blob: 8daa2330902962d47d02c3b58cb4468e5ff5846d [file] [log] [blame]
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +00001/* vi: set sw=4 ts=4: */
2/*
Denis Vlasenko724d1962007-10-10 14:41:07 +00003 * Utility routines.
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +00004 *
Denis Vlasenko724d1962007-10-10 14:41:07 +00005 * Copyright (C) tons of folks. Tracking down who wrote what
6 * isn't something I'm going to worry about... If you wrote something
7 * here, please feel free to acknowledge your work.
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +00008 *
Denis Vlasenko724d1962007-10-10 14:41:07 +00009 * Based in part on code from sash, Copyright (c) 1999 by David I. Bell
Denys Vlasenko0ef64bd2010-08-16 20:14:46 +020010 * Permission has been granted to redistribute this code under GPL.
Denis Vlasenko724d1962007-10-10 14:41:07 +000011 *
Denys Vlasenko0ef64bd2010-08-16 20:14:46 +020012 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +000013 */
14
Denis Vlasenko79cedcb2008-04-08 21:13:28 +000015/* We are trying to not use printf, this benefits the case when selected
16 * applets are really simple. Example:
17 *
18 * $ ./busybox
19 * ...
20 * Currently defined functions:
21 * basename, false, true
22 *
23 * $ size busybox
24 * text data bss dec hex filename
25 * 4473 52 72 4597 11f5 busybox
26 *
27 * FEATURE_INSTALLER or FEATURE_SUID will still link printf routines in. :(
28 */
Denys Vlasenkoc1947f12009-10-23 01:30:26 +020029#include "busybox.h"
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +000030#include <assert.h>
Denys Vlasenko1f7c1672009-09-06 02:12:28 +020031#include <malloc.h>
Denys Vlasenko3d0e7792010-03-29 11:02:00 +020032/* Try to pull in PAGE_SIZE */
33#ifdef __linux__
34# include <sys/user.h>
35#endif
36#ifdef __GNU__ /* Hurd */
37# include <mach/vm_param.h>
38#endif
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +000039
40
41/* Declare <applet>_main() */
42#define PROTOTYPES
43#include "applets.h"
44#undef PROTOTYPES
45
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +000046
Denis Vlasenko32b2a9f2008-02-22 22:43:22 +000047/* Include generated applet names, pointers to <applet>_main, etc */
Denis Vlasenko1aa7e472007-11-28 06:49:03 +000048#include "applet_tables.h"
Denis Vlasenko468aea22008-04-01 14:47:57 +000049/* ...and if applet_tables generator says we have only one applet... */
50#ifdef SINGLE_APPLET_MAIN
Denys Vlasenko0e5ba082010-06-05 23:11:07 +020051# undef ENABLE_FEATURE_INDIVIDUAL
52# define ENABLE_FEATURE_INDIVIDUAL 1
53# undef IF_FEATURE_INDIVIDUAL
54# define IF_FEATURE_INDIVIDUAL(...) __VA_ARGS__
Denis Vlasenko468aea22008-04-01 14:47:57 +000055#endif
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +000056
57
Denys Vlasenko0e5ba082010-06-05 23:11:07 +020058#include "usage_compressed.h"
59
60#if ENABLE_SHOW_USAGE && !ENABLE_FEATURE_COMPRESS_USAGE
61static const char usage_messages[] ALIGN1 = UNPACKED_USAGE;
62#else
63# define usage_messages 0
Denys Vlasenko1fcbff22010-06-26 02:40:08 +020064#endif
Denys Vlasenko0e5ba082010-06-05 23:11:07 +020065
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +000066#if ENABLE_FEATURE_COMPRESS_USAGE
67
Denys Vlasenko5c296de2010-07-03 14:28:35 +020068static const char packed_usage[] ALIGN1 = { PACKED_USAGE };
Denys Vlasenko0e5ba082010-06-05 23:11:07 +020069# include "unarchive.h"
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +000070static const char *unpack_usage_messages(void)
71{
72 char *outbuf = NULL;
73 bunzip_data *bd;
74 int i;
75
76 i = start_bunzip(&bd,
77 /* src_fd: */ -1,
Denys Vlasenko263cff92009-08-20 23:34:01 +020078 /* inbuf: */ (void *)packed_usage,
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +000079 /* len: */ sizeof(packed_usage));
80 /* read_bunzip can longjmp to start_bunzip, and ultimately
81 * end up here with i != 0 on read data errors! Not trivial */
82 if (!i) {
83 /* Cannot use xmalloc: will leak bd in NOFORK case! */
Denys Vlasenko0e5ba082010-06-05 23:11:07 +020084 outbuf = malloc_or_warn(sizeof(UNPACKED_USAGE));
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +000085 if (outbuf)
Denys Vlasenko0e5ba082010-06-05 23:11:07 +020086 read_bunzip(bd, outbuf, sizeof(UNPACKED_USAGE));
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +000087 }
88 dealloc_bunzip(bd);
89 return outbuf;
90}
Denys Vlasenko0e5ba082010-06-05 23:11:07 +020091# define dealloc_usage_messages(s) free(s)
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +000092
93#else
94
Denys Vlasenko0e5ba082010-06-05 23:11:07 +020095# define unpack_usage_messages() usage_messages
96# define dealloc_usage_messages(s) ((void)(s))
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +000097
98#endif /* FEATURE_COMPRESS_USAGE */
99
100
Denis Vlasenkodefc1ea2008-06-27 02:52:20 +0000101void FAST_FUNC bb_show_usage(void)
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000102{
103 if (ENABLE_SHOW_USAGE) {
Denis Vlasenko468aea22008-04-01 14:47:57 +0000104#ifdef SINGLE_APPLET_STR
105 /* Imagine that this applet is "true". Dont suck in printf! */
106 const char *p;
107 const char *usage_string = p = unpack_usage_messages();
108
109 if (*p == '\b') {
Denis Vlasenko42404082008-11-24 13:42:24 +0000110 full_write2_str("No help available.\n\n");
Denis Vlasenko468aea22008-04-01 14:47:57 +0000111 } else {
Denis Vlasenko42404082008-11-24 13:42:24 +0000112 full_write2_str("Usage: "SINGLE_APPLET_STR" ");
