[ATM]: [br2864] routed support

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

1 files changed, 116 insertions, 32 deletions

diff --git a/net/atm/br2684.c b/net/atm/br2684.c
index ba6428f204f..d9bb2a16b7c 100644
--- 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)