Patch for WORM, git master

Michail Srgznsk rasmikun at gmail.com
Fri Oct 10 08:08:49 MDT 2014


Hello,

I posted patch to bug 10430 and want to get technical help about my
solution. (https://bugzilla.samba.org/show_bug.cgi?id=10430#c4)

The main idea is to wrap all 'problem' functions: ntimes, open, chmod. What
do you think about this?

I tested this for samba-3.5.6, and it works fine, but Im not sure that it
is good idea, may be there are pitfalls in this solution. I must warn, that
THIS diff not fully tested, I only port my diff for 3.5.6. back to 'git
master'.

-- 
Regards,
Mikhail Skorzhinskiy
mail to: rasmikun at gmail.com
-------------- next part --------------
diff --git a/source3/modules/vfs_worm.c b/source3/modules/vfs_worm.c
index 3097419..eff81ce 100644
--- a/source3/modules/vfs_worm.c
+++ b/source3/modules/vfs_worm.c
@@ -22,77 +22,173 @@
 #include "system/filesys.h"
 #include "libcli/security/security.h"
 
+const uint32_t write_access_flags =
+    FILE_WRITE_DATA | FILE_APPEND_DATA |
+    FILE_WRITE_ATTRIBUTES | DELETE_ACCESS |
+    WRITE_DAC_ACCESS | WRITE_OWNER_ACCESS;
+
+/*
+ * Helpers
+ */
+
+static bool is_readonly(vfs_handle_struct *handle, const struct smb_filename *smb_fname)
+{
+    bool readonly = false;
+
+    if (VALID_STAT(smb_fname->st)) {
+        double age;
+        age = timespec_elapsed(&smb_fname->st.st_ex_ctime);
+        int grace_period = lp_parm_int(SNUM(handle->conn), "conn",
+                "grace_period", 3600);
+        if (age > grace_period) {
+            readonly = true;
+        }
+    }
+
+    return readonly;
+}
+
+static NTSTATUS filename_to_smb_filename_convert(connection_struct *conn,
+        const char *filename,
+        struct smb_filename **smb_fname)
+{
+    NTSTATUS status;
+    TALLOC_CTX *ctx = talloc_tos();
+    char *name = talloc_strdup(ctx, filename);
+
+    if (!name) {
+        return NT_STATUS_NO_MEMORY;
+    }
+    unix_format(name);
+    name = unix_clean_name(ctx, name);
+    if (!name) {
+        return NT_STATUS_NO_MEMORY;
+    }
+    trim_string(name, "/", "/");
+
+    status = unix_convert(ctx, conn, name, smb_fname, 0);
+    if (!NT_STATUS_IS_OK(status)) {
+        return NT_STATUS_NO_MEMORY;
+    }
+
+    return NT_STATUS_OK;
+}
+
+/*
+ * Wrappers
+ */
+
 static NTSTATUS vfs_worm_create_file(vfs_handle_struct *handle,
-				     struct smb_request *req,
-				     uint16_t root_dir_fid,
-				     struct smb_filename *smb_fname,
-				     uint32_t access_mask,
-				     uint32_t share_access,
-				     uint32_t create_disposition,
-				     uint32_t create_options,
-				     uint32_t file_attributes,
-				     uint32_t oplock_request,
-				     struct smb2_lease *lease,
-				     uint64_t allocation_size,
-				     uint32_t private_flags,
-				     struct security_descriptor *sd,
-				     struct ea_list *ea_list,
-				     files_struct **result,
-				     int *pinfo)
+                                     struct smb_request *req,
+                                     uint16_t root_dir_fid,
+                                     struct smb_filename *smb_fname,
+                                     uint32_t access_mask,
+                                     uint32_t share_access,
+                                     uint32_t create_disposition,
+                                     uint32_t create_options,
+                                     uint32_t file_attributes,
+                                     uint32_t oplock_request,
+                                     struct smb2_lease *lease,
+                                     uint64_t allocation_size,
+                                     uint32_t private_flags,
+                                     struct security_descriptor *sd,
+                                     struct ea_list *ea_list,
+                                     files_struct **result,
+                                     int *pinfo)
 {
-	bool readonly = false;
-	const uint32_t write_access_flags =
-		FILE_WRITE_DATA | FILE_APPEND_DATA |
-		FILE_WRITE_ATTRIBUTES | DELETE_ACCESS |
-		WRITE_DAC_ACCESS | WRITE_OWNER_ACCESS;
-	NTSTATUS status;
-
-	if (VALID_STAT(smb_fname->st)) {
-		double age;
-		age = timespec_elapsed(&smb_fname->st.st_ex_ctime);
-		if (age > lp_parm_int(SNUM(handle->conn), "worm",
-				      "grace_period", 3600)) {
-			readonly = true;
-		}
-	}
-
-	if (readonly && (access_mask & write_access_flags)) {
-		return NT_STATUS_ACCESS_DENIED;
-	}
-
-	status = SMB_VFS_NEXT_CREATE_FILE(
-		handle, req, root_dir_fid, smb_fname, access_mask,
-		share_access, create_disposition, create_options,
-		file_attributes, oplock_request, lease, allocation_size,
-		private_flags, sd, ea_list, result, pinfo);
-	if (!NT_STATUS_IS_OK(status)) {
-		return status;
-	}
-
-	/*
-	 * Access via MAXIMUM_ALLOWED_ACCESS?
-	 */
-	if (readonly && ((*result)->access_mask & write_access_flags)) {
-		close_file(req, *result, NORMAL_CLOSE);
-		return NT_STATUS_ACCESS_DENIED;
-	}
-	return NT_STATUS_OK;
+    bool readonly = false;
+
+    if (readonly && (access_mask & write_access_flags)) {
+        return NT_STATUS_ACCESS_DENIED;
+    }
+
+    NTSTATUS status = SMB_VFS_NEXT_CREATE_FILE(
+            handle, req, root_dir_fid, smb_fname, access_mask,
+            share_access, create_disposition, create_options,
+            file_attributes, oplock_request, lease, allocation_size,
+            private_flags, sd, ea_list, result, pinfo);
+    if (!NT_STATUS_IS_OK(status)) {
+        return status;
+    }
+
+    /*
+     * Access via MAXIMUM_ALLOWED_ACCESS?
+     */
+    if (readonly && ((*result)->access_mask & write_access_flags)) {
+        close_file(req, *result, NORMAL_CLOSE);
+        return NT_STATUS_ACCESS_DENIED;
+    }
+    return NT_STATUS_OK;
 }
 
