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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  13
  14 #include <linux/module.h>
  15 #include <linux/skbuff.h>
  16 #include <linux/socket.h>
  17 #include <linux/hash.h>
  18 #include <linux/l2tp.h>
  19 #include <linux/in.h>
  20 #include <linux/etherdevice.h>
  21 #include <linux/spinlock.h>
  22 #include <linux/debugfs.h>
  23 #include <net/sock.h>
  24 #include <net/ip.h>
  25 #include <net/icmp.h>
  26 #include <net/udp.h>
  27 #include <net/inet_common.h>
  28 #include <net/inet_hashtables.h>
  29 #include <net/tcp_states.h>
  30 #include <net/protocol.h>
  31 #include <net/xfrm.h>
  32 #include <net/net_namespace.h>
  33 #include <net/netns/generic.h>
  34
  35 #include "l2tp_core.h"
  36
  37 static struct dentry *rootdir;
  38 static struct dentry *tunnels;
  39
  40 struct l2tp_dfs_seq_data {
  41         struct net *net;
  42         int tunnel_idx;                 /* current tunnel */
  43         int session_idx;                /* index of session within current tunnel */
  44         struct l2tp_tunnel *tunnel;
  45         struct l2tp_session *session;   /* NULL means get next tunnel */
  46 };
  47
  48 static void l2tp_dfs_next_tunnel(struct l2tp_dfs_seq_data *pd)
  49 {
  50         pd->tunnel = l2tp_tunnel_find_nth(pd->net, pd->tunnel_idx);
  51         pd->tunnel_idx++;
  52 }
  53
  54 static void l2tp_dfs_next_session(struct l2tp_dfs_seq_data *pd)
  55 {
  56         pd->session = l2tp_session_get_nth(pd->tunnel, pd->session_idx, true);
  57         pd->session_idx++;
  58
  59         if (pd->session == NULL) {
  60                 pd->session_idx = 0;
  61                 l2tp_dfs_next_tunnel(pd);
  62         }
  63
  64 }
  65
  66 static void *l2tp_dfs_seq_start(struct seq_file *m, loff_t *offs)
  67 {
  68         struct l2tp_dfs_seq_data *pd = SEQ_START_TOKEN;
  69         loff_t pos = *offs;
  70
  71         if (!pos)
  72                 goto out;
  73
  74         BUG_ON(m->private == NULL);
  75         pd = m->private;
  76
  77         if (pd->tunnel == NULL)
  78                 l2tp_dfs_next_tunnel(pd);
  79         else
  80                 l2tp_dfs_next_session(pd);
  81
  82         /* NULL tunnel and session indicates end of list */
  83         if ((pd->tunnel == NULL) && (pd->session == NULL))
  84                 pd = NULL;
  85
  86 out:
  87         return pd;
  88 }
  89
  90
  91 static void *l2tp_dfs_seq_next(struct seq_file *m, void *v, loff_t *pos)
  92 {
  93         (*pos)++;
  94         return NULL;
  95 }
  96
  97 static void l2tp_dfs_seq_stop(struct seq_file *p, void *v)
  98 {
  99         /* nothing to do */
 100 }
 101
 102 static void l2tp_dfs_seq_tunnel_show(struct seq_file *m, void *v)
 103 {
 104         struct l2tp_tunnel *tunnel = v;
 105         int session_count = 0;
 106         int hash;
 107         struct hlist_node *walk;
 108         struct hlist_node *tmp;
 109
 110         read_lock_bh(&tunnel->hlist_lock);
 111         for (hash = 0; hash < L2TP_HASH_SIZE; hash++) {
 112                 hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) {
 113                         struct l2tp_session *session;
 114
 115                         session = hlist_entry(walk, struct l2tp_session, hlist);
 116                         if (session->session_id == 0)
 117                                 continue;
 118
 119                         session_count++;
 120                 }
 121         }
 122         read_unlock_bh(&tunnel->hlist_lock);
 123
 124         seq_printf(m, "\nTUNNEL %u peer %u", tunnel->tunnel_id, tunnel->peer_tunnel_id);
 125         if (tunnel->sock) {
 126                 struct inet_sock *inet = inet_sk(tunnel->sock);
 127
 128 #if IS_ENABLED(CONFIG_IPV6)
 129                 if (tunnel->sock->sk_family == AF_INET6) {
 130                         const struct ipv6_pinfo *np = inet6_sk(tunnel->sock);
 131
 132                         seq_printf(m, " from %pI6c to %pI6c\n",
 133                                 &np->saddr, &tunnel->sock->sk_v6_daddr);
 134                 } else
 135 #endif
 136                 seq_printf(m, " from %pI4 to %pI4\n",
 137                            &inet->inet_saddr, &inet->inet_daddr);
 138                 if (tunnel->encap == L2TP_ENCAPTYPE_UDP)
 139                         seq_printf(m, " source port %hu, dest port %hu\n",
