move openbsc/* to repos root

This is the first step in creating this repository from the legacy openbsc.git.

Like all other Osmocom repositories, keep the autoconf and automake files in
the repository root. openbsc.git has been the sole exception, which ends now.

Change-Id: I9c6f2a448d9cb1cc088cf1cf6918b69d7e69b4e7

1 files changed, 312 insertions, 0 deletions

diff --git a/src/gprs/sgsn_auth.c b/src/gprs/sgsn_auth.c
new file mode 100644
index 000000000..a64339c3e
--- /dev/null
+++ b/src/gprs/sgsn_auth.c
@@ -0,0 +1,312 @@
+/* MS authorization and subscriber data handling */
+
+/* (C) 2009-2010 by Harald Welte <laforge@gnumonks.org>
+ *
+ * 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 <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <osmocom/gsm/protocol/gsm_04_08_gprs.h>
+#include <osmocom/core/utils.h>
+#include <openbsc/sgsn.h>
+#include <openbsc/gprs_sgsn.h>
+#include <openbsc/gprs_gmm.h>
+#include <openbsc/gprs_subscriber.h>
+#include <openbsc/debug.h>
+
+const struct value_string auth_state_names[] = {
+	{ SGSN_AUTH_ACCEPTED,	"accepted"},
+	{ SGSN_AUTH_REJECTED,	"rejected"},
+	{ SGSN_AUTH_UNKNOWN,	"unknown"},
+	{ SGSN_AUTH_AUTHENTICATE, "authenticate" },
+	{ SGSN_AUTH_UMTS_RESYNC, "UMTS-resync" },
+	{ 0, NULL }
+};
+
+const struct value_string *sgsn_auth_state_names = auth_state_names;
+
+void sgsn_auth_init(void)
+{
+	INIT_LLIST_HEAD(&sgsn->cfg.imsi_acl);
+}
+
+/* temporary IMSI ACL hack */
+struct imsi_acl_entry *sgsn_acl_lookup(const char *imsi, struct sgsn_config *cfg)
+{
+	struct imsi_acl_entry *acl;
+	llist_for_each_entry(acl, &cfg->imsi_acl, list) {
+		if (!strcmp(imsi, acl->imsi))
+			return acl;
+	}
+	return NULL;
+}
+
+int sgsn_acl_add(const char *imsi, struct sgsn_config *cfg)
+{
+	struct imsi_acl_entry *acl;
+
+	if (sgsn_acl_lookup(imsi, cfg))
+		return -EEXIST;
+
+	acl = talloc_zero(NULL, struct imsi_acl_entry);
+	if (!acl)
+		return -ENOMEM;
+	osmo_strlcpy(acl->imsi, imsi, sizeof(acl->imsi));
+
+	llist_add(&acl->list, &cfg->imsi_acl);
+
+	return 0;
+}
+
+int sgsn_acl_del(const char *imsi, struct sgsn_config *cfg)
+{
+	struct imsi_acl_entry *acl;
+
+	acl = sgsn_acl_lookup(imsi, cfg);
+	if (!acl)
+		return -ENODEV;
+
+	llist_del(&acl->list);
+	talloc_free(acl);
+
+	return 0;
+}
+
+enum sgsn_auth_state sgsn_auth_state(struct sgsn_mm_ctx *mmctx)
+{
+	char mccmnc[16];
+	int check_net = 0;
+	int check_acl = 0;
+
+	OSMO_ASSERT(mmctx);
+
+	switch (sgsn->cfg.auth_policy) {
+	case SGSN_AUTH_POLICY_OPEN:
+		return SGSN_AUTH_ACCEPTED;
+
+	case SGSN_AUTH_POLICY_CLOSED:
+		check_net = 1;
+		check_acl = 1;
+		break;
+
+	case SGSN_AUTH_POLICY_ACL_ONLY:
+		check_acl = 1;
+		break;
+
+	case SGSN_AUTH_POLICY_REMOTE:
+		if (!mmctx->subscr)
+			return mmctx->auth_state;
+
