| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * Linux INET6 implementation |
| * FIB front-end. |
| * |
| * Authors: |
| * Pedro Roque <roque@di.fc.ul.pt> |
| */ |
| |
| /* Changes: |
| * |
| * YOSHIFUJI Hideaki @USAGI |
| * reworked default router selection. |
| * - respect outgoing interface |
| * - select from (probably) reachable routers (i.e. |
| * routers in REACHABLE, STALE, DELAY or PROBE states). |
| * - always select the same router if it is (probably) |
| * reachable. otherwise, round-robin the list. |
| * Ville Nuorvala |
| * Fixed routing subtrees. |
| */ |
| |
| #define pr_fmt(fmt) "IPv6: " fmt |
| |
| #include <linux/capability.h> |
| #include <linux/errno.h> |
| #include <linux/export.h> |
| #include <linux/types.h> |
| #include <linux/times.h> |
| #include <linux/socket.h> |
| #include <linux/sockios.h> |
| #include <linux/net.h> |
| #include <linux/route.h> |
| #include <linux/netdevice.h> |
| #include <linux/in6.h> |
| #include <linux/mroute6.h> |
| #include <linux/init.h> |
| #include <linux/if_arp.h> |
| #include <linux/proc_fs.h> |
| #include <linux/seq_file.h> |
| #include <linux/nsproxy.h> |
| #include <linux/slab.h> |
| #include <linux/jhash.h> |
| #include <linux/siphash.h> |
| #include <net/net_namespace.h> |
| #include <net/snmp.h> |
| #include <net/ipv6.h> |
| #include <net/ip6_fib.h> |
| #include <net/ip6_route.h> |
| #include <net/ndisc.h> |
| #include <net/addrconf.h> |
| #include <net/tcp.h> |
| #include <linux/rtnetlink.h> |
| #include <net/dst.h> |
| #include <net/dst_metadata.h> |
| #include <net/xfrm.h> |
| #include <net/netevent.h> |
| #include <net/netlink.h> |
| #include <net/rtnh.h> |
| #include <net/lwtunnel.h> |
| #include <net/ip_tunnels.h> |
| #include <net/l3mdev.h> |
| #include <net/ip.h> |
| #include <linux/uaccess.h> |
| #include <linux/btf_ids.h> |
| |
| #ifdef CONFIG_SYSCTL |
| #include <linux/sysctl.h> |
| #endif |
| |
| static int ip6_rt_type_to_error(u8 fib6_type); |
| |
| #define CREATE_TRACE_POINTS |
| #include <trace/events/fib6.h> |
| EXPORT_TRACEPOINT_SYMBOL_GPL(fib6_table_lookup); |
| #undef CREATE_TRACE_POINTS |
| |
| enum rt6_nud_state { |
| RT6_NUD_FAIL_HARD = -3, |
| RT6_NUD_FAIL_PROBE = -2, |
| RT6_NUD_FAIL_DO_RR = -1, |
| RT6_NUD_SUCCEED = 1 |
| }; |
| |
| INDIRECT_CALLABLE_SCOPE |
| struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie); |
| static unsigned int ip6_default_advmss(const struct dst_entry *dst); |
| INDIRECT_CALLABLE_SCOPE |
| unsigned int ip6_mtu(const struct dst_entry *dst); |
| static struct dst_entry *ip6_negative_advice(struct dst_entry *); |
| static void ip6_dst_destroy(struct dst_entry *); |
| static void ip6_dst_ifdown(struct dst_entry *, |
| struct net_device *dev, int how); |
| static int ip6_dst_gc(struct dst_ops *ops); |
| |
| static int ip6_pkt_discard(struct sk_buff *skb); |
| static int ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb); |
| static int ip6_pkt_prohibit(struct sk_buff *skb); |
| static int ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb); |
| static void ip6_link_failure(struct sk_buff *skb); |
| static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, |
| struct sk_buff *skb, u32 mtu, |
| bool confirm_neigh); |
| static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, |
| struct sk_buff *skb); |
| static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif, |
| int strict); |
| static size_t rt6_nlmsg_size(struct fib6_info *f6i); |
| static int rt6_fill_node(struct net *net, struct sk_buff *skb, |
| struct fib6_info *rt, struct dst_entry *dst, |
| struct in6_addr *dest, struct in6_addr *src, |
| int iif, int type, u32 portid, u32 seq, |
| unsigned int flags); |
| static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res, |
| const struct in6_addr *daddr, |
| const struct in6_addr *saddr); |
| |
| #ifdef CONFIG_IPV6_ROUTE_INFO |
| static struct fib6_info *rt6_add_route_info(struct net *net, |
| const struct in6_addr *prefix, int prefixlen, |
| const struct in6_addr *gwaddr, |
| struct net_device *dev, |
| unsigned int pref); |
| static struct fib6_info *rt6_get_route_info(struct net *net, |
| const struct in6_addr *prefix, int prefixlen, |
| const struct in6_addr *gwaddr, |
| struct net_device *dev); |
| #endif |
| |
| struct uncached_list { |
| spinlock_t lock; |
| struct list_head head; |
| }; |
| |
| static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt6_uncached_list); |
| |
| void rt6_uncached_list_add(struct rt6_info *rt) |
| { |
| struct uncached_list *ul = raw_cpu_ptr(&rt6_uncached_list); |
| |
| rt->rt6i_uncached_list = ul; |
| |
| spin_lock_bh(&ul->lock); |
| list_add_tail(&rt->rt6i_uncached, &ul->head); |
| spin_unlock_bh(&ul->lock); |
| } |
| |
| void rt6_uncached_list_del(struct rt6_info *rt) |
| { |
| if (!list_empty(&rt->rt6i_uncached)) { |
| struct uncached_list *ul = rt->rt6i_uncached_list; |
| struct net *net = dev_net(rt->dst.dev); |
| |
| spin_lock_bh(&ul->lock); |
| list_del(&rt->rt6i_uncached); |
| atomic_dec(&net->ipv6.rt6_stats->fib_rt_uncache); |
| spin_unlock_bh(&ul->lock); |
| } |
| } |
| |
| static void rt6_uncached_list_flush_dev(struct net *net, struct net_device *dev) |
| { |
| struct net_device *loopback_dev = net->loopback_dev; |
| int cpu; |
| |
| if (dev == loopback_dev) |
| return; |
| |
| for_each_possible_cpu(cpu) { |
| struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu); |
| struct rt6_info *rt; |
| |
| spin_lock_bh(&ul->lock); |
| list_for_each_entry(rt, &ul->head, rt6i_uncached) { |
| struct inet6_dev *rt_idev = rt->rt6i_idev; |
| struct net_device *rt_dev = rt->dst.dev; |
| |
| if (rt_idev->dev == dev) { |
| rt->rt6i_idev = in6_dev_get(loopback_dev); |
| in6_dev_put(rt_idev); |
| } |
| |
| if (rt_dev == dev) { |
| rt->dst.dev = blackhole_netdev; |
| dev_hold(rt->dst.dev); |
| dev_put(rt_dev); |
| } |
| } |
| spin_unlock_bh(&ul->lock); |
| } |
| } |
| |
| static inline const void *choose_neigh_daddr(const struct in6_addr *p, |
| struct sk_buff *skb, |
| const void *daddr) |
| { |
| if (!ipv6_addr_any(p)) |
| return (const void *) p; |
| else if (skb) |
| return &ipv6_hdr(skb)->daddr; |
| return daddr; |
| } |
| |
| struct neighbour *ip6_neigh_lookup(const struct in6_addr *gw, |
| struct net_device *dev, |
| struct sk_buff *skb, |
| const void *daddr) |
| { |
| struct neighbour *n; |
| |
| daddr = choose_neigh_daddr(gw, skb, daddr); |
| n = __ipv6_neigh_lookup(dev, daddr); |
| if (n) |
| return n; |
| |
| n = neigh_create(&nd_tbl, daddr, dev); |
| return IS_ERR(n) ? NULL : n; |
| } |
| |
| static struct neighbour *ip6_dst_neigh_lookup(const struct dst_entry *dst, |
| struct sk_buff *skb, |
| const void *daddr) |
| { |
| const struct rt6_info *rt = container_of(dst, struct rt6_info, dst); |
| |
| return ip6_neigh_lookup(rt6_nexthop(rt, &in6addr_any), |
| dst->dev, skb, daddr); |
| } |
| |
| static void ip6_confirm_neigh(const struct dst_entry *dst, const void *daddr) |
| { |
| struct net_device *dev = dst->dev; |
| struct rt6_info *rt = (struct rt6_info *)dst; |
| |
| daddr = choose_neigh_daddr(rt6_nexthop(rt, &in6addr_any), NULL, daddr); |
| if (!daddr) |
| return; |
| if (dev->flags & (IFF_NOARP | IFF_LOOPBACK)) |
| return; |
| if (ipv6_addr_is_multicast((const struct in6_addr *)daddr)) |
| return; |
| __ipv6_confirm_neigh(dev, daddr); |
| } |
| |
| static struct dst_ops ip6_dst_ops_template = { |
| .family = AF_INET6, |
| .gc = ip6_dst_gc, |
| .gc_thresh = 1024, |
| .check = ip6_dst_check, |
| .default_advmss = ip6_default_advmss, |
| .mtu = ip6_mtu, |
| .cow_metrics = dst_cow_metrics_generic, |
| .destroy = ip6_dst_destroy, |
| .ifdown = ip6_dst_ifdown, |
| .negative_advice = ip6_negative_advice, |
| .link_failure = ip6_link_failure, |
| .update_pmtu = ip6_rt_update_pmtu, |
| .redirect = rt6_do_redirect, |
| .local_out = __ip6_local_out, |
| .neigh_lookup = ip6_dst_neigh_lookup, |
| .confirm_neigh = ip6_confirm_neigh, |
| }; |
| |
| static struct dst_ops ip6_dst_blackhole_ops = { |
| .family = AF_INET6, |
| .default_advmss = ip6_default_advmss, |
| .neigh_lookup = ip6_dst_neigh_lookup, |
| .check = ip6_dst_check, |
| .destroy = ip6_dst_destroy, |
| .cow_metrics = dst_cow_metrics_generic, |
| .update_pmtu = dst_blackhole_update_pmtu, |
| .redirect = dst_blackhole_redirect, |
| .mtu = dst_blackhole_mtu, |
| }; |
| |
| static const u32 ip6_template_metrics[RTAX_MAX] = { |
| [RTAX_HOPLIMIT - 1] = 0, |
| }; |
| |
| static const struct fib6_info fib6_null_entry_template = { |
| .fib6_flags = (RTF_REJECT | RTF_NONEXTHOP), |
| .fib6_protocol = RTPROT_KERNEL, |
| .fib6_metric = ~(u32)0, |
| .fib6_ref = REFCOUNT_INIT(1), |
| .fib6_type = RTN_UNREACHABLE, |
| .fib6_metrics = (struct dst_metrics *)&dst_default_metrics, |
| }; |
| |
| static const struct rt6_info ip6_null_entry_template = { |
| .dst = { |
| .__refcnt = ATOMIC_INIT(1), |
| .__use = 1, |
| .obsolete = DST_OBSOLETE_FORCE_CHK, |
| .error = -ENETUNREACH, |
| .input = ip6_pkt_discard, |
| .output = ip6_pkt_discard_out, |
| }, |
| .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP), |
| }; |
| |
| #ifdef CONFIG_IPV6_MULTIPLE_TABLES |
| |
| static const struct rt6_info ip6_prohibit_entry_template = { |
| .dst = { |
| .__refcnt = ATOMIC_INIT(1), |
| .__use = 1, |
| .obsolete = DST_OBSOLETE_FORCE_CHK, |
| .error = -EACCES, |
| .input = ip6_pkt_prohibit, |
| .output = ip6_pkt_prohibit_out, |
| }, |
| .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP), |
| }; |
| |
| static const struct rt6_info ip6_blk_hole_entry_template = { |
| .dst = { |
| .__refcnt = ATOMIC_INIT(1), |
| .__use = 1, |
| .obsolete = DST_OBSOLETE_FORCE_CHK, |
| .error = -EINVAL, |
| .input = dst_discard, |
| .output = dst_discard_out, |
| }, |
| .rt6i_flags = (RTF_REJECT | RTF_NONEXTHOP), |
| }; |
| |
| #endif |
| |
| static void rt6_info_init(struct rt6_info *rt) |
| { |
| struct dst_entry *dst = &rt->dst; |
| |
| memset(dst + 1, 0, sizeof(*rt) - sizeof(*dst)); |
| INIT_LIST_HEAD(&rt->rt6i_uncached); |
| } |
| |
| /* allocate dst with ip6_dst_ops */ |
| struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev, |
| int flags) |
| { |
| struct rt6_info *rt = dst_alloc(&net->ipv6.ip6_dst_ops, dev, |
| 1, DST_OBSOLETE_FORCE_CHK, flags); |
| |
| if (rt) { |
| rt6_info_init(rt); |
| atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc); |
| } |
| |
| return rt; |
| } |
| EXPORT_SYMBOL(ip6_dst_alloc); |
| |
