/* Osmocom Subscriber Update Protocol message encoder/decoder */ /* * (C) 2014 by sysmocom s.f.m.c. GmbH * (C) 2015 by Holger Hans Peter Freyther * (C) 2016 by Harald Welte * All Rights Reserved * * Author: Jacob Erlbeck * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 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 General Public License * along with this program. If not, see . * */ #include #include #include #include #include #include static int decode_pdp_info(uint8_t *data, size_t data_len, struct osmo_gsup_pdp_info *pdp_info) { int rc; uint8_t tag; uint8_t *value; size_t value_len; /* specific parts */ while (data_len > 0) { enum osmo_gsup_iei iei; rc = osmo_shift_tlv(&data, &data_len, &tag, &value, &value_len); if (rc < 0) return -GMM_CAUSE_PROTO_ERR_UNSPEC; iei = tag; switch (iei) { case OSMO_GSUP_PDP_CONTEXT_ID_IE: pdp_info->context_id = osmo_decode_big_endian(value, value_len); break; case OSMO_GSUP_PDP_TYPE_IE: pdp_info->pdp_type = osmo_decode_big_endian(value, value_len) & 0x0fff; break; case OSMO_GSUP_ACCESS_POINT_NAME_IE: pdp_info->apn_enc = value; pdp_info->apn_enc_len = value_len; break; case OSMO_GSUP_PDP_QOS_IE: pdp_info->qos_enc = value; pdp_info->qos_enc_len = value_len; break; default: LOGP(DLGSUP, LOGL_ERROR, "GSUP IE type %d not expected in PDP info\n", iei); continue; } } return 0; } static int decode_auth_info(uint8_t *data, size_t data_len, struct osmo_auth_vector *auth_vector) { int rc; uint8_t tag; uint8_t *value; size_t value_len; enum osmo_gsup_iei iei; uint8_t presence = 0; /* specific parts */ while (data_len > 0) { rc = osmo_shift_tlv(&data, &data_len, &tag, &value, &value_len); if (rc < 0) return -GMM_CAUSE_PROTO_ERR_UNSPEC; iei = tag; switch (iei) { case OSMO_GSUP_RAND_IE: if (value_len != sizeof(auth_vector->rand)) goto parse_error; memcpy(auth_vector->rand, value, value_len); presence |= (1 << 0); break; case OSMO_GSUP_SRES_IE: if (value_len != sizeof(auth_vector->sres)) goto parse_error; memcpy(auth_vector->sres, value, value_len); presence |= (1 << 1); break; case OSMO_GSUP_KC_IE: if (value_len != sizeof(auth_vector->kc)) goto parse_error; memcpy(auth_vector->kc, value, value_len); presence |= (1 << 2); break; case OSMO_GSUP_IK_IE: if (value_len != sizeof(auth_vector->ik)) goto parse_error; memcpy(auth_vector->ik, value, value_len); presence |= (1 << 4); break; case OSMO_GSUP_CK_IE: if (value_len != sizeof(auth_vector->ck)) goto parse_error; memcpy(auth_vector->ck, value, value_len); presence |= (1 << 5); break; case OSMO_GSUP_AUTN_IE: if (value_len != sizeof(auth_vector->autn)) goto parse_error; memcpy(auth_vector->autn, value, value_len); presence |= (1 << 6); break; case OSMO_GSUP_RES_IE: if (value_len > sizeof(auth_vector->res)) goto parse_error; memcpy(auth_vector->res, value, value_len); auth_vector->res_len = value_len; presence |= (1 << 7); break; default: LOGP(DLGSUP, LOGL_ERROR, "GSUP IE type %d not expected in PDP info\n", iei); continue; } } if (presence & 0x07) auth_vector->auth_types |= OSMO_AUTH_TYPE_GSM; if (presence & 0xf0) auth_vector->auth_types |= OSMO_AUTH_TYPE_UMTS; return 0; parse_error: LOGP(DLGSUP, LOGL_ERROR, "GSUP IE type %d, length %zu invalid in PDP info\n", iei, value_len); return -1; } /*! Decode (parse) a GSUP message * \param[in] const_data input data to be parsed * \param[in] data_len length of input (\a const_data) * \param[out] gsup_msg callee-allocated output data structure * \returns 0 on success; negative otherwise */ int osmo_gsup_decode(const uint8_t *const_data, size_t data_len, struct osmo_gsup_message *gsup_msg) { int rc; uint8_t tag; /* the shift/match functions expect non-const pointers, but we'll * either copy the data or cast pointers back to const before returning * them */ uint8_t *data = (uint8_t *)const_data; uint8_t *value; size_t value_len; static const struct osmo_gsup_pdp_info empty_pdp_info = {0}; static const struct osmo_auth_vector empty_auth_info = {{0}}; static const struct osmo_gsup_message empty_gsup_message = {0}; *gsup_msg = empty_gsup_message; /* generic part */ rc = osmo_shift_v_fixed(&data, &data_len, 1, &value); if (rc < 0) return -GMM_CAUSE_INV_MAND_INFO; gsup_msg->message_type = osmo_decode_big_endian(value, 1); rc = osmo_match_shift_tlv(&data, &data_len, OSMO_GSUP_IMSI_IE, &value, &value_len); if (rc <= 0) return -GMM_CAUSE_INV_MAND_INFO; if (value_len * 2 + 1 > sizeof(gsup_msg->imsi)) return -GMM_CAUSE_INV_MAND_INFO; /* Note that gsm48_decode_bcd_number expects the number of encoded IMSI * octets in the first octet. By coincidence (the TLV encoding) the byte * before the value part already contains this length so we can use it * here. */ OSMO_ASSERT(value[-1] == value_len); gsm48_decode_bcd_number(gsup_msg->imsi, sizeof(gsup_msg->imsi), value - 1, 0); /* specific parts */ while (data_len > 0) { enum osmo_gsup_iei iei; struct osmo_gsup_pdp_info pdp_info; struct osmo_auth_vector auth_info; rc = osmo_shift_tlv(&data, &data_len, &tag, &value, &value_len); if (rc < 0) return -GMM_CAUSE_PROTO_ERR_UNSPEC; iei = tag; switch (iei) { case OSMO_GSUP_IMSI_IE: case OSMO_GSUP_PDP_TYPE_IE: case OSMO_GSUP_ACCESS_POINT_NAME_IE: case OSMO_GSUP_SRES_IE: case OSMO_GSUP_KC_IE: LOGP(DLGSUP, LOGL_NOTICE, "GSUP IE type %d not expected (ignored)\n", iei); continue; case OSMO_GSUP_CAUSE_IE: gsup_msg->cause = osmo_decode_big_endian(value, value_len); break; case OSMO_GSUP_CANCEL_TYPE_IE: gsup_msg->cancel_type = osmo_decode_big_endian(value, value_len) + 1; break; case OSMO_GSUP_PDP_INFO_COMPL_IE: gsup_msg->pdp_info_compl = 1; break; case OSMO_GSUP_FREEZE_PTMSI_IE: gsup_msg->freeze_ptmsi = 1; break; case OSMO_GSUP_PDP_CONTEXT_ID_IE: /* When these IE appear in the top-level part of the * message, they are used by Delete