FS:  00007f06e4182700(0000) GS:ffff88007fd00000(0000)
knlGS:0000000000000000
[  101.621971] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  101.622005] CR2: 0000000000000000 CR3: 0000000045274000 CR4:
00000000000006e0
[  101.622046] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[  101.622087] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7:
0000000000000400
[  101.622129] Process openl2tpd (pid: 5129, threadinfo
ffff88003ddea000, task ffff88003de9a280)
[  101.622177] Stack:
[  101.622191]  ffffffff81447efa ffff88007d3ded80 ffff88003de9a280
ffff88007d3ded80
[  101.622245]  0000000000000001 ffff88003ddebbb8 ffffffff8148d5a7
0000000000000212
[  101.622299]  ffff88003dcea000 ffff88003dcea188 ffffffff00000001
ffffffff81b7e480
[  101.622353] Call Trace:
[  101.622374]  [<ffffffff81447efa>] ? ipv4_blackhole_route+0x1ba/0x210
[  101.622415]  [<ffffffff8148d5a7>] ? xfrm_lookup+0x417/0x510
[  101.622450]  [<ffffffff8127672a>] ? extract_buf+0x9a/0x140
[  101.622485]  [<ffffffff8144c6a0>] ? __ip_flush_pending_frames+0x70/0x70
[  101.622526]  [<ffffffff8146fbbf>] ? udp_sendmsg+0x62f/0x810
[  101.622562]  [<ffffffff813f98a6>] ? sock_sendmsg+0x116/0x130
[  101.622599]  [<ffffffff8109df58>] ? find_get_page+0x18/0x90
[  101.622633]  [<ffffffff8109fd6a>] ? filemap_fault+0x12a/0x4b0
[  101.622668]  [<ffffffff813fb5c4>] ? move_addr_to_kernel+0x64/0x90
[  101.622706]  [<ffffffff81405d5a>] ? verify_iovec+0x7a/0xf0
[  101.622739]  [<ffffffff813fc772>] ? sys_sendmsg+0x292/0x420
[  101.622774]  [<ffffffff810b994a>] ? handle_pte_fault+0x8a/0x7c0
[  101.622810]  [<ffffffff810b76fe>] ? __pte_alloc+0xae/0x130
[  101.622844]  [<ffffffff810ba2f8>] ? handle_mm_fault+0x138/0x380
[  101.622880]  [<ffffffff81024af9>] ? do_page_fault+0x189/0x410
[  101.622915]  [<ffffffff813fbe03>] ? sys_getsockname+0xf3/0x110
[  101.622952]  [<ffffffff81450c4d>] ? ip_setsockopt+0x4d/0xa0
[  101.622986]  [<ffffffff813f9932>] ? sockfd_lookup_light+0x22/0x90
[  101.623024]  [<ffffffff814b61fb>] ? system_call_fastpath+0x16/0x1b
[  101.623060] Code:  Bad RIP value.
[  101.623090] RIP  [<          (null)>]           (null)
[  101.623125]  RSP <ffff88003ddeba60>
[  101.623146] CR2: 0000000000000000
[  101.650871] ---[ end trace ca3856a7d8e8dad4 ]---
[  101.651011] __sk_free: optmem leakage (160 bytes) detected.

The oops happens in dst_metrics_write_ptr()
include/net/dst.h:124: return dst->ops->cow_metrics(dst, p);

dst->ops->cow_metrics is NULL and causes the oops.

Provide cow_metrics() methods, like we did in commit 214f45c91b
(net: provide default_advmss() methods to blackhole dst_ops)

Signed-off-by: Held Bernhard <berny156@gmx.de>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-25 11:53:08 -07:00
Eric Dumazet
b71d1d426d inet: constify ip headers and in6_addr
Add const qualifiers to structs iphdr, ipv6hdr and in6_addr pointers
where possible, to make code intention more obvious.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-22 11:04:14 -07:00
David S. Miller
21d8c49e01 ipv4: Call fib_select_default() only when actually necessary.
fib_select_default() is a complete NOP, and completely pointless
to invoke, when we have no more than 1 default route installed.

