/* * IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173 * * Copyright (C)2003 USAGI/WIDE Project * * Author Mitsuru KANDA <mk@linux-ipv6.org> * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ /* * [Memo] * * Outbound: * The compression of IP datagram MUST be done before AH/ESP processing, * fragmentation, and the addition of Hop-by-Hop/Routing header. * * Inbound: * The decompression of IP datagram MUST be done after the reassembly, * AH/ESP processing. */ #include <linux/module.h> #include <net/ip.h> #include <net/xfrm.h> #include <net/ipcomp.h> #include <linux/crypto.h> #include <linux/err.h> #include <linux/pfkeyv2.h> #include <linux/random.h> #include <linux/percpu.h> #include <linux/smp.h> #include <linux/list.h> #include <linux/vmalloc.h> #include <linux/rtnetlink.h> #include <net/icmp.h> #include <net/ipv6.h> #include <net/protocol.h> #include <linux/ipv6.h> #include <linux/icmpv6.h> #include <linux/mutex.h> static void ipcomp6_err(struct sk_buff *skb, struct inet6_skb_parm *opt, int type, int code, int offset, __be32 info) { __be32 spi; struct ipv6hdr *iph = (struct ipv6hdr*)skb->data; struct ip_comp_hdr *ipcomph = (struct ip_comp_hdr *)(skb->data + offset); struct xfrm_state *x; if (type != ICMPV6_DEST_UNREACH && type != ICMPV6_PKT_TOOBIG) return; spi = htonl(ntohs(ipcomph->cpi)); x = xfrm_state_lookup(&init_net, (xfrm_address_t *)&iph->daddr, spi, IPPROTO_COMP, AF_INET6); if (!x) return; printk(KERN_DEBUG "pmtu discovery on SA IPCOMP/%08x/%pI6\n", spi, &iph->daddr); xfrm_state_put(x); } static struct xfrm_state *ipcomp6_tunnel_create(struct xfrm_state *x) { struct xfrm_state *t = NULL; t = xfrm_state_alloc(&init_net); if (!t) goto out; t->id.proto = IPPROTO_IPV6; t->id.spi = xfrm6_tunnel_alloc_spi((xfrm_address_t *)&x->props.saddr); if (!t->id.spi) goto error; memcpy(t->id.daddr.a6, x->id.daddr.a6, sizeof(struct in6_addr)); memcpy(&t->sel, &x->sel, sizeof(t->sel)); t->props.family = AF_INET6; t->props.mode = x->props.mode; memcpy(t->props.saddr.a6, x->props.saddr.a6, sizeof(struct in6_addr)); if (xfrm_init_state(t)) goto error; atomic_set(&t->tunnel_users, 1); out: return t; error: t->km.state = XFRM_STATE_DEAD; xfrm_state_put(t); t = NULL; goto out; } static int ipcomp6_tunnel_attach(struct xfrm_state *x) { int err = 0; struct xfrm_state *t = NULL; __be32 spi; spi = xfrm6_tunnel_spi_lookup((xfrm_address_t *)&x->props.saddr); if (spi) t = xfrm_state_lookup(&init_net, (xfrm_address_t *)&x->id.daddr, spi, IPPROTO_IPV6, AF_INET6); if (!t) { t = ipcomp6_tunnel_create(x); if (!t) { err = -EINVAL; goto out; } xfrm_state_insert(t); xfrm_state_hold(t); } x->tunnel = t; atomic_inc(&t->tunnel_users); out: return err; } static int ipcomp6_init_state(struct xfrm_state *x) { int err = -EINVAL; x->props.header_len = 0; switch (x->props.mode) { case XFRM_MODE_TRANSPORT: break; case XFRM_MODE_TUNNEL: x->props.header_len += sizeof(struct ipv6hdr); break; default: goto out; } err = ipcomp_init_state(x); if (err) goto out; if (x->props.mode == XFRM_MODE_TUNNEL) { err = ipcomp6_tunnel_attach(x); if (err) goto error_tunnel; } err = 0; out: return err; error_tunnel: ipcomp_destroy(x); goto out; } static const struct xfrm_type ipcomp6_type = { .description = "IPCOMP6", .owner = THIS_MODULE, .proto = IPPROTO_COMP, .init_state = ipcomp6_init_state, .destructor = ipcomp_destroy, .input = ipcomp_input, .output = ipcomp_output, .hdr_offset = xfrm6_find_1stfragopt, }; static struct inet6_protocol ipcomp6_protocol = { .handler = xfrm6_rcv, .err_handler = ipcomp6_err, .flags = INET6_PROTO_NOPOLICY, }; static int __init ipcomp6_init(void) { if (xfrm_register_type(&ipcomp6_type, AF_INET6) < 0) { printk(KERN_INFO "ipcomp6 init: can't add xfrm type\n"); return -EAGAIN; } if (inet6_add_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) { printk(KERN_INFO "ipcomp6 init: can't add protocol\n"); xfrm_unregister_type(&ipcomp6_type, AF_INET6); return -EAGAIN; } return 0; } static void __exit ipcomp6_fini(void) { if (inet6_del_protocol(&ipcomp6_protocol, IPPROTO_COMP) < 0) printk(KERN_INFO "ipv6 ipcomp close: can't remove protocol\n"); if (xfrm_unregister_type(&ipcomp6_type, AF_INET6) < 0) printk(KERN_INFO "ipv6 ipcomp close: can't remove xfrm type\n"); } module_init(ipcomp6_init); module_exit(ipcomp6_fini); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("IP Payload Compression Protocol (IPComp) for IPv6 - RFC3173"); MODULE_AUTHOR("Mitsuru KANDA <mk@linux-ipv6.org>"); MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_COMP);