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000113 full_write2_str(p);
114 full_write2_str("\n\n");
Denis Vlasenko468aea22008-04-01 14:47:57 +0000115 }
Denys Vlasenko630dde12009-08-30 19:57:49 +0200116 if (ENABLE_FEATURE_CLEAN_UP)
117 dealloc_usage_messages((char*)usage_string);
Denis Vlasenko468aea22008-04-01 14:47:57 +0000118#else
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000119 const char *p;
120 const char *usage_string = p = unpack_usage_messages();
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000121 int ap = find_applet_by_name(applet_name);
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000122
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000123 if (ap < 0) /* never happens, paranoia */
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000124 xfunc_die();
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000125 while (ap) {
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000126 while (*p++) continue;
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000127 ap--;
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000128 }
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000129 full_write2_str(bb_banner);
Denys Vlasenko630dde12009-08-30 19:57:49 +0200130 full_write2_str(" multi-call binary.\n");
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000131 if (*p == '\b')
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000132 full_write2_str("\nNo help available.\n\n");
133 else {
134 full_write2_str("\nUsage: ");
135 full_write2_str(applet_name);
136 full_write2_str(" ");
137 full_write2_str(p);
138 full_write2_str("\n\n");
139 }
Denys Vlasenko630dde12009-08-30 19:57:49 +0200140 if (ENABLE_FEATURE_CLEAN_UP)
141 dealloc_usage_messages((char*)usage_string);
Denis Vlasenko468aea22008-04-01 14:47:57 +0000142#endif
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000143 }
144 xfunc_die();
145}
146
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000147#if NUM_APPLETS > 8
Denis Vlasenko745cd172007-11-29 03:31:20 +0000148/* NB: any char pointer will work as well, not necessarily applet_names */
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000149static int applet_name_compare(const void *name, const void *v)
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000150{
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000151 int i = (const char *)v - applet_names;
152 return strcmp(name, APPLET_NAME(i));
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000153}
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000154#endif
Denis Vlasenkodefc1ea2008-06-27 02:52:20 +0000155int FAST_FUNC find_applet_by_name(const char *name)
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000156{
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000157#if NUM_APPLETS > 8
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000158 /* Do a binary search to find the applet entry given the name. */
Denis Vlasenko745cd172007-11-29 03:31:20 +0000159 const char *p;
160 p = bsearch(name, applet_names, ARRAY_SIZE(applet_main), 1, applet_name_compare);
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000161 if (!p)
162 return -1;
163 return p - applet_names;
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000164#else
165 /* A version which does not pull in bsearch */
166 int i = 0;
167 const char *p = applet_names;
168 while (i < NUM_APPLETS) {
169 if (strcmp(name, p) == 0)
170 return i;
171 p += strlen(p) + 1;
172 i++;
173 }
174 return -1;
175#endif
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000176}
177
178
Denis Vlasenko68404f12008-03-17 09:00:54 +0000179void lbb_prepare(const char *applet
Denis Vlasenko5e34ff22009-04-21 11:09:40 +0000180 IF_FEATURE_INDIVIDUAL(, char **argv))
Denis Vlasenko468aea22008-04-01 14:47:57 +0000181 MAIN_EXTERNALLY_VISIBLE;
182void lbb_prepare(const char *applet
Denis Vlasenko5e34ff22009-04-21 11:09:40 +0000183 IF_FEATURE_INDIVIDUAL(, char **argv))
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000184{
185#ifdef __GLIBC__
186 (*(int **)&bb_errno) = __errno_location();
Denis Vlasenko574f2f42008-02-27 18:41:59 +0000187 barrier();
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000188#endif
Denis Vlasenko15cb4a42007-10-11 10:06:26 +0000189 applet_name = applet;
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000190
191 /* Set locale for everybody except 'init' */
192 if (ENABLE_LOCALE_SUPPORT && getpid() != 1)
193 setlocale(LC_ALL, "");
194
Denis Vlasenko82d38da2007-10-10 14:38:47 +0000195#if ENABLE_FEATURE_INDIVIDUAL
196 /* Redundant for busybox (run_applet_and_exit covers that case)
197 * but needed for "individual applet" mode */
Denys Vlasenko9297dbc2010-07-05 21:37:12 +0200198 if (argv[1]
199 && !argv[2]
200 && strcmp(argv[1], "--help") == 0
201 && strncmp(applet, "busybox", 7) != 0
202 ) {
Denis Vlasenkobd28f6b2008-07-19 08:15:13 +0000203 /* Special case. POSIX says "test --help"
204 * should be no different from e.g. "test --foo". */
205 if (!ENABLE_TEST || strcmp(applet_name, "test") != 0)
206 bb_show_usage();
207 }
Denis Vlasenko82d38da2007-10-10 14:38:47 +0000208#endif
Denis Vlasenkoac7d0e32007-10-08 19:32:12 +0000209}
Denis Vlasenko724d1962007-10-10 14:41:07 +0000210
211/* The code below can well be in applets/applets.c, as it is used only
212 * for busybox binary, not "individual" binaries.
