2007-02-07 23:09:46 +00:00
|
|
|
/*
|
|
|
|
* This is a module which is used for setting the MSS option in TCP packets.
|
|
|
|
*
|
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* Copyright (C) 2000 Marc Boucher <marc@mbsi.ca>
|
2013-04-06 13:24:29 +00:00
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* Copyright (C) 2007 Patrick McHardy <kaber@trash.net>
|
2007-02-07 23:09:46 +00:00
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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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*/
|
2010-03-17 15:04:40 +00:00
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
|
2007-02-07 23:09:46 +00:00
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/ip.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 08:04:11 +00:00
|
|
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#include <linux/gfp.h>
|
2007-02-07 23:09:46 +00:00
|
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#include <linux/ipv6.h>
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#include <linux/tcp.h>
|
2008-01-31 12:06:10 +00:00
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|
#include <net/dst.h>
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|
|
#include <net/flow.h>
|
2007-02-07 23:09:46 +00:00
|
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#include <net/ipv6.h>
|
2008-01-31 12:06:10 +00:00
|
|
|
#include <net/route.h>
|
2007-02-07 23:09:46 +00:00
|
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|
#include <net/tcp.h>
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#include <linux/netfilter_ipv4/ip_tables.h>
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#include <linux/netfilter_ipv6/ip6_tables.h>
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|
#include <linux/netfilter/x_tables.h>
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#include <linux/netfilter/xt_tcpudp.h>
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#include <linux/netfilter/xt_TCPMSS.h>
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>");
|
2008-01-15 07:42:28 +00:00
|
|
|
MODULE_DESCRIPTION("Xtables: TCP Maximum Segment Size (MSS) adjustment");
|
2007-02-07 23:09:46 +00:00
|
|
|
MODULE_ALIAS("ipt_TCPMSS");
|
|
|
|
MODULE_ALIAS("ip6t_TCPMSS");
|
|
|
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|
static inline unsigned int
|
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|
|
optlen(const u_int8_t *opt, unsigned int offset)
|
|
|
|
{
|
|
|
|
/* Beware zero-length options: make finite progress */
|
|
|
|
if (opt[offset] <= TCPOPT_NOP || opt[offset+1] == 0)
|
|
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|
return 1;
|
|
|
|
else
|
|
|
|
return opt[offset+1];
|
|
|
|
}
|
|
|
|
|
2013-09-26 07:00:31 +00:00
|
|
|
static u_int32_t tcpmss_reverse_mtu(struct net *net,
|
|
|
|
const struct sk_buff *skb,
|
2013-09-26 07:00:30 +00:00
|
|
|
unsigned int family)
|
|
|
|
{
|
|
|
|
struct flowi fl;
|
|
|
|
const struct nf_afinfo *ai;
|
|
|
|
struct rtable *rt = NULL;
|
|
|
|
u_int32_t mtu = ~0U;
|
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|
|
|
|
if (family == PF_INET) {
|
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|
|
struct flowi4 *fl4 = &fl.u.ip4;
|
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|
|
memset(fl4, 0, sizeof(*fl4));
|
|
|
|
fl4->daddr = ip_hdr(skb)->saddr;
|
|
|
|
} else {
|
|
|
|
