X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udev%2Fudev-node.c;h=3685485eb1066a113226733e366aa5eeb0160f3c;hp=100ca92903ef2baf41ff36b6a5f2326176221325;hb=676d294c23cf999ac7d192b058476f91242550c0;hpb=f408fd919a7af5fcd5dac5a505411842b3e8d853 diff --git a/udev/udev-node.c b/udev/udev-node.c index 100ca9290..3685485eb 100644 --- a/udev/udev-node.c +++ b/udev/udev-node.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2004-2008 Kay Sievers + * Copyright (C) 2003-2009 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 @@ -19,6 +19,7 @@ #include #include #include +#include #include #include #include @@ -31,44 +32,9 @@ #define TMP_FILE_EXT ".udev-tmp" -/* reverse mapping from the device file name to the devpath */ -static int name_index(struct udev *udev, const char *devpath, const char *name, int add, int test) -{ - char device[UTIL_PATH_SIZE]; - char filename[UTIL_PATH_SIZE * 2]; - size_t devlen = strlen(udev_get_dev_path(udev))+1; - size_t start; - int fd; - - /* directory with device name */ - util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename)); - start = util_strlcat(filename, "/.udev/names/", sizeof(filename)); - util_strlcat(filename, &name[devlen], sizeof(filename)); - util_path_encode(&filename[start], sizeof(filename) - start); - /* entry with the devpath */ - util_strlcpy(device, devpath, sizeof(device)); - util_path_encode(device, sizeof(device)); - util_strlcat(filename, "/", sizeof(filename)); - util_strlcat(filename, device, sizeof(filename)); - - if (add) { - dbg(udev, "creating index: '%s'\n", filename); - util_create_path(udev, filename); - fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644); - if (fd > 0) - close(fd); - } else { - dbg(udev, "removing index: '%s'\n", filename); - unlink(filename); - util_delete_path(udev, filename); - } - return 0; -} - int udev_node_mknod(struct udev_device *dev, const char *file, dev_t devnum, mode_t mode, uid_t uid, gid_t gid) { struct udev *udev = udev_device_get_udev(dev); - char file_tmp[UTIL_PATH_SIZE + sizeof(TMP_FILE_EXT)]; struct stat stats; int preserve = 0; int err = 0; @@ -90,9 +56,10 @@ int udev_node_mknod(struct udev_device *dev, const char *file, dev_t devnum, mod preserve = 1; udev_selinux_lsetfilecon(udev, file, mode); } else { + char file_tmp[UTIL_PATH_SIZE + sizeof(TMP_FILE_EXT)]; + info(udev, "atomically replace existing file '%s'\n", file); - util_strlcpy(file_tmp, file, sizeof(file_tmp)); - util_strlcat(file_tmp, TMP_FILE_EXT, sizeof(file_tmp)); + util_strscpyl(file_tmp, sizeof(file_tmp), file, TMP_FILE_EXT, NULL); unlink(file_tmp); udev_selinux_setfscreatecon(udev, file_tmp, mode); err = mknod(file_tmp, mode, devnum); @@ -110,6 +77,7 @@ int udev_node_mknod(struct udev_device *dev, const char *file, dev_t devnum, mod } } else { info(udev, "mknod(%s, %#o, (%u,%u))\n", file, mode, major(devnum), minor(devnum)); + util_create_path(udev, file); udev_selinux_setfscreatecon(udev, file, mode); err = mknod(file, mode, devnum); udev_selinux_resetfscreatecon(udev); @@ -144,10 +112,11 @@ static int node_symlink(struct udev *udev, const char *node, const char *slink) { struct stat stats; char target[UTIL_PATH_SIZE]; + char *s; + size_t l; char slink_tmp[UTIL_PATH_SIZE + sizeof(TMP_FILE_EXT)]; int i = 0; int tail = 0; - int len; int err = 0; /* use relative link */ @@ -157,12 +126,18 @@ static int node_symlink(struct udev *udev, const char *node, const char *slink) tail = i+1; i++; } + s = target; + l = sizeof(target); while (slink[i] != '\0') { if (slink[i] == '/') - util_strlcat(target, "../", sizeof(target)); + l = util_strpcpy(&s, l, "../"); i++; } - util_strlcat(target, &node[tail], sizeof(target)); + l = util_strscpy(s, l, &node[tail]); + if (l == 0) { + err = -EINVAL; + goto exit; + } /* preserve link with correct target, do not replace node of other device */ if (lstat(slink, &stats) == 0) { @@ -172,7 +147,7 @@ static int node_symlink(struct udev *udev, const char *node, const char *slink) info(udev, "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) { + stats.st_rdev == stats2.st_rdev && stats.st_ino != stats2.st_ino) { info(udev, "replace device node '%s' with symlink to our node '%s'\n", slink, node); } else { @@ -184,6 +159,7 @@ static int node_symlink(struct udev *udev, const char *node, const char *slink) } } else if (S_ISLNK(stats.st_mode)) { char buf[UTIL_PATH_SIZE]; + int len; dbg(udev, "found existing symlink '%s'\n", slink); len = readlink(slink, buf, sizeof(buf)); @@ -199,6 +175,7 @@ static int node_symlink(struct udev *udev, const char *node, const char *slink) } } else { info(udev, "creating symlink '%s' to '%s'\n", slink, target); + util_create_path(udev, slink); udev_selinux_setfscreatecon(udev, slink, S_IFLNK); err = symlink(target, slink); udev_selinux_resetfscreatecon(udev); @@ -207,9 +184,9 @@ static int node_symlink(struct udev *udev, const char *node, const char *slink) } info(udev, "atomically replace '%s'\n", slink); - util_strlcpy(slink_tmp, slink, sizeof(slink_tmp)); - util_strlcat(slink_tmp, TMP_FILE_EXT, sizeof(slink_tmp)); + util_strscpyl(slink_tmp, sizeof(slink_tmp), slink, TMP_FILE_EXT, NULL); unlink(slink_tmp); + util_create_path(udev, slink); udev_selinux_setfscreatecon(udev, slink, S_IFLNK); err = symlink(target, slink_tmp); udev_selinux_resetfscreatecon(udev); @@ -221,149 +198,119 @@ static int node_symlink(struct udev *udev, const char *node, const char *slink) if (err != 0) { err(udev, "rename(%s, %s) failed: %m\n", slink_tmp, slink); unlink(slink_tmp); - goto exit; } exit: return err; } -static int name_index_get_devices(struct udev *udev, const char *name, struct udev_list_node *dev_list) +/* find device node of device with highest priority */ +static const char *link_find_prioritized(struct udev_device *dev, bool add, const char *stackdir, char *buf, size_t bufsize) { - char dirname[PATH_MAX]; - size_t devlen = strlen(udev_get_dev_path(udev))+1; - size_t start; + struct udev *udev = udev_device_get_udev(dev); DIR *dir; - int count = 0; - - util_strlcpy(dirname, udev_get_dev_path(udev), sizeof(dirname)); - start = util_strlcat(dirname, "/.udev/names/", sizeof(dirname)); - util_strlcat(dirname, &name[devlen], sizeof(dirname)); - util_path_encode(&dirname[start], sizeof(dirname) - start); - dir = opendir(dirname); - if (dir == NULL) { - dbg(udev, "no index directory '%s': %m\n", dirname); - count = -1; - goto out; + int priority = 0; + const char *target = NULL; + + if (add) { + priority = udev_device_get_devlink_priority(dev); + util_strscpy(buf, bufsize, udev_device_get_devnode(dev)); + target = buf; } - dbg(udev, "found index directory '%s'\n", dirname); - while (1) { - struct dirent *ent; - char device[UTIL_PATH_SIZE]; + dir = opendir(stackdir); + if (dir == NULL) + return target; + for (;;) { + struct udev_device *dev_db; + struct dirent *dent; + char devpath[UTIL_PATH_SIZE]; + char syspath[UTIL_PATH_SIZE]; + ssize_t len; - ent = readdir(dir); - if (ent == NULL || ent->d_name[0] == '\0') + dent = readdir(dir); + if (dent == NULL || dent->d_name[0] == '\0') break; - if (ent->d_name[0] == '.') + 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); + + /* did we find ourself? */ + if (strcmp(udev_device_get_syspath(dev), syspath) == 0) continue; - util_strlcpy(device, udev_get_sys_path(udev), sizeof(device)); - util_strlcat(device, ent->d_name, sizeof(device)); - util_path_decode(device); - udev_list_entry_add(udev, dev_list, device, NULL, 1, 0); - count++; + dev_db = udev_device_new_from_syspath(udev, syspath); + if (dev_db != NULL) { + const char *devnode; + + devnode = udev_device_get_devnode(dev_db); + if (devnode != NULL) { + dbg(udev, "compare priority of '%s'(%i) > '%s'(%i)\n", target, priority, + 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); + priority = udev_device_get_devlink_priority(dev_db); + util_strscpy(buf, bufsize, devnode); + target = buf; + } + } + udev_device_unref(dev_db); + } } - closedir(dir); -out: - return count; + return target; } -static int update_link(struct udev_device *dev, const char *slink, int test) +/* manage "stack of