diff options
Diffstat (limited to 'udev/udev_node.c')
| -rw-r--r-- | udev/udev_node.c | 448 |
1 files changed, 448 insertions, 0 deletions
diff --git a/udev/udev_node.c b/udev/udev_node.c new file mode 100644 index 0000000000..78b6747043 --- /dev/null +++ b/udev/udev_node.c @@ -0,0 +1,448 @@ +/* + * Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com> + * Copyright (C) 2004-2006 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., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 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 <dirent.h> +#include <sys/stat.h> +#include <sys/types.h> + +#include "udev.h" +#include "udev_rules.h" +#include "udev_selinux.h" + +#define TMP_FILE_EXT ".udev-tmp" + +int udev_node_mknod(struct udevice *udev, const char *file, dev_t devt, mode_t mode, uid_t uid, gid_t gid) +{ + char file_tmp[PATH_SIZE + sizeof(TMP_FILE_EXT)]; + struct stat stats; + int preserve = 0; + int err = 0; + + if (major(devt) != 0 && strcmp(udev->dev->subsystem, "block") == 0) + mode |= S_IFBLK; + else + mode |= S_IFCHR; + + if (lstat(file, &stats) == 0) { + if (((stats.st_mode & S_IFMT) == (mode & S_IFMT)) && (stats.st_rdev == devt)) { + info("preserve file '%s', because it has correct dev_t\n", file); + preserve = 1; + selinux_setfilecon(file, udev->dev->kernel, mode); + } else { + info("atomically replace existing file '%s'\n", file); + strlcpy(file_tmp, file, sizeof(file_tmp)); + strlcat(file_tmp, TMP_FILE_EXT, sizeof(file_tmp)); + unlink(file_tmp); + selinux_setfscreatecon(file_tmp, udev->dev->kernel, mode); + err = mknod(file_tmp, mode, devt); + selinux_resetfscreatecon(); + if (err != 0) { + err("mknod(%s, %#o, %u, %u) failed: %s\n", + file_tmp, mode, major(devt), minor(devt), strerror(errno)); + goto exit; + } + err = rename(file_tmp, file); + if (err != 0) { + err("rename(%s, %s) failed: %s\n", + file_tmp, file, strerror(errno)); + unlink(file_tmp); + } + } + } else { + info("mknod(%s, %#o, (%u,%u))\n", file, mode, major(devt), minor(devt)); + selinux_setfscreatecon(file, udev->dev->kernel, mode); + err = mknod(file, mode, devt); + selinux_resetfscreatecon(); + if (err != 0) { + err("mknod(%s, %#o, (%u,%u) failed: %s\n", + file, mode, major(devt), minor(devt), strerror(errno)); + goto exit; + } + } + + if (!preserve || stats.st_mode != mode) { + info("chmod(%s, %#o)\n", file, mode); + err = chmod(file, mode); + if (err != 0) { + err("chmod(%s, %#o) failed: %s\n", file, mode, strerror(errno)); + goto exit; + } + } + + if (!preserve || stats.st_uid != uid || stats.st_gid != gid) { + info("chown(%s, %u, %u)\n", file, uid, gid); + err = chown(file, uid, gid); + if (err != 0) { + err("chown(%s, %u, %u) failed: %s\n", file, uid, gid, strerror(errno)); + goto exit; + } + } +exit: + return err; +} + +static int node_symlink(const char *node, const char *slink) +{ + struct stat stats; + char target[PATH_SIZE] = ""; + char slink_tmp[PATH_SIZE + sizeof(TMP_FILE_EXT)]; + int i = 0; + int tail = 0; + int len; + int retval = 0; + + /* use relative link */ + while (node[i] && (node[i] == slink[i])) { + if (node[i] == '/') + tail = i+1; + i++; + } + while (slink[i] != '\0') { + if (slink[i] == '/') + strlcat(target, "../", sizeof(target)); + i++; + } + strlcat(target, &node[tail], sizeof(target)); + + /* preserve link with correct target, do not replace node of other device */ + if (lstat(slink, &stats) == 0) { + if (S_ISBLK(stats.st_mode) || S_ISCHR(stats.st_mode)) { + struct stat stats2; + + info("found existing node instead of symlink '%s'\n", slink); + if (lstat(node, &stats2) == 0) { + if ((stats.st_mode & S_IFMT) == (stats2.st_mode & S_IFMT) && + stats.st_rdev == stats2.st_rdev) { + info("replace device node '%s' with symlink to our node '%s'\n", slink, node); + } else { + err("device node '%s' already exists, link to '%s' will not overwrite it\n", slink, node); + goto exit; + } + } + } else if (S_ISLNK(stats.st_mode)) { + char buf[PATH_SIZE]; + + info("found existing symlink '%s'\n", slink); + len = readlink(slink, buf, sizeof(buf)); + if (len > 0) { + buf[len] = '\0'; + if (strcmp(target, buf) == 0) { + info("preserve already existing symlink '%s' to '%s'\n", slink, target); + selinux_setfilecon(slink, NULL, S_IFLNK); + goto exit; + } + } + } + } else { + info("creating symlink '%s' to '%s'\n", slink, target); + selinux_setfscreatecon(slink, NULL, S_IFLNK); + retval = symlink(target, slink); + selinux_resetfscreatecon(); + if (retval == 0) + goto exit; + } + + info("atomically replace '%s'\n", slink); + strlcpy(slink_tmp, slink, sizeof(slink_tmp)); + strlcat(slink_tmp, TMP_FILE_EXT, sizeof(slink_tmp)); + unlink(slink_tmp); + selinux_setfscreatecon(slink, NULL, S_IFLNK); + retval = symlink(target, slink_tmp); + selinux_resetfscreatecon(); + if (retval != 0) { + err("symlink(%s, %s) failed: %s\n", target, slink_tmp, strerror(errno)); + goto exit; + } + retval = rename(slink_tmp, slink); + if (retval != 0) { + err("rename(%s, %s) failed: %s\n", slink_tmp, slink, strerror(errno)); + unlink(slink_tmp); + goto exit; + } +exit: + return retval; +} + +static int update_link(struct udevice *udev, const char *name) +{ + LIST_HEAD(name_list); + char slink[PATH_SIZE]; + char node[PATH_SIZE]; + struct udevice *udev_db; + struct name_entry *device; + char target[PATH_MAX] = ""; + int count; + int priority = 0; + int rc = 0; + + strlcpy(slink, udev_root, sizeof(slink)); + strlcat(slink, "/", sizeof(slink)); + strlcat(slink, name, sizeof(slink)); + + count = udev_db_get_devices_by_name(name, &name_list); + info("found %i devices with name '%s'\n", count, name); + + /* if we don't have a reference, delete it */ + if (count <= 0) { + info("no reference left, remove '%s'\n", name); + if (!udev->test_run) { + unlink(slink); + delete_path(slink); + } + goto out; + } + + /* find the device with the highest priority */ + list_for_each_entry(device, &name_list, node) { + info("found '%s' for '%s'\n", device->name, name); + + /* did we find ourself? we win, if we have the same priority */ + if (strcmp(udev->dev->devpath, device->name) == 0) { + info("compare (our own) priority of '%s' %i >= %i\n", + udev->dev->devpath, udev->link_priority, priority); + if (strcmp(udev->name, name) == 0) { + info("'%s' is our device node, database inconsistent, skip link update\n", udev->name); + } else if (target[0] == '\0' || udev->link_priority >= priority) { + priority = udev->link_priority; + strlcpy(target, udev->name, sizeof(target)); + } + continue; + } + + /* another device, read priority from database */ + udev_db = udev_device_init(NULL); + if (udev_db == NULL) + continue; + if (udev_db_get_device(udev_db, device->name) == 0) { + if (strcmp(udev_db->name, name) == 0) { + info("'%s' is a device node of '%s', skip link update\n", udev_db->name, device->name); + } else { + info("compare priority of '%s' %i > %i\n", + udev_db->dev->devpath, udev_db->link_priority, priority); + if (target[0] == '\0' || udev_db->link_priority > priority) { + priority = udev_db->link_priority; + strlcpy(target, udev_db->name, sizeof(target)); + } + } + } + udev_device_cleanup(udev_db); + } + name_list_cleanup(&name_list); + + if (target[0] == '\0') { + info("no current target for '%s' found\n", name); + rc = 1; + goto out; + } + + /* create symlink to the target with the highest priority */ + strlcpy(node, udev_root, sizeof(node)); + strlcat(node, "/", sizeof(node)); + strlcat(node, target, sizeof(node)); + info("'%s' with target '%s' has the highest priority %i, create it\n", name, target, priority); + if (!udev->test_run) { + create_path(slink); + node_symlink(node, slink); + } +out: + return rc; +} + +void udev_node_update_symlinks(struct udevice *udev, struct udevice *udev_old) +{ + struct name_entry *name_loop; + char symlinks[PATH_SIZE] = ""; + + list_for_each_entry(name_loop, &udev->symlink_list, node) { + info("update symlink '%s' of '%s'\n", name_loop->name, udev->dev->devpath); + update_link(udev, name_loop->name); + strlcat(symlinks, udev_root, sizeof(symlinks)); + strlcat(symlinks, "/", sizeof(symlinks)); + strlcat(symlinks, name_loop->name, sizeof(symlinks)); + strlcat(symlinks, " ", sizeof(symlinks)); + } + + /* export symlinks to environment */ + remove_trailing_chars(symlinks, ' '); + if (symlinks[0] != '\0') + setenv("DEVLINKS", symlinks, 1); + + /* update possible left-over symlinks (device metadata changed) */ + if (udev_old != NULL) { + struct name_entry *link_loop; + struct name_entry *link_old_loop; + int found; + + /* remove current symlinks from old list */ + list_for_each_entry(link_old_loop, &udev_old->symlink_list, node) { + found = 0; + list_for_each_entry(link_loop, &udev->symlink_list, node) { + if (strcmp(link_old_loop->name, link_loop->name) == 0) { + found = 1; + break; + } + } + if (!found) { + /* link does no longer belong to this device */ + info("update old symlink '%s' no longer belonging to '%s'\n", + link_old_loop->name, udev->dev->devpath); + update_link(udev, link_old_loop->name); + } + } + + /* + * if the node name has changed, delete the node, + * or possibly restore a symlink of another device + */ + if (strcmp(udev->name, udev_old->name) != 0) + update_link(udev, udev_old->name); + } +} + +int udev_node_add(struct udevice *udev) +{ + char filename[PATH_SIZE]; + uid_t uid; + gid_t gid; + int i; + int retval = 0; + + strlcpy(filename, udev_root, sizeof(filename)); + strlcat(filename, "/", sizeof(filename)); + strlcat(filename, udev->name, sizeof(filename)); + 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\n", + 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 != NULL) { + range = atoi(attr); + if (range > 1) + udev->partitions = range-1; + } + info("creating device partition nodes '%s[1-%i]'\n", 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); + } + } + } +exit: + return retval; +} + +int udev_node_remove(struct udevice *udev) +{ + char filename[PATH_SIZE]; + char partitionname[PATH_SIZE]; + struct stat stats; + int retval = 0; + int num; + + strlcpy(filename, udev_root, sizeof(filename)); + strlcat(filename, "/", sizeof(filename)); + strlcat(filename, udev->name, sizeof(filename)); + if (stat(filename, &stats) != 0) { + info("device node '%s' not found\n", filename); + return 0; + } + if (udev->devt && stats.st_rdev != udev->devt) { + info("device node '%s' points to a different device, skip removal\n", filename); + return -1; + } + + info("removing device node '%s'\n", filename); + if (!udev->test_run) + retval = unlink_secure(filename); + if (retval) + return retval; + + setenv("DEVNAME", filename, 1); + num = udev->partitions; + if (num > 0) { + int i; + + info("removing all_partitions '%s[1-%i]'\n", filename, num); + if (num > 255) + return -1; + for (i = 1; i <= num; i++) { + snprintf(partitionname, sizeof(partitionname), "%s%d", filename, i); + partitionname[sizeof(partitionname)-1] = '\0'; + if (!udev->test_run) + unlink_secure(partitionname); + } + } + delete_path(filename); + return retval; +} |