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authorAlexander Couzens <lynxis@fe80.eu>2018-05-22 18:29:14 +0200
committerHarald Welte <laforge@gnumonks.org>2018-09-13 13:51:37 +0000
commitf7198d7dbb84d038a82eec5ad0b86f7f29ca411e (patch)
treeba6bdf8dbe9055009459ba28c900c98b5590656f
parent941ee147f92b6064b5e5feff166ecfb97cea85b1 (diff)
gprs_gmm: introduce a GMM Attach Request FSM
The old GMM Attach Request handling used a recursive function which can not handle certain states and is quite complex and hard to extend. The new FSM handles such request in a FSM and can be called multiple times. Change-Id: I58b9c17be9776a03bb2a5b21e99135cfefc8c912
-rw-r--r--include/osmocom/sgsn/Makefile.am1
-rw-r--r--include/osmocom/sgsn/gprs_gmm.h2
-rw-r--r--include/osmocom/sgsn/gprs_gmm_attach.h37
-rw-r--r--include/osmocom/sgsn/gprs_sgsn.h10
-rw-r--r--src/gprs/Makefile.am1
-rw-r--r--src/gprs/gprs_gmm.c47
-rw-r--r--src/gprs/gprs_gmm_attach.c398
-rw-r--r--src/gprs/gprs_sgsn.c6
-rw-r--r--tests/sgsn/Makefile.am1
9 files changed, 494 insertions, 9 deletions
diff --git a/include/osmocom/sgsn/Makefile.am b/include/osmocom/sgsn/Makefile.am
index 269cebcd..3b563c40 100644
--- a/include/osmocom/sgsn/Makefile.am
+++ b/include/osmocom/sgsn/Makefile.am
@@ -5,6 +5,7 @@ noinst_HEADERS = \
gb_proxy.h \
gprs_gb_parse.h \
gprs_gmm.h \
+ gprs_gmm_attach.h \
gprs_llc.h \
gprs_llc_xid.h \
gprs_sgsn.h \
diff --git a/include/osmocom/sgsn/gprs_gmm.h b/include/osmocom/sgsn/gprs_gmm.h
index d12eaf9b..ffcebd35 100644
--- a/include/osmocom/sgsn/gprs_gmm.h
+++ b/include/osmocom/sgsn/gprs_gmm.h
@@ -40,6 +40,8 @@ int gsm48_tx_gmm_att_rej(struct sgsn_mm_ctx *mm,
uint8_t gmm_cause);
int gsm48_tx_gmm_att_ack(struct sgsn_mm_ctx *mm);
+int gprs_gmm_attach_req_ies(struct msgb *a, struct msgb *b);
+
/* TODO: move extract_subscr_* when gsm48_gmm_authorize() got removed */
void extract_subscr_msisdn(struct sgsn_mm_ctx *ctx);
void extract_subscr_hlr(struct sgsn_mm_ctx *ctx);
diff --git a/include/osmocom/sgsn/gprs_gmm_attach.h b/include/osmocom/sgsn/gprs_gmm_attach.h
new file mode 100644
index 00000000..22fbd6f9
--- /dev/null
+++ b/include/osmocom/sgsn/gprs_gmm_attach.h
@@ -0,0 +1,37 @@
+#ifndef GPRS_GMM_ATTACH_H
+#define GPRS_GMM_ATTACH_H
+
+#include <osmocom/core/fsm.h>
+
+struct sgsn_mm_ctx;
+
+enum gmm_attach_req_fsm_states {
+ ST_INIT,
+ ST_IDENTIY,
+ ST_RETRIEVE_AUTH,
+ ST_AUTH,
+ ST_ASK_VLR,
+ ST_ACCEPT,
+ ST_REJECT
+};
+
+enum gmm_attach_req_fsm_events {
+ E_ATTACH_REQ_RECV,
+ E_IDEN_RESP_RECV,
+ E_AUTH_RESP_RECV_SUCCESS,
