merge device event handling and make database content available on "remove"

1 files changed, 307 insertions, 0 deletions

diff --git a/udev_node.c b/udev_node.c
new file mode 100644
index 0000000000..9d6e89cfa1
--- /dev/null
+++ b/udev_node.c
@@ -0,0 +1,307 @@
+/*
+ * udev-node.c - device node handling
+ *
+ * Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
+ * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
+ *
+ *	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 version 2 of the License.
+ * 
+ *	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; if not, write to the Free Software Foundation, Inc.,
+ *	675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <stddef.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+#include <grp.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#include "udev.h"
+#include "udev_rules.h"
+#include "udev_selinux.h"
+
+
+int udev_node_mknod(struct udevice *udev, const char *file, dev_t devt, mode_t mode, uid_t uid, gid_t gid)
+{
+	struct stat stats;
+	int retval = 0;
+
+	if (major(devt) != 0 && strcmp(udev->dev->subsystem, "block") == 0)
+		mode |= S_IFBLK;
+	else
+		mode |= S_IFCHR;
+
+	if (stat(file, &stats) != 0)
+		goto create;
+
+	/* preserve node with already correct numbers, to prevent changing the inode number */
+	if ((stats.st_mode & S_IFMT) == (mode & S_IFMT) && (stats.st_rdev == devt)) {
+		info("preserve file '%s', because it has correct dev_t", file);
+		selinux_setfilecon(file, udev->dev->kernel_name, stats.st_mode);
+		goto perms;
+	}
+
+	if (unlink(file) != 0)
+		err("unlink(%s) failed: %s", file, strerror(errno));
+	else
+		dbg("already present file '%s' unlinked", file);
+
+create:
+	selinux_setfscreatecon(file, udev->dev->kernel_name, mode);
+	retval = mknod(file, mode, devt);
+	selinux_resetfscreatecon();
+	if (retval != 0) {
+		err("mknod(%s, %#o, %u, %u) failed: %s",
+		    file, mode, major(devt), minor(devt), strerror(errno));
+		goto exit;
+	}
+
+perms:
+	dbg("chmod(%s, %#o)", file, mode);
+	if (chmod(file, mode) != 0) {
+		err("chmod(%s, %#o) failed: %s", file, mode, strerror(errno));
+		goto exit;
+	}
+
+	if (uid != 0 || gid != 0) {
+		dbg("chown(%s, %u, %u)", file, uid, gid);
+		if (chown(file, uid, gid) != 0) {
+			err("chown(%s, %u, %u) failed: %s",
+			    file, uid, gid, strerror(errno));
+			goto exit;
+		}
+	}
+
+exit:
+	return retval;
+}
+
+int udev_node_add(struct udevice *udev)
+{
+	char filename[PATH_SIZE];
+	struct name_entry *name_loop;
+	uid_t uid;
+	gid_t gid;
+	int tail;
+	int i;
+	int retval = 0;
+
+	selinux_init();
+
+	snprintf(filename, sizeof(filename), "%s/%s", udev_root, udev->name);
+	filename[sizeof(filename)-1] = '\0';
+
+	/* create parent directories if needed */
+	if (strchr(udev->name, '/'))
+		create_path(filename);
+
+	if (strcmp(udev->owner, "root") == 0)
+		uid = 0;
+	else {
+		char *endptr;
+		unsigned long id;
+
+		id = strtoul(udev->owner, &endptr, 10);
+		if (endptr[0] == '\0')
+			uid = (uid_t) id;
+		else
+			uid = lookup_user(udev->owner);
+	}
+
+	if (strcmp(udev->group, "root") == 0)
+		gid = 0;
+	else {
+		char *endptr;
+		unsigned long id;
+
+		id = strtoul(udev->group, &endptr, 10);
+		if (endptr[0] == '\0')
+			gid = (gid_t) id;
+		else
+			gid = lookup_group(udev->group);
+	}
+
+	info("creating device node '%s', major = '%d', minor = '%d', " "mode = '%#o', uid = '%d', gid = '%d'",
+	     filename, major(udev->devt), minor(udev->devt), udev->mode, uid, gid);
+
+	if (!udev->test_run)
+		if (udev_node_mknod(udev, filename, udev->devt, udev->mode, uid, gid) != 0) {
+			retval = -1;
+			goto exit;
+		}
+
+	setenv("DEVNAME", filename, 1);
+
+	/* create all_partitions if requested */
+	if (udev->partitions) {
+		char partitionname[PATH_SIZE];
+		char *attr;
+		int range;
+
+		/* take the maximum registered minor range */
+		attr = sysfs_attr_get_value(udev->dev->devpath, "range");
+		if (attr) {
+			range = atoi(attr);
+			if (range > 1)
+				udev->partitions = range-1;
+		}
