As per the Open vSwitch Manual
(http://www.openvswitch.org/support/dist-docs/ovs-vsctl.8.txt) the Bridge IPFIX
parameters can be passed as follows:
ovs-vsctl -- set Bridge br0 ipfix=@i \
-- --id=@i create IPFIX targets=\"192.168.0.34:4739\" obs_do‐
main_id=123 obs_point_id=456 cache_active_timeout=60
cache_max_flows=13 \
other_config:enable-input-sampling=false \
other_config:enable-output-sampling=false \
other_config:enable-tunnel-sampling=true
where the default values are:
enable_input_sampling: true
enable_output_sampling: true
enable_tunnel_sampling: false
But in the existing code
https://github.com/openvswitch/ovs/blob/master/vswitchd/bridge.c#L1560-L1567,
these 3 parameters take up unexpected values in some scenarios.
Consider the following case for enable_input_sampling and
enable_output_sampling:
be_opts.enable_input_sampling = !smap_get_bool(&be_cfg->other_config,
"enable-input-sampling", false);
be_opts.enable_output_sampling = !smap_get_bool(&be_cfg->other_config,
"enable-output-sampling", false);
Here, the function smap_get_bool is being used with a negation.
smap_get_bool is defined as below:
(https://github.com/openvswitch/ovs/blob/master/lib/smap.c#L220-L232)
/* Gets the value associated with 'key' in 'smap' and converts it to a boolean.
* If 'key' is not in 'smap', or its value is neither "true" nor "false",
* returns 'def'. */
bool
smap_get_bool(const struct smap *smap, const char *key, bool def)
{
const char *value = smap_get_def(smap, key, "");
if (def) {
return strcasecmp("false", value) != 0;
} else {
return !strcasecmp("true", value);
}
}
This returns expected values for the default case (since the above code will
negate “false” we get from smap_get bool function and return the value “true”)
but unexpected values for the case where the sampling value is passed through
the CLI.
For example, if we pass "true" for other_config:enable-input-sampling in the
CLI, the above code will negate the “true” value we get from the smap_bool
function and return the value “false”. Same would be the case for
enable_output_sampling.
My proposed solution is as below:
be_opts.enable_input_sampling = smap_get_bool(&be_cfg->other_config,
"enable-input-sampling", true);
be_opts.enable_output_sampling = smap_get_bool(&be_cfg->other_config,
"enable-output-sampling", true);
Here, by removing the negation on the smap_get bool function, we make sure the
CLI value is returned as expected and by changing the 3rd parameter to “true”,
we return the default value “true” as expected.
Now, consider the following case for enable_tunnel_sampling:
be_opts.enable_tunnel_sampling = smap_get_bool(&be_cfg->other_config,
"enable-tunnel-sampling", true);
Here again the smap_get_bool function is being used (without a negation).
This returns unexpected value for the default case (since expected value is
false and smap_get_bool function will return true) and expected value for the
case where the sampling value is passed through the CLI.
My proposed solution is as below:
be_opts.enable_tunnel_sampling = smap_get_bool(&be_cfg->other_config,
"enable-tunnel-sampling", false);
Here, by changing the 3rd parameter to “false”, we return the default value
“false” as expected.
I am happy to discuss more if there are any additional thoughts around this.
If this looks like a good fix, I can go ahead and send out a PR for review.
Thanks & Regards,
Sayali Naval
_______________________________________________
dev mailing list
[email protected]
https://mail.openvswitch.org/mailman/listinfo/ovs-dev
