`struct nf_hook_ops`, `struct nf_hook_state` and the `nf_hookfn`
function typedef appear in function and struct declarations and
definitions in a number of netfilter headers. The structs and typedef
themselves are defined by linux/netfilter.h but only when
CONFIG_NETFILTER is enabled. Define them unconditionally and add
forward declarations in order to remove CONFIG_NETFILTER conditionals
from the other headers.
Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Several header-files, Kconfig files and Makefiles have trailing
white-space. Remove it.
In netfilter/Kconfig, indent the type of CONFIG_NETFILTER_NETLINK_ACCT
correctly.
There are semicolons at the end of two function definitions in
include/net/netfilter/nf_conntrack_acct.h and
include/net/netfilter/nf_conntrack_ecache.h. Remove them.
Fix indentation in nf_conntrack_l4proto.h.
Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
linux/netfilter.h defines a number of struct and inline function
definitions which are only available is CONFIG_NETFILTER is enabled.
These structs and functions are used in declarations and definitions in
other header-files. Added preprocessor checks to make sure these
headers will compile if CONFIG_NETFILTER is disabled.
Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
struct nf_conn contains a "struct nf_conntrack ct_general" member and
struct net contains a "struct netns_ct ct" member which are both only
defined in CONFIG_NF_CONNTRACK is enabled. These members are used in a
number of inline functions defined in other header-files. Added
preprocessor checks to make sure the headers will compile if
CONFIG_NF_CONNTRACK is disabled.
Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Luca Moro says:
------
The issue lies in the filtering of ICMP and ICMPv6 errors that include an
inner IP datagram.
For these packets, icmp_error_message() extract the ICMP error and inner
layer to search of a known state.
If a state is found the packet is tagged as related (IP_CT_RELATED).
The problem is that there is no correlation check between the inner and
outer layer of the packet.
So one can encapsulate an error with an inner layer matching a known state,
while its outer layer is directed to a filtered host.
In this case the whole packet will be tagged as related.
This has various implications from a rule bypass (if a rule to related
trafic is allow), to a known state oracle.
Unfortunately, we could not find a real statement in a RFC on how this case
should be filtered.
The closest we found is RFC5927 (Section 4.3) but it is not very clear.
A possible fix would be to check that the inner IP source is the same than
the outer destination.
We believed this kind of attack was not documented yet, so we started to
write a blog post about it.
You can find it attached to this mail (sorry for the extract quality).
It contains more technical details, PoC and discussion about the identified
behavior.
We discovered later that
https://www.gont.com.ar/papers/filtering-of-icmp-error-messages.pdf
described a similar attack concept in 2004 but without the stateful
filtering in mind.
-----
This implements above suggested fix:
In icmp(v6) error handler, take outer destination address, then pass
that into the common function that does the "related" association.
After obtaining the nf_conn of the matching inner-headers connection,
check that the destination address of the opposite direction tuple
is the same as the outer address and only set RELATED if thats the case.
Reported-by: Luca Moro <luca.moro@synacktiv.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Its now same as __nf_ct_l4proto_find(), so rename that to
nf_ct_l4proto_find and use it everywhere.
It never returns NULL and doesn't need locks or reference counts.
Before this series:
302824 net/netfilter/nf_conntrack.ko
21504 net/netfilter/nf_conntrack_proto_gre.ko
text data bss dec hex filename
6281 1732 4 8017 1f51 nf_conntrack_proto_gre.ko
108356 20613 236 129205 1f8b5 nf_conntrack.ko
After:
294864 net/netfilter/nf_conntrack.ko
text data bss dec hex filename
106979 19557 240 126776 1ef38 nf_conntrack.ko
so, even with builtin gre, total size got reduced.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Only one user (gre), add a direct call and remove this facility.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Those were needed we still had modular trackers.
As we don't have those anymore, prefer direct calls and remove all
the (un)register infrastructure associated with this.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Now that all l4trackers are builtin, no need to use a mix of direct and
indirect calls.
This removes the last two users: gre and the generic l4 protocol
tracker.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
No need to get/put module owner reference, none of these can be removed
anymore.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Only used by icmp(v6). Prefer a direct call and remove this
function from the l4proto struct.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
GRE is now builtin, so we can handle it via direct call and
remove the callback.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This makes the last of the modular l4 trackers 'bool'.
