ftrace: Synchronize the initialization of ftrace_opsgrafted

There's some internal state that ftrace_ops needs to have set, but since
it can be declared outside of the ftrace.c code, it calls
ftrace_ops_init() on the ops in every global function. The issue is that
if two tasks call it on the same ops at the same time it is possible to
have the initialization of one corrupt the initialization of the other
call.

Create a ops_mutex to use to synchronize every initialization of the
ftrace_ops. The mutex is taken within checking the ftrace_ops flag that
states it was initializied but the flag is checked again after the mutex
has been taken. Checking first outside the mutex allows it to shortcut
having to take the mutex. But then the check needs to be done again after
the mute is taken in case of races.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home
Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock")
Reported-by: sashiko-bot@kernel.org
Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

15 files changed, 3787 insertions, 0 deletions

diff --git a/net/atm/Kconfig b/net/atm/Kconfig
new file mode 100644
index 000000000..dfdc3a855
--- /dev/null
+++ b/net/atm/Kconfig
@@ -0,0 +1,37 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Asynchronous Transfer Mode (ATM)
+#
+
+config ATM
+	tristate "Asynchronous Transfer Mode (ATM)"
+	help
+	  ATM is a high-speed networking technology for Local Area Networks
+	  and Wide Area Networks.  It uses a fixed packet size and is
+	  connection oriented, allowing for the negotiation of minimum
+	  bandwidth requirements.
+
+	  In order to participate in an ATM network, your Linux box needs an
+	  ATM networking card. If you have that, say Y here and to the driver
+	  of your ATM card below.
+
+	  Note that you need a set of user-space programs to actually make use
+	  of ATM.  See the file <file:Documentation/networking/atm.rst> for
+	  further details.
+
+config ATM_BR2684
+	tristate "RFC1483/2684 Bridged protocols"
+	depends on ATM && INET
+	help
+	  ATM PVCs can carry ethernet PDUs according to RFC2684 (formerly 1483)
+	  This device will act like an ethernet from the kernels point of view,
+	  with the traffic being carried by ATM PVCs (currently 1 PVC/device).
+	  This is sometimes used over DSL lines.  If in doubt, say N.
+
+config ATM_BR2684_IPFILTER
+	bool "Per-VC IP filter kludge"
+	depends on ATM_BR2684
+	help
+	  This is an experimental mechanism for users who need to terminate a
+	  large number of IP-only vcc's.  Do not enable this unless you are sure
+	  you know what you are doing.
diff --git a/net/atm/Makefile b/net/atm/Makefile
new file mode 100644
index 000000000..0a14ea7d4
--- /dev/null
+++ b/net/atm/Makefile
@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the ATM Protocol Families.
+#
+
+atm-y		:= pvc.o ioctl.o common.o atm_misc.o raw.o resources.o atm_sysfs.o
+
+obj-$(CONFIG_ATM) += atm.o
+obj-$(CONFIG_ATM_BR2684) += br2684.o
+atm-$(CONFIG_PROC_FS) += proc.o
+
+obj-$(CONFIG_PPPOATM) += pppoatm.o
diff --git a/net/atm/atm_misc.c b/net/atm/atm_misc.c
new file mode 100644
index 000000000..c9d7609da
--- /dev/null
+++ b/net/atm/atm_misc.c
@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: GPL-2.0
+/* net/atm/atm_misc.c - Various functions for use by ATM drivers */
+
+/* Written 1995-2000 by Werner Almesberger, EPFL ICA */
+
+#include <linux/module.h>
+#include <linux/atm.h>
+#include <linux/atmdev.h>
+#include <linux/skbuff.h>
+#include <linux/bitops.h>
+#include <linux/errno.h>
+#include <linux/atomic.h>
+
+int atm_charge(struct atm_vcc *vcc, int truesize)
+{
+	atm_force_charge(vcc, truesize);
+	if (atomic_read(&sk_atm(vcc)->sk_rmem_alloc) <= sk_atm(vcc)->sk_rcvbuf)
+		return 1;
+	atm_return(vcc, truesize);
+	atomic_inc(&vcc->stats->rx_drop);
+	return 0;
+}
+EXPORT_SYMBOL(atm_charge);
diff --git a/net/atm/atm_sysfs.c b/net/atm/atm_sysfs.c
new file mode 100644
index 000000000..0676a9c33
--- /dev/null
+++ b/net/atm/atm_sysfs.c
@@ -0,0 +1,158 @@
+// SPDX-License-Identifier: GPL-2.0
+/* ATM driver model support. */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/kobject.h>
+#include <linux/atmdev.h>
+#include "common.h"
+#include "resources.h"
+
+#define to_atm_dev(cldev) container_of(cldev, struct atm_dev, class_dev)
+
+static ssize_t type_show(struct device *cdev,
+			 struct device_attribute *attr, char *buf)
+{
+	struct atm_dev *adev = to_atm_dev(cdev);
+
+	return scnprintf(buf, PAGE_SIZE, "%s\n", adev->type);
+}
+
+static ssize_t address_show(struct device *cdev,
+			    struct device_attribute *attr, char *buf)
+{
+	struct atm_dev *adev = to_atm_dev(cdev);
+
+	return scnprintf(buf, PAGE_SIZE, "%pM\n", adev->esi);
+}
+
+static ssize_t atmindex_show(struct device *cdev,
+			     struct device_attribute *attr, char *buf)
+{
+	struct atm_dev *adev = to_atm_dev(cdev);
+
+	return scnprintf(buf, PAGE_SIZE, "%d\n", adev->number);
+}
+
+static ssize_t carrier_show(struct device *cdev,
+			    struct device_attribute *attr, char *buf)
+{
+	struct atm_dev *adev = to_atm_dev(cdev);
+
+	return scnprintf(buf, PAGE_SIZE, "%d\n",
+			 adev->signal == ATM_PHY_SIG_LOST ? 0 : 1);
+}
+
+static ssize_t link_rate_show(struct device *cdev,
+			      struct device_attribute *attr, char *buf)
+{
+	struct atm_dev *adev = to_atm_dev(cdev);
+	int link_rate;
+
+	/* show the link rate, not the data rate */
+	switch (adev->link_rate) {
+	case ATM_OC3_PCR:
+		link_rate = 155520000;
+		break;
+	case ATM_OC12_PCR:
+		link_rate = 622080000;
+		break;
+	case ATM_25_PCR:
+		link_rate = 25600000;
+		break;
+	default:
+		link_rate = adev->link_rate * 8 * 53;
+	}
+	return scnprintf(buf, PAGE_SIZE, "%d\n", link_rate);
+}
+
+static DEVICE_ATTR_RO(address);
+static DEVICE_ATTR_RO(atmindex);
+static DEVICE_ATTR_RO(carrier);
+static DEVICE_ATTR_RO(type);
+static DEVICE_ATTR_RO(link_rate);
+
+static struct device_attribute *atm_attrs[] = {
+	&dev_attr_address,
+	&dev_attr_atmindex,
+	&dev_attr_carrier,
+	&dev_attr_type,
+	&dev_attr_link_rate,
+	NULL
+};
+
+
+static int atm_uevent(const struct device *cdev, struct kobj_uevent_env *env)
+{
+	const struct atm_dev *adev;
+
+	if (!cdev)
+		return -ENODEV;
+
+	adev = to_atm_dev(cdev);
+
+	if (add_uevent_var(env, "NAME=%s%d", adev->type, adev->number))
+		return -ENOMEM;
+
+	return 0;
+}
+
+static void atm_release(struct device *cdev)
+{
+	struct atm_dev *adev = to_atm_dev(cdev);
+
+	kfree(adev);
+}
+
+static struct class atm_class = {
+	.name		= "atm",
+	.dev_release	= atm_release,
+	.dev_uevent		= atm_uevent,
+};
+
+int atm_register_sysfs(struct atm_dev *adev, struct device *parent)
+{
+	struct device *cdev = &adev->class_dev;
+	int i, j, err;
+
+	cdev->class = &atm_class;
+	cdev->parent = parent;
+	dev_set_drvdata(cdev, adev);
+
+	dev_set_name(cdev, "%s%d", adev->type, adev->number);
+	err = device_register(cdev);
+	if (err < 0)
+		return err;
+
+	for (i = 0; atm_attrs[i]; i++) {
+		err = device_create_file(cdev, atm_attrs[i]);
+		if (err)
+			goto err_out;
+	}
+
+	return 0;
+
+err_out:
+	for (j = 0; j < i; j++)
+		device_remove_file(cdev, atm_attrs[j]);
+	device_del(cdev);
+	return err;
+}
+
+void atm_unregister_sysfs(struct atm_dev *adev)
+{
+	struct device *cdev = &adev->class_dev;
+
+	device_del(cdev);
+}
+
+int __init atm_sysfs_init(void)
+{
+	return class_register(&atm_class);
+}
+
+void __exit atm_sysfs_exit(void)
+{
+	class_unregister(&atm_class);
+}
diff --git a/net/atm/br2684.c b/net/atm/br2684.c
new file mode 100644
index 000000000..05712c283
--- /dev/null
+++ b/net/atm/br2684.c
@@ -0,0 +1,871 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Ethernet netdevice using ATM AAL5 as underlying carrier
+ * (RFC1483 obsoleted by RFC2684) for Linux
+ *
+ * Authors: Marcell GAL, 2000, XDSL Ltd, Hungary
+ *          Eric Kinzie, 2006-2007, US Naval Research Laboratory
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/etherdevice.h>
+#include <linux/rtnetlink.h>
+#include <linux/ip.h>
+#include <linux/uaccess.h>
+#include <linux/slab.h>
+#include <net/arp.h>
+#include <linux/atm.h>
+#include <linux/atmdev.h>
+#include <linux/capability.h>
+#include <linux/seq_file.h>
+
+#include <linux/atmbr2684.h>
+
+#include "common.h"
+
+static void skb_debug(const struct sk_buff *skb)
+{
+#ifdef SKB_DEBUG
+#define NUM2PRINT 50
+	print_hex_dump(KERN_DEBUG, "br2684: skb: ", DUMP_OFFSET,
+		       16, 1, skb->data, min(NUM2PRINT, skb->len), true);
+#endif
+}
+
+#define BR2684_ETHERTYPE_LEN	2
+#define BR2684_PAD_LEN		2
+
+#define LLC		0xaa, 0xaa, 0x03
+#define SNAP_BRIDGED	0x00, 0x80, 0xc2
+#define SNAP_ROUTED	0x00, 0x00, 0x00
+#define PID_ETHERNET	0x00, 0x07
+#define ETHERTYPE_IPV4	0x08, 0x00
+#define ETHERTYPE_IPV6	0x86, 0xdd
+#define PAD_BRIDGED	0x00, 0x00
+
+static const unsigned char ethertype_ipv4[] = { ETHERTYPE_IPV4 };
+static const unsigned char ethertype_ipv6[] = { ETHERTYPE_IPV6 };
+static const unsigned char llc_oui_pid_pad[] =
+			{ LLC, SNAP_BRIDGED, PID_ETHERNET, PAD_BRIDGED };
+static const unsigned char pad[] = { PAD_BRIDGED };
+static const unsigned char llc_oui_ipv4[] = { LLC, SNAP_ROUTED, ETHERTYPE_IPV4 };
+static const unsigned char llc_oui_ipv6[] = { LLC, SNAP_ROUTED, ETHERTYPE_IPV6 };
+
+enum br2684_encaps {
+	e_vc = BR2684_ENCAPS_VC,
+	e_llc = BR2684_ENCAPS_LLC,
+};
+
+struct br2684_vcc {
+	struct atm_vcc *atmvcc;
+	struct net_device *device;
+	/* keep old push, pop functions for chaining */
+	void (*old_push)(struct atm_vcc *vcc, struct sk_buff *skb);
+	void (*old_pop)(struct atm_vcc *vcc, struct sk_buff *skb);
+	void (*old_release_cb)(struct atm_vcc *vcc);
+	struct module *old_owner;
+	enum br2684_encaps encaps;
+	struct list_head brvccs;
+#ifdef CONFIG_ATM_BR2684_IPFILTER
+	struct br2684_filter filter;
+#endif /* CONFIG_ATM_BR2684_IPFILTER */
+	unsigned int copies_needed, copies_failed;
+	atomic_t qspace;
+};
+
+struct br2684_dev {
+	struct net_device *net_dev;
+	struct list_head br2684_devs;
+	int number;
+	struct list_head brvccs;	/* one device <=> one vcc (before xmas) */
+	int mac_was_set;
+	enum br2684_payload payload;
+};
+
+/*
+ * This lock should be held for writing any time the list of devices or
+ * their attached vcc's could be altered.  It should be held for reading
+ * any time these are being queried.  Note that we sometimes need to
+ * do read-locking under interrupting context, so write locking must block
+ * the current CPU's interrupts.
+ */
+static DEFINE_RWLOCK(devs_lock);
+
+static LIST_HEAD(br2684_devs);
+
+static inline struct br2684_dev *BRPRIV(const struct net_device *net_dev)
+{
+	return netdev_priv(net_dev);
+}
+
+static inline struct net_device *list_entry_brdev(const struct list_head *le)
+{
+	return list_entry(le, struct br2684_dev, br2684_devs)->net_dev;
+}
+
+static inline struct br2684_vcc *BR2684_VCC(const struct atm_vcc *atmvcc)
+{
+	return (struct br2684_vcc *)(atmvcc->user_back);
+}
+
+static inline struct br2684_vcc *list_entry_brvcc(const struct list_head *le)
+{
+	return list_entry(le, struct br2684_vcc, brvccs);
+}
+
+/* Caller should hold read_lock(&devs_lock) */
+static struct net_device *br2684_find_dev(const struct br2684_if_spec *s)
+{
+	struct list_head *lh;
+	struct net_device *net_dev;
+	switch (s->method) {
+	case BR2684_FIND_BYNUM:
+		list_for_each(lh, &br2684_devs) {
+			net_dev = list_entry_brdev(lh);
+			if (BRPRIV(net_dev)->number == s->spec.devnum)
+				return net_dev;
+		}
+		break;
+	case BR2684_FIND_BYIFNAME:
+		list_for_each(lh, &br2684_devs) {
+			net_dev = list_entry_brdev(lh);
+			if (!strncmp(net_dev->name, s->spec.ifname, IFNAMSIZ))
+				return net_dev;
+		}
+		break;
+	}
+	return NULL;
+}
+
+static int atm_dev_event(struct notifier_block *this, unsigned long event,
+		 void *arg)
+{
+	struct atm_dev *atm_dev = arg;
+	struct list_head *lh;
+	struct net_device *net_dev;
+	struct br2684_vcc *brvcc;
+	struct atm_vcc *atm_vcc;
+	unsigned long flags;
+
+	pr_debug("event=%ld dev=%p\n", event, atm_dev);
+
+	read_lock_irqsave(&devs_lock, flags);
+	list_for_each(lh, &br2684_devs) {
+		net_dev = list_entry_brdev(lh);
+
+		list_for_each_entry(brvcc, &BRPRIV(net_dev)->brvccs, brvccs) {
+			atm_vcc = brvcc->atmvcc;
+			if (atm_vcc && brvcc->atmvcc->dev == atm_dev) {
+
+				if (atm_vcc->dev->signal == ATM_PHY_SIG_LOST)
+					netif_carrier_off(net_dev);
+				else
+					netif_carrier_on(net_dev);
+
+			}
+		}
+	}
+	read_unlock_irqrestore(&devs_lock, flags);
+
+	return NOTIFY_DONE;
+}
+
+static struct notifier_block atm_dev_notifier = {
+	.notifier_call = atm_dev_event,
+};
+
+/* chained vcc->pop function.  Check if we should wake the netif_queue */
+static void br2684_pop(struct atm_vcc *vcc, struct sk_buff *skb)
+{
+	struct br2684_vcc *brvcc = BR2684_VCC(vcc);
+
+	pr_debug("(vcc %p ; net_dev %p )\n", vcc, brvcc->device);
+	brvcc->old_pop(vcc, skb);
+
+	/* If the queue space just went up from zero, wake */
+	if (atomic_inc_return(&brvcc->qspace) == 1)
+		netif_wake_queue(brvcc->device);
+}
+
+/*
+ * Send a packet out a particular vcc.  Not to useful right now, but paves
+ * the way for multiple vcc's per itf.  Returns true if we can send,
+ * otherwise false
+ */
+static int br2684_xmit_vcc(struct sk_buff *skb, struct net_device *dev,
+			   struct br2684_vcc *brvcc)
+{
+	struct br2684_dev *brdev = BRPRIV(dev);
+	struct atm_vcc *atmvcc;
+	int minheadroom = (brvcc->encaps == e_llc) ?
+		((brdev->payload == p_bridged) ?
