marvell/libertas/rx.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * This file contains the handling of RX in wlan driver.
0004  */
0005
0006 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
0007
0008 #include <linux/etherdevice.h>
0009 #include <linux/hardirq.h>
0010 #include <linux/slab.h>
0011 #include <linux/types.h>
0012 #include <linux/export.h>
0013 #include <net/cfg80211.h>
0014
0015 #include "defs.h"
0016 #include "host.h"
0017 #include "radiotap.h"
0018 #include "decl.h"
0019 #include "dev.h"
0020 #include "mesh.h"
0021
0022 struct eth803hdr {
0023     u8 dest_addr[6];
0024     u8 src_addr[6];
0025     u16 h803_len;
0026 } __packed;
0027
0028 struct rfc1042hdr {
0029     u8 llc_dsap;
0030     u8 llc_ssap;
0031     u8 llc_ctrl;
0032     u8 snap_oui[3];
0033     u16 snap_type;
0034 } __packed;
0035
0036 struct rxpackethdr {
0037     struct eth803hdr eth803_hdr;
0038     struct rfc1042hdr rfc1042_hdr;
0039 } __packed;
0040
0041 struct rx80211packethdr {
0042     struct rxpd rx_pd;
0043     void *eth80211_hdr;
0044 } __packed;
0045
0046 static int process_rxed_802_11_packet(struct lbs_private *priv,
0047     struct sk_buff *skb);
0048
0049 /**
0050  * lbs_process_rxed_packet - processes received packet and forwards it
0051  * to kernel/upper layer
0052  *
0053  * @priv:   A pointer to &struct lbs_private
0054  * @skb:    A pointer to skb which includes the received packet
0055  * returns: 0 or -1
0056  */
0057 int lbs_process_rxed_packet(struct lbs_private *priv, struct sk_buff *skb)
0058 {
0059     int ret = 0;
0060     struct net_device *dev = priv->dev;
0061     struct rxpackethdr *p_rx_pkt;
0062     struct rxpd *p_rx_pd;
0063     int hdrchop;
0064     struct ethhdr *p_ethhdr;
0065
0066     BUG_ON(!skb);
0067
0068     skb->ip_summed = CHECKSUM_NONE;
0069
0070     if (priv->wdev->iftype == NL80211_IFTYPE_MONITOR) {
0071         ret = process_rxed_802_11_packet(priv, skb);
0072         goto done;
0073     }
0074
0075     p_rx_pd = (struct rxpd *) skb->data;
0076     p_rx_pkt = (struct rxpackethdr *) ((u8 *)p_rx_pd +
0077         le32_to_cpu(p_rx_pd->pkt_ptr));
0078
0079     dev = lbs_mesh_set_dev(priv, dev, p_rx_pd);
0080
0081     lbs_deb_hex(LBS_DEB_RX, "RX Data: Before chop rxpd", skb->data,
0082          min_t(unsigned int, skb->len, 100));
0083
0084     if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) {
0085         lbs_deb_rx("rx err: frame received with bad length\n");
0086         dev->stats.rx_length_errors++;
0087         ret = -EINVAL;
0088         dev_kfree_skb(skb);
0089         goto done;
0090     }
0091
0092     lbs_deb_rx("rx data: skb->len - pkt_ptr = %d-%zd = %zd\n",
0093         skb->len, (size_t)le32_to_cpu(p_rx_pd->pkt_ptr),
0094         skb->len - (size_t)le32_to_cpu(p_rx_pd->pkt_ptr));
0095
0096     lbs_deb_hex(LBS_DEB_RX, "RX Data: Dest", p_rx_pkt->eth803_hdr.dest_addr,
0097         sizeof(p_rx_pkt->eth803_hdr.dest_addr));
0098     lbs_deb_hex(LBS_DEB_RX, "RX Data: Src", p_rx_pkt->eth803_hdr.src_addr,
0099         sizeof(p_rx_pkt->eth803_hdr.src_addr));
0100
0101     if (memcmp(&p_rx_pkt->rfc1042_hdr,
0102            rfc1042_header, sizeof(rfc1042_header)) == 0) {
0103         /*
0104          *  Replace the 803 header and rfc1042 header (llc/snap) with an
0105          *    EthernetII header, keep the src/dst and snap_type (ethertype)
0106          *
0107          *  The firmware only passes up SNAP frames converting
0108          *    all RX Data from 802.11 to 802.2/LLC/SNAP frames.
