def udt_send(self, dst, data_S, priority=0):
pkt = NetworkPacket(dst, data_S)
print('%s: sending packet "%s" with priority %d' % (self, pkt, priority))
#encapsulate network packet in a link frame (usually would be done by the OS)
fr = LinkFrame('Network', pkt.to_byte_S())
#enque frame onto the interface for transmission
self.intf_L[0].put(fr.to_byte_S(), 'out')
def process_MPLS_frame(self, m_fr, i):
#TODO: implement MPLS forward, or MPLS decapsulation if this is the last hop router for the path
print('%s: processing MPLS frame "%s"' % (self, m_fr))
# for now forward the frame out interface 1
try:
print(len(self.frwd_tbl_D))
print(self.frwd_tbl_D.get(0))
i = 0
while i < len(self.frwd_tbl_D):
print("In: %s out: %s, data %s" %
(self.frwd_tbl_D.get(i)['in'],
self.frwd_tbl_D.get(i)['out'], m_fr[:2]))
if (self.frwd_tbl_D.get(i)['in'] == m_fr[:2]
and self.frwd_tbl_D.get(i)['out'] == None):
fr = LinkFrame(
'Network',
MPLSFrame().decapsulate(m_fr, self.decap_tbl_D))
break
i += 1
if (i == len(self.frwd_tbl_D)):
fr = LinkFrame('MPLS', m_fr)
self.intf_L[1].put(fr.to_byte_S(), 'out', True)
print('%s: forwarding frame "%s" from interface %d to %d' %
(self, fr, i, 1))
except queue.Full:
print('%s: frame "%s" lost on interface %d' % (self, m_fr, i))
pass
def process_MPLS_frame(self, m_fr, i):
#TODO: implement MPLS forward, or MPLS decapsulation if this is the last hop router for the path
print('%s: processing MPLS frame "%s"' % (self, m_fr))
# for now forward the frame out interface 1
try:
fr = LinkFrame('Network', m_fr.to_byte_S())
self.intf_L[1].put(fr.to_byte_S(), 'out', True)
print('%s: forwarding frame "%s" from interface %d to %d' % (self, fr, i, 1))
except queue.Full:
print('%s: frame "%s" lost on interface %d' % (self, p, i))
pass
def udt_receive(self):
fr_S = self.intf_L[0].get('in')
if fr_S is None:
return
#decapsulate the network packet
fr = LinkFrame.from_byte_S(fr_S)
assert(fr.type_S == 'Network') #should be receiving network packets by hosts
pkt_S = fr.data_S
print('%s: received packet "%s"' % (self, pkt_S))
def process_MPLS_frame(self, m_fr, i):
#TODO: implement MPLS forward, or MPLS decapsulation if this is the last hop router for the path
print('%s: processing MPLS frame "%s"' % (self, m_fr))
if m_fr.label not in self.frwd_tbl_D:
print('label destination not in forward table')
return
if m_fr.isLast == '1':
ptype = "Network"
else:
ptype = "MPLS"
pkt = m_fr.pkt
o = self.frwd_tbl_D[m_fr.label]
try:
fr = LinkFrame(ptype, pkt)
self.intf_L[o].put(fr.to_byte_S(), 'out', True)
print('%s: forwarding frame "%s" from interface %d to %d' %
(self, fr, i, o))
except queue.Full:
print('%s: frame "%s" lost on interface %d' % (self, m_fr, i))
pass
def process_network_packet(self, pkt, i):
#TODO: encapsulate the packet in an MPLS frame based on self.encap_tbl_D
#for now, we just relabel the packet as an MPLS frame without encapsulation
#m_fr = pkt
if i in self.encap_tbl_D.keys():
label = self.encap_tbl_D[i][0]
intf = self.encap_tbl_D[i][1]
m_fr = MPLSFrame(label, pkt.to_byte_S())
print('%s: encapsulated packet "%s" as MPLS frame "%s"' % (self, pkt, m_fr))
#send the encapsulated packet for processing as MPLS frame
#self.process_MPLS_frame(m_fr, i)
## copied from process MLPS frame right under
try:
fr = LinkFrame('MPLS', m_fr.to_byte_S())
self.intf_L[intf].put(fr.to_byte_S(), 'out', True)
print('%s: forwarding frame "%s" from interface %d to %d' % (self, fr, i, intf))
except queue.Full:
print('%s: frame "%s" lost on interface %d' % (self, p, i))
pass
def process_MPLS_frame(self, m_fr, i):
#TODO: implement MPLS forward, or MPLS decapsulation if this is the last hop router for the path
print('%s: processing MPLS frame "%s"' % (self, m_fr.to_byte_S()))
try:
out_route = self.frwd_tbl_D.get(m_fr.lbl)
outlbl = out_route[0]
outinf = out_route[1]
if outlbl in self.decap_tbl_D: #if the label matches a label end
#decapsulate package
outpkt = m_fr.pkt
fr = LinkFrame('Network', outpkt)
#send it out
self.intf_L[outinf].put(fr.to_byte_S(), 'out', True)
else:
#forward the packet
m_fr.switch_label(outlbl)
fr = LinkFrame('MPLS', m_fr.to_byte_S())
self.intf_L[outinf].put(fr.to_byte_S(), 'out', True)
print('%s: forwarding frame "%s" from interface %d to %d' % (self, fr, i, outinf))
except queue.Full:
print('%s: frame "%s" lost on interface %d' % (self, m_fr, i))
pass
except KeyError:
print("Key Error %d." (m_fr.lbl))
return
except TypeError:
print("Type Error.")
