1 | /* vi: set sw=4 ts=4: */
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2 | /*
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3 | * test implementation for busybox
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4 | *
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5 | * Copyright (c) by a whole pile of folks:
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6 | *
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7 | * test(1); version 7-like -- author Erik Baalbergen
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8 | * modified by Eric Gisin to be used as built-in.
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9 | * modified by Arnold Robbins to add SVR3 compatibility
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10 | * (-x -c -b -p -u -g -k) plus Korn's -L -nt -ot -ef and new -S (socket).
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11 | * modified by J.T. Conklin for NetBSD.
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12 | * modified by Herbert Xu to be used as built-in in ash.
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13 | * modified by Erik Andersen <andersen@codepoet.org> to be used
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14 | * in busybox.
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15 | * modified by Bernhard Fischer to be useable (i.e. a bit less bloaty).
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16 | *
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17 | * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
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18 | *
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19 | * Original copyright notice states:
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20 | * "This program is in the Public Domain."
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21 | */
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22 |
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23 | #include "libbb.h"
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24 | #include <setjmp.h>
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25 |
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26 | /* This is a NOEXEC applet. Be very careful! */
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27 |
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28 |
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29 | /* test(1) accepts the following grammar:
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30 | oexpr ::= aexpr | aexpr "-o" oexpr ;
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31 | aexpr ::= nexpr | nexpr "-a" aexpr ;
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32 | nexpr ::= primary | "!" primary
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33 | primary ::= unary-operator operand
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34 | | operand binary-operator operand
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35 | | operand
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36 | | "(" oexpr ")"
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37 | ;
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38 | unary-operator ::= "-r"|"-w"|"-x"|"-f"|"-d"|"-c"|"-b"|"-p"|
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39 | "-u"|"-g"|"-k"|"-s"|"-t"|"-z"|"-n"|"-o"|"-O"|"-G"|"-L"|"-S";
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40 |
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41 | binary-operator ::= "="|"=="|"!="|"-eq"|"-ne"|"-ge"|"-gt"|"-le"|"-lt"|
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42 | "-nt"|"-ot"|"-ef";
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43 | operand ::= <any legal UNIX file name>
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44 | */
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45 |
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46 | enum token {
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47 | EOI,
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48 | FILRD,
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49 | FILWR,
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50 | FILEX,
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51 | FILEXIST,
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52 | FILREG,
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53 | FILDIR,
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54 | FILCDEV,
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55 | FILBDEV,
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56 | FILFIFO,
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57 | FILSOCK,
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58 | FILSYM,
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59 | FILGZ,
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60 | FILTT,
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61 | FILSUID,
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62 | FILSGID,
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63 | FILSTCK,
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64 | FILNT,
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65 | FILOT,
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66 | FILEQ,
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67 | FILUID,
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68 | FILGID,
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69 | STREZ,
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70 | STRNZ,
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71 | STREQ,
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72 | STRNE,
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73 | STRLT,
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74 | STRGT,
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75 | INTEQ,
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76 | INTNE,
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77 | INTGE,
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78 | INTGT,
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79 | INTLE,
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80 | INTLT,
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81 | UNOT,
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82 | BAND,
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83 | BOR,
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84 | LPAREN,
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85 | RPAREN,
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86 | OPERAND
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87 | };
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88 | #define is_int_op(a) (((unsigned char)((a) - INTEQ)) <= 5)
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89 | #define is_str_op(a) (((unsigned char)((a) - STREZ)) <= 5)
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90 | #define is_file_op(a) (((unsigned char)((a) - FILNT)) <= 2)
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91 | #define is_file_access(a) (((unsigned char)((a) - FILRD)) <= 2)
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92 | #define is_file_type(a) (((unsigned char)((a) - FILREG)) <= 5)
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93 | #define is_file_bit(a) (((unsigned char)((a) - FILSUID)) <= 2)
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94 | enum token_types {
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95 | UNOP,
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96 | BINOP,
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97 | BUNOP,
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98 | BBINOP,
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99 | PAREN
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100 | };
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101 |
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102 | static const struct t_op {
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103 | char op_text[4];
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104 | unsigned char op_num, op_type;
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105 | } ops[] = {
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106 | { "-r", FILRD , UNOP },
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107 | { "-w", FILWR , UNOP },
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108 | { "-x", FILEX , UNOP },
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109 | { "-e", FILEXIST, UNOP },
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110 | { "-f", FILREG , UNOP },
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111 | { "-d", FILDIR , UNOP },
