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 int tunnel_idx; /* current tunnel */ 37 int session_idx; /* index of session within current tunnel */ 38 struct l2tp_tunnel *tunnel; 39 struct l2tp_session *session; /* NULL means get next tunnel */ 40 }; 41 42 static void l2tp_dfs_next_tunnel(struct l2tp_dfs_seq_data *pd) 43 { 44 /* Drop reference taken during previous invocation */ 45 if (pd->tunnel) 46 l2tp_tunnel_dec_refcount(pd->tunnel); 47 48 pd->tunnel = l2tp_tunnel_get_nth(pd->net, pd->tunnel_idx); 49 pd->tunnel_idx++; 50 } 51 52 static void l2tp_dfs_next_session(struct l2tp_dfs_seq_data *pd) 53 { 54 /* Drop reference taken during previous invocation */ 55 if (pd->session) 56 l2tp_session_dec_refcount(pd->session); 57 58 pd->session = l2tp_session_get_nth(pd->tunnel, pd->session_idx); 59 pd->session_idx++; 60 61 if (!pd->session) { 62 pd->session_idx = 0; 63 l2tp_dfs_next_tunnel(pd); 64 } 65 } 66 67 static void *l2tp_dfs_seq_start(struct seq_file *m, loff_t *offs) 68 { 69 struct l2tp_dfs_seq_data *pd = SEQ_START_TOKEN; 70 loff_t pos = *offs; 71 72 if (!pos) 73 goto out; 74 75 if (WARN_ON(!m->private)) { 76 pd = NULL; 77 goto out; 78 } 79 pd = m->private; 80 81 if (!pd->tunnel) 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 && !pd->session) 88 pd = NULL; 89 90 out: 91 return pd; 92 } 93 94 static void *l2tp_dfs_seq_next(struct seq_file *m, void *v, loff_t *pos) 95 { 96 (*pos)++; 97 return NULL; 98 } 99 100 static void l2tp_dfs_seq_stop(struct seq_file *p, void *v) 101 { 102 struct l2tp_dfs_seq_data *pd = v; 103 104 if (!pd || pd == SEQ_START_TOKEN) 105 return; 106 107 /* Drop reference taken by last invocation of l2tp_dfs_next_session() 108 * or l2tp_dfs_next_tunnel(). 109 */ 110 if (pd->session) { 111 l2tp_session_dec_refcount(pd->session); 112 pd->session = NULL; 113 } 114 if (pd->tunnel) { 115 l2tp_tunnel_dec_refcount(pd->tunnel); 116 pd->tunnel = NULL; 117 } 118 } 119 120 static void l2tp_dfs_seq_tunnel_show(struct seq_file *m, void *v) 121 { 122 struct l2tp_tunnel *tunnel = v; 123 int session_count = 0; 124 int hash; 125 struct hlist_node *walk; 126 struct hlist_node *tmp; 127 128 read_lock_bh(&tunnel->hlist_lock); 129 for (hash = 0; hash < L2TP_HASH_SIZE; hash++) { 130 hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) { 131 struct l2tp_session *session; 132 133 session = hlist_entry(walk, struct l2tp_session, hlist); 134 if (session->session_id == 0) 135 continue; 136 137 session_count++; 138 } 139 } 140 read_unlock_bh(&tunnel->hlist_lock); 141 142 seq_printf(m, "\nTUNNEL %u peer %u", tunnel->tunnel_id, tunnel->peer_tunnel_id); 143 if (tunnel->sock) { 144 struct inet_sock *inet = inet_sk(tunnel->sock); 145 146 #if IS_ENABLED(CONFIG_IPV6) 147 if (tunnel->sock->sk_family == AF_INET6) { 148 const struct ipv6_pinfo *np = inet6_sk(tunnel->sock); 149 150 seq_printf(m, " from %pI6c to %pI6c\n", 151 &np->saddr, &tunnel->sock->sk_v6_daddr); 152 } 153 #endif 154 if (tunnel->sock->sk_family == AF_INET) 155 seq_printf(m, " from %pI4 to %pI4\n", 156 &inet->inet_saddr, &inet->inet_daddr); 157 158 if (tunnel->encap == L2TP_ENCAPTYPE_UDP) 159 seq_printf(m, " source port %hu, dest port %hu\n", 160 ntohs(inet->inet_sport), ntohs(inet->inet_dport)); 161 } 162 seq_printf(m, " L2TPv%d, %s\n", tunnel->version, 163 tunnel->encap == L2TP_ENCAPTYPE_UDP ? "UDP" : 164 tunnel->encap == L2TP_ENCAPTYPE_IP ? "IP" : 165 ""); 166 seq_printf(m, " %d sessions, refcnt %d/%d\n", session_count, 167 tunnel->sock ? refcount_read(&tunnel->sock->sk_refcnt) : 0, 168 refcount_read(&tunnel->ref_count)); 169 seq_printf(m, " %08x rx %ld/%ld/%ld rx %ld/%ld/%ld\n", 170 0, 171 atomic_long_read(&tunnel->stats.tx_packets), 172 atomic_long_read(&tunnel->stats.tx_bytes), 173 atomic_long_read(&tunnel->stats.tx_errors), 174 