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 #ifndef TOYBOX_VENDOR 10 #define TOYBOX_VENDOR "" 11 #endif 12 #define TOYBOX_VERSION "0.8.0"TOYBOX_VENDOR 13 #endif 14 15 // Populate toy_list[]. 16 17 #undef NEWTOY 18 #undef OLDTOY 19 #define NEWTOY(name, opts, flags) {#name, name##_main, OPTSTR_##name, flags}, 20 #define OLDTOY(name, oldname, flags) \ 21 {#name, oldname##_main, OPTSTR_##oldname, flags}, 22 23 struct toy_list toy_list[] = { 24 #include "generated/newtoys.h" 25 }; 26 27 // global context for this command. 28 29 struct toy_context toys; 30 union global_union this; 31 char toybuf[4096], libbuf[4096]; 32 33 struct toy_list *toy_find(char *name) 34 { 35 int top, bottom, middle; 36 37 if (!CFG_TOYBOX || strchr(name, '/')) return 0; 38 39 // If the name starts with "toybox" accept that as a match. Otherwise 40 // skip the first entry, which is out of order. 41 42 if (!strncmp(name,"toybox",6)) return toy_list; 43 bottom = 1; 44 45 // Binary search to find this command. 46 47 top = ARRAY_LEN(toy_list)-1; 48 for (;;) { 49 int result; 50 51 middle = (top+bottom)/2; 52 if (middle<bottom || middle>top) return NULL; 53 result = strcmp(name,toy_list[middle].name); 54 if (!result) return toy_list+middle; 55 if (result<0) top = --middle; 56 else bottom = ++middle; 57 } 58 } 59 60 // Figure out whether or not anything is using the option parsing logic, 61 // because the compiler can't figure out whether or not to optimize it away 62 // on its' own. NEED_OPTIONS becomes a constant allowing if() to optimize 63 // stuff out via dead code elimination. 64 65 #undef NEWTOY 66 #undef OLDTOY 67 #define NEWTOY(name, opts, flags) opts || 68 #define OLDTOY(name, oldname, flags) OPTSTR_##oldname || 69 static const int NEED_OPTIONS = 70 #include "generated/newtoys.h" 71 0; // Ends the opts || opts || opts... 72 73 static void unknown(char *name) 74 { 75 toys.exitval = 127; 76 toys.which = toy_list; 77 error_exit("Unknown command %s", name); 78 } 79 80 // Setup toybox global state for this command. 81 static void toy_singleinit(struct toy_list *which, char *argv[]) 82 { 83 toys.which = which; 84 toys.argv = argv; 85 86 if (CFG_TOYBOX_I18N) setlocale(LC_CTYPE, "C.UTF-8"); 87 88 // Parse --help and --version for (almost) all commands 89 if (CFG_TOYBOX_HELP_DASHDASH && !(which->flags & TOYFLAG_NOHELP) && argv[1]) { 90 if (!strcmp(argv[1], "--help")) { 91 if (CFG_TOYBOX && toys.which == toy_list && toys.argv[2]) 92 if (!(toys.which = toy_find(toys.argv[2]))) unknown(toys.argv[2]); 93 show_help(stdout); 94 xexit(); 95 } 96 97 if (!strcmp(argv[1], "--version")) { 98 xputs("toybox "TOYBOX_VERSION); 99 xexit(); 100 } 101 } 102 103 if (NEED_OPTIONS && which->options) get_optflags(); 104 else { 105 toys.optargs = argv+1; 106 for (toys.optc = 0; toys.optargs[toys.optc]; toys.optc++); 107 } 108 toys.old_umask = umask(0); 109 if (!(which->flags & TOYFLAG_UMASK)) umask(toys.old_umask); 110 toys.signalfd--; 111 toys.toycount = ARRAY_LEN(toy_list); 112 } 113 114 // Full init needed by multiplexer or reentrant calls, calls singleinit at end 115 void toy_init(struct toy_list *which, char *argv[]) 116 { 117 void *oldwhich = toys.which; 118 119 // Drop permissions for non-suid commands. 120 121 if (CFG_TOYBOX_SUID) { 122 if (!toys.which) toys.which = toy_list; 123 124 uid_t uid = getuid(), euid = geteuid(); 125 126 if (!(which->flags & TOYFLAG_STAYROOT)) { 127 if (uid != euid) { 128 if (setuid(uid)) perror_exit("setuid %d->%d", euid, uid); // drop root 129 euid = uid; 130 toys.wasroot++; 131 } 132 } else if (CFG_TOYBOX_DEBUG && uid && which != toy_list) 133 error_msg("Not installed suid root"); 134 135 if ((which->flags & TOYFLAG_NEEDROOT) && euid) help_exit("Not root"); 136 } 137 138 // Free old toys contents (to be reentrant), but leave rebound if any 139 // don't blank old optargs if our new argc lives in the old optargs. 