[PATCH 19/50] AP: Support building basic Multi-Link Element
Andrei Otcheretianski
andrei.otcheretianski at intel.com
Wed Feb 15 15:08:33 PST 2023
Define a struct to hold MLD station info and implement publishing of the
basic Multi-Link Element. Add it into beacons and probe responses.
Signed-off-by: Andrei Otcheretianski <andrei.otcheretianski at intel.com>
---
src/ap/beacon.c | 23 +++++
src/ap/ieee802_11.h | 2 +
src/ap/ieee802_11_eht.c | 192 +++++++++++++++++++++++++++++++++++
src/ap/sta_info.h | 34 +++++++
src/common/ieee802_11_defs.h | 10 ++
5 files changed, 261 insertions(+)
diff --git a/src/ap/beacon.c b/src/ap/beacon.c
index c7ebc55347..94d68f6e70 100644
--- a/src/ap/beacon.c
+++ b/src/ap/beacon.c
@@ -585,6 +585,14 @@ static u8 * hostapd_gen_probe_resp(struct hostapd_data *hapd,
if (hapd->iconf->ieee80211be && !hapd->conf->disable_11be) {
buflen += hostapd_eid_eht_capab_len(hapd, IEEE80211_MODE_AP);
buflen += 3 + sizeof(struct ieee80211_eht_operation);
+
+ /*
+ * TODO: multi link AP has variable length and can be
+ * long based on the common info and number of per
+ * station profiles. For now use 256.
+ */
+ if (hapd->conf->mld_ap)
+ buflen += 256;
}
#endif /* CONFIG_IEEE80211BE */
@@ -727,6 +735,9 @@ static u8 * hostapd_gen_probe_resp(struct hostapd_data *hapd,
#ifdef CONFIG_IEEE80211BE
if (hapd->iconf->ieee80211be && !hapd->conf->disable_11be) {
+ if (hapd->conf->mld_ap)
+ pos = hostapd_eid_eht_basic_ml(hapd, pos, NULL, true);
+
pos = hostapd_eid_eht_capab(hapd, pos, IEEE80211_MODE_AP);
pos = hostapd_eid_eht_operation(hapd, pos);
}
@@ -1655,6 +1666,14 @@ int ieee802_11_build_ap_params(struct hostapd_data *hapd,
if (hapd->iconf->ieee80211be && !hapd->conf->disable_11be) {
tail_len += hostapd_eid_eht_capab_len(hapd, IEEE80211_MODE_AP);
tail_len += 3 + sizeof(struct ieee80211_eht_operation);
+
+ /*
+ * TODO: multi link AP has variable length and can be
+ * long based on the common info and number of per
+ * station profiles. For now use 256.
+ */
+ if (hapd->conf->mld_ap)
+ tail_len += 256;
}
#endif /* CONFIG_IEEE80211BE */
@@ -1825,6 +1844,10 @@ int ieee802_11_build_ap_params(struct hostapd_data *hapd,
#ifdef CONFIG_IEEE80211BE
if (hapd->iconf->ieee80211be && !hapd->conf->disable_11be) {
+ if (hapd->conf->mld_ap)
+ tailpos = hostapd_eid_eht_basic_ml(hapd, tailpos, NULL,
+ true);
+
tailpos = hostapd_eid_eht_capab(hapd, tailpos,
IEEE80211_MODE_AP);
tailpos = hostapd_eid_eht_operation(hapd, tailpos);
diff --git a/src/ap/ieee802_11.h b/src/ap/ieee802_11.h
index 5f443fcb8a..a5b33e7a89 100644
--- a/src/ap/ieee802_11.h
+++ b/src/ap/ieee802_11.h
@@ -83,6 +83,8 @@ void hostapd_get_eht_capab(struct hostapd_data *hapd,
const struct ieee80211_eht_capabilities *src,
struct ieee80211_eht_capabilities *dest,
size_t len);
+u8 *hostapd_eid_eht_basic_ml(struct hostapd_data *hapd, u8 *eid,
+ struct sta_info *info, bool include_mld_id);
int hostapd_get_aid(struct hostapd_data *hapd, struct sta_info *sta);
u16 copy_sta_ht_capab(struct hostapd_data *hapd, struct sta_info *sta,
const u8 *ht_capab);
diff --git a/src/ap/ieee802_11_eht.c b/src/ap/ieee802_11_eht.c
index caaadcecf0..d5d37995ce 100644
--- a/src/ap/ieee802_11_eht.c
+++ b/src/ap/ieee802_11_eht.c
@@ -408,3 +408,195 @@ void hostapd_get_eht_capab(struct hostapd_data *hapd,
os_memset(dest, 0, sizeof(*dest));
os_memcpy(dest, src, len);
}
+
+u8 *hostapd_eid_eht_basic_ml(struct hostapd_data *hapd, u8 *eid,