 140                                    ntohs(inet->inet_sport), ntohs(inet->inet_dport));
 141         }
 142         seq_printf(m, " L2TPv%d, %s\n", tunnel->version,
 143                    tunnel->encap == L2TP_ENCAPTYPE_UDP ? "UDP" :
 144                    tunnel->encap == L2TP_ENCAPTYPE_IP ? "IP" :
 145                    "");
 146         seq_printf(m, " %d sessions, refcnt %d/%d\n", session_count,
 147                    tunnel->sock ? refcount_read(&tunnel->sock->sk_refcnt) : 0,
 148                    refcount_read(&tunnel->ref_count));
 149         seq_printf(m, " %08x rx %ld/%ld/%ld rx %ld/%ld/%ld\n",
 150                    tunnel->debug,
 151                    atomic_long_read(&tunnel->stats.tx_packets),
 152                    atomic_long_read(&tunnel->stats.tx_bytes),
 153                    atomic_long_read(&tunnel->stats.tx_errors),
 154                    atomic_long_read(&tunnel->stats.rx_packets),
 155                    atomic_long_read(&tunnel->stats.rx_bytes),
 156                    atomic_long_read(&tunnel->stats.rx_errors));
 157
 158         if (tunnel->show != NULL)
 159                 tunnel->show(m, tunnel);
 160 }
 161
 162 static void l2tp_dfs_seq_session_show(struct seq_file *m, void *v)
 163 {
 164         struct l2tp_session *session = v;
 165
 166         seq_printf(m, "  SESSION %u, peer %u, %s\n", session->session_id,
 167                    session->peer_session_id,
 168                    session->pwtype == L2TP_PWTYPE_ETH ? "ETH" :
 169                    session->pwtype == L2TP_PWTYPE_PPP ? "PPP" :
 170                    "");
 171         if (session->send_seq || session->recv_seq)
 172                 seq_printf(m, "   nr %hu, ns %hu\n", session->nr, session->ns);
 173         seq_printf(m, "   refcnt %d\n", refcount_read(&session->ref_count));
 174         seq_printf(m, "   config %d/%d/%c/%c/%s/%s %08x %u\n",
 175                    session->mtu, session->mru,
 176                    session->recv_seq ? 'R' : '-',
 177                    session->send_seq ? 'S' : '-',
 178                    session->data_seq == 1 ? "IPSEQ" :
 179                    session->data_seq == 2 ? "DATASEQ" : "-",
 180                    session->lns_mode ? "LNS" : "LAC",
 181                    session->debug,
 182                    jiffies_to_msecs(session->reorder_timeout));
 183         seq_printf(m, "   offset %hu l2specific %hu/%hu\n",
 184                    session->offset, session->l2specific_type, session->l2specific_len);
 185         if (session->cookie_len) {
 186                 seq_printf(m, "   cookie %02x%02x%02x%02x",
 187                            session->cookie[0], session->cookie[1],
 188                            session->cookie[2], session->cookie[3]);
 189                 if (session->cookie_len == 8)
 190                         seq_printf(m, "%02x%02x%02x%02x",
 191                                    session->cookie[4], session->cookie[5],
 192                                    session->cookie[6], session->cookie[7]);
 193                 seq_printf(m, "\n");
 194         }
 195         if (session->peer_cookie_len) {
 196                 seq_printf(m, "   peer cookie %02x%02x%02x%02x",
 197                            session->peer_cookie[0], session->peer_cookie[1],
 198                            session->peer_cookie[2], session->peer_cookie[3]);
 199                 if (session->peer_cookie_len == 8)
 200                         seq_printf(m, "%02x%02x%02x%02x",
 201                                    session->peer_cookie[4], session->peer_cookie[5],
 202                                    session->peer_cookie[6], session->peer_cookie[7]);
 203                 seq_printf(m, "\n");
 204         }
 205
 206         seq_printf(m, "   %hu/%hu tx %ld/%ld/%ld rx %ld/%ld/%ld\n",
 207                    session->nr, session->ns,
 208                    atomic_long_read(&session->stats.tx_packets),
 209                    atomic_long_read(&session->stats.tx_bytes),
 210                    atomic_long_read(&session->stats.tx_errors),
 211                    atomic_long_read(&session->stats.rx_packets),
 212                    atomic_long_read(&session->stats.rx_bytes),
 213                    atomic_long_read(&session->stats.rx_errors));
 214
 215         if (session->show != NULL)
 216                 session->show(m, session);
 217 }
 218
 219 static int l2tp_dfs_seq_show(struct seq_file *m, void *v)
 220 {
 221         struct l2tp_dfs_seq_data *pd = v;
