diff options
Diffstat (limited to 'net/ipv4/xfrm4_policy.c')
-rw-r--r-- | net/ipv4/xfrm4_policy.c | 280 |
1 files changed, 280 insertions, 0 deletions
diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c new file mode 100644 index 0000000..c63de0a --- /dev/null +++ b/net/ipv4/xfrm4_policy.c @@ -0,0 +1,280 @@ +/* + * xfrm4_policy.c + * + * Changes: + * Kazunori MIYAZAWA @USAGI + * YOSHIFUJI Hideaki @USAGI + * Split up af-specific portion + * + */ + +#include <linux/err.h> +#include <linux/kernel.h> +#include <linux/inetdevice.h> +#include <net/dst.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 struct dst_entry *xfrm4_dst_lookup(int tos, xfrm_address_t *saddr, + xfrm_address_t *daddr) +{ + struct flowi fl = { + .nl_u = { + .ip4_u = { + .tos = tos, + .daddr = daddr->a4, + }, + }, + }; + struct dst_entry *dst; + struct rtable *rt; + int err; + + if (saddr) + fl.fl4_src = saddr->a4; + + err = __ip_route_output_key(&init_net, &rt, &fl); + dst = &rt->u.dst; + if (err) + dst = ERR_PTR(err); + return dst; +} + +static int xfrm4_get_saddr(xfrm_address_t *saddr, xfrm_address_t *daddr) +{ + struct dst_entry *dst; + struct rtable *rt; + + dst = xfrm4_dst_lookup(0, NULL, daddr); + if (IS_ERR(dst)) + return -EHOSTUNREACH; + + rt = (struct rtable *)dst; + saddr->a4 = rt->rt_src; + dst_release(dst); + return 0; +} + +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; +} + +static int xfrm4_get_tos(struct flowi *fl) +{ + return fl->fl4_tos; +} + +static int xfrm4_init_path(struct xfrm_dst *path, struct dst_entry *dst, + int nfheader_len) +{ + return 0; +} + +static int xfrm4_fill_dst(struct xfrm_dst *xdst, struct net_device *dev) +{ + struct rtable *rt = (struct rtable *)xdst->route; + + xdst->u.rt.fl = rt->fl; + + xdst->u.dst.dev = dev; + dev_hold(dev); + + xdst->u.rt.idev = in_dev_get(dev); + if (!xdst->u.rt.idev) + return -ENODEV; + + xdst->u.rt.peer = rt->peer; + if (rt->peer) + atomic_inc(&rt->peer->refcnt); + + /* Sheit... I remember I did this right. Apparently, + * it was magically lost, so this code needs audit */ + xdst->u.rt.rt_flags = rt->rt_flags & (RTCF_BROADCAST | RTCF_MULTICAST | + RTCF_LOCAL); + xdst->u.rt.rt_type = rt->rt_type; + xdst->u.rt.rt_src = rt->rt_src; + xdst->u.rt.rt_dst = rt->rt_dst; + xdst->u.rt.rt_gateway = rt->rt_gateway; + xdst->u.rt.rt_spec_dst = rt->rt_spec_dst; + + return 0; +} + +static void +_decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) +{ + 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[!!reverse]; + fl->fl_ip_dport = ports[!reverse]; + } + 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 = reverse ? iph->saddr : iph->daddr; + fl->fl4_src = reverse ? iph->daddr : iph->saddr; + fl->fl4_tos = iph->tos; +} + +static inline int xfrm4_garbage_collect(struct dst_ops *ops) +{ + 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 (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(dev_net(dev)->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, + .local_out = __ip_local_out, + .gc_thresh = 1024, + .entry_size = sizeof(struct xfrm_dst), + .entries = ATOMIC_INIT(0), +}; + +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, + .decode_session = _decode_session4, + .get_tos = xfrm4_get_tos, + .init_path = xfrm4_init_path, + .fill_dst = xfrm4_fill_dst, +}; + +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(); +} + |