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 kiocb *iocb, struct socket *sock, 189 struct msghdr *msg, size_t len, 190 int flags) 191{ 192 int err; 193 struct sk_buff *skb; 194 struct sock *sk = sock->sk; 195 196 err = -EIO; 197 if (sk->sk_state & PPPOX_BOUND) 198 goto end; 199 200 err = 0; 201 skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT, 202 flags & MSG_DONTWAIT, &err); 203 if (!skb) 204 goto end; 205 206 if (len > skb->len) 207 len = skb->len; 208 else if (len < skb->len) 209 msg->msg_flags |= MSG_TRUNC; 210 211 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, len); 212 if (likely(err == 0)) 213 err = len; 214 215 kfree_skb(skb); 216end: 217 return err; 218} 219 220static void pppol2tp_recv(struct l2tp_session *session, struct sk_buff *skb, int data_len) 221{ 222 struct pppol2tp_session *ps = l2tp_session_priv(session); 223 struct sock *sk = NULL; 224 225 /* If the socket is bound, send it in to PPP's input queue. Otherwise 226 * queue it on the session socket. 227 */ 228 sk = ps->sock; 229 if (sk == NULL) 230 goto no_sock; 231 232 if (sk->sk_state & PPPOX_BOUND) { 233 struct pppox_sock *po; 234 l2tp_dbg(session, PPPOL2TP_MSG_DATA, 235 "%s: recv %d byte data frame, passing to ppp\n", 236 session->name, data_len); 237 238 /* We need to forget all info related to the L2TP packet 239 * gathered in the skb as we are going to reuse the same 240 * skb for the inner packet. 241 * Namely we need to: 242 * - reset xfrm (IPSec) information as it applies to 243 * the outer L2TP packet and not to the inner one 244 * - release the dst to force a route lookup on the inner 245 * IP packet since skb->dst currently points to the dst 246 * of the UDP tunnel 247 * - reset netfilter information as it doesn't apply 248 * to the inner packet either 249 */ 250 secpath_reset(skb); 251 skb_dst_drop(skb); 252 nf_reset(skb); 253 254 po = pppox_sk(sk); 255 ppp_input(&po->chan, skb); 256 } else { 257 l2tp_dbg(session, PPPOL2TP_MSG_DATA, 258 "%s: recv %d byte data frame, passing to L2TP socket\n", 259 session->name, data_len); 260 261 if (sock_queue_rcv_skb(sk, skb) < 0) { 262 atomic_long_inc(&session->stats.rx_errors); 263 kfree_skb(skb); 264 } 265 } 266 267 return; 268 269no_sock: 270 l2tp_info(session, PPPOL2TP_MSG_DATA, "%s: no socket\n", session->name); 271 kfree_skb(skb); 272} 273 274static void pppol2tp_session_sock_hold(struct l2tp_session *session) 275{ 276 struct pppol2tp_session *ps = l2tp_session_priv(session); 277 278 if (ps->sock) 279 sock_hold(ps->sock); 280} 281 282static void pppol2tp_session_sock_put(struct l2tp_session *session) 283{ 284 struct pppol2tp_session *ps = l2tp_session_priv(session); 285 286 if (ps->sock) 287 sock_put(ps->sock); 288} 289 290/************************************************************************ 291 * Transmit handling 292 ***********************************************************************/ 293 294/* This is the sendmsg for the PPPoL2TP pppol2tp_session socket. We come here 295 * when a user application does a sendmsg() on the session socket. L2TP and 296 * PPP headers must be inserted into the user's data. 297 */ 298static int pppol2tp_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *m, 299 size_t total_len) 300{ 301 static const unsigned char ppph[2] = { 0xff, 0x03 }; 302 struct sock *sk = sock->sk; 303 struct sk_buff *skb; 304 int error; 305 struct l2tp_session *session; 306 struct l2tp_tunnel *tunnel; 307 struct pppol2tp_session *ps; 308 int uhlen; 309 310 error = -ENOTCONN; 311 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) 312 goto error; 313 314 /* Get session and tunnel contexts */ 315 error = -EBADF; 316 session = pppol2tp_sock_to_session(sk); 317 if (session == NULL) 318 goto error; 319 320 ps = l2tp_session_priv(session); 321 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock); 322 if (tunnel == NULL) 323 goto error_put_sess; 324 325 uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; 326 327 /* Allocate a socket buffer */ 328 error = -ENOMEM; 329 skb = sock_wmalloc(sk, NET_SKB_PAD + sizeof(struct iphdr) + 330 uhlen + session->hdr_len + 331 sizeof(ppph) + total_len, 332 0, GFP_KERNEL); 333 if (!skb) 334 goto error_put_sess_tun; 335 336 /* Reserve space for headers. */ 337 skb_reserve(skb, NET_SKB_PAD); 338 skb_reset_network_header(skb); 339 skb_reserve(skb, sizeof(struct iphdr)); 340 skb_reset_transport_header(skb); 341 skb_reserve(skb, uhlen); 342 343 /* Add PPP header */ 344 skb->data[0] = ppph[0]; 345 skb->data[1] = ppph[1]; 346 skb_put(skb, 2); 347 348 /* Copy user data into skb */ 349 error = memcpy_fromiovec(skb_put(skb, total_len), m->msg_iov, 350 total_len); 351 if (error < 0) { 352 kfree_skb(skb); 353 goto error_put_sess_tun; 354 } 355 356 local_bh_disable(); 357 l2tp_xmit_skb(session, skb, session->hdr_len); 358 local_bh_enable(); 359 360 sock_put(ps->tunnel_sock); 361 sock_put(sk); 362 363 return total_len; 364 365error_put_sess_tun: 366 sock_put(ps->tunnel_sock); 367error_put_sess: 368 sock_put(sk); 369error: 370 return error; 371} 372 373/* Transmit function called by generic PPP driver. Sends PPP frame 374 * over PPPoL2TP socket. 375 * 376 * This is almost the same as pppol2tp_sendmsg(), but rather than 377 * being called with a msghdr from userspace, it is called with a skb 378 * from the kernel. 379 * 380 * The supplied skb from ppp doesn't have enough headroom for the 381 * insertion of L2TP, UDP and IP headers so we need to allocate more 382 * headroom in the skb. This will create a cloned skb. But we must be 383 * careful in the error case because the caller will expect to free 384 * the skb it supplied, not our cloned skb. So we take care to always 385 * leave the original skb unfreed if we return an error. 386 */ 387static int pppol2tp_xmit(struct ppp_channel *chan, struct sk_buff *skb) 388{ 389 static const u8 ppph[2] = { 0xff, 0x03 }; 390 struct sock *sk = (struct sock *) chan->private; 391 struct sock *sk_tun; 392 struct l2tp_session *session; 393 struct l2tp_tunnel *tunnel; 394 struct pppol2tp_session *ps; 395 int uhlen, headroom; 396 397 if (sock_flag(sk, SOCK_DEAD) || !