362 lines
8.4 KiB
C
362 lines
8.4 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/compiler.h>
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#include <linux/inetdevice.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 int xfrm4_dst_lookup(struct xfrm_dst **dst, struct flowi *fl)
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{
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return __ip_route_output_key((struct rtable**)dst, fl);
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}
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static int xfrm4_get_saddr(xfrm_address_t *saddr, xfrm_address_t *daddr)
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{
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struct rtable *rt;
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struct flowi fl_tunnel = {
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.nl_u = {
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.ip4_u = {
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.daddr = daddr->a4,
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},
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},
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};
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if (!xfrm4_dst_lookup((struct xfrm_dst **)&rt, &fl_tunnel)) {
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saddr->a4 = rt->rt_src;
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dst_release(&rt->u.dst);
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return 0;
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}
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return -EHOSTUNREACH;
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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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/* Allocate chain of dst_entry's, attach known xfrm's, calculate
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* all the metrics... Shortly, bundle a bundle.
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*/
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static int
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__xfrm4_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int nx,
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struct flowi *fl, struct dst_entry **dst_p)
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{
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struct dst_entry *dst, *dst_prev;
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struct rtable *rt0 = (struct rtable*)(*dst_p);
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struct rtable *rt = rt0;
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struct flowi fl_tunnel = {
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.nl_u = {
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.ip4_u = {
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.saddr = fl->fl4_src,
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.daddr = fl->fl4_dst,
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.tos = fl->fl4_tos
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}
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}
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};
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int i;
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int err;
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int header_len = 0;
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int trailer_len = 0;
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dst = dst_prev = NULL;
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dst_hold(&rt->u.dst);
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for (i = 0; i < nx; i++) {
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struct dst_entry *dst1 = dst_alloc(&xfrm4_dst_ops);
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struct xfrm_dst *xdst;
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if (unlikely(dst1 == NULL)) {
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err = -ENOBUFS;
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dst_release(&rt->u.dst);
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goto error;
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}
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if (!dst)
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dst = dst1;
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else {
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dst_prev->child = dst1;
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dst1->flags |= DST_NOHASH;
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dst_clone(dst1);
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}
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xdst = (struct xfrm_dst *)dst1;
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xdst->route = &rt->u.dst;
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xdst->genid = xfrm[i]->genid;
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dst1->next = dst_prev;
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dst_prev = dst1;
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header_len += xfrm[i]->props.header_len;
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trailer_len += xfrm[i]->props.trailer_len;
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if (xfrm[i]->props.mode == XFRM_MODE_TUNNEL) {
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unsigned short encap_family = xfrm[i]->props.family;
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switch(encap_family) {
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case AF_INET:
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fl_tunnel.fl4_dst = xfrm[i]->id.daddr.a4;
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fl_tunnel.fl4_src = xfrm[i]->props.saddr.a4;
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break;
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#if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE)
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case AF_INET6:
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ipv6_addr_copy(&fl_tunnel.fl6_dst, (struct in6_addr*)&xfrm[i]->id.daddr.a6);
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ipv6_addr_copy(&fl_tunnel.fl6_src, (struct in6_addr*)&xfrm[i]->props.saddr.a6);
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break;
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#endif
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default:
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BUG_ON(1);
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}
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err = xfrm_dst_lookup((struct xfrm_dst **)&rt,
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&fl_tunnel, encap_family);
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if (err)
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goto error;
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} else
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dst_hold(&rt->u.dst);
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}
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dst_prev->child = &rt->u.dst;
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dst->path = &rt->u.dst;
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*dst_p = dst;
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dst = dst_prev;
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dst_prev = *dst_p;
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i = 0;
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for (; dst_prev != &rt->u.dst; dst_prev = dst_prev->child) {
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struct xfrm_dst *x = (struct xfrm_dst*)dst_prev;
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struct xfrm_state_afinfo *afinfo;
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x->u.rt.fl = *fl;
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dst_prev->xfrm = xfrm[i++];
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dst_prev->dev = rt->u.dst.dev;
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if (rt->u.dst.dev)
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dev_hold(rt->u.dst.dev);
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dst_prev->obsolete = -1;
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dst_prev->flags |= DST_HOST;
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dst_prev->lastuse = jiffies;
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dst_prev->header_len = header_len;
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dst_prev->nfheader_len = 0;
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dst_prev->trailer_len = trailer_len;
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memcpy(&dst_prev->metrics, &x->route->metrics, sizeof(dst_prev->metrics));
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/* Copy neighbout for reachability confirmation */
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dst_prev->neighbour = neigh_clone(rt->u.dst.neighbour);
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dst_prev->input = rt->u.dst.input;
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/* XXX: When IPv6 module can be unloaded, we should manage reference
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* to xfrm6_output in afinfo->output. Miyazawa
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* */
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afinfo = xfrm_state_get_afinfo(dst_prev->xfrm->props.family);
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if (!afinfo) {
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dst = *dst_p;
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err = -EAFNOSUPPORT;
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goto error;
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}
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dst_prev->output = afinfo->output;
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xfrm_state_put_afinfo(afinfo);
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if (dst_prev->xfrm->props.family == AF_INET && rt->peer)
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atomic_inc(&rt->peer->refcnt);
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x->u.rt.peer = rt->peer;
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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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x->u.rt.rt_flags = rt0->rt_flags&(RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL);
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x->u.rt.rt_type = rt->rt_type;
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x->u.rt.rt_src = rt0->rt_src;
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x->u.rt.rt_dst = rt0->rt_dst;
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x->u.rt.rt_gateway = rt->rt_gateway;
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x->u.rt.rt_spec_dst = rt0->rt_spec_dst;
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x->u.rt.idev = rt0->idev;
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in_dev_hold(rt0->idev);
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header_len -= x->u.dst.xfrm->props.header_len;
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trailer_len -= x->u.dst.xfrm->props.trailer_len;
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}
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xfrm_init_pmtu(dst);
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return 0;
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error:
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if (dst)
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dst_free(dst);
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return err;
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}
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static void
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_decode_session4(struct sk_buff *skb, struct flowi *fl)
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{
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struct iphdr *iph = skb->nh.iph;
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u8 *xprth = skb->nh.raw + 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 (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[0];
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fl->fl_ip_dport = ports[1];
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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 = iph->daddr;
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fl->fl4_src = 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(void)
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{
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xfrm4_policy_afinfo.garbage_collect();
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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 (dst->xfrm->props.family == AF_INET && 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 = in_dev_get(&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 = __constant_htons(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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.gc_thresh = 1024,
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.entry_size = sizeof(struct xfrm_dst),
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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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.bundle_create = __xfrm4_bundle_create,
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.decode_session = _decode_session4,
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};
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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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xfrm_policy_unregister_afinfo(&xfrm4_policy_afinfo);
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}
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void __init xfrm4_init(void)
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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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