[PATCH wireless-next 6/8] wifi: wlcore: add pn16 support

From: Russell King (Oracle)
Date: Tue May 28 2024 - 05:19:49 EST


TI Wl18xx firmware adds a "pn16" field for AES and TKIP keys as per
their patch:

https://git.ti.com/cgit/wilink8-wlan/build-utilites/tree/patches/kernel_patches/4.19.38/0023-wlcore-Fixing-PN-drift-on-encrypted-link-after-recov.patch?h=r8.9&id=a2ee50aa5190ed3b334373d6cd09b1bff56ffcf7

Add support for this, but rather than requiring the field to be
present (which would break existing firmwares), make it optional.

Signed-off-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx>
---
drivers/net/wireless/ti/wlcore/cmd.c | 9 +++
drivers/net/wireless/ti/wlcore/main.c | 89 +++++++++++++++++++++--
drivers/net/wireless/ti/wlcore/wlcore_i.h | 4 +
3 files changed, 97 insertions(+), 5 deletions(-)

diff --git a/drivers/net/wireless/ti/wlcore/cmd.c b/drivers/net/wireless/ti/wlcore/cmd.c
index a939fd89a7f5..0d1fcdca3869 100644
--- a/drivers/net/wireless/ti/wlcore/cmd.c
+++ b/drivers/net/wireless/ti/wlcore/cmd.c
@@ -332,6 +332,14 @@ int wl12xx_allocate_link(struct wl1271 *wl, struct wl12xx_vif *wlvif, u8 *hlid)
wl->fw_status->counters.tx_lnk_free_pkts[link];
wl->links[link].wlvif = wlvif;

+ /*
+ * Take the last sec_pn16 value from the current FW status. On recovery,
+ * we might not have fw_status yet, and tx_lnk_sec_pn16[] will be NULL.
+ */
+ if (wl->fw_status->counters.tx_lnk_sec_pn16)
+ wl->links[link].prev_sec_pn16 =
+ le16_to_cpu(wl->fw_status->counters.tx_lnk_sec_pn16[link]);
+
/*
* Take saved value for total freed packets from wlvif, in case this is
* recovery/resume
@@ -360,6 +368,7 @@ void wl12xx_free_link(struct wl1271 *wl, struct wl12xx_vif *wlvif, u8 *hlid)

wl->links[*hlid].allocated_pkts = 0;
wl->links[*hlid].prev_freed_pkts = 0;
+ wl->links[*hlid].prev_sec_pn16 = 0;
wl->links[*hlid].ba_bitmap = 0;
eth_zero_addr(wl->links[*hlid].addr);

diff --git a/drivers/net/wireless/ti/wlcore/main.c b/drivers/net/wireless/ti/wlcore/main.c
index 8f82666f379c..35d1114a28aa 100644
--- a/drivers/net/wireless/ti/wlcore/main.c
+++ b/drivers/net/wireless/ti/wlcore/main.c
@@ -379,6 +379,8 @@ static void wl12xx_irq_update_links_status(struct wl1271 *wl,

static int wlcore_fw_status(struct wl1271 *wl, struct wl_fw_status *status)
{
+ struct wl12xx_vif *wlvifsta;
+ struct wl12xx_vif *wlvifap;
struct wl12xx_vif *wlvif;
u32 old_tx_blk_count = wl->tx_blocks_available;
int avail, freed_blocks;
@@ -410,23 +412,100 @@ static int wlcore_fw_status(struct wl1271 *wl, struct wl_fw_status *status)
wl->tx_pkts_freed[i] = status->counters.tx_released_pkts[i];
}

+ /* Find an authorized STA vif */
+ wlvifsta = NULL;
+ wl12xx_for_each_wlvif_sta(wl, wlvif) {
+ if (wlvif->sta.hlid != WL12XX_INVALID_LINK_ID &&
+ test_bit(WLVIF_FLAG_STA_AUTHORIZED, &wlvif->flags)) {
+ wlvifsta = wlvif;
+ break;
+ }
+ }
+
+ /* Find a started AP vif */
+ wlvifap = NULL;
+ wl12xx_for_each_wlvif(wl, wlvif) {
+ if (wlvif->bss_type == BSS_TYPE_AP_BSS &&
+ wlvif->inconn_count == 0 &&
+ test_bit(WLVIF_FLAG_AP_STARTED, &wlvif->flags)) {
+ wlvifap = wlvif;
+ break;
+ }
+ }

for_each_set_bit(i, wl->links_map, wl->num_links) {
+ u16 diff16, sec_pn16;
u8 diff, tx_lnk_free_pkts;
+
lnk = &wl->links[i];