(sk->sk_state & PPPOX_CONNECTED)) 398 goto abort; 399 400 /* Get session and tunnel contexts from the socket */ 401 session = pppol2tp_sock_to_session(sk); 402 if (session == NULL) 403 goto abort; 404 405 ps = l2tp_session_priv(session); 406 sk_tun = ps->tunnel_sock; 407 if (sk_tun == NULL) 408 goto abort_put_sess; 409 tunnel = l2tp_sock_to_tunnel(sk_tun); 410 if (tunnel == NULL) 411 goto abort_put_sess; 412 413 uhlen = (tunnel->encap == L2TP_ENCAPTYPE_UDP) ? sizeof(struct udphdr) : 0; 414 headroom = NET_SKB_PAD + 415 sizeof(struct iphdr) + /* IP header */ 416 uhlen + /* UDP header (if L2TP_ENCAPTYPE_UDP) */ 417 session->hdr_len + /* L2TP header */ 418 sizeof(ppph); /* PPP header */ 419 if (skb_cow_head(skb, headroom)) 420 goto abort_put_sess_tun; 421 422 /* Setup PPP header */ 423 __skb_push(skb, sizeof(ppph)); 424 skb->data[0] = ppph[0]; 425 skb->data[1] = ppph[1]; 426 427 local_bh_disable(); 428 l2tp_xmit_skb(session, skb, session->hdr_len); 429 local_bh_enable(); 430 431 sock_put(sk_tun); 432 sock_put(sk); 433 return 1; 434 435abort_put_sess_tun: 436 sock_put(sk_tun); 437abort_put_sess: 438 sock_put(sk); 439abort: 440 /* Free the original skb */ 441 kfree_skb(skb); 442 return 1; 443} 444 445/***************************************************************************** 446 * Session (and tunnel control) socket create/destroy. 447 *****************************************************************************/ 448 449/* Called by l2tp_core when a session socket is being closed. 450 */ 451static void pppol2tp_session_close(struct l2tp_session *session) 452{ 453 struct pppol2tp_session *ps = l2tp_session_priv(session); 454 struct sock *sk = ps->sock; 455 struct socket *sock = sk->sk_socket; 456 457 BUG_ON(session->magic != L2TP_SESSION_MAGIC); 458 459 if (sock) { 460 inet_shutdown(sock, 2); 461 /* Don't let the session go away before our socket does */ 462 l2tp_session_inc_refcount(session); 463 } 464} 465 466/* Really kill the session socket. (Called from sock_put() if 467 * refcnt == 0.) 468 */ 469static void pppol2tp_session_destruct(struct sock *sk) 470{ 471 struct l2tp_session *session = sk->sk_user_data; 472 if (session) { 473 sk->sk_user_data = NULL; 474 BUG_ON(session->magic != L2TP_SESSION_MAGIC); 475 l2tp_session_dec_refcount(session); 476 } 477} 478 479/* Called when the PPPoX socket (session) is closed. 480 */ 481static int pppol2tp_release(struct socket *sock) 482{ 483 struct sock *sk = sock->sk; 484 struct l2tp_session *session; 485 int error; 486 487 if (!sk) 488 return 0; 489 490 error = -EBADF; 491 lock_sock(sk); 492 if (sock_flag(sk, SOCK_DEAD) != 0) 493 goto error; 494 495 pppox_unbind_sock(sk); 496 497 /* Signal the death of the socket. */ 498 sk->sk_state = PPPOX_DEAD; 499 sock_orphan(sk); 500 sock->sk = NULL; 501 502 session = pppol2tp_sock_to_session(sk); 503 504 /* Purge any queued data */ 505 if (session != NULL) { 506 __l2tp_session_unhash(session); 507 l2tp_session_queue_purge(session); 508 sock_put(sk); 509 } 510 skb_queue_purge(&sk->sk_receive_queue); 511 skb_queue_purge(&sk->sk_write_queue); 512 513 release_sock(sk); 514 515 /* This will delete the session context via 516 * pppol2tp_session_destruct() if the socket's refcnt drops to 517 * zero. 518 */ 519 sock_put(sk); 520 521 return 0; 522 523error: 524 release_sock(sk); 525 return error; 526} 527 528static struct proto pppol2tp_sk_proto = { 529 .name = "PPPOL2TP", 530 .owner = THIS_MODULE, 531 .obj_size = sizeof(struct pppox_sock), 532}; 533 534static int pppol2tp_backlog_recv(struct sock *sk, struct sk_buff *skb) 535{ 536 int rc; 537 538 rc = l2tp_udp_encap_recv(sk, skb); 539 if (rc) 540 kfree_skb(skb); 541 542 return NET_RX_SUCCESS; 543} 544 545/* socket() handler. Initialize a new struct sock. 546 */ 547static int pppol2tp_create(struct net *net, struct socket *sock) 548{ 549 int error = -ENOMEM; 550 struct sock *sk; 551 552 sk = sk_alloc(net, PF_PPPOX, GFP_KERNEL, &pppol2tp_sk_proto); 553 if (!sk) 554 goto out; 555 556 sock_init_data(sock, sk); 557 558 sock->state = SS_UNCONNECTED; 559 sock->ops = &pppol2tp_ops; 560 561 sk->sk_backlog_rcv = pppol2tp_backlog_recv; 562 sk->sk_protocol = PX_PROTO_OL2TP; 563 sk->sk_family = PF_PPPOX; 564 sk->sk_state = PPPOX_NONE; 565 sk->sk_type = SOCK_STREAM; 566 sk->sk_destruct = pppol2tp_session_destruct; 567 568 error = 0; 569 570out: 571 return error; 572} 573 574#if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE) 575static void pppol2tp_show(struct seq_file *m, void *arg) 576{ 577 struct l2tp_session *session = arg; 578 struct pppol2tp_session *ps = l2tp_session_priv(session); 579 580 if (ps) { 581 struct pppox_sock *po = pppox_sk(ps->sock); 582 if (po) 583 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan)); 584 } 585} 586#endif 587 588/* connect() handler. Attach a PPPoX socket to a tunnel UDP socket 589 */ 590static int pppol2tp_connect(struct socket *sock, struct sockaddr *uservaddr, 591 int sockaddr_len, int flags) 592{ 593 struct sock *sk = sock->sk; 594 struct sockaddr_pppol2tp *sp = (struct sockaddr_pppol2tp *) uservaddr; 595 struct pppox_sock *po = pppox_sk(sk); 596 struct l2tp_session *session = NULL; 597 struct l2tp_tunnel *tunnel; 598 struct pppol2tp_session *ps; 599 struct dst_entry *dst; 600 struct l2tp_session_cfg cfg = { 0, }; 601 int error = 0; 602 u32 tunnel_id, peer_tunnel_id; 603 u32 session_id, peer_session_id; 604 int ver = 2; 605 int fd; 606 607 lock_sock(sk); 608 609 error = -EINVAL; 610 if (sp->sa_protocol != PX_PROTO_OL2TP) 611 goto end; 612 613 /* Check for already bound sockets */ 614 error = -EBUSY; 615 if (sk->sk_state & PPPOX_CONNECTED) 616 goto end; 617 618 /* We don't supporting rebinding anyway */ 619 error = -EALREADY; 620 if (sk->sk_user_data) 621 goto end; /* socket is already attached */ 622 623 /* Get params from socket address. Handle L2TPv2 and L2TPv3. 