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 refcount_inc(&pchb->file.refcnt); 627 rcu_assign_pointer(pch->bridge, pchb); 628 write_unlock_bh(&pch->upl); 629 630 write_lock_bh(&pchb->upl); 631 if (pchb->ppp || 632 rcu_dereference_protected(pchb->bridge, lockdep_is_held(&pchb->upl))) { 633 write_unlock_bh(&pchb->upl); 634 goto err_unset; 635 } 636 refcount_inc(&pch->file.refcnt); 637 rcu_assign_pointer(pchb->bridge, pch); 638 write_unlock_bh(&pchb->upl); 639 640 return 0; 641 642 err_unset: 643 write_lock_bh(&pch->upl); 644 /* Re-read pch->bridge with upl held in case it was modified concurrently */ 645 pchb = rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl)); 646 RCU_INIT_POINTER(pch->bridge, NULL); 647 write_unlock_bh(&pch->upl); 648 synchronize_rcu(); 649 650 if (pchb) 651 if (refcount_dec_and_test(&pchb->file.refcnt)) 652 ppp_destroy_channel(pchb); 653 654 return -EALREADY; 655 } 656 657 static int ppp_unbridge_channels(struct channel *pch) 658 { 659 struct channel *pchb, *pchbb; 660 661 write_lock_bh(&pch->upl); 662 pchb = rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl)); 663 if (!pchb) { 664 write_unlock_bh(&pch->upl); 665 return -EINVAL; 666 } 667 RCU_INIT_POINTER(pch->bridge, NULL); 668 write_unlock_bh(&pch->upl); 669 670 /* Only modify pchb if phcb->bridge points back to pch. 671 * If not, it implies that there has been a race unbridging (and possibly 672 * even rebridging) pchb. We should leave pchb alone to avoid either a 673 * refcount underflow, or breaking another established bridge instance. 674 */ 675 write_lock_bh(&pchb->upl); 676 pchbb = rcu_dereference_protected(pchb->bridge, lockdep_is_held(&pchb->upl)); 677 if (pchbb == pch) 678 RCU_INIT_POINTER(pchb->bridge, NULL); 679 write_unlock_bh(&pchb->upl); 680 681 synchronize_rcu(); 682 683 if (pchbb == pch) 684 if (refcount_dec_and_test(&pch->file.refcnt)) 685 ppp_destroy_channel(pch); 686 687 if (refcount_dec_and_test(&pchb->file.refcnt)) 688 ppp_destroy_channel(pchb); 689 690 return 0; 691 } 692 693 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 694 { 695 struct ppp_file *pf; 696 struct ppp *ppp; 697 int err = -EFAULT, val, val2, i; 698 struct ppp_idle32 idle32; 699 struct ppp_idle64 idle64; 700 struct npioctl npi; 701 int unit, cflags; 702 struct slcompress *vj; 703 void __user *argp = (void __user *)arg; 704 int __user *p = argp; 705 706 mutex_lock(&ppp_mutex); 707 708 pf = file->private_data; 709 if (!pf) { 710 err = ppp_unattached_ioctl(current->nsproxy->net_ns, 711 pf, file, cmd, arg); 712 goto out; 713 } 714 715 if (cmd == PPPIOCDETACH) { 716 /* 717 * PPPIOCDETACH is no longer supported as it was heavily broken, 718 * and is only known to have been used by pppd older than 719 * ppp-2.4.2 (released November 2003). 720 */ 721 pr_warn_once("%s (%d) used obsolete PPPIOCDETACH ioctl\n", 722 current->comm, current->pid); 723 err = -EINVAL; 724 goto out; 725 } 726 727 if (pf->kind == CHANNEL) { 728 struct channel *pch, *pchb; 729 struct ppp_channel *chan; 730 struct ppp_net *pn; 731 732 pch = PF_TO_CHANNEL(pf); 733 734 switch (cmd) { 735 case PPPIOCCONNECT: 736 if (get_user(unit, p)) 737 break; 738 err = ppp_connect_channel(pch, unit); 739 break; 740 741 case PPPIOCDISCONN: 742 err = ppp_disconnect_channel(pch); 743 break; 744 745 case PPPIOCBRIDGECHAN: 746 if (get_user(unit, p)) 747 break; 748 err = -ENXIO; 749 pn = ppp_pernet(current->nsproxy->net_ns); 750 spin_lock_bh(&pn->all_channels_lock); 751 pchb = ppp_find_channel(pn, unit); 752 /* Hold a reference to prevent pchb being freed while 753 * we establish the bridge. 754 */ 755 if (pchb) 756 refcount_inc(&pchb->file.refcnt); 757 spin_unlock_bh(&pn->all_channels_lock); 758 if (!pchb) 759 break; 760 err = ppp_bridge_channels(pch, pchb); 761 /* Drop earlier refcount now bridge establishment is complete */ 762 if (refcount_dec_and_test(&pchb->file.refcnt)) 763 ppp_destroy_channel(pchb); 764 break; 765 766 case PPPIOCUNBRIDGECHAN: 767 err = ppp_unbridge_channels(pch); 768 break; 769 770 default: 771 down_read(&pch->chan_sem); 772 chan = pch->chan; 773 err = -ENOTTY; 774 if (chan && chan->ops->ioctl) 775 err = chan->ops->ioctl(chan, cmd, arg); 776 up_read(&pch->chan_sem); 777 } 778 goto out; 779 } 780 781 if (pf->kind != INTERFACE) { 782 /* can't happen */ 783 pr_err("PPP: not interface or channel??\n"); 784 err = -EINVAL; 785 goto out; 786 } 787 788 ppp = PF_TO_PPP(pf); 789 switch (cmd) { 790 case PPPIOCSMRU: 791 if (get_user(val, p)) 792 break; 793 ppp->mru = val; 794 err = 0; 795 break; 796 797 case PPPIOCSFLAGS: 798 if (get_user(val, p)) 799 break; 800 ppp_lock(ppp); 801 cflags = ppp->flags & ~val; 802 #ifdef CONFIG_PPP_MULTILINK 803 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK)) 804 ppp->nextseq = 0; 805 #endif 806 ppp->flags = val & SC_FLAG_BITS; 807 ppp_unlock(ppp); 808 if (cflags & SC_CCP_OPEN) 809 ppp_ccp_closed(ppp); 810 err = 0; 811 break; 812 813 case PPPIOCGFLAGS: 814 val = ppp->flags | ppp->xstate | ppp->rstate; 815 if (put_user(val, p)) 816 break; 817 err = 0; 818 break; 819 820 case PPPIOCSCOMPRESS: 821 { 822 struct ppp_option_data data; 823 if (copy_from_user(&data, argp, sizeof(data))) 824 err = -EFAULT; 825 else 826 err = ppp_set_compress(ppp, &data); 827 break; 828 } 829 case PPPIOCGUNIT: 830 if (put_user(ppp->file.index, p)) 831 break; 832 err = 0; 833 break; 834 835 case PPPIOCSDEBUG: 836 if (get_user(val, p)) 837 break; 838 ppp->debug = val; 839 err = 0; 840 break; 841 842 case PPPIOCGDEBUG: 843 if (put_user(ppp->debug, p)) 844 break; 845 err = 0; 846 break; 847 848 case PPPIOCGIDLE32: 849 idle32.xmit_idle = (jiffies - ppp->last_xmit) / HZ; 850 idle32.recv_idle = (jiffies - ppp->last_recv) / HZ; 851 if (copy_to_user(argp, &idle32, sizeof(idle32))) 852 break; 853 err = 0; 854 break; 855 856 case PPPIOCGIDLE64: 857 idle64.xmit_idle = (jiffies - ppp->last_xmit) / HZ; 858 idle64.recv_idle = (jiffies - ppp->last_recv) / HZ; 859 if (copy_to_user(argp, &idle64, sizeof(idle64))) 860 break; 861 err = 0; 862 break; 863 864 case PPPIOCSMAXCID: 865 if (get_user(val, p)) 866 break; 867 val2 = 15; 868 if ((val >> 16) != 0) { 869 val2 = val >> 16; 870 val &= 0xffff; 871 } 872 vj = slhc_init(val2+1, val+1); 873 if (IS_ERR(vj)) { 874 err = PTR_ERR(vj); 875 break; 876 } 877 ppp_lock(ppp); 878 if (ppp->vj) 879 slhc_free(ppp->vj); 880 ppp->vj = vj; 881 ppp_unlock(ppp); 882 err = 0; 883 break; 884 885 case PPPIOCGNPMODE: 886 case PPPIOCSNPMODE: 887 if (copy_from_user(&npi, argp, sizeof(npi))) 888 break; 889 err = proto_to_npindex(npi.protocol); 890 if (err < 0) 891 break; 892 i = err; 893 if (cmd == PPPIOCGNPMODE) { 894 err = -EFAULT; 895 npi.mode = ppp->npmode[i]; 896 if (copy_to_user(argp, &npi, sizeof(npi))) 897 break; 898 } else { 899 ppp->npmode[i] = npi.mode; 900 /* we may be able to transmit more packets now (??) */ 901 netif_wake_queue(ppp->dev); 902 } 903 err = 0; 904 break; 905 906 #ifdef CONFIG_PPP_FILTER 907 case PPPIOCSPASS: 908 case PPPIOCSACTIVE: 909 { 910 struct bpf_prog *filter = ppp_get_filter(argp); 911 struct bpf_prog **which; 912 913 if (IS_ERR(filter)) { 914 err = PTR_ERR(filter); 915 break; 916 } 917 if (cmd == PPPIOCSPASS) 918 which = &ppp->pass_filter; 919 else 920 which = &ppp->active_filter; 921 ppp_lock(ppp); 922 if (*which) 923 bpf_prog_destroy(*which); 924 *which = filter; 925 ppp_unlock(ppp); 926 err = 0; 927 break; 928 } 929 #endif /* CONFIG_PPP_FILTER */ 930 931 #ifdef CONFIG_PPP_MULTILINK 932 case PPPIOCSMRRU: 933 if (get_user(val, p)) 934 break; 935 ppp_recv_lock(ppp); 936 ppp->mrru = val; 937 ppp_recv_unlock(ppp); 938 err = 0; 939 break; 940 #endif /* CONFIG_PPP_MULTILINK */ 941 942 default: 943 err = -ENOTTY; 944 } 945 946 out: 947 mutex_unlock(&ppp_mutex); 948 949 return err; 950 } 951 952 #ifdef CONFIG_COMPAT 953 struct ppp_option_data32 { 954 compat_uptr_t ptr; 955 u32 length; 956 compat_int_t transmit; 957 }; 958 #define PPPIOCSCOMPRESS32 _IOW('t', 77, struct ppp_option_data32) 959 960 static long ppp_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 961 { 962 struct ppp_file *pf; 963 int err = -ENOIOCTLCMD; 964 void __user *argp = (void __user *)arg; 965 966 mutex_lock(&ppp_mutex); 967 968 pf = file->private_data; 969 if (pf && pf->kind == INTERFACE) { 970 struct ppp *ppp = PF_TO_PPP(pf); 971 switch (cmd) { 972 #ifdef CONFIG_PPP_FILTER 973 case PPPIOCSPASS32: 974 case PPPIOCSACTIVE32: 975 { 976 struct bpf_prog *filter = compat_ppp_get_filter(argp); 977 struct bpf_prog **which; 978 979 if (IS_ERR(filter)) { 980 err = PTR_ERR(filter); 981 break; 982 } 983 if (cmd == PPPIOCSPASS32) 984 which = &ppp->pass_filter; 985 else 986 which = &ppp->active_filter; 987 ppp_lock(ppp); 988 if (*which) 989 bpf_prog_destroy(*which); 990 *which = filter; 991 ppp_unlock(ppp); 992 err = 0; 993 break; 994 } 995 #endif /* CONFIG_PPP_FILTER */ 996 case PPPIOCSCOMPRESS32: 997 { 998 struct ppp_option_data32 data32; 999 if (copy_from_user(&data32, argp, sizeof(data32))) { 1000 err = -EFAULT; 1001 } else { 1002 struct ppp_option_data data = { 1003 .ptr = compat_ptr(data32.ptr), 1004 .length = data32.length, 1005 .transmit = data32.transmit 1006 }; 1007 err = ppp_set_compress(ppp, &data); 1008 } 1009 break; 1010 } 1011 } 1012 } 1013 mutex_unlock(&ppp_mutex); 1014 1015 /* all other commands have compatible arguments */ 1016 if (err == -ENOIOCTLCMD) 1017 err = ppp_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); 1018 1019 return err; 1020 } 1021 #endif 1022 1023 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 1024 struct file *file, unsigned int cmd, unsigned long arg) 1025 { 1026 int unit, err = -EFAULT; 1027 struct ppp *ppp; 1028 struct channel *chan; 1029 struct ppp_net *pn; 1030 int __user *p = (int __user *)arg; 1031 1032 switch (cmd) { 1033 case PPPIOCNEWUNIT: 1034 /* Create a new