Re: [RFC iproute2] ip: bridge: use -human to convert time-related values to seconds

[Vladimir Oltean <olteanv@gmail.com>]

Hi Nikolay,

On Sun, Jul 26, 2020 at 01:43:23PM +0300, Nikolay Aleksandrov wrote:
> We have been printing and expecting the time-related bridge options
> scaled by USER_HZ which is confusing to users and hasn't been documented
> anywhere. Unfortunately that has been the case for years and people who
> use ip-link are scaling the values themselves by now. In order to help
> anyone who wants to show and set the values in normal time (seconds) we
> can use the ip -h[uman] argument. When it is supplied all values will be
> shown and expected in their normal time (currently all in seconds).
> The man page is also adjusted everywhere to explain the current scaling
> and the new option.
> 
> Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
> ---
> To avoid printing the values twice (i.e. the _ms solution) we can use
> the -human argument to scale them properly. Obviously -human is an alias
> right now for -human-readable, that's why I refer to it only as -human
> in the ip-link man page since we are now using it for setting values, too.
> Alternatively this can be any new option such as -Timescale.
> 
> What do you think ?
> 

The old ip-link also accepts commands of the form:
"ip -h link set br0 type bridge ageing_time 300"

so I'm not sure, with my user hat on, how can I know whether the
particular iproute2 binary I'm using understood what I meant or not.

>  ip/iplink_bridge.c    | 49 +++++++++++++++++++++++++------------------
>  man/man8/ip-link.8.in | 33 +++++++++++++++++------------
>  2 files changed, 49 insertions(+), 33 deletions(-)
> 
> diff --git a/ip/iplink_bridge.c b/ip/iplink_bridge.c
> index 3e81aa059cb3..8313cdbd0a92 100644
> --- a/ip/iplink_bridge.c
> +++ b/ip/iplink_bridge.c
> @@ -24,6 +24,7 @@
>  
>  static unsigned int xstats_print_attr;
>  static int filter_index;
> +static int hz = 1;
>  
>  static void print_explain(FILE *f)
>  {
> @@ -64,6 +65,9 @@ static void print_explain(FILE *f)
>  		"		  [ nf_call_arptables NF_CALL_ARPTABLES ]\n"
>  		"\n"
>  		"Where: VLAN_PROTOCOL := { 802.1Q | 802.1ad }\n"
> +		"Note that all time-related options are scaled by USER_HZ (%d), in order to\n"
> +		"set and show them as seconds please use the ip -h[uman] argument.\n",
> +		get_user_hz()
>  	);
>  }
>  
> @@ -85,31 +89,34 @@ static int bridge_parse_opt(struct link_util *lu, int argc, char **argv,
>  {
>  	__u32 val;
>  
> +	if (human_readable)
> +		hz = get_user_hz();
> +
>  	while (argc > 0) {
>  		if (matches(*argv, "forward_delay") == 0) {
>  			NEXT_ARG();
>  			if (get_u32(&val, *argv, 0))
>  				invarg("invalid forward_delay", *argv);
>  
> -			addattr32(n, 1024, IFLA_BR_FORWARD_DELAY, val);
> +			addattr32(n, 1024, IFLA_BR_FORWARD_DELAY, val * hz);
>  		} else if (matches(*argv, "hello_time") == 0) {
>  			NEXT_ARG();
>  			if (get_u32(&val, *argv, 0))
>  				invarg("invalid hello_time", *argv);
>  
> -			addattr32(n, 1024, IFLA_BR_HELLO_TIME, val);
> +			addattr32(n, 1024, IFLA_BR_HELLO_TIME, val * hz);
>  		} else if (matches(*argv, "max_age") == 0) {
>  			NEXT_ARG();
>  			if (get_u32(&val, *argv, 0))
>  				invarg("invalid max_age", *argv);
>  
> -			addattr32(n, 1024, IFLA_BR_MAX_AGE, val);
> +			addattr32(n, 1024, IFLA_BR_MAX_AGE, val * hz);
>  		} else if (matches(*argv, "ageing_time") == 0) {
>  			NEXT_ARG();
>  			if (get_u32(&val, *argv, 0))
>  				invarg("invalid ageing_time", *argv);

Also, you seem to have skipped updating the docs for ageing_time.