624 * This is nasty because there are different sockaddr_pppol2tp 625 * structs for L2TPv2, L2TPv3, over IPv4 and IPv6. We use 626 * the sockaddr size to determine which structure the caller 627 * is using. 628 */ 629 peer_tunnel_id = 0; 630 if (sockaddr_len == sizeof(struct sockaddr_pppol2tp)) { 631 fd = sp->pppol2tp.fd; 632 tunnel_id = sp->pppol2tp.s_tunnel; 633 peer_tunnel_id = sp->pppol2tp.d_tunnel; 634 session_id = sp->pppol2tp.s_session; 635 peer_session_id = sp->pppol2tp.d_session; 636 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpv3)) { 637 struct sockaddr_pppol2tpv3 *sp3 = 638 (struct sockaddr_pppol2tpv3 *) sp; 639 ver = 3; 640 fd = sp3->pppol2tp.fd; 641 tunnel_id = sp3->pppol2tp.s_tunnel; 642 peer_tunnel_id = sp3->pppol2tp.d_tunnel; 643 session_id = sp3->pppol2tp.s_session; 644 peer_session_id = sp3->pppol2tp.d_session; 645 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpin6)) { 646 struct sockaddr_pppol2tpin6 *sp6 = 647 (struct sockaddr_pppol2tpin6 *) sp; 648 fd = sp6->pppol2tp.fd; 649 tunnel_id = sp6->pppol2tp.s_tunnel; 650 peer_tunnel_id = sp6->pppol2tp.d_tunnel; 651 session_id = sp6->pppol2tp.s_session; 652 peer_session_id = sp6->pppol2tp.d_session; 653 } else if (sockaddr_len == sizeof(struct sockaddr_pppol2tpv3in6)) { 654 struct sockaddr_pppol2tpv3in6 *sp6 = 655 (struct sockaddr_pppol2tpv3in6 *) sp; 656 ver = 3; 657 fd = sp6->pppol2tp.fd; 658 tunnel_id = sp6->pppol2tp.s_tunnel; 659 peer_tunnel_id = sp6->pppol2tp.d_tunnel; 660 session_id = sp6->pppol2tp.s_session; 661 peer_session_id = sp6->pppol2tp.d_session; 662 } else { 663 error = -EINVAL; 664 goto end; /* bad socket address */ 665 } 666 667 /* Don't bind if tunnel_id is 0 */ 668 error = -EINVAL; 669 if (tunnel_id == 0) 670 goto end; 671 672 tunnel = l2tp_tunnel_find(sock_net(sk), tunnel_id); 673 674 /* Special case: create tunnel context if session_id and 675 * peer_session_id is 0. Otherwise look up tunnel using supplied 676 * tunnel id. 677 */ 678 if ((session_id == 0) && (peer_session_id == 0)) { 679 if (tunnel == NULL) { 680 struct l2tp_tunnel_cfg tcfg = { 681 .encap = L2TP_ENCAPTYPE_UDP, 682 .debug = 0, 683 }; 684 error = l2tp_tunnel_create(sock_net(sk), fd, ver, tunnel_id, peer_tunnel_id, &tcfg, &tunnel); 685 if (error < 0) 686 goto end; 687 } 688 } else { 689 /* Error if we can't find the tunnel */ 690 error = -ENOENT; 691 if (tunnel == NULL) 692 goto end; 693 694 /* Error if socket is not prepped */ 695 if (tunnel->sock == NULL) 696 goto end; 697 } 698 699 if (tunnel->recv_payload_hook == NULL) 700 tunnel->recv_payload_hook = pppol2tp_recv_payload_hook; 701 702 if (tunnel->peer_tunnel_id == 0) 703 tunnel->peer_tunnel_id = peer_tunnel_id; 704 705 /* Create session if it doesn't already exist. We handle the 706 * case where a session was previously created by the netlink 707 * interface by checking that the session doesn't already have 708 * a socket and its tunnel socket are what we expect. If any 709 * of those checks fail, return EEXIST to the caller. 710 */ 711 session = l2tp_session_find(sock_net(sk), tunnel, session_id); 712 if (session == NULL) { 713 /* Default MTU must allow space for UDP/L2TP/PPP 714 * headers. 715 */ 716 cfg.mtu = cfg.mru = 1500 - PPPOL2TP_HEADER_OVERHEAD; 717 718 /* Allocate and initialize a new session context. */ 719 session = l2tp_session_create(sizeof(struct pppol2tp_session), 720 tunnel, session_id, 721 peer_session_id, &cfg); 722 if (session == NULL) { 723 error = -ENOMEM; 724 goto end; 725 } 726 } else { 727 ps = l2tp_session_priv(session); 728 error = -EEXIST; 729 if (ps->sock != NULL) 730 goto end; 731 732 /* consistency checks */ 733 if (ps->tunnel_sock != tunnel->sock) 734 goto end; 735 } 736 737 /* Associate session with its PPPoL2TP socket */ 738 ps = l2tp_session_priv(session); 739 ps->owner = current->pid; 740 ps->sock = sk; 741 ps->tunnel_sock = tunnel->sock; 742 743 session->recv_skb = pppol2tp_recv; 744 session->session_close = pppol2tp_session_close; 745#if defined(CONFIG_L2TP_DEBUGFS) || defined(CONFIG_L2TP_DEBUGFS_MODULE) 746 session->show = pppol2tp_show; 747#endif 748 749 /* We need to know each time a skb is dropped from the reorder 750 * queue. 751 */ 752 session->ref = pppol2tp_session_sock_hold; 753 session->deref = pppol2tp_session_sock_put; 754 755 /* If PMTU discovery was enabled, use the MTU that was discovered */ 756 dst = sk_dst_get(tunnel->sock); 757 if (dst != NULL) { 758 u32 pmtu = dst_mtu(dst); 759 760 if (pmtu != 0) 761 session->mtu = session->mru = pmtu - 762 PPPOL2TP_HEADER_OVERHEAD; 763 dst_release(dst); 764 } 765 766 /* Special case: if source & dest session_id == 0x0000, this 767 * socket is being created to manage the tunnel. Just set up 768 * the internal context for use by ioctl() and sockopt() 769 * handlers. 770 */ 771 if ((session->session_id == 0) && 772 (session->peer_session_id == 0)) { 773 error = 0; 774 goto out_no_ppp; 775 } 776 777 /* The only header we need to worry about is the L2TP 778 * header. This size is different depending on whether 779 * sequence numbers are enabled for the data channel. 780 */ 781 po->chan.hdrlen = PPPOL2TP_L2TP_HDR_SIZE_NOSEQ; 782 783 po->chan.private = sk; 784 po->chan.ops = &pppol2tp_chan_ops; 785 po->chan.mtu = session->mtu; 786 787 error = ppp_register_net_channel(sock_net(sk), &po->chan); 788 if (error) 789 goto end; 790 791out_no_ppp: 792 /* This is how we get the session context from the socket. */ 793 sk->sk_user_data = session; 794 sk->sk_state = PPPOX_CONNECTED; 795 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: created\n", 796 session->name); 797 798end: 799 release_sock(sk); 800 801 return error; 802} 803 804#ifdef CONFIG_L2TP_V3 805 806/* Called when creating sessions via the netlink interface. 