1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /***************************************************************************** 3 * Linux PPP over L2TP (PPPoX/PPPoL2TP) Sockets 4 * 5 * PPPoX --- Generic PPP encapsulation socket family 6 * PPPoL2TP --- PPP over L2TP (RFC 2661) 7 * 8 * Version: 2.0.0 9 * 10 * Authors: James Chapman (jchapman@katalix.com) 11 * 12 * Based on original work by Martijn van Oosterhout <kleptog@svana.org> 13 * 14 * License: 15 */ 16 17 /* This driver handles only L2TP data frames; control frames are handled by a 18 * userspace application. 19 * 20 * To send data in an L2TP session, userspace opens a PPPoL2TP socket and 21 * attaches it to a bound UDP socket with local tunnel_id / session_id and 22 * peer tunnel_id / session_id set. Data can then be sent or received using 23 * regular socket sendmsg() / recvmsg() calls. Kernel parameters of the socket 24 * can be read or modified using ioctl() or [gs]etsockopt() calls. 25 * 26 * When a PPPoL2TP socket is connected with local and peer session_id values 27 * zero, the socket is treated as a special tunnel management socket. 28 * 29 * Here's example userspace code to create a socket for sending/receiving data 30 * over an L2TP session:- 31 * 32 * struct sockaddr_pppol2tp sax; 33 * int fd; 34 * int session_fd; 35 * 36 * fd = socket(AF_PPPOX, SOCK_DGRAM, PX_PROTO_OL2TP); 37 * 38 * sax.sa_family = AF_PPPOX; 39 * sax.sa_protocol = PX_PROTO_OL2TP; 40 * sax.pppol2tp.fd = tunnel_fd; // bound UDP socket 41 * sax.pppol2tp.addr.sin_addr.s_addr = addr->sin_addr.s_addr; 42 * sax.pppol2tp.addr.sin_port = addr->sin_port; 43 * sax.pppol2tp.addr.sin_family = AF_INET; 44 * sax.pppol2tp.s_tunnel = tunnel_id; 45 * sax.pppol2tp.s_session = session_id; 46 * sax.pppol2tp.d_tunnel = peer_tunnel_id; 47 * sax.pppol2tp.d_session = peer_session_id; 48 * 49 * session_fd = connect(fd, (struct sockaddr *)&sax, sizeof(sax)); 50 * 51 * A pppd plugin that allows PPP traffic to be carried over L2TP using 52 * this driver is available from the OpenL2TP project at 53 * http://openl2tp.sourceforge.net. 54 */ 55 56 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 57 58 #include <linux/module.h> 59 #include <linux/string.h> 60 #include <linux/list.h> 61 #include <linux/uaccess.h> 62 63 #include <linux/kernel.h> 64 #include <linux/spinlock.h> 65 #include <linux/kthread.h> 66 #include <linux/sched.h> 67 #include <linux/slab.h> 68 #include <linux/errno.h> 69 #include <linux/jiffies.h> 70 71 #include <linux/netdevice.h> 72 #include <linux/net.h> 73 #include <linux/inetdevice.h> 74 #include <linux/skbuff.h> 75 #include <linux/init.h> 76 #include <linux/ip.h> 77 #include <linux/udp.h> 78 #include <linux/if_pppox.h> 79 #include <linux/if_pppol2tp.h> 80 #include <net/sock.h> 81 #include <linux/ppp_channel.h> 82 #include <linux/ppp_defs.h> 83 #include <linux/ppp-ioctl.h> 84 #include <linux/file.h> 85 #include <linux/hash.h> 86 #include <linux/sort.h> 87 #include <linux/proc_fs.h> 88 #include <linux/l2tp.h> 89 #include <linux/nsproxy.h> 90 #include <net/net_namespace.h> 91 #include <net/netns/generic.h> 92 #include <net/ip.h> 93 #include <net/udp.h> 94 #include <net/inet_common.h> 95 96 #include <asm/byteorder.h> 97 #include <linux/atomic.h> 98 99 #include "l2tp_core.h" 100 101 #define PPPOL2TP_DRV_VERSION "V2.0" 102 103 /* Space for UDP, L2TP and PPP headers */ 104 #define PPPOL2TP_HEADER_OVERHEAD 40 105 106 /* Number of bytes to build transmit L2TP headers. 107 * Unfortunately the size is different depending on whether sequence numbers 108 * are enabled. 109 */ 110 #define PPPOL2TP_L2TP_HDR_SIZE_SEQ 10 111 #define PPPOL2TP_L2TP_HDR_SIZE_NOSEQ 6 112 113 /* Private data of each session. This data lives at the end of struct 114 * l2tp_session, referenced via session->priv[]. 115 */ 116 struct pppol2tp_session { 117 int owner; /* pid that opened the socket */ 118 119 struct mutex sk_lock; /* Protects .sk */ 120 struct sock __rcu *sk; /* Pointer to the session PPPoX socket */ 121 struct sock *__sk; /* Copy of .sk, for cleanup */ 122 }; 123 124 static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb); 125 126 static const struct ppp_channel_ops pppol2tp_chan_ops = { 127 .start_xmit = pppol2tp_xmit, 128 }; 129 130 static const struct proto_ops pppol2tp_ops; 131 132 /* Retrieves the pppol2tp socket associated to a session. 133 * A reference is held on the returned socket, so this function must be paired 134 * with sock_put(). 135 */ 136 static struct sock *pppol2tp_session_get_sock(struct l2tp_session *session) 137 { 138 struct pppol2tp_session *ps = l2tp_session_priv(session); 139 struct sock *sk; 140 141 rcu_read_lock(); 142 sk = rcu_dereference(ps->sk); 143 if (sk) 144 sock_hold(sk); 145 rcu_read_unlock(); 146 147 return sk; 148 } 149 150 /* Helpers to obtain tunnel/session contexts from sockets. 151 */ 152 static struct l2tp_session *pppol2tp_sock_to_session(struct sock *sk) 153 { 154 struct l2tp_session *session; 155 156 if (!sk) 157 return NULL; 158 159 rcu_read_lock(); 160 session = rcu_dereference_sk_user_data(sk); 161 if (session && refcount_inc_not_zero(&session->ref_count)) { 162 rcu_read_unlock(); 163 WARN_ON_ONCE(session->magic != L2TP_SESSION_MAGIC); 164 return session; 165 } 166 rcu_read_unlock(); 167 168 return NULL; 169 } 170 171 /***************************************************************************** 172 * Receive data handling 173 *****************************************************************************/ 174 175 /* Receive message. This is the recvmsg for the PPPoL2TP socket. 176 */ 177 static int pppol2tp_recvmsg(struct socket *sock, struct msghdr *msg, 178 size_t len, int flags) 179 { 180 int err; 181 struct sk_buff *skb; 182 struct sock *sk = sock->sk; 183 184 err = -EIO; 185 if (sk->sk_state & PPPOX_BOUND) 186 goto end; 187 188 err = 0; 189 skb = skb_recv_datagram(sk, flags, &err); 190 if (!skb) 191 goto end; 192 193 if (len > skb->len) 194 len = skb->len; 195 else if (len < skb->len) 196 msg->msg_flags |= MSG_TRUNC; 197 198 err = skb_copy_datagram_msg(skb, 0, msg, len); 199 if (likely(err == 0)) 200 err = len; 201 202 kfree_skb(skb); 203 end: 204 return err; 205 } 206 207 static void pppol2tp_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len) 208 { 209 struct pppol2tp_session *ps = l2tp_session_priv(session); 210 struct sock *sk = NULL; 211 212 /* If the socket is bound, send it in to PPP's input queue. Otherwise 213 * queue it on the session socket. 