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-rw-r--r--net/netfilter/nf_nat_proto_common.c112
1 files changed, 112 insertions, 0 deletions
diff --git a/net/netfilter/nf_nat_proto_common.c b/net/netfilter/nf_nat_proto_common.c
new file mode 100644
index 0000000..9baaf73
--- /dev/null
+++ b/net/netfilter/nf_nat_proto_common.c
@@ -0,0 +1,112 @@
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
+ * (C) 2008 Patrick McHardy <kaber@trash.net>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/types.h>
+#include <linux/random.h>
+#include <linux/netfilter.h>
+#include <linux/export.h>
+
+#include <net/netfilter/nf_nat.h>
+#include <net/netfilter/nf_nat_core.h>
+#include <net/netfilter/nf_nat_l3proto.h>
+#include <net/netfilter/nf_nat_l4proto.h>
+
+bool nf_nat_l4proto_in_range(const struct nf_conntrack_tuple *tuple,
+ enum nf_nat_manip_type maniptype,
+ const union nf_conntrack_man_proto *min,
+ const union nf_conntrack_man_proto *max)
+{
+ __be16 port;
+
+ if (maniptype == NF_NAT_MANIP_SRC)
+ port = tuple->src.u.all;
+ else
+ port = tuple->dst.u.all;
+
+ return ntohs(port) >= ntohs(min->all) &&
+ ntohs(port) <= ntohs(max->all);
+}
+EXPORT_SYMBOL_GPL(nf_nat_l4proto_in_range);
+
+void nf_nat_l4proto_unique_tuple(const struct nf_nat_l3proto *l3proto,
+ struct nf_conntrack_tuple *tuple,
+ const struct nf_nat_range *range,
+ enum nf_nat_manip_type maniptype,
+ const struct nf_conn *ct,
+ u16 *rover)
+{
+ unsigned int range_size, min, i;
+ __be16 *portptr;
+ u_int16_t off;
+
+ if (maniptype == NF_NAT_MANIP_SRC)
+ portptr = &tuple->src.u.all;
+ else
+ portptr = &tuple->dst.u.all;
+
+ /* If no range specified... */
+ if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED)) {
+ /* If it's dst rewrite, can't change port */
+ if (maniptype == NF_NAT_MANIP_DST)
+ return;
+
+ if (ntohs(*portptr) < 1024) {
+ /* Loose convention: >> 512 is credential passing */
+ if (ntohs(*portptr) < 512) {
+ min = 1;
+ range_size = 511 - min + 1;
+ } else {
+ min = 600;
+ range_size = 1023 - min + 1;
+ }
+ } else {
+ min = 1024;
+ range_size = 65535 - 1024 + 1;
+ }
+ } else {
+ min = ntohs(range->min_proto.all);
+ range_size = ntohs(range->max_proto.all) - min + 1;
+ }
+
+ if (range->flags & NF_NAT_RANGE_PROTO_RANDOM)
+ off = l3proto->secure_port(tuple, maniptype == NF_NAT_MANIP_SRC
+ ? tuple->dst.u.all
+ : tuple->src.u.all);
+ else
+ off = *rover;
+
+ for (i = 0; ; ++off) {
+ *portptr = htons(min + off % range_size);
+ if (++i != range_size && nf_nat_used_tuple(tuple, ct))
+ continue;
+ if (!(range->flags & NF_NAT_RANGE_PROTO_RANDOM))
+ *rover = off;
+ return;
+ }
+ return;
+}
+EXPORT_SYMBOL_GPL(nf_nat_l4proto_unique_tuple);
+
+#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
+int nf_nat_l4proto_nlattr_to_range(struct nlattr *tb[],
+ struct nf_nat_range *range)
+{
+ if (tb[CTA_PROTONAT_PORT_MIN]) {
+ range->min_proto.all = nla_get_be16(tb[CTA_PROTONAT_PORT_MIN]);
+ range->max_proto.all = range->min_proto.all;
+ range->flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
+ }
+ if (tb[CTA_PROTONAT_PORT_MAX]) {
+ range->max_proto.all = nla_get_be16(tb[CTA_PROTONAT_PORT_MAX]);
+ range->flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(nf_nat_l4proto_nlattr_to_range);
+#endif
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