names" with possibly specified device priorities */ +static void link_update(struct udev_device *dev, const char *slink, bool add) { struct udev *udev = udev_device_get_udev(dev); - struct udev_list_node dev_list; - struct udev_list_entry *dev_entry; - char target[UTIL_PATH_SIZE]; - int count; - int priority = 0; - int rc = 0; + char name_enc[UTIL_PATH_SIZE]; + char filename[UTIL_PATH_SIZE * 2]; + char dirname[UTIL_PATH_SIZE]; + const char *target; + char buf[UTIL_PATH_SIZE]; dbg(udev, "update symlink '%s' of '%s'\n", slink, udev_device_get_syspath(dev)); - udev_list_init(&dev_list); - count = name_index_get_devices(udev, slink, &dev_list); - if (count > 1) - info(udev, "found %i devices with name '%s'\n", count, slink); - - /* if we don't have a reference, delete it */ - if (count <= 0) { - info(udev, "no reference left, remove '%s'\n", slink); - if (!test) { - unlink(slink); - util_delete_path(udev, slink); - } - goto out; - } - - /* find the device with the highest priority */ - target[0] = '\0'; - udev_list_entry_foreach(dev_entry, udev_list_get_entry(&dev_list)) { - const char *syspath; - struct udev_device *dev_db; - const char *devnode; - - syspath = udev_list_entry_get_name(dev_entry); - dbg(udev, "found '%s' for '%s'\n", syspath, slink); - - /* did we find ourself? we win, if we have the same priority */ - if (strcmp(udev_device_get_syspath(dev), syspath) == 0) { - dbg(udev, "compare (our own) priority of '%s' %i >= %i\n", - udev_device_get_devpath(dev), udev_device_get_devlink_priority(dev), priority); - if (strcmp(udev_device_get_devnode(dev), slink) == 0) { - info(udev, "'%s' is our device node, database inconsistent, skip link update\n", - udev_device_get_devnode(dev)); - } else if (target[0] == '\0' || udev_device_get_devlink_priority(dev) >= priority) { - priority = udev_device_get_devlink_priority(dev); - util_strlcpy(target, udev_device_get_devnode(dev), sizeof(target)); - } - continue; - } + 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))); - /* another device, read priority from database */ - dev_db = udev_device_new_from_syspath(udev, syspath); - if (dev_db == NULL) - continue; - devnode = udev_device_get_devnode(dev_db); - if (devnode != NULL) { - if (strcmp(devnode, slink) == 0) { - info(udev, "'%s' is a device node of '%s', skip link update\n", - devnode, syspath); - } else { - dbg(udev, "compare priority of '%s' %i > %i\n", - udev_device_get_devpath(dev_db), - udev_device_get_devlink_priority(dev_db), - priority); - if (target[0] == '\0' || udev_device_get_devlink_priority(dev_db) > priority) { - priority = udev_device_get_devlink_priority(dev_db); - util_strlcpy(target, devnode, sizeof(target)); - } - } - } - udev_device_unref(dev_db); + if (!add) { + dbg(udev, "removing index: '%s'\n", filename); + unlink(filename); + util_delete_path(udev, filename); } - udev_list_cleanup_entries(udev, &dev_list); - if (target[0] == '\0') { - info(udev, "no current target for '%s' found\n", slink); - rc = 1; - goto out; + 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); + } else { + info(udev, "creating link '%s' to '%s'\n", slink, target); + node_symlink(udev, target, slink); } - /* create symlink to the target with the highest priority */ - info(udev, "'%s' with target '%s' has the highest priority %i, create it\n", slink, target, priority); - if (!test) { - util_create_path(udev, slink); - node_symlink(udev, target, slink); + if (add) { + dbg(udev, "creating index: '%s'\n", filename); + util_create_path(udev, filename); + symlink(udev_device_get_devpath(dev), filename); } -out: - return rc; } -void udev_node_update_old_links(struct udev_device *dev, struct udev_device *dev_old, int test) +void udev_node_update_old_links(struct udev_device *dev, struct udev_device *dev_old) { struct udev *udev = udev_device_get_udev(dev); struct udev_list_entry *list_entry; - const char *devnode_old; /* update possible left-over symlinks */ udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev_old)) { @@ -371,10 +318,6 @@ void udev_node_update_old_links(struct