Move applets/applet.c into libbb, allows to get rid of --whole-archive
(smaller code). Tested in static and shared mode.
This commit is contained in:
Denis Vlasenko
parent
82d38dab91
commit
724d196c75
@ -1,21 +1,15 @@
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/* vi: set sw=4 ts=4: */
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/*
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* Utility routines.
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* Stub for linking busybox binary against libbusybox.
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*
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* Copyright (C) tons of folks. Tracking down who wrote what
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* isn't something I'm going to worry about... If you wrote something
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* here, please feel free to acknowledge your work.
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* Copyright (C) 2007 Denis Vlasenko
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*
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* Based in part on code from sash, Copyright (c) 1999 by David I. Bell
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* Permission has been granted to redistribute this code under the GPL.
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*
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* Licensed under GPLv2 or later, see file License in this tarball for details.
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* Licensed under GPLv2, see file License in this tarball for details.
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*/
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#include <assert.h>
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#include "busybox.h"
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/* Apparently uclibc defines __GLIBC__ (compat trick?). Oh well. */
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#if ENABLE_STATIC && defined(__GLIBC__) && !defined(__UCLIBC__)
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#warning Static linking against glibc produces buggy executables
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@ -27,532 +21,9 @@
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#error Aborting compilation.
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#endif
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const char *applet_name;
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#if !BB_MMU
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bool re_execed;
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#endif
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USE_FEATURE_SUID(static uid_t ruid;) /* real uid */
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#if ENABLE_FEATURE_SUID_CONFIG
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/* applets[] is const, so we have to define this "override" structure */
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static struct BB_suid_config {
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const struct bb_applet *m_applet;
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uid_t m_uid;
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gid_t m_gid;
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mode_t m_mode;
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struct BB_suid_config *m_next;
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} *suid_config;
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static bool suid_cfg_readable;
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/* check if u is member of group g */
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static int ingroup(uid_t u, gid_t g)
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{
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struct group *grp = getgrgid(g);
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if (grp) {
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char **mem;
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for (mem = grp->gr_mem; *mem; mem++) {
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struct passwd *pwd = getpwnam(*mem);
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if (pwd && (pwd->pw_uid == u))
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return 1;
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}
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}
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return 0;
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}
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/* This should probably be a libbb routine. In that case,
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* I'd probably rename it to something like bb_trimmed_slice.
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*/
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static char *get_trimmed_slice(char *s, char *e)
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{
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/* First, consider the value at e to be nul and back up until we
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* reach a non-space char. Set the char after that (possibly at
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* the original e) to nul. */
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while (e-- > s) {
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if (!isspace(*e)) {
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break;
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}
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}
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e[1] = '\0';
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/* Next, advance past all leading space and return a ptr to the
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* first non-space char; possibly the terminating nul. */
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return skip_whitespace(s);
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}
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/* Don't depend on the tools to combine strings. */
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static const char config_file[] ALIGN1 = "/etc/busybox.conf";
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/* We don't supply a value for the nul, so an index adjustment is
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* necessary below. Also, we use unsigned short here to save some
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* space even though these are really mode_t values. */
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static const unsigned short mode_mask[] ALIGN2 = {
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/* SST sst xxx --- */
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S_ISUID, S_ISUID|S_IXUSR, S_IXUSR, 0, /* user */
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S_ISGID, S_ISGID|S_IXGRP, S_IXGRP, 0, /* group */
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0, S_IXOTH, S_IXOTH, 0 /* other */
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};
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#define parse_error(x) do { errmsg = x; goto pe_label; } while (0)
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static void parse_config_file(void)
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{
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struct BB_suid_config *sct_head;
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struct BB_suid_config *sct;
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const struct bb_applet *applet;
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FILE *f;
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const char *errmsg;
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char *s;
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char *e;
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int i;
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unsigned lc;
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smallint section;
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char buffer[256];
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struct stat st;
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assert(!suid_config); /* Should be set to NULL by bss init. */
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ruid = getuid();
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if (ruid == 0) /* run by root - don't need to even read config file */
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return;
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if ((stat(config_file, &st) != 0) /* No config file? */
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|| !S_ISREG(st.st_mode) /* Not a regular file? */
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|| (st.st_uid != 0) /* Not owned by root? */
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|| (st.st_mode & (S_IWGRP | S_IWOTH)) /* Writable by non-root? */
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|| !(f = fopen(config_file, "r")) /* Cannot open? */
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) {
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return;
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}
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suid_cfg_readable = 1;
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sct_head = NULL;
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section = lc = 0;
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while (1) {
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s = buffer;
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if (!fgets(s, sizeof(buffer), f)) { /* Are we done? */
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if (ferror(f)) { /* Make sure it wasn't a read error. */
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parse_error("reading");
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}
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fclose(f);
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suid_config = sct_head; /* Success, so set the pointer. */
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return;
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}
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lc++; /* Got a (partial) line. */
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/* If a line is too long for our buffer, we consider it an error.