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112 | { "-c", FILCDEV , UNOP },
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113 | { "-b", FILBDEV , UNOP },
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114 | { "-p", FILFIFO , UNOP },
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115 | { "-u", FILSUID , UNOP },
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116 | { "-g", FILSGID , UNOP },
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117 | { "-k", FILSTCK , UNOP },
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118 | { "-s", FILGZ , UNOP },
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119 | { "-t", FILTT , UNOP },
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120 | { "-z", STREZ , UNOP },
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121 | { "-n", STRNZ , UNOP },
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122 | { "-h", FILSYM , UNOP }, /* for backwards compat */
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123 |
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124 | { "-O" , FILUID , UNOP },
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125 | { "-G" , FILGID , UNOP },
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126 | { "-L" , FILSYM , UNOP },
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127 | { "-S" , FILSOCK, UNOP },
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128 | { "=" , STREQ , BINOP },
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129 | { "==" , STREQ , BINOP },
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130 | { "!=" , STRNE , BINOP },
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131 | { "<" , STRLT , BINOP },
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132 | { ">" , STRGT , BINOP },
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133 | { "-eq", INTEQ , BINOP },
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134 | { "-ne", INTNE , BINOP },
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135 | { "-ge", INTGE , BINOP },
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136 | { "-gt", INTGT , BINOP },
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137 | { "-le", INTLE , BINOP },
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138 | { "-lt", INTLT , BINOP },
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139 | { "-nt", FILNT , BINOP },
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140 | { "-ot", FILOT , BINOP },
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141 | { "-ef", FILEQ , BINOP },
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142 | { "!" , UNOT , BUNOP },
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143 | { "-a" , BAND , BBINOP },
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144 | { "-o" , BOR , BBINOP },
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145 | { "(" , LPAREN , PAREN },
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146 | { ")" , RPAREN , PAREN },
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147 | };
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148 |
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149 |
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150 | #if ENABLE_FEATURE_TEST_64
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151 | typedef int64_t arith_t;
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152 | #else
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153 | typedef int arith_t;
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154 | #endif
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155 |
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156 | /* Cannot eliminate these static data (do the G trick)
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157 | * because of test_main usage from other applets */
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158 | static char **t_wp;
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159 | static struct t_op const *t_wp_op;
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160 | static gid_t *group_array;
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161 | static int ngroups;
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162 | static jmp_buf leaving;
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163 |
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164 | static enum token t_lex(char *s);
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165 | static arith_t oexpr(enum token n);
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166 | static arith_t aexpr(enum token n);
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167 | static arith_t nexpr(enum token n);
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168 | static int binop(void);
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169 | static arith_t primary(enum token n);
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170 | static int filstat(char *nm, enum token mode);
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171 | static arith_t getn(const char *s);
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172 | /* UNUSED
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173 | static int newerf(const char *f1, const char *f2);
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174 | static int olderf(const char *f1, const char *f2);
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175 | static int equalf(const char *f1, const char *f2);
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176 | */
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177 | static int test_eaccess(char *path, int mode);
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178 | static int is_a_group_member(gid_t gid);
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179 | static void initialize_group_array(void);
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180 |
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181 | int test_main(int argc, char **argv)
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182 | {
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183 | int res;
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184 | const char *arg0;
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185 | bool _off;
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186 |
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187 | arg0 = bb_basename(argv[0]);
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188 | if (arg0[0] == '[') {
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189 | --argc;
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190 | if (!arg0[1]) { /* "[" ? */
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191 | if (NOT_LONE_CHAR(argv[argc], ']')) {
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192 | bb_error_msg("missing ]");
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193 | return 2;
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194 | }
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195 | } else { /* assuming "[[" */
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196 | if (strcmp(argv[argc], "]]") != 0) {
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197 | bb_error_msg("missing ]]");
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198 | return 2;
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199 | }
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200 | }
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201 | argv[argc] = NULL;
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202 | }
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203 |
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204 | res = setjmp(leaving);
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205 | if (res)
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206 | return res;
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207 |
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208 | /* resetting ngroups is probably unnecessary. it will
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209 | * force a new call to getgroups(), which prevents using
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210 | * group data fetched during a previous call. but the
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211 | * only way the group data could be stale is if there's
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212 | * been an intervening call to setgroups(), and this
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213 | * isn't likely in the case of a shell. paranoia
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214 | * prevails...
