pespin has submitted this change. ( https://gerrit.osmocom.org/c/erlang/osmo-epdg/+/35906?usp=email )

Change subject: Create PDP Context in tunnel after rx S6b CreateSessionResp ......................................................................

Create PDP Context in tunnel after rx S6b CreateSessionResp

This refactoring is a preparation to call the gtp_u_kmod APIs.

Change-Id: I911985743af6b3fa90fd78631a562b85ecacce15 --- M src/conv.erl M src/epdg_gtpc_s2b.erl M src/epdg_ue_fsm.erl A src/gtp_u_tun.erl M src/gtp_utils.erl 5 files changed, 145 insertions(+), 38 deletions(-)

Approvals: Jenkins Builder: Verified pespin: Looks good to me, approved

diff --git a/src/conv.erl b/src/conv.erl index a041847..95e103d 100644 --- a/src/conv.erl +++ b/src/conv.erl @@ -38,7 +38,27 @@ -include_lib("gtp_utils.hrl"). -include_lib("conv.hrl").

--export([cause_gtp2gsup/1, gtp2_paa_to_epdg_eua/1, epdg_eua_to_gsup_pdp_address/1]). +-export([ip_to_bin/1, bin_to_ip/1]). +-export([cause_gtp2gsup/1]). +-export([gtp2_paa_to_epdg_eua/1, epdg_eua_to_gsup_pdp_address/1]). + +% ergw_aaa/src/ergw_aaa_3gpp_dict.erl +% under GPLv2+ +ip_to_bin(IP) when is_binary(IP) -> + IP; + ip_to_bin({A, B, C, D}) -> + <<A, B, C, D>>; + ip_to_bin({A, B, C, D, E, F, G, H}) -> + <<A:16, B:16, C:16, D:16, E:16, F:16, G:16, H:16>>. + + bin_to_ip(<<A:8, B:8, C:8, D:8>> = IP) when is_binary(IP) -> + {A, B, C, D}; + bin_to_ip(<<A:16, B:16, C:16, D:16, E:16, F:16, G:16, H:16>> = IP) when is_binary(IP) -> + {A, B, C, D, E, F, G, H}; + bin_to_ip({_, _, _, _} = IP) -> + IP; + bin_to_ip({_, _, _, _, _, _, _, _} = IP) -> + IP.

-spec cause_gtp2gsup(integer()) -> integer().

diff --git a/src/epdg_gtpc_s2b.erl b/src/epdg_gtpc_s2b.erl index 9acbefa..05aed1b 100644 --- a/src/epdg_gtpc_s2b.erl +++ b/src/epdg_gtpc_s2b.erl @@ -258,6 +258,11 @@ lager:debug("Add bearer ~p to session ~p~n", [Bearer, Sess]), Sess#gtp_session{bearers = sets:add_element(Bearer, Sess#gtp_session.bearers)}.

+gtp_session_update_bearer(Sess, OldBearer, NewBearer) -> + SetRemoved = sets:del_element(OldBearer, Sess#gtp_session.bearers), + SetUpdated = sets:add_element(NewBearer, SetRemoved), + Sess#gtp_session{bearers = SetUpdated}. + gtp_session_del_bearer(Sess, Bearer) -> lager:debug("Remove bearer ~p from session ~p~n", [Bearer, Sess]), Sess1 = Sess#gtp_session{bearers = sets:del_element(Bearer, Sess#gtp_session.bearers)}, @@ -269,25 +274,6 @@ gtp_session_default_bearer(Sess) -> gtp_session_find_bearer_by_ebi(Sess, Sess#gtp_session.default_bearer_id).

