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SDP parsing
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@nickvsnetworking
nickvsnetworking committed Jan 14, 2024
1 parent 03245ad commit 72a4b17
Showing 1 changed file with 83 additions and 7 deletions.
90 changes: 83 additions & 7 deletions lib/diameter.py
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Original file line number Diff line number Diff line change
Expand Up @@ -13,6 +13,7 @@
import json
import time
import traceback
import re

class Diameter:

Expand Down Expand Up @@ -1183,7 +1184,7 @@ def Charging_Rule_Generator(self, ChargingRules=None, ue_ip=None, chargingRuleNa
#Populate all Flow Information AVPs
Flow_Information = ''
for tft in ChargingRules['tft']:
self.logTool.log(service='HSS', level='debug', message=tft, redisClient=self.redisMessaging)
self.logTool.log(service='HSS', level='debug', message="Adding TFT: " + str(tft), redisClient=self.redisMessaging)
#If {{ UE_IP }} in TFT splice in the real UE IP Value
try:
tft['tft_string'] = tft['tft_string'].replace('{{ UE_IP }}', str(ue_ip))
Expand Down Expand Up @@ -2885,6 +2886,81 @@ def Answer_16777236_265(self, packet_vars, avps):
except Exception as e:
pass

#Extract the SDP for each direction to find the source and destination IP Addresses and Ports used for the RTP streams
try:
sdp1 = self.get_avp_data(avps, 524)[0]
self.logTool.log(service='HSS', level='debug', message=f"[diameter.py] [Answer_16777236_265] [AAA] got first SDP body raw: " + str(sdp1), redisClient=self.redisMessaging)
sdp1 = binascii.unhexlify(sdp1).decode('utf-8')
self.logTool.log(service='HSS', level='debug', message=f"[diameter.py] [Answer_16777236_265] [AAA] got first SDP body decoded: " + str(sdp1), redisClient=self.redisMessaging)
sdp2 = self.get_avp_data(avps, 524)[1]
self.logTool.log(service='HSS', level='debug', message=f"[diameter.py] [Answer_16777236_265] [AAA] got second SDP body raw: " + str(sdp2), redisClient=self.redisMessaging)
sdp2 = binascii.unhexlify(sdp2).decode('utf-8')
self.logTool.log(service='HSS', level='debug', message=f"[diameter.py] [Answer_16777236_265] [AAA] got second SDP body decoded: " + str(sdp2), redisClient=self.redisMessaging)

regex_ipv4 = r"IN IP4 (\d*\.\d*\.\d*\.\d*)"
regex_ipv6 = r"IN IP6 ([0-9a-fA-F:]{3,39})"
regex_port_audio = r"m=audio (\d*)"
regex_port_rtcp = r"a=rtcp:(\d*)"

#Check for IPv4 Matches in first SDP Body
matches_ipv4 = re.search(regex_ipv4, sdp1, re.MULTILINE)
if matches_ipv4:
sdp1_ipv4 = str(matches_ipv4.group(1))
self.logTool.log(service='HSS', level='debug', message=f"[diameter.py] [Answer_16777236_265] [AAA] Matched SDP IPv4" + str(sdp1_ipv4), redisClient=self.redisMessaging)
else:
self.logTool.log(service='HSS', level='debug', message=f"[diameter.py] [Answer_16777236_265] [AAA] No matches for IPv4 in SDP", redisClient=self.redisMessaging)
if not matches_ipv4:
#Check for IPv6 Matches
matches_ipv6 = re.search(regex_ipv6, sdp1, re.MULTILINE)
if matches_ipv6:
sdp1_ipv6 = str(matches_ipv6.group(1))
self.logTool.log(service='HSS', level='debug', message=f"[diameter.py] [Answer_16777236_265] [AAA] Matched SDP IPv6" + str(sdp1_ipv6), redisClient=self.redisMessaging)
else:
self.logTool.log(service='HSS', level='debug', message=f"[diameter.py] [Answer_16777236_265] [AAA] No matches for IPv6 in SDP", redisClient=self.redisMessaging)


