summaryrefslogtreecommitdiff
path: root/net/ipv6/mip6.c
diff options
context:
space:
mode:
Diffstat (limited to 'net/ipv6/mip6.c')
-rw-r--r--net/ipv6/mip6.c525
1 files changed, 525 insertions, 0 deletions
diff --git a/net/ipv6/mip6.c b/net/ipv6/mip6.c
new file mode 100644
index 00000000..7e1e0fbf
--- /dev/null
+++ b/net/ipv6/mip6.c
@@ -0,0 +1,525 @@
+/*
+ * Copyright (C)2003-2006 Helsinki University of Technology
+ * Copyright (C)2003-2006 USAGI/WIDE Project
+ *
+ * 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
+ */
+/*
+ * Authors:
+ * Noriaki TAKAMIYA @USAGI
+ * Masahide NAKAMURA @USAGI
+ */
+
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/time.h>
+#include <linux/ipv6.h>
+#include <linux/icmpv6.h>
+#include <net/sock.h>
+#include <net/ipv6.h>
+#include <net/ip6_checksum.h>
+#include <net/rawv6.h>
+#include <net/xfrm.h>
+#include <net/mip6.h>
+
+static inline unsigned int calc_padlen(unsigned int len, unsigned int n)
+{
+ return (n - len + 16) & 0x7;
+}
+
+static inline void *mip6_padn(__u8 *data, __u8 padlen)
+{
+ if (!data)
+ return NULL;
+ if (padlen == 1) {
+ data[0] = IPV6_TLV_PAD0;
+ } else if (padlen > 1) {
+ data[0] = IPV6_TLV_PADN;
+ data[1] = padlen - 2;
+ if (padlen > 2)
+ memset(data+2, 0, data[1]);
+ }
+ return data + padlen;
+}
+
+static inline void mip6_param_prob(struct sk_buff *skb, u8 code, int pos)
+{
+ icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos);
+}
+
+static int mip6_mh_len(int type)
+{
+ int len = 0;
+
+ switch (type) {
+ case IP6_MH_TYPE_BRR:
+ len = 0;
+ break;
+ case IP6_MH_TYPE_HOTI:
+ case IP6_MH_TYPE_COTI:
+ case IP6_MH_TYPE_BU:
+ case IP6_MH_TYPE_BACK:
+ len = 1;
+ break;
+ case IP6_MH_TYPE_HOT:
+ case IP6_MH_TYPE_COT:
+ case IP6_MH_TYPE_BERROR:
+ len = 2;
+ break;
+ }
+ return len;
+}
+
+static int mip6_mh_filter(struct sock *sk, struct sk_buff *skb)
+{
+ struct ip6_mh *mh;
+
+ if (!pskb_may_pull(skb, (skb_transport_offset(skb)) + 8) ||
+ !pskb_may_pull(skb, (skb_transport_offset(skb) +
+ ((skb_transport_header(skb)[1] + 1) << 3))))
+ return -1;
+
+ mh = (struct ip6_mh *)skb_transport_header(skb);
+
+ if (mh->ip6mh_hdrlen < mip6_mh_len(mh->ip6mh_type)) {
+ LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH message too short: %d vs >=%d\n",
+ mh->ip6mh_hdrlen, mip6_mh_len(mh->ip6mh_type));
+ mip6_param_prob(skb, 0, ((&mh->ip6mh_hdrlen) -
+ skb_network_header(skb)));
+ return -1;
+ }
+
+ if (mh->ip6mh_proto != IPPROTO_NONE) {
+ LIMIT_NETDEBUG(KERN_DEBUG "mip6: MH invalid payload proto = %d\n",
+ mh->ip6mh_proto);
+ mip6_param_prob(skb, 0, ((&mh->ip6mh_proto) -
+ skb_network_header(skb)));
+ return -1;
+ }
+
+ return 0;
+}
+
+struct mip6_report_rate_limiter {
+ spinlock_t lock;
+ struct timeval stamp;
+ int iif;
+ struct in6_addr src;
+ struct in6_addr dst;
+};
+
+static struct mip6_report_rate_limiter mip6_report_rl = {
+ .lock = __SPIN_LOCK_UNLOCKED(mip6_report_rl.lock)
+};
+
+static int mip6_destopt_input(struct xfrm_state *x, struct sk_buff *skb)
+{
+ const struct ipv6hdr *iph = ipv6_hdr(skb);
+ struct ipv6_destopt_hdr *destopt = (struct ipv6_destopt_hdr *)skb->data;
+ int err = destopt->nexthdr;
+
+ spin_lock(&x->lock);
+ if (!ipv6_addr_equal(&iph->saddr, (struct in6_addr *)x->coaddr) &&
+ !ipv6_addr_any((struct in6_addr *)x->coaddr))
+ err = -ENOENT;
+ spin_unlock(&x->lock);
+
+ return err;
+}
+
+/* Destination Option Header is inserted.
