diff options
Diffstat (limited to '')
| -rw-r--r-- | net/ipv6/route.c | 6637 |
1 files changed, 6637 insertions, 0 deletions
diff --git a/net/ipv6/route.c b/net/ipv6/route.c new file mode 100644 index 000000000..b23e42efb --- /dev/null +++ b/net/ipv6/route.c @@ -0,0 +1,6637 @@ +// 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 +}; + +static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie); +static unsigned int ip6_default_advmss(const struct dst_entry *dst); +static 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 void 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; + __u8 neigh_flags = 0; + + neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway); + if (neigh) + neigh_flags = neigh->flags; + + if (!(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; + } +} + +/* 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; + + 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; + } + 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; + } + 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; + } + break; + } + mhash = flow_hash_from_keys(&hash_keys); + + 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; +} + +static 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; +} + +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, + struct flowi6 *fl6, + const struct in6_addr *gw, + struct rt6_info **ret) +{ + const struct fib6_nh *nh = res->nh; + + if (nh->fib_nh_flags & RTNH_F_DEAD || !nh->fib_nh_gw_family || + fl6->flowi6_oif != nh->fib_nh_dev->ifindex) + return false; + + /* rt_cache's gateway might be different from its 'parent' + * in the case of an ip redirect. + * So we keep searching in the exception table if the gateway + * is different. + */ + if (!ipv6_addr_equal(gw, &nh->fib_nh_gw6)) { + struct rt6_info *rt_cache; + + rt_cache = rt6_find_cached_rt(res, &fl6->daddr, &fl6->saddr); + if (rt_cache && + ipv6_addr_equal(gw, &rt_cache->rt6i_gateway)) { + *ret = rt_cache; + return true; + } + return false; + } + return true; +} + +struct fib6_nh_rd_arg { + struct fib6_result *res; + struct flowi6 *fl6; + const struct in6_addr *gw; + struct rt6_info **ret; +}; + +static int fib6_nh_redirect_match(struct fib6_nh *nh, void *_arg) +{ + struct fib6_nh_rd_arg *arg = _arg; + + arg->res->nh = nh; + return ip6_redirect_nh_match(arg->res, arg->fl6, arg->gw, arg->ret); +} + +/* Handle redirects */ +struct ip6rd_flowi { + struct flowi6 fl6; + struct in6_addr gateway; +}; + +INDIRECT_CALLABLE_SCOPE struct rt6_info *__ip6_route_redirect(struct net *net, + struct fib6_table *table, + struct flowi6 *fl6, + const struct sk_buff *skb, + int flags) +{ + struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl6; + struct rt6_info *ret = NULL; + struct fib6_result res = {}; + struct fib6_nh_rd_arg arg = { + .res = &res, + .fl6 = fl6, + .gw = &rdfl->gateway, + .ret = &ret + }; + struct fib6_info *rt; + struct fib6_node *fn; + + /* l3mdev_update_flow overrides oif if the device is enslaved; in + * this case we must match on the real ingress device, so reset it + */ + if (fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF) + fl6->flowi6_oif = skb->dev->ifindex; + + /* Get the "current" route for this destination and + * check if the redirect has come from appropriate router. + * + * RFC 4861 specifies that redirects should only be + * accepted if they come from the nexthop to the target. + * Due to the way the routes are chosen, this notion + * is a bit fuzzy and one might need to check all possible + * routes. + */ + + rcu_read_lock(); + fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr); +restart: + for_each_fib6_node_rt_rcu(fn) { + res.f6i = rt; + if (fib6_check_expired(rt)) + continue; + if (rt->fib6_flags & RTF_REJECT) + break; + if (unlikely(rt->nh)) { + if (nexthop_is_blackhole(rt->nh)) + continue; + /* on match, res->nh is filled in and potentially ret */ + if (nexthop_for_each_fib6_nh(rt->nh, + fib6_nh_redirect_match, + &arg)) + goto out; + } else { + res.nh = rt->fib6_nh; + if (ip6_redirect_nh_match(&res, fl6, &rdfl->gateway, + &ret)) + goto out; + } + } + + if (!rt) + rt = net->ipv6.fib6_null_entry; + else if (rt->fib6_flags & RTF_REJECT) { + ret = net->ipv6.ip6_null_entry; + goto out; + } + + if (rt == net->ipv6.fib6_null_entry) { + fn = fib6_backtrack(fn, &fl6->saddr); + if (fn) + goto restart; + } + + res.f6i = rt; + res.nh = rt->fib6_nh; +out: + if (ret) { + ip6_hold_safe(net, &ret); + } else { + res.fib6_flags = res.f6i->fib6_flags; + res.fib6_type = res.f6i->fib6_type; + ret = ip6_create_rt_rcu(&res); + } + + rcu_read_unlock(); + + trace_fib6_table_lookup(net, &res, table, fl6); + return ret; +}; + +static struct dst_entry *ip6_route_redirect(struct net *net, + const struct flowi6 *fl6, + const struct sk_buff *skb, + const struct in6_addr *gateway) +{ + int flags = RT6_LOOKUP_F_HAS_SADDR; + struct ip6rd_flowi rdfl; + + rdfl.fl6 = *fl6; + rdfl.gateway = *gateway; + + return fib6_rule_lookup(net, &rdfl.fl6, skb, + flags, __ip6_route_redirect); +} + +void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark, + kuid_t uid) +{ + const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data; + struct dst_entry *dst; + struct flowi6 fl6 = { + .flowi6_iif = LOOPBACK_IFINDEX, + .flowi6_oif = oif, + .flowi6_mark = mark, + .daddr = iph->daddr, + .saddr = iph->saddr, + .flowlabel = ip6_flowinfo(iph), + .flowi6_uid = uid, + }; + + dst = ip6_route_redirect(net, &fl6, skb, &ipv6_hdr(skb)->saddr); + rt6_do_redirect(dst, NULL, skb); + dst_release(dst); +} +EXPORT_SYMBOL_GPL(ip6_redirect); + +void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif) +{ + const struct ipv6hdr *iph = ipv6_hdr(skb); + const struct rd_msg *msg = (struct rd_msg *)icmp6_hdr(skb); + struct dst_entry *dst; + struct flowi6 fl6 = { + .flowi6_iif = LOOPBACK_IFINDEX, + .flowi6_oif = oif, + .daddr = msg->dest, + .saddr = iph->daddr, + .flowi6_uid = sock_net_uid(net, NULL), + }; + + dst = ip6_route_redirect(net, &fl6, skb, &iph->saddr); + rt6_do_redirect(dst, NULL, skb); + dst_release(dst); +} + +void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk) +{ + ip6_redirect(skb, sock_net(sk), sk->sk_bound_dev_if, sk->sk_mark, + sk->sk_uid); +} +EXPORT_SYMBOL_GPL(ip6_sk_redirect); + +static unsigned int ip6_default_advmss(const struct dst_entry *dst) +{ + struct net_device *dev = dst->dev; + unsigned int mtu = dst_mtu(dst); + struct net *net = dev_net(dev); + + mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr); + + if (mtu < net->ipv6.sysctl.ip6_rt_min_advmss) + mtu = net->ipv6.sysctl.ip6_rt_min_advmss; + + /* + * Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and + * corresponding MSS is IPV6_MAXPLEN - tcp_header_size. + * IPV6_MAXPLEN is also valid and means: "any MSS, + * rely only on pmtu discovery" + */ + if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr)) + mtu = IPV6_MAXPLEN; + return mtu; +} + +static unsigned int ip6_mtu(const struct dst_entry *dst) +{ + struct inet6_dev *idev; + unsigned int mtu; + + mtu = dst_metric_raw(dst, RTAX_MTU); + if (mtu) + goto out; + + mtu = IPV6_MIN_MTU; + + rcu_read_lock(); + idev = __in6_dev_get(dst->dev); + if (idev) + mtu = idev->cnf.mtu6; + rcu_read_unlock(); + +out: + mtu = min_t(unsigned int, mtu, IP6_MAX_MTU); + + return mtu - lwtunnel_headroom(dst->lwtstate, mtu); +} + +/* MTU selection: + * 1. mtu on route is locked - use it + * 2. mtu from nexthop exception + * 3. mtu from egress device + * + * based on ip6_dst_mtu_forward and exception logic of + * rt6_find_cached_rt; called with rcu_read_lock + */ +u32 ip6_mtu_from_fib6(const struct fib6_result *res, + const struct in6_addr *daddr, + const struct in6_addr *saddr) +{ + const struct fib6_nh *nh = res->nh; + struct fib6_info *f6i = res->f6i; + struct inet6_dev *idev; + struct rt6_info *rt; + u32 mtu = 0; + + if (unlikely(fib6_metric_locked(f6i, RTAX_MTU))) { + mtu = f6i->fib6_pmtu; + if (mtu) + goto out; + } + + rt = rt6_find_cached_rt(res, daddr, saddr); + if (unlikely(rt)) { + mtu = dst_metric_raw(&rt->dst, RTAX_MTU); + } else { + struct net_device *dev = nh->fib_nh_dev; + + mtu = IPV6_MIN_MTU; + idev = __in6_dev_get(dev); + if (idev && idev->cnf.mtu6 > mtu) + mtu = idev->cnf.mtu6; + } + + mtu = min_t(unsigned int, mtu, IP6_MAX_MTU); +out: + return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu); +} + +struct dst_entry *icmp6_dst_alloc(struct net_device *dev, + struct flowi6 *fl6) +{ + struct dst_entry *dst; + struct rt6_info *rt; + struct inet6_dev *idev = in6_dev_get(dev); + struct net *net = dev_net(dev); + + if (unlikely(!idev)) + return ERR_PTR(-ENODEV); + + rt = ip6_dst_alloc(net, dev, 0); + if (unlikely(!rt)) { + in6_dev_put(idev); + dst = ERR_PTR(-ENOMEM); + goto out; + } + + rt->dst.input = ip6_input; + rt->dst.output = ip6_output; + rt->rt6i_gateway = fl6->daddr; + rt->rt6i_dst.addr = fl6->daddr; + rt->rt6i_dst.plen = 128; + rt->rt6i_idev = idev; + dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 0); + + /* Add this dst into uncached_list so that rt6_disable_ip() can + * do proper release of the net_device + */ + rt6_uncached_list_add(rt); + atomic_inc(&net->ipv6.rt6_stats->fib_rt_uncache); + + dst = xfrm_lookup(net, &rt->dst, flowi6_to_flowi(fl6), NULL, 0); + +out: + return dst; +} + +static void ip6_dst_gc(struct dst_ops *ops) +{ + struct net *net = container_of(ops, struct net, ipv6.ip6_dst_ops); + int rt_min_interval = net->ipv6.sysctl.ip6_rt_gc_min_interval; + int rt_elasticity = net->ipv6.sysctl.ip6_rt_gc_elasticity; + int rt_gc_timeout = net->ipv6.sysctl.ip6_rt_gc_timeout; + unsigned long rt_last_gc = net->ipv6.ip6_rt_last_gc; + unsigned int val; + int entries; + + entries = dst_entries_get_fast(ops); + if (entries > ops->gc_thresh) + entries = dst_entries_get_slow(ops); + + if (time_after(rt_last_gc + rt_min_interval, jiffies)) + goto out; + + fib6_run_gc(atomic_inc_return(&net->ipv6.ip6_rt_gc_expire), net, true); + entries = dst_entries_get_slow(ops); + if (entries < ops->gc_thresh) + atomic_set(&net->ipv6.ip6_rt_gc_expire, rt_gc_timeout >> 1); +out: + val = atomic_read(&net->ipv6.ip6_rt_gc_expire); + atomic_set(&net->ipv6.ip6_rt_gc_expire, val - (val >> rt_elasticity)); +} + +static int ip6_nh_lookup_table(struct net *net, struct fib6_config *cfg, + const struct in6_addr *gw_addr, u32 tbid, + int flags, struct fib6_result *res) +{ + struct flowi6 fl6 = { + .flowi6_oif = cfg->fc_ifindex, + .daddr = *gw_addr, + .saddr = cfg->fc_prefsrc, + }; + struct fib6_table *table; + int err; + + table = fib6_get_table(net, tbid); + if (!table) + return -EINVAL; + + if (!ipv6_addr_any(&cfg->fc_prefsrc)) + flags |= RT6_LOOKUP_F_HAS_SADDR; + + flags |= RT6_LOOKUP_F_IGNORE_LINKSTATE; + + err = fib6_table_lookup(net, table, cfg->fc_ifindex, &fl6, res, flags); + if (!err && res->f6i != net->ipv6.fib6_null_entry) + fib6_select_path(net, res, &fl6, cfg->fc_ifindex, + cfg->fc_ifindex != 0, NULL, flags); + + return err; +} + +static int ip6_route_check_nh_onlink(struct net *net, + struct fib6_config *cfg, + const struct net_device *dev, + struct netlink_ext_ack *extack) +{ + u32 tbid = l3mdev_fib_table_rcu(dev) ? : RT_TABLE_MAIN; + const struct in6_addr *gw_addr = &cfg->fc_gateway; + struct fib6_result res = {}; + int err; + + err = ip6_nh_lookup_table(net, cfg, gw_addr, tbid, 0, &res); + if (!err && !