server/pipe.c

   1 /*
   2  * Server-side pipe management
   3  *
   4  * Copyright (C) 1998 Alexandre Julliard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20
  21 #include "config.h"
  22
  23 #include <assert.h>
  24 #include <fcntl.h>
  25 #include <string.h>
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <sys/time.h>
  29 #include <sys/types.h>
  30 #include <time.h>
  31 #include <unistd.h>
  32
  33 #include "winbase.h"
  34
  35 #include "file.h"
  36 #include "handle.h"
  37 #include "thread.h"
  38 #include "request.h"
  39
  40 enum side { READ_SIDE, WRITE_SIDE };
  41
  42 struct pipe
  43 {
  44     struct object       obj;         /* object header */
  45     struct fd          *fd;          /* pipe file descriptor */
  46     struct pipe        *other;       /* the pipe other end */
  47     enum side           side;        /* which side of the pipe is this */
  48 };
  49
  50 static void pipe_dump( struct object *obj, int verbose );
  51 static struct fd *pipe_get_fd( struct object *obj );
  52 static void pipe_destroy( struct object *obj );
  53
  54 static int pipe_get_poll_events( struct fd *fd );
  55 static int pipe_get_info( struct fd *fd, struct get_file_info_reply *reply, int *flags );
  56
  57 static const struct object_ops pipe_ops =
  58 {
  59     sizeof(struct pipe),          /* size */
  60     pipe_dump,                    /* dump */
  61     default_fd_add_queue,         /* add_queue */
  62     default_fd_remove_queue,      /* remove_queue */
  63     default_fd_signaled,          /* signaled */
  64     no_satisfied,                 /* satisfied */
  65     pipe_get_fd,                  /* get_fd */
  66     pipe_destroy                  /* destroy */
  67 };
  68
  69 static const struct fd_ops pipe_fd_ops =
  70 {
  71     pipe_get_poll_events,         /* get_poll_events */
  72     default_poll_event,           /* poll_event */
  73     no_flush,                     /* flush */
  74     pipe_get_info,                /* get_file_info */
  75     no_queue_async                /* queue_async */
  76 };
  77
  78
  79 static struct pipe *create_pipe_side( int fd, int side )
  80 {
  81     struct pipe *pipe;
  82
  83     if ((pipe = alloc_object( &pipe_ops )))
  84     {
  85         pipe->other  = NULL;
  86         pipe->side   = side;
  87     }
  88     if (!(pipe->fd = create_anonymous_fd( &pipe_fd_ops, fd, &pipe->obj )))
  89     {
  90         release_object( pipe );
  91         return NULL;
  92     }
  93     return pipe;
  94 }
  95
  96 static int create_pipe( struct object *obj[2] )
  97 {
  98     struct pipe *read_pipe;
  99     struct pipe *write_pipe;
 100     int fd[2];
 101
 102     if (pipe( fd ) == -1)
 103     {
 104         file_set_error();
 105         return 0;
 106     }
 107     if ((read_pipe = create_pipe_side( fd[0], READ_SIDE )))
 108     {
 109         if ((write_pipe = create_pipe_side( fd[1], WRITE_SIDE )))
 110         {
 111             write_pipe->other = read_pipe;
 112             read_pipe->other  = write_pipe;
 113             obj[0] = &read_pipe->obj;
 114             obj[1] = &write_pipe->obj;
 115             return 1;
 116         }
 117         release_object( read_pipe );
 118     }
 119     else close( fd[1] );
 120     return 0;
 121 }
 122
 123 static void pipe_dump( struct object *obj, int verbose )
 124 {
 125     struct pipe *pipe = (struct pipe *)obj;
 126     assert( obj->ops == &pipe_ops );
 127     fprintf( stderr, "Pipe %s-side fd=%p\n",
 128              (pipe->side == READ_SIDE) ? "read" : "write", pipe->fd );
 129 }
 130
 131 static int pipe_get_poll_events( struct fd *fd )
 132 {
 133     struct pipe *pipe = get_fd_user( fd );
 134     assert( pipe->obj.ops == &pipe_ops );
 135     return (pipe->side == READ_SIDE) ? POLLIN : POLLOUT;
 136 }
 137
 138 static struct fd *pipe_get_fd( struct object *obj )
 139 {
 140     struct pipe *pipe = (struct pipe *)obj;
 141     assert( obj->ops == &pipe_ops );
 142
 143     if (!pipe->other)
 144     {
 145         set_error( STATUS_PIPE_BROKEN );
 146         return NULL;
 147     }
 148     return (struct fd *)grab_object( pipe->fd );
 149 }
 150
 151 static int pipe_get_info( struct fd *fd, struct get_file_info_reply *reply, int *flags )
 152 {
 153     if (reply)
 154     {
 155         reply->type        = FILE_TYPE_PIPE;
 156         reply->attr        = 0;
 157         reply->access_time = 0;
 158         reply->write_time  = 0;
 159         reply->size_high   = 0;
 160         reply->size_low    = 0;
 161         reply->links       = 0;
 162         reply->index_high  = 0;
 163         reply->index_low   = 0;
 164         reply->serial      = 0;
 165     }
 166     *flags = 0;
 167     return FD_TYPE_DEFAULT;
 168 }
 169
 170 static void pipe_destroy( struct object *obj )
 171 {
 172     struct pipe *pipe = (struct pipe *)obj;
 173     assert( obj->ops == &pipe_ops );
 174
 175     if (pipe->other) pipe->other->other = NULL;
 176     if (pipe->fd) release_object( pipe->fd );
 177 }
 178
 179 /* create an anonymous pipe */
 180 DECL_HANDLER(create_pipe)
 181 {
 182     struct object *obj[2];
 183     obj_handle_t hread = 0, hwrite = 0;
 184
 185     if (create_pipe( obj ))
 186     {
 187         hread = alloc_handle( current->process, obj[0],
 188                               STANDARD_RIGHTS_REQUIRED|SYNCHRONIZE|GENERIC_READ,
 189                               req->inherit );
 190         if (hread)
 191         {
 192             hwrite = alloc_handle( current->process, obj[1],
 193                                    STANDARD_RIGHTS_REQUIRED|SYNCHRONIZE|GENERIC_WRITE,
 194                                    req->inherit );
 195             if (!hwrite) close_handle( current->process, hread, NULL );
 196         }
 197         release_object( obj[0] );
 198         release_object( obj[1] );
 199     }
 200     reply->handle_read  = hread;
 201     reply->handle_write = hwrite;
 202 }