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, int min); 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, 0); 1159 if (ret < 0) 1160 goto err; 1161 if (!ifname_is_set) { 1162 while (1) { 1163 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ret); 1164 if (!__dev_get_by_name(ppp->ppp_net, ppp->dev->name)) 1165 break; 1166 unit_put(&pn->units_idr, ret); 1167 ret = unit_get(&pn->units_idr, ppp, ret + 1); 1168 if (ret < 0) 1169 goto err; 1170 } 1171 } 1172 } else { 1173 /* Caller asked for a specific unit number. Fail with -EEXIST 1174 * if unavailable. For backward compatibility, return -EEXIST 1175 * too if idr allocation fails; this makes pppd retry without 1176 * requesting a specific unit number. 1177 */ 1178 if (unit_find(&pn->units_idr, unit)) { 1179 ret = -EEXIST; 1180 goto err; 1181 } 1182 ret = unit_set(&pn->units_idr, ppp, unit); 1183 if (ret < 0) { 1184 /* Rewrite error for backward compatibility */ 1185 ret = -EEXIST; 1186 goto err; 1187 } 1188 } 1189 ppp->file.index = ret; 1190 1191 if (!ifname_is_set) 1192 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ppp->file.index); 1193 1194 mutex_unlock(&pn->all_ppp_mutex); 1195 1196 ret = register_netdevice(ppp->dev); 1197 if (ret < 0) 1198 goto err_unit; 1199 1200 atomic_inc(&ppp_unit_count); 1201 1202 return 0; 1203 1204 err_unit: 1205 mutex_lock(&pn->all_ppp_mutex); 1206 unit_put(&pn->units_idr, ppp->file.index); 1207 err: 1208 mutex_unlock(&pn->all_ppp_mutex); 1209 1210 return ret; 1211 } 1212 1213 static int ppp_dev_configure(struct net *src_net, struct net_device *dev, 1214 const struct ppp_config *conf) 1215 { 1216 struct ppp *ppp = netdev_priv(dev); 1217 int indx; 1218 int err; 1219 int cpu; 1220 1221 ppp->dev = dev; 1222 ppp->ppp_net = src_net; 1223 ppp->mru = PPP_MRU; 1224 ppp->owner = conf->file; 1225 1226 init_ppp_file(&ppp->file, INTERFACE); 1227 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */ 1228 1229 for (indx = 0; indx < NUM_NP; ++indx) 1230 ppp->npmode[indx] = NPMODE_PASS; 1231 INIT_LIST_HEAD(&ppp->channels); 1232 spin_lock_init(&ppp->rlock); 1233 spin_lock_init(&ppp->wlock); 1234 1235 ppp->xmit_recursion = alloc_percpu(int); 1236 if (!ppp->xmit_recursion) { 1237 err = -ENOMEM; 1238 goto err1; 1239 } 1240 for_each_possible_cpu(cpu) 1241 (*per_cpu_ptr(ppp->xmit_recursion, cpu)) = 0; 1242 1243 #ifdef CONFIG_PPP_MULTILINK 1244 ppp->minseq = -1; 1245 skb_queue_head_init(&ppp->mrq); 1246 #endif /* CONFIG_PPP_MULTILINK */ 1247 #ifdef CONFIG_PPP_FILTER 1248 ppp->pass_filter = NULL; 1249 ppp->active_filter = NULL; 1250 #endif /* CONFIG_PPP_FILTER */ 1251 1252 err = ppp_unit_register(ppp, conf->unit, conf->ifname_is_set); 1253 if (err < 0) 1254 goto err2; 1255 1256 conf->file->private_data = &ppp->file; 1257 1258 return 0; 1259 err2: 1260 free_percpu(ppp->xmit_recursion); 1261 err1: 1262 return err; 1263 } 1264 1265 static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = { 1266 [IFLA_PPP_DEV_FD] = { .type = NLA_S32 }, 1267 }; 1268 1269 static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[], 1270 struct netlink_ext_ack *extack) 1271 { 1272 if (!data) 1273 return -EINVAL; 1274 1275 if (!data[IFLA_PPP_DEV_FD]) 1276 return -EINVAL; 1277 if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0) 1278 return -EBADF; 1279 1280 return 0; 1281 } 1282 1283 static int ppp_nl_newlink(struct net *src_net, struct net_device *dev, 1284 struct nlattr *tb[], struct nlattr *data[], 1285 struct netlink_ext_ack *extack) 1286 { 1287 struct ppp_config conf = { 1288 .unit = -1, 1289 .ifname_is_set = true, 1290 }; 1291 struct file *file; 1292 int err; 1293 1294 file = fget(nla_get_s32(data[IFLA_PPP_DEV_FD])); 1295 if (!file) 1296 return -EBADF; 1297 1298 /* rtnl_lock is already held here, but ppp_create_interface() locks 1299 * ppp_mutex before holding rtnl_lock. Using mutex_trylock() avoids 1300 * possible deadlock due to lock order inversion, at the cost of 1301 * pushing the problem back to userspace. 1302 */ 1303 if (!mutex_trylock(&ppp_mutex)) { 1304 err = -EBUSY; 1305 goto out; 1306 } 1307 1308 if (file->f_op != &ppp_device_fops || file->private_data) { 1309 err = -EBADF; 1310 goto out_unlock; 1311 } 1312 1313 conf.file = file; 1314 1315 /* Don't use device name generated by the rtnetlink layer when ifname 1316 * isn't specified. Let ppp_dev_configure() set the device name using 1317 * the PPP unit identifer as suffix (i.e. ppp<unit_id>). This allows 1318 * userspace to infer the device name using to the PPPIOCGUNIT ioctl. 1319 */ 1320 if (!tb[IFLA_IFNAME] || !nla_len(tb[IFLA_IFNAME]) || !*(char *)nla_data(tb[IFLA_IFNAME])) 1321 conf.ifname_is_set = false; 1322 1323 err = ppp_dev_configure(src_net, dev, &conf); 1324 1325 out_unlock: 1326 mutex_unlock(&ppp_mutex); 1327 out: 1328 fput(file); 1329 1330 return err; 1331 } 1332 1333 static void ppp_nl_dellink(struct net_device *dev, struct list_head *head) 1334 { 1335 unregister_netdevice_queue(dev, head); 1336 } 1337 1338 static size_t ppp_nl_get_size(const struct net_device *dev) 1339 { 1340 return 0; 1341 } 1342 1343 static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev) 1344 { 1345 return 0; 1346 } 1347 1348 static struct net *ppp_nl_get_link_net(const struct net_device *dev) 1349 { 1350 struct ppp *ppp = netdev_priv(dev); 1351 1352 return ppp->ppp_net; 1353 } 1354 1355 static struct rtnl_link_ops ppp_link_ops __read_mostly = { 1356 .kind = "ppp", 1357 .maxtype = IFLA_PPP_MAX, 1358 .policy = ppp_nl_policy, 1359 .priv_size = sizeof(struct ppp), 1360 .setup = ppp_setup, 1361 .validate = ppp_nl_validate, 1362 .newlink = ppp_nl_newlink, 1363 .dellink = ppp_nl_dellink, 1364 .get_size = ppp_nl_get_size, 1365 .fill_info = ppp_nl_fill_info, 1366 .get_link_net = ppp_nl_get_link_net, 1367 }; 1368 1369 #define PPP_MAJOR 108 1370 1371 /* Called at boot time if ppp is compiled into the kernel, 1372 or at module load time (from init_module) if compiled as a module. */ 1373 static int __init ppp_init(void) 1374 { 1375 int err; 1376 1377 pr_info("PPP generic driver version " PPP_VERSION "\n"); 1378 1379 err = register_pernet_device(&ppp_net_ops); 1380 if (err) { 1381 pr_err("failed to register PPP pernet device (%d)\n", err); 1382 goto out; 1383 } 1384 1385 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops); 1386 if (err) { 1387 pr_err("failed to register PPP device (%d)\n", err); 1388 goto out_net; 1389 } 1390 1391 ppp_class = class_create(THIS_MODULE, "ppp"); 1392 if (IS_ERR(ppp_class)) { 1393 err = PTR_ERR(ppp_class); 1394 goto out_chrdev; 1395 } 1396 1397 err = rtnl_link_register(&ppp_link_ops); 1398 if (err) { 1399 pr_err("failed to register rtnetlink PPP handler\n"); 1400 goto out_class; 1401 } 1402 1403 /* not a big deal if we fail here :-) */ 1404 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp"); 1405 1406 return 0; 1407 1408 out_class: 1409 class_destroy(ppp_class); 1410 out_chrdev: 1411 unregister_chrdev(PPP_MAJOR, "ppp"); 1412 out_net: 1413 unregister_pernet_device(&ppp_net_ops); 1414 out: 1415 return err; 1416 } 1417 1418 /* 1419 * Network interface unit routines. 