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/sched/signal.h> 28 #include <linux/kmod.h> 29 #include <linux/init.h> 30 #include <linux/list.h> 31 #include <linux/idr.h> 32 #include <linux/netdevice.h> 33 #include <linux/poll.h> 34 #include <linux/ppp_defs.h> 35 #include <linux/filter.h> 36 #include <linux/ppp-ioctl.h> 37 #include <linux/ppp_channel.h> 38 #include <linux/ppp-comp.h> 39 #include <linux/skbuff.h> 40 #include <linux/rtnetlink.h> 41 #include <linux/if_arp.h> 42 #include <linux/ip.h> 43 #include <linux/tcp.h> 44 #include <linux/spinlock.h> 45 #include <linux/rwsem.h> 46 #include <linux/stddef.h> 47 #include <linux/device.h> 48 #include <linux/mutex.h> 49 #include <linux/slab.h> 50 #include <linux/file.h> 51 #include <asm/unaligned.h> 52 #include <net/slhc_vj.h> 53 #include <linux/atomic.h> 54 #include <linux/refcount.h> 55 56 #include <linux/nsproxy.h> 57 #include <net/net_namespace.h> 58 #include <net/netns/generic.h> 59 60 #define PPP_VERSION "2.4.2" 61 62 /* 63 * Network protocols we support. 64 */ 65 #define NP_IP 0 /* Internet Protocol V4 */ 66 #define NP_IPV6 1 /* Internet Protocol V6 */ 67 #define NP_IPX 2 /* IPX protocol */ 68 #define NP_AT 3 /* Appletalk protocol */ 69 #define NP_MPLS_UC 4 /* MPLS unicast */ 70 #define NP_MPLS_MC 5 /* MPLS multicast */ 71 #define NUM_NP 6 /* Number of NPs. */ 72 73 #define MPHDRLEN 6 /* multilink protocol header length */ 74 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */ 75 76 /* 77 * An instance of /dev/ppp can be associated with either a ppp 78 * interface unit or a ppp channel. In both cases, file->private_data 79 * points to one of these. 80 */ 81 struct ppp_file { 82 enum { 83 INTERFACE=1, CHANNEL 84 } kind; 85 struct sk_buff_head xq; /* pppd transmit queue */ 86 struct sk_buff_head rq; /* receive queue for pppd */ 87 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */ 88 refcount_t refcnt; /* # refs (incl /dev/ppp attached) */ 89 int hdrlen; /* space to leave for headers */ 90 int index; /* interface unit / channel number */ 91 int dead; /* unit/channel has been shut down */ 92 }; 93 94 #define PF_TO_X(pf, X) container_of(pf, X, file) 95 96 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp) 97 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel) 98 99 /* 100 * Data structure to hold primary network stats for which 101 * we want to use 64 bit storage. Other network stats 102 * are stored in dev->stats of the ppp strucute. 103 */ 104 struct ppp_link_stats { 105 u64 rx_packets; 106 u64 tx_packets; 107 u64 rx_bytes; 108 u64 tx_bytes; 109 }; 110 111 /* 112 * Data structure describing one ppp unit. 113 * A ppp unit corresponds to a ppp network interface device 114 * and represents a multilink bundle. 115 * It can have 0 or more ppp channels connected to it. 116 */ 117 struct ppp { 118 struct ppp_file file; /* stuff for read/write/poll 0 */ 119 struct file *owner; /* file that owns this unit 48 */ 120 struct list_head channels; /* list of attached channels 4c */ 121 int n_channels; /* how many channels are attached 54 */ 122 spinlock_t rlock; /* lock for receive side 58 */ 123 spinlock_t wlock; /* lock for transmit side 5c */ 124 int __percpu *xmit_recursion; /* xmit recursion detect */ 125 int mru; /* max receive unit 60 */ 126 unsigned int flags; /* control bits 64 */ 127 unsigned int xstate; /* transmit state bits 68 */ 128 unsigned int rstate; /* receive state bits 6c */ 129 int debug; /* debug flags 70 */ 130 struct slcompress *vj; /* state for VJ header compression */ 131 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */ 132 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */ 133 struct compressor *xcomp; /* transmit packet compressor 8c */ 134 void *xc_state; /* its internal state 90 */ 135 struct compressor *rcomp; /* receive decompressor 94 */ 136 void *rc_state; /* its internal state 98 */ 137 unsigned long last_xmit; /* jiffies when last pkt sent 9c */ 138 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */ 139 struct net_device *dev; /* network interface device a4 */ 140 int closing; /* is device closing down? a8 */ 141 #ifdef CONFIG_PPP_MULTILINK 142 int nxchan; /* next channel to send something on */ 143 u32 nxseq; /* next sequence number to send */ 144 int mrru; /* MP: max reconst. receive unit */ 145 u32 nextseq; /* MP: seq no of next packet */ 146 u32 minseq; /* MP: min of most recent seqnos */ 147 struct sk_buff_head mrq; /* MP: receive reconstruction queue */ 148 #endif /* CONFIG_PPP_MULTILINK */ 149 #ifdef CONFIG_PPP_FILTER 150 struct bpf_prog *pass_filter; /* filter for packets to pass */ 151 struct bpf_prog *active_filter; /* filter for pkts to reset idle */ 152 #endif /* CONFIG_PPP_FILTER */ 153 struct net *ppp_net; /* the net we belong to */ 154 struct ppp_link_stats stats64; /* 64 bit network stats */ 155 }; 156 157 /* 158 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC, 159 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP, 160 * SC_MUST_COMP 161 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR. 162 * Bits in xstate: SC_COMP_RUN 163 */ 164 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \ 165 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \ 166 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP) 167 168 /* 169 * Private data structure for each channel. 170 * This includes the data structure used for multilink. 171 */ 172 struct channel { 173 struct ppp_file file; /* stuff for read/write/poll */ 174 struct list_head list; /* link in all/new_channels list */ 175 struct ppp_channel *chan; /* public channel data structure */ 176 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */ 177 spinlock_t downl; /* protects `chan', file.xq dequeue */ 178 struct ppp *ppp; /* ppp unit we're connected to */ 179 struct net *chan_net; /* the net channel belongs to */ 180 struct list_head clist; /* link in list of channels per unit */ 181 rwlock_t upl; /* protects `ppp' */ 182 #ifdef CONFIG_PPP_MULTILINK 183 u8 avail; /* flag used in multilink stuff */ 184 u8 had_frag; /* >= 1 fragments have been sent */ 185 u32 lastseq; /* MP: last sequence # received */ 186 int speed; /* speed of the corresponding ppp channel*/ 187 #endif /* CONFIG_PPP_MULTILINK */ 188 }; 189 190 struct ppp_config { 191 struct file *file; 192 s32 unit; 193 bool ifname_is_set; 194 }; 195 196 /* 197 * SMP locking issues: 198 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels 199 * list and the ppp.n_channels field, you need to take both locks 200 * before you modify them. 201 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock -> 202 * channel.downl. 203 */ 204 205 static DEFINE_MUTEX(ppp_mutex); 206 static atomic_t ppp_unit_count = ATOMIC_INIT(0); 207 static atomic_t channel_count = ATOMIC_INIT(0); 208 209 /* per-net private data for this module */ 210 static unsigned int ppp_net_id __read_mostly; 211 struct ppp_net { 212 /* units to ppp mapping */ 213 struct idr units_idr; 214 215 /* 216 * all_ppp_mutex protects the units_idr mapping. 217 * It also ensures that finding a ppp unit in the units_idr 218 * map and updating its file.refcnt field is atomic. 219 */ 220 struct mutex all_ppp_mutex; 221 222 /* channels */ 223 struct list_head all_channels; 224 struct list_head new_channels; 225 int last_channel_index; 226 227 /* 228 * all_channels_lock protects all_channels and 229 * last_channel_index, and the atomicity of find 230 * a channel and updating its file.refcnt field. 231 */ 232 spinlock_t all_channels_lock; 233 }; 234 235 /* Get the PPP protocol number from a skb */ 236 #define PPP_PROTO(skb) get_unaligned_be16((skb)->data) 237 238 /* We limit the length of ppp->file.rq to this (arbitrary) value */ 239 #define PPP_MAX_RQLEN 32 240 241 /* 242 * Maximum number of multilink fragments queued up. 243 * This has to be large enough to cope with the maximum latency of 244 * the slowest channel relative to the others. Strictly it should 245 * depend on the number of channels and their characteristics. 246 */ 247 #define PPP_MP_MAX_QLEN 128 248 249 /* Multilink header bits. */ 250 #define B 0x80 /* this fragment begins a packet */ 251 #define E 0x40 /* this fragment ends a packet */ 252 253 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */ 254 #define seq_before(a, b) ((s32)((a) - (b)) < 0) 255 #define seq_after(a, b) ((s32)((a) - (b)) > 0) 256 257 /* Prototypes. */ 258 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 259 struct file *file, unsigned int cmd, unsigned long arg); 260 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb); 261 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb); 262 static void ppp_push(struct ppp *ppp); 263 static void ppp_channel_push(struct channel *pch); 264 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, 265 struct channel *pch); 266 static void ppp_receive_error(struct ppp *ppp); 267 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb); 268 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp, 269 struct sk_buff *skb); 270 #ifdef CONFIG_PPP_MULTILINK 271 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, 272 struct channel *pch); 273 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb); 274 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp); 275 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb); 276 #endif /* CONFIG_PPP_MULTILINK */ 277 static int ppp_set_compress(struct ppp *ppp, unsigned long arg); 278 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound); 279 static void ppp_ccp_closed(struct ppp *ppp); 280 static struct compressor *find_compressor(int type); 281 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st); 282 static int ppp_create_interface(struct net *net, struct file *file, int *unit); 283 static void init_ppp_file(struct ppp_file *pf, int kind); 284 static void ppp_destroy_interface(struct ppp *ppp); 285 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit); 286 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit); 287 static int ppp_connect_channel(struct channel *pch, int unit); 288 static int ppp_disconnect_channel(struct channel *pch); 289 static void ppp_destroy_channel(struct channel *pch); 290 static int unit_get(struct idr *p, void *ptr); 291 static int unit_set(struct idr *p, void *ptr, int n); 292 static void unit_put(struct idr *p, int n); 293 static void *unit_find(struct idr *p, int n); 294 static void ppp_setup(struct net_device *dev); 295 296 static const struct net_device_ops ppp_netdev_ops; 297 298 static struct class *ppp_class; 299 300 /* per net-namespace data */ 301 static inline struct ppp_net *ppp_pernet(struct net *net) 302 { 303 BUG_ON(!net); 304 305 return net_generic(net, ppp_net_id); 306 } 307 308 /* Translates a PPP protocol number to a NP index (NP == network protocol) */ 309 static inline int proto_to_npindex(int proto) 310 { 311 switch (proto) { 312 case PPP_IP: 313 return NP_IP; 314 case PPP_IPV6: 315 return NP_IPV6; 316 case PPP_IPX: 317 return NP_IPX; 318 case PPP_AT: 319 return NP_AT; 320 case PPP_MPLS_UC: 321 return NP_MPLS_UC; 322 case PPP_MPLS_MC: 323 return NP_MPLS_MC; 324 } 325 return -EINVAL; 326 } 327 328 /* Translates an NP index into a PPP protocol number */ 329 static const int npindex_to_proto[NUM_NP] = { 330 PPP_IP, 331 PPP_IPV6, 332 PPP_IPX, 333 PPP_AT, 334 PPP_MPLS_UC, 335 PPP_MPLS_MC, 336 }; 337 338 /* Translates an ethertype into an NP index */ 339 static inline int ethertype_to_npindex(int ethertype) 340 { 341 switch (ethertype) { 342 case ETH_P_IP: 343 return NP_IP; 344 case ETH_P_IPV6: 345 return NP_IPV6; 346 case ETH_P_IPX: 347 return NP_IPX; 348 case ETH_P_PPPTALK: 349 case ETH_P_ATALK: 350 return NP_AT; 351 case ETH_P_MPLS_UC: 352 return NP_MPLS_UC; 353 case ETH_P_MPLS_MC: 354 return NP_MPLS_MC; 355 } 356 return -1; 357 } 358 359 /* Translates an NP index into an ethertype */ 360 static const int npindex_to_ethertype[NUM_NP] = { 361 ETH_P_IP, 362 ETH_P_IPV6, 363 ETH_P_IPX, 364 ETH_P_PPPTALK, 365 ETH_P_MPLS_UC, 366 ETH_P_MPLS_MC, 367 }; 368 369 /* 370 * Locking shorthand. 