├── README.rst ├── rollproxy.py └── COPYING /README.rst: -------------------------------------------------------------------------------- 1 | ********* 2 | RollProxy 3 | ********* 4 | 5 | RollProxy is a mining proxy for Bitcoin and other cryptocurrencies that support 6 | the getwork protocol. It can take advantage of the X-Roll-NTime extension to 7 | minimize the number of getwork requests sent to the work provider. By keeping 8 | more requests local, it minimizes latency, while drastically reducing the load 9 | on mining pools. 10 | 11 | Features 12 | ======== 13 | 14 | - Full support for persistent HTTP connections 15 | - Long polling support 16 | - Mining statistics available via web interface 17 | - Basic failover mechanism 18 | - Ability to connect through an additional proxy server 19 | 20 | Requirements 21 | ============ 22 | 23 | - Python 2.6+ or 3+ 24 | - argparse (part of the standard library as of Python 2.7 and 3.2) 25 | - urrlib3 26 | 27 | Quick start 28 | =========== 29 | 30 | First make sure argparse and urllib3 are installed:: 31 | 32 | # pip install argparse urllib3 33 | 34 | If (and only if) you are going to use Python 3 or later, issue:: 35 | 36 | $ 2to3 -w rollproxy.py 37 | 38 | Start the proxy specifying the address and credentials for one or more mining 39 | servers:: 40 | 41 | $ python rollproxy.py http://username:password@host:port/ 42 | 43 | The proxy will listen on port 8345 by default. A web interface is also made 44 | available on the same port. For a detailed list of supported options, run:: 45 | 46 | $ python rollproxy.py --help 47 | 48 | Miners connecting to the proxy do not need to authenticate, but if they supply 49 | a username RollProxy will then be able to generate per-worker statistics. 50 | 51 | License 52 | ======= 53 | 54 | Copyright 2012 pooler 55 | 56 | This program is free software: you can redistribute it and/or modify 57 | it under the terms of the GNU Affero General Public License as 58 | published by the Free Software Foundation, either version 3 of the 59 | License, or (at your option) any later version. 60 | 61 | You should have received a copy of the GNU Affero General Public License 62 | along with this program. If not, see . 63 | -------------------------------------------------------------------------------- /rollproxy.py: -------------------------------------------------------------------------------- 1 | #!/usr/bin/python 2 | 3 | __version__ = '0.5.4' 4 | 5 | import __future__ 6 | import sys 7 | import argparse 8 | import logging 9 | import SocketServer 10 | import BaseHTTPServer 11 | import threading 12 | import time 13 | import urlparse 14 | import urllib3 15 | import binascii 16 | import base64 17 | import re 18 | import json 19 | import math 20 | 21 | 22 | class Pool: 23 | 24 | timeout = 10 25 | lp_timeout = None 26 | default_expire = 60 27 | 28 | def __init__(self, url, maxsize, proxy=None): 29 | self.url = url 30 | self.maxsize = maxsize 31 | self.proxy = proxy 32 | if url.find('://') < 0: 33 | url = 'http://' + url 34 | p = urlparse.urlsplit(url) 35 | i = p.netloc.rfind('@') 36 | self.host = p.netloc[i + 1:] 37 | if i >= 0: 38 | self.auth = ('Basic ' + 39 | base64.b64encode(p.netloc[:i].encode('U8')).decode()) 40 | else: 41 | self.auth = None 42 | self.path = urlparse.urlunsplit(('', '', p.path or '/', p.query, '')) 43 | self.fullpath = 'http://' + self.host + self.path 44 | if proxy: 45 | self.path = self.fullpath 46 | self.pool = urllib3.HTTPConnectionPool(proxy if proxy else self.host, 47 | maxsize=maxsize, block=True) 48 | self.lp_header = None 49 | self.lp_pool = self.pool 50 | self.lp_host = self.host 51 | self.lp_path = self.path 52 | self.expire = 0 53 | 54 | def request(self, method, body, headers, lp=False): 55 | headers['host'] = self.lp_host if lp else self.host 56 | if self.auth: 57 | headers['authorization'] = self.auth 58 | elif 'authorization' in headers: 59 | del headers['authorization'] 60 | pool = self.lp_pool if lp else self.pool 61 | r = pool.urlopen(method, self.lp_path if lp else self.path, 62 | body, headers, assert_same_host=False, 63 | timeout=self.lp_timeout if lp else self.timeout) 64 | for h in ('content-encoding', 'transfer-encoding'): 65 | if h in r.headers: 66 | del r.headers[h] 67 | if ('x-long-polling' in r.headers and 68 | self.lp_header != r.headers['x-long-polling']): 69 | self.lp_header = r.headers['x-long-polling'] 70 | p = urlparse.urlsplit(self.lp_header) 71 | self.lp_host = p.netloc or self.host 72 | if self.proxy: 73 | self.lp_path = urlparse.urljoin(self.fullpath, self.lp_header) 74 | else: 75 | self.lp_path = urlparse.urlunsplit(('', '', p.path or '/', 76 | p.query, '')) 77 | if self.lp_host == self.host: 78 | self.lp_pool = self.pool 79 | else: 80 | self.lp_pool = urllib3.HTTPConnectionPool(p.netloc, 81 | maxsize=self.maxsize, block=True) 82 | return r 83 | 84 | def __str__(self): 85 | return self.fullpath 86 | 87 | 88 | class Work: 89 | 90 | timeout = 10 91 | 92 | def __init__(self): 93 | self.lock = threading.Lock() 94 | self.time = 0 95 | self.headers = None 96 | self.data = None 97 | self.rolls_left = 0 98 | 99 | def roll_ntime(self): 100 | ntime = int(self.data['result']['data'][136:144], 16) + 1 101 | self.data['result']['data'] = (self.data['result']['data'][:136] + 102 | '%08x' % ntime + 103 | self.data['result']['data'][144:]) 104 | 105 | def is_rollable(self): 106 | return self.rolls_left > 0 and time.time() - self.time < self.timeout 107 | 108 | 109 | pools = [] 110 | pool_index = 0 111 | work = Work() 112 | lps = [] 113 | lps_lock = threading.Lock() 114 | workbases = {} 115 | workbases_lock = threading.Lock() 116 | workers = {} 117 | workers_lock = threading.Lock() 118 | solutions = [] 119 | rejections = [] 120 | stats = {'start_time': time.time(), 121 | 'local_gets': 0, 'upstream_gets': 0, 'solutions': 0, 'accepted': 0} 122 | stats_lock = threading.Lock() 123 | 124 | 125 | class RollProxyHandler(BaseHTTPServer.BaseHTTPRequestHandler): 126 | 127 | getwork_path = '/' 128 | getwork_lp_path = '/LP' 129 | force_rolls = False 130 | rate_time = 900 131 | sharelog = None 132 | private = False 133 | 134 | def handle_one_request(self): 135 | try: 136 | BaseHTTPServer.BaseHTTPRequestHandler.handle_one_request(self) 137 | except: 138 | logging.error(sys.exc_info()[1]) 139 | 140 | def finish(self): 141 | try: 142 | BaseHTTPServer.BaseHTTPRequestHandler.finish(self) 143 | except: 144 | pass 145 | 146 | def log_message(self, format, *args): 147 | pass 148 | 149 | def log_error(self, format, *args): 150 | logging.error('%s - %s' % (self.requestline, format), *args) 151 | 152 | def send_response_only(self, code, message=None): 153 | if message is None: 154 | if code in self.responses: 155 | message = self.responses[code][0] 156 | else: 157 | message = '' 158 | if self.request_version != 'HTTP/0.9': 159 | self.wfile.write(('%s %d %s\r\n' % 160 | (self.protocol_version, 161 | code, message)).encode('latin1')) 