[RFC v2 21/99] NAN: Add potential availability entries
Andrei Otcheretianski
andrei.otcheretianski at intel.com
Tue Dec 23 03:51:25 PST 2025
From: Ilan Peer <ilan.peer at intel.com>
Add support for adding potential availability entries to
the availability attribute.
The potential availability entries are constructed using the
channels supported by the upper layer. These channels are
retrieved using a callback that is expected to provide
the supported channels and their preference for a given
map.
Signed-off-by: Ilan Peer <ilan.peer at intel.com>
---
src/nan/nan.h | 47 ++++++++++
src/nan/nan_util.c | 218 ++++++++++++++++++++++++++++++++++++++++++---
2 files changed, 252 insertions(+), 13 deletions(-)
diff --git a/src/nan/nan.h b/src/nan/nan.h
index 530bf83890..1555bad484 100644
--- a/src/nan/nan.h
+++ b/src/nan/nan.h
@@ -274,6 +274,29 @@ struct nan_ndp_action_notif_params {
size_t ssi_len;
};
+/**
+ * struct nan_channel_info - Channel information for NAN channel selection
+ * @op_class: Operating class
+ * @channel: Control channel index
+ * @pref: Channel Preference (higher is preferred). Valid values are 0-3.
+ */
+struct nan_channel_info {
+ u8 op_class;
+ u8 channel;
+ u8 pref;
+};
+
+/**
+ * struct nan_channels - Array of channel information entries
+ *
+ * @n_chans: Number of channel information entries
+ * @chans: Array of channel information. Sorted by preference.
+ */
+struct nan_channels {
+ size_t n_chans;
+ struct nan_channel_info *chans;
+};
+
struct nan_config {
void *cb_ctx;
@@ -336,6 +359,30 @@ struct nan_config {
void (*ndp_disconnected)(void *ctx, struct nan_ndp_id *ndp_id,
const u8 *local_ndi, const u8 *peer_ndi,
enum nan_reason reason);
+
+ /**
+ * get_chans - Get the prioritized allowed channel information to be
+ * used for building the potential availability entries associated with
+ * the given map id.
+ *
+ * @ctx: Callback context from cb_ctx
+ * @map_id: Map ID of the availability attribute for which
+ * the channels are requested.
+ * @chans: Pointer to a nan_channels structure that should be filled
+ * with the prioritized frequencies. On successful return the
+ * channels should be sorted having the higher priority channels
+ * first.
+ * Returns 0 on success, -1 on failure.
+ *
+ * Note: the callback is responsible for allocating chans->chans as
+ * needed. The caller (the NAN module) is responsible for freeing the
+ * memory allocated for the chans->chans.
+ *
+ * Note: The callback should add all channels that are considered valid
+ * for use by the NAN module for the given map.
+ */
+ int (*get_chans)(void *ctx, u8 map_id, struct nan_channels *chans);
+
};
struct nan_data * nan_init(const struct nan_config *cfg);
diff --git a/src/nan/nan_util.c b/src/nan/nan_util.c
index 57414cdc37..cf37545683 100644
--- a/src/nan/nan_util.c
+++ b/src/nan/nan_util.c
@@ -383,10 +383,7 @@ static u16 nan_add_avail_entry(struct nan_data *nan,
len_ptr = wpabuf_put(buf, 2);
- /*
- * TODO: Need to also add potential entries as otherwise the peer would
- * not be able to counter
- */
+ /* Potential availability entries are handled separately */
if (type != NAN_AVAIL_ENTRY_CTRL_TYPE_COMMITTED &&
type != NAN_AVAIL_ENTRY_CTRL_TYPE_COND) {
wpa_printf(MSG_DEBUG,
@@ -494,6 +491,152 @@ int nan_get_chan_bm(struct nan_data *nan, struct nan_sched_chan *chan,
}
+static void nan_add_pot_avail_entry(struct nan_data *nan,
+ struct nan_chan_entry *entries,
+ size_t n_entries, u8 pref,
+ struct wpabuf *buf)
+{
+ u16 ctrl;
+ u8 chan_ctrl;
+ size_t i;
+ u8 nss = BITS(nan->cfg->dev_capa.n_antennas, NAN_DEV_CAPA_RX_ANT_MASK,
+ NAN_DEV_CAPA_RX_ANT_POS);
+
+ wpa_printf(MSG_DEBUG, "NAN: Adding potential entry: n_entries=%zu",
+ n_entries);
+
+ if (!n_entries)
+ return;
+
+ /* The number of channel entries can be too big for the buffer */
+ if (wpabuf_tailroom(buf) < 2 + 2 + 1 + n_entries * 4) {
+ n_entries = (wpabuf_tailroom(buf) - 5) / 4;
+
+ wpa_printf(MSG_DEBUG,
+ "NAN: Not enough space to add potential entries, reduce to %zu",
+ n_entries);
+ }
+
+ /*
+ * ctrl (2) + chan control (1) + n_entries * (nan_chan_entry without
+ * the aux bitmap).
