def test_with_segment_ttl(self, db_rec, time):
segment_ttl = 300
inst = PathSegmentDB(segment_ttl)
cur_rec = create_mock(['pcb', 'id', 'exp_time'])
cur_rec.pcb = self._mk_pcb(0)
cur_rec.exp_time = 10
inst._db = create_mock_full(return_value={0: {'record': cur_rec}})
pcb = self._mk_pcb(1)
db_rec.return_value = create_mock(['id'])
time.return_value = 1
# Call
inst.update(pcb)
# Tests
db_rec.assert_called_once_with(pcb, segment_ttl + time.return_value)
ntools.eq_(cur_rec.exp_time, 301)
def test_outdated(self, db_rec):
inst = PathSegmentDB()
pcb = self._mk_pcb(-1)
cur_rec = create_mock_full({"pcb": self._mk_pcb(0)})
inst._db = create_mock_full(return_value={0: {'record': cur_rec}})
record = create_mock_full({'id': "idstr"})
db_rec.return_value = record
# Call
ntools.eq_(inst.update(pcb), DBResult.NONE)
# Tests
pcb.get_expiration_time.assert_called_once_with()
cur_rec.pcb.get_expiration_time.assert_called_once_with()
def test_add(self, db_rec):
inst = PathSegmentDB()
inst._db = create_mock_full({'insert()': None}, return_value=[])
pcb = self._mk_pcb()
record = create_mock_full({'id': "id str"})
db_rec.return_value = record
# Call
ntools.eq_(inst.update(pcb), DBResult.ENTRY_ADDED)
# Tests
db_rec.assert_called_once_with(pcb)
inst._db.assert_called_once_with(id="id str", sibra=True)
inst._db.insert.assert_called_once_with(record, "id str", 1, 2, 3, 4,
True)
def test_update(self, db_rec):
inst = PathSegmentDB()
pcb = self._mk_pcb(1)
cur_rec = create_mock_full({
"pcb": self._mk_pcb(0),
"id": "cur rec",
"exp_time": 44
})
inst._db = create_mock_full(return_value={0: {'record': cur_rec}})
db_rec.return_value = create_mock_full({
'id': "record",
'exp_time': 32
})
# Call
ntools.eq_(inst.update(pcb), DBResult.ENTRY_UPDATED)
# Tests
ntools.eq_(cur_rec.pcb, pcb)
class SibraServerBase(SCIONElement):
"""
Base class for the SIBRA service, which is responsible for managing steady
paths on all interfaces in the local AS.
"""
SERVICE_TYPE = ServiceType.SIBRA
PST_TYPE = None
def __init__(self, server_id, conf_dir, prom_export=None):
"""
:param str server_id: server identifier.
:param str conf_dir: configuration directory.
:param str prom_export: prometheus export address.
"""
super().__init__(server_id, conf_dir, prom_export=prom_export)
self.sendq = Queue()
self.signing_key = get_sig_key(self.conf_dir)
self.segments = PathSegmentDB(max_res_no=1)
# Maps of {ISD-AS: {steady path id: steady path}} for all incoming
# (srcs) and outgoing (dests) steady paths:
self.srcs = {}
self.dests = {}
# Map of SibraState objects by interface ID
self.link_states = {}
# Map of link types by interface ID
self.link_types = {}
self.lock = threading.Lock()
self.CTRL_PLD_CLASS_MAP = {
PayloadClass.PATH: {
PMT.REG: self.handle_path_reg
},
PayloadClass.SIBRA: {
PayloadClass.SIBRA: self.handle_sibra_pkt
},
}
self._find_links()
zkid = ZkID.from_values(self.addr.isd_as, self.id,
[(self.addr.host, self._port)]).pack()
self.zk = Zookeeper(self.addr.isd_as, self.SERVICE_TYPE, zkid,
self.topology.zookeepers)
self.zk.retry("Joining party", self.zk.party_setup)
def _find_links(self):
for br in self.topology.border_routers:
for ifid, intf in br.interfaces.items():
self.link_states[ifid] = SibraState(intf.bandwidth,
self.addr.isd_as)
self.link_types[ifid] = intf.link_type
def run(self):
threading.Thread(target=thread_safety_net,
args=(self.worker, ),
name="SB.worker",
daemon=True).start()
threading.Thread(target=thread_safety_net,
args=(self.sender, ),
name="SB.sender",
daemon=True).start()
super().run()
def worker(self):
# Cycle time should be << SIBRA_TICK, as it determines how often
# reservations are potentially renewed, and the expiration of old
# reservation blocks.
worker_cycle = 1.0
start = SCIONTime.get_time()
while self.run_flag.is_set():
sleep_interval(start, worker_cycle, "SB.worker cycle")
start = SCIONTime.get_time()
with self.lock:
self.manage_steady_paths()
def sender(self):
"""
Handle sending packets on behalf of Link/SteadyPath objects through the
local socket.
"""
while self.run_flag.is_set():
spkt = self.sendq.get()
dst, port = self.get_first_hop(spkt)
if not dst:
logging.error("Unable to determine first hop for packet:\n%s",
spkt)
continue
spkt.addrs.src.host = self.addr.host
logging.debug("Dst: %s Port: %s\n%s", dst, port, spkt)
self.send(spkt, dst, port)
def handle_path_reg(self, cpld, meta):
"""
Handle path registration packets from the local beacon service. First
determine which interface the segments use, then pass the segment to the
appropriate Link.
"""
pmgt = cpld.union
payload = pmgt.union
assert isinstance(payload, PathRecordsReg), type(payload)
meta.close()
name = PST.to_str(self.PST_TYPE)
with self.lock:
for type_, pcb in payload.iter_pcbs():
if type_ == self.PST_TYPE:
self._add_segment(pcb, name)
def _add_segment(self, pcb, name):
res = self.segments.update(pcb)
if res == DBResult.ENTRY_ADDED:
logging.info("%s Segment added: %s", name, pcb.short_desc())
elif res == DBResult.ENTRY_UPDATED:
logging.debug("%s Segment updated: %s", name, pcb.short_desc())
isd_as = pcb.first_ia()
if isd_as not in self.dests:
logging.debug("Found new destination ISD-AS: %s", isd_as)
self.dests[isd_as] = {}
for steady in self.dests[isd_as].values():
steady.update_seg(pcb)
def handle_sibra_pkt(self, pkt):
"""
Handle SIBRA packets. First determine which interface they came from,
then pass them to the appropriate Link.
"""
ext = find_ext_hdr(pkt, ExtensionClass.HOP_BY_HOP,
SibraExtSteady.EXT_TYPE)
if not ext:
logging.error("Packet contains no SIBRA extension header")
return
if not ext.steady:
logging.error("Received non-steady SIBRA packet:\n%s", pkt)
return
if not ext.req_block:
logging.error("Received non-request SIBRA packet:\n%s", pkt)
return
with self.lock:
if ext.fwd:
self._process_req(pkt, ext)
else:
self._process_reply(pkt, ext)
def _process_req(self, pkt, ext):
"""Process a steady path request."""
path_id = ext.path_ids[0]
self.srcs.setdefault(ext.src_ia, {})
if ext.setup and path_id in self.srcs[ext.src_ia]:
logging.error("Setup request for existing path id: %s\n%s",
hex_str(path_id), pkt)
return
elif not ext.setup and path_id not in self.srcs[ext.src_ia]:
logging.error("Renewal request for non-existant path id: %s\n%s",
hex_str(path_id), pkt)
return
ifid = find_last_ifid(pkt, ext)
if ifid not in self.link_states:
logging.error("Packet came from unknown interface '%s':\n%s", ifid,
pkt)
return
if not ext.accepted:
# Request was already rejected, so just send the packet back.
pkt.reverse()
self.sendq.put(pkt)
return
state = self.link_states[ifid]
req_info = ext.req_block.info
bwsnap = req_info.bw.to_snap()
bwhint = state.add_steady(path_id, req_info.index, bwsnap,
req_info.exp_tick, True, ext.setup)
if bwhint is not None:
# This shouldn't happen - if the local BR accepted the reservation,
# then there should be enough bandwidth available for it. This means
# our state is out of sync.
logging.critical("Requested: %s Available bandwidth: %s\n%s",
bwsnap, bwhint, pkt)
return
self.srcs[ext.src_ia][path_id] = None
# All is good, return the packet to the requestor.
pkt.reverse()
self.sendq.put(pkt)
def _process_reply(self, pkt, ext):
"""Process a reply to a steady path request."""
path_id = ext.path_ids[0]
dest = pkt.addrs.src.isd_as
steady = self.dests[dest].get(path_id, None)
if not steady:
logging.error("Unknown path ID: %s:\n%s", hex_str(path_id), pkt)
return
steady.process_reply(pkt, ext)
def manage_steady_paths(self):
"""Create or renew steady paths to all destinations."""
now = time.time()
for isd_as, steadies in self.dests.items():
if not steadies and (now - self._startup >= STARTUP_WAIT):
self._steady_add(isd_as)
continue
for id_, steady in list(steadies.items()):
try:
steady.renew()
except SteadyPathErrorNoReservation:
del steadies[id_]
def _steady_add(self, isd_as):
seg = self._pick_seg(isd_as)
if not seg:
del self.dests[isd_as]
return
ifid = seg.last_hof().ingress_if
link_state = self.link_states[ifid]
link_type = self.link_types[ifid]
# FIXME(kormat): un-hardcode these bandwidths
bwsnap = BWSnapshot(500 * 1024, 500 * 1024)
steady = SteadyPath(self.addr, self._port, self.sendq,
self.signing_key, link_type, link_state, seg,
bwsnap)
self.dests[isd_as][steady.id] = steady
logging.debug("Setting up steady path %s -> %s over %s",
self.addr.isd_as, isd_as, seg.short_desc())
steady.setup()
def _pick_seg(self, isd_as):
"""Select the segment to use for a steady path."""
