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