214 */ 215 rcu_read_lock(); 216 sk = rcu_dereference(ps->sk); 217 if (!sk) 218 goto no_sock; 219 220 /* If the first two bytes are 0xFF03, consider that it is the PPP's 221 * Address and Control fields and skip them. The L2TP module has always 222 * worked this way, although, in theory, the use of these fields should 223 * be negotiated and handled at the PPP layer. These fields are 224 * constant: 0xFF is the All-Stations Address and 0x03 the Unnumbered 225 * Information command with Poll/Final bit set to zero (RFC 1662). 226 */ 227 if (pskb_may_pull(skb, 2) && skb->data[0] == PPP_ALLSTATIONS && 228 skb->data[1] == PPP_UI) 229 skb_pull(skb, 2); 230 231 if (sk->sk_state & PPPOX_BOUND) { 232 struct pppox_sock *po; 233 234 po = pppox_sk(sk); 235 ppp_input(&po->chan, skb); 236 } else { 237 if (sock_queue_rcv_skb(sk, skb) < 0) { 238 atomic_long_inc(&session->stats.rx_errors); 239 kfree_skb(skb); 240 } 241 } 242 rcu_read_unlock(); 243 244 return; 245 246 no_sock: 247 rcu_read_unlock(); 248 pr_warn_ratelimited("%s: no socket in recv\n", session->name); 249 kfree_skb(skb); 250 } 251 252 /************************************************************************ 253 * Transmit handling 254 ***********************************************************************/ 255 256 /* This is the sendmsg for the PPPoL2TP pppol2tp_session socket. We come here 257 * when a user application does a sendmsg() on the session socket. L2TP and 258 * PPP headers must be inserted into the user's data. 259 */ 260 static int pppol2tp_sendmsg(struct socket *sock, struct msghdr *m, 261 size_t total_len) 262 { 263 struct sock *sk = sock->sk; 264 struct sk_buff *skb; 265 int error; 266 struct l2tp_session *session; 267 struct l2tp_tunnel *tunnel; 268 int uhlen; 269 270 error = -ENOTCONN; 271 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) 272 goto error; 273 274 /* Get session and tunnel contexts */ 275 error = -EBADF; 276 session = pppol2tp_sock_to_session(sk); 277 if (!session) 278 goto error; 279 280 tunnel = session->tunnel; 281 282 uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; 283 284 /* Allocate a socket buffer */ 285 error = -ENOMEM; 286 skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) + 287 uhlen + session->hdr_len + 288 2 + total_len, /* 2 bytes for PPP_ALLSTATIONS & PPP_UI */ 289 0, GFP_KERNEL); 290 if (!skb) 291 goto error_put_sess; 292 293 /* Reserve space for headers. */ 294 skb_reserve(skb, NET_SKB_PAD); 295 skb_reset_network_header(skb); 296 skb_reserve(skb, sizeof(struct iphdr)); 297 skb_reset_transport_header(skb); 298 skb_reserve(skb, uhlen); 299 300 /* Add PPP header */ 301 skb->data[0] = PPP_ALLSTATIONS; 302 skb->data[1] = PPP_UI; 303 skb_put(skb, 2); 304 305 /* Copy user data into skb */ 306 error = memcpy_from_msg(skb_put(skb, total_len), m, total_len); 307 if (error < 0) { 308 kfree_skb(skb); 309 goto error_put_sess; 310 } 311 312 local_bh_disable(); 313 l2tp_xmit_skb(session, skb); 314 local_bh_enable(); 315 316 l2tp_session_put(session); 317 318 return total_len; 319 320 error_put_sess: 321 l2tp_session_put(session); 322 error: 323 return error; 324 } 325 326 /* Transmit function called by generic PPP driver. Sends PPP frame 327 * over PPPoL2TP socket. 328 * 329 * This is almost the same as pppol2tp_sendmsg(), but rather than 330 * being called with a msghdr from userspace, it is called with a skb 331 * from the kernel. 332 * 333 * The supplied skb from ppp doesn't have enough headroom for the 334 * insertion of L2TP, UDP and IP headers so we need to allocate more 335 * headroom in the skb. This will create a cloned skb. But we must be 336 * careful in the error case because the caller will expect to free 337 * the skb it supplied, not our cloned skb. So we take care to always 338 * leave the original skb unfreed if we return an error. 339 */ 340 static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb) 341 { 342 struct sock *sk = (struct sock *)chan->private; 343 struct l2tp_session *session; 344 struct l2tp_tunnel *tunnel; 345 int uhlen, headroom; 346 347 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) 348 goto abort; 349 350 /* Get session and tunnel contexts from the socket */ 351 session = pppol2tp_sock_to_session(sk); 352 if (!session) 353 goto abort; 354 355 tunnel = session->tunnel; 356 357 uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; 358 headroom = NET_SKB_PAD + 359 sizeof(struct iphdr) + /* IP header */ 360 uhlen + /* UDP header (if L2TP_ENCAPTYPE_UDP) */ 361 session->hdr_len + /* L2TP header */ 362 2; /* 2 bytes for PPP_ALLSTATIONS & PPP_UI */ 363 if (skb_cow_head(skb, headroom)) 364 goto abort_put_sess; 365 366 /* Setup PPP header */ 367 __skb_push(skb, 2); 368 skb->data[0] = PPP_ALLSTATIONS; 369 skb->data[1] = PPP_UI; 370 371 local_bh_disable(); 372 l2tp_xmit_skb(session, skb); 373 local_bh_enable(); 374 375 l2tp_session_put(session); 376 377 return 1; 378 379 abort_put_sess: 380 l2tp_session_put(session); 381 abort: 382 /* Free the original skb */ 383 kfree_skb(skb); 384 return 1; 385 } 386 387 /***************************************************************************** 388 * Session (and tunnel control) socket create/destroy. 389 *****************************************************************************/ 390 391 /* Really kill the session socket. (Called from sock_put() if 392 * refcnt == 0.) 