source: fedd/federation/client_lib.py

#!/usr/local/bin/python

import sys
import pwd
import os
import re
import os.path
import xml.parsers.expat

from string import join
from datetime import datetime

from deter import fedid
from util import fedd_ssl_context, file_expanding_opts
from remote_service import service_caller
from service_error import service_error

from optparse import OptionParser, OptionValueError


class client_opts(file_expanding_opts):
    """
    Standatd set of options that all clients talking to fedd can probably use.
    Client code usually specializes this.
    """

    def __init__(self):
        file_expanding_opts.__init__(self,
                usage="%prog [opts] (--help for details)",
                version="0.1")

        self.add_option("--cert", action="callback", dest="cert", 
                callback=self.expand_file,
                type="string", help="my certificate file")
        self.add_option("--auth_log", action="callback", dest="auth_log",
                callback=self.expand_file, default=None,
                type="string", help="Log authentication decisions to this file")
        self.add_option("--abac", action="callback", dest="abac_dir",
                callback=self.expand_file,
                type="string", default=os.path.expanduser('~/.abac'), 
                help="Directory with abac certs")
        self.add_option('--no_abac', action='store_const', const=None, 
                dest='abac_dir', help='Do not use abac authorization')
        self.add_option( "--debug", action="count", dest="debug", 
                default=0, help="Set debug.  Repeat for more information")
        self.add_option("--serialize_only", action="store_true", 
                dest="serialize_only", default=False,
                help="Print the SOAP request that would be sent and exit")
        self.add_option("--trusted", action="callback", dest="trusted",
                callback=self.expand_file,
                type="string", help="Trusted certificates (required)")
        self.add_option("--url", action="store", dest="url",
                type="string",default=None, help="URL to connect to")
        self.add_option("--transport", action="store", type="choice",
                choices=("xmlrpc", "soap"), default="soap",
                help="Transport for request (xmlrpc|soap) (Default: %default)")
        self.add_option("--trace", action="store_const", dest="tracefile", 
                const=sys.stderr, help="Print SOAP exchange to stderr")

def log_authentication(fn, action, outcome, proof):
    f = open(fn, 'a')
    print >>f, '<comment>%s %s at %s</comment>' % (action, outcome, datetime.now())
    if isinstance(proof, list):
        for p in proof:
            print >>f, p.to_xml()
    else:
        print >>f, proof.to_xml()
    f.close()


def exit_with_fault(exc, action, opts, out=sys.stderr):
    """
    Print an error message and exit.  exc is the RPCException that caused the
    failure.
    """
    codestr = ""

    if exc.errstr: codestr = "Error: %s" % exc.errstr
    else: codestr = ""

    if exc.code:
        if isinstance(exc.code, int): code = exc.code
        else: code = -1

        if len(codestr) > 0 : codestr += " (%d)" % code
        else: codestr = "Error Code: %d" % code
    else:
        code = -1

    if exc.code == service_error.access and opts.auth_log:
        try:
            log_authentication(opts.auth_log, action, 'failed', exc.proof)
        except EnvironmentError, e:
            print >>sys.stderr, "Failed to log to %s: %s" % \
                    (e.filename, e.strerror)

    print>>out, codestr
    print>>out, "Description: %s" % exc.desc
    sys.exit(code)

class RPCException(RuntimeError):
    """
    An error during the RPC exchange.  It unifies errors from both SOAP and
    XMLPRC calls.
    """
    def __init__(self, desc=None, code=None, errstr=None, proof=None):
        RuntimeError.__init__(self)
        self.desc = desc
        if isinstance(code, int): self.code = code
        else: self.code = -1
        self.errstr = errstr
        self.proof = proof

class CertificateMismatchError(RuntimeError): pass


def get_user_cert():
    for c in ("~/.ssl/fedid.pem", "~/.ssl/emulab.pem"):
        cert = os.path.expanduser(c)
        if os.access(cert, os.R_OK):
            break
        else:
            cert = None
    return cert

def get_abac_certs(dir):
    '''
    Return a list of the contents of the files in dir.  These should be abac
    certificates, but that isn't checked.
    '''
    rv = [ ]
    if dir and os.path.isdir(dir):
        for fn in ["%s/%s" % (dir, p) for p in os.listdir(dir) \
                if os.path.isfile("%s/%s" % (dir,p))]:
            f = open(fn, 'r')
            rv.append(f.read())
            f.close()
    return rv

ns_service_re = re.compile('^\\s*#\\s*SERVICE:\\s*([\\S]+)')
xml_service_re = re.compile('SERVICE:\\s*([\\S]+)\\s*$')

