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-rw-r--r--net/ipv4/nexthop.c3775
1 files changed, 3775 insertions, 0 deletions
diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c
new file mode 100644
index 000000000..be5498f5d
--- /dev/null
+++ b/net/ipv4/nexthop.c
@@ -0,0 +1,3775 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Generic nexthop implementation
+ *
+ * Copyright (c) 2017-19 Cumulus Networks
+ * Copyright (c) 2017-19 David Ahern <dsa@cumulusnetworks.com>
+ */
+
+#include <linux/nexthop.h>
+#include <linux/rtnetlink.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <net/arp.h>
+#include <net/ipv6_stubs.h>
+#include <net/lwtunnel.h>
+#include <net/ndisc.h>
+#include <net/nexthop.h>
+#include <net/route.h>
+#include <net/sock.h>
+
+#define NH_RES_DEFAULT_IDLE_TIMER (120 * HZ)
+#define NH_RES_DEFAULT_UNBALANCED_TIMER 0 /* No forced rebalancing. */
+
+static void remove_nexthop(struct net *net, struct nexthop *nh,
+ struct nl_info *nlinfo);
+
+#define NH_DEV_HASHBITS 8
+#define NH_DEV_HASHSIZE (1U << NH_DEV_HASHBITS)
+
+static const struct nla_policy rtm_nh_policy_new[] = {
+ [NHA_ID] = { .type = NLA_U32 },
+ [NHA_GROUP] = { .type = NLA_BINARY },
+ [NHA_GROUP_TYPE] = { .type = NLA_U16 },
+ [NHA_BLACKHOLE] = { .type = NLA_FLAG },
+ [NHA_OIF] = { .type = NLA_U32 },
+ [NHA_GATEWAY] = { .type = NLA_BINARY },
+ [NHA_ENCAP_TYPE] = { .type = NLA_U16 },
+ [NHA_ENCAP] = { .type = NLA_NESTED },
+ [NHA_FDB] = { .type = NLA_FLAG },
+ [NHA_RES_GROUP] = { .type = NLA_NESTED },
+};
+
+static const struct nla_policy rtm_nh_policy_get[] = {
+ [NHA_ID] = { .type = NLA_U32 },
+};
+
+static const struct nla_policy rtm_nh_policy_dump[] = {
+ [NHA_OIF] = { .type = NLA_U32 },
+ [NHA_GROUPS] = { .type = NLA_FLAG },
+ [NHA_MASTER] = { .type = NLA_U32 },
+ [NHA_FDB] = { .type = NLA_FLAG },
+};
+
+static const struct nla_policy rtm_nh_res_policy_new[] = {
+ [NHA_RES_GROUP_BUCKETS] = { .type = NLA_U16 },
+ [NHA_RES_GROUP_IDLE_TIMER] = { .type = NLA_U32 },
+ [NHA_RES_GROUP_UNBALANCED_TIMER] = { .type = NLA_U32 },
+};
+
+static const struct nla_policy rtm_nh_policy_dump_bucket[] = {
+ [NHA_ID] = { .type = NLA_U32 },
+ [NHA_OIF] = { .type = NLA_U32 },
+ [NHA_MASTER] = { .type = NLA_U32 },
+ [NHA_RES_BUCKET] = { .type = NLA_NESTED },
+};
+
+static const struct nla_policy rtm_nh_res_bucket_policy_dump[] = {
+ [NHA_RES_BUCKET_NH_ID] = { .type = NLA_U32 },
+};
+
+static const struct nla_policy rtm_nh_policy_get_bucket[] = {
+ [NHA_ID] = { .type = NLA_U32 },
+ [NHA_RES_BUCKET] = { .type = NLA_NESTED },
+};
+
+static const struct nla_policy rtm_nh_res_bucket_policy_get[] = {
+ [NHA_RES_BUCKET_INDEX] = { .type = NLA_U16 },
+};
+
+static bool nexthop_notifiers_is_empty(struct net *net)
+{
+ return !net->nexthop.notifier_chain.head;
+}
+
+static void
+__nh_notifier_single_info_init(struct nh_notifier_single_info *nh_info,
+ const struct nh_info *nhi)
+{
+ nh_info->dev = nhi->fib_nhc.nhc_dev;
+ nh_info->gw_family = nhi->fib_nhc.nhc_gw_family;
+ if (nh_info->gw_family == AF_INET)
+ nh_info->ipv4 = nhi->fib_nhc.nhc_gw.ipv4;
+ else if (nh_info->gw_family == AF_INET6)
+ nh_info->ipv6 = nhi->fib_nhc.nhc_gw.ipv6;
+
+ nh_info->is_reject = nhi->reject_nh;
+ nh_info->is_fdb = nhi->fdb_nh;
+ nh_info->has_encap = !!nhi->fib_nhc.nhc_lwtstate;
+}
+
+static int nh_notifier_single_info_init(struct nh_notifier_info *info,
+ const struct nexthop *nh)
+{
+ struct nh_info *nhi = rtnl_dereference(nh->nh_info);
+
+ info->type = NH_NOTIFIER_INFO_TYPE_SINGLE;
+ info->nh = kzalloc(sizeof(*info->nh), GFP_KERNEL);
+ if (!info->nh)
+ return -ENOMEM;
+
+ __nh_notifier_single_info_init(info->nh, nhi);
+
+ return 0;
+}
+
+static void nh_notifier_single_info_fini(struct nh_notifier_info *info)
+{
+ kfree(info->nh);
+}
+
+static int nh_notifier_mpath_info_init(struct nh_notifier_info *info,
+ struct nh_group *nhg)
+{
+ u16 num_nh = nhg->num_nh;
+ int i;
+
+ info->type = NH_NOTIFIER_INFO_TYPE_GRP;
+ info->nh_grp = kzalloc(struct_size(info->nh_grp, nh_entries, num_nh),
+ GFP_KERNEL);
+ if (!info->nh_grp)
+ return -ENOMEM;
+
+ info->nh_grp->num_nh = num_nh;
+ info->nh_grp->is_fdb = nhg->fdb_nh;
+
+ for (i = 0; i < num_nh; i++) {
+ struct nh_grp_entry *nhge = &nhg->nh_entries[i];
+ struct nh_info *nhi;
+
+ nhi = rtnl_dereference(nhge->nh->nh_info);
+ info->nh_grp->nh_entries[i].id = nhge->nh->id;
+ info->nh_grp->nh_entries[i].weight = nhge->weight;
+ __nh_notifier_single_info_init(&info->nh_grp->nh_entries[i].nh,
+ nhi);
+ }
+
+ return 0;
+}
+
+static int nh_notifier_res_table_info_init(struct nh_notifier_info *info,
+ struct nh_group *nhg)
+{
+ struct nh_res_table *res_table = rtnl_dereference(nhg->res_table);
+ u16 num_nh_buckets = res_table->num_nh_buckets;
+ unsigned long size;
+ u16 i;
+
+ info->type = NH_NOTIFIER_INFO_TYPE_RES_TABLE;
+ size = struct_size(info->nh_res_table, nhs, num_nh_buckets);
+ info->nh_res_table = __vmalloc(size, GFP_KERNEL | __GFP_ZERO |
+ __GFP_NOWARN);
+ if (!info->nh_res_table)
+ return -ENOMEM;
+
+ info->nh_res_table->num_nh_buckets = num_nh_buckets;
+
+ for (i = 0; i < num_nh_buckets; i++) {
+ struct nh_res_bucket *bucket = &res_table->nh_buckets[i];
+ struct nh_grp_entry *nhge;
+ struct nh_info *nhi;
+
+ nhge = rtnl_dereference(bucket->nh_entry);
+ nhi = rtnl_dereference(nhge->nh->nh_info);
+ __nh_notifier_single_info_init(&info->nh_res_table->nhs[i],
+ nhi);
+ }
+
+ return 0;
+}
+
+static int nh_notifier_grp_info_init(struct nh_notifier_info *info,
+ const struct nexthop *nh)
+{
+ struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
+
+ if (nhg->hash_threshold)
+ return nh_notifier_mpath_info_init(info, nhg);
+ else if (nhg->resilient)
+ return nh_notifier_res_table_info_init(info, nhg);
+ return -EINVAL;
+}
+
+static void nh_notifier_grp_info_fini(struct nh_notifier_info *info,
+ const struct nexthop *nh)
+{
+ struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
+
+ if (nhg->hash_threshold)
+ kfree(info->nh_grp);
+ else if (nhg->resilient)
+ vfree(info->nh_res_table);
+}
+
+static int nh_notifier_info_init(struct nh_notifier_info *info,
+ const struct nexthop *nh)
+{
+ info->id = nh->id;
+
+ if (nh->is_group)
+ return nh_notifier_grp_info_init(info, nh);
+ else
+ return nh_notifier_single_info_init(info, nh);
+}
+
+static void nh_notifier_info_fini(struct nh_notifier_info *info,
+ const struct nexthop *nh)
+{
+ if (nh->is_group)
+ nh_notifier_grp_info_fini(info, nh);
+ else
+ nh_notifier_single_info_fini(info);
+}
+
+static int call_nexthop_notifiers(struct net *net,
+ enum nexthop_event_type event_type,
+ struct nexthop *nh,
+ struct netlink_ext_ack *extack)
+{
+ struct nh_notifier_info info = {
+ .net = net,
+ .extack = extack,
+ };
+ int err;
+
+ ASSERT_RTNL();
+
+ if (nexthop_notifiers_is_empty(net))
+ return 0;
+
+ err = nh_notifier_info_init(&info, nh);
+ if (err) {
+ NL_SET_ERR_MSG(extack, "Failed to initialize nexthop notifier info");
+ return err;
+ }
+
+ err = blocking_notifier_call_chain(&net->nexthop.notifier_chain,
+ event_type, &info);
+ nh_notifier_info_fini(&info, nh);
+
+ return notifier_to_errno(err);
+}
+
+static int
+nh_notifier_res_bucket_idle_timer_get(const struct nh_notifier_info *info,
+ bool force, unsigned int *p_idle_timer_ms)
+{
+ struct nh_res_table *res_table;
+ struct nh_group *nhg;
+ struct nexthop *nh;
+ int err = 0;
+
+ /* When 'force' is false, nexthop bucket replacement is performed
+ * because the bucket was deemed to be idle. In this case, capable
+ * listeners can choose to perform an atomic replacement: The bucket is
+ * only replaced if it is inactive. However, if the idle timer interval
+ * is smaller than the interval in which a listener is querying
+ * buckets' activity from the device, then atomic replacement should
+ * not be tried. Pass the idle timer value to listeners, so that they
+ * could determine which type of replacement to perform.
+ */
+ if (force) {
+ *p_idle_timer_ms = 0;
+ return 0;
+ }
+
+ rcu_read_lock();
+
+ nh = nexthop_find_by_id(info->net, info->id);
+ if (!nh) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ nhg = rcu_dereference(nh->nh_grp);
+ res_table = rcu_dereference(nhg->res_table);
+ *p_idle_timer_ms = jiffies_to_msecs(res_table->idle_timer);
+
+out:
+ rcu_read_unlock();
+
+ return err;
+}
+
+static int nh_notifier_res_bucket_info_init(struct nh_notifier_info *info,
+ u16 bucket_index, bool force,
+ struct nh_info *oldi,
+ struct nh_info *newi)
+{
+ unsigned int idle_timer_ms;
+ int err;
+
+ err = nh_notifier_res_bucket_idle_timer_get(info, force,
+ &idle_timer_ms);
+ if (err)
+ return err;
+
+ info->type = NH_NOTIFIER_INFO_TYPE_RES_BUCKET;
+ info->nh_res_bucket = kzalloc(sizeof(*info->nh_res_bucket),
+ GFP_KERNEL);
+ if (!info->nh_res_bucket)
+ return -ENOMEM;
+
+ info->nh_res_bucket->bucket_index = bucket_index;
+ info->nh_res_bucket->idle_timer_ms = idle_timer_ms;
+ info->nh_res_bucket->force = force;
+ __nh_notifier_single_info_init(&info->nh_res_bucket->old_nh, oldi);
+ __nh_notifier_single_info_init(&info->nh_res_bucket->new_nh, newi);
+ return 0;
+}
+
+static void nh_notifier_res_bucket_info_fini(struct nh_notifier_info *info)
+{
+ kfree(info->nh_res_bucket);
+}
+
+static int __call_nexthop_res_bucket_notifiers(struct net *net, u32 nhg_id,
+ u16 bucket_index, bool force,
+ struct nh_info *oldi,
+ struct nh_info *newi,
+ struct netlink_ext_ack *extack)
+{
+ struct nh_notifier_info info = {
+ .net = net,
+ .extack = extack,
+ .id = nhg_id,
+ };
+ int err;
+
+ if (nexthop_notifiers_is_empty(net))
+ return 0;
+
+ err = nh_notifier_res_bucket_info_init(&info, bucket_index, force,
+ oldi, newi);
+ if (err)
+ return err;
+
+ err = blocking_notifier_call_chain(&net->nexthop.notifier_chain,
+ NEXTHOP_EVENT_BUCKET_REPLACE, &info);
+ nh_notifier_res_bucket_info_fini(&info);
+
+ return notifier_to_errno(err);
+}
+
+/* There are three users of RES_TABLE, and NHs etc. referenced from there:
+ *
+ * 1) a collection of callbacks for NH maintenance. This operates under
+ * RTNL,
+ * 2) the delayed work that gradually balances the resilient table,
+ * 3) and nexthop_select_path(), operating under RCU.
+ *
+ * Both the delayed work and the RTNL block are writers, and need to
+ * maintain mutual exclusion. Since there are only two and well-known
+ * writers for each table, the RTNL code can make sure it has exclusive
+ * access thus:
+ *
+ * - Have the DW operate without locking;
+ * - synchronously cancel the DW;
+ * - do the writing;
+ * - if the write was not actually a delete, call upkeep, which schedules
+ * DW again if necessary.
+ *
+ * The functions that are always called from the RTNL context use
+ * rtnl_dereference(). The functions that can also be called from the DW do
+ * a raw dereference and rely on the above mutual exclusion scheme.
+ */
+#define nh_res_dereference(p) (rcu_dereference_raw(p))
+
+static int call_nexthop_res_bucket_notifiers(struct net *net, u32 nhg_id,
+ u16 bucket_index, bool force,
+ struct nexthop *old_nh,
+ struct nexthop *new_nh,
+ struct netlink_ext_ack *extack)
+{
+ struct nh_info *oldi = nh_res_dereference(old_nh->nh_info);
+ struct nh_info *newi = nh_res_dereference(new_nh->nh_info);
+
+ return __call_nexthop_res_bucket_notifiers(net, nhg_id, bucket_index,
+ force, oldi, newi, extack);
+}
+
+static int call_nexthop_res_table_notifiers(struct net *net, struct nexthop *nh,
+ struct netlink_ext_ack *extack)
+{
+ struct nh_notifier_info info = {
+ .net = net,
+ .extack = extack,
+ };
+ struct nh_group *nhg;
+ int err;
+
+ ASSERT_RTNL();
+
+ if (nexthop_notifiers_is_empty(net))
+ return 0;
+
+ /* At this point, the nexthop buckets are still not populated. Only
+ * emit a notification with the logical nexthops, so that a listener
+ * could potentially veto it in case of unsupported configuration.
