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
21 #include "../coap.h"
22
23 static coap_tid_t id;
24
25 coap_pdu_t *
make_pdu(unsigned int value)26 make_pdu( unsigned int value ) {
27 coap_pdu_t *pdu;
28 unsigned char enc;
29 static unsigned char buf[20];
30 int len, ls;
31
32 if ( ! ( pdu = coap_new_pdu() ) )
33 return NULL;
34
35 pdu->hdr->type = COAP_MESSAGE_NON;
36 pdu->hdr->code = COAP_REQUEST_POST;
37 pdu->hdr->id = htons(id++);
38
39 enc = COAP_PSEUDOFP_ENCODE_8_4_DOWN(value,ls);
40 coap_add_data( pdu, 1, &enc);
41
42 len = sprintf((char *)buf, "%u", COAP_PSEUDOFP_DECODE_8_4(enc));
43 if ( len > 0 ) {
44 coap_add_data( pdu, len, buf );
45 }
46
47 return pdu;
48 }
49
50 void
usage(const char * program)51 usage( const char *program ) {
52 const char *p;
53
54 p = strrchr( program, '/' );
55 if ( p )
56 program = ++p;
57
58 fprintf( stderr, "%s -- tiny fake sensor\n"
59 "(c) 2010 Olaf Bergmann <bergmann@tzi.org>\n\n"
60 "usage: %s [group address]\n"
61 "\n\nSends some fake sensor values to specified multicast group\n",
62 program, program );
63 }
64
65 coap_context_t *
get_context(const char * node,const char * port)66 get_context(const char *node, const char *port) {
67 coap_context_t *ctx = NULL;
68 int s;
69 struct addrinfo hints;
70 struct addrinfo *result, *rp;
71
72 memset(&hints, 0, sizeof(struct addrinfo));
73 hints.ai_family = AF_UNSPEC; /* Allow IPv4 or IPv6 */
74 hints.ai_socktype = SOCK_DGRAM; /* Coap uses UDP */
75 hints.ai_flags = AI_PASSIVE | AI_NUMERICHOST | AI_NUMERICSERV | AI_ALL;
76
77 s = getaddrinfo(node, port, &hints, &result);
78 if ( s != 0 ) {
79 fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(s));
80 return NULL;
81 }
82
83 /* iterate through results until success */
84 for (rp = result; rp != NULL; rp = rp->ai_next) {
85 ctx = coap_new_context(rp->ai_addr, rp->ai_addrlen);
86 if (ctx) {
87 /* TODO: output address:port for successful binding */
88 goto finish;
89 }
90 }
91
92 fprintf(stderr, "no context available for interface '%s'\n", node);
93
94 finish:
95 freeaddrinfo(result);
96 return ctx;
97 }
98
99 int
main(int argc,char ** argv)100 main(int argc, char **argv) {
101 coap_context_t *ctx;
102 struct timeval tv;
103 coap_pdu_t *pdu;
104 struct sockaddr_in6 dst;
105 int hops = 16;
106
107 if ( argc > 1 && strncmp(argv[1], "-h", 2) == 0 ) {
108 usage( argv[0] );
109 exit( 1 );
110 }
111
112 ctx = get_context("::", NULL);
113 if ( !ctx )
114 return -1;
115
116 id = rand() & INT_MAX;
117
118 memset(&dst, 0, sizeof(struct sockaddr_in6 ));
119 dst.sin6_family = AF_INET6;
120 inet_pton( AF_INET6, argc > 1 ? argv[1] : "::1", &dst.sin6_addr );
121 dst.sin6_port = htons( COAP_DEFAULT_PORT );
122
123 if ( IN6_IS_ADDR_MULTICAST(&dst.sin6_addr) ) {
124 /* set socket options for multicast */
125
126 if ( setsockopt( ctx->sockfd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS,
127 (char *)&hops, sizeof(hops) ) < 0 )
128 perror("setsockopt: IPV6_MULTICAST_HOPS");
129
130 }
131
132 while ( 1 ) {
133
134 if (! (pdu = make_pdu( rand() & 0xfff ) ) )
135 return -1;
136
137 coap_send( ctx, (struct sockaddr *)&dst, sizeof(dst), pdu );
138 coap_delete_pdu(pdu);
139
140 tv.tv_sec = 5; tv.tv_usec = 0;
141
142 select( 0, 0, 0, 0, &tv );
143
144 }
145
146 coap_free_context( ctx );
147
148 return 0;
149 }
150