162 | 163 | def respond(self, code, headers, body): 164 | self.send_response_only(code) 165 | for k, v in headers.iteritems(): 166 | self.send_header(k, v) 167 | self.end_headers() 168 | self.wfile.write(body) 169 | 170 | def do_POST(self): 171 | global pool_index 172 | if self.path not in (self.getwork_path, self.getwork_lp_path): 173 | self.send_error(404) 174 | return 175 | headers = dict((k.lower(), v) for k, v in self.headers.items()) 176 | try: 177 | length = int(headers['content-length']) 178 | body = self.rfile.read(length).decode() 179 | data = json.loads(body) 180 | except: 181 | body = None 182 | is_get = not body or (data['method'] == 'getwork' and 183 | len(data['params']) == 0) 184 | is_lp = self.path == self.getwork_lp_path 185 | username = '-' 186 | if 'authorization' in headers: 187 | m = re.match('Basic (.+)', headers['authorization']) 188 | if m: 189 | auth = base64.b64decode(m.group(1).encode()).decode('U8') 190 | username = auth.split(':')[0] 191 | with workers_lock: 192 | if username not in workers: 193 | workers[username] = {'solutions': 0, 'accepted': 0, 194 | 'first_time': time.time()} 195 | workers[username]['last_time'] = time.time() 196 | if is_get: 197 | with stats_lock: 198 | stats['local_gets'] += 1 199 | else: 200 | solution = data['params'][0] 201 | try: 202 | base = workbases[solution[:136]] 203 | except: 204 | logging.error('Unknown work is being submitted') 205 | base = {'pool': pools[pool_index], 'value': 0} 206 | if is_lp: 207 | lps_lock.acquire() 208 | for lp in lps: 209 | if lp.rolls_left > 0: 210 | lp.rolls_left -= 1 211 | lps_lock.release() 212 | lp.lock.acquire() 213 | if not lp.data: 214 | lp.lock.release() 215 | is_lp = False 216 | break 217 | lp.roll_ntime() 218 | body = json.dumps(lp.data) 219 | lp.lock.release() 220 | self.respond(200, lp.headers, body.encode()) 221 | return 222 | if is_get and not is_lp: 223 | work.lock.acquire() 224 | if work.is_rollable(): 225 | work.roll_ntime() 226 | work.rolls_left -= 1 227 | body = json.dumps(work.data) 228 | work.lock.release() 229 | self.respond(200, work.headers, body.encode()) 230 | return 231 | if is_lp: 232 | lps[:] = (w for w in lps if (not w.time or 233 | time.time() - w.time < 60)) 234 | lp = Work() 235 | lp.lock.acquire() 236 | lp.rolls_left = pools[pool_index].expire 237 | lps.insert(0, lp) 238 | lps_lock.release() 239 | try: 240 | if 'x-mining-extensions' in headers: 241 | t = headers['x-mining-extensions'].split(' ') 242 | if 'rollntime' not in t: 243 | t.append('rollntime') 244 | if 'noncerange' in t: 245 | t.remove('noncerange') 246 | headers['x-mining-extensions'] = ' '.join(t) 247 | else: 248 | headers['x-mining-extensions'] = 'rollntime' 249 | while True: 250 | try: 251 | if is_get: 252 | pool = pools[pool_index] 253 | else: 254 | pool = base['pool'] 255 | if is_get: 256 | with stats_lock: 257 | stats['upstream_gets'] += 1 258 | r = pool.request(self.command, body, headers, is_lp) 259 | if r.status != 200: 260 | logging.error('%d %s', r.status, r.reason) 261 | data = json.loads(r.data.decode()) 262 | if data['error']: 263 | logging.error(data['error']['message']) 264 | if data['error'] == None or not is_get or len(pools) == 1: 265 | break 266 | except urllib3.exceptions.TimeoutError: 267 | if is_lp: 268 | continue 269 | logging.error('Upstream request timed out') 270 | except: 271 | logging.error(sys.exc_info()[1]) 272 | if not is_get or len(pools) == 1: 273 | self.send_error(502) 274 | return 275 | if