int main(int argc, char *argv[])
{
int r = 0;
char err[128];
struct mdns_ctx *ctx;
signal(SIGINT, sighandler);
signal(SIGTERM, sighandler);
if ((r = mdns_init(&ctx, MDNS_ADDR_IPV4, MDNS_PORT)) < 0)
goto err;
// test with `ping mdnshost.local`
mdns_announce(ctx, "mdnshost.local", RR_A, callback, ctx);
if ((r = mdns_serve(ctx, stop, NULL)) < 0)
goto err;
err:
if (r < 0) {
mdns_strerror(r, err, sizeof(err));
fprintf(stderr, "fatal: %s\n", err);
}
mdns_destroy(ctx);
return (0);
}
int
mdns_init(struct mdns_ctx **p_ctx, const char *addr, unsigned short port)
{
const uint32_t on_off = 1;
const uint32_t ttl = 255;
const uint8_t loop = 1;
#ifdef _WIN32
union {
struct sockaddr_storage ss;
struct sockaddr_in sin;
struct sockaddr_in6 sin6;
} dumb;
#endif /* _WIN32 */
struct mdns_ctx *ctx;
if (p_ctx == NULL)
return (MDNS_STDERR);
*p_ctx = NULL;
ctx = malloc(sizeof(struct mdns_ctx));
if (ctx == NULL)
return (MDNS_STDERR);
ctx->services = NULL;
ctx->sock = INVALID_SOCKET;
errno = os_init("2.2");
if (errno != 0)
return mdns_destroy(ctx), (MDNS_NETERR);
if (mdns_resolve(&ctx->addr, addr, port) < 0)
return mdns_destroy(ctx), (MDNS_LKPERR);
if ((ctx->sock = socket(ss_family(&ctx->addr), SOCK_DGRAM, IPPROTO_UDP)) == INVALID_SOCKET)
return mdns_destroy(ctx), (MDNS_NETERR);
if (setsockopt(ctx->sock, SOL_SOCKET, SO_REUSEADDR, (const void *) &on_off, sizeof(on_off)) < 0)
return mdns_destroy(ctx), (MDNS_NETERR);
#ifdef _WIN32
/* bind the receiver on any local address */
memset(&dumb, 0, sizeof(dumb));
dumb.ss.ss_family = ss_family(&ctx->addr);
if (dumb.ss.ss_family == AF_INET) {
dumb.sin.sin_port = htons(port);
dumb.sin.sin_addr.s_addr = INADDR_ANY;
} else {
dumb.sin6.sin6_port = htons(port);
dumb.sin6.sin6_addr = in6addr_any;
}
if (bind(ctx->sock, (const struct sockaddr *) &dumb, ss_len(&dumb.ss)) < 0)
return mdns_destroy(ctx), (MDNS_NETERR);
#else /* _WIN32 */
if (bind(ctx->sock, (const struct sockaddr *) &ctx->addr, ss_len(&ctx->addr)) < 0)
return mdns_destroy(ctx), (MDNS_NETERR);
#endif /* _WIN32 */
if (os_mcast_join(ctx->sock, &ctx->addr) < 0)
return mdns_destroy(ctx), (MDNS_NETERR);
if (setsockopt(ctx->sock, ss_level(&ctx->addr), ss_family(&ctx->addr)==AF_INET ? IP_MULTICAST_TTL : IPV6_MULTICAST_HOPS, (const void *) &ttl, sizeof(ttl)) < 0)
return mdns_destroy(ctx), (MDNS_NETERR);
if (setsockopt(ctx->sock, ss_level(&ctx->addr), IP_MULTICAST_LOOP, (const void *) &loop, sizeof(loop)) < 0)
return mdns_destroy(ctx), (MDNS_NETERR);
*p_ctx = ctx;
return (0);
}
