2006-05-19 13:12:21 +00:00
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/* vi: set sw=4 ts=4: */
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2003-07-28 07:40:39 +00:00
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/*
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2004-04-14 17:51:38 +00:00
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* Rexec program for system have fork() as vfork() with foreground option
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2003-12-15 21:57:44 +00:00
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*
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* Copyright (C) Vladimir N. Oleynik <dzo@simtreas.ru>
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* Copyright (C) 2003 Russ Dill <Russ.Dill@asu.edu>
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*
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2004-04-14 17:51:38 +00:00
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* daemon() portion taken from uClibc:
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2003-12-15 21:57:44 +00:00
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*
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* Copyright (c) 1991, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Modified for uClibc by Erik Andersen <andersee@debian.org>
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*
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2006-05-19 13:12:21 +00:00
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* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
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2003-07-28 07:40:39 +00:00
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*/
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2003-12-15 21:57:44 +00:00
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#include <paths.h>
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2007-04-09 21:32:30 +00:00
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#include "busybox.h" /* for struct BB_applet */
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2003-07-28 07:40:39 +00:00
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2007-03-26 13:20:04 +00:00
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/* This does a fork/exec in one call, using vfork(). Returns PID of new child,
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* -1 for failure. Runs argv[0], searching path if that has no / in it. */
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pid_t spawn(char **argv)
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{
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/* Compiler should not optimize stores here */
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volatile int failed;
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pid_t pid;
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2007-04-09 13:04:50 +00:00
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|
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// Ain't it a good place to fflush(NULL)?
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/* Be nice to nommu machines. */
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2007-03-26 13:20:04 +00:00
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failed = 0;
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pid = vfork();
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if (pid < 0) /* error */
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return pid;
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if (!pid) { /* child */
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2007-04-09 13:04:50 +00:00
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/* This macro is ok - it doesn't do NOEXEC/NOFORK tricks */
|
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BB_EXECVP(argv[0], argv);
|
2007-03-26 13:20:04 +00:00
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/* We are (maybe) sharing a stack with blocked parent,
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|
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* let parent know we failed and then exit to unblock parent
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* (but don't run atexit() stuff, which would screw up parent.)
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|
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*/
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failed = errno;
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2007-03-26 17:25:33 +00:00
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_exit(111);
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2007-03-26 13:20:04 +00:00
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}
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/* parent */
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2007-03-26 17:25:33 +00:00
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|
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/* Unfortunately, this is not reliable: according to standards
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|
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* vfork() can be equivalent to fork() and we won't see value
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* of 'failed'.
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* Interested party can wait on pid and learn exit code.
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* If 111 - then it (most probably) failed to exec */
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2007-03-26 13:20:04 +00:00
|
|
|
if (failed) {
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errno = failed;
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return -1;
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}
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return pid;
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}
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/* Die with an error message if we can't spawn a child process. */
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pid_t xspawn(char **argv)
|
|
|
|
{
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pid_t pid = spawn(argv);
|
2007-04-09 13:21:33 +00:00
|
|
|
if (pid < 0)
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bb_perror_msg_and_die("%s", *argv);
|
2007-03-26 13:20:04 +00:00
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return pid;
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|
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}
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2007-04-09 13:21:33 +00:00
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// Wait for the specified child PID to exit, returning child's error return.