213 * However, keeping it here and linking it into libbusybox.so
214 * (together with remaining tiny applets/applets.o)
215 * makes it possible to avoid --whole-archive at link time.
216 * This makes (shared busybox) + libbusybox smaller.
217 * (--gc-sections would be even better....)
218 */
219
220const char *applet_name;
221#if !BB_MMU
222bool re_execed;
223#endif
224
Denis Vlasenko468aea22008-04-01 14:47:57 +0000225
Denis Vlasenko10f6fb12008-04-29 00:10:27 +0000226/* If not built as a single-applet executable... */
227#if !defined(SINGLE_APPLET_MAIN)
Denis Vlasenko468aea22008-04-01 14:47:57 +0000228
Denis Vlasenko5e34ff22009-04-21 11:09:40 +0000229IF_FEATURE_SUID(static uid_t ruid;) /* real uid */
Denis Vlasenko724d1962007-10-10 14:41:07 +0000230
231#if ENABLE_FEATURE_SUID_CONFIG
232
233/* applets[] is const, so we have to define this "override" structure */
234static struct BB_suid_config {
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000235 int m_applet;
Denis Vlasenko724d1962007-10-10 14:41:07 +0000236 uid_t m_uid;
237 gid_t m_gid;
238 mode_t m_mode;
239 struct BB_suid_config *m_next;
240} *suid_config;
241
242static bool suid_cfg_readable;
243
244/* check if u is member of group g */
245static int ingroup(uid_t u, gid_t g)
246{
247 struct group *grp = getgrgid(g);
248
249 if (grp) {
250 char **mem;
251
252 for (mem = grp->gr_mem; *mem; mem++) {
253 struct passwd *pwd = getpwnam(*mem);
254
255 if (pwd && (pwd->pw_uid == u))
256 return 1;
257 }
258 }
259 return 0;
260}
261
262/* This should probably be a libbb routine. In that case,
263 * I'd probably rename it to something like bb_trimmed_slice.
264 */
265static char *get_trimmed_slice(char *s, char *e)
266{
267 /* First, consider the value at e to be nul and back up until we
268 * reach a non-space char. Set the char after that (possibly at
269 * the original e) to nul. */
270 while (e-- > s) {
271 if (!isspace(*e)) {
272 break;
273 }
274 }
275 e[1] = '\0';
276
277 /* Next, advance past all leading space and return a ptr to the
278 * first non-space char; possibly the terminating nul. */
279 return skip_whitespace(s);
280}
281
282/* Don't depend on the tools to combine strings. */
283static const char config_file[] ALIGN1 = "/etc/busybox.conf";
284
285/* We don't supply a value for the nul, so an index adjustment is
286 * necessary below. Also, we use unsigned short here to save some
287 * space even though these are really mode_t values. */
288static const unsigned short mode_mask[] ALIGN2 = {
289 /* SST sst xxx --- */
290 S_ISUID, S_ISUID|S_IXUSR, S_IXUSR, 0, /* user */
291 S_ISGID, S_ISGID|S_IXGRP, S_IXGRP, 0, /* group */
292 0, S_IXOTH, S_IXOTH, 0 /* other */
293};
294
295#define parse_error(x) do { errmsg = x; goto pe_label; } while (0)
296
297static void parse_config_file(void)
298{
299 struct BB_suid_config *sct_head;
300 struct BB_suid_config *sct;
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000301 int applet_no;
Denis Vlasenko724d1962007-10-10 14:41:07 +0000302 FILE *f;
303 const char *errmsg;
304 char *s;
305 char *e;
306 int i;
307 unsigned lc;
308 smallint section;
309 char buffer[256];
310 struct stat st;
311
312 assert(!suid_config); /* Should be set to NULL by bss init. */
313
314 ruid = getuid();
315 if (ruid == 0) /* run by root - don't need to even read config file */
316 return;
317
318 if ((stat(config_file, &st) != 0) /* No config file? */
319 || !S_ISREG(st.st_mode) /* Not a regular file? */
320 || (st.st_uid != 0) /* Not owned by root? */
321 || (st.st_mode & (S_IWGRP | S_IWOTH)) /* Writable by non-root? */
Denis Vlasenko5415c852008-07-21 23:05:26 +0000322 || !(f = fopen_for_read(config_file)) /* Cannot open? */
Denis Vlasenko724d1962007-10-10 14:41:07 +0000323 ) {
324 return;
325 }
326
327 suid_cfg_readable = 1;
328 sct_head = NULL;
329 section = lc = 0;
330
331 while (1) {
332 s = buffer;
333
334 if (!fgets(s, sizeof(buffer), f)) { /* Are we done? */
Denis Vlasenkod02db892008-03-17 09:05:21 +0000335// why?