len(pools) > 1: 276 | pool_index = (pool_index + 1) % len(pools) 277 | logging.warning('Switching to %s', pools[pool_index]) 278 | time.sleep(1) 279 | if r.status != 200 or data['error']: 280 | body = r.data 281 | else: 282 | body = json.dumps(data).encode() 283 | r.headers['content-length'] = str(len(body)) 284 | if 'x-long-polling' in r.headers: 285 | r.headers['x-long-polling'] = self.getwork_lp_path 286 | if is_get: 287 | expire = 0 288 | if ('x-roll-ntime' in r.headers and 289 | r.headers['x-roll-ntime'] not in ('', 'N')): 290 | m = re.match('expire=(\d+)', r.headers['x-roll-ntime']) 291 | if m: 292 | expire = int(m.group(1)) 293 | else: 294 | expire = Pool.default_expire 295 | del r.headers['x-roll-ntime'] 296 | elif self.force_rolls: 297 | expire = Pool.default_expire 298 | pool.expire = expire 299 | if is_lp: 300 | logging.info('Long polling pushed new work') 301 | work.rolls_left = 0 302 | if expire > 0: 303 | if is_lp: 304 | lp.headers = r.headers 305 | lp.data = data 306 | else: 307 | logging.info('New work fetched') 308 | work.time = time.time() 309 | work.headers = r.headers 310 | work.data = data 311 | work.rolls_left = expire 312 | else: 313 | logging.warning('Work cannot be reused') 314 | id = data['result']['data'][:136] 315 | target = data['result']['target'].encode() 316 | target = binascii.hexlify(binascii.unhexlify(target)[::-1]) 317 | value = 2 ** 256 // (int(target, 16) + 1) 318 | base = {'time': time.time(), 'pool': pool, 'value': value} 319 | with workbases_lock: 320 | if not is_lp: 321 | tmin = time.time() - 600 322 | for k, v in workbases.items(): 323 | if v['time'] < tmin: 324 | del workbases[k] 325 | workbases[id] = base 326 | else: 327 | sol = {'time': time.time(), 'result': data['result'], 328 | 'address': self.address_string(), 329 | 'username': username, 'value': base['value'], 330 | 'pool': base['pool']} 331 | result = str(data['result']) 332 | if 'x-reject-reason' in r.headers: 333 | result += ' (%s)' % r.headers['x-reject-reason'] 334 | sol['reason'] = r.headers['x-reject-reason'] 335 | logging.info('Proof of work result: %s', result) 336 | with stats_lock: 337 | stats['solutions'] += 1 338 | if data['result']: 339 | stats['accepted'] += 1 340 | if self.sharelog: 341 | self.sharelog.write( 342 | '%d,%s,%s,%s,%s,%.8f,%s,%s\n' % 343 | (sol['time'], sol['address'], 344 | sol['username'], sol['result'], 345 | sol['reason'] if 'reason' in sol else '', 346 | sol['value'] * 0xffff * 2 ** -48, 347 | sol['pool'], solution)) 348 | with workers_lock: 349 | if solutions and (time.time() - solutions[0]['time'] > 350 | 2 * self.rate_time): 351 | tmin = time.time() - self.rate_time 352 | solutions[:] = (s for s in solutions if 353 | s['time'] > tmin) 354 | solutions.append(sol) 355 | if not data['result']: 356 | rejections.append(sol) 357 | workers[username]['solutions'] += 1 358 | if data['result']: 359 | workers[username]['accepted'] += 1 360 | self.respond(r.status, r.headers, body) 361 | finally: 362 | if is_get: 363 | if is_lp: 364 | lp.time = time.time() 365 | lp.rolls_left = 0 366 | lp.lock.release() 367 | else: 368 | work.lock.release() 369 | 370 | def do_GET(self): 371 | if self.path == self.getwork_lp_path: 372 | self.do_POST() 373 | return 374 | if self.path != '/': 375 | self.send_error(404) 376 | return 377 | if self.private and self.client_address[0] != '127.0.0.1': 378 | self.send_error(403) 379 | return 380 | now = time.time() 381 | body = 'RollProxy' 382 | body += '

