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- /* vi: set sw=4 ts=4: */
- /*
- * Utility routines.
- *
- * Copyright (C) tons of folks. Tracking down who wrote what
- * isn't something I'm going to worry about... If you wrote something
- * here, please feel free to acknowledge your work.
- *
- * Based in part on code from sash, Copyright (c) 1999 by David I. Bell
- * Permission has been granted to redistribute this code under GPL.
- *
- * Licensed under GPLv2 or later, see file LICENSE in this source tree.
- */
- /* We are trying to not use printf, this benefits the case when selected
- * applets are really simple. Example:
- *
- * $ ./busybox
- * ...
- * Currently defined functions:
- * basename, false, true
- *
- * $ size busybox
- * text data bss dec hex filename
- * 4473 52 72 4597 11f5 busybox
- *
- * FEATURE_INSTALLER or FEATURE_SUID will still link printf routines in. :(
- */
- #include "busybox.h"
- #if !(defined(__FreeBSD__) || defined(__OpenBSD__) || defined(__NetBSD__) \
- || defined(__APPLE__) \
- )
- # include <malloc.h> /* for mallopt */
- #endif
- /* Declare <applet>_main() */
- #define PROTOTYPES
- #include "applets.h"
- #undef PROTOTYPES
- /* Include generated applet names, pointers to <applet>_main, etc */
- #include "applet_tables.h"
- /* ...and if applet_tables generator says we have only one applet... */
- #ifdef SINGLE_APPLET_MAIN
- # undef ENABLE_FEATURE_INDIVIDUAL
- # define ENABLE_FEATURE_INDIVIDUAL 1
- # undef IF_FEATURE_INDIVIDUAL
- # define IF_FEATURE_INDIVIDUAL(...) __VA_ARGS__
- #endif
- #include "usage_compressed.h"
- /* "Do not compress usage text if uncompressed text is small
- * and we don't include bunzip2 code for other reasons"
- *
- * Useful for mass one-applet rebuild (bunzip2 code is ~2.7k).
- *
- * Unlike BUNZIP2, if FEATURE_SEAMLESS_BZ2 is on, bunzip2 code is built but
- * still may be unused if none of the selected applets calls open_zipped()
- * or its friends; we test for (FEATURE_SEAMLESS_BZ2 && <APPLET>) instead.
- * For example, only if TAR and FEATURE_SEAMLESS_BZ2 are both selected,
- * then bunzip2 code will be linked in anyway, and disabling help compression
- * would be not optimal:
- */
- #if UNPACKED_USAGE_LENGTH < 4*1024 \
- && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_TAR) \
- && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_MODPROBE) \
- && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_INSMOD) \
- && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_DEPMOD) \
- && !(ENABLE_FEATURE_SEAMLESS_BZ2 && ENABLE_MAN) \
- && !ENABLE_BUNZIP2 \
- && !ENABLE_BZCAT
- # undef ENABLE_FEATURE_COMPRESS_USAGE
- # define ENABLE_FEATURE_COMPRESS_USAGE 0
- #endif
- unsigned FAST_FUNC string_array_len(char **argv)
- {
- char **start = argv;
- while (*argv)
- argv++;
- return argv - start;
- }
- #if ENABLE_SHOW_USAGE && !ENABLE_FEATURE_COMPRESS_USAGE
- static const char usage_messages[] ALIGN1 = UNPACKED_USAGE;
- #else
- # define usage_messages 0
- #endif
- #if ENABLE_FEATURE_COMPRESS_USAGE
- static const char packed_usage[] ALIGN1 = { PACKED_USAGE };
- # include "bb_archive.h"
- static const char *unpack_usage_messages(void)
- {
- char *outbuf = NULL;
- bunzip_data *bd;
- int i;
- jmp_buf jmpbuf;
- /* Setup for I/O error handling via longjmp */
- i = setjmp(jmpbuf);
- if (i == 0) {
- i = start_bunzip(&jmpbuf,
- &bd,
- /* src_fd: */ -1,
- /* inbuf: */ packed_usage,
- /* len: */ sizeof(packed_usage)
- );
- }
- /* read_bunzip can longjmp and end up here with i != 0
- * on read data errors! Not trivial */
- if (i == 0) {
- /* Cannot use xmalloc: will leak bd in NOFORK case! */
- outbuf = malloc_or_warn(sizeof(UNPACKED_USAGE));
- if (outbuf)
- read_bunzip(bd, outbuf, sizeof(UNPACKED_USAGE));
- }
- dealloc_bunzip(bd);
- return outbuf;
- }
- # define dealloc_usage_messages(s) free(s)
- #else
- # define unpack_usage_messages() usage_messages
- # define dealloc_usage_messages(s) ((void)(s))
- #endif /* FEATURE_COMPRESS_USAGE */
- void FAST_FUNC bb_show_usage(void)