#Check for IPv4 Matches in second SDP Body
matches_ipv4 = re.search(regex_ipv4, sdp2, re.MULTILINE)
if matches_ipv4:
sdp2_ipv4 = str(matches_ipv4.group(1))
self.logTool.log(service='HSS', level='debug', message=f"[diameter.py] [Answer_16777236_265] [AAA] Matched SDP2 IPv4 " + str(sdp2_ipv4), redisClient=self.redisMessaging)
else:
self.logTool.log(service='HSS', level='debug', message=f"[diameter.py] [Answer_16777236_265] [AAA] No matches for IPv4 in SDP2", redisClient=self.redisMessaging)
if not matches_ipv4:
#Check for IPv6 Matches
matches_ipv6 = re.search(regex_ipv6, sdp2, re.MULTILINE)
if matches_ipv6:
sdp2_ipv6 = str(matches_ipv6.group(1))
self.logTool.log(service='HSS', level='debug', message=f"[diameter.py] [Answer_16777236_265] [AAA] Matched SDP2 IPv6 " + str(sdp2_ipv6), redisClient=self.redisMessaging)
else:
self.logTool.log(service='HSS', level='debug', message=f"[diameter.py] [Answer_16777236_265] [AAA] No matches for IPv6 in SDP", redisClient=self.redisMessaging)

#Extract RTP Port
matches_rtp_port = re.search(regex_port_audio, sdp2, re.MULTILINE)
if matches_rtp_port:
sdp2_rtp_port = str(matches_rtp_port.group(1))
self.logTool.log(service='HSS', level='debug', message=f"[diameter.py] [Answer_16777236_265] [AAA] Matched SDP2 RTP Port " + str(sdp2_rtp_port), redisClient=self.redisMessaging)

#Extract RTP Port
matches_rtp_port = re.search(regex_port_audio, sdp1, re.MULTILINE)
if matches_rtp_port:
sdp1_rtp_port = str(matches_rtp_port.group(1))
sdp1_rtcp_port = int(sdp1_rtp_port) - 1
self.logTool.log(service='HSS', level='debug', message=f"[diameter.py] [Answer_16777236_265] [AAA] Matched SDP1 RTP Port " + str(sdp1_rtp_port), redisClient=self.redisMessaging)


#Extract RTP Port
matches_rtp_port = re.search(regex_port_audio, sdp2, re.MULTILINE)
if matches_rtp_port:
sdp2_rtp_port = str(matches_rtp_port.group(1))
sdp2_rtcp_port = int(sdp2_rtp_port) - 1
self.logTool.log(service='HSS', level='debug', message=f"[diameter.py] [Answer_16777236_265] [AAA] Matched SDP2 RTP Port " + str(sdp2_rtp_port), redisClient=self.redisMessaging)


except Exception as e:
self.logTool.log(service='HSS', level='debug', message=f"[diameter.py] [Answer_16777236_265] [AAA] Failed to extract SDP due to error" + str(e), redisClient=self.redisMessaging)


"""
The below logic is applied:
1. Grab the Flow Rules and bitrates from the PCSCF in the AAR,
Expand All @@ -2897,14 +2973,14 @@ def Answer_16777236_265(self, packet_vars, avps):
chargingRule = {
"charging_rule_id": 1000,
"qci": 1,
"arp_preemption_capability": True,
"arp_preemption_capability": False,
"mbr_dl": dlBandwidth,
"mbr_ul": ulBandwidth,
"gbr_ul": ulBandwidth,
"precedence": 100,
"arp_priority": 2,
"precedence": 40,
"arp_priority": 15,
"rule_name": "GBR-Voice",
"arp_preemption_vulnerability": False,
"arp_preemption_vulnerability": True,
"gbr_dl": dlBandwidth,
"tft_group_id": 1,
"rating_group": None,
Expand All @@ -2913,13 +2989,13 @@ def Answer_16777236_265(self, packet_vars, avps):
"tft_group_id": 1,
"direction": 1,
"tft_id": 1,
"tft_string": "permit out 17 from {{ UE_IP }}/32 1-65535 to any 1-65535"
"tft_string": "permit out 17 from " + str(sdp2_ipv4) + "/32 " + str(sdp2_rtcp_port) + "-" + str(sdp2_rtp_port) + " to " + str(ueIp) + "/32 " + str(sdp1_rtcp_port) + "-" + str(sdp1_rtp_port)
},
{
"tft_group_id": 1,
"direction": 2,
"tft_id": 2,
"tft_string": "permit out 17 from {{ UE_IP }}/32 1-65535 to any 1-65535"
"tft_string": "permit out 17 from " + str(sdp2_ipv4) + "/32 " + str(sdp2_rtcp_port) + "-" + str(sdp2_rtp_port) + " to " + str(ueIp) + "/32 " + str(sdp1_rtcp_port) + "-" + str(sdp1_rtp_port)
}
]
}
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