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1f3a8e49d8
No point in going through loops and hoops instead of just comparing the values. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org>
526 lines
13 KiB
C
526 lines
13 KiB
C
/*
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* Copyright (C)2003-2006 Helsinki University of Technology
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* Copyright (C)2003-2006 USAGI/WIDE Project
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, see <http://www.gnu.org/licenses/>.
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*/
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/*
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* Authors:
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* Noriaki TAKAMIYA @USAGI
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* Masahide NAKAMURA @USAGI
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/time.h>
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#include <linux/ipv6.h>
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#include <linux/icmpv6.h>
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#include <net/sock.h>
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#include <net/ipv6.h>
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#include <net/ip6_checksum.h>
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#include <net/rawv6.h>
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#include <net/xfrm.h>
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#include <net/mip6.h>
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static inline unsigned int calc_padlen(unsigned int len, unsigned int n)
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{
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return (n - len + 16) & 0x7;
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}
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static inline void *mip6_padn(__u8 *data, __u8 padlen)
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{
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if (!data)
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return NULL;
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if (padlen == 1) {
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data[0] = IPV6_TLV_PAD1;
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} else if (padlen > 1) {
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data[0] = IPV6_TLV_PADN;
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data[1] = padlen - 2;
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if (padlen > 2)
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memset(data+2, 0, data[1]);
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}
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return data + padlen;
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}
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static inline void mip6_param_prob(struct sk_buff *skb, u8 code, int pos)
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{
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icmpv6_send(skb, ICMPV6_PARAMPROB, code, pos);
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}
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static int mip6_mh_len(int type)
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{
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int len = 0;
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switch (type) {
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case IP6_MH_TYPE_BRR:
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len = 0;
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break;
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case IP6_MH_TYPE_HOTI:
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case IP6_MH_TYPE_COTI:
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case IP6_MH_TYPE_BU:
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case IP6_MH_TYPE_BACK:
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len = 1;
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break;
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case IP6_MH_TYPE_HOT:
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case IP6_MH_TYPE_COT:
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case IP6_MH_TYPE_BERROR:
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len = 2;
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break;
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}
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return len;
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}
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static int mip6_mh_filter(struct sock *sk, struct sk_buff *skb)
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{
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struct ip6_mh _hdr;
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const struct ip6_mh *mh;
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mh = skb_header_pointer(skb, skb_transport_offset(skb),
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sizeof(_hdr), &_hdr);
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if (!mh)
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return -1;
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if (((mh->ip6mh_hdrlen + 1) << 3) > skb->len)
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return -1;
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if (mh->ip6mh_hdrlen < mip6_mh_len(mh->ip6mh_type)) {
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net_dbg_ratelimited("mip6: MH message too short: %d vs >=%d\n",
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mh->ip6mh_hdrlen,
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mip6_mh_len(mh->ip6mh_type));
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mip6_param_prob(skb, 0, offsetof(struct ip6_mh, ip6mh_hdrlen) +
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skb_network_header_len(skb));
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return -1;
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}
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if (mh->ip6mh_proto != IPPROTO_NONE) {
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net_dbg_ratelimited("mip6: MH invalid payload proto = %d\n",
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mh->ip6mh_proto);
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mip6_param_prob(skb, 0, offsetof(struct ip6_mh, ip6mh_proto) +
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skb_network_header_len(skb));
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return -1;
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}
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return 0;
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}
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struct mip6_report_rate_limiter {
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spinlock_t lock;
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ktime_t stamp;
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int iif;
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struct in6_addr src;
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struct in6_addr dst;
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};
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static struct mip6_report_rate_limiter mip6_report_rl = {
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.lock = __SPIN_LOCK_UNLOCKED(mip6_report_rl.lock)
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};
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static int mip6_destopt_input(struct xfrm_state *x, struct sk_buff *skb)
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{
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const struct ipv6hdr *iph = ipv6_hdr(skb);
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struct ipv6_destopt_hdr *destopt = (struct ipv6_destopt_hdr *)skb->data;
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int err = destopt->nexthdr;
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spin_lock(&x->lock);
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if (!ipv6_addr_equal(&iph->saddr, (struct in6_addr *)x->coaddr) &&
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!ipv6_addr_any((struct in6_addr *)x->coaddr))
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err = -ENOENT;
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spin_unlock(&x->lock);
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return err;
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}
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/* Destination Option Header is inserted.
