| /* (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/ip.h> |
| |
| #include <linux/netfilter.h> |
| #include <linux/export.h> |
| #include <net/secure_seq.h> |
| #include <net/netfilter/nf_nat.h> |
| #include <net/netfilter/nf_nat_core.h> |
| #include <net/netfilter/nf_nat_rule.h> |
| #include <net/netfilter/nf_nat_protocol.h> |
| |
| bool nf_nat_proto_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 == IP_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_proto_in_range); |
| |
| void nf_nat_proto_unique_tuple(struct nf_conntrack_tuple *tuple, |
| const struct nf_nat_range *range, |
| enum nf_nat_manip_type maniptype, |
| const struct nf_conn *ct, |
| u_int16_t *rover) |
| { |
| unsigned int range_size, min, i; |
| __be16 *portptr; |
| u_int16_t off; |
| |
| if (maniptype == IP_NAT_MANIP_SRC) |
| portptr = &tuple->src.u.all; |
| else |
| portptr = &tuple->dst.u.all; |
| |
| /* If no range specified... */ |
| if (!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED)) { |
| /* If it's dst rewrite, can't change port */ |
| if (maniptype == IP_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.all); |
| range_size = ntohs(range->max.all) - min + 1; |
| } |
| |
| if (range->flags & IP_NAT_RANGE_PROTO_RANDOM) |
| off = secure_ipv4_port_ephemeral(tuple->src.u3.ip, tuple->dst.u3.ip, |
| maniptype == IP_NAT_MANIP_SRC |
| ? tuple->dst.u.all |
| : tuple->src.u.all); |
| else |
| off = *rover; |
| |
| /* 4rd specific range NAPT - start */ |
| if ((range->flags & IP_NAT_RANGE_4RD_NAPT) && (maniptype == IP_NAT_MANIP_SRC)){ |
| __be16 fix_port; |
| __be16 port_min, port_max; |
| u_int16_t port_set_id; |
| u_int16_t mbitlen = 0 ; |
| u_int16_t offsetlen = 0 ; |
| u_int16_t psidlen = 0 ; |
| u_int16_t range_total_size = 0 ; |
| u_int16_t offset_4rd; |
| u_int16_t o_state; |
| u_int16_t m_state; |
| |
| u_int16_t offset_min; |
| u_int16_t offset_max; |
| u_int16_t offset_cnt; |
| u_int16_t mbit_cnt; |
| |
| # define MAXBITLEN 16 |
| port_min = ntohs(range->min.all); |
| port_max = ntohs(range->max.all); |
| |
| for(i = 0; i < MAXBITLEN; i++){ |
| if( ((port_min >> i) & 0x0001) == ((port_max >> i) & 0x0001) ){ |
| psidlen++; |
| i++; |
| break; |
| } |
| else{ |
| mbitlen++; |
| } |
| } |
| |
| for( ; i < MAXBITLEN; i++){ |
| if( ((port_min >> i) & 0x0001) == ((port_max >> i) & 0x0001) ){ |
| psidlen++; |
| } |
| else{ |
| break; |
| } |
| } |
| |
| offsetlen = MAXBITLEN - psidlen - mbitlen; |
| |
| if((psidlen == 0) || (mbitlen == 0)){ |
| /* ERROR */ |
| printk(KERN_INFO "4rd parameter INVALID"); |
| } |
| |
| port_set_id = (port_min & port_max) >> mbitlen; |
| |
| if( offsetlen ){ |
| if(port_min < 4096){ |
| if(offsetlen > 4){ |
| |
| |
| offset_min = 0x1000 >> (psidlen + mbitlen); |
| offset_max = (1 << offsetlen) - 1; |
| offset_cnt = offset_max - offset_min + 1; |
| mbit_cnt = 1 << mbitlen; |
| range_total_size = offset_cnt * mbit_cnt; |
| } |
| else{ |
| offset_min = 0x0001; |
| offset_cnt = (1 << offsetlen) - 1; |
| mbit_cnt = 1 << mbitlen; |
| range_total_size = offset_cnt * mbit_cnt; |
| } |
| } |
| else{ |
| offset_min = 0x0000; |
| offset_cnt = 1 << offsetlen; |
| mbit_cnt = 1 << mbitlen; |
| range_total_size = offset_cnt * mbit_cnt; |
| } |
| } |
| else{ |
| offset_min = 0; |
| range_total_size = ( 1 << mbitlen ) ; |
| } |
| |
| for (i = 0; ; ++off) { |
| |
| offset_4rd = off % range_total_size ; |
| |
| if ( mbitlen != 0 ){ |
| o_state = offset_4rd / ( 1 << mbitlen ) ; |
| m_state = offset_4rd % ( 1 << mbitlen ) ; |
| }else{ |
| o_state = offset_4rd / ( 1 << mbitlen ) ; |
| m_state = 0 ; |
| } |
| |
| fix_port = (( offset_min + o_state ) << ( mbitlen + psidlen )); |
| fix_port |= ( port_set_id << mbitlen ); |
| fix_port |= m_state; |
| |
| *portptr = htons(fix_port); |
| |
| if ((++i != range_total_size) && nf_nat_used_tuple(tuple, ct)) |
| continue; |
| |
| //printk(KERN_INFO "fix_port = %d ",fix_port); |
| return ; |
| } |
| } /* 4rd specific range NAPT - end */ |
| else{ |
| |
| for (i = 0; ; ++off) { |
| *portptr = htons(min + off % range_size); |
| if (++i != range_size && nf_nat_used_tuple(tuple, ct)) |
| continue; |
| if (!(range->flags & IP_NAT_RANGE_PROTO_RANDOM)) |
| *rover = off; |
| return; |
| } |
| } |
| return; |
| } |
| EXPORT_SYMBOL_GPL(nf_nat_proto_unique_tuple); |
| |
| #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE) |
| int nf_nat_proto_range_to_nlattr(struct sk_buff *skb, |
| const struct nf_nat_range *range) |
| { |
| NLA_PUT_BE16(skb, CTA_PROTONAT_PORT_MIN, range->min.all); |
| NLA_PUT_BE16(skb, CTA_PROTONAT_PORT_MAX, range->max.all); |
| return 0; |
| |
| nla_put_failure: |
| return -1; |
| } |
| EXPORT_SYMBOL_GPL(nf_nat_proto_nlattr_to_range); |
| |
| int nf_nat_proto_nlattr_to_range(struct nlattr *tb[], |
| struct nf_nat_range *range) |
| { |
| if (tb[CTA_PROTONAT_PORT_MIN]) { |
| range->min.all = nla_get_be16(tb[CTA_PROTONAT_PORT_MIN]); |
| range->max.all = range->min.tcp.port; |
| range->flags |= IP_NAT_RANGE_PROTO_SPECIFIED; |
| } |
| if (tb[CTA_PROTONAT_PORT_MAX]) { |
| range->max.all = nla_get_be16(tb[CTA_PROTONAT_PORT_MAX]); |
| range->flags |= IP_NAT_RANGE_PROTO_SPECIFIED; |
| } |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(nf_nat_proto_range_to_nlattr); |
| #endif |
