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 */ 122struct 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 133static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb); 134 135static const struct ppp_channel_ops pppol2tp_chan_ops = { 136 .start_xmit = pppol2tp_xmit, 137}; 138 139static const struct proto_ops pppol2tp_ops; 140 141/* Helpers to obtain tunnel/session contexts from sockets. 142 */ 143static 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 159out: 160 return session; 161} 162 163/***************************************************************************** 164 * Receive data handling 165 *****************************************************************************/ 166 167static 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] == 0xff) && (skb->data[1] == 0x03)) 181 skb_pull(skb, 2); 182 183 return 0; 184} 185 186/* Receive message. This is the recvmsg for the PPPoL2TP socket. 187 */ 188static 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); 215end: 216 return err; 217} 218 219static 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 l2tp_dbg(session, PPPOL2TP_MSG_DATA, 234 "%s: recv %d byte data frame, passing to ppp\n", 235 session->name, data_len); 236 237 /* We need to forget all info related to the L2TP packet 238 * gathered in the skb as we are going to reuse the same 239 * skb for the inner packet. 240 * Namely we need to: 241 * - reset xfrm (IPSec) information as it applies to 242 * the outer L2TP packet and not to the inner one 243 * - release the dst to force a route lookup on the inner 244 * IP packet since skb->dst currently points to the dst 245 * of the UDP tunnel 246 * - reset netfilter information as it doesn't apply 247 * to the inner packet either 248 */ 249 secpath_reset(skb); 250 skb_dst_drop(skb); 251 nf_reset(skb); 252 253 po = pppox_sk(sk); 254 ppp_input(&po->chan, skb); 255 } else { 256 l2tp_dbg(session, PPPOL2TP_MSG_DATA, 257 "%s: recv %d byte data frame, passing to L2TP socket\n", 258 session->name, data_len); 259 260 if (sock_queue_rcv_skb(sk, skb) < 0) { 261 atomic_long_inc(&session->stats.rx_errors); 262 kfree_skb(skb); 263 } 264 } 265 266 return; 267 268no_sock: 269 l2tp_info(session, PPPOL2TP_MSG_DATA, "%s: no socket\n", session->name); 270 kfree_skb(skb); 271} 272 273static void pppol2tp_session_sock_hold(struct l2tp_session *session) 274{ 275 struct pppol2tp_session *ps = l2tp_session_priv(session); 276 277 if (ps->sock) 278 sock_hold(ps->sock); 279} 280 281static void pppol2tp_session_sock_put(struct l2tp_session *session) 282{ 283 struct pppol2tp_session *ps = l2tp_session_priv(session); 284 285 if (ps->sock) 286 sock_put(ps->sock); 287} 288 289/************************************************************************ 290 * Transmit handling 291 ***********************************************************************/ 292 293/* This is the sendmsg for the PPPoL2TP pppol2tp_session socket. We come here 294 * when a user application does a sendmsg() on the session socket. L2TP and 295 * PPP headers must be inserted into the user's data. 296 */ 297static int pppol2tp_sendmsg(struct socket *sock, struct msghdr *m, 298 size_t total_len) 299{ 300 static const unsigned char ppph[2] = { 0xff, 0x03 }; 301 struct sock *sk = sock->sk; 302 struct sk_buff *skb; 303 int error; 304 struct l2tp_session *session; 305 struct l2tp_tunnel *tunnel; 306 struct pppol2tp_session *ps; 307 int uhlen; 308 309 error = -ENOTCONN; 310 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) 311 goto error; 312 313 /* Get session and tunnel contexts */ 314 error = -EBADF; 315 session = pppol2tp_sock_to_session(sk); 316 if (session == NULL) 317 goto error; 318 319 ps = l2tp_session_priv(session); 320 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock); 321 if (tunnel == NULL) 322 goto error_put_sess; 323 324 uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; 325 326 /* Allocate a socket buffer */ 327 error = -ENOMEM; 328 skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) + 329 uhlen + session->hdr_len + 330 sizeof(ppph) + total_len, 331 0, GFP_KERNEL); 332 if (!skb) 333 goto error_put_sess_tun; 334 335 /* Reserve space for headers. */ 336 skb_reserve(skb, NET_SKB_PAD); 337 skb_reset_network_header(skb); 338 skb_reserve(skb, sizeof(struct iphdr)); 339 skb_reset_transport_header(skb); 340 skb_reserve(skb, uhlen); 341 342 /* Add PPP header */ 343 skb->data[0] = ppph[0]; 344 skb->data[1] = ppph[1]; 345 skb_put(skb, 2); 346 347 /* Copy user data into skb */ 348 error = memcpy_from_msg(skb_put(skb, total_len), m, total_len); 349 if (error < 0) { 350 kfree_skb(skb); 351 goto error_put_sess_tun; 352 } 353 354 local_bh_disable(); 355 l2tp_xmit_skb(session, skb, session->hdr_len); 356 local_bh_enable(); 357 358 sock_put(ps->tunnel_sock); 359 sock_put(sk); 360 361 return total_len; 362 363error_put_sess_tun: 364 sock_put(ps->tunnel_sock); 365error_put_sess: 366 sock_put(sk); 367error: 368 return error; 369} 370 371/* Transmit function called by generic PPP driver. Sends PPP frame 372 * over PPPoL2TP socket. 373 * 374 * This is almost the same as pppol2tp_sendmsg(), but rather than 375 * being called with a msghdr from userspace, it is called with a skb 376 * from the kernel. 377 * 378 * The supplied skb from ppp doesn't have enough headroom for the 379 * insertion of L2TP, UDP and IP headers so we need to allocate more 380 * headroom in the skb. This will create a cloned skb. But we must be 381 * careful in the error case because the caller will expect to free 382 * the skb it supplied, not our cloned skb. So we take care to always 383 * leave the original skb unfreed if we return an error. 