1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Generic PPP layer for Linux. 4 * 5 * Copyright 1999-2002 Paul Mackerras. 6 * 7 * The generic PPP layer handles the PPP network interfaces, the 8 * /dev/ppp device, packet and VJ compression, and multilink. 9 * It talks to PPP `channels' via the interface defined in 10 * include/linux/ppp_channel.h. Channels provide the basic means for 11 * sending and receiving PPP frames on some kind of communications 12 * channel. 13 * 14 * Part of the code in this driver was inspired by the old async-only 15 * PPP driver, written by Michael Callahan and Al Longyear, and 16 * subsequently hacked by Paul Mackerras. 17 * 18 * ==FILEVERSION 20041108== 19 */ 20 21 #include <linux/module.h> 22 #include <linux/kernel.h> 23 #include <linux/sched/signal.h> 24 #include <linux/kmod.h> 25 #include <linux/init.h> 26 #include <linux/list.h> 27 #include <linux/idr.h> 28 #include <linux/netdevice.h> 29 #include <linux/poll.h> 30 #include <linux/ppp_defs.h> 31 #include <linux/filter.h> 32 #include <linux/ppp-ioctl.h> 33 #include <linux/ppp_channel.h> 34 #include <linux/ppp-comp.h> 35 #include <linux/skbuff.h> 36 #include <linux/rtnetlink.h> 37 #include <linux/if_arp.h> 38 #include <linux/ip.h> 39 #include <linux/tcp.h> 40 #include <linux/spinlock.h> 41 #include <linux/rwsem.h> 42 #include <linux/stddef.h> 43 #include <linux/device.h> 44 #include <linux/mutex.h> 45 #include <linux/slab.h> 46 #include <linux/file.h> 47 #include <asm/unaligned.h> 48 #include <net/slhc_vj.h> 49 #include <linux/atomic.h> 50 #include <linux/refcount.h> 51 52 #include <linux/nsproxy.h> 53 #include <net/net_namespace.h> 54 #include <net/netns/generic.h> 55 56 #define PPP_VERSION "2.4.2" 57 58 /* 59 * Network protocols we support. 60 */ 61 #define NP_IP 0 /* Internet Protocol V4 */ 62 #define NP_IPV6 1 /* Internet Protocol V6 */ 63 #define NP_IPX 2 /* IPX protocol */ 64 #define NP_AT 3 /* Appletalk protocol */ 65 #define NP_MPLS_UC 4 /* MPLS unicast */ 66 #define NP_MPLS_MC 5 /* MPLS multicast */ 67 #define NUM_NP 6 /* Number of NPs. */ 68 69 #define MPHDRLEN 6 /* multilink protocol header length */ 70 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */ 71 72 /* 73 * An instance of /dev/ppp can be associated with either a ppp 74 * interface unit or a ppp channel. In both cases, file->private_data 75 * points to one of these. 76 */ 77 struct ppp_file { 78 enum { 79 INTERFACE=1, CHANNEL 80 } kind; 81 struct sk_buff_head xq; /* pppd transmit queue */ 82 struct sk_buff_head rq; /* receive queue for pppd */ 83 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */ 84 refcount_t refcnt; /* # refs (incl /dev/ppp attached) */ 85 int hdrlen; /* space to leave for headers */ 86 int index; /* interface unit / channel number */ 87 int dead; /* unit/channel has been shut down */ 88 }; 89 90 #define PF_TO_X(pf, X) container_of(pf, X, file) 91 92 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp) 93 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel) 94 95 /* 96 * Data structure to hold primary network stats for which 97 * we want to use 64 bit storage. Other network stats 98 * are stored in dev->stats of the ppp strucute. 99 */ 100 struct ppp_link_stats { 101 u64 rx_packets; 102 u64 tx_packets; 103 u64 rx_bytes; 104 u64 tx_bytes; 105 }; 106 107 /* 108 * Data structure describing one ppp unit. 109 * A ppp unit corresponds to a ppp network interface device 110 * and represents a multilink bundle. 111 * It can have 0 or more ppp channels connected to it. 112 */ 113 struct ppp { 114 struct ppp_file file; /* stuff for read/write/poll 0 */ 115 struct file *owner; /* file that owns this unit 48 */ 116 struct list_head channels; /* list of attached channels 4c */ 117 int n_channels; /* how many channels are attached 54 */ 118 spinlock_t rlock; /* lock for receive side 58 */ 119 spinlock_t wlock; /* lock for transmit side 5c */ 120 int __percpu *xmit_recursion; /* xmit recursion detect */ 121 int mru; /* max receive unit 60 */ 122 unsigned int flags; /* control bits 64 */ 123 unsigned int xstate; /* transmit state bits 68 */ 124 unsigned int rstate; /* receive state bits 6c */ 125 int debug; /* debug flags 70 */ 126 struct slcompress *vj; /* state for VJ header compression */ 127 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */ 128 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */ 129 struct compressor *xcomp; /* transmit packet compressor 8c */ 130 void *xc_state; /* its internal state 90 */ 131 struct compressor *rcomp; /* receive decompressor 94 */ 132 void *rc_state; /* its internal state 98 */ 133 unsigned long last_xmit; /* jiffies when last pkt sent 9c */ 134 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */ 135 struct net_device *dev; /* network interface device a4 */ 136 int closing; /* is device closing down? a8 */ 137 #ifdef CONFIG_PPP_MULTILINK 138 int nxchan; /* next channel to send something on */ 139 u32 nxseq; /* next sequence number to send */ 140 int mrru; /* MP: max reconst. receive unit */ 141 u32 nextseq; /* MP: seq no of next packet */ 142 u32 minseq; /* MP: min of most recent seqnos */ 143 struct sk_buff_head mrq; /* MP: receive reconstruction queue */ 144 #endif /* CONFIG_PPP_MULTILINK */ 145 #ifdef CONFIG_PPP_FILTER 146 struct bpf_prog *pass_filter; /* filter for packets to pass */ 147 struct bpf_prog *active_filter; /* filter for pkts to reset idle */ 148 #endif /* CONFIG_PPP_FILTER */ 149 struct net *ppp_net; /* the net we belong to */ 150 struct ppp_link_stats stats64; /* 64 bit network stats */ 151 }; 152 153 /* 154 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC, 155 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP, 156 * SC_MUST_COMP 157 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR. 158 * Bits in xstate: SC_COMP_RUN 159 */ 160 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \ 161 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \ 162 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP) 163 164 /* 165 * Private data structure for each channel. 166 * This includes the data structure used for multilink. 167 */ 168 struct channel { 169 struct ppp_file file; /* stuff for read/write/poll */ 170 struct list_head list; /* link in all/new_channels list */ 171 struct ppp_channel *chan; /* public channel data structure */ 172 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */ 173 spinlock_t downl; /* protects `chan', file.xq dequeue */ 174 struct ppp *ppp; /* ppp unit we're connected to */ 175 struct net *chan_net; /* the net channel belongs to */ 176 struct list_head clist; /* link in list of channels per unit */ 177 rwlock_t upl; /* protects `ppp' and 'bridge' */ 178 struct channel __rcu *bridge; /* "bridged" ppp channel */ 179 #ifdef CONFIG_PPP_MULTILINK 180 u8 avail; /* flag used in multilink stuff */ 181 u8 had_frag; /* >= 1 fragments have been sent */ 182 u32 lastseq; /* MP: last sequence # received */ 183 int speed; /* speed of the corresponding ppp channel*/ 184 #endif /* CONFIG_PPP_MULTILINK */ 185 }; 186 187 struct ppp_config { 188 struct file *file; 189 s32 unit; 190 bool ifname_is_set; 191 }; 192 193 /* 194 * SMP locking issues: 195 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels 196 * list and the ppp.n_channels field, you need to take both locks 197 * before you modify them. 198 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock -> 199 * channel.downl. 200 */ 201 202 static DEFINE_MUTEX(ppp_mutex); 203 static atomic_t ppp_unit_count = ATOMIC_INIT(0); 204 static atomic_t channel_count = ATOMIC_INIT(0); 205 206 /* per-net private data for this module */ 207 static unsigned int ppp_net_id __read_mostly; 208 struct ppp_net { 209 /* units to ppp mapping */ 210 struct idr units_idr; 211 212 /* 213 * all_ppp_mutex protects the units_idr mapping. 214 * It also ensures that finding a ppp unit in the units_idr 215 * map and updating its file.refcnt field is atomic. 216 */ 217 struct mutex all_ppp_mutex; 218 219 /* channels */ 220 struct list_head all_channels; 221 struct list_head new_channels; 222 int last_channel_index; 223 224 /* 225 * all_channels_lock protects all_channels and 226 * last_channel_index, and the atomicity of find 227 * a channel and updating its file.refcnt field. 228 */ 229 spinlock_t all_channels_lock; 230 }; 231 232 /* Get the PPP protocol number from a skb */ 233 #define PPP_PROTO(skb) get_unaligned_be16((skb)->data) 234 235 /* We limit the length of ppp->file.rq to this (arbitrary) value */ 236 #define PPP_MAX_RQLEN 32 237 238 /* 239 * Maximum number of multilink fragments queued up. 240 * This has to be large enough to cope with the maximum latency of 241 * the slowest channel relative to the others. Strictly it should 242 * depend on the number of channels and their characteristics. 243 */ 244 #define PPP_MP_MAX_QLEN 128 245 246 /* Multilink header bits. */ 247 #define B 0x80 /* this fragment begins a packet */ 248 #define E 0x40 /* this fragment ends a packet */ 249 250 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */ 251 #define seq_before(a, b) ((s32)((a) - (b)) < 0) 252 #define seq_after(a, b) ((s32)((a) - (b)) > 0) 253 254 /* Prototypes. */ 255 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 256 struct file *file, unsigned int cmd, unsigned long arg); 257 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb); 258 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb); 259 static void ppp_push(struct ppp *ppp); 260 static void ppp_channel_push(struct channel *pch); 261 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, 262 struct channel *pch); 263 static void ppp_receive_error(struct ppp *ppp); 264 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb); 265 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp, 266 struct sk_buff *skb); 267 #ifdef CONFIG_PPP_MULTILINK 268 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, 269 struct channel *pch); 270 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb); 271 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp); 272 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb); 273 #endif /* CONFIG_PPP_MULTILINK */ 274 static int ppp_set_compress(struct ppp *ppp, struct ppp_option_data *data); 275 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound); 276 static void ppp_ccp_closed(struct ppp *ppp); 277 static struct compressor *find_compressor(int type); 278 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st); 279 static int ppp_create_interface(struct net *net, struct file *file, int *unit); 280 static void init_ppp_file(struct ppp_file *pf, int kind); 281 static void ppp_destroy_interface(struct ppp *ppp); 282 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit); 283 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit); 284 static int ppp_connect_channel(struct channel *pch, int unit); 285 static int ppp_disconnect_channel(struct channel *pch); 286 static void ppp_destroy_channel(struct channel *pch); 287 static int unit_get(struct idr *p, void *ptr); 288 static int unit_set(struct idr *p, void *ptr, int n); 289 static void unit_put(struct idr *p, int n); 290 static void *unit_find(struct idr *p, int n); 291 static void ppp_setup(struct net_device *dev); 292 293 static const struct net_device_ops ppp_netdev_ops; 294 295 static struct class *ppp_class; 296 297 /* per net-namespace data */ 298 static inline struct ppp_net *ppp_pernet(struct net *net) 299 { 300 return net_generic(net, ppp_net_id); 301 } 302 303 /* Translates a PPP protocol number to a NP index (NP == network protocol) */ 304 static inline int proto_to_npindex(int proto) 305 { 306 switch (proto) { 307 case PPP_IP: 308 return NP_IP; 309 case PPP_IPV6: 310 return NP_IPV6; 311 case PPP_IPX: 312 return NP_IPX; 313 case PPP_AT: 314 return NP_AT; 315 case PPP_MPLS_UC: 316 return NP_MPLS_UC; 317 case PPP_MPLS_MC: 318 return NP_MPLS_MC; 319 } 320 return -EINVAL; 321 } 322 323 /* Translates an NP index into a PPP protocol number */ 324 static const int npindex_to_proto[NUM_NP] = { 325 PPP_IP, 326 PPP_IPV6, 327 PPP_IPX, 328 PPP_AT, 329 PPP_MPLS_UC, 330 PPP_MPLS_MC, 331 }; 332 333 /* Translates an ethertype into an NP index */ 334 static inline int ethertype_to_npindex(int ethertype) 335 { 336 switch (ethertype) { 337 case ETH_P_IP: 338 return NP_IP; 339 case ETH_P_IPV6: 340 return NP_IPV6; 341 case ETH_P_IPX: 342 return NP_IPX; 343 case ETH_P_PPPTALK: 344 case ETH_P_ATALK: 345 return NP_AT; 346 case ETH_P_MPLS_UC: 347 return NP_MPLS_UC; 348 case ETH_P_MPLS_MC: 349 return NP_MPLS_MC; 350 } 351 return -1; 352 } 353 354 /* Translates an NP index into an ethertype */ 355 static const int npindex_to_ethertype[NUM_NP] = { 356 ETH_P_IP, 357 ETH_P_IPV6, 358 ETH_P_IPX, 359 ETH_P_PPPTALK, 360 ETH_P_MPLS_UC, 361 ETH_P_MPLS_MC, 362 }; 363 364 /* 365 * Locking shorthand. 