c1e968fb62
Since the uset can set dhcp.interface-mtu, we need to try to validate the value. So we verify if the conversion to int is successful and we will not allow to set value greater than max IPv4 packet size. Also use snprintf for safety. Reviewed by: allanjude, bapt Approved by: allanjude (mentor) Differential Revision: https://reviews.freebsd.org/D8492