mfilter
if (chan->mfilter)
free(chan->mfilter);
chan->mfilter = mf;
if (memcmp(pkt->dst, chan->mfilter[i].start, ETHER_ADDR_LEN) >= 0
&& memcmp(pkt->dst, chan->mfilter[i].end, ETHER_ADDR_LEN) <= 0)
typedef struct mfilter mfilter_t;
mfilter_t * mfilter;
free(chan->mfilter);