| static void ip6_dst_destroy(struct dst_entry *dst) |
| { |
| struct rt6_info *rt = (struct rt6_info *)dst; |
| struct fib6_info *from; |
| struct inet6_dev *idev; |
| |
| ip_dst_metrics_put(dst); |
| rt6_uncached_list_del(rt); |
| |
| idev = rt->rt6i_idev; |
| if (idev) { |
| rt->rt6i_idev = NULL; |
| in6_dev_put(idev); |
| } |
| |
| from = xchg((__force struct fib6_info **)&rt->from, NULL); |
| fib6_info_release(from); |
| } |
| |
| static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev, |
| int how) |
| { |
| struct rt6_info *rt = (struct rt6_info *)dst; |
| struct inet6_dev *idev = rt->rt6i_idev; |
| struct net_device *loopback_dev = |
| dev_net(dev)->loopback_dev; |
| |
| if (idev && idev->dev != loopback_dev) { |
| struct inet6_dev *loopback_idev = in6_dev_get(loopback_dev); |
| if (loopback_idev) { |
| rt->rt6i_idev = loopback_idev; |
| in6_dev_put(idev); |
| } |
| } |
| } |
| |
| static bool __rt6_check_expired(const struct rt6_info *rt) |
| { |
| if (rt->rt6i_flags & RTF_EXPIRES) |
| return time_after(jiffies, rt->dst.expires); |
| else |
| return false; |
| } |
| |
| static bool rt6_check_expired(const struct rt6_info *rt) |
| { |
| struct fib6_info *from; |
| |
| from = rcu_dereference(rt->from); |
| |
| if (rt->rt6i_flags & RTF_EXPIRES) { |
| if (time_after(jiffies, rt->dst.expires)) |
| return true; |
| } else if (from) { |
| return rt->dst.obsolete != DST_OBSOLETE_FORCE_CHK || |
| fib6_check_expired(from); |
| } |
| return false; |
| } |
| |
| void fib6_select_path(const struct net *net, struct fib6_result *res, |
| struct flowi6 *fl6, int oif, bool have_oif_match, |
| const struct sk_buff *skb, int strict) |
| { |
| struct fib6_info *sibling, *next_sibling; |
| struct fib6_info *match = res->f6i; |
| |
| if (!match->nh && (!match->fib6_nsiblings || have_oif_match)) |
| goto out; |
| |
| if (match->nh && have_oif_match && res->nh) |
| return; |
| |
| /* We might have already computed the hash for ICMPv6 errors. In such |
| * case it will always be non-zero. Otherwise now is the time to do it. |
| */ |
| if (!fl6->mp_hash && |
| (!match->nh || nexthop_is_multipath(match->nh))) |
| fl6->mp_hash = rt6_multipath_hash(net, fl6, skb, NULL); |
| |
| if (unlikely(match->nh)) { |
| nexthop_path_fib6_result(res, fl6->mp_hash); |
| return; |
| } |
| |
| if (fl6->mp_hash <= atomic_read(&match->fib6_nh->fib_nh_upper_bound)) |
| goto out; |
| |
| list_for_each_entry_safe(sibling, next_sibling, &match->fib6_siblings, |
| fib6_siblings) { |
| const struct fib6_nh *nh = sibling->fib6_nh; |
| int nh_upper_bound; |
| |
| nh_upper_bound = atomic_read(&nh->fib_nh_upper_bound); |
| if (fl6->mp_hash > nh_upper_bound) |
| continue; |
| if (rt6_score_route(nh, sibling->fib6_flags, oif, strict) < 0) |
| break; |
| match = sibling; |
| break; |
| } |
| |
| out: |
| res->f6i = match; |
| res->nh = match->fib6_nh; |
| } |
| |
| /* |
| * Route lookup. rcu_read_lock() should be held. |
| */ |
| |
| static bool __rt6_device_match(struct net *net, const struct fib6_nh *nh, |
| const struct in6_addr *saddr, int oif, int flags) |
| { |
| const struct net_device *dev; |
| |
| if (nh->fib_nh_flags & RTNH_F_DEAD) |
| return false; |
| |
| dev = nh->fib_nh_dev; |
| if (oif) { |
| if (dev->ifindex == oif) |
| return true; |
| } else { |
| if (ipv6_chk_addr(net, saddr, dev, |
| flags & RT6_LOOKUP_F_IFACE)) |
| return true; |
| } |
| |
| return false; |
| } |
| |
| struct fib6_nh_dm_arg { |
| struct net *net; |
| const struct in6_addr *saddr; |
| int oif; |
| int flags; |
| struct fib6_nh *nh; |
| }; |
| |
| static int __rt6_nh_dev_match(struct fib6_nh *nh, void *_arg) |
| { |
| struct fib6_nh_dm_arg *arg = _arg; |
| |
| arg->nh = nh; |
| return __rt6_device_match(arg->net, nh, arg->saddr, arg->oif, |
| arg->flags); |
| } |
| |
| /* returns fib6_nh from nexthop or NULL */ |
| static struct fib6_nh *rt6_nh_dev_match(struct net *net, struct nexthop *nh, |
| struct fib6_result *res, |
| const struct in6_addr *saddr, |
| int oif, int flags) |
| { |
| struct fib6_nh_dm_arg arg = { |
| .net = net, |
| .saddr = saddr, |
| .oif = oif, |
| .flags = flags, |
| }; |
| |
| if (nexthop_is_blackhole(nh)) |
| return NULL; |
| |
| if (nexthop_for_each_fib6_nh(nh, __rt6_nh_dev_match, &arg)) |
| return arg.nh; |
| |
| return NULL; |
| } |
| |
| static void rt6_device_match(struct net *net, struct fib6_result *res, |
| const struct in6_addr *saddr, int oif, int flags) |
| { |
| struct fib6_info *f6i = res->f6i; |
| struct fib6_info *spf6i; |
| struct fib6_nh *nh; |
| |
| if (!oif && ipv6_addr_any(saddr)) { |
| if (unlikely(f6i->nh)) { |
| nh = nexthop_fib6_nh(f6i->nh); |
| if (nexthop_is_blackhole(f6i->nh)) |
| goto out_blackhole; |
| } else { |
| nh = f6i->fib6_nh; |
| } |
| if (!(nh->fib_nh_flags & RTNH_F_DEAD)) |
| goto out; |
| } |
| |
| for (spf6i = f6i; spf6i; spf6i = rcu_dereference(spf6i->fib6_next)) { |
| bool matched = false; |
| |
| if (unlikely(spf6i->nh)) { |
| nh = rt6_nh_dev_match(net, spf6i->nh, res, saddr, |
| oif, flags); |
| if (nh) |
| matched = true; |
| } else { |
| nh = spf6i->fib6_nh; |
| if (__rt6_device_match(net, nh, saddr, oif, flags)) |
| matched = true; |
| } |
| if (matched) { |
| res->f6i = spf6i; |
| goto out; |
| } |
| } |
| |
| if (oif && flags & RT6_LOOKUP_F_IFACE) { |
| res->f6i = net->ipv6.fib6_null_entry; |
| nh = res->f6i->fib6_nh; |
| goto out; |
| } |
| |
| if (unlikely(f6i->nh)) { |
| nh = nexthop_fib6_nh(f6i->nh); |
| if (nexthop_is_blackhole(f6i->nh)) |
| goto out_blackhole; |
| } else { |
| nh = f6i->fib6_nh; |
| } |
| |
| if (nh->fib_nh_flags & RTNH_F_DEAD) { |
| res->f6i = net->ipv6.fib6_null_entry; |
| nh = res->f6i->fib6_nh; |
| } |
| out: |
| res->nh = nh; |
| res->fib6_type = res->f6i->fib6_type; |
| res->fib6_flags = res->f6i->fib6_flags; |
| return; |
| |
| out_blackhole: |
| res->fib6_flags |= RTF_REJECT; |
| res->fib6_type = RTN_BLACKHOLE; |
| res->nh = nh; |
| } |
| |
| #ifdef CONFIG_IPV6_ROUTER_PREF |
| struct __rt6_probe_work { |
| struct work_struct work; |
| struct in6_addr target; |
| struct net_device *dev; |
| }; |
| |
| static void rt6_probe_deferred(struct work_struct *w) |
| { |
| struct in6_addr mcaddr; |
| struct __rt6_probe_work *work = |
| container_of(w, struct __rt6_probe_work, work); |
| |
| addrconf_addr_solict_mult(&work->target, &mcaddr); |
| ndisc_send_ns(work->dev, &work->target, &mcaddr, NULL, 0); |
| dev_put(work->dev); |
| kfree(work); |
| } |
| |
| static void rt6_probe(struct fib6_nh *fib6_nh) |
| { |
| struct __rt6_probe_work *work = NULL; |
| const struct in6_addr *nh_gw; |
| unsigned long last_probe; |
| struct neighbour *neigh; |
| struct net_device *dev; |
| struct inet6_dev *idev; |
| |
| /* |
| * Okay, this does not seem to be appropriate |
| * for now, however, we need to check if it |
| * is really so; aka Router Reachability Probing. |
| * |
| * Router Reachability Probe MUST be rate-limited |
| * to no more than one per minute. |
| */ |
| if (!fib6_nh->fib_nh_gw_family) |
| return; |
| |
| nh_gw = &fib6_nh->fib_nh_gw6; |
| dev = fib6_nh->fib_nh_dev; |
| rcu_read_lock_bh(); |
| last_probe = READ_ONCE(fib6_nh->last_probe); |
| idev = __in6_dev_get(dev); |
| neigh = __ipv6_neigh_lookup_noref(dev, nh_gw); |
| if (neigh) { |
| if (neigh->nud_state & NUD_VALID) |
| goto out; |
| |
| write_lock(&neigh->lock); |
| if (!(neigh->nud_state & NUD_VALID) && |
| time_after(jiffies, |
| neigh->updated + idev->cnf.rtr_probe_interval)) { |
| work = kmalloc(sizeof(*work), GFP_ATOMIC); |
| if (work) |
| __neigh_set_probe_once(neigh); |
| } |
| write_unlock(&neigh->lock); |
| } else if (time_after(jiffies, last_probe + |
| idev->cnf.rtr_probe_interval)) { |
| work = kmalloc(sizeof(*work), GFP_ATOMIC); |
| } |
| |
| if (!work || cmpxchg(&fib6_nh->last_probe, |
| last_probe, jiffies) != last_probe) { |
| kfree(work); |
| } else { |
| INIT_WORK(&work->work, rt6_probe_deferred); |
| work->target = *nh_gw; |
| dev_hold(dev); |
| work->dev = dev; |
| schedule_work(&work->work); |
| } |
| |
| out: |
| rcu_read_unlock_bh(); |
| } |
| #else |
| static inline void rt6_probe(struct fib6_nh *fib6_nh) |
| { |
| } |
| #endif |
| |
| /* |
| * Default Router Selection (RFC 2461 6.3.6) |
| */ |
| static enum rt6_nud_state rt6_check_neigh(const struct fib6_nh *fib6_nh) |
| { |
| enum rt6_nud_state ret = RT6_NUD_FAIL_HARD; |
| struct neighbour *neigh; |
| |
| rcu_read_lock_bh(); |
| neigh = __ipv6_neigh_lookup_noref(fib6_nh->fib_nh_dev, |
| &fib6_nh->fib_nh_gw6); |
| if (neigh) { |
| read_lock(&neigh->lock); |
| if (neigh->nud_state & NUD_VALID) |
| ret = RT6_NUD_SUCCEED; |
| #ifdef CONFIG_IPV6_ROUTER_PREF |
| else if (!(neigh->nud_state & NUD_FAILED)) |
| ret = RT6_NUD_SUCCEED; |
| else |
| ret = RT6_NUD_FAIL_PROBE; |
| #endif |
| read_unlock(&neigh->lock); |
| } else { |
| ret = IS_ENABLED(CONFIG_IPV6_ROUTER_PREF) ? |
| RT6_NUD_SUCCEED : RT6_NUD_FAIL_DO_RR; |
| } |
| rcu_read_unlock_bh(); |
| |
| return ret; |
| } |
| |
| static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif, |
| int strict) |
| { |
| int m = 0; |
| |
| if (!oif || nh->fib_nh_dev->ifindex == oif) |
| m = 2; |
| |
| if (!m && (strict & RT6_LOOKUP_F_IFACE)) |
| return RT6_NUD_FAIL_HARD; |
| #ifdef CONFIG_IPV6_ROUTER_PREF |
| m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(fib6_flags)) << 2; |
| #endif |
| if ((strict & RT6_LOOKUP_F_REACHABLE) && |
| !(fib6_flags & RTF_NONEXTHOP) && nh->fib_nh_gw_family) { |
| int n = rt6_check_neigh(nh); |
| if (n < 0) |
| return n; |
| } |
| return m; |
| } |
| |
| static bool find_match(struct fib6_nh *nh, u32 fib6_flags, |
| int oif, int strict, int *mpri, bool *do_rr) |
| { |
| bool match_do_rr = false; |
| bool rc = false; |
| int m; |
| |
| if (nh->fib_nh_flags & RTNH_F_DEAD) |
| goto out; |
| |
| if (ip6_ignore_linkdown(nh->fib_nh_dev) && |
| nh->fib_nh_flags & RTNH_F_LINKDOWN && |
| !(strict & RT6_LOOKUP_F_IGNORE_LINKSTATE)) |
| goto out; |
| |
| m = rt6_score_route(nh, fib6_flags, oif, strict); |
| if (m == RT6_NUD_FAIL_DO_RR) { |
| match_do_rr = true; |
| m = 0; /* lowest valid score */ |
| } else if (m == RT6_NUD_FAIL_HARD) { |
| goto out; |
| } |
| |
| if (strict & RT6_LOOKUP_F_REACHABLE) |
| rt6_probe(nh); |
| |
| /* note that m can be RT6_NUD_FAIL_PROBE at this point */ |
| if (m > *mpri) { |
| *do_rr = match_do_rr; |
| *mpri = m; |
| rc = true; |
| } |
| out: |
| return rc; |
| } |
| |
| struct fib6_nh_frl_arg { |
| u32 flags; |
