359df778 |
1 | /* -*-c-*- |
2 | * |
b817bfc6 |
3 | * $Id: lmem.h,v 1.5 2004/04/08 01:36:15 mdw Exp $ |
359df778 |
4 | * |
5 | * Locked memory allocation |
6 | * |
7 | * (c) 1999 Straylight/Edgeware |
8 | */ |
9 | |
10 | /*----- Licensing notice --------------------------------------------------* |
11 | * |
12 | * This file is part of Catacomb. |
13 | * |
14 | * Catacomb is free software; you can redistribute it and/or modify |
15 | * it under the terms of the GNU Library General Public License as |
16 | * published by the Free Software Foundation; either version 2 of the |
17 | * License, or (at your option) any later version. |
18 | * |
19 | * Catacomb is distributed in the hope that it will be useful, |
20 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
21 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
22 | * GNU Library General Public License for more details. |
23 | * |
24 | * You should have received a copy of the GNU Library General Public |
25 | * License along with Catacomb; if not, write to the Free |
26 | * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, |
27 | * MA 02111-1307, USA. |
28 | */ |
29 | |
359df778 |
30 | #ifndef CATACOMB_LMEM_H |
31 | #define CATACOMB_LMEM_H |
32 | |
33 | #ifdef __cplusplus |
34 | extern "C" { |
35 | #endif |
36 | |
37 | /*----- Header files ------------------------------------------------------*/ |
38 | |
39 | #include <stddef.h> |
40 | |
47d5f7c2 |
41 | #include <mLib/arena.h> |
359df778 |
42 | #include <mLib/dstr.h> |
43 | |
44 | /*----- Data structures ---------------------------------------------------*/ |
45 | |
46 | /* --- Block list --- * |
47 | * |
48 | * The block list is kept in normal memory, to avoid wasting precious locked |
49 | * memory. Entries are sorted into ascending address order to make |
50 | * coalescing free blocks easier. All blocks, free or not, are included in |
51 | * the list. |
52 | */ |
53 | |
54 | typedef struct l_node { |
55 | struct l_node *next; /* Next free block in chain */ |
56 | char *p; /* Pointer to the block */ |
57 | size_t sz; /* Size of the block */ |
58 | unsigned f; /* Various flags */ |
59 | } l_node; |
60 | |
16efd15b |
61 | #define LF_ALLOC 1u |
359df778 |
62 | |
63 | /* --- Locked memory buffer state --- */ |
64 | |
65 | typedef struct lmem { |
47d5f7c2 |
66 | arena a; /* Arena header block */ |
37038e63 |
67 | unsigned f; /* Various flags */ |
359df778 |
68 | char *p; /* Pointer to locked buffer */ |
69 | l_node *l; /* Pointer to block list */ |
70 | size_t sz; /* Size of locked buffer */ |
71 | size_t free; /* Size of free area */ |
72 | int err; char *emsg; /* Error indicators */ |
73 | } lmem; |
74 | |
16efd15b |
75 | #define LF_LOCKED 1u |
47d5f7c2 |
76 | |
359df778 |
77 | /*----- Functions provided ------------------------------------------------*/ |
78 | |
79 | /* --- @l_init@ --- * |
80 | * |
81 | * Arguments: @lmem *lm@ = pointer to locked memory descriptor |
82 | * @size_t sz@ = size of locked memory area requested |
83 | * |
84 | * Returns: Zero if everything is fine, @+1@ if some insecure memory was |
85 | * allocated, and @-1@ if everything went horribly wrong. |
86 | * |
87 | * Use: Initializes the locked memory manager. This function is safe |
88 | * to call in a privileged program; privileges should usually be |
89 | * dropped after allocating the locked memory block. |
90 | * |
91 | * You must call @sub_init@ before allocating locked memory |
92 | * buffers. |
93 | */ |
94 | |
95 | extern int l_init(lmem */*lm*/, size_t /*sz*/); |
96 | |
97 | /* --- @l_alloc@ --- * |
98 | * |
99 | * Arguments: @lmem *lm@ = pointer to locked memory descriptor |
100 | * @size_t sz@ = size requested |
101 | * |
102 | * Returns: Pointer to allocated memory. |
103 | * |
104 | * Use: Allocates @sz@ bytes of locked memory. |
105 | */ |
106 | |
107 | extern void *l_alloc(lmem */*lm*/, size_t /*sz*/); |
108 | |
109 | /* --- @l_free@ --- * |
110 | * |
111 | * Arguments: @lmem *lm@ = pointer to locked memory descriptor |
112 | * @void *p@ = pointer to block |
113 | * |
114 | * Returns: --- |
115 | * |
116 | * Use: Releases a block of locked memory. |
117 | */ |
118 | |
119 | extern void l_free(lmem */*lm*/, void */*p*/); |
120 | |
121 | /* --- @l_purge@ --- * |
122 | * |
123 | * Arguments: @lmem *lm@ = pointer to locked memory descriptor |
124 | * |
125 | * Returns: --- |
126 | * |
127 | * Use: Purges all the free blocks in the buffer, and clears all of |
128 | * the locked memory. Memory is not freed back to the system. |
129 | */ |
130 | |
131 | extern void l_purge(lmem */*lm*/); |
132 | |
37038e63 |
133 | /* --- @l_destroy@ --- * |
134 | * |
135 | * Arguments: @lmem *lm@ = pointer to locked memory descriptor |
136 | * |
137 | * Returns: --- |
138 | * |
139 | * Use: Disposes of a locked memory arena permanently. |
140 | */ |
141 | |
142 | extern void l_destroy(lmem */*lm*/); |
143 | |
359df778 |
144 | /* --- @l_report@ --- * |
145 | * |
146 | * Arguments: @lmem *lm@ = pointer to locked memory descriptor |
147 | * @dstr *d@ = string to write the error message on |
148 | * |
149 | * Returns: Zero if the buffer is fine, @+1@ if there was a problem |
150 | * getting locked memory but insecure stuff could be allocated, |
151 | * and @-1@ if not even insecure memory could be found. |
152 | * |
153 | * Use: Returns a user-digestable explanation for the state of a |
154 | * locked memory buffer. If the return code is zero, no message |
155 | * is emitted to the string @d@. |
156 | */ |
157 | |
158 | extern int l_report(lmem */*lm*/, dstr */*d*/); |
159 | |
160 | /*----- That's all, folks -------------------------------------------------*/ |
161 | |
162 | #ifdef __cplusplus |
163 | } |
164 | #endif |
165 | |
166 | #endif |