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 #define PPP_PROTO_LEN 2 73 74 /* 75 * An instance of /dev/ppp can be associated with either a ppp 76 * interface unit or a ppp channel. In both cases, file->private_data 77 * points to one of these. 78 */ 79 struct ppp_file { 80 enum { 81 INTERFACE=1, CHANNEL 82 } kind; 83 struct sk_buff_head xq; /* pppd transmit queue */ 84 struct sk_buff_head rq; /* receive queue for pppd */ 85 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */ 86 refcount_t refcnt; /* # refs (incl /dev/ppp attached) */ 87 int hdrlen; /* space to leave for headers */ 88 int index; /* interface unit / channel number */ 89 int dead; /* unit/channel has been shut down */ 90 }; 91 92 #define PF_TO_X(pf, X) container_of(pf, X, file) 93 94 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp) 95 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel) 96 97 /* 98 * Data structure to hold primary network stats for which 99 * we want to use 64 bit storage. Other network stats 100 * are stored in dev->stats of the ppp strucute. 101 */ 102 struct ppp_link_stats { 103 u64 rx_packets; 104 u64 tx_packets; 105 u64 rx_bytes; 106 u64 tx_bytes; 107 }; 108 109 /* 110 * Data structure describing one ppp unit. 111 * A ppp unit corresponds to a ppp network interface device 112 * and represents a multilink bundle. 113 * It can have 0 or more ppp channels connected to it. 114 */ 115 struct ppp { 116 struct ppp_file file; /* stuff for read/write/poll 0 */ 117 struct file *owner; /* file that owns this unit 48 */ 118 struct list_head channels; /* list of attached channels 4c */ 119 int n_channels; /* how many channels are attached 54 */ 120 spinlock_t rlock; /* lock for receive side 58 */ 121 spinlock_t wlock; /* lock for transmit side 5c */ 122 int __percpu *xmit_recursion; /* xmit recursion detect */ 123 int mru; /* max receive unit 60 */ 124 unsigned int flags; /* control bits 64 */ 125 unsigned int xstate; /* transmit state bits 68 */ 126 unsigned int rstate; /* receive state bits 6c */ 127 int debug; /* debug flags 70 */ 128 struct slcompress *vj; /* state for VJ header compression */ 129 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */ 130 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */ 131 struct compressor *xcomp; /* transmit packet compressor 8c */ 132 void *xc_state; /* its internal state 90 */ 133 struct compressor *rcomp; /* receive decompressor 94 */ 134 void *rc_state; /* its internal state 98 */ 135 unsigned long last_xmit; /* jiffies when last pkt sent 9c */ 136 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */ 137 struct net_device *dev; /* network interface device a4 */ 138 int closing; /* is device closing down? a8 */ 139 #ifdef CONFIG_PPP_MULTILINK 140 int nxchan; /* next channel to send something on */ 141 u32 nxseq; /* next sequence number to send */ 142 int mrru; /* MP: max reconst. receive unit */ 143 u32 nextseq; /* MP: seq no of next packet */ 144 u32 minseq; /* MP: min of most recent seqnos */ 145 struct sk_buff_head mrq; /* MP: receive reconstruction queue */ 146 #endif /* CONFIG_PPP_MULTILINK */ 147 #ifdef CONFIG_PPP_FILTER 148 struct bpf_prog *pass_filter; /* filter for packets to pass */ 149 struct bpf_prog *active_filter; /* filter for pkts to reset idle */ 150 #endif /* CONFIG_PPP_FILTER */ 151 struct net *ppp_net; /* the net we belong to */ 152 struct ppp_link_stats stats64; /* 64 bit network stats */ 153 }; 154 155 /* 156 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC, 157 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP, 158 * SC_MUST_COMP 159 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR. 160 * Bits in xstate: SC_COMP_RUN 161 */ 162 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \ 163 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \ 164 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP) 165 166 /* 167 * Private data structure for each channel. 168 * This includes the data structure used for multilink. 169 */ 170 struct channel { 171 struct ppp_file file; /* stuff for read/write/poll */ 172 struct list_head list; /* link in all/new_channels list */ 173 struct ppp_channel *chan; /* public channel data structure */ 174 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */ 175 spinlock_t downl; /* protects `chan', file.xq dequeue */ 176 struct ppp *ppp; /* ppp unit we're connected to */ 177 struct net *chan_net; /* the net channel belongs to */ 178 netns_tracker ns_tracker; 179 struct list_head clist; /* link in list of channels per unit */ 180 rwlock_t upl; /* protects `ppp' and 'bridge' */ 181 struct channel __rcu *bridge; /* "bridged" ppp channel */ 182 #ifdef CONFIG_PPP_MULTILINK 183 u8 avail; /* flag used in multilink stuff */ 184 u8 had_frag; /* >= 1 fragments have been sent */ 185 u32 lastseq; /* MP: last sequence # received */ 186 int speed; /* speed of the corresponding ppp channel*/ 187 #endif /* CONFIG_PPP_MULTILINK */ 188 }; 189 190 struct ppp_config { 191 struct file *file; 192 s32 unit; 193 bool ifname_is_set; 194 }; 195 196 /* 197 * SMP locking issues: 198 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels 199 * list and the ppp.n_channels field, you need to take both locks 200 * before you modify them. 201 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock -> 202 * channel.downl. 203 */ 204 205 static DEFINE_MUTEX(ppp_mutex); 206 static atomic_t ppp_unit_count = ATOMIC_INIT(0); 207 static atomic_t channel_count = ATOMIC_INIT(0); 208 209 /* per-net private data for this module */ 210 static unsigned int ppp_net_id __read_mostly; 211 struct ppp_net { 212 /* units to ppp mapping */ 213 struct idr units_idr; 214 215 /* 216 * all_ppp_mutex protects the units_idr mapping. 217 * It also ensures that finding a ppp unit in the units_idr 218 * map and updating its file.refcnt field is atomic. 219 */ 220 struct mutex all_ppp_mutex; 221 222 /* channels */ 223 struct list_head all_channels; 224 struct list_head new_channels; 225 int last_channel_index; 226 227 /* 228 * all_channels_lock protects all_channels and 229 * last_channel_index, and the atomicity of find 230 * a channel and updating its file.refcnt field. 231 */ 232 spinlock_t all_channels_lock; 233 }; 234 235 /* Get the PPP protocol number from a skb */ 236 #define PPP_PROTO(skb) get_unaligned_be16((skb)->data) 237 238 /* We limit the length of ppp->file.rq to this (arbitrary) value */ 239 #define PPP_MAX_RQLEN 32 240 241 /* 242 * Maximum number of multilink fragments queued up. 243 * This has to be large enough to cope with the maximum latency of 244 * the slowest channel relative to the others. Strictly it should 245 * depend on the number of channels and their characteristics. 246 */ 247 #define PPP_MP_MAX_QLEN 128 248 249 /* Multilink header bits. */ 250 #define B 0x80 /* this fragment begins a packet */ 251 #define E 0x40 /* this fragment ends a packet */ 252 253 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */ 254 #define seq_before(a, b) ((s32)((a) - (b)) < 0) 255 #define seq_after(a, b) ((s32)((a) - (b)) > 0) 256 257 /* Prototypes. */ 258 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 259 struct file *file, unsigned int cmd, unsigned long arg); 260 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb); 261 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb); 262 static void ppp_push(struct ppp *ppp); 263 static void ppp_channel_push(struct channel *pch); 264 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, 265 struct channel *pch); 266 static void ppp_receive_error(struct ppp *ppp); 267 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb); 268 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp, 269 struct sk_buff *skb); 270 #ifdef CONFIG_PPP_MULTILINK 271 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, 272 struct channel *pch); 273 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb); 274 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp); 275 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb); 276 #endif /* CONFIG_PPP_MULTILINK */ 277 static int ppp_set_compress(struct ppp *ppp, struct ppp_option_data *data); 278 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound); 279 static void ppp_ccp_closed(struct ppp *ppp); 280 static struct compressor *find_compressor(int type); 281 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st); 282 static int ppp_create_interface(struct net *net, struct file *file, int *unit); 283 static void init_ppp_file(struct ppp_file *pf, int kind); 284 static void ppp_destroy_interface(struct ppp *ppp); 285 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit); 286 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit); 287 static int ppp_connect_channel(struct channel *pch, int unit); 288 static int ppp_disconnect_channel(struct channel *pch); 289 static void ppp_destroy_channel(struct channel *pch); 290 static int unit_get(struct idr *p, void *ptr, int min); 291 static int unit_set(struct idr *p, void *ptr, int n); 292 static void unit_put(struct idr *p, int n); 293 static void *unit_find(struct idr *p, int n); 294 static void ppp_setup(struct net_device *dev); 295 296 static const struct net_device_ops ppp_netdev_ops; 297 298 static struct class *ppp_class; 299 300 /* per net-namespace data */ 301 static inline struct ppp_net *ppp_pernet(struct net *net) 302 { 303 return net_generic(net, ppp_net_id); 304 } 305 306 /* Translates a PPP protocol number to a NP index (NP == network protocol) */ 307 static inline int proto_to_npindex(int proto) 308 { 309 switch (proto) { 310 case PPP_IP: 311 return NP_IP; 312 case PPP_IPV6: 313 return NP_IPV6; 314 case PPP_IPX: 315 return NP_IPX; 316 case PPP_AT: 317 return NP_AT; 318 case PPP_MPLS_UC: 319 return NP_MPLS_UC; 320 case PPP_MPLS_MC: 321 return NP_MPLS_MC; 322 } 323 return -EINVAL; 324 } 325 326 /* Translates an NP index into a PPP protocol number */ 327 static const int npindex_to_proto[NUM_NP] = { 328 PPP_IP, 329 PPP_IPV6, 330 PPP_IPX, 331 PPP_AT, 332 PPP_MPLS_UC, 333 PPP_MPLS_MC, 334 }; 335 336 /* Translates an ethertype into an NP index */ 337 static inline int ethertype_to_npindex(int ethertype) 338 { 339 switch (ethertype) { 340 case ETH_P_IP: 341 return NP_IP; 342 case ETH_P_IPV6: 343 return NP_IPV6; 344 case ETH_P_IPX: 345 return NP_IPX; 346 case ETH_P_PPPTALK: 347 case ETH_P_ATALK: 348 return NP_AT; 349 case ETH_P_MPLS_UC: 350 return NP_MPLS_UC; 351 case ETH_P_MPLS_MC: 352 return NP_MPLS_MC; 353 } 354 return -1; 355 } 356 357 /* Translates an NP index into an ethertype */ 358 static const int npindex_to_ethertype[NUM_NP] = { 359 ETH_P_IP, 360 ETH_P_IPV6, 361 ETH_P_IPX, 362 ETH_P_PPPTALK, 363 ETH_P_MPLS_UC, 364 ETH_P_MPLS_MC, 365 }; 366 367 /* 368 * Locking shorthand. 369 */ 370 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock) 371 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock) 372 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock) 373 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock) 374 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \ 375 ppp_recv_lock(ppp); } while (0) 376 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \ 377 ppp_xmit_unlock(ppp); } while (0) 378 379 /* 380 * /dev/ppp device routines. 381 * The /dev/ppp device is used by pppd to control the ppp unit. 382 * It supports the read, write, ioctl and poll functions. 383 * Open instances of /dev/ppp can be in one of three states: 384 * unattached, attached to a ppp unit, or attached to a ppp channel. 