/* * xfrm4_policy.c * * Changes: * Kazunori MIYAZAWA @USAGI * YOSHIFUJI Hideaki @USAGI * Split up af-specific portion * */ #include <linux/compiler.h> #include <linux/inetdevice.h> #include <net/xfrm.h> #include <net/ip.h> static struct dst_ops xfrm4_dst_ops; static struct xfrm_policy_afinfo xfrm4_policy_afinfo; static int xfrm4_dst_lookup(struct xfrm_dst **dst, struct flowi *fl) { return __ip_route_output_key((struct rtable**)dst, fl); } static int xfrm4_get_saddr(xfrm_address_t *saddr, xfrm_address_t *daddr) { struct rtable *rt; struct flowi fl_tunnel = { .nl_u = { .ip4_u = { .daddr = daddr->a4, }, }, }; if (!xfrm4_dst_lookup((struct xfrm_dst **)&rt, &fl_tunnel)) { saddr->a4 = rt->rt_src; dst_release(&rt->u.dst); return 0; } return -EHOSTUNREACH; } static struct dst_entry * __xfrm4_find_bundle(struct flowi *fl, struct xfrm_policy *policy) { struct dst_entry *dst; read_lock_bh(&policy->lock); for (dst = policy->bundles; dst; dst = dst->next) { struct xfrm_dst *xdst = (struct xfrm_dst*)dst; if (xdst->u.rt.fl.oif == fl->oif && /*XXX*/ xdst->u.rt.fl.fl4_dst == fl->fl4_dst && xdst->u.rt.fl.fl4_src == fl->fl4_src && xdst->u.rt.fl.fl4_tos == fl->fl4_tos && xfrm_bundle_ok(policy, xdst, fl, AF_INET, 0)) { dst_clone(dst); break; } } read_unlock_bh(&policy->lock); return dst; } /* Allocate chain of dst_entry's, attach known xfrm's, calculate * all the metrics... Shortly, bundle a bundle. */ static int __xfrm4_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 rtable *rt0 = (struct rtable*)(*dst_p); struct rtable *rt = rt0; struct flowi fl_tunnel = { .nl_u = { .ip4_u = { .saddr = fl->fl4_src, .daddr = fl->fl4_dst, .tos = fl->fl4_tos } } }; int i; int err; int header_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(&xfrm4_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; dst1->next = dst_prev; dst_prev = dst1; header_len += xfrm[i]->props.header_len; trailer_len += xfrm[i]->props.trailer_len; if (xfrm[i]->props.mode == XFRM_MODE_TUNNEL) { 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; #if defined(CONFIG_IPV6) || defined (CONFIG_IPV6_MODULE) case AF_INET6: ipv6_addr_copy(&fl_tunnel.fl6_dst, (struct in6_addr*)&xfrm[i]->id.daddr.a6); ipv6_addr_copy(&fl_tunnel.fl6_src, (struct in6_addr*)&xfrm[i]->props.saddr.a6); break; #endif 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; *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; x->u.rt.fl = *fl; 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 = 0; dst_prev->trailer_len = trailer_len; memcpy(&dst_prev->metrics, &x->route->metrics, sizeof(dst_prev->metrics)); /* Copy neighbout for reachability confirmation */ dst_prev->neighbour = neigh_clone(rt->u.dst.neighbour); dst_prev->input = rt->u.dst.input; /* XXX: When IPv6 module can be unloaded, we should manage reference * to xfrm6_output in afinfo->output. Miyazawa * */ afinfo = xfrm_state_get_afinfo(dst_prev->xfrm->props.family); if (!afinfo) { dst = *dst_p; err = -EAFNOSUPPORT; goto error; } dst_prev->output = afinfo->output; xfrm_state_put_afinfo(afinfo); if (dst_prev->xfrm->props.family == AF_INET && rt->peer) atomic_inc(&rt->peer->refcnt); x->u.rt.peer = rt->peer; /* Sheit... I remember I did this right. Apparently, * it was magically lost, so this code needs audit */ x->u.rt.rt_flags = rt0->rt_flags&(RTCF_BROADCAST|RTCF_MULTICAST|RTCF_LOCAL); x->u.rt.rt_type = rt->rt_type; x->u.rt.rt_src = rt0->rt_src; x->u.rt.rt_dst = rt0->rt_dst; x->u.rt.rt_gateway = rt->rt_gateway; x->u.rt.rt_spec_dst = rt0->rt_spec_dst; x->u.rt.idev = rt0->idev; in_dev_hold(rt0->idev); header_len -= x->u.dst.xfrm->props.header_len; trailer_len -= x->u.dst.xfrm->props.trailer_len; } xfrm_init_pmtu(dst); return 0; error: if (dst) dst_free(dst); return err; } static void _decode_session4(struct sk_buff *skb, struct flowi *fl) { struct iphdr *iph = ip_hdr(skb); u8 *xprth = skb_network_header(skb) + iph->ihl * 4; memset(fl, 0, sizeof(struct flowi)); if (!(iph->frag_off & htons(IP_MF | IP_OFFSET))) { switch (iph->protocol) { case IPPROTO_UDP: case IPPROTO_UDPLITE: case IPPROTO_TCP: case IPPROTO_SCTP: case IPPROTO_DCCP: if (pskb_may_pull(skb, xprth + 4 - skb->data)) { __be16 *ports = (__be16 *)xprth; fl->fl_ip_sport = ports[0]; fl->fl_ip_dport = ports[1]; } break; case IPPROTO_ICMP: if (pskb_may_pull(skb, xprth + 2 - skb->data)) { u8 *icmp = xprth; fl->fl_icmp_type = icmp[0]; fl->fl_icmp_code = icmp[1]; } break; case IPPROTO_ESP: if (pskb_may_pull(skb, xprth + 4 - skb->data)) { __be32 *ehdr = (__be32 *)xprth; fl->fl_ipsec_spi = ehdr[0]; } break; case IPPROTO_AH: if (pskb_may_pull(skb, xprth + 8 - skb->data)) { __be32 *ah_hdr = (__be32*)xprth; fl->fl_ipsec_spi = ah_hdr[1]; } break; case IPPROTO_COMP: if (pskb_may_pull(skb, xprth + 4 - skb->data)) { __be16 *ipcomp_hdr = (__be16 *)xprth; fl->fl_ipsec_spi = htonl(ntohs(ipcomp_hdr[1])); } break; default: fl->fl_ipsec_spi = 0; break; } } fl->proto = iph->protocol; fl->fl4_dst = iph->daddr; fl->fl4_src = iph->saddr; fl->fl4_tos = iph->tos; } static inline int xfrm4_garbage_collect(void) { xfrm4_policy_afinfo.garbage_collect(); return (atomic_read(&xfrm4_dst_ops.entries) > xfrm4_dst_ops.gc_thresh*2); } static void xfrm4_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 xfrm4_dst_destroy(struct dst_entry *dst) { struct xfrm_dst *xdst = (struct xfrm_dst *)dst; if (likely(xdst->u.rt.idev)) in_dev_put(xdst->u.rt.idev); if (dst->xfrm && dst->xfrm->props.family == AF_INET && likely(xdst->u.rt.peer)) inet_putpeer(xdst->u.rt.peer); xfrm_dst_destroy(xdst); } static void xfrm4_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.rt.idev->dev == dev) { struct in_device *loopback_idev = in_dev_get(&loopback_dev); BUG_ON(!loopback_idev); do { in_dev_put(xdst->u.rt.idev); xdst->u.rt.idev = loopback_idev; in_dev_hold(loopback_idev); xdst = (struct xfrm_dst *)xdst->u.dst.child; } while (xdst->u.dst.xfrm); __in_dev_put(loopback_idev); } xfrm_dst_ifdown(dst, dev); } static struct dst_ops xfrm4_dst_ops = { .family = AF_INET, .protocol = __constant_htons(ETH_P_IP), .gc = xfrm4_garbage_collect, .update_pmtu = xfrm4_update_pmtu, .destroy = xfrm4_dst_destroy, .ifdown = xfrm4_dst_ifdown, .gc_thresh = 1024, .entry_size = sizeof(struct xfrm_dst), }; static struct xfrm_policy_afinfo xfrm4_policy_afinfo = { .family = AF_INET, .dst_ops = &xfrm4_dst_ops, .dst_lookup = xfrm4_dst_lookup, .get_saddr = xfrm4_get_saddr, .find_bundle = __xfrm4_find_bundle, .bundle_create = __xfrm4_bundle_create, .decode_session = _decode_session4, }; static void __init xfrm4_policy_init(void) { xfrm_policy_register_afinfo(&xfrm4_policy_afinfo); } static void __exit xfrm4_policy_fini(void) { xfrm_policy_unregister_afinfo(&xfrm4_policy_afinfo); } void __init xfrm4_init(void) { xfrm4_state_init(); xfrm4_policy_init(); }