PERFORCE change 122077 for review

[Roman Divacky]

http://perforce.freebsd.org/chv.cgi?CH=122077

Change 122077 by rdivacky at rdivacky_witten on 2007/06/21 10:00:59

	Introduce kern_absolute_path which checks whether a given path is absolute or
	not by checking first char for being '/'.
	
	Use this function to implement BADF semantic of *at syscalls.

Affected files ...

.. //depot/projects/soc2007/rdivacky/linux_at/sys/kern/vfs_syscalls.c#21 edit

Differences ...

==== //depot/projects/soc2007/rdivacky/linux_at/sys/kern/vfs_syscalls.c#21 (text+ko) ====

@@ -88,6 +88,7 @@
 static int kern_get_at(struct thread *td, int dirfd, struct vnode **dir_vn);
 static int vn_access(struct vnode *vp, int user_flags, struct ucred *cred,
     struct thread *td);
+static int kern_absolute_path(char *path, enum uio_seg pathseg);
 
 /*
  * The module initialization routine for POSIX asynchronous I/O will
@@ -981,6 +982,22 @@
 	return (0);
 }
 
+/* Check whether a path is an absolute path. */
+static int kern_absolute_path(char *path, enum uio_seg pathseg)
+{
+	int error, len;
+	char buf[PATH_MAX];
+
+	if (pathseg == UIO_SYSSPACE) {
+		return (path[0] == '/');		
+	} else {
+		error = copyinstr(path, buf, PATH_MAX, &len);
+		if (error)
+			return 1;	/* we want to fail */
+		return (buf[0] == '/');	
+	}
+}
+
 int
 kern_openat(struct thread *td, char *path, enum uio_seg pathseg, int flags,
     int mode, int dirfd)
@@ -1004,7 +1021,7 @@
 	/* XXX: audit dirfd */
 
 	error = kern_get_at(td, dirfd, &dir_vn);
-	if (error)
+	if (error && !kern_absolute_path(path, pathseg))
 		return (error);
 
 	NDINIT_AT(&nd, LOOKUP, FOLLOW | AUDITVNODE1 | MPSAFE, pathseg, path, td, dir_vn);
@@ -1221,7 +1238,7 @@
 	if (dir_vn)
 		vrele(dir_vn);
 	error = kern_get_at(td, dirfd, &dir_vn);
-	if (error)
+	if (error && !kern_absolute_path(path, pathseg))
 		return (error);
 	bwillwrite();
 	NDINIT_AT(&nd, CREATE, LOCKPARENT | SAVENAME | MPSAFE | AUDITVNODE1,
@@ -1348,7 +1365,7 @@
 	if (dir_vn)
 		vrele(dir_vn);
 	error = kern_get_at(td, dirfd, &dir_vn);
-	if (error)
+	if (error && !kern_absolute_path(path, pathseg))
 		return (error);
 	bwillwrite();
 	NDINIT_AT(&nd, CREATE, LOCKPARENT | SAVENAME | MPSAFE | AUDITVNODE1,
@@ -1490,13 +1507,13 @@
 	int lvfslocked;
 
 	error = kern_get_at(td, olddirfd, &pdir_vn);
-	if (error)
+	if (error && !kern_absolute_path(path, segflg))
 		return (error);
 
 	NDINIT_AT(&ndp, LOOKUP, FOLLOW | MPSAFE | AUDITVNODE1, segflg, path, td, pdir_vn);
 
 	error = kern_get_at(td, newdirfd, &ldir_vn);
-	if (error)
+	if (error && !kern_absolute_path(link, segflg))
 		return (error);
 
 	NDINIT_AT(&ndl, CREATE, LOCKPARENT | SAVENAME| MPSAFE | AUDITVNODE1, segflg,
@@ -1609,7 +1626,7 @@
 	if (dir_vn)
 		vrele(dir_vn);
 	error = kern_get_at(td, dirfd, &dir_vn);
-	if (error)
+	if (error && !kern_absolute_path(link, segflg))
 		return (error);
 	bwillwrite();
 	NDINIT_AT(&nd, CREATE, LOCKPARENT | SAVENAME | MPSAFE | AUDITVNODE1,
@@ -1758,7 +1775,7 @@
 	if (dir_vn)
 		vrele(dir_vn);
 	error = kern_get_at(td, dirfd, &dir_vn);
-	if (error)
+	if (error && !kern_absolute_path(path, pathseg))
 		return (error);
 	bwillwrite();
 	NDINIT_AT(&nd, DELETE, LOCKPARENT | LOCKLEAF | MPSAFE | AUDITVNODE1,
@@ -2032,7 +2049,7 @@
 	int vfslocked;
 
 	error = kern_get_at(td, dirfd, &dir_vn);
-	if (error)
+	if (error && !kern_absolute_path(path, pathseg))
 		return (error);
 