+		if (mmctx->subscr->flags & GPRS_SUBSCRIBER_UPDATE_PENDING_MASK)
+			return mmctx->auth_state;
+
+		if (sgsn->cfg.require_authentication &&
+		    (!mmctx->is_authenticated ||
+		     mmctx->subscr->sgsn_data->auth_triplets_updated))
+			return SGSN_AUTH_AUTHENTICATE;
+
+		if (mmctx->subscr->authorized)
+			return SGSN_AUTH_ACCEPTED;
+
+		return SGSN_AUTH_REJECTED;
+	}
+
+	if (!strlen(mmctx->imsi)) {
+		LOGMMCTXP(LOGL_NOTICE, mmctx,
+			  "Missing IMSI, authorization state not known\n");
+		return SGSN_AUTH_UNKNOWN;
+	}
+
+	if (check_net) {
+		/* We simply assume that the IMSI exists, as long as it is part
+		 * of 'our' network */
+		snprintf(mccmnc, sizeof(mccmnc), "%03d%02d",
+			 mmctx->ra.mcc, mmctx->ra.mnc);
+		if (strncmp(mccmnc, mmctx->imsi, 5) == 0)
+			return SGSN_AUTH_ACCEPTED;
+	}
+
+	if (check_acl && sgsn_acl_lookup(mmctx->imsi, &sgsn->cfg))
+		return SGSN_AUTH_ACCEPTED;
+
+	return SGSN_AUTH_REJECTED;
+}
+
+/*
+ * This function is directly called by e.g. the GMM layer. It returns either
+ * after calling sgsn_auth_update directly or after triggering an asynchronous
+ * procedure which will call sgsn_auth_update later on.
+ */
+int sgsn_auth_request(struct sgsn_mm_ctx *mmctx)
+{
+	struct gprs_subscr *subscr;
+	struct gsm_auth_tuple *at;
+	int need_update_location;
+	int rc;
+
+	LOGMMCTXP(LOGL_DEBUG, mmctx, "Requesting authorization\n");
+
+	if (sgsn->cfg.auth_policy != SGSN_AUTH_POLICY_REMOTE) {
+		sgsn_auth_update(mmctx);
+		return 0;
+	}
+
+	need_update_location = sgsn->cfg.require_update_location &&
+		(mmctx->subscr == NULL ||
+		 mmctx->pending_req == GSM48_MT_GMM_ATTACH_REQ);
+
+	/* This has the side effect of registering the subscr with the mmctx */
+	subscr = gprs_subscr_get_or_create_by_mmctx(mmctx);
+	gprs_subscr_put(subscr);
+
+	OSMO_ASSERT(mmctx->subscr != NULL);
+
+	if (sgsn->cfg.require_authentication && !mmctx->is_authenticated) {
+		/* Find next tuple */
+		at = sgsn_auth_get_tuple(mmctx, mmctx->auth_triplet.key_seq);
+
+		if (!at) {
+			/* No valid tuple found, request fresh ones */
+			mmctx->auth_triplet.key_seq = GSM_KEY_SEQ_INVAL;
+			LOGMMCTXP(LOGL_INFO, mmctx,
+				  "Requesting authentication tuples\n");
+			rc = gprs_subscr_request_auth_info(mmctx, NULL, NULL);
+			if (rc >= 0)
+				return 0;
+
+			return rc;
+		}
+
+		mmctx->auth_triplet = *at;
+	} else if (need_update_location) {
+		LOGMMCTXP(LOGL_INFO, mmctx,
+			  "Missing information, requesting subscriber data\n");
+		rc = gprs_subscr_request_update_location(mmctx);
+		if (rc >= 0)
+			return 0;
+
+		return rc;
+	}
+
+	sgsn_auth_update(mmctx);
+	return 0;
+}
+
+void sgsn_auth_update(struct sgsn_mm_ctx *mmctx)
+{
+	enum sgsn_auth_state auth_state;
+	struct gprs_subscr *subscr = mmctx->subscr;
+	struct gsm_auth_tuple *at;
+	int gmm_cause;