# FIXME(kormat): this needs actual logic
# For now, we use the shortest path
segs = self.segments(first_ia=isd_as)
if segs:
return segs[0]
if not self._quiet_startup():
logging.warning("No segments to %s", isd_as)
class SCIONDaemon(SCIONElement):
"""
The SCION Daemon used for retrieving and combining paths.
"""
MAX_REQS = 1024
# Time a path segment is cached at a host (in seconds).
SEGMENT_TTL = 300
# Empty Path TTL
EMPTY_PATH_TTL = SEGMENT_TTL
def __init__(self, conf_dir, addr, api_addr, run_local_api=False,
port=None, spki_cache_dir=GEN_CACHE_PATH, prom_export=None, delete_sock=False):
"""
Initialize an instance of the class SCIONDaemon.
"""
super().__init__("sciond", conf_dir, spki_cache_dir=spki_cache_dir,
prom_export=prom_export, public=[(addr, port)])
up_labels = {**self._labels, "type": "up"} if self._labels else None
down_labels = {**self._labels, "type": "down"} if self._labels else None
core_labels = {**self._labels, "type": "core"} if self._labels else None
self.up_segments = PathSegmentDB(segment_ttl=self.SEGMENT_TTL, labels=up_labels)
self.down_segments = PathSegmentDB(segment_ttl=self.SEGMENT_TTL, labels=down_labels)
self.core_segments = PathSegmentDB(segment_ttl=self.SEGMENT_TTL, labels=core_labels)
self.rev_cache = RevCache()
# Keep track of requested paths.
self.requested_paths = ExpiringDict(self.MAX_REQS, PATH_REQ_TOUT)
self.req_path_lock = threading.Lock()
self._api_sock = None
self.daemon_thread = None
os.makedirs(SCIOND_API_SOCKDIR, exist_ok=True)
self.api_addr = (api_addr or get_default_sciond_path())
if delete_sock:
try:
os.remove(self.api_addr)
except OSError as e:
if e.errno != errno.ENOENT:
logging.error("Could not delete socket %s: %s" % (self.api_addr, e))
self.CTRL_PLD_CLASS_MAP = {
PayloadClass.PATH: {
PMT.REPLY: self.handle_path_reply,
PMT.REVOCATION: self.handle_revocation,
},
PayloadClass.CERT: {
CertMgmtType.CERT_CHAIN_REQ: self.process_cert_chain_request,
CertMgmtType.CERT_CHAIN_REPLY: self.process_cert_chain_reply,
CertMgmtType.TRC_REPLY: self.process_trc_reply,
CertMgmtType.TRC_REQ: self.process_trc_request,
},
}
self.SCMP_PLD_CLASS_MAP = {
SCMPClass.PATH:
{SCMPPathClass.REVOKED_IF: self.handle_scmp_revocation},
}
if run_local_api:
self._api_sock = ReliableSocket(bind_unix=(self.api_addr, "sciond"))
self._socks.add(self._api_sock, self.handle_accept)
@classmethod
def start(cls, conf_dir, addr, api_addr=None, run_local_api=False, port=0):
"""
Initializes and starts a SCIOND instance.
"""
inst = cls(conf_dir, addr, api_addr, run_local_api, port)
name = "SCIONDaemon.run %s" % inst.addr.isd_as
inst.daemon_thread = threading.Thread(
target=thread_safety_net, args=(inst.run,), name=name, daemon=True)
inst.daemon_thread.start()
logging.debug("sciond started with api_addr = %s", inst.api_addr)
def _get_msg_meta(self, packet, addr, sock):
if sock != self._udp_sock:
return packet, SockOnlyMetadata.from_values(sock) # API socket
else:
return super()._get_msg_meta(packet, addr, sock)
def handle_msg_meta(self, msg, meta):
"""
Main routine to handle incoming SCION messages.
"""
if isinstance(meta, SockOnlyMetadata): # From SCIOND API
try:
sciond_msg = SCIONDMsg.from_raw(msg)
except SCIONParseError as err:
logging.error(str(err))
return
self.api_handle_request(sciond_msg, meta)
return
super().handle_msg_meta(msg, meta)
def handle_path_reply(self, cpld, meta):
"""
Handle path reply from local path server.
"""
pmgt = cpld.union
path_reply = pmgt.union
assert isinstance(path_reply, PathSegmentReply), type(path_reply)
recs = path_reply.recs()
for srev_info in recs.iter_srev_infos():
self.check_revocation(srev_info, lambda x: self.continue_revocation_processing(
srev_info) if not x else False, meta)
req = path_reply.req()
key = req.dst_ia(), req.flags()
with self.req_path_lock:
r = self.requested_paths.get(key)
if r:
r.notify_reply(path_reply)
else:
logging.warning("No outstanding request found for %s", key)
for type_, pcb in recs.iter_pcbs():
seg_meta = PathSegMeta(pcb, self.continue_seg_processing,
meta, type_, params=(r,))
self._process_path_seg(seg_meta, cpld.req_id)
def continue_revocation_processing(self, srev_info):
self.rev_cache.add(srev_info)
self.remove_revoked_segments(srev_info.rev_info())
def continue_seg_processing(self, seg_meta):
"""
For every path segment(that can be verified) received from the path
server this function gets called to continue the processing for the
segment.
The segment is added to pathdb and pending requests are checked.
"""
pcb = seg_meta.seg
type_ = seg_meta.type
# Check that segment does not contain a revoked interface.
if not self.check_revoked_interface(pcb, self.rev_cache):
return
map_ = {
PST.UP: self._handle_up_seg,
PST.DOWN: self._handle_down_seg,
PST.CORE: self._handle_core_seg,
}
map_[type_](pcb)
r = seg_meta.params[0]
if r:
r.verified_segment()
def _handle_up_seg(self, pcb):
if self.addr.isd_as != pcb.last_ia():
return None
if self.up_segments.update(pcb) == DBResult.ENTRY_ADDED:
logging.debug("Up segment added: %s", pcb.short_desc())
return pcb.first_ia()
return None
def _handle_down_seg(self, pcb):
last_ia = pcb.last_ia()
if self.addr.isd_as == last_ia:
return None
if self.down_segments.update(pcb) == DBResult.ENTRY_ADDED:
logging.debug("Down segment added: %s", pcb.short_desc())
return last_ia
return None
def _handle_core_seg(self, pcb):
if self.core_segments.update(pcb) == DBResult.ENTRY_ADDED:
logging.debug("Core segment added: %s", pcb.short_desc())
return pcb.first_ia()
return None
def api_handle_request(self, msg, meta):
"""
Handle local API's requests.
"""
mtype = msg.type()
if mtype == SMT.PATH_REQUEST:
threading.Thread(
target=thread_safety_net,
args=(self._api_handle_path_request, msg, meta),
daemon=True).start()
elif mtype == SMT.REVOCATION:
self._api_handle_rev_notification(msg, meta)
elif mtype == SMT.AS_REQUEST:
self._api_handle_as_request(msg, meta)
elif mtype == SMT.IF_REQUEST:
self._api_handle_if_request(msg, meta)
elif mtype == SMT.SERVICE_REQUEST:
self._api_handle_service_request(msg, meta)
elif mtype == SMT.SEGTYPEHOP_REQUEST:
self._api_handle_seg_type_request(msg, meta)
else:
logging.warning(
"API: type %s not supported.", TypeBase.to_str(mtype))
def _api_handle_path_request(self, pld, meta):
request = pld.union
assert isinstance(request, SCIONDPathRequest), type(request)
req_id = pld.id
dst_ia = request.dst_ia()
src_ia = request.src_ia()
if not src_ia:
src_ia = self.addr.isd_as
thread = threading.current_thread()
thread.name = "SCIONDaemon API id:%s %s -> %s" % (
thread.ident, src_ia, dst_ia)
paths, error = self.get_paths(dst_ia, flush=request.p.flags.refresh)
if request.p.maxPaths:
paths = paths[:request.p.maxPaths]
reply_entries = []
for path_meta in paths:
fwd_if = path_meta.fwd_path().get_fwd_if()
