1 kumpf 1.1.4.2 /*
  2               //%2006////////////////////////////////////////////////////////////////////////
  3               //
  4               // Copyright (c) 2000, 2001, 2002 BMC Software; Hewlett-Packard Development
  5               // Company, L.P.; IBM Corp.; The Open Group; Tivoli Systems.
  6               // Copyright (c) 2003 BMC Software; Hewlett-Packard Development Company, L.P.;
  7               // IBM Corp.; EMC Corporation, The Open Group.
  8               // Copyright (c) 2004 BMC Software; Hewlett-Packard Development Company, L.P.;
  9               // IBM Corp.; EMC Corporation; VERITAS Software Corporation; The Open Group.
 10               // Copyright (c) 2005 Hewlett-Packard Development Company, L.P.; IBM Corp.;
 11               // EMC Corporation; VERITAS Software Corporation; The Open Group.
 12               // Copyright (c) 2006 Hewlett-Packard Development Company, L.P.; IBM Corp.;
 13               // EMC Corporation; Symantec Corporation; The Open Group.
 14               //
 15               // Permission is hereby granted, free of charge, to any person obtaining a copy
 16               // of this software and associated documentation files (the "Software"), to
 17               // deal in the Software without restriction, including without limitation the
 18               // rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 19               // sell copies of the Software, and to permit persons to whom the Software is
 20               // furnished to do so, subject to the following conditions:
 21               // 
 22 kumpf 1.1.4.2 // THE ABOVE COPYRIGHT NOTICE AND THIS PERMISSION NOTICE SHALL BE INCLUDED IN
 23               // ALL COPIES OR SUBSTANTIAL PORTIONS OF THE SOFTWARE. THE SOFTWARE IS PROVIDED
 24               // "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT
 25               // LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
 26               // PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 27               // HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 28               // ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 29               // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 30               //
 31               //%/////////////////////////////////////////////////////////////////////////////
 32               */
 33               
 34               #ifndef _Executor_Socket_h
 35               #define _Executor_Socket_h
 36               
 37               #include <stdlib.h>
 38               #include <sys/socket.h>
 39               #include <string.h>
 40               #include "Defines.h"
 41               
 42               EXECUTOR_LINKAGE
 43 kumpf 1.1.4.2 int SetNonBlocking(int sock);
 44               
 45               EXECUTOR_LINKAGE
 46               int SetBlocking(int sock);
 47               
 48               EXECUTOR_LINKAGE
 49               ssize_t RecvNonBlock(int sock, void* buffer, size_t size);
 50               
 51               EXECUTOR_LINKAGE
 52               ssize_t SendNonBlock(int sock, const void* buffer, size_t size);
 53               
 54               EXECUTOR_LINKAGE
 55               int CloseOnExec(int fd);
 56               
 57               EXECUTOR_LINKAGE
 58               ssize_t SendDescriptorArray(int sock, int descriptors[], size_t count);
 59               
 60               EXECUTOR_LINKAGE
 61               int CreateSocketPair(int pair[2]);
 62               
 63               static int RecvDescriptorArray(int sock, int descriptors[], size_t count)
 64 kumpf 1.1.4.2 {
 65                   struct iovec iov[1];
 66                   char dummy;
 67                   struct msghdr mh;
 68                   ssize_t n;
 69               #if defined(HAVE_MSG_CONTROL)
 70                   size_t size;
 71                   char* data;
 72                   struct cmsghdr* cmh = CMSG_FIRSTHDR(&mh);
 73               
 74                   /*
 75                    * This control data begins with a cmsghdr struct followed by the data
 76                    * (a descriptor in this case). The union ensures that the data is 
 77                    * aligned suitably for the leading cmsghdr struct. The descriptor 
 78                    * itself is properly aligned since the cmsghdr ends on a boundary 
 79                    * that is suitably aligned for any type (including int).
 80                    *
 81                    *     ControlData = [ cmsghdr | int ]
 82                    */
 83               
 84                   size = CMSG_SPACE(sizeof(int) * count);
 85 kumpf 1.1.4.2     data = (char*)malloc(size);
 86               
 87                   /* Define a msghdr that refers to the control data, which is filled in
 88                    * by calling recvmsg() below.
 89                    */
 90               
 91                   memset(&mh, 0, sizeof(mh));
 92                   mh.msg_control = data;
 93                   mh.msg_controllen = size;
 94               
 95               #else /* !defined(HAVE_MSG_CONTROL) */
 96               
 97                   memset(&mh, 0, sizeof(mh));
 98                   mh.msg_accrights = (caddr_t)descriptors;
 99                   mh.msg_accrightslen = sizeof(int) * count;
100               
101               #endif /* defined(HAVE_MSG_CONTROL) */
102               
103                   /*
104                    * The other process sends a single-byte message. This byte is not
105                    * used since we only need the control data (the descriptor) but we
106 kumpf 1.1.4.2      * must request at least one byte from recvmsg().
107                    */
108               
109                   memset(iov, 0, sizeof(iov));
110                   iov[0].iov_base = &dummy;
111                   iov[0].iov_len = 1;
112                   mh.msg_iov = iov;
113                   mh.msg_iovlen = 1;
114               
115                   /* Receive the message from the other process. */
116               
117                   n = recvmsg(sock, &mh, 0);
118               
119                   if (n <= 0)
120                       return -1;
121               
122                   /* Get a pointer to control message. Return if the header is null or 
123                    * does not contain what we expect.
124                    */
125               
126               #if defined(HAVE_MSG_CONTROL)
127 kumpf 1.1.4.2 
128                   cmh = CMSG_FIRSTHDR(&mh);
129               
130                   if (!cmh || 
131                       cmh->cmsg_len != CMSG_LEN(sizeof(int) * count) ||
132                       cmh->cmsg_level != SOL_SOCKET ||
133                       cmh->cmsg_type != SCM_RIGHTS)
134                   {
135                       return -1;
136                   }
137               
138                   /* Copy the data: */
139               
140                   memcpy(descriptors, CMSG_DATA(cmh), sizeof(int) * count);
141               
142               #else /* !defined(HAVE_MSG_CONTROL) */
143               
144                   if (mh.msg_accrightslen != sizeof(int) * count)
145                       return -1;
146               
147                   memcpy(descriptors, mh.msg_accrights, sizeof(int) * count);
148 kumpf 1.1.4.2 
149               #endif /* defined(HAVE_MSG_CONTROL) */
150               
151                   return 0;
152               }
153               
154               #endif /* _Executor_Socket_h */