| int oif; |
| int strict; |
| int *mpri; |
| bool *do_rr; |
| struct fib6_nh *nh; |
| }; |
| |
| static int rt6_nh_find_match(struct fib6_nh *nh, void *_arg) |
| { |
| struct fib6_nh_frl_arg *arg = _arg; |
| |
| arg->nh = nh; |
| return find_match(nh, arg->flags, arg->oif, arg->strict, |
| arg->mpri, arg->do_rr); |
| } |
| |
| static void __find_rr_leaf(struct fib6_info *f6i_start, |
| struct fib6_info *nomatch, u32 metric, |
| struct fib6_result *res, struct fib6_info **cont, |
| int oif, int strict, bool *do_rr, int *mpri) |
| { |
| struct fib6_info *f6i; |
| |
| for (f6i = f6i_start; |
| f6i && f6i != nomatch; |
| f6i = rcu_dereference(f6i->fib6_next)) { |
| bool matched = false; |
| struct fib6_nh *nh; |
| |
| if (cont && f6i->fib6_metric != metric) { |
| *cont = f6i; |
| return; |
| } |
| |
| if (fib6_check_expired(f6i)) |
| continue; |
| |
| if (unlikely(f6i->nh)) { |
| struct fib6_nh_frl_arg arg = { |
| .flags = f6i->fib6_flags, |
| .oif = oif, |
| .strict = strict, |
| .mpri = mpri, |
| .do_rr = do_rr |
| }; |
| |
| if (nexthop_is_blackhole(f6i->nh)) { |
| res->fib6_flags = RTF_REJECT; |
| res->fib6_type = RTN_BLACKHOLE; |
| res->f6i = f6i; |
| res->nh = nexthop_fib6_nh(f6i->nh); |
| return; |
| } |
| if (nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_find_match, |
| &arg)) { |
| matched = true; |
| nh = arg.nh; |
| } |
| } else { |
| nh = f6i->fib6_nh; |
| if (find_match(nh, f6i->fib6_flags, oif, strict, |
| mpri, do_rr)) |
| matched = true; |
| } |
| if (matched) { |
| res->f6i = f6i; |
| res->nh = nh; |
| res->fib6_flags = f6i->fib6_flags; |
| res->fib6_type = f6i->fib6_type; |
| } |
| } |
| } |
| |
| static void find_rr_leaf(struct fib6_node *fn, struct fib6_info *leaf, |
| struct fib6_info *rr_head, int oif, int strict, |
| bool *do_rr, struct fib6_result *res) |
| { |
| u32 metric = rr_head->fib6_metric; |
| struct fib6_info *cont = NULL; |
| int mpri = -1; |
| |
| __find_rr_leaf(rr_head, NULL, metric, res, &cont, |
| oif, strict, do_rr, &mpri); |
| |
| __find_rr_leaf(leaf, rr_head, metric, res, &cont, |
| oif, strict, do_rr, &mpri); |
| |
| if (res->f6i || !cont) |
| return; |
| |
| __find_rr_leaf(cont, NULL, metric, res, NULL, |
| oif, strict, do_rr, &mpri); |
| } |
| |
| static void rt6_select(struct net *net, struct fib6_node *fn, int oif, |
| struct fib6_result *res, int strict) |
| { |
| struct fib6_info *leaf = rcu_dereference(fn->leaf); |
| struct fib6_info *rt0; |
| bool do_rr = false; |
| int key_plen; |
| |
| /* make sure this function or its helpers sets f6i */ |
| res->f6i = NULL; |
| |
| if (!leaf || leaf == net->ipv6.fib6_null_entry) |
| goto out; |
| |
| rt0 = rcu_dereference(fn->rr_ptr); |
| if (!rt0) |
| rt0 = leaf; |
| |
| /* Double check to make sure fn is not an intermediate node |
| * and fn->leaf does not points to its child's leaf |
| * (This might happen if all routes under fn are deleted from |
| * the tree and fib6_repair_tree() is called on the node.) |
| */ |
| key_plen = rt0->fib6_dst.plen; |
| #ifdef CONFIG_IPV6_SUBTREES |
| if (rt0->fib6_src.plen) |
| key_plen = rt0->fib6_src.plen; |
| #endif |
| if (fn->fn_bit != key_plen) |
| goto out; |
| |
| find_rr_leaf(fn, leaf, rt0, oif, strict, &do_rr, res); |
| if (do_rr) { |
| struct fib6_info *next = rcu_dereference(rt0->fib6_next); |
| |
| /* no entries matched; do round-robin */ |
| if (!next || next->fib6_metric != rt0->fib6_metric) |
| next = leaf; |
| |
| if (next != rt0) { |
| spin_lock_bh(&leaf->fib6_table->tb6_lock); |
| /* make sure next is not being deleted from the tree */ |
| if (next->fib6_node) |
| rcu_assign_pointer(fn->rr_ptr, next); |
| spin_unlock_bh(&leaf->fib6_table->tb6_lock); |
| } |
| } |
| |
| out: |
| if (!res->f6i) { |
| res->f6i = net->ipv6.fib6_null_entry; |
| res->nh = res->f6i->fib6_nh; |
| res->fib6_flags = res->f6i->fib6_flags; |
| res->fib6_type = res->f6i->fib6_type; |
| } |
| } |
| |
| static bool rt6_is_gw_or_nonexthop(const struct fib6_result *res) |
| { |
| return (res->f6i->fib6_flags & RTF_NONEXTHOP) || |
| res->nh->fib_nh_gw_family; |
| } |
| |
| #ifdef CONFIG_IPV6_ROUTE_INFO |
| int rt6_route_rcv(struct net_device *dev, u8 *opt, int len, |
| const struct in6_addr *gwaddr) |
| { |
| struct net *net = dev_net(dev); |
| struct route_info *rinfo = (struct route_info *) opt; |
| struct in6_addr prefix_buf, *prefix; |
| unsigned int pref; |
| unsigned long lifetime; |
| struct fib6_info *rt; |
| |
| if (len < sizeof(struct route_info)) { |
| return -EINVAL; |
| } |
| |
| /* Sanity check for prefix_len and length */ |
| if (rinfo->length > 3) { |
| return -EINVAL; |
| } else if (rinfo->prefix_len > 128) { |
| return -EINVAL; |
| } else if (rinfo->prefix_len > 64) { |
| if (rinfo->length < 2) { |
| return -EINVAL; |
| } |
| } else if (rinfo->prefix_len > 0) { |
| if (rinfo->length < 1) { |
| return -EINVAL; |
| } |
| } |
| |
| pref = rinfo->route_pref; |
| if (pref == ICMPV6_ROUTER_PREF_INVALID) |
| return -EINVAL; |
| |
| lifetime = addrconf_timeout_fixup(ntohl(rinfo->lifetime), HZ); |
| |
| if (rinfo->length == 3) |
| prefix = (struct in6_addr *)rinfo->prefix; |
| else { |
| /* this function is safe */ |
| ipv6_addr_prefix(&prefix_buf, |
| (struct in6_addr *)rinfo->prefix, |
| rinfo->prefix_len); |
| prefix = &prefix_buf; |
| } |
| |
| if (rinfo->prefix_len == 0) |
| rt = rt6_get_dflt_router(net, gwaddr, dev); |
| else |
| rt = rt6_get_route_info(net, prefix, rinfo->prefix_len, |
| gwaddr, dev); |
| |
| if (rt && !lifetime) { |
| ip6_del_rt(net, rt, false); |
| rt = NULL; |
| } |
| |
| if (!rt && lifetime) |
| rt = rt6_add_route_info(net, prefix, rinfo->prefix_len, gwaddr, |
| dev, pref); |
| else if (rt) |
| rt->fib6_flags = RTF_ROUTEINFO | |
| (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref); |
| |
| if (rt) { |
| if (!addrconf_finite_timeout(lifetime)) |
| fib6_clean_expires(rt); |
| else |
| fib6_set_expires(rt, jiffies + HZ * lifetime); |
| |
| fib6_info_release(rt); |
| } |
| return 0; |
| } |
| #endif |
| |
| /* |
| * Misc support functions |
| */ |
| |
| /* called with rcu_lock held */ |
| static struct net_device *ip6_rt_get_dev_rcu(const struct fib6_result *res) |
| { |
| struct net_device *dev = res->nh->fib_nh_dev; |
| |
| if (res->fib6_flags & (RTF_LOCAL | RTF_ANYCAST)) { |
| /* for copies of local routes, dst->dev needs to be the |
| * device if it is a master device, the master device if |
| * device is enslaved, and the loopback as the default |
| */ |
| if (netif_is_l3_slave(dev) && |
| !rt6_need_strict(&res->f6i->fib6_dst.addr)) |
| dev = l3mdev_master_dev_rcu(dev); |
| else if (!netif_is_l3_master(dev)) |
| dev = dev_net(dev)->loopback_dev; |
| /* last case is netif_is_l3_master(dev) is true in which |
| * case we want dev returned to be dev |
| */ |
| } |
| |
| return dev; |
| } |
| |
| static const int fib6_prop[RTN_MAX + 1] = { |
| [RTN_UNSPEC] = 0, |
| [RTN_UNICAST] = 0, |
| [RTN_LOCAL] = 0, |
| [RTN_BROADCAST] = 0, |
| [RTN_ANYCAST] = 0, |
| [RTN_MULTICAST] = 0, |
| [RTN_BLACKHOLE] = -EINVAL, |
| [RTN_UNREACHABLE] = -EHOSTUNREACH, |
| [RTN_PROHIBIT] = -EACCES, |
| [RTN_THROW] = -EAGAIN, |
| [RTN_NAT] = -EINVAL, |
| [RTN_XRESOLVE] = -EINVAL, |
| }; |
| |
| static int ip6_rt_type_to_error(u8 fib6_type) |
| { |
| return fib6_prop[fib6_type]; |
| } |
| |
| static unsigned short fib6_info_dst_flags(struct fib6_info *rt) |
| { |
| unsigned short flags = 0; |
| |
| if (rt->dst_nocount) |
| flags |= DST_NOCOUNT; |
| if (rt->dst_nopolicy) |
| flags |= DST_NOPOLICY; |
| |
| return flags; |
| } |
| |
| static void ip6_rt_init_dst_reject(struct rt6_info *rt, u8 fib6_type) |
| { |
| rt->dst.error = ip6_rt_type_to_error(fib6_type); |
| |
| switch (fib6_type) { |
| case RTN_BLACKHOLE: |
| rt->dst.output = dst_discard_out; |
| rt->dst.input = dst_discard; |
| break; |
| case RTN_PROHIBIT: |
| rt->dst.output = ip6_pkt_prohibit_out; |
| rt->dst.input = ip6_pkt_prohibit; |
| break; |
| case RTN_THROW: |
| case RTN_UNREACHABLE: |
| default: |
| rt->dst.output = ip6_pkt_discard_out; |
| rt->dst.input = ip6_pkt_discard; |
| break; |
| } |
| } |
| |
| static void ip6_rt_init_dst(struct rt6_info *rt, const struct fib6_result *res) |
| { |
| struct fib6_info *f6i = res->f6i; |
| |
| if (res->fib6_flags & RTF_REJECT) { |
| ip6_rt_init_dst_reject(rt, res->fib6_type); |
| return; |
| } |
| |
| rt->dst.error = 0; |
| rt->dst.output = ip6_output; |
| |
| if (res->fib6_type == RTN_LOCAL || res->fib6_type == RTN_ANYCAST) { |
| rt->dst.input = ip6_input; |
| } else if (ipv6_addr_type(&f6i->fib6_dst.addr) & IPV6_ADDR_MULTICAST) { |
| rt->dst.input = ip6_mc_input; |
| } else { |
| rt->dst.input = ip6_forward; |
| } |
| |
| if (res->nh->fib_nh_lws) { |
| rt->dst.lwtstate = lwtstate_get(res->nh->fib_nh_lws); |
| lwtunnel_set_redirect(&rt->dst); |
| } |
| |
| rt->dst.lastuse = jiffies; |
| } |
| |
| /* Caller must already hold reference to @from */ |
| static void rt6_set_from(struct rt6_info *rt, struct fib6_info *from) |
| { |
| rt->rt6i_flags &= ~RTF_EXPIRES; |
| rcu_assign_pointer(rt->from, from); |
| ip_dst_init_metrics(&rt->dst, from->fib6_metrics); |
| } |
| |
| /* Caller must already hold reference to f6i in result */ |
| static void ip6_rt_copy_init(struct rt6_info *rt, const struct fib6_result *res) |
| { |
| const struct fib6_nh *nh = res->nh; |
| const struct net_device *dev = nh->fib_nh_dev; |
| struct fib6_info *f6i = res->f6i; |
| |
| ip6_rt_init_dst(rt, res); |
| |
| rt->rt6i_dst = f6i->fib6_dst; |
| rt->rt6i_idev = dev ? in6_dev_get(dev) : NULL; |
| rt->rt6i_flags = res->fib6_flags; |
| if (nh->fib_nh_gw_family) { |
| rt->rt6i_gateway = nh->fib_nh_gw6; |
| rt->rt6i_flags |= RTF_GATEWAY; |
| } |
| rt6_set_from(rt, f6i); |
| #ifdef CONFIG_IPV6_SUBTREES |
| rt->rt6i_src = f6i->fib6_src; |
| #endif |
| } |
| |
| static struct fib6_node* fib6_backtrack(struct fib6_node *fn, |
| struct in6_addr *saddr) |
| { |
| struct fib6_node *pn, *sn; |
| while (1) { |
| if (fn->fn_flags & RTN_TL_ROOT) |
| return NULL; |
| pn = rcu_dereference(fn->parent); |
| sn = FIB6_SUBTREE(pn); |
| if (sn && sn != fn) |
| fn = fib6_node_lookup(sn, NULL, saddr); |
| else |
| fn = pn; |
| if (fn->fn_flags & RTN_RTINFO) |
| return fn; |
| } |
| } |
| |
| static bool ip6_hold_safe(struct net *net, struct rt6_info **prt) |
| { |
| struct rt6_info *rt = *prt; |
| |
| if (dst_hold_safe(&rt->dst)) |
| return true; |
| if (net) { |
| rt = net->ipv6.ip6_null_entry; |
