diff options
Diffstat (limited to 'net/ipv4/netfilter/ip_nat_proto_gre.c')
| -rw-r--r-- | net/ipv4/netfilter/ip_nat_proto_gre.c | 174 |
1 files changed, 0 insertions, 174 deletions
diff --git a/net/ipv4/netfilter/ip_nat_proto_gre.c b/net/ipv4/netfilter/ip_nat_proto_gre.c deleted file mode 100644 index 95810202d849..000000000000 --- a/net/ipv4/netfilter/ip_nat_proto_gre.c +++ /dev/null @@ -1,174 +0,0 @@ -/* - * ip_nat_proto_gre.c - Version 2.0 - * - * NAT protocol helper module for GRE. - * - * GRE is a generic encapsulation protocol, which is generally not very - * suited for NAT, as it has no protocol-specific part as port numbers. - * - * It has an optional key field, which may help us distinguishing two - * connections between the same two hosts. - * - * GRE is defined in RFC 1701 and RFC 1702, as well as RFC 2784 - * - * PPTP is built on top of a modified version of GRE, and has a mandatory - * field called "CallID", which serves us for the same purpose as the key - * field in plain GRE. - * - * Documentation about PPTP can be found in RFC 2637 - * - * (C) 2000-2005 by Harald Welte <laforge@gnumonks.org> - * - * Development of this code funded by Astaro AG (http://www.astaro.com/) - * - */ - -#include <linux/module.h> -#include <linux/ip.h> -#include <linux/netfilter_ipv4/ip_nat.h> -#include <linux/netfilter_ipv4/ip_nat_rule.h> -#include <linux/netfilter_ipv4/ip_nat_protocol.h> -#include <linux/netfilter_ipv4/ip_conntrack_proto_gre.h> - -MODULE_LICENSE("GPL"); -MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>"); -MODULE_DESCRIPTION("Netfilter NAT protocol helper module for GRE"); - -#if 0 -#define DEBUGP(format, args...) printk(KERN_DEBUG "%s:%s: " format, __FILE__, \ - __FUNCTION__, ## args) -#else -#define DEBUGP(x, args...) -#endif - -/* is key in given range between min and max */ -static int -gre_in_range(const struct ip_conntrack_tuple *tuple, - enum ip_nat_manip_type maniptype, - const union ip_conntrack_manip_proto *min, - const union ip_conntrack_manip_proto *max) -{ - __be16 key; - - if (maniptype == IP_NAT_MANIP_SRC) - key = tuple->src.u.gre.key; - else - key = tuple->dst.u.gre.key; - - return ntohs(key) >= ntohs(min->gre.key) - && ntohs(key) <= ntohs(max->gre.key); -} - -/* generate unique tuple ... */ -static int -gre_unique_tuple(struct ip_conntrack_tuple *tuple, - const struct ip_nat_range *range, - enum ip_nat_manip_type maniptype, - const struct ip_conntrack *conntrack) -{ - static u_int16_t key; - __be16 *keyptr; - unsigned int min, i, range_size; - - if (maniptype == IP_NAT_MANIP_SRC) - keyptr = &tuple->src.u.gre.key; - else - keyptr = &tuple->dst.u.gre.key; - - if (!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED)) { - DEBUGP("%p: NATing GRE PPTP\n", conntrack); - min = 1; - range_size = 0xffff; - } else { - min = ntohs(range->min.gre.key); - range_size = ntohs(range->max.gre.key) - min + 1; - } - - DEBUGP("min = %u, range_size = %u\n", min, range_size); - - for (i = 0; i < range_size; i++, key++) { - *keyptr = htons(min + key % range_size); - if (!ip_nat_used_tuple(tuple, conntrack)) - return 1; - } - - DEBUGP("%p: no NAT mapping\n", conntrack); - - return 0; -} - -/* manipulate a GRE packet according to maniptype */ -static int -gre_manip_pkt(struct sk_buff **pskb, - unsigned int iphdroff, - const struct ip_conntrack_tuple *tuple, - enum ip_nat_manip_type maniptype) -{ - struct gre_hdr *greh; - struct gre_hdr_pptp *pgreh; - struct iphdr *iph = (struct iphdr *)((*pskb)->data + iphdroff); - unsigned int hdroff = iphdroff + iph->ihl*4; - - /* pgreh includes two optional 32bit fields which are not required - * to be there. That's where the magic '8' comes from */ - if (!skb_make_writable(pskb, hdroff + sizeof(*pgreh)-8)) - return 0; - - greh = (void *)(*pskb)->data + hdroff; - pgreh = (struct gre_hdr_pptp *) greh; - - /* we only have destination manip of a packet, since 'source key' - * is not present in the packet itself */ - if (maniptype == IP_NAT_MANIP_DST) { - /* key manipulation is always dest */ - switch (greh->version) { - case 0: - if (!greh->key) { - DEBUGP("can't nat GRE w/o key\n"); - break; - } - if (greh->csum) { - /* FIXME: Never tested this code... */ - nf_proto_csum_replace4(gre_csum(greh), *pskb, - *(gre_key(greh)), - tuple->dst.u.gre.key, 0); - } - *(gre_key(greh)) = tuple->dst.u.gre.key; - break; - case GRE_VERSION_PPTP: - DEBUGP("call_id -> 0x%04x\n", - ntohs(tuple->dst.u.gre.key)); - pgreh->call_id = tuple->dst.u.gre.key; - break; - default: - DEBUGP("can't nat unknown GRE version\n"); - return 0; - break; - } - } - return 1; -} - -/* nat helper struct */ -static struct ip_nat_protocol gre = { - .name = "GRE", - .protonum = IPPROTO_GRE, - .manip_pkt = gre_manip_pkt, - .in_range = gre_in_range, - .unique_tuple = gre_unique_tuple, -#if defined(CONFIG_IP_NF_CONNTRACK_NETLINK) || \ - defined(CONFIG_IP_NF_CONNTRACK_NETLINK_MODULE) - .range_to_nfattr = ip_nat_port_range_to_nfattr, - .nfattr_to_range = ip_nat_port_nfattr_to_range, -#endif -}; - -int __init ip_nat_proto_gre_init(void) -{ - return ip_nat_protocol_register(&gre); -} - -void __exit ip_nat_proto_gre_fini(void) -{ - ip_nat_protocol_unregister(&gre); -} |