openat: make template easier to use

* lib/at-func.c (CALL_FUNC): Allow AT_FUNC_USE_F1_COND and
AT_FUNC_F2 to be undefined.
(VALIDATE_FLAG): New macro; use it to reject bad flags.
(AT_FUNC_USE_F1_COND): Change sense to just flag bit.
* lib/fchmodat.c (AT_FUNC_USE_F1_COND): Adjust.
* lib/fchownat.c (AT_FUNC_USE_F1_COND): Likewise.
* lib/openat.c (AT_FUNC_USE_F1_COND) [fstatat, unlinkat]:
Likewise.
* lib/mkdirat.c (AT_FUNC_F2, AT_FUNC_USE_F1_COND): Delete.
* lib/selinux-at.c (AT_FUNC_F2, AT_FUNC_USE_F1_COND)
[getfileconat, lgetfileconat, setfileconat, lsetfileconat]:
Likewise.

Signed-off-by: Eric Blake <ebb9@byu.net>

diff --git a/ChangeLog b/ChangeLog
index a73cad1..288440e 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,19 @@
 2009-09-03  Eric Blake  <ebb9@byu.net>
 
+       openat: make template easier to use
+       * lib/at-func.c (CALL_FUNC): Allow AT_FUNC_USE_F1_COND and
+       AT_FUNC_F2 to be undefined.
+       (VALIDATE_FLAG): New macro; use it to reject bad flags.
+       (AT_FUNC_USE_F1_COND): Change sense to just flag bit.
+       * lib/fchmodat.c (AT_FUNC_USE_F1_COND): Adjust.
+       * lib/fchownat.c (AT_FUNC_USE_F1_COND): Likewise.
+       * lib/openat.c (AT_FUNC_USE_F1_COND) [fstatat, unlinkat]:
+       Likewise.
+       * lib/mkdirat.c (AT_FUNC_F2, AT_FUNC_USE_F1_COND): Delete.
+       * lib/selinux-at.c (AT_FUNC_F2, AT_FUNC_USE_F1_COND)
+       [getfileconat, lgetfileconat, setfileconat, lsetfileconat]:
+       Likewise.
+
        openat: declare in POSIX headers
        * NEWS: Mention this.
        * modules/openat (configure.ac): Declare witnesses.

diff --git a/lib/at-func.c b/lib/at-func.c
index c7963fe..620fdaf 100644 (file)
--- a/lib/at-func.c
+++ b/lib/at-func.c
@@ -1,5 +1,5 @@
 /* Define an at-style functions like fstatat, unlinkat, fchownat, etc.
-   Copyright (C) 2006 Free Software Foundation, Inc.
+   Copyright (C) 2006, 2009 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -16,14 +16,27 @@
 
 /* written by Jim Meyering */
 
-#define CALL_FUNC(F)                           \
-  (AT_FUNC_USE_F1_COND                         \
+#ifdef AT_FUNC_USE_F1_COND
+# define CALL_FUNC(F)                          \
+  (flag == AT_FUNC_USE_F1_COND                 \
     ? AT_FUNC_F1 (F AT_FUNC_POST_FILE_ARGS)    \
     : AT_FUNC_F2 (F AT_FUNC_POST_FILE_ARGS))
+# define VALIDATE_FLAG(F)                      \
+  if (flag & ~AT_FUNC_USE_F1_COND)             \
+    {                                          \
+      errno = EINVAL;                          \
+      return -1;                               \
+    }
+#else
+# define CALL_FUNC(F) (AT_FUNC_F1 (F AT_FUNC_POST_FILE_ARGS))
+# define VALIDATE_FLAG(F) /* empty */
+#endif
 