struct flowi6 *fl6 = &fl.u.ip6;
|
|
|
|
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|
|
memset(fl6, 0, sizeof(*fl6));
|
|
|
|
fl6->daddr = ipv6_hdr(skb)->saddr;
|
|
|
|
}
|
|
|
|
rcu_read_lock();
|
|
|
|
ai = nf_get_afinfo(family);
|
|
|
|
if (ai != NULL)
|
2013-09-26 07:00:31 +00:00
|
|
|
ai->route(net, (struct dst_entry **)&rt, &fl, false);
|
2013-09-26 07:00:30 +00:00
|
|
|
rcu_read_unlock();
|
|
|
|
|
|
|
|
if (rt != NULL) {
|
|
|
|
mtu = dst_mtu(&rt->dst);
|
|
|
|
dst_release(&rt->dst);
|
|
|
|
}
|
|
|
|
return mtu;
|
|
|
|
}
|
|
|
|
|
2007-02-07 23:09:46 +00:00
|
|
|
static int
|
2007-10-15 07:53:15 +00:00
|
|
|
tcpmss_mangle_packet(struct sk_buff *skb,
|
2013-06-12 08:44:51 +00:00
|
|
|
const struct xt_action_param *par,
|
2013-09-26 07:00:30 +00:00
|
|
|
unsigned int family,
|
2007-02-07 23:09:46 +00:00
|
|
|
unsigned int tcphoff,
|
|
|
|
unsigned int minlen)
|
|
|
|
{
|
2013-06-12 08:44:51 +00:00
|
|
|
const struct xt_tcpmss_info *info = par->targinfo;
|
2007-02-07 23:09:46 +00:00
|
|
|
struct tcphdr *tcph;
|
2013-07-25 08:37:49 +00:00
|
|
|
int len, tcp_hdrlen;
|
|
|
|
unsigned int i;
|
2007-02-07 23:09:46 +00:00
|
|
|
__be16 oldval;
|
|
|
|
u16 newmss;
|
|
|
|
u8 *opt;
|
|
|
|
|
2013-06-12 08:58:20 +00:00
|
|
|
/* This is a fragment, no TCP header is available */
|
|
|
|
if (par->fragoff != 0)
|
2013-09-01 15:32:21 +00:00
|
|
|
return 0;
|
2013-06-12 08:58:20 +00:00
|
|
|
|
2007-10-15 07:53:15 +00:00
|
|
|
if (!skb_make_writable(skb, skb->len))
|
2007-02-07 23:09:46 +00:00
|
|
|
return -1;
|
|
|
|
|
2013-07-25 08:37:49 +00:00
|
|
|
len = skb->len - tcphoff;
|
|
|
|
if (len < (int)sizeof(struct tcphdr))
|
|
|
|
return -1;
|
|
|
|
|
2007-10-15 07:53:15 +00:00
|
|
|
tcph = (struct tcphdr *)(skb_network_header(skb) + tcphoff);
|
2013-07-25 08:37:49 +00:00
|
|
|
tcp_hdrlen = tcph->doff * 4;
|
2007-02-07 23:09:46 +00:00
|
|
|
|
2013-07-25 08:37:49 +00:00
|
|
|
if (len < tcp_hdrlen)
|
2007-02-07 23:09:46 +00:00
|
|
|
return -1;
|
|
|
|
|
|
|
|
if (info->mss == XT_TCPMSS_CLAMP_PMTU) {
|
2015-09-18 19:32:59 +00:00
|
|
|
struct net *net = par->net;
|
2013-09-26 07:00:31 +00:00
|
|
|
unsigned int in_mtu = tcpmss_reverse_mtu(net, skb, family);
|
2013-09-26 07:00:30 +00:00
|
|
|
|
2009-06-02 05:19:30 +00:00
|
|
|
if (dst_mtu(skb_dst(skb)) <= minlen) {
|
2012-05-13 21:56:26 +00:00
|
|
|
net_err_ratelimited("unknown or invalid path-MTU (%u)\n",
|
|
|
|
dst_mtu(skb_dst(skb)));
|
2007-02-07 23:09:46 +00:00
|
|
|
return -1;
|
|
|
|
}
|
2008-01-31 12:06:10 +00:00
|
|
|
if (in_mtu <= minlen) {
|
2012-05-13 21:56:26 +00:00
|
|
|
net_err_ratelimited("unknown or invalid path-MTU (%u)\n",
|
|
|
|
in_mtu);
|
2008-01-31 12:06:10 +00:00
|
|
|
return -1;
|
|
|
|
}
|
2009-06-02 05:19:30 +00:00
|
|
|
newmss = min(dst_mtu(skb_dst(skb)), in_mtu) - minlen;
|
2007-02-07 23:09:46 +00:00
|
|
|
} else
|
|
|
|
newmss = info->mss;
|
|
|
|
|
|
|
|
opt = (u_int8_t *)tcph;
|
2013-07-25 08:37:49 +00:00
|
|
|
for (i = sizeof(struct tcphdr); i <= tcp_hdrlen - TCPOLEN_MSS; i += optlen(opt, i)) {
|
|
|
|
if (opt[i] == TCPOPT_MSS && opt[i+1] == TCPOLEN_MSS) {
|
2007-02-07 23:09:46 +00:00
|
|
|
u_int16_t oldmss;
|
|
|
|
|
|
|
|
oldmss = (opt[i+2] << 8) | opt[i+3];
|
|
|
|
|
2007-12-18 06:27:36 +00:00
|
|
|
/* Never increase MSS, even when setting it, as
|
|
|
|
* doing so results in problems for hosts that rely
|
|
|
|
* on MSS being set correctly.
