| 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; |
| 45 | |
| 46 | if (maniptype == IP_NAT_MANIP_SRC) |
| 47 | portptr = &tuple->src.u.all; |
| 48 | else |
| 49 | portptr = &tuple->dst.u.all; |
| 50 | |
| 51 | /* If no range specified... */ |
| 52 | if (!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED)) { |
| 53 | /* If it's dst rewrite, can't change port */ |
| 54 | if (maniptype == IP_NAT_MANIP_DST) |
| 55 | return 0; |
| 56 | |
| 57 | if (ntohs(*portptr) < 1024) { |
| 58 | /* Loose convention: >> 512 is credential passing */ |
| 59 | if (ntohs(*portptr) < 512) { |
| 60 | min = 1; |
| 61 | range_size = 511 - min + 1; |
| 62 | } else { |
| 63 | min = 600; |
| 64 | range_size = 1023 - min + 1; |
| 65 | } |
| 66 | } else { |
| 67 | min = 1024; |
| 68 | range_size = 65535 - 1024 + 1; |
| 69 | } |
| 70 | } else { |
| 71 | min = ntohs(range->min.all); |
| 72 | range_size = ntohs(range->max.all) - min + 1; |
| 73 | } |
| 74 | |
| 75 | if (range->flags & IP_NAT_RANGE_PROTO_RANDOM) |
| 76 | *rover = net_random(); |
| 77 | |
| 78 | for (i = 0; i < range_size; i++, (*rover)++) { |
| 79 | *portptr = htons(min + *rover % range_size); |
| 80 | if (!nf_nat_used_tuple(tuple, ct)) |
| 81 | return 1; |
| 82 | } |
| 83 | return 0; |
| 84 | } |
| 85 | EXPORT_SYMBOL_GPL(nf_nat_proto_unique_tuple); |