├── README.md ├── simMetadata.py ├── simDHT.py └── LICENSE /README.md: -------------------------------------------------------------------------------- 1 | # simMetadata 2 | Download metadata from DHT network directly. 3 | 4 | For example: [Btbook - 磁力搜索](http://www.btbook.net) 5 | 6 | Inspired by: [老太太](http://github.com/old-woman) -------------------------------------------------------------------------------- /simMetadata.py: -------------------------------------------------------------------------------- 1 | #!/usr/bin/env python 2 | # encoding: utf-8 3 | import socket 4 | import math 5 | from struct import pack, unpack 6 | from socket import inet_ntoa 7 | from threading import Timer, Thread 8 | from time import sleep, time 9 | from hashlib import sha1 10 | from simDHT import entropy 11 | from bencode import bencode, bdecode 12 | 13 | BT_PROTOCOL = "BitTorrent protocol" 14 | BT_MSG_ID = 20 15 | EXT_HANDSHAKE_ID = 0 16 | 17 | def random_id(): 18 | hash = sha1() 19 | hash.update(entropy(20)) 20 | return hash.digest() 21 | 22 | def send_packet(the_socket, msg): 23 | the_socket.send(msg) 24 | 25 | def send_message(the_socket, msg): 26 | msg_len = pack(">I", len(msg)) 27 | send_packet(the_socket, msg_len + msg) 28 | 29 | def send_handshake(the_socket, infohash): 30 | bt_header = chr(len(BT_PROTOCOL)) + BT_PROTOCOL 31 | ext_bytes = "\x00\x00\x00\x00\x00\x10\x00\x00" 32 | peer_id = random_id() 33 | packet = bt_header + ext_bytes + infohash + peer_id 34 | 35 | send_packet(the_socket, packet) 36 | 37 | def check_handshake(packet, self_infohash): 38 | try: 39 | bt_header_len, packet = ord(packet[:1]), packet[1:] 40 | if bt_header_len != len(BT_PROTOCOL): 41 | return False 42 | except TypeError: 43 | return False 44 | 45 | bt_header, packet = packet[:bt_header_len], packet[bt_header_len:] 46 | if bt_header != BT_PROTOCOL: 47 | return False 48 | 49 | packet = packet[8:] 50 | infohash = packet[:20] 51 | if infohash != self_infohash: 52 | return False 53 | 54 | return True 55 | 56 | def send_ext_handshake(the_socket): 57 | msg = chr(BT_MSG_ID) + chr(EXT_HANDSHAKE_ID) + bencode({"m":{"ut_metadata": 1}}) 58 | send_message(the_socket, msg) 59 | 60 | def request_metadata(the_socket, ut_metadata, piece): 61 | """bep_0009""" 62 | msg = chr(BT_MSG_ID) + chr(ut_metadata) + bencode({"msg_type": 0, "piece": piece}) 63 | send_message(the_socket, msg) 64 | 65 | def get_ut_metadata(data): 66 | ut_metadata = "_metadata" 67 | index = data.index(ut_metadata)+len(ut_metadata) + 1 68 | return int(data[index]) 69 | 70 | def get_metadata_size(data): 71 | metadata_size = "metadata_size" 72 | start = data.index(metadata_size) + len(metadata_size) + 1 73 | data = data[start:] 74 | return int(data[:data.index("e")]) 75 | 76 | def recvall(the_socket, timeout=5): 77 | the_socket.setblocking(0) 78 | total_data = [] 79 | data = "" 80 | begin = time() 81 | 82 | while True: 83 | sleep(0.05) 84 | if total_data and time()-begin > timeout: 85 | break 86 | elif time()-begin > timeout*2: 87 | break 88 | try: 89 | data = the_socket.recv(1024) 90 | if data: 91 | total_data.append(data) 92 | begin = time() 93 | except Exception: 94 | pass 95 | return "".join(total_data) 96 | 97 | def download_metadata(address, infohash, timeout=5): 98 | try: 99 | the_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM) 100 | the_socket.settimeout(5) 101 | the_socket.connect(address) 102 | 103 | # handshake 104 | send_handshake(the_socket, infohash) 105 | packet = the_socket.recv(4096) 106 | 107 | # handshake error 108 | if not check_handshake(packet, infohash): 109 | return 110 | 111 | # ext handshake 112 | send_ext_handshake(the_socket) 113 | packet = the_socket.recv(4096) 114 | 115 | # get ut_metadata and metadata_size 116 | ut_metadata, metadata_size = get_ut_metadata(packet), get_metadata_size(packet) 117 | print 'ut_metadata_size: ', metadata_size 118 | 119 | # request each piece of metadata 120 | metadata = [] 121 | for piece in range(int(math.ceil(metadata_size/(16.0*1024)))): 122 | request_metadata(the_socket, ut_metadata, piece) 123 | packet = recvall(the_socket, timeout) #the_socket.recv(1024*17) # 124 | metadata.append(packet[packet.index("ee")+2:]) 125 | 126 | metadata = "".join(metadata) 127 | 128 | print bdecode(metadata)["name"], "size: ", len(metadata) 129 | # with open(infohash.encode("hex")+'.txt', 'w') as f: 130 | # f.write(metadata) 131 | # print 'write metadata, length:', len(metadata) 132 | 133 | except socket.timeout: 134 | pass 135 | except Exception, e: 136 | print e 137 | 138 | finally: 139 | the_socket.close() -------------------------------------------------------------------------------- /simDHT.py: -------------------------------------------------------------------------------- 1 | #!