371 */ 372 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock) 373 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock) 374 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock) 375 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock) 376 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \ 377 ppp_recv_lock(ppp); } while (0) 378 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \ 379 ppp_xmit_unlock(ppp); } while (0) 380 381 /* 382 * /dev/ppp device routines. 383 * The /dev/ppp device is used by pppd to control the ppp unit. 384 * It supports the read, write, ioctl and poll functions. 385 * Open instances of /dev/ppp can be in one of three states: 386 * unattached, attached to a ppp unit, or attached to a ppp channel. 387 */ 388 static int ppp_open(struct inode *inode, struct file *file) 389 { 390 /* 391 * This could (should?) be enforced by the permissions on /dev/ppp. 392 */ 393 if (!ns_capable(file->f_cred->user_ns, CAP_NET_ADMIN)) 394 return -EPERM; 395 return 0; 396 } 397 398 static int ppp_release(struct inode *unused, struct file *file) 399 { 400 struct ppp_file *pf = file->private_data; 401 struct ppp *ppp; 402 403 if (pf) { 404 file->private_data = NULL; 405 if (pf->kind == INTERFACE) { 406 ppp = PF_TO_PPP(pf); 407 rtnl_lock(); 408 if (file == ppp->owner) 409 unregister_netdevice(ppp->dev); 410 rtnl_unlock(); 411 } 412 if (refcount_dec_and_test(&pf->refcnt)) { 413 switch (pf->kind) { 414 case INTERFACE: 415 ppp_destroy_interface(PF_TO_PPP(pf)); 416 break; 417 case CHANNEL: 418 ppp_destroy_channel(PF_TO_CHANNEL(pf)); 419 break; 420 } 421 } 422 } 423 return 0; 424 } 425 426 static ssize_t ppp_read(struct file *file, char __user *buf, 427 size_t count, loff_t *ppos) 428 { 429 struct ppp_file *pf = file->private_data; 430 DECLARE_WAITQUEUE(wait, current); 431 ssize_t ret; 432 struct sk_buff *skb = NULL; 433 struct iovec iov; 434 struct iov_iter to; 435 436 ret = count; 437 438 if (!pf) 439 return -ENXIO; 440 add_wait_queue(&pf->rwait, &wait); 441 for (;;) { 442 set_current_state(TASK_INTERRUPTIBLE); 443 skb = skb_dequeue(&pf->rq); 444 if (skb) 445 break; 446 ret = 0; 447 if (pf->dead) 448 break; 449 if (pf->kind == INTERFACE) { 450 /* 451 * Return 0 (EOF) on an interface that has no 452 * channels connected, unless it is looping 453 * network traffic (demand mode). 454 */ 455 struct ppp *ppp = PF_TO_PPP(pf); 456 457 ppp_recv_lock(ppp); 458 if (ppp->n_channels == 0 && 459 (ppp->flags & SC_LOOP_TRAFFIC) == 0) { 460 ppp_recv_unlock(ppp); 461 break; 462 } 463 ppp_recv_unlock(ppp); 464 } 465 ret = -EAGAIN; 466 if (file->f_flags & O_NONBLOCK) 467 break; 468 ret = -ERESTARTSYS; 469 if (signal_pending(current)) 470 break; 471 schedule(); 472 } 473 set_current_state(TASK_RUNNING); 474 remove_wait_queue(&pf->rwait, &wait); 475 476 if (!skb) 477 goto out; 478 479 ret = -EOVERFLOW; 480 if (skb->len > count) 481 goto outf; 482 ret = -EFAULT; 483 iov.iov_base = buf; 484 iov.iov_len = count; 485 iov_iter_init(&to, READ, &iov, 1, count); 486 if (skb_copy_datagram_iter(skb, 0, &to, skb->len)) 487 goto outf; 488 ret = skb->len; 489 490 outf: 491 kfree_skb(skb); 492 out: 493 return ret; 494 } 495 496 static ssize_t ppp_write(struct file *file, const char __user *buf, 497 size_t count, loff_t *ppos) 498 { 499 struct ppp_file *pf = file->private_data; 500 struct sk_buff *skb; 501 ssize_t ret; 502 503 if (!pf) 504 return -ENXIO; 505 ret = -ENOMEM; 506 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL); 507 if (!skb) 508 goto out; 509 skb_reserve(skb, pf->hdrlen); 510 ret = -EFAULT; 511 if (copy_from_user(skb_put(skb, count), buf, count)) { 512 kfree_skb(skb); 513 goto out; 514 } 515 516 switch (pf->kind) { 517 case INTERFACE: 518 ppp_xmit_process(PF_TO_PPP(pf), skb); 519 break; 520 case CHANNEL: 521 skb_queue_tail(&pf->xq, skb); 522 ppp_channel_push(PF_TO_CHANNEL(pf)); 523 break; 524 } 525 526 ret = count; 527 528 out: 529 return ret; 530 } 531 532 /* No kernel lock - fine */ 533 static __poll_t ppp_poll(struct file *file, poll_table *wait) 534 { 535 struct ppp_file *pf = file->private_data; 536 __poll_t mask; 537 538 if (!pf) 539 return 0; 540 poll_wait(file, &pf->rwait, wait); 541 mask = EPOLLOUT | EPOLLWRNORM; 542 if (skb_peek(&pf->rq)) 543 mask |= EPOLLIN | EPOLLRDNORM; 544 if (pf->dead) 545 mask |= EPOLLHUP; 546 else if (pf->kind == INTERFACE) { 547 /* see comment in ppp_read */ 548 struct ppp *ppp = PF_TO_PPP(pf); 549 550 ppp_recv_lock(ppp); 551 if (ppp->n_channels == 0 && 552 (ppp->flags & SC_LOOP_TRAFFIC) == 0) 553 mask |= EPOLLIN | EPOLLRDNORM; 554 ppp_recv_unlock(ppp); 555 } 556 557 return mask; 558 } 559 560 #ifdef CONFIG_PPP_FILTER 561 static int get_filter(void __user *arg, struct sock_filter **p) 562 { 563 struct sock_fprog uprog; 564 struct sock_filter *code = NULL; 565 int len; 566 567 if (copy_from_user(&uprog, arg, sizeof(uprog))) 568 return -EFAULT; 569 570 if (!uprog.len) { 571 *p = NULL; 572 return 0; 573 } 574 575 len = uprog.len * sizeof(struct sock_filter); 576 code = memdup_user(uprog.filter, len); 577 if (IS_ERR(code)) 578 return PTR_ERR(code); 579 580 *p = code; 581 return uprog.len; 582 } 583 #endif /* CONFIG_PPP_FILTER */ 584 585 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 586 { 587 struct ppp_file *pf; 588 struct ppp *ppp; 589 int err = -EFAULT, val, val2, i; 590 struct ppp_idle idle; 591 struct npioctl npi; 592 int unit, cflags; 593 struct slcompress *vj; 594 void __user *argp = (void __user *)arg; 595 int __user *p = argp; 596 597 mutex_lock(&ppp_mutex); 598 599 pf = file->private_data; 600 if (!pf) { 601 err = ppp_unattached_ioctl(current->nsproxy->net_ns, 602 pf, file, cmd, arg); 603 goto out; 604 } 605 606 if (cmd == PPPIOCDETACH) { 607 /* 608 * PPPIOCDETACH is no longer supported as it was heavily broken, 609 * and is only known to have been used by pppd older than 610 * ppp-2.4.2 (released November 2003). 611 */ 612 pr_warn_once("%s (%d) used obsolete PPPIOCDETACH ioctl\n", 613 current->comm, current->pid); 614 err = -EINVAL; 615 goto out; 616 } 617 618 if (pf->kind == CHANNEL) { 619 struct channel *pch; 620 struct ppp_channel *chan; 621 622 pch = PF_TO_CHANNEL(pf); 623 624 switch (cmd) { 625 case PPPIOCCONNECT: 626 if (get_user(unit, p)) 627 break; 628 err = ppp_connect_channel(pch, unit); 629 break; 630 631 case PPPIOCDISCONN: 632 err = ppp_disconnect_channel(pch); 633 break; 634 635 default: 636 down_read(&pch->chan_sem); 637 chan = pch->chan; 638 err = -ENOTTY; 639 if (chan && chan->ops->ioctl) 640 err = chan->ops->ioctl(chan, cmd, arg); 641 up_read(&pch->chan_sem); 642 } 643 goto out; 644 } 645 646 if (pf->kind != INTERFACE) { 647 /* can't happen */ 648 pr_err("PPP: not interface or channel??\n"); 649 err = -EINVAL; 650 goto out; 651 } 652 653 ppp = PF_TO_PPP(pf); 654 switch (cmd) { 655 case PPPIOCSMRU: 656 if (get_user(val, p)) 657 break; 658 ppp->mru = val; 659 err = 0; 660 break; 661 662 case PPPIOCSFLAGS: 663 if (get_user(val, p)) 664 break; 665 ppp_lock(ppp); 666 cflags = ppp->flags & ~val; 667 #ifdef CONFIG_PPP_MULTILINK 668 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK)) 669 ppp->nextseq = 0; 670 #endif 671 ppp->flags = val & SC_FLAG_BITS; 672 ppp_unlock(ppp); 673 if (cflags & SC_CCP_OPEN) 674 ppp_ccp_closed(ppp); 675 err = 0; 676 break; 677 678 case PPPIOCGFLAGS: 679 val = ppp->flags | ppp->xstate | ppp->rstate; 680 if (put_user(val, p)) 681 break; 682 err = 0; 683 break; 684 685 case PPPIOCSCOMPRESS: 686 err = ppp_set_compress(ppp, arg); 687 break; 688 689 case PPPIOCGUNIT: 690 if (put_user(ppp->file.index, p)) 691 break; 692 err = 0; 693 break; 694 695 case PPPIOCSDEBUG: 696 if (get_user(val, p)) 697 break; 698 ppp->debug = val; 699 err = 0; 700 break; 701 702 case PPPIOCGDEBUG: 703 if (put_user(ppp->debug, p)) 704 break; 705 err = 0; 706 break; 707 708 case PPPIOCGIDLE: 709 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ; 710 idle.recv_idle = (jiffies - ppp->last_recv) / HZ; 711 if (copy_to_user(argp, &idle, sizeof(idle))) 712 break; 713 err = 0; 714 break; 715 716 case PPPIOCSMAXCID: 717 if (get_user(val, p)) 718 break; 719 val2 = 15; 720 if ((val >> 16) != 0) { 721 val2 = val >> 16; 722 val &= 0xffff; 723 } 724 vj = slhc_init(val2+1, val+1); 725 if (IS_ERR(vj)) { 726 err = PTR_ERR(vj); 727 break; 728 } 729 ppp_lock(ppp); 730 if (ppp->vj) 731 slhc_free(ppp->vj); 732 ppp->vj = vj; 733 ppp_unlock(ppp); 734 err = 0; 735 break; 736 737 case PPPIOCGNPMODE: 738 case PPPIOCSNPMODE: 739 if (copy_from_user(&npi, argp, sizeof(npi))) 740 break; 741 err = proto_to_npindex(npi.protocol); 742 if (err < 0) 743 break; 744 i = err; 745 if (cmd == PPPIOCGNPMODE) { 746 err = -EFAULT; 747 npi.mode = ppp->npmode[i]; 748 if (copy_to_user(argp, &npi, sizeof(npi))) 749 break; 750 } else { 751 ppp->npmode[i] = npi.mode; 752 /* we may be able to transmit more packets now (??) */ 753 netif_wake_queue(ppp->dev); 754 } 755 err = 0; 756 break; 757 758 #ifdef CONFIG_PPP_FILTER 759 case PPPIOCSPASS: 760 { 761 struct sock_filter *code; 762 763 err = get_filter(argp, &code); 764 if (err >= 0) { 765 struct bpf_prog *pass_filter = NULL; 766 struct sock_fprog_kern fprog = { 767 .len = err, 768 .filter = code, 769 }; 770 771 err = 0; 772 if (fprog.filter) 773 err = bpf_prog_create(&pass_filter, &fprog); 774 if (!err) { 775 ppp_lock(ppp); 776 if (ppp->pass_filter) 777 bpf_prog_destroy(ppp->pass_filter); 778 ppp->pass_filter = pass_filter; 779 ppp_unlock(ppp); 780 } 781 kfree(code); 782 } 783 break; 784 } 785 case PPPIOCSACTIVE: 786 { 787 struct sock_filter *code; 788 789 err = get_filter(argp, &code); 790 if (err >= 0) { 791 struct bpf_prog *active_filter = NULL; 792 struct sock_fprog_kern fprog = { 793 .len = err, 794 .filter = code, 795 }; 796 797 err = 0; 798 if (fprog.filter) 799 err = bpf_prog_create(&active_filter, &fprog); 800 if (!err) { 801 ppp_lock(ppp); 802 if (ppp->active_filter) 803 bpf_prog_destroy(ppp->active_filter); 804 ppp->active_filter = active_filter; 805 ppp_unlock(ppp); 806 } 807 kfree(code); 808 } 809 break; 810 } 811 #endif /* CONFIG_PPP_FILTER */ 812 813 #ifdef CONFIG_PPP_MULTILINK 814 case PPPIOCSMRRU: 815 if (get_user(val, p)) 816 break; 817 ppp_recv_lock(ppp); 818 ppp->mrru = val; 819 ppp_recv_unlock(ppp); 820 err = 0; 821 break; 822 #endif /* CONFIG_PPP_MULTILINK */ 823 824 default: 825 err = -ENOTTY; 826 } 827 828 out: 829 mutex_unlock(&ppp_mutex); 830 831 return err; 832 } 833 834 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 835 struct file *file, unsigned int cmd, unsigned long arg) 836 { 837 int unit, err = -EFAULT; 838 struct ppp *ppp; 839 struct channel *chan; 840 struct ppp_net *pn; 841 int __user *p = (int __user *)arg; 842 843 switch (cmd) { 844 case PPPIOCNEWUNIT: 845 /* Create a new ppp unit */ 846 if (get_user(unit, p)) 847 break; 848 err = ppp_create_interface(net, file, &unit); 849 if (err < 0) 850 break; 851 852 err = -EFAULT; 853 if (put_user(unit, p)) 854 break; 855 err = 0; 856 break; 857 858 case PPPIOCATTACH: 859 /* Attach to an existing ppp unit */ 860 if (get_user(unit, p)) 861 break; 862 err = -ENXIO; 863 pn = ppp_pernet(net); 864 mutex_lock(&pn->all_ppp_mutex); 865 ppp = ppp_find_unit(pn, unit); 866 if (ppp) { 867 refcount_inc(&ppp->file.refcnt); 868 file->private_data = &ppp->file; 869 err = 0; 870 } 871 mutex_unlock(&pn->all_ppp_mutex); 872 break; 873 874 case PPPIOCATTCHAN: 875 if (get_user(unit, p)) 876 break; 877 err = -ENXIO; 878 pn = ppp_pernet(net); 879 spin_lock_bh(&pn->all_channels_lock); 880 chan = ppp_find_channel(pn, unit); 881 if (chan) { 882 refcount_inc(&chan->file.refcnt); 883 file->private_data = &chan->file; 884 err = 0; 885 } 886 spin_unlock_bh(&pn->all_channels_lock); 887 break; 888 889 default: 890 err = -ENOTTY; 891 } 892 893 return err; 894 } 895 896 static const struct file_operations ppp_device_fops = { 897 .owner = THIS_MODULE, 898 .read = ppp_read, 899 .write = ppp_write, 900 .poll = ppp_poll, 901 .unlocked_ioctl = ppp_ioctl, 902 .open = ppp_open, 903 .release = ppp_release, 904 .llseek = noop_llseek, 905 }; 906 907 static __net_init int ppp_init_net(struct net *net) 908 { 909 struct ppp_net *pn = net_generic(net, ppp_net_id); 910 911 idr_init(&pn->units_idr); 912 mutex_init(&pn->all_ppp_mutex); 913 914 INIT_LIST_HEAD(&pn->all_channels); 915 INIT_LIST_HEAD(&pn->new_channels); 916 917 spin_lock_init(&pn->all_channels_lock); 918 919 return 0; 920 } 921 922 static __net_exit void ppp_exit_net(struct net *net) 923 { 924 struct ppp_net *pn = net_generic(net, ppp_net_id); 925 struct net_device *dev; 926 struct net_device *aux; 927 struct ppp *ppp; 928 LIST_HEAD(list); 929 int id; 930 931 rtnl_lock(); 932 for_each_netdev_safe(net, dev, aux) { 933 if (dev->netdev_ops == &ppp_netdev_ops) 934 unregister_netdevice_queue(dev, &list); 935 } 936 937 idr_for_each_entry(&pn->units_idr, ppp, id) 938 /* Skip devices already unregistered by previous loop */ 939 if (!net_eq(dev_net(ppp->dev), net)) 940 unregister_netdevice_queue(ppp->dev, &list); 941 942 unregister_netdevice_many(&list); 943 rtnl_unlock(); 944 945 mutex_destroy(&pn->all_ppp_mutex); 946 idr_destroy(&pn->units_idr); 947 WARN_ON_ONCE(!list_empty(&pn->all_channels)); 948 WARN_ON_ONCE(!list_empty(&pn->new_channels)); 949 } 950 951 static struct pernet_operations ppp_net_ops = { 952 .init = ppp_init_net, 953 .exit = ppp_exit_net, 954 .id = &ppp_net_id, 955 .size = sizeof(struct ppp_net), 956 }; 957 958 static int ppp_unit_register(struct ppp *ppp, int unit, bool ifname_is_set) 959 { 960 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 961 int ret; 962 963 mutex_lock(&pn->all_ppp_mutex); 964 965 if (unit < 0) { 966 ret = unit_get(&pn->units_idr, ppp); 967 if (ret < 0) 968 goto err; 969 } else { 970 /* Caller asked for a specific unit number. Fail with -EEXIST 971 * if unavailable. For backward compatibility, return -EEXIST 972 * too if idr allocation fails; this makes pppd retry without 973 * requesting a specific unit number. 974 */ 975 if (unit_find(&pn->units_idr, unit)) { 976 ret = -EEXIST; 977 goto err; 978 } 979 ret = unit_set(&pn->units_idr, ppp, unit); 980 if (ret < 0) { 981 /* Rewrite error for backward compatibility */ 982 ret = -EEXIST; 983 goto err; 984 } 985 } 986 ppp->file.index = ret; 987 988 if (!ifname_is_set) 989 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ppp->file.index); 990 991 mutex_unlock(&pn->all_ppp_mutex); 992 993 ret = register_netdevice(ppp->dev); 994 if (ret < 0) 995 goto err_unit; 996 997 atomic_inc(&ppp_unit_count); 998 999 return 0; 1000 1001 err_unit: 1002 mutex_lock(&pn->all_ppp_mutex); 1003 unit_put(&pn->units_idr, ppp->file.index); 1004 err: 1005 mutex_unlock(&pn->all_ppp_mutex); 1006 1007 return ret; 1008 } 1009 1010 static int ppp_dev_configure(struct net *src_net, struct net_device *dev, 1011 const struct ppp_config *conf) 1012 { 1013 struct ppp *ppp = netdev_priv(dev); 1014 int indx; 1015 int err; 1016 int cpu; 1017 1018 ppp->dev = dev; 1019 ppp->ppp_net = src_net; 1020 ppp->mru = PPP_MRU; 1021 ppp->owner = conf->file; 1022 1023 init_ppp_file(&ppp->file, INTERFACE); 1024 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */ 1025 1026 for (indx = 0; indx < NUM_NP; ++indx) 1027 ppp->npmode[indx] = NPMODE_PASS; 1028 INIT_LIST_HEAD(&ppp->channels); 1029 spin_lock_init(&ppp->rlock); 1030 spin_lock_init(&ppp->wlock); 1031 1032 ppp->xmit_recursion = alloc_percpu(int); 1033 if (!ppp->xmit_recursion) { 1034 err = -ENOMEM; 1035 goto err1; 1036 } 1037 for_each_possible_cpu(cpu) 1038 (*per_cpu_ptr(ppp->xmit_recursion, cpu)) = 0; 1039 1040 #ifdef CONFIG_PPP_MULTILINK 1041 ppp->minseq = -1; 1042 skb_queue_head_init(&ppp->mrq); 1043 #endif /* CONFIG_PPP_MULTILINK */ 1044 #ifdef CONFIG_PPP_FILTER 1045 ppp->pass_filter = NULL; 1046 ppp->active_filter = NULL; 1047 #endif /* CONFIG_PPP_FILTER */ 1048 1049 err = ppp_unit_register(ppp, conf->unit, conf->ifname_is_set); 1050 if (err < 0) 1051 goto err2; 1052 1053 conf->file->private_data = &ppp->file; 1054 1055 return 0; 1056 err2: 1057 free_percpu(ppp->xmit_recursion); 1058 err1: 1059 return err; 1060 } 1061 1062 static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = { 1063 [IFLA_PPP_DEV_FD] = { .type = NLA_S32 }, 1064 }; 1065 1066 static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[], 1067 struct netlink_ext_ack *extack) 1068 { 1069 if (!data) 1070 return -EINVAL; 1071 1072 if (!data[IFLA_PPP_DEV_FD]) 1073 return -EINVAL; 1074 if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0) 1075 return -EBADF; 1076 1077 return 0; 1078 } 1079 1080 static int ppp_nl_newlink(struct net *src_net, struct net_device *dev, 1081 struct nlattr *tb[], struct nlattr *data[], 1082 struct netlink_ext_ack *extack) 1083 { 1084 struct ppp_config conf = { 1085 .unit = -1, 1086 .ifname_is_set = true, 1087 }; 1088 struct file *file; 1089 int err; 1090 1091 file = fget(nla_get_s32(data[IFLA_PPP_DEV_FD])); 1092 if (!file) 1093 return -EBADF; 1094 1095 /* rtnl_lock is already held here, but ppp_create_interface() locks 1096 * ppp_mutex before holding rtnl_lock. Using mutex_trylock() avoids 1097 * possible deadlock due to lock order inversion, at the cost of 1098 * pushing the problem back to userspace. 1099 */ 1100 if (!mutex_trylock(&ppp_mutex)) { 1101 err = -EBUSY; 1102 goto out; 1103 } 1104 1105 if (file->f_op != &ppp_device_fops || file->private_data) { 1106 err = -EBADF; 1107 goto out_unlock; 1108 } 1109 1110 conf.file = file; 1111 1112 /* Don't use device name generated by the rtnetlink layer when ifname 1113 * isn't specified. Let ppp_dev_configure() set the device name using 1114 * the PPP unit identifer as suffix (i.e. ppp<unit_id>). This allows 1115 * userspace to infer the device name using to the PPPIOCGUNIT ioctl. 1116 */ 1117 if (!tb[IFLA_IFNAME]) 1118 conf.ifname_is_set = false; 1119 1120 err = ppp_dev_configure(src_net, dev, &conf); 1121 1122 out_unlock: 1123 mutex_unlock(&ppp_mutex); 1124 out: 1125 fput(file); 1126 1127 return err; 1128 } 1129 1130 static void ppp_nl_dellink(struct net_device *dev, struct list_head *head) 1131 { 1132 unregister_netdevice_queue(dev, head); 1133 } 1134 1135 static size_t ppp_nl_get_size(const struct net_device *dev) 1136 { 1137 return 0; 1138 } 1139 1140 static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev) 1141 { 1142 return 0; 1143 } 1144 1145 static struct net *ppp_nl_get_link_net(const struct net_device *dev) 1146 { 1147 struct ppp *ppp = netdev_priv(dev); 1148 1149 return ppp->ppp_net; 1150 } 1151 1152 static struct rtnl_link_ops ppp_link_ops __read_mostly = { 1153 .kind = "ppp", 1154 .maxtype = IFLA_PPP_MAX, 1155 .policy = ppp_nl_policy, 1156 .priv_size = sizeof(struct ppp), 1157 .setup = ppp_setup, 1158 .validate = ppp_nl_validate, 1159 .newlink = ppp_nl_newlink, 1160 .dellink = ppp_nl_dellink, 1161 .get_size = ppp_nl_get_size, 1162 .fill_info = ppp_nl_fill_info, 1163 .get_link_net = ppp_nl_get_link_net, 1164 }; 1165 1166 #define PPP_MAJOR 108 1167 1168 /* Called at boot time if ppp is compiled into the kernel, 1169 or at module load time (from init_module) if compiled as a module. */ 1170 static int __init ppp_init(void) 1171 { 1172 int err; 1173 1174 pr_info("PPP generic driver version " PPP_VERSION "\n"); 1175 1176 err = register_pernet_device(&ppp_net_ops); 1177 if (err) { 1178 pr_err("failed to register PPP pernet device (%d)\n", err); 1179 goto out; 1180 } 1181 1182 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops); 1183 if (err) { 1184 pr_err("failed to register PPP device (%d)\n", err); 1185 goto out_net; 1186 } 1187 1188 ppp_class = class_create(THIS_MODULE, "ppp"); 1189 if (IS_ERR(ppp_class)) { 1190 err = PTR_ERR(ppp_class); 1191 goto out_chrdev; 1192 } 1193 1194 err = rtnl_link_register(&ppp_link_ops); 1195 if (err) { 1196 pr_err("failed to register rtnetlink PPP handler\n"); 1197 goto out_class; 1198 } 1199 1200 /* not a big deal if we fail here :-) */ 1201 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp"); 1202 1203 return 0; 1204 1205 out_class: 1206 class_destroy(ppp_class); 1207 out_chrdev: 1208 unregister_chrdev(PPP_MAJOR, "ppp"); 1209 out_net: 1210 unregister_pernet_device(&ppp_net_ops); 1211 out: 1212 return err; 1213 } 1214 1215 /* 1216 * Network interface unit routines. 