/* * 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/err.h> #include <linux/kernel.h> #include <linux/netdevice.h> #include <net/addrconf.h> #include <net/dst.h> #include <net/xfrm.h> #include <net/ip.h> #include <net/ipv6.h> #include <net/ip6_route.h> #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) #include <net/mip6.h> #endif static struct xfrm_policy_afinfo xfrm6_policy_afinfo; static struct dst_entry *xfrm6_dst_lookup(struct net *net, int tos, xfrm_address_t *saddr, xfrm_address_t *daddr) { struct flowi fl = {}; struct dst_entry *dst; int err; memcpy(&fl.fl6_dst, daddr, sizeof(fl.fl6_dst)); if (saddr) memcpy(&fl.fl6_src, saddr, sizeof(fl.fl6_src)); dst = ip6_route_output(net, NULL, &fl); err = dst->error; if (dst->error) { dst_release(dst); dst = ERR_PTR(err); } return dst; } static int xfrm6_get_saddr(struct net *net, xfrm_address_t *saddr, xfrm_address_t *daddr) { struct dst_entry *dst; struct net_device *dev; dst = xfrm6_dst_lookup(net, 0, NULL, daddr); if (IS_ERR(dst)) return -EHOSTUNREACH; dev = ip6_dst_idev(dst)->dev; ipv6_dev_get_saddr(dev_net(dev), dev, (struct in6_addr *)&daddr->a6, 0, (struct in6_addr *)&saddr->a6); dst_release(dst); return 0; } 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 int xfrm6_get_tos(struct flowi *fl) { return 0; } static int xfrm6_init_path(struct xfrm_dst *path, struct dst_entry *dst, int nfheader_len) { if (dst->ops->family == AF_INET6) { struct rt6_info *rt = (struct rt6_info*)dst; if (rt->rt6i_node) path->path_cookie = rt->rt6i_node->fn_sernum; } path->u.rt6.rt6i_nfheader_len = nfheader_len; return 0; } static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev) { struct rt6_info *rt = (struct rt6_info*)xdst->route; xdst->u.dst.dev = dev; dev_hold(dev); xdst->u.rt6.rt6i_idev = in6_dev_get(rt->u.dst.dev); if (!xdst->u.rt6.rt6i_idev) return -ENODEV; /* Sheit... I remember I did this right. Apparently, * it was magically lost, so this code needs audit */ xdst->u.rt6.rt6i_flags = rt->rt6i_flags & (RTF_ANYCAST | RTF_LOCAL); xdst->u.rt6.rt6i_metric = rt->rt6i_metric; xdst->u.rt6.rt6i_node = rt->rt6i_node; if (rt->rt6i_node) xdst->route_cookie = rt->rt6i_node->fn_sernum; xdst->u.rt6.rt6i_gateway = rt->rt6i_gateway; xdst->u.rt6.rt6i_dst = rt->rt6i_dst; xdst->u.rt6.rt6i_src = rt->rt6i_src; return 0; } static inline void _decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse) { int onlyproto = 0; u16 offset = skb_network_header_len(skb); 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, reverse ? &hdr->saddr : &hdr->daddr); ipv6_addr_copy(&fl->fl6_src, reverse ? &hdr->daddr : &hdr->saddr); while (nh + offset + 1 < skb->data || 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_FRAGMENT: onlyproto = 1; 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 (!onlyproto && (nh + offset + 4 < skb->data || pskb_may_pull(skb, nh + offset + 4 - skb->data))) { __be16 *ports = (__be16 *)exthdr; fl->fl_ip_sport = ports[!!reverse]; fl->fl_ip_dport = ports[!reverse]; } fl->proto = nexthdr; return; case IPPROTO_ICMPV6: if (!onlyproto && 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; #if defined(CONFIG_IPV6_MIP6) || defined(CONFIG_IPV6_MIP6_MODULE) case IPPROTO_MH: if (!onlyproto && 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(struct dst_ops *ops) { struct net *net = container_of(ops, struct net, xfrm.xfrm6_dst_ops); xfrm6_policy_afinfo.garbage_collect(net); return (atomic_read(&ops->entries) > 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(dev_net(dev)->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 = cpu_to_be16(ETH_P_IPV6), .gc = xfrm6_garbage_collect, .update_pmtu = xfrm6_update_pmtu, .destroy = xfrm6_dst_destroy, .ifdown = xfrm6_dst_ifdown, .local_out = __ip6_local_out, .gc_thresh = 1024, .entries = ATOMIC_INIT(0), }; 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, .decode_session = _decode_session6, .get_tos = xfrm6_get_tos, .init_path = xfrm6_init_path, .fill_dst = xfrm6_fill_dst, }; static int __init xfrm6_policy_init(void) { return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo); } static void xfrm6_policy_fini(void) { xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo); } #ifdef CONFIG_SYSCTL static struct ctl_table xfrm6_policy_table[] = { { .procname = "xfrm6_gc_thresh", .data = &init_net.xfrm.xfrm6_dst_ops.gc_thresh, .maxlen = sizeof(int), .mode = 0644, .proc_handler = proc_dointvec, }, { } }; static struct ctl_table_header *sysctl_hdr; #endif int __init xfrm6_init(void) { int ret; unsigned int gc_thresh; /* * We need a good default value for the xfrm6 gc threshold. * In ipv4 we set it to the route hash table size * 8, which * is half the size of the maximaum route cache for ipv4. It * would be good to do the same thing for v6, except the table is * constructed differently here. Here each table for a net namespace * can have FIB_TABLE_HASHSZ entries, so lets go with the same * computation that we used for ipv4 here. Also, lets keep the initial * gc_thresh to a minimum of 1024, since, the ipv6 route cache defaults * to that as a minimum as well */ gc_thresh = FIB6_TABLE_HASHSZ * 8; xfrm6_dst_ops.gc_thresh = (gc_thresh < 1024) ? 1024 : gc_thresh; ret = xfrm6_policy_init(); if (ret) goto out; ret = xfrm6_state_init(); if (ret) goto out_policy; #ifdef CONFIG_SYSCTL sysctl_hdr = register_net_sysctl_table(&init_net, net_ipv6_ctl_path, xfrm6_policy_table); #endif out: return ret; out_policy: xfrm6_policy_fini(); goto out; } void xfrm6_fini(void) { #ifdef CONFIG_SYSCTL if (sysctl_hdr) unregister_net_sysctl_table(sysctl_hdr); #endif //xfrm6_input_fini(); xfrm6_policy_fini(); xfrm6_state_fini(); }