/usr/bin/env python 2 | # encoding: utf-8 3 | 4 | import socket 5 | import threading 6 | from hashlib import sha1 7 | from random import randint 8 | from struct import unpack 9 | from socket import inet_ntoa 10 | from threading import Timer, Thread 11 | from time import sleep 12 | from collections import deque 13 | from bencode import bencode, bdecode 14 | from Queue import Queue 15 | 16 | import simMetadata 17 | 18 | BOOTSTRAP_NODES = ( 19 | ("router.bittorrent.com", 6881), 20 | ("dht.transmissionbt.com", 6881), 21 | ("router.utorrent.com", 6881) 22 | ) 23 | TID_LENGTH = 2 24 | RE_JOIN_DHT_INTERVAL = 3 25 | TOKEN_LENGTH = 2 26 | 27 | 28 | def entropy(length): 29 | return "".join(chr(randint(0, 255)) for _ in xrange(length)) 30 | 31 | 32 | def random_id(): 33 | h = sha1() 34 | h.update(entropy(20)) 35 | return h.digest() 36 | 37 | 38 | def decode_nodes(nodes): 39 | n = [] 40 | length = len(nodes) 41 | if (length % 26) != 0: 42 | return n 43 | 44 | for i in range(0, length, 26): 45 | nid = nodes[i:i+20] 46 | ip = inet_ntoa(nodes[i+20:i+24]) 47 | port = unpack("!H", nodes[i+24:i+26])[0] 48 | n.append((nid, ip, port)) 49 | 50 | return n 51 | 52 | 53 | def timer(t, f): 54 | Timer(t, f).start() 55 | 56 | 57 | def get_neighbor(target, nid, end=10): 58 | return target[:end]+nid[end:] 59 | 60 | 61 | class KNode(object): 62 | 63 | def __init__(self, nid, ip, port): 64 | self.nid = nid 65 | self.ip = ip 66 | self.port = port 67 | 68 | 69 | class DHTClient(Thread): 70 | 71 | def __init__(self, max_node_qsize): 72 | Thread.__init__(self) 73 | self.setDaemon(True) 74 | self.max_node_qsize = max_node_qsize 75 | self.nid = random_id() 76 | self.nodes = deque(maxlen=max_node_qsize) 77 | 78 | def send_krpc(self, msg, address): 79 | try: 80 | self.ufd.sendto(bencode(msg), address) 81 | except Exception: 82 | pass 83 | 84 | def send_find_node(self, address, nid=None): 85 | nid = get_neighbor(nid, self.nid) if nid else self.nid 86 | tid = entropy(TID_LENGTH) 87 | msg = { 88 | "t": tid, 89 | "y": "q", 90 | "q": "find_node", 91 | "a": { 92 | "id": nid, 93 | "target": random_id() 94 | } 95 | } 96 | self.send_krpc(msg, address) 97 | 98 | def join_DHT(self): 99 | for address in BOOTSTRAP_NODES: 100 | self.send_find_node(address) 101 | 102 | def re_join_DHT(self): 103 | if len(self.nodes) == 0: 104 | self.join_DHT() 105 | timer(RE_JOIN_DHT_INTERVAL, self.re_join_DHT) 106 | 107 | def auto_send_find_node(self): 108 | wait = 1.0 / self.max_node_qsize 109 | while True: 110 | try: 111 | node = self.nodes.popleft() 112 | self.send_find_node((node.ip, node.port), node.nid) 113 | except IndexError: 114 | pass 115 | sleep(wait) 116 | 117 | def process_find_node_response(self, msg, address): 118 | nodes = decode_nodes(msg["r"]["nodes"]) 119 | for node in nodes: 120 | (nid, ip, port) = node 121 | if len(nid) != 20: continue 122 | if ip == self.bind_ip: continue 123 | n = KNode(nid, ip, port) 124 | self.nodes.append(n) 125 | 126 | 127 | class DHTServer(DHTClient): 128 | 129 | def __init__(self, master, bind_ip, bind_port, max_node_qsize): 130 | DHTClient.__init__(self, max_node_qsize) 131 | 132 | self.master = master 133 | self.bind_ip = bind_ip 134 | self.bind_port = bind_port 135 | 136 | self.process_request_actions = { 137 | "get_peers": self.on_get_peers_request, 138 | "announce_peer": self.on_announce_peer_request, 139 | } 140 | 141 | self.ufd = socket.socket(socket.AF_INET, socket.SOCK_DGRAM, socket.IPPROTO_UDP) 142 | self.ufd.bind((self.bind_ip, self.bind_port)) 143 | 144 | timer(RE_JOIN_DHT_INTERVAL, self.re_join_DHT) 145 | 146 | 147 | def run(self): 148 | self.re_join_DHT() 149 | while True: 150 | try: 151 | (data, address) = self.ufd.recvfrom(65536) 152 | msg = bdecode(data) 153 | self.on_message(msg, address) 154 | except Exception: 155 | pass 156 | 157 | def on_message(self, msg, address): 158 | try: 159 | if msg["y"] == "r": 160 | if msg["r"].has_key("nodes"): 161 | self.process_find_node_response(msg, address) 162 | elif msg["y"] == "q": 163 | try: 164 | self.process_request_actions[msg["q"]](msg, address) 