def process_MPLS_frame(self, m_fr, i):
print('%s: processing MPLS frame "%s"' % (self, m_fr.to_byte_S()))
try:
info = self.decap_tbl_D[m_fr.label]
pkt = m_fr.network_packet
l_fr = LinkFrame('Network', pkt.to_byte_S())
out_intf = info[1]
try:
self.intf_L[out_intf].put(l_fr.to_byte_S(), 'out', True)
print(
'%s: forwarding Decapsulated NetPKT "%s" from interface %d to %d'
% (self, pkt, i, out_intf))
except queue.Full:
print('%s: frame "%s" lost on interface %d' % (self, m_fr, i))
pass
except KeyError:
try:
# Gets the info corresponding to the in_label and in interface
info = self.frwd_tbl_D[m_fr.label][i]
m_fr.label = info[0]
out_intf = info[1]
print("Assigning MPLS with new label %s" % info[0])
l_fr = LinkFrame('MPLS', m_fr.to_byte_S())
self.intf_L[out_intf].put(l_fr.to_byte_S(), 'out', True)
print('%s: forwarding frame "%s" from interface %d to %d' %
(self, m_fr, i, 1))
except queue.Full:
print('%s: frame "%s" lost on interface %d' % (self, m_fr, i))
pass
def process_MPLS_frame(self, m_fr, i, priority):
#TODO: implement MPLS forward, or MPLS decapsulation if this is the last hop router for the path
print('%s: processing MPLS frame "%s"' % (self, m_fr))
# for now forward the frame out interface 1
try:
if(self.decap_tbl_D[m_fr.dst] is "Y"):
pkt = NetworkPacket(m_fr.dst, m_fr.data_S[1:], m_fr.data_S[0])
fr = LinkFrame('Network', pkt.to_byte_S())
#self.intf_L[self.frwd_tbl_D[m_fr.dst]].put(fr.to_byte_S(), 'out', True)
j = self.frwd_tbl_D[i][priority][m_fr.dst]
self.intf_L[j].put(fr.to_byte_S(), 'out', True)
print('%s: forwarding frame "%s" from interface %d to %d' % (self, fr, i, j))
else:
fr = LinkFrame('MPLS', m_fr.to_byte_S())
#self.intf_L[self.frwd_tbl_D[m_fr.dst]].put(fr.to_byte_S(), 'out', True)
#print(i)
#print(type(priority))
#print(m_fr.dst)
j = self.frwd_tbl_D[i][priority][m_fr.dst]
self.intf_L[j].put(fr.to_byte_S(), 'out', True)
print('%s: forwarding frame "%s" from interface %d to %d' % (self, fr, i, j))
except queue.Full:
print('%s: frame "%s" lost on interface %d' % (self, m_fr, i))
pass
def process_network_packet(self, pkt, i):
#TODO: encapsulate the packet in an MPLS frame based on self.encap_tbl_D
#for now, we just relabel the packet as an MPLS frame without encapsulation
if pkt.dst in self.frwd_tbl_D:
try:
fr = LinkFrame('Network', pkt.to_byte_S())
self.intf_L[self.frwd_tbl_D[pkt.dst]].put(
fr.to_byte_S(), 'out', True)
print('%s: forwarding frame "%s" from interface %d to %d' %
(self, fr, i, self.frwd_tbl_D[pkt.dst]))
except queue.Full:
print('%s: frame "%s" lost on interface %d' % (self, pkt, i))
pass
m_fr = pkt
last = 1
for hop in self.encap_tbl_D[pkt.dst]:
m_fr = MPLSFrame(hop, m_fr, last)
last = 0
print('%s: encapsulated packet "%s" as MPLS frame "%s"' %
(self, pkt, m_fr))
#send the encapsulated packet for processing as MPLS frame
self.process_MPLS_frame(m_fr, i)
def process_queues(self):
for i in range(len(self.intf_L)):
fr_S = None #make sure we are starting the loop with a blank frame
fr_S = self.intf_L[i].get('in') #get frame from interface i
if fr_S is None:
continue # no frame to process yet
#decapsulate the packet
fr = LinkFrame.from_byte_S(fr_S)
pkt_S = fr.data_S
#process the packet as network, or MPLS
if fr.type_S == "Network":
p = NetworkPacket.from_byte_S(pkt_S) #parse a packet out
self.process_network_packet(p, i)
elif fr.type_S == "MPLS":
# TODO: handle MPLS frames
m_fr = MPLSFrame.from_byte_S(pkt_S) #parse a frame out
#send the MPLS frame for processing
self.process_MPLS_frame(m_fr, i)
else:
raise ('%s: unknown frame type: %s' % (self, fr.type_S))
def process_MPLS_frame(self, m_fr, i):
#TODO: implement MPLS forward, or MPLS decapsulation if this is the last hop router for the path
print('%s: processing MPLS frame "%s"' % (self, m_fr))
# for now forward the frame out interface 1
outInterface = self.frwd_tbl_D[(m_fr.dst, i)][1]
try:
if self.decap_tbl_D[i] == m_fr.dst:
fr = LinkFrame('Network', m_fr.to_byte_S())
self.intf_L[outInterface].put(fr.to_byte_S(), 'out', True)
print('%s: forwarding frame "%s" from interface %d to %d' %
(self, fr, i, 1))
else:
fr = LinkFrame("MPLS", m_fr.to_byte_S())
self.intf_L[outInterface].put(fr.to_byte_S(), 'out', 'True')
print('%s: forwarding frame "%s" from interface %d to %d' %
(self, fr, i, 1))
except queue.Full:
print('%s: frame "%s" lost on interface %d' % (self, m_fr, i))
pass
