X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udev_node.c;h=b1bbda8369c3e264e86b583015d122e1299f96fe;hp=1632c2cc3ce8823a27deeaece3c3cc6618c02b11;hb=4a86b682ab3f0473a24ef66d56db100eb592a9bb;hpb=456cb387567da8a2beadf003dcbd874022dbc873 diff --git a/udev_node.c b/udev_node.c index 1632c2cc3..b1bbda836 100644 --- a/udev_node.c +++ b/udev_node.c @@ -25,6 +25,7 @@ #include #include #include +#include #include #include @@ -43,7 +44,7 @@ int udev_node_mknod(struct udevice *udev, const char *file, dev_t devt, mode_t m else mode |= S_IFCHR; - if (stat(file, &stats) != 0) + if (lstat(file, &stats) != 0) goto create; /* preserve node with already correct numbers, to prevent changing the inode number */ @@ -114,7 +115,7 @@ static int node_symlink(const char *node, const char *slink) if (len > 0) { buf[len] = '\0'; if (strcmp(target, buf) == 0) { - info("preserving symlink '%s' to '%s'", slink, target); + info("preserve already existing symlink '%s' to '%s'", slink, target); selinux_setfilecon(slink, NULL, S_IFLNK); goto exit; } @@ -133,7 +134,137 @@ exit: return 0; } -int udev_node_add(struct udevice *udev, struct udevice *udev_old) +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'", count, name); + + /* if we don't have a reference, delete it */ + if (count <= 0) { + info("no reference left, remove '%s'", 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'", 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", + udev->dev->devpath, udev->link_priority, priority); + if (target[0] == '\0' || udev->link_priority >= priority) { + priority = udev->link_priority; + strlcpy(target, udev->name, sizeof(target)); + } + continue; + } + + /* or something else, then 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) { + info("compare priority of '%s' %i > %i", + 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') { + err("missing target for '%s'", 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", 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'", 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'", + 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; @@ -141,10 +272,9 @@ int udev_node_add(struct udevice *udev, struct udevice *udev_old) int i; int retval = 0; - snprintf(filename, sizeof(filename), "%s/%s", udev_root, udev->name); - filename[sizeof(filename)-1] = '\0'; - - /* create parent directories if needed */ + 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) @@ -209,114 +339,21 @@ int udev_node_add(struct udevice *udev, struct udevice *udev_old) } } } - - /* create symlink(s) if requested */ - if (!list_empty(&udev->symlink_list)) { - struct name_entry *name_loop; - char symlinks[PATH_SIZE] = ""; - - list_for_each_entry(name_loop, &udev->symlink_list, node) { - char slink[PATH_SIZE]; - - strlcpy(slink, udev_root, sizeof(slink)); - strlcat(slink, "/", sizeof(slink)); - strlcat(slink, name_loop->name, sizeof(slink)); - - info("creating symlink '%s' to node '%s'", slink, filename); - if (!udev->test_run) { - create_path(slink); - node_symlink(filename, slink); - } - - strlcat(symlinks, slink, sizeof(symlinks)); - strlcat(symlinks, " ", sizeof(symlinks)); - } - - remove_trailing_chars(symlinks, ' '); - setenv("DEVLINKS", symlinks, 1); - } - exit: return retval; } -void udev_node_remove_symlinks(struct udevice *udev) -{ - char filename[PATH_SIZE]; - struct name_entry *name_loop; - struct stat stats; - - if (!list_empty(&udev->symlink_list)) { - char symlinks[PATH_SIZE] = ""; - - list_for_each_entry(name_loop, &udev->symlink_list, node) { - char devpath[PATH_SIZE]; - - 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); - if (!udev->test_run) { - unlink(filename); - delete_path(filename); - } - - /* see if another device wants this symlink */ - if (udev_db_lookup_name(name_loop->name, devpath, sizeof(devpath)) == 0) { - struct udevice *old; - - info("found overwritten symlink '%s' of '%s'", name_loop->name, devpath); - old = udev_device_init(); - if (old != NULL) { - if (udev_db_get_device(old, devpath) == 0) { - char slink[PATH_SIZE]; - char node[PATH_SIZE]; - - strlcpy(slink, udev_root, sizeof(slink)); - strlcat(slink, "/", sizeof(slink)); - strlcat(slink, name_loop->name, sizeof(slink)); - strlcpy(node, udev_root, sizeof(node)); - strlcat(node, "/", sizeof(node)); - strlcat(node, old->name, sizeof(node)); - info("restore symlink '%s' to '%s'", slink, node); - if (!udev->test_run) - node_symlink(node, slink); - } - udev_device_cleanup(old); - } - } - - strlcat(symlinks, filename, sizeof(symlinks)); - strlcat(symlinks, " ", sizeof(symlinks)); - } - - remove_trailing_chars(symlinks, ' '); - if (symlinks[0] != '\0') - setenv("DEVLINKS", symlinks, 1); - } -} - int udev_node_remove(struct udevice *udev) { char filename[PATH_SIZE]; char partitionname[PATH_SIZE]; struct stat stats; - int retval; + int retval = 0; int num; - udev_node_remove_symlinks(udev); - - snprintf(filename, sizeof(filename), "%s/%s", udev_root, udev->name); - filename[sizeof(filename)-1] = '\0'; + strlcpy(filename, udev_root, sizeof(filename)); + strlcat(filename, "/", sizeof(filename)); + strlcat(filename, udev->name, sizeof(filename)); if (stat(filename, &stats) != 0) { dbg("device node '%s' not found", filename); return -1; @@ -327,7 +364,8 @@ int udev_node_remove(struct udevice *udev) } info("removing device node '%s'", filename); - retval = unlink_secure(filename); + if (!udev->test_run) + retval = unlink_secure(filename); if (retval) return retval; @@ -337,14 +375,13 @@ int udev_node_remove(struct udevice *udev) int i; info("removing all_partitions '%s[1-%i]'", filename, num); - if (num > 255) { - info("garbage from udev database, skip all_partitions removal"); + if (num > 255) 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 (!udev->test_run) + unlink_secure(partitionname); } } delete_path(filename);