diff --git a/net/ipv4/nexthop.c b/net/ipv4/nexthop.c
index 49e8adce5b96..5fe5a3981d43 100644
--- a/net/ipv4/nexthop.c
+++ b/net/ipv4/nexthop.c
@@ -548,6 +548,16 @@ int nexthop_for_each_fib6_nh(struct nexthop *nh,
}
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)
{
@@ -559,10 +569,8 @@ int fib6_check_nexthop(struct nexthop *nh, struct fib6_config *cfg,
* routing it can not use nexthop objects. mlxsw also does not allow
* fib6_src on routes.
*/
- if (!ipv6_addr_any(&cfg->fc_src)) {
- NL_SET_ERR_MSG(extack, "IPv6 routes using source address can not use nexthop objects");
+ if (cfg && check_src_addr(&cfg->fc_src, extack) < 0)
return -EINVAL;
- }
if (nh->is_group) {
struct nh_group *nhg;
@@ -583,6 +591,25 @@ no_v4_nh:
}
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 nexthop *nh, u8 scope,
struct netlink_ext_ack *extack)
{
@@ -631,6 +658,21 @@ 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 void nh_group_rebalance(struct nh_group *nhg)
{
int total = 0;
@@ -723,6 +765,7 @@ static void remove_nexthop_group(struct nexthop *nh, struct nl_info *nlinfo)
}
}
+/* not called for nexthop replace */
static void __remove_nexthop_fib(struct net *net, struct nexthop *nh)
{
struct fib6_info *f6i, *tmp;
@@ -777,10 +820,171 @@ static void remove_nexthop(struct net *net, struct nexthop *nh,
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 fib6_info *f6i;
+
+ 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);
+}
+
+static int replace_nexthop_grp(struct net *net, struct nexthop *old,
+ struct nexthop *new,
+ struct netlink_ext_ack *extack)
+{
+ struct nh_group *oldg, *newg;
+ int i;
+
+ 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);
+
+ /* 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);
+
+ 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 int replace_nexthop_single(struct net *net, struct nexthop *old,
+ struct nexthop *new,
+ struct netlink_ext_ack *extack)
+{
+ struct nh_info *oldi, *newi;
+
+ if (new->is_group) {
+ NL_SET_ERR_MSG(extack, "Can not replace a nexthop with a nexthop group.");
+ return -EINVAL;
+ }
+
+ oldi = rtnl_dereference(old->nh_info);
+ newi = rtnl_dereference(new->nh_info);
+
+ newi->nh_parent = old;
+ oldi->nh_parent = new;
+
+ old->protocol = new->protocol;
+ old->nh_flags = new->nh_flags;
+
+ rcu_assign_pointer(old->nh_info, newi);
+ rcu_assign_pointer(new->nh_info, oldi);
+
+ return 0;
+}
+
+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, struct netlink_ext_ack *extack)
{
- return -EEXIST;
+ 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, extack);
+ else
+ err = replace_nexthop_single(net, old, new, extack);
+
+ if (!err) {
+ nh_rt_cache_flush(net, old);
+
+ __remove_nexthop(net, new, NULL);
+ nexthop_put(new);
+ }
+
+ return err;
}
/* called with rtnl_lock held */
@@ -792,6 +996,7 @@ static int insert_nexthop(struct net *net, struct nexthop *new_nh,
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;
@@ -811,8 +1016,10 @@ static int insert_nexthop(struct net *net, struct nexthop *new_nh,
pp = &next->rb_right;
} else if (replace) {
rc = replace_nexthop(net, nh, new_nh, extack);
- if (!rc)
+ if (!rc) {
new_nh = nh; /* send notification with old nh */
+ replace_notify = 1;
+ }
goto out;
} else {
/* id already exists and not a replace */
@@ -833,6 +1040,8 @@ out:
if (!rc) {
nh_base_seq_inc(net);
nexthop_notify(RTM_NEWNEXTHOP, new_nh, &cfg->nlinfo);
+ if (replace_notify)
+ nexthop_replace_notify(net, new_nh, &cfg->nlinfo);
}
return rc;