drivers/staging/wfx/data_rx.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Datapath implementation.
   4  *
   5  * Copyright (c) 2017-2019, Silicon Laboratories, Inc.
   6  * Copyright (c) 2010, ST-Ericsson
   7  */
   8 #include <linux/etherdevice.h>
   9 #include <net/mac80211.h>
  10
  11 #include "data_rx.h"
  12 #include "wfx.h"
  13 #include "bh.h"
  14 #include "sta.h"
  15
  16 static int wfx_drop_encrypt_data(struct wfx_dev *wdev,
  17                                  const struct hif_ind_rx *arg,
  18                                  struct sk_buff *skb)
  19 {
  20         struct ieee80211_hdr *frame = (struct ieee80211_hdr *)skb->data;
  21         size_t hdrlen = ieee80211_hdrlen(frame->frame_control);
  22         size_t iv_len, icv_len;
  23
  24         /* Oops... There is no fast way to ask mac80211 about
  25          * IV/ICV lengths. Even defineas are not exposed.
  26          */
  27         switch (arg->rx_flags.encryp) {
  28         case HIF_RI_FLAGS_WEP_ENCRYPTED:
  29                 iv_len = 4 /* WEP_IV_LEN */;
  30                 icv_len = 4 /* WEP_ICV_LEN */;
  31                 break;
  32         case HIF_RI_FLAGS_TKIP_ENCRYPTED:
  33                 iv_len = 8 /* TKIP_IV_LEN */;
  34                 icv_len = 4 /* TKIP_ICV_LEN */
  35                         + 8 /*MICHAEL_MIC_LEN*/;
  36                 break;
  37         case HIF_RI_FLAGS_AES_ENCRYPTED:
  38                 iv_len = 8 /* CCMP_HDR_LEN */;
  39                 icv_len = 8 /* CCMP_MIC_LEN */;
  40                 break;
  41         case HIF_RI_FLAGS_WAPI_ENCRYPTED:
  42                 iv_len = 18 /* WAPI_HDR_LEN */;
  43                 icv_len = 16 /* WAPI_MIC_LEN */;
  44                 break;
  45         default:
  46                 dev_err(wdev->dev, "unknown encryption type %d\n",
  47                         arg->rx_flags.encryp);
  48                 return -EIO;
  49         }
  50
  51         /* Firmware strips ICV in case of MIC failure. */
  52         if (arg->status == HIF_STATUS_MICFAILURE)
  53                 icv_len = 0;
  54
  55         if (skb->len < hdrlen + iv_len + icv_len) {
  56                 dev_warn(wdev->dev, "malformed SDU received\n");
  57                 return -EIO;
  58         }
  59
  60         /* Remove IV, ICV and MIC */
  61         skb_trim(skb, skb->len - icv_len);
  62         memmove(skb->data + iv_len, skb->data, hdrlen);
  63         skb_pull(skb, iv_len);
  64         return 0;
  65 }
  66
  67 void wfx_rx_cb(struct wfx_vif *wvif,
  68                const struct hif_ind_rx *arg, struct sk_buff *skb)
  69 {
  70         struct ieee80211_rx_status *hdr = IEEE80211_SKB_RXCB(skb);
  71         struct ieee80211_hdr *frame = (struct ieee80211_hdr *)skb->data;
  72         struct ieee80211_mgmt *mgmt = (struct ieee80211_mgmt *)skb->data;
  73
  74         memset(hdr, 0, sizeof(*hdr));
  75
  76         // FIXME: Why do we drop these frames?
  77         if (!arg->rcpi_rssi &&
  78             (ieee80211_is_probe_resp(frame->frame_control) ||
  79              ieee80211_is_beacon(frame->frame_control)))
  80                 goto drop;
  81
  82         if (arg->status == HIF_STATUS_MICFAILURE)
  83                 hdr->flag |= RX_FLAG_MMIC_ERROR;
  84         else if (arg->status)
  85                 goto drop;
  86
  87         if (skb->len < sizeof(struct ieee80211_pspoll)) {
  88                 dev_warn(wvif->wdev->dev, "malformed SDU received\n");
  89                 goto drop;
  90         }
  91
  92         hdr->band = NL80211_BAND_2GHZ;
  93         hdr->freq = ieee80211_channel_to_frequency(arg->channel_number,
  94                                                    hdr->band);
  95
  96         if (arg->rxed_rate >= 14) {
  97                 hdr->encoding = RX_ENC_HT;
  98                 hdr->rate_idx = arg->rxed_rate - 14;
  99         } else if (arg->rxed_rate >= 4) {
 100                 hdr->rate_idx = arg->rxed_rate - 2;
 101         } else {
 102                 hdr->rate_idx = arg->rxed_rate;
 103         }
 104
 105         hdr->signal = arg->rcpi_rssi / 2 - 110;
 106         hdr->antenna = 0;
 107
 108         if (arg->rx_flags.encryp) {
 109                 if (wfx_drop_encrypt_data(wvif->wdev, arg, skb))
 110                         goto drop;
 111                 hdr->flag |= RX_FLAG_DECRYPTED | RX_FLAG_IV_STRIPPED;
 112                 if (arg->rx_flags.encryp == HIF_RI_FLAGS_TKIP_ENCRYPTED)
 113                         hdr->flag |= RX_FLAG_MMIC_STRIPPED;
 114         }
 115
 116         /* Filter block ACK negotiation: fully controlled by firmware */
 117         if (ieee80211_is_action(frame->frame_control) &&
 118             arg->rx_flags.match_uc_addr &&
 119             mgmt->u.action.category == WLAN_CATEGORY_BACK)
 120                 goto drop;
 121         if (ieee80211_is_beacon(frame->frame_control) &&
 122             !arg->status && wvif->vif &&
 123             ether_addr_equal(ieee80211_get_SA(frame),
 124                              wvif->vif->bss_conf.bssid)) {
 125                 /* Disable beacon filter once we're associated... */
 126                 if (wvif->disable_beacon_filter &&
 127                     (wvif->vif->bss_conf.assoc ||
 128                      wvif->vif->bss_conf.ibss_joined)) {
 129                         wvif->disable_beacon_filter = false;
 130                         schedule_work(&wvif->update_filtering_work);
 131                 }
 132         }
 133         ieee80211_rx_irqsafe(wvif->wdev->hw, skb);
 134
 135         return;
 136
 137 drop:
 138         dev_kfree_skb(skb);
 139 }