366 */ 367 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock) 368 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock) 369 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock) 370 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock) 371 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \ 372 ppp_recv_lock(ppp); } while (0) 373 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \ 374 ppp_xmit_unlock(ppp); } while (0) 375 376 /* 377 * /dev/ppp device routines. 378 * The /dev/ppp device is used by pppd to control the ppp unit. 379 * It supports the read, write, ioctl and poll functions. 380 * Open instances of /dev/ppp can be in one of three states: 381 * unattached, attached to a ppp unit, or attached to a ppp channel. 382 */ 383 static int ppp_open(struct inode *inode, struct file *file) 384 { 385 /* 386 * This could (should?) be enforced by the permissions on /dev/ppp. 387 */ 388 if (!ns_capable(file->f_cred->user_ns, CAP_NET_ADMIN)) 389 return -EPERM; 390 return 0; 391 } 392 393 static int ppp_release(struct inode *unused, struct file *file) 394 { 395 struct ppp_file *pf = file->private_data; 396 struct ppp *ppp; 397 398 if (pf) { 399 file->private_data = NULL; 400 if (pf->kind == INTERFACE) { 401 ppp = PF_TO_PPP(pf); 402 rtnl_lock(); 403 if (file == ppp->owner) 404 unregister_netdevice(ppp->dev); 405 rtnl_unlock(); 406 } 407 if (refcount_dec_and_test(&pf->refcnt)) { 408 switch (pf->kind) { 409 case INTERFACE: 410 ppp_destroy_interface(PF_TO_PPP(pf)); 411 break; 412 case CHANNEL: 413 ppp_destroy_channel(PF_TO_CHANNEL(pf)); 414 break; 415 } 416 } 417 } 418 return 0; 419 } 420 421 static ssize_t ppp_read(struct file *file, char __user *buf, 422 size_t count, loff_t *ppos) 423 { 424 struct ppp_file *pf = file->private_data; 425 DECLARE_WAITQUEUE(wait, current); 426 ssize_t ret; 427 struct sk_buff *skb = NULL; 428 struct iovec iov; 429 struct iov_iter to; 430 431 ret = count; 432 433 if (!pf) 434 return -ENXIO; 435 add_wait_queue(&pf->rwait, &wait); 436 for (;;) { 437 set_current_state(TASK_INTERRUPTIBLE); 438 skb = skb_dequeue(&pf->rq); 439 if (skb) 440 break; 441 ret = 0; 442 if (pf->dead) 443 break; 444 if (pf->kind == INTERFACE) { 445 /* 446 * Return 0 (EOF) on an interface that has no 447 * channels connected, unless it is looping 448 * network traffic (demand mode). 449 */ 450 struct ppp *ppp = PF_TO_PPP(pf); 451 452 ppp_recv_lock(ppp); 453 if (ppp->n_channels == 0 && 454 (ppp->flags & SC_LOOP_TRAFFIC) == 0) { 455 ppp_recv_unlock(ppp); 456 break; 457 } 458 ppp_recv_unlock(ppp); 459 } 460 ret = -EAGAIN; 461 if (file->f_flags & O_NONBLOCK) 462 break; 463 ret = -ERESTARTSYS; 464 if (signal_pending(current)) 465 break; 466 schedule(); 467 } 468 set_current_state(TASK_RUNNING); 469 remove_wait_queue(&pf->rwait, &wait); 470 471 if (!skb) 472 goto out; 473 474 ret = -EOVERFLOW; 475 if (skb->len > count) 476 goto outf; 477 ret = -EFAULT; 478 iov.iov_base = buf; 479 iov.iov_len = count; 480 iov_iter_init(&to, READ, &iov, 1, count); 481 if (skb_copy_datagram_iter(skb, 0, &to, skb->len)) 482 goto outf; 483 ret = skb->len; 484 485 outf: 486 kfree_skb(skb); 487 out: 488 return ret; 489 } 490 491 static ssize_t ppp_write(struct file *file, const char __user *buf, 492 size_t count, loff_t *ppos) 493 { 494 struct ppp_file *pf = file->private_data; 495 struct sk_buff *skb; 496 ssize_t ret; 497 498 if (!pf) 499 return -ENXIO; 500 ret = -ENOMEM; 501 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL); 502 if (!skb) 503 goto out; 504 skb_reserve(skb, pf->hdrlen); 505 ret = -EFAULT; 506 if (copy_from_user(skb_put(skb, count), buf, count)) { 507 kfree_skb(skb); 508 goto out; 509 } 510 511 switch (pf->kind) { 512 case INTERFACE: 513 ppp_xmit_process(PF_TO_PPP(pf), skb); 514 break; 515 case CHANNEL: 516 skb_queue_tail(&pf->xq, skb); 517 ppp_channel_push(PF_TO_CHANNEL(pf)); 518 break; 519 } 520 521 ret = count; 522 523 out: 524 return ret; 525 } 526 527 /* No kernel lock - fine */ 528 static __poll_t ppp_poll(struct file *file, poll_table *wait) 529 { 530 struct ppp_file *pf = file->private_data; 531 __poll_t mask; 532 533 if (!pf) 534 return 0; 535 poll_wait(file, &pf->rwait, wait); 536 mask = EPOLLOUT | EPOLLWRNORM; 537 if (skb_peek(&pf->rq)) 538 mask |= EPOLLIN | EPOLLRDNORM; 539 if (pf->dead) 540 mask |= EPOLLHUP; 541 else if (pf->kind == INTERFACE) { 542 /* see comment in ppp_read */ 543 struct ppp *ppp = PF_TO_PPP(pf); 544 545 ppp_recv_lock(ppp); 546 if (ppp->n_channels == 0 && 547 (ppp->flags & SC_LOOP_TRAFFIC) == 0) 548 mask |= EPOLLIN | EPOLLRDNORM; 549 ppp_recv_unlock(ppp); 550 } 551 552 return mask; 553 } 554 555 #ifdef CONFIG_PPP_FILTER 556 static struct bpf_prog *get_filter(struct sock_fprog *uprog) 557 { 558 struct sock_fprog_kern fprog; 559 struct bpf_prog *res = NULL; 560 int err; 561 562 if (!uprog->len) 563 return NULL; 564 565 /* uprog->len is unsigned short, so no overflow here */ 566 fprog.len = uprog->len; 567 fprog.filter = memdup_user(uprog->filter, 568 uprog->len * sizeof(struct sock_filter)); 569 if (IS_ERR(fprog.filter)) 570 return ERR_CAST(fprog.filter); 571 572 err = bpf_prog_create(&res, &fprog); 573 kfree(fprog.filter); 574 575 return err ? ERR_PTR(err) : res; 576 } 577 578 static struct bpf_prog *ppp_get_filter(struct sock_fprog __user *p) 579 { 580 struct sock_fprog uprog; 581 582 if (copy_from_user(&uprog, p, sizeof(struct sock_fprog))) 583 return ERR_PTR(-EFAULT); 584 return get_filter(&uprog); 585 } 586 587 #ifdef CONFIG_COMPAT 588 struct sock_fprog32 { 589 unsigned short len; 590 compat_caddr_t filter; 591 }; 592 593 #define PPPIOCSPASS32 _IOW('t', 71, struct sock_fprog32) 594 #define PPPIOCSACTIVE32 _IOW('t', 70, struct sock_fprog32) 595 596 static struct bpf_prog *compat_ppp_get_filter(struct sock_fprog32 __user *p) 597 { 598 struct sock_fprog32 uprog32; 599 struct sock_fprog uprog; 600 601 if (copy_from_user(&uprog32, p, sizeof(struct sock_fprog32))) 602 return ERR_PTR(-EFAULT); 603 uprog.len = uprog32.len; 604 uprog.filter = compat_ptr(uprog32.filter); 605 return get_filter(&uprog); 606 } 607 #endif 608 #endif 609 610 /* Bridge one PPP channel to another. 611 * When two channels are bridged, ppp_input on one channel is redirected to 612 * the other's ops->start_xmit handler. 613 * In order to safely bridge channels we must reject channels which are already 614 * part of a bridge instance, or which form part of an existing unit. 615 * Once successfully bridged, each channel holds a reference on the other 616 * to prevent it being freed while the bridge is extant. 617 */ 618 static int ppp_bridge_channels(struct channel *pch, struct channel *pchb) 619 { 620 write_lock_bh(&pch->upl); 621 if (pch->ppp || 622 rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl))) { 623 write_unlock_bh(&pch->upl); 624 return -EALREADY; 625 } 626 rcu_assign_pointer(pch->bridge, pchb); 627 write_unlock_bh(&pch->upl); 628 629 write_lock_bh(&pchb->upl); 630 if (pchb->ppp || 631 rcu_dereference_protected(pchb->bridge, lockdep_is_held(&pchb->upl))) { 632 write_unlock_bh(&pchb->upl); 633 goto err_unset; 634 } 635 rcu_assign_pointer(pchb->bridge, pch); 636 write_unlock_bh(&pchb->upl); 637 638 refcount_inc(&pch->file.refcnt); 639 refcount_inc(&pchb->file.refcnt); 640 641 return 0; 642 643 err_unset: 644 write_lock_bh(&pch->upl); 645 RCU_INIT_POINTER(pch->bridge, NULL); 646 write_unlock_bh(&pch->upl); 647 synchronize_rcu(); 648 return -EALREADY; 649 } 650 651 static int ppp_unbridge_channels(struct channel *pch) 652 { 653 struct channel *pchb, *pchbb; 654 655 write_lock_bh(&pch->upl); 656 pchb = rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl)); 657 if (!pchb) { 658 write_unlock_bh(&pch->upl); 659 return -EINVAL; 660 } 661 RCU_INIT_POINTER(pch->bridge, NULL); 662 write_unlock_bh(&pch->upl); 663 664 /* Only modify pchb if phcb->bridge points back to pch. 665 * If not, it implies that there has been a race unbridging (and possibly 666 * even rebridging) pchb. We should leave pchb alone to avoid either a 667 * refcount underflow, or breaking another established bridge instance. 668 */ 669 write_lock_bh(&pchb->upl); 670 pchbb = rcu_dereference_protected(pchb->bridge, lockdep_is_held(&pchb->upl)); 671 if (pchbb == pch) 672 RCU_INIT_POINTER(pchb->bridge, NULL); 673 write_unlock_bh(&pchb->upl); 674 675 synchronize_rcu(); 676 677 if (pchbb == pch) 678 if (refcount_dec_and_test(&pch->file.refcnt)) 679 ppp_destroy_channel(pch); 680 681 if (refcount_dec_and_test(&pchb->file.refcnt)) 682 ppp_destroy_channel(pchb); 683 684 return 0; 685 } 686 687 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 688 { 689 struct ppp_file *pf; 690 struct ppp *ppp; 691 int err = -EFAULT, val, val2, i; 692 struct ppp_idle32 idle32; 693 struct ppp_idle64 idle64; 694 struct npioctl npi; 695 int unit, cflags; 696 struct slcompress *vj; 697 void __user *argp = (void __user *)arg; 698 int __user *p = argp; 699 700 mutex_lock(&ppp_mutex); 701 702 pf = file->private_data; 703 if (!pf) { 704 err = ppp_unattached_ioctl(current->nsproxy->net_ns, 705 pf, file, cmd, arg); 706 goto out; 707 } 708 709 if (cmd == PPPIOCDETACH) { 710 /* 711 * PPPIOCDETACH is no longer supported as it was heavily broken, 712 * and is only known to have been used by pppd older than 713 * ppp-2.4.2 (released November 2003). 714 */ 715 pr_warn_once("%s (%d) used obsolete PPPIOCDETACH ioctl\n", 716 current->comm, current->pid); 717 err = -EINVAL; 718 goto out; 719 } 720 721 if (pf->kind == CHANNEL) { 722 struct channel *pch, *pchb; 723 struct ppp_channel *chan; 724 struct ppp_net *pn; 725 726 pch = PF_TO_CHANNEL(pf); 727 728 switch (cmd) { 729 case PPPIOCCONNECT: 730 if (get_user(unit, p)) 731 break; 732 err = ppp_connect_channel(pch, unit); 733 break; 734 735 case PPPIOCDISCONN: 736 err = ppp_disconnect_channel(pch); 737 break; 738 739 case PPPIOCBRIDGECHAN: 740 if (get_user(unit, p)) 741 break; 742 err = -ENXIO; 743 pn = ppp_pernet(current->nsproxy->net_ns); 744 spin_lock_bh(&pn->all_channels_lock); 745 pchb = ppp_find_channel(pn, unit); 746 /* Hold a reference to prevent pchb being freed while 747 * we establish the bridge. 748 */ 749 if (pchb) 750 refcount_inc(&pchb->file.refcnt); 751 spin_unlock_bh(&pn->all_channels_lock); 752 if (!pchb) 753 break; 754 err = ppp_bridge_channels(pch, pchb); 755 /* Drop earlier refcount now bridge establishment is complete */ 756 if (refcount_dec_and_test(&pchb->file.refcnt)) 757 ppp_destroy_channel(pchb); 758 break; 759 760 case PPPIOCUNBRIDGECHAN: 761 err = ppp_unbridge_channels(pch); 762 break; 763 764 default: 765 down_read(&pch->chan_sem); 766 chan = pch->chan; 767 err = -ENOTTY; 768 if (chan && chan->ops->ioctl) 769 err = chan->ops->ioctl(chan, cmd, arg); 770 up_read(&pch->chan_sem); 771 } 772 goto out; 773 } 774 775 if (pf->kind != INTERFACE) { 776 /* can't happen */ 777 pr_err("PPP: not interface or channel??