Move GAS/ANQP build routines to a separate file from P2P

GAS/ANQP is a generic protocol and in no way specific to P2P, so move
routines used to build GAS/ANQP frames to a separate file that can be
shared for other uses than just P2P service discovery.

src/common/gas.c

@@ -0,0 +1,279 @@
+/*
+ * Generic advertisement service (GAS) (IEEE 802.11u)
+ * Copyright (c) 2009, Atheros Communications
+ * Copyright (c) 2011, Qualcomm Atheros
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Alternatively, this software may be distributed under the terms of BSD
+ * license.
+ *
+ * See README and COPYING for more details.
+ */
+
+#include "includes.h"
+
+#include "common.h"
+#include "ieee802_11_defs.h"
+#include "gas.h"
+
+
+static struct wpabuf *
+gas_build_req(u8 action, u8 dialog_token, size_t size)
+{
+	struct wpabuf *buf;
+
+	buf = wpabuf_alloc(100 + size);
+	if (buf == NULL)
+		return NULL;
+
+	wpabuf_put_u8(buf, WLAN_ACTION_PUBLIC);
+	wpabuf_put_u8(buf, action);
+	wpabuf_put_u8(buf, dialog_token);
+
+	return buf;
+}
+
+
+static struct wpabuf * gas_build_initial_req(u8 dialog_token, size_t size)
+{
+	return gas_build_req(WLAN_PA_GAS_INITIAL_REQ, dialog_token,
+			     size);
+}
+
+
+struct wpabuf * gas_build_comeback_req(u8 dialog_token)
+{
+	return gas_build_req(WLAN_PA_GAS_COMEBACK_REQ, dialog_token, 0);
+}
+
+
+static struct wpabuf *
+gas_build_resp(u8 action, u8 dialog_token, u16 status_code, u8 frag_id,
+	       u8 more, u16 comeback_delay, size_t size)
+{
+	struct wpabuf *buf;
+
+	buf = wpabuf_alloc(100 + size);
+	if (buf == NULL)
+		return NULL;
+
+	wpabuf_put_u8(buf, WLAN_ACTION_PUBLIC);
+	wpabuf_put_u8(buf, action);
+	wpabuf_put_u8(buf, dialog_token);
+	wpabuf_put_le16(buf, status_code);
+	if (action == WLAN_PA_GAS_COMEBACK_RESP)
+		wpabuf_put_u8(buf, frag_id | (more ? 0x80 : 0));
+	wpabuf_put_le16(buf, comeback_delay);
+
+	return buf;
+}
+
+
+static struct wpabuf *
+gas_build_initial_resp(u8 dialog_token, u16 status_code, u16 comeback_delay,
+		       size_t size)
+{
+	return gas_build_resp(WLAN_PA_GAS_INITIAL_RESP, dialog_token,
+			      status_code, 0, 0, comeback_delay, size);
+}
+
+
+static struct wpabuf *
+gas_build_comeback_resp(u8 dialog_token, u16 status_code, u8 frag_id, u8 more,
+			u16 comeback_delay, size_t size)
+{
+	return gas_build_resp(WLAN_PA_GAS_COMEBACK_RESP, dialog_token,
+			      status_code, frag_id, more, comeback_delay,
+			      size);
+}
+
+
+/**
+ * gas_add_adv_proto_anqp - Add an Advertisement Protocol element
+ * @buf: Buffer to which the element is added
+ * @query_resp_len_limit: Query Response Length Limit in units of 256 octets
+ * @pame_bi: Pre-Association Message Exchange BSSID Independent (0/1)
+ *
+ *
+ * @query_resp_len_limit is 0 for request and 1-0x7f for response. 0x7f means
+ * that the maximum limit is determined by the maximum allowable number of
+ * fragments in the GAS Query Response Fragment ID.
+ */
+static void gas_add_adv_proto_anqp(struct wpabuf *buf, u8 query_resp_len_limit,
+				   u8 pame_bi)
+{
+	/* Advertisement Protocol IE */
+	wpabuf_put_u8(buf, WLAN_EID_ADV_PROTO);
+	wpabuf_put_u8(buf, 2); /* Length */
+	wpabuf_put_u8(buf, (query_resp_len_limit & 0x7f) |
+		      (pame_bi ? 0x80 : 0));
+	/* Advertisement Protocol */
+	wpabuf_put_u8(buf, ACCESS_NETWORK_QUERY_PROTOCOL);
+}
+
+
+struct wpabuf * gas_anqp_build_initial_req(u8 dialog_token, size_t size)
+{
+	struct wpabuf *buf;
+
+	buf = gas_build_initial_req(dialog_token, 4 + size);