384 */ 385static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb) 386{ 387 static const u8 ppph[2] = { 0xff, 0x03 }; 388 struct sock *sk = (struct sock *) chan->private; 389 struct sock *sk_tun; 390 struct l2tp_session *session; 391 struct l2tp_tunnel *tunnel; 392 struct pppol2tp_session *ps; 393 int uhlen, headroom; 394 395 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) 396 goto abort; 397 398 /* Get session and tunnel contexts from the socket */ 399 session = pppol2tp_sock_to_session(sk); 400 if (session == NULL) 401 goto abort; 402 403 ps = l2tp_session_priv(session); 404 sk_tun = ps->tunnel_sock; 405 if (sk_tun == NULL) 406 goto abort_put_sess; 407 tunnel = l2tp_sock_to_tunnel(sk_tun); 408 if (tunnel == NULL) 409 goto abort_put_sess; 410 411 uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; 412 headroom = NET_SKB_PAD + 413 sizeof(struct iphdr) + /* IP header */ 414 uhlen + /* UDP header (if L2TP_ENCAPTYPE_UDP) */ 415 session->hdr_len + /* L2TP header */ 416 sizeof(ppph); /* PPP header */ 417 if (skb_cow_head(skb, headroom)) 418 goto abort_put_sess_tun; 419 420 /* Setup PPP header */ 421 __skb_push(skb, sizeof(ppph)); 422 skb->data[0] = ppph[0]; 423 skb->data[1] = ppph[1]; 424 425 local_bh_disable(); 426 l2tp_xmit_skb(session, skb, session->hdr_len); 427 local_bh_enable(); 428 429 sock_put(sk_tun); 430 sock_put(sk); 431 return 1; 432 433abort_put_sess_tun: 434 sock_put(sk_tun); 435abort_put_sess: 436 sock_put(sk); 437abort: 438 /* Free the original skb */ 439 kfree_skb(skb); 440 return 1; 441} 442 443/***************************************************************************** 444 * Session (and tunnel control) socket create/destroy. 445 *****************************************************************************/ 446 447/* Called by l2tp_core when a session socket is being closed. 448 */ 449static void pppol2tp_session_close(struct l2tp_session *session) 450{ 451 struct pppol2tp_session *ps = l2tp_session_priv(session); 452 struct sock *sk = ps->sock; 453 struct socket *sock = sk->sk_socket; 454 455 BUG_ON(session->magic != L2TP_SESSION_MAGIC); 456 457 if (sock) { 458 inet_shutdown(sock, 2); 459 /* Don't let the session go away before our socket does */ 460 l2tp_session_inc_refcount(session); 461 } 462} 463 464/* Really kill the session socket. (Called from sock_put() if 465 * refcnt == 0.) 466 */ 467static void pppol2tp_session_destruct(struct sock *sk) 468{ 469 struct l2tp_session *session = sk->sk_user_data; 470 if (session) { 471 sk->sk_user_data = NULL; 472 BUG_ON(session->magic != L2TP_SESSION_MAGIC); 473 l2tp_session_dec_refcount(session); 474 } 475} 476 477/* Called when the PPPoX socket (session) is closed. 478 */ 479static int pppol2tp_release(struct socket *sock) 480{ 481 struct sock *sk = sock->sk; 482 struct l2tp_session *session; 483 int error; 484 485 if (!sk) 486 return 0; 487 488 error = -EBADF; 489 lock_sock(sk); 490 if (sock_flag(sk, SOCK_DEAD) != 0) 491 goto error; 492 493 pppox_unbind_sock(sk); 494 495 /* Signal the death of the socket. */ 496 sk->sk_state = PPPOX_DEAD; 497 sock_orphan(sk); 498 sock->sk = NULL; 499 500 session = pppol2tp_sock_to_session(sk); 501 502 /* Purge any queued data */ 503 if (session != NULL) { 504 __l2tp_session_unhash(session); 505 l2tp_session_queue_purge(session); 506 sock_put(sk); 507 } 508 skb_queue_purge(&sk->sk_receive_queue); 509 skb_queue_purge(&sk->sk_write_queue); 510 511 release_sock(sk); 512 513 /* This will delete the session context via 514 * pppol2tp_session_destruct() if the socket's refcnt drops to 515 * zero. 516 */ 517 sock_put(sk); 518 519 return 0; 520 521error: 522 release_sock(sk); 523 return error; 524} 525 526static struct proto pppol2tp_sk_proto = { 527 .name = "PPPOL2TP", 528 .owner = THIS_MODULE, 529 .obj_size = sizeof(struct pppox_sock), 530}; 531 532static int pppol2tp_backlog_recv(struct sock *sk, struct sk_buff *skb) 533{ 534 int rc; 535 536 rc = l2tp_udp_encap_recv(sk, skb); 537 if (rc) 538 kfree_skb(skb); 539 540 return NET_RX_SUCCESS; 541} 542 543/* socket() handler. Initialize a new struct sock. 544 */ 545static int pppol2tp_create(struct net *net, struct socket *sock) 546{ 547 int error = -ENOMEM; 548 struct sock *sk; 549 550 sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppol2tp_sk_proto); 551 if (!sk) 552 goto out; 553 554 sock_init_data(sock, sk); 555 556 sock->state = SS_UNCONNECTED; 557 sock->ops = &pppol2tp_ops; 558 559 sk->sk_backlog_rcv = pppol2tp_backlog_recv; 560 sk->sk_protocol = PX_PROTO_OL2TP; 561 sk->sk_family = PF_PPPOX; 562 sk->sk_state = PPPOX_NONE; 563 sk->sk_type = SOCK_STREAM; 564 sk->sk_destruct = pppol2tp_session_destruct; 565 566 error = 0; 567 568out: 569 return error; 570} 571 572#if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE) 573static void pppol2tp_show(struct seq_file *m, void *arg) 574{ 575 struct l2tp_session *session = arg; 576 struct pppol2tp_session *ps = l2tp_session_priv(session); 577 578 if (ps) { 579 struct pppox_sock *po = pppox_sk(ps->sock); 580 if (po) 581 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan)); 582 } 583} 584#endif 585 586/* connect() handler. Attach a PPPoX socket to a tunnel UDP socket 587 */ 588static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr, 589 int sockaddr_len, int flags) 590{ 591 struct sock *sk = sock->sk; 592 struct sockaddr_pppol2tp *sp = (struct sockaddr_pppol2tp *) uservaddr; 593 struct pppox_sock *po = pppox_sk(sk); 594 struct l2tp_session *session = NULL; 595 struct l2tp_tunnel *tunnel; 596 struct pppol2tp_session *ps; 597 struct dst_entry *dst; 598 struct l2tp_session_cfg cfg = { 0, }; 599 int error = 0; 600 u32 tunnel_id, peer_tunnel_id; 601 u32 session_id, peer_session_id; 602 int ver = 2; 603 int fd; 604 605 lock_sock(sk); 606 607 error = -EINVAL; 608 if (sp->sa_protocol != PX_PROTO_OL2TP) 609 goto end; 610 611 /* Check for already bound sockets */ 612 error = -EBUSY; 613 if (sk->sk_state & PPPOX_CONNECTED) 614 goto end; 615 616 /* We don't supporting rebinding anyway */ 617 error = -EALREADY; 618 if (sk->sk_user_data) 619 goto end; /* socket is already attached */ 620 621 /* Get params from socket address. Handle L2TPv2 and L2TPv3. 622 * This is nasty because there are different sockaddr_pppol2tp 623 * structs for L2TPv2, L2TPv3, over IPv4 and IPv6. We use 624 * the sockaddr size to determine which structure the caller 625 * is using. 