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