@@ -11,14 +11,33 @@ ALL_TESTS="
nexthop_single_add_err_test
nexthop_group_add_test
nexthop_group_add_err_test
+ nexthop_res_group_add_test
+ nexthop_res_group_add_err_test
nexthop_group_replace_test
nexthop_group_replace_err_test
+ nexthop_res_group_replace_test
+ nexthop_res_group_replace_err_test
+ nexthop_res_group_idle_timer_test
+ nexthop_res_group_idle_timer_del_test
+ nexthop_res_group_increase_idle_timer_test
+ nexthop_res_group_decrease_idle_timer_test
+ nexthop_res_group_unbalanced_timer_test
+ nexthop_res_group_unbalanced_timer_del_test
+ nexthop_res_group_no_unbalanced_timer_test
+ nexthop_res_group_short_unbalanced_timer_test
+ nexthop_res_group_increase_unbalanced_timer_test
+ nexthop_res_group_decrease_unbalanced_timer_test
+ nexthop_res_group_force_migrate_busy_test
nexthop_single_replace_test
nexthop_single_replace_err_test
nexthop_single_in_group_replace_test
nexthop_single_in_group_replace_err_test
+ nexthop_single_in_res_group_replace_test
+ nexthop_single_in_res_group_replace_err_test
nexthop_single_in_group_delete_test
nexthop_single_in_group_delete_err_test
+ nexthop_single_in_res_group_delete_test
+ nexthop_single_in_res_group_delete_err_test
nexthop_replay_test
nexthop_replay_err_test
"
@@ -27,6 +46,7 @@ DEV_ADDR=1337
DEV=netdevsim${DEV_ADDR}
DEVLINK_DEV=netdevsim/${DEV}
SYSFS_NET_DIR=/sys/bus/netdevsim/devices/$DEV/net/
+DEBUGFS_NET_DIR=/sys/kernel/debug/netdevsim/$DEV/
NUM_NETIFS=0
source $lib_dir/lib.sh
source $lib_dir/devlink_lib.sh
@@ -44,6 +64,28 @@ nexthop_check()
return 0
}
+nexthop_bucket_nhid_count_check()
+{
+ local group_id=$1; shift
+ local expected
+ local count
+ local nhid
+ local ret
+
+ while (($# > 0)); do
+ nhid=$1; shift
+ expected=$1; shift
+
+ count=$($IP nexthop bucket show id $group_id nhid $nhid |
+ grep "trap" | wc -l)
+ if ((expected != count)); then
+ return 1
+ fi
+ done
+
+ return 0
+}
+
nexthop_resource_check()
{
local expected_occ=$1; shift
@@ -159,6 +201,71 @@ nexthop_group_add_err_test()
nexthop_resource_set 9999
}
+nexthop_res_group_add_test()
+{
+ RET=0
+
+ $IP nexthop add id 1 via 192.0.2.2 dev dummy1
+ $IP nexthop add id 2 via 192.0.2.3 dev dummy1
+
+ $IP nexthop add id 10 group 1/2 type resilient buckets 4
+ nexthop_check "id 10" "id 10 group 1/2 type resilient buckets 4 idle_timer 120 unbalanced_timer 0 unbalanced_time 0 trap"
+ check_err $? "Unexpected nexthop group entry"
+
+ nexthop_bucket_nhid_count_check 10 1 2
+ check_err $? "Wrong nexthop buckets count"
+ nexthop_bucket_nhid_count_check 10 2 2
+ check_err $? "Wrong nexthop buckets count"
+
+ nexthop_resource_check 6
+ check_err $? "Wrong nexthop occupancy"
+
+ $IP nexthop del id 10
+ nexthop_resource_check 2
+ check_err $? "Wrong nexthop occupancy after delete"
+
+ $IP nexthop add id 10 group 1,3/2,2 type resilient buckets 5
+ nexthop_check "id 10" "id 10 group 1,3/2,2 type resilient buckets 5 idle_timer 120 unbalanced_timer 0 unbalanced_time 0 trap"
+ check_err $? "Unexpected weighted nexthop group entry"
+
+ nexthop_bucket_nhid_count_check 10 1 3
+ check_err $? "Wrong nexthop buckets count"
+ nexthop_bucket_nhid_count_check 10 2 2
+ check_err $? "Wrong nexthop buckets count"
+
+ nexthop_resource_check 7