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* The following test does mistreat one corner case though.
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* If the final line of the file does not end with a newline and
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* yet exactly fills the buffer, it will be treated as too long
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* even though there isn't really a problem. But it isn't really
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* worth adding code to deal with such an unlikely situation, and
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* we do err on the side of caution. Besides, the line would be
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* too long if it did end with a newline. */
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if (!strchr(s, '\n') && !feof(f)) {
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parse_error("line too long");
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}
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/* Trim leading and trailing whitespace, ignoring comments, and
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* check if the resulting string is empty. */
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s = get_trimmed_slice(s, strchrnul(s, '#'));
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if (!*s) {
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continue;
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}
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/* Check for a section header. */
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if (*s == '[') {
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/* Unlike the old code, we ignore leading and trailing
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* whitespace for the section name. We also require that
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* there are no stray characters after the closing bracket. */
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e = strchr(s, ']');
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if (!e /* Missing right bracket? */
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|| e[1] /* Trailing characters? */
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|| !*(s = get_trimmed_slice(s+1, e)) /* Missing name? */
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) {
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parse_error("section header");
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}
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/* Right now we only have one section so just check it.
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* If more sections are added in the future, please don't
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* resort to cascading ifs with multiple strcasecmp calls.
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* That kind of bloated code is all too common. A loop
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* and a string table would be a better choice unless the
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* number of sections is very small. */
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if (strcasecmp(s, "SUID") == 0) {
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section = 1;
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continue;
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}
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section = -1; /* Unknown section so set to skip. */
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continue;
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}
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/* Process sections. */
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if (section == 1) { /* SUID */
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/* Since we trimmed leading and trailing space above, we're
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* now looking for strings of the form
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* <key>[::space::]*=[::space::]*<value>
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* where both key and value could contain inner whitespace. */
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/* First get the key (an applet name in our case). */
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e = strchr(s, '=');
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if (e) {
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s = get_trimmed_slice(s, e);
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}
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if (!e || !*s) { /* Missing '=' or empty key. */
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parse_error("keyword");
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}
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/* Ok, we have an applet name. Process the rhs if this
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* applet is currently built in and ignore it otherwise.
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* Note: this can hide config file bugs which only pop
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* up when the busybox configuration is changed. */
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applet = find_applet_by_name(s);
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if (applet) {
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/* Note: We currently don't check for duplicates!
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* The last config line for each applet will be the
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* one used since we insert at the head of the list.
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* I suppose this could be considered a feature. */
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sct = xmalloc(sizeof(struct BB_suid_config));
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sct->m_applet = applet;
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sct->m_mode = 0;
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sct->m_next = sct_head;
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sct_head = sct;
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/* Get the specified mode. */
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e = skip_whitespace(e+1);
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for (i = 0; i < 3; i++) {
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/* There are 4 chars + 1 nul for each of user/group/other. */
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static const char mode_chars[] ALIGN1 = "Ssx-\0" "Ssx-\0" "Ttx-";
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const char *q;
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q = strchrnul(mode_chars + 5*i, *e++);
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if (!*q) {
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parse_error("mode");
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}
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/* Adjust by -i to account for nul. */
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sct->m_mode |= mode_mask[(q - mode_chars) - i];
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}
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/* Now get the the user/group info. */
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s = skip_whitespace(e);
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/* Note: we require whitespace between the mode and the
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* user/group info. */
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if ((s == e) || !(e = strchr(s, '.'))) {
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parse_error("<uid>.<gid>");
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}
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*e++ = '\0';
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/* We can't use get_ug_id here since it would exit()
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* if a uid or gid was not found. Oh well... */
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sct->m_uid = bb_strtoul(s, NULL, 10);
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if (errno) {
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struct passwd *pwd = getpwnam(s);
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if (!pwd) {
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parse_error("user");
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}
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sct->m_uid = pwd->pw_uid;
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}
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sct->m_gid = bb_strtoul(e, NULL, 10);
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if (errno) {
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struct group *grp;
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grp = getgrnam(e);
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if (!grp) {
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parse_error("group");
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}
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sct->m_gid = grp->gr_gid;
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}
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}
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continue;
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}
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/* Unknown sections are ignored. */
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/* Encountering configuration lines prior to seeing a
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* section header is treated as an error. This is how
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* the old code worked, but it may not be desirable.
