Back in the day, skb_ensure_writable did not exist. By now, both functions
have the same precondition:
I. skb_make_writable will test in this order:
1. wlen > skb->len -> error
2. if not cloned and wlen <= headlen -> OK
3. If cloned and wlen bytes of clone writeable -> OK
After those checks, skb is either not cloned but needs to pull from
nonlinear area, or writing to head would also alter data of another clone.
In both cases skb_make_writable will then call __pskb_pull_tail, which will
kmalloc a new memory area to use for skb->head.
IOW, after successful skb_make_writable call, the requested length is in
linear area and can be modified, even if skb was cloned.
II. skb_ensure_writable will do this instead:
1. call pskb_may_pull. This handles case 1 above.
After this, wlen is in linear area, but skb might be cloned.
2. return if skb is not cloned
3. return if wlen byte of clone are writeable.
4. fully copy the skb.
So post-conditions are the same:
*len bytes are writeable in linear area without altering any payload data
of a clone, all header pointers might have been changed.
Only differences are that skb_ensure_writable is in the core, whereas
skb_make_writable lives in netfilter core and the inverted return value.
skb_make_writable returns 0 on error, whereas skb_ensure_writable returns
negative value.
For the normal cases performance is similar:
A. skb is not cloned and in linear area:
pskb_may_pull is inline helper, so neither function copies.
B. skb is cloned, write is in linear area and clone is writeable:
both funcions return with step 3.
This series removes skb_make_writable from the kernel.
While at it, pass the needed value instead, its less confusing that way:
There is no special-handling of "0-length" argument in either
skb_make_writable or skb_ensure_writable.
bridge already makes sure ethernet header is in linear area, only purpose
of the make_writable() is is to copy skb->head in case of cloned skbs.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add SPDX license identifiers to all files which:
- Have no license information of any form
- Have MODULE_LICENCE("GPL*") inside which was used in the initial
scan/conversion to ignore the file
These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:
GPL-2.0-only
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Use the new helper function ebt_invalid_target instead of the old
macro INVALID_TARGET and other duplicated codes to enhance the readability.
Signed-off-by: Gao Feng <gfree.wind@vip.163.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Convert the uses of memcpy to ether_addr_copy because
for some architectures it is smaller and faster.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Spaces required before the open parenthesis '(', before the open
brace '{', after that ',' and around that '?/:'.
Signed-off-by: Tan Xiaojun <tanxiaojun@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Restore function signatures from bool to int so that we can report
memory allocation failures or similar using -ENOMEM rather than
always having to pass -EINVAL back.
// <smpl>
@@
type bool;
identifier check, par;
@@
-bool check
+int check
(struct xt_tgchk_param *par) { ... }
// </smpl>
Minus the change it does to xt_ct_find_proto.
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
This will cause trouble once CONFIG_COMPAT support is added to ebtables.
xt_compat_*_offset() calculate the kernel/userland structure size delta
using:
XT_ALIGN(size) - COMPAT_XT_ALIGN(size)
If the match/target sizes are aligned at registration time,
delta is always zero.
Should have zero effect for existing systems: xtables uses
XT_ALIGN() whenever it deals with match/target sizes.
Signed-off-by: Florian Westphal <fwestphal@astaro.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
This patch does this for target extensions' checkentry functions.
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
This patch does this for target extensions' target functions.
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Ebtables ORs (1 << NF_BR_NUMHOOKS) into the hook mask to indicate that
the extension was called from a base chain. So this also needs to be
present in the extensions' ->hooks.
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
The function ebt_do_table doesn't take NF_DROP as a verdict from the targets.
Signed-off-by: Joonwoo Park <joonwpark81@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
http://bugzilla.kernel.org/show_bug.cgi?id=9920
The function skb_make_writable returns true or false.
Signed-off-by: Joonwoo Park <joonwpark81@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Update the MODULES_DESCRIPTION() tags for all Ebtables modules.
Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
With all the users of the double pointers removed, this patch mops up by
finally replacing all occurances of sk_buff ** in the netfilter API by
sk_buff *.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch replaces unnecessary uses of skb_copy, pskb_copy and
skb_realloc_headroom by functions such as skb_make_writable and
pskb_expand_head.
This allows us to remove the double pointers later.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
The attached patch adds --snat-arp support, which makes it possible to
change the source mac address in both the mac header and the arp header
with one rule.
Signed-off-by: Bart De Schuymer <bdschuym@pandora.be>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Every netfilter module uses `init' for its module_init() function and
`fini' or `cleanup' for its module_exit() function.
Problem is, this creates uninformative initcall_debug output and makes
ctags rather useless.
So go through and rename them all to $(filename)_init and
$(filename)_fini.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Florian Westphal