+ check_err $? "Wrong weighted nexthop occupancy"
+
+ $IP nexthop del id 10
+ nexthop_resource_check 2
+ check_err $? "Wrong nexthop occupancy after delete"
+
+ log_test "Resilient nexthop group add and delete"
+
+ $IP nexthop flush &> /dev/null
+}
+
+nexthop_res_group_add_err_test()
+{
+ RET=0
+
+ nexthop_resource_set 2
+
+ $IP nexthop add id 1 via 192.0.2.2 dev dummy1
+ $IP nexthop add id 2 via 192.0.2.3 dev dummy1
+
+ $IP nexthop add id 10 group 1/2 type resilient buckets 4 &> /dev/null
+ check_fail $? "Nexthop group addition succeeded when should fail"
+
+ nexthop_resource_check 2
+ check_err $? "Wrong nexthop occupancy"
+
+ log_test "Resilient nexthop group add failure"
+
+ $IP nexthop flush &> /dev/null
+ nexthop_resource_set 9999
+}
+
nexthop_group_replace_test()
{
RET=0
@@ -206,6 +313,411 @@ nexthop_group_replace_err_test()
nexthop_resource_set 9999
}
+nexthop_res_group_replace_test()
+{
+ RET=0
+
+ $IP nexthop add id 1 via 192.0.2.2 dev dummy1
+ $IP nexthop add id 2 via 192.0.2.3 dev dummy1
+ $IP nexthop add id 3 via 192.0.2.4 dev dummy1
+ $IP nexthop add id 10 group 1/2 type resilient buckets 6
+
+ $IP nexthop replace id 10 group 1/2/3 type resilient
+ nexthop_check "id 10" "id 10 group 1/2/3 type resilient buckets 6 idle_timer 120 unbalanced_timer 0 unbalanced_time 0 trap"
+ check_err $? "Unexpected nexthop group entry"
+
+ nexthop_bucket_nhid_count_check 10 1 2
+ check_err $? "Wrong nexthop buckets count"
+ nexthop_bucket_nhid_count_check 10 2 2
+ check_err $? "Wrong nexthop buckets count"
+ nexthop_bucket_nhid_count_check 10 3 2
+ check_err $? "Wrong nexthop buckets count"
+
+ nexthop_resource_check 9
+ check_err $? "Wrong nexthop occupancy"
+
+ log_test "Resilient nexthop group replace"
+
+ $IP nexthop flush &> /dev/null
+}
+
+nexthop_res_group_replace_err_test()
+{
+ RET=0
+
+ $IP nexthop add id 1 via 192.0.2.2 dev dummy1
+ $IP nexthop add id 2 via 192.0.2.3 dev dummy1
+ $IP nexthop add id 3 via 192.0.2.4 dev dummy1
+ $IP nexthop add id 10 group 1/2 type resilient buckets 6
+
+ ip netns exec testns1 \
+ echo 1 > $DEBUGFS_NET_DIR/fib/fail_res_nexthop_group_replace
+ $IP nexthop replace id 10 group 1/2/3 type resilient &> /dev/null
+ check_fail $? "Nexthop group replacement succeeded when should fail"
+
+ nexthop_check "id 10" "id 10 group 1/2 type resilient buckets 6 idle_timer 120 unbalanced_timer 0 unbalanced_time 0 trap"
+ check_err $? "Unexpected nexthop group entry after failure"
+
+ nexthop_bucket_nhid_count_check 10 1 3
+ check_err $? "Wrong nexthop buckets count"
+ nexthop_bucket_nhid_count_check 10 2 3
+ check_err $? "Wrong nexthop buckets count"
+
+ nexthop_resource_check 9
+ check_err $? "Wrong nexthop occupancy after failure"
+
+ log_test "Resilient nexthop group replace failure"
+
+ $IP nexthop flush &> /dev/null
+ ip netns exec testns1 \
+ echo 0 > $DEBUGFS_NET_DIR/fib/fail_res_nexthop_group_replace
+}
+
+nexthop_res_mark_buckets_busy()
+{
+ local group_id=$1; shift
+ local nhid=$1; shift
+ local count=$1; shift
+ local index
+
+ for index in $($IP -j nexthop bucket show id $group_id nhid $nhid |
+ jq '.[].bucket.index' | head -n ${count:--0})
+ do
+ echo $group_id $index \
+ > $DEBUGFS_NET_DIR/fib/nexthop_bucket_activity