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* We may want to simply ignore such lines in case they
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* are used in some future version of busybox. */
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if (!section) {
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parse_error("keyword outside section");
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}
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} /* while (1) */
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pe_label:
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fprintf(stderr, "Parse error in %s, line %d: %s\n",
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config_file, lc, errmsg);
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fclose(f);
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/* Release any allocated memory before returning. */
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while (sct_head) {
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sct = sct_head->m_next;
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free(sct_head);
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sct_head = sct;
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}
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}
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#else
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static inline void parse_config_file(void)
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{
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USE_FEATURE_SUID(ruid = getuid();)
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}
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#endif /* FEATURE_SUID_CONFIG */
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#if ENABLE_FEATURE_SUID
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static void check_suid(const struct bb_applet *applet)
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{
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gid_t rgid; /* real gid */
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if (ruid == 0) /* set by parse_config_file() */
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return; /* run by root - no need to check more */
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rgid = getgid();
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#if ENABLE_FEATURE_SUID_CONFIG
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if (suid_cfg_readable) {
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uid_t uid;
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struct BB_suid_config *sct;
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mode_t m;
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for (sct = suid_config; sct; sct = sct->m_next) {
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if (sct->m_applet == applet)
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goto found;
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}
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/* default: drop all privileges */
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xsetgid(rgid);
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xsetuid(ruid);
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return;
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found:
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m = sct->m_mode;
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if (sct->m_uid == ruid)
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/* same uid */
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m >>= 6;
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else if ((sct->m_gid == rgid) || ingroup(ruid, sct->m_gid))
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/* same group / in group */
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m >>= 3;
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if (!(m & S_IXOTH)) /* is x bit not set ? */
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bb_error_msg_and_die("you have no permission to run this applet!");
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/* _both_ sgid and group_exec have to be set for setegid */
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if ((sct->m_mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP))
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rgid = sct->m_gid;
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/* else (no setegid) we will set egid = rgid */
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/* We set effective AND saved ids. If saved-id is not set
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* like we do below, seteiud(0) can still later succeed! */
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if (setresgid(-1, rgid, rgid))
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bb_perror_msg_and_die("setresgid");
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/* do we have to set effective uid? */
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uid = ruid;
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if (sct->m_mode & S_ISUID)
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uid = sct->m_uid;
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/* else (no seteuid) we will set euid = ruid */
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if (setresuid(-1, uid, uid))
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bb_perror_msg_and_die("setresuid");
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return;
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}
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#if !ENABLE_FEATURE_SUID_CONFIG_QUIET
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{
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static bool onetime = 0;
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if (!onetime) {
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onetime = 1;
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fprintf(stderr, "Using fallback suid method\n");
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}
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}
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#endif
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#endif
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if (applet->need_suid == _BB_SUID_ALWAYS) {
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/* Real uid is not 0. If euid isn't 0 too, suid bit
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* is most probably not set on our executable */
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if (geteuid())
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bb_error_msg_and_die("applet requires root privileges!");
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} else if (applet->need_suid == _BB_SUID_NEVER) {
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xsetgid(rgid); /* drop all privileges */
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xsetuid(ruid);
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}
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}
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#else
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#define check_suid(x) ((void)0)
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#endif /* FEATURE_SUID */
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#if ENABLE_FEATURE_INSTALLER
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/* create (sym)links for each applet */
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static void install_links(const char *busybox, int use_symbolic_links)
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{
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/* directory table
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* this should be consistent w/ the enum,
