11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * xfrm4_policy.c 31da177e4SLinus Torvalds * 41da177e4SLinus Torvalds * Changes: 51da177e4SLinus Torvalds * Kazunori MIYAZAWA @USAGI 61da177e4SLinus Torvalds * YOSHIFUJI Hideaki @USAGI 71da177e4SLinus Torvalds * Split up af-specific portion 81da177e4SLinus Torvalds * 91da177e4SLinus Torvalds */ 101da177e4SLinus Torvalds 1166cdb3caSHerbert Xu #include <linux/err.h> 1266cdb3caSHerbert Xu #include <linux/kernel.h> 13aabc9761SHerbert Xu #include <linux/inetdevice.h> 1445ff5a3fSHerbert Xu #include <net/dst.h> 151da177e4SLinus Torvalds #include <net/xfrm.h> 161da177e4SLinus Torvalds #include <net/ip.h> 171da177e4SLinus Torvalds 181da177e4SLinus Torvalds static struct dst_ops xfrm4_dst_ops; 191da177e4SLinus Torvalds static struct xfrm_policy_afinfo xfrm4_policy_afinfo; 201da177e4SLinus Torvalds 21*c5b3cf46SAlexey Dobriyan static struct dst_entry *xfrm4_dst_lookup(struct net *net, int tos, 22*c5b3cf46SAlexey Dobriyan xfrm_address_t *saddr, 2366cdb3caSHerbert Xu xfrm_address_t *daddr) 241da177e4SLinus Torvalds { 2566cdb3caSHerbert Xu struct flowi fl = { 26a1e59abfSPatrick McHardy .nl_u = { 27a1e59abfSPatrick McHardy .ip4_u = { 2866cdb3caSHerbert Xu .tos = tos, 29a1e59abfSPatrick McHardy .daddr = daddr->a4, 30a1e59abfSPatrick McHardy }, 31a1e59abfSPatrick McHardy }, 32a1e59abfSPatrick McHardy }; 3366cdb3caSHerbert Xu struct dst_entry *dst; 3466cdb3caSHerbert Xu struct rtable *rt; 3566cdb3caSHerbert Xu int err; 36a1e59abfSPatrick McHardy 3766cdb3caSHerbert Xu if (saddr) 3866cdb3caSHerbert Xu fl.fl4_src = saddr->a4; 3966cdb3caSHerbert Xu 40*c5b3cf46SAlexey Dobriyan err = __ip_route_output_key(net, &rt, &fl); 4166cdb3caSHerbert Xu dst = &rt->u.dst; 4266cdb3caSHerbert Xu if (err) 4366cdb3caSHerbert Xu dst = ERR_PTR(err); 4466cdb3caSHerbert Xu return dst; 45a1e59abfSPatrick McHardy } 4666cdb3caSHerbert Xu 4766cdb3caSHerbert Xu static int xfrm4_get_saddr(xfrm_address_t *saddr, xfrm_address_t *daddr) 4866cdb3caSHerbert Xu { 4966cdb3caSHerbert Xu struct dst_entry *dst; 5066cdb3caSHerbert Xu struct rtable *rt; 5166cdb3caSHerbert Xu 52*c5b3cf46SAlexey Dobriyan dst = xfrm4_dst_lookup(&init_net, 0, NULL, daddr); 5366cdb3caSHerbert Xu if (IS_ERR(dst)) 54a1e59abfSPatrick McHardy return -EHOSTUNREACH; 5566cdb3caSHerbert Xu 5666cdb3caSHerbert Xu rt = (struct rtable *)dst; 5766cdb3caSHerbert Xu saddr->a4 = rt->rt_src; 5866cdb3caSHerbert Xu dst_release(dst); 5966cdb3caSHerbert Xu return 0; 60a1e59abfSPatrick McHardy } 61a1e59abfSPatrick McHardy 621da177e4SLinus Torvalds static struct dst_entry * 631da177e4SLinus Torvalds __xfrm4_find_bundle(struct flowi *fl, struct xfrm_policy *policy) 641da177e4SLinus Torvalds { 651da177e4SLinus Torvalds struct dst_entry *dst; 661da177e4SLinus Torvalds 671da177e4SLinus Torvalds read_lock_bh(&policy->lock); 681da177e4SLinus Torvalds for (dst = policy->bundles; dst; dst = dst->next) { 691da177e4SLinus Torvalds struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 701da177e4SLinus Torvalds if (xdst->u.rt.fl.oif == fl->oif && /*XXX*/ 711da177e4SLinus Torvalds xdst->u.rt.fl.fl4_dst == fl->fl4_dst && 721da177e4SLinus Torvalds xdst->u.rt.fl.fl4_src == fl->fl4_src && 734da3089fSHerbert Xu xdst->u.rt.fl.fl4_tos == fl->fl4_tos && 745b368e61SVenkat Yekkirala xfrm_bundle_ok(policy, xdst, fl, AF_INET, 0)) { 751da177e4SLinus Torvalds dst_clone(dst); 761da177e4SLinus Torvalds break; 771da177e4SLinus Torvalds } 781da177e4SLinus Torvalds } 791da177e4SLinus Torvalds read_unlock_bh(&policy->lock); 801da177e4SLinus Torvalds return dst; 811da177e4SLinus Torvalds } 821da177e4SLinus Torvalds 8325ee3286SHerbert Xu static int xfrm4_get_tos(struct flowi *fl) 841da177e4SLinus Torvalds { 8525ee3286SHerbert Xu return fl->fl4_tos; 861da177e4SLinus Torvalds } 871da177e4SLinus Torvalds 88a1b05140SMasahide NAKAMURA static int xfrm4_init_path(struct xfrm_dst *path, struct dst_entry *dst, 89a1b05140SMasahide NAKAMURA int nfheader_len) 90a1b05140SMasahide NAKAMURA { 91a1b05140SMasahide NAKAMURA return 0; 92a1b05140SMasahide NAKAMURA } 93a1b05140SMasahide NAKAMURA 9425ee3286SHerbert Xu static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev) 9525ee3286SHerbert Xu { 9625ee3286SHerbert Xu struct rtable *rt = (struct rtable *)xdst->route; 971da177e4SLinus Torvalds 9825ee3286SHerbert Xu xdst->u.rt.fl = rt->fl; 991da177e4SLinus Torvalds 10025ee3286SHerbert Xu xdst->u.dst.dev = dev; 10125ee3286SHerbert Xu dev_hold(dev); 10243372262SMiika Komu 10325ee3286SHerbert Xu xdst->u.rt.idev = in_dev_get(dev); 10425ee3286SHerbert Xu if (!xdst->u.rt.idev) 10525ee3286SHerbert Xu return -ENODEV; 1061da177e4SLinus Torvalds 10725ee3286SHerbert Xu xdst->u.rt.peer = rt->peer; 10825ee3286SHerbert Xu if (rt->peer) 10925ee3286SHerbert Xu atomic_inc(&rt->peer->refcnt); 11066cdb3caSHerbert Xu 1111da177e4SLinus Torvalds /* Sheit... I remember I did this right. Apparently, 1121da177e4SLinus Torvalds * it was magically lost, so this code needs audit */ 11325ee3286SHerbert Xu xdst->u.rt.rt_flags = rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | 11425ee3286SHerbert Xu RTCF_LOCAL); 11525ee3286SHerbert Xu xdst->u.rt.rt_type = rt->rt_type; 11625ee3286SHerbert Xu xdst->u.rt.rt_src = rt->rt_src; 11725ee3286SHerbert Xu xdst->u.rt.rt_dst = rt->rt_dst; 11825ee3286SHerbert Xu xdst->u.rt.rt_gateway = rt->rt_gateway; 11925ee3286SHerbert Xu xdst->u.rt.rt_spec_dst = rt->rt_spec_dst; 1201da177e4SLinus Torvalds 1211da177e4SLinus Torvalds return 0; 1221da177e4SLinus Torvalds } 1231da177e4SLinus Torvalds 1241da177e4SLinus Torvalds static void 125d5422efeSHerbert Xu _decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) 1261da177e4SLinus Torvalds { 127eddc9ec5SArnaldo Carvalho de Melo struct iphdr *iph = ip_hdr(skb); 128d56f90a7SArnaldo Carvalho de Melo u8 *xprth = skb_network_header(skb) + iph->ihl * 4; 1291da177e4SLinus Torvalds 1301da177e4SLinus Torvalds memset(fl, 0, sizeof(struct flowi)); 1311da177e4SLinus Torvalds if (!(iph->frag_off & htons(IP_MF | IP_OFFSET))) { 1321da177e4SLinus Torvalds switch (iph->protocol) { 1331da177e4SLinus Torvalds case IPPROTO_UDP: 134ba4e58ecSGerrit Renker case IPPROTO_UDPLITE: 1351da177e4SLinus Torvalds case IPPROTO_TCP: 1361da177e4SLinus Torvalds case IPPROTO_SCTP: 1379e999993SPatrick McHardy case IPPROTO_DCCP: 1381da177e4SLinus Torvalds if (pskb_may_pull(skb, xprth + 4 - skb->data)) { 1398c689a6eSAl Viro __be16 *ports = (__be16 *)xprth; 1401da177e4SLinus Torvalds 141d5422efeSHerbert Xu fl->fl_ip_sport = ports[!!reverse]; 142d5422efeSHerbert Xu fl->fl_ip_dport = ports[!reverse]; 1431da177e4SLinus Torvalds } 1441da177e4SLinus Torvalds break; 1451da177e4SLinus Torvalds 1461da177e4SLinus Torvalds case IPPROTO_ICMP: 1471da177e4SLinus Torvalds if (pskb_may_pull(skb, xprth + 2 - skb->data)) { 1481da177e4SLinus Torvalds u8 *icmp = xprth; 1491da177e4SLinus Torvalds 1501da177e4SLinus Torvalds fl->fl_icmp_type = icmp[0]; 1511da177e4SLinus Torvalds fl->fl_icmp_code = icmp[1]; 1521da177e4SLinus Torvalds } 1531da177e4SLinus Torvalds break; 1541da177e4SLinus Torvalds 1551da177e4SLinus Torvalds case IPPROTO_ESP: 1561da177e4SLinus Torvalds if (pskb_may_pull(skb, xprth + 4 - skb->data)) { 1574324a174SAl Viro __be32 *ehdr = (__be32 *)xprth; 1581da177e4SLinus Torvalds 1591da177e4SLinus Torvalds fl->fl_ipsec_spi = ehdr[0]; 1601da177e4SLinus Torvalds } 1611da177e4SLinus Torvalds break; 1621da177e4SLinus Torvalds 1631da177e4SLinus Torvalds case IPPROTO_AH: 1641da177e4SLinus Torvalds if (pskb_may_pull(skb, xprth + 8 - skb->data)) { 1654324a174SAl Viro __be32 *ah_hdr = (__be32*)xprth; 1661da177e4SLinus Torvalds 1671da177e4SLinus Torvalds fl->fl_ipsec_spi = ah_hdr[1]; 1681da177e4SLinus Torvalds } 1691da177e4SLinus Torvalds break; 1701da177e4SLinus Torvalds 1711da177e4SLinus Torvalds case IPPROTO_COMP: 1721da177e4SLinus Torvalds if (pskb_may_pull(skb, xprth + 4 - skb->data)) { 1734324a174SAl Viro __be16 *ipcomp_hdr = (__be16 *)xprth; 1741da177e4SLinus Torvalds 1754195f814SAlexey Dobriyan fl->fl_ipsec_spi = htonl(ntohs(ipcomp_hdr[1])); 1761da177e4SLinus Torvalds } 1771da177e4SLinus Torvalds break; 1781da177e4SLinus Torvalds default: 1791da177e4SLinus Torvalds fl->fl_ipsec_spi = 0; 1801da177e4SLinus Torvalds break; 1813ff50b79SStephen Hemminger } 1821da177e4SLinus Torvalds } 1831da177e4SLinus Torvalds fl->proto = iph->protocol; 184d5422efeSHerbert Xu fl->fl4_dst = reverse ? iph->saddr : iph->daddr; 185d5422efeSHerbert Xu fl->fl4_src = reverse ? iph->daddr : iph->saddr; 1864da3089fSHerbert Xu fl->fl4_tos = iph->tos; 1871da177e4SLinus Torvalds } 1881da177e4SLinus Torvalds 189569d3645SDaniel Lezcano static inline int xfrm4_garbage_collect(struct dst_ops *ops) 1901da177e4SLinus Torvalds { 191ddcfd796SAlexey Dobriyan xfrm4_policy_afinfo.garbage_collect(&init_net); 1921da177e4SLinus Torvalds return (atomic_read(&xfrm4_dst_ops.entries) > xfrm4_dst_ops.gc_thresh*2); 1931da177e4SLinus Torvalds } 1941da177e4SLinus Torvalds 1951da177e4SLinus Torvalds static void xfrm4_update_pmtu(struct dst_entry *dst, u32 mtu) 1961da177e4SLinus Torvalds { 1971da177e4SLinus Torvalds struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 1981da177e4SLinus Torvalds struct dst_entry *path = xdst->route; 1991da177e4SLinus Torvalds 2001da177e4SLinus Torvalds path->ops->update_pmtu(path, mtu); 2011da177e4SLinus Torvalds } 2021da177e4SLinus Torvalds 203aabc9761SHerbert Xu static void xfrm4_dst_destroy(struct dst_entry *dst) 204aabc9761SHerbert Xu { 205aabc9761SHerbert Xu struct xfrm_dst *xdst = (struct xfrm_dst *)dst; 206aabc9761SHerbert Xu 207aabc9761SHerbert Xu if (likely(xdst->u.rt.idev)) 208aabc9761SHerbert Xu in_dev_put(xdst->u.rt.idev); 209ed3e37ddSHerbert Xu if (likely(xdst->u.rt.peer)) 21026db1677SDavid S. Miller inet_putpeer(xdst->u.rt.peer); 