1420 */ 1421 static netdev_tx_t 1422 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev) 1423 { 1424 struct ppp *ppp = netdev_priv(dev); 1425 int npi, proto; 1426 unsigned char *pp; 1427 1428 npi = ethertype_to_npindex(ntohs(skb->protocol)); 1429 if (npi < 0) 1430 goto outf; 1431 1432 /* Drop, accept or reject the packet */ 1433 switch (ppp->npmode[npi]) { 1434 case NPMODE_PASS: 1435 break; 1436 case NPMODE_QUEUE: 1437 /* it would be nice to have a way to tell the network 1438 system to queue this one up for later. */ 1439 goto outf; 1440 case NPMODE_DROP: 1441 case NPMODE_ERROR: 1442 goto outf; 1443 } 1444 1445 /* Put the 2-byte PPP protocol number on the front, 1446 making sure there is room for the address and control fields. */ 1447 if (skb_cow_head(skb, PPP_HDRLEN)) 1448 goto outf; 1449 1450 pp = skb_push(skb, 2); 1451 proto = npindex_to_proto[npi]; 1452 put_unaligned_be16(proto, pp); 1453 1454 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev))); 1455 ppp_xmit_process(ppp, skb); 1456 1457 return NETDEV_TX_OK; 1458 1459 outf: 1460 kfree_skb(skb); 1461 ++dev->stats.tx_dropped; 1462 return NETDEV_TX_OK; 1463 } 1464 1465 static int 1466 ppp_net_siocdevprivate(struct net_device *dev, struct ifreq *ifr, 1467 void __user *addr, int cmd) 1468 { 1469 struct ppp *ppp = netdev_priv(dev); 1470 int err = -EFAULT; 1471 struct ppp_stats stats; 1472 struct ppp_comp_stats cstats; 1473 char *vers; 1474 1475 switch (cmd) { 1476 case SIOCGPPPSTATS: 1477 ppp_get_stats(ppp, &stats); 1478 if (copy_to_user(addr, &stats, sizeof(stats))) 1479 break; 1480 err = 0; 1481 break; 1482 1483 case SIOCGPPPCSTATS: 1484 memset(&cstats, 0, sizeof(cstats)); 1485 if (ppp->xc_state) 1486 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c); 1487 if (ppp->rc_state) 1488 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d); 1489 if (copy_to_user(addr, &cstats, sizeof(cstats))) 1490 break; 1491 err = 0; 1492 break; 1493 1494 case SIOCGPPPVER: 1495 vers = PPP_VERSION; 1496 if (copy_to_user(addr, vers, strlen(vers) + 1)) 1497 break; 1498 err = 0; 1499 break; 1500 1501 default: 1502 err = -EINVAL; 1503 } 1504 1505 return err; 1506 } 1507 1508 static void 1509 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64) 1510 { 1511 struct ppp *ppp = netdev_priv(dev); 1512 1513 ppp_recv_lock(ppp); 1514 stats64->rx_packets = ppp->stats64.rx_packets; 1515 stats64->rx_bytes = ppp->stats64.rx_bytes; 1516 ppp_recv_unlock(ppp); 1517 1518 ppp_xmit_lock(ppp); 1519 stats64->tx_packets = ppp->stats64.tx_packets; 1520 stats64->tx_bytes = ppp->stats64.tx_bytes; 1521 ppp_xmit_unlock(ppp); 1522 1523 stats64->rx_errors = dev->stats.rx_errors; 1524 stats64->tx_errors = dev->stats.tx_errors; 1525 stats64->rx_dropped = dev->stats.rx_dropped; 1526 stats64->tx_dropped = dev->stats.tx_dropped; 1527 stats64->rx_length_errors = dev->stats.rx_length_errors; 1528 } 1529 1530 static int ppp_dev_init(struct net_device *dev) 1531 { 1532 struct ppp *ppp; 1533 1534 netdev_lockdep_set_classes(dev); 1535 1536 ppp = netdev_priv(dev); 1537 /* Let the netdevice take a reference on the ppp file. This ensures 1538 * that ppp_destroy_interface() won't run before the device gets 1539 * unregistered. 1540 */ 1541 refcount_inc(&ppp->file.refcnt); 1542 1543 return 0; 1544 } 1545 1546 static void ppp_dev_uninit(struct net_device *dev) 1547 { 1548 struct ppp *ppp = netdev_priv(dev); 1549 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 1550 1551 ppp_lock(ppp); 1552 ppp->closing = 1; 1553 ppp_unlock(ppp); 1554 1555 mutex_lock(&pn->all_ppp_mutex); 1556 unit_put(&pn->units_idr, ppp->file.index); 1557 mutex_unlock(&pn->all_ppp_mutex); 1558 1559 ppp->owner = NULL; 1560 1561 ppp->file.dead = 1; 1562 wake_up_interruptible(&ppp->file.rwait); 1563 } 1564 1565 static void ppp_dev_priv_destructor(struct net_device *dev) 1566 { 1567 struct ppp *ppp; 1568 1569 ppp = netdev_priv(dev); 1570 if (refcount_dec_and_test(&ppp->file.refcnt)) 1571 ppp_destroy_interface(ppp); 1572 } 1573 1574 static int ppp_fill_forward_path(struct net_device_path_ctx *ctx, 1575 struct net_device_path *path) 1576 { 1577 struct ppp *ppp = netdev_priv(ctx->dev); 1578 struct ppp_channel *chan; 1579 struct channel *pch; 1580 1581 if (ppp->flags & SC_MULTILINK) 1582 return -EOPNOTSUPP; 1583 1584 if (list_empty(&ppp->channels)) 1585 return -ENODEV; 1586 1587 pch = list_first_entry(&ppp->channels, struct channel, clist); 1588 chan = pch->chan; 1589 if (!chan->ops->fill_forward_path) 1590 return -EOPNOTSUPP; 1591 1592 return chan->ops->fill_forward_path(ctx, path, chan); 1593 } 1594 1595 static const struct net_device_ops ppp_netdev_ops = { 1596 .ndo_init = ppp_dev_init, 1597 .ndo_uninit = ppp_dev_uninit, 1598 .ndo_start_xmit = ppp_start_xmit, 1599 .ndo_siocdevprivate = ppp_net_siocdevprivate, 1600 .ndo_get_stats64 = ppp_get_stats64, 1601 .ndo_fill_forward_path = ppp_fill_forward_path, 1602 }; 1603 1604 static struct device_type ppp_type = { 1605 .name = "ppp", 1606 }; 1607 1608 static void ppp_setup(struct net_device *dev) 1609 { 1610 dev->netdev_ops = &ppp_netdev_ops; 1611 SET_NETDEV_DEVTYPE(dev, &ppp_type); 1612 1613 dev->features |= NETIF_F_LLTX; 1614 1615 dev->hard_header_len = PPP_HDRLEN; 1616 dev->mtu = PPP_MRU; 1617 dev->addr_len = 0; 1618 dev->tx_queue_len = 3; 1619 dev->type = ARPHRD_PPP; 1620 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 1621 dev->priv_destructor = ppp_dev_priv_destructor; 1622 netif_keep_dst(dev); 1623 } 1624 1625 /* 1626 * Transmit-side routines. 1627 */ 1628 1629 /* Called to do any work queued up on the transmit side that can now be done */ 1630 static void __ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb) 1631 { 1632 ppp_xmit_lock(ppp); 1633 if (!ppp->closing) { 1634 ppp_push(ppp); 1635 1636 if (skb) 1637 skb_queue_tail(&ppp->file.xq, skb); 1638 while (!ppp->xmit_pending && 1639 (skb = skb_dequeue(&ppp->file.xq))) 1640 ppp_send_frame(ppp, skb); 1641 /* If there's no work left to do, tell the core net 1642 code that we can accept some more. */ 1643 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq)) 1644 netif_wake_queue(ppp->dev); 1645 else 1646 netif_stop_queue(ppp->dev); 1647 } else { 1648 kfree_skb(skb); 1649 } 1650 ppp_xmit_unlock(ppp); 1651 } 1652 1653 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb) 1654 { 1655 local_bh_disable(); 1656 1657 if (unlikely(*this_cpu_ptr(ppp->xmit_recursion))) 1658 goto err; 1659 1660 (*this_cpu_ptr(ppp->xmit_recursion))++; 1661 __ppp_xmit_process(ppp, skb); 1662 (*this_cpu_ptr(ppp->xmit_recursion))--; 1663 1664 local_bh_enable(); 1665 1666 return; 1667 1668 err: 1669 local_bh_enable(); 1670 1671 kfree_skb(skb); 1672 1673 if (net_ratelimit()) 1674 netdev_err(ppp->dev, "recursion detected\n"); 1675 } 1676 1677 static inline struct sk_buff * 1678 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) 1679 { 1680 struct sk_buff *new_skb; 1681 int len; 1682 int new_skb_size = ppp->dev->mtu + 1683 ppp->xcomp->comp_extra + ppp->dev->hard_header_len; 1684 int compressor_skb_size = ppp->dev->mtu + 1685 ppp->xcomp->comp_extra + PPP_HDRLEN; 1686 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC); 1687 if (!new_skb) { 1688 if (net_ratelimit()) 1689 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n"); 1690 return NULL; 1691 } 1692 if (ppp->dev->hard_header_len > PPP_HDRLEN) 1693 skb_reserve(new_skb, 1694 ppp->dev->hard_header_len - PPP_HDRLEN); 1695 1696 /* compressor still expects A/C bytes in hdr */ 1697 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, 1698 new_skb->data, skb->len + 2, 1699 compressor_skb_size); 1700 if (len > 0 && (ppp->flags & SC_CCP_UP)) { 1701 consume_skb(skb); 1702 skb = new_skb; 1703 skb_put(skb, len); 1704 skb_pull(skb, 2); /* pull off A/C bytes */ 1705 } else if (len == 0) { 1706 /* didn't compress, or CCP not up yet */ 1707 consume_skb(new_skb); 1708 new_skb = skb; 1709 } else { 1710 /* 1711 * (len < 0) 1712 * MPPE requires that we do not send unencrypted 1713 * frames. The compressor will return -1 if we 1714 * should drop the frame. We cannot simply test 1715 * the compress_proto because MPPE and MPPC share 1716 * the same number. 1717 */ 1718 if (net_ratelimit()) 1719 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n"); 1720 kfree_skb(skb); 1721 consume_skb(new_skb); 1722 new_skb = NULL; 1723 } 1724 return new_skb; 1725 } 1726 1727 /* 1728 * Compress and send a frame. 1729 * The caller should have locked the xmit path, 1730 * and xmit_pending should be 0. 1731 */ 1732 static void 1733 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) 1734 { 1735 int proto = PPP_PROTO(skb); 1736 struct sk_buff *new_skb; 1737 int len; 1738 unsigned char *cp; 1739 1740 if (proto < 0x8000) { 1741 #ifdef CONFIG_PPP_FILTER 1742 /* check if we should pass this packet */ 1743 /* the filter instructions are constructed assuming 1744 a four-byte PPP header on each packet */ 1745 *(u8 *)skb_push(skb, 2) = 1; 1746 if (ppp->pass_filter && 1747 bpf_prog_run(ppp->pass_filter, skb) == 0) { 1748 if (ppp->debug & 1) 1749 netdev_printk(KERN_DEBUG, ppp->dev, 1750 "PPP: outbound frame " 1751 "not passed\n"); 1752 kfree_skb(skb); 1753 return; 1754 } 1755 /* if this packet passes the active filter, record the time */ 1756 if (!