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* busybox.h::bb_install_loc_t, or else... */
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static const char usr_bin [] ALIGN1 = "/usr/bin";
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static const char usr_sbin[] ALIGN1 = "/usr/sbin";
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static const char *const install_dir[] = {
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&usr_bin [8], /* "", equivalent to "/" for concat_path_file() */
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&usr_bin [4], /* "/bin" */
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&usr_sbin[4], /* "/sbin" */
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usr_bin,
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usr_sbin
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};
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int (*lf)(const char *, const char *) = link;
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char *fpc;
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int i;
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int rc;
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if (use_symbolic_links)
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lf = symlink;
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for (i = 0; applets[i].name != NULL; i++) {
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fpc = concat_path_file(
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install_dir[applets[i].install_loc],
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applets[i].name);
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rc = lf(busybox, fpc);
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if (rc != 0 && errno != EEXIST) {
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bb_simple_perror_msg(fpc);
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}
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free(fpc);
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}
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}
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#else
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#define install_links(x,y) ((void)0)
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#endif /* FEATURE_INSTALLER */
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/* If we were called as "busybox..." */
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static int busybox_main(char **argv)
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{
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if (!argv[1]) {
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/* Called without arguments */
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const struct bb_applet *a;
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int col, output_width;
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help:
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output_width = 80;
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if (ENABLE_FEATURE_AUTOWIDTH) {
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/* Obtain the terminal width */
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get_terminal_width_height(0, &output_width, NULL);
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}
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/* leading tab and room to wrap */
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output_width -= sizeof("start-stop-daemon, ") + 8;
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printf("%s multi-call binary\n", bb_banner); /* reuse const string... */
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printf("Copyright (C) 1998-2006 Erik Andersen, Rob Landley, and others.\n"
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"Licensed under GPLv2. See source distribution for full notice.\n"
|
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"\n"
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"Usage: busybox [function] [arguments]...\n"
|
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" or: [function] [arguments]...\n"
|
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"\n"
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"\tBusyBox is a multi-call binary that combines many common Unix\n"
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"\tutilities into a single executable. Most people will create a\n"
|
||||
"\tlink to busybox for each function they wish to use and BusyBox\n"
|
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"\twill act like whatever it was invoked as!\n"
|
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"\nCurrently defined functions:\n");
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col = 0;
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a = applets;
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while (a->name) {
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if (col > output_width) {
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puts(",");
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col = 0;
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}
|
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col += printf("%s%s", (col ? ", " : "\t"), a->name);
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a++;
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}
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puts("\n");
|
||||
return 0;
|
||||
}
|
||||
|
||||
if (ENABLE_FEATURE_INSTALLER && strcmp(argv[1], "--install") == 0) {
|
||||
const char *busybox;
|
||||
busybox = xmalloc_readlink(bb_busybox_exec_path);
|
||||
if (!busybox)
|
||||
busybox = bb_busybox_exec_path;
|
||||
/* -s makes symlinks */
|
||||
install_links(busybox, argv[2] && strcmp(argv[2], "-s") == 0);
|
||||
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);
|
||||
bb_error_msg_and_die("applet not found");
|
||||
}
|
||||
|
||||
void run_appletstruct_and_exit(const struct bb_applet *applet, char **argv)
|
||||
{
|
||||
int argc = 1;
|
||||
|
||||
while (argv[argc])
|
||||
argc++;
|
||||
|
||||
/* Reinit some shared global data */
|
||||
optind = 1;
|
||||
xfunc_error_retval = EXIT_FAILURE;
|
||||
|
||||
applet_name = applet->name;
|
||||
if (argc == 2 && !strcmp(argv[1], "--help"))
|
||||
bb_show_usage();
|
||||
if (ENABLE_FEATURE_SUID)
|
||||
check_suid(applet);
|
||||
exit(applet->main(argc, argv));
|
||||
}
|
||||
|
||||
void run_applet_and_exit(const char *name, char **argv)
|
||||
{
|
||||
const struct bb_applet *applet = find_applet_by_name(name);
|
||||
if (applet)
|
||||
run_appletstruct_and_exit(applet, argv);
|
||||
if (!strncmp(name, "busybox", 7))
|
||||
exit(busybox_main(argv));
|
||||
}
|
||||
|
||||
|
||||
#if ENABLE_BUILD_LIBBUSYBOX
|
||||
int main(int argc, char **argv)
|
||||
{
|
||||
bbox_prepare_main(argv);
|
||||
|
||||
#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
|
||||
applet_name = argv[0];
|
||||
if (applet_name[0] == '-')
|
||||
applet_name++;
|
||||
applet_name = bb_basename(applet_name);
|
||||
|
||||
parse_config_file(); /* ...maybe, if FEATURE_SUID_CONFIG */
|
||||
|
||||
run_applet_and_exit(applet_name, argv);
|
||||
bb_error_msg_and_die("applet not found");
|
||||
return libbusybox_main(argc, argv);
|
||||
}
|
||||
#endif
|
||||
|
||||
@ -52,5 +52,8 @@ struct bb_applet {
|
||||
extern const struct bb_applet applets[];
|
||||
extern const unsigned short NUM_APPLETS;
|
||||
void bbox_prepare_main(char **argv);
|
||||
#if ENABLE_BUILD_LIBBUSYBOX
|
||||
int libbusybox_main(int argc, char **argv);
|
||||
#endif
|
||||
|
||||
#endif /* _BB_INTERNAL_H_ */
|
||||
|
||||
@ -1,11 +1,15 @@
|
||||
/* vi: set sw=4 ts=4: */
|
||||
/*
|
||||
* Support for main() which needs to end up in libbusybox, not busybox,
|
||||
* if one builds libbusybox.
