| #include <osmocom/sgsn/gprs_gmm_attach.h> |
| |
| #include <osmocom/gsm/protocol/gsm_04_08_gprs.h> |
| #include <osmocom/sgsn/debug.h> |
| #include <osmocom/sgsn/gprs_gmm.h> |
| #include <osmocom/sgsn/sgsn.h> |
| |
| #define X(s) (1 << (s)) |
| |
| static int require_identity_imei = 1; |
| static int require_auth = 1; |
| |
| static void st_init(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| { |
| struct sgsn_mm_ctx *ctx = fi->priv; |
| struct msgb *attach_req = data; |
| |
| /* we can run st_init multiple times */ |
| if (ctx->gmm_att_req.attach_req) |
| msgb_free(ctx->gmm_att_req.attach_req); |
| |
| ctx->gmm_att_req.attach_req = msgb_copy(attach_req, "Attach Request"); |
| ctx->auth_state = SGSN_AUTH_UNKNOWN; |
| ctx->gmm_att_req.auth_reattempt = 0; |
| |
| /* |
| * TODO: remove pending_req as soon the sgsn_auth code doesn't depend |
| * on it. |
| * pending_req must be set, even this fsm doesn't use it, because |
| * the sgsn_auth code is using this too |
| */ |
| ctx->pending_req = GSM48_MT_GMM_ATTACH_REQ; |
| |
| if (require_identity_imei) { |
| ctx->gmm_att_req.id_type = GSM_MI_TYPE_IMEI; |
| osmo_fsm_inst_state_chg(fi, ST_IDENTIY, sgsn->cfg.timers.T3370, 3370); |
| } else if (!strlen(ctx->imsi)) { |
| ctx->gmm_att_req.id_type = GSM_MI_TYPE_IMSI; |
| osmo_fsm_inst_state_chg(fi, ST_IDENTIY, sgsn->cfg.timers.T3370, 3370); |
| } else if (require_auth) |
| osmo_fsm_inst_state_chg(fi, ST_AUTH, sgsn->cfg.timers.T3360, 3360); |
| else |
| osmo_fsm_inst_state_chg(fi, ST_ACCEPT, sgsn->cfg.timers.T3350, 3350); |
| } |
| |
| static void st_identity_on_enter(struct osmo_fsm_inst *fi, uint32_t prev_state) |
| { |
| struct sgsn_mm_ctx *ctx = fi->priv; |
| int ret = 0; |
| |
| ctx->num_T_exp = 0; |
| |
| switch (ctx->gmm_att_req.id_type) { |
| case GSM_MI_TYPE_IMEI: |
| case GSM_MI_TYPE_IMSI: |
| break; |
| default: |
| /* TODO logging */ |
| osmo_fsm_inst_dispatch(fi, E_REJECT, NULL); |
| return; |
| } |
| |
| ctx->t3370_id_type = ctx->gmm_att_req.id_type; |
| ret = gsm48_tx_gmm_id_req(ctx, ctx->gmm_att_req.id_type); |
| if (ret < 0) { |
| LOGPFSM(fi, "Can not send tx_gmm_id %d.\n", ret); |
| osmo_fsm_inst_dispatch(fi, E_REJECT, NULL); |
| } |
| } |
| |
| static void st_identity(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| { |
| struct sgsn_mm_ctx *ctx = fi->priv; |
| |
| OSMO_ASSERT(event == E_IDEN_RESP_RECV); |
| |
| /* check if we received a identity response */ |
| long type = (long) data; |
| switch (type) { |
| case GSM_MI_TYPE_IMEI: |
| case GSM_MI_TYPE_IMSI: |
| break; |
| default: |
| LOGMMCTXP(LOGL_ERROR, ctx, "Unknown mi type: 0x%lx, rejecting MS.\n", type); |
| osmo_fsm_inst_dispatch(fi, E_REJECT, (void *) GMM_CAUSE_NET_FAIL); |
| return; |
| } |
| |
| if (type != ctx->gmm_att_req.id_type) { |
| /* ignore wrong package */ |
| /* TODO logging */ |
| return; |
| } |
| |
| if (type == GSM_MI_TYPE_IMEI && !strlen(ctx->imsi)) { |
| ctx->gmm_att_req.id_type = GSM_MI_TYPE_IMSI; |
| osmo_fsm_inst_state_chg(fi, ST_IDENTIY, sgsn->cfg.timers.T3370, 3370); |
| } else if (require_auth) |
| osmo_fsm_inst_state_chg(fi, ST_AUTH, sgsn->cfg.timers.T3360, 3360); |
| else |
