Commit 54b77a77 authored by Xie He's avatar Xie He Committed by Jakub Kicinski
Browse files

net: hdlc_fr: Add support for any Ethertype 



Change the fr_rx function to make this driver support any Ethertype
when receiving skbs on normal (non-Ethernet-emulating) PVC devices.
(This driver is already able to handle any Ethertype when sending.)

Originally in the fr_rx function, the code that parses the long (10-byte)
header only recognizes a few Ethertype values and drops frames with other
Ethertype values. This patch replaces this code to make fr_rx support
any Ethertype. This patch also creates a new function fr_snap_parse as
part of the new code.

Cc: Krzysztof Halasa <khc@pm.waw.pl>
Signed-off-by: default avatarXie He <xie.he.0141@gmail.com>
Acked-by: default avatarWillem de Bruijn <willemb@google.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 77124c44

drivers/net/wan/hdlc_fr.c

+49 −26
Original line number Diff line number Diff line
@@ -871,6 +871,45 @@ static int fr_lmi_recv(struct net_device *dev, struct sk_buff *skb) 
	return 0;

}



static int fr_snap_parse(struct sk_buff *skb, struct pvc_device *pvc)

{

	/* OUI 00-00-00 indicates an Ethertype follows */

	if (skb->data[0] == 0x00 &&

	    skb->data[1] == 0x00 &&

	    skb->data[2] == 0x00) {

		if (!pvc->main)

			return -1;

		skb->dev = pvc->main;

		skb->protocol = *(__be16 *)(skb->data + 3); /* Ethertype */

		skb_pull(skb, 5);

		skb_reset_mac_header(skb);

		return 0;



	/* OUI 00-80-C2 stands for the 802.1 organization */

	} else if (skb->data[0] == 0x00 &&

		   skb->data[1] == 0x80 &&

		   skb->data[2] == 0xC2) {

		/* PID 00-07 stands for Ethernet frames without FCS */

		if (skb->data[3] == 0x00 &&

		    skb->data[4] == 0x07) {

			if (!pvc->ether)

				return -1;

			skb_pull(skb, 5);

			if (skb->len < ETH_HLEN)

				return -1;

			skb->protocol = eth_type_trans(skb, pvc->ether);

			return 0;



		/* PID unsupported */

		} else {

			return -1;

		}



	/* OUI unsupported */

	} else {

		return -1;

	}

}



static int fr_rx(struct sk_buff *skb)

{
@@ -945,35 +984,19 @@ static int fr_rx(struct sk_buff *skb) 
		skb->protocol = htons(ETH_P_IPV6);

		skb_reset_mac_header(skb);



	} else if (skb->len > 10 && data[3] == FR_PAD &&

		   data[4] == NLPID_SNAP && data[5] == FR_PAD) {

		u16 oui = ntohs(*(__be16*)(data + 6));

		u16 pid = ntohs(*(__be16*)(data + 8));

		skb_pull(skb, 10);



		switch ((((u32)oui) << 16) | pid) {

		case ETH_P_ARP: /* routed frame with SNAP */

		case ETH_P_IPX:

		case ETH_P_IP:	/* a long variant */

		case ETH_P_IPV6:

			if (!pvc->main)

				goto rx_drop;

			skb->dev = pvc->main;

			skb->protocol = htons(pid);

			skb_reset_mac_header(skb);

			break;



		case 0x80C20007: /* bridged Ethernet frame */

			if (!pvc->ether)

	} else if (data[3] == FR_PAD) {

		if (skb->len < 5)

			goto rx_error;

		if (data[4] == NLPID_SNAP) { /* A SNAP header follows */

			skb_pull(skb, 5);

			if (skb->len < 5) /* Incomplete SNAP header */

				goto rx_error;

			if (fr_snap_parse(skb, pvc))

				goto rx_drop;

			skb->protocol = eth_type_trans(skb, pvc->ether);

			break;



		default:

			netdev_info(frad, "Unsupported protocol, OUI=%x PID=%x\n",

				    oui, pid);

		} else {

			goto rx_drop;

		}



	} else {

		netdev_info(frad, "Unsupported protocol, NLPID=%x length=%i\n",

			    data[3], skb->len);

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