/* * xfrm6_policy.c: based on xfrm4_policy.c * * Authors: * Mitsuru KANDA @USAGI * Kazunori MIYAZAWA @USAGI * Kunihiro Ishiguro <kunihiro@ipinfusion.com> * IPv6 support * YOSHIFUJI Hideaki * Split up af-specific portion * */ #include <linux/compiler.h> #include <linux/netdevice.h> #include <net/addrconf.h> #include <net/xfrm.h> #include <net/ip.h> #include <net/ipv6.h> #include <net/ip6_route.h> #ifdef CONFIG_IPV6_MIP6 #include <net/mip6.h> #endif static struct dst_ops xfrm6_dst_ops; static struct xfrm_policy_afinfo xfrm6_policy_afinfo; static int xfrm6_dst_lookup(struct xfrm_dst **xdst, struct flowi *fl) { struct dst_entry *dst = ip6_route_output(NULL, fl); int err = dst->error; if (!err) *xdst = (struct xfrm_dst *) dst; else dst_release(dst); return err; } static int xfrm6_get_saddr(xfrm_address_t *saddr, xfrm_address_t *daddr) { struct rt6_info *rt; struct flowi fl_tunnel = { .nl_u = { .ip6_u = { .daddr = *(struct in6_addr *)&daddr->a6, }, }, }; if (!xfrm6_dst_lookup((struct xfrm_dst **)&rt, &fl_tunnel)) { ipv6_get_saddr(&rt->u.dst, (struct in6_addr *)&daddr->a6, (struct in6_addr *)&saddr->a6); dst_release(&rt->u.dst); return 0; } return -EHOSTUNREACH; } static struct dst_entry * __xfrm6_find_bundle(struct flowi *fl, struct xfrm_policy *policy) { struct dst_entry *dst; /* Still not clear if we should set fl->fl6_{src,dst}... */ read_lock_bh(&policy->lock); for (dst = policy->bundles; dst; dst = dst->next) { struct xfrm_dst *xdst = (struct xfrm_dst*)dst; struct in6_addr fl_dst_prefix, fl_src_prefix; ipv6_addr_prefix(&fl_dst_prefix, &fl->fl6_dst, xdst->u.rt6.rt6i_dst.plen); ipv6_addr_prefix(&fl_src_prefix, &fl->fl6_src, xdst->u.rt6.rt6i_src.plen); if (ipv6_addr_equal(&xdst->u.rt6.rt6i_dst.addr, &fl_dst_prefix) && ipv6_addr_equal(&xdst->u.rt6.rt6i_src.addr, &fl_src_prefix) && xfrm_bundle_ok(policy, xdst, fl, AF_INET6, (xdst->u.rt6.rt6i_dst.plen != 128 || xdst->u.rt6.rt6i_src.plen != 128))) { dst_clone(dst); break; } } read_unlock_bh(&policy->lock); return dst; } static inline struct in6_addr* __xfrm6_bundle_addr_remote(struct xfrm_state *x, struct in6_addr *addr) { return (x->type->remote_addr) ? (struct in6_addr*)x->type->remote_addr(x, (xfrm_address_t *)addr) : (struct in6_addr*)&x->id.daddr; } static inline struct in6_addr* __xfrm6_bundle_addr_local(struct xfrm_state *x, struct in6_addr *addr) { return (x->type->local_addr) ? (struct in6_addr*)x->type->local_addr(x, (xfrm_address_t *)addr) : (struct in6_addr*)&x->props.saddr; } static inline void __xfrm6_bundle_len_inc(int *len, int *nflen, struct xfrm_state *x) { if (x->type->flags & XFRM_TYPE_NON_FRAGMENT) *nflen += x->props.header_len; else *len += x->props.header_len; } static inline void __xfrm6_bundle_len_dec(int *len, int *nflen, struct xfrm_state *x) { if (x->type->flags & XFRM_TYPE_NON_FRAGMENT) *nflen -= x->props.header_len; else *len -= x->props.header_len; } /* Allocate chain of dst_entry's, attach known xfrm's, calculate * all the metrics... Shortly, bundle a bundle. */ static int __xfrm6_bundle_create(struct xfrm_policy *policy, struct xfrm_state **xfrm, int nx, struct flowi *fl, struct dst_entry **dst_p) { struct dst_entry *dst, *dst_prev; struct rt6_info *rt0 = (struct rt6_info*)(*dst_p); struct rt6_info *rt = rt0; struct flowi fl_tunnel = { .nl_u = { .ip6_u = { .saddr = fl->fl6_src, .daddr = fl->fl6_dst, } } }; int i; int err = 0; int header_len = 0; int