# Set dummy host addr if path is empty.
haddr, port = None, None
if fwd_if:
br = self.ifid2br[fwd_if]
haddr, port = br.int_addrs.public[0]
addrs = [haddr] if haddr else []
first_hop = HostInfo.from_values(addrs, port)
reply_entry = SCIONDPathReplyEntry.from_values(
path_meta, first_hop)
reply_entries.append(reply_entry)
logging.debug("Replying to api request for %s with %d paths:\n%s",
dst_ia, len(paths), "\n".join([p.short_desc() for p in paths]))
self._send_path_reply(req_id, reply_entries, error, meta)
def _send_path_reply(self, req_id, reply_entries, error, meta):
path_reply = SCIONDMsg(SCIONDPathReply.from_values(reply_entries, error), req_id)
self.send_meta(path_reply.pack(), meta)
def _api_handle_as_request(self, pld, meta):
request = pld.union
assert isinstance(request, SCIONDASInfoRequest), type(request)
req_ia = request.isd_as()
if not req_ia or req_ia.is_zero() or req_ia == self.addr.isd_as:
# Request is for the local AS.
reply_entry = SCIONDASInfoReplyEntry.from_values(
self.addr.isd_as, self.is_core_as(), self.topology.mtu)
else:
# Request is for a remote AS.
reply_entry = SCIONDASInfoReplyEntry.from_values(req_ia, self.is_core_as(req_ia))
as_reply = SCIONDMsg(SCIONDASInfoReply.from_values([reply_entry]), pld.id)
self.send_meta(as_reply.pack(), meta)
def _api_handle_if_request(self, pld, meta):
request = pld.union
assert isinstance(request, SCIONDIFInfoRequest), type(request)
all_brs = request.all_brs()
if_list = []
if not all_brs:
if_list = list(request.iter_ids())
if_entries = []
for if_id, br in self.ifid2br.items():
if all_brs or if_id in if_list:
br_addr, br_port = br.int_addrs.public[0]
info = HostInfo.from_values([br_addr], br_port)
reply_entry = SCIONDIFInfoReplyEntry.from_values(if_id, info)
if_entries.append(reply_entry)
if_reply = SCIONDMsg(SCIONDIFInfoReply.from_values(if_entries), pld.id)
self.send_meta(if_reply.pack(), meta)
def _api_handle_service_request(self, pld, meta):
request = pld.union
assert isinstance(request, SCIONDServiceInfoRequest), type(request)
all_svcs = request.all_services()
svc_list = []
if not all_svcs:
svc_list = list(request.iter_service_types())
svc_entries = []
for svc_type in ServiceType.all():
if all_svcs or svc_type in svc_list:
lookup_res = self.dns_query_topo(svc_type)
host_infos = []
for addr, port in lookup_res:
host_infos.append(HostInfo.from_values([addr], port))
reply_entry = SCIONDServiceInfoReplyEntry.from_values(
svc_type, host_infos)
svc_entries.append(reply_entry)
svc_reply = SCIONDMsg(SCIONDServiceInfoReply.from_values(svc_entries), pld.id)
self.send_meta(svc_reply.pack(), meta)
def _api_handle_rev_notification(self, pld, meta):
request = pld.union
assert isinstance(request, SCIONDRevNotification), type(request)
self.handle_revocation(CtrlPayload(PathMgmt(request.srev_info())), meta, pld)
def _api_handle_seg_type_request(self, pld, meta):
request = pld.union
assert isinstance(request, SCIONDSegTypeHopRequest), type(request)
segmentType = request.p.type
db = []
if segmentType == PST.CORE:
db = self.core_segments
elif segmentType == PST.UP:
db = self.up_segments
elif segmentType == PST.DOWN:
db = self.down_segments
else:
logging.error("Requesting segment type %s unrecognized.", segmentType)
seg_entries = []
for segment in db(full=True):
if_list = []
for asm in segment.iter_asms():
isd_as = asm.isd_as()
hof = asm.pcbm(0).hof()
egress = hof.egress_if
ingress = hof.ingress_if
if ingress:
if_list.append(PathInterface.from_values(isd_as, ingress))
if egress:
if_list.append(PathInterface.from_values(isd_as, egress))
reply_entry = SCIONDSegTypeHopReplyEntry.from_values(
if_list, segment.get_timestamp(), segment.get_expiration_time())
seg_entries.append(reply_entry)
seg_reply = SCIONDMsg(
SCIONDSegTypeHopReply.from_values(seg_entries), pld.id)
self.send_meta(seg_reply.pack(), meta)
def handle_scmp_revocation(self, pld, meta):
srev_info = SignedRevInfo.from_raw(pld.info.srev_info)
self.handle_revocation(CtrlPayload(PathMgmt(srev_info)), meta)
def handle_revocation(self, cpld, meta, pld=None):
pmgt = cpld.union
srev_info = pmgt.union
rev_info = srev_info.rev_info()
assert isinstance(rev_info, RevocationInfo), type(rev_info)
logging.debug("Received revocation: %s from %s", srev_info.short_desc(), meta)
self.check_revocation(srev_info,
lambda e: self.process_revocation(e, srev_info, meta, pld), meta)
def process_revocation(self, error, srev_info, meta, pld):
rev_info = srev_info.rev_info()
status = None
if error is None:
status = SCIONDRevReplyStatus.VALID
self.rev_cache.add(srev_info)
self.remove_revoked_segments(rev_info)
else:
if type(error) == RevInfoValidationError:
logging.error("Failed to validate RevInfo %s from %s: %s",
srev_info.short_desc(), meta, error)
status = SCIONDRevReplyStatus.INVALID
if type(error) == RevInfoExpiredError:
logging.info("Ignoring expired Revinfo, %s from %s", srev_info.short_desc(), meta)
status = SCIONDRevReplyStatus.STALE
if type(error) == SignedRevInfoCertFetchError:
logging.error("Failed to fetch certificate for SignedRevInfo %s from %s: %s",
srev_info.short_desc(), meta, error)
status = SCIONDRevReplyStatus.UNKNOWN
if type(error) == SignedRevInfoVerificationError:
logging.error("Failed to verify SRevInfo %s from %s: %s",
srev_info.short_desc(), meta, error)
status = SCIONDRevReplyStatus.SIGFAIL
if type(error) == SCIONBaseError:
logging.error("Revocation check failed for %s from %s:\n%s",
srev_info.short_desc(), meta, error)
status = SCIONDRevReplyStatus.UNKNOWN
if pld:
rev_reply = SCIONDMsg(SCIONDRevReply.from_values(status), pld.id)
self.send_meta(rev_reply.pack(), meta)
def remove_revoked_segments(self, rev_info):
# Go through all segment databases and remove affected segments.
removed_up = removed_core = removed_down = 0
if rev_info.p.linkType == LinkType.CORE:
removed_core = self._remove_revoked_pcbs(self.core_segments, rev_info)
elif rev_info.p.linkType in [LinkType.PARENT, LinkType.CHILD]:
removed_up = self._remove_revoked_pcbs(self.up_segments, rev_info)
removed_down = self._remove_revoked_pcbs(self.down_segments, rev_info)
elif rev_info.p.linkType != LinkType.PEER:
logging.error("Bad RevInfo link type: %s", rev_info.p.linkType)
logging.info("Removed %d UP- %d CORE- and %d DOWN-Segments." %
(removed_up, removed_core, removed_down))
def _remove_revoked_pcbs(self, db, rev_info):
"""
Removes all segments from 'db' that have a revoked upstream PCBMarking.
:param db: The PathSegmentDB.
:type db: :class:`lib.path_db.PathSegmentDB`
:param rev_info: The revocation info
:type rev_info: RevocationInfo
:returns: The number of deletions.
:rtype: int
"""
to_remove = []
for segment in db(full=True):
for asm in segment.iter_asms():
if self._check_revocation_for_asm(rev_info, asm, verify_all=False):
logging.debug("Removing segment: %s" % segment.short_desc())
to_remove.append(segment.get_hops_hash())
return db.delete_all(to_remove)
def _flush_path_dbs(self):
self.core_segments.flush()
self.down_segments.flush()
self.up_segments.flush()
def get_paths(self, dst_ia, flags=(), flush=False):
"""Return a list of paths."""
logging.debug("Paths requested for ISDAS=%s, flags=%s, flush=%s",
dst_ia, flags, flush)
if flush:
logging.info("Flushing PathDBs.")
