They are being arrested detained and turned over to Canada Immigration officials.  If they make a claim to refugee status then that claim will be processed.  If determined eligible then they will have an oral hearing before the Refugee Protection Division of the IRB to make their case.

The Charter and the SCOC decision in Singh v Canada (Minister of Employment and Immigration), [1985] 1 S.C.R. 177 require that refugee claimants physically in Canada have Charter rights under s. 7 and must be accorded "fundamental justice" (our version of due process).

If they are determined to not be refugees then they will be removed to their home country.