+ E_AUTH_RESP_RECV_RESYNC,
+ E_ATTACH_ACCEPTED,
+ E_ATTACH_ACCEPT_SENT,
+ E_ATTACH_COMPLETE_RECV,
+ E_REJECT,
+ E_VLR_ANSWERED,
+};
+
+#define GMM_DISCARD_MS_WITHOUT_REJECT -1
+
+extern const struct value_string gmm_attach_req_fsm_event_names[];
+extern struct osmo_fsm gmm_attach_req_fsm;
+
+void gmm_att_req_free(struct sgsn_mm_ctx *mm);
+
+#endif // GPRS_GMM_ATTACH_H
diff --git a/include/osmocom/sgsn/gprs_sgsn.h b/include/osmocom/sgsn/gprs_sgsn.h
index 6f16dc75..a5ca959a 100644
--- a/include/osmocom/sgsn/gprs_sgsn.h
+++ b/include/osmocom/sgsn/gprs_sgsn.h
@@ -4,6 +4,7 @@
#include <stdint.h>
#include <netinet/in.h>
+#include <osmocom/core/fsm.h>
#include <osmocom/core/timer.h>
#include <osmocom/gsm/gsm48.h>
@@ -168,6 +169,15 @@ struct sgsn_mm_ctx {
struct ranap_ue_conn_ctx *ue_ctx;
struct service_info service;
} iu;
+ struct {
+ struct osmo_fsm_inst *fsm;
+
+ /* when a second attach req arrives while in this procedure,
+ * the fsm needs to compare it against old to decide what to do */
+ struct msgb *attach_req;
+ uint32_t id_type;
+ bool auth_reattempt;
+ } gmm_att_req;
/* VLR number */
uint32_t new_sgsn_addr;
/* Authentication Triplet */
diff --git a/src/gprs/Makefile.am b/src/gprs/Makefile.am
index 46d94d45..0f7c5faa 100644
--- a/src/gprs/Makefile.am
+++ b/src/gprs/Makefile.am
@@ -59,6 +59,7 @@ osmo_gbproxy_LDADD = \
$(NULL)
osmo_sgsn_SOURCES = \
+ gprs_gmm_attach.c \
gprs_gmm.c \
gprs_sgsn.c \
gprs_sndcp.c \
diff --git a/src/gprs/gprs_gmm.c b/src/gprs/gprs_gmm.c
index bea63dc5..a363c709 100644
--- a/src/gprs/gprs_gmm.c
+++ b/src/gprs/gprs_gmm.c
@@ -59,6 +59,7 @@
#include <osmocom/sgsn/gprs_utils.h>
#include <osmocom/sgsn/gprs_subscriber.h>
#include <osmocom/sgsn/sgsn.h>
+#include <osmocom/sgsn/gprs_gmm_attach.h>
#include <osmocom/sgsn/signal.h>
#include <osmocom/sgsn/gprs_sndcp.h>
@@ -791,7 +792,7 @@ static int gsm48_rx_gmm_auth_ciph_resp(struct sgsn_mm_ctx *ctx,
/* FIXME: enable LLC cipheirng */
/* Check if we can let the mobile station enter */
- return gsm48_gmm_authorize(ctx);
+ return osmo_fsm_inst_dispatch(ctx->gmm_att_req.fsm, E_AUTH_RESP_RECV_SUCCESS, NULL);
}
/* Section 9.4.10: Authentication and Ciphering Failure */
@@ -836,7 +837,7 @@ static int gsm48_rx_gmm_auth_ciph_fail(struct sgsn_mm_ctx *ctx,
rc = gprs_subscr_request_auth_info(ctx, auts,
ctx->auth_triplet.vec.rand);
if (!rc)
- return 0;
+ return osmo_fsm_inst_dispatch(ctx->gmm_att_req.fsm, E_AUTH_RESP_RECV_RESYNC, NULL);
/* on error, fall through to send a reject */
LOGMMCTXP(LOGL_ERROR, ctx,