626 */ 627 peer_tunnel_id = 0; 628 if (sockaddr_len == sizeof(struct sockaddr_pppol2tp)) { 629 fd = sp->pppol2tp.fd; 630 tunnel_id = sp->pppol2tp.s_tunnel; 631 peer_tunnel_id = sp->pppol2tp.d_tunnel; 632 session_id = sp->pppol2tp.s_session; 633 peer_session_id = sp->pppol2tp.d_session; 634 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpv3)) { 635 struct sockaddr_pppol2tpv3 *sp3 = 636 (struct sockaddr_pppol2tpv3 *) sp; 637 ver = 3; 638 fd = sp3->pppol2tp.fd; 639 tunnel_id = sp3->pppol2tp.s_tunnel; 640 peer_tunnel_id = sp3->pppol2tp.d_tunnel; 641 session_id = sp3->pppol2tp.s_session; 642 peer_session_id = sp3->pppol2tp.d_session; 643 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpin6)) { 644 struct sockaddr_pppol2tpin6 *sp6 = 645 (struct sockaddr_pppol2tpin6 *) sp; 646 fd = sp6->pppol2tp.fd; 647 tunnel_id = sp6->pppol2tp.s_tunnel; 648 peer_tunnel_id = sp6->pppol2tp.d_tunnel; 649 session_id = sp6->pppol2tp.s_session; 650 peer_session_id = sp6->pppol2tp.d_session; 651 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpv3in6)) { 652 struct sockaddr_pppol2tpv3in6 *sp6 = 653 (struct sockaddr_pppol2tpv3in6 *) sp; 654 ver = 3; 655 fd = sp6->pppol2tp.fd; 656 tunnel_id = sp6->pppol2tp.s_tunnel; 657 peer_tunnel_id = sp6->pppol2tp.d_tunnel; 658 session_id = sp6->pppol2tp.s_session; 659 peer_session_id = sp6->pppol2tp.d_session; 660 } else { 661 error = -EINVAL; 662 goto end; /* bad socket address */ 663 } 664 665 /* Don't bind if tunnel_id is 0 */ 666 error = -EINVAL; 667 if (tunnel_id == 0) 668 goto end; 669 670 tunnel = l2tp_tunnel_find(sock_net(sk), tunnel_id); 671 672 /* Special case: create tunnel context if session_id and 673 * peer_session_id is 0. Otherwise look up tunnel using supplied 674 * tunnel id. 675 */ 676 if ((session_id == 0) && (peer_session_id == 0)) { 677 if (tunnel == NULL) { 678 struct l2tp_tunnel_cfg tcfg = { 679 .encap = L2TP_ENCAPTYPE_UDP, 680 .debug = 0, 681 }; 682 error = l2tp_tunnel_create(sock_net(sk), fd, ver, tunnel_id, peer_tunnel_id, &tcfg, &tunnel); 683 if (error < 0) 684 goto end; 685 } 686 } else { 687 /* Error if we can't find the tunnel */ 688 error = -ENOENT; 689 if (tunnel == NULL) 690 goto end; 691 692 /* Error if socket is not prepped */ 693 if (tunnel->sock == NULL) 694 goto end; 695 } 696 697 if (tunnel->recv_payload_hook == NULL) 698 tunnel->recv_payload_hook = pppol2tp_recv_payload_hook; 699 700 if (tunnel->peer_tunnel_id == 0) 701 tunnel->peer_tunnel_id = peer_tunnel_id; 702 703 /* Create session if it doesn't already exist. We handle the 704 * case where a session was previously created by the netlink 705 * interface by checking that the session doesn't already have 706 * a socket and its tunnel socket are what we expect. If any 707 * of those checks fail, return EEXIST to the caller. 708 */ 709 session = l2tp_session_find(sock_net(sk), tunnel, session_id); 710 if (session == NULL) { 711 /* Default MTU must allow space for UDP/L2TP/PPP 712 * headers. 713 */ 714 cfg.mtu = cfg.mru = 1500 - PPPOL2TP_HEADER_OVERHEAD; 715 716 /* Allocate and initialize a new session context. */ 717 session = l2tp_session_create(sizeof(struct pppol2tp_session), 718 tunnel, session_id, 719 peer_session_id, &cfg); 720 if (session == NULL) { 721 error = -ENOMEM; 722 goto end; 723 } 724 } else { 725 ps = l2tp_session_priv(session); 726 error = -EEXIST; 727 if (ps->sock != NULL) 728 goto end; 729 730 /* consistency checks */ 731 if (ps->tunnel_sock != tunnel->sock) 732 goto end; 733 } 734 735 /* Associate session with its PPPoL2TP socket */ 736 ps = l2tp_session_priv(session); 737 ps->owner = current->pid; 738 ps->sock = sk; 739 ps->tunnel_sock = tunnel->sock; 740 741 session->recv_skb = pppol2tp_recv; 742 session->session_close = pppol2tp_session_close; 743#if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE) 744 session->show = pppol2tp_show; 745#endif 746 747 /* We need to know each time a skb is dropped from the reorder 748 * queue. 749 */ 750 session->ref = pppol2tp_session_sock_hold; 751 session->deref = pppol2tp_session_sock_put; 752 753 /* If PMTU discovery was enabled, use the MTU that was discovered */ 754 dst = sk_dst_get(tunnel->sock); 755 if (dst != NULL) { 756 u32 pmtu = dst_mtu(dst); 757 758 if (pmtu != 0) 759 session->mtu = session->mru = pmtu - 760 PPPOL2TP_HEADER_OVERHEAD; 761 dst_release(dst); 762 } 763 764 /* Special case: if source & dest session_id == 0x0000, this 765 * socket is being created to manage the tunnel. Just set up 766 * the internal context for use by ioctl() and sockopt() 767 * handlers. 768 */ 769 if ((session->session_id == 0) && 770 (session->peer_session_id == 0)) { 771 error = 0; 772 goto out_no_ppp; 773 } 774 775 /* The only header we need to worry about is the L2TP 776 * header. This size is different depending on whether 777 * sequence numbers are enabled for the data channel. 778 */ 779 po->chan.hdrlen = PPPOL2TP_L2TP_HDR_SIZE_NOSEQ; 780 781 po->chan.private = sk; 782 po->chan.ops = &pppol2tp_chan_ops; 783 po->chan.mtu = session->mtu; 784 785 error = ppp_register_net_channel(sock_net(sk), &po->chan); 786 if (error) 787 goto end; 788 789out_no_ppp: 790 /* This is how we get the session context from the socket. */ 791 sk->sk_user_data = session; 792 sk->sk_state = PPPOX_CONNECTED; 793 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: created\n", 794 session->name); 795 796end: 797 release_sock(sk); 798 799 return error; 800} 801 802#ifdef CONFIG_L2TP_V3 803 804/* Called when creating sessions via the netlink interface. 