+			sizeof(llc_oui_pid_pad) : sizeof(llc_oui_ipv4)) :
+		((brdev->payload == p_bridged) ? BR2684_PAD_LEN : 0);
+
+	if (skb_headroom(skb) < minheadroom) {
+		struct sk_buff *skb2 = skb_realloc_headroom(skb, minheadroom);
+		brvcc->copies_needed++;
+		dev_kfree_skb(skb);
+		if (skb2 == NULL) {
+			brvcc->copies_failed++;
+			return 0;
+		}
+		skb = skb2;
+	}
+
+	if (brvcc->encaps == e_llc) {
+		if (brdev->payload == p_bridged) {
+			skb_push(skb, sizeof(llc_oui_pid_pad));
+			skb_copy_to_linear_data(skb, llc_oui_pid_pad,
+						sizeof(llc_oui_pid_pad));
+		} else if (brdev->payload == p_routed) {
+			unsigned short prot = ntohs(skb->protocol);
+
+			skb_push(skb, sizeof(llc_oui_ipv4));
+			switch (prot) {
+			case ETH_P_IP:
+				skb_copy_to_linear_data(skb, llc_oui_ipv4,
+							sizeof(llc_oui_ipv4));
+				break;
+			case ETH_P_IPV6:
+				skb_copy_to_linear_data(skb, llc_oui_ipv6,
+							sizeof(llc_oui_ipv6));
+				break;
+			default:
+				dev_kfree_skb(skb);
+				return 0;
+			}
+		}
+	} else { /* e_vc */
+		if (brdev->payload == p_bridged) {
+			skb_push(skb, 2);
+			memset(skb->data, 0, 2);
+		}
+	}
+	skb_debug(skb);
+
+	ATM_SKB(skb)->vcc = atmvcc = brvcc->atmvcc;
+	pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n", skb, atmvcc, atmvcc->dev);
+	atm_account_tx(atmvcc, skb);
+	dev->stats.tx_packets++;
+	dev->stats.tx_bytes += skb->len;
+
+	if (atomic_dec_return(&brvcc->qspace) < 1) {
+		/* No more please! */
+		netif_stop_queue(brvcc->device);
+		/* We might have raced with br2684_pop() */
+		if (unlikely(atomic_read(&brvcc->qspace) > 0))
+			netif_wake_queue(brvcc->device);
+	}
+
+	/* If this fails immediately, the skb will be freed and br2684_pop()
+	   will wake the queue if appropriate. Just return an error so that
+	   the stats are updated correctly */
+	return !atmvcc->send(atmvcc, skb);
+}
+
+static void br2684_release_cb(struct atm_vcc *atmvcc)
+{
+	struct br2684_vcc *brvcc = BR2684_VCC(atmvcc);
+
+	if (atomic_read(&brvcc->qspace) > 0)
+		netif_wake_queue(brvcc->device);
+
+	if (brvcc->old_release_cb)
+		brvcc->old_release_cb(atmvcc);
+}
+
+static inline struct br2684_vcc *pick_outgoing_vcc(const struct sk_buff *skb,
+						   const struct br2684_dev *brdev)
+{
+	return list_empty(&brdev->brvccs) ? NULL : list_entry_brvcc(brdev->brvccs.next);	/* 1 vcc/dev right now */
+}
+
+static netdev_tx_t br2684_start_xmit(struct sk_buff *skb,
+				     struct net_device *dev)
+{
+	struct br2684_dev *brdev = BRPRIV(dev);
+	struct br2684_vcc *brvcc;
+	struct atm_vcc *atmvcc;
+	netdev_tx_t ret = NETDEV_TX_OK;
+
+	pr_debug("skb_dst(skb)=%p\n", skb_dst(skb));
+	read_lock(&devs_lock);
+	brvcc = pick_outgoing_vcc(skb, brdev);
+	if (brvcc == NULL) {
+		pr_debug("no vcc attached to dev %s\n", dev->name);
+		dev->stats.tx_errors++;
+		dev->stats.tx_carrier_errors++;
+		/* netif_stop_queue(dev); */
+		dev_kfree_skb(skb);
+		goto out_devs;
+	}
+	atmvcc = brvcc->atmvcc;
+
+	bh_lock_sock(sk_atm(atmvcc));
+
+	if (test_bit(ATM_VF_CLOSE, &atmvcc->flags) ||
+	    !test_bit(ATM_VF_READY, &atmvcc->flags)) {
+		dev->stats.tx_dropped++;
+		dev_kfree_skb(skb);
+		goto out;
+	}
+
+	if (sock_owned_by_user(sk_atm(atmvcc))) {
+		netif_stop_queue(brvcc->device);
+		ret = NETDEV_TX_BUSY;
+		goto out;
+	}
+
+	if (!br2684_xmit_vcc(skb, dev, brvcc)) {
+		/*
+		 * We should probably use netif_*_queue() here, but that
+		 * involves added complication.  We need to walk before
+		 * we can run.
+		 *
+		 * Don't free here! this pointer might be no longer valid!
+		 */
+		dev->stats.tx_errors++;
+		dev->stats.tx_fifo_errors++;
+	}
+ out:
+	bh_unlock_sock(sk_atm(atmvcc));
+ out_devs:
+	read_unlock(&devs_lock);
+	return ret;
+}
+
+/*
+ * We remember when the MAC gets set, so we don't override it later with
+ * the ESI of the ATM card of the first VC
+ */
+static int br2684_mac_addr(struct net_device *dev, void *p)
+{
+	int err = eth_mac_addr(dev, p);
+	if (!err)
+		BRPRIV(dev)->mac_was_set = 1;
+	return err;
+}
+
+#ifdef CONFIG_ATM_BR2684_IPFILTER
+/* this IOCTL is experimental. */
+static int br2684_setfilt(struct atm_vcc *atmvcc, void __user * arg)
+{
+	struct br2684_vcc *brvcc;
+	struct br2684_filter_set fs;
+
+	if (copy_from_user(&fs, arg, sizeof fs))
+		return -EFAULT;
+	if (fs.ifspec.method != BR2684_FIND_BYNOTHING) {
+		/*
+		 * This is really a per-vcc thing, but we can also search
+		 * by device.
+		 */
+		struct br2684_dev *brdev;
+		read_lock(&devs_lock);
+		brdev = BRPRIV(br2684_find_dev(&fs.ifspec));
+		if (brdev == NULL || list_empty(&brdev->brvccs) ||
+		    brdev->brvccs.next != brdev->brvccs.prev)	/* >1 VCC */
+			brvcc = NULL;
+		else
+			brvcc = list_entry_brvcc(brdev->brvccs.next);
+		read_unlock(&devs_lock);
+		if (brvcc == NULL)
+			return -ESRCH;
+	} else
+		brvcc = BR2684_VCC(atmvcc);
+	memcpy(&brvcc->filter, &fs.filter, sizeof(brvcc->filter));
+	return 0;
+}
+
+/* Returns 1 if packet should be dropped */
+static inline int
+packet_fails_filter(__be16 type, struct br2684_vcc *brvcc, struct sk_buff *skb)
+{
+	if (brvcc->filter.netmask == 0)
+		return 0;	/* no filter in place */
+	if (type == htons(ETH_P_IP) &&
+	    (((struct iphdr *)(skb->data))->daddr & brvcc->filter.
+	     netmask) == brvcc->filter.prefix)
+		return 0;
+	if (type == htons(ETH_P_ARP))
+		return 0;
+	/*
+	 * TODO: we should probably filter ARPs too.. don't want to have
+	 * them returning values that don't make sense, or is that ok?
+	 */
+	return 1;		/* drop */
+}
+#endif /* CONFIG_ATM_BR2684_IPFILTER */
+
+static void br2684_close_vcc(struct br2684_vcc *brvcc)
+{
+	pr_debug("removing VCC %p from dev %p\n", brvcc, brvcc->device);
+	write_lock_irq(&devs_lock);
+	list_del(&brvcc->brvccs);
+	write_unlock_irq(&devs_lock);
+	brvcc->atmvcc->user_back = NULL;	/* what about vcc->recvq ??? */
+	brvcc->atmvcc->release_cb = brvcc->old_release_cb;
+	brvcc->old_push(brvcc->atmvcc, NULL);	/* pass on the bad news */
+	module_put(brvcc->old_owner);
+	kfree(brvcc);
+}
+
+/* when AAL5 PDU comes in: */
+static void br2684_push(struct atm_vcc *atmvcc, struct sk_buff *skb)
+{
+	struct br2684_vcc *brvcc = BR2684_VCC(atmvcc);
+	struct net_device *net_dev = brvcc->device;
+	struct br2684_dev *brdev = BRPRIV(net_dev);
+
+	pr_debug("\n");
+
+	if (unlikely(skb == NULL)) {
+		/* skb==NULL means VCC is being destroyed */
+		br2684_close_vcc(brvcc);
+		if (list_empty(&brdev->brvccs)) {
+			write_lock_irq(&devs_lock);
+			list_del(&brdev->br2684_devs);
+			write_unlock_irq(&devs_lock);
+			unregister_netdev(net_dev);
+			free_netdev(net_dev);
+		}
+		return;
+	}
+
+	skb_debug(skb);
+	atm_return(atmvcc, skb->truesize);
+	pr_debug("skb from brdev %p\n", brdev);
+	if (brvcc->encaps == e_llc) {
+
+		if (skb->len > 7 && skb->data[7] == 0x01)
+			__skb_trim(skb, skb->len - 4);
+
+		/* accept packets that have "ipv[46]" in the snap header */
+		if ((skb->len >= (sizeof(llc_oui_ipv4))) &&
+		    (memcmp(skb->data, llc_oui_ipv4,
+			    sizeof(llc_oui_ipv4) - BR2684_ETHERTYPE_LEN) == 0)) {
+			if (memcmp(skb->data + 6, ethertype_ipv6,
+				   sizeof(ethertype_ipv6)) == 0)
+				skb->protocol = htons(ETH_P_IPV6);
+			else if (memcmp(skb->data + 6, ethertype_ipv4,
+					sizeof(ethertype_ipv4)) == 0)
+				skb->protocol = htons(ETH_P_IP);
+			else
+				goto error;
+			skb_pull(skb, sizeof(llc_oui_ipv4));
+			skb_reset_network_header(skb);
+			skb->pkt_type = PACKET_HOST;
+		/*
+		 * Let us waste some time for checking the encapsulation.
+		 * Note, that only 7 char is checked so frames with a valid FCS
+		 * are also accepted (but FCS is not checked of course).
+		 */
+		} else if ((skb->len >= sizeof(llc_oui_pid_pad)) &&
+			   (memcmp(skb->data, llc_oui_pid_pad, 7) == 0)) {
+			skb_pull(skb, sizeof(llc_oui_pid_pad));
+			skb->protocol = eth_type_trans(skb, net_dev);
+		} else
+			goto error;
+
+	} else { /* e_vc */
+		if (brdev->payload == p_routed) {
+			struct iphdr *iph;
+
+			skb_reset_network_header(skb);
+			iph = ip_hdr(skb);
+			if (iph->version == 4)
+				skb->protocol = htons(ETH_P_IP);
+			else if (iph->version == 6)
+				skb->protocol = htons(ETH_P_IPV6);
+			else
+				goto error;
+			skb->pkt_type = PACKET_HOST;
+		} else { /* p_bridged */
+			/* first 2 chars should be 0 */
+			if (memcmp(skb->data, pad, BR2684_PAD_LEN) != 0)
+				goto error;
+			skb_pull(skb, BR2684_PAD_LEN);
+			skb->protocol = eth_type_trans(skb, net_dev);
+		}
+	}
+
+#ifdef CONFIG_ATM_BR2684_IPFILTER
+	if (unlikely(packet_fails_filter(skb->protocol, brvcc, skb)))
+		goto dropped;
+#endif /* CONFIG_ATM_BR2684_IPFILTER */
+	skb->dev = net_dev;
+	ATM_SKB(skb)->vcc = atmvcc;	/* needed ? */
+	pr_debug("received packet's protocol: %x\n", ntohs(skb->protocol));
+	skb_debug(skb);
+	/* sigh, interface is down? */
+	if (unlikely(!(net_dev->flags & IFF_UP)))
+		goto dropped;
+	net_dev->stats.rx_packets++;
+	net_dev->stats.rx_bytes += skb->len;
+	memset(ATM_SKB(skb), 0, sizeof(struct atm_skb_data));
+	netif_rx(skb);
+	return;
+
+dropped:
+	net_dev->stats.rx_dropped++;
+	goto free_skb;
+error:
+	net_dev->stats.rx_errors++;
+free_skb:
+	dev_kfree_skb(skb);
+}
+
+/*
+ * Assign a vcc to a dev
+ * Note: we do not have explicit unassign, but look at _push()
+ */
+static int br2684_regvcc(struct atm_vcc *atmvcc, void __user * arg)
+{
+	struct br2684_vcc *brvcc;
+	struct br2684_dev *brdev;
+	struct net_device *net_dev;
+	struct atm_backend_br2684 be;
+	int err;
+
+	if (copy_from_user(&be, arg, sizeof be))
+		return -EFAULT;
+	brvcc = kzalloc_obj(struct br2684_vcc);
+	if (!brvcc)
+		return -ENOMEM;
+	/*
+	 * Allow two packets in the ATM queue. One actually being sent, and one
+	 * for the ATM 'TX done' handler to send. It shouldn't take long to get
+	 * the next one from the netdev queue, when we need it. More than that
+	 * would be bufferbloat.
