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