Commit Graph

131 Commits

Author SHA1 Message Date
Alexey Dobriyan 4e3fd7a06d net: remove ipv6_addr_copy()
C assignment can handle struct in6_addr copying.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-22 16:43:32 -05:00
Eric Dumazet 2a24444f8f ipv6: reduce percpu needs for icmpv6msg mibs
Reading /proc/net/snmp6 on a machine with a lot of cpus is very
expensive (can be ~88000 us).

This is because ICMPV6MSG MIB uses 4096 bytes per cpu, and folding
values for all possible cpus can read 16 Mbytes of memory (32MBytes on
non x86 arches)

ICMP messages are not considered as fast path on a typical server, and
eventually few cpus handle them anyway. We can afford an atomic
operation instead of using percpu data.

This saves 4096 bytes per cpu and per network namespace.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-14 00:12:26 -05:00
Eric Dumazet b903d324be ipv6: tcp: fix TCLASS value in ACK messages sent from TIME_WAIT
commit 66b13d99d9 (ipv4: tcp: fix TOS value in ACK messages sent from
TIME_WAIT) fixed IPv4 only.

This part is for the IPv6 side, adding a tclass param to ip6_xmit()

We alias tw_tclass and tw_tos, if socket family is INET6.

[ if sockets is ipv4-mapped, only IP_TOS socket option is used to fill
TOS field, TCLASS is not taken into account ]

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-10-27 00:44:35 -04:00
Eric Dumazet 87c48fa3b4 ipv6: make fragment identifications less predictable
IPv6 fragment identification generation is way beyond what we use for
IPv4 : It uses a single generator. Its not scalable and allows DOS
attacks.

Now inetpeer is IPv6 aware, we can use it to provide a more secure and
scalable frag ident generator (per destination, instead of system wide)

This patch :
1) defines a new secure_ipv6_id() helper
2) extends inet_getid() to provide 32bit results
3) extends ipv6_select_ident() with a new dest parameter

Reported-by: Fernando Gont <fernando@gont.com.ar>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-21 21:25:58 -07:00
Eric Dumazet be281e554e ipv6: reduce per device ICMP mib sizes
ipv6 has per device ICMP SNMP counters, taking too much space because
they use percpu storage.

needed size per device is :
(512+4)*sizeof(long)*number_of_possible_cpus*2

On a 32bit kernel, 16 possible cpus, this wastes more than 64kbytes of
memory per ipv6 enabled network device, taken in vmalloc pool.

Since ICMP messages are rare, just use shared counters (atomic_long_t)

Per network space ICMP counters are still using percpu memory, we might
also convert them to shared counters in a future patch.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Denys Fedoryshchenko <denys@visp.net.lb>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-05-19 16:21:22 -04:00
David S. Miller 2a9e950701 net: Remove __KERNEL__ cpp checks from include/net
These header files are never installed to user consumption, so any
__KERNEL__ cpp checks are superfluous.

Projects should also not copy these files into their userland utility
sources and try to use them there.  If they insist on doing so, the
onus is on them to sanitize the headers as needed.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-04-24 10:54:56 -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 4c9483b2fb ipv6: Convert to use flowi6 where applicable.
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-12 15:08:54 -08:00
David S. Miller 0a0e9ae1bd Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	drivers/net/bnx2x/bnx2x.h
2011-03-03 21:27:42 -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 69ead7afdf ipv6: Normalize arguments to ip6_dst_blackhole().
Return a dst pointer which is potentitally error encoded.

Don't pass original dst pointer by reference, pass a struct net
instead of a socket, and elide the flow argument since it is
unnecessary.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-01 14:45:33 -08:00
David S. Miller a1414715f0 ipv6: Change final dst lookup arg name to "can_sleep"
Since it indicates whether we are invoked from a sleepable
context or not.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-01 14:32:04 -08:00
David S. Miller 68d0c6d34d ipv6: Consolidate route lookup sequences.
Route lookups follow a general pattern in the ipv6 code wherein
we first find the non-IPSEC route, potentially override the
flow destination address due to ipv6 options settings, and then
finally make an IPSEC search using either xfrm_lookup() or
__xfrm_lookup().

__xfrm_lookup() is used when we want to generate a blackhole route
if the key manager needs to resolve the IPSEC rules (in this case
-EREMOTE is returned and the original 'dst' is left unchanged).

Otherwise plain xfrm_lookup() is used and when asynchronous IPSEC
resolution is necessary, we simply fail the lookup completely.

All of these cases are encapsulated into two routines,
ip6_dst_lookup_flow and ip6_sk_dst_lookup_flow.  The latter of which
handles unconnected UDP datagram sockets.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-01 13:19:07 -08:00
Linus Lüssing 5ced133961 ipv6: Add IPv6 multicast address flag defines
This commit adds the missing IPv6 multicast address flag defines to
complement the already existing multicast address scope defines and to
be able to check these flags nicely in the future.

Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-22 10:07:27 -08:00
Eric Dumazet a02cec2155 net: return operator cleanup
Change "return (EXPR);" to "return EXPR;"

return is not a function, parentheses are not required.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-09-23 14:33:39 -07:00
Eric Dumazet 4ce3c183fc snmp: 64bit ipstats_mib for all arches
/proc/net/snmp and /proc/net/netstat expose SNMP counters.

Width of these counters is either 32 or 64 bits, depending on the size
of "unsigned long" in kernel.

This means user program parsing these files must already be prepared to
deal with 64bit values, regardless of user program being 32 or 64 bit.

This patch introduces 64bit snmp values for IPSTAT mib, where some
counters can wrap pretty fast if they are 32bit wide.

# netstat -s|egrep "InOctets|OutOctets"
    InOctets: 244068329096
    OutOctets: 244069348848

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-30 13:31:19 -07:00
Arnaud Ebalard 20c59de2e6 ipv6: Refactor update of IPv6 flowi destination address for srcrt (RH) option
There are more than a dozen occurrences of following code in the
IPv6 stack:

    if (opt && opt->srcrt) {
            struct rt0_hdr *rt0 = (struct rt0_hdr *) opt->srcrt;
            ipv6_addr_copy(&final, &fl.fl6_dst);
            ipv6_addr_copy(&fl.fl6_dst, rt0->addr);
            final_p = &final;
    }

Replace those with a helper. Note that the helper overrides final_p
in all cases. This is ok as final_p was previously initialized to
NULL when declared.

Signed-off-by: Arnaud Ebalard <arno@natisbad.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-06-02 07:08:31 -07:00
Alexey Dobriyan 4be929be34 kernel-wide: replace USHORT_MAX, SHORT_MAX and SHORT_MIN with USHRT_MAX, SHRT_MAX and SHRT_MIN
- C99 knows about USHRT_MAX/SHRT_MAX/SHRT_MIN, not
  USHORT_MAX/SHORT_MAX/SHORT_MIN.

- Make SHRT_MIN of type s16, not int, for consistency.

[akpm@linux-foundation.org: fix drivers/dma/timb_dma.c]
[akpm@linux-foundation.org: fix security/keys/keyring.c]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25 08:07:02 -07:00
Brian Haley 4b340ae20d IPv6: Complete IPV6_DONTFRAG support
Finally add support to detect a local IPV6_DONTFRAG event
and return the relevant data to the user if they've enabled
IPV6_RECVPATHMTU on the socket.  The next recvmsg() will
return no data, but have an IPV6_PATHMTU as ancillary data.

Signed-off-by: Brian Haley <brian.haley@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-23 23:35:29 -07:00
Brian Haley 13b52cd446 IPv6: Add dontfrag argument to relevant functions
Add dontfrag argument to relevant functions for
IPV6_DONTFRAG support, as well as allowing the value
to be passed-in via ancillary cmsg data.

Signed-off-by: Brian Haley <brian.haley@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-23 23:35:28 -07:00
Shan Wei 4e15ed4d93 net: replace ipfragok with skb->local_df
As Herbert Xu said: we should be able to simply replace ipfragok
with skb->local_df. commit f88037(sctp: Drop ipfargok in sctp_xmit function)
has droped ipfragok and set local_df value properly.

The patch kills the ipfragok parameter of .queue_xmit().

Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-04-15 23:36:37 -07:00
YOSHIFUJI Hideaki / 吉藤英明 d57b8fb8a8 ipv6: Use __fls() instead of fls() in __ipv6_addr_diff().
Because we have ensured that the argument is non-zero,
it is better to use __fls() and generate better code.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-03-30 23:28:46 -07:00
Ulrich Weber 45bb006090 ipv6: Remove IPV6_ADDR_RESERVED
RFC 4291 section 2.4 states that all uncategorized addresses
should be considered as Global Unicast.

This will remove IPV6_ADDR_RESERVED completely
and return IPV6_ADDR_UNICAST in ipv6_addr_type() instead.

