[PATCH 1/4] wiphy: add wiphy_get_frequency_info_list

[PATCH 1/4] wiphy: add wiphy_get_frequency_info_list

[James Prestwood]

Gets the entire list of frequency attributes advertised. This is
needed for AP mode to create a country IE which includes subband
triplet fields.
---
 src/wiphy.c | 17 +++++++++++++++++
 src/wiphy.h |  5 +++++
 2 files changed, 22 insertions(+)

diff --git a/src/wiphy.c b/src/wiphy.c
index 4ff3085a..9ca651f4 100644
--- a/src/wiphy.c
+++ b/src/wiphy.c
@@ -526,6 +526,23 @@ const struct band_freq_attrs *wiphy_get_frequency_info(
 	return attr;
 }
 
+const struct band_freq_attrs *wiphy_get_frequency_info_list(
+						const struct wiphy *wiphy,
+						enum band_freq band,
+						size_t *size)
+{
+	struct band *bandp;
+
+	bandp = wiphy_get_band(wiphy, band);
+	if (!bandp)
+		return NULL;
+
+	if (size)
+		*size = bandp->freqs_len;
+
+	return bandp->freq_attrs;
+}
+
 bool wiphy_band_is_disabled(const struct wiphy *wiphy, enum band_freq band)
 {
 	struct band_freq_attrs attr;
diff --git a/src/wiphy.h b/src/wiphy.h
index 1056ac0c..d5d1cc8f 100644
--- a/src/wiphy.h
+++ b/src/wiphy.h
@@ -104,6 +104,11 @@ const struct scan_freq_set *wiphy_get_supported_freqs(
 const struct band_freq_attrs *wiphy_get_frequency_info(
 						const struct wiphy *wiphy,
 						uint32_t freq);
+const struct band_freq_attrs *wiphy_get_frequency_info_list(
+						const struct wiphy *wiphy,
+						enum band_freq band,
+						size_t *size);
+
 bool wiphy_band_is_disabled(const struct wiphy *wiphy, enum band_freq band);
 
 bool wiphy_supports_probe_resp_offload(struct wiphy *wiphy);
-- 
2.34.3

[PATCH 2/4] band: add tx_power to frequency info attributes

[James Prestwood]

---
 src/band.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/band.h b/src/band.h
index 676c63d9..b94c07d3 100644
--- a/src/band.h
+++ b/src/band.h
@@ -56,6 +56,7 @@ struct band_he_capabilities {
 };
 
 struct band_freq_attrs {
+	uint8_t tx_power;
 	bool supported : 1;
 	bool disabled : 1;
 	bool no_ir : 1;
-- 
2.34.3

[PATCH 3/4] nl80211util: parse TX power in frequency attributes

[James Prestwood]

---
 src/nl80211util.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/nl80211util.c b/src/nl80211util.c
index 400871fd..8cc3ea39 100644
--- a/src/nl80211util.c
+++ b/src/nl80211util.c
@@ -548,6 +548,9 @@ int nl80211_parse_supported_frequencies(struct l_genl_attr *band_freqs,
 			case NL80211_FREQUENCY_ATTR_NO_HE:
 				freq_attr.no_he = true;
 				break;
+			case NL80211_FREQUENCY_ATTR_MAX_TX_POWER:
+				freq_attr.tx_power = *((uint32_t *) data) / 100;
+				break;
 			}
 		}
 
-- 
2.34.3

[PATCH 4/4] ap: support setting country IE

[James Prestwood]

This adds a builder which sets the country IE in probes/beacons.
The IE will use the 'single subband triplet sequence' meaning
dot11OperatingClassesRequired is false. This is much easier to
build and doesn't require knowing an operating class.