+ struct sta_info *info, bool include_mld_id)
+{
+ struct wpabuf *buf;
+ u16 control;
+ u8 *pos = eid;
+ const u8 *ptr;
+ size_t len, slice_len;
+ u8 link_id;
+ u8 common_info_len;
+
+ /*
+ * As the ML element can exceed the size of 244 bytes need to first
+ * build it and then handle defragmentation
+ */
+ buf = wpabuf_alloc(1024);
+ if (!buf)
+ return pos;
+
+ /* set the multi-link control field */
+ control = MULTI_LINK_CONTROL_TYPE_BASIC |
+ BASIC_MULTI_LINK_CTRL_PRES_LINK_ID |
+ BASIC_MULTI_LINK_CTRL_PRES_BSS_PARAM_CH_COUNT |
+ BASIC_MULTI_LINK_CTRL_PRES_EML_CAPA |
+ BASIC_MULTI_LINK_CTRL_PRES_MLD_CAPA;
+
+ /*
+ * set the basic multi-link common information. Hard code the common
+ * info length to 13 based on the length of the present fields:
+ * Length (1) + MLD address (6) + Link ID (1) +
+ * BSS change parameter (1) + MLD EML capabilities (2) +
+ * MLD MLD capabilities (2)
+ */
+ common_info_len = 13;
+
+ if (include_mld_id) {
+ control |= BASIC_MULTI_LINK_CTRL_PRES_AP_MLD_ID;
+ common_info_len++;
+ }
+
+ wpabuf_put_le16(buf, control);
+
+ wpabuf_put_u8(buf, common_info_len);
+
+ /* own MLD address */
+ wpabuf_put_data(buf, hapd->mld_addr, ETH_ALEN);
+
+ /* own link ID */
+ wpabuf_put_u8(buf, hapd->conf->mld_link_id);
+
+ /* currently hard code the BSS change parameters to 0x1 */
+ wpabuf_put_u8(buf, 0x1);
+
+ wpa_printf(MSG_DEBUG, "MLD: EML capabilities=0x%x",
+ hapd->conf->mld_eml_capa);
+
+ wpabuf_put_le16(buf, hapd->conf->mld_eml_capa);
+
+ wpa_printf(MSG_DEBUG, "MLD: MLD capabilities=0x%x",
+ hapd->conf->mld_mld_capa);
+
+ wpabuf_put_le16(buf, hapd->conf->mld_mld_capa);
+
+ if (include_mld_id) {
+ wpa_printf(MSG_DEBUG, "MLD: MLD ID=0x%x", hapd->conf->mld_id);
+ wpabuf_put_u8(buf, hapd->conf->mld_id);
+ }
+
+ if (!info)
+ goto out;
+
+ /* Add link info for the other links */
+ for (link_id = 0; link_id < MAX_NUM_MLD_LINKS; link_id++) {
+ struct mld_link_info *link = &info->mld_info.links[link_id];
+ /*
+ * control (2) + station info length (1) + MAC address (6) +
+ * beacon interval (2) + TSF offset (8) + DTIM info (2) + BSS
+ * parameters change counter (1) + station profile length.
+ */
+ const size_t fixed_len = 22;
+ size_t total_len = fixed_len + link->resp_sta_profile_len;
+
+ /* skip the local one */
+ if (link_id == hapd->conf->mld_link_id || !link->valid)
+ continue;
+
+ wpabuf_put_u8(buf, EHT_ML_SUB_ELEM_PER_STA_PROFILE);
+
+ if (total_len <= 255)
+ wpabuf_put_u8(buf, total_len);
+ else
+ wpabuf_put_u8(buf, 255);
+
+ control = (link_id & 0xf) |
+ EHT_PER_STA_CTRL_MAC_ADDR_PRESENT_MSK |
+ EHT_PER_STA_CTRL_COMPLETE_PROFILE_MSK |
+ EHT_PER_STA_CTRL_TSF_OFFSET_PRESENT_MSK |
+ EHT_PER_STA_CTRL_BEACON_INTERVAL_PRESENT_MSK |
+ EHT_PER_STA_CTRL_DTIM_INFO_PRESENT_MSK |
+ EHT_PER_STA_CTRL_BSS_PARAM_CNT_PRESENT_MSK;
+
+ wpabuf_put_le16(buf, control);
+
+ /* STA info length */
+ wpabuf_put_u8(buf, fixed_len - 2);
+
+ wpabuf_put_data(buf, link->local_addr, ETH_ALEN);
+
+ /* TODO: currently assume same beacon interval */
+ wpabuf_put_le16(buf, hapd->iconf->beacon_int);
+
+ /*
+ * TODO: currently setting TSF offset to zero. However this
+ * information needs to come from the driver
+ */
+ wpabuf_put_le32(buf, 0);
+ wpabuf_put_le32(buf, 0);
+
+ /* TODO: currently assume same DTIM information */
+ wpabuf_put_le16(buf, hapd->conf->dtim_period);
+
+ /* TODO: currently hard code the BSS change parameters to 0x1 */