nfheader_len = 0; int trailer_len = 0; dst = dst_prev = NULL; dst_hold(&rt->u.dst); for (i = 0; i < nx; i++) { struct dst_entry *dst1 = dst_alloc(&xfrm6_dst_ops); struct xfrm_dst *xdst; if (unlikely(dst1 == NULL)) { err = -ENOBUFS; dst_release(&rt->u.dst); goto error; } if (!dst) dst = dst1; else { dst_prev->child = dst1; dst1->flags |= DST_NOHASH; dst_clone(dst1); } xdst = (struct xfrm_dst *)dst1; xdst->route = &rt->u.dst; xdst->genid = xfrm[i]->genid; if (rt->rt6i_node) xdst->route_cookie = rt->rt6i_node->fn_sernum; dst1->next = dst_prev; dst_prev = dst1; __xfrm6_bundle_len_inc(&header_len, &nfheader_len, xfrm[i]); trailer_len += xfrm[i]->props.trailer_len; if (xfrm[i]->props.mode == XFRM_MODE_TUNNEL || xfrm[i]->props.mode == XFRM_MODE_ROUTEOPTIMIZATION) { unsigned short encap_family = xfrm[i]->props.family; switch(encap_family) { case AF_INET: fl_tunnel.fl4_dst = xfrm[i]->id.daddr.a4; fl_tunnel.fl4_src = xfrm[i]->props.saddr.a4; break; case AF_INET6: ipv6_addr_copy(&fl_tunnel.fl6_dst, __xfrm6_bundle_addr_remote(xfrm[i], &fl->fl6_dst)); ipv6_addr_copy(&fl_tunnel.fl6_src, __xfrm6_bundle_addr_local(xfrm[i], &fl->fl6_src)); break; default: BUG_ON(1); } err = xfrm_dst_lookup((struct xfrm_dst **) &rt, &fl_tunnel, encap_family); if (err) goto error; } else dst_hold(&rt->u.dst); } dst_prev->child = &rt->u.dst; dst->path = &rt->u.dst; if (rt->rt6i_node) ((struct xfrm_dst *)dst)->path_cookie = rt->rt6i_node->fn_sernum; *dst_p = dst; dst = dst_prev; dst_prev = *dst_p; i = 0; for (; dst_prev != &rt->u.dst; dst_prev = dst_prev->child) { struct xfrm_dst *x = (struct xfrm_dst*)dst_prev; struct xfrm_state_afinfo *afinfo; dst_prev->xfrm = xfrm[i++]; dst_prev->dev = rt->u.dst.dev; if (rt->u.dst.dev) dev_hold(rt->u.dst.dev); dst_prev->obsolete = -1; dst_prev->flags |= DST_HOST; dst_prev->lastuse = jiffies; dst_prev->header_len = header_len; dst_prev->nfheader_len = nfheader_len; dst_prev->trailer_len = trailer_len; memcpy(&dst_prev->metrics, &x->route->metrics, sizeof(dst_prev->metrics)); /* Copy neighbour for reachability confirmation */ dst_prev->neighbour = neigh_clone(rt->u.dst.neighbour); dst_prev->input = rt->u.dst.input; /* XXX: When IPv4 is implemented as module and can be unloaded, * we should manage reference to xfrm4_output in afinfo->output. * Miyazawa */ afinfo = xfrm_state_get_afinfo(dst_prev->xfrm->props.family); if (!afinfo) { dst = *dst_p; goto error; }; dst_prev->output = afinfo->output; xfrm_state_put_afinfo(afinfo); /* Sheit... I remember I did this right. Apparently, * it was magically lost, so this code needs audit */ x->u.rt6.rt6i_flags = rt0->rt6i_flags&(RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL); x->u.rt6.rt6i_metric = rt0->rt6i_metric; x->u.rt6.rt6i_node = rt0->rt6i_node; x->u.rt6.rt6i_gateway = rt0->rt6i_gateway; memcpy(&x->u.rt6.rt6i_gateway, &rt0->rt6i_gateway, sizeof(x->u.rt6.rt6i_gateway)); x->u.rt6.rt6i_dst = rt0->rt6i_dst; x->u.rt6.rt6i_src = rt0->rt6i_src; x->u.rt6.rt6i_idev = rt0->rt6i_idev; in6_dev_hold(rt0->rt6i_idev); __xfrm6_bundle_len_dec(&header_len, &nfheader_len, x->u.dst.xfrm); trailer_len -= x->u.dst.xfrm->props.trailer_len; } xfrm_init_pmtu(dst); return 0; error: if (dst) dst_free(dst); return err; } static inline void _decode_session6(struct sk_buff *skb, struct flowi *fl) { u16 offset = skb->h.raw - skb->nh.raw; struct ipv6hdr *hdr = ipv6_hdr(skb); struct ipv6_opt_hdr *exthdr; const