ppp unit */ 1035 if (get_user(unit, p)) 1036 break; 1037 err = ppp_create_interface(net, file, &unit); 1038 if (err < 0) 1039 break; 1040 1041 err = -EFAULT; 1042 if (put_user(unit, p)) 1043 break; 1044 err = 0; 1045 break; 1046 1047 case PPPIOCATTACH: 1048 /* Attach to an existing ppp unit */ 1049 if (get_user(unit, p)) 1050 break; 1051 err = -ENXIO; 1052 pn = ppp_pernet(net); 1053 mutex_lock(&pn->all_ppp_mutex); 1054 ppp = ppp_find_unit(pn, unit); 1055 if (ppp) { 1056 refcount_inc(&ppp->file.refcnt); 1057 file->private_data = &ppp->file; 1058 err = 0; 1059 } 1060 mutex_unlock(&pn->all_ppp_mutex); 1061 break; 1062 1063 case PPPIOCATTCHAN: 1064 if (get_user(unit, p)) 1065 break; 1066 err = -ENXIO; 1067 pn = ppp_pernet(net); 1068 spin_lock_bh(&pn->all_channels_lock); 1069 chan = ppp_find_channel(pn, unit); 1070 if (chan) { 1071 refcount_inc(&chan->file.refcnt); 1072 file->private_data = &chan->file; 1073 err = 0; 1074 } 1075 spin_unlock_bh(&pn->all_channels_lock); 1076 break; 1077 1078 default: 1079 err = -ENOTTY; 1080 } 1081 1082 return err; 1083 } 1084 1085 static const struct file_operations ppp_device_fops = { 1086 .owner = THIS_MODULE, 1087 .read = ppp_read, 1088 .write = ppp_write, 1089 .poll = ppp_poll, 1090 .unlocked_ioctl = ppp_ioctl, 1091 #ifdef CONFIG_COMPAT 1092 .compat_ioctl = ppp_compat_ioctl, 1093 #endif 1094 .open = ppp_open, 1095 .release = ppp_release, 1096 .llseek = noop_llseek, 1097 }; 1098 1099 static __net_init int ppp_init_net(struct net *net) 1100 { 1101 struct ppp_net *pn = net_generic(net, ppp_net_id); 1102 1103 idr_init(&pn->units_idr); 1104 mutex_init(&pn->all_ppp_mutex); 1105 1106 INIT_LIST_HEAD(&pn->all_channels); 1107 INIT_LIST_HEAD(&pn->new_channels); 1108 1109 spin_lock_init(&pn->all_channels_lock); 1110 1111 return 0; 1112 } 1113 1114 static __net_exit void ppp_exit_net(struct net *net) 1115 { 1116 struct ppp_net *pn = net_generic(net, ppp_net_id); 1117 struct net_device *dev; 1118 struct net_device *aux; 1119 struct ppp *ppp; 1120 LIST_HEAD(list); 1121 int id; 1122 1123 rtnl_lock(); 1124 for_each_netdev_safe(net, dev, aux) { 1125 if (dev->netdev_ops == &ppp_netdev_ops) 1126 unregister_netdevice_queue(dev, &list); 1127 } 1128 1129 idr_for_each_entry(&pn->units_idr, ppp, id) 1130 /* Skip devices already unregistered by previous loop */ 1131 if (!net_eq(dev_net(ppp->dev), net)) 1132 unregister_netdevice_queue(ppp->dev, &list); 1133 1134 unregister_netdevice_many(&list); 1135 rtnl_unlock(); 1136 1137 mutex_destroy(&pn->all_ppp_mutex); 1138 idr_destroy(&pn->units_idr); 1139 WARN_ON_ONCE(!list_empty(&pn->all_channels)); 1140 WARN_ON_ONCE(!list_empty(&pn->new_channels)); 1141 } 1142 1143 static struct pernet_operations ppp_net_ops = { 1144 .init = ppp_init_net, 1145 .exit = ppp_exit_net, 1146 .id = &ppp_net_id, 1147 .size = sizeof(struct ppp_net), 1148 }; 1149 1150 static int ppp_unit_register(struct ppp *ppp, int unit, bool ifname_is_set) 1151 { 1152 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 1153 int ret; 1154 1155 mutex_lock(&pn->all_ppp_mutex); 1156 1157 if (unit < 0) { 1158 ret = unit_get(&pn->units_idr, ppp); 1159 if (ret < 0) 1160 goto err; 1161 } else { 1162 /* Caller asked for a specific unit number. Fail with -EEXIST 1163 * if unavailable. For backward compatibility, return -EEXIST 1164 * too if idr allocation fails; this makes pppd retry without 1165 * requesting a specific unit number. 1166 */ 1167 if (unit_find(&pn->units_idr, unit)) { 1168 ret = -EEXIST; 1169 goto err; 1170 } 1171 ret = unit_set(&pn->units_idr, ppp, unit); 1172 if (ret < 0) { 1173 /* Rewrite error for backward compatibility */ 1174 ret = -EEXIST; 1175 goto err; 1176 } 1177 } 1178 ppp->file.index = ret; 1179 1180 if (!ifname_is_set) 1181 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ppp->file.index); 1182 1183 mutex_unlock(&pn->all_ppp_mutex); 1184 1185 ret = register_netdevice(ppp->dev); 1186 if (ret < 0) 1187 goto err_unit; 1188 1189 atomic_inc(&ppp_unit_count); 1190 1191 return 0; 1192 1193 err_unit: 1194 mutex_lock(&pn->all_ppp_mutex); 1195 unit_put(&pn->units_idr, ppp->file.index); 1196 err: 1197 mutex_unlock(&pn->all_ppp_mutex); 1198 1199 return ret; 1200 } 1201 1202 static int ppp_dev_configure(struct net *src_net, struct net_device *dev, 1203 const struct ppp_config *conf) 1204 { 1205 struct ppp *ppp = netdev_priv(dev); 1206 int indx; 1207 int err; 1208 int cpu; 1209 1210 ppp->dev = dev; 1211 ppp->ppp_net = src_net; 1212 ppp->mru = PPP_MRU; 1213 ppp->owner = conf->file; 1214 1215 init_ppp_file(&ppp->file, INTERFACE); 1216 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */ 1217 1218 for (indx = 0; indx < NUM_NP; ++indx) 1219 ppp->npmode[indx] = NPMODE_PASS; 1220 INIT_LIST_HEAD(&ppp->channels); 1221 spin_lock_init(&ppp->rlock); 1222 spin_lock_init(&ppp->wlock); 1223 1224 ppp->xmit_recursion = alloc_percpu(int); 1225 if (!ppp->xmit_recursion) { 1226 err = -ENOMEM; 1227 goto err1; 1228 } 1229 for_each_possible_cpu(cpu) 1230 (*per_cpu_ptr(ppp->xmit_recursion, cpu)) = 0; 1231 1232 #ifdef CONFIG_PPP_MULTILINK 1233 ppp->minseq = -1; 1234 skb_queue_head_init(&ppp->mrq); 1235 #endif /* CONFIG_PPP_MULTILINK */ 1236 #ifdef CONFIG_PPP_FILTER 1237 ppp->pass_filter = NULL; 1238 ppp->active_filter = NULL; 1239 #endif /* CONFIG_PPP_FILTER */ 1240 1241 err = ppp_unit_register(ppp, conf->unit, conf->ifname_is_set); 1242 if (err < 0) 1243 goto err2; 1244 1245 conf->file->private_data = &ppp->file; 1246 1247 return 0; 1248 err2: 1249 free_percpu(ppp->xmit_recursion); 1250 err1: 1251 return err; 1252 } 1253 1254 static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = { 1255 [IFLA_PPP_DEV_FD] = { .type = NLA_S32 }, 1256 }; 1257 1258 static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[], 1259 struct netlink_ext_ack *extack) 1260 { 1261 if (!data) 1262 return -EINVAL; 1263 1264 if (!data[IFLA_PPP_DEV_FD]) 1265 return -EINVAL; 1266 if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0) 1267 return -EBADF; 1268 1269 return 0; 1270 } 1271 1272 static int ppp_nl_newlink(struct net *src_net, struct net_device *dev, 1273 struct nlattr *tb[], struct nlattr *data[], 1274 struct netlink_ext_ack *extack) 1275 { 1276 struct ppp_config conf = { 1277 .unit = -1, 1278 .ifname_is_set = true, 1279 }; 1280 struct file *file; 1281 int err; 1282 1283 file = fget(nla_get_s32(data[IFLA_PPP_DEV_FD])); 1284 if (!file) 1285 return -EBADF; 1286 1287 /* rtnl_lock is already held here, but ppp_create_interface() locks 1288 * ppp_mutex before holding rtnl_lock. Using mutex_trylock() avoids 1289 * possible deadlock due to lock order inversion, at the cost of 1290 * pushing the problem back to userspace. 1291 */ 1292 if (!mutex_trylock(&ppp_mutex)) { 1293 err = -EBUSY; 1294 goto out; 1295 } 1296 1297 if (file->f_op != &ppp_device_fops || file->private_data) { 1298 err = -EBADF; 1299 goto out_unlock; 1300 } 1301 1302 conf.file = file; 1303 1304 /* Don't use device name generated by the rtnetlink layer when ifname 1305 * isn't specified. Let ppp_dev_configure() set the device name using 1306 * the PPP unit identifer as suffix (i.e. ppp<unit_id>). This allows 1307 * userspace to infer the device name using to the PPPIOCGUNIT ioctl. 1308 */ 1309 if (!tb[IFLA_IFNAME]) 1310 conf.ifname_is_set = false; 1311 1312 err = ppp_dev_configure(src_net, dev, &conf); 1313 1314 out_unlock: 1315 mutex_unlock(&ppp_mutex); 1316 out: 1317 fput(file); 1318 1319 return err; 1320 } 1321 1322 static void ppp_nl_dellink(struct net_device *dev, struct list_head *head) 1323 { 1324 unregister_netdevice_queue(dev, head); 1325 } 1326 1327 static size_t ppp_nl_get_size(const struct net_device *dev) 1328 { 1329 return 0; 1330 } 1331 1332 static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev) 1333 { 1334 return 0; 1335 } 1336 1337 static struct net *ppp_nl_get_link_net(const struct net_device *dev) 1338 { 1339 struct ppp *ppp = netdev_priv(dev); 1340 1341 return ppp->ppp_net; 1342 } 1343 1344 static struct rtnl_link_ops ppp_link_ops __read_mostly = { 1345 .kind = "ppp", 1346 .maxtype = IFLA_PPP_MAX, 1347 .policy = ppp_nl_policy, 1348 .priv_size = sizeof(struct ppp), 1349 .setup = ppp_setup, 1350 .validate = ppp_nl_validate, 1351 .newlink = ppp_nl_newlink, 1352 .dellink = ppp_nl_dellink, 1353 .get_size = ppp_nl_get_size, 1354 .fill_info = ppp_nl_fill_info, 1355 .get_link_net = ppp_nl_get_link_net, 1356 }; 1357 1358 #define PPP_MAJOR 108 1359 1360 /* Called at boot time if ppp is compiled into the kernel, 1361 or at module load time (from init_module) if compiled as a module. */ 1362 static int __init ppp_init(void) 1363 { 1364 int err; 1365 1366 pr_info("PPP generic driver version " PPP_VERSION "\n"); 1367 1368 err = register_pernet_device(&ppp_net_ops); 1369 if (err) { 1370 pr_err("failed to register PPP pernet device (%d)\n", err); 1371 goto out; 1372 } 1373 1374 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops); 1375 if (err) { 1376 pr_err("failed to register PPP device (%d)\n", err); 1377 goto out_net; 1378 } 1379 1380 ppp_class = class_create(THIS_MODULE, "ppp"); 1381 if (IS_ERR(ppp_class)) { 1382 err = PTR_ERR(ppp_class); 1383 goto out_chrdev; 1384 } 1385 1386 err = rtnl_link_register(&ppp_link_ops); 1387 if (err) { 1388 pr_err("failed to register rtnetlink PPP handler\n"); 1389 goto out_class; 1390 } 1391 1392 /* not a big deal if we fail here :-) */ 1393 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp"); 1394 1395 return 0; 1396 1397 out_class: 1398 class_destroy(ppp_class); 1399 out_chrdev: 1400 unregister_chrdev(PPP_MAJOR, "ppp"); 1401 out_net: 1402 unregister_pernet_device(&ppp_net_ops); 1403 out: 1404 return err; 1405 } 1406 1407 /* 1408 * Network interface unit routines. 