+ done
+}
+
+nexthop_res_num_nhid_buckets()
+{
+ local group_id=$1; shift
+ local nhid=$1; shift
+
+ $IP -j nexthop bucket show id $group_id nhid $nhid | jq length
+}
+
+nexthop_res_group_idle_timer_test()
+{
+ $IP nexthop add id 1 via 192.0.2.2 dev dummy1
+ $IP nexthop add id 2 via 192.0.2.3 dev dummy1
+
+ RET=0
+
+ $IP nexthop add id 10 group 1/2 type resilient buckets 8 idle_timer 4
+ nexthop_res_mark_buckets_busy 10 1
+ $IP nexthop replace id 10 group 1/2,3 type resilient
+
+ nexthop_bucket_nhid_count_check 10 1 4 2 4
+ check_err $? "Group expected to be unbalanced"
+
+ sleep 6
+
+ nexthop_bucket_nhid_count_check 10 1 2 2 6
+ check_err $? "Group expected to be balanced"
+
+ log_test "Bucket migration after idle timer"
+
+ $IP nexthop flush &> /dev/null
+}
+
+nexthop_res_group_idle_timer_del_test()
+{
+ $IP nexthop add id 1 via 192.0.2.2 dev dummy1
+ $IP nexthop add id 2 via 192.0.2.3 dev dummy1
+ $IP nexthop add id 3 via 192.0.2.3 dev dummy1
+
+ RET=0
+
+ $IP nexthop add id 10 group 1,50/2,50/3,1 \
+ type resilient buckets 8 idle_timer 6
+ nexthop_res_mark_buckets_busy 10 1
+ $IP nexthop replace id 10 group 1,50/2,150/3,1 type resilient
+
+ nexthop_bucket_nhid_count_check 10 1 4 2 4 3 0
+ check_err $? "Group expected to be unbalanced"
+
+ sleep 4
+
+ # Deletion prompts group replacement. Check that the bucket timers
+ # are kept.
+ $IP nexthop delete id 3
+
+ nexthop_bucket_nhid_count_check 10 1 4 2 4
+ check_err $? "Group expected to still be unbalanced"
+
+ sleep 4
+
+ nexthop_bucket_nhid_count_check 10 1 2 2 6
+ check_err $? "Group expected to be balanced"
+
+ log_test "Bucket migration after idle timer (with delete)"
+
+ $IP nexthop flush &> /dev/null
+}
+
+__nexthop_res_group_increase_timer_test()
+{
+ local timer=$1; shift
+
+ $IP nexthop add id 1 via 192.0.2.2 dev dummy1
+ $IP nexthop add id 2 via 192.0.2.3 dev dummy1
+
+ RET=0
+
+ $IP nexthop add id 10 group 1/2 type resilient buckets 8 $timer 4
+ nexthop_res_mark_buckets_busy 10 1
+ $IP nexthop replace id 10 group 1/2,3 type resilient
+
+ nexthop_bucket_nhid_count_check 10 2 6
+ check_fail $? "Group expected to be unbalanced"
+
+ sleep 2
+ $IP nexthop replace id 10 group 1/2,3 type resilient $timer 8
+ sleep 4
+
+ # 6 seconds, past the original timer.
+ nexthop_bucket_nhid_count_check 10 2 6
+ check_fail $? "Group still expected to be unbalanced"
+
+ sleep 4
+
+ # 10 seconds, past the new timer.
+ nexthop_bucket_nhid_count_check 10 2 6
+ check_err $? "Group expected to be balanced"
+
+ log_test "Bucket migration after $timer increase"
+
+ $IP nexthop flush &> /dev/null
+}
+
+__nexthop_res_group_decrease_timer_test()
+{
+ local timer=$1; shift
+
+ $IP nexthop add id 1 via 192.0.2.2 dev dummy1
+ $IP nexthop add id 2 via 192.0.2.3 dev dummy1
+
+ RET=0
+
+ $IP nexthop add id 10 group 1/2 type resilient buckets 8 $timer 8
+ nexthop_res_mark_buckets_busy 10 1
+ $IP nexthop replace id 10 group 1/2,3 type resilient
+
+ nexthop_bucket_nhid_count_check 10 2 6
+ check_fail $? "Group expected to be unbalanced"
+
+ sleep 2
+ $IP nexthop replace id 10 group 1/2,3 type resilient $timer 4
+ sleep 4
+
+ # 6 seconds, past the new timer, before the old timer.