807 */ 808static int pppol2tp_session_create(struct net *net, u32 tunnel_id, u32 session_id, u32 peer_session_id, struct l2tp_session_cfg *cfg) 809{ 810 int error; 811 struct l2tp_tunnel *tunnel; 812 struct l2tp_session *session; 813 struct pppol2tp_session *ps; 814 815 tunnel = l2tp_tunnel_find(net, tunnel_id); 816 817 /* Error if we can't find the tunnel */ 818 error = -ENOENT; 819 if (tunnel == NULL) 820 goto out; 821 822 /* Error if tunnel socket is not prepped */ 823 if (tunnel->sock == NULL) 824 goto out; 825 826 /* Check that this session doesn't already exist */ 827 error = -EEXIST; 828 session = l2tp_session_find(net, tunnel, session_id); 829 if (session != NULL) 830 goto out; 831 832 /* Default MTU values. */ 833 if (cfg->mtu == 0) 834 cfg->mtu = 1500 - PPPOL2TP_HEADER_OVERHEAD; 835 if (cfg->mru == 0) 836 cfg->mru = cfg->mtu; 837 838 /* Allocate and initialize a new session context. */ 839 error = -ENOMEM; 840 session = l2tp_session_create(sizeof(struct pppol2tp_session), 841 tunnel, session_id, 842 peer_session_id, cfg); 843 if (session == NULL) 844 goto out; 845 846 ps = l2tp_session_priv(session); 847 ps->tunnel_sock = tunnel->sock; 848 849 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: created\n", 850 session->name); 851 852 error = 0; 853 854out: 855 return error; 856} 857 858#endif /* CONFIG_L2TP_V3 */ 859 860/* getname() support. 861 */ 862static int pppol2tp_getname(struct socket *sock, struct sockaddr *uaddr, 863 int *usockaddr_len, int peer) 864{ 865 int len = 0; 866 int error = 0; 867 struct l2tp_session *session; 868 struct l2tp_tunnel *tunnel; 869 struct sock *sk = sock->sk; 870 struct inet_sock *inet; 871 struct pppol2tp_session *pls; 872 873 error = -ENOTCONN; 874 if (sk == NULL) 875 goto end; 876 if (sk->sk_state != PPPOX_CONNECTED) 877 goto end; 878 879 error = -EBADF; 880 session = pppol2tp_sock_to_session(sk); 881 if (session == NULL) 882 goto end; 883 884 pls = l2tp_session_priv(session); 885 tunnel = l2tp_sock_to_tunnel(pls->tunnel_sock); 886 if (tunnel == NULL) { 887 error = -EBADF; 888 goto end_put_sess; 889 } 890 891 inet = inet_sk(tunnel->sock); 892 if ((tunnel->version == 2) && (tunnel->sock->sk_family == AF_INET)) { 893 struct sockaddr_pppol2tp sp; 894 len = sizeof(sp); 895 memset(&sp, 0, len); 896 sp.sa_family = AF_PPPOX; 897 sp.sa_protocol = PX_PROTO_OL2TP; 898 sp.pppol2tp.fd = tunnel->fd; 899 sp.pppol2tp.pid = pls->owner; 900 sp.pppol2tp.s_tunnel = tunnel->tunnel_id; 901 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id; 902 sp.pppol2tp.s_session = session->session_id; 903 sp.pppol2tp.d_session = session->peer_session_id; 904 sp.pppol2tp.addr.sin_family = AF_INET; 905 sp.pppol2tp.addr.sin_port = inet->inet_dport; 906 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr; 907 memcpy(uaddr, &sp, len); 908#if IS_ENABLED(CONFIG_IPV6) 909 } else if ((tunnel->version == 2) && 910 (tunnel->sock->sk_family == AF_INET6)) { 911 struct sockaddr_pppol2tpin6 sp; 912 913 len = sizeof(sp); 914 memset(&sp, 0, len); 915 sp.sa_family = AF_PPPOX; 916 sp.sa_protocol = PX_PROTO_OL2TP; 917 sp.pppol2tp.fd = tunnel->fd; 918 sp.pppol2tp.pid = pls->owner; 919 sp.pppol2tp.s_tunnel = tunnel->tunnel_id; 920 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id; 921 sp.pppol2tp.s_session = session->session_id; 922 sp.pppol2tp.d_session = session->peer_session_id; 923 sp.pppol2tp.addr.sin6_family = AF_INET6; 924 sp.pppol2tp.addr.sin6_port = inet->inet_dport; 925 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr, 926 sizeof(tunnel->sock->sk_v6_daddr)); 927 memcpy(uaddr, &sp, len); 928 } else if ((tunnel->version == 3) && 929 (tunnel->sock->sk_family == AF_INET6)) { 930 struct sockaddr_pppol2tpv3in6 sp; 931 932 len = sizeof(sp); 933 memset(&sp, 0, len); 934 sp.sa_family = AF_PPPOX; 935 sp.sa_protocol = PX_PROTO_OL2TP; 936 sp.pppol2tp.fd = tunnel->fd; 937 sp.pppol2tp.pid = pls->owner; 938 sp.pppol2tp.s_tunnel = tunnel->tunnel_id; 939 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id; 940 sp.pppol2tp.s_session = session->session_id; 941 sp.pppol2tp.d_session = session->peer_session_id; 942 sp.pppol2tp.addr.sin6_family = AF_INET6; 943 sp.pppol2tp.addr.sin6_port = inet->inet_dport; 944 memcpy(&sp.pppol2tp.addr.sin6_addr, &tunnel->sock->sk_v6_daddr, 945 sizeof(tunnel->sock->sk_v6_daddr)); 946 memcpy(uaddr, &sp, len); 947#endif 948 } else if (tunnel->version == 3) { 949 struct sockaddr_pppol2tpv3 sp; 950 len = sizeof(sp); 951 memset(&sp, 0, len); 952 sp.sa_family = AF_PPPOX; 953 sp.sa_protocol = PX_PROTO_OL2TP; 954 sp.pppol2tp.fd = tunnel->fd; 955 sp.pppol2tp.pid = pls->owner; 956 sp.pppol2tp.s_tunnel = tunnel->tunnel_id; 957 sp.pppol2tp.d_tunnel = tunnel->peer_tunnel_id; 958 sp.pppol2tp.s_session = session->session_id; 959 sp.pppol2tp.d_session = session->peer_session_id; 960 sp.pppol2tp.addr.sin_family = AF_INET; 961 sp.pppol2tp.addr.sin_port = inet->inet_dport; 962 sp.pppol2tp.addr.sin_addr.s_addr = inet->inet_daddr; 963 memcpy(uaddr, &sp, len); 964 } 965 966 *usockaddr_len = len; 967 968 sock_put(pls->tunnel_sock); 969end_put_sess: 970 sock_put(sk); 971 error = 0; 972 973end: 974 return error; 975} 976 977/**************************************************************************** 978 * ioctl() handlers. 979 * 980 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP 981 * sockets. However, in order to control kernel tunnel features, we allow 982 * userspace to create a special "tunnel" PPPoX socket which is used for 983 * control only. Tunnel PPPoX sockets have session_id == 0 and simply allow 984 * the user application to issue L2TP setsockopt(), getsockopt() and ioctl() 985 * calls. 986 ****************************************************************************/ 987 988static void pppol2tp_copy_stats(struct pppol2tp_ioc_stats *dest, 989 struct l2tp_stats *stats) 990{ 991 dest->tx_packets = atomic_long_read(&stats->tx_packets); 992 dest->tx_bytes = atomic_long_read(&stats->tx_bytes); 993 dest->tx_errors = atomic_long_read(&stats->tx_errors); 994 dest->rx_packets = atomic_long_read(&stats->rx_packets); 995 dest->rx_bytes = atomic_long_read(&stats->rx_bytes); 996 dest->rx_seq_discards = atomic_long_read(&stats->rx_seq_discards); 997 dest->rx_oos_packets = atomic_long_read(&stats->rx_oos_packets); 998 dest->rx_errors = atomic_long_read(&stats->rx_errors); 999} 1000 1001/* Session ioctl helper. 