udev_device *dev, struct udev_device *dev struct udev_list_entry *list_entry_current; int found; - /* check if old link name is now our node name */ - if (strcmp(name, udev_device_get_devnode(dev)) == 0) - continue; - /* check if old link name still belongs to this device */ found = 0; udev_list_entry_foreach(list_entry_current, udev_device_get_devlinks_list_entry(dev)) { @@ -388,25 +331,13 @@ void udev_node_update_old_links(struct udev_device *dev, struct udev_device *dev if (found) continue; - info(udev, "update old symlink '%s' no longer belonging to '%s'\n", name, udev_device_get_devpath(dev)); - name_index(udev, udev_device_get_devpath(dev), name, 0, test); - update_link(dev, name, test); - } - - /* - * if the node name has changed, delete the node, - * and possibly restore a symlink of another device - */ - devnode_old = udev_device_get_devnode(dev_old); - if (devnode_old != NULL) { - const char *devnode = udev_device_get_devnode(dev); - - if (devnode != NULL && strcmp(devnode_old, devnode) != 0) - update_link(dev, devnode_old, test); + info(udev, "update old name, '%s' no longer belonging to '%s'\n", + name, udev_device_get_devpath(dev)); + link_update(dev, name, 0); } } -int udev_node_add(struct udev_device *dev, mode_t mode, uid_t uid, gid_t gid, int test) +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; @@ -419,45 +350,41 @@ int udev_node_add(struct udev_device *dev, mode_t mode, uid_t uid, gid_t gid, in major(udev_device_get_devnum(dev)), minor(udev_device_get_devnum(dev)), mode, uid, gid); - util_create_path(udev, udev_device_get_devnode(dev)); - if (!test) - if (udev_node_mknod(dev, NULL, makedev(0,0), mode, uid, gid) != 0) { - err = -1; - goto exit; - } + if (udev_node_mknod(dev, NULL, makedev(0,0), 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); - if (!test) { - 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); - } + 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); } } - /* add node to name index */ - name_index(udev, udev_device_get_devpath(dev), udev_device_get_devnode(dev), 1, test); - /* create/update symlinks, add symlinks to name index */ udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev)) { - name_index(udev, udev_device_get_devpath(dev), udev_list_entry_get_name(list_entry), 1, test); - update_link(dev, udev_list_entry_get_name(list_entry), test); + if (udev_list_entry_get_flag(list_entry)) + /* simple unmanaged link name */ + node_symlink(udev, udev_device_get_devnode(dev), udev_list_entry_get_name(list_entry)); + else + link_update(dev, udev_list_entry_get_name(list_entry), 1); } exit: return err; } -extern int udev_node_remove(struct udev_device *dev, int test) +int udev_node_remove(struct udev_device *dev) { struct udev *udev = udev_device_get_udev(dev); struct udev_list_entry *list_entry; @@ -467,14 +394,9 @@ extern int udev_node_remove(struct udev_device *dev, int test) int err = 0; int num; - /* remove node from name index */ - name_index(udev, udev_device_get_devpath(dev), udev_device_get_devnode(dev), 0, test); - /* remove,update symlinks, remove symlinks from name index */ - udev_list_entry_foreach(list_entry, udev_device_get_devlinks_list_entry(dev)) { - name_index(udev, udev_device_get_devpath(dev), udev_list_entry_get_name(list_entry), 0, test); - update_link(dev, udev_list_entry_get_name(list_entry), test); - } + 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) @@ -489,8 +411,7 @@ extern int udev_node_remove(struct udev_device *dev, int test) } info(udev, "removing device node '%s'\n", devnode); - if (!test) - err = util_unlink_secure(udev, devnode); + err = util_unlink_secure(udev, devnode); if (err) return err; @@ -504,8 +425,7 @@ extern int udev_node_remove(struct udev_device *dev, int test) for (i = 1; i <= num; i++) { snprintf(partitionname, sizeof(partitionname), "%s%d", devnode, i); partitionname[sizeof(partitionname)-1] = '\0'; - if (!test) - util_unlink_secure(udev, partitionname); + util_unlink_secure(udev, partitionname); } } util_delete_path(udev, devnode);