register struct mbuf *m, *mn;
struct mbuf *m, *mn;
sbdrop(sb, len)	register struct sockbuf *sb;	register int len;{	register struct mbuf *m, *mn;	struct mbuf *next;	next = (m = sb->sb_mb) ? m->m_nextpkt : 0;	while (len > 0) {		if (m == 0) {			if (next == 0)				panic("sbdrop");			m = next;			next = m->m_nextpkt;			continue;		}		if (m->m_len > len) {			m->m_len -= len;			m->m_data += len;			sb->sb_cc -= len;			break;		}		len -= m->m_len;		sbfree(sb, m);		MFREE(m, mn);		m = mn;	}	while (m && m->m_len == 0) {		sbfree(sb, m);		MFREE(m, mn);		m = mn;	}	if (m) {		sb->sb_mb = m;		m->m_nextpkt = next;	} else		sb->sb_mb = next;}