+ */
+ wpabuf_put_le16(buf, 3 + n_entries * 4);
+
+ ctrl = NAN_AVAIL_ENTRY_CTRL_TYPE_POTENTIAL;
+ ctrl |= NAN_AVAIL_ENTRY_DEF_UTIL << NAN_AVAIL_ENTRY_CTRL_UTIL_POS;
+ ctrl |= nss << NAN_AVAIL_ENTRY_CTRL_RX_NSS_POS;
+ ctrl |= pref << NAN_AVAIL_ENTRY_CTRL_USAGE_PREF_POS;
+ wpabuf_put_le16(buf, ctrl);
+
+ /* Add all channel entries */
+ chan_ctrl = NAN_BAND_CHAN_CTRL_TYPE;
+ chan_ctrl |= n_entries << NAN_BAND_CHAN_CTRL_NUM_ENTRIES_POS;
+ wpabuf_put_u8(buf, chan_ctrl);
+
+ for (i = 0; i < n_entries; i++) {
+ struct nan_chan_entry *cur = &entries[i];
+
+ wpabuf_put_u8(buf, cur->op_class);
+ wpabuf_put_le16(buf, cur->chan_bitmap);
+ wpabuf_put_u8(buf, 0);
+ }
+}
+
+
+static void
+nan_build_pot_avail_entry_with_chans(struct nan_data *nan,
+ struct nan_channels *pot_chans,
+ struct wpabuf *buf,
+ u8 map_id)
+{
+ struct nan_chan_entry chan_entries[global_op_class_size];
+ size_t i, n_entries;
+
+ os_memset(chan_entries, 0, sizeof(chan_entries));
+ n_entries = 0;
+
+ wpa_printf(MSG_DEBUG, "NAN: Adding potential entries: n_chans=%zu",
+ pot_chans->n_chans);
+
+ for (i = 0; i < pot_chans->n_chans; i++) {
+ struct nan_channel_info *chan = &pot_chans->chans[i];
+ struct nan_chan_entry *cur;
+ u16 cbm = 0;
+ size_t j;
+ int ret;
+
+ wpa_printf(MSG_DEBUG,
+ "NAN: Channel: op_class=%u, chan=%u, pref=%u",
+ chan->op_class, chan->channel, chan->pref);
+
+ if ((i > 0) && (pot_chans->chans[i - 1].pref != chan->pref)) {
+ nan_add_pot_avail_entry(nan, chan_entries, n_entries,
+ pot_chans->chans[i - 1].pref,
+ buf);
+
+ os_memset(chan_entries, 0, sizeof(chan_entries));
+ n_entries = 0;
+ }
+
+ ret = nan_chan_to_chan_idx_map(nan, chan->op_class,
+ chan->channel, &cbm);
+ if (ret)
+ continue;
+
+ /* Try to find and entry that matches the operating class */
+ for (j = 0, cur = NULL; j < n_entries; j++) {
+ cur = &chan_entries[j];
+
+ if (!cur->op_class ||
+ cur->op_class == chan->op_class)
+ break;
+ }
+
+ if (!n_entries)
+ cur = &chan_entries[n_entries++];
+ else if (j == n_entries && n_entries < global_op_class_size)
+ cur = &chan_entries[n_entries++];
+ else if (!cur)
+ continue;
+
+ cur->op_class = chan->op_class;
+ cur->chan_bitmap |= cbm;
+ }
+
+ if (n_entries)
+ nan_add_pot_avail_entry(nan, chan_entries, n_entries,
+ pot_chans->chans[i - 1].pref, buf);
+
+ wpa_printf(MSG_DEBUG, "NAN: Added potential entries: done");
+}
+
+
+static void nan_build_pot_avail_entry(struct nan_data *nan, struct wpabuf *buf,
+ u8 map_id)
+{
+ struct nan_channels pot_chans;
+
+ os_memset(&pot_chans, 0, sizeof(pot_chans));
+
+ if (nan->cfg->get_chans(nan->cfg->cb_ctx, map_id, &pot_chans) < 0) {
+ wpa_printf(MSG_DEBUG,
+ "NAN: Failed to get channels. Not adding potential");
+ return;
+ }
+
+ if (pot_chans.n_chans != 0)
+ nan_build_pot_avail_entry_with_chans(nan, &pot_chans,
+ buf, map_id);
+ else
+ wpa_printf(MSG_DEBUG,
+ "NAN: No channels available. Not adding potential: map_id=%u",
+ map_id);
+
+ os_free(pot_chans.chans);
+}
+
+
/**
* nan_add_avail_attrs - Add NAN availability attributes
* @nan: NAN module context from nan_init()
@@ -518,6 +661,7 @@ int nan_add_avail_attrs(struct nan_data *nan, u8 sequence_id,
struct wpabuf *buf)
{
u8 last_map_id = NAN_INVALID_MAP_ID;
+ u32 handled_map_ids = 0;
u8 *len_ptr = NULL;
u8 i;
@@ -568,12 +712,14 @@ int nan_add_avail_attrs(struct nan_data *nan, u8 sequence_id,
"NAN: Add avail attr done: map_id=%u",
last_map_id);
+ nan_build_pot_avail_entry(nan, buf,
+ last_map_id);
WPA_PUT_LE16(len_ptr,
(u8 *)wpabuf_put(buf, 0) - len_ptr - 2);
}
last_map_id = chan->map_id;
- map_ids_bitmap &= ~BIT(last_map_id);
+ handled_map_ids |= BIT(last_map_id);
wpa_printf(MSG_DEBUG, "NAN: Add avail attr map_id=%u",
last_map_id);
@@ -588,9 +734,11 @@ int nan_add_avail_attrs(struct nan_data *nan, u8 sequence_id,
* The spec states that this bit should be set if the
* committed changed or if conditional is included. Set
* it anyway, as it is not known what information the
- * peer has on our schedule.