165 | except KeyError: 166 | self.play_dead(msg, address) 167 | except KeyError: 168 | pass 169 | 170 | def on_get_peers_request(self, msg, address): 171 | try: 172 | infohash = msg["a"]["info_hash"] 173 | tid = msg["t"] 174 | nid = msg["a"]["id"] 175 | token = infohash[:TOKEN_LENGTH] 176 | msg = { 177 | "t": tid, 178 | "y": "r", 179 | "r": { 180 | "id": get_neighbor(infohash, self.nid), 181 | "nodes": "", 182 | "token": token 183 | } 184 | } 185 | self.send_krpc(msg, address) 186 | except KeyError: 187 | pass 188 | 189 | def on_announce_peer_request(self, msg, address): 190 | try: 191 | infohash = msg["a"]["info_hash"] 192 | token = msg["a"]["token"] 193 | nid = msg["a"]["id"] 194 | tid = msg["t"] 195 | 196 | if infohash[:TOKEN_LENGTH] == token: 197 | if msg["a"].has_key("implied_port ") and msg["a"]["implied_port "] != 0: 198 | port = address[1] 199 | else: 200 | port = msg["a"]["port"] 201 | self.master.log(infohash, (address[0], port)) 202 | except Exception: 203 | print 'error' 204 | pass 205 | finally: 206 | self.ok(msg, address) 207 | 208 | def play_dead(self, msg, address): 209 | try: 210 | tid = msg["t"] 211 | msg = { 212 | "t": tid, 213 | "y": "e", 214 | "e": [202, "Server Error"] 215 | } 216 | self.send_krpc(msg, address) 217 | except KeyError: 218 | pass 219 | 220 | def ok(self, msg, address): 221 | try: 222 | tid = msg["t"] 223 | nid = msg["a"]["id"] 224 | msg = { 225 | "t": tid, 226 | "y": "r", 227 | "r": { 228 | "id": get_neighbor(nid, self.nid) 229 | } 230 | } 231 | self.send_krpc(msg, address) 232 | except KeyError: 233 | pass 234 | 235 | 236 | class Master(Thread): 237 | 238 | def __init__(self): 239 | Thread.__init__(self) 240 | self.setDaemon(True) 241 | self.queue = Queue() 242 | 243 | def run(self): 244 | while True: 245 | self.downloadMetadata() 246 | 247 | def log(self, infohash, address=None): 248 | self.queue.put([address, infohash]) 249 | 250 | def downloadMetadata(self): 251 | # 100 threads for download metadata 252 | for i in xrange(0, 100): 253 | if self.queue.qsize() == 0: 254 | sleep(1) 255 | continue 256 | announce = self.queue.get() 257 | t = threading.Thread(target = simMetadata.download_metadata, args = (announce[0], announce[1])) 258 | t.setDaemon(True) 259 | t.start() 260 | 261 | if __name__ == "__main__": 262 | 263 | # max_node_qsize bigger, bandwith bigger, spped higher 264 | master = Master() 265 | master.start() 266 | 267 | dht = DHTServer(master, "0.0.0.0", 6881, max_node_qsize=200) 268 | dht.start() 269 | dht.auto_send_find_node() -------------------------------------------------------------------------------- /LICENSE: -------------------------------------------------------------------------------- 1 | GNU GENERAL PUBLIC LICENSE 2 | Version 2, June 1991 3 | 4 | Copyright (C) 1989, 1991 Free Software Foundation, Inc., 5 | 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 6 | Everyone is permitted to copy and distribute verbatim copies 7 | of this license document, but changing it is not allowed. 8 | 9 | Preamble 10 | 11 | The licenses for most software are designed to take away your 12 | freedom to share and change it. By contrast, the GNU General Public 13 | License is intended to guarantee your freedom to share and change free 14 | software--to make sure the software is free for all its users. This 15 | General Public License applies to most of the Free Software 16 | Foundation's software and to any other program whose authors commit to 17 | using it. (Some other Free Software Foundation software is covered by 18 | the GNU Lesser General Public License instead.) You can apply it to 19 | your programs, too. 20 | 21 | When we speak of free software, we are referring to freedom, not 22 | price. Our General Public Licenses are designed to make sure that you 23 | have the freedom to distribute copies of free software (and charge for 24 | this service if you wish), that you receive source code or can get it 25 | if you want it, that you can change the software or use pieces of it 26 | in new free programs; and that you know you can do these things. 27 | 28 | To protect your rights, we need to make restrictions that forbid 29 | anyone to deny you these rights or to ask you to surrender the rights. 