1 /***************************************************************************** 2 * Linux PPP over L2TP (PPPoX/PPPoL2TP) Sockets 3 * 4 * PPPoX --- Generic PPP encapsulation socket family 5 * PPPoL2TP --- PPP over L2TP (RFC 2661) 6 * 7 * Version: 2.0.0 8 * 9 * Authors: James Chapman (jchapman@katalix.com) 10 * 11 * Based on original work by Martijn van Oosterhout <kleptog@svana.org> 12 * 13 * License: 14 * This program is free software; you can redistribute it and/or 15 * modify it under the terms of the GNU General Public License 16 * as published by the Free Software Foundation; either version 17 * 2 of the License, or (at your option) any later version. 18 * 19 */ 20 21 /* This driver handles only L2TP data frames; control frames are handled by a 22 * userspace application. 23 * 24 * To send data in an L2TP session, userspace opens a PPPoL2TP socket and 25 * attaches it to a bound UDP socket with local tunnel_id / session_id and 26 * peer tunnel_id / session_id set. Data can then be sent or received using 27 * regular socket sendmsg() / recvmsg() calls. Kernel parameters of the socket 28 * can be read or modified using ioctl() or [gs]etsockopt() calls. 29 * 30 * When a PPPoL2TP socket is connected with local and peer session_id values 31 * zero, the socket is treated as a special tunnel management socket. 32 * 33 * Here's example userspace code to create a socket for sending/receiving data 34 * over an L2TP session:- 35 * 36 * struct sockaddr_pppol2tp sax; 37 * int fd; 38 * int session_fd; 39 * 40 * fd = socket(AF_PPPOX, SOCK_DGRAM, PX_PROTO_OL2TP); 41 * 42 * sax.sa_family = AF_PPPOX; 43 * sax.sa_protocol = PX_PROTO_OL2TP; 44 * sax.pppol2tp.fd = tunnel_fd; // bound UDP socket 45 * sax.pppol2tp.addr.sin_addr.s_addr = addr->sin_addr.s_addr; 46 * sax.pppol2tp.addr.sin_port = addr->sin_port; 47 * sax.pppol2tp.addr.sin_family = AF_INET; 48 * sax.pppol2tp.s_tunnel = tunnel_id; 49 * sax.pppol2tp.s_session = session_id; 50 * sax.pppol2tp.d_tunnel = peer_tunnel_id; 51 * sax.pppol2tp.d_session = peer_session_id; 52 * 53 * session_fd = connect(fd, (struct sockaddr *)&sax, sizeof(sax)); 54 * 55 * A pppd plugin that allows PPP traffic to be carried over L2TP using 56 * this driver is available from the OpenL2TP project at 57 * http://openl2tp.sourceforge.net. 58 */ 59 60 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 61 62 #include <linux/module.h> 63 #include <linux/string.h> 64 #include <linux/list.h> 65 #include <linux/uaccess.h> 66 67 #include <linux/kernel.h> 68 #include <linux/spinlock.h> 69 #include <linux/kthread.h> 70 #include <linux/sched.h> 71 #include <linux/slab.h> 72 #include <linux/errno.h> 73 #include <linux/jiffies.h> 74 75 #include <linux/netdevice.h> 76 #include <linux/net.h> 77 #include <linux/inetdevice.h> 78 #include <linux/skbuff.h> 79 #include <linux/init.h> 80 #include <linux/ip.h> 81 #include <linux/udp.h> 82 #include <linux/if_pppox.h> 83 #include <linux/if_pppol2tp.h> 84 #include <net/sock.h> 85 #include <linux/ppp_channel.h> 86 #include <linux/ppp_defs.h> 87 #include <linux/ppp-ioctl.h> 88 #include <linux/file.h> 89 #include <linux/hash.h> 90 #include <linux/sort.h> 91 #include <linux/proc_fs.h> 92 #include <linux/l2tp.h> 93 #include <linux/nsproxy.h> 94 #include <net/net_namespace.h> 95 #include <net/netns/generic.h> 96 #include <net/dst.h> 97 #include <net/ip.h> 98 #include <net/udp.h> 99 #include <net/xfrm.h> 100 #include <net/inet_common.h> 101 102 #include <asm/byteorder.h> 103 #include <linux/atomic.h> 104 105 #include "l2tp_core.h" 106 107 #define PPPOL2TP_DRV_VERSION "V2.0" 108 109 /* Space for UDP, L2TP and PPP headers */ 110 #define PPPOL2TP_HEADER_OVERHEAD 40 111 112 /* Number of bytes to build transmit L2TP headers. 113 * Unfortunately the size is different depending on whether sequence numbers 114 * are enabled. 115 */ 116 #define PPPOL2TP_L2TP_HDR_SIZE_SEQ 10 117 #define PPPOL2TP_L2TP_HDR_SIZE_NOSEQ 6 118 119 /* Private data of each session. This data lives at the end of struct 120 * l2tp_session, referenced via session->priv[]. 121 */ 122 struct pppol2tp_session { 123 int owner; /* pid that opened the socket */ 124 125 struct sock *sock; /* Pointer to the session 126 * PPPoX socket */ 127 struct sock *tunnel_sock; /* Pointer to the tunnel UDP 128 * socket */ 129 int flags; /* accessed by PPPIOCGFLAGS. 130 * Unused. */ 131 }; 132 133 static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb); 134 135 static const struct ppp_channel_ops pppol2tp_chan_ops = { 136 .start_xmit = pppol2tp_xmit, 137 }; 138 139 static const struct proto_ops pppol2tp_ops; 140 141 /* Helpers to obtain tunnel/session contexts from sockets. 142 */ 143 static inline struct l2tp_session *pppol2tp_sock_to_session(struct sock *sk) 144 { 145 struct l2tp_session *session; 146 147 if (sk == NULL) 148 return NULL; 149 150 sock_hold(sk); 151 session = (struct l2tp_session *)(sk->sk_user_data); 152 if (session == NULL) { 153 sock_put(sk); 154 goto out; 155 } 156 157 BUG_ON(session->magic != L2TP_SESSION_MAGIC); 158 159 out: 160 return session; 161 } 162 163 /***************************************************************************** 164 * Receive data handling 165 *****************************************************************************/ 166 167 static int pppol2tp_recv_payload_hook(struct sk_buff *skb) 168 { 169 /* Skip PPP header, if present. In testing, Microsoft L2TP clients 170 * don't send the PPP header (PPP header compression enabled), but 171 * other clients can include the header. So we cope with both cases 172 * here. The PPP header is always FF03 when using L2TP. 173 * 174 * Note that skb->data[] isn't dereferenced from a u16 ptr here since 175 * the field may be unaligned. 176 */ 177 if (!pskb_may_pull(skb, 2)) 178 return 1; 179 180 if ((skb->data[0] == PPP_ALLSTATIONS) && (skb->data[1] == PPP_UI)) 181 skb_pull(skb, 2); 182 183 return 0; 184 } 185 186 /* Receive message. This is the recvmsg for the PPPoL2TP socket. 187 */ 188 static int pppol2tp_recvmsg(struct socket *sock, struct msghdr *msg, 189 size_t len, int flags) 190 { 191 int err; 192 struct sk_buff *skb; 193 struct sock *sk = sock->sk; 194 195 err = -EIO; 196 if (sk->sk_state & PPPOX_BOUND) 197 goto end; 198 199 err = 0; 200 skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT, 201 flags & MSG_DONTWAIT, &err); 202 if (!skb) 203 goto end; 204 205 if (len > skb->len) 206 len = skb->len; 207 else if (len < skb->len) 208 msg->msg_flags |= MSG_TRUNC; 209 210 err = skb_copy_datagram_msg(skb, 0, msg, len); 211 if (likely(err == 0)) 212 err = len; 213 214 kfree_skb(skb); 215 end: 216 return err; 217 } 218 219 static void pppol2tp_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len) 220 { 221 struct pppol2tp_session *ps = l2tp_session_priv(session); 222 struct sock *sk = NULL; 223 224 /* If the socket is bound, send it in to PPP's input queue. Otherwise 225 * queue it on the session socket. 