net/l2tp/l2tp_debugfs.c

   1 /*
   2  * L2TP subsystem debugfs
   3  *
   4  * Copyright (c) 2010 Katalix Systems Ltd
   5  *
   6  *      This program is free software; you can redistribute it and/or
   7  *      modify it under the terms of the GNU General Public License
   8  *      as published by the Free Software Foundation; either version
   9  *      2 of the License, or (at your option) any later version.
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/skbuff.h>
  14 #include <linux/socket.h>
  15 #include <linux/hash.h>
  16 #include <linux/l2tp.h>
  17 #include <linux/in.h>
  18 #include <linux/etherdevice.h>
  19 #include <linux/spinlock.h>
  20 #include <linux/debugfs.h>
  21 #include <net/sock.h>
  22 #include <net/ip.h>
  23 #include <net/icmp.h>
  24 #include <net/udp.h>
  25 #include <net/inet_common.h>
  26 #include <net/inet_hashtables.h>
  27 #include <net/tcp_states.h>
  28 #include <net/protocol.h>
  29 #include <net/xfrm.h>
  30 #include <net/net_namespace.h>
  31 #include <net/netns/generic.h>
  32
  33 #include "l2tp_core.h"
  34
  35 static struct dentry *rootdir;
  36 static struct dentry *tunnels;
  37
  38 struct l2tp_dfs_seq_data {
  39         struct net *net;
  40         int tunnel_idx;                 /* current tunnel */
  41         int session_idx;                /* index of session within current tunnel */
  42         struct l2tp_tunnel *tunnel;
  43         struct l2tp_session *session;   /* NULL means get next tunnel */
  44 };
  45
  46 static void l2tp_dfs_next_tunnel(struct l2tp_dfs_seq_data *pd)
  47 {
  48         pd->tunnel = l2tp_tunnel_find_nth(pd->net, pd->tunnel_idx);
  49         pd->tunnel_idx++;
  50 }
  51
  52 static void l2tp_dfs_next_session(struct l2tp_dfs_seq_data *pd)
  53 {
  54         pd->session = l2tp_session_find_nth(pd->tunnel, pd->session_idx);
  55         pd->session_idx++;
  56
  57         if (pd->session == NULL) {
  58                 pd->session_idx = 0;
  59                 l2tp_dfs_next_tunnel(pd);
  60         }
  61
  62 }
  63
  64 static void *l2tp_dfs_seq_start(struct seq_file *m, loff_t *offs)
  65 {
  66         struct l2tp_dfs_seq_data *pd = SEQ_START_TOKEN;
  67         loff_t pos = *offs;
  68
  69         if (!pos)
  70                 goto out;
  71
  72         BUG_ON(m->private == NULL);
  73         pd = m->private;
  74
  75         if (pd->tunnel == NULL)
  76                 l2tp_dfs_next_tunnel(pd);
  77         else
  78                 l2tp_dfs_next_session(pd);
  79
  80         /* NULL tunnel and session indicates end of list */
  81         if ((pd->tunnel == NULL) && (pd->session == NULL))
  82                 pd = NULL;
  83
  84 out:
  85         return pd;
  86 }
  87
  88
  89 static void *l2tp_dfs_seq_next(struct seq_file *m, void *v, loff_t *pos)
  90 {
  91         (*pos)++;
  92         return NULL;
  93 }
  94
  95 static void l2tp_dfs_seq_stop(struct seq_file *p, void *v)
  96 {
  97         /* nothing to do */
  98 }
  99
 100 static void l2tp_dfs_seq_tunnel_show(struct seq_file *m, void *v)
 101 {
 102         struct l2tp_tunnel *tunnel = v;
 103         int session_count = 0;
 104         int hash;
 105         struct hlist_node *walk;
 106         struct hlist_node *tmp;
 107
 108         read_lock_bh(&tunnel->hlist_lock);
 109         for (hash = 0; hash < L2TP_HASH_SIZE; hash++) {
 110                 hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) {
 111                         struct l2tp_session *session;
 112
 113                         session = hlist_entry(walk, struct l2tp_session, hlist);
 114                         if (session->session_id == 0)
 115                                 continue;
 116
 117                         session_count++;
 118                 }
 119         }
 120         read_unlock_bh(&tunnel->hlist_lock);
 121
 122         seq_printf(m, "\nTUNNEL %u peer %u", tunnel->tunnel_id, tunnel->peer_tunnel_id);
 123         if (tunnel->sock) {
 124                 struct inet_sock *inet = inet_sk(tunnel->sock);
 125                 seq_printf(m, " from %pI4 to %pI4\n",
 126                            &inet->inet_saddr, &inet->inet_daddr);
 127                 if (tunnel->encap == L2TP_ENCAPTYPE_UDP)
 128                         seq_printf(m, " source port %hu, dest port %hu\n",
 129                                    ntohs(inet->inet_sport), ntohs(inet->inet_dport));
