Rename configure.in -> configure.ac. Based on PR #976.

[mono.git] / mono / io-layer / io.c

diff --git a/mono/io-layer/io.c b/mono/io-layer/io.c
index ab483c6685ecf3c80c5b5f0b290ae167ede994d3..9e2fb959697245a7cab2e78ef642f118e752bc8e 100755 (executable)
--- a/mono/io-layer/io.c
+++ b/mono/io-layer/io.c
@@ -240,6 +240,43 @@ static void io_ops_init (void)
 /* Some utility functions.
  */
 
+/*
+ * Check if a file is writable by the current user.
+ *
+ * This is is a best effort kind of thing. It assumes a reasonable sane set
+ * of permissions by the underlying OS.
+ *
+ * We assume that basic unix permission bits are authoritative. Which might not
+ * be the case under systems with extended permissions systems (posix ACLs, SELinux, OSX/iOS sandboxing, etc)
+ *
+ * The choice of access as the fallback is due to the expected lower overhead compared to trying to open the file.
+ *
+ * The only expected problem with using access are for root, setuid or setgid programs as access is not consistent
+ * under those situations. It's to be expected that this should not happen in practice as those bits are very dangerous
+ * and should not be used with a dynamic runtime.
+ */
+static gboolean
+is_file_writable (struct stat *st, const char *path)
+{
+       /* Is it globally writable? */
+       if (st->st_mode & S_IWOTH)
+               return 1;
+
+       /* Am I the owner? */
+       if ((st->st_uid == geteuid ()) && (st->st_mode & S_IWUSR))
+               return 1;
+
+       /* Am I in the same group? */
+       if ((st->st_gid == getegid ()) && (st->st_mode & S_IWGRP))
+               return 1;
+
+       /* Fallback to using access(2). It's not ideal as it might not take into consideration euid/egid
+        * but it's the only sane option we have on unix.
+        */
+       return access (path, W_OK) == 0;
+}
+
+
 static guint32 _wapi_stat_to_file_attributes (const gchar *pathname,
                                              struct stat *buf,
                                              struct stat *lbuf)
@@ -259,14 +296,14 @@ static guint32 _wapi_stat_to_file_attributes (const gchar *pathname,
 
        if (S_ISDIR (buf->st_mode)) {
                attrs = FILE_ATTRIBUTE_DIRECTORY;
-               if (!(buf->st_mode & S_IWUSR)) {
+               if (!is_file_writable (buf, pathname)) {
                        attrs |= FILE_ATTRIBUTE_READONLY;
                }
                if (filename[0] == '.') {
                        attrs |= FILE_ATTRIBUTE_HIDDEN;
                }
        } else {
-               if (!(buf->st_mode & S_IWUSR)) {
+               if (!is_file_writable (buf, pathname)) {
                        attrs = FILE_ATTRIBUTE_READONLY;
 
                        if (filename[0] == '.') {
@@ -668,7 +705,7 @@ static gboolean file_setendoffile(gpointer handle)
        }
        
 #ifdef FTRUNCATE_DOESNT_EXTEND
-       /* I haven't bothered to write the configure.in stuff for this
+       /* I haven't bothered to write the configure.ac stuff for this
         * because I don't know if any platform needs it.  I'm leaving
         * this code just in case though
         */
@@ -2045,7 +2082,7 @@ ReplaceFile (const gunichar2 *replacedFileName, const gunichar2 *replacementFile
                      const gunichar2 *backupFileName, guint32 replaceFlags, 
                      gpointer exclude, gpointer reserved)
 {
-       int result, errno_copy, backup_fd = -1,replaced_fd = -1;
+       int result, backup_fd = -1,replaced_fd = -1;
        gchar *utf8_replacedFileName, *utf8_replacementFileName = NULL, *utf8_backupFileName = NULL;
        struct stat stBackup;
        gboolean ret = FALSE;
@@ -2063,13 +2100,11 @@ ReplaceFile (const gunichar2 *replacedFileName, const gunichar2 *replacementFile
                // Open the backup file for read so we can restore the file if an error occurs.
                backup_fd = _wapi_open (utf8_backupFileName, O_RDONLY, 0);
                result = _wapi_rename (utf8_replacedFileName, utf8_backupFileName);
-               errno_copy = errno;
                if (result == -1)
                        goto replace_cleanup;
        }
 
        result = _wapi_rename (utf8_replacementFileName, utf8_replacedFileName);
-       errno_copy = errno;
        if (result == -1) {
                _wapi_set_last_path_error_from_errno (NULL, utf8_replacementFileName);
                _wapi_rename (utf8_backupFileName, utf8_replacedFileName);
@@ -2144,8 +2179,6 @@ gpointer GetStdHandle(WapiStdHandle stdhandle)
 
        handle = GINT_TO_POINTER (fd);
 
-       pthread_cleanup_push ((void(*)(void *))mono_mutex_unlock_in_cleanup,
-                             (void *)&stdhandle_mutex);
        thr_ret = mono_mutex_lock (&stdhandle_mutex);
        g_assert (thr_ret == 0);
 
@@ -2167,7 +2200,6 @@ gpointer GetStdHandle(WapiStdHandle stdhandle)
   done:
        thr_ret = mono_mutex_unlock (&stdhandle_mutex);
        g_assert (thr_ret == 0);
-       pthread_cleanup_pop (0);
        
        return(handle);
 }
@@ -2760,8 +2792,6 @@ gboolean FindNextFile (gpointer handle, WapiFindData *find_data)
                return(FALSE);
        }
 
-       pthread_cleanup_push ((void(*)(void *))_wapi_handle_unlock_handle,
-                             handle);
        thr_ret = _wapi_handle_lock_handle (handle);
        g_assert (thr_ret == 0);
        
@@ -2871,7 +2901,6 @@ retry:
 cleanup:
        thr_ret = _wapi_handle_unlock_handle (handle);
        g_assert (thr_ret == 0);
-       pthread_cleanup_pop (0);
        
        return(ret);
 }
@@ -2904,8 +2933,6 @@ gboolean FindClose (gpointer handle)
                return(FALSE);
        }
 
-       pthread_cleanup_push ((void(*)(void *))_wapi_handle_unlock_handle,
-                             handle);
        thr_ret = _wapi_handle_lock_handle (handle);
        g_assert (thr_ret == 0);
        
@@ -2914,7 +2941,6 @@ gboolean FindClose (gpointer handle)
 
        thr_ret = _wapi_handle_unlock_handle (handle);
        g_assert (thr_ret == 0);
-       pthread_cleanup_pop (0);
        
        _wapi_handle_unref (handle);
        
@@ -3757,7 +3783,9 @@ add_drive_string (guint32 len, gunichar2 *buf, LinuxMountInfoParseState *state)
                        ignore_entry = TRUE;
                else
                        ignore_entry = FALSE;
-       } else
+       } else if (state->fstype_index == 3 && memcmp ("nfs", state->fstype, state->fstype_index) == 0)
+               ignore_entry = FALSE;
+       else
                ignore_entry = TRUE;
 
        if (!ignore_entry) {