2012-08-26 19:14:06 +02:00
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/* nf_nat_helper.c - generic support functions for NAT helpers
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2006-12-03 07:07:13 +01:00
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*
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* (C) 2000-2002 Harald Welte <laforge@netfilter.org>
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* (C) 2003-2006 Netfilter Core Team <coreteam@netfilter.org>
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2013-04-06 15:24:29 +02:00
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* (C) 2007-2012 Patrick McHardy <kaber@trash.net>
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2006-12-03 07:07:13 +01:00
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/module.h>
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include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 09:04:11 +01:00
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#include <linux/gfp.h>
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2006-12-03 07:07:13 +01:00
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#include <linux/types.h>
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#include <linux/skbuff.h>
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#include <linux/tcp.h>
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#include <linux/udp.h>
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#include <net/tcp.h>
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#include <net/netfilter/nf_conntrack.h>
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#include <net/netfilter/nf_conntrack_helper.h>
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2007-12-18 07:28:00 +01:00
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#include <net/netfilter/nf_conntrack_ecache.h>
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2006-12-03 07:07:13 +01:00
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#include <net/netfilter/nf_conntrack_expect.h>
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2013-08-27 08:50:12 +02:00
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#include <net/netfilter/nf_conntrack_seqadj.h>
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2006-12-03 07:07:13 +01:00
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#include <net/netfilter/nf_nat.h>
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2012-08-26 19:14:06 +02:00
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#include <net/netfilter/nf_nat_l3proto.h>
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#include <net/netfilter/nf_nat_l4proto.h>
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2006-12-03 07:07:13 +01:00
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#include <net/netfilter/nf_nat_core.h>
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#include <net/netfilter/nf_nat_helper.h>
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/* Frobs data inside this packet, which is linear. */
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static void mangle_contents(struct sk_buff *skb,
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unsigned int dataoff,
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unsigned int match_offset,
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unsigned int match_len,
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const char *rep_buffer,
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unsigned int rep_len)
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{
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unsigned char *data;
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BUG_ON(skb_is_nonlinear(skb));
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2007-04-21 07:47:35 +02:00
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data = skb_network_header(skb) + dataoff;
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2006-12-03 07:07:13 +01:00
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/* move post-replacement */
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memmove(data + match_offset + rep_len,
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data + match_offset + match_len,
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2013-05-30 18:39:29 +02:00
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skb_tail_pointer(skb) - (skb_network_header(skb) + dataoff +
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2007-04-20 05:29:13 +02:00
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match_offset + match_len));
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2006-12-03 07:07:13 +01:00
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/* insert data from buffer */
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memcpy(data + match_offset, rep_buffer, rep_len);
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/* update skb info */
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if (rep_len > match_len) {
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2007-07-08 07:39:38 +02:00
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pr_debug("nf_nat_mangle_packet: Extending packet by "
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"%u from %u bytes\n", rep_len - match_len, skb->len);
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2006-12-03 07:07:13 +01:00
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skb_put(skb, rep_len - match_len);
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} else {
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2007-07-08 07:39:38 +02:00
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pr_debug("nf_nat_mangle_packet: Shrinking packet from "
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"%u from %u bytes\n", match_len - rep_len, skb->len);
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2006-12-03 07:07:13 +01:00
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__skb_trim(skb, skb->len + rep_len - match_len);
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}
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2012-08-26 19:14:06 +02:00
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if (nf_ct_l3num((struct nf_conn *)skb->nfct) == NFPROTO_IPV4) {
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/* fix IP hdr checksum information */
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ip_hdr(skb)->tot_len = htons(skb->len);
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ip_send_check(ip_hdr(skb));
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} else
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ipv6_hdr(skb)->payload_len =
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htons(skb->len - sizeof(struct ipv6hdr));
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2006-12-03 07:07:13 +01:00
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}
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/* Unusual, but possible case. */
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2007-10-15 09:53:15 +02:00
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static int enlarge_skb(struct sk_buff *skb, unsigned int extra)
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2006-12-03 07:07:13 +01:00
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{
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2007-10-15 09:53:15 +02:00
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if (skb->len + extra > 65535)
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2006-12-03 07:07:13 +01:00
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return 0;
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2007-10-15 09:53:15 +02:00
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if (pskb_expand_head(skb, 0, extra - skb_tailroom(skb), GFP_ATOMIC))
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2006-12-03 07:07:13 +01:00
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return 0;
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return 1;
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}
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/* Generic function for mangling variable-length address changes inside
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* NATed TCP connections (like the PORT XXX,XXX,XXX,XXX,XXX,XXX
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* command in FTP).