+	 */
+	atomic_set(&brvcc->qspace, 2);
+	write_lock_irq(&devs_lock);
+	net_dev = br2684_find_dev(&be.ifspec);
+	if (net_dev == NULL) {
+		pr_err("tried to attach to non-existent device\n");
+		err = -ENXIO;
+		goto error;
+	}
+	brdev = BRPRIV(net_dev);
+	if (atmvcc->push == NULL) {
+		err = -EBADFD;
+		goto error;
+	}
+	if (!list_empty(&brdev->brvccs)) {
+		/* Only 1 VCC/dev right now */
+		err = -EEXIST;
+		goto error;
+	}
+	if (be.fcs_in != BR2684_FCSIN_NO ||
+	    be.fcs_out != BR2684_FCSOUT_NO ||
+	    be.fcs_auto || be.has_vpiid || be.send_padding ||
+	    (be.encaps != BR2684_ENCAPS_VC &&
+	     be.encaps != BR2684_ENCAPS_LLC) ||
+	    be.min_size != 0) {
+		err = -EINVAL;
+		goto error;
+	}
+	pr_debug("vcc=%p, encaps=%d, brvcc=%p\n", atmvcc, be.encaps, brvcc);
+	if (list_empty(&brdev->brvccs) && !brdev->mac_was_set) {
+		unsigned char *esi = atmvcc->dev->esi;
+		const u8 one = 1;
+
+		if (esi[0] | esi[1] | esi[2] | esi[3] | esi[4] | esi[5])
+			dev_addr_set(net_dev, esi);
+		else
+			dev_addr_mod(net_dev, 2, &one, 1);
+	}
+	list_add(&brvcc->brvccs, &brdev->brvccs);
+	write_unlock_irq(&devs_lock);
+	brvcc->device = net_dev;
+	brvcc->atmvcc = atmvcc;
+	atmvcc->user_back = brvcc;
+	brvcc->encaps = (enum br2684_encaps)be.encaps;
+	brvcc->old_push = atmvcc->push;
+	brvcc->old_pop = atmvcc->pop;
+	brvcc->old_release_cb = atmvcc->release_cb;
+	brvcc->old_owner = atmvcc->owner;
+	barrier();
+	atmvcc->push = br2684_push;
+	atmvcc->pop = br2684_pop;
+	atmvcc->release_cb = br2684_release_cb;
+	atmvcc->owner = THIS_MODULE;
+
+	/* initialize netdev carrier state */
+	if (atmvcc->dev->signal == ATM_PHY_SIG_LOST)
+		netif_carrier_off(net_dev);
+	else
+		netif_carrier_on(net_dev);
+
+	__module_get(THIS_MODULE);
+
+	/* re-process everything received between connection setup and
+	   backend setup */
+	vcc_process_recv_queue(atmvcc);
+	return 0;
+
+error:
+	write_unlock_irq(&devs_lock);
+	kfree(brvcc);
+	return err;
+}
+
+static const struct net_device_ops br2684_netdev_ops = {
+	.ndo_start_xmit 	= br2684_start_xmit,
+	.ndo_set_mac_address	= br2684_mac_addr,
+	.ndo_validate_addr	= eth_validate_addr,
+};
+
+static const struct net_device_ops br2684_netdev_ops_routed = {
+	.ndo_start_xmit 	= br2684_start_xmit,
+	.ndo_set_mac_address	= br2684_mac_addr,
+};
+
+static void br2684_setup(struct net_device *netdev)
+{
+	struct br2684_dev *brdev = BRPRIV(netdev);
+
+	ether_setup(netdev);
+	netdev->hard_header_len += sizeof(llc_oui_pid_pad); /* worst case */
+	brdev->net_dev = netdev;
+
+	netdev->netdev_ops = &br2684_netdev_ops;
+
+	INIT_LIST_HEAD(&brdev->brvccs);
+}
+
+static void br2684_setup_routed(struct net_device *netdev)
+{
+	struct br2684_dev *brdev = BRPRIV(netdev);
+
+	brdev->net_dev = netdev;
+	netdev->hard_header_len = sizeof(llc_oui_ipv4); /* worst case */
+	netdev->netdev_ops = &br2684_netdev_ops_routed;
+	netdev->addr_len = 0;
+	netdev->mtu = ETH_DATA_LEN;
+	netdev->min_mtu = 0;
+	netdev->max_mtu = ETH_MAX_MTU;
+	netdev->type = ARPHRD_PPP;
+	netdev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
+	netdev->tx_queue_len = 100;
+	INIT_LIST_HEAD(&brdev->brvccs);
+}
+
+static int br2684_create(void __user *arg)
+{
+	int err;
+	struct net_device *netdev;
+	struct br2684_dev *brdev;
+	struct atm_newif_br2684 ni;
+	enum br2684_payload payload;
+
+	pr_debug("\n");
+
+	if (copy_from_user(&ni, arg, sizeof ni))
+		return -EFAULT;
+
+	if (ni.media & BR2684_FLAG_ROUTED)
+		payload = p_routed;
+	else
+		payload = p_bridged;
+	ni.media &= 0xffff;	/* strip flags */
+
+	if (ni.media != BR2684_MEDIA_ETHERNET || ni.mtu != 1500)
+		return -EINVAL;
+
+	netdev = alloc_netdev(sizeof(struct br2684_dev),
+			      ni.ifname[0] ? ni.ifname : "nas%d",
+			      NET_NAME_UNKNOWN,
+			      (payload == p_routed) ? br2684_setup_routed : br2684_setup);
+	if (!netdev)
+		return -ENOMEM;
+
+	brdev = BRPRIV(netdev);
+
+	pr_debug("registered netdev %s\n", netdev->name);
+	/* open, stop, do_ioctl ? */
+	err = register_netdev(netdev);
+	if (err < 0) {
+		pr_err("register_netdev failed\n");
+		free_netdev(netdev);
+		return err;
+	}
+
+	write_lock_irq(&devs_lock);
+
+	brdev->payload = payload;
+
+	if (list_empty(&br2684_devs)) {
+		/* 1st br2684 device */
+		brdev->number = 1;
+	} else
+		brdev->number = BRPRIV(list_entry_brdev(br2684_devs.prev))->number + 1;
+
+	list_add_tail(&brdev->br2684_devs, &br2684_devs);
+	write_unlock_irq(&devs_lock);
+	return 0;
+}
+
+/*
+ * This handles ioctls actually performed on our vcc - we must return
+ * -ENOIOCTLCMD for any unrecognized ioctl
+ */
+static int br2684_ioctl(struct socket *sock, unsigned int cmd,
+			unsigned long arg)
+{
+	struct atm_vcc *atmvcc = ATM_SD(sock);
+	void __user *argp = (void __user *)arg;
+	atm_backend_t b;
+
+	int err;
+	switch (cmd) {
+	case ATM_SETBACKEND:
+	case ATM_NEWBACKENDIF:
+		err = get_user(b, (atm_backend_t __user *) argp);
+		if (err)
+			return -EFAULT;
+		if (b != ATM_BACKEND_BR2684)
+			return -ENOIOCTLCMD;
+		if (!capable(CAP_NET_ADMIN))
+			return -EPERM;
+		if (cmd == ATM_SETBACKEND) {
+			if (sock->state != SS_CONNECTED)
+				return -EINVAL;
+			return br2684_regvcc(atmvcc, argp);
+		} else {
+			return br2684_create(argp);
+		}
+#ifdef CONFIG_ATM_BR2684_IPFILTER
+	case BR2684_SETFILT:
+		if (atmvcc->push != br2684_push)
+			return -ENOIOCTLCMD;
+		if (!capable(CAP_NET_ADMIN))
+			return -EPERM;
+		err = br2684_setfilt(atmvcc, argp);
+
+		return err;
+#endif /* CONFIG_ATM_BR2684_IPFILTER */
+	}
+	return -ENOIOCTLCMD;
+}
+
+static struct atm_ioctl br2684_ioctl_ops = {
+	.owner = THIS_MODULE,
+	.ioctl = br2684_ioctl,
+};
+
+#ifdef CONFIG_PROC_FS
+static void *br2684_seq_start(struct seq_file *seq, loff_t * pos)
+	__acquires(devs_lock)
+{
+	read_lock(&devs_lock);
+	return seq_list_start(&br2684_devs, *pos);
+}
+
+static void *br2684_seq_next(struct seq_file *seq, void *v, loff_t * pos)
+{
+	return seq_list_next(v, &br2684_devs, pos);
+}
+
+static void br2684_seq_stop(struct seq_file *seq, void *v)
+	__releases(devs_lock)
+{
+	read_unlock(&devs_lock);
+}
+
+static int br2684_seq_show(struct seq_file *seq, void *v)
+{
+	const struct br2684_dev *brdev = list_entry(v, struct br2684_dev,
+						    br2684_devs);
+	const struct net_device *net_dev = brdev->net_dev;
+	const struct br2684_vcc *brvcc;
+
+	seq_printf(seq, "dev %.16s: num=%d, mac=%pM (%s)\n",
+		   net_dev->name,
+		   brdev->number,
+		   net_dev->dev_addr,
+		   brdev->mac_was_set ? "set" : "auto");
+
+	list_for_each_entry(brvcc, &brdev->brvccs, brvccs) {
+		seq_printf(seq, "  vcc %d.%d.%d: encaps=%s payload=%s"
+			   ", failed copies %u/%u"
+			   "\n", brvcc->atmvcc->dev->number,
+			   brvcc->atmvcc->vpi, brvcc->atmvcc->vci,
+			   (brvcc->encaps == e_llc) ? "LLC" : "VC",
+			   (brdev->payload == p_bridged) ? "bridged" : "routed",
+			   brvcc->copies_failed, brvcc->copies_needed);
+#ifdef CONFIG_ATM_BR2684_IPFILTER
+		if (brvcc->filter.netmask != 0)
+			seq_printf(seq, "    filter=%pI4/%pI4\n",
+				   &brvcc->filter.prefix,
+				   &brvcc->filter.netmask);
+#endif /* CONFIG_ATM_BR2684_IPFILTER */
+	}
+	return 0;
+}
+
+static const struct seq_operations br2684_seq_ops = {
+	.start = br2684_seq_start,
+	.next = br2684_seq_next,
+	.stop = br2684_seq_stop,
+	.show = br2684_seq_show,
+};
+
+extern struct proc_dir_entry *atm_proc_root;	/* from proc.c */
+#endif /* CONFIG_PROC_FS */
+
+static int __init br2684_init(void)
+{
+#ifdef CONFIG_PROC_FS
+	struct proc_dir_entry *p;
+	p = proc_create_seq("br2684", 0, atm_proc_root, &br2684_seq_ops);
+	if (p == NULL)
+		return -ENOMEM;
+#endif
+	register_atm_ioctl(&br2684_ioctl_ops);
+	register_atmdevice_notifier(&atm_dev_notifier);
+	return 0;
+}
+
+static void __exit br2684_exit(void)
+{
+	struct net_device *net_dev;
+	struct br2684_dev *brdev;
+	struct br2684_vcc *brvcc;
+	deregister_atm_ioctl(&br2684_ioctl_ops);
+
+#ifdef CONFIG_PROC_FS
+	remove_proc_entry("br2684", atm_proc_root);
+#endif
+
+
+	unregister_atmdevice_notifier(&atm_dev_notifier);
+
+	while (!list_empty(&br2684_devs)) {
+		net_dev = list_entry_brdev(br2684_devs.next);
+		brdev = BRPRIV(net_dev);
+		while (!list_empty(&brdev->brvccs)) {
+			brvcc = list_entry_brvcc(brdev->brvccs.next);
+			br2684_close_vcc(brvcc);
+		}
+
+		list_del(&brdev->br2684_devs);
+		unregister_netdev(net_dev);
+		free_netdev(net_dev);
+	}
+}
+
+module_init(br2684_init);
+module_exit(br2684_exit);
+
+MODULE_AUTHOR("Marcell GAL");
+MODULE_DESCRIPTION("RFC2684 bridged protocols over ATM/AAL5");
+MODULE_LICENSE("GPL");
diff --git a/net/atm/common.c b/net/atm/common.c
new file mode 100644
index 000000000..81195727f
--- /dev/null
+++ b/net/atm/common.c
@@ -0,0 +1,857 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* net/atm/common.c - ATM sockets (common part for PVC and SVC) */
+
+/* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
+
+#include <linux/module.h>
+#include <linux/kmod.h>
+#include <linux/net.h>		/* struct socket, struct proto_ops */
+#include <linux/atm.h>		/* ATM stuff */
+#include <linux/atmdev.h>
+#include <linux/socket.h>	/* SOL_SOCKET */
+#include <linux/errno.h>	/* error codes */
+#include <linux/capability.h>
+#include <linux/mm.h>
+#include <linux/sched/signal.h>
+#include <linux/time64.h>	/* 64-bit time for seconds */
+#include <linux/skbuff.h>
+#include <linux/bitops.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <net/sock.h>		/* struct sock */
+#include <linux/uaccess.h>
+#include <linux/poll.h>
+#include <linux/uio.h>
+
+#include <linux/atomic.h>
+
+#include "resources.h"		/* atm_find_dev */
+#include "common.h"		/* prototypes */
+#include "protocols.h"		/* atm_init_<transport> */
+
+struct hlist_head vcc_hash[VCC_HTABLE_SIZE];
+EXPORT_SYMBOL(vcc_hash);
+
+DEFINE_RWLOCK(vcc_sklist_lock);
+EXPORT_SYMBOL(vcc_sklist_lock);
+
+static ATOMIC_NOTIFIER_HEAD(atm_dev_notify_chain);
+
+static void __vcc_insert_socket(struct sock *sk)
+{
+	struct atm_vcc *vcc = atm_sk(sk);
+	struct hlist_head *head = &vcc_hash[vcc->vci & (VCC_HTABLE_SIZE - 1)];
+	sk->sk_hash = vcc->vci & (VCC_HTABLE_SIZE - 1);
+	sk_add_node(sk, head);
+}
+
+void vcc_insert_socket(struct sock *sk)
+{
+	write_lock_irq(&vcc_sklist_lock);
+	__vcc_insert_socket(sk);
+	write_unlock_irq(&vcc_sklist_lock);
+}
+EXPORT_SYMBOL(vcc_insert_socket);
+
+static void vcc_remove_socket(struct sock *sk)
+{
+	write_lock_irq(&vcc_sklist_lock);
+	sk_del_node_init(sk);
+	write_unlock_irq(&vcc_sklist_lock);
+}
+
+static bool vcc_tx_ready(struct atm_vcc *vcc, unsigned int size)
+{
+	struct sock *sk = sk_atm(vcc);
+
+	if (sk_wmem_alloc_get(sk) && !atm_may_send(vcc, size)) {
+		pr_debug("Sorry: wmem_alloc = %d, size = %d, sndbuf = %d\n",
+			 sk_wmem_alloc_get(sk), size, sk->sk_sndbuf);
+		return false;
+	}
+	return true;
+}
+
+static void vcc_sock_destruct(struct sock *sk)
+{
+	if (atomic_read(&sk->sk_rmem_alloc))
+		printk(KERN_DEBUG "%s: rmem leakage (%d bytes) detected.\n",
+		       __func__, atomic_read(&sk->sk_rmem_alloc));
+
+	if (refcount_read(&sk->sk_wmem_alloc))
+		printk(KERN_DEBUG "%s: wmem leakage (%d bytes) detected.\n",
+		       __func__, refcount_read(&sk->sk_wmem_alloc));
+}
+
+static void vcc_def_wakeup(struct sock *sk)
+{
+	struct socket_wq *wq;
+
+	rcu_read_lock();
+	wq = rcu_dereference(sk->sk_wq);
+	if (skwq_has_sleeper(wq))
+		wake_up(&wq->wait);
+	rcu_read_unlock();
+}
+
+static inline int vcc_writable(struct sock *sk)
+{
+	struct atm_vcc *vcc = atm_sk(sk);
+
+	return (vcc->qos.txtp.max_sdu +
+		refcount_read(&sk->sk_wmem_alloc)) <= sk->sk_sndbuf;
+}
+
+static void vcc_write_space(struct sock *sk)
+{
+	struct socket_wq *wq;
+
+	rcu_read_lock();
+
+	if (vcc_writable(sk)) {
+		wq = rcu_dereference(sk->sk_wq);
+		if (skwq_has_sleeper(wq))
+			wake_up_interruptible(&wq->wait);
+
+		sk_wake_async_rcu(sk, SOCK_WAKE_SPACE, POLL_OUT);
+	}
+
+	rcu_read_unlock();
+}
+
+static void vcc_release_cb(struct sock *sk)
+{
+	struct atm_vcc *vcc = atm_sk(sk);
+
+	if (vcc->release_cb)
+		vcc->release_cb(vcc);
+}
+
+static struct proto vcc_proto = {
+	.name	  = "VCC",
+	.owner	  = THIS_MODULE,
+	.obj_size = sizeof(struct atm_vcc),
+	.release_cb = vcc_release_cb,
+};
+
+int vcc_create(struct net *net, struct socket *sock, int protocol, int family, int kern)
+{
+	struct sock *sk;
+	struct atm_vcc *vcc;
+
+	sock->sk = NULL;
+	if (sock->type == SOCK_STREAM)
+		return -EINVAL;
+	sk = sk_alloc(net, family, GFP_KERNEL, &vcc_proto, kern);
+	if (!sk)
+		return -ENOMEM;
+	sock_init_data(sock, sk);
+	sk->sk_state_change = vcc_def_wakeup;
+	sk->sk_write_space = vcc_write_space;
+
+	vcc = atm_sk(sk);
+	vcc->dev = NULL;
+	vcc->qos.txtp.max_sdu = 1 << 16; /* for meta VCs */
+	refcount_set(&sk->sk_wmem_alloc, SK_WMEM_ALLOC_BIAS);
+	atomic_set(&sk->sk_rmem_alloc, 0);
+	vcc->push = NULL;
+	vcc->pop = NULL;
+	vcc->owner = NULL;
+	vcc->release_cb = NULL;
+	vcc->vpi = vcc->vci = 0; /* no VCI/VPI yet */
+	vcc->atm_options = vcc->aal_options = 0;
+	sk->sk_destruct = vcc_sock_destruct;