+ nexthop_bucket_nhid_count_check 10 2 6
+ check_err $? "Group expected to be balanced"
+
+ log_test "Bucket migration after $timer decrease"
+
+ $IP nexthop flush &> /dev/null
+}
+
+__nexthop_res_group_increase_timer_del_test()
+{
+ local timer=$1; shift
+
+ $IP nexthop add id 1 via 192.0.2.2 dev dummy1
+ $IP nexthop add id 2 via 192.0.2.3 dev dummy1
+ $IP nexthop add id 3 via 192.0.2.3 dev dummy1
+
+ RET=0
+
+ $IP nexthop add id 10 group 1,100/2,100/3,1 \
+ type resilient buckets 8 $timer 4
+ nexthop_res_mark_buckets_busy 10 1
+ $IP nexthop replace id 10 group 1,100/2,300/3,1 type resilient
+
+ nexthop_bucket_nhid_count_check 10 2 6
+ check_fail $? "Group expected to be unbalanced"
+
+ sleep 2
+ $IP nexthop replace id 10 group 1/2,3 type resilient $timer 8
+ sleep 4
+
+ # 6 seconds, past the original timer.
+ nexthop_bucket_nhid_count_check 10 2 6
+ check_fail $? "Group still expected to be unbalanced"
+
+ sleep 4
+
+ # 10 seconds, past the new timer.
+ nexthop_bucket_nhid_count_check 10 2 6
+ check_err $? "Group expected to be balanced"
+
+ log_test "Bucket migration after $timer increase"
+
+ $IP nexthop flush &> /dev/null
+}
+
+nexthop_res_group_increase_idle_timer_test()
+{
+ __nexthop_res_group_increase_timer_test idle_timer
+}
+
+nexthop_res_group_decrease_idle_timer_test()
+{
+ __nexthop_res_group_decrease_timer_test idle_timer
+}
+
+nexthop_res_group_unbalanced_timer_test()
+{
+ local i
+
+ $IP nexthop add id 1 via 192.0.2.2 dev dummy1
+ $IP nexthop add id 2 via 192.0.2.3 dev dummy1
+
+ RET=0
+
+ $IP nexthop add id 10 group 1/2 type resilient \
+ buckets 8 idle_timer 6 unbalanced_timer 10
+ nexthop_res_mark_buckets_busy 10 1
+ $IP nexthop replace id 10 group 1/2,3 type resilient
+
+ for i in 1 2; do
+ sleep 4
+ nexthop_bucket_nhid_count_check 10 1 4 2 4
+ check_err $? "$i: Group expected to be unbalanced"
+ nexthop_res_mark_buckets_busy 10 1
+ done
+
+ # 3 x sleep 4 > unbalanced timer 10
+ sleep 4
+ nexthop_bucket_nhid_count_check 10 1 2 2 6
+ check_err $? "Group expected to be balanced"
+
+ log_test "Bucket migration after unbalanced timer"
+
+ $IP nexthop flush &> /dev/null
+}
+
+nexthop_res_group_unbalanced_timer_del_test()
+{
+ local i
+
+ $IP nexthop add id 1 via 192.0.2.2 dev dummy1
+ $IP nexthop add id 2 via 192.0.2.3 dev dummy1
+ $IP nexthop add id 3 via 192.0.2.3 dev dummy1
+
+ RET=0
+
+ $IP nexthop add id 10 group 1,50/2,50/3,1 type resilient \
+ buckets 8 idle_timer 6 unbalanced_timer 10
+ nexthop_res_mark_buckets_busy 10 1
+ $IP nexthop replace id 10 group 1,50/2,150/3,1 type resilient
+
+ # Check that NH delete does not reset unbalanced time.
