Add a way to fine tune otDatasetCreateNewNetwork results

[rretanubun]

If I understands things correctly, having the ability to pre-set the channel mask before calling otDatasetCreateNewNetwork
which maps to :

openthread/src/core/meshcop/dataset.cpp

Lines 54 to 77 in 3400692

	Error Dataset::Info::GenerateRandom(Instance &aInstance)
	{
	Error error;
	Mac::ChannelMask supportedChannels = aInstance.Get<Mac::Mac>().GetSupportedChannelMask();
	Mac::ChannelMask preferredChannels(aInstance.Get<Radio>().GetPreferredChannelMask());
	// If the preferred channel mask is not empty, select a random
	// channel from it, otherwise choose one from the supported
	// channel mask.
	preferredChannels.Intersect(supportedChannels);
	if (preferredChannels.IsEmpty())
	{
	preferredChannels = supportedChannels;
	}
	Clear();
	mActiveTimestamp.mSeconds = 1;
	mActiveTimestamp.mTicks = 0;
	mActiveTimestamp.mAuthoritative = false;
	mChannel = preferredChannels.ChooseRandomChannel();
	mChannelMask = supportedChannels.GetMask();

will allow something like this (paraphrased using some missing APIs):

otPlatRadioSetSupportedChannelMask(aNonDefaultChannelMask); // For example, limit channels to 11-to-25 to avoid 26
otDatasetCreateNewNetwork(); // The newly formed dataset is influence by the previous call and pick a random channel between 11-to-25

Or is there an existing or alternate method to achieve the same thing that I am missing?

Thanks for everyone's time!

[abtink]

@rretanubun what you say is correct.

Also want to point out that otDatasetCreateNewNetwork() will create a new dataset and return it in the given otOperationalDataset *aDataset. Caller can then change any fields in otOperationalDataset` object itself afterwards.

[rretanubun]

@abtink : Yep, I am doing what you suggested to achieve what I need for now, just wanted to optimize away the extra work with the idea. Thanks for confirming my understanding.