393 */ 394 static void pppol2tp_session_destruct(struct sock *sk) 395 { 396 skb_queue_purge(&sk->sk_receive_queue); 397 skb_queue_purge(&sk->sk_write_queue); 398 } 399 400 static void pppol2tp_session_close(struct l2tp_session *session) 401 { 402 struct pppol2tp_session *ps; 403 404 ps = l2tp_session_priv(session); 405 mutex_lock(&ps->sk_lock); 406 ps->__sk = rcu_dereference_protected(ps->sk, 407 lockdep_is_held(&ps->sk_lock)); 408 RCU_INIT_POINTER(ps->sk, NULL); 409 mutex_unlock(&ps->sk_lock); 410 if (ps->__sk) { 411 /* detach socket */ 412 rcu_assign_sk_user_data(ps->__sk, NULL); 413 sock_put(ps->__sk); 414 415 /* drop ref taken when we referenced socket via sk_user_data */ 416 l2tp_session_put(session); 417 } 418 } 419 420 /* Called when the PPPoX socket (session) is closed. 421 */ 422 static int pppol2tp_release(struct socket *sock) 423 { 424 struct sock *sk = sock->sk; 425 struct l2tp_session *session; 426 int error; 427 428 if (!sk) 429 return 0; 430 431 error = -EBADF; 432 lock_sock(sk); 433 if (sock_flag(sk, SOCK_DEAD) != 0) 434 goto error; 435 436 pppox_unbind_sock(sk); 437 438 /* Signal the death of the socket. */ 439 sk->sk_state = PPPOX_DEAD; 440 sock_orphan(sk); 441 sock->sk = NULL; 442 443 session = pppol2tp_sock_to_session(sk); 444 if (session) { 445 l2tp_session_delete(session); 446 /* drop ref taken by pppol2tp_sock_to_session */ 447 l2tp_session_put(session); 448 } 449 450 release_sock(sk); 451 452 sock_put(sk); 453 454 return 0; 455 456 error: 457 release_sock(sk); 458 return error; 459 } 460 461 static struct proto pppol2tp_sk_proto = { 462 .name = "PPPOL2TP", 463 .owner = THIS_MODULE, 464 .obj_size = sizeof(struct pppox_sock), 465 }; 466 467 static int pppol2tp_backlog_recv(struct sock *sk, struct sk_buff *skb) 468 { 469 int rc; 470 471 rc = l2tp_udp_encap_recv(sk, skb); 472 if (rc) 473 kfree_skb(skb); 474 475 return NET_RX_SUCCESS; 476 } 477 478 /* socket() handler. Initialize a new struct sock. 479 */ 480 static int pppol2tp_create(struct net *net, struct socket *sock, int kern) 481 { 482 int error = -ENOMEM; 483 struct sock *sk; 484 485 sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppol2tp_sk_proto, kern); 486 if (!sk) 487 goto out; 488 489 sock_init_data(sock, sk); 490 sock_set_flag(sk, SOCK_RCU_FREE); 491 492 sock->state = SS_UNCONNECTED; 493 sock->ops = &pppol2tp_ops; 494 495 sk->sk_backlog_rcv = pppol2tp_backlog_recv; 496 sk->sk_protocol = PX_PROTO_OL2TP; 497 sk->sk_family = PF_PPPOX; 498 sk->sk_state = PPPOX_NONE; 499 sk->sk_type = SOCK_STREAM; 500 sk->sk_destruct = pppol2tp_session_destruct; 501 502 error = 0; 503 504 out: 505 return error; 506 } 507 508 static void pppol2tp_show(struct seq_file *m, void *arg) 509 { 510 struct l2tp_session *session = arg; 511 struct sock *sk; 512 513 sk = pppol2tp_session_get_sock(session); 514 if (sk) { 515 struct pppox_sock *po = pppox_sk(sk); 516 517 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan)); 518 sock_put(sk); 519 } 520 } 521 522 static void pppol2tp_session_init(struct l2tp_session *session) 523 { 524 struct pppol2tp_session *ps; 525 526 session->recv_skb = pppol2tp_recv; 527 session->session_close = pppol2tp_session_close; 528 if (IS_ENABLED(CONFIG_L2TP_DEBUGFS)) 529 session->show = pppol2tp_show; 530 531 ps = l2tp_session_priv(session); 532 mutex_init(&ps->sk_lock); 533 ps->owner = current->pid; 534 } 535 536 struct l2tp_connect_info { 537 u8 version; 538 int fd; 539 u32 tunnel_id; 540 u32 peer_tunnel_id; 541 u32 session_id; 542 u32 peer_session_id; 543 }; 544 545 static int pppol2tp_sockaddr_get_info(const void *sa, int sa_len, 546 struct l2tp_connect_info *info) 547 { 548 switch (sa_len) { 549 case sizeof(struct sockaddr_pppol2tp): 550 { 551 const struct sockaddr_pppol2tp *sa_v2in4 = sa; 552 553 if (sa_v2in4->sa_protocol != PX_PROTO_OL2TP) 554 return -EINVAL; 555 556 info->version = 2; 557 info->fd = sa_v2in4->pppol2tp.fd; 558 info->tunnel_id = sa_v2in4->pppol2tp.s_tunnel; 559 info->peer_tunnel_id = sa_v2in4->pppol2tp.d_tunnel; 560 info->session_id = sa_v2in4->pppol2tp.s_session; 561 info->peer_session_id = sa_v2in4->pppol2tp.d_session; 562 563 break; 564 } 565 case sizeof(struct sockaddr_pppol2tpv3): 566 { 567 const struct sockaddr_pppol2tpv3 *sa_v3in4 = sa; 568 569 if (sa_v3in4->sa_protocol != PX_PROTO_OL2TP) 570 return -EINVAL; 571 572 info->version = 3; 573 info->fd = sa_v3in4->pppol2tp.fd; 574 info->tunnel_id = sa_v3in4->pppol2tp.s_tunnel; 575 info->peer_tunnel_id = sa_v3in4->pppol2tp.d_tunnel; 576 info->session_id = sa_v3in4->pppol2tp.s_session; 577 info->peer_session_id = sa_v3in4->pppol2tp.d_session; 578 579 break; 580 } 581 case sizeof(struct sockaddr_pppol2tpin6): 582 { 583 const struct sockaddr_pppol2tpin6 *sa_v2in6 = sa; 584 585 if (sa_v2in6->sa_protocol != PX_PROTO_OL2TP) 586 return -EINVAL; 587 588 info->version = 2; 589 info->fd = sa_v2in6->pppol2tp.fd; 590 info->tunnel_id = sa_v2in6->pppol2tp.s_tunnel; 591 info->peer_tunnel_id = sa_v2in6->pppol2tp.d_tunnel; 592 info->session_id = sa_v2in6->pppol2tp.s_session; 593 info->peer_session_id = sa_v2in6->pppol2tp.d_session; 594 595 break; 596 } 597 case sizeof(struct sockaddr_pppol2tpv3in6): 598 { 599 const struct sockaddr_pppol2tpv3in6 *sa_v3in6 = sa; 600 601 if (sa_v3in6->sa_protocol != PX_PROTO_OL2TP) 602 return -EINVAL; 603 604 info->version = 3; 605 info->fd = sa_v3in6->pppol2tp.fd; 606 info->tunnel_id = sa_v3in6->pppol2tp.s_tunnel; 607 info->peer_tunnel_id = sa_v3in6->pppol2tp.d_tunnel; 608 info->session_id = sa_v3in6->pppol2tp.s_session; 609 info->peer_session_id = sa_v3in6->pppol2tp.d_session; 610 611 break; 612 } 613 default: 614 return -EINVAL; 615 } 616 617 return 0; 618 } 619 620 /* Rough estimation of the maximum payload size a tunnel can transmit without 621 * fragmenting at the lower IP layer. Assumes L2TPv2 with sequence 622 * numbers and no IP option. Not quite accurate, but the result is mostly 623 * unused anyway. 