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 /* Drop reference taken during previous invocation */ 51 if (pd->tunnel) 52 l2tp_tunnel_dec_refcount(pd->tunnel); 53 54 pd->tunnel = l2tp_tunnel_get_nth(pd->net, pd->tunnel_idx); 55 pd->tunnel_idx++; 56 } 57 58 static void l2tp_dfs_next_session(struct l2tp_dfs_seq_data *pd) 59 { 60 /* Drop reference taken during previous invocation */ 61 if (pd->session) 62 l2tp_session_dec_refcount(pd->session); 63 64 pd->session = l2tp_session_get_nth(pd->tunnel, pd->session_idx); 65 pd->session_idx++; 66 67 if (pd->session == NULL) { 68 pd->session_idx = 0; 69 l2tp_dfs_next_tunnel(pd); 70 } 71 72 } 73 74 static void *l2tp_dfs_seq_start(struct seq_file *m, loff_t *offs) 75 { 76 struct l2tp_dfs_seq_data *pd = SEQ_START_TOKEN; 77 loff_t pos = *offs; 78 79 if (!pos) 80 goto out; 81 82 BUG_ON(m->private == NULL); 83 pd = m->private; 84 85 if (pd->tunnel == NULL) 86 l2tp_dfs_next_tunnel(pd); 87 else 88 l2tp_dfs_next_session(pd); 89 90 /* NULL tunnel and session indicates end of list */ 91 if ((pd->tunnel == NULL) && (pd->session == NULL)) 92 pd = NULL; 93 94 out: 95 return pd; 96 } 97 98 99 static void *l2tp_dfs_seq_next(struct seq_file *m, void *v, loff_t *pos) 100 { 101 (*pos)++; 102 return NULL; 103 } 104 105 static void l2tp_dfs_seq_stop(struct seq_file *p, void *v) 106 { 107 struct l2tp_dfs_seq_data *pd = v; 108 109 if (!pd || pd == SEQ_START_TOKEN) 110 return; 111 112 /* Drop reference taken by last invocation of l2tp_dfs_next_session() 113 * or l2tp_dfs_next_tunnel(). 114 */ 115 if (pd->session) { 116 l2tp_session_dec_refcount(pd->session); 117 pd->session = NULL; 118 } 119 if (pd->tunnel) { 120 l2tp_tunnel_dec_refcount(pd->tunnel); 121 pd->tunnel = NULL; 122 } 123 } 124 125 static void l2tp_dfs_seq_tunnel_show(struct seq_file *m, void *v) 126 { 127 struct l2tp_tunnel *tunnel = v; 128 int session_count = 0; 129 int hash; 130 struct hlist_node *walk; 131 struct hlist_node *tmp; 132 133 read_lock_bh(&tunnel->hlist_lock); 134 for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { 135 hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) { 136 struct l2tp_session *session; 137 138 session = hlist_entry(walk, struct l2tp_session, hlist); 139 if (session->session_id == 0) 140 continue; 141 142 session_count++; 143 } 144 } 145 read_unlock_bh(&tunnel->hlist_lock); 146 147 seq_printf(m, "\nTUNNEL %u peer %u", tunnel->tunnel_id, tunnel->peer_tunnel_id); 148 if (tunnel->sock) { 149 struct inet_sock *inet = inet_sk(tunnel->sock); 150 151 #if IS_ENABLED(CONFIG_IPV6) 152 if (tunnel->sock->sk_family == AF_INET6) { 153 const struct ipv6_pinfo *np = inet6_sk(tunnel->sock); 154 155 seq_printf(m, " from %pI6c to %pI6c\n", 156 &np->saddr, &tunnel->sock->sk_v6_daddr); 157 } else 158 #endif 159 seq_printf(m, " from %pI4 to %pI4\n", 160 &inet->inet_saddr, &inet->inet_daddr); 161 if (tunnel->encap == L2TP_ENCAPTYPE_UDP) 162 seq_printf(m, " source port %hu, dest port %hu\n", 163 ntohs(inet->inet_sport), ntohs(inet->inet_dport)); 164 } 