1/*! NOTE: Most kern_mbuf functions are implemented by our mbuf.c; however,
2 *  a certain few non-allocation-related ones which we can copy wholesale
3 *  from FreeBSD live here. */
4/*-
5 * Copyright (c) 2004, 2005,
6 *	Bosko Milekic <bmilekic@FreeBSD.org>.  All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice unmodified, this list of conditions and the following
13 *    disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31#include <sys/cdefs.h>
32#include <sys/mbuf.h>
33
34/*
35 * Allocate a given length worth of mbufs and/or clusters (whatever fits
36 * best) and return a pointer to the top of the allocated chain.  If an
37 * existing mbuf chain is provided, then we will append the new chain
38 * to the existing one but still return the top of the newly allocated
39 * chain.
40 */
41struct mbuf *
42m_getm2(struct mbuf *m, int len, int how, short type, int flags)
43{
44	struct mbuf *mb, *nm = NULL, *mtail = NULL;
45
46	KASSERT(len >= 0, ("%s: len is < 0", __func__));
47
48	/* Validate flags. */
49	flags &= (M_PKTHDR | M_EOR);
50
51	/* Packet header mbuf must be first in chain. */
52	if ((flags & M_PKTHDR) && m != NULL)
53		flags &= ~M_PKTHDR;
54
55	/* Loop and append maximum sized mbufs to the chain tail. */
56	while (len > 0) {
57		if (len > MCLBYTES)
58			mb = m_getjcl(how, type, (flags & M_PKTHDR),
59			    MJUMPAGESIZE);
60		else if (len >= MINCLSIZE)
61			mb = m_getcl(how, type, (flags & M_PKTHDR));
62		else if (flags & M_PKTHDR)
63			mb = m_gethdr(how, type);
64		else
65			mb = m_get(how, type);
66
67		/* Fail the whole operation if one mbuf can't be allocated. */
68		if (mb == NULL) {
69			if (nm != NULL)
70				m_freem(nm);
71			return (NULL);
72		}
73
74		/* Book keeping. */
75		len -= M_SIZE(mb);
76		if (mtail != NULL)
77			mtail->m_next = mb;
78		else
79			nm = mb;
80		mtail = mb;
81		flags &= ~M_PKTHDR;	/* Only valid on the first mbuf. */
82	}
83	if (flags & M_EOR)
84		mtail->m_flags |= M_EOR;  /* Only valid on the last mbuf. */
85
86	/* If mbuf was supplied, append new chain to the end of it. */
87	if (m != NULL) {
88		for (mtail = m; mtail->m_next != NULL; mtail = mtail->m_next)
89			;
90		mtail->m_next = nm;
91		mtail->m_flags &= ~M_EOR;
92	} else
93		m = nm;
94
95	return (m);
96}
97
98/*-
99 * Configure a provided mbuf to refer to the provided external storage
100 * buffer and setup a reference count for said buffer.
101 *
102 * Arguments:
103 *    mb     The existing mbuf to which to attach the provided buffer.
104 *    buf    The address of the provided external storage buffer.
105 *    size   The size of the provided buffer.
106 *    freef  A pointer to a routine that is responsible for freeing the
107 *           provided external storage buffer.
108 *    args   A pointer to an argument structure (of any type) to be passed
109 *           to the provided freef routine (may be NULL).
110 *    flags  Any other flags to be passed to the provided mbuf.
111 *    type   The type that the external storage buffer should be
112 *           labeled with.
113 *
114 * Returns:
115 *    Nothing.
116 */
117void
118m_extadd(struct mbuf *mb, caddr_t buf, u_int size,
119    void (*freef)(struct mbuf *, void *, void *), void *arg1, void *arg2,
120    int flags, int type)
121{
122
123	KASSERT(type != EXT_CLUSTER, ("%s: EXT_CLUSTER not allowed", __func__));
124
125	mb->m_flags |= (M_EXT | flags);
126	mb->m_ext.ext_buf = buf;
127	mb->m_data = mb->m_ext.ext_buf;
128	mb->m_ext.ext_size = size;
129#ifndef __HAIKU__
130	mb->m_ext.ext_free = freef;
131	mb->m_ext.ext_arg1 = arg1;
132	mb->m_ext.ext_arg2 = arg2;
133#else
134	if (freef != NULL)
135		panic("m_ext.ext_free not yet implemented");
136#endif
137	mb->m_ext.ext_type = type;
138
139	if (type != EXT_EXTREF) {
140		mb->m_ext.ext_count = 1;
141		mb->m_ext.ext_flags = EXT_FLAG_EMBREF;
142	} else
143		mb->m_ext.ext_flags = 0;
144}
145
146/*
147 * Free an entire chain of mbufs and associated external buffers, if
148 * applicable.
149 */
150void
151m_freem(struct mbuf *mb)
152{
153	while (mb != NULL)
154		mb = m_free(mb);
155}
156