|
||||
* Utility routines.
|
||||
*
|
||||
* Copyright (C) 2007 Denys Vlasenko <vda.linux@googlemail.com>
|
||||
* 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.
|
||||
*
|
||||
* Licensed under GPLv2, see file License in this tarball for details.
|
||||
* Based in part on code from sash, Copyright (c) 1999 by David I. Bell
|
||||
* Permission has been granted to redistribute this code under the GPL.
|
||||
*
|
||||
* Licensed under GPLv2 or later, see file License in this tarball for details.
|
||||
*/
|
||||
|
||||
#include <assert.h>
|
||||
@ -140,3 +144,544 @@ void bbox_prepare_main(char **argv)
|
||||
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
|
||||
|
||||
USE_FEATURE_SUID(static uid_t ruid;) /* real uid */
|
||||
|
||||
#if ENABLE_FEATURE_SUID_CONFIG
|
||||
|
||||
/* applets[] is const, so we have to define this "override" structure */
|
||||
static struct BB_suid_config {
|
||||
const struct bb_applet *m_applet;
|
||||
uid_t m_uid;
|
||||
gid_t m_gid;
|
||||
mode_t m_mode;
|
||||
struct BB_suid_config *m_next;
|
||||
} *suid_config;
|
||||
|
||||
static bool suid_cfg_readable;
|
||||
|
||||
/* 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;
|
||||
}
|
||||
|
||||
/* This should probably be a libbb routine. In that case,
|
||||
* I'd probably rename it to something like bb_trimmed_slice.
|
||||
*/
|
||||
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);
|
||||
}
|
||||
|
||||
/* Don't depend on the tools to combine strings. */
|
||||
static const char config_file[] ALIGN1 = "/etc/busybox.conf";
|
||||
|
||||
/* We don't supply a value for the nul, so an index adjustment is
|
||||
* necessary below. Also, we use unsigned short here to save some
|
||||
* space even though these are really mode_t values. */
|
||||
static const unsigned short mode_mask[] ALIGN2 = {
|
||||
/* SST sst xxx --- */
|
||||
S_ISUID, S_ISUID|S_IXUSR, S_IXUSR, 0, /* user */
|
||||
S_ISGID, S_ISGID|S_IXGRP, S_IXGRP, 0, /* group */
|
||||
0, S_IXOTH, S_IXOTH, 0 /* other */
|
||||
};
|
||||
|
||||
#define parse_error(x) do { errmsg = x; goto pe_label; } while (0)
|
||||
|
||||
static void parse_config_file(void)
|
||||
{
|
||||
struct BB_suid_config *sct_head;
|
||||
struct BB_suid_config *sct;
|
||||
const struct bb_applet *applet;
|
||||
FILE *f;
|
||||
const char *errmsg;
|
||||
char *s;
|
||||
char *e;
|
||||
int i;
|
||||
unsigned lc;
|
||||
smallint section;
|
||||
char buffer[256];
|
||||
struct stat st;
|
||||
|
||||
assert(!suid_config); /* Should be set to NULL by bss init. */
|
||||
|
||||
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(config_file, "r")) /* Cannot open? */
|
||||
) {
|
||||
return;
|
||||
}
|
||||
|
||||
suid_cfg_readable = 1;
|
||||
sct_head = NULL;
|
||||
section = lc = 0;
|
||||
|
||||
while (1) {
|
||||
s = buffer;
|
||||
|
||||
if (!fgets(s, sizeof(buffer), f)) { /* Are we done? */
|
||||
if (ferror(f)) { /* Make sure it wasn't a read error. */
|
||||
parse_error("reading");
|
||||
}
|
||||
fclose(f);
|
||||
suid_config = sct_head; /* Success, so set the pointer. */
|
||||
return;
|
||||
}
|
||||
|
||||
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)) {
|
||||
parse_error("line too long");
|
||||
}
|
||||
|
||||
/* 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. */
|
||||
e = strchr(s, ']');
|
||||
if (!e /* Missing right bracket? */
|
||||
|| e[1] /* Trailing characters? */
|
||||
|| !*(s = get_trimmed_slice(s+1, e)) /* Missing name? */
|
||||
) {
|
