subr_module.c revision 40090 
1/*-
2 * Copyright (c) 1998 Michael Smith
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 *	$Id$
27 */
28
29#include <sys/param.h>
30#include <sys/kernel.h>
31#include <sys/systm.h>
32#include <sys/linker.h>
33
34/*
35 * Preloaded module support
36 */
37
38caddr_t	module_metadata;
39
40/*
41 * Search for the preloaded module (name)
42 */
43caddr_t
44module_search_by_name(const char *name)
45{
46    caddr_t	curp;
47    u_int32_t	*hdr;
48
49    if (module_metadata != NULL) {
50
51	curp = module_metadata;
52	for (;;) {
53	    hdr = (u_int32_t *)curp;
54	    if (hdr[0] == 0)
55		break;
56
57	    /* Search for a MODINFO_NAME field */
58	    if ((hdr[0] == MODINFO_NAME) &&
59		!strcmp(name, curp + sizeof(u_int32_t) * 2))
60		return(curp);
61
62	    /* skip to next field */
63	    curp += sizeof(u_int32_t) * 2 + hdr[1];
64	}
65    }
66    return(NULL);
67}
68
69/*
70 * Search for the first preloaded module of (type)
71 */
72caddr_t
73module_search_by_type(const char *type)
74{
75    caddr_t	curp, lname;
76    u_int32_t	*hdr;
77
78    if (module_metadata != NULL) {
79
80	curp = module_metadata;
81	lname = NULL;
82	for (;;) {
83	    hdr = (u_int32_t *)curp;
84	    if (hdr[0] == 0)
85		break;
86
87	    /* remember the start of each record */
88	    if (hdr[0] == MODINFO_NAME)
89		lname = curp;
90
91	    /* Search for a MODINFO_TYPE field */
92	    if ((hdr[0] == MODINFO_TYPE) &&
93		!strcmp(type, curp + sizeof(u_int32_t) * 2))
94		return(lname);
95
96	    /* skip to next field */
97	    curp += sizeof(u_int32_t) * 2 + hdr[1];
98	}
99    }
100    return(NULL);
101}
102
103/*
104 * Given a preloaded module handle (mod), return a pointer
105 * to the data for the attribute (inf).
106 */
107caddr_t
108module_search_info(caddr_t mod, int inf)
109{
110    caddr_t	curp;
111    u_int32_t	*hdr;
112    u_int32_t	type = 0;
113
114    curp = mod;
115    for (;;) {
116	hdr = (u_int32_t *)curp;
117	/* end of module data? */
118	if (hdr[0] == 0)
119	    break;
120	/*
121	 * We give up once we've looped back to what we were looking at
122	 * first - this should normally be a MODINFO_NAME field.
123	 */
124	if (type == 0) {
125	    type = hdr[0];
126	} else {
127	    if (hdr[0] == type)
128		break;
129	}
130
131	/*
132	 * Attribute match? Return pointer to data.
133	 * Consumer may safely assume that size value preceeds
134	 * data.
135	 */
136	if (hdr[0] == inf)
137	    return(curp + (sizeof(u_int32_t) * 2));
138
139	/* skip to next field */
140	curp += sizeof(u_int32_t) * 2 + hdr[1];
141    }
142    return(NULL);
143}
144
145