And this is far and away the common case.

So remember how many prefixlen==0 routes we have in the routing
table, and elide the call when we have no more than one of those.

This cuts output route creation time by 157 cycles on Niagara2+.

In order to add the new int to fib_table, we have to correct the type
of ->tb_data[] to unsigned long, otherwise the private area will be
unaligned on 64-bit systems.

Signed-off-by: David S. Miller <davem@davemloft.net>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
2011-04-14 15:05:22 -07:00
David S. Miller
1c01a80cfe Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	drivers/net/smsc911x.c
2011-04-11 13:44:25 -07:00
Linus Torvalds
c44eaf41a5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (34 commits)
  net: Add support for SMSC LAN9530, LAN9730 and LAN89530
  mlx4_en: Restoring RX buffer pointer in case of failure
  mlx4: Sensing link type at device initialization
  ipv4: Fix "Set rt->rt_iif more sanely on output routes."
  MAINTAINERS: add entry for Xen network backend
  be2net: Fix suspend/resume operation
  be2net: Rename some struct members for clarity
  pppoe: drop PPPOX_ZOMBIEs in pppoe_flush_dev
  dsa/mv88e6131: add support for mv88e6085 switch
  ipv6: Enable RFS sk_rxhash tracking for ipv6 sockets (v2)
  be2net: Fix a potential crash during shutdown.
  bna: Fix for handling firmware heartbeat failure
  can: mcp251x: Allow pass IRQ flags through platform data.
  smsc911x: fix mac_lock acquision before calling smsc911x_mac_read
  iwlwifi: accept EEPROM version 0x423 for iwl6000
  rt2x00: fix cancelling uninitialized work
  rtlwifi: Fix some warnings/bugs
  p54usb: IDs for two new devices
  wl12xx: fix potential buffer overflow in testmode nvs push
  zd1211rw: reset rx idle timer from tasklet
  ...
2011-04-11 07:27:24 -07:00
Michael Smith
5c04c819a2 fib_validate_source(): pass sk_buff instead of mark
This makes sk_buff available for other use in fib_validate_source().

Signed-off-by: Michael Smith <msmith@cbnco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-10 18:50:59 -07:00
OGAWA Hirofumi
1b86a58f9d ipv4: Fix "Set rt->rt_iif more sanely on output routes."
Commit 1018b5c016 ("Set rt->rt_iif more
sanely on output routes.")  breaks rt_is_{output,input}_route.

This became the cause to return "IP_PKTINFO's ->ipi_ifindex == 0".

To fix it, this does:

1) Add "int rt_route_iif;" to struct rtable

2) For input routes, always set rt_route_iif to same value as rt_iif

3) For output routes, always set rt_route_iif to zero.  Set rt_iif
   as it is done currently.

4) Change rt_is_{output,input}_route() to test rt_route_iif

Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-07 14:04:08 -07:00
Lucas De Marchi
25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
David S. Miller
436c3b66ec ipv4: Invalidate nexthop cache nh_saddr more correctly.
Any operation that:

1) Brings up an interface
2) Adds an IP address to an interface
3) Deletes an IP address from an interface

can potentially invalidate the nh_saddr value, requiring
it to be recomputed.

Perform the recomputation lazily using a generation ID.

Reported-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-24 17:42:21 -07:00
Eric Dumazet
eb49a97363 ipv4: fix ip_rt_update_pmtu()
commit 2c8cec5c10 (Cache learned PMTU information in inetpeer) added
an extra inet_putpeer() call in ip_rt_update_pmtu().

This results in various problems, since we can free one inetpeer, while
it is still in use.