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int wait4pid(int pid)
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|
|
|
{
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|
|
int status;
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|
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|
|
|
|
if (pid <= 0) {
|
2007-04-09 21:32:30 +00:00
|
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|
/*errno = ECHILD; -- wrong. */
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|
/* we expect errno to be already set from failed [v]fork/exec */
|
2007-04-09 13:21:33 +00:00
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|
return -1;
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|
}
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|
if (waitpid(pid, &status, 0) == -1)
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|
return -1;
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|
|
|
if (WIFEXITED(status))
|
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|
|
return WEXITSTATUS(status);
|
|
|
|
if (WIFSIGNALED(status))
|
2007-04-09 21:32:30 +00:00
|
|
|
return WTERMSIG(status) + 1000;
|
2007-04-09 13:21:33 +00:00
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|
|
return 0;
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|
|
|
}
|
2007-03-26 13:20:04 +00:00
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|
2007-04-09 13:21:33 +00:00
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|
|
int wait_nohang(int *wstat)
|
|
|
|
{
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|
|
|
return waitpid(-1, wstat, WNOHANG);
|
|
|
|
}
|
|
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int wait_pid(int *wstat, int pid)
|
|
|
|
{
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|
|
|
int r;
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|
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|
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|
|
do
|
|
|
|
r = waitpid(pid, wstat, 0);
|
|
|
|
while ((r == -1) && (errno == EINTR));
|
|
|
|
return r;
|
|
|
|
}
|
2007-03-26 13:20:04 +00:00
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|
2007-04-09 21:32:30 +00:00
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|
|
int spawn_and_wait(char **argv)
|
|
|
|
{
|
|
|
|
int rc;
|
|
|
|
|
|
|
|
if (ENABLE_FEATURE_EXEC_PREFER_APPLETS) {
|
|
|
|
const struct BB_applet *a = find_applet_by_name(argv[0]);
|
|
|
|
if (a && (a->nofork
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|
|
|
#ifndef BB_NOMMU
|
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|
|| a->noexec /* NOEXEC cannot be used on NOMMU */
|
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|
|
#endif
|
|
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|
)) {
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|
int argc = 1;
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|
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|
char **pp = argv;
|
|
|
|
while (*++pp)
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|
argc++;
|
2007-04-09 21:35:07 +00:00
|
|
|
#ifndef BB_NOMMU
|
2007-04-09 21:32:30 +00:00
|
|
|
if (a->nofork)
|
2007-04-09 21:35:07 +00:00
|
|
|
#endif
|
|
|
|
{
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|
|
|
int old_sleep = die_sleep;
|
|
|
|
die_sleep = -1; /* special flag */
|
|
|
|
/* sleep_and_die() checks for it */
|
|
|
|
rc = setjmp(die_jmp);
|
|
|
|
if (!rc) {
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|
|
|
const struct BB_applet *old_a = current_applet;
|
|
|
|
current_applet = a;
|
|
|
|
applet_name = a->name;
|
|
|
|
// what else should we save/restore?
|
|
|
|
rc = a->main(argc, argv);
|
|
|
|
current_applet = old_a;
|
|
|
|
applet_name = old_a->name;
|
|
|
|
}
|
|
|
|
die_sleep = old_sleep;
|
|
|
|
return rc;
|
|
|
|
}
|
|
|
|
#ifndef BB_NOMMU /* MMU only */
|
2007-04-09 21:32:30 +00:00
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|
|
/* a->noexec is true */
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|
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|
rc = fork();
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|
|
|
if (rc)
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|
|
|
goto w;
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|
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|
/* child */
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|
|
|
current_applet = a;
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|
|
|
run_current_applet_and_exit(argc, argv);
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|
|
|
#endif
|
|
|
|
}
|
|
|
|
}
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|
rc = spawn(argv);
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|
w:
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|
return wait4pid(rc);
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|
|
|
}
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|
2007-04-09 21:35:07 +00:00
|
|
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|
2007-03-26 13:20:04 +00:00
|
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|
#if 0 //ndef BB_NOMMU
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|
// Die with an error message if we can't daemonize.