+	if (buf == NULL)
+		return NULL;
+
+	gas_add_adv_proto_anqp(buf, 0, 0);
+
+	wpabuf_put(buf, 2); /* Query Request Length to be filled */
+
+	return buf;
+}
+
+
+struct wpabuf * gas_anqp_build_initial_resp(u8 dialog_token, u16 status_code,
+					    u16 comeback_delay, size_t size)
+{
+	struct wpabuf *buf;
+
+	buf = gas_build_initial_resp(dialog_token, status_code, comeback_delay,
+				     4 + size);
+	if (buf == NULL)
+		return NULL;
+
+	gas_add_adv_proto_anqp(buf, 0x7f, 0);
+
+	wpabuf_put(buf, 2); /* Query Response Length to be filled */
+
+	return buf;
+}
+
+
+struct wpabuf * gas_anqp_build_initial_resp_buf(u8 dialog_token,
+						u16 status_code,
+						u16 comeback_delay,
+						struct wpabuf *payload)
+{
+	struct wpabuf *buf;
+
+	buf = gas_anqp_build_initial_resp(dialog_token, status_code,
+					  comeback_delay,
+					  payload ? wpabuf_len(payload) : 0);
+	if (buf == NULL)
+		return NULL;
+
+	if (payload)
+		wpabuf_put_buf(buf, payload);
+
+	gas_anqp_set_len(buf);
+
+	return buf;
+}
+
+
+struct wpabuf * gas_anqp_build_comeback_resp(u8 dialog_token, u16 status_code,
+					     u8 frag_id, u8 more,
+					     u16 comeback_delay, size_t size)
+{
+	struct wpabuf *buf;
+
+	buf = gas_build_comeback_resp(dialog_token, status_code,
+				      frag_id, more, comeback_delay, 4 + size);
+	if (buf == NULL)
+		return NULL;
+
+	gas_add_adv_proto_anqp(buf, 0x7f, 0);
+
+	wpabuf_put(buf, 2); /* Query Response Length to be filled */
+
+	return buf;
+}
+
+
+struct wpabuf * gas_anqp_build_comeback_resp_buf(u8 dialog_token,
+						 u16 status_code,
+						 u8 frag_id, u8 more,
+						 u16 comeback_delay,
+						 struct wpabuf *payload)
+{
+	struct wpabuf *buf;
+
+	buf = gas_anqp_build_comeback_resp(dialog_token, status_code, frag_id,
+					   more, comeback_delay,
+					   payload ? wpabuf_len(payload) : 0);
+	if (buf == NULL)
+		return NULL;
+
+	if (payload)
+		wpabuf_put_buf(buf, payload);
+
+	gas_anqp_set_len(buf);
+
+	return buf;
+}
+
+
+/**
+ * gas_anqp_set_len - Set Query Request/Response Length
+ * @buf: GAS message
+ *
+ * This function is used to update the Query Request/Response Length field once
+ * the payload has been filled.
+ */
+void gas_anqp_set_len(struct wpabuf *buf)
+{
+	u8 action;
+	size_t offset;
+	u8 *len;
+
+	if (buf == NULL || wpabuf_len(buf) < 2)
+		return;
+
+	action = *(wpabuf_head_u8(buf) + 1);
+	switch (action) {
+	case WLAN_PA_GAS_INITIAL_REQ:
+		offset = 3 + 4;
+		break;
+	case WLAN_PA_GAS_INITIAL_RESP:
+		offset = 7 + 4;
+		break;
+	case WLAN_PA_GAS_COMEBACK_RESP:
+		offset = 8 + 4;
+		break;
+	default:
+		return;
+	}
+
+	if (wpabuf_len(buf) < offset + 2)
+		return;
+
+	len = wpabuf_mhead_u8(buf) + offset;
+	WPA_PUT_LE16(len, (u8 *) wpabuf_put(buf, 0) - len - 2);
+}
+
+
+/**
+ * gas_anqp_add_element - Add ANQP element header
+ * @buf: GAS message
+ * @info_id: ANQP Info ID
+ * Returns: Pointer to the Length field for gas_anqp_set_element_len()
+ */
+u8 * gas_anqp_add_element(struct wpabuf *buf, u16 info_id)
+{
+	wpabuf_put_le16(buf, info_id);
+	return wpabuf_put(buf, 2); /* Length to be filled */
+}
+
+
+/**
+ * gas_anqp_set_element_len - Update ANQP element Length field
+ * @buf: GAS message
+ * @len_pos: Length field position from gas_anqp_add_element()
+ *
+ * This function is called after the ANQP element payload has been added to the
+ * buffer.
+ */
+void gas_anqp_set_element_len(struct wpabuf *buf, u8 *len_pos)
+{
+	WPA_PUT_LE16(len_pos, (u8 *) wpabuf_put(buf, 0) - len_pos - 2);
+}