Denis Vlasenko724d1962007-10-10 14:41:07 +0000336 if (ferror(f)) { /* Make sure it wasn't a read error. */
337 parse_error("reading");
338 }
339 fclose(f);
340 suid_config = sct_head; /* Success, so set the pointer. */
341 return;
342 }
343
344 lc++; /* Got a (partial) line. */
345
346 /* If a line is too long for our buffer, we consider it an error.
347 * The following test does mistreat one corner case though.
348 * If the final line of the file does not end with a newline and
349 * yet exactly fills the buffer, it will be treated as too long
350 * even though there isn't really a problem. But it isn't really
351 * worth adding code to deal with such an unlikely situation, and
352 * we do err on the side of caution. Besides, the line would be
353 * too long if it did end with a newline. */
354 if (!strchr(s, '\n') && !feof(f)) {
355 parse_error("line too long");
356 }
357
358 /* Trim leading and trailing whitespace, ignoring comments, and
359 * check if the resulting string is empty. */
360 s = get_trimmed_slice(s, strchrnul(s, '#'));
361 if (!*s) {
362 continue;
363 }
364
365 /* Check for a section header. */
366
367 if (*s == '[') {
368 /* Unlike the old code, we ignore leading and trailing
369 * whitespace for the section name. We also require that
370 * there are no stray characters after the closing bracket. */
371 e = strchr(s, ']');
372 if (!e /* Missing right bracket? */
373 || e[1] /* Trailing characters? */
374 || !*(s = get_trimmed_slice(s+1, e)) /* Missing name? */
375 ) {
376 parse_error("section header");
377 }
378 /* Right now we only have one section so just check it.
379 * If more sections are added in the future, please don't
380 * resort to cascading ifs with multiple strcasecmp calls.
381 * That kind of bloated code is all too common. A loop
382 * and a string table would be a better choice unless the
383 * number of sections is very small. */
384 if (strcasecmp(s, "SUID") == 0) {
385 section = 1;
386 continue;
387 }
388 section = -1; /* Unknown section so set to skip. */
389 continue;
390 }
391
392 /* Process sections. */
393
394 if (section == 1) { /* SUID */
395 /* Since we trimmed leading and trailing space above, we're
396 * now looking for strings of the form
397 * <key>[::space::]*=[::space::]*<value>
398 * where both key and value could contain inner whitespace. */
399
400 /* First get the key (an applet name in our case). */
401 e = strchr(s, '=');
402 if (e) {
403 s = get_trimmed_slice(s, e);
404 }
405 if (!e || !*s) { /* Missing '=' or empty key. */
406 parse_error("keyword");
407 }
408
409 /* Ok, we have an applet name. Process the rhs if this
410 * applet is currently built in and ignore it otherwise.
411 * Note: this can hide config file bugs which only pop
412 * up when the busybox configuration is changed. */
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000413 applet_no = find_applet_by_name(s);
414 if (applet_no >= 0) {
Denis Vlasenko724d1962007-10-10 14:41:07 +0000415 /* Note: We currently don't check for duplicates!
416 * The last config line for each applet will be the
417 * one used since we insert at the head of the list.
