Re: [PATCH net-next v4 5/5] net: hdlc_fr: Add support for any Ethertype
From: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Date: 2020-10-30 16:33:28
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On Thu, Oct 29, 2020 at 10:32 PM Xie He [off-list ref] wrote:
quoted hunk ↗ jump to hunk
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.kernel@gmail.com> Cc: Krzysztof Halasa <khc@pm.waw.pl> Signed-off-by: Xie He <redacted> --- 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 9a37575686b9..e95efc14bc97 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; }
quoted hunk ↗ jump to hunk
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 */
Should this still check data[5] == FR_PAD?
+ 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