Patrick McHardy | 937e0df | 2008-03-20 15:15:47 +0100 | [diff] [blame] | 1 | /* (C) 1999-2001 Paul `Rusty' Russell |
| 2 | * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org> |
| 3 | * (C) 2008 Patrick McHardy <kaber@trash.net> |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License version 2 as |
| 7 | * published by the Free Software Foundation. |
| 8 | */ |
| 9 | |
| 10 | #include <linux/types.h> |
| 11 | #include <linux/random.h> |
| 12 | #include <linux/ip.h> |
| 13 | |
| 14 | #include <linux/netfilter.h> |
| 15 | #include <net/netfilter/nf_nat.h> |
| 16 | #include <net/netfilter/nf_nat_core.h> |
| 17 | #include <net/netfilter/nf_nat_rule.h> |
| 18 | #include <net/netfilter/nf_nat_protocol.h> |
| 19 | |
| 20 | int nf_nat_proto_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 == IP_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 | } |
| 35 | EXPORT_SYMBOL_GPL(nf_nat_proto_in_range); |
| 36 | |
| 37 | int nf_nat_proto_unique_tuple(struct nf_conntrack_tuple *tuple, |
| 38 | const struct nf_nat_range *range, |
| 39 | enum nf_nat_manip_type maniptype, |
| 40 | const struct nf_conn *ct, |
| 41 | u_int16_t *rover) |
| 42 | { |
| 43 | unsigned int range_size, min, i; |
| 44 | __be16 *portptr; |
Patrick McHardy | 5abd363 | 2008-04-14 11:15:46 +0200 | [diff] [blame] | 45 | u_int16_t off; |
Patrick McHardy | 937e0df | 2008-03-20 15:15:47 +0100 | [diff] [blame] | 46 | |
| 47 | if (maniptype == IP_NAT_MANIP_SRC) |
| 48 | portptr = &tuple->src.u.all; |
| 49 | else |
| 50 | portptr = &tuple->dst.u.all; |
| 51 | |
| 52 | /* If no range specified... */ |
| 53 | if (!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED)) { |
| 54 | /* If it's dst rewrite, can't change port */ |
| 55 | if (maniptype == IP_NAT_MANIP_DST) |
| 56 | return 0; |
| 57 | |
| 58 | if (ntohs(*portptr) < 1024) { |
| 59 | /* Loose convention: >> 512 is credential passing */ |
| 60 | if (ntohs(*portptr) < 512) { |
| 61 | min = 1; |
| 62 | range_size = 511 - min + 1; |
| 63 | } else { |
| 64 | min = 600; |
| 65 | range_size = 1023 - min + 1; |
| 66 | } |
| 67 | } else { |
| 68 | min = 1024; |
| 69 | range_size = 65535 - 1024 + 1; |
| 70 | } |
| 71 | } else { |
| 72 | min = ntohs(range->min.all); |
| 73 | range_size = ntohs(range->max.all) - min + 1; |
| 74 | } |
| 75 | |
Patrick McHardy | 5abd363 | 2008-04-14 11:15:46 +0200 | [diff] [blame] | 76 | off = *rover; |
Patrick McHardy | 937e0df | 2008-03-20 15:15:47 +0100 | [diff] [blame] | 77 | if (range->flags & IP_NAT_RANGE_PROTO_RANDOM) |
Patrick McHardy | 5abd363 | 2008-04-14 11:15:46 +0200 | [diff] [blame] | 78 | off = net_random(); |
Patrick McHardy | 937e0df | 2008-03-20 15:15:47 +0100 | [diff] [blame] | 79 | |
Patrick McHardy | 5abd363 | 2008-04-14 11:15:46 +0200 | [diff] [blame] | 80 | for (i = 0; i < range_size; i++, off++) { |
| 81 | *portptr = htons(min + off % range_size); |
| 82 | if (nf_nat_used_tuple(tuple, ct)) |
| 83 | continue; |
| 84 | if (!(range->flags & IP_NAT_RANGE_PROTO_RANDOM)) |
| 85 | *rover = off; |
| 86 | return 1; |
Patrick McHardy | 937e0df | 2008-03-20 15:15:47 +0100 | [diff] [blame] | 87 | } |
| 88 | return 0; |
| 89 | } |
| 90 | EXPORT_SYMBOL_GPL(nf_nat_proto_unique_tuple); |
Patrick McHardy | 535b57c | 2008-04-14 11:15:47 +0200 | [diff] [blame^] | 91 | |
| 92 | #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) |
| 93 | int nf_nat_proto_range_to_nlattr(struct sk_buff *skb, |
| 94 | const struct nf_nat_range *range) |
| 95 | { |
| 96 | NLA_PUT_BE16(skb, CTA_PROTONAT_PORT_MIN, range->min.all); |
| 97 | NLA_PUT_BE16(skb, CTA_PROTONAT_PORT_MAX, range->max.all); |
| 98 | return 0; |
| 99 | |
| 100 | nla_put_failure: |
| 101 | return -1; |
| 102 | } |
| 103 | EXPORT_SYMBOL_GPL(nf_nat_proto_nlattr_to_range); |
| 104 | |
| 105 | int nf_nat_proto_nlattr_to_range(struct nlattr *tb[], |
| 106 | struct nf_nat_range *range) |
| 107 | { |
| 108 | int ret = 0; |
| 109 | |
| 110 | /* we have to return whether we actually parsed something or not */ |
| 111 | |
| 112 | if (tb[CTA_PROTONAT_PORT_MIN]) { |
| 113 | ret = 1; |
| 114 | range->min.all = nla_get_be16(tb[CTA_PROTONAT_PORT_MIN]); |
| 115 | } |
| 116 | |
| 117 | if (!tb[CTA_PROTONAT_PORT_MAX]) { |
| 118 | if (ret) |
| 119 | range->max.all = range->min.all; |
| 120 | } else { |
| 121 | ret = 1; |
| 122 | range->max.all = nla_get_be16(tb[CTA_PROTONAT_PORT_MAX]); |
| 123 | } |
| 124 | |
| 125 | return ret; |
| 126 | } |
| 127 | EXPORT_SYMBOL_GPL(nf_nat_proto_range_to_nlattr); |
| 128 | #endif |