| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * xfrm6_policy.c: based on xfrm4_policy.c |
| * |
| * Authors: |
| * Mitsuru KANDA @USAGI |
| * Kazunori MIYAZAWA @USAGI |
| * Kunihiro Ishiguro <kunihiro@ipinfusion.com> |
| * IPv6 support |
| * YOSHIFUJI Hideaki |
| * Split up af-specific portion |
| * |
| */ |
| |
| #include <linux/err.h> |
| #include <linux/kernel.h> |
| #include <linux/netdevice.h> |
| #include <net/addrconf.h> |
| #include <net/dst.h> |
| #include <net/xfrm.h> |
| #include <net/ip.h> |
| #include <net/ipv6.h> |
| #include <net/ip6_route.h> |
| #include <net/l3mdev.h> |
| #if IS_ENABLED(CONFIG_IPV6_MIP6) |
| #include <net/mip6.h> |
| #endif |
| |
| static struct dst_entry *xfrm6_dst_lookup(struct net *net, int tos, int oif, |
| const xfrm_address_t *saddr, |
| const xfrm_address_t *daddr, |
| u32 mark) |
| { |
| struct flowi6 fl6; |
| struct dst_entry *dst; |
| int err; |
| |
| memset(&fl6, 0, sizeof(fl6)); |
| fl6.flowi6_oif = l3mdev_master_ifindex_by_index(net, oif); |
| fl6.flowi6_flags = FLOWI_FLAG_SKIP_NH_OIF; |
| fl6.flowi6_mark = mark; |
| memcpy(&fl6.daddr, daddr, sizeof(fl6.daddr)); |
| if (saddr) |
| memcpy(&fl6.saddr, saddr, sizeof(fl6.saddr)); |
| |
| dst = ip6_route_output(net, NULL, &fl6); |
| |
| err = dst->error; |
| if (dst->error) { |
| dst_release(dst); |
| dst = ERR_PTR(err); |
| } |
| |
| return dst; |
| } |
| |
| static int xfrm6_get_saddr(struct net *net, int oif, |
| xfrm_address_t *saddr, xfrm_address_t *daddr, |
| u32 mark) |
| { |
| struct dst_entry *dst; |
| struct net_device *dev; |
| |
| dst = xfrm6_dst_lookup(net, 0, oif, NULL, daddr, mark); |
| if (IS_ERR(dst)) |
| return -EHOSTUNREACH; |
| |
| dev = ip6_dst_idev(dst)->dev; |
| ipv6_dev_get_saddr(dev_net(dev), dev, &daddr->in6, 0, &saddr->in6); |
| dst_release(dst); |
| return 0; |
| } |
| |
| static int xfrm6_get_tos(const struct flowi *fl) |
| { |
| return 0; |
| } |
| |
| static int xfrm6_init_path(struct xfrm_dst *path, struct dst_entry *dst, |
| int nfheader_len) |
| { |
| if (dst->ops->family == AF_INET6) { |
| struct rt6_info *rt = (struct rt6_info *)dst; |
| path->path_cookie = rt6_get_cookie(rt); |
| } |
| |
| path->u.rt6.rt6i_nfheader_len = nfheader_len; |
| |
| return 0; |
| } |
| |
| static int xfrm6_fill_dst(struct xfrm_dst *xdst, struct net_device *dev, |
| const struct flowi *fl) |
| { |
| struct rt6_info *rt = (struct rt6_info *)xdst->route; |
| |
| xdst->u.dst.dev = dev; |
| dev_hold(dev); |
| |
| xdst->u.rt6.rt6i_idev = in6_dev_get(dev); |
| if (!xdst->u.rt6.rt6i_idev) { |
| dev_put(dev); |
| return -ENODEV; |
| } |
| |
| /* Sheit... I remember I did this right. Apparently, |
| * it was magically lost, so this code needs audit */ |
| xdst->u.rt6.rt6i_flags = rt->rt6i_flags & (RTF_ANYCAST | |
| RTF_LOCAL); |
| xdst->u.rt6.rt6i_metric = rt->rt6i_metric; |
| xdst->u.rt6.rt6i_node = rt->rt6i_node; |
| xdst->route_cookie = rt6_get_cookie(rt); |
| xdst->u.rt6.rt6i_gateway = rt->rt6i_gateway; |
| xdst->u.rt6.rt6i_dst = rt->rt6i_dst; |
| xdst->u.rt6.rt6i_src = rt->rt6i_src; |
| INIT_LIST_HEAD(&xdst->u.rt6.rt6i_uncached); |
| rt6_uncached_list_add(&xdst->u.rt6); |
| atomic_inc(&dev_net(dev)->ipv6.rt6_stats->fib_rt_uncache); |
| |
| return 0; |
| } |
| |
| static inline void |
| _decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse) |
| { |
| struct flowi6 *fl6 = &fl->u.ip6; |
| int onlyproto = 0; |
| const struct ipv6hdr *hdr = ipv6_hdr(skb); |
| u16 offset = sizeof(*hdr); |
| struct ipv6_opt_hdr *exthdr; |
| const unsigned char *nh = skb_network_header(skb); |