418 * I suppose this could be considered a feature. */
419 sct = xmalloc(sizeof(struct BB_suid_config));
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000420 sct->m_applet = applet_no;
Denis Vlasenko724d1962007-10-10 14:41:07 +0000421 sct->m_mode = 0;
422 sct->m_next = sct_head;
423 sct_head = sct;
424
425 /* Get the specified mode. */
426
427 e = skip_whitespace(e+1);
428
429 for (i = 0; i < 3; i++) {
430 /* There are 4 chars + 1 nul for each of user/group/other. */
431 static const char mode_chars[] ALIGN1 = "Ssx-\0" "Ssx-\0" "Ttx-";
432
433 const char *q;
434 q = strchrnul(mode_chars + 5*i, *e++);
435 if (!*q) {
436 parse_error("mode");
437 }
438 /* Adjust by -i to account for nul. */
439 sct->m_mode |= mode_mask[(q - mode_chars) - i];
440 }
441
442 /* Now get the the user/group info. */
443
444 s = skip_whitespace(e);
445
446 /* Note: we require whitespace between the mode and the
447 * user/group info. */
448 if ((s == e) || !(e = strchr(s, '.'))) {
449 parse_error("<uid>.<gid>");
450 }
451 *e++ = '\0';
452
453 /* We can't use get_ug_id here since it would exit()
454 * if a uid or gid was not found. Oh well... */
455 sct->m_uid = bb_strtoul(s, NULL, 10);
456 if (errno) {
457 struct passwd *pwd = getpwnam(s);
458 if (!pwd) {
459 parse_error("user");
460 }
461 sct->m_uid = pwd->pw_uid;
462 }
463
464 sct->m_gid = bb_strtoul(e, NULL, 10);
465 if (errno) {
466 struct group *grp;
467 grp = getgrnam(e);
468 if (!grp) {
469 parse_error("group");
470 }
471 sct->m_gid = grp->gr_gid;
472 }
473 }
474 continue;
475 }
476
477 /* Unknown sections are ignored. */
478
479 /* Encountering configuration lines prior to seeing a
480 * section header is treated as an error. This is how
481 * the old code worked, but it may not be desirable.
482 * We may want to simply ignore such lines in case they
483 * are used in some future version of busybox. */
484 if (!section) {
485 parse_error("keyword outside section");
486 }
487
488 } /* while (1) */
489
490 pe_label:
491 fprintf(stderr, "Parse error in %s, line %d: %s\n",
492 config_file, lc, errmsg);
493
494 fclose(f);
495 /* Release any allocated memory before returning. */
496 while (sct_head) {
497 sct = sct_head->m_next;
498 free(sct_head);
499 sct_head = sct;
500 }
501}
502#else
503static inline void parse_config_file(void)
504{
Denis Vlasenko5e34ff22009-04-21 11:09:40 +0000505 IF_FEATURE_SUID(ruid = getuid();)
Denis Vlasenko724d1962007-10-10 14:41:07 +0000506}
507#endif /* FEATURE_SUID_CONFIG */
508
509
510#if ENABLE_FEATURE_SUID
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000511static void check_suid(int applet_no)
Denis Vlasenko724d1962007-10-10 14:41:07 +0000512{
513 gid_t rgid; /* real gid */
514
515 if (ruid == 0) /* set by parse_config_file() */
516 return; /* run by root - no need to check more */
517 rgid = getgid();
518
519#if ENABLE_FEATURE_SUID_CONFIG
520 if (suid_cfg_readable) {
521 uid_t uid;
522 struct BB_suid_config *sct;
523 mode_t m;
524
525 for (sct = suid_config; sct; sct = sct->m_next) {
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000526 if (sct->m_applet == applet_no)
Denis Vlasenko724d1962007-10-10 14:41:07 +0000527 goto found;
528 }
Denis Vlasenko15ca51e2007-10-29 19:25:45 +0000529 goto check_need_suid;
Denis Vlasenko724d1962007-10-10 14:41:07 +0000530 found:
531 m = sct->m_mode;
532 if (sct->m_uid == ruid)
533 /* same uid */
534 m >>= 6;
535 else if ((sct->m_gid == rgid) || ingroup(ruid, sct->m_gid))
536 /* same group / in group */
537 m >>= 3;
538
539 if (!(m & S_IXOTH)) /* is x bit not set ? */
540 bb_error_msg_and_die("you have no permission to run this applet!");
541
542 /* _both_ sgid and group_exec have to be set for setegid */
543 if ((sct->m_mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP))
544 rgid = sct->m_gid;
545 /* else (no setegid) we will set egid = rgid */
546
547 /* We set effective AND saved ids. If saved-id is not set
548 * like we do below, seteiud(0) can still later succeed! */
549 if (setresgid(-1, rgid, rgid))