RollProxy %s

' % __version__ 383 | body += '

Upstream server: %s

' % pools[pool_index] 384 | uptime = now - stats['start_time'] 385 | body += '

Uptime: %.3f days

' % (uptime / 86400.) 386 | ratio = float(stats['local_gets']) / max(1, stats['upstream_gets']) 387 | body += ('

Getwork requests: %d local, %d upstream,' 388 | ' %.1f:1 ratio

' % 389 | (stats['local_gets'], stats['upstream_gets'], ratio)) 390 | rejected = stats['solutions'] - stats['accepted'] 391 | eff = 100. * stats['accepted'] / max(1, stats['solutions']) 392 | body += ('

Submissions: %d total, %d rejected,' 393 | ' %.2f%% efficiency

' % 394 | (stats['solutions'], rejected, eff)) 395 | with workers_lock: 396 | rate = (sum(s['value'] for s in solutions 397 | if now - s['time'] < self.rate_time) / 398 | min(uptime, self.rate_time)) 399 | rate = self.format_rate(rate, len(solutions)) 400 | body += '

Current rate estimate: %s

' % rate 401 | body += '

Most Recent Submissions

' 402 | body += '' 403 | body += '' 404 | for s in solutions[:-9:-1]: 405 | t = time.strftime('%Y-%m-%d %H:%M:%S', 406 | time.localtime(s['time'])) 407 | r = str(s['result']) 408 | if 'reason' in s: 409 | r += ' (%s)' % s['reason'] 410 | d = s['value'] * 0xffff * 2 ** -48 411 | body += ('' 412 | '' % 413 | (t, r, s['username'], s['address'], d, s['pool'])) 414 | body += '
TimeResultWorkerAddressDifficultyServer
%s%s%s%s%.8f%s
' 415 | 416 | body += '

Most Recent Rejections

' 417 | body += '' 418 | body += '' 419 | for s in rejections[:-9:-1]: 420 | t = time.strftime('%Y-%m-%d %H:%M:%S', 421 | time.localtime(s['time'])) 422 | r = s['reason'] if 'reason' in s else '-' 423 | d = s['value'] * 0xffff * 2 ** -48 424 | body += ('' 425 | '' % 426 | (t, r, s['username'], s['address'], d, s['pool'])) 427 | body += '
TimeReasonWorkerAddressDifficultyServer
%s%s%s%s%.8f%s
' 428 | 429 | for k in workers.iterkeys(): 430 | workers[k]['points'] = 0 431 | workers[k]['hashes'] = 0 432 | for s in solutions: 433 | if now - s['time'] < self.rate_time: 434 | workers[s['username']]['points'] += 1 435 | workers[s['username']]['hashes'] += s['value'] 436 | body += '