(ppp->active_filter && 1757 bpf_prog_run(ppp->active_filter, skb) == 0)) 1758 ppp->last_xmit = jiffies; 1759 skb_pull(skb, 2); 1760 #else 1761 /* for data packets, record the time */ 1762 ppp->last_xmit = jiffies; 1763 #endif /* CONFIG_PPP_FILTER */ 1764 } 1765 1766 ++ppp->stats64.tx_packets; 1767 ppp->stats64.tx_bytes += skb->len - 2; 1768 1769 switch (proto) { 1770 case PPP_IP: 1771 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0) 1772 break; 1773 /* try to do VJ TCP header compression */ 1774 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2, 1775 GFP_ATOMIC); 1776 if (!new_skb) { 1777 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n"); 1778 goto drop; 1779 } 1780 skb_reserve(new_skb, ppp->dev->hard_header_len - 2); 1781 cp = skb->data + 2; 1782 len = slhc_compress(ppp->vj, cp, skb->len - 2, 1783 new_skb->data + 2, &cp, 1784 !(ppp->flags & SC_NO_TCP_CCID)); 1785 if (cp == skb->data + 2) { 1786 /* didn't compress */ 1787 consume_skb(new_skb); 1788 } else { 1789 if (cp[0] & SL_TYPE_COMPRESSED_TCP) { 1790 proto = PPP_VJC_COMP; 1791 cp[0] &= ~SL_TYPE_COMPRESSED_TCP; 1792 } else { 1793 proto = PPP_VJC_UNCOMP; 1794 cp[0] = skb->data[2]; 1795 } 1796 consume_skb(skb); 1797 skb = new_skb; 1798 cp = skb_put(skb, len + 2); 1799 cp[0] = 0; 1800 cp[1] = proto; 1801 } 1802 break; 1803 1804 case PPP_CCP: 1805 /* peek at outbound CCP frames */ 1806 ppp_ccp_peek(ppp, skb, 0); 1807 break; 1808 } 1809 1810 /* try to do packet compression */ 1811 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state && 1812 proto != PPP_LCP && proto != PPP_CCP) { 1813 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) { 1814 if (net_ratelimit()) 1815 netdev_err(ppp->dev, 1816 "ppp: compression required but " 1817 "down - pkt dropped.\n"); 1818 goto drop; 1819 } 1820 skb = pad_compress_skb(ppp, skb); 1821 if (!skb) 1822 goto drop; 1823 } 1824 1825 /* 1826 * If we are waiting for traffic (demand dialling), 1827 * queue it up for pppd to receive. 1828 */ 1829 if (ppp->flags & SC_LOOP_TRAFFIC) { 1830 if (ppp->file.rq.qlen > PPP_MAX_RQLEN) 1831 goto drop; 1832 skb_queue_tail(&ppp->file.rq, skb); 1833 wake_up_interruptible(&ppp->file.rwait); 1834 return; 1835 } 1836 1837 ppp->xmit_pending = skb; 1838 ppp_push(ppp); 1839 return; 1840 1841 drop: 1842 kfree_skb(skb); 1843 ++ppp->dev->stats.tx_errors; 1844 } 1845 1846 /* 1847 * Try to send the frame in xmit_pending. 1848 * The caller should have the xmit path locked. 1849 */ 1850 static void 1851 ppp_push(struct ppp *ppp) 1852 { 1853 struct list_head *list; 1854 struct channel *pch; 1855 struct sk_buff *skb = ppp->xmit_pending; 1856 1857 if (!skb) 1858 return; 1859 1860 list = &ppp->channels; 1861 if (list_empty(list)) { 1862 /* nowhere to send the packet, just drop it */ 1863 ppp->xmit_pending = NULL; 1864 kfree_skb(skb); 1865 return; 1866 } 1867 1868 if ((ppp->flags & SC_MULTILINK) == 0) { 1869 /* not doing multilink: send it down the first channel */ 1870 list = list->next; 1871 pch = list_entry(list, struct channel, clist); 1872 1873 spin_lock(&pch->downl); 1874 if (pch->chan) { 1875 if (pch->chan->ops->start_xmit(pch->chan, skb)) 1876 ppp->xmit_pending = NULL; 1877 } else { 1878 /* channel got unregistered */ 1879 kfree_skb(skb); 1880 ppp->xmit_pending = NULL; 1881 } 1882 spin_unlock(&pch->downl); 1883 return; 1884 } 1885 1886 #ifdef CONFIG_PPP_MULTILINK 1887 /* Multilink: fragment the packet over as many links 1888 as can take the packet at the moment. */ 1889 if (!ppp_mp_explode(ppp, skb)) 1890 return; 1891 #endif /* CONFIG_PPP_MULTILINK */ 1892 1893 ppp->xmit_pending = NULL; 1894 kfree_skb(skb); 1895 } 1896 1897 #ifdef CONFIG_PPP_MULTILINK 1898 static bool mp_protocol_compress __read_mostly = true; 1899 module_param(mp_protocol_compress, bool, 0644); 1900 MODULE_PARM_DESC(mp_protocol_compress, 1901 "compress protocol id in multilink fragments"); 1902 1903 /* 1904 * Divide a packet to be transmitted into fragments and 1905 * send them out the individual links. 1906 */ 1907 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb) 1908 { 1909 int len, totlen; 1910 int i, bits, hdrlen, mtu; 1911 int flen; 1912 int navail, nfree, nzero; 1913 int nbigger; 1914 int totspeed; 1915 int totfree; 1916 unsigned char *p, *q; 1917 struct list_head *list; 1918 struct channel *pch; 1919 struct sk_buff *frag; 1920 struct ppp_channel *chan; 1921 1922 totspeed = 0; /*total bitrate of the bundle*/ 1923 nfree = 0; /* # channels which have no packet already queued */ 1924 navail = 0; /* total # of usable channels (not deregistered) */ 1925 nzero = 0; /* number of channels with zero speed associated*/ 1926 totfree = 0; /*total # of channels available and 1927 *having no queued packets before 1928 *starting the fragmentation*/ 1929 1930 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1931 i = 0; 1932 list_for_each_entry(pch, &ppp->channels, clist) { 1933 if (pch->chan) { 1934 pch->avail = 1; 1935 navail++; 1936 pch->speed = pch->chan->speed; 1937 } else { 1938 pch->avail = 0; 1939 } 1940 if (pch->avail) { 1941 if (skb_queue_empty(&pch->file.xq) || 1942 !pch->had_frag) { 1943 if (pch->speed == 0) 1944 nzero++; 1945 else 1946 totspeed += pch->speed; 1947 1948 pch->avail = 2; 1949 ++nfree; 1950 ++totfree; 1951 } 1952 if (!pch->had_frag && i < ppp->nxchan) 1953 ppp->nxchan = i; 1954 } 1955 ++i; 1956 } 1957 /* 1958 * Don't start sending this packet unless at least half of 1959 * the channels are free. This gives much better TCP 1960 * performance if we have a lot of channels. 1961 */ 1962 if (nfree == 0 || nfree < navail / 2) 1963 return 0; /* can't take now, leave it in xmit_pending */ 1964 1965 /* Do protocol field compression */ 1966 p = skb->data; 1967 len = skb->len; 1968 if (*p == 0 && mp_protocol_compress) { 1969 ++p; 1970 --len; 1971 } 1972 1973 totlen = len; 1974 nbigger = len % nfree; 1975 1976 /* skip to the channel after the one we last used 1977 and start at that one */ 1978 list = &ppp->channels; 1979 for (i = 0; i < ppp->nxchan; ++i) { 1980 list = list->next; 1981 if (list == &ppp->channels) { 1982 i = 0; 1983 break; 1984 } 1985 } 1986 1987 /* create a fragment for each channel */ 1988 bits = B; 1989 while (len > 0) { 1990 list = list->next; 1991 if (list == &ppp->channels) { 1992 i = 0; 1993 continue; 1994 } 1995 pch = list_entry(list, struct channel, clist); 1996 ++i; 1997 if (!pch->avail) 1998 continue; 1999 2000 /* 2001 * Skip this channel if it has a fragment pending already and 2002 * we haven't given a fragment to all of the free channels. 2003 */ 2004 if (pch->avail == 1) { 2005 if (nfree > 0) 2006 continue; 2007 } else { 2008 pch->avail = 1; 2009 } 2010 2011 /* check the channel's mtu and whether it is still attached. */ 2012 spin_lock(&pch->downl); 2013 if (pch->chan == NULL) { 2014 /* can't use this channel, it's being deregistered */ 2015 if (pch->speed == 0) 2016 nzero--; 2017 else 2018 totspeed -= pch->speed; 2019 2020 spin_unlock(&pch->downl); 2021 pch->avail = 0; 2022 totlen = len; 2023 totfree--; 2024 nfree--; 2025 if (--navail == 0) 2026 break; 2027 continue; 2028 } 2029 2030 /* 2031 *if the channel speed is not set divide 2032 *the packet evenly among the free channels; 2033 *otherwise divide it according to the speed 2034 *of the channel we are going to transmit on 2035 */ 2036 flen = len; 2037 if (nfree > 0) { 2038 if (pch->speed == 0) { 2039 flen = len/nfree; 2040 if (nbigger > 0) { 2041 flen++; 2042 nbigger--; 2043 } 2044 } else { 2045 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) / 2046 ((totspeed*totfree)/pch->speed)) - hdrlen; 2047 if (nbigger > 0) { 2048 flen += ((totfree - nzero)*pch->speed)/totspeed; 2049 nbigger -= ((totfree - nzero)*pch->speed)/ 2050 totspeed; 2051 } 2052 } 2053 nfree--; 2054 } 2055 2056 /* 2057 *check if we are on the last channel or 2058 *we exceded the length of the data to 2059 *fragment 2060 */ 2061 if ((nfree <= 0) || (flen > len)) 2062 flen = len; 2063 /* 2064 *it is not worth to tx on slow channels: 2065 *in that case from the resulting flen according to the 2066 *above formula will be equal or less than zero. 2067 *Skip the channel in this case 2068 */ 2069 if (flen <= 0) { 2070 pch->avail = 2; 2071 spin_unlock(&pch->downl); 2072 continue; 2073 } 2074 2075 /* 2076 * hdrlen includes the 2-byte PPP protocol field, but the 2077 * MTU counts only the payload excluding the protocol field. 