diff options
| author | Jacob Erlbeck <jerlbeck@sysmocom.de> | 2014-09-30 13:49:43 +0200 |
|---|---|---|
| committer | Jacob Erlbeck <jerlbeck@sysmocom.de> | 2014-10-27 11:59:28 +0100 |
| commit | c37ef6cd0e535558b1cc672aa3964eeb506b3f25 (patch) | |
| tree | e578c0edacae26f6f01a68706296e235dc19d875 /openbsc/src/gprs/gb_proxy_tlli.c | |
| parent | 91e9f555b6a091663c192c9cd3b8d022a2690eed (diff) | |
gbproxy: Patch BSSGP P-TMSI in PAGING PS messages
Currently the P-TMSI IE in PAGING_PS is not patched.
This commit adds code to patch BSSGP P-TMSI IE in
gbproxy_patch_bssgp independently from the P-TMSI patching at the LLC
layer. It also extends gbproxy_update_link_state_dl to use the IMSI
to find the link_info if the TLLI is not present in the message.
Note that the spec (GSM 08.18, 7.2) requires to use of the P-TMSI
instead of the IMSI to select the MS if that IE is available.
Nevertheless as long as the IMSI is always present in downlink BSSGP
messages and as long as the optional P-TMSI refers to the same MS
(which is the case currently), this is not an issue.
Sponsored-by: On-Waves ehf
Diffstat (limited to 'openbsc/src/gprs/gb_proxy_tlli.c')
| -rw-r--r-- | openbsc/src/gprs/gb_proxy_tlli.c | 28 |
1 files changed, 25 insertions, 3 deletions
diff --git a/openbsc/src/gprs/gb_proxy_tlli.c b/openbsc/src/gprs/gb_proxy_tlli.c index 467006e87..54e41e9e0 100644 --- a/openbsc/src/gprs/gb_proxy_tlli.c +++ b/openbsc/src/gprs/gb_proxy_tlli.c @@ -542,6 +542,30 @@ struct gbproxy_link_info *gbproxy_update_link_state_ul( return link_info; } +static struct gbproxy_link_info *gbproxy_get_link_info_dl( + struct gbproxy_peer *peer, + struct gprs_gb_parse_context *parse_ctx) +{ + struct gbproxy_link_info *link_info = NULL; + + /* Which key to use depends on its availability only, if that fails, do + * not retry it with another key (e.g. IMSI). */ + if (parse_ctx->tlli_enc) + link_info = gbproxy_link_info_by_sgsn_tlli(peer, parse_ctx->tlli, + parse_ctx->peer_nsei); + + /* TODO: Get link_info by (SGSN) P-TMSI if that is available (see + * GSM 08.18, 7.2) instead of using the IMSI as key. */ + else if (parse_ctx->imsi) + link_info = gbproxy_link_info_by_imsi( + peer, parse_ctx->imsi, parse_ctx->imsi_len); + + if (link_info) + link_info->is_deregistered = 0; + + return link_info; +} + struct gbproxy_link_info *gbproxy_update_link_state_dl( struct gbproxy_peer *peer, time_t now, @@ -549,9 +573,7 @@ struct gbproxy_link_info *gbproxy_update_link_state_dl( { struct gbproxy_link_info *link_info = NULL; - if (parse_ctx->tlli_enc) - link_info = gbproxy_link_info_by_sgsn_tlli( - peer, parse_ctx->tlli, parse_ctx->peer_nsei); + link_info = gbproxy_get_link_info_dl(peer, parse_ctx); if (parse_ctx->tlli_enc && parse_ctx->new_ptmsi_enc && link_info) { /* A new P-TMSI has been signalled in the message, |