X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/mLib/blobdiff_plain/dd3c57bc8cac59e0d657ee665ce462988d27d714..18c831dcd0ae4d660c70ccac69d27ed2a97851be:/sys/fdpass.h

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+/* -*-c-*-
+ *
+ * File descriptor passing
+ *
+ * (c) 2003 Straylight/Edgeware
+ */
+
+/*----- Licensing notice --------------------------------------------------*
+ *
+ * This file is part of the mLib utilities library.
+ *
+ * mLib is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Library General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * mLib is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with mLib; if not, write to the Free
+ * Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ */
+
+#ifndef MLIB_FDPASS_H
+#define MLIB_FDPASS_H
+
+#ifdef __cplusplus
+  extern "C" {
+#endif
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <sys/types.h>
+#include <unistd.h>
+
+/*----- Functions provided ------------------------------------------------*/
+
+/* --- @fdpass_send@ --- *
+ *
+ * Arguments:	@int sock@ = socket to send over
+ *		@int fd@ = file descriptor to send
+ *		@const void *p@ = pointer to data to send
+ *		@size_t sz@ = size of buffer to send
+ *
+ * Returns:	On error, @-1@, otherwise number of bytes transferred from
+ *		@p@.
+ *
+ * Use:		Sends a copy of file descriptor @fd@ to the other end of
+ *		@sock@.
+ */
+
+extern ssize_t fdpass_send(int /*sock*/, int /*fd*/,
+			   const void */*p*/, size_t /*sz*/);
+
+/* --- @fdpass_recv@ --- *
+ *
+ * Arguments:	@int sock@ = socket to send over
+ *		@int *fd@ = where to put received descriptor
+ *		@void *p@ = pointer to where to put data
+ *		@size_t sz@ = size of buffer
+ *
+ * Returns:	On error, @-1@, otherwise number of bytes transferred.
+ *
+ * Use:		Receives a file descriptor.  If the call succeeds, and there
+ *		was a file descriptor, then @fd@ won't be @-1@ on exit;
+ *		otherwise it will.  At most one descriptor will be collected.
+ */
+
+extern ssize_t fdpass_recv(int /*sock*/, int */*fd*/,
+			   void */*p*/, size_t /*sz*/);
+
+/*----- That's all, folks -------------------------------------------------*/
+
+#ifdef __cplusplus
+  }
+#endif
+
+#endif