src/common/gas.h

@@ -0,0 +1,40 @@
+/*
+ * Generic advertisement service (GAS) (IEEE 802.11u)
+ * Copyright (c) 2009, Atheros Communications
+ * Copyright (c) 2011, Qualcomm Atheros
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Alternatively, this software may be distributed under the terms of BSD
+ * license.
+ *
+ * See README and COPYING for more details.
+ */
+
+#ifndef GAS_H
+#define GAS_H
+
+struct wpabuf * gas_build_comeback_req(u8 dialog_token);
+struct wpabuf * gas_anqp_build_initial_req(u8 dialog_token, size_t size);
+struct wpabuf * gas_anqp_build_initial_resp(u8 dialog_token, u16 status_code,
+					    u16 comeback_delay, size_t size);
+struct wpabuf * gas_anqp_build_initial_resp_buf(u8 dialog_token,
+						u16 status_code,
+						u16 comeback_delay,
+						struct wpabuf *payload);
+struct wpabuf * gas_anqp_build_comeback_resp(u8 dialog_token, u16 status_code,
+					     u8 frag_id, u8 more,
+					     u16 comeback_delay, size_t size);
+struct wpabuf * gas_anqp_build_comeback_resp_buf(u8 dialog_token,
+						 u16 status_code,
+						 u8 frag_id, u8 more,
+						 u16 comeback_delay,
+						 struct wpabuf *payload);
+void gas_anqp_set_len(struct wpabuf *buf);
+
+u8 * gas_anqp_add_element(struct wpabuf *buf, u16 info_id);
+void gas_anqp_set_element_len(struct wpabuf *buf, u8 *len_pos);
+
+#endif /* GAS_H */

src/p2p/p2p_sd.c

@@ -16,6 +16,7 @@
 
 #include "common.h"
 #include "common/ieee802_11_defs.h"
+#include "common/gas.h"
 #include "p2p_i.h"
 #include "p2p.h"
 
@@ -90,52 +91,21 @@ static struct wpabuf * p2p_build_sd_query(u16 update_indic,
 					  struct wpabuf *tlvs)
 {
 	struct wpabuf *buf;
-	u8 *len_pos, *len_pos2;
+	u8 *len_pos;
 
-	buf = wpabuf_alloc(1000 + wpabuf_len(tlvs));
+	buf = gas_anqp_build_initial_req(0, 100 + wpabuf_len(tlvs));
 	if (buf == NULL)
 		return NULL;
 
