1/* 2 * Generic PPP layer for Linux. 3 * 4 * Copyright 1999-2002 Paul Mackerras. 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 * 11 * The generic PPP layer handles the PPP network interfaces, the 12 * /dev/ppp device, packet and VJ compression, and multilink. 13 * It talks to PPP `channels' via the interface defined in 14 * include/linux/ppp_channel.h. Channels provide the basic means for 15 * sending and receiving PPP frames on some kind of communications 16 * channel. 17 * 18 * Part of the code in this driver was inspired by the old async-only 19 * PPP driver, written by Michael Callahan and Al Longyear, and 20 * subsequently hacked by Paul Mackerras. 21 * 22 * ==FILEVERSION 20041108== 23 */ 24 25#include <linux/module.h> 26#include <linux/kernel.h> 27#include <linux/kmod.h> 28#include <linux/init.h> 29#include <linux/list.h> 30#include <linux/idr.h> 31#include <linux/netdevice.h> 32#include <linux/poll.h> 33#include <linux/ppp_defs.h> 34#include <linux/filter.h> 35#include <linux/ppp-ioctl.h> 36#include <linux/ppp_channel.h> 37#include <linux/ppp-comp.h> 38#include <linux/skbuff.h> 39#include <linux/rtnetlink.h> 40#include <linux/if_arp.h> 41#include <linux/ip.h> 42#include <linux/tcp.h> 43#include <linux/spinlock.h> 44#include <linux/rwsem.h> 45#include <linux/stddef.h> 46#include <linux/device.h> 47#include <linux/mutex.h> 48#include <linux/slab.h> 49#include <asm/unaligned.h> 50#include <net/slhc_vj.h> 51#include <linux/atomic.h> 52 53#include <linux/nsproxy.h> 54#include <net/net_namespace.h> 55#include <net/netns/generic.h> 56 57#define PPP_VERSION "2.4.2" 58 59/* 60 * Network protocols we support. 61 */ 62#define NP_IP 0 /* Internet Protocol V4 */ 63#define NP_IPV6 1 /* Internet Protocol V6 */ 64#define NP_IPX 2 /* IPX protocol */ 65#define NP_AT 3 /* Appletalk protocol */ 66#define NP_MPLS_UC 4 /* MPLS unicast */ 67#define NP_MPLS_MC 5 /* MPLS multicast */ 68#define NUM_NP 6 /* Number of NPs. */ 69 70#define MPHDRLEN 6 /* multilink protocol header length */ 71#define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */ 72 73/* 74 * An instance of /dev/ppp can be associated with either a ppp 75 * interface unit or a ppp channel. In both cases, file->private_data 76 * points to one of these. 77 */ 78struct ppp_file { 79 enum { 80 INTERFACE=1, CHANNEL 81 } kind; 82 struct sk_buff_head xq; /* pppd transmit queue */ 83 struct sk_buff_head rq; /* receive queue for pppd */ 84 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */ 85 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */ 86 int hdrlen; /* space to leave for headers */ 87 int index; /* interface unit / channel number */ 88 int dead; /* unit/channel has been shut down */ 89}; 90 91#define PF_TO_X(pf, X) container_of(pf, X, file) 92 93#define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp) 94#define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel) 95 96/* 97 * Data structure to hold primary network stats for which 98 * we want to use 64 bit storage. Other network stats 99 * are stored in dev->stats of the ppp strucute. 100 */ 101struct ppp_link_stats { 102 u64 rx_packets; 103 u64 tx_packets; 104 u64 rx_bytes; 105 u64 tx_bytes; 106}; 107 108/* 109 * Data structure describing one ppp unit. 110 * A ppp unit corresponds to a ppp network interface device 111 * and represents a multilink bundle. 112 * It can have 0 or more ppp channels connected to it. 113 */ 114struct ppp { 115 struct ppp_file file; /* stuff for read/write/poll 0 */ 116 struct file *owner; /* file that owns this unit 48 */ 117 struct list_head channels; /* list of attached channels 4c */ 118 int n_channels; /* how many channels are attached 54 */ 119 spinlock_t rlock; /* lock for receive side 58 */ 120 spinlock_t wlock; /* lock for transmit side 5c */ 121 int mru; /* max receive unit 60 */ 122 unsigned int flags; /* control bits 64 */ 123 unsigned int xstate; /* transmit state bits 68 */ 124 unsigned int rstate; /* receive state bits 6c */ 125 int debug; /* debug flags 70 */ 126 struct slcompress *vj; /* state for VJ header compression */ 127 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */ 128 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */ 129 struct compressor *xcomp; /* transmit packet compressor 8c */ 130 void *xc_state; /* its internal state 90 */ 131 struct compressor *rcomp; /* receive decompressor 94 */ 132 void *rc_state; /* its internal state 98 */ 133 unsigned long last_xmit; /* jiffies when last pkt sent 9c */ 134 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */ 135 struct net_device *dev; /* network interface device a4 */ 136 int closing; /* is device closing down? a8 */ 137#ifdef CONFIG_PPP_MULTILINK 138 int nxchan; /* next channel to send something on */ 139 u32 nxseq; /* next sequence number to send */ 140 int mrru; /* MP: max reconst. receive unit */ 141 u32 nextseq; /* MP: seq no of next packet */ 142 u32 minseq; /* MP: min of most recent seqnos */ 143 struct sk_buff_head mrq; /* MP: receive reconstruction queue */ 144#endif /* CONFIG_PPP_MULTILINK */ 145#ifdef CONFIG_PPP_FILTER 146 struct bpf_prog *pass_filter; /* filter for packets to pass */ 147 struct bpf_prog *active_filter; /* filter for pkts to reset idle */ 148#endif /* CONFIG_PPP_FILTER */ 149 struct net *ppp_net; /* the net we belong to */ 150 struct ppp_link_stats stats64; /* 64 bit network stats */ 151}; 152 153/* 154 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC, 155 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP, 156 * SC_MUST_COMP 157 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR. 158 * Bits in xstate: SC_COMP_RUN 159 */ 160#define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \ 161 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \ 162 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP) 163 164/* 165 * Private data structure for each channel. 166 * This includes the data structure used for multilink. 167 */ 168struct channel { 169 struct ppp_file file; /* stuff for read/write/poll */ 170 struct list_head list; /* link in all/new_channels list */ 171 struct ppp_channel *chan; /* public channel data structure */ 172 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */ 173 spinlock_t downl; /* protects `chan', file.xq dequeue */ 174 struct ppp *ppp; /* ppp unit we're connected to */ 175 struct net *chan_net; /* the net channel belongs to */ 176 struct list_head clist; /* link in list of channels per unit */ 177 rwlock_t upl; /* protects `ppp' */ 178#ifdef CONFIG_PPP_MULTILINK 179 u8 avail; /* flag used in multilink stuff */ 180 u8 had_frag; /* >= 1 fragments have been sent */ 181 u32 lastseq; /* MP: last sequence # received */ 182 int speed; /* speed of the corresponding ppp channel*/ 183#endif /* CONFIG_PPP_MULTILINK */ 184}; 185 186/* 187 * SMP locking issues: 188 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels 189 * list and the ppp.n_channels field, you need to take both locks 190 * before you modify them. 191 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock -> 192 * channel.downl. 193 */ 194 195static DEFINE_MUTEX(ppp_mutex); 196static atomic_t ppp_unit_count = ATOMIC_INIT(0); 197static atomic_t channel_count = ATOMIC_INIT(0); 198 199/* per-net private data for this module */ 200static int ppp_net_id __read_mostly; 201struct ppp_net { 202 /* units to ppp mapping */ 203 struct idr units_idr; 204 205 /* 206 * all_ppp_mutex protects the units_idr mapping. 207 * It also ensures that finding a ppp unit in the units_idr 208 * map and updating its file.refcnt field is atomic. 209 */ 210 struct mutex all_ppp_mutex; 211 212 /* channels */ 213 struct list_head all_channels; 214 struct list_head new_channels; 215 int last_channel_index; 216 217 /* 218 * all_channels_lock protects all_channels and 219 * last_channel_index, and the atomicity of find 220 * a channel and updating its file.refcnt field. 221 */ 222 spinlock_t all_channels_lock; 223}; 224 225/* Get the PPP protocol number from a skb */ 226#define PPP_PROTO(skb) get_unaligned_be16((skb)->data) 227 228/* We limit the length of ppp->file.rq to this (arbitrary) value */ 229#define PPP_MAX_RQLEN 32 230 231/* 232 * Maximum number of multilink fragments queued up. 233 * This has to be large enough to cope with the maximum latency of 234 * the slowest channel relative to the others. Strictly it should 235 * depend on the number of channels and their characteristics. 236 */ 237#define PPP_MP_MAX_QLEN 128 238 239/* Multilink header bits. */ 240#define B 0x80 /* this fragment begins a packet */ 241#define E 0x40 /* this fragment ends a packet */ 242 243/* Compare multilink sequence numbers (assumed to be 32 bits wide) */ 244#define seq_before(a, b) ((s32)((a) - (b)) < 0) 245#define seq_after(a, b) ((s32)((a) - (b)) > 0) 246 247/* Prototypes. */ 248static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 249 struct file *file, unsigned int cmd, unsigned long arg); 250static void ppp_xmit_process(struct ppp *ppp); 251static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb); 252static void ppp_push(struct ppp *ppp); 253static void ppp_channel_push(struct channel *pch); 254static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, 255 struct channel *pch); 256static void ppp_receive_error(struct ppp *ppp); 257static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb); 258static struct sk_buff *ppp_decompress_frame(struct ppp *ppp, 259 struct sk_buff *skb); 260#ifdef CONFIG_PPP_MULTILINK 261static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, 262 struct channel *pch); 263static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb); 264static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp); 265static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb); 266#endif /* CONFIG_PPP_MULTILINK */ 267static int ppp_set_compress(struct ppp *ppp, unsigned long arg); 268static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound); 269static void ppp_ccp_closed(struct ppp *ppp); 270static struct compressor *find_compressor(int type); 271static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st); 272static struct ppp *ppp_create_interface(struct net *net, int unit, int *retp); 