HS 2.0: CoA-Request processing for Terms and Conditions filtering

Extend RADIUS DAS to support CoA-Request packets for the case where the
HS 2.0 Terms And Conditions filtering VSA is used to remove filtering.

Signed-off-by: Jouni Malinen <jouni@codeaurora.org>

src/ap/hostapd.c

@@ -49,6 +49,7 @@
 #include "rrm.h"
 #include "fils_hlp.h"
 #include "acs.h"
+#include "hs20.h"
 
 
 static int hostapd_flush_old_stations(struct hostapd_data *hapd, u16 reason);
@@ -900,6 +901,48 @@ hostapd_das_disconnect(void *ctx, struct radius_das_attrs *attr)
 	return RADIUS_DAS_SUCCESS;
 }
 
+
+#ifdef CONFIG_HS20
+static enum radius_das_res
+hostapd_das_coa(void *ctx, struct radius_das_attrs *attr)
+{
+	struct hostapd_data *hapd = ctx;
+	struct sta_info *sta;
+	int multi;
+
+	if (hostapd_das_nas_mismatch(hapd, attr))
+		return RADIUS_DAS_NAS_MISMATCH;
+
+	sta = hostapd_das_find_sta(hapd, attr, &multi);
+	if (!sta) {
+		if (multi) {
+			wpa_printf(MSG_DEBUG,
+				   "RADIUS DAS: Multiple sessions match - not supported");
+			return RADIUS_DAS_MULTI_SESSION_MATCH;
+		}
+		wpa_printf(MSG_DEBUG, "RADIUS DAS: No matching session found");
+		return RADIUS_DAS_SESSION_NOT_FOUND;
+	}
+
+	wpa_printf(MSG_DEBUG, "RADIUS DAS: Found a matching session " MACSTR
+		   " - CoA", MAC2STR(sta->addr));
+
+	if (attr->hs20_t_c_filtering) {
+		if (attr->hs20_t_c_filtering[0] & BIT(0)) {
+			wpa_printf(MSG_DEBUG,
+				   "HS 2.0: Unexpected Terms and Conditions filtering required in CoA-Request");
+			return RADIUS_DAS_COA_FAILED;
+		}
+
+		hs20_t_c_filtering(hapd, sta, 0);
+	}
+
+	return RADIUS_DAS_SUCCESS;
+}
+#else /* CONFIG_HS20 */
+#define hostapd_das_coa NULL
+#endif /* CONFIG_HS20 */
+
 #endif /* CONFIG_NO_RADIUS */
 
 
@@ -1074,6 +1117,7 @@ static int hostapd_setup_bss(struct hostapd_data *hapd, int first)
 			conf->radius_das_require_message_authenticator;
 		das_conf.ctx = hapd;
 		das_conf.disconnect = hostapd_das_disconnect;
+		das_conf.coa = hostapd_das_coa;
 		hapd->radius_das = radius_das_init(&das_conf);
 		if (hapd->radius_das == NULL) {
 			wpa_printf(MSG_ERROR, "RADIUS DAS initialization "

src/ap/hs20.c

@@ -11,9 +11,11 @@
 
 #include "common.h"
 #include "common/ieee802_11_defs.h"
+#include "common/wpa_ctrl.h"
 #include "hostapd.h"
 #include "ap_config.h"
 #include "ap_drv_ops.h"
+#include "sta_info.h"
 #include "hs20.h"
 
 
@@ -218,3 +220,26 @@ int hs20_send_wnm_notification_t_c(struct hostapd_data *hapd,
 
 	return ret;
 }
+
+
+void hs20_t_c_filtering(struct hostapd_data *hapd, struct sta_info *sta,
+			int enabled)
+{
+	if (enabled) {
+		wpa_printf(MSG_DEBUG,
+			   "HS 2.0: Terms and Conditions filtering required for "
+			   MACSTR, MAC2STR(sta->addr));
+		sta->hs20_t_c_filtering = 1;
+		/* TODO: Enable firewall filtering for the STA */
+		wpa_msg(hapd->msg_ctx, MSG_INFO, HS20_T_C_FILTERING_ADD MACSTR,
+			MAC2STR(sta->addr));
+	} else {
+		wpa_printf(MSG_DEBUG,
+			   "HS 2.0: Terms and Conditions filtering not required for "
+			   MACSTR, MAC2STR(sta->addr));
+		sta->hs20_t_c_filtering = 0;
+		/* TODO: Disable firewall filtering for the STA */
+		wpa_msg(hapd->msg_ctx, MSG_INFO,
+			HS20_T_C_FILTERING_REMOVE MACSTR, MAC2STR(sta->addr));
+	}
+}

