Moved m_copyback into uipc_mbuf.c

1 files changed, 54 insertions, 1 deletions

diff --git a/sys/kern/uipc_mbuf.c b/sys/kern/uipc_mbuf.c
index 0b35abb..62a648c 100644
--- a/sys/kern/uipc_mbuf.c
+++ b/sys/kern/uipc_mbuf.c
@@ -31,7 +31,7 @@
  * SUCH DAMAGE.
  *
  *	@(#)uipc_mbuf.c	8.2 (Berkeley) 1/4/94
- * $Id: uipc_mbuf.c,v 1.3 1994/08/02 07:43:02 davidg Exp $
+ * $Id: uipc_mbuf.c,v 1.4 1994/10/02 17:35:31 phk Exp $
  */
 
 #include <sys/param.h>
@@ -661,3 +661,56 @@ m_devget(buf, totlen, off0, ifp, copy)
 	}
 	return (top);
 }
+
+/*
+ * Copy data from a buffer back into the indicated mbuf chain,
+ * starting "off" bytes from the beginning, extending the mbuf
+ * chain if necessary.
+ */
+void
+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;
+}