[Emacs-diffs] trunk r115818: Fall back on SetNamedSecurityInfo if SetFileSecurity fails in acl_set_file.

[Eli Zaretskii]

------------------------------------------------------------
revno: 115818
revision-id: address@hidden
parent: address@hidden
author: Fabrice Popineau <address@hidden>
committer: Eli Zaretskii <address@hidden>
branch nick: trunk
timestamp: Tue 2013-12-31 17:00:43 +0200
message:
  Fall back on SetNamedSecurityInfo if SetFileSecurity fails in acl_set_file.
  
   src/w32.c (set_named_security_info): New function.
   (acl_set_file): Fall back on set_named_security_info if
   set_file_security fails.  Fixes rare failures in backups.
   (g_b_init_set_named_security_info_w)
   (g_b_init_set_named_security_info_a): New static variables.
   (globals_of_w32): Initialize them to zero.
   (set_named_security_info): Set them to non-zero if the
   corresponding API is available.
   (SetNamedSecurityInfoW_Proc, SetNamedSecurityInfoA_Proc): New
   function typedefs.
modified:
  src/ChangeLog                  changelog-20091113204419-o5vbwnq5f7feedwu-1438
  src/w32.c                      w32.c-20091113204419-o5vbwnq5f7feedwu-808

=== modified file 'src/ChangeLog'
--- a/src/ChangeLog     2013-12-31 09:48:54 +0000
+++ b/src/ChangeLog     2013-12-31 15:00:43 +0000
@@ -1,3 +1,16 @@
+2013-12-31  Fabrice Popineau  <address@hidden>
+
+       * w32.c (set_named_security_info): New function.
+       (acl_set_file): Fall back on set_named_security_info if
+       set_file_security fails.
+       (g_b_init_set_named_security_info_w)
+       (g_b_init_set_named_security_info_a): New static variables.
+       (globals_of_w32): Initialize them to zero.
+       (set_named_security_info): Set them to non-zero if the
+       corresponding API is available.
+       (SetNamedSecurityInfoW_Proc, SetNamedSecurityInfoA_Proc): New
+       function typedefs.
+
 2013-12-31  Martin Rudalics  <address@hidden>
 
        Some more fixes following pixelwise resize changes including one

=== modified file 'src/w32.c'
--- a/src/w32.c 2013-12-30 17:51:28 +0000
+++ b/src/w32.c 2013-12-31 15:00:43 +0000
@@ -303,6 +303,8 @@
 static BOOL g_b_init_is_valid_security_descriptor;
 static BOOL g_b_init_set_file_security_w;
 static BOOL g_b_init_set_file_security_a;
+static BOOL g_b_init_set_named_security_info_w;
+static BOOL g_b_init_set_named_security_info_a;
 static BOOL g_b_init_get_adapters_info;
 
 /*
@@ -377,6 +379,22 @@
     LPCSTR lpFileName,
     SECURITY_INFORMATION SecurityInformation,
     PSECURITY_DESCRIPTOR pSecurityDescriptor);
+typedef DWORD (WINAPI *SetNamedSecurityInfoW_Proc) (
+    LPCWSTR lpObjectName,
+    SE_OBJECT_TYPE ObjectType,
+    SECURITY_INFORMATION SecurityInformation,
+    PSID psidOwner,
+    PSID psidGroup,
+    PACL pDacl,
+    PACL pSacl);
+typedef DWORD (WINAPI *SetNamedSecurityInfoA_Proc) (
+    LPCSTR lpObjectName,
+    SE_OBJECT_TYPE ObjectType,
+    SECURITY_INFORMATION SecurityInformation,
+    PSID psidOwner,
+    PSID psidGroup,
+    PACL pDacl,
+    PACL pSacl);
 typedef BOOL (WINAPI * GetSecurityDescriptorOwner_Proc) (
     PSECURITY_DESCRIPTOR pSecurityDescriptor,
     PSID *pOwner,
@@ -811,6 +829,69 @@
     }
 }
 