| osmo_fsm_inst_state_chg(fi, ST_ACCEPT, sgsn->cfg.timers.T3350, 3350); |
| } |
| |
| static void st_auth_on_enter(struct osmo_fsm_inst *fi, uint32_t prev_state) |
| { |
| struct sgsn_mm_ctx *ctx = fi->priv; |
| enum sgsn_auth_state auth_state; |
| |
| ctx->num_T_exp = 0; |
| |
| /* TODO: remove this layer violation. Don't parse any auth_policy here |
| * The correct way would be to ask the SGSN is this mmctx has to be auth |
| * regardless of the state. |
| * Otherwise someone else could steal the TLLI and just use it without further |
| * auth. |
| */ |
| if (sgsn->cfg.auth_policy != SGSN_AUTH_POLICY_REMOTE) { |
| /* we can "trust" sgsn_auth_state as long it's not remote */ |
| auth_state = sgsn_auth_state(ctx); |
| } else { |
| auth_state = ctx->auth_state; |
| } |
| |
| switch(auth_state) { |
| case SGSN_AUTH_UMTS_RESYNC: /* ask the vlr for a new vector to match the simcards seq */ |
| case SGSN_AUTH_UNKNOWN: /* the SGSN doesn know this MS */ |
| osmo_fsm_inst_state_chg(fi, ST_ASK_VLR, sgsn->cfg.timers.T3350, 3350); |
| break; |
| case SGSN_AUTH_REJECTED: |
| /* TODO: correct GMM cause */ |
| osmo_fsm_inst_dispatch(fi, E_REJECT, (void *) GMM_CAUSE_GPRS_NOTALLOWED); |
| break; |
| case SGSN_AUTH_ACCEPTED: |
| osmo_fsm_inst_state_chg(fi, ST_ACCEPT, sgsn->cfg.timers.T3350, 3350); |
| break; |
| case SGSN_AUTH_AUTHENTICATE: |
| if (ctx->auth_triplet.key_seq == GSM_KEY_SEQ_INVAL) { |
| /* invalid key material */ |
| osmo_fsm_inst_state_chg(fi, ST_ASK_VLR, sgsn->cfg.timers.T3350, 3350); |
| } |
| |
| struct gsm_auth_tuple *at = &ctx->auth_triplet; |
| if (gsm48_tx_gmm_auth_ciph_req(ctx, &at->vec, at->key_seq, |
| false) < 0) { |
| /* network failure */ |
| osmo_fsm_inst_dispatch(fi, E_REJECT, (void *) GMM_CAUSE_NET_FAIL); |
| } |
| ctx->gmm_att_req.auth_reattempt++; |
| break; |
| } |
| } |
| |
| static void st_auth(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| { |
| struct sgsn_mm_ctx *ctx = fi->priv; |
| |
| switch (event) { |
| case E_AUTH_RESP_RECV_SUCCESS: |
| sgsn_auth_request(ctx); |
| osmo_fsm_inst_state_chg(fi, ST_ACCEPT, sgsn->cfg.timers.T3350, 3350); |
| break; |
| case E_AUTH_RESP_RECV_RESYNC: |
| if (ctx->gmm_att_req.auth_reattempt <= 1) |
| osmo_fsm_inst_state_chg(fi, ST_ASK_VLR, sgsn->cfg.timers.T3350, 3350); |
| else |
| osmo_fsm_inst_dispatch(fi, E_REJECT, (void *) GMM_CAUSE_SYNC_FAIL); |
| break; |
| } |
| } |
| |
| static void st_accept_on_enter(struct osmo_fsm_inst *fi, uint32_t prev_state) |
| { |
| struct sgsn_mm_ctx *ctx = fi->priv; |
| |
| ctx->num_T_exp = 0; |
| |
| /* TODO: remove pending_req as soon the sgsn_auth code doesn't depend on it */ |
| ctx->pending_req = 0; |
| gsm48_tx_gmm_att_ack(ctx); |
| } |
| |
| static void st_accept(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| { |
| struct sgsn_mm_ctx *ctx = fi->priv; |
| |
| switch(event) { |
| case E_ATTACH_COMPLETE_RECV: |
| /* TODO: #ifdef ! PTMSI_ALLOC is not supported */ |
| extract_subscr_msisdn(ctx); |
| extract_subscr_hlr(ctx); |
| osmo_fsm_inst_state_chg(fi, ST_INIT, 0, 0); |
| break; |
| } |
| } |
| |
| static void st_reject(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| { |