self._flush_path_dbs()
if self.addr.isd_as == dst_ia or (
self.addr.isd_as.any_as() == dst_ia and
self.topology.is_core_as):
# Either the destination is the local AS, or the destination is any
# core AS in this ISD, and the local AS is in the core
empty = SCIONPath()
exp_time = int(time.time()) + self.EMPTY_PATH_TTL
empty_meta = FwdPathMeta.from_values(empty, [], self.topology.mtu, exp_time)
return [empty_meta], SCIONDPathReplyError.OK
paths = self.path_resolution(dst_ia, flags=flags)
if not paths:
key = dst_ia, flags
with self.req_path_lock:
r = self.requested_paths.get(key)
if r is None:
# No previous outstanding request
req = PathSegmentReq.from_values(self.addr.isd_as, dst_ia, flags=flags)
r = RequestState(req.copy())
self.requested_paths[key] = r
self._fetch_segments(req)
# Wait until event gets set.
timeout = not r.e.wait(PATH_REQ_TOUT)
with self.req_path_lock:
if timeout:
r.done()
if key in self.requested_paths:
del self.requested_paths[key]
if timeout:
logging.error("Query timed out for %s", dst_ia)
return [], SCIONDPathReplyError.PS_TIMEOUT
# Check if we can fulfill the path request.
paths = self.path_resolution(dst_ia, flags=flags)
if not paths:
logging.error("No paths found for %s", dst_ia)
return [], SCIONDPathReplyError.NO_PATHS
return paths, SCIONDPathReplyError.OK
def path_resolution(self, dst_ia, flags=()):
# dst as == 0 means any core AS in the specified ISD.
dst_is_core = self.is_core_as(dst_ia) or dst_ia[1] == 0
sibra = PATH_FLAG_SIBRA in flags
if self.topology.is_core_as:
if dst_is_core:
ret = self._resolve_core_core(dst_ia, sibra=sibra)
else:
ret = self._resolve_core_not_core(dst_ia, sibra=sibra)
elif dst_is_core:
ret = self._resolve_not_core_core(dst_ia, sibra=sibra)
elif sibra:
ret = self._resolve_not_core_not_core_sibra(dst_ia)
else:
ret = self._resolve_not_core_not_core_scion(dst_ia)
if not sibra:
return ret
# FIXME(kormat): Strip off PCBs, and just return sibra reservation
# blocks
return self._sibra_strip_pcbs(self._strip_nones(ret))
def _resolve_core_core(self, dst_ia, sibra=False):
"""Resolve path from core to core."""
res = set()
for cseg in self.core_segments(last_ia=self.addr.isd_as, sibra=sibra,
**dst_ia.params()):
res.add((None, cseg, None))
if sibra:
return res
return tuples_to_full_paths(res)
def _resolve_core_not_core(self, dst_ia, sibra=False):
"""Resolve path from core to non-core."""
res = set()
# First check whether there is a direct path.
for dseg in self.down_segments(
first_ia=self.addr.isd_as, last_ia=dst_ia, sibra=sibra):
res.add((None, None, dseg))
# Check core-down combination.
for dseg in self.down_segments(last_ia=dst_ia, sibra=sibra):
dseg_ia = dseg.first_ia()
if self.addr.isd_as == dseg_ia:
pass
for cseg in self.core_segments(
first_ia=dseg_ia, last_ia=self.addr.isd_as, sibra=sibra):
res.add((None, cseg, dseg))
if sibra:
return res
return tuples_to_full_paths(res)
def _resolve_not_core_core(self, dst_ia, sibra=False):
"""Resolve path from non-core to core."""
res = set()
params = dst_ia.params()
params["sibra"] = sibra
if dst_ia[0] == self.addr.isd_as[0]:
# Dst in local ISD. First check whether DST is a (super)-parent.
for useg in self.up_segments(**params):
res.add((useg, None, None))
# Check whether dst is known core AS.
for cseg in self.core_segments(**params):
# Check do we have an up-seg that is connected to core_seg.
for useg in self.up_segments(first_ia=cseg.last_ia(), sibra=sibra):
res.add((useg, cseg, None))
if sibra:
return res
return tuples_to_full_paths(res)
def _resolve_not_core_not_core_scion(self, dst_ia):
"""Resolve SCION path from non-core to non-core."""
up_segs = self.up_segments()
down_segs = self.down_segments(last_ia=dst_ia)
core_segs = self._calc_core_segs(dst_ia[0], up_segs, down_segs)
full_paths = build_shortcut_paths(
up_segs, down_segs, self.rev_cache)
tuples = []
for up_seg in up_segs:
for down_seg in down_segs:
tuples.append((up_seg, None, down_seg))
for core_seg in core_segs:
tuples.append((up_seg, core_seg, down_seg))
full_paths.extend(tuples_to_full_paths(tuples))
return full_paths
def _resolve_not_core_not_core_sibra(self, dst_ia):
"""Resolve SIBRA path from non-core to non-core."""
res = set()
up_segs = set(self.up_segments(sibra=True))
down_segs = set(self.down_segments(last_ia=dst_ia, sibra=True))
for up_seg, down_seg in product(up_segs, down_segs):
src_core_ia = up_seg.first_ia()
dst_core_ia = down_seg.first_ia()
if src_core_ia == dst_core_ia:
res.add((up_seg, down_seg))
continue
for core_seg in self.core_segments(first_ia=dst_core_ia,
last_ia=src_core_ia, sibra=True):
res.add((up_seg, core_seg, down_seg))
return res
def _strip_nones(self, set_):
"""Strip None entries from a set of tuples"""
res = []
for tup in set_:
res.append(tuple(filter(None, tup)))
return res
def _sibra_strip_pcbs(self, paths):
ret = []
for pcbs in paths:
resvs = []
for pcb in pcbs:
resvs.append(self._sibra_strip_pcb(pcb))
ret.append(resvs)
return ret
def _sibra_strip_pcb(self, pcb):
assert pcb.is_sibra()
pcb_ext = pcb.sibra_ext
resv_info = pcb_ext.info
resv = ResvBlockSteady.from_values(resv_info, pcb.get_n_hops())
asms = pcb.iter_asms()
if pcb_ext.p.up:
asms = reversed(list(asms))
iflist = []
for sof, asm in zip(pcb_ext.iter_sofs(), asms):
resv.sofs.append(sof)
iflist.extend(self._sibra_add_ifs(
asm.isd_as(), sof, resv_info.fwd_dir))
assert resv.num_hops == len(resv.sofs)
return pcb_ext.p.id, resv, iflist
def _sibra_add_ifs(self, isd_as, sof, fwd):
def _add(ifid):
if ifid:
ret.append((isd_as, ifid))
ret = []
if fwd:
_add(sof.ingress)
_add(sof.egress)
else:
_add(sof.egress)
_add(sof.ingress)
return ret
def _wait_for_events(self, events, deadline):
"""
Wait on a set of events, but only until the specified deadline. Returns
the number of events that happened while waiting.
"""
count = 0
for e in events:
if e.wait(max(0, deadline - SCIONTime.get_time())):
count += 1
return count
def _fetch_segments(self, req):
"""
Called to fetch the requested path.
"""
try:
addr, port = self.dns_query_topo(ServiceType.PS)[0]
except SCIONServiceLookupError:
log_exception("Error querying path service:")
return
req_id = mk_ctrl_req_id()
logging.debug("Sending path request (%s) to [%s]:%s [id: %016x]",
req.short_desc(), addr, port, req_id)
meta = self._build_meta(host=addr, port=port)
self.send_meta(CtrlPayload(PathMgmt(req), req_id=req_id), meta)
def _calc_core_segs(self, dst_isd, up_segs, down_segs):
"""
Calculate all possible core segments joining the provided up and down
segments. Returns a list of all known segments, and a seperate list of
the missing AS pairs.
"""
src_core_ases = set()
dst_core_ases = set()
for seg in up_segs:
src_core_ases.add(seg.first_ia()[1])
for seg in down_segs:
dst_core_ases.add(seg.first_ia()[1])
# Generate all possible AS pairs
as_pairs = list(product(src_core_ases, dst_core_ases))
return self._find_core_segs(self.addr.isd_as[0], dst_isd, as_pairs)
def _find_core_segs(self, src_isd, dst_isd, as_pairs):
"""
Given a set of AS pairs across 2 ISDs, return the core segments
connecting those pairs
"""
core_segs = []
for src_core_as, dst_core_as in as_pairs:
src_ia = ISD_AS.from_values(src_isd, src_core_as)
dst_ia = ISD_AS.from_values(dst_isd, dst_core_as)
if src_ia == dst_ia:
continue
seg = self.core_segments(first_ia=dst_ia, last_ia=src_ia)
if seg:
core_segs.extend(seg)
return core_segs
def run(self):
"""
Run an instance of the SCION daemon.
"""
threading.Thread(
target=thread_safety_net, args=(self._check_trc_cert_reqs,),
name="Elem.check_trc_cert_reqs", daemon=True).start()
super().run()
class SCIONDaemon(SCIONElement):
"""
The SCION Daemon used for retrieving and combining paths.
"""
# Max time for a path lookup to succeed/fail.
PATH_REQ_TOUT = 2
MAX_REQS = 1024
# Time a path segment is cached at a host (in seconds).
SEGMENT_TTL = 300
def __init__(self,
conf_dir,
addr,
api_addr,
run_local_api=False,
port=None):
"""
Initialize an instance of the class SCIONDaemon.