226 */ 227 sk = ps->sock; 228 if (sk == NULL) 229 goto no_sock; 230 231 if (sk->sk_state & PPPOX_BOUND) { 232 struct pppox_sock *po; 233 234 l2tp_dbg(session, L2TP_MSG_DATA, 235 "%s: recv %d byte data frame, passing to ppp\n", 236 session->name, data_len); 237 238 po = pppox_sk(sk); 239 ppp_input(&po->chan, skb); 240 } else { 241 l2tp_dbg(session, L2TP_MSG_DATA, 242 "%s: recv %d byte data frame, passing to L2TP socket\n", 243 session->name, data_len); 244 245 if (sock_queue_rcv_skb(sk, skb) < 0) { 246 atomic_long_inc(&session->stats.rx_errors); 247 kfree_skb(skb); 248 } 249 } 250 251 return; 252 253 no_sock: 254 l2tp_info(session, L2TP_MSG_DATA, "%s: no socket\n", session->name); 255 kfree_skb(skb); 256 } 257 258 static void pppol2tp_session_sock_hold(struct l2tp_session *session) 259 { 260 struct pppol2tp_session *ps = l2tp_session_priv(session); 261 262 if (ps->sock) 263 sock_hold(ps->sock); 264 } 265 266 static void pppol2tp_session_sock_put(struct l2tp_session *session) 267 { 268 struct pppol2tp_session *ps = l2tp_session_priv(session); 269 270 if (ps->sock) 271 sock_put(ps->sock); 272 } 273 274 /************************************************************************ 275 * Transmit handling 276 ***********************************************************************/ 277 278 /* This is the sendmsg for the PPPoL2TP pppol2tp_session socket. We come here 279 * when a user application does a sendmsg() on the session socket. L2TP and 280 * PPP headers must be inserted into the user's data. 281 */ 282 static int pppol2tp_sendmsg(struct socket *sock, struct msghdr *m, 283 size_t total_len) 284 { 285 struct sock *sk = sock->sk; 286 struct sk_buff *skb; 287 int error; 288 struct l2tp_session *session; 289 struct l2tp_tunnel *tunnel; 290 struct pppol2tp_session *ps; 291 int uhlen; 292 293 error = -ENOTCONN; 294 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) 295 goto error; 296 297 /* Get session and tunnel contexts */ 298 error = -EBADF; 299 session = pppol2tp_sock_to_session(sk); 300 if (session == NULL) 301 goto error; 302 303 ps = l2tp_session_priv(session); 304 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock); 305 if (tunnel == NULL) 306 goto error_put_sess; 307 308 uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; 309 310 /* Allocate a socket buffer */ 311 error = -ENOMEM; 312 skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) + 313 uhlen + session->hdr_len + 314 2 + total_len, /* 2 bytes for PPP_ALLSTATIONS & PPP_UI */ 315 0, GFP_KERNEL); 316 if (!skb) 317 goto error_put_sess_tun; 318 319 /* Reserve space for headers. */ 320 skb_reserve(skb, NET_SKB_PAD); 321 skb_reset_network_header(skb); 322 skb_reserve(skb, sizeof(struct iphdr)); 323 skb_reset_transport_header(skb); 324 skb_reserve(skb, uhlen); 325 326 /* Add PPP header */ 327 skb->data[0] = PPP_ALLSTATIONS; 328 skb->data[1] = PPP_UI; 329 skb_put(skb, 2); 330 331 /* Copy user data into skb */ 332 error = memcpy_from_msg(skb_put(skb, total_len), m, total_len); 333 if (error < 0) { 334 kfree_skb(skb); 335 goto error_put_sess_tun; 336 } 337 338 local_bh_disable(); 339 l2tp_xmit_skb(session, skb, session->hdr_len); 340 local_bh_enable(); 341 342 sock_put(ps->tunnel_sock); 343 sock_put(sk); 344 345 return total_len; 346 347 error_put_sess_tun: 348 sock_put(ps->tunnel_sock); 349 error_put_sess: 350 sock_put(sk); 351 error: 352 return error; 353 } 354 355 /* Transmit function called by generic PPP driver. Sends PPP frame 356 * over PPPoL2TP socket. 357 * 358 * This is almost the same as pppol2tp_sendmsg(), but rather than 359 * being called with a msghdr from userspace, it is called with a skb 360 * from the kernel. 361 * 362 * The supplied skb from ppp doesn't have enough headroom for the 363 * insertion of L2TP, UDP and IP headers so we need to allocate more 364 * headroom in the skb. This will create a cloned skb. But we must be 365 * careful in the error case because the caller will expect to free 366 * the skb it supplied, not our cloned skb. So we take care to always 367 * leave the original skb unfreed if we return an error. 368 */ 369 static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb) 370 { 371 struct sock *sk = (struct sock *) chan->private; 372 struct sock *sk_tun; 373 struct l2tp_session *session; 374 struct l2tp_tunnel *tunnel; 375 struct pppol2tp_session *ps; 376 int uhlen, headroom; 377 378 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) 379 goto abort; 380 381 /* Get session and tunnel contexts from the socket */ 382 session = pppol2tp_sock_to_session(sk); 383 if (session == NULL) 384 goto abort; 385 386 ps = l2tp_session_priv(session); 387 sk_tun = ps->tunnel_sock; 388 if (sk_tun == NULL) 389 goto abort_put_sess; 390 tunnel = l2tp_sock_to_tunnel(sk_tun); 391 if (tunnel == NULL) 392 goto abort_put_sess; 393 394 uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; 395 headroom = NET_SKB_PAD + 396 sizeof(struct iphdr) + /* IP header */ 397 uhlen + /* UDP header (if L2TP_ENCAPTYPE_UDP) */ 398 session->hdr_len + /* L2TP header */ 399 2; /* 2 bytes for PPP_ALLSTATIONS & PPP_UI */ 400 if (skb_cow_head(skb, headroom)) 401 goto abort_put_sess_tun; 402 403 /* Setup PPP header */ 404 __skb_push(skb, 2); 405 skb->data[0] = PPP_ALLSTATIONS; 406 skb->data[1] = PPP_UI; 407 408 local_bh_disable(); 409 l2tp_xmit_skb(session, skb, session->hdr_len); 410 local_bh_enable(); 411 412 sock_put(sk_tun); 413 sock_put(sk); 414 return 1; 415 416 abort_put_sess_tun: 417 sock_put(sk_tun); 418 abort_put_sess: 419 sock_put(sk); 420 abort: 421 /* Free the original skb */ 422 kfree_skb(skb); 423 return 1; 424 } 425 426 /***************************************************************************** 427 * Session (and tunnel control) socket create/destroy. 428 *****************************************************************************/ 429 430 /* Called by l2tp_core when a session socket is being closed. 431 */ 432 static void pppol2tp_session_close(struct l2tp_session *session) 433 { 434 struct pppol2tp_session *ps = l2tp_session_priv(session); 435 struct sock *sk = ps->sock; 436 struct socket *sock = sk->sk_socket; 437 438 BUG_ON(session->magic != L2TP_SESSION_MAGIC); 439 440 if (sock) { 441 inet_shutdown(sock, SEND_SHUTDOWN); 442 /* Don't let the session go away before our socket does */ 443 l2tp_session_inc_refcount(session); 444 } 445 } 446 447 /* Really kill the session socket. (Called from sock_put() if 448 * refcnt == 0.) 