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215 | */
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216 | ngroups = 0;
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217 |
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218 | /* Implement special cases from POSIX.2, section 4.62.4 */
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219 | if (argc == 1)
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220 | return 1;
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221 | if (argc == 2)
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222 | return *argv[1] == '\0';
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223 | //assert(argc);
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224 | /* remember if we saw argc==4 which wants *no* '!' test */
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225 | _off = argc - 4;
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226 | if (_off ?
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227 | (LONE_CHAR(argv[1], '!'))
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228 | : (argv[1][0] != '!' || argv[1][1] != '\0'))
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229 | {
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230 | if (argc == 3)
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231 | return *argv[2] != '\0';
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232 |
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233 | t_lex(argv[2 + _off]);
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234 | if (t_wp_op && t_wp_op->op_type == BINOP) {
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235 | t_wp = &argv[1 + _off];
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236 | return binop() == _off;
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237 | }
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238 | }
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239 | t_wp = &argv[1];
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240 | res = !oexpr(t_lex(*t_wp));
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241 |
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242 | if (*t_wp != NULL && *++t_wp != NULL) {
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243 | bb_error_msg("%s: unknown operand", *t_wp);
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244 | return 2;
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245 | }
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246 | return res;
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247 | }
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248 |
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249 | static void syntax(const char *op, const char *msg) ATTRIBUTE_NORETURN;
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250 | static void syntax(const char *op, const char *msg)
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251 | {
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252 | if (op && *op) {
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253 | bb_error_msg("%s: %s", op, msg);
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254 | } else {
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255 | bb_error_msg("%s: %s"+4, msg);
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256 | }
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257 | longjmp(leaving, 2);
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258 | }
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259 |
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260 | static arith_t oexpr(enum token n)
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261 | {
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262 | arith_t res;
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263 |
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264 | res = aexpr(n);
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265 | if (t_lex(*++t_wp) == BOR) {
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266 | return oexpr(t_lex(*++t_wp)) || res;
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267 | }
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268 | t_wp--;
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269 | return res;
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270 | }
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271 |
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272 | static arith_t aexpr(enum token n)
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273 | {
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274 | arith_t res;
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275 |
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276 | res = nexpr(n);
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277 | if (t_lex(*++t_wp) == BAND)
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278 | return aexpr(t_lex(*++t_wp)) && res;
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279 | t_wp--;
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280 | return res;
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281 | }
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282 |
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283 | static arith_t nexpr(enum token n)
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284 | {
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285 | if (n == UNOT)
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286 | return !nexpr(t_lex(*++t_wp));
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287 | return primary(n);
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288 | }
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289 |
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290 | static arith_t primary(enum token n)
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291 | {