| struct sgsn_mm_ctx *ctx = fi->priv; |
| long reject_cause = (long) data; |
| |
| if (reject_cause != GMM_DISCARD_MS_WITHOUT_REJECT) |
| gsm48_tx_gmm_att_rej(ctx, (uint8_t) reject_cause); |
| |
| sgsn_mm_ctx_cleanup_free(ctx); |
| } |
| |
| static void st_ask_vlr_on_enter(struct osmo_fsm_inst *fi, uint32_t prev_state) |
| { |
| struct sgsn_mm_ctx *ctx = fi->priv; |
| |
| /* FIXME: remove this layer violation. |
| * The VLR should send the message to the HLR and not the rx function |
| * gsm48_rx_gmm_auth_ciph_fail. Because gmm_auth_ciph_fail already send a |
| * message to the HLR, we don't send here a request. */ |
| if (ctx->auth_state == SGSN_AUTH_UMTS_RESYNC) |
| return; |
| |
| /* ask the auth layer for more data */ |
| sgsn_auth_request(ctx); |
| } |
| |
| static void st_ask_vlr(struct osmo_fsm_inst *fi, uint32_t event, void *data) |
| { |
| switch(event) { |
| case E_VLR_ANSWERED: |
| osmo_fsm_inst_state_chg(fi, ST_AUTH, sgsn->cfg.timers.T3360, 3360); |
| break; |
| } |
| } |
| |
| static struct osmo_fsm_state gmm_attach_req_fsm_states[] = { |
| /* default state for non-DTX and DTX when SPEECH is in progress */ |
| [ST_INIT] = { |
| .in_event_mask = X(E_ATTACH_REQ_RECV), |
| .out_state_mask = X(ST_INIT) | X(ST_IDENTIY) | X(ST_AUTH) | X(ST_ACCEPT), |
| .name = "Init", |
| .action = st_init, |
| }, |
| [ST_ASK_VLR] = { |
| .in_event_mask = X(E_VLR_ANSWERED), |
| .out_state_mask = X(ST_INIT) | X(ST_AUTH) | X(ST_ACCEPT) | X(ST_REJECT), |
| .name = "AskVLR", |
| .onenter = st_ask_vlr_on_enter, |
| .action = st_ask_vlr, |
| }, |
| [ST_IDENTIY] = { |
| .in_event_mask = X(E_IDEN_RESP_RECV), |
| .out_state_mask = X(ST_INIT) | X(ST_AUTH) | X(ST_ACCEPT) | X(ST_IDENTIY) | X(ST_REJECT), |
| .onenter = st_identity_on_enter, |
| .name = "CheckIdentity", |
| .action = st_identity, |
| }, |
| [ST_AUTH] = { |
| .in_event_mask = X(E_AUTH_RESP_RECV_SUCCESS) | X(E_AUTH_RESP_RECV_RESYNC), |
| .out_state_mask = X(ST_INIT) | X(ST_AUTH) | X(ST_ACCEPT) | X(ST_ASK_VLR) | X(ST_REJECT), |
| .name = "Authenticate", |
| .onenter = st_auth_on_enter, |
| .action = st_auth, |
| }, |
| [ST_ACCEPT] = { |
| .in_event_mask = X(E_ATTACH_COMPLETE_RECV), |
| .out_state_mask = X(ST_INIT) | X(ST_REJECT), |
| .name = "WaitAttachComplete", |
| .onenter = st_accept_on_enter, |
| .action = st_accept, |
| }, |
| [ST_REJECT] = { |
| .in_event_mask = X(E_REJECT), |
| .out_state_mask = X(ST_INIT), |
| .name = "Reject", |
| .action = st_reject, |
| }, |
| }; |
| |
| const struct value_string gmm_attach_req_fsm_event_names[] = { |
| { E_ATTACH_REQ_RECV, "Received an attach request" }, |
| { E_IDEN_RESP_RECV, "Identity Request received" }, |
| { E_AUTH_RESP_RECV_SUCCESS, "Authentication Response received" }, |
| { E_AUTH_RESP_RECV_RESYNC, "Authentication Failure with resync received" }, |
| { E_ATTACH_ACCEPTED, "Attach accepted" }, |
| { E_ATTACH_ACCEPT_SENT, "Attach accept sent" }, |
| { E_ATTACH_COMPLETE_RECV, "Attach complete received." }, |
| { E_REJECT, "Reject the MS"}, |
| { E_VLR_ANSWERED, "VLR answered"}, |
| { 0, NULL } |
| }; |
| |
| void gmm_attach_allstate_action(struct osmo_fsm_inst *fi, uint32_t event, void *data) { |