449 */ 450 static void pppol2tp_session_destruct(struct sock *sk) 451 { 452 struct l2tp_session *session = sk->sk_user_data; 453 454 skb_queue_purge(&sk->sk_receive_queue); 455 skb_queue_purge(&sk->sk_write_queue); 456 457 if (session) { 458 sk->sk_user_data = NULL; 459 BUG_ON(session->magic != L2TP_SESSION_MAGIC); 460 l2tp_session_dec_refcount(session); 461 } 462 } 463 464 /* Called when the PPPoX socket (session) is closed. 465 */ 466 static int pppol2tp_release(struct socket *sock) 467 { 468 struct sock *sk = sock->sk; 469 struct l2tp_session *session; 470 int error; 471 472 if (!sk) 473 return 0; 474 475 error = -EBADF; 476 lock_sock(sk); 477 if (sock_flag(sk, SOCK_DEAD) != 0) 478 goto error; 479 480 pppox_unbind_sock(sk); 481 482 /* Signal the death of the socket. */ 483 sk->sk_state = PPPOX_DEAD; 484 sock_orphan(sk); 485 sock->sk = NULL; 486 487 session = pppol2tp_sock_to_session(sk); 488 489 /* Purge any queued data */ 490 if (session != NULL) { 491 __l2tp_session_unhash(session); 492 l2tp_session_queue_purge(session); 493 sock_put(sk); 494 } 495 release_sock(sk); 496 497 /* This will delete the session context via 498 * pppol2tp_session_destruct() if the socket's refcnt drops to 499 * zero. 500 */ 501 sock_put(sk); 502 503 return 0; 504 505 error: 506 release_sock(sk); 507 return error; 508 } 509 510 static struct proto pppol2tp_sk_proto = { 511 .name = "PPPOL2TP", 512 .owner = THIS_MODULE, 513 .obj_size = sizeof(struct pppox_sock), 514 }; 515 516 static int pppol2tp_backlog_recv(struct sock *sk, struct sk_buff *skb) 517 { 518 int rc; 519 520 rc = l2tp_udp_encap_recv(sk, skb); 521 if (rc) 522 kfree_skb(skb); 523 524 return NET_RX_SUCCESS; 525 } 526 527 /* socket() handler. Initialize a new struct sock. 528 */ 529 static int pppol2tp_create(struct net *net, struct socket *sock, int kern) 530 { 531 int error = -ENOMEM; 532 struct sock *sk; 533 534 sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppol2tp_sk_proto, kern); 535 if (!sk) 536 goto out; 537 538 sock_init_data(sock, sk); 539 540 sock->state = SS_UNCONNECTED; 541 sock->ops = &pppol2tp_ops; 542 543 sk->sk_backlog_rcv = pppol2tp_backlog_recv; 544 sk->sk_protocol = PX_PROTO_OL2TP; 545 sk->sk_family = PF_PPPOX; 546 sk->sk_state = PPPOX_NONE; 547 sk->sk_type = SOCK_STREAM; 548 sk->sk_destruct = pppol2tp_session_destruct; 549 550 error = 0; 551 552 out: 553 return error; 554 } 555 556 #if IS_ENABLED(CONFIG_L2TP_DEBUGFS) 557 static void pppol2tp_show(struct seq_file *m, void *arg) 558 { 559 struct l2tp_session *session = arg; 560 struct pppol2tp_session *ps = l2tp_session_priv(session); 561 562 if (ps) { 563 struct pppox_sock *po = pppox_sk(ps->sock); 564 if (po) 565 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan)); 566 } 567 } 568 #endif 569 570 /* connect() handler. Attach a PPPoX socket to a tunnel UDP socket 571 */ 572 static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr, 573 int sockaddr_len, int flags) 574 { 575 struct sock *sk = sock->sk; 576 struct sockaddr_pppol2tp *sp = (struct sockaddr_pppol2tp *) uservaddr; 577 struct pppox_sock *po = pppox_sk(sk); 578 struct l2tp_session *session = NULL; 579 struct l2tp_tunnel *tunnel; 580 struct pppol2tp_session *ps; 581 struct dst_entry *dst; 582 struct l2tp_session_cfg cfg = { 0, }; 583 int error = 0; 584 u32 tunnel_id, peer_tunnel_id; 585 u32 session_id, peer_session_id; 586 bool drop_refcnt = false; 587 int ver = 2; 588 int fd; 589 590 lock_sock(sk); 591 592 error = -EINVAL; 593 if (sp->sa_protocol != PX_PROTO_OL2TP) 594 goto end; 595 596 /* Check for already bound sockets */ 597 error = -EBUSY; 598 if (sk->sk_state & PPPOX_CONNECTED) 599 goto end; 600 601 /* We don't supporting rebinding anyway */ 602 error = -EALREADY; 603 if (sk->sk_user_data) 604 goto end; /* socket is already attached */ 605 606 /* Get params from socket address. Handle L2TPv2 and L2TPv3. 607 * This is nasty because there are different sockaddr_pppol2tp 608 * structs for L2TPv2, L2TPv3, over IPv4 and IPv6. We use 609 * the sockaddr size to determine which structure the caller 610 * is using. 611 */ 612 peer_tunnel_id = 0; 613 if (sockaddr_len == sizeof(struct sockaddr_pppol2tp)) { 614 fd = sp->pppol2tp.fd; 615 tunnel_id = sp->pppol2tp.s_tunnel; 616 peer_tunnel_id = sp->pppol2tp.d_tunnel; 617 session_id = sp->pppol2tp.s_session; 618 peer_session_id = sp->pppol2tp.d_session; 619 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpv3)) { 620 struct sockaddr_pppol2tpv3 *sp3 = 621 (struct sockaddr_pppol2tpv3 *) sp; 622 ver = 3; 623 fd = sp3->pppol2tp.fd; 624 tunnel_id = sp3->pppol2tp.s_tunnel; 625 peer_tunnel_id = sp3->pppol2tp.d_tunnel; 626 session_id = sp3->pppol2tp.s_session; 627 peer_session_id = sp3->pppol2tp.d_session; 628 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpin6)) { 629 struct sockaddr_pppol2tpin6 *sp6 = 630 (struct sockaddr_pppol2tpin6 *) sp; 631 fd = sp6->pppol2tp.fd; 632 tunnel_id = sp6->pppol2tp.s_tunnel; 633 peer_tunnel_id = sp6->pppol2tp.d_tunnel; 634 session_id = sp6->pppol2tp.s_session; 635 peer_session_id = sp6->pppol2tp.d_session; 636 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpv3in6)) { 637 struct sockaddr_pppol2tpv3in6 *sp6 = 638 (struct sockaddr_pppol2tpv3in6 *) sp; 639 ver = 3; 640 fd = sp6->pppol2tp.fd; 641 tunnel_id = sp6->pppol2tp.s_tunnel; 642 peer_tunnel_id = sp6->pppol2tp.d_tunnel; 643 session_id = sp6->pppol2tp.s_session; 644 peer_session_id = sp6->pppol2tp.d_session; 645 } else { 646 error = -EINVAL; 647 goto end; /* bad socket address */ 648 } 649 650 /* Don't bind if tunnel_id is 0 */ 651 error = -EINVAL; 652 if (tunnel_id == 0) 653 goto end; 654 655 tunnel = l2tp_tunnel_find(sock_net(sk), tunnel_id); 656 657 /* Special case: create tunnel context if session_id and 658 * peer_session_id is 0. Otherwise look up tunnel using supplied 659 * tunnel id. 660 */ 661 if ((session_id == 0) && (peer_session_id == 0)) { 662 if (tunnel == NULL) { 663 struct l2tp_tunnel_cfg tcfg = { 664 .encap = L2TP_ENCAPTYPE_UDP, 665 .debug = 0, 666 }; 667 error = l2tp_tunnel_create(sock_net(sk), fd, ver, tunnel_id, peer_tunnel_id, &tcfg, &tunnel); 668 if (error < 0) 669 goto end; 670 } 671 } else { 672 /* Error if we can't find the tunnel */ 673 error = -ENOENT; 674 if (tunnel == NULL) 675 goto end; 676 677 /* Error if socket is not prepped */ 678 if (tunnel->sock == NULL) 679 goto end; 680 } 681 682 if (tunnel->recv_payload_hook == NULL) 683 tunnel->recv_payload_hook = pppol2tp_recv_payload_hook; 684 685 if (tunnel->peer_tunnel_id == 0) 686 tunnel->peer_tunnel_id = peer_tunnel_id; 687 688 session = l2tp_session_get(sock_net(sk), tunnel, session_id, false); 689 if (session) { 690 drop_refcnt = true; 691 ps = l2tp_session_priv(session); 692 693 /* Using a pre-existing session is fine as long as it hasn't 694 * been connected yet. 695 */ 696 if (ps->sock) { 697 error = -EEXIST; 698 goto end; 699 } 700 701 /* consistency checks */ 702 if (ps->tunnel_sock != tunnel->sock) { 703 error = -EEXIST; 704 goto end; 705 } 706 } else { 707 /* Default MTU must allow space for UDP/L2TP/PPP headers */ 708 cfg.mtu = 1500 - PPPOL2TP_HEADER_OVERHEAD; 709 cfg.mru = cfg.mtu; 710 711 session = l2tp_session_create(sizeof(struct pppol2tp_session), 712 tunnel, session_id, 713 peer_session_id, &cfg); 714 if (IS_ERR(session)) { 715 error = PTR_ERR(session); 716 goto end; 717 } 718 } 719 720 /* Associate session with its PPPoL2TP socket */ 721 ps = l2tp_session_priv(session); 722 ps->owner = current->pid; 723 ps->sock = sk; 724 ps->tunnel_sock = tunnel->sock; 725 726 session->recv_skb = pppol2tp_recv; 727 session->session_close = pppol2tp_session_close; 728 #if IS_ENABLED(CONFIG_L2TP_DEBUGFS) 729 session->show = pppol2tp_show; 730 #endif 731 732 /* We need to know each time a skb is dropped from the reorder 733 * queue. 734 */ 735 session->ref = pppol2tp_session_sock_hold; 736 session->deref = pppol2tp_session_sock_put; 737 738 /* If PMTU discovery was enabled, use the MTU that was discovered */ 739 dst = sk_dst_get(tunnel->sock); 740 if (dst != NULL) { 741 u32 pmtu = dst_mtu(dst); 742 743 if (pmtu != 0) 744 session->mtu = session->mru = pmtu - 745 PPPOL2TP_HEADER_OVERHEAD; 746 dst_release(dst); 747 } 748 749 /* Special case: if source & dest session_id == 0x0000, this 750 * socket is being created to manage the tunnel. Just set up 751 * the internal context for use by ioctl() and sockopt() 752 * handlers. 753 */ 754 if ((session->session_id == 0) && 755 (session->peer_session_id == 0)) { 756 error = 0; 757 goto out_no_ppp; 758 } 759 760 /* The only header we need to worry about is the L2TP 761 * header. This size is different depending on whether 762 * sequence numbers are enabled for the data channel. 763 */ 764 po->chan.hdrlen = PPPOL2TP_L2TP_HDR_SIZE_NOSEQ; 765 766 po->chan.private = sk; 767 po->chan.ops = &pppol2tp_chan_ops; 768 po->chan.mtu = session->mtu; 769 770 error = ppp_register_net_channel(sock_net(sk), &po->chan); 771 if (error) 772 goto end; 773 774 out_no_ppp: 775 /* This is how we get the session context from the socket. */ 776 sk->sk_user_data = session; 777 sk->sk_state = PPPOX_CONNECTED; 778 l2tp_info(session, L2TP_MSG_CONTROL, "%s: created\n", 779 session->name); 780 781 end: 782 if (drop_refcnt) 783 l2tp_session_dec_refcount(session); 784 release_sock(sk); 785 786 return error; 787 } 788 789 #ifdef CONFIG_L2TP_V3 790 791 /* Called when creating sessions via the netlink interface. 792 */ 793 static int pppol2tp_session_create(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg) 794 { 795 int error; 796 struct l2tp_tunnel *tunnel; 797 struct l2tp_session *session; 798 struct pppol2tp_session *ps; 799 800 tunnel = l2tp_tunnel_find(net, tunnel_id); 801 802 /* Error if we can't find the tunnel */ 803 error = -ENOENT; 804 if (tunnel == NULL) 805 goto out; 806 807 /* Error if tunnel socket is not prepped */ 808 if (tunnel->sock == NULL) 809 goto out; 810 811 /* Default MTU values. */ 812 if (cfg->mtu == 0) 813 cfg->mtu = 1500 - PPPOL2TP_HEADER_OVERHEAD; 814 if (cfg->mru == 0) 815 cfg->mru = cfg->mtu; 816 817 /* Allocate and initialize a new session context. */ 818 session = l2tp_session_create(sizeof(struct pppol2tp_session), 819 tunnel, session_id, 820 peer_session_id, cfg); 821 if (IS_ERR(session)) { 822 error = PTR_ERR(session); 823 goto out; 824 } 825 826 ps = l2tp_session_priv(session); 827 ps->tunnel_sock = tunnel->sock; 828 829 l2tp_info(session, L2TP_MSG_CONTROL, "%s: created\n", 830 session->name); 831 832 error = 0; 833 834 out: 835 return error; 836 } 837 838 #endif /* CONFIG_L2TP_V3 */ 839 840 /* getname() support. 841 */ 842 static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr, 843 int *usockaddr_len, int peer) 844 { 845 int len = 0; 846 int error = 0; 847 struct l2tp_session *session; 848 struct l2tp_tunnel *tunnel; 849 struct sock *sk = sock->sk; 850 struct inet_sock *inet; 851 struct pppol2tp_session *pls; 852 853 error = -ENOTCONN; 854 if (sk == NULL) 855 goto end; 856 if (!(sk->sk_state & PPPOX_CONNECTED)) 857 goto end; 858 859 error = -EBADF; 860 session = pppol2tp_sock_to_session(sk); 861 if (session == NULL) 862 goto end; 863 864 pls = l2tp_session_priv(session); 865 tunnel = l2tp_sock_to_tunnel(pls->tunnel_sock); 866 if (tunnel == NULL) 867 goto end_put_sess; 868 869 inet = inet_sk(tunnel->sock); 870 if ((tunnel->version == 2) && (tunnel->sock->sk_family == AF_INET)) { 871 struct sockaddr_pppol2tp sp; 872 len = sizeof(sp); 873 memset(&sp, 0, len); 874 sp.sa_family = AF_PPPOX; 875 sp.sa_protocol = PX_PROTO_OL2TP; 876 sp.pppol2tp.fd = tunnel->fd; 877 sp.pppol2tp.pid = pls->owner; 878 sp.pppol2tp.s_tunnel = tunnel->tunnel_id; 879 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id; 880 sp.pppol2tp.s_session = session->session_id; 881 sp.pppol2tp.d_session = session->peer_session_id; 882 sp.pppol2tp.addr.sin_family = AF_INET; 883 sp.pppol2tp.addr.sin_port = inet->inet_dport; 884 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr; 885 memcpy(uaddr, &sp, len); 886 #if IS_ENABLED(CONFIG_IPV6) 887 } else if ((tunnel->version == 2) && 888 (tunnel->sock->sk_family == AF_INET6)) { 889 struct sockaddr_pppol2tpin6 sp; 890 891 len = sizeof(sp); 892 memset(&sp, 0, len); 893 sp.sa_family = AF_PPPOX; 894 sp.sa_protocol = PX_PROTO_OL2TP; 895 sp.pppol2tp.fd = tunnel->fd; 896 sp.pppol2tp.pid = pls->owner; 897 sp.pppol2tp.s_tunnel = tunnel->tunnel_id; 898 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id; 899 sp.pppol2tp.s_session = session->session_id; 900 sp.pppol2tp.d_session = session->peer_session_id; 901 sp.pppol2tp.addr.sin6_family = AF_INET6; 902 sp.pppol2tp.addr.sin6_port = inet->inet_dport; 903 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr, 904 sizeof(tunnel->sock->sk_v6_daddr)); 905 memcpy(uaddr, &sp, len); 906 } else if ((tunnel->version == 3) && 907 (tunnel->sock->sk_family == AF_INET6)) { 908 struct sockaddr_pppol2tpv3in6 sp; 909 910 len = sizeof(sp); 911 memset(&sp, 0, len); 912 sp.sa_family = AF_PPPOX; 913 sp.sa_protocol = PX_PROTO_OL2TP; 914 sp.pppol2tp.fd = tunnel->fd; 915 sp.pppol2tp.pid = pls->owner; 916 sp.pppol2tp.s_tunnel = tunnel->tunnel_id; 917 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id; 918 sp.pppol2tp.s_session = session->session_id; 919 sp.pppol2tp.d_session = session->peer_session_id; 920 sp.pppol2tp.addr.sin6_family = AF_INET6; 921 sp.pppol2tp.addr.sin6_port = inet->inet_dport; 922 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr, 923 sizeof(tunnel->sock->sk_v6_daddr)); 924 memcpy(uaddr, &sp, len); 925 #endif 926 } else if (tunnel->version == 3) { 927 struct sockaddr_pppol2tpv3 sp; 928 len = sizeof(sp); 929 memset(&sp, 0, len); 930 sp.sa_family = AF_PPPOX; 931 sp.sa_protocol = PX_PROTO_OL2TP; 932 sp.pppol2tp.fd = tunnel->fd; 933 sp.pppol2tp.pid = pls->owner; 934 sp.pppol2tp.s_tunnel = tunnel->tunnel_id; 935 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id; 936 sp.pppol2tp.s_session = session->session_id; 937 sp.pppol2tp.d_session = session->peer_session_id; 938 sp.pppol2tp.addr.sin_family = AF_INET; 939 sp.pppol2tp.addr.sin_port = inet->inet_dport; 940 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr; 941 memcpy(uaddr, &sp, len); 942 } 943 944 *usockaddr_len = len; 945 error = 0; 946 947 sock_put(pls->tunnel_sock); 948 end_put_sess: 949 sock_put(sk); 950 end: 951 return error; 952 } 953 954 /**************************************************************************** 955 * ioctl() handlers. 956 * 957 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP 958 * sockets. However, in order to control kernel tunnel features, we allow 959 * userspace to create a special "tunnel" PPPoX socket which is used for 960 * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow 961 * the user application to issue L2TP setsockopt(), getsockopt() and ioctl() 962 * calls. 963 ****************************************************************************/ 964 965 static void pppol2tp_copy_stats(struct pppol2tp_ioc_stats *dest, 966 struct l2tp_stats *stats) 967 { 968 dest->tx_packets = atomic_long_read(&stats->tx_packets); 969 dest->tx_bytes = atomic_long_read(&stats->tx_bytes); 970 dest->tx_errors = atomic_long_read(&stats->tx_errors); 971 dest->rx_packets = atomic_long_read(&stats->rx_packets); 972 dest->rx_bytes = atomic_long_read(&stats->rx_bytes); 973 dest->rx_seq_discards = atomic_long_read(&stats->rx_seq_discards); 974 dest->rx_oos_packets = atomic_long_read(&stats->rx_oos_packets); 975 dest->rx_errors = atomic_long_read(&stats->rx_errors); 976 } 977 978 /* Session ioctl helper. 979 */ 980 static int pppol2tp_session_ioctl(struct l2tp_session *session, 981 unsigned int cmd, unsigned long arg) 982 { 983 struct ifreq ifr; 984 int err = 0; 985 struct sock *sk; 986 int val = (int) arg; 987 struct pppol2tp_session *ps = l2tp_session_priv(session); 988 struct l2tp_tunnel *tunnel = session->tunnel; 989 struct pppol2tp_ioc_stats stats; 990 991 l2tp_dbg(session, L2TP_MSG_CONTROL, 992 "%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n", 993 session->name, cmd, arg); 994 995 sk = ps->sock; 996 sock_hold(sk); 997 998 switch (cmd) { 999 case SIOCGIFMTU: 1000 err = -ENXIO; 1001 if (!(sk->sk_state & PPPOX_CONNECTED)) 1002 break; 1003 1004 err = -EFAULT; 1005 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq))) 1006 break; 1007 ifr.ifr_mtu = session->mtu; 1008 if (copy_to_user((void __user *) arg, &ifr, sizeof(struct ifreq))) 1009 break; 1010 1011 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get mtu=%d\n", 1012 session->name, session->mtu); 1013 err = 0; 1014 break; 1015 1016 case SIOCSIFMTU: 1017 err = -ENXIO; 1018 if (!(sk->sk_state & PPPOX_CONNECTED)) 1019 break; 1020 1021 err = -EFAULT; 1022 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq))) 1023 break; 1024 1025 session->mtu = ifr.ifr_mtu; 1026 1027 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set mtu=%d\n", 1028 session->name, session->mtu); 1029 err = 0; 1030 break; 1031 1032 case PPPIOCGMRU: 1033 err = -ENXIO; 1034 if (!(sk->sk_state & PPPOX_CONNECTED)) 1035 break; 1036 1037 err = -EFAULT; 1038 if (put_user(session->mru, (int __user *) arg)) 1039 break; 1040 1041 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get mru=%d\n", 1042 session->name, session->mru); 1043 err = 0; 1044 break; 1045 1046 case PPPIOCSMRU: 1047 err = -ENXIO; 1048 if (!(sk->sk_state & PPPOX_CONNECTED)) 1049 break; 1050 1051 err = -EFAULT; 1052 if (get_user(val, (int __user *) arg)) 1053 break; 1054 1055 session->mru = val; 1056 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set mru=%d\n", 1057 session->name, session->mru); 1058 err = 0; 1059 break; 1060 1061 case PPPIOCGFLAGS: 1062 err = -EFAULT; 1063 if (put_user(ps->flags, (int __user *) arg)) 1064 break; 1065 1066 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get flags=%d\n", 1067 session->name, ps->flags); 1068 err = 0; 1069 break; 1070 1071 case PPPIOCSFLAGS: 1072 err = -EFAULT; 1073 if (get_user(val, (int __user *) arg)) 1074 break; 1075 ps->flags = val; 1076 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set flags=%d\n", 1077 session->name, ps->flags); 1078 err = 0; 1079 break; 1080 1081 case PPPIOCGL2TPSTATS: 1082 err = -ENXIO; 1083 if (!(sk->sk_state & PPPOX_CONNECTED)) 1084 break; 1085 1086 memset(&stats, 0, sizeof(stats)); 1087 stats.tunnel_id = tunnel->tunnel_id; 1088 stats.session_id = session->session_id; 1089 pppol2tp_copy_stats(&stats, &session->stats); 1090 if (copy_to_user((void __user *) arg, &stats, 1091 sizeof(stats))) 1092 break; 1093 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get L2TP stats\n", 1094 session->name); 1095 err = 0; 1096 break; 1097 1098 default: 1099 err = -ENOSYS; 1100 break; 1101 } 1102 1103 sock_put(sk); 1104 1105 return err; 1106 } 1107 1108 /* Tunnel ioctl helper. 1109 * 1110 * Note the special handling for PPPIOCGL2TPSTATS below. If the ioctl data 1111 * specifies a session_id, the session ioctl handler is called. This allows an 1112 * application to retrieve session stats via a tunnel socket. 1113 */ 1114 static int pppol2tp_tunnel_ioctl(struct l2tp_tunnel *tunnel, 1115 unsigned int cmd, unsigned long arg) 1116 { 1117 int err = 0; 1118 struct sock *sk; 1119 struct pppol2tp_ioc_stats stats; 1120 1121 l2tp_dbg(tunnel, L2TP_MSG_CONTROL, 1122 "%s: pppol2tp_tunnel_ioctl(cmd=%#x, arg=%#lx)\n", 1123 tunnel->name, cmd, arg); 1124 1125 sk = tunnel->sock; 1126 sock_hold(sk); 1127 1128 switch (cmd) { 1129 case PPPIOCGL2TPSTATS: 1130 err = -ENXIO; 1131 if (!(sk->sk_state & PPPOX_CONNECTED)) 1132 break; 1133 1134 if (copy_from_user(&stats, (void __user *) arg, 1135 sizeof(stats))) { 1136 err = -EFAULT; 1137 break; 1138 } 1139 if (stats.session_id != 0) { 1140 /* resend to session ioctl handler */ 1141 struct l2tp_session *session = 1142 l2tp_session_get(sock_net(sk), tunnel, 1143 stats.session_id, true); 1144 1145 if (session) { 1146 err = pppol2tp_session_ioctl(session, cmd, 1147 arg); 1148 if (session->deref) 1149 session->deref(session); 1150 l2tp_session_dec_refcount(session); 1151 } else { 1152 err = -EBADR; 1153 } 1154 break; 1155 } 1156 #ifdef CONFIG_XFRM 1157 stats.using_ipsec = (sk->sk_policy[0] || sk->sk_policy[1]) ? 