Ref: http://www.spinics.net/lists/netdev/msg159121.html

Reported-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-23 12:18:15 -07:00
Dan Siemon
4a2b9c3756 net_sched: fix ip_tos2prio
ECN support incorrectly maps ECN BESTEFFORT packets to TC_PRIO_FILLER
(1) instead of TC_PRIO_BESTEFFORT (0)

This means ECN enabled flows are placed in pfifo_fast/prio low priority
band, giving ECN enabled flows [ECT(0) and CE codepoints] higher drop
probabilities.

This is rather unfortunate, given we would like ECN being more widely
used.

Ref : http://www.coverfire.com/archives/2011/03/13/pfifo_fast-and-ecn/

Signed-off-by: Dan Siemon <dan@coverfire.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Dave Täht <d@taht.net>
Cc: Jonathan Morton <chromatix99@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-15 18:53:54 -07:00
Hiroaki SHIMODA
46af31800b ipv4: Fix PMTU update.
On current net-next-2.6, when Linux receives ICMP Type: 3, Code: 4
(Destination unreachable (Fragmentation needed)),

  icmp_unreach
    -> ip_rt_frag_needed
         (peer->pmtu_expires is set here)
    -> tcp_v4_err
         -> do_pmtu_discovery
              -> ip_rt_update_pmtu
                   (peer->pmtu_expires is already set,
                    so check_peer_pmtu is skipped.)
                   -> check_peer_pmtu

check_peer_pmtu is skipped and MTU is not updated.

To fix this, let check_peer_pmtu execute unconditionally.
And some minor fixes
1) Avoid potential peer->pmtu_expires set to be zero.
2) In check_peer_pmtu, argument of time_before is reversed.
3) check_peer_pmtu expects peer->pmtu_orig is initialized as zero,
   but not initialized.

Signed-off-by: Hiroaki SHIMODA <shimoda.hiroaki@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-13 18:37:49 -07:00
David S. Miller
9d6ec93801 ipv4: Use flowi4 in public route lookup interfaces.
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-12 15:08:48 -08:00
David S. Miller
68a5e3dd0a ipv4: Use struct flowi4 internally in routing lookups.
We will change the externally visible APIs next.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-12 15:08:48 -08:00
David S. Miller
22bd5b9b13 ipv4: Pass ipv4 flow objects into fib_lookup() paths.
To start doing these conversions, we need to add some temporary
flow4_* macros which will eventually go away when all the protocol
code paths are changed to work on AF specific flowi objects.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-12 15:08:47 -08:00
David S. Miller
1d28f42c1b net: Put flowi_* prefix on AF independent members of struct flowi
I intend to turn struct flowi into a union of AF specific flowi
structs.  There will be a common structure that each variant includes
first, much like struct sock_common.

This is the first step to move in that direction.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-12 15:08:44 -08:00
David S. Miller
1b7fe59322 ipv4: Kill flowi arg to fib_select_multipath()
Completely unused.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-10 17:03:45 -08:00
David S. Miller
ff3fccb3d0 ipv4: Remove unnecessary test from ip_mkroute_input()
fl->oif will always be zero on the input path, so there is no reason
to test for that.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-10 17:01:01 -08:00
David S. Miller
dbdd9a52e3 ipv4: Remove redundant RCU locking in ip_check_mc().
All callers are under rcu_read_lock() protection already.

Rename to ip_check_mc_rcu() to make it even more clear.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-10 16:37:26 -08:00
David S. Miller
67e28ffd86 ipv4: Optimize flow initialization in input route lookup.
Like in commit 44713b67db
("ipv4: Optimize flow initialization in output route lookup."
we can optimize the on-stack flow setup to only initialize
the members which are actually used.

Otherwise we bzero the entire structure, then initialize
explicitly the first half of it.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-09 20:42:07 -08:00
David S. Miller
5e2b61f784 ipv4: Remove flowi from struct rtable.
The only necessary parts are the src/dst addresses, the
interface indexes, the TOS, and the mark.