211aabc9761SHerbert Xu xfrm_dst_destroy(xdst); 212aabc9761SHerbert Xu } 213aabc9761SHerbert Xu 214aabc9761SHerbert Xu static void xfrm4_dst_ifdown(struct dst_entry *dst, struct net_device *dev, 215aabc9761SHerbert Xu int unregister) 216aabc9761SHerbert Xu { 217aabc9761SHerbert Xu struct xfrm_dst *xdst; 218aabc9761SHerbert Xu 219aabc9761SHerbert Xu if (!unregister) 220aabc9761SHerbert Xu return; 221aabc9761SHerbert Xu 222aabc9761SHerbert Xu xdst = (struct xfrm_dst *)dst; 223aabc9761SHerbert Xu if (xdst->u.rt.idev->dev == dev) { 2245a3e55d6SDenis V. Lunev struct in_device *loopback_idev = 225c346dca1SYOSHIFUJI Hideaki in_dev_get(dev_net(dev)->loopback_dev); 226aabc9761SHerbert Xu BUG_ON(!loopback_idev); 227aabc9761SHerbert Xu 228aabc9761SHerbert Xu do { 229aabc9761SHerbert Xu in_dev_put(xdst->u.rt.idev); 230aabc9761SHerbert Xu xdst->u.rt.idev = loopback_idev; 231aabc9761SHerbert Xu in_dev_hold(loopback_idev); 232aabc9761SHerbert Xu xdst = (struct xfrm_dst *)xdst->u.dst.child; 233aabc9761SHerbert Xu } while (xdst->u.dst.xfrm); 234aabc9761SHerbert Xu 235aabc9761SHerbert Xu __in_dev_put(loopback_idev); 236aabc9761SHerbert Xu } 237aabc9761SHerbert Xu 238aabc9761SHerbert Xu xfrm_dst_ifdown(dst, dev); 239aabc9761SHerbert Xu } 240aabc9761SHerbert Xu 2411da177e4SLinus Torvalds static struct dst_ops xfrm4_dst_ops = { 2421da177e4SLinus Torvalds .family = AF_INET, 2431da177e4SLinus Torvalds .protocol = __constant_htons(ETH_P_IP), 2441da177e4SLinus Torvalds .gc = xfrm4_garbage_collect, 2451da177e4SLinus Torvalds .update_pmtu = xfrm4_update_pmtu, 246aabc9761SHerbert Xu .destroy = xfrm4_dst_destroy, 247aabc9761SHerbert Xu .ifdown = xfrm4_dst_ifdown, 248862b82c6SHerbert Xu .local_out = __ip_local_out, 2491da177e4SLinus Torvalds .gc_thresh = 1024, 250e2422970SEric Dumazet .entries = ATOMIC_INIT(0), 2511da177e4SLinus Torvalds }; 2521da177e4SLinus Torvalds 2531da177e4SLinus Torvalds static struct xfrm_policy_afinfo xfrm4_policy_afinfo = { 2541da177e4SLinus Torvalds .family = AF_INET, 2551da177e4SLinus Torvalds .dst_ops = &xfrm4_dst_ops, 2561da177e4SLinus Torvalds .dst_lookup = xfrm4_dst_lookup, 257a1e59abfSPatrick McHardy .get_saddr = xfrm4_get_saddr, 2581da177e4SLinus Torvalds .find_bundle = __xfrm4_find_bundle, 2591da177e4SLinus Torvalds .decode_session = _decode_session4, 26025ee3286SHerbert Xu .get_tos = xfrm4_get_tos, 261a1b05140SMasahide NAKAMURA .init_path = xfrm4_init_path, 26225ee3286SHerbert Xu .fill_dst = xfrm4_fill_dst, 2631da177e4SLinus Torvalds }; 2641da177e4SLinus Torvalds 2651da177e4SLinus Torvalds static void __init xfrm4_policy_init(void) 2661da177e4SLinus Torvalds { 2671da177e4SLinus Torvalds xfrm_policy_register_afinfo(&xfrm4_policy_afinfo); 2681da177e4SLinus Torvalds } 2691da177e4SLinus Torvalds 2701da177e4SLinus Torvalds static void __exit xfrm4_policy_fini(void) 2711da177e4SLinus Torvalds { 2721da177e4SLinus Torvalds xfrm_policy_unregister_afinfo(&xfrm4_policy_afinfo); 2731da177e4SLinus Torvalds } 2741da177e4SLinus Torvalds 2751da177e4SLinus Torvalds void __init xfrm4_init(void) 2761da177e4SLinus Torvalds { 2771da177e4SLinus Torvalds xfrm4_state_init(); 2781da177e4SLinus Torvalds xfrm4_policy_init(); 2791da177e4SLinus Torvalds } 2801da177e4SLinus Torvalds 281