-/* Call AT_FUNC_F1 or AT_FUNC_F2 (testing AT_FUNC_USE_F1_COND to
-   determine which) to operate on FILE, which is in the directory
-   open on descriptor FD.  If possible, do it without changing the
+/* Call AT_FUNC_F1 to operate on FILE, which is in the directory
+   open on descriptor FD.  If AT_FUNC_USE_F1_COND is defined to a value,
+   AT_FUNC_POST_FILE_PARAM_DECLS must inlude a parameter named flag;
+   call AT_FUNC_F2 if FLAG is 0 or fail if FLAG contains more bits than
+   AT_FUNC_USE_F1_COND.  If possible, do it without changing the
    working directory.  Otherwise, resort to using save_cwd/fchdir,
    then AT_FUNC_F?/restore_cwd.  If either the save_cwd or the restore_cwd
    fails, then give a diagnostic and exit nonzero.  */
@@ -34,6 +47,8 @@ AT_FUNC_NAME (int fd, char const *file AT_FUNC_POST_FILE_PARAM_DECLS)
   int saved_errno;
   int err;
 
+  VALIDATE_FLAG (flag);
+
   if (fd == AT_FDCWD || IS_ABSOLUTE_FILE_NAME (file))
     return CALL_FUNC (file);
 

diff --git a/lib/fchmodat.c b/lib/fchmodat.c
index 23eee64..cc2776e 100644 (file)
--- a/lib/fchmodat.c
+++ b/lib/fchmodat.c
@@ -45,7 +45,7 @@ static int lchmod (char const *f, mode_t m) { errno = ENOSYS; return -1; }
 #define AT_FUNC_NAME fchmodat
 #define AT_FUNC_F1 lchmod
 #define AT_FUNC_F2 chmod
-#define AT_FUNC_USE_F1_COND flag == AT_SYMLINK_NOFOLLOW
+#define AT_FUNC_USE_F1_COND AT_SYMLINK_NOFOLLOW
 #define AT_FUNC_POST_FILE_PARAM_DECLS , mode_t mode, int flag
 #define AT_FUNC_POST_FILE_ARGS        , mode
 #include "at-func.c"

diff --git a/lib/fchownat.c b/lib/fchownat.c
index c217b52..ba5d86b 100644 (file)
--- a/lib/fchownat.c
+++ b/lib/fchownat.c
@@ -41,7 +41,7 @@
 #define AT_FUNC_NAME fchownat
 #define AT_FUNC_F1 lchown
 #define AT_FUNC_F2 chown
-#define AT_FUNC_USE_F1_COND flag == AT_SYMLINK_NOFOLLOW
+#define AT_FUNC_USE_F1_COND AT_SYMLINK_NOFOLLOW
 #define AT_FUNC_POST_FILE_PARAM_DECLS , uid_t owner, gid_t group, int flag
 #define AT_FUNC_POST_FILE_ARGS        , owner, group
 #include "at-func.c"

diff --git a/lib/mkdirat.c b/lib/mkdirat.c
index d4b3317..33ece9c 100644 (file)
--- a/lib/mkdirat.c
+++ b/lib/mkdirat.c
@@ -34,8 +34,6 @@
 
 #define AT_FUNC_NAME mkdirat
 #define AT_FUNC_F1 mkdir
-#define AT_FUNC_F2 mkdir
-#define AT_FUNC_USE_F1_COND 1
 #define AT_FUNC_POST_FILE_PARAM_DECLS , mode_t mode
 #define AT_FUNC_POST_FILE_ARGS        , mode
 #include "at-func.c"

