packet_anno.h

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#ifndef PACKET_ANNO_H
#define PACKET_ANNO_H
/*
 * Click packet annotations.
 */


#define EXTRA_HEADER_CB_OFFSET 16
#define CB_SIZE 48
#define WIFI_EXTRA_MAGIC  0x7492001
enum {
  WIFI_EXTRA_TX                    = (1<<0), // 1
  WIFI_EXTRA_TX_FAIL               = (1<<1), // 2
  WIFI_EXTRA_TX_USED_ALT_RATE      = (1<<2), // 4
  WIFI_EXTRA_RX_ERR                = (1<<3), // 8
  WIFI_EXTRA_RX_MORE               = (1<<4), // 16
  WIFI_EXTRA_NO_SEQ                = (1<<5),
  WIFI_EXTRA_NO_TXF                = (1<<6),
  WIFI_EXTRA_DO_RTS_CTS            = (1<<7),
  WIFI_EXTRA_DO_CTS                = (1<<8),
};



struct click_wifi_extra {
  u_int32_t magic;
  u_int32_t flags;

  u_int8_t rssi;
  u_int8_t silence;
  u_int8_t power;
  u_int8_t pad;

  u_int8_t rate;
  u_int8_t rate1;
  u_int8_t rate2;
  u_int8_t rate3;

  u_int8_t max_retries;
  u_int8_t max_retries1;
  u_int8_t max_retries2;
  u_int8_t max_retries3;

  u_int8_t virt_col;
  u_int8_t retries;
  u_int16_t len;
};


typedef struct {
  u_int32_t did;
  u_int16_t status;
  u_int16_t len;
  u_int32_t data;
} p80211item_uint32_t;

typedef struct {
  u_int32_t msgcode;
  u_int32_t msglen;
#define WLAN_DEVNAMELEN_MAX 16
  u_int8_t devname[WLAN_DEVNAMELEN_MAX];
  p80211item_uint32_t hosttime;
  p80211item_uint32_t mactime;
  p80211item_uint32_t channel;
  p80211item_uint32_t rssi;
  p80211item_uint32_t sq;
  p80211item_uint32_t signal;
  p80211item_uint32_t noise;
  p80211item_uint32_t rate;
  p80211item_uint32_t istx;
  p80211item_uint32_t frmlen;
} wlan_ng_prism2_header;


#define LWNG_CAP_DID_BASE   (4 | (1 << 6)) /* section 4, group 1 */
#define LWNG_CAPHDR_VERSION 0x80211001


/* ARPHRD_IEEE80211_PRISM uses a bloated version of Prism2 RX frame header
 * (from linux-wlan-ng) */

/*                                                                                  
 * For packet capture, define the same physical layer packet header                 
 * structure as used in the wlan-ng driver                                          
 */
enum {
  DIDmsg_lnxind_wlansniffrm               = 0x00000044,
  DIDmsg_lnxind_wlansniffrm_hosttime      = 0x00010044,
  DIDmsg_lnxind_wlansniffrm_mactime       = 0x00020044,
  DIDmsg_lnxind_wlansniffrm_channel       = 0x00030044,
  DIDmsg_lnxind_wlansniffrm_rssi          = 0x00040044,
  DIDmsg_lnxind_wlansniffrm_sq            = 0x00050044,
  DIDmsg_lnxind_wlansniffrm_signal        = 0x00060044,
  DIDmsg_lnxind_wlansniffrm_noise         = 0x00070044,
  DIDmsg_lnxind_wlansniffrm_rate          = 0x00080044,
  DIDmsg_lnxind_wlansniffrm_istx          = 0x00090044,
  DIDmsg_lnxind_wlansniffrm_frmlen        = 0x000A0044
};
enum {
        P80211ENUM_msgitem_status_no_value      = 0x00
};
enum {
        P80211ENUM_truth_false                  = 0x00
};



static inline struct sk_buff * 
push_wifi_extra_header(struct sk_buff *skb) {
  struct click_wifi_extra *ceh;

  skb = skb_unshare(skb, GFP_ATOMIC);
  if (!skb) {
    return NULL;
  }
  if (skb_headroom(skb) < sizeof(struct click_wifi_extra) && 
      pskb_expand_head(skb, sizeof(struct click_wifi_extra), 0, GFP_ATOMIC)) {
    printk (KERN_WARNING "couldn't pskb_expand_head\n");
    dev_kfree_skb_any(skb);
    return NULL;
  }
  ceh = (struct click_wifi_extra *) skb_push(skb, sizeof(struct click_wifi_extra));

  memcpy(ceh, skb->cb + EXTRA_HEADER_CB_OFFSET, sizeof(struct click_wifi_extra));

