From 0ad6614048cf722e4d27909665b4846805357f1b Mon Sep 17 00:00:00 2001 From: James Chapman Date: Fri, 2 Apr 2010 06:19:33 +0000 Subject: [PATCH] l2tp: Add debugfs files for dumping l2tp debug info The existing pppol2tp driver exports debug info to /proc/net/pppol2tp. Rather than adding info to that file for the new functionality added in this patch series, we add new files in debugfs, leaving the old /proc file for backwards compatibility (L2TPv2 only). Currently only one file is provided: l2tp/tunnels, which lists internal debug info for all l2tp tunnels and sessions. More files may be added later. The info is for debug and problem analysis only - userspace apps should use netlink to obtain status about l2tp tunnels and sessions. Although debugfs does not support net namespaces, the tunnels and sessions dumped in l2tp/tunnels are only those in the net namespace of the process reading the file. Signed-off-by: James Chapman Signed-off-by: David S. Miller --- net/l2tp/Kconfig | 13 ++ net/l2tp/Makefile | 1 + net/l2tp/l2tp_core.h | 8 +- net/l2tp/l2tp_debugfs.c | 341 ++++++++++++++++++++++++++++++++++++++++ net/l2tp/l2tp_eth.c | 14 ++ net/l2tp/l2tp_ppp.c | 17 ++ 6 files changed, 392 insertions(+), 2 deletions(-) create mode 100644 net/l2tp/l2tp_debugfs.c diff --git a/net/l2tp/Kconfig b/net/l2tp/Kconfig index a292270c0abe..4b1e71751e10 100644 --- a/net/l2tp/Kconfig +++ b/net/l2tp/Kconfig @@ -31,6 +31,19 @@ menuconfig L2TP If you don't need L2TP, say N. To compile all L2TP code as modules, choose M here. +config L2TP_DEBUGFS + tristate "L2TP debugfs support" + depends on L2TP && DEBUG_FS + help + Support for l2tp directory in debugfs filesystem. This may be + used to dump internal state of the l2tp drivers for problem + analysis. + + If unsure, say 'Y'. + + To compile this driver as a module, choose M here. The module + will be called l2tp_debugfs. + config L2TP_V3 bool "L2TPv3 support (EXPERIMENTAL)" depends on EXPERIMENTAL && L2TP diff --git a/net/l2tp/Makefile b/net/l2tp/Makefile index bddbf04f0ed3..110e7bc2de5e 100644 --- a/net/l2tp/Makefile +++ b/net/l2tp/Makefile @@ -9,3 +9,4 @@ obj-$(subst y,$(CONFIG_L2TP),$(CONFIG_PPPOL2TP)) += l2tp_ppp.o obj-$(subst y,$(CONFIG_L2TP),$(CONFIG_L2TP_IP)) += l2tp_ip.o obj-$(subst y,$(CONFIG_L2TP),$(CONFIG_L2TP_V3)) += l2tp_netlink.o obj-$(subst y,$(CONFIG_L2TP),$(CONFIG_L2TP_ETH)) += l2tp_eth.o +obj-$(subst y,$(CONFIG_L2TP),$(CONFIG_L2TP_DEBUGFS)) += l2tp_debugfs.o diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h index 2974d9ade167..571335530c6f 100644 --- a/net/l2tp/l2tp_core.h +++ b/net/l2tp/l2tp_core.h @@ -133,7 +133,9 @@ struct l2tp_session { void (*session_close)(struct l2tp_session *session); void (*ref)(struct l2tp_session *session); void (*deref)(struct l2tp_session *session); - +#ifdef CONFIG_L2TP_DEBUGFS + void (*show)(struct seq_file *m, void *priv); +#endif uint8_t priv[0]; /* private data */ }; @@ -166,7 +168,9 @@ struct l2tp_tunnel { struct net *l2tp_net; /* the net we belong to */ atomic_t ref_count; - +#ifdef CONFIG_DEBUG_FS + void (*show)(struct seq_file *m, void *arg); +#endif int (*recv_payload_hook)(struct sk_buff *skb); void (*old_sk_destruct)(struct sock *); struct sock *sock; /* Parent socket */ diff --git a/net/l2tp/l2tp_debugfs.c b/net/l2tp/l2tp_debugfs.c new file mode 100644 index 000000000000..908f10f9720e --- /dev/null +++ b/net/l2tp/l2tp_debugfs.c @@ -0,0 +1,341 @@ +/* + * L2TP subsystem debugfs + * + * Copyright (c) 2010 Katalix Systems Ltd + * + * 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. + */ + +#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; +static struct dentry *tunnels; + +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) +{ + pd->tunnel = l2tp_tunnel_find_nth(pd->net, pd->tunnel_idx); + pd->tunnel_idx++; +} + +static void l2tp_dfs_next_session(struct l2tp_dfs_seq_data *pd) +{ + pd->session = l2tp_session_find_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) +{ + /* nothing to do */ +} + +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); + seq_printf(m, " from " NIPQUAD_FMT " to " NIPQUAD_FMT "\n", + NIPQUAD(inet->inet_saddr), NIPQUAD(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 ? atomic_read(&tunnel->sock->sk_refcnt) : 0, + atomic_read(&tunnel->ref_count)); + + seq_printf(m, " %08x rx %llu/%llu/%llu rx %llu/%llu/%llu\n", + tunnel->debug, + (unsigned long long)tunnel->stats.tx_packets, + (unsigned long long)tunnel->stats.tx_bytes, + (unsigned long long)tunnel->stats.tx_errors, + (unsigned long long)tunnel->stats.rx_packets, + (unsigned long long)tunnel->stats.rx_bytes, + (unsigned long long)tunnel->stats.rx_errors); + + if (tunnel->show != NULL) + tunnel->show(m, tunnel); +} + +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", atomic_read(&session->ref_count)); + seq_printf(m, " config %d/%d/%c/%c/%s/%s %08x %u\n", + session->mtu, session->mru, + session->recv_seq ? 'R' : '-', + session->send_seq ? 'S' : '-', + session->data_seq == 1 ? "IPSEQ" : + session->data_seq == 2 ? "DATASEQ" : "-", + session->lns_mode ? "LNS" : "LAC", + session->debug, + jiffies_to_msecs(session->reorder_timeout)); + seq_printf(m, " offset %hu l2specific %hu/%hu\n", + session->offset, session->l2specific_type, session->l2specific_len); + 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 %llu/%llu/%llu rx %llu/%llu/%llu\n", + session->nr, session->ns, + (unsigned long long)session->stats.tx_packets, + (unsigned long long)session->stats.tx_bytes, + (unsigned long long)session->stats.tx_errors, + (unsigned long long)session->stats.rx_packets, + (unsigned long long)session->stats.rx_bytes, + (unsigned long long)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; + } + + /* Show the tunnel or session context */ + if (pd->session == NULL) + 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(GFP_KERNEL, sizeof(*pd)); + 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) +{ + int rc = 0; + + rootdir = debugfs_create_dir("l2tp", NULL); + if (IS_ERR(rootdir)) { + rc = PTR_ERR(rootdir); + rootdir = NULL; + goto out; + } + + tunnels = debugfs_create_file("tunnels", 0600, rootdir, NULL, &l2tp_dfs_fops); + if (tunnels == NULL) + rc = -EIO; + + printk(KERN_INFO "L2TP debugfs support\n"); + +out: + if (rc) + printk(KERN_WARNING "l2tp debugfs: unable to init\n"); + + return rc; +} + +static void __exit l2tp_debugfs_exit(void) +{ + debugfs_remove(tunnels); + debugfs_remove(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"); diff --git a/net/l2tp/l2tp_eth.c b/net/l2tp/l2tp_eth.c index 755c29729b6f..9848faa3d163 100644 --- a/net/l2tp/l2tp_eth.c +++ b/net/l2tp/l2tp_eth.c @@ -172,6 +172,17 @@ static void l2tp_eth_delete(struct l2tp_session *session) } } +#ifdef CONFIG_L2TP_DEBUGFS +static void l2tp_eth_show(struct seq_file *m, void *arg) +{ + struct l2tp_session *session = arg; + struct l2tp_eth_sess *spriv = l2tp_session_priv(session); + struct net_device *dev = spriv->dev; + + seq_printf(m, " interface %s\n", dev->name); +} +#endif + static int l2tp_eth_create(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg) { struct net_device *dev; @@ -233,6 +244,9 @@ static int l2tp_eth_create(struct net *net, u32 tunnel_id, u32 session_id, u32 p priv->tunnel_sock = tunnel->sock; session->recv_skb = l2tp_eth_dev_recv; session->session_close = l2tp_eth_delete; +#ifdef CONFIG_L2TP_DEBUGFS + session->show = l2tp_eth_show; +#endif spriv = l2tp_session_priv(session); spriv->dev = dev; diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c index d64f081f2b1c..1ef10e4118d2 100644 --- a/net/l2tp/l2tp_ppp.c +++ b/net/l2tp/l2tp_ppp.c @@ -597,6 +597,20 @@ out: return error; } +#ifdef CONFIG_L2TP_DEBUGFS +static void pppol2tp_show(struct seq_file *m, void *arg) +{ + struct l2tp_session *session = arg; + struct pppol2tp_session *ps = l2tp_session_priv(session); + + if (ps) { + struct pppox_sock *po = pppox_sk(ps->sock); + if (po) + seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan)); + } +} +#endif + /* connect() handler. Attach a PPPoX socket to a tunnel UDP socket */ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr, @@ -734,6 +748,9 @@ static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr, session->recv_skb = pppol2tp_recv; session->session_close = pppol2tp_session_close; +#ifdef CONFIG_L2TP_DEBUGFS + session->show = pppol2tp_show; +#endif /* We need to know each time a skb is dropped from the reorder * queue. -- 2.39.5