273static void init_ppp_file(struct ppp_file *pf, int kind); 274static void ppp_shutdown_interface(struct ppp *ppp); 275static void ppp_destroy_interface(struct ppp *ppp); 276static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit); 277static struct channel *ppp_find_channel(struct ppp_net *pn, int unit); 278static int ppp_connect_channel(struct channel *pch, int unit); 279static int ppp_disconnect_channel(struct channel *pch); 280static void ppp_destroy_channel(struct channel *pch); 281static int unit_get(struct idr *p, void *ptr); 282static int unit_set(struct idr *p, void *ptr, int n); 283static void unit_put(struct idr *p, int n); 284static void *unit_find(struct idr *p, int n); 285 286static struct class *ppp_class; 287 288/* per net-namespace data */ 289static inline struct ppp_net *ppp_pernet(struct net *net) 290{ 291 BUG_ON(!net); 292 293 return net_generic(net, ppp_net_id); 294} 295 296/* Translates a PPP protocol number to a NP index (NP == network protocol) */ 297static inline int proto_to_npindex(int proto) 298{ 299 switch (proto) { 300 case PPP_IP: 301 return NP_IP; 302 case PPP_IPV6: 303 return NP_IPV6; 304 case PPP_IPX: 305 return NP_IPX; 306 case PPP_AT: 307 return NP_AT; 308 case PPP_MPLS_UC: 309 return NP_MPLS_UC; 310 case PPP_MPLS_MC: 311 return NP_MPLS_MC; 312 } 313 return -EINVAL; 314} 315 316/* Translates an NP index into a PPP protocol number */ 317static const int npindex_to_proto[NUM_NP] = { 318 PPP_IP, 319 PPP_IPV6, 320 PPP_IPX, 321 PPP_AT, 322 PPP_MPLS_UC, 323 PPP_MPLS_MC, 324}; 325 326/* Translates an ethertype into an NP index */ 327static inline int ethertype_to_npindex(int ethertype) 328{ 329 switch (ethertype) { 330 case ETH_P_IP: 331 return NP_IP; 332 case ETH_P_IPV6: 333 return NP_IPV6; 334 case ETH_P_IPX: 335 return NP_IPX; 336 case ETH_P_PPPTALK: 337 case ETH_P_ATALK: 338 return NP_AT; 339 case ETH_P_MPLS_UC: 340 return NP_MPLS_UC; 341 case ETH_P_MPLS_MC: 342 return NP_MPLS_MC; 343 } 344 return -1; 345} 346 347/* Translates an NP index into an ethertype */ 348static const int npindex_to_ethertype[NUM_NP] = { 349 ETH_P_IP, 350 ETH_P_IPV6, 351 ETH_P_IPX, 352 ETH_P_PPPTALK, 353 ETH_P_MPLS_UC, 354 ETH_P_MPLS_MC, 355}; 356 357/* 358 * Locking shorthand. 359 */ 360#define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock) 361#define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock) 362#define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock) 363#define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock) 364#define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \ 365 ppp_recv_lock(ppp); } while (0) 366#define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \ 367 ppp_xmit_unlock(ppp); } while (0) 368 369/* 370 * /dev/ppp device routines. 371 * The /dev/ppp device is used by pppd to control the ppp unit. 372 * It supports the read, write, ioctl and poll functions. 373 * Open instances of /dev/ppp can be in one of three states: 374 * unattached, attached to a ppp unit, or attached to a ppp channel. 375 */ 376static int ppp_open(struct inode *inode, struct file *file) 377{ 378 /* 379 * This could (should?) be enforced by the permissions on /dev/ppp. 380 */ 381 if (!capable(CAP_NET_ADMIN)) 382 return -EPERM; 383 return 0; 384} 385 386static int ppp_release(struct inode *unused, struct file *file) 387{ 388 struct ppp_file *pf = file->private_data; 389 struct ppp *ppp; 390 391 if (pf) { 392 file->private_data = NULL; 393 if (pf->kind == INTERFACE) { 394 ppp = PF_TO_PPP(pf); 395 if (file == ppp->owner) 396 ppp_shutdown_interface(ppp); 397 } 398 if (atomic_dec_and_test(&pf->refcnt)) { 399 switch (pf->kind) { 400 case INTERFACE: 401 ppp_destroy_interface(PF_TO_PPP(pf)); 402 break; 403 case CHANNEL: 404 ppp_destroy_channel(PF_TO_CHANNEL(pf)); 405 break; 406 } 407 } 408 } 409 return 0; 410} 411 412static ssize_t ppp_read(struct file *file, char __user *buf, 413 size_t count, loff_t *ppos) 414{ 415 struct ppp_file *pf = file->private_data; 416 DECLARE_WAITQUEUE(wait, current); 417 ssize_t ret; 418 struct sk_buff *skb = NULL; 419 struct iovec iov; 420 struct iov_iter to; 421 422 ret = count; 423 424 if (!pf) 425 return -ENXIO; 426 add_wait_queue(&pf->rwait, &wait); 427 for (;;) { 428 set_current_state(TASK_INTERRUPTIBLE); 429 skb = skb_dequeue(&pf->rq); 430 if (skb) 431 break; 432 ret = 0; 433 if (pf->dead) 434 break; 435 if (pf->kind == INTERFACE) { 436 /* 437 * Return 0 (EOF) on an interface that has no 438 * channels connected, unless it is looping 439 * network traffic (demand mode). 440 */ 441 struct ppp *ppp = PF_TO_PPP(pf); 442 if (ppp->n_channels == 0 && 443 (ppp->flags & SC_LOOP_TRAFFIC) == 0) 444 break; 445 } 446 ret = -EAGAIN; 447 if (file->f_flags & O_NONBLOCK) 448 break; 449 ret = -ERESTARTSYS; 450 if (signal_pending(current)) 451 break; 452 schedule(); 453 } 454 set_current_state(TASK_RUNNING); 455 remove_wait_queue(&pf->rwait, &wait); 456 457 if (!skb) 458 goto out; 459 460 ret = -EOVERFLOW; 461 if (skb->len > count) 462 goto outf; 463 ret = -EFAULT; 464 iov.iov_base = buf; 465 iov.iov_len = count; 466 iov_iter_init(&to, READ, &iov, 1, count); 467 if (skb_copy_datagram_iter(skb, 0, &to, skb->len)) 468 goto outf; 469 ret = skb->len; 470 471 outf: 472 kfree_skb(skb); 473 out: 474 return ret; 475} 476 477static ssize_t ppp_write(struct file *file, const char __user *buf, 478 size_t count, loff_t *ppos) 479{ 480 struct ppp_file *pf = file->private_data; 481 struct sk_buff *skb; 482 ssize_t ret; 483 484 if (!pf) 485 return -ENXIO; 486 ret = -ENOMEM; 487 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL); 488 if (!skb) 489 goto out; 490 skb_reserve(skb, pf->hdrlen); 491 ret = -EFAULT; 492 if (copy_from_user(skb_put(skb, count), buf, count)) { 493 kfree_skb(skb); 494 goto out; 495 } 496 497 skb_queue_tail(&pf->xq, skb); 498 499 switch (pf->kind) { 500 case INTERFACE: 501 ppp_xmit_process(PF_TO_PPP(pf)); 502 break; 503 case CHANNEL: 504 ppp_channel_push(PF_TO_CHANNEL(pf)); 505 break; 506 } 507 508 ret = count; 509 510 out: 511 return ret; 512} 513 514/* No kernel lock - fine */ 515static unsigned int ppp_poll(struct file *file, poll_table *wait) 516{ 517 struct ppp_file *pf = file->private_data; 518 unsigned int mask; 519 520 if (!pf) 521 return 0; 522 poll_wait(file, &pf->rwait, wait); 523 mask = POLLOUT | POLLWRNORM; 524 if (skb_peek(&pf->rq)) 525 mask |= POLLIN | POLLRDNORM; 526 if (pf->dead) 527 mask |= POLLHUP; 528 else if (pf->kind == INTERFACE) { 529 /* see comment in ppp_read */ 530 struct ppp *ppp = PF_TO_PPP(pf); 531 if (ppp->n_channels == 0 && 532 (ppp->flags & SC_LOOP_TRAFFIC) == 0) 533 mask |= POLLIN | POLLRDNORM; 534 } 535 536 return mask; 537} 538 539#ifdef CONFIG_PPP_FILTER 540static int get_filter(void __user *arg, struct sock_filter **p) 541{ 542 struct sock_fprog uprog; 543 struct sock_filter *code = NULL; 544 int len; 545 546 if (copy_from_user(&uprog, arg, sizeof(uprog))) 547 return -EFAULT; 548 549 if (!uprog.len) { 550 *p = NULL; 551 return 0; 552 } 553 554 len = uprog.len * sizeof(struct sock_filter); 555 code = memdup_user(uprog.filter, len); 556 if (IS_ERR(code)) 557 return PTR_ERR(code); 558 559 *p = code; 560 return uprog.len; 561} 562#endif /* CONFIG_PPP_FILTER */ 563 564static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 565{ 566 struct ppp_file *pf = file->private_data; 567 struct ppp *ppp; 568 int err = -EFAULT, val, val2, i; 569 struct ppp_idle idle; 570 struct npioctl npi; 571 int unit, cflags; 572 struct slcompress *vj; 573 void __user *argp = (void __user *)arg; 574 int __user *p = argp; 575 576 if (!pf) 577 return ppp_unattached_ioctl(current->nsproxy->net_ns, 578 pf, file, cmd, arg); 579 580 if (cmd == PPPIOCDETACH) { 581 /* 582 * We have to be careful here... if the file descriptor 583 * has been dup'd, we could have another process in the 584 * middle of a poll using the same file *, so we had 585 * better not free the interface data structures - 586 * instead we fail the ioctl. Even in this case, we 587 * shut down the interface if we are the owner of it. 588 * Actually, we should get rid of PPPIOCDETACH, userland 589 * (i.e. pppd) could achieve the same effect by closing 590 * this fd and reopening /dev/ppp. 591 */ 592 err = -EINVAL; 593 mutex_lock(&ppp_mutex); 594 if (pf->kind == INTERFACE) { 595 ppp = PF_TO_PPP(pf); 596 if (file == ppp->owner) 597 ppp_shutdown_interface(ppp); 598 } 599 if (atomic_long_read(&file->f_count) < 2) { 600 ppp_release(NULL, file); 601 err = 0; 602 } else 603 pr_warn("PPPIOCDETACH file->f_count=%ld\n", 604 atomic_long_read(&file->f_count)); 605 mutex_unlock(&ppp_mutex); 606 return err; 607 } 608 609 if (pf->kind == CHANNEL) { 610 struct channel *pch; 611 struct ppp_channel *chan; 612 613 mutex_lock(&ppp_mutex); 614 pch = PF_TO_CHANNEL(pf); 615 616 switch (cmd) { 617 case PPPIOCCONNECT: 618 if (get_user(unit, p)) 619 break; 620 err = ppp_connect_channel(pch, unit); 621 break; 622 623 case PPPIOCDISCONN: 624 err = ppp_disconnect_channel(pch); 625 break; 626 627 default: 628 down_read(&pch->chan_sem); 629 chan = pch->chan; 630 err = -ENOTTY; 631 if (chan && chan->ops->ioctl) 632 err = chan->ops->ioctl(chan, cmd, arg); 633 up_read(&pch->chan_sem); 634 } 635 mutex_unlock(&ppp_mutex); 636 return err; 637 } 638 639 if (pf->kind != INTERFACE) { 640 /* can't happen */ 641 pr_err("PPP: not interface or channel??