\n"); 778 err = -EINVAL; 779 goto out; 780 } 781 782 ppp = PF_TO_PPP(pf); 783 switch (cmd) { 784 case PPPIOCSMRU: 785 if (get_user(val, p)) 786 break; 787 ppp->mru = val; 788 err = 0; 789 break; 790 791 case PPPIOCSFLAGS: 792 if (get_user(val, p)) 793 break; 794 ppp_lock(ppp); 795 cflags = ppp->flags & ~val; 796 #ifdef CONFIG_PPP_MULTILINK 797 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK)) 798 ppp->nextseq = 0; 799 #endif 800 ppp->flags = val & SC_FLAG_BITS; 801 ppp_unlock(ppp); 802 if (cflags & SC_CCP_OPEN) 803 ppp_ccp_closed(ppp); 804 err = 0; 805 break; 806 807 case PPPIOCGFLAGS: 808 val = ppp->flags | ppp->xstate | ppp->rstate; 809 if (put_user(val, p)) 810 break; 811 err = 0; 812 break; 813 814 case PPPIOCSCOMPRESS: 815 { 816 struct ppp_option_data data; 817 if (copy_from_user(&data, argp, sizeof(data))) 818 err = -EFAULT; 819 else 820 err = ppp_set_compress(ppp, &data); 821 break; 822 } 823 case PPPIOCGUNIT: 824 if (put_user(ppp->file.index, p)) 825 break; 826 err = 0; 827 break; 828 829 case PPPIOCSDEBUG: 830 if (get_user(val, p)) 831 break; 832 ppp->debug = val; 833 err = 0; 834 break; 835 836 case PPPIOCGDEBUG: 837 if (put_user(ppp->debug, p)) 838 break; 839 err = 0; 840 break; 841 842 case PPPIOCGIDLE32: 843 idle32.xmit_idle = (jiffies - ppp->last_xmit) / HZ; 844 idle32.recv_idle = (jiffies - ppp->last_recv) / HZ; 845 if (copy_to_user(argp, &idle32, sizeof(idle32))) 846 break; 847 err = 0; 848 break; 849 850 case PPPIOCGIDLE64: 851 idle64.xmit_idle = (jiffies - ppp->last_xmit) / HZ; 852 idle64.recv_idle = (jiffies - ppp->last_recv) / HZ; 853 if (copy_to_user(argp, &idle64, sizeof(idle64))) 854 break; 855 err = 0; 856 break; 857 858 case PPPIOCSMAXCID: 859 if (get_user(val, p)) 860 break; 861 val2 = 15; 862 if ((val >> 16) != 0) { 863 val2 = val >> 16; 864 val &= 0xffff; 865 } 866 vj = slhc_init(val2+1, val+1); 867 if (IS_ERR(vj)) { 868 err = PTR_ERR(vj); 869 break; 870 } 871 ppp_lock(ppp); 872 if (ppp->vj) 873 slhc_free(ppp->vj); 874 ppp->vj = vj; 875 ppp_unlock(ppp); 876 err = 0; 877 break; 878 879 case PPPIOCGNPMODE: 880 case PPPIOCSNPMODE: 881 if (copy_from_user(&npi, argp, sizeof(npi))) 882 break; 883 err = proto_to_npindex(npi.protocol); 884 if (err < 0) 885 break; 886 i = err; 887 if (cmd == PPPIOCGNPMODE) { 888 err = -EFAULT; 889 npi.mode = ppp->npmode[i]; 890 if (copy_to_user(argp, &npi, sizeof(npi))) 891 break; 892 } else { 893 ppp->npmode[i] = npi.mode; 894 /* we may be able to transmit more packets now (??) */ 895 netif_wake_queue(ppp->dev); 896 } 897 err = 0; 898 break; 899 900 #ifdef CONFIG_PPP_FILTER 901 case PPPIOCSPASS: 902 case PPPIOCSACTIVE: 903 { 904 struct bpf_prog *filter = ppp_get_filter(argp); 905 struct bpf_prog **which; 906 907 if (IS_ERR(filter)) { 908 err = PTR_ERR(filter); 909 break; 910 } 911 if (cmd == PPPIOCSPASS) 912 which = &ppp->pass_filter; 913 else 914 which = &ppp->active_filter; 915 ppp_lock(ppp); 916 if (*which) 917 bpf_prog_destroy(*which); 918 *which = filter; 919 ppp_unlock(ppp); 920 err = 0; 921 break; 922 } 923 #endif /* CONFIG_PPP_FILTER */ 924 925 #ifdef CONFIG_PPP_MULTILINK 926 case PPPIOCSMRRU: 927 if (get_user(val, p)) 928 break; 929 ppp_recv_lock(ppp); 930 ppp->mrru = val; 931 ppp_recv_unlock(ppp); 932 err = 0; 933 break; 934 #endif /* CONFIG_PPP_MULTILINK */ 935 936 default: 937 err = -ENOTTY; 938 } 939 940 out: 941 mutex_unlock(&ppp_mutex); 942 943 return err; 944 } 945 946 #ifdef CONFIG_COMPAT 947 struct ppp_option_data32 { 948 compat_uptr_t ptr; 949 u32 length; 950 compat_int_t transmit; 951 }; 952 #define PPPIOCSCOMPRESS32 _IOW('t', 77, struct ppp_option_data32) 953 954 static long ppp_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 955 { 956 struct ppp_file *pf; 957 int err = -ENOIOCTLCMD; 958 void __user *argp = (void __user *)arg; 959 960 mutex_lock(&ppp_mutex); 961 962 pf = file->private_data; 963 if (pf && pf->kind == INTERFACE) { 964 struct ppp *ppp = PF_TO_PPP(pf); 965 switch (cmd) { 966 #ifdef CONFIG_PPP_FILTER 967 case PPPIOCSPASS32: 968 case PPPIOCSACTIVE32: 969 { 970 struct bpf_prog *filter = compat_ppp_get_filter(argp); 971 struct bpf_prog **which; 972 973 if (IS_ERR(filter)) { 974 err = PTR_ERR(filter); 975 break; 976 } 977 if (cmd == PPPIOCSPASS32) 978 which = &ppp->pass_filter; 979 else 980 which = &ppp->active_filter; 981 ppp_lock(ppp); 982 if (*which) 983 bpf_prog_destroy(*which); 984 *which = filter; 985 ppp_unlock(ppp); 986 err = 0; 987 break; 988 } 989 #endif /* CONFIG_PPP_FILTER */ 990 case PPPIOCSCOMPRESS32: 991 { 992 struct ppp_option_data32 data32; 993 if (copy_from_user(&data32, argp, sizeof(data32))) { 994 err = -EFAULT; 995 } else { 996 struct ppp_option_data data = { 997 .ptr = compat_ptr(data32.ptr), 998 .length = data32.length, 999 .transmit = data32.transmit 1000 }; 1001 err = ppp_set_compress(ppp, &data); 1002 } 1003 break; 1004 } 1005 } 1006 } 1007 mutex_unlock(&ppp_mutex); 1008 1009 /* all other commands have compatible arguments */ 1010 if (err == -ENOIOCTLCMD) 1011 err = ppp_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); 1012 1013 return err; 1014 } 1015 #endif 1016 1017 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 1018 struct file *file, unsigned int cmd, unsigned long arg) 1019 { 1020 int unit, err = -EFAULT; 1021 struct ppp *ppp; 1022 struct channel *chan; 1023 struct ppp_net *pn; 1024 int __user *p = (int __user *)arg; 1025 1026 switch (cmd) { 1027 case PPPIOCNEWUNIT: 1028 /* Create a new ppp unit */ 1029 if (get_user(unit, p)) 1030 break; 1031 err = ppp_create_interface(net, file, &unit); 1032 if (err < 0) 1033 break; 1034 1035 err = -EFAULT; 1036 if (put_user(unit, p)) 1037 break; 1038 err = 0; 1039 break; 1040 1041 case PPPIOCATTACH: 1042 /* Attach to an existing ppp unit */ 1043 if (get_user(unit, p)) 1044 break; 1045 err = -ENXIO; 1046 pn = ppp_pernet(net); 1047 mutex_lock(&pn->all_ppp_mutex); 1048 ppp = ppp_find_unit(pn, unit); 1049 if (ppp) { 1050 refcount_inc(&ppp->file.refcnt); 1051 file->private_data = &ppp->file; 1052 err = 0; 1053 } 1054 mutex_unlock(&pn->all_ppp_mutex); 1055 break; 1056 1057 case PPPIOCATTCHAN: 1058 if (get_user(unit, p)) 1059 break; 1060 err = -ENXIO; 1061 pn = ppp_pernet(net); 1062 spin_lock_bh(&pn->all_channels_lock); 1063 chan = ppp_find_channel(pn, unit); 1064 if (chan) { 1065 refcount_inc(&chan->file.refcnt); 1066 file->private_data = &chan->file; 1067 err = 0; 1068 } 1069 spin_unlock_bh(&pn->all_channels_lock); 1070 break; 1071 1072 default: 1073 err = -ENOTTY; 1074 } 1075 1076 return err; 1077 } 1078 1079 static const struct file_operations ppp_device_fops = { 1080 .owner = THIS_MODULE, 1081 .read = ppp_read, 1082 .write = ppp_write, 1083 .poll = ppp_poll, 1084 .unlocked_ioctl = ppp_ioctl, 1085 #ifdef CONFIG_COMPAT 1086 .compat_ioctl = ppp_compat_ioctl, 1087 #endif 1088 .open = ppp_open, 1089 .release = ppp_release, 1090 .llseek = noop_llseek, 1091 }; 1092 1093 static __net_init int ppp_init_net(struct net *net) 1094 { 1095 struct ppp_net *pn = net_generic(net, ppp_net_id); 1096 1097 idr_init(&pn->units_idr); 1098 mutex_init(&pn->all_ppp_mutex); 1099 1100 INIT_LIST_HEAD(&pn->all_channels); 1101 INIT_LIST_HEAD(&pn->new_channels); 1102 1103 spin_lock_init(&pn->all_channels_lock); 1104 1105 return 0; 1106 } 1107 1108 static __net_exit void ppp_exit_net(struct net *net) 1109 { 1110 struct ppp_net *pn = net_generic(net, ppp_net_id); 1111 struct net_device *dev; 1112 struct net_device *aux; 1113 struct ppp *ppp; 1114 LIST_HEAD(list); 1115 int id; 1116 1117 rtnl_lock(); 1118 for_each_netdev_safe(net, dev, aux) { 1119 if (dev->netdev_ops == &ppp_netdev_ops) 1120 unregister_netdevice_queue(dev, &list); 1121 } 1122 1123 idr_for_each_entry(&pn->units_idr, ppp, id) 1124 /* Skip devices already unregistered by previous loop */ 1125 if (!net_eq(dev_net(ppp->dev), net)) 1126 unregister_netdevice_queue(ppp->dev, &list); 1127 1128 unregister_netdevice_many(&list); 1129 rtnl_unlock(); 1130 1131 mutex_destroy(&pn->all_ppp_mutex); 1132 idr_destroy(&pn->units_idr); 1133 WARN_ON_ONCE(!list_empty(&pn->all_channels)); 1134 WARN_ON_ONCE(!list_empty(&pn->new_channels)); 1135 } 1136 1137 static struct pernet_operations ppp_net_ops = { 1138 .init = ppp_init_net, 1139 .exit = ppp_exit_net, 1140 .id = &ppp_net_id, 1141 .size = sizeof(struct ppp_net), 1142 }; 1143 1144 static int ppp_unit_register(struct ppp *ppp, int unit, bool ifname_is_set) 1145 { 1146 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 1147 int ret; 1148 1149 mutex_lock(&pn->all_ppp_mutex); 1150 1151 if (unit < 0) { 1152 ret = unit_get(&pn->units_idr, ppp); 1153 if (ret < 0) 1154 goto err; 1155 } else { 1156 /* Caller asked for a specific unit number. Fail with -EEXIST 1157 * if unavailable. For backward compatibility, return -EEXIST 1158 * too if idr allocation fails; this makes pppd retry without 1159 * requesting a specific unit number. 1160 */ 1161 if (unit_find(&pn->units_idr, unit)) { 1162 ret = -EEXIST; 1163 goto err; 1164 } 1165 ret = unit_set(&pn->units_idr, ppp, unit); 1166 if (ret < 0) { 1167 /* Rewrite error for backward compatibility */ 1168 ret = -EEXIST; 1169 goto err; 1170 } 1171 } 1172 ppp->file.index = ret; 1173 1174 if (!ifname_is_set) 1175 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ppp->file.index); 1176 1177 mutex_unlock(&pn->all_ppp_mutex); 1178 1179 ret = register_netdevice(ppp->dev); 1180 if (ret < 0) 1181 goto err_unit; 1182 1183 atomic_inc(&ppp_unit_count); 1184 1185 return 0; 1186 1187 err_unit: 1188 mutex_lock(&pn->all_ppp_mutex); 1189 unit_put(&pn->units_idr, ppp->file.index); 1190 err: 1191 mutex_unlock(&pn->all_ppp_mutex); 1192 1193 return ret; 1194 } 1195 1196 static int ppp_dev_configure(struct net *src_net, struct net_device *dev, 1197 const struct ppp_config *conf) 1198 { 1199 struct ppp *ppp = netdev_priv(dev); 1200 int indx; 1201 int err; 1202 int cpu; 1203 1204 ppp->dev = dev; 1205 ppp->ppp_net = src_net; 1206 ppp->mru = PPP_MRU; 1207 ppp->owner = conf->file; 1208 1209 init_ppp_file(&ppp->file, INTERFACE); 1210 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */ 1211 1212 for (indx = 0; indx < NUM_NP; ++indx) 1213 ppp->npmode[indx] = NPMODE_PASS; 1214 INIT_LIST_HEAD(&ppp->channels); 1215 spin_lock_init(&ppp->rlock); 1216 spin_lock_init(&ppp->wlock); 1217 1218 ppp->xmit_recursion = alloc_percpu(int); 1219 if (!ppp->xmit_recursion) { 1220 err = -ENOMEM; 1221 goto err1; 1222 } 1223 for_each_possible_cpu(cpu) 1224 (*per_cpu_ptr(ppp->xmit_recursion, cpu)) = 0; 1225 1226 #ifdef CONFIG_PPP_MULTILINK 1227 ppp->minseq = -1; 1228 skb_queue_head_init(&ppp->mrq); 1229 #endif /* CONFIG_PPP_MULTILINK */ 1230 #ifdef CONFIG_PPP_FILTER 1231 ppp->pass_filter = NULL; 1232 ppp->active_filter = NULL; 1233 #endif /* CONFIG_PPP_FILTER */ 1234 1235 err = ppp_unit_register(ppp, conf->unit, conf->ifname_is_set); 1236 if (err < 0) 1237 goto err2; 1238 1239 conf->file->private_data = &ppp->file; 1240 1241 return 0; 1242 err2: 1243 free_percpu(ppp->xmit_recursion); 1244 err1: 1245 return err; 1246 } 1247 1248 static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = { 1249 [IFLA_PPP_DEV_FD] = { .type = NLA_S32 }, 1250 }; 1251 1252 static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[], 1253 struct netlink_ext_ack *extack) 1254 { 1255 if (!data) 1256 return -EINVAL; 1257 1258 if (!data[IFLA_PPP_DEV_FD]) 1259 return -EINVAL; 1260 if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0) 1261 return -EBADF; 1262 1263 return 0; 1264 } 1265 1266 static int ppp_nl_newlink(struct net *src_net, struct net_device *dev, 1267 struct nlattr *tb[], struct nlattr *data[], 1268 struct netlink_ext_ack *extack) 1269 { 1270 struct ppp_config conf = { 1271 .unit = -1, 1272 .ifname_is_set = true, 1273 }; 1274 struct file *file; 1275 int err; 1276 1277 file = fget(nla_get_s32(data[IFLA_PPP_DEV_FD])); 1278 if (!file) 1279 return -EBADF; 1280 1281 /* rtnl_lock is already held here, but ppp_create_interface() locks 1282 * ppp_mutex before holding rtnl_lock. Using mutex_trylock() avoids 1283 * possible deadlock due to lock order inversion, at the cost of 1284 * pushing the problem back to userspace. 1285 */ 1286 if (!mutex_trylock(&ppp_mutex)) { 1287 err = -EBUSY; 1288 goto out; 1289 } 1290 1291 if (file->f_op != &ppp_device_fops || file->private_data) { 1292 err = -EBADF; 1293 goto out_unlock; 1294 } 1295 1296 conf.file = file; 1297 1298 /* Don't use device name generated by the rtnetlink layer when ifname 1299 * isn't specified. Let ppp_dev_configure() set the device name using 1300 * the PPP unit identifer as suffix (i.e. ppp<unit_id>). This allows 1301 * userspace to infer the device name using to the PPPIOCGUNIT ioctl. 