| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-Id: <20260107-ks8995-dsa-tagging-v1-1-1a92832c1540@kernel.org>
Date: Wed, 07 Jan 2026 13:57:14 +0100
From: Linus Walleij <linusw@...nel.org>
To: Andrew Lunn <andrew@...n.ch>, Vladimir Oltean <olteanv@...il.com>,
"David S. Miller" <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>,
Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>,
Simon Horman <horms@...nel.org>
Cc: netdev@...r.kernel.org, Linus Walleij <linusw@...nel.org>
Subject: [PATCH net-next 1/2] net: dsa: tag_ks8995: Add the KS8995 tag
handling
The KS8995 100Mbit switch can do proper DSA per-port tagging
with the proper set-up. This adds the code to handle ingress
and egress KS8995 tags.
The tag is a modified 0x8100 ethertype tag where a bit in the
last byte is set for each target port.
Signed-off-by: Linus Walleij <linusw@...nel.org>
---
include/net/dsa.h | 2 +
net/dsa/Kconfig | 6 +++
net/dsa/Makefile | 1 +
net/dsa/tag_ks8995.c | 114 +++++++++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 123 insertions(+)
diff --git a/include/net/dsa.h b/include/net/dsa.h
index cced1a866757..b4c1ac14d051 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -57,6 +57,7 @@ struct tc_action;
#define DSA_TAG_PROTO_BRCM_LEGACY_FCS_VALUE 29
#define DSA_TAG_PROTO_YT921X_VALUE 30
#define DSA_TAG_PROTO_MXL_GSW1XX_VALUE 31
+#define DSA_TAG_PROTO_KS8995_VALUE 32
enum dsa_tag_protocol {
DSA_TAG_PROTO_NONE = DSA_TAG_PROTO_NONE_VALUE,
@@ -91,6 +92,7 @@ enum dsa_tag_protocol {
DSA_TAG_PROTO_VSC73XX_8021Q = DSA_TAG_PROTO_VSC73XX_8021Q_VALUE,
DSA_TAG_PROTO_YT921X = DSA_TAG_PROTO_YT921X_VALUE,
DSA_TAG_PROTO_MXL_GSW1XX = DSA_TAG_PROTO_MXL_GSW1XX_VALUE,
+ DSA_TAG_PROTO_KS8995 = DSA_TAG_PROTO_KS8995_VALUE,
};
struct dsa_switch;
diff --git a/net/dsa/Kconfig b/net/dsa/Kconfig
index f86b30742122..c5272dc7af88 100644
--- a/net/dsa/Kconfig
+++ b/net/dsa/Kconfig
@@ -112,6 +112,12 @@ config NET_DSA_TAG_MXL_GSW1XX
Say Y or M if you want to enable support for tagging frames for
MaxLinear GSW1xx switches.
+config NET_DSA_TAG_KS8995
+ tristate "Tag driver for Micrel KS8995 switch"
+ help
+ Say Y if you want to enable support for tagging frames for the
+ Micrel KS8995 switch.