- {
- if (ENABLE_SHOW_USAGE) {
- #ifdef SINGLE_APPLET_STR
- /* Imagine that this applet is "true". Dont suck in printf! */
- const char *usage_string = unpack_usage_messages();
- if (*usage_string == '\b') {
- full_write2_str("No help available.\n\n");
- } else {
- full_write2_str("Usage: "SINGLE_APPLET_STR" ");
- full_write2_str(usage_string);
- full_write2_str("\n\n");
- }
- if (ENABLE_FEATURE_CLEAN_UP)
- dealloc_usage_messages((char*)usage_string);
- #else
- const char *p;
- const char *usage_string = p = unpack_usage_messages();
- int ap = find_applet_by_name(applet_name);
- if (ap < 0) /* never happens, paranoia */
- xfunc_die();
- while (ap) {
- while (*p++) continue;
- ap--;
- }
- full_write2_str(bb_banner);
- full_write2_str(" multi-call binary.\n");
- if (*p == '\b')
- full_write2_str("\nNo help available.\n\n");
- else {
- full_write2_str("\nUsage: ");
- full_write2_str(applet_name);
- full_write2_str(" ");
- full_write2_str(p);
- full_write2_str("\n");
- }
- if (ENABLE_FEATURE_CLEAN_UP)
- dealloc_usage_messages((char*)usage_string);
- #endif
- }
- xfunc_die();
- }
- int FAST_FUNC find_applet_by_name(const char *name)
- {
- unsigned i, max;
- int j;
- const char *p;
- /* The commented-out word-at-a-time code is ~40% faster, but +160 bytes.
- * "Faster" here saves ~0.5 microsecond of real time - not worth it.
- */
- #if 0 /*BB_UNALIGNED_MEMACCESS_OK && BB_LITTLE_ENDIAN*/
- uint32_t n32;
- /* Handle all names < 2 chars long early */
- if (name[0] == '\0')
- return -1; /* "" is not a valid applet name */
- if (name[1] == '\0') {
- if (!ENABLE_TEST)
- return -1; /* 1-char name is not valid */
- if (name[0] != ']')
- return -1; /* 1-char name which isn't "[" is not valid */
- /* applet "[" is always applet #0: */
- return 0;
- }
- #endif
- p = applet_names;
- i = 0;
- #if KNOWN_APPNAME_OFFSETS <= 0
- max = NUM_APPLETS;
- #else
- max = NUM_APPLETS * KNOWN_APPNAME_OFFSETS;
- for (j = ARRAY_SIZE(applet_nameofs)-1; j >= 0; j--) {
- const char *pp = applet_names + applet_nameofs[j];
- if (strcmp(name, pp) >= 0) {
- //bb_error_msg("name:'%s' >= pp:'%s'", name, pp);
- p = pp;
- i = max - NUM_APPLETS;
- break;
- }
- max -= NUM_APPLETS;
- }
- max /= (unsigned)KNOWN_APPNAME_OFFSETS;
- i /= (unsigned)KNOWN_APPNAME_OFFSETS;
- //bb_error_msg("name:'%s' starting from:'%s' i:%u max:%u", name, p, i, max);
- #endif
- /* Open-coded linear search without strcmp/strlen calls for speed */
- #if 0 /*BB_UNALIGNED_MEMACCESS_OK && BB_LITTLE_ENDIAN*/
- /* skip "[\0" name, it's surely not it */
- if (ENABLE_TEST && LONE_CHAR(p, '['))
- i++, p += 2;
- /* All remaining applet names in p[] are at least 2 chars long */
- /* name[] is also at least 2 chars long */
- n32 = (name[0] << 0) | (name[1] << 8) | (name[2] << 16);
- while (i < max) {
- uint32_t p32;
- char ch;
- /* Quickly check match of the first 3 bytes */
- move_from_unaligned32(p32, p);
- p += 3;
- if ((p32 & 0x00ffffff) != n32) {
- /* Most likely case: 3 first bytes do not match */
- i++;
- if ((p32 & 0x00ff0000) == '\0')
- continue; // p[2] was NUL
- p++;
- if ((p32 & 0xff000000) == '\0')
- continue; // p[3] was NUL
- /* p[0..3] aren't matching and none is NUL, check the rest */
- while (*p++ != '\0')
- continue;
- continue;
- }
- /* Unlikely branch: first 3 bytes ([0..2]) match */
- if ((p32 & 0x00ff0000) == '\0') {
- /* name is 2-byte long, it is full match */
- //bb_error_msg("found:'%s' i:%u", name, i);
- return i;
- }
- /* Check remaining bytes [3..NUL] */
- ch = (p32 >> 24);
- j = 3;
- while (ch == name[j]) {
- if (ch == '\0') {
- //bb_error_msg("found:'%s' i:%u", name, i);
- return i;
- }
- ch = *++p;
- j++;
- }
- /* Not a match. Skip it, including NUL */
- while (ch != '\0')
- ch = *++p;
- p++;
- i++;
- }
- return -1;
- #else
- while (i < max) {
- char ch;
- j = 0;
- /* Do we see "name\0" in applet_names[p] position? */
- while ((ch = *p) == name[j]) {
- if (ch == '\0') {
- //bb_error_msg("found:'%s' i:%u", name, i);
- return i; /* yes */
- }
- p++;
- j++;
- }
- /* No.