1302 */ 1303 if (!tb[IFLA_IFNAME]) 1304 conf.ifname_is_set = false; 1305 1306 err = ppp_dev_configure(src_net, dev, &conf); 1307 1308 out_unlock: 1309 mutex_unlock(&ppp_mutex); 1310 out: 1311 fput(file); 1312 1313 return err; 1314 } 1315 1316 static void ppp_nl_dellink(struct net_device *dev, struct list_head *head) 1317 { 1318 unregister_netdevice_queue(dev, head); 1319 } 1320 1321 static size_t ppp_nl_get_size(const struct net_device *dev) 1322 { 1323 return 0; 1324 } 1325 1326 static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev) 1327 { 1328 return 0; 1329 } 1330 1331 static struct net *ppp_nl_get_link_net(const struct net_device *dev) 1332 { 1333 struct ppp *ppp = netdev_priv(dev); 1334 1335 return ppp->ppp_net; 1336 } 1337 1338 static struct rtnl_link_ops ppp_link_ops __read_mostly = { 1339 .kind = "ppp", 1340 .maxtype = IFLA_PPP_MAX, 1341 .policy = ppp_nl_policy, 1342 .priv_size = sizeof(struct ppp), 1343 .setup = ppp_setup, 1344 .validate = ppp_nl_validate, 1345 .newlink = ppp_nl_newlink, 1346 .dellink = ppp_nl_dellink, 1347 .get_size = ppp_nl_get_size, 1348 .fill_info = ppp_nl_fill_info, 1349 .get_link_net = ppp_nl_get_link_net, 1350 }; 1351 1352 #define PPP_MAJOR 108 1353 1354 /* Called at boot time if ppp is compiled into the kernel, 1355 or at module load time (from init_module) if compiled as a module. */ 1356 static int __init ppp_init(void) 1357 { 1358 int err; 1359 1360 pr_info("PPP generic driver version " PPP_VERSION "\n"); 1361 1362 err = register_pernet_device(&ppp_net_ops); 1363 if (err) { 1364 pr_err("failed to register PPP pernet device (%d)\n", err); 1365 goto out; 1366 } 1367 1368 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops); 1369 if (err) { 1370 pr_err("failed to register PPP device (%d)\n", err); 1371 goto out_net; 1372 } 1373 1374 ppp_class = class_create(THIS_MODULE, "ppp"); 1375 if (IS_ERR(ppp_class)) { 1376 err = PTR_ERR(ppp_class); 1377 goto out_chrdev; 1378 } 1379 1380 err = rtnl_link_register(&ppp_link_ops); 1381 if (err) { 1382 pr_err("failed to register rtnetlink PPP handler\n"); 1383 goto out_class; 1384 } 1385 1386 /* not a big deal if we fail here :-) */ 1387 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp"); 1388 1389 return 0; 1390 1391 out_class: 1392 class_destroy(ppp_class); 1393 out_chrdev: 1394 unregister_chrdev(PPP_MAJOR, "ppp"); 1395 out_net: 1396 unregister_pernet_device(&ppp_net_ops); 1397 out: 1398 return err; 1399 } 1400 1401 /* 1402 * Network interface unit routines. 1403 */ 1404 static netdev_tx_t 1405 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev) 1406 { 1407 struct ppp *ppp = netdev_priv(dev); 1408 int npi, proto; 1409 unsigned char *pp; 1410 1411 npi = ethertype_to_npindex(ntohs(skb->protocol)); 1412 if (npi < 0) 1413 goto outf; 1414 1415 /* Drop, accept or reject the packet */ 1416 switch (ppp->npmode[npi]) { 1417 case NPMODE_PASS: 1418 break; 1419 case NPMODE_QUEUE: 1420 /* it would be nice to have a way to tell the network 1421 system to queue this one up for later. */ 1422 goto outf; 1423 case NPMODE_DROP: 1424 case NPMODE_ERROR: 1425 goto outf; 1426 } 1427 1428 /* Put the 2-byte PPP protocol number on the front, 1429 making sure there is room for the address and control fields. */ 1430 if (skb_cow_head(skb, PPP_HDRLEN)) 1431 goto outf; 1432 1433 pp = skb_push(skb, 2); 1434 proto = npindex_to_proto[npi]; 1435 put_unaligned_be16(proto, pp); 1436 1437 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev))); 1438 ppp_xmit_process(ppp, skb); 1439 1440 return NETDEV_TX_OK; 1441 1442 outf: 1443 kfree_skb(skb); 1444 ++dev->stats.tx_dropped; 1445 return NETDEV_TX_OK; 1446 } 1447 1448 static int 1449 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 1450 { 1451 struct ppp *ppp = netdev_priv(dev); 1452 int err = -EFAULT; 1453 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data; 1454 struct ppp_stats stats; 1455 struct ppp_comp_stats cstats; 1456 char *vers; 1457 1458 switch (cmd) { 1459 case SIOCGPPPSTATS: 1460 ppp_get_stats(ppp, &stats); 1461 if (copy_to_user(addr, &stats, sizeof(stats))) 1462 break; 1463 err = 0; 1464 break; 1465 1466 case SIOCGPPPCSTATS: 1467 memset(&cstats, 0, sizeof(cstats)); 1468 if (ppp->xc_state) 1469 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c); 1470 if (ppp->rc_state) 1471 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d); 1472 if (copy_to_user(addr, &cstats, sizeof(cstats))) 1473 break; 1474 err = 0; 1475 break; 1476 1477 case SIOCGPPPVER: 1478 vers = PPP_VERSION; 1479 if (copy_to_user(addr, vers, strlen(vers) + 1)) 1480 break; 1481 err = 0; 1482 break; 1483 1484 default: 1485 err = -EINVAL; 1486 } 1487 1488 return err; 1489 } 1490 1491 static void 1492 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64) 1493 { 1494 struct ppp *ppp = netdev_priv(dev); 1495 1496 ppp_recv_lock(ppp); 1497 stats64->rx_packets = ppp->stats64.rx_packets; 1498 stats64->rx_bytes = ppp->stats64.rx_bytes; 1499 ppp_recv_unlock(ppp); 1500 1501 ppp_xmit_lock(ppp); 1502 stats64->tx_packets = ppp->stats64.tx_packets; 1503 stats64->tx_bytes = ppp->stats64.tx_bytes; 1504 ppp_xmit_unlock(ppp); 1505 1506 stats64->rx_errors = dev->stats.rx_errors; 1507 stats64->tx_errors = dev->stats.tx_errors; 1508 stats64->rx_dropped = dev->stats.rx_dropped; 1509 stats64->tx_dropped = dev->stats.tx_dropped; 1510 stats64->rx_length_errors = dev->stats.rx_length_errors; 1511 } 1512 1513 static int ppp_dev_init(struct net_device *dev) 1514 { 1515 struct ppp *ppp; 1516 1517 netdev_lockdep_set_classes(dev); 1518 1519 ppp = netdev_priv(dev); 1520 /* Let the netdevice take a reference on the ppp file. This ensures 1521 * that ppp_destroy_interface() won't run before the device gets 1522 * unregistered. 1523 */ 1524 refcount_inc(&ppp->file.refcnt); 1525 1526 return 0; 1527 } 1528 1529 static void ppp_dev_uninit(struct net_device *dev) 1530 { 1531 struct ppp *ppp = netdev_priv(dev); 1532 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 1533 1534 ppp_lock(ppp); 1535 ppp->closing = 1; 1536 ppp_unlock(ppp); 1537 1538 mutex_lock(&pn->all_ppp_mutex); 1539 unit_put(&pn->units_idr, ppp->file.index); 1540 mutex_unlock(&pn->all_ppp_mutex); 1541 1542 ppp->owner = NULL; 1543 1544 ppp->file.dead = 1; 1545 wake_up_interruptible(&ppp->file.rwait); 1546 } 1547 1548 static void ppp_dev_priv_destructor(struct net_device *dev) 1549 { 1550 struct ppp *ppp; 1551 1552 ppp = netdev_priv(dev); 1553 if (refcount_dec_and_test(&ppp->file.refcnt)) 1554 ppp_destroy_interface(ppp); 1555 } 1556 1557 static const struct net_device_ops ppp_netdev_ops = { 1558 .ndo_init = ppp_dev_init, 1559 .ndo_uninit = ppp_dev_uninit, 1560 .ndo_start_xmit = ppp_start_xmit, 1561 .ndo_do_ioctl = ppp_net_ioctl, 1562 .ndo_get_stats64 = ppp_get_stats64, 1563 }; 1564 1565 static struct device_type ppp_type = { 1566 .name = "ppp", 1567 }; 1568 1569 static void ppp_setup(struct net_device *dev) 1570 { 1571 dev->netdev_ops = &ppp_netdev_ops; 1572 SET_NETDEV_DEVTYPE(dev, &ppp_type); 1573 1574 dev->features |= NETIF_F_LLTX; 1575 1576 dev->hard_header_len = PPP_HDRLEN; 1577 dev->mtu = PPP_MRU; 1578 dev->addr_len = 0; 1579 dev->tx_queue_len = 3; 1580 dev->type = ARPHRD_PPP; 1581 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 1582 dev->priv_destructor = ppp_dev_priv_destructor; 1583 netif_keep_dst(dev); 1584 } 1585 1586 /* 1587 * Transmit-side routines. 1588 */ 1589 1590 /* Called to do any work queued up on the transmit side that can now be done */ 1591 static void __ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb) 1592 { 1593 ppp_xmit_lock(ppp); 1594 if (!ppp->closing) { 1595 ppp_push(ppp); 1596 1597 if (skb) 1598 skb_queue_tail(&ppp->file.xq, skb); 1599 while (!ppp->xmit_pending && 1600 (skb = skb_dequeue(&ppp->file.xq))) 1601 ppp_send_frame(ppp, skb); 1602 /* If there's no work left to do, tell the core net 1603 code that we can accept some more. */ 1604 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq)) 1605 netif_wake_queue(ppp->dev); 1606 else 1607 netif_stop_queue(ppp->dev); 1608 } else { 1609 kfree_skb(skb); 1610 } 1611 ppp_xmit_unlock(ppp); 1612 } 1613 1614 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb) 1615 { 1616 local_bh_disable(); 1617 1618 if (unlikely(*this_cpu_ptr(ppp->xmit_recursion))) 1619 goto err; 1620 1621 (*this_cpu_ptr(ppp->xmit_recursion))++; 1622 __ppp_xmit_process(ppp, skb); 1623 (*this_cpu_ptr(ppp->xmit_recursion))--; 1624 1625 local_bh_enable(); 1626 1627 return; 1628 1629 err: 1630 local_bh_enable(); 1631 1632 kfree_skb(skb); 1633 1634 if (net_ratelimit()) 1635 netdev_err(ppp->dev, "recursion detected\n"); 1636 } 1637 1638 static inline struct sk_buff * 1639 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) 1640 { 1641 struct sk_buff *new_skb; 1642 int len; 1643 int new_skb_size = ppp->dev->mtu + 1644 ppp->xcomp->comp_extra + ppp->dev->hard_header_len; 1645 int compressor_skb_size = ppp->dev->mtu + 1646 ppp->xcomp->comp_extra + PPP_HDRLEN; 1647 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC); 1648 if (!new_skb) { 1649 if (net_ratelimit()) 1650 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n"); 1651 return NULL; 1652 } 1653 if (ppp->dev->hard_header_len > PPP_HDRLEN) 1654 skb_reserve(new_skb, 1655 ppp->dev->hard_header_len - PPP_HDRLEN); 1656 1657 /* compressor still expects A/C bytes in hdr */ 1658 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, 1659 new_skb->data, skb->len + 2, 1660 compressor_skb_size); 1661 if (len > 0 && (ppp->flags & SC_CCP_UP)) { 1662 consume_skb(skb); 1663 skb = new_skb; 1664 skb_put(skb, len); 1665 skb_pull(skb, 2); /* pull off A/C bytes */ 1666 } else if (len == 0) { 1667 /* didn't compress, or CCP not up yet */ 1668 consume_skb(new_skb); 1669 new_skb = skb; 1670 } else { 1671 /* 1672 * (len < 0) 1673 * MPPE requires that we do not send unencrypted 1674 * frames. The compressor will return -1 if we 1675 * should drop the frame. We cannot simply test 1676 * the compress_proto because MPPE and MPPC share 1677 * the same number. 1678 */ 1679 if (net_ratelimit()) 1680 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n"); 1681 kfree_skb(skb); 1682 consume_skb(new_skb); 1683 new_skb = NULL; 1684 } 1685 return new_skb; 1686 } 1687 1688 /* 1689 * Compress and send a frame. 1690 * The caller should have locked the xmit path, 1691 * and xmit_pending should be 0. 1692 */ 1693 static void 1694 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) 1695 { 1696 int proto = PPP_PROTO(skb); 1697 struct sk_buff *new_skb; 1698 int len; 1699 unsigned char *cp; 1700 1701 if (proto < 0x8000) { 1702 #ifdef CONFIG_PPP_FILTER 1703 /* check if we should pass this packet */ 1704 /* the filter instructions are constructed assuming 1705 a four-byte PPP header on each packet */ 1706 *(u8 *)skb_push(skb, 2) = 1; 1707 if (ppp->pass_filter && 1708 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 1709 if (ppp->debug & 1) 1710 netdev_printk(KERN_DEBUG, ppp->dev, 1711 "PPP: outbound frame " 1712 "not passed\n"); 1713 kfree_skb(skb); 1714 return; 1715 } 1716 /* if this packet passes the active filter, record the time */ 1717 if (!(ppp->active_filter && 1718 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 1719 ppp->last_xmit = jiffies; 1720 skb_pull(skb, 2); 1721 #else 1722 /* for data packets, record the time */ 1723 ppp->last_xmit = jiffies; 1724 #endif /* CONFIG_PPP_FILTER */ 1725 } 1726 1727 ++ppp->stats64.tx_packets; 1728 ppp->stats64.tx_bytes += skb->len - 2; 1729 1730 switch (proto) { 1731 case PPP_IP: 1732 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0) 1733 break; 1734 /* try to do VJ TCP header compression */ 1735 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2, 1736 GFP_ATOMIC); 1737 if (!new_skb) { 1738 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n"); 1739 goto drop; 1740 } 1741 skb_reserve(new_skb, ppp->dev->hard_header_len - 2); 1742 cp = skb->data + 2; 1743 len = slhc_compress(ppp->vj, cp, skb->len - 2, 1744 new_skb->data + 2, &cp, 1745 !