OpenWrt – Blame information for rev 1
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Rev | Author | Line No. | Line |
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1 | office | 1 | /* |
2 | * xorimage.c - partially based on OpenWrt's addpattern.c |
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3 | * |
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4 | * This program is free software; you can redistribute it and/or modify |
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5 | * it under the terms of the GNU General Public License as published by |
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6 | * the Free Software Foundation; either version 2 of the License, or |
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7 | * (at your option) any later version. |
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8 | * |
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9 | * This program is distributed in the hope that it will be useful, |
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10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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12 | * General Public License for more details. |
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13 | * |
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14 | * You should have received a copy of the GNU General Public License |
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15 | * along with this program; if not, write to the Free Software |
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16 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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17 | */ |
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18 | |||
19 | |||
20 | #include <stdio.h> |
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21 | #include <stdlib.h> |
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22 | #include <string.h> |
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23 | #include <stdbool.h> |
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24 | #include <stdint.h> |
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25 | #include <unistd.h> |
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26 | #include <sys/stat.h> |
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27 | |||
28 | static char default_pattern[] = "12345678"; |
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29 | static int is_hex_pattern; |
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30 | |||
31 | |||
32 | int xor_data(uint8_t *data, size_t len, const uint8_t *pattern, int p_len, int p_off) |
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33 | { |
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34 | int offset = p_off; |
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35 | while (len--) { |
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36 | *data ^= pattern[offset]; |
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37 | data++; |
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38 | offset = (offset + 1) % p_len; |
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39 | } |
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40 | return offset; |
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41 | } |
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42 | |||
43 | |||
44 | void usage(void) __attribute__ (( __noreturn__ )); |
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45 | |||
46 | void usage(void) |
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47 | { |
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48 | fprintf(stderr, "Usage: xorimage [-i infile] [-o outfile] [-p <pattern>] [-x]\n"); |
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49 | exit(EXIT_FAILURE); |
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50 | } |
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51 | |||
52 | |||
53 | int main(int argc, char **argv) |
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54 | { |
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55 | char buf[1024]; /* keep this at 1k or adjust garbage calc below */ |
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56 | FILE *in = stdin; |
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57 | FILE *out = stdout; |
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58 | char *ifn = NULL; |
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59 | char *ofn = NULL; |
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60 | const char *pattern = default_pattern; |
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61 | char hex_pattern[128]; |
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62 | unsigned int hex_buf; |
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63 | int c; |
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64 | int v0, v1, v2; |
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65 | size_t n; |
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66 | int p_len, p_off = 0; |
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67 | |||
68 | while ((c = getopt(argc, argv, "i:o:p:xh")) != -1) { |
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69 | switch (c) { |
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70 | case 'i': |
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71 | ifn = optarg; |
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72 | break; |
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73 | case 'o': |
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74 | ofn = optarg; |
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75 | break; |
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76 | case 'p': |
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77 | pattern = optarg; |
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78 | break; |
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79 | case 'x': |
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80 | is_hex_pattern = true; |
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81 | break; |
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82 | case 'h': |
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83 | default: |
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84 | usage(); |
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85 | } |
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86 | } |
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87 | |||
88 | if (optind != argc || optind == 1) { |
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89 | fprintf(stderr, "illegal arg \"%s\"\n", argv[optind]); |
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90 | usage(); |
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91 | } |
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92 | |||
93 | if (ifn && !(in = fopen(ifn, "r"))) { |
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94 | fprintf(stderr, "can not open \"%s\" for reading\n", ifn); |
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95 | usage(); |
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96 | } |
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97 | |||
98 | if (ofn && !(out = fopen(ofn, "w"))) { |
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99 | fprintf(stderr, "can not open \"%s\" for writing\n", ofn); |
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100 | usage(); |
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101 | } |
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102 | |||
103 | p_len = strlen(pattern); |
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104 | |||
105 | if (p_len == 0) { |
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106 | fprintf(stderr, "pattern cannot be empty\n"); |
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107 | usage(); |
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108 | } |
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109 | |||
110 | if (is_hex_pattern) { |
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111 | int i; |
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112 | |||
113 | if ((p_len / 2) > sizeof(hex_pattern)) { |
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114 | fprintf(stderr, "provided hex pattern is too long\n"); |
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115 | usage(); |
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116 | } |
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117 | |||
118 | if (p_len % 2 != 0) { |
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119 | fprintf(stderr, "the number of characters (hex) is incorrect\n"); |
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120 | usage(); |
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121 | } |
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122 | |||
123 | for (i = 0; i < (p_len / 2); i++) { |
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124 | if (sscanf(pattern + (i * 2), "%2x", &hex_buf) < 0) { |
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125 | fprintf(stderr, "invalid hex digit around %d\n", i * 2); |
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126 | usage(); |
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127 | } |
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128 | hex_pattern[i] = (char)hex_buf; |
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129 | } |
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130 | } |
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131 | |||
132 | while ((n = fread(buf, 1, sizeof(buf), in)) > 0) { |
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133 | if (n < sizeof(buf)) { |
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134 | if (ferror(in)) { |
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135 | FREAD_ERROR: |
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136 | fprintf(stderr, "fread error\n"); |
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137 | return EXIT_FAILURE; |
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138 | } |
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139 | } |
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140 | |||
141 | if (is_hex_pattern) { |
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142 | p_off = xor_data(buf, n, hex_pattern, (p_len / 2), |
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143 | p_off); |
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144 | } else { |
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145 | p_off = xor_data(buf, n, pattern, p_len, p_off); |
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146 | } |
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147 | |||
148 | if (!fwrite(buf, n, 1, out)) { |
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149 | FWRITE_ERROR: |
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150 | fprintf(stderr, "fwrite error\n"); |
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151 | return EXIT_FAILURE; |
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152 | } |
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153 | } |
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154 | |||
155 | if (ferror(in)) { |
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156 | goto FREAD_ERROR; |
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157 | } |
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158 | |||
159 | if (fflush(out)) { |
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160 | goto FWRITE_ERROR; |
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161 | } |
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162 | |||
163 | fclose(in); |
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164 | fclose(out); |
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165 | |||
166 | return EXIT_SUCCESS; |
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167 | } |