| dst_hold(&rt->dst); |
| } else { |
| rt = NULL; |
| } |
| *prt = rt; |
| return false; |
| } |
| |
| /* called with rcu_lock held */ |
| static struct rt6_info *ip6_create_rt_rcu(const struct fib6_result *res) |
| { |
| struct net_device *dev = res->nh->fib_nh_dev; |
| struct fib6_info *f6i = res->f6i; |
| unsigned short flags; |
| struct rt6_info *nrt; |
| |
| if (!fib6_info_hold_safe(f6i)) |
| goto fallback; |
| |
| flags = fib6_info_dst_flags(f6i); |
| nrt = ip6_dst_alloc(dev_net(dev), dev, flags); |
| if (!nrt) { |
| fib6_info_release(f6i); |
| goto fallback; |
| } |
| |
| ip6_rt_copy_init(nrt, res); |
| return nrt; |
| |
| fallback: |
| nrt = dev_net(dev)->ipv6.ip6_null_entry; |
| dst_hold(&nrt->dst); |
| return nrt; |
| } |
| |
| INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_lookup(struct net *net, |
| struct fib6_table *table, |
| struct flowi6 *fl6, |
| const struct sk_buff *skb, |
| int flags) |
| { |
| struct fib6_result res = {}; |
| struct fib6_node *fn; |
| struct rt6_info *rt; |
| |
| if (fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF) |
| flags &= ~RT6_LOOKUP_F_IFACE; |
| |
| rcu_read_lock(); |
| fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr); |
| restart: |
| res.f6i = rcu_dereference(fn->leaf); |
| if (!res.f6i) |
| res.f6i = net->ipv6.fib6_null_entry; |
| else |
| rt6_device_match(net, &res, &fl6->saddr, fl6->flowi6_oif, |
| flags); |
| |
| if (res.f6i == net->ipv6.fib6_null_entry) { |
| fn = fib6_backtrack(fn, &fl6->saddr); |
| if (fn) |
| goto restart; |
| |
| rt = net->ipv6.ip6_null_entry; |
| dst_hold(&rt->dst); |
| goto out; |
| } else if (res.fib6_flags & RTF_REJECT) { |
| goto do_create; |
| } |
| |
| fib6_select_path(net, &res, fl6, fl6->flowi6_oif, |
| fl6->flowi6_oif != 0, skb, flags); |
| |
| /* Search through exception table */ |
| rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr); |
| if (rt) { |
| if (ip6_hold_safe(net, &rt)) |
| dst_use_noref(&rt->dst, jiffies); |
| } else { |
| do_create: |
| rt = ip6_create_rt_rcu(&res); |
| } |
| |
| out: |
| trace_fib6_table_lookup(net, &res, table, fl6); |
| |
| rcu_read_unlock(); |
| |
| return rt; |
| } |
| |
| struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6, |
| const struct sk_buff *skb, int flags) |
| { |
| return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_lookup); |
| } |
| EXPORT_SYMBOL_GPL(ip6_route_lookup); |
| |
| struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr, |
| const struct in6_addr *saddr, int oif, |
| const struct sk_buff *skb, int strict) |
| { |
| struct flowi6 fl6 = { |
| .flowi6_oif = oif, |
| .daddr = *daddr, |
| }; |
| struct dst_entry *dst; |
| int flags = strict ? RT6_LOOKUP_F_IFACE : 0; |
| |
| if (saddr) { |
| memcpy(&fl6.saddr, saddr, sizeof(*saddr)); |
| flags |= RT6_LOOKUP_F_HAS_SADDR; |
| } |
| |
| dst = fib6_rule_lookup(net, &fl6, skb, flags, ip6_pol_route_lookup); |
| if (dst->error == 0) |
| return (struct rt6_info *) dst; |
| |
| dst_release(dst); |
| |
| return NULL; |
| } |
| EXPORT_SYMBOL(rt6_lookup); |
| |
| /* ip6_ins_rt is called with FREE table->tb6_lock. |
| * It takes new route entry, the addition fails by any reason the |
| * route is released. |
| * Caller must hold dst before calling it. |
| */ |
| |
| static int __ip6_ins_rt(struct fib6_info *rt, struct nl_info *info, |
| struct netlink_ext_ack *extack) |
| { |
| int err; |
| struct fib6_table *table; |
| |
| table = rt->fib6_table; |
| spin_lock_bh(&table->tb6_lock); |
| err = fib6_add(&table->tb6_root, rt, info, extack); |
| spin_unlock_bh(&table->tb6_lock); |
| |
| return err; |
| } |
| |
| int ip6_ins_rt(struct net *net, struct fib6_info *rt) |
| { |
| struct nl_info info = { .nl_net = net, }; |
| |
| return __ip6_ins_rt(rt, &info, NULL); |
| } |
| |
| static struct rt6_info *ip6_rt_cache_alloc(const struct fib6_result *res, |
| const struct in6_addr *daddr, |
| const struct in6_addr *saddr) |
| { |
| struct fib6_info *f6i = res->f6i; |
| struct net_device *dev; |
| struct rt6_info *rt; |
| |
| /* |
| * Clone the route. |
| */ |
| |
| if (!fib6_info_hold_safe(f6i)) |
| return NULL; |
| |
| dev = ip6_rt_get_dev_rcu(res); |
| rt = ip6_dst_alloc(dev_net(dev), dev, 0); |
| if (!rt) { |
| fib6_info_release(f6i); |
| return NULL; |
| } |
| |
| ip6_rt_copy_init(rt, res); |
| rt->rt6i_flags |= RTF_CACHE; |
| rt->rt6i_dst.addr = *daddr; |
| rt->rt6i_dst.plen = 128; |
| |
| if (!rt6_is_gw_or_nonexthop(res)) { |
| if (f6i->fib6_dst.plen != 128 && |
| ipv6_addr_equal(&f6i->fib6_dst.addr, daddr)) |
| rt->rt6i_flags |= RTF_ANYCAST; |
| #ifdef CONFIG_IPV6_SUBTREES |
| if (rt->rt6i_src.plen && saddr) { |
| rt->rt6i_src.addr = *saddr; |
| rt->rt6i_src.plen = 128; |
| } |
| #endif |
| } |
| |
| return rt; |
| } |
| |
| static struct rt6_info *ip6_rt_pcpu_alloc(const struct fib6_result *res) |
| { |
| struct fib6_info *f6i = res->f6i; |
| unsigned short flags = fib6_info_dst_flags(f6i); |
| struct net_device *dev; |
| struct rt6_info *pcpu_rt; |
| |
| if (!fib6_info_hold_safe(f6i)) |
| return NULL; |
| |
| rcu_read_lock(); |
| dev = ip6_rt_get_dev_rcu(res); |
| pcpu_rt = ip6_dst_alloc(dev_net(dev), dev, flags | DST_NOCOUNT); |
| rcu_read_unlock(); |
| if (!pcpu_rt) { |
| fib6_info_release(f6i); |
| return NULL; |
| } |
| ip6_rt_copy_init(pcpu_rt, res); |
| pcpu_rt->rt6i_flags |= RTF_PCPU; |
| |
| if (f6i->nh) |
| pcpu_rt->sernum = rt_genid_ipv6(dev_net(dev)); |
| |
| return pcpu_rt; |
| } |
| |
| static bool rt6_is_valid(const struct rt6_info *rt6) |
| { |
| return rt6->sernum == rt_genid_ipv6(dev_net(rt6->dst.dev)); |
| } |
| |
| /* It should be called with rcu_read_lock() acquired */ |
| static struct rt6_info *rt6_get_pcpu_route(const struct fib6_result *res) |
| { |
| struct rt6_info *pcpu_rt; |
| |
| pcpu_rt = this_cpu_read(*res->nh->rt6i_pcpu); |
| |
| if (pcpu_rt && pcpu_rt->sernum && !rt6_is_valid(pcpu_rt)) { |
| struct rt6_info *prev, **p; |
| |
| p = this_cpu_ptr(res->nh->rt6i_pcpu); |
| prev = xchg(p, NULL); |
| if (prev) { |
| dst_dev_put(&prev->dst); |
| dst_release(&prev->dst); |
| } |
| |
| pcpu_rt = NULL; |
| } |
| |
| return pcpu_rt; |
| } |
| |
| static struct rt6_info *rt6_make_pcpu_route(struct net *net, |
| const struct fib6_result *res) |
| { |
| struct rt6_info *pcpu_rt, *prev, **p; |
| |
| pcpu_rt = ip6_rt_pcpu_alloc(res); |
| if (!pcpu_rt) |
| return NULL; |
| |
| p = this_cpu_ptr(res->nh->rt6i_pcpu); |
| prev = cmpxchg(p, NULL, pcpu_rt); |
| BUG_ON(prev); |
| |
| if (res->f6i->fib6_destroying) { |
| struct fib6_info *from; |
| |
| from = xchg((__force struct fib6_info **)&pcpu_rt->from, NULL); |
| fib6_info_release(from); |
| } |
| |
| return pcpu_rt; |
| } |
| |
| /* exception hash table implementation |
| */ |
| static DEFINE_SPINLOCK(rt6_exception_lock); |
| |
| /* Remove rt6_ex from hash table and free the memory |
| * Caller must hold rt6_exception_lock |
| */ |
| static void rt6_remove_exception(struct rt6_exception_bucket *bucket, |
| struct rt6_exception *rt6_ex) |
| { |
| struct fib6_info *from; |
| struct net *net; |
| |
| if (!bucket || !rt6_ex) |
| return; |
| |
| net = dev_net(rt6_ex->rt6i->dst.dev); |
| net->ipv6.rt6_stats->fib_rt_cache--; |
| |
| /* purge completely the exception to allow releasing the held resources: |
| * some [sk] cache may keep the dst around for unlimited time |
| */ |
| from = xchg((__force struct fib6_info **)&rt6_ex->rt6i->from, NULL); |
| fib6_info_release(from); |
| dst_dev_put(&rt6_ex->rt6i->dst); |
| |
| hlist_del_rcu(&rt6_ex->hlist); |
| dst_release(&rt6_ex->rt6i->dst); |
| kfree_rcu(rt6_ex, rcu); |
| WARN_ON_ONCE(!bucket->depth); |
| bucket->depth--; |
| } |
| |
| /* Remove oldest rt6_ex in bucket and free the memory |
| * Caller must hold rt6_exception_lock |
| */ |
| static void rt6_exception_remove_oldest(struct rt6_exception_bucket *bucket) |
| { |
| struct rt6_exception *rt6_ex, *oldest = NULL; |
| |
| if (!bucket) |
| return; |
| |
| hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) { |
| if (!oldest || time_before(rt6_ex->stamp, oldest->stamp)) |
| oldest = rt6_ex; |
| } |
| rt6_remove_exception(bucket, oldest); |
| } |
| |
| static u32 rt6_exception_hash(const struct in6_addr *dst, |
| const struct in6_addr *src) |
| { |
| static siphash_key_t rt6_exception_key __read_mostly; |
| struct { |
| struct in6_addr dst; |
| struct in6_addr src; |
| } __aligned(SIPHASH_ALIGNMENT) combined = { |
| .dst = *dst, |
| }; |
| u64 val; |
| |
| net_get_random_once(&rt6_exception_key, sizeof(rt6_exception_key)); |
| |
| #ifdef CONFIG_IPV6_SUBTREES |
| if (src) |
| combined.src = *src; |
| #endif |
| val = siphash(&combined, sizeof(combined), &rt6_exception_key); |
| |
| return hash_64(val, FIB6_EXCEPTION_BUCKET_SIZE_SHIFT); |
| } |
| |
| /* Helper function to find the cached rt in the hash table |
| * and update bucket pointer to point to the bucket for this |
| * (daddr, saddr) pair |
| * Caller must hold rt6_exception_lock |
| */ |
| static struct rt6_exception * |
| __rt6_find_exception_spinlock(struct rt6_exception_bucket **bucket, |
| const struct in6_addr *daddr, |
| const struct in6_addr *saddr) |
| { |
| struct rt6_exception *rt6_ex; |
| u32 hval; |
| |
| if (!(*bucket) || !daddr) |
| return NULL; |
| |
| hval = rt6_exception_hash(daddr, saddr); |
| *bucket += hval; |
| |
| hlist_for_each_entry(rt6_ex, &(*bucket)->chain, hlist) { |
| struct rt6_info *rt6 = rt6_ex->rt6i; |
| bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr); |
| |
| #ifdef CONFIG_IPV6_SUBTREES |
| if (matched && saddr) |
| matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr); |
| #endif |
| if (matched) |
| return rt6_ex; |
| } |
| return NULL; |
| } |
| |
| /* Helper function to find the cached rt in the hash table |
| * and update bucket pointer to point to the bucket for this |
| * (daddr, saddr) pair |
| * Caller must hold rcu_read_lock() |
| */ |
| static struct rt6_exception * |
| __rt6_find_exception_rcu(struct rt6_exception_bucket **bucket, |
| const struct in6_addr *daddr, |
| const struct in6_addr *saddr) |
| { |
| struct rt6_exception *rt6_ex; |
| u32 hval; |
| |
| WARN_ON_ONCE(!rcu_read_lock_held()); |
| |
| if (!(*bucket) || !daddr) |
| return NULL; |
| |
| hval = rt6_exception_hash(daddr, saddr); |
| *bucket += hval; |
| |
| hlist_for_each_entry_rcu(rt6_ex, &(*bucket)->chain, hlist) { |
| struct rt6_info *rt6 = rt6_ex->rt6i; |
| bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr); |