140 if (argv<toys.optargs || argv>toys.optargs+toys.optc) free(toys.optargs); 141 memset(&toys, 0, offsetof(struct toy_context, rebound)); 142 if (oldwhich) memset(&this, 0, sizeof(this)); 143 144 // Continue to portion of init needed by standalone commands 145 toy_singleinit(which, argv); 146 } 147 148 // Run an internal toybox command. 149 // Only returns if it can't run command internally, otherwise xexit() when done. 150 void toy_exec_which(struct toy_list *which, char *argv[]) 151 { 152 // Return if we can't find it (which includes no multiplexer case), 153 if (!which) return; 154 155 // Return if stack depth getting noticeable (proxy for leaked heap, etc). 156 157 // Compiler writers have decided subtracting char * is undefined behavior, 158 // so convert to integers. (LP64 says sizeof(long)==sizeof(pointer).) 159 // Signed typecast so stack growth direction is irrelevant: we're measuring 160 // the distance between two pointers on the same stack, hence the labs(). 161 if (!CFG_TOYBOX_NORECURSE && toys.stacktop) 162 if (labs((long)toys.stacktop-(long)&which)>6000) return; 163 164 // Return if we need to re-exec to acquire root via suid bit. 165 if (toys.which && (which->flags&TOYFLAG_ROOTONLY) && toys.wasroot) return; 166 167 // Run command 168 toy_init(which, argv); 169 if (toys.which) toys.which->toy_main(); 170 xexit(); 171 } 172 173 // Lookup internal toybox command to run via argv[0] 174 void toy_exec(char *argv[]) 175 { 176 toy_exec_which(toy_find(basename(*argv)), argv); 177 } 178 179 // Multiplexer command, first argument is command to run, rest are args to that. 180 // If first argument starts with - output list of command install paths. 181 void toybox_main(void) 182 { 183 static char *toy_paths[]={"usr/","bin/","sbin/",0}; 184 int i, len = 0; 185 186 // fast path: try to exec immediately. 187 // (Leave toys.which null to disable suid return logic.) 188 // Try dereferencing one layer of symlink 189 if (toys.argv[1]) { 190 toy_exec(toys.argv+1); 191 if (0<readlink(toys.argv[1], libbuf, sizeof(libbuf))) 192 toy_exec_which(toy_find(basename(libbuf)), toys.argv); 193 } 194 195 // For early error reporting 196 toys.which = toy_list; 197 198 if (toys.argv[1] && toys.argv[1][0] != '-') unknown(toys.argv[1]); 199 200 // Output list of command. 201 for (i=1; i<ARRAY_LEN(toy_list); i++) { 202 int fl = toy_list[i].flags; 203 if (fl & TOYMASK_LOCATION) { 204 if (toys.argv[1]) { 205 int j; 206 for (j=0; toy_paths[j]; j++) 207 if (fl & (1<<j)) len += printf("%s", toy_paths[j]); 208 } 209 len += printf("%s",toy_list[i].name); 210 if (++len > 65) len = 0; 211 xputc(len ? ' ' : '\n'); 212 } 213 } 214 xputc('\n'); 215 } 216 217 int main(int argc, char *argv[]) 218 { 219 if (!*argv) return 127; 220 221 // Snapshot stack location so we can detect recursion depth later. 222 // This is its own block so probe doesn't permanently consume stack. 223 else { 224 int stack; 225 226 toys.stacktop = &stack; 227 } 228 229 // Up to and including Android M, bionic's dynamic linker added a handler to 230 // cause a crash dump on SIGPIPE. That was removed in Android N, but adbd 231 // was still setting the SIGPIPE disposition to SIG_IGN, and its children 232 // were inheriting that. In Android O, adbd is fixed, but manually asking 233 // for the default disposition is harmless, and it'll be a long time before 234 // no one's using anything older than O! 235 if (CFG_TOYBOX_ON_ANDROID) signal(SIGPIPE, SIG_DFL); 236 237 // If nommu can't fork, special reentry path. 238 // Use !stacktop to signal "vfork happened", both before and after xexec() 239 if (!CFG_TOYBOX_FORK) { 240 if (0x80 & **argv) { 241 **argv &= 0x7f; 242 toys.stacktop = 0; 243 } 244 } 245 246 if (CFG_TOYBOX) { 247 // Call the multiplexer, adjusting this argv[] to be its' argv[1]. 248 // (It will adjust it back before calling toy_exec().) 249 toys.argv = argv-1; 250 toybox_main(); 251 } else { 252 // a single toybox command built standalone with no multiplexer 253 toy_singleinit(toy_list, argv); 254 toy_list->toy_main(); 255 } 256 257 xexit(); 258 } 259