diff --git a/lib/openat.c b/lib/openat.c
index 0e2c27b..e1471b8 100644 (file)
--- a/lib/openat.c
+++ b/lib/openat.c
@@ -169,7 +169,7 @@ openat_needs_fchdir (void)
 #define AT_FUNC_NAME fstatat
 #define AT_FUNC_F1 lstat
 #define AT_FUNC_F2 stat
-#define AT_FUNC_USE_F1_COND flag == AT_SYMLINK_NOFOLLOW
+#define AT_FUNC_USE_F1_COND AT_SYMLINK_NOFOLLOW
 #define AT_FUNC_POST_FILE_PARAM_DECLS , struct stat *st, int flag
 #define AT_FUNC_POST_FILE_ARGS        , st
 #include "at-func.c"
@@ -191,7 +191,7 @@ openat_needs_fchdir (void)
 #define AT_FUNC_NAME unlinkat
 #define AT_FUNC_F1 rmdir
 #define AT_FUNC_F2 unlink
-#define AT_FUNC_USE_F1_COND flag == AT_REMOVEDIR
+#define AT_FUNC_USE_F1_COND AT_REMOVEDIR
 #define AT_FUNC_POST_FILE_PARAM_DECLS , int flag
 #define AT_FUNC_POST_FILE_ARGS        /* empty */
 #include "at-func.c"

diff --git a/lib/selinux-at.c b/lib/selinux-at.c
index 18e6b0f..65f938b 100644 (file)
--- a/lib/selinux-at.c
+++ b/lib/selinux-at.c
@@ -33,56 +33,40 @@
 
 #define AT_FUNC_NAME getfileconat
 #define AT_FUNC_F1 getfilecon
-#define AT_FUNC_F2 getfilecon
-#define AT_FUNC_USE_F1_COND 1
 #define AT_FUNC_POST_FILE_PARAM_DECLS , security_context_t *con
 #define AT_FUNC_POST_FILE_ARGS        , con
 #include "at-func.c"
 #undef AT_FUNC_NAME
 #undef AT_FUNC_F1
-#undef AT_FUNC_F2
-#undef AT_FUNC_USE_F1_COND
 #undef AT_FUNC_POST_FILE_PARAM_DECLS
 #undef AT_FUNC_POST_FILE_ARGS
 
 #define AT_FUNC_NAME lgetfileconat
 #define AT_FUNC_F1 lgetfilecon
-#define AT_FUNC_F2 lgetfilecon
-#define AT_FUNC_USE_F1_COND 1
 #define AT_FUNC_POST_FILE_PARAM_DECLS , security_context_t *con
 #define AT_FUNC_POST_FILE_ARGS        , con
 #include "at-func.c"
 #undef AT_FUNC_NAME
 #undef AT_FUNC_F1
-#undef AT_FUNC_F2
-#undef AT_FUNC_USE_F1_COND
 #undef AT_FUNC_POST_FILE_PARAM_DECLS
 #undef AT_FUNC_POST_FILE_ARGS
 
 #define AT_FUNC_NAME setfileconat
 #define AT_FUNC_F1 setfilecon
-#define AT_FUNC_F2 setfilecon
-#define AT_FUNC_USE_F1_COND 1
 #define AT_FUNC_POST_FILE_PARAM_DECLS , security_context_t con
 #define AT_FUNC_POST_FILE_ARGS        , con
 #include "at-func.c"
 #undef AT_FUNC_NAME
 #undef AT_FUNC_F1
-#undef AT_FUNC_F2
-#undef AT_FUNC_USE_F1_COND
 #undef AT_FUNC_POST_FILE_PARAM_DECLS
 #undef AT_FUNC_POST_FILE_ARGS
 
 #define AT_FUNC_NAME lsetfileconat
 #define AT_FUNC_F1 lsetfilecon
-#define AT_FUNC_F2 lsetfilecon
-#define AT_FUNC_USE_F1_COND 1
 #define AT_FUNC_POST_FILE_PARAM_DECLS , security_context_t con
 #define AT_FUNC_POST_FILE_ARGS        , con
 #include "at-func.c"
 #undef AT_FUNC_NAME
 #undef AT_FUNC_F1
-#undef AT_FUNC_F2
-#undef AT_FUNC_USE_F1_COND
 #undef AT_FUNC_POST_FILE_PARAM_DECLS
 #undef AT_FUNC_POST_FILE_ARGS