From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- net/ipv4/xfrm4_policy.c | 332 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 332 insertions(+) create mode 100644 net/ipv4/xfrm4_policy.c (limited to 'net/ipv4/xfrm4_policy.c') diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c new file mode 100644 index 000000000..bff69746e --- /dev/null +++ b/net/ipv4/xfrm4_policy.c @@ -0,0 +1,332 @@ +/* + * xfrm4_policy.c + * + * Changes: + * Kazunori MIYAZAWA @USAGI + * YOSHIFUJI Hideaki @USAGI + * Split up af-specific portion + * + */ + +#include +#include +#include +#include +#include +#include +#include + +static struct xfrm_policy_afinfo xfrm4_policy_afinfo; + +static struct dst_entry *__xfrm4_dst_lookup(struct net *net, struct flowi4 *fl4, + int tos, + const xfrm_address_t *saddr, + const xfrm_address_t *daddr) +{ + struct rtable *rt; + + memset(fl4, 0, sizeof(*fl4)); + fl4->daddr = daddr->a4; + fl4->flowi4_tos = tos; + if (saddr) + fl4->saddr = saddr->a4; + + rt = __ip_route_output_key(net, fl4); + if (!IS_ERR(rt)) + return &rt->dst; + + return ERR_CAST(rt); +} + +static struct dst_entry *xfrm4_dst_lookup(struct net *net, int tos, + const xfrm_address_t *saddr, + const xfrm_address_t *daddr) +{ + struct flowi4 fl4; + + return __xfrm4_dst_lookup(net, &fl4, tos, saddr, daddr); +} + +static int xfrm4_get_saddr(struct net *net, + xfrm_address_t *saddr, xfrm_address_t *daddr) +{ + struct dst_entry *dst; + struct flowi4 fl4; + + dst = __xfrm4_dst_lookup(net, &fl4, 0, NULL, daddr); + if (IS_ERR(dst)) + return -EHOSTUNREACH; + + saddr->a4 = fl4.saddr; + dst_release(dst); + return 0; +} + +static int xfrm4_get_tos(const struct flowi *fl) +{ + return IPTOS_RT_MASK & fl->u.ip4.flowi4_tos; /* Strip ECN bits */ +} + +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, + const struct flowi *fl) +{ + struct rtable *rt = (struct rtable *)xdst->route; + const struct flowi4 *fl4 = &fl->u.ip4; + + xdst->u.rt.rt_iif = fl4->flowi4_iif; + + xdst->u.dst.dev = dev; + dev_hold(dev); + + /* Sheit... I remember I did this right. Apparently, + * it was magically lost, so this code needs audit */ + xdst->u.rt.rt_is_input = rt->rt_is_input; + 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_gateway = rt->rt_gateway; + xdst->u.rt.rt_uses_gateway = rt->rt_uses_gateway; + xdst->u.rt.rt_pmtu = rt->rt_pmtu; + INIT_LIST_HEAD(&xdst->u.rt.rt_uncached); + + return 0; +} + +static void +_decode_session4(struct sk_buff *skb, struct flowi *fl, int reverse) +{ + const struct iphdr *iph = ip_hdr(skb); + u8 *xprth = skb_network_header(skb) + iph->ihl * 4; + struct flowi4 *fl4 = &fl->u.ip4; + int oif = 0; + + if (skb_dst(skb)) + oif = skb_dst(skb)->dev->ifindex; + + memset(fl4, 0, sizeof(struct flowi4)); + fl4->flowi4_mark = skb->mark; + fl4->flowi4_oif = reverse ? skb->skb_iif : oif; + + if (!ip_is_fragment(iph)) { + switch (iph->protocol) { + case IPPROTO_UDP: + case IPPROTO_UDPLITE: + case IPPROTO_TCP: + case IPPROTO_SCTP: + case IPPROTO_DCCP: + if (xprth + 4 < skb->data || + pskb_may_pull(skb, xprth + 4 - skb->data)) { + __be16 *ports = (__be16 *)xprth; + + fl4->fl4_sport = ports[!!reverse]; + fl4->fl4_dport = ports[!reverse]; + } + break; + + case IPPROTO_ICMP: + if (pskb_may_pull(skb, xprth + 2 - skb->data)) { + u8 *icmp = xprth; + + fl4->fl4_icmp_type = icmp[0]; + fl4->fl4_icmp_code = icmp[1]; + } + break; + + case IPPROTO_ESP: + if (pskb_may_pull(skb, xprth + 4 - skb->data)) { + __be32 *ehdr = (__be32 *)xprth; + + fl4->fl4_ipsec_spi = ehdr[0]; + } + break; + + case IPPROTO_AH: + if (pskb_may_pull(skb, xprth + 8 - skb->data)) { + __be32 *ah_hdr = (__be32 *)xprth; + + fl4->fl4_ipsec_spi = ah_hdr[1]; + } + break; + + case IPPROTO_COMP: + if (pskb_may_pull(skb, xprth + 4 - skb->data)) { + __be16 *ipcomp_hdr = (__be16 *)xprth; + + fl4->fl4_ipsec_spi = htonl(ntohs(ipcomp_hdr[1])); + } + break; + + case IPPROTO_GRE: + if (pskb_may_pull(skb, xprth + 12 - skb->data)) { + __be16 *greflags = (__be16 *)xprth; + __be32 *gre_hdr = (__be32 *)xprth; + + if (greflags[0] & GRE_KEY) { + if (greflags[0] & GRE_CSUM) + gre_hdr++; + fl4->fl4_gre_key = gre_hdr[1]; + } + } + break; + + default: + fl4->fl4_ipsec_spi = 0; + break; + } + } + fl4->flowi4_proto = iph->protocol; + fl4->daddr = reverse ? iph->saddr : iph->daddr; + fl4->saddr = reverse ? iph->daddr : iph->saddr; + fl4->flowi4_tos = iph->tos; +} + +static inline int xfrm4_garbage_collect(struct dst_ops *ops) +{ + struct net *net = container_of(ops, struct net, xfrm.xfrm4_dst_ops); + + xfrm4_policy_afinfo.garbage_collect(net); + return (dst_entries_get_slow(ops) > ops->gc_thresh * 2); +} + +static void xfrm4_update_pmtu(struct dst_entry *dst, struct sock *sk, + struct sk_buff *skb, u32 mtu) +{ + struct xfrm_dst *xdst = (struct xfrm_dst *)dst; + struct dst_entry *path = xdst->route; + + path->ops->update_pmtu(path, sk, skb, mtu); +} + +static void xfrm4_redirect(struct dst_entry *dst, struct sock *sk, + struct sk_buff *skb) +{ + struct xfrm_dst *xdst = (struct xfrm_dst *)dst; + struct dst_entry *path = xdst->route; + + path->ops->redirect(path, sk, skb); +} + +static void xfrm4_dst_destroy(struct dst_entry *dst) +{ + struct xfrm_dst *xdst = (struct xfrm_dst *)dst; + + dst_destroy_metrics_generic(dst); + + xfrm_dst_destroy(xdst); +} + +static void xfrm4_dst_ifdown(struct dst_entry *dst, struct net_device *dev, + int unregister) +{ + if (!unregister) + return; + + xfrm_dst_ifdown(dst, dev); +} + +static struct dst_ops xfrm4_dst_ops = { + .family = AF_INET, + .gc = xfrm4_garbage_collect, + .update_pmtu = xfrm4_update_pmtu, + .redirect = xfrm4_redirect, + .cow_metrics = dst_cow_metrics_generic, + .destroy = xfrm4_dst_destroy, + .ifdown = xfrm4_dst_ifdown, + .local_out = __ip_local_out, + .gc_thresh = 32768, +}; + +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, + .decode_session = _decode_session4, + .get_tos = xfrm4_get_tos, + .init_path = xfrm4_init_path, + .fill_dst = xfrm4_fill_dst, + .blackhole_route = ipv4_blackhole_route, +}; + +#ifdef CONFIG_SYSCTL +static struct ctl_table xfrm4_policy_table[] = { + { + .procname = "xfrm4_gc_thresh", + .data = &init_net.xfrm.xfrm4_dst_ops.gc_thresh, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { } +}; + +static int __net_init xfrm4_net_init(struct net *net) +{ + struct ctl_table *table; + struct ctl_table_header *hdr; + + table = xfrm4_policy_table; + if (!net_eq(net, &init_net)) { + table = kmemdup(table, sizeof(xfrm4_policy_table), GFP_KERNEL); + if (!table) + goto err_alloc; + + table[0].data = &net->xfrm.xfrm4_dst_ops.gc_thresh; + } + + hdr = register_net_sysctl(net, "net/ipv4", table); + if (!hdr) + goto err_reg; + + net->ipv4.xfrm4_hdr = hdr; + return 0; + +err_reg: + if (!net_eq(net, &init_net)) + kfree(table); +err_alloc: + return -ENOMEM; +} + +static void __net_exit xfrm4_net_exit(struct net *net) +{ + struct ctl_table *table; + + if (!net->ipv4.xfrm4_hdr) + return; + + table = net->ipv4.xfrm4_hdr->ctl_table_arg; + unregister_net_sysctl_table(net->ipv4.xfrm4_hdr); + if (!net_eq(net, &init_net)) + kfree(table); +} + +static struct pernet_operations __net_initdata xfrm4_net_ops = { + .init = xfrm4_net_init, + .exit = xfrm4_net_exit, +}; +#endif + +static void __init xfrm4_policy_init(void) +{ + xfrm_policy_register_afinfo(&xfrm4_policy_afinfo); +} + +void __init xfrm4_init(void) +{ + dst_entries_init(&xfrm4_dst_ops); + + xfrm4_state_init(); + xfrm4_policy_init(); + xfrm4_protocol_init(); +#ifdef CONFIG_SYSCTL + register_pernet_subsys(&xfrm4_net_ops); +#endif +} + -- cgit v1.2.3-54-g00ecf