385 */ 386 static int ppp_open(struct inode *inode, struct file *file) 387 { 388 /* 389 * This could (should?) be enforced by the permissions on /dev/ppp. 390 */ 391 if (!ns_capable(file->f_cred->user_ns, CAP_NET_ADMIN)) 392 return -EPERM; 393 return 0; 394 } 395 396 static int ppp_release(struct inode *unused, struct file *file) 397 { 398 struct ppp_file *pf = file->private_data; 399 struct ppp *ppp; 400 401 if (pf) { 402 file->private_data = NULL; 403 if (pf->kind == INTERFACE) { 404 ppp = PF_TO_PPP(pf); 405 rtnl_lock(); 406 if (file == ppp->owner) 407 unregister_netdevice(ppp->dev); 408 rtnl_unlock(); 409 } 410 if (refcount_dec_and_test(&pf->refcnt)) { 411 switch (pf->kind) { 412 case INTERFACE: 413 ppp_destroy_interface(PF_TO_PPP(pf)); 414 break; 415 case CHANNEL: 416 ppp_destroy_channel(PF_TO_CHANNEL(pf)); 417 break; 418 } 419 } 420 } 421 return 0; 422 } 423 424 static ssize_t ppp_read(struct file *file, char __user *buf, 425 size_t count, loff_t *ppos) 426 { 427 struct ppp_file *pf = file->private_data; 428 DECLARE_WAITQUEUE(wait, current); 429 ssize_t ret; 430 struct sk_buff *skb = NULL; 431 struct iovec iov; 432 struct iov_iter to; 433 434 ret = count; 435 436 if (!pf) 437 return -ENXIO; 438 add_wait_queue(&pf->rwait, &wait); 439 for (;;) { 440 set_current_state(TASK_INTERRUPTIBLE); 441 skb = skb_dequeue(&pf->rq); 442 if (skb) 443 break; 444 ret = 0; 445 if (pf->dead) 446 break; 447 if (pf->kind == INTERFACE) { 448 /* 449 * Return 0 (EOF) on an interface that has no 450 * channels connected, unless it is looping 451 * network traffic (demand mode). 452 */ 453 struct ppp *ppp = PF_TO_PPP(pf); 454 455 ppp_recv_lock(ppp); 456 if (ppp->n_channels == 0 && 457 (ppp->flags & SC_LOOP_TRAFFIC) == 0) { 458 ppp_recv_unlock(ppp); 459 break; 460 } 461 ppp_recv_unlock(ppp); 462 } 463 ret = -EAGAIN; 464 if (file->f_flags & O_NONBLOCK) 465 break; 466 ret = -ERESTARTSYS; 467 if (signal_pending(current)) 468 break; 469 schedule(); 470 } 471 set_current_state(TASK_RUNNING); 472 remove_wait_queue(&pf->rwait, &wait); 473 474 if (!skb) 475 goto out; 476 477 ret = -EOVERFLOW; 478 if (skb->len > count) 479 goto outf; 480 ret = -EFAULT; 481 iov.iov_base = buf; 482 iov.iov_len = count; 483 iov_iter_init(&to, READ, &iov, 1, count); 484 if (skb_copy_datagram_iter(skb, 0, &to, skb->len)) 485 goto outf; 486 ret = skb->len; 487 488 outf: 489 kfree_skb(skb); 490 out: 491 return ret; 492 } 493 494 static ssize_t ppp_write(struct file *file, const char __user *buf, 495 size_t count, loff_t *ppos) 496 { 497 struct ppp_file *pf = file->private_data; 498 struct sk_buff *skb; 499 ssize_t ret; 500 501 if (!pf) 502 return -ENXIO; 503 /* All PPP packets should start with the 2-byte protocol */ 504 if (count < PPP_PROTO_LEN) 505 return -EINVAL; 506 ret = -ENOMEM; 507 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL); 508 if (!skb) 509 goto out; 510 skb_reserve(skb, pf->hdrlen); 511 ret = -EFAULT; 512 if (copy_from_user(skb_put(skb, count), buf, count)) { 513 kfree_skb(skb); 514 goto out; 515 } 516 517 switch (pf->kind) { 518 case INTERFACE: 519 ppp_xmit_process(PF_TO_PPP(pf), skb); 520 break; 521 case CHANNEL: 522 skb_queue_tail(&pf->xq, skb); 523 ppp_channel_push(PF_TO_CHANNEL(pf)); 524 break; 525 } 526 527 ret = count; 528 529 out: 530 return ret; 531 } 532 533 /* No kernel lock - fine */ 534 static __poll_t ppp_poll(struct file *file, poll_table *wait) 535 { 536 struct ppp_file *pf = file->private_data; 537 __poll_t mask; 538 539 if (!pf) 540 return 0; 541 poll_wait(file, &pf->rwait, wait); 542 mask = EPOLLOUT | EPOLLWRNORM; 543 if (skb_peek(&pf->rq)) 544 mask |= EPOLLIN | EPOLLRDNORM; 545 if (pf->dead) 546 mask |= EPOLLHUP; 547 else if (pf->kind == INTERFACE) { 548 /* see comment in ppp_read */ 549 struct ppp *ppp = PF_TO_PPP(pf); 550 551 ppp_recv_lock(ppp); 552 if (ppp->n_channels == 0 && 553 (ppp->flags & SC_LOOP_TRAFFIC) == 0) 554 mask |= EPOLLIN | EPOLLRDNORM; 555 ppp_recv_unlock(ppp); 556 } 557 558 return mask; 559 } 560 561 #ifdef CONFIG_PPP_FILTER 562 static struct bpf_prog *get_filter(struct sock_fprog *uprog) 563 { 564 struct sock_fprog_kern fprog; 565 struct bpf_prog *res = NULL; 566 int err; 567 568 if (!uprog->len) 569 return NULL; 570 571 /* uprog->len is unsigned short, so no overflow here */ 572 fprog.len = uprog->len; 573 fprog.filter = memdup_user(uprog->filter, 574 uprog->len * sizeof(struct sock_filter)); 575 if (IS_ERR(fprog.filter)) 576 return ERR_CAST(fprog.filter); 577 578 err = bpf_prog_create(&res, &fprog); 579 kfree(fprog.filter); 580 581 return err ? ERR_PTR(err) : res; 582 } 583 584 static struct bpf_prog *ppp_get_filter(struct sock_fprog __user *p) 585 { 586 struct sock_fprog uprog; 587 588 if (copy_from_user(&uprog, p, sizeof(struct sock_fprog))) 589 return ERR_PTR(-EFAULT); 590 return get_filter(&uprog); 591 } 592 593 #ifdef CONFIG_COMPAT 594 struct sock_fprog32 { 595 unsigned short len; 596 compat_caddr_t filter; 597 }; 598 599 #define PPPIOCSPASS32 _IOW('t', 71, struct sock_fprog32) 600 #define PPPIOCSACTIVE32 _IOW('t', 70, struct sock_fprog32) 601 602 static struct bpf_prog *compat_ppp_get_filter(struct sock_fprog32 __user *p) 603 { 604 struct sock_fprog32 uprog32; 605 struct sock_fprog uprog; 606 607 if (copy_from_user(&uprog32, p, sizeof(struct sock_fprog32))) 608 return ERR_PTR(-EFAULT); 609 uprog.len = uprog32.len; 610 uprog.filter = compat_ptr(uprog32.filter); 611 return get_filter(&uprog); 612 } 613 #endif 614 #endif 615 616 /* Bridge one PPP channel to another. 617 * When two channels are bridged, ppp_input on one channel is redirected to 618 * the other's ops->start_xmit handler. 619 * In order to safely bridge channels we must reject channels which are already 620 * part of a bridge instance, or which form part of an existing unit. 621 * Once successfully bridged, each channel holds a reference on the other 622 * to prevent it being freed while the bridge is extant. 623 */ 624 static int ppp_bridge_channels(struct channel *pch, struct channel *pchb) 625 { 626 write_lock_bh(&pch->upl); 627 if (pch->ppp || 628 rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl))) { 629 write_unlock_bh(&pch->upl); 630 return -EALREADY; 631 } 632 refcount_inc(&pchb->file.refcnt); 633 rcu_assign_pointer(pch->bridge, pchb); 634 write_unlock_bh(&pch->upl); 635 636 write_lock_bh(&pchb->upl); 637 if (pchb->ppp || 638 rcu_dereference_protected(pchb->bridge, lockdep_is_held(&pchb->upl))) { 639 write_unlock_bh(&pchb->upl); 640 goto err_unset; 641 } 642 refcount_inc(&pch->file.refcnt); 643 rcu_assign_pointer(pchb->bridge, pch); 644 write_unlock_bh(&pchb->upl); 645 646 return 0; 647 648 err_unset: 649 write_lock_bh(&pch->upl); 650 /* Re-read pch->bridge with upl held in case it was modified concurrently */ 651 pchb = rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl)); 652 RCU_INIT_POINTER(pch->bridge, NULL); 653 write_unlock_bh(&pch->upl); 654 synchronize_rcu(); 655 656 if (pchb) 657 if (refcount_dec_and_test(&pchb->file.refcnt)) 658 ppp_destroy_channel(pchb); 659 660 return -EALREADY; 661 } 662 663 static int ppp_unbridge_channels(struct channel *pch) 664 { 665 struct channel *pchb, *pchbb; 666 667 write_lock_bh(&pch->upl); 668 pchb = rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl)); 669 if (!pchb) { 670 write_unlock_bh(&pch->upl); 671 return -EINVAL; 672 } 673 RCU_INIT_POINTER(pch->bridge, NULL); 674 write_unlock_bh(&pch->upl); 675 676 /* Only modify pchb if phcb->bridge points back to pch. 677 * If not, it implies that there has been a race unbridging (and possibly 678 * even rebridging) pchb. We should leave pchb alone to avoid either a 679 * refcount underflow, or breaking another established bridge instance. 680 */ 681 write_lock_bh(&pchb->upl); 682 pchbb = rcu_dereference_protected(pchb->bridge, lockdep_is_held(&pchb->upl)); 683 if (pchbb == pch) 684 RCU_INIT_POINTER(pchb->bridge, NULL); 685 write_unlock_bh(&pchb->upl); 686 687 synchronize_rcu(); 688 689 if (pchbb == pch) 690 if (refcount_dec_and_test(&pch->file.refcnt)) 691 ppp_destroy_channel(pch); 692 693 if (refcount_dec_and_test(&pchb->file.refcnt)) 694 ppp_destroy_channel(pchb); 695 696 return 0; 697 } 698 699 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 700 { 701 struct ppp_file *pf; 702 struct ppp *ppp; 703 int err = -EFAULT, val, val2, i; 704 struct ppp_idle32 idle32; 705 struct ppp_idle64 idle64; 706 struct npioctl npi; 707 int unit, cflags; 708 struct slcompress *vj; 709 void __user *argp = (void __user *)arg; 710 int __user *p = argp; 711 712 mutex_lock(&ppp_mutex); 713 714 pf = file->private_data; 715 if (!pf) { 716 err = ppp_unattached_ioctl(current->nsproxy->net_ns, 717 pf, file, cmd, arg); 718 goto out; 719 } 720 721 if (cmd == PPPIOCDETACH) { 722 /* 723 * PPPIOCDETACH is no longer supported as it was heavily broken, 724 * and is only known to have been used by pppd older than 725 * ppp-2.4.2 (released November 2003). 726 */ 727 pr_warn_once("%s (%d) used obsolete PPPIOCDETACH ioctl\n", 728 current->comm, current->pid); 729 err = -EINVAL; 730 goto out; 731 } 732 733 if (pf->kind == CHANNEL) { 734 struct channel *pch, *pchb; 735 struct ppp_channel *chan; 736 struct ppp_net *pn; 737 738 pch = PF_TO_CHANNEL(pf); 739 740 switch (cmd) { 741 case PPPIOCCONNECT: 742 if (get_user(unit, p)) 743 break; 744 err = ppp_connect_channel(pch, unit); 745 break; 746 747 case PPPIOCDISCONN: 748 err = ppp_disconnect_channel(pch); 749 break; 750 751 case PPPIOCBRIDGECHAN: 752 if (get_user(unit, p)) 753 break; 754 err = -ENXIO; 755 pn = ppp_pernet(current->nsproxy->net_ns); 756 spin_lock_bh(&pn->all_channels_lock); 757 pchb = ppp_find_channel(pn, unit); 758 /* Hold a reference to prevent pchb being freed while 759 * we establish the bridge. 760 */ 761 if (pchb) 762 refcount_inc(&pchb->file.refcnt); 763 spin_unlock_bh(&pn->all_channels_lock); 764 if (!pchb) 765 break; 766 err = ppp_bridge_channels(pch, pchb); 767 /* Drop earlier refcount now bridge establishment is complete */ 768 if (refcount_dec_and_test(&pchb->file.refcnt)) 769 ppp_destroy_channel(pchb); 770 break; 771 772 case PPPIOCUNBRIDGECHAN: 773 err = ppp_unbridge_channels(pch); 774 break; 775 776 default: 777 down_read(&pch->chan_sem); 778 chan = pch->chan; 779 err = -ENOTTY; 780 if (chan && chan->ops->ioctl) 781 err = chan->ops->ioctl(chan, cmd, arg); 782 up_read(&pch->chan_sem); 783 } 784 goto out; 785 } 786 787 if (pf->kind != INTERFACE) { 788 /* can't happen */ 789 pr_err("PPP: not interface or channel??\n"); 790 err = -EINVAL; 791 goto out; 792 } 793 794 ppp = PF_TO_PPP(pf); 795 switch (cmd) { 796 case PPPIOCSMRU: 797 if (get_user(val, p)) 798 break; 799 ppp->mru = val; 800 err = 0; 801 break; 802 803 case PPPIOCSFLAGS: 804 if (get_user(val, p)) 805 break; 806 ppp_lock(ppp); 807 cflags = ppp->flags & ~val; 808 #ifdef CONFIG_PPP_MULTILINK 809 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK)) 810 ppp->nextseq = 0; 811 #endif 812 ppp->flags = val & SC_FLAG_BITS; 813 ppp_unlock(ppp); 814 if (cflags & SC_CCP_OPEN) 815 ppp_ccp_closed(ppp); 816 err = 0; 817 break; 818 819 case PPPIOCGFLAGS: 820 val = ppp->flags | ppp->xstate | ppp->rstate; 821 if (put_user(val, p)) 822 break; 823 err = 0; 824 break; 825 826 case PPPIOCSCOMPRESS: 827 { 828 struct ppp_option_data data; 829 if (copy_from_user(&data, argp, sizeof(data))) 830 err = -EFAULT; 831 else 832 err = ppp_set_compress(ppp, &data); 833 break; 834 } 835 case PPPIOCGUNIT: 836 if (put_user(ppp->file.index, p)) 837 break; 838 err = 0; 839 break; 840 841 case PPPIOCSDEBUG: 842 if (get_user(val, p)) 843 break; 844 ppp->debug = val; 845 err = 0; 846 break; 847 848 case PPPIOCGDEBUG: 849 if (put_user(ppp->debug, p)) 850 break; 851 err = 0; 852 break; 853 854 case PPPIOCGIDLE32: 855 idle32.xmit_idle = (jiffies - ppp->last_xmit) / HZ; 856 idle32.recv_idle = (jiffies - ppp->last_recv) / HZ; 857 if (copy_to_user(argp, &idle32, sizeof(idle32))) 858 break; 859 err = 0; 860 break; 861 862 case PPPIOCGIDLE64: 863 idle64.xmit_idle = (jiffies - ppp->last_xmit) / HZ; 864 idle64.recv_idle = (jiffies - ppp->last_recv) / HZ; 865 if (copy_to_user(argp, &idle64, sizeof(idle64))) 866 break; 867 err = 0; 868 break; 869 870 case PPPIOCSMAXCID: 871 if (get_user(val, p)) 872 break; 873 val2 = 15; 874 if ((val >> 16) != 0) { 875 val2 = val >> 16; 876 val &= 0xffff; 877 } 878 vj = slhc_init(val2+1, val+1); 879 if (IS_ERR(vj)) { 880 err = PTR_ERR(vj); 881 break; 882 } 883 ppp_lock(ppp); 884 if (ppp->vj) 885 slhc_free(ppp->vj); 886 ppp->vj = vj; 887 ppp_unlock(ppp); 888 err = 0; 889 break; 890 891 case PPPIOCGNPMODE: 892 case PPPIOCSNPMODE: 893 if (copy_from_user(&npi, argp, sizeof(npi))) 894 break; 895 err = proto_to_npindex(npi.protocol); 896 if (err < 0) 897 break; 898 i = err; 899 if (cmd == PPPIOCGNPMODE) { 900 err = -EFAULT; 901 npi.mode = ppp->npmode[i]; 902 if (copy_to_user(argp, &npi, sizeof(npi))) 903 break; 904 } else { 905 ppp->npmode[i] = npi.mode; 906 /* we may be able to transmit more packets now (??) */ 907 netif_wake_queue(ppp->dev); 908 } 909 err = 0; 910 break; 911 912 #ifdef CONFIG_PPP_FILTER 913 case PPPIOCSPASS: 914 case PPPIOCSACTIVE: 915 { 916 struct bpf_prog *filter = ppp_get_filter(argp); 917 struct bpf_prog **which; 918 919 if (IS_ERR(filter)) { 920 err = PTR_ERR(filter); 921 break; 922 } 923 if (cmd == PPPIOCSPASS) 924 which = &ppp->pass_filter; 925 else 926 which = &ppp->active_filter; 927 ppp_lock(ppp); 928 if (*which) 929 bpf_prog_destroy(*which); 930 *which = filter; 931 ppp_unlock(ppp); 932 err = 0; 933 break; 934 } 935 #endif /* CONFIG_PPP_FILTER */ 936 937 #ifdef CONFIG_PPP_MULTILINK 938 case PPPIOCSMRRU: 939 if (get_user(val, p)) 940 break; 941 ppp_recv_lock(ppp); 942 ppp->mrru = val; 943 ppp_recv_unlock(ppp); 944 err = 0; 945 break; 946 #endif /* CONFIG_PPP_MULTILINK */ 947 948 default: 949 err = -ENOTTY; 950 } 951 952 out: 953 mutex_unlock(&ppp_mutex); 954 955 return err; 956 } 957 958 #ifdef CONFIG_COMPAT 959 struct ppp_option_data32 { 960 compat_uptr_t ptr; 961 u32 length; 962 compat_int_t transmit; 963 }; 964 #define PPPIOCSCOMPRESS32 _IOW('t', 77, struct ppp_option_data32) 965 966 static long ppp_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 967 { 968 struct ppp_file *pf; 969 int err = -ENOIOCTLCMD; 970 void __user *argp = (void __user *)arg; 971 972 mutex_lock(&ppp_mutex); 973 974 pf = file->private_data; 975 if (pf && pf->kind == INTERFACE) { 976 struct ppp *ppp = PF_TO_PPP(pf); 977 switch (cmd) { 978 #ifdef CONFIG_PPP_FILTER 979 case PPPIOCSPASS32: 980 case PPPIOCSACTIVE32: 981 { 982 struct bpf_prog *filter = compat_ppp_get_filter(argp); 983 struct bpf_prog **which; 984 985 if (IS_ERR(filter)) { 986 err = PTR_ERR(filter); 987 break; 988 } 989 if (cmd == PPPIOCSPASS32) 990 which = &ppp->pass_filter; 991 else 992 which = &ppp->active_filter; 993 ppp_lock(ppp); 994 if (*which) 995 bpf_prog_destroy(*which); 996 *which = filter; 997 ppp_unlock(ppp); 998 err = 0; 999 break; 1000 } 1001 #endif /* CONFIG_PPP_FILTER */ 1002 case PPPIOCSCOMPRESS32: 1003 { 1004 struct ppp_option_data32 data32; 1005 if (copy_from_user(&data32, argp, sizeof(data32))) { 1006 err = -EFAULT; 1007 } else { 1008 struct ppp_option_data data = { 1009 .ptr = compat_ptr(data32.ptr), 1010 .length = data32.length, 1011 .transmit = data32.transmit 1012 }; 1013 err = ppp_set_compress(ppp, &data); 1014 } 1015 break; 1016 } 1017 } 1018 } 1019 mutex_unlock(&ppp_mutex); 1020 1021 /* all other commands have compatible arguments */ 1022 if (err == -ENOIOCTLCMD) 1023 err = ppp_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); 1024 1025 return err; 1026 } 1027 #endif 1028 1029 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 1030 struct file *file, unsigned int cmd, unsigned long arg) 1031 { 1032 int unit, err = -EFAULT; 1033 struct ppp *ppp; 1034 struct channel *chan; 1035 struct ppp_net *pn; 1036 int __user *p = (int __user *)arg; 1037 1038 switch (cmd) { 1039 case PPPIOCNEWUNIT: 1040 /* Create a new ppp unit */ 1041 if (get_user(unit, p)) 1042 break; 1043 err = ppp_create_interface(net, file, &unit); 1044 if (err < 0) 1045 break; 1046 1047 err = -EFAULT; 1048 if (put_user(unit, p)) 1049 break; 1050 err = 0; 1051 break; 1052 1053 case PPPIOCATTACH: 1054 /* Attach to an existing ppp unit */ 1055 if (get_user(unit, p)) 1056 break; 1057 err = -ENXIO; 1058 pn = ppp_pernet(net); 1059 mutex_lock(&pn->all_ppp_mutex); 1060 ppp = ppp_find_unit(pn, unit); 1061 if (ppp) { 1062 refcount_inc(&ppp->file.refcnt); 1063 file->private_data = &ppp->file; 1064 err = 0; 1065 } 1066 mutex_unlock(&pn->all_ppp_mutex); 1067 break; 1068 1069 case PPPIOCATTCHAN: 1070 if (get_user(unit, p)) 1071 break; 1072 err = -ENXIO; 1073 pn = ppp_pernet(net); 1074 spin_lock_bh(&pn->all_channels_lock); 1075 chan = ppp_find_channel(pn, unit); 1076 if (chan) { 1077 refcount_inc(&chan->file.refcnt); 1078 file->private_data = &chan->file; 1079 err = 0; 1080 } 1081 spin_unlock_bh(&pn->all_channels_lock); 1082 break; 1083 1084 default: 1085 err = -ENOTTY; 1086 } 1087 1088 return err; 1089 } 1090 1091 static const struct file_operations ppp_device_fops = { 1092 .owner = THIS_MODULE, 1093 .read = ppp_read, 1094 .write = ppp_write, 1095 .poll = ppp_poll, 1096 .unlocked_ioctl = ppp_ioctl, 1097 #ifdef CONFIG_COMPAT 1098 .compat_ioctl = ppp_compat_ioctl, 1099 #endif 1100 .open = ppp_open, 1101 .release = ppp_release, 1102 .llseek = noop_llseek, 1103 }; 1104 1105 static __net_init int ppp_init_net(struct net *net) 1106 { 1107 struct ppp_net *pn = net_generic(net, ppp_net_id); 1108 1109 idr_init(&pn->units_idr); 1110 mutex_init(&pn->all_ppp_mutex); 1111 1112 INIT_LIST_HEAD(&pn->all_channels); 1113 INIT_LIST_HEAD(&pn->new_channels); 1114 1115 spin_lock_init(&pn->all_channels_lock); 1116 1117 return 0; 1118 } 1119 1120 static __net_exit void ppp_exit_net(struct net *net) 1121 { 1122 struct ppp_net *pn = net_generic(net, ppp_net_id); 1123 struct net_device *dev; 1124 struct net_device *aux; 1125 struct ppp *ppp; 1126 LIST_HEAD(list); 1127 int id; 1128 1129 rtnl_lock(); 1130 for_each_netdev_safe(net, dev, aux) { 1131 if (dev->netdev_ops == &ppp_netdev_ops) 1132 unregister_netdevice_queue(dev, &list); 1133 } 1134 1135 idr_for_each_entry(&pn->units_idr, ppp, id) 1136 /* Skip devices already unregistered by previous loop */ 1137 if (!net_eq(dev_net(ppp->dev), net)) 1138 unregister_netdevice_queue(ppp->dev, &list); 1139 1140 unregister_netdevice_many(&list); 1141 rtnl_unlock(); 1142 1143 mutex_destroy(&pn->all_ppp_mutex); 1144 idr_destroy(&pn->units_idr); 1145 WARN_ON_ONCE(!list_empty(&pn->all_channels)); 1146 WARN_ON_ONCE(!list_empty(&pn->new_channels)); 1147 } 1148 1149 static struct pernet_operations ppp_net_ops = { 1150 .init = ppp_init_net, 1151 .exit = ppp_exit_net, 1152 .id = &ppp_net_id, 1153 .size = sizeof(struct ppp_net), 1154 }; 1155 1156 static int ppp_unit_register(struct ppp *ppp, int unit, bool ifname_is_set) 1157 { 1158 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 1159 int ret; 1160 1161 mutex_lock(&pn->all_ppp_mutex); 1162 1163 if (unit < 0) { 1164 ret = unit_get(&pn->units_idr, ppp, 0); 1165 if (ret < 0) 1166 goto err; 1167 if (!ifname_is_set) { 1168 while (1) { 1169 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ret); 1170 if (!netdev_name_in_use(ppp->ppp_net, ppp->dev->name)) 1171 break; 1172 unit_put(&pn->units_idr, ret); 1173 ret = unit_get(&pn->units_idr, ppp, ret + 1); 1174 if (ret < 0) 1175 goto err; 1176 } 1177 } 1178 } else { 1179 /* Caller asked for a specific unit number. Fail with -EEXIST 1180 * if unavailable. For backward compatibility, return -EEXIST 1181 * too if idr allocation fails; this makes pppd retry without 1182 * requesting a specific unit number. 1183 */ 1184 if (unit_find(&pn->units_idr, unit)) { 1185 ret = -EEXIST; 1186 goto err; 1187 } 1188 ret = unit_set(&pn->units_idr, ppp, unit); 1189 if (ret < 0) { 1190 /* Rewrite error for backward compatibility */ 1191 ret = -EEXIST; 1192 goto err; 1193 } 1194 } 1195 ppp->file.index = ret; 1196 1197 if (!ifname_is_set) 1198 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ppp->file.index); 1199 1200 mutex_unlock(&pn->all_ppp_mutex); 1201 1202 ret = register_netdevice(ppp->dev); 1203 if (ret < 0) 1204 goto err_unit; 1205 1206 atomic_inc(&ppp_unit_count); 1207 1208 return 0; 1209 1210 err_unit: 1211 mutex_lock(&pn->all_ppp_mutex); 1212 unit_put(&pn->units_idr, ppp->file.index); 1213 err: 1214 mutex_unlock(&pn->all_ppp_mutex); 1215 1216 return ret; 1217 } 1218 1219 static int ppp_dev_configure(struct net *src_net, struct net_device *dev, 1220 const struct ppp_config *conf) 1221 { 1222 struct ppp *ppp = netdev_priv(dev); 1223 int indx; 1224 int err; 1225 int cpu; 1226 1227 ppp->dev = dev; 1228 ppp->ppp_net = src_net; 1229 ppp->mru = PPP_MRU; 1230 ppp->owner = conf->file; 1231 1232 init_ppp_file(&ppp->file, INTERFACE); 1233 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */ 1234 1235 for (indx = 0; indx < NUM_NP; ++indx) 1236 ppp->npmode[indx] = NPMODE_PASS; 1237 INIT_LIST_HEAD(&ppp->channels); 1238 spin_lock_init(&ppp->rlock); 1239 spin_lock_init(&ppp->wlock); 1240 1241 ppp->xmit_recursion = alloc_percpu(int); 1242 if (!ppp->xmit_recursion) { 1243 err = -ENOMEM; 1244 goto err1; 1245 } 1246 for_each_possible_cpu(cpu) 1247 (*per_cpu_ptr(ppp->xmit_recursion, cpu)) = 0; 1248 1249 #ifdef CONFIG_PPP_MULTILINK 1250 ppp->minseq = -1; 1251 skb_queue_head_init(&ppp->mrq); 1252 #endif /* CONFIG_PPP_MULTILINK */ 1253 #ifdef CONFIG_PPP_FILTER 1254 ppp->pass_filter = NULL; 1255 ppp->active_filter = NULL; 1256 #endif /* CONFIG_PPP_FILTER */ 1257 1258 err = ppp_unit_register(ppp, conf->unit, conf->ifname_is_set); 1259 if (err < 0) 1260 goto err2; 1261 1262 conf->file->private_data = &ppp->file; 1263 1264 return 0; 1265 err2: 1266 free_percpu(ppp->xmit_recursion); 1267 err1: 1268 return err; 1269 } 1270 1271 static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = { 1272 [IFLA_PPP_DEV_FD] = { .type = NLA_S32 }, 1273 }; 1274 1275 static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[], 1276 struct netlink_ext_ack *extack) 1277 { 1278 if (!data) 1279 return -EINVAL; 1280 1281 if (!data[IFLA_PPP_DEV_FD]) 1282 return -EINVAL; 1283 if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0) 1284 return -EBADF; 1285 1286 return 0; 1287 } 1288 1289 static int ppp_nl_newlink(struct net *src_net, struct net_device *dev, 1290 struct nlattr *tb[], struct nlattr *data[], 1291 struct netlink_ext_ack *extack) 1292 { 1293 struct ppp_config conf = { 1294 .unit = -1, 1295 .ifname_is_set = true, 1296 }; 1297 struct file *file; 1298 int err; 1299 1300 file = fget(nla_get_s32(data[IFLA_PPP_DEV_FD])); 1301 if (!file) 1302 return -EBADF; 1303 1304 /* rtnl_lock is already held here, but ppp_create_interface() locks 1305 * ppp_mutex before holding rtnl_lock. Using mutex_trylock() avoids 1306 * possible deadlock due to lock order inversion, at the cost of 1307 * pushing the problem back to userspace. 1308 */ 1309 if (!mutex_trylock(&ppp_mutex)) { 1310 err = -EBUSY; 1311 goto out; 1312 } 1313 1314 if (file->f_op != &ppp_device_fops || file->private_data) { 1315 err = -EBADF; 1316 goto out_unlock; 1317 } 1318 1319 conf.file = file; 1320 1321 /* Don't use device name generated by the rtnetlink layer when ifname 1322 * isn't specified. Let ppp_dev_configure() set the device name using 1323 * the PPP unit identifer as suffix (i.e. ppp<unit_id>). This allows 1324 * userspace to infer the device name using to the PPPIOCGUNIT ioctl. 1325 */ 1326 if (!tb[IFLA_IFNAME] || !nla_len(tb[IFLA_IFNAME]) || !