static void
bootstrap_from_name( const char *name, tr_port port, int af )
{
struct addrinfo hints, *info, *infop;
char pp[10];
int rc;
memset(&hints, 0, sizeof(hints));
hints.ai_socktype = SOCK_DGRAM;
hints.ai_family = af;
/* No, just passing p + 1 to gai won't work. */
tr_snprintf(pp, sizeof(pp), "%d", (int)port);
rc = getaddrinfo(name, pp, &hints, &info);
if(rc != 0) {
tr_nerr("DHT", "%s:%s: %s", name, pp, gai_strerror(rc));
return;
}
infop = info;
while(infop) {
dht_ping_node(infop->ai_addr, infop->ai_addrlen);
nap(15);
if(bootstrap_done(session, af))
break;
infop = infop->ai_next;
}
freeaddrinfo(info);
}
int kad_ping( const IP* addr ) {
int rc;
dht_lock();
rc = dht_ping_node( (struct sockaddr *)addr, addr_len( addr ) );
dht_unlock();
return (rc < 0) ? -1 : 0;
}
int
tr_dhtAddNode( tr_session * ss,
const tr_address * address,
tr_port port,
tr_bool bootstrap )
{
int af = address->type == TR_AF_INET ? AF_INET : AF_INET6;
if( !tr_dhtEnabled( ss ) )
return 0;
/* Since we don't want to abuse our bootstrap nodes,
* we don't ping them if the DHT is in a good state. */
if(bootstrap) {
if(tr_dhtStatus(ss, af, NULL) >= TR_DHT_FIREWALLED)
return 0;
}
if( address->type == TR_AF_INET ) {
struct sockaddr_in sin;
memset(&sin, 0, sizeof(sin));
sin.sin_family = AF_INET;
memcpy(&sin.sin_addr, &address->addr.addr4, 4);
sin.sin_port = htons(port);
dht_ping_node((struct sockaddr*)&sin, sizeof(sin));
return 1;
} else if( address->type == TR_AF_INET6 ) {
struct sockaddr_in6 sin6;
memset(&sin6, 0, sizeof(sin6));
sin6.sin6_family = AF_INET6;
memcpy(&sin6.sin6_addr, &address->addr.addr6, 16);
sin6.sin6_port = htons(port);
dht_ping_node((struct sockaddr*)&sin6, sizeof(sin6));
return 1;
}
return 0;
}
int
main(int argc, char *argv[]){
int sfd, fd;
int rc, i;
int opt, quiet = 0, port;
struct sockaddr_in sin;
unsigned char myid[20];
if(argc < 2){
usage();
}
while(1){
int opt_result = 1;
opt = getopt(argc, argv, "qb:");
if(opt < 0){
break;
}
switch(opt){
case 'q': quiet = 1; break;
case 'b':{
char buf[16];
int rc;
rc = inet_pton(AF_INET, optarg, buf);
if(rc == 1){
memcpy(&sin.sin_addr, buf, 4);
break;
}
opt_result = 0;
}
default:
opt_result = 0;
}
if(opt_result == 0){
usage();
}
}
i = optind;
if(argc < i + 1){
usage();
}
port = atoi(argv[i++]);
if(port <= 0 || port >= 0x10000){
usage();
}
while(i < argc){
struct addrinfo hints, *info, *infop;
memset(&hints, 0, sizeof(hints));
hints.ai_socktype = SOCK_DGRAM;
hints.ai_family = AF_INET;
rc = getaddrinfo(argv[i], argv[i + 1], &hints, &info);
if(rc != 0){
fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rc));
exit(1);
}
i++;
if(i >= argc){
usage();
}
infop = info;
while(infop){
memcpy(&bootstrap_nodes[num_bootstrap_nodes],
infop->ai_addr, infop->ai_addrlen);
infop = infop->ai_next;
num_bootstrap_nodes++;
}
freeaddrinfo(info);
i++;
}
if(!quiet){
dht_debug = stdout;
}
fd = open("/dev/urandom", O_RDONLY);
if(fd < 0){
perror("open(random)");
exit(1);
}
rc = read(fd, myid, 20);
if(rc < 0){
perror("read(random)");
exit(EXIT_FAILURE);
}
close(fd);