\n"); 642 return -EINVAL; 643 } 644 645 mutex_lock(&ppp_mutex); 646 ppp = PF_TO_PPP(pf); 647 switch (cmd) { 648 case PPPIOCSMRU: 649 if (get_user(val, p)) 650 break; 651 ppp->mru = val; 652 err = 0; 653 break; 654 655 case PPPIOCSFLAGS: 656 if (get_user(val, p)) 657 break; 658 ppp_lock(ppp); 659 cflags = ppp->flags & ~val; 660#ifdef CONFIG_PPP_MULTILINK 661 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK)) 662 ppp->nextseq = 0; 663#endif 664 ppp->flags = val & SC_FLAG_BITS; 665 ppp_unlock(ppp); 666 if (cflags & SC_CCP_OPEN) 667 ppp_ccp_closed(ppp); 668 err = 0; 669 break; 670 671 case PPPIOCGFLAGS: 672 val = ppp->flags | ppp->xstate | ppp->rstate; 673 if (put_user(val, p)) 674 break; 675 err = 0; 676 break; 677 678 case PPPIOCSCOMPRESS: 679 err = ppp_set_compress(ppp, arg); 680 break; 681 682 case PPPIOCGUNIT: 683 if (put_user(ppp->file.index, p)) 684 break; 685 err = 0; 686 break; 687 688 case PPPIOCSDEBUG: 689 if (get_user(val, p)) 690 break; 691 ppp->debug = val; 692 err = 0; 693 break; 694 695 case PPPIOCGDEBUG: 696 if (put_user(ppp->debug, p)) 697 break; 698 err = 0; 699 break; 700 701 case PPPIOCGIDLE: 702 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ; 703 idle.recv_idle = (jiffies - ppp->last_recv) / HZ; 704 if (copy_to_user(argp, &idle, sizeof(idle))) 705 break; 706 err = 0; 707 break; 708 709 case PPPIOCSMAXCID: 710 if (get_user(val, p)) 711 break; 712 val2 = 15; 713 if ((val >> 16) != 0) { 714 val2 = val >> 16; 715 val &= 0xffff; 716 } 717 vj = slhc_init(val2+1, val+1); 718 if (IS_ERR(vj)) { 719 err = PTR_ERR(vj); 720 break; 721 } 722 ppp_lock(ppp); 723 if (ppp->vj) 724 slhc_free(ppp->vj); 725 ppp->vj = vj; 726 ppp_unlock(ppp); 727 err = 0; 728 break; 729 730 case PPPIOCGNPMODE: 731 case PPPIOCSNPMODE: 732 if (copy_from_user(&npi, argp, sizeof(npi))) 733 break; 734 err = proto_to_npindex(npi.protocol); 735 if (err < 0) 736 break; 737 i = err; 738 if (cmd == PPPIOCGNPMODE) { 739 err = -EFAULT; 740 npi.mode = ppp->npmode[i]; 741 if (copy_to_user(argp, &npi, sizeof(npi))) 742 break; 743 } else { 744 ppp->npmode[i] = npi.mode; 745 /* we may be able to transmit more packets now (??) */ 746 netif_wake_queue(ppp->dev); 747 } 748 err = 0; 749 break; 750 751#ifdef CONFIG_PPP_FILTER 752 case PPPIOCSPASS: 753 { 754 struct sock_filter *code; 755 756 err = get_filter(argp, &code); 757 if (err >= 0) { 758 struct bpf_prog *pass_filter = NULL; 759 struct sock_fprog_kern fprog = { 760 .len = err, 761 .filter = code, 762 }; 763 764 err = 0; 765 if (fprog.filter) 766 err = bpf_prog_create(&pass_filter, &fprog); 767 if (!err) { 768 ppp_lock(ppp); 769 if (ppp->pass_filter) 770 bpf_prog_destroy(ppp->pass_filter); 771 ppp->pass_filter = pass_filter; 772 ppp_unlock(ppp); 773 } 774 kfree(code); 775 } 776 break; 777 } 778 case PPPIOCSACTIVE: 779 { 780 struct sock_filter *code; 781 782 err = get_filter(argp, &code); 783 if (err >= 0) { 784 struct bpf_prog *active_filter = NULL; 785 struct sock_fprog_kern fprog = { 786 .len = err, 787 .filter = code, 788 }; 789 790 err = 0; 791 if (fprog.filter) 792 err = bpf_prog_create(&active_filter, &fprog); 793 if (!err) { 794 ppp_lock(ppp); 795 if (ppp->active_filter) 796 bpf_prog_destroy(ppp->active_filter); 797 ppp->active_filter = active_filter; 798 ppp_unlock(ppp); 799 } 800 kfree(code); 801 } 802 break; 803 } 804#endif /* CONFIG_PPP_FILTER */ 805 806#ifdef CONFIG_PPP_MULTILINK 807 case PPPIOCSMRRU: 808 if (get_user(val, p)) 809 break; 810 ppp_recv_lock(ppp); 811 ppp->mrru = val; 812 ppp_recv_unlock(ppp); 813 err = 0; 814 break; 815#endif /* CONFIG_PPP_MULTILINK */ 816 817 default: 818 err = -ENOTTY; 819 } 820 mutex_unlock(&ppp_mutex); 821 return err; 822} 823 824static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 825 struct file *file, unsigned int cmd, unsigned long arg) 826{ 827 int unit, err = -EFAULT; 828 struct ppp *ppp; 829 struct channel *chan; 830 struct ppp_net *pn; 831 int __user *p = (int __user *)arg; 832 833 mutex_lock(&ppp_mutex); 834 switch (cmd) { 835 case PPPIOCNEWUNIT: 836 /* Create a new ppp unit */ 837 if (get_user(unit, p)) 838 break; 839 ppp = ppp_create_interface(net, unit, &err); 840 if (!ppp) 841 break; 842 file->private_data = &ppp->file; 843 ppp->owner = file; 844 err = -EFAULT; 845 if (put_user(ppp->file.index, p)) 846 break; 847 err = 0; 848 break; 849 850 case PPPIOCATTACH: 851 /* Attach to an existing ppp unit */ 852 if (get_user(unit, p)) 853 break; 854 err = -ENXIO; 855 pn = ppp_pernet(net); 856 mutex_lock(&pn->all_ppp_mutex); 857 ppp = ppp_find_unit(pn, unit); 858 if (ppp) { 859 atomic_inc(&ppp->file.refcnt); 860 file->private_data = &ppp->file; 861 err = 0; 862 } 863 mutex_unlock(&pn->all_ppp_mutex); 864 break; 865 866 case PPPIOCATTCHAN: 867 if (get_user(unit, p)) 868 break; 869 err = -ENXIO; 870 pn = ppp_pernet(net); 871 spin_lock_bh(&pn->all_channels_lock); 872 chan = ppp_find_channel(pn, unit); 873 if (chan) { 874 atomic_inc(&chan->file.refcnt); 875 file->private_data = &chan->file; 876 err = 0; 877 } 878 spin_unlock_bh(&pn->all_channels_lock); 879 break; 880 881 default: 882 err = -ENOTTY; 883 } 884 mutex_unlock(&ppp_mutex); 885 return err; 886} 887 888static const struct file_operations ppp_device_fops = { 889 .owner = THIS_MODULE, 890 .read = ppp_read, 891 .write = ppp_write, 892 .poll = ppp_poll, 893 .unlocked_ioctl = ppp_ioctl, 894 .open = ppp_open, 895 .release = ppp_release, 896 .llseek = noop_llseek, 897}; 898 899static __net_init int ppp_init_net(struct net *net) 900{ 901 struct ppp_net *pn = net_generic(net, ppp_net_id); 902 903 idr_init(&pn->units_idr); 904 mutex_init(&pn->all_ppp_mutex); 905 906 INIT_LIST_HEAD(&pn->all_channels); 907 INIT_LIST_HEAD(&pn->new_channels); 908 909 spin_lock_init(&pn->all_channels_lock); 910 911 return 0; 912} 913 914static __net_exit void ppp_exit_net(struct net *net) 915{ 916 struct ppp_net *pn = net_generic(net, ppp_net_id); 917 918 idr_destroy(&pn->units_idr); 919} 920 921static struct pernet_operations ppp_net_ops = { 922 .init = ppp_init_net, 923 .exit = ppp_exit_net, 924 .id = &ppp_net_id, 925 .size = sizeof(struct ppp_net), 926}; 927 928#define PPP_MAJOR 108 929 930/* Called at boot time if ppp is compiled into the kernel, 931 or at module load time (from init_module) if compiled as a module. */ 932static int __init ppp_init(void) 933{ 934 int err; 935 936 pr_info("PPP generic driver version " PPP_VERSION "\n"); 937 938 err = register_pernet_device(&ppp_net_ops); 939 if (err) { 940 pr_err("failed to register PPP pernet device (%d)\n", err); 941 goto out; 942 } 943 944 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops); 945 if (err) { 946 pr_err("failed to register PPP device (%d)\n", err); 947 goto out_net; 948 } 949 950 ppp_class = class_create(THIS_MODULE, "ppp"); 951 if (IS_ERR(ppp_class)) { 952 err = PTR_ERR(ppp_class); 953 goto out_chrdev; 954 } 955 956 /* not a big deal if we fail here :-) */ 957 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp"); 958 959 return 0; 960 961out_chrdev: 962 unregister_chrdev(PPP_MAJOR, "ppp"); 963out_net: 964 unregister_pernet_device(&ppp_net_ops); 965out: 966 return err; 967} 968 969/* 970 * Network interface unit routines. 971 */ 972static netdev_tx_t 973ppp_start_xmit(struct sk_buff *skb, struct net_device *dev) 974{ 975 struct ppp *ppp = netdev_priv(dev); 976 int npi, proto; 977 unsigned char *pp; 978 979 npi = ethertype_to_npindex(ntohs(skb->protocol)); 980 if (npi < 0) 981 goto outf; 982 983 /* Drop, accept or reject the packet */ 984 switch (ppp->npmode[npi]) { 985 case NPMODE_PASS: 986 break; 987 case NPMODE_QUEUE: 988 /* it would be nice to have a way to tell the network 989 system to queue this one up for later. */ 990 goto outf; 991 case NPMODE_DROP: 992 case NPMODE_ERROR: 993 goto outf; 994 } 995 996 /* Put the 2-byte PPP protocol number on the front, 997 making sure there is room for the address and control fields. */ 998 if (skb_cow_head(skb, PPP_HDRLEN)) 999 goto outf; 1000 1001 pp = skb_push(skb, 2); 1002 proto = npindex_to_proto[npi]; 1003 put_unaligned_be16(proto, pp); 1004 1005 skb_queue_tail(&ppp->file.xq, skb); 1006 ppp_xmit_process(ppp); 1007 return NETDEV_TX_OK; 1008 1009 outf: 1010 kfree_skb(skb); 1011 ++dev->stats.tx_dropped; 1012 return NETDEV_TX_OK; 1013} 1014 1015static int 1016ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 1017{ 1018 struct ppp *ppp = netdev_priv(dev); 1019 int err = -EFAULT; 1020 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data; 1021 struct ppp_stats stats; 1022 struct ppp_comp_stats cstats; 1023 char *vers; 1024 1025 switch (cmd) { 1026 case SIOCGPPPSTATS: 1027 ppp_get_stats(ppp, &stats); 1028 if (copy_to_user(addr, &stats, sizeof(stats))) 1029 break; 1030 err = 0; 1031 break; 1032 1033 case SIOCGPPPCSTATS: 1034 memset(&cstats, 0, sizeof(cstats)); 1035 if (ppp->xc_state) 1036 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c); 1037 if (ppp->rc_state) 1038 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d); 1039 if (copy_to_user(addr, &cstats, sizeof(cstats))) 1040 break; 1041 err = 0; 1042 break; 1043 1044 case SIOCGPPPVER: 1045 vers = PPP_VERSION; 1046 if (copy_to_user(addr, vers, strlen(vers) + 1)) 1047 break; 1048 err = 0; 1049 break; 1050 1051 default: 1052 err = -EINVAL; 1053 } 1054 1055 return err; 1056} 1057 1058static struct rtnl_link_stats64* 1059ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64) 1060{ 1061 struct ppp *ppp = netdev_priv(dev); 1062 1063 ppp_recv_lock(ppp); 1064 stats64->rx_packets = ppp->stats64.rx_packets; 1065 stats64->rx_bytes = ppp->stats64.rx_bytes; 1066 ppp_recv_unlock(ppp); 1067 1068 ppp_xmit_lock(ppp); 1069 stats64->tx_packets = ppp->stats64.tx_packets; 1070 stats64->tx_bytes = ppp->stats64.tx_bytes; 1071 ppp_xmit_unlock(ppp); 1072 1073 stats64->rx_errors = dev->stats.rx_errors; 1074 stats64->tx_errors = dev->stats.tx_errors; 1075 stats64->rx_dropped = dev->stats.rx_dropped; 1076 stats64->tx_dropped = dev->stats.tx_dropped; 1077 stats64->rx_length_errors = dev->stats.rx_length_errors; 1078 1079 return stats64; 1080} 1081 1082static struct lock_class_key ppp_tx_busylock; 1083static int ppp_dev_init(struct net_device *dev) 1084{ 1085 dev->qdisc_tx_busylock = &ppp_tx_busylock; 1086 return 0; 1087} 1088 1089static const struct net_device_ops ppp_netdev_ops = { 1090 .ndo_init = ppp_dev_init, 1091 .ndo_start_xmit = ppp_start_xmit, 1092 .ndo_do_ioctl = ppp_net_ioctl, 1093 .ndo_get_stats64 = ppp_get_stats64, 1094}; 1095 1096static void ppp_setup(struct net_device *dev) 1097{ 1098 dev->netdev_ops = &ppp_netdev_ops; 1099 dev->hard_header_len = PPP_HDRLEN; 1100 dev->mtu = PPP_MRU; 1101 dev->addr_len = 0; 1102 dev->tx_queue_len = 3; 1103 dev->type = ARPHRD_PPP; 1104 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 1105 dev->features |= NETIF_F_NETNS_LOCAL; 1106 netif_keep_dst(dev); 1107} 1108 1109/* 1110 * Transmit-side routines. 