Add some basic support for offering ice-lite using rtpproxy's

module with the same name.

sippy/Rtp_proxy/Session/side.py

@@ -34,6 +34,8 @@
 from sippy.Rtp_proxy.Session.update import update_params
 from sippy.Rtp_proxy.Session.subcommand import subcommand_dtls, \
   subcommand_dedtls, DTLS_TRANSPORTS
+from sippy.Rtp_proxy.Session.subcommand_ice import subcommand_ice, \
+  subcommand_deice
 
 try:
     strtypes = (str, unicode)
@@ -49,6 +51,7 @@ class _rtpps_side(object):
     oh_remote = None
     repacketize = None
     gateway_dtls = 'pass'
+    deice = False
     soft_repacketize = False
     after_sdp_change = None
     needs_new_port = False
@@ -189,8 +192,12 @@ def _on_sdp_change(self, rtpps, sdp_body, result_callback, en_excpt):
             up.index = si
             if otherside.gateway_dtls == 'dtls':
                 up.subcommands.append(subcommand_dtls())
+            if otherside.deice:
+                up.subcommands.append(subcommand_ice())
             if self.gateway_dtls == 'dtls' and sect.m_header.transport in DTLS_TRANSPORTS:
                 up.subcommands.append(subcommand_dedtls(sdp_bc, sect))
+            if self.deice:
+                up.subcommands.append(subcommand_deice(sdp_bc, sect))
             up.result_callback = partial(self._sdp_change_finish, sdp_body, sect, sects, result_callback)
             self.update(up)
         return

sippy/Rtp_proxy/Session/subcommand_ice.py

@@ -0,0 +1,98 @@
+# Copyright (c) 2024 Sippy Software, Inc. All rights reserved.
+#
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without modification,
+# are permitted provided that the following conditions are met:
+#
+# 1. Redistributions of source code must retain the above copyright notice, this
+# list of conditions and the following disclaimer.
+#
+# 2. Redistributions in binary form must reproduce the above copyright notice,
+# this list of conditions and the following disclaimer in the documentation and/or
+# other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+# ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+# ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+from urllib.parse import unquote
+
+from sippy.Exceptions.RtpProxyError import RtpProxyError
+from sippy.Exceptions.SipParseError import SdpParseError
+from sippy.Rtp_proxy.Session.subcommand import subcommand
+
+ICE_ATTRS = ('ice-ufrag', 'ice-pwd')
+ICE_ATTRS_RM = ICE_ATTRS + ('candidate', 'ice-options', 'rtcp-mux',
+  'end-of-candidates', 'ice-options')
+ICE_ATTRS_RM += ('extmap', 'extmap-allow-mixed', 'msid',
+  'msid-semantic', 'mid', 'group', 'rtcp-fb')
+
+class subcommand_ice(subcommand):
+    name = 'ICE'
+    ice_lufrag: str
+    ice_lpwd: str
+    ice_candidates: list
+    i_mod = subcommand.mod_2_i_mod['ice_lite']
+
+    def __init__(self):
+        super().__init__(f'{self.i_mod} S')
+
+    def handle_results(self, results, ur):
+        if ex:=super().handle_results(results, ur): return ex
+        ice_res = results[0].split()
+        if len(ice_res) < 3:
+            return RtpProxyError(f'RTPProxy errored: {self.name}: {results=}')
+        self.ice_lufrag, self.ice_lpwd = ice_res[:2]
+        self.ice_candidates = [unquote(r[2:]) for r in ice_res[2:]]
+        ur.sdp_sect_fins.append(self.sdp_sect_fin)
+        return None
+
+    def sdp_sect_fin(self, sdp_bc, sect):
+        self._sdp_attrs_rm(sdp_bc, sect, ICE_ATTRS_RM)
+        sect.addHeader('a', 'rtcp-mux')
+        sect.addHeader('a', 'ice-lite')
+        sect.addHeader('a', F'ice-ufrag:{self.ice_lufrag}')
+        sect.addHeader('a', F'ice-pwd:{self.ice_lpwd}')
+        for cand in self.ice_candidates:
+            sect.addHeader('a', F'candidate:{cand}')
+        sect.m_header.transport = 'UDP/TLS/RTP/SAVP'
+
+class subcommand_deice(subcommand):
+    name = 'deICE'
+    i_mod = subcommand.mod_2_i_mod['ice_lite']
+
+    def __init__(self, sdp_bc, sect):
+        adict = dict([(x.name, x.value) for x in sect.a_headers
+                        if x.name in ICE_ATTRS])
+        for rattr in ('ice-ufrag', 'ice-pwd'):
+            if rattr not in adict:
+                raise SdpParseError(f'Missing ICE {rattr} parameter')
+        super().__init__(f'{self.i_mod} A {adict["ice-ufrag"]} {adict["ice-pwd"]}')
+        for cand in (x.value for x in sect.a_headers
+                        if x.name == 'candidate'):
+            pts = cand.split(None, 4)
+            if pts[2].lower() != 'udp':
+                continue
+            self.append(f'{self.i_mod} C {cand}')
+
+    def handle_results(self, results, ur):
+        if ex:=super().handle_results(results, ur): return ex
+        if any(True for r in results if r != '0'):
+            return RtpProxyError(f'RTPProxy errored: {self.name}: {results=}')
+        ur.sdp_sect_fins.append(self.sdp_sect_fin)
+        return None
+
+    def sdp_sect_fin(self, sdp_bc, sect):
+        self._sdp_attrs_rm(sdp_bc, sect, ICE_ATTRS_RM)
+        for a in [a for a in sect.a_headers if a.name == 'ssrc']:
+            ssrc, attr = a.value.split(None, 1)
+            if not attr.lower().startswith('msid:'): continue
+            sect.a_headers.remove(a)