BSD 4_3_Reno release

[unix-history] / usr / src / sys / kern / uipc_mbuf.c

diff --git a/usr/src/sys/kern/uipc_mbuf.c b/usr/src/sys/kern/uipc_mbuf.c
index a7a0e55..ba17d3f 100644 (file)
--- a/usr/src/sys/kern/uipc_mbuf.c
+++ b/usr/src/sys/kern/uipc_mbuf.c
@@ -1,44 +1,51 @@
 /*
 /*

+ * Copyright (c) 1982, 1986, 1988 Regents of the University of California.

  * All rights reserved.
  *
  * All rights reserved.
  *

- * Redistribution and use in source and binary forms are permitted
- * provided that this notice is preserved and that due credit is given
- * to the University of California at Berkeley. The name of the University
- * may not be used to endorse or promote products derived from this
- * software without specific prior written permission. This software
- * is provided ``as is'' without express or implied warranty.
+ * Redistribution is only permitted until one year after the first shipment
+ * of 4.4BSD by the Regents.  Otherwise, redistribution and use in source and
+ * binary forms are permitted provided that: (1) source distributions retain
+ * this entire copyright notice and comment, and (2) distributions including
+ * binaries display the following acknowledgement:  This product includes
+ * software developed by the University of California, Berkeley and its
+ * contributors'' in the documentation or other materials provided with the
+ * distribution and in all advertising materials mentioning features or use
+ * of this software.  Neither the name of the University nor the names of
+ * its contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ * THIS SOFTWARE IS PROVIDED AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

  *
  *

- *     @(#)uipc_mbuf.c 7.9 (Berkeley) %G%
+ *     @(#)uipc_mbuf.c 7.17 (Berkeley) 7/25/90

  */
 
  */
 

-#include "../machine/pte.h"
-

 #include "param.h"
 #include "param.h"

-#include "dir.h"

 #include "user.h"
 #include "proc.h"
 #include "cmap.h"
 #include "user.h"
 #include "proc.h"
 #include "cmap.h"

+#include "malloc.h"

 #include "map.h"
 #include "map.h"

+#define MBTYPES

 #include "mbuf.h"
 #include "vm.h"
 #include "kernel.h"
 #include "syslog.h"
 #include "domain.h"
 #include "protosw.h"
 #include "mbuf.h"
 #include "vm.h"
 #include "kernel.h"
 #include "syslog.h"
 #include "domain.h"
 #include "protosw.h"

+#include "machine/pte.h"

 
 mbinit()
 {
        int s;
 
 
 mbinit()
 {
        int s;
 

-#if CLBYTES < 4096
+#if MCLBYTES < 4096

 #define NCL_INIT       (4096/CLBYTES)
 #else
 #define NCL_INIT       1
 #endif
        s = splimp();
 #define NCL_INIT       (4096/CLBYTES)
 #else
 #define NCL_INIT       1
 #endif
        s = splimp();

-       if (m_clalloc(NCL_INIT, MPG_MBUFS, M_DONTWAIT) == 0)
-               goto bad;
-       if (m_clalloc(NCL_INIT, MPG_CLUSTERS, M_DONTWAIT) == 0)
+       if (m_clalloc(NCL_INIT, M_DONTWAIT) == 0)

                goto bad;
        splx(s);
        return;
                goto bad;
        splx(s);
        return;


@@ -47,16 +54,16 @@ bad:
 }
 
 /*
 }
 
 /*

+ * Allocate some number of mbuf clusters
+ * and place on cluster free list.

  * Must be called at splimp.
  */
 /* ARGSUSED */
  * Must be called at splimp.
  */
 /* ARGSUSED */

-caddr_t
-m_clalloc(ncl, how, canwait)
+m_clalloc(ncl, canwait)

        register int ncl;
        register int ncl;

-       int how;

 {
        int npg, mbx;
 {
        int npg, mbx;

-       register struct mbuf *m;
+       register caddr_t p;

        register int i;
        static int logged;
 
        register int i;
        static int logged;
 


@@ -69,67 +76,69 @@ m_clalloc(ncl, how, canwait)
                }
                return (0);
        }
                }
                return (0);
        }

