[PATCH] orinoco: always use 802.11 header for rx processing

If the frame has ToDS flag set, mark it by setting skb->pkt_type to
PACKET_OTHERHOST, so that applications unaware of promiscous mode won't get
uplink (STA->AP) packets for STA->STA transmissions relayed by the AP.
Thanks to John Denker and David Gibson for finding the problem and the
solution.

Patch from Pavel Roskin

diff --git a/drivers/net/wireless/orinoco.c b/drivers/net/wireless/orinoco.c
index 38fd862..96df288 100644 (file)
--- a/drivers/net/wireless/orinoco.c
+++ b/drivers/net/wireless/orinoco.c
@@ -619,7 +619,9 @@ struct hermes_tx_descriptor_802_11 {
        u16 ethertype;
 } __attribute__ ((packed));
 
+/* Rx frame header except compatibility 802.3 header */
 struct hermes_rx_descriptor {
+       /* Control */
        u16 status;
        u32 time;
        u8 silence;
@@ -627,6 +629,18 @@ struct hermes_rx_descriptor {
        u8 rate;
        u8 rxflow;
        u32 reserved;
+
+       /* 802.11 header */
+       u16 frame_ctl;
+       u16 duration_id;
+       u8 addr1[ETH_ALEN];
+       u8 addr2[ETH_ALEN];
+       u8 addr3[ETH_ALEN];
+       u16 seq_ctl;
+       u8 addr4[ETH_ALEN];
+
+       /* Data length */
+       u16 data_len;
 } __attribute__ ((packed));
 
 /********************************************************************/
@@ -1110,12 +1124,10 @@ static void __orinoco_ev_rx(struct net_device *dev, hermes_t *hw)
        struct net_device_stats *stats = &priv->stats;
        struct iw_statistics *wstats = &priv->wstats;
        struct sk_buff *skb = NULL;
-       u16 rxfid, status;
-       int length, data_len, data_off;
-       char *p;
+       u16 rxfid, status, fc;
+       int length;
        struct hermes_rx_descriptor desc;
-       struct header_struct hdr;
-       struct ethhdr *eh;
+       struct ethhdr *hdr;
        int err;
 
        rxfid = hermes_read_regn(hw, RXFID);
@@ -1140,24 +1152,14 @@ static void __orinoco_ev_rx(struct net_device *dev, hermes_t *hw)
                        stats->rx_crc_errors++;
                        DEBUG(1, "%s: Bad CRC on Rx. Frame dropped.\n", dev->name);
                }
-               stats->rx_errors++;
-               goto drop;
-       }
 
-       /* For now we ignore the 802.11 header completely, assuming
-           that the card's firmware has handled anything vital */
-
-       err = hermes_bap_pread(hw, IRQ_BAP, &hdr, sizeof(hdr),
-                              rxfid, HERMES_802_3_OFFSET);
-       if (err) {
-               printk(KERN_ERR "%s: error %d reading frame header. "
-                      "Frame dropped.\n", dev->name, err);
                stats->rx_errors++;
                goto drop;
        }
 
-       length = ntohs(hdr.len);
-       
+       length = le16_to_cpu(desc.data_len);
+       fc = le16_to_cpu(desc.frame_ctl);
+
        /* Sanity checks */
        if (length < 3) { /* No for even an 802.2 LLC header */
                /* At least on Symbol firmware with PCF we get quite a
@@ -1186,57 +1188,51 @@ static void __orinoco_ev_rx(struct net_device *dev, hermes_t *hw)
                goto drop;
        }
 
-       skb_reserve(skb, 2); /* This way the IP header is aligned */
+       /* We'll prepend the header, so reserve space for it.  The worst
+          case is no decapsulation, when 802.3 header is prepended and
+          nothing is removed.  2 is for aligning the IP header.  */
+       skb_reserve(skb, ETH_HLEN + 2);
+
+       err = hermes_bap_pread(hw, IRQ_BAP, skb_put(skb, length),
+                              ALIGN(length, 2), rxfid,
+                              HERMES_802_2_OFFSET);
+       if (err) {
+               printk(KERN_ERR "%s: error %d reading frame. "
+                      "Frame dropped.\n", dev->name, err);
+               stats->rx_errors++;
+               goto drop;
+       }
 