+ sleep 4
+ $IP nexthop delete id 3
+ nexthop_bucket_nhid_count_check 10 1 4 2 4
+ check_err $? "1: Group expected to be unbalanced"
+ nexthop_res_mark_buckets_busy 10 1
+
+ sleep 4
+ nexthop_bucket_nhid_count_check 10 1 4 2 4
+ check_err $? "2: Group expected to be unbalanced"
+ nexthop_res_mark_buckets_busy 10 1
+
+ # 3 x sleep 4 > unbalanced timer 10
+ sleep 4
+ nexthop_bucket_nhid_count_check 10 1 2 2 6
+ check_err $? "Group expected to be balanced"
+
+ log_test "Bucket migration after unbalanced timer (with delete)"
+
+ $IP nexthop flush &> /dev/null
+}
+
+nexthop_res_group_no_unbalanced_timer_test()
+{
+ local i
+
+ $IP nexthop add id 1 via 192.0.2.2 dev dummy1
+ $IP nexthop add id 2 via 192.0.2.3 dev dummy1
+
+ RET=0
+
+ $IP nexthop add id 10 group 1/2 type resilient buckets 8
+ nexthop_res_mark_buckets_busy 10 1
+ $IP nexthop replace id 10 group 1/2,3 type resilient
+
+ for i in $(seq 3); do
+ sleep 60
+ nexthop_bucket_nhid_count_check 10 2 6
+ check_fail $? "$i: Group expected to be unbalanced"
+ nexthop_res_mark_buckets_busy 10 1
+ done
+
+ log_test "Buckets never force-migrated without unbalanced timer"
+
+ $IP nexthop flush &> /dev/null
+}
+
+nexthop_res_group_short_unbalanced_timer_test()
+{
+ $IP nexthop add id 1 via 192.0.2.2 dev dummy1
+ $IP nexthop add id 2 via 192.0.2.3 dev dummy1
+
+ RET=0
+
+ $IP nexthop add id 10 group 1/2 type resilient \
+ buckets 8 idle_timer 120 unbalanced_timer 4
+ nexthop_res_mark_buckets_busy 10 1
+ $IP nexthop replace id 10 group 1/2,3 type resilient
+
+ nexthop_bucket_nhid_count_check 10 2 6
+ check_fail $? "Group expected to be unbalanced"
+
+ sleep 5
+
+ nexthop_bucket_nhid_count_check 10 2 6
+ check_err $? "Group expected to be balanced"
+
+ log_test "Bucket migration after unbalanced < idle timer"
+
+ $IP nexthop flush &> /dev/null
+}
+
+nexthop_res_group_increase_unbalanced_timer_test()
+{
+ __nexthop_res_group_increase_timer_test unbalanced_timer
+}
+
+nexthop_res_group_decrease_unbalanced_timer_test()
+{
+ __nexthop_res_group_decrease_timer_test unbalanced_timer
+}
+
+nexthop_res_group_force_migrate_busy_test()
+{
+ $IP nexthop add id 1 via 192.0.2.2 dev dummy1
+ $IP nexthop add id 2 via 192.0.2.3 dev dummy1
+
+ RET=0
+
+ $IP nexthop add id 10 group 1/2 type resilient \
+ buckets 8 idle_timer 120
+ nexthop_res_mark_buckets_busy 10 1
+ $IP nexthop replace id 10 group 1/2,3 type resilient
+
+ nexthop_bucket_nhid_count_check 10 2 6
+ check_fail $? "Group expected to be unbalanced"
+
+ $IP nexthop replace id 10 group 2 type resilient
+ nexthop_bucket_nhid_count_check 10 2 8
+ check_err $? "All buckets expected to have migrated"
+
+ log_test "Busy buckets force-migrated when NH removed"
+
+ $IP nexthop flush &> /dev/null
+}
+
nexthop_single_replace_test()
{
RET=0
@@ -299,6 +811,63 @@ nexthop_single_in_group_replace_err_test()
nexthop_resource_set 9999
}
+nexthop_single_in_res_group_replace_test()
+{
+ RET=0
+
+ $IP nexthop add id 1 via 192.0.2.2 dev dummy1
+ $IP nexthop add id 2 via 192.0.2.3 dev dummy1
+ $IP nexthop add id 10 group 1/2 type resilient buckets 4
+
+ $IP nexthop replace id 1 via 192.0.2.4 dev dummy1
+ check_err $? "Failed to replace nexthop when should not"
+