1217 */ 1218 static netdev_tx_t 1219 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev) 1220 { 1221 struct ppp *ppp = netdev_priv(dev); 1222 int npi, proto; 1223 unsigned char *pp; 1224 1225 npi = ethertype_to_npindex(ntohs(skb->protocol)); 1226 if (npi < 0) 1227 goto outf; 1228 1229 /* Drop, accept or reject the packet */ 1230 switch (ppp->npmode[npi]) { 1231 case NPMODE_PASS: 1232 break; 1233 case NPMODE_QUEUE: 1234 /* it would be nice to have a way to tell the network 1235 system to queue this one up for later. */ 1236 goto outf; 1237 case NPMODE_DROP: 1238 case NPMODE_ERROR: 1239 goto outf; 1240 } 1241 1242 /* Put the 2-byte PPP protocol number on the front, 1243 making sure there is room for the address and control fields. */ 1244 if (skb_cow_head(skb, PPP_HDRLEN)) 1245 goto outf; 1246 1247 pp = skb_push(skb, 2); 1248 proto = npindex_to_proto[npi]; 1249 put_unaligned_be16(proto, pp); 1250 1251 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev))); 1252 ppp_xmit_process(ppp, skb); 1253 1254 return NETDEV_TX_OK; 1255 1256 outf: 1257 kfree_skb(skb); 1258 ++dev->stats.tx_dropped; 1259 return NETDEV_TX_OK; 1260 } 1261 1262 static int 1263 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 1264 { 1265 struct ppp *ppp = netdev_priv(dev); 1266 int err = -EFAULT; 1267 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data; 1268 struct ppp_stats stats; 1269 struct ppp_comp_stats cstats; 1270 char *vers; 1271 1272 switch (cmd) { 1273 case SIOCGPPPSTATS: 1274 ppp_get_stats(ppp, &stats); 1275 if (copy_to_user(addr, &stats, sizeof(stats))) 1276 break; 1277 err = 0; 1278 break; 1279 1280 case SIOCGPPPCSTATS: 1281 memset(&cstats, 0, sizeof(cstats)); 1282 if (ppp->xc_state) 1283 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c); 1284 if (ppp->rc_state) 1285 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d); 1286 if (copy_to_user(addr, &cstats, sizeof(cstats))) 1287 break; 1288 err = 0; 1289 break; 1290 1291 case SIOCGPPPVER: 1292 vers = PPP_VERSION; 1293 if (copy_to_user(addr, vers, strlen(vers) + 1)) 1294 break; 1295 err = 0; 1296 break; 1297 1298 default: 1299 err = -EINVAL; 1300 } 1301 1302 return err; 1303 } 1304 1305 static void 1306 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64) 1307 { 1308 struct ppp *ppp = netdev_priv(dev); 1309 1310 ppp_recv_lock(ppp); 1311 stats64->rx_packets = ppp->stats64.rx_packets; 1312 stats64->rx_bytes = ppp->stats64.rx_bytes; 1313 ppp_recv_unlock(ppp); 1314 1315 ppp_xmit_lock(ppp); 1316 stats64->tx_packets = ppp->stats64.tx_packets; 1317 stats64->tx_bytes = ppp->stats64.tx_bytes; 1318 ppp_xmit_unlock(ppp); 1319 1320 stats64->rx_errors = dev->stats.rx_errors; 1321 stats64->tx_errors = dev->stats.tx_errors; 1322 stats64->rx_dropped = dev->stats.rx_dropped; 1323 stats64->tx_dropped = dev->stats.tx_dropped; 1324 stats64->rx_length_errors = dev->stats.rx_length_errors; 1325 } 1326 1327 static int ppp_dev_init(struct net_device *dev) 1328 { 1329 struct ppp *ppp; 1330 1331 netdev_lockdep_set_classes(dev); 1332 1333 ppp = netdev_priv(dev); 1334 /* Let the netdevice take a reference on the ppp file. This ensures 1335 * that ppp_destroy_interface() won't run before the device gets 1336 * unregistered. 1337 */ 1338 refcount_inc(&ppp->file.refcnt); 1339 1340 return 0; 1341 } 1342 1343 static void ppp_dev_uninit(struct net_device *dev) 1344 { 1345 struct ppp *ppp = netdev_priv(dev); 1346 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 1347 1348 ppp_lock(ppp); 1349 ppp->closing = 1; 1350 ppp_unlock(ppp); 1351 1352 mutex_lock(&pn->all_ppp_mutex); 1353 unit_put(&pn->units_idr, ppp->file.index); 1354 mutex_unlock(&pn->all_ppp_mutex); 1355 1356 ppp->owner = NULL; 1357 1358 ppp->file.dead = 1; 1359 wake_up_interruptible(&ppp->file.rwait); 1360 } 1361 1362 static void ppp_dev_priv_destructor(struct net_device *dev) 1363 { 1364 struct ppp *ppp; 1365 1366 ppp = netdev_priv(dev); 1367 if (refcount_dec_and_test(&ppp->file.refcnt)) 1368 ppp_destroy_interface(ppp); 1369 } 1370 1371 static const struct net_device_ops ppp_netdev_ops = { 1372 .ndo_init = ppp_dev_init, 1373 .ndo_uninit = ppp_dev_uninit, 1374 .ndo_start_xmit = ppp_start_xmit, 1375 .ndo_do_ioctl = ppp_net_ioctl, 1376 .ndo_get_stats64 = ppp_get_stats64, 1377 }; 1378 1379 static struct device_type ppp_type = { 1380 .name = "ppp", 1381 }; 1382 1383 static void ppp_setup(struct net_device *dev) 1384 { 1385 dev->netdev_ops = &ppp_netdev_ops; 1386 SET_NETDEV_DEVTYPE(dev, &ppp_type); 1387 1388 dev->features |= NETIF_F_LLTX; 1389 1390 dev->hard_header_len = PPP_HDRLEN; 1391 dev->mtu = PPP_MRU; 1392 dev->addr_len = 0; 1393 dev->tx_queue_len = 3; 1394 dev->type = ARPHRD_PPP; 1395 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 1396 dev->priv_destructor = ppp_dev_priv_destructor; 1397 netif_keep_dst(dev); 1398 } 1399 1400 /* 1401 * Transmit-side routines. 1402 */ 1403 1404 /* Called to do any work queued up on the transmit side that can now be done */ 1405 static void __ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb) 1406 { 1407 ppp_xmit_lock(ppp); 1408 if (!ppp->closing) { 1409 ppp_push(ppp); 1410 1411 if (skb) 1412 skb_queue_tail(&ppp->file.xq, skb); 1413 while (!ppp->xmit_pending && 1414 (skb = skb_dequeue(&ppp->file.xq))) 1415 ppp_send_frame(ppp, skb); 1416 /* If there's no work left to do, tell the core net 1417 code that we can accept some more. */ 1418 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq)) 1419 netif_wake_queue(ppp->dev); 1420 else 1421 netif_stop_queue(ppp->dev); 1422 } 1423 ppp_xmit_unlock(ppp); 1424 } 1425 1426 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb) 1427 { 1428 local_bh_disable(); 1429 1430 if (unlikely(*this_cpu_ptr(ppp->xmit_recursion))) 1431 goto err; 1432 1433 (*this_cpu_ptr(ppp->xmit_recursion))++; 1434 __ppp_xmit_process(ppp, skb); 1435 (*this_cpu_ptr(ppp->xmit_recursion))--; 1436 1437 local_bh_enable(); 1438 1439 return; 1440 1441 err: 1442 local_bh_enable(); 1443 1444 kfree_skb(skb); 1445 1446 if (net_ratelimit()) 1447 netdev_err(ppp->dev, "recursion detected\n"); 1448 } 1449 1450 static inline struct sk_buff * 1451 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) 1452 { 1453 struct sk_buff *new_skb; 1454 int len; 1455 int new_skb_size = ppp->dev->mtu + 1456 ppp->xcomp->comp_extra + ppp->dev->hard_header_len; 1457 int compressor_skb_size = ppp->dev->mtu + 1458 ppp->xcomp->comp_extra + PPP_HDRLEN; 1459 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC); 1460 if (!new_skb) { 1461 if (net_ratelimit()) 1462 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n"); 1463 return NULL; 1464 } 1465 if (ppp->dev->hard_header_len > PPP_HDRLEN) 1466 skb_reserve(new_skb, 1467 ppp->dev->hard_header_len - PPP_HDRLEN); 1468 1469 /* compressor still expects A/C bytes in hdr */ 1470 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, 1471 new_skb->data, skb->len + 2, 1472 compressor_skb_size); 1473 if (len > 0 && (ppp->flags & SC_CCP_UP)) { 1474 consume_skb(skb); 1475 skb = new_skb; 1476 skb_put(skb, len); 1477 skb_pull(skb, 2); /* pull off A/C bytes */ 1478 } else if (len == 0) { 1479 /* didn't compress, or CCP not up yet */ 1480 consume_skb(new_skb); 1481 new_skb = skb; 1482 } else { 1483 /* 1484 * (len < 0) 1485 * MPPE requires that we do not send unencrypted 1486 * frames. The compressor will return -1 if we 1487 * should drop the frame. We cannot simply test 1488 * the compress_proto because MPPE and MPPC share 1489 * the same number. 1490 */ 1491 if (net_ratelimit()) 1492 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n"); 1493 kfree_skb(skb); 1494 consume_skb(new_skb); 1495 new_skb = NULL; 1496 } 1497 return new_skb; 1498 } 1499 1500 /* 1501 * Compress and send a frame. 1502 * The caller should have locked the xmit path, 1503 * and xmit_pending should be 0. 1504 */ 1505 static void 1506 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) 1507 { 1508 int proto = PPP_PROTO(skb); 1509 struct sk_buff *new_skb; 1510 int len; 1511 unsigned char *cp; 1512 1513 if (proto < 0x8000) { 1514 #ifdef CONFIG_PPP_FILTER 1515 /* check if we should pass this packet */ 1516 /* the filter instructions are constructed assuming 1517 a four-byte PPP header on each packet */ 1518 *(u8 *)skb_push(skb, 2) = 1; 1519 if (ppp->pass_filter && 1520 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 1521 if (ppp->debug & 1) 1522 netdev_printk(KERN_DEBUG, ppp->dev, 1523 "PPP: outbound frame " 1524 "not passed\n"); 1525 kfree_skb(skb); 1526 return; 1527 } 1528 /* if this packet passes the active filter, record the time */ 1529 if (!(ppp->active_filter && 1530 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 1531 ppp->last_xmit = jiffies; 1532 skb_pull(skb, 2); 1533 #else 1534 /* for data packets, record the time */ 1535 ppp->last_xmit = jiffies; 1536 #endif /* CONFIG_PPP_FILTER */ 1537 } 1538 1539 ++ppp->stats64.tx_packets; 1540 ppp->stats64.tx_bytes += skb->len - 2; 1541 1542 switch (proto) { 1543 case PPP_IP: 1544 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0) 1545 break; 1546 /* try to do VJ TCP header compression */ 1547 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2, 1548 GFP_ATOMIC); 1549 if (!new_skb) { 1550 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n"); 1551 goto drop; 1552 } 1553 skb_reserve(new_skb, ppp->dev->hard_header_len - 2); 1554 cp = skb->data + 2; 1555 len = slhc_compress(ppp->vj, cp, skb->len - 2, 1556 new_skb->data + 2, &cp, 1557 !(ppp->flags & SC_NO_TCP_CCID)); 1558 if (cp == skb->data + 2) { 1559 /* didn't compress */ 1560 consume_skb(new_skb); 1561 } else { 1562 if (cp[0] & SL_TYPE_COMPRESSED_TCP) { 1563 proto = PPP_VJC_COMP; 1564 cp[0] &= ~SL_TYPE_COMPRESSED_TCP; 1565 } else { 1566 proto = PPP_VJC_UNCOMP; 1567 cp[0] = skb->data[2]; 1568 } 1569 consume_skb(skb); 1570 skb = new_skb; 1571 cp = skb_put(skb, len + 2); 1572 cp[0] = 0; 1573 cp[1] = proto; 1574 } 1575 break; 1576 1577 case PPP_CCP: 1578 /* peek at outbound CCP frames */ 1579 ppp_ccp_peek(ppp, skb, 0); 1580 break; 1581 } 1582 1583 /* try to do packet compression */ 1584 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state && 1585 proto != PPP_LCP && proto != PPP_CCP) { 1586 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) { 1587 if (net_ratelimit()) 1588 netdev_err(ppp->dev, 1589 "ppp: compression required but " 1590 "down - pkt dropped.\n"); 1591 goto drop; 1592 } 1593 skb = pad_compress_skb(ppp, skb); 1594 if (!skb) 1595 goto drop; 1596 } 1597 1598 /* 1599 * If we are waiting for traffic (demand dialling), 1600 * queue it up for pppd to receive. 1601 */ 1602 if (ppp->flags & SC_LOOP_TRAFFIC) { 1603 if (ppp->file.rq.qlen > PPP_MAX_RQLEN) 1604 goto drop; 1605 skb_queue_tail(&ppp->file.rq, skb); 1606 wake_up_interruptible(&ppp->file.rwait); 1607 return; 1608 } 1609 1610 ppp->xmit_pending = skb; 1611 ppp_push(ppp); 1612 return; 1613 1614 drop: 1615 kfree_skb(skb); 1616 ++ppp->dev->stats.tx_errors; 1617 } 1618 1619 /* 1620 * Try to send the frame in xmit_pending. 1621 * The caller should have the xmit path locked. 