Adding upstream version 2.33.1.upstream/2.33.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 828 insertions, 0 deletions

diff --git a/login-utils/sulogin-consoles.c b/login-utils/sulogin-consoles.c
new file mode 100644
index 0000000..2c0eed3
--- /dev/null
+++ b/login-utils/sulogin-consoles.c
@@ -0,0 +1,828 @@
+/*
+ * consoles.c	    Routines to detect the system consoles
+ *
+ * Copyright (c) 2011 SuSE LINUX Products GmbH, All rights reserved.
+ * Copyright (C) 2012 Karel Zak <kzak@redhat.com>
+ * Copyright (C) 2012 Werner Fink <werner@suse.de>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program (see the file COPYING); if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ *
+ * Author: Werner Fink <werner@suse.de>
+ */
+
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#ifdef __linux__
+# include <sys/vt.h>
+# include <sys/kd.h>
+# include <linux/serial.h>
+# include <linux/major.h>
+#endif
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#ifdef USE_SULOGIN_EMERGENCY_MOUNT
+# include <sys/mount.h>
+# include <linux/fs.h>
+# include <linux/magic.h>
+# ifndef MNT_DETACH
+#  define MNT_DETACH   2
+# endif
+#endif
+
+#include "c.h"
+#include "canonicalize.h"
+#include "sulogin-consoles.h"
+
+#if !defined(__STDC_VERSION__) || (__STDC_VERSION__ < 199901L)
+# ifndef  typeof
+#  define typeof		__typeof__
+# endif
+# ifndef  restrict
+#  define restrict		__restrict__
+# endif
+#endif
+
+#define alignof(type)		((sizeof(type)+(sizeof(void*)-1)) & ~(sizeof(void*)-1))
+#define strsize(string)		(strlen((string))+1)
+
+static int consoles_debug;
+#define DBG(x)	do { \
+			if (consoles_debug) { \
+				fputs("consoles debug: ", stderr); \
+				x;			     \
+			} \
+		} while (0)
+
+static inline void __attribute__ ((__format__ (__printf__, 1, 2)))
+dbgprint(const char * const mesg, ...)
+{
+	va_list ap;
+	va_start(ap, mesg);
+	vfprintf(stderr, mesg, ap);
+	va_end(ap);
+	fputc('\n', stderr);
+}
+
+#ifdef USE_SULOGIN_EMERGENCY_MOUNT
+/*
+ * Make C library standard calls such like ttyname(3) work
+ * even if the system does not show any of the standard
+ * directories.
+ */
+
+static uint32_t emergency_flags;
+# define MNT_PROCFS    0x0001
+# define MNT_DEVTMPFS  0x0002
+
+void emergency_do_umounts(void)
+{
+	if (emergency_flags & MNT_DEVTMPFS)
+		umount2("/dev", MNT_DETACH);
+	if (emergency_flags & MNT_PROCFS)
+		umount2("/proc", MNT_DETACH);
+}
+
+void emergency_do_mounts(void)
+{
+	struct stat rt, xt;
+
+	if (emergency_flags) {
+		emergency_flags = 0;
+		return;
+	}
+
+	if (stat("/", &rt) != 0) {
+		warn("cannot get file status of root file system\n");
+		return;
+	}
+
+	if (stat("/proc", &xt) == 0
+	    && rt.st_dev == xt.st_dev
+	    && mount("proc", "/proc", "proc", MS_RELATIME, NULL) == 0)
+		emergency_flags |= MNT_PROCFS;
+
+	if (stat("/dev", &xt) == 0
+	    && rt.st_dev == xt.st_dev
+	    && mount("devtmpfs", "/dev", "devtmpfs",
+		     MS_RELATIME, "mode=0755,nr_inodes=0") == 0) {
+
+		emergency_flags |= MNT_DEVTMPFS;
+		mknod("/dev/console", S_IFCHR|S_IRUSR|S_IWUSR,
+					makedev(TTYAUX_MAJOR, 1));
+
+		if (symlink("/proc/self/fd", "/dev/fd") == 0) {
+			ignore_result( symlink("fd/0", "/dev/stdin") );