Signed-off-by: Ulrich Weber <uweber@astaro.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-26 03:59:07 -08:00
Joe Perches 9874c41cd5 ipv6.h: reassembly: replace calculated magic number with multiplication
On Tue, 2010-02-16 at 16:47 +0100, Patrick McHardy wrote:
> Joe Perches wrote:
> >> @@ -246,6 +246,8 @@ extern int ipv6_opt_accepted(struct sock *sk, struct sk_buff *skb);
> >>  int ip6_frag_nqueues(struct net *net);
> >>  int ip6_frag_mem(struct net *net);
> >>
> >> +#define IPV6_FRAG_HIGH_THRESH	262144		/* == 256*1024 */
> >> +#define IPV6_FRAG_LOW_THRESH	196608		/* == 192*1024 */
> >>  #define IPV6_FRAG_TIMEOUT	(60*HZ)		/* 60 seconds */
> >
> > 196608 isn't a number I want to remember.
> > Is this better as:
> >
> > #define IPV6_FRAG_HIGH_THRESH	(256 * 1024)	/* 262144 */
> > #define IPV6_FRAG_LOW_THRESH	(192 * 1024)	/* 196608 */
>
> Please send a patch, I'll apply it once these patches are in Dave's
> tree.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-02-17 00:03:28 -08:00
Patrick McHardy 5d0aa2ccd4 netfilter: nf_conntrack: add support for "conntrack zones"
Normally, each connection needs a unique identity. Conntrack zones allow
to specify a numerical zone using the CT target, connections in different
zones can use the same identity.

Example:

iptables -t raw -A PREROUTING -i veth0 -j CT --zone 1
iptables -t raw -A OUTPUT -o veth1 -j CT --zone 1

Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-02-15 18:13:33 +01:00
Shan Wei 7c070aa947 IPv6: reassembly: replace magic number with macro definitions
Use macro to define high/low thresh value, refer to IPV6_FRAG_TIMEOUT.

Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2010-01-20 10:42:41 +01:00
Patrick McHardy 8fa9ff6849 netfilter: fix crashes in bridge netfilter caused by fragment jumps
When fragments from bridge netfilter are passed to IPv4 or IPv6 conntrack
and a reassembly queue with the same fragment key already exists from
reassembling a similar packet received on a different device (f.i. with
multicasted fragments), the reassembled packet might continue on a different
codepath than where the head fragment originated. This can cause crashes
in bridge netfilter when a fragment received on a non-bridge device (and
thus with skb->nf_bridge == NULL) continues through the bridge netfilter
code.

Add a new reassembly identifier for packets originating from bridge
netfilter and use it to put those packets in insolated queues.

Fixes http://bugzilla.kernel.org/show_bug.cgi?id=14805

Reported-and-Tested-by: Chong Qiao <qiaochong@loongson.cn>
Signed-off-by: Patrick McHardy <kaber@trash.net>
2009-12-15 16:59:59 +01:00
Patrick McHardy 0b5ccb2ee2 ipv6: reassembly: use seperate reassembly queues for conntrack and local delivery
Currently the same reassembly queue might be used for packets reassembled
by conntrack in different positions in the stack (PREROUTING/LOCAL_OUT),
as well as local delivery. This can cause "packet jumps" when the fragment
completing a reassembled packet is queued from a different position in the
stack than the previous ones.

Add a "user" identifier to the reassembly queue key to seperate the queues
of each caller, similar to what we do for IPv4.

Signed-off-by: Patrick McHardy <kaber@trash.net>
2009-12-15 16:59:18 +01:00
Eric Dumazet fd2c3ef761 net: cleanup include/net
This cleanup patch puts struct/union/enum opening braces,
in first line to ease grep games.

struct something
{

becomes :

struct something {

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-11-04 05:06:25 -08:00
David S. Miller b7058842c9 net: Make setsockopt() optlen be unsigned.
This provides safety against negative optlen at the type
level instead of depending upon (sometimes non-trivial)
checks against this sprinkled all over the the place, in
each and every implementation.

Based upon work done by Arjan van de Ven and feedback
from Linus Torvalds.

Signed-off-by: David S. Miller <davem@davemloft.net>
2009-09-30 16:12:20 -07:00
Sridhar Samudrala 7ea2f2c5a6 udpv6: Remove unused skb argument of ipv6_select_ident()
- move ipv6_select_ident() inline function to ipv6.h and remove the unused
  skb argument

Signed-off-by: Sridhar Samudrala <sri@us.ibm.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-07-12 14:29:28 -07:00
Neil Horman edf391ff17 snmp: add missing counters for RFC 4293
The IP MIB (RFC 4293) defines stats for InOctets, OutOctets, InMcastOctets and
OutMcastOctets:
http://tools.ietf.org/html/rfc4293
But it seems we don't track those in any way that easy to separate from other
protocols.  This patch adds those missing counters to the stats file. Tested
successfully by me

With help from Eric Dumazet.

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-04-27 02:45:02 -07:00
Harvey Harrison f3a7c66b5c net: replace __constant_{endian} uses in net headers
Base versions handle constant folding now.  For headers exposed to
userspace, we must only expose the __ prefixed versions.

