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34-461: (Redirected from Direct Connect ) Direct connect may refer to: Direct Connect (protocol) , a file sharing client and protocol A protocol used by the program AOL Instant Messenger Sprint Direct Connect , a brand name used by Sprint Corporation for its digital push-to-talk service, similar to a walkie-talkie Direct Connect is an Australian company related to Lumo Energy Topics referred to by

68-447: A connect() request. Connection requests up to this limit will succeed. If the backlog value passed in exceeds the default maximum, then the maximum value is used. After opening a listen channel, the server enters an infinite loop . Inside the loop is a system call to accept() , which puts itself to sleep. The accept() system call will return a file descriptor when a client process executes connect() . Snippet to accept

102-464: A Distributed Denial of Service attack. The hubs may alter the IP in client to client connections, pointing to a potential victim. The CTM Exploit surfaced in 2006–2007, during which period the whole Direct Connect network suffered from DDoS attacks. The situation prompted developers to take security issues more seriously. As of February 2009, an extension for clients was proposed in order for

136-415: A POSIX standard in 2000. The application programming interface has been ported to virtually every Unix implementation and most other operating systems. Both the server and the client must instantiate a socket object by executing the socket() system call . Its usage is: The domain parameter should be one of the following common ranges of communication : The Unix domain socket label

170-503: A Unix domain socket is a Berkeley socket that allows data to be exchanged between two processes executing on the same Unix or Unix-like host computer. This is similar to an Internet domain socket that allows data to be exchanged between two processes executing on different host computers. Regardless of the range of communication (same host or different host), Unix computer programs that perform socket communication are similar. The only range of communication difference

204-504: A listen channel, and then continuously loops . Inside the loop, the server process is put to sleep while waiting to accept a client connection. Upon accepting a client connection, the server then executes a read system call that will block wait . The client connects to the server's socket via the server's address . The client process then writes a message for the server process to read. The application's algorithm may entail multiple read/write interactions. Upon completion of

238-418: A connection: When accept() returns a positive integer, the server engages in an algorithmic dialog with the client. Stream socket input/output may execute the regular-file system calls of read() and write() . However, more control is available if a stream socket executes the socket-specific system calls of send() and recv() . Alternatively, datagram socket input/output should execute

272-412: A particular task simpler. For example, the hub cannot send a user command that will trigger the default browser to visit a website. It can, however, add the command "+rules" (where '+' indicates to the hub that it's a command - this may vary) to display the hub's rules. The peer-to-peer part of the protocol is based on a concept of "slots" (similar to number of open positions for a job). These slots denote

306-498: A user can be in: either "active" or "passive" mode. Clients using active mode can download from anyone else on the network, while clients using passive mode users can only download from active users. In NeoModus Direct Connect, passive mode users receive other passive mode users' search results, but the user will not be able to download anything. In DC++ , users will not receive those search results. In NeoModus Direct Connect, all users will be sent at most five search results per query. If

340-498: A user has searched, DC++ will respond with ten search results when the user is in active mode and five when the user is in passive mode. Passive clients will be sent search results through the hub, while active clients will receive the results directly. Protocol delimiters are "$ ", "|", and U+0020   SPACE . Protocol have for them (and few others) escape sequence and most software use them correctly in login (Lock to Key) sequence. For some reason that escape sequence

374-419: Is a pointer to struct sockaddr . However, the parameter passed to the function is the address of a struct sockaddr_un . struct sockaddr is a generic structure that is not used. It is defined in the formal parameter declaration for bind() . Because each range of communication has its own actual parameter , this generic structure was created as a cast placeholder. After binding to an address,

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408-400: Is an optional port. There is no global identification scheme; instead, users are identified with their nickname on a hub-to-hub basis. An incoming request for a client-client connection cannot be linked with an actual connection. A search result cannot be linked with a particular search. The ability to kick or move (redirect) a user to another hub is supported by the protocol. If a user

442-471: Is different from Wikidata All article disambiguation pages All disambiguation pages Direct Connect (protocol) Hubs feature a list of clients or users connected to them. Users can search for files and download them from other clients, as well as chat with other users. NeoModus was started as a company funded by the adware "Direct Connect" by Jon Hess in November, 1999 while he

476-479: Is kicked, the hub is not required to give that user a specific reason, and there is no restriction on where a user can be redirected to. However, if another client in power instructs the hub to kick, that client may send out a notification message before doing so. Redirecting a user must be accompanied by a reason. There is no HTTP referer equivalent. Hubs may send out user commands to clients. These commands are only raw protocol commands and are used mostly for making

510-470: Is likely inaccurate and/or incomplete. The client-server (as well as client-client, where one client acts as "server") aspect of the protocol stipulates that the server respond first when a connection is being made. For example, when a client connects to a hub's socket , the hub is first to respond to the client. The protocol lacks a specified default character encoding for clients or hubs. The original client and hub use ASCII encoding instead of that of

544-429: Is the method to convert a name to the address parameter needed to bind the socket's connection. For a Unix domain socket , the name is a / path / filename . For an Internet domain socket , the name is an IP address : Port number . In either case, the name is called an address . Two processes may communicate with each other if each obtains a socket. The server process binds its socket to an address , opens

578-436: Is used when the domain parameter's value is AF_UNIX . The Internet domain socket label is used when the domain parameter's value is either AF_INET or AF_INET6 . The type parameter should be one of two common socket types: stream or datagram. A third socket type is available for experimental design: raw. For a Unix domain socket , data ( network packets ) are passed between two connected processes via