550 bb_perror_msg_and_die("setresgid");
551
552 /* do we have to set effective uid? */
553 uid = ruid;
554 if (sct->m_mode & S_ISUID)
555 uid = sct->m_uid;
556 /* else (no seteuid) we will set euid = ruid */
557
558 if (setresuid(-1, uid, uid))
559 bb_perror_msg_and_die("setresuid");
560 return;
561 }
562#if !ENABLE_FEATURE_SUID_CONFIG_QUIET
563 {
564 static bool onetime = 0;
565
566 if (!onetime) {
567 onetime = 1;
568 fprintf(stderr, "Using fallback suid method\n");
569 }
570 }
571#endif
Denis Vlasenko15ca51e2007-10-29 19:25:45 +0000572 check_need_suid:
Denis Vlasenko724d1962007-10-10 14:41:07 +0000573#endif
Denys Vlasenko6d48d3e2009-07-30 12:57:19 +0200574 if (APPLET_SUID(applet_no) == _BB_SUID_REQUIRE) {
Denis Vlasenko724d1962007-10-10 14:41:07 +0000575 /* Real uid is not 0. If euid isn't 0 too, suid bit
576 * is most probably not set on our executable */
577 if (geteuid())
Denis Vlasenko15ca51e2007-10-29 19:25:45 +0000578 bb_error_msg_and_die("must be suid to work properly");
Denys Vlasenko6d48d3e2009-07-30 12:57:19 +0200579 } else if (APPLET_SUID(applet_no) == _BB_SUID_DROP) {
Denis Vlasenko724d1962007-10-10 14:41:07 +0000580 xsetgid(rgid); /* drop all privileges */
581 xsetuid(ruid);
582 }
583}
584#else
585#define check_suid(x) ((void)0)
586#endif /* FEATURE_SUID */
587
588
589#if ENABLE_FEATURE_INSTALLER
Denys Vlasenko5a7c7202010-04-20 21:02:57 -0400590static const char usr_bin [] ALIGN1 = "/usr/bin/";
591static const char usr_sbin[] ALIGN1 = "/usr/sbin/";
592static const char *const install_dir[] = {
593 &usr_bin [8], /* "/" */
594 &usr_bin [4], /* "/bin/" */
595 &usr_sbin[4], /* "/sbin/" */
596 usr_bin,
597 usr_sbin
598};
599
600
Denis Vlasenko724d1962007-10-10 14:41:07 +0000601/* create (sym)links for each applet */
Denys Vlasenko3b405432009-07-15 00:35:34 +0200602static void install_links(const char *busybox, int use_symbolic_links,
603 char *custom_install_dir)
Denis Vlasenko724d1962007-10-10 14:41:07 +0000604{
605 /* directory table
606 * this should be consistent w/ the enum,
607 * busybox.h::bb_install_loc_t, or else... */
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000608 int (*lf)(const char *, const char *);
Denis Vlasenko724d1962007-10-10 14:41:07 +0000609 char *fpc;
Denis Vlasenko6b06cb82008-05-15 21:30:45 +0000610 unsigned i;
Denis Vlasenko724d1962007-10-10 14:41:07 +0000611 int rc;
612
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000613 lf = link;
Denis Vlasenko724d1962007-10-10 14:41:07 +0000614 if (use_symbolic_links)
615 lf = symlink;
616
Denis Vlasenko745cd172007-11-29 03:31:20 +0000617 for (i = 0; i < ARRAY_SIZE(applet_main); i++) {
Denis Vlasenko724d1962007-10-10 14:41:07 +0000618 fpc = concat_path_file(
Denys Vlasenko3b405432009-07-15 00:35:34 +0200619 custom_install_dir ? custom_install_dir : install_dir[APPLET_INSTALL_LOC(i)],
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000620 APPLET_NAME(i));
Denis Vlasenko745cd172007-11-29 03:31:20 +0000621 // debug: bb_error_msg("%slinking %s to busybox",
622 // use_symbolic_links ? "sym" : "", fpc);
Denis Vlasenko724d1962007-10-10 14:41:07 +0000623 rc = lf(busybox, fpc);
624 if (rc != 0 && errno != EEXIST) {
625 bb_simple_perror_msg(fpc);
626 }
627 free(fpc);
628 }
629}
630#else
Denys Vlasenko5a7c7202010-04-20 21:02:57 -0400631# define install_links(x,y,z) ((void)0)
632#endif
Denis Vlasenko724d1962007-10-10 14:41:07 +0000633
634/* If we were called as "busybox..." */
635static int busybox_main(char **argv)
636{
637 if (!argv[1]) {
638 /* Called without arguments */
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000639 const char *a;
Denys Vlasenko0149f022009-05-19 18:01:42 +0200640 int col;
641 unsigned output_width;
Denis Vlasenko724d1962007-10-10 14:41:07 +0000642 help:
643 output_width = 80;
644 if (ENABLE_FEATURE_AUTOWIDTH) {
645 /* Obtain the terminal width */
646 get_terminal_width_height(0, &output_width, NULL);
647 }
Denis Vlasenko724d1962007-10-10 14:41:07 +0000648
Denis Vlasenko21278df2008-06-25 12:15:46 +0000649 dup2(1, 2);