1111 */ 1112 1113/* 1114 * Called to do any work queued up on the transmit side 1115 * that can now be done. 1116 */ 1117static void 1118ppp_xmit_process(struct ppp *ppp) 1119{ 1120 struct sk_buff *skb; 1121 1122 ppp_xmit_lock(ppp); 1123 if (!ppp->closing) { 1124 ppp_push(ppp); 1125 while (!ppp->xmit_pending && 1126 (skb = skb_dequeue(&ppp->file.xq))) 1127 ppp_send_frame(ppp, skb); 1128 /* If there's no work left to do, tell the core net 1129 code that we can accept some more. */ 1130 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq)) 1131 netif_wake_queue(ppp->dev); 1132 else 1133 netif_stop_queue(ppp->dev); 1134 } 1135 ppp_xmit_unlock(ppp); 1136} 1137 1138static inline struct sk_buff * 1139pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) 1140{ 1141 struct sk_buff *new_skb; 1142 int len; 1143 int new_skb_size = ppp->dev->mtu + 1144 ppp->xcomp->comp_extra + ppp->dev->hard_header_len; 1145 int compressor_skb_size = ppp->dev->mtu + 1146 ppp->xcomp->comp_extra + PPP_HDRLEN; 1147 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC); 1148 if (!new_skb) { 1149 if (net_ratelimit()) 1150 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n"); 1151 return NULL; 1152 } 1153 if (ppp->dev->hard_header_len > PPP_HDRLEN) 1154 skb_reserve(new_skb, 1155 ppp->dev->hard_header_len - PPP_HDRLEN); 1156 1157 /* compressor still expects A/C bytes in hdr */ 1158 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, 1159 new_skb->data, skb->len + 2, 1160 compressor_skb_size); 1161 if (len > 0 && (ppp->flags & SC_CCP_UP)) { 1162 consume_skb(skb); 1163 skb = new_skb; 1164 skb_put(skb, len); 1165 skb_pull(skb, 2); /* pull off A/C bytes */ 1166 } else if (len == 0) { 1167 /* didn't compress, or CCP not up yet */ 1168 consume_skb(new_skb); 1169 new_skb = skb; 1170 } else { 1171 /* 1172 * (len < 0) 1173 * MPPE requires that we do not send unencrypted 1174 * frames. The compressor will return -1 if we 1175 * should drop the frame. We cannot simply test 1176 * the compress_proto because MPPE and MPPC share 1177 * the same number. 1178 */ 1179 if (net_ratelimit()) 1180 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n"); 1181 kfree_skb(skb); 1182 consume_skb(new_skb); 1183 new_skb = NULL; 1184 } 1185 return new_skb; 1186} 1187 1188/* 1189 * Compress and send a frame. 1190 * The caller should have locked the xmit path, 1191 * and xmit_pending should be 0. 1192 */ 1193static void 1194ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) 1195{ 1196 int proto = PPP_PROTO(skb); 1197 struct sk_buff *new_skb; 1198 int len; 1199 unsigned char *cp; 1200 1201 if (proto < 0x8000) { 1202#ifdef CONFIG_PPP_FILTER 1203 /* check if we should pass this packet */ 1204 /* the filter instructions are constructed assuming 1205 a four-byte PPP header on each packet */ 1206 *skb_push(skb, 2) = 1; 1207 if (ppp->pass_filter && 1208 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 1209 if (ppp->debug & 1) 1210 netdev_printk(KERN_DEBUG, ppp->dev, 1211 "PPP: outbound frame " 1212 "not passed\n"); 1213 kfree_skb(skb); 1214 return; 1215 } 1216 /* if this packet passes the active filter, record the time */ 1217 if (!(ppp->active_filter && 1218 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 1219 ppp->last_xmit = jiffies; 1220 skb_pull(skb, 2); 1221#else 1222 /* for data packets, record the time */ 1223 ppp->last_xmit = jiffies; 1224#endif /* CONFIG_PPP_FILTER */ 1225 } 1226 1227 ++ppp->stats64.tx_packets; 1228 ppp->stats64.tx_bytes += skb->len - 2; 1229 1230 switch (proto) { 1231 case PPP_IP: 1232 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0) 1233 break; 1234 /* try to do VJ TCP header compression */ 1235 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2, 1236 GFP_ATOMIC); 1237 if (!new_skb) { 1238 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n"); 1239 goto drop; 1240 } 1241 skb_reserve(new_skb, ppp->dev->hard_header_len - 2); 1242 cp = skb->data + 2; 1243 len = slhc_compress(ppp->vj, cp, skb->len - 2, 1244 new_skb->data + 2, &cp, 1245 !(ppp->flags & SC_NO_TCP_CCID)); 1246 if (cp == skb->data + 2) { 1247 /* didn't compress */ 1248 consume_skb(new_skb); 1249 } else { 1250 if (cp[0] & SL_TYPE_COMPRESSED_TCP) { 1251 proto = PPP_VJC_COMP; 1252 cp[0] &= ~SL_TYPE_COMPRESSED_TCP; 1253 } else { 1254 proto = PPP_VJC_UNCOMP; 1255 cp[0] = skb->data[2]; 1256 } 1257 consume_skb(skb); 1258 skb = new_skb; 1259 cp = skb_put(skb, len + 2); 1260 cp[0] = 0; 1261 cp[1] = proto; 1262 } 1263 break; 1264 1265 case PPP_CCP: 1266 /* peek at outbound CCP frames */ 1267 ppp_ccp_peek(ppp, skb, 0); 1268 break; 1269 } 1270 1271 /* try to do packet compression */ 1272 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state && 1273 proto != PPP_LCP && proto != PPP_CCP) { 1274 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) { 1275 if (net_ratelimit()) 1276 netdev_err(ppp->dev, 1277 "ppp: compression required but " 1278 "down - pkt dropped.\n"); 1279 goto drop; 1280 } 1281 skb = pad_compress_skb(ppp, skb); 1282 if (!skb) 1283 goto drop; 1284 } 1285 1286 /* 1287 * If we are waiting for traffic (demand dialling), 1288 * queue it up for pppd to receive. 1289 */ 1290 if (ppp->flags & SC_LOOP_TRAFFIC) { 1291 if (ppp->file.rq.qlen > PPP_MAX_RQLEN) 1292 goto drop; 1293 skb_queue_tail(&ppp->file.rq, skb); 1294 wake_up_interruptible(&ppp->file.rwait); 1295 return; 1296 } 1297 1298 ppp->xmit_pending = skb; 1299 ppp_push(ppp); 1300 return; 1301 1302 drop: 1303 kfree_skb(skb); 1304 ++ppp->dev->stats.tx_errors; 1305} 1306 1307/* 1308 * Try to send the frame in xmit_pending. 1309 * The caller should have the xmit path locked. 1310 */ 1311static void 1312ppp_push(struct ppp *ppp) 1313{ 1314 struct list_head *list; 1315 struct channel *pch; 1316 struct sk_buff *skb = ppp->xmit_pending; 1317 1318 if (!skb) 1319 return; 1320 1321 list = &ppp->channels; 1322 if (list_empty(list)) { 1323 /* nowhere to send the packet, just drop it */ 1324 ppp->xmit_pending = NULL; 1325 kfree_skb(skb); 1326 return; 1327 } 1328 1329 if ((ppp->flags & SC_MULTILINK) == 0) { 1330 /* not doing multilink: send it down the first channel */ 1331 list = list->next; 1332 pch = list_entry(list, struct channel, clist); 1333 1334 spin_lock_bh(&pch->downl); 1335 if (pch->chan) { 1336 if (pch->chan->ops->start_xmit(pch->chan, skb)) 1337 ppp->xmit_pending = NULL; 1338 } else { 1339 /* channel got unregistered */ 1340 kfree_skb(skb); 1341 ppp->xmit_pending = NULL; 1342 } 1343 spin_unlock_bh(&pch->downl); 1344 return; 1345 } 1346 1347#ifdef CONFIG_PPP_MULTILINK 1348 /* Multilink: fragment the packet over as many links 1349 as can take the packet at the moment. */ 1350 if (!ppp_mp_explode(ppp, skb)) 1351 return; 1352#endif /* CONFIG_PPP_MULTILINK */ 1353 1354 ppp->xmit_pending = NULL; 1355 kfree_skb(skb); 1356} 1357 1358#ifdef CONFIG_PPP_MULTILINK 1359static bool mp_protocol_compress __read_mostly = true; 1360module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR); 1361MODULE_PARM_DESC(mp_protocol_compress, 1362 "compress protocol id in multilink fragments"); 1363 1364/* 1365 * Divide a packet to be transmitted into fragments and 1366 * send them out the individual links. 1367 */ 1368static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb) 1369{ 1370 int len, totlen; 1371 int i, bits, hdrlen, mtu; 1372 int flen; 1373 int navail, nfree, nzero; 1374 int nbigger; 1375 int totspeed; 1376 int totfree; 1377 unsigned char *p, *q; 1378 struct list_head *list; 1379 struct channel *pch; 1380 struct sk_buff *frag; 1381 struct ppp_channel *chan; 1382 1383 totspeed = 0; /*total bitrate of the bundle*/ 1384 nfree = 0; /* # channels which have no packet already queued */ 1385 navail = 0; /* total # of usable channels (not deregistered) */ 1386 nzero = 0; /* number of channels with zero speed associated*/ 1387 totfree = 0; /*total # of channels available and 1388 *having no queued packets before 1389 *starting the fragmentation*/ 1390 1391 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1392 i = 0; 1393 list_for_each_entry(pch, &ppp->channels, clist) { 1394 if (pch->chan) { 1395 pch->avail = 1; 1396 navail++; 1397 pch->speed = pch->chan->speed; 1398 } else { 1399 pch->avail = 0; 1400 } 1401 if (pch->avail) { 1402 if (skb_queue_empty(&pch->file.xq) || 1403 !pch->had_frag) { 1404 if (pch->speed == 0) 1405 nzero++; 1406 else 1407 totspeed += pch->speed; 1408 1409 pch->avail = 2; 1410 ++nfree; 1411 ++totfree; 1412 } 1413 if (!pch->had_frag && i < ppp->nxchan) 1414 ppp->nxchan = i; 1415 } 1416 ++i; 1417 } 1418 /* 1419 * Don't start sending this packet unless at least half of 1420 * the channels are free. This gives much better TCP 1421 * performance if we have a lot of channels. 1422 */ 1423 if (nfree == 0 || nfree < navail / 2) 1424 return 0; /* can't take now, leave it in xmit_pending */ 1425 1426 /* Do protocol field compression */ 1427 p = skb->data; 1428 len = skb->len; 1429 if (*p == 0 && mp_protocol_compress) { 1430 ++p; 1431 --len; 1432 } 1433 1434 totlen = len; 1435 nbigger = len % nfree; 1436 1437 /* skip to the channel after the one we last used 1438 and start at that one */ 1439 list = &ppp->channels; 1440 for (i = 0; i < ppp->nxchan; ++i) { 1441 list = list->next; 1442 if (list == &ppp->channels) { 1443 i = 0; 1444 break; 1445 } 1446 } 1447 1448 /* create a fragment for each channel */ 1449 bits = B; 1450 while (len > 0) { 1451 list = list->next; 1452 if (list == &ppp->channels) { 1453 i = 0; 1454 continue; 1455 } 1456 pch = list_entry(list, struct channel, clist); 1457 ++i; 1458 if (!pch->avail) 1459 continue; 1460 1461 /* 1462 * Skip this channel if it has a fragment pending already and 1463 * we haven't given a fragment to all of the free channels. 