| |
| #ifdef CONFIG_IPV6_SUBTREES |
| if (matched && saddr) |
| matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr); |
| #endif |
| if (matched) |
| return rt6_ex; |
| } |
| return NULL; |
| } |
| |
| static unsigned int fib6_mtu(const struct fib6_result *res) |
| { |
| const struct fib6_nh *nh = res->nh; |
| unsigned int mtu; |
| |
| if (res->f6i->fib6_pmtu) { |
| mtu = res->f6i->fib6_pmtu; |
| } else { |
| struct net_device *dev = nh->fib_nh_dev; |
| struct inet6_dev *idev; |
| |
| rcu_read_lock(); |
| idev = __in6_dev_get(dev); |
| mtu = idev->cnf.mtu6; |
| rcu_read_unlock(); |
| } |
| |
| mtu = min_t(unsigned int, mtu, IP6_MAX_MTU); |
| |
| return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu); |
| } |
| |
| #define FIB6_EXCEPTION_BUCKET_FLUSHED 0x1UL |
| |
| /* used when the flushed bit is not relevant, only access to the bucket |
| * (ie., all bucket users except rt6_insert_exception); |
| * |
| * called under rcu lock; sometimes called with rt6_exception_lock held |
| */ |
| static |
| struct rt6_exception_bucket *fib6_nh_get_excptn_bucket(const struct fib6_nh *nh, |
| spinlock_t *lock) |
| { |
| struct rt6_exception_bucket *bucket; |
| |
| if (lock) |
| bucket = rcu_dereference_protected(nh->rt6i_exception_bucket, |
| lockdep_is_held(lock)); |
| else |
| bucket = rcu_dereference(nh->rt6i_exception_bucket); |
| |
| /* remove bucket flushed bit if set */ |
| if (bucket) { |
| unsigned long p = (unsigned long)bucket; |
| |
| p &= ~FIB6_EXCEPTION_BUCKET_FLUSHED; |
| bucket = (struct rt6_exception_bucket *)p; |
| } |
| |
| return bucket; |
| } |
| |
| static bool fib6_nh_excptn_bucket_flushed(struct rt6_exception_bucket *bucket) |
| { |
| unsigned long p = (unsigned long)bucket; |
| |
| return !!(p & FIB6_EXCEPTION_BUCKET_FLUSHED); |
| } |
| |
| /* called with rt6_exception_lock held */ |
| static void fib6_nh_excptn_bucket_set_flushed(struct fib6_nh *nh, |
| spinlock_t *lock) |
| { |
| struct rt6_exception_bucket *bucket; |
| unsigned long p; |
| |
| bucket = rcu_dereference_protected(nh->rt6i_exception_bucket, |
| lockdep_is_held(lock)); |
| |
| p = (unsigned long)bucket; |
| p |= FIB6_EXCEPTION_BUCKET_FLUSHED; |
| bucket = (struct rt6_exception_bucket *)p; |
| rcu_assign_pointer(nh->rt6i_exception_bucket, bucket); |
| } |
| |
| static int rt6_insert_exception(struct rt6_info *nrt, |
| const struct fib6_result *res) |
| { |
| struct net *net = dev_net(nrt->dst.dev); |
| struct rt6_exception_bucket *bucket; |
| struct fib6_info *f6i = res->f6i; |
| struct in6_addr *src_key = NULL; |
| struct rt6_exception *rt6_ex; |
| struct fib6_nh *nh = res->nh; |
| int max_depth; |
| int err = 0; |
| |
| spin_lock_bh(&rt6_exception_lock); |
| |
| bucket = rcu_dereference_protected(nh->rt6i_exception_bucket, |
| lockdep_is_held(&rt6_exception_lock)); |
| if (!bucket) { |
| bucket = kcalloc(FIB6_EXCEPTION_BUCKET_SIZE, sizeof(*bucket), |
| GFP_ATOMIC); |
| if (!bucket) { |
| err = -ENOMEM; |
| goto out; |
| } |
| rcu_assign_pointer(nh->rt6i_exception_bucket, bucket); |
| } else if (fib6_nh_excptn_bucket_flushed(bucket)) { |
| err = -EINVAL; |
| goto out; |
| } |
| |
| #ifdef CONFIG_IPV6_SUBTREES |
| /* fib6_src.plen != 0 indicates f6i is in subtree |
| * and exception table is indexed by a hash of |
| * both fib6_dst and fib6_src. |
| * Otherwise, the exception table is indexed by |
| * a hash of only fib6_dst. |
| */ |
| if (f6i->fib6_src.plen) |
| src_key = &nrt->rt6i_src.addr; |
| #endif |
| /* rt6_mtu_change() might lower mtu on f6i. |
| * Only insert this exception route if its mtu |
| * is less than f6i's mtu value. |
| */ |
| if (dst_metric_raw(&nrt->dst, RTAX_MTU) >= fib6_mtu(res)) { |
| err = -EINVAL; |
| goto out; |
| } |
| |
| rt6_ex = __rt6_find_exception_spinlock(&bucket, &nrt->rt6i_dst.addr, |
| src_key); |
| if (rt6_ex) |
| rt6_remove_exception(bucket, rt6_ex); |
| |
| rt6_ex = kzalloc(sizeof(*rt6_ex), GFP_ATOMIC); |
| if (!rt6_ex) { |
| err = -ENOMEM; |
| goto out; |
| } |
| rt6_ex->rt6i = nrt; |
| rt6_ex->stamp = jiffies; |
| hlist_add_head_rcu(&rt6_ex->hlist, &bucket->chain); |
| bucket->depth++; |
| net->ipv6.rt6_stats->fib_rt_cache++; |
| |
| /* Randomize max depth to avoid some side channels attacks. */ |
| max_depth = FIB6_MAX_DEPTH + prandom_u32_max(FIB6_MAX_DEPTH); |
| while (bucket->depth > max_depth) |
| rt6_exception_remove_oldest(bucket); |
| |
| out: |
| spin_unlock_bh(&rt6_exception_lock); |
| |
| /* Update fn->fn_sernum to invalidate all cached dst */ |
| if (!err) { |
| spin_lock_bh(&f6i->fib6_table->tb6_lock); |
| fib6_update_sernum(net, f6i); |
| spin_unlock_bh(&f6i->fib6_table->tb6_lock); |
| fib6_force_start_gc(net); |
| } |
| |
| return err; |
| } |
| |
| static void fib6_nh_flush_exceptions(struct fib6_nh *nh, struct fib6_info *from) |
| { |
| struct rt6_exception_bucket *bucket; |
| struct rt6_exception *rt6_ex; |
| struct hlist_node *tmp; |
| int i; |
| |
| spin_lock_bh(&rt6_exception_lock); |
| |
| bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock); |
| if (!bucket) |
| goto out; |
| |
| /* Prevent rt6_insert_exception() to recreate the bucket list */ |
| if (!from) |
| fib6_nh_excptn_bucket_set_flushed(nh, &rt6_exception_lock); |
| |
| for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) { |
| hlist_for_each_entry_safe(rt6_ex, tmp, &bucket->chain, hlist) { |
| if (!from || |
| rcu_access_pointer(rt6_ex->rt6i->from) == from) |
| rt6_remove_exception(bucket, rt6_ex); |
| } |
| WARN_ON_ONCE(!from && bucket->depth); |
| bucket++; |
| } |
| out: |
| spin_unlock_bh(&rt6_exception_lock); |
| } |
| |
| static int rt6_nh_flush_exceptions(struct fib6_nh *nh, void *arg) |
| { |
| struct fib6_info *f6i = arg; |
| |
| fib6_nh_flush_exceptions(nh, f6i); |
| |
| return 0; |
| } |
| |
| void rt6_flush_exceptions(struct fib6_info *f6i) |
| { |
| if (f6i->nh) |
| nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_flush_exceptions, |
| f6i); |
| else |
| fib6_nh_flush_exceptions(f6i->fib6_nh, f6i); |
| } |
| |
| /* Find cached rt in the hash table inside passed in rt |
| * Caller has to hold rcu_read_lock() |
| */ |
| static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res, |
| const struct in6_addr *daddr, |
| const struct in6_addr *saddr) |
| { |
| const struct in6_addr *src_key = NULL; |
| struct rt6_exception_bucket *bucket; |
| struct rt6_exception *rt6_ex; |
| struct rt6_info *ret = NULL; |
| |
| #ifdef CONFIG_IPV6_SUBTREES |
| /* fib6i_src.plen != 0 indicates f6i is in subtree |
| * and exception table is indexed by a hash of |
| * both fib6_dst and fib6_src. |
| * However, the src addr used to create the hash |
| * might not be exactly the passed in saddr which |
| * is a /128 addr from the flow. |
| * So we need to use f6i->fib6_src to redo lookup |
| * if the passed in saddr does not find anything. |
| * (See the logic in ip6_rt_cache_alloc() on how |
| * rt->rt6i_src is updated.) |
| */ |
| if (res->f6i->fib6_src.plen) |
| src_key = saddr; |
| find_ex: |
| #endif |
| bucket = fib6_nh_get_excptn_bucket(res->nh, NULL); |
| rt6_ex = __rt6_find_exception_rcu(&bucket, daddr, src_key); |
| |
| if (rt6_ex && !rt6_check_expired(rt6_ex->rt6i)) |
| ret = rt6_ex->rt6i; |
| |
| #ifdef CONFIG_IPV6_SUBTREES |
| /* Use fib6_src as src_key and redo lookup */ |
| if (!ret && src_key && src_key != &res->f6i->fib6_src.addr) { |
| src_key = &res->f6i->fib6_src.addr; |
| goto find_ex; |
| } |
| #endif |
| |
| return ret; |
| } |
| |
| /* Remove the passed in cached rt from the hash table that contains it */ |
| static int fib6_nh_remove_exception(const struct fib6_nh *nh, int plen, |
| const struct rt6_info *rt) |
| { |
| const struct in6_addr *src_key = NULL; |
| struct rt6_exception_bucket *bucket; |
| struct rt6_exception *rt6_ex; |
| int err; |
| |
| if (!rcu_access_pointer(nh->rt6i_exception_bucket)) |
| return -ENOENT; |
| |
| spin_lock_bh(&rt6_exception_lock); |
| bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock); |
| |
| #ifdef CONFIG_IPV6_SUBTREES |
| /* rt6i_src.plen != 0 indicates 'from' is in subtree |
| * and exception table is indexed by a hash of |
| * both rt6i_dst and rt6i_src. |
| * Otherwise, the exception table is indexed by |
| * a hash of only rt6i_dst. |
| */ |
| if (plen) |
| src_key = &rt->rt6i_src.addr; |
| #endif |
| rt6_ex = __rt6_find_exception_spinlock(&bucket, |
| &rt->rt6i_dst.addr, |
| src_key); |
| if (rt6_ex) { |
| rt6_remove_exception(bucket, rt6_ex); |
| err = 0; |
| } else { |
| err = -ENOENT; |
| } |
| |
| spin_unlock_bh(&rt6_exception_lock); |
| return err; |
| } |
| |
| struct fib6_nh_excptn_arg { |
| struct rt6_info *rt; |
| int plen; |
| }; |
| |
| static int rt6_nh_remove_exception_rt(struct fib6_nh *nh, void *_arg) |
| { |
| struct fib6_nh_excptn_arg *arg = _arg; |
| int err; |
| |
| err = fib6_nh_remove_exception(nh, arg->plen, arg->rt); |
| if (err == 0) |
| return 1; |
| |
| return 0; |
| } |
| |
| static int rt6_remove_exception_rt(struct rt6_info *rt) |
| { |
| struct fib6_info *from; |
| |
| from = rcu_dereference(rt->from); |
| if (!from || !(rt->rt6i_flags & RTF_CACHE)) |
| return -EINVAL; |
| |
| if (from->nh) { |
| struct fib6_nh_excptn_arg arg = { |
| .rt = rt, |
| .plen = from->fib6_src.plen |
| }; |
| int rc; |
| |
| /* rc = 1 means an entry was found */ |
| rc = nexthop_for_each_fib6_nh(from->nh, |
| rt6_nh_remove_exception_rt, |
| &arg); |
| return rc ? 0 : -ENOENT; |
| } |
| |
| return fib6_nh_remove_exception(from->fib6_nh, |
| from->fib6_src.plen, rt); |
| } |
| |
| /* Find rt6_ex which contains the passed in rt cache and |
| * refresh its stamp |
| */ |
| static void fib6_nh_update_exception(const struct fib6_nh *nh, int plen, |
| const struct rt6_info *rt) |
| { |
| const struct in6_addr *src_key = NULL; |
| struct rt6_exception_bucket *bucket; |
| struct rt6_exception *rt6_ex; |
| |
| bucket = fib6_nh_get_excptn_bucket(nh, NULL); |
| #ifdef CONFIG_IPV6_SUBTREES |
| /* rt6i_src.plen != 0 indicates 'from' is in subtree |
| * and exception table is indexed by a hash of |
| * both rt6i_dst and rt6i_src. |
| * Otherwise, the exception table is indexed by |
| * a hash of only rt6i_dst. |
| */ |
| if (plen) |
| src_key = &rt->rt6i_src.addr; |
| #endif |
| rt6_ex = __rt6_find_exception_rcu(&bucket, &rt->rt6i_dst.addr, src_key); |
| if (rt6_ex) |
| rt6_ex->stamp = jiffies; |
| } |
| |
| struct fib6_nh_match_arg { |