|
|
|
|
*/
|
|
|
|
if (oldmss <= newmss)
|
2007-02-07 23:09:46 +00:00
|
|
|
return 0;
|
|
|
|
|
|
|
|
opt[i+2] = (newmss & 0xff00) >> 8;
|
2007-07-08 05:19:08 +00:00
|
|
|
opt[i+3] = newmss & 0x00ff;
|
2007-02-07 23:09:46 +00:00
|
|
|
|
2007-11-29 14:17:11 +00:00
|
|
|
inet_proto_csum_replace2(&tcph->check, skb,
|
|
|
|
htons(oldmss), htons(newmss),
|
2015-08-17 20:42:25 +00:00
|
|
|
false);
|
2007-02-07 23:09:46 +00:00
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2010-02-02 14:33:38 +00:00
|
|
|
/* There is data after the header so the option can't be added
|
2013-07-25 08:37:49 +00:00
|
|
|
* without moving it, and doing so may make the SYN packet
|
|
|
|
* itself too large. Accept the packet unmodified instead.
|
|
|
|
*/
|
|
|
|
if (len > tcp_hdrlen)
|
2010-02-02 14:33:38 +00:00
|
|
|
return 0;
|
|
|
|
|
2007-02-07 23:09:46 +00:00
|
|
|
/*
|
|
|
|
* MSS Option not found ?! add it..
|
|
|
|
*/
|
2007-10-15 07:53:15 +00:00
|
|
|
if (skb_tailroom(skb) < TCPOLEN_MSS) {
|
|
|
|
if (pskb_expand_head(skb, 0,
|
|
|
|
TCPOLEN_MSS - skb_tailroom(skb),
|
2007-10-14 07:39:55 +00:00
|
|
|
GFP_ATOMIC))
|
2007-02-07 23:09:46 +00:00
|
|
|
return -1;
|
2007-10-15 07:53:15 +00:00
|
|
|
tcph = (struct tcphdr *)(skb_network_header(skb) + tcphoff);
|
2007-02-07 23:09:46 +00:00
|
|
|
}
|
|
|
|
|
2007-10-15 07:53:15 +00:00
|
|
|
skb_put(skb, TCPOLEN_MSS);
|
2007-02-07 23:09:46 +00:00
|
|
|
|
2013-06-12 08:44:51 +00:00
|
|
|
/*
|
|
|
|
* IPv4: RFC 1122 states "If an MSS option is not received at
|
|
|
|
* connection setup, TCP MUST assume a default send MSS of 536".
|
|
|
|
* IPv6: RFC 2460 states IPv6 has a minimum MTU of 1280 and a minimum
|
|
|
|
* length IPv6 header of 60, ergo the default MSS value is 1220
|
|
|
|
* Since no MSS was provided, we must use the default values
|
2013-06-04 05:09:27 +00:00
|
|
|
*/
|
2013-06-12 08:44:51 +00:00
|
|
|
if (par->family == NFPROTO_IPV4)
|
|
|
|
newmss = min(newmss, (u16)536);
|
|
|
|
else
|
|
|
|
newmss = min(newmss, (u16)1220);
|
2013-06-04 05:09:27 +00:00
|
|
|
|
2007-02-07 23:09:46 +00:00
|
|
|
opt = (u_int8_t *)tcph + sizeof(struct tcphdr);
|
2013-07-25 08:37:49 +00:00
|
|
|
memmove(opt + TCPOLEN_MSS, opt, len - sizeof(struct tcphdr));
|
2007-02-07 23:09:46 +00:00
|
|
|
|
2007-11-29 14:17:11 +00:00
|
|
|
inet_proto_csum_replace2(&tcph->check, skb,
|
2015-08-17 20:42:25 +00:00
|
|
|
htons(len), htons(len + TCPOLEN_MSS), true);
|
2007-02-07 23:09:46 +00:00
|
|
|
opt[0] = TCPOPT_MSS;
|
|
|
|
opt[1] = TCPOLEN_MSS;
|
|
|
|
opt[2] = (newmss & 0xff00) >> 8;
|
2007-07-08 05:19:08 +00:00
|
|
|
opt[3] = newmss & 0x00ff;
|