+ */
+ nhg = rtnl_dereference(nh->nh_grp);
+ err = nh_notifier_mpath_info_init(&info, nhg);
+ if (err) {
+ NL_SET_ERR_MSG(extack, "Failed to initialize nexthop notifier info");
+ return err;
+ }
+
+ err = blocking_notifier_call_chain(&net->nexthop.notifier_chain,
+ NEXTHOP_EVENT_RES_TABLE_PRE_REPLACE,
+ &info);
+ kfree(info.nh_grp);
+
+ return notifier_to_errno(err);
+}
+
+static int call_nexthop_notifier(struct notifier_block *nb, struct net *net,
+ enum nexthop_event_type event_type,
+ struct nexthop *nh,
+ struct netlink_ext_ack *extack)
+{
+ struct nh_notifier_info info = {
+ .net = net,
+ .extack = extack,
+ };
+ int err;
+
+ err = nh_notifier_info_init(&info, nh);
+ if (err)
+ return err;
+
+ err = nb->notifier_call(nb, event_type, &info);
+ nh_notifier_info_fini(&info, nh);
+
+ return notifier_to_errno(err);
+}
+
+static unsigned int nh_dev_hashfn(unsigned int val)
+{
+ unsigned int mask = NH_DEV_HASHSIZE - 1;
+
+ return (val ^
+ (val >> NH_DEV_HASHBITS) ^
+ (val >> (NH_DEV_HASHBITS * 2))) & mask;
+}
+
+static void nexthop_devhash_add(struct net *net, struct nh_info *nhi)
+{
+ struct net_device *dev = nhi->fib_nhc.nhc_dev;
+ struct hlist_head *head;
+ unsigned int hash;
+
+ WARN_ON(!dev);
+
+ hash = nh_dev_hashfn(dev->ifindex);
+ head = &net->nexthop.devhash[hash];
+ hlist_add_head(&nhi->dev_hash, head);
+}
+
+static void nexthop_free_group(struct nexthop *nh)
+{
+ struct nh_group *nhg;
+ int i;
+
+ nhg = rcu_dereference_raw(nh->nh_grp);
+ for (i = 0; i < nhg->num_nh; ++i) {
+ struct nh_grp_entry *nhge = &nhg->nh_entries[i];
+
+ WARN_ON(!list_empty(&nhge->nh_list));
+ nexthop_put(nhge->nh);
+ }
+
+ WARN_ON(nhg->spare == nhg);
+
+ if (nhg->resilient)
+ vfree(rcu_dereference_raw(nhg->res_table));
+
+ kfree(nhg->spare);
+ kfree(nhg);
+}
+
+static void nexthop_free_single(struct nexthop *nh)
+{
+ struct nh_info *nhi;
+
+ nhi = rcu_dereference_raw(nh->nh_info);
+ switch (nhi->family) {
+ case AF_INET:
+ fib_nh_release(nh->net, &nhi->fib_nh);
+ break;
+ case AF_INET6:
+ ipv6_stub->fib6_nh_release(&nhi->fib6_nh);
+ break;
+ }
+ kfree(nhi);
+}
+
+void nexthop_free_rcu(struct rcu_head *head)
+{
+ struct nexthop *nh = container_of(head, struct nexthop, rcu);
+
+ if (nh->is_group)
+ nexthop_free_group(nh);
+ else
+ nexthop_free_single(nh);
+
+ kfree(nh);
+}
+EXPORT_SYMBOL_GPL(nexthop_free_rcu);
+
+static struct nexthop *nexthop_alloc(void)
+{
+ struct nexthop *nh;
+
+ nh = kzalloc(sizeof(struct nexthop), GFP_KERNEL);
+ if (nh) {
+ INIT_LIST_HEAD(&nh->fi_list);
+ INIT_LIST_HEAD(&nh->f6i_list);
+ INIT_LIST_HEAD(&nh->grp_list);
+ INIT_LIST_HEAD(&nh->fdb_list);
+ }
+ return nh;
+}
+
+static struct nh_group *nexthop_grp_alloc(u16 num_nh)
+{
+ struct nh_group *nhg;
+
+ nhg = kzalloc(struct_size(nhg, nh_entries, num_nh), GFP_KERNEL);
+ if (nhg)
+ nhg->num_nh = num_nh;
+
+ return nhg;
+}
+
+static void nh_res_table_upkeep_dw(struct work_struct *work);
+
+static struct nh_res_table *
+nexthop_res_table_alloc(struct net *net, u32 nhg_id, struct nh_config *cfg)
+{
+ const u16 num_nh_buckets = cfg->nh_grp_res_num_buckets;
+ struct nh_res_table *res_table;
+ unsigned long size;
+
+ size = struct_size(res_table, nh_buckets, num_nh_buckets);
+ res_table = __vmalloc(size, GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN);
+ if (!res_table)
+ return NULL;
+
+ res_table->net = net;
+ res_table->nhg_id = nhg_id;
+ INIT_DELAYED_WORK(&res_table->upkeep_dw, &nh_res_table_upkeep_dw);
+ INIT_LIST_HEAD(&res_table->uw_nh_entries);
+ res_table->idle_timer = cfg->nh_grp_res_idle_timer;
+ res_table->unbalanced_timer = cfg->nh_grp_res_unbalanced_timer;
+ res_table->num_nh_buckets = num_nh_buckets;
+ return res_table;
+}
+
+static void nh_base_seq_inc(struct net *net)
+{
+ while (++net->nexthop.seq == 0)
+ ;
+}
+
+/* no reference taken; rcu lock or rtnl must be held */
+struct nexthop *nexthop_find_by_id(struct net *net, u32 id)
+{
+ struct rb_node **pp, *parent = NULL, *next;
+
+ pp = &net->nexthop.rb_root.rb_node;
+ while (1) {
+ struct nexthop *nh;
+
+ next = rcu_dereference_raw(*pp);
+ if (!next)
+ break;
+ parent = next;
+
+ nh = rb_entry(parent, struct nexthop, rb_node);
+ if (id < nh->id)
+ pp = &next->rb_left;
+ else if (id > nh->id)
+ pp = &next->rb_right;
+ else
+ return nh;
+ }
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(nexthop_find_by_id);
+
+/* used for auto id allocation; called with rtnl held */
+static u32 nh_find_unused_id(struct net *net)
+{
+ u32 id_start = net->nexthop.last_id_allocated;
+
+ while (1) {
+ net->nexthop.last_id_allocated++;
+ if (net->nexthop.last_id_allocated == id_start)
+ break;
+
+ if (!nexthop_find_by_id(net, net->nexthop.last_id_allocated))
+ return net->nexthop.last_id_allocated;
+ }
+ return 0;
+}
+
+static void nh_res_time_set_deadline(unsigned long next_time,
+ unsigned long *deadline)
+{
+ if (time_before(next_time, *deadline))
+ *deadline = next_time;
+}
+
+static clock_t nh_res_table_unbalanced_time(struct nh_res_table *res_table)
+{
+ if (list_empty(&res_table->uw_nh_entries))
+ return 0;
+ return jiffies_delta_to_clock_t(jiffies - res_table->unbalanced_since);
+}
+
+static int nla_put_nh_group_res(struct sk_buff *skb, struct nh_group *nhg)
+{
+ struct nh_res_table *res_table = rtnl_dereference(nhg->res_table);
+ struct nlattr *nest;
+
+ nest = nla_nest_start(skb, NHA_RES_GROUP);
+ if (!nest)
+ return -EMSGSIZE;
+
+ if (nla_put_u16(skb, NHA_RES_GROUP_BUCKETS,
+ res_table->num_nh_buckets) ||
+ nla_put_u32(skb, NHA_RES_GROUP_IDLE_TIMER,
+ jiffies_to_clock_t(res_table->idle_timer)) ||
+ nla_put_u32(skb, NHA_RES_GROUP_UNBALANCED_TIMER,
+ jiffies_to_clock_t(res_table->unbalanced_timer)) ||
+ nla_put_u64_64bit(skb, NHA_RES_GROUP_UNBALANCED_TIME,
+ nh_res_table_unbalanced_time(res_table),
+ NHA_RES_GROUP_PAD))
+ goto nla_put_failure;
+
+ nla_nest_end(skb, nest);
+ return 0;
+
+nla_put_failure:
+ nla_nest_cancel(skb, nest);
+ return -EMSGSIZE;
+}
+
+static int nla_put_nh_group(struct sk_buff *skb, struct nh_group *nhg)
+{
+ struct nexthop_grp *p;
+ size_t len = nhg->num_nh * sizeof(*p);
+ struct nlattr *nla;
+ u16 group_type = 0;
+ int i;
+
+ if (nhg->hash_threshold)
+ group_type = NEXTHOP_GRP_TYPE_MPATH;
+ else if (nhg->resilient)
+ group_type = NEXTHOP_GRP_TYPE_RES;
+
+ if (nla_put_u16(skb, NHA_GROUP_TYPE, group_type))
+ goto nla_put_failure;
+
+ nla = nla_reserve(skb, NHA_GROUP, len);
+ if (!nla)
+ goto nla_put_failure;
+
+ p = nla_data(nla);
+ for (i = 0; i < nhg->num_nh; ++i) {
+ p->id = nhg->nh_entries[i].nh->id;
+ p->weight = nhg->nh_entries[i].weight - 1;
+ p += 1;
+ }
+
+ if (nhg->resilient && nla_put_nh_group_res(skb, nhg))
+ goto nla_put_failure;
+
+ return 0;
+
+nla_put_failure:
+ return -EMSGSIZE;
+}
+
+static int nh_fill_node(struct sk_buff *skb, struct nexthop *nh,
+ int event, u32 portid, u32 seq, unsigned int nlflags)
+{
+ struct fib6_nh *fib6_nh;
+ struct fib_nh *fib_nh;
+ struct nlmsghdr *nlh;
+ struct nh_info *nhi;
+ struct nhmsg *nhm;
+
+ nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nhm), nlflags);
+ if (!nlh)
+ return -EMSGSIZE;
+
+ nhm = nlmsg_data(nlh);
+ nhm->nh_family = AF_UNSPEC;
+ nhm->nh_flags = nh->nh_flags;
+ nhm->nh_protocol = nh->protocol;
+ nhm->nh_scope = 0;
+ nhm->resvd = 0;
+
+ if (nla_put_u32(skb, NHA_ID, nh->id))
+ goto nla_put_failure;
+
+ if (nh->is_group) {
+ struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
+
+ if (nhg->fdb_nh && nla_put_flag(skb, NHA_FDB))
+ goto nla_put_failure;
+ if (nla_put_nh_group(skb, nhg))
+ goto nla_put_failure;
+ goto out;
+ }
+
+ nhi = rtnl_dereference(nh->nh_info);
+ nhm->nh_family = nhi->family;
+ if (nhi->reject_nh) {
+ if (nla_put_flag(skb, NHA_BLACKHOLE))
+ goto nla_put_failure;
+ goto out;
+ } else if (nhi->fdb_nh) {
+ if (nla_put_flag(skb, NHA_FDB))
+ goto nla_put_failure;
+ } else {
+ const struct net_device *dev;
+
+ dev = nhi->fib_nhc.nhc_dev;
+ if (dev && nla_put_u32(skb, NHA_OIF, dev->ifindex))
+ goto nla_put_failure;
+ }
+
+ nhm->nh_scope = nhi->fib_nhc.nhc_scope;
+ switch (nhi->family) {
+ case AF_INET:
+ fib_nh = &nhi->fib_nh;
+ if (fib_nh->fib_nh_gw_family &&
+ nla_put_be32(skb, NHA_GATEWAY, fib_nh->fib_nh_gw4))
+ goto nla_put_failure;
+ break;
+
+ case AF_INET6:
+ fib6_nh = &nhi->fib6_nh;
+ if (fib6_nh->fib_nh_gw_family &&
+ nla_put_in6_addr(skb, NHA_GATEWAY, &fib6_nh->fib_nh_gw6))
+ goto nla_put_failure;
+ break;
+ }
+
+ if (nhi->fib_nhc.nhc_lwtstate &&
+ lwtunnel_fill_encap(skb, nhi->fib_nhc.nhc_lwtstate,
+ NHA_ENCAP, NHA_ENCAP_TYPE) < 0)
+ goto nla_put_failure;
+
+out:
+ nlmsg_end(skb, nlh);
+ return 0;
+
+nla_put_failure:
+ nlmsg_cancel(skb, nlh);
+ return -EMSGSIZE;
+}
+
+static size_t nh_nlmsg_size_grp_res(struct nh_group *nhg)
+{
+ return nla_total_size(0) + /* NHA_RES_GROUP */
+ nla_total_size(2) + /* NHA_RES_GROUP_BUCKETS */
+ nla_total_size(4) + /* NHA_RES_GROUP_IDLE_TIMER */
+ nla_total_size(4) + /* NHA_RES_GROUP_UNBALANCED_TIMER */
+ nla_total_size_64bit(8);/* NHA_RES_GROUP_UNBALANCED_TIME */
+}
+
+static size_t nh_nlmsg_size_grp(struct nexthop *nh)
+{
+ struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
+ size_t sz = sizeof(struct nexthop_grp) * nhg->num_nh;
+ size_t tot = nla_total_size(sz) +
+ nla_total_size(2); /* NHA_GROUP_TYPE */
+
+ if (nhg->resilient)
+ tot += nh_nlmsg_size_grp_res(nhg);
+
+ return tot;
+}
+
+static size_t nh_nlmsg_size_single(struct nexthop *nh)
+{
+ struct nh_info *nhi = rtnl_dereference(nh->nh_info);
+ size_t sz;
+
+ /* covers NHA_BLACKHOLE since NHA_OIF and BLACKHOLE
+ * are mutually exclusive
+ */
+ sz = nla_total_size(4); /* NHA_OIF */
+
+ switch (nhi->family) {
+ case AF_INET:
+ if (nhi->fib_nh.fib_nh_gw_family)
+ sz += nla_total_size(4); /* NHA_GATEWAY */
+ break;
+
+ case AF_INET6:
+ /* NHA_GATEWAY */
+ if (nhi->fib6_nh.fib_nh_gw_family)
+ sz += nla_total_size(sizeof(const struct in6_addr));
+ break;
+ }
+
+ if (nhi->fib_nhc.nhc_lwtstate) {
+ sz += lwtunnel_get_encap_size(nhi->fib_nhc.nhc_lwtstate);
+ sz += nla_total_size(2); /* NHA_ENCAP_TYPE */
+ }
+
+ return sz;
+}
+
+static size_t nh_nlmsg_size(struct nexthop *nh)
+{
+ size_t sz = NLMSG_ALIGN(sizeof(struct nhmsg));
+
+ sz += nla_total_size(4); /* NHA_ID */
+
+ if (nh->is_group)
+ sz += nh_nlmsg_size_grp(nh);
+ else
+ sz += nh_nlmsg_size_single(nh);
+
+ return sz;
+}
+
+static void nexthop_notify(int event, struct nexthop *nh, struct nl_info *info)
+{
+ unsigned int nlflags = info->nlh ? info->nlh->nlmsg_flags : 0;
+ u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
+ struct sk_buff *skb;
+ int err = -ENOBUFS;
+
+ skb = nlmsg_new(nh_nlmsg_size(nh), gfp_any());
+ if (!skb)
+ goto errout;
+
+ err = nh_fill_node(skb, nh, event, info->portid, seq, nlflags);
+ if (err < 0) {
+ /* -EMSGSIZE implies BUG in nh_nlmsg_size() */
+ WARN_ON(err == -EMSGSIZE);
+ kfree_skb(skb);
+ goto errout;
+ }
+
+ rtnl_notify(skb, info->nl_net, info->portid, RTNLGRP_NEXTHOP,
+ info->nlh, gfp_any());
+ return;
+errout:
+ if (err < 0)
+ rtnl_set_sk_err(info->nl_net, RTNLGRP_NEXTHOP, err);
+}
+
+static unsigned long nh_res_bucket_used_time(const struct nh_res_bucket *bucket)
+{
+ return (unsigned long)atomic_long_read(&bucket->used_time);
+}
+
+static unsigned long
+nh_res_bucket_idle_point(const struct nh_res_table *res_table,
+ const struct nh_res_bucket *bucket,
+ unsigned long now)
+{
+ unsigned long time = nh_res_bucket_used_time(bucket);
+
+ /* Bucket was not used since it was migrated. The idle time is now. */
