Commit Graph

34 Commits

Author SHA1 Message Date
Oliver Smith 5c11306e45 bsc_nat_fsm: tweak get_peer_addr
Rename the function from sccp_sap_get_peer_addr_in to get_peer_addr to
make the code using it slightly more readable.  The _in at the end of
the function is not needed anymore, this was used to differentiate from
peer_addr_out which was used in the caller code before the connection
mapping was implemented in I1556aa665fbb0a97507f98794e74820731fa6935.
Now instead of peer_addr_out, subscr_conn->bsc->addr or
subscr_conn->msc->addr are used.

Rename variable arguments to sccp_inst and addr to be consistent with
the variable names in the callers.

Related: SYS#5560
Change-Id: Ie023360724254be54cbaac4490b0341dfe68399f
2022-03-23 09:22:21 +00:00
Oliver Smith 499e1117a6 Support forwarding messages with multiple BSCs
Implement a proper subscriber connection mapping. Create a new
subscr_conn when one of the stored BSCs sends a conn.ind and use that
subscr_conn for all related connection-oriented messages with the same
RAN-side conn_id to send messages back and forth between BSC and MSC.

Add subscr_conn_get_next_id based on OsmoBSC's
bsc_sccp_inst_next_conn_id.

With this patch, it's possible to do a successful Location Updating
procedure between MS2 and MSC in the following network:

  MS1 --- BTS1 --- BSC1 --.
                          BSCNAT --- MSC
  MS2 --- BTS2 --- BSC2 --'

Related: SYS#5560
Change-Id: I1556aa665fbb0a97507f98794e74820731fa6935
2022-03-21 16:36:32 +01:00
Oliver Smith 1968ca922b sccp_sap_up_ran: ignore RAN until MSC is connected
Related: SYS#5560
Change-Id: Idf9501412484fa92e8836952609fba7c5443d6c9
2022-03-21 16:36:32 +01:00
Oliver Smith 70cd49dcae Send RESET to MSC on start up
Automatically send RESET to the MSC as the BSCNAT starts up. Try it
again if it fails, in case the MSC was not started yet or if the SCCP
connection was not up yet (right now it does not seem possible to get
notified when the SCCP connection is up).

Related: SYS#5560
Related: https://osmocom.org/projects/osmo-bscnat/wiki/AoIP_OsmoBSCNAT#RESET
Change-Id: Icfec3ec0168c7040e88a536fa48da339349fb6cf
2022-03-21 16:36:32 +01:00
Oliver Smith 49e50de426 Store MSC
Expect one MSC to be configured in the address book (part of the cs7
section in the config, see doc/examples/osmo-bsc-nat/osmo-bsc-nat.cfg)
and store it on start up.

Store the MSC in a list, as we may potentially support multiple MSCs in
the future. Also that makes it symmetric to the BSC list.

Don't use the stored MSCs in the forwarding logic just yet, a future
commit will replace the current forwarding code with proper connection
mappings.

Related: SYS#5560
Change-Id: I711df0c649728f1007857fbfda500ed5ef69287b
2022-03-21 16:36:32 +01:00
Oliver Smith 793ca23f07 Store BSCs
Once a BSC has sent a RESET to BSCNAT, store it. This will be used in
future patches to build connection mappings between MSC and BSCs, and to
block messages from BSCs that did not send a RESET.

I've considered using a FSM, but at least right now there doesn't seem
to be multiple states worth storing. We only have the BSC before it has
done the RESET (and then it's simply not in our list) and after it did
the RESET (in the list).

Don't use the stored BSCs in the forwarding logic just yet, a future
commit will replace the current forwarding code with proper connection
mappings.

Related: SYS#5560
Change-Id: Icd7316c49ef26fb45ad45a2ccc1a7916bfb0a387
2022-03-21 16:36:32 +01:00
Oliver Smith 318b4820fc bsc_nat: use sub-structs for cn, ran
As suggested in code review, create sub-structs for cn and ran. The
following patches will fill them up with mscs, bscs etc.

