main.c

/* Toybox infrastructure.
 *
 * Copyright 2006 Rob Landley <rob@landley.net>
 */

#include "toys.h"

// Populate toy_list[].

#undef NEWTOY
#undef OLDTOY
#define NEWTOY(name, opts, flags) {#name, name##_main, opts, flags},
#define OLDTOY(name, oldname, opts, flags) {#name, oldname##_main, opts, flags},

struct toy_list toy_list[] = {
#include "generated/newtoys.h"
};

// global context for this command.

struct toy_context toys;
union global_union this;
char toybuf[4096], libbuf[4096];

struct toy_list *toy_find(char *name)
{
  int top, bottom, middle;

  if (!CFG_TOYBOX) return 0;

  // If the name starts with "toybox" accept that as a match.  Otherwise
  // skip the first entry, which is out of order.

  if (!strncmp(name,"toybox",6)) return toy_list;
  bottom = 1;

  // Binary search to find this command.

  top = ARRAY_LEN(toy_list)-1;
  for (;;) {
    int result;

    middle = (top+bottom)/2;
    if (middle<bottom || middle>top) return NULL;
    result = strcmp(name,toy_list[middle].name);
    if (!result) return toy_list+middle;
    if (result<0) top=--middle;
    else bottom = ++middle;
  }
}

// Figure out whether or not anything is using the option parsing logic,
// because the compiler can't figure out whether or not to optimize it away
// on its' own.  NEED_OPTIONS becomes a constant allowing if() to optimize
// stuff out via dead code elimination.

#undef NEWTOY
#undef OLDTOY
#define NEWTOY(name, opts, flags) opts ||
#define OLDTOY(name, oldname, opts, flags) opts ||
static const int NEED_OPTIONS =
#include "generated/newtoys.h"
0;  // Ends the opts || opts || opts...

// Subset of init needed by singlemain
static void toy_singleinit(struct toy_list *which, char *argv[])
{
  toys.which = which;
  toys.argv = argv;

  if (CFG_TOYBOX_I18N) setlocale(LC_ALL, "C"+!!(which->flags & TOYFLAG_LOCALE));

  if (CFG_TOYBOX_HELP_DASHDASH && argv[1] && !strcmp(argv[1], "--help")) {
    if (CFG_TOYBOX && toys.which == toy_list && toys.argv[2])
      if (!(toys.which = toy_find(toys.argv[2]))) return;
    show_help();
    xexit();
  }

  if (NEED_OPTIONS && which->options) get_optflags();
  else {
    toys.optargs = argv+1;
    for (toys.optc=0; toys.optargs[toys.optc]; toys.optc++);
  }
  toys.old_umask = umask(0);
  if (!(which->flags & TOYFLAG_UMASK)) umask(toys.old_umask);
  toys.signalfd--;
  toys.toycount = ARRAY_LEN(toy_list);
}

// Setup toybox global state for this command.

void toy_init(struct toy_list *which, char *argv[])
{
  // Drop permissions for non-suid commands.

  if (CFG_TOYBOX_SUID) {
    uid_t uid = getuid(), euid = geteuid();

    if (!(which->flags & TOYFLAG_STAYROOT)) {
      if (uid != euid) {
        if (!setuid(uid)) perror_exit("setuid %d->%d", euid, uid); // drop root
        else euid = uid;
      }
    } else if (CFG_TOYBOX_DEBUG && uid && which != toy_list)
      error_msg("Not installed suid root");

    if ((which->flags & TOYFLAG_NEEDROOT) && euid) {
      toys.exithelp++;
      error_exit("Not root");
    }
  }

  // Free old toys contents (to be reentrant), but leave rebound if any

  if (toys.optargs != toys.argv+1) free(toys.optargs);
  memset(&toys, 0, offsetof(struct toy_context, rebound));

  // Subset of init needed by singlemain.
  toy_singleinit(which, argv);
}

// Like exec() but runs an internal toybox command instead of another file.
// Only returns if it can't run command internally, otherwise exit() when done.
void toy_exec(char *argv[])
{
  struct toy_list *which;

  // Return if we can't find it, or need to re-exec to acquire root,
  // or if stack depth is getting silly.
  if (!(which = toy_find(argv[0]))) return;
  if (toys.recursion && (which->flags & TOYFLAG_ROOTONLY) && getuid()) return;
  if (toys.recursion++ > 5) return;

  // Run command
  toy_init(which, argv);
  if (toys.which) toys.which->toy_main();
  if (fflush(NULL) || ferror(stdout)) perror_exit("write");
  xexit();
}

// Multiplexer command, first argument is command to run, rest are args to that.
// If first argument starts with - output list of command install paths.

void toybox_main(void)
{
  static char *toy_paths[]={"usr/","bin/","sbin/",0};
  int i, len = 0;

  toys.which = toy_list;
  if (toys.argv[1]) {
    toys.optc = 0;
    toy_exec(toys.argv+1);
    if (toys.argv[1][0] == '-') goto list;
    
    error_exit("Unknown command %s",toys.argv[1]);
  }

list:
  // Output list of command.
  for (i=1; i<ARRAY_LEN(toy_list); i++) {
    int fl = toy_list[i].flags;
    if (fl & TOYMASK_LOCATION) {
      if (toys.argv[1]) {
        int j;
        for (j=0; toy_paths[j]; j++)
          if (fl & (1<<j)) len += printf("%s", toy_paths[j]);
      }
      len += printf("%s",toy_list[i].name);
      if (++len > 65) len = 0;
      xputc(len ? ' ' : '\n');
    }
  }
  xputc('\n');
}

int main(int argc, char *argv[])
{
  if (CFG_TOYBOX) {
    // Trim path off of command name
    *argv = basename(*argv);

    // Call the multiplexer, adjusting this argv[] to be its' argv[1].
    // (It will adjust it back before calling toy_exec().)
    toys.argv = argv-1;
    toybox_main();
  } else {
    // a single toybox command built standalone with no multiplexer
    toy_singleinit(toy_list, argv);
    toy_list->toy_main();
    if (fflush(NULL) || ferror(stdout)) perror_exit("write");
  }

  return toys.exitval;
}