+ if (time == bucket->migrated_time)
+ return now;
+
+ return time + res_table->idle_timer;
+}
+
+static unsigned long
+nh_res_table_unb_point(const struct nh_res_table *res_table)
+{
+ return res_table->unbalanced_since + res_table->unbalanced_timer;
+}
+
+static void nh_res_bucket_set_idle(const struct nh_res_table *res_table,
+ struct nh_res_bucket *bucket)
+{
+ unsigned long now = jiffies;
+
+ atomic_long_set(&bucket->used_time, (long)now);
+ bucket->migrated_time = now;
+}
+
+static void nh_res_bucket_set_busy(struct nh_res_bucket *bucket)
+{
+ atomic_long_set(&bucket->used_time, (long)jiffies);
+}
+
+static clock_t nh_res_bucket_idle_time(const struct nh_res_bucket *bucket)
+{
+ unsigned long used_time = nh_res_bucket_used_time(bucket);
+
+ return jiffies_delta_to_clock_t(jiffies - used_time);
+}
+
+static int nh_fill_res_bucket(struct sk_buff *skb, struct nexthop *nh,
+ struct nh_res_bucket *bucket, u16 bucket_index,
+ int event, u32 portid, u32 seq,
+ unsigned int nlflags,
+ struct netlink_ext_ack *extack)
+{
+ struct nh_grp_entry *nhge = nh_res_dereference(bucket->nh_entry);
+ struct nlmsghdr *nlh;
+ struct nlattr *nest;
+ struct nhmsg *nhm;
+
+ nlh = nlmsg_put(skb, portid, seq, event, sizeof(*nhm), nlflags);
+ if (!nlh)
+ return -EMSGSIZE;
+
+ nhm = nlmsg_data(nlh);
+ nhm->nh_family = AF_UNSPEC;
+ nhm->nh_flags = bucket->nh_flags;
+ nhm->nh_protocol = nh->protocol;
+ nhm->nh_scope = 0;
+ nhm->resvd = 0;
+
+ if (nla_put_u32(skb, NHA_ID, nh->id))
+ goto nla_put_failure;
+
+ nest = nla_nest_start(skb, NHA_RES_BUCKET);
+ if (!nest)
+ goto nla_put_failure;
+
+ if (nla_put_u16(skb, NHA_RES_BUCKET_INDEX, bucket_index) ||
+ nla_put_u32(skb, NHA_RES_BUCKET_NH_ID, nhge->nh->id) ||
+ nla_put_u64_64bit(skb, NHA_RES_BUCKET_IDLE_TIME,
+ nh_res_bucket_idle_time(bucket),
+ NHA_RES_BUCKET_PAD))
+ goto nla_put_failure_nest;
+
+ nla_nest_end(skb, nest);
+ nlmsg_end(skb, nlh);
+ return 0;
+
+nla_put_failure_nest:
+ nla_nest_cancel(skb, nest);
+nla_put_failure:
+ nlmsg_cancel(skb, nlh);
+ return -EMSGSIZE;
+}
+
+static void nexthop_bucket_notify(struct nh_res_table *res_table,
+ u16 bucket_index)
+{
+ struct nh_res_bucket *bucket = &res_table->nh_buckets[bucket_index];
+ struct nh_grp_entry *nhge = nh_res_dereference(bucket->nh_entry);
+ struct nexthop *nh = nhge->nh_parent;
+ struct sk_buff *skb;
+ int err = -ENOBUFS;
+
+ skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
+ if (!skb)
+ goto errout;
+
+ err = nh_fill_res_bucket(skb, nh, bucket, bucket_index,
+ RTM_NEWNEXTHOPBUCKET, 0, 0, NLM_F_REPLACE,
+ NULL);
+ if (err < 0) {
+ kfree_skb(skb);
+ goto errout;
+ }
+
+ rtnl_notify(skb, nh->net, 0, RTNLGRP_NEXTHOP, NULL, GFP_KERNEL);
+ return;
+errout:
+ if (err < 0)
+ rtnl_set_sk_err(nh->net, RTNLGRP_NEXTHOP, err);
+}
+
+static bool valid_group_nh(struct nexthop *nh, unsigned int npaths,
+ bool *is_fdb, struct netlink_ext_ack *extack)
+{
+ if (nh->is_group) {
+ struct nh_group *nhg = rtnl_dereference(nh->nh_grp);
+
+ /* Nesting groups within groups is not supported. */
+ if (nhg->hash_threshold) {
+ NL_SET_ERR_MSG(extack,
+ "Hash-threshold group can not be a nexthop within a group");
+ return false;
+ }
+ if (nhg->resilient) {
+ NL_SET_ERR_MSG(extack,
+ "Resilient group can not be a nexthop within a group");
+ return false;
+ }
+ *is_fdb = nhg->fdb_nh;
+ } else {
+ struct nh_info *nhi = rtnl_dereference(nh->nh_info);
+
+ if (nhi->reject_nh && npaths > 1) {
+ NL_SET_ERR_MSG(extack,
+ "Blackhole nexthop can not be used in a group with more than 1 path");
+ return false;
+ }
+ *is_fdb = nhi->fdb_nh;
+ }
+
+ return true;
+}
+
+static int nh_check_attr_fdb_group(struct nexthop *nh, u8 *nh_family,
+ struct netlink_ext_ack *extack)
+{
+ struct nh_info *nhi;
+
+ nhi = rtnl_dereference(nh->nh_info);
+
+ if (!nhi->fdb_nh) {
+ NL_SET_ERR_MSG(extack, "FDB nexthop group can only have fdb nexthops");
+ return -EINVAL;
+ }
+
+ if (*nh_family == AF_UNSPEC) {
+ *nh_family = nhi->family;
+ } else if (*nh_family != nhi->family) {
+ NL_SET_ERR_MSG(extack, "FDB nexthop group cannot have mixed family nexthops");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int nh_check_attr_group(struct net *net,
+ struct nlattr *tb[], size_t tb_size,
+ u16 nh_grp_type, struct netlink_ext_ack *extack)
+{
+ unsigned int len = nla_len(tb[NHA_GROUP]);
+ u8 nh_family = AF_UNSPEC;
+ struct nexthop_grp *nhg;
+ unsigned int i, j;
+ u8 nhg_fdb = 0;
+
+ if (!len || len & (sizeof(struct nexthop_grp) - 1)) {
+ NL_SET_ERR_MSG(extack,
+ "Invalid length for nexthop group attribute");
+ return -EINVAL;
+ }
+
+ /* convert len to number of nexthop ids */
+ len /= sizeof(*nhg);
+
+ nhg = nla_data(tb[NHA_GROUP]);
+ for (i = 0; i < len; ++i) {
+ if (nhg[i].resvd1 || nhg[i].resvd2) {
+ NL_SET_ERR_MSG(extack, "Reserved fields in nexthop_grp must be 0");
+ return -EINVAL;
+ }
+ if (nhg[i].weight > 254) {
+ NL_SET_ERR_MSG(extack, "Invalid value for weight");
+ return -EINVAL;
+ }
+ for (j = i + 1; j < len; ++j) {
+ if (nhg[i].id == nhg[j].id) {
+ NL_SET_ERR_MSG(extack, "Nexthop id can not be used twice in a group");
+ return -EINVAL;
+ }
+ }
+ }
+
+ if (tb[NHA_FDB])
+ nhg_fdb = 1;
+ nhg = nla_data(tb[NHA_GROUP]);
+ for (i = 0; i < len; ++i) {
+ struct nexthop *nh;
+ bool is_fdb_nh;
+
+ nh = nexthop_find_by_id(net, nhg[i].id);
+ if (!nh) {
+ NL_SET_ERR_MSG(extack, "Invalid nexthop id");
+ return -EINVAL;
+ }
+ if (!valid_group_nh(nh, len, &is_fdb_nh, extack))
+ return -EINVAL;
+
+ if (nhg_fdb && nh_check_attr_fdb_group(nh, &nh_family, extack))
+ return -EINVAL;
+
+ if (!nhg_fdb && is_fdb_nh) {
+ NL_SET_ERR_MSG(extack, "Non FDB nexthop group cannot have fdb nexthops");
+ return -EINVAL;
+ }
+ }
+ for (i = NHA_GROUP_TYPE + 1; i < tb_size; ++i) {
+ if (!tb[i])
+ continue;
+ switch (i) {
+ case NHA_FDB:
+ continue;
+ case NHA_RES_GROUP:
+ if (nh_grp_type == NEXTHOP_GRP_TYPE_RES)
+ continue;
+ break;
+ }
+ NL_SET_ERR_MSG(extack,
+ "No other attributes can be set in nexthop groups");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static bool ipv6_good_nh(const struct fib6_nh *nh)
+{
+ int state = NUD_REACHABLE;
+ struct neighbour *n;
+
+ rcu_read_lock();
+
+ n = __ipv6_neigh_lookup_noref_stub(nh->fib_nh_dev, &nh->fib_nh_gw6);
+ if (n)
+ state = READ_ONCE(n->nud_state);
+
+ rcu_read_unlock();
+
+ return !!(state & NUD_VALID);
+}
+
+static bool ipv4_good_nh(const struct fib_nh *nh)
+{
+ int state = NUD_REACHABLE;
+ struct neighbour *n;
+
+ rcu_read_lock();
+
+ n = __ipv4_neigh_lookup_noref(nh->fib_nh_dev,
+ (__force u32)nh->fib_nh_gw4);
+ if (n)
+ state = READ_ONCE(n->nud_state);
+
+ rcu_read_unlock();
+
+ return !!(state & NUD_VALID);
+}
+
+static struct nexthop *nexthop_select_path_hthr(struct nh_group *nhg, int hash)
+{
+ struct nexthop *rc = NULL;
+ int i;
+
+ for (i = 0; i < nhg->num_nh; ++i) {
+ struct nh_grp_entry *nhge = &nhg->nh_entries[i];
+ struct nh_info *nhi;
+
+ if (hash > atomic_read(&nhge->hthr.upper_bound))
+ continue;
+
+ nhi = rcu_dereference(nhge->nh->nh_info);
+ if (nhi->fdb_nh)
+ return nhge->nh;
+
+ /* nexthops always check if it is good and does
+ * not rely on a sysctl for this behavior
+ */
+ switch (nhi->family) {
+ case AF_INET:
+ if (ipv4_good_nh(&nhi->fib_nh))
+ return nhge->nh;
+ break;
+ case AF_INET6:
+ if (ipv6_good_nh(&nhi->fib6_nh))
+ return nhge->nh;
+ break;
+ }
+
+ if (!rc)
+ rc = nhge->nh;
+ }
+
+ return rc;
+}
+
+static struct nexthop *nexthop_select_path_res(struct nh_group *nhg, int hash)
+{
+ struct nh_res_table *res_table = rcu_dereference(nhg->res_table);
+ u16 bucket_index = hash % res_table->num_nh_buckets;
+ struct nh_res_bucket *bucket;
+ struct nh_grp_entry *nhge;
+
+ /* nexthop_select_path() is expected to return a non-NULL value, so
+ * skip protocol validation and just hand out whatever there is.
+ */
+ bucket = &res_table->nh_buckets[bucket_index];
+ nh_res_bucket_set_busy(bucket);
+ nhge = rcu_dereference(bucket->nh_entry);
+ return nhge->nh;
+}
+
+struct nexthop *nexthop_select_path(struct nexthop *nh, int hash)
+{
+ struct nh_group *nhg;
+
+ if (!nh->is_group)
+ return nh;
+
+ nhg = rcu_dereference(nh->nh_grp);
+ if (nhg->hash_threshold)
+ return nexthop_select_path_hthr(nhg, hash);
+ else if (nhg->resilient)
+ return nexthop_select_path_res(nhg, hash);
+
+ /* Unreachable. */
+ return NULL;
+}
+EXPORT_SYMBOL_GPL(nexthop_select_path);
+
+int nexthop_for_each_fib6_nh(struct nexthop *nh,
+ int (*cb)(struct fib6_nh *nh, void *arg),
+ void *arg)
+{
+ struct nh_info *nhi;
+ int err;
+
+ if (nh->is_group) {
+ struct nh_group *nhg;
+ int i;
+
+ nhg = rcu_dereference_rtnl(nh->nh_grp);
+ for (i = 0; i < nhg->num_nh; i++) {
+ struct nh_grp_entry *nhge = &nhg->nh_entries[i];
+
+ nhi = rcu_dereference_rtnl(nhge->nh->nh_info);
+ err = cb(&nhi->fib6_nh, arg);
+ if (err)
+ return err;
+ }
+ } else {
+ nhi = rcu_dereference_rtnl(nh->nh_info);
+ err = cb(&nhi->fib6_nh, arg);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(nexthop_for_each_fib6_nh);
+
+static int check_src_addr(const struct in6_addr *saddr,
+ struct netlink_ext_ack *extack)
+{
+ if (!ipv6_addr_any(saddr)) {
+ NL_SET_ERR_MSG(extack, "IPv6 routes using source address can not use nexthop objects");
+ return -EINVAL;
+ }
+ return 0;
+}
+
+int fib6_check_nexthop(struct nexthop *nh, struct fib6_config *cfg,
+ struct netlink_ext_ack *extack)
+{
+ struct nh_info *nhi;
+ bool is_fdb_nh;
+
+ /* fib6_src is unique to a fib6_info and limits the ability to cache
+ * routes in fib6_nh within a nexthop that is potentially shared
+ * across multiple fib entries. If the config wants to use source
+ * routing it can not use nexthop objects. mlxsw also does not allow
+ * fib6_src on routes.
+ */
+ if (cfg && check_src_addr(&cfg->fc_src, extack) < 0)
+ return -EINVAL;
+
+ if (nh->is_group) {
+ struct nh_group *nhg;
+
+ nhg = rtnl_dereference(nh->nh_grp);
+ if (nhg->has_v4)
+ goto no_v4_nh;
+ is_fdb_nh = nhg->fdb_nh;
+ } else {
+ nhi = rtnl_dereference(nh->nh_info);
+ if (nhi->family == AF_INET)
+ goto no_v4_nh;
+ is_fdb_nh = nhi->fdb_nh;
+ }
+
+ if (is_fdb_nh) {
+ NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop");
+ return -EINVAL;
+ }
+
+ return 0;
+no_v4_nh:
+ NL_SET_ERR_MSG(extack, "IPv6 routes can not use an IPv4 nexthop");
+ return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(fib6_check_nexthop);
+
+/* if existing nexthop has ipv6 routes linked to it, need
+ * to verify this new spec works with ipv6
+ */
+static int fib6_check_nh_list(struct nexthop *old, struct nexthop *new,
+ struct netlink_ext_ack *extack)
+{
+ struct fib6_info *f6i;
+
+ if (list_empty(&old->f6i_list))
+ return 0;
+
+ list_for_each_entry(f6i, &old->f6i_list, nh_list) {
+ if (check_src_addr(&f6i->fib6_src.addr, extack) < 0)
+ return -EINVAL;
+ }
+
+ return fib6_check_nexthop(new, NULL, extack);
+}
+
+static int nexthop_check_scope(struct nh_info *nhi, u8 scope,
+ struct netlink_ext_ack *extack)
+{
+ if (scope == RT_SCOPE_HOST && nhi->fib_nhc.nhc_gw_family) {
+ NL_SET_ERR_MSG(extack,
+ "Route with host scope can not have a gateway");
+ return -EINVAL;
+ }
+
+ if (nhi->fib_nhc.nhc_flags & RTNH_F_ONLINK && scope >= RT_SCOPE_LINK) {
+ NL_SET_ERR_MSG(extack, "Scope mismatch with nexthop");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/* Invoked by fib add code to verify nexthop by id is ok with
+ * config for prefix; parts of fib_check_nh not done when nexthop
+ * object is used.
