summaryrefslogtreecommitdiff
path: root/net/netfilter/nf_conntrack_core.c
diff options
context:
space:
mode:
authorMarcel Ziswiler <marcel.ziswiler@toradex.com>2020-05-21 00:54:36 +0200
committerMarcel Ziswiler <marcel.ziswiler@toradex.com>2020-05-21 00:54:36 +0200
commit135d39dcedcedd1f44ea0bba52f15ac5922c114f (patch)
tree12379fc8ef7489eaca1c7245f8bd6af74c619a8f /net/netfilter/nf_conntrack_core.c
parent187764bd111b27783b6d68ffb3b3dbb3a9bafd38 (diff)
parent1279cd128bba968ebe0a2df7f7ae38bae90250ef (diff)
Merge remote-tracking branch 'remotes/fslc/4.9-2.3.x-imx' into toradex_4.9-2.3.x-imx-next
Conflicts: sound/soc/codecs/sgtl5000.c sound/soc/fsl/imx-sgtl5000.c
Diffstat (limited to 'net/netfilter/nf_conntrack_core.c')
-rw-r--r--net/netfilter/nf_conntrack_core.c35
1 files changed, 35 insertions, 0 deletions
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index df1d5618b008..1bdae8f188e1 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -25,6 +25,7 @@
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/jhash.h>
+#include <linux/siphash.h>
#include <linux/err.h>
#include <linux/percpu.h>
#include <linux/moduleparam.h>
@@ -301,6 +302,40 @@ nf_ct_invert_tuple(struct nf_conntrack_tuple *inverse,
}
EXPORT_SYMBOL_GPL(nf_ct_invert_tuple);
+/* Generate a almost-unique pseudo-id for a given conntrack.
+ *
+ * intentionally doesn't re-use any of the seeds used for hash
+ * table location, we assume id gets exposed to userspace.
+ *
+ * Following nf_conn items do not change throughout lifetime
+ * of the nf_conn:
+ *
+ * 1. nf_conn address
+ * 2. nf_conn->master address (normally NULL)
+ * 3. the associated net namespace
+ * 4. the original direction tuple
+ */
+u32 nf_ct_get_id(const struct nf_conn *ct)
+{
+ static __read_mostly siphash_key_t ct_id_seed;
+ unsigned long a, b, c, d;
+
+ net_get_random_once(&ct_id_seed, sizeof(ct_id_seed));
+
+ a = (unsigned long)ct;
+ b = (unsigned long)ct->master;
+ c = (unsigned long)nf_ct_net(ct);
+ d = (unsigned long)siphash(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
+ sizeof(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple),
+ &ct_id_seed);
+#ifdef CONFIG_64BIT
+ return siphash_4u64((u64)a, (u64)b, (u64)c, (u64)d, &ct_id_seed);
+#else
+ return siphash_4u32((u32)a, (u32)b, (u32)c, (u32)d, &ct_id_seed);
+#endif
+}
+EXPORT_SYMBOL_GPL(nf_ct_get_id);
+
static void
clean_from_lists(struct nf_conn *ct)
{