The rest is unnecessary bloat, which amounts to nearly
50 bytes on 64-bit.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-04 21:55:31 -08:00
David S. Miller
1018b5c016 ipv4: Set rt->rt_iif more sanely on output routes.
rt->rt_iif is only ever inspected on input routes, for example DCCP
uses this to populate a route lookup flow key when generating replies
to another packet.

Therefore, setting it to anything other than zero on output routes
makes no sense.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-04 21:35:25 -08:00
David S. Miller
3c0afdca44 ipv4: Get peer more cheaply in rt_init_metrics().
We know this is a new route object, so doing atomics and
stuff makes no sense at all.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-04 21:26:07 -08:00
David S. Miller
44713b67db ipv4: Optimize flow initialization in output route lookup.
We burn a lot of useless cycles, cpu store buffer traffic, and
memory operations memset()'ing the on-stack flow used to perform
output route lookups in __ip_route_output_key().

Only the first half of the flow object members even matter for
output route lookups in this context, specifically:

FIB rules matching cares about:

	dst, src, tos, iif, oif, mark

FIB trie lookup cares about:

	dst

FIB semantic match cares about:

	tos, scope, oif

Therefore only initialize these specific members and elide the
memset entirely.

On Niagara2 this kills about ~300 cycles from the output route
lookup path.

Likely, we can take things further, since all callers of output
route lookups essentially throw away the on-stack flow they use.
So they don't care if we use it as a scratch-pad to compute the
final flow key.

Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
2011-03-04 21:24:47 -08:00
David S. Miller
5bfa787fb2 ipv4: ip_route_output_key() is better as an inline.
This avoid a stack frame at zero cost.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-02 14:56:30 -08:00
David S. Miller
b23dd4fe42 ipv4: Make output route lookup return rtable directly.
Instead of on the stack.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-02 14:31:35 -08:00
David S. Miller
452edd598f xfrm: Return dst directly from xfrm_lookup()
Instead of on the stack.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-02 13:27:41 -08:00
David S. Miller
2774c131b1 xfrm: Handle blackhole route creation via afinfo.
That way we don't have to potentially do this in every xfrm_lookup()
caller.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-01 14:59:04 -08:00
David S. Miller
80c0bc9e37 xfrm: Kill XFRM_LOOKUP_WAIT flag.
This can be determined from the flow flags instead.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-01 14:36:37 -08:00
David S. Miller
273447b352 ipv4: Kill can_sleep arg to ip_route_output_flow()
This boolean state is now available in the flow flags.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-01 14:27:04 -08:00
David S. Miller
420d44daa7 ipv4: Make final arg to ip_route_output_flow to be boolean "can_sleep"
Since that is what the current vague "flags" argument means.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-01 14:19:23 -08:00
David S. Miller
da935c66ba Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	Documentation/feature-removal-schedule.txt
	drivers/net/e1000e/netdev.c
	net/xfrm/xfrm_policy.c
2011-02-19 19:17:35 -08:00
Eric Dumazet
214f45c91b net: provide default_advmss() methods to blackhole dst_ops
Commit 0dbaee3b37 (net: Abstract default ADVMSS behind an
accessor.) introduced a possible crash in tcp_connect_init(), when
dst->default_advmss() is called from dst_metric_advmss()

Reported-by: George Spelvin <linux@horizon.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-18 11:39:01 -08:00
David S. Miller
982721f391 ipv4: Use const'ify fib_result deep in the route call chains.
The only troublesome bit here is __mkroute_output which wants
to override res->fi and res->type, compute those in local
variables instead.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-17 15:54:42 -08:00
David S. Miller
3c7bd1a140 net: Add initial_ref arg to dst_alloc().
This allows avoiding multiple writes to the initial __refcnt.

The most simplest cases of wanting an initial reference of "1"
in ipv4 and ipv6 have been converted, the rest have been left
along and kept at the existing "0".