+static int vfs_worm_open(vfs_handle_struct *handle,
+        struct smb_filename *smb_fname,
+        files_struct *fsp, int flags, mode_t mode)
+{
+    bool readonly = is_readonly(handle, smb_fname);
+
+    if (readonly && (fsp->access_mask & write_access_flags)) {
+        errno = EACCES;
+        return -1;
+    }
+
+    return SMB_VFS_NEXT_OPEN(handle, smb_fname, fsp, flags, mode);
+}
+
+static int vfs_worm_ntimes(vfs_handle_struct *handle,
+        const struct smb_filename *smb_fname,
+        struct smb_file_time *ft)
+{
+    bool readonly = is_readonly(handle, smb_fname);
+
+    if (readonly) {
+        errno = EACCES;
+        return -1;
+    }
+
+    return SMB_VFS_NEXT_NTIMES(handle, smb_fname, ft);
+}
+
+static int vfs_worm_chmod(vfs_handle_struct *handle, const char *file_name, mode_t mode)
+{
+    struct smb_filename *smb_fname;
+    bool readonly = 1;
+
+    NTSTATUS status = filename_to_smb_filename_convert(handle->conn, file_name, &smb_fname);
+
+    if (NT_STATUS_IS_OK(status)) {
+        readonly = is_readonly(handle, smb_fname);
+    }
+
+    if (readonly) {
+        errno = EACCES;
+        return -1;
+    }
+
+    return SMB_VFS_NEXT_CHMOD(handle, file_name, mode);
+}
+
+/*
+ * Init && pointers table
+ */
+
 static struct vfs_fn_pointers vfs_worm_fns = {
-	.create_file_fn = vfs_worm_create_file,
+    .create_file_fn = vfs_worm_create_file,
+    .open_fn        = vfs_worm_open,
+    .ntimes_fn      = vfs_worm_ntimes,
+    .chmod_fn       = vfs_worm_chmod
 };
 
 NTSTATUS vfs_worm_init(void);
 NTSTATUS vfs_worm_init(void)
 {
-	NTSTATUS ret;
+    NTSTATUS ret;
 
-	ret = smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "worm",
-			       &vfs_worm_fns);
-	if (!NT_STATUS_IS_OK(ret)) {
-		return ret;
-	}
+    ret = smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "worm",
+            &vfs_worm_fns);
+    if (!NT_STATUS_IS_OK(ret)) {
+        return ret;
+    }
 
-	return ret;
+    return ret;
 }


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