2078 * (RFC1661 Section 2) 2079 */ 2080 mtu = pch->chan->mtu - (hdrlen - 2); 2081 if (mtu < 4) 2082 mtu = 4; 2083 if (flen > mtu) 2084 flen = mtu; 2085 if (flen == len) 2086 bits |= E; 2087 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC); 2088 if (!frag) 2089 goto noskb; 2090 q = skb_put(frag, flen + hdrlen); 2091 2092 /* make the MP header */ 2093 put_unaligned_be16(PPP_MP, q); 2094 if (ppp->flags & SC_MP_XSHORTSEQ) { 2095 q[2] = bits + ((ppp->nxseq >> 8) & 0xf); 2096 q[3] = ppp->nxseq; 2097 } else { 2098 q[2] = bits; 2099 q[3] = ppp->nxseq >> 16; 2100 q[4] = ppp->nxseq >> 8; 2101 q[5] = ppp->nxseq; 2102 } 2103 2104 memcpy(q + hdrlen, p, flen); 2105 2106 /* try to send it down the channel */ 2107 chan = pch->chan; 2108 if (!skb_queue_empty(&pch->file.xq) || 2109 !chan->ops->start_xmit(chan, frag)) 2110 skb_queue_tail(&pch->file.xq, frag); 2111 pch->had_frag = 1; 2112 p += flen; 2113 len -= flen; 2114 ++ppp->nxseq; 2115 bits = 0; 2116 spin_unlock(&pch->downl); 2117 } 2118 ppp->nxchan = i; 2119 2120 return 1; 2121 2122 noskb: 2123 spin_unlock(&pch->downl); 2124 if (ppp->debug & 1) 2125 netdev_err(ppp->dev, "PPP: no memory (fragment)\n"); 2126 ++ppp->dev->stats.tx_errors; 2127 ++ppp->nxseq; 2128 return 1; /* abandon the frame */ 2129 } 2130 #endif /* CONFIG_PPP_MULTILINK */ 2131 2132 /* Try to send data out on a channel */ 2133 static void __ppp_channel_push(struct channel *pch) 2134 { 2135 struct sk_buff *skb; 2136 struct ppp *ppp; 2137 2138 spin_lock(&pch->downl); 2139 if (pch->chan) { 2140 while (!skb_queue_empty(&pch->file.xq)) { 2141 skb = skb_dequeue(&pch->file.xq); 2142 if (!pch->chan->ops->start_xmit(pch->chan, skb)) { 2143 /* put the packet back and try again later */ 2144 skb_queue_head(&pch->file.xq, skb); 2145 break; 2146 } 2147 } 2148 } else { 2149 /* channel got deregistered */ 2150 skb_queue_purge(&pch->file.xq); 2151 } 2152 spin_unlock(&pch->downl); 2153 /* see if there is anything from the attached unit to be sent */ 2154 if (skb_queue_empty(&pch->file.xq)) { 2155 ppp = pch->ppp; 2156 if (ppp) 2157 __ppp_xmit_process(ppp, NULL); 2158 } 2159 } 2160 2161 static void ppp_channel_push(struct channel *pch) 2162 { 2163 read_lock_bh(&pch->upl); 2164 if (pch->ppp) { 2165 (*this_cpu_ptr(pch->ppp->xmit_recursion))++; 2166 __ppp_channel_push(pch); 2167 (*this_cpu_ptr(pch->ppp->xmit_recursion))--; 2168 } else { 2169 __ppp_channel_push(pch); 2170 } 2171 read_unlock_bh(&pch->upl); 2172 } 2173 2174 /* 2175 * Receive-side routines. 2176 */ 2177 2178 struct ppp_mp_skb_parm { 2179 u32 sequence; 2180 u8 BEbits; 2181 }; 2182 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb)) 2183 2184 static inline void 2185 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2186 { 2187 ppp_recv_lock(ppp); 2188 if (!ppp->closing) 2189 ppp_receive_frame(ppp, skb, pch); 2190 else 2191 kfree_skb(skb); 2192 ppp_recv_unlock(ppp); 2193 } 2194 2195 /** 2196 * __ppp_decompress_proto - Decompress protocol field, slim version. 2197 * @skb: Socket buffer where protocol field should be decompressed. It must have 2198 * at least 1 byte of head room and 1 byte of linear data. First byte of 2199 * data must be a protocol field byte. 2200 * 2201 * Decompress protocol field in PPP header if it's compressed, e.g. when 2202 * Protocol-Field-Compression (PFC) was negotiated. No checks w.r.t. skb data 2203 * length are done in this function. 2204 */ 2205 static void __ppp_decompress_proto(struct sk_buff *skb) 2206 { 2207 if (skb->data[0] & 0x01) 2208 *(u8 *)skb_push(skb, 1) = 0x00; 2209 } 2210 2211 /** 2212 * ppp_decompress_proto - Check skb data room and decompress protocol field. 2213 * @skb: Socket buffer where protocol field should be decompressed. First byte 2214 * of data must be a protocol field byte. 2215 * 2216 * Decompress protocol field in PPP header if it's compressed, e.g. when 2217 * Protocol-Field-Compression (PFC) was negotiated. This function also makes 2218 * sure that skb data room is sufficient for Protocol field, before and after 2219 * decompression. 2220 * 2221 * Return: true - decompressed successfully, false - not enough room in skb. 2222 */ 2223 static bool ppp_decompress_proto(struct sk_buff *skb) 2224 { 2225 /* At least one byte should be present (if protocol is compressed) */ 2226 if (!pskb_may_pull(skb, 1)) 2227 return false; 2228 2229 __ppp_decompress_proto(skb); 2230 2231 /* Protocol field should occupy 2 bytes when not compressed */ 2232 return pskb_may_pull(skb, 2); 2233 } 2234 2235 /* Attempt to handle a frame via. a bridged channel, if one exists. 2236 * If the channel is bridged, the frame is consumed by the bridge. 2237 * If not, the caller must handle the frame by normal recv mechanisms. 2238 * Returns true if the frame is consumed, false otherwise. 2239 */ 2240 static bool ppp_channel_bridge_input(struct channel *pch, struct sk_buff *skb) 2241 { 2242 struct channel *pchb; 2243 2244 rcu_read_lock(); 2245 pchb = rcu_dereference(pch->bridge); 2246 if (!pchb) 2247 goto out_rcu; 2248 2249 spin_lock(&pchb->downl); 2250 if (!pchb->chan) { 2251 /* channel got unregistered */ 2252 kfree_skb(skb); 2253 goto outl; 2254 } 2255 2256 skb_scrub_packet(skb, !net_eq(pch->chan_net, pchb->chan_net)); 2257 if (!pchb->chan->ops->start_xmit(pchb->chan, skb)) 2258 kfree_skb(skb); 2259 2260 outl: 2261 spin_unlock(&pchb->downl); 2262 out_rcu: 2263 rcu_read_unlock(); 2264 2265 /* If pchb is set then we've consumed the packet */ 2266 return !!pchb; 2267 } 2268 2269 void 2270 ppp_input(struct ppp_channel *chan, struct sk_buff *skb) 2271 { 2272 struct channel *pch = chan->ppp; 2273 int proto; 2274 2275 if (!pch) { 2276 kfree_skb(skb); 2277 return; 2278 } 2279 2280 /* If the channel is bridged, transmit via. bridge */ 2281 if (ppp_channel_bridge_input(pch, skb)) 2282 return; 2283 2284 read_lock_bh(&pch->upl); 2285 if (!ppp_decompress_proto(skb)) { 2286 kfree_skb(skb); 2287 if (pch->ppp) { 2288 ++pch->ppp->dev->stats.rx_length_errors; 2289 ppp_receive_error(pch->ppp); 2290 } 2291 goto done; 2292 } 2293 2294 proto = PPP_PROTO(skb); 2295 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) { 2296 /* put it on the channel queue */ 2297 skb_queue_tail(&pch->file.rq, skb); 2298 /* drop old frames if queue too long */ 2299 while (pch->file.rq.qlen > PPP_MAX_RQLEN && 2300 (skb = skb_dequeue(&pch->file.rq))) 2301 kfree_skb(skb); 2302 wake_up_interruptible(&pch->file.rwait); 2303 } else { 2304 ppp_do_recv(pch->ppp, skb, pch); 2305 } 2306 2307 done: 2308 read_unlock_bh(&pch->upl); 2309 } 2310 2311 /* Put a 0-length skb in the receive queue as an error indication */ 2312 void 2313 ppp_input_error(struct ppp_channel *chan, int code) 2314 { 2315 struct channel *pch = chan->ppp; 2316 struct sk_buff *skb; 2317 2318 if (!pch) 2319 return; 2320 2321 read_lock_bh(&pch->upl); 2322 if (pch->ppp) { 2323 skb = alloc_skb(0, GFP_ATOMIC); 2324 if (skb) { 2325 skb->len = 0; /* probably unnecessary */ 2326 skb->cb[0] = code; 2327 ppp_do_recv(pch->ppp, skb, pch); 2328 } 2329 } 2330 read_unlock_bh(&pch->upl); 2331 } 2332 2333 /* 2334 * We come in here to process a received frame. 2335 * The receive side of the ppp unit is locked. 2336 */ 2337 static void 2338 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2339 { 2340 /* note: a 0-length skb is used as an error indication */ 2341 if (skb->len > 0) { 2342 skb_checksum_complete_unset(skb); 2343 #ifdef CONFIG_PPP_MULTILINK 2344 /* XXX do channel-level decompression here */ 2345 if (PPP_PROTO(skb) == PPP_MP) 2346 ppp_receive_mp_frame(ppp, skb, pch); 2347 else 2348 #endif /* CONFIG_PPP_MULTILINK */ 2349 ppp_receive_nonmp_frame(ppp, skb); 2350 } else { 2351 kfree_skb(skb); 2352 ppp_receive_error(ppp); 2353 } 2354 } 2355 2356 static void 2357 ppp_receive_error(struct ppp *ppp) 2358 { 2359 ++ppp->dev->stats.rx_errors; 2360 if (ppp->vj) 2361 slhc_toss(ppp->vj); 2362 } 2363 2364 static void 2365 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) 2366 { 2367 struct sk_buff *ns; 2368 int proto, len, npi; 2369 2370 /* 2371 * Decompress the frame, if compressed. 2372 * Note that some decompressors need to see uncompressed frames 2373 * that come in as well as compressed frames. 