1 : 0; 1158 #endif 1159 pppol2tp_copy_stats(&stats, &tunnel->stats); 1160 if (copy_to_user((void __user *) arg, &stats, sizeof(stats))) { 1161 err = -EFAULT; 1162 break; 1163 } 1164 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: get L2TP stats\n", 1165 tunnel->name); 1166 err = 0; 1167 break; 1168 1169 default: 1170 err = -ENOSYS; 1171 break; 1172 } 1173 1174 sock_put(sk); 1175 1176 return err; 1177 } 1178 1179 /* Main ioctl() handler. 1180 * Dispatch to tunnel or session helpers depending on the socket. 1181 */ 1182 static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd, 1183 unsigned long arg) 1184 { 1185 struct sock *sk = sock->sk; 1186 struct l2tp_session *session; 1187 struct l2tp_tunnel *tunnel; 1188 struct pppol2tp_session *ps; 1189 int err; 1190 1191 if (!sk) 1192 return 0; 1193 1194 err = -EBADF; 1195 if (sock_flag(sk, SOCK_DEAD) != 0) 1196 goto end; 1197 1198 err = -ENOTCONN; 1199 if ((sk->sk_user_data == NULL) || 1200 (!(sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND)))) 1201 goto end; 1202 1203 /* Get session context from the socket */ 1204 err = -EBADF; 1205 session = pppol2tp_sock_to_session(sk); 1206 if (session == NULL) 1207 goto end; 1208 1209 /* Special case: if session's session_id is zero, treat ioctl as a 1210 * tunnel ioctl 1211 */ 1212 ps = l2tp_session_priv(session); 1213 if ((session->session_id == 0) && 1214 (session->peer_session_id == 0)) { 1215 err = -EBADF; 1216 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock); 1217 if (tunnel == NULL) 1218 goto end_put_sess; 1219 1220 err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg); 1221 sock_put(ps->tunnel_sock); 1222 goto end_put_sess; 1223 } 1224 1225 err = pppol2tp_session_ioctl(session, cmd, arg); 1226 1227 end_put_sess: 1228 sock_put(sk); 1229 end: 1230 return err; 1231 } 1232 1233 /***************************************************************************** 1234 * setsockopt() / getsockopt() support. 1235 * 1236 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP 1237 * sockets. In order to control kernel tunnel features, we allow userspace to 1238 * create a special "tunnel" PPPoX socket which is used for control only. 1239 * Tunnel PPPoX sockets have session_id == 0 and simply allow the user 1240 * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls. 1241 *****************************************************************************/ 1242 1243 /* Tunnel setsockopt() helper. 1244 */ 1245 static int pppol2tp_tunnel_setsockopt(struct sock *sk, 1246 struct l2tp_tunnel *tunnel, 1247 int optname, int val) 1248 { 1249 int err = 0; 1250 1251 switch (optname) { 1252 case PPPOL2TP_SO_DEBUG: 1253 tunnel->debug = val; 1254 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: set debug=%x\n", 1255 tunnel->name, tunnel->debug); 1256 break; 1257 1258 default: 1259 err = -ENOPROTOOPT; 1260 break; 1261 } 1262 1263 return err; 1264 } 1265 1266 /* Session setsockopt helper. 1267 */ 1268 static int pppol2tp_session_setsockopt(struct sock *sk, 1269 struct l2tp_session *session, 1270 int optname, int val) 1271 { 1272 int err = 0; 1273 struct pppol2tp_session *ps = l2tp_session_priv(session); 1274 1275 switch (optname) { 1276 case PPPOL2TP_SO_RECVSEQ: 1277 if ((val != 0) && (val != 1)) { 1278 err = -EINVAL; 1279 break; 1280 } 1281 session->recv_seq = !!val; 1282 l2tp_info(session, L2TP_MSG_CONTROL, 1283 "%s: set recv_seq=%d\n", 1284 session->name, session->recv_seq); 1285 break; 1286 1287 case PPPOL2TP_SO_SENDSEQ: 1288 if ((val != 0) && (val != 1)) { 1289 err = -EINVAL; 1290 break; 1291 } 1292 session->send_seq = !!val; 1293 { 1294 struct sock *ssk = ps->sock; 1295 struct pppox_sock *po = pppox_sk(ssk); 1296 po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ : 1297 PPPOL2TP_L2TP_HDR_SIZE_NOSEQ; 1298 } 1299 l2tp_session_set_header_len(session, session->tunnel->version); 1300 l2tp_info(session, L2TP_MSG_CONTROL, 1301 "%s: set send_seq=%d\n", 1302 session->name, session->send_seq); 1303 break; 1304 1305 case PPPOL2TP_SO_LNSMODE: 1306 if ((val != 0) && (val != 1)) { 1307 err = -EINVAL; 1308 break; 1309 } 1310 session->lns_mode = !!val; 1311 l2tp_info(session, L2TP_MSG_CONTROL, 1312 "%s: set lns_mode=%d\n", 1313 session->name, session->lns_mode); 1314 break; 1315 1316 case PPPOL2TP_SO_DEBUG: 1317 session->debug = val; 1318 l2tp_info(session, L2TP_MSG_CONTROL, "%s: set debug=%x\n", 1319 session->name, session->debug); 1320 break; 1321 1322 case PPPOL2TP_SO_REORDERTO: 1323 session->reorder_timeout = msecs_to_jiffies(val); 1324 l2tp_info(session, L2TP_MSG_CONTROL, 1325 "%s: set reorder_timeout=%d\n", 1326 session->name, session->reorder_timeout); 1327 break; 1328 1329 default: 1330 err = -ENOPROTOOPT; 1331 break; 1332 } 1333 1334 return err; 1335 } 1336 1337 /* Main setsockopt() entry point. 1338 * Does API checks, then calls either the tunnel or session setsockopt 1339 * handler, according to whether the PPPoL2TP socket is a for a regular 1340 * session or the special tunnel type. 1341 */ 1342 static int pppol2tp_setsockopt(struct socket *sock, int level, int optname, 1343 char __user *optval, unsigned int optlen) 1344 { 1345 struct sock *sk = sock->sk; 1346 struct l2tp_session *session; 1347 struct l2tp_tunnel *tunnel; 1348 struct pppol2tp_session *ps; 1349 int val; 1350 int err; 1351 1352 if (level != SOL_PPPOL2TP) 1353 return -EINVAL; 1354 1355 if (optlen < sizeof(int)) 1356 return -EINVAL; 1357 1358 if (get_user(val, (int __user *)optval)) 1359 return -EFAULT; 1360 1361 err = -ENOTCONN; 1362 if (sk->sk_user_data == NULL) 1363 goto end; 1364 1365 /* Get session context from the socket */ 1366 err = -EBADF; 1367 session = pppol2tp_sock_to_session(sk); 1368 if (session == NULL) 1369 goto end; 1370 1371 /* Special case: if session_id == 0x0000, treat as operation on tunnel 1372 */ 1373 ps = l2tp_session_priv(session); 1374 if ((session->session_id == 0) && 1375 (session->peer_session_id == 0)) { 1376 err = -EBADF; 1377 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock); 1378 if (tunnel == NULL) 1379 goto end_put_sess; 1380 1381 err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val); 1382 sock_put(ps->tunnel_sock); 1383 } else 1384 err = pppol2tp_session_setsockopt(sk, session, optname, val); 1385 1386 end_put_sess: 1387 sock_put(sk); 1388 end: 1389 return err; 1390 } 1391 1392 /* Tunnel getsockopt helper. Called with sock locked. 