+ */
+int fib_check_nexthop(struct nexthop *nh, u8 scope,
+ struct netlink_ext_ack *extack)
+{
+ struct nh_info *nhi;
+ int err = 0;
+
+ if (nh->is_group) {
+ struct nh_group *nhg;
+
+ nhg = rtnl_dereference(nh->nh_grp);
+ if (nhg->fdb_nh) {
+ NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop");
+ err = -EINVAL;
+ goto out;
+ }
+
+ if (scope == RT_SCOPE_HOST) {
+ NL_SET_ERR_MSG(extack, "Route with host scope can not have multiple nexthops");
+ err = -EINVAL;
+ goto out;
+ }
+
+ /* all nexthops in a group have the same scope */
+ nhi = rtnl_dereference(nhg->nh_entries[0].nh->nh_info);
+ err = nexthop_check_scope(nhi, scope, extack);
+ } else {
+ nhi = rtnl_dereference(nh->nh_info);
+ if (nhi->fdb_nh) {
+ NL_SET_ERR_MSG(extack, "Route cannot point to a fdb nexthop");
+ err = -EINVAL;
+ goto out;
+ }
+ err = nexthop_check_scope(nhi, scope, extack);
+ }
+
+out:
+ return err;
+}
+
+static int fib_check_nh_list(struct nexthop *old, struct nexthop *new,
+ struct netlink_ext_ack *extack)
+{
+ struct fib_info *fi;
+
+ list_for_each_entry(fi, &old->fi_list, nh_list) {
+ int err;
+
+ err = fib_check_nexthop(new, fi->fib_scope, extack);
+ if (err)
+ return err;
+ }
+ return 0;
+}
+
+static bool nh_res_nhge_is_balanced(const struct nh_grp_entry *nhge)
+{
+ return nhge->res.count_buckets == nhge->res.wants_buckets;
+}
+
+static bool nh_res_nhge_is_ow(const struct nh_grp_entry *nhge)
+{
+ return nhge->res.count_buckets > nhge->res.wants_buckets;
+}
+
+static bool nh_res_nhge_is_uw(const struct nh_grp_entry *nhge)
+{
+ return nhge->res.count_buckets < nhge->res.wants_buckets;
+}
+
+static bool nh_res_table_is_balanced(const struct nh_res_table *res_table)
+{
+ return list_empty(&res_table->uw_nh_entries);
+}
+
+static void nh_res_bucket_unset_nh(struct nh_res_bucket *bucket)
+{
+ struct nh_grp_entry *nhge;
+
+ if (bucket->occupied) {
+ nhge = nh_res_dereference(bucket->nh_entry);
+ nhge->res.count_buckets--;
+ bucket->occupied = false;
+ }
+}
+
+static void nh_res_bucket_set_nh(struct nh_res_bucket *bucket,
+ struct nh_grp_entry *nhge)
+{
+ nh_res_bucket_unset_nh(bucket);
+
+ bucket->occupied = true;
+ rcu_assign_pointer(bucket->nh_entry, nhge);
+ nhge->res.count_buckets++;
+}
+
+static bool nh_res_bucket_should_migrate(struct nh_res_table *res_table,
+ struct nh_res_bucket *bucket,
+ unsigned long *deadline, bool *force)
+{
+ unsigned long now = jiffies;
+ struct nh_grp_entry *nhge;
+ unsigned long idle_point;
+
+ if (!bucket->occupied) {
+ /* The bucket is not occupied, its NHGE pointer is either
+ * NULL or obsolete. We _have to_ migrate: set force.
+ */
+ *force = true;
+ return true;
+ }
+
+ nhge = nh_res_dereference(bucket->nh_entry);
+
+ /* If the bucket is populated by an underweight or balanced
+ * nexthop, do not migrate.
+ */
+ if (!nh_res_nhge_is_ow(nhge))
+ return false;
+
+ /* At this point we know that the bucket is populated with an
+ * overweight nexthop. It needs to be migrated to a new nexthop if
+ * the idle timer of unbalanced timer expired.
+ */
+
+ idle_point = nh_res_bucket_idle_point(res_table, bucket, now);
+ if (time_after_eq(now, idle_point)) {
+ /* The bucket is idle. We _can_ migrate: unset force. */
+ *force = false;
+ return true;
+ }
+
+ /* Unbalanced timer of 0 means "never force". */
+ if (res_table->unbalanced_timer) {
+ unsigned long unb_point;
+
+ unb_point = nh_res_table_unb_point(res_table);
+ if (time_after(now, unb_point)) {
+ /* The bucket is not idle, but the unbalanced timer
+ * expired. We _can_ migrate, but set force anyway,
+ * so that drivers know to ignore activity reports
+ * from the HW.
+ */
+ *force = true;
+ return true;
+ }
+
+ nh_res_time_set_deadline(unb_point, deadline);
+ }
+
+ nh_res_time_set_deadline(idle_point, deadline);
+ return false;
+}
+
+static bool nh_res_bucket_migrate(struct nh_res_table *res_table,
+ u16 bucket_index, bool notify,
+ bool notify_nl, bool force)
+{
+ struct nh_res_bucket *bucket = &res_table->nh_buckets[bucket_index];
+ struct nh_grp_entry *new_nhge;
+ struct netlink_ext_ack extack;
+ int err;
+
+ new_nhge = list_first_entry_or_null(&res_table->uw_nh_entries,
+ struct nh_grp_entry,
+ res.uw_nh_entry);
+ if (WARN_ON_ONCE(!new_nhge))
+ /* If this function is called, "bucket" is either not
+ * occupied, or it belongs to a next hop that is
+ * overweight. In either case, there ought to be a
+ * corresponding underweight next hop.
+ */
+ return false;
+
+ if (notify) {
+ struct nh_grp_entry *old_nhge;
+
+ old_nhge = nh_res_dereference(bucket->nh_entry);
+ err = call_nexthop_res_bucket_notifiers(res_table->net,
+ res_table->nhg_id,
+ bucket_index, force,
+ old_nhge->nh,
+ new_nhge->nh, &extack);
+ if (err) {
+ pr_err_ratelimited("%s\n", extack._msg);
+ if (!force)
+ return false;
+ /* It is not possible to veto a forced replacement, so
+ * just clear the hardware flags from the nexthop
+ * bucket to indicate to user space that this bucket is
+ * not correctly populated in hardware.
+ */
+ bucket->nh_flags &= ~(RTNH_F_OFFLOAD | RTNH_F_TRAP);
+ }
+ }
+
+ nh_res_bucket_set_nh(bucket, new_nhge);
+ nh_res_bucket_set_idle(res_table, bucket);
+
+ if (notify_nl)
+ nexthop_bucket_notify(res_table, bucket_index);
+
+ if (nh_res_nhge_is_balanced(new_nhge))
+ list_del(&new_nhge->res.uw_nh_entry);
+ return true;
+}
+
+#define NH_RES_UPKEEP_DW_MINIMUM_INTERVAL (HZ / 2)
+
+static void nh_res_table_upkeep(struct nh_res_table *res_table,
+ bool notify, bool notify_nl)
+{
+ unsigned long now = jiffies;
+ unsigned long deadline;
+ u16 i;
+
+ /* Deadline is the next time that upkeep should be run. It is the
+ * earliest time at which one of the buckets might be migrated.
+ * Start at the most pessimistic estimate: either unbalanced_timer
+ * from now, or if there is none, idle_timer from now. For each
+ * encountered time point, call nh_res_time_set_deadline() to
+ * refine the estimate.
+ */
+ if (res_table->unbalanced_timer)
+ deadline = now + res_table->unbalanced_timer;
+ else
+ deadline = now + res_table->idle_timer;
+
+ for (i = 0; i < res_table->num_nh_buckets; i++) {
+ struct nh_res_bucket *bucket = &res_table->nh_buckets[i];
+ bool force;
+
+ if (nh_res_bucket_should_migrate(res_table, bucket,
+ &deadline, &force)) {
+ if (!nh_res_bucket_migrate(res_table, i, notify,
+ notify_nl, force)) {
+ unsigned long idle_point;
+
+ /* A driver can override the migration
+ * decision if the HW reports that the
+ * bucket is actually not idle. Therefore
+ * remark the bucket as busy again and
+ * update the deadline.
+ */
+ nh_res_bucket_set_busy(bucket);
+ idle_point = nh_res_bucket_idle_point(res_table,
+ bucket,
+ now);
+ nh_res_time_set_deadline(idle_point, &deadline);
+ }
+ }
+ }
+
+ /* If the group is still unbalanced, schedule the next upkeep to
+ * either the deadline computed above, or the minimum deadline,
+ * whichever comes later.
+ */
+ if (!nh_res_table_is_balanced(res_table)) {
+ unsigned long now = jiffies;
+ unsigned long min_deadline;
+
+ min_deadline = now + NH_RES_UPKEEP_DW_MINIMUM_INTERVAL;
+ if (time_before(deadline, min_deadline))
+ deadline = min_deadline;
+
+ queue_delayed_work(system_power_efficient_wq,
+ &res_table->upkeep_dw, deadline - now);
+ }
+}
+
+static void nh_res_table_upkeep_dw(struct work_struct *work)
+{
+ struct delayed_work *dw = to_delayed_work(work);
+ struct nh_res_table *res_table;
+
+ res_table = container_of(dw, struct nh_res_table, upkeep_dw);
+ nh_res_table_upkeep(res_table, true, true);
+}
+
+static void nh_res_table_cancel_upkeep(struct nh_res_table *res_table)
+{
+ cancel_delayed_work_sync(&res_table->upkeep_dw);
+}
+
+static void nh_res_group_rebalance(struct nh_group *nhg,
+ struct nh_res_table *res_table)
+{
+ int prev_upper_bound = 0;
+ int total = 0;
+ int w = 0;
+ int i;
+
+ INIT_LIST_HEAD(&res_table->uw_nh_entries);
+
+ for (i = 0; i < nhg->num_nh; ++i)
+ total += nhg->nh_entries[i].weight;
+
+ for (i = 0; i < nhg->num_nh; ++i) {
+ struct nh_grp_entry *nhge = &nhg->nh_entries[i];
+ int upper_bound;
+
+ w += nhge->weight;
+ upper_bound = DIV_ROUND_CLOSEST(res_table->num_nh_buckets * w,
+ total);
+ nhge->res.wants_buckets = upper_bound - prev_upper_bound;
+ prev_upper_bound = upper_bound;
+
+ if (nh_res_nhge_is_uw(nhge)) {
+ if (list_empty(&res_table->uw_nh_entries))
+ res_table->unbalanced_since = jiffies;
+ list_add(&nhge->res.uw_nh_entry,
+ &res_table->uw_nh_entries);
+ }
+ }
+}
+
+/* Migrate buckets in res_table so that they reference NHGE's from NHG with
+ * the right NH ID. Set those buckets that do not have a corresponding NHGE
+ * entry in NHG as not occupied.
+ */
+static void nh_res_table_migrate_buckets(struct nh_res_table *res_table,
+ struct nh_group *nhg)
+{
+ u16 i;
+
+ for (i = 0; i < res_table->num_nh_buckets; i++) {
+ struct nh_res_bucket *bucket = &res_table->nh_buckets[i];
+ u32 id = rtnl_dereference(bucket->nh_entry)->nh->id;
+ bool found = false;
+ int j;
+
+ for (j = 0; j < nhg->num_nh; j++) {
+ struct nh_grp_entry *nhge = &nhg->nh_entries[j];
+
+ if (nhge->nh->id == id) {
+ nh_res_bucket_set_nh(bucket, nhge);
+ found = true;
+ break;
+ }
+ }
+
+ if (!found)
+ nh_res_bucket_unset_nh(bucket);
+ }
+}
+
+static void replace_nexthop_grp_res(struct nh_group *oldg,
+ struct nh_group *newg)
+{
+ /* For NH group replacement, the new NHG might only have a stub
+ * hash table with 0 buckets, because the number of buckets was not
+ * specified. For NH removal, oldg and newg both reference the same
+ * res_table. So in any case, in the following, we want to work
+ * with oldg->res_table.
+ */
+ struct nh_res_table *old_res_table = rtnl_dereference(oldg->res_table);
+ unsigned long prev_unbalanced_since = old_res_table->unbalanced_since;
+ bool prev_has_uw = !list_empty(&old_res_table->uw_nh_entries);
+
+ nh_res_table_cancel_upkeep(old_res_table);
+ nh_res_table_migrate_buckets(old_res_table, newg);
+ nh_res_group_rebalance(newg, old_res_table);
+ if (prev_has_uw && !list_empty(&old_res_table->uw_nh_entries))
+ old_res_table->unbalanced_since = prev_unbalanced_since;
+ nh_res_table_upkeep(old_res_table, true, false);
+}
+
+static void nh_hthr_group_rebalance(struct nh_group *nhg)
+{
+ int total = 0;
+ int w = 0;
+ int i;
+
+ for (i = 0; i < nhg->num_nh; ++i)
+ total += nhg->nh_entries[i].weight;
+
+ for (i = 0; i < nhg->num_nh; ++i) {
+ struct nh_grp_entry *nhge = &nhg->nh_entries[i];
+ int upper_bound;
+
+ w += nhge->weight;
+ upper_bound = DIV_ROUND_CLOSEST_ULL((u64)w << 31, total) - 1;
+ atomic_set(&nhge->hthr.upper_bound, upper_bound);
+ }
+}
+
+static void remove_nh_grp_entry(struct net *net, struct nh_grp_entry *nhge,
+ struct nl_info *nlinfo)
+{
+ struct nh_grp_entry *nhges, *new_nhges;
+ struct nexthop *nhp = nhge->nh_parent;
+ struct netlink_ext_ack extack;
+ struct nexthop *nh = nhge->nh;
+ struct nh_group *nhg, *newg;
+ int i, j, err;
+
+ WARN_ON(!nh);
+
+ nhg = rtnl_dereference(nhp->nh_grp);
+ newg = nhg->spare;
+
+ /* last entry, keep it visible and remove the parent */
+ if (nhg->num_nh == 1) {
+ remove_nexthop(net, nhp, nlinfo);
+ return;
+ }
+
+ newg->has_v4 = false;
+ newg->is_multipath = nhg->is_multipath;
+ newg->hash_threshold = nhg->hash_threshold;
+ newg->resilient = nhg->resilient;
+ newg->fdb_nh = nhg->fdb_nh;
+ newg->num_nh = nhg->num_nh;
+
+ /* copy old entries to new except the one getting removed */
+ nhges = nhg->nh_entries;
+ new_nhges = newg->nh_entries;
+ for (i = 0, j = 0; i < nhg->num_nh; ++i) {
+ struct nh_info *nhi;
+
+ /* current nexthop getting removed */
+ if (nhg->nh_entries[i].nh == nh) {
+ newg->num_nh--;
+ continue;
+ }
+
+ nhi = rtnl_dereference(nhges[i].nh->nh_info);
+ if (nhi->family == AF_INET)
+ newg->has_v4 = true;
+
+ list_del(&nhges[i].nh_list);
+ new_nhges[j].nh_parent = nhges[i].nh_parent;
+ new_nhges[j].nh = nhges[i].nh;
+ new_nhges[j].weight = nhges[i].weight;
+ list_add(&new_nhges[j].nh_list, &new_nhges[j].nh->grp_list);
+ j++;
+ }
+
+ if (newg->hash_threshold)
+ nh_hthr_group_rebalance(newg);
+ else if (newg->resilient)
+ replace_nexthop_grp_res(nhg, newg);
+
+ rcu_assign_pointer(nhp->nh_grp, newg);
+
+ list_del(&nhge->nh_list);
+ nexthop_put(nhge->nh);
+
+ /* Removal of a NH from a resilient group is notified through
+ * bucket notifications.
