diff options
Diffstat (limited to 'package/libertas/src/rx.c')
| -rw-r--r-- | package/libertas/src/rx.c | 400 |
1 files changed, 400 insertions, 0 deletions
diff --git a/package/libertas/src/rx.c b/package/libertas/src/rx.c new file mode 100644 index 0000000000..6332fd451a --- /dev/null +++ b/package/libertas/src/rx.c @@ -0,0 +1,400 @@ +/** + * 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(struct lbs_private *priv, + struct sk_buff *skb); + +/** + * @brief This function computes the avgSNR . + * + * @param priv A pointer to struct lbs_private structure + * @return avgSNR + */ +static u8 lbs_getavgsnr(struct lbs_private *priv) +{ + u8 i; + u16 temp = 0; + if (priv->numSNRNF == 0) + return 0; + for (i = 0; i < priv->numSNRNF; i++) + temp += priv->rawSNR[i]; + return (u8) (temp / priv->numSNRNF); + +} + +/** + * @brief This function computes the AvgNF + * + * @param priv A pointer to struct lbs_private structure + * @return AvgNF + */ +static u8 lbs_getavgnf(struct lbs_private *priv) +{ + u8 i; + u16 temp = 0; + if (priv->numSNRNF == 0) + return 0; + for (i = 0; i < priv->numSNRNF; i++) + temp += priv->rawNF[i]; + return (u8) (temp / priv->numSNRNF); + +} + +/** + * @brief This function save the raw SNR/NF to our internel buffer + * + * @param priv A pointer to struct lbs_private structure + * @param prxpd A pointer to rxpd structure of received packet + * @return n/a + */ +static void lbs_save_rawSNRNF(struct lbs_private *priv, struct rxpd *p_rx_pd) +{ + if (priv->numSNRNF < DEFAULT_DATA_AVG_FACTOR) + priv->numSNRNF++; + priv->rawSNR[priv->nextSNRNF] = p_rx_pd->snr; + priv->rawNF[priv->nextSNRNF] = p_rx_pd->nf; + priv->nextSNRNF++; + if (priv->nextSNRNF >= DEFAULT_DATA_AVG_FACTOR) + priv->nextSNRNF = 0; + return; +} + +/** + * @brief This function computes the RSSI in received packet. + * + * @param priv A pointer to struct lbs_private structure + * @param prxpd A pointer to rxpd structure of received packet + * @return n/a + */ +static void lbs_compute_rssi(struct lbs_private *priv, struct rxpd *p_rx_pd) +{ + + lbs_deb_enter(LBS_DEB_RX); + + lbs_deb_rx("rxpd: SNR %d, NF %d\n", p_rx_pd->snr, p_rx_pd->nf); + lbs_deb_rx("before computing SNR: SNR-avg = %d, NF-avg = %d\n", + priv->SNR[TYPE_RXPD][TYPE_AVG] / AVG_SCALE, + priv->NF[TYPE_RXPD][TYPE_AVG] / AVG_SCALE); + + priv->SNR[TYPE_RXPD][TYPE_NOAVG] = p_rx_pd->snr; + priv->NF[TYPE_RXPD][TYPE_NOAVG] = p_rx_pd->nf; + lbs_save_rawSNRNF(priv, p_rx_pd); + + priv->SNR[TYPE_RXPD][TYPE_AVG] = lbs_getavgsnr(priv) * AVG_SCALE; + priv->NF[TYPE_RXPD][TYPE_AVG] = lbs_getavgnf(priv) * AVG_SCALE; + lbs_deb_rx("after computing SNR: SNR-avg = %d, NF-avg = %d\n", + priv->SNR[TYPE_RXPD][TYPE_AVG] / AVG_SCALE, + priv->NF[TYPE_RXPD][TYPE_AVG] / AVG_SCALE); + + priv->RSSI[TYPE_RXPD][TYPE_NOAVG] = + CAL_RSSI(priv->SNR[TYPE_RXPD][TYPE_NOAVG], + priv->NF[TYPE_RXPD][TYPE_NOAVG]); + + priv->RSSI[TYPE_RXPD][TYPE_AVG] = + CAL_RSSI(priv->SNR[TYPE_RXPD][TYPE_AVG] / AVG_SCALE, + priv->NF[TYPE_RXPD][TYPE_AVG] / AVG_SCALE); + + lbs_deb_leave(LBS_DEB_RX); +} + +/** + * @brief This function processes received packet and forwards it + * to kernel/upper layer + * + * @param priv A pointer to struct lbs_private + * @param skb A pointer to skb which includes the received packet + * @return 0 or -1 + */ +int lbs_process_rxed_packet(struct lbs_private *priv, struct sk_buff *skb) +{ + int ret = 0; + struct net_device *dev = priv->dev; + 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 }; + + lbs_deb_enter(LBS_DEB_RX); + + skb->ip_summed = CHECKSUM_NONE; + + if (priv->monitormode != LBS_MONITOR_OFF) + return process_rxed_802_11_packet(priv, skb); + + p_rx_pkt = (struct rxpackethdr *) skb->data; + p_rx_pd = &p_rx_pkt->rx_pd; + if (priv->mesh_dev && (p_rx_pd->rx_control & RxPD_MESH_FRAME)) + dev = priv->mesh_dev; + + lbs_deb_hex(LBS_DEB_RX, "RX Data: Before chop rxpd", skb->data, + min_t(unsigned int, skb->len, 100)); + + if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) { + lbs_deb_rx("rx err: 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 & cpu_to_le16(MRVDRV_RXPD_STATUS_OK))) { + lbs_deb_rx("rx err: frame received with bad status\n"); + lbs_pr_alert("rxpd not ok\n"); + priv->stats.rx_errors++; + ret = 0; + goto done; + } + + lbs_deb_rx("rx data: skb->len-sizeof(RxPd) = %d-%zd = %zd\n", + skb->len, sizeof(struct rxpd), skb->len - sizeof(struct rxpd)); + + lbs_deb_hex(LBS_DEB_RX, "RX Data: Dest", p_rx_pkt->eth803_hdr.dest_addr, + sizeof(p_rx_pkt->eth803_hdr.dest_addr)); + lbs_deb_hex(LBS_DEB_RX, "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_deb_hex(LBS_DEB_RX, "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 (priv->auto_rate) + priv->cur_rate = lbs_fw_index_to_data_rate(p_rx_pd->rx_rate); + + lbs_compute_rssi(priv, p_rx_pd); + + lbs_deb_rx("rx data: size of actual packet %d\n", skb->len); + priv->stats.rx_bytes += skb->len; + priv->stats.rx_packets++; + + skb->protocol = eth_type_trans(skb, dev); + netif_rx(skb); + + ret = 0; +done: + lbs_deb_leave_args(LBS_DEB_RX, "ret %d", ret); + return ret; +} +EXPORT_SYMBOL_GPL(lbs_process_rxed_packet); + +/** + * @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: reserved */ + case 5: /* 6 Mbps */ + return 12; + case 6: /* 9 Mbps */ + return 18; + case 7: /* 12 Mbps */ + return 24; + case 8: /* 18 Mbps */ + return 36; + case 9: /* 24 Mbps */ + return 48; + case 10: /* 36 Mbps */ + return 72; + case 11: /* 48 Mbps */ + return 96; + case 12: /* 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 struct lbs_private + * @param skb A pointer to skb which includes the received packet + * @return 0 or -1 + */ +static int process_rxed_802_11_packet(struct lbs_private *priv, + struct sk_buff *skb) +{ + int ret = 0; + + struct rx80211packethdr *p_rx_pkt; + struct rxpd *prxpd; + struct rx_radiotap_hdr radiotap_hdr; + struct rx_radiotap_hdr *pradiotap_hdr; + + lbs_deb_enter(LBS_DEB_RX); + + p_rx_pkt = (struct rx80211packethdr *) skb->data; + prxpd = &p_rx_pkt->rx_pd; + + // lbs_deb_hex(LBS_DEB_RX, "RX Data: Before chop rxpd", skb->data, min(skb->len, 100)); + + if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) { + lbs_deb_rx("rx err: frame received with bad length\n"); + priv->stats.rx_length_errors++; + ret = -EINVAL; + kfree(skb); + goto done; + } + + /* + * Check rxpd status and update 802.3 stat, + */ + if (!(prxpd->status & cpu_to_le16(MRVDRV_RXPD_STATUS_OK))) { + //lbs_deb_rx("rx err: frame received with bad status\n"); + priv->stats.rx_errors++; + } + + lbs_deb_rx("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 */ + + /* 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 = cpu_to_le16 (sizeof(struct rx_radiotap_hdr)); + radiotap_hdr.hdr.it_present = cpu_to_le32 (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 & cpu_to_le16(MRVDRV_RXPD_STATUS_OK))) + radiotap_hdr.rx_flags |= IEEE80211_RADIOTAP_F_RX_BADFCS; + //memset(radiotap_hdr.pad, 0x11, IEEE80211_RADIOTAP_HDRLEN - 18); + + /* 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__); + ret = -ENOMEM; + kfree_skb(skb); + goto done; + } + + pradiotap_hdr = (void *)skb_push(skb, sizeof(struct rx_radiotap_hdr)); + memcpy(pradiotap_hdr, &radiotap_hdr, sizeof(struct rx_radiotap_hdr)); + + /* Take the data rate from the rxpd structure + * only if the rate is auto + */ + if (priv->auto_rate) + priv->cur_rate = lbs_fw_index_to_data_rate(prxpd->rx_rate); + + lbs_compute_rssi(priv, prxpd); + + lbs_deb_rx("rx data: size of actual packet %d\n", skb->len); + priv->stats.rx_bytes += skb->len; + priv->stats.rx_packets++; + + skb->protocol = eth_type_trans(skb, priv->rtap_net_dev); + netif_rx(skb); + + ret = 0; + +done: + lbs_deb_leave_args(LBS_DEB_RX, "ret %d", ret); + return ret; +} |