[ATM]: [br2864] routed support

Signed-off-by: Chas Williams <chas@cmf.nrl.navy.mil>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/linux/atmbr2684.h b/include/linux/atmbr2684.h
index 969fb6c..ccdab6c 100644 (file)
--- a/include/linux/atmbr2684.h
+++ b/include/linux/atmbr2684.h
@@ -14,6 +14,9 @@
 #define BR2684_MEDIA_FDDI      (3)
 #define BR2684_MEDIA_802_6     (4)     /* 802.6 */
 
+                                       /* used only at device creation:  */
+#define BR2684_FLAG_ROUTED     (1<<16) /* payload is routed, not bridged */
+
 /*
  * Is there FCS inbound on this VC?  This currently isn't supported.
  */
@@ -36,13 +39,21 @@
 #define BR2684_ENCAPS_AUTODETECT (2)   /* Unsuported */
 
 /*
+ * Is this VC bridged or routed?
+ */
+
+#define BR2684_PAYLOAD_ROUTED   (0)
+#define BR2684_PAYLOAD_BRIDGED  (1)
+
+
+/*
  * This is for the ATM_NEWBACKENDIF call - these are like socket families:
  * the first element of the structure is the backend number and the rest
  * is per-backend specific
  */
 struct atm_newif_br2684 {
        atm_backend_t   backend_num;    /* ATM_BACKEND_BR2684 */
-       int             media;          /* BR2684_MEDIA_* */
+       int             media;          /* BR2684_MEDIA_*, flags in upper bits */
        char            ifname[IFNAMSIZ];
        int             mtu;
 };
@@ -95,6 +106,11 @@ struct br2684_filter_set {
        struct br2684_filter filter;
 };
 
+enum br2684_payload {
+        p_routed = BR2684_PAYLOAD_ROUTED,
+        p_bridged = BR2684_PAYLOAD_BRIDGED,
+};
+
 #define BR2684_SETFILT _IOW( 'a', ATMIOC_BACKEND + 0, \
                                struct br2684_filter_set)
 

diff --git a/net/atm/br2684.c b/net/atm/br2684.c
index ba6428f..d9bb2a1 100644 (file)
--- a/net/atm/br2684.c
+++ b/net/atm/br2684.c
@@ -1,7 +1,8 @@
 /*
-Experimental ethernet netdevice using ATM AAL5 as underlying carrier
-(RFC1483 obsoleted by RFC2684) for Linux 2.4
-Author: Marcell GAL, 2000, XDSL Ltd, Hungary
+Ethernet netdevice using ATM AAL5 as underlying carrier
+(RFC1483 obsoleted by RFC2684) for Linux
+Authors: Marcell GAL, 2000, XDSL Ltd, Hungary
+         Eric Kinzie, 2006-2007, US Naval Research Laboratory
 */
 
 #include <linux/module.h>
@@ -39,9 +40,27 @@ static void skb_debug(const struct sk_buff *skb)
 #define skb_debug(skb) do {} while (0)
 #endif
 
+#define BR2684_ETHERTYPE_LEN   2
+#define BR2684_PAD_LEN         2
+
+#define LLC            0xaa, 0xaa, 0x03
+#define SNAP_BRIDGED   0x00, 0x80, 0xc2
+#define SNAP_ROUTED    0x00, 0x00, 0x00
+#define PID_ETHERNET   0x00, 0x07
+#define ETHERTYPE_IPV4 0x08, 0x00
+#define ETHERTYPE_IPV6 0x86, 0xdd
+#define PAD_BRIDGED    0x00, 0x00
+
+static unsigned char ethertype_ipv4[] =
+       { ETHERTYPE_IPV4 };
+static unsigned char ethertype_ipv6[] =
+       { ETHERTYPE_IPV6 };
 static unsigned char llc_oui_pid_pad[] =
-    { 0xAA, 0xAA, 0x03, 0x00, 0x80, 0xC2, 0x00, 0x07, 0x00, 0x00 };
-#define PADLEN (2)
+       { LLC, SNAP_BRIDGED, PID_ETHERNET, PAD_BRIDGED };
+static unsigned char llc_oui_ipv4[] =
+       { LLC, SNAP_ROUTED, ETHERTYPE_IPV4 };
+static unsigned char llc_oui_ipv6[] =
+       { LLC, SNAP_ROUTED, ETHERTYPE_IPV6 };
 
 enum br2684_encaps {
        e_vc  = BR2684_ENCAPS_VC,
@@ -69,6 +88,7 @@ struct br2684_dev {
        struct list_head brvccs; /* one device <=> one vcc (before xmas) */
        struct net_device_stats stats;
        int mac_was_set;
+       enum br2684_payload payload;
 };
 
