312 lines
7.2 KiB
C
312 lines
7.2 KiB
C
/*
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* xfrm4_policy.c
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*
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* Changes:
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* Kazunori MIYAZAWA @USAGI
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* YOSHIFUJI Hideaki @USAGI
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* Split up af-specific portion
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*
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*/
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#include <linux/err.h>
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#include <linux/kernel.h>
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#include <linux/inetdevice.h>
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#include <net/dst.h>
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#include <net/xfrm.h>
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#include <net/ip.h>
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static struct dst_ops xfrm4_dst_ops;
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static struct xfrm_policy_afinfo xfrm4_policy_afinfo;
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static struct dst_entry *xfrm4_dst_lookup(struct net *net, int tos,
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xfrm_address_t *saddr,
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xfrm_address_t *daddr)
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{
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struct flowi fl = {
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.nl_u = {
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.ip4_u = {
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.tos = tos,
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.daddr = daddr->a4,
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},
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},
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};
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struct dst_entry *dst;
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struct rtable *rt;
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int err;
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if (saddr)
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fl.fl4_src = saddr->a4;
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err = __ip_route_output_key(net, &rt, &fl);
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dst = &rt->u.dst;
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if (err)
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dst = ERR_PTR(err);
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return dst;
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}
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static int xfrm4_get_saddr(struct net *net,
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xfrm_address_t *saddr, xfrm_address_t *daddr)
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{
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struct dst_entry *dst;
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struct rtable *rt;
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dst = xfrm4_dst_lookup(net, 0, NULL, daddr);
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if (IS_ERR(dst))
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return -EHOSTUNREACH;
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rt = (struct rtable *)dst;
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saddr->a4 = rt->rt_src;
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dst_release(dst);
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return 0;
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}
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static struct dst_entry *
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__xfrm4_find_bundle(struct flowi *fl, struct xfrm_policy *policy)
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{
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struct dst_entry *dst;
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read_lock_bh(&policy->lock);
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for (dst = policy->bundles; dst; dst = dst->next) {
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struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
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if (xdst->u.rt.fl.oif == fl->oif && /*XXX*/
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xdst->u.rt.fl.fl4_dst == fl->fl4_dst &&
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xdst->u.rt.fl.fl4_src == fl->fl4_src &&
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xdst->u.rt.fl.fl4_tos == fl->fl4_tos &&
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xfrm_bundle_ok(policy, xdst, fl, AF_INET, 0)) {
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dst_clone(dst);
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break;
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}
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}
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read_unlock_bh(&policy->lock);
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return dst;
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}
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static int xfrm4_get_tos(struct flowi *fl)
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{
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return fl->fl4_tos;
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}
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static int xfrm4_init_path(struct xfrm_dst *path, struct dst_entry *dst,
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int nfheader_len)
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{
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return 0;
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}
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static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev)
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{
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struct rtable *rt = (struct rtable *)xdst->route;
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xdst->u.rt.fl = rt->fl;
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xdst->u.dst.dev = dev;
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dev_hold(dev);
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xdst->u.rt.idev = in_dev_get(dev);
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if (!xdst->u.rt.idev)
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return -ENODEV;
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xdst->u.rt.peer = rt->peer;
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if (rt->peer)
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atomic_inc(&rt->peer->refcnt);
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/* Sheit... I remember I did this right. Apparently,
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* it was magically lost, so this code needs audit */
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xdst->u.rt.rt_flags = rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST |
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RTCF_LOCAL);
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xdst->u.rt.rt_type = rt->rt_type;
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xdst->u.rt.rt_src = rt->rt_src;
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xdst->u.rt.rt_dst = rt->rt_dst;
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xdst->u.rt.rt_gateway = rt->rt_gateway;
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xdst->u.rt.rt_spec_dst = rt->rt_spec_dst;
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return 0;
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}
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static void
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_decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse)
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{
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struct iphdr *iph = ip_hdr(skb);
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u8 *xprth = skb_network_header(skb) + iph->ihl * 4;
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memset(fl, 0, sizeof(struct flowi));
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if (!(iph->frag_off & htons(IP_MF | IP_OFFSET))) {
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switch (iph->protocol) {
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case IPPROTO_UDP:
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case IPPROTO_UDPLITE:
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case IPPROTO_TCP:
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case IPPROTO_SCTP:
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case IPPROTO_DCCP:
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if (xprth + 4 < skb->data ||
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pskb_may_pull(skb, xprth + 4 - skb->data)) {
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__be16 *ports = (__be16 *)xprth;
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fl->fl_ip_sport = ports[!!reverse];
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fl->fl_ip_dport = ports[!reverse];
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}
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break;
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case IPPROTO_ICMP:
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if (pskb_may_pull(skb, xprth + 2 - skb->data)) {
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u8 *icmp = xprth;
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fl->fl_icmp_type = icmp[0];
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fl->fl_icmp_code = icmp[1];
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}
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break;
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case IPPROTO_ESP:
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if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
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__be32 *ehdr = (__be32 *)xprth;
