iwlwifi: proper monitor support

This patch changes the iwlwifi driver to properly support
monitor interfaces after the filter flags change.

The patch is originally created by Johannes Berg for iwl4965. I fixed some
of the comments and created a similar patch for iwl3945.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 110 insertions, 10 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-4965.c b/drivers/net/wireless/iwlwifi/iwl-4965.c
index f65fd6e5fecc..74999af37914 100644
--- a/drivers/net/wireless/iwlwifi/iwl-4965.c
+++ b/drivers/net/wireless/iwlwifi/iwl-4965.c
@@ -36,6 +36,7 @@
 #include <linux/wireless.h>
 #include <net/mac80211.h>
 #include <linux/etherdevice.h>
+#include <asm/unaligned.h>
 
 #include "iwl-4965.h"
 #include "iwl-helpers.h"
@@ -3588,6 +3589,111 @@ void iwl4965_hw_rx_statistics(struct iwl4965_priv *priv, struct iwl4965_rx_mem_b
                 queue_work(priv->workqueue, &priv->txpower_work);
 }
 
+static void iwl4965_add_radiotap(struct iwl4965_priv *priv,
+                                 struct sk_buff *skb,
+                                 struct iwl4965_rx_phy_res *rx_start,
+                                 struct ieee80211_rx_status *stats,
+                                 u32 ampdu_status)
+{
+        s8 signal = stats->ssi;
+        s8 noise = 0;
+        int rate = stats->rate;
+        u64 tsf = stats->mactime;
+        __le16 phy_flags_hw = rx_start->phy_flags;
+        struct iwl4965_rt_rx_hdr {
+                struct ieee80211_radiotap_header rt_hdr;
+                __le64 rt_tsf;          /* TSF */
+                u8 rt_flags;            /* radiotap packet flags */
+                u8 rt_rate;             /* rate in 500kb/s */
+                __le16 rt_channelMHz;   /* channel in MHz */
+                __le16 rt_chbitmask;    /* channel bitfield */
+                s8 rt_dbmsignal;        /* signal in dBm, kluged to signed */
+                s8 rt_dbmnoise;
+                u8 rt_antenna;          /* antenna number */
+        } __attribute__ ((packed)) *iwl4965_rt;
+
+        /* TODO: We won't have enough headroom for HT frames. Fix it later. */
+        if (skb_headroom(skb) < sizeof(*iwl4965_rt)) {
+                if (net_ratelimit())
+                        printk(KERN_ERR "not enough headroom [%d] for "
+                               "radiotap head [%d]\n",
+                               skb_headroom(skb), sizeof(*iwl4965_rt));
+                return;
+        }
+
+        /* put radiotap header in front of 802.11 header and data */
+        iwl4965_rt = (void *)skb_push(skb, sizeof(*iwl4965_rt));
+
+        /* initialise radiotap header */
+        iwl4965_rt->rt_hdr.it_version = PKTHDR_RADIOTAP_VERSION;
+        iwl4965_rt->rt_hdr.it_pad = 0;
+
+        /* total header + data */
+        put_unaligned(cpu_to_le16(sizeof(*iwl4965_rt)),
+                      &iwl4965_rt->rt_hdr.it_len);
+
+        /* Indicate all the fields we add to the radiotap header */
+        put_unaligned(cpu_to_le32((1 << IEEE80211_RADIOTAP_TSFT) |
+                                  (1 << IEEE80211_RADIOTAP_FLAGS) |
+                                  (1 << IEEE80211_RADIOTAP_RATE) |
+                                  (1 << IEEE80211_RADIOTAP_CHANNEL) |
+                                  (1 << IEEE80211_RADIOTAP_DBM_ANTSIGNAL) |
+                                  (1 << IEEE80211_RADIOTAP_DBM_ANTNOISE) |
+                                  (1 << IEEE80211_RADIOTAP_ANTENNA)),
+                      &iwl4965_rt->rt_hdr.it_present);
+
+        /* Zero the flags, we'll add to them as we go */
+        iwl4965_rt->rt_flags = 0;
+
+        put_unaligned(cpu_to_le64(tsf), &iwl4965_rt->rt_tsf);