The IE itself is variable in length and potentially could grow
large if the hardware has a weird configuration (many different
power levels or segmentation in supported channels) so the
overall builder was changed to take the length of the buffer and
warnings will be printed if any space issues are encountered.
---
 src/ap.c | 134 ++++++++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 118 insertions(+), 16 deletions(-)

diff --git a/src/ap.c b/src/ap.c
index a989c454..1d937103 100644
--- a/src/ap.c
+++ b/src/ap.c
@@ -1061,22 +1061,123 @@ static size_t ap_build_beacon_pr_head(struct ap_state *ap,
 	return 36 + out_len;
 }
 
+static size_t ap_build_country_ie(struct ap_state *ap, uint8_t *out_buf,
+					size_t buf_len)
+{
+	size_t len;
+	size_t i;
+	int spacing;
+	uint8_t *pos = out_buf;
+	uint8_t nchans = 1;
+	struct wiphy *wiphy = netdev_get_wiphy(ap->netdev);
+	const struct band_freq_attrs *last = NULL;
+	const struct band_freq_attrs *list = wiphy_get_frequency_info_list(
+							wiphy, ap->band, &len);
+
+	if (!list || wiphy_country_is_unknown(wiphy))
+		return 0;
+
+	if (L_WARN_ON(buf_len < 5))
+		goto no_space;
+
+	*pos++ = IE_TYPE_COUNTRY;
+	/* length not yet known */
+	pos++;
+
+	wiphy_get_reg_domain_country(wiphy, (char *)pos);
+	pos += 2;
+	*pos++ = ' ';
+
+	buf_len -= 5;
+
+	if (ap->band == BAND_FREQ_2_4_GHZ)
+		spacing = 1;
+	else
+		spacing = 4;
+
+	/*
+	 * Construct a list of subband triplet entries. Each entry contains a
+	 * starting channel and a number of channels which are spaced evenly
+	 * and use the same TX power. Any deviation from this results in a new
+	 * channel group.
+	 *
+	 * TODO: 6Ghz requires operating triplets, not subband triplets.
+	 */
+	for (i = 0; i < len; i++) {
+		const struct band_freq_attrs *attr = &list[i];
+
+		if (!attr->supported || attr->disabled)
+			continue;
+
+		if (!last) {
+			/* Room for one complete triplet */
+			if (L_WARN_ON(buf_len < 3))
+				goto no_space;
+
+			*pos++ = i;
+			last = attr;
+			continue;
+		}
+
+		if (spacing != attr - last ||
+					attr->tx_power != last->tx_power) {
+			/* finish current group */
+			*pos++ = nchans;
+			*pos++ = last->tx_power;
+			buf_len -= 3;
+
+			/* start a new group */
+			if (L_WARN_ON(buf_len < 3))
+				goto no_space;
+
+			*pos++ = i;
+			nchans = 1;
+		} else
+			nchans++;
+
+		last = attr;
+	}
+
+	/* finish final group */
+	*pos++ = nchans;
+	*pos++ = last->tx_power;
+
+	len = pos - out_buf - 2;
+
+	/* Pad to even byte */
+	if (len & 1) {
+		if (L_WARN_ON(buf_len < 1))
+			goto no_space;
+
+		*pos++ = 0;
+		len++;
+	}
+
+	out_buf[1] = len;
+
+	return out_buf[1] + 2;
+
+no_space:
+	return 0;
+}
+
 /* Beacon / Probe Response frame portion after the TIM IE */
 static size_t ap_build_beacon_pr_tail(struct ap_state *ap,
 					enum mpdu_management_subtype stype,
 					const struct mmpdu_header *req,
-					size_t req_len, uint8_t *out_buf)
+					size_t req_len, uint8_t *out_buf,
+					size_t buf_len)
 {
 	size_t len;
 	struct ie_rsn_info rsn;
 
-	/* TODO: Country IE between TIM IE and RSNE */
+	len = ap_build_country_ie(ap, out_buf, buf_len);
 
 	/* RSNE */
 	ap_set_rsn_info(ap, &rsn);
-	if (!ie_build_rsne(&rsn, out_buf))
+	if (!ie_build_rsne(&rsn, out_buf + len))
 		return 0;
-	len = 2 + out_buf[1];
+	len += 2 + out_buf[len + 1];
 