805 */ 806static int pppol2tp_session_create(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg) 807{ 808 int error; 809 struct l2tp_tunnel *tunnel; 810 struct l2tp_session *session; 811 struct pppol2tp_session *ps; 812 813 tunnel = l2tp_tunnel_find(net, tunnel_id); 814 815 /* Error if we can't find the tunnel */ 816 error = -ENOENT; 817 if (tunnel == NULL) 818 goto out; 819 820 /* Error if tunnel socket is not prepped */ 821 if (tunnel->sock == NULL) 822 goto out; 823 824 /* Check that this session doesn't already exist */ 825 error = -EEXIST; 826 session = l2tp_session_find(net, tunnel, session_id); 827 if (session != NULL) 828 goto out; 829 830 /* Default MTU values. */ 831 if (cfg->mtu == 0) 832 cfg->mtu = 1500 - PPPOL2TP_HEADER_OVERHEAD; 833 if (cfg->mru == 0) 834 cfg->mru = cfg->mtu; 835 836 /* Allocate and initialize a new session context. */ 837 error = -ENOMEM; 838 session = l2tp_session_create(sizeof(struct pppol2tp_session), 839 tunnel, session_id, 840 peer_session_id, cfg); 841 if (session == NULL) 842 goto out; 843 844 ps = l2tp_session_priv(session); 845 ps->tunnel_sock = tunnel->sock; 846 847 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: created\n", 848 session->name); 849 850 error = 0; 851 852out: 853 return error; 854} 855 856#endif /* CONFIG_L2TP_V3 */ 857 858/* getname() support. 859 */ 860static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr, 861 int *usockaddr_len, int peer) 862{ 863 int len = 0; 864 int error = 0; 865 struct l2tp_session *session; 866 struct l2tp_tunnel *tunnel; 867 struct sock *sk = sock->sk; 868 struct inet_sock *inet; 869 struct pppol2tp_session *pls; 870 871 error = -ENOTCONN; 872 if (sk == NULL) 873 goto end; 874 if (sk->sk_state != PPPOX_CONNECTED) 875 goto end; 876 877 error = -EBADF; 878 session = pppol2tp_sock_to_session(sk); 879 if (session == NULL) 880 goto end; 881 882 pls = l2tp_session_priv(session); 883 tunnel = l2tp_sock_to_tunnel(pls->tunnel_sock); 884 if (tunnel == NULL) { 885 error = -EBADF; 886 goto end_put_sess; 887 } 888 889 inet = inet_sk(tunnel->sock); 890 if ((tunnel->version == 2) && (tunnel->sock->sk_family == AF_INET)) { 891 struct sockaddr_pppol2tp sp; 892 len = sizeof(sp); 893 memset(&sp, 0, len); 894 sp.sa_family = AF_PPPOX; 895 sp.sa_protocol = PX_PROTO_OL2TP; 896 sp.pppol2tp.fd = tunnel->fd; 897 sp.pppol2tp.pid = pls->owner; 898 sp.pppol2tp.s_tunnel = tunnel->tunnel_id; 899 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id; 900 sp.pppol2tp.s_session = session->session_id; 901 sp.pppol2tp.d_session = session->peer_session_id; 902 sp.pppol2tp.addr.sin_family = AF_INET; 903 sp.pppol2tp.addr.sin_port = inet->inet_dport; 904 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr; 905 memcpy(uaddr, &sp, len); 906#if IS_ENABLED(CONFIG_IPV6) 907 } else if ((tunnel->version == 2) && 908 (tunnel->sock->sk_family == AF_INET6)) { 909 struct sockaddr_pppol2tpin6 sp; 910 911 len = sizeof(sp); 912 memset(&sp, 0, len); 913 sp.sa_family = AF_PPPOX; 914 sp.sa_protocol = PX_PROTO_OL2TP; 915 sp.pppol2tp.fd = tunnel->fd; 916 sp.pppol2tp.pid = pls->owner; 917 sp.pppol2tp.s_tunnel = tunnel->tunnel_id; 918 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id; 919 sp.pppol2tp.s_session = session->session_id; 920 sp.pppol2tp.d_session = session->peer_session_id; 921 sp.pppol2tp.addr.sin6_family = AF_INET6; 922 sp.pppol2tp.addr.sin6_port = inet->inet_dport; 923 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr, 924 sizeof(tunnel->sock->sk_v6_daddr)); 925 memcpy(uaddr, &sp, len); 926 } else if ((tunnel->version == 3) && 927 (tunnel->sock->sk_family == AF_INET6)) { 928 struct sockaddr_pppol2tpv3in6 sp; 929 930 len = sizeof(sp); 931 memset(&sp, 0, len); 932 sp.sa_family = AF_PPPOX; 933 sp.sa_protocol = PX_PROTO_OL2TP; 934 sp.pppol2tp.fd = tunnel->fd; 935 sp.pppol2tp.pid = pls->owner; 936 sp.pppol2tp.s_tunnel = tunnel->tunnel_id; 937 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id; 938 sp.pppol2tp.s_session = session->session_id; 939 sp.pppol2tp.d_session = session->peer_session_id; 940 sp.pppol2tp.addr.sin6_family = AF_INET6; 941 sp.pppol2tp.addr.sin6_port = inet->inet_dport; 942 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr, 943 sizeof(tunnel->sock->sk_v6_daddr)); 944 memcpy(uaddr, &sp, len); 945#endif 946 } else if (tunnel->version == 3) { 947 struct sockaddr_pppol2tpv3 sp; 948 len = sizeof(sp); 949 memset(&sp, 0, len); 950 sp.sa_family = AF_PPPOX; 951 sp.sa_protocol = PX_PROTO_OL2TP; 952 sp.pppol2tp.fd = tunnel->fd; 953 sp.pppol2tp.pid = pls->owner; 954 sp.pppol2tp.s_tunnel = tunnel->tunnel_id; 955 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id; 956 sp.pppol2tp.s_session = session->session_id; 957 sp.pppol2tp.d_session = session->peer_session_id; 958 sp.pppol2tp.addr.sin_family = AF_INET; 959 sp.pppol2tp.addr.sin_port = inet->inet_dport; 960 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr; 961 memcpy(uaddr, &sp, len); 962 } 963 964 *usockaddr_len = len; 965 966 sock_put(pls->tunnel_sock); 967end_put_sess: 968 sock_put(sk); 969 error = 0; 970 971end: 972 return error; 973} 974 975/**************************************************************************** 976 * ioctl() handlers. 977 * 978 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP 979 * sockets. However, in order to control kernel tunnel features, we allow 980 * userspace to create a special "tunnel" PPPoX socket which is used for 981 * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow 982 * the user application to issue L2TP setsockopt(), getsockopt() and ioctl() 983 * calls. 984 ****************************************************************************/ 985 986static void pppol2tp_copy_stats(struct pppol2tp_ioc_stats *dest, 987 struct l2tp_stats *stats) 988{ 989 dest->tx_packets = atomic_long_read(&stats->tx_packets); 990 dest->tx_bytes = atomic_long_read(&stats->tx_bytes); 991 dest->tx_errors = atomic_long_read(&stats->tx_errors); 992 dest->rx_packets = atomic_long_read(&stats->rx_packets); 993 dest->rx_bytes = atomic_long_read(&stats->rx_bytes); 994 dest->rx_seq_discards = atomic_long_read(&stats->rx_seq_discards); 995 dest->rx_oos_packets = atomic_long_read(&stats->rx_oos_packets); 996 dest->rx_errors = atomic_long_read(&stats->rx_errors); 997} 998 999/* Session ioctl helper. 