| /* |
| * 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 <linux/if_tunnel.h> |
| #include <net/dst.h> |
| #include <net/xfrm.h> |
| #include <net/ip.h> |
| #include <net/l3mdev.h> |
| |
| static struct xfrm_policy_afinfo xfrm4_policy_afinfo; |
| |
| static struct dst_entry *__xfrm4_dst_lookup(struct net *net, struct flowi4 *fl4, |
| int tos, int oif, |
| const xfrm_address_t *saddr, |
| const xfrm_address_t *daddr, |
| u32 mark) |
| { |
| struct rtable *rt; |
| |
| memset(fl4, 0, sizeof(*fl4)); |
| fl4->daddr = daddr->a4; |
| fl4->flowi4_tos = tos; |
| fl4->flowi4_oif = l3mdev_master_ifindex_by_index(net, oif); |
| fl4->flowi4_mark = mark; |
| if (saddr) |
| fl4->saddr = saddr->a4; |
| |
| fl4->flowi4_flags = FLOWI_FLAG_SKIP_NH_OIF; |
| |
| 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, int oif, |
| const xfrm_address_t *saddr, |
| const xfrm_address_t *daddr, |
| u32 mark) |
| { |
| struct flowi4 fl4; |
| |
| return __xfrm4_dst_lookup(net, &fl4, tos, oif, saddr, daddr, mark); |
| } |
| |
| static int xfrm4_get_saddr(struct net *net, int oif, |
| xfrm_address_t *saddr, xfrm_address_t *daddr, |
| u32 mark) |
| { |
| struct dst_entry *dst; |
| struct flowi4 fl4; |
| |
| dst = __xfrm4_dst_lookup(net, &fl4, 0, oif, NULL, daddr, mark); |
| 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; |
| xdst->u.rt.rt_mtu_locked = rt->rt_mtu_locked; |
| xdst->u.rt.rt_table_id = rt->rt_table_id; |
| 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); |
| int ihl = iph->ihl; |
| u8 *xprth = skb_network_header(skb) + 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; |
| |
| fl4->flowi4_proto = iph->protocol; |
| fl4->daddr = reverse ? iph->saddr : iph->daddr; |
| fl4->saddr = reverse ? iph->daddr : iph->saddr; |
| fl4->flowi4_tos = iph->tos; |
| |
| 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; |
| |
| xprth = skb_network_header(skb) + ihl * 4; |
| ports = (__be16 *)xprth; |
| |
| fl4->fl4_sport = ports[!!reverse]; |
| fl4->fl4_dport = ports[!reverse]; |
| } |
| break; |
| |
| case IPPROTO_ICMP: |
| if (xprth + 2 < skb->data || |
| pskb_may_pull(skb, xprth + 2 - skb->data)) { |
| u8 *icmp; |
| |
| xprth = skb_network_header(skb) + ihl * 4; |
| icmp = xprth; |
| |
| fl4->fl4_icmp_type = icmp[0]; |
| fl4->fl4_icmp_code = icmp[1]; |
| } |
| break; |
| |
| case IPPROTO_ESP: |
| if (xprth + 4 < skb->data || |
| pskb_may_pull(skb, xprth + 4 - skb->data)) { |
| __be32 *ehdr; |
| |
| xprth = skb_network_header(skb) + ihl * 4; |
| ehdr = (__be32 *)xprth; |
| |
| fl4->fl4_ipsec_spi = ehdr[0]; |
| } |
| break; |
| |
| case IPPROTO_AH: |
| if (xprth + 8 < skb->data || |
| pskb_may_pull(skb, xprth + 8 - skb->data)) { |
| __be32 *ah_hdr; |
| |
| xprth = skb_network_header(skb) + ihl * 4; |
| ah_hdr = (__be32 *)xprth; |
| |
| fl4->fl4_ipsec_spi = ah_hdr[1]; |
| } |
| break; |
| |
| case IPPROTO_COMP: |
| if (xprth + 4 < skb->data || |
| pskb_may_pull(skb, xprth + 4 - skb->data)) { |
| __be16 *ipcomp_hdr; |
| |
| xprth = skb_network_header(skb) + ihl * 4; |
| ipcomp_hdr = (__be16 *)xprth; |
| |
| fl4->fl4_ipsec_spi = htonl(ntohs(ipcomp_hdr[1])); |
| } |
| break; |
| |
| case IPPROTO_GRE: |
| if (xprth + 12 < skb->data || |
| pskb_may_pull(skb, xprth + 12 - skb->data)) { |
| __be16 *greflags; |
| __be32 *gre_hdr; |
| |
| xprth = skb_network_header(skb) + ihl * 4; |
| greflags = (__be16 *)xprth; |
| 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; |
| } |
| } |
| } |
| |
| 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_template = { |
| .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 = INT_MAX, |
| }; |
| |
| static struct xfrm_policy_afinfo xfrm4_policy_afinfo = { |
| .family = AF_INET, |
| .dst_ops = &xfrm4_dst_ops_template, |
| .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 __net_init int xfrm4_net_sysctl_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 __net_exit void xfrm4_net_sysctl_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); |
| } |
| #else /* CONFIG_SYSCTL */ |
| static inline int xfrm4_net_sysctl_init(struct net *net) |
| { |
| return 0; |
| } |
| |
| static inline void xfrm4_net_sysctl_exit(struct net *net) |
| { |
| } |
| #endif |
| |
| static int __net_init xfrm4_net_init(struct net *net) |
| { |
| int ret; |
| |
| memcpy(&net->xfrm.xfrm4_dst_ops, &xfrm4_dst_ops_template, |
| sizeof(xfrm4_dst_ops_template)); |
| ret = dst_entries_init(&net->xfrm.xfrm4_dst_ops); |
| if (ret) |
| return ret; |
| |
| ret = xfrm4_net_sysctl_init(net); |
| if (ret) |
| dst_entries_destroy(&net->xfrm.xfrm4_dst_ops); |
| |
| return ret; |
| } |
| |
| static void __net_exit xfrm4_net_exit(struct net *net) |
| { |
| xfrm4_net_sysctl_exit(net); |
| dst_entries_destroy(&net->xfrm.xfrm4_dst_ops); |
| } |
| |
| static struct pernet_operations __net_initdata xfrm4_net_ops = { |
| .init = xfrm4_net_init, |
| .exit = xfrm4_net_exit, |
| }; |
| |
| static void __init xfrm4_policy_init(void) |
| { |
| xfrm_policy_register_afinfo(&xfrm4_policy_afinfo); |
| } |
| |
| void __init xfrm4_init(void) |
| { |
| xfrm4_state_init(); |
| xfrm4_policy_init(); |
| xfrm4_protocol_init(); |
| register_pernet_subsys(&xfrm4_net_ops); |
| } |
| |