2007-02-07 23:09:46 +00:00
|
|
|
|
2015-08-17 20:42:25 +00:00
|
|
|
inet_proto_csum_replace4(&tcph->check, skb, 0, *((__be32 *)opt), false);
|
2007-02-07 23:09:46 +00:00
|
|
|
|
|
|
|
oldval = ((__be16 *)tcph)[6];
|
|
|
|
tcph->doff += TCPOLEN_MSS/4;
|
2007-11-29 14:17:11 +00:00
|
|
|
inet_proto_csum_replace2(&tcph->check, skb,
|
2015-08-17 20:42:25 +00:00
|
|
|
oldval, ((__be16 *)tcph)[6], false);
|
2007-02-07 23:09:46 +00:00
|
|
|
return TCPOLEN_MSS;
|
|
|
|
}
|
|
|
|
|
|
|
|
static unsigned int
|
2009-07-05 17:43:26 +00:00
|
|
|
tcpmss_tg4(struct sk_buff *skb, const struct xt_action_param *par)
|
2007-02-07 23:09:46 +00:00
|
|
|
{
|
2007-10-15 07:53:15 +00:00
|
|
|
struct iphdr *iph = ip_hdr(skb);
|
2007-02-07 23:09:46 +00:00
|
|
|
__be16 newlen;
|
|
|
|
int ret;
|
|
|
|
|
2013-06-12 08:44:51 +00:00
|
|
|
ret = tcpmss_mangle_packet(skb, par,
|
2013-09-26 07:00:30 +00:00
|
|
|
PF_INET,
|
2008-01-31 12:06:10 +00:00
|
|
|
iph->ihl * 4,
|
2007-02-07 23:09:46 +00:00
|
|
|
sizeof(*iph) + sizeof(struct tcphdr));
|
|
|
|
if (ret < 0)
|
|
|
|
return NF_DROP;
|
|
|
|
if (ret > 0) {
|
2007-10-15 07:53:15 +00:00
|
|
|
iph = ip_hdr(skb);
|
2007-02-07 23:09:46 +00:00
|
|
|
newlen = htons(ntohs(iph->tot_len) + ret);
|
2007-11-29 14:17:11 +00:00
|
|
|
csum_replace2(&iph->check, iph->tot_len, newlen);
|
2007-02-07 23:09:46 +00:00
|
|
|
iph->tot_len = newlen;
|
|
|
|
}
|
|
|
|
return XT_CONTINUE;
|
|
|
|
}
|
|
|
|
|
2011-12-12 02:58:24 +00:00
|
|
|
#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
|
2007-02-07 23:09:46 +00:00
|
|
|
static unsigned int
|
2009-07-05 17:43:26 +00:00
|
|
|
tcpmss_tg6(struct sk_buff *skb, const struct xt_action_param *par)
|
2007-02-07 23:09:46 +00:00
|
|
|
{
|
2007-10-15 07:53:15 +00:00
|
|
|
struct ipv6hdr *ipv6h = ipv6_hdr(skb);
|
2007-02-07 23:09:46 +00:00
|
|
|
u8 nexthdr;
|
2016-01-15 16:21:32 +00:00
|
|
|
__be16 frag_off, oldlen, newlen;
|
2007-02-07 23:09:46 +00:00
|
|
|
int tcphoff;
|
|
|
|
int ret;
|
|
|
|
|
|
|
|
nexthdr = ipv6h->nexthdr;
|
2011-12-01 01:05:51 +00:00
|
|
|
tcphoff = ipv6_skip_exthdr(skb, sizeof(*ipv6h), &nexthdr, &frag_off);
|
2007-11-30 12:58:03 +00:00
|
|
|
if (tcphoff < 0)
|
2007-02-07 23:09:46 +00:00
|
|
|
return NF_DROP;
|
2013-06-12 08:44:51 +00:00
|
|
|
ret = tcpmss_mangle_packet(skb, par,
|
2013-09-26 07:00:30 +00:00
|
|
|
PF_INET6,
|
2008-01-31 12:06:10 +00:00
|
|
|
tcphoff,
|
2007-02-07 23:09:46 +00:00
|
|
|
sizeof(*ipv6h) + sizeof(struct tcphdr));
|
|
|
|
if (ret < 0)
|
|
|
|
return NF_DROP;
|
|
|
|
if (ret > 0) {
|
2007-10-15 07:53:15 +00:00
|
|
|
ipv6h = ipv6_hdr(skb);
|
2016-01-15 16:21:32 +00:00