624 */ 625 static int pppol2tp_tunnel_mtu(const struct l2tp_tunnel *tunnel) 626 { 627 int mtu; 628 629 mtu = l2tp_tunnel_dst_mtu(tunnel); 630 if (mtu <= PPPOL2TP_HEADER_OVERHEAD) 631 return 1500 - PPPOL2TP_HEADER_OVERHEAD; 632 633 return mtu - PPPOL2TP_HEADER_OVERHEAD; 634 } 635 636 static struct l2tp_tunnel *pppol2tp_tunnel_get(struct net *net, 637 const struct l2tp_connect_info *info, 638 bool *new_tunnel) 639 { 640 struct l2tp_tunnel *tunnel; 641 int error; 642 643 *new_tunnel = false; 644 645 tunnel = l2tp_tunnel_get(net, info->tunnel_id); 646 647 /* Special case: create tunnel context if session_id and 648 * peer_session_id is 0. Otherwise look up tunnel using supplied 649 * tunnel id. 650 */ 651 if (!info->session_id && !info->peer_session_id) { 652 if (!tunnel) { 653 struct l2tp_tunnel_cfg tcfg = { 654 .encap = L2TP_ENCAPTYPE_UDP, 655 }; 656 657 /* Prevent l2tp_tunnel_register() from trying to set up 658 * a kernel socket. 659 */ 660 if (info->fd < 0) 661 return ERR_PTR(-EBADF); 662 663 error = l2tp_tunnel_create(info->fd, 664 info->version, 665 info->tunnel_id, 666 info->peer_tunnel_id, &tcfg, 667 &tunnel); 668 if (error < 0) 669 return ERR_PTR(error); 670 671 refcount_inc(&tunnel->ref_count); 672 error = l2tp_tunnel_register(tunnel, net, &tcfg); 673 if (error < 0) { 674 kfree(tunnel); 675 return ERR_PTR(error); 676 } 677 678 *new_tunnel = true; 679 } 680 } else { 681 /* Error if we can't find the tunnel */ 682 if (!tunnel) 683 return ERR_PTR(-ENOENT); 684 685 /* Error if socket is not prepped */ 686 if (!tunnel->sock) { 687 l2tp_tunnel_put(tunnel); 688 return ERR_PTR(-ENOENT); 689 } 690 } 691 692 return tunnel; 693 } 694 695 /* connect() handler. Attach a PPPoX socket to a tunnel UDP socket 696 */ 697 static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr, 698 int sockaddr_len, int flags) 699 { 700 struct sock *sk = sock->sk; 701 struct pppox_sock *po = pppox_sk(sk); 702 struct l2tp_session *session = NULL; 703 struct l2tp_connect_info info; 704 struct l2tp_tunnel *tunnel; 705 struct pppol2tp_session *ps; 706 struct l2tp_session_cfg cfg = { 0, }; 707 bool drop_refcnt = false; 708 bool new_session = false; 709 bool new_tunnel = false; 710 int error; 711 712 error = pppol2tp_sockaddr_get_info(uservaddr, sockaddr_len, &info); 713 if (error < 0) 714 return error; 715 716 /* Don't bind if tunnel_id is 0 */ 717 if (!info.tunnel_id) 718 return -EINVAL; 719 720 tunnel = pppol2tp_tunnel_get(sock_net(sk), &info, &new_tunnel); 721 if (IS_ERR(tunnel)) 722 return PTR_ERR(tunnel); 723 724 lock_sock(sk); 725 726 /* Check for already bound sockets */ 727 error = -EBUSY; 728 if (sk->sk_state & PPPOX_CONNECTED) 729 goto end; 730 731 /* We don't supporting rebinding anyway */ 732 error = -EALREADY; 733 if (sk->sk_user_data) 734 goto end; /* socket is already attached */ 735 736 if (tunnel->peer_tunnel_id == 0) 737 tunnel->peer_tunnel_id = info.peer_tunnel_id; 738 739 session = l2tp_session_get(sock_net(sk), tunnel->sock, tunnel->version, 740 info.tunnel_id, info.session_id); 741 if (session) { 742 drop_refcnt = true; 743 744 if (session->pwtype != L2TP_PWTYPE_PPP) { 745 error = -EPROTOTYPE; 746 goto end; 747 } 748 749 ps = l2tp_session_priv(session); 750 751 /* Using a pre-existing session is fine as long as it hasn't 752 * been connected yet. 753 */ 754 mutex_lock(&ps->sk_lock); 755 if (rcu_dereference_protected(ps->sk, 756 lockdep_is_held(&ps->sk_lock)) || 757 ps->__sk) { 758 mutex_unlock(&ps->sk_lock); 759 error = -EEXIST; 760 goto end; 761 } 762 } else { 763 cfg.pw_type = L2TP_PWTYPE_PPP; 764 765 session = l2tp_session_create(sizeof(struct pppol2tp_session), 766 tunnel, info.session_id, 767 info.peer_session_id, &cfg); 768 if (IS_ERR(session)) { 769 error = PTR_ERR(session); 770 goto end; 771 } 772 773 drop_refcnt = true; 774 775 pppol2tp_session_init(session); 776 ps = l2tp_session_priv(session); 777 refcount_inc(&session->ref_count); 778 779 mutex_lock(&ps->sk_lock); 780 error = l2tp_session_register(session, tunnel); 781 if (error < 0) { 782 mutex_unlock(&ps->sk_lock); 783 l2tp_session_put(session); 784 goto end; 785 } 786 787 new_session = true; 788 } 789 790 /* Special case: if source & dest session_id == 0x0000, this 791 * socket is being created to manage the tunnel. Just set up 792 * the internal context for use by ioctl() and sockopt() 793 * handlers. 794 */ 795 if (session->session_id == 0 && session->peer_session_id == 0) { 796 error = 0; 797 goto out_no_ppp; 798 } 799 800 /* The only header we need to worry about is the L2TP 801 * header. This size is different depending on whether 802 * sequence numbers are enabled for the data channel. 803 */ 804 po->chan.hdrlen = PPPOL2TP_L2TP_HDR_SIZE_NOSEQ; 805 806 po->chan.private = sk; 807 po->chan.ops = &pppol2tp_chan_ops; 808 po->chan.mtu = pppol2tp_tunnel_mtu(tunnel); 809 810 error = ppp_register_net_channel(sock_net(sk), &po->chan); 811 if (error) { 812 mutex_unlock(&ps->sk_lock); 813 goto end; 814 } 815 816 out_no_ppp: 817 /* This is how we get the session context from the socket. */ 818 sock_hold(sk); 819 rcu_assign_sk_user_data(sk, session); 820 rcu_assign_pointer(ps->sk, sk); 821 mutex_unlock(&ps->sk_lock); 822 823 /* Keep the reference we've grabbed on the session: sk doesn't expect 824 * the session to disappear. pppol2tp_session_close() is responsible 825 * for dropping it. 826 */ 827 drop_refcnt = false; 828 829 sk->sk_state = PPPOX_CONNECTED; 830 831 end: 832 if (error) { 833 if (new_session) 834 l2tp_session_delete(session); 835 if (new_tunnel) 836 l2tp_tunnel_delete(tunnel); 837 } 838 if (drop_refcnt) 839 l2tp_session_put(session); 840 l2tp_tunnel_put(tunnel); 841 release_sock(sk); 842 843 return error; 844 } 845 846 #ifdef CONFIG_L2TP_V3 847 848 /* Called when creating sessions via the netlink interface. */ 849 static int pppol2tp_session_create(struct net *net, struct l2tp_tunnel *tunnel, 850 u32 session_id, u32 peer_session_id, 851 struct l2tp_session_cfg *cfg) 852 { 853 int error; 854 struct l2tp_session *session; 855 856 /* Error if tunnel socket is not prepped */ 857 if (!tunnel->sock) { 858 error = -ENOENT; 859 goto err; 860 } 861 862 /* Allocate and initialize a new session context. */ 863 session = l2tp_session_create(sizeof(struct pppol2tp_session), 864 tunnel, session_id, 865 peer_session_id, cfg); 866 if (IS_ERR(session)) { 867 error = PTR_ERR(session); 868 goto err; 869 } 870 871 pppol2tp_session_init(session); 872 873 error = l2tp_session_register(session, tunnel); 874 if (error < 0) 875 goto err_sess; 876 877 return 0; 878 879 err_sess: 880 l2tp_session_put(session); 881 err: 882 return error; 883 } 884 885 #endif /* CONFIG_L2TP_V3 */ 886 887 /* getname() support. 