+
config NET_DSA_TAG_KSZ
tristate "Tag driver for Microchip 8795/937x/9477/9893 families of switches"
help
diff --git a/net/dsa/Makefile b/net/dsa/Makefile
index 42d173f5a701..03eed7653a34 100644
--- a/net/dsa/Makefile
+++ b/net/dsa/Makefile
@@ -25,6 +25,7 @@ obj-$(CONFIG_NET_DSA_TAG_BRCM_COMMON) += tag_brcm.o
obj-$(CONFIG_NET_DSA_TAG_DSA_COMMON) += tag_dsa.o
obj-$(CONFIG_NET_DSA_TAG_GSWIP) += tag_gswip.o
obj-$(CONFIG_NET_DSA_TAG_HELLCREEK) += tag_hellcreek.o
+obj-$(CONFIG_NET_DSA_TAG_KS8995) += tag_ks8995.o
obj-$(CONFIG_NET_DSA_TAG_KSZ) += tag_ksz.o
obj-$(CONFIG_NET_DSA_TAG_LAN9303) += tag_lan9303.o
obj-$(CONFIG_NET_DSA_TAG_MTK) += tag_mtk.o
diff --git a/net/dsa/tag_ks8995.c b/net/dsa/tag_ks8995.c
new file mode 100644
index 000000000000..a5adda4767a3
--- /dev/null
+++ b/net/dsa/tag_ks8995.c
@@ -0,0 +1,114 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2025 Linus Walleij <linusw@...nel.org>
+ */
+#include <linux/etherdevice.h>
+#include <linux/log2.h>
+#include <linux/list.h>
+#include <linux/slab.h>
+
+#include "tag.h"
+
+/* The KS8995 Special Tag Packet ID (STPID)
+ * pushes its tag in a way similar to a VLAN tag
+ * -----------------------------------------------------------
+ * | MAC DA | MAC SA | 2 bytes tag | 2 bytes TCI | EtherType |
+ * -----------------------------------------------------------
+ * The tag is: 0x8100 |= BIT(port), ports 0,1,2,3
+ */
+
+#define KS8995_NAME "ks8995"
+
+#define KS8995_TAG_LEN 4
+
+static struct sk_buff *ks8995_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ struct dsa_port *dp = dsa_user_to_port(dev);
+ u16 ks8995_tag;
+ __be16 *p;
+ u16 port;
+ u16 tci;
+
+ /* Prepare the special KS8995 tags */
+ port = dsa_xmit_port_mask(skb, dev);
+ /* The manual says to set this to the CPU port if no port is indicated */
+ if (!port)
+ port = BIT(5);
+
+ ks8995_tag = ETH_P_8021Q | port;
+ tci = port & VLAN_VID_MASK;
+
+ /* Push in a tag between MAC and ethertype */
+ netdev_dbg(dev, "egress packet tag: add tag %04x %04x to port %d\n",
+ ks8995_tag, tci, dp->index);
+
+ skb_push(skb, KS8995_TAG_LEN);
+ dsa_alloc_etype_header(skb, KS8995_TAG_LEN);
+
+ p = dsa_etype_header_pos_tx(skb);
+ p[0] = htons(ks8995_tag);
+ p[1] = htons(tci);
+
+ return skb;
+}
+
+static struct sk_buff *ks8995_rcv(struct sk_buff *skb, struct net_device *dev)
+{
+ unsigned int port;
+ __be16 *p;
+ u16 etype;
+ u16 tci;
+
+ if (unlikely(!pskb_may_pull(skb, KS8995_TAG_LEN))) {
+ netdev_err(dev, "dropping packet, cannot pull\n");
+ return NULL;
+ }
+
+ p = dsa_etype_header_pos_rx(skb);
+ etype = ntohs(p[0]);
+
+ if (etype == ETH_P_8021Q) {
+ /* That's just an ordinary VLAN tag, pass through */
+ return skb;
+ }
+
+ if ((etype & 0xFFF0U) != ETH_P_8021Q) {
+ /* Not custom, just pass through */
+ netdev_dbg(dev, "non-KS8995 ethertype 0x%04x\n", etype);
+ return skb;
+ }
+
+ port = ilog2(etype & 0xF);
+ tci = ntohs(p[1]);
+ netdev_dbg(dev, "ingress packet tag: %04x %04x, port %d\n",
+ etype, tci, port);
+
+ skb->dev = dsa_conduit_find_user(dev, 0, port);
+ if (!skb->dev) {
+ netdev_err(dev, "could not find user for port %d\n", port);
+ return NULL;
+ }
+
+ /* Remove KS8995 tag and recalculate checksum */
+ skb_pull_rcsum(skb, KS8995_TAG_LEN);
+
+ dsa_strip_etype_header(skb, KS8995_TAG_LEN);
+
+ dsa_default_offload_fwd_mark(skb);
+
+ return skb;
+}
+
+static const struct dsa_device_ops ks8995_netdev_ops = {
+ .name = KS8995_NAME,
+ .proto = DSA_TAG_PROTO_KS8995,
+ .xmit = ks8995_xmit,
+ .rcv = ks8995_rcv,
+ .needed_headroom = KS8995_TAG_LEN,
+};
+
+MODULE_DESCRIPTION("DSA tag driver for Micrel KS8995 family of switches");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_KS8995, KS8995_NAME);
+
+module_dsa_tag_driver(ks8995_netdev_ops);
--
2.52.0
Powered by blists - more mailing lists