linux/net/ipv4/netfilter.c

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/*
* IPv4 specific functions of netfilter core
*
* Rusty Russell (C) 2000 -- This code is GPL.
* Patrick McHardy (C) 2006-2012
*/
#include <linux/kernel.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv4.h>
#include <linux/ip.h>
#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 09:04:11 +01:00
#include <linux/gfp.h>
#include <linux/export.h>
#include <net/route.h>
#include <net/xfrm.h>
#include <net/ip.h>
#include <net/netfilter/nf_queue.h>
/* route_me_harder function, used by iptable_nat, iptable_mangle + ip_queue */
int ip_route_me_harder(struct net *net, struct sk_buff *skb, unsigned int addr_type)
{
const struct iphdr *iph = ip_hdr(skb);
struct rtable *rt;
struct flowi4 fl4 = {};
__be32 saddr = iph->saddr;
const struct sock *sk = skb_to_full_sk(skb);
__u8 flags = sk ? inet_sk_flowi_flags(sk) : 0;
netfilter: Update ip_route_me_harder to consider L3 domain ip_route_me_harder is not considering the L3 domain and sending lookups to the wrong table. For example consider the following output rule: iptables -I OUTPUT -p tcp --dport 12345 -j REJECT --reject-with tcp-reset using perf to analyze lookups via the fib_table_lookup tracepoint shows: vrf-test 1187 [001] 46887.295927: fib:fib_table_lookup: table 255 oif 0 iif 0 src 0.0.0.0 dst 10.100.1.254 tos 0 scope 0 flags 0 ffffffff8143922c perf_trace_fib_table_lookup ([kernel.kallsyms]) ffffffff81493aac fib_table_lookup ([kernel.kallsyms]) ffffffff8148dda3 __inet_dev_addr_type ([kernel.kallsyms]) ffffffff8148ddf6 inet_addr_type ([kernel.kallsyms]) ffffffff8149e344 ip_route_me_harder ([kernel.kallsyms]) and vrf-test 1187 [001] 46887.295933: fib:fib_table_lookup: table 255 oif 0 iif 1 src 10.100.1.254 dst 10.100.1.2 tos 0 scope 0 flags ffffffff8143922c perf_trace_fib_table_lookup ([kernel.kallsyms]) ffffffff81493aac fib_table_lookup ([kernel.kallsyms]) ffffffff814998ff fib4_rule_action ([kernel.kallsyms]) ffffffff81437f35 fib_rules_lookup ([kernel.kallsyms]) ffffffff81499758 __fib_lookup ([kernel.kallsyms]) ffffffff8144f010 fib_lookup.constprop.34 ([kernel.kallsyms]) ffffffff8144f759 __ip_route_output_key_hash ([kernel.kallsyms]) ffffffff8144fc6a ip_route_output_flow ([kernel.kallsyms]) ffffffff8149e39b ip_route_me_harder ([kernel.kallsyms]) In both cases the lookups are directed to table 255 rather than the table associated with the device via the L3 domain. Update both lookups to pull the L3 domain from the dst currently attached to the skb. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-11-09 19:24:40 +01:00
struct net_device *dev = skb_dst(skb)->dev;
unsigned int hh_len;
if (addr_type == RTN_UNSPEC)
netfilter: Update ip_route_me_harder to consider L3 domain ip_route_me_harder is not considering the L3 domain and sending lookups to the wrong table. For example consider the following output rule: iptables -I OUTPUT -p tcp --dport 12345 -j REJECT --reject-with tcp-reset using perf to analyze lookups via the fib_table_lookup tracepoint shows: vrf-test 1187 [001] 46887.295927: fib:fib_table_lookup: table 255 oif 0 iif 0 src 0.0.0.0 dst 10.100.1.254 tos 0 scope 0 flags 0 ffffffff8143922c perf_trace_fib_table_lookup ([kernel.kallsyms]) ffffffff81493aac fib_table_lookup ([kernel.kallsyms]) ffffffff8148dda3 __inet_dev_addr_type ([kernel.kallsyms]) ffffffff8148ddf6 inet_addr_type ([kernel.kallsyms]) ffffffff8149e344 ip_route_me_harder ([kernel.kallsyms]) and vrf-test 1187 [001] 46887.295933: fib:fib_table_lookup: table 255 oif 0 iif 1 src 10.100.1.254 dst 10.100.1.2 tos 0 scope 0 flags ffffffff8143922c perf_trace_fib_table_lookup ([kernel.kallsyms]) ffffffff81493aac fib_table_lookup ([kernel.kallsyms]) ffffffff814998ff fib4_rule_action ([kernel.kallsyms]) ffffffff81437f35 fib_rules_lookup ([kernel.kallsyms]) ffffffff81499758 __fib_lookup ([kernel.kallsyms]) ffffffff8144f010 fib_lookup.constprop.34 ([kernel.kallsyms]) ffffffff8144f759 __ip_route_output_key_hash ([kernel.kallsyms]) ffffffff8144fc6a ip_route_output_flow ([kernel.kallsyms]) ffffffff8149e39b ip_route_me_harder ([kernel.kallsyms]) In both cases the lookups are directed to table 255 rather than the table associated with the device via the L3 domain. Update both lookups to pull the L3 domain from the dst currently attached to the skb. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-11-09 19:24:40 +01:00
addr_type = inet_addr_type_dev_table(net, dev, saddr);
if (addr_type == RTN_LOCAL || addr_type == RTN_UNICAST)
flags |= FLOWI_FLAG_ANYSRC;
else
saddr = 0;
/* some non-standard hacks like ipt_REJECT.c:send_reset() can cause
* packets with foreign saddr to appear on the NF_INET_LOCAL_OUT hook.