1464 */ 1465 if (pch->avail == 1) { 1466 if (nfree > 0) 1467 continue; 1468 } else { 1469 pch->avail = 1; 1470 } 1471 1472 /* check the channel's mtu and whether it is still attached. */ 1473 spin_lock_bh(&pch->downl); 1474 if (pch->chan == NULL) { 1475 /* can't use this channel, it's being deregistered */ 1476 if (pch->speed == 0) 1477 nzero--; 1478 else 1479 totspeed -= pch->speed; 1480 1481 spin_unlock_bh(&pch->downl); 1482 pch->avail = 0; 1483 totlen = len; 1484 totfree--; 1485 nfree--; 1486 if (--navail == 0) 1487 break; 1488 continue; 1489 } 1490 1491 /* 1492 *if the channel speed is not set divide 1493 *the packet evenly among the free channels; 1494 *otherwise divide it according to the speed 1495 *of the channel we are going to transmit on 1496 */ 1497 flen = len; 1498 if (nfree > 0) { 1499 if (pch->speed == 0) { 1500 flen = len/nfree; 1501 if (nbigger > 0) { 1502 flen++; 1503 nbigger--; 1504 } 1505 } else { 1506 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) / 1507 ((totspeed*totfree)/pch->speed)) - hdrlen; 1508 if (nbigger > 0) { 1509 flen += ((totfree - nzero)*pch->speed)/totspeed; 1510 nbigger -= ((totfree - nzero)*pch->speed)/ 1511 totspeed; 1512 } 1513 } 1514 nfree--; 1515 } 1516 1517 /* 1518 *check if we are on the last channel or 1519 *we exceded the length of the data to 1520 *fragment 1521 */ 1522 if ((nfree <= 0) || (flen > len)) 1523 flen = len; 1524 /* 1525 *it is not worth to tx on slow channels: 1526 *in that case from the resulting flen according to the 1527 *above formula will be equal or less than zero. 1528 *Skip the channel in this case 1529 */ 1530 if (flen <= 0) { 1531 pch->avail = 2; 1532 spin_unlock_bh(&pch->downl); 1533 continue; 1534 } 1535 1536 /* 1537 * hdrlen includes the 2-byte PPP protocol field, but the 1538 * MTU counts only the payload excluding the protocol field. 1539 * (RFC1661 Section 2) 1540 */ 1541 mtu = pch->chan->mtu - (hdrlen - 2); 1542 if (mtu < 4) 1543 mtu = 4; 1544 if (flen > mtu) 1545 flen = mtu; 1546 if (flen == len) 1547 bits |= E; 1548 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC); 1549 if (!frag) 1550 goto noskb; 1551 q = skb_put(frag, flen + hdrlen); 1552 1553 /* make the MP header */ 1554 put_unaligned_be16(PPP_MP, q); 1555 if (ppp->flags & SC_MP_XSHORTSEQ) { 1556 q[2] = bits + ((ppp->nxseq >> 8) & 0xf); 1557 q[3] = ppp->nxseq; 1558 } else { 1559 q[2] = bits; 1560 q[3] = ppp->nxseq >> 16; 1561 q[4] = ppp->nxseq >> 8; 1562 q[5] = ppp->nxseq; 1563 } 1564 1565 memcpy(q + hdrlen, p, flen); 1566 1567 /* try to send it down the channel */ 1568 chan = pch->chan; 1569 if (!skb_queue_empty(&pch->file.xq) || 1570 !chan->ops->start_xmit(chan, frag)) 1571 skb_queue_tail(&pch->file.xq, frag); 1572 pch->had_frag = 1; 1573 p += flen; 1574 len -= flen; 1575 ++ppp->nxseq; 1576 bits = 0; 1577 spin_unlock_bh(&pch->downl); 1578 } 1579 ppp->nxchan = i; 1580 1581 return 1; 1582 1583 noskb: 1584 spin_unlock_bh(&pch->downl); 1585 if (ppp->debug & 1) 1586 netdev_err(ppp->dev, "PPP: no memory (fragment)\n"); 1587 ++ppp->dev->stats.tx_errors; 1588 ++ppp->nxseq; 1589 return 1; /* abandon the frame */ 1590} 1591#endif /* CONFIG_PPP_MULTILINK */ 1592 1593/* 1594 * Try to send data out on a channel. 1595 */ 1596static void 1597ppp_channel_push(struct channel *pch) 1598{ 1599 struct sk_buff *skb; 1600 struct ppp *ppp; 1601 1602 spin_lock_bh(&pch->downl); 1603 if (pch->chan) { 1604 while (!skb_queue_empty(&pch->file.xq)) { 1605 skb = skb_dequeue(&pch->file.xq); 1606 if (!pch->chan->ops->start_xmit(pch->chan, skb)) { 1607 /* put the packet back and try again later */ 1608 skb_queue_head(&pch->file.xq, skb); 1609 break; 1610 } 1611 } 1612 } else { 1613 /* channel got deregistered */ 1614 skb_queue_purge(&pch->file.xq); 1615 } 1616 spin_unlock_bh(&pch->downl); 1617 /* see if there is anything from the attached unit to be sent */ 1618 if (skb_queue_empty(&pch->file.xq)) { 1619 read_lock_bh(&pch->upl); 1620 ppp = pch->ppp; 1621 if (ppp) 1622 ppp_xmit_process(ppp); 1623 read_unlock_bh(&pch->upl); 1624 } 1625} 1626 1627/* 1628 * Receive-side routines. 1629 */ 1630 1631struct ppp_mp_skb_parm { 1632 u32 sequence; 1633 u8 BEbits; 1634}; 1635#define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb)) 1636 1637static inline void 1638ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1639{ 1640 ppp_recv_lock(ppp); 1641 if (!ppp->closing) 1642 ppp_receive_frame(ppp, skb, pch); 1643 else 1644 kfree_skb(skb); 1645 ppp_recv_unlock(ppp); 1646} 1647 1648void 1649ppp_input(struct ppp_channel *chan, struct sk_buff *skb) 1650{ 1651 struct channel *pch = chan->ppp; 1652 int proto; 1653 1654 if (!pch) { 1655 kfree_skb(skb); 1656 return; 1657 } 1658 1659 read_lock_bh(&pch->upl); 1660 if (!pskb_may_pull(skb, 2)) { 1661 kfree_skb(skb); 1662 if (pch->ppp) { 1663 ++pch->ppp->dev->stats.rx_length_errors; 1664 ppp_receive_error(pch->ppp); 1665 } 1666 goto done; 1667 } 1668 1669 proto = PPP_PROTO(skb); 1670 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) { 1671 /* put it on the channel queue */ 1672 skb_queue_tail(&pch->file.rq, skb); 1673 /* drop old frames if queue too long */ 1674 while (pch->file.rq.qlen > PPP_MAX_RQLEN && 1675 (skb = skb_dequeue(&pch->file.rq))) 1676 kfree_skb(skb); 1677 wake_up_interruptible(&pch->file.rwait); 1678 } else { 1679 ppp_do_recv(pch->ppp, skb, pch); 1680 } 1681 1682done: 1683 read_unlock_bh(&pch->upl); 1684} 1685 1686/* Put a 0-length skb in the receive queue as an error indication */ 1687void 1688ppp_input_error(struct ppp_channel *chan, int code) 1689{ 1690 struct channel *pch = chan->ppp; 1691 struct sk_buff *skb; 1692 1693 if (!pch) 1694 return; 1695 1696 read_lock_bh(&pch->upl); 1697 if (pch->ppp) { 1698 skb = alloc_skb(0, GFP_ATOMIC); 1699 if (skb) { 1700 skb->len = 0; /* probably unnecessary */ 1701 skb->cb[0] = code; 1702 ppp_do_recv(pch->ppp, skb, pch); 1703 } 1704 } 1705 read_unlock_bh(&pch->upl); 1706} 1707 1708/* 1709 * We come in here to process a received frame. 1710 * The receive side of the ppp unit is locked. 1711 */ 1712static void 1713ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1714{ 1715 /* note: a 0-length skb is used as an error indication */ 1716 if (skb->len > 0) { 1717 skb_checksum_complete_unset(skb); 1718#ifdef CONFIG_PPP_MULTILINK 1719 /* XXX do channel-level decompression here */ 1720 if (PPP_PROTO(skb) == PPP_MP) 1721 ppp_receive_mp_frame(ppp, skb, pch); 1722 else 1723#endif /* CONFIG_PPP_MULTILINK */ 1724 ppp_receive_nonmp_frame(ppp, skb); 1725 } else { 1726 kfree_skb(skb); 1727 ppp_receive_error(ppp); 1728 } 1729} 1730 1731static void 1732ppp_receive_error(struct ppp *ppp) 1733{ 1734 ++ppp->dev->stats.rx_errors; 1735 if (ppp->vj) 1736 slhc_toss(ppp->vj); 1737} 1738 1739static void 1740ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) 1741{ 1742 struct sk_buff *ns; 1743 int proto, len, npi; 1744 1745 /* 1746 * Decompress the frame, if compressed. 1747 * Note that some decompressors need to see uncompressed frames 1748 * that come in as well as compressed frames. 1749 */ 1750 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) && 1751 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0) 1752 skb = ppp_decompress_frame(ppp, skb); 1753 1754 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR) 1755 goto err; 1756 1757 proto = PPP_PROTO(skb); 1758 switch (proto) { 1759 case PPP_VJC_COMP: 1760 /* decompress VJ compressed packets */ 1761 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 1762 goto err; 1763 1764 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) { 1765 /* copy to a new sk_buff with more tailroom */ 1766 ns = dev_alloc_skb(skb->len + 128); 1767 if (!ns) { 1768 netdev_err(ppp->dev, "PPP: no memory " 1769 "(VJ decomp)\n"); 1770 goto err; 1771 } 1772 skb_reserve(ns, 2); 1773 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len); 1774 consume_skb(skb); 1775 skb = ns; 1776 } 1777 else 1778 skb->ip_summed = CHECKSUM_NONE; 1779 1780 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2); 1781 if (len <= 0) { 1782 netdev_printk(KERN_DEBUG, ppp->dev, 1783 "PPP: VJ decompression error\n"); 1784 goto err; 1785 } 1786 len += 2; 1787 if (len > skb->len) 1788 skb_put(skb, len - skb->len); 1789 else if (len < skb->len) 1790 skb_trim(skb, len); 1791 proto = PPP_IP; 1792 break; 1793 1794 case PPP_VJC_UNCOMP: 1795 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 1796 goto err; 1797 1798 /* Until we fix the decompressor need to make sure 1799 * data portion is linear. 1800 */ 1801 if (!pskb_may_pull(skb, skb->len)) 1802 goto err; 1803 1804 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) { 1805 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n"); 1806 goto err; 1807 } 1808 proto = PPP_IP; 1809 break; 1810 1811 case PPP_CCP: 1812 ppp_ccp_peek(ppp, skb, 1); 1813 break; 1814 } 1815 1816 ++ppp->stats64.rx_packets; 1817 ppp->stats64.rx_bytes += skb->len - 2; 1818 1819 npi = proto_to_npindex(proto); 1820 if (npi < 0) { 1821 /* control or unknown frame - pass it to pppd */ 1822 skb_queue_tail(&ppp->file.rq, skb); 1823 /* limit queue length by dropping old frames */ 1824 while (ppp->file.rq.qlen > PPP_MAX_RQLEN && 1825 (skb = skb_dequeue(&ppp->file.rq))) 1826 kfree_skb(skb); 1827 /* wake up any process polling or blocking on read */ 1828 wake_up_interruptible(&ppp->file.rwait); 1829 1830 } else { 1831 /* network protocol frame - give it to the kernel */ 1832 1833#ifdef CONFIG_PPP_FILTER 1834 /* check if the packet passes the pass and active filters */ 1835 /* the filter instructions are constructed assuming 1836 a four-byte PPP header on each packet */ 1837 if (ppp->pass_filter || ppp->active_filter) { 1838 if (skb_unclone(skb, GFP_ATOMIC)) 1839 goto err; 1840 1841 *skb_push(skb, 2) = 0; 1842 if (ppp->pass_filter && 1843 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 1844 if (ppp->debug & 1) 1845 netdev_printk(KERN_DEBUG, ppp->dev, 1846 "PPP: inbound frame " 1847 "not passed\n"); 1848 kfree_skb(skb); 1849 return; 1850 } 1851 if (!(ppp->active_filter && 1852 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 1853 ppp->last_recv = jiffies; 1854 __skb_pull(skb, 2); 1855 } else 1856#endif /* CONFIG_PPP_FILTER */ 1857 ppp->last_recv = jiffies; 1858 1859 if ((ppp->dev->flags & IFF_UP) == 0 || 1860 ppp->npmode[npi] != NPMODE_PASS) { 1861 kfree_skb(skb); 1862 } else { 1863 /* chop off protocol */ 1864 skb_pull_rcsum(skb, 2); 1865 skb->dev = ppp->dev; 1866 skb->protocol = htons(npindex_to_ethertype[npi]); 1867 skb_reset_mac_header(skb); 1868 netif_rx(skb); 1869 } 1870 } 1871 return; 1872 1873 err: 1874 kfree_skb(skb); 1875 ppp_receive_error(ppp); 1876} 1877 1878static struct sk_buff * 1879ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb) 1880{ 1881 int proto = PPP_PROTO(skb); 1882 struct sk_buff *ns; 1883 int len; 1884 1885 /* Until we fix all the decompressor's need to make sure 1886 * data portion is linear. 