/* GSM 04.07 Transaction handling */ /* (C) 2009 by Harald Welte * All Rights Reserved * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License as published by * the Free Software Foundation; either version 3 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 Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public License * along with this program. If not, see . * */ #include #include #include #include #include #include #include #include #include #include #include void *tall_trans_ctx; void _gsm48_cc_trans_free(struct gsm_trans *trans); void _gsm411_sms_trans_free(struct gsm_trans *trans); void _gsm911_nc_ss_trans_free(struct gsm_trans *trans); struct gsm_trans *trans_find_by_type(const struct msc_a *msc_a, enum trans_type type) { struct gsm_trans *trans; struct gsm_network *net = msc_a_net(msc_a); struct vlr_subscr *vsub = msc_a_vsub(msc_a); llist_for_each_entry(trans, &net->trans_list, entry) { if (trans->vsub == vsub && trans->type == type) return trans; } return NULL; } /*! Find a transaction in connection for given protocol + transaction ID * \param[in] conn Connection in which we want to find transaction * \param[in] proto Protocol of transaction * \param[in] trans_id Transaction ID of transaction * \returns Matching transaction, if any */ struct gsm_trans *trans_find_by_id(const struct msc_a *msc_a, enum trans_type type, uint8_t trans_id) { struct gsm_trans *trans; struct gsm_network *net = msc_a_net(msc_a); struct vlr_subscr *vsub = msc_a_vsub(msc_a); llist_for_each_entry(trans, &net->trans_list, entry) { if (trans->vsub == vsub && trans->type == type && trans->transaction_id == trans_id) return trans; } return NULL; } /*! Find a transaction by call reference * \param[in] net Network in which we should search * \param[in] callref Call Reference of transaction * \returns Matching transaction, if any */ struct gsm_trans *trans_find_by_callref(const struct gsm_network *net, uint32_t callref) { struct gsm_trans *trans; llist_for_each_entry(trans, &net->trans_list, entry) { if (trans->callref == callref) return trans; } return NULL; } /*! Find a transaction by SM-RP-MR (RP Message Reference) * \param[in] net Network in which we should search * \param[in] vsub Subscriber for which we should search * \param[in] sm_rp_mr RP Message Reference (see GSM TS 04.11, section 8.2.3) * \returns Matching transaction, NULL otherwise */ struct gsm_trans *trans_find_by_sm_rp_mr(const struct gsm_network *net, const struct vlr_subscr *vsub, uint8_t sm_rp_mr) { struct gsm_trans *trans; llist_for_each_entry(trans, &net->trans_list, entry) { if (trans->vsub == vsub && trans->type == TRANS_SMS && trans->sms.sm_rp_mr == sm_rp_mr) return trans; } return NULL; } static const char *trans_vsub_use(enum trans_type type) { return get_value_string_or_null(trans_type_names, type) ? : "trans-type-unknown"; } /*! Allocate a new transaction and add it to network list * \param[in] net Netwokr in which we allocate transaction * \param[in] subscr Subscriber for which we allocate transaction * \param[in] protocol Protocol (CC/SMS/...) * \param[in] callref Call Reference * \returns Transaction */ struct gsm_trans *trans_alloc(struct gsm_network *net, struct vlr_subscr *vsub, enum trans_type type, uint8_t trans_id, uint32_t callref) { int subsys = trans_log_subsys(type); struct gsm_trans *trans; /* a valid subscriber is indispensable */ if (vsub == NULL) { LOGP(subsys, LOGL_ERROR, "unable to alloc transaction, invalid subscriber (NULL)\n"); return NULL; } trans = talloc(tall_trans_ctx, struct gsm_trans); if (!trans) return NULL; *trans = (struct gsm_trans){ .vsub = vsub, .type = type, .log_subsys = subsys, .transaction_id = trans_id, .callref = callref, .net = net, /* empty bearer_cap: make sure the speech_ver array is empty */ .bearer_cap = { .speech_ver = { -1 }, }, }; vlr_subscr_get(vsub, trans_vsub_use(type)); llist_add_tail(&trans->entry, &net->trans_list); LOG_TRANS(trans, LOGL_DEBUG, "New