2013-04-06 21:24:29 +08:00
|
|
|
/*
|
|
|
|
|
* IPv4 specific functions of netfilter core
|
|
|
|
|
*
|
|
|
|
|
* Rusty Russell (C) 2000 -- This code is GPL.
|
|
|
|
|
* Patrick McHardy (C) 2006-2012
|
|
|
|
|
*/
|
2005-08-10 10:39:00 +08:00
|
|
|
#include <linux/kernel.h>
|
|
|
|
|
#include <linux/netfilter.h>
|
2005-08-10 10:42:34 +08:00
|
|
|
#include <linux/netfilter_ipv4.h>
|
2006-01-07 15:04:54 +08:00
|
|
|
#include <linux/ip.h>
|
2007-10-14 15:39:55 +08:00
|
|
|
#include <linux/skbuff.h>
|
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 16:04:11 +08:00
|
|
|
#include <linux/gfp.h>
|
2011-07-15 23:47:34 +08:00
|
|
|
#include <linux/export.h>
|
2005-08-10 10:39:00 +08:00
|
|
|
#include <net/route.h>
|
2006-01-07 15:04:54 +08:00
|
|
|
#include <net/xfrm.h>
|
|
|
|
|
#include <net/ip.h>
|
2007-12-05 17:24:48 +08:00
|
|
|
#include <net/netfilter/nf_queue.h>
|
2005-08-10 10:39:00 +08:00
|
|
|
|
|
|
|
|
/* route_me_harder function, used by iptable_nat, iptable_mangle + ip_queue */
|
netfilter: use actual socket sk rather than skb sk when routing harder
If netfilter changes the packet mark when mangling, the packet is
rerouted using the route_me_harder set of functions. Prior to this
commit, there's one big difference between route_me_harder and the
ordinary initial routing functions, described in the comment above
__ip_queue_xmit():
/* Note: skb->sk can be different from sk, in case of tunnels */
int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,
That function goes on to correctly make use of sk->sk_bound_dev_if,
rather than skb->sk->sk_bound_dev_if. And indeed the comment is true: a
tunnel will receive a packet in ndo_start_xmit with an initial skb->sk.
It will make some transformations to that packet, and then it will send
the encapsulated packet out of a *new* socket. That new socket will
basically always have a different sk_bound_dev_if (otherwise there'd be
a routing loop). So for the purposes of routing the encapsulated packet,
the routing information as it pertains to the socket should come from
that socket's sk, rather than the packet's original skb->sk. For that
reason __ip_queue_xmit() and related functions all do the right thing.
One might argue that all tunnels should just call skb_orphan(skb) before
transmitting the encapsulated packet into the new socket. But tunnels do
*not* do this -- and this is wisely avoided in skb_scrub_packet() too --
because features like TSQ rely on skb->destructor() being called when
that buffer space is truely available again. Calling skb_orphan(skb) too
early would result in buffers filling up unnecessarily and accounting
info being all wrong. Instead, additional routing must take into account
the new sk, just as __ip_queue_xmit() notes.
So, this commit addresses the problem by fishing the correct sk out of
state->sk -- it's already set properly in the call to nf_hook() in
__ip_local_out(), which receives the sk as part of its normal
functionality. So we make sure to plumb state->sk through the various
route_me_harder functions, and then make correct use of it following the
example of __ip_queue_xmit().
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-10-29 10:56:06 +08:00
|
|
|
int ip_route_me_harder(struct net *net, struct sock *sk, struct sk_buff *skb, unsigned int addr_type)
|
2005-08-10 10:39:00 +08:00
|
|
|
{
|
2007-10-15 15:53:15 +08:00
|
|
|
const struct iphdr *iph = ip_hdr(skb);
|
2005-08-10 10:39:00 +08:00
|
|
|
struct rtable *rt;
|
2011-03-12 14:12:47 +08:00
|
|
|
struct flowi4 fl4 = {};
|
2011-06-18 15:53:59 +08:00
|
|
|
__be32 saddr = iph->saddr;
|
netfilter: use actual socket sk rather than skb sk when routing harder
If netfilter changes the packet mark when mangling, the packet is
rerouted using the route_me_harder set of functions. Prior to this
commit, there's one big difference between route_me_harder and the
ordinary initial routing functions, described in the comment above
__ip_queue_xmit():
/* Note: skb->sk can be different from sk, in case of tunnels */
int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,
That function goes on to correctly make use of sk->sk_bound_dev_if,
rather than skb->sk->sk_bound_dev_if. And indeed the comment is true: a
tunnel will receive a packet in ndo_start_xmit with an initial skb->sk.