+
+	auth_state = sgsn_auth_state(mmctx);
+
+	LOGMMCTXP(LOGL_DEBUG, mmctx, "Updating authorization (%s -> %s)\n",
+		  get_value_string(sgsn_auth_state_names, mmctx->auth_state),
+		  get_value_string(sgsn_auth_state_names, auth_state));
+
+	if (auth_state == SGSN_AUTH_UNKNOWN && subscr &&
+	    !(subscr->flags & GPRS_SUBSCRIBER_UPDATE_PENDING_MASK)) {
+		/* Reject requests if gprs_subscr_request_update_location fails */
+		LOGMMCTXP(LOGL_ERROR, mmctx,
+			  "Missing information, authorization not possible\n");
+		auth_state = SGSN_AUTH_REJECTED;
+	}
+
+	if (auth_state == SGSN_AUTH_AUTHENTICATE &&
+	    mmctx->auth_triplet.key_seq == GSM_KEY_SEQ_INVAL) {
+		/* The current tuple is not valid, but we are possibly called
+		 * because new auth tuples have been received */
+		at = sgsn_auth_get_tuple(mmctx, mmctx->auth_triplet.key_seq);
+		if (!at) {
+			LOGMMCTXP(LOGL_ERROR, mmctx,
+				  "Missing auth tuples, authorization not possible\n");
+			auth_state = SGSN_AUTH_REJECTED;
+		} else {
+			mmctx->auth_triplet = *at;
+		}
+	}
+
+	if (mmctx->auth_state == auth_state)
+		return;
+
+	LOGMMCTXP(LOGL_INFO, mmctx, "Got authorization update: state %s -> %s\n",
+		  get_value_string(sgsn_auth_state_names, mmctx->auth_state),
+		  get_value_string(sgsn_auth_state_names, auth_state));
+
+	mmctx->auth_state = auth_state;
+
+	switch (auth_state) {
+	case SGSN_AUTH_AUTHENTICATE:
+		if (subscr)
+			subscr->sgsn_data->auth_triplets_updated = 0;
+
+		gsm0408_gprs_authenticate(mmctx);
+		break;
+	case SGSN_AUTH_ACCEPTED:
+		gsm0408_gprs_access_granted(mmctx);
+		break;
+	case SGSN_AUTH_REJECTED:
+		gmm_cause =
+			subscr ? subscr->sgsn_data->error_cause :
+			SGSN_ERROR_CAUSE_NONE;
+
+		if (subscr && (subscr->flags & GPRS_SUBSCRIBER_CANCELLED) != 0)
+			gsm0408_gprs_access_cancelled(mmctx, gmm_cause);
+		else
+			gsm0408_gprs_access_denied(mmctx, gmm_cause);
+		break;
+	default:
+		break;
+	}
+}
+
+struct gsm_auth_tuple *sgsn_auth_get_tuple(struct sgsn_mm_ctx *mmctx,
+					   unsigned key_seq)
+{
+	unsigned count;
+	unsigned idx;
+	struct gsm_auth_tuple *at = NULL;
+
+	struct sgsn_subscriber_data *sdata;
+
+	if (!mmctx->subscr)
+		return NULL;
+
+	if (key_seq == GSM_KEY_SEQ_INVAL)
+		/* Start with 0 after increment module array size */
+		idx = ARRAY_SIZE(sdata->auth_triplets) - 1;
+	else
+		idx = key_seq;
+
+	sdata = mmctx->subscr->sgsn_data;
+
+	/* Find next tuple */
+	for (count = ARRAY_SIZE(sdata->auth_triplets); count > 0; count--) {
+		idx = (idx + 1) % ARRAY_SIZE(sdata->auth_triplets);
+
+		if (sdata->auth_triplets[idx].key_seq == GSM_KEY_SEQ_INVAL)
+			continue;
+
+		if (sdata->auth_triplets[idx].use_count == 0) {
+			at = &sdata->auth_triplets[idx];
+			at->use_count = 1;
+			return at;
+		}
+	}
+
+	return NULL;
+}