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: Willem de Bruijn <willemdebruijn.ker...@gmail.com>
Cc: Krzysztof Halasa <k...@pm.waw.pl>
Acked-by: Willem de Bruijn <will...@google.com>
Signed-off-by: Xie He <xie.he.0...@gmail.com>
---
drivers/net/wan/hdlc_fr.c | 75 +++++++++++++++++++++++++--------------
1 file changed, 49 insertions(+), 26 deletions(-)
diff --git a/drivers/net/wan/hdlc_fr.c b/drivers/net/wan/hdlc_fr.c
index 98444f1d8cc3..0720f5f92caa 100644
--- a/drivers/net/wan/hdlc_fr.c
+++ b/drivers/net/wan/hdlc_fr.c
@@ -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);
--
2.27.0