+ * IP Header's src address is replaced with Home Address Option in
+ * Destination Option Header.
+ */
+static int mip6_destopt_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+ struct ipv6hdr *iph;
+ struct ipv6_destopt_hdr *dstopt;
+ struct ipv6_destopt_hao *hao;
+ u8 nexthdr;
+ int len;
+
+ skb_push(skb, -skb_network_offset(skb));
+ iph = ipv6_hdr(skb);
+
+ nexthdr = *skb_mac_header(skb);
+ *skb_mac_header(skb) = IPPROTO_DSTOPTS;
+
+ dstopt = (struct ipv6_destopt_hdr *)skb_transport_header(skb);
+ dstopt->nexthdr = nexthdr;
+
+ hao = mip6_padn((char *)(dstopt + 1),
+ calc_padlen(sizeof(*dstopt), 6));
+
+ hao->type = IPV6_TLV_HAO;
+ BUILD_BUG_ON(sizeof(*hao) != 18);
+ hao->length = sizeof(*hao) - 2;
+
+ len = ((char *)hao - (char *)dstopt) + sizeof(*hao);
+
+ memcpy(&hao->addr, &iph->saddr, sizeof(hao->addr));
+ spin_lock_bh(&x->lock);
+ memcpy(&iph->saddr, x->coaddr, sizeof(iph->saddr));
+ spin_unlock_bh(&x->lock);
+
+ WARN_ON(len != x->props.header_len);
+ dstopt->hdrlen = (x->props.header_len >> 3) - 1;
+
+ return 0;
+}
+
+static inline int mip6_report_rl_allow(struct timeval *stamp,
+ const struct in6_addr *dst,
+ const struct in6_addr *src, int iif)
+{
+ int allow = 0;
+
+ spin_lock_bh(&mip6_report_rl.lock);
+ if (mip6_report_rl.stamp.tv_sec != stamp->tv_sec ||
+ mip6_report_rl.stamp.tv_usec != stamp->tv_usec ||
+ mip6_report_rl.iif != iif ||
+ !ipv6_addr_equal(&mip6_report_rl.src, src) ||
+ !ipv6_addr_equal(&mip6_report_rl.dst, dst)) {
+ mip6_report_rl.stamp.tv_sec = stamp->tv_sec;
+ mip6_report_rl.stamp.tv_usec = stamp->tv_usec;
+ mip6_report_rl.iif = iif;
+ mip6_report_rl.src = *src;
+ mip6_report_rl.dst = *dst;
+ allow = 1;
+ }
+ spin_unlock_bh(&mip6_report_rl.lock);
+ return allow;
+}
+
+static int mip6_destopt_reject(struct xfrm_state *x, struct sk_buff *skb,
+ const struct flowi *fl)
+{
+ struct net *net = xs_net(x);
+ struct inet6_skb_parm *opt = (struct inet6_skb_parm *)skb->cb;
+ const struct flowi6 *fl6 = &fl->u.ip6;
+ struct ipv6_destopt_hao *hao = NULL;
+ struct xfrm_selector sel;
+ int offset;
+ struct timeval stamp;
+ int err = 0;
+
+ if (unlikely(fl6->flowi6_proto == IPPROTO_MH &&
+ fl6->fl6_mh_type <= IP6_MH_TYPE_MAX))
+ goto out;
+
+ if (likely(opt->dsthao)) {
+ offset = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
+ if (likely(offset >= 0))
+ hao = (struct ipv6_destopt_hao *)
+ (skb_network_header(skb) + offset);
+ }
+
+ skb_get_timestamp(skb, &stamp);
+
+ if (!mip6_report_rl_allow(&stamp, &ipv6_hdr(skb)->daddr,
