Add devname_r(3) which takes a buffer as argument.

3 files changed, 22 insertions, 56 deletions

diff --git a/include/stdlib.h b/include/stdlib.h
index 4bbd438..5895e19 100644
--- a/include/stdlib.h
+++ b/include/stdlib.h
@@ -258,6 +258,7 @@ int	 cgetustr(char *, const char *, char **);
 
 int	 daemon(int, int);
 char	*devname(int, int);
+char 	*devname_r(int, int, char *buf, int len);
 int	 getloadavg(double [], int);
 __const char *
 	 getprogname(void);
diff --git a/lib/libc/gen/devname.3 b/lib/libc/gen/devname.3
index 83952dc..f25e7da 100644
--- a/lib/libc/gen/devname.3
+++ b/lib/libc/gen/devname.3
@@ -45,6 +45,8 @@
 .In stdlib.h
 .Ft char *
 .Fn devname "dev_t dev" "mode_t type"
+.Ft char *
+.Fn devname_r "dev_t dev" "mode_t type" "char *buf" "int len"
 .Sh DESCRIPTION
 The
 .Fn devname
@@ -61,27 +63,25 @@ or
 .Dv S_IFCHR .
 To find the right name,
 .Fn devname
-first searches the device database created by
-.Xr dev_mkdb 8 ;
-if that fails, it asks the kernel via the
+asks the kernel via the
 .Va kern.devname
 sysctl.
-If it was still unable to come up with a suitable name,
+If it is unable to come up with a suitable name,
 it will format the information encapsulated in
 .Fa dev
 and
 .Fa type
 in a human-readable format.
+.Pp
+.Fn devname
+returns the name stored in a static buffer which will be overwritten
+on subsequent calls.
+.Fn devname_r
+takes a buffer and length as argument to avoid this problem.
 .Sh SEE ALSO
 .Xr stat 2 ,
-.Xr dev_mkdb 8
 .Sh HISTORY
 The
 .Fn devname
 function appeared in
 .Bx 4.4 .
-.Sh BUGS
-The
-.Fn devname
-function returns a pointer to an internal static object;
-thus, subsequent calls will modify the same buffer.
diff --git a/lib/libc/gen/devname.c b/lib/libc/gen/devname.c
index bd9ac41..ca0d6a9 100644
--- a/lib/libc/gen/devname.c
+++ b/lib/libc/gen/devname.c
@@ -40,65 +40,22 @@ __FBSDID("$FreeBSD$");
 #include <sys/types.h>
 #include <sys/sysctl.h>
 
-#include <db.h>
 #include <err.h>
 #include <fcntl.h>
-#include <paths.h>
 #include <stdio.h>
 #include <string.h>
 #include <sys/param.h>
 #include <sys/stat.h>
 
-static char *
-xdevname(dev, type)
-	dev_t dev;
-	mode_t type;
-{
-	struct {
-		mode_t type;
-		dev_t dev;
-	} bkey;
-	static DB *db;
-	static int failure;
-	DBT data, key;
-
-	if (!db && !failure &&
-	    !(db = dbopen(_PATH_DEVDB, O_RDONLY, 0, DB_HASH, NULL))) 
-		failure = 1;
-	if (failure)
-		return (NULL);
-
-	/*
-	 * 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) ? NULL : (char *)data.data);
-}
-
 char *
-devname(dev, type)
-	dev_t dev;
-	mode_t type;
+devname_r(dev_t dev, mode_t type, char *buf, int len)
 {
-	static char buf[SPECNAMELEN + 1];
 	int i;
 	size_t j;
 	char *r;
 
-	/* First check the DB file. */
-	r = xdevname(dev, type);
-	if (r != NULL)
-		return (r);
-
-	/* Then ask the kernel. */
 	if ((type & S_IFMT) == S_IFCHR) {
-		j = sizeof(buf);
+		j = len;
 		i = sysctlbyname("kern.devname", buf, &j, &dev, sizeof (dev));
 		if (i == 0)
 		    return (buf);
@@ -109,7 +66,15 @@ devname(dev, type)
 		r = "#NODEV";
 	else 
 		r = "#%c:%d:0x%x";
-	snprintf(buf, SPECNAMELEN + 1, r,
+	snprintf(buf, len, r,
 	    (type & S_IFMT) == S_IFCHR ? 'C' : 'B', major(dev), minor(dev));
 	return (buf);
 }
+
+char *
+devname(dev_t dev, mode_t type)
+{
+	static char buf[SPECNAMELEN + 1];
+
+	return(devname_r(dev, type, buf, sizeof(buf)));
+}