+ */
+ if (newg->hash_threshold) {
+ err = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, nhp,
+ &extack);
+ if (err)
+ pr_err("%s\n", extack._msg);
+ }
+
+ if (nlinfo)
+ nexthop_notify(RTM_NEWNEXTHOP, nhp, nlinfo);
+}
+
+static void remove_nexthop_from_groups(struct net *net, struct nexthop *nh,
+ struct nl_info *nlinfo)
+{
+ struct nh_grp_entry *nhge, *tmp;
+
+ list_for_each_entry_safe(nhge, tmp, &nh->grp_list, nh_list)
+ remove_nh_grp_entry(net, nhge, nlinfo);
+
+ /* make sure all see the newly published array before releasing rtnl */
+ synchronize_net();
+}
+
+static void remove_nexthop_group(struct nexthop *nh, struct nl_info *nlinfo)
+{
+ struct nh_group *nhg = rcu_dereference_rtnl(nh->nh_grp);
+ struct nh_res_table *res_table;
+ int i, num_nh = nhg->num_nh;
+
+ for (i = 0; i < num_nh; ++i) {
+ struct nh_grp_entry *nhge = &nhg->nh_entries[i];
+
+ if (WARN_ON(!nhge->nh))
+ continue;
+
+ list_del_init(&nhge->nh_list);
+ }
+
+ if (nhg->resilient) {
+ res_table = rtnl_dereference(nhg->res_table);
+ nh_res_table_cancel_upkeep(res_table);
+ }
+}
+
+/* not called for nexthop replace */
+static void __remove_nexthop_fib(struct net *net, struct nexthop *nh)
+{
+ struct fib6_info *f6i, *tmp;
+ bool do_flush = false;
+ struct fib_info *fi;
+
+ list_for_each_entry(fi, &nh->fi_list, nh_list) {
+ fi->fib_flags |= RTNH_F_DEAD;
+ do_flush = true;
+ }
+ if (do_flush)
+ fib_flush(net);
+
+ /* ip6_del_rt removes the entry from this list hence the _safe */
+ list_for_each_entry_safe(f6i, tmp, &nh->f6i_list, nh_list) {
+ /* __ip6_del_rt does a release, so do a hold here */
+ fib6_info_hold(f6i);
+ ipv6_stub->ip6_del_rt(net, f6i,
+ !READ_ONCE(net->ipv4.sysctl_nexthop_compat_mode));
+ }
+}
+
+static void __remove_nexthop(struct net *net, struct nexthop *nh,
+ struct nl_info *nlinfo)
+{
+ __remove_nexthop_fib(net, nh);
+
+ if (nh->is_group) {
+ remove_nexthop_group(nh, nlinfo);
+ } else {
+ struct nh_info *nhi;
+
+ nhi = rtnl_dereference(nh->nh_info);
+ if (nhi->fib_nhc.nhc_dev)
+ hlist_del(&nhi->dev_hash);
+
+ remove_nexthop_from_groups(net, nh, nlinfo);
+ }
+}
+
+static void remove_nexthop(struct net *net, struct nexthop *nh,
+ struct nl_info *nlinfo)
+{
+ call_nexthop_notifiers(net, NEXTHOP_EVENT_DEL, nh, NULL);
+
+ /* remove from the tree */
+ rb_erase(&nh->rb_node, &net->nexthop.rb_root);
+
+ if (nlinfo)
+ nexthop_notify(RTM_DELNEXTHOP, nh, nlinfo);
+
+ __remove_nexthop(net, nh, nlinfo);
+ nh_base_seq_inc(net);
+
+ nexthop_put(nh);
+}
+
+/* if any FIB entries reference this nexthop, any dst entries
+ * need to be regenerated
+ */
+static void nh_rt_cache_flush(struct net *net, struct nexthop *nh,
+ struct nexthop *replaced_nh)
+{
+ struct fib6_info *f6i;
+ struct nh_group *nhg;
+ int i;
+
+ if (!list_empty(&nh->fi_list))
+ rt_cache_flush(net);
+
+ list_for_each_entry(f6i, &nh->f6i_list, nh_list)
+ ipv6_stub->fib6_update_sernum(net, f6i);
+
+ /* if an IPv6 group was replaced, we have to release all old
+ * dsts to make sure all refcounts are released
+ */
+ if (!replaced_nh->is_group)
+ return;
+
+ nhg = rtnl_dereference(replaced_nh->nh_grp);
+ for (i = 0; i < nhg->num_nh; i++) {
+ struct nh_grp_entry *nhge = &nhg->nh_entries[i];
+ struct nh_info *nhi = rtnl_dereference(nhge->nh->nh_info);
+
+ if (nhi->family == AF_INET6)
+ ipv6_stub->fib6_nh_release_dsts(&nhi->fib6_nh);
+ }
+}
+
+static int replace_nexthop_grp(struct net *net, struct nexthop *old,
+ struct nexthop *new, const struct nh_config *cfg,
+ struct netlink_ext_ack *extack)
+{
+ struct nh_res_table *tmp_table = NULL;
+ struct nh_res_table *new_res_table;
+ struct nh_res_table *old_res_table;
+ struct nh_group *oldg, *newg;
+ int i, err;
+
+ if (!new->is_group) {
+ NL_SET_ERR_MSG(extack, "Can not replace a nexthop group with a nexthop.");
+ return -EINVAL;
+ }
+
+ oldg = rtnl_dereference(old->nh_grp);
+ newg = rtnl_dereference(new->nh_grp);
+
+ if (newg->hash_threshold != oldg->hash_threshold) {
+ NL_SET_ERR_MSG(extack, "Can not replace a nexthop group with one of a different type.");
+ return -EINVAL;
+ }
+
+ if (newg->hash_threshold) {
+ err = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, new,
+ extack);
+ if (err)
+ return err;
+ } else if (newg->resilient) {
+ new_res_table = rtnl_dereference(newg->res_table);
+ old_res_table = rtnl_dereference(oldg->res_table);
+
+ /* Accept if num_nh_buckets was not given, but if it was
+ * given, demand that the value be correct.
+ */
+ if (cfg->nh_grp_res_has_num_buckets &&
+ cfg->nh_grp_res_num_buckets !=
+ old_res_table->num_nh_buckets) {
+ NL_SET_ERR_MSG(extack, "Can not change number of buckets of a resilient nexthop group.");
+ return -EINVAL;
+ }
+
+ /* Emit a pre-replace notification so that listeners could veto
+ * a potentially unsupported configuration. Otherwise,
+ * individual bucket replacement notifications would need to be
+ * vetoed, which is something that should only happen if the
+ * bucket is currently active.
+ */
+ err = call_nexthop_res_table_notifiers(net, new, extack);
+ if (err)
+ return err;
+
+ if (cfg->nh_grp_res_has_idle_timer)
+ old_res_table->idle_timer = cfg->nh_grp_res_idle_timer;
+ if (cfg->nh_grp_res_has_unbalanced_timer)
+ old_res_table->unbalanced_timer =
+ cfg->nh_grp_res_unbalanced_timer;
+
+ replace_nexthop_grp_res(oldg, newg);
+
+ tmp_table = new_res_table;
+ rcu_assign_pointer(newg->res_table, old_res_table);
+ rcu_assign_pointer(newg->spare->res_table, old_res_table);
+ }
+
+ /* update parents - used by nexthop code for cleanup */
+ for (i = 0; i < newg->num_nh; i++)
+ newg->nh_entries[i].nh_parent = old;
+
+ rcu_assign_pointer(old->nh_grp, newg);
+
+ /* Make sure concurrent readers are not using 'oldg' anymore. */
+ synchronize_net();
+
+ if (newg->resilient) {
+ rcu_assign_pointer(oldg->res_table, tmp_table);
+ rcu_assign_pointer(oldg->spare->res_table, tmp_table);
+ }
+
+ for (i = 0; i < oldg->num_nh; i++)
+ oldg->nh_entries[i].nh_parent = new;
+
+ rcu_assign_pointer(new->nh_grp, oldg);
+
+ return 0;
+}
+
+static void nh_group_v4_update(struct nh_group *nhg)
+{
+ struct nh_grp_entry *nhges;
+ bool has_v4 = false;
+ int i;
+
+ nhges = nhg->nh_entries;
+ for (i = 0; i < nhg->num_nh; i++) {
+ struct nh_info *nhi;
+
+ nhi = rtnl_dereference(nhges[i].nh->nh_info);
+ if (nhi->family == AF_INET)
+ has_v4 = true;
+ }
+ nhg->has_v4 = has_v4;
+}
+
+static int replace_nexthop_single_notify_res(struct net *net,
+ struct nh_res_table *res_table,
+ struct nexthop *old,
+ struct nh_info *oldi,
+ struct nh_info *newi,
+ struct netlink_ext_ack *extack)
+{
+ u32 nhg_id = res_table->nhg_id;
+ int err;
+ u16 i;
+
+ for (i = 0; i < res_table->num_nh_buckets; i++) {
+ struct nh_res_bucket *bucket = &res_table->nh_buckets[i];
+ struct nh_grp_entry *nhge;
+
+ nhge = rtnl_dereference(bucket->nh_entry);
+ if (nhge->nh == old) {
+ err = __call_nexthop_res_bucket_notifiers(net, nhg_id,
+ i, true,
+ oldi, newi,
+ extack);
+ if (err)
+ goto err_notify;
+ }
+ }
+
+ return 0;
+
+err_notify:
+ while (i-- > 0) {
+ struct nh_res_bucket *bucket = &res_table->nh_buckets[i];
+ struct nh_grp_entry *nhge;
+
+ nhge = rtnl_dereference(bucket->nh_entry);
+ if (nhge->nh == old)
+ __call_nexthop_res_bucket_notifiers(net, nhg_id, i,
+ true, newi, oldi,
+ extack);
+ }
+ return err;
+}
+
+static int replace_nexthop_single_notify(struct net *net,
+ struct nexthop *group_nh,
+ struct nexthop *old,
+ struct nh_info *oldi,
+ struct nh_info *newi,
+ struct netlink_ext_ack *extack)
+{
+ struct nh_group *nhg = rtnl_dereference(group_nh->nh_grp);
+ struct nh_res_table *res_table;
+
+ if (nhg->hash_threshold) {
+ return call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE,
+ group_nh, extack);
+ } else if (nhg->resilient) {
+ res_table = rtnl_dereference(nhg->res_table);
+ return replace_nexthop_single_notify_res(net, res_table,
+ old, oldi, newi,
+ extack);
+ }
+
+ return -EINVAL;
+}
+
+static int replace_nexthop_single(struct net *net, struct nexthop *old,
+ struct nexthop *new,
+ struct netlink_ext_ack *extack)
+{
+ u8 old_protocol, old_nh_flags;
+ struct nh_info *oldi, *newi;
+ struct nh_grp_entry *nhge;
+ int err;
+
+ if (new->is_group) {
+ NL_SET_ERR_MSG(extack, "Can not replace a nexthop with a nexthop group.");
+ return -EINVAL;
+ }
+
+ err = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, new, extack);
+ if (err)
+ return err;
+
+ /* Hardware flags were set on 'old' as 'new' is not in the red-black
+ * tree. Therefore, inherit the flags from 'old' to 'new'.
+ */
+ new->nh_flags |= old->nh_flags & (RTNH_F_OFFLOAD | RTNH_F_TRAP);
+
+ oldi = rtnl_dereference(old->nh_info);
+ newi = rtnl_dereference(new->nh_info);
+
+ newi->nh_parent = old;
+ oldi->nh_parent = new;
+
+ old_protocol = old->protocol;
+ old_nh_flags = old->nh_flags;
+
+ old->protocol = new->protocol;
+ old->nh_flags = new->nh_flags;
+
+ rcu_assign_pointer(old->nh_info, newi);
+ rcu_assign_pointer(new->nh_info, oldi);
+
+ /* Send a replace notification for all the groups using the nexthop. */
+ list_for_each_entry(nhge, &old->grp_list, nh_list) {
+ struct nexthop *nhp = nhge->nh_parent;
+
+ err = replace_nexthop_single_notify(net, nhp, old, oldi, newi,
+ extack);
+ if (err)
+ goto err_notify;
+ }
+
+ /* When replacing an IPv4 nexthop with an IPv6 nexthop, potentially
+ * update IPv4 indication in all the groups using the nexthop.
+ */
+ if (oldi->family == AF_INET && newi->family == AF_INET6) {
+ list_for_each_entry(nhge, &old->grp_list, nh_list) {
+ struct nexthop *nhp = nhge->nh_parent;
+ struct nh_group *nhg;
+
+ nhg = rtnl_dereference(nhp->nh_grp);
+ nh_group_v4_update(nhg);
+ }
+ }
+
+ return 0;
+
+err_notify:
+ rcu_assign_pointer(new->nh_info, newi);
+ rcu_assign_pointer(old->nh_info, oldi);
+ old->nh_flags = old_nh_flags;
+ old->protocol = old_protocol;
+ oldi->nh_parent = old;
+ newi->nh_parent = new;
+ list_for_each_entry_continue_reverse(nhge, &old->grp_list, nh_list) {
+ struct nexthop *nhp = nhge->nh_parent;
+
+ replace_nexthop_single_notify(net, nhp, old, newi, oldi, NULL);
+ }
+ call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, old, extack);
+ return err;
+}
+
+static void __nexthop_replace_notify(struct net *net, struct nexthop *nh,
+ struct nl_info *info)
+{
+ struct fib6_info *f6i;
+
+ if (!list_empty(&nh->fi_list)) {
+ struct fib_info *fi;
+
+ /* expectation is a few fib_info per nexthop and then
+ * a lot of routes per fib_info. So mark the fib_info
+ * and then walk the fib tables once
+ */
+ list_for_each_entry(fi, &nh->fi_list, nh_list)
+ fi->nh_updated = true;
+
+ fib_info_notify_update(net, info);
+
+ list_for_each_entry(fi, &nh->fi_list, nh_list)
+ fi->nh_updated = false;
+ }
+
+ list_for_each_entry(f6i, &nh->f6i_list, nh_list)
+ ipv6_stub->fib6_rt_update(net, f6i, info);
+}
+
+/* send RTM_NEWROUTE with REPLACE flag set for all FIB entries
+ * linked to this nexthop and for all groups that the nexthop
+ * is a member of
+ */
+static void nexthop_replace_notify(struct net *net, struct nexthop *nh,
+ struct nl_info *info)
+{
+ struct nh_grp_entry *nhge;
+
+ __nexthop_replace_notify(net, nh, info);
+
+ list_for_each_entry(nhge, &nh->grp_list, nh_list)
+ __nexthop_replace_notify(net, nhge->nh_parent, info);
+}
+
+static int replace_nexthop(struct net *net, struct nexthop *old,
+ struct nexthop *new, const struct nh_config *cfg,
+ struct netlink_ext_ack *extack)
+{
+ bool new_is_reject = false;
+ struct nh_grp_entry *nhge;
+ int err;
+
+ /* check that existing FIB entries are ok with the
+ * new nexthop definition
+ */
+ err = fib_check_nh_list(old, new, extack);
+ if (err)
+ return err;
+
+ err = fib6_check_nh_list(old, new, extack);
+ if (err)
+ return err;
+
+ if (!new->is_group) {
+ struct nh_info *nhi = rtnl_dereference(new->nh_info);
+
+ new_is_reject = nhi->reject_nh;
+ }
+
+ list_for_each_entry(nhge, &old->grp_list, nh_list) {
+ /* if new nexthop is a blackhole, any groups using this
+ * nexthop cannot have more than 1 path
+ */
+ if (new_is_reject &&
+ nexthop_num_path(nhge->nh_parent) > 1) {
+ NL_SET_ERR_MSG(extack, "Blackhole nexthop can not be a member of a group with more than one path");
+ return -EINVAL;
+ }
+
+ err = fib_check_nh_list(nhge->nh_parent, new, extack);
+ if (err)
+ return err;
+
+ err = fib6_check_nh_list(nhge->nh_parent, new, extack);
+ if (err)
+ return err;
+ }
+
+ if (old->is_group)
+ err = replace_nexthop_grp(net, old, new, cfg, extack);
+ else
+ err = replace_nexthop_single(net, old, new, extack);
+
+ if (!err) {
+ nh_rt_cache_flush(net, old, new);
+
+ __remove_nexthop(net, new, NULL);
+ nexthop_put(new);
+ }
+
+ return err;
+}
+
+/* called with rtnl_lock held */
+static int insert_nexthop(struct net *net, struct nexthop *new_nh,
+ struct nh_config *cfg, struct netlink_ext_ack *extack)
+{
+ struct rb_node **pp, *parent = NULL, *next;
+ struct rb_root *root = &net->nexthop.rb_root;
+ bool replace = !!(cfg->nlflags & NLM_F_REPLACE);
+ bool create = !!(cfg->nlflags & NLM_F_CREATE);
+ u32 new_id = new_nh->id;
+ int replace_notify = 0;
+ int rc = -EEXIST;
+
+ pp = &root->rb_node;
+ while (1) {
+ struct nexthop *nh;
+
+ next = *pp;
+ if (!next)
+ break;
+
+ parent = next;
+
+ nh = rb_entry(parent, struct nexthop, rb_node);
+ if (new_id < nh->id) {
+ pp = &next->rb_left;
+ } else if (new_id > nh->id) {
+ pp = &next->rb_right;
+ } else if (replace) {
+ rc = replace_nexthop(net, nh, new_nh, cfg, extack);
+ if (!rc) {
+ new_nh = nh; /* send notification with old nh */
+ replace_notify = 1;
+ }
+ goto out;
+ } else {
+ /* id already exists and not a replace */
+ goto out;
+ }
+ }
+
+ if (replace && !create) {
+ NL_SET_ERR_MSG(extack, "Replace specified without create and no entry exists");
+ rc = -ENOENT;
+ goto out;
+ }
+
+ if (new_nh->is_group) {
+ struct nh_group *nhg = rtnl_dereference(new_nh->nh_grp);
+ struct nh_res_table *res_table;
+
+ if (nhg->resilient) {
+ res_table = rtnl_dereference(nhg->res_table);
+
+ /* Not passing the number of buckets is OK when
+ * replacing, but not when creating a new group.
+ */
+ if (!cfg->nh_grp_res_has_num_buckets) {
+ NL_SET_ERR_MSG(extack, "Number of buckets not specified for nexthop group insertion");
+ rc = -EINVAL;
+ goto out;
+ }
+
+ nh_res_group_rebalance(nhg, res_table);
+
+ /* Do not send bucket notifications, we do full
+ * notification below.