-       m = cltom(mbx * NBPG / MCLBYTES);
+       p = cltom(mbx * NBPG / MCLBYTES);

        if (memall(&Mbmap[mbx], npg, proc, CSYS) == 0) {
                rmfree(mbmap, (long)npg, (long)mbx);
                return (0);
        }
        if (memall(&Mbmap[mbx], npg, proc, CSYS) == 0) {
                rmfree(mbmap, (long)npg, (long)mbx);
                return (0);
        }

-       vmaccess(&Mbmap[mbx], (caddr_t)m, npg);
-       switch (how) {
-
-       case MPG_CLUSTERS:
-               ncl = ncl * CLBYTES / MCLBYTES;
-               for (i = 0; i < ncl; i++) {
-                       m->m_off = 0;
-                       m->m_next = mclfree;
-                       mclfree = m;
-                       m += MCLBYTES / sizeof (*m);
-                       mbstat.m_clfree++;
-               }
-               mbstat.m_clusters += ncl;
-               break;
-
-       case MPG_MBUFS:
-               for (i = ncl * CLBYTES / sizeof (*m); i > 0; i--) {
-                       m->m_off = 0;
-                       m->m_type = MT_DATA;
-                       mbstat.m_mtypes[MT_DATA]++;
-                       mbstat.m_mbufs++;
-                       (void) m_free(m);
-                       m++;
-               }
-               break;
+       vmaccess(&Mbmap[mbx], p, npg);
+       ncl = ncl * CLBYTES / MCLBYTES;
+       for (i = 0; i < ncl; i++) {
+               ((union mcluster *)p)->mcl_next = mclfree;
+               mclfree = (union mcluster *)p;
+               p += MCLBYTES;
+               mbstat.m_clfree++;

        }
        }

-       return ((caddr_t)m);
+       mbstat.m_clusters += ncl;
+       return (1);

 }
 
 /*
 }
 
 /*

- * Must be called at splimp.
+ * When MGET failes, ask protocols to free space when short of memory,
+ * then re-attempt to allocate an mbuf.

  */
  */

-m_expand(canwait)
-       int canwait;
+struct mbuf *
+m_retry(i, t)
+       int i, t;
+{
+       register struct mbuf *m;
+
+       m_reclaim();
+#define m_retry(i, t)  (struct mbuf *)0
+       MGET(m, i, t);
+#undef m_retry
+       return (m);
+}
+
+/*
+ * As above; retry an MGETHDR.
+ */
+struct mbuf *
+m_retryhdr(i, t)
+       int i, t;
+{
+       register struct mbuf *m;
+
+       m_reclaim();
+#define m_retryhdr(i, t) (struct mbuf *)0
+       MGETHDR(m, i, t);
+#undef m_retryhdr
+       return (m);
+}
+
+m_reclaim()

 {
        register struct domain *dp;
        register struct protosw *pr;
 {
        register struct domain *dp;
        register struct protosw *pr;

-       int tries;
-
-       for (tries = 0;; ) {
-               if (m_clalloc(1, MPG_MBUFS, canwait))
-                       return (1);
-               if (canwait == 0 || tries++)
-                       return (0);
-
-               /* ask protocols to free space */
-               for (dp = domains; dp; dp = dp->dom_next)
-                       for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW;
-                           pr++)
-                               if (pr->pr_drain)
-                                       (*pr->pr_drain)();
-               mbstat.m_drain++;
-       }
-}
+       int s = splimp();

 
 

-/* NEED SOME WAY TO RELEASE SPACE */
+       for (dp = domains; dp; dp = dp->dom_next)
+               for (pr = dp->dom_protosw; pr < dp->dom_protoswNPROTOSW; pr++)
+                       if (pr->pr_drain)
+                               (*pr->pr_drain)();
+       splx(s);
+       mbstat.m_drain++;
+}

 
 /*
  * Space allocation routines.
 
 /*
  * Space allocation routines.