-	wpabuf_put_u8(buf, WLAN_ACTION_PUBLIC);
-	wpabuf_put_u8(buf, WLAN_PA_GAS_INITIAL_REQ);
-	wpabuf_put_u8(buf, 0); /* Dialog Token */
-
-	/* Advertisement Protocol IE */
-	wpabuf_put_u8(buf, WLAN_EID_ADV_PROTO);
-	wpabuf_put_u8(buf, 2); /* Length */
-	wpabuf_put_u8(buf, 0); /* QueryRespLenLimit | PAME-BI */
-	/* Advertisement Protocol */
-	wpabuf_put_u8(buf, ACCESS_NETWORK_QUERY_PROTOCOL);
-
-	/* Query Request */
-	len_pos = wpabuf_put(buf, 2); /* Length (to be filled) */
-
 	/* ANQP Query Request Frame */
-	wpabuf_put_le16(buf, ANQP_VENDOR_SPECIFIC); /* Info ID */
+	len_pos = gas_anqp_add_element(buf, ANQP_VENDOR_SPECIFIC);
-	len_pos2 = wpabuf_put(buf, 2); /* Length (to be filled) */
 	wpabuf_put_be24(buf, OUI_WFA);
 	wpabuf_put_u8(buf, P2P_OUI_TYPE);
 	wpabuf_put_le16(buf, update_indic); /* Service Update Indicator */
 	wpabuf_put_buf(buf, tlvs);
+	gas_anqp_set_element_len(buf, len_pos);
 
-	WPA_PUT_LE16(len_pos2, (u8 *) wpabuf_put(buf, 0) - len_pos2 - 2);
+	gas_anqp_set_len(buf);
-	WPA_PUT_LE16(len_pos, (u8 *) wpabuf_put(buf, 0) - len_pos - 2);
-
-	return buf;
-}
-
-
-static struct wpabuf * p2p_build_gas_comeback_req(u8 dialog_token)
-{
-	struct wpabuf *buf;
-
-	buf = wpabuf_alloc(3);
-	if (buf == NULL)
-		return NULL;
-
-	wpabuf_put_u8(buf, WLAN_ACTION_PUBLIC);
-	wpabuf_put_u8(buf, WLAN_PA_GAS_COMEBACK_REQ);
-	wpabuf_put_u8(buf, dialog_token);
 
 	return buf;
 }
@@ -146,7 +116,7 @@ static void p2p_send_gas_comeback_req(struct p2p_data *p2p, const u8 *dst,
 {
 	struct wpabuf *req;
 
-	req = p2p_build_gas_comeback_req(dialog_token);
+	req = gas_build_comeback_req(dialog_token);
 	if (req == NULL)
 		return;
 
@@ -166,43 +136,26 @@ static struct wpabuf * p2p_build_sd_response(u8 dialog_token, u16 status_code,
 					     const struct wpabuf *tlvs)
 {
 	struct wpabuf *buf;
-	u8 *len_pos, *len_pos2;
+	u8 *len_pos;
 
-	buf = wpabuf_alloc(1000 + (tlvs ? wpabuf_len(tlvs) : 0));
+	buf = gas_anqp_build_initial_resp(dialog_token, status_code,
+					  comeback_delay,
+					  100 + (tlvs ? wpabuf_len(tlvs) : 0));
 	if (buf == NULL)
 		return NULL;
 
-	wpabuf_put_u8(buf, WLAN_ACTION_PUBLIC);
-	wpabuf_put_u8(buf, WLAN_PA_GAS_INITIAL_RESP);
-	wpabuf_put_u8(buf, dialog_token);
-	wpabuf_put_le16(buf, status_code);
-	wpabuf_put_le16(buf, comeback_delay);
-
-	/* Advertisement Protocol IE */
-	wpabuf_put_u8(buf, WLAN_EID_ADV_PROTO);
-	wpabuf_put_u8(buf, 2); /* Length */
-	wpabuf_put_u8(buf, 0x7f); /* QueryRespLenLimit | PAME-BI */
-	/* Advertisement Protocol */
-	wpabuf_put_u8(buf, ACCESS_NETWORK_QUERY_PROTOCOL);
-
-	/* Query Response */
-	len_pos = wpabuf_put(buf, 2); /* Length (to be filled) */
-
 	if (tlvs) {
 		/* ANQP Query Response Frame */
-		wpabuf_put_le16(buf, ANQP_VENDOR_SPECIFIC); /* Info ID */
+		len_pos = gas_anqp_add_element(buf, ANQP_VENDOR_SPECIFIC);
-		len_pos2 = wpabuf_put(buf, 2); /* Length (to be filled) */
 		wpabuf_put_be24(buf, OUI_WFA);
 		wpabuf_put_u8(buf, P2P_OUI_TYPE);
 		 /* Service Update Indicator */
 		wpabuf_put_le16(buf, update_indic);
 		wpabuf_put_buf(buf, tlvs);
-
+		gas_anqp_set_element_len(buf, len_pos);
-		WPA_PUT_LE16(len_pos2,
-			     (u8 *) wpabuf_put(buf, 0) - len_pos2 - 2);
 	}
 