+static DWORD WINAPI
+set_named_security_info (LPCTSTR lpObjectName,
+                        SE_OBJECT_TYPE ObjectType,
+                        SECURITY_INFORMATION SecurityInformation,
+                        PSID psidOwner,
+                        PSID psidGroup,
+                        PACL pDacl,
+                        PACL pSacl)
+{
+  static SetNamedSecurityInfoW_Proc s_pfn_Set_Named_Security_InfoW = NULL;
+  static SetNamedSecurityInfoA_Proc s_pfn_Set_Named_Security_InfoA = NULL;
+  HMODULE hm_advapi32 = NULL;
+  if (is_windows_9x () == TRUE)
+    {
+      errno = ENOTSUP;
+      return ENOTSUP;
+    }
+  if (w32_unicode_filenames)
+    {
+      wchar_t filename_w[MAX_PATH];
+
+      if (g_b_init_set_named_security_info_w == 0)
+       {
+         g_b_init_set_named_security_info_w = 1;
+         hm_advapi32 = LoadLibrary ("Advapi32.dll");
+         s_pfn_Set_Named_Security_InfoW =
+           (SetNamedSecurityInfoW_Proc) GetProcAddress (hm_advapi32,
+                                                        
"SetNamedSecurityInfoW");
+       }
+      if (s_pfn_Set_Named_Security_InfoW == NULL)
+       {
+         errno = ENOTSUP;
+         return ENOTSUP;
+       }
+      filename_to_utf16 (lpObjectName, filename_w);
+      return (s_pfn_Set_Named_Security_InfoW (filename_w, ObjectType,
+                                             SecurityInformation, psidOwner,
+                                             psidGroup, pDacl, pSacl));
+    }
+  else
+    {
+      char filename_a[MAX_PATH];
+
+      if (g_b_init_set_named_security_info_a == 0)
+       {
+         g_b_init_set_named_security_info_a = 1;
+         hm_advapi32 = LoadLibrary ("Advapi32.dll");
+         s_pfn_Set_Named_Security_InfoA =
+           (SetNamedSecurityInfoA_Proc) GetProcAddress (hm_advapi32, 
+                                                        
"SetNamedSecurityInfoA");
+       }
+      if (s_pfn_Set_Named_Security_InfoA == NULL)
+       {
+         errno = ENOTSUP;
+         return ENOTSUP;
+       }
+      filename_to_ansi (lpObjectName, filename_a);
+      return (s_pfn_Set_Named_Security_InfoA (filename_a, ObjectType,
+                                             SecurityInformation, psidOwner,
+                                             psidGroup, pDacl, pSacl));
+    }
+}
+
 static BOOL WINAPI
 get_security_descriptor_owner (PSECURITY_DESCRIPTOR pSecurityDescriptor,
                               PSID *pOwner,
@@ -5903,7 +5984,7 @@
   DWORD err;
   int st = 0, retval = -1;
   SECURITY_INFORMATION flags = 0;
-  PSID psid;
+  PSID psidOwner, psidGroup;
   PACL pacl;
   BOOL dflt;
   BOOL dacl_present;
@@ -5929,11 +6010,13 @@
   else
     fname = filename;
 
-  if (get_security_descriptor_owner ((PSECURITY_DESCRIPTOR)acl, &psid, &dflt)
-      && psid)
+  if (get_security_descriptor_owner ((PSECURITY_DESCRIPTOR)acl, &psidOwner,
+                                    &dflt)
+      && psidOwner)
     flags |= OWNER_SECURITY_INFORMATION;
-  if (get_security_descriptor_group ((PSECURITY_DESCRIPTOR)acl, &psid, &dflt)
-      && psid)
+  if (get_security_descriptor_group ((PSECURITY_DESCRIPTOR)acl, &psidGroup,
+                                    &dflt)
+      && psidGroup)
     flags |= GROUP_SECURITY_INFORMATION;
   if (get_security_descriptor_dacl ((PSECURITY_DESCRIPTOR)acl, &dacl_present,
                                    &pacl, &dflt)
@@ -5960,10 +6043,22 @@
 
   e = errno;
   errno = 0;
+  /* SetFileSecurity is deprecated by MS, and sometimes fails when
+     DACL inheritance is involved, but it seems to preserve ownership
+     better than SetNamedSecurity, which is important e.g., in
+     copy-file.  */
   if (!set_file_security (fname, flags, (PSECURITY_DESCRIPTOR)acl))
     {
       err = GetLastError ();
 
+      if (errno != ENOTSUP)
+       err = set_named_security_info (fname, SE_FILE_OBJECT, flags,
+                                      psidOwner, psidGroup, pacl, NULL);
+    }
+  else
+    err = ERROR_SUCCESS;
+  if (err != ERROR_SUCCESS)
+    {
       if (errno == ENOTSUP)
        ;
       else if (err == ERROR_INVALID_OWNER
@@ -8878,6 +8973,8 @@
   g_b_init_is_valid_security_descriptor = 0;
   g_b_init_set_file_security_w = 0;
   g_b_init_set_file_security_a = 0;
+  g_b_init_set_named_security_info_w = 0;
+  g_b_init_set_named_security_info_a = 0;
   g_b_init_get_adapters_info = 0;
   num_of_processors = 0;
   /* The following sets a handler for shutdown notifications for