|
|
|
oldlen = ipv6h->payload_len;
|
|
|
|
newlen = htons(ntohs(oldlen) + ret);
|
|
|
|
if (skb->ip_summed == CHECKSUM_COMPLETE)
|
|
|
|
skb->csum = csum_add(csum_sub(skb->csum, oldlen),
|
|
|
|
newlen);
|
|
|
|
ipv6h->payload_len = newlen;
|
2007-02-07 23:09:46 +00:00
|
|
|
}
|
|
|
|
return XT_CONTINUE;
|
|
|
|
}
|
|
|
|
#endif
|
|
|
|
|
|
|
|
/* Must specify -p tcp --syn */
|
2007-07-08 05:16:26 +00:00
|
|
|
static inline bool find_syn_match(const struct xt_entry_match *m)
|
2007-02-07 23:09:46 +00:00
|
|
|
{
|
|
|
|
const struct xt_tcp *tcpinfo = (const struct xt_tcp *)m->data;
|
|
|
|
|
|
|
|
if (strcmp(m->u.kernel.match->name, "tcp") == 0 &&
|
2010-06-12 14:01:43 +00:00
|
|
|
tcpinfo->flg_cmp & TCPHDR_SYN &&
|
2007-02-07 23:09:46 +00:00
|
|
|
!(tcpinfo->invflags & XT_TCP_INV_FLAGS))
|
2007-07-08 05:16:26 +00:00
|
|
|
return true;
|
2007-02-07 23:09:46 +00:00
|
|
|
|
2007-07-08 05:16:26 +00:00
|
|
|
return false;
|
2007-02-07 23:09:46 +00:00
|
|
|
}
|
|
|
|
|
2010-03-19 16:16:42 +00:00
|
|
|
static int tcpmss_tg4_check(const struct xt_tgchk_param *par)
|
2007-02-07 23:09:46 +00:00
|
|
|
{
|
2008-10-08 09:35:19 +00:00
|
|
|
const struct xt_tcpmss_info *info = par->targinfo;
|
|
|
|
const struct ipt_entry *e = par->entryinfo;
|
2010-02-24 17:34:48 +00:00
|
|
|
const struct xt_entry_match *ematch;
|
2007-02-07 23:09:46 +00:00
|
|
|
|
|
|
|
if (info->mss == XT_TCPMSS_CLAMP_PMTU &&
|
2008-10-08 09:35:19 +00:00
|
|
|
(par->hook_mask & ~((1 << NF_INET_FORWARD) |
|
2007-11-20 02:53:30 +00:00
|
|
|
(1 << NF_INET_LOCAL_OUT) |
|
|
|
|
(1 << NF_INET_POST_ROUTING))) != 0) {
|
2010-03-17 15:04:40 +00:00
|
|
|
pr_info("path-MTU clamping only supported in "
|
|
|
|
"FORWARD, OUTPUT and POSTROUTING hooks\n");
|
2010-03-25 15:34:45 +00:00
|
|
|
return -EINVAL;
|
2007-02-07 23:09:46 +00:00
|
|
|
}
|
2015-05-14 12:57:23 +00:00
|
|
|
if (par->nft_compat)
|
|
|
|
return 0;
|
|
|
|
|
2010-02-24 17:34:48 +00:00
|
|
|
xt_ematch_foreach(ematch, e)
|
|
|
|
if (find_syn_match(ematch))
|
2010-03-25 15:34:45 +00:00
|
|
|
return 0;
|
2010-03-17 15:04:40 +00:00
|
|
|
pr_info("Only works on TCP SYN packets\n");
|
2010-03-25 15:34:45 +00:00
|
|
|
return -EINVAL;
|
2007-02-07 23:09:46 +00:00
|
|
|
}
|
|
|
|
|
2011-12-12 02:58:24 +00:00
|
|
|
#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
|
2010-03-19 16:16:42 +00:00
|
|
|
static int tcpmss_tg6_check(const struct xt_tgchk_param *par)
|
2007-02-07 23:09:46 +00:00
|
|
|
{
|
2008-10-08 09:35:19 +00:00
|
|
|
const struct xt_tcpmss_info *info = par->targinfo;
|
|
|
|
const struct ip6t_entry *e = par->entryinfo;
|