1002 */ 1003static int pppol2tp_session_ioctl(struct l2tp_session *session, 1004 unsigned int cmd, unsigned long arg) 1005{ 1006 struct ifreq ifr; 1007 int err = 0; 1008 struct sock *sk; 1009 int val = (int) arg; 1010 struct pppol2tp_session *ps = l2tp_session_priv(session); 1011 struct l2tp_tunnel *tunnel = session->tunnel; 1012 struct pppol2tp_ioc_stats stats; 1013 1014 l2tp_dbg(session, PPPOL2TP_MSG_CONTROL, 1015 "%s: pppol2tp_session_ioctl(cmd=%#x, arg=%#lx)\n", 1016 session->name, cmd, arg); 1017 1018 sk = ps->sock; 1019 sock_hold(sk); 1020 1021 switch (cmd) { 1022 case SIOCGIFMTU: 1023 err = -ENXIO; 1024 if (!(sk->sk_state & PPPOX_CONNECTED)) 1025 break; 1026 1027 err = -EFAULT; 1028 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq))) 1029 break; 1030 ifr.ifr_mtu = session->mtu; 1031 if (copy_to_user((void __user *) arg, &ifr, sizeof(struct ifreq))) 1032 break; 1033 1034 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get mtu=%d\n", 1035 session->name, session->mtu); 1036 err = 0; 1037 break; 1038 1039 case SIOCSIFMTU: 1040 err = -ENXIO; 1041 if (!(sk->sk_state & PPPOX_CONNECTED)) 1042 break; 1043 1044 err = -EFAULT; 1045 if (copy_from_user(&ifr, (void __user *) arg, sizeof(struct ifreq))) 1046 break; 1047 1048 session->mtu = ifr.ifr_mtu; 1049 1050 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set mtu=%d\n", 1051 session->name, session->mtu); 1052 err = 0; 1053 break; 1054 1055 case PPPIOCGMRU: 1056 err = -ENXIO; 1057 if (!(sk->sk_state & PPPOX_CONNECTED)) 1058 break; 1059 1060 err = -EFAULT; 1061 if (put_user(session->mru, (int __user *) arg)) 1062 break; 1063 1064 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get mru=%d\n", 1065 session->name, session->mru); 1066 err = 0; 1067 break; 1068 1069 case PPPIOCSMRU: 1070 err = -ENXIO; 1071 if (!(sk->sk_state & PPPOX_CONNECTED)) 1072 break; 1073 1074 err = -EFAULT; 1075 if (get_user(val, (int __user *) arg)) 1076 break; 1077 1078 session->mru = val; 1079 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set mru=%d\n", 1080 session->name, session->mru); 1081 err = 0; 1082 break; 1083 1084 case PPPIOCGFLAGS: 1085 err = -EFAULT; 1086 if (put_user(ps->flags, (int __user *) arg)) 1087 break; 1088 1089 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get flags=%d\n", 1090 session->name, ps->flags); 1091 err = 0; 1092 break; 1093 1094 case PPPIOCSFLAGS: 1095 err = -EFAULT; 1096 if (get_user(val, (int __user *) arg)) 1097 break; 1098 ps->flags = val; 1099 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set flags=%d\n", 1100 session->name, ps->flags); 1101 err = 0; 1102 break; 1103 1104 case PPPIOCGL2TPSTATS: 1105 err = -ENXIO; 1106 if (!(sk->sk_state & PPPOX_CONNECTED)) 1107 break; 1108 1109 memset(&stats, 0, sizeof(stats)); 1110 stats.tunnel_id = tunnel->tunnel_id; 1111 stats.session_id = session->session_id; 1112 pppol2tp_copy_stats(&stats, &session->stats); 1113 if (copy_to_user((void __user *) arg, &stats, 1114 sizeof(stats))) 1115 break; 1116 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get L2TP stats\n", 1117 session->name); 1118 err = 0; 1119 break; 1120 1121 default: 1122 err = -ENOSYS; 1123 break; 1124 } 1125 1126 sock_put(sk); 1127 1128 return err; 1129} 1130 1131/* Tunnel ioctl helper. 1132 * 1133 * Note the special handling for PPPIOCGL2TPSTATS below. If the ioctl data 1134 * specifies a session_id, the session ioctl handler is called. This allows an 1135 * application to retrieve session stats via a tunnel socket. 1136 */ 1137static int pppol2tp_tunnel_ioctl(struct l2tp_tunnel *tunnel, 1138 unsigned int cmd, unsigned long arg) 1139{ 1140 int err = 0; 1141 struct sock *sk; 1142 struct pppol2tp_ioc_stats stats; 1143 1144 l2tp_dbg(tunnel, PPPOL2TP_MSG_CONTROL, 1145 "%s: pppol2tp_tunnel_ioctl(cmd=%#x, arg=%#lx)\n", 1146 tunnel->name, cmd, arg); 1147 1148 sk = tunnel->sock; 1149 sock_hold(sk); 1150 1151 switch (cmd) { 1152 case PPPIOCGL2TPSTATS: 1153 err = -ENXIO; 1154 if (!(sk->sk_state & PPPOX_CONNECTED)) 1155 break; 1156 1157 if (copy_from_user(&stats, (void __user *) arg, 1158 sizeof(stats))) { 1159 err = -EFAULT; 1160 break; 1161 } 1162 if (stats.session_id != 0) { 1163 /* resend to session ioctl handler */ 1164 struct l2tp_session *session = 1165 l2tp_session_find(sock_net(sk), tunnel, stats.session_id); 1166 if (session != NULL) 1167 err = pppol2tp_session_ioctl(session, cmd, arg); 1168 else 1169 err = -EBADR; 1170 break; 1171 } 1172#ifdef CONFIG_XFRM 1173 stats.using_ipsec = (sk->sk_policy[0] || sk->sk_policy[1]) ? 1 : 0; 1174#endif 1175 pppol2tp_copy_stats(&stats, &tunnel->stats); 1176 if (copy_to_user((void __user *) arg, &stats, sizeof(stats))) { 1177 err = -EFAULT; 1178 break; 1179 } 1180 l2tp_info(tunnel, PPPOL2TP_MSG_CONTROL, "%s: get L2TP stats\n", 1181 tunnel->name); 1182 err = 0; 1183 break; 1184 1185 default: 1186 err = -ENOSYS; 1187 break; 1188 } 1189 1190 sock_put(sk); 1191 1192 return err; 1193} 1194 1195/* Main ioctl() handler. 1196 * Dispatch to tunnel or session helpers depending on the socket. 1197 */ 1198static int pppol2tp_ioctl(struct socket *sock, unsigned int cmd, 1199 unsigned long arg) 1200{ 1201 struct sock *sk = sock->sk; 1202 struct l2tp_session *session; 1203 struct l2tp_tunnel *tunnel; 1204 struct pppol2tp_session *ps; 1205 int err; 1206 1207 if (!sk) 1208 return 0; 1209 1210 err = -EBADF; 1211 if (sock_flag(sk, SOCK_DEAD) != 0) 1212 goto end; 1213 1214 err = -ENOTCONN; 1215 if ((sk->sk_user_data == NULL) || 1216 (!(sk->sk_state & (PPPOX_CONNECTED | PPPOX_BOUND)))) 1217 goto end; 1218 1219 /* Get session context from the socket */ 1220 err = -EBADF; 1221 session = pppol2tp_sock_to_session(sk); 1222 if (session == NULL) 1223 goto end; 1224 1225 /* Special case: if session's session_id is zero, treat ioctl as a 1226 * tunnel ioctl 1227 */ 1228 ps = l2tp_session_priv(session); 1229 if ((session->session_id == 0) && 1230 (session->peer_session_id == 0)) { 1231 err = -EBADF; 1232 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock); 1233 if (tunnel == NULL) 1234 goto end_put_sess; 1235 1236 err = pppol2tp_tunnel_ioctl(tunnel, cmd, arg); 1237 sock_put(ps->tunnel_sock); 1238 goto end_put_sess; 1239 } 1240 1241 err = pppol2tp_session_ioctl(session, cmd, arg); 1242 1243end_put_sess: 1244 sock_put(sk); 1245end: 1246 return err; 1247} 1248 1249/***************************************************************************** 1250 * setsockopt() / getsockopt() support. 