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* IP Header's src address is replaced with Home Address Option in
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* Destination Option Header.
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*/
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static int mip6_destopt_output(struct xfrm_state *x, struct sk_buff *skb)
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{
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struct ipv6hdr *iph;
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struct ipv6_destopt_hdr *dstopt;
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struct ipv6_destopt_hao *hao;
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u8 nexthdr;
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int len;
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skb_push(skb, -skb_network_offset(skb));
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iph = ipv6_hdr(skb);
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nexthdr = *skb_mac_header(skb);
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*skb_mac_header(skb) = IPPROTO_DSTOPTS;
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dstopt = (struct ipv6_destopt_hdr *)skb_transport_header(skb);
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dstopt->nexthdr = nexthdr;
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hao = mip6_padn((char *)(dstopt + 1),
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calc_padlen(sizeof(*dstopt), 6));
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hao->type = IPV6_TLV_HAO;
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BUILD_BUG_ON(sizeof(*hao) != 18);
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hao->length = sizeof(*hao) - 2;
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len = ((char *)hao - (char *)dstopt) + sizeof(*hao);
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memcpy(&hao->addr, &iph->saddr, sizeof(hao->addr));
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spin_lock_bh(&x->lock);
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memcpy(&iph->saddr, x->coaddr, sizeof(iph->saddr));
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spin_unlock_bh(&x->lock);
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WARN_ON(len != x->props.header_len);
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dstopt->hdrlen = (x->props.header_len >> 3) - 1;
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return 0;
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}
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static inline int mip6_report_rl_allow(ktime_t stamp,
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const struct in6_addr *dst,
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const struct in6_addr *src, int iif)
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{
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int allow = 0;
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spin_lock_bh(&mip6_report_rl.lock);
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if (mip6_report_rl.stamp != stamp ||
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mip6_report_rl.iif != iif ||
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!ipv6_addr_equal(&mip6_report_rl.src, src) ||
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!ipv6_addr_equal(&mip6_report_rl.dst, dst)) {
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mip6_report_rl.stamp = stamp;
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mip6_report_rl.iif = iif;
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mip6_report_rl.src = *src;
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mip6_report_rl.dst = *dst;
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allow = 1;
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}
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spin_unlock_bh(&mip6_report_rl.lock);
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return allow;
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}
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static int mip6_destopt_reject(struct xfrm_state *x, struct sk_buff *skb,
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const struct flowi *fl)
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{
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struct net *net = xs_net(x);
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struct inet6_skb_parm *opt = (struct inet6_skb_parm *)skb->cb;
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const struct flowi6 *fl6 = &fl->u.ip6;
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struct ipv6_destopt_hao *hao = NULL;
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struct xfrm_selector sel;
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int offset;
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ktime_t stamp;
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int err = 0;
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if (unlikely(fl6->flowi6_proto == IPPROTO_MH &&
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fl6->fl6_mh_type <= IP6_MH_TYPE_MAX))
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goto out;
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if (likely(opt->dsthao)) {
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offset = ipv6_find_tlv(skb, opt->dsthao, IPV6_TLV_HAO);
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if (likely(offset >= 0))
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hao = (struct ipv6_destopt_hao *)
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(skb_network_header(skb) + offset);
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}
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stamp = skb_get_ktime(skb);
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if (!mip6_report_rl_allow(stamp, &ipv6_hdr(skb)->daddr,
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hao ? &hao->addr : &ipv6_hdr(skb)->saddr,
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opt->iif))
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goto out;
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memset(&sel, 0, sizeof(sel));
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memcpy(&sel.daddr, (xfrm_address_t *)&ipv6_hdr(skb)->daddr,
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sizeof(sel.daddr));
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sel.prefixlen_d = 128;
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memcpy(&sel.saddr, (xfrm_address_t *)&ipv6_hdr(skb)->saddr,
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sizeof(sel.saddr));
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sel.prefixlen_s = 128;
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sel.family = AF_INET6;
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sel.proto = fl6->flowi6_proto;
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sel.dport = xfrm_flowi_dport(fl, &fl6->uli);
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if (sel.dport)
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sel.dport_mask = htons(~0);
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sel.sport = xfrm_flowi_sport(fl, &fl6->uli);
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if (sel.sport)
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sel.sport_mask = htons(~0);
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sel.ifindex = fl6->flowi6_oif;
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err = km_report(net, IPPROTO_DSTOPTS, &sel,
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(hao ? (xfrm_address_t *)&hao->addr : NULL));
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out:
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return err;
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}
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static int mip6_destopt_offset(struct xfrm_state *x, struct sk_buff *skb,
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u8 **nexthdr)
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{
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u16 offset = sizeof(struct ipv6hdr);
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struct ipv6_opt_hdr *exthdr =
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(struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
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const unsigned char *nh = skb_network_header(skb);
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unsigned int packet_len = skb_tail_pointer(skb) -
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skb_network_header(skb);
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int found_rhdr = 0;
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*nexthdr = &ipv6_hdr(skb)->nexthdr;
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while (offset + 1 <= packet_len) {
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switch (**nexthdr) {
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case NEXTHDR_HOP:
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break;
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case NEXTHDR_ROUTING:
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found_rhdr = 1;
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break;
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case NEXTHDR_DEST:
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/*
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* HAO MUST NOT appear more than once.