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*
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* Takes care about all the nasty sequence number changes, checksumming,
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* skb enlargement, ...
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*
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* */
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2010-02-11 12:27:09 +01:00
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int __nf_nat_mangle_tcp_packet(struct sk_buff *skb,
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struct nf_conn *ct,
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enum ip_conntrack_info ctinfo,
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2012-08-26 19:14:04 +02:00
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unsigned int protoff,
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2010-02-11 12:27:09 +01:00
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unsigned int match_offset,
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unsigned int match_len,
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const char *rep_buffer,
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unsigned int rep_len, bool adjust)
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2006-12-03 07:07:13 +01:00
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{
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2012-08-26 19:14:06 +02:00
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const struct nf_nat_l3proto *l3proto;
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2006-12-03 07:07:13 +01:00
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struct tcphdr *tcph;
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int oldlen, datalen;
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2007-10-15 09:53:15 +02:00
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if (!skb_make_writable(skb, skb->len))
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2006-12-03 07:07:13 +01:00
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return 0;
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if (rep_len > match_len &&
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2007-10-15 09:53:15 +02:00
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rep_len - match_len > skb_tailroom(skb) &&
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!enlarge_skb(skb, rep_len - match_len))
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2006-12-03 07:07:13 +01:00
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return 0;
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2007-10-15 09:53:15 +02:00
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SKB_LINEAR_ASSERT(skb);
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2006-12-03 07:07:13 +01:00
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2012-08-26 19:14:06 +02:00
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tcph = (void *)skb->data + protoff;
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2006-12-03 07:07:13 +01:00
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2012-08-26 19:14:06 +02:00
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oldlen = skb->len - protoff;
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mangle_contents(skb, protoff + tcph->doff*4,
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2006-12-03 07:07:13 +01:00
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match_offset, match_len, rep_buffer, rep_len);
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2012-08-26 19:14:06 +02:00
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datalen = skb->len - protoff;
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l3proto = __nf_nat_l3proto_find(nf_ct_l3num(ct));
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l3proto->csum_recalc(skb, IPPROTO_TCP, tcph, &tcph->check,
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datalen, oldlen);
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2006-12-03 07:07:13 +01:00
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2010-02-11 12:27:09 +01:00
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if (adjust && rep_len != match_len)
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2013-08-27 08:50:12 +02:00
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nf_ct_seqadj_set(ct, ctinfo, tcph->seq,
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(int)rep_len - (int)match_len);
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2010-02-11 12:27:09 +01:00
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2006-12-03 07:07:13 +01:00
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return 1;
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}
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2010-02-11 12:27:09 +01:00
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EXPORT_SYMBOL(__nf_nat_mangle_tcp_packet);
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2006-12-03 07:07:13 +01:00
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/* Generic function for mangling variable-length address changes inside
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* NATed UDP connections (like the CONNECT DATA XXXXX MESG XXXXX INDEX XXXXX
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* command in the Amanda protocol)
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*
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* Takes care about all the nasty sequence number changes, checksumming,
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* skb enlargement, ...
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*
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* XXX - This function could be merged with nf_nat_mangle_tcp_packet which
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* should be fairly easy to do.