(ppp->flags & SC_NO_TCP_CCID)); 1746 if (cp == skb->data + 2) { 1747 /* didn't compress */ 1748 consume_skb(new_skb); 1749 } else { 1750 if (cp[0] & SL_TYPE_COMPRESSED_TCP) { 1751 proto = PPP_VJC_COMP; 1752 cp[0] &= ~SL_TYPE_COMPRESSED_TCP; 1753 } else { 1754 proto = PPP_VJC_UNCOMP; 1755 cp[0] = skb->data[2]; 1756 } 1757 consume_skb(skb); 1758 skb = new_skb; 1759 cp = skb_put(skb, len + 2); 1760 cp[0] = 0; 1761 cp[1] = proto; 1762 } 1763 break; 1764 1765 case PPP_CCP: 1766 /* peek at outbound CCP frames */ 1767 ppp_ccp_peek(ppp, skb, 0); 1768 break; 1769 } 1770 1771 /* try to do packet compression */ 1772 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state && 1773 proto != PPP_LCP && proto != PPP_CCP) { 1774 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) { 1775 if (net_ratelimit()) 1776 netdev_err(ppp->dev, 1777 "ppp: compression required but " 1778 "down - pkt dropped.\n"); 1779 goto drop; 1780 } 1781 skb = pad_compress_skb(ppp, skb); 1782 if (!skb) 1783 goto drop; 1784 } 1785 1786 /* 1787 * If we are waiting for traffic (demand dialling), 1788 * queue it up for pppd to receive. 1789 */ 1790 if (ppp->flags & SC_LOOP_TRAFFIC) { 1791 if (ppp->file.rq.qlen > PPP_MAX_RQLEN) 1792 goto drop; 1793 skb_queue_tail(&ppp->file.rq, skb); 1794 wake_up_interruptible(&ppp->file.rwait); 1795 return; 1796 } 1797 1798 ppp->xmit_pending = skb; 1799 ppp_push(ppp); 1800 return; 1801 1802 drop: 1803 kfree_skb(skb); 1804 ++ppp->dev->stats.tx_errors; 1805 } 1806 1807 /* 1808 * Try to send the frame in xmit_pending. 1809 * The caller should have the xmit path locked. 1810 */ 1811 static void 1812 ppp_push(struct ppp *ppp) 1813 { 1814 struct list_head *list; 1815 struct channel *pch; 1816 struct sk_buff *skb = ppp->xmit_pending; 1817 1818 if (!skb) 1819 return; 1820 1821 list = &ppp->channels; 1822 if (list_empty(list)) { 1823 /* nowhere to send the packet, just drop it */ 1824 ppp->xmit_pending = NULL; 1825 kfree_skb(skb); 1826 return; 1827 } 1828 1829 if ((ppp->flags & SC_MULTILINK) == 0) { 1830 /* not doing multilink: send it down the first channel */ 1831 list = list->next; 1832 pch = list_entry(list, struct channel, clist); 1833 1834 spin_lock(&pch->downl); 1835 if (pch->chan) { 1836 if (pch->chan->ops->start_xmit(pch->chan, skb)) 1837 ppp->xmit_pending = NULL; 1838 } else { 1839 /* channel got unregistered */ 1840 kfree_skb(skb); 1841 ppp->xmit_pending = NULL; 1842 } 1843 spin_unlock(&pch->downl); 1844 return; 1845 } 1846 1847 #ifdef CONFIG_PPP_MULTILINK 1848 /* Multilink: fragment the packet over as many links 1849 as can take the packet at the moment. */ 1850 if (!ppp_mp_explode(ppp, skb)) 1851 return; 1852 #endif /* CONFIG_PPP_MULTILINK */ 1853 1854 ppp->xmit_pending = NULL; 1855 kfree_skb(skb); 1856 } 1857 1858 #ifdef CONFIG_PPP_MULTILINK 1859 static bool mp_protocol_compress __read_mostly = true; 1860 module_param(mp_protocol_compress, bool, 0644); 1861 MODULE_PARM_DESC(mp_protocol_compress, 1862 "compress protocol id in multilink fragments"); 1863 1864 /* 1865 * Divide a packet to be transmitted into fragments and 1866 * send them out the individual links. 1867 */ 1868 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb) 1869 { 1870 int len, totlen; 1871 int i, bits, hdrlen, mtu; 1872 int flen; 1873 int navail, nfree, nzero; 1874 int nbigger; 1875 int totspeed; 1876 int totfree; 1877 unsigned char *p, *q; 1878 struct list_head *list; 1879 struct channel *pch; 1880 struct sk_buff *frag; 1881 struct ppp_channel *chan; 1882 1883 totspeed = 0; /*total bitrate of the bundle*/ 1884 nfree = 0; /* # channels which have no packet already queued */ 1885 navail = 0; /* total # of usable channels (not deregistered) */ 1886 nzero = 0; /* number of channels with zero speed associated*/ 1887 totfree = 0; /*total # of channels available and 1888 *having no queued packets before 1889 *starting the fragmentation*/ 1890 1891 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1892 i = 0; 1893 list_for_each_entry(pch, &ppp->channels, clist) { 1894 if (pch->chan) { 1895 pch->avail = 1; 1896 navail++; 1897 pch->speed = pch->chan->speed; 1898 } else { 1899 pch->avail = 0; 1900 } 1901 if (pch->avail) { 1902 if (skb_queue_empty(&pch->file.xq) || 1903 !pch->had_frag) { 1904 if (pch->speed == 0) 1905 nzero++; 1906 else 1907 totspeed += pch->speed; 1908 1909 pch->avail = 2; 1910 ++nfree; 1911 ++totfree; 1912 } 1913 if (!pch->had_frag && i < ppp->nxchan) 1914 ppp->nxchan = i; 1915 } 1916 ++i; 1917 } 1918 /* 1919 * Don't start sending this packet unless at least half of 1920 * the channels are free. This gives much better TCP 1921 * performance if we have a lot of channels. 1922 */ 1923 if (nfree == 0 || nfree < navail / 2) 1924 return 0; /* can't take now, leave it in xmit_pending */ 1925 1926 /* Do protocol field compression */ 1927 p = skb->data; 1928 len = skb->len; 1929 if (*p == 0 && mp_protocol_compress) { 1930 ++p; 1931 --len; 1932 } 1933 1934 totlen = len; 1935 nbigger = len % nfree; 1936 1937 /* skip to the channel after the one we last used 1938 and start at that one */ 1939 list = &ppp->channels; 1940 for (i = 0; i < ppp->nxchan; ++i) { 1941 list = list->next; 1942 if (list == &ppp->channels) { 1943 i = 0; 1944 break; 1945 } 1946 } 1947 1948 /* create a fragment for each channel */ 1949 bits = B; 1950 while (len > 0) { 1951 list = list->next; 1952 if (list == &ppp->channels) { 1953 i = 0; 1954 continue; 1955 } 1956 pch = list_entry(list, struct channel, clist); 1957 ++i; 1958 if (!pch->avail) 1959 continue; 1960 1961 /* 1962 * Skip this channel if it has a fragment pending already and 1963 * we haven't given a fragment to all of the free channels. 1964 */ 1965 if (pch->avail == 1) { 1966 if (nfree > 0) 1967 continue; 1968 } else { 1969 pch->avail = 1; 1970 } 1971 1972 /* check the channel's mtu and whether it is still attached. */ 1973 spin_lock(&pch->downl); 1974 if (pch->chan == NULL) { 1975 /* can't use this channel, it's being deregistered */ 1976 if (pch->speed == 0) 1977 nzero--; 1978 else 1979 totspeed -= pch->speed; 1980 1981 spin_unlock(&pch->downl); 1982 pch->avail = 0; 1983 totlen = len; 1984 totfree--; 1985 nfree--; 1986 if (--navail == 0) 1987 break; 1988 continue; 1989 } 1990 1991 /* 1992 *if the channel speed is not set divide 1993 *the packet evenly among the free channels; 1994 *otherwise divide it according to the speed 1995 *of the channel we are going to transmit on 1996 */ 1997 flen = len; 1998 if (nfree > 0) { 1999 if (pch->speed == 0) { 2000 flen = len/nfree; 2001 if (nbigger > 0) { 2002 flen++; 2003 nbigger--; 2004 } 2005 } else { 2006 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) / 2007 ((totspeed*totfree)/pch->speed)) - hdrlen; 2008 if (nbigger > 0) { 2009 flen += ((totfree - nzero)*pch->speed)/totspeed; 2010 nbigger -= ((totfree - nzero)*pch->speed)/ 2011 totspeed; 2012 } 2013 } 2014 nfree--; 2015 } 2016 2017 /* 2018 *check if we are on the last channel or 2019 *we exceded the length of the data to 2020 *fragment 2021 */ 2022 if ((nfree <= 0) || (flen > len)) 2023 flen = len; 2024 /* 2025 *it is not worth to tx on slow channels: 2026 *in that case from the resulting flen according to the 2027 *above formula will be equal or less than zero. 2028 *Skip the channel in this case 2029 */ 2030 if (flen <= 0) { 2031 pch->avail = 2; 2032 spin_unlock(&pch->downl); 2033 continue; 2034 } 2035 2036 /* 2037 * hdrlen includes the 2-byte PPP protocol field, but the 2038 * MTU counts only the payload excluding the protocol field. 2039 * (RFC1661 Section 2) 2040 */ 2041 mtu = pch->chan->mtu - (hdrlen - 2); 2042 if (mtu < 4) 2043 mtu = 4; 2044 if (flen > mtu) 2045 flen = mtu; 2046 if (flen == len) 2047 bits |= E; 2048 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC); 2049 if (!frag) 2050 goto noskb; 2051 q = skb_put(frag, flen + hdrlen); 2052 2053 /* make the MP header */ 2054 put_unaligned_be16(PPP_MP, q); 2055 if (ppp->flags & SC_MP_XSHORTSEQ) { 2056 q[2] = bits + ((ppp->nxseq >> 8) & 0xf); 2057 q[3] = ppp->nxseq; 2058 } else { 2059 q[2] = bits; 2060 q[3] = ppp->nxseq >> 16; 2061 q[4] = ppp->nxseq >> 8; 2062 q[5] = ppp->nxseq; 2063 } 2064 2065 memcpy(q + hdrlen, p, flen); 2066 2067 /* try to send it down the channel */ 2068 chan = pch->chan; 2069 if (!skb_queue_empty(&pch->file.xq) || 2070 !chan->ops->start_xmit(chan, frag)) 2071 skb_queue_tail(&pch->file.xq, frag); 2072 pch->had_frag = 1; 2073 p += flen; 2074 len -= flen; 2075 ++ppp->nxseq; 2076 bits = 0; 2077 spin_unlock(&pch->downl); 2078 } 2079 ppp->nxchan = i; 2080 2081 return 1; 2082 2083 noskb: 2084 spin_unlock(&pch->downl); 2085 if (ppp->debug & 1) 2086 netdev_err(ppp->dev, "PPP: no memory (fragment)\n"); 2087 ++ppp->dev->stats.tx_errors; 2088 ++ppp->nxseq; 2089 return 1; /* abandon the frame */ 2090 } 2091 #endif /* CONFIG_PPP_MULTILINK */ 2092 2093 /* Try to send data out on a channel */ 2094 static void __ppp_channel_push(struct channel *pch) 2095 { 2096 struct sk_buff *skb; 2097 struct ppp *ppp; 2098 2099 spin_lock(&pch->downl); 2100 if (pch->chan) { 2101 while (!skb_queue_empty(&pch->file.xq)) { 2102 skb = skb_dequeue(&pch->file.xq); 2103 if (!pch->chan->ops->start_xmit(pch->chan, skb)) { 2104 /* put the packet back and try again later */ 2105 skb_queue_head(&pch->file.xq, skb); 2106 break; 2107 } 2108 } 2109 } else { 2110 /* channel got deregistered */ 2111 skb_queue_purge(&pch->file.xq); 2112 } 2113 spin_unlock(&pch->downl); 2114 /* see if there is anything from the attached unit to be sent */ 2115 if (skb_queue_empty(&pch->file.xq)) { 2116 ppp = pch->ppp; 2117 if (ppp) 2118 __ppp_xmit_process(ppp, NULL); 2119 } 2120 } 2121 2122 static void ppp_channel_push(struct channel *pch) 2123 { 2124 read_lock_bh(&pch->upl); 2125 if (pch->ppp) { 2126 (*this_cpu_ptr(pch->ppp->xmit_recursion))++; 2127 __ppp_channel_push(pch); 2128 (*this_cpu_ptr(pch->ppp->xmit_recursion))--; 2129 } else { 2130 __ppp_channel_push(pch); 2131 } 2132 read_unlock_bh(&pch->upl); 2133 } 2134 2135 /* 2136 * Receive-side routines. 2137 */ 2138 2139 struct ppp_mp_skb_parm { 2140 u32 sequence; 2141 u8 BEbits; 2142 }; 2143 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb)) 2144 2145 static inline void 2146 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2147 { 2148 ppp_recv_lock(ppp); 2149 if (!ppp->closing) 2150 ppp_receive_frame(ppp, skb, pch); 2151 else 2152 kfree_skb(skb); 2153 ppp_recv_unlock(ppp); 2154 } 2155 2156 /** 2157 * __ppp_decompress_proto - Decompress protocol field, slim version. 2158 * @skb: Socket buffer where protocol field should be decompressed. It must have 2159 * at least 1 byte of head room and 1 byte of linear data. First byte of 2160 * data must be a protocol field byte. 2161 * 2162 * Decompress protocol field in PPP header if it's compressed, e.g. when 2163 * Protocol-Field-Compression (PFC) was negotiated. No checks w.r.t. skb data 2164 * length are done in this function. 2165 */ 2166 static void __ppp_decompress_proto(struct sk_buff *skb) 2167 { 2168 if (skb->data[0] & 0x01) 2169 *(u8 *)skb_push(skb, 1) = 0x00; 2170 } 2171 2172 /** 2173 * ppp_decompress_proto - Check skb data room and decompress protocol field. 2174 * @skb: Socket buffer where protocol field should be decompressed. First byte 2175 * of data must be a protocol field byte. 2176 * 2177 * Decompress protocol field in PPP header if it's compressed, e.g. when 2178 * Protocol-Field-Compression (PFC) was negotiated. This function also makes 2179 * sure that skb data room is sufficient for Protocol field, before and after 2180 * decompression. 2181 * 2182 * Return: true - decompressed successfully, false - not enough room in skb. 2183 */ 2184 static bool ppp_decompress_proto(struct sk_buff *skb) 2185 { 2186 /* At least one byte should be present (if protocol is compressed) */ 2187 if (!pskb_may_pull(skb, 1)) 2188 return false; 2189 2190 __ppp_decompress_proto(skb); 2191 2192 /* Protocol field should occupy 2 bytes when not compressed */ 2193 return pskb_may_pull(skb, 2); 2194 } 2195 2196 /* Attempt to handle a frame via. a bridged channel, if one exists. 2197 * If the channel is bridged, the frame is consumed by the bridge. 2198 * If not, the caller must handle the frame by normal recv mechanisms. 2199 * Returns true if the frame is consumed, false otherwise. 