minix/lib/libc/sys/socketpair.c

   1 #include <sys/cdefs.h>
   2 #include "namespace.h"
   3 #include <lib.h>
   4
   5 #include <string.h>
   6 #include <errno.h>
   7 #include <stdio.h>
   8 #include <fcntl.h>
   9 #include <unistd.h>
  10 #include <net/netlib.h>
  11 #include <sys/ioctl.h>
  12 #include <sys/ioc_net.h>
  13 #include <sys/socket.h>
  14 #include <sys/stat.h>
  15 #include <sys/un.h>
  16
  17 #define DEBUG 0
  18
  19 static int _uds_socketpair(int type, int protocol, int sv[2]);
  20
  21 /*
  22  * Create a pair of connected sockets.
  23  */
  24 static int
  25 __socketpair(int domain, int type, int protocol, int sv[2])
  26 {
  27         message m;
  28
  29         memset(&m, 0, sizeof(m));
  30         m.m_lc_vfs_socket.domain = domain;
  31         m.m_lc_vfs_socket.type = type;
  32         m.m_lc_vfs_socket.protocol = protocol;
  33
  34         if (_syscall(VFS_PROC_NR, VFS_SOCKETPAIR, &m) < 0)
  35                 return -1;
  36
  37         sv[0] = m.m_vfs_lc_fdpair.fd0;
  38         sv[1] = m.m_vfs_lc_fdpair.fd1;
  39         return 0;
  40 }
  41
  42 int
  43 socketpair(int domain, int type, int protocol, int sv[2])
  44 {
  45         int r;
  46
  47         r = __socketpair(domain, type, protocol, sv);
  48         if (r != -1 || (errno != EAFNOSUPPORT && errno != ENOSYS))
  49                 return r;
  50
  51 #if DEBUG
  52         fprintf(stderr, "socketpair: domain %d, type %d, protocol %d\n",
  53                 domain, type, protocol);
  54 #endif
  55
  56         if (domain == AF_UNIX)
  57                 return _uds_socketpair(type, protocol, sv);
  58
  59         errno = EAFNOSUPPORT;
  60         return -1;
  61 }
  62
  63 static int _uds_socketpair(int type, int protocol, int sv[2])
  64 {
  65         dev_t dev;
  66         int r, i;
  67         struct stat sbuf;
  68
  69         if (type != SOCK_STREAM && type != SOCK_SEQPACKET) {
  70                 errno = EPROTOTYPE;
  71                 return -1;
  72         }
  73
  74         if (protocol != 0)
  75         {
  76 #if DEBUG
  77                 fprintf(stderr, "socketpair(uds): bad protocol %d\n", protocol);
  78 #endif
  79                 errno= EPROTONOSUPPORT;
  80                 return -1;
  81         }
  82
  83         /* in this 'for' loop two unconnected sockets are created */
  84         for (i = 0; i < 2; i++) {
  85                 sv[i]= open(UDS_DEVICE, O_RDWR);
  86                 if (sv[i] == -1) {
  87                         int open_errno = errno;
  88
  89                         if (i == 1) {
  90                                 /* if we failed to open() the 2nd
  91                                  * socket, we need to close the 1st
  92                                  */
  93                                 close(sv[0]);
  94                                 errno = open_errno;
  95                         }
  96
  97                         return -1;
  98                 }
  99
 100                 /* set the type for the socket via ioctl
 101                  * (SOCK_STREAM, SOCK_SEQPACKET, etc)
 102                  */
 103                 r= ioctl(sv[i], NWIOSUDSTYPE, &type);
 104                 if (r == -1) {
 105                         int ioctl_errno;
 106
 107                         /* if that failed rollback socket creation */
 108                         ioctl_errno= errno;
 109                         close(sv[i]);
 110
 111                         if (i == 1) {
 112                                 /* if we just closed the 2nd socket, we
 113                                  * need to close the 1st
 114                                  */
 115                                 close(sv[0]);
 116                         }
 117
 118                         /* return the error thrown by the call to ioctl */
 119                         errno= ioctl_errno;
 120                         return -1;
 121                 }
 122         }
 123
 124         r= fstat(sv[1], &sbuf);
 125         if (r == -1) {
 126                 int fstat_errno;
 127
 128                 /* if that failed rollback socket creation */
 129                 fstat_errno= errno;
 130
 131                 close(sv[0]);
 132                 close(sv[1]);
 133
 134                 /* return the error thrown by the call to fstat */
 135                 errno= fstat_errno;
 136                 return -1;
 137         }
 138
 139         dev = sbuf.st_rdev;
 140
 141         /* connect the sockets sv[0] and sv[1] */
 142         r= ioctl(sv[0], NWIOSUDSPAIR, &dev);
 143         if (r == -1) {
 144                 int ioctl_errno;
 145
 146                 /* if that failed rollback socket creation */
 147                 ioctl_errno= errno;
 148
 149                 close(sv[0]);
 150                 close(sv[1]);
 151
 152                 /* return the error thrown by the call to ioctl */
 153                 errno= ioctl_errno;
 154                 return -1;
 155         }
 156
 157
 158         return 0;
 159 }