1 /* tiny -- tiny sender
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 #include <string.h>
10 #include <stdlib.h>
11 #include <stdio.h>
12 #include <ctype.h>
13 #include <limits.h>
14 #include <sys/select.h>
15 #include <sys/types.h>
16 #include <sys/socket.h>
17 #include <netinet/in.h>
18 #include <arpa/inet.h>
19 #include <netdb.h>
20 #include <signal.h>
21
22 #include "coap.h"
23
24 #ifdef __GNUC__
25 #define UNUSED_PARAM __attribute__ ((unused))
26 #else /* not a GCC */
27 #define UNUSED_PARAM
28 #endif /* GCC */
29
30 static coap_tid_t id;
31 static int quit = 0;
32
33 /* SIGINT handler: set quit to 1 for graceful termination */
34 static void
handle_sigint(int signum UNUSED_PARAM)35 handle_sigint(int signum UNUSED_PARAM) {
36 quit = 1;
37 }
38
39 static coap_pdu_t *
make_pdu(unsigned int value)40 make_pdu( unsigned int value ) {
41 coap_pdu_t *pdu;
42 unsigned char enc;
43 static unsigned char buf[20];
44 int len, ls;
45
46 if (!(pdu = coap_pdu_init(0, 0, 0, COAP_DEFAULT_MTU)))
47 return NULL;
48
49 pdu->type = COAP_MESSAGE_NON;
50 pdu->code = COAP_REQUEST_POST;
51 pdu->tid = id++;
52
53 enc = COAP_PSEUDOFP_ENCODE_8_4_DOWN(value,ls);
54
55 len = sprintf((char *)buf, "%c%u", enc, COAP_PSEUDOFP_DECODE_8_4(enc));
56 coap_add_data( pdu, len, buf );
57
58 return pdu;
59 }
60
61 static void
usage(const char * program)62 usage( const char *program ) {
63 const char *p;
64
65 p = strrchr( program, '/' );
66 if ( p )
67 program = ++p;
68
69 fprintf( stderr, "%s -- tiny fake sensor\n"
70 "(c) 2010 Olaf Bergmann <bergmann@tzi.org>\n\n"
71 "usage: %s [group address]\n"
72 "\n\nSends some fake sensor values to specified multicast group\n",
73 program, program );
74 }
75
76 static coap_session_t *
get_session(const char * group)77 get_session(const char *group) {
78 coap_context_t *ctx = coap_new_context(NULL);
79 int s;
80 struct addrinfo hints;
81 struct addrinfo *result, *rp;
82 coap_session_t *session;
83 int hops = 16;
84
85 if (!ctx)
86 return NULL;
87
88 memset(&hints, 0, sizeof(struct addrinfo));
89 hints.ai_family = AF_UNSPEC; /* Allow IPv4 or IPv6 */
90 hints.ai_socktype = SOCK_DGRAM; /* Coap uses UDP */
91 hints.ai_flags = AI_PASSIVE | AI_NUMERICHOST | AI_NUMERICSERV | AI_ALL;
92
93 s = getaddrinfo(group, NULL, &hints, &result);
94 if ( s != 0 ) {
95 fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(s));
96 return NULL;
97 }
98
99 /* iterate through results until success */
100 for (rp = result; rp != NULL; rp = rp->ai_next) {
101 coap_address_t addr;
102 coap_address_init(&addr);
103 addr.size = rp->ai_addrlen;
104 memcpy(&addr.addr, rp->ai_addr, rp->ai_addrlen);
105
106 session = coap_new_client_session(ctx, NULL, &addr, COAP_PROTO_UDP);
107 if (!session)
108 continue;
109
110 if (IN6_IS_ADDR_MULTICAST(&addr.addr.sin6.sin6_addr) ) {
111 /* set socket options for multicast */
112 if ( setsockopt(session->sock.fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS,
113 (char *)&hops, sizeof(hops) ) < 0 )
114 perror("setsockopt: IPV6_MULTICAST_HOPS");
115
116 }
117 freeaddrinfo(result);
118 return session;
119 }
120
121 fprintf(stderr, "no session available for group '%s'\n", group);
122 freeaddrinfo(result);
123 return NULL;
124 }
125
126 int
main(int argc,char ** argv)127 main(int argc, char **argv) {
128 struct timeval tv;
129 coap_pdu_t *pdu;
130 coap_session_t *session;
131 struct sigaction sa;
132
133 if ( argc > 1 && strncmp(argv[1], "-h", 2) == 0 ) {
134 usage( argv[0] );
135 exit( 1 );
136 }
137
138 session = get_session(argc > 1 ? argv[1] : "::1");
139
140 if ( !session )
141 return -1;
142
143 id = rand() & INT_MAX;
144
145 memset (&sa, 0, sizeof(sa));
146 sigemptyset(&sa.sa_mask);
147 sa.sa_handler = handle_sigint;
148 sa.sa_flags = 0;
149 sigaction (SIGINT, &sa, NULL);
150 sigaction (SIGTERM, &sa, NULL);
151 /* So we do not exit on a SIGPIPE */
152 sa.sa_handler = SIG_IGN;
153 sigaction (SIGPIPE, &sa, NULL);
154
155 while ( !quit ) {
156
157 if (! (pdu = make_pdu( rand() & 0xfff ) ) )
158 break;
159
160 coap_send(session, pdu);
161
162 tv.tv_sec = 5; tv.tv_usec = 0;
163
164 select( 0, 0, 0, 0, &tv );
165
166 }
167
168 coap_free_context( session->context );
169
170 return 0;
171 }
172