[patch] cleanup ttyname and make it devfs friendly

[Ben Collins <bcollins at debian dot org>]

This is due to popular demand since ttyname doesn't work with sgid apps
with devfs only systems. Since I had to add /dev/vc/ to the list of
directories to search, I figured I'd clean things up a bit to make it
easier to read. Tested with current CVS.

2001-10-29  Ben Collins  <bcollins@debian.org>

	* sysdeps/unix/sysv/linux/ttyname.c(getttyname): Take a single
	struct stat64* for an arg, so we can do all the work out the
	_STATBUF_ST_RDEV in one place.
	(ttyname): Update usage of getttyname(). Also cleanup the checks
	for /dev/<subdir> searches and add /dev/vc/ to the search for
	devfs only systems.
	* sysdeps/unix/sysv/linux/ttyname_r.c: Likewise.

-- 
 .----------=======-=-======-=========-----------=====------------=-=-----.
/                   Ben Collins    --    Debian GNU/Linux                  \
`  bcollins@debian.org  --  bcollins@openldap.org  --  bcollins@linux.com  '
 `---=========------=======-------------=-=-----=-===-======-------=--=---'
--- sysdeps/unix/sysv/linux/ttyname_r.c~	2001/07/06 04:56:13	1.14
+++ sysdeps/unix/sysv/linux/ttyname_r.c	2001/10/29 19:25:38
@@ -28,21 +28,24 @@
 
 #include <stdio-common/_itoa.h>
 
-static int getttyname_r (char *buf, size_t buflen,
-			 dev_t mydev, ino64_t myino, int save,
+static int getttyname_r (const char *prefix, char *buf, size_t buflen,
+			 struct stat64 *mystat, int save,
 			 int *dostat) internal_function;
 
 static int
 internal_function
-getttyname_r (char *buf, size_t buflen, dev_t mydev, ino64_t myino,
+getttyname_r (const char *prefix, char *buf, size_t buflen, struct stat64 *mystat,
 	      int save, int *dostat)
 {
   struct stat64 st;
   DIR *dirstream;
   struct dirent64 *d;
-  size_t devlen = strlen (buf);
+  size_t devlen = strlen (prefix);
 
-  dirstream = __opendir (buf);
+  memcpy (buf, prefix, strlen (prefix));
+  buflen -= strlen (prefix) - 1;
+
+  dirstream = __opendir (prefix);
   if (dirstream == NULL)
     {
       *dostat = -1;
@@ -50,7 +53,7 @@
     }
 
   while ((d = __readdir64 (dirstream)) != NULL)
-    if ((d->d_fileno == myino || *dostat)
+    if ((d->d_fileno == mystat->st_ino || *dostat)
 	&& strcmp (d->d_name, "stdin")
 	&& strcmp (d->d_name, "stdout")
 	&& strcmp (d->d_name, "stderr"))
@@ -71,9 +74,9 @@
 
 	if (__xstat64 (_STAT_VER, buf, &st) == 0
 #ifdef _STATBUF_ST_RDEV
-	    && S_ISCHR (st.st_mode) && st.st_rdev == mydev
+	    && S_ISCHR (st.st_mode) && st.st_rdev == mystat->st_rdev
 #else
-	    && d->d_fileno == myino && st.st_dev == mydev
+	    && d->d_fileno == mystat->st_ino && st.st_dev == mystat->st_dev
 #endif
 	   )
 	  {
@@ -99,7 +102,8 @@
   struct stat64 st, st1;
   int dostat = 0;
   int save = errno;
-  int ret;
+  int ret, i;
+  const char *dirs[] = { "/dev/pts/", "/dev/vc/", "/dev/tts/", 0 };
 
   /* Test for the absolute minimal size.  This makes life easier inside
      the loop.  */
@@ -139,50 +143,24 @@
   if (__fxstat64 (_STAT_VER, fd, &st) < 0)
     return errno;
 
-  /* Prepare the result buffer.  */
-  memcpy (buf, "/dev/pts/", sizeof ("/dev/pts/"));
-  buflen -= sizeof ("/dev/pts/") - 1;
+  ret = ENOTTY;
 
-  if (__xstat64 (_STAT_VER, buf, &st1) == 0 && S_ISDIR (st1.st_mode))
-    {
-#ifdef _STATBUF_ST_RDEV
-      ret = getttyname_r (buf, buflen, st.st_rdev, st.st_ino, save,
-			  &dostat);
-#else
-      ret = getttyname_r (buf, buflen, st.st_dev, st.st_ino, save,
-			  &dostat);
-#endif
-    }
-  else
+  for (i = 0; ret && dirs[i]; i++)
     {
-      __set_errno (save);
-      ret = ENOENT;
+      if (__xstat64 (_STAT_VER, dirs[i], &st1) == 0 && S_ISDIR (st1.st_mode))
+	ret = getttyname_r (dirs[i], buf, buflen, &st, save, &dostat);
+      else
+	__set_errno (save);
     }
 