- * p => 1st non-matching char in applet_names[],
- * skip to and including NUL.
- */
- while (ch != '\0')
- ch = *++p;
- p++;
- i++;
- }
- return -1;
- #endif
- }
- void lbb_prepare(const char *applet
- IF_FEATURE_INDIVIDUAL(, char **argv))
- MAIN_EXTERNALLY_VISIBLE;
- void lbb_prepare(const char *applet
- IF_FEATURE_INDIVIDUAL(, char **argv))
- {
- #ifdef __GLIBC__
- (*(int **)&bb_errno) = __errno_location();
- barrier();
- #endif
- applet_name = applet;
- if (ENABLE_LOCALE_SUPPORT)
- setlocale(LC_ALL, "");
- #if ENABLE_FEATURE_INDIVIDUAL
- /* Redundant for busybox (run_applet_and_exit covers that case)
- * but needed for "individual applet" mode */
- if (argv[1]
- && !argv[2]
- && strcmp(argv[1], "--help") == 0
- && !is_prefixed_with(applet, "busybox")
- ) {
- /* Special case. POSIX says "test --help"
- * should be no different from e.g. "test --foo". */
- if (!ENABLE_TEST || strcmp(applet_name, "test") != 0)
- bb_show_usage();
- }
- #endif
- }
- /* The code below can well be in applets/applets.c, as it is used only
- * for busybox binary, not "individual" binaries.
- * However, keeping it here and linking it into libbusybox.so
- * (together with remaining tiny applets/applets.o)
- * makes it possible to avoid --whole-archive at link time.
- * This makes (shared busybox) + libbusybox smaller.
- * (--gc-sections would be even better....)
- */
- const char *applet_name;
- #if !BB_MMU
- bool re_execed;
- #endif
- /* If not built as a single-applet executable... */
- #if !defined(SINGLE_APPLET_MAIN)
- IF_FEATURE_SUID(static uid_t ruid;) /* real uid */
- # if ENABLE_FEATURE_SUID_CONFIG
- static struct suid_config_t {
- /* next ptr must be first: this struct needs to be llist-compatible */
- struct suid_config_t *m_next;
- struct bb_uidgid_t m_ugid;
- int m_applet;
- mode_t m_mode;
- } *suid_config;
- static bool suid_cfg_readable;
- /* libbb candidate */
- static char *get_trimmed_slice(char *s, char *e)
- {
- /* First, consider the value at e to be nul and back up until we
- * reach a non-space char. Set the char after that (possibly at
- * the original e) to nul. */
- while (e-- > s) {
- if (!isspace(*e)) {
- break;
- }
- }
- e[1] = '\0';
- /* Next, advance past all leading space and return a ptr to the
- * first non-space char; possibly the terminating nul. */
- return skip_whitespace(s);
- }
- static void parse_config_file(void)
- {
- /* Don't depend on the tools to combine strings. */
- static const char config_file[] ALIGN1 = "/etc/busybox.conf";
- struct suid_config_t *sct_head;
- int applet_no;
- FILE *f;
- const char *errmsg;
- unsigned lc;
- smallint section;
- struct stat st;
- ruid = getuid();
- if (ruid == 0) /* run by root - don't need to even read config file */
- return;
- if ((stat(config_file, &st) != 0) /* No config file? */
- || !S_ISREG(st.st_mode) /* Not a regular file? */
- || (st.st_uid != 0) /* Not owned by root? */
- || (st.st_mode & (S_IWGRP | S_IWOTH)) /* Writable by non-root? */
- || !(f = fopen_for_read(config_file)) /* Cannot open? */
- ) {
- return;
- }
- suid_cfg_readable = 1;
- sct_head = NULL;
- section = lc = 0;
- while (1) {
- char buffer[256];
- char *s;
- if (!fgets(buffer, sizeof(buffer), f)) { /* Are we done? */
- // Looks like bloat
- //if (ferror(f)) { /* Make sure it wasn't a read error. */
- // errmsg = "reading";
- // goto pe_label;
- //}
- fclose(f);
- suid_config = sct_head; /* Success, so set the pointer. */
- return;
- }
- s = buffer;
- lc++; /* Got a (partial) line. */
- /* If a line is too long for our buffer, we consider it an error.