>  
> -			addattr32(n, 1024, IFLA_BR_AGEING_TIME, val);
> +			addattr32(n, 1024, IFLA_BR_AGEING_TIME, val * hz);
>  		} else if (matches(*argv, "stp_state") == 0) {
>  			NEXT_ARG();
>  			if (get_u32(&val, *argv, 0))
> @@ -266,7 +273,7 @@ static int bridge_parse_opt(struct link_util *lu, int argc, char **argv,
>  				       *argv);
>  
>  			addattr64(n, 1024, IFLA_BR_MCAST_LAST_MEMBER_INTVL,
> -				  mcast_last_member_intvl);
> +				  mcast_last_member_intvl * hz);
>  		} else if (matches(*argv, "mcast_membership_interval") == 0) {
>  			__u64 mcast_membership_intvl;
>  
> @@ -276,7 +283,7 @@ static int bridge_parse_opt(struct link_util *lu, int argc, char **argv,
>  				       *argv);
>  
>  			addattr64(n, 1024, IFLA_BR_MCAST_MEMBERSHIP_INTVL,
> -				  mcast_membership_intvl);
> +				  mcast_membership_intvl * hz);
>  		} else if (matches(*argv, "mcast_querier_interval") == 0) {
>  			__u64 mcast_querier_intvl;
>  
> @@ -286,7 +293,7 @@ static int bridge_parse_opt(struct link_util *lu, int argc, char **argv,
>  				       *argv);
>  
>  			addattr64(n, 1024, IFLA_BR_MCAST_QUERIER_INTVL,
> -				  mcast_querier_intvl);
> +				  mcast_querier_intvl * hz);
>  		} else if (matches(*argv, "mcast_query_interval") == 0) {
>  			__u64 mcast_query_intvl;
>  
> @@ -296,7 +303,7 @@ static int bridge_parse_opt(struct link_util *lu, int argc, char **argv,
>  				       *argv);
>  
>  			addattr64(n, 1024, IFLA_BR_MCAST_QUERY_INTVL,
> -				  mcast_query_intvl);
> +				  mcast_query_intvl * hz);
>  		} else if (!matches(*argv, "mcast_query_response_interval")) {
>  			__u64 mcast_query_resp_intvl;
>  
> @@ -306,7 +313,7 @@ static int bridge_parse_opt(struct link_util *lu, int argc, char **argv,
>  				       *argv);
>  
>  			addattr64(n, 1024, IFLA_BR_MCAST_QUERY_RESPONSE_INTVL,
> -				  mcast_query_resp_intvl);
> +				  mcast_query_resp_intvl * hz);
>  		} else if (!matches(*argv, "mcast_startup_query_interval")) {
>  			__u64 mcast_startup_query_intvl;
>  
> @@ -316,7 +323,7 @@ static int bridge_parse_opt(struct link_util *lu, int argc, char **argv,
>  				       *argv);
>  
>  			addattr64(n, 1024, IFLA_BR_MCAST_STARTUP_QUERY_INTVL,
> -				  mcast_startup_query_intvl);
> +				  mcast_startup_query_intvl * hz);
>  		} else if (matches(*argv, "mcast_stats_enabled") == 0) {
>  			__u8 mcast_stats_enabled;
>  
> @@ -406,30 +413,32 @@ static void bridge_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
>  {
>  	if (!tb)
>  		return;
> +	if (human_readable)
> +		hz = get_user_hz();
>  
>  	if (tb[IFLA_BR_FORWARD_DELAY])
>  		print_uint(PRINT_ANY,
>  			   "forward_delay",
>  			   "forward_delay %u ",
> -			   rta_getattr_u32(tb[IFLA_BR_FORWARD_DELAY]));
> +			   rta_getattr_u32(tb[IFLA_BR_FORWARD_DELAY]) / hz);
>  
>  	if (tb[IFLA_BR_HELLO_TIME])
>  		print_uint(PRINT_ANY,
>  			   "hello_time",
>  			   "hello_time %u ",
> -			   rta_getattr_u32(tb[IFLA_BR_HELLO_TIME]));
> +			   rta_getattr_u32(tb[IFLA_BR_HELLO_TIME]) / hz);
>  
>  	if (tb[IFLA_BR_MAX_AGE])
>  		print_uint(PRINT_ANY,
>  			   "max_age",
>  			   "max_age %u ",
> -			   rta_getattr_u32(tb[IFLA_BR_MAX_AGE]));
> +			   rta_getattr_u32(tb[IFLA_BR_MAX_AGE]) / hz);