  skb->mac.raw = skb->data;
  skb->ip_summed = CHECKSUM_NONE;
  skb->pkt_type = PACKET_OTHERHOST;
  skb->protocol = __constant_htons(0x0019);  /* ETH_P_80211_RAW */
  return skb;
}


static inline void 
pull_wifi_extra_header(struct sk_buff *skb) {
  struct click_wifi_extra *ceh;

  ceh = (struct click_wifi_extra *) skb->data;

  if (ceh->magic != WIFI_EXTRA_MAGIC) {
    memset(skb->cb, 0x00, CB_SIZE);
  } else {
    memcpy(skb->cb + EXTRA_HEADER_CB_OFFSET, ceh, sizeof(struct click_wifi_extra));
    skb_pull(skb, sizeof(struct click_wifi_extra));
  }
  ceh = (struct click_wifi_extra *) (skb->cb + EXTRA_HEADER_CB_OFFSET);
  ceh->magic = WIFI_EXTRA_MAGIC;
}

static void
pull_prism2_header(struct sk_buff *skb) 
{
  wlan_ng_prism2_header *ph = NULL;
  ph = (wlan_ng_prism2_header *) skb->data;
  if (ph->msgcode == DIDmsg_lnxind_wlansniffrm) {
    if (ph->rate.did == DIDmsg_lnxind_wlansniffrm_rate) {
      struct click_wifi_extra *ceh = (struct click_wifi_extra *) (skb->cb + EXTRA_HEADER_CB_OFFSET);
      if (ceh->magic != WIFI_EXTRA_MAGIC) {
        memset(ceh, 0x0, sizeof(struct click_wifi_extra));
        ceh->magic = WIFI_EXTRA_MAGIC;
        ceh->rate = ph->rate.data;
      } 
    }
    skb_pull(skb, sizeof(wlan_ng_prism2_header));
  }

}

/*
 * Add a prism2 header to a received frame and
 * dispatch it to capture tools like kismet.
 */
static void
push_prism2_header(struct net_device *dev, struct sk_buff *skb, 
                   int len, int rssi, int rate, 
                   int tx,
                   u_int32_t tsf)
{
  wlan_ng_prism2_header *ph;


  if (skb_headroom(skb) < sizeof(wlan_ng_prism2_header) && 
      pskb_expand_head(skb, sizeof(wlan_ng_prism2_header), 0, GFP_ATOMIC)) {
    return;
  }
  ph = (wlan_ng_prism2_header *) skb_push(skb, sizeof(wlan_ng_prism2_header));

        if (!ph) {
          printk (KERN_WARNING "%s: ph was null!\n",
                                dev->name);
                  return;
        }

        memset(ph, 0, sizeof(wlan_ng_prism2_header));
        ph->msgcode = DIDmsg_lnxind_wlansniffrm;
        ph->msglen = sizeof(wlan_ng_prism2_header);
        strcpy(ph->devname, dev->name);

        ph->hosttime.did = DIDmsg_lnxind_wlansniffrm_hosttime;
        ph->hosttime.status = 0;
        ph->hosttime.len = 4;
        ph->hosttime.data = jiffies;

        /* Pass up tsf clock in mactime */
        ph->mactime.did = DIDmsg_lnxind_wlansniffrm_mactime;
        ph->mactime.status = 0;
        ph->mactime.len = 4;
        ph->mactime.data = tsf;

        ph->istx.did = DIDmsg_lnxind_wlansniffrm_istx;
        ph->istx.status = 0;
        ph->istx.len = 4;
        ph->istx.data = tx;

        ph->frmlen.did = DIDmsg_lnxind_wlansniffrm_frmlen;
        ph->frmlen.status = 0;
        ph->frmlen.len = 4;
        ph->frmlen.data = len;

        ph->channel.did = DIDmsg_lnxind_wlansniffrm_channel;
        ph->channel.status = 0;
        ph->channel.len = 4;
        ph->channel.data = 0;

        ph->rssi.did = DIDmsg_lnxind_wlansniffrm_rssi;
        ph->rssi.status = P80211ENUM_msgitem_status_no_value;
        ph->rssi.len = 4;
        ph->rssi.data = rssi;

        ph->signal.did = DIDmsg_lnxind_wlansniffrm_signal;
        ph->signal.status = 0;
        ph->signal.len = 4;
        ph->signal.data = rssi;

        ph->rate.did = DIDmsg_lnxind_wlansniffrm_rate;
        ph->rate.status = 0;
        ph->rate.len = 4;
        ph->rate.data = rate;

        skb->dev = dev;
        skb->mac.raw = skb->data;
        skb->ip_summed = CHECKSUM_NONE;
        skb->pkt_type = PACKET_OTHERHOST;
        skb->protocol = __constant_htons(0x0019);  /* ETH_P_80211_RAW */


        return;
}






#endif /* PACKET_ANNO_H */

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