diff mbox series

[V2,5/7] multiple_bssid: add the new IE

Message ID 20200706125031.668258-6-john@phrozen.org
State Superseded
Headers show
Series multiple_bssid: add support | expand

Commit Message

John Crispin July 6, 2020, 12:50 p.m. UTC
For multiple bssid to work we need to add a new IE to the beacon and probe
responses that includes the information on the non-transmitting BSSs. If
all the information does not fit into the 255 bytes, we need to split it
up over multiple IEs of the same type.

Signed-off-by: John Crispin <john@phrozen.org>
---
 src/ap/beacon.c              |  10 +++-
 src/ap/ieee802_11.c          | 101 +++++++++++++++++++++++++++++++++++
 src/ap/ieee802_11.h          |   3 ++
 src/ap/ieee802_11_shared.c   |   2 +
 src/common/ieee802_11_defs.h |   2 +
 5 files changed, 117 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/src/ap/beacon.c b/src/ap/beacon.c
index 4988ee2a1..2ba374c68 100644
--- a/src/ap/beacon.c
+++ b/src/ap/beacon.c
@@ -293,7 +293,7 @@  static const u8 * hostapd_vendor_wpa_ie(struct hostapd_data *hapd,
 }
 
 
-static u8 * hostapd_get_rsne(struct hostapd_data *hapd, u8 *pos, size_t len)
+u8 * hostapd_get_rsne(struct hostapd_data *hapd, u8 *pos, size_t len)
 {
 	const u8 *ie;
 
@@ -472,6 +472,7 @@  static u8 * hostapd_gen_probe_resp(struct hostapd_data *hapd,
 	buflen += hostapd_mbo_ie_len(hapd);
 	buflen += hostapd_eid_owe_trans_len(hapd);
 	buflen += hostapd_eid_dpp_cc_len(hapd);
+	buflen += hostapd_eid_multiple_bssid_len(hapd);
 
 	resp = os_zalloc(buflen);
 	if (resp == NULL)
@@ -527,6 +528,9 @@  static u8 * hostapd_gen_probe_resp(struct hostapd_data *hapd,
 	pos = hostapd_eid_rm_enabled_capab(hapd, pos, epos - pos);
 	pos = hostapd_get_mde(hapd, pos, epos - pos);
 
+        if (hapd->iconf->multiple_bssid)
+		pos = hostapd_eid_multiple_bssid(hapd, pos, epos);
+
 	/* eCSA IE */
 	csa_pos = hostapd_eid_ecsa(hapd, pos);
 	if (csa_pos != pos)
@@ -1177,6 +1181,7 @@  int ieee802_11_build_ap_params(struct hostapd_data *hapd,
 	tail_len += hostapd_mbo_ie_len(hapd);
 	tail_len += hostapd_eid_owe_trans_len(hapd);
 	tail_len += hostapd_eid_dpp_cc_len(hapd);
+	tail_len += hostapd_eid_multiple_bssid_len(hapd);
 
 	tailpos = tail = os_malloc(tail_len);
 	if (head == NULL || tail == NULL) {
@@ -1249,6 +1254,9 @@  int ieee802_11_build_ap_params(struct hostapd_data *hapd,
 					       tailend - tailpos);
 	tailpos = hostapd_get_mde(hapd, tailpos, tailend - tailpos);
 
+	if (hapd->iconf->multiple_bssid)
+		tailpos = hostapd_eid_multiple_bssid(hapd, tailpos, tailend);
+
 	/* eCSA IE */
 	csa_pos = hostapd_eid_ecsa(hapd, tailpos);
 	if (csa_pos != tailpos)
diff --git a/src/ap/ieee802_11.c b/src/ap/ieee802_11.c
index b91640070..de4a7dfa3 100644
--- a/src/ap/ieee802_11.c
+++ b/src/ap/ieee802_11.c
@@ -6,6 +6,7 @@ 
  * See README for more details.
  */
 
+#include <math.h>
 #include "utils/includes.h"
 
 #ifndef CONFIG_NATIVE_WINDOWS
@@ -5617,4 +5618,104 @@  u8 * hostapd_eid_wb_chsw_wrapper(struct hostapd_data *hapd, u8 *eid)
 	return eid;
 }
 