2374 */ 2375 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) && 2376 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0) 2377 skb = ppp_decompress_frame(ppp, skb); 2378 2379 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR) 2380 goto err; 2381 2382 /* At this point the "Protocol" field MUST be decompressed, either in 2383 * ppp_input(), ppp_decompress_frame() or in ppp_receive_mp_frame(). 2384 */ 2385 proto = PPP_PROTO(skb); 2386 switch (proto) { 2387 case PPP_VJC_COMP: 2388 /* decompress VJ compressed packets */ 2389 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 2390 goto err; 2391 2392 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) { 2393 /* copy to a new sk_buff with more tailroom */ 2394 ns = dev_alloc_skb(skb->len + 128); 2395 if (!ns) { 2396 netdev_err(ppp->dev, "PPP: no memory " 2397 "(VJ decomp)\n"); 2398 goto err; 2399 } 2400 skb_reserve(ns, 2); 2401 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len); 2402 consume_skb(skb); 2403 skb = ns; 2404 } 2405 else 2406 skb->ip_summed = CHECKSUM_NONE; 2407 2408 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2); 2409 if (len <= 0) { 2410 netdev_printk(KERN_DEBUG, ppp->dev, 2411 "PPP: VJ decompression error\n"); 2412 goto err; 2413 } 2414 len += 2; 2415 if (len > skb->len) 2416 skb_put(skb, len - skb->len); 2417 else if (len < skb->len) 2418 skb_trim(skb, len); 2419 proto = PPP_IP; 2420 break; 2421 2422 case PPP_VJC_UNCOMP: 2423 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 2424 goto err; 2425 2426 /* Until we fix the decompressor need to make sure 2427 * data portion is linear. 2428 */ 2429 if (!pskb_may_pull(skb, skb->len)) 2430 goto err; 2431 2432 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) { 2433 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n"); 2434 goto err; 2435 } 2436 proto = PPP_IP; 2437 break; 2438 2439 case PPP_CCP: 2440 ppp_ccp_peek(ppp, skb, 1); 2441 break; 2442 } 2443 2444 ++ppp->stats64.rx_packets; 2445 ppp->stats64.rx_bytes += skb->len - 2; 2446 2447 npi = proto_to_npindex(proto); 2448 if (npi < 0) { 2449 /* control or unknown frame - pass it to pppd */ 2450 skb_queue_tail(&ppp->file.rq, skb); 2451 /* limit queue length by dropping old frames */ 2452 while (ppp->file.rq.qlen > PPP_MAX_RQLEN && 2453 (skb = skb_dequeue(&ppp->file.rq))) 2454 kfree_skb(skb); 2455 /* wake up any process polling or blocking on read */ 2456 wake_up_interruptible(&ppp->file.rwait); 2457 2458 } else { 2459 /* network protocol frame - give it to the kernel */ 2460 2461 #ifdef CONFIG_PPP_FILTER 2462 /* check if the packet passes the pass and active filters */ 2463 /* the filter instructions are constructed assuming 2464 a four-byte PPP header on each packet */ 2465 if (ppp->pass_filter || ppp->active_filter) { 2466 if (skb_unclone(skb, GFP_ATOMIC)) 2467 goto err; 2468 2469 *(u8 *)skb_push(skb, 2) = 0; 2470 if (ppp->pass_filter && 2471 bpf_prog_run(ppp->pass_filter, skb) == 0) { 2472 if (ppp->debug & 1) 2473 netdev_printk(KERN_DEBUG, ppp->dev, 2474 "PPP: inbound frame " 2475 "not passed\n"); 2476 kfree_skb(skb); 2477 return; 2478 } 2479 if (!(ppp->active_filter && 2480 bpf_prog_run(ppp->active_filter, skb) == 0)) 2481 ppp->last_recv = jiffies; 2482 __skb_pull(skb, 2); 2483 } else 2484 #endif /* CONFIG_PPP_FILTER */ 2485 ppp->last_recv = jiffies; 2486 2487 if ((ppp->dev->flags & IFF_UP) == 0 || 2488 ppp->npmode[npi] != NPMODE_PASS) { 2489 kfree_skb(skb); 2490 } else { 2491 /* chop off protocol */ 2492 skb_pull_rcsum(skb, 2); 2493 skb->dev = ppp->dev; 2494 skb->protocol = htons(npindex_to_ethertype[npi]); 2495 skb_reset_mac_header(skb); 2496 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, 2497 dev_net(ppp->dev))); 2498 netif_rx(skb); 2499 } 2500 } 2501 return; 2502 2503 err: 2504 kfree_skb(skb); 2505 ppp_receive_error(ppp); 2506 } 2507 2508 static struct sk_buff * 2509 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb) 2510 { 2511 int proto = PPP_PROTO(skb); 2512 struct sk_buff *ns; 2513 int len; 2514 2515 /* Until we fix all the decompressor's need to make sure 2516 * data portion is linear. 2517 */ 2518 if (!pskb_may_pull(skb, skb->len)) 2519 goto err; 2520 2521 if (proto == PPP_COMP) { 2522 int obuff_size; 2523 2524 switch(ppp->rcomp->compress_proto) { 2525 case CI_MPPE: 2526 obuff_size = ppp->mru + PPP_HDRLEN + 1; 2527 break; 2528 default: 2529 obuff_size = ppp->mru + PPP_HDRLEN; 2530 break; 2531 } 2532 2533 ns = dev_alloc_skb(obuff_size); 2534 if (!ns) { 2535 netdev_err(ppp->dev, "ppp_decompress_frame: " 2536 "no memory\n"); 2537 goto err; 2538 } 2539 /* the decompressor still expects the A/C bytes in the hdr */ 2540 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2, 2541 skb->len + 2, ns->data, obuff_size); 2542 if (len < 0) { 2543 /* Pass the compressed frame to pppd as an 2544 error indication. */ 2545 if (len == DECOMP_FATALERROR) 2546 ppp->rstate |= SC_DC_FERROR; 2547 kfree_skb(ns); 2548 goto err; 2549 } 2550 2551 consume_skb(skb); 2552 skb = ns; 2553 skb_put(skb, len); 2554 skb_pull(skb, 2); /* pull off the A/C bytes */ 2555 2556 /* Don't call __ppp_decompress_proto() here, but instead rely on 2557 * corresponding algo (mppe/bsd/deflate) to decompress it. 2558 */ 2559 } else { 2560 /* Uncompressed frame - pass to decompressor so it 2561 can update its dictionary if necessary. */ 2562 if (ppp->rcomp->incomp) 2563 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2, 2564 skb->len + 2); 2565 } 2566 2567 return skb; 2568 2569 err: 2570 ppp->rstate |= SC_DC_ERROR; 2571 ppp_receive_error(ppp); 2572 return skb; 2573 } 2574 2575 #ifdef CONFIG_PPP_MULTILINK 2576 /* 2577 * Receive a multilink frame. 2578 * We put it on the reconstruction queue and then pull off 2579 * as many completed frames as we can. 2580 */ 2581 static void 2582 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2583 { 2584 u32 mask, seq; 2585 struct channel *ch; 2586 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 2587 2588 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0) 2589 goto err; /* no good, throw it away */ 2590 2591 /* Decode sequence number and begin/end bits */ 2592 if (ppp->flags & SC_MP_SHORTSEQ) { 2593 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3]; 2594 mask = 0xfff; 2595 } else { 2596 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5]; 2597 mask = 0xffffff; 2598 } 2599 PPP_MP_CB(skb)->BEbits = skb->data[2]; 2600 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */ 2601 2602 /* 2603 * Do protocol ID decompression on the first fragment of each packet. 2604 * We have to do that here, because ppp_receive_nonmp_frame() expects 2605 * decompressed protocol field. 2606 */ 2607 if (PPP_MP_CB(skb)->BEbits & B) 2608 __ppp_decompress_proto(skb); 2609 2610 /* 2611 * Expand sequence number to 32 bits, making it as close 2612 * as possible to ppp->minseq. 2613 */ 2614 seq |= ppp->minseq & ~mask; 2615 if ((int)(ppp->minseq - seq) > (int)(mask >> 1)) 2616 seq += mask + 1; 2617 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1)) 2618 seq -= mask + 1; /* should never happen */ 2619 PPP_MP_CB(skb)->sequence = seq; 2620 pch->lastseq = seq; 2621 2622 /* 2623 * If this packet comes before the next one we were expecting, 2624 * drop it. 2625 */ 2626 if (seq_before(seq, ppp->nextseq)) { 2627 kfree_skb(skb); 2628 ++ppp->dev->stats.rx_dropped; 2629 ppp_receive_error(ppp); 2630 return; 2631 } 2632 2633 /* 2634 * Reevaluate minseq, the minimum over all channels of the 2635 * last sequence number received on each channel. Because of 2636 * the increasing sequence number rule, we know that any fragment 2637 * before `minseq' which hasn't arrived is never going to arrive. 2638 * The list of channels can't change because we have the receive 2639 * side of the ppp unit locked. 2640 */ 2641 list_for_each_entry(ch, &ppp->channels, clist) { 2642 if (seq_before(ch->lastseq, seq)) 2643 seq = ch->lastseq; 2644 } 2645 if (seq_before(ppp->minseq, seq)) 2646 ppp->minseq = seq; 2647 2648 /* Put the fragment on the reconstruction queue */ 2649 ppp_mp_insert(ppp, skb); 2650 2651 /* If the queue is getting long, don't wait any longer for packets 2652 before the start of the queue. */ 2653 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) { 2654 struct sk_buff *mskb = skb_peek(&ppp->mrq); 2655 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence)) 2656 ppp->minseq = PPP_MP_CB(mskb)->sequence; 2657 } 2658 2659 /* Pull completed packets off the queue and receive them. */ 2660 while ((skb = ppp_mp_reconstruct(ppp))) { 2661 if (pskb_may_pull(skb, 2)) 2662 ppp_receive_nonmp_frame(ppp, skb); 2663 else { 2664 ++ppp->dev->stats.rx_length_errors; 2665 kfree_skb(skb); 2666 ppp_receive_error(ppp); 2667 } 2668 } 2669 2670 return; 2671 2672 err: 2673 kfree_skb(skb); 2674 ppp_receive_error(ppp); 2675 } 2676 2677 /* 2678 * Insert a fragment on the MP reconstruction queue. 