1251 * 1252 * The PPPoX socket is created for L2TP sessions: tunnels have their own UDP 1253 * sockets. In order to control kernel tunnel features, we allow userspace to 1254 * create a special "tunnel" PPPoX socket which is used for control only. 1255 * Tunnel PPPoX sockets have session_id == 0 and simply allow the user 1256 * application to issue L2TP setsockopt(), getsockopt() and ioctl() calls. 1257 *****************************************************************************/ 1258 1259/* Tunnel setsockopt() helper. 1260 */ 1261static int pppol2tp_tunnel_setsockopt(struct sock *sk, 1262 struct l2tp_tunnel *tunnel, 1263 int optname, int val) 1264{ 1265 int err = 0; 1266 1267 switch (optname) { 1268 case PPPOL2TP_SO_DEBUG: 1269 tunnel->debug = val; 1270 l2tp_info(tunnel, PPPOL2TP_MSG_CONTROL, "%s: set debug=%x\n", 1271 tunnel->name, tunnel->debug); 1272 break; 1273 1274 default: 1275 err = -ENOPROTOOPT; 1276 break; 1277 } 1278 1279 return err; 1280} 1281 1282/* Session setsockopt helper. 1283 */ 1284static int pppol2tp_session_setsockopt(struct sock *sk, 1285 struct l2tp_session *session, 1286 int optname, int val) 1287{ 1288 int err = 0; 1289 struct pppol2tp_session *ps = l2tp_session_priv(session); 1290 1291 switch (optname) { 1292 case PPPOL2TP_SO_RECVSEQ: 1293 if ((val != 0) && (val != 1)) { 1294 err = -EINVAL; 1295 break; 1296 } 1297 session->recv_seq = val ? -1 : 0; 1298 l2tp_info(session, PPPOL2TP_MSG_CONTROL, 1299 "%s: set recv_seq=%d\n", 1300 session->name, session->recv_seq); 1301 break; 1302 1303 case PPPOL2TP_SO_SENDSEQ: 1304 if ((val != 0) && (val != 1)) { 1305 err = -EINVAL; 1306 break; 1307 } 1308 session->send_seq = val ? -1 : 0; 1309 { 1310 struct sock *ssk = ps->sock; 1311 struct pppox_sock *po = pppox_sk(ssk); 1312 po->chan.hdrlen = val ? PPPOL2TP_L2TP_HDR_SIZE_SEQ : 1313 PPPOL2TP_L2TP_HDR_SIZE_NOSEQ; 1314 } 1315 l2tp_session_set_header_len(session, session->tunnel->version); 1316 l2tp_info(session, PPPOL2TP_MSG_CONTROL, 1317 "%s: set send_seq=%d\n", 1318 session->name, session->send_seq); 1319 break; 1320 1321 case PPPOL2TP_SO_LNSMODE: 1322 if ((val != 0) && (val != 1)) { 1323 err = -EINVAL; 1324 break; 1325 } 1326 session->lns_mode = val ? -1 : 0; 1327 l2tp_info(session, PPPOL2TP_MSG_CONTROL, 1328 "%s: set lns_mode=%d\n", 1329 session->name, session->lns_mode); 1330 break; 1331 1332 case PPPOL2TP_SO_DEBUG: 1333 session->debug = val; 1334 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: set debug=%x\n", 1335 session->name, session->debug); 1336 break; 1337 1338 case PPPOL2TP_SO_REORDERTO: 1339 session->reorder_timeout = msecs_to_jiffies(val); 1340 l2tp_info(session, PPPOL2TP_MSG_CONTROL, 1341 "%s: set reorder_timeout=%d\n", 1342 session->name, session->reorder_timeout); 1343 break; 1344 1345 default: 1346 err = -ENOPROTOOPT; 1347 break; 1348 } 1349 1350 return err; 1351} 1352 1353/* Main setsockopt() entry point. 1354 * Does API checks, then calls either the tunnel or session setsockopt 1355 * handler, according to whether the PPPoL2TP socket is a for a regular 1356 * session or the special tunnel type. 1357 */ 1358static int pppol2tp_setsockopt(struct socket *sock, int level, int optname, 1359 char __user *optval, unsigned int optlen) 1360{ 1361 struct sock *sk = sock->sk; 1362 struct l2tp_session *session; 1363 struct l2tp_tunnel *tunnel; 1364 struct pppol2tp_session *ps; 1365 int val; 1366 int err; 1367 1368 if (level != SOL_PPPOL2TP) 1369 return -EINVAL; 1370 1371 if (optlen < sizeof(int)) 1372 return -EINVAL; 1373 1374 if (get_user(val, (int __user *)optval)) 1375 return -EFAULT; 1376 1377 err = -ENOTCONN; 1378 if (sk->sk_user_data == NULL) 1379 goto end; 1380 1381 /* Get session context from the socket */ 1382 err = -EBADF; 1383 session = pppol2tp_sock_to_session(sk); 1384 if (session == NULL) 1385 goto end; 1386 1387 /* Special case: if session_id == 0x0000, treat as operation on tunnel 1388 */ 1389 ps = l2tp_session_priv(session); 1390 if ((session->session_id == 0) && 1391 (session->peer_session_id == 0)) { 1392 err = -EBADF; 1393 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock); 1394 if (tunnel == NULL) 1395 goto end_put_sess; 1396 1397 err = pppol2tp_tunnel_setsockopt(sk, tunnel, optname, val); 1398 sock_put(ps->tunnel_sock); 1399 } else 1400 err = pppol2tp_session_setsockopt(sk, session, optname, val); 1401 1402 err = 0; 1403 1404end_put_sess: 1405 sock_put(sk); 1406end: 1407 return err; 1408} 1409 1410/* Tunnel getsockopt helper. Called with sock locked. 1411 */ 1412static int pppol2tp_tunnel_getsockopt(struct sock *sk, 1413 struct l2tp_tunnel *tunnel, 1414 int optname, int *val) 1415{ 1416 int err = 0; 1417 1418 switch (optname) { 1419 case PPPOL2TP_SO_DEBUG: 1420 *val = tunnel->debug; 1421 l2tp_info(tunnel, PPPOL2TP_MSG_CONTROL, "%s: get debug=%x\n", 1422 tunnel->name, tunnel->debug); 1423 break; 1424 1425 default: 1426 err = -ENOPROTOOPT; 1427 break; 1428 } 1429 1430 return err; 1431} 1432 1433/* Session getsockopt helper. Called with sock locked. 