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, size_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 FdMover::Element::Element(int level, int type)
  50 {
  51         cmsg_level = level;
  52         cmsg_type = type;
  53 }
  54
  55
  56 FdMover::Message::Message(const void *data, size_t length)
  57         : iovec(data, length)
  58 {
  59         msg_name = NULL;
  60         msg_namelen = 0;
  61         msg_iov = &iovec;
  62         msg_iovlen = 1;
  63         msg_control = NULL;
  64         msg_controllen = 0;
  65         msg_flags = 0;
  66 }
  67
  68 void FdMover::Message::set(Element *elem)
  69 {
  70         msg_control = (caddr_t)elem;
  71         msg_controllen = elem->cmsg_len;
  72 }
  73
  74
  75 size_t FdMover::send(const void *data, size_t length, const FdVector &fds)
  76 {
  77         auto_ptr<Element> elem(new (fds.size() * sizeof(int)) Element (SOL_SOCKET, SCM_RIGHTS));
  78         copy(fds.begin(), fds.end(), &elem.get()->payload<int>());
  79         Message msg(data, length);
  80         msg.set(elem.get());
  81         ssize_t rc = ::sendmsg(fd(), &msg, 0);
  82         checkError(rc);
  83         return rc;
  84 }
  85
  86
  87 size_t FdMover::receive(void *data, size_t length, FdVector &fds)
  88 {
  89         static const int maxFds = 20;   // arbitrary limit
  90         Message msg(data, length);
  91         auto_ptr<Element> elem(new (maxFds * sizeof(int)) Element);
  92         msg.set(elem.get());
  93         ssize_t rc = ::recvmsg(fd(), &msg, 0);
  94         checkError(rc);
  95         size_t count = elem.get()->payloadSize() / sizeof(int);
  96         FdVector result;
  97         copy(&elem.get()->payload<int>(), &elem.get()->payload<int>() + count, back_inserter(result));
  98         swap(fds, result);
  99         return rc;
 100 }
 101
 102
 103 }       // end namespace IPPlusPlus
 104 }       // end namespace Security