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); 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 0 l2specific %hu/%hu\n", 184 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 l2tp_session_dec_refcount(pd->session); 245 } 246 247 out: 248 return 0; 249 } 250 251 static const struct seq_operations l2tp_dfs_seq_ops = { 252 .start = l2tp_dfs_seq_start, 253 .next = l2tp_dfs_seq_next, 254 .stop = l2tp_dfs_seq_stop, 255 .show = l2tp_dfs_seq_show, 256 }; 257 258 static int l2tp_dfs_seq_open(struct inode *inode, struct file *file) 259 { 260 struct l2tp_dfs_seq_data *pd; 261 struct seq_file *seq; 262 int rc = -ENOMEM; 263 264 pd = kzalloc(sizeof(*pd), GFP_KERNEL); 265 if (pd == NULL) 266 goto out; 267 268 /* Derive the network namespace from the pid opening the 269 * file. 270 */ 271 pd->net = get_net_ns_by_pid(current->pid); 272 if (IS_ERR(pd->net)) { 273 rc = PTR_ERR(pd->net); 274 goto err_free_pd; 275 } 276 277 rc = seq_open(file, &l2tp_dfs_seq_ops); 278 if (rc) 279 goto err_free_net; 280 281 seq = file->private_data; 282 seq->private = pd; 283 284 out: 285 return rc; 286 287 err_free_net: 288 put_net(pd->net); 289 err_free_pd: 290 kfree(pd); 291 goto out; 292 } 293 294 static int l2tp_dfs_seq_release(struct inode *inode, struct file *file) 295 { 296 struct l2tp_dfs_seq_data *pd; 297 struct seq_file *seq; 298 299 seq = file->private_data; 300 pd = seq->private; 301 if (pd->net) 302 put_net(pd->net); 303 kfree(pd); 304 seq_release(inode, file); 305 306 return 0; 307 } 308 309 static const struct file_operations l2tp_dfs_fops = { 310 .owner = THIS_MODULE, 311 .open = l2tp_dfs_seq_open, 312 .read = seq_read, 313 .llseek = seq_lseek, 314 .release = l2tp_dfs_seq_release, 315 }; 316 317 static int __init l2tp_debugfs_init(void) 318 { 319 int rc = 0; 320 321 rootdir = debugfs_create_dir("l2tp", NULL); 322 if (IS_ERR(rootdir)) { 323 rc = PTR_ERR(rootdir); 324 rootdir = NULL; 325 goto out; 326 } 327 328 tunnels = debugfs_create_file("tunnels", 0600, rootdir, NULL, &l2tp_dfs_fops); 329 if (tunnels == NULL) 330 rc = -EIO; 331 332 pr_info("L2TP debugfs support\n"); 333 334 out: 335 if (rc) 336 pr_warn("unable to init\n"); 337 338 return rc; 339 } 340 341 static void __exit l2tp_debugfs_exit(void) 342 { 343 debugfs_remove(tunnels); 344 debugfs_remove(rootdir); 345 } 346 347 module_init(l2tp_debugfs_init); 348 module_exit(l2tp_debugfs_exit); 349 350 MODULE_LICENSE("GPL"); 351 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); 352 MODULE_DESCRIPTION("L2TP debugfs driver"); 353 MODULE_VERSION("1.0"); 354