+ nexthop_check "id 10" "id 10 group 1/2 type resilient buckets 4 idle_timer 120 unbalanced_timer 0 unbalanced_time 0 trap"
+ check_err $? "Unexpected nexthop group entry"
+
+ nexthop_bucket_nhid_count_check 10 1 2 2 2
+ check_err $? "Wrong nexthop buckets count"
+
+ nexthop_resource_check 6
+ check_err $? "Wrong nexthop occupancy"
+
+ log_test "Single nexthop replace while in resilient group"
+
+ $IP nexthop flush &> /dev/null
+}
+
+nexthop_single_in_res_group_replace_err_test()
+{
+ RET=0
+
+ $IP nexthop add id 1 via 192.0.2.2 dev dummy1
+ $IP nexthop add id 2 via 192.0.2.3 dev dummy1
+ $IP nexthop add id 10 group 1/2 type resilient buckets 4
+
+ ip netns exec testns1 \
+ echo 1 > $DEBUGFS_NET_DIR/fib/fail_nexthop_bucket_replace
+ $IP nexthop replace id 1 via 192.0.2.4 dev dummy1 &> /dev/null
+ check_fail $? "Nexthop replacement succeeded when should fail"
+
+ nexthop_check "id 1" "id 1 via 192.0.2.2 dev dummy1 scope link trap"
+ check_err $? "Unexpected nexthop entry after failure"
+
+ nexthop_check "id 10" "id 10 group 1/2 type resilient buckets 4 idle_timer 120 unbalanced_timer 0 unbalanced_time 0 trap"
+ check_err $? "Unexpected nexthop group entry after failure"
+
+ nexthop_bucket_nhid_count_check 10 1 2 2 2
+ check_err $? "Wrong nexthop buckets count"
+
+ nexthop_resource_check 6
+ check_err $? "Wrong nexthop occupancy"
+
+ log_test "Single nexthop replace while in resilient group failure"
+
+ $IP nexthop flush &> /dev/null
+ ip netns exec testns1 \
+ echo 0 > $DEBUGFS_NET_DIR/fib/fail_nexthop_bucket_replace
+}
+
nexthop_single_in_group_delete_test()
{
RET=0
@@ -346,6 +915,57 @@ nexthop_single_in_group_delete_err_test()
nexthop_resource_set 9999
}
+nexthop_single_in_res_group_delete_test()
+{
+ RET=0
+
+ $IP nexthop add id 1 via 192.0.2.2 dev dummy1
+ $IP nexthop add id 2 via 192.0.2.3 dev dummy1
+ $IP nexthop add id 10 group 1/2 type resilient buckets 4
+
+ $IP nexthop del id 1
+ nexthop_check "id 10" "id 10 group 2 type resilient buckets 4 idle_timer 120 unbalanced_timer 0 unbalanced_time 0 trap"
+ check_err $? "Unexpected nexthop group entry"
+
+ nexthop_bucket_nhid_count_check 10 2 4
+ check_err $? "Wrong nexthop buckets count"
+
+ nexthop_resource_check 5
+ check_err $? "Wrong nexthop occupancy"
+
+ log_test "Single nexthop delete while in resilient group"
+
+ $IP nexthop flush &> /dev/null
+}
+
+nexthop_single_in_res_group_delete_err_test()
+{
+ RET=0
+
+ $IP nexthop add id 1 via 192.0.2.2 dev dummy1
+ $IP nexthop add id 2 via 192.0.2.3 dev dummy1
+ $IP nexthop add id 3 via 192.0.2.4 dev dummy1
+ $IP nexthop add id 10 group 1/2/3 type resilient buckets 6
+
+ ip netns exec testns1 \
+ echo 1 > $DEBUGFS_NET_DIR/fib/fail_nexthop_bucket_replace
+ $IP nexthop del id 1
+
+ # We failed to replace the two nexthop buckets that were originally
+ # assigned to nhid 1.
+ nexthop_bucket_nhid_count_check 10 2 2 3 2
+ check_err $? "Wrong nexthop buckets count"
+
+ nexthop_resource_check 8
+ check_err $? "Wrong nexthop occupancy"
+
+ log_test "Single nexthop delete while in resilient group failure"
+
+ $IP nexthop flush &> /dev/null
+ ip netns exec testns1 \
+ echo 0 > $DEBUGFS_NET_DIR/fib/fail_nexthop_bucket_replace
+}
+
nexthop_replay_test()
{
RET=0