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* XXX: It is better to try to find by the end of
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* XXX: packet if HAO exists.
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*/
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if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) {
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net_dbg_ratelimited("mip6: hao exists already, override\n");
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return offset;
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}
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if (found_rhdr)
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return offset;
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break;
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default:
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return offset;
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}
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offset += ipv6_optlen(exthdr);
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*nexthdr = &exthdr->nexthdr;
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exthdr = (struct ipv6_opt_hdr *)(nh + offset);
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}
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return offset;
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}
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static int mip6_destopt_init_state(struct xfrm_state *x)
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{
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if (x->id.spi) {
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pr_info("%s: spi is not 0: %u\n", __func__, x->id.spi);
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return -EINVAL;
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}
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if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
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pr_info("%s: state's mode is not %u: %u\n",
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__func__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
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return -EINVAL;
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}
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x->props.header_len = sizeof(struct ipv6_destopt_hdr) +
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calc_padlen(sizeof(struct ipv6_destopt_hdr), 6) +
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sizeof(struct ipv6_destopt_hao);
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WARN_ON(x->props.header_len != 24);
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return 0;
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}
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/*
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* Do nothing about destroying since it has no specific operation for
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* destination options header unlike IPsec protocols.
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*/
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static void mip6_destopt_destroy(struct xfrm_state *x)
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{
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}
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static const struct xfrm_type mip6_destopt_type = {
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.description = "MIP6DESTOPT",
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.owner = THIS_MODULE,
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.proto = IPPROTO_DSTOPTS,
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.flags = XFRM_TYPE_NON_FRAGMENT | XFRM_TYPE_LOCAL_COADDR,
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.init_state = mip6_destopt_init_state,
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.destructor = mip6_destopt_destroy,
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.input = mip6_destopt_input,
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.output = mip6_destopt_output,
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.reject = mip6_destopt_reject,
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.hdr_offset = mip6_destopt_offset,
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};
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static int mip6_rthdr_input(struct xfrm_state *x, struct sk_buff *skb)
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{
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const struct ipv6hdr *iph = ipv6_hdr(skb);
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struct rt2_hdr *rt2 = (struct rt2_hdr *)skb->data;
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int err = rt2->rt_hdr.nexthdr;
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spin_lock(&x->lock);
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if (!ipv6_addr_equal(&iph->daddr, (struct in6_addr *)x->coaddr) &&
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!ipv6_addr_any((struct in6_addr *)x->coaddr))
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err = -ENOENT;
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spin_unlock(&x->lock);
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return err;
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}
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/* Routing Header type 2 is inserted.
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* IP Header's dst address is replaced with Routing Header's Home Address.