1393 */ 1394 static int pppol2tp_tunnel_getsockopt(struct sock *sk, 1395 struct l2tp_tunnel *tunnel, 1396 int optname, int *val) 1397 { 1398 int err = 0; 1399 1400 switch (optname) { 1401 case PPPOL2TP_SO_DEBUG: 1402 *val = tunnel->debug; 1403 l2tp_info(tunnel, L2TP_MSG_CONTROL, "%s: get debug=%x\n", 1404 tunnel->name, tunnel->debug); 1405 break; 1406 1407 default: 1408 err = -ENOPROTOOPT; 1409 break; 1410 } 1411 1412 return err; 1413 } 1414 1415 /* Session getsockopt helper. Called with sock locked. 1416 */ 1417 static int pppol2tp_session_getsockopt(struct sock *sk, 1418 struct l2tp_session *session, 1419 int optname, int *val) 1420 { 1421 int err = 0; 1422 1423 switch (optname) { 1424 case PPPOL2TP_SO_RECVSEQ: 1425 *val = session->recv_seq; 1426 l2tp_info(session, L2TP_MSG_CONTROL, 1427 "%s: get recv_seq=%d\n", session->name, *val); 1428 break; 1429 1430 case PPPOL2TP_SO_SENDSEQ: 1431 *val = session->send_seq; 1432 l2tp_info(session, L2TP_MSG_CONTROL, 1433 "%s: get send_seq=%d\n", session->name, *val); 1434 break; 1435 1436 case PPPOL2TP_SO_LNSMODE: 1437 *val = session->lns_mode; 1438 l2tp_info(session, L2TP_MSG_CONTROL, 1439 "%s: get lns_mode=%d\n", session->name, *val); 1440 break; 1441 1442 case PPPOL2TP_SO_DEBUG: 1443 *val = session->debug; 1444 l2tp_info(session, L2TP_MSG_CONTROL, "%s: get debug=%d\n", 1445 session->name, *val); 1446 break; 1447 1448 case PPPOL2TP_SO_REORDERTO: 1449 *val = (int) jiffies_to_msecs(session->reorder_timeout); 1450 l2tp_info(session, L2TP_MSG_CONTROL, 1451 "%s: get reorder_timeout=%d\n", session->name, *val); 1452 break; 1453 1454 default: 1455 err = -ENOPROTOOPT; 1456 } 1457 1458 return err; 1459 } 1460 1461 /* Main getsockopt() entry point. 1462 * Does API checks, then calls either the tunnel or session getsockopt 1463 * handler, according to whether the PPPoX socket is a for a regular session 1464 * or the special tunnel type. 1465 */ 1466 static int pppol2tp_getsockopt(struct socket *sock, int level, int optname, 1467 char __user *optval, int __user *optlen) 1468 { 1469 struct sock *sk = sock->sk; 1470 struct l2tp_session *session; 1471 struct l2tp_tunnel *tunnel; 1472 int val, len; 1473 int err; 1474 struct pppol2tp_session *ps; 1475 1476 if (level != SOL_PPPOL2TP) 1477 return -EINVAL; 1478 1479 if (get_user(len, optlen)) 1480 return -EFAULT; 1481 1482 len = min_t(unsigned int, len, sizeof(int)); 1483 1484 if (len < 0) 1485 return -EINVAL; 1486 1487 err = -ENOTCONN; 1488 if (sk->sk_user_data == NULL) 1489 goto end; 1490 1491 /* Get the session context */ 1492 err = -EBADF; 1493 session = pppol2tp_sock_to_session(sk); 1494 if (session == NULL) 1495 goto end; 1496 1497 /* Special case: if session_id == 0x0000, treat as operation on tunnel */ 1498 ps = l2tp_session_priv(session); 1499 if ((session->session_id == 0) && 1500 (session->peer_session_id == 0)) { 1501 err = -EBADF; 1502 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock); 1503 if (tunnel == NULL) 1504 goto end_put_sess; 1505 1506 err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val); 1507 sock_put(ps->tunnel_sock); 1508 if (err) 1509 goto end_put_sess; 1510 } else { 1511 err = pppol2tp_session_getsockopt(sk, session, optname, &val); 1512 if (err) 1513 goto end_put_sess; 1514 } 1515 1516 err = -EFAULT; 1517 if (put_user(len, optlen)) 1518 goto end_put_sess; 1519 1520 if (copy_to_user((void __user *) optval, &val, len)) 1521 goto end_put_sess; 1522 1523 err = 0; 1524 1525 end_put_sess: 1526 sock_put(sk); 1527 end: 1528 return err; 1529 } 1530 1531 /***************************************************************************** 1532 * /proc filesystem for debug 1533 * Since the original pppol2tp driver provided /proc/net/pppol2tp for 1534 * L2TPv2, we dump only L2TPv2 tunnels and sessions here. 1535 *****************************************************************************/ 1536 1537 static unsigned int pppol2tp_net_id; 1538 1539 #ifdef CONFIG_PROC_FS 1540 1541 struct pppol2tp_seq_data { 1542 struct seq_net_private p; 1543 int tunnel_idx; /* current tunnel */ 1544 int session_idx; /* index of session within current tunnel */ 1545 struct l2tp_tunnel *tunnel; 1546 struct l2tp_session *session; /* NULL means get next tunnel */ 1547 }; 1548 1549 static void pppol2tp_next_tunnel(struct net *net, struct pppol2tp_seq_data *pd) 1550 { 1551 for (;;) { 1552 pd->tunnel = l2tp_tunnel_find_nth(net, pd->tunnel_idx); 1553 pd->tunnel_idx++; 1554 1555 if (pd->tunnel == NULL) 1556 break; 1557 1558 /* Ignore L2TPv3 tunnels */ 1559 if (pd->tunnel->version < 3) 1560 break; 1561 } 1562 } 1563 1564 static void pppol2tp_next_session(struct net *net, struct pppol2tp_seq_data *pd) 1565 { 1566 pd->session = l2tp_session_get_nth(pd->tunnel, pd->session_idx, true); 1567 pd->session_idx++; 1568 1569 if (pd->session == NULL) { 1570 pd->session_idx = 0; 1571 pppol2tp_next_tunnel(net, pd); 1572 } 1573 } 1574 1575 static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs) 1576 { 1577 struct pppol2tp_seq_data *pd = SEQ_START_TOKEN; 1578 loff_t pos = *offs; 1579 struct net *net; 1580 1581 if (!pos) 1582 goto out; 1583 1584 BUG_ON(m->private == NULL); 1585 pd = m->private; 1586 net = seq_file_net(m); 1587 1588 if (pd->tunnel == NULL) 1589 pppol2tp_next_tunnel(net, pd); 1590 else 1591 pppol2tp_next_session(net, pd); 1592 1593 /* NULL tunnel and session indicates end of list */ 1594 if ((pd->tunnel == NULL) && (pd->session == NULL)) 1595 pd = NULL; 1596 1597 out: 1598 return pd; 1599 } 1600 1601 static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos) 1602 { 1603 (*pos)++; 1604 return NULL; 1605 } 1606 1607 static void pppol2tp_seq_stop(struct seq_file *p, void *v) 1608 { 1609 /* nothing to do */ 1610 } 1611 1612 static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v) 1613 { 1614 struct l2tp_tunnel *tunnel = v; 1615 1616 seq_printf(m, "\nTUNNEL '%s', %c %d\n", 1617 tunnel->name, 1618 (tunnel == tunnel->sock->sk_user_data) ? 'Y' : 'N', 1619 atomic_read(&tunnel->ref_count) - 1); 1620 seq_printf(m, " %08x %ld/%ld/%ld %ld/%ld/%ld\n", 1621 tunnel->debug, 1622 atomic_long_read(&tunnel->stats.tx_packets), 1623 atomic_long_read(&tunnel->stats.tx_bytes), 1624 atomic_long_read(&tunnel->stats.tx_errors), 1625 atomic_long_read(&tunnel->stats.rx_packets), 1626 atomic_long_read(&tunnel->stats.rx_bytes), 1627 atomic_long_read(&tunnel->stats.rx_errors)); 1628 } 1629 1630 static void pppol2tp_seq_session_show(struct seq_file *m, void *v) 1631 { 1632 struct l2tp_session *session = v; 1633 struct l2tp_tunnel *tunnel = session->tunnel; 1634 struct pppol2tp_session *ps = l2tp_session_priv(session); 1635 struct pppox_sock *po = pppox_sk(ps->sock); 1636 u32 ip = 0; 1637 u16 port = 0; 1638 1639 if (tunnel->sock) { 1640 struct inet_sock *inet = inet_sk(tunnel->sock); 1641 ip = ntohl(inet->inet_saddr); 1642 port = ntohs(inet->inet_sport); 1643 } 1644 1645 seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> " 1646 "%04X/%04X %d %c\n", 1647 session->name, ip, port, 1648 tunnel->tunnel_id, 1649 session->session_id, 1650 tunnel->peer_tunnel_id, 1651 session->peer_session_id, 1652 ps->sock->sk_state, 1653 (session == ps->sock->sk_user_data) ? 