||||
parse_error("section header");
|
||||
}
|
||||
/* 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). */
|
||||
e = strchr(s, '=');
|
||||
if (e) {
|
||||
s = get_trimmed_slice(s, e);
|
||||
}
|
||||
if (!e || !*s) { /* Missing '=' or empty key. */
|
||||
parse_error("keyword");
|
||||
}
|
||||
|
||||
/* 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 = find_applet_by_name(s);
|
||||
if (applet) {
|
||||
/* 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 = xmalloc(sizeof(struct BB_suid_config));
|
||||
sct->m_applet = applet;
|
||||
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 + 1 nul for each of user/group/other. */
|
||||
static const char mode_chars[] ALIGN1 = "Ssx-\0" "Ssx-\0" "Ttx-";
|
||||
|
||||
const char *q;
|
||||
q = strchrnul(mode_chars + 5*i, *e++);
|
||||
if (!*q) {
|
||||
parse_error("mode");
|
||||
}
|
||||
/* Adjust by -i to account for nul. */
|
||||
sct->m_mode |= mode_mask[(q - mode_chars) - i];
|
||||
}
|
||||
|
||||
/* Now get the the user/group info. */
|
||||
|
||||
s = skip_whitespace(e);
|
||||
|
||||
/* Note: we require whitespace between the mode and the
|
||||
* user/group info. */
|
||||
if ((s == e) || !(e = strchr(s, '.'))) {
|
||||
parse_error("<uid>.<gid>");
|
||||
}
|
||||
*e++ = '\0';
|
||||
|
||||
/* We can't use get_ug_id here since it would exit()
|
||||
* if a uid or gid was not found. Oh well... */
|
||||
sct->m_uid = bb_strtoul(s, NULL, 10);
|
||||
if (errno) {
|
||||
struct passwd *pwd = getpwnam(s);
|
||||
if (!pwd) {
|
||||
parse_error("user");
|
||||
}
|
||||
sct->m_uid = pwd->pw_uid;
|
||||
}
|
||||
|
||||
sct->m_gid = bb_strtoul(e, NULL, 10);
|
||||
if (errno) {
|
||||
struct group *grp;
|
||||
grp = getgrnam(e);
|
||||
if (!grp) {
|
||||
parse_error("group");
|
||||
}
|
||||
sct->m_gid = grp->gr_gid;
|
||||
}
|
||||
}
|
||||
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) {
|
||||
parse_error("keyword outside section");
|
||||
}
|
||||
|
||||
} /* while (1) */
|
||||
|
||||
pe_label:
|
||||
fprintf(stderr, "Parse error in %s, line %d: %s\n",
|
||||
config_file, lc, errmsg);
|
||||
|
||||
fclose(f);
|
||||
/* Release any allocated memory before returning. */
|
||||
while (sct_head) {
|
||||
sct = sct_head->m_next;
|
||||
free(sct_head);
|
||||
sct_head = sct;
|
||||
}
|
||||
}
|
||||
#else
|
||||
static inline void parse_config_file(void)
|
||||
{
|
||||
USE_FEATURE_SUID(ruid = getuid();)
|
||||
}
|
||||
#endif /* FEATURE_SUID_CONFIG */
|
||||
|
||||
|
||||
#if ENABLE_FEATURE_SUID
|
||||
static void check_suid(const struct bb_applet *applet)
|
||||
{
|
||||
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 BB_suid_config *sct;
|
||||
mode_t m;
|
||||
|
||||
for (sct = suid_config; sct; sct = sct->m_next) {
|
||||
if (sct->m_applet == applet)
|
||||
goto found;
|
||||
}
|
||||
/* default: drop all privileges */
|
||||
xsetgid(rgid);
|
||||
xsetuid(ruid);
|
||||
return;
|
||||
found:
|
||||
m = sct->m_mode;
|
||||
if (sct->m_uid == ruid)
|
||||
/* same uid */
|
||||
m >>= 6;
|
||||
else if ((sct->m_gid == rgid) || ingroup(ruid, sct->m_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!");
|
||||
|
||||
/* _both_ sgid and group_exec have to be set for setegid */
|
||||
if ((sct->m_mode & (S_ISGID | S_IXGRP)) == (S_ISGID | S_IXGRP))
|
||||
rgid = sct->m_gid;
|
||||
/* else (no setegid) we will set egid = rgid */
|
||||
|
||||
/* We set effective AND saved ids. If saved-id is not set
|
||||
* like we do below, seteiud(0) can still later succeed! */