Related: SYS#5560
Change-Id: I6a3cc0d837a3d89e7153c2296812df0863f3471f
2022-03-21 16:36:32 +01:00
Oliver Smith 0aa4cb372b bsc_nat_print_addr: pass net enum, not sccp_inst
The sccp_inst was only used to differentiate between CN / RAN. Instead
of passing that, pass an enum and add bsc_nat_print_addr_cn and _ran
defines to keep it short.

This is in preparation for refactoring struct bsc_nat as suggested in
code review.

Related: SYS#5560
Change-Id: I3c6046a6726c31bf137223c46c2c96b3898ad324
2022-03-21 16:36:32 +01:00
Oliver Smith d0059e2bd2 Reply to BSC's RESET with RESET ACK directly
Let the BSCNAT directly reply to RESET sent from BSC with RESET ACK.
bssap_ran_handle_reset() is a bit empty right now but will be used in a
future patch to store the BSC.

Related: SYS#5560
Related: https://osmocom.org/projects/osmo-bscnat/wiki/AoIP_OsmoBSCNAT#RESET
Change-Id: I3223409e25c93b625d67634caf68efe9772e2558
2022-03-21 16:36:21 +01:00
Oliver Smith 8ca3a1ad8f bsc_nat_sccp_inst: local_sccp_addr -> addr
Make it a bit shorter, it's clear that this refers to the local address
of the OsmoBSCNAT in CN/RAN.

Related: SYS#5560
Change-Id: I3083374d589487ed960507e7a431c45914afc5dd
2022-03-10 18:55:16 +01:00
Oliver Smith 2ec692d73b bsc_nat_fsm: split up sccp_sap_up in _cn, _ran
Prepare for future patches where more will happen in the callback
function. Split it up into two functions, one for CN and one for RAN, so
we don't need to constantly think through both cases while
changing/trying to understand the function.

Related: SYS#5560
Change-Id: I8eb8f24ad33a59de8fbaf512547d389ee86c13dc
2022-03-10 18:55:16 +01:00
Oliver Smith edc61b4519 bsc_nat_fsm: drop LOG_SCCP macro
After implementing more functionallity (see follow-up patches), it
became clear that this macro is not so useful:

* Using the macro creates unnecessary overhead,
  'LOG_SCCP(sccp_inst, peer_addr_in,' is much longer than 'LOGP('

* The RI and SSN are always the same, so it's not useful to print them
  all the time, this is the generated prefix:
  '(RI=SSN_PC,PC=0.23.3,SSN=BSSAP from CN)'

Related: SYS#5560
Change-Id: I49187d4e3d804c4786ee52eaebdd911e6c6cfa6c
2022-03-10 18:55:16 +01:00
Oliver Smith 6e4f7e9b2b bsc_nat_fsm: tweak forwarding log messages
Shorten them and don't use the LOG_SCCP macro anymore that will be
dropped in a follow-up patch. Change the level to DEBUG.

Related: SYS#5560
Change-Id: I85f65ad3c15a10958fbfe97aef00fc386e85ef63
2022-03-10 18:55:16 +01:00
Oliver Smith 1bee8ddae8 bsc_nat_fsm: log prim_name once, not in each case
Move the log message outside of the switch case to make it a bit
shorter. Use LOGP instead of LOG_SCCP, because the latter is about to
get removed in a follow-up patch.

Related: SYS#5560
Change-Id: I1f181ff38f86d83969da4e9d3da72dd9d69d298a
2022-03-10 18:55:16 +01:00
Oliver Smith 122beff8bb treewide: tweak includes
Categorize includes by:
* (library includes)
* Osmocom includes except for OsmoBSCNAT
* OsmoBSCNAT includes

Order the includes in each category alphabetically, and remove empty
lines between them. This allows me to keep them consistent, and with
empty lines removed between these categories it doesn't look
inconsistent if there is only one include from two categories in one
file, but multiple includes from the same category in another file.

