/**
* This file contains the handling of RX in wlan driver.
*/
#include <linux/etherdevice.h>
#include <linux/types.h>
#include "hostcmd.h"
#include "radiotap.h"
#include "decl.h"
#include "dev.h"
#include "wext.h"
struct eth803hdr {
u8 dest_addr[6];
u8 src_addr[6];
u16 h803_len;
} __attribute__ ((packed));
struct rfc1042hdr {
u8 llc_dsap;
u8 llc_ssap;
u8 llc_ctrl;
u8 snap_oui[3];
u16 snap_type;
} __attribute__ ((packed));
struct rxpackethdr {
struct rxpd rx_pd;
struct eth803hdr eth803_hdr;
struct rfc1042hdr rfc1042_hdr;
} __attribute__ ((packed));
struct rx80211packethdr {
struct rxpd rx_pd;
void *eth80211_hdr;
} __attribute__ ((packed));
static int process_rxed_802_11_packet(wlan_private * priv, struct sk_buff *skb);
/**
* @brief This function computes the avgSNR .
*
* @param priv A pointer to wlan_private structure
* @return avgSNR
*/
static u8 wlan_getavgsnr(wlan_private * priv)
{
u8 i;
u16 temp = 0;
wlan_adapter *adapter = priv->adapter;
if (adapter->numSNRNF == 0)
return 0;
for (i = 0; i < adapter->numSNRNF; i++)
temp += adapter->rawSNR[i];
return (u8) (temp / adapter->numSNRNF);
}
/**
* @brief This function computes the AvgNF
*
* @param priv A pointer to wlan_private structure
* @return AvgNF
*/
static u8 wlan_getavgnf(wlan_private * priv)
{
u8 i;
u16 temp = 0;
wlan_adapter *adapter = priv->adapter;
if (adapter->numSNRNF == 0)
return 0;
for (i = 0; i < adapter->numSNRNF; i++)
temp += adapter->rawNF[i];
return (u8) (temp / adapter->numSNRNF);
}
/**
* @brief This function save the raw SNR/NF to our internel buffer
*
* @param priv A pointer to wlan_private structure
* @param prxpd A pointer to rxpd structure of received packet
* @return n/a
*/
static void wlan_save_rawSNRNF(wlan_private * priv, struct rxpd *p_rx_pd)
{
wlan_adapter *adapter = priv->adapter;
if (adapter->numSNRNF < adapter->data_avg_factor)
adapter->numSNRNF++;
adapter->rawSNR[adapter->nextSNRNF] = p_rx_pd->snr;
adapter->rawNF[adapter->nextSNRNF] = p_rx_pd->nf;
adapter->nextSNRNF++;
if (adapter->nextSNRNF >= adapter->data_avg_factor)
adapter->nextSNRNF = 0;
return;
}
/**
* @brief This function computes the RSSI in received packet.
*
* @param priv A pointer to wlan_private structure
* @param prxpd A pointer to rxpd structure of received packet
* @return n/a
*/
static void wlan_compute_rssi(wlan_private * priv, struct rxpd *p_rx_pd)
{
wlan_adapter *adapter = priv->adapter;
ENTER();
lbs_pr_debug(1, "rxpd: SNR = %d, NF = %d\n", p_rx_pd->snr, p_rx_pd->nf);
lbs_pr_debug(1, "Before computing SNR: SNR- avg = %d, NF-avg = %d\n",
adapter->SNR[TYPE_RXPD][TYPE_AVG] / AVG_SCALE,
adapter->NF[TYPE_RXPD][TYPE_AVG] / AVG_SCALE);
adapter->SNR[TYPE_RXPD][TYPE_NOAVG] = p_rx_pd->snr;
adapter->NF[TYPE_RXPD][TYPE_NOAVG] = p_rx_pd->nf;
wlan_save_rawSNRNF(priv, p_rx_pd);
adapter->rxpd_rate = p_rx_pd->rx_rate;
adapter->SNR[TYPE_RXPD][TYPE_AVG] = wlan_getavgsnr(priv) * AVG_SCALE;