+			ignore_result( symlink("fd/1", "/dev/stdout") );
+			ignore_result( symlink("fd/2", "/dev/stderr") );
+		}
+	}
+}
+
+#else /* !USE_SULOGIN_EMERGENCY_MOUNT */
+
+void emergency_do_umounts(void) { }
+void emergency_do_mounts(void) { }
+
+#endif /* USE_SULOGIN_EMERGENCY_MOUNT */
+
+/*
+ * Read and allocate one line from file,
+ * the caller has to free the result
+ */
+static __attribute__((__nonnull__))
+char *oneline(const char * const file)
+{
+	FILE *fp;
+	char *ret = NULL;
+	size_t dummy = 0;
+	ssize_t len;
+
+	DBG(dbgprint("reading %s", file));
+
+	if (!(fp = fopen(file, "r" UL_CLOEXECSTR)))
+		return NULL;
+	len = getline(&ret, &dummy, fp);
+	if (len >= 0) {
+		char *nl;
+
+		if (len)
+			ret[len-1] = '\0';
+		if ((nl = strchr(ret, '\n')))
+			*nl = '\0';
+	}
+
+	fclose(fp);
+	return ret;
+}
+
+#ifdef __linux__
+/*
+ *  Read and determine active attribute for tty below
+ *  /sys/class/tty, the caller has to free the result.
+ */
+static __attribute__((__malloc__))
+char *actattr(const char * const tty)
+{
+	char *ret, *path;
+
+	if (!tty || !*tty)
+		return NULL;
+	if (asprintf(&path, "/sys/class/tty/%s/active", tty) < 0)
+		return NULL;
+
+	ret = oneline(path);
+	free(path);
+	return ret;
+}
+
+/*
+ * Read and determine device attribute for tty below
+ * /sys/class/tty.
+ */
+static
+dev_t devattr(const char * const tty)
+{
+	dev_t dev = 0;
+	char *path, *value;
+
+	if (!tty || !*tty)
+		return 0;
+	if (asprintf(&path, "/sys/class/tty/%s/dev", tty) < 0)
+		return 0;
+
+	value = oneline(path);
+	if (value) {
+		unsigned int maj, min;
+
+		if (sscanf(value, "%u:%u", &maj, &min) == 2)
+			dev = makedev(maj, min);
+		free(value);
+	}
+
+	free(path);
+	return dev;
+}
+#endif /* __linux__ */
+
+/*
+ * Search below /dev for the character device in `dev_t comparedev' variable.
+ * Note that realpath(3) is used here to avoid not existent devices due the
+ * strdup(3) used in our canonicalize_path()!
+ */
+static
+#ifdef __GNUC__
+__attribute__((__nonnull__,__malloc__,__hot__))
+#endif
+char* scandev(DIR *dir, const dev_t comparedev)
+{
+	char path[PATH_MAX];
+	char *name = NULL;
+	const struct dirent *dent;
+	int len, fd;
+
+	DBG(dbgprint("scanning /dev for %u:%u", major(comparedev), minor(comparedev)));
+
+	/*
+	 * Try udev links on character devices first.
+	 */
+	if ((len = snprintf(path, sizeof(path),
+			    "/dev/char/%u:%u", major(comparedev), minor(comparedev))) > 0 &&
+	    (size_t)len < sizeof(path)) {
+
+	    name = realpath(path, NULL);
+	    if (name)
+		    goto out;
+	}
+
+	fd = dirfd(dir);
+	rewinddir(dir);
+	while ((dent = readdir(dir))) {
+		struct stat st;
+
+#ifdef _DIRENT_HAVE_D_TYPE
+		if (dent->d_type != DT_UNKNOWN && dent->d_type != DT_CHR)
+			continue;
+#endif
+		if (fstatat(fd, dent->d_name, &st, 0) < 0)
+			continue;
+		if (!S_ISCHR(st.st_mode))
+			continue;
+		if (comparedev != st.st_rdev)
+			continue;
+		if ((len = snprintf(path, sizeof(path), "/dev/%s", dent->d_name)) < 0 ||
+		    (size_t)len >= sizeof(path))
+			continue;
+
+		name = realpath(path, NULL);
+		if (name)
+			goto out;
+	}
+
+#ifdef USE_SULOGIN_EMERGENCY_MOUNT
+	/*
+	 * There was no /dev mounted hence and no device was found hence we create our own.