+		info("creating device partition nodes '%s[1-%i]'", filename, udev->partitions);
+		if (!udev->test_run) {
+			for (i = 1; i <= udev->partitions; i++) {
+				dev_t part_devt;
+
+				snprintf(partitionname, sizeof(partitionname), "%s%d", filename, i);
+				partitionname[sizeof(partitionname)-1] = '\0';
+				part_devt = makedev(major(udev->devt), minor(udev->devt) + i);
+				udev_node_mknod(udev, partitionname, part_devt, udev->mode, uid, gid);
+			}
+		}
+	}
+
+	/* create symlink(s) if requested */
+	if (!list_empty(&udev->symlink_list)) {
+		char symlinks[512] = "";
+
+		list_for_each_entry(name_loop, &udev->symlink_list, node) {
+			char linktarget[PATH_SIZE];
+
+			snprintf(filename, sizeof(filename), "%s/%s", udev_root, name_loop->name);
+			filename[sizeof(filename)-1] = '\0';
+
+			dbg("symlink '%s' to node '%s' requested", filename, udev->name);
+			if (!udev->test_run)
+				if (strchr(filename, '/'))
+					create_path(filename);
+
+			/* optimize relative link */
+			linktarget[0] = '\0';
+			i = 0;
+			tail = 0;
+			while (udev->name[i] && (udev->name[i] == name_loop->name[i])) {
+				if (udev->name[i] == '/')
+					tail = i+1;
+				i++;
+			}
+			while (name_loop->name[i] != '\0') {
+				if (name_loop->name[i] == '/')
+					strlcat(linktarget, "../", sizeof(linktarget));
+				i++;
+			}
+
+			strlcat(linktarget, &udev->name[tail], sizeof(linktarget));
+
+			info("creating symlink '%s' to '%s'", filename, linktarget);
+			if (!udev->test_run) {
+				unlink(filename);
+				selinux_setfscreatecon(filename, NULL, S_IFLNK);
+				if (symlink(linktarget, filename) != 0)
+					err("symlink(%s, %s) failed: %s", linktarget, filename, strerror(errno));
+				selinux_resetfscreatecon();
+			}
+
+			strlcat(symlinks, filename, sizeof(symlinks));
+			strlcat(symlinks, " ", sizeof(symlinks));
+		}
+
+		remove_trailing_chars(symlinks, ' ');
+		setenv("DEVLINKS", symlinks, 1);
+	}
+
+exit:
+	selinux_exit();
+	return retval;
+}
+
+int udev_node_remove(struct udevice *udev)
+{
+	char filename[PATH_SIZE];
+	char partitionname[PATH_SIZE];
+	struct name_entry *name_loop;
+	struct stat stats;
+	int retval;
+	int i;
+	int num;
+
+	if (!list_empty(&udev->symlink_list)) {
+		char symlinks[512] = "";
+
+		list_for_each_entry(name_loop, &udev->symlink_list, node) {
+			snprintf(filename, sizeof(filename), "%s/%s", udev_root, name_loop->name);
+			filename[sizeof(filename)-1] = '\0';
+
+			if (stat(filename, &stats) != 0) {
+				dbg("symlink '%s' not found", filename);
+				continue;
+			}
+			if (udev->devt && stats.st_rdev != udev->devt) {
+				info("symlink '%s' points to a different device, skip removal", filename);
+				continue;
+			}
+
+			info("removing symlink '%s'", filename);
+			unlink(filename);
+
+			if (strchr(filename, '/'))
+				delete_path(filename);
+
+			strlcat(symlinks, filename, sizeof(symlinks));
+			strlcat(symlinks, " ", sizeof(symlinks));
+		}
+
+		remove_trailing_chars(symlinks, ' ');
+		if (symlinks[0] != '\0')
+			setenv("DEVLINKS", symlinks, 1);
+	}
+
+	snprintf(filename, sizeof(filename), "%s/%s", udev_root, udev->name);
+	filename[sizeof(filename)-1] = '\0';
+
+	if (stat(filename, &stats) != 0) {
+		dbg("device node '%s' not found", filename);
+		return -1;
+	}
+	if (udev->devt && stats.st_rdev != udev->devt) {
+		info("device node '%s' points to a different device, skip removal", filename);
+		return -1;
+	}
+
+	info("removing device node '%s'", filename);
+	retval = unlink_secure(filename);
+	if (retval)
+		return retval;
+
+	setenv("DEVNAME", filename, 1);
+
+	num = udev->partitions;
+	if (num > 0) {
+		info("removing all_partitions '%s[1-%i]'", filename, num);
+		if (num > 255) {
+			info("garbage from udev database, skip all_partitions removal");
+			return -1;
+		}
+		for (i = 1; i <= num; i++) {
+			snprintf(partitionname, sizeof(partitionname), "%s%d", filename, i);
+			partitionname[sizeof(partitionname)-1] = '\0';
+			unlink_secure(partitionname);
+		}
+	}
+
+	if (strchr(udev->name, '/'))
+		delete_path(filename);
+
+	return retval;
+}