0109          *
0110          *  To create the Ethernet II, just move the src, dst address right
0111          *    before the snap_type.
0112          */
0113         p_ethhdr = (struct ethhdr *)
0114             ((u8 *) &p_rx_pkt->eth803_hdr
0115              + sizeof(p_rx_pkt->eth803_hdr) + sizeof(p_rx_pkt->rfc1042_hdr)
0116              - sizeof(p_rx_pkt->eth803_hdr.dest_addr)
0117              - sizeof(p_rx_pkt->eth803_hdr.src_addr)
0118              - sizeof(p_rx_pkt->rfc1042_hdr.snap_type));
0119
0120         memcpy(p_ethhdr->h_source, p_rx_pkt->eth803_hdr.src_addr,
0121                sizeof(p_ethhdr->h_source));
0122         memcpy(p_ethhdr->h_dest, p_rx_pkt->eth803_hdr.dest_addr,
0123                sizeof(p_ethhdr->h_dest));
0124
0125         /* Chop off the rxpd + the excess memory from the 802.2/llc/snap header
0126          *   that was removed
0127          */
0128         hdrchop = (u8 *)p_ethhdr - (u8 *)p_rx_pd;
0129     } else {
0130         lbs_deb_hex(LBS_DEB_RX, "RX Data: LLC/SNAP",
0131             (u8 *) &p_rx_pkt->rfc1042_hdr,
0132             sizeof(p_rx_pkt->rfc1042_hdr));
0133
0134         /* Chop off the rxpd */
0135         hdrchop = (u8 *)&p_rx_pkt->eth803_hdr - (u8 *)p_rx_pd;
0136     }
0137
0138     /* Chop off the leading header bytes so the skb points to the start of
0139      *   either the reconstructed EthII frame or the 802.2/llc/snap frame
0140      */
0141     skb_pull(skb, hdrchop);
0142
0143     priv->cur_rate = lbs_fw_index_to_data_rate(p_rx_pd->rx_rate);
0144
0145     lbs_deb_rx("rx data: size of actual packet %d\n", skb->len);
0146     dev->stats.rx_bytes += skb->len;
0147     dev->stats.rx_packets++;
0148
0149     skb->protocol = eth_type_trans(skb, dev);
0150     netif_rx(skb);
0151
0152     ret = 0;
0153 done:
0154     return ret;
0155 }
0156 EXPORT_SYMBOL_GPL(lbs_process_rxed_packet);
0157
0158 /**
0159  * convert_mv_rate_to_radiotap - converts Tx/Rx rates from Marvell WLAN format
0160  * (see Table 2 in Section 3.1) to IEEE80211_RADIOTAP_RATE units (500 Kb/s)
0161  *
0162  * @rate:   Input rate
0163  * returns: Output Rate (0 if invalid)
0164  */
0165 static u8 convert_mv_rate_to_radiotap(u8 rate)
0166 {
0167     switch (rate) {
0168     case 0:     /*   1 Mbps */
0169         return 2;
0170     case 1:     /*   2 Mbps */
0171         return 4;
0172     case 2:     /* 5.5 Mbps */
0173         return 11;
0174     case 3:     /*  11 Mbps */
0175         return 22;
0176     /* case 4: reserved */
0177     case 5:     /*   6 Mbps */
0178         return 12;
0179     case 6:     /*   9 Mbps */
0180         return 18;
0181     case 7:     /*  12 Mbps */
0182         return 24;
0183     case 8:     /*  18 Mbps */
0184         return 36;
0185     case 9:     /*  24 Mbps */
0186         return 48;
0187     case 10:        /*  36 Mbps */
0188         return 72;
0189     case 11:        /*  48 Mbps */
0190         return 96;