+
   if (ret && dostat != -1)
-    {
-      buf[sizeof ("/dev/") - 1] = '\0';
-      buflen += sizeof ("pts/") - 1;
-#ifdef _STATBUF_ST_RDEV
-      ret = getttyname_r (buf, buflen, st.st_rdev, st.st_ino, save,
-			  &dostat);
-#else
-      ret = getttyname_r (buf, buflen, st.st_dev, st.st_ino, save,
-			  &dostat);
-#endif
-    }
+    ret = getttyname_r ("/dev/", buf, buflen, &st, save, &dostat);
 
   if (ret && dostat != -1)
     {
-      buf[sizeof ("/dev/") - 1] = '\0';
       dostat = 1;
-#ifdef _STATBUF_ST_RDEV
-      ret = getttyname_r (buf, buflen, st.st_rdev, st.st_ino,
-			  save, &dostat);
-#else
-      ret = getttyname_r (buf, buflen, st.st_dev, st.st_ino,
-			  save, &dostat);
-#endif
+      ret = getttyname_r ("/dev/", buf, buflen, &st, save, &dostat);
     }
 
   return ret;
--- sysdeps/unix/sysv/linux/ttyname.c~	2001/07/06 04:56:13	1.16
+++ sysdeps/unix/sysv/linux/ttyname.c	2001/10/29 19:25:38
@@ -30,8 +30,8 @@
 
 char *__ttyname;
 
-static char *getttyname (const char *dev, dev_t mydev,
-			 ino64_t myino, int save, int *dostat)
+static char *getttyname (const char *dev, struct stat64 *mystat,
+			 int save, int *dostat)
      internal_function;
 
 
@@ -39,7 +39,7 @@
 
 static char *
 internal_function
-getttyname (const char *dev, dev_t mydev, ino64_t myino, int save, int *dostat)
+getttyname (const char *dev, struct stat64 *mystat, int save, int *dostat)
 {
   static size_t namelen;
   struct stat64 st;
@@ -55,7 +55,7 @@
     }
 
   while ((d = __readdir64 (dirstream)) != NULL)
-    if ((d->d_fileno == myino || *dostat)
+    if ((d->d_fileno == mystat->st_ino || *dostat)
 	&& strcmp (d->d_name, "stdin")
 	&& strcmp (d->d_name, "stdout")
 	&& strcmp (d->d_name, "stderr"))
@@ -78,9 +78,9 @@
 	memcpy (&getttyname_name[devlen], d->d_name, dlen);
 	if (__xstat64 (_STAT_VER, getttyname_name, &st) == 0
 #ifdef _STATBUF_ST_RDEV
-	    && S_ISCHR (st.st_mode) && st.st_rdev == mydev
+	    && S_ISCHR (st.st_mode) && st.st_rdev == mystat->st_rdev
 #else
-	    && d->d_fileno == myino && st.st_dev == mydev
+	    && d->d_fileno == mystat->st_ino && st.st_dev == mystat->st_dev
 #endif
 	   )
 	  {
@@ -110,9 +110,10 @@
   char procname[30];
   struct stat64 st, st1;
   int dostat = 0;
-  char *name;
+  char *name = NULL;
   int save = errno;
-  int len;
+  int len, i;
+  const char *dirs[] = { "/dev/pts", "/dev/vc", "/dev/tts", 0 };
 
   if (!__isatty (fd))
     return NULL;
@@ -146,37 +147,21 @@
   if (__fxstat64 (_STAT_VER, fd, &st) < 0)
     return NULL;
 
-  if (__xstat64 (_STAT_VER, "/dev/pts", &st1) == 0 && S_ISDIR (st1.st_mode))
+  for (i = 0; !name && dirs[i]; i++)
     {
-#ifdef _STATBUF_ST_RDEV
-      name = getttyname ("/dev/pts", st.st_rdev, st.st_ino, save, &dostat);
-#else
-      name = getttyname ("/dev/pts", st.st_dev, st.st_ino, save, &dostat);
-#endif
+      if (__xstat64 (_STAT_VER, dirs[i], &st1) == 0 && S_ISDIR (st1.st_mode))
+	name = getttyname (dirs[i], &st, save, &dostat);
+      else
+	__set_errno (save);
     }
-  else
-    {
-      __set_errno (save);
-      name = NULL;
-    }
-
+  
   if (!name && dostat != -1)
-    {
-#ifdef _STATBUF_ST_RDEV
-      name = getttyname ("/dev", st.st_rdev, st.st_ino, save, &dostat);
-#else
-      name = getttyname ("/dev", st.st_dev, st.st_ino, save, &dostat);
-#endif
-    }
+    name = getttyname ("/dev", &st, save, &dostat);
 
   if (!name && dostat != -1)
     {
       dostat = 1;
-#ifdef _STATBUF_ST_RDEV
-      name = getttyname ("/dev", st.st_rdev, st.st_ino, save, &dostat);
-#else
-      name = getttyname ("/dev", st.st_dev, st.st_ino, save, &dostat);
-#endif
+      name = getttyname ("/dev", &st, save, &dostat);
     }
 
   return name;