+	return 0;
+}
+
+static void vcc_destroy_socket(struct sock *sk)
+{
+	struct atm_vcc *vcc = atm_sk(sk);
+	struct sk_buff *skb;
+
+	set_bit(ATM_VF_CLOSE, &vcc->flags);
+	clear_bit(ATM_VF_READY, &vcc->flags);
+	if (vcc->dev && vcc->dev->ops->close)
+		vcc->dev->ops->close(vcc);
+	if (vcc->push)
+		vcc->push(vcc, NULL); /* atmarpd has no push */
+	module_put(vcc->owner);
+
+	while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
+		atm_return(vcc, skb->truesize);
+		kfree_skb(skb);
+	}
+
+	if (vcc->dev && vcc->dev->ops->owner) {
+		module_put(vcc->dev->ops->owner);
+		atm_dev_put(vcc->dev);
+	}
+
+	vcc_remove_socket(sk);
+}
+
+int vcc_release(struct socket *sock)
+{
+	struct sock *sk = sock->sk;
+
+	if (sk) {
+		lock_sock(sk);
+		vcc_destroy_socket(sock->sk);
+		release_sock(sk);
+		sock_put(sk);
+	}
+
+	return 0;
+}
+
+void vcc_release_async(struct atm_vcc *vcc, int reply)
+{
+	struct sock *sk = sk_atm(vcc);
+
+	set_bit(ATM_VF_CLOSE, &vcc->flags);
+	sk->sk_shutdown |= RCV_SHUTDOWN;
+	sk->sk_err = -reply;
+	sk->sk_state_change(sk);
+}
+EXPORT_SYMBOL(vcc_release_async);
+
+void vcc_process_recv_queue(struct atm_vcc *vcc)
+{
+	struct sk_buff_head queue, *rq;
+	struct sk_buff *skb, *tmp;
+	unsigned long flags;
+
+	__skb_queue_head_init(&queue);
+	rq = &sk_atm(vcc)->sk_receive_queue;
+
+	spin_lock_irqsave(&rq->lock, flags);
+	skb_queue_splice_init(rq, &queue);
+	spin_unlock_irqrestore(&rq->lock, flags);
+
+	skb_queue_walk_safe(&queue, skb, tmp) {
+		__skb_unlink(skb, &queue);
+		vcc->push(vcc, skb);
+	}
+}
+EXPORT_SYMBOL(vcc_process_recv_queue);
+
+void atm_dev_signal_change(struct atm_dev *dev, char signal)
+{
+	pr_debug("%s signal=%d dev=%p number=%d dev->signal=%d\n",
+		__func__, signal, dev, dev->number, dev->signal);
+
+	/* atm driver sending invalid signal */
+	WARN_ON(signal < ATM_PHY_SIG_LOST || signal > ATM_PHY_SIG_FOUND);
+
+	if (dev->signal == signal)
+		return; /* no change */
+
+	dev->signal = signal;
+
+	atomic_notifier_call_chain(&atm_dev_notify_chain, signal, dev);
+}
+EXPORT_SYMBOL(atm_dev_signal_change);
+
+void atm_dev_release_vccs(struct atm_dev *dev)
+{
+	int i;
+
+	write_lock_irq(&vcc_sklist_lock);
+	for (i = 0; i < VCC_HTABLE_SIZE; i++) {
+		struct hlist_head *head = &vcc_hash[i];
+		struct hlist_node *tmp;
+		struct sock *s;
+		struct atm_vcc *vcc;
+
+		sk_for_each_safe(s, tmp, head) {
+			vcc = atm_sk(s);
+			if (vcc->dev == dev) {
+				vcc_release_async(vcc, -EPIPE);
+				sk_del_node_init(s);
+			}
+		}
+	}
+	write_unlock_irq(&vcc_sklist_lock);
+}
+EXPORT_SYMBOL(atm_dev_release_vccs);
+
+static int adjust_tp(struct atm_trafprm *tp, unsigned char aal)
+{
+	int max_sdu;
+
+	if (!tp->traffic_class)
+		return 0;
+	switch (aal) {
+	case ATM_AAL0:
+		max_sdu = ATM_CELL_SIZE-1;
+		break;
+	default:
+		pr_warn("AAL problems ... (%d)\n", aal);
+		fallthrough;
+	case ATM_AAL5:
+		max_sdu = ATM_MAX_AAL5_PDU;
+	}
+	if (!tp->max_sdu)
+		tp->max_sdu = max_sdu;
+	else if (tp->max_sdu > max_sdu)
+		return -EINVAL;
+	if (!tp->max_cdv)
+		tp->max_cdv = ATM_MAX_CDV;
+	return 0;
+}
+
+static int check_ci(const struct atm_vcc *vcc, short vpi, int vci)
+{
+	struct hlist_head *head = &vcc_hash[vci & (VCC_HTABLE_SIZE - 1)];
+	struct sock *s;
+	struct atm_vcc *walk;
+
+	sk_for_each(s, head) {
+		walk = atm_sk(s);
+		if (walk->dev != vcc->dev)
+			continue;
+		if (test_bit(ATM_VF_ADDR, &walk->flags) && walk->vpi == vpi &&
+		    walk->vci == vci && ((walk->qos.txtp.traffic_class !=
+		    ATM_NONE && vcc->qos.txtp.traffic_class != ATM_NONE) ||
+		    (walk->qos.rxtp.traffic_class != ATM_NONE &&
+		    vcc->qos.rxtp.traffic_class != ATM_NONE)))
+			return -EADDRINUSE;
+	}
+
+	/* allow VCCs with same VPI/VCI iff they don't collide on
+	   TX/RX (but we may refuse such sharing for other reasons,
+	   e.g. if protocol requires to have both channels) */
+
+	return 0;
+}
+
+static int find_ci(const struct atm_vcc *vcc, short *vpi, int *vci)
+{
+	static short p;        /* poor man's per-device cache */
+	static int c;
+	short old_p;
+	int old_c;
+	int err;
+
+	if (*vpi != ATM_VPI_ANY && *vci != ATM_VCI_ANY) {
+		err = check_ci(vcc, *vpi, *vci);
+		return err;
+	}
+	/* last scan may have left values out of bounds for current device */
+	if (*vpi != ATM_VPI_ANY)
+		p = *vpi;
+	else if (p >= 1 << vcc->dev->ci_range.vpi_bits)
+		p = 0;
+	if (*vci != ATM_VCI_ANY)
+		c = *vci;
+	else if (c < ATM_NOT_RSV_VCI || c >= 1 << vcc->dev->ci_range.vci_bits)
+			c = ATM_NOT_RSV_VCI;
+	old_p = p;
+	old_c = c;
+	do {
+		if (!check_ci(vcc, p, c)) {
+			*vpi = p;
+			*vci = c;
+			return 0;
+		}
+		if (*vci == ATM_VCI_ANY) {
+			c++;
+			if (c >= 1 << vcc->dev->ci_range.vci_bits)
+				c = ATM_NOT_RSV_VCI;
+		}
+		if ((c == ATM_NOT_RSV_VCI || *vci != ATM_VCI_ANY) &&
+		    *vpi == ATM_VPI_ANY) {
+			p++;
+			if (p >= 1 << vcc->dev->ci_range.vpi_bits)
+				p = 0;
+		}
+	} while (old_p != p || old_c != c);
+	return -EADDRINUSE;
+}
+
+static int __vcc_connect(struct atm_vcc *vcc, struct atm_dev *dev, short vpi,
+			 int vci)
+{
+	struct sock *sk = sk_atm(vcc);
+	int error;
+
+	if ((vpi != ATM_VPI_UNSPEC && vpi != ATM_VPI_ANY &&
+	    vpi >> dev->ci_range.vpi_bits) || (vci != ATM_VCI_UNSPEC &&
+	    vci != ATM_VCI_ANY && vci >> dev->ci_range.vci_bits))
+		return -EINVAL;
+	if (vci > 0 && vci < ATM_NOT_RSV_VCI && !capable(CAP_NET_BIND_SERVICE))
+		return -EPERM;
+	error = -ENODEV;
+	if (!try_module_get(dev->ops->owner))
+		return error;
+	vcc->dev = dev;
+	write_lock_irq(&vcc_sklist_lock);
+	if (test_bit(ATM_DF_REMOVED, &dev->flags) ||
+	    (error = find_ci(vcc, &vpi, &vci))) {
+		write_unlock_irq(&vcc_sklist_lock);
+		goto fail_module_put;
+	}
+	vcc->vpi = vpi;
+	vcc->vci = vci;
+	__vcc_insert_socket(sk);
+	write_unlock_irq(&vcc_sklist_lock);
+	switch (vcc->qos.aal) {
+	case ATM_AAL0:
+		error = atm_init_aal0(vcc);
+		vcc->stats = &dev->stats.aal0;
+		break;
+	case ATM_NO_AAL:
+		/* ATM_AAL5 is also used in the "0 for default" case */
+		vcc->qos.aal = ATM_AAL5;
+		fallthrough;
+	case ATM_AAL5:
+		error = atm_init_aal5(vcc);
+		vcc->stats = &dev->stats.aal5;
+		break;
+	default:
+		error = -EPROTOTYPE;
+	}
+	if (!error)
+		error = adjust_tp(&vcc->qos.txtp, vcc->qos.aal);
+	if (!error)
+		error = adjust_tp(&vcc->qos.rxtp, vcc->qos.aal);
+	if (error)
+		goto fail;
+	pr_debug("VCC %d.%d, AAL %d\n", vpi, vci, vcc->qos.aal);
+	pr_debug("  TX: %d, PCR %d..%d, SDU %d\n",
+		 vcc->qos.txtp.traffic_class,
+		 vcc->qos.txtp.min_pcr,
+		 vcc->qos.txtp.max_pcr,
+		 vcc->qos.txtp.max_sdu);
+	pr_debug("  RX: %d, PCR %d..%d, SDU %d\n",
+		 vcc->qos.rxtp.traffic_class,
+		 vcc->qos.rxtp.min_pcr,
+		 vcc->qos.rxtp.max_pcr,
+		 vcc->qos.rxtp.max_sdu);
+
+	if (dev->ops->open) {
+		error = dev->ops->open(vcc);
+		if (error)
+			goto fail;
+	}
+	return 0;
+
+fail:
+	vcc_remove_socket(sk);
+fail_module_put:
+	module_put(dev->ops->owner);
+	/* ensure we get dev module ref count correct */
+	vcc->dev = NULL;
+	return error;
+}
+
+int vcc_connect(struct socket *sock, int itf, short vpi, int vci)
+{
+	struct atm_dev *dev;
+	struct atm_vcc *vcc = ATM_SD(sock);
+	int error;
+
+	pr_debug("(vpi %d, vci %d)\n", vpi, vci);
+	if (sock->state == SS_CONNECTED)
+		return -EISCONN;
+	if (sock->state != SS_UNCONNECTED)
+		return -EINVAL;
+	if (!(vpi || vci))
+		return -EINVAL;
+
+	if (vpi != ATM_VPI_UNSPEC && vci != ATM_VCI_UNSPEC)
+		clear_bit(ATM_VF_PARTIAL, &vcc->flags);
+	else
+		if (test_bit(ATM_VF_PARTIAL, &vcc->flags))
+			return -EINVAL;
+	pr_debug("(TX: cl %d,bw %d-%d,sdu %d; "
+		 "RX: cl %d,bw %d-%d,sdu %d,AAL %s%d)\n",
+		 vcc->qos.txtp.traffic_class, vcc->qos.txtp.min_pcr,
+		 vcc->qos.txtp.max_pcr, vcc->qos.txtp.max_sdu,
+		 vcc->qos.rxtp.traffic_class, vcc->qos.rxtp.min_pcr,
+		 vcc->qos.rxtp.max_pcr, vcc->qos.rxtp.max_sdu,
+		 vcc->qos.aal == ATM_AAL5 ? "" :
+		 vcc->qos.aal == ATM_AAL0 ? "" : " ??? code ",
+		 vcc->qos.aal == ATM_AAL0 ? 0 : vcc->qos.aal);
+	if (!test_bit(ATM_VF_HASQOS, &vcc->flags))
+		return -EBADFD;
+	if (vcc->qos.txtp.traffic_class == ATM_ANYCLASS ||
+	    vcc->qos.rxtp.traffic_class == ATM_ANYCLASS)
+		return -EINVAL;
+	if (likely(itf != ATM_ITF_ANY)) {
+		dev = try_then_request_module(atm_dev_lookup(itf),
+					      "atm-device-%d", itf);
+	} else {
+		dev = NULL;
+		mutex_lock(&atm_dev_mutex);
+		if (!list_empty(&atm_devs)) {
+			dev = list_entry(atm_devs.next,
+					 struct atm_dev, dev_list);
+			atm_dev_hold(dev);
+		}
+		mutex_unlock(&atm_dev_mutex);
+	}
+	if (!dev)
+		return -ENODEV;
+	error = __vcc_connect(vcc, dev, vpi, vci);
+	if (error) {
+		atm_dev_put(dev);
+		return error;
+	}
+	if (vpi == ATM_VPI_UNSPEC || vci == ATM_VCI_UNSPEC)
+		set_bit(ATM_VF_PARTIAL, &vcc->flags);
+	if (test_bit(ATM_VF_READY, &ATM_SD(sock)->flags))
+		sock->state = SS_CONNECTED;
+	return 0;
+}
+
+int vcc_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
+		int flags)
+{
+	struct sock *sk = sock->sk;
+	struct atm_vcc *vcc;
+	struct sk_buff *skb;
+	int copied, error = -EINVAL;
+
+	if (sock->state != SS_CONNECTED)
+		return -ENOTCONN;
+
+	/* only handle MSG_DONTWAIT and MSG_PEEK */
+	if (flags & ~(MSG_DONTWAIT | MSG_PEEK))
+		return -EOPNOTSUPP;
+
+	vcc = ATM_SD(sock);
+	if (test_bit(ATM_VF_CLOSE, &vcc->flags) ||
+	    !test_bit(ATM_VF_READY, &vcc->flags))
+		return 0;
+
+	skb = skb_recv_datagram(sk, flags, &error);
+	if (!skb)
+		return error;
+
+	copied = skb->len;
+	if (copied > size) {
+		copied = size;
+		msg->msg_flags |= MSG_TRUNC;
+	}
+
+	error = skb_copy_datagram_msg(skb, 0, msg, copied);
+	if (error)
+		return error;
+	sock_recv_cmsgs(msg, sk, skb);
+
+	if (!(flags & MSG_PEEK)) {
+		pr_debug("%d -= %d\n", atomic_read(&sk->sk_rmem_alloc),
+			 skb->truesize);
+		atm_return(vcc, skb->truesize);
+	}
+
+	skb_free_datagram(sk, skb);
+	return copied;
+}
+
+int vcc_sendmsg(struct socket *sock, struct msghdr *m, size_t size)
+{
+	struct sock *sk = sock->sk;
+	DEFINE_WAIT(wait);
+	struct atm_vcc *vcc;
+	struct sk_buff *skb;
+	int eff, error;
+
+	lock_sock(sk);
+	if (sock->state != SS_CONNECTED) {
+		error = -ENOTCONN;
+		goto out;
+	}
+	if (m->msg_name) {
+		error = -EISCONN;
+		goto out;
+	}
+	vcc = ATM_SD(sock);
+	if (test_bit(ATM_VF_CLOSE, &vcc->flags) ||
+	    !test_bit(ATM_VF_READY, &vcc->flags)) {
+		error = -EPIPE;
+		send_sig(SIGPIPE, current, 0);
+		goto out;
+	}
+	if (!size) {
+		error = 0;
+		goto out;
+	}
+	if (size > vcc->qos.txtp.max_sdu) {
+		error = -EMSGSIZE;
+		goto out;
+	}
+
+	eff = (size+3) & ~3; /* align to word boundary */
+	prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
+	error = 0;
+	while (!vcc_tx_ready(vcc, eff)) {
+		if (m->msg_flags & MSG_DONTWAIT) {
+			error = -EAGAIN;
+			break;
+		}
+		schedule();
+		if (signal_pending(current)) {
+			error = -ERESTARTSYS;
+			break;
+		}
+		if (test_bit(ATM_VF_CLOSE, &vcc->flags) ||
+		    !test_bit(ATM_VF_READY, &vcc->flags)) {
+			error = -EPIPE;
+			send_sig(SIGPIPE, current, 0);
+			break;
+		}
+		prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
+	}
+	finish_wait(sk_sleep(sk), &wait);
+	if (error)
+		goto out;
+
+	skb = alloc_skb(eff, GFP_KERNEL);
+	if (!skb) {
+		error = -ENOMEM;
+		goto out;
+	}
+	pr_debug("%d += %d\n", sk_wmem_alloc_get(sk), skb->truesize);
+	atm_account_tx(vcc, skb);
+
+	skb->dev = NULL; /* for paths shared with net_device interfaces */
+	if (!copy_from_iter_full(skb_put(skb, size), size, &m->msg_iter)) {
+		error = -EFAULT;
+		goto free_skb;
+	}
+	if (eff != size)
+		memset(skb->data + size, 0, eff-size);
+
+	error = vcc->dev->ops->send(vcc, skb);
+	error = error ? error : size;
+out:
+	release_sock(sk);
+	return error;
+free_skb:
+	atm_return_tx(vcc, skb);
+	kfree_skb(skb);
+	goto out;
+}
+
+__poll_t vcc_poll(struct file *file, struct socket *sock, poll_table *wait)
+{
+	struct sock *sk = sock->sk;
+	struct atm_vcc *vcc;
+	__poll_t mask;
+
+	sock_poll_wait(file, sock, wait);
+	mask = 0;
+
+	vcc = ATM_SD(sock);
+
+	/* exceptional events */
+	if (sk->sk_err)
+		mask = EPOLLERR;
+
+	if (test_bit(ATM_VF_CLOSE, &vcc->flags))
+		mask |= EPOLLHUP;
+
+	/* readable? */
+	if (!skb_queue_empty_lockless(&sk->sk_receive_queue))
+		mask |= EPOLLIN | EPOLLRDNORM;
+
+	/* writable? */
+	if (vcc->qos.txtp.traffic_class != ATM_NONE &&
+	    vcc_writable(sk))
+		mask |= EPOLLOUT | EPOLLWRNORM | EPOLLWRBAND;
+
+	return mask;
+}
+
+static int check_tp(const struct atm_trafprm *tp)
+{
+	/* @@@ Should be merged with adjust_tp */
+	if (tp->traffic_class > ATM_ANYCLASS)
+		return -EINVAL;
+	if (!tp->traffic_class || tp->traffic_class == ATM_ANYCLASS)
+		return 0;
+	if (tp->traffic_class != ATM_UBR && !tp->min_pcr && !tp->pcr &&
+	    !tp->max_pcr)
+		return -EINVAL;
+	if (tp->min_pcr == ATM_MAX_PCR)
+		return -EINVAL;
+	if (tp->min_pcr && tp->max_pcr && tp->max_pcr != ATM_MAX_PCR &&
+	    tp->min_pcr > tp->max_pcr)
+		return -EINVAL;
+	/*
+	 * We allow pcr to be outside [min_pcr,max_pcr], because later
+	 * adjustment may still push it in the valid range.