def parse_service(svc):
    """
    Pasre a service entry into a hash representing a service entry in a
    message.  The format is:
        svc_name:exporter(s):importer(s):attr=val,attr=val
    The svc_name is the service name, exporter is the exporting testbeds
    (comma-separated) importer is the importing testbeds (if any) and the rest
    are attr=val pairs that will become attributes of the service.  These
    include parameters and other such stuff.
    """

    terms = svc.split(':')
    svcd = { }
    if len(terms) < 2 or len(terms[0]) == 0 or len(terms[1]) == 0:
        sys.exit("Bad service description '%s': Not enough terms" % svc)

    svcd['name'] = terms[0]
    svcd['export'] = terms[1].split(",")
    if len(terms) > 2 and len(terms[2]) > 0:
        svcd['import'] = terms[2].split(",")
    if len(terms) > 3 and len(terms[3]) > 0:
        svcd['fedAttr'] = [ ]
        for t in terms[3].split(";"):
            i = t.find("=")
            if i != -1 :
                svcd['fedAttr'].append(
                        {'attribute': t[0:i], 'value': t[i+1:]})
            else:
                sys.exit("Bad service attribute '%s': no equals sign" % t)
    return svcd

def service_dict_to_line(d):
    """
    Convert a dict containing a service description into a colon separated
    service description suitable for inclusion in a file or command line.
    """

    return 'SERVICE: %s' % (
            ':'.join([
                d.get('name', ''),
                ','.join(d.get('export','')),
                ','.join(d.get('import','')),
                ','.join([
                    '='.join((dd.get('attribute', ''), dd.get('value',''))) \
                        for dd in d.get('fedAttr', [])
                ])
            ]))

def extract_services_from_xml(string=None, file=None, filename=None):
    class parser:
        def __init__(self):
            self.svcs = []
        def comment_handler(self, data):
            for l in data.split('\n'):
                if xml_service_re.match(l):
                    self.svcs.append(
                            parse_service(xml_service_re.match(l).group(1)))

    p = parser()
    xp = xml.parsers.expat.ParserCreate()

    xp.CommentHandler = p.comment_handler

    num_set = len([ x for x in (string, filename, file)\
            if x is not None ])

    if num_set != 1:
        raise RuntimeError("Exactly one one of file, filename and string " + \
                "must be set")
    elif filename:
        f = open(filename, "r")
        xp.ParseFile(f)
        f.close()
    elif file:
        xp.ParseFile(file)
    elif string:
        xp.Parse(string, True)

    return p.svcs

def wrangle_standard_options(opts):
    """
    Look for the certificate to use for the call (check for the standard emulab
    file and any passed in.  Make sure a present cert file can be read.  Make
    sure that any trusted cert file can be read and if the debug level is set,
    set the tracefile attribute as well.  If any of these tests fail, raise a
    RuntimeError.  Otherwise return the certificate file, the fedid, and the
    fedd url.
    """
    default_url="https://localhost:23235"

    if opts.debug > 0: opts.tracefile=sys.stderr

    if opts.trusted:
        if ( not os.access(opts.trusted, os.R_OK) ) :
            raise RuntimeError("Cannot read trusted certificates (%s)" \
                    % opts.trusted)

    cert = get_user_cert()
    if opts.cert: cert = opts.cert

    if cert is None:
        raise RuntimeError("No certificate given (--cert) or found")

    if os.access(cert, os.R_OK):
        fid = fedid(file=cert)
    else:
        raise RuntimeError("Cannot read certificate (%s)" % cert)

    if opts.url: url = opts.url
    elif 'FEDD_URL' in os.environ: url = os.environ['FEDD_URL']
    else: url = default_url

    if opts.abac_dir:
        if not os.access(opts.abac_dir, os.F_OK):
            try:
                os.mkdir(opts.abac_dir, 0700)
            except OSError, e:
                raise RuntimeError("No ABAC directory (could not create): %s" \
                        % opts.abac_dir)

        if not os.path.isdir(opts.abac_dir):
            raise RuntimeError("ABAC directory not a directory: %s" \
                    % opts.abac_dir)
        elif not os.access(opts.abac_dir, os.W_OK):
            raise RuntimeError("Cannot write to ABAC directory: %s" \
                    % opts.abac_dir)



    return (cert, fid, url)

def save_certfile(out_certfile, ea, check_cert=None):
    """
    if the experiment authority section in ea has a certificate and the
    out_certfile parameter has a place to put it, save the cert to the file.
    EnvronmentError s can come from the file operations.  If check_cert is
    given, the certificate in ea is compared with it and if they are not equal,
    a CertificateMismatchError is raised.
    """
    if out_certfile and ea and 'X509' in ea:
        out_cert = ea['X509']
        if check_cert and check_cert != out_cert:
            raise CertificateMismatchError()
        f = open(out_certfile, "w")
        f.write(out_cert)
        f.close()