It will make some transformations to that packet, and then it will send
the encapsulated packet out of a *new* socket. That new socket will
basically always have a different sk_bound_dev_if (otherwise there'd be
a routing loop). So for the purposes of routing the encapsulated packet,
the routing information as it pertains to the socket should come from
that socket's sk, rather than the packet's original skb->sk. For that
reason __ip_queue_xmit() and related functions all do the right thing.
One might argue that all tunnels should just call skb_orphan(skb) before
transmitting the encapsulated packet into the new socket. But tunnels do
*not* do this -- and this is wisely avoided in skb_scrub_packet() too --
because features like TSQ rely on skb->destructor() being called when
that buffer space is truely available again. Calling skb_orphan(skb) too
early would result in buffers filling up unnecessarily and accounting
info being all wrong. Instead, additional routing must take into account
the new sk, just as __ip_queue_xmit() notes.
So, this commit addresses the problem by fishing the correct sk out of
state->sk -- it's already set properly in the call to nf_hook() in
__ip_local_out(), which receives the sk as part of its normal
functionality. So we make sure to plumb state->sk through the various
route_me_harder functions, and then make correct use of it following the
example of __ip_queue_xmit().
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-10-29 10:56:06 +08:00
|
|
|
__u8 flags;
|
2016-11-10 02:24:40 +08:00
|
|
|
struct net_device *dev = skb_dst(skb)->dev;
|
2005-08-10 10:39:00 +08:00
|
|
|
unsigned int hh_len;
|
|
|
|
|
|
netfilter: use actual socket sk rather than skb sk when routing harder
If netfilter changes the packet mark when mangling, the packet is
rerouted using the route_me_harder set of functions. Prior to this
commit, there's one big difference between route_me_harder and the
ordinary initial routing functions, described in the comment above
__ip_queue_xmit():
/* Note: skb->sk can be different from sk, in case of tunnels */
int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,
That function goes on to correctly make use of sk->sk_bound_dev_if,
rather than skb->sk->sk_bound_dev_if. And indeed the comment is true: a
tunnel will receive a packet in ndo_start_xmit with an initial skb->sk.
It will make some transformations to that packet, and then it will send
the encapsulated packet out of a *new* socket. That new socket will
basically always have a different sk_bound_dev_if (otherwise there'd be
a routing loop). So for the purposes of routing the encapsulated packet,
the routing information as it pertains to the socket should come from
that socket's sk, rather than the packet's original skb->sk. For that
reason __ip_queue_xmit() and related functions all do the right thing.
One might argue that all tunnels should just call skb_orphan(skb) before
transmitting the encapsulated packet into the new socket. But tunnels do
*not* do this -- and this is wisely avoided in skb_scrub_packet() too --
because features like TSQ rely on skb->destructor() being called when
that buffer space is truely available again. Calling skb_orphan(skb) too
early would result in buffers filling up unnecessarily and accounting
info being all wrong. Instead, additional routing must take into account
the new sk, just as __ip_queue_xmit() notes.
So, this commit addresses the problem by fishing the correct sk out of
state->sk -- it's already set properly in the call to nf_hook() in
__ip_local_out(), which receives the sk as part of its normal
functionality. So we make sure to plumb state->sk through the various
route_me_harder functions, and then make correct use of it following the
example of __ip_queue_xmit().
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2020-10-29 10:56:06 +08:00
|
|
|
sk = sk_to_full_sk(sk);
|
|
|
|
|
flags = sk ? inet_sk_flowi_flags(sk) : 0;
|
|
|
|
|
|
2011-08-07 17:11:00 +08:00
|
|
|
if (addr_type == RTN_UNSPEC)
|
2016-11-10 02:24:40 +08:00
|
|
|
addr_type = inet_addr_type_dev_table(net, dev, saddr);
|
2011-08-07 17:11:00 +08:00
|
|
|
if (addr_type == RTN_LOCAL || addr_type == RTN_UNICAST)
|
|
|
|
|
flags |= FLOWI_FLAG_ANYSRC;
|
|
|
|
|
else
|
|
|
|
|
saddr = 0;
|
2006-10-03 07:11:13 +08:00
|
|
|
|
2005-08-10 10:39:00 +08:00
|
|
|
/* some non-standard hacks like ipt_REJECT.c:send_reset() can cause
|
2007-11-20 10:53:30 +08:00
|
|
|
* packets with foreign saddr to appear on the NF_INET_LOCAL_OUT hook.