transaction\n"); return trans; } /*! Release a transaction * \param[in] trans Transaction to be released */ void trans_free(struct gsm_trans *trans) { const char *usage_token; struct msc_a *msc_a; LOG_TRANS(trans, LOGL_DEBUG, "Freeing transaction\n"); switch (trans->type) { case TRANS_CC: _gsm48_cc_trans_free(trans); usage_token = MSC_A_USE_CC; break; case TRANS_SMS: _gsm411_sms_trans_free(trans); usage_token = MSC_A_USE_SMS; break; case TRANS_USSD: _gsm911_nc_ss_trans_free(trans); usage_token = MSC_A_USE_NC_SS; break; case TRANS_SILENT_CALL: trans_silent_call_free(trans); usage_token = MSC_A_USE_SILENT_CALL; break; default: usage_token = NULL; break; } if (trans->paging_request) { paging_request_remove(trans->paging_request); trans->paging_request = NULL; } if (trans->vsub) { vlr_subscr_put(trans->vsub, trans_vsub_use(trans->type)); trans->vsub = NULL; } msc_a = trans->msc_a; trans->msc_a = NULL; llist_del(&trans->entry); talloc_free(trans); if (msc_a && usage_token) msc_a_put(msc_a, usage_token); } /*! allocate an unused transaction ID for the given subscriber * in the given protocol using TI flag = 0 (allocated by us). * See GSM 04.07, section 11.2.3.1.3 "Transaction identifier". * \param[in] net GSM network * \param[in] subscr Subscriber for which to assign a new TID * \param[in] protocol Protocol of to be assigned TID */ int trans_assign_trans_id(const struct gsm_network *net, const struct vlr_subscr *vsub, enum trans_type type) { struct gsm_trans *trans; unsigned int used_tid_bitmask = 0; int i, j, h; uint8_t proto = trans_type_to_gsm48_proto(type); /* generate bitmask of already-used TIDs for this (subscr,proto) */ llist_for_each_entry(trans, &net->trans_list, entry) { if (trans->vsub != vsub || proto != trans_type_to_gsm48_proto(trans->type) || trans->transaction_id == TRANS_ID_UNASSIGNED) continue; used_tid_bitmask |= (1 << trans->transaction_id); } /* find a new one, trying to go in a 'circular' pattern */ for (h = 6; h > 0; h--) if (used_tid_bitmask & (1 << h)) break; for (i = 0; i < 7; i++) { j = (h + i) % 7; if ((used_tid_bitmask & (1 << j)) == 0) return j; } return -1; } /*! Check if we have any transaction for given connection * \param[in] conn Connection to check * \returns transaction pointer if found, NULL otherwise */ struct gsm_trans *trans_has_conn(const struct msc_a *msc_a) { struct gsm_trans *trans; struct gsm_network *net = msc_a_net(msc_a); llist_for_each_entry(trans, &net->trans_list, entry) if (trans->msc_a == msc_a) return trans; return NULL; } /*! Free all transactions associated with a connection, presumably when the * conn is being closed. The transaction code will inform the CC or SMS * facilities, which will then send the necessary release indications. * \param[in] conn Connection that is going to be closed. */ void trans_conn_closed(const struct msc_a *msc_a) { /* As part of the CC REL_IND the remote leg might be released and this * will trigger another call to trans_free. This is something the llist * macro can not handle and we need to re-iterate the list every time. */ struct gsm_trans *trans; while ((trans = trans_has_conn(msc_a))) trans_free(trans); } const struct value_string trans_type_names[] = { { TRANS_CC, "CC" }, { TRANS_SMS, "SMS" }, { TRANS_USSD, "NCSS" }, { TRANS_SILENT_CALL, "silent-call" }, {} }; uint8_t trans_type_to_gsm48_proto(enum trans_type type) { switch (type) { case TRANS_CC: case TRANS_SILENT_CALL: return GSM48_PDISC_CC; case TRANS_SMS: return GSM48_PDISC_SMS; case TRANS_USSD: return GSM48_PDISC_NC_SS; default: return GSM48_PDISC_TEST; } } const char *trans_name(const struct gsm_trans *trans) { static char namebuf[32]; if (!trans) return "NULL"; switch (trans->type) { case TRANS_CC: snprintf(namebuf, sizeof(namebuf), "%s:%s", trans_type_name(trans->type), gsm48_cc_state_name(trans->cc.state)); return namebuf; default: return trans_type_name(trans->type); } }