After this, all infrastructure to handle dynamic l4 protocol registration
becomes obsolete and can be removed in followup patches.
Old:
302824 net/netfilter/nf_conntrack.ko
21504 net/netfilter/nf_conntrack_proto_gre.ko
New:
313728 net/netfilter/nf_conntrack.ko
Old:
text data bss dec hex filename
6281 1732 4 8017 1f51 nf_conntrack_proto_gre.ko
108356 20613 236 129205 1f8b5 nf_conntrack.ko
New:
112095 21381 240 133716 20a54 nf_conntrack.ko
The size increase is only temporary.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
rather than handling them via indirect call, use a direct one instead.
This leaves GRE as the last user of this indirect call facility.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The l4 protocol trackers are invoked via indirect call: l4proto->packet().
With one exception (gre), all l4trackers are builtin, so we can make
.packet optional and use a direct call for most protocols.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
All higher l4proto numbers are handled by the generic tracker; the
l4proto lookup function already returns generic one in case the l4proto
number exceeds max size.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
l4 protocols are demuxed by l3num, l4num pair.
However, almost all l4 trackers are l3 agnostic.
Only exceptions are:
- gre, icmp (ipv4 only)
- icmpv6 (ipv6 only)
This commit gets rid of the l3 mapping, l4 trackers can now be looked up
by their IPPROTO_XXX value alone, which gets rid of the additional l3
indirection.
For icmp, ipcmp6 and gre, add a check on state->pf and
return -NF_ACCEPT in case we're asked to track e.g. icmpv6-in-ipv4,
this seems more fitting than using the generic tracker.
Additionally we can kill the 2nd l4proto definitions that were needed
for v4/v6 split -- they are now the same so we can use single l4proto
struct for each protocol, rather than two.
The EXPORT_SYMBOLs can be removed as all these object files are
part of nf_conntrack with no external references.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Its unused, next patch will remove l4proto->l3proto number to simplify
l4 protocol demuxer lookup.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
icmp(v6) are the only two layer four protocols that need the error()
callback (to handle icmp errors that are related to an established
connections, e.g. packet too big, port unreachable and the like).
Remove the error callback and handle these two special cases from the core.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Only two protocols need the ->error() function: icmp and icmpv6.
This is because icmp error mssages might be RELATED to an existing
connection (e.g. PMTUD, port unreachable and the like), and their
->error() handlers do this.
The error callback is already optional, so remove it for
udp and call them from ->packet() instead.
As the error() callback can call checksum functions that write to
skb->csum*, the const qualifier has to be removed as well.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
->new() gets invoked after ->error() and before ->packet() if
a conntrack lookup has found no result for the tuple.
We can fold it into ->packet() -- the packet() implementations
can check if the conntrack is confirmed (new) or not
(already in hash).
If its unconfirmed, the conntrack isn't in the hash yet so current
skb created a new conntrack entry.
Only relevant side effect -- if packet() doesn't return NF_ACCEPT
but -NF_ACCEPT (or drop), while the conntrack was just created,
then the newly allocated conntrack is freed right away, rather than not
created in the first place.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nf_hook_state contains all the hook meta-information: netns, protocol family,
hook location, and so on.
Instead of only passing selected information, pass a pointer to entire
structure.
This will allow to merge the error and the packet handlers and remove
the ->new() function in followup patches.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This unifies ipv4 and ipv6 protocol trackers and removes the l3proto
abstraction.
This gets rid of all l3proto indirect calls and the need to do
a lookup on the function to call for l3 demux.
It increases module size by only a small amount (12kbyte), so this reduces
size because nf_conntrack.ko is useless without either nf_conntrack_ipv4
or nf_conntrack_ipv6 module.
before:
text data bss dec hex filename
7357 1088 0 8445 20fd nf_conntrack_ipv4.ko
7405 1084 4 8493 212d nf_conntrack_ipv6.ko
72614 13689 236 86539 1520b nf_conntrack.ko
19K nf_conntrack_ipv4.ko
19K nf_conntrack_ipv6.ko
179K nf_conntrack.ko
after:
text data bss dec hex filename
79277 13937 236 93450 16d0a nf_conntrack.ko
191K nf_conntrack.ko
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Not needed, we can have the l4trackers fetch it themselvs.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Handle the common cases (tcp, udp, etc). in the core and only
do the indirect call for the protocols that need it (GRE for instance).
