lib/libc/sys-minix/socketpair.c

   1 #include <sys/cdefs.h>
   2 #include "namespace.h"
   3
   4 #include <errno.h>
   5 #include <stdio.h>
   6 #include <fcntl.h>
   7 #include <unistd.h>
   8 #include <net/netlib.h>
   9 #include <sys/ioc_net.h>
  10 #include <sys/socket.h>
  11 #include <sys/stat.h>
  12 #include <sys/un.h>
  13
  14 #ifdef __weak_alias
  15 __weak_alias(socketpair, _socketpair)
  16 #endif
  17
  18 #define DEBUG 0
  19
  20 static int _uds_socketpair(int type, int protocol, int sv[2]);
  21
  22 /*
  23  * Create a pair of connected sockets
  24  */
  25 int socketpair(int domain, int type, int protocol, int sv[2]) {
  26
  27 #if DEBUG
  28         fprintf(stderr, "socketpair: domain %d, type %d, protocol %d\n",
  29                 domain, type, protocol);
  30 #endif
  31
  32         if (domain != AF_UNIX)
  33         {
  34                 errno = EAFNOSUPPORT;
  35                 return -1;
  36         }
  37
  38         if (domain == AF_UNIX &&
  39                         (type == SOCK_STREAM || type == SOCK_SEQPACKET))
  40                 return _uds_socketpair(type, protocol, sv);
  41
  42 #if DEBUG
  43         fprintf(stderr,
  44                 "socketpair: nothing for domain %d, type %d, protocol %d\n",
  45                 domain, type, protocol);
  46 #endif
  47
  48         errno= EPROTOTYPE;
  49         return -1;
  50 }
  51
  52 static int _uds_socketpair(int type, int protocol, int sv[2])
  53 {
  54         dev_t dev;
  55         int r, i;
  56         struct stat sbuf;
  57
  58         if (protocol != 0)
  59         {
  60 #if DEBUG
  61                 fprintf(stderr, "socketpair(uds): bad protocol %d\n", protocol);
  62 #endif
  63                 errno= EPROTONOSUPPORT;
  64                 return -1;
  65         }
  66
  67         /* in this 'for' loop two unconnected sockets are created */
  68         for (i = 0; i < 2; i++) {
  69                 sv[i]= open(UDS_DEVICE, O_RDWR);
  70                 if (sv[i] == -1) {
  71                         int open_errno = errno;
  72
  73                         if (i == 1) {
  74                                 /* if we failed to open() the 2nd
  75                                  * socket, we need to close the 1st
  76                                  */
  77                                 close(sv[0]);
  78                                 errno = open_errno;
  79                         }
  80
  81                         return -1;
  82                 }
  83
  84                 /* set the type for the socket via ioctl
  85                  * (SOCK_STREAM, SOCK_SEQPACKET, etc)
  86                  */
  87                 r= ioctl(sv[i], NWIOSUDSTYPE, &type);
  88                 if (r == -1) {
  89                         int ioctl_errno;
  90
  91                         /* if that failed rollback socket creation */
  92                         ioctl_errno= errno;
  93                         close(sv[i]);
  94
  95                         if (i == 1) {
  96                                 /* if we just closed the 2nd socket, we
  97                                  * need to close the 1st
  98                                  */
  99                                 close(sv[0]);
 100                         }
 101
 102                         /* return the error thrown by the call to ioctl */
 103                         errno= ioctl_errno;
 104                         return -1;
 105                 }
 106         }
 107
 108         r= fstat(sv[1], &sbuf);
 109         if (r == -1) {
 110                 int fstat_errno;
 111
 112                 /* if that failed rollback socket creation */
 113                 fstat_errno= errno;
 114
 115                 close(sv[0]);
 116                 close(sv[1]);
 117
 118                 /* return the error thrown by the call to fstat */
 119                 errno= fstat_errno;
 120                 return -1;
 121         }
 122
 123         dev = sbuf.st_dev;
 124
 125         /* connect the sockets sv[0] and sv[1] */
 126         r= ioctl(sv[0], NWIOSUDSPAIR, &dev);
 127         if (r == -1) {
 128                 int ioctl_errno;
 129
 130                 /* if that failed rollback socket creation */
 131                 ioctl_errno= errno;
 132
 133                 close(sv[0]);
 134                 close(sv[1]);
 135
 136                 /* return the error thrown by the call to ioctl */
 137                 errno= ioctl_errno;
 138                 return -1;
 139         }
 140
 141
 142         return 0;
 143 }