1 /* tiny -- tiny sender
2 *
3 * Copyright (C) 2010,2011 Olaf Bergmann <bergmann@tzi.org>
4 *
5 * SPDX-License-Identifier: BSD-2-Clause
6 *
7 * This file is part of the CoAP library libcoap. Please see
8 * README for terms of use.
9 */
10
11 #include <string.h>
12 #include <stdlib.h>
13 #include <stdio.h>
14 #include <ctype.h>
15 #include <limits.h>
16 #include <sys/select.h>
17 #include <sys/types.h>
18 #include <sys/socket.h>
19 #include <netinet/in.h>
20 #include <arpa/inet.h>
21 #include <netdb.h>
22 #include <signal.h>
23
24 #include <coap3/coap.h>
25
26 #define Nn 8 /* duplicate definition of N if built on sky motes */
27 #define ENCODE_HEADER_SIZE 4
28 #define HIBIT (1 << (Nn - 1))
29 #define EMASK ((1 << ENCODE_HEADER_SIZE) - 1)
30 #define MMASK ((1 << Nn) - 1 - EMASK)
31 #define MAX_VALUE ( (1 << Nn) - (1 << ENCODE_HEADER_SIZE) ) * (1 << ((1 << ENCODE_HEADER_SIZE) - 1))
32
33 #define COAP_PSEUDOFP_DECODE_8_4(r) (r < HIBIT ? r : (r & MMASK) << (r & EMASK))
34
35 /* ls and s must be integer variables */
36 /* #define COAP_PSEUDOFP_ENCODE_8_4_DOWN(v,ls) (v < HIBIT ? v : (ls = coap_fls(v) - Nn, (v >> ls) & MMASK) + ls) */
37 COAP_STATIC_INLINE unsigned char
COAP_PSEUDOFP_ENCODE_8_4_DOWN(unsigned int v,int * ls)38 COAP_PSEUDOFP_ENCODE_8_4_DOWN(unsigned int v, int *ls) {
39 if (v < HIBIT) return v;
40 *ls = coap_fls(v) - Nn;
41 return ((v >> *ls) & MMASK) + *ls;
42 }
43 #define COAP_PSEUDOFP_ENCODE_8_4_UP(v,ls,s) (v < HIBIT ? v : (ls = coap_fls(v) - Nn, (s = (((v + ((1<<ENCODE_HEADER_SIZE<<ls)-1)) >> ls) & MMASK)), s == 0 ? HIBIT + ls + 1 : s + ls))
44
45 static coap_mid_t id;
46 static int quit = 0;
47
48 /* SIGINT handler: set quit to 1 for graceful termination */
49 static void
handle_sigint(int signum COAP_UNUSED)50 handle_sigint(int signum COAP_UNUSED) {
51 quit = 1;
52 }
53
54 static coap_pdu_t *
make_pdu(unsigned int value)55 make_pdu( unsigned int value ) {
56 coap_pdu_t *pdu;
57 unsigned char enc;
58 static unsigned char buf[20];
59 int len, ls;
60
61 if (!(pdu = coap_pdu_init(COAP_MESSAGE_NON, COAP_REQUEST_CODE_POST, id++,
62 COAP_DEFAULT_MTU)))
63 return NULL;
64
65 enc = COAP_PSEUDOFP_ENCODE_8_4_DOWN(value, &ls);
66
67 len = sprintf((char *)buf, "%c%u", enc, COAP_PSEUDOFP_DECODE_8_4(enc));
68 coap_add_data( pdu, len, buf );
69
70 return pdu;
71 }
72
73 static void
usage(const char * program)74 usage( const char *program ) {
75 const char *p;
76
77 p = strrchr( program, '/' );
78 if ( p )
79 program = ++p;
80
81 fprintf( stderr, "%s -- tiny fake sensor\n"
82 "(c) 2010 Olaf Bergmann <bergmann@tzi.org>\n\n"
83 "usage: %s [group address]\n"
84 "\n\nSends some fake sensor values to specified multicast group\n",
85 program, program );
86 }
87
88 static coap_session_t *
get_session(coap_context_t * ctx,const char * group)89 get_session(coap_context_t *ctx, const char *group) {
90 int s;
91 struct addrinfo hints;
92 struct addrinfo *result, *rp;
93 coap_session_t *session;
94 int hops = 16;
95
96 if (!ctx)
97 return NULL;
98
99 memset(&hints, 0, sizeof(struct addrinfo));
100 hints.ai_family = AF_UNSPEC; /* Allow IPv4 or IPv6 */
101 hints.ai_socktype = SOCK_DGRAM; /* Coap uses UDP */
102 hints.ai_flags = AI_PASSIVE | AI_NUMERICHOST | AI_NUMERICSERV | AI_ALL;
103
104 s = getaddrinfo(group, NULL, &hints, &result);
105 if ( s != 0 ) {
106 fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(s));
107 return NULL;
108 }
109
110 /* iterate through results until success */
111 for (rp = result; rp != NULL; rp = rp->ai_next) {
112 coap_address_t addr;
113 coap_address_init(&addr);
114 addr.size = rp->ai_addrlen;
115 memcpy(&addr.addr, rp->ai_addr, rp->ai_addrlen);
116
117 session = coap_new_client_session(ctx, NULL, &addr, COAP_PROTO_UDP);
118 if (!session)
119 continue;
120
121 if (IN6_IS_ADDR_MULTICAST(&addr.addr.sin6.sin6_addr) ) {
122 /* set socket options for multicast */
123 if (!coap_mcast_set_hops(session, hops))
124 perror("setsockopt: IPV6_MULTICAST_HOPS");
125
126 }
127 freeaddrinfo(result);
128 return session;
129 }
130
131 fprintf(stderr, "no session available for group '%s'\n", group);
132 freeaddrinfo(result);
133 return NULL;
134 }
135
136 int
main(int argc,char ** argv)137 main(int argc, char **argv) {
138 struct timeval tv;
139 coap_pdu_t *pdu;
140 coap_session_t *session;
141 struct sigaction sa;
142 coap_context_t *ctx;
143
144 if ( argc > 1 && strncmp(argv[1], "-h", 2) == 0 ) {
145 usage( argv[0] );
146 exit( 1 );
147 }
148
149 ctx = coap_new_context(NULL);
150 if (!ctx)
151 return -1;
152
153 session = get_session(ctx, argc > 1 ? argv[1] : "::1");
154
155 if ( !session )
156 return -1;
157
158 id = rand() & INT_MAX;
159
160 memset (&sa, 0, sizeof(sa));
161 sigemptyset(&sa.sa_mask);
162 sa.sa_handler = handle_sigint;
163 sa.sa_flags = 0;
164 sigaction (SIGINT, &sa, NULL);
165 sigaction (SIGTERM, &sa, NULL);
166 /* So we do not exit on a SIGPIPE */
167 sa.sa_handler = SIG_IGN;
168 sigaction (SIGPIPE, &sa, NULL);
169
170 while ( !quit ) {
171
172 if (! (pdu = make_pdu( rand() & 0xfff ) ) )
173 break;
174
175 coap_send(session, pdu);
176
177 tv.tv_sec = 5; tv.tv_usec = 0;
178
179 select( 0, 0, 0, 0, &tv );
180
181 }
182
183 coap_free_context(ctx);
184
185 return 0;
186 }
187