2679 * The queue is ordered by increasing sequence number. 2680 */ 2681 static void 2682 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb) 2683 { 2684 struct sk_buff *p; 2685 struct sk_buff_head *list = &ppp->mrq; 2686 u32 seq = PPP_MP_CB(skb)->sequence; 2687 2688 /* N.B. we don't need to lock the list lock because we have the 2689 ppp unit receive-side lock. */ 2690 skb_queue_walk(list, p) { 2691 if (seq_before(seq, PPP_MP_CB(p)->sequence)) 2692 break; 2693 } 2694 __skb_queue_before(list, p, skb); 2695 } 2696 2697 /* 2698 * Reconstruct a packet from the MP fragment queue. 2699 * We go through increasing sequence numbers until we find a 2700 * complete packet, or we get to the sequence number for a fragment 2701 * which hasn't arrived but might still do so. 2702 */ 2703 static struct sk_buff * 2704 ppp_mp_reconstruct(struct ppp *ppp) 2705 { 2706 u32 seq = ppp->nextseq; 2707 u32 minseq = ppp->minseq; 2708 struct sk_buff_head *list = &ppp->mrq; 2709 struct sk_buff *p, *tmp; 2710 struct sk_buff *head, *tail; 2711 struct sk_buff *skb = NULL; 2712 int lost = 0, len = 0; 2713 2714 if (ppp->mrru == 0) /* do nothing until mrru is set */ 2715 return NULL; 2716 head = __skb_peek(list); 2717 tail = NULL; 2718 skb_queue_walk_safe(list, p, tmp) { 2719 again: 2720 if (seq_before(PPP_MP_CB(p)->sequence, seq)) { 2721 /* this can't happen, anyway ignore the skb */ 2722 netdev_err(ppp->dev, "ppp_mp_reconstruct bad " 2723 "seq %u < %u\n", 2724 PPP_MP_CB(p)->sequence, seq); 2725 __skb_unlink(p, list); 2726 kfree_skb(p); 2727 continue; 2728 } 2729 if (PPP_MP_CB(p)->sequence != seq) { 2730 u32 oldseq; 2731 /* Fragment `seq' is missing. If it is after 2732 minseq, it might arrive later, so stop here. */ 2733 if (seq_after(seq, minseq)) 2734 break; 2735 /* Fragment `seq' is lost, keep going. */ 2736 lost = 1; 2737 oldseq = seq; 2738 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)? 2739 minseq + 1: PPP_MP_CB(p)->sequence; 2740 2741 if (ppp->debug & 1) 2742 netdev_printk(KERN_DEBUG, ppp->dev, 2743 "lost frag %u..%u\n", 2744 oldseq, seq-1); 2745 2746 goto again; 2747 } 2748 2749 /* 2750 * At this point we know that all the fragments from 2751 * ppp->nextseq to seq are either present or lost. 2752 * Also, there are no complete packets in the queue 2753 * that have no missing fragments and end before this 2754 * fragment. 2755 */ 2756 2757 /* B bit set indicates this fragment starts a packet */ 2758 if (PPP_MP_CB(p)->BEbits & B) { 2759 head = p; 2760 lost = 0; 2761 len = 0; 2762 } 2763 2764 len += p->len; 2765 2766 /* Got a complete packet yet? */ 2767 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) && 2768 (PPP_MP_CB(head)->BEbits & B)) { 2769 if (len > ppp->mrru + 2) { 2770 ++ppp->dev->stats.rx_length_errors; 2771 netdev_printk(KERN_DEBUG, ppp->dev, 2772 "PPP: reconstructed packet" 2773 " is too long (%d)\n", len); 2774 } else { 2775 tail = p; 2776 break; 2777 } 2778 ppp->nextseq = seq + 1; 2779 } 2780 2781 /* 2782 * If this is the ending fragment of a packet, 2783 * and we haven't found a complete valid packet yet, 2784 * we can discard up to and including this fragment. 2785 */ 2786 if (PPP_MP_CB(p)->BEbits & E) { 2787 struct sk_buff *tmp2; 2788 2789 skb_queue_reverse_walk_from_safe(list, p, tmp2) { 2790 if (ppp->debug & 1) 2791 netdev_printk(KERN_DEBUG, ppp->dev, 2792 "discarding frag %u\n", 2793 PPP_MP_CB(p)->sequence); 2794 __skb_unlink(p, list); 2795 kfree_skb(p); 2796 } 2797 head = skb_peek(list); 2798 if (!head) 2799 break; 2800 } 2801 ++seq; 2802 } 2803 2804 /* If we have a complete packet, copy it all into one skb. */ 2805 if (tail != NULL) { 2806 /* If we have discarded any fragments, 2807 signal a receive error. */ 2808 if (PPP_MP_CB(head)->sequence != ppp->nextseq) { 2809 skb_queue_walk_safe(list, p, tmp) { 2810 if (p == head) 2811 break; 2812 if (ppp->debug & 1) 2813 netdev_printk(KERN_DEBUG, ppp->dev, 2814 "discarding frag %u\n", 2815 PPP_MP_CB(p)->sequence); 2816 __skb_unlink(p, list); 2817 kfree_skb(p); 2818 } 2819 2820 if (ppp->debug & 1) 2821 netdev_printk(KERN_DEBUG, ppp->dev, 2822 " missed pkts %u..%u\n", 2823 ppp->nextseq, 2824 PPP_MP_CB(head)->sequence-1); 2825 ++ppp->dev->stats.rx_dropped; 2826 ppp_receive_error(ppp); 2827 } 2828 2829 skb = head; 2830 if (head != tail) { 2831 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list; 2832 p = skb_queue_next(list, head); 2833 __skb_unlink(skb, list); 2834 skb_queue_walk_from_safe(list, p, tmp) { 2835 __skb_unlink(p, list); 2836 *fragpp = p; 2837 p->next = NULL; 2838 fragpp = &p->next; 2839 2840 skb->len += p->len; 2841 skb->data_len += p->len; 2842 skb->truesize += p->truesize; 2843 2844 if (p == tail) 2845 break; 2846 } 2847 } else { 2848 __skb_unlink(skb, list); 2849 } 2850 2851 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1; 2852 } 2853 2854 return skb; 2855 } 2856 #endif /* CONFIG_PPP_MULTILINK */ 2857 2858 /* 2859 * Channel interface. 2860 */ 2861 2862 /* Create a new, unattached ppp channel. */ 2863 int ppp_register_channel(struct ppp_channel *chan) 2864 { 2865 return ppp_register_net_channel(current->nsproxy->net_ns, chan); 2866 } 2867 2868 /* Create a new, unattached ppp channel for specified net. */ 2869 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan) 2870 { 2871 struct channel *pch; 2872 struct ppp_net *pn; 2873 2874 pch = kzalloc(sizeof(struct channel), GFP_KERNEL); 2875 if (!pch) 2876 return -ENOMEM; 2877 2878 pn = ppp_pernet(net); 2879 2880 pch->ppp = NULL; 2881 pch->chan = chan; 2882 pch->chan_net = get_net(net); 2883 chan->ppp = pch; 2884 init_ppp_file(&pch->file, CHANNEL); 2885 pch->file.hdrlen = chan->hdrlen; 2886 #ifdef CONFIG_PPP_MULTILINK 2887 pch->lastseq = -1; 2888 #endif /* CONFIG_PPP_MULTILINK */ 2889 init_rwsem(&pch->chan_sem); 2890 spin_lock_init(&pch->downl); 2891 rwlock_init(&pch->upl); 2892 2893 spin_lock_bh(&pn->all_channels_lock); 2894 pch->file.index = ++pn->last_channel_index; 2895 list_add(&pch->list, &pn->new_channels); 2896 atomic_inc(&channel_count); 2897 spin_unlock_bh(&pn->all_channels_lock); 2898 2899 return 0; 2900 } 2901 2902 /* 2903 * Return the index of a channel. 2904 */ 2905 int ppp_channel_index(struct ppp_channel *chan) 2906 { 2907 struct channel *pch = chan->ppp; 2908 2909 if (pch) 2910 return pch->file.index; 2911 return -1; 2912 } 2913 2914 /* 2915 * Return the PPP unit number to which a channel is connected. 2916 */ 2917 int ppp_unit_number(struct ppp_channel *chan) 2918 { 2919 struct channel *pch = chan->ppp; 2920 int unit = -1; 2921 2922 if (pch) { 2923 read_lock_bh(&pch->upl); 2924 if (pch->ppp) 2925 unit = pch->ppp->file.index; 2926 read_unlock_bh(&pch->upl); 2927 } 2928 return unit; 2929 } 2930 2931 /* 2932 * Return the PPP device interface name of a channel. 2933 */ 2934 char *ppp_dev_name(struct ppp_channel *chan) 2935 { 2936 struct channel *pch = chan->ppp; 2937 char *name = NULL; 2938 2939 if (pch) { 2940 read_lock_bh(&pch->upl); 2941 if (pch->ppp && pch->ppp->dev) 2942 name = pch->ppp->dev->name; 2943 read_unlock_bh(&pch->upl); 2944 } 2945 return name; 2946 } 2947 2948 2949 /* 2950 * Disconnect a channel from the generic layer. 2951 * This must be called in process context. 2952 */ 2953 void 2954 ppp_unregister_channel(struct ppp_channel *chan) 2955 { 2956 struct channel *pch = chan->ppp; 2957 struct ppp_net *pn; 2958 2959 if (!pch) 2960 return; /* should never happen */ 2961 2962 chan->ppp = NULL; 2963 2964 /* 2965 * This ensures that we have returned from any calls into the 2966 * the channel's start_xmit or ioctl routine before we proceed. 