def do_rpc(req_dict, url, transport, cert, trusted, tracefile=None,
        serialize_only=False, caller=None, responseBody=None):
    """
    The work of sending and parsing the RPC as either XMLRPC or SOAP
    """

    if caller is None: 
        raise RuntimeError("Must provide caller to do_rpc")

    context = None
    while context == None:
        try:
            context = fedd_ssl_context(cert, trusted)
        except Exception, e:
            # Yes, doing this on message type is not ideal.  The string
            # comes from OpenSSL, so check there is this stops working.
            if str(e) == "bad decrypt": 
                print >>sys.stderr, "Bad Passphrase given."
            else: raise

    if transport == "soap":
        if serialize_only:
            print caller.serialize_soap(req_dict) 
            return { }
        else:
            try:
                resp = caller.call_soap_service(url, req_dict, 
                        context=context, tracefile=tracefile)
            except service_error, e:
                raise RPCException(desc=e.desc, code=e.code, 
                        errstr=e.code_string(), proof=e.proof)
    elif transport == "xmlrpc":
        if serialize_only:
            ser = dumps((req_dict,))
            print ser
            return { }
        else:
            try:
                resp = caller.call_xmlrpc_service(url, req_dict, 
                        context=context, tracefile=tracefile)
            except service_error, e:
                raise RPCException(desc=e.desc, code=e.code, 
                        errstr=e.code_string())
    else:
        raise RuntimeError("Unknown RPC transport: %s" % transport)

    if responseBody:
        if responseBody in resp: return resp[responseBody]
        else: raise RuntimeError("No body in response??")
    else:
        return resp

def get_experiment_names(eid):
    """
    eid is the experimentID entry in one of a dict representing a fedd message.
    Pull out the fedid and localname from that hash and return them as fedid,
    localid)
    """
    fedid = None
    local = None
    for id in eid or []:
        for k in id.keys():
            if k =='fedid':
                fedid = id[k]
            elif k =='localname':
                local = id[k]

    return (fedid, local)

class info_format:
    def __init__(self, out=sys.stdout):
        self.out = out
        self.key = {
                'vis': 'vis', 
                'vtopo': 'vtopo',
                'federant': 'federant',
                'experimentdescription': 'experimentdescription',
                'id': 'experimentID',
                'status': 'experimentStatus',
                'log': 'allocationLog',
                'embedding': 'embedding',
            }
        self.formatter = {
                'vis':  self.print_vis_or_vtopo('vis', self.out),
                'vtopo':  self.print_vis_or_vtopo('vtopo', self.out),
                'federant':  self.print_xml,
                'experimentdescription':  self.print_xml,
                'id': self.print_id,
                'status': self.print_string,
                'log': self.print_string,
                'embedding':  self.print_xml,
            }

    def print_string(self, d):
        """
        Print the string to the class output.
        """
        print >>self.out, d

    def print_id(self, d):
        """
        d is an array of ID dicts.  Print each one to the class output.
        """
        for id in d or []:
            for k, i in id.items():
                print >>self.out, "%s: %s" % (k, i)

    def print_xml(self, d):
        """
        Very simple ugly xml formatter of the kinds of dicts that come back
        from services.
        """
        if isinstance(d, dict):
            for k, v in d.items():
                print >>self.out, "<%s>" % k
                self.print_xml(v)
                print >>self.out, "</%s>" % k
        elif isinstance(d, list):
            for x in d:
                self.print_xml(x)
        else:
            print >>self.out, d


    class print_vis_or_vtopo:
        """
        Print the retrieved data is a simple xml representation of the dict.
        """
        def __init__(self, top, out=sys.stdout):
            self.xml = top
            self.out = out

        def __call__(self, d, out=sys.stdout):
            str = "<%s>\n" % self.xml
            for t in ('node', 'lan'):
                if d.has_key(t): 
                    for x in d[t]:
                        str += "<%s>" % t
                        for k in x.keys():
                            str += "<%s>%s</%s>" % (k, x[k],k)
                        str += "</%s>\n" % t
            str+= "</%s>" % self.xml
            print >>self.out, str

    def __call__(self, d, r):
        """
        Print the data of type r (one of the keys of key) to the class output.
        """
        k = self.key.get(r, None)
        if k:
            if k in d: self.formatter[r](d[k])
            else: raise RuntimeError("Bad response: no %s" %k)
        else:
            raise RuntimeError("Don't understand datatype %s" %r)