Much simpler and safer ttyname() using B_GET_PATH_FOR_DEVICE. Also added ttyname_r for which we had a proto in the headers.

git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@20133 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/system/kernel/fs/devfs.cpp

@@ -1616,6 +1616,8 @@ devfs_ioctl(fs_volume _fs, fs_vnode _vnode, fs_cookie _cookie, ulong op,
 				 */
 				strcpy(path, "/dev/");
 				get_device_name(vnode, path + 5, sizeof(path) - 5);
+				if (length && (length <= strlen(path)))
+					return ERANGE;
 				return user_strlcpy((char *)buffer, path, sizeof(path));
 			}
 

src/system/libroot/posix/unistd/ttyname.c

@@ -1,78 +1,59 @@
 /* 
 ** Copyright 2003, Daniel Reinhold, [email protected]. All rights reserved.
+** Copyright 2007, François Revol, [email protected]. All rights reserved.
 ** Distributed under the terms of the OpenBeOS License.
 */
 
 
 #include <SupportDefs.h>
+#include <Drivers.h>
 
+#include <errno.h>
 #include <stdio.h>
 #include <string.h>
 #include <unistd.h>
-#include <dirent.h>
 #include <sys/stat.h>
 #include <sys/param.h>
 
-
+/**
-/* the root directory in /dev where all tty devices reside */
+ * give the name of a tty fd. threadsafe.
-#define DEV_TTY  "/dev/tt/"
+ * @param fd the tty to get the name from.
-
+ * @param buffer where to store the name to.
-
+ * @param bufferSize length of the buffer.
-/** return the full pathname of the tty device
+ * @return 0 on success, -1 on error, sets errno.
- *	(NULL if not a tty or an error occurs)
  */
+int
+ttyname_r(int fd, char *buffer, size_t bufferSize)
+{
+	struct stat fdStat;
+	int err;
 
+	// first, some sanity checks:
+	if (fstat(fd, &fdStat) < 0)
+		return -1;
+
+	if (!S_ISCHR(fdStat.st_mode) || !isatty(fd)) {
+		errno = ENOTTY;
+		return ENOTTY;
+	}
+
+	// just ask devfs
+	return ioctl(fd, B_GET_PATH_FOR_DEVICE, name, namesize);
+}
+
+
+/**
+ * give the name of a tty fd.
+ * @param fd the tty to get the name from.
+ * @return the name of the tty or NULL on error.
+ */
 char *
 ttyname(int fd)
 {
 	static char pathname[MAXPATHLEN];
-	char  *stub = pathname + sizeof(DEV_TTY) - 1;
-	int   stubLen = sizeof(pathname) - sizeof(DEV_TTY);
-	struct stat fdStat;
-	DIR   *dir;
-	bool  found = false;
 
-	// first, some sanity checks:
+	int err = ttyname_r(fd, pathname, sizeof(pathname));
-	if (!isatty(fd))
+	if (err < 0)
 		return NULL;
-
+	return pathname;
-	if (fstat(fd, &fdStat) < 0)
-		return NULL;
-
-	if (!S_ISCHR(fdStat.st_mode))
-		return NULL;
-
-	// start with the root tty directory at /dev
-	strcpy(pathname, DEV_TTY);
-
-	if ((dir = opendir(pathname)) != NULL) {
-		// find a matching entry in the directory:
-		//   we must match both the inode for the file 
-		//   and the device that the file resides on
-		struct dirent *e;
-		struct stat entryStat;
-
-		while ((e = readdir(dir)) != NULL) {
-			// try to match the file's inode
-			if (e->d_ino != fdStat.st_ino)
-				continue;
-
-			// construct the entry's full filename and
-			// call stat() to retrieve the inode info
-			strncpy(stub, e->d_name, stubLen);
-
-			if (stat(pathname, &entryStat) < 0)
-				continue;
-
-			if (entryStat.st_ino == fdStat.st_ino &&
-			    entryStat.st_dev == fdStat.st_dev) {
-			    found = true;
-			    break;
-			}
-		}
-
-		closedir(dir);
-	}
-
-	return found ? pathname : NULL;
 }