server/pipe.c

   1 /*
   2  * Server-side pipe management
   3  *
   4  * Copyright (C) 1998 Alexandre Julliard
   5  */
   6
   7 #include "config.h"
   8
   9 #include <assert.h>
  10 #include <fcntl.h>
  11 #include <string.h>
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14 #ifdef HAVE_SYS_ERRNO_H
  15 #include <sys/errno.h>
  16 #endif
  17 #include <sys/stat.h>
  18 #include <sys/time.h>
  19 #include <sys/types.h>
  20 #include <time.h>
  21 #include <unistd.h>
  22
  23 #include "winbase.h"
  24
  25 #include "handle.h"
  26 #include "thread.h"
  27 #include "request.h"
  28
  29 enum side { READ_SIDE, WRITE_SIDE };
  30
  31 struct pipe
  32 {
  33     struct object       obj;         /* object header */
  34     struct pipe        *other;       /* the pipe other end */
  35     enum side           side;        /* which side of the pipe is this */
  36 };
  37
  38 static void pipe_dump( struct object *obj, int verbose );
  39 static int pipe_get_poll_events( struct object *obj );
  40 static int pipe_get_fd( struct object *obj );
  41 static int pipe_get_info( struct object *obj, struct get_file_info_request *req );
  42 static void pipe_destroy( struct object *obj );
  43
  44 static const struct object_ops pipe_ops =
  45 {
  46     sizeof(struct pipe),          /* size */
  47     pipe_dump,                    /* dump */
  48     default_poll_add_queue,       /* add_queue */
  49     default_poll_remove_queue,    /* remove_queue */
  50     default_poll_signaled,        /* signaled */
  51     no_satisfied,                 /* satisfied */
  52     pipe_get_poll_events,         /* get_poll_events */
  53     default_poll_event,           /* poll_event */
  54     pipe_get_fd,                  /* get_fd */
  55     no_flush,                     /* flush */
  56     pipe_get_info,                /* get_file_info */
  57     pipe_destroy                  /* destroy */
  58 };
  59
  60
  61 static struct pipe *create_pipe_side( int fd, int side )
  62 {
  63     struct pipe *pipe;
  64
  65     if ((pipe = alloc_object( &pipe_ops, fd )))
  66     {
  67         pipe->other  = NULL;
  68         pipe->side   = side;
  69     }
  70     return pipe;
  71 }
  72
  73 static int create_pipe( struct object *obj[2] )
  74 {
  75     struct pipe *read_pipe;
  76     struct pipe *write_pipe;
  77     int fd[2];
  78
  79     if (pipe( fd ) == -1)
  80     {
  81         file_set_error();
  82         return 0;
  83     }
  84     if ((read_pipe = create_pipe_side( fd[0], READ_SIDE )))
  85     {
  86         if ((write_pipe = create_pipe_side( fd[1], WRITE_SIDE )))
  87         {
  88             write_pipe->other = read_pipe;
  89             read_pipe->other  = write_pipe;
  90             obj[0] = &read_pipe->obj;
  91             obj[1] = &write_pipe->obj;
  92             return 1;
  93         }
  94         release_object( read_pipe );
  95     }
  96     else close( fd[1] );
  97     return 0;
  98 }
  99
 100 static void pipe_dump( struct object *obj, int verbose )
 101 {
 102     struct pipe *pipe = (struct pipe *)obj;
 103     assert( obj->ops == &pipe_ops );
 104     fprintf( stderr, "Pipe %s-side fd=%d\n",
 105              (pipe->side == READ_SIDE) ? "read" : "write", pipe->obj.fd );
 106 }
 107
 108 static int pipe_get_poll_events( struct object *obj )
 109 {
 110     struct pipe *pipe = (struct pipe *)obj;
 111     assert( obj->ops == &pipe_ops );
 112     return (pipe->side == READ_SIDE) ? POLLIN : POLLOUT;
 113 }
 114
 115 static int pipe_get_fd( struct object *obj )
 116 {
 117     struct pipe *pipe = (struct pipe *)obj;
 118     assert( obj->ops == &pipe_ops );
 119
 120     if (!pipe->other)
 121     {
 122         set_error( STATUS_PIPE_BROKEN );
 123         return -1;
 124     }
 125     return pipe->obj.fd;
 126 }
 127
 128 static int pipe_get_info( struct object *obj, struct get_file_info_request *req )
 129 {
 130     req->type        = FILE_TYPE_PIPE;
 131     req->attr        = 0;
 132     req->access_time = 0;
 133     req->write_time  = 0;
 134     req->size_high   = 0;
 135     req->size_low    = 0;
 136     req->links       = 0;
 137     req->index_high  = 0;
 138     req->index_low   = 0;
 139     req->serial      = 0;
 140     return 1;
 141 }
 142
 143 static void pipe_destroy( struct object *obj )
 144 {
 145     struct pipe *pipe = (struct pipe *)obj;
 146     assert( obj->ops == &pipe_ops );
 147
 148     if (pipe->other) pipe->other->other = NULL;
 149 }
 150
 151 /* create an anonymous pipe */
 152 DECL_HANDLER(create_pipe)
 153 {
 154     struct object *obj[2];
 155     int hread = -1, hwrite = -1;
 156
 157     if (create_pipe( obj ))
 158     {
 159         hread = alloc_handle( current->process, obj[0],
 160                               STANDARD_RIGHTS_REQUIRED|SYNCHRONIZE|GENERIC_READ,
 161                               req->inherit );
 162         if (hread != -1)
 163         {
 164             hwrite = alloc_handle( current->process, obj[1],
 165                                    STANDARD_RIGHTS_REQUIRED|SYNCHRONIZE|GENERIC_WRITE,
 166                                    req->inherit );
 167             if (hwrite == -1)
 168                 close_handle( current->process, hread, NULL );
 169         }
 170         release_object( obj[0] );
 171         release_object( obj[1] );
 172     }
 173     req->handle_read  = hread;
 174     req->handle_write = hwrite;
 175 }