1622 */ 1623 static void 1624 ppp_push(struct ppp *ppp) 1625 { 1626 struct list_head *list; 1627 struct channel *pch; 1628 struct sk_buff *skb = ppp->xmit_pending; 1629 1630 if (!skb) 1631 return; 1632 1633 list = &ppp->channels; 1634 if (list_empty(list)) { 1635 /* nowhere to send the packet, just drop it */ 1636 ppp->xmit_pending = NULL; 1637 kfree_skb(skb); 1638 return; 1639 } 1640 1641 if ((ppp->flags & SC_MULTILINK) == 0) { 1642 /* not doing multilink: send it down the first channel */ 1643 list = list->next; 1644 pch = list_entry(list, struct channel, clist); 1645 1646 spin_lock(&pch->downl); 1647 if (pch->chan) { 1648 if (pch->chan->ops->start_xmit(pch->chan, skb)) 1649 ppp->xmit_pending = NULL; 1650 } else { 1651 /* channel got unregistered */ 1652 kfree_skb(skb); 1653 ppp->xmit_pending = NULL; 1654 } 1655 spin_unlock(&pch->downl); 1656 return; 1657 } 1658 1659 #ifdef CONFIG_PPP_MULTILINK 1660 /* Multilink: fragment the packet over as many links 1661 as can take the packet at the moment. */ 1662 if (!ppp_mp_explode(ppp, skb)) 1663 return; 1664 #endif /* CONFIG_PPP_MULTILINK */ 1665 1666 ppp->xmit_pending = NULL; 1667 kfree_skb(skb); 1668 } 1669 1670 #ifdef CONFIG_PPP_MULTILINK 1671 static bool mp_protocol_compress __read_mostly = true; 1672 module_param(mp_protocol_compress, bool, 0644); 1673 MODULE_PARM_DESC(mp_protocol_compress, 1674 "compress protocol id in multilink fragments"); 1675 1676 /* 1677 * Divide a packet to be transmitted into fragments and 1678 * send them out the individual links. 1679 */ 1680 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb) 1681 { 1682 int len, totlen; 1683 int i, bits, hdrlen, mtu; 1684 int flen; 1685 int navail, nfree, nzero; 1686 int nbigger; 1687 int totspeed; 1688 int totfree; 1689 unsigned char *p, *q; 1690 struct list_head *list; 1691 struct channel *pch; 1692 struct sk_buff *frag; 1693 struct ppp_channel *chan; 1694 1695 totspeed = 0; /*total bitrate of the bundle*/ 1696 nfree = 0; /* # channels which have no packet already queued */ 1697 navail = 0; /* total # of usable channels (not deregistered) */ 1698 nzero = 0; /* number of channels with zero speed associated*/ 1699 totfree = 0; /*total # of channels available and 1700 *having no queued packets before 1701 *starting the fragmentation*/ 1702 1703 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1704 i = 0; 1705 list_for_each_entry(pch, &ppp->channels, clist) { 1706 if (pch->chan) { 1707 pch->avail = 1; 1708 navail++; 1709 pch->speed = pch->chan->speed; 1710 } else { 1711 pch->avail = 0; 1712 } 1713 if (pch->avail) { 1714 if (skb_queue_empty(&pch->file.xq) || 1715 !pch->had_frag) { 1716 if (pch->speed == 0) 1717 nzero++; 1718 else 1719 totspeed += pch->speed; 1720 1721 pch->avail = 2; 1722 ++nfree; 1723 ++totfree; 1724 } 1725 if (!pch->had_frag && i < ppp->nxchan) 1726 ppp->nxchan = i; 1727 } 1728 ++i; 1729 } 1730 /* 1731 * Don't start sending this packet unless at least half of 1732 * the channels are free. This gives much better TCP 1733 * performance if we have a lot of channels. 1734 */ 1735 if (nfree == 0 || nfree < navail / 2) 1736 return 0; /* can't take now, leave it in xmit_pending */ 1737 1738 /* Do protocol field compression */ 1739 p = skb->data; 1740 len = skb->len; 1741 if (*p == 0 && mp_protocol_compress) { 1742 ++p; 1743 --len; 1744 } 1745 1746 totlen = len; 1747 nbigger = len % nfree; 1748 1749 /* skip to the channel after the one we last used 1750 and start at that one */ 1751 list = &ppp->channels; 1752 for (i = 0; i < ppp->nxchan; ++i) { 1753 list = list->next; 1754 if (list == &ppp->channels) { 1755 i = 0; 1756 break; 1757 } 1758 } 1759 1760 /* create a fragment for each channel */ 1761 bits = B; 1762 while (len > 0) { 1763 list = list->next; 1764 if (list == &ppp->channels) { 1765 i = 0; 1766 continue; 1767 } 1768 pch = list_entry(list, struct channel, clist); 1769 ++i; 1770 if (!pch->avail) 1771 continue; 1772 1773 /* 1774 * Skip this channel if it has a fragment pending already and 1775 * we haven't given a fragment to all of the free channels. 1776 */ 1777 if (pch->avail == 1) { 1778 if (nfree > 0) 1779 continue; 1780 } else { 1781 pch->avail = 1; 1782 } 1783 1784 /* check the channel's mtu and whether it is still attached. */ 1785 spin_lock(&pch->downl); 1786 if (pch->chan == NULL) { 1787 /* can't use this channel, it's being deregistered */ 1788 if (pch->speed == 0) 1789 nzero--; 1790 else 1791 totspeed -= pch->speed; 1792 1793 spin_unlock(&pch->downl); 1794 pch->avail = 0; 1795 totlen = len; 1796 totfree--; 1797 nfree--; 1798 if (--navail == 0) 1799 break; 1800 continue; 1801 } 1802 1803 /* 1804 *if the channel speed is not set divide 1805 *the packet evenly among the free channels; 1806 *otherwise divide it according to the speed 1807 *of the channel we are going to transmit on 1808 */ 1809 flen = len; 1810 if (nfree > 0) { 1811 if (pch->speed == 0) { 1812 flen = len/nfree; 1813 if (nbigger > 0) { 1814 flen++; 1815 nbigger--; 1816 } 1817 } else { 1818 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) / 1819 ((totspeed*totfree)/pch->speed)) - hdrlen; 1820 if (nbigger > 0) { 1821 flen += ((totfree - nzero)*pch->speed)/totspeed; 1822 nbigger -= ((totfree - nzero)*pch->speed)/ 1823 totspeed; 1824 } 1825 } 1826 nfree--; 1827 } 1828 1829 /* 1830 *check if we are on the last channel or 1831 *we exceded the length of the data to 1832 *fragment 1833 */ 1834 if ((nfree <= 0) || (flen > len)) 1835 flen = len; 1836 /* 1837 *it is not worth to tx on slow channels: 1838 *in that case from the resulting flen according to the 1839 *above formula will be equal or less than zero. 1840 *Skip the channel in this case 1841 */ 1842 if (flen <= 0) { 1843 pch->avail = 2; 1844 spin_unlock(&pch->downl); 1845 continue; 1846 } 1847 1848 /* 1849 * hdrlen includes the 2-byte PPP protocol field, but the 1850 * MTU counts only the payload excluding the protocol field. 1851 * (RFC1661 Section 2) 1852 */ 1853 mtu = pch->chan->mtu - (hdrlen - 2); 1854 if (mtu < 4) 1855 mtu = 4; 1856 if (flen > mtu) 1857 flen = mtu; 1858 if (flen == len) 1859 bits |= E; 1860 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC); 1861 if (!frag) 1862 goto noskb; 1863 q = skb_put(frag, flen + hdrlen); 1864 1865 /* make the MP header */ 1866 put_unaligned_be16(PPP_MP, q); 1867 if (ppp->flags & SC_MP_XSHORTSEQ) { 1868 q[2] = bits + ((ppp->nxseq >> 8) & 0xf); 1869 q[3] = ppp->nxseq; 1870 } else { 1871 q[2] = bits; 1872 q[3] = ppp->nxseq >> 16; 1873 q[4] = ppp->nxseq >> 8; 1874 q[5] = ppp->nxseq; 1875 } 1876 1877 memcpy(q + hdrlen, p, flen); 1878 1879 /* try to send it down the channel */ 1880 chan = pch->chan; 1881 if (!skb_queue_empty(&pch->file.xq) || 1882 !chan->ops->start_xmit(chan, frag)) 1883 skb_queue_tail(&pch->file.xq, frag); 1884 pch->had_frag = 1; 1885 p += flen; 1886 len -= flen; 1887 ++ppp->nxseq; 1888 bits = 0; 1889 spin_unlock(&pch->downl); 1890 } 1891 ppp->nxchan = i; 1892 1893 return 1; 1894 1895 noskb: 1896 spin_unlock(&pch->downl); 1897 if (ppp->debug & 1) 1898 netdev_err(ppp->dev, "PPP: no memory (fragment)\n"); 1899 ++ppp->dev->stats.tx_errors; 1900 ++ppp->nxseq; 1901 return 1; /* abandon the frame */ 1902 } 1903 #endif /* CONFIG_PPP_MULTILINK */ 1904 1905 /* Try to send data out on a channel */ 1906 static void __ppp_channel_push(struct channel *pch) 1907 { 1908 struct sk_buff *skb; 1909 struct ppp *ppp; 1910 1911 spin_lock(&pch->downl); 1912 if (pch->chan) { 1913 while (!skb_queue_empty(&pch->file.xq)) { 1914 skb = skb_dequeue(&pch->file.xq); 1915 if (!pch->chan->ops->start_xmit(pch->chan, skb)) { 1916 /* put the packet back and try again later */ 1917 skb_queue_head(&pch->file.xq, skb); 1918 break; 1919 } 1920 } 1921 } else { 1922 /* channel got deregistered */ 1923 skb_queue_purge(&pch->file.xq); 1924 } 1925 spin_unlock(&pch->downl); 1926 /* see if there is anything from the attached unit to be sent */ 1927 if (skb_queue_empty(&pch->file.xq)) { 1928 ppp = pch->ppp; 1929 if (ppp) 1930 __ppp_xmit_process(ppp, NULL); 1931 } 1932 } 1933 1934 static void ppp_channel_push(struct channel *pch) 1935 { 1936 read_lock_bh(&pch->upl); 1937 if (pch->ppp) { 1938 (*this_cpu_ptr(pch->ppp->xmit_recursion))++; 1939 __ppp_channel_push(pch); 1940 (*this_cpu_ptr(pch->ppp->xmit_recursion))--; 1941 } else { 1942 __ppp_channel_push(pch); 1943 } 1944 read_unlock_bh(&pch->upl); 1945 } 1946 1947 /* 1948 * Receive-side routines. 1949 */ 1950 1951 struct ppp_mp_skb_parm { 1952 u32 sequence; 1953 u8 BEbits; 1954 }; 1955 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb)) 1956 1957 static inline void 1958 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1959 { 1960 ppp_recv_lock(ppp); 1961 if (!ppp->closing) 1962 ppp_receive_frame(ppp, skb, pch); 1963 else 1964 kfree_skb(skb); 1965 ppp_recv_unlock(ppp); 1966 } 1967 1968 /** 1969 * __ppp_decompress_proto - Decompress protocol field, slim version. 1970 * @skb: Socket buffer where protocol field should be decompressed. It must have 1971 * at least 1 byte of head room and 1 byte of linear data. First byte of 1972 * data must be a protocol field byte. 1973 * 1974 * Decompress protocol field in PPP header if it's compressed, e.g. when 1975 * Protocol-Field-Compression (PFC) was negotiated. No checks w.r.t. skb data 1976 * length are done in this function. 1977 */ 1978 static void __ppp_decompress_proto(struct sk_buff *skb) 1979 { 1980 if (skb->data[0] & 0x01) 1981 *(u8 *)skb_push(skb, 1) = 0x00; 1982 } 1983 1984 /** 1985 * ppp_decompress_proto - Check skb data room and decompress protocol field. 1986 * @skb: Socket buffer where protocol field should be decompressed. First byte 1987 * of data must be a protocol field byte. 1988 * 1989 * Decompress protocol field in PPP header if it's compressed, e.g. when 1990 * Protocol-Field-Compression (PFC) was negotiated. This function also makes 1991 * sure that skb data room is sufficient for Protocol field, before and after 1992 * decompression. 1993 * 1994 * Return: true - decompressed successfully, false - not enough room in skb. 1995 */ 1996 static bool ppp_decompress_proto(struct sk_buff *skb) 1997 { 1998 /* At least one byte should be present (if protocol is compressed) */ 1999 if (!pskb_may_pull(skb, 1)) 2000 return false; 2001 2002 __ppp_decompress_proto(skb); 2003 2004 /* Protocol field should occupy 2 bytes when not compressed */ 2005 return pskb_may_pull(skb, 2); 2006 } 2007 2008 void 2009 ppp_input(struct ppp_channel *chan, struct sk_buff *skb) 2010 { 2011 struct channel *pch = chan->ppp; 2012 int proto; 2013 2014 if (!pch) { 2015 kfree_skb(skb); 2016 return; 2017 } 2018 2019 read_lock_bh(&pch->upl); 2020 if (!ppp_decompress_proto(skb)) { 2021 kfree_skb(skb); 2022 if (pch->ppp) { 2023 ++pch->ppp->dev->stats.rx_length_errors; 2024 ppp_receive_error(pch->ppp); 2025 } 2026 goto done; 2027 } 2028 2029 proto = PPP_PROTO(skb); 2030 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) { 2031 /* put it on the channel queue */ 2032 skb_queue_tail(&pch->file.rq, skb); 2033 /* drop old frames if queue too long */ 2034 while (pch->file.rq.qlen > PPP_MAX_RQLEN && 2035 (skb = skb_dequeue(&pch->file.rq))) 2036 kfree_skb(skb); 2037 wake_up_interruptible(&pch->file.rwait); 2038 } else { 2039 ppp_do_recv(pch->ppp, skb, pch); 2040 } 2041 2042 done: 2043 read_unlock_bh(&pch->upl); 2044 } 2045 2046 /* Put a 0-length skb in the receive queue as an error indication */ 2047 void 2048 ppp_input_error(struct ppp_channel *chan, int code) 2049 { 2050 struct channel *pch = chan->ppp; 2051 struct sk_buff *skb; 2052 2053 if (!pch) 2054 return; 2055 2056 read_lock_bh(&pch->upl); 2057 if (pch->ppp) { 2058 skb = alloc_skb(0, GFP_ATOMIC); 2059 if (skb) { 2060 skb->len = 0; /* probably unnecessary */ 2061 skb->cb[0] = code; 2062 ppp_do_recv(pch->ppp, skb, pch); 2063 } 2064 } 2065 read_unlock_bh(&pch->upl); 2066 } 2067 2068 /* 2069 * We come in here to process a received frame. 