1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * L2TP subsystem debugfs 4 * 5 * Copyright (c) 2010 Katalix Systems Ltd 6 */ 7 8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 9 10 #include <linux/module.h> 11 #include <linux/skbuff.h> 12 #include <linux/socket.h> 13 #include <linux/hash.h> 14 #include <linux/l2tp.h> 15 #include <linux/in.h> 16 #include <linux/etherdevice.h> 17 #include <linux/spinlock.h> 18 #include <linux/debugfs.h> 19 #include <net/sock.h> 20 #include <net/ip.h> 21 #include <net/icmp.h> 22 #include <net/udp.h> 23 #include <net/inet_common.h> 24 #include <net/inet_hashtables.h> 25 #include <net/tcp_states.h> 26 #include <net/protocol.h> 27 #include <net/xfrm.h> 28 #include <net/net_namespace.h> 29 #include <net/netns/generic.h> 30 31 #include "l2tp_core.h" 32 33 static struct dentry *rootdir; 34 static struct dentry *tunnels; 35 36 struct l2tp_dfs_seq_data { 37 struct net *net; 38 int tunnel_idx; /* current tunnel */ 39 int session_idx; /* index of session within current tunnel */ 40 struct l2tp_tunnel *tunnel; 41 struct l2tp_session *session; /* NULL means get next tunnel */ 42 }; 43 44 static void l2tp_dfs_next_tunnel(struct l2tp_dfs_seq_data *pd) 45 { 46 /* Drop reference taken during previous invocation */ 47 if (pd->tunnel) 48 l2tp_tunnel_dec_refcount(pd->tunnel); 49 50 pd->tunnel = l2tp_tunnel_get_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 /* Drop reference taken during previous invocation */ 57 if (pd->session) 58 l2tp_session_dec_refcount(pd->session); 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_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 int session_count = 0; 125 int hash; 126 struct hlist_node *walk; 127 struct hlist_node *tmp; 128 129 read_lock_bh(&tunnel->hlist_lock); 130 for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { 131 hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) { 132 struct l2tp_session *session; 133 134 session = hlist_entry(walk, struct l2tp_session, hlist); 135 if (session->session_id == 0) 136 continue; 137 138 session_count++; 139 } 140 } 141 read_unlock_bh(&tunnel->hlist_lock); 142 143 seq_printf(m, "\nTUNNEL %u peer %u", tunnel->tunnel_id, tunnel->peer_tunnel_id); 144 if (tunnel->sock) { 145 struct inet_sock *inet = inet_sk(tunnel->sock); 146 147 #if IS_ENABLED(CONFIG_IPV6) 148 if (tunnel->sock->sk_family == AF_INET6) { 149 const struct ipv6_pinfo *np = inet6_sk(tunnel->sock); 150 151 seq_printf(m, " from %pI6c to %pI6c\n", 152 &np->saddr, &tunnel->sock->sk_v6_daddr); 153 } else 154 #endif 155 seq_printf(m, " from %pI4 to %pI4\n", 156 &inet->inet_saddr, &inet->inet_daddr); 157 if (tunnel->encap == L2TP_ENCAPTYPE_UDP) 158 seq_printf(m, " source port %hu, dest port %hu\n", 159 ntohs(inet->inet_sport), ntohs(inet->inet_dport)); 160 } 161 seq_printf(m, " L2TPv%d, %s\n", tunnel->version, 162 tunnel->encap == L2TP_ENCAPTYPE_UDP ? "UDP" : 163 tunnel->encap == L2TP_ENCAPTYPE_IP ? "IP" : 164 ""); 165 seq_printf(m, " %d sessions, refcnt %d/%d\n", session_count, 166 tunnel->sock ? refcount_read(&tunnel->sock->sk_refcnt) : 0, 167 refcount_read(&tunnel->ref_count)); 168 seq_printf(m, " %08x rx %ld/%ld/%ld rx %ld/%ld/%ld\n", 169 tunnel->debug, 170 atomic_long_read(&tunnel->stats.tx_packets), 171 atomic_long_read(&tunnel->stats.tx_bytes), 172 atomic_long_read(&tunnel->stats.tx_errors), 173 atomic_long_read(&tunnel->stats.rx_packets), 174 atomic_long_read(&tunnel->stats.rx_bytes), 175 atomic_long_read(&tunnel->stats.rx_errors)); 176 } 177 178 static void l2tp_dfs_seq_session_show(struct seq_file *m, void *v) 179 { 180 struct l2tp_session *session = v; 181 182 seq_printf(m, " SESSION %u, peer %u, %s\n", session->session_id, 183 session->peer_session_id, 184 session->pwtype == L2TP_PWTYPE_ETH ? "ETH" : 185 session->pwtype == L2TP_PWTYPE_PPP ? "PPP" : 186 ""); 187 if (session->send_seq || session->recv_seq) 188 seq_printf(m, " nr %hu, ns %hu\n", session->nr, session->ns); 189 seq_printf(m, " refcnt %d\n", refcount_read(&session->ref_count)); 190 seq_printf(m, " config 0/0/%c/%c/-/%s %08x %u\n", 191 session->recv_seq ? 'R' : '-', 192 session->send_seq ? 