 	NDINIT_AT(&nd, LOOKUP, FOLLOW | LOCKLEAF | MPSAFE | AUDITVNODE1,
@@ -2242,7 +2259,7 @@
 	int error, vfslocked;
 
 	error = kern_get_at(td, dirfd, &dir_vn);
-	if (error)
+	if (error && !kern_absolute_path(path, pathseg))
 		return (error);
 
 	NDINIT_AT(&nd, LOOKUP, FOLLOW | LOCKSHARED | LOCKLEAF | AUDITVNODE1 | 
@@ -2311,7 +2328,7 @@
 	int error, vfslocked;
 
 	error = kern_get_at(td, dirfd, &dir_vn);
-	if (error)
+	if (error && !kern_absolute_path(path, pathseg))
 		return (error);
 
 	NDINIT_AT(&nd, LOOKUP, NOFOLLOW | LOCKLEAF | LOCKSHARED | AUDITVNODE1 | 
@@ -2504,7 +2521,7 @@
 	int error, vfslocked;
 
 	error = kern_get_at(td, dirfd, &dir_vn);
-	if (error)
+	if (error && !kern_absolute_path(path, pathseg))
 		return (error);
 
 	NDINIT_AT(&nd, LOOKUP, NOFOLLOW | LOCKLEAF | MPSAFE | AUDITVNODE1, pathseg,
@@ -2751,7 +2768,7 @@
 	int error, vfslocked;
 
 	error = kern_get_at(td, dirfd, &dir_vn);
-	if (error)
+	if (error && !kern_absolute_path(path, pathseg))
 		return (error);
 
 	NDINIT_AT(&nd, LOOKUP, FOLLOW | MPSAFE | AUDITVNODE1, pathseg, path, td, dir_vn);
@@ -2911,7 +2928,7 @@
 	int error, vfslocked;
 
 	error = kern_get_at(td, dirfd, &dir_vn);
-	if (error)
+	if (error && !kern_absolute_path(path, pathseg))
 		return (error);
 
 	NDINIT_AT(&nd, LOOKUP, FOLLOW | MPSAFE | AUDITVNODE1, pathseg, path, td, dir_vn);
@@ -2968,7 +2985,7 @@
 	int error, vfslocked;
 
 	error = kern_get_at(td, dirfd, &dir_vn);
-	if (error)
+	if (error && !kern_absolute_path(path, pathseg))
 		return (error);
 
 	NDINIT_AT(&nd, LOOKUP, NOFOLLOW | MPSAFE | AUDITVNODE1, pathseg, path, td, dir_vn);
@@ -3142,7 +3159,7 @@
 	int error, vfslocked;
 
    	error = kern_get_at(td, dirfd, &dir_vn);
-	if (error)
+	if (error && !kern_absolute_path(path, pathseg))
 		return (error);
 
 	NDINIT_AT(&nd, LOOKUP, FOLLOW | AUDITVNODE1 | MPSAFE, pathseg, path, td, dir_vn);
@@ -3524,10 +3541,10 @@
 	int error;
 
 	error = kern_get_at(td, fdirfd, &fdir_vn);
-	if (error)
+	if (error && !kern_absolute_path(from, pathseg))
 		return (error);
 	error = kern_get_at(td, tdirfd, &tdir_vn);
-	if (error)
+	if (error && !kern_absolute_path(to, pathseg))
 		return (error);
 
 #ifdef MAC
@@ -3683,7 +3700,7 @@
 	if (dir_vn)
 		vrele(dir_vn);
 	error = kern_get_at(td, dirfd, &dir_vn);
-	if (error)
+	if (error && !kern_absolute_path(path, segflg))
 		return (error);
 	bwillwrite();
 	NDINIT_AT(&nd, CREATE, LOCKPARENT | SAVENAME | MPSAFE | AUDITVNODE1,
@@ -3787,7 +3804,7 @@
 
 restart:
 	error = kern_get_at(td, dirfd, &dir_vn);
-	if (error)
+	if (error && !kern_absolute_path(path, pathseg))
 		return (error);
 	bwillwrite();
 	NDINIT_AT(&nd, DELETE, LOCKPARENT | LOCKLEAF | MPSAFE | AUDITVNODE1,