python socket file transfer

I'm trying to write transfer files or chunks of data over a socket. I feel as if I'm reinventing the wheel, but my searches for a simple solution have failed (everything I find is either too simple or too complex). The server would run on a phone running python 2.5.4. The intended application would be to sync music files between the phone and a host computer.

This is the guts of what I have, which appears to work. I send and receive 'ok' to break up streams.

Is sending 'ok' back and forth essentially as stop bits to break up streams of data a reasonable technique?

Is there a standard way to do this?

Running any sort of library server (ftp, http) on the phone is not a useful solution given the limits of the phone's memory and processing power.

server:

import socket

c = socket.socket(socket.AF_INET,socket.SOCK_STREAM)
c.bind(('', 1234))
c.listen(1)
s,a = c.accept()

while True:
    data = s.recv(1024)
    cmd = data[:data.find('\n')]

    if cmd == 'get':
        x, file_name, x = data.split('\n', 2)
        s.sendall('ok')
        with open(file_name, 'rb') as f:
            data = f.read()
        s.sendall('%16d' % len(data))
        s.sendall(data)
        s.recv(2)

    if cmd == 'end':
        s.close()
        c.close()
        break

client:

import socket

s = socket.socket()
s.connect(('192.168.1.2', 1234))

def get_file(s, file_name):
    cmd = 'get\n%s\n' % (file_name)
    s.sendall(cmd)
    r = s.recv(2)
    size = int(s.recv(16))
    recvd = ''
    while size > len(recvd):
        data = s.recv(1024)
        if not data: 
            break
        recvd += data
    s.sendall('ok')
    return recvd

print get_file(s, 'file1')
print get_file(s, 'file2')
s.sendall('end\n')