"""
super().__init__("sciond", conf_dir, host_addr=addr, port=port)
# TODO replace by pathstore instance
self.up_segments = PathSegmentDB(segment_ttl=self.SEGMENT_TTL)
self.down_segments = PathSegmentDB(segment_ttl=self.SEGMENT_TTL)
self.core_segments = PathSegmentDB(segment_ttl=self.SEGMENT_TTL)
self.peer_revs = RevCache()
# Keep track of requested paths.
self.requested_paths = ExpiringDict(self.MAX_REQS, self.PATH_REQ_TOUT)
self.req_path_lock = threading.Lock()
self._api_sock = None
self.daemon_thread = None
os.makedirs(SCIOND_API_SOCKDIR, exist_ok=True)
self.api_addr = (api_addr or os.path.join(
SCIOND_API_SOCKDIR, "%s.sock" % self.addr.isd_as))
self.CTRL_PLD_CLASS_MAP = {
PayloadClass.PATH: {
PMT.REPLY: self.handle_path_reply,
PMT.REVOCATION: self.handle_revocation,
},
PayloadClass.CERT: {
CertMgmtType.CERT_CHAIN_REQ: self.process_cert_chain_request,
CertMgmtType.CERT_CHAIN_REPLY: self.process_cert_chain_reply,
CertMgmtType.TRC_REPLY: self.process_trc_reply,
CertMgmtType.TRC_REQ: self.process_trc_request,
},
}
self.SCMP_PLD_CLASS_MAP = {
SCMPClass.PATH: {
SCMPPathClass.REVOKED_IF: self.handle_scmp_revocation
},
}
if run_local_api:
self._api_sock = ReliableSocket(bind=(self.api_addr, "sciond"))
self._socks.add(self._api_sock, self.handle_accept)
@classmethod
def start(cls, conf_dir, addr, api_addr=None, run_local_api=False, port=0):
"""
Initializes, starts, and returns a SCIONDaemon object.
Example of usage:
sd = SCIONDaemon.start(conf_dir, addr)
paths = sd.get_paths(isd_as)
"""
inst = cls(conf_dir, addr, api_addr, run_local_api, port)
name = "SCIONDaemon.run %s" % inst.addr.isd_as
inst.daemon_thread = threading.Thread(target=thread_safety_net,
args=(inst.run, ),
name=name,
daemon=True)
inst.daemon_thread.start()
logging.debug("sciond started with api_addr = %s", inst.api_addr)
return inst
def _get_msg_meta(self, packet, addr, sock):
if sock != self._udp_sock:
return packet, SockOnlyMetadata.from_values(sock) # API socket
else:
return super()._get_msg_meta(packet, addr, sock)
def handle_msg_meta(self, msg, meta):
"""
Main routine to handle incoming SCION messages.
"""
if isinstance(meta, SockOnlyMetadata): # From SCIOND API
try:
sciond_msg = parse_sciond_msg(msg)
except SCIONParseError as err:
logging.error(str(err))
return
self.api_handle_request(sciond_msg, meta)
return
super().handle_msg_meta(msg, meta)
def handle_path_reply(self, path_reply, meta):
"""
Handle path reply from local path server.
"""
for rev_info in path_reply.iter_rev_infos():
self.peer_revs.add(rev_info)
for type_, pcb in path_reply.iter_pcbs():
seg_meta = PathSegMeta(pcb, self.continue_seg_processing, meta,
type_)
self.process_path_seg(seg_meta)
def continue_seg_processing(self, seg_meta):
"""
For every path segment(that can be verified) received from the path
server this function gets called to continue the processing for the
segment.
The segment is added to pathdb and pending requests are checked.
"""
pcb = seg_meta.seg
type_ = seg_meta.type
map_ = {
PST.UP: self._handle_up_seg,
PST.DOWN: self._handle_down_seg,
PST.CORE: self._handle_core_seg,
}
ret = map_[type_](pcb)
if not ret:
return
with self.req_path_lock:
# .items() makes a copy on an expiring dict, so deleting entries is safe.
for key, e in self.requested_paths.items():
if self.path_resolution(*key):
e.set()
del self.requested_paths[key]
def _handle_up_seg(self, pcb):
if self.addr.isd_as != pcb.last_ia():
return None
if self.up_segments.update(pcb) == DBResult.ENTRY_ADDED:
logging.debug("Up segment added: %s", pcb.short_desc())
return pcb.first_ia()
return None
def _handle_down_seg(self, pcb):
last_ia = pcb.last_ia()
if self.addr.isd_as == last_ia:
return None
if self.down_segments.update(pcb) == DBResult.ENTRY_ADDED:
logging.debug("Down segment added: %s", pcb.short_desc())
return last_ia
return None
def _handle_core_seg(self, pcb):
if self.core_segments.update(pcb) == DBResult.ENTRY_ADDED:
logging.debug("Core segment added: %s", pcb.short_desc())
return pcb.first_ia()
return None
def api_handle_request(self, msg, meta):
"""
Handle local API's requests.
"""
if msg.MSG_TYPE == SMT.PATH_REQUEST:
threading.Thread(target=thread_safety_net,
args=(self._api_handle_path_request, msg, meta),
daemon=True).start()
elif msg.MSG_TYPE == SMT.REVOCATION:
self.handle_revocation(msg.rev_info(), meta)
elif msg.MSG_TYPE == SMT.AS_REQUEST:
self._api_handle_as_request(msg, meta)
elif msg.MSG_TYPE == SMT.IF_REQUEST:
self._api_handle_if_request(msg, meta)
elif msg.MSG_TYPE == SMT.SERVICE_REQUEST:
self._api_handle_service_request(msg, meta)
else:
logging.warning("API: type %s not supported.",
TypeBase.to_str(msg.MSG_TYPE))
def _api_handle_path_request(self, request, meta):
req_id = request.id
if request.p.flags.sibra:
logging.warning(
"Requesting SIBRA paths over SCIOND API not supported yet.")
self._send_path_reply(req_id, [], SCIONDPathReplyError.INTERNAL,
meta)
return
dst_ia = request.dst_ia()
src_ia = request.src_ia()
if not src_ia:
src_ia = self.addr.isd_as
thread = threading.current_thread()
thread.name = "SCIONDaemon API id:%s %s -> %s" % (thread.ident, src_ia,
dst_ia)
paths, error = self.get_paths(dst_ia, flush=request.p.flags.flush)
if request.p.maxPaths:
paths = paths[:request.p.maxPaths]
logging.debug("Replying to api request for %s with %d paths", dst_ia,
len(paths))
reply_entries = []
for path_meta in paths:
fwd_if = path_meta.fwd_path().get_fwd_if()
# Set dummy host addr if path is empty.
haddr, port = None, None
if fwd_if:
br = self.ifid2br[fwd_if]
haddr, port = br.addr, br.port
addrs = [haddr] if haddr else []
first_hop = HostInfo.from_values(addrs, port)
reply_entry = SCIONDPathReplyEntry.from_values(
path_meta, first_hop)
reply_entries.append(reply_entry)
self._send_path_reply(req_id, reply_entries, error, meta)
def _send_path_reply(self, req_id, reply_entries, error, meta):
path_reply = SCIONDPathReply.from_values(req_id, reply_entries, error)
self.send_meta(path_reply.pack_full(), meta)
def _api_handle_as_request(self, request, meta):
remote_as = request.isd_as()
if remote_as:
reply_entry = SCIONDASInfoReplyEntry.from_values(
remote_as, self.is_core_as(remote_as))
else:
reply_entry = SCIONDASInfoReplyEntry.from_values(
self.addr.isd_as, self.is_core_as(), self.topology.mtu)
as_reply = SCIONDASInfoReply.from_values(request.id, [reply_entry])
self.send_meta(as_reply.pack_full(), meta)
def _api_handle_if_request(self, request, meta):
all_brs = request.all_brs()
if_list = []
if not all_brs:
if_list = list(request.iter_ids())
if_entries = []
for if_id, br in self.ifid2br.items():
if all_brs or if_id in if_list:
info = HostInfo.from_values([br.addr], br.port)
reply_entry = SCIONDIFInfoReplyEntry.from_values(if_id, info)
if_entries.append(reply_entry)
if_reply = SCIONDIFInfoReply.from_values(request.id, if_entries)
self.send_meta(if_reply.pack_full(), meta)
def _api_handle_service_request(self, request, meta):
all_svcs = request.all_services()
svc_list = []
if not all_svcs:
svc_list = list(request.iter_service_types())
svc_entries = []
for svc_type in ServiceType.all():
if all_svcs or svc_type in svc_list:
lookup_res = self.dns_query_topo(svc_type)
host_infos = []
for addr, port in lookup_res:
host_infos.append(HostInfo.from_values([addr], port))
reply_entry = SCIONDServiceInfoReplyEntry.from_values(
svc_type, host_infos)
svc_entries.append(reply_entry)
svc_reply = SCIONDServiceInfoReply.from_values(request.id, svc_entries)
self.send_meta(svc_reply.pack_full(), meta)
def handle_scmp_revocation(self, pld, meta):
rev_info = RevocationInfo.from_raw(pld.info.rev_info)
self.handle_revocation(rev_info, meta)
def handle_revocation(self, rev_info, meta):
assert isinstance(rev_info, RevocationInfo)
if not self._validate_revocation(rev_info):
return
# Go through all segment databases and remove affected segments.
removed_up = self._remove_revoked_pcbs(self.up_segments, rev_info)
removed_core = self._remove_revoked_pcbs(self.core_segments, rev_info)
removed_down = self._remove_revoked_pcbs(self.down_segments, rev_info)
logging.info("Removed %d UP- %d CORE- and %d DOWN-Segments." %
(removed_up, removed_core, removed_down))
def _remove_revoked_pcbs(self, db, rev_info):
"""
Removes all segments from 'db' that contain an IF token for which
rev_token is a preimage (within 20 calls).
