OSX/libsecurity_utilities/lib/fdmover.cpp

   1 /*
   2  * Copyright (c) 2000-2001,2003-2004,2011-2012,2014 Apple Inc. All Rights Reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23
  24
  25 //
  26 // fdmover - send/receive file descriptors over a UNIX domain socket connection
  27 //
  28 #include "fdmover.h"
  29 #include <iterator>
  30 #include <security_utilities/debugging.h>
  31
  32
  33 namespace Security {
  34 namespace IPPlusPlus {
  35
  36
  37 void *FdMover::Element::operator new (size_t base, ssize_t more)
  38 {
  39         Element *element = (Element *)::malloc(CMSG_SPACE(more));
  40         element->cmsg_len = (socklen_t)CMSG_LEN(more);
  41         return element;
  42 }
  43
  44 void FdMover::Element::operator delete (void *data, size_t base)
  45 {
  46     ::free(data);
  47 }
  48
  49 void FdMover::Element::operator delete (void *data, ssize_t base)
  50 {
  51         ::free(data);
  52 }
  53
  54 FdMover::Element::Element(int level, int type)
  55 {
  56         cmsg_level = level;
  57         cmsg_type = type;
  58 }
  59
  60
  61 FdMover::Message::Message(const void *data, size_t length)
  62         : iovec(data, length)
  63 {
  64         msg_name = NULL;
  65         msg_namelen = 0;
  66         msg_iov = &iovec;
  67         msg_iovlen = 1;
  68         msg_control = NULL;
  69         msg_controllen = 0;
  70         msg_flags = 0;
  71 }
  72
  73 void FdMover::Message::set(Element *elem)
  74 {
  75         msg_control = (caddr_t)elem;
  76         msg_controllen = elem->cmsg_len;
  77 }
  78
  79
  80 size_t FdMover::send(const void *data, size_t length, const FdVector &fds)
  81 {
  82         auto_ptr<Element> elem(new (fds.size() * sizeof(int)) Element (SOL_SOCKET, SCM_RIGHTS));
  83         copy(fds.begin(), fds.end(), &elem.get()->payload<int>());
  84         Message msg(data, length);
  85         msg.set(elem.get());
  86         ssize_t rc = ::sendmsg(fd(), &msg, 0);
  87         checkError(rc);
  88         return rc;
  89 }
  90
  91
  92 size_t FdMover::receive(void *data, size_t length, FdVector &fds)
  93 {
  94         static const int maxFds = 20;   // arbitrary limit
  95         Message msg(data, length);
  96         auto_ptr<Element> elem(new (maxFds * sizeof(int)) Element);
  97         msg.set(elem.get());
  98         ssize_t rc = ::recvmsg(fd(), &msg, 0);
  99         checkError(rc);
 100         size_t count = elem.get()->payloadSize() / sizeof(int);
 101         FdVector result;
 102         copy(&elem.get()->payload<int>(), &elem.get()->payload<int>() + count, back_inserter(result));
 103         swap(fds, result);
 104         return rc;
 105 }
 106
 107
 108 }       // end namespace IPPlusPlus
 109 }       // end namespace Security