v4.19.13 snapshot.
diff --git a/net/ax25/ax25_iface.c b/net/ax25/ax25_iface.c
new file mode 100644
index 0000000..8c07c28
--- /dev/null
+++ b/net/ax25/ax25_iface.c
@@ -0,0 +1,217 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
+ */
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/in.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/spinlock.h>
+#include <linux/timer.h>
+#include <linux/string.h>
+#include <linux/sockios.h>
+#include <linux/net.h>
+#include <linux/slab.h>
+#include <net/ax25.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <linux/uaccess.h>
+#include <linux/fcntl.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+
+static struct ax25_protocol *protocol_list;
+static DEFINE_RWLOCK(protocol_list_lock);
+
+static HLIST_HEAD(ax25_linkfail_list);
+static DEFINE_SPINLOCK(linkfail_lock);
+
+static struct listen_struct {
+ struct listen_struct *next;
+ ax25_address callsign;
+ struct net_device *dev;
+} *listen_list = NULL;
+static DEFINE_SPINLOCK(listen_lock);
+
+/*
+ * Do not register the internal protocols AX25_P_TEXT, AX25_P_SEGMENT,
+ * AX25_P_IP or AX25_P_ARP ...
+ */
+void ax25_register_pid(struct ax25_protocol *ap)
+{
+ write_lock_bh(&protocol_list_lock);
+ ap->next = protocol_list;
+ protocol_list = ap;
+ write_unlock_bh(&protocol_list_lock);
+}
+
+EXPORT_SYMBOL_GPL(ax25_register_pid);
+
+void ax25_protocol_release(unsigned int pid)
+{
+ struct ax25_protocol *protocol;
+
+ write_lock_bh(&protocol_list_lock);
+ protocol = protocol_list;
+ if (protocol == NULL)
+ goto out;
+
+ if (protocol->pid == pid) {
+ protocol_list = protocol->next;
+ goto out;
+ }
+
+ while (protocol != NULL && protocol->next != NULL) {
+ if (protocol->next->pid == pid) {
+ protocol->next = protocol->next->next;
+ goto out;
+ }
+
+ protocol = protocol->next;
+ }
+out:
+ write_unlock_bh(&protocol_list_lock);
+}
+
+EXPORT_SYMBOL(ax25_protocol_release);
+
+void ax25_linkfail_register(struct ax25_linkfail *lf)
+{
+ spin_lock_bh(&linkfail_lock);
+ hlist_add_head(&lf->lf_node, &ax25_linkfail_list);
+ spin_unlock_bh(&linkfail_lock);
+}
+
+EXPORT_SYMBOL(ax25_linkfail_register);
+
+void ax25_linkfail_release(struct ax25_linkfail *lf)
+{
+ spin_lock_bh(&linkfail_lock);
+ hlist_del_init(&lf->lf_node);
+ spin_unlock_bh(&linkfail_lock);
+}
+
+EXPORT_SYMBOL(ax25_linkfail_release);
+
+int ax25_listen_register(ax25_address *callsign, struct net_device *dev)
+{
+ struct listen_struct *listen;
+
+ if (ax25_listen_mine(callsign, dev))
+ return 0;
+
+ if ((listen = kmalloc(sizeof(*listen), GFP_ATOMIC)) == NULL)
+ return -ENOMEM;
+
+ listen->callsign = *callsign;
+ listen->dev = dev;
+
+ spin_lock_bh(&listen_lock);
+ listen->next = listen_list;
+ listen_list = listen;
+ spin_unlock_bh(&listen_lock);
+
+ return 0;
+}
+
+EXPORT_SYMBOL(ax25_listen_register);
+
+void ax25_listen_release(ax25_address *callsign, struct net_device *dev)
+{
+ struct listen_struct *s, *listen;
+
+ spin_lock_bh(&listen_lock);
+ listen = listen_list;
+ if (listen == NULL) {
+ spin_unlock_bh(&listen_lock);
+ return;
+ }
+
+ if (ax25cmp(&listen->callsign, callsign) == 0 && listen->dev == dev) {
+ listen_list = listen->next;
+ spin_unlock_bh(&listen_lock);
+ kfree(listen);
+ return;
+ }
+
+ while (listen != NULL && listen->next != NULL) {
+ if (ax25cmp(&listen->next->callsign, callsign) == 0 && listen->next->dev == dev) {
+ s = listen->next;
+ listen->next = listen->next->next;
+ spin_unlock_bh(&listen_lock);
+ kfree(s);
+ return;
+ }
+
+ listen = listen->next;
+ }
+ spin_unlock_bh(&listen_lock);
+}
+
+EXPORT_SYMBOL(ax25_listen_release);
+
+int (*ax25_protocol_function(unsigned int pid))(struct sk_buff *, ax25_cb *)
+{
+ int (*res)(struct sk_buff *, ax25_cb *) = NULL;
+ struct ax25_protocol *protocol;
+
+ read_lock(&protocol_list_lock);
+ for (protocol = protocol_list; protocol != NULL; protocol = protocol->next)
+ if (protocol->pid == pid) {
+ res = protocol->func;
+ break;
+ }
+ read_unlock(&protocol_list_lock);
+
+ return res;
+}
+
+int ax25_listen_mine(ax25_address *callsign, struct net_device *dev)
+{
+ struct listen_struct *listen;
+
+ spin_lock_bh(&listen_lock);
+ for (listen = listen_list; listen != NULL; listen = listen->next)
+ if (ax25cmp(&listen->callsign, callsign) == 0 &&
+ (listen->dev == dev || listen->dev == NULL)) {
+ spin_unlock_bh(&listen_lock);
+ return 1;
+ }
+ spin_unlock_bh(&listen_lock);
+
+ return 0;
+}
+
+void ax25_link_failed(ax25_cb *ax25, int reason)
+{
+ struct ax25_linkfail *lf;
+
+ spin_lock_bh(&linkfail_lock);
+ hlist_for_each_entry(lf, &ax25_linkfail_list, lf_node)
+ lf->func(ax25, reason);
+ spin_unlock_bh(&linkfail_lock);
+}
+
+int ax25_protocol_is_registered(unsigned int pid)
+{
+ struct ax25_protocol *protocol;
+ int res = 0;
+
+ read_lock_bh(&protocol_list_lock);
+ for (protocol = protocol_list; protocol != NULL; protocol = protocol->next)
+ if (protocol->pid == pid) {
+ res = 1;
+ break;
+ }
+ read_unlock_bh(&protocol_list_lock);
+
+ return res;
+}