*(char *)nla_data(tb[IFLA_IFNAME])) 1327 conf.ifname_is_set = false; 1328 1329 err = ppp_dev_configure(src_net, dev, &conf); 1330 1331 out_unlock: 1332 mutex_unlock(&ppp_mutex); 1333 out: 1334 fput(file); 1335 1336 return err; 1337 } 1338 1339 static void ppp_nl_dellink(struct net_device *dev, struct list_head *head) 1340 { 1341 unregister_netdevice_queue(dev, head); 1342 } 1343 1344 static size_t ppp_nl_get_size(const struct net_device *dev) 1345 { 1346 return 0; 1347 } 1348 1349 static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev) 1350 { 1351 return 0; 1352 } 1353 1354 static struct net *ppp_nl_get_link_net(const struct net_device *dev) 1355 { 1356 struct ppp *ppp = netdev_priv(dev); 1357 1358 return ppp->ppp_net; 1359 } 1360 1361 static struct rtnl_link_ops ppp_link_ops __read_mostly = { 1362 .kind = "ppp", 1363 .maxtype = IFLA_PPP_MAX, 1364 .policy = ppp_nl_policy, 1365 .priv_size = sizeof(struct ppp), 1366 .setup = ppp_setup, 1367 .validate = ppp_nl_validate, 1368 .newlink = ppp_nl_newlink, 1369 .dellink = ppp_nl_dellink, 1370 .get_size = ppp_nl_get_size, 1371 .fill_info = ppp_nl_fill_info, 1372 .get_link_net = ppp_nl_get_link_net, 1373 }; 1374 1375 #define PPP_MAJOR 108 1376 1377 /* Called at boot time if ppp is compiled into the kernel, 1378 or at module load time (from init_module) if compiled as a module. */ 1379 static int __init ppp_init(void) 1380 { 1381 int err; 1382 1383 pr_info("PPP generic driver version " PPP_VERSION "\n"); 1384 1385 err = register_pernet_device(&ppp_net_ops); 1386 if (err) { 1387 pr_err("failed to register PPP pernet device (%d)\n", err); 1388 goto out; 1389 } 1390 1391 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops); 1392 if (err) { 1393 pr_err("failed to register PPP device (%d)\n", err); 1394 goto out_net; 1395 } 1396 1397 ppp_class = class_create(THIS_MODULE, "ppp"); 1398 if (IS_ERR(ppp_class)) { 1399 err = PTR_ERR(ppp_class); 1400 goto out_chrdev; 1401 } 1402 1403 err = rtnl_link_register(&ppp_link_ops); 1404 if (err) { 1405 pr_err("failed to register rtnetlink PPP handler\n"); 1406 goto out_class; 1407 } 1408 1409 /* not a big deal if we fail here :-) */ 1410 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp"); 1411 1412 return 0; 1413 1414 out_class: 1415 class_destroy(ppp_class); 1416 out_chrdev: 1417 unregister_chrdev(PPP_MAJOR, "ppp"); 1418 out_net: 1419 unregister_pernet_device(&ppp_net_ops); 1420 out: 1421 return err; 1422 } 1423 1424 /* 1425 * Network interface unit routines. 1426 */ 1427 static netdev_tx_t 1428 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev) 1429 { 1430 struct ppp *ppp = netdev_priv(dev); 1431 int npi, proto; 1432 unsigned char *pp; 1433 1434 npi = ethertype_to_npindex(ntohs(skb->protocol)); 1435 if (npi < 0) 1436 goto outf; 1437 1438 /* Drop, accept or reject the packet */ 1439 switch (ppp->npmode[npi]) { 1440 case NPMODE_PASS: 1441 break; 1442 case NPMODE_QUEUE: 1443 /* it would be nice to have a way to tell the network 1444 system to queue this one up for later. */ 1445 goto outf; 1446 case NPMODE_DROP: 1447 case NPMODE_ERROR: 1448 goto outf; 1449 } 1450 1451 /* Put the 2-byte PPP protocol number on the front, 1452 making sure there is room for the address and control fields. */ 1453 if (skb_cow_head(skb, PPP_HDRLEN)) 1454 goto outf; 1455 1456 pp = skb_push(skb, 2); 1457 proto = npindex_to_proto[npi]; 1458 put_unaligned_be16(proto, pp); 1459 1460 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev))); 1461 ppp_xmit_process(ppp, skb); 1462 1463 return NETDEV_TX_OK; 1464 1465 outf: 1466 kfree_skb(skb); 1467 ++dev->stats.tx_dropped; 1468 return NETDEV_TX_OK; 1469 } 1470 1471 static int 1472 ppp_net_siocdevprivate(struct net_device *dev, struct ifreq *ifr, 1473 void __user *addr, int cmd) 1474 { 1475 struct ppp *ppp = netdev_priv(dev); 1476 int err = -EFAULT; 1477 struct ppp_stats stats; 1478 struct ppp_comp_stats cstats; 1479 char *vers; 1480 1481 switch (cmd) { 1482 case SIOCGPPPSTATS: 1483 ppp_get_stats(ppp, &stats); 1484 if (copy_to_user(addr, &stats, sizeof(stats))) 1485 break; 1486 err = 0; 1487 break; 1488 1489 case SIOCGPPPCSTATS: 1490 memset(&cstats, 0, sizeof(cstats)); 1491 if (ppp->xc_state) 1492 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c); 1493 if (ppp->rc_state) 1494 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d); 1495 if (copy_to_user(addr, &cstats, sizeof(cstats))) 1496 break; 1497 err = 0; 1498 break; 1499 1500 case SIOCGPPPVER: 1501 vers = PPP_VERSION; 1502 if (copy_to_user(addr, vers, strlen(vers) + 1)) 1503 break; 1504 err = 0; 1505 break; 1506 1507 default: 1508 err = -EINVAL; 1509 } 1510 1511 return err; 1512 } 1513 1514 static void 1515 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64) 1516 { 1517 struct ppp *ppp = netdev_priv(dev); 1518 1519 ppp_recv_lock(ppp); 1520 stats64->rx_packets = ppp->stats64.rx_packets; 1521 stats64->rx_bytes = ppp->stats64.rx_bytes; 1522 ppp_recv_unlock(ppp); 1523 1524 ppp_xmit_lock(ppp); 1525 stats64->tx_packets = ppp->stats64.tx_packets; 1526 stats64->tx_bytes = ppp->stats64.tx_bytes; 1527 ppp_xmit_unlock(ppp); 1528 1529 stats64->rx_errors = dev->stats.rx_errors; 1530 stats64->tx_errors = dev->stats.tx_errors; 1531 stats64->rx_dropped = dev->stats.rx_dropped; 1532 stats64->tx_dropped = dev->stats.tx_dropped; 1533 stats64->rx_length_errors = dev->stats.rx_length_errors; 1534 } 1535 1536 static int ppp_dev_init(struct net_device *dev) 1537 { 1538 struct ppp *ppp; 1539 1540 netdev_lockdep_set_classes(dev); 1541 1542 ppp = netdev_priv(dev); 1543 /* Let the netdevice take a reference on the ppp file. This ensures 1544 * that ppp_destroy_interface() won't run before the device gets 1545 * unregistered. 1546 */ 1547 refcount_inc(&ppp->file.refcnt); 1548 1549 return 0; 1550 } 1551 1552 static void ppp_dev_uninit(struct net_device *dev) 1553 { 1554 struct ppp *ppp = netdev_priv(dev); 1555 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 1556 1557 ppp_lock(ppp); 1558 ppp->closing = 1; 1559 ppp_unlock(ppp); 1560 1561 mutex_lock(&pn->all_ppp_mutex); 1562 unit_put(&pn->units_idr, ppp->file.index); 1563 mutex_unlock(&pn->all_ppp_mutex); 1564 1565 ppp->owner = NULL; 1566 1567 ppp->file.dead = 1; 1568 wake_up_interruptible(&ppp->file.rwait); 1569 } 1570 1571 static void ppp_dev_priv_destructor(struct net_device *dev) 1572 { 1573 struct ppp *ppp; 1574 1575 ppp = netdev_priv(dev); 1576 if (refcount_dec_and_test(&ppp->file.refcnt)) 1577 ppp_destroy_interface(ppp); 1578 } 1579 1580 static int ppp_fill_forward_path(struct net_device_path_ctx *ctx, 1581 struct net_device_path *path) 1582 { 1583 struct ppp *ppp = netdev_priv(ctx->dev); 1584 struct ppp_channel *chan; 1585 struct channel *pch; 1586 1587 if (ppp->flags & SC_MULTILINK) 1588 return -EOPNOTSUPP; 1589 1590 if (list_empty(&ppp->channels)) 1591 return -ENODEV; 1592 1593 pch = list_first_entry(&ppp->channels, struct channel, clist); 1594 chan = pch->chan; 1595 if (!chan->ops->fill_forward_path) 1596 return -EOPNOTSUPP; 1597 1598 return chan->ops->fill_forward_path(ctx, path, chan); 1599 } 1600 1601 static const struct net_device_ops ppp_netdev_ops = { 1602 .ndo_init = ppp_dev_init, 1603 .ndo_uninit = ppp_dev_uninit, 1604 .ndo_start_xmit = ppp_start_xmit, 1605 .ndo_siocdevprivate = ppp_net_siocdevprivate, 1606 .ndo_get_stats64 = ppp_get_stats64, 1607 .ndo_fill_forward_path = ppp_fill_forward_path, 1608 }; 1609 1610 static struct device_type ppp_type = { 1611 .name = "ppp", 1612 }; 1613 1614 static void ppp_setup(struct net_device *dev) 1615 { 1616 dev->netdev_ops = &ppp_netdev_ops; 1617 SET_NETDEV_DEVTYPE(dev, &ppp_type); 1618 1619 dev->features |= NETIF_F_LLTX; 1620 1621 dev->hard_header_len = PPP_HDRLEN; 1622 dev->mtu = PPP_MRU; 1623 dev->addr_len = 0; 1624 dev->tx_queue_len = 3; 1625 dev->type = ARPHRD_PPP; 1626 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 1627 dev->priv_destructor = ppp_dev_priv_destructor; 1628 netif_keep_dst(dev); 1629 } 1630 1631 /* 1632 * Transmit-side routines. 1633 */ 1634 1635 /* Called to do any work queued up on the transmit side that can now be done */ 1636 static void __ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb) 1637 { 1638 ppp_xmit_lock(ppp); 1639 if (!ppp->closing) { 1640 ppp_push(ppp); 1641 1642 if (skb) 1643 skb_queue_tail(&ppp->file.xq, skb); 1644 while (!ppp->xmit_pending && 1645 (skb = skb_dequeue(&ppp->file.xq))) 1646 ppp_send_frame(ppp, skb); 1647 /* If there's no work left to do, tell the core net 1648 code that we can accept some more. */ 1649 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq)) 1650 netif_wake_queue(ppp->dev); 1651 else 1652 netif_stop_queue(ppp->dev); 1653 } else { 1654 kfree_skb(skb); 1655 } 1656 ppp_xmit_unlock(ppp); 1657 } 1658 1659 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb) 1660 { 1661 local_bh_disable(); 1662 1663 if (unlikely(*this_cpu_ptr(ppp->xmit_recursion))) 1664 goto err; 1665 1666 (*this_cpu_ptr(ppp->xmit_recursion))++; 1667 __ppp_xmit_process(ppp, skb); 1668 (*this_cpu_ptr(ppp->xmit_recursion))--; 1669 1670 local_bh_enable(); 1671 1672 return; 1673 1674 err: 1675 local_bh_enable(); 1676 1677 kfree_skb(skb); 1678 1679 if (net_ratelimit()) 1680 netdev_err(ppp->dev, "recursion detected\n"); 1681 } 1682 1683 static inline struct sk_buff * 1684 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) 1685 { 1686 struct sk_buff *new_skb; 1687 int len; 1688 int new_skb_size = ppp->dev->mtu + 1689 ppp->xcomp->comp_extra + ppp->dev->hard_header_len; 1690 int compressor_skb_size = ppp->dev->mtu + 1691 ppp->xcomp->comp_extra + PPP_HDRLEN; 1692 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC); 1693 if (!new_skb) { 1694 if (net_ratelimit()) 1695 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n"); 1696 return NULL; 1697 } 1698 if (ppp->dev->hard_header_len > PPP_HDRLEN) 1699 skb_reserve(new_skb, 1700 ppp->dev->hard_header_len - PPP_HDRLEN); 1701 1702 /* compressor still expects A/C bytes in hdr */ 1703 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, 1704 new_skb->data, skb->len + 2, 1705 compressor_skb_size); 1706 if (len > 0 && (ppp->flags & SC_CCP_UP)) { 1707 consume_skb(skb); 1708 skb = new_skb; 1709 skb_put(skb, len); 1710 skb_pull(skb, 2); /* pull off A/C bytes */ 1711 } else if (len == 0) { 1712 /* didn't compress, or CCP not up yet */ 1713 consume_skb(new_skb); 1714 new_skb = skb; 1715 } else { 1716 /* 1717 * (len < 0) 1718 * MPPE requires that we do not send unencrypted 1719 * frames. The compressor will return -1 if we 1720 * should drop the frame. We cannot simply test 1721 * the compress_proto because MPPE and MPPC share 1722 * the same number. 1723 */ 1724 if (net_ratelimit()) 1725 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n"); 1726 kfree_skb(skb); 1727 consume_skb(new_skb); 1728 new_skb = NULL; 1729 } 1730 return new_skb; 1731 } 1732 1733 /* 1734 * Compress and send a frame. 1735 * The caller should have locked the xmit path, 1736 * and xmit_pending should be 0. 1737 */ 1738 static void 1739 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) 1740 { 1741 int proto = PPP_PROTO(skb); 1742 struct sk_buff *new_skb; 1743 int len; 1744 unsigned char *cp; 1745 1746 if (proto < 0x8000) { 1747 #ifdef CONFIG_PPP_FILTER 1748 /* check if we should pass this packet */ 1749 /* the filter instructions are constructed assuming 1750 a four-byte PPP header on each packet */ 1751 *(u8 *)skb_push(skb, 2) = 1; 1752 if (ppp->pass_filter && 1753 bpf_prog_run(ppp->pass_filter, skb) == 0) { 1754 if (ppp->debug & 1) 1755 netdev_printk(KERN_DEBUG, ppp->dev, 1756 "PPP: outbound frame " 1757 "not passed\n"); 1758 kfree_skb(skb); 1759 return; 1760 } 1761 /* if this packet passes the active filter, record the time */ 1762 if (!(ppp->active_filter && 1763 bpf_prog_run(ppp->active_filter, skb) == 0)) 1764 ppp->last_xmit = jiffies; 1765 skb_pull(skb, 2); 1766 #else 1767 /* for data packets, record the time */ 1768 ppp->last_xmit = jiffies; 1769 #endif /* CONFIG_PPP_FILTER */ 1770 } 1771 1772 ++ppp->stats64.tx_packets; 1773 ppp->stats64.tx_bytes += skb->len - PPP_PROTO_LEN; 1774 1775 switch (proto) { 1776 case PPP_IP: 1777 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0) 1778 break; 1779 /* try to do VJ TCP header compression */ 1780 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2, 1781 GFP_ATOMIC); 1782 if (!new_skb) { 1783 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n"); 1784 goto drop; 1785 } 1786 skb_reserve(new_skb, ppp->dev->hard_header_len - 2); 1787 cp = skb->data + 2; 1788 len = slhc_compress(ppp->vj, cp, skb->len - 2, 1789 new_skb->data + 2, &cp, 1790 !(ppp->flags & SC_NO_TCP_CCID)); 1791 if (cp == skb->data + 2) { 1792 /* didn't compress */ 1793 consume_skb(new_skb); 1794 } else { 1795 if (cp[0] & SL_TYPE_COMPRESSED_TCP) { 1796 proto = PPP_VJC_COMP; 1797 cp[0] &= ~SL_TYPE_COMPRESSED_TCP; 1798 } else { 1799 proto = PPP_VJC_UNCOMP; 1800 cp[0] = skb->data[2]; 1801 } 1802 consume_skb(skb); 1803 skb = new_skb; 1804 cp = skb_put(skb, len + 2); 1805 cp[0] = 0; 1806 cp[1] = proto; 1807 } 1808 break; 1809 1810 case PPP_CCP: 1811 /* peek at outbound CCP frames */ 1812 ppp_ccp_peek(ppp, skb, 0); 1813 break; 1814 } 1815 1816 /* try to do packet compression */ 1817 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state && 1818 proto != PPP_LCP && proto != PPP_CCP) { 1819 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) { 1820 if (net_ratelimit()) 1821 netdev_err(ppp->dev, 1822 "ppp: compression required but " 1823 "down - pkt dropped.