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 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, "toybox")) 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
unknown(char * name)63 static void unknown(char *name)
64 {
65 toys.exitval = 127;
66 toys.which = toy_list;
67 error_exit("Unknown command %s", name);
68 }
69
70 // Setup toybox global state for this command.
toy_singleinit(struct toy_list * which,char * argv[])71 static void toy_singleinit(struct toy_list *which, char *argv[])
72 {
73 toys.which = which;
74 toys.argv = argv;
75 toys.toycount = ARRAY_LEN(toy_list);
76
77 // Parse --help and --version for (almost) all commands
78 if (CFG_TOYBOX_HELP_DASHDASH && !(which->flags & TOYFLAG_NOHELP) && argv[1]) {
79 if (!strcmp(argv[1], "--help")) {
80 if (CFG_TOYBOX && toys.which == toy_list && toys.argv[2])
81 if (!(toys.which = toy_find(toys.argv[2]))) unknown(toys.argv[2]);
82 show_help(stdout, 1);
83 xexit();
84 }
85
86 if (!strcmp(argv[1], "--version")) {
87 xputs("toybox "TOYBOX_VERSION);
88 xexit();
89 }
90 }
91
92 if (NEED_OPTIONS && which->options) get_optflags();
93 else {
94 toys.optargs = argv+1;
95 for (toys.optc = 0; toys.optargs[toys.optc]; toys.optc++);
96 }
97
98 if (!(which->flags & TOYFLAG_NOFORK)) {
99 toys.old_umask = umask(0);
100 if (!(which->flags & TOYFLAG_UMASK)) umask(toys.old_umask);
101 if (CFG_TOYBOX_I18N) {
102 // Deliberately try C.UTF-8 before the user's locale to work around users
103 // that choose non-UTF-8 locales. macOS doesn't support C.UTF-8 though.
104 if (!setlocale(LC_CTYPE, "C.UTF-8")) setlocale(LC_CTYPE, "");
105 }
106 setlinebuf(stdout);
107 }
108 }
109
110 // Full init needed by multiplexer or reentrant calls, calls singleinit at end
toy_init(struct toy_list * which,char * argv[])111 void toy_init(struct toy_list *which, char *argv[])
112 {
113 void *oldwhich = toys.which;
114
115 // Drop permissions for non-suid commands.
116
117 if (CFG_TOYBOX_SUID) {
118 if (!toys.which) toys.which = toy_list;
119
120 uid_t uid = getuid(), euid = geteuid();
121
122 if (!(which->flags & TOYFLAG_STAYROOT)) {
123 if (uid != euid) {
124 if (setuid(uid)) perror_exit("setuid %d->%d", euid, uid); // drop root
125 euid = uid;
126 toys.wasroot++;
127 }
128 } else if (CFG_TOYBOX_DEBUG && uid && which != toy_list)
129 error_msg("Not installed suid root");
130
131 if ((which->flags & TOYFLAG_NEEDROOT) && euid) help_exit("Not root");
132 }
133
134 // Free old toys contents (to be reentrant), but leave rebound if any
135 // don't blank old optargs if our new argc lives in the old optargs.
136 if (argv<toys.optargs || argv>toys.optargs+toys.optc) free(toys.optargs);
137 memset(&toys, 0, offsetof(struct toy_context, rebound));
138 if (oldwhich) memset(&this, 0, sizeof(this));
139
140 // Continue to portion of init needed by standalone commands
141 toy_singleinit(which, argv);
142 }
143
144 // Run an internal toybox command.
145 // Only returns if it can't run command internally, otherwise xexit() when done.
toy_exec_which(struct toy_list * which,char * argv[])146 void toy_exec_which(struct toy_list *which, char *argv[])
147 {
148 // Return if we can't find it (which includes no multiplexer case),
149 if (!which) return;
150
151 // Return if stack depth getting noticeable (proxy for leaked heap, etc).
152
153 // Compiler writers have decided subtracting char * is undefined behavior,
154 // so convert to integers. (LP64 says sizeof(long)==sizeof(pointer).)
155 // Signed typecast so stack growth direction is irrelevant: we're measuring
156 // the distance between two pointers on the same stack, hence the labs().
157 if (!CFG_TOYBOX_NORECURSE && toys.stacktop)
158 if (labs((long)toys.stacktop-(long)&which)>6000) return;
159
160 // Return if we need to re-exec to acquire root via suid bit.
161 if (toys.which && (which->flags&TOYFLAG_ROOTONLY) && toys.wasroot) return;
162
163 // Run command
164 toy_init(which, argv);
165 if (toys.which) toys.which->toy_main();
166 xexit();
167 }
168
169 // Lookup internal toybox command to run via argv[0]
toy_exec(char * argv[])170 void toy_exec(char *argv[])
171 {
172 toy_exec_which(toy_find(basename(*argv)), argv);
173 }
174
175 // Multiplexer command, first argument is command to run, rest are args to that.
176 // If first argument starts with - output list of command install paths.
toybox_main(void)177 void toybox_main(void)
178 {
179 static char *toy_paths[] = {"usr/","bin/","sbin/",0};
180 int i, len = 0;
181
182 // fast path: try to exec immediately.
183 // (Leave toys.which null to disable suid return logic.)
184 // Try dereferencing one layer of symlink
185 if (toys.argv[1]) {
186 toy_exec(toys.argv+1);
187 if (0<readlink(toys.argv[1], libbuf, sizeof(libbuf))) {
188 struct toy_list *tl= toy_find(basename(libbuf));
189
190 if (tl == toy_list) unknown(basename(toys.argv[1]));
191 else toy_exec_which(tl, toys.argv+1);
192 }
193 }
194
195 // For early error reporting
196 toys.which = toy_list;
197
198 if (toys.argv[1] && toys.argv[1][0] != '-') unknown(toys.argv[1]);
199
200 // Output list of command.
201 for (i = 1; i<ARRAY_LEN(toy_list); i++) {
202 int fl = toy_list[i].flags;
203 if (fl & TOYMASK_LOCATION) {
204 if (toys.argv[1]) {
205 int j;
206 for (j = 0; toy_paths[j]; j++)
207 if (fl & (1<<j)) len += printf("%s", toy_paths[j]);
208 }
209 len += printf("%s",toy_list[i].name);
210 if (++len > 65) len = 0;
211 xputc(len ? ' ' : '\n');
212 }
213 }
214 xputc('\n');
215 }
216
main(int argc,char * argv[])217 int main(int argc, char *argv[])
218 {
219 // don't segfault if our environment is crazy
220 if (!*argv) return 127;
221
222 // Snapshot stack location so we can detect recursion depth later.
223 // Nommu has special reentry path, !stacktop = "vfork/exec self happened"
224 if (!CFG_TOYBOX_FORK && (0x80 & **argv)) **argv &= 0x7f;
225 else {
226 int stack_start; // here so probe var won't permanently eat stack
227
228 toys.stacktop = &stack_start;
229 }
230
231 // Android before O had non-default SIGPIPE, 7 years = remove in Sep 2024.
232 if (CFG_TOYBOX_ON_ANDROID) signal(SIGPIPE, SIG_DFL);
233
234 if (CFG_TOYBOX) {
235 // Call the multiplexer with argv[] as its arguments so it can toy_find()
236 toys.argv = argv-1;
237 toybox_main();
238 } else {
239 // single command built standalone with no multiplexer is first list entry
240 toy_singleinit(toy_list, argv);
241 toy_list->toy_main();
242 }
243
244 xexit();
245 }
246