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-rw-r--r--sys/kern/uipc_mbuf.c655
1 files changed, 655 insertions, 0 deletions
diff --git a/sys/kern/uipc_mbuf.c b/sys/kern/uipc_mbuf.c
new file mode 100644
index 0000000..b71c634
--- /dev/null
+++ b/sys/kern/uipc_mbuf.c
@@ -0,0 +1,655 @@
+/*
+ * Copyright (c) 1982, 1986, 1988, 1991, 1993
+ * The Regents of the University of California. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by the University of
+ * California, Berkeley and its contributors.
+ * 4. 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 BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * @(#)uipc_mbuf.c 8.2 (Berkeley) 1/4/94
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/proc.h>
+#include <sys/malloc.h>
+#include <sys/map.h>
+#define MBTYPES
+#include <sys/mbuf.h>
+#include <sys/kernel.h>
+#include <sys/syslog.h>
+#include <sys/domain.h>
+#include <sys/protosw.h>
+
+#include <vm/vm.h>
+
+extern vm_map_t mb_map;
+struct mbuf *mbutl;
+char *mclrefcnt;
+
+mbinit()
+{
+ int s;
+
+#if CLBYTES < 4096
+#define NCL_INIT (4096/CLBYTES)
+#else
+#define NCL_INIT 1
+#endif
+ s = splimp();
+ if (m_clalloc(NCL_INIT, M_DONTWAIT) == 0)
+ goto bad;
+ splx(s);
+ return;
+bad:
+ panic("mbinit");
+}
+
+/*
+ * Allocate some number of mbuf clusters
+ * and place on cluster free list.
+ * Must be called at splimp.
+ */
+/* ARGSUSED */
+m_clalloc(ncl, nowait)
+ register int ncl;
+ int nowait;
+{
+ static int logged;
+ register caddr_t p;
+ register int i;
+ int npg;
+
+ npg = ncl * CLSIZE;
+ p = (caddr_t)kmem_malloc(mb_map, ctob(npg), !nowait);
+ if (p == NULL) {
+ if (logged == 0) {
+ logged++;
+ log(LOG_ERR, "mb_map full\n");
+ }
+ return (0);
+ }
+ 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++;
+ }
+ mbstat.m_clusters += ncl;
+ return (1);
+}
+
+/*
+ * When MGET failes, ask protocols to free space when short of memory,
+ * then re-attempt to allocate an mbuf.
+ */
+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;
+ int s = splimp();
+
+ 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.
+ * These are also available as macros
+ * for critical paths.
+ */
+struct mbuf *
+m_get(nowait, type)
+ int nowait, type;
+{
+ register struct mbuf *m;
+
+ MGET(m, nowait, type);
+ return (m);
+}
+
+struct mbuf *
+m_gethdr(nowait, type)
+ int nowait, type;
+{
+ register struct mbuf *m;
+
+ MGETHDR(m, nowait, type);
+ return (m);
+}
+
+struct mbuf *
+m_getclr(nowait, type)
+ int nowait, type;
+{
+ register struct mbuf *m;
+
+ MGET(m, nowait, type);
+ if (m == 0)
+ return (0);
+ bzero(mtod(m, caddr_t), MLEN);
+ return (m);
+}
+
+struct mbuf *
+m_free(m)
+ struct mbuf *m;
+{
+ register struct mbuf *n;
+
+ MFREE(m, n);
+ return (n);
+}
+
+void
+m_freem(m)
+ register struct mbuf *m;
+{
+ register struct mbuf *n;
+
+ if (m == NULL)
+ return;
+ do {
+ MFREE(m, n);
+ } while (m = n);
+}
+
+/*
+ * Mbuffer utility routines.
+ */
+
+/*
+ * 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 "off0" bytes from the beginning,
+ * continuing for "len" bytes. If len is M_COPYALL, copy to end of mbuf.
+ * The wait parameter is a choice of M_WAIT/M_DONTWAIT from caller.
