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main.c
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main.c
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/* Toybox infrastructure.
*
* Copyright 2006 Rob Landley <[email protected]>
*/
#include "toys.h"
// Populate toy_list[].
#undef NEWTOY
#undef OLDTOY
#define NEWTOY(name, opts, flags) {#name, name##_main, OPTSTR_##name, flags},
#define OLDTOY(name, oldname, flags) \
{#name, oldname##_main, OPTSTR_##oldname, flags},
struct toy_list toy_list[] = {
#include "generated/newtoys.h"
};
// global context for this command.
struct toy_context toys;
union global_union this;
char *toybox_version = TOYBOX_VERSION, toybuf[4096], libbuf[4096];
struct toy_list *toy_find(char *name)
{
int top, bottom, middle;
if (!CFG_TOYBOX || strchr(name, '/')) return 0;
// Multiplexer name works as prefix, else skip first entry (it's out of order)
if (!toys.which && strstart(&name, toy_list->name)) 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 0;
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, flags) OPTSTR_##oldname ||
static const int NEED_OPTIONS =
#include "generated/newtoys.h"
0; // Ends the opts || opts || opts...
// Populate help text array
#undef NEWTOY
#undef OLDTOY
#define NEWTOY(name,opt,flags) HELP_##name "\0"
#if CFG_TOYBOX
#define OLDTOY(name,oldname,flags) "\xff" #oldname "\0"
#else
#define OLDTOY(name, oldname, flags) HELP_##oldname "\0"
#endif
#include "generated/help.h"
static const char help_data[] =
#include "generated/newtoys.h"
;
#if CFG_TOYBOX_ZHELP
#include "generated/zhelp.h"
#else
static char *zhelp_data = 0;
#define ZHELP_LEN 0
#endif
void show_help(FILE *out, int flags)
{
int i = toys.which-toy_list;
char *s, *ss, *hd;
if (!CFG_TOYBOX_HELP) return;
if (CFG_TOYBOX_ZHELP)
gunzip_mem(zhelp_data, sizeof(zhelp_data), hd = xmalloc(ZHELP_LEN),
ZHELP_LEN);
else hd = (void *)help_data;
if (flags & HELP_HEADER)
fprintf(out, "Toybox %s"USE_TOYBOX(" multicall binary")"%s\n\n",
toybox_version, (CFG_TOYBOX && i) ? " (see toybox --help)"
: " (see https://landley.net/toybox)");
for (;;) {
s = (void *)help_data;
while (i--) s += strlen(s) + 1;
// If it's an alias, restart search for real name
if (*s != 255) break;
i = toy_find(++s)-toy_list;
if ((flags & HELP_SEE) && toy_list[i].flags) {
if (flags & HELP_HTML) fprintf(out, "See <a href=#%s>%s</a>\n", s, s);
else fprintf(out, "%s see %s\n", toys.which->name, s);
return;
}
}
if (!(flags & HELP_USAGE)) fprintf(out, "%s\n", s);
else {
strstart(&s, "usage: ");
for (ss = s; *ss && *ss!='\n'; ss++);
fprintf(out, "%.*s\n", (int)(ss-s), s);
}
}
static void unknown(char *name)
{
toys.exitval = 127;
toys.which = toy_list;
help_exit("Unknown command %s", name);
}
// Parse --help and --version for (almost) all commands
void check_help(char **arg)
{
long flags = toys.which->flags;
if (!CFG_TOYBOX_HELP_DASHDASH || !*arg) return;
if (!CFG_TOYBOX || toys.which!=toy_list) if (flags&TOYFLAG_NOHELP) return;
if (!strcmp(*arg, "--help")) {
if (CFG_TOYBOX && toys.which == toy_list && arg[1]) {
toys.which = 0;
if (!(toys.which = toy_find(arg[1]))) unknown(arg[1]);
}
show_help(stdout, HELP_HEADER);
xexit();
}
if (!strcmp(*arg, "--version")) {
// Lie to autoconf when it asks stupid questions, so configure regexes
// that look for "GNU sed version %f" greater than some old buggy number
// don't fail us for not matching their narrow expectations.
*toybuf = 0;
if (flags&TOYFLAG_AUTOCONF)
sprintf(toybuf, " (is not GNU %s 9.0)", toys.which->name);
xprintf("toybox %s%s\n", toybox_version, toybuf);
xexit();
}
}
// Setup toybox global state for this command.
void toy_singleinit(struct toy_list *which, char *argv[])
{
toys.which = which;
toys.argv = argv;
toys.toycount = ARRAY_LEN(toy_list);
if (NEED_OPTIONS && which->options) get_optflags();
else {
check_help(toys.optargs = argv+1);
for (toys.optc = 0; toys.optargs[toys.optc]; toys.optc++);
}
// Setup we only want to do once: skip for multiplexer or NOFORK reentry
if (!(CFG_TOYBOX && which == toy_list) && !(which->flags & TOYFLAG_NOFORK)) {
char *buf = 0;
int btype = _IOFBF;
toys.old_umask = umask(0);
if (!(which->flags & TOYFLAG_UMASK)) umask(toys.old_umask);
// Try user's locale, but if that isn't UTF-8 merge in a UTF-8 locale's
// character type data. (Fall back to en_US for MacOS.)