1409 */ 1410 static netdev_tx_t 1411 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev) 1412 { 1413 struct ppp *ppp = netdev_priv(dev); 1414 int npi, proto; 1415 unsigned char *pp; 1416 1417 npi = ethertype_to_npindex(ntohs(skb->protocol)); 1418 if (npi < 0) 1419 goto outf; 1420 1421 /* Drop, accept or reject the packet */ 1422 switch (ppp->npmode[npi]) { 1423 case NPMODE_PASS: 1424 break; 1425 case NPMODE_QUEUE: 1426 /* it would be nice to have a way to tell the network 1427 system to queue this one up for later. */ 1428 goto outf; 1429 case NPMODE_DROP: 1430 case NPMODE_ERROR: 1431 goto outf; 1432 } 1433 1434 /* Put the 2-byte PPP protocol number on the front, 1435 making sure there is room for the address and control fields. */ 1436 if (skb_cow_head(skb, PPP_HDRLEN)) 1437 goto outf; 1438 1439 pp = skb_push(skb, 2); 1440 proto = npindex_to_proto[npi]; 1441 put_unaligned_be16(proto, pp); 1442 1443 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev))); 1444 ppp_xmit_process(ppp, skb); 1445 1446 return NETDEV_TX_OK; 1447 1448 outf: 1449 kfree_skb(skb); 1450 ++dev->stats.tx_dropped; 1451 return NETDEV_TX_OK; 1452 } 1453 1454 static int 1455 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 1456 { 1457 struct ppp *ppp = netdev_priv(dev); 1458 int err = -EFAULT; 1459 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data; 1460 struct ppp_stats stats; 1461 struct ppp_comp_stats cstats; 1462 char *vers; 1463 1464 switch (cmd) { 1465 case SIOCGPPPSTATS: 1466 ppp_get_stats(ppp, &stats); 1467 if (copy_to_user(addr, &stats, sizeof(stats))) 1468 break; 1469 err = 0; 1470 break; 1471 1472 case SIOCGPPPCSTATS: 1473 memset(&cstats, 0, sizeof(cstats)); 1474 if (ppp->xc_state) 1475 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c); 1476 if (ppp->rc_state) 1477 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d); 1478 if (copy_to_user(addr, &cstats, sizeof(cstats))) 1479 break; 1480 err = 0; 1481 break; 1482 1483 case SIOCGPPPVER: 1484 vers = PPP_VERSION; 1485 if (copy_to_user(addr, vers, strlen(vers) + 1)) 1486 break; 1487 err = 0; 1488 break; 1489 1490 default: 1491 err = -EINVAL; 1492 } 1493 1494 return err; 1495 } 1496 1497 static void 1498 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64) 1499 { 1500 struct ppp *ppp = netdev_priv(dev); 1501 1502 ppp_recv_lock(ppp); 1503 stats64->rx_packets = ppp->stats64.rx_packets; 1504 stats64->rx_bytes = ppp->stats64.rx_bytes; 1505 ppp_recv_unlock(ppp); 1506 1507 ppp_xmit_lock(ppp); 1508 stats64->tx_packets = ppp->stats64.tx_packets; 1509 stats64->tx_bytes = ppp->stats64.tx_bytes; 1510 ppp_xmit_unlock(ppp); 1511 1512 stats64->rx_errors = dev->stats.rx_errors; 1513 stats64->tx_errors = dev->stats.tx_errors; 1514 stats64->rx_dropped = dev->stats.rx_dropped; 1515 stats64->tx_dropped = dev->stats.tx_dropped; 1516 stats64->rx_length_errors = dev->stats.rx_length_errors; 1517 } 1518 1519 static int ppp_dev_init(struct net_device *dev) 1520 { 1521 struct ppp *ppp; 1522 1523 netdev_lockdep_set_classes(dev); 1524 1525 ppp = netdev_priv(dev); 1526 /* Let the netdevice take a reference on the ppp file. This ensures 1527 * that ppp_destroy_interface() won't run before the device gets 1528 * unregistered. 1529 */ 1530 refcount_inc(&ppp->file.refcnt); 1531 1532 return 0; 1533 } 1534 1535 static void ppp_dev_uninit(struct net_device *dev) 1536 { 1537 struct ppp *ppp = netdev_priv(dev); 1538 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 1539 1540 ppp_lock(ppp); 1541 ppp->closing = 1; 1542 ppp_unlock(ppp); 1543 1544 mutex_lock(&pn->all_ppp_mutex); 1545 unit_put(&pn->units_idr, ppp->file.index); 1546 mutex_unlock(&pn->all_ppp_mutex); 1547 1548 ppp->owner = NULL; 1549 1550 ppp->file.dead = 1; 1551 wake_up_interruptible(&ppp->file.rwait); 1552 } 1553 1554 static void ppp_dev_priv_destructor(struct net_device *dev) 1555 { 1556 struct ppp *ppp; 1557 1558 ppp = netdev_priv(dev); 1559 if (refcount_dec_and_test(&ppp->file.refcnt)) 1560 ppp_destroy_interface(ppp); 1561 } 1562 1563 static int ppp_fill_forward_path(struct net_device_path_ctx *ctx, 1564 struct net_device_path *path) 1565 { 1566 struct ppp *ppp = netdev_priv(ctx->dev); 1567 struct ppp_channel *chan; 1568 struct channel *pch; 1569 1570 if (ppp->flags & SC_MULTILINK) 1571 return -EOPNOTSUPP; 1572 1573 if (list_empty(&ppp->channels)) 1574 return -ENODEV; 1575 1576 pch = list_first_entry(&ppp->channels, struct channel, clist); 1577 chan = pch->chan; 1578 if (!chan->ops->fill_forward_path) 1579 return -EOPNOTSUPP; 1580 1581 return chan->ops->fill_forward_path(ctx, path, chan); 1582 } 1583 1584 static const struct net_device_ops ppp_netdev_ops = { 1585 .ndo_init = ppp_dev_init, 1586 .ndo_uninit = ppp_dev_uninit, 1587 .ndo_start_xmit = ppp_start_xmit, 1588 .ndo_do_ioctl = ppp_net_ioctl, 1589 .ndo_get_stats64 = ppp_get_stats64, 1590 .ndo_fill_forward_path = ppp_fill_forward_path, 1591 }; 1592 1593 static struct device_type ppp_type = { 1594 .name = "ppp", 1595 }; 1596 1597 static void ppp_setup(struct net_device *dev) 1598 { 1599 dev->netdev_ops = &ppp_netdev_ops; 1600 SET_NETDEV_DEVTYPE(dev, &ppp_type); 1601 1602 dev->features |= NETIF_F_LLTX; 1603 1604 dev->hard_header_len = PPP_HDRLEN; 1605 dev->mtu = PPP_MRU; 1606 dev->addr_len = 0; 1607 dev->tx_queue_len = 3; 1608 dev->type = ARPHRD_PPP; 1609 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 1610 dev->priv_destructor = ppp_dev_priv_destructor; 1611 netif_keep_dst(dev); 1612 } 1613 1614 /* 1615 * Transmit-side routines. 1616 */ 1617 1618 /* Called to do any work queued up on the transmit side that can now be done */ 1619 static void __ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb) 1620 { 1621 ppp_xmit_lock(ppp); 1622 if (!ppp->closing) { 1623 ppp_push(ppp); 1624 1625 if (skb) 1626 skb_queue_tail(&ppp->file.xq, skb); 1627 while (!ppp->xmit_pending && 1628 (skb = skb_dequeue(&ppp->file.xq))) 1629 ppp_send_frame(ppp, skb); 1630 /* If there's no work left to do, tell the core net 1631 code that we can accept some more. */ 1632 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq)) 1633 netif_wake_queue(ppp->dev); 1634 else 1635 netif_stop_queue(ppp->dev); 1636 } else { 1637 kfree_skb(skb); 1638 } 1639 ppp_xmit_unlock(ppp); 1640 } 1641 1642 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb) 1643 { 1644 local_bh_disable(); 1645 1646 if (unlikely(*this_cpu_ptr(ppp->xmit_recursion))) 1647 goto err; 1648 1649 (*this_cpu_ptr(ppp->xmit_recursion))++; 1650 __ppp_xmit_process(ppp, skb); 1651 (*this_cpu_ptr(ppp->xmit_recursion))--; 1652 1653 local_bh_enable(); 1654 1655 return; 1656 1657 err: 1658 local_bh_enable(); 1659 1660 kfree_skb(skb); 1661 1662 if (net_ratelimit()) 1663 netdev_err(ppp->dev, "recursion detected\n"); 1664 } 1665 1666 static inline struct sk_buff * 1667 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) 1668 { 1669 struct sk_buff *new_skb; 1670 int len; 1671 int new_skb_size = ppp->dev->mtu + 1672 ppp->xcomp->comp_extra + ppp->dev->hard_header_len; 1673 int compressor_skb_size = ppp->dev->mtu + 1674 ppp->xcomp->comp_extra + PPP_HDRLEN; 1675 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC); 1676 if (!new_skb) { 1677 if (net_ratelimit()) 1678 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n"); 1679 return NULL; 1680 } 1681 if (ppp->dev->hard_header_len > PPP_HDRLEN) 1682 skb_reserve(new_skb, 1683 ppp->dev->hard_header_len - PPP_HDRLEN); 1684 1685 /* compressor still expects A/C bytes in hdr */ 1686 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, 1687 new_skb->data, skb->len + 2, 1688 compressor_skb_size); 1689 if (len > 0 && (ppp->flags & SC_CCP_UP)) { 1690 consume_skb(skb); 1691 skb = new_skb; 1692 skb_put(skb, len); 1693 skb_pull(skb, 2); /* pull off A/C bytes */ 1694 } else if (len == 0) { 1695 /* didn't compress, or CCP not up yet */ 1696 consume_skb(new_skb); 1697 new_skb = skb; 1698 } else { 1699 /* 1700 * (len < 0) 1701 * MPPE requires that we do not send unencrypted 1702 * frames. The compressor will return -1 if we 1703 * should drop the frame. We cannot simply test 1704 * the compress_proto because MPPE and MPPC share 1705 * the same number. 1706 */ 1707 if (net_ratelimit()) 1708 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n"); 1709 kfree_skb(skb); 1710 consume_skb(new_skb); 1711 new_skb = NULL; 1712 } 1713 return new_skb; 1714 } 1715 1716 /* 1717 * Compress and send a frame. 1718 * The caller should have locked the xmit path, 1719 * and xmit_pending should be 0. 1720 */ 1721 static void 1722 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) 1723 { 1724 int proto = PPP_PROTO(skb); 1725 struct sk_buff *new_skb; 1726 int len; 1727 unsigned char *cp; 1728 1729 if (proto < 0x8000) { 1730 #ifdef CONFIG_PPP_FILTER 1731 /* check if we should pass this packet */ 1732 /* the filter instructions are constructed assuming 1733 a four-byte PPP header on each packet */ 1734 *(u8 *)skb_push(skb, 2) = 1; 1735 if (ppp->pass_filter && 1736 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 1737 if (ppp->debug & 1) 1738 netdev_printk(KERN_DEBUG, ppp->dev, 1739 "PPP: outbound frame " 1740 "not passed\n"); 1741 kfree_skb(skb); 1742 return; 1743 } 1744 /* if this packet passes the active filter, record the time */ 1745 if (!(ppp->active_filter && 1746 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 1747 ppp->last_xmit = jiffies; 1748 skb_pull(skb, 2); 1749 #else 1750 /* for data packets, record the time */ 1751 ppp->last_xmit = jiffies; 1752 #endif /* CONFIG_PPP_FILTER */ 1753 } 1754 1755 ++ppp->stats64.tx_packets; 1756 ppp->stats64.tx_bytes += skb->len - 2; 1757 1758 switch (proto) { 1759 case PPP_IP: 1760 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0) 1761 break; 1762 /* try to do VJ TCP header compression */ 1763 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2, 1764 GFP_ATOMIC); 1765 if (!new_skb) { 1766 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n"); 1767 goto drop; 1768 } 1769 skb_reserve(new_skb, ppp->dev->hard_header_len - 2); 1770 cp = skb->data + 2; 1771 len = slhc_compress(ppp->vj, cp, skb->len - 2, 1772 new_skb->data + 2, &cp, 1773 !