1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* L2TP subsystem debugfs 3 * 4 * Copyright (c) 2010 Katalix Systems Ltd 5 */ 6 7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 8 9 #include <linux/module.h> 10 #include <linux/skbuff.h> 11 #include <linux/socket.h> 12 #include <linux/hash.h> 13 #include <linux/l2tp.h> 14 #include <linux/in.h> 15 #include <linux/etherdevice.h> 16 #include <linux/spinlock.h> 17 #include <linux/debugfs.h> 18 #include <net/sock.h> 19 #include <net/ip.h> 20 #include <net/icmp.h> 21 #include <net/udp.h> 22 #include <net/inet_common.h> 23 #include <net/inet_hashtables.h> 24 #include <net/tcp_states.h> 25 #include <net/protocol.h> 26 #include <net/xfrm.h> 27 #include <net/net_namespace.h> 28 #include <net/netns/generic.h> 29 30 #include "l2tp_core.h" 31 32 static struct dentry *rootdir; 33 34 struct l2tp_dfs_seq_data { 35 struct net *net; 36 netns_tracker ns_tracker; 37 unsigned long tkey; /* lookup key of current tunnel */ 38 unsigned long skey; /* lookup key of current session */ 39 struct l2tp_tunnel *tunnel; 40 struct l2tp_session *session; /* NULL means get next tunnel */ 41 }; 42 l2tp_dfs_next_tunnel(struct l2tp_dfs_seq_data * pd)43 static void l2tp_dfs_next_tunnel(struct l2tp_dfs_seq_data *pd) 44 { 45 /* Drop reference taken during previous invocation */ 46 if (pd->tunnel) 47 l2tp_tunnel_put(pd->tunnel); 48 49 pd->tunnel = l2tp_tunnel_get_next(pd->net, &pd->tkey); 50 pd->tkey++; 51 } 52 l2tp_dfs_next_session(struct l2tp_dfs_seq_data * pd)53 static void l2tp_dfs_next_session(struct l2tp_dfs_seq_data *pd) 54 { 55 /* Drop reference taken during previous invocation */ 56 if (pd->session) 57 l2tp_session_put(pd->session); 58 59 pd->session = l2tp_session_get_next(pd->net, pd->tunnel->sock, 60 pd->tunnel->version, 61 pd->tunnel->tunnel_id, &pd->skey); 62 pd->skey++; 63 64 if (!pd->session) { 65 pd->skey = 0; 66 l2tp_dfs_next_tunnel(pd); 67 } 68 } 69 l2tp_dfs_seq_start(struct seq_file * m,loff_t * offs)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 if (WARN_ON(!m->private)) { 79 pd = NULL; 80 goto out; 81 } 82 pd = m->private; 83 84 if (!pd->tunnel) 85 l2tp_dfs_next_tunnel(pd); 86 else 87 l2tp_dfs_next_session(pd); 88 89 /* NULL tunnel and session indicates end of list */ 90 if (!pd->tunnel && !pd->session) 91 pd = NULL; 92 93 out: 94 return pd; 95 } 96 l2tp_dfs_seq_next(struct seq_file * m,void * v,loff_t * pos)97 static void *l2tp_dfs_seq_next(struct seq_file *m, void *v, loff_t *pos) 98 { 99 (*pos)++; 100 return NULL; 101 } 102 l2tp_dfs_seq_stop(struct seq_file * p,void * v)103 static void l2tp_dfs_seq_stop(struct seq_file *p, void *v) 104 { 105 struct l2tp_dfs_seq_data *pd = v; 106 107 if (!pd || pd == SEQ_START_TOKEN) 108 return; 109 110 /* Drop reference taken by last invocation of l2tp_dfs_next_session() 111 * or l2tp_dfs_next_tunnel(). 112 */ 113 if (pd->session) { 114 l2tp_session_put(pd->session); 115 pd->session = NULL; 116 } 117 if (pd->tunnel) { 118 l2tp_tunnel_put(pd->tunnel); 119 pd->tunnel = NULL; 120 } 121 } 122 l2tp_dfs_seq_tunnel_show(struct seq_file * m,void * v)123 static void l2tp_dfs_seq_tunnel_show(struct seq_file *m, void *v) 124 { 125 struct l2tp_tunnel *tunnel = v; 126 struct l2tp_session *session; 127 int session_count = 0; 128 129 rcu_read_lock_bh(); 130 list_for_each_entry_rcu(session, &tunnel->session_list, list) { 131 /* Session ID of zero is a dummy/reserved value used by pppol2tp */ 132 if (session->session_id == 0) 133 continue; 134 135 session_count++; 136 } 137 rcu_read_unlock_bh(); 138 139 seq_printf(m, "\nTUNNEL %u peer %u", tunnel->tunnel_id, tunnel->peer_tunnel_id); 140 if (tunnel->sock) { 141 struct inet_sock *inet = inet_sk(tunnel->sock); 142 143 #if IS_ENABLED(CONFIG_IPV6) 144 if (tunnel->sock->sk_family == AF_INET6) { 145 const struct ipv6_pinfo *np = inet6_sk(tunnel->sock); 146 147 seq_printf(m, " from %pI6c to %pI6c\n", 148 &np->saddr, &tunnel->sock->sk_v6_daddr); 149 } 150 #endif 151 if (tunnel->sock->sk_family == AF_INET) 152 seq_printf(m, " from %pI4 to %pI4\n", 153 &inet->inet_saddr, &inet->inet_daddr); 154 155 if (tunnel->encap == L2TP_ENCAPTYPE_UDP) 