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 pd->session = l2tp_session_get_nth(pd->tunnel, pd->session_idx); 61 pd->session_idx++; 62 63 if (pd->session == NULL) { 64 pd->session_idx = 0; 65 l2tp_dfs_next_tunnel(pd); 66 } 67 68 } 69 70 static void *l2tp_dfs_seq_start(struct seq_file *m, loff_t *offs) 71 { 72 struct l2tp_dfs_seq_data *pd = SEQ_START_TOKEN; 73 loff_t pos = *offs; 74 75 if (!pos) 76 goto out; 77 78 BUG_ON(m->private == NULL); 79 pd = m->private; 80 81 if (pd->tunnel == NULL) 82 l2tp_dfs_next_tunnel(pd); 83 else 84 l2tp_dfs_next_session(pd); 85 86 /* NULL tunnel and session indicates end of list */ 87 if ((pd->tunnel == NULL) && (pd->session == NULL)) 88 pd = NULL; 89 90 out: 91 return pd; 92 } 93 94 95 static void *l2tp_dfs_seq_next(struct seq_file *m, void *v, loff_t *pos) 96 { 97 (*pos)++; 98 return NULL; 99 } 100 101 static void l2tp_dfs_seq_stop(struct seq_file *p, void *v) 102 { 103 struct l2tp_dfs_seq_data *pd = v; 104 105 if (!pd || pd == SEQ_START_TOKEN) 106 return; 107 108 /* Drop reference taken by last invocation of l2tp_dfs_next_tunnel() */ 109 if (pd->tunnel) { 110 l2tp_tunnel_dec_refcount(pd->tunnel); 111 pd->tunnel = NULL; 112 pd->session = NULL; 113 } 114 } 115 116 static void l2tp_dfs_seq_tunnel_show(struct seq_file *m, void *v) 117 { 118 struct l2tp_tunnel *tunnel = v; 119 int session_count = 0; 120 int hash; 121 struct hlist_node *walk; 122 struct hlist_node *tmp; 123 124 read_lock_bh(&tunnel->hlist_lock); 125 for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { 126 hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) { 127 struct l2tp_session *session; 128 129 session = hlist_entry(walk, struct l2tp_session, hlist); 130 if (session->session_id == 0) 131 continue; 132 133 session_count++; 134 } 135 } 136 read_unlock_bh(&tunnel->hlist_lock); 137 138 seq_printf(m, "\nTUNNEL %u peer %u", tunnel->tunnel_id, tunnel->peer_tunnel_id); 139 if (tunnel->sock) { 140 struct inet_sock *inet = inet_sk(tunnel->sock); 141 142 #if IS_ENABLED(CONFIG_IPV6) 143 if (tunnel->sock->sk_family == AF_INET6) { 144 const struct ipv6_pinfo *np = inet6_sk(tunnel->sock); 145 146 seq_printf(m, " from %pI6c to %pI6c\n", 147 &np->saddr, &tunnel->sock->sk_v6_daddr); 148 } else 149 #endif 150 seq_printf(m, " from %pI4 to %pI4\n", 151 &inet->inet_saddr, &inet->inet_daddr); 152 if (tunnel->encap == L2TP_ENCAPTYPE_UDP) 153 seq_printf(m, " source port %hu, dest port %hu\n", 154 ntohs(inet->inet_sport), ntohs(inet->inet_dport)); 155 } 156 seq_printf(m, " L2TPv%d, %s\n", tunnel->version, 157 tunnel->encap == L2TP_ENCAPTYPE_UDP ? "UDP" : 158 tunnel->encap == L2TP_ENCAPTYPE_IP ? "IP" : 159 ""); 160 seq_printf(m, " %d sessions, refcnt %d/%d\n", session_count, 161 tunnel->sock ? refcount_read(&tunnel->sock->sk_refcnt) : 0, 162 refcount_read(&tunnel->ref_count)); 163 seq_printf(m, " %08x rx %ld/%ld/%ld rx %ld/%ld/%ld\n", 164 tunnel->debug, 165 atomic_long_read(&tunnel->stats.tx_packets), 166 atomic_long_read(&tunnel->stats.tx_bytes), 167 atomic_long_read(&tunnel->stats.tx_errors), 168 atomic_long_read(&tunnel->stats.rx_packets), 169 atomic_long_read(&tunnel->stats.rx_bytes), 170 atomic_long_read(&tunnel->stats.rx_errors)); 171 172 if (tunnel->show != NULL) 173 tunnel->show(m, tunnel); 174 } 175 176 static