linux/net/l2tp/l2tp_debugfs.c
James Chapman abe7a1a7d0 l2tp: improve tunnel/session refcount helpers
l2tp_tunnel_inc_refcount and l2tp_session_inc_refcount wrap
refcount_inc. They add no value so just use the refcount APIs directly
and drop l2tp's helpers. l2tp already uses refcount_inc_not_zero
anyway.

Rename l2tp_tunnel_dec_refcount and l2tp_session_dec_refcount to
l2tp_tunnel_put and l2tp_session_put to better match their use pairing
various _get getters.

Signed-off-by: James Chapman <jchapman@katalix.com>
Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-08-11 04:38:50 +01:00

348 lines
9.0 KiB
C

// 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 rx %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(sizeof(*pd), GFP_KERNEL);
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->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");