| const struct net_device *dev; |
| const struct in6_addr *gw; |
| struct fib6_nh *match; |
| }; |
| |
| /* determine if fib6_nh has given device and gateway */ |
| static int fib6_nh_find_match(struct fib6_nh *nh, void *_arg) |
| { |
| struct fib6_nh_match_arg *arg = _arg; |
| |
| if (arg->dev != nh->fib_nh_dev || |
| (arg->gw && !nh->fib_nh_gw_family) || |
| (!arg->gw && nh->fib_nh_gw_family) || |
| (arg->gw && !ipv6_addr_equal(arg->gw, &nh->fib_nh_gw6))) |
| return 0; |
| |
| arg->match = nh; |
| |
| /* found a match, break the loop */ |
| return 1; |
| } |
| |
| static void rt6_update_exception_stamp_rt(struct rt6_info *rt) |
| { |
| struct fib6_info *from; |
| struct fib6_nh *fib6_nh; |
| |
| rcu_read_lock(); |
| |
| from = rcu_dereference(rt->from); |
| if (!from || !(rt->rt6i_flags & RTF_CACHE)) |
| goto unlock; |
| |
| if (from->nh) { |
| struct fib6_nh_match_arg arg = { |
| .dev = rt->dst.dev, |
| .gw = &rt->rt6i_gateway, |
| }; |
| |
| nexthop_for_each_fib6_nh(from->nh, fib6_nh_find_match, &arg); |
| |
| if (!arg.match) |
| goto unlock; |
| fib6_nh = arg.match; |
| } else { |
| fib6_nh = from->fib6_nh; |
| } |
| fib6_nh_update_exception(fib6_nh, from->fib6_src.plen, rt); |
| unlock: |
| rcu_read_unlock(); |
| } |
| |
| static bool rt6_mtu_change_route_allowed(struct inet6_dev *idev, |
| struct rt6_info *rt, int mtu) |
| { |
| /* If the new MTU is lower than the route PMTU, this new MTU will be the |
| * lowest MTU in the path: always allow updating the route PMTU to |
| * reflect PMTU decreases. |
| * |
| * If the new MTU is higher, and the route PMTU is equal to the local |
| * MTU, this means the old MTU is the lowest in the path, so allow |
| * updating it: if other nodes now have lower MTUs, PMTU discovery will |
| * handle this. |
| */ |
| |
| if (dst_mtu(&rt->dst) >= mtu) |
| return true; |
| |
| if (dst_mtu(&rt->dst) == idev->cnf.mtu6) |
| return true; |
| |
| return false; |
| } |
| |
| static void rt6_exceptions_update_pmtu(struct inet6_dev *idev, |
| const struct fib6_nh *nh, int mtu) |
| { |
| struct rt6_exception_bucket *bucket; |
| struct rt6_exception *rt6_ex; |
| int i; |
| |
| bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock); |
| if (!bucket) |
| return; |
| |
| for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) { |
| hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) { |
| struct rt6_info *entry = rt6_ex->rt6i; |
| |
| /* For RTF_CACHE with rt6i_pmtu == 0 (i.e. a redirected |
| * route), the metrics of its rt->from have already |
| * been updated. |
| */ |
| if (dst_metric_raw(&entry->dst, RTAX_MTU) && |
| rt6_mtu_change_route_allowed(idev, entry, mtu)) |
| dst_metric_set(&entry->dst, RTAX_MTU, mtu); |
| } |
| bucket++; |
| } |
| } |
| |
| #define RTF_CACHE_GATEWAY (RTF_GATEWAY | RTF_CACHE) |
| |
| static void fib6_nh_exceptions_clean_tohost(const struct fib6_nh *nh, |
| const struct in6_addr *gateway) |
| { |
| struct rt6_exception_bucket *bucket; |
| struct rt6_exception *rt6_ex; |
| struct hlist_node *tmp; |
| int i; |
| |
| if (!rcu_access_pointer(nh->rt6i_exception_bucket)) |
| return; |
| |
| spin_lock_bh(&rt6_exception_lock); |
| bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock); |
| if (bucket) { |
| for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) { |
| hlist_for_each_entry_safe(rt6_ex, tmp, |
| &bucket->chain, hlist) { |
| struct rt6_info *entry = rt6_ex->rt6i; |
| |
| if ((entry->rt6i_flags & RTF_CACHE_GATEWAY) == |
| RTF_CACHE_GATEWAY && |
| ipv6_addr_equal(gateway, |
| &entry->rt6i_gateway)) { |
| rt6_remove_exception(bucket, rt6_ex); |
| } |
| } |
| bucket++; |
| } |
| } |
| |
| spin_unlock_bh(&rt6_exception_lock); |
| } |
| |
| static void rt6_age_examine_exception(struct rt6_exception_bucket *bucket, |
| struct rt6_exception *rt6_ex, |
| struct fib6_gc_args *gc_args, |
| unsigned long now) |
| { |
| struct rt6_info *rt = rt6_ex->rt6i; |
| |
| /* we are pruning and obsoleting aged-out and non gateway exceptions |
| * even if others have still references to them, so that on next |
| * dst_check() such references can be dropped. |
| * EXPIRES exceptions - e.g. pmtu-generated ones are pruned when |
| * expired, independently from their aging, as per RFC 8201 section 4 |
| */ |
| if (!(rt->rt6i_flags & RTF_EXPIRES)) { |
| if (time_after_eq(now, rt->dst.lastuse + gc_args->timeout)) { |
| RT6_TRACE("aging clone %p\n", rt); |
| rt6_remove_exception(bucket, rt6_ex); |
| return; |
| } |
| } else if (time_after(jiffies, rt->dst.expires)) { |
| RT6_TRACE("purging expired route %p\n", rt); |
| rt6_remove_exception(bucket, rt6_ex); |
| return; |
| } |
| |
| if (rt->rt6i_flags & RTF_GATEWAY) { |
| struct neighbour *neigh; |
| |
| neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway); |
| |
| if (!(neigh && (neigh->flags & NTF_ROUTER))) { |
| RT6_TRACE("purging route %p via non-router but gateway\n", |
| rt); |
| rt6_remove_exception(bucket, rt6_ex); |
| return; |
| } |
| } |
| |
| gc_args->more++; |
| } |
| |
| static void fib6_nh_age_exceptions(const struct fib6_nh *nh, |
| struct fib6_gc_args *gc_args, |
| unsigned long now) |
| { |
| struct rt6_exception_bucket *bucket; |
| struct rt6_exception *rt6_ex; |
| struct hlist_node *tmp; |
| int i; |
| |
| if (!rcu_access_pointer(nh->rt6i_exception_bucket)) |
| return; |
| |
| rcu_read_lock_bh(); |
| spin_lock(&rt6_exception_lock); |
| bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock); |
| if (bucket) { |
| for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) { |
| hlist_for_each_entry_safe(rt6_ex, tmp, |
| &bucket->chain, hlist) { |
| rt6_age_examine_exception(bucket, rt6_ex, |
| gc_args, now); |
| } |
| bucket++; |
| } |
| } |
| spin_unlock(&rt6_exception_lock); |
| rcu_read_unlock_bh(); |
| } |
| |
| struct fib6_nh_age_excptn_arg { |
| struct fib6_gc_args *gc_args; |
| unsigned long now; |
| }; |
| |
| static int rt6_nh_age_exceptions(struct fib6_nh *nh, void *_arg) |
| { |
| struct fib6_nh_age_excptn_arg *arg = _arg; |
| |
| fib6_nh_age_exceptions(nh, arg->gc_args, arg->now); |
| return 0; |
| } |
| |
| void rt6_age_exceptions(struct fib6_info *f6i, |
| struct fib6_gc_args *gc_args, |
| unsigned long now) |
| { |
| if (f6i->nh) { |
| struct fib6_nh_age_excptn_arg arg = { |
| .gc_args = gc_args, |
| .now = now |
| }; |
| |
| nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_age_exceptions, |
| &arg); |
| } else { |
| fib6_nh_age_exceptions(f6i->fib6_nh, gc_args, now); |
| } |
| } |
| |
| /* must be called with rcu lock held */ |
| int fib6_table_lookup(struct net *net, struct fib6_table *table, int oif, |
| struct flowi6 *fl6, struct fib6_result *res, int strict) |
| { |
| struct fib6_node *fn, *saved_fn; |
| |
| fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr); |
| saved_fn = fn; |
| |
| if (fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF) |
| oif = 0; |
| |
| redo_rt6_select: |
| rt6_select(net, fn, oif, res, strict); |
| if (res->f6i == net->ipv6.fib6_null_entry) { |
| fn = fib6_backtrack(fn, &fl6->saddr); |
| if (fn) |
| goto redo_rt6_select; |
| else if (strict & RT6_LOOKUP_F_REACHABLE) { |
| /* also consider unreachable route */ |
| strict &= ~RT6_LOOKUP_F_REACHABLE; |
| fn = saved_fn; |
| goto redo_rt6_select; |
| } |
| } |
| |
| trace_fib6_table_lookup(net, res, table, fl6); |
| |
| return 0; |
| } |
| |
| struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table, |
| int oif, struct flowi6 *fl6, |
| const struct sk_buff *skb, int flags) |
| { |
| struct fib6_result res = {}; |
| struct rt6_info *rt = NULL; |
| int strict = 0; |
| |
| WARN_ON_ONCE((flags & RT6_LOOKUP_F_DST_NOREF) && |
| !rcu_read_lock_held()); |
| |
| strict |= flags & RT6_LOOKUP_F_IFACE; |
| strict |= flags & RT6_LOOKUP_F_IGNORE_LINKSTATE; |
| if (net->ipv6.devconf_all->forwarding == 0) |
| strict |= RT6_LOOKUP_F_REACHABLE; |
| |
| rcu_read_lock(); |
| |
| fib6_table_lookup(net, table, oif, fl6, &res, strict); |
| if (res.f6i == net->ipv6.fib6_null_entry) |
| goto out; |
| |
| fib6_select_path(net, &res, fl6, oif, false, skb, strict); |
| |
| /*Search through exception table */ |
| rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr); |
| if (rt) { |
| goto out; |
| } else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) && |
| !res.nh->fib_nh_gw_family)) { |
| /* Create a RTF_CACHE clone which will not be |
| * owned by the fib6 tree. It is for the special case where |
| * the daddr in the skb during the neighbor look-up is different |
| * from the fl6->daddr used to look-up route here. |
| */ |
| rt = ip6_rt_cache_alloc(&res, &fl6->daddr, NULL); |
| |
| if (rt) { |
| /* 1 refcnt is taken during ip6_rt_cache_alloc(). |
| * As rt6_uncached_list_add() does not consume refcnt, |
| * this refcnt is always returned to the caller even |
| * if caller sets RT6_LOOKUP_F_DST_NOREF flag. |
| */ |
| rt6_uncached_list_add(rt); |
| atomic_inc(&net->ipv6.rt6_stats->fib_rt_uncache); |
| rcu_read_unlock(); |
| |
| return rt; |
| } |
| } else { |
| /* Get a percpu copy */ |
| local_bh_disable(); |
| rt = rt6_get_pcpu_route(&res); |
| |
| if (!rt) |
| rt = rt6_make_pcpu_route(net, &res); |
| |
| local_bh_enable(); |
| } |
| out: |
| if (!rt) |
| rt = net->ipv6.ip6_null_entry; |
| if (!(flags & RT6_LOOKUP_F_DST_NOREF)) |
| ip6_hold_safe(net, &rt); |
| rcu_read_unlock(); |
| |
| return rt; |
| } |
| EXPORT_SYMBOL_GPL(ip6_pol_route); |
| |
| INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_input(struct net *net, |
| struct fib6_table *table, |
| struct flowi6 *fl6, |
| const struct sk_buff *skb, |
| int flags) |
| { |
| return ip6_pol_route(net, table, fl6->flowi6_iif, fl6, skb, flags); |
| } |
| |
| struct dst_entry *ip6_route_input_lookup(struct net *net, |
| struct net_device *dev, |
| struct flowi6 *fl6, |
| const struct sk_buff *skb, |
| int flags) |
| { |
| if (rt6_need_strict(&fl6->daddr) && dev->type != ARPHRD_PIMREG) |
| flags |= RT6_LOOKUP_F_IFACE; |
| |
| return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_input); |
| } |
| EXPORT_SYMBOL_GPL(ip6_route_input_lookup); |
| |
| static void ip6_multipath_l3_keys(const struct sk_buff *skb, |
| struct flow_keys *keys, |
| struct flow_keys *flkeys) |
| { |
| const struct ipv6hdr *outer_iph = ipv6_hdr(skb); |
| const struct ipv6hdr *key_iph = outer_iph; |
| struct flow_keys *_flkeys = flkeys; |
| const struct ipv6hdr *inner_iph; |
| const struct icmp6hdr *icmph; |