>  
>  	if (tb[IFLA_BR_AGEING_TIME])
>  		print_uint(PRINT_ANY,
>  			   "ageing_time",
>  			   "ageing_time %u ",
> -			   rta_getattr_u32(tb[IFLA_BR_AGEING_TIME]));
> +			   rta_getattr_u32(tb[IFLA_BR_AGEING_TIME]) / hz);
>  
>  	if (tb[IFLA_BR_STP_STATE])
>  		print_uint(PRINT_ANY,
> @@ -605,37 +614,37 @@ static void bridge_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
>  		print_lluint(PRINT_ANY,
>  			     "mcast_last_member_intvl",
>  			     "mcast_last_member_interval %llu ",
> -			     rta_getattr_u64(tb[IFLA_BR_MCAST_LAST_MEMBER_INTVL]));
> +			     rta_getattr_u64(tb[IFLA_BR_MCAST_LAST_MEMBER_INTVL]) / hz);
>  
>  	if (tb[IFLA_BR_MCAST_MEMBERSHIP_INTVL])
>  		print_lluint(PRINT_ANY,
>  			     "mcast_membership_intvl",
>  			     "mcast_membership_interval %llu ",
> -			     rta_getattr_u64(tb[IFLA_BR_MCAST_MEMBERSHIP_INTVL]));
> +			     rta_getattr_u64(tb[IFLA_BR_MCAST_MEMBERSHIP_INTVL]) / hz);
>  
>  	if (tb[IFLA_BR_MCAST_QUERIER_INTVL])
>  		print_lluint(PRINT_ANY,
>  			     "mcast_querier_intvl",
>  			     "mcast_querier_interval %llu ",
> -			     rta_getattr_u64(tb[IFLA_BR_MCAST_QUERIER_INTVL]));
> +			     rta_getattr_u64(tb[IFLA_BR_MCAST_QUERIER_INTVL]) / hz);
>  
>  	if (tb[IFLA_BR_MCAST_QUERY_INTVL])
>  		print_lluint(PRINT_ANY,
>  			     "mcast_query_intvl",
>  			     "mcast_query_interval %llu ",
> -			     rta_getattr_u64(tb[IFLA_BR_MCAST_QUERY_INTVL]));
> +			     rta_getattr_u64(tb[IFLA_BR_MCAST_QUERY_INTVL]) / hz);
>  
>  	if (tb[IFLA_BR_MCAST_QUERY_RESPONSE_INTVL])
>  		print_lluint(PRINT_ANY,
>  			     "mcast_query_response_intvl",
>  			     "mcast_query_response_interval %llu ",
> -			     rta_getattr_u64(tb[IFLA_BR_MCAST_QUERY_RESPONSE_INTVL]));
> +			     rta_getattr_u64(tb[IFLA_BR_MCAST_QUERY_RESPONSE_INTVL]) / hz);
>  
>  	if (tb[IFLA_BR_MCAST_STARTUP_QUERY_INTVL])
>  		print_lluint(PRINT_ANY,
>  			     "mcast_startup_query_intvl",
>  			     "mcast_startup_query_interval %llu ",
> -			     rta_getattr_u64(tb[IFLA_BR_MCAST_STARTUP_QUERY_INTVL]));
> +			     rta_getattr_u64(tb[IFLA_BR_MCAST_STARTUP_QUERY_INTVL]) / hz);
>  
>  	if (tb[IFLA_BR_MCAST_STATS_ENABLED])
>  		print_uint(PRINT_ANY,
> diff --git a/man/man8/ip-link.8.in b/man/man8/ip-link.8.in
> index c6bd2c530547..efd8a877f7a3 100644
> --- a/man/man8/ip-link.8.in
> +++ b/man/man8/ip-link.8.in
> @@ -1431,9 +1431,11 @@ corresponds to the 2010 version of the HSR standard. Option "1" activates the
>  BRIDGE Type Support
>  For a link of type
>  .I BRIDGE
> -the following additional arguments are supported:
> +the following additional arguments are supported. Note that by default time-related options are scaled by USER_HZ (100), use -h[uman] argument to convert them from seconds when
> +setting and to seconds when using show.
> +
>  
> -.BI "ip link add " DEVICE " type bridge "
> +.BI "ip [-human] link add " DEVICE " type bridge "
>  [
>  .BI ageing_time " AGEING_TIME "
>  ] [
> @@ -1523,21 +1525,22 @@ address format, ie an address of the form 01:80:C2:00:00:0X, with X
>   in [0, 4..f].
>  
>  .BI forward_delay " FORWARD_DELAY "
> -- set the forwarding delay in seconds, ie the time spent in LISTENING