612-442: The close() system call: Snippet to close a connection: Snippet to illustrate the end of a dialog: Computer program for the client to instantiate and connect a socket: If connect() returns zero, the client can engage in an algorithmic dialog with the server. The client may send stream data via write( client_socket_fd ) and may receive stream data via read( client_socket_fd ) . Snippet to illustrate client I/O on

646-502: The Operating system . This allows migration to UTF-8 encoding in newer software. Port 411 is the default port for hubs, and 412 for client-to-client connections. If either of these ports are already in use, the port number is incremented until the number of a free port is found for use. For example, if 411, 412 and 413 are in use, then port 414 will be used. Hub addresses are in the following form: dchub://example.com[:411], where 411

680-466: The transport layer — either TCP or UDP. For an Internet domain socket , data are passed between two connected processes via the transport layer and the Internet Protocol (IP) of the network layer — either TCP/IP or UDP/IP. The protocol parameter should be set to zero for stream and datagram sockets. For raw sockets, the protocol parameter should be set to IPPROTO_RAW. Like

714-522: The algorithm, the client executes exit() and the server executes close() . For a Unix domain socket , the socket's address is a /path/filename identifier. The server will create /path/filename on the filesystem to act as a lock file semaphore . No I/O occurs on this file when the client and server send messages to each other. Sockets first appeared in Berkeley Software Distribution 4.2 (1983). It became

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748-521: The attacked party to find out the hub sending the connecting users. The Direct Connect Network Foundation (DCNF) is a non-profit organization registered in Sweden that aims to improve the DC network by improving software, protocols and other services in the network. The DCNF maintains a list of articles, papers and more documentation that relate to DC. Internet socket In client-server computing ,

782-409: The number of people that are allowed to download from a user at any given time and are controlled by the client. In client-to-client connections, the parties generate a random number to see who should be allowed to download first, and the client with the greater number wins. Transporting downloads and connecting to the hub requires TCP , while active searches use UDP . There are two kinds of modes

816-429: The protocol, in comparison with the original protocol, is the broadcasting of Tiger-Tree Hashing of shared files (TTH). The advantages of this include verifying that a file is downloaded correctly, and the ability to find files independently of their names. As the protocol allows hubs to redirect users to other hubs , malicious hubs have redirected users to places other than real Direct Connect hubs, effectively causing

850-408: The regular-file open() system call, the socket() system call returns a file descriptor . The return value's suffix _fd stands for file descriptor . After instantiating a new socket, the server binds the socket to an address. For a Unix domain socket , the address is a /path/filename . Because the socket address may be either a /path/filename or an IP_address:Port_number ,

884-424: The same bandwidth requirements as if it also had been serving the content itself; an estimate shows that handling 1000 users would require about 2.5 mbit/s of bandwidth. There is no official specification of the protocol, meaning that every client and hub (besides the original NeoModus client and hub) has been forced to reverse engineer the information. As such, any protocol specification this article may reference

918-424: The same term [REDACTED] This disambiguation page lists articles associated with the title Direct connect . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=Direct_connect&oldid=821910019 " Category : Disambiguation pages Hidden categories: Short description

952-404: The server opens a listen channel to a port by executing listen() . Its usage is: Snippet to listen: For a Unix domain socket , listen() most likely will succeed and return 0 . For an Internet domain socket , if the port is in use, listen() returns -1 . The backlog parameter sets the queue size for pending connections. The server may be busy when a client executes

986-422: The socket application programming interface requires the address to first be set into a structure. For a Unix domain socket , the structure is: The _un suffix stands for unix . For an Internet domain socket , the suffix will be either _in or _in6 . The sun_ prefix stands for socket unix . Computer program to create and bind a stream Unix domain socket : The second parameter for bind()

1020-414: The socket-specific system calls of sendto() and recvfrom() . For a basic stream socket, the server receives data with read( accept_socket_fd ) and sends data with write( accept_socket_fd ) . Snippet to illustrate I/O on a basic stream socket: The algorithmic dialog ends when either the algorithm concludes or read( accept_socket_fd ) returns < 1 . To close the connection, execute

1054-520: The years 2003–2005. The Direct Connect protocol is a text-based computer protocol, in which commands and their information are sent in clear text, without encryption in original NeoModus software ( encryption is available as a protocol extension). Clients connect to a central server acting as a "hub". This hub provides content discovery and allows clients to negotiate direct connections between each other for transferring content. Since this central hub only deals with metadata, it does not have anywhere near

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1088-521: Was ignored by DC++ developers and they use HTML equivalent if these characters are to be viewed by the user. Continued interest exists in features such as ratings and language packs. The authors of DC++ also proposed a complete replacement of the Direct Connect protocol called ADC, or unofficially, Advanced Direct Connect. ADC uses the same network topology , concepts, and terminology as the original protocol. One example of an added feature to

1122-446: Was in high school. The first third-party client was called "DClite", which never fully supported the file sharing aspects of the protocol. Hess released a new version of Direct Connect, requiring a simple encryption key to initiate a connection, locking out third-party clients. The encryption key was cracked, and the author of DClite released a new version of DClite compatible with the new software from NeoModus. Some time after, DClite

1156-478: Was rewritten as Open Direct Connect with the purpose of having an MDI user interface and using plug-ins for file sharing protocols (similar to MLDonkey ). Open Direct Connect also did not have complete support for the full file sharing aspects of the protocol, but a port to Java , however, did. Later on, other clients such as DCTC (Direct Connect Text Client) and DC++ became popular. The DCDev archive contains discussions of protocol changes for development of DC in

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