1000 */ 1001static int pppol2tp_session_ioctl(struct l2tp_session *session, 1002 unsigned int cmd, unsigned long arg) 1003{ 1004 struct ifreq ifr; 1005 int err = 0; 1006 struct sock *sk; 1007 int val = (int) arg; 1008 struct pppol2tp_session *ps = l2tp_session_priv(session); 1009 struct l2tp_tunnel *tunnel = session->tunnel; 1010 struct pppol2tp_ioc_stats stats; 1011 1012 l2tp_dbg(session, PPPOL2TP_MSG_CONTROL, 1013 "%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n", 1014 session->name, cmd, arg); 1015 1016 sk = ps->sock; 1017 sock_hold(sk); 1018 1019 switch (cmd) { 1020 case SIOCGIFMTU: 1021 err = -ENXIO; 1022 if (!(sk->sk_state & PPPOX_CONNECTED)) 1023 break; 1024 1025 err = -EFAULT; 1026 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq))) 1027 break; 1028 ifr.ifr_mtu = session->mtu; 1029 if (copy_to_user((void __user *) arg, &ifr, sizeof(struct ifreq))) 1030 break; 1031 1032 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get mtu=%d\n", 1033 session->name, session->mtu); 1034 err = 0; 1035 break; 1036 1037 case SIOCSIFMTU: 1038 err = -ENXIO; 1039 if (!(sk->sk_state & PPPOX_CONNECTED)) 1040 break; 1041 1042 err = -EFAULT; 1043 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq))) 1044 break; 1045 1046 session->mtu = ifr.ifr_mtu; 1047 1048 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set mtu=%d\n", 1049 session->name, session->mtu); 1050 err = 0; 1051 break; 1052 1053 case PPPIOCGMRU: 1054 err = -ENXIO; 1055 if (!(sk->sk_state & PPPOX_CONNECTED)) 1056 break; 1057 1058 err = -EFAULT; 1059 if (put_user(session->mru, (int __user *) arg)) 1060 break; 1061 1062 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get mru=%d\n", 1063 session->name, session->mru); 1064 err = 0; 1065 break; 1066 1067 case PPPIOCSMRU: 1068 err = -ENXIO; 1069 if (!(sk->sk_state & PPPOX_CONNECTED)) 1070 break; 1071 1072 err = -EFAULT; 1073 if (get_user(val, (int __user *) arg)) 1074 break; 1075 1076 session->mru = val; 1077 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set mru=%d\n", 1078 session->name, session->mru); 1079 err = 0; 1080 break; 1081 1082 case PPPIOCGFLAGS: 1083 err = -EFAULT; 1084 if (put_user(ps->flags, (int __user *) arg)) 1085 break; 1086 1087 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get flags=%d\n", 1088 session->name, ps->flags); 1089 err = 0; 1090 break; 1091 1092 case PPPIOCSFLAGS: 1093 err = -EFAULT; 1094 if (get_user(val, (int __user *) arg)) 1095 break; 1096 ps->flags = val; 1097 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set flags=%d\n", 1098 session->name, ps->flags); 1099 err = 0; 1100 break; 1101 1102 case PPPIOCGL2TPSTATS: 1103 err = -ENXIO; 1104 if (!(sk->sk_state & PPPOX_CONNECTED)) 1105 break; 1106 1107 memset(&stats, 0, sizeof(stats)); 1108 stats.tunnel_id = tunnel->tunnel_id; 1109 stats.session_id = session->session_id; 1110 pppol2tp_copy_stats(&stats, &session->stats); 1111 if (copy_to_user((void __user *) arg, &stats, 1112 sizeof(stats))) 1113 break; 1114 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get L2TP stats\n", 1115 session->name); 1116 err = 0; 1117 break; 1118 1119 default: 1120 err = -ENOSYS; 1121 break; 1122 } 1123 1124 sock_put(sk); 1125 1126 return err; 1127} 1128 1129/* Tunnel ioctl helper. 1130 * 1131 * Note the special handling for PPPIOCGL2TPSTATS below. If the ioctl data 1132 * specifies a session_id, the session ioctl handler is called. This allows an 1133 * application to retrieve session stats via a tunnel socket. 1134 */ 1135static int pppol2tp_tunnel_ioctl(struct l2tp_tunnel *tunnel, 1136 unsigned int cmd, unsigned long arg) 1137{ 1138 int err = 0; 1139 struct sock *sk; 1140 struct pppol2tp_ioc_stats stats; 1141 1142 l2tp_dbg(tunnel, PPPOL2TP_MSG_CONTROL, 1143 "%s: pppol2tp_tunnel_ioctl(cmd=%#x, arg=%#lx)\n", 1144 tunnel->name, cmd, arg); 1145 1146 sk = tunnel->sock; 1147 sock_hold(sk); 1148 1149 switch (cmd) { 1150 case PPPIOCGL2TPSTATS: 1151 err = -ENXIO; 1152 if (!(sk->sk_state & PPPOX_CONNECTED)) 1153 break; 1154 1155 if (copy_from_user(&stats, (void __user *) arg, 1156 sizeof(stats))) { 1157 err = -EFAULT; 1158 break; 1159 } 1160 if (stats.session_id != 0) { 1161 /* resend to session ioctl handler */ 1162 struct l2tp_session *session = 1163 l2tp_session_find(sock_net(sk), tunnel, stats.session_id); 1164 if (session != NULL) 1165 err = pppol2tp_session_ioctl(session, cmd, arg); 1166 else 1167 err = -EBADR; 1168 break; 1169 } 1170#ifdef CONFIG_XFRM 1171 stats.using_ipsec = (sk->sk_policy[0] || sk->sk_policy[1]) ? 1 : 0; 1172#endif 1173 pppol2tp_copy_stats(&stats, &tunnel->stats); 1174 if (copy_to_user((void __user *) arg, &stats, sizeof(stats))) { 1175 err = -EFAULT; 1176 break; 1177 } 1178 l2tp_info(tunnel, PPPOL2TP_MSG_CONTROL, "%s: get L2TP stats\n", 1179 tunnel->name); 1180 err = 0; 1181 break; 1182 1183 default: 1184 err = -ENOSYS; 1185 break; 1186 } 1187 1188 sock_put(sk); 1189 1190 return err; 1191} 1192 1193/* Main ioctl() handler. 1194 * Dispatch to tunnel or session helpers depending on the socket. 1195 */ 1196static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd, 1197 unsigned long arg) 1198{ 1199 struct sock *sk = sock->sk; 1200 struct l2tp_session *session; 1201 struct l2tp_tunnel *tunnel; 1202 struct pppol2tp_session *ps; 1203 int err; 1204 1205 if (!sk) 1206 return 0; 1207 1208 err = -EBADF; 1209 if (sock_flag(sk, SOCK_DEAD) != 0) 1210 goto end; 1211 1212 err = -ENOTCONN; 1213 if ((sk->sk_user_data == NULL) || 1214 (!(sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND)))) 1215 goto end; 1216 1217 /* Get session context from the socket */ 1218 err = -EBADF; 1219 session = pppol2tp_sock_to_session(sk); 1220 if (session == NULL) 1221 goto end; 1222 1223 /* Special case: if session's session_id is zero, treat ioctl as a 1224 * tunnel ioctl 1225 */ 1226 ps = l2tp_session_priv(session); 1227 if ((session->session_id == 0) && 1228 (session->peer_session_id == 0)) { 1229 err = -EBADF; 1230 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock); 1231 if (tunnel == NULL) 1232 goto end_put_sess; 1233 1234 err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg); 1235 sock_put(ps->tunnel_sock); 1236 goto end_put_sess; 1237 } 1238 1239 err = pppol2tp_session_ioctl(session, cmd, arg); 1240 1241end_put_sess: 1242 sock_put(sk); 1243end: 1244 return err; 1245} 1246 1247/***************************************************************************** 1248 * setsockopt() / getsockopt() support. 