atomic_long_read(&tunnel->stats.rx_packets), 175 atomic_long_read(&tunnel->stats.rx_bytes), 176 atomic_long_read(&tunnel->stats.rx_errors)); 177 } 178 179 static void l2tp_dfs_seq_session_show(struct seq_file *m, void *v) 180 { 181 struct l2tp_session *session = v; 182 183 seq_printf(m, " SESSION %u, peer %u, %s\n", session->session_id, 184 session->peer_session_id, 185 session->pwtype == L2TP_PWTYPE_ETH ? "ETH" : 186 session->pwtype == L2TP_PWTYPE_PPP ? "PPP" : 187 ""); 188 if (session->send_seq || session->recv_seq) 189 seq_printf(m, " nr %hu, ns %hu\n", session->nr, session->ns); 190 seq_printf(m, " refcnt %d\n", refcount_read(&session->ref_count)); 191 seq_printf(m, " config 0/0/%c/%c/-/%s %08x %u\n", 192 session->recv_seq ? 'R' : '-', 193 session->send_seq ? 'S' : '-', 194 session->lns_mode ? "LNS" : "LAC", 195 0, 196 jiffies_to_msecs(session->reorder_timeout)); 197 seq_printf(m, " offset 0 l2specific %hu/%hu\n", 198 session->l2specific_type, l2tp_get_l2specific_len(session)); 199 if (session->cookie_len) { 200 seq_printf(m, " cookie %02x%02x%02x%02x", 201 session->cookie[0], session->cookie[1], 202 session->cookie[2], session->cookie[3]); 203 if (session->cookie_len == 8) 204 seq_printf(m, "%02x%02x%02x%02x", 205 session->cookie[4], session->cookie[5], 206 session->cookie[6], session->cookie[7]); 207 seq_puts(m, "\n"); 208 } 209 if (session->peer_cookie_len) { 210 seq_printf(m, " peer cookie %02x%02x%02x%02x", 211 session->peer_cookie[0], session->peer_cookie[1], 212 session->peer_cookie[2], session->peer_cookie[3]); 213 if (session->peer_cookie_len == 8) 214 seq_printf(m, "%02x%02x%02x%02x", 215 session->peer_cookie[4], session->peer_cookie[5], 216 session->peer_cookie[6], session->peer_cookie[7]); 217 seq_puts(m, "\n"); 218 } 219 220 seq_printf(m, " %hu/%hu tx %ld/%ld/%ld rx %ld/%ld/%ld\n", 221 session->nr, session->ns, 222 atomic_long_read(&session->stats.tx_packets), 223 atomic_long_read(&session->stats.tx_bytes), 224 atomic_long_read(&session->stats.tx_errors), 225 atomic_long_read(&session->stats.rx_packets), 226 atomic_long_read(&session->stats.rx_bytes), 227 atomic_long_read(&session->stats.rx_errors)); 228 229 if (session->show) 230 session->show(m, session); 231 } 232 233 static int l2tp_dfs_seq_show(struct seq_file *m, void *v) 234 { 235 struct l2tp_dfs_seq_data *pd = v; 236 237 /* display header on line 1 */ 238 if (v == SEQ_START_TOKEN) { 239 seq_puts(m, "TUNNEL ID, peer ID from IP to IP\n"); 240 seq_puts(m, " L2TPv2/L2TPv3, UDP/IP\n"); 241 seq_puts(m, " sessions session-count, refcnt refcnt/sk->refcnt\n"); 242 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); 243 seq_puts(m, " SESSION ID, peer ID, PWTYPE\n"); 244 seq_puts(m, " refcnt cnt\n"); 245 seq_puts(m, " offset OFFSET l2specific TYPE/LEN\n"); 246 seq_puts(m, " [ cookie ]\n"); 247 seq_puts(m, " [ peer cookie ]\n"); 248 seq_puts(m, " config mtu/mru/rcvseq/sendseq/dataseq/lns debug reorderto\n"); 249 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); 250 goto out; 251 } 252 253 if (!pd->session) 254 l2tp_dfs_seq_tunnel_show(m, pd->tunnel); 255 else 256 l2tp_dfs_seq_session_show(m, pd->session); 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) 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 rootdir = debugfs_create_dir("l2tp", NULL); 331 332 debugfs_create_file("tunnels", 0600, rootdir, NULL, &l2tp_dfs_fops); 333 334 pr_info("L2TP debugfs support\n"); 335 336 return 0; 337 } 338 339 static void __exit l2tp_debugfs_exit(void) 340 { 341 debugfs_remove_recursive(rootdir); 342 } 343 344 module_init(l2tp_debugfs_init); 345 module_exit(l2tp_debugfs_exit); 346 347 MODULE_LICENSE("GPL"); 348 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); 349 MODULE_DESCRIPTION("L2TP debugfs driver"); 350 MODULE_VERSION("1.0"); 351