+ */
+ nh_res_table_upkeep(res_table, false, false);
+ }
+ }
+
+ rb_link_node_rcu(&new_nh->rb_node, parent, pp);
+ rb_insert_color(&new_nh->rb_node, root);
+
+ /* The initial insertion is a full notification for hash-threshold as
+ * well as resilient groups.
+ */
+ rc = call_nexthop_notifiers(net, NEXTHOP_EVENT_REPLACE, new_nh, extack);
+ if (rc)
+ rb_erase(&new_nh->rb_node, &net->nexthop.rb_root);
+
+out:
+ if (!rc) {
+ nh_base_seq_inc(net);
+ nexthop_notify(RTM_NEWNEXTHOP, new_nh, &cfg->nlinfo);
+ if (replace_notify &&
+ READ_ONCE(net->ipv4.sysctl_nexthop_compat_mode))
+ nexthop_replace_notify(net, new_nh, &cfg->nlinfo);
+ }
+
+ return rc;
+}
+
+/* rtnl */
+/* remove all nexthops tied to a device being deleted */
+static void nexthop_flush_dev(struct net_device *dev, unsigned long event)
+{
+ unsigned int hash = nh_dev_hashfn(dev->ifindex);
+ struct net *net = dev_net(dev);
+ struct hlist_head *head = &net->nexthop.devhash[hash];
+ struct hlist_node *n;
+ struct nh_info *nhi;
+
+ hlist_for_each_entry_safe(nhi, n, head, dev_hash) {
+ if (nhi->fib_nhc.nhc_dev != dev)
+ continue;
+
+ if (nhi->reject_nh &&
+ (event == NETDEV_DOWN || event == NETDEV_CHANGE))
+ continue;
+
+ remove_nexthop(net, nhi->nh_parent, NULL);
+ }
+}
+
+/* rtnl; called when net namespace is deleted */
+static void flush_all_nexthops(struct net *net)
+{
+ struct rb_root *root = &net->nexthop.rb_root;
+ struct rb_node *node;
+ struct nexthop *nh;
+
+ while ((node = rb_first(root))) {
+ nh = rb_entry(node, struct nexthop, rb_node);
+ remove_nexthop(net, nh, NULL);
+ cond_resched();
+ }
+}
+
+static struct nexthop *nexthop_create_group(struct net *net,
+ struct nh_config *cfg)
+{
+ struct nlattr *grps_attr = cfg->nh_grp;
+ struct nexthop_grp *entry = nla_data(grps_attr);
+ u16 num_nh = nla_len(grps_attr) / sizeof(*entry);
+ struct nh_group *nhg;
+ struct nexthop *nh;
+ int err;
+ int i;
+
+ if (WARN_ON(!num_nh))
+ return ERR_PTR(-EINVAL);
+
+ nh = nexthop_alloc();
+ if (!nh)
+ return ERR_PTR(-ENOMEM);
+
+ nh->is_group = 1;
+
+ nhg = nexthop_grp_alloc(num_nh);
+ if (!nhg) {
+ kfree(nh);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ /* spare group used for removals */
+ nhg->spare = nexthop_grp_alloc(num_nh);
+ if (!nhg->spare) {
+ kfree(nhg);
+ kfree(nh);
+ return ERR_PTR(-ENOMEM);
+ }
+ nhg->spare->spare = nhg;
+
+ for (i = 0; i < nhg->num_nh; ++i) {
+ struct nexthop *nhe;
+ struct nh_info *nhi;
+
+ nhe = nexthop_find_by_id(net, entry[i].id);
+ if (!nexthop_get(nhe)) {
+ err = -ENOENT;
+ goto out_no_nh;
+ }
+
+ nhi = rtnl_dereference(nhe->nh_info);
+ if (nhi->family == AF_INET)
+ nhg->has_v4 = true;
+
+ nhg->nh_entries[i].nh = nhe;
+ nhg->nh_entries[i].weight = entry[i].weight + 1;
+ list_add(&nhg->nh_entries[i].nh_list, &nhe->grp_list);
+ nhg->nh_entries[i].nh_parent = nh;
+ }
+
+ if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_MPATH) {
+ nhg->hash_threshold = 1;
+ nhg->is_multipath = true;
+ } else if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_RES) {
+ struct nh_res_table *res_table;
+
+ res_table = nexthop_res_table_alloc(net, cfg->nh_id, cfg);
+ if (!res_table) {
+ err = -ENOMEM;
+ goto out_no_nh;
+ }
+
+ rcu_assign_pointer(nhg->spare->res_table, res_table);
+ rcu_assign_pointer(nhg->res_table, res_table);
+ nhg->resilient = true;
+ nhg->is_multipath = true;
+ }
+
+ WARN_ON_ONCE(nhg->hash_threshold + nhg->resilient != 1);
+
+ if (nhg->hash_threshold)
+ nh_hthr_group_rebalance(nhg);
+
+ if (cfg->nh_fdb)
+ nhg->fdb_nh = 1;
+
+ rcu_assign_pointer(nh->nh_grp, nhg);
+
+ return nh;
+
+out_no_nh:
+ for (i--; i >= 0; --i) {
+ list_del(&nhg->nh_entries[i].nh_list);
+ nexthop_put(nhg->nh_entries[i].nh);
+ }
+
+ kfree(nhg->spare);
+ kfree(nhg);
+ kfree(nh);
+
+ return ERR_PTR(err);
+}
+
+static int nh_create_ipv4(struct net *net, struct nexthop *nh,
+ struct nh_info *nhi, struct nh_config *cfg,
+ struct netlink_ext_ack *extack)
+{
+ struct fib_nh *fib_nh = &nhi->fib_nh;
+ struct fib_config fib_cfg = {
+ .fc_oif = cfg->nh_ifindex,
+ .fc_gw4 = cfg->gw.ipv4,
+ .fc_gw_family = cfg->gw.ipv4 ? AF_INET : 0,
+ .fc_flags = cfg->nh_flags,
+ .fc_nlinfo = cfg->nlinfo,
+ .fc_encap = cfg->nh_encap,
+ .fc_encap_type = cfg->nh_encap_type,
+ };
+ u32 tb_id = (cfg->dev ? l3mdev_fib_table(cfg->dev) : RT_TABLE_MAIN);
+ int err;
+
+ err = fib_nh_init(net, fib_nh, &fib_cfg, 1, extack);
+ if (err) {
+ fib_nh_release(net, fib_nh);
+ goto out;
+ }
+
+ if (nhi->fdb_nh)
+ goto out;
+
+ /* sets nh_dev if successful */
+ err = fib_check_nh(net, fib_nh, tb_id, 0, extack);
+ if (!err) {
+ nh->nh_flags = fib_nh->fib_nh_flags;
+ fib_info_update_nhc_saddr(net, &fib_nh->nh_common,
+ !fib_nh->fib_nh_scope ? 0 : fib_nh->fib_nh_scope - 1);
+ } else {
+ fib_nh_release(net, fib_nh);
+ }
+out:
+ return err;
+}
+
+static int nh_create_ipv6(struct net *net, struct nexthop *nh,
+ struct nh_info *nhi, struct nh_config *cfg,
+ struct netlink_ext_ack *extack)
+{
+ struct fib6_nh *fib6_nh = &nhi->fib6_nh;
+ struct fib6_config fib6_cfg = {
+ .fc_table = l3mdev_fib_table(cfg->dev),
+ .fc_ifindex = cfg->nh_ifindex,
+ .fc_gateway = cfg->gw.ipv6,
+ .fc_flags = cfg->nh_flags,
+ .fc_nlinfo = cfg->nlinfo,
+ .fc_encap = cfg->nh_encap,
+ .fc_encap_type = cfg->nh_encap_type,
+ .fc_is_fdb = cfg->nh_fdb,
+ };
+ int err;
+
+ if (!ipv6_addr_any(&cfg->gw.ipv6))
+ fib6_cfg.fc_flags |= RTF_GATEWAY;
+
+ /* sets nh_dev if successful */
+ err = ipv6_stub->fib6_nh_init(net, fib6_nh, &fib6_cfg, GFP_KERNEL,
+ extack);
+ if (err) {
+ /* IPv6 is not enabled, don't call fib6_nh_release */
+ if (err == -EAFNOSUPPORT)
+ goto out;
+ ipv6_stub->fib6_nh_release(fib6_nh);
+ } else {
+ nh->nh_flags = fib6_nh->fib_nh_flags;
+ }
+out:
+ return err;
+}
+
+static struct nexthop *nexthop_create(struct net *net, struct nh_config *cfg,
+ struct netlink_ext_ack *extack)
+{
+ struct nh_info *nhi;
+ struct nexthop *nh;
+ int err = 0;
+
+ nh = nexthop_alloc();
+ if (!nh)
+ return ERR_PTR(-ENOMEM);
+
+ nhi = kzalloc(sizeof(*nhi), GFP_KERNEL);
+ if (!nhi) {
+ kfree(nh);
+ return ERR_PTR(-ENOMEM);
+ }
+
+ nh->nh_flags = cfg->nh_flags;
+ nh->net = net;
+
+ nhi->nh_parent = nh;
+ nhi->family = cfg->nh_family;
+ nhi->fib_nhc.nhc_scope = RT_SCOPE_LINK;
+
+ if (cfg->nh_fdb)
+ nhi->fdb_nh = 1;
+
+ if (cfg->nh_blackhole) {
+ nhi->reject_nh = 1;
+ cfg->nh_ifindex = net->loopback_dev->ifindex;
+ }
+
+ switch (cfg->nh_family) {
+ case AF_INET:
+ err = nh_create_ipv4(net, nh, nhi, cfg, extack);
+ break;
+ case AF_INET6:
+ err = nh_create_ipv6(net, nh, nhi, cfg, extack);
+ break;
+ }
+
+ if (err) {
+ kfree(nhi);
+ kfree(nh);
+ return ERR_PTR(err);
+ }
+
+ /* add the entry to the device based hash */
+ if (!nhi->fdb_nh)
+ nexthop_devhash_add(net, nhi);
+
+ rcu_assign_pointer(nh->nh_info, nhi);
+
+ return nh;
+}
+
+/* called with rtnl lock held */
+static struct nexthop *nexthop_add(struct net *net, struct nh_config *cfg,
+ struct netlink_ext_ack *extack)
+{
+ struct nexthop *nh;
+ int err;
+
+ if (cfg->nlflags & NLM_F_REPLACE && !cfg->nh_id) {
+ NL_SET_ERR_MSG(extack, "Replace requires nexthop id");
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (!cfg->nh_id) {
+ cfg->nh_id = nh_find_unused_id(net);
+ if (!cfg->nh_id) {
+ NL_SET_ERR_MSG(extack, "No unused id");
+ return ERR_PTR(-EINVAL);
+ }
+ }
+
+ if (cfg->nh_grp)
+ nh = nexthop_create_group(net, cfg);
+ else
+ nh = nexthop_create(net, cfg, extack);
+
+ if (IS_ERR(nh))
+ return nh;
+
+ refcount_set(&nh->refcnt, 1);
+ nh->id = cfg->nh_id;
+ nh->protocol = cfg->nh_protocol;
+ nh->net = net;
+
+ err = insert_nexthop(net, nh, cfg, extack);
+ if (err) {
+ __remove_nexthop(net, nh, NULL);
+ nexthop_put(nh);
+ nh = ERR_PTR(err);
+ }
+
+ return nh;
+}
+
+static int rtm_nh_get_timer(struct nlattr *attr, unsigned long fallback,
+ unsigned long *timer_p, bool *has_p,
+ struct netlink_ext_ack *extack)
+{
+ unsigned long timer;
+ u32 value;
+
+ if (!attr) {
+ *timer_p = fallback;
+ *has_p = false;
+ return 0;
+ }
+
+ value = nla_get_u32(attr);
+ timer = clock_t_to_jiffies(value);
+ if (timer == ~0UL) {
+ NL_SET_ERR_MSG(extack, "Timer value too large");
+ return -EINVAL;
+ }
+
+ *timer_p = timer;
+ *has_p = true;
+ return 0;
+}
+
+static int rtm_to_nh_config_grp_res(struct nlattr *res, struct nh_config *cfg,
+ struct netlink_ext_ack *extack)
+{
+ struct nlattr *tb[ARRAY_SIZE(rtm_nh_res_policy_new)] = {};
+ int err;
+
+ if (res) {
+ err = nla_parse_nested(tb,
+ ARRAY_SIZE(rtm_nh_res_policy_new) - 1,
+ res, rtm_nh_res_policy_new, extack);
+ if (err < 0)
+ return err;
+ }
+
+ if (tb[NHA_RES_GROUP_BUCKETS]) {
+ cfg->nh_grp_res_num_buckets =
+ nla_get_u16(tb[NHA_RES_GROUP_BUCKETS]);
+ cfg->nh_grp_res_has_num_buckets = true;
+ if (!cfg->nh_grp_res_num_buckets) {
+ NL_SET_ERR_MSG(extack, "Number of buckets needs to be non-0");
+ return -EINVAL;
+ }
+ }
+
+ err = rtm_nh_get_timer(tb[NHA_RES_GROUP_IDLE_TIMER],
+ NH_RES_DEFAULT_IDLE_TIMER,
+ &cfg->nh_grp_res_idle_timer,
+ &cfg->nh_grp_res_has_idle_timer,
+ extack);
+ if (err)
+ return err;
+
+ return rtm_nh_get_timer(tb[NHA_RES_GROUP_UNBALANCED_TIMER],
+ NH_RES_DEFAULT_UNBALANCED_TIMER,
+ &cfg->nh_grp_res_unbalanced_timer,
+ &cfg->nh_grp_res_has_unbalanced_timer,
+ extack);
+}
+
+static int rtm_to_nh_config(struct net *net, struct sk_buff *skb,
+ struct nlmsghdr *nlh, struct nh_config *cfg,
+ struct netlink_ext_ack *extack)
+{
+ struct nhmsg *nhm = nlmsg_data(nlh);
+ struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_new)];
+ int err;
+
+ err = nlmsg_parse(nlh, sizeof(*nhm), tb,
+ ARRAY_SIZE(rtm_nh_policy_new) - 1,
+ rtm_nh_policy_new, extack);
+ if (err < 0)
+ return err;
+
+ err = -EINVAL;
+ if (nhm->resvd || nhm->nh_scope) {
+ NL_SET_ERR_MSG(extack, "Invalid values in ancillary header");
+ goto out;
+ }
+ if (nhm->nh_flags & ~NEXTHOP_VALID_USER_FLAGS) {
+ NL_SET_ERR_MSG(extack, "Invalid nexthop flags in ancillary header");
+ goto out;
+ }
+
+ switch (nhm->nh_family) {
+ case AF_INET:
+ case AF_INET6:
+ break;
+ case AF_UNSPEC:
+ if (tb[NHA_GROUP])
+ break;
+ fallthrough;
+ default:
+ NL_SET_ERR_MSG(extack, "Invalid address family");
+ goto out;
+ }
+
+ memset(cfg, 0, sizeof(*cfg));
+ cfg->nlflags = nlh->nlmsg_flags;
+ cfg->nlinfo.portid = NETLINK_CB(skb).portid;
+ cfg->nlinfo.nlh = nlh;
+ cfg->nlinfo.nl_net = net;
+
+ cfg->nh_family = nhm->nh_family;
+ cfg->nh_protocol = nhm->nh_protocol;
+ cfg->nh_flags = nhm->nh_flags;
+
+ if (tb[NHA_ID])
+ cfg->nh_id = nla_get_u32(tb[NHA_ID]);
+
+ if (tb[NHA_FDB]) {
+ if (tb[NHA_OIF] || tb[NHA_BLACKHOLE] ||
+ tb[NHA_ENCAP] || tb[NHA_ENCAP_TYPE]) {
+ NL_SET_ERR_MSG(extack, "Fdb attribute can not be used with encap, oif or blackhole");
+ goto out;
+ }
+ if (nhm->nh_flags) {
+ NL_SET_ERR_MSG(extack, "Unsupported nexthop flags in ancillary header");
+ goto out;
+ }
+ cfg->nh_fdb = nla_get_flag(tb[NHA_FDB]);
+ }
+
+ if (tb[NHA_GROUP]) {
+ if (nhm->nh_family != AF_UNSPEC) {
+ NL_SET_ERR_MSG(extack, "Invalid family for group");
+ goto out;
+ }
+ cfg->nh_grp = tb[NHA_GROUP];
+
+ cfg->nh_grp_type = NEXTHOP_GRP_TYPE_MPATH;
+ if (tb[NHA_GROUP_TYPE])
+ cfg->nh_grp_type = nla_get_u16(tb[NHA_GROUP_TYPE]);
+
+ if (cfg->nh_grp_type > NEXTHOP_GRP_TYPE_MAX) {
+ NL_SET_ERR_MSG(extack, "Invalid group type");
+ goto out;
+ }
+ err = nh_check_attr_group(net, tb, ARRAY_SIZE(tb),
+ cfg->nh_grp_type, extack);
+ if (err)
