linux/net/l2tp/l2tp_debugfs.c
Greg Kroah-Hartman 3adcfa4478 l2tp: no need to check return value of debugfs_create functions
When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Also, there is no need to store the individual debugfs file name, just
remove the whole directory all at once, saving a local variable.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Guillaume Nault <g.nault@alphalink.fr>
Cc: netdev@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-14 08:45:05 -07:00

349 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;
int tunnel_idx; /* current tunnel */
int session_idx; /* index of session within current tunnel */
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_dec_refcount(pd->tunnel);
pd->tunnel = l2tp_tunnel_get_nth(pd->net, pd->tunnel_idx);
pd->tunnel_idx++;
}
static void l2tp_dfs_next_session(struct l2tp_dfs_seq_data *pd)
{
/* Drop reference taken during previous invocation */
if (pd->session)
l2tp_session_dec_refcount(pd->session);
pd->session = l2tp_session_get_nth(pd->tunnel, pd->session_idx);
pd->session_idx++;
if (pd->session == NULL) {
pd->session_idx = 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;
BUG_ON(m->private == NULL);
pd = m->private;
if (pd->tunnel == NULL)
l2tp_dfs_next_tunnel(pd);
else
l2tp_dfs_next_session(pd);
/* NULL tunnel and session indicates end of list */
if ((pd->tunnel == NULL) && (pd->session == NULL))
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_dec_refcount(pd->session);
pd->session = NULL;
}
if (pd->tunnel) {
l2tp_tunnel_dec_refcount(pd->tunnel);
pd->tunnel = NULL;
}
}
static void l2tp_dfs_seq_tunnel_show(struct seq_file *m, void *v)
{
struct l2tp_tunnel *tunnel = v;
int session_count = 0;
int hash;
struct hlist_node *walk;
struct hlist_node *tmp;
read_lock_bh(&tunnel->hlist_lock);
for (hash = 0; hash < L2TP_HASH_SIZE; hash++) {
hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) {
struct l2tp_session *session;
session = hlist_entry(walk, struct l2tp_session, hlist);
if (session->session_id == 0)
continue;
session_count++;
}
}
read_unlock_bh(&tunnel->hlist_lock);
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);
} else
#endif
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",
tunnel->debug,
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 %hu, ns %hu\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",
session->debug,
jiffies_to_msecs(session->reorder_timeout));
seq_printf(m, " offset 0 l2specific %hu/%hu\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_printf(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_printf(m, "\n");
}
seq_printf(m, " %hu/%hu 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 != NULL)
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 == NULL)
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;
}
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(pd->net);
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(pd->net);
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");