// SPDX-License-Identifier: GPL-2.0-or-later/* L2TP subsystem debugfs * * Copyright (c) 2010 Katalix Systems Ltd */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/module.h>#include <linux/skbuff.h>#include <linux/socket.h>#include <linux/hash.h>#include <linux/l2tp.h>#include <linux/in.h>#include <linux/etherdevice.h>#include <linux/spinlock.h>#include <linux/debugfs.h>#include <net/sock.h>#include <net/ip.h>#include <net/icmp.h>#include <net/udp.h>#include <net/inet_common.h>#include <net/inet_hashtables.h>#include <net/tcp_states.h>#include <net/protocol.h>#include <net/xfrm.h>#include <net/net_namespace.h>#include <net/netns/generic.h> #include "l2tp_core.h" static struct dentry *rootdir; struct l2tp_dfs_seq_data {	struct net	*net;	netns_tracker	ns_tracker;	unsigned long tkey;		/* lookup key of current tunnel */	unsigned long skey;		/* lookup key of current session */	struct l2tp_tunnel *tunnel;	struct l2tp_session *session;	/* NULL means get next tunnel */}; static void l2tp_dfs_next_tunnel(struct l2tp_dfs_seq_data *pd){	/* Drop reference taken during previous invocation */	if (pd->tunnel)		l2tp_tunnel_put(pd->tunnel); 	pd->tunnel = l2tp_tunnel_get_next(pd->net, &pd->tkey);	pd->tkey++;} static void l2tp_dfs_next_session(struct l2tp_dfs_seq_data *pd){	/* Drop reference taken during previous invocation */	if (pd->session)		l2tp_session_put(pd->session); 	pd->session = l2tp_session_get_next(pd->net, pd->tunnel->sock,					    pd->tunnel->version,					    pd->tunnel->tunnel_id, &pd->skey);	pd->skey++; 	if (!pd->session) {		pd->skey = 0;		l2tp_dfs_next_tunnel(pd);	}} static void *l2tp_dfs_seq_start(struct seq_file *m, loff_t *offs){	struct l2tp_dfs_seq_data *pd = SEQ_START_TOKEN;	loff_t pos = *offs; 	if (!pos)		goto out; 	if (WARN_ON(!m->private)) {		pd = NULL;		goto out;	}	pd = m->private; 	if (!pd->tunnel)		l2tp_dfs_next_tunnel(pd);	else		l2tp_dfs_next_session(pd); 	/* NULL tunnel and session indicates end of list */	if (!pd->tunnel && !pd->session)		pd = NULL; out:	return pd;} static void *l2tp_dfs_seq_next(struct seq_file *m, void *v, loff_t *pos){	(*pos)++;	return NULL;} static void l2tp_dfs_seq_stop(struct seq_file *p, void *v){	struct l2tp_dfs_seq_data *pd = v; 	if (!pd || pd == SEQ_START_TOKEN)		return; 	/* Drop reference taken by last invocation of l2tp_dfs_next_session()	 * or l2tp_dfs_next_tunnel().	 */	if (pd->session) {		l2tp_session_put(pd->session);		pd->session = NULL;	}	if (pd->tunnel) {		l2tp_tunnel_put(pd->tunnel);		pd->tunnel = NULL;	}} static void l2tp_dfs_seq_tunnel_show(struct seq_file *m, void *v){	struct l2tp_tunnel *tunnel = v;	struct l2tp_session *session;	int session_count = 0; 	rcu_read_lock_bh();	list_for_each_entry_rcu(session, &tunnel->session_list, list) {		/* Session ID of zero is a dummy/reserved value used by pppol2tp */		if (session->session_id == 0)			continue; 		session_count++;	}	rcu_read_unlock_bh(); 	seq_printf(m, "\nTUNNEL %u peer %u", tunnel->tunnel_id, tunnel->peer_tunnel_id);	if (tunnel->sock) {		struct inet_sock *inet = inet_sk(tunnel->sock); #if IS_ENABLED(CONFIG_IPV6)		if (tunnel->sock->sk_family == AF_INET6) {			const struct ipv6_pinfo *np = inet6_sk(tunnel->sock); 			seq_printf(m, " from %pI6c to %pI6c\n",				   &np->saddr, &tunnel->sock->sk_v6_daddr);		}#endif		if (tunnel->sock->sk_family == AF_INET)			seq_printf(m, " from %pI4 to %pI4\n",				   &inet->inet_saddr, &inet->inet_daddr); 		if (tunnel->encap == L2TP_ENCAPTYPE_UDP)			seq_printf(m, " source port %hu, dest port %hu\n",				   ntohs(inet->inet_sport), ntohs(inet->inet_dport));	}	seq_printf(m, " L2TPv%d, %s\n", tunnel->version,		   tunnel->encap == L2TP_ENCAPTYPE_UDP ? "UDP" :		   tunnel->encap == L2TP_ENCAPTYPE_IP ? "IP" :		   "");	seq_printf(m, " %d sessions, refcnt %d/%d\n", session_count,		   tunnel->sock ? refcount_read(&tunnel->sock->sk_refcnt) : 0,		   refcount_read(&tunnel->ref_count));	seq_printf(m, " %08x tx %ld/%ld/%ld rx %ld/%ld/%ld\n",		   0,		   atomic_long_read(&tunnel->stats.tx_packets),		   atomic_long_read(&tunnel->stats.tx_bytes),		   atomic_long_read(&tunnel->stats.tx_errors),		   atomic_long_read(&tunnel->stats.rx_packets),		   atomic_long_read(&tunnel->stats.rx_bytes),		   atomic_long_read(&tunnel->stats.rx_errors));} static void l2tp_dfs_seq_session_show(struct seq_file *m, void *v){	struct l2tp_session *session = v; 	seq_printf(m, "  SESSION %u, peer %u, %s\n", session->session_id,		   session->peer_session_id,		   session->pwtype == L2TP_PWTYPE_ETH ? "ETH" :		   session->pwtype == L2TP_PWTYPE_PPP ? "PPP" :		   "");	if (session->send_seq || session->recv_seq)		seq_printf(m, "   nr %u, ns %u\n", session->nr, session->ns);	seq_printf(m, "   refcnt %d\n", refcount_read(&session->ref_count));	seq_printf(m, "   config 0/0/%c/%c/-/%s %08x %u\n",		   session->recv_seq ? 'R' : '-',		   session->send_seq ? 'S' : '-',		   session->lns_mode ? "LNS" : "LAC",		   0,		   jiffies_to_msecs(session->reorder_timeout));	seq_printf(m, "   offset 0 l2specific %hu/%d\n",		   session->l2specific_type, l2tp_get_l2specific_len(session));	if (session->cookie_len) {		seq_printf(m, "   cookie %02x%02x%02x%02x",			   session->cookie[0], session->cookie[1],			   session->cookie[2], session->cookie[3]);		if (session->cookie_len == 8)			seq_printf(m, "%02x%02x%02x%02x",				   session->cookie[4], session->cookie[5],				   session->cookie[6], session->cookie[7]);		seq_puts(m, "\n");	}	if (session->peer_cookie_len) {		seq_printf(m, "   peer cookie %02x%02x%02x%02x",			   session->peer_cookie[0], session->peer_cookie[1],			   session->peer_cookie[2], session->peer_cookie[3]);		if (session->peer_cookie_len == 8)			seq_printf(m, "%02x%02x%02x%02x",				   session->peer_cookie[4], session->peer_cookie[5],				   session->peer_cookie[6], session->peer_cookie[7]);		seq_puts(m, "\n");	} 	seq_printf(m, "   %u/%u tx %ld/%ld/%ld rx %ld/%ld/%ld\n",		   session->nr, session->ns,		   atomic_long_read(&session->stats.tx_packets),		   atomic_long_read(&session->stats.tx_bytes),		   