diff options
Diffstat (limited to 'common/hostchooser.py')
| -rw-r--r-- | common/hostchooser.py | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/common/hostchooser.py b/common/hostchooser.py new file mode 100644 index 0000000..3243e06 --- /dev/null +++ b/common/hostchooser.py @@ -0,0 +1,192 @@ +from socket import * +import time, select, sys +from errno import ETIMEDOUT + +UDP_PORT = 8056 +PING_MESSAGE = "pclient-game-ping" +PONG_MESSAGE = "server-game-pong" + + +def serverside_ping(only_port=None): + port = only_port or UDP_PORT + s = socket(AF_INET, SOCK_DGRAM) + try: + s.bind(('', port)) + s.setsockopt(SOL_SOCKET, SO_BROADCAST, 1) + return s + except error, e: + if only_port is None: + s = socket(AF_INET, SOCK_DGRAM) + s.bind(('', INADDR_ANY)) + return s + else: + return None + +def answer_ping(s, descr, addr, extra='', httpport=''): + try: + data, source = s.recvfrom(100) + except error, e: + print >> sys.stderr, 'ping error:', str(e) + return + if data == PING_MESSAGE: + print >> sys.stderr, "ping by", source + answer = '%s:%s:%s:%s:%s:%s' % (PONG_MESSAGE, descr, + addr[0], addr[1], extra, httpport) + s.sendto(answer, source) + else: + print >> sys.stderr, \ + "unexpected data on UDP port %d by" % UDP_PORT, source + + +def pick(hostlist, delay=1): + s = socket(AF_INET, SOCK_DGRAM) + s.setsockopt(SOL_SOCKET, SO_BROADCAST, 1) + for host in hostlist: + print >> sys.stderr, "* Looking for a server on %s... " % host + try: + s.sendto(PING_MESSAGE, (host, UDP_PORT)) + except error, e: + print >> sys.stderr, 'send:', str(e) + continue + while 1: + iwtd, owtd, ewtd = select.select([s], [], [], delay) + if not iwtd: + break + try: + data, answer_from = s.recvfrom(200) + except error, e: + if e.args[0] != ETIMEDOUT: + print >> sys.stderr, 'recv:', str(e) + continue + break + data = data.split(':') + if len(data) >= 4 and data[0] == PONG_MESSAGE: + hostname = data[2] or answer_from[0] + try: + port = int(data[3]) + except ValueError: + pass + else: + result = (hostname, port) + print >> sys.stderr, "* Picking %r at" % data[1], result + return result + print >> sys.stderr, "got an unexpected answer", data, "from", answer_from + print >> sys.stderr, "no server found." + raise SystemExit + +def find_servers(hostlist=[('127.0.0.1', None), ('<broadcast>', None)], + tries=2, delay=0.5, verbose=1, port_needed=1): + import gamesrv + if verbose: + print >> sys.stderr, 'Looking for servers in the following list:' + for host, udpport in hostlist: + print >> sys.stderr, ' %s, UDP port %s' % ( + host, udpport or ("%s (default)" % UDP_PORT)) + events = {} + replies = [] + s = socket(AF_INET, SOCK_DGRAM) + s.setsockopt(SOL_SOCKET, SO_BROADCAST, 1) + for trynum in range(tries): + for host, udpport in hostlist: + try: + ipaddr = host + if host != '<broadcast>': + try: + ipaddr = gethostbyname(host) + except error, e: + print >> sys.stderr, 'gethostbyname:', str(e) + s.sendto(PING_MESSAGE, (ipaddr, udpport or UDP_PORT)) + hostsend, hostrecv = events.setdefault(ipaddr, ([], [])) + hostsend.append(time.time()) + except error, e: + print >> sys.stderr, 'send:', str(e) + continue + endtime = time.time() + delay + while gamesrv.recursiveloop(endtime, [s]): + try: + data, answer_from = s.recvfrom(200) + except error, e: + if e.args[0] != ETIMEDOUT: + print >> sys.stderr, 'recv:', str(e) + continue + break + try: + ipaddr = gethostbyname(answer_from[0]) + except error: + ipaddr = answer_from[0] + else: + hostsend, hostrecv = events.setdefault(ipaddr, ([], [])) + hostrecv.append(time.time()) + data = data.split(':') + if len(data) >= 4 and data[0] == PONG_MESSAGE: + try: + port = int(data[3]) + except ValueError: + if port_needed: + continue + port = '' + if data[2]: + hostname = data[2] + realhostname = [hostname] + else: + hostname = answer_from[0] + realhostname = lazy_gethostbyaddr(hostname) + server = ':'.join(data[1:2]+data[4:]) + replies.append((hostname, realhostname, port, server, ipaddr)) + else: + print >> sys.stderr, "got an unexpected answer from", answer_from + servers = {} + aliases = {} + timeout = time.time() + 2.0 # wait for gethostbyaddr() for 2 seconds + while replies: + i = 0 + now = time.time() + while i < len(replies): + hostname, realhostname, port, server, ipaddr = replies[i] + if realhostname: + hostname = realhostname[0] # got an answer + elif now < timeout: + i += 1 # must wait some more time + continue + result = (hostname, port) + servers[result] = server + aliases[hostname] = ipaddr + del replies[i] + if replies: + time.sleep(0.08) # time for gethostbyaddr() to finish + if verbose: + print >> sys.stderr, "%d answer(s):" % len(servers), servers.keys() + for host, port in servers.keys(): + ping = None + ipaddr = aliases[host] + if ipaddr in events: + hostsend, hostrecv = events[ipaddr] + if len(hostsend) == len(hostrecv) == tries: + ping = min([t2-t1 for t1, t2 in zip(hostsend, hostrecv)]) + servers[host, port] = (servers[host, port], ping) + sys.setcheckinterval(4096) + return servers + +# ____________________________________________________________ + +HOSTNAMECACHE = {} + +def _lazygetter(hostname, resultlst): + try: + try: + hostname = gethostbyaddr(hostname)[0] + if hostname == 'localhost': + from msgstruct import HOSTNAME as hostname + except error: + pass + finally: + resultlst.append(hostname) + +def lazy_gethostbyaddr(hostname): + try: + return HOSTNAMECACHE[hostname] + except KeyError: + resultlst = HOSTNAMECACHE[hostname] = [] + import thread + thread.start_new_thread(_lazygetter, (hostname, resultlst)) + return resultlst |