+	 */
+	if (!name && (emergency_flags & MNT_DEVTMPFS)) {
+
+		if ((len = snprintf(path, sizeof(path),
+				    "/dev/tmp-%u:%u", major(comparedev), minor(comparedev))) < 0 ||
+		    (size_t)len >= sizeof(path))
+			goto out;
+
+		if (mknod(path, S_IFCHR|S_IRUSR|S_IWUSR, comparedev) < 0 && errno != EEXIST)
+			goto out;
+
+		name = realpath(path, NULL);
+	}
+#endif
+out:
+	return name;
+}
+
+/*
+ * Default control characters for an unknown terminal line.
+ */
+
+/*
+ * Allocate an aligned `struct console' memory area,
+ * initialize its default values, and append it to
+ * the global linked list.
+ */
+static
+#ifdef __GNUC__
+__attribute__((__hot__))
+#endif
+int append_console(struct list_head *consoles, const char * const name)
+{
+	struct console *restrict tail;
+	const struct console *last = NULL;
+
+	DBG(dbgprint("appenging %s", name));
+
+	if (!list_empty(consoles))
+		last = list_last_entry(consoles, struct console, entry);
+
+	if (posix_memalign((void *) &tail, sizeof(void *),
+			   alignof(struct console) + strsize(name)) != 0)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&tail->entry);
+	INIT_CHARDATA(&tail->cp);
+
+	list_add_tail(&tail->entry, consoles);
+	tail->tty = ((char *) tail) + alignof(struct console);
+	strcpy(tail->tty, name);
+
+	tail->file = (FILE*)0;
+	tail->flags = 0;
+	tail->fd = -1;
+	tail->id = last ? last->id + 1 : 0;
+	tail->pid = -1;
+	memset(&tail->tio, 0, sizeof(tail->tio));
+
+	return 0;
+}
+
+#ifdef __linux__
+/*
+ * return codes:
+ *	< 0	- fatal error (no mem or so... )
+ *	  0	- success
+ *	  1	- recoverable error
+ *	  2	- detection not available
+ */
+static int detect_consoles_from_proc(struct list_head *consoles)
+{
+	char fbuf[16 + 1];
+	DIR *dir = NULL;
+	FILE *fc = NULL;
+	int maj, min, rc = 1, matches;
+
+	DBG(dbgprint("trying /proc"));
+
+	fc = fopen("/proc/consoles", "r" UL_CLOEXECSTR);
+	if (!fc) {
+		rc = 2;
+		goto done;
+	}
+	dir = opendir("/dev");
+	if (!dir)
+		goto done;
+
+	while ((matches = fscanf(fc, "%*s %*s (%16[^)]) %d:%d", fbuf, &maj, &min)) >= 1) {
+		char *name;
+		dev_t comparedev;
+
+		if (matches != 3)
+			continue;
+		if (!strchr(fbuf, 'E'))
+			continue;
+		comparedev = makedev(maj, min);
+		name = scandev(dir, comparedev);
+		if (!name)
+			continue;
+		rc = append_console(consoles, name);
+		free(name);
+		if (rc < 0)
+			goto done;
+	}
+
+	rc = list_empty(consoles) ? 1 : 0;
+done:
+	if (dir)
+		closedir(dir);
+	if (fc)
+		fclose(fc);
+	DBG(dbgprint("[/proc rc=%d]", rc));
+	return rc;
+}
+
+/*
+ * return codes:
+ *	< 0	- fatal error (no mem or so... )
+ *	  0	- success
+ *	  1	- recoverable error
+ *	  2	- detection not available
+ */