 130         }
 131         seq_printf(m, " L2TPv%d, %s\n", tunnel->version,
 132                    tunnel->encap == L2TP_ENCAPTYPE_UDP ? "UDP" :
 133                    tunnel->encap == L2TP_ENCAPTYPE_IP ? "IP" :
 134                    "");
 135         seq_printf(m, " %d sessions, refcnt %d/%d\n", session_count,
 136                    tunnel->sock ? atomic_read(&tunnel->sock->sk_refcnt) : 0,
 137                    atomic_read(&tunnel->ref_count));
 138
 139         seq_printf(m, " %08x rx %llu/%llu/%llu rx %llu/%llu/%llu\n",
 140                    tunnel->debug,
 141                    (unsigned long long)tunnel->stats.tx_packets,
 142                    (unsigned long long)tunnel->stats.tx_bytes,
 143                    (unsigned long long)tunnel->stats.tx_errors,
 144                    (unsigned long long)tunnel->stats.rx_packets,
 145                    (unsigned long long)tunnel->stats.rx_bytes,
 146                    (unsigned long long)tunnel->stats.rx_errors);
 147
 148         if (tunnel->show != NULL)
 149                 tunnel->show(m, tunnel);
 150 }
 151
 152 static void l2tp_dfs_seq_session_show(struct seq_file *m, void *v)
 153 {
 154         struct l2tp_session *session = v;
 155
 156         seq_printf(m, "  SESSION %u, peer %u, %s\n", session->session_id,
 157                    session->peer_session_id,
 158                    session->pwtype == L2TP_PWTYPE_ETH ? "ETH" :
 159                    session->pwtype == L2TP_PWTYPE_PPP ? "PPP" :
 160                    "");
 161         if (session->send_seq || session->recv_seq)
 162                 seq_printf(m, "   nr %hu, ns %hu\n", session->nr, session->ns);
 163         seq_printf(m, "   refcnt %d\n", atomic_read(&session->ref_count));
 164         seq_printf(m, "   config %d/%d/%c/%c/%s/%s %08x %u\n",
 165                    session->mtu, session->mru,
 166                    session->recv_seq ? 'R' : '-',
 167                    session->send_seq ? 'S' : '-',
 168                    session->data_seq == 1 ? "IPSEQ" :
 169                    session->data_seq == 2 ? "DATASEQ" : "-",
 170                    session->lns_mode ? "LNS" : "LAC",
 171                    session->debug,
 172                    jiffies_to_msecs(session->reorder_timeout));
 173         seq_printf(m, "   offset %hu l2specific %hu/%hu\n",
 174                    session->offset, session->l2specific_type, session->l2specific_len);
 175         if (session->cookie_len) {
 176                 seq_printf(m, "   cookie %02x%02x%02x%02x",
 177                            session->cookie[0], session->cookie[1],
 178                            session->cookie[2], session->cookie[3]);
 179                 if (session->cookie_len == 8)
 180                         seq_printf(m, "%02x%02x%02x%02x",
 181                                    session->cookie[4], session->cookie[5],
 182                                    session->cookie[6], session->cookie[7]);
 183                 seq_printf(m, "\n");
 184         }
 185         if (session->peer_cookie_len) {
 186                 seq_printf(m, "   peer cookie %02x%02x%02x%02x",
 187                            session->peer_cookie[0], session->peer_cookie[1],
 188                            session->peer_cookie[2], session->peer_cookie[3]);
 189                 if (session->peer_cookie_len == 8)
 190                         seq_printf(m, "%02x%02x%02x%02x",
 191                                    session->peer_cookie[4], session->peer_cookie[5],
 192                                    session->peer_cookie[6], session->peer_cookie[7]);
 193                 seq_printf(m, "\n");
 194         }
 195
 196         seq_printf(m, "   %hu/%hu tx %llu/%llu/%llu rx %llu/%llu/%llu\n",
 197                    session->nr, session->ns,
 198                    (unsigned long long)session->stats.tx_packets,
 199                    (unsigned long long)session->stats.tx_bytes,
 200                    (unsigned long long)session->stats.tx_errors,
 201                    (unsigned long long)session->stats.rx_packets,
 202                    (unsigned long long)session->stats.rx_bytes,
 203                    (unsigned long long)session->stats.rx_errors);
 204
 205         if (session->show != NULL)
 206                 session->show(m, session);
 207 }
 208