+
+static int hostapd_eid_multiple_bssid_chunk_len(struct hostapd_data *hapd,
+						int *count)
+{
+	/* ID + size + count */
+	int i, len = 3;
+
+	for (i = *count; i < hapd->iface->num_bss; i++) {
+		struct hostapd_data *bss = hapd->iface->bss[i];
+		/* 11 mbssid + ssid len + 32 RSN */
+		int ssid_len = 11 + bss->conf->ssid.ssid_len + 32;
+
+		if (len + ssid_len > 255) {
+			goto multiple_bssid_too_big;
+		}
+		len += ssid_len;
+	}
+
+multiple_bssid_too_big:
+	*count = i;
+
+	return len;
+}
+
+
+int hostapd_eid_multiple_bssid_len(struct hostapd_data *hapd)
+{
+	int count = 1, len = 0;
+
+	while (count < hapd->iface->num_bss)
+		len += hostapd_eid_multiple_bssid_chunk_len(hapd, &count);
+
+	return len;
+}
+
+
+static u8 * hostapd_eid_multiple_bssid_chunk(struct hostapd_data *hapd,
+					     u8 *eid, u8 *end, int *count)
+{
+	u8 *size_offset, *num_offset, num = 0;
+	int i;
+
+	*eid++ = WLAN_EID_MULTIPLE_BSSID;
+	size_offset = eid++;
+	num_offset = eid++;
+
+	for (i = *count; i < hapd->iface->num_bss; i++) {
+		struct hostapd_data *bss = hapd->iface->bss[i];
+		u8 *bss_size_offset, *pos = eid;
+		u16 capab_info;
+
+		*eid++ = WLAN_EID_SUBELEMENT_NONTRANSMITTED_BSSID_PROFILE;
+		bss_size_offset = eid++;
+
+		*eid++ = WLAN_EID_NONTRANSMITTED_BSSID_CAPA;
+		*eid++ = sizeof(capab_info);
+		capab_info = host_to_le16(hostapd_own_capab_info(bss));
+		os_memcpy(eid, (const void*)&capab_info, sizeof(capab_info));
+		eid += sizeof(capab_info);
+
+		*eid++ = WLAN_EID_SSID;
+		*eid++ = bss->conf->ssid.ssid_len;
+		os_memcpy(eid, bss->conf->ssid.ssid, bss->conf->ssid.ssid_len);
+		eid += bss->conf->ssid.ssid_len;
+
+		*eid++ = WLAN_EID_MULTIPLE_BSSID_INDEX;
+		*eid++ = 1;
+		*eid++ = i;
+
+		eid = hostapd_get_rsne(bss, eid, end - eid);
+		*bss_size_offset = (eid - bss_size_offset) - 1;
+
+		if ((eid - size_offset) - 1 > 255) {
+			eid = pos;
+			goto multiple_bssid_too_big;
+		}
+		num++;
+	}
+
+multiple_bssid_too_big:
+	*count = i;
+	*num_offset = (u8)ceil(log2(num));
+	if (*num_offset < 2)
+		*num_offset = 2;
+	*size_offset = (eid - size_offset) - 1;
+
+	return eid;
+}
+
+
+u8 * hostapd_eid_multiple_bssid(struct hostapd_data *hapd, u8 *eid, u8 *end)
+{
+	int count = 1;
+
+	while (count < hapd->iface->num_bss)
+		eid = hostapd_eid_multiple_bssid_chunk(hapd, eid, end, &count);
+
+	return eid;
+}
+
 #endif /* CONFIG_NATIVE_WINDOWS */
diff --git a/src/ap/ieee802_11.h b/src/ap/ieee802_11.h
index ea8c60846..466938f59 100644
--- a/src/ap/ieee802_11.h
+++ b/src/ap/ieee802_11.h
@@ -119,6 +119,8 @@  u8 * hostapd_eid_time_zone(struct hostapd_data *hapd, u8 *eid);
 int hostapd_update_time_adv(struct hostapd_data *hapd);
 void hostapd_client_poll_ok(struct hostapd_data *hapd, const u8 *addr);
 u8 * hostapd_eid_bss_max_idle_period(struct hostapd_data *hapd, u8 *eid);
+u8 * hostapd_eid_multiple_bssid(struct hostapd_data *hapd, u8 *eid, u8 *end);
+int hostapd_eid_multiple_bssid_len(struct hostapd_data *hapd);
 
 int auth_sae_init_committed(struct hostapd_data *hapd, struct sta_info *sta);
 #ifdef CONFIG_SAE
@@ -194,5 +196,6 @@  int get_tx_parameters(struct sta_info *sta, int ap_max_chanwidth,
 
 void auth_sae_process_commit(void *eloop_ctx, void *user_ctx);
 u8 * hostapd_eid_rsnxe(struct hostapd_data *hapd, u8 *eid, size_t len);
+u8 * hostapd_get_rsne(struct hostapd_data *hapd, u8 *pos, size_t len);
 
 #endif /* IEEE802_11_H */
diff --git a/src/ap/ieee802_11_shared.c b/src/ap/ieee802_11_shared.c
index 79ed450e2..961e91e66 100644
--- a/src/ap/ieee802_11_shared.c
+++ b/src/ap/ieee802_11_shared.c
@@ -356,6 +356,8 @@  static void hostapd_ext_capab_byte(struct hostapd_data *hapd, u8 *pos, int idx)
 			*pos |= 0x02; /* Bit 17 - WNM-Sleep Mode */
 		if (hapd->conf->bss_transition)
 			*pos |= 0x08; /* Bit 19 - BSS Transition */
+		if (hapd->iconf->multiple_bssid)
+                        *pos |= 0x40; /* Bit 22 - Multiple BSSID */
 		break;
 	case 3: /* Bits 24-31 */
 #ifdef CONFIG_WNM_AP
diff --git a/src/common/ieee802_11_defs.h b/src/common/ieee802_11_defs.h
index 4d3037eee..7d1287763 100644
--- a/src/common/ieee802_11_defs.h
+++ b/src/common/ieee802_11_defs.h
@@ -452,6 +452,8 @@ 
 #define WLAN_EID_RSNX 244
 #define WLAN_EID_EXTENSION 255
 
+#define WLAN_EID_SUBELEMENT_NONTRANSMITTED_BSSID_PROFILE 0
+
 /* Element ID Extension (EID 255) values */
 #define WLAN_EID_EXT_ASSOC_DELAY_INFO 1
 #define WLAN_EID_EXT_FILS_REQ_PARAMS 2