*/
fl4.daddr = iph->daddr;
fl4.saddr = saddr;
fl4.flowi4_tos = RT_TOS(iph->tos);
fl4.flowi4_oif = sk ? sk->sk_bound_dev_if : 0;
netfilter: Update ip_route_me_harder to consider L3 domain ip_route_me_harder is not considering the L3 domain and sending lookups to the wrong table. For example consider the following output rule: iptables -I OUTPUT -p tcp --dport 12345 -j REJECT --reject-with tcp-reset using perf to analyze lookups via the fib_table_lookup tracepoint shows: vrf-test 1187 [001] 46887.295927: fib:fib_table_lookup: table 255 oif 0 iif 0 src 0.0.0.0 dst 10.100.1.254 tos 0 scope 0 flags 0 ffffffff8143922c perf_trace_fib_table_lookup ([kernel.kallsyms]) ffffffff81493aac fib_table_lookup ([kernel.kallsyms]) ffffffff8148dda3 __inet_dev_addr_type ([kernel.kallsyms]) ffffffff8148ddf6 inet_addr_type ([kernel.kallsyms]) ffffffff8149e344 ip_route_me_harder ([kernel.kallsyms]) and vrf-test 1187 [001] 46887.295933: fib:fib_table_lookup: table 255 oif 0 iif 1 src 10.100.1.254 dst 10.100.1.2 tos 0 scope 0 flags ffffffff8143922c perf_trace_fib_table_lookup ([kernel.kallsyms]) ffffffff81493aac fib_table_lookup ([kernel.kallsyms]) ffffffff814998ff fib4_rule_action ([kernel.kallsyms]) ffffffff81437f35 fib_rules_lookup ([kernel.kallsyms]) ffffffff81499758 __fib_lookup ([kernel.kallsyms]) ffffffff8144f010 fib_lookup.constprop.34 ([kernel.kallsyms]) ffffffff8144f759 __ip_route_output_key_hash ([kernel.kallsyms]) ffffffff8144fc6a ip_route_output_flow ([kernel.kallsyms]) ffffffff8149e39b ip_route_me_harder ([kernel.kallsyms]) In both cases the lookups are directed to table 255 rather than the table associated with the device via the L3 domain. Update both lookups to pull the L3 domain from the dst currently attached to the skb. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2016-11-09 19:24:40 +01:00
if (!fl4.flowi4_oif)
fl4.flowi4_oif = l3mdev_master_ifindex(dev);
fl4.flowi4_mark = skb->mark;
fl4.flowi4_flags = flags;
rt = ip_route_output_key(net, &fl4);
if (IS_ERR(rt))
return PTR_ERR(rt);
/* Drop old route. */
skb_dst_drop(skb);
skb_dst_set(skb, &rt->dst);
if (skb_dst(skb)->error)
return skb_dst(skb)->error;
#ifdef CONFIG_XFRM
if (!(IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) &&
xfrm_decode_session(skb, flowi4_to_flowi(&fl4), AF_INET) == 0) {
struct dst_entry *dst = skb_dst(skb);
skb_dst_set(skb, NULL);
dst = xfrm_lookup(net, dst, flowi4_to_flowi(&fl4), sk, 0);
if (IS_ERR(dst))
return PTR_ERR(dst);
skb_dst_set(skb, dst);
}
#endif
/* Change in oif may mean change in hh_len. */
hh_len = skb_dst(skb)->dev->hard_header_len;
if (skb_headroom(skb) < hh_len &&
pskb_expand_head(skb, HH_DATA_ALIGN(hh_len - skb_headroom(skb)),
0, GFP_ATOMIC))
return -ENOMEM;
return 0;
}
EXPORT_SYMBOL(ip_route_me_harder);
/*
* Extra routing may needed on local out, as the QUEUE target never
* returns control to the table.