+	 */
+	return 0;
+}
+
+static int check_qos(const struct atm_qos *qos)
+{
+	int error;
+
+	if (!qos->txtp.traffic_class && !qos->rxtp.traffic_class)
+		return -EINVAL;
+	if (qos->txtp.traffic_class != qos->rxtp.traffic_class &&
+	    qos->txtp.traffic_class && qos->rxtp.traffic_class &&
+	    qos->txtp.traffic_class != ATM_ANYCLASS &&
+	    qos->rxtp.traffic_class != ATM_ANYCLASS)
+		return -EINVAL;
+	error = check_tp(&qos->txtp);
+	if (error)
+		return error;
+	return check_tp(&qos->rxtp);
+}
+
+int vcc_setsockopt(struct socket *sock, int level, int optname,
+		   sockptr_t optval, unsigned int optlen)
+{
+	struct atm_vcc *vcc;
+	int value;
+	int error;
+
+	if (__SO_LEVEL_MATCH(optname, level) && optlen != __SO_SIZE(optname))
+		return -EINVAL;
+
+	vcc = ATM_SD(sock);
+	switch (optname) {
+	case SO_ATMQOS:
+	{
+		struct atm_qos qos;
+
+		error = copy_safe_from_sockptr(&qos, sizeof(qos), optval,
+					       optlen);
+		if (error)
+			return error;
+		error = check_qos(&qos);
+		if (error)
+			return error;
+		/* QoS cannot be renegotiated on an already connected VCC. */
+		if (sock->state == SS_CONNECTED)
+			return -EOPNOTSUPP;
+		if (sock->state != SS_UNCONNECTED)
+			return -EBADFD;
+		vcc->qos = qos;
+		set_bit(ATM_VF_HASQOS, &vcc->flags);
+		return 0;
+	}
+	case SO_SETCLP:
+		error = copy_safe_from_sockptr(&value, sizeof(value), optval,
+					       optlen);
+		if (error)
+			return error;
+		if (value)
+			vcc->atm_options |= ATM_ATMOPT_CLP;
+		else
+			vcc->atm_options &= ~ATM_ATMOPT_CLP;
+		return 0;
+	default:
+		return -EINVAL;
+	}
+}
+
+int vcc_getsockopt(struct socket *sock, int level, int optname,
+		   sockopt_t *opt)
+{
+	struct atm_vcc *vcc;
+	int val;
+	int len;
+
+	len = opt->optlen;
+	if (__SO_LEVEL_MATCH(optname, level) && len != __SO_SIZE(optname))
+		return -EINVAL;
+
+	vcc = ATM_SD(sock);
+	switch (optname) {
+	case SO_ATMQOS:
+		if (!test_bit(ATM_VF_HASQOS, &vcc->flags))
+			return -EINVAL;
+		return copy_to_iter(&vcc->qos, sizeof(vcc->qos),
+				    &opt->iter_out) != sizeof(vcc->qos)
+			? -EFAULT : 0;
+	case SO_SETCLP:
+		val = vcc->atm_options & ATM_ATMOPT_CLP ? 1 : 0;
+		return copy_to_iter(&val, sizeof(val), &opt->iter_out) !=
+		       sizeof(val) ? -EFAULT : 0;
+	case SO_ATMPVC:
+	{
+		struct sockaddr_atmpvc pvc;
+
+		if (!vcc->dev || !test_bit(ATM_VF_ADDR, &vcc->flags))
+			return -ENOTCONN;
+		memset(&pvc, 0, sizeof(pvc));
+		pvc.sap_family = AF_ATMPVC;
+		pvc.sap_addr.itf = vcc->dev->number;
+		pvc.sap_addr.vpi = vcc->vpi;
+		pvc.sap_addr.vci = vcc->vci;
+		return copy_to_iter(&pvc, sizeof(pvc), &opt->iter_out) !=
+		       sizeof(pvc) ? -EFAULT : 0;
+	}
+	default:
+		return -EINVAL;
+	}
+}
+
+int register_atmdevice_notifier(struct notifier_block *nb)
+{
+	return atomic_notifier_chain_register(&atm_dev_notify_chain, nb);
+}
+EXPORT_SYMBOL_GPL(register_atmdevice_notifier);
+
+void unregister_atmdevice_notifier(struct notifier_block *nb)
+{
+	atomic_notifier_chain_unregister(&atm_dev_notify_chain, nb);
+}
+EXPORT_SYMBOL_GPL(unregister_atmdevice_notifier);
+
+static int __init atm_init(void)
+{
+	int error;
+
+	error = proto_register(&vcc_proto, 0);
+	if (error < 0)
+		goto out;
+	error = atmpvc_init();
+	if (error < 0) {
+		pr_err("atmpvc_init() failed with %d\n", error);
+		goto out_unregister_vcc_proto;
+	}
+	error = atm_proc_init();
+	if (error < 0) {
+		pr_err("atm_proc_init() failed with %d\n", error);
+		goto out_atmpvc_exit;
+	}
+	error = atm_sysfs_init();
+	if (error < 0) {
+		pr_err("atm_sysfs_init() failed with %d\n", error);
+		goto out_atmproc_exit;
+	}
+out:
+	return error;
+out_atmproc_exit:
+	atm_proc_exit();
+out_atmpvc_exit:
+	atmpvc_exit();
+out_unregister_vcc_proto:
+	proto_unregister(&vcc_proto);
+	goto out;
+}
+
+static void __exit atm_exit(void)
+{
+	atm_proc_exit();
+	atm_sysfs_exit();
+	atmpvc_exit();
+	proto_unregister(&vcc_proto);
+}
+
+subsys_initcall(atm_init);
+
+module_exit(atm_exit);
+
+MODULE_DESCRIPTION("Asynchronous Transfer Mode (ATM) networking core");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_NETPROTO(PF_ATMPVC);
diff --git a/net/atm/common.h b/net/atm/common.h
new file mode 100644
index 000000000..11cb51dd7
--- /dev/null
+++ b/net/atm/common.h
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* net/atm/common.h - ATM sockets (common part for PVC and SVC) */
+
+/* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
+
+
+#ifndef NET_ATM_COMMON_H
+#define NET_ATM_COMMON_H
+
+#include <linux/net.h>
+#include <linux/poll.h> /* for poll_table */
+
+
+int vcc_create(struct net *net, struct socket *sock, int protocol, int family, int kern);
+int vcc_release(struct socket *sock);
+int vcc_connect(struct socket *sock, int itf, short vpi, int vci);
+int vcc_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
+		int flags);
+int vcc_sendmsg(struct socket *sock, struct msghdr *m, size_t total_len);
+__poll_t vcc_poll(struct file *file, struct socket *sock, poll_table *wait);
+int vcc_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
+int vcc_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
+int vcc_setsockopt(struct socket *sock, int level, int optname,
+		   sockptr_t optval, unsigned int optlen);
+int vcc_getsockopt(struct socket *sock, int level, int optname,
+		   sockopt_t *opt);
+void vcc_process_recv_queue(struct atm_vcc *vcc);
+
+int atmpvc_init(void);
+void atmpvc_exit(void);
+int atm_sysfs_init(void);
+void atm_sysfs_exit(void);
+
+#ifdef CONFIG_PROC_FS
+int atm_proc_init(void);
+void atm_proc_exit(void);
+#else
+static inline int atm_proc_init(void)
+{
+	return 0;
+}
+
+static inline void atm_proc_exit(void)
+{
+	/* nothing */
+}
+#endif /* CONFIG_PROC_FS */
+
+void atm_dev_release_vccs(struct atm_dev *dev);
+
+#endif
diff --git a/net/atm/ioctl.c b/net/atm/ioctl.c
new file mode 100644
index 000000000..194587fc1
--- /dev/null
+++ b/net/atm/ioctl.c
@@ -0,0 +1,293 @@
+// SPDX-License-Identifier: GPL-2.0
+/* ATM ioctl handling */
+
+/* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
+/* 2003 John Levon  <levon@movementarian.org> */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
+
+#include <linux/module.h>
+#include <linux/kmod.h>
+#include <linux/net.h>		/* struct socket, struct proto_ops */
+#include <linux/atm.h>		/* ATM stuff */
+#include <linux/atmdev.h>
+#include <linux/capability.h>
+#include <linux/mutex.h>
+#include <asm/ioctls.h>
+#include <net/compat.h>
+
+#include "resources.h"
+#include "common.h"
+
+
+static DEFINE_MUTEX(ioctl_mutex);
+static LIST_HEAD(ioctl_list);
+
+
+void register_atm_ioctl(struct atm_ioctl *ioctl)
+{
+	mutex_lock(&ioctl_mutex);
+	list_add_tail(&ioctl->list, &ioctl_list);
+	mutex_unlock(&ioctl_mutex);
+}
+EXPORT_SYMBOL(register_atm_ioctl);
+
+void deregister_atm_ioctl(struct atm_ioctl *ioctl)
+{
+	mutex_lock(&ioctl_mutex);
+	list_del(&ioctl->list);
+	mutex_unlock(&ioctl_mutex);
+}
+EXPORT_SYMBOL(deregister_atm_ioctl);
+
+static int do_vcc_ioctl(struct socket *sock, unsigned int cmd,
+			unsigned long arg, int compat)
+{
+	struct sock *sk = sock->sk;
+	struct atm_vcc *vcc;
+	int error;
+	struct list_head *pos;
+	void __user *argp = (void __user *)arg;
+	void __user *buf;
+	int __user *len;
+
+	vcc = ATM_SD(sock);
+	switch (cmd) {
+	case SIOCOUTQ:
+		if (sock->state != SS_CONNECTED ||
+		    !test_bit(ATM_VF_READY, &vcc->flags)) {
+			error =  -EINVAL;
+			goto done;
+		}
+		error = put_user(sk->sk_sndbuf - sk_wmem_alloc_get(sk),
+				 (int __user *)argp);
+		goto done;
+	case SIOCINQ:
+	{
+		struct sk_buff *skb;
+		int amount;
+
+		if (sock->state != SS_CONNECTED) {
+			error = -EINVAL;
+			goto done;
+		}
+		spin_lock_irq(&sk->sk_receive_queue.lock);
+		skb = skb_peek(&sk->sk_receive_queue);
+		amount = skb ? skb->len : 0;
+		spin_unlock_irq(&sk->sk_receive_queue.lock);
+		error = put_user(amount, (int __user *)argp);
+		goto done;
+	}
+	case ATM_SETSC:
+		net_warn_ratelimited("ATM_SETSC is obsolete; used by %s:%d\n",
+				     current->comm, task_pid_nr(current));
+		error = 0;
+		goto done;
+	case ATM_SETBACKEND:
+	case ATM_NEWBACKENDIF:
+	{
+		atm_backend_t backend;
+		error = get_user(backend, (atm_backend_t __user *)argp);
+		if (error)
+			goto done;
+		switch (backend) {
+		case ATM_BACKEND_PPP:
+			request_module("pppoatm");
+			break;
+		case ATM_BACKEND_BR2684:
+			request_module("br2684");
+			break;
+		}
+		break;
+	}
+	}
+
+	error = -ENOIOCTLCMD;
+
+	mutex_lock(&ioctl_mutex);
+	list_for_each(pos, &ioctl_list) {
+		struct atm_ioctl *ic = list_entry(pos, struct atm_ioctl, list);
+		if (try_module_get(ic->owner)) {
+			error = ic->ioctl(sock, cmd, arg);
+			module_put(ic->owner);
+			if (error != -ENOIOCTLCMD)
+				break;
+		}
+	}
+	mutex_unlock(&ioctl_mutex);
+
+	if (error != -ENOIOCTLCMD)
+		goto done;
+
+	if (cmd == ATM_GETNAMES) {
+		if (IS_ENABLED(CONFIG_COMPAT) && compat) {
+#ifdef CONFIG_COMPAT
+			struct compat_atm_iobuf __user *ciobuf = argp;
+			compat_uptr_t cbuf;
+			len = &ciobuf->length;
+			if (get_user(cbuf, &ciobuf->buffer))
+				return -EFAULT;
+			buf = compat_ptr(cbuf);
+#endif
+		} else {
+			struct atm_iobuf __user *iobuf = argp;
+			len = &iobuf->length;
+			if (get_user(buf, &iobuf->buffer))
+				return -EFAULT;
+		}
+		error = atm_getnames(buf, len);
+	} else {
+		int number;
+
+		if (IS_ENABLED(CONFIG_COMPAT) && compat) {
+#ifdef CONFIG_COMPAT
+			struct compat_atmif_sioc __user *csioc = argp;
+			compat_uptr_t carg;
+
+			len = &csioc->length;
+			if (get_user(carg, &csioc->arg))
+				return -EFAULT;
+			buf = compat_ptr(carg);
+			if (get_user(number, &csioc->number))
+				return -EFAULT;
+#endif
+		} else {
+			struct atmif_sioc __user *sioc = argp;
+
+			len = &sioc->length;
+			if (get_user(buf, &sioc->arg))
+				return -EFAULT;
+			if (get_user(number, &sioc->number))
+				return -EFAULT;
+		}
+		error = atm_dev_ioctl(cmd, buf, len, number, compat);
+	}
+
+done:
+	return error;
+}
+
+int vcc_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
+{
+	return do_vcc_ioctl(sock, cmd, arg, 0);
+}
+
+#ifdef CONFIG_COMPAT
+/*
+ * FIXME:
+ * The compat_ioctl handling is duplicated, using both these conversion
+ * routines and the compat argument to the actual handlers. Both
+ * versions are somewhat incomplete and should be merged, e.g. by
+ * moving the ioctl number translation into the actual handlers and
+ * killing the conversion code.
+ *
+ * -arnd, November 2009
+ */
+#define ATM_GETLINKRATE32 _IOW('a', ATMIOC_ITF+1, struct compat_atmif_sioc)
+#define ATM_GETNAMES32    _IOW('a', ATMIOC_ITF+3, struct compat_atm_iobuf)
+#define ATM_GETTYPE32     _IOW('a', ATMIOC_ITF+4, struct compat_atmif_sioc)
+#define ATM_GETESI32	  _IOW('a', ATMIOC_ITF+5, struct compat_atmif_sioc)
+#define ATM_GETCIRANGE32  _IOW('a', ATMIOC_ITF+10, struct compat_atmif_sioc)
+#define ATM_SETCIRANGE32  _IOW('a', ATMIOC_ITF+11, struct compat_atmif_sioc)
+#define ATM_SETESI32      _IOW('a', ATMIOC_ITF+12, struct compat_atmif_sioc)
+#define ATM_SETESIF32     _IOW('a', ATMIOC_ITF+13, struct compat_atmif_sioc)
+#define ATM_GETSTAT32     _IOW('a', ATMIOC_SARCOM+0, struct compat_atmif_sioc)
+#define ATM_GETSTATZ32    _IOW('a', ATMIOC_SARCOM+1, struct compat_atmif_sioc)
+#define ATM_GETLOOP32	  _IOW('a', ATMIOC_SARCOM+2, struct compat_atmif_sioc)
+#define ATM_SETLOOP32	  _IOW('a', ATMIOC_SARCOM+3, struct compat_atmif_sioc)
+#define ATM_QUERYLOOP32	  _IOW('a', ATMIOC_SARCOM+4, struct compat_atmif_sioc)
+
+static struct {
+	unsigned int cmd32;
+	unsigned int cmd;
+} atm_ioctl_map[] = {
+	{ ATM_GETLINKRATE32, ATM_GETLINKRATE },
+	{ ATM_GETNAMES32,    ATM_GETNAMES },
+	{ ATM_GETTYPE32,     ATM_GETTYPE },
+	{ ATM_GETESI32,	     ATM_GETESI },
+	{ ATM_GETCIRANGE32,  ATM_GETCIRANGE },
+	{ ATM_SETCIRANGE32,  ATM_SETCIRANGE },
+	{ ATM_SETESI32,	     ATM_SETESI },
+	{ ATM_SETESIF32,     ATM_SETESIF },
+	{ ATM_GETSTAT32,     ATM_GETSTAT },
+	{ ATM_GETSTATZ32,    ATM_GETSTATZ },
+	{ ATM_GETLOOP32,     ATM_GETLOOP },
+	{ ATM_SETLOOP32,     ATM_SETLOOP },
+	{ ATM_QUERYLOOP32,   ATM_QUERYLOOP },
+};
+
+#define NR_ATM_IOCTL ARRAY_SIZE(atm_ioctl_map)
+
+static int do_atm_iobuf(struct socket *sock, unsigned int cmd,
+			unsigned long arg)
+{
+	struct compat_atm_iobuf __user *iobuf32 = compat_ptr(arg);
+	u32 data;
+
+	if (get_user(data, &iobuf32->buffer))
+		return -EFAULT;
+
+	return atm_getnames(&iobuf32->length, compat_ptr(data));
+}
+
+static int do_atmif_sioc(struct socket *sock, unsigned int cmd,
+			 unsigned long arg)
+{
+	struct compat_atmif_sioc __user *sioc32 = compat_ptr(arg);
+	int number;
+	u32 data;
+
+	if (get_user(data, &sioc32->arg) || get_user(number, &sioc32->number))
+		return -EFAULT;
+	return atm_dev_ioctl(cmd, compat_ptr(data), &sioc32->length, number, 0);
+}
+
+static int do_atm_ioctl(struct socket *sock, unsigned int cmd32,
+			unsigned long arg)
+{
+	int i;
+	unsigned int cmd = 0;
+
+	for (i = 0; i < NR_ATM_IOCTL; i++) {
+		if (cmd32 == atm_ioctl_map[i].cmd32) {
+			cmd = atm_ioctl_map[i].cmd;
+			break;
+		}
+	}
+	if (i == NR_ATM_IOCTL)
+		return -EINVAL;
+
+	switch (cmd) {
+	case ATM_GETNAMES:
+		return do_atm_iobuf(sock, cmd, arg);
+
+	case ATM_GETLINKRATE:
+	case ATM_GETTYPE:
+	case ATM_GETESI:
+	case ATM_GETCIRANGE:
+	case ATM_SETCIRANGE:
+	case ATM_SETESI:
+	case ATM_SETESIF:
+	case ATM_GETSTAT:
+	case ATM_GETSTATZ:
+	case ATM_GETLOOP:
+	case ATM_SETLOOP:
+	case ATM_QUERYLOOP:
+		return do_atmif_sioc(sock, cmd, arg);
+	}
+
+	return -EINVAL;
+}
+
+int vcc_compat_ioctl(struct socket *sock, unsigned int cmd,
+		     unsigned long arg)
+{
+	int ret;
+
+	ret = do_vcc_ioctl(sock, cmd, arg, 1);
+	if (ret != -ENOIOCTLCMD)
+		return ret;
+
+	return do_atm_ioctl(sock, cmd, arg);
+}
+#endif
diff --git a/net/atm/pppoatm.c b/net/atm/pppoatm.c
new file mode 100644
index 000000000..6da52d12d
--- /dev/null
+++ b/net/atm/pppoatm.c
@@ -0,0 +1,490 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* net/atm/pppoatm.c - RFC2364 PPP over ATM/AAL5 */
+
+/* Copyright 1999-2000 by Mitchell Blank Jr */
+/* Based on clip.c; 1995-1999 by Werner Almesberger, EPFL LRC/ICA */
+/* And on ppp_async.c; Copyright 1999 Paul Mackerras */
+/* And help from Jens Axboe */
+
+/*
+ *
+ * This driver provides the encapsulation and framing for sending
+ * and receiving PPP frames in ATM AAL5 PDUs.
