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 "0.7.3" 10 #endif 11 12 // Populate toy_list[]. 13 14 #undef NEWTOY 15 #undef OLDTOY 16 #define NEWTOY(name, opts, flags) {#name, name##_main, OPTSTR_##name, 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 static void unknown(char *name) 71 { 72 toys.exitval = 127; 73 toys.which = toy_list; 74 error_exit("Unknown command %s", name); 75 } 76 77 // Setup toybox global state for this command. 78 static void toy_singleinit(struct toy_list *which, char *argv[]) 79 { 80 toys.which = which; 81 toys.argv = argv; 82 83 if (CFG_TOYBOX_I18N) setlocale(LC_ALL, "C"+!!(which->flags & TOYFLAG_LOCALE)); 84 85 // Parse --help and --version for (almost) all commands 86 if (CFG_TOYBOX_HELP_DASHDASH && !(which->flags & TOYFLAG_NOHELP) && argv[1]) { 87 if (!strcmp(argv[1], "--help")) { 88 if (CFG_TOYBOX && toys.which == toy_list && toys.argv[2]) 89 if (!(toys.which = toy_find(toys.argv[2]))) unknown(toys.argv[2]); 90 show_help(stdout); 91 xexit(); 92 } 93 94 if (!strcmp(argv[1], "--version")) { 95 xputs("toybox "TOYBOX_VERSION); 96 xexit(); 97 } 98 } 99 100 if (NEED_OPTIONS && which->options) get_optflags(); 101 else { 102 toys.optargs = argv+1; 103 for (toys.optc = 0; toys.optargs[toys.optc]; toys.optc++); 104 } 105 toys.old_umask = umask(0); 106 if (!(which->flags & TOYFLAG_UMASK)) umask(toys.old_umask); 107 toys.signalfd--; 108 toys.toycount = ARRAY_LEN(toy_list); 109 } 110 111 // Full init needed by multiplexer or reentrant calls, calls singleinit at end 112 void toy_init(struct toy_list *which, char *argv[]) 113 { 114 void *oldwhich = toys.which; 115 116 // Drop permissions for non-suid commands. 117 118 if (CFG_TOYBOX_SUID) { 119 if (!toys.which) toys.which = toy_list; 120 121 uid_t uid = getuid(), euid = geteuid(); 122 123 if (!(which->flags & TOYFLAG_STAYROOT)) { 124 if (uid != euid) { 125 if (setuid(uid)) perror_exit("setuid %d->%d", euid, uid); // drop root 126 euid = uid; 127 toys.wasroot++; 128 } 129 } else if (CFG_TOYBOX_DEBUG && uid && which != toy_list) 130 error_msg("Not installed suid root"); 131 132 if ((which->flags & TOYFLAG_NEEDROOT) && euid) help_exit("Not root"); 133 } 134 135 // Free old toys contents (to be reentrant), but leave rebound if any 136 // don't blank old optargs if our new argc lives in the old optargs. 137 if (argv<toys.optargs || argv>toys.optargs+toys.optc) free(toys.optargs); 138 memset(&toys, 0, offsetof(struct toy_context, rebound)); 139 if (oldwhich) memset(&this, 0, sizeof(this)); 140 141 // Continue to portion of init needed by standalone commands 142 toy_singleinit(which, argv); 143 } 144 145 // Like exec() but runs an internal toybox command instead of another file. 146 // Only returns if it can't run command internally, otherwise exit() when done. 147 void toy_exec(char *argv[]) 148 { 149 struct toy_list *which; 150 151 // Return if we can't find it (which includes no multiplexer case), 152 if (!(which = toy_find(*argv))) return; 153 154 // Return if stack depth getting noticeable (proxy for leaked heap, etc). 155 156 // Compiler writers have decided subtracting char * is undefined behavior, 157 // so convert to integers. (LP64 says sizeof(long)==sizeof(pointer).) 158 if (!CFG_TOYBOX_NORECURSE) 159 if (toys.stacktop && labs((long)toys.stacktop-(long)&which)>6000) return; 160 161 // Return if we need to re-exec to acquire root via suid bit. 162 if (toys.which && (which->flags&TOYFLAG_ROOTONLY) && toys.wasroot) return; 163 164 // Run command 165 toy_init(which, argv); 166 if (toys.which) toys.which->toy_main(); 167 xexit(); 168 } 169 170 // Multiplexer command, first argument is command to run, rest are args to that. 171 // If first argument starts with - output list of command install paths. 172 void toybox_main(void) 173 { 174 static char *toy_paths[]={"usr/","bin/","sbin/",0}; 175 int i, len = 0; 176 177 // fast path: try to exec immediately. 178 // (Leave toys.which null to disable suid return logic.) 179 if (toys.argv[1]) toy_exec(toys.argv+1); 180 181 // For early error reporting 182 toys.which = toy_list; 183 184 if (toys.argv[1] && toys.argv[1][0] != '-') unknown(toys.argv[1]); 185 186 // Output list of command. 187 for (i=1; i<ARRAY_LEN(toy_list); i++) { 188 int fl = toy_list[i].flags; 189 if (fl & TOYMASK_LOCATION) { 190 if (toys.argv[1]) { 191 int j; 192 for (j=0; toy_paths[j]; j++) 193 if (fl & (1<<j)) len += printf("%s", toy_paths[j]); 194 } 195 len += printf("%s",toy_list[i].name); 196 if (++len > 65) len = 0; 197 xputc(len ? ' ' : '\n'); 198 } 199 } 200 xputc('\n'); 201 } 202 203 int main(int argc, char *argv[]) 204 { 205 if (!*argv) return 127; 206 207 // Snapshot stack location so we can detect recursion depth later. 208 // This is its own block so probe doesn't permanently consume stack. 209 else { 210 int stack; 211 212 toys.stacktop = &stack; 213 } 214 *argv = getbasename(*argv); 215 216 // Up to and including Android M, bionic's dynamic linker added a handler to 217 // cause a crash dump on SIGPIPE. That was removed in Android N, but adbd 218 // was still setting the SIGPIPE disposition to SIG_IGN, and its children 219 // were inheriting that. In Android O, adbd is fixed, but manually asking 220 // for the default disposition is harmless, and it'll be a long time before 221 // no one's using anything older than O! 222 if (CFG_TOYBOX_ON_ANDROID) signal(SIGPIPE, SIG_DFL); 223 224 // If nommu can't fork, special reentry path. 225 // Use !stacktop to signal "vfork happened", both before and after xexec() 226 if (!CFG_TOYBOX_FORK) { 227 if (0x80 & **argv) { 228 **argv &= 0x7f; 229 toys.stacktop = 0; 230 } 231 } 232 233 if (CFG_TOYBOX) { 234 // Call the multiplexer, adjusting this argv[] to be its' argv[1]. 235 // (It will adjust it back before calling toy_exec().) 236 toys.argv = argv-1; 237 toybox_main(); 238 } else { 239 // a single toybox command built standalone with no multiplexer 240 toy_singleinit(toy_list, argv); 241 toy_list->toy_main(); 242 } 243 244 xexit(); 245 } 246