(res.fib6_flags & RTF_REJECT) && + /* ignore match if it is the default route */ + !ipv6_addr_any(&res.f6i->fib6_dst.addr) && + (res.fib6_type != RTN_UNICAST || dev != res.nh->fib_nh_dev)) { + NL_SET_ERR_MSG(extack, + "Nexthop has invalid gateway or device mismatch"); + err = -EINVAL; + } + + return err; +} + +static int ip6_route_check_nh(struct net *net, + struct fib6_config *cfg, + struct net_device **_dev, + struct inet6_dev **idev) +{ + const struct in6_addr *gw_addr = &cfg->fc_gateway; + struct net_device *dev = _dev ? *_dev : NULL; + int flags = RT6_LOOKUP_F_IFACE; + struct fib6_result res = {}; + int err = -EHOSTUNREACH; + + if (cfg->fc_table) { + err = ip6_nh_lookup_table(net, cfg, gw_addr, + cfg->fc_table, flags, &res); + /* gw_addr can not require a gateway or resolve to a reject + * route. If a device is given, it must match the result. + */ + if (err || res.fib6_flags & RTF_REJECT || + res.nh->fib_nh_gw_family || + (dev && dev != res.nh->fib_nh_dev)) + err = -EHOSTUNREACH; + } + + if (err < 0) { + struct flowi6 fl6 = { + .flowi6_oif = cfg->fc_ifindex, + .daddr = *gw_addr, + }; + + err = fib6_lookup(net, cfg->fc_ifindex, &fl6, &res, flags); + if (err || res.fib6_flags & RTF_REJECT || + res.nh->fib_nh_gw_family) + err = -EHOSTUNREACH; + + if (err) + return err; + + fib6_select_path(net, &res, &fl6, cfg->fc_ifindex, + cfg->fc_ifindex != 0, NULL, flags); + } + + err = 0; + if (dev) { + if (dev != res.nh->fib_nh_dev) + err = -EHOSTUNREACH; + } else { + *_dev = dev = res.nh->fib_nh_dev; + dev_hold(dev); + *idev = in6_dev_get(dev); + } + + return err; +} + +static int ip6_validate_gw(struct net *net, struct fib6_config *cfg, + struct net_device **_dev, struct inet6_dev **idev, + struct netlink_ext_ack *extack) +{ + const struct in6_addr *gw_addr = &cfg->fc_gateway; + int gwa_type = ipv6_addr_type(gw_addr); + bool skip_dev = gwa_type & IPV6_ADDR_LINKLOCAL ? false : true; + const struct net_device *dev = *_dev; + bool need_addr_check = !dev; + int err = -EINVAL; + + /* if gw_addr is local we will fail to detect this in case + * address is still TENTATIVE (DAD in progress). rt6_lookup() + * will return already-added prefix route via interface that + * prefix route was assigned to, which might be non-loopback. + */ + if (dev && + ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) { + NL_SET_ERR_MSG(extack, "Gateway can not be a local address"); + goto out; + } + + if (gwa_type != (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST)) { + /* IPv6 strictly inhibits using not link-local + * addresses as nexthop address. + * Otherwise, router will not able to send redirects. + * It is very good, but in some (rare!) circumstances + * (SIT, PtP, NBMA NOARP links) it is handy to allow + * some exceptions. --ANK + * We allow IPv4-mapped nexthops to support RFC4798-type + * addressing + */ + if (!(gwa_type & (IPV6_ADDR_UNICAST | IPV6_ADDR_MAPPED))) { + NL_SET_ERR_MSG(extack, "Invalid gateway address"); + goto out; + } + + rcu_read_lock(); + + if (cfg->fc_flags & RTNH_F_ONLINK) + err = ip6_route_check_nh_onlink(net, cfg, dev, extack); + else + err = ip6_route_check_nh(net, cfg, _dev, idev); + + rcu_read_unlock(); + + if (err) + goto out; + } + + /* reload in case device was changed */ + dev = *_dev; + + err = -EINVAL; + if (!dev) { + NL_SET_ERR_MSG(extack, "Egress device not specified"); + goto out; + } else if (dev->flags & IFF_LOOPBACK) { + NL_SET_ERR_MSG(extack, + "Egress device can not be loopback device for this route"); + goto out; + } + + /* if we did not check gw_addr above, do so now that the + * egress device has been resolved. + */ + if (need_addr_check && + ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) { + NL_SET_ERR_MSG(extack, "Gateway can not be a local address"); + goto out; + } + + err = 0; +out: + return err; +} + +static bool fib6_is_reject(u32 flags, struct net_device *dev, int addr_type) +{ + if ((flags & RTF_REJECT) || + (dev && (dev->flags & IFF_LOOPBACK) && + !(addr_type & IPV6_ADDR_LOOPBACK) && + !(flags & (RTF_ANYCAST | RTF_LOCAL)))) + return true; + + return false; +} + +int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh, + struct fib6_config *cfg, gfp_t gfp_flags, + struct netlink_ext_ack *extack) +{ + struct net_device *dev = NULL; + struct inet6_dev *idev = NULL; + int addr_type; + int err; + + fib6_nh->fib_nh_family = AF_INET6; +#ifdef CONFIG_IPV6_ROUTER_PREF + fib6_nh->last_probe = jiffies; +#endif + if (cfg->fc_is_fdb) { + fib6_nh->fib_nh_gw6 = cfg->fc_gateway; + fib6_nh->fib_nh_gw_family = AF_INET6; + return 0; + } + + err = -ENODEV; + if (cfg->fc_ifindex) { + dev = dev_get_by_index(net, cfg->fc_ifindex); + if (!dev) + goto out; + idev = in6_dev_get(dev); + if (!idev) + goto out; + } + + if (cfg->fc_flags & RTNH_F_ONLINK) { + if (!dev) { + NL_SET_ERR_MSG(extack, + "Nexthop device required for onlink"); + goto out; + } + + if (!(dev->flags & IFF_UP)) { + NL_SET_ERR_MSG(extack, "Nexthop device is not up"); + err = -ENETDOWN; + goto out; + } + + fib6_nh->fib_nh_flags |= RTNH_F_ONLINK; + } + + fib6_nh->fib_nh_weight = 1; + + /* We cannot add true routes via loopback here, + * they would result in kernel looping; promote them to reject routes + */ + addr_type = ipv6_addr_type(&cfg->fc_dst); + if (fib6_is_reject(cfg->fc_flags, dev, addr_type)) { + /* hold loopback dev/idev if we haven't done so. */ + if (dev != net->loopback_dev) { + if (dev) { + dev_put(dev); + in6_dev_put(idev); + } + dev = net->loopback_dev; + dev_hold(dev); + idev = in6_dev_get(dev); + if (!idev) { + err = -ENODEV; + goto out; + } + } + goto pcpu_alloc; + } + + if (cfg->fc_flags & RTF_GATEWAY) { + err = ip6_validate_gw(net, cfg, &dev, &idev, extack); + if (err) + goto out; + + fib6_nh->fib_nh_gw6 = cfg->fc_gateway; + fib6_nh->fib_nh_gw_family = AF_INET6; + } + + err = -ENODEV; + if (!dev) + goto out; + + if (idev->cnf.disable_ipv6) { + NL_SET_ERR_MSG(extack, "IPv6 is disabled on nexthop device"); + err = -EACCES; + goto out; + } + + if (!(dev->flags & IFF_UP) && !cfg->fc_ignore_dev_down) { + NL_SET_ERR_MSG(extack, "Nexthop device is not up"); + err = -ENETDOWN; + goto out; + } + + if (!(cfg->fc_flags & (RTF_LOCAL | RTF_ANYCAST)) && + !netif_carrier_ok(dev)) + fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN; + + err = fib_nh_common_init(net, &fib6_nh->nh_common, cfg->fc_encap, + cfg->fc_encap_type, cfg, gfp_flags, extack); + if (err) + goto out; + +pcpu_alloc: + fib6_nh->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, gfp_flags); + if (!fib6_nh->rt6i_pcpu) { + err = -ENOMEM; + goto out; + } + + fib6_nh->fib_nh_dev = dev; + fib6_nh->fib_nh_oif = dev->ifindex; + err = 0; +out: + if (idev) + in6_dev_put(idev); + + if (err) { + lwtstate_put(fib6_nh->fib_nh_lws); + fib6_nh->fib_nh_lws = NULL; + if (dev) + dev_put(dev); + } + + return err; +} + +void fib6_nh_release(struct fib6_nh *fib6_nh) +{ + struct rt6_exception_bucket *bucket; + + rcu_read_lock(); + + fib6_nh_flush_exceptions(fib6_nh, NULL); + bucket = fib6_nh_get_excptn_bucket(fib6_nh, NULL); + if (bucket) { + rcu_assign_pointer(fib6_nh->rt6i_exception_bucket, NULL); + kfree(bucket); + } + + rcu_read_unlock(); + + if (fib6_nh->rt6i_pcpu) { + int cpu; + + for_each_possible_cpu(cpu) { + struct rt6_info **ppcpu_rt; + struct rt6_info *pcpu_rt; + + ppcpu_rt = per_cpu_ptr(fib6_nh->rt6i_pcpu, cpu); + pcpu_rt = *ppcpu_rt; + if (pcpu_rt) { + dst_dev_put(&pcpu_rt->dst); + dst_release(&pcpu_rt->dst); + *ppcpu_rt = NULL; + } + } + + free_percpu(fib6_nh->rt6i_pcpu); + } + + fib_nh_common_release(&fib6_nh->nh_common); +} + +void fib6_nh_release_dsts(struct fib6_nh *fib6_nh) +{ + int cpu; + + if (!fib6_nh->rt6i_pcpu) + return; + + for_each_possible_cpu(cpu) { + struct rt6_info *pcpu_rt, **ppcpu_rt; + + ppcpu_rt = per_cpu_ptr(fib6_nh->rt6i_pcpu, cpu); + pcpu_rt = xchg(ppcpu_rt, NULL); + if (pcpu_rt) { + dst_dev_put(&pcpu_rt->dst); + dst_release(&pcpu_rt->dst); + } + } +} + +static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg, + gfp_t gfp_flags, + struct netlink_ext_ack *extack) +{ + struct net *net = cfg->fc_nlinfo.nl_net; + struct fib6_info *rt = NULL; + struct nexthop *nh = NULL; + struct fib6_table *table; + struct fib6_nh *fib6_nh; + int err = -EINVAL; + int addr_type; + + /* RTF_PCPU is an internal flag; can not be set by userspace */ + if (cfg->fc_flags & RTF_PCPU) { + NL_SET_ERR_MSG(extack, "Userspace can not set RTF_PCPU"); + goto out; + } + + /* RTF_CACHE is an internal flag; can not be set by userspace */ + if (cfg->fc_flags & RTF_CACHE) { + NL_SET_ERR_MSG(extack, "Userspace can not set RTF_CACHE"); + goto out; + } + + if (cfg->fc_type > RTN_MAX) { + NL_SET_ERR_MSG(extack, "Invalid route type"); + goto out; + } + + if (cfg->fc_dst_len > 128) { + NL_SET_ERR_MSG(extack, "Invalid prefix length"); + goto out; + } + if (cfg->fc_src_len > 128) { + NL_SET_ERR_MSG(extack, "Invalid source address length"); + goto out; + } +#ifndef CONFIG_IPV6_SUBTREES + if (cfg->fc_src_len) { + NL_SET_ERR_MSG(extack, + "Specifying source address requires IPV6_SUBTREES to be enabled"); + goto out; + } +#endif + if (cfg->fc_nh_id) { + nh = nexthop_find_by_id(net, cfg->fc_nh_id); + if (!nh) { + NL_SET_ERR_MSG(extack, "Nexthop id does not exist"); + goto out; + } + err = fib6_check_nexthop(nh, cfg, extack); + if (err) + goto out; + } + + err = -ENOBUFS; + if (cfg->fc_nlinfo.nlh && + !(cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_CREATE)) { + table = fib6_get_table(net, cfg->fc_table); + if (!table) { + pr_warn("NLM_F_CREATE should be specified when creating new route\n"); + table = fib6_new_table(net, cfg->fc_table); + } + } else { + table = fib6_new_table(net, cfg->fc_table); + } + + if (!table) + goto out; + + err = -ENOMEM; + rt = fib6_info_alloc(gfp_flags, !nh); + if (!rt) + goto out; + + rt->fib6_metrics = ip_fib_metrics_init(net, cfg->fc_mx, cfg->fc_mx_len, + extack); + if (IS_ERR(rt->fib6_metrics)) { + err = PTR_ERR(rt->fib6_metrics); + /* Do not leave garbage there. */ + rt->fib6_metrics = (struct dst_metrics *)&dst_default_metrics; + goto out_free; + } + + if (cfg->fc_flags & RTF_ADDRCONF) + rt->dst_nocount = true; + + if (cfg->fc_flags & RTF_EXPIRES) + fib6_set_expires(rt, jiffies + + clock_t_to_jiffies(cfg->fc_expires)); + else + fib6_clean_expires(rt); + + if (cfg->fc_protocol == RTPROT_UNSPEC) + cfg->fc_protocol = RTPROT_BOOT; + rt->fib6_protocol = cfg->fc_protocol; + + rt->fib6_table = table; + rt->fib6_metric = cfg->fc_metric; + rt->fib6_type = cfg->fc_type ? : RTN_UNICAST; + rt->fib6_flags = cfg->fc_flags & ~RTF_GATEWAY; + + ipv6_addr_prefix(&rt->fib6_dst.addr, &cfg->fc_dst, cfg->fc_dst_len); + rt->fib6_dst.plen = cfg->fc_dst_len; + +#ifdef CONFIG_IPV6_SUBTREES + ipv6_addr_prefix(&rt->fib6_src.addr, &cfg->fc_src, cfg->fc_src_len); + rt->fib6_src.plen = cfg->fc_src_len; +#endif + if (nh) { + if (rt->fib6_src.plen) { + NL_SET_ERR_MSG(extack, "Nexthops can not be used with source routing"); + goto out_free; + } + if (!nexthop_get(nh)) { + NL_SET_ERR_MSG(extack, "Nexthop has been deleted"); + goto out_free; + } + rt->nh = nh; + fib6_nh = nexthop_fib6_nh(rt->nh); + } else { + err = fib6_nh_init(net, rt->fib6_nh, cfg, gfp_flags, extack); + if (err) + goto out; + + fib6_nh = rt->fib6_nh; + + /* We cannot add true routes via loopback here, they would + * result in kernel looping; promote them to reject routes + */ + addr_type = ipv6_addr_type(&cfg->fc_dst); + if (fib6_is_reject(cfg->fc_flags, rt->fib6_nh->fib_nh_dev, + addr_type)) + rt->fib6_flags = RTF_REJECT | RTF_NONEXTHOP; + } + + if (!ipv6_addr_any(&cfg->fc_prefsrc)) { + struct net_device *dev = fib6_nh->fib_nh_dev; + + if (!ipv6_chk_addr(net, &cfg->fc_prefsrc, dev, 0)) { + NL_SET_ERR_MSG(extack, "Invalid source address"); + err = -EINVAL; + goto out; + } + rt->fib6_prefsrc.addr = cfg->fc_prefsrc; + rt->fib6_prefsrc.plen = 128; + } else + rt->fib6_prefsrc.plen = 0; + + return rt; +out: + fib6_info_release(rt); + return ERR_PTR(err); +out_free: + ip_fib_metrics_put(rt->fib6_metrics); + kfree(rt); + return ERR_PTR(err); +} + +int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags, + struct netlink_ext_ack *extack) +{ + struct fib6_info *rt; + int err; + + rt = ip6_route_info_create(cfg, gfp_flags, extack); + if (IS_ERR(rt)) + return PTR_ERR(rt); + + err = __ip6_ins_rt(rt, &cfg->fc_nlinfo, extack); + fib6_info_release(rt); + + return err; +} + +static int __ip6_del_rt(struct fib6_info *rt, struct nl_info *info) +{ + struct net *net = info->nl_net; + struct fib6_table *table; + int err; + + if (rt == net->ipv6.fib6_null_entry) { + err = -ENOENT; + goto out; + } + + table = rt->fib6_table; + spin_lock_bh(&table->tb6_lock); + err = fib6_del(rt, info); + spin_unlock_bh(&table->tb6_lock); + +out: + fib6_info_release(rt); + return err; +} + +int ip6_del_rt(struct net *net, struct fib6_info *rt, bool skip_notify) +{ + struct nl_info info = { + .nl_net = net, + .skip_notify = skip_notify + }; + + return __ip6_del_rt(rt, &info); +} + +static int __ip6_del_rt_siblings(struct fib6_info *rt, struct fib6_config *cfg) +{ + struct nl_info *info = &cfg->fc_nlinfo; + struct net *net = info->nl_net; + struct sk_buff *skb = NULL; + struct fib6_table *table; + int err = -ENOENT; + + if (rt == net->ipv6.fib6_null_entry) + goto out_put; + table = rt->fib6_table; + spin_lock_bh(&table->tb6_lock); + + if (rt->fib6_nsiblings && cfg->fc_delete_all_nh) { + struct fib6_info *sibling, *next_sibling; + struct fib6_node *fn; + + /* prefer to send a single notification with all hops */ + skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any()); + if (skb) { + u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0; + + if (rt6_fill_node(net, skb, rt, NULL, + NULL, NULL, 0, RTM_DELROUTE, + info->portid, seq, 0) < 0) { + kfree_skb(skb); + skb = NULL; + } else + info->skip_notify = 1; + } + + /* 'rt' points to the first sibling route. If it is not the + * leaf, then we do not need to send a notification. Otherwise, + * we need to check if the last sibling has a next route or not + * and emit a replace or delete notification, respectively. + */ + info->skip_notify_kernel = 1; + fn = rcu_dereference_protected(rt->fib6_node, + lockdep_is_held(&table->tb6_lock)); + if (rcu_access_pointer(fn->leaf) == rt) { + struct fib6_info *last_sibling, *replace_rt; + + last_sibling = list_last_entry(&rt->fib6_siblings, + struct fib6_info, + fib6_siblings); + replace_rt = rcu_dereference_protected( + last_sibling->fib6_next, + lockdep_is_held(&table->tb6_lock)); + if (replace_rt) + call_fib6_entry_notifiers_replace(net, + replace_rt); + else + call_fib6_multipath_entry_notifiers(net, + FIB_EVENT_ENTRY_DEL, + rt, rt->fib6_nsiblings, + NULL); + } + list_for_each_entry_safe(sibling, next_sibling, + &rt->fib6_siblings, + fib6_siblings) { + err = fib6_del(sibling, info); + if (err) + goto out_unlock; + } + } + + err = fib6_del(rt, info); +out_unlock: + spin_unlock_bh(&table->tb6_lock); +out_put: + fib6_info_release(rt); + + if (skb) { + rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE, + info->nlh, gfp_any()); + } + return err; +} + +static int __ip6_del_cached_rt(struct rt6_info *rt, struct fib6_config *cfg) +{ + int rc = -ESRCH; + + if (cfg->fc_ifindex && rt->dst.dev->ifindex != cfg->fc_ifindex) + goto out; + + if (cfg->fc_flags & RTF_GATEWAY && + !ipv6_addr_equal(&cfg->fc_gateway, &rt->rt6i_gateway)) + goto out; + + rc = rt6_remove_exception_rt(rt); +out: + return rc; +} + +static int ip6_del_cached_rt(struct fib6_config *cfg, struct fib6_info *rt, + struct fib6_nh *nh) +{ + struct fib6_result res = { + .f6i = rt, + .nh = nh, + }; + struct rt6_info *rt_cache; + + rt_cache = rt6_find_cached_rt(&res, &cfg->fc_dst, &cfg->fc_src); + if (rt_cache) + return __ip6_del_cached_rt(rt_cache, cfg); + + return 0; +} + +struct fib6_nh_del_cached_rt_arg { + struct fib6_config *cfg; + struct fib6_info *f6i; +}; + +static int fib6_nh_del_cached_rt(struct fib6_nh *nh, void *_arg) +{ + struct fib6_nh_del_cached_rt_arg *arg = _arg; + int rc; + + rc = ip6_del_cached_rt(arg->cfg, arg->f6i, nh); + return rc != -ESRCH ? rc : 0; +} + +static int ip6_del_cached_rt_nh(struct fib6_config *cfg, struct fib6_info *f6i) +{ + struct fib6_nh_del_cached_rt_arg arg = { + .cfg = cfg, + .f6i = f6i + }; + + return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_del_cached_rt, &arg); +} + +static int ip6_route_del(struct fib6_config *cfg, + struct netlink_ext_ack *extack) +{ + struct fib6_table *table; + struct fib6_info *rt; + struct fib6_node *fn; + int err = -ESRCH; + + table = fib6_get_table(cfg->fc_nlinfo.nl_net, cfg->fc_table); + if (!table) { + NL_SET_ERR_MSG(extack, "FIB table does not exist"); + return err; + } + + rcu_read_lock(); + + fn = fib6_locate(&table->tb6_root, + &cfg->fc_dst, cfg->fc_dst_len, + &cfg->fc_src, cfg->fc_src_len, + !(cfg->fc_flags & RTF_CACHE)); + + if (fn) { + for_each_fib6_node_rt_rcu(fn) { + struct fib6_nh *nh; + + if (rt->nh && cfg->fc_nh_id && + rt->nh->id != cfg->fc_nh_id) + continue; + + if (cfg->fc_flags & RTF_CACHE) { + int rc = 0; + + if (rt->nh) { + rc = ip6_del_cached_rt_nh(cfg, rt); + } else if (cfg->fc_nh_id) { + continue; + } else { + nh = rt->fib6_nh; + rc = ip6_del_cached_rt(cfg, rt, nh); + } + if (rc != -ESRCH) { + rcu_read_unlock(); + return rc; + } + continue; + } + + if (cfg->fc_metric && cfg->fc_metric != rt->fib6_metric) + continue; + if (cfg->fc_protocol && + cfg->fc_protocol != rt->fib6_protocol) + continue; + + if (rt->nh) { + if (!fib6_info_hold_safe(rt)) + continue; + rcu_read_unlock(); + + return __ip6_del_rt(rt, &cfg->fc_nlinfo); + } + if (cfg->fc_nh_id) + continue; + + nh = rt->fib6_nh; + if (cfg->fc_ifindex && + (!nh->fib_nh_dev || + nh->fib_nh_dev->ifindex != cfg->fc_ifindex)) + continue; + if (cfg->fc_flags & RTF_GATEWAY && + !ipv6_addr_equal(&cfg->fc_gateway, &nh->fib_nh_gw6)) + continue; + if (!fib6_info_hold_safe(rt)) + continue; + rcu_read_unlock(); + + /* if gateway was specified only delete the one hop */ + if (cfg->fc_flags & RTF_GATEWAY) + return __ip6_del_rt(rt, &cfg->fc_nlinfo); + + return __ip6_del_rt_siblings(rt, cfg); + } + } + rcu_read_unlock(); + + return err; +} + +static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb) +{ + struct netevent_redirect netevent; + struct rt6_info *rt, *nrt = NULL; + struct fib6_result res = {}; + struct ndisc_options ndopts; + struct inet6_dev *in6_dev; + struct neighbour *neigh; + struct rd_msg *msg; + int optlen, on_link; + u8 *lladdr; + + optlen = skb_tail_pointer(skb) - skb_transport_header(skb); + optlen -= sizeof(*msg); + + if (optlen < 0) { + net_dbg_ratelimited("rt6_do_redirect: packet too short\n"); + return; + } + + msg = (struct rd_msg *)icmp6_hdr(skb); + + if (ipv6_addr_is_multicast(&msg->dest)) { + net_dbg_ratelimited("rt6_do_redirect: destination address is multicast\n"); + return; + } + + on_link = 0; + if (ipv6_addr_equal(&msg->dest, &msg->target)) { + on_link = 1; + } else if (ipv6_addr_type(&msg->target) != + (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) { + net_dbg_ratelimited("rt6_do_redirect: target address is not link-local unicast\n"); + return; + } + + in6_dev = __in6_dev_get(skb->dev); + if (!in6_dev) + return; + if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects) + return; + + /* RFC2461 8.1: + * The IP source address of the Redirect MUST be the same as the current + * first-hop router for the specified ICMP Destination Address. + */ + + if (!ndisc_parse_options(skb->dev, msg->opt, optlen, &ndopts)) { + net_dbg_ratelimited("rt6_redirect: invalid ND options\n"); + return; + } + + lladdr = NULL; + if (ndopts.nd_opts_tgt_lladdr) { + lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr, + skb->dev); + if (!lladdr) { + net_dbg_ratelimited("rt6_redirect: invalid link-layer address length\n"); + return; + } + } + + rt = (struct rt6_info *) dst; + if (rt->rt6i_flags & RTF_REJECT) { + net_dbg_ratelimited("rt6_redirect: source isn't a valid nexthop for redirect target\n"); + return; + } + + /* Redirect received -> path was valid. + * Look, redirects are sent only in response to data packets, + * so that this nexthop apparently is reachable. --ANK + */ + dst_confirm_neigh(&rt->dst, &ipv6_hdr(skb)->saddr); + + neigh = __neigh_lookup(&nd_tbl, &msg->target, skb->dev, 1); + if (!neigh) + return; + + /* + * We have finally decided to accept it. + */ + + ndisc_update(skb->dev, neigh, lladdr, NUD_STALE, + NEIGH_UPDATE_F_WEAK_OVERRIDE| + NEIGH_UPDATE_F_OVERRIDE| + (on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER| + NEIGH_UPDATE_F_ISROUTER)), + NDISC_REDIRECT, &ndopts); + + rcu_read_lock(); + res.f6i = rcu_dereference(rt->from); + if (!res.f6i) + goto out; + + if (res.f6i->nh) { + struct fib6_nh_match_arg arg = { + .dev = dst->dev, + .gw = &rt->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. Should be impossible + */ + if (!arg.match) + goto out; + res.nh = arg.match; + } else { + res.nh = res.f6i->fib6_nh; + } + + res.fib6_flags = res.f6i->fib6_flags; + res.fib6_type = res.f6i->fib6_type; + nrt = ip6_rt_cache_alloc(&res, &msg->dest, NULL); + if (!nrt) + goto out; + + nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE; + if (on_link) + nrt->rt6i_flags &= ~RTF_GATEWAY; + + nrt->rt6i_gateway = *(struct in6_addr *)neigh->primary_key; + + /* rt6_insert_exception() will take care of duplicated exceptions */ + if (rt6_insert_exception(nrt, &res)) { + dst_release_immediate(&nrt->dst); + goto out; + } + + netevent.old = &rt->dst; + netevent.new = &nrt->dst; + netevent.daddr = &msg->dest; + netevent.neigh = neigh; + call_netevent_notifiers(NETEVENT_REDIRECT, &netevent); + +out: + rcu_read_unlock(); + neigh_release(neigh); +} + +#ifdef CONFIG_IPV6_ROUTE_INFO +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) +{ + u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO; + int ifindex = dev->ifindex; + struct fib6_node *fn; + struct fib6_info *rt = NULL; + struct fib6_table *table; + + table = fib6_get_table(net, tb_id); + if (!table) + return NULL; + + rcu_read_lock(); + fn = fib6_locate(&table->tb6_root, prefix, prefixlen, NULL, 0, true); + if (!fn) + goto out; + + for_each_fib6_node_rt_rcu(fn) { + /* these routes do not use nexthops */ + if (rt->nh) + continue; + if (rt->fib6_nh->fib_nh_dev->ifindex != ifindex) + continue; + if (!(rt->fib6_flags & RTF_ROUTEINFO) || + !rt->fib6_nh->fib_nh_gw_family) + continue; + if (!ipv6_addr_equal(&rt->fib6_nh->fib_nh_gw6, gwaddr)) + continue; + if (!fib6_info_hold_safe(rt)) + continue; + break; + } +out: + rcu_read_unlock(); + return rt; +} + +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) +{ + struct fib6_config cfg = { + .fc_metric = IP6_RT_PRIO_USER, + .fc_ifindex = dev->ifindex, + .fc_dst_len = prefixlen, + .fc_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO | + RTF_UP | RTF_PREF(pref), + .fc_protocol = RTPROT_RA, + .fc_type = RTN_UNICAST, + .fc_nlinfo.portid = 0, + .fc_nlinfo.nlh = NULL, + .fc_nlinfo.nl_net = net, + }; + + cfg.fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO; + cfg.fc_dst = *prefix; + cfg.fc_gateway = *gwaddr; + + /* We should treat it as a default route if prefix length is 0. */ + if (!prefixlen) + cfg.fc_flags |= RTF_DEFAULT; + + ip6_route_add(&cfg, GFP_ATOMIC, NULL); + + return rt6_get_route_info(net, prefix, prefixlen, gwaddr, dev); +} +#endif + +struct fib6_info *rt6_get_dflt_router(struct net *net, + const struct in6_addr *addr, + struct net_device *dev) +{ + u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT; + struct fib6_info *rt; + struct fib6_table *table; + + table = fib6_get_table(net, tb_id); + if (!table) + return NULL; + + rcu_read_lock(); + for_each_fib6_node_rt_rcu(&table->tb6_root) { + struct fib6_nh *nh; + + /* RA routes do not use nexthops */ + if (rt->nh) + continue; + + nh = rt->fib6_nh; + if (dev == nh->fib_nh_dev && + ((rt->fib6_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) && + ipv6_addr_equal(&nh->fib_nh_gw6, addr)) + break; + } + if (rt && !fib6_info_hold_safe(rt)) + rt = NULL; + rcu_read_unlock(); + return rt; +} + +struct fib6_info *rt6_add_dflt_router(struct net *net, + const struct in6_addr *gwaddr, + struct net_device *dev, + unsigned int pref) +{ + struct fib6_config cfg = { + .fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT, + .fc_metric = IP6_RT_PRIO_USER, + .fc_ifindex = dev->ifindex, + .fc_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT | + RTF_UP | RTF_EXPIRES | RTF_PREF(pref), + .fc_protocol = RTPROT_RA, + .fc_type = RTN_UNICAST, + .fc_nlinfo.portid = 0, + .fc_nlinfo.nlh = NULL, + .fc_nlinfo.nl_net = net, + }; + + cfg.fc_gateway = *gwaddr; + + if (!ip6_route_add(&cfg, GFP_ATOMIC, NULL)) { + struct fib6_table *table; + + table = fib6_get_table(dev_net(dev), cfg.fc_table); + if (table) + table->flags |= RT6_TABLE_HAS_DFLT_ROUTER; + } + + return rt6_get_dflt_router(net, gwaddr, dev); +} + +static void __rt6_purge_dflt_routers(struct net *net, + struct fib6_table *table) +{ + struct fib6_info *rt; + +restart: + rcu_read_lock(); + for_each_fib6_node_rt_rcu(&table->tb6_root) { + struct net_device *dev = fib6_info_nh_dev(rt); + struct inet6_dev *idev = dev ? __in6_dev_get(dev) : NULL; + + if (rt->fib6_flags & (RTF_DEFAULT | RTF_ADDRCONF) && + (!idev || idev->cnf.accept_ra != 2) && + fib6_info_hold_safe(rt)) { + rcu_read_unlock(); + ip6_del_rt(net, rt, false); + goto restart; + } + } + rcu_read_unlock(); + + table->flags &= ~RT6_TABLE_HAS_DFLT_ROUTER; +} + +void rt6_purge_dflt_routers(struct net *net) +{ + struct fib6_table *table; + struct hlist_head *head; + unsigned int h; + + rcu_read_lock(); + + for (h = 0; h < FIB6_TABLE_HASHSZ; h++) { + head = &net->ipv6.fib_table_hash[h]; + hlist_for_each_entry_rcu(table, head, tb6_hlist) { + if (table->flags & RT6_TABLE_HAS_DFLT_ROUTER) + __rt6_purge_dflt_routers(net, table); + } + } + + rcu_read_unlock(); +} + +static void rtmsg_to_fib6_config(struct net *net, + struct in6_rtmsg *rtmsg, + struct fib6_config *cfg) +{ + *cfg = (struct fib6_config){ + .fc_table = l3mdev_fib_table_by_index(net, rtmsg->rtmsg_ifindex) ? + : RT6_TABLE_MAIN, + .fc_ifindex = rtmsg->rtmsg_ifindex, + .fc_metric = rtmsg->rtmsg_metric ? : IP6_RT_PRIO_USER, + .fc_expires = rtmsg->rtmsg_info, + .fc_dst_len = rtmsg->rtmsg_dst_len, + .fc_src_len = rtmsg->rtmsg_src_len, + .fc_flags = rtmsg->rtmsg_flags, + .fc_type = rtmsg->rtmsg_type, + + .fc_nlinfo.nl_net = net, + + .fc_dst = rtmsg->rtmsg_dst, + .fc_src = rtmsg->rtmsg_src, + .fc_gateway = rtmsg->rtmsg_gateway, + }; +} + +int ipv6_route_ioctl(struct net *net, unsigned int cmd, struct in6_rtmsg *rtmsg) +{ + struct fib6_config cfg; + int err; + + if (cmd != SIOCADDRT && cmd != SIOCDELRT) + return -EINVAL; + if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) + return -EPERM; + + rtmsg_to_fib6_config(net, rtmsg, &cfg); + + rtnl_lock(); + switch (cmd) { + case SIOCADDRT: + err = ip6_route_add(&cfg, GFP_KERNEL, NULL); + break; + case SIOCDELRT: + err = ip6_route_del(&cfg, NULL); + break; + } + rtnl_unlock(); + return err; +} + +/* + * Drop the packet on the floor + */ + +static int ip6_pkt_drop(struct sk_buff *skb, u8 code, int ipstats_mib_noroutes) +{ + struct dst_entry *dst = skb_dst(skb); + struct net *net = dev_net(dst->dev); + struct inet6_dev *idev; + int type; + + if (netif_is_l3_master(skb->dev) || + dst->dev == net->loopback_dev) + idev = __in6_dev_get_safely(dev_get_by_index_rcu(net, IP6CB(skb)->iif)); + else + idev = ip6_dst_idev(dst); + + switch (ipstats_mib_noroutes) { + case IPSTATS_MIB_INNOROUTES: + type = ipv6_addr_type(&ipv6_hdr(skb)->daddr); + if (type == IPV6_ADDR_ANY) { + IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS); + break; + } + fallthrough; + case IPSTATS_MIB_OUTNOROUTES: + IP6_INC_STATS(net, idev, ipstats_mib_noroutes); + break; + } + + /* Start over by dropping the dst for l3mdev case */ + if (netif_is_l3_master(skb->dev)) + skb_dst_drop(skb); + + icmpv6_send(skb, ICMPV6_DEST_UNREACH, code, 0); + kfree_skb(skb); + return 0; +} + +static int ip6_pkt_discard(struct sk_buff *skb) +{ + return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_INNOROUTES); +} + +static int ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb) +{ + skb->dev = skb_dst(skb)->dev; + return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_OUTNOROUTES); +} + +static int ip6_pkt_prohibit(struct sk_buff *skb) +{ + return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_INNOROUTES); +} + +static int ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb) +{ + skb->dev = skb_dst(skb)->dev; + return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES); +} + +/* + * Allocate a dst for local (unicast / anycast) address. + */ + +struct fib6_info *addrconf_f6i_alloc(struct net *net, + struct inet6_dev *idev, + const struct in6_addr *addr, + bool anycast, gfp_t gfp_flags) +{ + struct fib6_config cfg = { + .fc_table = l3mdev_fib_table(idev->dev) ? : RT6_TABLE_LOCAL, + .fc_ifindex = idev->dev->ifindex, + .fc_flags = RTF_UP | RTF_NONEXTHOP, + .fc_dst = *addr, + .fc_dst_len = 128, + .fc_protocol = RTPROT_KERNEL, + .fc_nlinfo.nl_net = net, + .fc_ignore_dev_down = true, + }; + struct fib6_info *f6i; + + if (anycast) { + cfg.fc_type = RTN_ANYCAST; + cfg.fc_flags |= RTF_ANYCAST; + } else { + cfg.fc_type = RTN_LOCAL; + cfg.fc_flags |= RTF_LOCAL; + } + + f6i = ip6_route_info_create(&cfg, gfp_flags, NULL); + if (!IS_ERR(f6i)) { + f6i->dst_nocount = true; + + if (!anycast && + (net->ipv6.devconf_all->disable_policy || + idev->cnf.disable_policy)) + f6i->dst_nopolicy = true; + } + + return f6i; +} + +/* remove deleted ip from prefsrc entries */ +struct arg_dev_net_ip { + struct net_device *dev; + struct net *net; + struct in6_addr *addr; +}; + +static int fib6_remove_prefsrc(struct fib6_info *rt, void *arg) +{ + struct net_device *dev = ((struct arg_dev_net_ip *)arg)->dev; + struct net *net = ((struct arg_dev_net_ip *)arg)->net; + struct in6_addr *addr = ((struct arg_dev_net_ip *)arg)->addr; + + if (!rt->nh && + ((void *)rt->fib6_nh->fib_nh_dev == dev || !dev) && + rt != net->ipv6.fib6_null_entry && + ipv6_addr_equal(addr, &rt->fib6_prefsrc.addr)) { + spin_lock_bh(&rt6_exception_lock); + /* remove prefsrc entry */ + rt->fib6_prefsrc.plen = 0; + spin_unlock_bh(&rt6_exception_lock); + } + return 0; +} + +void rt6_remove_prefsrc(struct inet6_ifaddr *ifp) +{ + struct net *net = dev_net(ifp->idev->dev); + struct arg_dev_net_ip adni = { + .dev = ifp->idev->dev, + .net = net, + .addr = &ifp->addr, + }; + fib6_clean_all(net, fib6_remove_prefsrc, &adni); +} + +#define RTF_RA_ROUTER (RTF_ADDRCONF | RTF_DEFAULT) + +/* Remove routers and update dst entries when gateway turn into host. */ +static int fib6_clean_tohost(struct fib6_info *rt, void *arg) +{ + struct in6_addr *gateway = (struct in6_addr *)arg; + struct fib6_nh *nh; + + /* RA routes do not use nexthops */ + if (rt->nh) + return 0; + + nh = rt->fib6_nh; + if (((rt->fib6_flags & RTF_RA_ROUTER) == RTF_RA_ROUTER) && + nh->fib_nh_gw_family && ipv6_addr_equal(gateway, &nh->fib_nh_gw6)) + return -1; + + /* Further clean up cached routes in exception table. + * This is needed because cached route may have a different + * gateway than its 'parent' in the case of an ip redirect. + */ + fib6_nh_exceptions_clean_tohost(nh, gateway); + + return 0; +} + +void rt6_clean_tohost(struct net *net, struct in6_addr *gateway) +{ + fib6_clean_all(net, fib6_clean_tohost, gateway); +} + +struct arg_netdev_event { + const struct net_device *dev; + union { + unsigned char nh_flags; + unsigned long event; + }; +}; + +static struct fib6_info *rt6_multipath_first_sibling(const struct fib6_info *rt) +{ + struct fib6_info *iter; + struct fib6_node *fn; + + fn = rcu_dereference_protected(rt->fib6_node, + lockdep_is_held(&rt->fib6_table->tb6_lock)); + iter = rcu_dereference_protected(fn->leaf, + lockdep_is_held(&rt->fib6_table->tb6_lock)); + while (iter) { + if (iter->fib6_metric == rt->fib6_metric && + rt6_qualify_for_ecmp(iter)) + return iter; + iter = rcu_dereference_protected(iter->fib6_next, + lockdep_is_held(&rt->fib6_table->tb6_lock)); + } + + return NULL; +} + +/* only called for fib entries with builtin fib6_nh */ +static bool rt6_is_dead(const struct fib6_info *rt) +{ + if (rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD || + (rt->fib6_nh->fib_nh_flags & RTNH_F_LINKDOWN && + ip6_ignore_linkdown(rt->fib6_nh->fib_nh_dev))) + return true; + + return false; +} + +static int rt6_multipath_total_weight(const struct fib6_info *rt) +{ + struct fib6_info *iter; + int total = 0; + + if (!rt6_is_dead(rt)) + total += rt->fib6_nh->fib_nh_weight; + + list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) { + if (!rt6_is_dead(iter)) + total += iter->fib6_nh->fib_nh_weight; + } + + return total; +} + +static void rt6_upper_bound_set(struct fib6_info *rt, int *weight, int total) +{ + int upper_bound = -1; + + if (!rt6_is_dead(rt)) { + *weight += rt->fib6_nh->fib_nh_weight; + upper_bound = DIV_ROUND_CLOSEST_ULL((u64) (*weight) << 31, + total) - 1; + } + atomic_set(&rt->fib6_nh->fib_nh_upper_bound, upper_bound); +} + +static void rt6_multipath_upper_bound_set(struct fib6_info *rt, int total) +{ + struct fib6_info *iter; + int weight = 0; + + rt6_upper_bound_set(rt, &weight, total); + + list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) + rt6_upper_bound_set(iter, &weight, total); +} + +void rt6_multipath_rebalance(struct fib6_info *rt) +{ + struct fib6_info *first; + int total; + + /* In case the entire multipath route was marked for flushing, + * then there is no need to rebalance upon the removal of every + * sibling route. + */ + if (!rt->fib6_nsiblings || rt->should_flush) + return; + + /* During lookup routes are evaluated in order, so we need to + * make sure upper bounds are assigned from the first sibling + * onwards. + */ + first = rt6_multipath_first_sibling(rt); + if (WARN_ON_ONCE(!first)) + return; + + total = rt6_multipath_total_weight(first); + rt6_multipath_upper_bound_set(first, total); +} + +static int fib6_ifup(struct fib6_info *rt, void *p_arg) +{ + const struct arg_netdev_event *arg = p_arg; + struct net *net = dev_net(arg->dev); + + if (rt != net->ipv6.fib6_null_entry && !rt->nh && + rt->fib6_nh->fib_nh_dev == arg->dev) { + rt->fib6_nh->fib_nh_flags &= ~arg->nh_flags; + fib6_update_sernum_upto_root(net, rt); + rt6_multipath_rebalance(rt); + } + + return 0; +} + +void rt6_sync_up(struct net_device *dev, unsigned char nh_flags) +{ + struct arg_netdev_event arg = { + .dev = dev, + { + .nh_flags = nh_flags, + }, + }; + + if (nh_flags & RTNH_F_DEAD && netif_carrier_ok(dev)) + arg.nh_flags |= RTNH_F_LINKDOWN; + + fib6_clean_all(dev_net(dev), fib6_ifup, &arg); +} + +/* only called for fib entries with inline fib6_nh */ +static bool rt6_multipath_uses_dev(const struct fib6_info *rt, + const struct net_device *dev) +{ + struct fib6_info *iter; + + if (rt->fib6_nh->fib_nh_dev == dev) + return true; + list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) + if (iter->fib6_nh->fib_nh_dev == dev) + return true; + + return false; +} + +static void rt6_multipath_flush(struct fib6_info *rt) +{ + struct fib6_info *iter; + + rt->should_flush = 1; + list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) + iter->should_flush = 1; +} + +static unsigned int rt6_multipath_dead_count(const struct fib6_info *rt, + const struct net_device *down_dev) +{ + struct fib6_info *iter; + unsigned int dead = 0; + + if (rt->fib6_nh->fib_nh_dev == down_dev || + rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD) + dead++; + list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) + if (iter->fib6_nh->fib_nh_dev == down_dev || + iter->fib6_nh->fib_nh_flags & RTNH_F_DEAD) + dead++; + + return dead; +} + +static void rt6_multipath_nh_flags_set(struct fib6_info *rt, + const struct net_device *dev, + unsigned char nh_flags) +{ + struct fib6_info *iter; + + if (rt->fib6_nh->fib_nh_dev == dev) + rt->fib6_nh->fib_nh_flags |= nh_flags; + list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) + if (iter->fib6_nh->fib_nh_dev == dev) + iter->fib6_nh->fib_nh_flags |= nh_flags; +} + +/* called with write lock held for table with rt */ +static int fib6_ifdown(struct fib6_info *rt, void *p_arg) +{ + const struct arg_netdev_event *arg = p_arg; + const struct net_device *dev = arg->dev; + struct net *net = dev_net(dev); + + if (rt == net->ipv6.fib6_null_entry || rt->nh) + return 