2010-02-24 17:34:48 +00:00
|
|
|
const struct xt_entry_match *ematch;
|
2007-02-07 23:09:46 +00:00
|
|
|
|
|
|
|
if (info->mss == XT_TCPMSS_CLAMP_PMTU &&
|
2008-10-08 09:35:19 +00:00
|
|
|
(par->hook_mask & ~((1 << NF_INET_FORWARD) |
|
2007-11-20 02:53:30 +00:00
|
|
|
(1 << NF_INET_LOCAL_OUT) |
|
|
|
|
(1 << NF_INET_POST_ROUTING))) != 0) {
|
2010-03-17 15:04:40 +00:00
|
|
|
pr_info("path-MTU clamping only supported in "
|
|
|
|
"FORWARD, OUTPUT and POSTROUTING hooks\n");
|
2010-03-25 15:34:45 +00:00
|
|
|
return -EINVAL;
|
2007-02-07 23:09:46 +00:00
|
|
|
}
|
2015-05-14 12:57:23 +00:00
|
|
|
if (par->nft_compat)
|
|
|
|
return 0;
|
|
|
|
|
2010-02-24 17:34:48 +00:00
|
|
|
xt_ematch_foreach(ematch, e)
|
|
|
|
if (find_syn_match(ematch))
|
2010-03-25 15:34:45 +00:00
|
|
|
return 0;
|
2010-03-17 15:04:40 +00:00
|
|
|
pr_info("Only works on TCP SYN packets\n");
|
2010-03-25 15:34:45 +00:00
|
|
|
return -EINVAL;
|
2007-02-07 23:09:46 +00:00
|
|
|
}
|
|
|
|
#endif
|
|
|
|
|
2007-12-05 07:24:03 +00:00
|
|
|
static struct xt_target tcpmss_tg_reg[] __read_mostly = {
|
2007-02-07 23:09:46 +00:00
|
|
|
{
|
2008-10-08 09:35:01 +00:00
|
|
|
.family = NFPROTO_IPV4,
|
2007-02-07 23:09:46 +00:00
|
|
|
.name = "TCPMSS",
|
2007-12-05 07:24:03 +00:00
|
|
|
.checkentry = tcpmss_tg4_check,
|
|
|
|
.target = tcpmss_tg4,
|
2007-02-07 23:09:46 +00:00
|
|
|
.targetsize = sizeof(struct xt_tcpmss_info),
|
|
|
|
.proto = IPPROTO_TCP,
|
|
|
|
.me = THIS_MODULE,
|
|
|
|
},
|
2011-12-12 02:58:24 +00:00
|
|
|
#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)
|
2007-02-07 23:09:46 +00:00
|
|
|
{
|
2008-10-08 09:35:01 +00:00
|
|
|
.family = NFPROTO_IPV6,
|
2007-02-07 23:09:46 +00:00
|
|
|
.name = "TCPMSS",
|
2007-12-05 07:24:03 +00:00
|
|
|
.checkentry = tcpmss_tg6_check,
|
|
|
|
.target = tcpmss_tg6,
|
2007-02-07 23:09:46 +00:00
|
|
|
.targetsize = sizeof(struct xt_tcpmss_info),
|
|
|
|
.proto = IPPROTO_TCP,
|
|
|
|
.me = THIS_MODULE,
|
|
|
|
},
|
|
|
|
#endif
|
|
|
|
};
|
|
|
|
|
2007-12-05 07:24:03 +00:00
|
|
|
static int __init tcpmss_tg_init(void)
|
2007-02-07 23:09:46 +00:00
|
|
|
{
|
2007-12-05 07:24:03 +00:00
|
|
|
return xt_register_targets(tcpmss_tg_reg, ARRAY_SIZE(tcpmss_tg_reg));
|
2007-02-07 23:09:46 +00:00
|
|
|
}
|
|
|
|
|
2007-12-05 07:24:03 +00:00
|
|
|
static void __exit tcpmss_tg_exit(void)
|
2007-02-07 23:09:46 +00:00
|
|
|
{
|
2007-12-05 07:24:03 +00:00
|
|
|
xt_unregister_targets(tcpmss_tg_reg, ARRAY_SIZE(tcpmss_tg_reg));
|
2007-02-07 23:09:46 +00:00
|
|
|
}
|
|
|
|
|
2007-12-05 07:24:03 +00:00
|
|
|
module_init(tcpmss_tg_init);
|
|
|
|
module_exit(tcpmss_tg_exit);
|