X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udev%2Fudev-node.c;h=6fbe250b85ff0e836ae30302302d25c267c7471d;hp=39bec3e166ba9cc5f9be49324df28b36c9396ec8;hb=79449642ebcb6170adb8d6391518e328a07d9552;hpb=b6a2637524e4b94ba51abcf5ee42f3676c9755ed diff --git a/udev/udev-node.c b/udev/udev-node.c index 39bec3e16..6fbe250b8 100644 --- a/udev/udev-node.c +++ b/udev/udev-node.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2003-2009 Kay Sievers + * Copyright (C) 2003-2010 Kay Sievers * * 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 @@ -25,6 +25,7 @@ #include #include #include +#include #include #include @@ -32,15 +33,13 @@ #define TMP_FILE_EXT ".udev-tmp" -int udev_node_mknod(struct udev_device *dev, const char *file, dev_t devnum, mode_t mode, uid_t uid, gid_t gid) +int udev_node_mknod(struct udev_device *dev, const char *file, mode_t mode, uid_t uid, gid_t gid) { struct udev *udev = udev_device_get_udev(dev); + dev_t devnum = udev_device_get_devnum(dev); struct stat stats; - int preserve = 0; int err = 0; - if (major(devnum) == 0) - devnum = udev_device_get_devnum(dev); if (strcmp(udev_device_get_subsystem(dev), "block") == 0) mode |= S_IFBLK; @@ -53,8 +52,23 @@ int udev_node_mknod(struct udev_device *dev, const char *file, dev_t devnum, mod if (lstat(file, &stats) == 0) { if (((stats.st_mode & S_IFMT) == (mode & S_IFMT)) && (stats.st_rdev == devnum)) { info(udev, "preserve file '%s', because it has correct dev_t\n", file); - preserve = 1; - udev_selinux_lsetfilecon(udev, file, mode); + if (stats.st_mode != mode || stats.st_uid != uid || stats.st_gid != gid) { + info(udev, "set permissions %s, %#o, uid=%u, gid=%u\n", file, mode, uid, gid); + chmod(file, mode); + chown(file, uid, gid); + } else { + info(udev, "preserve permissions %s, %#o, uid=%u, gid=%u\n", file, mode, uid, gid); + } + /* + * Set initial selinux file context only on add events. + * We set the proper context on bootup (triger) or for newly + * added devices, but we don't change it later, in case + * something else has set a custom context in the meantime. + */ + if (strcmp(udev_device_get_action(dev), "add") == 0) + udev_selinux_lsetfilecon(udev, file, mode); + /* always update timestamp when we re-use the node, like on media change events */ + utimensat(AT_FDCWD, file, NULL, 0); } else { char file_tmp[UTIL_PATH_SIZE + sizeof(TMP_FILE_EXT)]; @@ -65,48 +79,37 @@ int udev_node_mknod(struct udev_device *dev, const char *file, dev_t devnum, mod err = mknod(file_tmp, mode, devnum); udev_selinux_resetfscreatecon(udev); if (err != 0) { - err(udev, "mknod(%s, %#o, %u, %u) failed: %m\n", - file_tmp, mode, major(devnum), minor(devnum)); + err(udev, "mknod '%s' %u:%u %#o failed: %m\n", + file_tmp, major(devnum), minor(devnum), mode); goto exit; } err = rename(file_tmp, file); if (err != 0) { - err(udev, "rename(%s, %s) failed: %m\n", file_tmp, file); + err(udev, "rename '%s' '%s' failed: %m\n", file_tmp, file); unlink(file_tmp); + goto exit; } + info(udev, "set permissions '%s' %#o uid=%u gid=%u\n", file, mode, uid, gid); + chmod(file, mode); + chown(file, uid, gid); } } else { - info(udev, "mknod(%s, %#o, (%u,%u))\n", file, mode, major(devnum), minor(devnum)); + info(udev, "mknod '%s' %u:%u %#o\n", file, major(devnum), minor(devnum), mode); do { - util_create_path(udev, file); + err = util_create_path_selinux(udev, file); + if (err != 0 && err != -ENOENT) + break; udev_selinux_setfscreatecon(udev, file, mode); err = mknod(file, mode, devnum); if (err != 0) - err = errno; + err = -errno; udev_selinux_resetfscreatecon(udev); - } while (err == ENOENT); - if (err != 0) { - err(udev, "mknod(%s, %#o, (%u,%u) failed: %m\n", file, mode, major(devnum), minor(devnum)); - goto exit; - } - } - - if (!preserve || stats.st_mode != mode) { - info(udev, "chmod(%s, %#o)\n", file, mode); - err = chmod(file, mode); - if (err != 0) { - err(udev, "chmod(%s, %#o) failed: %m\n", file, mode); - goto exit; - } - } - - if (!preserve || stats.st_uid != uid || stats.st_gid != gid) { - info(udev, "chown(%s, %u, %u)\n", file, uid, gid); - err = chown(file, uid, gid); - if (err != 0) { - err(udev, "chown(%s, %u, %u) failed: %m\n", file, uid, gid); - goto exit; - } + } while (err == -ENOENT); + if (err != 0) + err(udev, "mknod '%s' %u:%u %#o' failed: %m\n", file, major(devnum), minor(devnum), mode); + info(udev, "set permissions '%s' %#o uid=%u gid=%u\n", file, mode, uid, gid); + chmod(file, mode); + chown(file, uid, gid); } exit: return err; @@ -167,12 +170,13 @@ static int node_symlink(struct udev *udev, const char *node, const char *slink) dbg(udev, "found existing symlink '%s'\n", slink); len = readlink(slink, buf, sizeof(buf)); - if (len > 0) { + if (len > 0 && len < (int)sizeof(buf)) { buf[len] = '\0'; if (strcmp(target, buf) == 0) { info(udev, "preserve already existing symlink '%s' to '%s'\n", slink, target); udev_selinux_lsetfilecon(udev, slink, S_IFLNK); + utimensat(AT_FDCWD, slink, NULL, AT_SYMLINK_NOFOLLOW); goto exit; } } @@ -180,13 +184,15 @@ static int node_symlink(struct udev *udev, const char *node, const char *slink) } else { info(udev, "creating symlink '%s' to '%s'\n", slink, target); do { - util_create_path(udev, slink); + err = util_create_path_selinux(udev, slink); + if (err != 0 && err != -ENOENT) + break; udev_selinux_setfscreatecon(udev, slink, S_IFLNK); err = symlink(target, slink); if (err != 0) - err = errno; + err = -errno; udev_selinux_resetfscreatecon(udev); - } while (err == ENOENT); + } while (err == -ENOENT); if (err == 0) goto exit; } @@ -195,20 +201,22 @@ static int node_symlink(struct udev *udev, const char *node, const char *slink) util_strscpyl(slink_tmp, sizeof(slink_tmp), slink, TMP_FILE_EXT, NULL); unlink(slink_tmp); do { - util_create_path(udev, slink); - udev_selinux_setfscreatecon(udev, slink, S_IFLNK); + err = util_create_path_selinux(udev, slink_tmp); + if (err != 0 && err != -ENOENT) + break; + udev_selinux_setfscreatecon(udev, slink_tmp, S_IFLNK); err = symlink(target, slink_tmp); if (err != 0) - err = errno; + err = -errno; udev_selinux_resetfscreatecon(udev); - } while (err == ENOENT); + } while (err == -ENOENT); if (err != 0) { - err(udev, "symlink(%s, %s) failed: %m\n", target, slink_tmp); + err(udev, "symlink '%s' '%s' failed: %m\n", target, slink_tmp); goto exit; } err = rename(slink_tmp, slink); if (err != 0) { - err(udev, "rename(%s, %s) failed: %m\n", slink_tmp, slink); + err(udev, "rename '%s' '%s' failed: %m\n", slink_tmp, slink); unlink(slink_tmp); } exit: @@ -235,28 +243,20 @@ static const char *link_find_prioritized(struct udev_device *dev, bool add, cons for (;;) { struct udev_device *dev_db; struct dirent *dent; - char devpath[UTIL_PATH_SIZE]; - char syspath[UTIL_PATH_SIZE]; - ssize_t len; dent = readdir(dir); if (dent == NULL || dent->d_name[0] == '\0') break; if (dent->d_name[0] == '.') continue; - dbg(udev, "found '%s/%s'\n", stackdir, dent->d_name); - len = readlinkat(dirfd(dir), dent->d_name, devpath, sizeof(devpath)); - if (len <= 0 || len == (ssize_t)sizeof(devpath)) - continue; - devpath[len] = '\0'; - util_strscpyl(syspath, sizeof(syspath), udev_get_sys_path(udev), devpath, NULL); - info(udev, "found '%s' claiming '%s'\n", syspath, stackdir); + + info(udev, "found '%s' claiming '%s'\n", dent->d_name, stackdir); /* did we find ourself? */ - if (strcmp(udev_device_get_syspath(dev), syspath) == 0) + if (strcmp(dent->d_name, udev_device_get_id_filename(dev)) == 0) continue; - dev_db = udev_device_new_from_syspath(udev, syspath); + dev_db = udev_device_new_from_id_filename(udev, dent->d_name); if (dev_db != NULL) { const char *devnode; @@ -266,7 +266,7 @@ static const char *link_find_prioritized(struct udev_device *dev, bool add, cons udev_device_get_devnode(dev_db), udev_device_get_devlink_priority(dev_db)); if (target == NULL || udev_device_get_devlink_priority(dev_db) > priority) { info(udev, "'%s' claims priority %i for '%s'\n", - syspath, udev_device_get_devlink_priority(dev_db), stackdir); + udev_device_get_syspath(dev_db), udev_device_get_devlink_priority(dev_db), stackdir); priority = udev_device_get_devlink_priority(dev_db); util_strscpy(buf, bufsize, devnode); target = buf; @@ -275,6 +275,7 @@ static const char *link_find_prioritized(struct udev_device *dev, bool add, cons udev_device_unref(dev_db); } } + closedir(dir); return target; } @@ -291,33 +292,41 @@ static void link_update(struct udev_device *dev, const char *slink, bool add) dbg(udev, "update symlink '%s' of '%s'\n", slink, udev_device_get_syspath(dev)); util_path_encode(&slink[strlen(udev_get_dev_path(udev))+1], name_enc, sizeof(name_enc)); - snprintf(dirname, sizeof(dirname), "%s/.udev/links/%s", udev_get_dev_path(udev), name_enc); - snprintf(filename, sizeof(filename), "%s/%c%u:%u", dirname, - strcmp(udev_device_get_subsystem(dev), "block") == 0 ? 'b' : 'c', - major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev))); + util_strscpyl(dirname, sizeof(dirname), udev_get_run_path(udev), "/links/", name_enc, NULL); + util_strscpyl(filename, sizeof(filename), dirname, "/", udev_device_get_id_filename(dev), NULL); if (!add) { dbg(udev, "removing index: '%s'\n", filename); - unlink(filename); - util_delete_path(udev, filename); + if (unlink(filename) == 0) + rmdir(dirname); } target = link_find_prioritized(dev, add, dirname, buf, sizeof(buf)); if (target == NULL) { info(udev, "no reference left, remove '%s'\n", slink); - unlink(slink); - util_delete_path(udev, slink); + if (unlink(slink) == 0) + util_delete_path(udev, slink); } else { info(udev, "creating link '%s' to '%s'\n", slink, target); node_symlink(udev, target, slink); } if (add) { + int err; + dbg(udev, "creating index: '%s'\n", filename); do { - util_create_path(udev, filename); - symlink(udev_device_get_devpath(dev), filename); - } while (errno == ENOENT); + int fd; + + err = util_create_path(udev, filename); + if (err != 0 && err != -ENOENT) + break; + fd = open(filename, O_WRONLY|O_CREAT|O_CLOEXEC|O_TRUNC|O_NOFOLLOW, 0444); + if (fd >= 0) + close(fd); + else + err = -errno; + } while (err == -ENOENT); } } @@ -354,8 +363,7 @@ void udev_node_update_old_links(struct udev_device *dev, struct udev_device *dev int udev_node_add(struct udev_device *dev, mode_t mode, uid_t uid, gid_t gid) { struct udev *udev = udev_device_get_udev(dev); - int i; - int num; + char filename[UTIL_PATH_SIZE]; struct udev_list_entry *list_entry; int err = 0; @@ -364,31 +372,21 @@ int udev_node_add(struct udev_device *dev, mode_t mode, uid_t uid, gid_t gid) major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev)), mode, uid, gid); - if (udev_node_mknod(dev, NULL, makedev(0,0), mode, uid, gid) != 0) { + if (udev_node_mknod(dev, NULL, mode, uid, gid) != 0) { err = -1; goto