1249 * 1250 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP 1251 * sockets. In order to control kernel tunnel features, we allow userspace to 1252 * create a special "tunnel" PPPoX socket which is used for control only. 1253 * Tunnel PPPoX sockets have session_id == 0 and simply allow the user 1254 * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls. 1255 *****************************************************************************/ 1256 1257/* Tunnel setsockopt() helper. 1258 */ 1259static int pppol2tp_tunnel_setsockopt(struct sock *sk, 1260 struct l2tp_tunnel *tunnel, 1261 int optname, int val) 1262{ 1263 int err = 0; 1264 1265 switch (optname) { 1266 case PPPOL2TP_SO_DEBUG: 1267 tunnel->debug = val; 1268 l2tp_info(tunnel, PPPOL2TP_MSG_CONTROL, "%s: set debug=%x\n", 1269 tunnel->name, tunnel->debug); 1270 break; 1271 1272 default: 1273 err = -ENOPROTOOPT; 1274 break; 1275 } 1276 1277 return err; 1278} 1279 1280/* Session setsockopt helper. 1281 */ 1282static int pppol2tp_session_setsockopt(struct sock *sk, 1283 struct l2tp_session *session, 1284 int optname, int val) 1285{ 1286 int err = 0; 1287 struct pppol2tp_session *ps = l2tp_session_priv(session); 1288 1289 switch (optname) { 1290 case PPPOL2TP_SO_RECVSEQ: 1291 if ((val != 0) && (val != 1)) { 1292 err = -EINVAL; 1293 break; 1294 } 1295 session->recv_seq = val ? -1 : 0; 1296 l2tp_info(session, PPPOL2TP_MSG_CONTROL, 1297 "%s: set recv_seq=%d\n", 1298 session->name, session->recv_seq); 1299 break; 1300 1301 case PPPOL2TP_SO_SENDSEQ: 1302 if ((val != 0) && (val != 1)) { 1303 err = -EINVAL; 1304 break; 1305 } 1306 session->send_seq = val ? -1 : 0; 1307 { 1308 struct sock *ssk = ps->sock; 1309 struct pppox_sock *po = pppox_sk(ssk); 1310 po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ : 1311 PPPOL2TP_L2TP_HDR_SIZE_NOSEQ; 1312 } 1313 l2tp_session_set_header_len(session, session->tunnel->version); 1314 l2tp_info(session, PPPOL2TP_MSG_CONTROL, 1315 "%s: set send_seq=%d\n", 1316 session->name, session->send_seq); 1317 break; 1318 1319 case PPPOL2TP_SO_LNSMODE: 1320 if ((val != 0) && (val != 1)) { 1321 err = -EINVAL; 1322 break; 1323 } 1324 session->lns_mode = val ? -1 : 0; 1325 l2tp_info(session, PPPOL2TP_MSG_CONTROL, 1326 "%s: set lns_mode=%d\n", 1327 session->name, session->lns_mode); 1328 break; 1329 1330 case PPPOL2TP_SO_DEBUG: 1331 session->debug = val; 1332 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set debug=%x\n", 1333 session->name, session->debug); 1334 break; 1335 1336 case PPPOL2TP_SO_REORDERTO: 1337 session->reorder_timeout = msecs_to_jiffies(val); 1338 l2tp_info(session, PPPOL2TP_MSG_CONTROL, 1339 "%s: set reorder_timeout=%d\n", 1340 session->name, session->reorder_timeout); 1341 break; 1342 1343 default: 1344 err = -ENOPROTOOPT; 1345 break; 1346 } 1347 1348 return err; 1349} 1350 1351/* Main setsockopt() entry point. 1352 * Does API checks, then calls either the tunnel or session setsockopt 1353 * handler, according to whether the PPPoL2TP socket is a for a regular 1354 * session or the special tunnel type. 1355 */ 1356static int pppol2tp_setsockopt(struct socket *sock, int level, int optname, 1357 char __user *optval, unsigned int optlen) 1358{ 1359 struct sock *sk = sock->sk; 1360 struct l2tp_session *session; 1361 struct l2tp_tunnel *tunnel; 1362 struct pppol2tp_session *ps; 1363 int val; 1364 int err; 1365 1366 if (level != SOL_PPPOL2TP) 1367 return -EINVAL; 1368 1369 if (optlen < sizeof(int)) 1370 return -EINVAL; 1371 1372 if (get_user(val, (int __user *)optval)) 1373 return -EFAULT; 1374 1375 err = -ENOTCONN; 1376 if (sk->sk_user_data == NULL) 1377 goto end; 1378 1379 /* Get session context from the socket */ 1380 err = -EBADF; 1381 session = pppol2tp_sock_to_session(sk); 1382 if (session == NULL) 1383 goto end; 1384 1385 /* Special case: if session_id == 0x0000, treat as operation on tunnel 1386 */ 1387 ps = l2tp_session_priv(session); 1388 if ((session->session_id == 0) && 1389 (session->peer_session_id == 0)) { 1390 err = -EBADF; 1391 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock); 1392 if (tunnel == NULL) 1393 goto end_put_sess; 1394 1395 err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val); 1396 sock_put(ps->tunnel_sock); 1397 } else 1398 err = pppol2tp_session_setsockopt(sk, session, optname, val); 1399 1400 err = 0; 1401 1402end_put_sess: 1403 sock_put(sk); 1404end: 1405 return err; 1406} 1407 1408/* Tunnel getsockopt helper. Called with sock locked. 1409 */ 1410static int pppol2tp_tunnel_getsockopt(struct sock *sk, 1411 struct l2tp_tunnel *tunnel, 1412 int optname, int *val) 1413{ 1414 int err = 0; 1415 1416 switch (optname) { 1417 case PPPOL2TP_SO_DEBUG: 1418 *val = tunnel->debug; 1419 l2tp_info(tunnel, PPPOL2TP_MSG_CONTROL, "%s: get debug=%x\n", 1420 tunnel->name, tunnel->debug); 1421 break; 1422 1423 default: 1424 err = -ENOPROTOOPT; 1425 break; 1426 } 1427 1428 return err; 1429} 1430 1431/* Session getsockopt helper. Called with sock locked. 