'S' : '-', 193 session->lns_mode ? "LNS" : "LAC", 194 session->debug, 195 jiffies_to_msecs(session->reorder_timeout)); 196 seq_printf(m, " offset 0 l2specific %hu/%hu\n", 197 session->l2specific_type, l2tp_get_l2specific_len(session)); 198 if (session->cookie_len) { 199 seq_printf(m, " cookie %02x%02x%02x%02x", 200 session->cookie[0], session->cookie[1], 201 session->cookie[2], session->cookie[3]); 202 if (session->cookie_len == 8) 203 seq_printf(m, "%02x%02x%02x%02x", 204 session->cookie[4], session->cookie[5], 205 session->cookie[6], session->cookie[7]); 206 seq_printf(m, "\n"); 207 } 208 if (session->peer_cookie_len) { 209 seq_printf(m, " peer cookie %02x%02x%02x%02x", 210 session->peer_cookie[0], session->peer_cookie[1], 211 session->peer_cookie[2], session->peer_cookie[3]); 212 if (session->peer_cookie_len == 8) 213 seq_printf(m, "%02x%02x%02x%02x", 214 session->peer_cookie[4], session->peer_cookie[5], 215 session->peer_cookie[6], session->peer_cookie[7]); 216 seq_printf(m, "\n"); 217 } 218 219 seq_printf(m, " %hu/%hu tx %ld/%ld/%ld rx %ld/%ld/%ld\n", 220 session->nr, session->ns, 221 atomic_long_read(&session->stats.tx_packets), 222 atomic_long_read(&session->stats.tx_bytes), 223 atomic_long_read(&session->stats.tx_errors), 224 atomic_long_read(&session->stats.rx_packets), 225 atomic_long_read(&session->stats.rx_bytes), 226 atomic_long_read(&session->stats.rx_errors)); 227 228 if (session->show != NULL) 229 session->show(m, session); 230 } 231 232 static int l2tp_dfs_seq_show(struct seq_file *m, void *v) 233 { 234 struct l2tp_dfs_seq_data *pd = v; 235 236 /* display header on line 1 */ 237 if (v == SEQ_START_TOKEN) { 238 seq_puts(m, "TUNNEL ID, peer ID from IP to IP\n"); 239 seq_puts(m, " L2TPv2/L2TPv3, UDP/IP\n"); 240 seq_puts(m, " sessions session-count, refcnt refcnt/sk->refcnt\n"); 241 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); 242 seq_puts(m, " SESSION ID, peer ID, PWTYPE\n"); 243 seq_puts(m, " refcnt cnt\n"); 244 seq_puts(m, " offset OFFSET l2specific TYPE/LEN\n"); 245 seq_puts(m, " [ cookie ]\n"); 246 seq_puts(m, " [ peer cookie ]\n"); 247 seq_puts(m, " config mtu/mru/rcvseq/sendseq/dataseq/lns debug reorderto\n"); 248 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); 249 goto out; 250 } 251 252 if (!pd->session) 253 l2tp_dfs_seq_tunnel_show(m, pd->tunnel); 254 else 255 l2tp_dfs_seq_session_show(m, pd->session); 256 257 out: 258 return 0; 259 } 260 261 static const struct seq_operations l2tp_dfs_seq_ops = { 262 .start = l2tp_dfs_seq_start, 263 .next = l2tp_dfs_seq_next, 264 .stop = l2tp_dfs_seq_stop, 265 .show = l2tp_dfs_seq_show, 266 }; 267 268 static int l2tp_dfs_seq_open(struct inode *inode, struct file *file) 269 { 270 struct l2tp_dfs_seq_data *pd; 271 struct seq_file *seq; 272 int rc = -ENOMEM; 273 274 pd = kzalloc(sizeof(*pd), GFP_KERNEL); 275 if (pd == NULL) 276 goto out; 277 278 /* Derive the network namespace from the pid opening the 279 * file. 280 */ 281 pd->net = get_net_ns_by_pid(current->pid); 282 if (IS_ERR(pd->net)) { 283 rc = PTR_ERR(pd->net); 284 goto err_free_pd; 285 } 286 287 rc = seq_open(file, &l2tp_dfs_seq_ops); 288 if (rc) 289 goto err_free_net; 290 291 seq = file->private_data; 292 seq->private = pd; 293 294 out: 295 return rc; 296 297 err_free_net: 298 put_net(pd->net); 299 err_free_pd: 300 kfree(pd); 301 goto out; 302 } 303 304 static int l2tp_dfs_seq_release(struct inode *inode, struct file *file) 305 { 306 struct l2tp_dfs_seq_data *pd; 307 struct seq_file *seq; 308 309 seq = file->private_data; 310 pd = seq->private; 311 if (pd->net) 312 put_net(pd->net); 313 kfree(pd); 314 seq_release(inode, file); 315 316 return 0; 317 } 318 319 static const struct file_operations l2tp_dfs_fops = { 320 .owner = THIS_MODULE, 321 .open = l2tp_dfs_seq_open, 322 .read = seq_read, 323 .llseek = seq_lseek, 324 .release = l2tp_dfs_seq_release, 325 }; 326 327 static int __init l2tp_debugfs_init(void) 328 { 329 int rc = 0; 330 331 rootdir = debugfs_create_dir("l2tp", NULL); 332 if (IS_ERR(rootdir)) { 333 rc = PTR_ERR(rootdir); 334 rootdir = NULL; 335 goto out; 336 } 337 338 tunnels = debugfs_create_file("tunnels", 0600, rootdir, NULL, &l2tp_dfs_fops); 339 if (tunnels == NULL) 340 rc = -EIO; 341 342 pr_info("L2TP debugfs support\n"); 343 344 out: 345 if (rc) 346 pr_warn("unable to init\n"); 347 348 return rc; 349 } 350 351 static void __exit l2tp_debugfs_exit(void) 352 { 353 debugfs_remove(tunnels); 354 debugfs_remove(rootdir); 355 } 356 357 module_init(l2tp_debugfs_init); 358 module_exit(l2tp_debugfs_exit); 359 360 MODULE_LICENSE("GPL"); 361 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); 362 MODULE_DESCRIPTION("L2TP debugfs driver"); 363 MODULE_VERSION("1.0"); 364