diff options
| -rw-r--r-- | lib/libc/gen/devname.c | 88 |
1 files changed, 63 insertions, 25 deletions
diff --git a/lib/libc/gen/devname.c b/lib/libc/gen/devname.c index 8916540e3d8..824eedefcf0 100644 --- a/lib/libc/gen/devname.c +++ b/lib/libc/gen/devname.c @@ -1,4 +1,4 @@ -/* $OpenBSD: devname.c,v 1.9 2015/07/14 19:05:11 millert Exp $ */ +/* $OpenBSD: devname.c,v 1.10 2015/07/14 19:05:52 millert Exp $ */ /* * Copyright (c) 1989, 1993 * The Regents of the University of California. All rights reserved. @@ -28,44 +28,82 @@ * SUCH DAMAGE. */ +#include <sys/stat.h> #include <sys/types.h> #include <db.h> -#include <err.h> -#include <errno.h> +#include <dirent.h> #include <fcntl.h> +#include <limits.h> #include <paths.h> +#include <stdbool.h> #include <stdio.h> #include <string.h> #include <stdlib.h> +static char * +devname_nodb(dev_t dev, mode_t type) +{ + static char buf[sizeof(_PATH_DEV) + NAME_MAX]; + char *name = NULL; + struct dirent *dp; + struct stat sb; + DIR *dirp; + + if ((dirp = opendir(_PATH_DEV)) == NULL) + return (NULL); + if (strlcpy(buf, _PATH_DEV, sizeof(buf)) >= sizeof(buf)) + return (NULL); + while ((dp = readdir(dirp)) != NULL) { + if (dp->d_type != DT_UNKNOWN && DTTOIF(dp->d_type) != type) + continue; + buf[sizeof(_PATH_DEV) - 1] = '\0'; + if (strlcat(buf, dp->d_name, sizeof(buf)) >= sizeof(buf)) + continue; + if (lstat(buf, &sb) == -1) + continue; + if (sb.st_rdev != dev || (sb.st_mode & S_IFMT) != type) + continue; + name = buf + sizeof(_PATH_DEV) - 1; + break; + } + closedir(dirp); + return (name); +} + +/* + * Keys in dev.db are a mode_t followed by a dev_t. The former is the + * type of the file (mode & S_IFMT), the latter is the st_rdev field. + * Note that the structure may contain padding. + */ +struct { + mode_t type; + dev_t dev; +} bkey; + char * devname(dev_t dev, mode_t type) { - struct { - mode_t type; - dev_t dev; - } bkey; static DB *db; - static int failure; + static bool failure; DBT data, key; + char *name = NULL; - if (!db && !failure && - !(db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL))) { - failure = 1; + if (!db && !failure) { + if (!(db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL))) + failure = true; } - if (failure) - return ("??"); - - /* - * Keys are a mode_t followed by a dev_t. The former is the type of - * the file (mode & S_IFMT), the latter is the st_rdev field. Be - * sure to clear any padding that may be found in bkey. - */ - memset(&bkey, 0, sizeof(bkey)); - bkey.dev = dev; - bkey.type = type; - key.data = &bkey; - key.size = sizeof(bkey); - return ((db->get)(db, &key, &data, 0) ? "??" : (char *)data.data); + if (!failure) { + /* Be sure to clear any padding that may be found in bkey. */ + memset(&bkey, 0, sizeof(bkey)); + bkey.dev = dev; + bkey.type = type; + key.data = &bkey; + key.size = sizeof(bkey); + if ((db->get)(db, &key, &data, 0) == 0) + name = data.data; + } else { + name = devname_nodb(dev, type); + } + return (name ? name : "??"); } |