+ */
+int MCFail;
+
+struct mbuf *
+m_copym(m, off0, len, wait)
+ register struct mbuf *m;
+ int off0, wait;
+ register int len;
+{
+ register struct mbuf *n, **np;
+ register int off = off0;
+ struct mbuf *top;
+ int copyhdr = 0;
+
+ if (off < 0 || len < 0)
+ panic("m_copym");
+ if (off == 0 && m->m_flags & M_PKTHDR)
+ copyhdr = 1;
+ while (off > 0) {
+ if (m == 0)
+ panic("m_copym");
+ if (off < m->m_len)
+ break;
+ off -= m->m_len;
+ m = m->m_next;
+ }
+ np = &top;
+ top = 0;
+ while (len > 0) {
+ if (m == 0) {
+ if (len != M_COPYALL)
+ panic("m_copym");
+ break;
+ }
+ MGET(n, wait, m->m_type);
+ *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);
+ 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);
+ if (len != M_COPYALL)
+ len -= n->m_len;
+ off = 0;
+ m = m->m_next;
+ np = &n->m_next;
+ }
+ if (top == 0)
+ MCFail++;
+ return (top);
+nospace:
+ m_freem(top);
+ MCFail++;
+ return (0);
+}
+
+/*
+ * Copy data from an mbuf chain starting "off" bytes from the beginning,
+ * continuing for "len" bytes, into the indicated buffer.
+ */
+m_copydata(m, off, len, cp)
+ register struct mbuf *m;
+ register int off;
+ register int len;
+ caddr_t cp;
+{
+ register unsigned count;
+
+ if (off < 0 || len < 0)
+ panic("m_copydata");
+ while (off > 0) {
+ if (m == 0)
+ panic("m_copydata");
+ if (off < m->m_len)
+ break;
+ off -= m->m_len;
+ m = m->m_next;
+ }
+ while (len > 0) {
+ if (m == 0)
+ panic("m_copydata");
+ count = min(m->m_len - off, len);
+ bcopy(mtod(m, caddr_t) + off, cp, count);
+ len -= count;
+ cp += count;
+ off = 0;
+ m = m->m_next;
+ }
+}
+
+/*
+ * 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) {
+ 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;
+ }
+ /* splat the data from one into the other */
+ bcopy(mtod(n, caddr_t), mtod(m, caddr_t) + m->m_len,
+ (u_int)n->m_len);
+ m->m_len += n->m_len;
+ n = m_free(n);
+ }
+}
+
+m_adj(mp, req_len)
+ struct mbuf *mp;
+ int req_len;
+{
+ register int len = req_len;
+ 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;
+ m->m_len = 0;
+ m = m->m_next;
+ } else {
+ m->m_len -= len;
+ 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,
+ * calculating its length and finding the last mbuf.
+ * If the adjustment only affects this mbuf, then just
+ * adjust and return. Otherwise, rescan and truncate
+ * after the remaining size.
+ */
+ len = -len;
+ count = 0;
+ for (;;) {
+ count += m->m_len;
+ if (m->m_next == (struct mbuf *)0)
+ break;
+ m = m->m_next;
+ }
+ if (m->m_len >= len) {
+ m->m_len -= len;
+ if (mp->m_flags & M_PKTHDR)
+ mp->m_pkthdr.len -= 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.
+ */
+ 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;
+ }
+ count -= m->m_len;
+ }
+ while (m = m->m_next)
+ m->m_len = 0;
+ }
+}
+
+/*
+ * Rearange an mbuf chain so that len bytes are contiguous
+ * 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 max_protohdr-len extra bytes to the
+ * contiguous region in an attempt to avoid being called next time.
+ */
+int MPFail;
+
+struct mbuf *
+m_pullup(n, len)
+ register struct mbuf *n;
+ int len;
+{
+ register struct mbuf *m;
+ register int count;
+ int space;
+
+ /*
+ * 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 {
+ if (len > MHLEN)
+ 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 = &m->m_dat[MLEN] - (m->m_data + m->m_len);
+ do {
+ 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;
+ space -= count;
+ if (n->m_len)
+ n->m_data += count;
+ else
+ n = m_free(n);
+ } while (len > 0 && n);
+ if (len > 0) {
+ (void) m_free(m);
+ goto bad;
+ }
+ m->m_next = n;
+ return (m);
+bad:
+ m_freem(n);
+ MPFail++;
+ return (0);
+}
+
+/*
+ * Partition an mbuf chain in two pieces, returning the tail --
+ * all but the first len0 bytes. In case of failure, it returns NULL and
+ * attempts to restore the chain to its original state.
