1/*
2 * $Id: dsi_attn.c,v 1.8 2009-10-25 06:13:11 didg Exp $
3 *
4 * Copyright (c) 1997 Adrian Sun (asun@zoology.washington.edu)
5 * All rights reserved. See COPYRIGHT.
6 */
7
8#ifdef HAVE_CONFIG_H
9#include "config.h"
10#endif /* HAVE_CONFIG_H */
11
12#include <stdio.h>
13#include <string.h>
14#include <signal.h>
15#include <sys/types.h>
16
17#include <atalk/dsi.h>
18#include <atalk/afp.h>
19#include <netatalk/endian.h>
20
21#ifndef MIN
22#define MIN(a,b) ((a) < (b) ? (a) : (b))
23#endif /* MIN */
24
25/* send an attention. this may get called at any time, so we can't use
26 * DSI buffers to send one.
27   return 0 on error
28
29 */
30int dsi_attention(DSI *dsi, AFPUserBytes flags)
31{
32  /* header + AFPUserBytes */
33  char block[DSI_BLOCKSIZ + sizeof(AFPUserBytes)];
34  u_int32_t len, nlen;
35  u_int16_t id;
36
37  if (dsi->flags & DSI_SLEEPING)
38      return 1;
39
40  if (dsi->in_write) {
41      return -1;
42  }
43  id = htons(dsi_serverID(dsi));
44  flags = htons(flags);
45  len = MIN(sizeof(flags), dsi->attn_quantum);
46  nlen = htonl(len);
47
48  memset(block, 0, sizeof(block));
49  block[0] = DSIFL_REQUEST; /* sending a request */
50  block[1] = DSIFUNC_ATTN;  /* it's an attention */
51  memcpy(block + 2, &id, sizeof(id));
52  /* code = 0 */
53  memcpy(block + 8, &nlen, sizeof(nlen));
54  memcpy(block + 16, &flags, sizeof(flags));
55  /* reserved = 0 */
56
57  /* send an attention */
58  return dsi_stream_write(dsi, block, DSI_BLOCKSIZ + len, DSI_NOWAIT);
59}
60