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      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 "0.5.2"
     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 // Subset of init needed by singlemain
     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();
     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 // Setup toybox global state for this command.
     97 
     98 void toy_init(struct toy_list *which, char *argv[])
     99 {
    100   // Drop permissions for non-suid commands.
    101 
    102   if (CFG_TOYBOX_SUID) {
    103     uid_t uid = getuid(), euid = geteuid();
    104 
    105     if (!(which->flags & TOYFLAG_STAYROOT)) {
    106       if (uid != euid) {
    107         if (!setuid(uid)) perror_exit("setuid %d->%d", euid, uid); // drop root
    108         else euid = uid;
    109       }
    110     } else if (CFG_TOYBOX_DEBUG && uid && which != toy_list)
    111       error_msg("Not installed suid root");
    112 
    113     if ((which->flags & TOYFLAG_NEEDROOT) && euid) {
    114       toys.exithelp++;
    115       error_exit("Not root");
    116     }
    117   }
    118 
    119   // Free old toys contents (to be reentrant), but leave rebound if any
    120 
    121   if (toys.optargs != toys.argv+1) free(toys.optargs);
    122   memset(&toys, 0, offsetof(struct toy_context, rebound));
    123   if (toys.recursion > 1) memset(&this, 0, sizeof(this));
    124 
    125   // Subset of init needed by singlemain.
    126   toy_singleinit(which, argv);
    127 }
    128 
    129 // Like exec() but runs an internal toybox command instead of another file.
    130 // Only returns if it can't run command internally, otherwise exit() when done.
    131 void toy_exec(char *argv[])
    132 {
    133   struct toy_list *which;
    134 
    135   // Return if we can't find it, or need to re-exec to acquire root,
    136   // or if stack depth is getting silly.
    137   if (!(which = toy_find(argv[0]))) return;
    138   if (toys.recursion && (which->flags & TOYFLAG_ROOTONLY) && getuid()) return;
    139   if (toys.recursion++ > 5) return;
    140 
    141   // don't blank old optargs if our new argc lives in the old optargs.
    142   if (argv>=toys.optargs && argv<=toys.optargs+toys.optc) toys.optargs = 0;
    143 
    144   // Run command
    145   toy_init(which, argv);
    146   if (toys.which) toys.which->toy_main();
    147   xexit();
    148 }
    149 
    150 // Multiplexer command, first argument is command to run, rest are args to that.
    151 // If first argument starts with - output list of command install paths.
    152 
    153 void toybox_main(void)
    154 {
    155   static char *toy_paths[]={"usr/","bin/","sbin/",0};
    156   int i, len = 0;
    157 
    158   toys.which = toy_list;
    159   if (toys.argv[1]) {
    160     toys.optc = toys.recursion = 0;
    161     toy_exec(toys.argv+1);
    162     if (!strcmp("--version", toys.argv[1])) {
    163       xputs(TOYBOX_VERSION);
    164       xexit();
    165     }
    166     if (toys.argv[1][0] != '-') error_exit("Unknown command %s", toys.argv[1]);
    167   }
    168 
    169   // Output list of command.
    170   for (i=1; i<ARRAY_LEN(toy_list); i++) {
    171     int fl = toy_list[i].flags;
    172     if (fl & TOYMASK_LOCATION) {
    173       if (toys.argv[1]) {
    174         int j;
    175         for (j=0; toy_paths[j]; j++)
    176           if (fl & (1<<j)) len += printf("%s", toy_paths[j]);
    177       }
    178       len += printf("%s",toy_list[i].name);
    179       if (++len > 65) len = 0;
    180       xputc(len ? ' ' : '\n');
    181     }
    182   }
    183   xputc('\n');
    184 }
    185 
    186 int main(int argc, char *argv[])
    187 {
    188   // We check our own stdout errors, disable sigpipe killer
    189   signal(SIGPIPE, SIG_IGN);
    190 
    191   if (CFG_TOYBOX) {
    192     // Trim path off of command name
    193     *argv = basename(*argv);
    194 
    195     // Call the multiplexer, adjusting this argv[] to be its' argv[1].
    196     // (It will adjust it back before calling toy_exec().)
    197     toys.argv = argv-1;
    198     toybox_main();
    199   } else {
    200     // a single toybox command built standalone with no multiplexer
    201     toy_singleinit(toy_list, argv);
    202     toy_list->toy_main();
    203   }
    204 
    205   xexit();
    206 }
    207