2070 * The receive side of the ppp unit is locked. 2071 */ 2072 static void 2073 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2074 { 2075 /* note: a 0-length skb is used as an error indication */ 2076 if (skb->len > 0) { 2077 skb_checksum_complete_unset(skb); 2078 #ifdef CONFIG_PPP_MULTILINK 2079 /* XXX do channel-level decompression here */ 2080 if (PPP_PROTO(skb) == PPP_MP) 2081 ppp_receive_mp_frame(ppp, skb, pch); 2082 else 2083 #endif /* CONFIG_PPP_MULTILINK */ 2084 ppp_receive_nonmp_frame(ppp, skb); 2085 } else { 2086 kfree_skb(skb); 2087 ppp_receive_error(ppp); 2088 } 2089 } 2090 2091 static void 2092 ppp_receive_error(struct ppp *ppp) 2093 { 2094 ++ppp->dev->stats.rx_errors; 2095 if (ppp->vj) 2096 slhc_toss(ppp->vj); 2097 } 2098 2099 static void 2100 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) 2101 { 2102 struct sk_buff *ns; 2103 int proto, len, npi; 2104 2105 /* 2106 * Decompress the frame, if compressed. 2107 * Note that some decompressors need to see uncompressed frames 2108 * that come in as well as compressed frames. 2109 */ 2110 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) && 2111 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0) 2112 skb = ppp_decompress_frame(ppp, skb); 2113 2114 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR) 2115 goto err; 2116 2117 /* At this point the "Protocol" field MUST be decompressed, either in 2118 * ppp_input(), ppp_decompress_frame() or in ppp_receive_mp_frame(). 2119 */ 2120 proto = PPP_PROTO(skb); 2121 switch (proto) { 2122 case PPP_VJC_COMP: 2123 /* decompress VJ compressed packets */ 2124 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 2125 goto err; 2126 2127 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) { 2128 /* copy to a new sk_buff with more tailroom */ 2129 ns = dev_alloc_skb(skb->len + 128); 2130 if (!ns) { 2131 netdev_err(ppp->dev, "PPP: no memory " 2132 "(VJ decomp)\n"); 2133 goto err; 2134 } 2135 skb_reserve(ns, 2); 2136 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len); 2137 consume_skb(skb); 2138 skb = ns; 2139 } 2140 else 2141 skb->ip_summed = CHECKSUM_NONE; 2142 2143 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2); 2144 if (len <= 0) { 2145 netdev_printk(KERN_DEBUG, ppp->dev, 2146 "PPP: VJ decompression error\n"); 2147 goto err; 2148 } 2149 len += 2; 2150 if (len > skb->len) 2151 skb_put(skb, len - skb->len); 2152 else if (len < skb->len) 2153 skb_trim(skb, len); 2154 proto = PPP_IP; 2155 break; 2156 2157 case PPP_VJC_UNCOMP: 2158 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 2159 goto err; 2160 2161 /* Until we fix the decompressor need to make sure 2162 * data portion is linear. 2163 */ 2164 if (!pskb_may_pull(skb, skb->len)) 2165 goto err; 2166 2167 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) { 2168 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n"); 2169 goto err; 2170 } 2171 proto = PPP_IP; 2172 break; 2173 2174 case PPP_CCP: 2175 ppp_ccp_peek(ppp, skb, 1); 2176 break; 2177 } 2178 2179 ++ppp->stats64.rx_packets; 2180 ppp->stats64.rx_bytes += skb->len - 2; 2181 2182 npi = proto_to_npindex(proto); 2183 if (npi < 0) { 2184 /* control or unknown frame - pass it to pppd */ 2185 skb_queue_tail(&ppp->file.rq, skb); 2186 /* limit queue length by dropping old frames */ 2187 while (ppp->file.rq.qlen > PPP_MAX_RQLEN && 2188 (skb = skb_dequeue(&ppp->file.rq))) 2189 kfree_skb(skb); 2190 /* wake up any process polling or blocking on read */ 2191 wake_up_interruptible(&ppp->file.rwait); 2192 2193 } else { 2194 /* network protocol frame - give it to the kernel */ 2195 2196 #ifdef CONFIG_PPP_FILTER 2197 /* check if the packet passes the pass and active filters */ 2198 /* the filter instructions are constructed assuming 2199 a four-byte PPP header on each packet */ 2200 if (ppp->pass_filter || ppp->active_filter) { 2201 if (skb_unclone(skb, GFP_ATOMIC)) 2202 goto err; 2203 2204 *(u8 *)skb_push(skb, 2) = 0; 2205 if (ppp->pass_filter && 2206 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 2207 if (ppp->debug & 1) 2208 netdev_printk(KERN_DEBUG, ppp->dev, 2209 "PPP: inbound frame " 2210 "not passed\n"); 2211 kfree_skb(skb); 2212 return; 2213 } 2214 if (!(ppp->active_filter && 2215 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 2216 ppp->last_recv = jiffies; 2217 __skb_pull(skb, 2); 2218 } else 2219 #endif /* CONFIG_PPP_FILTER */ 2220 ppp->last_recv = jiffies; 2221 2222 if ((ppp->dev->flags & IFF_UP) == 0 || 2223 ppp->npmode[npi] != NPMODE_PASS) { 2224 kfree_skb(skb); 2225 } else { 2226 /* chop off protocol */ 2227 skb_pull_rcsum(skb, 2); 2228 skb->dev = ppp->dev; 2229 skb->protocol = htons(npindex_to_ethertype[npi]); 2230 skb_reset_mac_header(skb); 2231 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, 2232 dev_net(ppp->dev))); 2233 netif_rx(skb); 2234 } 2235 } 2236 return; 2237 2238 err: 2239 kfree_skb(skb); 2240 ppp_receive_error(ppp); 2241 } 2242 2243 static struct sk_buff * 2244 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb) 2245 { 2246 int proto = PPP_PROTO(skb); 2247 struct sk_buff *ns; 2248 int len; 2249 2250 /* Until we fix all the decompressor's need to make sure 2251 * data portion is linear. 2252 */ 2253 if (!pskb_may_pull(skb, skb->len)) 2254 goto err; 2255 2256 if (proto == PPP_COMP) { 2257 int obuff_size; 2258 2259 switch(ppp->rcomp->compress_proto) { 2260 case CI_MPPE: 2261 obuff_size = ppp->mru + PPP_HDRLEN + 1; 2262 break; 2263 default: 2264 obuff_size = ppp->mru + PPP_HDRLEN; 2265 break; 2266 } 2267 2268 ns = dev_alloc_skb(obuff_size); 2269 if (!ns) { 2270 netdev_err(ppp->dev, "ppp_decompress_frame: " 2271 "no memory\n"); 2272 goto err; 2273 } 2274 /* the decompressor still expects the A/C bytes in the hdr */ 2275 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2, 2276 skb->len + 2, ns->data, obuff_size); 2277 if (len < 0) { 2278 /* Pass the compressed frame to pppd as an 2279 error indication. */ 2280 if (len == DECOMP_FATALERROR) 2281 ppp->rstate |= SC_DC_FERROR; 2282 kfree_skb(ns); 2283 goto err; 2284 } 2285 2286 consume_skb(skb); 2287 skb = ns; 2288 skb_put(skb, len); 2289 skb_pull(skb, 2); /* pull off the A/C bytes */ 2290 2291 /* Don't call __ppp_decompress_proto() here, but instead rely on 2292 * corresponding algo (mppe/bsd/deflate) to decompress it. 2293 */ 2294 } else { 2295 /* Uncompressed frame - pass to decompressor so it 2296 can update its dictionary if necessary. */ 2297 if (ppp->rcomp->incomp) 2298 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2, 2299 skb->len + 2); 2300 } 2301 2302 return skb; 2303 2304 err: 2305 ppp->rstate |= SC_DC_ERROR; 2306 ppp_receive_error(ppp); 2307 return skb; 2308 } 2309 2310 #ifdef CONFIG_PPP_MULTILINK 2311 /* 2312 * Receive a multilink frame. 2313 * We put it on the reconstruction queue and then pull off 2314 * as many completed frames as we can. 2315 */ 2316 static void 2317 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2318 { 2319 u32 mask, seq; 2320 struct channel *ch; 2321 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 2322 2323 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0) 2324 goto err; /* no good, throw it away */ 2325 2326 /* Decode sequence number and begin/end bits */ 2327 if (ppp->flags & SC_MP_SHORTSEQ) { 2328 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3]; 2329 mask = 0xfff; 2330 } else { 2331 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5]; 2332 mask = 0xffffff; 2333 } 2334 PPP_MP_CB(skb)->BEbits = skb->data[2]; 2335 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */ 2336 2337 /* 2338 * Do protocol ID decompression on the first fragment of each packet. 2339 * We have to do that here, because ppp_receive_nonmp_frame() expects 2340 * decompressed protocol field. 2341 */ 2342 if (PPP_MP_CB(skb)->BEbits & B) 2343 __ppp_decompress_proto(skb); 2344 2345 /* 2346 * Expand sequence number to 32 bits, making it as close 2347 * as possible to ppp->minseq. 2348 */ 2349 seq |= ppp->minseq & ~mask; 2350 if ((int)(ppp->minseq - seq) > (int)(mask >> 1)) 2351 seq += mask + 1; 2352 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1)) 2353 seq -= mask + 1; /* should never happen */ 2354 PPP_MP_CB(skb)->sequence = seq; 2355 pch->lastseq = seq; 2356 2357 /* 2358 * If this packet comes before the next one we were expecting, 2359 * drop it. 2360 */ 2361 if (seq_before(seq, ppp->nextseq)) { 2362 kfree_skb(skb); 2363 ++ppp->dev->stats.rx_dropped; 2364 ppp_receive_error(ppp); 2365 return; 2366 } 2367 2368 /* 2369 * Reevaluate minseq, the minimum over all channels of the 2370 * last sequence number received on each channel. Because of 2371 * the increasing sequence number rule, we know that any fragment 2372 * before `minseq' which hasn't arrived is never going to arrive. 2373 * The list of channels can't change because we have the receive 2374 * side of the ppp unit locked. 2375 */ 2376 list_for_each_entry(ch, &ppp->channels, clist) { 2377 if (seq_before(ch->lastseq, seq)) 2378 seq = ch->lastseq; 2379 } 2380 if (seq_before(ppp->minseq, seq)) 2381 ppp->minseq = seq; 2382 2383 /* Put the fragment on the reconstruction queue */ 2384 ppp_mp_insert(ppp, skb); 2385 2386 /* If the queue is getting long, don't wait any longer for packets 2387 before the start of the queue. */ 2388 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) { 2389 struct sk_buff *mskb = skb_peek(&ppp->mrq); 2390 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence)) 2391 ppp->minseq = PPP_MP_CB(mskb)->sequence; 2392 } 2393 2394 /* Pull completed packets off the queue and receive them. */ 2395 while ((skb = ppp_mp_reconstruct(ppp))) { 2396 if (pskb_may_pull(skb, 2)) 2397 ppp_receive_nonmp_frame(ppp, skb); 2398 else { 2399 ++ppp->dev->stats.rx_length_errors; 2400 kfree_skb(skb); 2401 ppp_receive_error(ppp); 2402 } 2403 } 2404 2405 return; 2406 2407 err: 2408 kfree_skb(skb); 2409 ppp_receive_error(ppp); 2410 } 2411 2412 /* 2413 * Insert a fragment on the MP reconstruction queue. 2414 * The queue is ordered by increasing sequence number. 