- * The following test does mistreat one corner case though.
- * If the final line of the file does not end with a newline and
- * yet exactly fills the buffer, it will be treated as too long
- * even though there isn't really a problem. But it isn't really
- * worth adding code to deal with such an unlikely situation, and
- * we do err on the side of caution. Besides, the line would be
- * too long if it did end with a newline. */
- if (!strchr(s, '\n') && !feof(f)) {
- errmsg = "line too long";
- goto pe_label;
- }
- /* Trim leading and trailing whitespace, ignoring comments, and
- * check if the resulting string is empty. */
- s = get_trimmed_slice(s, strchrnul(s, '#'));
- if (!*s) {
- continue;
- }
- /* Check for a section header. */
- if (*s == '[') {
- /* Unlike the old code, we ignore leading and trailing
- * whitespace for the section name. We also require that
- * there are no stray characters after the closing bracket. */
- char *e = strchr(s, ']');
- if (!e /* Missing right bracket? */
- || e[1] /* Trailing characters? */
- || !*(s = get_trimmed_slice(s+1, e)) /* Missing name? */
- ) {
- errmsg = "section header";
- goto pe_label;
- }
- /* Right now we only have one section so just check it.
- * If more sections are added in the future, please don't
- * resort to cascading ifs with multiple strcasecmp calls.
- * That kind of bloated code is all too common. A loop
- * and a string table would be a better choice unless the
- * number of sections is very small. */
- if (strcasecmp(s, "SUID") == 0) {
- section = 1;
- continue;
- }
- section = -1; /* Unknown section so set to skip. */
- continue;
- }
- /* Process sections. */
- if (section == 1) { /* SUID */
- /* Since we trimmed leading and trailing space above, we're
- * now looking for strings of the form
- * <key>[::space::]*=[::space::]*<value>
- * where both key and value could contain inner whitespace. */
- /* First get the key (an applet name in our case). */
- char *e = strchr(s, '=');
- if (e) {
- s = get_trimmed_slice(s, e);
- }
- if (!e || !*s) { /* Missing '=' or empty key. */
- errmsg = "keyword";
- goto pe_label;
- }
- /* Ok, we have an applet name. Process the rhs if this
- * applet is currently built in and ignore it otherwise.
- * Note: this can hide config file bugs which only pop
- * up when the busybox configuration is changed. */
- applet_no = find_applet_by_name(s);
- if (applet_no >= 0) {
- unsigned i;
- struct suid_config_t *sct;
- /* Note: We currently don't check for duplicates!
- * The last config line for each applet will be the
- * one used since we insert at the head of the list.
- * I suppose this could be considered a feature. */
- sct = xzalloc(sizeof(*sct));
- sct->m_applet = applet_no;
- /*sct->m_mode = 0;*/
- sct->m_next = sct_head;
- sct_head = sct;
- /* Get the specified mode. */
- e = skip_whitespace(e+1);
- for (i = 0; i < 3; i++) {
- /* There are 4 chars for each of user/group/other.
- * "x-xx" instead of "x-" are to make
- * "idx > 3" check catch invalid chars.
- */
- static const char mode_chars[] ALIGN1 = "Ssx-" "Ssx-" "x-xx";
- static const unsigned short mode_mask[] ALIGN2 = {
- S_ISUID, S_ISUID|S_IXUSR, S_IXUSR, 0, /* Ssx- */
- S_ISGID, S_ISGID|S_IXGRP, S_IXGRP, 0, /* Ssx- */
- S_IXOTH, 0 /* x- */
- };
- const char *q = strchrnul(mode_chars + 4*i, *e);
- unsigned idx = q - (mode_chars + 4*i);
- if (idx > 3) {
- errmsg = "mode";
- goto pe_label;
- }
- sct->m_mode |= mode_mask[q - mode_chars];
- e++;
- }
- /* Now get the user/group info. */
- s = skip_whitespace(e);
- /* Default is 0.0, else parse USER.GROUP: */
- if (*s) {
- /* We require whitespace between mode and USER.GROUP */
- if ((s == e) || !(e = strchr(s, '.'))) {
- errmsg = "uid.gid";
- goto pe_label;
- }
- *e = ':'; /* get_uidgid needs USER:GROUP syntax */
- if (get_uidgid(&sct->m_ugid, s) == 0) {
- errmsg = "unknown user/group";
- goto pe_label;
- }
- }
- }
- continue;
- }
- /* Unknown sections are ignored. */
- /* Encountering configuration lines prior to seeing a
- * section header is treated as an error. This is how
- * the old code worked, but it may not be desirable.