 209 static int l2tp_dfs_seq_show(struct seq_file *m, void *v)
 210 {
 211         struct l2tp_dfs_seq_data *pd = v;
 212
 213         /* display header on line 1 */
 214         if (v == SEQ_START_TOKEN) {
 215                 seq_puts(m, "TUNNEL ID, peer ID from IP to IP\n");
 216                 seq_puts(m, " L2TPv2/L2TPv3, UDP/IP\n");
 217                 seq_puts(m, " sessions session-count, refcnt refcnt/sk->refcnt\n");
 218                 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
 219                 seq_puts(m, "  SESSION ID, peer ID, PWTYPE\n");
 220                 seq_puts(m, "   refcnt cnt\n");
 221                 seq_puts(m, "   offset OFFSET l2specific TYPE/LEN\n");
 222                 seq_puts(m, "   [ cookie ]\n");
 223                 seq_puts(m, "   [ peer cookie ]\n");
 224                 seq_puts(m, "   config mtu/mru/rcvseq/sendseq/dataseq/lns debug reorderto\n");
 225                 seq_puts(m, "   nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
 226                 goto out;
 227         }
 228
 229         /* Show the tunnel or session context */
 230         if (pd->session == NULL)
 231                 l2tp_dfs_seq_tunnel_show(m, pd->tunnel);
 232         else
 233                 l2tp_dfs_seq_session_show(m, pd->session);
 234
 235 out:
 236         return 0;
 237 }
 238
 239 static const struct seq_operations l2tp_dfs_seq_ops = {
 240         .start          = l2tp_dfs_seq_start,
 241         .next           = l2tp_dfs_seq_next,
 242         .stop           = l2tp_dfs_seq_stop,
 243         .show           = l2tp_dfs_seq_show,
 244 };
 245
 246 static int l2tp_dfs_seq_open(struct inode *inode, struct file *file)
 247 {
 248         struct l2tp_dfs_seq_data *pd;
 249         struct seq_file *seq;
 250         int rc = -ENOMEM;
 251
 252         pd = kzalloc(sizeof(*pd), GFP_KERNEL);
 253         if (pd == NULL)
 254                 goto out;
 255
 256         /* Derive the network namespace from the pid opening the
 257          * file.
 258          */
 259         pd->net = get_net_ns_by_pid(current->pid);
 260         if (IS_ERR(pd->net)) {
 261                 rc = -PTR_ERR(pd->net);
 262                 goto err_free_pd;
 263         }
 264
 265         rc = seq_open(file, &l2tp_dfs_seq_ops);
 266         if (rc)
 267                 goto err_free_net;
 268
 269         seq = file->private_data;
 270         seq->private = pd;
 271
 272 out:
 273         return rc;
 274
 275 err_free_net:
 276         put_net(pd->net);
 277 err_free_pd:
 278         kfree(pd);
 279         goto out;
 280 }
 281
 282 static int l2tp_dfs_seq_release(struct inode *inode, struct file *file)
 283 {
 284         struct l2tp_dfs_seq_data *pd;
 285         struct seq_file *seq;
 286
 287         seq = file->private_data;
 288         pd = seq->private;
 289         if (pd->net)
 290                 put_net(pd->net);
 291         kfree(pd);
 292         seq_release(inode, file);
 293
 294         return 0;
 295 }
 296
 297 static const struct file_operations l2tp_dfs_fops = {
 298         .owner          = THIS_MODULE,
 299         .open           = l2tp_dfs_seq_open,
 300         .read           = seq_read,
 301         .llseek         = seq_lseek,
 302         .release        = l2tp_dfs_seq_release,
 303 };
 304
 305 static int __init l2tp_debugfs_init(void)
 306 {
 307         int rc = 0;
 308
 309         rootdir = debugfs_create_dir("l2tp", NULL);
 310         if (IS_ERR(rootdir)) {
 311                 rc = PTR_ERR(rootdir);
 312                 rootdir = NULL;
 313                 goto out;
 314         }
 315
 316         tunnels = debugfs_create_file("tunnels", 0600, rootdir, NULL, &l2tp_dfs_fops);
 317         if (tunnels == NULL)
 318                 rc = -EIO;
 319
 320         printk(KERN_INFO "L2TP debugfs support\n");
 321
 322 out:
 323         if (rc)
 324                 printk(KERN_WARNING "l2tp debugfs: unable to init\n");
 325
 326         return rc;
 327 }
 328
 329 static void __exit l2tp_debugfs_exit(void)
 330 {
 331         debugfs_remove(tunnels);
 332         debugfs_remove(rootdir);
 333 }
 334
 335 module_init(l2tp_debugfs_init);
 336 module_exit(l2tp_debugfs_exit);
 337
 338 MODULE_LICENSE("GPL");
 339 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
 340 MODULE_DESCRIPTION("L2TP debugfs driver");
 341 MODULE_VERSION("1.0");