common/userttyconn.cc

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//
// The UserTTYConn class - connect to a direct-to-the-user tty...
//
// ***** BEGIN LICENSE BLOCK *****
// Version: MPL 1.1/GPL 2.0/LGPL 2.1
// 
// The contents of this file are subject to the Mozilla Public License
// Version 1.1 (the "License"); you may not use this file except in
// compliance with the License. You may obtain a copy of the License at
// http://www.mozilla.org/MPL/
// 
// Software distributed under the License is distributed on an "AS IS"
// basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
// the License for the specific language governing rights and limitations
// under the License.
// 
// The Original Code is the consmgr network/serial-line monitoring package.
// 
// The Initial Developer of the Original Code is Chris P. Ross.
// Portions created by the Initial Developer are Copyright (C) 2000-2008
// the Initial Developer.  All Rights Reserved.
// 
// Contributor(s):
//   Geoff Adams
// 
// Alternatively, the contents of this file may be used under the terms of
// either the GNU General Public License Version 2 or later (the "GPL"), or
// the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
// in which case the provisions of the GPL or the LGPL are applicable instead
// of those above. If you wish to allow use of your version of this file only
// under the terms of either the GPL or the LGPL, and not to allow others to
// use your version of this file under the terms of the MPL, indicate your
// decision by deleting the provisions above and replace them with the notice
// and other provisions required by the GPL or the LGPL. If you do not delete
// the provisions above, a recipient may use your version of this file under
// the terms of any one of the MPL, the GPL or the LGPL.
// 
// ***** END LICENSE BLOCK *****

extern "C" {
#include <unistd.h>
#include <fcntl.h>
#include <signal.h>
}

#include "consmgr.h"
#include "userttyconn.h"

#define OOB_MARKER      0x1c

#warning "The ability of UserTTYConn to remove the control bytes from the data stream has been removed.  This might need to be fixed if we don't move all of this out into a protocol."

#if 0
// Look for OOB command sequences in the user input
void
UserTTYConn::process_data(Data *blob)
{
    clog << "UserTTYConn::process_data: Got Data of length " << blob->len() << endl;

    if (blob->len() < 1)
        return;

    // Now, loop through the data, looking for OOB command sequences.
    unsigned char *data = blob->data();
    size_t i = 0;
    while (i < blob->len()) {
        if (in_oob_sequence) {
            if (handle_oob_sequence(blob, i))
                in_oob_sequence = false;
        } else if (at_line_start && *data == OOB_MARKER) {
            in_oob_sequence = true;
//          blob->del_range(i, 1);
        } else {
            // It's an in-band character.
            at_line_start = (*data == '\n' || *data == '\r');
            i++;
        }
    }

    // (Note that, in the above, an OOB command sequence must occur at the
    // start of a line, and does not add any in-band data, so it leaves us
    // at the start of the line.)
}
#endif

// Returns whether the OOB sequence is complete. (There might be some more
// expected characters coming in a subsequent Blob.)
bool
UserTTYConn::handle_oob_sequence(Data *blob, size_t offset)
{
    if (blob->len() == 0)
        return false;

    // We only handle single-byte commands (after the OOB_MARKER) for now,
    // so this is pretty easy.
    unsigned char c = blob->data()[offset];
    switch (c) {
        case OOB_MARKER:
            // Leave the marker character in place; this allows the user
            // to send the OOB marker character by typing it twice. In
            // order for the OOB parser not to consume this character,
            // though, we need to trick it by indicating that this is not
            // at the start of a line. In fact, that will be true the
            // moment this character is sent, anyway.
            at_line_start = false;
            break;
        case '.':
            // XXX - Need to send a message to the main program to quit.
            // Let's be a little rude for now.
            // Actually, what we should do is send a disconnection message to
            // our owning Messageable. It's up to the Connection object to
            // decide that the user disconnecting means the program should quit.
            //cerr << "Killing me softly..." << endl;
            kill(getpid(), SIGTERM);
            break; // NOTREACHED
        case '?':
            // XXX - Need to send a message to the main program to print
            // out an OOB-command help message.
            break;
    }

#if 0
    if (c != OOB_MARKER)
        blob->del_range(offset, 1);
#endif

    return true;
}

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