| struct ipv6hdr _inner_iph; |
| struct icmp6hdr _icmph; |
| |
| if (likely(outer_iph->nexthdr != IPPROTO_ICMPV6)) |
| goto out; |
| |
| icmph = skb_header_pointer(skb, skb_transport_offset(skb), |
| sizeof(_icmph), &_icmph); |
| if (!icmph) |
| goto out; |
| |
| if (!icmpv6_is_err(icmph->icmp6_type)) |
| goto out; |
| |
| inner_iph = skb_header_pointer(skb, |
| skb_transport_offset(skb) + sizeof(*icmph), |
| sizeof(_inner_iph), &_inner_iph); |
| if (!inner_iph) |
| goto out; |
| |
| key_iph = inner_iph; |
| _flkeys = NULL; |
| out: |
| if (_flkeys) { |
| keys->addrs.v6addrs.src = _flkeys->addrs.v6addrs.src; |
| keys->addrs.v6addrs.dst = _flkeys->addrs.v6addrs.dst; |
| keys->tags.flow_label = _flkeys->tags.flow_label; |
| keys->basic.ip_proto = _flkeys->basic.ip_proto; |
| } else { |
| keys->addrs.v6addrs.src = key_iph->saddr; |
| keys->addrs.v6addrs.dst = key_iph->daddr; |
| keys->tags.flow_label = ip6_flowlabel(key_iph); |
| keys->basic.ip_proto = key_iph->nexthdr; |
| } |
| } |
| |
| static u32 rt6_multipath_custom_hash_outer(const struct net *net, |
| const struct sk_buff *skb, |
| bool *p_has_inner) |
| { |
| u32 hash_fields = ip6_multipath_hash_fields(net); |
| struct flow_keys keys, hash_keys; |
| |
| if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) |
| return 0; |
| |
| memset(&hash_keys, 0, sizeof(hash_keys)); |
| skb_flow_dissect_flow_keys(skb, &keys, FLOW_DISSECTOR_F_STOP_AT_ENCAP); |
| |
| hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; |
| if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) |
| hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; |
| if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) |
| hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; |
| if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) |
| hash_keys.basic.ip_proto = keys.basic.ip_proto; |
| if (hash_fields & FIB_MULTIPATH_HASH_FIELD_FLOWLABEL) |
| hash_keys.tags.flow_label = keys.tags.flow_label; |
| if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) |
| hash_keys.ports.src = keys.ports.src; |
| if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) |
| hash_keys.ports.dst = keys.ports.dst; |
| |
| *p_has_inner = !!(keys.control.flags & FLOW_DIS_ENCAPSULATION); |
| return flow_hash_from_keys(&hash_keys); |
| } |
| |
| static u32 rt6_multipath_custom_hash_inner(const struct net *net, |
| const struct sk_buff *skb, |
| bool has_inner) |
| { |
| u32 hash_fields = ip6_multipath_hash_fields(net); |
| struct flow_keys keys, hash_keys; |
| |
| /* We assume the packet carries an encapsulation, but if none was |
| * encountered during dissection of the outer flow, then there is no |
| * point in calling the flow dissector again. |
| */ |
| if (!has_inner) |
| return 0; |
| |
| if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_MASK)) |
| return 0; |
| |
| memset(&hash_keys, 0, sizeof(hash_keys)); |
| skb_flow_dissect_flow_keys(skb, &keys, 0); |
| |
| if (!(keys.control.flags & FLOW_DIS_ENCAPSULATION)) |
| return 0; |
| |
| if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { |
| hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; |
| if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) |
| hash_keys.addrs.v4addrs.src = keys.addrs.v4addrs.src; |
| if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) |
| hash_keys.addrs.v4addrs.dst = keys.addrs.v4addrs.dst; |
| } else if (keys.control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { |
| hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; |
| if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_IP) |
| hash_keys.addrs.v6addrs.src = keys.addrs.v6addrs.src; |
| if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_IP) |
| hash_keys.addrs.v6addrs.dst = keys.addrs.v6addrs.dst; |
| if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_FLOWLABEL) |
| hash_keys.tags.flow_label = keys.tags.flow_label; |
| } |
| |
| if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_IP_PROTO) |
| hash_keys.basic.ip_proto = keys.basic.ip_proto; |
| if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_SRC_PORT) |
| hash_keys.ports.src = keys.ports.src; |
| if (hash_fields & FIB_MULTIPATH_HASH_FIELD_INNER_DST_PORT) |
| hash_keys.ports.dst = keys.ports.dst; |
| |
| return flow_hash_from_keys(&hash_keys); |
| } |
| |
| static u32 rt6_multipath_custom_hash_skb(const struct net *net, |
| const struct sk_buff *skb) |
| { |
| u32 mhash, mhash_inner; |
| bool has_inner = true; |
| |
| mhash = rt6_multipath_custom_hash_outer(net, skb, &has_inner); |
| mhash_inner = rt6_multipath_custom_hash_inner(net, skb, has_inner); |
| |
| return jhash_2words(mhash, mhash_inner, 0); |
| } |
| |
| static u32 rt6_multipath_custom_hash_fl6(const struct net *net, |
| const struct flowi6 *fl6) |
| { |
| u32 hash_fields = ip6_multipath_hash_fields(net); |
| struct flow_keys hash_keys; |
| |
| if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK)) |
| return 0; |
| |
| memset(&hash_keys, 0, sizeof(hash_keys)); |
| hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; |
| if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_IP) |
| hash_keys.addrs.v6addrs.src = fl6->saddr; |
| if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_IP) |
| hash_keys.addrs.v6addrs.dst = fl6->daddr; |
| if (hash_fields & FIB_MULTIPATH_HASH_FIELD_IP_PROTO) |
| hash_keys.basic.ip_proto = fl6->flowi6_proto; |
| if (hash_fields & FIB_MULTIPATH_HASH_FIELD_FLOWLABEL) |
| hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6); |
| if (hash_fields & FIB_MULTIPATH_HASH_FIELD_SRC_PORT) |
| hash_keys.ports.src = fl6->fl6_sport; |
| if (hash_fields & FIB_MULTIPATH_HASH_FIELD_DST_PORT) |
| hash_keys.ports.dst = fl6->fl6_dport; |
| |
| return flow_hash_from_keys(&hash_keys); |
| } |
| |
| /* if skb is set it will be used and fl6 can be NULL */ |
| u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6, |
| const struct sk_buff *skb, struct flow_keys *flkeys) |
| { |
| struct flow_keys hash_keys; |
| u32 mhash = 0; |
| |
| switch (ip6_multipath_hash_policy(net)) { |
| case 0: |
| memset(&hash_keys, 0, sizeof(hash_keys)); |
| hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; |
| if (skb) { |
| ip6_multipath_l3_keys(skb, &hash_keys, flkeys); |
| } else { |
| hash_keys.addrs.v6addrs.src = fl6->saddr; |
| hash_keys.addrs.v6addrs.dst = fl6->daddr; |
| hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6); |
| hash_keys.basic.ip_proto = fl6->flowi6_proto; |
| } |
| mhash = flow_hash_from_keys(&hash_keys); |
| break; |
| case 1: |
| if (skb) { |
| unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP; |
| struct flow_keys keys; |
| |
| /* short-circuit if we already have L4 hash present */ |
| if (skb->l4_hash) |
| return skb_get_hash_raw(skb) >> 1; |
| |
| memset(&hash_keys, 0, sizeof(hash_keys)); |
| |
| if (!flkeys) { |
| skb_flow_dissect_flow_keys(skb, &keys, flag); |
| flkeys = &keys; |
| } |
| hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; |
| hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src; |
| hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst; |
| hash_keys.ports.src = flkeys->ports.src; |
| hash_keys.ports.dst = flkeys->ports.dst; |
| hash_keys.basic.ip_proto = flkeys->basic.ip_proto; |
| } else { |
| memset(&hash_keys, 0, sizeof(hash_keys)); |
| hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; |
| hash_keys.addrs.v6addrs.src = fl6->saddr; |
| hash_keys.addrs.v6addrs.dst = fl6->daddr; |
| hash_keys.ports.src = fl6->fl6_sport; |
| hash_keys.ports.dst = fl6->fl6_dport; |
| hash_keys.basic.ip_proto = fl6->flowi6_proto; |
| } |
| mhash = flow_hash_from_keys(&hash_keys); |
| break; |
| case 2: |
| memset(&hash_keys, 0, sizeof(hash_keys)); |
| hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; |
| if (skb) { |
| struct flow_keys keys; |
| |
| if (!flkeys) { |
| skb_flow_dissect_flow_keys(skb, &keys, 0); |
| flkeys = &keys; |
| } |
| |
| /* Inner can be v4 or v6 */ |
| if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) { |
| hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS; |
| hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src; |
| hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst; |
| } else if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) { |
| hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; |
| hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src; |
| hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst; |
| hash_keys.tags.flow_label = flkeys->tags.flow_label; |
| hash_keys.basic.ip_proto = flkeys->basic.ip_proto; |
| } else { |
| /* Same as case 0 */ |
| hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; |
| ip6_multipath_l3_keys(skb, &hash_keys, flkeys); |
| } |
| } else { |
| /* Same as case 0 */ |
| hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS; |
| hash_keys.addrs.v6addrs.src = fl6->saddr; |
| hash_keys.addrs.v6addrs.dst = fl6->daddr; |
| hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6); |
| hash_keys.basic.ip_proto = fl6->flowi6_proto; |
| } |
| mhash = flow_hash_from_keys(&hash_keys); |
| break; |
| case 3: |
| if (skb) |
| mhash = rt6_multipath_custom_hash_skb(net, skb); |
| else |
| mhash = rt6_multipath_custom_hash_fl6(net, fl6); |
| break; |
| } |
| |
| return mhash >> 1; |
| } |
| |
| /* Called with rcu held */ |
| void ip6_route_input(struct sk_buff *skb) |
| { |
| const struct ipv6hdr *iph = ipv6_hdr(skb); |
| struct net *net = dev_net(skb->dev); |
| int flags = RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_DST_NOREF; |
| struct ip_tunnel_info *tun_info; |
| struct flowi6 fl6 = { |
| .flowi6_iif = skb->dev->ifindex, |
| .daddr = iph->daddr, |
| .saddr = iph->saddr, |
| .flowlabel = ip6_flowinfo(iph), |
| .flowi6_mark = skb->mark, |
| .flowi6_proto = iph->nexthdr, |
| }; |
| struct flow_keys *flkeys = NULL, _flkeys; |
| |
| tun_info = skb_tunnel_info(skb); |
| if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) |
| fl6.flowi6_tun_key.tun_id = tun_info->key.tun_id; |
| |
| if (fib6_rules_early_flow_dissect(net, skb, &fl6, &_flkeys)) |
| flkeys = &_flkeys; |
| |
| if (unlikely(fl6.flowi6_proto == IPPROTO_ICMPV6)) |
| fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, flkeys); |
| skb_dst_drop(skb); |
| skb_dst_set_noref(skb, ip6_route_input_lookup(net, skb->dev, |
| &fl6, skb, flags)); |
| } |
| |
| INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_output(struct net *net, |