:param db: The PathSegmentDB.
:type db: :class:`lib.path_db.PathSegmentDB`
:param rev_info: The revocation info
:type rev_info: RevocationInfo
:returns: The number of deletions.
:rtype: int
"""
if not ConnectedHashTree.verify_epoch(rev_info.p.epoch):
logging.debug(
"Failed to verify epoch: rev_info epoch %d,current epoch %d." %
(rev_info.p.epoch, ConnectedHashTree.get_current_epoch()))
return 0
to_remove = []
for segment in db(full=True):
for asm in segment.iter_asms():
if self._verify_revocation_for_asm(rev_info, asm):
logging.debug("Removing segment: %s" %
segment.short_desc())
to_remove.append(segment.get_hops_hash())
return db.delete_all(to_remove)
def _flush_path_dbs(self):
self.core_segments.flush()
self.down_segments.flush()
self.up_segments.flush()
def get_paths(self, dst_ia, flags=(), flush=False):
"""Return a list of paths."""
logging.debug("Paths requested for ISDAS=%s, flags=%s, flush=%s",
dst_ia, flags, flush)
if flush:
logging.info("Flushing PathDBs.")
self._flush_path_dbs()
if self.addr.isd_as == dst_ia or (self.addr.isd_as.any_as() == dst_ia
and self.topology.is_core_as):
# Either the destination is the local AS, or the destination is any
# core AS in this ISD, and the local AS is in the core
empty = SCIONPath()
empty_meta = FwdPathMeta.from_values(empty, [], self.topology.mtu)
return [empty_meta], SCIONDPathReplyError.OK
paths = self.path_resolution(dst_ia, flags=flags)
if not paths:
key = dst_ia, flags
with self.req_path_lock:
if key not in self.requested_paths:
# No previous outstanding request
self.requested_paths[key] = threading.Event()
self._fetch_segments(key)
e = self.requested_paths[key]
if not e.wait(self.PATH_REQ_TOUT):
logging.error("Query timed out for %s", dst_ia)
return [], SCIONDPathReplyError.PS_TIMEOUT
paths = self.path_resolution(dst_ia, flags=flags)
error_code = (SCIONDPathReplyError.OK
if paths else SCIONDPathReplyError.NO_PATHS)
return paths, error_code
def path_resolution(self, dst_ia, flags=()):
# dst as == 0 means any core AS in the specified ISD.
dst_is_core = self.is_core_as(dst_ia) or dst_ia[1] == 0
sibra = PATH_FLAG_SIBRA in flags
if self.topology.is_core_as:
if dst_is_core:
ret = self._resolve_core_core(dst_ia, sibra=sibra)
else:
ret = self._resolve_core_not_core(dst_ia, sibra=sibra)
elif dst_is_core:
ret = self._resolve_not_core_core(dst_ia, sibra=sibra)
elif sibra:
ret = self._resolve_not_core_not_core_sibra(dst_ia)
else:
ret = self._resolve_not_core_not_core_scion(dst_ia)
if not sibra:
return ret
# FIXME(kormat): Strip off PCBs, and just return sibra reservation
# blocks
return self._sibra_strip_pcbs(self._strip_nones(ret))
def _resolve_core_core(self, dst_ia, sibra=False):
"""Resolve path from core to core."""
res = set()
for cseg in self.core_segments(last_ia=self.addr.isd_as,
sibra=sibra,
**dst_ia.params()):
res.add((None, cseg, None))
if sibra:
return res
return tuples_to_full_paths(res)
def _resolve_core_not_core(self, dst_ia, sibra=False):
"""Resolve path from core to non-core."""
res = set()
# First check whether there is a direct path.
for dseg in self.down_segments(first_ia=self.addr.isd_as,
last_ia=dst_ia,
sibra=sibra):
res.add((None, None, dseg))
# Check core-down combination.
for dseg in self.down_segments(last_ia=dst_ia, sibra=sibra):
dseg_ia = dseg.first_ia()
if self.addr.isd_as == dseg_ia:
pass
for cseg in self.core_segments(first_ia=dseg_ia,
last_ia=self.addr.isd_as,
sibra=sibra):
res.add((None, cseg, dseg))
if sibra:
return res
return tuples_to_full_paths(res)
def _resolve_not_core_core(self, dst_ia, sibra=False):
"""Resolve path from non-core to core."""
res = set()
params = dst_ia.params()
params["sibra"] = sibra
if dst_ia[0] == self.addr.isd_as[0]:
# Dst in local ISD. First check whether DST is a (super)-parent.
for useg in self.up_segments(**params):
res.add((useg, None, None))
# Check whether dst is known core AS.
for cseg in self.core_segments(**params):
# Check do we have an up-seg that is connected to core_seg.
for useg in self.up_segments(first_ia=cseg.last_ia(), sibra=sibra):
res.add((useg, cseg, None))
if sibra:
return res
return tuples_to_full_paths(res)
def _resolve_not_core_not_core_scion(self, dst_ia):
"""Resolve SCION path from non-core to non-core."""
up_segs = self.up_segments()
down_segs = self.down_segments(last_ia=dst_ia)
core_segs = self._calc_core_segs(dst_ia[0], up_segs, down_segs)
full_paths = build_shortcut_paths(up_segs, down_segs, self.peer_revs)
tuples = []
for up_seg in up_segs:
for down_seg in down_segs:
tuples.append((up_seg, None, down_seg))
for core_seg in core_segs:
tuples.append((up_seg, core_seg, down_seg))
full_paths.extend(tuples_to_full_paths(tuples))
return full_paths
def _resolve_not_core_not_core_sibra(self, dst_ia):
"""Resolve SIBRA path from non-core to non-core."""
res = set()
up_segs = set(self.up_segments(sibra=True))
down_segs = set(self.down_segments(last_ia=dst_ia, sibra=True))
for up_seg, down_seg in product(up_segs, down_segs):
src_core_ia = up_seg.first_ia()
dst_core_ia = down_seg.first_ia()
if src_core_ia == dst_core_ia:
res.add((up_seg, down_seg))
continue
for core_seg in self.core_segments(first_ia=dst_core_ia,
last_ia=src_core_ia,
sibra=True):
res.add((up_seg, core_seg, down_seg))
return res
def _strip_nones(self, set_):
"""Strip None entries from a set of tuples"""
res = []
for tup in set_:
res.append(tuple(filter(None, tup)))
return res
def _sibra_strip_pcbs(self, paths):
ret = []
for pcbs in paths:
resvs = []
for pcb in pcbs:
resvs.append(self._sibra_strip_pcb(pcb))
ret.append(resvs)
return ret
def _sibra_strip_pcb(self, pcb):
assert pcb.is_sibra()
pcb_ext = pcb.sibra_ext
resv_info = pcb_ext.info
resv = ResvBlockSteady.from_values(resv_info, pcb.get_n_hops())
asms = pcb.iter_asms()
if pcb_ext.p.up:
asms = reversed(list(asms))
iflist = []
for sof, asm in zip(pcb_ext.iter_sofs(), asms):
resv.sofs.append(sof)
iflist.extend(
self._sibra_add_ifs(asm.isd_as(), sof, resv_info.fwd_dir))
assert resv.num_hops == len(resv.sofs)
return pcb_ext.p.id, resv, iflist
def _sibra_add_ifs(self, isd_as, sof, fwd):
def _add(ifid):
if ifid:
ret.append((isd_as, ifid))
ret = []
if fwd:
_add(sof.ingress)
_add(sof.egress)
else:
_add(sof.egress)
_add(sof.ingress)
return ret
def _wait_for_events(self, events, deadline):
"""
Wait on a set of events, but only until the specified deadline. Returns
the number of events that happened while waiting.
"""
count = 0
for e in events:
if e.wait(max(0, deadline - SCIONTime.get_time())):
count += 1
return count
def _fetch_segments(self, key):
"""
Called to fetch the requested path.
"""
dst_ia, flags = key
try:
addr, port = self.dns_query_topo(PATH_SERVICE)[0]
except SCIONServiceLookupError:
log_exception("Error querying path service:")
return
req = PathSegmentReq.from_values(self.addr.isd_as, dst_ia, flags=flags)
logging.debug("Sending path request: %s", req.short_desc())
meta = self.DefaultMeta.from_values(host=addr, port=port)
self.send_meta(req, meta)
def _calc_core_segs(self, dst_isd, up_segs, down_segs):
"""
Calculate all possible core segments joining the provided up and down
segments. Returns a list of all known segments, and a seperate list of
the missing AS pairs.