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*/
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static int mip6_rthdr_output(struct xfrm_state *x, struct sk_buff *skb)
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{
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struct ipv6hdr *iph;
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struct rt2_hdr *rt2;
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u8 nexthdr;
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skb_push(skb, -skb_network_offset(skb));
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iph = ipv6_hdr(skb);
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nexthdr = *skb_mac_header(skb);
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*skb_mac_header(skb) = IPPROTO_ROUTING;
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rt2 = (struct rt2_hdr *)skb_transport_header(skb);
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rt2->rt_hdr.nexthdr = nexthdr;
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rt2->rt_hdr.hdrlen = (x->props.header_len >> 3) - 1;
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rt2->rt_hdr.type = IPV6_SRCRT_TYPE_2;
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rt2->rt_hdr.segments_left = 1;
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memset(&rt2->reserved, 0, sizeof(rt2->reserved));
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WARN_ON(rt2->rt_hdr.hdrlen != 2);
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memcpy(&rt2->addr, &iph->daddr, sizeof(rt2->addr));
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spin_lock_bh(&x->lock);
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memcpy(&iph->daddr, x->coaddr, sizeof(iph->daddr));
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spin_unlock_bh(&x->lock);
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return 0;
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}
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static int mip6_rthdr_offset(struct xfrm_state *x, struct sk_buff *skb,
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u8 **nexthdr)
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{
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u16 offset = sizeof(struct ipv6hdr);
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struct ipv6_opt_hdr *exthdr =
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(struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
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const unsigned char *nh = skb_network_header(skb);
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unsigned int packet_len = skb_tail_pointer(skb) -
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skb_network_header(skb);
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int found_rhdr = 0;
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*nexthdr = &ipv6_hdr(skb)->nexthdr;
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while (offset + 1 <= packet_len) {
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switch (**nexthdr) {
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case NEXTHDR_HOP:
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break;
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case NEXTHDR_ROUTING:
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if (offset + 3 <= packet_len) {
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struct ipv6_rt_hdr *rt;
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rt = (struct ipv6_rt_hdr *)(nh + offset);
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if (rt->type != 0)
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return offset;
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}
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found_rhdr = 1;
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break;
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case NEXTHDR_DEST:
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if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
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return offset;
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if (found_rhdr)
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return offset;
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break;
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default:
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return offset;
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}
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offset += ipv6_optlen(exthdr);
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*nexthdr = &exthdr->nexthdr;
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exthdr = (struct ipv6_opt_hdr *)(nh + offset);
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}
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return offset;
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}
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static int mip6_rthdr_init_state(struct xfrm_state *x)
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{
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if (x->id.spi) {
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pr_info("%s: spi is not 0: %u\n", __func__, x->id.spi);
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return -EINVAL;
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}
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if (x->props.mode != XFRM_MODE_ROUTEOPTIMIZATION) {
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pr_info("%s: state's mode is not %u: %u\n",
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__func__, XFRM_MODE_ROUTEOPTIMIZATION, x->props.mode);
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return -EINVAL;
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}
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x->props.header_len = sizeof(struct rt2_hdr);
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return 0;
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}
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/*
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* Do nothing about destroying since it has no specific operation for routing
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* header type 2 unlike IPsec protocols.
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*/
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static void mip6_rthdr_destroy(struct xfrm_state *x)
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{
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}
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static const struct xfrm_type mip6_rthdr_type = {
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.description = "MIP6RT",
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.owner = THIS_MODULE,
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.proto = IPPROTO_ROUTING,
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.flags = XFRM_TYPE_NON_FRAGMENT | XFRM_TYPE_REMOTE_COADDR,
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.init_state = mip6_rthdr_init_state,
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.destructor = mip6_rthdr_destroy,
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.input = mip6_rthdr_input,
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.output = mip6_rthdr_output,
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.hdr_offset = mip6_rthdr_offset,
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};
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static int __init mip6_init(void)
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{
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pr_info("Mobile IPv6\n");
|
|
|
|
if (xfrm_register_type(&mip6_destopt_type, AF_INET6) < 0) {
|
|
pr_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) {
|
|
pr_info("%s: can't add xfrm type(rthdr)\n", __func__);
|
|
goto mip6_rthdr_xfrm_fail;
|
|
}
|
|
if (rawv6_mh_filter_register(mip6_mh_filter) < 0) {
|
|
pr_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)
|
|
pr_info("%s: can't remove rawv6 mh filter\n", __func__);
|
|
if (xfrm_unregister_type(&mip6_rthdr_type, AF_INET6) < 0)
|
|
pr_info("%s: can't remove xfrm type(rthdr)\n", __func__);
|
|
if (xfrm_unregister_type(&mip6_destopt_type, AF_INET6) < 0)
|
|
pr_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);
|