Denys Vlasenko630dde12009-08-30 19:57:49 +0200650 full_write2_str(bb_banner); /* reuse const string */
651 full_write2_str(" multi-call binary.\n"); /* reuse */
652 full_write2_str(
Denys Vlasenko5a7c7202010-04-20 21:02:57 -0400653 "Copyright (C) 1998-2009 Erik Andersen, Rob Landley, Denys Vlasenko\n"
654 "and others. Licensed under GPLv2.\n"
655 "See source distribution for full notice.\n"
656 "\n"
657 "Usage: busybox [function] [arguments]...\n"
658 " or: function [arguments]...\n"
659 "\n"
660 "\tBusyBox is a multi-call binary that combines many common Unix\n"
661 "\tutilities into a single executable. Most people will create a\n"
662 "\tlink to busybox for each function they wish to use and BusyBox\n"
663 "\twill act like whatever it was invoked as.\n"
664 "\n"
665 "Currently defined functions:\n"
666 );
Denis Vlasenko724d1962007-10-10 14:41:07 +0000667 col = 0;
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000668 a = applet_names;
Denys Vlasenko0149f022009-05-19 18:01:42 +0200669 /* prevent last comma to be in the very last pos */
670 output_width--;
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000671 while (*a) {
Denys Vlasenko0149f022009-05-19 18:01:42 +0200672 int len2 = strlen(a) + 2;
673 if (col >= (int)output_width - len2) {
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000674 full_write2_str(",\n");
Denis Vlasenko724d1962007-10-10 14:41:07 +0000675 col = 0;
676 }
Denys Vlasenko0149f022009-05-19 18:01:42 +0200677 if (col == 0) {
678 col = 6;
679 full_write2_str("\t");
680 } else {
681 full_write2_str(", ");
682 }
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000683 full_write2_str(a);
Denys Vlasenko0149f022009-05-19 18:01:42 +0200684 col += len2;
685 a += len2 - 1;
Denis Vlasenko724d1962007-10-10 14:41:07 +0000686 }
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000687 full_write2_str("\n\n");
Denis Vlasenko724d1962007-10-10 14:41:07 +0000688 return 0;
689 }
690
Denys Vlasenko5a7c7202010-04-20 21:02:57 -0400691 if (strncmp(argv[1], "--list", 6) == 0) {
692 unsigned i = 0;
693 const char *a = applet_names;
694 dup2(1, 2);
695 while (*a) {
696#if ENABLE_FEATURE_INSTALLER
697 if (argv[1][6]) /* --list-path? */
698 full_write2_str(install_dir[APPLET_INSTALL_LOC(i)] + 1);
699#endif
700 full_write2_str(a);
701 full_write2_str("\n");
702 i++;
703 a += strlen(a) + 1;
704 }
705 return 0;
706 }
707
Denis Vlasenko724d1962007-10-10 14:41:07 +0000708 if (ENABLE_FEATURE_INSTALLER && strcmp(argv[1], "--install") == 0) {
Denys Vlasenko3b405432009-07-15 00:35:34 +0200709 int use_symbolic_links;
Denis Vlasenko724d1962007-10-10 14:41:07 +0000710 const char *busybox;
711 busybox = xmalloc_readlink(bb_busybox_exec_path);
712 if (!busybox)
713 busybox = bb_busybox_exec_path;
Denys Vlasenko0ad438b2009-07-15 02:14:15 +0200714 /* busybox --install [-s] [DIR]: */
715 /* -s: make symlinks */
716 /* DIR: directory to install links to */
Denys Vlasenko3b405432009-07-15 00:35:34 +0200717 use_symbolic_links = (argv[2] && strcmp(argv[2], "-s") == 0 && argv++);
718 install_links(busybox, use_symbolic_links, argv[2]);
Denis Vlasenko724d1962007-10-10 14:41:07 +0000719 return 0;
720 }
721
722 if (strcmp(argv[1], "--help") == 0) {
723 /* "busybox --help [<applet>]" */
724 if (!argv[2])
725 goto help;
726 /* convert to "<applet> --help" */
727 argv[0] = argv[2];
728 argv[2] = NULL;
729 } else {
730 /* "busybox <applet> arg1 arg2 ..." */
731 argv++;
732 }
733 /* We support "busybox /a/path/to/applet args..." too. Allows for
734 * "#!/bin/busybox"-style wrappers */
735 applet_name = bb_get_last_path_component_nostrip(argv[0]);
736 run_applet_and_exit(applet_name, argv);
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000737
738 /*bb_error_msg_and_die("applet not found"); - sucks in printf */
739 full_write2_str(applet_name);
740 full_write2_str(": applet not found\n");
741 xfunc_die();
Denis Vlasenko724d1962007-10-10 14:41:07 +0000742}
743