+ wpabuf_put_u8(buf, 0x1);
+
+ /* Fragment the sub element if needed */
+ if (total_len <= 255) {
+ wpabuf_put_data(buf, link->resp_sta_profile,
+ link->resp_sta_profile_len);
+ } else {
+ ptr = link->resp_sta_profile;
+ len = link->resp_sta_profile_len;
+
+ slice_len = 255 - fixed_len;
+
+ wpabuf_put_data(buf, ptr, slice_len);
+ len -= slice_len;
+ ptr += slice_len;
+
+ while (len) {
+ if (len <= 255)
+ slice_len = len;
+ else
+ slice_len = 255;
+
+ wpabuf_put_u8(buf, EHT_ML_SUB_ELEM_FRAGMENT);
+ wpabuf_put_u8(buf, slice_len);
+ wpabuf_put_data(buf, ptr, slice_len);
+
+ len -= slice_len;
+ ptr += slice_len;
+ }
+ }
+ }
+
+out:
+ /* start the fragmentation */
+ len = wpabuf_len(buf);
+ ptr = wpabuf_head(buf);
+
+ if (len <= 254)
+ slice_len = len;
+ else
+ slice_len = 254;
+
+ *pos++ = WLAN_EID_EXTENSION;
+ *pos++ = slice_len + 1;
+ *pos++ = WLAN_EID_EXT_MULTI_LINK;
+ os_memcpy(pos, ptr, slice_len);
+
+ ptr += slice_len;
+ pos += slice_len;
+ len -= slice_len;
+
+ while (len) {
+ if (len <= 255)
+ slice_len = len;
+ else
+ slice_len = 255;
+
+ *pos++ = WLAN_EID_FRAGMENT;
+ *pos++ = slice_len;
+ os_memcpy(pos, ptr, slice_len);
+
+ ptr += slice_len;
+ pos += slice_len;
+ len -= slice_len;
+ }
+
+ wpabuf_free(buf);
+ return pos;
+}
diff --git a/src/ap/sta_info.h b/src/ap/sta_info.h
index b59b7584b3..06e68133bb 100644
--- a/src/ap/sta_info.h
+++ b/src/ap/sta_info.h
@@ -69,6 +69,35 @@ struct pending_eapol_rx {
enum frame_encryption encrypted;
};
+#define EHT_ML_MAX_STA_PROF_LEN 1024
+struct mld_info {
+ bool mld_sta;
+
+ struct ml_common_info {
+ u8 mld_addr[ETH_ALEN];
+ u16 medium_sync_delay;
+ u16 eml_capa;
+ u16 mld_capa;
+ } common_info;
+
+ struct mld_link_info {
+ u8 valid;
+ u8 local_addr[ETH_ALEN];
+ u8 peer_addr[ETH_ALEN];
+
+ size_t nstr_bitmap_len;
+ u8 nstr_bitmap[2];
+
+ u16 capability;
+
+ u16 status;
+ size_t resp_sta_profile_len;
+ u8 resp_sta_profile[EHT_ML_MAX_STA_PROF_LEN];
+
+ const u8 *rsne, *rsnxe;
+ } links[MAX_NUM_MLD_LINKS];
+};
+
struct sta_info {
struct sta_info *next; /* next entry in sta list */
struct sta_info *hnext; /* next entry in hash table list */
@@ -299,6 +328,11 @@ struct sta_info {
#ifdef CONFIG_PASN
struct pasn_data *pasn;
#endif /* CONFIG_PASN */
+
+#ifdef CONFIG_IEEE80211BE
+ struct mld_info mld_info;
+ u8 mld_assoc_link_id;
+#endif /* CONFIG_IEEE80211BE */
};
diff --git a/src/common/ieee802_11_defs.h b/src/common/ieee802_11_defs.h
index 12ddad466f..45f03a8351 100644
--- a/src/common/ieee802_11_defs.h
+++ b/src/common/ieee802_11_defs.h
@@ -2623,6 +2623,16 @@ struct eht_ml_basic_common_info {
#define EHT_ML_MLD_CAPA_FREQ_SEP_FOR_STR_MASK 0x0f80
#define EHT_ML_MLD_CAPA_AAR_SUPP 0x1000
+#define EHT_PER_STA_CTRL_LINK_ID_MSK 0x000f
+#define EHT_PER_STA_CTRL_COMPLETE_PROFILE_MSK 0x0010
+#define EHT_PER_STA_CTRL_MAC_ADDR_PRESENT_MSK 0x0020
+#define EHT_PER_STA_CTRL_BEACON_INTERVAL_PRESENT_MSK 0x0040
+#define EHT_PER_STA_CTRL_TSF_OFFSET_PRESENT_MSK 0x0080
+#define EHT_PER_STA_CTRL_DTIM_INFO_PRESENT_MSK 0x0100
+#define EHT_PER_STA_CTRL_NSTR_LINK_PAIR_PRESENT_MSK 0x0200
+#define EHT_PER_STA_CTRL_NSTR_BM_SIZE_MSK 0x0400
+#define EHT_PER_STA_CTRL_BSS_PARAM_CNT_PRESENT_MSK 0x0800
+
/* IEEE P802.11be/D2.0, 9.4.2.312.2.4 - Per-STA Profile subelement format */
struct ieee80211_eht_per_sta_profile {
le16 sta_control;
--
2.38.1
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