156 seq_printf(m, " source port %hu, dest port %hu\n", 157 ntohs(inet->inet_sport), ntohs(inet->inet_dport)); 158 } 159 seq_printf(m, " L2TPv%d, %s\n", tunnel->version, 160 tunnel->encap == L2TP_ENCAPTYPE_UDP ? "UDP" : 161 tunnel->encap == L2TP_ENCAPTYPE_IP ? "IP" : 162 ""); 163 seq_printf(m, " %d sessions, refcnt %d/%d\n", session_count, 164 tunnel->sock ? refcount_read(&tunnel->sock->sk_refcnt) : 0, 165 refcount_read(&tunnel->ref_count)); 166 seq_printf(m, " %08x rx %ld/%ld/%ld rx %ld/%ld/%ld\n", 167 0, 168 atomic_long_read(&tunnel->stats.tx_packets), 169 atomic_long_read(&tunnel->stats.tx_bytes), 170 atomic_long_read(&tunnel->stats.tx_errors), 171 atomic_long_read(&tunnel->stats.rx_packets), 172 atomic_long_read(&tunnel->stats.rx_bytes), 173 atomic_long_read(&tunnel->stats.rx_errors)); 174 } 175 l2tp_dfs_seq_session_show(struct seq_file * m,void * v)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 %u, ns %u\n", session->nr, session->ns); 187 seq_printf(m, " refcnt %d\n", refcount_read(&session->ref_count)); 188 seq_printf(m, " config 0/0/%c/%c/-/%s %08x %u\n", 189 session->recv_seq ? 'R' : '-', 190 session->send_seq ? 'S' : '-', 191 session->lns_mode ? "LNS" : "LAC", 192 0, 193 jiffies_to_msecs(session->reorder_timeout)); 194 seq_printf(m, " offset 0 l2specific %hu/%d\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_puts(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_puts(m, "\n"); 215 } 216 217 seq_printf(m, " %u/%u 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) 227 session->show(m, session); 228 } 229 l2tp_dfs_seq_show(struct seq_file * m,void * v)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 if (!pd->session) 251 l2tp_dfs_seq_tunnel_show(m, pd->tunnel); 252 else 253 l2tp_dfs_seq_session_show(m, pd->session); 254 255 out: 256 return 0; 257 } 258 259 static const struct seq_operations l2tp_dfs_seq_ops = { 260 .start = l2tp_dfs_seq_start, 261 .next = l2tp_dfs_seq_next, 262 .stop = l2tp_dfs_seq_stop, 263 .show = l2tp_dfs_seq_show, 264 }; 265 l2tp_dfs_seq_open(struct inode * inode,struct file * file)266 static int l2tp_dfs_seq_open(struct inode *inode, struct file *file) 267 { 268 struct l2tp_dfs_seq_data *pd; 269 struct seq_file *seq; 270 int rc = -ENOMEM; 271 272 pd = kzalloc(sizeof(*pd), GFP_KERNEL); 273 if (!pd) 274 goto out; 275 276 /* Derive the network namespace from the pid opening the 277 * file. 278 */ 279 pd->net = get_net_ns_by_pid(current->pid); 280 if (IS_ERR(pd->net)) { 281 rc = PTR_ERR(pd->net); 282 goto err_free_pd; 283 } 284 netns_tracker_alloc(pd->net, &pd->ns_tracker, GFP_KERNEL); 285 rc = seq_open(file, &l2tp_dfs_seq_ops); 286 if (rc) 287 goto err_free_net; 288 289 seq = file->private_data; 290 seq->private = pd; 291 292 out: 293 return rc; 294 295 err_free_net: 296 put_net_track(pd->net, &pd->ns_tracker); 297 err_free_pd: 298 kfree(pd); 299 goto out; 300 } 301 l2tp_dfs_seq_release(struct inode * inode,struct file * file)302 static int l2tp_dfs_seq_release(struct inode *inode, struct file *file) 303 { 304 struct l2tp_dfs_seq_data *pd; 305 struct seq_file *seq; 306 307 seq = file->private_data; 308 pd = seq->private; 309 if (pd->net) 310 put_net_track(pd->net, &pd->ns_tracker); 311 kfree(pd); 312 seq_release(inode, file); 313 314 return 0; 315 } 316 317 static const struct file_operations l2tp_dfs_fops = { 318 .owner = THIS_MODULE, 319 .open = l2tp_dfs_seq_open, 320 .read = seq_read, 321 .llseek = seq_lseek, 322 .release = l2tp_dfs_seq_release, 323 }; 324 l2tp_debugfs_init(void)325 static int __init l2tp_debugfs_init(void) 326 { 327 rootdir = debugfs_create_dir("l2tp", NULL); 328 329 debugfs_create_file("tunnels", 0600, rootdir, NULL, &l2tp_dfs_fops); 330 331 pr_info("L2TP debugfs support\n"); 332 333 return 0; 334 } 335 l2tp_debugfs_exit(void)336 static void __exit l2tp_debugfs_exit(void) 337 { 338 debugfs_remove_recursive(rootdir); 339 } 340 341 module_init(l2tp_debugfs_init); 342 module_exit(l2tp_debugfs_exit); 343 344 MODULE_LICENSE("GPL"); 345 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); 346 MODULE_DESCRIPTION("L2TP debugfs driver"); 347 MODULE_VERSION("1.0"); 348