1 /* Toybox infrastructure.
2 *
3 * Copyright 2006 Rob Landley <rob@landley.net>
4 */
5
6 #include "toys.h"
7
8 // Populate toy_list[].
9
10 #undef NEWTOY
11 #undef OLDTOY
12 #define NEWTOY(name, opts, flags) {#name, name##_main, OPTSTR_##name, flags},
13 #define OLDTOY(name, oldname, flags) \
14 {#name, oldname##_main, OPTSTR_##oldname, flags},
15
16 struct toy_list toy_list[] = {
17 #include "generated/newtoys.h"
18 };
19
20 // global context for this command.
21
22 struct toy_context toys;
23 union global_union this;
24 char *toybox_version = TOYBOX_VERSION, toybuf[4096], libbuf[4096];
25
toy_find(char * name)26 struct toy_list *toy_find(char *name)
27 {
28 int top, bottom, middle;
29
30 if (!CFG_TOYBOX || strchr(name, '/')) return 0;
31
32 // Multiplexer name works as prefix, else skip first entry (it's out of order)
33 if (!toys.which && strstart(&name, toy_list->name)) return toy_list;
34 bottom = 1;
35
36 // Binary search to find this command.
37 top = ARRAY_LEN(toy_list)-1;
38 for (;;) {
39 int result;
40
41 middle = (top+bottom)/2;
42 if (middle<bottom || middle>top) return 0;
43 result = strcmp(name,toy_list[middle].name);
44 if (!result) return toy_list+middle;
45 if (result<0) top = --middle;
46 else bottom = ++middle;
47 }
48 }
49
50 // Figure out whether or not anything is using the option parsing logic,
51 // because the compiler can't figure out whether or not to optimize it away
52 // on its' own. NEED_OPTIONS becomes a constant allowing if() to optimize
53 // stuff out via dead code elimination.
54
55 #undef NEWTOY
56 #undef OLDTOY
57 #define NEWTOY(name, opts, flags) opts ||
58 #define OLDTOY(name, oldname, flags) OPTSTR_##oldname ||
59 static const int NEED_OPTIONS =
60 #include "generated/newtoys.h"
61 0; // Ends the opts || opts || opts...
62
63 // Populate help text array
64
65 #undef NEWTOY
66 #undef OLDTOY
67 #define NEWTOY(name,opt,flags) HELP_##name "\0"
68 #if CFG_TOYBOX
69 #define OLDTOY(name,oldname,flags) "\xff" #oldname "\0"
70 #else
71 #define OLDTOY(name, oldname, flags) HELP_##oldname "\0"
72 #endif
73
74 #include "generated/help.h"
75 static char *help_data =
76 #include "generated/newtoys.h"
77 ;
78
show_help(FILE * out,int flags)79 void show_help(FILE *out, int flags)
80 {
81 int i = toys.which-toy_list;
82 char *s, *ss;
83
84 if (CFG_TOYBOX_HELP) {
85 if (flags & HELP_HEADER)
86 fprintf(out, "Toybox %s"USE_TOYBOX(" multicall binary")"%s\n\n",
87 toybox_version, (CFG_TOYBOX && i) ? " (see toybox --help)"
88 : " (see https://landley.net/toybox)");
89
90 for (;;) {
91 s = help_data;
92 while (i--) s += strlen(s) + 1;
93 // If it's an alias, restart search for real name
94 if (*s != 255) break;
95 i = toy_find(++s)-toy_list;
96 if ((flags & HELP_SEE) && toy_list[i].flags) {
97 if (flags & HELP_HTML) fprintf(out, "See <a href=#%s>%s</a>\n", s, s);
98 else fprintf(out, "%s see %s\n", toys.which->name, s);
99
100 return;
101 }
102 }
103
104 if (!(flags & HELP_USAGE)) fprintf(out, "%s\n", s);
105 else {
106 strstart(&s, "usage: ");
107 for (ss = s; *ss && *ss!='\n'; ss++);
108 fprintf(out, "%.*s\n", (int)(ss-s), s);
109 }
110 }
111 }
112
unknown(char * name)113 static void unknown(char *name)
114 {
115 toys.exitval = 127;
116 toys.which = toy_list;
117 help_exit("Unknown command %s", name);
118 }
119
120 // Parse --help and --version for (almost) all commands
check_help(char ** arg)121 void check_help(char **arg)
122 {
123 if (!CFG_TOYBOX_HELP_DASHDASH || !*arg) return;
124 if (!CFG_TOYBOX || toys.which != toy_list)
125 if (toys.which->flags&TOYFLAG_NOHELP) return;
126
127 if (!strcmp(*arg, "--help")) {
128 if (CFG_TOYBOX && toys.which == toy_list && arg[1]) {
129 toys.which = 0;
130 if (!(toys.which = toy_find(arg[1]))) unknown(arg[1]);
131 }
132 show_help(stdout, HELP_HEADER);
133 xexit();
134 }
135
136 if (!strcmp(*arg, "--version")) {
137 xprintf("toybox %s\n", toybox_version);
138 xexit();
139 }
140 }
141
142 // Setup toybox global state for this command.