unsigned char *nh = skb_network_header(skb); u8 nexthdr = nh[IP6CB(skb)->nhoff]; memset(fl, 0, sizeof(struct flowi)); ipv6_addr_copy(&fl->fl6_dst, &hdr->daddr); ipv6_addr_copy(&fl->fl6_src, &hdr->saddr); while (pskb_may_pull(skb, nh + offset + 1 - skb->data)) { nh = skb_network_header(skb); exthdr = (struct ipv6_opt_hdr *)(nh + offset); switch (nexthdr) { case NEXTHDR_ROUTING: case NEXTHDR_HOP: case NEXTHDR_DEST: offset += ipv6_optlen(exthdr); nexthdr = exthdr->nexthdr; exthdr = (struct ipv6_opt_hdr *)(nh + offset); break; case IPPROTO_UDP: case IPPROTO_UDPLITE: case IPPROTO_TCP: case IPPROTO_SCTP: case IPPROTO_DCCP: if (pskb_may_pull(skb, nh + offset + 4 - skb->data)) { __be16 *ports = (__be16 *)exthdr; fl->fl_ip_sport = ports[0]; fl->fl_ip_dport = ports[1]; } fl->proto = nexthdr; return; case IPPROTO_ICMPV6: if (pskb_may_pull(skb, nh + offset + 2 - skb->data)) { u8 *icmp = (u8 *)exthdr; fl->fl_icmp_type = icmp[0]; fl->fl_icmp_code = icmp[1]; } fl->proto = nexthdr; return; #ifdef CONFIG_IPV6_MIP6 case IPPROTO_MH: if (pskb_may_pull(skb, nh + offset + 3 - skb->data)) { struct ip6_mh *mh; mh = (struct ip6_mh *)exthdr; fl->fl_mh_type = mh->ip6mh_type; } fl->proto = nexthdr; return; #endif /* XXX Why are there these headers? */ case IPPROTO_AH: case IPPROTO_ESP: case IPPROTO_COMP: default: fl->fl_ipsec_spi = 0; fl->proto = nexthdr; return; }; } } static inline int xfrm6_garbage_collect(void) { xfrm6_policy_afinfo.garbage_collect(); return (atomic_read(&xfrm6_dst_ops.entries) > xfrm6_dst_ops.gc_thresh*2); } static void xfrm6_update_pmtu(struct dst_entry *dst, u32 mtu) { struct xfrm_dst *xdst = (struct xfrm_dst *)dst; struct dst_entry *path = xdst->route; path->ops->update_pmtu(path, mtu); } static void xfrm6_dst_destroy(struct dst_entry *dst) { struct xfrm_dst *xdst = (struct xfrm_dst *)dst; if (likely(xdst->u.rt6.rt6i_idev)) in6_dev_put(xdst->u.rt6.rt6i_idev); xfrm_dst_destroy(xdst); } static void xfrm6_dst_ifdown(struct dst_entry *dst, struct net_device *dev, int unregister) { struct xfrm_dst *xdst; if (!unregister) return; xdst = (struct xfrm_dst *)dst; if (xdst->u.rt6.rt6i_idev->dev == dev) { struct inet6_dev *loopback_idev = in6_dev_get(&loopback_dev); BUG_ON(!loopback_idev); do { in6_dev_put(xdst->u.rt6.rt6i_idev); xdst->u.rt6.rt6i_idev = loopback_idev; in6_dev_hold(loopback_idev); xdst = (struct xfrm_dst *)xdst->u.dst.child; } while (xdst->u.dst.xfrm); __in6_dev_put(loopback_idev); } xfrm_dst_ifdown(dst, dev); } static struct dst_ops xfrm6_dst_ops = { .family = AF_INET6, .protocol = __constant_htons(ETH_P_IPV6), .gc = xfrm6_garbage_collect, .update_pmtu = xfrm6_update_pmtu, .destroy = xfrm6_dst_destroy, .ifdown = xfrm6_dst_ifdown, .gc_thresh = 1024, .entry_size = sizeof(struct xfrm_dst), }; static struct xfrm_policy_afinfo xfrm6_policy_afinfo = { .family = AF_INET6, .dst_ops = &xfrm6_dst_ops, .dst_lookup = xfrm6_dst_lookup, .get_saddr = xfrm6_get_saddr, .find_bundle = __xfrm6_find_bundle, .bundle_create = __xfrm6_bundle_create, .decode_session = _decode_session6, }; static void __init xfrm6_policy_init(void) { xfrm_policy_register_afinfo(&xfrm6_policy_afinfo); } static void xfrm6_policy_fini(void) { xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo); } void __init xfrm6_init(void) { xfrm6_policy_init(); xfrm6_state_init(); } void xfrm6_fini(void) { //xfrm6_input_fini(); xfrm6_policy_fini(); xfrm6_state_fini(); }