print_hex(stdout, myid, sizeof(char) * 20);
sfd = socket(AF_INET, SOCK_DGRAM, 0);
if(sfd < -1){
perror("socket(IPv4)");
}
sin.sin_port = htons(port);
rc = bind(sfd, (struct sockaddr*)&sin, sizeof(sin));
if(rc < 0){
perror("bind(IPv6)");
exit(1);
}
rc = dht_init(sfd, 0, myid, NULL);
if(rc < 0){
perror("dht_init");
exit(1);
}
for(i = 0; i < num_bootstrap_nodes; i++){
dht_ping_node((struct sockaddr*)&bootstrap_nodes[i],
sizeof(bootstrap_nodes[i]));
usleep(random() % 100000);
}
close(sfd);
return EXIT_SUCCESS;
}
int
main(int argc, char **argv)
{
int i, rc, fd;
int s = -1, s6 = -1, port;
int have_id = 0;
unsigned char myid[20];
time_t tosleep = 0;
char *id_file = "dht-example.id";
int opt;
int quiet = 0, ipv4 = 1, ipv6 = 1;
struct sockaddr_in sin;
struct sockaddr_in6 sin6;
memset(&sin, 0, sizeof(sin));
sin.sin_family = AF_INET;
memset(&sin6, 0, sizeof(sin6));
sin6.sin6_family = AF_INET6;
while(1) {
opt = getopt(argc, argv, "q46b:i:");
if(opt < 0)
break;
switch(opt) {
case 'q': quiet = 1; break;
case '4': ipv6 = 0; break;
case '6': ipv4 = 0; break;
case 'b': {
char buf[16];
int rc;
rc = inet_pton(AF_INET, optarg, buf);
if(rc == 1) {
memcpy(&sin.sin_addr, buf, 4);
break;
}
rc = inet_pton(AF_INET6, optarg, buf);
if(rc == 1) {
memcpy(&sin6.sin6_addr, buf, 16);
break;
}
goto usage;
}
break;
case 'i':
id_file = optarg;
break;
default:
goto usage;
}
}
/* Ids need to be distributed evenly, so you cannot just use your
bittorrent id. Either generate it randomly, or take the SHA-1 of
something. */
fd = open(id_file, O_RDONLY);
if(fd >= 0) {
rc = read(fd, myid, 20);
if(rc == 20)
have_id = 1;
close(fd);
}
fd = open("/dev/urandom", O_RDONLY);
if(fd < 0) {
perror("open(random)");
exit(1);
}
if(!have_id) {
int ofd;
rc = read(fd, myid, 20);
if(rc < 0) {
perror("read(random)");
exit(1);
}
have_id = 1;
close(fd);
ofd = open(id_file, O_WRONLY | O_CREAT | O_TRUNC, 0666);
if(ofd >= 0) {
rc = write(ofd, myid, 20);
if(rc < 20)
unlink(id_file);
close(ofd);
}
}
{
unsigned seed;
read(fd, &seed, sizeof(seed));
srandom(seed);
}
close(fd);
if(argc < 2)
goto usage;
i = optind;
if(argc < i + 1)
goto usage;
port = atoi(argv[i++]);
if(port <= 0 || port >= 0x10000)
goto usage;
while(i < argc) {
struct addrinfo hints, *info, *infop;
memset(&hints, 0, sizeof(hints));
hints.ai_socktype = SOCK_DGRAM;
if(!ipv6)
hints.ai_family = AF_INET;
else if(!ipv4)
hints.ai_family = AF_INET6;
else
hints.ai_family = 0;
rc = getaddrinfo(argv[i], argv[i + 1], &hints, &info);
if(rc != 0) {
fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rc));
exit(1);
}
i++;
if(i >= argc)
goto usage;
infop = info;
while(infop) {
memcpy(&bootstrap_nodes[num_bootstrap_nodes],
infop->ai_addr, infop->ai_addrlen);
infop = infop->ai_next;
num_bootstrap_nodes++;
}
freeaddrinfo(info);
i++;
}
/* If you set dht_debug to a stream, every action taken by the DHT will
be logged. */
if(!quiet)
dht_debug = stdout;
/* We need an IPv4 and an IPv6 socket, bound to a stable port. Rumour
has it that uTorrent works better when it is the same as your
Bittorrent port. */