toy_singleinit(struct toy_list * which,char * argv[])143 void toy_singleinit(struct toy_list *which, char *argv[])
144 {
145 toys.which = which;
146 toys.argv = argv;
147 toys.toycount = ARRAY_LEN(toy_list);
148
149 if (NEED_OPTIONS && which->options) get_optflags();
150 else {
151 check_help(toys.optargs = argv+1);
152 for (toys.optc = 0; toys.optargs[toys.optc]; toys.optc++);
153 }
154
155 // Setup we only want to do once: skip for multiplexer or NOFORK reentry
156 if (!(CFG_TOYBOX && which == toy_list) && !(which->flags & TOYFLAG_NOFORK)) {
157 toys.old_umask = umask(0);
158 if (!(which->flags & TOYFLAG_UMASK)) umask(toys.old_umask);
159
160 // Try user's locale, but if that isn't UTF-8 merge in a UTF-8 locale's
161 // character type data. (Fall back to en_US for MacOS.)
162 setlocale(LC_CTYPE, "");
163 if (strcmp("UTF-8", nl_langinfo(CODESET)))
164 uselocale(newlocale(LC_CTYPE_MASK, "C.UTF-8", 0) ? :
165 newlocale(LC_CTYPE_MASK, "en_US.UTF-8", 0));
166
167 setvbuf(stdout, 0, (which->flags & TOYFLAG_LINEBUF) ? _IOLBF : _IONBF, 0);
168 }
169 }
170
171 // Full init needed by multiplexer or reentrant calls, calls singleinit at end
toy_init(struct toy_list * which,char * argv[])172 void toy_init(struct toy_list *which, char *argv[])
173 {
174 void *oldwhich = toys.which;
175
176 // Drop permissions for non-suid commands.
177 if (CFG_TOYBOX_SUID) {
178 if (!toys.which) toys.which = toy_list;
179
180 uid_t uid = getuid(), euid = geteuid();
181
182 if (!(which->flags & TOYFLAG_STAYROOT)) {
183 if (uid != euid) {
184 if (setuid(uid)) perror_exit("setuid %d->%d", euid, uid); // drop root
185 euid = uid;
186 toys.wasroot++;
187 }
188 } else if (CFG_TOYBOX_DEBUG && uid && which != toy_list)
189 error_msg("Not installed suid root");
190
191 if ((which->flags & TOYFLAG_NEEDROOT) && euid) {
192 toys.which = which;
193 check_help(argv+1);
194 help_exit("Not root");
195 }
196 }
197
198 // Free old toys contents (to be reentrant), but leave rebound if any
199 // don't blank old optargs if our new argc lives in the old optargs.
200 if (argv<toys.optargs || argv>toys.optargs+toys.optc) free(toys.optargs);
201 memset(&toys, 0, offsetof(struct toy_context, rebound));
202 if (oldwhich) memset(&this, 0, sizeof(this));
203
204 // Continue to portion of init needed by standalone commands
205 toy_singleinit(which, argv);
206 }
207
208 // Run an internal toybox command.