Workers

' 437 | body += '' 438 | body += '' 439 | body += '' 440 | for k in sorted(workers.iterkeys()): 441 | w = workers[k] 442 | t = self.format_dt(now - w['last_time']) + ' ago' 443 | r = self.format_rate(w['hashes'] / min(now - w['first_time'], 444 | self.rate_time), 445 | w['points']) 446 | rejected = w['solutions'] - w['accepted'] 447 | eff = (100. * w['accepted'] / max(1, w['solutions'])) 448 | body += ('' 449 | '' % 450 | (k, r, w['solutions'], rejected, eff, t)) 451 | body += '
WorkerRateSubmissionsRejectionsEfficiencyLast contact
%s%s%d%d%.2f%%%s
' 452 | body += '' 453 | body = body.encode('U8') 454 | headers = {'Date': self.date_time_string(), 455 | 'Content-Type': 'text/html; charset=utf-8', 456 | 'Content-Length': str(len(body))} 457 | self.respond(200, headers, body) 458 | 459 | def format_dt(self, dt): 460 | for v, n in ((86400, 'days'), (3600, 'hours'), (60, 'minutes'), 461 | (1, 'seconds')): 462 | if dt >= 2 * v: 463 | break 464 | return '%d %s' % (dt // v, n) 465 | 466 | def format_rate(self, rate, points): 467 | prefixes = ('', 'k', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y') 468 | k = min(int(math.log10(max(1, rate)) // 3), len(prefixes) - 1) 469 | rate /= 1e3 ** k 470 | p = max(0, min(3, int(math.log10(0.5 * points / rate)))) if rate else 0 471 | return '%.*f %sH/s' % (p, round(rate, p), prefixes[k]) 472 | 473 | 474 | class ThreadingHTTPServer(SocketServer.ThreadingMixIn, 475 | BaseHTTPServer.HTTPServer): pass 476 | 477 | 478 | if __name__ == '__main__': 479 | ap = argparse.ArgumentParser(fromfile_prefix_chars='@') 480 | ap.add_argument('urls', metavar='URL', nargs='+', 481 | help='URL of upstream mining server' 482 | ' (including credentials)') 483 | ap.add_argument('--address', dest='address', default='', 484 | help='address of network interface to listen on' 485 | ' (default: listen on all interfaces)') 486 | ap.add_argument('-p', '--port', dest='port', type=int, default=8345, 487 | help='port to serve on (default: 8345)') 488 | ap.add_argument('-n', '--size', dest='n', type=int, default=100, 489 | help='maximum number of connections to each upstream' 490 | ' server (default: 100)') 491 | ap.add_argument('-T', '--timeout', dest='timeout', type=float, 492 | metavar='N', default=10, 493 | help='timeout for regular getwork requests, in seconds' 494 | ' (default: 10)') 495 | ap.add_argument('--lp-timeout', dest='lp_timeout', type=float, 496 | metavar='N', 497 | help='set a timeout for long polling requests, in seconds') 498 | ap.add_argument('-L', '--lifetime', dest='lifetime', type=float, 499 | metavar='N', default=10, 500 | help='number of seconds a work unit can be reused for' 501 | ' (default: 10)') 502 | ap.add_argument('-f', '--force', dest='force', action='store_true', 503 | help='force reuse of work units') 504 | ap.add_argument('-x', '--proxy', dest='proxy', metavar='HOST:PORT', 505 | help='connect via a HTTP proxy') 506 | ap.add_argument('--sharelog', dest='sharelog', metavar='FILE', 507 | help='log submissions to FILE') 508 | ap.add_argument('--private', dest='private', action='store_true', 509 | help='only allow localhost to access the web interface') 510 | ap.add_argument('-v', '--verbose', dest='verbosity', action='count', 511 | help='increase output verbosity') 512 | args = ap.parse_args() 513 | 514 | if args.verbosity > 1: 515 | loglevel = logging.DEBUG 516 | elif args.verbosity > 0: 517 | loglevel = logging.INFO 518 | else: 519 | loglevel = logging.WARNING 520 | logging.basicConfig(level=loglevel, format='[%(asctime)s] %(message)s', 521 | datefmt='%Y-%m-%d %H:%M:%S') 522 | Pool.timeout = args.timeout 523 | Pool.lp_timeout = args.lp_timeout 524 | Work.timeout = args.lifetime 525 | pools = [Pool(u, args.n, proxy=args.proxy) for u in args.urls] 526 | RollProxyHandler.protocol_version = 'HTTP/1.1' 527 | RollProxyHandler.force_rolls = args.force 528 | if args.sharelog: 529 | RollProxyHandler.sharelog = open(args.sharelog, 'a') 530 | RollProxyHandler.private = args.private 531 | server = ThreadingHTTPServer((args.address, args.port), RollProxyHandler) 532 | server.daemon_threads = True; 533 | logging.info('Serving HTTP on port %d' % args.port) 534 | try: 535 | server.serve_forever() 536 | except (KeyboardInterrupt, SystemExit): 537 | logging.info('Shutting down') 538 | -------------------------------------------------------------------------------- /COPYING: -------------------------------------------------------------------------------- 1 | GNU AFFERO GENERAL PUBLIC LICENSE 2 | Version 3, 19 November 2007 3 | 4 | Copyright (C) 2007 Free Software Foundation, Inc. 5 | Everyone is permitted to copy and distribute verbatim copies 6 | of this license document, but changing it is not allowed. 7 | 8 | Preamble 9 | 10 | The GNU Affero General Public License is a free, copyleft license for 11 | software and other kinds of works, specifically designed to ensure 12 | cooperation with the community in the case of network server software. 13 | 14 | The licenses for most software and other practical works are designed 15 | to take away your freedom to share and change the works. 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Remote Network Interaction; Use with the GNU General Public License. 541 | 542 | Notwithstanding any other provision of this License, if you modify the 543 | Program, your modified version must prominently offer all users 544 | interacting with it remotely through a computer network (if your version 545 | supports such interaction) an opportunity to receive the Corresponding 546 | Source of your version by providing access to the Corresponding Source 547 | from a network server at no charge, through some standard or customary 548 | means of facilitating copying of software. This Corresponding Source 549 | shall include the Corresponding Source for any work covered by version 3 550 | of the GNU General Public License that is incorporated pursuant to the 551 | following paragraph. 