888 */ 889 static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr, 890 int peer) 891 { 892 int len = 0; 893 int error = 0; 894 struct l2tp_session *session; 895 struct l2tp_tunnel *tunnel; 896 struct sock *sk = sock->sk; 897 struct inet_sock *inet; 898 struct pppol2tp_session *pls; 899 900 error = -ENOTCONN; 901 if (!sk) 902 goto end; 903 if (!(sk->sk_state & PPPOX_CONNECTED)) 904 goto end; 905 906 error = -EBADF; 907 session = pppol2tp_sock_to_session(sk); 908 if (!session) 909 goto end; 910 911 pls = l2tp_session_priv(session); 912 tunnel = session->tunnel; 913 914 inet = inet_sk(tunnel->sock); 915 if (tunnel->version == 2 && tunnel->sock->sk_family == AF_INET) { 916 struct sockaddr_pppol2tp sp; 917 918 len = sizeof(sp); 919 memset(&sp, 0, len); 920 sp.sa_family = AF_PPPOX; 921 sp.sa_protocol = PX_PROTO_OL2TP; 922 sp.pppol2tp.fd = tunnel->fd; 923 sp.pppol2tp.pid = pls->owner; 924 sp.pppol2tp.s_tunnel = tunnel->tunnel_id; 925 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id; 926 sp.pppol2tp.s_session = session->session_id; 927 sp.pppol2tp.d_session = session->peer_session_id; 928 sp.pppol2tp.addr.sin_family = AF_INET; 929 sp.pppol2tp.addr.sin_port = inet->inet_dport; 930 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr; 931 memcpy(uaddr, &sp, len); 932 #if IS_ENABLED(CONFIG_IPV6) 933 } else if (tunnel->version == 2 && tunnel->sock->sk_family == AF_INET6) { 934 struct sockaddr_pppol2tpin6 sp; 935 936 len = sizeof(sp); 937 memset(&sp, 0, len); 938 sp.sa_family = AF_PPPOX; 939 sp.sa_protocol = PX_PROTO_OL2TP; 940 sp.pppol2tp.fd = tunnel->fd; 941 sp.pppol2tp.pid = pls->owner; 942 sp.pppol2tp.s_tunnel = tunnel->tunnel_id; 943 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id; 944 sp.pppol2tp.s_session = session->session_id; 945 sp.pppol2tp.d_session = session->peer_session_id; 946 sp.pppol2tp.addr.sin6_family = AF_INET6; 947 sp.pppol2tp.addr.sin6_port = inet->inet_dport; 948 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr, 949 sizeof(tunnel->sock->sk_v6_daddr)); 950 memcpy(uaddr, &sp, len); 951 } else if (tunnel->version == 3 && tunnel->sock->sk_family == AF_INET6) { 952 struct sockaddr_pppol2tpv3in6 sp; 953 954 len = sizeof(sp); 955 memset(&sp, 0, len); 956 sp.sa_family = AF_PPPOX; 957 sp.sa_protocol = PX_PROTO_OL2TP; 958 sp.pppol2tp.fd = tunnel->fd; 959 sp.pppol2tp.pid = pls->owner; 960 sp.pppol2tp.s_tunnel = tunnel->tunnel_id; 961 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id; 962 sp.pppol2tp.s_session = session->session_id; 963 sp.pppol2tp.d_session = session->peer_session_id; 964 sp.pppol2tp.addr.sin6_family = AF_INET6; 965 sp.pppol2tp.addr.sin6_port = inet->inet_dport; 966 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr, 967 sizeof(tunnel->sock->sk_v6_daddr)); 968 memcpy(uaddr, &sp, len); 969 #endif 970 } else if (tunnel->version == 3) { 971 struct sockaddr_pppol2tpv3 sp; 972 973 len = sizeof(sp); 974 memset(&sp, 0, len); 975 sp.sa_family = AF_PPPOX; 976 sp.sa_protocol = PX_PROTO_OL2TP; 977 sp.pppol2tp.fd = tunnel->fd; 978 sp.pppol2tp.pid = pls->owner; 979 sp.pppol2tp.s_tunnel = tunnel->tunnel_id; 980 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id; 981 sp.pppol2tp.s_session = session->session_id; 982 sp.pppol2tp.d_session = session->peer_session_id; 983 sp.pppol2tp.addr.sin_family = AF_INET; 984 sp.pppol2tp.addr.sin_port = inet->inet_dport; 985 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr; 986 memcpy(uaddr, &sp, len); 987 } 988 989 error = len; 990 991 l2tp_session_put(session); 992 end: 993 return error; 994 } 995 996 /**************************************************************************** 997 * ioctl() handlers. 998 * 999 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP 1000 * sockets. However, in order to control kernel tunnel features, we allow 1001 * userspace to create a special "tunnel" PPPoX socket which is used for 1002 * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow 1003 * the user application to issue L2TP setsockopt(), getsockopt() and ioctl() 1004 * calls. 1005 ****************************************************************************/ 1006 1007 static void pppol2tp_copy_stats(struct pppol2tp_ioc_stats *dest, 1008 const struct l2tp_stats *stats) 1009 { 1010 memset(dest, 0, sizeof(*dest)); 1011 1012 dest->tx_packets = atomic_long_read(&stats->tx_packets); 1013 dest->tx_bytes = atomic_long_read(&stats->tx_bytes); 1014 dest->tx_errors = atomic_long_read(&stats->tx_errors); 1015 dest->rx_packets = atomic_long_read(&stats->rx_packets); 1016 dest->rx_bytes = atomic_long_read(&stats->rx_bytes); 1017 dest->rx_seq_discards = atomic_long_read(&stats->rx_seq_discards); 1018 dest->rx_oos_packets = atomic_long_read(&stats->rx_oos_packets); 1019 dest->rx_errors = atomic_long_read(&stats->rx_errors); 1020 } 1021 1022 static int pppol2tp_tunnel_copy_stats(struct pppol2tp_ioc_stats *stats, 1023 struct l2tp_tunnel *tunnel) 1024 { 1025 struct l2tp_session *session; 1026 1027 if (!stats->session_id) { 1028 pppol2tp_copy_stats(stats, &tunnel->stats); 1029 return 0; 1030 } 1031 1032 /* If session_id is set, search the corresponding session in the 1033 * context of this tunnel and record the session's statistics. 