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292 | arith_t res;
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293 |
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294 | if (n == EOI) {
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295 | syntax(NULL, "argument expected");
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296 | }
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297 | if (n == LPAREN) {
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298 | res = oexpr(t_lex(*++t_wp));
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299 | if (t_lex(*++t_wp) != RPAREN)
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300 | syntax(NULL, "closing paren expected");
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301 | return res;
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302 | }
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303 | if (t_wp_op && t_wp_op->op_type == UNOP) {
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304 | /* unary expression */
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305 | if (*++t_wp == NULL)
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306 | syntax(t_wp_op->op_text, "argument expected");
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307 | if (n == STREZ)
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308 | return t_wp[0][0] == '\0';
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309 | if (n == STRNZ)
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310 | return t_wp[0][0] != '\0';
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311 | if (n == FILTT)
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312 | return isatty(getn(*t_wp));
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313 | return filstat(*t_wp, n);
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314 | }
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315 |
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316 | t_lex(t_wp[1]);
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317 | if (t_wp_op && t_wp_op->op_type == BINOP) {
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318 | return binop();
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319 | }
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320 |
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321 | return t_wp[0][0] != '\0';
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322 | }
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323 |
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324 | static int binop(void)
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325 | {
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326 | const char *opnd1, *opnd2;
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327 | struct t_op const *op;
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328 | arith_t val1, val2;
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329 |
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330 | opnd1 = *t_wp;
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331 | (void) t_lex(*++t_wp);
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332 | op = t_wp_op;
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333 |
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334 | opnd2 = *++t_wp;
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335 | if (opnd2 == NULL)
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336 | syntax(op->op_text, "argument expected");
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337 |
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338 | if (is_int_op(op->op_num)) {
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339 | val1 = getn(opnd1);
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340 | val2 = getn(opnd2);
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341 | if (op->op_num == INTEQ)
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342 | return val1 == val2;
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343 | if (op->op_num == INTNE)
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344 | return val1 != val2;
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345 | if (op->op_num == INTGE)
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346 | return val1 >= val2;
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347 | if (op->op_num == INTGT)
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348 | return val1 > val2;
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349 | if (op->op_num == INTLE)
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350 | return val1 <= val2;
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351 | if (op->op_num == INTLT)
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352 | return val1 < val2;
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353 | }
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354 | if (is_str_op(op->op_num)) {
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355 | val1 = strcmp(opnd1, opnd2);
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356 | if (op->op_num == STREQ)
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357 | return val1 == 0;
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358 | if (op->op_num == STRNE)
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359 | return val1 != 0;
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360 | if (op->op_num == STRLT)
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361 | return val1 < 0;
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362 | if (op->op_num == STRGT)
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363 | return val1 > 0;
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364 | }
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365 | /* We are sure that these three are by now the only binops we didn't check
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366 | * yet, so we do not check if the class is correct:
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367 | */
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368 | /* if (is_file_op(op->op_num)) */
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369 | {
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370 | struct stat b1, b2;
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371 |
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372 | if (stat(opnd1, &b1) || stat(opnd2, &b2))
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373 | return 0; /* false, since at least one stat failed */
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374 | if (op->op_num == FILNT)
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375 | return b1.st_mtime > b2.st_mtime;
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376 | if (op->op_num == FILOT)
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377 | return b1.st_mtime < b2.st_mtime;
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378 | if (op->op_num == FILEQ)
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379 | return b1.st_dev == b2.st_dev && b1.st_ino == b2.st_ino;
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380 | }
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381 | return 1; /* NOTREACHED */
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382 | }
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383 |
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384 | static int filstat(char *nm, enum token mode)
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385 | {
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386 | struct stat s;
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387 | int i = i; /* gcc 3.x thinks it can be used uninitialized */
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388 |
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389 | if (mode == FILSYM) {
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390 | #ifdef S_IFLNK
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391 | if (lstat(nm, &s) == 0) {
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392 | i = S_IFLNK;
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393 | goto filetype;
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394 | }
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395 | #endif
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396 | return 0;
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397 | }
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398 |
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399 | if (stat(nm, &s) != 0)
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400 | return 0;
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401 | if (mode == FILEXIST)
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402 | return 1;
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403 | if (is_file_access(mode)) {
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404 | if (mode == FILRD)
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405 | i = R_OK;
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406 | if (mode == FILWR)
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407 | i = W_OK;
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408 | if (mode == FILEX)
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409 | i = X_OK;
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410 | return test_eaccess(nm, i) == 0;
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411 | }
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412 | if (is_file_type(mode)) {
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413 | if (mode == FILREG)
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414 | i = S_IFREG;
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415 | if (mode == FILDIR)
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416 | i = S_IFDIR;
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417 | if (mode == FILCDEV)
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418 | i = S_IFCHR;
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419 | if (mode == FILBDEV)
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420 | i = S_IFBLK;
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421 | if (mode == FILFIFO) {
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422 | #ifdef S_IFIFO
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423 | i = S_IFIFO;
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424 | #else
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425 | return 0;
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426 | #endif
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427 | }
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428 | if (mode == FILSOCK) {
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429 | #ifdef S_IFSOCK
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430 | i = S_IFSOCK;
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431 | #else
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432 | return 0;
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433 | #endif
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434 | }
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435 | filetype:
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436 | return ((s.st_mode & S_IFMT) == i);
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437 | }
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438 | if (is_file_bit(mode)) {
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439 | if (mode == FILSUID)
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440 | i = S_ISUID;
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441 | if (mode == FILSGID)
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442 | i = S_ISGID;
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443 | if (mode == FILSTCK)