| u16 nhoff = IP6CB(skb)->nhoff; |
| int oif = 0; |
| u8 nexthdr; |
| |
| if (!nhoff) |
| nhoff = offsetof(struct ipv6hdr, nexthdr); |
| |
| nexthdr = nh[nhoff]; |
| |
| if (skb_dst(skb)) |
| oif = skb_dst(skb)->dev->ifindex; |
| |
| memset(fl6, 0, sizeof(struct flowi6)); |
| fl6->flowi6_mark = skb->mark; |
| fl6->flowi6_oif = reverse ? skb->skb_iif : oif; |
| |
| fl6->daddr = reverse ? hdr->saddr : hdr->daddr; |
| fl6->saddr = reverse ? hdr->daddr : hdr->saddr; |
| |
| while (nh + offset + 1 < skb->data || |
| pskb_may_pull(skb, nh + offset + 1 - skb->data)) { |
| nh = skb_network_header(skb); |
| exthdr = (struct ipv6_opt_hdr *)(nh + offset); |
| |
| switch (nexthdr) { |
| case NEXTHDR_FRAGMENT: |
| onlyproto = 1; |
| /* fall through */ |
| case NEXTHDR_ROUTING: |
| case NEXTHDR_HOP: |
| case NEXTHDR_DEST: |
| offset += ipv6_optlen(exthdr); |
| nexthdr = exthdr->nexthdr; |
| exthdr = (struct ipv6_opt_hdr *)(nh + offset); |
| break; |
| |
| case IPPROTO_UDP: |
| case IPPROTO_UDPLITE: |
| case IPPROTO_TCP: |
| case IPPROTO_SCTP: |
| case IPPROTO_DCCP: |
| if (!onlyproto && (nh + offset + 4 < skb->data || |
| pskb_may_pull(skb, nh + offset + 4 - skb->data))) { |
| __be16 *ports; |
| |
| nh = skb_network_header(skb); |
| ports = (__be16 *)(nh + offset); |
| fl6->fl6_sport = ports[!!reverse]; |
| fl6->fl6_dport = ports[!reverse]; |
| } |
| fl6->flowi6_proto = nexthdr; |
| return; |
| |
| case IPPROTO_ICMPV6: |
| if (!onlyproto && (nh + offset + 2 < skb->data || |
| pskb_may_pull(skb, nh + offset + 2 - skb->data))) { |
| u8 *icmp; |
| |
| nh = skb_network_header(skb); |
| icmp = (u8 *)(nh + offset); |
| fl6->fl6_icmp_type = icmp[0]; |
| fl6->fl6_icmp_code = icmp[1]; |
| } |
| fl6->flowi6_proto = nexthdr; |
| return; |
| |
| #if IS_ENABLED(CONFIG_IPV6_MIP6) |
| case IPPROTO_MH: |
| offset += ipv6_optlen(exthdr); |
| if (!onlyproto && (nh + offset + 3 < skb->data || |
| pskb_may_pull(skb, nh + offset + 3 - skb->data))) { |
| struct ip6_mh *mh; |
| |
| nh = skb_network_header(skb); |
| mh = (struct ip6_mh *)(nh + offset); |
| fl6->fl6_mh_type = mh->ip6mh_type; |
| } |
| fl6->flowi6_proto = nexthdr; |
| return; |
| #endif |
| |
| /* XXX Why are there these headers? */ |
| case IPPROTO_AH: |
| case IPPROTO_ESP: |
| case IPPROTO_COMP: |
| default: |
| fl6->fl6_ipsec_spi = 0; |
| fl6->flowi6_proto = nexthdr; |
| return; |
| } |
| } |
| } |
| |
| static void xfrm6_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 xfrm6_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 xfrm6_dst_destroy(struct dst_entry *dst) |
| { |
| struct xfrm_dst *xdst = (struct xfrm_dst *)dst; |
| |
| if (likely(xdst->u.rt6.rt6i_idev)) |
| in6_dev_put(xdst->u.rt6.rt6i_idev); |
| dst_destroy_metrics_generic(dst); |
| if (xdst->u.rt6.rt6i_uncached_list) |
| rt6_uncached_list_del(&xdst->u.rt6); |
| xfrm_dst_destroy(xdst); |
| } |
| |
| static void xfrm6_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.rt6.rt6i_idev->dev == dev) { |
| struct inet6_dev *loopback_idev = |
| in6_dev_get(dev_net(dev)->loopback_dev); |
| BUG_ON(!loopback_idev); |
| |
| do { |
| in6_dev_put(xdst->u.rt6.rt6i_idev); |
| xdst->u.rt6.rt6i_idev = loopback_idev; |
| in6_dev_hold(loopback_idev); |
| xdst = (struct xfrm_dst *)xfrm_dst_child(&xdst->u.dst); |
| } while (xdst->u.dst.xfrm); |
| |
| __in6_dev_put(loopback_idev); |
| } |
| |
| xfrm_dst_ifdown(dst, dev); |
| } |
| |
| static struct dst_ops xfrm6_dst_ops_template = { |
| .family = AF_INET6, |
| .update_pmtu = xfrm6_update_pmtu, |
| .redirect = xfrm6_redirect, |