*/
struct ip_rt_info {
__be32 daddr;
__be32 saddr;
u_int8_t tos;
u_int32_t mark;
};
static void nf_ip_saveroute(const struct sk_buff *skb,
struct nf_queue_entry *entry)
{
struct ip_rt_info *rt_info = nf_queue_entry_reroute(entry);
if (entry->state.hook == NF_INET_LOCAL_OUT) {
const struct iphdr *iph = ip_hdr(skb);
rt_info->tos = iph->tos;
rt_info->daddr = iph->daddr;
rt_info->saddr = iph->saddr;
rt_info->mark = skb->mark;
}
}
static int nf_ip_reroute(struct net *net, struct sk_buff *skb,
const struct nf_queue_entry *entry)
{
const struct ip_rt_info *rt_info = nf_queue_entry_reroute(entry);
if (entry->state.hook == NF_INET_LOCAL_OUT) {
const struct iphdr *iph = ip_hdr(skb);
if (!(iph->tos == rt_info->tos &&
skb->mark == rt_info->mark &&
iph->daddr == rt_info->daddr &&
iph->saddr == rt_info->saddr))
return ip_route_me_harder(net, skb, RTN_UNSPEC);
}
return 0;
}
__sum16 nf_ip_checksum(struct sk_buff *skb, unsigned int hook,
unsigned int dataoff, u_int8_t protocol)
{
const struct iphdr *iph = ip_hdr(skb);
__sum16 csum = 0;
switch (skb->ip_summed) {
case CHECKSUM_COMPLETE:
if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN)
break;
if ((protocol == 0 && !csum_fold(skb->csum)) ||
!csum_tcpudp_magic(iph->saddr, iph->daddr,
skb->len - dataoff, protocol,
skb->csum)) {
skb->ip_summed = CHECKSUM_UNNECESSARY;
break;
}
/* fall through */
case CHECKSUM_NONE:
if (protocol == 0)
skb->csum = 0;
else
skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
skb->len - dataoff,
protocol, 0);
csum = __skb_checksum_complete(skb);
}
return csum;
}
EXPORT_SYMBOL(nf_ip_checksum);
static __sum16 nf_ip_checksum_partial(struct sk_buff *skb, unsigned int hook,
unsigned int dataoff, unsigned int len,
u_int8_t protocol)
{
const struct iphdr *iph = ip_hdr(skb);
__sum16 csum = 0;
switch (skb->ip_summed) {
case CHECKSUM_COMPLETE:
if (len == skb->len - dataoff)
return nf_ip_checksum(skb, hook, dataoff, protocol);
/* fall through */
case CHECKSUM_NONE:
skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr, protocol,
skb->len - dataoff, 0);
skb->ip_summed = CHECKSUM_NONE;
return __skb_checksum_complete_head(skb, dataoff + len);
}
return csum;
}
static int nf_ip_route(struct net *net, struct dst_entry **dst,
struct flowi *fl, bool strict __always_unused)
{
struct rtable *rt = ip_route_output_key(net, &fl->u.ip4);
if (IS_ERR(rt))
return PTR_ERR(rt);
*dst = &rt->dst;
return 0;
}
static const struct nf_afinfo nf_ip_afinfo = {
.family = AF_INET,
.checksum = nf_ip_checksum,
.checksum_partial = nf_ip_checksum_partial,
.route = nf_ip_route,
.saveroute = nf_ip_saveroute,
.reroute = nf_ip_reroute,
.route_key_size = sizeof(struct ip_rt_info),
};
static int __init ipv4_netfilter_init(void)
{
return nf_register_afinfo(&nf_ip_afinfo);
}
netfilter: don't use module_init/exit in core IPV4 code The file net/ipv4/netfilter.o is created based on whether CONFIG_NETFILTER is set. However that is defined as a bool, and hence this file with the core netfilter hooks will never be modular. So using module_init as an alias for __initcall can be somewhat misleading. Fix this up now, so that we can relocate module_init from init.h into module.h in the future. If we don't do this, we'd have to add module.h to obviously non-modular code, and that would be a worse thing. Also add an inclusion of init.h, as that was previously implicit here in the netfilter.c file. Note that direct use of __initcall is discouraged, vs. one of the priority categorized subgroups. As __initcall gets mapped onto device_initcall, our use of subsys_initcall (which seems to make sense for netfilter code) will thus change this registration from level 6-device to level 4-subsys (i.e. slightly earlier). However no observable impact of that small difference has been observed during testing, or is expected. (i.e. the location of the netfilter messages in dmesg remains unchanged with respect to all the other surrounding messages.) As for the module_exit, rather than replace it with __exitcall, we simply remove it, since it appears only UML does anything with those, and even for UML, there is no relevant cleanup to be done here. Cc: Pablo Neira Ayuso <pablo@netfilter.org> Acked-by: Pablo Neira Ayuso <pablo@netfilter.org> Cc: Patrick McHardy <kaber@trash.net> Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Cc: "David S. Miller" <davem@davemloft.net> Cc: netfilter-devel@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2015-05-02 02:08:20 +02:00
subsys_initcall(ipv4_netfilter_init);