0; + + switch (arg->event) { + case NETDEV_UNREGISTER: + return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0; + case NETDEV_DOWN: + if (rt->should_flush) + return -1; + if (!rt->fib6_nsiblings) + return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0; + if (rt6_multipath_uses_dev(rt, dev)) { + unsigned int count; + + count = rt6_multipath_dead_count(rt, dev); + if (rt->fib6_nsiblings + 1 == count) { + rt6_multipath_flush(rt); + return -1; + } + rt6_multipath_nh_flags_set(rt, dev, RTNH_F_DEAD | + RTNH_F_LINKDOWN); + fib6_update_sernum(net, rt); + rt6_multipath_rebalance(rt); + } + return -2; + case NETDEV_CHANGE: + if (rt->fib6_nh->fib_nh_dev != dev || + rt->fib6_flags & (RTF_LOCAL | RTF_ANYCAST)) + break; + rt->fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN; + rt6_multipath_rebalance(rt); + break; + } + + return 0; +} + +void rt6_sync_down_dev(struct net_device *dev, unsigned long event) +{ + struct arg_netdev_event arg = { + .dev = dev, + { + .event = event, + }, + }; + struct net *net = dev_net(dev); + + if (net->ipv6.sysctl.skip_notify_on_dev_down) + fib6_clean_all_skip_notify(net, fib6_ifdown, &arg); + else + fib6_clean_all(net, fib6_ifdown, &arg); +} + +void rt6_disable_ip(struct net_device *dev, unsigned long event) +{ + rt6_sync_down_dev(dev, event); + rt6_uncached_list_flush_dev(dev_net(dev), dev); + neigh_ifdown(&nd_tbl, dev); +} + +struct rt6_mtu_change_arg { + struct net_device *dev; + unsigned int mtu; + struct fib6_info *f6i; +}; + +static int fib6_nh_mtu_change(struct fib6_nh *nh, void *_arg) +{ + struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *)_arg; + struct fib6_info *f6i = arg->f6i; + + /* For administrative MTU increase, there is no way to discover + * IPv6 PMTU increase, so PMTU increase should be updated here. + * Since RFC 1981 doesn't include administrative MTU increase + * update PMTU increase is a MUST. (i.e. jumbo frame) + */ + if (nh->fib_nh_dev == arg->dev) { + struct inet6_dev *idev = __in6_dev_get(arg->dev); + u32 mtu = f6i->fib6_pmtu; + + if (mtu >= arg->mtu || + (mtu < arg->mtu && mtu == idev->cnf.mtu6)) + fib6_metric_set(f6i, RTAX_MTU, arg->mtu); + + spin_lock_bh(&rt6_exception_lock); + rt6_exceptions_update_pmtu(idev, nh, arg->mtu); + spin_unlock_bh(&rt6_exception_lock); + } + + return 0; +} + +static int rt6_mtu_change_route(struct fib6_info *f6i, void *p_arg) +{ + struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg; + struct inet6_dev *idev; + + /* In IPv6 pmtu discovery is not optional, + so that RTAX_MTU lock cannot disable it. + We still use this lock to block changes + caused by addrconf/ndisc. + */ + + idev = __in6_dev_get(arg->dev); + if (!idev) + return 0; + + if (fib6_metric_locked(f6i, RTAX_MTU)) + return 0; + + arg->f6i = f6i; + if (f6i->nh) { + /* fib6_nh_mtu_change only returns 0, so this is safe */ + return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_mtu_change, + arg); + } + + return fib6_nh_mtu_change(f6i->fib6_nh, arg); +} + +void rt6_mtu_change(struct net_device *dev, unsigned int mtu) +{ + struct rt6_mtu_change_arg arg = { + .dev = dev, + .mtu = mtu, + }; + + fib6_clean_all(dev_net(dev), rt6_mtu_change_route, &arg); +} + +static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = { + [RTA_UNSPEC] = { .strict_start_type = RTA_DPORT + 1 }, + [RTA_GATEWAY] = { .len = sizeof(struct in6_addr) }, + [RTA_PREFSRC] = { .len = sizeof(struct in6_addr) }, + [RTA_OIF] = { .type = NLA_U32 }, + [RTA_IIF] = { .type = NLA_U32 }, + [RTA_PRIORITY] = { .type = NLA_U32 }, + [RTA_METRICS] = { .type = NLA_NESTED }, + [RTA_MULTIPATH] = { .len = sizeof(struct rtnexthop) }, + [RTA_PREF] = { .type = NLA_U8 }, + [RTA_ENCAP_TYPE] = { .type = NLA_U16 }, + [RTA_ENCAP] = { .type = NLA_NESTED }, + [RTA_EXPIRES] = { .type = NLA_U32 }, + [RTA_UID] = { .type = NLA_U32 }, + [RTA_MARK] = { .type = NLA_U32 }, + [RTA_TABLE] = { .type = NLA_U32 }, + [RTA_IP_PROTO] = { .type = NLA_U8 }, + [RTA_SPORT] = { .type = NLA_U16 }, + [RTA_DPORT] = { .type = NLA_U16 }, + [RTA_NH_ID] = { .type = NLA_U32 }, +}; + +static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh, + struct fib6_config *cfg, + struct netlink_ext_ack *extack) +{ + struct rtmsg *rtm; + struct nlattr *tb[RTA_MAX+1]; + unsigned int pref; + int err; + + err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, + rtm_ipv6_policy, extack); + if (err < 0) + goto errout; + + err = -EINVAL; + rtm = nlmsg_data(nlh); + + *cfg = (struct fib6_config){ + .fc_table = rtm->rtm_table, + .fc_dst_len = rtm->rtm_dst_len, + .fc_src_len = rtm->rtm_src_len, + .fc_flags = RTF_UP, + .fc_protocol = rtm->rtm_protocol, + .fc_type = rtm->rtm_type, + + .fc_nlinfo.portid = NETLINK_CB(skb).portid, + .fc_nlinfo.nlh = nlh, + .fc_nlinfo.nl_net = sock_net(skb->sk), + }; + + if (rtm->rtm_type == RTN_UNREACHABLE || + rtm->rtm_type == RTN_BLACKHOLE || + rtm->rtm_type == RTN_PROHIBIT || + rtm->rtm_type == RTN_THROW) + cfg->fc_flags |= RTF_REJECT; + + if (rtm->rtm_type == RTN_LOCAL) + cfg->fc_flags |= RTF_LOCAL; + + if (rtm->rtm_flags & RTM_F_CLONED) + cfg->fc_flags |= RTF_CACHE; + + cfg->fc_flags |= (rtm->rtm_flags & RTNH_F_ONLINK); + + if (tb[RTA_NH_ID]) { + if (tb[RTA_GATEWAY] || tb[RTA_OIF] || + tb[RTA_MULTIPATH] || tb[RTA_ENCAP]) { + NL_SET_ERR_MSG(extack, + "Nexthop specification and nexthop id are mutually exclusive"); + goto errout; + } + cfg->fc_nh_id = nla_get_u32(tb[RTA_NH_ID]); + } + + if (tb[RTA_GATEWAY]) { + cfg->fc_gateway = nla_get_in6_addr(tb[RTA_GATEWAY]); + cfg->fc_flags |= RTF_GATEWAY; + } + if (tb[RTA_VIA]) { + NL_SET_ERR_MSG(extack, "IPv6 does not support RTA_VIA attribute"); + goto errout; + } + + if (tb[RTA_DST]) { + int plen = (rtm->rtm_dst_len + 7) >> 3; + + if (nla_len(tb[RTA_DST]) < plen) + goto errout; + + nla_memcpy(&cfg->fc_dst, tb[RTA_DST], plen); + } + + if (tb[RTA_SRC]) { + int plen = (rtm->rtm_src_len + 7) >> 3; + + if (nla_len(tb[RTA_SRC]) < plen) + goto errout; + + nla_memcpy(&cfg->fc_src, tb[RTA_SRC], plen); + } + + if (tb[RTA_PREFSRC]) + cfg->fc_prefsrc = nla_get_in6_addr(tb[RTA_PREFSRC]); + + if (tb[RTA_OIF]) + cfg->fc_ifindex = nla_get_u32(tb[RTA_OIF]); + + if (tb[RTA_PRIORITY]) + cfg->fc_metric = nla_get_u32(tb[RTA_PRIORITY]); + + if (tb[RTA_METRICS]) { + cfg->fc_mx = nla_data(tb[RTA_METRICS]); + cfg->fc_mx_len = nla_len(tb[RTA_METRICS]); + } + + if (tb[RTA_TABLE]) + cfg->fc_table = nla_get_u32(tb[RTA_TABLE]); + + if (tb[RTA_MULTIPATH]) { + cfg->fc_mp = nla_data(tb[RTA_MULTIPATH]); + cfg->fc_mp_len = nla_len(tb[RTA_MULTIPATH]); + + err = lwtunnel_valid_encap_type_attr(cfg->fc_mp, + cfg->fc_mp_len, extack); + if (err < 0) + goto errout; + } + + if (tb[RTA_PREF]) { + pref = nla_get_u8(tb[RTA_PREF]); + if (pref != ICMPV6_ROUTER_PREF_LOW && + pref != ICMPV6_ROUTER_PREF_HIGH) + pref = ICMPV6_ROUTER_PREF_MEDIUM; + cfg->fc_flags |= RTF_PREF(pref); + } + + if (tb[RTA_ENCAP]) + cfg->fc_encap = tb[RTA_ENCAP]; + + if (tb[RTA_ENCAP_TYPE]) { + cfg->fc_encap_type = nla_get_u16(tb[RTA_ENCAP_TYPE]); + + err = lwtunnel_valid_encap_type(cfg->fc_encap_type, extack); + if (err < 0) + goto errout; + } + + if (tb[RTA_EXPIRES]) { + unsigned long timeout = addrconf_timeout_fixup(nla_get_u32(tb[RTA_EXPIRES]), HZ); + + if (addrconf_finite_timeout(timeout)) { + cfg->fc_expires = jiffies_to_clock_t(timeout * HZ); + cfg->fc_flags |= RTF_EXPIRES; + } + } + + err = 0; +errout: + return err; +} + +struct rt6_nh { + struct fib6_info *fib6_info; + struct fib6_config r_cfg; + struct list_head next; +}; + +static int ip6_route_info_append(struct net *net, + struct list_head *rt6_nh_list, + struct fib6_info *rt, + struct fib6_config *r_cfg) +{ + struct rt6_nh *nh; + int err = -EEXIST; + + list_for_each_entry(nh, rt6_nh_list, next) { + /* check if fib6_info already exists */ + if (rt6_duplicate_nexthop(nh->fib6_info, rt)) + return err; + } + + nh = kzalloc(sizeof(*nh), GFP_KERNEL); + if (!nh) + return -ENOMEM; + nh->fib6_info = rt; + memcpy(&nh->r_cfg, r_cfg, sizeof(*r_cfg)); + list_add_tail(&nh->next, rt6_nh_list); + + return 0; +} + +static void ip6_route_mpath_notify(struct fib6_info *rt, + struct fib6_info *rt_last, + struct nl_info *info, + __u16 nlflags) +{ + /* if this is an APPEND route, then rt points to the first route + * inserted and rt_last points to last route inserted. Userspace + * wants a consistent dump of the route which starts at the first + * nexthop. Since sibling routes are always added at the end of + * the list, find the first sibling of the last route appended + */ + if ((nlflags & NLM_F_APPEND) && rt_last && rt_last->fib6_nsiblings) { + rt = list_first_entry(&rt_last->fib6_siblings, + struct fib6_info, + fib6_siblings); + } + + if (rt) + inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags); +} + +static bool ip6_route_mpath_should_notify(const struct fib6_info *rt) +{ + bool rt_can_ecmp = rt6_qualify_for_ecmp(rt); + bool should_notify = false; + struct fib6_info *leaf; + struct fib6_node *fn; + + rcu_read_lock(); + fn = rcu_dereference(rt->fib6_node); + if (!fn) + goto out; + + leaf = rcu_dereference(fn->leaf); + if (!leaf) + goto out; + + if (rt == leaf || + (rt_can_ecmp && rt->fib6_metric == leaf->fib6_metric && + rt6_qualify_for_ecmp(leaf))) + should_notify = true; +out: + rcu_read_unlock(); + + return should_notify; +} + +static int fib6_gw_from_attr(struct in6_addr *gw, struct nlattr *nla, + struct netlink_ext_ack *extack) +{ + if (nla_len(nla) < sizeof(*gw)) { + NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_GATEWAY"); + return -EINVAL; + } + + *gw = nla_get_in6_addr(nla); + + return 0; +} + +static int ip6_route_multipath_add(struct fib6_config *cfg, + struct netlink_ext_ack *extack) +{ + struct fib6_info *rt_notif = NULL, *rt_last = NULL; + struct nl_info *info = &cfg->fc_nlinfo; + struct fib6_config r_cfg; + struct rtnexthop *rtnh; + struct fib6_info *rt; + struct rt6_nh *err_nh; + struct rt6_nh *nh, *nh_safe; + __u16 nlflags; + int remaining; + int attrlen; + int err = 1; + int nhn = 0; + int replace = (cfg->fc_nlinfo.nlh && + (cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_REPLACE)); + LIST_HEAD(rt6_nh_list); + + nlflags = replace ? NLM_F_REPLACE : NLM_F_CREATE; + if (info->nlh && info->nlh->nlmsg_flags & NLM_F_APPEND) + nlflags |= NLM_F_APPEND; + + remaining = cfg->fc_mp_len; + rtnh = (struct rtnexthop *)cfg->fc_mp; + + /* Parse a Multipath Entry and build a list (rt6_nh_list) of + * fib6_info structs per nexthop + */ + while (rtnh_ok(rtnh, remaining)) { + memcpy(&r_cfg, cfg, sizeof(*cfg)); + if (rtnh->rtnh_ifindex) + r_cfg.fc_ifindex = rtnh->rtnh_ifindex; + + attrlen = rtnh_attrlen(rtnh); + if (attrlen > 0) { + struct nlattr *nla, *attrs = rtnh_attrs(rtnh); + + nla = nla_find(attrs, attrlen, RTA_GATEWAY); + if (nla) { + err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla, + extack); + if (err) + goto cleanup; + + r_cfg.fc_flags |= RTF_GATEWAY; + } + r_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP); + + /* RTA_ENCAP_TYPE length checked in + * lwtunnel_valid_encap_type_attr + */ + nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE); + if (nla) + r_cfg.fc_encap_type = nla_get_u16(nla); + } + + r_cfg.fc_flags |= (rtnh->rtnh_flags & RTNH_F_ONLINK); + rt = ip6_route_info_create(&r_cfg, GFP_KERNEL, extack); + if (IS_ERR(rt)) { + err = PTR_ERR(rt); + rt = NULL; + goto cleanup; + } + if (!rt6_qualify_for_ecmp(rt)) { + err = -EINVAL; + NL_SET_ERR_MSG(extack, + "Device only routes can not be added for IPv6 using the multipath API."); + fib6_info_release(rt); + goto cleanup; + } + + rt->fib6_nh->fib_nh_weight = rtnh->rtnh_hops + 1; + + err = ip6_route_info_append(info->nl_net, &rt6_nh_list, + rt, &r_cfg); + if (err) { + fib6_info_release(rt); + goto cleanup; + } + + rtnh = rtnh_next(rtnh, &remaining); + } + + if (list_empty(&rt6_nh_list)) { + NL_SET_ERR_MSG(extack, + "Invalid nexthop configuration - no valid nexthops"); + return -EINVAL; + } + + /* for add and replace