 	len += ap_write_extra_ies(ap, stype, req, req_len, out_buf + len);
 	return len;
@@ -1094,11 +1195,11 @@ void ap_update_beacon(struct ap_state *ap)
 {
 	struct l_genl_msg *cmd;
 	uint8_t head[256];
-	L_AUTO_FREE_VAR(uint8_t *, tail) =
-		l_malloc(256 + ap_get_extra_ies_len(ap,
+	size_t tail_len = 256 + ap_get_extra_ies_len(ap,
 						MPDU_MANAGEMENT_SUBTYPE_BEACON,
-						NULL, 0));
-	size_t head_len, tail_len;
+						NULL, 0);
+	L_AUTO_FREE_VAR(uint8_t *, tail) = malloc(tail_len);
+	size_t head_len;
 	uint64_t wdev_id = netdev_get_wdev_id(ap->netdev);
 	static const uint8_t bcast_addr[6] = {
 		0xff, 0xff, 0xff, 0xff, 0xff, 0xff
@@ -1110,7 +1211,7 @@ void ap_update_beacon(struct ap_state *ap)
 	head_len = ap_build_beacon_pr_head(ap, MPDU_MANAGEMENT_SUBTYPE_BEACON,
 						bcast_addr, head, sizeof(head));
 	tail_len = ap_build_beacon_pr_tail(ap, MPDU_MANAGEMENT_SUBTYPE_BEACON,
-						NULL, 0, tail);
+						NULL, 0, tail, tail_len);
 	if (L_WARN_ON(!head_len || !tail_len))
 		return;
 
@@ -2294,7 +2395,7 @@ static void ap_probe_req_cb(const struct mmpdu_header *hdr, const void *body,
 	len += ap_build_beacon_pr_tail(ap,
 					MPDU_MANAGEMENT_SUBTYPE_PROBE_RESPONSE,
 					hdr, body + body_len - (void *) hdr,
-					resp + len);
+					resp + len, resp_len - len);
 
 	ap_send_mgmt_frame(ap, (struct mmpdu_header *) resp, len,
 				ap_probe_resp_cb, NULL);
@@ -2551,11 +2652,11 @@ static struct l_genl_msg *ap_build_cmd_start_ap(struct ap_state *ap)
 	struct l_genl_msg *cmd;
 
 	uint8_t head[256];
-	L_AUTO_FREE_VAR(uint8_t *, tail) =
-		l_malloc(256 + ap_get_extra_ies_len(ap,
+	size_t tail_len = 256 + ap_get_extra_ies_len(ap,
 						MPDU_MANAGEMENT_SUBTYPE_BEACON,
-						NULL, 0));
-	size_t head_len, tail_len;
+						NULL, 0);
+	L_AUTO_FREE_VAR(uint8_t *, tail) = l_malloc(tail_len);
+	size_t head_len;
 
 	uint32_t dtim_period = 3;
 	uint32_t ifindex = netdev_get_ifindex(ap->netdev);
@@ -2584,7 +2685,7 @@ static struct l_genl_msg *ap_build_cmd_start_ap(struct ap_state *ap)
 	head_len = ap_build_beacon_pr_head(ap, MPDU_MANAGEMENT_SUBTYPE_BEACON,
 						bcast_addr, head, sizeof(head));
 	tail_len = ap_build_beacon_pr_tail(ap, MPDU_MANAGEMENT_SUBTYPE_BEACON,
-						NULL, 0, tail);
+						NULL, 0, tail, tail_len);
 
 	if (!head_len || !tail_len)
 		return NULL;
@@ -2632,7 +2733,8 @@ static struct l_genl_msg *ap_build_cmd_start_ap(struct ap_state *ap)
 					zero_addr, ptr, sizeof(probe_resp));
 		ptr += ap_build_beacon_pr_tail(ap,
 					MPDU_MANAGEMENT_SUBTYPE_PROBE_RESPONSE,
-					NULL, 0, ptr);
+					NULL, 0, ptr, sizeof(probe_resp) -
+					(ptr - probe_resp));
 
 		l_genl_msg_append_attr(cmd, NL80211_ATTR_PROBE_RESP,
 					ptr - probe_resp, probe_resp);
-- 
2.34.3

Re: [PATCH 1/4] wiphy: add wiphy_get_frequency_info_list

[Denis Kenzior]

Hi James,

On 12/30/22 16:12, James Prestwood wrote:
> Gets the entire list of frequency attributes advertised. This is
> needed for AP mode to create a country IE which includes subband
> triplet fields.
> ---
>   src/wiphy.c | 17 +++++++++++++++++
>   src/wiphy.h |  5 +++++
>   2 files changed, 22 insertions(+)
> 

All applied, thanks.

Regards,
-Denis