+ */
+
+/*
+ * One shortcoming of this driver is that it does not comply with
+ * section 8 of RFC2364 - we are supposed to detect a change
+ * in encapsulation and immediately abort the connection (in order
+ * to avoid a black-hole being created if our peer loses state
+ * and changes encapsulation unilaterally.  However, since the
+ * ppp_generic layer actually does the decapsulation, we need
+ * a way of notifying it when we _think_ there might be a problem)
+ * There's two cases:
+ *   1.	LLC-encapsulation was missing when it was enabled.  In
+ *	this case, we should tell the upper layer "tear down
+ *	this session if this skb looks ok to you"
+ *   2.	LLC-encapsulation was present when it was disabled.  Then
+ *	we need to tell the upper layer "this packet may be
+ *	ok, but if its in error tear down the session"
+ * These hooks are not yet available in ppp_generic
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/skbuff.h>
+#include <linux/slab.h>
+#include <linux/atm.h>
+#include <linux/atmdev.h>
+#include <linux/capability.h>
+#include <linux/ppp_defs.h>
+#include <linux/ppp-ioctl.h>
+#include <linux/ppp_channel.h>
+#include <linux/atmppp.h>
+
+#include "common.h"
+
+enum pppoatm_encaps {
+	e_autodetect = PPPOATM_ENCAPS_AUTODETECT,
+	e_vc = PPPOATM_ENCAPS_VC,
+	e_llc = PPPOATM_ENCAPS_LLC,
+};
+
+struct pppoatm_vcc {
+	struct atm_vcc	*atmvcc;	/* VCC descriptor */
+	void (*old_push)(struct atm_vcc *, struct sk_buff *);
+	void (*old_pop)(struct atm_vcc *, struct sk_buff *);
+	void (*old_release_cb)(struct atm_vcc *);
+	struct module *old_owner;
+					/* keep old push/pop for detaching */
+	enum pppoatm_encaps encaps;
+	atomic_t inflight;
+	unsigned long blocked;
+	int flags;			/* SC_COMP_PROT - compress protocol */
+	struct ppp_channel chan;	/* interface to generic ppp layer */
+	struct tasklet_struct wakeup_tasklet;
+};
+
+/*
+ * We want to allow two packets in the queue. The one that's currently in
+ * flight, and *one* queued up ready for the ATM device to send immediately
+ * from its TX done IRQ. We want to be able to use atomic_inc_not_zero(), so
+ * inflight == -2 represents an empty queue, -1 one packet, and zero means
+ * there are two packets in the queue.
+ */
+#define NONE_INFLIGHT -2
+
+#define BLOCKED 0
+
+/*
+ * Header used for LLC Encapsulated PPP (4 bytes) followed by the LCP protocol
+ * ID (0xC021) used in autodetection
+ */
+static const unsigned char pppllc[6] = { 0xFE, 0xFE, 0x03, 0xCF, 0xC0, 0x21 };
+#define LLC_LEN		(4)
+
+static inline struct pppoatm_vcc *atmvcc_to_pvcc(const struct atm_vcc *atmvcc)
+{
+	return (struct pppoatm_vcc *) (atmvcc->user_back);
+}
+
+static inline struct pppoatm_vcc *chan_to_pvcc(const struct ppp_channel *chan)
+{
+	return (struct pppoatm_vcc *) (chan->private);
+}
+
+/*
+ * We can't do this directly from our _pop handler, since the ppp code
+ * doesn't want to be called in interrupt context, so we do it from
+ * a tasklet
+ */
+static void pppoatm_wakeup_sender(struct tasklet_struct *t)
+{
+	struct pppoatm_vcc *pvcc = from_tasklet(pvcc, t, wakeup_tasklet);
+
+	ppp_output_wakeup(&pvcc->chan);
+}
+
+static void pppoatm_release_cb(struct atm_vcc *atmvcc)
+{
+	struct pppoatm_vcc *pvcc = atmvcc_to_pvcc(atmvcc);
+
+	/*
+	 * As in pppoatm_pop(), it's safe to clear the BLOCKED bit here because
+	 * the wakeup *can't* race with pppoatm_send(). They both hold the PPP
+	 * channel's ->downl lock. And the potential race with *setting* it,
+	 * which leads to the double-check dance in pppoatm_may_send(), doesn't
+	 * exist here. In the sock_owned_by_user() case in pppoatm_send(), we
+	 * set the BLOCKED bit while the socket is still locked. We know that
+	 * ->release_cb() can't be called until that's done.
+	 */
+	if (test_and_clear_bit(BLOCKED, &pvcc->blocked))
+		tasklet_schedule(&pvcc->wakeup_tasklet);
+	if (pvcc->old_release_cb)
+		pvcc->old_release_cb(atmvcc);
+}
+/*
+ * This gets called every time the ATM card has finished sending our
+ * skb.  The ->old_pop will take care up normal atm flow control,
+ * but we also need to wake up the device if we blocked it
+ */
+static void pppoatm_pop(struct atm_vcc *atmvcc, struct sk_buff *skb)
+{
+	struct pppoatm_vcc *pvcc = atmvcc_to_pvcc(atmvcc);
+
+	pvcc->old_pop(atmvcc, skb);
+	atomic_dec(&pvcc->inflight);
+
+	/*
+	 * We always used to run the wakeup tasklet unconditionally here, for
+	 * fear of race conditions where we clear the BLOCKED flag just as we
+	 * refuse another packet in pppoatm_send(). This was quite inefficient.
+	 *
+	 * In fact it's OK. The PPP core will only ever call pppoatm_send()
+	 * while holding the channel->downl lock. And ppp_output_wakeup() as
+	 * called by the tasklet will *also* grab that lock. So even if another
+	 * CPU is in pppoatm_send() right now, the tasklet isn't going to race
+	 * with it. The wakeup *will* happen after the other CPU is safely out
+	 * of pppoatm_send() again.
+	 *
+	 * So if the CPU in pppoatm_send() has already set the BLOCKED bit and
+	 * it about to return, that's fine. We trigger a wakeup which will
+	 * happen later. And if the CPU in pppoatm_send() *hasn't* set the
+	 * BLOCKED bit yet, that's fine too because of the double check in
+	 * pppoatm_may_send() which is commented there.
+	 */
+	if (test_and_clear_bit(BLOCKED, &pvcc->blocked))
+		tasklet_schedule(&pvcc->wakeup_tasklet);
+}
+
+/*
+ * Unbind from PPP - currently we only do this when closing the socket,
+ * but we could put this into an ioctl if need be
+ */
+static void pppoatm_unassign_vcc(struct atm_vcc *atmvcc)
+{
+	struct pppoatm_vcc *pvcc;
+	pvcc = atmvcc_to_pvcc(atmvcc);
+	atmvcc->push = pvcc->old_push;
+	atmvcc->pop = pvcc->old_pop;
+	atmvcc->release_cb = pvcc->old_release_cb;
+	tasklet_kill(&pvcc->wakeup_tasklet);
+	ppp_unregister_channel(&pvcc->chan);
+	atmvcc->user_back = NULL;
+	kfree(pvcc);
+}
+
+/* Called when an AAL5 PDU comes in */
+static void pppoatm_push(struct atm_vcc *atmvcc, struct sk_buff *skb)
+{
+	struct pppoatm_vcc *pvcc = atmvcc_to_pvcc(atmvcc);
+	pr_debug("\n");
+	if (skb == NULL) {			/* VCC was closed */
+		struct module *module;
+
+		pr_debug("removing ATMPPP VCC %p\n", pvcc);
+		module = pvcc->old_owner;
+		pppoatm_unassign_vcc(atmvcc);
+		atmvcc->push(atmvcc, NULL);	/* Pass along bad news */
+		module_put(module);
+		return;
+	}
+	atm_return(atmvcc, skb->truesize);
+	switch (pvcc->encaps) {
+	case e_llc:
+		if (skb->len < LLC_LEN ||
+		    memcmp(skb->data, pppllc, LLC_LEN))
+			goto error;
+		skb_pull(skb, LLC_LEN);
+		break;
+	case e_autodetect:
+		if (pvcc->chan.ppp == NULL) {	/* Not bound yet! */
+			kfree_skb(skb);
+			return;
+		}
+		if (skb->len >= sizeof(pppllc) &&
+		    !memcmp(skb->data, pppllc, sizeof(pppllc))) {
+			pvcc->encaps = e_llc;
+			skb_pull(skb, LLC_LEN);
+			break;
+		}
+		if (skb->len >= (sizeof(pppllc) - LLC_LEN) &&
+		    !memcmp(skb->data, &pppllc[LLC_LEN],
+		    sizeof(pppllc) - LLC_LEN)) {
+			pvcc->encaps = e_vc;
+			pvcc->chan.mtu += LLC_LEN;
+			break;
+		}
+		pr_debug("Couldn't autodetect yet (skb: %6ph)\n", skb->data);
+		goto error;
+	case e_vc:
+		break;
+	}
+	ppp_input(&pvcc->chan, skb);
+	return;
+
+error:
+	kfree_skb(skb);
+	ppp_input_error(&pvcc->chan);
+}
+
+static int pppoatm_may_send(struct pppoatm_vcc *pvcc, int size)
+{
+	/*
+	 * It's not clear that we need to bother with using atm_may_send()
+	 * to check we don't exceed sk->sk_sndbuf. If userspace sets a
+	 * value of sk_sndbuf which is lower than the MTU, we're going to
+	 * block for ever. But the code always did that before we introduced
+	 * the packet count limit, so...
+	 */
+	if (atm_may_send(pvcc->atmvcc, size) &&
+	    atomic_inc_not_zero(&pvcc->inflight))
+		return 1;
+
+	/*
+	 * We use test_and_set_bit() rather than set_bit() here because
+	 * we need to ensure there's a memory barrier after it. The bit
+	 * *must* be set before we do the atomic_inc() on pvcc->inflight.
+	 * There's no smp_mb__after_set_bit(), so it's this or abuse
+	 * smp_mb__after_atomic().
+	 */
+	test_and_set_bit(BLOCKED, &pvcc->blocked);
+
+	/*
+	 * We may have raced with pppoatm_pop(). If it ran for the
+	 * last packet in the queue, *just* before we set the BLOCKED
+	 * bit, then it might never run again and the channel could
+	 * remain permanently blocked. Cope with that race by checking
+	 * *again*. If it did run in that window, we'll have space on
+	 * the queue now and can return success. It's harmless to leave
+	 * the BLOCKED flag set, since it's only used as a trigger to
+	 * run the wakeup tasklet. Another wakeup will never hurt.
+	 * If pppoatm_pop() is running but hasn't got as far as making
+	 * space on the queue yet, then it hasn't checked the BLOCKED
+	 * flag yet either, so we're safe in that case too. It'll issue
+	 * an "immediate" wakeup... where "immediate" actually involves
+	 * taking the PPP channel's ->downl lock, which is held by the
+	 * code path that calls pppoatm_send(), and is thus going to
+	 * wait for us to finish.
+	 */
+	if (atm_may_send(pvcc->atmvcc, size) &&
+	    atomic_inc_not_zero(&pvcc->inflight))
+		return 1;
+
+	return 0;
+}
+/*
+ * Called by the ppp_generic.c to send a packet - returns true if packet
+ * was accepted.  If we return false, then it's our job to call
+ * ppp_output_wakeup(chan) when we're feeling more up to it.
+ * Note that in the ENOMEM case (as opposed to the !atm_may_send case)
+ * we should really drop the packet, but the generic layer doesn't
+ * support this yet.  We just return 'DROP_PACKET' which we actually define
+ * as success, just to be clear what we're really doing.
+ */
+#define DROP_PACKET 1
+static int pppoatm_send(struct ppp_channel *chan, struct sk_buff *skb)
+{
+	struct pppoatm_vcc *pvcc = chan_to_pvcc(chan);
+	struct atm_vcc *vcc;
+	int ret;
+
+	ATM_SKB(skb)->vcc = pvcc->atmvcc;
+	pr_debug("(skb=0x%p, vcc=0x%p)\n", skb, pvcc->atmvcc);
+	if (skb->data[0] == '\0' && (pvcc->flags & SC_COMP_PROT))
+		(void) skb_pull(skb, 1);
+
+	vcc = ATM_SKB(skb)->vcc;
+	bh_lock_sock(sk_atm(vcc));
+	if (sock_owned_by_user(sk_atm(vcc))) {
+		/*
+		 * Needs to happen (and be flushed, hence test_and_) before we unlock
+		 * the socket. It needs to be seen by the time our ->release_cb gets
+		 * called.
+		 */
+		test_and_set_bit(BLOCKED, &pvcc->blocked);
+		goto nospace;
+	}
+	if (test_bit(ATM_VF_CLOSE, &vcc->flags) ||
+	    !test_bit(ATM_VF_READY, &vcc->flags)) {
+		bh_unlock_sock(sk_atm(vcc));
+		kfree_skb(skb);
+		return DROP_PACKET;
+	}
+
+	switch (pvcc->encaps) {		/* LLC encapsulation needed */
+	case e_llc:
+		if (skb_headroom(skb) < LLC_LEN) {
+			struct sk_buff *n;
+			n = skb_realloc_headroom(skb, LLC_LEN);
+			if (n != NULL &&
+			    !pppoatm_may_send(pvcc, n->truesize)) {
+				kfree_skb(n);
+				goto nospace;
+			}
+			consume_skb(skb);
+			skb = n;
+			if (skb == NULL) {
+				bh_unlock_sock(sk_atm(vcc));
+				return DROP_PACKET;
+			}
+		} else if (!pppoatm_may_send(pvcc, skb->truesize))
+			goto nospace;
+		memcpy(skb_push(skb, LLC_LEN), pppllc, LLC_LEN);
+		break;
+	case e_vc:
+		if (!pppoatm_may_send(pvcc, skb->truesize))
+			goto nospace;
+		break;
+	case e_autodetect:
+		bh_unlock_sock(sk_atm(vcc));
+		pr_debug("Trying to send without setting encaps!\n");
+		kfree_skb(skb);
+		return 1;
+	}
+
+	atm_account_tx(vcc, skb);
+	pr_debug("atm_skb(%p)->vcc(%p)->dev(%p)\n",
+		 skb, ATM_SKB(skb)->vcc, ATM_SKB(skb)->vcc->dev);
+	ret = ATM_SKB(skb)->vcc->send(ATM_SKB(skb)->vcc, skb)
+	    ? DROP_PACKET : 1;
+	bh_unlock_sock(sk_atm(vcc));
+	return ret;
+nospace:
+	bh_unlock_sock(sk_atm(vcc));
+	/*
+	 * We don't have space to send this SKB now, but we might have
+	 * already applied SC_COMP_PROT compression, so may need to undo
+	 */
+	if ((pvcc->flags & SC_COMP_PROT) && skb_headroom(skb) > 0 &&
+	    skb->data[-1] == '\0')
+		(void) skb_push(skb, 1);
+	return 0;
+}
+
+/* This handles ioctls sent to the /dev/ppp interface */
+static int pppoatm_devppp_ioctl(struct ppp_channel *chan, unsigned int cmd,
+	unsigned long arg)
+{
+	switch (cmd) {
+	case PPPIOCGFLAGS:
+		return put_user(chan_to_pvcc(chan)->flags, (int __user *) arg)
+		    ? -EFAULT : 0;
+	case PPPIOCSFLAGS:
+		return get_user(chan_to_pvcc(chan)->flags, (int __user *) arg)
+		    ? -EFAULT : 0;
+	}
+	return -ENOTTY;
+}
+
+static const struct ppp_channel_ops pppoatm_ops = {
+	.start_xmit = pppoatm_send,
+	.ioctl = pppoatm_devppp_ioctl,
+};
+
+static int pppoatm_assign_vcc(struct atm_vcc *atmvcc, void __user *arg)
+{
+	struct atm_backend_ppp be;
+	struct pppoatm_vcc *pvcc;
+	int err;
+
+	if (copy_from_user(&be, arg, sizeof be))
+		return -EFAULT;
+	if (be.encaps != PPPOATM_ENCAPS_AUTODETECT &&
+	    be.encaps != PPPOATM_ENCAPS_VC && be.encaps != PPPOATM_ENCAPS_LLC)
+		return -EINVAL;
+	pvcc = kzalloc_obj(*pvcc);
+	if (pvcc == NULL)
+		return -ENOMEM;
+	pvcc->atmvcc = atmvcc;
+
+	/* Maximum is zero, so that we can use atomic_inc_not_zero() */
+	atomic_set(&pvcc->inflight, NONE_INFLIGHT);
+	pvcc->old_push = atmvcc->push;
+	pvcc->old_pop = atmvcc->pop;
+	pvcc->old_owner = atmvcc->owner;
+	pvcc->old_release_cb = atmvcc->release_cb;
+	pvcc->encaps = (enum pppoatm_encaps) be.encaps;
+	pvcc->chan.private = pvcc;
+	pvcc->chan.ops = &pppoatm_ops;
+	pvcc->chan.mtu = atmvcc->qos.txtp.max_sdu - PPP_HDRLEN -
+	    (be.encaps == e_vc ? 0 : LLC_LEN);
+	tasklet_setup(&pvcc->wakeup_tasklet, pppoatm_wakeup_sender);
+	err = ppp_register_channel(&pvcc->chan);
+	if (err != 0) {
+		kfree(pvcc);
+		return err;
+	}
+	atmvcc->user_back = pvcc;
+	atmvcc->push = pppoatm_push;
+	atmvcc->pop = pppoatm_pop;
+	atmvcc->release_cb = pppoatm_release_cb;
+	__module_get(THIS_MODULE);
+	atmvcc->owner = THIS_MODULE;
+
+	/* re-process everything received between connection setup and
+	   backend setup */
+	vcc_process_recv_queue(atmvcc);
+	return 0;
+}
+
+/*
+ * This handles ioctls actually performed on our vcc - we must return
+ * -ENOIOCTLCMD for any unrecognized ioctl
+ */
+static int pppoatm_ioctl(struct socket *sock, unsigned int cmd,
+	unsigned long arg)
+{
+	struct atm_vcc *atmvcc = ATM_SD(sock);
+	void __user *argp = (void __user *)arg;
+
+	if (cmd != ATM_SETBACKEND && atmvcc->push != pppoatm_push)
+		return -ENOIOCTLCMD;
+	switch (cmd) {
+	case ATM_SETBACKEND: {
+		atm_backend_t b;
+		if (get_user(b, (atm_backend_t __user *) argp))
+			return -EFAULT;
+		if (b != ATM_BACKEND_PPP)
+			return -ENOIOCTLCMD;
+		if (!capable(CAP_NET_ADMIN))
+			return -EPERM;
+		if (sock->state != SS_CONNECTED)
+			return -EINVAL;
+		return pppoatm_assign_vcc(atmvcc, argp);
+		}
+	case PPPIOCGCHAN:
+		return put_user(ppp_channel_index(&atmvcc_to_pvcc(atmvcc)->
+		    chan), (int __user *) argp) ? -EFAULT : 0;
+	case PPPIOCGUNIT:
+		return put_user(ppp_unit_number(&atmvcc_to_pvcc(atmvcc)->
+		    chan), (int __user *) argp) ? -EFAULT : 0;
+	}
+	return -ENOIOCTLCMD;
+}
+
+static struct atm_ioctl pppoatm_ioctl_ops = {
+	.owner	= THIS_MODULE,
+	.ioctl	= pppoatm_ioctl,
+};
+
+static int __init pppoatm_init(void)
+{
+	register_atm_ioctl(&pppoatm_ioctl_ops);
+	return 0;
+}
+
+static void __exit pppoatm_exit(void)
+{
+	deregister_atm_ioctl(&pppoatm_ioctl_ops);
+}
+
+module_init(pppoatm_init);
+module_exit(pppoatm_exit);
+
+MODULE_AUTHOR("Mitchell Blank Jr <mitch@sfgoth.com>");
+MODULE_DESCRIPTION("RFC2364 PPP over ATM/AAL5");
+MODULE_LICENSE("GPL");
diff --git a/net/atm/proc.c b/net/atm/proc.c
new file mode 100644
index 000000000..8f20b49b9
--- /dev/null
+++ b/net/atm/proc.c
@@ -0,0 +1,333 @@
+// SPDX-License-Identifier: GPL-2.0
+/* net/atm/proc.c - ATM /proc interface
+ *
+ * Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA
+ *
+ * seq_file api usage by romieu@fr.zoreil.com
+ *
+ * Evaluating the efficiency of the whole thing if left as an exercise to
+ * the reader.