"""
src_core_ases = set()
dst_core_ases = set()
for seg in up_segs:
src_core_ases.add(seg.first_ia()[1])
for seg in down_segs:
dst_core_ases.add(seg.first_ia()[1])
# Generate all possible AS pairs
as_pairs = list(product(src_core_ases, dst_core_ases))
return self._find_core_segs(self.addr.isd_as[0], dst_isd, as_pairs)
def _find_core_segs(self, src_isd, dst_isd, as_pairs):
"""
Given a set of AS pairs across 2 ISDs, return the core segments
connecting those pairs
"""
core_segs = []
for src_core_as, dst_core_as in as_pairs:
src_ia = ISD_AS.from_values(src_isd, src_core_as)
dst_ia = ISD_AS.from_values(dst_isd, dst_core_as)
if src_ia == dst_ia:
continue
seg = self.core_segments(first_ia=dst_ia, last_ia=src_ia)
if seg:
core_segs.extend(seg)
return core_segs
class SCIONDaemon(SCIONElement):
"""
The SCION Daemon used for retrieving and combining paths.
"""
# Max time for a path lookup to succeed/fail.
TIMEOUT = 5
# Time a path segment is cached at a host (in seconds).
SEGMENT_TTL = 300
MAX_SEG_NO = 5 # TODO: replace by config variable.
def __init__(self,
conf_dir,
addr,
api_addr,
run_local_api=False,
port=None):
"""
Initialize an instance of the class SCIONDaemon.
"""
super().__init__("sciond", conf_dir, host_addr=addr, port=port)
# TODO replace by pathstore instance
self.up_segments = PathSegmentDB(segment_ttl=self.SEGMENT_TTL,
max_res_no=self.MAX_SEG_NO)
self.down_segments = PathSegmentDB(segment_ttl=self.SEGMENT_TTL,
max_res_no=self.MAX_SEG_NO)
self.core_segments = PathSegmentDB(segment_ttl=self.SEGMENT_TTL,
max_res_no=self.MAX_SEG_NO)
req_name = "SCIONDaemon Requests %s" % self.addr.isd_as
self.requests = RequestHandler.start(
req_name,
self._check_segments,
self._fetch_segments,
self._reply_segments,
ttl=self.TIMEOUT,
key_map=self._req_key_map,
)
self._api_sock = None
self.daemon_thread = None
os.makedirs(SCIOND_API_SOCKDIR, exist_ok=True)
self.api_addr = (api_addr or os.path.join(
SCIOND_API_SOCKDIR, "%s.sock" % self.addr.isd_as))
self.CTRL_PLD_CLASS_MAP = {
PayloadClass.PATH: {
PMT.REPLY: self.handle_path_reply,
PMT.REVOCATION: self.handle_revocation,
}
}
self.SCMP_PLD_CLASS_MAP = {
SCMPClass.PATH: {
SCMPPathClass.REVOKED_IF: self.handle_scmp_revocation
},
}
if run_local_api:
self._api_sock = ReliableSocket(bind=(self.api_addr, "sciond"))
self._socks.add(self._api_sock, self.handle_accept)
@classmethod
def start(cls, conf_dir, addr, api_addr=None, run_local_api=False, port=0):
"""
Initializes, starts, and returns a SCIONDaemon object.
Example of usage:
sd = SCIONDaemon.start(conf_dir, addr)
paths = sd.get_paths(isd_as)
"""
inst = cls(conf_dir, addr, api_addr, run_local_api, port)
name = "SCIONDaemon.run %s" % inst.addr.isd_as
inst.daemon_thread = threading.Thread(target=thread_safety_net,
args=(inst.run, ),
name=name,
daemon=True)
inst.daemon_thread.start()
logging.debug("sciond started with api_addr = %s", inst.api_addr)
return inst
def _get_msg_meta(self, packet, addr, sock):
if sock != self._udp_sock:
return packet, SockOnlyMetadata.from_values(sock) # API socket
else:
return super()._get_msg_meta(packet, addr, sock)
def handle_msg_meta(self, msg, meta):
"""
Main routine to handle incoming SCION messages.
"""
if isinstance(meta, SockOnlyMetadata): # From SCIOND API
self.api_handle_request(msg, meta)
return
logging.debug("handle_msg_meta()")
super().handle_msg_meta(msg, meta)
def handle_path_reply(self, path_reply, meta):
"""
Handle path reply from local path server.
"""
added = set()
map_ = {
PST.UP: self._handle_up_seg,
PST.DOWN: self._handle_down_seg,
PST.CORE: self._handle_core_seg,
}
for type_, pcb in path_reply.iter_pcbs():
ret = map_[type_](pcb)
if not ret:
continue
flags = (PATH_FLAG_SIBRA, ) if pcb.is_sibra() else ()
added.add((ret, flags))
logging.debug("Added: %s", added)
for dst_ia, flags in added:
self.requests.put(((dst_ia, flags), None))
logging.debug("Closing meta")
meta.close()
def _handle_up_seg(self, pcb):
if self.addr.isd_as != pcb.last_ia():
return None
if self.up_segments.update(pcb) == DBResult.ENTRY_ADDED:
logging.debug("Up segment added: %s", pcb.short_desc())
return pcb.first_ia()
return None
def _handle_down_seg(self, pcb):
last_ia = pcb.last_ia()
if self.addr.isd_as == last_ia:
return None
if self.down_segments.update(pcb) == DBResult.ENTRY_ADDED:
logging.debug("Down segment added: %s", pcb.short_desc())
return last_ia
return None
def _handle_core_seg(self, pcb):
if self.core_segments.update(pcb) == DBResult.ENTRY_ADDED:
logging.debug("Core segment added: %s", pcb.short_desc())
return pcb.first_ia()
return None
def api_handle_request(self, msg, meta):
"""
Handle local API's requests.
"""
if msg[0] == 0: # path request
logging.debug('API: path request')
threading.Thread(target=thread_safety_net,
args=(self._api_handle_path_request, msg, meta),
daemon=True).start()
elif msg[0] == 1: # address request
logging.debug('API: local ISD-AS request')
self.send_meta(self.addr.isd_as.pack(), meta)
else:
logging.warning("API: type %d not supported.", msg[0])
def _api_handle_path_request(self, msg, meta):
"""
Path request:
| \x00 (1B) | ISD (12bits) | AS (20bits) |
Reply:
|p1_len(1B)|p1((p1_len*8)B)|fh_type(1B)|fh_IP(?B)|fh_port(2B)|mtu(2B)|
p1_if_count(1B)|p1_if_1(5B)|...|p1_if_n(5B)|
p2_len(1B)|...
or b"" when no path found.
"""
dst_ia = ISD_AS(msg[1:ISD_AS.LEN + 1])
thread = threading.current_thread()
thread.name = "SCIONDaemon API id:%s %s -> %s" % (
thread.ident, self.addr.isd_as, dst_ia)
paths = self.get_paths(dst_ia)
reply = []
logging.debug("Replying to api request for %s with %d paths", dst_ia,
len(paths))
for path in paths:
raw_path = path.pack()
fwd_if = path.get_fwd_if()
# Set dummy host addr if path is empty.
if fwd_if == 0:
haddr, port = HostAddrNone(), SCION_UDP_EH_DATA_PORT
else:
br = self.ifid2br[fwd_if]
haddr, port = br.addr, br.port
path_len = len(raw_path) // 8
reply.append(
struct.pack("!B", path_len) + raw_path +
struct.pack("!B", haddr.TYPE) + haddr.pack() +
struct.pack("!H", port) + struct.pack("!H", path.mtu) +
struct.pack("!B", len(path.interfaces)))
for interface in path.interfaces:
isd_as, link = interface
reply.append(isd_as.pack())
reply.append(struct.pack("!H", link))
self.send_meta(b"".join(reply), meta)
def handle_scmp_revocation(self, pld, meta):
rev_info = RevocationInfo.from_raw(pld.info.rev_info)
self.handle_revocation(rev_info, meta)
def handle_revocation(self, rev_info, meta):
assert isinstance(rev_info, RevocationInfo)
if not self._validate_revocation(rev_info):
return
# Go through all segment databases and remove affected segments.
removed_up = self._remove_revoked_pcbs(self.up_segments, rev_info)
removed_core = self._remove_revoked_pcbs(self.core_segments, rev_info)
removed_down = self._remove_revoked_pcbs(self.down_segments, rev_info)
logging.info("Removed %d UP- %d CORE- and %d DOWN-Segments." %
(removed_up, removed_core, removed_down))
def _remove_revoked_pcbs(self, db, rev_info):
"""
Removes all segments from 'db' that contain an IF token for which
rev_token is a preimage (within 20 calls).
:param db: The PathSegmentDB.
:type db: :class:`lib.path_db.PathSegmentDB`
:param rev_info: The revocation info
:type rev_info: RevocationInfo
:returns: The number of deletions.
