1 /* Toybox infrastructure. 2 * 3 * Copyright 2006 Rob Landley <rob (at) landley.net> 4 */ 5 6 #include "toys.h" 7 8 #ifndef TOYBOX_VERSION 9 #define TOYBOX_VERSION "0.7.0" 10 #endif 11 12 // Populate toy_list[]. 13 14 #undef NEWTOY 15 #undef OLDTOY 16 #define NEWTOY(name, opts, flags) {#name, name##_main, opts, flags}, 17 #define OLDTOY(name, oldname, flags) \ 18 {#name, oldname##_main, OPTSTR_##oldname, flags}, 19 20 struct toy_list toy_list[] = { 21 #include "generated/newtoys.h" 22 }; 23 24 // global context for this command. 25 26 struct toy_context toys; 27 union global_union this; 28 char toybuf[4096], libbuf[4096]; 29 30 struct toy_list *toy_find(char *name) 31 { 32 int top, bottom, middle; 33 34 if (!CFG_TOYBOX) return 0; 35 36 // If the name starts with "toybox" accept that as a match. Otherwise 37 // skip the first entry, which is out of order. 38 39 if (!strncmp(name,"toybox",6)) return toy_list; 40 bottom = 1; 41 42 // Binary search to find this command. 43 44 top = ARRAY_LEN(toy_list)-1; 45 for (;;) { 46 int result; 47 48 middle = (top+bottom)/2; 49 if (middle<bottom || middle>top) return NULL; 50 result = strcmp(name,toy_list[middle].name); 51 if (!result) return toy_list+middle; 52 if (result<0) top=--middle; 53 else bottom = ++middle; 54 } 55 } 56 57 // Figure out whether or not anything is using the option parsing logic, 58 // because the compiler can't figure out whether or not to optimize it away 59 // on its' own. NEED_OPTIONS becomes a constant allowing if() to optimize 60 // stuff out via dead code elimination. 61 62 #undef NEWTOY 63 #undef OLDTOY 64 #define NEWTOY(name, opts, flags) opts || 65 #define OLDTOY(name, oldname, flags) OPTSTR_##oldname || 66 static const int NEED_OPTIONS = 67 #include "generated/newtoys.h" 68 0; // Ends the opts || opts || opts... 69 70 // Setup toybox global state for this command. 71 static void toy_singleinit(struct toy_list *which, char *argv[]) 72 { 73 toys.which = which; 74 toys.argv = argv; 75 76 if (CFG_TOYBOX_I18N) setlocale(LC_ALL, "C"+!!(which->flags & TOYFLAG_LOCALE)); 77 78 if (CFG_TOYBOX_HELP_DASHDASH && argv[1] && !strcmp(argv[1], "--help")) { 79 if (CFG_TOYBOX && toys.which == toy_list && toys.argv[2]) 80 if (!(toys.which = toy_find(toys.argv[2]))) return; 81 show_help(stdout); 82 xexit(); 83 } 84 85 if (NEED_OPTIONS && which->options) get_optflags(); 86 else { 87 toys.optargs = argv+1; 88 for (toys.optc = 0; toys.optargs[toys.optc]; toys.optc++); 89 } 90 toys.old_umask = umask(0); 91 if (!(which->flags & TOYFLAG_UMASK)) umask(toys.old_umask); 92 toys.signalfd--; 93 toys.toycount = ARRAY_LEN(toy_list); 94 } 95 96 // Full init needed by multiplexer or reentrant calls, calls singleinit at end 97 void toy_init(struct toy_list *which, char *argv[]) 98 { 99 void *oldwhich = toys.which; 100 101 // Drop permissions for non-suid commands. 102 103 if (CFG_TOYBOX_SUID) { 104 if (!toys.which) toys.which = toy_list; 105 106 uid_t uid = getuid(), euid = geteuid(); 107 108 if (!(which->flags & TOYFLAG_STAYROOT)) { 109 if (uid != euid) { 110 if (setuid(uid)) perror_exit("setuid %d->%d", euid, uid); // drop root 111 euid = uid; 112 toys.wasroot++; 113 } 114 } else if (CFG_TOYBOX_DEBUG && uid && which != toy_list) 115 error_msg("Not installed suid root"); 116 117 if ((which->flags & TOYFLAG_NEEDROOT) && euid) help_exit("Not root"); 118 } 119 120 // Free old toys contents (to be reentrant), but leave rebound if any 121 // don't blank old optargs if our new argc lives in the old optargs. 