exit; } - /* create all_partitions if requested */ - num = udev_device_get_num_fake_partitions(dev); - if (num > 0) { - info(udev, "creating device partition nodes '%s[1-%i]'\n", udev_device_get_devnode(dev), num); - for (i = 1; i <= num; i++) { - char partitionname[UTIL_PATH_SIZE]; - dev_t part_devnum; - - snprintf(partitionname, sizeof(partitionname), "%s%d", - udev_device_get_devnode(dev), i); - partitionname[sizeof(partitionname)-1] = '\0'; - part_devnum = makedev(major(udev_device_get_devnum(dev)), - minor(udev_device_get_devnum(dev)) + i); - udev_node_mknod(dev, partitionname, part_devnum, mode, uid, gid); - } - } + /* always add /dev/{block,char}/$major:$minor */ + snprintf(filename, sizeof(filename), "%s/%s/%u:%u", + udev_get_dev_path(udev), + strcmp(udev_device_get_subsystem(dev), "block") == 0 ? "block" : "char", + major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev))); + node_symlink(udev, udev_device_get_devnode(dev), filename); /* create/update symlinks, add symlinks to name index */ udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev)) { - if (udev_list_entry_get_flag(list_entry)) + if (udev_list_entry_get_num(list_entry)) /* simple unmanaged link name */ node_symlink(udev, udev_device_get_devnode(dev), udev_list_entry_get_name(list_entry)); else @@ -403,45 +401,54 @@ int udev_node_remove(struct udev_device *dev) struct udev *udev = udev_device_get_udev(dev); struct udev_list_entry *list_entry; const char *devnode; - char partitionname[UTIL_PATH_SIZE]; struct stat stats; + struct udev_device *dev_check; + char filename[UTIL_PATH_SIZE]; int err = 0; - int num; - /* remove,update symlinks, remove symlinks from name index */ + /* remove/update symlinks, remove symlinks from name index */ udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev)) link_update(dev, udev_list_entry_get_name(list_entry), 0); devnode = udev_device_get_devnode(dev); if (devnode == NULL) - return 0; + goto out; + if (stat(devnode, &stats) != 0) { info(udev, "device node '%s' not found\n", devnode); - return 0; + goto out; } + if (stats.st_rdev != udev_device_get_devnum(dev)) { info(udev, "device node '%s' points to a different device, skip removal\n", devnode); - return -1; + err = -1; + goto out; + } + + if (stats.st_mode & 01000) { + info(udev, "device node '%s' has sticky bit set, skip removal\n", devnode); + goto out; + } + + dev_check = udev_device_new_from_syspath(udev, udev_device_get_syspath(dev)); + if (dev_check != NULL) { + /* do not remove device node if the same sys-device is re-created in the meantime */ + info(udev, "keeping device node of existing device'%s'\n", devnode); + udev_device_unref(dev_check); + goto out; } info(udev, "removing device node '%s'\n", devnode); err = util_unlink_secure(udev, devnode); - if (err) - return err; - - num = udev_device_get_num_fake_partitions(dev); - if (num > 0) { - int i; - - info(udev, "removing all_partitions '%s[1-%i]'\n", devnode, num); - if (num > 255) - return -1; - for (i = 1; i <= num; i++) { - snprintf(partitionname, sizeof(partitionname), "%s%d", devnode, i); - partitionname[sizeof(partitionname)-1] = '\0'; - util_unlink_secure(udev, partitionname); - } - } - util_delete_path(udev, devnode); + if (err == 0) + util_delete_path(udev, devnode); + + /* remove /dev/{block,char}/$major:$minor */ + snprintf(filename, sizeof(filename), "%s/%s/%u:%u", + udev_get_dev_path(udev), + strcmp(udev_device_get_subsystem(dev), "block") == 0 ? "block" : "char", + major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev))); + unlink(filename); +out: return err; }