|
||||
if (setresgid(-1, rgid, rgid))
|
||||
bb_perror_msg_and_die("setresgid");
|
||||
|
||||
/* do we have to set effective uid? */
|
||||
uid = ruid;
|
||||
if (sct->m_mode & S_ISUID)
|
||||
uid = sct->m_uid;
|
||||
/* else (no seteuid) we will set euid = ruid */
|
||||
|
||||
if (setresuid(-1, uid, uid))
|
||||
bb_perror_msg_and_die("setresuid");
|
||||
return;
|
||||
}
|
||||
#if !ENABLE_FEATURE_SUID_CONFIG_QUIET
|
||||
{
|
||||
static bool onetime = 0;
|
||||
|
||||
if (!onetime) {
|
||||
onetime = 1;
|
||||
fprintf(stderr, "Using fallback suid method\n");
|
||||
}
|
||||
}
|
||||
#endif
|
||||
#endif
|
||||
|
||||
if (applet->need_suid == _BB_SUID_ALWAYS) {
|
||||
/* 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("applet requires root privileges!");
|
||||
} else if (applet->need_suid == _BB_SUID_NEVER) {
|
||||
xsetgid(rgid); /* drop all privileges */
|
||||
xsetuid(ruid);
|
||||
}
|
||||
}
|
||||
#else
|
||||
#define check_suid(x) ((void)0)
|
||||
#endif /* FEATURE_SUID */
|
||||
|
||||
|
||||
#if ENABLE_FEATURE_INSTALLER
|
||||
/* create (sym)links for each applet */
|
||||
static void install_links(const char *busybox, int use_symbolic_links)
|
||||
{
|
||||
/* directory table
|
||||
* this should be consistent w/ the enum,
|
||||
* busybox.h::bb_install_loc_t, or else... */
|
||||
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], /* "", equivalent to "/" for concat_path_file() */
|
||||
&usr_bin [4], /* "/bin" */
|
||||
&usr_sbin[4], /* "/sbin" */
|
||||
usr_bin,
|
||||
usr_sbin
|
||||
};
|
||||
|
||||
int (*lf)(const char *, const char *) = link;
|
||||
char *fpc;
|
||||
int i;
|
||||
int rc;
|
||||
|
||||
if (use_symbolic_links)
|
||||
lf = symlink;
|
||||
|
||||
for (i = 0; applets[i].name != NULL; i++) {
|
||||
fpc = concat_path_file(
|
||||
install_dir[applets[i].install_loc],
|
||||
applets[i].name);
|
||||
rc = lf(busybox, fpc);
|
||||
if (rc != 0 && errno != EEXIST) {
|
||||
bb_simple_perror_msg(fpc);
|
||||
}
|
||||
free(fpc);
|
||||
}
|
||||
}
|
||||
#else
|
||||
#define install_links(x,y) ((void)0)
|
||||
#endif /* FEATURE_INSTALLER */
|
||||
|
||||
/* If we were called as "busybox..." */
|
||||
static int busybox_main(char **argv)
|
||||
{
|
||||
if (!argv[1]) {
|
||||
/* Called without arguments */
|
||||
const struct bb_applet *a;
|
||||
int col, output_width;
|
||||
help:
|
||||
output_width = 80;
|
||||
if (ENABLE_FEATURE_AUTOWIDTH) {
|
||||
/* Obtain the terminal width */
|
||||
get_terminal_width_height(0, &output_width, NULL);
|
||||
}
|
||||
/* leading tab and room to wrap */
|
||||
output_width -= sizeof("start-stop-daemon, ") + 8;
|
||||
|
||||
printf("%s multi-call binary\n", bb_banner); /* reuse const string... */
|
||||
printf("Copyright (C) 1998-2006 Erik Andersen, Rob Landley, and others.\n"
|
||||
"Licensed under GPLv2. See source distribution for full notice.\n"
|
||||
"\n"
|
||||
"Usage: busybox [function] [arguments]...\n"
|
||||
" or: [function] [arguments]...\n"
|
||||
"\n"
|
||||
"\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"
|
||||
"\nCurrently defined functions:\n");
|
||||
col = 0;
|
||||
a = applets;
|
||||
while (a->name) {
|
||||
if (col > output_width) {
|
||||
puts(",");
|
||||
col = 0;
|
||||
}
|
||||
col += printf("%s%s", (col ? ", " : "\t"), a->name);
|
||||
a++;
|
||||
}
|
||||
puts("\n");
|
||||
return 0;
|
||||
}
|
||||
|
||||
if (ENABLE_FEATURE_INSTALLER && strcmp(argv[1], "--install") == 0) {
|
||||
