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Diffstat (limited to 'src/daemon/https/lgl/xsize.h')
-rw-r--r-- | src/daemon/https/lgl/xsize.h | 108 |
1 files changed, 0 insertions, 108 deletions
diff --git a/src/daemon/https/lgl/xsize.h b/src/daemon/https/lgl/xsize.h deleted file mode 100644 index d8e1b5fe..00000000 --- a/src/daemon/https/lgl/xsize.h +++ /dev/null | |||
@@ -1,108 +0,0 @@ | |||
1 | /* xsize.h -- Checked size_t computations. | ||
2 | |||
3 | Copyright (C) 2003 Free Software Foundation, Inc. | ||
4 | |||
5 | This program is free software; you can redistribute it and/or modify | ||
6 | it under the terms of the GNU Lesser General Public License as published by | ||
7 | the Free Software Foundation; either version 2.1, or (at your option) | ||
8 | any later version. | ||
9 | |||
10 | This program is distributed in the hope that it will be useful, | ||
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
13 | GNU Lesser General Public License for more details. | ||
14 | |||
15 | You should have received a copy of the GNU Lesser General Public License | ||
16 | along with this program; if not, write to the Free Software Foundation, | ||
17 | Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ | ||
18 | |||
19 | #ifndef _XSIZE_H | ||
20 | #define _XSIZE_H | ||
21 | |||
22 | /* Get size_t. */ | ||
23 | #include <stddef.h> | ||
24 | |||
25 | /* Get SIZE_MAX. */ | ||
26 | #include <limits.h> | ||
27 | #if HAVE_STDINT_H | ||
28 | # include <stdint.h> | ||
29 | #endif | ||
30 | |||
31 | /* The size of memory objects is often computed through expressions of | ||
32 | type size_t. Example: | ||
33 | void* p = malloc (header_size + n * element_size). | ||
34 | These computations can lead to overflow. When this happens, malloc() | ||
35 | returns a piece of memory that is way too small, and the program then | ||
36 | crashes while attempting to fill the memory. | ||
37 | To avoid this, the functions and macros in this file check for overflow. | ||
38 | The convention is that SIZE_MAX represents overflow. | ||
39 | malloc (SIZE_MAX) is not guaranteed to fail -- think of a malloc | ||
40 | implementation that uses mmap --, it's recommended to use size_overflow_p() | ||
41 | or size_in_bounds_p() before invoking malloc(). | ||
42 | The example thus becomes: | ||
43 | size_t size = xsum (header_size, xtimes (n, element_size)); | ||
44 | void *p = (size_in_bounds_p (size) ? malloc (size) : NULL); | ||
45 | */ | ||
46 | |||
47 | /* Convert an arbitrary value >= 0 to type size_t. */ | ||
48 | #define xcast_size_t(N) \ | ||
49 | ((N) <= SIZE_MAX ? (size_t) (N) : SIZE_MAX) | ||
50 | |||
51 | /* Sum of two sizes, with overflow check. */ | ||
52 | static inline size_t | ||
53 | #if __GNUC__ >= 3 | ||
54 | __attribute__ ((__pure__)) | ||
55 | #endif | ||
56 | xsum (size_t size1, size_t size2) | ||
57 | { | ||
58 | size_t sum = size1 + size2; | ||
59 | return (sum >= size1 ? sum : SIZE_MAX); | ||
60 | } | ||
61 | |||
62 | /* Sum of three sizes, with overflow check. */ | ||
63 | static inline size_t | ||
64 | #if __GNUC__ >= 3 | ||
65 | __attribute__ ((__pure__)) | ||
66 | #endif | ||
67 | xsum3 (size_t size1, size_t size2, size_t size3) | ||
68 | { | ||
69 | return xsum (xsum (size1, size2), size3); | ||
70 | } | ||
71 | |||
72 | /* Sum of four sizes, with overflow check. */ | ||
73 | static inline size_t | ||
74 | #if __GNUC__ >= 3 | ||
75 | __attribute__ ((__pure__)) | ||
76 | #endif | ||
77 | xsum4 (size_t size1, size_t size2, size_t size3, size_t size4) | ||
78 | { | ||
79 | return xsum (xsum (xsum (size1, size2), size3), size4); | ||
80 | } | ||
81 | |||
82 | /* Maximum of two sizes, with overflow check. */ | ||
83 | static inline size_t | ||
84 | #if __GNUC__ >= 3 | ||
85 | __attribute__ ((__pure__)) | ||
86 | #endif | ||
87 | xmax (size_t size1, size_t size2) | ||
88 | { | ||
89 | /* No explicit check is needed here, because for any n: | ||
90 | max (SIZE_MAX, n) == SIZE_MAX and max (n, SIZE_MAX) == SIZE_MAX. */ | ||
91 | return (size1 >= size2 ? size1 : size2); | ||
92 | } | ||
93 | |||
94 | /* Multiplication of a count with an element size, with overflow check. | ||
95 | The count must be >= 0 and the element size must be > 0. | ||
96 | This is a macro, not an inline function, so that it works correctly even | ||
97 | when N is of a wider tupe and N > SIZE_MAX. */ | ||
98 | #define xtimes(N, ELSIZE) \ | ||
99 | ((N) <= SIZE_MAX / (ELSIZE) ? (size_t) (N) * (ELSIZE) : SIZE_MAX) | ||
100 | |||
101 | /* Check for overflow. */ | ||
102 | #define size_overflow_p(SIZE) \ | ||
103 | ((SIZE) == SIZE_MAX) | ||
104 | /* Check against overflow. */ | ||
105 | #define size_in_bounds_p(SIZE) \ | ||
106 | ((SIZE) != SIZE_MAX) | ||
107 | |||
108 | #endif /* _XSIZE_H */ | ||