void l2tp_dfs_seq_session_show(struct seq_file *m, void *v) 177 { 178 struct l2tp_session *session = v; 179 180 seq_printf(m, " SESSION %u, peer %u, %s\n", session->session_id, 181 session->peer_session_id, 182 session->pwtype == L2TP_PWTYPE_ETH ? "ETH" : 183 session->pwtype == L2TP_PWTYPE_PPP ? "PPP" : 184 ""); 185 if (session->send_seq || session->recv_seq) 186 seq_printf(m, " nr %hu, ns %hu\n", session->nr, session->ns); 187 seq_printf(m, " refcnt %d\n", refcount_read(&session->ref_count)); 188 seq_printf(m, " config %d/%d/%c/%c/%s/%s %08x %u\n", 189 session->mtu, session->mru, 190 session->recv_seq ? 'R' : '-', 191 session->send_seq ? 'S' : '-', 192 session->data_seq == 1 ? "IPSEQ" : 193 session->data_seq == 2 ? "DATASEQ" : "-", 194 session->lns_mode ? "LNS" : "LAC", 195 session->debug, 196 jiffies_to_msecs(session->reorder_timeout)); 197 seq_printf(m, " offset 0 l2specific %hu/%hu\n", 198 session->l2specific_type, l2tp_get_l2specific_len(session)); 199 if (session->cookie_len) { 200 seq_printf(m, " cookie %02x%02x%02x%02x", 201 session->cookie[0], session->cookie[1], 202 session->cookie[2], session->cookie[3]); 203 if (session->cookie_len == 8) 204 seq_printf(m, "%02x%02x%02x%02x", 205 session->cookie[4], session->cookie[5], 206 session->cookie[6], session->cookie[7]); 207 seq_printf(m, "\n"); 208 } 209 if (session->peer_cookie_len) { 210 seq_printf(m, " peer cookie %02x%02x%02x%02x", 211 session->peer_cookie[0], session->peer_cookie[1], 212 session->peer_cookie[2], session->peer_cookie[3]); 213 if (session->peer_cookie_len == 8) 214 seq_printf(m, "%02x%02x%02x%02x", 215 session->peer_cookie[4], session->peer_cookie[5], 216 session->peer_cookie[6], session->peer_cookie[7]); 217 seq_printf(m, "\n"); 218 } 219 220 seq_printf(m, " %hu/%hu tx %ld/%ld/%ld rx %ld/%ld/%ld\n", 221 session->nr, session->ns, 222 atomic_long_read(&session->stats.tx_packets), 223 atomic_long_read(&session->stats.tx_bytes), 224 atomic_long_read(&session->stats.tx_errors), 225 atomic_long_read(&session->stats.rx_packets), 226 atomic_long_read(&session->stats.rx_bytes), 227 atomic_long_read(&session->stats.rx_errors)); 228 229 if (session->show != NULL) 230 session->show(m, session); 231 } 232 233 static int l2tp_dfs_seq_show(struct seq_file *m, void *v) 234 { 235 struct l2tp_dfs_seq_data *pd = v; 236 237 /* display header on line 1 */ 238 if (v == SEQ_START_TOKEN) { 239 seq_puts(m, "TUNNEL ID, peer ID from IP to IP\n"); 240 seq_puts(m, " L2TPv2/L2TPv3, UDP/IP\n"); 241 seq_puts(m, " sessions session-count, refcnt refcnt/sk->refcnt\n"); 242 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); 243 seq_puts(m, " SESSION ID, peer ID, PWTYPE\n"); 244 seq_puts(m, " refcnt cnt\n"); 245 seq_puts(m, " offset OFFSET l2specific TYPE/LEN\n"); 246 seq_puts(m, " [ cookie ]\n"); 247 seq_puts(m, " [ peer cookie ]\n"); 248 seq_puts(m, " config mtu/mru/rcvseq/sendseq/dataseq/lns debug reorderto\n"); 249 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); 250 goto out; 251 } 252 253 /* Show the tunnel or session context */ 254 if (!pd->session) { 255 l2tp_dfs_seq_tunnel_show(m, pd->tunnel); 256 } else { 257 l2tp_dfs_seq_session_show(m, pd->session); 258 l2tp_session_dec_refcount(pd->session); 259 } 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