2415 */ 2416 static void 2417 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb) 2418 { 2419 struct sk_buff *p; 2420 struct sk_buff_head *list = &ppp->mrq; 2421 u32 seq = PPP_MP_CB(skb)->sequence; 2422 2423 /* N.B. we don't need to lock the list lock because we have the 2424 ppp unit receive-side lock. */ 2425 skb_queue_walk(list, p) { 2426 if (seq_before(seq, PPP_MP_CB(p)->sequence)) 2427 break; 2428 } 2429 __skb_queue_before(list, p, skb); 2430 } 2431 2432 /* 2433 * Reconstruct a packet from the MP fragment queue. 2434 * We go through increasing sequence numbers until we find a 2435 * complete packet, or we get to the sequence number for a fragment 2436 * which hasn't arrived but might still do so. 2437 */ 2438 static struct sk_buff * 2439 ppp_mp_reconstruct(struct ppp *ppp) 2440 { 2441 u32 seq = ppp->nextseq; 2442 u32 minseq = ppp->minseq; 2443 struct sk_buff_head *list = &ppp->mrq; 2444 struct sk_buff *p, *tmp; 2445 struct sk_buff *head, *tail; 2446 struct sk_buff *skb = NULL; 2447 int lost = 0, len = 0; 2448 2449 if (ppp->mrru == 0) /* do nothing until mrru is set */ 2450 return NULL; 2451 head = __skb_peek(list); 2452 tail = NULL; 2453 skb_queue_walk_safe(list, p, tmp) { 2454 again: 2455 if (seq_before(PPP_MP_CB(p)->sequence, seq)) { 2456 /* this can't happen, anyway ignore the skb */ 2457 netdev_err(ppp->dev, "ppp_mp_reconstruct bad " 2458 "seq %u < %u\n", 2459 PPP_MP_CB(p)->sequence, seq); 2460 __skb_unlink(p, list); 2461 kfree_skb(p); 2462 continue; 2463 } 2464 if (PPP_MP_CB(p)->sequence != seq) { 2465 u32 oldseq; 2466 /* Fragment `seq' is missing. If it is after 2467 minseq, it might arrive later, so stop here. */ 2468 if (seq_after(seq, minseq)) 2469 break; 2470 /* Fragment `seq' is lost, keep going. */ 2471 lost = 1; 2472 oldseq = seq; 2473 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)? 2474 minseq + 1: PPP_MP_CB(p)->sequence; 2475 2476 if (ppp->debug & 1) 2477 netdev_printk(KERN_DEBUG, ppp->dev, 2478 "lost frag %u..%u\n", 2479 oldseq, seq-1); 2480 2481 goto again; 2482 } 2483 2484 /* 2485 * At this point we know that all the fragments from 2486 * ppp->nextseq to seq are either present or lost. 2487 * Also, there are no complete packets in the queue 2488 * that have no missing fragments and end before this 2489 * fragment. 2490 */ 2491 2492 /* B bit set indicates this fragment starts a packet */ 2493 if (PPP_MP_CB(p)->BEbits & B) { 2494 head = p; 2495 lost = 0; 2496 len = 0; 2497 } 2498 2499 len += p->len; 2500 2501 /* Got a complete packet yet? */ 2502 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) && 2503 (PPP_MP_CB(head)->BEbits & B)) { 2504 if (len > ppp->mrru + 2) { 2505 ++ppp->dev->stats.rx_length_errors; 2506 netdev_printk(KERN_DEBUG, ppp->dev, 2507 "PPP: reconstructed packet" 2508 " is too long (%d)\n", len); 2509 } else { 2510 tail = p; 2511 break; 2512 } 2513 ppp->nextseq = seq + 1; 2514 } 2515 2516 /* 2517 * If this is the ending fragment of a packet, 2518 * and we haven't found a complete valid packet yet, 2519 * we can discard up to and including this fragment. 2520 */ 2521 if (PPP_MP_CB(p)->BEbits & E) { 2522 struct sk_buff *tmp2; 2523 2524 skb_queue_reverse_walk_from_safe(list, p, tmp2) { 2525 if (ppp->debug & 1) 2526 netdev_printk(KERN_DEBUG, ppp->dev, 2527 "discarding frag %u\n", 2528 PPP_MP_CB(p)->sequence); 2529 __skb_unlink(p, list); 2530 kfree_skb(p); 2531 } 2532 head = skb_peek(list); 2533 if (!head) 2534 break; 2535 } 2536 ++seq; 2537 } 2538 2539 /* If we have a complete packet, copy it all into one skb. */ 2540 if (tail != NULL) { 2541 /* If we have discarded any fragments, 2542 signal a receive error. */ 2543 if (PPP_MP_CB(head)->sequence != ppp->nextseq) { 2544 skb_queue_walk_safe(list, p, tmp) { 2545 if (p == head) 2546 break; 2547 if (ppp->debug & 1) 2548 netdev_printk(KERN_DEBUG, ppp->dev, 2549 "discarding frag %u\n", 2550 PPP_MP_CB(p)->sequence); 2551 __skb_unlink(p, list); 2552 kfree_skb(p); 2553 } 2554 2555 if (ppp->debug & 1) 2556 netdev_printk(KERN_DEBUG, ppp->dev, 2557 " missed pkts %u..%u\n", 2558 ppp->nextseq, 2559 PPP_MP_CB(head)->sequence-1); 2560 ++ppp->dev->stats.rx_dropped; 2561 ppp_receive_error(ppp); 2562 } 2563 2564 skb = head; 2565 if (head != tail) { 2566 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list; 2567 p = skb_queue_next(list, head); 2568 __skb_unlink(skb, list); 2569 skb_queue_walk_from_safe(list, p, tmp) { 2570 __skb_unlink(p, list); 2571 *fragpp = p; 2572 p->next = NULL; 2573 fragpp = &p->next; 2574 2575 skb->len += p->len; 2576 skb->data_len += p->len; 2577 skb->truesize += p->truesize; 2578 2579 if (p == tail) 2580 break; 2581 } 2582 } else { 2583 __skb_unlink(skb, list); 2584 } 2585 2586 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1; 2587 } 2588 2589 return skb; 2590 } 2591 #endif /* CONFIG_PPP_MULTILINK */ 2592 2593 /* 2594 * Channel interface. 2595 */ 2596 2597 /* Create a new, unattached ppp channel. */ 2598 int ppp_register_channel(struct ppp_channel *chan) 2599 { 2600 return ppp_register_net_channel(current->nsproxy->net_ns, chan); 2601 } 2602 2603 /* Create a new, unattached ppp channel for specified net. */ 2604 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan) 2605 { 2606 struct channel *pch; 2607 struct ppp_net *pn; 2608 2609 pch = kzalloc(sizeof(struct channel), GFP_KERNEL); 2610 if (!pch) 2611 return -ENOMEM; 2612 2613 pn = ppp_pernet(net); 2614 2615 pch->ppp = NULL; 2616 pch->chan = chan; 2617 pch->chan_net = get_net(net); 2618 chan->ppp = pch; 2619 init_ppp_file(&pch->file, CHANNEL); 2620 pch->file.hdrlen = chan->hdrlen; 2621 #ifdef CONFIG_PPP_MULTILINK 2622 pch->lastseq = -1; 2623 #endif /* CONFIG_PPP_MULTILINK */ 2624 init_rwsem(&pch->chan_sem); 2625 spin_lock_init(&pch->downl); 2626 rwlock_init(&pch->upl); 2627 2628 spin_lock_bh(&pn->all_channels_lock); 2629 pch->file.index = ++pn->last_channel_index; 2630 list_add(&pch->list, &pn->new_channels); 2631 atomic_inc(&channel_count); 2632 spin_unlock_bh(&pn->all_channels_lock); 2633 2634 return 0; 2635 } 2636 2637 /* 2638 * Return the index of a channel. 2639 */ 2640 int ppp_channel_index(struct ppp_channel *chan) 2641 { 2642 struct channel *pch = chan->ppp; 2643 2644 if (pch) 2645 return pch->file.index; 2646 return -1; 2647 } 2648 2649 /* 2650 * Return the PPP unit number to which a channel is connected. 2651 */ 2652 int ppp_unit_number(struct ppp_channel *chan) 2653 { 2654 struct channel *pch = chan->ppp; 2655 int unit = -1; 2656 2657 if (pch) { 2658 read_lock_bh(&pch->upl); 2659 if (pch->ppp) 2660 unit = pch->ppp->file.index; 2661 read_unlock_bh(&pch->upl); 2662 } 2663 return unit; 2664 } 2665 2666 /* 2667 * Return the PPP device interface name of a channel. 2668 */ 2669 char *ppp_dev_name(struct ppp_channel *chan) 2670 { 2671 struct channel *pch = chan->ppp; 2672 char *name = NULL; 2673 2674 if (pch) { 2675 read_lock_bh(&pch->upl); 2676 if (pch->ppp && pch->ppp->dev) 2677 name = pch->ppp->dev->name; 2678 read_unlock_bh(&pch->upl); 2679 } 2680 return name; 2681 } 2682 2683 2684 /* 2685 * Disconnect a channel from the generic layer. 2686 * This must be called in process context. 2687 */ 2688 void 2689 ppp_unregister_channel(struct ppp_channel *chan) 2690 { 2691 struct channel *pch = chan->ppp; 2692 struct ppp_net *pn; 2693 2694 if (!pch) 2695 return; /* should never happen */ 2696 2697 chan->ppp = NULL; 2698 2699 /* 2700 * This ensures that we have returned from any calls into the 2701 * the channel's start_xmit or ioctl routine before we proceed. 2702 */ 2703 down_write(&pch->chan_sem); 2704 spin_lock_bh(&pch->downl); 2705 pch->chan = NULL; 2706 spin_unlock_bh(&pch->downl); 2707 up_write(&pch->chan_sem); 2708 ppp_disconnect_channel(pch); 2709 2710 pn = ppp_pernet(pch->chan_net); 2711 spin_lock_bh(&pn->all_channels_lock); 2712 list_del(&pch->list); 2713 spin_unlock_bh(&pn->all_channels_lock); 2714 2715 pch->file.dead = 1; 2716 wake_up_interruptible(&pch->file.rwait); 2717 if (refcount_dec_and_test(&pch->file.refcnt)) 2718 ppp_destroy_channel(pch); 2719 } 2720 2721 /* 2722 * Callback from a channel when it can accept more to transmit. 2723 * This should be called at BH/softirq level, not interrupt level. 2724 */ 2725 void 2726 ppp_output_wakeup(struct ppp_channel *chan) 2727 { 2728 struct channel *pch = chan->ppp; 2729 2730 if (!pch) 2731 return; 2732 ppp_channel_push(pch); 2733 } 2734 2735 /* 2736 * Compression control. 2737 */ 2738 2739 /* Process the PPPIOCSCOMPRESS ioctl. */ 2740 static int 2741 ppp_set_compress(struct ppp *ppp, unsigned long arg) 2742 { 2743 int err; 2744 struct compressor *cp, *ocomp; 2745 struct ppp_option_data data; 2746 void *state, *ostate; 2747 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH]; 2748 2749 err = -EFAULT; 2750 if (copy_from_user(&data, (void __user *) arg, sizeof(data))) 2751 goto out; 2752 if (data.length > CCP_MAX_OPTION_LENGTH) 2753 goto out; 2754 if (copy_from_user(ccp_option, (void __user *) data.ptr, data.length)) 2755 goto out; 2756 2757 err = -EINVAL; 2758 if (data.length < 2 || ccp_option[1] < 2 || ccp_option[1] > data.length) 2759 goto out; 2760 2761 cp = try_then_request_module( 2762 find_compressor(ccp_option[0]), 2763 "ppp-compress-%d", ccp_option[0]); 2764 if (!cp) 2765 goto out; 2766 2767 err = -ENOBUFS; 2768 if (data.transmit) { 2769 state = cp->comp_alloc(ccp_option, data.length); 2770 if (state) { 2771 ppp_xmit_lock(ppp); 2772 ppp->xstate &= ~SC_COMP_RUN; 2773 ocomp = ppp->xcomp; 2774 ostate = ppp->xc_state; 2775 ppp->xcomp = cp; 2776 ppp->xc_state = state; 2777 ppp_xmit_unlock(ppp); 2778 if (ostate) { 2779 ocomp->comp_free(ostate); 2780 module_put(ocomp->owner); 2781 } 2782 err = 0; 2783 } else 2784 module_put(cp->owner); 2785 2786 } else { 2787 state = cp->decomp_alloc(ccp_option, data.length); 2788 if (state) { 2789 ppp_recv_lock(ppp); 2790 ppp->rstate &= ~SC_DECOMP_RUN; 2791 ocomp = ppp->rcomp; 2792 ostate = ppp->rc_state; 2793 ppp->rcomp = cp; 2794 ppp->rc_state = state; 2795 ppp_recv_unlock(ppp); 2796 if (ostate) { 2797 ocomp->decomp_free(ostate); 2798 module_put(ocomp->owner); 2799 } 2800 err = 0; 2801 } else 2802 module_put(cp->owner); 2803 } 2804 2805 out: 2806 return err; 2807 } 2808 2809 /* 2810 * Look at a CCP packet and update our state accordingly. 2811 * We assume the caller has the xmit or recv path locked. 