\n"); 1824 goto drop; 1825 } 1826 skb = pad_compress_skb(ppp, skb); 1827 if (!skb) 1828 goto drop; 1829 } 1830 1831 /* 1832 * If we are waiting for traffic (demand dialling), 1833 * queue it up for pppd to receive. 1834 */ 1835 if (ppp->flags & SC_LOOP_TRAFFIC) { 1836 if (ppp->file.rq.qlen > PPP_MAX_RQLEN) 1837 goto drop; 1838 skb_queue_tail(&ppp->file.rq, skb); 1839 wake_up_interruptible(&ppp->file.rwait); 1840 return; 1841 } 1842 1843 ppp->xmit_pending = skb; 1844 ppp_push(ppp); 1845 return; 1846 1847 drop: 1848 kfree_skb(skb); 1849 ++ppp->dev->stats.tx_errors; 1850 } 1851 1852 /* 1853 * Try to send the frame in xmit_pending. 1854 * The caller should have the xmit path locked. 1855 */ 1856 static void 1857 ppp_push(struct ppp *ppp) 1858 { 1859 struct list_head *list; 1860 struct channel *pch; 1861 struct sk_buff *skb = ppp->xmit_pending; 1862 1863 if (!skb) 1864 return; 1865 1866 list = &ppp->channels; 1867 if (list_empty(list)) { 1868 /* nowhere to send the packet, just drop it */ 1869 ppp->xmit_pending = NULL; 1870 kfree_skb(skb); 1871 return; 1872 } 1873 1874 if ((ppp->flags & SC_MULTILINK) == 0) { 1875 /* not doing multilink: send it down the first channel */ 1876 list = list->next; 1877 pch = list_entry(list, struct channel, clist); 1878 1879 spin_lock(&pch->downl); 1880 if (pch->chan) { 1881 if (pch->chan->ops->start_xmit(pch->chan, skb)) 1882 ppp->xmit_pending = NULL; 1883 } else { 1884 /* channel got unregistered */ 1885 kfree_skb(skb); 1886 ppp->xmit_pending = NULL; 1887 } 1888 spin_unlock(&pch->downl); 1889 return; 1890 } 1891 1892 #ifdef CONFIG_PPP_MULTILINK 1893 /* Multilink: fragment the packet over as many links 1894 as can take the packet at the moment. */ 1895 if (!ppp_mp_explode(ppp, skb)) 1896 return; 1897 #endif /* CONFIG_PPP_MULTILINK */ 1898 1899 ppp->xmit_pending = NULL; 1900 kfree_skb(skb); 1901 } 1902 1903 #ifdef CONFIG_PPP_MULTILINK 1904 static bool mp_protocol_compress __read_mostly = true; 1905 module_param(mp_protocol_compress, bool, 0644); 1906 MODULE_PARM_DESC(mp_protocol_compress, 1907 "compress protocol id in multilink fragments"); 1908 1909 /* 1910 * Divide a packet to be transmitted into fragments and 1911 * send them out the individual links. 1912 */ 1913 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb) 1914 { 1915 int len, totlen; 1916 int i, bits, hdrlen, mtu; 1917 int flen; 1918 int navail, nfree, nzero; 1919 int nbigger; 1920 int totspeed; 1921 int totfree; 1922 unsigned char *p, *q; 1923 struct list_head *list; 1924 struct channel *pch; 1925 struct sk_buff *frag; 1926 struct ppp_channel *chan; 1927 1928 totspeed = 0; /*total bitrate of the bundle*/ 1929 nfree = 0; /* # channels which have no packet already queued */ 1930 navail = 0; /* total # of usable channels (not deregistered) */ 1931 nzero = 0; /* number of channels with zero speed associated*/ 1932 totfree = 0; /*total # of channels available and 1933 *having no queued packets before 1934 *starting the fragmentation*/ 1935 1936 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1937 i = 0; 1938 list_for_each_entry(pch, &ppp->channels, clist) { 1939 if (pch->chan) { 1940 pch->avail = 1; 1941 navail++; 1942 pch->speed = pch->chan->speed; 1943 } else { 1944 pch->avail = 0; 1945 } 1946 if (pch->avail) { 1947 if (skb_queue_empty(&pch->file.xq) || 1948 !pch->had_frag) { 1949 if (pch->speed == 0) 1950 nzero++; 1951 else 1952 totspeed += pch->speed; 1953 1954 pch->avail = 2; 1955 ++nfree; 1956 ++totfree; 1957 } 1958 if (!pch->had_frag && i < ppp->nxchan) 1959 ppp->nxchan = i; 1960 } 1961 ++i; 1962 } 1963 /* 1964 * Don't start sending this packet unless at least half of 1965 * the channels are free. This gives much better TCP 1966 * performance if we have a lot of channels. 1967 */ 1968 if (nfree == 0 || nfree < navail / 2) 1969 return 0; /* can't take now, leave it in xmit_pending */ 1970 1971 /* Do protocol field compression */ 1972 p = skb->data; 1973 len = skb->len; 1974 if (*p == 0 && mp_protocol_compress) { 1975 ++p; 1976 --len; 1977 } 1978 1979 totlen = len; 1980 nbigger = len % nfree; 1981 1982 /* skip to the channel after the one we last used 1983 and start at that one */ 1984 list = &ppp->channels; 1985 for (i = 0; i < ppp->nxchan; ++i) { 1986 list = list->next; 1987 if (list == &ppp->channels) { 1988 i = 0; 1989 break; 1990 } 1991 } 1992 1993 /* create a fragment for each channel */ 1994 bits = B; 1995 while (len > 0) { 1996 list = list->next; 1997 if (list == &ppp->channels) { 1998 i = 0; 1999 continue; 2000 } 2001 pch = list_entry(list, struct channel, clist); 2002 ++i; 2003 if (!pch->avail) 2004 continue; 2005 2006 /* 2007 * Skip this channel if it has a fragment pending already and 2008 * we haven't given a fragment to all of the free channels. 2009 */ 2010 if (pch->avail == 1) { 2011 if (nfree > 0) 2012 continue; 2013 } else { 2014 pch->avail = 1; 2015 } 2016 2017 /* check the channel's mtu and whether it is still attached. */ 2018 spin_lock(&pch->downl); 2019 if (pch->chan == NULL) { 2020 /* can't use this channel, it's being deregistered */ 2021 if (pch->speed == 0) 2022 nzero--; 2023 else 2024 totspeed -= pch->speed; 2025 2026 spin_unlock(&pch->downl); 2027 pch->avail = 0; 2028 totlen = len; 2029 totfree--; 2030 nfree--; 2031 if (--navail == 0) 2032 break; 2033 continue; 2034 } 2035 2036 /* 2037 *if the channel speed is not set divide 2038 *the packet evenly among the free channels; 2039 *otherwise divide it according to the speed 2040 *of the channel we are going to transmit on 2041 */ 2042 flen = len; 2043 if (nfree > 0) { 2044 if (pch->speed == 0) { 2045 flen = len/nfree; 2046 if (nbigger > 0) { 2047 flen++; 2048 nbigger--; 2049 } 2050 } else { 2051 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) / 2052 ((totspeed*totfree)/pch->speed)) - hdrlen; 2053 if (nbigger > 0) { 2054 flen += ((totfree - nzero)*pch->speed)/totspeed; 2055 nbigger -= ((totfree - nzero)*pch->speed)/ 2056 totspeed; 2057 } 2058 } 2059 nfree--; 2060 } 2061 2062 /* 2063 *check if we are on the last channel or 2064 *we exceded the length of the data to 2065 *fragment 2066 */ 2067 if ((nfree <= 0) || (flen > len)) 2068 flen = len; 2069 /* 2070 *it is not worth to tx on slow channels: 2071 *in that case from the resulting flen according to the 2072 *above formula will be equal or less than zero. 2073 *Skip the channel in this case 2074 */ 2075 if (flen <= 0) { 2076 pch->avail = 2; 2077 spin_unlock(&pch->downl); 2078 continue; 2079 } 2080 2081 /* 2082 * hdrlen includes the 2-byte PPP protocol field, but the 2083 * MTU counts only the payload excluding the protocol field. 2084 * (RFC1661 Section 2) 2085 */ 2086 mtu = pch->chan->mtu - (hdrlen - 2); 2087 if (mtu < 4) 2088 mtu = 4; 2089 if (flen > mtu) 2090 flen = mtu; 2091 if (flen == len) 2092 bits |= E; 2093 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC); 2094 if (!frag) 2095 goto noskb; 2096 q = skb_put(frag, flen + hdrlen); 2097 2098 /* make the MP header */ 2099 put_unaligned_be16(PPP_MP, q); 2100 if (ppp->flags & SC_MP_XSHORTSEQ) { 2101 q[2] = bits + ((ppp->nxseq >> 8) & 0xf); 2102 q[3] = ppp->nxseq; 2103 } else { 2104 q[2] = bits; 2105 q[3] = ppp->nxseq >> 16; 2106 q[4] = ppp->nxseq >> 8; 2107 q[5] = ppp->nxseq; 2108 } 2109 2110 memcpy(q + hdrlen, p, flen); 2111 2112 /* try to send it down the channel */ 2113 chan = pch->chan; 2114 if (!skb_queue_empty(&pch->file.xq) || 2115 !chan->ops->start_xmit(chan, frag)) 2116 skb_queue_tail(&pch->file.xq, frag); 2117 pch->had_frag = 1; 2118 p += flen; 2119 len -= flen; 2120 ++ppp->nxseq; 2121 bits = 0; 2122 spin_unlock(&pch->downl); 2123 } 2124 ppp->nxchan = i; 2125 2126 return 1; 2127 2128 noskb: 2129 spin_unlock(&pch->downl); 2130 if (ppp->debug & 1) 2131 netdev_err(ppp->dev, "PPP: no memory (fragment)\n"); 2132 ++ppp->dev->stats.tx_errors; 2133 ++ppp->nxseq; 2134 return 1; /* abandon the frame */ 2135 } 2136 #endif /* CONFIG_PPP_MULTILINK */ 2137 2138 /* Try to send data out on a channel */ 2139 static void __ppp_channel_push(struct channel *pch) 2140 { 2141 struct sk_buff *skb; 2142 struct ppp *ppp; 2143 2144 spin_lock(&pch->downl); 2145 if (pch->chan) { 2146 while (!skb_queue_empty(&pch->file.xq)) { 2147 skb = skb_dequeue(&pch->file.xq); 2148 if (!pch->chan->ops->start_xmit(pch->chan, skb)) { 2149 /* put the packet back and try again later */ 2150 skb_queue_head(&pch->file.xq, skb); 2151 break; 2152 } 2153 } 2154 } else { 2155 /* channel got deregistered */ 2156 skb_queue_purge(&pch->file.xq); 2157 } 2158 spin_unlock(&pch->downl); 2159 /* see if there is anything from the attached unit to be sent */ 2160 if (skb_queue_empty(&pch->file.xq)) { 2161 ppp = pch->ppp; 2162 if (ppp) 2163 __ppp_xmit_process(ppp, NULL); 2164 } 2165 } 2166 2167 static void ppp_channel_push(struct channel *pch) 2168 { 2169 read_lock_bh(&pch->upl); 2170 if (pch->ppp) { 2171 (*this_cpu_ptr(pch->ppp->xmit_recursion))++; 2172 __ppp_channel_push(pch); 2173 (*this_cpu_ptr(pch->ppp->xmit_recursion))--; 2174 } else { 2175 __ppp_channel_push(pch); 2176 } 2177 read_unlock_bh(&pch->upl); 2178 } 2179 2180 /* 2181 * Receive-side routines. 2182 */ 2183 2184 struct ppp_mp_skb_parm { 2185 u32 sequence; 2186 u8 BEbits; 2187 }; 2188 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb)) 2189 2190 static inline void 2191 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2192 { 2193 ppp_recv_lock(ppp); 2194 if (!ppp->closing) 2195 ppp_receive_frame(ppp, skb, pch); 2196 else 2197 kfree_skb(skb); 2198 ppp_recv_unlock(ppp); 2199 } 2200 2201 /** 2202 * __ppp_decompress_proto - Decompress protocol field, slim version. 2203 * @skb: Socket buffer where protocol field should be decompressed. It must have 2204 * at least 1 byte of head room and 1 byte of linear data. First byte of 2205 * data must be a protocol field byte. 2206 * 2207 * Decompress protocol field in PPP header if it's compressed, e.g. when 2208 * Protocol-Field-Compression (PFC) was negotiated. No checks w.r.t. skb data 2209 * length are done in this function. 2210 */ 2211 static void __ppp_decompress_proto(struct sk_buff *skb) 2212 { 2213 if (skb->data[0] & 0x01) 2214 *(u8 *)skb_push(skb, 1) = 0x00; 2215 } 2216 2217 /** 2218 * ppp_decompress_proto - Check skb data room and decompress protocol field. 2219 * @skb: Socket buffer where protocol field should be decompressed. First byte 2220 * of data must be a protocol field byte. 2221 * 2222 * Decompress protocol field in PPP header if it's compressed, e.g. when 2223 * Protocol-Field-Compression (PFC) was negotiated. This function also makes 2224 * sure that skb data room is sufficient for Protocol field, before and after 2225 * decompression. 2226 * 2227 * Return: true - decompressed successfully, false - not enough room in skb. 2228 */ 2229 static bool ppp_decompress_proto(struct sk_buff *skb) 2230 { 2231 /* At least one byte should be present (if protocol is compressed) */ 2232 if (!pskb_may_pull(skb, 1)) 2233 return false; 2234 2235 __ppp_decompress_proto(skb); 2236 2237 /* Protocol field should occupy 2 bytes when not compressed */ 2238 return pskb_may_pull(skb, 2); 2239 } 2240 2241 /* Attempt to handle a frame via. a bridged channel, if one exists. 2242 * If the channel is bridged, the frame is consumed by the bridge. 2243 * If not, the caller must handle the frame by normal recv mechanisms. 2244 * Returns true if the frame is consumed, false otherwise. 