+static int detect_consoles_from_sysfs(struct list_head *consoles)
+{
+	char *attrib = NULL, *words, *token;
+	DIR *dir = NULL;
+	int rc = 1;
+
+	DBG(dbgprint("trying /sys"));
+
+	attrib = actattr("console");
+	if (!attrib) {
+		rc = 2;
+		goto done;
+	}
+
+	words = attrib;
+
+	dir = opendir("/dev");
+	if (!dir)
+		goto done;
+
+	while ((token = strsep(&words, " \t\r\n"))) {
+		char *name;
+		dev_t comparedev;
+
+		if (*token == '\0')
+			continue;
+
+		comparedev = devattr(token);
+		if (comparedev == makedev(TTY_MAJOR, 0)) {
+			char *tmp = actattr(token);
+			if (!tmp)
+				continue;
+			comparedev = devattr(tmp);
+			free(tmp);
+		}
+
+		name = scandev(dir, comparedev);
+		if (!name)
+			continue;
+		rc = append_console(consoles, name);
+		free(name);
+		if (rc < 0)
+			goto done;
+	}
+
+	rc = list_empty(consoles) ? 1 : 0;
+done:
+	free(attrib);
+	if (dir)
+		closedir(dir);
+	DBG(dbgprint("[/sys rc=%d]", rc));
+	return rc;
+}
+
+
+static int detect_consoles_from_cmdline(struct list_head *consoles)
+{
+	char *cmdline, *words, *token;
+	dev_t comparedev;
+	DIR *dir = NULL;
+	int rc = 1, fd;
+
+	DBG(dbgprint("trying kernel cmdline"));
+
+	cmdline = oneline("/proc/cmdline");
+	if (!cmdline) {
+		rc = 2;
+		goto done;
+	}
+
+	words= cmdline;
+	dir = opendir("/dev");
+	if (!dir)
+		goto done;
+
+	while ((token = strsep(&words, " \t\r\n"))) {
+#ifdef TIOCGDEV
+		unsigned int devnum;
+#else
+		struct vt_stat vt;
+		struct stat st;
+#endif
+		char *colon, *name;
+
+		if (*token != 'c')
+			continue;
+		if (strncmp(token, "console=", 8) != 0)
+			continue;
+		token += 8;
+
+		if (strcmp(token, "brl") == 0)
+			token += 4;
+		if ((colon = strchr(token, ',')))
+			*colon = '\0';
+
+		if (asprintf(&name, "/dev/%s", token) < 0)
+			continue;
+		if ((fd = open(name, O_RDWR|O_NONBLOCK|O_NOCTTY|O_CLOEXEC)) < 0) {
+			free(name);
+			continue;
+		}
+		free(name);
+#ifdef TIOCGDEV
+		if (ioctl (fd, TIOCGDEV, &devnum) < 0) {
+			close(fd);
+			continue;
+		}
+		comparedev = (dev_t) devnum;
+#else
+		if (fstat(fd, &st) < 0) {
+			close(fd);
+			continue;
+		}
+		comparedev = st.st_rdev;
+		if (comparedev == makedev(TTY_MAJOR, 0)) {
+			if (ioctl(fd, VT_GETSTATE, &vt) < 0) {
+				close(fd);
+				continue;
+			}
+			comparedev = makedev(TTY_MAJOR, (int)vt.v_active);
+		}
+#endif
+		close(fd);
+
+		name = scandev(dir, comparedev);
+		if (!name)
+			continue;
+		rc = append_console(consoles, name);
+		free(name);
+		if (rc < 0)
+			goto done;
+	}
+
+	rc = list_empty(consoles) ? 1 : 0;
+done:
+	if (dir)
+		closedir(dir);
+	free(cmdline);
+	DBG(dbgprint("[kernel cmdline rc=%d]", rc));
+	return rc;
+}
+
+#ifdef TIOCGDEV
+static int detect_consoles_from_tiocgdev(struct list_head *consoles,