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*/
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int
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2007-10-15 09:53:15 +02:00
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nf_nat_mangle_udp_packet(struct sk_buff *skb,
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2006-12-03 07:07:13 +01:00
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struct nf_conn *ct,
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enum ip_conntrack_info ctinfo,
|
2012-08-26 19:14:04 +02:00
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unsigned int protoff,
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2006-12-03 07:07:13 +01:00
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unsigned int match_offset,
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unsigned int match_len,
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const char *rep_buffer,
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unsigned int rep_len)
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{
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2012-08-26 19:14:06 +02:00
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const struct nf_nat_l3proto *l3proto;
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2006-12-03 07:07:13 +01:00
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struct udphdr *udph;
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int datalen, oldlen;
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2007-10-15 09:53:15 +02:00
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if (!skb_make_writable(skb, skb->len))
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2006-12-03 07:07:13 +01:00
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return 0;
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if (rep_len > match_len &&
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2007-10-15 09:53:15 +02:00
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rep_len - match_len > skb_tailroom(skb) &&
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!enlarge_skb(skb, rep_len - match_len))
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2006-12-03 07:07:13 +01:00
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return 0;
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2012-08-26 19:14:06 +02:00
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udph = (void *)skb->data + protoff;
|
2006-12-03 07:07:13 +01:00
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2012-08-26 19:14:06 +02:00
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oldlen = skb->len - protoff;
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mangle_contents(skb, protoff + sizeof(*udph),
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2006-12-03 07:07:13 +01:00
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match_offset, match_len, rep_buffer, rep_len);
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/* update the length of the UDP packet */
|
2012-08-26 19:14:06 +02:00
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datalen = skb->len - protoff;
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2006-12-03 07:07:13 +01:00
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udph->len = htons(datalen);
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/* fix udp checksum if udp checksum was previously calculated */
|
2007-10-15 09:53:15 +02:00
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if (!udph->check && skb->ip_summed != CHECKSUM_PARTIAL)
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2006-12-03 07:07:13 +01:00
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return 1;
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2012-08-26 19:14:06 +02:00
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l3proto = __nf_nat_l3proto_find(nf_ct_l3num(ct));
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l3proto->csum_recalc(skb, IPPROTO_UDP, udph, &udph->check,
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datalen, oldlen);
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2006-12-03 07:07:13 +01:00
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return 1;
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}
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EXPORT_SYMBOL(nf_nat_mangle_udp_packet);
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/* Setup NAT on this expected conntrack so it follows master. */
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/* If we fail to get a free NAT slot, we'll get dropped on confirm */
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void nf_nat_follow_master(struct nf_conn *ct,
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struct nf_conntrack_expect *exp)
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{
|
2012-08-26 19:14:06 +02:00
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struct nf_nat_range range;
|
2006-12-03 07:07:13 +01:00
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/* This must be a fresh one. */
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BUG_ON(ct->status & IPS_NAT_DONE_MASK);
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/* Change src to where master sends to */
|
2011-12-23 13:59:49 +01:00
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range.flags = NF_NAT_RANGE_MAP_IPS;
|
2012-08-26 19:14:06 +02:00
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range.min_addr = range.max_addr
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= ct->master->tuplehash[!exp->dir].tuple.dst.u3;
|
2011-12-23 13:59:49 +01:00
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nf_nat_setup_info(ct, &range, NF_NAT_MANIP_SRC);
|
2006-12-03 07:07:13 +01:00
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/* For DST manip, map port here to where it's expected. */
|
2011-12-23 13:59:49 +01:00
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range.flags = (NF_NAT_RANGE_MAP_IPS | NF_NAT_RANGE_PROTO_SPECIFIED);
|
2012-08-26 19:14:06 +02:00
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range.min_proto = range.max_proto = exp->saved_proto;
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range.min_addr = range.max_addr
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= ct->master->tuplehash[!exp->dir].tuple.src.u3;
|
2011-12-23 13:59:49 +01:00
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nf_nat_setup_info(ct, &range, NF_NAT_MANIP_DST);
|
2006-12-03 07:07:13 +01:00
|
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}
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EXPORT_SYMBOL(nf_nat_follow_master);
|