- * We may want to simply ignore such lines in case they
- * are used in some future version of busybox. */
- if (!section) {
- errmsg = "keyword outside section";
- goto pe_label;
- }
- } /* while (1) */
- pe_label:
- fclose(f);
- bb_error_msg("parse error in %s, line %u: %s", config_file, lc, errmsg);
- /* Release any allocated memory before returning. */
- llist_free((llist_t*)sct_head, NULL);
- }
- # else
- static inline void parse_config_file(void)
- {
- IF_FEATURE_SUID(ruid = getuid();)
- }
- # endif /* FEATURE_SUID_CONFIG */
- # if ENABLE_FEATURE_SUID && NUM_APPLETS > 0
- # if ENABLE_FEATURE_SUID_CONFIG
- /* check if u is member of group g */
- static int ingroup(uid_t u, gid_t g)
- {
- struct group *grp = getgrgid(g);
- if (grp) {
- char **mem;
- for (mem = grp->gr_mem; *mem; mem++) {
- struct passwd *pwd = getpwnam(*mem);
- if (pwd && (pwd->pw_uid == u))
- return 1;
- }
- }
- return 0;
- }
- # endif
- static void check_suid(int applet_no)
- {
- gid_t rgid; /* real gid */
- if (ruid == 0) /* set by parse_config_file() */
- return; /* run by root - no need to check more */
- rgid = getgid();
- # if ENABLE_FEATURE_SUID_CONFIG
- if (suid_cfg_readable) {
- uid_t uid;
- struct suid_config_t *sct;
- mode_t m;
- for (sct = suid_config; sct; sct = sct->m_next) {
- if (sct->m_applet == applet_no)
- goto found;
- }
- goto check_need_suid;
- found:
- /* Is this user allowed to run this applet? */
- m = sct->m_mode;
- if (sct->m_ugid.uid == ruid)
- /* same uid */
- m >>= 6;
- else if ((sct->m_ugid.gid == rgid) || ingroup(ruid, sct->m_ugid.gid))
- /* same group / in group */
- m >>= 3;
- if (!(m & S_IXOTH)) /* is x bit not set? */
- bb_error_msg_and_die("you have no permission to run this applet");
- /* We set effective AND saved ids. If saved-id is not set
- * like we do below, seteuid(0) can still later succeed! */
- /* Are we directed to change gid
- * (APPLET = *s* USER.GROUP or APPLET = *S* USER.GROUP)?
- */
- if (sct->m_mode & S_ISGID)
- rgid = sct->m_ugid.gid;
- /* else: we will set egid = rgid, thus dropping sgid effect */
- if (setresgid(-1, rgid, rgid))
- bb_perror_msg_and_die("setresgid");
- /* Are we directed to change uid
- * (APPLET = s** USER.GROUP or APPLET = S** USER.GROUP)?
- */
- uid = ruid;
- if (sct->m_mode & S_ISUID)
- uid = sct->m_ugid.uid;
- /* else: we will set euid = ruid, thus dropping suid effect */
- if (setresuid(-1, uid, uid))
- bb_perror_msg_and_die("setresuid");
- goto ret;
- }
- # if !ENABLE_FEATURE_SUID_CONFIG_QUIET
- {
- static bool onetime = 0;
- if (!onetime) {
- onetime = 1;
- bb_error_msg("using fallback suid method");
- }
- }
- # endif
- check_need_suid:
- # endif
- if (APPLET_SUID(applet_no) == BB_SUID_REQUIRE) {
- /* Real uid is not 0. If euid isn't 0 too, suid bit
- * is most probably not set on our executable */
- if (geteuid())
- bb_error_msg_and_die("must be suid to work properly");
- } else if (APPLET_SUID(applet_no) == BB_SUID_DROP) {
- /*
- * Drop all privileges.
- *
- * Don't check for errors: in normal use, they are impossible,
- * and in special cases, exiting is harmful. Example:
- * 'unshare --user' when user's shell is also from busybox.
