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Commit | Line | Data |
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77157728 TC |
1 | /* |
2 | =head1 NAME | |
3 | ||
4 | limits.c - manages data/functions for limiting the sizes of images read from files. | |
5 | ||
6 | =head1 SYNOPSIS | |
7 | ||
8 | // user code | |
9 | if (!i_set_image_file_limits(max_width, max_height, max_bytes)) { | |
10 | // error | |
11 | } | |
12 | i_get_image_file_limits(&max_width, &max_height, &max_bytes); | |
13 | ||
14 | // file reader implementations | |
15 | if (!i_int_check_image_file_limits(width, height, channels, sizeof(i_sample_t))) { | |
16 | // error handling | |
17 | } | |
18 | ||
19 | =head1 DESCRIPTION | |
20 | ||
21 | Manage limits for image files read by Imager. | |
22 | ||
23 | Setting a value of zero means that limit will be ignored. | |
24 | ||
25 | */ | |
26 | ||
92bda632 | 27 | #include "imageri.h" |
77157728 TC |
28 | |
29 | static int max_width, max_height; | |
30 | static int max_bytes; | |
31 | ||
87deb14c TC |
32 | /* |
33 | =item i_set_image_file_limits(width, height, bytes) | |
34 | ||
35 | =category Files | |
36 | =synopsis i_set_image_file_limits(500, 500, 1000000); | |
37 | ||
38 | Set limits on the sizes of images read by Imager. | |
39 | ||
40 | Setting a limit to 0 means that limit is ignored. | |
41 | ||
42 | Negative limits result in failure. | |
43 | ||
44 | Returns non-zero on success. | |
45 | ||
46 | =cut | |
47 | */ | |
48 | ||
77157728 TC |
49 | int |
50 | i_set_image_file_limits(int width, int height, int bytes) { | |
51 | i_clear_error(); | |
52 | ||
53 | if (width < 0) { | |
54 | i_push_error(0, "width must be non-negative"); | |
55 | return 0; | |
56 | } | |
57 | if (height < 0) { | |
58 | i_push_error(0, "height must be non-negative"); | |
59 | return 0; | |
60 | } | |
61 | if (bytes < 0) { | |
62 | i_push_error(0, "bytes must be non-negative"); | |
63 | return 0; | |
64 | } | |
65 | ||
66 | max_width = width; | |
67 | max_height = height; | |
68 | max_bytes = bytes; | |
69 | ||
70 | return 1; | |
71 | } | |
72 | ||
87deb14c TC |
73 | /* |
74 | =item i_get_image_file_limits(&width, &height, &bytes) | |
75 | ||
76 | =category Files | |
77 | =synopsis i_get_image_file_limits(&width, &height, &bytes) | |
78 | ||
79 | Retrieves the file limits set by i_set_image_file_limits(). | |
80 | ||
81 | =cut | |
82 | */ | |
83 | ||
77157728 TC |
84 | int |
85 | i_get_image_file_limits(int *width, int *height, int *bytes) { | |
86 | i_clear_error(); | |
87 | ||
88 | *width = max_width; | |
89 | *height = max_height; | |
90 | *bytes = max_bytes; | |
91 | ||
92 | return 1; | |
93 | } | |
94 | ||
87deb14c TC |
95 | /* |
96 | =item i_int_check_image_file_limits(width, height, channels, sample_size) | |
97 | ||
98 | =category Files | |
99 | =synopsis i_i_int_check_image_file_limits(width, height, channels, sizeof(i_sample_t)) | |
100 | ||
101 | Checks the size of a file in memory against the configured image file | |
102 | limits. | |
103 | ||
104 | This also range checks the values to those permitted by Imager and | |
105 | checks for overflows in calculating the size. | |
106 | ||
107 | Returns non-zero if the file is within limits. | |
108 | ||
109 | This function is intended to be called by image file read functions. | |
110 | ||
111 | =cut | |
112 | */ | |
113 | ||
77157728 TC |
114 | int |
115 | i_int_check_image_file_limits(int width, int height, int channels, int sample_size) { | |
5caa40a6 | 116 | int bytes; |
77157728 TC |
117 | i_clear_error(); |
118 | ||
119 | if (width <= 0) { | |
120 | i_push_errorf(0, "file size limit - image width of %d is not positive", | |
121 | width); | |
122 | return 0; | |
123 | } | |
124 | if (max_width && width > max_width) { | |
125 | i_push_errorf(0, "file size limit - image width of %d exceeds limit of %d", | |
126 | width, max_width); | |
127 | return 0; | |
128 | } | |
129 | ||
130 | if (height <= 0) { | |
131 | i_push_errorf(0, "file size limit - image height %d is not positive", | |
132 | height); | |
133 | return 0; | |
134 | } | |
135 | ||
136 | if (max_height && height > max_height) { | |
137 | i_push_errorf(0, "file size limit - image height of %d " | |
138 | "exceeds limit of %d", height, max_height); | |
139 | return 0; | |
140 | } | |
141 | ||
142 | if (channels < 1 || channels > MAXCHANNELS) { | |
143 | i_push_errorf(0, "file size limit - channels %d out of range", | |
144 | channels); | |
145 | return 0; | |
146 | } | |
147 | ||
148 | if (sample_size < 1 || sample_size > sizeof(long double)) { | |
149 | i_push_errorf(0, "file size limit - sample_size %d out of range", | |
150 | sample_size); | |
151 | return 0; | |
152 | } | |
153 | ||
154 | /* This overflow check is a bit more paranoid than usual. | |
155 | We don't protect it under max_bytes since we always want to check | |
156 | for overflow. | |
157 | */ | |
5caa40a6 | 158 | bytes = width * height * channels * sample_size; |
77157728 TC |
159 | if (bytes / width != height * channels * sample_size |
160 | || bytes / height != width * channels * sample_size) { | |
161 | i_push_error(0, "file size limit - integer overflow calculating storage"); | |
162 | return 0; | |
163 | } | |
164 | if (max_bytes) { | |
165 | if (bytes > max_bytes) { | |
166 | i_push_errorf(0, "file size limit - storage size of %d " | |
167 | "exceeds limit of %d", bytes, max_bytes); | |
168 | return 0; | |
169 | } | |
170 | } | |
171 | ||
172 | return 1; | |
173 | } |