+ */
+
+#include <linux/module.h> /* for EXPORT_SYMBOL */
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/fs.h>
+#include <linux/stat.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/errno.h>
+#include <linux/atm.h>
+#include <linux/atmdev.h>
+#include <linux/netdevice.h>
+#include <linux/init.h> /* for __init */
+#include <linux/slab.h>
+#include <net/net_namespace.h>
+#include <linux/uaccess.h>
+#include <linux/param.h> /* for HZ */
+#include <linux/atomic.h>
+#include "resources.h"
+#include "common.h" /* atm_proc_init prototype */
+
+static ssize_t proc_dev_atm_read(struct file *file, char __user *buf,
+				 size_t count, loff_t *pos);
+
+static const struct proc_ops atm_dev_proc_ops = {
+	.proc_read	= proc_dev_atm_read,
+	.proc_lseek	= noop_llseek,
+};
+
+static void add_stats(struct seq_file *seq, const char *aal,
+  const struct k_atm_aal_stats *stats)
+{
+	seq_printf(seq, "%s ( %d %d %d %d %d )", aal,
+		   atomic_read(&stats->tx), atomic_read(&stats->tx_err),
+		   atomic_read(&stats->rx), atomic_read(&stats->rx_err),
+		   atomic_read(&stats->rx_drop));
+}
+
+static void atm_dev_info(struct seq_file *seq, const struct atm_dev *dev)
+{
+	int i;
+
+	seq_printf(seq, "%3d %-8s", dev->number, dev->type);
+	for (i = 0; i < ESI_LEN; i++)
+		seq_printf(seq, "%02x", dev->esi[i]);
+	seq_puts(seq, "  ");
+	add_stats(seq, "0", &dev->stats.aal0);
+	seq_puts(seq, "  ");
+	add_stats(seq, "5", &dev->stats.aal5);
+	seq_printf(seq, "\t[%d]", refcount_read(&dev->refcnt));
+	seq_putc(seq, '\n');
+}
+
+struct vcc_state {
+	int bucket;
+	struct sock *sk;
+};
+
+static inline int compare_family(struct sock *sk, int family)
+{
+	return !family || (sk->sk_family == family);
+}
+
+static int __vcc_walk(struct sock **sock, int family, int *bucket, loff_t l)
+{
+	struct sock *sk = *sock;
+
+	if (sk == SEQ_START_TOKEN) {
+		for (*bucket = 0; *bucket < VCC_HTABLE_SIZE; ++*bucket) {
+			struct hlist_head *head = &vcc_hash[*bucket];
+
+			sk = hlist_empty(head) ? NULL : __sk_head(head);
+			if (sk)
+				break;
+		}
+		l--;
+	}
+try_again:
+	for (; sk; sk = sk_next(sk)) {
+		l -= compare_family(sk, family);
+		if (l < 0)
+			goto out;
+	}
+	if (!sk && ++*bucket < VCC_HTABLE_SIZE) {
+		sk = sk_head(&vcc_hash[*bucket]);
+		goto try_again;
+	}
+	sk = SEQ_START_TOKEN;
+out:
+	*sock = sk;
+	return (l < 0);
+}
+
+static inline void *vcc_walk(struct seq_file *seq, loff_t l)
+{
+	struct vcc_state *state = seq->private;
+	int family = (uintptr_t)(pde_data(file_inode(seq->file)));
+
+	return __vcc_walk(&state->sk, family, &state->bucket, l) ?
+	       state : NULL;
+}
+
+static void *vcc_seq_start(struct seq_file *seq, loff_t *pos)
+	__acquires(vcc_sklist_lock)
+{
+	struct vcc_state *state = seq->private;
+	loff_t left = *pos;
+
+	read_lock(&vcc_sklist_lock);
+	state->sk = SEQ_START_TOKEN;
+	return left ? vcc_walk(seq, left) : SEQ_START_TOKEN;
+}
+
+static void vcc_seq_stop(struct seq_file *seq, void *v)
+	__releases(vcc_sklist_lock)
+{
+	read_unlock(&vcc_sklist_lock);
+}
+
+static void *vcc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	v = vcc_walk(seq, 1);
+	(*pos)++;
+	return v;
+}
+
+static void pvc_info(struct seq_file *seq, struct atm_vcc *vcc)
+{
+	static const char *const class_name[] = {
+		"off", "UBR", "CBR", "VBR", "ABR"};
+	static const char *const aal_name[] = {
+		"---",	"1",	"2",	"3/4",	/*  0- 3 */
+		"???",	"5",	"???",	"???",	/*  4- 7 */
+		"???",	"???",	"???",	"???",	/*  8-11 */
+		"???",	"0",	"???",	"???"};	/* 12-15 */
+
+	seq_printf(seq, "%3d %3d %5d %-3s %7d %-5s %7d %-6s",
+		   vcc->dev->number, vcc->vpi, vcc->vci,
+		   vcc->qos.aal >= ARRAY_SIZE(aal_name) ? "err" :
+		   aal_name[vcc->qos.aal], vcc->qos.rxtp.min_pcr,
+		   class_name[vcc->qos.rxtp.traffic_class],
+		   vcc->qos.txtp.min_pcr,
+		   class_name[vcc->qos.txtp.traffic_class]);
+	seq_putc(seq, '\n');
+}
+
+static void vcc_info(struct seq_file *seq, struct atm_vcc *vcc)
+{
+	struct sock *sk = sk_atm(vcc);
+
+	seq_printf(seq, "%pK ", vcc);
+	if (!vcc->dev)
+		seq_printf(seq, "Unassigned    ");
+	else
+		seq_printf(seq, "%3d %3d %5d ", vcc->dev->number, vcc->vpi,
+			vcc->vci);
+	switch (sk->sk_family) {
+	case AF_ATMPVC:
+		seq_printf(seq, "PVC");
+		break;
+	default:
+		seq_printf(seq, "%3d", sk->sk_family);
+	}
+	seq_printf(seq, " %04lx  %5d %7d/%7d %7d/%7d [%d]\n",
+		   vcc->flags, sk->sk_err,
+		   sk_wmem_alloc_get(sk), sk->sk_sndbuf,
+		   sk_rmem_alloc_get(sk), sk->sk_rcvbuf,
+		   refcount_read(&sk->sk_refcnt));
+}
+
+static int atm_dev_seq_show(struct seq_file *seq, void *v)
+{
+	static char atm_dev_banner[] =
+		"Itf Type    ESI/\"MAC\"addr "
+		"AAL(TX,err,RX,err,drop) ...               [refcnt]\n";
+
+	if (v == &atm_devs)
+		seq_puts(seq, atm_dev_banner);
+	else {
+		struct atm_dev *dev = list_entry(v, struct atm_dev, dev_list);
+
+		atm_dev_info(seq, dev);
+	}
+	return 0;
+}
+
+static const struct seq_operations atm_dev_seq_ops = {
+	.start	= atm_dev_seq_start,
+	.next	= atm_dev_seq_next,
+	.stop	= atm_dev_seq_stop,
+	.show	= atm_dev_seq_show,
+};
+
+static int pvc_seq_show(struct seq_file *seq, void *v)
+{
+	static char atm_pvc_banner[] =
+		"Itf VPI VCI   AAL RX(PCR,Class) TX(PCR,Class)\n";
+
+	if (v == SEQ_START_TOKEN)
+		seq_puts(seq, atm_pvc_banner);
+	else {
+		struct vcc_state *state = seq->private;
+		struct atm_vcc *vcc = atm_sk(state->sk);
+
+		pvc_info(seq, vcc);
+	}
+	return 0;
+}
+
+static const struct seq_operations pvc_seq_ops = {
+	.start	= vcc_seq_start,
+	.next	= vcc_seq_next,
+	.stop	= vcc_seq_stop,
+	.show	= pvc_seq_show,
+};
+
+static int vcc_seq_show(struct seq_file *seq, void *v)
+{
+	if (v == SEQ_START_TOKEN) {
+		seq_printf(seq, sizeof(void *) == 4 ? "%-8s%s" : "%-16s%s",
+			"Address ", "Itf VPI VCI   Fam Flags Reply "
+			"Send buffer     Recv buffer      [refcnt]\n");
+	} else {
+		struct vcc_state *state = seq->private;
+		struct atm_vcc *vcc = atm_sk(state->sk);
+
+		vcc_info(seq, vcc);
+	}
+	return 0;
+}
+
+static const struct seq_operations vcc_seq_ops = {
+	.start	= vcc_seq_start,
+	.next	= vcc_seq_next,
+	.stop	= vcc_seq_stop,
+	.show	= vcc_seq_show,
+};
+
+static ssize_t proc_dev_atm_read(struct file *file, char __user *buf,
+				 size_t count, loff_t *pos)
+{
+	struct atm_dev *dev;
+	unsigned long page;
+	int length;
+
+	if (count == 0)
+		return 0;
+	page = get_zeroed_page(GFP_KERNEL);
+	if (!page)
+		return -ENOMEM;
+	dev = pde_data(file_inode(file));
+	if (!dev->ops->proc_read)
+		length = -EINVAL;
+	else {
+		length = dev->ops->proc_read(dev, pos, (char *)page);
+		if (length > count)
+			length = -EINVAL;
+	}
+	if (length >= 0) {
+		if (copy_to_user(buf, (char *)page, length))
+			length = -EFAULT;
+		(*pos)++;
+	}
+	free_page(page);
+	return length;
+}
+
+struct proc_dir_entry *atm_proc_root;
+EXPORT_SYMBOL(atm_proc_root);
+
+
+int atm_proc_dev_register(struct atm_dev *dev)
+{
+	int error;
+
+	/* No proc info */
+	if (!dev->ops->proc_read)
+		return 0;
+
+	error = -ENOMEM;
+	dev->proc_name = kasprintf(GFP_KERNEL, "%s:%d", dev->type, dev->number);
+	if (!dev->proc_name)
+		goto err_out;
+
+	dev->proc_entry = proc_create_data(dev->proc_name, 0, atm_proc_root,
+					   &atm_dev_proc_ops, dev);
+	if (!dev->proc_entry)
+		goto err_free_name;
+	return 0;
+
+err_free_name:
+	kfree(dev->proc_name);
+err_out:
+	return error;
+}
+
+void atm_proc_dev_deregister(struct atm_dev *dev)
+{
+	if (!dev->ops->proc_read)
+		return;
+
+	remove_proc_entry(dev->proc_name, atm_proc_root);
+	kfree(dev->proc_name);
+}
+
+int __init atm_proc_init(void)
+{
+	atm_proc_root = proc_net_mkdir(&init_net, "atm", init_net.proc_net);
+	if (!atm_proc_root)
+		return -ENOMEM;
+	proc_create_seq("devices", 0444, atm_proc_root, &atm_dev_seq_ops);
+	proc_create_seq_private("pvc", 0444, atm_proc_root, &pvc_seq_ops,
+			sizeof(struct vcc_state), (void *)(uintptr_t)PF_ATMPVC);
+	proc_create_seq_private("vc", 0444, atm_proc_root, &vcc_seq_ops,
+			sizeof(struct vcc_state), NULL);
+	return 0;
+}
+
+void atm_proc_exit(void)
+{
+	remove_proc_subtree("atm", init_net.proc_net);
+}
diff --git a/net/atm/protocols.h b/net/atm/protocols.h
new file mode 100644
index 000000000..30158efb5
--- /dev/null
+++ b/net/atm/protocols.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* net/atm/protocols.h - ATM protocol handler entry points */
+
+/* Written 1995-1997 by Werner Almesberger, EPFL LRC */
+
+
+#ifndef NET_ATM_PROTOCOLS_H
+#define NET_ATM_PROTOCOLS_H
+
+int atm_init_aal0(struct atm_vcc *vcc);	/* "raw" AAL0 */
+int atm_init_aal5(struct atm_vcc *vcc);	/* "raw" AAL5 transport */
+
+#endif
diff --git a/net/atm/pvc.c b/net/atm/pvc.c
new file mode 100644
index 000000000..8b2c3e515
--- /dev/null
+++ b/net/atm/pvc.c
@@ -0,0 +1,162 @@
+// SPDX-License-Identifier: GPL-2.0
+/* net/atm/pvc.c - ATM PVC sockets */
+
+/* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
+
+
+#include <linux/net.h>		/* struct socket, struct proto_ops */
+#include <linux/atm.h>		/* ATM stuff */
+#include <linux/atmdev.h>	/* ATM devices */
+#include <linux/errno.h>	/* error codes */
+#include <linux/kernel.h>	/* printk */
+#include <linux/init.h>
+#include <linux/skbuff.h>
+#include <linux/bitops.h>
+#include <linux/export.h>
+#include <net/sock.h>		/* for sock_no_* */
+
+#include "resources.h"		/* devs and vccs */
+#include "common.h"		/* common for PVCs and SVCs */
+
+
+static int pvc_shutdown(struct socket *sock, int how)
+{
+	return 0;
+}
+
+static int pvc_bind(struct socket *sock, struct sockaddr_unsized *sockaddr,
+		    int sockaddr_len)
+{
+	struct sock *sk = sock->sk;
+	struct sockaddr_atmpvc *addr;
+	struct atm_vcc *vcc;
+	int error;
+
+	if (sockaddr_len != sizeof(struct sockaddr_atmpvc))
+		return -EINVAL;
+	addr = (struct sockaddr_atmpvc *)sockaddr;
+	if (addr->sap_family != AF_ATMPVC)
+		return -EAFNOSUPPORT;
+	lock_sock(sk);
+	vcc = ATM_SD(sock);
+	if (!test_bit(ATM_VF_HASQOS, &vcc->flags)) {
+		error = -EBADFD;
+		goto out;
+	}
+	if (test_bit(ATM_VF_PARTIAL, &vcc->flags)) {
+		if (vcc->vpi != ATM_VPI_UNSPEC)
+			addr->sap_addr.vpi = vcc->vpi;
+		if (vcc->vci != ATM_VCI_UNSPEC)
+			addr->sap_addr.vci = vcc->vci;
+	}
+	error = vcc_connect(sock, addr->sap_addr.itf, addr->sap_addr.vpi,
+			    addr->sap_addr.vci);
+out:
+	release_sock(sk);
+	return error;
+}
+
+static int pvc_connect(struct socket *sock, struct sockaddr_unsized *sockaddr,
+		       int sockaddr_len, int flags)
+{
+	return pvc_bind(sock, sockaddr, sockaddr_len);
+}
+
+static int pvc_setsockopt(struct socket *sock, int level, int optname,
+			  sockptr_t optval, unsigned int optlen)
+{
+	struct sock *sk = sock->sk;
+	int error;
+
+	lock_sock(sk);
+	error = vcc_setsockopt(sock, level, optname, optval, optlen);
+	release_sock(sk);
+	return error;
+}
+
+static int pvc_getsockopt(struct socket *sock, int level, int optname,
+			  sockopt_t *opt)
+{
+	struct sock *sk = sock->sk;
+	int error;
+
+	lock_sock(sk);
+	error = vcc_getsockopt(sock, level, optname, opt);
+	release_sock(sk);
+	return error;
+}
+
+static int pvc_getname(struct socket *sock, struct sockaddr *sockaddr,
+		       int peer)
+{
+	struct sockaddr_atmpvc *addr;
+	struct atm_vcc *vcc = ATM_SD(sock);
+
+	if (!vcc->dev || !test_bit(ATM_VF_ADDR, &vcc->flags))
+		return -ENOTCONN;
+	addr = (struct sockaddr_atmpvc *)sockaddr;
+	memset(addr, 0, sizeof(*addr));
+	addr->sap_family = AF_ATMPVC;
+	addr->sap_addr.itf = vcc->dev->number;
+	addr->sap_addr.vpi = vcc->vpi;
+	addr->sap_addr.vci = vcc->vci;
+	return sizeof(struct sockaddr_atmpvc);
+}
+
+static const struct proto_ops pvc_proto_ops = {
+	.family =	PF_ATMPVC,
+	.owner =	THIS_MODULE,
+
+	.release =	vcc_release,
+	.bind =		pvc_bind,
+	.connect =	pvc_connect,
+	.socketpair =	sock_no_socketpair,
+	.accept =	sock_no_accept,
+	.getname =	pvc_getname,
+	.poll =		vcc_poll,
+	.ioctl =	vcc_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = vcc_compat_ioctl,
+#endif
+	.gettstamp =	sock_gettstamp,
+	.listen =	sock_no_listen,
+	.shutdown =	pvc_shutdown,
+	.setsockopt =	pvc_setsockopt,
+	.getsockopt_iter = pvc_getsockopt,
+	.sendmsg =	vcc_sendmsg,
+	.recvmsg =	vcc_recvmsg,
+	.mmap =		sock_no_mmap,
+};
+
+
+static int pvc_create(struct net *net, struct socket *sock, int protocol,