30 | These restrictions translate to certain responsibilities for you if you 31 | distribute copies of the software, or if you modify it. 32 | 33 | For example, if you distribute copies of such a program, whether 34 | gratis or for a fee, you must give the recipients all the rights that 35 | you have. You must make sure that they, too, receive or can get the 36 | source code. And you must show them these terms so they know their 37 | rights. 38 | 39 | We protect your rights with two steps: (1) copyright the software, and 40 | (2) offer you this license which gives you legal permission to copy, 41 | distribute and/or modify the software. 42 | 43 | Also, for each author's protection and ours, we want to make certain 44 | that everyone understands that there is no warranty for this free 45 | software. If the software is modified by someone else and passed on, we 46 | want its recipients to know that what they have is not the original, so 47 | that any problems introduced by others will not reflect on the original 48 | authors' reputations. 49 | 50 | Finally, any free program is threatened constantly by software 51 | patents. We wish to avoid the danger that redistributors of a free 52 | program will individually obtain patent licenses, in effect making the 53 | program proprietary. To prevent this, we have made it clear that any 54 | patent must be licensed for everyone's free use or not licensed at all. 55 | 56 | The precise terms and conditions for copying, distribution and 57 | modification follow. 58 | 59 | GNU GENERAL PUBLIC LICENSE 60 | TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION 61 | 62 | 0. This License applies to any program or other work which contains 63 | a notice placed by the copyright holder saying it may be distributed 64 | under the terms of this General Public License. The "Program", below, 65 | refers to any such program or work, and a "work based on the Program" 66 | means either the Program or any derivative work under copyright law: 67 | that is to say, a work containing the Program or a portion of it, 68 | either verbatim or with modifications and/or translated into another 69 | language. (Hereinafter, translation is included without limitation in 70 | the term "modification".) Each licensee is addressed as "you". 71 | 72 | Activities other than copying, distribution and modification are not 73 | covered by this License; they are outside its scope. The act of 74 | running the Program is not restricted, and the output from the Program 75 | is covered only if its contents constitute a work based on the 76 | Program (independent of having been made by running the Program). 77 | Whether that is true depends on what the Program does. 78 | 79 | 1. You may copy and distribute verbatim copies of the Program's 80 | source code as you receive it, in any medium, provided that you 81 | conspicuously and appropriately publish on each copy an appropriate 82 | copyright notice and disclaimer of warranty; keep intact all the 83 | notices that refer to this License and to the absence of any warranty; 84 | and give any other recipients of the Program a copy of this License 85 | along with the Program. 86 | 87 | You may charge a fee for the physical act of transferring a copy, and 88 | you may at your option offer warranty protection in exchange for a fee. 89 | 90 | 2. You may modify your copy or copies of the Program or any portion 91 | of it, thus forming a work based on the Program, and copy and 92 | distribute such modifications or work under the terms of Section 1 93 | above, provided that you also meet all of these conditions: 94 | 95 | a) You must cause the modified files to carry prominent notices 96 | stating that you changed the files and the date of any change. 97 | 98 | b) You must cause any work that you distribute or publish, that in 99 | whole or in part contains or is derived from the Program or any 100 | part thereof, to be licensed as a whole at no charge to all third 101 | parties under the terms of this License. 102 | 103 | c) If the modified program normally reads commands interactively 104 | when run, you must cause it, when started running for such 105 | interactive use in the most ordinary way, to print or display an 106 | announcement including an appropriate copyright notice and a 107 | notice that there is no warranty (or else, saying that you provide 108 | a warranty) and that users may redistribute the program under 109 | these conditions, and telling the user how to view a copy of this 110 | License. (Exception: if the Program itself is interactive but 111 | does not normally print such an announcement, your work based on 112 | the Program is not required to print an announcement.) 