adapter->NF[TYPE_RXPD][TYPE_AVG] = wlan_getavgnf(priv) * AVG_SCALE;
lbs_pr_debug(1, "After computing SNR: SNR-avg = %d, NF-avg = %d\n",
adapter->SNR[TYPE_RXPD][TYPE_AVG] / AVG_SCALE,
adapter->NF[TYPE_RXPD][TYPE_AVG] / AVG_SCALE);
adapter->RSSI[TYPE_RXPD][TYPE_NOAVG] =
CAL_RSSI(adapter->SNR[TYPE_RXPD][TYPE_NOAVG],
adapter->NF[TYPE_RXPD][TYPE_NOAVG]);
adapter->RSSI[TYPE_RXPD][TYPE_AVG] =
CAL_RSSI(adapter->SNR[TYPE_RXPD][TYPE_AVG] / AVG_SCALE,
adapter->NF[TYPE_RXPD][TYPE_AVG] / AVG_SCALE);
LEAVE();
}
int libertas_upload_rx_packet(wlan_private * priv, struct sk_buff *skb)
{
lbs_pr_debug(1, "skb->data=%p\n", skb->data);
if(IS_MESH_FRAME(skb))
skb->dev = priv->mesh_dev;
else
skb->dev = priv->wlan_dev.netdev;
skb->protocol = eth_type_trans(skb, priv->wlan_dev.netdev);
skb->ip_summed = CHECKSUM_UNNECESSARY;
netif_rx(skb);
return 0;
}
/**
* @brief This function processes received packet and forwards it
* to kernel/upper layer
*
* @param priv A pointer to wlan_private
* @param skb A pointer to skb which includes the received packet
* @return 0 or -1
*/
int libertas_process_rxed_packet(wlan_private * priv, struct sk_buff *skb)
{
wlan_adapter *adapter = priv->adapter;
int ret = 0;
struct rxpackethdr *p_rx_pkt;
struct rxpd *p_rx_pd;
int hdrchop;
struct ethhdr *p_ethhdr;
const u8 rfc1042_eth_hdr[] = { 0xaa, 0xaa, 0x03, 0x00, 0x00, 0x00 };
ENTER();
if (priv->adapter->debugmode & MRVDRV_DEBUG_RX_PATH)
lbs_dbg_hex("RX packet: ", skb->data,
min_t(unsigned int, skb->len, 100));
if (priv->adapter->linkmode == WLAN_LINKMODE_802_11)
return process_rxed_802_11_packet(priv, skb);
p_rx_pkt = (struct rxpackethdr *) skb->data;
p_rx_pd = &p_rx_pkt->rx_pd;
if (p_rx_pd->rx_control & RxPD_MESH_FRAME)
SET_MESH_FRAME(skb);
else
UNSET_MESH_FRAME(skb);
lbs_dbg_hex("RX Data: Before chop rxpd", skb->data,
min_t(unsigned int, skb->len, 100));
if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) {
lbs_pr_debug(1, "RX error: FRAME RECEIVED WITH BAD LENGTH\n");
priv->stats.rx_length_errors++;
ret = 0;
goto done;
}
/*
* Check rxpd status and update 802.3 stat,
*/
if (!(p_rx_pd->status & MRVDRV_RXPD_STATUS_OK)) {
lbs_pr_debug(1, "RX error: frame received with bad status\n");
lbs_pr_alert("rxpd Not OK\n");
priv->stats.rx_errors++;
ret = 0;
goto done;
}
lbs_pr_debug(1, "RX Data: skb->len - sizeof(RxPd) = %d - %zd = %zd\n",
skb->len, sizeof(struct rxpd), skb->len - sizeof(struct rxpd));
lbs_dbg_hex("RX Data: Dest", p_rx_pkt->eth803_hdr.dest_addr,
sizeof(p_rx_pkt->eth803_hdr.dest_addr));
lbs_dbg_hex("RX Data: Src", p_rx_pkt->eth803_hdr.src_addr,
sizeof(p_rx_pkt->eth803_hdr.src_addr));
if (memcmp(&p_rx_pkt->rfc1042_hdr,
rfc1042_eth_hdr, sizeof(rfc1042_eth_hdr)) == 0) {
/*
* Replace the 803 header and rfc1042 header (llc/snap) with an
* EthernetII header, keep the src/dst and snap_type (ethertype)
*
* The firmware only passes up SNAP frames converting
* all RX Data from 802.11 to 802.2/LLC/SNAP frames.
