move some things around

2 files changed, 191 insertions, 0 deletions

diff --git a/termcast_client/__init__.py b/termcast_client/__init__.py
new file mode 100644
index 0000000..64e6c2a
--- /dev/null
+++ b/termcast_client/__init__.py
@@ -0,0 +1,97 @@
+import argparse
+import json
+import os
+import pity
+import shutil
+import signal
+import socket
+import sys
+
+class Client(object):
+    def __init__(self, host, port, username, password):
+        self.host = host
+        self.port = port
+        self.username = username
+        self.password = password
+
+    def run(self, argv):
+        sock = socket.socket()
+        sock.connect((self.host, self.port))
+        sock.send(self._build_connection_string())
+        self.winch_set = False
+        pity.spawn(
+            argv,
+            lambda fd: self._master_read(fd, sock),
+            handle_window_size=True
+        )
+
+    def _master_read(self, fd, sock):
+        if not self.winch_set:
+            prev_handler = signal.getsignal(signal.SIGWINCH)
+            signal.signal(
+                signal.SIGWINCH,
+                lambda signum, frame: self._winch(
+                    sock,
+                    lambda: prev_handler(signum, frame)
+                )
+            )
+            self.winch_set = True
+
+        data = os.read(fd, 1024)
+        sock.send(data)
+        return data
+
+    def _winch(self, sock, prev_handler):
+        prev_handler()
+        # XXX a bit racy - should try to avoid splitting existing escape
+        # sequences
+        sock.send(self._build_winsize_metadata_string())
+
+    def _build_connection_string(self):
+        auth = (
+            b'hello ' +
+            self.username.encode('utf-8') +
+            b' ' +
+            self.password.encode('utf-8') +
+            b'\n'
+        )
+        metadata = self._build_connection_metadata_string()
+        return auth + metadata
+
+    def _build_connection_metadata_string(self):
+        # for now
+        return self._build_winsize_metadata_string()
+
+    def _build_winsize_metadata_string(self):
+        size = shutil.get_terminal_size()
+        return self._build_metadata_string({
+            "geometry": [ size.columns, size.lines ],
+        })
+
+    def _build_metadata_string(self, data):
+        return b'\033]499;' + json.dumps(data).encode('utf-8') + b'\007'
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser()
+    parser.add_argument('--host', default="noway.ratry.ru")
+    parser.add_argument('--port', type=int, default=31337)
+    parser.add_argument('--username', default=os.getenv("USER"))
+    parser.add_argument('--password', default="asdf")
+    parser.add_argument(
+        'command',
+        nargs=argparse.REMAINDER,
+    )
+
+    args = parser.parse_args(sys.argv[1:])
+
+    client = Client(
+        host=args.host,
+        port=args.port,
+        username=args.username,
+        password=args.password,
+    )
+
+    command = args.command
+    if len(args.command) < 1:
+        command = os.getenv("SHELL", default="/bin/sh")
+    client.run(command)
diff --git a/termcast_client/pity.py b/termcast_client/pity.py
new file mode 100644
index 0000000..26a9e49
--- /dev/null
+++ b/termcast_client/pity.py
@@ -0,0 +1,94 @@
+import fcntl
+import os
+import pty
+import signal
+import termios
+import tty
+
+CHILD = pty.CHILD
+STDIN_FILENO = pty.STDIN_FILENO
+STDOUT_FILENO = pty.STDOUT_FILENO
+STDERR_FILENO = pty.STDERR_FILENO
+
+def fork(handle_window_size=False):
+    # copied from pty.py, with modifications
+    master_fd, slave_fd = openpty()
+    slave_name = os.ttyname(slave_fd)
+    pid = os.fork()
+    if pid == CHILD:
+        # Establish a new session.
+        os.setsid()
+        os.close(master_fd)
+
+        if handle_window_size:
+            clone_window_size_from(slave_name, STDIN_FILENO)
+
+        # Slave becomes stdin/stdout/stderr of child.
+        os.dup2(slave_fd, STDIN_FILENO)
+        os.dup2(slave_fd, STDOUT_FILENO)
+        os.dup2(slave_fd, STDERR_FILENO)
+        if (slave_fd > STDERR_FILENO):
+            os.close (slave_fd)
+
+        # Explicitly open the tty to make it become a controlling tty.
+        tmp_fd = os.open(os.ttyname(STDOUT_FILENO), os.O_RDWR)
+        os.close(tmp_fd)
+    else:
+        os.close(slave_fd)
+
+    # Parent and child process.
+    return pid, master_fd, slave_name
+
+
+def openpty():
+    return pty.openpty()
+
+def spawn(argv, master_read=pty._read, stdin_read=pty._read, handle_window_size=False):
+    # copied from pty.py, with modifications
+    # note that it references a few private functions - would be nice to not
+    # do that, but you know
+    if type(argv) == type(''):
+        argv = (argv,)
+    pid, master_fd, slave_name = fork(handle_window_size)
+    if pid == CHILD:
+        os.execlp(argv[0], *argv)
+    try:
+        mode = tty.tcgetattr(STDIN_FILENO)
+        tty.setraw(STDIN_FILENO)
+        restore = 1
+    except tty.error:    # This is the same as termios.error
+        restore = 0
+
+    if handle_window_size:
+        signal.signal(
+            signal.SIGWINCH,
+            lambda signum, frame: _winch(slave_name, pid)
+        )
+
+    while True:
+        try:
+            pty._copy(master_fd, master_read, stdin_read)
+        except InterruptedError:
+            continue
+        except OSError:
+            if restore:
+                tty.tcsetattr(STDIN_FILENO, tty.TCSAFLUSH, mode)
+        break
+
+    os.close(master_fd)
+    return os.waitpid(pid, 0)[1]
+
+def clone_window_size_from(slave_name, from_fd):
+    slave_fd = os.open(slave_name, os.O_RDWR)
+    try:
+        fcntl.ioctl(
+            slave_fd,
+            termios.TIOCSWINSZ,
+            fcntl.ioctl(from_fd, termios.TIOCGWINSZ, " " * 1024)
+        )
+    finally:
+        os.close(slave_fd)
+
+def _winch(slave_name, child_pid):
+    clone_window_size_from(slave_name, STDIN_FILENO)
+    os.kill(child_pid, signal.SIGWINCH)