Subscr Info to delete * single entries. We don't have an extra list for * these but use the PDP info list instead */ /* fall through */ case OSMO_GSUP_PDP_INFO_IE: if (gsup_msg->num_pdp_infos >= OSMO_GSUP_MAX_NUM_PDP_INFO) { LOGP(DLGSUP, LOGL_ERROR, "GSUP IE type %d (PDP_INFO) max exceeded\n", iei); return -GMM_CAUSE_COND_IE_ERR; } pdp_info = empty_pdp_info; if (iei == OSMO_GSUP_PDP_INFO_IE) { rc = decode_pdp_info(value, value_len, &pdp_info); if (rc < 0) return rc; pdp_info.have_info = 1; } else { pdp_info.context_id = osmo_decode_big_endian(value, value_len); } gsup_msg->pdp_infos[gsup_msg->num_pdp_infos++] = pdp_info; break; case OSMO_GSUP_AUTH_TUPLE_IE: if (gsup_msg->num_auth_vectors >= OSMO_GSUP_MAX_NUM_AUTH_INFO) { LOGP(DLGSUP, LOGL_ERROR, "GSUP IE type %d (AUTH_INFO) max exceeded\n", iei); return -GMM_CAUSE_INV_MAND_INFO; } auth_info = empty_auth_info; rc = decode_auth_info(value, value_len, &auth_info); if (rc < 0) return rc; gsup_msg->auth_vectors[gsup_msg->num_auth_vectors++] = auth_info; break; case OSMO_GSUP_AUTS_IE: if (value_len != 16) { LOGP(DLGSUP, LOGL_ERROR, "AUTS length != 16 received\n"); return -GMM_CAUSE_COND_IE_ERR; } gsup_msg->auts = value; break; case OSMO_GSUP_RAND_IE: if (value_len != 16) { LOGP(DLGSUP, LOGL_ERROR, "RAND length != 16 received\n"); return -GMM_CAUSE_COND_IE_ERR; } gsup_msg->rand = value; break; case OSMO_GSUP_MSISDN_IE: gsup_msg->msisdn_enc = value; gsup_msg->msisdn_enc_len = value_len; break; case OSMO_GSUP_HLR_NUMBER_IE: gsup_msg->hlr_enc = value; gsup_msg->hlr_enc_len = value_len; break; case OSMO_GSUP_CN_DOMAIN_IE: gsup_msg->cn_domain = *value; break; default: LOGP(DLGSUP, LOGL_NOTICE, "GSUP IE type %d unknown\n", iei); continue; } } return 0; } static void encode_pdp_info(struct msgb *msg, enum osmo_gsup_iei iei, const struct osmo_gsup_pdp_info *pdp_info) { uint8_t *len_field; size_t old_len; uint8_t u8; len_field = msgb_tlv_put(msg, iei, 0, NULL) - 1; old_len = msgb_length(msg); u8 = pdp_info->context_id; msgb_tlv_put(msg, OSMO_GSUP_PDP_CONTEXT_ID_IE, sizeof(u8), &u8); if (pdp_info->pdp_type) { msgb_tlv_put(msg, OSMO_GSUP_PDP_TYPE_IE, OSMO_GSUP_PDP_TYPE_SIZE, osmo_encode_big_endian(pdp_info->pdp_type | 0xf000, OSMO_GSUP_PDP_TYPE_SIZE)); } if (pdp_info->apn_enc) { msgb_tlv_put(msg, OSMO_GSUP_ACCESS_POINT_NAME_IE, pdp_info->apn_enc_len, pdp_info->apn_enc); } if (pdp_info->qos_enc) { msgb_tlv_put(msg, OSMO_GSUP_PDP_QOS_IE, pdp_info->qos_enc_len, pdp_info->qos_enc); } /* Update length field */ *len_field = msgb_length(msg) - old_len; } static void encode_auth_info(struct msgb *msg, enum osmo_gsup_iei iei, const struct osmo_auth_vector *auth_vector) { uint8_t *len_field; size_t old_len; len_field = msgb_tlv_put(msg, iei, 0, NULL) - 1; old_len = msgb_length(msg); if (auth_vector->auth_types & OSMO_AUTH_TYPE_GSM) { msgb_tlv_put(msg, OSMO_GSUP_RAND_IE, sizeof(auth_vector->rand), auth_vector->rand); msgb_tlv_put(msg, OSMO_GSUP_SRES_IE, sizeof(auth_vector->sres), auth_vector->sres); msgb_tlv_put(msg, OSMO_GSUP_KC_IE, sizeof(auth_vector->kc), auth_vector->kc); } if (auth_vector->auth_types & OSMO_AUTH_TYPE_UMTS) { msgb_tlv_put(msg, OSMO_GSUP_IK_IE, sizeof(auth_vector->ik), auth_vector->ik); msgb_tlv_put(msg, OSMO_GSUP_CK_IE, sizeof(auth_vector->ck), auth_vector->ck); msgb_tlv_put(msg, OSMO_GSUP_AUTN_IE, sizeof(auth_vector->autn), auth_vector->autn); msgb_tlv_put(msg, OSMO_GSUP_RES_IE, auth_vector->res_len, auth_vector->res); } /* Update length field */ *len_field = msgb_length(msg) - old_len; } /*! Encode a GSUP message * \param[out] msg message buffer to which encoded message is written * \param[in] gsup_msg \ref osmo_gsup_message data to be encoded */ void osmo_gsup_encode(struct msgb *msg, const struct osmo_gsup_message *gsup_msg) { uint8_t u8; int idx; uint8_t bcd_buf[GSM48_MI_SIZE] = {0}; size_t bcd_len; /* generic part */ OSMO_ASSERT(gsup_msg->message_type); msgb_v_put(msg, gsup_msg->message_type); bcd_len = gsm48_encode_bcd_number(bcd_buf, sizeof(bcd_buf), 0, gsup_msg->imsi); OSMO_ASSERT(bcd_len > 1); OSMO_ASSERT(bcd_len <= sizeof(bcd_buf)); /* Note that gsm48_encode_bcd_number puts the length into the first * octet. Since msgb_tlv_put will add this length byte, we'll have to * skip it */ msgb_tlv_put(msg, OSMO_GSUP_IMSI_IE, bcd_len - 1, &bcd_buf[1]); /* specific parts */ if (gsup_msg->msisdn_enc) msgb_tlv_put(msg, OSMO_GSUP_MSISDN_IE, gsup_msg->msisdn_enc_len, gsup_msg->msisdn_enc); if (gsup_msg->hlr_enc) msgb_tlv_put(msg, OSMO_GSUP_HLR_NUMBER_IE, gsup_msg->hlr_enc_len, gsup_msg->hlr_enc); if ((u8 = gsup_msg->cause)) msgb_tlv_put(msg, OSMO_GSUP_CAUSE_IE, sizeof(u8), &u8); if ((u8 = gsup_msg->cancel_type)) { u8 -= 1; msgb_tlv_put(msg, OSMO_GSUP_CANCEL_TYPE_IE, sizeof(u8), &u8); } if (gsup_msg->pdp_info_compl) msgb_tlv_put(msg, OSMO_GSUP_PDP_INFO_COMPL_IE, 0, &u8); if (gsup_msg->freeze_ptmsi) msgb_tlv_put(msg, OSMO_GSUP_FREEZE_PTMSI_IE, 0, &u8); for (idx = 0; idx < gsup_msg->num_pdp_infos; idx++) { const struct osmo_gsup_pdp_info *pdp_info; pdp_info = &gsup_msg->pdp_infos[idx]; if (pdp_info->context_id == 0) continue; if (pdp_info->have_info) { encode_pdp_info(msg, OSMO_GSUP_PDP_INFO_IE, pdp_info); } else { u8 = pdp_info->context_id; msgb_tlv_put(msg, OSMO_GSUP_PDP_CONTEXT_ID_IE, sizeof(u8), &u8); } } for (idx = 0; idx < gsup_msg->num_auth_vectors; idx++) { const struct osmo_auth_vector *auth_vector; auth_vector = &gsup_msg->auth_vectors[idx]; encode_auth_info(msg, OSMO_GSUP_AUTH_TUPLE_IE, auth_vector); } if (gsup_msg->auts) msgb_tlv_put(msg, OSMO_GSUP_AUTS_IE, 16, gsup_msg->auts); if (gsup_msg->rand) msgb_tlv_put(msg, OSMO_GSUP_RAND_IE, 16, gsup_msg->rand); if (gsup_msg->cn_domain) { uint8_t dn = gsup_msg->cn_domain; msgb_tlv_put(msg, OSMO_GSUP_CN_DOMAIN_IE, 1, &dn); } }