 /*
@@ -136,6 +156,7 @@ static int br2684_xmit_vcc(struct sk_buff *skb, struct br2684_dev *brdev,
 {
        struct atm_vcc *atmvcc;
        int minheadroom = (brvcc->encaps == e_llc) ? 10 : 2;
+
        if (skb_headroom(skb) < minheadroom) {
                struct sk_buff *skb2 = skb_realloc_headroom(skb, minheadroom);
                brvcc->copies_needed++;
@@ -146,11 +167,32 @@ static int br2684_xmit_vcc(struct sk_buff *skb, struct br2684_dev *brdev,
                }
                skb = skb2;
        }
-       skb_push(skb, minheadroom);
-       if (brvcc->encaps == e_llc)
-               skb_copy_to_linear_data(skb, llc_oui_pid_pad, 10);
-       else
-               memset(skb->data, 0, 2);
+
+       if (brvcc->encaps == e_llc) {
+               if (brdev->payload == p_bridged) {
+                       skb_push(skb, sizeof(llc_oui_pid_pad));
+                       skb_copy_to_linear_data(skb, llc_oui_pid_pad, sizeof(llc_oui_pid_pad));
+               } else if (brdev->payload == p_routed) {
+                       unsigned short prot = ntohs(skb->protocol);
+
+                       skb_push(skb, sizeof(llc_oui_ipv4));
+                       switch (prot) {
+                               case ETH_P_IP:
+                                       skb_copy_to_linear_data(skb, llc_oui_ipv4, sizeof(llc_oui_ipv4));
+                                       break;
+                               case ETH_P_IPV6:
+                                       skb_copy_to_linear_data(skb, llc_oui_ipv6, sizeof(llc_oui_ipv6));
+                                       break;
+                               default:
+                                       dev_kfree_skb(skb);
+                                       return 0;
+                       }
+               }
+       } else {
+               skb_push(skb, 2);
+               if (brdev->payload == p_bridged)
+                       memset(skb->data, 0, 2);
+       }
        skb_debug(skb);
 
        ATM_SKB(skb)->vcc = atmvcc = brvcc->atmvcc;
@@ -299,7 +341,6 @@ static void br2684_push(struct atm_vcc *atmvcc, struct sk_buff *skb)
        struct br2684_vcc *brvcc = BR2684_VCC(atmvcc);
        struct net_device *net_dev = brvcc->device;
        struct br2684_dev *brdev = BRPRIV(net_dev);
-       int plen = sizeof(llc_oui_pid_pad) + ETH_HLEN;
 
        pr_debug("br2684_push\n");
 
@@ -320,35 +361,50 @@ static void br2684_push(struct atm_vcc *atmvcc, struct sk_buff *skb)
        atm_return(atmvcc, skb->truesize);
        pr_debug("skb from brdev %p\n", brdev);
        if (brvcc->encaps == e_llc) {
+
+               if (skb->len > 7 && skb->data[7] == 0x01)
+                       __skb_trim(skb, skb->len - 4);
+
+               /* accept packets that have "ipv[46]" in the snap header */
+               if ((skb->len >= (sizeof(llc_oui_ipv4)))
+                   && (memcmp(skb->data, llc_oui_ipv4, sizeof(llc_oui_ipv4) - BR2684_ETHERTYPE_LEN) == 0)) {
+                       if (memcmp(skb->data + 6, ethertype_ipv6, sizeof(ethertype_ipv6)) == 0)
+                               skb->protocol = __constant_htons(ETH_P_IPV6);
+                       else if (memcmp(skb->data + 6, ethertype_ipv4, sizeof(ethertype_ipv4)) == 0)
+                               skb->protocol = __constant_htons(ETH_P_IP);
+                       else {
+                               brdev->stats.rx_errors++;
+                               dev_kfree_skb(skb);
+                               return;
+                       }
+                       skb_pull(skb, sizeof(llc_oui_ipv4));
+                       skb_reset_network_header(skb);
+                       skb->pkt_type = PACKET_HOST;
+
                /* let us waste some time for checking the encapsulation.
                   Note, that only 7 char is checked so frames with a valid FCS
                   are also accepted (but FCS is not checked of course) */
-               if (memcmp(skb->data, llc_oui_pid_pad, 7)) {
+               } else if ((skb->len >= sizeof(llc_oui_pid_pad)) &&
+                          (memcmp(skb->data, llc_oui_pid_pad, 7) == 0)) {
+                       skb_pull(skb, sizeof(llc_oui_pid_pad));
+                       skb->protocol = eth_type_trans(skb, net_dev);
+               } else {
                        brdev->stats.rx_errors++;
                        dev_kfree_skb(skb);
                        return;
                }
 