+ * peer has on our schedule. Similarly, always set the
+ * potential changed bit.
*/
- ctrl |= NAN_AVAIL_CTRL_COMMITTED_CHANGED;
+ ctrl |= NAN_AVAIL_CTRL_COMMITTED_CHANGED |
+ NAN_AVAIL_CTRL_POTENTIAL_CHANGED;
wpabuf_put_le16(buf, ctrl);
}
@@ -607,16 +755,60 @@ int nan_add_avail_attrs(struct nan_data *nan, u8 sequence_id,
op_class, chan_bm, 0, buf);
}
- if (last_map_id == NAN_INVALID_MAP_ID) {
+ if (last_map_id != NAN_INVALID_MAP_ID) {
+ nan_build_pot_avail_entry(nan, buf, last_map_id);
+ WPA_PUT_LE16(len_ptr, (u8 *)wpabuf_put(buf, 0) - len_ptr - 2);
+
+ wpa_printf(MSG_DEBUG, "NAN: Add avail attr done: map_id=%u",
+ last_map_id);
+ } else {
wpa_printf(MSG_DEBUG,
- "NAN: No valid availability entries added");
- return -1;
+ "NAN: No committed/conditional entries were added");
}
- wpa_printf(MSG_DEBUG, "NAN: Add avail attr done: map_id=%u",
- last_map_id);
+ /*
+ * Add NAN availability attributes with a single potential availability
+ * entry for map IDs that are not included in the schedule
+ */
+ map_ids_bitmap &= ~handled_map_ids;
+ wpa_printf(MSG_DEBUG,
+ "NAN: Add avail attrs for remaining map IDs: bitmap=0x%x",
+ map_ids_bitmap);
- WPA_PUT_LE16(len_ptr, (u8 *)wpabuf_put(buf, 0) - len_ptr - 2);
+ while (map_ids_bitmap) {
+ struct nan_channels pot_chans;
+
+ u8 map_id = ffs(map_ids_bitmap) - 1;
+ u16 ctrl = map_id << NAN_AVAIL_CTRL_MAP_ID_POS |
+ NAN_AVAIL_CTRL_POTENTIAL_CHANGED;
+
+ map_ids_bitmap &= ~BIT(map_id);
+
+ wpa_printf(MSG_DEBUG, "NAN: Add avail attr for map_id=%u",
+ map_id);
+
+ os_memset(&pot_chans, 0, sizeof(pot_chans));
+
+ if (nan->cfg->get_chans(nan->cfg->cb_ctx, map_id,
+ &pot_chans) < 0 ||
+ !pot_chans.chans) {
+ wpa_printf(MSG_DEBUG,
+ "NAN: No channels available. Not adding potential: map_id=%u",
+ map_id);
+ continue;
+ }
+
+ wpabuf_put_u8(buf, NAN_ATTR_NAN_AVAILABILITY);
+ len_ptr = wpabuf_put(buf, 2);
+ wpabuf_put_u8(buf, sequence_id);
+ wpabuf_put_le16(buf, ctrl);
+
+ nan_build_pot_avail_entry_with_chans(nan, &pot_chans, buf,
+ map_id);
+ os_free(pot_chans.chans);
+
+ WPA_PUT_LE16(len_ptr, (u8 *)wpabuf_put(buf, 0) - len_ptr - 2);
+ }
return 0;
}
--
2.49.0
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