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
previous patches removed all writes to these structs so we can
now mark them as const.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
similar to previous commit, but instead compute this at compile time
and turn nlattr_size into an u16.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
Netfilter/IPVS updates for net-next
The following patchset contains Netfilter/IPVS updates for your net-next
tree, they are:
1) Speed up table replacement on busy systems with large tables
(and many cores) in x_tables. Now xt_replace_table() synchronizes by
itself by waiting until all cpus had an even seqcount and we use no
use seqlock when fetching old counters, from Florian Westphal.
2) Add nf_l4proto_log_invalid() and nf_ct_l4proto_log_invalid() to speed
up packet processing in the fast path when logging is not enabled, from
Florian Westphal.
3) Precompute masked address from configuration plane in xt_connlimit,
from Florian.
4) Don't use explicit size for set selection if performance set policy
is selected.
5) Allow to get elements from an existing set in nf_tables.
6) Fix incorrect check in nft_hash_deactivate(), from Florian.
7) Cache netlink attribute size result in l4proto->nla_size, from
Florian.
8) Handle NFPROTO_INET in nf_ct_netns_get() from conntrack core.
9) Use power efficient workqueue in conntrack garbage collector, from
Vincent Guittot.
10) Remove unnecessary parameter, in conntrack l4proto functions, also
from Florian.
11) Constify struct nf_conntrack_l3proto definitions, from Florian.
12) Remove all typedefs in nf_conntrack_h323 via coccinelle semantic
patch, from Harsha Sharma.
13) Don't store address in the rbtree nodes in xt_connlimit, they are
never used, from Florian.
14) Fix out of bound access in the conntrack h323 helper, patch from
Eric Sesterhenn.
15) Print symbols for the address returned with %pS in IPVS, from
Helge Deller.
16) Proc output should only display its own netns in IPVS, from
KUWAZAWA Takuya.
17) Small clean up in size_entry_mwt(), from Colin Ian King.
18) Use test_and_clear_bit from nf_nat_proto_clean() instead of separated
non-atomic test and then clear bit, from Florian Westphal.
19) Consolidate prefix length maps in ipset, from Aaron Conole.
20) Fix sparse warnings in ipset, from Jozsef Kadlecsik.
21) Simplify list_set_memsize(), from simran singhal.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
We currently call ->nlattr_tuple_size() once at register time and
cache result in l4proto->nla_size.
nla_size is the only member that is written to, avoiding this would
allow to make l4proto trackers const.
We can use ->nlattr_tuple_size() at run time, and cache result in
the individual trackers instead.
This is an intermediate step, next patch removes nlattr_size()
callback and computes size at compile time, then removes nla_size.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We currently pass down the l4 protocol to the conntrack ->packet()
function, but the only user of this is the debug info decision.
Same information can be derived from struct nf_conn.
Add a wrapper for the previous patch that extracs the information
from nf_conn and passes it to nf_l4proto_log_invalid().
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
We currently pass down the l4 protocol to the conntrack ->packet()
function, but the only user of this is the debug info decision.
Same information can be derived from struct nf_conn.
As a first step, add and use a new log function for this, similar to
nf_ct_helper_log().
Add __cold annotation -- invalid packets should be infrequent so
gcc can consider all call paths that lead to such a function as
unlikely.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Doesn't change generated code, but will make it easier to eventually
make the actual trackers themselvers const.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
CONFIG_NF_CONNTRACK_PROCFS is deprecated, no need to use a function
pointer in the trackers for this. Place the printf formatting in
the one place that uses it.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
can use u16 for both, shrinks size by another 8 bytes.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
no need to waste storage for something that is only needed
in one place and can be deduced from protocol number.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When a nf_conntrack_l3/4proto parameter is not on the left hand side
of an assignment, its address is not taken, and it is not passed to a
function that may modify its fields, then it can be declared as const.
This change is useful from a documentation point of view, and can
possibly facilitate making some nf_conntrack_l3/4proto structures const
subsequently.
