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10#include <linux/types.h>
11#include <linux/random.h>
12#include <linux/netfilter.h>
13#include <linux/export.h>
14
15#include <net/netfilter/nf_nat.h>
16#include <net/netfilter/nf_nat_core.h>
17#include <net/netfilter/nf_nat_l3proto.h>
18#include <net/netfilter/nf_nat_l4proto.h>
19
20bool nf_nat_l4proto_in_range(const struct nf_conntrack_tuple *tuple,
21 enum nf_nat_manip_type maniptype,
22 const union nf_conntrack_man_proto *min,
23 const union nf_conntrack_man_proto *max)
24{
25 __be16 port;
26
27 if (maniptype == NF_NAT_MANIP_SRC)
28 port = tuple->src.u.all;
29 else
30 port = tuple->dst.u.all;
31
32 return ntohs(port) >= ntohs(min->all) &&
33 ntohs(port) <= ntohs(max->all);
34}
35EXPORT_SYMBOL_GPL(nf_nat_l4proto_in_range);
36
37void nf_nat_l4proto_unique_tuple(const struct nf_nat_l3proto *l3proto,
38 struct nf_conntrack_tuple *tuple,
39 const struct nf_nat_range2 *range,
40 enum nf_nat_manip_type maniptype,
41 const struct nf_conn *ct,
42 u16 *rover)
43{
44 unsigned int range_size, min, max, i;
45 __be16 *portptr;
46 u_int16_t off;
47
48 if (maniptype == NF_NAT_MANIP_SRC)
49 portptr = &tuple->src.u.all;
50 else
51 portptr = &tuple->dst.u.all;
52
53
54 if (!(range->flags & NF_NAT_RANGE_PROTO_SPECIFIED)) {
55
56 if (maniptype == NF_NAT_MANIP_DST)
57 return;
58
59 if (ntohs(*portptr) < 1024) {
60
61 if (ntohs(*portptr) < 512) {
62 min = 1;
63 range_size = 511 - min + 1;
64 } else {
65 min = 600;
66 range_size = 1023 - min + 1;
67 }
68 } else {
69 min = 1024;
70 range_size = 65535 - 1024 + 1;
71 }
72 } else {
73 min = ntohs(range->min_proto.all);
74 max = ntohs(range->max_proto.all);
75 if (unlikely(max < min))
76 swap(max, min);
77 range_size = max - min + 1;
78 }
79
80 if (range->flags & NF_NAT_RANGE_PROTO_RANDOM) {
81 off = l3proto->secure_port(tuple, maniptype == NF_NAT_MANIP_SRC
82 ? tuple->dst.u.all
83 : tuple->src.u.all);
84 } else if (range->flags & NF_NAT_RANGE_PROTO_RANDOM_FULLY) {
85 off = prandom_u32();
86 } else if (range->flags & NF_NAT_RANGE_PROTO_OFFSET) {
87 off = (ntohs(*portptr) - ntohs(range->base_proto.all));
88 } else {
89 off = *rover;
90 }
91
92 for (i = 0; ; ++off) {
93 *portptr = htons(min + off % range_size);
94 if (++i != range_size && nf_nat_used_tuple(tuple, ct))
95 continue;
96 if (!(range->flags & (NF_NAT_RANGE_PROTO_RANDOM_ALL|
97 NF_NAT_RANGE_PROTO_OFFSET)))
98 *rover = off;
99 return;
100 }
101}
102EXPORT_SYMBOL_GPL(nf_nat_l4proto_unique_tuple);
103
104#if IS_ENABLED(CONFIG_NF_CT_NETLINK)
105int nf_nat_l4proto_nlattr_to_range(struct nlattr *tb[],
106 struct nf_nat_range2 *range)
107{
108 if (tb[CTA_PROTONAT_PORT_MIN]) {
109 range->min_proto.all = nla_get_be16(tb[CTA_PROTONAT_PORT_MIN]);
110 range->max_proto.all = range->min_proto.all;
111 range->flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
112 }
113 if (tb[CTA_PROTONAT_PORT_MAX]) {
114 range->max_proto.all = nla_get_be16(tb[CTA_PROTONAT_PORT_MAX]);
115 range->flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
116 }
117 return 0;
118}
119EXPORT_SYMBOL_GPL(nf_nat_l4proto_nlattr_to_range);
120#endif
121