+ hao ? &hao->addr : &ipv6_hdr(skb)->saddr,
+ opt->iif))
+ goto out;
+
+ memset(&sel, 0, sizeof(sel));
+ memcpy(&sel.daddr, (xfrm_address_t *)&ipv6_hdr(skb)->daddr,
+ sizeof(sel.daddr));
+ sel.prefixlen_d = 128;
+ memcpy(&sel.saddr, (xfrm_address_t *)&ipv6_hdr(skb)->saddr,
+ sizeof(sel.saddr));
+ sel.prefixlen_s = 128;
+ sel.family = AF_INET6;
+ sel.proto = fl6->flowi6_proto;
+ sel.dport = xfrm_flowi_dport(fl, &fl6->uli);
+ if (sel.dport)
+ sel.dport_mask = htons(~0);
+ sel.sport = xfrm_flowi_sport(fl, &fl6->uli);
+ if (sel.sport)
+ sel.sport_mask = htons(~0);
+ sel.ifindex = fl6->flowi6_oif;
+
+ err = km_report(net, IPPROTO_DSTOPTS, &sel,
+ (hao ? (xfrm_address_t *)&hao->addr : NULL));
+
+ out:
+ return err;
+}
+
+static int mip6_destopt_offset(struct xfrm_state *x, struct sk_buff *skb,
+ u8 **nexthdr)
+{
+ u16 offset = sizeof(struct ipv6hdr);
+ struct ipv6_opt_hdr *exthdr =
+ (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
+ const unsigned char *nh = skb_network_header(skb);
+ unsigned int packet_len = skb->tail - skb->network_header;
+ int found_rhdr = 0;
+
+ *nexthdr = &ipv6_hdr(skb)->nexthdr;
+
+ while (offset + 1 <= packet_len) {
+
+ switch (**nexthdr) {
+ case NEXTHDR_HOP:
+ break;
+ case NEXTHDR_ROUTING:
+ found_rhdr = 1;
+ break;
+ case NEXTHDR_DEST:
+ /*
+ * HAO MUST NOT appear more than once.
+ * XXX: It is better to try to find by the end of
+ * XXX: packet if HAO exists.
+ */
+ if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) {
+ LIMIT_NETDEBUG(KERN_WARNING "mip6: hao exists already, override\n");
+ return offset;
+ }
+
+ if (found_rhdr)
+ return offset;
+
+ break;
+ default:
+ return offset;
+ }
+
+ offset += ipv6_optlen(exthdr);
+ *nexthdr = &exthdr->nexthdr;
+ exthdr = (struct ipv6_opt_hdr *)(nh + offset);
+ }
+
+ return offset;
+}
+
+static int mip6_destopt_init_state(struct xfrm_state *x)
+{
+ if (x->id.spi) {
+ printk(KERN_INFO "%s: spi is not 0: %u\n", __func__,
+ x->id.spi);
+ return -EINVAL;
+ }
+ if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
+ printk(KERN_INFO "%s: state's mode is not %u: %u\n",
+ __func__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
+ return -EINVAL;
+ }
+
+ x->props.header_len = sizeof(struct ipv6_destopt_hdr) +
+ calc_padlen(sizeof(struct ipv6_destopt_hdr), 6) +
+ sizeof(struct ipv6_destopt_hao);
+ WARN_ON(x->props.header_len != 24);
+
+ return 0;
+}
+
+/*
+ * Do nothing about destroying since it has no specific operation for
+ * destination options header unlike IPsec protocols.