+					const int fallback,
+					const char *device)
+{
+	unsigned int devnum;
+	char *name;
+	int rc = 1, fd = -1;
+	dev_t comparedev;
+	DIR *dir = NULL;
+	struct console *console;
+
+	DBG(dbgprint("trying tiocgdev"));
+
+	if (!device || !*device)
+		fd = dup(fallback);
+	else
+		fd = open(device, O_RDWR|O_NONBLOCK|O_NOCTTY|O_CLOEXEC);
+
+	if (fd < 0)
+		goto done;
+	if (ioctl (fd, TIOCGDEV, &devnum) < 0)
+		goto done;
+
+	comparedev = (dev_t) devnum;
+	dir = opendir("/dev");
+	if (!dir)
+		goto done;
+
+	name = scandev(dir, comparedev);
+	closedir(dir);
+
+	if (!name) {
+		name = (char *) (device && *device ? device : ttyname(fallback));
+		if (!name)
+			name = "/dev/tty1";
+
+		name = strdup(name);
+		if (!name) {
+			rc = -ENOMEM;
+			goto done;
+		}
+	}
+	rc = append_console(consoles, name);
+	free(name);
+	if (rc < 0)
+		goto done;
+	if (list_empty(consoles)) {
+		rc = 1;
+		goto done;
+	}
+	console = list_last_entry(consoles, struct console, entry);
+	if (console &&  (!device || !*device))
+		console->fd = fallback;
+done:
+	if (fd >= 0)
+		close(fd);
+	DBG(dbgprint("[tiocgdev rc=%d]", rc));
+	return rc;
+}
+#endif /* TIOCGDEV */
+#endif /* __linux__ */
+
+/*
+ * Try to detect the real device(s) used for the system console
+ * /dev/console if but only if /dev/console is used.  On Linux
+ * this can be more than one device, e.g. a serial line as well
+ * as a virtual console as well as a simple printer.
+ *
+ * Returns 1 if stdout and stderr should be reconnected and 0
+ * otherwise or less than zero on error.
+ */
+int detect_consoles(const char *device, const int fallback, struct list_head *consoles)
+{
+	int fd, reconnect = 0, rc;
+	dev_t comparedev = 0;
+
+	consoles_debug = getenv("CONSOLES_DEBUG") ? 1 : 0;
+
+	if (!device || !*device)
+		fd = fallback >= 0 ? dup(fallback) : - 1;
+	else {
+		fd = open(device, O_RDWR|O_NONBLOCK|O_NOCTTY|O_CLOEXEC);
+		reconnect = 1;
+	}
+
+	DBG(dbgprint("detection started [device=%s, fallback=%d]",
+				device, fallback));
+
+	if (fd >= 0) {
+		DIR *dir;
+		char *name;
+		struct stat st;
+#ifdef TIOCGDEV
+		unsigned int devnum;
+#endif
+#ifdef __GNU__
+		/*
+		 * The Hurd always gives st_rdev as 0, which causes this
+		 * method to select the first terminal it finds.
+		 */
+		close(fd);
+		goto fallback;
+#endif
+		DBG(dbgprint("trying device/fallback file descriptor"));
+
+		if (fstat(fd, &st) < 0) {
+			close(fd);
+			goto fallback;
+		}
+		comparedev = st.st_rdev;
+
+		if (reconnect &&
+		    (fstat(fallback, &st) < 0 || comparedev != st.st_rdev))
+			dup2(fd, fallback);
+#ifdef __linux__
+		/*
+		 * Check if the device detection for Linux system console should be used.