1432 */ 1433static int pppol2tp_session_getsockopt(struct sock *sk, 1434 struct l2tp_session *session, 1435 int optname, int *val) 1436{ 1437 int err = 0; 1438 1439 switch (optname) { 1440 case PPPOL2TP_SO_RECVSEQ: 1441 *val = session->recv_seq; 1442 l2tp_info(session, PPPOL2TP_MSG_CONTROL, 1443 "%s: get recv_seq=%d\n", session->name, *val); 1444 break; 1445 1446 case PPPOL2TP_SO_SENDSEQ: 1447 *val = session->send_seq; 1448 l2tp_info(session, PPPOL2TP_MSG_CONTROL, 1449 "%s: get send_seq=%d\n", session->name, *val); 1450 break; 1451 1452 case PPPOL2TP_SO_LNSMODE: 1453 *val = session->lns_mode; 1454 l2tp_info(session, PPPOL2TP_MSG_CONTROL, 1455 "%s: get lns_mode=%d\n", session->name, *val); 1456 break; 1457 1458 case PPPOL2TP_SO_DEBUG: 1459 *val = session->debug; 1460 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get debug=%d\n", 1461 session->name, *val); 1462 break; 1463 1464 case PPPOL2TP_SO_REORDERTO: 1465 *val = (int) jiffies_to_msecs(session->reorder_timeout); 1466 l2tp_info(session, PPPOL2TP_MSG_CONTROL, 1467 "%s: get reorder_timeout=%d\n", session->name, *val); 1468 break; 1469 1470 default: 1471 err = -ENOPROTOOPT; 1472 } 1473 1474 return err; 1475} 1476 1477/* Main getsockopt() entry point. 1478 * Does API checks, then calls either the tunnel or session getsockopt 1479 * handler, according to whether the PPPoX socket is a for a regular session 1480 * or the special tunnel type. 1481 */ 1482static int pppol2tp_getsockopt(struct socket *sock, int level, int optname, 1483 char __user *optval, int __user *optlen) 1484{ 1485 struct sock *sk = sock->sk; 1486 struct l2tp_session *session; 1487 struct l2tp_tunnel *tunnel; 1488 int val, len; 1489 int err; 1490 struct pppol2tp_session *ps; 1491 1492 if (level != SOL_PPPOL2TP) 1493 return -EINVAL; 1494 1495 if (get_user(len, optlen)) 1496 return -EFAULT; 1497 1498 len = min_t(unsigned int, len, sizeof(int)); 1499 1500 if (len < 0) 1501 return -EINVAL; 1502 1503 err = -ENOTCONN; 1504 if (sk->sk_user_data == NULL) 1505 goto end; 1506 1507 /* Get the session context */ 1508 err = -EBADF; 1509 session = pppol2tp_sock_to_session(sk); 1510 if (session == NULL) 1511 goto end; 1512 1513 /* Special case: if session_id == 0x0000, treat as operation on tunnel */ 1514 ps = l2tp_session_priv(session); 1515 if ((session->session_id == 0) && 1516 (session->peer_session_id == 0)) { 1517 err = -EBADF; 1518 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock); 1519 if (tunnel == NULL) 1520 goto end_put_sess; 1521 1522 err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val); 1523 sock_put(ps->tunnel_sock); 1524 } else 1525 err = pppol2tp_session_getsockopt(sk, session, optname, &val); 1526 1527 err = -EFAULT; 1528 if (put_user(len, optlen)) 1529 goto end_put_sess; 1530 1531 if (copy_to_user((void __user *) optval, &val, len)) 1532 goto end_put_sess; 1533 1534 err = 0; 1535 1536end_put_sess: 1537 sock_put(sk); 1538end: 1539 return err; 1540} 1541 1542/***************************************************************************** 1543 * /proc filesystem for debug 1544 * Since the original pppol2tp driver provided /proc/net/pppol2tp for 1545 * L2TPv2, we dump only L2TPv2 tunnels and sessions here. 1546 *****************************************************************************/ 1547 1548static unsigned int pppol2tp_net_id; 1549 1550#ifdef CONFIG_PROC_FS 1551 1552struct pppol2tp_seq_data { 1553 struct seq_net_private p; 1554 int tunnel_idx; /* current tunnel */ 1555 int session_idx; /* index of session within current tunnel */ 1556 struct l2tp_tunnel *tunnel; 1557 struct l2tp_session *session; /* NULL means get next tunnel */ 1558}; 1559 1560static void pppol2tp_next_tunnel(struct net *net, struct pppol2tp_seq_data *pd) 1561{ 1562 for (;;) { 1563 pd->tunnel = l2tp_tunnel_find_nth(net, pd->tunnel_idx); 1564 pd->tunnel_idx++; 1565 1566 if (pd->tunnel == NULL) 1567 break; 1568 1569 /* Ignore L2TPv3 tunnels */ 1570 if (pd->tunnel->version < 3) 1571 break; 1572 } 1573} 1574 1575static void pppol2tp_next_session(struct net *net, struct pppol2tp_seq_data *pd) 1576{ 1577 pd->session = l2tp_session_find_nth(pd->tunnel, pd->session_idx); 1578 pd->session_idx++; 1579 1580 if (pd->session == NULL) { 1581 pd->session_idx = 0; 1582 pppol2tp_next_tunnel(net, pd); 1583 } 1584} 1585 1586static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs) 1587{ 1588 struct pppol2tp_seq_data *pd = SEQ_START_TOKEN; 1589 loff_t pos = *offs; 1590 struct net *net; 1591 1592 if (!pos) 1593 goto out; 1594 1595 BUG_ON(m->private == NULL); 1596 pd = m->private; 1597 net = seq_file_net(m); 1598 1599 if (pd->tunnel == NULL) 1600 pppol2tp_next_tunnel(net, pd); 1601 else 1602 pppol2tp_next_session(net, pd); 1603 1604 /* NULL tunnel and session indicates end of list */ 1605 if ((pd->tunnel == NULL) && (pd->session == NULL)) 1606 pd = NULL; 1607 1608out: 1609 return pd; 1610} 1611 1612static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos) 1613{ 1614 (*pos)++; 1615 return NULL; 1616} 1617 1618static void pppol2tp_seq_stop(struct seq_file *p, void *v) 1619{ 1620 /* nothing to do */ 1621} 1622 1623static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v) 1624{ 1625 struct l2tp_tunnel *tunnel = v; 1626 1627 seq_printf(m, "\nTUNNEL '%s', %c %d\n", 1628 tunnel->name, 1629 (tunnel == tunnel->sock->sk_user_data) ? 'Y' : 'N', 1630 atomic_read(&tunnel->ref_count) - 1); 1631 seq_printf(m, " %08x %ld/%ld/%ld %ld/%ld/%ld\n", 1632 tunnel->debug, 1633 atomic_long_read(&tunnel->stats.tx_packets), 1634 atomic_long_read(&tunnel->stats.tx_bytes), 1635 atomic_long_read(&tunnel->stats.tx_errors), 1636 atomic_long_read(&tunnel->stats.rx_packets), 1637 atomic_long_read(&tunnel->stats.rx_bytes), 1638 atomic_long_read(&tunnel->stats.rx_errors)); 1639} 1640 1641static void pppol2tp_seq_session_show(struct seq_file *m, void *v) 1642{ 1643 struct l2tp_session *session = v; 1644 struct l2tp_tunnel *tunnel = session->tunnel; 1645 struct pppol2tp_session *ps = l2tp_session_priv(session); 1646 struct pppox_sock *po = pppox_sk(ps->sock); 1647 u32 ip = 0; 1648 u16 port = 0; 1649 1650 if (tunnel->sock) { 1651 struct inet_sock *inet = inet_sk(tunnel->sock); 1652 ip = ntohl(inet->inet_saddr); 1653 port = ntohs(inet->inet_sport); 1654 } 1655 1656 seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> " 1657 "%04X/%04X %d %c\n", 1658 session->name, ip, port, 1659 tunnel->tunnel_id, 1660 session->session_id, 1661 tunnel->peer_tunnel_id, 1662 session->peer_session_id, 1663 ps->sock->sk_state, 1664 (session == ps->sock->sk_user_data) ? 