2200 */ 2201 static bool ppp_channel_bridge_input(struct channel *pch, struct sk_buff *skb) 2202 { 2203 struct channel *pchb; 2204 2205 rcu_read_lock(); 2206 pchb = rcu_dereference(pch->bridge); 2207 if (!pchb) 2208 goto out_rcu; 2209 2210 spin_lock(&pchb->downl); 2211 if (!pchb->chan) { 2212 /* channel got unregistered */ 2213 kfree_skb(skb); 2214 goto outl; 2215 } 2216 2217 skb_scrub_packet(skb, !net_eq(pch->chan_net, pchb->chan_net)); 2218 if (!pchb->chan->ops->start_xmit(pchb->chan, skb)) 2219 kfree_skb(skb); 2220 2221 outl: 2222 spin_unlock(&pchb->downl); 2223 out_rcu: 2224 rcu_read_unlock(); 2225 2226 /* If pchb is set then we've consumed the packet */ 2227 return !!pchb; 2228 } 2229 2230 void 2231 ppp_input(struct ppp_channel *chan, struct sk_buff *skb) 2232 { 2233 struct channel *pch = chan->ppp; 2234 int proto; 2235 2236 if (!pch) { 2237 kfree_skb(skb); 2238 return; 2239 } 2240 2241 /* If the channel is bridged, transmit via. bridge */ 2242 if (ppp_channel_bridge_input(pch, skb)) 2243 return; 2244 2245 read_lock_bh(&pch->upl); 2246 if (!ppp_decompress_proto(skb)) { 2247 kfree_skb(skb); 2248 if (pch->ppp) { 2249 ++pch->ppp->dev->stats.rx_length_errors; 2250 ppp_receive_error(pch->ppp); 2251 } 2252 goto done; 2253 } 2254 2255 proto = PPP_PROTO(skb); 2256 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) { 2257 /* put it on the channel queue */ 2258 skb_queue_tail(&pch->file.rq, skb); 2259 /* drop old frames if queue too long */ 2260 while (pch->file.rq.qlen > PPP_MAX_RQLEN && 2261 (skb = skb_dequeue(&pch->file.rq))) 2262 kfree_skb(skb); 2263 wake_up_interruptible(&pch->file.rwait); 2264 } else { 2265 ppp_do_recv(pch->ppp, skb, pch); 2266 } 2267 2268 done: 2269 read_unlock_bh(&pch->upl); 2270 } 2271 2272 /* Put a 0-length skb in the receive queue as an error indication */ 2273 void 2274 ppp_input_error(struct ppp_channel *chan, int code) 2275 { 2276 struct channel *pch = chan->ppp; 2277 struct sk_buff *skb; 2278 2279 if (!pch) 2280 return; 2281 2282 read_lock_bh(&pch->upl); 2283 if (pch->ppp) { 2284 skb = alloc_skb(0, GFP_ATOMIC); 2285 if (skb) { 2286 skb->len = 0; /* probably unnecessary */ 2287 skb->cb[0] = code; 2288 ppp_do_recv(pch->ppp, skb, pch); 2289 } 2290 } 2291 read_unlock_bh(&pch->upl); 2292 } 2293 2294 /* 2295 * We come in here to process a received frame. 2296 * The receive side of the ppp unit is locked. 2297 */ 2298 static void 2299 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2300 { 2301 /* note: a 0-length skb is used as an error indication */ 2302 if (skb->len > 0) { 2303 skb_checksum_complete_unset(skb); 2304 #ifdef CONFIG_PPP_MULTILINK 2305 /* XXX do channel-level decompression here */ 2306 if (PPP_PROTO(skb) == PPP_MP) 2307 ppp_receive_mp_frame(ppp, skb, pch); 2308 else 2309 #endif /* CONFIG_PPP_MULTILINK */ 2310 ppp_receive_nonmp_frame(ppp, skb); 2311 } else { 2312 kfree_skb(skb); 2313 ppp_receive_error(ppp); 2314 } 2315 } 2316 2317 static void 2318 ppp_receive_error(struct ppp *ppp) 2319 { 2320 ++ppp->dev->stats.rx_errors; 2321 if (ppp->vj) 2322 slhc_toss(ppp->vj); 2323 } 2324 2325 static void 2326 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) 2327 { 2328 struct sk_buff *ns; 2329 int proto, len, npi; 2330 2331 /* 2332 * Decompress the frame, if compressed. 2333 * Note that some decompressors need to see uncompressed frames 2334 * that come in as well as compressed frames. 2335 */ 2336 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) && 2337 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0) 2338 skb = ppp_decompress_frame(ppp, skb); 2339 2340 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR) 2341 goto err; 2342 2343 /* At this point the "Protocol" field MUST be decompressed, either in 2344 * ppp_input(), ppp_decompress_frame() or in ppp_receive_mp_frame(). 2345 */ 2346 proto = PPP_PROTO(skb); 2347 switch (proto) { 2348 case PPP_VJC_COMP: 2349 /* decompress VJ compressed packets */ 2350 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 2351 goto err; 2352 2353 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) { 2354 /* copy to a new sk_buff with more tailroom */ 2355 ns = dev_alloc_skb(skb->len + 128); 2356 if (!ns) { 2357 netdev_err(ppp->dev, "PPP: no memory " 2358 "(VJ decomp)\n"); 2359 goto err; 2360 } 2361 skb_reserve(ns, 2); 2362 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len); 2363 consume_skb(skb); 2364 skb = ns; 2365 } 2366 else 2367 skb->ip_summed = CHECKSUM_NONE; 2368 2369 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2); 2370 if (len <= 0) { 2371 netdev_printk(KERN_DEBUG, ppp->dev, 2372 "PPP: VJ decompression error\n"); 2373 goto err; 2374 } 2375 len += 2; 2376 if (len > skb->len) 2377 skb_put(skb, len - skb->len); 2378 else if (len < skb->len) 2379 skb_trim(skb, len); 2380 proto = PPP_IP; 2381 break; 2382 2383 case PPP_VJC_UNCOMP: 2384 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 2385 goto err; 2386 2387 /* Until we fix the decompressor need to make sure 2388 * data portion is linear. 2389 */ 2390 if (!pskb_may_pull(skb, skb->len)) 2391 goto err; 2392 2393 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) { 2394 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n"); 2395 goto err; 2396 } 2397 proto = PPP_IP; 2398 break; 2399 2400 case PPP_CCP: 2401 ppp_ccp_peek(ppp, skb, 1); 2402 break; 2403 } 2404 2405 ++ppp->stats64.rx_packets; 2406 ppp->stats64.rx_bytes += skb->len - 2; 2407 2408 npi = proto_to_npindex(proto); 2409 if (npi < 0) { 2410 /* control or unknown frame - pass it to pppd */ 2411 skb_queue_tail(&ppp->file.rq, skb); 2412 /* limit queue length by dropping old frames */ 2413 while (ppp->file.rq.qlen > PPP_MAX_RQLEN && 2414 (skb = skb_dequeue(&ppp->file.rq))) 2415 kfree_skb(skb); 2416 /* wake up any process polling or blocking on read */ 2417 wake_up_interruptible(&ppp->file.rwait); 2418 2419 } else { 2420 /* network protocol frame - give it to the kernel */ 2421 2422 #ifdef CONFIG_PPP_FILTER 2423 /* check if the packet passes the pass and active filters */ 2424 /* the filter instructions are constructed assuming 2425 a four-byte PPP header on each packet */ 2426 if (ppp->pass_filter || ppp->active_filter) { 2427 if (skb_unclone(skb, GFP_ATOMIC)) 2428 goto err; 2429 2430 *(u8 *)skb_push(skb, 2) = 0; 2431 if (ppp->pass_filter && 2432 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 2433 if (ppp->debug & 1) 2434 netdev_printk(KERN_DEBUG, ppp->dev, 2435 "PPP: inbound frame " 2436 "not passed\n"); 2437 kfree_skb(skb); 2438 return; 2439 } 2440 if (!(ppp->active_filter && 2441 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 2442 ppp->last_recv = jiffies; 2443 __skb_pull(skb, 2); 2444 } else 2445 #endif /* CONFIG_PPP_FILTER */ 2446 ppp->last_recv = jiffies; 2447 2448 if ((ppp->dev->flags & IFF_UP) == 0 || 2449 ppp->npmode[npi] != NPMODE_PASS) { 2450 kfree_skb(skb); 2451 } else { 2452 /* chop off protocol */ 2453 skb_pull_rcsum(skb, 2); 2454 skb->dev = ppp->dev; 2455 skb->protocol = htons(npindex_to_ethertype[npi]); 2456 skb_reset_mac_header(skb); 2457 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, 2458 dev_net(ppp->dev))); 2459 netif_rx(skb); 2460 } 2461 } 2462 return; 2463 2464 err: 2465 kfree_skb(skb); 2466 ppp_receive_error(ppp); 2467 } 2468 2469 static struct sk_buff * 2470 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb) 2471 { 2472 int proto = PPP_PROTO(skb); 2473 struct sk_buff *ns; 2474 int len; 2475 2476 /* Until we fix all the decompressor's need to make sure 2477 * data portion is linear. 2478 */ 2479 if (!pskb_may_pull(skb, skb->len)) 2480 goto err; 2481 2482 if (proto == PPP_COMP) { 2483 int obuff_size; 2484 2485 switch(ppp->rcomp->compress_proto) { 2486 case CI_MPPE: 2487 obuff_size = ppp->mru + PPP_HDRLEN + 1; 2488 break; 2489 default: 2490 obuff_size = ppp->mru + PPP_HDRLEN; 2491 break; 2492 } 2493 2494 ns = dev_alloc_skb(obuff_size); 2495 if (!ns) { 2496 netdev_err(ppp->dev, "ppp_decompress_frame: " 2497 "no memory\n"); 2498 goto err; 2499 } 2500 /* the decompressor still expects the A/C bytes in the hdr */ 2501 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2, 2502 skb->len + 2, ns->data, obuff_size); 2503 if (len < 0) { 2504 /* Pass the compressed frame to pppd as an 2505 error indication. */ 2506 if (len == DECOMP_FATALERROR) 2507 ppp->rstate |= SC_DC_FERROR; 2508 kfree_skb(ns); 2509 goto err; 2510 } 2511 2512 consume_skb(skb); 2513 skb = ns; 2514 skb_put(skb, len); 2515 skb_pull(skb, 2); /* pull off the A/C bytes */ 2516 2517 /* Don't call __ppp_decompress_proto() here, but instead rely on 2518 * corresponding algo (mppe/bsd/deflate) to decompress it. 2519 */ 2520 } else { 2521 /* Uncompressed frame - pass to decompressor so it 2522 can update its dictionary if necessary. */ 2523 if (ppp->rcomp->incomp) 2524 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2, 2525 skb->len + 2); 2526 } 2527 2528 return skb; 2529 2530 err: 2531 ppp->rstate |= SC_DC_ERROR; 2532 ppp_receive_error(ppp); 2533 return skb; 2534 } 2535 2536 #ifdef CONFIG_PPP_MULTILINK 2537 /* 2538 * Receive a multilink frame. 2539 * We put it on the reconstruction queue and then pull off 2540 * as many completed frames as we can. 2541 */ 2542 static void 2543 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2544 { 2545 u32 mask, seq; 2546 struct channel *ch; 2547 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 2548 2549 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0) 2550 goto err; /* no good, throw it away */ 2551 2552 /* Decode sequence number and begin/end bits */ 2553 if (ppp->flags & SC_MP_SHORTSEQ) { 2554 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3]; 2555 mask = 0xfff; 2556 } else { 2557 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5]; 2558 mask = 0xffffff; 2559 } 2560 PPP_MP_CB(skb)->BEbits = skb->data[2]; 2561 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */ 2562 2563 /* 2564 * Do protocol ID decompression on the first fragment of each packet. 2565 * We have to do that here, because ppp_receive_nonmp_frame() expects 2566 * decompressed protocol field. 2567 */ 2568 if (PPP_MP_CB(skb)->BEbits & B) 2569 __ppp_decompress_proto(skb); 2570 2571 /* 2572 * Expand sequence number to 32 bits, making it as close 2573 * as possible to ppp->minseq. 2574 */ 2575 seq |= ppp->minseq & ~mask; 2576 if ((int)(ppp->minseq - seq) > (int)(mask >> 1)) 2577 seq += mask + 1; 2578 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1)) 2579 seq -= mask + 1; /* should never happen */ 2580 PPP_MP_CB(skb)->sequence = seq; 2581 pch->lastseq = seq; 2582 2583 /* 2584 * If this packet comes before the next one we were expecting, 2585 * drop it. 2586 */ 2587 if (seq_before(seq, ppp->nextseq)) { 2588 kfree_skb(skb); 2589 ++ppp->dev->stats.rx_dropped; 2590 ppp_receive_error(ppp); 2591 return; 2592 } 2593 2594 /* 2595 * Reevaluate minseq, the minimum over all channels of the 2596 * last sequence number received on each channel. Because of 2597 * the increasing sequence number rule, we know that any fragment 2598 * before `minseq' which hasn't arrived is never going to arrive. 2599 * The list of channels can't change because we have the receive 2600 * side of the ppp unit locked. 2601 */ 2602 list_for_each_entry(ch, &ppp->channels, clist) { 2603 if (seq_before(ch->lastseq, seq)) 2604 seq = ch->lastseq; 2605 } 2606 if (seq_before(ppp->minseq, seq)) 2607 ppp->minseq = seq; 2608 2609 /* Put the fragment on the reconstruction queue */ 2610 ppp_mp_insert(ppp, skb); 2611 2612 /* If the queue is getting long, don't wait any longer for packets 2613 before the start of the queue. */ 2614 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) { 2615 struct sk_buff *mskb = skb_peek(&ppp->mrq); 2616 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence)) 2617 ppp->minseq = PPP_MP_CB(mskb)->sequence; 2618 } 2619 2620 /* Pull completed packets off the queue and receive them. */ 2621 while ((skb = ppp_mp_reconstruct(ppp))) { 2622 if (pskb_may_pull(skb, 2)) 2623 ppp_receive_nonmp_frame(ppp, skb); 2624 else { 2625 ++ppp->dev->stats.rx_length_errors; 2626 kfree_skb(skb); 2627 ppp_receive_error(ppp); 2628 } 2629 } 2630 2631 return; 2632 2633 err: 2634 kfree_skb(skb); 2635 ppp_receive_error(ppp); 2636 } 2637 2638 /* 2639 * Insert a fragment on the MP reconstruction queue. 