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|
void xdaemon(int nochdir, int noclose)
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|
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|
{
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|
if (daemon(nochdir, noclose))
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|
bb_perror_msg_and_die("daemon");
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|
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|
}
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|
#endif
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|
#if 0 // def BB_NOMMU
|
2007-03-24 12:11:17 +00:00
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|
void vfork_daemon_rexec(int nochdir, int noclose, char **argv)
|
2003-07-28 07:40:39 +00:00
|
|
|
{
|
2003-12-15 21:57:44 +00:00
|
|
|
int fd;
|
2004-03-15 08:29:22 +00:00
|
|
|
|
2007-03-26 13:20:04 +00:00
|
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|
/* Maybe we are already re-execed and come here again? */
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|
if (re_execed)
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|
return;
|
|
|
|
|
2003-12-15 21:57:44 +00:00
|
|
|
setsid();
|
2004-03-15 08:29:22 +00:00
|
|
|
|
2003-12-15 21:57:44 +00:00
|
|
|
if (!nochdir)
|
- merge -r15463:15564 from busybox_scratch branch through these changesets:
------------------------------------------------------------------------
r15465 | aldot | 2006-06-21 20:48:06 +0200 (Wed, 21 Jun 2006) | 3 lines
- use CONFIG_BUSYBOX_EXEC_PATH as before it one was broken by a recent revert.
- use xchdir() since all is invain if it fails there anyways, supposedly
------------------------------------------------------------------------
r15466 | aldot | 2006-06-21 20:55:16 +0200 (Wed, 21 Jun 2006) | 2 lines
- adjust docs to take CONFIG_BUSYBOX_EXEC_PATH into account.
------------------------------------------------------------------------
r15467 | aldot | 2006-06-21 21:31:24 +0200 (Wed, 21 Jun 2006) | 18 lines
- partial fallout of my TREE_USED touchup against gcc-4.2: rip unused vars, save
s 144 bytes
text data bss dec hex filename
862434 10156 645924 1518514 172bb2 busybox.old
862322 10156 645892 1518370 172b22 busybox
function old new delta
z_len 4 - -4
textend 4 - -4
part_nb 4 - -4
insize 4 - -4
ifile_size 4 - -4
do_link 4 - -4
new_text 70 60 -10
ipaddr_list_link 33 23 -10
gzip_main 898 822 -76
------------------------------------------------------------------------------
(add/remove: 0/6 grow/shrink: 0/3 up/down: 0/-120) Total: -120 bytes
------------------------------------------------------------------------
r15468 | aldot | 2006-06-21 21:43:05 +0200 (Wed, 21 Jun 2006) | 19 lines
- remove useless global exports
function old new delta
rpm_main 940 1601 +661
rpm_getstring 107 112 +5
rpm_getint 148 153 +5
loop_through_files 103 106 +3
fileaction_dobackup 115 113 -2
fileaction_list 5 - -5
rpm_getcount 42 - -42
extract_cpio_gz 161 - -161
rpm_gettags 504 - -504
------------------------------------------------------------------------------
(add/remove: 0/4 grow/shrink: 4/1 up/down: 674/-714) Total: -40 bytes
text data bss dec hex filename
862322 10156 645892 1518370 172b22 busybox.old
862290 10156 645892 1518338 172b02 busybox
------------------------------------------------------------------------
r15555 | aldot | 2006-06-30 14:10:11 +0200 (Fri, 30 Jun 2006) | 22 lines
- shrink syslog a little bit, move a big buffer (for 'line') off the bss, fold s
emaphore stuff into single caller manually.