send one notification with all nexthops. + * Skip the notification in fib6_add_rt2node and send one with + * the full route when done + */ + info->skip_notify = 1; + + /* For add and replace, send one notification with all nexthops. For + * append, send one notification with all appended nexthops. + */ + info->skip_notify_kernel = 1; + + err_nh = NULL; + list_for_each_entry(nh, &rt6_nh_list, next) { + err = __ip6_ins_rt(nh->fib6_info, info, extack); + fib6_info_release(nh->fib6_info); + + if (!err) { + /* save reference to last route successfully inserted */ + rt_last = nh->fib6_info; + + /* save reference to first route for notification */ + if (!rt_notif) + rt_notif = nh->fib6_info; + } + + /* nh->fib6_info is used or freed at this point, reset to NULL*/ + nh->fib6_info = NULL; + if (err) { + if (replace && nhn) + NL_SET_ERR_MSG_MOD(extack, + "multipath route replace failed (check consistency of installed routes)"); + err_nh = nh; + goto add_errout; + } + + /* Because each route is added like a single route we remove + * these flags after the first nexthop: if there is a collision, + * we have already failed to add the first nexthop: + * fib6_add_rt2node() has rejected it; when replacing, old + * nexthops have been replaced by first new, the rest should + * be added to it. + */ + if (cfg->fc_nlinfo.nlh) { + cfg->fc_nlinfo.nlh->nlmsg_flags &= ~(NLM_F_EXCL | + NLM_F_REPLACE); + cfg->fc_nlinfo.nlh->nlmsg_flags |= NLM_F_CREATE; + } + nhn++; + } + + /* An in-kernel notification should only be sent in case the new + * multipath route is added as the first route in the node, or if + * it was appended to it. We pass 'rt_notif' since it is the first + * sibling and might allow us to skip some checks in the replace case. + */ + if (ip6_route_mpath_should_notify(rt_notif)) { + enum fib_event_type fib_event; + + if (rt_notif->fib6_nsiblings != nhn - 1) + fib_event = FIB_EVENT_ENTRY_APPEND; + else + fib_event = FIB_EVENT_ENTRY_REPLACE; + + err = call_fib6_multipath_entry_notifiers(info->nl_net, + fib_event, rt_notif, + nhn - 1, extack); + if (err) { + /* Delete all the siblings that were just added */ + err_nh = NULL; + goto add_errout; + } + } + + /* success ... tell user about new route */ + ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags); + goto cleanup; + +add_errout: + /* send notification for routes that were added so that + * the delete notifications sent by ip6_route_del are + * coherent + */ + if (rt_notif) + ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags); + + /* Delete routes that were already added */ + list_for_each_entry(nh, &rt6_nh_list, next) { + if (err_nh == nh) + break; + ip6_route_del(&nh->r_cfg, extack); + } + +cleanup: + list_for_each_entry_safe(nh, nh_safe, &rt6_nh_list, next) { + if (nh->fib6_info) + fib6_info_release(nh->fib6_info); + list_del(&nh->next); + kfree(nh); + } + + return err; +} + +static int ip6_route_multipath_del(struct fib6_config *cfg, + struct netlink_ext_ack *extack) +{ + struct fib6_config r_cfg; + struct rtnexthop *rtnh; + int last_err = 0; + int remaining; + int attrlen; + int err; + + remaining = cfg->fc_mp_len; + rtnh = (struct rtnexthop *)cfg->fc_mp; + + /* Parse a Multipath Entry */ + while (rtnh_ok(rtnh, remaining)) { + memcpy(&r_cfg, cfg, sizeof(*cfg)); + if (rtnh->rtnh_ifindex) + r_cfg.fc_ifindex = rtnh->rtnh_ifindex; + + attrlen = rtnh_attrlen(rtnh); + if (attrlen > 0) { + struct nlattr *nla, *attrs = rtnh_attrs(rtnh); + + nla = nla_find(attrs, attrlen, RTA_GATEWAY); + if (nla) { + err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla, + extack); + if (err) { + last_err = err; + goto next_rtnh; + } + + r_cfg.fc_flags |= RTF_GATEWAY; + } + } + err = ip6_route_del(&r_cfg, extack); + if (err) + last_err = err; + +next_rtnh: + rtnh = rtnh_next(rtnh, &remaining); + } + + return last_err; +} + +static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct fib6_config cfg; + int err; + + err = rtm_to_fib6_config(skb, nlh, &cfg, extack); + if (err < 0) + return err; + + if (cfg.fc_nh_id && + !nexthop_find_by_id(sock_net(skb->sk), cfg.fc_nh_id)) { + NL_SET_ERR_MSG(extack, "Nexthop id does not exist"); + return -EINVAL; + } + + if (cfg.fc_mp) + return ip6_route_multipath_del(&cfg, extack); + else { + cfg.fc_delete_all_nh = 1; + return ip6_route_del(&cfg, extack); + } +} + +static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct fib6_config cfg; + int err; + + err = rtm_to_fib6_config(skb, nlh, &cfg, extack); + if (err < 0) + return err; + + if (cfg.fc_metric == 0) + cfg.fc_metric = IP6_RT_PRIO_USER; + + if (cfg.fc_mp) + return ip6_route_multipath_add(&cfg, extack); + else + return ip6_route_add(&cfg, GFP_KERNEL, extack); +} + +/* add the overhead of this fib6_nh to nexthop_len */ +static int rt6_nh_nlmsg_size(struct fib6_nh *nh, void *arg) +{ + int *nexthop_len = arg; + + *nexthop_len += nla_total_size(0) /* RTA_MULTIPATH */ + + NLA_ALIGN(sizeof(struct rtnexthop)) + + nla_total_size(16); /* RTA_GATEWAY */ + + if (nh->fib_nh_lws) { + /* RTA_ENCAP_TYPE */ + *nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws); + /* RTA_ENCAP */ + *nexthop_len += nla_total_size(2); + } + + return 0; +} + +static size_t rt6_nlmsg_size(struct fib6_info *f6i) +{ + int nexthop_len; + + if (f6i->nh) { + nexthop_len = nla_total_size(4); /* RTA_NH_ID */ + nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_nlmsg_size, + &nexthop_len); + } else { + struct fib6_info *sibling, *next_sibling; + struct fib6_nh *nh = f6i->fib6_nh; + + nexthop_len = 0; + if (f6i->fib6_nsiblings) { + rt6_nh_nlmsg_size(nh, &nexthop_len); + + list_for_each_entry_safe(sibling, next_sibling, + &f6i->fib6_siblings, fib6_siblings) { + rt6_nh_nlmsg_size(sibling->fib6_nh, &nexthop_len); + } + } + nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws); + } + + return NLMSG_ALIGN(sizeof(struct rtmsg)) + + nla_total_size(16) /* RTA_SRC */ + + nla_total_size(16) /* RTA_DST */ + + nla_total_size(16) /* RTA_GATEWAY */ + + nla_total_size(16) /* RTA_PREFSRC */ + + nla_total_size(4) /* RTA_TABLE */ + + nla_total_size(4) /* RTA_IIF */ + + nla_total_size(4) /* RTA_OIF */ + + nla_total_size(4) /* RTA_PRIORITY */ + + RTAX_MAX * nla_total_size(4) /* RTA_METRICS */ + + nla_total_size(sizeof(struct rta_cacheinfo)) + + nla_total_size(TCP_CA_NAME_MAX) /* RTAX_CC_ALGO */ + + nla_total_size(1) /* RTA_PREF */ + + nexthop_len; +} + +static int rt6_fill_node_nexthop(struct sk_buff *skb, struct nexthop *nh, + unsigned char *flags) +{ + if (nexthop_is_multipath(nh)) { + struct nlattr *mp; + + mp = nla_nest_start_noflag(skb, RTA_MULTIPATH); + if (!mp) + goto nla_put_failure; + + if (nexthop_mpath_fill_node(skb, nh, AF_INET6)) + goto nla_put_failure; + + nla_nest_end(skb, mp); + } else { + struct fib6_nh *fib6_nh; + + fib6_nh = nexthop_fib6_nh(nh); + if (fib_nexthop_info(skb, &fib6_nh->nh_common, AF_INET6, + flags, false) < 0) + goto nla_put_failure; + } + + return 0; + +nla_put_failure: + return -EMSGSIZE; +} + +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) +{ + struct rt6_info *rt6 = (struct rt6_info *)dst; + struct rt6key *rt6_dst, *rt6_src; + u32 *pmetrics, table, rt6_flags; + unsigned char nh_flags = 0; + struct nlmsghdr *nlh; + struct rtmsg *rtm; + long expires = 0; + + nlh = nlmsg_put(skb, portid, seq, type, sizeof(*rtm), flags); + if (!nlh) + return -EMSGSIZE; + + if (rt6) { + rt6_dst = &rt6->rt6i_dst; + rt6_src = &rt6->rt6i_src; + rt6_flags = rt6->rt6i_flags; + } else { + rt6_dst = &rt->fib6_dst; + rt6_src = &rt->fib6_src; + rt6_flags = rt->fib6_flags; + } + + rtm = nlmsg_data(nlh); + rtm->rtm_family = AF_INET6; + rtm->rtm_dst_len = rt6_dst->plen; + rtm->rtm_src_len = rt6_src->plen; + rtm->rtm_tos = 0; + if (rt->fib6_table) + table = rt->fib6_table->tb6_id; + else + table = RT6_TABLE_UNSPEC; + rtm->rtm_table = table < 256 ? table : RT_TABLE_COMPAT; + if (nla_put_u32(skb, RTA_TABLE, table)) + goto nla_put_failure; + + rtm->rtm_type = rt->fib6_type; + rtm->rtm_flags = 0; + rtm->rtm_scope = RT_SCOPE_UNIVERSE; + rtm->rtm_protocol = rt->fib6_protocol; + + if (rt6_flags & RTF_CACHE) + rtm->rtm_flags |= RTM_F_CLONED; + + if (dest) { + if (nla_put_in6_addr(skb, RTA_DST, dest)) + goto nla_put_failure; + rtm->rtm_dst_len = 128; + } else if (rtm->rtm_dst_len) + if (nla_put_in6_addr(skb, RTA_DST, &rt6_dst->addr)) + goto nla_put_failure; +#ifdef CONFIG_IPV6_SUBTREES + if (src) { + if (nla_put_in6_addr(skb, RTA_SRC, src)) + goto nla_put_failure; + rtm->rtm_src_len = 128; + } else if (rtm->rtm_src_len && + nla_put_in6_addr(skb, RTA_SRC, &rt6_src->addr)) + goto nla_put_failure; +#endif + if (iif) { +#ifdef CONFIG_IPV6_MROUTE + if (ipv6_addr_is_multicast(&rt6_dst->addr)) { + int err = ip6mr_get_route(net, skb, rtm, portid); + + if (err == 0) + return 0; + if (err < 0) + goto nla_put_failure; + } else +#endif + if (nla_put_u32(skb, RTA_IIF, iif)) + goto nla_put_failure; + } else if (dest) { + struct in6_addr saddr_buf; + if (ip6_route_get_saddr(net, rt, dest, 0, &saddr_buf) == 0 && + nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf)) + goto nla_put_failure; + } + + if (rt->fib6_prefsrc.plen) { + struct in6_addr saddr_buf; + saddr_buf = rt->fib6_prefsrc.addr; + if (nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf)) + goto nla_put_failure; + } + + pmetrics = dst ? dst_metrics_ptr(dst) : rt->fib6_metrics->metrics; + if (rtnetlink_put_metrics(skb, pmetrics) < 0) + goto nla_put_failure; + + if (nla_put_u32(skb, RTA_PRIORITY, rt->fib6_metric)) + goto nla_put_failure; + + /* For multipath routes, walk the siblings list and add + * each as a nexthop within RTA_MULTIPATH. + */ + if (rt6) { + if (rt6_flags & RTF_GATEWAY && + nla_put_in6_addr(skb, RTA_GATEWAY, &rt6->rt6i_gateway)) + goto nla_put_failure; + + if (dst->dev && nla_put_u32(skb, RTA_OIF, dst->dev->ifindex)) + goto nla_put_failure; + } else if (rt->fib6_nsiblings) { + struct fib6_info *sibling, *next_sibling; + struct nlattr *mp; + + mp = nla_nest_start_noflag(skb, RTA_MULTIPATH); + if (!mp) + goto nla_put_failure; + + if (fib_add_nexthop(skb, &rt->fib6_nh->nh_common, + rt->fib6_nh->fib_nh_weight, AF_INET6, + 0) < 0) + goto nla_put_failure; + + list_for_each_entry_safe(sibling, next_sibling, + &rt->fib6_siblings, fib6_siblings) { + if (fib_add_nexthop(skb, &sibling->fib6_nh->nh_common, + sibling->fib6_nh->fib_nh_weight, + AF_INET6, 0) < 0) + goto nla_put_failure; + } + + nla_nest_end(skb, mp); + } else if (rt->nh) { + if (nla_put_u32(skb, RTA_NH_ID, rt->nh->id)) + goto nla_put_failure; + + if (nexthop_is_blackhole(rt->nh)) + rtm->rtm_type = RTN_BLACKHOLE; + + if (READ_ONCE(net->ipv4.sysctl_nexthop_compat_mode) && + rt6_fill_node_nexthop(skb, rt->nh, &nh_flags) < 0) + goto nla_put_failure; + + rtm->rtm_flags |= nh_flags; + } else { + if (fib_nexthop_info(skb, &rt->fib6_nh->nh_common, AF_INET6, + &nh_flags, false) < 0) + goto nla_put_failure; + + rtm->rtm_flags |= nh_flags; + } + + if (rt6_flags & RTF_EXPIRES) { + expires = dst ? dst->expires : rt->expires; + expires -= jiffies; + } + + if (!dst) { + if (rt->offload) + rtm->rtm_flags |= RTM_F_OFFLOAD; + if (rt->trap) + rtm->rtm_flags |= RTM_F_TRAP; + } + + if (rtnl_put_cacheinfo(skb, dst, 0, expires, dst ? dst->error : 0) < 0) + goto nla_put_failure; + + if (nla_put_u8(skb, RTA_PREF, IPV6_EXTRACT_PREF(rt6_flags))) + goto nla_put_failure; + + + nlmsg_end(skb, nlh); + return 0; + +nla_put_failure: + nlmsg_cancel(skb, nlh); + return -EMSGSIZE; +} + +static int fib6_info_nh_uses_dev(struct fib6_nh *nh, void *arg) +{ + const struct net_device *dev = arg; + + if (nh->fib_nh_dev == dev) + return 1; + + return 0; +} + +static bool fib6_info_uses_dev(const struct fib6_info *f6i, + const struct net_device *dev) +{ + if (f6i->nh) { + struct net_device *_dev = (struct net_device *)dev; + + return !!nexthop_for_each_fib6_nh(f6i->nh, + fib6_info_nh_uses_dev, + _dev); + } + + if (f6i->fib6_nh->fib_nh_dev == dev) + return true; + + if (f6i->fib6_nsiblings) { + struct fib6_info *sibling, *next_sibling; + + list_for_each_entry_safe(sibling, next_sibling, + &f6i->fib6_siblings, fib6_siblings) { + if (sibling->fib6_nh->fib_nh_dev == dev) + return true; + } + } + + return false; +} + +struct fib6_nh_exception_dump_walker { + struct rt6_rtnl_dump_arg *dump; + struct fib6_info *rt; + unsigned int flags; + unsigned int skip; + unsigned int count; +}; + +static int rt6_nh_dump_exceptions(struct fib6_nh *nh, void *arg) +{ + struct fib6_nh_exception_dump_walker *w = arg; + struct rt6_rtnl_dump_arg *dump = w->dump; + struct rt6_exception_bucket *bucket; + struct rt6_exception *rt6_ex; + int i, err; + + bucket = fib6_nh_get_excptn_bucket(nh, NULL); + if (!bucket) + return 0; + + for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) { + hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) { + if (w->skip) { + w->skip--; + continue; + } + + /* Expiration of entries doesn't bump sernum, insertion + * does. Removal is triggered by insertion, so we can + * rely on the fact that if entries change between two + * partial dumps, this node is scanned again completely, + * see rt6_insert_exception() and fib6_dump_table(). + * + * Count expired entries we go through as handled + * entries that we'll skip next time, in case of partial + * node dump. Otherwise, if entries expire meanwhile, + * we'll skip the wrong amount. + */ + if (rt6_check_expired(rt6_ex->rt6i)) { + w->count++; + continue; + } + + err = rt6_fill_node(dump->net, dump->skb, w->rt, + &rt6_ex->rt6i->dst, NULL, NULL, 0, + RTM_NEWROUTE, + NETLINK_CB(dump->cb->skb).portid, + dump->cb->nlh->nlmsg_seq, w->flags); + if (err) + return err; + + w->count++; + } + bucket++; + } + + return 0; +} + +/* Return -1 if done with node, number of handled routes on partial dump */ +int rt6_dump_route(struct fib6_info *rt, void *p_arg, unsigned int skip) +{ + struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg; + struct fib_dump_filter *filter = &arg->filter; + unsigned int flags = NLM_F_MULTI; + struct net *net = arg->net; + int count = 0; + + if (rt == net->ipv6.fib6_null_entry) + return -1; + + if ((filter->flags & RTM_F_PREFIX) && + !(rt->fib6_flags & RTF_PREFIX_RT)) { + /* success since this is not a prefix route */ + return -1; + } + if (filter->filter_set && + ((filter->rt_type && rt->fib6_type != filter->rt_type) || + (filter->dev && !fib6_info_uses_dev(rt, filter->dev)) || + (filter->protocol && rt->fib6_protocol != filter->protocol))) { + return -1; + } + + if (filter->filter_set || + !filter->dump_routes || !filter->dump_exceptions) { + flags |= NLM_F_DUMP_FILTERED; + } + + if (filter->dump_routes) { + if (skip) { + skip--; + } else { + if (rt6_fill_node(net, arg->skb, rt, NULL, NULL, NULL, + 0, RTM_NEWROUTE, + NETLINK_CB(arg->cb->skb).portid, + arg->cb->nlh->nlmsg_seq, flags)) { + return 0; + } + count++; + } + } + + if (filter->dump_exceptions) { + struct fib6_nh_exception_dump_walker w = { .dump = arg, + .rt = rt, + .flags = flags, + .skip = skip, + .count = 0 }; + int err; + + rcu_read_lock(); + if (rt->nh) { + err = nexthop_for_each_fib6_nh(rt->nh, + rt6_nh_dump_exceptions, + &w); + } else { + err = rt6_nh_dump_exceptions(rt->fib6_nh, &w); + } + rcu_read_unlock(); + + if (err) + return count += w.count; + } + + return -1; +} + +static int inet6_rtm_valid_getroute_req(struct sk_buff *skb, + const struct nlmsghdr *nlh, + struct nlattr **tb, + struct netlink_ext_ack *extack) +{ + struct rtmsg *rtm; + int i, err; + + if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) { + NL_SET_ERR_MSG_MOD(extack, + "Invalid header for get route request"); + return -EINVAL; + } + + if (!netlink_strict_get_check(skb)) + return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX, + rtm_ipv6_policy, extack); + + rtm = nlmsg_data(nlh); + if ((rtm->rtm_src_len && rtm->rtm_src_len != 128) || + (rtm->rtm_dst_len && rtm->rtm_dst_len != 128) || + rtm->rtm_table || rtm->rtm_protocol || rtm->rtm_scope || + rtm->rtm_type) { + NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for get route request"); + return -EINVAL; + } + if (rtm->rtm_flags & ~RTM_F_FIB_MATCH) { + NL_SET_ERR_MSG_MOD(extack, + "Invalid flags for get route request"); + return -EINVAL; + } + + err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX, + rtm_ipv6_policy, extack); + if (err) + return err; + + if ((tb[RTA_SRC] && !rtm->rtm_src_len) || + (tb[RTA_DST] && !rtm->rtm_dst_len)) { + NL_SET_ERR_MSG_MOD(extack, "rtm_src_len and rtm_dst_len must be 128 for IPv6"); + return -EINVAL; + } + + for (i = 0; i <= RTA_MAX; i++) { + if (!tb[i]) + continue; + + switch (i) { + case RTA_SRC: + case RTA_DST: + case RTA_IIF: + case RTA_OIF: + case RTA_MARK: + case RTA_UID: + case RTA_SPORT: + case RTA_DPORT: + case RTA_IP_PROTO: + break; + default: + NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in get route request"); + return -EINVAL; + } + } + + return 0; +} + +static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh, + struct netlink_ext_ack *extack) +{ + struct net *net = sock_net(in_skb->sk); + struct nlattr *tb[RTA_MAX+1]; + int err, iif = 0, oif = 0; + struct fib6_info *from; + struct dst_entry *dst; + struct rt6_info *rt; + struct sk_buff *skb; + struct rtmsg *rtm; + struct flowi6 fl6 = {}; + bool fibmatch; + + err = inet6_rtm_valid_getroute_req(in_skb, nlh, tb, extack); + if (err < 0) + goto errout; + + err = -EINVAL; + rtm = nlmsg_data(nlh); + fl6.flowlabel = ip6_make_flowinfo(rtm->rtm_tos, 0); + fibmatch = !!(rtm->rtm_flags & RTM_F_FIB_MATCH); + + if (tb[RTA_SRC]) { + if (nla_len(tb[RTA_SRC]) < sizeof(struct in6_addr)) + goto errout; + + fl6.saddr = *(struct in6_addr *)nla_data(tb[RTA_SRC]); + } + + if (tb[RTA_DST]) { + if (nla_len(tb[RTA_DST]) < sizeof(struct in6_addr)) + goto errout; + + fl6.daddr = *(struct in6_addr *)nla_data(tb[RTA_DST]); + } + + if (tb[RTA_IIF]) + iif = nla_get_u32(tb[RTA_IIF]); + + if (tb[RTA_OIF]) + oif = nla_get_u32(tb[RTA_OIF]); + + if (tb[RTA_MARK]) + fl6.flowi6_mark = nla_get_u32(tb[RTA_MARK]); + + if (tb[RTA_UID]) + fl6.flowi6_uid = make_kuid(current_user_ns(), + nla_get_u32(tb[RTA_UID])); + else + fl6.flowi6_uid = iif ? INVALID_UID : current_uid(); + + if (tb[RTA_SPORT]) + fl6.fl6_sport = nla_get_be16(tb[RTA_SPORT]); + + if (tb[RTA_DPORT]) + fl6.fl6_dport = nla_get_be16(tb[RTA_DPORT]); + + if (tb[RTA_IP_PROTO]) { + err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO], + &fl6.flowi6_proto, AF_INET6, + extack); + if (err) + goto errout; + } + + if (iif) { + struct net_device *dev; + int flags = 0; + + rcu_read_lock(); + + dev = dev_get_by_index_rcu(net, iif); + if (!dev) { + rcu_read_unlock(); + err = -ENODEV; + goto errout; + } + + fl6.flowi6_iif = iif; + + if (!ipv6_addr_any(&fl6.saddr)) + flags |= RT6_LOOKUP_F_HAS_SADDR; + + dst = ip6_route_input_lookup(net, dev, &fl6, NULL, flags); + + rcu_read_unlock(); + } else { + fl6.flowi6_oif = oif; + + dst = ip6_route_output(net, NULL, &fl6); + } + + + rt = container_of(dst, struct rt6_info, dst); + if (rt->dst.error) { + err = rt->dst.error; + ip6_rt_put(rt); + goto errout; + } + + if (rt == net->ipv6.ip6_null_entry) { + err = rt->dst.error; + ip6_rt_put(rt); + goto errout; + } + + skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL); + if (!skb) { + ip6_rt_put(rt); + err = -ENOBUFS; + goto errout; + } + + skb_dst_set(skb, &rt->dst); + + rcu_read_lock(); + from = rcu_dereference(rt->from); + if (from) { + if (fibmatch) + err = rt6_fill_node(net, skb, from, NULL, NULL, NULL, + iif, RTM_NEWROUTE, + NETLINK_CB(in_skb).portid, + nlh->nlmsg_seq, 0); + else + err = rt6_fill_node(net, skb, from, dst, &fl6.daddr, + &fl6.saddr, iif, RTM_NEWROUTE, + NETLINK_CB(in_skb).portid, + nlh->nlmsg_seq, 0); + } else { + err = -ENETUNREACH; + } + rcu_read_unlock(); + + if (err < 0) { + kfree_skb(skb); + goto errout; + } + + err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid); +errout: + return err; +} + +void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info, + unsigned int nlm_flags) +{ + struct sk_buff *skb; + struct net *net = info->nl_net; + u32 seq; + int err; + + err = -ENOBUFS; + seq = info->nlh ? info->nlh->nlmsg_seq : 0; + + skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any()); + if (!skb) + goto errout; + + err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0, + event, info->portid, seq, nlm_flags); + if (err < 0) { + /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */ + WARN_ON(err == -EMSGSIZE); + kfree_skb(skb); + goto errout; + } + rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE, + info->nlh, gfp_any()); + return; +errout: + if (err < 0) + rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err); +} + +void fib6_rt_update(struct net *net, struct fib6_info *rt, + struct nl_info *info) +{ + u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0; + struct sk_buff *skb; + int err = -ENOBUFS; + + /* call_fib6_entry_notifiers will be removed when in-kernel notifier + * is implemented and supported for nexthop objects + */ + call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_REPLACE, rt, NULL); + + skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any()); + if (!skb) + goto errout; + + err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0, + RTM_NEWROUTE, info->portid, seq, NLM_F_REPLACE); + if (err < 0) { + /* -EMSGSIZE implies BUG in rt6_nlmsg_size() */ + WARN_ON(err == -EMSGSIZE); + kfree_skb(skb); + goto errout; + } + rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE, + info->nlh, gfp_any()); + return; +errout: + if (err < 0) + rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err); +} + +static int ip6_route_dev_notify(struct notifier_block *this, + unsigned long event, void *ptr) +{ + struct net_device *dev = netdev_notifier_info_to_dev(ptr); + struct net *net = dev_net(dev); + + if (!(dev->flags & IFF_LOOPBACK)) + return NOTIFY_OK; + + if (event == NETDEV_REGISTER) { + net->ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = dev; + net->ipv6.ip6_null_entry->dst.dev = dev; + net->ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(dev); +#ifdef CONFIG_IPV6_MULTIPLE_TABLES + net->ipv6.ip6_prohibit_entry->dst.dev = dev; + net->ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(dev); + net->ipv6.ip6_blk_hole_entry->dst.dev = dev; + net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev); +#endif + } else if (event == NETDEV_UNREGISTER && + dev->reg_state != NETREG_UNREGISTERED) { + /* NETDEV_UNREGISTER could be fired for multiple times by + * netdev_wait_allrefs(). Make sure we only call this once. + */ + in6_dev_put_clear(&net->ipv6.ip6_null_entry->rt6i_idev); +#ifdef CONFIG_IPV6_MULTIPLE_TABLES + in6_dev_put_clear(&net->ipv6.ip6_prohibit_entry->rt6i_idev); + in6_dev_put_clear(&net->ipv6.ip6_blk_hole_entry->rt6i_idev); +#endif + } + + return NOTIFY_OK; +} + +/* + * /proc + */ + +#ifdef CONFIG_PROC_FS +static int rt6_stats_seq_show(struct seq_file *seq, void *v) +{ + struct net *net = (struct net *)seq->private; + seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n", + net->ipv6.rt6_stats->fib_nodes, + net->ipv6.rt6_stats->fib_route_nodes, + atomic_read(&net->ipv6.rt6_stats->fib_rt_alloc), + net->ipv6.rt6_stats->fib_rt_entries, + net->ipv6.rt6_stats->fib_rt_cache, + dst_entries_get_slow(&net->ipv6.ip6_dst_ops), + net->ipv6.rt6_stats->fib_discarded_routes); + + return 0; +} +#endif /* CONFIG_PROC_FS */ + +#ifdef CONFIG_SYSCTL + +static int ipv6_sysctl_rtcache_flush(struct ctl_table *ctl, int write, + void *buffer, size_t *lenp, loff_t *ppos) +{ + struct net *net; + int delay; + int ret; + if (!write) + return -EINVAL; + + net = (struct net *)ctl->extra1; + delay = net->ipv6.sysctl.flush_delay; + ret = proc_dointvec(ctl, write, buffer, lenp, ppos); + if (ret) + return ret; + + fib6_run_gc(delay <= 0 ? 