/* prevent wrap-around in freed-packets counter */
tx_lnk_free_pkts = status->counters.tx_lnk_free_pkts[i];
diff = (tx_lnk_free_pkts - lnk->prev_freed_pkts) & 0xff;

- if (diff == 0)
+ if (diff) {
+ lnk->allocated_pkts -= diff;
+ lnk->prev_freed_pkts = tx_lnk_free_pkts;
+ }
+
+ /* Get the current sec_pn16 value if present */
+ if (status->counters.tx_lnk_sec_pn16)
+ sec_pn16 = __le16_to_cpu(status->counters.tx_lnk_sec_pn16[i]);
+ else
+ sec_pn16 = 0;
+ /* prevent wrap-around in pn16 counter */
+ diff16 = (sec_pn16 - lnk->prev_sec_pn16) & 0xffff;
+
+ /* FIXME: since free_pkts is a 8-bit counter of packets that
+ * rolls over, it can become zero. If it is zero, then we
+ * omit processing below. Is that really correct?
+ */
+ if (tx_lnk_free_pkts <= 0)
continue;

- lnk->allocated_pkts -= diff;
- lnk->prev_freed_pkts = tx_lnk_free_pkts;
+ /* For a station that has an authorized link: */
+ if (wlvifsta && wlvifsta->sta.hlid == i) {
+ if (wlvifsta->encryption_type == KEY_TKIP ||
+ wlvifsta->encryption_type == KEY_AES) {
+ if (diff16) {
+ lnk->prev_sec_pn16 = sec_pn16;
+ /* accumulate the prev_freed_pkts
+ * counter according to the PN from
+ * firmware
+ */
+ lnk->total_freed_pkts += diff16;
+ }
+ } else {
+ if (diff)
+ /* accumulate the prev_freed_pkts
+ * counter according to the free packets
+ * count from firmware
+ */
+ lnk->total_freed_pkts += diff;
+ }
+ }

- /* accumulate the prev_freed_pkts counter */
- lnk->total_freed_pkts += diff;
+ /* For an AP that has been started */
+ if (wlvifap && test_bit(i, wlvifap->ap.sta_hlid_map)) {
+ if (wlvifap->encryption_type == KEY_TKIP ||
+ wlvifap->encryption_type == KEY_AES) {
+ if (diff16) {
+ lnk->prev_sec_pn16 = sec_pn16;
+ /* accumulate the prev_freed_pkts
+ * counter according to the PN from
+ * firmware
+ */
+ lnk->total_freed_pkts += diff16;
+ }
+ } else {
+ if (diff)
+ /* accumulate the prev_freed_pkts
+ * counter according to the free packets
+ * count from firmware
+ */
+ lnk->total_freed_pkts += diff;
+ }
+ }
}

/* prevent wrap-around in total blocks counter */
diff --git a/drivers/net/wireless/ti/wlcore/wlcore_i.h b/drivers/net/wireless/ti/wlcore/wlcore_i.h
index eefae3f867b9..5fbed64302f1 100644
--- a/drivers/net/wireless/ti/wlcore/wlcore_i.h
+++ b/drivers/net/wireless/ti/wlcore/wlcore_i.h
@@ -151,6 +151,9 @@ struct wl_fw_status {
*/
u8 *tx_lnk_free_pkts;

+ /* PN16 of last TKIP/AES seq-num per HLID */
+ __le16 *tx_lnk_sec_pn16;
+
/* Cumulative counter of released Voice memory blocks */
u8 tx_voice_released_blks;

@@ -259,6 +262,7 @@ struct wl1271_link {
/* accounting for allocated / freed packets in FW */
u8 allocated_pkts;
u8 prev_freed_pkts;
+ u16 prev_sec_pn16;

u8 addr[ETH_ALEN];

--
2.30.2