setlocale(LC_CTYPE, "");
if (strcmp("UTF-8", nl_langinfo(CODESET)))
uselocale(newlocale(LC_CTYPE_MASK, "C.UTF-8", 0) ? :
newlocale(LC_CTYPE_MASK, "en_US.UTF-8", 0));
if (which->flags & TOYFLAG_LINEBUF) btype = _IOLBF;
else if (which->flags & TOYFLAG_NOBUF) btype = _IONBF;
else buf = xmalloc(4096);
setvbuf(stdout, buf, btype, buf ? 4096 : 0);
}
}
// Full init needed by multiplexer or reentrant calls, calls singleinit at end
void toy_init(struct toy_list *which, char *argv[])
{
void *oldwhich = toys.which;
// Drop permissions for non-suid commands.
if (CFG_TOYBOX_SUID) {
if (!toys.which) toys.which = toy_list;
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
euid = uid;
toys.wasroot++;
}
} else if (CFG_TOYBOX_DEBUG && uid && which != toy_list)
error_msg("Not installed suid root");
if ((which->flags & TOYFLAG_NEEDROOT) && euid) {
toys.which = which;
check_help(argv+1);
help_exit("Not root");
}
}
memset(&toys, 0, offsetof(struct toy_context, rebound));
if (oldwhich) memset(&this, 0, sizeof(this));
// Continue to portion of init needed by standalone commands
toy_singleinit(which, argv);
}
// Run an internal toybox command.
// Only returns if it can't run command internally, otherwise xexit() when done.
void toy_exec_which(struct toy_list *which, char *argv[])
{
// Return if we can't find it (which includes no multiplexer case),
if (!which || (which->flags&TOYFLAG_NOFORK)) return;
// Return if stack depth getting noticeable (proxy for leaked heap, etc).
// Compiler writers have decided subtracting char * is undefined behavior,
// so convert to integers. (LP64 says sizeof(long)==sizeof(pointer).)
// Signed typecast so stack growth direction is irrelevant: we're measuring
// the distance between two pointers on the same stack, hence the labs().
if (!CFG_TOYBOX_NORECURSE && toys.stacktop)
if (labs((long)toys.stacktop-(long)&which)>24000) return;
// Return if we need to re-exec to acquire root via suid bit.
if (toys.which && (which->flags&TOYFLAG_ROOTONLY) && toys.wasroot) return;
// Run command
toy_init(which, argv);
if (toys.which) toys.which->toy_main();
xexit();
}
// Lookup internal toybox command to run via argv[0]
void toy_exec(char *argv[])
{
toy_exec_which(toy_find(*argv), argv);
}
// 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)
{
char *toy_paths[] = {"usr/", "bin/", "sbin/", 0}, *s = toys.argv[1];
int i, len = 0;
unsigned width = 80;
// fast path: try to exec immediately.
// (Leave toys.which null to disable suid return logic.)
// Try dereferencing symlinks until we hit a recognized name
while (s) {
char *ss = basename(s);
struct toy_list *tl = toy_find(ss);
if (tl==toy_list && s!=toys.argv[1]) unknown(ss);
toy_exec_which(tl, toys.argv+1);
s = (0<readlink(s, libbuf, sizeof(libbuf))) ? libbuf : 0;
}
// For early error reporting
toys.which = toy_list;
if (toys.argv[1] && strcmp(toys.argv[1], "--long")) unknown(toys.argv[1]);
// Output list of commands.
terminal_size(&width, 0);
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 > width-15) len = 0;
xputc(len ? ' ' : '\n');
}
}
xputc('\n');
}
int main(int argc, char *argv[])
{
// don't segfault if our environment is crazy
// TODO mooted by kernel commit dcd46d897adb7 5.17 kernel Jan 2022
if (!*argv) return 127;
// Snapshot stack location so we can detect recursion depth later.
// Nommu has special reentry path, !stacktop = "vfork/exec self happened"
if (!CFG_TOYBOX_FORK && (0x80 & **argv)) **argv &= 0x7f;
else {
int stack_start; // here so probe var won't permanently eat stack
toys.stacktop = &stack_start;
}
// Android before O had non-default SIGPIPE, 7 years = remove in Sep 2024.
if (CFG_TOYBOX_ON_ANDROID) signal(SIGPIPE, SIG_DFL);
if (CFG_TOYBOX) {
// Call the multiplexer with argv[] as its arguments so it can toy_find()
toys.argv = argv-1;
toybox_main();
} else {
// single command built standalone with no multiplexer is first list entry
toy_singleinit(toy_list, argv);
toy_list->toy_main();
}
xexit();
}