1034 */ 1035 session = l2tp_session_get(tunnel->l2tp_net, tunnel->sock, tunnel->version, 1036 tunnel->tunnel_id, stats->session_id); 1037 if (!session) 1038 return -EBADR; 1039 1040 if (session->pwtype != L2TP_PWTYPE_PPP) { 1041 l2tp_session_put(session); 1042 return -EBADR; 1043 } 1044 1045 pppol2tp_copy_stats(stats, &session->stats); 1046 l2tp_session_put(session); 1047 1048 return 0; 1049 } 1050 1051 static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd, 1052 unsigned long arg) 1053 { 1054 struct pppol2tp_ioc_stats stats; 1055 struct l2tp_session *session; 1056 1057 switch (cmd) { 1058 case PPPIOCGMRU: 1059 case PPPIOCGFLAGS: 1060 session = sock->sk->sk_user_data; 1061 if (!session) 1062 return -ENOTCONN; 1063 1064 if (WARN_ON(session->magic != L2TP_SESSION_MAGIC)) 1065 return -EBADF; 1066 1067 /* Not defined for tunnels */ 1068 if (!session->session_id && !session->peer_session_id) 1069 return -ENOSYS; 1070 1071 if (put_user(0, (int __user *)arg)) 1072 return -EFAULT; 1073 break; 1074 1075 case PPPIOCSMRU: 1076 case PPPIOCSFLAGS: 1077 session = sock->sk->sk_user_data; 1078 if (!session) 1079 return -ENOTCONN; 1080 1081 if (WARN_ON(session->magic != L2TP_SESSION_MAGIC)) 1082 return -EBADF; 1083 1084 /* Not defined for tunnels */ 1085 if (!session->session_id && !session->peer_session_id) 1086 return -ENOSYS; 1087 1088 if (!access_ok((int __user *)arg, sizeof(int))) 1089 return -EFAULT; 1090 break; 1091 1092 case PPPIOCGL2TPSTATS: 1093 session = sock->sk->sk_user_data; 1094 if (!session) 1095 return -ENOTCONN; 1096 1097 if (WARN_ON(session->magic != L2TP_SESSION_MAGIC)) 1098 return -EBADF; 1099 1100 /* Session 0 represents the parent tunnel */ 1101 if (!session->session_id && !session->peer_session_id) { 1102 u32 session_id; 1103 int err; 1104 1105 if (copy_from_user(&stats, (void __user *)arg, 1106 sizeof(stats))) 1107 return -EFAULT; 1108 1109 session_id = stats.session_id; 1110 err = pppol2tp_tunnel_copy_stats(&stats, 1111 session->tunnel); 1112 if (err < 0) 1113 return err; 1114 1115 stats.session_id = session_id; 1116 } else { 1117 pppol2tp_copy_stats(&stats, &session->stats); 1118 stats.session_id = session->session_id; 1119 } 1120 stats.tunnel_id = session->tunnel->tunnel_id; 1121 stats.using_ipsec = l2tp_tunnel_uses_xfrm(session->tunnel); 1122 1123 if (copy_to_user((void __user *)arg, &stats, sizeof(stats))) 1124 return -EFAULT; 1125 break; 1126 1127 default: 1128 return -ENOIOCTLCMD; 1129 } 1130 1131 return 0; 1132 } 1133 1134 /***************************************************************************** 1135 * setsockopt() / getsockopt() support. 1136 * 1137 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP 1138 * sockets. In order to control kernel tunnel features, we allow userspace to 1139 * create a special "tunnel" PPPoX socket which is used for control only. 1140 * Tunnel PPPoX sockets have session_id == 0 and simply allow the user 1141 * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls. 1142 *****************************************************************************/ 1143 1144 /* Tunnel setsockopt() helper. 1145 */ 1146 static int pppol2tp_tunnel_setsockopt(struct sock *sk, 1147 struct l2tp_tunnel *tunnel, 1148 int optname, int val) 1149 { 1150 int err = 0; 1151 1152 switch (optname) { 1153 case PPPOL2TP_SO_DEBUG: 1154 /* Tunnel debug flags option is deprecated */ 1155 break; 1156 1157 default: 1158 err = -ENOPROTOOPT; 1159 break; 1160 } 1161 1162 return err; 1163 } 1164 1165 /* Session setsockopt helper. 1166 */ 1167 static int pppol2tp_session_setsockopt(struct sock *sk, 1168 struct l2tp_session *session, 1169 int optname, int val) 1170 { 1171 int err = 0; 1172 1173 switch (optname) { 1174 case PPPOL2TP_SO_RECVSEQ: 1175 if (val != 0 && val != 1) { 1176 err = -EINVAL; 1177 break; 1178 } 1179 session->recv_seq = !!val; 1180 break; 1181 1182 case PPPOL2TP_SO_SENDSEQ: 1183 if (val != 0 && val != 1) { 1184 err = -EINVAL; 1185 break; 1186 } 1187 session->send_seq = !!val; 1188 { 1189 struct pppox_sock *po = pppox_sk(sk); 1190 1191 po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ : 1192 PPPOL2TP_L2TP_HDR_SIZE_NOSEQ; 1193 } 1194 l2tp_session_set_header_len(session, session->tunnel->version, 1195 session->tunnel->encap); 1196 break; 1197 1198 case PPPOL2TP_SO_LNSMODE: 1199 if (val != 0 && val != 1) { 1200 err = -EINVAL; 1201 break; 1202 } 1203 session->lns_mode = !!val; 1204 break; 1205 1206 case PPPOL2TP_SO_DEBUG: 1207 /* Session debug flags option is deprecated */ 1208 break; 1209 1210 case PPPOL2TP_SO_REORDERTO: 1211 session->reorder_timeout = msecs_to_jiffies(val); 1212 break; 1213 1214 default: 1215 err = -ENOPROTOOPT; 1216 break; 1217 } 1218 1219 return err; 1220 } 1221 1222 /* Main setsockopt() entry point. 1223 * Does API checks, then calls either the tunnel or session setsockopt 1224 * handler, according to whether the PPPoL2TP socket is a for a regular 1225 * session or the special tunnel type. 1226 */ 1227 static int pppol2tp_setsockopt(struct socket *sock, int level, int optname, 1228 sockptr_t optval, unsigned int optlen) 1229 { 1230 struct sock *sk = sock->sk; 1231 struct l2tp_session *session; 1232 struct l2tp_tunnel *tunnel; 1233 int val; 1234 int err; 1235 1236 if (level != SOL_PPPOL2TP) 1237 return -EINVAL; 1238 1239 if (optlen < sizeof(int)) 1240 return -EINVAL; 1241 1242 if (copy_from_sockptr(&val, optval, sizeof(int))) 1243 return -EFAULT; 1244 1245 err = -ENOTCONN; 1246 if (!sk->sk_user_data) 1247 goto end; 1248 1249 /* Get session context from the socket */ 1250 err = -EBADF; 1251 session = pppol2tp_sock_to_session(sk); 1252 if (!session) 1253 goto end; 1254 1255 /* Special case: if session_id == 0x0000, treat as operation on tunnel 1256 */ 1257 if (session->session_id == 0 && session->peer_session_id == 0) { 1258 tunnel = session->tunnel; 1259 err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val); 1260 } else { 1261 err = pppol2tp_session_setsockopt(sk, session, optname, val); 1262 } 1263 1264 l2tp_session_put(session); 1265 end: 1266 return err; 1267 } 1268 1269 /* Tunnel getsockopt helper. Called with sock locked. 1270 */ 1271 static int pppol2tp_tunnel_getsockopt(struct sock *sk, 1272 struct l2tp_tunnel *tunnel, 1273 int optname, int *val) 1274 { 1275 int err = 0; 1276 1277 switch (optname) { 1278 case PPPOL2TP_SO_DEBUG: 1279 /* Tunnel debug flags option is deprecated */ 1280 *val = 0; 1281 break; 1282 1283 default: 1284 err = -ENOPROTOOPT; 1285 break; 1286 } 1287 1288 return err; 1289 } 1290 1291 /* Session getsockopt helper. Called with sock locked. 