diff options
author | Patrick McHardy <kaber@trash.net> | 2012-08-26 21:14:06 +0400 |
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committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2012-08-30 05:00:14 +0400 |
commit | c7232c9979cba684c50b64c513c4a83c9aa70563 (patch) | |
tree | dbe0fdac62191d85935f5a3dfe815c1b1add60f9 /net/netfilter/nf_nat_proto_common.c | |
parent | 051966c0c644a1c96092d4206e00704ade813c9a (diff) | |
download | linux-c7232c9979cba684c50b64c513c4a83c9aa70563.tar.xz |
netfilter: add protocol independent NAT core
Convert the IPv4 NAT implementation to a protocol independent core and
address family specific modules.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Diffstat (limited to 'net/netfilter/nf_nat_proto_common.c')
-rw-r--r-- | net/netfilter/nf_nat_proto_common.c | 112 |
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 000000000000..9baaf734c142 --- /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 |