- *
- * 'unshare --user' creates a new user namespace without any
- * uid mappings. Thus, busybox binary is setuid nobody:nogroup
- * within the namespace, as that is the only user. However,
- * since no uids are mapped, calls to setgid/setuid
- * fail (even though they would do nothing).
- */
- setgid(rgid);
- setuid(ruid);
- }
- # if ENABLE_FEATURE_SUID_CONFIG
- ret: ;
- llist_free((llist_t*)suid_config, NULL);
- # endif
- }
- # else
- # define check_suid(x) ((void)0)
- # endif /* FEATURE_SUID */
- # if ENABLE_FEATURE_INSTALLER
- static const char usr_bin [] ALIGN1 = "/usr/bin/";
- static const char usr_sbin[] ALIGN1 = "/usr/sbin/";
- static const char *const install_dir[] = {
- &usr_bin [8], /* "/" */
- &usr_bin [4], /* "/bin/" */
- &usr_sbin[4] /* "/sbin/" */
- # if !ENABLE_INSTALL_NO_USR
- ,usr_bin
- ,usr_sbin
- # endif
- };
- /* create (sym)links for each applet */
- static void install_links(const char *busybox, int use_symbolic_links,
- char *custom_install_dir)
- {
- /* directory table
- * this should be consistent w/ the enum,
- * busybox.h::bb_install_loc_t, or else... */
- int (*lf)(const char *, const char *);
- char *fpc;
- const char *appname = applet_names;
- unsigned i;
- int rc;
- lf = link;
- if (use_symbolic_links)
- lf = symlink;
- for (i = 0; i < ARRAY_SIZE(applet_main); i++) {
- fpc = concat_path_file(
- custom_install_dir ? custom_install_dir : install_dir[APPLET_INSTALL_LOC(i)],
- appname);
- // debug: bb_error_msg("%slinking %s to busybox",
- // use_symbolic_links ? "sym" : "", fpc);
- rc = lf(busybox, fpc);
- if (rc != 0 && errno != EEXIST) {
- bb_simple_perror_msg(fpc);
- }
- free(fpc);
- while (*appname++ != '\0')
- continue;
- }
- }
- # elif ENABLE_BUSYBOX
- static void install_links(const char *busybox UNUSED_PARAM,
- int use_symbolic_links UNUSED_PARAM,
- char *custom_install_dir UNUSED_PARAM)
- {
- }
- # endif
- static void run_applet_and_exit(const char *name, char **argv) NORETURN;
- # if ENABLE_BUSYBOX
- # if ENABLE_FEATURE_SH_STANDALONE && ENABLE_FEATURE_TAB_COMPLETION
- /*
- * Insert "busybox" into applet table as well.
- * This makes standalone shell tab-complete this name too.
- * (Otherwise having "busybox" in applet table is not necessary,
- * there is other code which routes "busyboxANY_SUFFIX" name
- * to busybox_main()).
- */
- //usage:#define busybox_trivial_usage NOUSAGE_STR
- //usage:#define busybox_full_usage ""
- //applet:IF_BUSYBOX(IF_FEATURE_SH_STANDALONE(IF_FEATURE_TAB_COMPLETION(APPLET(busybox, BB_DIR_BIN, BB_SUID_MAYBE))))
- int busybox_main(int argc, char *argv[]) MAIN_EXTERNALLY_VISIBLE;
- # else
- # define busybox_main(argc,argv) busybox_main(argv)
- static
- # endif
- int busybox_main(int argc UNUSED_PARAM, char **argv)
- {
- if (!argv[1]) {
- /* Called without arguments */
- const char *a;
- int col;
- unsigned output_width;
- help:
- output_width = get_terminal_width(2);
- dup2(1, 2);
- full_write2_str(bb_banner); /* reuse const string */
- full_write2_str(" multi-call binary.\n"); /* reuse */
- full_write2_str(
- "BusyBox is copyrighted by many authors between 1998-2015.\n"
- "Licensed under GPLv2. See source distribution for detailed\n"
- "copyright notices.\n"
- "\n"
- "Usage: busybox [function [arguments]...]\n"
- " or: busybox --list"IF_FEATURE_INSTALLER("[-full]")"\n"
- IF_FEATURE_INSTALLER(