113 | 114 | These requirements apply to the modified work as a whole. If 115 | identifiable sections of that work are not derived from the Program, 116 | and can be reasonably considered independent and separate works in 117 | themselves, then this License, and its terms, do not apply to those 118 | sections when you distribute them as separate works. But when you 119 | distribute the same sections as part of a whole which is a work based 120 | on the Program, the distribution of the whole must be on the terms of 121 | this License, whose permissions for other licensees extend to the 122 | entire whole, and thus to each and every part regardless of who wrote it. 123 | 124 | Thus, it is not the intent of this section to claim rights or contest 125 | your rights to work written entirely by you; rather, the intent is to 126 | exercise the right to control the distribution of derivative or 127 | collective works based on the Program. 128 | 129 | In addition, mere aggregation of another work not based on the Program 130 | with the Program (or with a work based on the Program) on a volume of 131 | a storage or distribution medium does not bring the other work under 132 | the scope of this License. 133 | 134 | 3. You may copy and distribute the Program (or a work based on it, 135 | under Section 2) in object code or executable form under the terms of 136 | Sections 1 and 2 above provided that you also do one of the following: 137 | 138 | a) Accompany it with the complete corresponding machine-readable 139 | source code, which must be distributed under the terms of Sections 140 | 1 and 2 above on a medium customarily used for software interchange; or, 141 | 142 | b) Accompany it with a written offer, valid for at least three 143 | years, to give any third party, for a charge no more than your 144 | cost of physically performing source distribution, a complete 145 | machine-readable copy of the corresponding source code, to be 146 | distributed under the terms of Sections 1 and 2 above on a medium 147 | customarily used for software interchange; or, 148 | 149 | c) Accompany it with the information you received as to the offer 150 | to distribute corresponding source code. (This alternative is 151 | allowed only for noncommercial distribution and only if you 152 | received the program in object code or executable form with such 153 | an offer, in accord with Subsection b above.) 154 | 155 | The source code for a work means the preferred form of the work for 156 | making modifications to it. For an executable work, complete source 157 | code means all the source code for all modules it contains, plus any 158 | associated interface definition files, plus the scripts used to 159 | control compilation and installation of the executable. However, as a 160 | special exception, the source code distributed need not include 161 | anything that is normally distributed (in either source or binary 162 | form) with the major components (compiler, kernel, and so on) of the 163 | operating system on which the executable runs, unless that component 164 | itself accompanies the executable. 165 | 166 | If distribution of executable or object code is made by offering 167 | access to copy from a designated place, then offering equivalent 168 | access to copy the source code from the same place counts as 169 | distribution of the source code, even though third parties are not 170 | compelled to copy the source along with the object code. 171 | 172 | 4. You may not copy, modify, sublicense, or distribute the Program 173 | except as expressly provided under this License. Any attempt 174 | otherwise to copy, modify, sublicense or distribute the Program is 175 | void, and will automatically terminate your rights under this License. 176 | However, parties who have received copies, or rights, from you under 177 | this License will not have their licenses terminated so long as such 178 | parties remain in full compliance. 