+ */
+static void mip6_destopt_destroy(struct xfrm_state *x)
+{
+}
+
+static const struct xfrm_type mip6_destopt_type =
+{
+ .description = "MIP6DESTOPT",
+ .owner = THIS_MODULE,
+ .proto = IPPROTO_DSTOPTS,
+ .flags = XFRM_TYPE_NON_FRAGMENT | XFRM_TYPE_LOCAL_COADDR,
+ .init_state = mip6_destopt_init_state,
+ .destructor = mip6_destopt_destroy,
+ .input = mip6_destopt_input,
+ .output = mip6_destopt_output,
+ .reject = mip6_destopt_reject,
+ .hdr_offset = mip6_destopt_offset,
+};
+
+static int mip6_rthdr_input(struct xfrm_state *x, struct sk_buff *skb)
+{
+ const struct ipv6hdr *iph = ipv6_hdr(skb);
+ struct rt2_hdr *rt2 = (struct rt2_hdr *)skb->data;
+ int err = rt2->rt_hdr.nexthdr;
+
+ spin_lock(&x->lock);
+ if (!ipv6_addr_equal(&iph->daddr, (struct in6_addr *)x->coaddr) &&
+ !ipv6_addr_any((struct in6_addr *)x->coaddr))
+ err = -ENOENT;
+ spin_unlock(&x->lock);
+
+ return err;
+}
+
+/* Routing Header type 2 is inserted.
+ * IP Header's dst address is replaced with Routing Header's Home Address.
+ */
+static int mip6_rthdr_output(struct xfrm_state *x, struct sk_buff *skb)
+{
+ struct ipv6hdr *iph;
+ struct rt2_hdr *rt2;
+ u8 nexthdr;
+
+ skb_push(skb, -skb_network_offset(skb));
+ iph = ipv6_hdr(skb);
+
+ nexthdr = *skb_mac_header(skb);
+ *skb_mac_header(skb) = IPPROTO_ROUTING;
+
+ rt2 = (struct rt2_hdr *)skb_transport_header(skb);
+ rt2->rt_hdr.nexthdr = nexthdr;
+ rt2->rt_hdr.hdrlen = (x->props.header_len >> 3) - 1;
+ rt2->rt_hdr.type = IPV6_SRCRT_TYPE_2;
+ rt2->rt_hdr.segments_left = 1;
+ memset(&rt2->reserved, 0, sizeof(rt2->reserved));
+
+ WARN_ON(rt2->rt_hdr.hdrlen != 2);
+
+ memcpy(&rt2->addr, &iph->daddr, sizeof(rt2->addr));
+ spin_lock_bh(&x->lock);
+ memcpy(&iph->daddr, x->coaddr, sizeof(iph->daddr));
+ spin_unlock_bh(&x->lock);
+
+ return 0;
+}
+
+static int mip6_rthdr_offset(struct xfrm_state *x, struct sk_buff *skb,
+ u8 **nexthdr)
+{
+ u16 offset = sizeof(struct ipv6hdr);
+ struct ipv6_opt_hdr *exthdr =
+ (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
+ const unsigned char *nh = skb_network_header(skb);
+ unsigned int packet_len = skb->tail - skb->network_header;
+ int found_rhdr = 0;
+
+ *nexthdr = &ipv6_hdr(skb)->nexthdr;
+
+ while (offset + 1 <= packet_len) {
+
+ switch (**nexthdr) {
+ case NEXTHDR_HOP:
+ break;
+ case NEXTHDR_ROUTING:
+ if (offset + 3 <= packet_len) {
+ struct ipv6_rt_hdr *rt;
+ rt = (struct ipv6_rt_hdr *)(nh + offset);
+ if (rt->type != 0)
+ return offset;
+ }
+ found_rhdr = 1;
+ break;
+ case NEXTHDR_DEST:
+ if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
+ return offset;
+
+ if (found_rhdr)
+ return offset;
+
+ break;
+ default:
+ return offset;
+ }
+
+ offset += ipv6_optlen(exthdr);
+ *nexthdr = &exthdr->nexthdr;
+ exthdr = (struct ipv6_opt_hdr *)(nh + offset);
+ }
+
+ return offset;
+}
+
+static int mip6_rthdr_init_state(struct xfrm_state *x)
+{
+ if (x->id.spi) {
+ printk(KERN_INFO "%s: spi is not 0: %u\n", __func__,
+ x->id.spi);
+ return -EINVAL;
+ }
+ if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
+ printk(KERN_INFO "%s: state's mode is not %u: %u\n",
+ __func__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
+ return -EINVAL;
+ }
+
+ x->props.header_len = sizeof(struct rt2_hdr);
+
+ return 0;
+}
+
+/*
+ * Do nothing about destroying since it has no specific operation for routing
+ * header type 2 unlike IPsec protocols.