stats:
function old new delta
logMessage 395 427 +32
message 1245 1257 +12
opts - 4 +4
small 1 - -1
local_logging 4 - -4
doRemoteLog 4 - -4
circular_logging 4 - -4
syslogd_main 1299 1285 -14
static.res 36 16 -20
.rodata 186650 186586 -64
static.line 1025 - -1025
------------------------------------------------------------------------------
(add/remove: 1/5 grow/shrink: 2/3 up/down: 48/-1136) Total: -1088 bytes
cow@s37:~/src/busybox_scratch$ size sysklogd/syslogd.o{.orig,}
text data bss dec hex filename
3723 348 5242 9313 2461 sysklogd/syslogd.o.orig
3697 348 4188 8233 2029 sysklogd/syslogd.o
==============================================================================
Overall bloatcheck for the changeset mentioned above:
function old new delta
rpm_main 953 1608 +655
logMessage 395 427 +32
message 1245 1257 +12
opts - 4 +4
rpm_getstring 107 110 +3
rpm_getint 148 151 +3
loop_through_files 103 104 +1
small 1 - -1
fileaction_dobackup 115 113 -2
z_len 4 - -4
textend 4 - -4
part_nb 4 - -4
local_logging 4 - -4
insize 4 - -4
ifile_size 4 - -4
do_link 4 - -4
doRemoteLog 4 - -4
circular_logging 4 - -4
fileaction_list 5 - -5
new_text 70 60 -10
ipaddr_list_link 33 23 -10
clear_bufs 31 21 -10
syslogd_main 1287 1273 -14
builtin_help 190 176 -14
static.res 36 16 -20
builtin_source 229 199 -30
rpm_getcount 42 - -42
gzip_main 842 786 -56
.rodata 227176 227112 -64
lash_main 609 527 -82
busy_loop 3883 3739 -144
extract_cpio_gz 155 - -155
rpm_gettags 501 - -501
static.line 1025 - -1025
------------------------------------------------------------------------------
(add/remove: 1/15 grow/shrink: 6/12 up/down: 710/-2221) Total: -1511 bytes
2006-08-20 17:35:13 +00:00
|
|
|
xchdir("/");
|
2003-12-15 21:57:44 +00:00
|
|
|
|
2007-03-24 12:11:17 +00:00
|
|
|
if (!noclose) {
|
|
|
|
/* if "/dev/null" doesn't exist, bail out! */
|
|
|
|
fd = xopen(bb_dev_null, O_RDWR);
|
2003-12-15 21:57:44 +00:00
|
|
|
dup2(fd, STDIN_FILENO);
|
|
|
|
dup2(fd, STDOUT_FILENO);
|
|
|
|
dup2(fd, STDERR_FILENO);
|
2007-01-19 21:19:35 +00:00
|
|
|
while (fd > 2)
|
|
|
|
close(fd--);
|
2006-06-16 16:35:53 +00:00
|
|
|
}
|
2003-07-28 07:40:39 +00:00
|
|
|
|
2003-12-15 21:57:44 +00:00
|
|
|
switch (vfork()) {
|
|
|
|
case 0: /* child */
|
|
|
|
/* Make certain we are not a session leader, or else we
|
|
|
|
* might reacquire a controlling terminal */
|
|
|
|
if (vfork())
|
|
|
|
_exit(0);
|
2007-03-24 12:11:17 +00:00
|
|
|
/* High-order bit of first char in argv[0] is a hidden
|
|
|
|
* "we have (alrealy) re-execed, don't do it again" flag */
|
|
|
|
argv[0][0] |= 0x80;
|
|
|
|
execv(CONFIG_BUSYBOX_EXEC_PATH, argv);
|
|
|
|
bb_perror_msg_and_die("exec %s", CONFIG_BUSYBOX_EXEC_PATH);
|