if(ipv4) {
s = socket(PF_INET, SOCK_DGRAM, 0);
if(s < 0) {
perror("socket(IPv4)");
}
}
if(ipv6) {
s6 = socket(PF_INET6, SOCK_DGRAM, 0);
if(s6 < 0) {
perror("socket(IPv6)");
}
}
if(s < 0 && s6 < 0) {
fprintf(stderr, "Eek!");
exit(1);
}
if(s >= 0) {
sin.sin_port = htons(port);
rc = bind(s, (struct sockaddr*)&sin, sizeof(sin));
if(rc < 0) {
perror("bind(IPv4)");
exit(1);
}
}
if(s6 >= 0) {
int rc;
int val = 1;
rc = setsockopt(s6, IPPROTO_IPV6, IPV6_V6ONLY,
(char *)&val, sizeof(val));
if(rc < 0) {
perror("setsockopt(IPV6_V6ONLY)");
exit(1);
}
/* BEP-32 mandates that we should bind this socket to one of our
global IPv6 addresses. In this simple example, this only
happens if the user used the -b flag. */
sin6.sin6_port = htons(port);
rc = bind(s6, (struct sockaddr*)&sin6, sizeof(sin6));
if(rc < 0) {
perror("bind(IPv6)");
exit(1);
}
}
/* Init the dht. This sets the socket into non-blocking mode. */
rc = dht_init(s, s6, myid, (unsigned char*)"JC\0\0");
if(rc < 0) {
perror("dht_init");
exit(1);
}
init_signals();
/* For bootstrapping, we need an initial list of nodes. This could be
hard-wired, but can also be obtained from the nodes key of a torrent
file, or from the PORT bittorrent message.
Dht_ping_node is the brutal way of bootstrapping -- it actually
sends a message to the peer. If you're going to bootstrap from
a massive number of nodes (for example because you're restoring from
a dump) and you already know their ids, it's better to use
dht_insert_node. If the ids are incorrect, the DHT will recover. */
for(i = 0; i < num_bootstrap_nodes; i++) {
dht_ping_node((struct sockaddr*)&bootstrap_nodes[i],
sizeof(bootstrap_nodes[i]));
usleep(random() % 100000);
}
while(1) {
struct timeval tv;
fd_set readfds;
tv.tv_sec = tosleep;
tv.tv_usec = random() % 1000000;
FD_ZERO(&readfds);
if(s >= 0)
FD_SET(s, &readfds);
if(s6 >= 0)
FD_SET(s6, &readfds);
rc = select(s > s6 ? s + 1 : s6 + 1, &readfds, NULL, NULL, &tv);
if(rc < 0) {
if(errno != EINTR) {
perror("select");
sleep(1);
}
}
if(exiting)
break;
rc = dht_periodic(rc > 0, &tosleep, callback, NULL);
if(rc < 0) {
if(errno == EINTR) {
continue;
} else {
perror("dht_periodic");
if(rc == EINVAL || rc == EFAULT)
abort();
tosleep = 1;
}
}
/* This is how you trigger a search for a torrent hash. If port
(the second argument) is non-zero, it also performs an announce.
Since peers expire announced data after 30 minutes, it's a good
idea to reannounce every 28 minutes or so. */
if(searching) {
if(s >= 0)
dht_search(hash, 0, AF_INET, callback, NULL);
if(s6 >= 0)
dht_search(hash, 0, AF_INET6, callback, NULL);
searching = 0;
}
/* For debugging, or idle curiosity. */
if(dumping) {
dht_dump_tables(stdout);
dumping = 0;
}
}
{
struct sockaddr_in sin[500];
struct sockaddr_in6 sin6[500];
int num = 500, num6 = 500;
int i;
i = dht_get_nodes(sin, &num, sin6, &num6);
printf("Found %d (%d + %d) good nodes.\n", i, num, num6);
}
dht_uninit(1);
return 0;
usage:
printf("Usage: dht-example [-q] [-4] [-6] [-i filename] [-b address]...\n"
" port [address port]...\n");
exit(1);
}