0191     case 12:        /*  54 Mbps */
0192         return 108;
0193     }
0194     pr_alert("Invalid Marvell WLAN rate %i\n", rate);
0195     return 0;
0196 }
0197
0198 /**
0199  * process_rxed_802_11_packet - processes a received 802.11 packet and forwards
0200  * it to kernel/upper layer
0201  *
0202  * @priv:   A pointer to &struct lbs_private
0203  * @skb:    A pointer to skb which includes the received packet
0204  * returns: 0 or -1
0205  */
0206 static int process_rxed_802_11_packet(struct lbs_private *priv,
0207     struct sk_buff *skb)
0208 {
0209     int ret = 0;
0210     struct net_device *dev = priv->dev;
0211     struct rx80211packethdr *p_rx_pkt;
0212     struct rxpd *prxpd;
0213     struct rx_radiotap_hdr radiotap_hdr;
0214     struct rx_radiotap_hdr *pradiotap_hdr;
0215
0216     p_rx_pkt = (struct rx80211packethdr *) skb->data;
0217     prxpd = &p_rx_pkt->rx_pd;
0218
0219     /* lbs_deb_hex(LBS_DEB_RX, "RX Data: Before chop rxpd", skb->data, min(skb->len, 100)); */
0220
0221     if (skb->len < (ETH_HLEN + 8 + sizeof(struct rxpd))) {
0222         lbs_deb_rx("rx err: frame received with bad length\n");
0223         dev->stats.rx_length_errors++;
0224         ret = -EINVAL;
0225         kfree_skb(skb);
0226         goto done;
0227     }
0228
0229     lbs_deb_rx("rx data: skb->len-sizeof(RxPd) = %d-%zd = %zd\n",
0230            skb->len, sizeof(struct rxpd), skb->len - sizeof(struct rxpd));
0231
0232     /* create the exported radio header */
0233
0234     /* radiotap header */
0235     memset(&radiotap_hdr, 0, sizeof(radiotap_hdr));
0236     /* XXX must check radiotap_hdr.hdr.it_pad for pad */
0237     radiotap_hdr.hdr.it_len = cpu_to_le16 (sizeof(struct rx_radiotap_hdr));
0238     radiotap_hdr.hdr.it_present = cpu_to_le32 (RX_RADIOTAP_PRESENT);
0239     radiotap_hdr.rate = convert_mv_rate_to_radiotap(prxpd->rx_rate);
0240     /* XXX must check no carryout */
0241     radiotap_hdr.antsignal = prxpd->snr + prxpd->nf;
0242
0243     /* chop the rxpd */
0244     skb_pull(skb, sizeof(struct rxpd));
0245
0246     /* add space for the new radio header */
0247     if ((skb_headroom(skb) < sizeof(struct rx_radiotap_hdr)) &&
0248         pskb_expand_head(skb, sizeof(struct rx_radiotap_hdr), 0, GFP_ATOMIC)) {
0249         netdev_alert(dev, "%s: couldn't pskb_expand_head\n", __func__);
0250         ret = -ENOMEM;
0251         kfree_skb(skb);
0252         goto done;
0253     }
0254
0255     pradiotap_hdr = skb_push(skb, sizeof(struct rx_radiotap_hdr));
0256     memcpy(pradiotap_hdr, &radiotap_hdr, sizeof(struct rx_radiotap_hdr));
0257
0258     priv->cur_rate = lbs_fw_index_to_data_rate(prxpd->rx_rate);
0259
0260     lbs_deb_rx("rx data: size of actual packet %d\n", skb->len);
0261     dev->stats.rx_bytes += skb->len;
0262     dev->stats.rx_packets++;
0263
0264     skb->protocol = eth_type_trans(skb, priv->dev);
0265     netif_rx(skb);
0266
0267     ret = 0;
0268
0269 done:
0270     return ret;
0271 }