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fl->fl_ipsec_spi = ehdr[0];
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}
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break;
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case IPPROTO_AH:
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if (pskb_may_pull(skb, xprth + 8 - skb->data)) {
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__be32 *ah_hdr = (__be32*)xprth;
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fl->fl_ipsec_spi = ah_hdr[1];
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}
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break;
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case IPPROTO_COMP:
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if (pskb_may_pull(skb, xprth + 4 - skb->data)) {
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__be16 *ipcomp_hdr = (__be16 *)xprth;
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fl->fl_ipsec_spi = htonl(ntohs(ipcomp_hdr[1]));
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}
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break;
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default:
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fl->fl_ipsec_spi = 0;
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break;
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}
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}
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fl->proto = iph->protocol;
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fl->fl4_dst = reverse ? iph->saddr : iph->daddr;
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fl->fl4_src = reverse ? iph->daddr : iph->saddr;
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fl->fl4_tos = iph->tos;
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}
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static inline int xfrm4_garbage_collect(struct dst_ops *ops)
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{
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xfrm4_policy_afinfo.garbage_collect(&init_net);
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return (atomic_read(&xfrm4_dst_ops.entries) > xfrm4_dst_ops.gc_thresh*2);
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}
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static void xfrm4_update_pmtu(struct dst_entry *dst, u32 mtu)
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{
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struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
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struct dst_entry *path = xdst->route;
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path->ops->update_pmtu(path, mtu);
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}
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static void xfrm4_dst_destroy(struct dst_entry *dst)
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{
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struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
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if (likely(xdst->u.rt.idev))
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in_dev_put(xdst->u.rt.idev);
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if (likely(xdst->u.rt.peer))
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inet_putpeer(xdst->u.rt.peer);
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xfrm_dst_destroy(xdst);
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}
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static void xfrm4_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
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int unregister)
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{
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struct xfrm_dst *xdst;
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if (!unregister)
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return;
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xdst = (struct xfrm_dst *)dst;
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if (xdst->u.rt.idev->dev == dev) {
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struct in_device *loopback_idev =
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in_dev_get(dev_net(dev)->loopback_dev);
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BUG_ON(!loopback_idev);
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do {
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in_dev_put(xdst->u.rt.idev);
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xdst->u.rt.idev = loopback_idev;
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in_dev_hold(loopback_idev);
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xdst = (struct xfrm_dst *)xdst->u.dst.child;
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} while (xdst->u.dst.xfrm);
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__in_dev_put(loopback_idev);
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}
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xfrm_dst_ifdown(dst, dev);
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}
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static struct dst_ops xfrm4_dst_ops = {
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.family = AF_INET,
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.protocol = cpu_to_be16(ETH_P_IP),
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.gc = xfrm4_garbage_collect,
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.update_pmtu = xfrm4_update_pmtu,
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.destroy = xfrm4_dst_destroy,
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.ifdown = xfrm4_dst_ifdown,
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.local_out = __ip_local_out,
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.gc_thresh = 1024,
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.entries = ATOMIC_INIT(0),
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};
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static struct xfrm_policy_afinfo xfrm4_policy_afinfo = {
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.family = AF_INET,
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.dst_ops = &xfrm4_dst_ops,
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.dst_lookup = xfrm4_dst_lookup,
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.get_saddr = xfrm4_get_saddr,
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.find_bundle = __xfrm4_find_bundle,
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.decode_session = _decode_session4,
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.get_tos = xfrm4_get_tos,
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.init_path = xfrm4_init_path,
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.fill_dst = xfrm4_fill_dst,
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};
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static struct ctl_table xfrm4_policy_table[] = {
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{
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.ctl_name = CTL_UNNUMBERED,
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.procname = "xfrm4_gc_thresh",
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.data = &xfrm4_dst_ops.gc_thresh,
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.maxlen = sizeof(int),
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.mode = 0644,
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.proc_handler = proc_dointvec,
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},
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{ }
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};
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static struct ctl_table_header *sysctl_hdr;
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static void __init xfrm4_policy_init(void)
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{
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xfrm_policy_register_afinfo(&xfrm4_policy_afinfo);
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}
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static void __exit xfrm4_policy_fini(void)
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{
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if (sysctl_hdr)
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unregister_net_sysctl_table(sysctl_hdr);
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xfrm_policy_unregister_afinfo(&xfrm4_policy_afinfo);
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}
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void __init xfrm4_init(int rt_max_size)
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{
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xfrm4_state_init();
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xfrm4_policy_init();
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/*
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* Select a default value for the gc_thresh based on the main route
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* table hash size. It seems to me the worst case scenario is when
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* we have ipsec operating in transport mode, in which we create a
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* dst_entry per socket. The xfrm gc algorithm starts trying to remove
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* entries at gc_thresh, and prevents new allocations as 2*gc_thresh
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* so lets set an initial xfrm gc_thresh value at the rt_max_size/2.
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* That will let us store an ipsec connection per route table entry,
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* and start cleaning when were 1/2 full
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*/
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xfrm4_dst_ops.gc_thresh = rt_max_size/2;
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sysctl_hdr = register_net_sysctl_table(&init_net, net_ipv4_ctl_path,
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xfrm4_policy_table);
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}
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