- " or: busybox --install [-s] [DIR]\n"
- )
- " or: function [arguments]...\n"
- "\n"
- IF_NOT_FEATURE_SH_STANDALONE(
- "\tBusyBox is a multi-call binary that combines many common Unix\n"
- "\tutilities into a single executable. Most people will create a\n"
- "\tlink to busybox for each function they wish to use and BusyBox\n"
- "\twill act like whatever it was invoked as.\n"
- )
- IF_FEATURE_SH_STANDALONE(
- "\tBusyBox is a multi-call binary that combines many common Unix\n"
- "\tutilities into a single executable. The shell in this build\n"
- "\tis configured to run built-in utilities without $PATH search.\n"
- "\tYou don't need to install a link to busybox for each utility.\n"
- "\tTo run external program, use full path (/sbin/ip instead of ip).\n"
- )
- "\n"
- "Currently defined functions:\n"
- );
- col = 0;
- a = applet_names;
- /* prevent last comma to be in the very last pos */
- output_width--;
- while (*a) {
- int len2 = strlen(a) + 2;
- if (col >= (int)output_width - len2) {
- full_write2_str(",\n");
- col = 0;
- }
- if (col == 0) {
- col = 6;
- full_write2_str("\t");
- } else {
- full_write2_str(", ");
- }
- full_write2_str(a);
- col += len2;
- a += len2 - 1;
- }
- full_write2_str("\n");
- return 0;
- }
- if (is_prefixed_with(argv[1], "--list")) {
- unsigned i = 0;
- const char *a = applet_names;
- dup2(1, 2);
- while (*a) {
- # if ENABLE_FEATURE_INSTALLER
- if (argv[1][6]) /* --list-full? */
- full_write2_str(install_dir[APPLET_INSTALL_LOC(i)] + 1);
- # endif
- full_write2_str(a);
- full_write2_str("\n");
- i++;
- while (*a++ != '\0')
- continue;
- }
- return 0;
- }
- if (ENABLE_FEATURE_INSTALLER && strcmp(argv[1], "--install") == 0) {
- int use_symbolic_links;
- const char *busybox;
- busybox = xmalloc_readlink(bb_busybox_exec_path);
- if (!busybox) {
- /* bb_busybox_exec_path is usually "/proc/self/exe".
- * In chroot, readlink("/proc/self/exe") usually fails.
- * In such case, better use argv[0] as symlink target
- * if it is a full path name.
- */
- if (argv[0][0] != '/')
- bb_error_msg_and_die("'%s' is not an absolute path", argv[0]);
- busybox = argv[0];
- }
- /* busybox --install [-s] [DIR]:
- * -s: make symlinks
- * DIR: directory to install links to
- */
- use_symbolic_links = (argv[2] && strcmp(argv[2], "-s") == 0 && ++argv);
- install_links(busybox, use_symbolic_links, argv[2]);
- return 0;
- }
- if (strcmp(argv[1], "--help") == 0) {
- /* "busybox --help [<applet>]" */
- if (!argv[2])
- goto help;
- /* convert to "<applet> --help" */
- argv[0] = argv[2];
- argv[2] = NULL;
- } else {
- /* "busybox <applet> arg1 arg2 ..." */
- argv++;
- }
- /* We support "busybox /a/path/to/applet args..." too. Allows for
- * "#!/bin/busybox"-style wrappers */
- applet_name = bb_get_last_path_component_nostrip(argv[0]);
- run_applet_and_exit(applet_name, argv);
- }
- # endif
- # if NUM_APPLETS > 0
- void FAST_FUNC run_applet_no_and_exit(int applet_no, const char *name, char **argv)
- {
- int argc = string_array_len(argv);
- /*
- * We do not use argv[0]: do not want to repeat massaging of
- * "-/sbin/halt" -> "halt", for example.
- */
- applet_name = name;
- /* Special case. POSIX says "test --help"
- * should be no different from e.g. "test --foo".
- * Thus for "test", we skip --help check.
- * "true" and "false" are also special.
