laforge has submitted this change. ( https://gerrit.osmocom.org/c/osmo-sgsn/+/39246?usp=email )
Change subject: gprs_gmm_util: add parsing of GMM Attach Requests ......................................................................
gprs_gmm_util: add parsing of GMM Attach Requests
This will be used in the following commit.
Change-Id: I4a82e0c4070da982efd6c2f15fd145393423772b --- M include/osmocom/sgsn/gprs_gmm_util.h M src/sgsn/gprs_gmm_util.c 2 files changed, 137 insertions(+), 2 deletions(-)
Approvals: Jenkins Builder: Verified laforge: Looks good to me, approved pespin: Looks good to me, but someone else must approve
diff --git a/include/osmocom/sgsn/gprs_gmm_util.h b/include/osmocom/sgsn/gprs_gmm_util.h index c136cce..1ffede6 100644 --- a/include/osmocom/sgsn/gprs_gmm_util.h +++ b/include/osmocom/sgsn/gprs_gmm_util.h @@ -4,6 +4,7 @@ #include <stdint.h>
#include <osmocom/gsm/gsm23003.h> +#include <osmocom/gsm/gsm48.h> #include <osmocom/gsm/tlv.h>
struct msgb; @@ -22,4 +23,20 @@ struct tlv_parsed tlv; };
-int gprs_gmm_parse_ra_upd_req(struct msgb *msg, struct gprs_gmm_ra_upd_req *rau_req); +struct gprs_gmm_att_req { + uint8_t skip_ind; /* 10.3.1 */ + uint8_t attach_type; /* 10.5.5.2 */ + bool follow_up_req; /* 10.5.5.2 */ + uint8_t cksq; /* 10.5.1.2 */ + uint16_t drx_parms; /* 10.5.5.6 */ + struct osmo_mobile_identity mi; /* 10.5.1.4 */ + struct osmo_routing_area_id old_rai; /* 10.5.5.15 */ + uint8_t *ms_network_cap; /* 10.5.5.12 */ + uint8_t ms_network_cap_len; + uint8_t *ms_radio_cap; /* 10.5.5.12a */ + uint8_t ms_radio_cap_len; + struct tlv_parsed tlv; +}; + +int gprs_gmm_parse_ra_upd_req(const struct msgb *msg, struct gprs_gmm_ra_upd_req *rau_req); +int gprs_gmm_parse_att_req(const struct msgb *msg, struct gprs_gmm_att_req *att_req); diff --git a/src/sgsn/gprs_gmm_util.c b/src/sgsn/gprs_gmm_util.c index 4f61669..01c94a7 100644 --- a/src/sgsn/gprs_gmm_util.c +++ b/src/sgsn/gprs_gmm_util.c @@ -29,6 +29,7 @@ #include <osmocom/gsm/protocol/gsm_04_08_gprs.h> #include <osmocom/gsm/tlv.h>
+#include <osmocom/sgsn/debug.h> #include <osmocom/sgsn/gprs_gmm_util.h>
const struct tlv_definition gsm48_gmm_ie_tlvdef = { @@ -62,12 +63,129 @@ }, };
+/* Minimum length of a GMM Attach Request (only L3/GMM) */ +#define GSM48_GMM_ATT_REQ_MIN_LEN 25 +const struct tlv_definition gsm48_gmm_att_ie_tlvdef = { + .def = { + [GSM48_IE_GMM_PTMSI_SIG] = { TLV_TYPE_FIXED, 3 }, + [GSM48_IE_GMM_TIMER_READY] = { TLV_TYPE_TV, 1 }, + [GSM48_IE_GMM_TMSI_STATUS] = { TLV_TYPE_SINGLE_TV, 1 }, + [GSM48_IE_GMM_PS_LCS_CAPA] = { TLV_TYPE_TLV, 0 }, + [GSM48_IE_GMM_MS_CLASSMARK2] = { TLV_TYPE_TLV, 3 }, + [GSM48_IE_GMM_MS_CLASSMARK3] = { TLV_TYPE_TLV, 0 }, + [GSM48_IE_GMM_SUPP_CODEC_LIST] = { TLV_TYPE_TLV, 3 }, + [GSM48_IE_GMM_UE_NET_CAP] = { TLV_TYPE_TLV, 2 }, + [GSM48_IE_GMM_ADD_IDENTITY] = { TLV_TYPE_TLV, 0 }, + [GSM48_IE_GMM_RAI2] = { TLV_TYPE_TLV, 0 }, + [GSM48_IE_GMM_VD_PREF_UE_USAGE] = { TLV_TYPE_TLV, 1 }, + [GSM48_IE_GMM_DEVICE_PROP] = { TLV_TYPE_SINGLE_TV, 1 }, + [GSM48_IE_GMM_PTMSI_TYPE] = { TLV_TYPE_SINGLE_TV, 1 }, + [GSM48_IE_GMM_MS_NET_FEAT_SUP] = { TLV_TYPE_SINGLE_TV, 1 }, + [GSM48_IE_GMM_ADD_UPDATE_TYPE] = { TLV_TYPE_SINGLE_TV, 1 }, + [GSM48_IE_GMM_TMSI_BASED_NRI_C] = { TLV_TYPE_TLV, 