1434 */ 1435static int pppol2tp_session_getsockopt(struct sock *sk, 1436 struct l2tp_session *session, 1437 int optname, int *val) 1438{ 1439 int err = 0; 1440 1441 switch (optname) { 1442 case PPPOL2TP_SO_RECVSEQ: 1443 *val = session->recv_seq; 1444 l2tp_info(session, PPPOL2TP_MSG_CONTROL, 1445 "%s: get recv_seq=%d\n", session->name, *val); 1446 break; 1447 1448 case PPPOL2TP_SO_SENDSEQ: 1449 *val = session->send_seq; 1450 l2tp_info(session, PPPOL2TP_MSG_CONTROL, 1451 "%s: get send_seq=%d\n", session->name, *val); 1452 break; 1453 1454 case PPPOL2TP_SO_LNSMODE: 1455 *val = session->lns_mode; 1456 l2tp_info(session, PPPOL2TP_MSG_CONTROL, 1457 "%s: get lns_mode=%d\n", session->name, *val); 1458 break; 1459 1460 case PPPOL2TP_SO_DEBUG: 1461 *val = session->debug; 1462 l2tp_info(session, PPPOL2TP_MSG_CONTROL, "%s: get debug=%d\n", 1463 session->name, *val); 1464 break; 1465 1466 case PPPOL2TP_SO_REORDERTO: 1467 *val = (int) jiffies_to_msecs(session->reorder_timeout); 1468 l2tp_info(session, PPPOL2TP_MSG_CONTROL, 1469 "%s: get reorder_timeout=%d\n", session->name, *val); 1470 break; 1471 1472 default: 1473 err = -ENOPROTOOPT; 1474 } 1475 1476 return err; 1477} 1478 1479/* Main getsockopt() entry point. 1480 * Does API checks, then calls either the tunnel or session getsockopt 1481 * handler, according to whether the PPPoX socket is a for a regular session 1482 * or the special tunnel type. 1483 */ 1484static int pppol2tp_getsockopt(struct socket *sock, int level, int optname, 1485 char __user *optval, int __user *optlen) 1486{ 1487 struct sock *sk = sock->sk; 1488 struct l2tp_session *session; 1489 struct l2tp_tunnel *tunnel; 1490 int val, len; 1491 int err; 1492 struct pppol2tp_session *ps; 1493 1494 if (level != SOL_PPPOL2TP) 1495 return -EINVAL; 1496 1497 if (get_user(len, optlen)) 1498 return -EFAULT; 1499 1500 len = min_t(unsigned int, len, sizeof(int)); 1501 1502 if (len < 0) 1503 return -EINVAL; 1504 1505 err = -ENOTCONN; 1506 if (sk->sk_user_data == NULL) 1507 goto end; 1508 1509 /* Get the session context */ 1510 err = -EBADF; 1511 session = pppol2tp_sock_to_session(sk); 1512 if (session == NULL) 1513 goto end; 1514 1515 /* Special case: if session_id == 0x0000, treat as operation on tunnel */ 1516 ps = l2tp_session_priv(session); 1517 if ((session->session_id == 0) && 1518 (session->peer_session_id == 0)) { 1519 err = -EBADF; 1520 tunnel = l2tp_sock_to_tunnel(ps->tunnel_sock); 1521 if (tunnel == NULL) 1522 goto end_put_sess; 1523 1524 err = pppol2tp_tunnel_getsockopt(sk, tunnel, optname, &val); 1525 sock_put(ps->tunnel_sock); 1526 } else 1527 err = pppol2tp_session_getsockopt(sk, session, optname, &val); 1528 1529 err = -EFAULT; 1530 if (put_user(len, optlen)) 1531 goto end_put_sess; 1532 1533 if (copy_to_user((void __user *) optval, &val, len)) 1534 goto end_put_sess; 1535 1536 err = 0; 1537 1538end_put_sess: 1539 sock_put(sk); 1540end: 1541 return err; 1542} 1543 1544/***************************************************************************** 1545 * /proc filesystem for debug 1546 * Since the original pppol2tp driver provided /proc/net/pppol2tp for 1547 * L2TPv2, we dump only L2TPv2 tunnels and sessions here. 1548 *****************************************************************************/ 1549 1550static unsigned int pppol2tp_net_id; 1551 1552#ifdef CONFIG_PROC_FS 1553 1554struct pppol2tp_seq_data { 1555 struct seq_net_private p; 1556 int tunnel_idx; /* current tunnel */ 1557 int session_idx; /* index of session within current tunnel */ 1558 struct l2tp_tunnel *tunnel; 1559 struct l2tp_session *session; /* NULL means get next tunnel */ 1560}; 1561 1562static void pppol2tp_next_tunnel(struct net *net, struct pppol2tp_seq_data *pd) 1563{ 1564 for (;;) { 1565 pd->tunnel = l2tp_tunnel_find_nth(net, pd->tunnel_idx); 1566 pd->tunnel_idx++; 1567 1568 if (pd->tunnel == NULL) 1569 break; 1570 1571 /* Ignore L2TPv3 tunnels */ 1572 if (pd->tunnel->version < 3) 1573 break; 1574 } 1575} 1576 1577static void pppol2tp_next_session(struct net *net, struct pppol2tp_seq_data *pd) 1578{ 1579 pd->session = l2tp_session_find_nth(pd->tunnel, pd->session_idx); 1580 pd->session_idx++; 1581 1582 if (pd->session == NULL) { 1583 pd->session_idx = 0; 1584 pppol2tp_next_tunnel(net, pd); 1585 } 1586} 1587 1588static void *pppol2tp_seq_start(struct seq_file *m, loff_t *offs) 1589{ 1590 struct pppol2tp_seq_data *pd = SEQ_START_TOKEN; 1591 loff_t pos = *offs; 1592 struct net *net; 1593 1594 if (!pos) 1595 goto out; 1596 1597 BUG_ON(m->private == NULL); 1598 pd = m->private; 1599 net = seq_file_net(m); 1600 1601 if (pd->tunnel == NULL) 1602 pppol2tp_next_tunnel(net, pd); 1603 else 1604 pppol2tp_next_session(net, pd); 1605 1606 /* NULL tunnel and session indicates end of list */ 1607 if ((pd->tunnel == NULL) && (pd->session == NULL)) 1608 pd = NULL; 1609 1610out: 1611 return pd; 1612} 1613 1614static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos) 1615{ 1616 (*pos)++; 1617 return NULL; 1618} 1619 1620static void pppol2tp_seq_stop(struct seq_file *p, void *v) 1621{ 1622 /* nothing to do */ 1623} 1624 1625static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v) 1626{ 1627 struct l2tp_tunnel *tunnel = v; 1628 1629 seq_printf(m, "\nTUNNEL '%s', %c %d\n", 1630 tunnel->name, 1631 (tunnel == tunnel->sock->sk_user_data) ? 'Y' : 'N', 1632 atomic_read(&tunnel->ref_count) - 1); 1633 seq_printf(m, " %08x %ld/%ld/%ld %ld/%ld/%ld\n", 1634 tunnel->debug, 1635 atomic_long_read(&tunnel->stats.tx_packets), 1636 atomic_long_read(&tunnel->stats.tx_bytes), 1637 atomic_long_read(&tunnel->stats.tx_errors), 1638 atomic_long_read(&tunnel->stats.rx_packets), 1639 atomic_long_read(&tunnel->stats.rx_bytes), 1640 atomic_long_read(&tunnel->stats.rx_errors)); 1641} 1642 1643static void pppol2tp_seq_session_show(struct seq_file *m, void *v) 1644{ 1645 struct l2tp_session *session = v; 1646 struct l2tp_tunnel *tunnel = session->tunnel; 1647 struct pppol2tp_session *ps = l2tp_session_priv(session); 1648 struct pppox_sock *po = pppox_sk(ps->sock); 1649 u32 ip = 0; 1650 u16 port = 0; 1651 1652 if (tunnel->sock) { 1653 struct inet_sock *inet = inet_sk(tunnel->sock); 1654 ip = ntohl(inet->inet_saddr); 1655 port = ntohs(inet->inet_sport); 1656 } 1657 1658 seq_printf(m, " SESSION '%s' %08X/%d %04X/%04X -> " 1659 "%04X/%04X %d %c\n", 1660 session->name, ip, port, 1661 tunnel->tunnel_id, 1662 session->session_id, 1663 tunnel->peer_tunnel_id, 1664 session->peer_session_id, 1665 ps->sock->sk_state, 1666 (session == ps->sock->sk_user_data) ? 