        /* Handle decapsulation
         * In most cases, the firmware tell us about SNAP frames.
         * For some reason, the SNAP frames sent by LinkSys APs
         * are not properly recognised by most firmwares.
         * So, check ourselves */
-       if (((status & HERMES_RXSTAT_MSGTYPE) == HERMES_RXSTAT_1042) ||
-           ((status & HERMES_RXSTAT_MSGTYPE) == HERMES_RXSTAT_TUNNEL) ||
-           is_ethersnap(&hdr)) {
+       if (length >= ENCAPS_OVERHEAD &&
+           (((status & HERMES_RXSTAT_MSGTYPE) == HERMES_RXSTAT_1042) ||
+            ((status & HERMES_RXSTAT_MSGTYPE) == HERMES_RXSTAT_TUNNEL) ||
+            is_ethersnap(skb->data))) {
                /* These indicate a SNAP within 802.2 LLC within
                   802.11 frame which we'll need to de-encapsulate to
                   the original EthernetII frame. */
-
-               if (length < ENCAPS_OVERHEAD) { /* No room for full LLC+SNAP */
-                       stats->rx_length_errors++;
-                       goto drop;
-               }
-
-               /* Remove SNAP header, reconstruct EthernetII frame */
-               data_len = length - ENCAPS_OVERHEAD;
-               data_off = HERMES_802_3_OFFSET + sizeof(hdr);
-
-               eh = (struct ethhdr *)skb_put(skb, ETH_HLEN);
-
-               memcpy(eh, &hdr, 2 * ETH_ALEN);
-               eh->h_proto = hdr.ethertype;
+               hdr = (struct ethhdr *)skb_push(skb, ETH_HLEN - ENCAPS_OVERHEAD);
        } else {
-               /* All other cases indicate a genuine 802.3 frame.  No
-                  decapsulation needed.  We just throw the whole
-                  thing in, and hope the protocol layer can deal with
-                  it as 802.3 */
-               data_len = length;
-               data_off = HERMES_802_3_OFFSET;
-               /* FIXME: we re-read from the card data we already read here */
-       }
-
-       p = skb_put(skb, data_len);
-       err = hermes_bap_pread(hw, IRQ_BAP, p, ALIGN(data_len, 2),
-                              rxfid, data_off);
-       if (err) {
-               printk(KERN_ERR "%s: error %d reading frame. "
-                      "Frame dropped.\n", dev->name, err);
-               stats->rx_errors++;
-               goto drop;
+               /* 802.3 frame - prepend 802.3 header as is */
+               hdr = (struct ethhdr *)skb_push(skb, ETH_HLEN);
+               hdr->h_proto = htons(length);
        }
+       memcpy(hdr->h_dest, desc.addr1, ETH_ALEN);
+       if (fc & IEEE80211_FCTL_FROMDS)
+               memcpy(hdr->h_source, desc.addr3, ETH_ALEN);
+       else
+               memcpy(hdr->h_source, desc.addr2, ETH_ALEN);
 
        dev->last_rx = jiffies;
        skb->dev = dev;
        skb->protocol = eth_type_trans(skb, dev);
        skb->ip_summed = CHECKSUM_NONE;
+       if (fc & IEEE80211_FCTL_TODS)
+               skb->pkt_type = PACKET_OTHERHOST;
        
        /* Process the wireless stats if needed */
        orinoco_stat_gather(dev, skb, &desc);
@@ -1457,6 +1453,9 @@ static void __orinoco_ev_info(struct net_device *dev, hermes_t *hw)
                u16 newstatus;
                int connected;
 
+               if (priv->iw_mode == IW_MODE_MONITOR)
+                       break;
+
                if (len != sizeof(linkstatus)) {
                        printk(KERN_WARNING "%s: Unexpected size for linkstatus frame (%d bytes)\n",
                               dev->name, len);