1292 */ 1293 static int pppol2tp_session_getsockopt(struct sock *sk, 1294 struct l2tp_session *session, 1295 int optname, int *val) 1296 { 1297 int err = 0; 1298 1299 switch (optname) { 1300 case PPPOL2TP_SO_RECVSEQ: 1301 *val = session->recv_seq; 1302 break; 1303 1304 case PPPOL2TP_SO_SENDSEQ: 1305 *val = session->send_seq; 1306 break; 1307 1308 case PPPOL2TP_SO_LNSMODE: 1309 *val = session->lns_mode; 1310 break; 1311 1312 case PPPOL2TP_SO_DEBUG: 1313 /* Session debug flags option is deprecated */ 1314 *val = 0; 1315 break; 1316 1317 case PPPOL2TP_SO_REORDERTO: 1318 *val = (int)jiffies_to_msecs(session->reorder_timeout); 1319 break; 1320 1321 default: 1322 err = -ENOPROTOOPT; 1323 } 1324 1325 return err; 1326 } 1327 1328 /* Main getsockopt() entry point. 1329 * Does API checks, then calls either the tunnel or session getsockopt 1330 * handler, according to whether the PPPoX socket is a for a regular session 1331 * or the special tunnel type. 1332 */ 1333 static int pppol2tp_getsockopt(struct socket *sock, int level, int optname, 1334 char __user *optval, int __user *optlen) 1335 { 1336 struct sock *sk = sock->sk; 1337 struct l2tp_session *session; 1338 struct l2tp_tunnel *tunnel; 1339 int val, len; 1340 int err; 1341 1342 if (level != SOL_PPPOL2TP) 1343 return -EINVAL; 1344 1345 if (get_user(len, optlen)) 1346 return -EFAULT; 1347 1348 if (len < 0) 1349 return -EINVAL; 1350 1351 len = min_t(unsigned int, len, sizeof(int)); 1352 1353 err = -ENOTCONN; 1354 if (!sk->sk_user_data) 1355 goto end; 1356 1357 /* Get the session context */ 1358 err = -EBADF; 1359 session = pppol2tp_sock_to_session(sk); 1360 if (!session) 1361 goto end; 1362 1363 /* Special case: if session_id == 0x0000, treat as operation on tunnel */ 1364 if (session->session_id == 0 && session->peer_session_id == 0) { 1365 tunnel = session->tunnel; 1366 err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val); 1367 if (err) 1368 goto end_put_sess; 1369 } else { 1370 err = pppol2tp_session_getsockopt(sk, session, optname, &val); 1371 if (err) 1372 goto end_put_sess; 1373 } 1374 1375 err = -EFAULT; 1376 if (put_user(len, optlen)) 1377 goto end_put_sess; 1378 1379 if (copy_to_user((void __user *)optval, &val, len)) 1380 goto end_put_sess; 1381 1382 err = 0; 1383 1384 end_put_sess: 1385 l2tp_session_put(session); 1386 end: 1387 return err; 1388 } 1389 1390 /***************************************************************************** 1391 * /proc filesystem for debug 1392 * Since the original pppol2tp driver provided /proc/net/pppol2tp for 1393 * L2TPv2, we dump only L2TPv2 tunnels and sessions here. 1394 *****************************************************************************/ 1395 1396 #ifdef CONFIG_PROC_FS 1397 1398 struct pppol2tp_seq_data { 1399 struct seq_net_private p; 1400 unsigned long tkey; /* lookup key of current tunnel */ 1401 unsigned long skey; /* lookup key of current session */ 1402 struct l2tp_tunnel *tunnel; 1403 struct l2tp_session *session; /* NULL means get next tunnel */ 1404 }; 1405 1406 static void pppol2tp_next_tunnel(struct net *net, struct pppol2tp_seq_data *pd) 1407 { 1408 /* Drop reference taken during previous invocation */ 1409 if (pd->tunnel) 1410 l2tp_tunnel_put(pd->tunnel); 1411 1412 for (;;) { 1413 pd->tunnel = l2tp_tunnel_get_next(net, &pd->tkey); 1414 pd->tkey++; 1415 1416 /* Only accept L2TPv2 tunnels */ 1417 if (!pd->tunnel || pd->tunnel->version == 2) 1418 return; 1419 1420 l2tp_tunnel_put(pd->tunnel); 1421 } 1422 } 1423 1424 static void pppol2tp_next_session(struct net *net, struct pppol2tp_seq_data *pd) 1425 { 1426 /* Drop reference taken during previous invocation */ 1427 if (pd->session) 1428 l2tp_session_put(pd->session); 1429 1430 pd->session = l2tp_session_get_next(net, pd->tunnel->sock, 1431 pd->tunnel->version, 1432 pd->tunnel->tunnel_id, &pd->skey); 1433 pd->skey++; 1434 1435 if (!pd->session) { 1436 pd->skey = 0; 1437 pppol2tp_next_tunnel(net, pd); 1438 } 1439 } 1440 1441 static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs) 1442 { 1443 struct pppol2tp_seq_data *pd = SEQ_START_TOKEN; 1444 loff_t pos = *offs; 1445 struct net *net; 1446 1447 if (!pos) 1448 goto out; 1449 1450 if (WARN_ON(!m->private)) { 1451 pd = NULL; 1452 goto out; 1453 } 1454 1455 pd = m->private; 1456 net = seq_file_net(m); 1457 1458 if (!pd->tunnel) 1459 pppol2tp_next_tunnel(net, pd); 1460 else 1461 pppol2tp_next_session(net, pd); 1462 1463 /* NULL tunnel and session indicates end of list */ 1464 if (!pd->tunnel && !pd->session) 1465 pd = NULL; 1466 1467 out: 1468 return pd; 1469 } 1470 1471 static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos) 1472 { 1473 (*pos)++; 1474 return NULL; 1475 } 1476 1477 static void pppol2tp_seq_stop(struct seq_file *p, void *v) 1478 { 1479 struct pppol2tp_seq_data *pd = v; 1480 1481 if (!pd || pd == SEQ_START_TOKEN) 1482 return; 1483 1484 /* Drop reference taken by last invocation of pppol2tp_next_session() 1485 * or pppol2tp_next_tunnel(). 1486 */ 1487 if (pd->session) { 1488 l2tp_session_put(pd->session); 1489 pd->session = NULL; 1490 } 1491 if (pd->tunnel) { 1492 l2tp_tunnel_put(pd->tunnel); 1493 pd->tunnel = NULL; 1494 } 1495 } 1496 1497 static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v) 1498 { 1499 struct l2tp_tunnel *tunnel = v; 1500 1501 seq_printf(m, "\nTUNNEL '%s', %c %d\n", 1502 tunnel->name, 1503 tunnel->sock ? 'Y' : 'N', 1504 refcount_read(&tunnel->ref_count) - 1); 1505 seq_printf(m, " %08x %ld/%ld/%ld %ld/%ld/%ld\n", 1506 0, 1507 atomic_long_read(&tunnel->stats.tx_packets), 1508 atomic_long_read(&tunnel->stats.tx_bytes), 1509 atomic_long_read(&tunnel->stats.tx_errors), 1510 atomic_long_read(&tunnel->stats.rx_packets), 1511 atomic_long_read(&tunnel->stats.rx_bytes), 1512 atomic_long_read(&tunnel->stats.rx_errors)); 1513 } 1514 1515 static void pppol2tp_seq_session_show(struct seq_file *m, void *v) 1516 { 1517 struct l2tp_session *session = v; 1518 struct l2tp_tunnel *tunnel = session->tunnel; 1519 unsigned char state; 1520 char user_data_ok; 1521 struct sock *sk; 1522 u32 ip = 0; 1523 u16 port = 0; 1524 1525 if (tunnel->sock) { 1526 struct inet_sock *inet = inet_sk(tunnel->sock); 1527 1528 ip = ntohl(inet->inet_saddr); 1529 port = ntohs(inet->inet_sport); 1530 } 1531 1532 sk = pppol2tp_session_get_sock(session); 1533 if (sk) { 1534 state = sk->sk_state; 1535 user_data_ok = (session == sk->sk_user_data) ? 