"Sending AUTS to HLR failed (rc = %d)\n", rc);
@@ -1107,7 +1108,10 @@ void gsm0408_gprs_authenticate(struct sgsn_mm_ctx *ctx)
{
ctx->sec_ctx = OSMO_AUTH_TYPE_NONE;
- gsm48_gmm_authorize(ctx);
+ if (ctx->gmm_att_req.fsm->state != ST_INIT)
+ osmo_fsm_inst_dispatch(ctx->gmm_att_req.fsm, E_VLR_ANSWERED, (void *) 0);
+ else
+ gsm48_gmm_authorize(ctx);
}
void gsm0408_gprs_access_granted(struct sgsn_mm_ctx *ctx)
@@ -1118,7 +1122,8 @@ void gsm0408_gprs_access_granted(struct sgsn_mm_ctx *ctx)
"Authorized, continuing procedure, IMSI=%s\n",
ctx->imsi);
/* Continue with the authorization */
- gsm48_gmm_authorize(ctx);
+ if (ctx->gmm_att_req.fsm->state != ST_INIT)
+ osmo_fsm_inst_dispatch(ctx->gmm_att_req.fsm, E_VLR_ANSWERED, (void *) 0);
break;
default:
LOGMMCTXP(LOGL_INFO, ctx,
@@ -1139,8 +1144,8 @@ void gsm0408_gprs_access_denied(struct sgsn_mm_ctx *ctx, int gmm_cause)
"with cause '%s' (%d)\n",
get_value_string(gsm48_gmm_cause_names, gmm_cause),
gmm_cause);
- gsm48_tx_gmm_att_rej(ctx, gmm_cause);
- mm_ctx_cleanup_free(ctx, "GPRS ATTACH REJECT");
+ if (ctx->gmm_att_req.fsm->state != ST_INIT)
+ osmo_fsm_inst_dispatch(ctx->gmm_att_req.fsm, E_REJECT, (void *) (long) gmm_cause);
break;
case GMM_REGISTERED_NORMAL:
case GMM_REGISTERED_SUSPENDED:
@@ -1183,6 +1188,7 @@ static int gsm48_rx_gmm_id_resp(struct sgsn_mm_ctx *ctx, struct msgb *msg)
{
struct gsm48_hdr *gh = (struct gsm48_hdr *) msgb_gmmh(msg);
uint8_t mi_type = gh->data[1] & GSM_MI_TYPE_MASK;
+ long mi_typel = mi_type;
char mi_string[GSM48_MI_SIZE];
gsm48_mi_to_string(mi_string, sizeof(mi_string), &gh->data[1], gh->data[0]);
@@ -1235,7 +1241,7 @@ static int gsm48_rx_gmm_id_resp(struct sgsn_mm_ctx *ctx, struct msgb *msg)
}
/* Check if we can let the mobile station enter */
- return gsm48_gmm_authorize(ctx);
+ return osmo_fsm_inst_dispatch(ctx->gmm_att_req.fsm, E_IDEN_RESP_RECV, (void *)mi_typel);
}
/* Allocate a new P-TMSI and change context state */
@@ -1425,8 +1431,8 @@ static int gsm48_rx_gmm_att_req(struct sgsn_mm_ctx *ctx, struct msgb *msg,
gprs_llgmm_assign(ctx->gb.llme, ctx->gb.tlli, ctx->gb.tlli_new);
}
- ctx->pending_req = GSM48_MT_GMM_ATTACH_REQ;
- return gsm48_gmm_authorize(ctx);
+ osmo_fsm_inst_dispatch(ctx->gmm_att_req.fsm, E_ATTACH_REQ_RECV, msg);
+ return 0;
err_inval:
LOGPC(DMM, LOGL_INFO, "\n");
@@ -1447,6 +1453,28 @@ rejected:
}
+
+/* Checks if two attach request contain the IEs and IE values
+ * return 0 if equal
+ * return -1 if error
+ * return 1 if unequal
+ *
+ * Only do a simple memcmp for now.