| struct fib6_table *table, |
| struct flowi6 *fl6, |
| const struct sk_buff *skb, |
| int flags) |
| { |
| return ip6_pol_route(net, table, fl6->flowi6_oif, fl6, skb, flags); |
| } |
| |
| struct dst_entry *ip6_route_output_flags_noref(struct net *net, |
| const struct sock *sk, |
| struct flowi6 *fl6, int flags) |
| { |
| bool any_src; |
| |
| if (ipv6_addr_type(&fl6->daddr) & |
| (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL)) { |
| struct dst_entry *dst; |
| |
| /* This function does not take refcnt on the dst */ |
| dst = l3mdev_link_scope_lookup(net, fl6); |
| if (dst) |
| return dst; |
| } |
| |
| fl6->flowi6_iif = LOOPBACK_IFINDEX; |
| |
| flags |= RT6_LOOKUP_F_DST_NOREF; |
| any_src = ipv6_addr_any(&fl6->saddr); |
| if ((sk && sk->sk_bound_dev_if) || rt6_need_strict(&fl6->daddr) || |
| (fl6->flowi6_oif && any_src)) |
| flags |= RT6_LOOKUP_F_IFACE; |
| |
| if (!any_src) |
| flags |= RT6_LOOKUP_F_HAS_SADDR; |
| else if (sk) |
| flags |= rt6_srcprefs2flags(inet6_sk(sk)->srcprefs); |
| |
| return fib6_rule_lookup(net, fl6, NULL, flags, ip6_pol_route_output); |
| } |
| EXPORT_SYMBOL_GPL(ip6_route_output_flags_noref); |
| |
| struct dst_entry *ip6_route_output_flags(struct net *net, |
| const struct sock *sk, |
| struct flowi6 *fl6, |
| int flags) |
| { |
| struct dst_entry *dst; |
| struct rt6_info *rt6; |
| |
| rcu_read_lock(); |
| dst = ip6_route_output_flags_noref(net, sk, fl6, flags); |
| rt6 = (struct rt6_info *)dst; |
| /* For dst cached in uncached_list, refcnt is already taken. */ |
| if (list_empty(&rt6->rt6i_uncached) && !dst_hold_safe(dst)) { |
| dst = &net->ipv6.ip6_null_entry->dst; |
| dst_hold(dst); |
| } |
| rcu_read_unlock(); |
| |
| return dst; |
| } |
| EXPORT_SYMBOL_GPL(ip6_route_output_flags); |
| |
| struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_orig) |
| { |
| struct rt6_info *rt, *ort = (struct rt6_info *) dst_orig; |
| struct net_device *loopback_dev = net->loopback_dev; |
| struct dst_entry *new = NULL; |
| |
| rt = dst_alloc(&ip6_dst_blackhole_ops, loopback_dev, 1, |
| DST_OBSOLETE_DEAD, 0); |
| if (rt) { |
| rt6_info_init(rt); |
| atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc); |
| |
| new = &rt->dst; |
| new->__use = 1; |
| new->input = dst_discard; |
| new->output = dst_discard_out; |
| |
| dst_copy_metrics(new, &ort->dst); |
| |
| rt->rt6i_idev = in6_dev_get(loopback_dev); |
| rt->rt6i_gateway = ort->rt6i_gateway; |
| rt->rt6i_flags = ort->rt6i_flags & ~RTF_PCPU; |
| |
| memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key)); |
| #ifdef CONFIG_IPV6_SUBTREES |
| memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key)); |
| #endif |
| } |
| |
| dst_release(dst_orig); |
| return new ? new : ERR_PTR(-ENOMEM); |
| } |
| |
| /* |
| * Destination cache support functions |
| */ |
| |
| static bool fib6_check(struct fib6_info *f6i, u32 cookie) |
| { |
| u32 rt_cookie = 0; |
| |
| if (!fib6_get_cookie_safe(f6i, &rt_cookie) || rt_cookie != cookie) |
| return false; |
| |
| if (fib6_check_expired(f6i)) |
| return false; |
| |
| return true; |
| } |
| |
| static struct dst_entry *rt6_check(struct rt6_info *rt, |
| struct fib6_info *from, |
| u32 cookie) |
| { |
| u32 rt_cookie = 0; |
| |
| if (!from || !fib6_get_cookie_safe(from, &rt_cookie) || |
| rt_cookie != cookie) |
| return NULL; |
| |
| if (rt6_check_expired(rt)) |
| return NULL; |
| |
| return &rt->dst; |
| } |
| |
| static struct dst_entry *rt6_dst_from_check(struct rt6_info *rt, |
| struct fib6_info *from, |
| u32 cookie) |
| { |
| if (!__rt6_check_expired(rt) && |
| rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK && |
| fib6_check(from, cookie)) |
| return &rt->dst; |
| else |
| return NULL; |
| } |
| |
| INDIRECT_CALLABLE_SCOPE struct dst_entry *ip6_dst_check(struct dst_entry *dst, |
| u32 cookie) |
| { |
| struct dst_entry *dst_ret; |
| struct fib6_info *from; |
| struct rt6_info *rt; |
| |
| rt = container_of(dst, struct rt6_info, dst); |
| |
| if (rt->sernum) |
| return rt6_is_valid(rt) ? dst : NULL; |
| |
| rcu_read_lock(); |
| |
| /* All IPV6 dsts are created with ->obsolete set to the value |
| * DST_OBSOLETE_FORCE_CHK which forces validation calls down |
| * into this function always. |
| */ |
| |
| from = rcu_dereference(rt->from); |
| |
| if (from && (rt->rt6i_flags & RTF_PCPU || |
| unlikely(!list_empty(&rt->rt6i_uncached)))) |
| dst_ret = rt6_dst_from_check(rt, from, cookie); |
| else |
| dst_ret = rt6_check(rt, from, cookie); |
| |
| rcu_read_unlock(); |
| |
| return dst_ret; |
| } |
| EXPORT_INDIRECT_CALLABLE(ip6_dst_check); |
| |
| static struct dst_entry *ip6_negative_advice(struct dst_entry *dst) |
| { |
| struct rt6_info *rt = (struct rt6_info *) dst; |
| |
| if (rt) { |
| if (rt->rt6i_flags & RTF_CACHE) { |
| rcu_read_lock(); |
| if (rt6_check_expired(rt)) { |
| rt6_remove_exception_rt(rt); |
| dst = NULL; |
| } |
| rcu_read_unlock(); |
| } else { |
| dst_release(dst); |
| dst = NULL; |
| } |
| } |
| return dst; |
| } |
| |
| static void ip6_link_failure(struct sk_buff *skb) |
| { |
| struct rt6_info *rt; |
| |
| icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0); |
| |
| rt = (struct rt6_info *) skb_dst(skb); |
| if (rt) { |
| rcu_read_lock(); |
| if (rt->rt6i_flags & RTF_CACHE) { |
| rt6_remove_exception_rt(rt); |
| } else { |
| struct fib6_info *from; |
| struct fib6_node *fn; |
| |
| from = rcu_dereference(rt->from); |
| if (from) { |
| fn = rcu_dereference(from->fib6_node); |
| if (fn && (rt->rt6i_flags & RTF_DEFAULT)) |
| WRITE_ONCE(fn->fn_sernum, -1); |
| } |
| } |
| rcu_read_unlock(); |
| } |
| } |
| |
| static void rt6_update_expires(struct rt6_info *rt0, int timeout) |
| { |
| if (!(rt0->rt6i_flags & RTF_EXPIRES)) { |
| struct fib6_info *from; |
| |
| rcu_read_lock(); |
| from = rcu_dereference(rt0->from); |
| if (from) |
| rt0->dst.expires = from->expires; |
| rcu_read_unlock(); |
| } |
| |
| dst_set_expires(&rt0->dst, timeout); |
| rt0->rt6i_flags |= RTF_EXPIRES; |
| } |
| |
| static void rt6_do_update_pmtu(struct rt6_info *rt, u32 mtu) |
| { |
| struct net *net = dev_net(rt->dst.dev); |
| |
| dst_metric_set(&rt->dst, RTAX_MTU, mtu); |
| rt->rt6i_flags |= RTF_MODIFIED; |
| rt6_update_expires(rt, net->ipv6.sysctl.ip6_rt_mtu_expires); |
| } |
| |
| static bool rt6_cache_allowed_for_pmtu(const struct rt6_info *rt) |
| { |
| return !(rt->rt6i_flags & RTF_CACHE) && |
| (rt->rt6i_flags & RTF_PCPU || rcu_access_pointer(rt->from)); |
| } |
| |
| static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk, |
| const struct ipv6hdr *iph, u32 mtu, |
| bool confirm_neigh) |
| { |
| const struct in6_addr *daddr, *saddr; |
| struct rt6_info *rt6 = (struct rt6_info *)dst; |
| |
| /* Note: do *NOT* check dst_metric_locked(dst, RTAX_MTU) |
| * IPv6 pmtu discovery isn't optional, so 'mtu lock' cannot disable it. |
| * [see also comment in rt6_mtu_change_route()] |
| */ |
| |
| if (iph) { |
| daddr = &iph->daddr; |
| saddr = &iph->saddr; |
| } else if (sk) { |
| daddr = &sk->sk_v6_daddr; |
| saddr = &inet6_sk(sk)->saddr; |
| } else { |
| daddr = NULL; |
| saddr = NULL; |
| } |
| |
| if (confirm_neigh) |
| dst_confirm_neigh(dst, daddr); |
| |
| if (mtu < IPV6_MIN_MTU) |
| return; |
| if (mtu >= dst_mtu(dst)) |
| return; |
| |
| if (!rt6_cache_allowed_for_pmtu(rt6)) { |
| rt6_do_update_pmtu(rt6, mtu); |
| /* update rt6_ex->stamp for cache */ |
| if (rt6->rt6i_flags & RTF_CACHE) |
| rt6_update_exception_stamp_rt(rt6); |
| } else if (daddr) { |
| struct fib6_result res = {}; |
| struct rt6_info *nrt6; |
| |
| rcu_read_lock(); |
| res.f6i = rcu_dereference(rt6->from); |
| if (!res.f6i) |
| goto out_unlock; |
| |
| res.fib6_flags = res.f6i->fib6_flags; |
| res.fib6_type = res.f6i->fib6_type; |
| |
| if (res.f6i->nh) { |
| struct fib6_nh_match_arg arg = { |
| .dev = dst->dev, |
| .gw = &rt6->rt6i_gateway, |
| }; |
| |
| nexthop_for_each_fib6_nh(res.f6i->nh, |
| fib6_nh_find_match, &arg); |
| |
| /* fib6_info uses a nexthop that does not have fib6_nh |
| * using the dst->dev + gw. Should be impossible. |
| */ |
| if (!arg.match) |
| goto out_unlock; |
| |
| res.nh = arg.match; |
| } else { |
| res.nh = res.f6i->fib6_nh; |
| } |
| |
| nrt6 = ip6_rt_cache_alloc(&res, daddr, saddr); |
| if (nrt6) { |
| rt6_do_update_pmtu(nrt6, mtu); |
| if (rt6_insert_exception(nrt6, &res)) |
| dst_release_immediate(&nrt6->dst); |
| } |
| out_unlock: |
| rcu_read_unlock(); |
| } |
| } |
| |
| static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk, |
| struct sk_buff *skb, u32 mtu, |
| bool confirm_neigh) |
| { |
| __ip6_rt_update_pmtu(dst, sk, skb ? ipv6_hdr(skb) : NULL, mtu, |
| confirm_neigh); |
| } |
| |
| void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu, |
| int oif, u32 mark, kuid_t uid) |
| { |
| const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data; |
| struct dst_entry *dst; |
| struct flowi6 fl6 = { |
| .flowi6_oif = oif, |
| .flowi6_mark = mark ? mark : IP6_REPLY_MARK(net, skb->mark), |
| .daddr = iph->daddr, |
| .saddr = iph->saddr, |
| .flowlabel = ip6_flowinfo(iph), |
| .flowi6_uid = uid, |
| }; |
| |
| dst = ip6_route_output(net, NULL, &fl6); |
| if (!dst->error) |
| __ip6_rt_update_pmtu(dst, NULL, iph, ntohl(mtu), true); |
| dst_release(dst); |
| } |
| EXPORT_SYMBOL_GPL(ip6_update_pmtu); |
| |
| void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu) |
| { |
| int oif = sk->sk_bound_dev_if; |
| struct dst_entry *dst; |
| |
| if (!oif && skb->dev) |
| oif = l3mdev_master_ifindex(skb->dev); |
| |
| ip6_update_pmtu(skb, sock_net(sk), mtu, oif, sk->sk_mark, sk->sk_uid); |
| |
| dst = __sk_dst_get(sk); |
| if (!dst || !dst->obsolete || |
| dst->ops->check(dst, inet6_sk(sk)->dst_cookie)) |
| return; |
| |
| bh_lock_sock(sk); |
| if (!sock_owned_by_user(sk) && !ipv6_addr_v4mapped(&sk->sk_v6_daddr)) |
| ip6_datagram_dst_update(sk, false); |
| bh_unlock_sock(sk); |
| } |
| EXPORT_SYMBOL_GPL(ip6_sk_update_pmtu); |
| |
| void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst, |
| const struct flowi6 *fl6) |
| { |
| #ifdef CONFIG_IPV6_SUBTREES |
| struct ipv6_pinfo *np = inet6_sk(sk); |
| #endif |
| |
| ip6_dst_store(sk, dst, |
| ipv6_addr_equal(&fl6->daddr, &sk->sk_v6_daddr) ? |
| &sk->sk_v6_daddr : NULL, |
| #ifdef CONFIG_IPV6_SUBTREES |
| ipv6_addr_equal(&fl6->saddr, &np->saddr) ? |
| &np->saddr : |
| #endif |
| NULL); |
| } |
| |
| static bool ip6_redirect_nh_match(const struct fib6_result *res, |
|