+ goto out;
+
+ if (cfg->nh_grp_type == NEXTHOP_GRP_TYPE_RES)
+ err = rtm_to_nh_config_grp_res(tb[NHA_RES_GROUP],
+ cfg, extack);
+
+ /* no other attributes should be set */
+ goto out;
+ }
+
+ if (tb[NHA_BLACKHOLE]) {
+ if (tb[NHA_GATEWAY] || tb[NHA_OIF] ||
+ tb[NHA_ENCAP] || tb[NHA_ENCAP_TYPE] || tb[NHA_FDB]) {
+ NL_SET_ERR_MSG(extack, "Blackhole attribute can not be used with gateway, oif, encap or fdb");
+ goto out;
+ }
+
+ cfg->nh_blackhole = 1;
+ err = 0;
+ goto out;
+ }
+
+ if (!cfg->nh_fdb && !tb[NHA_OIF]) {
+ NL_SET_ERR_MSG(extack, "Device attribute required for non-blackhole and non-fdb nexthops");
+ goto out;
+ }
+
+ if (!cfg->nh_fdb && tb[NHA_OIF]) {
+ cfg->nh_ifindex = nla_get_u32(tb[NHA_OIF]);
+ if (cfg->nh_ifindex)
+ cfg->dev = __dev_get_by_index(net, cfg->nh_ifindex);
+
+ if (!cfg->dev) {
+ NL_SET_ERR_MSG(extack, "Invalid device index");
+ goto out;
+ } else if (!(cfg->dev->flags & IFF_UP)) {
+ NL_SET_ERR_MSG(extack, "Nexthop device is not up");
+ err = -ENETDOWN;
+ goto out;
+ } else if (!netif_carrier_ok(cfg->dev)) {
+ NL_SET_ERR_MSG(extack, "Carrier for nexthop device is down");
+ err = -ENETDOWN;
+ goto out;
+ }
+ }
+
+ err = -EINVAL;
+ if (tb[NHA_GATEWAY]) {
+ struct nlattr *gwa = tb[NHA_GATEWAY];
+
+ switch (cfg->nh_family) {
+ case AF_INET:
+ if (nla_len(gwa) != sizeof(u32)) {
+ NL_SET_ERR_MSG(extack, "Invalid gateway");
+ goto out;
+ }
+ cfg->gw.ipv4 = nla_get_be32(gwa);
+ break;
+ case AF_INET6:
+ if (nla_len(gwa) != sizeof(struct in6_addr)) {
+ NL_SET_ERR_MSG(extack, "Invalid gateway");
+ goto out;
+ }
+ cfg->gw.ipv6 = nla_get_in6_addr(gwa);
+ break;
+ default:
+ NL_SET_ERR_MSG(extack,
+ "Unknown address family for gateway");
+ goto out;
+ }
+ } else {
+ /* device only nexthop (no gateway) */
+ if (cfg->nh_flags & RTNH_F_ONLINK) {
+ NL_SET_ERR_MSG(extack,
+ "ONLINK flag can not be set for nexthop without a gateway");
+ goto out;
+ }
+ }
+
+ if (tb[NHA_ENCAP]) {
+ cfg->nh_encap = tb[NHA_ENCAP];
+
+ if (!tb[NHA_ENCAP_TYPE]) {
+ NL_SET_ERR_MSG(extack, "LWT encapsulation type is missing");
+ goto out;
+ }
+
+ cfg->nh_encap_type = nla_get_u16(tb[NHA_ENCAP_TYPE]);
+ err = lwtunnel_valid_encap_type(cfg->nh_encap_type, extack);
+ if (err < 0)
+ goto out;
+
+ } else if (tb[NHA_ENCAP_TYPE]) {
+ NL_SET_ERR_MSG(extack, "LWT encapsulation attribute is missing");
+ goto out;
+ }
+
+
+ err = 0;
+out:
+ return err;
+}
+
+/* rtnl */
+static int rtm_new_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh,
+ struct netlink_ext_ack *extack)
+{
+ struct net *net = sock_net(skb->sk);
+ struct nh_config cfg;
+ struct nexthop *nh;
+ int err;
+
+ err = rtm_to_nh_config(net, skb, nlh, &cfg, extack);
+ if (!err) {
+ nh = nexthop_add(net, &cfg, extack);
+ if (IS_ERR(nh))
+ err = PTR_ERR(nh);
+ }
+
+ return err;
+}
+
+static int __nh_valid_get_del_req(const struct nlmsghdr *nlh,
+ struct nlattr **tb, u32 *id,
+ struct netlink_ext_ack *extack)
+{
+ struct nhmsg *nhm = nlmsg_data(nlh);
+
+ if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) {
+ NL_SET_ERR_MSG(extack, "Invalid values in header");
+ return -EINVAL;
+ }
+
+ if (!tb[NHA_ID]) {
+ NL_SET_ERR_MSG(extack, "Nexthop id is missing");
+ return -EINVAL;
+ }
+
+ *id = nla_get_u32(tb[NHA_ID]);
+ if (!(*id)) {
+ NL_SET_ERR_MSG(extack, "Invalid nexthop id");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int nh_valid_get_del_req(const struct nlmsghdr *nlh, u32 *id,
+ struct netlink_ext_ack *extack)
+{
+ struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_get)];
+ int err;
+
+ err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb,
+ ARRAY_SIZE(rtm_nh_policy_get) - 1,
+ rtm_nh_policy_get, extack);
+ if (err < 0)
+ return err;
+
+ return __nh_valid_get_del_req(nlh, tb, id, extack);
+}
+
+/* rtnl */
+static int rtm_del_nexthop(struct sk_buff *skb, struct nlmsghdr *nlh,
+ struct netlink_ext_ack *extack)
+{
+ struct net *net = sock_net(skb->sk);
+ struct nl_info nlinfo = {
+ .nlh = nlh,
+ .nl_net = net,
+ .portid = NETLINK_CB(skb).portid,
+ };
+ struct nexthop *nh;
+ int err;
+ u32 id;
+
+ err = nh_valid_get_del_req(nlh, &id, extack);
+ if (err)
+ return err;
+
+ nh = nexthop_find_by_id(net, id);
+ if (!nh)
+ return -ENOENT;
+
+ remove_nexthop(net, nh, &nlinfo);
+
+ return 0;
+}
+
+/* rtnl */
+static int rtm_get_nexthop(struct sk_buff *in_skb, struct nlmsghdr *nlh,
+ struct netlink_ext_ack *extack)
+{
+ struct net *net = sock_net(in_skb->sk);
+ struct sk_buff *skb = NULL;
+ struct nexthop *nh;
+ int err;
+ u32 id;
+
+ err = nh_valid_get_del_req(nlh, &id, extack);
+ if (err)
+ return err;
+
+ err = -ENOBUFS;
+ skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
+ if (!skb)
+ goto out;
+
+ err = -ENOENT;
+ nh = nexthop_find_by_id(net, id);
+ if (!nh)
+ goto errout_free;
+
+ err = nh_fill_node(skb, nh, RTM_NEWNEXTHOP, NETLINK_CB(in_skb).portid,
+ nlh->nlmsg_seq, 0);
+ if (err < 0) {
+ WARN_ON(err == -EMSGSIZE);
+ goto errout_free;
+ }
+
+ err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
+out:
+ return err;
+errout_free:
+ kfree_skb(skb);
+ goto out;
+}
+
+struct nh_dump_filter {
+ u32 nh_id;
+ int dev_idx;
+ int master_idx;
+ bool group_filter;
+ bool fdb_filter;
+ u32 res_bucket_nh_id;
+};
+
+static bool nh_dump_filtered(struct nexthop *nh,
+ struct nh_dump_filter *filter, u8 family)
+{
+ const struct net_device *dev;
+ const struct nh_info *nhi;
+
+ if (filter->group_filter && !nh->is_group)
+ return true;
+
+ if (!filter->dev_idx && !filter->master_idx && !family)
+ return false;
+
+ if (nh->is_group)
+ return true;
+
+ nhi = rtnl_dereference(nh->nh_info);
+ if (family && nhi->family != family)
+ return true;
+
+ dev = nhi->fib_nhc.nhc_dev;
+ if (filter->dev_idx && (!dev || dev->ifindex != filter->dev_idx))
+ return true;
+
+ if (filter->master_idx) {
+ struct net_device *master;
+
+ if (!dev)
+ return true;
+
+ master = netdev_master_upper_dev_get((struct net_device *)dev);
+ if (!master || master->ifindex != filter->master_idx)
+ return true;
+ }
+
+ return false;
+}
+
+static int __nh_valid_dump_req(const struct nlmsghdr *nlh, struct nlattr **tb,
+ struct nh_dump_filter *filter,
+ struct netlink_ext_ack *extack)
+{
+ struct nhmsg *nhm;
+ u32 idx;
+
+ if (tb[NHA_OIF]) {
+ idx = nla_get_u32(tb[NHA_OIF]);
+ if (idx > INT_MAX) {
+ NL_SET_ERR_MSG(extack, "Invalid device index");
+ return -EINVAL;
+ }
+ filter->dev_idx = idx;
+ }
+ if (tb[NHA_MASTER]) {
+ idx = nla_get_u32(tb[NHA_MASTER]);
+ if (idx > INT_MAX) {
+ NL_SET_ERR_MSG(extack, "Invalid master device index");
+ return -EINVAL;
+ }
+ filter->master_idx = idx;
+ }
+ filter->group_filter = nla_get_flag(tb[NHA_GROUPS]);
+ filter->fdb_filter = nla_get_flag(tb[NHA_FDB]);
+
+ nhm = nlmsg_data(nlh);
+ if (nhm->nh_protocol || nhm->resvd || nhm->nh_scope || nhm->nh_flags) {
+ NL_SET_ERR_MSG(extack, "Invalid values in header for nexthop dump request");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int nh_valid_dump_req(const struct nlmsghdr *nlh,
+ struct nh_dump_filter *filter,
+ struct netlink_callback *cb)
+{
+ struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_dump)];
+ int err;
+
+ err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb,
+ ARRAY_SIZE(rtm_nh_policy_dump) - 1,
+ rtm_nh_policy_dump, cb->extack);
+ if (err < 0)
+ return err;
+
+ return __nh_valid_dump_req(nlh, tb, filter, cb->extack);
+}
+
+struct rtm_dump_nh_ctx {
+ u32 idx;
+};
+
+static struct rtm_dump_nh_ctx *
+rtm_dump_nh_ctx(struct netlink_callback *cb)
+{
+ struct rtm_dump_nh_ctx *ctx = (void *)cb->ctx;
+
+ BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx));
+ return ctx;
+}
+
+static int rtm_dump_walk_nexthops(struct sk_buff *skb,
+ struct netlink_callback *cb,
+ struct rb_root *root,
+ struct rtm_dump_nh_ctx *ctx,
+ int (*nh_cb)(struct sk_buff *skb,
+ struct netlink_callback *cb,
+ struct nexthop *nh, void *data),
+ void *data)
+{
+ struct rb_node *node;
+ int s_idx;
+ int err;
+
+ s_idx = ctx->idx;
+ for (node = rb_first(root); node; node = rb_next(node)) {
+ struct nexthop *nh;
+
+ nh = rb_entry(node, struct nexthop, rb_node);
+ if (nh->id < s_idx)
+ continue;
+
+ ctx->idx = nh->id;
+ err = nh_cb(skb, cb, nh, data);
+ if (err)
+ return err;
+ }
+
+ ctx->idx++;
+ return 0;
+}
+
+static int rtm_dump_nexthop_cb(struct sk_buff *skb, struct netlink_callback *cb,
+ struct nexthop *nh, void *data)
+{
+ struct nhmsg *nhm = nlmsg_data(cb->nlh);
+ struct nh_dump_filter *filter = data;
+
+ if (nh_dump_filtered(nh, filter, nhm->nh_family))
+ return 0;
+
+ return nh_fill_node(skb, nh, RTM_NEWNEXTHOP,
+ NETLINK_CB(cb->skb).portid,
+ cb->nlh->nlmsg_seq, NLM_F_MULTI);
+}
+
+/* rtnl */
+static int rtm_dump_nexthop(struct sk_buff *skb, struct netlink_callback *cb)
+{
+ struct rtm_dump_nh_ctx *ctx = rtm_dump_nh_ctx(cb);
+ struct net *net = sock_net(skb->sk);
+ struct rb_root *root = &net->nexthop.rb_root;
+ struct nh_dump_filter filter = {};
+ int err;
+
+ err = nh_valid_dump_req(cb->nlh, &filter, cb);
+ if (err < 0)
+ return err;
+
+ err = rtm_dump_walk_nexthops(skb, cb, root, ctx,
+ &rtm_dump_nexthop_cb, &filter);
+ if (err < 0) {
+ if (likely(skb->len))
+ err = skb->len;
+ }
+
+ cb->seq = net->nexthop.seq;
+ nl_dump_check_consistent(cb, nlmsg_hdr(skb));
+ return err;
+}
+
+static struct nexthop *
+nexthop_find_group_resilient(struct net *net, u32 id,
+ struct netlink_ext_ack *extack)
+{
+ struct nh_group *nhg;
+ struct nexthop *nh;
+
+ nh = nexthop_find_by_id(net, id);
+ if (!nh)
+ return ERR_PTR(-ENOENT);
+
+ if (!nh->is_group) {
+ NL_SET_ERR_MSG(extack, "Not a nexthop group");
+ return ERR_PTR(-EINVAL);
+ }
+
+ nhg = rtnl_dereference(nh->nh_grp);
+ if (!nhg->resilient) {
+ NL_SET_ERR_MSG(extack, "Nexthop group not of type resilient");
+ return ERR_PTR(-EINVAL);
+ }
+
+ return nh;
+}
+
+static int nh_valid_dump_nhid(struct nlattr *attr, u32 *nh_id_p,
+ struct netlink_ext_ack *extack)
+{
+ u32 idx;
+
+ if (attr) {
+ idx = nla_get_u32(attr);
+ if (!idx) {
+ NL_SET_ERR_MSG(extack, "Invalid nexthop id");
+ return -EINVAL;
+ }
+ *nh_id_p = idx;
+ } else {
+ *nh_id_p = 0;
+ }
+
+ return 0;
+}
+
+static int nh_valid_dump_bucket_req(const struct nlmsghdr *nlh,
+ struct nh_dump_filter *filter,
+ struct netlink_callback *cb)
+{
+ struct nlattr *res_tb[ARRAY_SIZE(rtm_nh_res_bucket_policy_dump)];
+ struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_dump_bucket)];
+ int err;
+
+ err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb,
+ ARRAY_SIZE(rtm_nh_policy_dump_bucket) - 1,
+ rtm_nh_policy_dump_bucket, NULL);
+ if (err < 0)
+ return err;
+
+ err = nh_valid_dump_nhid(tb[NHA_ID], &filter->nh_id, cb->extack);
+ if (err)
+ return err;
+
+ if (tb[NHA_RES_BUCKET]) {
+ size_t max = ARRAY_SIZE(rtm_nh_res_bucket_policy_dump) - 1;
+
+ err = nla_parse_nested(res_tb, max,
+ tb[NHA_RES_BUCKET],
+ rtm_nh_res_bucket_policy_dump,
+ cb->extack);
+ if (err < 0)
+ return err;
+
+ err = nh_valid_dump_nhid(res_tb[NHA_RES_BUCKET_NH_ID],
+ &filter->res_bucket_nh_id,
+ cb->extack);
+ if (err)
+ return err;
+ }
+
+ return __nh_valid_dump_req(nlh, tb, filter, cb->extack);
+}
+
+struct rtm_dump_res_bucket_ctx {
+ struct rtm_dump_nh_ctx nh;
+ u16 bucket_index;
+ u32 done_nh_idx; /* 1 + the index of the last fully processed NH. */
+};
+
+static struct rtm_dump_res_bucket_ctx *
+rtm_dump_res_bucket_ctx(struct netlink_callback *cb)
+{