2245 */ 2246 static bool ppp_channel_bridge_input(struct channel *pch, struct sk_buff *skb) 2247 { 2248 struct channel *pchb; 2249 2250 rcu_read_lock(); 2251 pchb = rcu_dereference(pch->bridge); 2252 if (!pchb) 2253 goto out_rcu; 2254 2255 spin_lock(&pchb->downl); 2256 if (!pchb->chan) { 2257 /* channel got unregistered */ 2258 kfree_skb(skb); 2259 goto outl; 2260 } 2261 2262 skb_scrub_packet(skb, !net_eq(pch->chan_net, pchb->chan_net)); 2263 if (!pchb->chan->ops->start_xmit(pchb->chan, skb)) 2264 kfree_skb(skb); 2265 2266 outl: 2267 spin_unlock(&pchb->downl); 2268 out_rcu: 2269 rcu_read_unlock(); 2270 2271 /* If pchb is set then we've consumed the packet */ 2272 return !!pchb; 2273 } 2274 2275 void 2276 ppp_input(struct ppp_channel *chan, struct sk_buff *skb) 2277 { 2278 struct channel *pch = chan->ppp; 2279 int proto; 2280 2281 if (!pch) { 2282 kfree_skb(skb); 2283 return; 2284 } 2285 2286 /* If the channel is bridged, transmit via. bridge */ 2287 if (ppp_channel_bridge_input(pch, skb)) 2288 return; 2289 2290 read_lock_bh(&pch->upl); 2291 if (!ppp_decompress_proto(skb)) { 2292 kfree_skb(skb); 2293 if (pch->ppp) { 2294 ++pch->ppp->dev->stats.rx_length_errors; 2295 ppp_receive_error(pch->ppp); 2296 } 2297 goto done; 2298 } 2299 2300 proto = PPP_PROTO(skb); 2301 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) { 2302 /* put it on the channel queue */ 2303 skb_queue_tail(&pch->file.rq, skb); 2304 /* drop old frames if queue too long */ 2305 while (pch->file.rq.qlen > PPP_MAX_RQLEN && 2306 (skb = skb_dequeue(&pch->file.rq))) 2307 kfree_skb(skb); 2308 wake_up_interruptible(&pch->file.rwait); 2309 } else { 2310 ppp_do_recv(pch->ppp, skb, pch); 2311 } 2312 2313 done: 2314 read_unlock_bh(&pch->upl); 2315 } 2316 2317 /* Put a 0-length skb in the receive queue as an error indication */ 2318 void 2319 ppp_input_error(struct ppp_channel *chan, int code) 2320 { 2321 struct channel *pch = chan->ppp; 2322 struct sk_buff *skb; 2323 2324 if (!pch) 2325 return; 2326 2327 read_lock_bh(&pch->upl); 2328 if (pch->ppp) { 2329 skb = alloc_skb(0, GFP_ATOMIC); 2330 if (skb) { 2331 skb->len = 0; /* probably unnecessary */ 2332 skb->cb[0] = code; 2333 ppp_do_recv(pch->ppp, skb, pch); 2334 } 2335 } 2336 read_unlock_bh(&pch->upl); 2337 } 2338 2339 /* 2340 * We come in here to process a received frame. 2341 * The receive side of the ppp unit is locked. 2342 */ 2343 static void 2344 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2345 { 2346 /* note: a 0-length skb is used as an error indication */ 2347 if (skb->len > 0) { 2348 skb_checksum_complete_unset(skb); 2349 #ifdef CONFIG_PPP_MULTILINK 2350 /* XXX do channel-level decompression here */ 2351 if (PPP_PROTO(skb) == PPP_MP) 2352 ppp_receive_mp_frame(ppp, skb, pch); 2353 else 2354 #endif /* CONFIG_PPP_MULTILINK */ 2355 ppp_receive_nonmp_frame(ppp, skb); 2356 } else { 2357 kfree_skb(skb); 2358 ppp_receive_error(ppp); 2359 } 2360 } 2361 2362 static void 2363 ppp_receive_error(struct ppp *ppp) 2364 { 2365 ++ppp->dev->stats.rx_errors; 2366 if (ppp->vj) 2367 slhc_toss(ppp->vj); 2368 } 2369 2370 static void 2371 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) 2372 { 2373 struct sk_buff *ns; 2374 int proto, len, npi; 2375 2376 /* 2377 * Decompress the frame, if compressed. 2378 * Note that some decompressors need to see uncompressed frames 2379 * that come in as well as compressed frames. 2380 */ 2381 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) && 2382 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0) 2383 skb = ppp_decompress_frame(ppp, skb); 2384 2385 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR) 2386 goto err; 2387 2388 /* At this point the "Protocol" field MUST be decompressed, either in 2389 * ppp_input(), ppp_decompress_frame() or in ppp_receive_mp_frame(). 2390 */ 2391 proto = PPP_PROTO(skb); 2392 switch (proto) { 2393 case PPP_VJC_COMP: 2394 /* decompress VJ compressed packets */ 2395 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 2396 goto err; 2397 2398 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) { 2399 /* copy to a new sk_buff with more tailroom */ 2400 ns = dev_alloc_skb(skb->len + 128); 2401 if (!ns) { 2402 netdev_err(ppp->dev, "PPP: no memory " 2403 "(VJ decomp)\n"); 2404 goto err; 2405 } 2406 skb_reserve(ns, 2); 2407 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len); 2408 consume_skb(skb); 2409 skb = ns; 2410 } 2411 else 2412 skb->ip_summed = CHECKSUM_NONE; 2413 2414 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2); 2415 if (len <= 0) { 2416 netdev_printk(KERN_DEBUG, ppp->dev, 2417 "PPP: VJ decompression error\n"); 2418 goto err; 2419 } 2420 len += 2; 2421 if (len > skb->len) 2422 skb_put(skb, len - skb->len); 2423 else if (len < skb->len) 2424 skb_trim(skb, len); 2425 proto = PPP_IP; 2426 break; 2427 2428 case PPP_VJC_UNCOMP: 2429 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 2430 goto err; 2431 2432 /* Until we fix the decompressor need to make sure 2433 * data portion is linear. 2434 */ 2435 if (!pskb_may_pull(skb, skb->len)) 2436 goto err; 2437 2438 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) { 2439 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n"); 2440 goto err; 2441 } 2442 proto = PPP_IP; 2443 break; 2444 2445 case PPP_CCP: 2446 ppp_ccp_peek(ppp, skb, 1); 2447 break; 2448 } 2449 2450 ++ppp->stats64.rx_packets; 2451 ppp->stats64.rx_bytes += skb->len - 2; 2452 2453 npi = proto_to_npindex(proto); 2454 if (npi < 0) { 2455 /* control or unknown frame - pass it to pppd */ 2456 skb_queue_tail(&ppp->file.rq, skb); 2457 /* limit queue length by dropping old frames */ 2458 while (ppp->file.rq.qlen > PPP_MAX_RQLEN && 2459 (skb = skb_dequeue(&ppp->file.rq))) 2460 kfree_skb(skb); 2461 /* wake up any process polling or blocking on read */ 2462 wake_up_interruptible(&ppp->file.rwait); 2463 2464 } else { 2465 /* network protocol frame - give it to the kernel */ 2466 2467 #ifdef CONFIG_PPP_FILTER 2468 /* check if the packet passes the pass and active filters */ 2469 /* the filter instructions are constructed assuming 2470 a four-byte PPP header on each packet */ 2471 if (ppp->pass_filter || ppp->active_filter) { 2472 if (skb_unclone(skb, GFP_ATOMIC)) 2473 goto err; 2474 2475 *(u8 *)skb_push(skb, 2) = 0; 2476 if (ppp->pass_filter && 2477 bpf_prog_run(ppp->pass_filter, skb) == 0) { 2478 if (ppp->debug & 1) 2479 netdev_printk(KERN_DEBUG, ppp->dev, 2480 "PPP: inbound frame " 2481 "not passed\n"); 2482 kfree_skb(skb); 2483 return; 2484 } 2485 if (!(ppp->active_filter && 2486 bpf_prog_run(ppp->active_filter, skb) == 0)) 2487 ppp->last_recv = jiffies; 2488 __skb_pull(skb, 2); 2489 } else 2490 #endif /* CONFIG_PPP_FILTER */ 2491 ppp->last_recv = jiffies; 2492 2493 if ((ppp->dev->flags & IFF_UP) == 0 || 2494 ppp->npmode[npi] != NPMODE_PASS) { 2495 kfree_skb(skb); 2496 } else { 2497 /* chop off protocol */ 2498 skb_pull_rcsum(skb, 2); 2499 skb->dev = ppp->dev; 2500 skb->protocol = htons(npindex_to_ethertype[npi]); 2501 skb_reset_mac_header(skb); 2502 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, 2503 dev_net(ppp->dev))); 2504 netif_rx(skb); 2505 } 2506 } 2507 return; 2508 2509 err: 2510 kfree_skb(skb); 2511 ppp_receive_error(ppp); 2512 } 2513 2514 static struct sk_buff * 2515 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb) 2516 { 2517 int proto = PPP_PROTO(skb); 2518 struct sk_buff *ns; 2519 int len; 2520 2521 /* Until we fix all the decompressor's need to make sure 2522 * data portion is linear. 2523 */ 2524 if (!pskb_may_pull(skb, skb->len)) 2525 goto err; 2526 2527 if (proto == PPP_COMP) { 2528 int obuff_size; 2529 2530 switch(ppp->rcomp->compress_proto) { 2531 case CI_MPPE: 2532 obuff_size = ppp->mru + PPP_HDRLEN + 1; 2533 break; 2534 default: 2535 obuff_size = ppp->mru + PPP_HDRLEN; 2536 break; 2537 } 2538 2539 ns = dev_alloc_skb(obuff_size); 2540 if (!ns) { 2541 netdev_err(ppp->dev, "ppp_decompress_frame: " 2542 "no memory\n"); 2543 goto err; 2544 } 2545 /* the decompressor still expects the A/C bytes in the hdr */ 2546 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2, 2547 skb->len + 2, ns->data, obuff_size); 2548 if (len < 0) { 2549 /* Pass the compressed frame to pppd as an 2550 error indication. */ 2551 if (len == DECOMP_FATALERROR) 2552 ppp->rstate |= SC_DC_FERROR; 2553 kfree_skb(ns); 2554 goto err; 2555 } 2556 2557 consume_skb(skb); 2558 skb = ns; 2559 skb_put(skb, len); 2560 skb_pull(skb, 2); /* pull off the A/C bytes */ 2561 2562 /* Don't call __ppp_decompress_proto() here, but instead rely on 2563 * corresponding algo (mppe/bsd/deflate) to decompress it. 2564 */ 2565 } else { 2566 /* Uncompressed frame - pass to decompressor so it 2567 can update its dictionary if necessary. */ 2568 if (ppp->rcomp->incomp) 2569 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2, 2570 skb->len + 2); 2571 } 2572 2573 return skb; 2574 2575 err: 2576 ppp->rstate |= SC_DC_ERROR; 2577 ppp_receive_error(ppp); 2578 return skb; 2579 } 2580 2581 #ifdef CONFIG_PPP_MULTILINK 2582 /* 2583 * Receive a multilink frame. 2584 * We put it on the reconstruction queue and then pull off 2585 * as many completed frames as we can. 2586 */ 2587 static void 2588 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2589 { 2590 u32 mask, seq; 2591 struct channel *ch; 2592 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 2593 2594 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0) 2595 goto err; /* no good, throw it away */ 2596 2597 /* Decode sequence number and begin/end bits */ 2598 if (ppp->flags & SC_MP_SHORTSEQ) { 2599 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3]; 2600 mask = 0xfff; 2601 } else { 2602 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5]; 2603 mask = 0xffffff; 2604 } 2605 PPP_MP_CB(skb)->BEbits = skb->data[2]; 2606 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */ 2607 2608 /* 2609 * Do protocol ID decompression on the first fragment of each packet. 2610 * We have to do that here, because ppp_receive_nonmp_frame() expects 2611 * decompressed protocol field. 2612 */ 2613 if (PPP_MP_CB(skb)->BEbits & B) 2614 __ppp_decompress_proto(skb); 2615 2616 /* 2617 * Expand sequence number to 32 bits, making it as close 2618 * as possible to ppp->minseq. 2619 */ 2620 seq |= ppp->minseq & ~mask; 2621 if ((int)(ppp->minseq - seq) > (int)(mask >> 1)) 2622 seq += mask + 1; 2623 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1)) 2624 seq -= mask + 1; /* should never happen */ 2625 PPP_MP_CB(skb)->sequence = seq; 2626 pch->lastseq = seq; 2627 2628 /* 2629 * If this packet comes before the next one we were expecting, 2630 * drop it. 2631 */ 2632 if (seq_before(seq, ppp->nextseq)) { 2633 kfree_skb(skb); 2634 ++ppp->dev->stats.rx_dropped; 2635 ppp_receive_error(ppp); 2636 return; 2637 } 2638 2639 /* 2640 * Reevaluate minseq, the minimum over all channels of the 2641 * last sequence number received on each channel. Because of 2642 * the increasing sequence number rule, we know that any fragment 2643 * before `minseq' which hasn't arrived is never going to arrive. 2644 * The list of channels can't change because we have the receive 2645 * side of the ppp unit locked. 2646 */ 2647 list_for_each_entry(ch, &ppp->channels, clist) { 2648 if (seq_before(ch->lastseq, seq)) 2649 seq = ch->lastseq; 2650 } 2651 if (seq_before(ppp->minseq, seq)) 2652 ppp->minseq = seq; 2653 2654 /* Put the fragment on the reconstruction queue */ 2655 ppp_mp_insert(ppp, skb); 2656 2657 /* If the queue is getting long, don't wait any longer for packets 2658 before the start of the queue. */ 2659 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) { 2660 struct sk_buff *mskb = skb_peek(&ppp->mrq); 2661 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence)) 2662 ppp->minseq = PPP_MP_CB(mskb)->sequence; 2663 } 2664 2665 /* Pull completed packets off the queue and receive them. */ 2666 while ((skb = ppp_mp_reconstruct(ppp))) { 2667 if (pskb_may_pull(skb, 2)) 2668 ppp_receive_nonmp_frame(ppp, skb); 2669 else { 2670 ++ppp->dev->stats.rx_length_errors; 2671 kfree_skb(skb); 2672 ppp_receive_error(ppp); 2673 } 2674 } 2675 2676 return; 2677 2678 err: 2679 kfree_skb(skb); 2680 ppp_receive_error(ppp); 2681 } 2682 2683 /* 2684 * Insert a fragment on the MP reconstruction queue. 2685 * The queue is ordered by increasing sequence number. 