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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2003-07-28 07:40:39 +00:00
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#include "libbb.h"
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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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// Be nice to nommu machines.
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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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/* Don't use BB_EXECVP tricks here! */
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execvp(argv[0], argv);
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/* We are (maybe) sharing a stack with blocked parent,
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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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failed = errno;
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_exit(0);
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}
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/* parent */
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/* Unfortunately, this is not reliable: vfork()
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* can be equivalent to fork() according to standards */
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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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{
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pid_t pid = spawn(argv);
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if (pid < 0) bb_perror_msg_and_die("%s", *argv);
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return pid;
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}
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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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if (daemon(nochdir, noclose))
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bb_perror_msg_and_die("daemon");
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}
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#endif
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#if 0 // def BB_NOMMU
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2007-03-24 12:11:17 +00:00
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void vfork_daemon_rexec(int nochdir, int noclose, char **argv)
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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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int fd;
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2004-03-15 08:29:22 +00:00
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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;
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2003-12-15 21:57:44 +00:00
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setsid();
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2004-03-15 08:29:22 +00:00
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2003-12-15 21:57:44 +00:00
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if (!nochdir)
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- 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
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xchdir("/");
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2003-12-15 21:57:44 +00:00
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2007-03-24 12:11:17 +00:00
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if (!noclose) {
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/* if "/dev/null" doesn't exist, bail out! */
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fd = xopen(bb_dev_null, O_RDWR);
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2003-12-15 21:57:44 +00:00
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dup2(fd, STDIN_FILENO);
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dup2(fd, STDOUT_FILENO);
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dup2(fd, STDERR_FILENO);
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2007-01-19 21:19:35 +00:00
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while (fd > 2)
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close(fd--);
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2006-06-16 16:35:53 +00:00
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}
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2003-07-28 07:40:39 +00:00
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2003-12-15 21:57:44 +00:00
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switch (vfork()) {
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case 0: /* child */
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/* Make certain we are not a session leader, or else we
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* might reacquire a controlling terminal */
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if (vfork())
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_exit(0);
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2007-03-24 12:11:17 +00:00
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/* High-order bit of first char in argv[0] is a hidden
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* "we have (alrealy) re-execed, don't do it again" flag */
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argv[0][0] |= 0x80;
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execv(CONFIG_BUSYBOX_EXEC_PATH, argv);
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bb_perror_msg_and_die("exec %s", CONFIG_BUSYBOX_EXEC_PATH);
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2003-12-15 21:57:44 +00:00
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case -1: /* error */
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bb_perror_msg_and_die("vfork");
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default: /* parent */
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exit(0);
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2004-03-15 08:29:22 +00:00
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}
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2003-07-28 07:40:39 +00:00
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}
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2006-05-31 10:19:51 +00:00
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#endif /* BB_NOMMU */
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2007-03-26 13:20:04 +00:00
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#ifdef BB_NOMMU
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2007-03-26 13:35:09 +00:00
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void forkexit_or_rexec(char **argv)
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2007-03-26 13:20:04 +00:00
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{
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pid_t pid;
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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;
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pid = vfork();
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if (pid < 0) /* wtf? */
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bb_perror_msg_and_die("vfork");
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if (pid) /* parent */
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exit(0);
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/* child - re-exec ourself */
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/* high-order bit of first char in argv[0] is a hidden
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* "we have (alrealy) re-execed, don't do it again" flag */
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argv[0][0] |= 0x80;
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execv(CONFIG_BUSYBOX_EXEC_PATH, argv);
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bb_perror_msg_and_die("exec %s", CONFIG_BUSYBOX_EXEC_PATH);
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}
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#else
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2007-03-26 13:35:09 +00:00
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/* Dance around (void)...*/
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#undef forkexit_or_rexec
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void forkexit_or_rexec(void)
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2007-03-26 13:20:04 +00:00
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{
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pid_t pid;
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pid = fork();
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if (pid < 0) /* wtf? */
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bb_perror_msg_and_die("fork");
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if (pid) /* parent */
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exit(0);
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/* child */
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}
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2007-03-26 13:35:09 +00:00
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#define forkexit_or_rexec(argv) forkexit_or_rexec()
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2007-03-26 13:20:04 +00:00
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#endif
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/* Due to a #define in libbb.h on MMU systems we actually have 1 argument -
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* char **argv "vanishes" */
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void bb_daemonize_or_rexec(int flags, char **argv)
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{
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int fd;
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fd = xopen(bb_dev_null, O_RDWR);
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if (flags & DAEMON_CHDIR_ROOT)
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xchdir("/");
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if (flags & DAEMON_DEVNULL_STDIO) {
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close(0);
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close(1);
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close(2);
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}
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while ((unsigned)fd < 2)
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fd = dup(fd); /* have 0,1,2 open at least to /dev/null */
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if (!(flags & DAEMON_ONLY_SANITIZE)) {
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2007-03-26 13:35:09 +00:00
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forkexit_or_rexec(argv);
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2007-03-26 13:20:04 +00:00
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/* if daemonizing, make sure we detach from stdio */
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setsid();
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dup2(fd, 0);
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dup2(fd, 1);
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dup2(fd, 2);
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}
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if (fd > 2)
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close(fd--);
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if (flags & DAEMON_CLOSE_EXTRA_FDS)
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while (fd > 2)
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close(fd--); /* close everything after fd#2 */
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}
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void bb_sanitize_stdio(void)
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{
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bb_daemonize_or_rexec(DAEMON_ONLY_SANITIZE, NULL);
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}
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