+ struct rtm_dump_res_bucket_ctx *ctx = (void *)cb->ctx;
+
+ BUILD_BUG_ON(sizeof(*ctx) > sizeof(cb->ctx));
+ return ctx;
+}
+
+struct rtm_dump_nexthop_bucket_data {
+ struct rtm_dump_res_bucket_ctx *ctx;
+ struct nh_dump_filter filter;
+};
+
+static int rtm_dump_nexthop_bucket_nh(struct sk_buff *skb,
+ struct netlink_callback *cb,
+ struct nexthop *nh,
+ struct rtm_dump_nexthop_bucket_data *dd)
+{
+ u32 portid = NETLINK_CB(cb->skb).portid;
+ struct nhmsg *nhm = nlmsg_data(cb->nlh);
+ struct nh_res_table *res_table;
+ struct nh_group *nhg;
+ u16 bucket_index;
+ int err;
+
+ if (dd->ctx->nh.idx < dd->ctx->done_nh_idx)
+ return 0;
+
+ nhg = rtnl_dereference(nh->nh_grp);
+ res_table = rtnl_dereference(nhg->res_table);
+ for (bucket_index = dd->ctx->bucket_index;
+ bucket_index < res_table->num_nh_buckets;
+ bucket_index++) {
+ struct nh_res_bucket *bucket;
+ struct nh_grp_entry *nhge;
+
+ bucket = &res_table->nh_buckets[bucket_index];
+ nhge = rtnl_dereference(bucket->nh_entry);
+ if (nh_dump_filtered(nhge->nh, &dd->filter, nhm->nh_family))
+ continue;
+
+ if (dd->filter.res_bucket_nh_id &&
+ dd->filter.res_bucket_nh_id != nhge->nh->id)
+ continue;
+
+ dd->ctx->bucket_index = bucket_index;
+ err = nh_fill_res_bucket(skb, nh, bucket, bucket_index,
+ RTM_NEWNEXTHOPBUCKET, portid,
+ cb->nlh->nlmsg_seq, NLM_F_MULTI,
+ cb->extack);
+ if (err)
+ return err;
+ }
+
+ dd->ctx->done_nh_idx = dd->ctx->nh.idx + 1;
+ dd->ctx->bucket_index = 0;
+
+ return 0;
+}
+
+static int rtm_dump_nexthop_bucket_cb(struct sk_buff *skb,
+ struct netlink_callback *cb,
+ struct nexthop *nh, void *data)
+{
+ struct rtm_dump_nexthop_bucket_data *dd = data;
+ struct nh_group *nhg;
+
+ if (!nh->is_group)
+ return 0;
+
+ nhg = rtnl_dereference(nh->nh_grp);
+ if (!nhg->resilient)
+ return 0;
+
+ return rtm_dump_nexthop_bucket_nh(skb, cb, nh, dd);
+}
+
+/* rtnl */
+static int rtm_dump_nexthop_bucket(struct sk_buff *skb,
+ struct netlink_callback *cb)
+{
+ struct rtm_dump_res_bucket_ctx *ctx = rtm_dump_res_bucket_ctx(cb);
+ struct rtm_dump_nexthop_bucket_data dd = { .ctx = ctx };
+ struct net *net = sock_net(skb->sk);
+ struct nexthop *nh;
+ int err;
+
+ err = nh_valid_dump_bucket_req(cb->nlh, &dd.filter, cb);
+ if (err)
+ return err;
+
+ if (dd.filter.nh_id) {
+ nh = nexthop_find_group_resilient(net, dd.filter.nh_id,
+ cb->extack);
+ if (IS_ERR(nh))
+ return PTR_ERR(nh);
+ err = rtm_dump_nexthop_bucket_nh(skb, cb, nh, &dd);
+ } else {
+ struct rb_root *root = &net->nexthop.rb_root;
+
+ err = rtm_dump_walk_nexthops(skb, cb, root, &ctx->nh,
+ &rtm_dump_nexthop_bucket_cb, &dd);
+ }
+
+ if (err < 0) {
+ if (likely(skb->len))
+ err = skb->len;
+ }
+
+ cb->seq = net->nexthop.seq;
+ nl_dump_check_consistent(cb, nlmsg_hdr(skb));
+ return err;
+}
+
+static int nh_valid_get_bucket_req_res_bucket(struct nlattr *res,
+ u16 *bucket_index,
+ struct netlink_ext_ack *extack)
+{
+ struct nlattr *tb[ARRAY_SIZE(rtm_nh_res_bucket_policy_get)];
+ int err;
+
+ err = nla_parse_nested(tb, ARRAY_SIZE(rtm_nh_res_bucket_policy_get) - 1,
+ res, rtm_nh_res_bucket_policy_get, extack);
+ if (err < 0)
+ return err;
+
+ if (!tb[NHA_RES_BUCKET_INDEX]) {
+ NL_SET_ERR_MSG(extack, "Bucket index is missing");
+ return -EINVAL;
+ }
+
+ *bucket_index = nla_get_u16(tb[NHA_RES_BUCKET_INDEX]);
+ return 0;
+}
+
+static int nh_valid_get_bucket_req(const struct nlmsghdr *nlh,
+ u32 *id, u16 *bucket_index,
+ struct netlink_ext_ack *extack)
+{
+ struct nlattr *tb[ARRAY_SIZE(rtm_nh_policy_get_bucket)];
+ int err;
+
+ err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb,
+ ARRAY_SIZE(rtm_nh_policy_get_bucket) - 1,
+ rtm_nh_policy_get_bucket, extack);
+ if (err < 0)
+ return err;
+
+ err = __nh_valid_get_del_req(nlh, tb, id, extack);
+ if (err)
+ return err;
+
+ if (!tb[NHA_RES_BUCKET]) {
+ NL_SET_ERR_MSG(extack, "Bucket information is missing");
+ return -EINVAL;
+ }
+
+ err = nh_valid_get_bucket_req_res_bucket(tb[NHA_RES_BUCKET],
+ bucket_index, extack);
+ if (err)
+ return err;
+
+ return 0;
+}
+
+/* rtnl */
+static int rtm_get_nexthop_bucket(struct sk_buff *in_skb, struct nlmsghdr *nlh,
+ struct netlink_ext_ack *extack)
+{
+ struct net *net = sock_net(in_skb->sk);
+ struct nh_res_table *res_table;
+ struct sk_buff *skb = NULL;
+ struct nh_group *nhg;
+ struct nexthop *nh;
+ u16 bucket_index;
+ int err;
+ u32 id;
+
+ err = nh_valid_get_bucket_req(nlh, &id, &bucket_index, extack);
+ if (err)
+ return err;
+
+ nh = nexthop_find_group_resilient(net, id, extack);
+ if (IS_ERR(nh))
+ return PTR_ERR(nh);
+
+ nhg = rtnl_dereference(nh->nh_grp);
+ res_table = rtnl_dereference(nhg->res_table);
+ if (bucket_index >= res_table->num_nh_buckets) {
+ NL_SET_ERR_MSG(extack, "Bucket index out of bounds");
+ return -ENOENT;
+ }
+
+ skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
+ if (!skb)
+ return -ENOBUFS;
+
+ err = nh_fill_res_bucket(skb, nh, &res_table->nh_buckets[bucket_index],
+ bucket_index, RTM_NEWNEXTHOPBUCKET,
+ NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
+ 0, extack);
+ if (err < 0) {
+ WARN_ON(err == -EMSGSIZE);
+ goto errout_free;
+ }
+
+ return rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
+
+errout_free:
+ kfree_skb(skb);
+ return err;
+}
+
+static void nexthop_sync_mtu(struct net_device *dev, u32 orig_mtu)
+{
+ unsigned int hash = nh_dev_hashfn(dev->ifindex);
+ struct net *net = dev_net(dev);
+ struct hlist_head *head = &net->nexthop.devhash[hash];
+ struct hlist_node *n;
+ struct nh_info *nhi;
+
+ hlist_for_each_entry_safe(nhi, n, head, dev_hash) {
+ if (nhi->fib_nhc.nhc_dev == dev) {
+ if (nhi->family == AF_INET)
+ fib_nhc_update_mtu(&nhi->fib_nhc, dev->mtu,
+ orig_mtu);
+ }
+ }
+}
+
+/* rtnl */
+static int nh_netdev_event(struct notifier_block *this,
+ unsigned long event, void *ptr)
+{
+ struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+ struct netdev_notifier_info_ext *info_ext;
+
+ switch (event) {
+ case NETDEV_DOWN:
+ case NETDEV_UNREGISTER:
+ nexthop_flush_dev(dev, event);
+ break;
+ case NETDEV_CHANGE:
+ if (!(dev_get_flags(dev) & (IFF_RUNNING | IFF_LOWER_UP)))
+ nexthop_flush_dev(dev, event);
+ break;
+ case NETDEV_CHANGEMTU:
+ info_ext = ptr;
+ nexthop_sync_mtu(dev, info_ext->ext.mtu);
+ rt_cache_flush(dev_net(dev));
+ break;
+ }
+ return NOTIFY_DONE;
+}
+
+static struct notifier_block nh_netdev_notifier = {
+ .notifier_call = nh_netdev_event,
+};
+
+static int nexthops_dump(struct net *net, struct notifier_block *nb,
+ enum nexthop_event_type event_type,
+ struct netlink_ext_ack *extack)
+{
+ struct rb_root *root = &net->nexthop.rb_root;
+ struct rb_node *node;
+ int err = 0;
+
+ for (node = rb_first(root); node; node = rb_next(node)) {
+ struct nexthop *nh;
+
+ nh = rb_entry(node, struct nexthop, rb_node);
+ err = call_nexthop_notifier(nb, net, event_type, nh, extack);
+ if (err)
+ break;
+ }
+
+ return err;
+}
+
+int register_nexthop_notifier(struct net *net, struct notifier_block *nb,
+ struct netlink_ext_ack *extack)
+{
+ int err;
+
+ rtnl_lock();
+ err = nexthops_dump(net, nb, NEXTHOP_EVENT_REPLACE, extack);
+ if (err)
+ goto unlock;
+ err = blocking_notifier_chain_register(&net->nexthop.notifier_chain,
+ nb);
+unlock:
+ rtnl_unlock();
+ return err;
+}
+EXPORT_SYMBOL(register_nexthop_notifier);
+
+int unregister_nexthop_notifier(struct net *net, struct notifier_block *nb)
+{
+ int err;
+
+ rtnl_lock();
+ err = blocking_notifier_chain_unregister(&net->nexthop.notifier_chain,
+ nb);
+ if (err)
+ goto unlock;
+ nexthops_dump(net, nb, NEXTHOP_EVENT_DEL, NULL);
+unlock:
+ rtnl_unlock();
+ return err;
+}
+EXPORT_SYMBOL(unregister_nexthop_notifier);
+
+void nexthop_set_hw_flags(struct net *net, u32 id, bool offload, bool trap)
+{
+ struct nexthop *nexthop;
+
+ rcu_read_lock();
+
+ nexthop = nexthop_find_by_id(net, id);
+ if (!nexthop)
+ goto out;
+
+ nexthop->nh_flags &= ~(RTNH_F_OFFLOAD | RTNH_F_TRAP);
+ if (offload)
+ nexthop->nh_flags |= RTNH_F_OFFLOAD;
+ if (trap)
+ nexthop->nh_flags |= RTNH_F_TRAP;
+
+out:
+ rcu_read_unlock();
+}
+EXPORT_SYMBOL(nexthop_set_hw_flags);
+
+void nexthop_bucket_set_hw_flags(struct net *net, u32 id, u16 bucket_index,
+ bool offload, bool trap)
+{
+ struct nh_res_table *res_table;
+ struct nh_res_bucket *bucket;
+ struct nexthop *nexthop;
+ struct nh_group *nhg;
+
+ rcu_read_lock();
+
+ nexthop = nexthop_find_by_id(net, id);
+ if (!nexthop || !nexthop->is_group)
+ goto out;
+
+ nhg = rcu_dereference(nexthop->nh_grp);
+ if (!nhg->resilient)
+ goto out;
+
+ if (bucket_index >= nhg->res_table->num_nh_buckets)
+ goto out;
+
+ res_table = rcu_dereference(nhg->res_table);
+ bucket = &res_table->nh_buckets[bucket_index];
+ bucket->nh_flags &= ~(RTNH_F_OFFLOAD | RTNH_F_TRAP);
+ if (offload)
+ bucket->nh_flags |= RTNH_F_OFFLOAD;
+ if (trap)
+ bucket->nh_flags |= RTNH_F_TRAP;
+
+out:
+ rcu_read_unlock();
+}
+EXPORT_SYMBOL(nexthop_bucket_set_hw_flags);
+
+void nexthop_res_grp_activity_update(struct net *net, u32 id, u16 num_buckets,
+ unsigned long *activity)
+{
+ struct nh_res_table *res_table;
+ struct nexthop *nexthop;
+ struct nh_group *nhg;
+ u16 i;
+
+ rcu_read_lock();
+
+ nexthop = nexthop_find_by_id(net, id);
+ if (!nexthop || !nexthop->is_group)
+ goto out;
+
+ nhg = rcu_dereference(nexthop->nh_grp);
+ if (!nhg->resilient)
+ goto out;
+
+ /* Instead of silently ignoring some buckets, demand that the sizes
+ * be the same.
+ */
+ res_table = rcu_dereference(nhg->res_table);
+ if (num_buckets != res_table->num_nh_buckets)
+ goto out;
+
+ for (i = 0; i < num_buckets; i++) {
+ if (test_bit(i, activity))
+ nh_res_bucket_set_busy(&res_table->nh_buckets[i]);
+ }
+
+out:
+ rcu_read_unlock();
+}
+EXPORT_SYMBOL(nexthop_res_grp_activity_update);
+
+static void __net_exit nexthop_net_exit_batch(struct list_head *net_list)
+{
+ struct net *net;
+
+ rtnl_lock();
+ list_for_each_entry(net, net_list, exit_list) {
+ flush_all_nexthops(net);
+ kfree(net->nexthop.devhash);
+ }
+ rtnl_unlock();
+}
+
+static int __net_init nexthop_net_init(struct net *net)
+{
+ size_t sz = sizeof(struct hlist_head) * NH_DEV_HASHSIZE;
+
+ net->nexthop.rb_root = RB_ROOT;
+ net->nexthop.devhash = kzalloc(sz, GFP_KERNEL);
+ if (!net->nexthop.devhash)
+ return -ENOMEM;
+ BLOCKING_INIT_NOTIFIER_HEAD(&net->nexthop.notifier_chain);
+
+ return 0;
+}
+
+static struct pernet_operations nexthop_net_ops = {
+ .init = nexthop_net_init,
+ .exit_batch = nexthop_net_exit_batch,
+};
+
+static int __init nexthop_init(void)
+{
+ register_pernet_subsys(&nexthop_net_ops);
+
+ register_netdevice_notifier(&nh_netdev_notifier);
+
+ rtnl_register(PF_UNSPEC, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
+ rtnl_register(PF_UNSPEC, RTM_DELNEXTHOP, rtm_del_nexthop, NULL, 0);
+ rtnl_register(PF_UNSPEC, RTM_GETNEXTHOP, rtm_get_nexthop,
+ rtm_dump_nexthop, 0);
+
+ rtnl_register(PF_INET, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
+ rtnl_register(PF_INET, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0);
+
+ rtnl_register(PF_INET6, RTM_NEWNEXTHOP, rtm_new_nexthop, NULL, 0);
+ rtnl_register(PF_INET6, RTM_GETNEXTHOP, NULL, rtm_dump_nexthop, 0);
+
+ rtnl_register(PF_UNSPEC, RTM_GETNEXTHOPBUCKET, rtm_get_nexthop_bucket,
+ rtm_dump_nexthop_bucket, 0);
+
+ return 0;
+}
+subsys_initcall(nexthop_init);
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-09 15:56:08 +0000