+
+        iwl4965_rt->rt_dbmsignal = signal;
+        iwl4965_rt->rt_dbmnoise = noise;
+
+        /* Convert the channel frequency and set the flags */
+        put_unaligned(cpu_to_le16(stats->freq), &iwl4965_rt->rt_channelMHz);
+        if (!(phy_flags_hw & RX_RES_PHY_FLAGS_BAND_24_MSK))
+                put_unaligned(cpu_to_le16(IEEE80211_CHAN_OFDM |
+                                          IEEE80211_CHAN_5GHZ),
+                              &iwl4965_rt->rt_chbitmask);
+        else if (phy_flags_hw & RX_RES_PHY_FLAGS_MOD_CCK_MSK)
+                put_unaligned(cpu_to_le16(IEEE80211_CHAN_CCK |
+                                          IEEE80211_CHAN_2GHZ),
+                              &iwl4965_rt->rt_chbitmask);
+        else    /* 802.11g */
+                put_unaligned(cpu_to_le16(IEEE80211_CHAN_OFDM |
+                                          IEEE80211_CHAN_2GHZ),
+                              &iwl4965_rt->rt_chbitmask);
+
+        rate = iwl4965_rate_index_from_plcp(rate);
+        if (rate == -1)
+                iwl4965_rt->rt_rate = 0;
+        else
+                iwl4965_rt->rt_rate = iwl4965_rates[rate].ieee;
+
+        /*
+         * "antenna number"
+         *
+         * It seems that the antenna field in the phy flags value
+         * is actually a bitfield. This is undefined by radiotap,
+         * it wants an actual antenna number but I always get "7"
+         * for most legacy frames I receive indicating that the
+         * same frame was received on all three RX chains.
+         *
+         * I think this field should be removed in favour of a
+         * new 802.11n radiotap field "RX chains" that is defined
+         * as a bitmask.
+         */
+        iwl4965_rt->rt_antenna =
+                le16_to_cpu(phy_flags_hw & RX_RES_PHY_FLAGS_ANTENNA_MSK) >> 4;
+
+        /* set the preamble flag if appropriate */
+        if (phy_flags_hw & RX_RES_PHY_FLAGS_SHORT_PREAMBLE_MSK)
+                iwl4965_rt->rt_flags |= IEEE80211_RADIOTAP_F_SHORTPRE;
+
+        stats->flag |= RX_FLAG_RADIOTAP;
+}
+
 static void iwl4965_handle_data_packet(struct iwl4965_priv *priv, int is_data,
                                        int include_phy,
                                        struct iwl4965_rx_mem_buffer *rxb,
@@ -3630,8 +3736,7 @@ static void iwl4965_handle_data_packet(struct iwl4965_priv *priv, int is_data,
                 rx_end = (__le32 *) (((u8 *) hdr) + len);
         }
         if (len > priv->hw_setting.max_pkt_size || len < 16) {
-                IWL_WARNING("byte count out of range [16,4K]"
-                               " : %d\n", len);
+                IWL_WARNING("byte count out of range [16,4K] : %d\n", len);
                 return;
         }
 
@@ -3649,20 +3754,15 @@ static void iwl4965_handle_data_packet(struct iwl4965_priv *priv, int is_data,
                 return;
         }
 
-        if (priv->iw_mode == IEEE80211_IF_TYPE_MNTR) {
-                if (iwl4965_param_hwcrypto)
-                        iwl4965_set_decrypted_flag(priv, rxb->skb,
-                                               ampdu_status, stats);
-                iwl4965_handle_data_packet_monitor(priv, rxb, hdr, len, stats, 0);
-                return;
-        }
-
         stats->flag = 0;
         hdr = (struct ieee80211_hdr *)rxb->skb->data;
 
         if (iwl4965_param_hwcrypto)
                 iwl4965_set_decrypted_flag(priv, rxb->skb, ampdu_status, stats);
 
+        if (priv->add_radiotap)
+                iwl4965_add_radiotap(priv, rxb->skb, rx_start, stats, ampdu_status);
+
         ieee80211_rx_irqsafe(priv->hw, rxb->skb, stats);
         priv->alloc_rxb_skb--;
         rxb->skb = NULL;