(ppp->flags & SC_NO_TCP_CCID)); 1774 if (cp == skb->data + 2) { 1775 /* didn't compress */ 1776 consume_skb(new_skb); 1777 } else { 1778 if (cp[0] & SL_TYPE_COMPRESSED_TCP) { 1779 proto = PPP_VJC_COMP; 1780 cp[0] &= ~SL_TYPE_COMPRESSED_TCP; 1781 } else { 1782 proto = PPP_VJC_UNCOMP; 1783 cp[0] = skb->data[2]; 1784 } 1785 consume_skb(skb); 1786 skb = new_skb; 1787 cp = skb_put(skb, len + 2); 1788 cp[0] = 0; 1789 cp[1] = proto; 1790 } 1791 break; 1792 1793 case PPP_CCP: 1794 /* peek at outbound CCP frames */ 1795 ppp_ccp_peek(ppp, skb, 0); 1796 break; 1797 } 1798 1799 /* try to do packet compression */ 1800 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state && 1801 proto != PPP_LCP && proto != PPP_CCP) { 1802 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) { 1803 if (net_ratelimit()) 1804 netdev_err(ppp->dev, 1805 "ppp: compression required but " 1806 "down - pkt dropped.\n"); 1807 goto drop; 1808 } 1809 skb = pad_compress_skb(ppp, skb); 1810 if (!skb) 1811 goto drop; 1812 } 1813 1814 /* 1815 * If we are waiting for traffic (demand dialling), 1816 * queue it up for pppd to receive. 1817 */ 1818 if (ppp->flags & SC_LOOP_TRAFFIC) { 1819 if (ppp->file.rq.qlen > PPP_MAX_RQLEN) 1820 goto drop; 1821 skb_queue_tail(&ppp->file.rq, skb); 1822 wake_up_interruptible(&ppp->file.rwait); 1823 return; 1824 } 1825 1826 ppp->xmit_pending = skb; 1827 ppp_push(ppp); 1828 return; 1829 1830 drop: 1831 kfree_skb(skb); 1832 ++ppp->dev->stats.tx_errors; 1833 } 1834 1835 /* 1836 * Try to send the frame in xmit_pending. 1837 * The caller should have the xmit path locked. 1838 */ 1839 static void 1840 ppp_push(struct ppp *ppp) 1841 { 1842 struct list_head *list; 1843 struct channel *pch; 1844 struct sk_buff *skb = ppp->xmit_pending; 1845 1846 if (!skb) 1847 return; 1848 1849 list = &ppp->channels; 1850 if (list_empty(list)) { 1851 /* nowhere to send the packet, just drop it */ 1852 ppp->xmit_pending = NULL; 1853 kfree_skb(skb); 1854 return; 1855 } 1856 1857 if ((ppp->flags & SC_MULTILINK) == 0) { 1858 /* not doing multilink: send it down the first channel */ 1859 list = list->next; 1860 pch = list_entry(list, struct channel, clist); 1861 1862 spin_lock(&pch->downl); 1863 if (pch->chan) { 1864 if (pch->chan->ops->start_xmit(pch->chan, skb)) 1865 ppp->xmit_pending = NULL; 1866 } else { 1867 /* channel got unregistered */ 1868 kfree_skb(skb); 1869 ppp->xmit_pending = NULL; 1870 } 1871 spin_unlock(&pch->downl); 1872 return; 1873 } 1874 1875 #ifdef CONFIG_PPP_MULTILINK 1876 /* Multilink: fragment the packet over as many links 1877 as can take the packet at the moment. */ 1878 if (!ppp_mp_explode(ppp, skb)) 1879 return; 1880 #endif /* CONFIG_PPP_MULTILINK */ 1881 1882 ppp->xmit_pending = NULL; 1883 kfree_skb(skb); 1884 } 1885 1886 #ifdef CONFIG_PPP_MULTILINK 1887 static bool mp_protocol_compress __read_mostly = true; 1888 module_param(mp_protocol_compress, bool, 0644); 1889 MODULE_PARM_DESC(mp_protocol_compress, 1890 "compress protocol id in multilink fragments"); 1891 1892 /* 1893 * Divide a packet to be transmitted into fragments and 1894 * send them out the individual links. 1895 */ 1896 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb) 1897 { 1898 int len, totlen; 1899 int i, bits, hdrlen, mtu; 1900 int flen; 1901 int navail, nfree, nzero; 1902 int nbigger; 1903 int totspeed; 1904 int totfree; 1905 unsigned char *p, *q; 1906 struct list_head *list; 1907 struct channel *pch; 1908 struct sk_buff *frag; 1909 struct ppp_channel *chan; 1910 1911 totspeed = 0; /*total bitrate of the bundle*/ 1912 nfree = 0; /* # channels which have no packet already queued */ 1913 navail = 0; /* total # of usable channels (not deregistered) */ 1914 nzero = 0; /* number of channels with zero speed associated*/ 1915 totfree = 0; /*total # of channels available and 1916 *having no queued packets before 1917 *starting the fragmentation*/ 1918 1919 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1920 i = 0; 1921 list_for_each_entry(pch, &ppp->channels, clist) { 1922 if (pch->chan) { 1923 pch->avail = 1; 1924 navail++; 1925 pch->speed = pch->chan->speed; 1926 } else { 1927 pch->avail = 0; 1928 } 1929 if (pch->avail) { 1930 if (skb_queue_empty(&pch->file.xq) || 1931 !pch->had_frag) { 1932 if (pch->speed == 0) 1933 nzero++; 1934 else 1935 totspeed += pch->speed; 1936 1937 pch->avail = 2; 1938 ++nfree; 1939 ++totfree; 1940 } 1941 if (!pch->had_frag && i < ppp->nxchan) 1942 ppp->nxchan = i; 1943 } 1944 ++i; 1945 } 1946 /* 1947 * Don't start sending this packet unless at least half of 1948 * the channels are free. This gives much better TCP 1949 * performance if we have a lot of channels. 1950 */ 1951 if (nfree == 0 || nfree < navail / 2) 1952 return 0; /* can't take now, leave it in xmit_pending */ 1953 1954 /* Do protocol field compression */ 1955 p = skb->data; 1956 len = skb->len; 1957 if (*p == 0 && mp_protocol_compress) { 1958 ++p; 1959 --len; 1960 } 1961 1962 totlen = len; 1963 nbigger = len % nfree; 1964 1965 /* skip to the channel after the one we last used 1966 and start at that one */ 1967 list = &ppp->channels; 1968 for (i = 0; i < ppp->nxchan; ++i) { 1969 list = list->next; 1970 if (list == &ppp->channels) { 1971 i = 0; 1972 break; 1973 } 1974 } 1975 1976 /* create a fragment for each channel */ 1977 bits = B; 1978 while (len > 0) { 1979 list = list->next; 1980 if (list == &ppp->channels) { 1981 i = 0; 1982 continue; 1983 } 1984 pch = list_entry(list, struct channel, clist); 1985 ++i; 1986 if (!pch->avail) 1987 continue; 1988 1989 /* 1990 * Skip this channel if it has a fragment pending already and 1991 * we haven't given a fragment to all of the free channels. 1992 */ 1993 if (pch->avail == 1) { 1994 if (nfree > 0) 1995 continue; 1996 } else { 1997 pch->avail = 1; 1998 } 1999 2000 /* check the channel's mtu and whether it is still attached. */ 2001 spin_lock(&pch->downl); 2002 if (pch->chan == NULL) { 2003 /* can't use this channel, it's being deregistered */ 2004 if (pch->speed == 0) 2005 nzero--; 2006 else 2007 totspeed -= pch->speed; 2008 2009 spin_unlock(&pch->downl); 2010 pch->avail = 0; 2011 totlen = len; 2012 totfree--; 2013 nfree--; 2014 if (--navail == 0) 2015 break; 2016 continue; 2017 } 2018 2019 /* 2020 *if the channel speed is not set divide 2021 *the packet evenly among the free channels; 2022 *otherwise divide it according to the speed 2023 *of the channel we are going to transmit on 2024 */ 2025 flen = len; 2026 if (nfree > 0) { 2027 if (pch->speed == 0) { 2028 flen = len/nfree; 2029 if (nbigger > 0) { 2030 flen++; 2031 nbigger--; 2032 } 2033 } else { 2034 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) / 2035 ((totspeed*totfree)/pch->speed)) - hdrlen; 2036 if (nbigger > 0) { 2037 flen += ((totfree - nzero)*pch->speed)/totspeed; 2038 nbigger -= ((totfree - nzero)*pch->speed)/ 2039 totspeed; 2040 } 2041 } 2042 nfree--; 2043 } 2044 2045 /* 2046 *check if we are on the last channel or 2047 *we exceded the length of the data to 2048 *fragment 2049 */ 2050 if ((nfree <= 0) || (flen > len)) 2051 flen = len; 2052 /* 2053 *it is not worth to tx on slow channels: 2054 *in that case from the resulting flen according to the 2055 *above formula will be equal or less than zero. 2056 *Skip the channel in this case 2057 */ 2058 if (flen <= 0) { 2059 pch->avail = 2; 2060 spin_unlock(&pch->downl); 2061 continue; 2062 } 2063 2064 /* 2065 * hdrlen includes the 2-byte PPP protocol field, but the 2066 * MTU counts only the payload excluding the protocol field. 2067 * (RFC1661 Section 2) 2068 */ 2069 mtu = pch->chan->mtu - (hdrlen - 2); 2070 if (mtu < 4) 2071 mtu = 4; 2072 if (flen > mtu) 2073 flen = mtu; 2074 if (flen == len) 2075 bits |= E; 2076 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC); 2077 if (!frag) 2078 goto noskb; 2079 q = skb_put(frag, flen + hdrlen); 2080 2081 /* make the MP header */ 2082 put_unaligned_be16(PPP_MP, q); 2083 if (ppp->flags & SC_MP_XSHORTSEQ) { 2084 q[2] = bits + ((ppp->nxseq >> 8) & 0xf); 2085 q[3] = ppp->nxseq; 2086 } else { 2087 q[2] = bits; 2088 q[3] = ppp->nxseq >> 16; 2089 q[4] = ppp->nxseq >> 8; 2090 q[5] = ppp->nxseq; 2091 } 2092 2093 memcpy(q + hdrlen, p, flen); 2094 2095 /* try to send it down the channel */ 2096 chan = pch->chan; 2097 if (!skb_queue_empty(&pch->file.xq) || 2098 !chan->ops->start_xmit(chan, frag)) 2099 skb_queue_tail(&pch->file.xq, frag); 2100 pch->had_frag = 1; 2101 p += flen; 2102 len -= flen; 2103 ++ppp->nxseq; 2104 bits = 0; 2105 spin_unlock(&pch->downl); 2106 } 2107 ppp->nxchan = i; 2108 2109 return 1; 2110 2111 noskb: 2112 spin_unlock(&pch->downl); 2113 if (ppp->debug & 1) 2114 netdev_err(ppp->dev, "PPP: no memory (fragment)\n"); 2115 ++ppp->dev->stats.tx_errors; 2116 ++ppp->nxseq; 2117 return 1; /* abandon the frame */ 2118 } 2119 #endif /* CONFIG_PPP_MULTILINK */ 2120 2121 /* Try to send data out on a channel */ 2122 static void __ppp_channel_push(struct channel *pch) 2123 { 2124 struct sk_buff *skb; 2125 struct ppp *ppp; 2126 2127 spin_lock(&pch->downl); 2128 if (pch->chan) { 2129 while (!skb_queue_empty(&pch->file.xq)) { 2130 skb = skb_dequeue(&pch->file.xq); 2131 if (!pch->chan->ops->start_xmit(pch->chan, skb)) { 2132 /* put the packet back and try again later */ 2133 skb_queue_head(&pch->file.xq, skb); 2134 break; 2135 } 2136 } 2137 } else { 2138 /* channel got deregistered */ 2139 skb_queue_purge(&pch->file.xq); 2140 } 2141 spin_unlock(&pch->downl); 2142 /* see if there is anything from the attached unit to be sent */ 2143 if (skb_queue_empty(&pch->file.xq)) { 2144 ppp = pch->ppp; 2145 if (ppp) 2146 __ppp_xmit_process(ppp, NULL); 2147 } 2148 } 2149 2150 static void ppp_channel_push(struct channel *pch) 2151 { 2152 read_lock_bh(&pch->upl); 2153 if (pch->ppp) { 2154 (*this_cpu_ptr(pch->ppp->xmit_recursion))++; 2155 __ppp_channel_push(pch); 2156 (*this_cpu_ptr(pch->ppp->xmit_recursion))--; 2157 } else { 2158 __ppp_channel_push(pch); 2159 } 2160 read_unlock_bh(&pch->upl); 2161 } 2162 2163 /* 2164 * Receive-side routines. 