const char *busybox;
|
||||
busybox = xmalloc_readlink(bb_busybox_exec_path);
|
||||
if (!busybox)
|
||||
busybox = bb_busybox_exec_path;
|
||||
/* -s makes symlinks */
|
||||
install_links(busybox, argv[2] && strcmp(argv[2], "-s") == 0);
|
||||
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);
|
||||
bb_error_msg_and_die("applet not found");
|
||||
}
|
||||
|
||||
void run_appletstruct_and_exit(const struct bb_applet *applet, char **argv)
|
||||
{
|
||||
int argc = 1;
|
||||
|
||||
while (argv[argc])
|
||||
argc++;
|
||||
|
||||
/* Reinit some shared global data */
|
||||
optind = 1;
|
||||
xfunc_error_retval = EXIT_FAILURE;
|
||||
|
||||
applet_name = applet->name;
|
||||
if (argc == 2 && !strcmp(argv[1], "--help"))
|
||||
bb_show_usage();
|
||||
if (ENABLE_FEATURE_SUID)
|
||||
check_suid(applet);
|
||||
exit(applet->main(argc, argv));
|
||||
}
|
||||
|
||||
void run_applet_and_exit(const char *name, char **argv)
|
||||
{
|
||||
const struct bb_applet *applet = find_applet_by_name(name);
|
||||
if (applet)
|
||||
run_appletstruct_and_exit(applet, argv);
|
||||
if (!strncmp(name, "busybox", 7))
|
||||
exit(busybox_main(argv));
|
||||
}
|
||||
|
||||
|
||||
#if ENABLE_BUILD_LIBBUSYBOX
|
||||
int libbusybox_main(int argc, char **argv)
|
||||
#else
|
||||
int main(int argc, char **argv)
|
||||
#endif
|
||||
{
|
||||
bbox_prepare_main(argv);
|
||||
|
||||
#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
|
||||
applet_name = argv[0];
|
||||
if (applet_name[0] == '-')
|
||||
applet_name++;
|
||||
applet_name = bb_basename(applet_name);
|
||||
|
||||
parse_config_file(); /* ...maybe, if FEATURE_SUID_CONFIG */
|
||||
|
||||
run_applet_and_exit(applet_name, argv);
|
||||
bb_error_msg_and_die("applet not found");
|
||||
}
|
||||
|
||||
@ -19,18 +19,16 @@ debug=false
|
||||
# List of files to link:
|
||||
# $l_list == --start-group -llib1 -llib2 --end-group
|
||||
# --start-group $O_FILES $A_FILES --end-group
|
||||
# or for shlib:
|
||||
# --start-group --whole-archive $A_FILES --no-whole-archive --end-group
|
||||
# otherwise we don't pull in all parts of *.a files. Now we pull in too much.
|
||||
# FIXME: make it work without --whole-archive, or better, with --gc-sections.
|
||||
#
|
||||
# Shared library link:
|
||||
# -shared self-explanatory
|
||||
# -fPIC position-independent code
|
||||
# -Wl,--enable-new-dtags ?
|
||||
# -Wl,-z,combreloc ?
|
||||
# -Wl,-soname="libbusybox.so.$BB_VER"
|
||||
# -static Not used, but may be useful! manpage:
|
||||
# --enable-new-dtags ?
|
||||
# -z,combreloc ?
|
||||
# -soname="libbusybox.so.$BB_VER"
|
||||
# --undefined=libbusybox_main Seed name to start pulling from
|
||||
# (otherwise we'll need --whole-archive)
|
||||
# -static Not used, but may be useful! manpage:
|
||||
# "... This option can be used with -shared.
|
||||
# Doing so means that a shared library
|
||||
# is being created but that all of the library's
|
||||
@ -174,9 +172,10 @@ if test "$CONFIG_BUILD_LIBBUSYBOX" = y; then
|
||||
-Wl,--enable-new-dtags \
|
||||
-Wl,-z,combreloc \
|
||||
-Wl,-soname="libbusybox.so.$BB_VER" \
|
||||
-Wl,--undefined=libbusybox_main \
|
||||
-Wl,--sort-common \
|
||||
-Wl,--sort-section -Wl,alignment \
|
||||
-Wl,--start-group -Wl,--whole-archive $A_FILES -Wl,--no-whole-archive -Wl,--end-group \
|
||||
-Wl,--start-group $A_FILES -Wl,--end-group \
|
||||
$l_list \
|
||||
-Wl,--warn-common \
|
||||
-Wl,-Map -Wl,$EXE.map \
|
||||
|
||||
Loading…
Reference in New Issue
Block a user