-/*
- * Copy data from a buffer back into the indicated mbuf chain,
- * starting "off" bytes from the beginning, extending the mbuf
- * chain if necessary.
- */
-m_copyback(m0, off, len, cp)
- struct mbuf *m0;
- register int off;
- register int len;
- caddr_t cp;
-
-{
- register int mlen;
- register struct mbuf *m = m0, *n;
- int totlen = 0;
-
- if (m0 == 0)
- return;
- while (off > (mlen = m->m_len)) {
- off -= mlen;
- totlen += mlen;
- if (m->m_next == 0) {
- n = m_getclr(M_DONTWAIT, m->m_type);
- if (n == 0)
- goto out;
- n->m_len = min(MLEN, len + off);
- m->m_next = n;
- }
- m = m->m_next;
- }
- while (len > 0) {
- mlen = min (m->m_len - off, len);
- bcopy(cp, off + mtod(m, caddr_t), (unsigned)mlen);
- cp += mlen;
- len -= mlen;
- mlen += off;
- off = 0;
- totlen += mlen;
- if (len == 0)
- break;
- if (m->m_next == 0) {
- n = m_get(M_DONTWAIT, m->m_type);
- if (n == 0)
- break;
- n->m_len = min(MLEN, len);
- m->m_next = n;
- }
- m = m->m_next;
- }
-out: if (((m = m0)->m_flags & M_PKTHDR) && (m->m_pkthdr.len < totlen))
- m->m_pkthdr.len = totlen;
-}
-