1887 */ 1888 if (!pskb_may_pull(skb, skb->len)) 1889 goto err; 1890 1891 if (proto == PPP_COMP) { 1892 int obuff_size; 1893 1894 switch(ppp->rcomp->compress_proto) { 1895 case CI_MPPE: 1896 obuff_size = ppp->mru + PPP_HDRLEN + 1; 1897 break; 1898 default: 1899 obuff_size = ppp->mru + PPP_HDRLEN; 1900 break; 1901 } 1902 1903 ns = dev_alloc_skb(obuff_size); 1904 if (!ns) { 1905 netdev_err(ppp->dev, "ppp_decompress_frame: " 1906 "no memory\n"); 1907 goto err; 1908 } 1909 /* the decompressor still expects the A/C bytes in the hdr */ 1910 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2, 1911 skb->len + 2, ns->data, obuff_size); 1912 if (len < 0) { 1913 /* Pass the compressed frame to pppd as an 1914 error indication. */ 1915 if (len == DECOMP_FATALERROR) 1916 ppp->rstate |= SC_DC_FERROR; 1917 kfree_skb(ns); 1918 goto err; 1919 } 1920 1921 consume_skb(skb); 1922 skb = ns; 1923 skb_put(skb, len); 1924 skb_pull(skb, 2); /* pull off the A/C bytes */ 1925 1926 } else { 1927 /* Uncompressed frame - pass to decompressor so it 1928 can update its dictionary if necessary. */ 1929 if (ppp->rcomp->incomp) 1930 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2, 1931 skb->len + 2); 1932 } 1933 1934 return skb; 1935 1936 err: 1937 ppp->rstate |= SC_DC_ERROR; 1938 ppp_receive_error(ppp); 1939 return skb; 1940} 1941 1942#ifdef CONFIG_PPP_MULTILINK 1943/* 1944 * Receive a multilink frame. 1945 * We put it on the reconstruction queue and then pull off 1946 * as many completed frames as we can. 1947 */ 1948static void 1949ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1950{ 1951 u32 mask, seq; 1952 struct channel *ch; 1953 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1954 1955 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0) 1956 goto err; /* no good, throw it away */ 1957 1958 /* Decode sequence number and begin/end bits */ 1959 if (ppp->flags & SC_MP_SHORTSEQ) { 1960 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3]; 1961 mask = 0xfff; 1962 } else { 1963 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5]; 1964 mask = 0xffffff; 1965 } 1966 PPP_MP_CB(skb)->BEbits = skb->data[2]; 1967 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */ 1968 1969 /* 1970 * Do protocol ID decompression on the first fragment of each packet. 1971 */ 1972 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1)) 1973 *skb_push(skb, 1) = 0; 1974 1975 /* 1976 * Expand sequence number to 32 bits, making it as close 1977 * as possible to ppp->minseq. 1978 */ 1979 seq |= ppp->minseq & ~mask; 1980 if ((int)(ppp->minseq - seq) > (int)(mask >> 1)) 1981 seq += mask + 1; 1982 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1)) 1983 seq -= mask + 1; /* should never happen */ 1984 PPP_MP_CB(skb)->sequence = seq; 1985 pch->lastseq = seq; 1986 1987 /* 1988 * If this packet comes before the next one we were expecting, 1989 * drop it. 1990 */ 1991 if (seq_before(seq, ppp->nextseq)) { 1992 kfree_skb(skb); 1993 ++ppp->dev->stats.rx_dropped; 1994 ppp_receive_error(ppp); 1995 return; 1996 } 1997 1998 /* 1999 * Reevaluate minseq, the minimum over all channels of the 2000 * last sequence number received on each channel. Because of 2001 * the increasing sequence number rule, we know that any fragment 2002 * before `minseq' which hasn't arrived is never going to arrive. 2003 * The list of channels can't change because we have the receive 2004 * side of the ppp unit locked. 2005 */ 2006 list_for_each_entry(ch, &ppp->channels, clist) { 2007 if (seq_before(ch->lastseq, seq)) 2008 seq = ch->lastseq; 2009 } 2010 if (seq_before(ppp->minseq, seq)) 2011 ppp->minseq = seq; 2012 2013 /* Put the fragment on the reconstruction queue */ 2014 ppp_mp_insert(ppp, skb); 2015 2016 /* If the queue is getting long, don't wait any longer for packets 2017 before the start of the queue. */ 2018 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) { 2019 struct sk_buff *mskb = skb_peek(&ppp->mrq); 2020 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence)) 2021 ppp->minseq = PPP_MP_CB(mskb)->sequence; 2022 } 2023 2024 /* Pull completed packets off the queue and receive them. */ 2025 while ((skb = ppp_mp_reconstruct(ppp))) { 2026 if (pskb_may_pull(skb, 2)) 2027 ppp_receive_nonmp_frame(ppp, skb); 2028 else { 2029 ++ppp->dev->stats.rx_length_errors; 2030 kfree_skb(skb); 2031 ppp_receive_error(ppp); 2032 } 2033 } 2034 2035 return; 2036 2037 err: 2038 kfree_skb(skb); 2039 ppp_receive_error(ppp); 2040} 2041 2042/* 2043 * Insert a fragment on the MP reconstruction queue. 2044 * The queue is ordered by increasing sequence number. 2045 */ 2046static void 2047ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb) 2048{ 2049 struct sk_buff *p; 2050 struct sk_buff_head *list = &ppp->mrq; 2051 u32 seq = PPP_MP_CB(skb)->sequence; 2052 2053 /* N.B. we don't need to lock the list lock because we have the 2054 ppp unit receive-side lock. */ 2055 skb_queue_walk(list, p) { 2056 if (seq_before(seq, PPP_MP_CB(p)->sequence)) 2057 break; 2058 } 2059 __skb_queue_before(list, p, skb); 2060} 2061 2062/* 2063 * Reconstruct a packet from the MP fragment queue. 2064 * We go through increasing sequence numbers until we find a 2065 * complete packet, or we get to the sequence number for a fragment 2066 * which hasn't arrived but might still do so. 2067 */ 2068static struct sk_buff * 2069ppp_mp_reconstruct(struct ppp *ppp) 2070{ 2071 u32 seq = ppp->nextseq; 2072 u32 minseq = ppp->minseq; 2073 struct sk_buff_head *list = &ppp->mrq; 2074 struct sk_buff *p, *tmp; 2075 struct sk_buff *head, *tail; 2076 struct sk_buff *skb = NULL; 2077 int lost = 0, len = 0; 2078 2079 if (ppp->mrru == 0) /* do nothing until mrru is set */ 2080 return NULL; 2081 head = list->next; 2082 tail = NULL; 2083 skb_queue_walk_safe(list, p, tmp) { 2084 again: 2085 if (seq_before(PPP_MP_CB(p)->sequence, seq)) { 2086 /* this can't happen, anyway ignore the skb */ 2087 netdev_err(ppp->dev, "ppp_mp_reconstruct bad " 2088 "seq %u < %u\n", 2089 PPP_MP_CB(p)->sequence, seq); 2090 __skb_unlink(p, list); 2091 kfree_skb(p); 2092 continue; 2093 } 2094 if (PPP_MP_CB(p)->sequence != seq) { 2095 u32 oldseq; 2096 /* Fragment `seq' is missing. If it is after 2097 minseq, it might arrive later, so stop here. */ 2098 if (seq_after(seq, minseq)) 2099 break; 2100 /* Fragment `seq' is lost, keep going. */ 2101 lost = 1; 2102 oldseq = seq; 2103 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)? 2104 minseq + 1: PPP_MP_CB(p)->sequence; 2105 2106 if (ppp->debug & 1) 2107 netdev_printk(KERN_DEBUG, ppp->dev, 2108 "lost frag %u..%u\n", 2109 oldseq, seq-1); 2110 2111 goto again; 2112 } 2113 2114 /* 2115 * At this point we know that all the fragments from 2116 * ppp->nextseq to seq are either present or lost. 2117 * Also, there are no complete packets in the queue 2118 * that have no missing fragments and end before this 2119 * fragment. 2120 */ 2121 2122 /* B bit set indicates this fragment starts a packet */ 2123 if (PPP_MP_CB(p)->BEbits & B) { 2124 head = p; 2125 lost = 0; 2126 len = 0; 2127 } 2128 2129 len += p->len; 2130 2131 /* Got a complete packet yet? */ 2132 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) && 2133 (PPP_MP_CB(head)->BEbits & B)) { 2134 if (len > ppp->mrru + 2) { 2135 ++ppp->dev->stats.rx_length_errors; 2136 netdev_printk(KERN_DEBUG, ppp->dev, 2137 "PPP: reconstructed packet" 2138 " is too long (%d)\n", len); 2139 } else { 2140 tail = p; 2141 break; 2142 } 2143 ppp->nextseq = seq + 1; 2144 } 2145 2146 /* 2147 * If this is the ending fragment of a packet, 2148 * and we haven't found a complete valid packet yet, 2149 * we can discard up to and including this fragment. 2150 */ 2151 if (PPP_MP_CB(p)->BEbits & E) { 2152 struct sk_buff *tmp2; 2153 2154 skb_queue_reverse_walk_from_safe(list, p, tmp2) { 2155 if (ppp->debug & 1) 2156 netdev_printk(KERN_DEBUG, ppp->dev, 2157 "discarding frag %u\n", 2158 PPP_MP_CB(p)->sequence); 2159 __skb_unlink(p, list); 2160 kfree_skb(p); 2161 } 2162 head = skb_peek(list); 2163 if (!head) 2164 break; 2165 } 2166 ++seq; 2167 } 2168 2169 /* If we have a complete packet, copy it all into one skb. */ 2170 if (tail != NULL) { 2171 /* If we have discarded any fragments, 2172 signal a receive error. */ 2173 if (PPP_MP_CB(head)->sequence != ppp->nextseq) { 2174 skb_queue_walk_safe(list, p, tmp) { 2175 if (p == head) 2176 break; 2177 if (ppp->debug & 1) 2178 netdev_printk(KERN_DEBUG, ppp->dev, 2179 "discarding frag %u\n", 2180 PPP_MP_CB(p)->sequence); 2181 __skb_unlink(p, list); 2182 kfree_skb(p); 2183 } 2184 2185 if (ppp->debug & 1) 2186 netdev_printk(KERN_DEBUG, ppp->dev, 2187 " missed pkts %u..%u\n", 2188 ppp->nextseq, 2189 PPP_MP_CB(head)->sequence-1); 2190 ++ppp->dev->stats.rx_dropped; 2191 ppp_receive_error(ppp); 2192 } 2193 2194 skb = head; 2195 if (head != tail) { 2196 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list; 2197 p = skb_queue_next(list, head); 2198 __skb_unlink(skb, list); 2199 skb_queue_walk_from_safe(list, p, tmp) { 2200 __skb_unlink(p, list); 2201 *fragpp = p; 2202 p->next = NULL; 2203 fragpp = &p->next; 2204 2205 skb->len += p->len; 2206 skb->data_len += p->len; 2207 skb->truesize += p->truesize; 2208 2209 if (p == tail) 2210 break; 2211 } 2212 } else { 2213 __skb_unlink(skb, list); 2214 } 2215 2216 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1; 2217 } 2218 2219 return skb; 2220} 2221#endif /* CONFIG_PPP_MULTILINK */ 2222 2223/* 2224 * Channel interface. 2225 */ 2226 2227/* Create a new, unattached ppp channel. */ 2228int ppp_register_channel(struct ppp_channel *chan) 2229{ 2230 return ppp_register_net_channel(current->nsproxy->net_ns, chan); 2231} 2232 2233/* Create a new, unattached ppp channel for specified net. */ 2234int ppp_register_net_channel(struct net *net, struct ppp_channel *chan) 2235{ 2236 struct channel *pch; 2237 struct ppp_net *pn; 2238 2239 pch = kzalloc(sizeof(struct channel), GFP_KERNEL); 2240 if (!pch) 2241 return -ENOMEM; 2242 2243 pn = ppp_pernet(net); 2244 2245 pch->ppp = NULL; 2246 pch->chan = chan; 2247 pch->chan_net = net; 2248 chan->ppp = pch; 2249 init_ppp_file(&pch->file, CHANNEL); 2250 pch->file.hdrlen = chan->hdrlen; 2251#ifdef CONFIG_PPP_MULTILINK 2252 pch->lastseq = -1; 2253#endif /* CONFIG_PPP_MULTILINK */ 2254 init_rwsem(&pch->chan_sem); 2255 spin_lock_init(&pch->downl); 2256 rwlock_init(&pch->upl); 2257 2258 spin_lock_bh(&pn->all_channels_lock); 2259 pch->file.index = ++pn->last_channel_index; 2260 list_add(&pch->list, &pn->new_channels); 2261 atomic_inc(&channel_count); 2262 spin_unlock_bh(&pn->all_channels_lock); 2263 2264 return 0; 2265} 2266 2267/* 2268 * Return the index of a channel. 