1665 'Y' : 'N'); 1666 seq_printf(m, " %d/%d/%c/%c/%s %08x %u\n", 1667 session->mtu, session->mru, 1668 session->recv_seq ? 'R' : '-', 1669 session->send_seq ? 'S' : '-', 1670 session->lns_mode ? "LNS" : "LAC", 1671 session->debug, 1672 jiffies_to_msecs(session->reorder_timeout)); 1673 seq_printf(m, " %hu/%hu %ld/%ld/%ld %ld/%ld/%ld\n", 1674 session->nr, session->ns, 1675 atomic_long_read(&session->stats.tx_packets), 1676 atomic_long_read(&session->stats.tx_bytes), 1677 atomic_long_read(&session->stats.tx_errors), 1678 atomic_long_read(&session->stats.rx_packets), 1679 atomic_long_read(&session->stats.rx_bytes), 1680 atomic_long_read(&session->stats.rx_errors)); 1681 1682 if (po) 1683 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan)); 1684} 1685 1686static int pppol2tp_seq_show(struct seq_file *m, void *v) 1687{ 1688 struct pppol2tp_seq_data *pd = v; 1689 1690 /* display header on line 1 */ 1691 if (v == SEQ_START_TOKEN) { 1692 seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n"); 1693 seq_puts(m, "TUNNEL name, user-data-ok session-count\n"); 1694 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); 1695 seq_puts(m, " SESSION name, addr/port src-tid/sid " 1696 "dest-tid/sid state user-data-ok\n"); 1697 seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n"); 1698 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); 1699 goto out; 1700 } 1701 1702 /* Show the tunnel or session context. 1703 */ 1704 if (pd->session == NULL) 1705 pppol2tp_seq_tunnel_show(m, pd->tunnel); 1706 else 1707 pppol2tp_seq_session_show(m, pd->session); 1708 1709out: 1710 return 0; 1711} 1712 1713static const struct seq_operations pppol2tp_seq_ops = { 1714 .start = pppol2tp_seq_start, 1715 .next = pppol2tp_seq_next, 1716 .stop = pppol2tp_seq_stop, 1717 .show = pppol2tp_seq_show, 1718}; 1719 1720/* Called when our /proc file is opened. We allocate data for use when 1721 * iterating our tunnel / session contexts and store it in the private 1722 * data of the seq_file. 1723 */ 1724static int pppol2tp_proc_open(struct inode *inode, struct file *file) 1725{ 1726 return seq_open_net(inode, file, &pppol2tp_seq_ops, 1727 sizeof(struct pppol2tp_seq_data)); 1728} 1729 1730static const struct file_operations pppol2tp_proc_fops = { 1731 .owner = THIS_MODULE, 1732 .open = pppol2tp_proc_open, 1733 .read = seq_read, 1734 .llseek = seq_lseek, 1735 .release = seq_release_net, 1736}; 1737 1738#endif /* CONFIG_PROC_FS */ 1739 1740/***************************************************************************** 1741 * Network namespace 1742 *****************************************************************************/ 1743 1744static __net_init int pppol2tp_init_net(struct net *net) 1745{ 1746 struct proc_dir_entry *pde; 1747 int err = 0; 1748 1749 pde = proc_create("pppol2tp", S_IRUGO, net->proc_net, 1750 &pppol2tp_proc_fops); 1751 if (!pde) { 1752 err = -ENOMEM; 1753 goto out; 1754 } 1755 1756out: 1757 return err; 1758} 1759 1760static __net_exit void pppol2tp_exit_net(struct net *net) 1761{ 1762 remove_proc_entry("pppol2tp", net->proc_net); 1763} 1764 1765static struct pernet_operations pppol2tp_net_ops = { 1766 .init = pppol2tp_init_net, 1767 .exit = pppol2tp_exit_net, 1768 .id = &pppol2tp_net_id, 1769}; 1770 1771/***************************************************************************** 1772 * Init and cleanup 1773 *****************************************************************************/ 1774 1775static const struct proto_ops pppol2tp_ops = { 1776 .family = AF_PPPOX, 1777 .owner = THIS_MODULE, 1778 .release = pppol2tp_release, 1779 .bind = sock_no_bind, 1780 .connect = pppol2tp_connect, 1781 .socketpair = sock_no_socketpair, 1782 .accept = sock_no_accept, 1783 .getname = pppol2tp_getname, 1784 .poll = datagram_poll, 1785 .listen = sock_no_listen, 1786 .shutdown = sock_no_shutdown, 1787 .setsockopt = pppol2tp_setsockopt, 1788 .getsockopt = pppol2tp_getsockopt, 1789 .sendmsg = pppol2tp_sendmsg, 1790 .recvmsg = pppol2tp_recvmsg, 1791 .mmap = sock_no_mmap, 1792 .ioctl = pppox_ioctl, 1793}; 1794 1795static const struct pppox_proto pppol2tp_proto = { 1796 .create = pppol2tp_create, 1797 .ioctl = pppol2tp_ioctl, 1798 .owner = THIS_MODULE, 1799}; 1800 1801#ifdef CONFIG_L2TP_V3 1802 1803static const struct l2tp_nl_cmd_ops pppol2tp_nl_cmd_ops = { 1804 .session_create = pppol2tp_session_create, 1805 .session_delete = l2tp_session_delete, 1806}; 1807 1808#endif /* CONFIG_L2TP_V3 */ 1809 1810static int __init pppol2tp_init(void) 1811{ 1812 int err; 1813 1814 err = register_pernet_device(&pppol2tp_net_ops); 1815 if (err) 1816 goto out; 1817 1818 err = proto_register(&pppol2tp_sk_proto, 0); 1819 if (err) 1820 goto out_unregister_pppol2tp_pernet; 1821 1822 err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto); 1823 if (err) 1824 goto out_unregister_pppol2tp_proto; 1825 1826#ifdef CONFIG_L2TP_V3 1827 err = l2tp_nl_register_ops(L2TP_PWTYPE_PPP, &pppol2tp_nl_cmd_ops); 1828 if (err) 1829 goto out_unregister_pppox; 1830#endif 1831 1832 pr_info("PPPoL2TP kernel driver, %s\n", PPPOL2TP_DRV_VERSION); 1833 1834out: 1835 return err; 1836 1837#ifdef CONFIG_L2TP_V3 1838out_unregister_pppox: 1839 unregister_pppox_proto(PX_PROTO_OL2TP); 1840#endif 1841out_unregister_pppol2tp_proto: 1842 proto_unregister(&pppol2tp_sk_proto); 1843out_unregister_pppol2tp_pernet: 1844 unregister_pernet_device(&pppol2tp_net_ops); 1845 goto out; 1846} 1847 1848static void __exit pppol2tp_exit(void) 1849{ 1850#ifdef CONFIG_L2TP_V3 1851 l2tp_nl_unregister_ops(L2TP_PWTYPE_PPP); 1852#endif 1853 unregister_pppox_proto(PX_PROTO_OL2TP); 1854 proto_unregister(&pppol2tp_sk_proto); 1855 unregister_pernet_device(&pppol2tp_net_ops); 1856} 1857 1858module_init(pppol2tp_init); 1859module_exit(pppol2tp_exit); 1860 1861MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); 1862MODULE_DESCRIPTION("PPP over L2TP over UDP"); 1863MODULE_LICENSE("GPL"); 1864MODULE_VERSION(PPPOL2TP_DRV_VERSION); 1865MODULE_ALIAS("pppox-proto-" __stringify(PX_PROTO_OL2TP)); 1866