:rtype: int
"""
if not ConnectedHashTree.verify_epoch(rev_info.p.epoch):
logging.debug(
"Failed to verify epoch: rev_info epoch %d,current epoch %d." %
(rev_info.p.epoch, ConnectedHashTree.get_current_epoch()))
return 0
to_remove = []
for segment in db(full=True):
for asm in segment.iter_asms():
if self._verify_revocation_for_asm(rev_info, asm):
logging.debug("Removing segment: %s" %
segment.short_desc())
to_remove.append(segment.get_hops_hash())
return db.delete_all(to_remove)
def get_paths(self, dst_ia, flags=()):
"""Return a list of paths."""
logging.debug("Paths requested for %s %s", dst_ia, flags)
if self.addr.isd_as == dst_ia or (self.addr.isd_as.any_as() == dst_ia
and self.topology.is_core_as):
# Either the destination is the local AS, or the destination is any
# core AS in this ISD, and the local AS is in the core
empty = SCIONPath()
empty.mtu = self.topology.mtu
return [empty]
deadline = SCIONTime.get_time() + self.TIMEOUT
e = threading.Event()
self.requests.put(((dst_ia, flags), e))
if not self._wait_for_events([e], deadline):
logging.error("Query timed out for %s", dst_ia)
return []
return self.path_resolution(dst_ia, flags=flags)
def path_resolution(self, dst_ia, flags=()):
# dst as == 0 means any core AS in the specified ISD.
dst_is_core = self.is_core_as(dst_ia) or dst_ia[1] == 0
sibra = PATH_FLAG_SIBRA in flags
if self.topology.is_core_as:
if dst_is_core:
ret = self._resolve_core_core(dst_ia, sibra=sibra)
else:
ret = self._resolve_core_not_core(dst_ia, sibra=sibra)
elif dst_is_core:
ret = self._resolve_not_core_core(dst_ia, sibra=sibra)
elif sibra:
ret = self._resolve_not_core_not_core_sibra(dst_ia)
else:
ret = self._resolve_not_core_not_core_scion(dst_ia)
if not sibra:
return ret
# FIXME(kormat): Strip off PCBs, and just return sibra reservation
# blocks
return self._sibra_strip_pcbs(self._strip_nones(ret))
def _resolve_core_core(self, dst_ia, sibra=False):
"""Resolve path from core to core."""
res = set()
for cseg in self.core_segments(last_ia=self.addr.isd_as,
sibra=sibra,
**dst_ia.params()):
res.add((None, cseg, None))
if sibra:
return res
return PathCombinator.tuples_to_full_paths(res)
def _resolve_core_not_core(self, dst_ia, sibra=False):
"""Resolve path from core to non-core."""
res = set()
# First check whether there is a direct path.
for dseg in self.down_segments(first_ia=self.addr.isd_as,
last_ia=dst_ia,
sibra=sibra):
res.add((None, None, dseg))
# Check core-down combination.
for dseg in self.down_segments(last_ia=dst_ia, sibra=sibra):
dseg_ia = dseg.first_ia()
if self.addr.isd_as == dseg_ia:
pass
for cseg in self.core_segments(first_ia=dseg_ia,
last_ia=self.addr.isd_as,
sibra=sibra):
res.add((None, cseg, dseg))
if sibra:
return res
return PathCombinator.tuples_to_full_paths(res)
def _resolve_not_core_core(self, dst_ia, sibra=False):
"""Resolve path from non-core to core."""
res = set()
params = dst_ia.params()
params["sibra"] = sibra
if dst_ia[0] == self.addr.isd_as[0]:
# Dst in local ISD. First check whether DST is a (super)-parent.
for useg in self.up_segments(**params):
res.add((useg, None, None))
# Check whether dst is known core AS.
for cseg in self.core_segments(**params):
# Check do we have an up-seg that is connected to core_seg.
for useg in self.up_segments(first_ia=cseg.last_ia(), sibra=sibra):
res.add((useg, cseg, None))
if sibra:
return res
return PathCombinator.tuples_to_full_paths(res)
def _resolve_not_core_not_core_scion(self, dst_ia):
"""Resolve SCION path from non-core to non-core."""
up_segs = self.up_segments()
down_segs = self.down_segments(last_ia=dst_ia)
core_segs = self._calc_core_segs(dst_ia[0], up_segs, down_segs)
full_paths = PathCombinator.build_shortcut_paths(up_segs, down_segs)
tuples = []
for up_seg in up_segs:
for down_seg in down_segs:
tuples.append((up_seg, None, down_seg))
for core_seg in core_segs:
tuples.append((up_seg, core_seg, down_seg))
full_paths.extend(PathCombinator.tuples_to_full_paths(tuples))
return full_paths
def _resolve_not_core_not_core_sibra(self, dst_ia):
"""Resolve SIBRA path from non-core to non-core."""
res = set()
up_segs = set(self.up_segments(sibra=True))
down_segs = set(self.down_segments(last_ia=dst_ia, sibra=True))
for up_seg, down_seg in product(up_segs, down_segs):
src_core_ia = up_seg.first_ia()
dst_core_ia = down_seg.first_ia()
if src_core_ia == dst_core_ia:
res.add((up_seg, down_seg))
continue
for core_seg in self.core_segments(first_ia=dst_core_ia,
last_ia=src_core_ia,
sibra=True):
res.add((up_seg, core_seg, down_seg))
return res
def _strip_nones(self, set_):
"""Strip None entries from a set of tuples"""
res = []
for tup in set_:
res.append(tuple(filter(None, tup)))
return res
def _sibra_strip_pcbs(self, paths):
ret = []
for pcbs in paths:
resvs = []
for pcb in pcbs:
resvs.append(self._sibra_strip_pcb(pcb))
ret.append(resvs)
return ret
def _sibra_strip_pcb(self, pcb):
assert pcb.is_sibra()
pcb_ext = pcb.sibra_ext
resv_info = pcb_ext.info
resv = ResvBlockSteady.from_values(resv_info, pcb.get_n_hops())
asms = pcb.iter_asms()
if pcb_ext.p.up:
asms = reversed(list(asms))
iflist = []
for sof, asm in zip(pcb_ext.iter_sofs(), asms):
resv.sofs.append(sof)
iflist.extend(
self._sibra_add_ifs(asm.isd_as(), sof, resv_info.fwd_dir))
assert resv.num_hops == len(resv.sofs)
return pcb_ext.p.id, resv, iflist
def _sibra_add_ifs(self, isd_as, sof, fwd):
def _add(ifid):
if ifid:
ret.append((isd_as, ifid))
ret = []
if fwd:
_add(sof.ingress)
_add(sof.egress)
else:
_add(sof.egress)
_add(sof.ingress)
return ret
def _wait_for_events(self, events, deadline):
"""
Wait on a set of events, but only until the specified deadline. Returns
the number of events that happened while waiting.
"""
count = 0
for e in events:
if e.wait(max(0, deadline - SCIONTime.get_time())):
count += 1
return count
def _check_segments(self, key):
"""
Called by RequestHandler to check if a given path request can be
fulfilled.
"""
dst_ia, flags = key
return self.path_resolution(dst_ia, flags=flags)
def _fetch_segments(self, key, _):
"""
Called by RequestHandler to fetch the requested path.
"""
dst_ia, flags = key
try:
addr, port = self.dns_query_topo(PATH_SERVICE)[0]
except SCIONServiceLookupError:
log_exception("Error querying path service:")
return
req = PathSegmentReq.from_values(self.addr.isd_as, dst_ia, flags=flags)
logging.debug("Sending path request: %s", req.short_desc())
meta = self.DefaultMeta.from_values(host=addr, port=port)
self.send_meta(req, meta)
def _reply_segments(self, key, e):
"""
Called by RequestHandler to signal that the request has been fulfilled.
"""
e.set()
def _req_key_map(self, key, req_keys):
"""
Called by RequestHandler to know which requests can be answered by
`key`.
"""
ans_ia, ans_flags = key
ans_f_set = set(ans_flags)
ret = []
for req_ia, req_flags in req_keys:
req_f_set = set(req_flags)
if req_f_set != ans_f_set and (not ans_f_set & req_f_set):
# The answer and the request have no flags in common, so skip
# it.
continue
if (req_ia == ans_ia) or (req_ia == ans_ia.any_as()):
# Covers the case where a request was for ISD-0 (i.e. any path
# to a core AS in the specified ISD)
ret.append((req_ia, req_flags))
return ret
def _calc_core_segs(self, dst_isd, up_segs, down_segs):
"""
Calculate all possible core segments joining the provided up and down
segments. Returns a list of all known segments, and a seperate list of
the missing AS pairs.
"""
src_core_ases = set()
dst_core_ases = set()
for seg in up_segs:
src_core_ases.add(seg.first_ia()[1])
for seg in down_segs:
dst_core_ases.add(seg.first_ia()[1])
# Generate all possible AS pairs
as_pairs = list(product(src_core_ases, dst_core_ases))
return self._find_core_segs(self.addr.isd_as[0], dst_isd, as_pairs)
def _find_core_segs(self, src_isd, dst_isd, as_pairs):
"""
Given a set of AS pairs across 2 ISDs, return the core segments
connecting those pairs
"""
core_segs = []
for src_core_as, dst_core_as in as_pairs:
src_ia = ISD_AS.from_values(src_isd, src_core_as)
dst_ia = ISD_AS.from_values(dst_isd, dst_core_as)
if src_ia == dst_ia:
continue
seg = self.core_segments(first_ia=dst_ia, last_ia=src_ia)
if seg:
core_segs.extend(seg)
return core_segs