2269 */ 2270int ppp_channel_index(struct ppp_channel *chan) 2271{ 2272 struct channel *pch = chan->ppp; 2273 2274 if (pch) 2275 return pch->file.index; 2276 return -1; 2277} 2278 2279/* 2280 * Return the PPP unit number to which a channel is connected. 2281 */ 2282int ppp_unit_number(struct ppp_channel *chan) 2283{ 2284 struct channel *pch = chan->ppp; 2285 int unit = -1; 2286 2287 if (pch) { 2288 read_lock_bh(&pch->upl); 2289 if (pch->ppp) 2290 unit = pch->ppp->file.index; 2291 read_unlock_bh(&pch->upl); 2292 } 2293 return unit; 2294} 2295 2296/* 2297 * Return the PPP device interface name of a channel. 2298 */ 2299char *ppp_dev_name(struct ppp_channel *chan) 2300{ 2301 struct channel *pch = chan->ppp; 2302 char *name = NULL; 2303 2304 if (pch) { 2305 read_lock_bh(&pch->upl); 2306 if (pch->ppp && pch->ppp->dev) 2307 name = pch->ppp->dev->name; 2308 read_unlock_bh(&pch->upl); 2309 } 2310 return name; 2311} 2312 2313 2314/* 2315 * Disconnect a channel from the generic layer. 2316 * This must be called in process context. 2317 */ 2318void 2319ppp_unregister_channel(struct ppp_channel *chan) 2320{ 2321 struct channel *pch = chan->ppp; 2322 struct ppp_net *pn; 2323 2324 if (!pch) 2325 return; /* should never happen */ 2326 2327 chan->ppp = NULL; 2328 2329 /* 2330 * This ensures that we have returned from any calls into the 2331 * the channel's start_xmit or ioctl routine before we proceed. 2332 */ 2333 down_write(&pch->chan_sem); 2334 spin_lock_bh(&pch->downl); 2335 pch->chan = NULL; 2336 spin_unlock_bh(&pch->downl); 2337 up_write(&pch->chan_sem); 2338 ppp_disconnect_channel(pch); 2339 2340 pn = ppp_pernet(pch->chan_net); 2341 spin_lock_bh(&pn->all_channels_lock); 2342 list_del(&pch->list); 2343 spin_unlock_bh(&pn->all_channels_lock); 2344 2345 pch->file.dead = 1; 2346 wake_up_interruptible(&pch->file.rwait); 2347 if (atomic_dec_and_test(&pch->file.refcnt)) 2348 ppp_destroy_channel(pch); 2349} 2350 2351/* 2352 * Callback from a channel when it can accept more to transmit. 2353 * This should be called at BH/softirq level, not interrupt level. 2354 */ 2355void 2356ppp_output_wakeup(struct ppp_channel *chan) 2357{ 2358 struct channel *pch = chan->ppp; 2359 2360 if (!pch) 2361 return; 2362 ppp_channel_push(pch); 2363} 2364 2365/* 2366 * Compression control. 2367 */ 2368 2369/* Process the PPPIOCSCOMPRESS ioctl. */ 2370static int 2371ppp_set_compress(struct ppp *ppp, unsigned long arg) 2372{ 2373 int err; 2374 struct compressor *cp, *ocomp; 2375 struct ppp_option_data data; 2376 void *state, *ostate; 2377 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH]; 2378 2379 err = -EFAULT; 2380 if (copy_from_user(&data, (void __user *) arg, sizeof(data)) || 2381 (data.length <= CCP_MAX_OPTION_LENGTH && 2382 copy_from_user(ccp_option, (void __user *) data.ptr, data.length))) 2383 goto out; 2384 err = -EINVAL; 2385 if (data.length > CCP_MAX_OPTION_LENGTH || 2386 ccp_option[1] < 2 || ccp_option[1] > data.length) 2387 goto out; 2388 2389 cp = try_then_request_module( 2390 find_compressor(ccp_option[0]), 2391 "ppp-compress-%d", ccp_option[0]); 2392 if (!cp) 2393 goto out; 2394 2395 err = -ENOBUFS; 2396 if (data.transmit) { 2397 state = cp->comp_alloc(ccp_option, data.length); 2398 if (state) { 2399 ppp_xmit_lock(ppp); 2400 ppp->xstate &= ~SC_COMP_RUN; 2401 ocomp = ppp->xcomp; 2402 ostate = ppp->xc_state; 2403 ppp->xcomp = cp; 2404 ppp->xc_state = state; 2405 ppp_xmit_unlock(ppp); 2406 if (ostate) { 2407 ocomp->comp_free(ostate); 2408 module_put(ocomp->owner); 2409 } 2410 err = 0; 2411 } else 2412 module_put(cp->owner); 2413 2414 } else { 2415 state = cp->decomp_alloc(ccp_option, data.length); 2416 if (state) { 2417 ppp_recv_lock(ppp); 2418 ppp->rstate &= ~SC_DECOMP_RUN; 2419 ocomp = ppp->rcomp; 2420 ostate = ppp->rc_state; 2421 ppp->rcomp = cp; 2422 ppp->rc_state = state; 2423 ppp_recv_unlock(ppp); 2424 if (ostate) { 2425 ocomp->decomp_free(ostate); 2426 module_put(ocomp->owner); 2427 } 2428 err = 0; 2429 } else 2430 module_put(cp->owner); 2431 } 2432 2433 out: 2434 return err; 2435} 2436 2437/* 2438 * Look at a CCP packet and update our state accordingly. 2439 * We assume the caller has the xmit or recv path locked. 2440 */ 2441static void 2442ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound) 2443{ 2444 unsigned char *dp; 2445 int len; 2446 2447 if (!pskb_may_pull(skb, CCP_HDRLEN + 2)) 2448 return; /* no header */ 2449 dp = skb->data + 2; 2450 2451 switch (CCP_CODE(dp)) { 2452 case CCP_CONFREQ: 2453 2454 /* A ConfReq starts negotiation of compression 2455 * in one direction of transmission, 2456 * and hence brings it down...but which way? 2457 * 2458 * Remember: 2459 * A ConfReq indicates what the sender would like to receive 2460 */ 2461 if(inbound) 2462 /* He is proposing what I should send */ 2463 ppp->xstate &= ~SC_COMP_RUN; 2464 else 2465 /* I am proposing to what he should send */ 2466 ppp->rstate &= ~SC_DECOMP_RUN; 2467 2468 break; 2469 2470 case CCP_TERMREQ: 2471 case CCP_TERMACK: 2472 /* 2473 * CCP is going down, both directions of transmission 2474 */ 2475 ppp->rstate &= ~SC_DECOMP_RUN; 2476 ppp->xstate &= ~SC_COMP_RUN; 2477 break; 2478 2479 case CCP_CONFACK: 2480 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN) 2481 break; 2482 len = CCP_LENGTH(dp); 2483 if (!pskb_may_pull(skb, len + 2)) 2484 return; /* too short */ 2485 dp += CCP_HDRLEN; 2486 len -= CCP_HDRLEN; 2487 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp)) 2488 break; 2489 if (inbound) { 2490 /* we will start receiving compressed packets */ 2491 if (!ppp->rc_state) 2492 break; 2493 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len, 2494 ppp->file.index, 0, ppp->mru, ppp->debug)) { 2495 ppp->rstate |= SC_DECOMP_RUN; 2496 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR); 2497 } 2498 } else { 2499 /* we will soon start sending compressed packets */ 2500 if (!ppp->xc_state) 2501 break; 2502 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len, 2503 ppp->file.index, 0, ppp->debug)) 2504 ppp->xstate |= SC_COMP_RUN; 2505 } 2506 break; 2507 2508 case CCP_RESETACK: 2509 /* reset the [de]compressor */ 2510 if ((ppp->flags & SC_CCP_UP) == 0) 2511 break; 2512 if (inbound) { 2513 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) { 2514 ppp->rcomp->decomp_reset(ppp->rc_state); 2515 ppp->rstate &= ~SC_DC_ERROR; 2516 } 2517 } else { 2518 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN)) 2519 ppp->xcomp->comp_reset(ppp->xc_state); 2520 } 2521 break; 2522 } 2523} 2524 2525/* Free up compression resources. */ 2526static void 2527ppp_ccp_closed(struct ppp *ppp) 2528{ 2529 void *xstate, *rstate; 2530 struct compressor *xcomp, *rcomp; 2531 2532 ppp_lock(ppp); 2533 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP); 2534 ppp->xstate = 0; 2535 xcomp = ppp->xcomp; 2536 xstate = ppp->xc_state; 2537 ppp->xc_state = NULL; 2538 ppp->rstate = 0; 2539 rcomp = ppp->rcomp; 2540 rstate = ppp->rc_state; 2541 ppp->rc_state = NULL; 2542 ppp_unlock(ppp); 2543 2544 if (xstate) { 2545 xcomp->comp_free(xstate); 2546 module_put(xcomp->owner); 2547 } 2548 if (rstate) { 2549 rcomp->decomp_free(rstate); 2550 module_put(rcomp->owner); 2551 } 2552} 2553 2554/* List of compressors. */ 2555static LIST_HEAD(compressor_list); 2556static DEFINE_SPINLOCK(compressor_list_lock); 2557 2558struct compressor_entry { 2559 struct list_head list; 2560 struct compressor *comp; 2561}; 2562 2563static struct compressor_entry * 2564find_comp_entry(int proto) 2565{ 2566 struct compressor_entry *ce; 2567 2568 list_for_each_entry(ce, &compressor_list, list) { 2569 if (ce->comp->compress_proto == proto) 2570 return ce; 2571 } 2572 return NULL; 2573} 2574 2575/* Register a compressor */ 2576int 2577ppp_register_compressor(struct compressor *cp) 2578{ 2579 struct compressor_entry *ce; 2580 int ret; 2581 spin_lock(&compressor_list_lock); 2582 ret = -EEXIST; 2583 if (find_comp_entry(cp->compress_proto)) 2584 goto out; 2585 ret = -ENOMEM; 2586 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC); 2587 if (!ce) 2588 goto out; 2589 ret = 0; 2590 ce->comp = cp; 2591 list_add(&ce->list, &compressor_list); 2592 out: 2593 spin_unlock(&compressor_list_lock); 2594 return ret; 2595} 2596 2597/* Unregister a compressor */ 2598void 2599ppp_unregister_compressor(struct compressor *cp) 2600{ 2601 struct compressor_entry *ce; 2602 2603 spin_lock(&compressor_list_lock); 2604 ce = find_comp_entry(cp->compress_proto); 2605 if (ce && ce->comp == cp) { 2606 list_del(&ce->list); 2607 kfree(ce); 2608 } 2609 spin_unlock(&compressor_list_lock); 2610} 2611 2612/* Find a compressor. */ 2613static struct compressor * 2614find_compressor(int type) 2615{ 2616 struct compressor_entry *ce; 2617 struct compressor *cp = NULL; 2618 2619 spin_lock(&compressor_list_lock); 2620 ce = find_comp_entry(type); 2621 if (ce) { 2622 cp = ce->comp; 2623 if (!try_module_get(cp->owner)) 2624 cp = NULL; 2625 } 2626 spin_unlock(&compressor_list_lock); 2627 return cp; 2628} 2629 2630/* 2631 * Miscelleneous stuff. 2632 */ 2633 2634static void 2635ppp_get_stats(struct ppp *ppp, struct ppp_stats *st) 2636{ 2637 struct slcompress *vj = ppp->vj; 2638 2639 memset(st, 0, sizeof(*st)); 2640 st->p.ppp_ipackets = ppp->stats64.rx_packets; 2641 st->p.ppp_ierrors = ppp->dev->stats.rx_errors; 2642 st->p.ppp_ibytes = ppp->stats64.rx_bytes; 2643 st->p.ppp_opackets = ppp->stats64.tx_packets; 2644 st->p.ppp_oerrors = ppp->dev->stats.tx_errors; 2645 st->p.ppp_obytes = ppp->stats64.tx_bytes; 2646 if (!vj) 2647 return; 2648 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed; 2649 st->vj.vjs_compressed = vj->sls_o_compressed; 2650 st->vj.vjs_searches = vj->sls_o_searches; 2651 st->vj.vjs_misses = vj->sls_o_misses; 2652 st->vj.vjs_errorin = vj->sls_i_error; 2653 st->vj.vjs_tossed = vj->sls_i_tossed; 2654 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed; 2655 st->vj.vjs_compressedin = vj->sls_i_compressed; 2656} 2657 2658/* 2659 * Stuff for handling the lists of ppp units and channels 2660 * and for initialization. 