While at it, also have one empty line after the license header in all
c, h files, and one after the includes.

Related: SYS#5560
Change-Id: I1a7b95ccb0c87fd53645c72f0c02449e8403043b
2022-03-10 18:52:31 +01:00
Oliver Smith f0a26d8ecc bsc_nat_fsm: move conn.ind before conn.conf
conn.ind happens before conn.conf, so use the same order in the switch
statement.

Related: SYS#5560
Change-Id: Ibdb5a9b092ab481f35cf5920f3635fdf4a9b85c2
2022-03-10 17:19:22 +01:00
Oliver Smith d586b71e8b bsc_nat_sccp_inst: store ss7_inst
Get ss7_inst once and store it inside bsc_nat_sccp_inst to avoid
multiple calls to osmo_ss7_instance_find().

Related: SYS#5560
Change-Id: I9a8b69fb3df17c85a67958fbca88948573d39694
2022-03-10 17:19:16 +01:00
Oliver Smith 399df14b6d bsc_nat_sccp_inst: rename from bsc_nat_ss7_inst
This name seems more fitting, since the code mostly interacts with the
sccp addr and scu contained in the struct.

Related: SYS#5560
Change-Id: Id0f965811eff0eb7b387d5ae2eec2451d6d8e415
2022-03-10 13:28:23 +01:00
Oliver Smith f2fe7d626a bsc_nat_fsm: fix sccp_sap_get_peer_addr_in
Fix the logic to not always return src->local_sccp_addr. What we need to
know is the peer's address.

Related: SYS#5560
Change-Id: I0055c0fafe672db5ce7a616d94c8964e8d58968f
2022-03-10 13:28:18 +01:00
Oliver Smith 9acbb0b790 bsc_nat_fsm: initial conn-oriented forwarding
Implement a simple version of forwarding Connection Request, Connection
Confirm, Data Form, Released SCCP messages. This is still assuming that
there is just one BSC, one MSC, the same connection ID is used in RAN
and CN. Future patches will add a mapping between RAN and CN sides and
allow multiple BSCs.

With this patch it is possible to perform a call between two MS in the
following network structure:

  MS1 --.
        BTS --- BSC --- BSCNAT --- MSC
  MS2 --'

Related: SYS#5560
Change-Id: I3df79e4dfaa60f4fd098961ee57cda71e9773b82
2022-02-24 08:30:09 +01:00
Oliver Smith 2a1e1d0617 bsc_nat_fsm: split sccp_sap_get_peer_addr_out
Split this code into an extra function, as it will be used by other
message types in sccp_sap_up too (following patches).

Related: SYS#5560
Change-Id: I6bc59445d65f812ccd46eb33dd6cca6b34dd0867
2022-02-18 18:30:36 +01:00
Oliver Smith 6515a891af bsc_nat_fsm: rename vars to peer_addr_{in,out}
Only in connection-less messages, the called party address is always the
address of the receiving peer. Prepare for connection-oriented messages
by renaming:
  dest_called -> peer_addr_out
  peer_addr   -> peer_addr_in

Related: SYS#5560
Change-Id: Ib58a4e8eb8beca23cb9f11c46576f8b17bb66f3c
2022-02-18 18:29:09 +01:00
Oliver Smith 0108033823 bsc_nat_fsm: drop called addr verify
This is already done by the SCCP stack, as Harald explained it:
"Think of a TCP socket where you have already bound a socket and then
 still do recvmsg to check if the destination address is what you expect."

Related: SYS#5560
Change-Id: Id9bfbf38a61ef66a4246f752ef487d8a09fea173
2022-02-18 18:25:05 +01:00
Oliver Smith 445dc2483e bsc_nat_fsm: sccp_sap_up: err if not implemented
Make it more obvious if a message is ignored, because it is not
implemented.