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-17 15:44:00 -08:00
David S. Miller
0c4dcd58fd ipv4: Consolidate ipv4 dst allocation logic.
This also allows us to combine all the dst->flags settings and avoid
read/modify/write sequences to this struct member.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-17 15:42:37 -08:00
David S. Miller
010c2708e5 ipv4: Move rcu_read_{lock,unlock}() into ip_route_output_slow().
Simplifies tail of __ip_route_output_key().

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-17 15:37:09 -08:00
David S. Miller
5ada552746 ipv4: Simplify output route creation call sequence.
There's a lot of redundancy and unnecessary stack frames
in the output route creation path.

1) Make __mkroute_output() return error pointers.

2) Eliminate ip_mkroute_output() entirely, made possible by #1.

3) Call __mkroute_output() directly and handling the returning error
   pointers in ip_route_output_slow().

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-17 15:29:00 -08:00
David S. Miller
f39925dbde ipv4: Cache learned redirect information in inetpeer.
Note that we do not generate the redirect netevent any longer,
because we don't create a new cached route.

Instead, once the new neighbour is bound to the cached route,
we emit a neigh update event instead.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-14 21:33:27 -08:00
David S. Miller
2c8cec5c10 ipv4: Cache learned PMTU information in inetpeer.
The general idea is that if we learn new PMTU information, we
bump the peer genid.

This triggers the dst_ops->check() code to validate and if
necessary propagate the new PMTU value into the metrics.

Learned PMTU information self-expires.

This means that it is not necessary to kill a cached route
entry just because the PMTU information is too old.

As a consequence:

1) When the path appears unreachable (dst_ops->link_failure
   or dst_ops->negative_advice) we unwind the PMTU state if
   it is out of date, instead of killing the cached route.

   A redirected route will still be invalidated in these
   situations.

2) rt_check_expire(), rt_worker_func(), et al. are no longer
   necessary at all.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-14 21:33:07 -08:00
David S. Miller
6431cbc25f inet: Create a mechanism for upward inetpeer propagation into routes.
If we didn't have a routing cache, we would not be able to properly
propagate certain kinds of dynamic path attributes, for example
PMTU information and redirects.

The reason is that if we didn't have a routing cache, then there would
be no way to lookup all of the active cached routes hanging off of
sockets, tunnels, IPSEC bundles, etc.

Consider the case where we created a cached route, but no inetpeer
entry existed and also we were not asked to pre-COW the route metrics
and therefore did not force the creation a new inetpeer entry.

If we later get a PMTU message, or a redirect, and store this
information in a new inetpeer entry, there is no way to teach that
cached route about the newly existing inetpeer entry.

The facilities implemented here handle this problem.

First we create a generation ID.  When we create a cached route of any
kind, we remember the generation ID at the time of attachment.  Any
time we force-create an inetpeer entry in response to new path
information, we bump that generation ID.

The dst_ops->check() callback is where the knowledge of this event
is propagated.  If the global generation ID does not equal the one
stored in the cached route, and the cached route has not attached
to an inetpeer yet, we look it up and attach if one is found.  Now
that we've updated the cached route's information, we update the
route's generation ID too.

This clears the way for implementing PMTU and redirects directly in
the inetpeer cache.  There is absolutely no need to consult cached
route information in order to maintain this information.

At this point nothing bumps the inetpeer genids, that comes in the
later changes which handle PMTUs and redirects using inetpeers.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-10 13:33:41 -08:00
David S. Miller
8d13a2a9fb net: Kill NETEVENT_PMTU_UPDATE.
Nobody actually does anything in response to the event,
so just kill it off.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-08 16:17:55 -08:00
David S. Miller
92d8682926 inetpeer: Move ICMP rate limiting state into inet_peer entries.
Like metrics, the ICMP rate limiting bits are cached state about
a destination.  So move it into the inet_peer entries.

If an inet_peer cannot be bound (the reason is memory allocation
failure or similar), the policy is to allow.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-04 15:59:53 -08:00