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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
commitf4cdf7ca9a1fdcca413157df19753f388a5a224e (patch)
tree60a31895b2446cd7fa27514e8c2843534a0de0da /net/802/psnap.c
downloadlinux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.tar.gz
linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.zip
Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab: - v4l2-core: added ISP statistics support and per-block validation - v4l2-core: Allow unknown HDR10 white point and luminance - New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor - New codec: Milos: VPU v2.0 codec support - isp driver: gained support for Dreamchip RPPX1 ISP framework - vsp1 driver: gained support for RZ/T2H and RZ/N2H - Novalake driver: gained CVS support for new NVL hardware - dvb-core: fix feed leak on failed DMX_ADD_PID - several driver fixes, cleanups and minor improvements * tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits) media: ipu-bridge: check all DMI entries when overriding sensor rotation media: v4l2-async: avoid deleting unlinked ASC entry on link error media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement media: intel/ipu6: fix async notifier cleanup leak on parse error media: staging/ipu7: fix async notifier UAF on probe error path media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem() media: rcar-isp: Fix VSPX reference leaks media: rcar-isp: Release ISPCORE resources media: i2c: imx415: Release runtime PM reference on VBLANK error media: i2c: imx415: Return test pattern write errors media: renesas: vsp1: Declare index variables in for loop statement media: renesas: vsp1: Make reset control optional to support platforms without a reset line media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs media: nxp: imx8-isi: Add additional 32-bit RGB format support media: nxp: imx8-isi: Add 16-bit raw Bayer format support media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks media: nxp: imx8-isi: Correct color map between V4L2 and ISI ...
Diffstat (limited to 'net/802/psnap.c')
-rw-r--r--net/802/psnap.c164
1 files changed, 164 insertions, 0 deletions
diff --git a/net/802/psnap.c b/net/802/psnap.c
new file mode 100644
index 000000000..8ae835e1c
--- /dev/null
+++ b/net/802/psnap.c
@@ -0,0 +1,164 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * SNAP data link layer. Derived from 802.2
+ *
+ * Alan Cox <alan@lxorguk.ukuu.org.uk>,
+ * from the 802.2 layer by Greg Page.
+ * Merged in additions from Greg Page's psnap.c.
+ */
+
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <net/datalink.h>
+#include <net/llc.h>
+#include <net/psnap.h>
+#include <linux/mm.h>
+#include <linux/in.h>
+#include <linux/init.h>
+#include <linux/rculist.h>
+
+static LIST_HEAD(snap_list);
+static DEFINE_SPINLOCK(snap_lock);
+static struct llc_sap *snap_sap;
+
+/*
+ * Find a snap client by matching the 5 bytes.
+ */
+static struct datalink_proto *find_snap_client(const unsigned char *desc)
+{
+ struct datalink_proto *proto = NULL, *p;
+
+ list_for_each_entry_rcu(p, &snap_list, node, lockdep_is_held(&snap_lock)) {
+ if (!memcmp(p->type, desc, 5)) {
+ proto = p;
+ break;
+ }
+ }
+ return proto;
+}
+
+/*
+ * A SNAP packet has arrived
+ */
+static int snap_rcv(struct sk_buff *skb, struct net_device *dev,
+ struct packet_type *pt, struct net_device *orig_dev)
+{
+ int rc = 1;
+ struct datalink_proto *proto;
+ static struct packet_type snap_packet_type = {
+ .type = cpu_to_be16(ETH_P_SNAP),
+ };
+
+ if (unlikely(!pskb_may_pull(skb, 5)))
+ goto drop;
+
+ rcu_read_lock();
+ proto = find_snap_client(skb->data);
+ if (proto) {
+ /* Pass the frame on. */
+ skb_pull_rcsum(skb, 5);
+ skb_reset_transport_header(skb);
+ rc = proto->rcvfunc(skb, dev, &snap_packet_type, orig_dev);
+ }
+ rcu_read_unlock();
+
+ if (unlikely(!proto))
+ goto drop;
+
+out:
+ return rc;
+
+drop:
+ kfree_skb(skb);
+ goto out;
+}
+
+/*
+ * Put a SNAP header on a frame and pass to 802.2
+ */
+static int snap_request(struct datalink_proto *dl,
+ struct sk_buff *skb, const u8 *dest)
+{
+ memcpy(skb_push(skb, 5), dl->type, 5);
+ llc_build_and_send_ui_pkt(snap_sap, skb, dest, snap_sap->laddr.lsap);
+ return 0;
+}
+
+/*
+ * Set up the SNAP layer
+ */
+EXPORT_SYMBOL(register_snap_client);
+EXPORT_SYMBOL(unregister_snap_client);
+
+static const char snap_err_msg[] __initconst =
+ KERN_CRIT "SNAP - unable to register with 802.2\n";
+
+static int __init snap_init(void)
+{
+ snap_sap = llc_sap_open(0xAA, snap_rcv);
+ if (!snap_sap) {
+ printk(snap_err_msg);
+ return -EBUSY;
+ }
+
+ return 0;
+}
+
+module_init(snap_init);
+
+static void __exit snap_exit(void)
+{
+ llc_sap_put(snap_sap);
+}
+
+module_exit(snap_exit);
+
+
+/*
+ * Register SNAP clients. We don't yet use this for IP.
+ */
+struct datalink_proto *register_snap_client(const unsigned char *desc,
+ int (*rcvfunc)(struct sk_buff *,
+ struct net_device *,
+ struct packet_type *,
+ struct net_device *))
+{
+ struct datalink_proto *proto = NULL;
+
+ spin_lock_bh(&snap_lock);
+
+ if (find_snap_client(desc))
+ goto out;
+
+ proto = kmalloc_obj(*proto, GFP_ATOMIC);
+ if (proto) {
+ memcpy(proto->type, desc, 5);
+ proto->rcvfunc = rcvfunc;
+ proto->header_length = 5 + 3; /* snap + 802.2 */
+ proto->request = snap_request;
+ list_add_rcu(&proto->node, &snap_list);
+ }
+out:
+ spin_unlock_bh(&snap_lock);
+
+ return proto;
+}
+
+/*
+ * Unregister SNAP clients. Protocols no longer want to play with us ...
+ */
+void unregister_snap_client(struct datalink_proto *proto)
+{
+ spin_lock_bh(&snap_lock);
+ list_del_rcu(&proto->node);
+ spin_unlock_bh(&snap_lock);
+
+ synchronize_net();
+
+ kfree(proto);
+}
+
+MODULE_DESCRIPTION("SNAP data link layer. Derived from 802.2");
+MODULE_LICENSE("GPL");