trx_toolkit: Add cmdline arg to set bind addr

Previous hardcoded default of 0.0.0.0 was inappropiate in some
scenarios, as it sets the SRC addr of the packets sent through the
socket based on the routing.

For instance, if iface IF1 has assigned two IP addresses A and B,
A being the first addr of the interface, and osmo-bts-trx is
configured with "osmotrx ip local A" and "osmotrx ip remote B",
the following happens:

  CMD POWER OFF src=A:5801 dst=B:5701
  RSP POWER OFF src=A:5701 dst=A:5701 <-- A is assigned as src addr.

But osmo-bts-trx is waiting for packets from B:5701, and the packet
is dropped with ICMP Unreachable. If addr binding is forced in
fake_trx to B, then everthing's fine.

Let's extend the UDPLink in order to allow manual, but optional
setting of bind address, and add a corresponding cmdline
argument to all executables.

Change-Id: I7be18fef40967fb7551f4115f22cbbd9cdb0840d

1 files changed, 20 insertions, 13 deletions

diff --git a/src/target/trx_toolkit/fake_trx.py b/src/target/trx_toolkit/fake_trx.py
index 1fcd3df9..b818b2a9 100755
--- a/src/target/trx_toolkit/fake_trx.py
+++ b/src/target/trx_toolkit/fake_trx.py
@@ -42,6 +42,7 @@ class Application:
 	# Application variables
 	bts_addr = "127.0.0.1"
 	bb_addr = "127.0.0.1"
+	trx_bind_addr = "0.0.0.0"
 	bts_base_port = 5700
 	bb_base_port = 6700
 
@@ -60,12 +61,12 @@ class Application:
 
 	def run(self):
 		# Init TRX CTRL interface for BTS
-		self.bts_ctrl = CTRLInterfaceBTS(self.bts_addr,
-			self.bts_base_port + 101, self.bts_base_port + 1)
+		self.bts_ctrl = CTRLInterfaceBTS(self.bts_addr, self.bts_base_port + 101,
+			self.trx_bind_addr, self.bts_base_port + 1)
 
 		# Init TRX CTRL interface for BB
-		self.bb_ctrl = CTRLInterfaceBB(self.bb_addr,
-			self.bb_base_port + 101, self.bb_base_port + 1)
+		self.bb_ctrl = CTRLInterfaceBB(self.bb_addr, self.bb_base_port + 101,
+			self.trx_bind_addr, self.bb_base_port + 1)
 
 		# Power measurement emulation
 		# Noise: -120 .. -105
@@ -77,10 +78,10 @@ class Application:
 		self.bb_ctrl.pm = self.pm
 
 		# Init DATA links
-		self.bts_data = UDPLink(self.bts_addr,
-			self.bts_base_port + 102, self.bts_base_port + 2)
-		self.bb_data = UDPLink(self.bb_addr,
-			self.bb_base_port + 102, self.bb_base_port + 2)
+		self.bts_data = UDPLink(self.bts_addr, self.bts_base_port + 102,
+			self.trx_bind_addr, self.bts_base_port + 2)
+		self.bb_data = UDPLink(self.bb_addr, self.bb_base_port + 102,
+			self.trx_bind_addr, self.bb_base_port + 2)
 
 		# BTS <-> BB burst forwarding
 		self.burst_fwd = BurstForwarder(self.bts_data, self.bb_data)
@@ -94,8 +95,8 @@ class Application:
 		self.bb_ctrl.burst_fwd = self.burst_fwd
 
 		# Provide clock to BTS
-		self.bts_clck = UDPLink(self.bts_addr,
-			self.bts_base_port + 100, self.bts_base_port)
+		self.bts_clck = UDPLink(self.bts_addr, self.bts_base_port + 100,
+			self.trx_bind_addr, self.bts_base_port)
 		self.clck_gen = CLCKGen([self.bts_clck])
 		self.bts_ctrl.clck_gen = self.clck_gen
 
@@ -142,7 +143,8 @@ class Application:
 			 "  -R --bts-addr       Set BTS remote address (default %s)\n"   \
 			 "  -r --bb-addr        Set BB remote address (default %s)\n"    \
 			 "  -P --bts-base-port  Set BTS base port number (default %d)\n" \
-			 "  -p --bb-base-port   Set BB base port number (default %d)\n\n"
+			 "  -p --bb-base-port   Set BB base port number (default %d)\n" \
+			 "  -b --trx-bind-addr  Set TRX bind address (default %s)\n\n"
 
 		s += " Simulation\n" \
 			 "  --rand-dl-rssi      Enable DL RSSI randomization\n"   \
@@ -151,7 +153,8 @@ class Application:
 			 "  --rand-ul-toa       Enable UL ToA randomization\n"
 
 		print(s % (self.bts_addr, self.bb_addr,
-			self.bts_base_port, self.bb_base_port))
+			self.bts_base_port, self.bb_base_port,
+			self.trx_bind_addr))
 
 		if msg is not None:
 			print(msg)
@@ -159,11 +162,12 @@ class Application:
 	def parse_argv(self):
 		try:
 			opts, args = getopt.getopt(sys.argv[1:],
-				"R:r:P:p:h",
+				"R:r:P:p:b:h",
 				[
 					"help",
 					"bts-addr=", "bb-addr=",
 					"bts-base-port=", "bb-base-port=",
+					"trx-bind-addr=",
 					"rand-dl-rssi", "rand-ul-rssi",
 					"rand-dl-toa", "rand-ul-toa",
 				])
@@ -186,6 +190,9 @@ class Application:
 			elif o in ("-p", "--bb-base-port"):
 				self.bb_base_port = int(v)
 
+			elif o in ("-b", "--trx-bind-addr"):
+				self.trx_bind_addr = v
+
 			# Message field randomization
 			elif o == "rand-dl-rssi":
 				self.randomize_dl_rssi = True