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authorXie He <xie.he.0141@gmail.com>2020-10-31 21:10:43 +0300
committerJakub Kicinski <kuba@kernel.org>2020-11-04 02:19:21 +0300
commit54b77a77e30a5170a25cfd2f211e08ea5a6c0c4c (patch)
treeb03ee3ca633fd7d35cc9f77d2721ed9a0e80e4b3 /drivers/net/wan
parent77124c4463d45083e69b7284415467737f31f76b (diff)
downloadlinux-54b77a77e30a5170a25cfd2f211e08ea5a6c0c4c.tar.xz
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: Xie He <xie.he.0141@gmail.com> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'drivers/net/wan')
-rw-r--r--drivers/net/wan/hdlc_fr.c75
1 files 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);