1667 'Y' : 'N'); 1668 seq_printf(m, " %d/%d/%c/%c/%s %08x %u\n", 1669 session->mtu, session->mru, 1670 session->recv_seq ? 'R' : '-', 1671 session->send_seq ? 'S' : '-', 1672 session->lns_mode ? "LNS" : "LAC", 1673 session->debug, 1674 jiffies_to_msecs(session->reorder_timeout)); 1675 seq_printf(m, " %hu/%hu %ld/%ld/%ld %ld/%ld/%ld\n", 1676 session->nr, session->ns, 1677 atomic_long_read(&session->stats.tx_packets), 1678 atomic_long_read(&session->stats.tx_bytes), 1679 atomic_long_read(&session->stats.tx_errors), 1680 atomic_long_read(&session->stats.rx_packets), 1681 atomic_long_read(&session->stats.rx_bytes), 1682 atomic_long_read(&session->stats.rx_errors)); 1683 1684 if (po) 1685 seq_printf(m, " interface %s\n", ppp_dev_name(&po->chan)); 1686} 1687 1688static int pppol2tp_seq_show(struct seq_file *m, void *v) 1689{ 1690 struct pppol2tp_seq_data *pd = v; 1691 1692 /* display header on line 1 */ 1693 if (v == SEQ_START_TOKEN) { 1694 seq_puts(m, "PPPoL2TP driver info, " PPPOL2TP_DRV_VERSION "\n"); 1695 seq_puts(m, "TUNNEL name, user-data-ok session-count\n"); 1696 seq_puts(m, " debug tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); 1697 seq_puts(m, " SESSION name, addr/port src-tid/sid " 1698 "dest-tid/sid state user-data-ok\n"); 1699 seq_puts(m, " mtu/mru/rcvseq/sendseq/lns debug reorderto\n"); 1700 seq_puts(m, " nr/ns tx-pkts/bytes/errs rx-pkts/bytes/errs\n"); 1701 goto out; 1702 } 1703 1704 /* Show the tunnel or session context. 1705 */ 1706 if (pd->session == NULL) 1707 pppol2tp_seq_tunnel_show(m, pd->tunnel); 1708 else 1709 pppol2tp_seq_session_show(m, pd->session); 1710 1711out: 1712 return 0; 1713} 1714 1715static const struct seq_operations pppol2tp_seq_ops = { 1716 .start = pppol2tp_seq_start, 1717 .next = pppol2tp_seq_next, 1718 .stop = pppol2tp_seq_stop, 1719 .show = pppol2tp_seq_show, 1720}; 1721 1722/* Called when our /proc file is opened. We allocate data for use when 1723 * iterating our tunnel / session contexts and store it in the private 1724 * data of the seq_file. 1725 */ 1726static int pppol2tp_proc_open(struct inode *inode, struct file *file) 1727{ 1728 return seq_open_net(inode, file, &pppol2tp_seq_ops, 1729 sizeof(struct pppol2tp_seq_data)); 1730} 1731 1732static const struct file_operations pppol2tp_proc_fops = { 1733 .owner = THIS_MODULE, 1734 .open = pppol2tp_proc_open, 1735 .read = seq_read, 1736 .llseek = seq_lseek, 1737 .release = seq_release_net, 1738}; 1739 1740#endif /* CONFIG_PROC_FS */ 1741 1742/***************************************************************************** 1743 * Network namespace 1744 *****************************************************************************/ 1745 1746static __net_init int pppol2tp_init_net(struct net *net) 1747{ 1748 struct proc_dir_entry *pde; 1749 int err = 0; 1750 1751 pde = proc_create("pppol2tp", S_IRUGO, net->proc_net, 1752 &pppol2tp_proc_fops); 1753 if (!pde) { 1754 err = -ENOMEM; 1755 goto out; 1756 } 1757 1758out: 1759 return err; 1760} 1761 1762static __net_exit void pppol2tp_exit_net(struct net *net) 1763{ 1764 remove_proc_entry("pppol2tp", net->proc_net); 1765} 1766 1767static struct pernet_operations pppol2tp_net_ops = { 1768 .init = pppol2tp_init_net, 1769 .exit = pppol2tp_exit_net, 1770 .id = &pppol2tp_net_id, 1771}; 1772 1773/***************************************************************************** 1774 * Init and cleanup 1775 *****************************************************************************/ 1776 1777static const struct proto_ops pppol2tp_ops = { 1778 .family = AF_PPPOX, 1779 .owner = THIS_MODULE, 1780 .release = pppol2tp_release, 1781 .bind = sock_no_bind, 1782 .connect = pppol2tp_connect, 1783 .socketpair = sock_no_socketpair, 1784 .accept = sock_no_accept, 1785 .getname = pppol2tp_getname, 1786 .poll = datagram_poll, 1787 .listen = sock_no_listen, 1788 .shutdown = sock_no_shutdown, 1789 .setsockopt = pppol2tp_setsockopt, 1790 .getsockopt = pppol2tp_getsockopt, 1791 .sendmsg = pppol2tp_sendmsg, 1792 .recvmsg = pppol2tp_recvmsg, 1793 .mmap = sock_no_mmap, 1794 .ioctl = pppox_ioctl, 1795}; 1796 1797static const struct pppox_proto pppol2tp_proto = { 1798 .create = pppol2tp_create, 1799 .ioctl = pppol2tp_ioctl, 1800 .owner = THIS_MODULE, 1801}; 1802 1803#ifdef CONFIG_L2TP_V3 1804 1805static const struct l2tp_nl_cmd_ops pppol2tp_nl_cmd_ops = { 1806 .session_create = pppol2tp_session_create, 1807 .session_delete = l2tp_session_delete, 1808}; 1809 1810#endif /* CONFIG_L2TP_V3 */ 1811 1812static int __init pppol2tp_init(void) 1813{ 1814 int err; 1815 1816 err = register_pernet_device(&pppol2tp_net_ops); 1817 if (err) 1818 goto out; 1819 1820 err = proto_register(&pppol2tp_sk_proto, 0); 1821 if (err) 1822 goto out_unregister_pppol2tp_pernet; 1823 1824 err = register_pppox_proto(PX_PROTO_OL2TP, &pppol2tp_proto); 1825 if (err) 1826 goto out_unregister_pppol2tp_proto; 1827 1828#ifdef CONFIG_L2TP_V3 1829 err = l2tp_nl_register_ops(L2TP_PWTYPE_PPP, &pppol2tp_nl_cmd_ops); 1830 if (err) 1831 goto out_unregister_pppox; 1832#endif 1833 1834 pr_info("PPPoL2TP kernel driver, %s\n", PPPOL2TP_DRV_VERSION); 1835 1836out: 1837 return err; 1838 1839#ifdef CONFIG_L2TP_V3 1840out_unregister_pppox: 1841 unregister_pppox_proto(PX_PROTO_OL2TP); 1842#endif 1843out_unregister_pppol2tp_proto: 1844 proto_unregister(&pppol2tp_sk_proto); 1845out_unregister_pppol2tp_pernet: 1846 unregister_pernet_device(&pppol2tp_net_ops); 1847 goto out; 1848} 1849 1850static void __exit pppol2tp_exit(void) 1851{ 1852#ifdef CONFIG_L2TP_V3 1853 l2tp_nl_unregister_ops(L2TP_PWTYPE_PPP); 1854#endif 1855 unregister_pppox_proto(PX_PROTO_OL2TP); 1856 proto_unregister(&pppol2tp_sk_proto); 1857 unregister_pernet_device(&pppol2tp_net_ops); 1858} 1859 1860module_init(pppol2tp_init); 1861module_exit(pppol2tp_exit); 1862 1863MODULE_AUTHOR("James Chapman <jchapman@katalix.com>"); 1864MODULE_DESCRIPTION("PPP over L2TP over UDP"); 1865MODULE_LICENSE("GPL"); 1866MODULE_VERSION(PPPOL2TP_DRV_VERSION); 1867MODULE_ALIAS("pppox-proto-" __stringify(PX_PROTO_OL2TP)); 1868