+ */
+struct mbuf *
+m_split(m0, len0, wait)
+ register struct mbuf *m0;
+ int len0, wait;
+{
+ register struct mbuf *m, *n;
+ unsigned len = len0, remain;
+
+ for (m = m0; m && len > m->m_len; m = m->m_next)
+ len -= m->m_len;
+ if (m == 0)
+ return (0);
+ remain = m->m_len - len;
+ if (m0->m_flags & M_PKTHDR) {
+ MGETHDR(n, wait, m0->m_type);
+ if (n == 0)
+ return (0);
+ n->m_pkthdr.rcvif = m0->m_pkthdr.rcvif;
+ n->m_pkthdr.len = m0->m_pkthdr.len - len0;
+ m0->m_pkthdr.len = len0;
+ if (m->m_flags & M_EXT)
+ goto extpacket;
+ if (remain > MHLEN) {
+ /* m can't be the lead packet */
+ MH_ALIGN(n, 0);
+ n->m_next = m_split(m, len, wait);
+ if (n->m_next == 0) {
+ (void) m_free(n);
+ return (0);
+ } else
+ return (n);
+ } else
+ MH_ALIGN(n, remain);
+ } else if (remain == 0) {
+ n = m->m_next;
+ m->m_next = 0;
+ return (n);
+ } else {
+ MGET(n, wait, m->m_type);
+ if (n == 0)
+ return (0);
+ M_ALIGN(n, remain);
+ }
+extpacket:
+ if (m->m_flags & M_EXT) {
+ n->m_flags |= M_EXT;
+ n->m_ext = m->m_ext;
+ mclrefcnt[mtocl(m->m_ext.ext_buf)]++;
+ m->m_ext.ext_size = 0; /* For Accounting XXXXXX danger */
+ n->m_data = m->m_data + len;
+ } else {
+ bcopy(mtod(m, caddr_t) + len, mtod(n, caddr_t), remain);
+ }
+ n->m_len = remain;
+ m->m_len = len;
+ n->m_next = m->m_next;
+ m->m_next = 0;
+ return (n);
+}
+/*
+ * Routine to copy from device local memory into mbufs.
+ */
+struct mbuf *
+m_devget(buf, totlen, off0, ifp, copy)
+ char *buf;
+ int totlen, off0;
+ struct ifnet *ifp;
+ void (*copy)();
+{
+ register struct mbuf *m;
+ struct mbuf *top = 0, **mp = &top;
+ register int off = off0, len;
+ register char *cp;
+ char *epkt;
+
+ cp = buf;
+ epkt = cp + totlen;
+ if (off) {
+ cp += off + 2 * sizeof(u_short);
+ totlen -= 2 * sizeof(u_short);
+ }
+ MGETHDR(m, M_DONTWAIT, MT_DATA);
+ if (m == 0)
+ return (0);
+ m->m_pkthdr.rcvif = ifp;
+ m->m_pkthdr.len = totlen;
+ m->m_len = MHLEN;
+
+ while (totlen > 0) {
+ if (top) {
+ MGET(m, M_DONTWAIT, MT_DATA);
+ if (m == 0) {
+ m_freem(top);
+ return (0);
+ }
+ m->m_len = MLEN;
+ }
+ len = min(totlen, epkt - cp);
+ if (len >= MINCLSIZE) {
+ MCLGET(m, M_DONTWAIT);
+ if (m->m_flags & M_EXT)
+ m->m_len = len = min(len, MCLBYTES);
+ else
+ len = m->m_len;
+ } else {
+ /*
+ * Place initial small packet/header at end of mbuf.
+ */
+ if (len < m->m_len) {
+ if (top == 0 && len + max_linkhdr <= m->m_len)
+ m->m_data += max_linkhdr;
+ m->m_len = len;
+ } else
+ len = m->m_len;
+ }
+ if (copy)
+ copy(cp, mtod(m, caddr_t), (unsigned)len);
+ else
+ bcopy(cp, mtod(m, caddr_t), (unsigned)len);
+ cp += len;
+ *mp = m;
+ mp = &m->m_next;
+ totlen -= len;
+ if (cp == epkt)
+ cp = buf;
+ }
+ return (top);
+}
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