Enable dtls use on 22.04

README.md

@@ -93,14 +93,19 @@ where `gentype` of "fullvalid" generates valid BPv7 test bundles, and `gencount`
 The `run.py` commands use the environment `DOCKER` to control the container tool.
 For example in fedora use the environment `DOCKER="sudo podman"`.
 
+To install prerequisites for python run:
+```
+pip3 install '.[container]'
+```
+
 To initialize and start a set of containers:
 ```
 python3 container/run.py --config container/example.yaml delete prep start
 ```
 
 To observe the log of one of the nodes:
 ```
-docker container exec -it node003 journalctl -f
+docker container exec -it node000 journalctl -f
 ```
 
 To capture traffic across container networks, run similar to:
@@ -110,7 +115,7 @@ wireshark -i br-dtnA -i br-dtnB -f 'port 4556 or port 1113 or icmp' -Y 'bpv7' -k
 
 To call DBus methods in one of the nodes:
 ```
-docker container exec -it node003 dbus-send --system --print-reply --dest=org.ietf.dtn.node.udpcl /org/ietf/dtn/udpcl/Agent org.ietf.dtn.udpcl.Agent.pmtud_start string:node002. uint16:4556
+docker container exec -it node000 dbus-send --system --print-reply --dest=org.ietf.dtn.node.udpcl /org/ietf/dtn/udpcl/Agent org.ietf.dtn.udpcl.Agent.pmtud_start string:node002. uint16:4556
 ```
 
 To perform an ACME validation exchange between two nodes run the script:

container/Dockerfile

@@ -32,6 +32,14 @@ RUN --mount=type=cache,target=/root/.cache/pip \
     pip3 install --upgrade pip && \
     pip3 install pip-tools maturin
 
+# Work-around python3-dtls requiring openssl-1.1 but not available on 22.04
+RUN --mount=type=cache,target=/var/cache/apt apt-get update && \
+    apt-get install -yq curl && \
+    curl -svLO http://archive.ubuntu.com/ubuntu/pool/main/o/openssl/libssl1.1_1.1.1f-1ubuntu2.23_amd64.deb && \
+    dpkg -i libssl1.1_*_amd64.deb && \
+    apt-get -fy install && \
+    rm libssl1.1_*_amd64.deb
+
 COPY pyproject.toml /root/agent/
 #RUN --mount=type=cache,target=/root/.cache/pip \
 #    cd /root/agent && \

src/udpcl/agent.py

@@ -391,6 +391,9 @@ def listen(self, address, port, opts=None):
         sock = conv.make_local_socket()
         self.__logger.info('Listening on %s:%d', conv.local_address, conv.local_port)
 
+        if conv.family == socket.AF_INET:
+            sock.setsockopt(socket.IPPROTO_IP, socket.IP_RECVTOS, 1)
+
         multicast_member = opts.get('multicast_member', [])
         for item in multicast_member:
             addr = str(item['addr'])
@@ -692,6 +695,9 @@ def _sock_recvfrom(self, sock, *_args, **_kwargs):
 
         self.__logger.info('Received %d octets via plain on %s',
                            len(data), conv)
+        for cmsg_level, cmsg_type, cmsg_data in ancdata:
+            if (cmsg_level, cmsg_type) == (socket.IPPROTO_IP, socket.IP_TOS):
+                self.__logger.info('With TOS field %02x', cmsg_data[0])
         self._plain_sock[conv.key] = sock
         self._recv_datagram(sock, data, conv, ip_tos)
         return True