Denis Vlasenkodefc1ea2008-06-27 02:52:20 +0000744void FAST_FUNC run_applet_no_and_exit(int applet_no, char **argv)
Denis Vlasenko724d1962007-10-10 14:41:07 +0000745{
746 int argc = 1;
747
748 while (argv[argc])
749 argc++;
750
751 /* Reinit some shared global data */
Denis Vlasenko724d1962007-10-10 14:41:07 +0000752 xfunc_error_retval = EXIT_FAILURE;
753
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000754 applet_name = APPLET_NAME(applet_no);
Denis Vlasenkobd28f6b2008-07-19 08:15:13 +0000755 if (argc == 2 && strcmp(argv[1], "--help") == 0) {
756 /* Special case. POSIX says "test --help"
757 * should be no different from e.g. "test --foo". */
758//TODO: just compare applet_no with APPLET_NO_test
759 if (!ENABLE_TEST || strcmp(applet_name, "test") != 0)
760 bb_show_usage();
761 }
Denis Vlasenko724d1962007-10-10 14:41:07 +0000762 if (ENABLE_FEATURE_SUID)
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000763 check_suid(applet_no);
Denis Vlasenko745cd172007-11-29 03:31:20 +0000764 exit(applet_main[applet_no](argc, argv));
Denis Vlasenko724d1962007-10-10 14:41:07 +0000765}
766
Denis Vlasenkodefc1ea2008-06-27 02:52:20 +0000767void FAST_FUNC run_applet_and_exit(const char *name, char **argv)
Denis Vlasenko724d1962007-10-10 14:41:07 +0000768{
Denis Vlasenko1aa7e472007-11-28 06:49:03 +0000769 int applet = find_applet_by_name(name);
770 if (applet >= 0)
771 run_applet_no_and_exit(applet, argv);
Denis Vlasenko724d1962007-10-10 14:41:07 +0000772 if (!strncmp(name, "busybox", 7))
773 exit(busybox_main(argv));
774}
775
Denis Vlasenko10f6fb12008-04-29 00:10:27 +0000776#endif /* !defined(SINGLE_APPLET_MAIN) */
Denis Vlasenko468aea22008-04-01 14:47:57 +0000777
778
Denis Vlasenko724d1962007-10-10 14:41:07 +0000779
780#if ENABLE_BUILD_LIBBUSYBOX
Denis Vlasenko85c24712008-03-17 09:04:04 +0000781int lbb_main(char **argv)
Denis Vlasenko724d1962007-10-10 14:41:07 +0000782#else
Denis Vlasenkoa60f84e2008-07-05 09:18:54 +0000783int main(int argc UNUSED_PARAM, char **argv)
Denis Vlasenko724d1962007-10-10 14:41:07 +0000784#endif
785{
Denys Vlasenko1f7c1672009-09-06 02:12:28 +0200786 /* Tweak malloc for reduced memory consumption */
787#ifndef PAGE_SIZE
788# define PAGE_SIZE (4*1024) /* guess */
789#endif
790#ifdef M_TRIM_THRESHOLD
791 /* M_TRIM_THRESHOLD is the maximum amount of freed top-most memory
792 * to keep before releasing to the OS
793 * Default is way too big: 256k
794 */
795 mallopt(M_TRIM_THRESHOLD, 2 * PAGE_SIZE);
796#endif
797#ifdef M_MMAP_THRESHOLD
798 /* M_MMAP_THRESHOLD is the request size threshold for using mmap()
799 * Default is too big: 256k
800 */
801 mallopt(M_MMAP_THRESHOLD, 8 * PAGE_SIZE - 256);
802#endif
803
Denis Vlasenko10f6fb12008-04-29 00:10:27 +0000804#if defined(SINGLE_APPLET_MAIN)
Denis Vlasenko468aea22008-04-01 14:47:57 +0000805 /* Only one applet is selected by the user! */
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000806 /* applet_names in this case is just "applet\0\0" */
Denis Vlasenko5e34ff22009-04-21 11:09:40 +0000807 lbb_prepare(applet_names IF_FEATURE_INDIVIDUAL(, argv));
Denis Vlasenko468aea22008-04-01 14:47:57 +0000808 return SINGLE_APPLET_MAIN(argc, argv);
809#else
Denis Vlasenko5e34ff22009-04-21 11:09:40 +0000810 lbb_prepare("busybox" IF_FEATURE_INDIVIDUAL(, argv));
Denis Vlasenko724d1962007-10-10 14:41:07 +0000811
812#if !BB_MMU
813 /* NOMMU re-exec trick sets high-order bit in first byte of name */
814 if (argv[0][0] & 0x80) {
815 re_execed = 1;
816 argv[0][0] &= 0x7f;
817 }
818#endif
819 applet_name = argv[0];
820 if (applet_name[0] == '-')
821 applet_name++;
822 applet_name = bb_basename(applet_name);
823
824 parse_config_file(); /* ...maybe, if FEATURE_SUID_CONFIG */
825
826 run_applet_and_exit(applet_name, argv);
Denis Vlasenko79cedcb2008-04-08 21:13:28 +0000827
828 /*bb_error_msg_and_die("applet not found"); - sucks in printf */
829 full_write2_str(applet_name);
830 full_write2_str(": applet not found\n");
831 xfunc_die();
Denis Vlasenko468aea22008-04-01 14:47:57 +0000832#endif
Denis Vlasenko724d1962007-10-10 14:41:07 +0000833}