@@ -146,6 +155,16 @@ m_get(canwait, type)
        return (m);
 }
 
        return (m);
 }
 

+struct mbuf *
+m_gethdr(canwait, type)
+       int canwait, type;
+{
+       register struct mbuf *m;
+
+       MGETHDR(m, canwait, type);
+       return (m);
+}
+

 struct mbuf *
 m_getclr(canwait, type)
        int canwait, type;
 struct mbuf *
 m_getclr(canwait, type)
        int canwait, type;


@@ -169,48 +188,16 @@ m_free(m)
        return (n);
 }
 
        return (n);
 }
 

-/*
- * Get more mbufs; called from MGET macro if mfree list is empty.
- * Must be called at splimp.
- */
-/*ARGSUSED*/
-struct mbuf *
-m_more(canwait, type)
-       int canwait, type;
-{
-       register struct mbuf *m;
-
-       while (m_expand(canwait) == 0) {
-               if (canwait == M_WAIT) {
-                       mbstat.m_wait++;
-                       m_want++;
-                       sleep((caddr_t)&mfree, PZERO - 1);
-                       if (mfree)
-                               break;
-               } else {
-                       mbstat.m_drops++;
-                       return (NULL);
-               }
-       }
-#define m_more(x,y) (panic("m_more"), (struct mbuf *)0)
-       MGET(m, canwait, type);
-#undef m_more
-       return (m);
-}
-

 m_freem(m)
        register struct mbuf *m;
 {
        register struct mbuf *n;
 m_freem(m)
        register struct mbuf *m;
 {
        register struct mbuf *n;

-       register int s;

 
        if (m == NULL)
                return;
 
        if (m == NULL)
                return;

-       s = splimp();

        do {
                MFREE(m, n);
        } while (m = n);
        do {
                MFREE(m, n);
        } while (m = n);

-       splx(s);

 }
 
 /*
 }
 
 /*


@@ -218,27 +205,59 @@ m_freem(m)
  */
 
 /*
  */
 
 /*

+ * Lesser-used path for M_PREPEND:
+ * allocate new mbuf to prepend to chain,
+ * copy junk along.
+ */
+struct mbuf *
+m_prepend(m, len, how)
+       register struct mbuf *m;
+       int len, how;
+{
+       struct mbuf *mn;
+
+       MGET(mn, how, m->m_type);
+       if (mn == (struct mbuf *)NULL) {
+               m_freem(m);
+               return ((struct mbuf *)NULL);
+       }
+       if (m->m_flags & M_PKTHDR) {
+               M_COPY_PKTHDR(mn, m);
+               m->m_flags &= ~M_PKTHDR;
+       }
+       mn->m_next = m;
+       m = mn;
+       if (len < MHLEN)
+               MH_ALIGN(m, len);
+       m->m_len = len;
+       return (m);
+}
+

 /*
 /*

- * Make a copy of an mbuf chain starting "off" bytes from the beginning,
+ * Make a copy of an mbuf chain starting "off0" bytes from the beginning,

  * continuing for "len" bytes.  If len is M_COPYALL, copy to end of mbuf.
  * continuing for "len" bytes.  If len is M_COPYALL, copy to end of mbuf.

- * Should get M_WAIT/M_DONTWAIT from caller.
+ * The wait parameter is a choice of M_WAIT/M_DONTWAIT from caller.

  */
  */

+int MCFail;
+

 struct mbuf *
 struct mbuf *

-m_copy(m, off, len)
+m_copym(m, off0, len, wait)

        register struct mbuf *m;
        register struct mbuf *m;

-       int off;
+       int off0, wait;

        register int len;
 {
        register struct mbuf *n, **np;
        register int len;
 {
        register struct mbuf *n, **np;

-       struct mbuf *top, *p;
+       register int off = off0;
+       struct mbuf *top;
+       int copyhdr = 0;

 
 

-       if (len == 0)
-               return (0);

        if (off < 0 || len < 0)
        if (off < 0 || len < 0)

-               panic("m_copy");
+               panic("m_copym");
+       if (off == 0 && m->m_flags & M_PKTHDR)
+               copyhdr = 1;

        while (off > 0) {
                if (m == 0)
        while (off > 0) {
                if (m == 0)

-                       panic("m_copy");
+                       panic("m_copym");

                if (off < m->m_len)
                        break;
                off -= m->m_len;
                if (off < m->m_len)
                        break;
                off -= m->m_len;


@@ -249,18 +268,27 @@ m_copy(m, off, len)
        while (len > 0) {
                if (m == 0) {
                        if (len != M_COPYALL)
        while (len > 0) {
                if (m == 0) {
                        if (len != M_COPYALL)

-                               panic("m_copy");
+                               panic("m_copym");