| .cow_metrics = dst_cow_metrics_generic, |
| .destroy = xfrm6_dst_destroy, |
| .ifdown = xfrm6_dst_ifdown, |
| .local_out = __ip6_local_out, |
| .gc_thresh = 32768, |
| }; |
| |
| static const struct xfrm_policy_afinfo xfrm6_policy_afinfo = { |
| .dst_ops = &xfrm6_dst_ops_template, |
| .dst_lookup = xfrm6_dst_lookup, |
| .get_saddr = xfrm6_get_saddr, |
| .decode_session = _decode_session6, |
| .get_tos = xfrm6_get_tos, |
| .init_path = xfrm6_init_path, |
| .fill_dst = xfrm6_fill_dst, |
| .blackhole_route = ip6_blackhole_route, |
| }; |
| |
| static int __init xfrm6_policy_init(void) |
| { |
| return xfrm_policy_register_afinfo(&xfrm6_policy_afinfo, AF_INET6); |
| } |
| |
| static void xfrm6_policy_fini(void) |
| { |
| xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo); |
| } |
| |
| #ifdef CONFIG_SYSCTL |
| static struct ctl_table xfrm6_policy_table[] = { |
| { |
| .procname = "xfrm6_gc_thresh", |
| .data = &init_net.xfrm.xfrm6_dst_ops.gc_thresh, |
| .maxlen = sizeof(int), |
| .mode = 0644, |
| .proc_handler = proc_dointvec, |
| }, |
| { } |
| }; |
| |
| static int __net_init xfrm6_net_sysctl_init(struct net *net) |
| { |
| struct ctl_table *table; |
| struct ctl_table_header *hdr; |
| |
| table = xfrm6_policy_table; |
| if (!net_eq(net, &init_net)) { |
| table = kmemdup(table, sizeof(xfrm6_policy_table), GFP_KERNEL); |
| if (!table) |
| goto err_alloc; |
| |
| table[0].data = &net->xfrm.xfrm6_dst_ops.gc_thresh; |
| } |
| |
| hdr = register_net_sysctl(net, "net/ipv6", table); |
| if (!hdr) |
| goto err_reg; |
| |
| net->ipv6.sysctl.xfrm6_hdr = hdr; |
| return 0; |
| |
| err_reg: |
| if (!net_eq(net, &init_net)) |
| kfree(table); |
| err_alloc: |
| return -ENOMEM; |
| } |
| |
| static void __net_exit xfrm6_net_sysctl_exit(struct net *net) |
| { |
| struct ctl_table *table; |
| |
| if (!net->ipv6.sysctl.xfrm6_hdr) |
| return; |
| |
| table = net->ipv6.sysctl.xfrm6_hdr->ctl_table_arg; |
| unregister_net_sysctl_table(net->ipv6.sysctl.xfrm6_hdr); |
| if (!net_eq(net, &init_net)) |
| kfree(table); |
| } |
| #else /* CONFIG_SYSCTL */ |
| static inline int xfrm6_net_sysctl_init(struct net *net) |
| { |
| return 0; |
| } |
| |
| static inline void xfrm6_net_sysctl_exit(struct net *net) |
| { |
| } |
| #endif |
| |
| static int __net_init xfrm6_net_init(struct net *net) |
| { |
| int ret; |
| |
| memcpy(&net->xfrm.xfrm6_dst_ops, &xfrm6_dst_ops_template, |
| sizeof(xfrm6_dst_ops_template)); |
| ret = dst_entries_init(&net->xfrm.xfrm6_dst_ops); |
| if (ret) |
| return ret; |
| |
| ret = xfrm6_net_sysctl_init(net); |
| if (ret) |
| dst_entries_destroy(&net->xfrm.xfrm6_dst_ops); |
| |
| return ret; |
| } |
| |
| static void __net_exit xfrm6_net_exit(struct net *net) |
| { |
| xfrm6_net_sysctl_exit(net); |
| dst_entries_destroy(&net->xfrm.xfrm6_dst_ops); |
| } |
| |
| static struct pernet_operations xfrm6_net_ops = { |
| .init = xfrm6_net_init, |
| .exit = xfrm6_net_exit, |
| }; |
| |
| int __init xfrm6_init(void) |
| { |
| int ret; |
| |
| ret = xfrm6_policy_init(); |
| if (ret) |
| goto out; |
| ret = xfrm6_state_init(); |
| if (ret) |
| goto out_policy; |
| |
| ret = xfrm6_protocol_init(); |
| if (ret) |
| goto out_state; |
| |
| register_pernet_subsys(&xfrm6_net_ops); |
| out: |
| return ret; |
| out_state: |
| xfrm6_state_fini(); |
| out_policy: |
| xfrm6_policy_fini(); |
| goto out; |
| } |
| |
| void xfrm6_fini(void) |
| { |
| unregister_pernet_subsys(&xfrm6_net_ops); |
| xfrm6_protocol_fini(); |
| xfrm6_policy_fini(); |
| xfrm6_state_fini(); |
| } |