2165 */ 2166 2167 struct ppp_mp_skb_parm { 2168 u32 sequence; 2169 u8 BEbits; 2170 }; 2171 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb)) 2172 2173 static inline void 2174 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2175 { 2176 ppp_recv_lock(ppp); 2177 if (!ppp->closing) 2178 ppp_receive_frame(ppp, skb, pch); 2179 else 2180 kfree_skb(skb); 2181 ppp_recv_unlock(ppp); 2182 } 2183 2184 /** 2185 * __ppp_decompress_proto - Decompress protocol field, slim version. 2186 * @skb: Socket buffer where protocol field should be decompressed. It must have 2187 * at least 1 byte of head room and 1 byte of linear data. First byte of 2188 * data must be a protocol field byte. 2189 * 2190 * Decompress protocol field in PPP header if it's compressed, e.g. when 2191 * Protocol-Field-Compression (PFC) was negotiated. No checks w.r.t. skb data 2192 * length are done in this function. 2193 */ 2194 static void __ppp_decompress_proto(struct sk_buff *skb) 2195 { 2196 if (skb->data[0] & 0x01) 2197 *(u8 *)skb_push(skb, 1) = 0x00; 2198 } 2199 2200 /** 2201 * ppp_decompress_proto - Check skb data room and decompress protocol field. 2202 * @skb: Socket buffer where protocol field should be decompressed. First byte 2203 * of data must be a protocol field byte. 2204 * 2205 * Decompress protocol field in PPP header if it's compressed, e.g. when 2206 * Protocol-Field-Compression (PFC) was negotiated. This function also makes 2207 * sure that skb data room is sufficient for Protocol field, before and after 2208 * decompression. 2209 * 2210 * Return: true - decompressed successfully, false - not enough room in skb. 2211 */ 2212 static bool ppp_decompress_proto(struct sk_buff *skb) 2213 { 2214 /* At least one byte should be present (if protocol is compressed) */ 2215 if (!pskb_may_pull(skb, 1)) 2216 return false; 2217 2218 __ppp_decompress_proto(skb); 2219 2220 /* Protocol field should occupy 2 bytes when not compressed */ 2221 return pskb_may_pull(skb, 2); 2222 } 2223 2224 /* Attempt to handle a frame via. a bridged channel, if one exists. 2225 * If the channel is bridged, the frame is consumed by the bridge. 2226 * If not, the caller must handle the frame by normal recv mechanisms. 2227 * Returns true if the frame is consumed, false otherwise. 2228 */ 2229 static bool ppp_channel_bridge_input(struct channel *pch, struct sk_buff *skb) 2230 { 2231 struct channel *pchb; 2232 2233 rcu_read_lock(); 2234 pchb = rcu_dereference(pch->bridge); 2235 if (!pchb) 2236 goto out_rcu; 2237 2238 spin_lock(&pchb->downl); 2239 if (!pchb->chan) { 2240 /* channel got unregistered */ 2241 kfree_skb(skb); 2242 goto outl; 2243 } 2244 2245 skb_scrub_packet(skb, !net_eq(pch->chan_net, pchb->chan_net)); 2246 if (!pchb->chan->ops->start_xmit(pchb->chan, skb)) 2247 kfree_skb(skb); 2248 2249 outl: 2250 spin_unlock(&pchb->downl); 2251 out_rcu: 2252 rcu_read_unlock(); 2253 2254 /* If pchb is set then we've consumed the packet */ 2255 return !!pchb; 2256 } 2257 2258 void 2259 ppp_input(struct ppp_channel *chan, struct sk_buff *skb) 2260 { 2261 struct channel *pch = chan->ppp; 2262 int proto; 2263 2264 if (!pch) { 2265 kfree_skb(skb); 2266 return; 2267 } 2268 2269 /* If the channel is bridged, transmit via. bridge */ 2270 if (ppp_channel_bridge_input(pch, skb)) 2271 return; 2272 2273 read_lock_bh(&pch->upl); 2274 if (!ppp_decompress_proto(skb)) { 2275 kfree_skb(skb); 2276 if (pch->ppp) { 2277 ++pch->ppp->dev->stats.rx_length_errors; 2278 ppp_receive_error(pch->ppp); 2279 } 2280 goto done; 2281 } 2282 2283 proto = PPP_PROTO(skb); 2284 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) { 2285 /* put it on the channel queue */ 2286 skb_queue_tail(&pch->file.rq, skb); 2287 /* drop old frames if queue too long */ 2288 while (pch->file.rq.qlen > PPP_MAX_RQLEN && 2289 (skb = skb_dequeue(&pch->file.rq))) 2290 kfree_skb(skb); 2291 wake_up_interruptible(&pch->file.rwait); 2292 } else { 2293 ppp_do_recv(pch->ppp, skb, pch); 2294 } 2295 2296 done: 2297 read_unlock_bh(&pch->upl); 2298 } 2299 2300 /* Put a 0-length skb in the receive queue as an error indication */ 2301 void 2302 ppp_input_error(struct ppp_channel *chan, int code) 2303 { 2304 struct channel *pch = chan->ppp; 2305 struct sk_buff *skb; 2306 2307 if (!pch) 2308 return; 2309 2310 read_lock_bh(&pch->upl); 2311 if (pch->ppp) { 2312 skb = alloc_skb(0, GFP_ATOMIC); 2313 if (skb) { 2314 skb->len = 0; /* probably unnecessary */ 2315 skb->cb[0] = code; 2316 ppp_do_recv(pch->ppp, skb, pch); 2317 } 2318 } 2319 read_unlock_bh(&pch->upl); 2320 } 2321 2322 /* 2323 * We come in here to process a received frame. 2324 * The receive side of the ppp unit is locked. 2325 */ 2326 static void 2327 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2328 { 2329 /* note: a 0-length skb is used as an error indication */ 2330 if (skb->len > 0) { 2331 skb_checksum_complete_unset(skb); 2332 #ifdef CONFIG_PPP_MULTILINK 2333 /* XXX do channel-level decompression here */ 2334 if (PPP_PROTO(skb) == PPP_MP) 2335 ppp_receive_mp_frame(ppp, skb, pch); 2336 else 2337 #endif /* CONFIG_PPP_MULTILINK */ 2338 ppp_receive_nonmp_frame(ppp, skb); 2339 } else { 2340 kfree_skb(skb); 2341 ppp_receive_error(ppp); 2342 } 2343 } 2344 2345 static void 2346 ppp_receive_error(struct ppp *ppp) 2347 { 2348 ++ppp->dev->stats.rx_errors; 2349 if (ppp->vj) 2350 slhc_toss(ppp->vj); 2351 } 2352 2353 static void 2354 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) 2355 { 2356 struct sk_buff *ns; 2357 int proto, len, npi; 2358 2359 /* 2360 * Decompress the frame, if compressed. 2361 * Note that some decompressors need to see uncompressed frames 2362 * that come in as well as compressed frames. 2363 */ 2364 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) && 2365 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0) 2366 skb = ppp_decompress_frame(ppp, skb); 2367 2368 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR) 2369 goto err; 2370 2371 /* At this point the "Protocol" field MUST be decompressed, either in 2372 * ppp_input(), ppp_decompress_frame() or in ppp_receive_mp_frame(). 2373 */ 2374 proto = PPP_PROTO(skb); 2375 switch (proto) { 2376 case PPP_VJC_COMP: 2377 /* decompress VJ compressed packets */ 2378 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 2379 goto err; 2380 2381 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) { 2382 /* copy to a new sk_buff with more tailroom */ 2383 ns = dev_alloc_skb(skb->len + 128); 2384 if (!ns) { 2385 netdev_err(ppp->dev, "PPP: no memory " 2386 "(VJ decomp)\n"); 2387 goto err; 2388 } 2389 skb_reserve(ns, 2); 2390 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len); 2391 consume_skb(skb); 2392 skb = ns; 2393 } 2394 else 2395 skb->ip_summed = CHECKSUM_NONE; 2396 2397 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2); 2398 if (len <= 0) { 2399 netdev_printk(KERN_DEBUG, ppp->dev, 2400 "PPP: VJ decompression error\n"); 2401 goto err; 2402 } 2403 len += 2; 2404 if (len > skb->len) 2405 skb_put(skb, len - skb->len); 2406 else if (len < skb->len) 2407 skb_trim(skb, len); 2408 proto = PPP_IP; 2409 break; 2410 2411 case PPP_VJC_UNCOMP: 2412 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 2413 goto err; 2414 2415 /* Until we fix the decompressor need to make sure 2416 * data portion is linear. 2417 */ 2418 if (!pskb_may_pull(skb, skb->len)) 2419 goto err; 2420 2421 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) { 2422 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n"); 2423 goto err; 2424 } 2425 proto = PPP_IP; 2426 break; 2427 2428 case PPP_CCP: 2429 ppp_ccp_peek(ppp, skb, 1); 2430 break; 2431 } 2432 2433 ++ppp->stats64.rx_packets; 2434 ppp->stats64.rx_bytes += skb->len - 2; 2435 2436 npi = proto_to_npindex(proto); 2437 if (npi < 0) { 2438 /* control or unknown frame - pass it to pppd */ 2439 skb_queue_tail(&ppp->file.rq, skb); 2440 /* limit queue length by dropping old frames */ 2441 while (ppp->file.rq.qlen > PPP_MAX_RQLEN && 2442 (skb = skb_dequeue(&ppp->file.rq))) 2443 kfree_skb(skb); 2444 /* wake up any process polling or blocking on read */ 2445 wake_up_interruptible(&ppp->file.rwait); 2446 2447 } else { 2448 /* network protocol frame - give it to the kernel */ 2449 2450 #ifdef CONFIG_PPP_FILTER 2451 /* check if the packet passes the pass and active filters */ 2452 /* the filter instructions are constructed assuming 2453 a four-byte PPP header on each packet */ 2454 if (ppp->pass_filter || ppp->active_filter) { 2455 if (skb_unclone(skb, GFP_ATOMIC)) 2456 goto err; 2457 2458 *(u8 *)skb_push(skb, 2) = 0; 2459 if (ppp->pass_filter && 2460 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 2461 if (ppp->debug & 1) 2462 netdev_printk(KERN_DEBUG, ppp->dev, 2463 "PPP: inbound frame " 2464 "not passed\n"); 2465 kfree_skb(skb); 2466 return; 2467 } 2468 if (!(ppp->active_filter && 2469 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 2470 ppp->last_recv = jiffies; 2471 __skb_pull(skb, 2); 2472 } else 2473 #endif /* CONFIG_PPP_FILTER */ 2474 ppp->last_recv = jiffies; 2475 2476 if ((ppp->dev->flags & IFF_UP) == 0 || 2477 ppp->npmode[npi] != NPMODE_PASS) { 2478 kfree_skb(skb); 2479 } else { 2480 /* chop off protocol */ 2481 skb_pull_rcsum(skb, 2); 2482 skb->dev = ppp->dev; 2483 skb->protocol = htons(npindex_to_ethertype[npi]); 2484 skb_reset_mac_header(skb); 2485 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, 2486 dev_net(ppp->dev))); 2487 netif_rx(skb); 2488 } 2489 } 2490 return; 2491 2492 err: 2493 kfree_skb(skb); 2494 ppp_receive_error(ppp); 2495 } 2496 2497 static struct sk_buff * 2498 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb) 2499 { 2500 int proto = PPP_PROTO(skb); 2501 struct sk_buff *ns; 2502 int len; 2503 2504 /* Until we fix all the decompressor's need to make sure 2505 * data portion is linear. 