                        break;
                }
                        break;
                }

-               MGET(n, M_DONTWAIT, m->m_type);
+               MGET(n, wait, m->m_type);

                *np = n;
                if (n == 0)
                        goto nospace;
                *np = n;
                if (n == 0)
                        goto nospace;

+               if (copyhdr) {
+                       M_COPY_PKTHDR(n, m);
+                       if (len == M_COPYALL)
+                               n->m_pkthdr.len -= off0;
+                       else
+                               n->m_pkthdr.len = len;
+                       copyhdr = 0;
+               }

                n->m_len = MIN(len, m->m_len - off);
                n->m_len = MIN(len, m->m_len - off);

-               if (m->m_off > MMAXOFF) {
-                       p = mtod(m, struct mbuf *);
-                       n->m_off = ((int)p - (int)n) + off;
-                       mclrefcnt[mtocl(p)]++;
+               if (m->m_flags & M_EXT) {
+                       n->m_data = m->m_data + off;
+                       mclrefcnt[mtocl(m->m_ext.ext_buf)]++;
+                       n->m_ext = m->m_ext;
+                       n->m_flags |= M_EXT;

                } else
                        bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t),
                            (unsigned)n->m_len);
                } else
                        bcopy(mtod(m, caddr_t)+off, mtod(n, caddr_t),
                            (unsigned)n->m_len);


@@ -270,9 +298,12 @@ m_copy(m, off, len)
                m = m->m_next;
                np = &n->m_next;
        }
                m = m->m_next;
                np = &n->m_next;
        }

+       if (top == 0)
+               MCFail++;

        return (top);
 nospace:
        m_freem(top);
        return (top);
 nospace:
        m_freem(top);

+       MCFail++;

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


@@ -310,14 +341,19 @@ m_copydata(m, off, len, cp)
        }
 }
 
        }
 }
 

+/*
+ * Concatenate mbuf chain n to m.
+ * Both chains must be of the same type (e.g. MT_DATA).
+ * Any m_pkthdr is not updated.
+ */

 m_cat(m, n)
        register struct mbuf *m, *n;
 {
        while (m->m_next)
                m = m->m_next;
        while (n) {
 m_cat(m, n)
        register struct mbuf *m, *n;
 {
        while (m->m_next)
                m = m->m_next;
        while (n) {

-               if (m->m_off >= MMAXOFF ||
-                   m->m_off + m->m_len + n->m_len > MMAXOFF) {
+               if (m->m_flags & M_EXT ||
+                   m->m_data + m->m_len + n->m_len >= &m->m_dat[MLEN]) {

                        /* just join the two chains */
                        m->m_next = n;
                        return;
                        /* just join the two chains */
                        m->m_next = n;
                        return;


@@ -330,16 +366,19 @@ m_cat(m, n)
        }
 }
 
        }
 }
 

-m_adj(mp, len)
+m_adj(mp, req_len)

        struct mbuf *mp;
        struct mbuf *mp;

-       register int len;

 {
 {

+       register int len = req_len;

        register struct mbuf *m;
        register count;
 
        if ((m = mp) == NULL)
                return;
        if (len >= 0) {
        register struct mbuf *m;
        register count;
 
        if ((m = mp) == NULL)
                return;
        if (len >= 0) {

+               /*
+                * Trim from head.
+                */

                while (m != NULL && len > 0) {
                        if (m->m_len <= len) {
                                len -= m->m_len;
                while (m != NULL && len > 0) {
                        if (m->m_len <= len) {
                                len -= m->m_len;


@@ -347,10 +386,13 @@ m_adj(mp, len)
                                m = m->m_next;
                        } else {
                                m->m_len -= len;
                                m = m->m_next;
                        } else {
                                m->m_len -= len;

-                               m->m_off += len;
-                               break;
+                               m->m_data += len;
+                               len = 0;

                        }
                }
                        }
                }

+               m = mp;
+               if (mp->m_flags & M_PKTHDR)
+                       m->m_pkthdr.len -= (req_len - len);

        } else {
                /*
                 * Trim from tail.  Scan the mbuf chain,
        } else {
                /*
                 * Trim from tail.  Scan the mbuf chain,


@@ -369,15 +411,22 @@ m_adj(mp, len)
                }
                if (m->m_len >= len) {
                        m->m_len -= len;
                }
                if (m->m_len >= len) {
                        m->m_len -= len;

