diff options
Diffstat (limited to 'net/ipv4/xfrm4_policy.c')
| -rw-r--r-- | net/ipv4/xfrm4_policy.c | 281 |
1 files changed, 281 insertions, 0 deletions
diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c new file mode 100644 index 00000000000..7fe2afd2e66 --- /dev/null +++ b/net/ipv4/xfrm4_policy.c @@ -0,0 +1,281 @@ +/* + * xfrm4_policy.c + * + * Changes: + * Kazunori MIYAZAWA @USAGI + * YOSHIFUJI Hideaki @USAGI + * Split up af-specific portion + * + */ + +#include <linux/config.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 xfrm_type_map xfrm4_type_map = { .lock = RW_LOCK_UNLOCKED }; + +static int xfrm4_dst_lookup(struct xfrm_dst **dst, struct flowi *fl) +{ + return __ip_route_output_key((struct rtable**)dst, fl); +} + +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 && + xfrm_bundle_ok(xdst, fl, AF_INET)) { + 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; + u32 remote = fl->fl4_dst; + u32 local = fl->fl4_src; + struct flowi fl_tunnel = { + .nl_u = { + .ip4_u = { + .saddr = local, + .daddr = remote + } + } + }; + 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; + int tunnel = 0; + + 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; + + dst1->next = dst_prev; + dst_prev = dst1; + if (xfrm[i]->props.mode) { + remote = xfrm[i]->id.daddr.a4; + local = xfrm[i]->props.saddr.a4; + tunnel = 1; + } + header_len += xfrm[i]->props.header_len; + trailer_len += xfrm[i]->props.trailer_len; + + if (tunnel) { + fl_tunnel.fl4_src = local; + fl_tunnel.fl4_dst = remote; + err = xfrm_dst_lookup((struct xfrm_dst **)&rt, + &fl_tunnel, AF_INET); + 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; + 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->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; + dst_prev->output = xfrm4_output; + if (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; + 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 = skb->nh.iph; + u8 *xprth = skb->nh.raw + 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_TCP: + case IPPROTO_SCTP: + if (pskb_may_pull(skb, xprth + 4 - skb->data)) { + u16 *ports = (u16 *)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)) { + u32 *ehdr = (u32 *)xprth; + + fl->fl_ipsec_spi = ehdr[0]; + } + break; + + case IPPROTO_AH: + if (pskb_may_pull(skb, xprth + 8 - skb->data)) { + u32 *ah_hdr = (u32*)xprth; + + fl->fl_ipsec_spi = ah_hdr[1]; + } + break; + + case IPPROTO_COMP: + if (pskb_may_pull(skb, xprth + 4 - skb->data)) { + u16 *ipcomp_hdr = (u16 *)xprth; + + fl->fl_ipsec_spi = ntohl(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; +} + +static inline int xfrm4_garbage_collect(void) +{ + read_lock(&xfrm4_policy_afinfo.lock); + xfrm4_policy_afinfo.garbage_collect(); + read_unlock(&xfrm4_policy_afinfo.lock); + 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 struct dst_ops xfrm4_dst_ops = { + .family = AF_INET, + .protocol = __constant_htons(ETH_P_IP), + .gc = xfrm4_garbage_collect, + .update_pmtu = xfrm4_update_pmtu, + .gc_thresh = 1024, + .entry_size = sizeof(struct xfrm_dst), +}; + +static struct xfrm_policy_afinfo xfrm4_policy_afinfo = { + .family = AF_INET, + .lock = RW_LOCK_UNLOCKED, + .type_map = &xfrm4_type_map, + .dst_ops = &xfrm4_dst_ops, + .dst_lookup = xfrm4_dst_lookup, + .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(); +} + |