122 if (argv<toys.optargs || argv>toys.optargs+toys.optc) free(toys.optargs); 123 memset(&toys, 0, offsetof(struct toy_context, rebound)); 124 if (oldwhich) memset(&this, 0, sizeof(this)); 125 126 // Continue to portion of init needed by standalone commands 127 toy_singleinit(which, argv); 128 } 129 130 // Like exec() but runs an internal toybox command instead of another file. 131 // Only returns if it can't run command internally, otherwise exit() when done. 132 void toy_exec(char *argv[]) 133 { 134 struct toy_list *which; 135 136 // Return if we can't find it (which includes no multiplexer case), 137 if (!(which = toy_find(*argv))) return; 138 139 // Return if stack depth getting noticeable (proxy for leaked heap, etc). 140 if (toys.stacktop && labs((char *)toys.stacktop-(char *)&which)>6000) 141 return; 142 143 // Return if we need to re-exec to acquire root via suid bit. 144 if (toys.which && (which->flags&TOYFLAG_ROOTONLY) && toys.wasroot) return; 145 146 // Run command 147 toy_init(which, argv); 148 if (toys.which) toys.which->toy_main(); 149 xexit(); 150 } 151 152 // Multiplexer command, first argument is command to run, rest are args to that. 153 // If first argument starts with - output list of command install paths. 154 void toybox_main(void) 155 { 156 static char *toy_paths[]={"usr/","bin/","sbin/",0}; 157 int i, len = 0; 158 159 // fast path: try to exec immediately. 160 // (Leave toys.which null to disable suid return logic.) 161 if (toys.argv[1]) toy_exec(toys.argv+1); 162 163 // For early error reporting 164 toys.which = toy_list; 165 166 if (toys.argv[1]) { 167 if (!strcmp("--version", toys.argv[1])) { 168 xputs(TOYBOX_VERSION); 169 xexit(); 170 } 171 if (toys.argv[1][0] != '-') { 172 toys.exitval = 127; 173 error_exit("Unknown command %s", toys.argv[1]); 174 } 175 } 176 177 // Output list of command. 178 for (i=1; i<ARRAY_LEN(toy_list); i++) { 179 int fl = toy_list[i].flags; 180 if (fl & TOYMASK_LOCATION) { 181 if (toys.argv[1]) { 182 int j; 183 for (j=0; toy_paths[j]; j++) 184 if (fl & (1<<j)) len += printf("%s", toy_paths[j]); 185 } 186 len += printf("%s",toy_list[i].name); 187 if (++len > 65) len = 0; 188 xputc(len ? ' ' : '\n'); 189 } 190 } 191 xputc('\n'); 192 } 193 194 int main(int argc, char *argv[]) 195 { 196 if (!*argv) return 127; 197 198 // Snapshot stack location so we can detect recursion depth later. 199 // This is its own block so probe doesn't permanently consume stack. 200 else { 201 int stack; 202 203 toys.stacktop = &stack; 204 } 205 *argv = basename_r(*argv); 206 207 // If nommu can't fork, special reentry path. 208 // Use !stacktop to signal "vfork happened", both before and after xexec() 209 if (!CFG_TOYBOX_FORK) { 210 if (0x80 & **argv) { 211 **argv &= 0x7f; 212 toys.stacktop = 0; 213 } 214 } 215 216 if (CFG_TOYBOX) { 217 // Call the multiplexer, adjusting this argv[] to be its' argv[1]. 218 // (It will adjust it back before calling toy_exec().) 219 toys.argv = argv-1; 220 toybox_main(); 221 } else { 222 // a single toybox command built standalone with no multiplexer 223 toy_singleinit(toy_list, argv); 224 toy_list->toy_main(); 225 } 226 227 xexit(); 228 } 229