 222
 223         /* display header on line 1 */
 224         if (v == SEQ_START_TOKEN) {
 225                 seq_puts(m, "TUNNEL ID, peer ID from IP to IP\n");
 226                 seq_puts(m, " L2TPv2/L2TPv3, UDP/IP\n");
 227                 seq_puts(m, " sessions session-count, refcnt refcnt/sk->refcnt\n");
 228                 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
 229                 seq_puts(m, "  SESSION ID, peer ID, PWTYPE\n");
 230                 seq_puts(m, "   refcnt cnt\n");
 231                 seq_puts(m, "   offset OFFSET l2specific TYPE/LEN\n");
 232                 seq_puts(m, "   [ cookie ]\n");
 233                 seq_puts(m, "   [ peer cookie ]\n");
 234                 seq_puts(m, "   config mtu/mru/rcvseq/sendseq/dataseq/lns debug reorderto\n");
 235                 seq_puts(m, "   nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n");
 236                 goto out;
 237         }
 238
 239         /* Show the tunnel or session context */
 240         if (!pd->session) {
 241                 l2tp_dfs_seq_tunnel_show(m, pd->tunnel);
 242         } else {
 243                 l2tp_dfs_seq_session_show(m, pd->session);
 244                 if (pd->session->deref)
 245                         pd->session->deref(pd->session);
 246                 l2tp_session_dec_refcount(pd->session);
 247         }
 248
 249 out:
 250         return 0;
 251 }
 252
 253 static const struct seq_operations l2tp_dfs_seq_ops = {
 254         .start          = l2tp_dfs_seq_start,
 255         .next           = l2tp_dfs_seq_next,
 256         .stop           = l2tp_dfs_seq_stop,
 257         .show           = l2tp_dfs_seq_show,
 258 };
 259
 260 static int l2tp_dfs_seq_open(struct inode *inode, struct file *file)
 261 {
 262         struct l2tp_dfs_seq_data *pd;
 263         struct seq_file *seq;
 264         int rc = -ENOMEM;
 265
 266         pd = kzalloc(sizeof(*pd), GFP_KERNEL);
 267         if (pd == NULL)
 268                 goto out;
 269
 270         /* Derive the network namespace from the pid opening the
 271          * file.
 272          */
 273         pd->net = get_net_ns_by_pid(current->pid);
 274         if (IS_ERR(pd->net)) {
 275                 rc = PTR_ERR(pd->net);
 276                 goto err_free_pd;
 277         }
 278
 279         rc = seq_open(file, &l2tp_dfs_seq_ops);
 280         if (rc)
 281                 goto err_free_net;
 282
 283         seq = file->private_data;
 284         seq->private = pd;
 285
 286 out:
 287         return rc;
 288
 289 err_free_net:
 290         put_net(pd->net);
 291 err_free_pd:
 292         kfree(pd);
 293         goto out;
 294 }
 295
 296 static int l2tp_dfs_seq_release(struct inode *inode, struct file *file)
 297 {
 298         struct l2tp_dfs_seq_data *pd;
 299         struct seq_file *seq;
 300
 301         seq = file->private_data;
 302         pd = seq->private;
 303         if (pd->net)
 304                 put_net(pd->net);
 305         kfree(pd);
 306         seq_release(inode, file);
 307
 308         return 0;
 309 }
 310
 311 static const struct file_operations l2tp_dfs_fops = {
 312         .owner          = THIS_MODULE,
 313         .open           = l2tp_dfs_seq_open,
 314         .read           = seq_read,
 315         .llseek         = seq_lseek,
 316         .release        = l2tp_dfs_seq_release,
 317 };
 318
 319 static int __init l2tp_debugfs_init(void)
 320 {
 321         int rc = 0;
 322
 323         rootdir = debugfs_create_dir("l2tp", NULL);
 324         if (IS_ERR(rootdir)) {
 325                 rc = PTR_ERR(rootdir);
 326                 rootdir = NULL;
 327                 goto out;
 328         }
 329
 330         tunnels = debugfs_create_file("tunnels", 0600, rootdir, NULL, &l2tp_dfs_fops);
 331         if (tunnels == NULL)
 332                 rc = -EIO;
 333
 334         pr_info("L2TP debugfs support\n");
 335
 336 out:
 337         if (rc)
 338                 pr_warn("unable to init\n");
 339
 340         return rc;
 341 }
 342
 343 static void __exit l2tp_debugfs_exit(void)
 344 {
 345         debugfs_remove(tunnels);
 346         debugfs_remove(rootdir);
 347 }
 348
 349 module_init(l2tp_debugfs_init);
 350 module_exit(l2tp_debugfs_exit);
 351
 352 MODULE_LICENSE("GPL");
 353 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>");
 354 MODULE_DESCRIPTION("L2TP debugfs driver");
 355 MODULE_VERSION("1.0");