179 | 180 | 5. You are not required to accept this License, since you have not 181 | signed it. However, nothing else grants you permission to modify or 182 | distribute the Program or its derivative works. These actions are 183 | prohibited by law if you do not accept this License. Therefore, by 184 | modifying or distributing the Program (or any work based on the 185 | Program), you indicate your acceptance of this License to do so, and 186 | all its terms and conditions for copying, distributing or modifying 187 | the Program or works based on it. 188 | 189 | 6. Each time you redistribute the Program (or any work based on the 190 | Program), the recipient automatically receives a license from the 191 | original licensor to copy, distribute or modify the Program subject to 192 | these terms and conditions. You may not impose any further 193 | restrictions on the recipients' exercise of the rights granted herein. 194 | You are not responsible for enforcing compliance by third parties to 195 | this License. 196 | 197 | 7. If, as a consequence of a court judgment or allegation of patent 198 | infringement or for any other reason (not limited to patent issues), 199 | conditions are imposed on you (whether by court order, agreement or 200 | otherwise) that contradict the conditions of this License, they do not 201 | excuse you from the conditions of this License. If you cannot 202 | distribute so as to satisfy simultaneously your obligations under this 203 | License and any other pertinent obligations, then as a consequence you 204 | may not distribute the Program at all. For example, if a patent 205 | license would not permit royalty-free redistribution of the Program by 206 | all those who receive copies directly or indirectly through you, then 207 | the only way you could satisfy both it and this License would be to 208 | refrain entirely from distribution of the Program. 209 | 210 | If any portion of this section is held invalid or unenforceable under 211 | any particular circumstance, the balance of the section is intended to 212 | apply and the section as a whole is intended to apply in other 213 | circumstances. 214 | 215 | It is not the purpose of this section to induce you to infringe any 216 | patents or other property right claims or to contest validity of any 217 | such claims; this section has the sole purpose of protecting the 218 | integrity of the free software distribution system, which is 219 | implemented by public license practices. Many people have made 220 | generous contributions to the wide range of software distributed 221 | through that system in reliance on consistent application of that 222 | system; it is up to the author/donor to decide if he or she is willing 223 | to distribute software through any other system and a licensee cannot 224 | impose that choice. 225 | 226 | This section is intended to make thoroughly clear what is believed to 227 | be a consequence of the rest of this License. 228 | 229 | 8. If the distribution and/or use of the Program is restricted in 230 | certain countries either by patents or by copyrighted interfaces, the 231 | original copyright holder who places the Program under this License 232 | may add an explicit geographical distribution limitation excluding 233 | those countries, so that distribution is permitted only in or among 234 | countries not thus excluded. In such case, this License incorporates 235 | the limitation as if written in the body of this License. 236 | 237 | 9. The Free Software Foundation may publish revised and/or new versions 238 | of the General Public License from time to time. Such new versions will 239 | be similar in spirit to the present version, but may differ in detail to 240 | address new problems or concerns. 241 | 242 | Each version is given a distinguishing version number. If the Program 243 | specifies a version number of this License which applies to it and "any 244 | later version", you have the option of following the terms and conditions 245 | either of that version or of any later version published by the Free 246 | Software Foundation. If the Program does not specify a version number of 247 | this License, you may choose any version ever published by the Free Software 248 | Foundation. 249 | 250 | 10. If you wish to incorporate parts of the Program into other free 251 | programs whose distribution conditions are different, write to the author 252 | to ask for permission. For software which is copyrighted by the Free 253 | Software Foundation, write to the Free Software Foundation; we sometimes 254 | make exceptions for this. Our decision will be guided by the two goals 255 | of preserving the free status of all derivatives of our free software and 256 | of promoting the sharing and reuse of software generally. 