1 /* async.c -- state management for asynchronous messages
2 *
3 * Copyright (C) 2010,2011 Olaf Bergmann <bergmann@tzi.org>
4 *
5 * This file is part of the CoAP library libcoap. Please see
6 * README for terms of use.
7 */
8
9 /**
10 * @file async.c
11 * @brief state management for asynchronous messages
12 */
13
14 #ifndef WITHOUT_ASYNC
15
16 #include "coap_config.h"
17 #include "coap.h"
18 #include "async.h"
19 #include "debug.h"
20 #include "mem.h"
21 #include "utlist.h"
22
23 coap_async_state_t *
coap_register_async(coap_context_t * context,coap_address_t * peer,coap_pdu_t * request,unsigned char flags,void * data)24 coap_register_async(coap_context_t *context, coap_address_t *peer,
25 coap_pdu_t *request, unsigned char flags, void *data) {
26 coap_async_state_t *s;
27 coap_tid_t id;
28
29 coap_transaction_id(peer, request, &id);
30 LL_SEARCH_SCALAR(context->async_state,s,id,id);
31
32 if (s != NULL) {
33 /* We must return NULL here as the caller must know that he is
34 * responsible for releasing @p data. */
35 debug("asynchronous state for transaction %d already registered\n", id);
36 return NULL;
37 }
38
39 /* store information for handling the asynchronous task */
40 s = (coap_async_state_t *)coap_malloc(sizeof(coap_async_state_t) +
41 request->hdr->token_length);
42 if (!s) {
43 coap_log(LOG_CRIT, "coap_register_async: insufficient memory\n");
44 return NULL;
45 }
46
47 memset(s, 0, sizeof(coap_async_state_t) + request->hdr->token_length);
48
49 /* set COAP_ASYNC_CONFIRM according to request's type */
50 s->flags = flags & ~COAP_ASYNC_CONFIRM;
51 if (request->hdr->type == COAP_MESSAGE_CON)
52 s->flags |= COAP_ASYNC_CONFIRM;
53
54 s->appdata = data;
55
56 memcpy(&s->peer, peer, sizeof(coap_address_t));
57
58 if (request->hdr->token_length) {
59 s->tokenlen = request->hdr->token_length;
60 memcpy(s->token, request->hdr->token, request->hdr->token_length);
61 }
62
63 memcpy(&s->id, &id, sizeof(coap_tid_t));
64
65 coap_touch_async(s);
66
67 LL_PREPEND(context->async_state, s);
68
69 return s;
70 }
71
72 coap_async_state_t *
coap_find_async(coap_context_t * context,coap_tid_t id)73 coap_find_async(coap_context_t *context, coap_tid_t id) {
74 coap_async_state_t *tmp;
75 LL_SEARCH_SCALAR(context->async_state,tmp,id,id);
76 return tmp;
77 }
78
79 int
coap_remove_async(coap_context_t * context,coap_tid_t id,coap_async_state_t ** s)80 coap_remove_async(coap_context_t *context, coap_tid_t id,
81 coap_async_state_t **s) {
82 coap_async_state_t *tmp = coap_find_async(context, id);
83
84 if (tmp)
85 LL_DELETE(context->async_state,tmp);
86
87 *s = tmp;
88 return tmp != NULL;
89 }
90
91 void
coap_free_async(coap_async_state_t * s)92 coap_free_async(coap_async_state_t *s) {
93 if (s && (s->flags & COAP_ASYNC_RELEASE_DATA) != 0)
94 coap_free(s->appdata);
95 coap_free(s);
96 }
97
98 #else
99 void does_not_exist(); /* make some compilers happy */
100 #endif /* WITHOUT_ASYNC */
101