209 // Only returns if it can't run command internally, otherwise xexit() when done.
toy_exec_which(struct toy_list * which,char * argv[])210 static void toy_exec_which(struct toy_list *which, char *argv[])
211 {
212 // Return if we can't find it (which includes no multiplexer case),
213 if (!which || (which->flags&TOYFLAG_NOFORK)) return;
214
215 // Return if stack depth getting noticeable (proxy for leaked heap, etc).
216
217 // Compiler writers have decided subtracting char * is undefined behavior,
218 // so convert to integers. (LP64 says sizeof(long)==sizeof(pointer).)
219 // Signed typecast so stack growth direction is irrelevant: we're measuring
220 // the distance between two pointers on the same stack, hence the labs().
221 if (!CFG_TOYBOX_NORECURSE && toys.stacktop)
222 if (labs((long)toys.stacktop-(long)&which)>6000) return;
223
224 // Return if we need to re-exec to acquire root via suid bit.
225 if (toys.which && (which->flags&TOYFLAG_ROOTONLY) && toys.wasroot) return;
226
227 // Run command
228 toy_init(which, argv);
229 if (toys.which) toys.which->toy_main();
230 xexit();
231 }
232
233 // Lookup internal toybox command to run via argv[0]
toy_exec(char * argv[])234 void toy_exec(char *argv[])
235 {
236 toy_exec_which(toy_find(*argv), argv);
237 }
238
239 // Multiplexer command, first argument is command to run, rest are args to that.
240 // If first argument starts with - output list of command install paths.
toybox_main(void)241 void toybox_main(void)
242 {
243 char *toy_paths[] = {"usr/", "bin/", "sbin/", 0}, *s = toys.argv[1];
244 int i, len = 0;
245 unsigned width = 80;
246
247 // fast path: try to exec immediately.
248 // (Leave toys.which null to disable suid return logic.)
249 // Try dereferencing symlinks until we hit a recognized name
250 while (s) {
251 char *ss = basename(s);
252 struct toy_list *tl = toy_find(ss);
253
254 if (tl==toy_list && s!=toys.argv[1]) unknown(ss);
255 toy_exec_which(tl, toys.argv+1);
256 s = (0<readlink(s, libbuf, sizeof(libbuf))) ? libbuf : 0;
257 }
258
259 // For early error reporting
260 toys.which = toy_list;
261
262 if (toys.argv[1] && strcmp(toys.argv[1], "--long")) unknown(toys.argv[1]);
263
264 // Output list of commands.
265 terminal_size(&width, 0);
266 for (i = 1; i<ARRAY_LEN(toy_list); i++) {
267 int fl = toy_list[i].flags;
268 if (fl & TOYMASK_LOCATION) {
269 if (toys.argv[1]) {
270 int j;
271 for (j = 0; toy_paths[j]; j++)
272 if (fl & (1<<j)) len += printf("%s", toy_paths[j]);
273 }
274 len += printf("%s",toy_list[i].name);
275 if (++len > width-15) len = 0;
276 xputc(len ? ' ' : '\n');
277 }
278 }
279 xputc('\n');
280 }
281
main(int argc,char * argv[])282 int main(int argc, char *argv[])
283 {
284 // don't segfault if our environment is crazy
285 if (!*argv) return 127;
286
287 // Snapshot stack location so we can detect recursion depth later.
288 // Nommu has special reentry path, !stacktop = "vfork/exec self happened"
289 if (!CFG_TOYBOX_FORK && (0x80 & **argv)) **argv &= 0x7f;
290 else {
291 int stack_start; // here so probe var won't permanently eat stack
292
293 toys.stacktop = &stack_start;
294 }
295
296 // Android before O had non-default SIGPIPE, 7 years = remove in Sep 2024.
297 if (CFG_TOYBOX_ON_ANDROID) signal(SIGPIPE, SIG_DFL);
298
299 if (CFG_TOYBOX) {
300 // Call the multiplexer with argv[] as its arguments so it can toy_find()
301 toys.argv = argv-1;
302 toybox_main();
303 } else {
304 // single command built standalone with no multiplexer is first list entry
305 toy_singleinit(toy_list, argv);
306 toy_list->toy_main();
307 }
308
309 xexit();
310 }
311