-               /* Strip FCS if present */
-               if (skb->len > 7 && skb->data[7] == 0x01)
-                       __skb_trim(skb, skb->len - 4);
        } else {
-               plen = PADLEN + ETH_HLEN;       /* pad, dstmac,srcmac, ethtype */
                /* first 2 chars should be 0 */
                if (*((u16 *) (skb->data)) != 0) {
                        brdev->stats.rx_errors++;
                        dev_kfree_skb(skb);
                        return;
                }
-       }
-       if (skb->len < plen) {
-               brdev->stats.rx_errors++;
-               dev_kfree_skb(skb);     /* dev_ not needed? */
-               return;
+               skb_pull(skb, BR2684_PAD_LEN + ETH_HLEN); /* pad, dstmac, srcmac, ethtype */
+               skb->protocol = eth_type_trans(skb, net_dev);
        }
 
-       skb_pull(skb, plen - ETH_HLEN);
-       skb->protocol = eth_type_trans(skb, net_dev);
 #ifdef CONFIG_ATM_BR2684_IPFILTER
        if (unlikely(packet_fails_filter(skb->protocol, brvcc, skb))) {
                brdev->stats.rx_dropped++;
@@ -482,25 +538,52 @@ static void br2684_setup(struct net_device *netdev)
        INIT_LIST_HEAD(&brdev->brvccs);
 }
 
+static void br2684_setup_routed(struct net_device *netdev)
+{
+       struct br2684_dev *brdev = BRPRIV(netdev);
+       brdev->net_dev = netdev;
+
+       netdev->hard_header_len = 0;
+       my_eth_mac_addr = netdev->set_mac_address;
+       netdev->set_mac_address = br2684_mac_addr;
+       netdev->hard_start_xmit = br2684_start_xmit;
+       netdev->get_stats = br2684_get_stats;
+       netdev->addr_len = 0;
+       netdev->mtu = 1500;
+       netdev->type = ARPHRD_PPP;
+       netdev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
+       netdev->tx_queue_len = 100;
+       INIT_LIST_HEAD(&brdev->brvccs);
+}
+
 static int br2684_create(void __user *arg)
 {
        int err;
        struct net_device *netdev;
        struct br2684_dev *brdev;
        struct atm_newif_br2684 ni;
+       enum br2684_payload payload;
 
        pr_debug("br2684_create\n");
 
        if (copy_from_user(&ni, arg, sizeof ni)) {
                return -EFAULT;
        }
+
+       if (ni.media & BR2684_FLAG_ROUTED)
+               payload = p_routed;
+       else
+               payload = p_bridged;
+       ni.media &= 0xffff; /* strip flags */
+
        if (ni.media != BR2684_MEDIA_ETHERNET || ni.mtu != 1500) {
                return -EINVAL;
        }
 
        netdev = alloc_netdev(sizeof(struct br2684_dev),
                              ni.ifname[0] ? ni.ifname : "nas%d",
-                             br2684_setup);
+                             (payload == p_routed) ?
+                              br2684_setup_routed : br2684_setup);
        if (!netdev)
                return -ENOMEM;
 
@@ -516,6 +599,7 @@ static int br2684_create(void __user *arg)
        }
 
        write_lock_irq(&devs_lock);
+       brdev->payload = payload;
        brdev->number = list_empty(&br2684_devs) ? 1 :
            BRPRIV(list_entry_brdev(br2684_devs.prev))->number + 1;
        list_add_tail(&brdev->br2684_devs, &br2684_devs);
@@ -601,14 +685,14 @@ static int br2684_seq_show(struct seq_file *seq, void *v)
                   brdev->mac_was_set ? "set" : "auto");
 
        list_for_each_entry(brvcc, &brdev->brvccs, brvccs) {
-               seq_printf(seq, "  vcc %d.%d.%d: encaps=%s"
-                                   ", failed copies %u/%u"
-                                   "\n", brvcc->atmvcc->dev->number,
-                                   brvcc->atmvcc->vpi, brvcc->atmvcc->vci,
-                                   (brvcc->encaps == e_llc) ? "LLC" : "VC"
-                                   , brvcc->copies_failed
-                                   , brvcc->copies_needed
-                                   );
+               seq_printf(seq, "  vcc %d.%d.%d: encaps=%s payload=%s"
+                               ", failed copies %u/%u"
+                               "\n", brvcc->atmvcc->dev->number,
+                                     brvcc->atmvcc->vpi, brvcc->atmvcc->vci,
+                                     (brvcc->encaps == e_llc) ? "LLC" : "VC",
+                                     (brdev->payload == p_bridged) ? "bridged" : "routed",
+                                     brvcc->copies_failed,
+                                     brvcc->copies_needed);
 #ifdef CONFIG_ATM_BR2684_IPFILTER
 #define b1(var, byte)  ((u8 *) &brvcc->filter.var)[byte]
 #define bs(var)                b1(var, 0), b1(var, 1), b1(var, 2), b1(var, 3)