2640 * The queue is ordered by increasing sequence number. 2641 */ 2642 static void 2643 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb) 2644 { 2645 struct sk_buff *p; 2646 struct sk_buff_head *list = &ppp->mrq; 2647 u32 seq = PPP_MP_CB(skb)->sequence; 2648 2649 /* N.B. we don't need to lock the list lock because we have the 2650 ppp unit receive-side lock. */ 2651 skb_queue_walk(list, p) { 2652 if (seq_before(seq, PPP_MP_CB(p)->sequence)) 2653 break; 2654 } 2655 __skb_queue_before(list, p, skb); 2656 } 2657 2658 /* 2659 * Reconstruct a packet from the MP fragment queue. 2660 * We go through increasing sequence numbers until we find a 2661 * complete packet, or we get to the sequence number for a fragment 2662 * which hasn't arrived but might still do so. 2663 */ 2664 static struct sk_buff * 2665 ppp_mp_reconstruct(struct ppp *ppp) 2666 { 2667 u32 seq = ppp->nextseq; 2668 u32 minseq = ppp->minseq; 2669 struct sk_buff_head *list = &ppp->mrq; 2670 struct sk_buff *p, *tmp; 2671 struct sk_buff *head, *tail; 2672 struct sk_buff *skb = NULL; 2673 int lost = 0, len = 0; 2674 2675 if (ppp->mrru == 0) /* do nothing until mrru is set */ 2676 return NULL; 2677 head = __skb_peek(list); 2678 tail = NULL; 2679 skb_queue_walk_safe(list, p, tmp) { 2680 again: 2681 if (seq_before(PPP_MP_CB(p)->sequence, seq)) { 2682 /* this can't happen, anyway ignore the skb */ 2683 netdev_err(ppp->dev, "ppp_mp_reconstruct bad " 2684 "seq %u < %u\n", 2685 PPP_MP_CB(p)->sequence, seq); 2686 __skb_unlink(p, list); 2687 kfree_skb(p); 2688 continue; 2689 } 2690 if (PPP_MP_CB(p)->sequence != seq) { 2691 u32 oldseq; 2692 /* Fragment `seq' is missing. If it is after 2693 minseq, it might arrive later, so stop here. */ 2694 if (seq_after(seq, minseq)) 2695 break; 2696 /* Fragment `seq' is lost, keep going. */ 2697 lost = 1; 2698 oldseq = seq; 2699 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)? 2700 minseq + 1: PPP_MP_CB(p)->sequence; 2701 2702 if (ppp->debug & 1) 2703 netdev_printk(KERN_DEBUG, ppp->dev, 2704 "lost frag %u..%u\n", 2705 oldseq, seq-1); 2706 2707 goto again; 2708 } 2709 2710 /* 2711 * At this point we know that all the fragments from 2712 * ppp->nextseq to seq are either present or lost. 2713 * Also, there are no complete packets in the queue 2714 * that have no missing fragments and end before this 2715 * fragment. 2716 */ 2717 2718 /* B bit set indicates this fragment starts a packet */ 2719 if (PPP_MP_CB(p)->BEbits & B) { 2720 head = p; 2721 lost = 0; 2722 len = 0; 2723 } 2724 2725 len += p->len; 2726 2727 /* Got a complete packet yet? */ 2728 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) && 2729 (PPP_MP_CB(head)->BEbits & B)) { 2730 if (len > ppp->mrru + 2) { 2731 ++ppp->dev->stats.rx_length_errors; 2732 netdev_printk(KERN_DEBUG, ppp->dev, 2733 "PPP: reconstructed packet" 2734 " is too long (%d)\n", len); 2735 } else { 2736 tail = p; 2737 break; 2738 } 2739 ppp->nextseq = seq + 1; 2740 } 2741 2742 /* 2743 * If this is the ending fragment of a packet, 2744 * and we haven't found a complete valid packet yet, 2745 * we can discard up to and including this fragment. 2746 */ 2747 if (PPP_MP_CB(p)->BEbits & E) { 2748 struct sk_buff *tmp2; 2749 2750 skb_queue_reverse_walk_from_safe(list, p, tmp2) { 2751 if (ppp->debug & 1) 2752 netdev_printk(KERN_DEBUG, ppp->dev, 2753 "discarding frag %u\n", 2754 PPP_MP_CB(p)->sequence); 2755 __skb_unlink(p, list); 2756 kfree_skb(p); 2757 } 2758 head = skb_peek(list); 2759 if (!head) 2760 break; 2761 } 2762 ++seq; 2763 } 2764 2765 /* If we have a complete packet, copy it all into one skb. */ 2766 if (tail != NULL) { 2767 /* If we have discarded any fragments, 2768 signal a receive error. */ 2769 if (PPP_MP_CB(head)->sequence != ppp->nextseq) { 2770 skb_queue_walk_safe(list, p, tmp) { 2771 if (p == head) 2772 break; 2773 if (ppp->debug & 1) 2774 netdev_printk(KERN_DEBUG, ppp->dev, 2775 "discarding frag %u\n", 2776 PPP_MP_CB(p)->sequence); 2777 __skb_unlink(p, list); 2778 kfree_skb(p); 2779 } 2780 2781 if (ppp->debug & 1) 2782 netdev_printk(KERN_DEBUG, ppp->dev, 2783 " missed pkts %u..%u\n", 2784 ppp->nextseq, 2785 PPP_MP_CB(head)->sequence-1); 2786 ++ppp->dev->stats.rx_dropped; 2787 ppp_receive_error(ppp); 2788 } 2789 2790 skb = head; 2791 if (head != tail) { 2792 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list; 2793 p = skb_queue_next(list, head); 2794 __skb_unlink(skb, list); 2795 skb_queue_walk_from_safe(list, p, tmp) { 2796 __skb_unlink(p, list); 2797 *fragpp = p; 2798 p->next = NULL; 2799 fragpp = &p->next; 2800 2801 skb->len += p->len; 2802 skb->data_len += p->len; 2803 skb->truesize += p->truesize; 2804 2805 if (p == tail) 2806 break; 2807 } 2808 } else { 2809 __skb_unlink(skb, list); 2810 } 2811 2812 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1; 2813 } 2814 2815 return skb; 2816 } 2817 #endif /* CONFIG_PPP_MULTILINK */ 2818 2819 /* 2820 * Channel interface. 2821 */ 2822 2823 /* Create a new, unattached ppp channel. */ 2824 int ppp_register_channel(struct ppp_channel *chan) 2825 { 2826 return ppp_register_net_channel(current->nsproxy->net_ns, chan); 2827 } 2828 2829 /* Create a new, unattached ppp channel for specified net. */ 2830 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan) 2831 { 2832 struct channel *pch; 2833 struct ppp_net *pn; 2834 2835 pch = kzalloc(sizeof(struct channel), GFP_KERNEL); 2836 if (!pch) 2837 return -ENOMEM; 2838 2839 pn = ppp_pernet(net); 2840 2841 pch->ppp = NULL; 2842 pch->chan = chan; 2843 pch->chan_net = get_net(net); 2844 chan->ppp = pch; 2845 init_ppp_file(&pch->file, CHANNEL); 2846 pch->file.hdrlen = chan->hdrlen; 2847 #ifdef CONFIG_PPP_MULTILINK 2848 pch->lastseq = -1; 2849 #endif /* CONFIG_PPP_MULTILINK */ 2850 init_rwsem(&pch->chan_sem); 2851 spin_lock_init(&pch->downl); 2852 rwlock_init(&pch->upl); 2853 2854 spin_lock_bh(&pn->all_channels_lock); 2855 pch->file.index = ++pn->last_channel_index; 2856 list_add(&pch->list, &pn->new_channels); 2857 atomic_inc(&channel_count); 2858 spin_unlock_bh(&pn->all_channels_lock); 2859 2860 return 0; 2861 } 2862 2863 /* 2864 * Return the index of a channel. 2865 */ 2866 int ppp_channel_index(struct ppp_channel *chan) 2867 { 2868 struct channel *pch = chan->ppp; 2869 2870 if (pch) 2871 return pch->file.index; 2872 return -1; 2873 } 2874 2875 /* 2876 * Return the PPP unit number to which a channel is connected. 2877 */ 2878 int ppp_unit_number(struct ppp_channel *chan) 2879 { 2880 struct channel *pch = chan->ppp; 2881 int unit = -1; 2882 2883 if (pch) { 2884 read_lock_bh(&pch->upl); 2885 if (pch->ppp) 2886 unit = pch->ppp->file.index; 2887 read_unlock_bh(&pch->upl); 2888 } 2889 return unit; 2890 } 2891 2892 /* 2893 * Return the PPP device interface name of a channel. 2894 */ 2895 char *ppp_dev_name(struct ppp_channel *chan) 2896 { 2897 struct channel *pch = chan->ppp; 2898 char *name = NULL; 2899 2900 if (pch) { 2901 read_lock_bh(&pch->upl); 2902 if (pch->ppp && pch->ppp->dev) 2903 name = pch->ppp->dev->name; 2904 read_unlock_bh(&pch->upl); 2905 } 2906 return name; 2907 } 2908 2909 2910 /* 2911 * Disconnect a channel from the generic layer. 2912 * This must be called in process context. 2913 */ 2914 void 2915 ppp_unregister_channel(struct ppp_channel *chan) 2916 { 2917 struct channel *pch = chan->ppp; 2918 struct ppp_net *pn; 2919 2920 if (!pch) 2921 return; /* should never happen */ 2922 2923 chan->ppp = NULL; 2924 2925 /* 2926 * This ensures that we have returned from any calls into the 2927 * the channel's start_xmit or ioctl routine before we proceed. 2928 */ 2929 down_write(&pch->chan_sem); 2930 spin_lock_bh(&pch->downl); 2931 pch->chan = NULL; 2932 spin_unlock_bh(&pch->downl); 2933 up_write(&pch->chan_sem); 2934 ppp_disconnect_channel(pch); 2935 2936 pn = ppp_pernet(pch->chan_net); 2937 spin_lock_bh(&pn->all_channels_lock); 2938 list_del(&pch->list); 2939 spin_unlock_bh(&pn->all_channels_lock); 2940 2941 ppp_unbridge_channels(pch); 2942 2943 pch->file.dead = 1; 2944 wake_up_interruptible(&pch->file.rwait); 2945 2946 if (refcount_dec_and_test(&pch->file.refcnt)) 2947 ppp_destroy_channel(pch); 2948 } 2949 2950 /* 2951 * Callback from a channel when it can accept more to transmit. 2952 * This should be called at BH/softirq level, not interrupt level. 2953 */ 2954 void 2955 ppp_output_wakeup(struct ppp_channel *chan) 2956 { 2957 struct channel *pch = chan->ppp; 2958 2959 if (!pch) 2960 return; 2961 ppp_channel_push(pch); 2962 } 2963 2964 /* 2965 * Compression control. 2966 */ 2967 2968 /* Process the PPPIOCSCOMPRESS ioctl. */ 2969 static int 2970 ppp_set_compress(struct ppp *ppp, struct ppp_option_data *data) 2971 { 2972 int err = -EFAULT; 2973 struct compressor *cp, *ocomp; 2974 void *state, *ostate; 2975 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH]; 2976 2977 if (data->length > CCP_MAX_OPTION_LENGTH) 2978 goto out; 2979 if (copy_from_user(ccp_option, data->ptr, data->length)) 2980 goto out; 2981 2982 err = -EINVAL; 2983 if (data->length < 2 || ccp_option[1] < 2 || ccp_option[1] > data->length) 2984 goto out; 2985 2986 cp = try_then_request_module( 2987 find_compressor(ccp_option[0]), 2988 "ppp-compress-%d", ccp_option[0]); 2989 if (!cp) 2990 goto out; 2991 2992 err = -ENOBUFS; 2993 if (data->transmit) { 2994 state = cp->comp_alloc(ccp_option, data->length); 2995 if (state) { 2996 ppp_xmit_lock(ppp); 2997 ppp->xstate &= ~SC_COMP_RUN; 2998 ocomp = ppp->xcomp; 2999 ostate = ppp->xc_state; 3000 ppp->xcomp = cp; 3001 ppp->xc_state = state; 3002 ppp_xmit_unlock(ppp); 3003 if (ostate) { 3004 ocomp->comp_free(ostate); 3005 module_put(ocomp->owner); 3006 } 3007 err = 0; 3008 } else 3009 module_put(cp->owner); 3010 3011 } else { 3012 state = cp->decomp_alloc(ccp_option, data->length); 3013 if (state) { 3014 ppp_recv_lock(ppp); 3015 ppp->rstate &= ~SC_DECOMP_RUN; 3016 ocomp = ppp->rcomp; 3017 ostate = ppp->rc_state; 3018 ppp->rcomp = cp; 3019 ppp->rc_state = state; 3020 ppp_recv_unlock(ppp); 3021 if (ostate) { 3022 ocomp->decomp_free(ostate); 3023 module_put(ocomp->owner); 3024 } 3025 err = 0; 3026 } else 3027 module_put(cp->owner); 3028 } 3029 3030 out: 3031 return err; 3032 } 3033 3034 /* 3035 * Look at a CCP packet and update our state accordingly. 3036 * We assume the caller has the xmit or recv path locked. 