2 #include <sys/socket.h>
3 #include <netinet/in.h>
17 void txt_printer (xht h, const char *key, void *val, void *arg)
19 printf (" %s=%s\n", key, (char *) val);
24 int ans(mdnsda a, void *arg)
28 struct in_addr ip_addr;
29 if(a->ttl == 0) now = 0;
30 else now = a->ttl - time(0);
34 ip_addr.s_addr = a->ip;
35 printf("A %s for %d seconds to ip %s\n",a->name,now,inet_ntoa(ip_addr));
38 printf("PTR %s for %d seconds to %s\n",a->name,now,a->rdname);
41 printf("SRV %s for %d seconds to %s:%d\n",a->name,now,a->rdname,a->srv.port);
44 printf("TXT %s for %d seconds:\n",a->name,now);
45 h = txt2sd (a->rdata, a->rdlen);
46 xht_walk (h, txt_printer, NULL);
50 printf("%d %s for %d seconds with %d data\n",a->type,a->name,now,a->rdlen);
56 // create multicast 224.0.0.251:5353 socket
59 int s, flag = 1, ittl = 255;
60 struct sockaddr_in in;
64 bzero(&in, sizeof(in));
65 in.sin_family = AF_INET;
66 in.sin_port = htons(5353);
67 in.sin_addr.s_addr = 0;
69 if((s = socket(AF_INET,SOCK_DGRAM,0)) < 0) return 0;
71 setsockopt(s, SOL_SOCKET, SO_REUSEPORT, (char*)&flag, sizeof(flag));
73 setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (char*)&flag, sizeof(flag));
74 if(bind(s,(struct sockaddr*)&in,sizeof(in))) { close(s); return 0; }
76 mc.imr_multiaddr.s_addr = inet_addr("224.0.0.251");
77 mc.imr_interface.s_addr = htonl(INADDR_ANY);
78 setsockopt(s, IPPROTO_IP, IP_ADD_MEMBERSHIP, &mc, sizeof(mc));
79 setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl));
80 setsockopt(s, IPPROTO_IP, IP_MULTICAST_TTL, &ittl, sizeof(ittl));
82 flag = fcntl(s, F_GETFL, 0);
84 fcntl(s, F_SETFL, flag);
89 int main(int argc, char *argv[])
94 unsigned short int port;
96 int bsize, ssize = sizeof(struct sockaddr_in);
97 unsigned char buf[MAX_PACKET_LEN];
98 struct sockaddr_in from, to;
102 if(argc != 3) { printf("usage: mquery 12 _http._tcp.local.\n"); return -1; }
104 d = mdnsd_new(1,1000);
105 if((s = msock()) == 0) { printf("can't create socket: %s\n",strerror(errno)); return 1; }
107 mdnsd_query(d,argv[2],atoi(argv[1]),ans,0);
114 select(s+1,&fds,0,0,tv);
118 while((bsize = recvfrom(s,buf,MAX_PACKET_LEN,0,(struct sockaddr*)&from,&ssize)) > 0)
120 bzero(&m,sizeof(struct message));
121 message_parse(&m,buf);
122 mdnsd_in(d,&m,(unsigned long int)from.sin_addr.s_addr,from.sin_port);
124 if(bsize < 0 && errno != EAGAIN) { printf("can't read from socket %d: %s\n",errno,strerror(errno)); return 1; }
126 while(mdnsd_out(d,&m,&ip,&port))
128 bzero(&to, sizeof(to));
129 to.sin_family = AF_INET;
131 to.sin_addr.s_addr = ip;
132 if(sendto(s,message_packet(&m),message_packet_len(&m),0,(struct sockaddr *)&to,sizeof(struct sockaddr_in)) != message_packet_len(&m)) { printf("can't write to socket: %s\n",strerror(errno)); return 1; }