- -update_gtp_session_from_create_session_response_ie(none, Sess) -> - Sess; -update_gtp_session_from_create_session_response_ie({_, - #v2_fully_qualified_tunnel_endpoint_identifier{ - interface_type = _Interface, - key = TEI, ipv4 = _IP4, ipv6 = _IP6}, - Next}, Sess) -> - update_gtp_session_from_create_session_response_ie(maps:next(Next), Sess#gtp_session{remote_control_tei = TEI}); -update_gtp_session_from_create_session_response_ie({_, _, Next}, - Sess) -> - update_gtp_session_from_create_session_response_ie(maps:next(Next), Sess). - -update_gtp_session_from_create_session_response_ies(#gtp{ie = IEs}, Sess) -> - update_gtp_session_from_create_session_response_ie(maps:next(maps:iterator(IEs)), Sess). - -update_gtp_session_from_create_session_response(Resp = #gtp{version = v2, type = create_session_response}, Sess) -> - update_gtp_session_from_create_session_response_ies(#gtp{ie = Resp#gtp.ie}, Sess). - % returns Sess if found, undefined it not find_gtp_session_by_local_teic(LocalControlTei, State) -> {LocalControlTei, Res} = sets:fold( @@ -313,13 +299,31 @@ lager:error("Rx unknown TEI ~p: ~p~n", [Resp#gtp.tei, Resp]), {noreply, State0}; Sess0 -> - Sess1 = update_gtp_session_from_create_session_response(Resp, Sess0), - lager:info("s2b: Updated Session after create_session_response: ~p~n", [Sess1]), - State1 = update_gtp_session(Sess0, Sess1, State0), % Do GTP specific msg parsing here, pass only relevant fields: - #{{v2_pdn_address_allocation,0} := Paa} = Resp#gtp.ie, + #{{v2_fully_qualified_tunnel_endpoint_identifier,1} := + #v2_fully_qualified_tunnel_endpoint_identifier{ + interface_type = 30, %% "S2b ePDG GTP-C" + key = RemoteTEIC, ipv4 = _IPc4, ipv6 = _IPc6}, + {v2_pdn_address_allocation,0} := Paa, + {v2_bearer_context,0} := #v2_bearer_context{instance = 0, group = BearerIE}} = Resp#gtp.ie, + % Parse BearerContext: + #{{v2_eps_bearer_id,0} := #v2_eps_bearer_id{instance = 0, eps_bearer_id = Ebi}, + {v2_fully_qualified_tunnel_endpoint_identifier,4} := + #v2_fully_qualified_tunnel_endpoint_identifier{ + interface_type = 31, %% "S2b-U ePDG GTP-U" + key = RemoteTEID, ipv4 = IPu4, ipv6 = IPu6} + } = BearerIE, + Bearer = gtp_session_find_bearer_by_ebi(Sess0, Ebi), + Sess1 = gtp_session_update_bearer(Sess0, Bearer, Bearer#gtp_bearer{remote_data_tei = RemoteTEID}), + Sess2 = Sess1#gtp_session{remote_control_tei = RemoteTEIC}, + lager:info("s2b: Updated Session after create_session_response: ~p~n", [Sess2]), + State1 = update_gtp_session(Sess0, Sess2, State0), ResInfo = #{ - eua => conv:gtp2_paa_to_epdg_eua(Paa) + eua => conv:gtp2_paa_to_epdg_eua(Paa), + local_teid => Bearer#gtp_bearer.local_data_tei, + remote_teid => RemoteTEID, + remote_ipv4 => IPu4, + remote_ipv6 => IPu6 }, epdg_ue_fsm:received_gtpc_create_session_response(Sess0#gtp_session.pid, {ok, ResInfo}), {noreply, State1} @@ -406,7 +410,7 @@ instance = Bearer#gtp_bearer.ebi, interface_type = 31, %% "S2b-U ePDG GTP-U" key = Bearer#gtp_bearer.local_data_tei, - ipv4 = gtp_utils:ip_to_bin(LocalAddr) + ipv4 = conv:ip_to_bin(LocalAddr) } ], IEs = [#v2_recovery{restart_counter = RCnt}, @@ -416,7 +420,7 @@ instance = 0, interface_type = 30, %% "S2b ePDG GTP-C" key = LocalCtlTEI, - ipv4 = gtp_utils:ip_to_bin(LocalAddr) + ipv4 = conv:ip_to_bin(LocalAddr) }, #v2_access_point_name{instance = 0, apn = [Apn]}, #v2_selection_mode{mode = 0}, @@ -438,7 +442,7 @@ instance = 0, interface_type = 30, %% "S2b ePDG GTP-C" key = Bearer#gtp_bearer.local_data_tei, - ipv4 = gtp_utils:ip_to_bin(LocalAddr) + ipv4 = conv:ip_to_bin(LocalAddr) } ], #gtp{version = v2, type = delete_session_request, tei = RemoteCtlTEI, seq_no = SeqNo, ie = IEs}. @@ -461,7 +465,7 @@ instance = 0, interface_type = 31, %% "S2b-U ePDG GTP-U" key = Bearer#gtp_bearer.local_data_tei, - ipv4 = gtp_utils:ip_to_bin(LocalAddr) + ipv4 = conv:ip_to_bin(LocalAddr) } ], IEs = [#v2_cause{v2_cause = GtpCause}, diff --git a/src/epdg_ue_fsm.erl b/src/epdg_ue_fsm.erl index fa780e8..7568db0 100644 --- a/src/epdg_ue_fsm.erl +++ b/src/epdg_ue_fsm.erl @@ -244,6 +244,16 @@

state_authenticated({call, From}, {received_gtpc_create_session_response, Result}, Data) -> lager:info("ue_fsm state_authenticated event=received_gtpc_create_session_response, ~p~n", [Data]), + case Result of + {ok, ResInfo} -> + #{eua := EUA, + local_teid := LocalTEID, + remote_teid := RemoteTEID, + remote_ipv4 := RemoteIPv4 % TODO: remote_ipv6 + } = ResInfo, + gtp_u_tun:create_pdp_context(RemoteIPv4, EUA, LocalTEID, RemoteTEID); + _ -> ok + end, gsup_server:tunnel_response(Data#ue_fsm_data.imsi, Result), {keep_state, Data, [{reply,From,ok}]};