3037 */ 3038 static void 3039 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound) 3040 { 3041 unsigned char *dp; 3042 int len; 3043 3044 if (!pskb_may_pull(skb, CCP_HDRLEN + 2)) 3045 return; /* no header */ 3046 dp = skb->data + 2; 3047 3048 switch (CCP_CODE(dp)) { 3049 case CCP_CONFREQ: 3050 3051 /* A ConfReq starts negotiation of compression 3052 * in one direction of transmission, 3053 * and hence brings it down...but which way? 3054 * 3055 * Remember: 3056 * A ConfReq indicates what the sender would like to receive 3057 */ 3058 if(inbound) 3059 /* He is proposing what I should send */ 3060 ppp->xstate &= ~SC_COMP_RUN; 3061 else 3062 /* I am proposing to what he should send */ 3063 ppp->rstate &= ~SC_DECOMP_RUN; 3064 3065 break; 3066 3067 case CCP_TERMREQ: 3068 case CCP_TERMACK: 3069 /* 3070 * CCP is going down, both directions of transmission 3071 */ 3072 ppp->rstate &= ~SC_DECOMP_RUN; 3073 ppp->xstate &= ~SC_COMP_RUN; 3074 break; 3075 3076 case CCP_CONFACK: 3077 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN) 3078 break; 3079 len = CCP_LENGTH(dp); 3080 if (!pskb_may_pull(skb, len + 2)) 3081 return; /* too short */ 3082 dp += CCP_HDRLEN; 3083 len -= CCP_HDRLEN; 3084 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp)) 3085 break; 3086 if (inbound) { 3087 /* we will start receiving compressed packets */ 3088 if (!ppp->rc_state) 3089 break; 3090 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len, 3091 ppp->file.index, 0, ppp->mru, ppp->debug)) { 3092 ppp->rstate |= SC_DECOMP_RUN; 3093 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR); 3094 } 3095 } else { 3096 /* we will soon start sending compressed packets */ 3097 if (!ppp->xc_state) 3098 break; 3099 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len, 3100 ppp->file.index, 0, ppp->debug)) 3101 ppp->xstate |= SC_COMP_RUN; 3102 } 3103 break; 3104 3105 case CCP_RESETACK: 3106 /* reset the [de]compressor */ 3107 if ((ppp->flags & SC_CCP_UP) == 0) 3108 break; 3109 if (inbound) { 3110 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) { 3111 ppp->rcomp->decomp_reset(ppp->rc_state); 3112 ppp->rstate &= ~SC_DC_ERROR; 3113 } 3114 } else { 3115 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN)) 3116 ppp->xcomp->comp_reset(ppp->xc_state); 3117 } 3118 break; 3119 } 3120 } 3121 3122 /* Free up compression resources. */ 3123 static void 3124 ppp_ccp_closed(struct ppp *ppp) 3125 { 3126 void *xstate, *rstate; 3127 struct compressor *xcomp, *rcomp; 3128 3129 ppp_lock(ppp); 3130 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP); 3131 ppp->xstate = 0; 3132 xcomp = ppp->xcomp; 3133 xstate = ppp->xc_state; 3134 ppp->xc_state = NULL; 3135 ppp->rstate = 0; 3136 rcomp = ppp->rcomp; 3137 rstate = ppp->rc_state; 3138 ppp->rc_state = NULL; 3139 ppp_unlock(ppp); 3140 3141 if (xstate) { 3142 xcomp->comp_free(xstate); 3143 module_put(xcomp->owner); 3144 } 3145 if (rstate) { 3146 rcomp->decomp_free(rstate); 3147 module_put(rcomp->owner); 3148 } 3149 } 3150 3151 /* List of compressors. */ 3152 static LIST_HEAD(compressor_list); 3153 static DEFINE_SPINLOCK(compressor_list_lock); 3154 3155 struct compressor_entry { 3156 struct list_head list; 3157 struct compressor *comp; 3158 }; 3159 3160 static struct compressor_entry * 3161 find_comp_entry(int proto) 3162 { 3163 struct compressor_entry *ce; 3164 3165 list_for_each_entry(ce, &compressor_list, list) { 3166 if (ce->comp->compress_proto == proto) 3167 return ce; 3168 } 3169 return NULL; 3170 } 3171 3172 /* Register a compressor */ 3173 int 3174 ppp_register_compressor(struct compressor *cp) 3175 { 3176 struct compressor_entry *ce; 3177 int ret; 3178 spin_lock(&compressor_list_lock); 3179 ret = -EEXIST; 3180 if (find_comp_entry(cp->compress_proto)) 3181 goto out; 3182 ret = -ENOMEM; 3183 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC); 3184 if (!ce) 3185 goto out; 3186 ret = 0; 3187 ce->comp = cp; 3188 list_add(&ce->list, &compressor_list); 3189 out: 3190 spin_unlock(&compressor_list_lock); 3191 return ret; 3192 } 3193 3194 /* Unregister a compressor */ 3195 void 3196 ppp_unregister_compressor(struct compressor *cp) 3197 { 3198 struct compressor_entry *ce; 3199 3200 spin_lock(&compressor_list_lock); 3201 ce = find_comp_entry(cp->compress_proto); 3202 if (ce && ce->comp == cp) { 3203 list_del(&ce->list); 3204 kfree(ce); 3205 } 3206 spin_unlock(&compressor_list_lock); 3207 } 3208 3209 /* Find a compressor. */ 3210 static struct compressor * 3211 find_compressor(int type) 3212 { 3213 struct compressor_entry *ce; 3214 struct compressor *cp = NULL; 3215 3216 spin_lock(&compressor_list_lock); 3217 ce = find_comp_entry(type); 3218 if (ce) { 3219 cp = ce->comp; 3220 if (!try_module_get(cp->owner)) 3221 cp = NULL; 3222 } 3223 spin_unlock(&compressor_list_lock); 3224 return cp; 3225 } 3226 3227 /* 3228 * Miscelleneous stuff. 3229 */ 3230 3231 static void 3232 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st) 3233 { 3234 struct slcompress *vj = ppp->vj; 3235 3236 memset(st, 0, sizeof(*st)); 3237 st->p.ppp_ipackets = ppp->stats64.rx_packets; 3238 st->p.ppp_ierrors = ppp->dev->stats.rx_errors; 3239 st->p.ppp_ibytes = ppp->stats64.rx_bytes; 3240 st->p.ppp_opackets = ppp->stats64.tx_packets; 3241 st->p.ppp_oerrors = ppp->dev->stats.tx_errors; 3242 st->p.ppp_obytes = ppp->stats64.tx_bytes; 3243 if (!vj) 3244 return; 3245 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed; 3246 st->vj.vjs_compressed = vj->sls_o_compressed; 3247 st->vj.vjs_searches = vj->sls_o_searches; 3248 st->vj.vjs_misses = vj->sls_o_misses; 3249 st->vj.vjs_errorin = vj->sls_i_error; 3250 st->vj.vjs_tossed = vj->sls_i_tossed; 3251 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed; 3252 st->vj.vjs_compressedin = vj->sls_i_compressed; 3253 } 3254 3255 /* 3256 * Stuff for handling the lists of ppp units and channels 3257 * and for initialization. 3258 */ 3259 3260 /* 3261 * Create a new ppp interface unit. Fails if it can't allocate memory 3262 * or if there is already a unit with the requested number. 3263 * unit == -1 means allocate a new number. 3264 */ 3265 static int ppp_create_interface(struct net *net, struct file *file, int *unit) 3266 { 3267 struct ppp_config conf = { 3268 .file = file, 3269 .unit = *unit, 3270 .ifname_is_set = false, 3271 }; 3272 struct net_device *dev; 3273 struct ppp *ppp; 3274 int err; 3275 3276 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup); 3277 if (!dev) { 3278 err = -ENOMEM; 3279 goto err; 3280 } 3281 dev_net_set(dev, net); 3282 dev->rtnl_link_ops = &ppp_link_ops; 3283 3284 rtnl_lock(); 3285 3286 err = ppp_dev_configure(net, dev, &conf); 3287 if (err < 0) 3288 goto err_dev; 3289 ppp = netdev_priv(dev); 3290 *unit = ppp->file.index; 3291 3292 rtnl_unlock(); 3293 3294 return 0; 3295 3296 err_dev: 3297 rtnl_unlock(); 3298 free_netdev(dev); 3299 err: 3300 return err; 3301 } 3302 3303 /* 3304 * Initialize a ppp_file structure. 3305 */ 3306 static void 3307 init_ppp_file(struct ppp_file *pf, int kind) 3308 { 3309 pf->kind = kind; 3310 skb_queue_head_init(&pf->xq); 3311 skb_queue_head_init(&pf->rq); 3312 refcount_set(&pf->refcnt, 1); 3313 init_waitqueue_head(&pf->rwait); 3314 } 3315 3316 /* 3317 * Free the memory used by a ppp unit. This is only called once 3318 * there are no channels connected to the unit and no file structs 3319 * that reference the unit. 3320 */ 3321 static void ppp_destroy_interface(struct ppp *ppp) 3322 { 3323 atomic_dec(&ppp_unit_count); 3324 3325 if (!ppp->file.dead || ppp->n_channels) { 3326 /* "can't happen" */ 3327 netdev_err(ppp->dev, "ppp: destroying ppp struct %p " 3328 "but dead=%d n_channels=%d !\n", 3329 ppp, ppp->file.dead, ppp->n_channels); 3330 return; 3331 } 3332 3333 ppp_ccp_closed(ppp); 3334 if (ppp->vj) { 3335 slhc_free(ppp->vj); 3336 ppp->vj = NULL; 3337 } 3338 skb_queue_purge(&ppp->file.xq); 3339 skb_queue_purge(&ppp->file.rq); 3340 #ifdef CONFIG_PPP_MULTILINK 3341 skb_queue_purge(&ppp->mrq); 3342 #endif /* CONFIG_PPP_MULTILINK */ 3343 #ifdef CONFIG_PPP_FILTER 3344 if (ppp->pass_filter) { 3345 bpf_prog_destroy(ppp->pass_filter); 3346 ppp->pass_filter = NULL; 3347 } 3348 3349 if (ppp->active_filter) { 3350 bpf_prog_destroy(ppp->active_filter); 3351 ppp->active_filter = NULL; 3352 } 3353 #endif /* CONFIG_PPP_FILTER */ 3354 3355 kfree_skb(ppp->xmit_pending); 3356 free_percpu(ppp->xmit_recursion); 3357 3358 free_netdev(ppp->dev); 3359 } 3360 3361 /* 3362 * Locate an existing ppp unit. 3363 * The caller should have locked the all_ppp_mutex. 3364 */ 3365 static struct ppp * 3366 ppp_find_unit(struct ppp_net *pn, int unit) 3367 { 3368 return unit_find(&pn->units_idr, unit); 3369 } 3370 3371 /* 3372 * Locate an existing ppp channel. 3373 * The caller should have locked the all_channels_lock. 3374 * First we look in the new_channels list, then in the 3375 * all_channels list. If found in the new_channels list, 3376 * we move it to the all_channels list. This is for speed 3377 * when we have a lot of channels in use. 3378 */ 3379 static struct channel * 3380 ppp_find_channel(struct ppp_net *pn, int unit) 3381 { 3382 struct channel *pch; 3383 3384 list_for_each_entry(pch, &pn->new_channels, list) { 3385 if (pch->file.index == unit) { 3386 list_move(&pch->list, &pn->all_channels); 3387 return pch; 3388 } 3389 } 3390 3391 list_for_each_entry(pch, &pn->all_channels, list) { 3392 if (pch->file.index == unit) 3393 return pch; 3394 } 3395 3396 return NULL; 3397 } 3398 3399 /* 3400 * Connect a PPP channel to a PPP interface unit. 3401 */ 3402 static int 3403 ppp_connect_channel(struct channel *pch, int unit) 3404 { 3405 struct ppp *ppp; 3406 struct ppp_net *pn; 3407 int ret = -ENXIO; 3408 int hdrlen; 3409 3410 pn = ppp_pernet(pch->chan_net); 3411 3412 mutex_lock(&pn->all_ppp_mutex); 3413 ppp = ppp_find_unit(pn, unit); 3414 if (!ppp) 3415 goto out; 3416 write_lock_bh(&pch->upl); 3417 ret = -EINVAL; 3418 if (pch->ppp || 3419 rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl))) 3420 goto outl; 3421 3422 ppp_lock(ppp); 3423 spin_lock_bh(&pch->downl); 3424 if (!pch->chan) { 3425 /* Don't connect unregistered channels */ 3426 spin_unlock_bh(&pch->downl); 3427 ppp_unlock(ppp); 3428 ret = -ENOTCONN; 3429 goto outl; 3430 } 3431 spin_unlock_bh(&pch->downl); 3432 if (pch->file.hdrlen > ppp->file.hdrlen) 3433 ppp->file.hdrlen = pch->file.hdrlen; 3434 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */ 3435 if (hdrlen > ppp->dev->hard_header_len) 3436 ppp->dev->hard_header_len = hdrlen; 3437 list_add_tail(&pch->clist, &ppp->channels); 3438 ++ppp->n_channels; 3439 pch->ppp = ppp; 3440 refcount_inc(&ppp->file.refcnt); 3441 ppp_unlock(ppp); 3442 ret = 0; 3443 3444 outl: 3445 write_unlock_bh(&pch->upl); 3446 out: 3447 mutex_unlock(&pn->all_ppp_mutex); 3448 return ret; 3449 } 3450 3451 /* 3452 * Disconnect a channel from its ppp unit. 3453 */ 3454 static int 3455 ppp_disconnect_channel(struct channel *pch) 3456 { 3457 struct ppp *ppp; 3458 int err = -EINVAL; 3459 3460 write_lock_bh(&pch->upl); 3461 ppp = pch->ppp; 3462 pch->ppp = NULL; 3463 write_unlock_bh(&pch->upl); 3464 if (ppp) { 3465 /* remove it from the ppp unit's list */ 3466 ppp_lock(ppp); 3467 list_del(&pch->clist); 3468 if (--ppp->n_channels == 0) 3469 wake_up_interruptible(&ppp->file.rwait); 3470 ppp_unlock(ppp); 3471 if (refcount_dec_and_test(&ppp->file.refcnt)) 3472 ppp_destroy_interface(ppp); 3473 err = 0; 3474 } 3475 return err; 3476 } 3477 3478 /* 3479 * Free up the resources used by a ppp channel. 3480 */ 3481 static void ppp_destroy_channel(struct channel *pch) 3482 { 3483 put_net(pch->chan_net); 3484 pch->chan_net = NULL; 3485 3486 atomic_dec(&channel_count); 3487 3488 if (!pch->file.dead) { 3489 /* "can't happen" */ 3490 pr_err("ppp: destroying undead channel %p !\n", pch); 3491 return; 3492 } 3493 skb_queue_purge(&pch->file.xq); 3494 skb_queue_purge(&pch->file.rq); 3495 kfree(pch); 3496 } 3497 3498 static void __exit ppp_cleanup(void) 3499 { 3500 /* should never happen */ 3501 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count)) 3502 pr_err("PPP: removing module but units remain!\n"); 3503 rtnl_link_unregister(&ppp_link_ops); 3504 unregister_chrdev(PPP_MAJOR, "ppp"); 3505 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0)); 3506 class_destroy(ppp_class); 3507 unregister_pernet_device(&ppp_net_ops); 3508 } 3509 3510 /* 3511 * Units handling. Caller must protect concurrent access 3512 * by holding all_ppp_mutex 3513 */ 3514 3515 /* associate pointer with specified number */ 3516 static int unit_set(struct idr *p, void *ptr, int n) 3517 { 3518 int unit; 3519 3520 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL); 3521 if (unit == -ENOSPC) 3522 unit = -EINVAL; 3523 return unit; 3524 } 3525 3526 /* get new free unit number and associate pointer with it */ 3527 static int unit_get(struct idr *p, void *ptr) 3528 { 3529 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL); 3530 } 3531 3532 /* put unit number back to a pool */ 3533 static void unit_put(struct idr *p, int n) 3534 { 3535 idr_remove(p, n); 3536 } 3537 3538 /* get pointer associated with the number */ 3539 static void *unit_find(struct idr *p, int n) 3540 { 3541 return idr_find(p, n); 3542 } 3543 3544 /* Module/initialization stuff */ 3545 3546 module_init(ppp_init); 3547 module_exit(ppp_cleanup); 3548 3549 EXPORT_SYMBOL(ppp_register_net_channel); 3550 EXPORT_SYMBOL(ppp_register_channel); 3551 EXPORT_SYMBOL(ppp_unregister_channel); 3552 EXPORT_SYMBOL(ppp_channel_index); 3553 EXPORT_SYMBOL(ppp_unit_number); 3554 EXPORT_SYMBOL(ppp_dev_name); 3555 EXPORT_SYMBOL(ppp_input); 3556 EXPORT_SYMBOL(ppp_input_error); 3557 EXPORT_SYMBOL(ppp_output_wakeup); 3558 EXPORT_SYMBOL(ppp_register_compressor); 3559 EXPORT_SYMBOL(ppp_unregister_compressor); 3560 MODULE_LICENSE("GPL"); 3561 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0); 3562 MODULE_ALIAS_RTNL_LINK("ppp"); 3563 MODULE_ALIAS("devname:ppp"); 3564