2967 */ 2968 down_write(&pch->chan_sem); 2969 spin_lock_bh(&pch->downl); 2970 pch->chan = NULL; 2971 spin_unlock_bh(&pch->downl); 2972 up_write(&pch->chan_sem); 2973 ppp_disconnect_channel(pch); 2974 2975 pn = ppp_pernet(pch->chan_net); 2976 spin_lock_bh(&pn->all_channels_lock); 2977 list_del(&pch->list); 2978 spin_unlock_bh(&pn->all_channels_lock); 2979 2980 ppp_unbridge_channels(pch); 2981 2982 pch->file.dead = 1; 2983 wake_up_interruptible(&pch->file.rwait); 2984 2985 if (refcount_dec_and_test(&pch->file.refcnt)) 2986 ppp_destroy_channel(pch); 2987 } 2988 2989 /* 2990 * Callback from a channel when it can accept more to transmit. 2991 * This should be called at BH/softirq level, not interrupt level. 2992 */ 2993 void 2994 ppp_output_wakeup(struct ppp_channel *chan) 2995 { 2996 struct channel *pch = chan->ppp; 2997 2998 if (!pch) 2999 return; 3000 ppp_channel_push(pch); 3001 } 3002 3003 /* 3004 * Compression control. 3005 */ 3006 3007 /* Process the PPPIOCSCOMPRESS ioctl. */ 3008 static int 3009 ppp_set_compress(struct ppp *ppp, struct ppp_option_data *data) 3010 { 3011 int err = -EFAULT; 3012 struct compressor *cp, *ocomp; 3013 void *state, *ostate; 3014 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH]; 3015 3016 if (data->length > CCP_MAX_OPTION_LENGTH) 3017 goto out; 3018 if (copy_from_user(ccp_option, data->ptr, data->length)) 3019 goto out; 3020 3021 err = -EINVAL; 3022 if (data->length < 2 || ccp_option[1] < 2 || ccp_option[1] > data->length) 3023 goto out; 3024 3025 cp = try_then_request_module( 3026 find_compressor(ccp_option[0]), 3027 "ppp-compress-%d", ccp_option[0]); 3028 if (!cp) 3029 goto out; 3030 3031 err = -ENOBUFS; 3032 if (data->transmit) { 3033 state = cp->comp_alloc(ccp_option, data->length); 3034 if (state) { 3035 ppp_xmit_lock(ppp); 3036 ppp->xstate &= ~SC_COMP_RUN; 3037 ocomp = ppp->xcomp; 3038 ostate = ppp->xc_state; 3039 ppp->xcomp = cp; 3040 ppp->xc_state = state; 3041 ppp_xmit_unlock(ppp); 3042 if (ostate) { 3043 ocomp->comp_free(ostate); 3044 module_put(ocomp->owner); 3045 } 3046 err = 0; 3047 } else 3048 module_put(cp->owner); 3049 3050 } else { 3051 state = cp->decomp_alloc(ccp_option, data->length); 3052 if (state) { 3053 ppp_recv_lock(ppp); 3054 ppp->rstate &= ~SC_DECOMP_RUN; 3055 ocomp = ppp->rcomp; 3056 ostate = ppp->rc_state; 3057 ppp->rcomp = cp; 3058 ppp->rc_state = state; 3059 ppp_recv_unlock(ppp); 3060 if (ostate) { 3061 ocomp->decomp_free(ostate); 3062 module_put(ocomp->owner); 3063 } 3064 err = 0; 3065 } else 3066 module_put(cp->owner); 3067 } 3068 3069 out: 3070 return err; 3071 } 3072 3073 /* 3074 * Look at a CCP packet and update our state accordingly. 3075 * We assume the caller has the xmit or recv path locked. 3076 */ 3077 static void 3078 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound) 3079 { 3080 unsigned char *dp; 3081 int len; 3082 3083 if (!pskb_may_pull(skb, CCP_HDRLEN + 2)) 3084 return; /* no header */ 3085 dp = skb->data + 2; 3086 3087 switch (CCP_CODE(dp)) { 3088 case CCP_CONFREQ: 3089 3090 /* A ConfReq starts negotiation of compression 3091 * in one direction of transmission, 3092 * and hence brings it down...but which way? 3093 * 3094 * Remember: 3095 * A ConfReq indicates what the sender would like to receive 3096 */ 3097 if(inbound) 3098 /* He is proposing what I should send */ 3099 ppp->xstate &= ~SC_COMP_RUN; 3100 else 3101 /* I am proposing to what he should send */ 3102 ppp->rstate &= ~SC_DECOMP_RUN; 3103 3104 break; 3105 3106 case CCP_TERMREQ: 3107 case CCP_TERMACK: 3108 /* 3109 * CCP is going down, both directions of transmission 3110 */ 3111 ppp->rstate &= ~SC_DECOMP_RUN; 3112 ppp->xstate &= ~SC_COMP_RUN; 3113 break; 3114 3115 case CCP_CONFACK: 3116 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN) 3117 break; 3118 len = CCP_LENGTH(dp); 3119 if (!pskb_may_pull(skb, len + 2)) 3120 return; /* too short */ 3121 dp += CCP_HDRLEN; 3122 len -= CCP_HDRLEN; 3123 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp)) 3124 break; 3125 if (inbound) { 3126 /* we will start receiving compressed packets */ 3127 if (!ppp->rc_state) 3128 break; 3129 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len, 3130 ppp->file.index, 0, ppp->mru, ppp->debug)) { 3131 ppp->rstate |= SC_DECOMP_RUN; 3132 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR); 3133 } 3134 } else { 3135 /* we will soon start sending compressed packets */ 3136 if (!ppp->xc_state) 3137 break; 3138 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len, 3139 ppp->file.index, 0, ppp->debug)) 3140 ppp->xstate |= SC_COMP_RUN; 3141 } 3142 break; 3143 3144 case CCP_RESETACK: 3145 /* reset the [de]compressor */ 3146 if ((ppp->flags & SC_CCP_UP) == 0) 3147 break; 3148 if (inbound) { 3149 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) { 3150 ppp->rcomp->decomp_reset(ppp->rc_state); 3151 ppp->rstate &= ~SC_DC_ERROR; 3152 } 3153 } else { 3154 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN)) 3155 ppp->xcomp->comp_reset(ppp->xc_state); 3156 } 3157 break; 3158 } 3159 } 3160 3161 /* Free up compression resources. */ 3162 static void 3163 ppp_ccp_closed(struct ppp *ppp) 3164 { 3165 void *xstate, *rstate; 3166 struct compressor *xcomp, *rcomp; 3167 3168 ppp_lock(ppp); 3169 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP); 3170 ppp->xstate = 0; 3171 xcomp = ppp->xcomp; 3172 xstate = ppp->xc_state; 3173 ppp->xc_state = NULL; 3174 ppp->rstate = 0; 3175 rcomp = ppp->rcomp; 3176 rstate = ppp->rc_state; 3177 ppp->rc_state = NULL; 3178 ppp_unlock(ppp); 3179 3180 if (xstate) { 3181 xcomp->comp_free(xstate); 3182 module_put(xcomp->owner); 3183 } 3184 if (rstate) { 3185 rcomp->decomp_free(rstate); 3186 module_put(rcomp->owner); 3187 } 3188 } 3189 3190 /* List of compressors. */ 3191 static LIST_HEAD(compressor_list); 3192 static DEFINE_SPINLOCK(compressor_list_lock); 3193 3194 struct compressor_entry { 3195 struct list_head list; 3196 struct compressor *comp; 3197 }; 3198 3199 static struct compressor_entry * 3200 find_comp_entry(int proto) 3201 { 3202 struct compressor_entry *ce; 3203 3204 list_for_each_entry(ce, &compressor_list, list) { 3205 if (ce->comp->compress_proto == proto) 3206 return ce; 3207 } 3208 return NULL; 3209 } 3210 3211 /* Register a compressor */ 3212 int 3213 ppp_register_compressor(struct compressor *cp) 3214 { 3215 struct compressor_entry *ce; 3216 int ret; 3217 spin_lock(&compressor_list_lock); 3218 ret = -EEXIST; 3219 if (find_comp_entry(cp->compress_proto)) 3220 goto out; 3221 ret = -ENOMEM; 3222 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC); 3223 if (!ce) 3224 goto out; 3225 ret = 0; 3226 ce->comp = cp; 3227 list_add(&ce->list, &compressor_list); 3228 out: 3229 spin_unlock(&compressor_list_lock); 3230 return ret; 3231 } 3232 3233 /* Unregister a compressor */ 3234 void 3235 ppp_unregister_compressor(struct compressor *cp) 3236 { 3237 struct compressor_entry *ce; 3238 3239 spin_lock(&compressor_list_lock); 3240 ce = find_comp_entry(cp->compress_proto); 3241 if (ce && ce->comp == cp) { 3242 list_del(&ce->list); 3243 kfree(ce); 3244 } 3245 spin_unlock(&compressor_list_lock); 3246 } 3247 3248 /* Find a compressor. */ 3249 static struct compressor * 3250 find_compressor(int type) 3251 { 3252 struct compressor_entry *ce; 3253 struct compressor *cp = NULL; 3254 3255 spin_lock(&compressor_list_lock); 3256 ce = find_comp_entry(type); 3257 if (ce) { 3258 cp = ce->comp; 3259 if (!try_module_get(cp->owner)) 3260 cp = NULL; 3261 } 3262 spin_unlock(&compressor_list_lock); 3263 return cp; 3264 } 3265 3266 /* 3267 * Miscelleneous stuff. 3268 */ 3269 3270 static void 3271 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st) 3272 { 3273 struct slcompress *vj = ppp->vj; 3274 3275 memset(st, 0, sizeof(*st)); 3276 st->p.ppp_ipackets = ppp->stats64.rx_packets; 3277 st->p.ppp_ierrors = ppp->dev->stats.rx_errors; 3278 st->p.ppp_ibytes = ppp->stats64.rx_bytes; 3279 st->p.ppp_opackets = ppp->stats64.tx_packets; 3280 st->p.ppp_oerrors = ppp->dev->stats.tx_errors; 3281 st->p.ppp_obytes = ppp->stats64.tx_bytes; 3282 if (!vj) 3283 return; 3284 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed; 3285 st->vj.vjs_compressed = vj->sls_o_compressed; 3286 st->vj.vjs_searches = vj->sls_o_searches; 3287 st->vj.vjs_misses = vj->sls_o_misses; 3288 st->vj.vjs_errorin = vj->sls_i_error; 3289 st->vj.vjs_tossed = vj->sls_i_tossed; 3290 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed; 3291 st->vj.vjs_compressedin = vj->sls_i_compressed; 3292 } 3293 3294 /* 3295 * Stuff for handling the lists of ppp units and channels 3296 * and for initialization. 