257 | 258 | NO WARRANTY 259 | 260 | 11. BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY 261 | FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN 262 | OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES 263 | PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED 264 | OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 265 | MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS 266 | TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE 267 | PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, 268 | REPAIR OR CORRECTION. 269 | 270 | 12. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING 271 | WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR 272 | REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, 273 | INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING 274 | OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED 275 | TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY 276 | YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER 277 | PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE 278 | POSSIBILITY OF SUCH DAMAGES. 279 | 280 | END OF TERMS AND CONDITIONS 281 | 282 | How to Apply These Terms to Your New Programs 283 | 284 | If you develop a new program, and you want it to be of the greatest 285 | possible use to the public, the best way to achieve this is to make it 286 | free software which everyone can redistribute and change under these terms. 287 | 288 | To do so, attach the following notices to the program. It is safest 289 | to attach them to the start of each source file to most effectively 290 | convey the exclusion of warranty; and each file should have at least 291 | the "copyright" line and a pointer to where the full notice is found. 292 | 293 | {description} 294 | Copyright (C) {year} {fullname} 295 | 296 | This program is free software; you can redistribute it and/or modify 297 | it under the terms of the GNU General Public License as published by 298 | the Free Software Foundation; either version 2 of the License, or 299 | (at your option) any later version. 300 | 301 | This program is distributed in the hope that it will be useful, 302 | but WITHOUT ANY WARRANTY; without even the implied warranty of 303 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 304 | GNU General Public License for more details. 305 | 306 | You should have received a copy of the GNU General Public License along 307 | with this program; if not, write to the Free Software Foundation, Inc., 308 | 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 309 | 310 | Also add information on how to contact you by electronic and paper mail. 311 | 312 | If the program is interactive, make it output a short notice like this 313 | when it starts in an interactive mode: 314 | 315 | Gnomovision version 69, Copyright (C) year name of author 316 | Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. 317 | This is free software, and you are welcome to redistribute it 318 | under certain conditions; type `show c' for details. 319 | 320 | The hypothetical commands `show w' and `show c' should show the appropriate 321 | parts of the General Public License. Of course, the commands you use may 322 | be called something other than `show w' and `show c'; they could even be 323 | mouse-clicks or menu items--whatever suits your program. 324 | 325 | You should also get your employer (if you work as a programmer) or your 326 | school, if any, to sign a "copyright disclaimer" for the program, if 327 | necessary. Here is a sample; alter the names: 328 | 329 | Yoyodyne, Inc., hereby disclaims all copyright interest in the program 330 | `Gnomovision' (which makes passes at compilers) written by James Hacker. 331 | 332 | {signature of Ty Coon}, 1 April 1989 333 | Ty Coon, President of Vice 334 | 335 | This General Public License does not permit incorporating your program into 336 | proprietary programs. If your program is a subroutine library, you may 337 | consider it more useful to permit linking proprietary applications with the 338 | library. If this is what you want to do, use the GNU Lesser General 339 | Public License instead of this License. --------------------------------------------------------------------------------