Diff of /trunk/mkinitrd-magellan/busybox/console-tools/openvt.c

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	revision 815 by niro, Sat Sep 1 22:45:15 2007 UTC	revision 816 by niro, Fri Apr 24 18:33:46 2009 UTC
#	Line 8	Line 8
8	* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.	* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
9	*/	*/
10
11	/* getopt not needed */	#include <linux/vt.h>
12		#include "libbb.h"
13
14	#include "busybox.h"	/* "Standard" openvt's man page (we do not support all of this):
15
16	int openvt_main(int argc, char **argv)	openvt [-c NUM] [-fsulv] [--] [command [args]]
17
18		Find the first available VT, and run command on it. Stdio is directed
19		to that VT. If no command is specified then $SHELL is used.
20
21		-c NUM
22		Use the given VT number, not the first free one.
23		-f
24		Force opening a VT: don't try to check if VT is already in use.
25		-s
26		Switch to the new VT when starting the command.
27		The VT of the new command will be made the new current VT.
28		-u
29		Figure out the owner of the current VT, and run login as that user.
30		Suitable to be called by init. Shouldn't be used with -c or -l.
31		-l
32		Make the command a login shell: a "-" is prepended to the argv[0]
33		when command is executed.
34		-v
35		Verbose.
36		-w
37		Wait for command to complete. If -w and -s are used together,
38		switch back to the controlling terminal when the command completes.
39
40		bbox:
41		-u: not implemented
42		-f: always in effect
43		-l: not implemented, ignored
44		-v: ignored
45		-ws: does NOT switch back
46		*/
47
48		/* Helper: does this fd understand VT_xxx? */
49		static int not_vt_fd(int fd)
50		{
51		struct vt_stat vtstat;
52		return ioctl(fd, VT_GETSTATE, &vtstat); /* !0: error, it's not VT fd */
53		}
54
55		/* Helper: get a fd suitable for VT_xxx */
56		static int get_vt_fd(void)
57	{	{
58	int fd;	int fd;
	char vtname[sizeof(VC_FORMAT) + 2];
59
60	if (argc < 3) {	/* Do we, by chance, already have it? */
61	bb_show_usage();	for (fd = 0; fd < 3; fd++)
62		if (!not_vt_fd(fd))
63		return fd;
64		/* _only_ O_NONBLOCK: ask for neither read nor write perms */
65		/*FIXME: use? device_open(DEV_CONSOLE,0); */
66		fd = open(DEV_CONSOLE, O_NONBLOCK);
67		if (fd >= 0 && !not_vt_fd(fd))
68		return fd;
69		bb_error_msg_and_die("can't find open VT");
70		}
71
72		static int find_free_vtno(void)
73		{
74		int vtno;
75		int fd = get_vt_fd();
76
77		errno = 0;
78		/*xfunc_error_retval = 3; - do we need compat? */
79		if (ioctl(fd, VT_OPENQRY, &vtno) != 0 || vtno <= 0)
80		bb_perror_msg_and_die("can't find open VT");
81		// Not really needed, grep for DAEMON_ONLY_SANITIZE
82		// if (fd > 2)
83		// close(fd);
84		return vtno;
85		}
86
87		/* vfork scares gcc, it generates bigger code.
88		* Keep it away from main program.
89		* TODO: move to libbb; or adapt existing libbb's spawn().
90		*/
91		static NOINLINE void vfork_child(char **argv)
92		{
93		if (vfork() == 0) {
94		/* CHILD */
95		/* Try to make this VT our controlling tty */
96		setsid(); /* lose old ctty */
97		ioctl(STDIN_FILENO, TIOCSCTTY, 0 /* 0: don't forcibly steal */);
98		//bb_error_msg("our sid %d", getsid(0));
99		//bb_error_msg("our pgrp %d", getpgrp());
100		//bb_error_msg("VT's sid %d", tcgetsid(0));
101		//bb_error_msg("VT's pgrp %d", tcgetpgrp(0));
102		BB_EXECVP(argv[0], argv);
103		bb_perror_msg_and_die("exec %s", argv[0]);
104		}
105		}
106
107		int openvt_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
108		int openvt_main(int argc UNUSED_PARAM, char **argv)
109		{
110		char vtname[sizeof(VC_FORMAT) + sizeof(int)*3];
111		struct vt_stat vtstat;
112		char *str_c;
113		int vtno;
114		int flags;
115		enum {
116		OPT_c = (1 << 0),
117		OPT_w = (1 << 1),
118		OPT_s = (1 << 2),
119		OPT_l = (1 << 3),
120		OPT_f = (1 << 4),
121		OPT_v = (1 << 5),
122		};
123
124		/* "+" - stop on first non-option */
125		flags = getopt32(argv, "+c:wslfv", &str_c);
126		argv += optind;
127
128		if (flags & OPT_c) {
129		/* Check for illegal vt number: < 1 or > 63 */
130		vtno = xatou_range(str_c, 1, 63);
131		} else {
132		vtno = find_free_vtno();
133		}
134
135		/* Grab new VT */
136		sprintf(vtname, VC_FORMAT, vtno);
137		/* (Try to) clean up stray open fds above fd 2 */
138		bb_daemonize_or_rexec(DAEMON_CLOSE_EXTRA_FDS | DAEMON_ONLY_SANITIZE, NULL);
139		close(STDIN_FILENO);
140		/*setsid(); - BAD IDEA: after we exit, child is SIGHUPed... */
141		xopen(vtname, O_RDWR);
142		xioctl(STDIN_FILENO, VT_GETSTATE, &vtstat);
143
144		if (flags & OPT_s) {
145		console_make_active(STDIN_FILENO, vtno);
146		}
147
148		if (!argv[0]) {
149		argv--;
150		argv[0] = getenv("SHELL");
151		if (!argv[0])
152		argv[0] = (char *) DEFAULT_SHELL;
153		/*argv[1] = NULL; - already is */
154	}	}
	/* check for illegal vt number: < 1 or > 63 */
	sprintf(vtname, VC_FORMAT, (int)xatoul_range(argv[1], 1, 63));
155
156	if (fork() == 0) {	xdup2(STDIN_FILENO, STDOUT_FILENO);
157	/* child */	xdup2(STDIN_FILENO, STDERR_FILENO);
158	/* leave current vt (controlling tty) */
159	setsid();	#ifdef BLOAT
160	/* and grab new one */	{
161	fd = xopen(vtname, O_RDWR);	/* Handle -l (login shell) option */
162	/* Reassign stdin, stdout and sterr */	const char *prog = argv[0];
163	dup2(fd, STDIN_FILENO);	if (flags & OPT_l)
164	dup2(fd, STDOUT_FILENO);	argv[0] = xasprintf("-%s", argv[0]);
165	dup2(fd, STDERR_FILENO);	}
166	while (fd > 2) close(fd--);	#endif
167
168	execvp(argv[2], &argv[2]);	vfork_child(argv);
169	_exit(1);	if (flags & OPT_w) {
170		/* We have only one child, wait for it */
171		safe_waitpid(-1, NULL, 0); /* loops on EINTR */
172		if (flags & OPT_s) {
173		console_make_active(STDIN_FILENO, vtstat.v_active);
174		// Compat: even with -c N (try to) disallocate:
175		// # /usr/app/kbd-1.12/bin/openvt -f -c 9 -ws sleep 5
176		// openvt: could not deallocate console 9
177		xioctl(STDIN_FILENO, VT_DISALLOCATE, (void*)(ptrdiff_t)vtno);
178		}
179	}	}
180	return EXIT_SUCCESS;	return EXIT_SUCCESS;
181	}	}

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