8 Feb
2024
8 Feb
'24
7:49 p.m.
pespin has uploaded this change for review. (
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(-)
git pull ssh://gerrit.osmocom.org:29418/erlang/osmo-epdg refs/changes/06/35906/1
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 b1c0627..c4ba4dc 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 = 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_recovery{restart_counter = RCnt},
@@ -416,7 +420,7 @@
instance = Bearer#gtp_bearer.ebi,
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 = Bearer#gtp_bearer.ebi,
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(a)sysmocom.de>
+% Author: Pau Espin Pedrol <pespin(a)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(a)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(a)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+
--
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Gerrit-Project: erlang/osmo-epdg
Gerrit-Branch: master
Gerrit-Change-Id: I911985743af6b3fa90fd78631a562b85ecacce15
Gerrit-Change-Number: 35906
Gerrit-PatchSet: 1
Gerrit-Owner: pespin <pespin(a)sysmocom.de>
Gerrit-MessageType: newchange