diff --git a/src/gtp_u_tun.erl b/src/gtp_u_tun.erl new file mode 100644 index 0000000..e08b804 --- /dev/null +++ b/src/gtp_u_tun.erl @@ -0,0 +1,70 @@ +% GTP-U tun related functionalities +% +% (C) 2024 by sysmocom - s.f.m.c. GmbH info@sysmocom.de +% Author: Pau Espin Pedrol pespin@sysmocom.de +% +% All Rights Reserved +% +% This program is free software; you can redistribute it and/or modify +% it under the terms of the GNU Affero General Public License as +% published by the Free Software Foundation; either version 3 of the +% License, or (at your option) any later version. +% +% This program is distributed in the hope that it will be useful, +% but WITHOUT ANY WARRANTY; without even the implied warranty of +% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +% GNU General Public License for more details. +% +% You should have received a copy of the GNU Affero General Public License +% along with this program. If not, see http://www.gnu.org/licenses/. +% +% Additional Permission under GNU AGPL version 3 section 7: +% +% If you modify this Program, or any covered work, by linking or +% combining it with runtime libraries of Erlang/OTP as released by +% Ericsson on http://www.erlang.org (or a modified version of these +% libraries), containing parts covered by the terms of the Erlang Public +% License (http://www.erlang.org/EPLICENSE), the licensors of this +% Program grant you additional permission to convey the resulting work +% without the need to license the runtime libraries of Erlang/OTP under +% the GNU Affero General Public License. Corresponding Source for a +% non-source form of such a combination shall include the source code +% for the parts of the runtime libraries of Erlang/OTP used as well as +% that of the covered work. + +-module(gtp_u_tun). +-author('Pau Espin Pedrol pespin@sysmocom.de'). +-include("conv.hrl"). + +-export([create_pdp_context/4]). + +%%%%%%%%%%%%%%%%%%%%%% +%%% Internal API +%%%%%%%%%%%%%%%%%%%%%% + +% Obtain ServerRef of the gtp_u_kmod_port process spawned during startup based on +% gtp_u_kmod config: +get_env_gtp_u_kmod_server_ref() -> + GtpuKmodSockets = application:get_env(gtp_u_kmod, sockets, []), + [GtpuKmodSocket | _] = GtpuKmodSockets, + {GtpuKmodName, _GtpuKmodSockOpts} = GtpuKmodSocket, + GtpuKmodServRef = gtp_u_kmod_port:port_reg_name(GtpuKmodName), + GtpuKmodServRef. + + +%%%%%%%%%%%%%%%%%%%%%% +%%% Internal API +%%%%%%%%%%%%%%%%%%%%%% + +% Create a PDP Context on the GTP tundev +create_pdp_context(PeerAddr, EUA, LocalTEID, RemoteTEID) -> + %SGSNaddr = {127,0,0,1}, % TODO: This should be set to the GTP-U IP address provided by the PGW + %EUA = {127,0,0,1}, % TODO: This should be set to the EUA IP address provided by the PGW + %LocalTEID = 1234, % TODO: this should be set to our locally generated TEID. + %RemoteTEID = 56768, % TODO: this should be set to TEID obtained from CreateSessionResponse + PeerIP = conv:bin_to_ip(PeerAddr), % TODO: IPv6 + UEIP = conv:bin_to_ip(EUA#epdg_eua.ipv4), % TODO: IPv6. + ok. + % TODO: This will be enabled once we depend on the gtp_u_kmod module: + %ServRef = get_env_gtp_u_kmod_server_ref(), + %gen_server:call(ServRef, {PeerIP, UEIP, LocalTEID, RemoteTEID}). \ No newline at end of file diff --git a/src/gtp_utils.erl b/src/gtp_utils.erl index eb0a23a..6098da2 100644 --- a/src/gtp_utils.erl +++ b/src/gtp_utils.erl @@ -35,16 +35,8 @@ -module(gtp_utils). -author('Alexander Couzens lynxis@fe80.eu').

--export([ip_to_bin/1, plmn_to_bin/3, enum_v2_cause/1]). +-export([plmn_to_bin/3, enum_v2_cause/1]).

-% ergw_aaa/src/ergw_aaa_3gpp_dict.erl -% under GPLv2+ -ip_to_bin(IP) when is_binary(IP) -> - IP; -ip_to_bin({A, B, C, D}) -> - <<A, B, C, D>>; -ip_to_bin({A, B, C, D, E, F, G, H}) -> - <<A:16, B:16, C:16, D:16, E:16, F:16, G:16, H:16>>.

% ergw/apps/ergw/test/*.erl % under GPLv2+