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 int tunnel_idx; /* current tunnel */ 38 int session_idx; /* index of session within current tunnel */ 39 struct l2tp_tunnel *tunnel; 40 struct l2tp_session *session; /* NULL means get next tunnel */ 41 }; 42 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_dec_refcount(pd->tunnel); 48 49 pd->tunnel = l2tp_tunnel_get_nth(pd->net, pd->tunnel_idx); 50 pd->tunnel_idx++; 51 } 52 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_dec_refcount(pd->session); 58 59 pd->session = l2tp_session_get_nth(pd->tunnel, pd->session_idx); 60 pd->session_idx++; 61 62 if (!pd->session) { 63 pd->session_idx = 0; 64 l2tp_dfs_next_tunnel(pd); 65 } 66 } 67 68 static void *l2tp_dfs_seq_start(struct seq_file *m, loff_t *offs) 69 { 70 struct l2tp_dfs_seq_data *pd = SEQ_START_TOKEN; 71 loff_t pos = *offs; 72 73 if (!pos) 74 goto out; 75 76 if (WARN_ON(!m->private)) { 77 pd = NULL; 78 goto out; 79 } 80 pd = m->private; 81 82 if (!pd->tunnel) 83 l2tp_dfs_next_tunnel(pd); 84 else 85 l2tp_dfs_next_session(pd); 86 87 /* NULL tunnel and session indicates end of list */ 88 if (!pd->tunnel && !pd->session) 89 pd = NULL; 90 91 out: 92 return pd; 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_session() 109 * or l2tp_dfs_next_tunnel(). 110 */ 111 if (pd->session) { 112 l2tp_session_dec_refcount(pd->session); 113 pd->session = NULL; 114 } 115 if (pd->tunnel) { 116 l2tp_tunnel_dec_refcount(pd->tunnel); 117 pd->tunnel = NULL; 118 } 119 } 120 121 static void l2tp_dfs_seq_tunnel_show(struct seq_file *m, void *v) 122 { 123 struct l2tp_tunnel *tunnel = v; 124 struct l2tp_session *session; 125 int session_count = 0; 126 int hash; 127 128 rcu_read_lock_bh(); 129 for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { 130 hlist_for_each_entry_rcu(session, &tunnel->session_hlist[hash], hlist) { 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 } 138 rcu_read_unlock_bh(); 139 140 seq_printf(m, "\nTUNNEL %u peer %u", tunnel->tunnel_id, tunnel->peer_tunnel_id); 141 if (tunnel->sock) { 142 struct inet_sock *inet = inet_sk(tunnel->sock); 143 144 #if IS_ENABLED(CONFIG_IPV6) 145 if (tunnel->sock->sk_family == AF_INET6) { 146 const struct ipv6_pinfo *np = inet6_sk(tunnel->sock); 147 148 seq_printf(m, " from %pI6c to %pI6c\n", 149 &np->saddr, &tunnel->sock->sk_v6_daddr); 150 } 151 #endif 152 if (tunnel->sock->sk_family == AF_INET) 153 seq_printf(m, " from %pI4 to %pI4\n", 154 &inet->inet_saddr, &inet->inet_daddr); 155 156 if (tunnel->encap == L2TP_ENCAPTYPE_UDP) 157 seq_printf(m, " source port %hu, dest port %hu\n", 158 ntohs(inet->inet_sport), ntohs(inet->inet_dport)); 159 } 160 seq_printf(m, " L2TPv%d, %s\n", tunnel->version, 161 tunnel->encap == L2TP_ENCAPTYPE_UDP ? "UDP" : 162 tunnel->encap == L2TP_ENCAPTYPE_IP ? "IP" : 163 ""); 164 seq_printf(m, " %d sessions, refcnt %d/%d\n", session_count, 165 tunnel->sock ? refcount_read(&tunnel->sock->sk_refcnt) : 0, 166 refcount_read(&tunnel->ref_count)); 167 seq_printf(m, " %08x rx %ld/%ld/%ld rx %ld/%ld/%ld\n", 168 0, 169 atomic_long_read(&tunnel->stats.tx_packets), 170 atomic_long_read(&tunnel->stats.tx_bytes), 171 atomic_long_read(&tunnel->stats.tx_errors), 172 atomic_long_read(&tunnel->stats.rx_packets), 173 atomic_long_read(&tunnel->stats.rx_bytes), 174 atomic_long_read(&tunnel->stats.rx_errors)); 175 } 176 177 static void l2tp_dfs_seq_session_show(struct seq_file *m, void *v) 178 { 179 struct l2tp_session *session = v; 180 181 seq_printf(m, " SESSION %u, peer %u, %s\n", session->session_id, 182 session->peer_session_id, 183 session->pwtype == L2TP_PWTYPE_ETH ? "ETH" : 184 session->pwtype == L2TP_PWTYPE_PPP ? "PPP" : 185 ""); 186 if (session->send_seq || session->recv_seq) 187 seq_printf(m, " nr %u, ns %u\n", session->nr, session->ns); 188 seq_printf(m, " refcnt %d\n", refcount_read(&session->ref_count)); 189 seq_printf(m, " config 0/0/%c/%c/-/%s %08x %u\n", 190 session->recv_seq ? 'R' : '-', 191 session->send_seq ? 