2506 */ 2507 if (!pskb_may_pull(skb, skb->len)) 2508 goto err; 2509 2510 if (proto == PPP_COMP) { 2511 int obuff_size; 2512 2513 switch(ppp->rcomp->compress_proto) { 2514 case CI_MPPE: 2515 obuff_size = ppp->mru + PPP_HDRLEN + 1; 2516 break; 2517 default: 2518 obuff_size = ppp->mru + PPP_HDRLEN; 2519 break; 2520 } 2521 2522 ns = dev_alloc_skb(obuff_size); 2523 if (!ns) { 2524 netdev_err(ppp->dev, "ppp_decompress_frame: " 2525 "no memory\n"); 2526 goto err; 2527 } 2528 /* the decompressor still expects the A/C bytes in the hdr */ 2529 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2, 2530 skb->len + 2, ns->data, obuff_size); 2531 if (len < 0) { 2532 /* Pass the compressed frame to pppd as an 2533 error indication. */ 2534 if (len == DECOMP_FATALERROR) 2535 ppp->rstate |= SC_DC_FERROR; 2536 kfree_skb(ns); 2537 goto err; 2538 } 2539 2540 consume_skb(skb); 2541 skb = ns; 2542 skb_put(skb, len); 2543 skb_pull(skb, 2); /* pull off the A/C bytes */ 2544 2545 /* Don't call __ppp_decompress_proto() here, but instead rely on 2546 * corresponding algo (mppe/bsd/deflate) to decompress it. 2547 */ 2548 } else { 2549 /* Uncompressed frame - pass to decompressor so it 2550 can update its dictionary if necessary. */ 2551 if (ppp->rcomp->incomp) 2552 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2, 2553 skb->len + 2); 2554 } 2555 2556 return skb; 2557 2558 err: 2559 ppp->rstate |= SC_DC_ERROR; 2560 ppp_receive_error(ppp); 2561 return skb; 2562 } 2563 2564 #ifdef CONFIG_PPP_MULTILINK 2565 /* 2566 * Receive a multilink frame. 2567 * We put it on the reconstruction queue and then pull off 2568 * as many completed frames as we can. 2569 */ 2570 static void 2571 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2572 { 2573 u32 mask, seq; 2574 struct channel *ch; 2575 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 2576 2577 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0) 2578 goto err; /* no good, throw it away */ 2579 2580 /* Decode sequence number and begin/end bits */ 2581 if (ppp->flags & SC_MP_SHORTSEQ) { 2582 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3]; 2583 mask = 0xfff; 2584 } else { 2585 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5]; 2586 mask = 0xffffff; 2587 } 2588 PPP_MP_CB(skb)->BEbits = skb->data[2]; 2589 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */ 2590 2591 /* 2592 * Do protocol ID decompression on the first fragment of each packet. 2593 * We have to do that here, because ppp_receive_nonmp_frame() expects 2594 * decompressed protocol field. 2595 */ 2596 if (PPP_MP_CB(skb)->BEbits & B) 2597 __ppp_decompress_proto(skb); 2598 2599 /* 2600 * Expand sequence number to 32 bits, making it as close 2601 * as possible to ppp->minseq. 2602 */ 2603 seq |= ppp->minseq & ~mask; 2604 if ((int)(ppp->minseq - seq) > (int)(mask >> 1)) 2605 seq += mask + 1; 2606 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1)) 2607 seq -= mask + 1; /* should never happen */ 2608 PPP_MP_CB(skb)->sequence = seq; 2609 pch->lastseq = seq; 2610 2611 /* 2612 * If this packet comes before the next one we were expecting, 2613 * drop it. 2614 */ 2615 if (seq_before(seq, ppp->nextseq)) { 2616 kfree_skb(skb); 2617 ++ppp->dev->stats.rx_dropped; 2618 ppp_receive_error(ppp); 2619 return; 2620 } 2621 2622 /* 2623 * Reevaluate minseq, the minimum over all channels of the 2624 * last sequence number received on each channel. Because of 2625 * the increasing sequence number rule, we know that any fragment 2626 * before `minseq' which hasn't arrived is never going to arrive. 2627 * The list of channels can't change because we have the receive 2628 * side of the ppp unit locked. 2629 */ 2630 list_for_each_entry(ch, &ppp->channels, clist) { 2631 if (seq_before(ch->lastseq, seq)) 2632 seq = ch->lastseq; 2633 } 2634 if (seq_before(ppp->minseq, seq)) 2635 ppp->minseq = seq; 2636 2637 /* Put the fragment on the reconstruction queue */ 2638 ppp_mp_insert(ppp, skb); 2639 2640 /* If the queue is getting long, don't wait any longer for packets 2641 before the start of the queue. */ 2642 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) { 2643 struct sk_buff *mskb = skb_peek(&ppp->mrq); 2644 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence)) 2645 ppp->minseq = PPP_MP_CB(mskb)->sequence; 2646 } 2647 2648 /* Pull completed packets off the queue and receive them. */ 2649 while ((skb = ppp_mp_reconstruct(ppp))) { 2650 if (pskb_may_pull(skb, 2)) 2651 ppp_receive_nonmp_frame(ppp, skb); 2652 else { 2653 ++ppp->dev->stats.rx_length_errors; 2654 kfree_skb(skb); 2655 ppp_receive_error(ppp); 2656 } 2657 } 2658 2659 return; 2660 2661 err: 2662 kfree_skb(skb); 2663 ppp_receive_error(ppp); 2664 } 2665 2666 /* 2667 * Insert a fragment on the MP reconstruction queue. 2668 * The queue is ordered by increasing sequence number. 2669 */ 2670 static void 2671 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb) 2672 { 2673 struct sk_buff *p; 2674 struct sk_buff_head *list = &ppp->mrq; 2675 u32 seq = PPP_MP_CB(skb)->sequence; 2676 2677 /* N.B. we don't need to lock the list lock because we have the 2678 ppp unit receive-side lock. */ 2679 skb_queue_walk(list, p) { 2680 if (seq_before(seq, PPP_MP_CB(p)->sequence)) 2681 break; 2682 } 2683 __skb_queue_before(list, p, skb); 2684 } 2685 2686 /* 2687 * Reconstruct a packet from the MP fragment queue. 2688 * We go through increasing sequence numbers until we find a 2689 * complete packet, or we get to the sequence number for a fragment 2690 * which hasn't arrived but might still do so. 2691 */ 2692 static struct sk_buff * 2693 ppp_mp_reconstruct(struct ppp *ppp) 2694 { 2695 u32 seq = ppp->nextseq; 2696 u32 minseq = ppp->minseq; 2697 struct sk_buff_head *list = &ppp->mrq; 2698 struct sk_buff *p, *tmp; 2699 struct sk_buff *head, *tail; 2700 struct sk_buff *skb = NULL; 2701 int lost = 0, len = 0; 2702 2703 if (ppp->mrru == 0) /* do nothing until mrru is set */ 2704 return NULL; 2705 head = __skb_peek(list); 2706 tail = NULL; 2707 skb_queue_walk_safe(list, p, tmp) { 2708 again: 2709 if (seq_before(PPP_MP_CB(p)->sequence, seq)) { 2710 /* this can't happen, anyway ignore the skb */ 2711 netdev_err(ppp->dev, "ppp_mp_reconstruct bad " 2712 "seq %u < %u\n", 2713 PPP_MP_CB(p)->sequence, seq); 2714 __skb_unlink(p, list); 2715 kfree_skb(p); 2716 continue; 2717 } 2718 if (PPP_MP_CB(p)->sequence != seq) { 2719 u32 oldseq; 2720 /* Fragment `seq' is missing. If it is after 2721 minseq, it might arrive later, so stop here. */ 2722 if (seq_after(seq, minseq)) 2723 break; 2724 /* Fragment `seq' is lost, keep going. */ 2725 lost = 1; 2726 oldseq = seq; 2727 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)? 2728 minseq + 1: PPP_MP_CB(p)->sequence; 2729 2730 if (ppp->debug & 1) 2731 netdev_printk(KERN_DEBUG, ppp->dev, 2732 "lost frag %u..%u\n", 2733 oldseq, seq-1); 2734 2735 goto again; 2736 } 2737 2738 /* 2739 * At this point we know that all the fragments from 2740 * ppp->nextseq to seq are either present or lost. 2741 * Also, there are no complete packets in the queue 2742 * that have no missing fragments and end before this 2743 * fragment. 2744 */ 2745 2746 /* B bit set indicates this fragment starts a packet */ 2747 if (PPP_MP_CB(p)->BEbits & B) { 2748 head = p; 2749 lost = 0; 2750 len = 0; 2751 } 2752 2753 len += p->len; 2754 2755 /* Got a complete packet yet? */ 2756 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) && 2757 (PPP_MP_CB(head)->BEbits & B)) { 2758 if (len > ppp->mrru + 2) { 2759 ++ppp->dev->stats.rx_length_errors; 2760 netdev_printk(KERN_DEBUG, ppp->dev, 2761 "PPP: reconstructed packet" 2762 " is too long (%d)\n", len); 2763 } else { 2764 tail = p; 2765 break; 2766 } 2767 ppp->nextseq = seq + 1; 2768 } 2769 2770 /* 2771 * If this is the ending fragment of a packet, 2772 * and we haven't found a complete valid packet yet, 2773 * we can discard up to and including this fragment. 2774 */ 2775 if (PPP_MP_CB(p)->BEbits & E) { 2776 struct sk_buff *tmp2; 2777 2778 skb_queue_reverse_walk_from_safe(list, p, tmp2) { 2779 if (ppp->debug & 1) 2780 netdev_printk(KERN_DEBUG, ppp->dev, 2781 "discarding frag %u\n", 2782 PPP_MP_CB(p)->sequence); 2783 __skb_unlink(p, list); 2784 kfree_skb(p); 2785 } 2786 head = skb_peek(list); 2787 if (!head) 2788 break; 2789 } 2790 ++seq; 2791 } 2792 2793 /* If we have a complete packet, copy it all into one skb. */ 2794 if (tail != NULL) { 2795 /* If we have discarded any fragments, 2796 signal a receive error. */ 2797 if (PPP_MP_CB(head)->sequence != ppp->nextseq) { 2798 skb_queue_walk_safe(list, p, tmp) { 2799 if (p == head) 2800 break; 2801 if (ppp->debug & 1) 2802 netdev_printk(KERN_DEBUG, ppp->dev, 2803 "discarding frag %u\n", 2804 PPP_MP_CB(p)->sequence); 2805 __skb_unlink(p, list); 2806 kfree_skb(p); 2807 } 2808 2809 if (ppp->debug & 1) 2810 netdev_printk(KERN_DEBUG, ppp->dev, 2811 " missed pkts %u..%u\n", 2812 ppp->nextseq, 2813 PPP_MP_CB(head)->sequence-1); 2814 ++ppp->dev->stats.rx_dropped; 2815 ppp_receive_error(ppp); 2816 } 2817 2818 skb = head; 2819 if (head != tail) { 2820 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list; 2821 p = skb_queue_next(list, head); 2822 __skb_unlink(skb, list); 2823 skb_queue_walk_from_safe(list, p, tmp) { 2824 __skb_unlink(p, list); 2825 *fragpp = p; 2826 p->next = NULL; 2827 fragpp = &p->next; 2828 2829 skb->len += p->len; 2830 skb->data_len += p->len; 2831 skb->truesize += p->truesize; 2832 2833 if (p == tail) 2834 break; 2835 } 2836 } else { 2837 __skb_unlink(skb, list); 2838 } 2839 2840 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1; 2841 } 2842 2843 return skb; 2844 } 2845 #endif /* CONFIG_PPP_MULTILINK */ 2846 2847 /* 2848 * Channel interface. 