|
2005-08-10 10:39:00 +08:00
|
|
|
*/
|
2011-06-18 15:53:59 +08:00
|
|
|
fl4.daddr = iph->daddr;
|
|
|
|
|
fl4.saddr = saddr;
|
|
|
|
|
fl4.flowi4_tos = RT_TOS(iph->tos);
|
2017-02-17 15:39:28 +08:00
|
|
|
fl4.flowi4_oif = sk ? sk->sk_bound_dev_if : 0;
|
2016-11-10 02:24:40 +08:00
|
|
|
if (!fl4.flowi4_oif)
|
|
|
|
|
fl4.flowi4_oif = l3mdev_master_ifindex(dev);
|
2011-06-18 15:53:59 +08:00
|
|
|
fl4.flowi4_mark = skb->mark;
|
2011-08-07 17:11:00 +08:00
|
|
|
fl4.flowi4_flags = flags;
|
2011-06-18 15:53:59 +08:00
|
|
|
rt = ip_route_output_key(net, &fl4);
|
|
|
|
|
if (IS_ERR(rt))
|
2013-04-05 14:41:10 +08:00
|
|
|
return PTR_ERR(rt);
|
2005-08-10 10:39:00 +08:00
|
|
|
|
2011-06-18 15:53:59 +08:00
|
|
|
/* Drop old route. */
|
|
|
|
|
skb_dst_drop(skb);
|
|
|
|
|
skb_dst_set(skb, &rt->dst);
|
2007-02-09 22:24:47 +08:00
|
|
|
|
2009-06-02 13:19:30 +08:00
|
|
|
if (skb_dst(skb)->error)
|
2013-04-05 14:41:10 +08:00
|
|
|
return skb_dst(skb)->error;
|
2005-08-10 10:39:00 +08:00
|
|
|
|
2006-01-07 15:04:54 +08:00
|
|
|
#ifdef CONFIG_XFRM
|
2007-10-15 15:53:15 +08:00
|
|
|
if (!(IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) &&
|
2011-03-12 14:12:47 +08:00
|
|
|
xfrm_decode_session(skb, flowi4_to_flowi(&fl4), AF_INET) == 0) {
|
2009-06-02 13:19:30 +08:00
|
|
|
struct dst_entry *dst = skb_dst(skb);
|
|
|
|
|
skb_dst_set(skb, NULL);
|
2017-02-17 15:39:28 +08:00
|
|
|
dst = xfrm_lookup(net, dst, flowi4_to_flowi(&fl4), sk, 0);
|
2011-03-03 05:27:41 +08:00
|
|
|
if (IS_ERR(dst))
|
2014-01-16 00:12:50 +08:00
|
|
|
return PTR_ERR(dst);
|
2009-06-02 13:19:30 +08:00
|
|
|
skb_dst_set(skb, dst);
|
|
|
|
|
}
|
2006-01-07 15:04:54 +08:00
|
|
|
#endif
|
|
|
|
|
|
2005-08-10 10:39:00 +08:00
|
|
|
/* Change in oif may mean change in hh_len. */
|
2009-06-02 13:19:30 +08:00
|
|
|
hh_len = skb_dst(skb)->dev->hard_header_len;
|
2007-10-15 15:53:15 +08:00
|
|
|
if (skb_headroom(skb) < hh_len &&
|
2011-11-14 19:00:54 +08:00
|
|
|
pskb_expand_head(skb, HH_DATA_ALIGN(hh_len - skb_headroom(skb)),
|
|
|
|
|
0, GFP_ATOMIC))
|
2013-04-05 14:41:10 +08:00
|
|
|
return -ENOMEM;
|
2005-08-10 10:39:00 +08:00
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
EXPORT_SYMBOL(ip_route_me_harder);
|
2005-08-10 10:42:34 +08:00
|
|
|
|
2017-11-28 05:29:52 +08:00
|
|
|
int nf_ip_route(struct net *net, struct dst_entry **dst, struct flowi *fl,
|
|
|
|
|
bool strict __always_unused)
|
2007-12-05 17:22:05 +08:00
|
|
|
{
|
2011-04-04 22:56:29 +08:00
|
|
|
struct rtable *rt = ip_route_output_key(net, &fl->u.ip4);
|
2011-03-03 06:31:35 +08:00
|
|
|
if (IS_ERR(rt))
|
|
|
|
|
return PTR_ERR(rt);
|
|
|
|
|
*dst = &rt->dst;
|
|
|
|
|
return 0;
|
2007-12-05 17:22:05 +08:00
|
|
|
}
|
2017-11-28 05:29:52 +08:00
|
|
|
EXPORT_SYMBOL_GPL(nf_ip_route);
|