lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

netfilter: nf_conntrack: extend with extra stat counter

Browse Source 
I suspect an unfortunatly series of events occuring under a DDoS
attack, in function __nf_conntrack_find() nf_contrack_core.c.

Adding a stats counter to see if the search is restarted too often.

Signed-off-by: Jesper Dangaard Brouer <hawk@comx.dk>
Signed-off-by: Patrick McHardy <kaber@trash.net>
This commit is contained in:
Jesper Dangaard Brouer
2010-04-23 12:34:56 +02:00
committed by Patrick McHardy
parent cecc74de25
commit af740b2c8f
4 changed files with 12 additions and 7 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
include/linux/netfilter/nf_conntrack_common.h
View File

@@ -113,6 +113,7 @@ struct ip_conntrack_stat {
unsigned int expect_new; unsigned int expect_new;
unsigned int expect_create; unsigned int expect_create;
unsigned int expect_delete; unsigned int expect_delete;
unsigned int search_restart;
}; };
/* call to create an explicit dependency on nf_conntrack. */ /* call to create an explicit dependency on nf_conntrack. */

7
net/ipv4/netfilter/nf_conntrack_l3proto_ipv4_compat.c
View File

@@ -336,12 +336,12 @@ static int ct_cpu_seq_show(struct seq_file *seq, void *v)
const struct ip_conntrack_stat *st = v; const struct ip_conntrack_stat *st = v;
if (v == SEQ_START_TOKEN) { if (v == SEQ_START_TOKEN) {
seq_printf(seq, "entries searched found new invalid ignore delete delete_list insert insert_failed drop early_drop icmp_error expect_new expect_create expect_delete\n"); seq_printf(seq, "entries searched found new invalid ignore delete delete_list insert insert_failed drop early_drop icmp_error expect_new expect_create expect_delete search_restart\n");
return 0; return 0;
} }
seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x %08x " seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x %08x "
"%08x %08x %08x %08x %08x %08x %08x %08x \n", "%08x %08x %08x %08x %08x %08x %08x %08x %08x\n",
nr_conntracks, nr_conntracks,
st->searched, st->searched,
st->found, st->found,
@@ -358,7 +358,8 @@ static int ct_cpu_seq_show(struct seq_file *seq, void *v)
st->expect_new, st->expect_new,
st->expect_create, st->expect_create,
st->expect_delete st->expect_delete,
st->search_restart
); );
return 0; return 0;
} }

4
net/netfilter/nf_conntrack_core.c
View File

@@ -319,8 +319,10 @@ begin:
* not the expected one, we must restart lookup. * not the expected one, we must restart lookup.
* We probably met an item that was moved to another chain. * We probably met an item that was moved to another chain.
*/ */
if (get_nulls_value(n) != hash) if (get_nulls_value(n) != hash) {
NF_CT_STAT_INC(net, search_restart);
goto begin; goto begin;
}
local_bh_enable(); local_bh_enable();
return NULL; return NULL;

7
net/netfilter/nf_conntrack_standalone.c
View File

@@ -252,12 +252,12 @@ static int ct_cpu_seq_show(struct seq_file *seq, void *v)
const struct ip_conntrack_stat *st = v; const struct ip_conntrack_stat *st = v;
if (v == SEQ_START_TOKEN) { if (v == SEQ_START_TOKEN) {
seq_printf(seq, "entries searched found new invalid ignore delete delete_list insert insert_failed drop early_drop icmp_error expect_new expect_create expect_delete\n"); seq_printf(seq, "entries searched found new invalid ignore delete delete_list insert insert_failed drop early_drop icmp_error expect_new expect_create expect_delete search_restart\n");
return 0; return 0;
} }
seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x %08x " seq_printf(seq, "%08x %08x %08x %08x %08x %08x %08x %08x "
"%08x %08x %08x %08x %08x %08x %08x %08x \n", "%08x %08x %08x %08x %08x %08x %08x %08x %08x\n",
nr_conntracks, nr_conntracks,
st->searched, st->searched,
st->found, st->found,
@@ -274,7 +274,8 @@ static int ct_cpu_seq_show(struct seq_file *seq, void *v)
st->expect_new, st->expect_new,
st->expect_create, st->expect_create,
st->expect_delete st->expect_delete,
st->search_restart
); );
return 0; return 0;
} }