Related: SYS#5560
Change-Id: Ibc71e6aaed4fd51d090ab31fc3e49f3a82111506
2022-02-18 13:27:26 +01:00
Oliver Smith b80f2c33c8 bsc_nat_fsm: fix SSN of OsmoBSCNAT-CN
Related: SYS#5560
Change-Id: Ic0e64e002bccf1115cc53566bdab9d84dc680b03
2022-02-18 13:27:11 +01:00
Oliver Smith ba1f0d0691 bsc_nat_fsm: initial msc <> bsc msg forwarding
Add an initial implementation of sccp_sap_up, that assumes one BSC and
one MSC, and successfully forwards RESET and RESET ACK between both.

Related: SYS#5560
Depends: libosmo-sccp I0f38b0d038b0dd8cd355e7284e5b56d438811bd9
Change-Id: I4af398bb433341a98f818822e6c3af28b6d9dacd
2022-02-01 12:07:52 +01:00
Oliver Smith eefcdf8ed3 bsc_nat_fsm: fix SSN of OsmoBSCNAT-RAN
Related: SYS#5560
Change-Id: I0491ba90d28eea6f10d8d6f98a00d3dd6c698476
2022-01-31 18:51:22 +01:00
Oliver Smith 6afc0e3314 vty: use osmo_ss7_vty_go_parent
Remove unnecessary bsc_nat_vty_go_parent function, and use
osmo_ss7_vty_go_parent instead. Without the latter, it segfaults while
attempting to parse a config segment like this:

  cs7 instance 0
   point-code 0.23.3
   asp asp-clnt-OsmoBSCNAT-CN 2905 0 m3ua
    remote-ip 127.0.0.1
    local-ip 127.0.0.3
   sccp-address msc  # segfault here, vty->index == NULL
    routing-indicator PC
    point-code 0.23.1

Related: SYS#5560
Related: https://gerrit.osmocom.org/c/osmo-bsc-nat/+/26659/comment/c99b8cca_865449aa/
Change-Id: Iee6ece062f11694acb771463be7effb7342e92f2
2022-01-31 18:51:22 +01:00
Oliver Smith 8f7b750b22 Add bsc_nat fsm
Create the initial FSM that starts and stops two SS7 instances (one for
CN, one for RAN), and binds an sccp user to each.

Related: SYS#5560
Depends: libosmocore I81c64a7ae440304522c2179c212023a566ddced8
Change-Id: I7d52fa649c397582b18a1a7dcc40bb407f3b2c97
2022-01-31 18:50:59 +01:00
Oliver Smith d9c34fdc44 osmo-bsc-nat/bsc_nat.c: fix missing include
Related: SYS#5560
Change-Id: Ibd30d36eed1a734da25ab3491a4846dd6b70a244
2022-01-31 14:25:35 +01:00
Oliver Smith 5704c7e2ce Add signal handler
Related: OS#2545
Change-Id: I303e9275a2f1f6f2da742089d079ba604ee5a36b
2021-12-23 10:47:26 +01:00
Oliver Smith ff32401af3 Add command-line options
Related: OS#2545
Change-Id: I41bca9e1b88bb130870d078ed3f499e39e0bf5d3
2021-12-23 10:47:26 +01:00
Oliver Smith c448efb3aa Add vty interface
Related: OS#2545
Change-Id: I6f2d8d1d62b97be471ebcf1bb14aac0b895833d1
2021-12-23 10:47:26 +01:00
Oliver Smith 6a2ac0a0d5 Add project skeleton
It was decided to write OsmoBSCNAT with 3GPP AoIP support from scratch,
in a separate repository from OsmoBSC. The previous codebase was too
heavily tied into legacy SCCPlite code and had been removed from
osmo-bsc.git in Ia05dc76336a64a7f08962843b9a7cc19f2c83387.

Related: OS#2545
Change-Id: Iae5d37483dcb9db00578d5c9cd1736f08754a65e
2021-12-23 10:47:21 +01:00