2661 */ 2662 2663/* 2664 * Create a new ppp interface unit. Fails if it can't allocate memory 2665 * or if there is already a unit with the requested number. 2666 * unit == -1 means allocate a new number. 2667 */ 2668static struct ppp * 2669ppp_create_interface(struct net *net, int unit, int *retp) 2670{ 2671 struct ppp *ppp; 2672 struct ppp_net *pn; 2673 struct net_device *dev = NULL; 2674 int ret = -ENOMEM; 2675 int i; 2676 2677 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_UNKNOWN, 2678 ppp_setup); 2679 if (!dev) 2680 goto out1; 2681 2682 pn = ppp_pernet(net); 2683 2684 ppp = netdev_priv(dev); 2685 ppp->dev = dev; 2686 ppp->mru = PPP_MRU; 2687 init_ppp_file(&ppp->file, INTERFACE); 2688 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */ 2689 for (i = 0; i < NUM_NP; ++i) 2690 ppp->npmode[i] = NPMODE_PASS; 2691 INIT_LIST_HEAD(&ppp->channels); 2692 spin_lock_init(&ppp->rlock); 2693 spin_lock_init(&ppp->wlock); 2694#ifdef CONFIG_PPP_MULTILINK 2695 ppp->minseq = -1; 2696 skb_queue_head_init(&ppp->mrq); 2697#endif /* CONFIG_PPP_MULTILINK */ 2698#ifdef CONFIG_PPP_FILTER 2699 ppp->pass_filter = NULL; 2700 ppp->active_filter = NULL; 2701#endif /* CONFIG_PPP_FILTER */ 2702 2703 /* 2704 * drum roll: don't forget to set 2705 * the net device is belong to 2706 */ 2707 dev_net_set(dev, net); 2708 2709 mutex_lock(&pn->all_ppp_mutex); 2710 2711 if (unit < 0) { 2712 unit = unit_get(&pn->units_idr, ppp); 2713 if (unit < 0) { 2714 ret = unit; 2715 goto out2; 2716 } 2717 } else { 2718 ret = -EEXIST; 2719 if (unit_find(&pn->units_idr, unit)) 2720 goto out2; /* unit already exists */ 2721 /* 2722 * if caller need a specified unit number 2723 * lets try to satisfy him, otherwise -- 2724 * he should better ask us for new unit number 2725 * 2726 * NOTE: yes I know that returning EEXIST it's not 2727 * fair but at least pppd will ask us to allocate 2728 * new unit in this case so user is happy :) 2729 */ 2730 unit = unit_set(&pn->units_idr, ppp, unit); 2731 if (unit < 0) 2732 goto out2; 2733 } 2734 2735 /* Initialize the new ppp unit */ 2736 ppp->file.index = unit; 2737 sprintf(dev->name, "ppp%d", unit); 2738 2739 ret = register_netdev(dev); 2740 if (ret != 0) { 2741 unit_put(&pn->units_idr, unit); 2742 netdev_err(ppp->dev, "PPP: couldn't register device %s (%d)\n", 2743 dev->name, ret); 2744 goto out2; 2745 } 2746 2747 ppp->ppp_net = net; 2748 2749 atomic_inc(&ppp_unit_count); 2750 mutex_unlock(&pn->all_ppp_mutex); 2751 2752 *retp = 0; 2753 return ppp; 2754 2755out2: 2756 mutex_unlock(&pn->all_ppp_mutex); 2757 free_netdev(dev); 2758out1: 2759 *retp = ret; 2760 return NULL; 2761} 2762 2763/* 2764 * Initialize a ppp_file structure. 2765 */ 2766static void 2767init_ppp_file(struct ppp_file *pf, int kind) 2768{ 2769 pf->kind = kind; 2770 skb_queue_head_init(&pf->xq); 2771 skb_queue_head_init(&pf->rq); 2772 atomic_set(&pf->refcnt, 1); 2773 init_waitqueue_head(&pf->rwait); 2774} 2775 2776/* 2777 * Take down a ppp interface unit - called when the owning file 2778 * (the one that created the unit) is closed or detached. 2779 */ 2780static void ppp_shutdown_interface(struct ppp *ppp) 2781{ 2782 struct ppp_net *pn; 2783 2784 pn = ppp_pernet(ppp->ppp_net); 2785 mutex_lock(&pn->all_ppp_mutex); 2786 2787 /* This will call dev_close() for us. */ 2788 ppp_lock(ppp); 2789 if (!ppp->closing) { 2790 ppp->closing = 1; 2791 ppp_unlock(ppp); 2792 unregister_netdev(ppp->dev); 2793 unit_put(&pn->units_idr, ppp->file.index); 2794 } else 2795 ppp_unlock(ppp); 2796 2797 ppp->file.dead = 1; 2798 ppp->owner = NULL; 2799 wake_up_interruptible(&ppp->file.rwait); 2800 2801 mutex_unlock(&pn->all_ppp_mutex); 2802} 2803 2804/* 2805 * Free the memory used by a ppp unit. This is only called once 2806 * there are no channels connected to the unit and no file structs 2807 * that reference the unit. 2808 */ 2809static void ppp_destroy_interface(struct ppp *ppp) 2810{ 2811 atomic_dec(&ppp_unit_count); 2812 2813 if (!ppp->file.dead || ppp->n_channels) { 2814 /* "can't happen" */ 2815 netdev_err(ppp->dev, "ppp: destroying ppp struct %p " 2816 "but dead=%d n_channels=%d !\n", 2817 ppp, ppp->file.dead, ppp->n_channels); 2818 return; 2819 } 2820 2821 ppp_ccp_closed(ppp); 2822 if (ppp->vj) { 2823 slhc_free(ppp->vj); 2824 ppp->vj = NULL; 2825 } 2826 skb_queue_purge(&ppp->file.xq); 2827 skb_queue_purge(&ppp->file.rq); 2828#ifdef CONFIG_PPP_MULTILINK 2829 skb_queue_purge(&ppp->mrq); 2830#endif /* CONFIG_PPP_MULTILINK */ 2831#ifdef CONFIG_PPP_FILTER 2832 if (ppp->pass_filter) { 2833 bpf_prog_destroy(ppp->pass_filter); 2834 ppp->pass_filter = NULL; 2835 } 2836 2837 if (ppp->active_filter) { 2838 bpf_prog_destroy(ppp->active_filter); 2839 ppp->active_filter = NULL; 2840 } 2841#endif /* CONFIG_PPP_FILTER */ 2842 2843 kfree_skb(ppp->xmit_pending); 2844 2845 free_netdev(ppp->dev); 2846} 2847 2848/* 2849 * Locate an existing ppp unit. 2850 * The caller should have locked the all_ppp_mutex. 2851 */ 2852static struct ppp * 2853ppp_find_unit(struct ppp_net *pn, int unit) 2854{ 2855 return unit_find(&pn->units_idr, unit); 2856} 2857 2858/* 2859 * Locate an existing ppp channel. 2860 * The caller should have locked the all_channels_lock. 2861 * First we look in the new_channels list, then in the 2862 * all_channels list. If found in the new_channels list, 2863 * we move it to the all_channels list. This is for speed 2864 * when we have a lot of channels in use. 2865 */ 2866static struct channel * 2867ppp_find_channel(struct ppp_net *pn, int unit) 2868{ 2869 struct channel *pch; 2870 2871 list_for_each_entry(pch, &pn->new_channels, list) { 2872 if (pch->file.index == unit) { 2873 list_move(&pch->list, &pn->all_channels); 2874 return pch; 2875 } 2876 } 2877 2878 list_for_each_entry(pch, &pn->all_channels, list) { 2879 if (pch->file.index == unit) 2880 return pch; 2881 } 2882 2883 return NULL; 2884} 2885 2886/* 2887 * Connect a PPP channel to a PPP interface unit. 2888 */ 2889static int 2890ppp_connect_channel(struct channel *pch, int unit) 2891{ 2892 struct ppp *ppp; 2893 struct ppp_net *pn; 2894 int ret = -ENXIO; 2895 int hdrlen; 2896 2897 pn = ppp_pernet(pch->chan_net); 2898 2899 mutex_lock(&pn->all_ppp_mutex); 2900 ppp = ppp_find_unit(pn, unit); 2901 if (!ppp) 2902 goto out; 2903 write_lock_bh(&pch->upl); 2904 ret = -EINVAL; 2905 if (pch->ppp) 2906 goto outl; 2907 2908 ppp_lock(ppp); 2909 if (pch->file.hdrlen > ppp->file.hdrlen) 2910 ppp->file.hdrlen = pch->file.hdrlen; 2911 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */ 2912 if (hdrlen > ppp->dev->hard_header_len) 2913 ppp->dev->hard_header_len = hdrlen; 2914 list_add_tail(&pch->clist, &ppp->channels); 2915 ++ppp->n_channels; 2916 pch->ppp = ppp; 2917 atomic_inc(&ppp->file.refcnt); 2918 ppp_unlock(ppp); 2919 ret = 0; 2920 2921 outl: 2922 write_unlock_bh(&pch->upl); 2923 out: 2924 mutex_unlock(&pn->all_ppp_mutex); 2925 return ret; 2926} 2927 2928/* 2929 * Disconnect a channel from its ppp unit. 2930 */ 2931static int 2932ppp_disconnect_channel(struct channel *pch) 2933{ 2934 struct ppp *ppp; 2935 int err = -EINVAL; 2936 2937 write_lock_bh(&pch->upl); 2938 ppp = pch->ppp; 2939 pch->ppp = NULL; 2940 write_unlock_bh(&pch->upl); 2941 if (ppp) { 2942 /* remove it from the ppp unit's list */ 2943 ppp_lock(ppp); 2944 list_del(&pch->clist); 2945 if (--ppp->n_channels == 0) 2946 wake_up_interruptible(&ppp->file.rwait); 2947 ppp_unlock(ppp); 2948 if (atomic_dec_and_test(&ppp->file.refcnt)) 2949 ppp_destroy_interface(ppp); 2950 err = 0; 2951 } 2952 return err; 2953} 2954 2955/* 2956 * Free up the resources used by a ppp channel. 2957 */ 2958static void ppp_destroy_channel(struct channel *pch) 2959{ 2960 atomic_dec(&channel_count); 2961 2962 if (!pch->file.dead) { 2963 /* "can't happen" */ 2964 pr_err("ppp: destroying undead channel %p !\n", pch); 2965 return; 2966 } 2967 skb_queue_purge(&pch->file.xq); 2968 skb_queue_purge(&pch->file.rq); 2969 kfree(pch); 2970} 2971 2972static void __exit ppp_cleanup(void) 2973{ 2974 /* should never happen */ 2975 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count)) 2976 pr_err("PPP: removing module but units remain!\n"); 2977 unregister_chrdev(PPP_MAJOR, "ppp"); 2978 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0)); 2979 class_destroy(ppp_class); 2980 unregister_pernet_device(&ppp_net_ops); 2981} 2982 2983/* 2984 * Units handling. Caller must protect concurrent access 2985 * by holding all_ppp_mutex 2986 */ 2987 2988/* associate pointer with specified number */ 2989static int unit_set(struct idr *p, void *ptr, int n) 2990{ 2991 int unit; 2992 2993 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL); 2994 if (unit == -ENOSPC) 2995 unit = -EINVAL; 2996 return unit; 2997} 2998 2999/* get new free unit number and associate pointer with it */ 3000static int unit_get(struct idr *p, void *ptr) 3001{ 3002 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL); 3003} 3004 3005/* put unit number back to a pool */ 3006static void unit_put(struct idr *p, int n) 3007{ 3008 idr_remove(p, n); 3009} 3010 3011/* get pointer associated with the number */ 3012static void *unit_find(struct idr *p, int n) 3013{ 3014 return idr_find(p, n); 3015} 3016 3017/* Module/initialization stuff */ 3018 3019module_init(ppp_init); 3020module_exit(ppp_cleanup); 3021 3022EXPORT_SYMBOL(ppp_register_net_channel); 3023EXPORT_SYMBOL(ppp_register_channel); 3024EXPORT_SYMBOL(ppp_unregister_channel); 3025EXPORT_SYMBOL(ppp_channel_index); 3026EXPORT_SYMBOL(ppp_unit_number); 3027EXPORT_SYMBOL(ppp_dev_name); 3028EXPORT_SYMBOL(ppp_input); 3029EXPORT_SYMBOL(ppp_input_error); 3030EXPORT_SYMBOL(ppp_output_wakeup); 3031EXPORT_SYMBOL(ppp_register_compressor); 3032EXPORT_SYMBOL(ppp_unregister_compressor); 3033MODULE_LICENSE("GPL"); 3034MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0); 3035MODULE_ALIAS("devname:ppp"); 3036