2849 */ 2850 2851 /* Create a new, unattached ppp channel. */ 2852 int ppp_register_channel(struct ppp_channel *chan) 2853 { 2854 return ppp_register_net_channel(current->nsproxy->net_ns, chan); 2855 } 2856 2857 /* Create a new, unattached ppp channel for specified net. */ 2858 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan) 2859 { 2860 struct channel *pch; 2861 struct ppp_net *pn; 2862 2863 pch = kzalloc(sizeof(struct channel), GFP_KERNEL); 2864 if (!pch) 2865 return -ENOMEM; 2866 2867 pn = ppp_pernet(net); 2868 2869 pch->ppp = NULL; 2870 pch->chan = chan; 2871 pch->chan_net = get_net(net); 2872 chan->ppp = pch; 2873 init_ppp_file(&pch->file, CHANNEL); 2874 pch->file.hdrlen = chan->hdrlen; 2875 #ifdef CONFIG_PPP_MULTILINK 2876 pch->lastseq = -1; 2877 #endif /* CONFIG_PPP_MULTILINK */ 2878 init_rwsem(&pch->chan_sem); 2879 spin_lock_init(&pch->downl); 2880 rwlock_init(&pch->upl); 2881 2882 spin_lock_bh(&pn->all_channels_lock); 2883 pch->file.index = ++pn->last_channel_index; 2884 list_add(&pch->list, &pn->new_channels); 2885 atomic_inc(&channel_count); 2886 spin_unlock_bh(&pn->all_channels_lock); 2887 2888 return 0; 2889 } 2890 2891 /* 2892 * Return the index of a channel. 2893 */ 2894 int ppp_channel_index(struct ppp_channel *chan) 2895 { 2896 struct channel *pch = chan->ppp; 2897 2898 if (pch) 2899 return pch->file.index; 2900 return -1; 2901 } 2902 2903 /* 2904 * Return the PPP unit number to which a channel is connected. 2905 */ 2906 int ppp_unit_number(struct ppp_channel *chan) 2907 { 2908 struct channel *pch = chan->ppp; 2909 int unit = -1; 2910 2911 if (pch) { 2912 read_lock_bh(&pch->upl); 2913 if (pch->ppp) 2914 unit = pch->ppp->file.index; 2915 read_unlock_bh(&pch->upl); 2916 } 2917 return unit; 2918 } 2919 2920 /* 2921 * Return the PPP device interface name of a channel. 2922 */ 2923 char *ppp_dev_name(struct ppp_channel *chan) 2924 { 2925 struct channel *pch = chan->ppp; 2926 char *name = NULL; 2927 2928 if (pch) { 2929 read_lock_bh(&pch->upl); 2930 if (pch->ppp && pch->ppp->dev) 2931 name = pch->ppp->dev->name; 2932 read_unlock_bh(&pch->upl); 2933 } 2934 return name; 2935 } 2936 2937 2938 /* 2939 * Disconnect a channel from the generic layer. 2940 * This must be called in process context. 2941 */ 2942 void 2943 ppp_unregister_channel(struct ppp_channel *chan) 2944 { 2945 struct channel *pch = chan->ppp; 2946 struct ppp_net *pn; 2947 2948 if (!pch) 2949 return; /* should never happen */ 2950 2951 chan->ppp = NULL; 2952 2953 /* 2954 * This ensures that we have returned from any calls into the 2955 * the channel's start_xmit or ioctl routine before we proceed. 2956 */ 2957 down_write(&pch->chan_sem); 2958 spin_lock_bh(&pch->downl); 2959 pch->chan = NULL; 2960 spin_unlock_bh(&pch->downl); 2961 up_write(&pch->chan_sem); 2962 ppp_disconnect_channel(pch); 2963 2964 pn = ppp_pernet(pch->chan_net); 2965 spin_lock_bh(&pn->all_channels_lock); 2966 list_del(&pch->list); 2967 spin_unlock_bh(&pn->all_channels_lock); 2968 2969 ppp_unbridge_channels(pch); 2970 2971 pch->file.dead = 1; 2972 wake_up_interruptible(&pch->file.rwait); 2973 2974 if (refcount_dec_and_test(&pch->file.refcnt)) 2975 ppp_destroy_channel(pch); 2976 } 2977 2978 /* 2979 * Callback from a channel when it can accept more to transmit. 2980 * This should be called at BH/softirq level, not interrupt level. 2981 */ 2982 void 2983 ppp_output_wakeup(struct ppp_channel *chan) 2984 { 2985 struct channel *pch = chan->ppp; 2986 2987 if (!pch) 2988 return; 2989 ppp_channel_push(pch); 2990 } 2991 2992 /* 2993 * Compression control. 2994 */ 2995 2996 /* Process the PPPIOCSCOMPRESS ioctl. */ 2997 static int 2998 ppp_set_compress(struct ppp *ppp, struct ppp_option_data *data) 2999 { 3000 int err = -EFAULT; 3001 struct compressor *cp, *ocomp; 3002 void *state, *ostate; 3003 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH]; 3004 3005 if (data->length > CCP_MAX_OPTION_LENGTH) 3006 goto out; 3007 if (copy_from_user(ccp_option, data->ptr, data->length)) 3008 goto out; 3009 3010 err = -EINVAL; 3011 if (data->length < 2 || ccp_option[1] < 2 || ccp_option[1] > data->length) 3012 goto out; 3013 3014 cp = try_then_request_module( 3015 find_compressor(ccp_option[0]), 3016 "ppp-compress-%d", ccp_option[0]); 3017 if (!cp) 3018 goto out; 3019 3020 err = -ENOBUFS; 3021 if (data->transmit) { 3022 state = cp->comp_alloc(ccp_option, data->length); 3023 if (state) { 3024 ppp_xmit_lock(ppp); 3025 ppp->xstate &= ~SC_COMP_RUN; 3026 ocomp = ppp->xcomp; 3027 ostate = ppp->xc_state; 3028 ppp->xcomp = cp; 3029 ppp->xc_state = state; 3030 ppp_xmit_unlock(ppp); 3031 if (ostate) { 3032 ocomp->comp_free(ostate); 3033 module_put(ocomp->owner); 3034 } 3035 err = 0; 3036 } else 3037 module_put(cp->owner); 3038 3039 } else { 3040 state = cp->decomp_alloc(ccp_option, data->length); 3041 if (state) { 3042 ppp_recv_lock(ppp); 3043 ppp->rstate &= ~SC_DECOMP_RUN; 3044 ocomp = ppp->rcomp; 3045 ostate = ppp->rc_state; 3046 ppp->rcomp = cp; 3047 ppp->rc_state = state; 3048 ppp_recv_unlock(ppp); 3049 if (ostate) { 3050 ocomp->decomp_free(ostate); 3051 module_put(ocomp->owner); 3052 } 3053 err = 0; 3054 } else 3055 module_put(cp->owner); 3056 } 3057 3058 out: 3059 return err; 3060 } 3061 3062 /* 3063 * Look at a CCP packet and update our state accordingly. 3064 * We assume the caller has the xmit or recv path locked. 3065 */ 3066 static void 3067 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound) 3068 { 3069 unsigned char *dp; 3070 int len; 3071 3072 if (!pskb_may_pull(skb, CCP_HDRLEN + 2)) 3073 return; /* no header */ 3074 dp = skb->data + 2; 3075 3076 switch (CCP_CODE(dp)) { 3077 case CCP_CONFREQ: 3078 3079 /* A ConfReq starts negotiation of compression 3080 * in one direction of transmission, 3081 * and hence brings it down...but which way? 3082 * 3083 * Remember: 3084 * A ConfReq indicates what the sender would like to receive 3085 */ 3086 if(inbound) 3087 /* He is proposing what I should send */ 3088 ppp->xstate &= ~SC_COMP_RUN; 3089 else 3090 /* I am proposing to what he should send */ 3091 ppp->rstate &= ~SC_DECOMP_RUN; 3092 3093 break; 3094 3095 case CCP_TERMREQ: 3096 case CCP_TERMACK: 3097 /* 3098 * CCP is going down, both directions of transmission 3099 */ 3100 ppp->rstate &= ~SC_DECOMP_RUN; 3101 ppp->xstate &= ~SC_COMP_RUN; 3102 break; 3103 3104 case CCP_CONFACK: 3105 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN) 3106 break; 3107 len = CCP_LENGTH(dp); 3108 if (!pskb_may_pull(skb, len + 2)) 3109 return; /* too short */ 3110 dp += CCP_HDRLEN; 3111 len -= CCP_HDRLEN; 3112 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp)) 3113 break; 3114 if (inbound) { 3115 /* we will start receiving compressed packets */ 3116 if (!ppp->rc_state) 3117 break; 3118 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len, 3119 ppp->file.index, 0, ppp->mru, ppp->debug)) { 3120 ppp->rstate |= SC_DECOMP_RUN; 3121 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR); 3122 } 3123 } else { 3124 /* we will soon start sending compressed packets */ 3125 if (!ppp->xc_state) 3126 break; 3127 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len, 3128 ppp->file.index, 0, ppp->debug)) 3129 ppp->xstate |= SC_COMP_RUN; 3130 } 3131 break; 3132 3133 case CCP_RESETACK: 3134 /* reset the [de]compressor */ 3135 if ((ppp->flags & SC_CCP_UP) == 0) 3136 break; 3137 if (inbound) { 3138 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) { 3139 ppp->rcomp->decomp_reset(ppp->rc_state); 3140 ppp->rstate &= ~SC_DC_ERROR; 3141 } 3142 } else { 3143 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN)) 3144 ppp->xcomp->comp_reset(ppp->xc_state); 3145 } 3146 break; 3147 } 3148 } 3149 3150 /* Free up compression resources. */ 3151 static void 3152 ppp_ccp_closed(struct ppp *ppp) 3153 { 3154 void *xstate, *rstate; 3155 struct compressor *xcomp, *rcomp; 3156 3157 ppp_lock(ppp); 3158 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP); 3159 ppp->xstate = 0; 3160 xcomp = ppp->xcomp; 3161 xstate = ppp->xc_state; 3162 ppp->xc_state = NULL; 3163 ppp->rstate = 0; 3164 rcomp = ppp->rcomp; 3165 rstate = ppp->rc_state; 3166 ppp->rc_state = NULL; 3167 ppp_unlock(ppp); 3168 3169 if (xstate) { 3170 xcomp->comp_free(xstate); 3171 module_put(xcomp->owner); 3172 } 3173 if (rstate) { 3174 rcomp->decomp_free(rstate); 3175 module_put(rcomp->owner); 3176 } 3177 } 3178 3179 /* List of compressors. */ 3180 static LIST_HEAD(compressor_list); 3181 static DEFINE_SPINLOCK(compressor_list_lock); 3182 3183 struct compressor_entry { 3184 struct list_head list; 3185 struct compressor *comp; 3186 }; 3187 3188 static struct compressor_entry * 3189 find_comp_entry(int proto) 3190 { 3191 struct compressor_entry *ce; 3192 3193 list_for_each_entry(ce, &compressor_list, list) { 3194 if (ce->comp->compress_proto == proto) 3195 return ce; 3196 } 3197 return NULL; 3198 } 3199 3200 /* Register a compressor */ 3201 int 3202 ppp_register_compressor(struct compressor *cp) 3203 { 3204 struct compressor_entry *ce; 3205 int ret; 3206 spin_lock(&compressor_list_lock); 3207 ret = -EEXIST; 3208 if (find_comp_entry(cp->compress_proto)) 3209 goto out; 3210 ret = -ENOMEM; 3211 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC); 3212 if (!ce) 3213 goto out; 3214 ret = 0; 3215 ce->comp = cp; 3216 list_add(&ce->list, &compressor_list); 3217 out: 3218 spin_unlock(&compressor_list_lock); 3219 return ret; 3220 } 3221 3222 /* Unregister a compressor */ 3223 void 3224 ppp_unregister_compressor(struct compressor *cp) 3225 { 3226 struct compressor_entry *ce; 3227 3228 spin_lock(&compressor_list_lock); 3229 ce = find_comp_entry(cp->compress_proto); 3230 if (ce && ce->comp == cp) { 3231 list_del(&ce->list); 3232 kfree(ce); 3233 } 3234 spin_unlock(&compressor_list_lock); 3235 } 3236 3237 /* Find a compressor. */ 3238 static struct compressor * 3239 find_compressor(int type) 3240 { 3241 struct compressor_entry *ce; 3242 struct compressor *cp = NULL; 3243 3244 spin_lock(&compressor_list_lock); 3245 ce = find_comp_entry(type); 3246 if (ce) { 3247 cp = ce->comp; 3248 if (!try_module_get(cp->owner)) 3249 cp = NULL; 3250 } 3251 spin_unlock(&compressor_list_lock); 3252 return cp; 3253 } 3254 3255 /* 3256 * Miscelleneous stuff. 