0 : (unsigned long)delay, net, delay > 0); + return 0; +} + +static struct ctl_table ipv6_route_table_template[] = { + { + .procname = "flush", + .data = &init_net.ipv6.sysctl.flush_delay, + .maxlen = sizeof(int), + .mode = 0200, + .proc_handler = ipv6_sysctl_rtcache_flush + }, + { + .procname = "gc_thresh", + .data = &ip6_dst_ops_template.gc_thresh, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "max_size", + .data = &init_net.ipv6.sysctl.ip6_rt_max_size, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "gc_min_interval", + .data = &init_net.ipv6.sysctl.ip6_rt_gc_min_interval, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_jiffies, + }, + { + .procname = "gc_timeout", + .data = &init_net.ipv6.sysctl.ip6_rt_gc_timeout, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_jiffies, + }, + { + .procname = "gc_interval", + .data = &init_net.ipv6.sysctl.ip6_rt_gc_interval, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_jiffies, + }, + { + .procname = "gc_elasticity", + .data = &init_net.ipv6.sysctl.ip6_rt_gc_elasticity, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "mtu_expires", + .data = &init_net.ipv6.sysctl.ip6_rt_mtu_expires, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_jiffies, + }, + { + .procname = "min_adv_mss", + .data = &init_net.ipv6.sysctl.ip6_rt_min_advmss, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec, + }, + { + .procname = "gc_min_interval_ms", + .data = &init_net.ipv6.sysctl.ip6_rt_gc_min_interval, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_ms_jiffies, + }, + { + .procname = "skip_notify_on_dev_down", + .data = &init_net.ipv6.sysctl.skip_notify_on_dev_down, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, + { } +}; + +struct ctl_table * __net_init ipv6_route_sysctl_init(struct net *net) +{ + struct ctl_table *table; + + table = kmemdup(ipv6_route_table_template, + sizeof(ipv6_route_table_template), + GFP_KERNEL); + + if (table) { + table[0].data = &net->ipv6.sysctl.flush_delay; + table[0].extra1 = net; + table[1].data = &net->ipv6.ip6_dst_ops.gc_thresh; + table[2].data = &net->ipv6.sysctl.ip6_rt_max_size; + table[3].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval; + table[4].data = &net->ipv6.sysctl.ip6_rt_gc_timeout; + table[5].data = &net->ipv6.sysctl.ip6_rt_gc_interval; + table[6].data = &net->ipv6.sysctl.ip6_rt_gc_elasticity; + table[7].data = &net->ipv6.sysctl.ip6_rt_mtu_expires; + table[8].data = &net->ipv6.sysctl.ip6_rt_min_advmss; + table[9].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval; + table[10].data = &net->ipv6.sysctl.skip_notify_on_dev_down; + + /* Don't export sysctls to unprivileged users */ + if (net->user_ns != &init_user_ns) + table[0].procname = NULL; + } + + return table; +} +#endif + +static int __net_init ip6_route_net_init(struct net *net) +{ + int ret = -ENOMEM; + + memcpy(&net->ipv6.ip6_dst_ops, &ip6_dst_ops_template, + sizeof(net->ipv6.ip6_dst_ops)); + + if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0) + goto out_ip6_dst_ops; + + net->ipv6.fib6_null_entry = fib6_info_alloc(GFP_KERNEL, true); + if (!net->ipv6.fib6_null_entry) + goto out_ip6_dst_entries; + memcpy(net->ipv6.fib6_null_entry, &fib6_null_entry_template, + sizeof(*net->ipv6.fib6_null_entry)); + + net->ipv6.ip6_null_entry = kmemdup(&ip6_null_entry_template, + sizeof(*net->ipv6.ip6_null_entry), + GFP_KERNEL); + if (!net->ipv6.ip6_null_entry) + goto out_fib6_null_entry; + net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops; + dst_init_metrics(&net->ipv6.ip6_null_entry->dst, + ip6_template_metrics, true); + INIT_LIST_HEAD(&net->ipv6.ip6_null_entry->rt6i_uncached); + +#ifdef CONFIG_IPV6_MULTIPLE_TABLES + net->ipv6.fib6_has_custom_rules = false; + net->ipv6.ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template, + sizeof(*net->ipv6.ip6_prohibit_entry), + GFP_KERNEL); + if (!net->ipv6.ip6_prohibit_entry) + goto out_ip6_null_entry; + net->ipv6.ip6_prohibit_entry->dst.ops = &net->ipv6.ip6_dst_ops; + dst_init_metrics(&net->ipv6.ip6_prohibit_entry->dst, + ip6_template_metrics, true); + INIT_LIST_HEAD(&net->ipv6.ip6_prohibit_entry->rt6i_uncached); + + net->ipv6.ip6_blk_hole_entry = kmemdup(&ip6_blk_hole_entry_template, + sizeof(*net->ipv6.ip6_blk_hole_entry), + GFP_KERNEL); + if (!net->ipv6.ip6_blk_hole_entry) + goto out_ip6_prohibit_entry; + net->ipv6.ip6_blk_hole_entry->dst.ops = &net->ipv6.ip6_dst_ops; + dst_init_metrics(&net->ipv6.ip6_blk_hole_entry->dst, + ip6_template_metrics, true); + INIT_LIST_HEAD(&net->ipv6.ip6_blk_hole_entry->rt6i_uncached); +#ifdef CONFIG_IPV6_SUBTREES + net->ipv6.fib6_routes_require_src = 0; +#endif +#endif + + net->ipv6.sysctl.flush_delay = 0; + net->ipv6.sysctl.ip6_rt_max_size = INT_MAX; + net->ipv6.sysctl.ip6_rt_gc_min_interval = HZ / 2; + net->ipv6.sysctl.ip6_rt_gc_timeout = 60*HZ; + net->ipv6.sysctl.ip6_rt_gc_interval = 30*HZ; + net->ipv6.sysctl.ip6_rt_gc_elasticity = 9; + net->ipv6.sysctl.ip6_rt_mtu_expires = 10*60*HZ; + net->ipv6.sysctl.ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40; + net->ipv6.sysctl.skip_notify_on_dev_down = 0; + + atomic_set(&net->ipv6.ip6_rt_gc_expire, 30*HZ); + + ret = 0; +out: + return ret; + +#ifdef CONFIG_IPV6_MULTIPLE_TABLES +out_ip6_prohibit_entry: + kfree(net->ipv6.ip6_prohibit_entry); +out_ip6_null_entry: + kfree(net->ipv6.ip6_null_entry); +#endif +out_fib6_null_entry: + kfree(net->ipv6.fib6_null_entry); +out_ip6_dst_entries: + dst_entries_destroy(&net->ipv6.ip6_dst_ops); +out_ip6_dst_ops: + goto out; +} + +static void __net_exit ip6_route_net_exit(struct net *net) +{ + kfree(net->ipv6.fib6_null_entry); + kfree(net->ipv6.ip6_null_entry); +#ifdef CONFIG_IPV6_MULTIPLE_TABLES + kfree(net->ipv6.ip6_prohibit_entry); + kfree(net->ipv6.ip6_blk_hole_entry); +#endif + dst_entries_destroy(&net->ipv6.ip6_dst_ops); +} + +static int __net_init ip6_route_net_init_late(struct net *net) +{ +#ifdef CONFIG_PROC_FS + if (!proc_create_net("ipv6_route", 0, net->proc_net, + &ipv6_route_seq_ops, + sizeof(struct ipv6_route_iter))) + return -ENOMEM; + + if (!proc_create_net_single("rt6_stats", 0444, net->proc_net, + rt6_stats_seq_show, NULL)) { + remove_proc_entry("ipv6_route", net->proc_net); + return -ENOMEM; + } +#endif + return 0; +} + +static void __net_exit ip6_route_net_exit_late(struct net *net) +{ +#ifdef CONFIG_PROC_FS + remove_proc_entry("ipv6_route", net->proc_net); + remove_proc_entry("rt6_stats", net->proc_net); +#endif +} + +static struct pernet_operations ip6_route_net_ops = { + .init = ip6_route_net_init, + .exit = ip6_route_net_exit, +}; + +static int __net_init ipv6_inetpeer_init(struct net *net) +{ + struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL); + + if (!bp) + return -ENOMEM; + inet_peer_base_init(bp); + net->ipv6.peers = bp; + return 0; +} + +static void __net_exit ipv6_inetpeer_exit(struct net *net) +{ + struct inet_peer_base *bp = net->ipv6.peers; + + net->ipv6.peers = NULL; + inetpeer_invalidate_tree(bp); + kfree(bp); +} + +static struct pernet_operations ipv6_inetpeer_ops = { + .init = ipv6_inetpeer_init, + .exit = ipv6_inetpeer_exit, +}; + +static struct pernet_operations ip6_route_net_late_ops = { + .init = ip6_route_net_init_late, + .exit = ip6_route_net_exit_late, +}; + +static struct notifier_block ip6_route_dev_notifier = { + .notifier_call = ip6_route_dev_notify, + .priority = ADDRCONF_NOTIFY_PRIORITY - 10, +}; + +void __init ip6_route_init_special_entries(void) +{ + /* Registering of the loopback is done before this portion of code, + * the loopback reference in rt6_info will not be taken, do it + * manually for init_net */ + init_net.ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = init_net.loopback_dev; + init_net.ipv6.ip6_null_entry->dst.dev = init_net.loopback_dev; + init_net.ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev); + #ifdef CONFIG_IPV6_MULTIPLE_TABLES + init_net.ipv6.ip6_prohibit_entry->dst.dev = init_net.loopback_dev; + init_net.ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev); + init_net.ipv6.ip6_blk_hole_entry->dst.dev = init_net.loopback_dev; + init_net.ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev); + #endif +} + +#if IS_BUILTIN(CONFIG_IPV6) +#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) +DEFINE_BPF_ITER_FUNC(ipv6_route, struct bpf_iter_meta *meta, struct fib6_info *rt) + +BTF_ID_LIST(btf_fib6_info_id) +BTF_ID(struct, fib6_info) + +static const struct bpf_iter_seq_info ipv6_route_seq_info = { + .seq_ops = &ipv6_route_seq_ops, + .init_seq_private = bpf_iter_init_seq_net, + .fini_seq_private = bpf_iter_fini_seq_net, + .seq_priv_size = sizeof(struct ipv6_route_iter), +}; + +static struct bpf_iter_reg ipv6_route_reg_info = { + .target = "ipv6_route", + .ctx_arg_info_size = 1, + .ctx_arg_info = { + { offsetof(struct bpf_iter__ipv6_route, rt), + PTR_TO_BTF_ID_OR_NULL }, + }, + .seq_info = &ipv6_route_seq_info, +}; + +static int __init bpf_iter_register(void) +{ + ipv6_route_reg_info.ctx_arg_info[0].btf_id = *btf_fib6_info_id; + return bpf_iter_reg_target(&ipv6_route_reg_info); +} + +static void bpf_iter_unregister(void) +{ + bpf_iter_unreg_target(&ipv6_route_reg_info); +} +#endif +#endif + +int __init ip6_route_init(void) +{ + int ret; + int cpu; + + ret = -ENOMEM; + ip6_dst_ops_template.kmem_cachep = + kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0, + SLAB_HWCACHE_ALIGN, NULL); + if (!ip6_dst_ops_template.kmem_cachep) + goto out; + + ret = dst_entries_init(&ip6_dst_blackhole_ops); + if (ret) + goto out_kmem_cache; + + ret = register_pernet_subsys(&ipv6_inetpeer_ops); + if (ret) + goto out_dst_entries; + + ret = register_pernet_subsys(&ip6_route_net_ops); + if (ret) + goto out_register_inetpeer; + + ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops_template.kmem_cachep; + + ret = fib6_init(); + if (ret) + goto out_register_subsys; + + ret = xfrm6_init(); + if (ret) + goto out_fib6_init; + + ret = fib6_rules_init(); + if (ret) + goto xfrm6_init; + + ret = register_pernet_subsys(&ip6_route_net_late_ops); + if (ret) + goto fib6_rules_init; + + ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_NEWROUTE, + inet6_rtm_newroute, NULL, 0); + if (ret < 0) + goto out_register_late_subsys; + + ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_DELROUTE, + inet6_rtm_delroute, NULL, 0); + if (ret < 0) + goto out_register_late_subsys; + + ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE, + inet6_rtm_getroute, NULL, + RTNL_FLAG_DOIT_UNLOCKED); + if (ret < 0) + goto out_register_late_subsys; + + ret = register_netdevice_notifier(&ip6_route_dev_notifier); + if (ret) + goto out_register_late_subsys; + +#if IS_BUILTIN(CONFIG_IPV6) +#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) + ret = bpf_iter_register(); + if (ret) + goto out_register_late_subsys; +#endif +#endif + + for_each_possible_cpu(cpu) { + struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu); + + INIT_LIST_HEAD(&ul->head); + spin_lock_init(&ul->lock); + } + +out: + return ret; + +out_register_late_subsys: + rtnl_unregister_all(PF_INET6); + unregister_pernet_subsys(&ip6_route_net_late_ops); +fib6_rules_init: + fib6_rules_cleanup(); +xfrm6_init: + xfrm6_fini(); +out_fib6_init: + fib6_gc_cleanup(); +out_register_subsys: + unregister_pernet_subsys(&ip6_route_net_ops); +out_register_inetpeer: + unregister_pernet_subsys(&ipv6_inetpeer_ops); +out_dst_entries: + dst_entries_destroy(&ip6_dst_blackhole_ops); +out_kmem_cache: + kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep); + goto out; +} + +void ip6_route_cleanup(void) +{ +#if IS_BUILTIN(CONFIG_IPV6) +#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS) + bpf_iter_unregister(); +#endif +#endif + unregister_netdevice_notifier(&ip6_route_dev_notifier); + unregister_pernet_subsys(&ip6_route_net_late_ops); + fib6_rules_cleanup(); + xfrm6_fini(); + fib6_gc_cleanup(); + unregister_pernet_subsys(&ipv6_inetpeer_ops); + unregister_pernet_subsys(&ip6_route_net_ops); + dst_entries_destroy(&ip6_dst_blackhole_ops); + kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep); +} |