src/ap/hs20.h

@@ -20,5 +20,7 @@ int hs20_send_wnm_notification_deauth_req(struct hostapd_data *hapd,
 					  const struct wpabuf *payload);
 int hs20_send_wnm_notification_t_c(struct hostapd_data *hapd,
 				   const u8 *addr);
+void hs20_t_c_filtering(struct hostapd_data *hapd, struct sta_info *sta,
+			int enabled);
 
 #endif /* HS20_H */

src/ap/ieee802_1x.c

@@ -1632,14 +1632,7 @@ static void ieee802_1x_hs20_t_c_filtering(struct hostapd_data *hapd,
 	wpa_printf(MSG_DEBUG,
 		   "HS 2.0: Terms and Conditions filtering %02x %02x %02x %02x",
 		   pos[0], pos[1], pos[2], pos[3]);
-	if (pos[0] & BIT(0)) {
-		wpa_printf(MSG_DEBUG,
-			   "HS 2.0: Terms and Conditions filtering required");
-		sta->hs20_t_c_filtering = 1;
-		/* TODO: Enable firewall filtering for the STA */
-	} else {
-		sta->hs20_t_c_filtering = 0;
-	}
+	hs20_t_c_filtering(hapd, sta, pos[0] & BIT(0));
 }
 
 #endif /* CONFIG_HS20 */

src/common/wpa_ctrl.h

@@ -298,6 +298,9 @@ extern "C" {
 #define AP_REJECTED_MAX_STA "AP-REJECTED-MAX-STA "
 #define AP_REJECTED_BLOCKED_STA "AP-REJECTED-BLOCKED-STA "
 
+#define HS20_T_C_FILTERING_ADD "HS20-T-C-FILTERING-ADD "
+#define HS20_T_C_FILTERING_REMOVE "HS20-T-C-FILTERING-REMOVE "
+
 #define AP_EVENT_ENABLED "AP-ENABLED "
 #define AP_EVENT_DISABLED "AP-DISABLED "
 

src/radius/radius_das.c

@@ -27,6 +27,7 @@ struct radius_das_data {
 	void *ctx;
 	enum radius_das_res (*disconnect)(void *ctx,
 					  struct radius_das_attrs *attr);
+	enum radius_das_res (*coa)(void *ctx, struct radius_das_attrs *attr);
 };
 
 
@@ -161,6 +162,10 @@ static struct radius_msg * radius_das_disconnect(struct radius_das_data *das,
 			   abuf, from_port);
 		error = 508;
 		break;
+	case RADIUS_DAS_COA_FAILED:
+		/* not used with Disconnect-Request */
+		error = 405;
+		break;
 	case RADIUS_DAS_SUCCESS:
 		error = 0;
 		break;
@@ -184,6 +189,195 @@ fail:
 }
 