'Y' : 'N'; 1536 } else { 1537 state = 0; 1538 user_data_ok = 'N'; 1539 } 1540 1541 seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> %04X/%04X %d %c\n", 1542 session->name, ip, port, 1543 tunnel->tunnel_id, 1544 session->session_id, 1545 tunnel->peer_tunnel_id, 1546 session->peer_session_id, 1547 state, user_data_ok); 1548 seq_printf(m, " 0/0/%c/%c/%s %08x %u\n", 1549 session->recv_seq ? 'R' : '-', 1550 session->send_seq ? 'S' : '-', 1551 session->lns_mode ? "LNS" : "LAC", 1552 0, 1553 jiffies_to_msecs(session->reorder_timeout)); 1554 seq_printf(m, " %u/%u %ld/%ld/%ld %ld/%ld/%ld\n", 1555 session->nr, session->ns, 1556 atomic_long_read(&session->stats.tx_packets), 1557 atomic_long_read(&session->stats.tx_bytes), 1558 atomic_long_read(&session->stats.tx_errors), 1559 atomic_long_read(&session->stats.rx_packets), 1560 atomic_long_read(&session->stats.rx_bytes), 1561 atomic_long_read(&session->stats.rx_errors)); 1562 1563 if (sk) { 1564 struct pppox_sock *po = pppox_sk(sk); 1565 1566 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan)); 1567 sock_put(sk); 1568 } 1569 } 1570 1571 static int pppol2tp_seq_show(struct seq_file *m, void *v) 1572 { 1573 struct pppol2tp_seq_data *pd = v; 1574 1575 /* display header on line 1 */ 1576 if (v == SEQ_START_TOKEN) { 1577 seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n"); 1578 seq_puts(m, "TUNNEL name, user-data-ok session-count\n"); 1579 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); 1580 seq_puts(m, " SESSION name, addr/port src-tid/sid dest-tid/sid state user-data-ok\n"); 1581 seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n"); 1582 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); 1583 goto out; 1584 } 1585 1586 if (!pd->session) 1587 pppol2tp_seq_tunnel_show(m, pd->tunnel); 1588 else 1589 pppol2tp_seq_session_show(m, pd->session); 1590 1591 out: 1592 return 0; 1593 } 1594 1595 static const struct seq_operations pppol2tp_seq_ops = { 1596 .start = pppol2tp_seq_start, 1597 .next = pppol2tp_seq_next, 1598 .stop = pppol2tp_seq_stop, 1599 .show = pppol2tp_seq_show, 1600 }; 1601 #endif /* CONFIG_PROC_FS */ 1602 1603 /***************************************************************************** 1604 * Network namespace 1605 *****************************************************************************/ 1606 1607 static __net_init int pppol2tp_init_net(struct net *net) 1608 { 1609 struct proc_dir_entry *pde; 1610 int err = 0; 1611 1612 pde = proc_create_net("pppol2tp", 0444, net->proc_net, 1613 &pppol2tp_seq_ops, sizeof(struct pppol2tp_seq_data)); 1614 if (!pde) { 1615 err = -ENOMEM; 1616 goto out; 1617 } 1618 1619 out: 1620 return err; 1621 } 1622 1623 static __net_exit void pppol2tp_exit_net(struct net *net) 1624 { 1625 remove_proc_entry("pppol2tp", net->proc_net); 1626 } 1627 1628 static struct pernet_operations pppol2tp_net_ops = { 1629 .init = pppol2tp_init_net, 1630 .exit = pppol2tp_exit_net, 1631 }; 1632 1633 /***************************************************************************** 1634 * Init and cleanup 1635 *****************************************************************************/ 1636 1637 static const struct proto_ops pppol2tp_ops = { 1638 .family = AF_PPPOX, 1639 .owner = THIS_MODULE, 1640 .release = pppol2tp_release, 1641 .bind = sock_no_bind, 1642 .connect = pppol2tp_connect, 1643 .socketpair = sock_no_socketpair, 1644 .accept = sock_no_accept, 1645 .getname = pppol2tp_getname, 1646 .poll = datagram_poll, 1647 .listen = sock_no_listen, 1648 .shutdown = sock_no_shutdown, 1649 .setsockopt = pppol2tp_setsockopt, 1650 .getsockopt = pppol2tp_getsockopt, 1651 .sendmsg = pppol2tp_sendmsg, 1652 .recvmsg = pppol2tp_recvmsg, 1653 .mmap = sock_no_mmap, 1654 .ioctl = pppox_ioctl, 1655 #ifdef CONFIG_COMPAT 1656 .compat_ioctl = pppox_compat_ioctl, 1657 #endif 1658 }; 1659 1660 static const struct pppox_proto pppol2tp_proto = { 1661 .create = pppol2tp_create, 1662 .ioctl = pppol2tp_ioctl, 1663 .owner = THIS_MODULE, 1664 }; 1665 1666 #ifdef CONFIG_L2TP_V3 1667 1668 static const struct l2tp_nl_cmd_ops pppol2tp_nl_cmd_ops = { 1669 .session_create = pppol2tp_session_create, 1670 .session_delete = l2tp_session_delete, 1671 }; 1672 1673 #endif /* CONFIG_L2TP_V3 */ 1674 1675 static int __init pppol2tp_init(void) 1676 { 1677 int err; 1678 1679 err = register_pernet_device(&pppol2tp_net_ops); 1680 if (err) 1681 goto out; 1682 1683 err = proto_register(&pppol2tp_sk_proto, 0); 1684 if (err) 1685 goto out_unregister_pppol2tp_pernet; 1686 1687 err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto); 1688 if (err) 1689 goto out_unregister_pppol2tp_proto; 1690 1691 #ifdef CONFIG_L2TP_V3 1692 err = l2tp_nl_register_ops(L2TP_PWTYPE_PPP, &pppol2tp_nl_cmd_ops); 1693 if (err) 1694 goto out_unregister_pppox; 1695 #endif 1696 1697 pr_info("PPPoL2TP kernel driver, %s\n", PPPOL2TP_DRV_VERSION); 1698 1699 out: 1700 return err; 1701 1702 #ifdef CONFIG_L2TP_V3 1703 out_unregister_pppox: 1704 unregister_pppox_proto(PX_PROTO_OL2TP); 1705 #endif 1706 out_unregister_pppol2tp_proto: 1707 proto_unregister(&pppol2tp_sk_proto); 1708 out_unregister_pppol2tp_pernet: 1709 unregister_pernet_device(&pppol2tp_net_ops); 1710 goto out; 1711 } 1712 1713 static void __exit pppol2tp_exit(void) 1714 { 1715 #ifdef CONFIG_L2TP_V3 1716 l2tp_nl_unregister_ops(L2TP_PWTYPE_PPP); 1717 #endif 1718 unregister_pppox_proto(PX_PROTO_OL2TP); 1719 proto_unregister(&pppol2tp_sk_proto); 1720 unregister_pernet_device(&pppol2tp_net_ops); 1721 } 1722 1723 module_init(pppol2tp_init); 1724 module_exit(pppol2tp_exit); 1725 1726 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); 1727 MODULE_DESCRIPTION("PPP over L2TP over UDP"); 1728 MODULE_LICENSE("GPL"); 1729 MODULE_VERSION(PPPOL2TP_DRV_VERSION); 1730 MODULE_ALIAS_NET_PF_PROTO(PF_PPPOX, PX_PROTO_OL2TP); 1731 MODULE_ALIAS_L2TP_PWTYPE(7); 1732