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