1654 'Y' : 'N'); 1655 seq_printf(m, " %d/%d/%c/%c/%s %08x %u\n", 1656 session->mtu, session->mru, 1657 session->recv_seq ? 'R' : '-', 1658 session->send_seq ? 'S' : '-', 1659 session->lns_mode ? "LNS" : "LAC", 1660 session->debug, 1661 jiffies_to_msecs(session->reorder_timeout)); 1662 seq_printf(m, " %hu/%hu %ld/%ld/%ld %ld/%ld/%ld\n", 1663 session->nr, session->ns, 1664 atomic_long_read(&session->stats.tx_packets), 1665 atomic_long_read(&session->stats.tx_bytes), 1666 atomic_long_read(&session->stats.tx_errors), 1667 atomic_long_read(&session->stats.rx_packets), 1668 atomic_long_read(&session->stats.rx_bytes), 1669 atomic_long_read(&session->stats.rx_errors)); 1670 1671 if (po) 1672 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan)); 1673 } 1674 1675 static int pppol2tp_seq_show(struct seq_file *m, void *v) 1676 { 1677 struct pppol2tp_seq_data *pd = v; 1678 1679 /* display header on line 1 */ 1680 if (v == SEQ_START_TOKEN) { 1681 seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n"); 1682 seq_puts(m, "TUNNEL name, user-data-ok session-count\n"); 1683 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); 1684 seq_puts(m, " SESSION name, addr/port src-tid/sid " 1685 "dest-tid/sid state user-data-ok\n"); 1686 seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n"); 1687 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); 1688 goto out; 1689 } 1690 1691 /* Show the tunnel or session context. 1692 */ 1693 if (!pd->session) { 1694 pppol2tp_seq_tunnel_show(m, pd->tunnel); 1695 } else { 1696 pppol2tp_seq_session_show(m, pd->session); 1697 if (pd->session->deref) 1698 pd->session->deref(pd->session); 1699 l2tp_session_dec_refcount(pd->session); 1700 } 1701 1702 out: 1703 return 0; 1704 } 1705 1706 static const struct seq_operations pppol2tp_seq_ops = { 1707 .start = pppol2tp_seq_start, 1708 .next = pppol2tp_seq_next, 1709 .stop = pppol2tp_seq_stop, 1710 .show = pppol2tp_seq_show, 1711 }; 1712 1713 /* Called when our /proc file is opened. We allocate data for use when 1714 * iterating our tunnel / session contexts and store it in the private 1715 * data of the seq_file. 1716 */ 1717 static int pppol2tp_proc_open(struct inode *inode, struct file *file) 1718 { 1719 return seq_open_net(inode, file, &pppol2tp_seq_ops, 1720 sizeof(struct pppol2tp_seq_data)); 1721 } 1722 1723 static const struct file_operations pppol2tp_proc_fops = { 1724 .owner = THIS_MODULE, 1725 .open = pppol2tp_proc_open, 1726 .read = seq_read, 1727 .llseek = seq_lseek, 1728 .release = seq_release_net, 1729 }; 1730 1731 #endif /* CONFIG_PROC_FS */ 1732 1733 /***************************************************************************** 1734 * Network namespace 1735 *****************************************************************************/ 1736 1737 static __net_init int pppol2tp_init_net(struct net *net) 1738 { 1739 struct proc_dir_entry *pde; 1740 int err = 0; 1741 1742 pde = proc_create("pppol2tp", S_IRUGO, net->proc_net, 1743 &pppol2tp_proc_fops); 1744 if (!pde) { 1745 err = -ENOMEM; 1746 goto out; 1747 } 1748 1749 out: 1750 return err; 1751 } 1752 1753 static __net_exit void pppol2tp_exit_net(struct net *net) 1754 { 1755 remove_proc_entry("pppol2tp", net->proc_net); 1756 } 1757 1758 static struct pernet_operations pppol2tp_net_ops = { 1759 .init = pppol2tp_init_net, 1760 .exit = pppol2tp_exit_net, 1761 .id = &pppol2tp_net_id, 1762 }; 1763 1764 /***************************************************************************** 1765 * Init and cleanup 1766 *****************************************************************************/ 1767 1768 static const struct proto_ops pppol2tp_ops = { 1769 .family = AF_PPPOX, 1770 .owner = THIS_MODULE, 1771 .release = pppol2tp_release, 1772 .bind = sock_no_bind, 1773 .connect = pppol2tp_connect, 1774 .socketpair = sock_no_socketpair, 1775 .accept = sock_no_accept, 1776 .getname = pppol2tp_getname, 1777 .poll = datagram_poll, 1778 .listen = sock_no_listen, 1779 .shutdown = sock_no_shutdown, 1780 .setsockopt = pppol2tp_setsockopt, 1781 .getsockopt = pppol2tp_getsockopt, 1782 .sendmsg = pppol2tp_sendmsg, 1783 .recvmsg = pppol2tp_recvmsg, 1784 .mmap = sock_no_mmap, 1785 .ioctl = pppox_ioctl, 1786 }; 1787 1788 static const struct pppox_proto pppol2tp_proto = { 1789 .create = pppol2tp_create, 1790 .ioctl = pppol2tp_ioctl, 1791 .owner = THIS_MODULE, 1792 }; 1793 1794 #ifdef CONFIG_L2TP_V3 1795 1796 static const struct l2tp_nl_cmd_ops pppol2tp_nl_cmd_ops = { 1797 .session_create = pppol2tp_session_create, 1798 .session_delete = l2tp_session_delete, 1799 }; 1800 1801 #endif /* CONFIG_L2TP_V3 */ 1802 1803 static int __init pppol2tp_init(void) 1804 { 1805 int err; 1806 1807 err = register_pernet_device(&pppol2tp_net_ops); 1808 if (err) 1809 goto out; 1810 1811 err = proto_register(&pppol2tp_sk_proto, 0); 1812 if (err) 1813 goto out_unregister_pppol2tp_pernet; 1814 1815 err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto); 1816 if (err) 1817 goto out_unregister_pppol2tp_proto; 1818 1819 #ifdef CONFIG_L2TP_V3 1820 err = l2tp_nl_register_ops(L2TP_PWTYPE_PPP, &pppol2tp_nl_cmd_ops); 1821 if (err) 1822 goto out_unregister_pppox; 1823 #endif 1824 1825 pr_info("PPPoL2TP kernel driver, %s\n", PPPOL2TP_DRV_VERSION); 1826 1827 out: 1828 return err; 1829 1830 #ifdef CONFIG_L2TP_V3 1831 out_unregister_pppox: 1832 unregister_pppox_proto(PX_PROTO_OL2TP); 1833 #endif 1834 out_unregister_pppol2tp_proto: 1835 proto_unregister(&pppol2tp_sk_proto); 1836 out_unregister_pppol2tp_pernet: 1837 unregister_pernet_device(&pppol2tp_net_ops); 1838 goto out; 1839 } 1840 1841 static void __exit pppol2tp_exit(void) 1842 { 1843 #ifdef CONFIG_L2TP_V3 1844 l2tp_nl_unregister_ops(L2TP_PWTYPE_PPP); 1845 #endif 1846 unregister_pppox_proto(PX_PROTO_OL2TP); 1847 proto_unregister(&pppol2tp_sk_proto); 1848 unregister_pernet_device(&pppol2tp_net_ops); 1849 } 1850 1851 module_init(pppol2tp_init); 1852 module_exit(pppol2tp_exit); 1853 1854 MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); 1855 MODULE_DESCRIPTION("PPP over L2TP over UDP"); 1856 MODULE_LICENSE("GPL"); 1857 MODULE_VERSION(PPPOL2TP_DRV_VERSION); 1858 MODULE_ALIAS_NET_PF_PROTO(PF_PPPOX, PX_PROTO_OL2TP); 1859 MODULE_ALIAS_L2TP_PWTYPE(7); 1860