> +- set the forwarding delay, ie the time spent in LISTENING
>  state (before moving to LEARNING) and in LEARNING state (before
>  moving to FORWARDING). Only relevant if STP is enabled. Valid values
> -are between 2 and 30.
> +when -h[uman] is used (in seconds) are between 2 and 30.
>  
>  .BI hello_time " HELLO_TIME "
> -- set the time in seconds between hello packets sent by the bridge,
> -when it is a root bridge or a designated bridges.
> -Only relevant if STP is enabled. Valid values are between 1 and 10.
> +- set the time between hello packets sent by the bridge, when
> +it is a root bridge or a designated bridges.
> +Only relevant if STP is enabled. Valid values when -h[uman] is used
> +(in seconds) are between 1 and 10.
>  
>  .BI max_age " MAX_AGE "
>  - set the hello packet timeout, ie the time in seconds until another
>  bridge in the spanning tree is assumed to be dead, after reception of
>  its last hello message. Only relevant if STP is enabled. Valid values
> -are between 6 and 40.
> +when -h[uman] is used (in seconds) are between 6 and 40.
>  
>  .BI stp_state " STP_STATE "
>  - turn spanning tree protocol on
> @@ -1619,7 +1622,7 @@ IGMP querier, ie sending of multicast queries by the bridge (default: disabled).
>  after this delay has passed, the bridge will start to send its own queries
>  (as if
>  .BI mcast_querier
> -was enabled).
> +was enabled). When -h[uman] is used the value will be interpreted as seconds.
>  
>  .BI mcast_hash_elasticity " HASH_ELASTICITY "
>  - set multicast database hash elasticity, ie the maximum chain length
> @@ -1636,25 +1639,29 @@ message has been received (defaults to 2).
>  
>  .BI mcast_last_member_interval " LAST_MEMBER_INTERVAL "
>  - interval between queries to find remaining members of a group,
> -after a "leave" message is received.
> +after a "leave" message is received. When -h[uman] is used the value
> +will be interpreted as seconds.
>  
>  .BI mcast_startup_query_count " STARTUP_QUERY_COUNT "
>  - set the number of IGMP queries to send during startup phase (defaults to 2).
>  
>  .BI mcast_startup_query_interval " STARTUP_QUERY_INTERVAL "
> -- interval between queries in the startup phase.
> +- interval between queries in the startup phase. When -h[uman] is used the
> +value will be interpreted as seconds.
>  
>  .BI mcast_query_interval " QUERY_INTERVAL "
>  - interval between queries sent by the bridge after the end of the
> -startup phase.
> +startup phase. When -h[uman] is used the value will be interpreted as seconds.
>  
>  .BI mcast_query_response_interval " QUERY_RESPONSE_INTERVAL "
>  - set the Max Response Time/Maximum Response Delay for IGMP/MLD
> -queries sent by the bridge.
> +queries sent by the bridge. When -h[uman] is used the value will
> +be interpreted as seconds.
>  
>  .BI mcast_membership_interval " MEMBERSHIP_INTERVAL "
>  - delay after which the bridge will leave a group,
>  if no membership reports for this group are received.
> +When -h[uman] is used the value will be interpreted as seconds.
>  
>  .BI mcast_stats_enabled " MCAST_STATS_ENABLED "
>  - enable
> -- 
> 2.25.4
> 

Thanks,
-Vladimir