4 }, + [GMM48_IE_GMM_TIMER_T3324] = { TLV_TYPE_TLV, 3 }, + [GSM48_IE_GMM_TIMER_T3312_EXT] = { TLV_TYPE_TLV, 3 }, + [GSM48_IE_GMM_EXT_DRX_PARAMS] = { TLV_TYPE_TLV, 3 }, + } +}; + + +/*! Parse 24.008 9.4.1 Attach Request + * \param[in] msg l3 pointers must point to gmm. + * \param[out] rau_req parsed RA update request + * \returns 0 on success or GMM cause + */ +int gprs_gmm_parse_att_req(const struct msgb *msg, struct gprs_gmm_att_req *att_req) +{ + uint8_t *cur, len; + size_t mandatory_fields_len; + struct gsm48_hdr *gh; + int ret; + + OSMO_ASSERT(msg); + OSMO_ASSERT(att_req); + + memset(att_req, 0, sizeof(struct gprs_gmm_att_req)); + /* all mandatory fields */ + if (msgb_l3len(msg) < GSM48_GMM_ATT_REQ_MIN_LEN) + return GMM_CAUSE_PROTO_ERR_UNSPEC; + + gh = (struct gsm48_hdr *) msgb_gmmh(msg); + cur = gh->data; + + att_req->skip_ind = gh->proto_discr >> 4; + + /* LV: MS network cap 10.5.5.12 */ + len = *cur++; + if (msgb_l3len(msg) < (len + 21 + (cur - msgb_gmmh(msg)))) + return GMM_CAUSE_PROTO_ERR_UNSPEC; + /* MS network cap can't be empty */ + if (len == 0) + return GMM_CAUSE_INV_MAND_INFO; + + att_req->ms_network_cap = cur; + att_req->ms_network_cap_len = len; + cur += len; + + /* V: Update Type 10.5.5.18 */ + att_req->attach_type = *cur & 0x07; + att_req->follow_up_req = !!(*cur & 0x08); + + /* V: GPRS Ciphering Key Sequence 10.5.1.2 */ + att_req->cksq = *cur >> 4; + cur++; + + /* V: DRX parameter 10.5.5.6 */ + att_req->drx_parms = osmo_load16le(cur); + cur += 2; + + /* LV: Mobile identity 10.5.1.4 */ + len = *cur++; + if (msgb_l3len(msg) < (len + 12 + (cur - msgb_gmmh(msg)))) + return GMM_CAUSE_PROTO_ERR_UNSPEC; + ret = osmo_mobile_identity_decode(&att_req->mi, cur, len, false); + if (ret) + return GMM_CAUSE_PROTO_ERR_UNSPEC; + cur += len; + + /* V: Old routing area identification 10.5.5.15 */ + osmo_routing_area_id_decode(&att_req->old_rai, cur, 6); + cur += 6; + + /* LV: MS radio cap 10.5.5.12a */ + len = *cur++; + if (msgb_l3len(msg) < (len + (cur - msgb_gmmh(msg)))) + return GMM_CAUSE_PROTO_ERR_UNSPEC; + /* 24.008 Rel 17 specifies min 5, but SGSN will still work with 4 */ + if (len < 4) + return GMM_CAUSE_INV_MAND_INFO; + + att_req->ms_radio_cap = cur; + att_req->ms_radio_cap_len = len; + cur += len; + + mandatory_fields_len = (cur - msgb_gmmh(msg)); + if (msgb_l3len(msg) == mandatory_fields_len) + return 0; + + ret = tlv_parse(&att_req->tlv, &gsm48_gmm_att_ie_tlvdef, + cur, msgb_l3len(msg) - mandatory_fields_len, 0, 0); + + /* gracefully handle unknown IEs (partial parsing) */ + if (ret < 0 && ret != OSMO_TLVP_ERR_UNKNOWN_TLV_TYPE) { + LOGP(DMM, LOGL_NOTICE, "%s(): tlv_parse() failed (%d)\n", __func__, ret); + return GMM_CAUSE_COND_IE_ERR; + } + + return 0; +} + /*! Parse 24.008 9.4.14 RAU Request * \param[in] msg l3 pointers must point to gmm. * \param[out] rau_req parsed RA update request * \returns 0 on success or GMM cause */ -int gprs_gmm_parse_ra_upd_req(struct msgb *msg, struct gprs_gmm_ra_upd_req *rau_req) +int gprs_gmm_parse_ra_upd_req(const struct msgb *msg, struct gprs_gmm_ra_upd_req *rau_req) { uint8_t *cur, len; size_t mandatory_fields_len;
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