m_pullup

SCCS-vsn: sys/kern/uipc_mbuf.c 1.25

diff --git a/usr/src/sys/kern/uipc_mbuf.c b/usr/src/sys/kern/uipc_mbuf.c
index d7cd99d..f2e9aaa 100644 (file)
--- a/usr/src/sys/kern/uipc_mbuf.c
+++ b/usr/src/sys/kern/uipc_mbuf.c
@@ -1,4 +1,4 @@
-/*     uipc_mbuf.c     1.24    81/12/21        */
+/*     uipc_mbuf.c     1.25    81/12/23        */

 
 #include "../h/param.h"
 #include "../h/dir.h"
 
 #include "../h/param.h"
 #include "../h/dir.h"


@@ -310,11 +310,42 @@ COUNT(M_ADJ);
        }
 }
 
        }
 }
 

-/*ARGSUSED*/
-m_pullup(m, len)
-       struct mbuf *m;
+struct mbuf *
+m_pullup(m0, len)
+       struct mbuf *m0;

        int len;
 {
        int len;
 {

+       register struct mbuf *m, *n;
+       int cnt;

 
 

+       if (len > MLEN)
+               goto bad;
+       MGET(m, 0);
+       if (m == 0)
+               goto bad;
+       m->m_off = MMINOFF;
+       m->m_len = 0;
+       n = m0;
+       do {
+               cnt = MIN(MLEN - m->m_len, len);
+               if (cnt > n->m_len)
+                       cnt = n->m_len;
+               bcopy(mtod(n, caddr_t), mtod(m, caddr_t)+m->m_len, cnt);
+               len -= cnt;
+               m->m_len += cnt;
+               n->m_off += cnt;
+               n->m_len -= cnt;
+               if (n->m_len)
+                       break;
+               n = m_free(n);
+       } while (n);
+       if (len) {
+               (void) m_free(m);
+               goto bad;
+       }
+       m->m_next = n;
+       return (m);
+bad:
+       m_freem(m0);

        return (0);
 }
        return (0);
 }