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Diff for /src/usr.bin/ssh/Attic/nchan.h between version 1.1 and 1.2

version 1.1, 1999/10/16 20:47:14 version 1.2, 1999/10/16 22:29:01
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   /* RCSID("$Id$"); */
   
 #ifndef NCHAN_H  #ifndef NCHAN_H
 #define NCHAN_H  #define NCHAN_H
   
   
 /*  /*
         SSH Protocol 1.5 aka New Channel Protocol   * SSH Protocol 1.5 aka New Channel Protocol
         Thanks to Martina, Axel and everyone who left Erlangen, leaving me bored.   * Thanks to Martina, Axel and everyone who left Erlangen, leaving me bored.
         Written by Markus Friedl in October 1999   * Written by Markus Friedl in October 1999
    *
    * Protocol versions 1.3 and 1.5 differ in the handshake protocol used for the
    * tear down of channels:
    *
    * 1.3: strict request-ack-protocol:
    *      CLOSE   ->
    *              <-  CLOSE_CONFIRM
    *
    * 1.5: uses variations of:
    *      IEOF    ->
    *              <-  OCLOSE
    *              <-  IEOF
    *      OCLOSE  ->
    *      i.e. both sides have to close the channel
    *
    * See the debugging output from 'ssh -v' and 'sshd -d' of
    * ssh-1.2.27 as an example.
    *
    * Details: (for Channel data structure see channels.h)
    *
    * - the output_buffer gets data received from the remote peer and
    *   is written to the socket,
    * - the input_buffer gets data from the socket and is sent to remote peer.
    * - the socket represents the local object communicating with an object
    *   reachable via the peer
    *
    *      PEER A                                  PEER B
    *
    * read(sock, input_buffer) < 0;
    * shutdown_read();
    * flush(input_buffer) =: DATA
    * send(DATA)                   ->      rcvd(DATA)
    *                                      write(sock, output_buffer:=DATA);
    * send(IEOF)                   ->      rcvd(IEOF)
    *                                      shutdown_write() if:
    *                                              a) write fails
    *                                              b) rcvd_IEOF==true &&
    *                                                 output_buffer==empty
    * rcvd(OCLOSE)                 <-      send(OCLOSE)
    *
    * The channel is now half closed. No data will flow from A to B.
    *
    * Note that each side can remove the channel only if 2 messages
    * have been sent and received and the associated socket has been
    * shutdown, see below:
    */
   
         Protocol versions 1.3 and 1.5 differ in the handshake protocol used for the  
         tear down of channels:  
   
         1.3:    strict request-ack-protocol:  
                 CLOSE   ->  
                         <-  CLOSE_CONFIRM  
   
         1.5:    uses variations of:  
                 IEOF    ->  
                         <-  OCLOSE  
                         <-  IEOF  
                 OCLOSE  ->  
   
         See the debugging output from 'ssh -v' and 'sshd -d' in ssh-1.2.27, for example.  
   
         Details: (for Channel data structure see channels.h)  
   
         the output_buffer gets data received from the remote peer and is written to the socket,  
         the input_buffer gets data from the socket and is sent to remote peer.  
         the socket represents the local object communicating with an object reachable via the peer  
   
                 PEER A                                  PEER B  
   
         read(sock, input_buffer) < 0;  
         shutdown_read();  
         flush(input_buffer) =: DATA  
         send(DATA)                      ->      rcvd(DATA)  
                                                 write(sock, output_buffer:=DATA);  
         send(IEOF)                      ->      rcvd(IEOF)  
                                                 shutdown_write() if:  
                                                         a) write fails  
                                                         b) rcvd_IEOF==true && output_buffer==empty  
                                         <-      send(OCLOSE)  
         rcvd(OCLOSE)                            destroy channel  
         shutdown_read() if not already  
         destroy channel  
   
         Note that each side can close the channel only if 2 messages  
         have been sent and received and the associated socket has been shutdown, see below:  
 */  
   
   
 enum {  enum {
         /* ssh-proto-1.5 overloads message-types */          /* ssh-proto-1.5 overloads message-types */
         CHAN_IEOF   = SSH_MSG_CHANNEL_CLOSE,                    /* no more data from sender */          CHAN_IEOF   = SSH_MSG_CHANNEL_CLOSE,
         CHAN_OCLOSE = SSH_MSG_CHANNEL_CLOSE_CONFIRMATION,       /* all received data has been output */                          /* there will be no more data from sender */
           CHAN_OCLOSE = SSH_MSG_CHANNEL_CLOSE_CONFIRMATION,
                           /* all received data has been written to the socket */
   
         /* channel close flags */          /* channel close flags */
         CHAN_IEOF_SENT          = 0x01,          CHAN_IEOF_SENT          = 0x01,
         CHAN_IEOF_RCVD          = 0x02,          CHAN_IEOF_RCVD          = 0x02,
         CHAN_OCLOSE_SENT        = 0x04,          CHAN_OCLOSE_SENT        = 0x04,
         CHAN_OCLOSE_RCVD        = 0x08,          CHAN_OCLOSE_RCVD        = 0x08,
         CHAN_SHUT_RD            = 0x10,          CHAN_SHUT_RD            = 0x10,
         CHAN_SHUT_WR            = 0x20,          CHAN_SHUT_WR            = 0x20,
   
         /* a channel can be removed if ALL the following flags are set: */          /* a channel can be removed if ALL the following flags are set: */
         CHAN_CLOSED             = CHAN_IEOF_SENT | CHAN_IEOF_RCVD |          CHAN_CLOSED             = CHAN_IEOF_SENT | CHAN_IEOF_RCVD |
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