165 seq_printf(m, " L2TPv%d, %s\n", tunnel->version, 166 tunnel->encap == L2TP_ENCAPTYPE_UDP ? "UDP" : 167 tunnel->encap == L2TP_ENCAPTYPE_IP ? "IP" : 168 ""); 169 seq_printf(m, " %d sessions, refcnt %d/%d\n", session_count, 170 tunnel->sock ? refcount_read(&tunnel->sock->sk_refcnt) : 0, 171 refcount_read(&tunnel->ref_count)); 172 seq_printf(m, " %08x rx %ld/%ld/%ld rx %ld/%ld/%ld\n", 173 tunnel->debug, 174 atomic_long_read(&tunnel->stats.tx_packets), 175 atomic_long_read(&tunnel->stats.tx_bytes), 176 atomic_long_read(&tunnel->stats.tx_errors), 177 atomic_long_read(&tunnel->stats.rx_packets), 178 atomic_long_read(&tunnel->stats.rx_bytes), 179 atomic_long_read(&tunnel->stats.rx_errors)); 180 } 181 182 static void l2tp_dfs_seq_session_show(struct seq_file *m, void *v) 183 { 184 struct l2tp_session *session = v; 185 186 seq_printf(m, " SESSION %u, peer %u, %s\n", session->session_id, 187 session->peer_session_id, 188 session->pwtype == L2TP_PWTYPE_ETH ? "ETH" : 189 session->pwtype == L2TP_PWTYPE_PPP ? "PPP" : 190 ""); 191 if (session->send_seq || session->recv_seq) 192 seq_printf(m, " nr %hu, ns %hu\n", session->nr, session->ns); 193 seq_printf(m, " refcnt %d\n", refcount_read(&session->ref_count)); 194 seq_printf(m, " config 0/0/%c/%c/-/%s %08x %u\n", 195 session->recv_seq ? 'R' : '-', 196 session->send_seq ? 'S' : '-', 197 session->lns_mode ? "LNS" : "LAC", 198 session->debug, 199 jiffies_to_msecs(session->reorder_timeout)); 200 seq_printf(m, " offset 0 l2specific %hu/%hu\n", 201 session->l2specific_type, l2tp_get_l2specific_len(session)); 202 if (session->cookie_len) { 203 seq_printf(m, " cookie %02x%02x%02x%02x", 204 session->cookie[0], session->cookie[1], 205 session->cookie[2], session->cookie[3]); 206 if (session->cookie_len == 8) 207 seq_printf(m, "%02x%02x%02x%02x", 208 session->cookie[4], session->cookie[5], 209 session->cookie[6], session->cookie[7]); 210 seq_printf(m, "\n"); 211 } 212 if (session->peer_cookie_len) { 213 seq_printf(m, " peer cookie %02x%02x%02x%02x", 214 session->peer_cookie[0], session->peer_cookie[1], 215 session->peer_cookie[2], session->peer_cookie[3]); 216 if (session->peer_cookie_len == 8) 217 seq_printf(m, "%02x%02x%02x%02x", 218 session->peer_cookie[4], session->peer_cookie[5], 219 session->peer_cookie[6], session->peer_cookie[7]); 220 seq_printf(m, "\n"); 221 } 222 223 seq_printf(m, " %hu/%hu tx %ld/%ld/%ld rx %ld/%ld/%ld\n", 224 session->nr, session->ns, 225 atomic_long_read(&session->stats.tx_packets), 226 atomic_long_read(&session->stats.tx_bytes), 227 atomic_long_read(&session->stats.tx_errors), 228 atomic_long_read(&session->stats.rx_packets), 229 atomic_long_read(&session->stats.rx_bytes), 230 atomic_long_read(&session->stats.rx_errors)); 231 232 if (session->show != NULL) 233 session->show(m, session); 234 } 235 236 static int l2tp_dfs_seq_show(struct seq_file *m, void *v) 237 { 238 struct l2tp_dfs_seq_data *pd = v; 239 240 /* display header on line 1 */ 241 if (v == SEQ_START_TOKEN) { 242 seq_puts(m, "TUNNEL ID, peer