3297 */ 3298 3299 /* 3300 * Create a new ppp interface unit. Fails if it can't allocate memory 3301 * or if there is already a unit with the requested number. 3302 * unit == -1 means allocate a new number. 3303 */ 3304 static int ppp_create_interface(struct net *net, struct file *file, int *unit) 3305 { 3306 struct ppp_config conf = { 3307 .file = file, 3308 .unit = *unit, 3309 .ifname_is_set = false, 3310 }; 3311 struct net_device *dev; 3312 struct ppp *ppp; 3313 int err; 3314 3315 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup); 3316 if (!dev) { 3317 err = -ENOMEM; 3318 goto err; 3319 } 3320 dev_net_set(dev, net); 3321 dev->rtnl_link_ops = &ppp_link_ops; 3322 3323 rtnl_lock(); 3324 3325 err = ppp_dev_configure(net, dev, &conf); 3326 if (err < 0) 3327 goto err_dev; 3328 ppp = netdev_priv(dev); 3329 *unit = ppp->file.index; 3330 3331 rtnl_unlock(); 3332 3333 return 0; 3334 3335 err_dev: 3336 rtnl_unlock(); 3337 free_netdev(dev); 3338 err: 3339 return err; 3340 } 3341 3342 /* 3343 * Initialize a ppp_file structure. 3344 */ 3345 static void 3346 init_ppp_file(struct ppp_file *pf, int kind) 3347 { 3348 pf->kind = kind; 3349 skb_queue_head_init(&pf->xq); 3350 skb_queue_head_init(&pf->rq); 3351 refcount_set(&pf->refcnt, 1); 3352 init_waitqueue_head(&pf->rwait); 3353 } 3354 3355 /* 3356 * Free the memory used by a ppp unit. This is only called once 3357 * there are no channels connected to the unit and no file structs 3358 * that reference the unit. 3359 */ 3360 static void ppp_destroy_interface(struct ppp *ppp) 3361 { 3362 atomic_dec(&ppp_unit_count); 3363 3364 if (!ppp->file.dead || ppp->n_channels) { 3365 /* "can't happen" */ 3366 netdev_err(ppp->dev, "ppp: destroying ppp struct %p " 3367 "but dead=%d n_channels=%d !\n", 3368 ppp, ppp->file.dead, ppp->n_channels); 3369 return; 3370 } 3371 3372 ppp_ccp_closed(ppp); 3373 if (ppp->vj) { 3374 slhc_free(ppp->vj); 3375 ppp->vj = NULL; 3376 } 3377 skb_queue_purge(&ppp->file.xq); 3378 skb_queue_purge(&ppp->file.rq); 3379 #ifdef CONFIG_PPP_MULTILINK 3380 skb_queue_purge(&ppp->mrq); 3381 #endif /* CONFIG_PPP_MULTILINK */ 3382 #ifdef CONFIG_PPP_FILTER 3383 if (ppp->pass_filter) { 3384 bpf_prog_destroy(ppp->pass_filter); 3385 ppp->pass_filter = NULL; 3386 } 3387 3388 if (ppp->active_filter) { 3389 bpf_prog_destroy(ppp->active_filter); 3390 ppp->active_filter = NULL; 3391 } 3392 #endif /* CONFIG_PPP_FILTER */ 3393 3394 kfree_skb(ppp->xmit_pending); 3395 free_percpu(ppp->xmit_recursion); 3396 3397 free_netdev(ppp->dev); 3398 } 3399 3400 /* 3401 * Locate an existing ppp unit. 3402 * The caller should have locked the all_ppp_mutex. 3403 */ 3404 static struct ppp * 3405 ppp_find_unit(struct ppp_net *pn, int unit) 3406 { 3407 return unit_find(&pn->units_idr, unit); 3408 } 3409 3410 /* 3411 * Locate an existing ppp channel. 3412 * The caller should have locked the all_channels_lock. 3413 * First we look in the new_channels list, then in the 3414 * all_channels list. If found in the new_channels list, 3415 * we move it to the all_channels list. This is for speed 3416 * when we have a lot of channels in use. 3417 */ 3418 static struct channel * 3419 ppp_find_channel(struct ppp_net *pn, int unit) 3420 { 3421 struct channel *pch; 3422 3423 list_for_each_entry(pch, &pn->new_channels, list) { 3424 if (pch->file.index == unit) { 3425 list_move(&pch->list, &pn->all_channels); 3426 return pch; 3427 } 3428 } 3429 3430 list_for_each_entry(pch, &pn->all_channels, list) { 3431 if (pch->file.index == unit) 3432 return pch; 3433 } 3434 3435 return NULL; 3436 } 3437 3438 /* 3439 * Connect a PPP channel to a PPP interface unit. 3440 */ 3441 static int 3442 ppp_connect_channel(struct channel *pch, int unit) 3443 { 3444 struct ppp *ppp; 3445 struct ppp_net *pn; 3446 int ret = -ENXIO; 3447 int hdrlen; 3448 3449 pn = ppp_pernet(pch->chan_net); 3450 3451 mutex_lock(&pn->all_ppp_mutex); 3452 ppp = ppp_find_unit(pn, unit); 3453 if (!ppp) 3454 goto out; 3455 write_lock_bh(&pch->upl); 3456 ret = -EINVAL; 3457 if (pch->ppp || 3458 rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl))) 3459 goto outl; 3460 3461 ppp_lock(ppp); 3462 spin_lock_bh(&pch->downl); 3463 if (!pch->chan) { 3464 /* Don't connect unregistered channels */ 3465 spin_unlock_bh(&pch->downl); 3466 ppp_unlock(ppp); 3467 ret = -ENOTCONN; 3468 goto outl; 3469 } 3470 spin_unlock_bh(&pch->downl); 3471 if (pch->file.hdrlen > ppp->file.hdrlen) 3472 ppp->file.hdrlen = pch->file.hdrlen; 3473 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */ 3474 if (hdrlen > ppp->dev->hard_header_len) 3475 ppp->dev->hard_header_len = hdrlen; 3476 list_add_tail(&pch->clist, &ppp->channels); 3477 ++ppp->n_channels; 3478 pch->ppp = ppp; 3479 refcount_inc(&ppp->file.refcnt); 3480 ppp_unlock(ppp); 3481 ret = 0; 3482 3483 outl: 3484 write_unlock_bh(&pch->upl); 3485 out: 3486 mutex_unlock(&pn->all_ppp_mutex); 3487 return ret; 3488 } 3489 3490 /* 3491 * Disconnect a channel from its ppp unit. 3492 */ 3493 static int 3494 ppp_disconnect_channel(struct channel *pch) 3495 { 3496 struct ppp *ppp; 3497 int err = -EINVAL; 3498 3499 write_lock_bh(&pch->upl); 3500 ppp = pch->ppp; 3501 pch->ppp = NULL; 3502 write_unlock_bh(&pch->upl); 3503 if (ppp) { 3504 /* remove it from the ppp unit's list */ 3505 ppp_lock(ppp); 3506 list_del(&pch->clist); 3507 if (--ppp->n_channels == 0) 3508 wake_up_interruptible(&ppp->file.rwait); 3509 ppp_unlock(ppp); 3510 if (refcount_dec_and_test(&ppp->file.refcnt)) 3511 ppp_destroy_interface(ppp); 3512 err = 0; 3513 } 3514 return err; 3515 } 3516 3517 /* 3518 * Free up the resources used by a ppp channel. 3519 */ 3520 static void ppp_destroy_channel(struct channel *pch) 3521 { 3522 put_net(pch->chan_net); 3523 pch->chan_net = NULL; 3524 3525 atomic_dec(&channel_count); 3526 3527 if (!pch->file.dead) { 3528 /* "can't happen" */ 3529 pr_err("ppp: destroying undead channel %p !\n", pch); 3530 return; 3531 } 3532 skb_queue_purge(&pch->file.xq); 3533 skb_queue_purge(&pch->file.rq); 3534 kfree(pch); 3535 } 3536 3537 static void __exit ppp_cleanup(void) 3538 { 3539 /* should never happen */ 3540 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count)) 3541 pr_err("PPP: removing module but units remain!\n"); 3542 rtnl_link_unregister(&ppp_link_ops); 3543 unregister_chrdev(PPP_MAJOR, "ppp"); 3544 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0)); 3545 class_destroy(ppp_class); 3546 unregister_pernet_device(&ppp_net_ops); 3547 } 3548 3549 /* 3550 * Units handling. Caller must protect concurrent access 3551 * by holding all_ppp_mutex 3552 */ 3553 3554 /* associate pointer with specified number */ 3555 static int unit_set(struct idr *p, void *ptr, int n) 3556 { 3557 int unit; 3558 3559 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL); 3560 if (unit == -ENOSPC) 3561 unit = -EINVAL; 3562 return unit; 3563 } 3564 3565 /* get new free unit number and associate pointer with it */ 3566 static int unit_get(struct idr *p, void *ptr, int min) 3567 { 3568 return idr_alloc(p, ptr, min, 0, GFP_KERNEL); 3569 } 3570 3571 /* put unit number back to a pool */ 3572 static void unit_put(struct idr *p, int n) 3573 { 3574 idr_remove(p, n); 3575 } 3576 3577 /* get pointer associated with the number */ 3578 static void *unit_find(struct idr *p, int n) 3579 { 3580 return idr_find(p, n); 3581 } 3582 3583 /* Module/initialization stuff */ 3584 3585 module_init(ppp_init); 3586 module_exit(ppp_cleanup); 3587 3588 EXPORT_SYMBOL(ppp_register_net_channel); 3589 EXPORT_SYMBOL(ppp_register_channel); 3590 EXPORT_SYMBOL(ppp_unregister_channel); 3591 EXPORT_SYMBOL(ppp_channel_index); 3592 EXPORT_SYMBOL(ppp_unit_number); 3593 EXPORT_SYMBOL(ppp_dev_name); 3594 EXPORT_SYMBOL(ppp_input); 3595 EXPORT_SYMBOL(ppp_input_error); 3596 EXPORT_SYMBOL(ppp_output_wakeup); 3597 EXPORT_SYMBOL(ppp_register_compressor); 3598 EXPORT_SYMBOL(ppp_unregister_compressor); 3599 MODULE_LICENSE("GPL"); 3600 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0); 3601 MODULE_ALIAS_RTNL_LINK("ppp"); 3602 MODULE_ALIAS("devname:ppp"); 3603