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[ATM]: [br2864] routed support
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Signed-off-by: Chas Williams <chas@cmf.nrl.navy.mil>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Eric Kinzie authored and David S. Miller committed Jan 28, 2008
1 parent 900092a commit 097b19a
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Showing 2 changed files with 133 additions and 33 deletions.
18 changes: 17 additions & 1 deletion include/linux/atmbr2684.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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.
*/
Expand All @@ -35,14 +38,22 @@
#define BR2684_ENCAPS_LLC (1)
#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;
};
Expand Down Expand Up @@ -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)

Expand Down
148 changes: 116 additions & 32 deletions net/atm/br2684.c
View file
Original file line number Diff line number Diff line change
@@ -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>
Expand Down Expand Up @@ -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,
Expand Down Expand Up @@ -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;
};

/*
Expand Down Expand Up @@ -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++;
Expand All @@ -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;
Expand Down Expand Up @@ -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");

Expand All @@ -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++;
Expand Down Expand Up @@ -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;

Expand All @@ -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);
Expand Down Expand Up @@ -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)
Expand Down

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