| struct sgsn_mm_ctx *ctx = fi->priv; |
| struct msgb *new_attach_req = data; |
| |
| switch (event) { |
| case E_ATTACH_REQ_RECV: |
| switch (fi->state) { |
| case ST_INIT: |
| case ST_REJECT: |
| st_init(fi, event, data); |
| break; |
| |
| case ST_ACCEPT: |
| /* TODO: drop all state (e.g. PDP Ctx) and do this procedure */ |
| osmo_fsm_inst_state_chg(fi, ST_INIT, 0, 0); |
| st_init(fi, event, data); |
| break; |
| |
| case ST_ASK_VLR: |
| case ST_AUTH: |
| case ST_IDENTIY: |
| case ST_RETRIEVE_AUTH: |
| /* 04.08 4.7.3.1.6 d) Abnormal Case |
| * Only do action if Req IEs differs. */ |
| if (ctx->gmm_att_req.attach_req && |
| gprs_gmm_attach_req_ies(new_attach_req, ctx->gmm_att_req.attach_req)) { |
| osmo_fsm_inst_state_chg(fi, ST_INIT, 0, 0); |
| st_init(fi, event, data); |
| } |
| break; |
| } |
| break; |
| case E_REJECT: |
| if (fi->state != ST_REJECT) |
| osmo_fsm_inst_state_chg(fi, ST_REJECT, 0, 0); |
| st_reject(fi, event, data); |
| break; |
| } |
| } |
| |
| int gmm_attach_timer_cb(struct osmo_fsm_inst *fi) |
| { |
| struct sgsn_mm_ctx *ctx = fi->priv; |
| struct gsm_auth_tuple *at = &ctx->auth_triplet; |
| |
| ctx->num_T_exp++; |
| |
| switch(fi->state) { |
| case ST_ASK_VLR: |
| /* TODO: replace T3350 by a better timer or it's own |
| * re-use T3350 - not defined by standard */ |
| LOGMMCTXP(LOGL_ERROR, ctx, "HLR did not answer in time. Rejecting.\n"); |
| osmo_fsm_inst_dispatch(fi, E_REJECT, |
| (void *) GMM_CAUSE_NET_FAIL); |
| break; |
| case ST_IDENTIY: |
| /* T3370 */ |
| if (ctx->num_T_exp >= 5) { |
| osmo_fsm_inst_dispatch(fi, E_REJECT, |
| (void *) GMM_CAUSE_MS_ID_NOT_DERIVED); |
| break; |
| } |
| gsm48_tx_gmm_id_req(ctx, ctx->gmm_att_req.id_type); |
| osmo_timer_schedule(&fi->timer, sgsn->cfg.timers.T3370, 0); |
| break; |
| case ST_AUTH: |
| /* T3360 */ |
| if (ctx->num_T_exp >= 5) { |
| osmo_fsm_inst_dispatch(fi, E_REJECT, (void *) GMM_DISCARD_MS_WITHOUT_REJECT); |
| break; |
| } |
| gsm48_tx_gmm_auth_ciph_req(ctx, &at->vec, at->key_seq, false); |
| osmo_timer_schedule(&fi->timer, sgsn->cfg.timers.T3360, 0); |
| break; |
| case ST_ACCEPT: |
| /* T3350 */ |
| if (ctx->num_T_exp >= 5) { |
| osmo_fsm_inst_dispatch(fi, E_REJECT, (void *) GMM_DISCARD_MS_WITHOUT_REJECT); |
| break; |
| } |
| gsm48_tx_gmm_att_ack(ctx); |
| osmo_timer_schedule(&fi->timer, sgsn->cfg.timers.T3350, 0); |
| break; |
| } |
| |
| return 0; |
| } |
| |
| struct osmo_fsm gmm_attach_req_fsm = { |
| .name = "GMM_ATTACH_REQ_FSM", |
| .states = gmm_attach_req_fsm_states, |
| .num_states = ARRAY_SIZE(gmm_attach_req_fsm_states), |
| .event_names = gmm_attach_req_fsm_event_names, |
| .allstate_event_mask = X(E_REJECT) | X(E_ATTACH_REQ_RECV), |
| .allstate_action = gmm_attach_allstate_action, |
| .log_subsys = DMM, |
| .timer_cb = gmm_attach_timer_cb, |
| }; |
| |
| static __attribute__((constructor)) void gprs_gmm_fsm_init(void) |
| { |
| osmo_fsm_register(&gmm_attach_req_fsm); |
| } |
| |
| void gmm_att_req_free(struct sgsn_mm_ctx *mm) { |
| if (mm->gmm_att_req.fsm) |
| osmo_fsm_inst_free(mm->gmm_att_req.fsm); |
| |
| if (mm->gmm_att_req.attach_req) |
| msgb_free(mm->gmm_att_req.attach_req); |
| } |