+		      int kern)
+{
+	if (net != &init_net)
+		return -EAFNOSUPPORT;
+
+	sock->ops = &pvc_proto_ops;
+	return vcc_create(net, sock, protocol, PF_ATMPVC, kern);
+}
+
+static const struct net_proto_family pvc_family_ops = {
+	.family = PF_ATMPVC,
+	.create = pvc_create,
+	.owner = THIS_MODULE,
+};
+
+
+/*
+ *	Initialize the ATM PVC protocol family
+ */
+
+
+int __init atmpvc_init(void)
+{
+	return sock_register(&pvc_family_ops);
+}
+
+void atmpvc_exit(void)
+{
+	sock_unregister(PF_ATMPVC);
+}
diff --git a/net/atm/raw.c b/net/atm/raw.c
new file mode 100644
index 000000000..87d136c75
--- /dev/null
+++ b/net/atm/raw.c
@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: GPL-2.0
+/* net/atm/raw.c - Raw AAL0 and AAL5 transports */
+
+/* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
+
+#include <linux/module.h>
+#include <linux/atmdev.h>
+#include <linux/capability.h>
+#include <linux/kernel.h>
+#include <linux/skbuff.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+
+#include "common.h"
+#include "protocols.h"
+
+/*
+ * SKB == NULL indicates that the link is being closed
+ */
+
+static void atm_push_raw(struct atm_vcc *vcc, struct sk_buff *skb)
+{
+	if (skb) {
+		struct sock *sk = sk_atm(vcc);
+
+		skb_queue_tail(&sk->sk_receive_queue, skb);
+		sk->sk_data_ready(sk);
+	}
+}
+
+static void atm_pop_raw(struct atm_vcc *vcc, struct sk_buff *skb)
+{
+	struct sock *sk = sk_atm(vcc);
+
+	pr_debug("(%d) %d -= %d\n",
+		 vcc->vci, sk_wmem_alloc_get(sk), ATM_SKB(skb)->acct_truesize);
+	atm_return_tx(vcc, skb);
+	dev_kfree_skb_any(skb);
+	sk->sk_write_space(sk);
+}
+
+static int atm_send_aal0(struct atm_vcc *vcc, struct sk_buff *skb)
+{
+	/*
+	 * Note that if vpi/vci are _ANY or _UNSPEC the below will
+	 * still work
+	 */
+	if (!capable(CAP_NET_ADMIN) &&
+	    (((u32 *)skb->data)[0] & (ATM_HDR_VPI_MASK | ATM_HDR_VCI_MASK)) !=
+	    ((vcc->vpi << ATM_HDR_VPI_SHIFT) |
+	     (vcc->vci << ATM_HDR_VCI_SHIFT))) {
+		kfree_skb(skb);
+		return -EADDRNOTAVAIL;
+	}
+	return vcc->dev->ops->send(vcc, skb);
+}
+
+int atm_init_aal0(struct atm_vcc *vcc)
+{
+	vcc->push = atm_push_raw;
+	vcc->pop = atm_pop_raw;
+	vcc->send = atm_send_aal0;
+	return 0;
+}
+
+int atm_init_aal5(struct atm_vcc *vcc)
+{
+	vcc->push = atm_push_raw;
+	vcc->pop = atm_pop_raw;
+	vcc->send = vcc->dev->ops->send;
+	return 0;
+}
+EXPORT_SYMBOL(atm_init_aal5);
diff --git a/net/atm/resources.c b/net/atm/resources.c
new file mode 100644
index 000000000..d94dc8221
--- /dev/null
+++ b/net/atm/resources.c
@@ -0,0 +1,363 @@
+// SPDX-License-Identifier: GPL-2.0
+/* net/atm/resources.c - Statically allocated resources */
+
+/* Written 1995-2000 by Werner Almesberger, EPFL LRC/ICA */
+
+/* Fixes
+ * Arnaldo Carvalho de Melo <acme@conectiva.com.br>
+ * 2002/01 - don't free the whole struct sock on sk->destruct time,
+ * 	     use the default destruct function initialized by sock_init_data */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":%s: " fmt, __func__
+
+#include <linux/ctype.h>
+#include <linux/string.h>
+#include <linux/atmdev.h>
+#include <linux/kernel.h> /* for barrier */
+#include <linux/module.h>
+#include <linux/bitops.h>
+#include <linux/capability.h>
+#include <linux/delay.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+
+#include <net/sock.h>	 /* for struct sock */
+
+#include "common.h"
+#include "resources.h"
+
+
+LIST_HEAD(atm_devs);
+DEFINE_MUTEX(atm_dev_mutex);
+
+static struct atm_dev *__alloc_atm_dev(const char *type)
+{
+	struct atm_dev *dev;
+
+	dev = kzalloc_obj(*dev);
+	if (!dev)
+		return NULL;
+	dev->type = type;
+	dev->signal = ATM_PHY_SIG_UNKNOWN;
+	dev->link_rate = ATM_OC3_PCR;
+
+	return dev;
+}
+
+static struct atm_dev *__atm_dev_lookup(int number)
+{
+	struct atm_dev *dev;
+
+	list_for_each_entry(dev, &atm_devs, dev_list) {
+		if (dev->number == number) {
+			atm_dev_hold(dev);
+			return dev;
+		}
+	}
+	return NULL;
+}
+
+struct atm_dev *atm_dev_lookup(int number)
+{
+	struct atm_dev *dev;
+
+	mutex_lock(&atm_dev_mutex);
+	dev = __atm_dev_lookup(number);
+	mutex_unlock(&atm_dev_mutex);
+	return dev;
+}
+EXPORT_SYMBOL(atm_dev_lookup);
+
+struct atm_dev *atm_dev_register(const char *type, struct device *parent,
+				 const struct atmdev_ops *ops, int number,
+				 unsigned long *flags)
+{
+	struct atm_dev *dev, *inuse;
+
+	dev = __alloc_atm_dev(type);
+	if (!dev) {
+		pr_err("no space for dev %s\n", type);
+		return NULL;
+	}
+	mutex_lock(&atm_dev_mutex);
+	if (number != -1) {
+		inuse = __atm_dev_lookup(number);
+		if (inuse) {
+			atm_dev_put(inuse);
+			mutex_unlock(&atm_dev_mutex);
+			kfree(dev);
+			return NULL;
+		}
+		dev->number = number;
+	} else {
+		dev->number = 0;
+		while ((inuse = __atm_dev_lookup(dev->number))) {
+			atm_dev_put(inuse);
+			dev->number++;
+		}
+	}
+
+	dev->ops = ops;
+	if (flags)
+		dev->flags = *flags;
+	else
+		memset(&dev->flags, 0, sizeof(dev->flags));
+	memset(&dev->stats, 0, sizeof(dev->stats));
+	refcount_set(&dev->refcnt, 1);
+
+	if (atm_proc_dev_register(dev) < 0) {
+		pr_err("atm_proc_dev_register failed for dev %s\n", type);
+		mutex_unlock(&atm_dev_mutex);
+		kfree(dev);
+		return NULL;
+	}
+
+	if (atm_register_sysfs(dev, parent) < 0) {
+		pr_err("atm_register_sysfs failed for dev %s\n", type);
+		atm_proc_dev_deregister(dev);
+		goto out_fail;
+	}
+
+	list_add_tail(&dev->dev_list, &atm_devs);
+
+out:
+	mutex_unlock(&atm_dev_mutex);
+	return dev;
+
+out_fail:
+	put_device(&dev->class_dev);
+	dev = NULL;
+	goto out;
+}
+EXPORT_SYMBOL(atm_dev_register);
+
+void atm_dev_deregister(struct atm_dev *dev)
+{
+	BUG_ON(test_bit(ATM_DF_REMOVED, &dev->flags));
+	set_bit(ATM_DF_REMOVED, &dev->flags);
+
+	/*
+	 * if we remove current device from atm_devs list, new device
+	 * with same number can appear, such we need deregister proc,
+	 * release async all vccs and remove them from vccs list too
+	 */
+	mutex_lock(&atm_dev_mutex);
+	list_del(&dev->dev_list);
+	atm_dev_release_vccs(dev);
+	atm_unregister_sysfs(dev);
+	atm_proc_dev_deregister(dev);
+	mutex_unlock(&atm_dev_mutex);
+
+	atm_dev_put(dev);
+}
+EXPORT_SYMBOL(atm_dev_deregister);
+
+static void copy_aal_stats(struct k_atm_aal_stats *from,
+    struct atm_aal_stats *to)
+{
+#define __HANDLE_ITEM(i) to->i = atomic_read(&from->i)
+	__AAL_STAT_ITEMS
+#undef __HANDLE_ITEM
+}
+
+static void subtract_aal_stats(struct k_atm_aal_stats *from,
+    struct atm_aal_stats *to)
+{
+#define __HANDLE_ITEM(i) atomic_sub(to->i, &from->i)
+	__AAL_STAT_ITEMS
+#undef __HANDLE_ITEM
+}
+
+static int fetch_stats(struct atm_dev *dev, struct atm_dev_stats __user *arg,
+		       int zero)
+{
+	struct atm_dev_stats tmp;
+	int error = 0;
+
+	copy_aal_stats(&dev->stats.aal0, &tmp.aal0);
+	copy_aal_stats(&dev->stats.aal34, &tmp.aal34);
+	copy_aal_stats(&dev->stats.aal5, &tmp.aal5);
+	if (arg)
+		error = copy_to_user(arg, &tmp, sizeof(tmp));
+	if (zero && !error) {
+		subtract_aal_stats(&dev->stats.aal0, &tmp.aal0);
+		subtract_aal_stats(&dev->stats.aal34, &tmp.aal34);
+		subtract_aal_stats(&dev->stats.aal5, &tmp.aal5);
+	}
+	return error ? -EFAULT : 0;
+}
+
+int atm_getnames(void __user *buf, int __user *iobuf_len)
+{
+	int error, len, size = 0;
+	struct atm_dev *dev;
+	struct list_head *p;
+	int *tmp_buf, *tmp_p;
+
+	if (get_user(len, iobuf_len))
+		return -EFAULT;
+	mutex_lock(&atm_dev_mutex);
+	list_for_each(p, &atm_devs)
+		size += sizeof(int);
+	if (size > len) {
+		mutex_unlock(&atm_dev_mutex);
+		return -E2BIG;
+	}
+	tmp_buf = kmalloc(size, GFP_ATOMIC);
+	if (!tmp_buf) {
+		mutex_unlock(&atm_dev_mutex);
+		return -ENOMEM;
+	}
+	tmp_p = tmp_buf;
+	list_for_each_entry(dev, &atm_devs, dev_list) {
+		*tmp_p++ = dev->number;
+	}
+	mutex_unlock(&atm_dev_mutex);
+	error = ((copy_to_user(buf, tmp_buf, size)) ||
+		 put_user(size, iobuf_len))
+		? -EFAULT : 0;
+	kfree(tmp_buf);
+	return error;
+}
+
+int atm_dev_ioctl(unsigned int cmd, void __user *buf, int __user *sioc_len,
+		  int number, int compat)
+{
+	struct atm_dev *dev;
+	int error, size = 0;
+
+	dev = try_then_request_module(atm_dev_lookup(number), "atm-device-%d",
+				      number);
+	if (!dev)
+		return -ENODEV;
+
+	switch (cmd) {
+	case ATM_GETTYPE:
+		size = strlen(dev->type) + 1;
+		if (copy_to_user(buf, dev->type, size)) {
+			error = -EFAULT;
+			goto done;
+		}
+		break;
+	case ATM_GETESI:
+		size = ESI_LEN;
+		if (copy_to_user(buf, dev->esi, size)) {
+			error = -EFAULT;
+			goto done;
+		}
+		break;
+	case ATM_SETESI:
+	{
+		int i;
+
+		for (i = 0; i < ESI_LEN; i++)
+			if (dev->esi[i]) {
+				error = -EEXIST;
+				goto done;
+			}
+	}
+		fallthrough;
+	case ATM_SETESIF:
+	{
+		unsigned char esi[ESI_LEN];
+
+		if (!capable(CAP_NET_ADMIN)) {
+			error = -EPERM;
+			goto done;
+		}
+		if (copy_from_user(esi, buf, ESI_LEN)) {
+			error = -EFAULT;
+			goto done;
+		}
+		memcpy(dev->esi, esi, ESI_LEN);
+		error =  ESI_LEN;
+		goto done;
+	}
+	case ATM_GETSTATZ:
+		if (!capable(CAP_NET_ADMIN)) {
+			error = -EPERM;
+			goto done;
+		}
+		fallthrough;
+	case ATM_GETSTAT:
+		size = sizeof(struct atm_dev_stats);
+		error = fetch_stats(dev, buf, cmd == ATM_GETSTATZ);
+		if (error)
+			goto done;
+		break;
+	case ATM_GETCIRANGE:
+		size = sizeof(struct atm_cirange);
+		if (copy_to_user(buf, &dev->ci_range, size)) {
+			error = -EFAULT;
+			goto done;
+		}
+		break;
+	case ATM_GETLINKRATE:
+		size = sizeof(int);
+		if (copy_to_user(buf, &dev->link_rate, size)) {
+			error = -EFAULT;
+			goto done;
+		}
+		break;
+	case ATM_SETLOOP:
+		if (__ATM_LM_XTRMT((int) (unsigned long) buf) &&
+		    __ATM_LM_XTLOC((int) (unsigned long) buf) >
+		    __ATM_LM_XTRMT((int) (unsigned long) buf)) {
+			error = -EINVAL;
+			goto done;
+		}
+		fallthrough;
+	case ATM_SETCIRANGE:
+		if (!capable(CAP_NET_ADMIN)) {
+			error = -EPERM;
+			goto done;
+		}
+		fallthrough;
+	default:
+		if (IS_ENABLED(CONFIG_COMPAT) && compat) {
+#ifdef CONFIG_COMPAT
+			if (!dev->ops->compat_ioctl) {
+				error = -EINVAL;
+				goto done;
+			}
+			size = dev->ops->compat_ioctl(dev, cmd, buf);
+#endif
+		} else {
+			if (!dev->ops->ioctl) {
+				error = -EINVAL;
+				goto done;
+			}
+			size = dev->ops->ioctl(dev, cmd, buf);
+		}
+		if (size < 0) {
+			error = (size == -ENOIOCTLCMD ? -ENOTTY : size);
+			goto done;
+		}
+	}
+
+	if (size)
+		error = put_user(size, sioc_len) ? -EFAULT : 0;
+	else
+		error = 0;
+done:
+	atm_dev_put(dev);
+	return error;
+}
+
+#ifdef CONFIG_PROC_FS
+void *atm_dev_seq_start(struct seq_file *seq, loff_t *pos)
+{
+	mutex_lock(&atm_dev_mutex);
+	return seq_list_start_head(&atm_devs, *pos);
+}
+
+void atm_dev_seq_stop(struct seq_file *seq, void *v)
+{
+	mutex_unlock(&atm_dev_mutex);
+}
+
+void *atm_dev_seq_next(struct seq_file *seq, void *v, loff_t *pos)
+{
+	return seq_list_next(v, &atm_devs, pos);
+}
+#endif
diff --git a/net/atm/resources.h b/net/atm/resources.h
new file mode 100644
index 000000000..4a0839e92
--- /dev/null
+++ b/net/atm/resources.h
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* net/atm/resources.h - ATM-related resources */
+
+/* Written 1995-1998 by Werner Almesberger, EPFL LRC/ICA */
+
+
+#ifndef NET_ATM_RESOURCES_H
+#define NET_ATM_RESOURCES_H
+
+#include <linux/atmdev.h>
+#include <linux/mutex.h>
+
+
+extern struct list_head atm_devs;
+extern struct mutex atm_dev_mutex;
+
+int atm_getnames(void __user *buf, int __user *iobuf_len);
+int atm_dev_ioctl(unsigned int cmd, void __user *buf, int __user *sioc_len,
+		  int number, int compat);
+
+#ifdef CONFIG_PROC_FS
+
+#include <linux/proc_fs.h>
+
+void *atm_dev_seq_start(struct seq_file *seq, loff_t *pos);
+void atm_dev_seq_stop(struct seq_file *seq, void *v);
+void *atm_dev_seq_next(struct seq_file *seq, void *v, loff_t *pos);
+
+
+int atm_proc_dev_register(struct atm_dev *dev);
+void atm_proc_dev_deregister(struct atm_dev *dev);
+
+#else
+
+static inline int atm_proc_dev_register(struct atm_dev *dev)
+{
+	return 0;
+}
+
+static inline void atm_proc_dev_deregister(struct atm_dev *dev)
+{
+	/* nothing */
+}
+
+#endif /* CONFIG_PROC_FS */
+
+int atm_register_sysfs(struct atm_dev *adev, struct device *parent);
+void atm_unregister_sysfs(struct atm_dev *adev);
+#endif