2686 */ 2687 static void 2688 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb) 2689 { 2690 struct sk_buff *p; 2691 struct sk_buff_head *list = &ppp->mrq; 2692 u32 seq = PPP_MP_CB(skb)->sequence; 2693 2694 /* N.B. we don't need to lock the list lock because we have the 2695 ppp unit receive-side lock. */ 2696 skb_queue_walk(list, p) { 2697 if (seq_before(seq, PPP_MP_CB(p)->sequence)) 2698 break; 2699 } 2700 __skb_queue_before(list, p, skb); 2701 } 2702 2703 /* 2704 * Reconstruct a packet from the MP fragment queue. 2705 * We go through increasing sequence numbers until we find a 2706 * complete packet, or we get to the sequence number for a fragment 2707 * which hasn't arrived but might still do so. 2708 */ 2709 static struct sk_buff * 2710 ppp_mp_reconstruct(struct ppp *ppp) 2711 { 2712 u32 seq = ppp->nextseq; 2713 u32 minseq = ppp->minseq; 2714 struct sk_buff_head *list = &ppp->mrq; 2715 struct sk_buff *p, *tmp; 2716 struct sk_buff *head, *tail; 2717 struct sk_buff *skb = NULL; 2718 int lost = 0, len = 0; 2719 2720 if (ppp->mrru == 0) /* do nothing until mrru is set */ 2721 return NULL; 2722 head = __skb_peek(list); 2723 tail = NULL; 2724 skb_queue_walk_safe(list, p, tmp) { 2725 again: 2726 if (seq_before(PPP_MP_CB(p)->sequence, seq)) { 2727 /* this can't happen, anyway ignore the skb */ 2728 netdev_err(ppp->dev, "ppp_mp_reconstruct bad " 2729 "seq %u < %u\n", 2730 PPP_MP_CB(p)->sequence, seq); 2731 __skb_unlink(p, list); 2732 kfree_skb(p); 2733 continue; 2734 } 2735 if (PPP_MP_CB(p)->sequence != seq) { 2736 u32 oldseq; 2737 /* Fragment `seq' is missing. If it is after 2738 minseq, it might arrive later, so stop here. */ 2739 if (seq_after(seq, minseq)) 2740 break; 2741 /* Fragment `seq' is lost, keep going. */ 2742 lost = 1; 2743 oldseq = seq; 2744 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)? 2745 minseq + 1: PPP_MP_CB(p)->sequence; 2746 2747 if (ppp->debug & 1) 2748 netdev_printk(KERN_DEBUG, ppp->dev, 2749 "lost frag %u..%u\n", 2750 oldseq, seq-1); 2751 2752 goto again; 2753 } 2754 2755 /* 2756 * At this point we know that all the fragments from 2757 * ppp->nextseq to seq are either present or lost. 2758 * Also, there are no complete packets in the queue 2759 * that have no missing fragments and end before this 2760 * fragment. 2761 */ 2762 2763 /* B bit set indicates this fragment starts a packet */ 2764 if (PPP_MP_CB(p)->BEbits & B) { 2765 head = p; 2766 lost = 0; 2767 len = 0; 2768 } 2769 2770 len += p->len; 2771 2772 /* Got a complete packet yet? */ 2773 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) && 2774 (PPP_MP_CB(head)->BEbits & B)) { 2775 if (len > ppp->mrru + 2) { 2776 ++ppp->dev->stats.rx_length_errors; 2777 netdev_printk(KERN_DEBUG, ppp->dev, 2778 "PPP: reconstructed packet" 2779 " is too long (%d)\n", len); 2780 } else { 2781 tail = p; 2782 break; 2783 } 2784 ppp->nextseq = seq + 1; 2785 } 2786 2787 /* 2788 * If this is the ending fragment of a packet, 2789 * and we haven't found a complete valid packet yet, 2790 * we can discard up to and including this fragment. 2791 */ 2792 if (PPP_MP_CB(p)->BEbits & E) { 2793 struct sk_buff *tmp2; 2794 2795 skb_queue_reverse_walk_from_safe(list, p, tmp2) { 2796 if (ppp->debug & 1) 2797 netdev_printk(KERN_DEBUG, ppp->dev, 2798 "discarding frag %u\n", 2799 PPP_MP_CB(p)->sequence); 2800 __skb_unlink(p, list); 2801 kfree_skb(p); 2802 } 2803 head = skb_peek(list); 2804 if (!head) 2805 break; 2806 } 2807 ++seq; 2808 } 2809 2810 /* If we have a complete packet, copy it all into one skb. */ 2811 if (tail != NULL) { 2812 /* If we have discarded any fragments, 2813 signal a receive error. */ 2814 if (PPP_MP_CB(head)->sequence != ppp->nextseq) { 2815 skb_queue_walk_safe(list, p, tmp) { 2816 if (p == head) 2817 break; 2818 if (ppp->debug & 1) 2819 netdev_printk(KERN_DEBUG, ppp->dev, 2820 "discarding frag %u\n", 2821 PPP_MP_CB(p)->sequence); 2822 __skb_unlink(p, list); 2823 kfree_skb(p); 2824 } 2825 2826 if (ppp->debug & 1) 2827 netdev_printk(KERN_DEBUG, ppp->dev, 2828 " missed pkts %u..%u\n", 2829 ppp->nextseq, 2830 PPP_MP_CB(head)->sequence-1); 2831 ++ppp->dev->stats.rx_dropped; 2832 ppp_receive_error(ppp); 2833 } 2834 2835 skb = head; 2836 if (head != tail) { 2837 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list; 2838 p = skb_queue_next(list, head); 2839 __skb_unlink(skb, list); 2840 skb_queue_walk_from_safe(list, p, tmp) { 2841 __skb_unlink(p, list); 2842 *fragpp = p; 2843 p->next = NULL; 2844 fragpp = &p->next; 2845 2846 skb->len += p->len; 2847 skb->data_len += p->len; 2848 skb->truesize += p->truesize; 2849 2850 if (p == tail) 2851 break; 2852 } 2853 } else { 2854 __skb_unlink(skb, list); 2855 } 2856 2857 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1; 2858 } 2859 2860 return skb; 2861 } 2862 #endif /* CONFIG_PPP_MULTILINK */ 2863 2864 /* 2865 * Channel interface. 2866 */ 2867 2868 /* Create a new, unattached ppp channel. */ 2869 int ppp_register_channel(struct ppp_channel *chan) 2870 { 2871 return ppp_register_net_channel(current->nsproxy->net_ns, chan); 2872 } 2873 2874 /* Create a new, unattached ppp channel for specified net. */ 2875 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan) 2876 { 2877 struct channel *pch; 2878 struct ppp_net *pn; 2879 2880 pch = kzalloc(sizeof(struct channel), GFP_KERNEL); 2881 if (!pch) 2882 return -ENOMEM; 2883 2884 pn = ppp_pernet(net); 2885 2886 pch->ppp = NULL; 2887 pch->chan = chan; 2888 pch->chan_net = get_net_track(net, &pch->ns_tracker, GFP_KERNEL); 2889 chan->ppp = pch; 2890 init_ppp_file(&pch->file, CHANNEL); 2891 pch->file.hdrlen = chan->hdrlen; 2892 #ifdef CONFIG_PPP_MULTILINK 2893 pch->lastseq = -1; 2894 #endif /* CONFIG_PPP_MULTILINK */ 2895 init_rwsem(&pch->chan_sem); 2896 spin_lock_init(&pch->downl); 2897 rwlock_init(&pch->upl); 2898 2899 spin_lock_bh(&pn->all_channels_lock); 2900 pch->file.index = ++pn->last_channel_index; 2901 list_add(&pch->list, &pn->new_channels); 2902 atomic_inc(&channel_count); 2903 spin_unlock_bh(&pn->all_channels_lock); 2904 2905 return 0; 2906 } 2907 2908 /* 2909 * Return the index of a channel. 2910 */ 2911 int ppp_channel_index(struct ppp_channel *chan) 2912 { 2913 struct channel *pch = chan->ppp; 2914 2915 if (pch) 2916 return pch->file.index; 2917 return -1; 2918 } 2919 2920 /* 2921 * Return the PPP unit number to which a channel is connected. 2922 */ 2923 int ppp_unit_number(struct ppp_channel *chan) 2924 { 2925 struct channel *pch = chan->ppp; 2926 int unit = -1; 2927 2928 if (pch) { 2929 read_lock_bh(&pch->upl); 2930 if (pch->ppp) 2931 unit = pch->ppp->file.index; 2932 read_unlock_bh(&pch->upl); 2933 } 2934 return unit; 2935 } 2936 2937 /* 2938 * Return the PPP device interface name of a channel. 2939 */ 2940 char *ppp_dev_name(struct ppp_channel *chan) 2941 { 2942 struct channel *pch = chan->ppp; 2943 char *name = NULL; 2944 2945 if (pch) { 2946 read_lock_bh(&pch->upl); 2947 if (pch->ppp && pch->ppp->dev) 2948 name = pch->ppp->dev->name; 2949 read_unlock_bh(&pch->upl); 2950 } 2951 return name; 2952 } 2953 2954 2955 /* 2956 * Disconnect a channel from the generic layer. 2957 * This must be called in process context. 2958 */ 2959 void 2960 ppp_unregister_channel(struct ppp_channel *chan) 2961 { 2962 struct channel *pch = chan->ppp; 2963 struct ppp_net *pn; 2964 2965 if (!pch) 2966 return; /* should never happen */ 2967 2968 chan->ppp = NULL; 2969 2970 /* 2971 * This ensures that we have returned from any calls into 2972 * the channel's start_xmit or ioctl routine before we proceed. 2973 */ 2974 down_write(&pch->chan_sem); 2975 spin_lock_bh(&pch->downl); 2976 pch->chan = NULL; 2977 spin_unlock_bh(&pch->downl); 2978 up_write(&pch->chan_sem); 2979 ppp_disconnect_channel(pch); 2980 2981 pn = ppp_pernet(pch->chan_net); 2982 spin_lock_bh(&pn->all_channels_lock); 2983 list_del(&pch->list); 2984 spin_unlock_bh(&pn->all_channels_lock); 2985 2986 ppp_unbridge_channels(pch); 2987 2988 pch->file.dead = 1; 2989 wake_up_interruptible(&pch->file.rwait); 2990 2991 if (refcount_dec_and_test(&pch->file.refcnt)) 2992 ppp_destroy_channel(pch); 2993 } 2994 2995 /* 2996 * Callback from a channel when it can accept more to transmit. 2997 * This should be called at BH/softirq level, not interrupt level. 2998 */ 2999 void 3000 ppp_output_wakeup(struct ppp_channel *chan) 3001 { 3002 struct channel *pch = chan->ppp; 3003 3004 if (!pch) 3005 return; 3006 ppp_channel_push(pch); 3007 } 3008 3009 /* 3010 * Compression control. 3011 */ 3012 3013 /* Process the PPPIOCSCOMPRESS ioctl. */ 3014 static int 3015 ppp_set_compress(struct ppp *ppp, struct ppp_option_data *data) 3016 { 3017 int err = -EFAULT; 3018 struct compressor *cp, *ocomp; 3019 void *state, *ostate; 3020 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH]; 3021 3022 if (data->length > CCP_MAX_OPTION_LENGTH) 3023 goto out; 3024 if (copy_from_user(ccp_option, data->ptr, data->length)) 3025 goto out; 3026 3027 err = -EINVAL; 3028 if (data->length < 2 || ccp_option[1] < 2 || ccp_option[1] > data->length) 3029 goto out; 3030 3031 cp = try_then_request_module( 3032 find_compressor(ccp_option[0]), 3033 "ppp-compress-%d", ccp_option[0]); 3034 if (!cp) 3035 goto out; 3036 3037 err = -ENOBUFS; 3038 if (data->transmit) { 3039 state = cp->comp_alloc(ccp_option, data->length); 3040 if (state) { 3041 ppp_xmit_lock(ppp); 3042 ppp->xstate &= ~SC_COMP_RUN; 3043 ocomp = ppp->xcomp; 3044 ostate = ppp->xc_state; 3045 ppp->xcomp = cp; 3046 ppp->xc_state = state; 3047 ppp_xmit_unlock(ppp); 3048 if (ostate) { 3049 ocomp->comp_free(ostate); 3050 module_put(ocomp->owner); 3051 } 3052 err = 0; 3053 } else 3054 module_put(cp->owner); 3055 3056 } else { 3057 state = cp->decomp_alloc(ccp_option, data->length); 3058 if (state) { 3059 ppp_recv_lock(ppp); 3060 ppp->rstate &= ~SC_DECOMP_RUN; 3061 ocomp = ppp->rcomp; 3062 ostate = ppp->rc_state; 3063 ppp->rcomp = cp; 3064 ppp->rc_state = state; 3065 ppp_recv_unlock(ppp); 3066 if (ostate) { 3067 ocomp->decomp_free(ostate); 3068 module_put(ocomp->owner); 3069 } 3070 err = 0; 3071 } else 3072 module_put(cp->owner); 3073 } 3074 3075 out: 3076 return err; 3077 } 3078 3079 /* 3080 * Look at a CCP packet and update our state accordingly. 3081 * We assume the caller has the xmit or recv path locked. 3082 */ 3083 static void 3084 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound) 3085 { 3086 unsigned char *dp; 3087 int len; 3088 3089 if (!pskb_may_pull(skb, CCP_HDRLEN + 2)) 3090 return; /* no header */ 3091 dp = skb->data + 2; 3092 3093 switch (CCP_CODE(dp)) { 3094 case CCP_CONFREQ: 3095 3096 /* A ConfReq starts negotiation of compression 3097 * in one direction of transmission, 3098 * and hence brings it down...but which way? 3099 * 3100 * Remember: 3101 * A ConfReq indicates what the sender would like to receive 3102 */ 3103 if(inbound) 3104 /* He is proposing what I should send */ 3105 ppp->xstate &= ~SC_COMP_RUN; 3106 else 3107 /* I am proposing to what he should send */ 3108 ppp->rstate &= ~SC_DECOMP_RUN; 3109 3110 break; 3111 3112 case CCP_TERMREQ: 3113 case CCP_TERMACK: 3114 /* 3115 * CCP is going down, both directions of transmission 3116 */ 3117 ppp->rstate &= ~SC_DECOMP_RUN; 3118 ppp->xstate &= ~SC_COMP_RUN; 3119 break; 3120 3121 case CCP_CONFACK: 3122 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN) 3123 break; 3124 len = CCP_LENGTH(dp); 3125 if (!pskb_may_pull(skb, len + 2)) 3126 return; /* too short */ 3127 dp += CCP_HDRLEN; 3128 len -= CCP_HDRLEN; 3129 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp)) 3130 break; 3131 if (inbound) { 3132 /* we will start receiving compressed packets */ 3133 if (!ppp->rc_state) 3134 break; 3135 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len, 3136 ppp->file.index, 0, ppp->mru, ppp->debug)) { 3137 ppp->rstate |= SC_DECOMP_RUN; 3138 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR); 3139 } 3140 } else { 3141 /* we will soon start sending compressed packets */ 3142 if (!ppp->xc_state) 3143 break; 3144 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len, 3145 ppp->file.index, 0, ppp->debug)) 3146 ppp->xstate |= SC_COMP_RUN; 3147 } 3148 break; 3149 3150 case