2003-12-15 21:57:44 +00:00
|
|
|
case -1: /* error */
|
|
|
|
bb_perror_msg_and_die("vfork");
|
|
|
|
default: /* parent */
|
|
|
|
exit(0);
|
2004-03-15 08:29:22 +00:00
|
|
|
}
|
2003-07-28 07:40:39 +00:00
|
|
|
}
|
2006-05-31 10:19:51 +00:00
|
|
|
#endif /* BB_NOMMU */
|
2007-03-26 13:20:04 +00:00
|
|
|
|
|
|
|
#ifdef BB_NOMMU
|
2007-03-26 13:35:09 +00:00
|
|
|
void forkexit_or_rexec(char **argv)
|
2007-03-26 13:20:04 +00:00
|
|
|
{
|
|
|
|
pid_t pid;
|
|
|
|
/* Maybe we are already re-execed and come here again? */
|
|
|
|
if (re_execed)
|
|
|
|
return;
|
|
|
|
|
|
|
|
pid = vfork();
|
|
|
|
if (pid < 0) /* wtf? */
|
|
|
|
bb_perror_msg_and_die("vfork");
|
|
|
|
if (pid) /* parent */
|
|
|
|
exit(0);
|
|
|
|
/* child - re-exec ourself */
|
|
|
|
/* high-order bit of first char in argv[0] is a hidden
|
|
|
|
* "we have (alrealy) re-execed, don't do it again" flag */
|
|
|
|
argv[0][0] |= 0x80;
|
|
|
|
execv(CONFIG_BUSYBOX_EXEC_PATH, argv);
|
|
|
|
bb_perror_msg_and_die("exec %s", CONFIG_BUSYBOX_EXEC_PATH);
|
|
|
|
}
|
|
|
|
#else
|
2007-03-26 13:35:09 +00:00
|
|
|
/* Dance around (void)...*/
|
|
|
|
#undef forkexit_or_rexec
|
|
|
|
void forkexit_or_rexec(void)
|
2007-03-26 13:20:04 +00:00
|
|
|
{
|
|
|
|
pid_t pid;
|
|
|
|
pid = fork();
|
|
|
|
if (pid < 0) /* wtf? */
|
|
|
|
bb_perror_msg_and_die("fork");
|
|
|
|
if (pid) /* parent */
|
|
|
|
exit(0);
|
|
|
|
/* child */
|
|
|
|
}
|
2007-03-26 13:35:09 +00:00
|
|
|
#define forkexit_or_rexec(argv) forkexit_or_rexec()
|
2007-03-26 13:20:04 +00:00
|
|
|
#endif
|
|
|
|
|
|
|
|
|
|
|
|
/* Due to a #define in libbb.h on MMU systems we actually have 1 argument -
|
|
|
|
* char **argv "vanishes" */
|
|
|
|
void bb_daemonize_or_rexec(int flags, char **argv)
|
|
|
|
{
|
|
|
|
int fd;
|
|
|
|
|
|
|
|
fd = xopen(bb_dev_null, O_RDWR);
|
|
|
|
|
|
|
|
if (flags & DAEMON_CHDIR_ROOT)
|
|
|
|
xchdir("/");
|
|
|
|
|
|
|
|
if (flags & DAEMON_DEVNULL_STDIO) {
|
|
|
|
close(0);
|
|
|
|
close(1);
|
|
|
|
close(2);
|
|
|
|
}
|
|
|
|
|
|
|
|
while ((unsigned)fd < 2)
|
|
|
|
fd = dup(fd); /* have 0,1,2 open at least to /dev/null */
|
|
|
|
|
|
|
|
if (!(flags & DAEMON_ONLY_SANITIZE)) {
|
2007-03-26 13:35:09 +00:00
|
|
|
forkexit_or_rexec(argv);
|
2007-03-26 13:20:04 +00:00
|
|
|
/* if daemonizing, make sure we detach from stdio */
|
|
|
|
setsid();
|
|
|
|
dup2(fd, 0);
|
|
|
|
dup2(fd, 1);
|
|
|
|
dup2(fd, 2);
|
|
|
|
}
|
|
|
|
if (fd > 2)
|
|
|
|
close(fd--);
|
|
|
|
if (flags & DAEMON_CLOSE_EXTRA_FDS)
|
|
|
|
while (fd > 2)
|
|
|
|
close(fd--); /* close everything after fd#2 */
|
|
|
|
}
|
|
|
|
|
|
|
|
void bb_sanitize_stdio(void)
|
|
|
|
{
|
|
|
|
bb_daemonize_or_rexec(DAEMON_ONLY_SANITIZE, NULL);
|
|
|
|
}
|