3257 */ 3258 3259 static void 3260 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st) 3261 { 3262 struct slcompress *vj = ppp->vj; 3263 3264 memset(st, 0, sizeof(*st)); 3265 st->p.ppp_ipackets = ppp->stats64.rx_packets; 3266 st->p.ppp_ierrors = ppp->dev->stats.rx_errors; 3267 st->p.ppp_ibytes = ppp->stats64.rx_bytes; 3268 st->p.ppp_opackets = ppp->stats64.tx_packets; 3269 st->p.ppp_oerrors = ppp->dev->stats.tx_errors; 3270 st->p.ppp_obytes = ppp->stats64.tx_bytes; 3271 if (!vj) 3272 return; 3273 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed; 3274 st->vj.vjs_compressed = vj->sls_o_compressed; 3275 st->vj.vjs_searches = vj->sls_o_searches; 3276 st->vj.vjs_misses = vj->sls_o_misses; 3277 st->vj.vjs_errorin = vj->sls_i_error; 3278 st->vj.vjs_tossed = vj->sls_i_tossed; 3279 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed; 3280 st->vj.vjs_compressedin = vj->sls_i_compressed; 3281 } 3282 3283 /* 3284 * Stuff for handling the lists of ppp units and channels 3285 * and for initialization. 3286 */ 3287 3288 /* 3289 * Create a new ppp interface unit. Fails if it can't allocate memory 3290 * or if there is already a unit with the requested number. 3291 * unit == -1 means allocate a new number. 3292 */ 3293 static int ppp_create_interface(struct net *net, struct file *file, int *unit) 3294 { 3295 struct ppp_config conf = { 3296 .file = file, 3297 .unit = *unit, 3298 .ifname_is_set = false, 3299 }; 3300 struct net_device *dev; 3301 struct ppp *ppp; 3302 int err; 3303 3304 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup); 3305 if (!dev) { 3306 err = -ENOMEM; 3307 goto err; 3308 } 3309 dev_net_set(dev, net); 3310 dev->rtnl_link_ops = &ppp_link_ops; 3311 3312 rtnl_lock(); 3313 3314 err = ppp_dev_configure(net, dev, &conf); 3315 if (err < 0) 3316 goto err_dev; 3317 ppp = netdev_priv(dev); 3318 *unit = ppp->file.index; 3319 3320 rtnl_unlock(); 3321 3322 return 0; 3323 3324 err_dev: 3325 rtnl_unlock(); 3326 free_netdev(dev); 3327 err: 3328 return err; 3329 } 3330 3331 /* 3332 * Initialize a ppp_file structure. 3333 */ 3334 static void 3335 init_ppp_file(struct ppp_file *pf, int kind) 3336 { 3337 pf->kind = kind; 3338 skb_queue_head_init(&pf->xq); 3339 skb_queue_head_init(&pf->rq); 3340 refcount_set(&pf->refcnt, 1); 3341 init_waitqueue_head(&pf->rwait); 3342 } 3343 3344 /* 3345 * Free the memory used by a ppp unit. This is only called once 3346 * there are no channels connected to the unit and no file structs 3347 * that reference the unit. 3348 */ 3349 static void ppp_destroy_interface(struct ppp *ppp) 3350 { 3351 atomic_dec(&ppp_unit_count); 3352 3353 if (!ppp->file.dead || ppp->n_channels) { 3354 /* "can't happen" */ 3355 netdev_err(ppp->dev, "ppp: destroying ppp struct %p " 3356 "but dead=%d n_channels=%d !\n", 3357 ppp, ppp->file.dead, ppp->n_channels); 3358 return; 3359 } 3360 3361 ppp_ccp_closed(ppp); 3362 if (ppp->vj) { 3363 slhc_free(ppp->vj); 3364 ppp->vj = NULL; 3365 } 3366 skb_queue_purge(&ppp->file.xq); 3367 skb_queue_purge(&ppp->file.rq); 3368 #ifdef CONFIG_PPP_MULTILINK 3369 skb_queue_purge(&ppp->mrq); 3370 #endif /* CONFIG_PPP_MULTILINK */ 3371 #ifdef CONFIG_PPP_FILTER 3372 if (ppp->pass_filter) { 3373 bpf_prog_destroy(ppp->pass_filter); 3374 ppp->pass_filter = NULL; 3375 } 3376 3377 if (ppp->active_filter) { 3378 bpf_prog_destroy(ppp->active_filter); 3379 ppp->active_filter = NULL; 3380 } 3381 #endif /* CONFIG_PPP_FILTER */ 3382 3383 kfree_skb(ppp->xmit_pending); 3384 free_percpu(ppp->xmit_recursion); 3385 3386 free_netdev(ppp->dev); 3387 } 3388 3389 /* 3390 * Locate an existing ppp unit. 3391 * The caller should have locked the all_ppp_mutex. 3392 */ 3393 static struct ppp * 3394 ppp_find_unit(struct ppp_net *pn, int unit) 3395 { 3396 return unit_find(&pn->units_idr, unit); 3397 } 3398 3399 /* 3400 * Locate an existing ppp channel. 3401 * The caller should have locked the all_channels_lock. 3402 * First we look in the new_channels list, then in the 3403 * all_channels list. If found in the new_channels list, 3404 * we move it to the all_channels list. This is for speed 3405 * when we have a lot of channels in use. 3406 */ 3407 static struct channel * 3408 ppp_find_channel(struct ppp_net *pn, int unit) 3409 { 3410 struct channel *pch; 3411 3412 list_for_each_entry(pch, &pn->new_channels, list) { 3413 if (pch->file.index == unit) { 3414 list_move(&pch->list, &pn->all_channels); 3415 return pch; 3416 } 3417 } 3418 3419 list_for_each_entry(pch, &pn->all_channels, list) { 3420 if (pch->file.index == unit) 3421 return pch; 3422 } 3423 3424 return NULL; 3425 } 3426 3427 /* 3428 * Connect a PPP channel to a PPP interface unit. 3429 */ 3430 static int 3431 ppp_connect_channel(struct channel *pch, int unit) 3432 { 3433 struct ppp *ppp; 3434 struct ppp_net *pn; 3435 int ret = -ENXIO; 3436 int hdrlen; 3437 3438 pn = ppp_pernet(pch->chan_net); 3439 3440 mutex_lock(&pn->all_ppp_mutex); 3441 ppp = ppp_find_unit(pn, unit); 3442 if (!ppp) 3443 goto out; 3444 write_lock_bh(&pch->upl); 3445 ret = -EINVAL; 3446 if (pch->ppp || 3447 rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl))) 3448 goto outl; 3449 3450 ppp_lock(ppp); 3451 spin_lock_bh(&pch->downl); 3452 if (!pch->chan) { 3453 /* Don't connect unregistered channels */ 3454 spin_unlock_bh(&pch->downl); 3455 ppp_unlock(ppp); 3456 ret = -ENOTCONN; 3457 goto outl; 3458 } 3459 spin_unlock_bh(&pch->downl); 3460 if (pch->file.hdrlen > ppp->file.hdrlen) 3461 ppp->file.hdrlen = pch->file.hdrlen; 3462 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */ 3463 if (hdrlen > ppp->dev->hard_header_len) 3464 ppp->dev->hard_header_len = hdrlen; 3465 list_add_tail(&pch->clist, &ppp->channels); 3466 ++ppp->n_channels; 3467 pch->ppp = ppp; 3468 refcount_inc(&ppp->file.refcnt); 3469 ppp_unlock(ppp); 3470 ret = 0; 3471 3472 outl: 3473 write_unlock_bh(&pch->upl); 3474 out: 3475 mutex_unlock(&pn->all_ppp_mutex); 3476 return ret; 3477 } 3478 3479 /* 3480 * Disconnect a channel from its ppp unit. 3481 */ 3482 static int 3483 ppp_disconnect_channel(struct channel *pch) 3484 { 3485 struct ppp *ppp; 3486 int err = -EINVAL; 3487 3488 write_lock_bh(&pch->upl); 3489 ppp = pch->ppp; 3490 pch->ppp = NULL; 3491 write_unlock_bh(&pch->upl); 3492 if (ppp) { 3493 /* remove it from the ppp unit's list */ 3494 ppp_lock(ppp); 3495 list_del(&pch->clist); 3496 if (--ppp->n_channels == 0) 3497 wake_up_interruptible(&ppp->file.rwait); 3498 ppp_unlock(ppp); 3499 if (refcount_dec_and_test(&ppp->file.refcnt)) 3500 ppp_destroy_interface(ppp); 3501 err = 0; 3502 } 3503 return err; 3504 } 3505 3506 /* 3507 * Free up the resources used by a ppp channel. 3508 */ 3509 static void ppp_destroy_channel(struct channel *pch) 3510 { 3511 put_net(pch->chan_net); 3512 pch->chan_net = NULL; 3513 3514 atomic_dec(&channel_count); 3515 3516 if (!pch->file.dead) { 3517 /* "can't happen" */ 3518 pr_err("ppp: destroying undead channel %p !\n", pch); 3519 return; 3520 } 3521 skb_queue_purge(&pch->file.xq); 3522 skb_queue_purge(&pch->file.rq); 3523 kfree(pch); 3524 } 3525 3526 static void __exit ppp_cleanup(void) 3527 { 3528 /* should never happen */ 3529 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count)) 3530 pr_err("PPP: removing module but units remain!\n"); 3531 rtnl_link_unregister(&ppp_link_ops); 3532 unregister_chrdev(PPP_MAJOR, "ppp"); 3533 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0)); 3534 class_destroy(ppp_class); 3535 unregister_pernet_device(&ppp_net_ops); 3536 } 3537 3538 /* 3539 * Units handling. Caller must protect concurrent access 3540 * by holding all_ppp_mutex 3541 */ 3542 3543 /* associate pointer with specified number */ 3544 static int unit_set(struct idr *p, void *ptr, int n) 3545 { 3546 int unit; 3547 3548 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL); 3549 if (unit == -ENOSPC) 3550 unit = -EINVAL; 3551 return unit; 3552 } 3553 3554 /* get new free unit number and associate pointer with it */ 3555 static int unit_get(struct idr *p, void *ptr) 3556 { 3557 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL); 3558 } 3559 3560 /* put unit number back to a pool */ 3561 static void unit_put(struct idr *p, int n) 3562 { 3563 idr_remove(p, n); 3564 } 3565 3566 /* get pointer associated with the number */ 3567 static void *unit_find(struct idr *p, int n) 3568 { 3569 return idr_find(p, n); 3570 } 3571 3572 /* Module/initialization stuff */ 3573 3574 module_init(ppp_init); 3575 module_exit(ppp_cleanup); 3576 3577 EXPORT_SYMBOL(ppp_register_net_channel); 3578 EXPORT_SYMBOL(ppp_register_channel); 3579 EXPORT_SYMBOL(ppp_unregister_channel); 3580 EXPORT_SYMBOL(ppp_channel_index); 3581 EXPORT_SYMBOL(ppp_unit_number); 3582 EXPORT_SYMBOL(ppp_dev_name); 3583 EXPORT_SYMBOL(ppp_input); 3584 EXPORT_SYMBOL(ppp_input_error); 3585 EXPORT_SYMBOL(ppp_output_wakeup); 3586 EXPORT_SYMBOL(ppp_register_compressor); 3587 EXPORT_SYMBOL(ppp_unregister_compressor); 3588 MODULE_LICENSE("GPL"); 3589 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0); 3590 MODULE_ALIAS_RTNL_LINK("ppp"); 3591 MODULE_ALIAS("devname:ppp"); 3592