ID from IP to IP\n"); 243 seq_puts(m, " L2TPv2/L2TPv3, UDP/IP\n"); 244 seq_puts(m, " sessions session-count, refcnt refcnt/sk->refcnt\n"); 245 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); 246 seq_puts(m, " SESSION ID, peer ID, PWTYPE\n"); 247 seq_puts(m, " refcnt cnt\n"); 248 seq_puts(m, " offset OFFSET l2specific TYPE/LEN\n"); 249 seq_puts(m, " [ cookie ]\n"); 250 seq_puts(m, " [ peer cookie ]\n"); 251 seq_puts(m, " config mtu/mru/rcvseq/sendseq/dataseq/lns debug reorderto\n"); 252 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); 253 goto out; 254 } 255 256 if (!pd->session) 257 l2tp_dfs_seq_tunnel_show(m, pd->tunnel); 258 else 259 l2tp_dfs_seq_session_show(m, pd->session); 260 261 out: 262 return 0; 263 } 264 265 static const struct seq_operations l2tp_dfs_seq_ops = { 266 .start = l2tp_dfs_seq_start, 267 .next = l2tp_dfs_seq_next, 268 .stop = l2tp_dfs_seq_stop, 269 .show = l2tp_dfs_seq_show, 270 }; 271 272 static int l2tp_dfs_seq_open(struct inode *inode, struct file *file) 273 { 274 struct l2tp_dfs_seq_data *pd; 275 struct seq_file *seq; 276 int rc = -ENOMEM; 277 278 pd = kzalloc(sizeof(*pd), GFP_KERNEL); 279 if (pd == NULL) 280 goto out; 281 282 /* Derive the network namespace from the pid opening the 283 * file. 284 */ 285 pd->net = get_net_ns_by_pid(current->pid); 286 if (IS_ERR(pd->net)) { 287 rc = PTR_ERR(pd->net); 288 goto err_free_pd; 289 } 290 291 rc = seq_open(file, &l2tp_dfs_seq_ops); 292 if (rc) 293 goto err_free_net; 294 295 seq = file->private_data; 296 seq->private = pd; 297 298 out: 299 return rc; 300 301 err_free_net: 302 put_net(pd->net); 303 err_free_pd: 304 kfree(pd); 305 goto out; 306 } 307 308 static int l2tp_dfs_seq_release(struct inode *inode, struct file *file) 309 { 310 struct l2tp_dfs_seq_data *pd; 311 struct seq_file *seq; 312 313 seq = file->private_data; 314 pd = seq->private; 315 if (pd->net) 316 put_net(pd->net); 317 kfree(pd); 318 seq_release(inode, file); 319 320 return 0; 321 } 322 323 static const struct file_operations l2tp_dfs_fops = { 324 .owner = THIS_MODULE, 325 .open = l2tp_dfs_seq_open, 326 .read = seq_read, 327 .llseek = seq_lseek, 328 .release = l2tp_dfs_seq_release, 329 }; 330 331 static int __init l2tp_debugfs_init(void) 332 { 333 int rc = 0; 334 335 rootdir = debugfs_create_dir("l2tp", NULL); 336 if (IS_ERR(rootdir)) { 337 rc = PTR_ERR(rootdir); 338 rootdir = NULL; 339 goto out; 340 } 341 342 tunnels = debugfs_create_file("tunnels", 0600, rootdir, NULL, &l2tp_dfs_fops); 343 if (tunnels == NULL) 344 rc = -EIO; 345 346 pr_info("L2TP debugfs support\n"); 347 348 out: 349 if (rc) 350 pr_warn("unable to init\n"); 351 352 return rc; 353 } 354 355 static void __exit l2tp_debugfs_exit(void) 356 { 357 debugfs_remove(tunnels); 358 debugfs_remove(rootdir); 359 } 360 361 module_init(l2tp_debugfs_init); 362 module_exit(l2tp_debugfs_exit); 363 364 MODULE_LICENSE("GPL"); 365 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); 366 MODULE_DESCRIPTION("L2TP debugfs driver"); 367 MODULE_VERSION("1.0"); 368