 
+static struct radius_msg * radius_das_coa(struct radius_das_data *das,
+					  struct radius_msg *msg,
+					  const char *abuf, int from_port)
+{
+	struct radius_hdr *hdr;
+	struct radius_msg *reply;
+	u8 allowed[] = {
+		RADIUS_ATTR_USER_NAME,
+		RADIUS_ATTR_NAS_IP_ADDRESS,
+		RADIUS_ATTR_CALLING_STATION_ID,
+		RADIUS_ATTR_NAS_IDENTIFIER,
+		RADIUS_ATTR_ACCT_SESSION_ID,
+		RADIUS_ATTR_ACCT_MULTI_SESSION_ID,
+		RADIUS_ATTR_EVENT_TIMESTAMP,
+		RADIUS_ATTR_MESSAGE_AUTHENTICATOR,
+		RADIUS_ATTR_CHARGEABLE_USER_IDENTITY,
+#ifdef CONFIG_HS20
+		RADIUS_ATTR_VENDOR_SPECIFIC,
+#endif /* CONFIG_HS20 */
+#ifdef CONFIG_IPV6
+		RADIUS_ATTR_NAS_IPV6_ADDRESS,
+#endif /* CONFIG_IPV6 */
+		0
+	};
+	int error = 405;
+	u8 attr;
+	enum radius_das_res res;
+	struct radius_das_attrs attrs;
+	u8 *buf;
+	size_t len;
+	char tmp[100];
+	u8 sta_addr[ETH_ALEN];
+
+	hdr = radius_msg_get_hdr(msg);
+
+	if (!das->coa) {
+		wpa_printf(MSG_INFO, "DAS: CoA not supported");
+		goto fail;
+	}
+
+	attr = radius_msg_find_unlisted_attr(msg, allowed);
+	if (attr) {
+		wpa_printf(MSG_INFO,
+			   "DAS: Unsupported attribute %u in CoA-Request from %s:%d",
+			   attr, abuf, from_port);
+		error = 401;
+		goto fail;
+	}
+
+	os_memset(&attrs, 0, sizeof(attrs));
+
+	if (radius_msg_get_attr_ptr(msg, RADIUS_ATTR_NAS_IP_ADDRESS,
+				    &buf, &len, NULL) == 0) {
+		if (len != 4) {
+			wpa_printf(MSG_INFO, "DAS: Invalid NAS-IP-Address from %s:%d",
+				   abuf, from_port);
+			error = 407;
+			goto fail;
+		}
+		attrs.nas_ip_addr = buf;
+	}
+
+#ifdef CONFIG_IPV6
+	if (radius_msg_get_attr_ptr(msg, RADIUS_ATTR_NAS_IPV6_ADDRESS,
+				    &buf, &len, NULL) == 0) {
+		if (len != 16) {
+			wpa_printf(MSG_INFO, "DAS: Invalid NAS-IPv6-Address from %s:%d",
+				   abuf, from_port);
+			error = 407;
+			goto fail;
+		}
+		attrs.nas_ipv6_addr = buf;
+	}
+#endif /* CONFIG_IPV6 */
+
+	if (radius_msg_get_attr_ptr(msg, RADIUS_ATTR_NAS_IDENTIFIER,
+				    &buf, &len, NULL) == 0) {
+		attrs.nas_identifier = buf;
+		attrs.nas_identifier_len = len;
+	}
+
+	if (radius_msg_get_attr_ptr(msg, RADIUS_ATTR_CALLING_STATION_ID,
+				    &buf, &len, NULL) == 0) {
+		if (len >= sizeof(tmp))
+			len = sizeof(tmp) - 1;
+		os_memcpy(tmp, buf, len);
+		tmp[len] = '\0';
+		if (hwaddr_aton2(tmp, sta_addr) < 0) {
+			wpa_printf(MSG_INFO, "DAS: Invalid Calling-Station-Id "
+				   "'%s' from %s:%d", tmp, abuf, from_port);
+			error = 407;
+			goto fail;
+		}
+		attrs.sta_addr = sta_addr;
+	}
+
+	if (radius_msg_get_attr_ptr(msg, RADIUS_ATTR_USER_NAME,
+				    &buf, &len, NULL) == 0) {
+		attrs.user_name = buf;
+		attrs.user_name_len = len;
+	}
+
+	if (radius_msg_get_attr_ptr(msg, RADIUS_ATTR_ACCT_SESSION_ID,
+				    &buf, &len, NULL) == 0) {
+		attrs.acct_session_id = buf;
+		attrs.acct_session_id_len = len;
+	}
+
+	if (radius_msg_get_attr_ptr(msg, RADIUS_ATTR_ACCT_MULTI_SESSION_ID,
+				    &buf, &len, NULL) == 0) {
+		attrs.acct_multi_session_id = buf;
+		attrs.acct_multi_session_id_len = len;
+	}
+
+	if (radius_msg_get_attr_ptr(msg, RADIUS_ATTR_CHARGEABLE_USER_IDENTITY,
+				    &buf, &len, NULL) == 0) {
+		attrs.cui = buf;
+		attrs.cui_len = len;
+	}
+
+#ifdef CONFIG_HS20
+	if (radius_msg_get_attr_ptr(msg, RADIUS_ATTR_VENDOR_SPECIFIC,
+				    &buf, &len, NULL) == 0) {
+		if (len < 10 || WPA_GET_BE32(buf) != RADIUS_VENDOR_ID_WFA ||
