niansa-misc/linux
1
0
Fork 0
mirror of synced 2025-03-06 20:59:54 +01:00
Code Issues Projects Releases Packages Wiki Activity

net: hdlc_fr: Add support for any Ethertype

Browse source 
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>
This commit is contained in:
Xie He 2020-10-31 11:10:43 -07:00 • committed by Jakub Kicinski
parent 77124c4463
commit 54b77a77e3
1 changed files with 49 additions and 26 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

75
drivers/net/wan/hdlc_fr.c
View file

@ -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)
} 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->dev = pvc->main;
skb->protocol = htons(pid);
skb_reset_mac_header(skb);
break;
case 0x80C20007: /* bridged Ethernet frame */
if (!pvc->ether)
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);