external/ibm-public/postfix/dist/src/util/stream_recv_fd.c

   1 /*      $NetBSD$        */
   2
   3 /*++
   4 /* NAME
   5 /*      stream_recv_fd 3
   6 /* SUMMARY
   7 /*      receive file descriptor
   8 /* SYNOPSIS
   9 /*      #include <iostuff.h>
  10 /*
  11 /*      int     stream_recv_fd(fd)
  12 /*      int     fd;
  13 /* DESCRIPTION
  14 /*      stream_recv_fd() receives a file descriptor via the specified
  15 /*      stream. The result value is the received descriptor.
  16 /*
  17 /*      Arguments:
  18 /* .IP fd
  19 /*      File descriptor.
  20 /* DIAGNOSTICS
  21 /*      stream_recv_fd() returns -1 upon failure.
  22 /* LICENSE
  23 /* .ad
  24 /* .fi
  25 /*      The Secure Mailer license must be distributed with this software.
  26 /* AUTHOR(S)
  27 /*      Wietse Venema
  28 /*      IBM T.J. Watson Research
  29 /*      P.O. Box 704
  30 /*      Yorktown Heights, NY 10598, USA
  31 /*--*/
  32
  33 /* System library. */
  34
  35 #include <sys_defs.h>                   /* includes <sys/types.h> */
  36
  37 #ifdef STREAM_CONNECTIONS
  38
  39 #include <sys/stat.h>
  40 #include <unistd.h>
  41 #include <errno.h>
  42 #include <stropts.h>
  43 #include <fcntl.h>
  44
  45 #endif
  46
  47 /* Utility library. */
  48
  49 #include <msg.h>
  50 #include <iostuff.h>
  51
  52 /* stream_recv_fd - receive file descriptor */
  53
  54 int     stream_recv_fd(int fd)
  55 {
  56 #ifdef STREAM_CONNECTIONS
  57     struct strrecvfd fdinfo;
  58
  59     /*
  60      * This will return EAGAIN on a non-blocking stream when someone else
  61      * snatched the connection from us.
  62      */
  63     if (ioctl(fd, I_RECVFD, &fdinfo) < 0)
  64         return (-1);
  65     return (fdinfo.fd);
  66 #else
  67     msg_fatal("stream connections are not implemented");
  68 #endif
  69 }
  70
  71 #ifdef TEST
  72
  73  /*
  74   * Proof-of-concept program. Receive a descriptor (presumably from the
  75   * stream_send_fd test program) and copy its content until EOF.
  76   */
  77 #include <unistd.h>
  78 #include <string.h>
  79 #include <stdlib.h>
  80 #include <split_at.h>
  81 #include <listen.h>
  82
  83 int     main(int argc, char **argv)
  84 {
  85     char   *transport;
  86     char   *endpoint;
  87     int     listen_sock;
  88     int     client_sock;
  89     int     client_fd;
  90     ssize_t read_count;
  91     char    buf[1024];
  92
  93     if (argc != 2
  94         || (endpoint = split_at(transport = argv[1], ':')) == 0
  95         || *endpoint == 0 || *transport == 0)
  96         msg_fatal("usage: %s transport:endpoint", argv[0]);
  97
  98     if (strcmp(transport, "stream") == 0) {
  99         listen_sock = stream_listen(endpoint, BLOCKING, 0);
 100     } else {
 101         msg_fatal("invalid transport name: %s", transport);
 102     }
 103     if (listen_sock < 0)
 104         msg_fatal("listen %s:%s: %m", transport, endpoint);
 105
 106     client_sock = stream_accept(listen_sock);
 107     if (client_sock < 0)
 108         msg_fatal("stream_accept: %m");
 109
 110     while ((client_fd = stream_recv_fd(client_sock)) >= 0) {
 111         msg_info("client_fd = %d", client_fd);
 112         while ((read_count = read(client_fd, buf, sizeof(buf))) > 0)
 113             write(1, buf, read_count);
 114         if (read_count < 0)
 115             msg_fatal("read: %m");
 116         if (close(client_fd) != 0)
 117             msg_fatal("close(%d): %m", client_fd);
 118     }
 119     exit(0);
 120 }
 121
 122 #endif