diff options
| author | Harald Welte <laforge@osmocom.org> | 2021-01-28 19:13:19 +0100 |
|---|---|---|
| committer | Harald Welte <laforge@osmocom.org> | 2021-01-28 19:14:32 +0100 |
| commit | e0876bda2689015109e57abe38ade9c6ebb5a211 (patch) | |
| tree | ec82fe46fba7a901a62f91af26bc03d0ff8acc5f | |
| parent | 21afdf9a32be2b61a31f1ec0ecbd9bc76135cb17 (diff) | |
gbproxy: Avoid depending on any of the SGSN code
The last remaining functin of the SGSN code base we used was
gprs_gb_parse_tlli().
Let's simply copy this function over and become self-contained.
This would allow migrating osmo-gbproxy to a separate repository.
Change-Id: I6f3f86581b47ad71a3d97f07611a2e2709876d69
| -rw-r--r-- | src/gbproxy/Makefile.am | 4 | ||||
| -rw-r--r-- | src/gbproxy/gb_proxy.c | 41 |
2 files changed, 41 insertions, 4 deletions
diff --git a/src/gbproxy/Makefile.am b/src/gbproxy/Makefile.am index f8a877328..1500e1173 100644 --- a/src/gbproxy/Makefile.am +++ b/src/gbproxy/Makefile.am @@ -30,10 +30,6 @@ osmo_gbproxy_SOURCES = \ gb_proxy_peer.c \ $(NULL) osmo_gbproxy_LDADD = \ - $(top_builddir)/src/gprs/gprs_gb_parse.o \ - $(top_builddir)/src/gprs/gprs_llc_parse.o \ - $(top_builddir)/src/gprs/crc24.o \ - $(top_builddir)/src/gprs/gprs_utils.o \ $(LIBOSMOCORE_LIBS) \ $(LIBOSMOGSM_LIBS) \ $(LIBOSMOVTY_LIBS) \ diff --git a/src/gbproxy/gb_proxy.c b/src/gbproxy/gb_proxy.c index 1d29b6436..c882eb068 100644 --- a/src/gbproxy/gb_proxy.c +++ b/src/gbproxy/gb_proxy.c @@ -136,6 +136,47 @@ static int gbprox_relay2sgsn(struct gbproxy_config *cfg, struct msgb *old_msg, } #endif +/*! Determine the TLLI from the given BSSGP message. + * \param[in] bssgp pointer to start of BSSGP header + * \param[in] bssgp_len length of BSSGP message in octets + * \param[out] tlli TLLI (if any) in host byte order + * \returns 1 if TLLI found; 0 if none found; negative on parse error */ +int gprs_gb_parse_tlli(const uint8_t *bssgp, size_t bssgp_len, uint32_t *tlli) +{ + const struct bssgp_normal_hdr *bgph; + uint8_t pdu_type; + + if (bssgp_len < sizeof(struct bssgp_normal_hdr)) + return -EINVAL; + + bgph = (struct bssgp_normal_hdr *)bssgp; + pdu_type = bgph->pdu_type; + + if (pdu_type == BSSGP_PDUT_UL_UNITDATA || + pdu_type == BSSGP_PDUT_DL_UNITDATA) { + const struct bssgp_ud_hdr *budh = (struct bssgp_ud_hdr *)bssgp; + if (bssgp_len < sizeof(struct bssgp_ud_hdr)) + return -EINVAL; + *tlli = osmo_load32be((const uint8_t *)&budh->tlli); + return 1; + } else { + const uint8_t *data = bgph->data; + size_t data_len = bssgp_len - sizeof(*bgph); + struct tlv_parsed tp; + + if (bssgp_tlv_parse(&tp, data, data_len) < 0) + return -EINVAL; + + if (TLVP_PRESENT(&tp, BSSGP_IE_TLLI)) { + *tlli = osmo_load32be(TLVP_VAL(&tp, BSSGP_IE_TLLI)); + return 1; + } + } + + /* No TLLI present in message */ + return 0; +} + /* feed a message down the NSE */ static int gbprox_relay2nse(struct msgb *old_msg, struct gbproxy_nse *nse, uint16_t ns_bvci) |