552 | 553 | Notwithstanding any other provision of this License, you have 554 | permission to link or combine any covered work with a work licensed 555 | under version 3 of the GNU General Public License into a single 556 | combined work, and to convey the resulting work. The terms of this 557 | License will continue to apply to the part which is the covered work, 558 | but the work with which it is combined will remain governed by version 559 | 3 of the GNU General Public License. 560 | 561 | 14. Revised Versions of this License. 562 | 563 | The Free Software Foundation may publish revised and/or new versions of 564 | the GNU Affero General Public License from time to time. Such new versions 565 | will be similar in spirit to the present version, but may differ in detail to 566 | address new problems or concerns. 567 | 568 | Each version is given a distinguishing version number. If the 569 | Program specifies that a certain numbered version of the GNU Affero General 570 | Public License "or any later version" applies to it, you have the 571 | option of following the terms and conditions either of that numbered 572 | version or of any later version published by the Free Software 573 | Foundation. If the Program does not specify a version number of the 574 | GNU Affero General Public License, you may choose any version ever published 575 | by the Free Software Foundation. 576 | 577 | If the Program specifies that a proxy can decide which future 578 | versions of the GNU Affero General Public License can be used, that proxy's 579 | public statement of acceptance of a version permanently authorizes you 580 | to choose that version for the Program. 581 | 582 | Later license versions may give you additional or different 583 | permissions. However, no additional obligations are imposed on any 584 | author or copyright holder as a result of your choosing to follow a 585 | later version. 586 | 587 | 15. Disclaimer of Warranty. 588 | 589 | THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY 590 | APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT 591 | HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY 592 | OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, 593 | THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 594 | PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM 595 | IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF 596 | ALL NECESSARY SERVICING, REPAIR OR CORRECTION. 597 | 598 | 16. Limitation of Liability. 599 | 600 | IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING 601 | WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS 602 | THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY 603 | GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE 604 | USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF 605 | DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD 606 | PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), 607 | EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF 608 | SUCH DAMAGES. 609 | 610 | 17. Interpretation of Sections 15 and 16. 611 | 612 | If the disclaimer of warranty and limitation of liability provided 613 | above cannot be given local legal effect according to their terms, 614 | reviewing courts shall apply local law that most closely approximates 615 | an absolute waiver of all civil liability in connection with the 616 | Program, unless a warranty or assumption of liability accompanies a 617 | copy of the Program in return for a fee. 618 | 619 | END OF TERMS AND CONDITIONS 620 | 621 | How to Apply These Terms to Your New Programs 622 | 623 | If you develop a new program, and you want it to be of the greatest 624 | possible use to the public, the best way to achieve this is to make it 625 | free software which everyone can redistribute and change under these terms. 626 | 627 | To do so, attach the following notices to the program. It is safest 628 | to attach them to the start of each source file to most effectively 629 | state the exclusion of warranty; and each file should have at least 630 | the "copyright" line and a pointer to where the full notice is found. 631 | 632 | 633 | Copyright (C) 634 | 635 | This program is free software: you can redistribute it and/or modify 636 | it under the terms of the GNU Affero General Public License as published by 637 | the Free Software Foundation, either version 3 of the License, or 638 | (at your option) any later version. 639 | 640 | This program is distributed in the hope that it will be useful, 641 | but WITHOUT ANY WARRANTY; without even the implied warranty of 642 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 643 | GNU Affero General Public License for more details. 644 | 645 | You should have received a copy of the GNU Affero General Public License 646 | along with this program. If not, see . 647 | 648 | Also add information on how to contact you by electronic and paper mail. 649 | 650 | If your software can interact with users remotely through a computer 651 | network, you should also make sure that it provides a way for users to 652 | get its source. For example, if your program is a web application, its 653 | interface could display a "Source" link that leads users to an archive 654 | of the code. There are many ways you could offer source, and different 655 | solutions will be better for different programs; see section 13 for the 656 | specific requirements. 657 | 658 | You should also get your employer (if you work as a programmer) or school, 659 | if any, to sign a "copyright disclaimer" for the program, if necessary. 660 | For more information on this, and how to apply and follow the GNU AGPL, see 661 | . 662 | --------------------------------------------------------------------------------