- */
- if (1
- # if defined APPLET_NO_test
- && applet_no != APPLET_NO_test
- # endif
- # if defined APPLET_NO_true
- && applet_no != APPLET_NO_true
- # endif
- # if defined APPLET_NO_false
- && applet_no != APPLET_NO_false
- # endif
- ) {
- if (argc == 2 && strcmp(argv[1], "--help") == 0) {
- /* Make "foo --help" exit with 0: */
- xfunc_error_retval = 0;
- bb_show_usage();
- }
- }
- if (ENABLE_FEATURE_SUID)
- check_suid(applet_no);
- xfunc_error_retval = applet_main[applet_no](argc, argv);
- /* Note: applet_main() may also not return (die on a xfunc or such) */
- xfunc_die();
- }
- # endif /* NUM_APPLETS > 0 */
- # if ENABLE_BUSYBOX || NUM_APPLETS > 0
- static NORETURN void run_applet_and_exit(const char *name, char **argv)
- {
- # if ENABLE_BUSYBOX
- if (is_prefixed_with(name, "busybox"))
- exit(busybox_main(/*unused:*/ 0, argv));
- # endif
- # if NUM_APPLETS > 0
- /* find_applet_by_name() search is more expensive, so goes second */
- {
- int applet = find_applet_by_name(name);
- if (applet >= 0)
- run_applet_no_and_exit(applet, name, argv);
- }
- # endif
- /*bb_error_msg_and_die("applet not found"); - links in printf */
- full_write2_str(applet_name);
- full_write2_str(": applet not found\n");
- /* POSIX: "If a command is not found, the exit status shall be 127" */
- exit(127);
- }
- # endif
- #endif /* !defined(SINGLE_APPLET_MAIN) */
- #if ENABLE_BUILD_LIBBUSYBOX
- int lbb_main(char **argv)
- #else
- int main(int argc UNUSED_PARAM, char **argv)
- #endif
- {
- #if 0
- /* TODO: find a use for a block of memory between end of .bss
- * and end of page. For example, I'm getting "_end:0x812e698 2408 bytes"
- * - more than 2k of wasted memory (in this particular build)
- * *per each running process*!
- * (If your linker does not generate "_end" name, weak attribute
- * makes &_end == NULL, end_len == 0 here.)
- */
- extern char _end[] __attribute__((weak));
- unsigned end_len = (-(int)_end) & 0xfff;
- printf("_end:%p %u bytes\n", &_end, end_len);
- #endif
- /* Tweak malloc for reduced memory consumption */
- #ifdef M_TRIM_THRESHOLD
- /* M_TRIM_THRESHOLD is the maximum amount of freed top-most memory
- * to keep before releasing to the OS
- * Default is way too big: 256k
- */
- mallopt(M_TRIM_THRESHOLD, 8 * 1024);
- #endif
- #ifdef M_MMAP_THRESHOLD
- /* M_MMAP_THRESHOLD is the request size threshold for using mmap()
- * Default is too big: 256k
- */
- mallopt(M_MMAP_THRESHOLD, 32 * 1024 - 256);
- #endif
- #if 0 /*def M_TOP_PAD*/
- /* When the program break is increased, then M_TOP_PAD bytes are added
- * to the sbrk(2) request. When the heap is trimmed because of free(3),
- * this much free space is preserved at the top of the heap.
- * glibc default seems to be way too big: 128k, but need to verify.
- */
- mallopt(M_TOP_PAD, 8 * 1024);
- #endif
- #if !BB_MMU
- /* NOMMU re-exec trick sets high-order bit in first byte of name */
- if (argv[0][0] & 0x80) {
- re_execed = 1;
- argv[0][0] &= 0x7f;
- }
- #endif
- #if defined(SINGLE_APPLET_MAIN)
- /* Only one applet is selected in .config */
- if (argv[1] && is_prefixed_with(argv[0], "busybox")) {
- /* "busybox <applet> <params>" should still work as expected */
- argv++;
- }
- /* applet_names in this case is just "applet\0\0" */
- lbb_prepare(applet_names IF_FEATURE_INDIVIDUAL(, argv));
- # if ENABLE_BUILD_LIBBUSYBOX
- return SINGLE_APPLET_MAIN(string_array_len(argv), argv);
- # else
- return SINGLE_APPLET_MAIN(argc, argv);
- # endif
- #elif !ENABLE_BUSYBOX && NUM_APPLETS == 0
- full_write2_str(bb_basename(argv[0]));
- full_write2_str(": no applets enabled\n");
- exit(127);
- #else
- lbb_prepare("busybox" IF_FEATURE_INDIVIDUAL(, argv));
- # if !ENABLE_BUSYBOX
- if (argv[1] && is_prefixed_with(bb_basename(argv[0]), "busybox"))
- argv++;
- # endif
- applet_name = argv[0];
- if (applet_name[0] == '-')
- applet_name++;
- applet_name = bb_basename(applet_name);
- /* If we are a result of execv("/proc/self/exe"), fix ugly comm of "exe" */
- if (ENABLE_FEATURE_SH_STANDALONE
- || ENABLE_FEATURE_PREFER_APPLETS
- || !BB_MMU
- ) {
- if (NUM_APPLETS > 1)
- set_task_comm(applet_name);
- }
- parse_config_file(); /* ...maybe, if FEATURE_SUID_CONFIG */
- run_applet_and_exit(applet_name, argv);
- #endif
- }
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