+		 */
+		if (comparedev == makedev(TTYAUX_MAJOR, 0)) {	/* /dev/tty	*/
+			close(fd);
+			device = "/dev/tty";
+			goto fallback;
+		}
+		if (comparedev == makedev(TTYAUX_MAJOR, 1)) {	/* /dev/console */
+			close(fd);
+			goto console;
+		}
+		if (comparedev == makedev(TTYAUX_MAJOR, 2)) {	/* /dev/ptmx	*/
+			close(fd);
+			device = "/dev/tty";
+			goto fallback;
+		}
+		if (comparedev == makedev(TTY_MAJOR, 0)) {	/* /dev/tty0	*/
+			struct vt_stat vt;
+			if (ioctl(fd, VT_GETSTATE, &vt) < 0) {
+				close(fd);
+				goto fallback;
+			}
+			comparedev = makedev(TTY_MAJOR, (int)vt.v_active);
+		}
+#endif
+#ifdef TIOCGDEV
+		if (ioctl (fd, TIOCGDEV, &devnum) < 0) {
+			close(fd);
+			goto fallback;
+		}
+		comparedev = (dev_t)devnum;
+#endif
+		close(fd);
+		dir = opendir("/dev");
+		if (!dir)
+			goto fallback;
+		name = scandev(dir, comparedev);
+		closedir(dir);
+
+		if (name) {
+			rc = append_console(consoles, name);
+			free(name);
+			if (rc < 0)
+				return rc;
+		}
+		if (list_empty(consoles))
+			goto fallback;
+
+		DBG(dbgprint("detection success [rc=%d]", reconnect));
+		return reconnect;
+	}
+#ifdef __linux__
+console:
+	/*
+	 * Detection of devices used for Linux system console using
+	 * the /proc/consoles API with kernel 2.6.38 and higher.
+	 */
+	rc = detect_consoles_from_proc(consoles);
+	if (rc == 0)
+		return reconnect;	/* success */
+	if (rc < 0)
+		return rc;		/* fatal error */
+
+	/*
+	 * Detection of devices used for Linux system console using
+	 * the sysfs /sys/class/tty/ API with kernel 2.6.37 and higher.
+	 */
+	rc = detect_consoles_from_sysfs(consoles);
+	if (rc == 0)
+		return reconnect;	/* success */
+	if (rc < 0)
+		return rc;		/* fatal error */
+
+	/*
+	 * Detection of devices used for Linux system console using
+	 * kernel parameter on the kernels command line.
+	 */
+	rc = detect_consoles_from_cmdline(consoles);
+	if (rc == 0)
+		return reconnect;	/* success */
+	if (rc < 0)
+		return rc;		/* fatal error */
+
+	/*
+	 * Detection of the device used for Linux system console using
+	 * the ioctl TIOCGDEV if available (e.g. official 2.6.38).
+	 */
+#ifdef TIOCGDEV
+	rc = detect_consoles_from_tiocgdev(consoles, fallback, device);
+	if (rc == 0)
+		return reconnect;	/* success */
+	if (rc < 0)
+		return rc;		/* fatal error */
+#endif
+	if (!list_empty(consoles)) {
+		DBG(dbgprint("detection success [rc=%d]", reconnect));
+		return reconnect;
+	}
+
+#endif /* __linux __ */
+
+fallback:
+	if (fallback >= 0) {
+		const char *name;
+	        char *n;
+		struct console *console;
+
+		if (device && *device != '\0')
+			name = device;
+		else	name = ttyname(fallback);
+
+		if (!name)
+			name = "/dev/tty";
+
+		n = strdup(name);
+		if (!n)
+			return -ENOMEM;
+		rc = append_console(consoles, n);
+		free(n);
+		if (rc < 0)
+			return rc;
+		if (list_empty(consoles))
+			return 1;
+		console = list_last_entry(consoles, struct console, entry);
+		if (console)
+			console->fd = fallback;
+	}
+
+	DBG(dbgprint("detection done by fallback [rc=%d]", reconnect));
+	return reconnect;
+}
+
+
+#ifdef TEST_PROGRAM
+int main(int argc, char *argv[])
+{
+	char *name = NULL;
+	int fd, re;
+	struct list_head *p, consoles;
+
+	if (argc == 2) {
+		name = argv[1];
+		fd = open(name, O_RDWR);
+	} else {
+		name = ttyname(STDIN_FILENO);
+		fd = STDIN_FILENO;
+	}
+
+	if (!name)
+		errx(EXIT_FAILURE, "usage: %s [<tty>]\n", program_invocation_short_name);
+
+	INIT_LIST_HEAD(&consoles);
+	re = detect_consoles(name, fd, &consoles);
+
+	list_for_each(p, &consoles) {
+		struct console *c = list_entry(p, struct console, entry);
+		printf("%s: id=%d %s\n", c->tty, c->id, re ? "(reconnect) " : "");
+	}
+
+	return 0;
+}
+#endif