+ */
+static void mip6_rthdr_destroy(struct xfrm_state *x)
+{
+}
+
+static const struct xfrm_type mip6_rthdr_type =
+{
+ .description = "MIP6RT",
+ .owner = THIS_MODULE,
+ .proto = IPPROTO_ROUTING,
+ .flags = XFRM_TYPE_NON_FRAGMENT | XFRM_TYPE_REMOTE_COADDR,
+ .init_state = mip6_rthdr_init_state,
+ .destructor = mip6_rthdr_destroy,
+ .input = mip6_rthdr_input,
+ .output = mip6_rthdr_output,
+ .hdr_offset = mip6_rthdr_offset,
+};
+
+static int __init mip6_init(void)
+{
+ printk(KERN_INFO "Mobile IPv6\n");
+
+ if (xfrm_register_type(&mip6_destopt_type, AF_INET6) < 0) {
+ printk(KERN_INFO "%s: can't add xfrm type(destopt)\n", __func__);
+ goto mip6_destopt_xfrm_fail;
+ }
+ if (xfrm_register_type(&mip6_rthdr_type, AF_INET6) < 0) {
+ printk(KERN_INFO "%s: can't add xfrm type(rthdr)\n", __func__);
+ goto mip6_rthdr_xfrm_fail;
+ }
+ if (rawv6_mh_filter_register(mip6_mh_filter) < 0) {
+ printk(KERN_INFO "%s: can't add rawv6 mh filter\n", __func__);
+ goto mip6_rawv6_mh_fail;
+ }
+
+
+ return 0;
+
+ mip6_rawv6_mh_fail:
+ xfrm_unregister_type(&mip6_rthdr_type, AF_INET6);
+ mip6_rthdr_xfrm_fail:
+ xfrm_unregister_type(&mip6_destopt_type, AF_INET6);
+ mip6_destopt_xfrm_fail:
+ return -EAGAIN;
+}
+
+static void __exit mip6_fini(void)
+{
+ if (rawv6_mh_filter_unregister(mip6_mh_filter) < 0)
+ printk(KERN_INFO "%s: can't remove rawv6 mh filter\n", __func__);
+ if (xfrm_unregister_type(&mip6_rthdr_type, AF_INET6) < 0)
+ printk(KERN_INFO "%s: can't remove xfrm type(rthdr)\n", __func__);
+ if (xfrm_unregister_type(&mip6_destopt_type, AF_INET6) < 0)
+ printk(KERN_INFO "%s: can't remove xfrm type(destopt)\n", __func__);
+}
+
+module_init(mip6_init);
+module_exit(mip6_fini);
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_DSTOPTS);
+MODULE_ALIAS_XFRM_TYPE(AF_INET6, XFRM_PROTO_ROUTING);
generated by cgit (git 2.34.1) at 2024-12-20 11:22:00 +0000