atomic_long_read(&session->stats.tx_errors),		   atomic_long_read(&session->stats.rx_packets),		   atomic_long_read(&session->stats.rx_bytes),		   atomic_long_read(&session->stats.rx_errors)); 	if (session->show)		session->show(m, session);} static int l2tp_dfs_seq_show(struct seq_file *m, void *v){	struct l2tp_dfs_seq_data *pd = v; 	/* display header on line 1 */	if (v == SEQ_START_TOKEN) {		seq_puts(m, "TUNNEL ID, peer ID from IP to IP\n");		seq_puts(m, " L2TPv2/L2TPv3, UDP/IP\n");		seq_puts(m, " sessions session-count, refcnt refcnt/sk->refcnt\n");		seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");		seq_puts(m, "  SESSION ID, peer ID, PWTYPE\n");		seq_puts(m, "   refcnt cnt\n");		seq_puts(m, "   offset OFFSET l2specific TYPE/LEN\n");		seq_puts(m, "   [ cookie ]\n");		seq_puts(m, "   [ peer cookie ]\n");		seq_puts(m, "   config mtu/mru/rcvseq/sendseq/dataseq/lns debug reorderto\n");		seq_puts(m, "   nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");		goto out;	} 	if (!pd->session)		l2tp_dfs_seq_tunnel_show(m, pd->tunnel);	else		l2tp_dfs_seq_session_show(m, pd->session); out:	return 0;} static const struct seq_operations l2tp_dfs_seq_ops = {	.start		= l2tp_dfs_seq_start,	.next		= l2tp_dfs_seq_next,	.stop		= l2tp_dfs_seq_stop,	.show		= l2tp_dfs_seq_show,}; static int l2tp_dfs_seq_open(struct inode *inode, struct file *file){	struct l2tp_dfs_seq_data *pd;	struct seq_file *seq;	int rc = -ENOMEM; 	pd = kzalloc_obj(*pd);	if (!pd)		goto out; 	/* Derive the network namespace from the pid opening the	 * file.	 */	pd->net = get_net_ns_by_pid(current->pid);	if (IS_ERR(pd->net)) {		rc = PTR_ERR(pd->net);		goto err_free_pd;	}	netns_tracker_alloc(pd->net, &pd->ns_tracker, GFP_KERNEL);	rc = seq_open(file, &l2tp_dfs_seq_ops);	if (rc)		goto err_free_net; 	seq = file->private_data;	seq->private = pd; out:	return rc; err_free_net:	put_net_track(pd->net, &pd->ns_tracker);err_free_pd:	kfree(pd);	goto out;} static int l2tp_dfs_seq_release(struct inode *inode, struct file *file){	struct l2tp_dfs_seq_data *pd;	struct seq_file *seq; 	seq = file->private_data;	pd = seq->private;	if (pd->session)		l2tp_session_put(pd->session);	if (pd->tunnel)		l2tp_tunnel_put(pd->tunnel);	if (pd->net)		put_net_track(pd->net, &pd->ns_tracker);	kfree(pd);	seq_release(inode, file); 	return 0;} static const struct file_operations l2tp_dfs_fops = {	.owner		= THIS_MODULE,	.open		= l2tp_dfs_seq_open,	.read		= seq_read,	.llseek		= seq_lseek,	.release	= l2tp_dfs_seq_release,}; static int __init l2tp_debugfs_init(void){	rootdir = debugfs_create_dir("l2tp", NULL); 	debugfs_create_file("tunnels", 0600, rootdir, NULL, &l2tp_dfs_fops); 	pr_info("L2TP debugfs support\n"); 	return 0;} static void __exit l2tp_debugfs_exit(void){	debugfs_remove_recursive(rootdir);} module_init(l2tp_debugfs_init);module_exit(l2tp_debugfs_exit); MODULE_LICENSE("GPL");MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");MODULE_DESCRIPTION("L2TP debugfs driver");MODULE_VERSION("1.0");