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-02-14 22:58:35 -08:00
Denis V. Lunev 9261e53701 ipv6: making ip and icmp statistics per/namespace
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-08 11:16:45 -07:00
Denis V. Lunev 087fe24033 ipv6: added net argument to _DEVINC/_DEVADD
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-08 11:16:19 -07:00
Denis V. Lunev 55d43808eb ipv6: added net argument to ICMP6MSGIN_INC_STATS_BH
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-08 11:15:46 -07:00
Denis V. Lunev a712d3e859 ipv6: ICMP6MSGIN_INC_STATS is not used
Removed.

Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-08 11:15:26 -07:00
Denis V. Lunev 5a57d4c7fd ipv6: added net argument to ICMP6MSGOUT_INC_STATS_BH
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-08 11:15:05 -07:00
Denis V. Lunev 5c5d244bd3 ipv6: added net argument to ICMP6MSGOUT_INC_STATS
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-08 11:14:44 -07:00
Denis V. Lunev e41b5368e0 ipv6: added net argument to ICMP6_INC_STATS_BH
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-08 11:14:13 -07:00
Denis V. Lunev a862f6a6dc ipv6: added net argument to ICMP6_INC_STATS
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-08 11:13:58 -07:00
Denis V. Lunev 821d57776d ipv6: added net argument to IP6_ADD_STATS_BH
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-08 11:13:31 -07:00
Denis V. Lunev 483a47d2fe ipv6: added net argument to IP6_INC_STATS_BH
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-08 11:09:27 -07:00
Denis V. Lunev 3bd653c845 netns: add net parameter to IP6_INC_STATS
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-08 10:54:51 -07:00
Ilpo Järvinen 93c8b90f01 ipv6: almost identical frag hashing funcs combined
$ diff-funcs ip6qhashfn reassembly.c netfilter/nf_conntrack_reasm.c
 --- reassembly.c:ip6qhashfn()
 +++ netfilter/nf_conntrack_reasm.c:ip6qhashfn()
@@ -1,5 +1,5 @@
-static unsigned int ip6qhashfn(__be32 id, struct in6_addr *saddr,
-			       struct in6_addr *daddr)
+static unsigned int ip6qhashfn(__be32 id, const struct in6_addr *saddr,
+			       const struct in6_addr *daddr)
 {
 	u32 a, b, c;

@@ -9,7 +9,7 @@

 	a += JHASH_GOLDEN_RATIO;
 	b += JHASH_GOLDEN_RATIO;
-	c += ip6_frags.rnd;
+	c += nf_frags.rnd;
 	__jhash_mix(a, b, c);

 	a += (__force u32)saddr->s6_addr32[3];

And codiff xx.o.old xx.o.new:

net/ipv6/netfilter/nf_conntrack_reasm.c:
  ip6qhashfn         | -512
  nf_hashfn          |   +6
  nf_ct_frag6_gather |  +36
 3 functions changed, 42 bytes added, 512 bytes removed, diff: -470
net/ipv6/reassembly.c:
  ip6qhashfn    | -512
  ip6_hashfn    |   +7
  ipv6_frag_rcv |  +89
 3 functions changed, 96 bytes added, 512 bytes removed, diff: -416

net/ipv6/reassembly.c:
  inet6_hash_frag | +510
 1 function changed, 510 bytes added, diff: +510

Total: -376

Compile tested.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-01 02:48:31 -07:00
Al Viro eeb61f719c missing bits of net-namespace / sysctl
Piss-poor sysctl registration API strikes again, film at 11...

What we really need is _pathname_ required to be present in already
registered table, so that kernel could warn about bad order.  That's the
next target for sysctl stuff (and generally saner and more explicit
order of initialization of ipv[46] internals wouldn't hurt either).

For the time being, here are full fixups required by ..._rotable()
stuff; we make per-net sysctl sets descendents of "ro" one and make sure
that sufficient skeleton is there before we start registering per-net
sysctls.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-27 09:45:34 -07:00
Denis V. Lunev 7abbcd6a4c ipv6: remove unused macros from net/ipv6.h
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-19 00:29:42 -07:00
Denis V. Lunev 725a8ff04a ipv6: remove unused parameter from ip6_ra_control
Signed-off-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-19 00:28:58 -07:00
David S. Miller 1b63ba8a86 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:

	drivers/net/wireless/iwlwifi/iwl4965-base.c
2008-06-28 01:19:40 -07:00
YOSHIFUJI Hideaki f630e43a21 ipv6: Drop packets for loopback address from outside of the box.
[ Based upon original report and patch by Karsten Keil.  Karsten
  has verified that this fixes the TAHI test case "ICMPv6 test
  v6LC.5.1.2 Part F". -DaveM ]

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-06-19 16:33:57 -07:00