1 /* Toybox infrastructure.
2 *
3 * Copyright 2006 Rob Landley <rob@landley.net>
4 */
5
6 #include "toys.h"
7
8 #ifndef TOYBOX_VERSION
9 #define TOYBOX_VERSION "0.7.0"
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
toy_find(char * name)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 // 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
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(stdout);
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 // Full init needed by multiplexer or reentrant calls, calls singleinit at end
toy_init(struct toy_list * which,char * argv[])97 void toy_init(struct toy_list *which, char *argv[])
98 {
99 void *oldwhich = toys.which;
100
101 // Drop permissions for non-suid commands.
102
103 if (CFG_TOYBOX_SUID) {
104 if (!toys.which) toys.which = toy_list;
105
106 uid_t uid = getuid(), euid = geteuid();
107
108 if (!(which->flags & TOYFLAG_STAYROOT)) {
109 if (uid != euid) {
110 if (setuid(uid)) perror_exit("setuid %d->%d", euid, uid); // drop root
111 euid = uid;
112 toys.wasroot++;
113 }
114 } else if (CFG_TOYBOX_DEBUG && uid && which != toy_list)
115 error_msg("Not installed suid root");
116
117 if ((which->flags & TOYFLAG_NEEDROOT) && euid) help_exit("Not root");
118 }
119
120 // Free old toys contents (to be reentrant), but leave rebound if any
121 // don't blank old optargs if our new argc lives in the old optargs.
122 if (argv<toys.optargs || argv>toys.optargs+toys.optc) free(toys.optargs);
123 memset(&toys, 0, offsetof(struct toy_context, rebound));
124 if (oldwhich) memset(&this, 0, sizeof(this));
125
126 // Continue to portion of init needed by standalone commands
127 toy_singleinit(which, argv);
128 }
129
130 // Like exec() but runs an internal toybox command instead of another file.
131 // Only returns if it can't run command internally, otherwise exit() when done.
toy_exec(char * argv[])132 void toy_exec(char *argv[])
133 {
134 struct toy_list *which;
135
136 // Return if we can't find it (which includes no multiplexer case),
137 if (!(which = toy_find(*argv))) return;
138
139 // Return if stack depth getting noticeable (proxy for leaked heap, etc).
140 if (toys.stacktop && labs((char *)toys.stacktop-(char *)&which)>6000)
141 return;
142
143 // Return if we need to re-exec to acquire root via suid bit.
144 if (toys.which && (which->flags&TOYFLAG_ROOTONLY) && toys.wasroot) return;
145
146 // Run command
147 toy_init(which, argv);
148 if (toys.which) toys.which->toy_main();
149 xexit();
150 }
151
152 // Multiplexer command, first argument is command to run, rest are args to that.
153 // If first argument starts with - output list of command install paths.
toybox_main(void)154 void toybox_main(void)
155 {
156 static char *toy_paths[]={"usr/","bin/","sbin/",0};
157 int i, len = 0;
158
159 // fast path: try to exec immediately.
160 // (Leave toys.which null to disable suid return logic.)
161 if (toys.argv[1]) toy_exec(toys.argv+1);
162
163 // For early error reporting
164 toys.which = toy_list;
165
166 if (toys.argv[1]) {
167 if (!strcmp("--version", toys.argv[1])) {
168 xputs(TOYBOX_VERSION);
169 xexit();
170 }
171 if (toys.argv[1][0] != '-') {
172 toys.exitval = 127;
173 error_exit("Unknown command %s", toys.argv[1]);
174 }
175 }
176
177 // Output list of command.
178 for (i=1; i<ARRAY_LEN(toy_list); i++) {
179 int fl = toy_list[i].flags;
180 if (fl & TOYMASK_LOCATION) {
181 if (toys.argv[1]) {
182 int j;
183 for (j=0; toy_paths[j]; j++)
184 if (fl & (1<<j)) len += printf("%s", toy_paths[j]);
185 }
186 len += printf("%s",toy_list[i].name);
187 if (++len > 65) len = 0;
188 xputc(len ? ' ' : '\n');
189 }
190 }
191 xputc('\n');
192 }
193
main(int argc,char * argv[])194 int main(int argc, char *argv[])
195 {
196 if (!*argv) return 127;
197
198 // Snapshot stack location so we can detect recursion depth later.
199 // This is its own block so probe doesn't permanently consume stack.
200 else {
201 int stack;
202
203 toys.stacktop = &stack;
204 }
205 *argv = basename_r(*argv);
206
207 // If nommu can't fork, special reentry path.
208 // Use !stacktop to signal "vfork happened", both before and after xexec()
209 if (!CFG_TOYBOX_FORK) {
210 if (0x80 & **argv) {
211 **argv &= 0x7f;
212 toys.stacktop = 0;
213 }
214 }
215
216 if (CFG_TOYBOX) {
217 // Call the multiplexer, adjusting this argv[] to be its' argv[1].
218 // (It will adjust it back before calling toy_exec().)
219 toys.argv = argv-1;
220 toybox_main();
221 } else {
222 // a single toybox command built standalone with no multiplexer
223 toy_singleinit(toy_list, argv);
224 toy_list->toy_main();
225 }
226
227 xexit();
228 }
229