Done with the help of Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If insertion of a new conntrack fails because the table is full, the kernel
searches the next buckets of the hash slot where the new connection
was supposed to be inserted at for an entry that hasn't seen traffic
in reply direction (non-assured), if it finds one, that entry is
is dropped and the new connection entry is allocated.
Allow the conntrack gc worker to also remove *assured* conntracks if
resources are low.
Do this by querying the l4 tracker, e.g. tcp connections are now dropped
if they are no longer established (e.g. in finwait).
This could be refined further, e.g. by adding 'soft' established timeout
(i.e., a timeout that is only used once we get close to resource
exhaustion).
Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
It is never accessed for reading and the only places that write to it
are the icmp(6) handlers, which also set skb->nfct (and skb->nfctinfo).
The conntrack core specifically checks for attached skb->nfct after
->error() invocation and returns early in this case.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Make struct pernet_operations::id unsigned.
There are 2 reasons to do so:
1)
This field is really an index into an zero based array and
thus is unsigned entity. Using negative value is out-of-bound
access by definition.
2)
On x86_64 unsigned 32-bit data which are mixed with pointers
via array indexing or offsets added or subtracted to pointers
are preffered to signed 32-bit data.
"int" being used as an array index needs to be sign-extended
to 64-bit before being used.
void f(long *p, int i)
{
g(p[i]);
}
roughly translates to
movsx rsi, esi
mov rdi, [rsi+...]
call g
MOVSX is 3 byte instruction which isn't necessary if the variable is
unsigned because x86_64 is zero extending by default.
Now, there is net_generic() function which, you guessed it right, uses
"int" as an array index:
static inline void *net_generic(const struct net *net, int id)
{
...
ptr = ng->ptr[id - 1];
...
}
And this function is used a lot, so those sign extensions add up.
Patch snipes ~1730 bytes on allyesconfig kernel (without all junk
messing with code generation):
add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)
Unfortunately some functions actually grow bigger.
This is a semmingly random artefact of code generation with register
allocator being used differently. gcc decides that some variable
needs to live in new r8+ registers and every access now requires REX
prefix. Or it is shifted into r12, so [r12+0] addressing mode has to be
used which is longer than [r8]
However, overall balance is in negative direction:
add/remove: 0/0 grow/shrink: 70/598 up/down: 396/-2126 (-1730)
function old new delta
nfsd4_lock 3886 3959 +73
tipc_link_build_proto_msg 1096 1140 +44
mac80211_hwsim_new_radio 2776 2808 +32
tipc_mon_rcv 1032 1058 +26
svcauth_gss_legacy_init 1413 1429 +16
tipc_bcbase_select_primary 379 392 +13
nfsd4_exchange_id 1247 1260 +13
nfsd4_setclientid_confirm 782 793 +11
...
put_client_renew_locked 494 480 -14
ip_set_sockfn_get 730 716 -14
geneve_sock_add 829 813 -16
nfsd4_sequence_done 721 703 -18
nlmclnt_lookup_host 708 686 -22
nfsd4_lockt 1085 1063 -22
nfs_get_client 1077 1050 -27
tcf_bpf_init 1106 1076 -30
nfsd4_encode_fattr 5997 5930 -67
Total: Before=154856051, After=154854321, chg -0.00%
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
modify registration and deregistration of layer-4 protocol trackers to
facilitate inclusion of new elements into the current list of builtin
protocols. Both builtin (TCP, UDP, ICMP) and non-builtin (DCCP, GRE, SCTP,
UDPlite) layer-4 protocol trackers usually register/deregister themselves
using consecutive calls to nf_ct_l4proto_{,pernet}_{,un}register(...).
This sequence is interrupted and rolled back in case of error; in order to
simplify addition of builtin protocols, the input of the above functions
has been modified to allow registering/unregistering multiple protocols.
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This backward compatibility has been around for more than ten years,
since Yasuyuki Kozakai introduced IPv6 in conntrack. These days, we have
alternate /proc/net/nf_conntrack* entries, the ctnetlink interface and
the conntrack utility got adopted by many people in the user community
according to what I observed on the netfilter user mailing list.
So let's get rid of this.
Note that nf_conntrack_htable_size and unsigned int nf_conntrack_max do
not need to be exported as symbol anymore.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