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444 | i = S_ISVTX;
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445 | return ((s.st_mode & i) != 0);
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446 | }
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447 | if (mode == FILGZ)
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448 | return s.st_size > 0L;
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449 | if (mode == FILUID)
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450 | return s.st_uid == geteuid();
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451 | if (mode == FILGID)
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452 | return s.st_gid == getegid();
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453 | return 1; /* NOTREACHED */
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454 | }
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455 |
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456 | static enum token t_lex(char *s)
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457 | {
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458 | const struct t_op *op;
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459 |
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460 | t_wp_op = NULL;
|
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461 | if (s == NULL) {
|
---|
462 | return EOI;
|
---|
463 | }
|
---|
464 |
|
---|
465 | op = ops;
|
---|
466 | do {
|
---|
467 | if (strcmp(s, op->op_text) == 0) {
|
---|
468 | t_wp_op = op;
|
---|
469 | return op->op_num;
|
---|
470 | }
|
---|
471 | op++;
|
---|
472 | } while (op < ops + ARRAY_SIZE(ops));
|
---|
473 |
|
---|
474 | return OPERAND;
|
---|
475 | }
|
---|
476 |
|
---|
477 | /* atoi with error detection */
|
---|
478 | //XXX: FIXME: duplicate of existing libbb function?
|
---|
479 | static arith_t getn(const char *s)
|
---|
480 | {
|
---|
481 | char *p;
|
---|
482 | #if ENABLE_FEATURE_TEST_64
|
---|
483 | long long r;
|
---|
484 | #else
|
---|
485 | long r;
|
---|
486 | #endif
|
---|
487 |
|
---|
488 | errno = 0;
|
---|
489 | #if ENABLE_FEATURE_TEST_64
|
---|
490 | r = strtoll(s, &p, 10);
|
---|
491 | #else
|
---|
492 | r = strtol(s, &p, 10);
|
---|
493 | #endif
|
---|
494 |
|
---|
495 | if (errno != 0)
|
---|
496 | syntax(s, "out of range");
|
---|
497 |
|
---|
498 | if (*(skip_whitespace(p)))
|
---|
499 | syntax(s, "bad number");
|
---|
500 |
|
---|
501 | return r;
|
---|
502 | }
|
---|
503 |
|
---|
504 | /* UNUSED
|
---|
505 | static int newerf(const char *f1, const char *f2)
|
---|
506 | {
|
---|
507 | struct stat b1, b2;
|
---|
508 |
|
---|
509 | return (stat(f1, &b1) == 0 &&
|
---|
510 | stat(f2, &b2) == 0 && b1.st_mtime > b2.st_mtime);
|
---|
511 | }
|
---|
512 |
|
---|
513 | static int olderf(const char *f1, const char *f2)
|
---|
514 | {
|
---|
515 | struct stat b1, b2;
|
---|
516 |
|
---|
517 | return (stat(f1, &b1) == 0 &&
|
---|
518 | stat(f2, &b2) == 0 && b1.st_mtime < b2.st_mtime);
|
---|
519 | }
|
---|
520 |
|
---|
521 | static int equalf(const char *f1, const char *f2)
|
---|
522 | {
|
---|
523 | struct stat b1, b2;
|
---|
524 |
|
---|
525 | return (stat(f1, &b1) == 0 &&
|
---|
526 | stat(f2, &b2) == 0 &&
|
---|
527 | b1.st_dev == b2.st_dev && b1.st_ino == b2.st_ino);
|
---|
528 | }
|
---|
529 | */
|
---|
530 |
|
---|
531 | /* Do the same thing access(2) does, but use the effective uid and gid,
|
---|
532 | and don't make the mistake of telling root that any file is
|
---|
533 | executable. */
|
---|
534 | static int test_eaccess(char *path, int mode)
|
---|
535 | {
|
---|
536 | struct stat st;
|
---|
537 | unsigned int euid = geteuid();
|
---|
538 |
|
---|
539 | if (stat(path, &st) < 0)
|
---|
540 | return -1;
|
---|
541 |
|
---|
542 | if (euid == 0) {
|
---|
543 | /* Root can read or write any file. */
|
---|
544 | if (mode != X_OK)
|
---|
545 | return 0;
|
---|
546 |
|
---|
547 | /* Root can execute any file that has any one of the execute
|
---|
548 | bits set. */
|
---|
549 | if (st.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))
|
---|
550 | return 0;
|
---|
551 | }
|
---|
552 |
|
---|
553 | if (st.st_uid == euid) /* owner */
|
---|
554 | mode <<= 6;
|
---|
555 | else if (is_a_group_member(st.st_gid))
|
---|
556 | mode <<= 3;
|
---|
557 |
|
---|
558 | if (st.st_mode & mode)
|
---|
559 | return 0;
|
---|
560 |
|
---|
561 | return -1;
|
---|
562 | }
|
---|
563 |
|
---|
564 | static void initialize_group_array(void)
|
---|
565 | {
|
---|
566 | ngroups = getgroups(0, NULL);
|
---|
567 | if (ngroups > 0) {
|
---|
568 | /* FIXME: ash tries so hard to not die on OOM,
|
---|
569 | * and we spoil it with just one xrealloc here */
|
---|
570 | /* We realloc, because test_main can be entered repeatedly by shell.
|
---|
571 | * Testcase (ash): 'while true; do test -x some_file; done'
|
---|
572 | * and watch top. (some_file must have owner != you) */
|
---|
573 | group_array = xrealloc(group_array, ngroups * sizeof(gid_t));
|
---|
574 | getgroups(ngroups, group_array);
|
---|
575 | }
|
---|
576 | }
|
---|
577 |
|
---|
578 | /* Return non-zero if GID is one that we have in our groups list. */
|
---|
579 | //XXX: FIXME: duplicate of existing libbb function?
|
---|
580 | // see toplevel TODO file:
|
---|
581 | // possible code duplication ingroup() and is_a_group_member()
|
---|
582 | static int is_a_group_member(gid_t gid)
|
---|
583 | {
|
---|
584 | int i;
|
---|
585 |
|
---|
586 | /* Short-circuit if possible, maybe saving a call to getgroups(). */
|
---|
587 | if (gid == getgid() || gid == getegid())
|
---|
588 | return 1;
|
---|
589 |
|
---|
590 | if (ngroups == 0)
|
---|
591 | initialize_group_array();
|
---|
592 |
|
---|
593 | /* Search through the list looking for GID. */
|
---|
594 | for (i = 0; i < ngroups; i++)
|
---|
595 | if (gid == group_array[i])
|
---|
596 | return 1;
|
---|
597 |
|
---|
598 | return 0;
|
---|
599 | }
|
---|