+		    buf[4] != RADIUS_VENDOR_ATTR_WFA_HS20_T_C_FILTERING ||
+		    buf[5] < 6) {
+			wpa_printf(MSG_INFO,
+				   "DAS: Unsupported attribute %u in CoA-Request from %s:%d",
+				   attr, abuf, from_port);
+			error = 401;
+			goto fail;
+		}
+		attrs.hs20_t_c_filtering = &buf[6];
+	}
+
+	if (!attrs.hs20_t_c_filtering) {
+			wpa_printf(MSG_INFO,
+				   "DAS: No supported authorization change attribute in CoA-Request from %s:%d",
+				   abuf, from_port);
+			error = 402;
+			goto fail;
+	}
+#endif /* CONFIG_HS20 */
+
+	res = das->coa(das->ctx, &attrs);
+	switch (res) {
+	case RADIUS_DAS_NAS_MISMATCH:
+		wpa_printf(MSG_INFO, "DAS: NAS mismatch from %s:%d",
+			   abuf, from_port);
+		error = 403;
+		break;
+	case RADIUS_DAS_SESSION_NOT_FOUND:
+		wpa_printf(MSG_INFO,
+			   "DAS: Session not found for request from %s:%d",
+			   abuf, from_port);
+		error = 503;
+		break;
+	case RADIUS_DAS_MULTI_SESSION_MATCH:
+		wpa_printf(MSG_INFO,
+			   "DAS: Multiple sessions match for request from %s:%d",
+			   abuf, from_port);
+		error = 508;
+		break;
+	case RADIUS_DAS_COA_FAILED:
+		wpa_printf(MSG_INFO, "DAS: CoA failed for request from %s:%d",
+			   abuf, from_port);
+		error = 407;
+		break;
+	case RADIUS_DAS_SUCCESS:
+		error = 0;
+		break;
+	}
+
+fail:
+	reply = radius_msg_new(error ? RADIUS_CODE_COA_NAK :
+			       RADIUS_CODE_COA_ACK, hdr->identifier);
+	if (!reply)
+		return NULL;
+
+	if (error &&
+	    !radius_msg_add_attr_int32(reply, RADIUS_ATTR_ERROR_CAUSE, error)) {
+		radius_msg_free(reply);
+		return NULL;
+	}
+
+	return reply;
+}
+
+
 static void radius_das_receive(int sock, void *eloop_ctx, void *sock_ctx)
 {
 	struct radius_das_data *das = eloop_ctx;
@@ -270,19 +464,7 @@ static void radius_das_receive(int sock, void *eloop_ctx, void *sock_ctx)
 		reply = radius_das_disconnect(das, msg, abuf, from_port);
 		break;
 	case RADIUS_CODE_COA_REQUEST:
-		/* TODO */
-		reply = radius_msg_new(RADIUS_CODE_COA_NAK,
-				       hdr->identifier);
-		if (reply == NULL)
-			break;
-
-		/* Unsupported Service */
-		if (!radius_msg_add_attr_int32(reply, RADIUS_ATTR_ERROR_CAUSE,
-					       405)) {
-			radius_msg_free(reply);
-			reply = NULL;
-			break;
-		}
+		reply = radius_das_coa(das, msg, abuf, from_port);
 		break;
 	default:
 		wpa_printf(MSG_DEBUG, "DAS: Unexpected RADIUS code %u in "
@@ -369,6 +551,7 @@ radius_das_init(struct radius_das_conf *conf)
 		conf->require_message_authenticator;
 	das->ctx = conf->ctx;
 	das->disconnect = conf->disconnect;
+	das->coa = conf->coa;
 
 	os_memcpy(&das->client_addr, conf->client_addr,
 		  sizeof(das->client_addr));

src/radius/radius_das.h

@@ -16,6 +16,7 @@ enum radius_das_res {
 	RADIUS_DAS_NAS_MISMATCH,
 	RADIUS_DAS_SESSION_NOT_FOUND,
 	RADIUS_DAS_MULTI_SESSION_MATCH,
+	RADIUS_DAS_COA_FAILED,
 };
 
 struct radius_das_attrs {
@@ -35,6 +36,9 @@ struct radius_das_attrs {
 	size_t acct_multi_session_id_len;
 	const u8 *cui;
 	size_t cui_len;
+
+	/* Authorization changes */
+	const u8 *hs20_t_c_filtering;
 };
 
 struct radius_das_conf {
@@ -48,6 +52,7 @@ struct radius_das_conf {
 	void *ctx;
 	enum radius_das_res (*disconnect)(void *ctx,
 					  struct radius_das_attrs *attr);
+	enum radius_das_res (*coa)(void *ctx, struct radius_das_attrs *attr);
 };
 
 struct radius_das_data *