1/* coap-server.c -- Example CoAP server using Contiki and libcoap
2 *
3 * Copyright (C) 2011 Olaf Bergmann <bergmann@tzi.org>
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. Neither the name of the Institute nor the names of its contributors
14 *    may be used to endorse or promote products derived from this software
15 *    without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 *
29 * This file is part of the Contiki operating system.
30 *
31 */
32
33#include "contiki-net.h"
34#include "coap3/coap.h"
35
36static coap_context_t *coap_context;
37
38static clock_time_t clock_offset;
39/* changeable clock base (see handle_put_time()) */
40static clock_time_t my_clock_base = 0;
41static coap_resource_t *time_resource = NULL; /* just for testing */
42
43PROCESS(coap_server_process, "CoAP server process");
44AUTOSTART_PROCESSES(&coap_server_process);
45/*---------------------------------------------------------------------------*/
46void
47init_coap_server(coap_context_t **ctx) {
48  uip_ds6_addr_t *my_address;
49  coap_address_t listen_addr;
50
51  assert(ctx);
52
53  my_address = uip_ds6_get_global(ADDR_PREFERRED);
54  uip_ipaddr_copy(&listen_addr.addr, &my_address->ipaddr);
55  coap_address_set_port(&listen_addr, COAP_DEFAULT_PORT);
56
57  *ctx = coap_new_context(&listen_addr);
58
59  if (!*ctx) {
60    coap_log_crit("cannot create CoAP context\r\n");
61  }
62  coap_context_set_max_idle_sessions(*ctx, 2);
63}
64
65/*---------------------------------------------------------------------------*/
66#ifndef min
67# define min(a,b) ((a) < (b) ? (a) : (b))
68#endif
69
70void
71hnd_get_time(coap_resource_t *resource, coap_session_t *session,
72             const coap_pdu_t *request, const coap_string_t *query,
73             coap_pdu_t *response) {
74  unsigned char buf[40];
75  size_t len;
76  coap_tick_t now;
77  coap_tick_t t;
78
79  if (my_clock_base) {
80
81    /* calculate current time */
82    coap_ticks(&t);
83    now = my_clock_base + (t / COAP_TICKS_PER_SECOND);
84
85    if (query != NULL
86        && coap_string_equal(query, coap_make_str_const("ticks"))) {
87      /* output ticks */
88      len = snprintf((char *)buf, sizeof(buf), "%u", (unsigned int)now);
89
90    } else {      /* output human-readable time */
91      struct tm *tmp;
92      time_t tnow = now;
93      tmp = gmtime(&tnow);
94      if (!tmp) {
95        /* If 'tnow' is not valid */
96        coap_pdu_set_code(response, COAP_RESPONSE_CODE_NOT_FOUND);
97        return;
98      } else {
99        len = strftime((char *)buf, sizeof(buf), "%b %d %H:%M:%S", tmp);
100      }
101    }
102    coap_add_data_blocked_response(request, response,
103                                   COAP_MEDIATYPE_TEXT_PLAIN, 1,
104                                   len,
105                                   buf);
106  } else {
107    /* if my_clock_base was deleted, we pretend to have no such resource */
108    coap_pdu_set_code(response, COAP_RESPONSE_CODE_NOT_FOUND);
109  }
110}
111
112void
113init_coap_resources(coap_context_t *ctx) {
114  coap_resource_t *r;
115#if 0
116  r = coap_resource_init(NULL, 0, 0);
117  coap_register_handler(r, COAP_REQUEST_GET, hnd_get_index);
118
119  coap_add_attr(r, coap_make_str_const("ct"), coap_make_str_const("0"), 0);
120  coap_add_attr(r, coap_make_str_const("title"), coap_make_str_const("\"General Info\""), 0);
121  coap_add_resource(ctx, r);
122#endif
123  /* store clock base to use in /time */
124  my_clock_base = clock_offset;
125
126  r = coap_resource_init(coap_make_str_const("time"), 0);
127  if (!r)
128    goto error;
129
130  coap_resource_set_get_observable(r, 1);
131  time_resource = r;
132  coap_register_handler(r, COAP_REQUEST_GET, hnd_get_time);
133#if 0
134  coap_register_handler(r, COAP_REQUEST_PUT, hnd_put_time);
135  coap_register_handler(r, COAP_REQUEST_DELETE, hnd_delete_time);
136#endif
137  coap_add_attr(r, coap_make_str_const("ct"), coap_make_str_const("0"), 0);
138  /* coap_add_attr(r, coap_make_str_const("title"), coap_make_str_const("\"Internal Clock\""), 0); */
139  coap_add_attr(r, coap_make_str_const("rt"), coap_make_str_const("\"ticks\""), 0);
140  coap_add_attr(r, coap_make_str_const("if"), coap_make_str_const("\"clock\""), 0);
141
142  coap_add_resource(ctx, r);
143#if 0
144  if (coap_async_is_supported()) {
145    r = coap_resource_init(coap_make_str_const("async"), 0);
146    coap_register_handler(r, COAP_REQUEST_GET, hnd_get_async);
147
148    coap_add_attr(r, coap_make_str_const("ct"), coap_make_str_const("0"), 0);
149    coap_add_resource(ctx, r);
150  }
151#endif
152
153  return;
154error:
155  coap_log_crit("cannot create resource\n");
156}
157
158/* struct etimer notify_timer; */
159struct etimer dirty_timer;
160
161/*---------------------------------------------------------------------------*/
162PROCESS_THREAD(coap_server_process, ev, data) {
163  PROCESS_BEGIN();
164
165  /* Initialize libcoap library */
166  coap_startup();
167
168  clock_offset = clock_time();
169  init_coap_server(&coap_context);
170
171  if (!coap_context) {
172    coap_log_emerg("cannot create context\n");
173    PROCESS_EXIT();
174  }
175
176  init_coap_resources(coap_context);
177
178  /* etimer_set(&notify_timer, 5 * CLOCK_SECOND); */
179  etimer_set(&dirty_timer, 30 * CLOCK_SECOND);
180
181  while (1) {
182    PROCESS_YIELD();
183    if (ev == PROCESS_EVENT_TIMER && etimer_expired(&dirty_timer)) {
184      coap_resource_notify_observers(time_resource, NULL);
185      etimer_reset(&dirty_timer);
186    }
187  }
188  coap_cleanup();
189
190  PROCESS_END();
191}
192/*---------------------------------------------------------------------------*/
193