+                       if ((mp = m)->m_flags & M_PKTHDR)
+                               m->m_pkthdr.len -= len;

                        return;
                }
                count -= len;
                        return;
                }
                count -= len;

+               if (count < 0)
+                       count = 0;

                /*
                 * Correct length for chain is "count".
                 * Find the mbuf with last data, adjust its length,
                 * and toss data from remaining mbufs on chain.
                 */
                /*
                 * Correct length for chain is "count".
                 * Find the mbuf with last data, adjust its length,
                 * and toss data from remaining mbufs on chain.
                 */

-               for (m = mp; m; m = m->m_next) {
+               m = mp;
+               if (m->m_flags & M_PKTHDR)
+                       m->m_pkthdr.len = count;
+               for (; m; m = m->m_next) {

                        if (m->m_len >= count) {
                                m->m_len = count;
                                break;
                        if (m->m_len >= count) {
                                m->m_len = count;
                                break;


@@ -394,9 +443,11 @@ m_adj(mp, len)
  * and in the data area of an mbuf (so that mtod and dtom
  * will work for a structure of size len).  Returns the resulting
  * mbuf chain on success, frees it and returns null on failure.
  * and in the data area of an mbuf (so that mtod and dtom
  * will work for a structure of size len).  Returns the resulting
  * mbuf chain on success, frees it and returns null on failure.

- * If there is room, it will add up to MPULL_EXTRA bytes to the
+ * If there is room, it will add up to max_protohdr-len extra bytes to the

  * contiguous region in an attempt to avoid being called next time.
  */
  * contiguous region in an attempt to avoid being called next time.
  */

+int MPFail;
+

 struct mbuf *
 m_pullup(n, len)
        register struct mbuf *n;
 struct mbuf *
 m_pullup(n, len)
        register struct mbuf *n;


@@ -406,28 +457,41 @@ m_pullup(n, len)
        register int count;
        int space;
 
        register int count;
        int space;
 

-       if (n->m_off + len <= MMAXOFF && n->m_next) {
+       /*
+        * If first mbuf has no cluster, and has room for len bytes
+        * without shifting current data, pullup into it,
+        * otherwise allocate a new mbuf to prepend to the chain.
+        */
+       if ((n->m_flags & M_EXT) == 0 &&
+           n->m_data + len < &n->m_dat[MLEN] && n->m_next) {
+               if (n->m_len >= len)
+                       return (n);

                m = n;
                n = n->m_next;
                len -= m->m_len;
        } else {
                m = n;
                n = n->m_next;
                len -= m->m_len;
        } else {

-               if (len > MLEN)
+               if (len > MHLEN)

                        goto bad;
                MGET(m, M_DONTWAIT, n->m_type);
                if (m == 0)
                        goto bad;
                m->m_len = 0;
                        goto bad;
                MGET(m, M_DONTWAIT, n->m_type);
                if (m == 0)
                        goto bad;
                m->m_len = 0;

+               if (n->m_flags & M_PKTHDR) {
+                       M_COPY_PKTHDR(m, n);
+                       n->m_flags &= ~M_PKTHDR;
+               }

        }
        }

-       space = MMAXOFF - m->m_off;
+       space = &m->m_dat[MLEN] - (m->m_data + m->m_len);

        do {
        do {

-               count = MIN(MIN(space - m->m_len, len + MPULL_EXTRA), n->m_len);
-               bcopy(mtod(n, caddr_t), mtod(m, caddr_t)+m->m_len,
+               count = min(min(max(len, max_protohdr), space), n->m_len);
+               bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len,

                  (unsigned)count);
                len -= count;
                m->m_len += count;
                n->m_len -= count;
                  (unsigned)count);
                len -= count;
                m->m_len += count;
                n->m_len -= count;

+               space -= count;

                if (n->m_len)
                if (n->m_len)

-                       n->m_off += count;
+                       n->m_data += count;

                else
                        n = m_free(n);
        } while (len > 0 && n);
                else
                        n = m_free(n);
        } while (len > 0 && n);


@@ -439,5 +503,6 @@ m_pullup(n, len)
        return (m);
 bad:
        m_freem(n);
        return (m);
 bad:
        m_freem(n);

+       MPFail++;

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