*
* To create the Ethernet II, just move the src, dst address right
* before the snap_type.
*/
p_ethhdr = (struct ethhdr *)
((u8 *) & p_rx_pkt->eth803_hdr
+ sizeof(p_rx_pkt->eth803_hdr) + sizeof(p_rx_pkt->rfc1042_hdr)
- sizeof(p_rx_pkt->eth803_hdr.dest_addr)
- sizeof(p_rx_pkt->eth803_hdr.src_addr)
- sizeof(p_rx_pkt->rfc1042_hdr.snap_type));
memcpy(p_ethhdr->h_source, p_rx_pkt->eth803_hdr.src_addr,
sizeof(p_ethhdr->h_source));
memcpy(p_ethhdr->h_dest, p_rx_pkt->eth803_hdr.dest_addr,
sizeof(p_ethhdr->h_dest));
/* Chop off the rxpd + the excess memory from the 802.2/llc/snap header
* that was removed
*/
hdrchop = (u8 *) p_ethhdr - (u8 *) p_rx_pkt;
} else {
lbs_dbg_hex("RX Data: LLC/SNAP",
(u8 *) & p_rx_pkt->rfc1042_hdr,
sizeof(p_rx_pkt->rfc1042_hdr));
/* Chop off the rxpd */
hdrchop = (u8 *) & p_rx_pkt->eth803_hdr - (u8 *) p_rx_pkt;
}
/* Chop off the leading header bytes so the skb points to the start of
* either the reconstructed EthII frame or the 802.2/llc/snap frame
*/
skb_pull(skb, hdrchop);
/* Take the data rate from the rxpd structure
* only if the rate is auto
*/
if (adapter->is_datarate_auto)
adapter->datarate = libertas_index_to_data_rate(p_rx_pd->rx_rate);
wlan_compute_rssi(priv, p_rx_pd);
lbs_pr_debug(1, "RX Data: size of actual packet = %d\n", skb->len);
if (libertas_upload_rx_packet(priv, skb)) {
lbs_pr_debug(1, "RX error: libertas_upload_rx_packet"
" returns failure\n");
ret = -1;
goto done;
}
priv->stats.rx_bytes += skb->len;
priv->stats.rx_packets++;
ret = 0;
done:
LEAVE();
return ret;
}
/**
* @brief This function converts Tx/Rx rates from the Marvell WLAN format
* (see Table 2 in Section 3.1) to IEEE80211_RADIOTAP_RATE units (500 Kb/s)
*
* @param rate Input rate
* @return Output Rate (0 if invalid)
*/
static u8 convert_mv_rate_to_radiotap(u8 rate)
{
switch (rate) {
case 0: /* 1 Mbps */
return 2;
case 1: /* 2 Mbps */
return 4;
case 2: /* 5.5 Mbps */
return 11;
case 3: /* 11 Mbps */
return 22;
case 4: /* 6 Mbps */
return 12;
case 5: /* 9 Mbps */
return 18;
case 6: /* 12 Mbps */
return 24;
case 7: /* 18 Mbps */
return 36;
case 8: /* 24 Mbps */
return 48;
case 9: /* 36 Mbps */
return 72;
case 10: /* 48 Mbps */
return 96;
case 11: /* 54 Mbps */
return 108;
}
lbs_pr_alert( "Invalid Marvell WLAN rate (%i)\n", rate);
return 0;
}
/**
* @brief This function processes a received 802.11 packet and forwards it
* to kernel/upper layer
*
* @param priv A pointer to wlan_private
* @param skb A pointer to skb which includes the received packet
* @return 0 or -1
*/
static int process_rxed_802_11_packet(wlan_private * priv, struct sk_buff *skb)
{
wlan_adapter *adapter = priv->adapter;
int ret = 0;
struct rx80211packethdr *p_rx_pkt;
struct rxpd *prxpd;
struct rx_radiotap_hdr radiotap_hdr;
struct rx_radiotap_hdr *pradiotap_hdr;
ENTER();
p_rx_pkt = (struct rx80211packethdr *) skb->data;
prxpd = &p_rx_pkt->rx_pd;