-	WPA_PUT_LE16(len_pos, (u8 *) wpabuf_put(buf, 0) - len_pos - 2);
+	gas_anqp_set_len(buf);
 
 	return buf;
 }
@@ -216,29 +169,12 @@ static struct wpabuf * p2p_build_gas_comeback_resp(u8 dialog_token,
 						   u16 total_len)
 {
 	struct wpabuf *buf;
-	u8 *len_pos;
 
-	buf = wpabuf_alloc(1000 + len);
+	buf = gas_anqp_build_comeback_resp(dialog_token, status_code, frag_id,
+					   more, 0, 100 + len);
 	if (buf == NULL)
 		return NULL;
 
-	wpabuf_put_u8(buf, WLAN_ACTION_PUBLIC);
-	wpabuf_put_u8(buf, WLAN_PA_GAS_COMEBACK_RESP);
-	wpabuf_put_u8(buf, dialog_token);
-	wpabuf_put_le16(buf, status_code);
-	wpabuf_put_u8(buf, frag_id | (more ? 0x80 : 0));
-	wpabuf_put_le16(buf, 0); /* Comeback Delay */
-
-	/* Advertisement Protocol IE */
-	wpabuf_put_u8(buf, WLAN_EID_ADV_PROTO);
-	wpabuf_put_u8(buf, 2); /* Length */
-	wpabuf_put_u8(buf, 0x7f); /* QueryRespLenLimit | PAME-BI */
-	/* Advertisement Protocol */
-	wpabuf_put_u8(buf, ACCESS_NETWORK_QUERY_PROTOCOL);
-
-	/* Query Response */
-	len_pos = wpabuf_put(buf, 2); /* Length (to be filled) */
-
 	if (frag_id == 0) {
 		/* ANQP Query Response Frame */
 		wpabuf_put_le16(buf, ANQP_VENDOR_SPECIFIC); /* Info ID */
@@ -250,8 +186,7 @@ static struct wpabuf * p2p_build_gas_comeback_resp(u8 dialog_token,
 	}
 
 	wpabuf_put_data(buf, data, len);
-
+	gas_anqp_set_len(buf);
-	WPA_PUT_LE16(len_pos, (u8 *) wpabuf_put(buf, 0) - len_pos - 2);
 
 	return buf;
 }

wpa_supplicant/Makefile

@@ -201,6 +201,7 @@ OBJS += ../src/p2p/p2p_dev_disc.o
 OBJS += ../src/p2p/p2p_group.o
 OBJS += ../src/ap/p2p_hostapd.o
 CFLAGS += -DCONFIG_P2P
+NEED_GAS=y
 NEED_80211_COMMON=y
 ifdef CONFIG_P2P_STRICT
 CFLAGS += -DCONFIG_P2P_STRICT
@@ -1282,6 +1283,10 @@ CFLAGS += -DCONFIG_BGSCAN
 OBJS += bgscan.o
 endif
 
+ifdef NEED_GAS
+OBJS += ../src/common/gas.o
+endif
+
 OBJS_wpa_rm := ctrl_iface.o mlme.o ctrl_iface_unix.o
 OBJS_wpa := $(filter-out $(OBJS_wpa_rm),$(OBJS)) $(OBJS_h) tests/test_wpa.o
 ifdef CONFIG_AUTHENTICATOR