+ */
+int gprs_gmm_attach_req_ies(struct msgb *a, struct msgb *b)
+{
+ struct gsm48_hdr *gh_a = (struct gsm48_hdr *) msgb_gmmh(a);
+ struct gsm48_hdr *gh_b = (struct gsm48_hdr *) msgb_gmmh(b);
+
+#define GMM_ATTACH_REQ_LEN 26
+
+ /* there is the LLC FCS behind */
+ if (msgb_l3len(a) < GMM_ATTACH_REQ_LEN || msgb_l3len(b) < GMM_ATTACH_REQ_LEN)
+ return -1;
+
+ return !!memcmp(gh_a, gh_b, GMM_ATTACH_REQ_LEN);
+}
+
/* Section 4.7.4.1 / 9.4.5.2 MO Detach request */
static int gsm48_rx_gmm_det_req(struct sgsn_mm_ctx *ctx, struct msgb *msg)
{
@@ -2023,6 +2051,7 @@ static int gsm0408_rcv_gmm(struct sgsn_mm_ctx *mmctx, struct msgb *msg,
mmctx_set_mm_state(mmctx, MM_READY);
rc = 0;
+ osmo_fsm_inst_dispatch(mmctx->gmm_att_req.fsm, E_ATTACH_COMPLETE_RECV, 0);
memset(&sig_data, 0, sizeof(sig_data));
sig_data.mm = mmctx;
osmo_signal_dispatch(SS_SGSN, S_SGSN_ATTACH, &sig_data);
diff --git a/src/gprs/gprs_gmm_attach.c b/src/gprs/gprs_gmm_attach.c
new file mode 100644
index 00000000..272fec79
--- /dev/null
+++ b/src/gprs/gprs_gmm_attach.c
@@ -0,0 +1,398 @@
+#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);
+}
diff --git a/src/gprs/gprs_sgsn.c b/src/gprs/gprs_sgsn.c
index d8bca857..977ae489 100644
--- a/src/gprs/gprs_sgsn.c
+++ b/src/gprs/gprs_sgsn.c
@@ -40,6 +40,7 @@
#include <osmocom/sgsn/gprs_gmm.h>
#include <osmocom/sgsn/gprs_utils.h>
#include <osmocom/sgsn/signal.h>
+#include <osmocom/sgsn/gprs_gmm_attach.h>
#include <osmocom/sgsn/gprs_llc.h>
#include <pdp.h>
@@ -241,6 +242,7 @@ struct sgsn_mm_ctx *sgsn_mm_ctx_alloc_gb(uint32_t tlli,
talloc_free(ctx);
return NULL;
}
+ ctx->gmm_att_req.fsm = osmo_fsm_inst_alloc(&gmm_attach_req_fsm, ctx, ctx, LOGL_DEBUG, "gb_gmm_req");
INIT_LLIST_HEAD(&ctx->pdp_list);
llist_add(&ctx->list, &sgsn_mm_ctxts);
@@ -273,6 +275,7 @@ struct sgsn_mm_ctx *sgsn_mm_ctx_alloc_iu(void *uectx)
talloc_free(ctx);
return NULL;
}
+ ctx->gmm_att_req.fsm = osmo_fsm_inst_alloc(&gmm_attach_req_fsm, ctx, ctx, LOGL_DEBUG, "gb_gmm_req");
/* Need to get RAID from IU conn */
ctx->ra = ctx->iu.ue_ctx->ra_id;
@@ -350,6 +353,9 @@ void sgsn_mm_ctx_cleanup_free(struct sgsn_mm_ctx *mm)
gprs_subscr_put(subscr);
}
+ if (mm->gmm_att_req.fsm)
+ gmm_att_req_free(mm);
+
sgsn_mm_ctx_free(mm);
mm = NULL;
diff --git a/tests/sgsn/Makefile.am b/tests/sgsn/Makefile.am
index abcc3570..0eb21009 100644
--- a/tests/sgsn/Makefile.am
+++ b/tests/sgsn/Makefile.am
@@ -45,6 +45,7 @@ sgsn_test_LDADD = \
$(top_builddir)/src/gprs/gprs_llc.o \
$(top_builddir)/src/gprs/crc24.o \
$(top_builddir)/src/gprs/gprs_sndcp.o \
+ $(top_builddir)/src/gprs/gprs_gmm_attach.o \
$(top_builddir)/src/gprs/gprs_gmm.o \
$(top_builddir)/src/gprs/gprs_sgsn.o \
$(top_builddir)/src/gprs/sgsn_vty.o \