// 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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) { 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); 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_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); } #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", 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_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, " %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) 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; } 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 "); MODULE_DESCRIPTION("L2TP debugfs driver"); MODULE_VERSION("1.0");