NO_PKT_ALLOCATED
bp->av_back = NO_PKT_ALLOCATED;
bp->av_back = NO_PKT_ALLOCATED;
bp->av_back = NO_PKT_ALLOCATED;
bp->av_back = NO_PKT_ALLOCATED;
bp->av_back = NO_PKT_ALLOCATED;
bp->av_back = NO_PKT_ALLOCATED;
bp->av_back = NO_PKT_ALLOCATED;
#define BP_HAS_NO_PKT(bp) (bp->av_back == NO_PKT_ALLOCATED)