CCP_RESETACK: 3151 /* reset the [de]compressor */ 3152 if ((ppp->flags & SC_CCP_UP) == 0) 3153 break; 3154 if (inbound) { 3155 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) { 3156 ppp->rcomp->decomp_reset(ppp->rc_state); 3157 ppp->rstate &= ~SC_DC_ERROR; 3158 } 3159 } else { 3160 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN)) 3161 ppp->xcomp->comp_reset(ppp->xc_state); 3162 } 3163 break; 3164 } 3165 } 3166 3167 /* Free up compression resources. */ 3168 static void 3169 ppp_ccp_closed(struct ppp *ppp) 3170 { 3171 void *xstate, *rstate; 3172 struct compressor *xcomp, *rcomp; 3173 3174 ppp_lock(ppp); 3175 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP); 3176 ppp->xstate = 0; 3177 xcomp = ppp->xcomp; 3178 xstate = ppp->xc_state; 3179 ppp->xc_state = NULL; 3180 ppp->rstate = 0; 3181 rcomp = ppp->rcomp; 3182 rstate = ppp->rc_state; 3183 ppp->rc_state = NULL; 3184 ppp_unlock(ppp); 3185 3186 if (xstate) { 3187 xcomp->comp_free(xstate); 3188 module_put(xcomp->owner); 3189 } 3190 if (rstate) { 3191 rcomp->decomp_free(rstate); 3192 module_put(rcomp->owner); 3193 } 3194 } 3195 3196 /* List of compressors. */ 3197 static LIST_HEAD(compressor_list); 3198 static DEFINE_SPINLOCK(compressor_list_lock); 3199 3200 struct compressor_entry { 3201 struct list_head list; 3202 struct compressor *comp; 3203 }; 3204 3205 static struct compressor_entry * 3206 find_comp_entry(int proto) 3207 { 3208 struct compressor_entry *ce; 3209 3210 list_for_each_entry(ce, &compressor_list, list) { 3211 if (ce->comp->compress_proto == proto) 3212 return ce; 3213 } 3214 return NULL; 3215 } 3216 3217 /* Register a compressor */ 3218 int 3219 ppp_register_compressor(struct compressor *cp) 3220 { 3221 struct compressor_entry *ce; 3222 int ret; 3223 spin_lock(&compressor_list_lock); 3224 ret = -EEXIST; 3225 if (find_comp_entry(cp->compress_proto)) 3226 goto out; 3227 ret = -ENOMEM; 3228 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC); 3229 if (!ce) 3230 goto out; 3231 ret = 0; 3232 ce->comp = cp; 3233 list_add(&ce->list, &compressor_list); 3234 out: 3235 spin_unlock(&compressor_list_lock); 3236 return ret; 3237 } 3238 3239 /* Unregister a compressor */ 3240 void 3241 ppp_unregister_compressor(struct compressor *cp) 3242 { 3243 struct compressor_entry *ce; 3244 3245 spin_lock(&compressor_list_lock); 3246 ce = find_comp_entry(cp->compress_proto); 3247 if (ce && ce->comp == cp) { 3248 list_del(&ce->list); 3249 kfree(ce); 3250 } 3251 spin_unlock(&compressor_list_lock); 3252 } 3253 3254 /* Find a compressor. */ 3255 static struct compressor * 3256 find_compressor(int type) 3257 { 3258 struct compressor_entry *ce; 3259 struct compressor *cp = NULL; 3260 3261 spin_lock(&compressor_list_lock); 3262 ce = find_comp_entry(type); 3263 if (ce) { 3264 cp = ce->comp; 3265 if (!try_module_get(cp->owner)) 3266 cp = NULL; 3267 } 3268 spin_unlock(&compressor_list_lock); 3269 return cp; 3270 } 3271 3272 /* 3273 * Miscelleneous stuff. 3274 */ 3275 3276 static void 3277 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st) 3278 { 3279 struct slcompress *vj = ppp->vj; 3280 3281 memset(st, 0, sizeof(*st)); 3282 st->p.ppp_ipackets = ppp->stats64.rx_packets; 3283 st->p.ppp_ierrors = ppp->dev->stats.rx_errors; 3284 st->p.ppp_ibytes = ppp->stats64.rx_bytes; 3285 st->p.ppp_opackets = ppp->stats64.tx_packets; 3286 st->p.ppp_oerrors = ppp->dev->stats.tx_errors; 3287 st->p.ppp_obytes = ppp->stats64.tx_bytes; 3288 if (!vj) 3289 return; 3290 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed; 3291 st->vj.vjs_compressed = vj->sls_o_compressed; 3292 st->vj.vjs_searches = vj->sls_o_searches; 3293 st->vj.vjs_misses = vj->sls_o_misses; 3294 st->vj.vjs_errorin = vj->sls_i_error; 3295 st->vj.vjs_tossed = vj->sls_i_tossed; 3296 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed; 3297 st->vj.vjs_compressedin = vj->sls_i_compressed; 3298 } 3299 3300 /* 3301 * Stuff for handling the lists of ppp units and channels 3302 * and for initialization. 3303 */ 3304 3305 /* 3306 * Create a new ppp interface unit. Fails if it can't allocate memory 3307 * or if there is already a unit with the requested number. 3308 * unit == -1 means allocate a new number. 3309 */ 3310 static int ppp_create_interface(struct net *net, struct file *file, int *unit) 3311 { 3312 struct ppp_config conf = { 3313 .file = file, 3314 .unit = *unit, 3315 .ifname_is_set = false, 3316 }; 3317 struct net_device *dev; 3318 struct ppp *ppp; 3319 int err; 3320 3321 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup); 3322 if (!dev) { 3323 err = -ENOMEM; 3324 goto err; 3325 } 3326 dev_net_set(dev, net); 3327 dev->rtnl_link_ops = &ppp_link_ops; 3328 3329 rtnl_lock(); 3330 3331 err = ppp_dev_configure(net, dev, &conf); 3332 if (err < 0) 3333 goto err_dev; 3334 ppp = netdev_priv(dev); 3335 *unit = ppp->file.index; 3336 3337 rtnl_unlock(); 3338 3339 return 0; 3340 3341 err_dev: 3342 rtnl_unlock(); 3343 free_netdev(dev); 3344 err: 3345 return err; 3346 } 3347 3348 /* 3349 * Initialize a ppp_file structure. 3350 */ 3351 static void 3352 init_ppp_file(struct ppp_file *pf, int kind) 3353 { 3354 pf->kind = kind; 3355 skb_queue_head_init(&pf->xq); 3356 skb_queue_head_init(&pf->rq); 3357 refcount_set(&pf->refcnt, 1); 3358 init_waitqueue_head(&pf->rwait); 3359 } 3360 3361 /* 3362 * Free the memory used by a ppp unit. This is only called once 3363 * there are no channels connected to the unit and no file structs 3364 * that reference the unit. 3365 */ 3366 static void ppp_destroy_interface(struct ppp *ppp) 3367 { 3368 atomic_dec(&ppp_unit_count); 3369 3370 if (!ppp->file.dead || ppp->n_channels) { 3371 /* "can't happen" */ 3372 netdev_err(ppp->dev, "ppp: destroying ppp struct %p " 3373 "but dead=%d n_channels=%d !\n", 3374 ppp, ppp->file.dead, ppp->n_channels); 3375 return; 3376 } 3377 3378 ppp_ccp_closed(ppp); 3379 if (ppp->vj) { 3380 slhc_free(ppp->vj); 3381 ppp->vj = NULL; 3382 } 3383 skb_queue_purge(&ppp->file.xq); 3384 skb_queue_purge(&ppp->file.rq); 3385 #ifdef CONFIG_PPP_MULTILINK 3386 skb_queue_purge(&ppp->mrq); 3387 #endif /* CONFIG_PPP_MULTILINK */ 3388 #ifdef CONFIG_PPP_FILTER 3389 if (ppp->pass_filter) { 3390 bpf_prog_destroy(ppp->pass_filter); 3391 ppp->pass_filter = NULL; 3392 } 3393 3394 if (ppp->active_filter) { 3395 bpf_prog_destroy(ppp->active_filter); 3396 ppp->active_filter = NULL; 3397 } 3398 #endif /* CONFIG_PPP_FILTER */ 3399 3400 kfree_skb(ppp->xmit_pending); 3401 free_percpu(ppp->xmit_recursion); 3402 3403 free_netdev(ppp->dev); 3404 } 3405 3406 /* 3407 * Locate an existing ppp unit. 3408 * The caller should have locked the all_ppp_mutex. 3409 */ 3410 static struct ppp * 3411 ppp_find_unit(struct ppp_net *pn, int unit) 3412 { 3413 return unit_find(&pn->units_idr, unit); 3414 } 3415 3416 /* 3417 * Locate an existing ppp channel. 3418 * The caller should have locked the all_channels_lock. 3419 * First we look in the new_channels list, then in the 3420 * all_channels list. If found in the new_channels list, 3421 * we move it to the all_channels list. This is for speed 3422 * when we have a lot of channels in use. 3423 */ 3424 static struct channel * 3425 ppp_find_channel(struct ppp_net *pn, int unit) 3426 { 3427 struct channel *pch; 3428 3429 list_for_each_entry(pch, &pn->new_channels, list) { 3430 if (pch->file.index == unit) { 3431 list_move(&pch->list, &pn->all_channels); 3432 return pch; 3433 } 3434 } 3435 3436 list_for_each_entry(pch, &pn->all_channels, list) { 3437 if (pch->file.index == unit) 3438 return pch; 3439 } 3440 3441 return NULL; 3442 } 3443 3444 /* 3445 * Connect a PPP channel to a PPP interface unit. 3446 */ 3447 static int 3448 ppp_connect_channel(struct channel *pch, int unit) 3449 { 3450 struct ppp *ppp; 3451 struct ppp_net *pn; 3452 int ret = -ENXIO; 3453 int hdrlen; 3454 3455 pn = ppp_pernet(pch->chan_net); 3456 3457 mutex_lock(&pn->all_ppp_mutex); 3458 ppp = ppp_find_unit(pn, unit); 3459 if (!ppp) 3460 goto out; 3461 write_lock_bh(&pch->upl); 3462 ret = -EINVAL; 3463 if (pch->ppp || 3464 rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl))) 3465 goto outl; 3466 3467 ppp_lock(ppp); 3468 spin_lock_bh(&pch->downl); 3469 if (!pch->chan) { 3470 /* Don't connect unregistered channels */ 3471 spin_unlock_bh(&pch->downl); 3472 ppp_unlock(ppp); 3473 ret = -ENOTCONN; 3474 goto outl; 3475 } 3476 spin_unlock_bh(&pch->downl); 3477 if (pch->file.hdrlen > ppp->file.hdrlen) 3478 ppp->file.hdrlen = pch->file.hdrlen; 3479 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */ 3480 if (hdrlen > ppp->dev->hard_header_len) 3481 ppp->dev->hard_header_len = hdrlen; 3482 list_add_tail(&pch->clist, &ppp->channels); 3483 ++ppp->n_channels; 3484 pch->ppp = ppp; 3485 refcount_inc(&ppp->file.refcnt); 3486 ppp_unlock(ppp); 3487 ret = 0; 3488 3489 outl: 3490 write_unlock_bh(&pch->upl); 3491 out: 3492 mutex_unlock(&pn->all_ppp_mutex); 3493 return ret; 3494 } 3495 3496 /* 3497 * Disconnect a channel from its ppp unit. 3498 */ 3499 static int 3500 ppp_disconnect_channel(struct channel *pch) 3501 { 3502 struct ppp *ppp; 3503 int err = -EINVAL; 3504 3505 write_lock_bh(&pch->upl); 3506 ppp = pch->ppp; 3507 pch->ppp = NULL; 3508 write_unlock_bh(&pch->upl); 3509 if (ppp) { 3510 /* remove it from the ppp unit's list */ 3511 ppp_lock(ppp); 3512 list_del(&pch->clist); 3513 if (--ppp->n_channels == 0) 3514 wake_up_interruptible(&ppp->file.rwait); 3515 ppp_unlock(ppp); 3516 if (refcount_dec_and_test(&ppp->file.refcnt)) 3517 ppp_destroy_interface(ppp); 3518 err = 0; 3519 } 3520 return err; 3521 } 3522 3523 /* 3524 * Free up the resources used by a ppp channel. 3525 */ 3526 static void ppp_destroy_channel(struct channel *pch) 3527 { 3528 put_net_track(pch->chan_net, &pch->ns_tracker); 3529 pch->chan_net = NULL; 3530 3531 atomic_dec(&channel_count); 3532 3533 if (!pch->file.dead) { 3534 /* "can't happen" */ 3535 pr_err("ppp: destroying undead channel %p !\n", pch); 3536 return; 3537 } 3538 skb_queue_purge(&pch->file.xq); 3539 skb_queue_purge(&pch->file.rq); 3540 kfree(pch); 3541 } 3542 3543 static void __exit ppp_cleanup(void) 3544 { 3545 /* should never happen */ 3546 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count)) 3547 pr_err("PPP: removing module but units remain!\n"); 3548 rtnl_link_unregister(&ppp_link_ops); 3549 unregister_chrdev(PPP_MAJOR, "ppp"); 3550 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0)); 3551 class_destroy(ppp_class); 3552 unregister_pernet_device(&ppp_net_ops); 3553 } 3554 3555 /* 3556 * Units handling. Caller must protect concurrent access 3557 * by holding all_ppp_mutex 3558 */ 3559 3560 /* associate pointer with specified number */ 3561 static int unit_set(struct idr *p, void *ptr, int n) 3562 { 3563 int unit; 3564 3565 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL); 3566 if (unit == -ENOSPC) 3567 unit = -EINVAL; 3568 return unit; 3569 } 3570 3571 /* get new free unit number and associate pointer with it */ 3572 static int unit_get(struct idr *p, void *ptr, int min) 3573 { 3574 return idr_alloc(p, ptr, min, 0, GFP_KERNEL); 3575 } 3576 3577 /* put unit number back to a pool */ 3578 static void unit_put(struct idr *p, int n) 3579 { 3580 idr_remove(p, n); 3581 } 3582 3583 /* get pointer associated with the number */ 3584 static void *unit_find(struct idr *p, int n) 3585 { 3586 return idr_find(p, n); 3587 } 3588 3589 /* Module/initialization stuff */ 3590 3591 module_init(ppp_init); 3592 module_exit(ppp_cleanup); 3593 3594 EXPORT_SYMBOL(ppp_register_net_channel); 3595 EXPORT_SYMBOL(ppp_register_channel); 3596 EXPORT_SYMBOL(ppp_unregister_channel); 3597 EXPORT_SYMBOL(ppp_channel_index); 3598 EXPORT_SYMBOL(ppp_unit_number); 3599 EXPORT_SYMBOL(ppp_dev_name); 3600 EXPORT_SYMBOL(ppp_input); 3601 EXPORT_SYMBOL(ppp_input_error); 3602 EXPORT_SYMBOL(ppp_output_wakeup); 3603 EXPORT_SYMBOL(ppp_register_compressor); 3604 EXPORT_SYMBOL(ppp_unregister_compressor); 3605 MODULE_LICENSE("GPL"); 3606 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0); 3607 MODULE_ALIAS_RTNL_LINK("ppp"); 3608 MODULE_ALIAS("devname:ppp"); 3609