'S' : '-', 192 session->lns_mode ? "LNS" : "LAC", 193 0, 194 jiffies_to_msecs(session->reorder_timeout)); 195 seq_printf(m, " offset 0 l2specific %hu/%d\n", 196 session->l2specific_type, l2tp_get_l2specific_len(session)); 197 if (session->cookie_len) { 198 seq_printf(m, " cookie %02x%02x%02x%02x", 199 session->cookie[0], session->cookie[1], 200 session->cookie[2], session->cookie[3]); 201 if (session->cookie_len == 8) 202 seq_printf(m, "%02x%02x%02x%02x", 203 session->cookie[4], session->cookie[5], 204 session->cookie[6], session->cookie[7]); 205 seq_puts(m, "\n"); 206 } 207 if (session->peer_cookie_len) { 208 seq_printf(m, " peer cookie %02x%02x%02x%02x", 209 session->peer_cookie[0], session->peer_cookie[1], 210 session->peer_cookie[2], session->peer_cookie[3]); 211 if (session->peer_cookie_len == 8) 212 seq_printf(m, "%02x%02x%02x%02x", 213 session->peer_cookie[4], session->peer_cookie[5], 214 session->peer_cookie[6], session->peer_cookie[7]); 215 seq_puts(m, "\n"); 216 } 217 218 seq_printf(m, " %u/%u tx %ld/%ld/%ld rx %ld/%ld/%ld\n", 219 session->nr, session->ns, 220 atomic_long_read(&session->stats.tx_packets), 221 atomic_long_read(&session->stats.tx_bytes), 222 atomic_long_read(&session->stats.tx_errors), 223 atomic_long_read(&session->stats.rx_packets), 224 atomic_long_read(&session->stats.rx_bytes), 225 atomic_long_read(&session->stats.rx_errors)); 226 227 if (session->show) 228 session->show(m, session); 229 } 230 231 static int l2tp_dfs_seq_show(struct seq_file *m, void *v) 232 { 233 struct l2tp_dfs_seq_data *pd = v; 234 235 /* display header on line 1 */ 236 if (v == SEQ_START_TOKEN) { 237 seq_puts(m, "TUNNEL ID, peer ID from IP to IP\n"); 238 seq_puts(m, " L2TPv2/L2TPv3, UDP/IP\n"); 239 seq_puts(m, " sessions session-count, refcnt refcnt/sk->refcnt\n"); 240 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); 241 seq_puts(m, " SESSION ID, peer ID, PWTYPE\n"); 242 seq_puts(m, " refcnt cnt\n"); 243 seq_puts(m, " offset OFFSET l2specific TYPE/LEN\n"); 244 seq_puts(m, " [ cookie ]\n"); 245 seq_puts(m, " [ peer cookie ]\n"); 246 seq_puts(m, " config mtu/mru/rcvseq/sendseq/dataseq/lns debug reorderto\n"); 247 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); 248 goto out; 249 } 250 251 if (!pd->session) 252 l2tp_dfs_seq_tunnel_show(m, pd->tunnel); 253 else 254 l2tp_dfs_seq_session_show(m, pd->session); 255 256 out: 257 return 0; 258 } 259 260 static const struct seq_operations l2tp_dfs_seq_ops = { 261 .start = l2tp_dfs_seq_start, 262 .next = l2tp_dfs_seq_next, 263 .stop = l2tp_dfs_seq_stop, 264 .show = l2tp_dfs_seq_show, 265 }; 266 267 static int l2tp_dfs_seq_open(struct inode *inode, struct file *file) 268 { 269 struct l2tp_dfs_seq_data *pd; 270 struct seq_file *seq; 271 int rc = -ENOMEM; 272 273 pd = kzalloc(sizeof(*pd), GFP_KERNEL); 274 if (!pd) 275 goto out; 276 277 /* Derive the network namespace from the pid opening the 278 * file. 279 */ 280 pd->net = get_net_ns_by_pid(current->pid); 281 if (IS_ERR(pd->net)) { 282 rc = PTR_ERR(pd->net); 283 goto err_free_pd; 284 } 285 netns_tracker_alloc(pd->net, &pd->ns_tracker, GFP_KERNEL); 286 rc = seq_open(file, &l2tp_dfs_seq_ops); 287 if (rc) 288 goto err_free_net; 289 290 seq = file->private_data; 291 seq->private = pd; 292 293 out: 294 return rc; 295 296 err_free_net: 297 put_net_track(pd->net, &pd->ns_tracker); 298 err_free_pd: 299 kfree(pd); 300 goto out; 301 } 302 303 static int l2tp_dfs_seq_release(struct inode *inode, struct file *file) 304 { 305 struct l2tp_dfs_seq_data *pd; 306 struct seq_file *seq; 307 308 seq = file->private_data; 309 pd = seq->private; 310 if (pd->net) 311 put_net_track(pd->net, &pd->ns_tracker); 312 kfree(pd); 313 seq_release(inode, file); 314 315 return 0; 316 } 317 318 static const struct file_operations l2tp_dfs_fops = { 319 .owner = THIS_MODULE, 320 .open = l2tp_dfs_seq_open, 321 .read = seq_read, 322 .llseek = seq_lseek, 323 .release = l2tp_dfs_seq_release, 324 }; 325 326 static int __init l2tp_debugfs_init(void) 327 { 328 rootdir = debugfs_create_dir("l2tp", NULL); 329 330 debugfs_create_file("tunnels", 0600, rootdir, NULL, &l2tp_dfs_fops); 331 332 pr_info("L2TP debugfs support\n"); 333 334 return 0; 335 } 336 337 static void __exit l2tp_debugfs_exit(void) 338 { 339 debugfs_remove_recursive(rootdir); 340 } 341 342 module_init(l2tp_debugfs_init); 343 module_exit(l2tp_debugfs_exit); 344 345 MODULE_LICENSE("GPL"); 346 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); 347 MODULE_DESCRIPTION("L2TP debugfs driver"); 348 MODULE_VERSION("1.0"); 349