// lbs_dbg_hex("RX Data: Before chop rxpd", skb->data, min(skb->len, 100));
if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) {
lbs_pr_debug(1, "RX error: FRAME RECEIVED WITH BAD LENGTH\n");
priv->stats.rx_length_errors++;
ret = 0;
goto done;
}
/*
* Check rxpd status and update 802.3 stat,
*/
if (!(prxpd->status & MRVDRV_RXPD_STATUS_OK)) {
//lbs_pr_debug(1, "RX error: frame received with bad status\n");
priv->stats.rx_errors++;
}
lbs_pr_debug(1, "RX Data: skb->len - sizeof(RxPd) = %d - %zd = %zd\n",
skb->len, sizeof(struct rxpd), skb->len - sizeof(struct rxpd));
/* create the exported radio header */
switch (priv->adapter->radiomode) {
case WLAN_RADIOMODE_NONE:
/* no radio header */
/* chop the rxpd */
skb_pull(skb, sizeof(struct rxpd));
break;
case WLAN_RADIOMODE_RADIOTAP:
/* radiotap header */
radiotap_hdr.hdr.it_version = 0;
/* XXX must check this value for pad */
radiotap_hdr.hdr.it_pad = 0;
radiotap_hdr.hdr.it_len = sizeof(struct rx_radiotap_hdr);
radiotap_hdr.hdr.it_present = RX_RADIOTAP_PRESENT;
/* unknown values */
radiotap_hdr.flags = 0;
radiotap_hdr.chan_freq = 0;
radiotap_hdr.chan_flags = 0;
radiotap_hdr.antenna = 0;
/* known values */
radiotap_hdr.rate = convert_mv_rate_to_radiotap(prxpd->rx_rate);
/* XXX must check no carryout */
radiotap_hdr.antsignal = prxpd->snr + prxpd->nf;
radiotap_hdr.rx_flags = 0;
if (!(prxpd->status & MRVDRV_RXPD_STATUS_OK))
radiotap_hdr.rx_flags |= IEEE80211_RADIOTAP_F_RX_BADFCS;
//memset(radiotap_hdr.pad, 0x11, IEEE80211_RADIOTAP_HDRLEN - 18);
// lbs_dbg_hex1("RX radiomode packet BEF: ", skb->data, min(skb->len, 100));
/* chop the rxpd */
skb_pull(skb, sizeof(struct rxpd));
/* add space for the new radio header */
if ((skb_headroom(skb) < sizeof(struct rx_radiotap_hdr)) &&
pskb_expand_head(skb, sizeof(struct rx_radiotap_hdr), 0,
GFP_ATOMIC)) {
lbs_pr_alert( "%s: couldn't pskb_expand_head\n",
__func__);
}
pradiotap_hdr =
(struct rx_radiotap_hdr *)skb_push(skb,
sizeof(struct
rx_radiotap_hdr));
memcpy(pradiotap_hdr, &radiotap_hdr,
sizeof(struct rx_radiotap_hdr));
//lbs_dbg_hex1("RX radiomode packet AFT: ", skb->data, min(skb->len, 100));
break;
default:
/* unknown header */
lbs_pr_alert( "Unknown radiomode (%i)\n",
priv->adapter->radiomode);
/* don't export any header */
/* chop the rxpd */
skb_pull(skb, sizeof(struct rxpd));
break;
}
/* Take the data rate from the rxpd structure
* only if the rate is auto
*/
if (adapter->is_datarate_auto) {
adapter->datarate = libertas_index_to_data_rate(prxpd->rx_rate);
}
wlan_compute_rssi(priv, prxpd);
lbs_pr_debug(1, "RX Data: size of actual packet = %d\n", skb->len);
if (libertas_upload_rx_packet(priv, skb)) {
lbs_pr_debug(1, "RX error: libertas_upload_rx_packet "
"returns failure\n");
ret = -1;
goto done;
}
priv->stats.rx_bytes += skb->len;
priv->stats.rx_packets++;
ret = 0;
done:
LEAVE();
skb->protocol = __constant_htons(0x0019); /* ETH_P_80211_RAW */
return (ret);
}