2812 */ 2813 static void 2814 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound) 2815 { 2816 unsigned char *dp; 2817 int len; 2818 2819 if (!pskb_may_pull(skb, CCP_HDRLEN + 2)) 2820 return; /* no header */ 2821 dp = skb->data + 2; 2822 2823 switch (CCP_CODE(dp)) { 2824 case CCP_CONFREQ: 2825 2826 /* A ConfReq starts negotiation of compression 2827 * in one direction of transmission, 2828 * and hence brings it down...but which way? 2829 * 2830 * Remember: 2831 * A ConfReq indicates what the sender would like to receive 2832 */ 2833 if(inbound) 2834 /* He is proposing what I should send */ 2835 ppp->xstate &= ~SC_COMP_RUN; 2836 else 2837 /* I am proposing to what he should send */ 2838 ppp->rstate &= ~SC_DECOMP_RUN; 2839 2840 break; 2841 2842 case CCP_TERMREQ: 2843 case CCP_TERMACK: 2844 /* 2845 * CCP is going down, both directions of transmission 2846 */ 2847 ppp->rstate &= ~SC_DECOMP_RUN; 2848 ppp->xstate &= ~SC_COMP_RUN; 2849 break; 2850 2851 case CCP_CONFACK: 2852 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN) 2853 break; 2854 len = CCP_LENGTH(dp); 2855 if (!pskb_may_pull(skb, len + 2)) 2856 return; /* too short */ 2857 dp += CCP_HDRLEN; 2858 len -= CCP_HDRLEN; 2859 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp)) 2860 break; 2861 if (inbound) { 2862 /* we will start receiving compressed packets */ 2863 if (!ppp->rc_state) 2864 break; 2865 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len, 2866 ppp->file.index, 0, ppp->mru, ppp->debug)) { 2867 ppp->rstate |= SC_DECOMP_RUN; 2868 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR); 2869 } 2870 } else { 2871 /* we will soon start sending compressed packets */ 2872 if (!ppp->xc_state) 2873 break; 2874 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len, 2875 ppp->file.index, 0, ppp->debug)) 2876 ppp->xstate |= SC_COMP_RUN; 2877 } 2878 break; 2879 2880 case CCP_RESETACK: 2881 /* reset the [de]compressor */ 2882 if ((ppp->flags & SC_CCP_UP) == 0) 2883 break; 2884 if (inbound) { 2885 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) { 2886 ppp->rcomp->decomp_reset(ppp->rc_state); 2887 ppp->rstate &= ~SC_DC_ERROR; 2888 } 2889 } else { 2890 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN)) 2891 ppp->xcomp->comp_reset(ppp->xc_state); 2892 } 2893 break; 2894 } 2895 } 2896 2897 /* Free up compression resources. */ 2898 static void 2899 ppp_ccp_closed(struct ppp *ppp) 2900 { 2901 void *xstate, *rstate; 2902 struct compressor *xcomp, *rcomp; 2903 2904 ppp_lock(ppp); 2905 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP); 2906 ppp->xstate = 0; 2907 xcomp = ppp->xcomp; 2908 xstate = ppp->xc_state; 2909 ppp->xc_state = NULL; 2910 ppp->rstate = 0; 2911 rcomp = ppp->rcomp; 2912 rstate = ppp->rc_state; 2913 ppp->rc_state = NULL; 2914 ppp_unlock(ppp); 2915 2916 if (xstate) { 2917 xcomp->comp_free(xstate); 2918 module_put(xcomp->owner); 2919 } 2920 if (rstate) { 2921 rcomp->decomp_free(rstate); 2922 module_put(rcomp->owner); 2923 } 2924 } 2925 2926 /* List of compressors. */ 2927 static LIST_HEAD(compressor_list); 2928 static DEFINE_SPINLOCK(compressor_list_lock); 2929 2930 struct compressor_entry { 2931 struct list_head list; 2932 struct compressor *comp; 2933 }; 2934 2935 static struct compressor_entry * 2936 find_comp_entry(int proto) 2937 { 2938 struct compressor_entry *ce; 2939 2940 list_for_each_entry(ce, &compressor_list, list) { 2941 if (ce->comp->compress_proto == proto) 2942 return ce; 2943 } 2944 return NULL; 2945 } 2946 2947 /* Register a compressor */ 2948 int 2949 ppp_register_compressor(struct compressor *cp) 2950 { 2951 struct compressor_entry *ce; 2952 int ret; 2953 spin_lock(&compressor_list_lock); 2954 ret = -EEXIST; 2955 if (find_comp_entry(cp->compress_proto)) 2956 goto out; 2957 ret = -ENOMEM; 2958 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC); 2959 if (!ce) 2960 goto out; 2961 ret = 0; 2962 ce->comp = cp; 2963 list_add(&ce->list, &compressor_list); 2964 out: 2965 spin_unlock(&compressor_list_lock); 2966 return ret; 2967 } 2968 2969 /* Unregister a compressor */ 2970 void 2971 ppp_unregister_compressor(struct compressor *cp) 2972 { 2973 struct compressor_entry *ce; 2974 2975 spin_lock(&compressor_list_lock); 2976 ce = find_comp_entry(cp->compress_proto); 2977 if (ce && ce->comp == cp) { 2978 list_del(&ce->list); 2979 kfree(ce); 2980 } 2981 spin_unlock(&compressor_list_lock); 2982 } 2983 2984 /* Find a compressor. */ 2985 static struct compressor * 2986 find_compressor(int type) 2987 { 2988 struct compressor_entry *ce; 2989 struct compressor *cp = NULL; 2990 2991 spin_lock(&compressor_list_lock); 2992 ce = find_comp_entry(type); 2993 if (ce) { 2994 cp = ce->comp; 2995 if (!try_module_get(cp->owner)) 2996 cp = NULL; 2997 } 2998 spin_unlock(&compressor_list_lock); 2999 return cp; 3000 } 3001 3002 /* 3003 * Miscelleneous stuff. 3004 */ 3005 3006 static void 3007 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st) 3008 { 3009 struct slcompress *vj = ppp->vj; 3010 3011 memset(st, 0, sizeof(*st)); 3012 st->p.ppp_ipackets = ppp->stats64.rx_packets; 3013 st->p.ppp_ierrors = ppp->dev->stats.rx_errors; 3014 st->p.ppp_ibytes = ppp->stats64.rx_bytes; 3015 st->p.ppp_opackets = ppp->stats64.tx_packets; 3016 st->p.ppp_oerrors = ppp->dev->stats.tx_errors; 3017 st->p.ppp_obytes = ppp->stats64.tx_bytes; 3018 if (!vj) 3019 return; 3020 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed; 3021 st->vj.vjs_compressed = vj->sls_o_compressed; 3022 st->vj.vjs_searches = vj->sls_o_searches; 3023 st->vj.vjs_misses = vj->sls_o_misses; 3024 st->vj.vjs_errorin = vj->sls_i_error; 3025 st->vj.vjs_tossed = vj->sls_i_tossed; 3026 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed; 3027 st->vj.vjs_compressedin = vj->sls_i_compressed; 3028 } 3029 3030 /* 3031 * Stuff for handling the lists of ppp units and channels 3032 * and for initialization. 3033 */ 3034 3035 /* 3036 * Create a new ppp interface unit. Fails if it can't allocate memory 3037 * or if there is already a unit with the requested number. 3038 * unit == -1 means allocate a new number. 3039 */ 3040 static int ppp_create_interface(struct net *net, struct file *file, int *unit) 3041 { 3042 struct ppp_config conf = { 3043 .file = file, 3044 .unit = *unit, 3045 .ifname_is_set = false, 3046 }; 3047 struct net_device *dev; 3048 struct ppp *ppp; 3049 int err; 3050 3051 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup); 3052 if (!dev) { 3053 err = -ENOMEM; 3054 goto err; 3055 } 3056 dev_net_set(dev, net); 3057 dev->rtnl_link_ops = &ppp_link_ops; 3058 3059 rtnl_lock(); 3060 3061 err = ppp_dev_configure(net, dev, &conf); 3062 if (err < 0) 3063 goto err_dev; 3064 ppp = netdev_priv(dev); 3065 *unit = ppp->file.index; 3066 3067 rtnl_unlock(); 3068 3069 return 0; 3070 3071 err_dev: 3072 rtnl_unlock(); 3073 free_netdev(dev); 3074 err: 3075 return err; 3076 } 3077 3078 /* 3079 * Initialize a ppp_file structure. 3080 */ 3081 static void 3082 init_ppp_file(struct ppp_file *pf, int kind) 3083 { 3084 pf->kind = kind; 3085 skb_queue_head_init(&pf->xq); 3086 skb_queue_head_init(&pf->rq); 3087 refcount_set(&pf->refcnt, 1); 3088 init_waitqueue_head(&pf->rwait); 3089 } 3090 3091 /* 3092 * Free the memory used by a ppp unit. This is only called once 3093 * there are no channels connected to the unit and no file structs 3094 * that reference the unit. 3095 */ 3096 static void ppp_destroy_interface(struct ppp *ppp) 3097 { 3098 atomic_dec(&ppp_unit_count); 3099 3100 if (!ppp->file.dead || ppp->n_channels) { 3101 /* "can't happen" */ 3102 netdev_err(ppp->dev, "ppp: destroying ppp struct %p " 3103 "but dead=%d n_channels=%d !\n", 3104 ppp, ppp->file.dead, ppp->n_channels); 3105 return; 3106 } 3107 3108 ppp_ccp_closed(ppp); 3109 if (ppp->vj) { 3110 slhc_free(ppp->vj); 3111 ppp->vj = NULL; 3112 } 3113 skb_queue_purge(&ppp->file.xq); 3114 skb_queue_purge(&ppp->file.rq); 3115 #ifdef CONFIG_PPP_MULTILINK 3116 skb_queue_purge(&ppp->mrq); 3117 #endif /* CONFIG_PPP_MULTILINK */ 3118 #ifdef CONFIG_PPP_FILTER 3119 if (ppp->pass_filter) { 3120 bpf_prog_destroy(ppp->pass_filter); 3121 ppp->pass_filter = NULL; 3122 } 3123 3124 if (ppp->active_filter) { 3125 bpf_prog_destroy(ppp->active_filter); 3126 ppp->active_filter = NULL; 3127 } 3128 #endif /* CONFIG_PPP_FILTER */ 3129 3130 kfree_skb(ppp->xmit_pending); 3131 free_percpu(ppp->xmit_recursion); 3132 3133 free_netdev(ppp->dev); 3134 } 3135 3136 /* 3137 * Locate an existing ppp unit. 3138 * The caller should have locked the all_ppp_mutex. 3139 */ 3140 static struct ppp * 3141 ppp_find_unit(struct ppp_net *pn, int unit) 3142 { 3143 return unit_find(&pn->units_idr, unit); 3144 } 3145 3146 /* 3147 * Locate an existing ppp channel. 3148 * The caller should have locked the all_channels_lock. 3149 * First we look in the new_channels list, then in the 3150 * all_channels list. If found in the new_channels list, 3151 * we move it to the all_channels list. This is for speed 3152 * when we have a lot of channels in use. 3153 */ 3154 static struct channel * 3155 ppp_find_channel(struct ppp_net *pn, int unit) 3156 { 3157 struct channel *pch; 3158 3159 list_for_each_entry(pch, &pn->new_channels, list) { 3160 if (pch->file.index == unit) { 3161 list_move(&pch->list, &pn->all_channels); 3162 return pch; 3163 } 3164 } 3165 3166 list_for_each_entry(pch, &pn->all_channels, list) { 3167 if (pch->file.index == unit) 3168 return pch; 3169 } 3170 3171 return NULL; 3172 } 3173 3174 /* 3175 * Connect a PPP channel to a PPP interface unit. 3176 */ 3177 static int 3178 ppp_connect_channel(struct channel *pch, int unit) 3179 { 3180 struct ppp *ppp; 3181 struct ppp_net *pn; 3182 int ret = -ENXIO; 3183 int hdrlen; 3184 3185 pn = ppp_pernet(pch->chan_net); 3186 3187 mutex_lock(&pn->all_ppp_mutex); 3188 ppp = ppp_find_unit(pn, unit); 3189 if (!ppp) 3190 goto out; 3191 write_lock_bh(&pch->upl); 3192 ret = -EINVAL; 3193 if (pch->ppp) 3194 goto outl; 3195 3196 ppp_lock(ppp); 3197 spin_lock_bh(&pch->downl); 3198 if (!pch->chan) { 3199 /* Don't connect unregistered channels */ 3200 spin_unlock_bh(&pch->downl); 3201 ppp_unlock(ppp); 3202 ret = -ENOTCONN; 3203 goto outl; 3204 } 3205 spin_unlock_bh(&pch->downl); 3206 if (pch->file.hdrlen > ppp->file.hdrlen) 3207 ppp->file.hdrlen = pch->file.hdrlen; 3208 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */ 3209 if (hdrlen > ppp->dev->hard_header_len) 3210 ppp->dev->hard_header_len = hdrlen; 3211 list_add_tail(&pch->clist, &ppp->channels); 3212 ++ppp->n_channels; 3213 pch->ppp = ppp; 3214 refcount_inc(&ppp->file.refcnt); 3215 ppp_unlock(ppp); 3216 ret = 0; 3217 3218 outl: 3219 write_unlock_bh(&pch->upl); 3220 out: 3221 mutex_unlock(&pn->all_ppp_mutex); 3222 return ret; 3223 } 3224 3225 /* 3226 * Disconnect a channel from its ppp unit. 3227 */ 3228 static int 3229 ppp_disconnect_channel(struct channel *pch) 3230 { 3231 struct ppp *ppp; 3232 int err = -EINVAL; 3233 3234 write_lock_bh(&pch->upl); 3235 ppp = pch->ppp; 3236 pch->ppp = NULL; 3237 write_unlock_bh(&pch->upl); 3238 if (ppp) { 3239 /* remove it from the ppp unit's list */ 3240 ppp_lock(ppp); 3241 list_del(&pch->clist); 3242 if (--ppp->n_channels == 0) 3243 wake_up_interruptible(&ppp->file.rwait); 3244 ppp_unlock(ppp); 3245 if (refcount_dec_and_test(&ppp->file.refcnt)) 3246 ppp_destroy_interface(ppp); 3247 err = 0; 3248 } 3249 return err; 3250 } 3251 3252 /* 3253 * Free up the resources used by a ppp channel. 3254 */ 3255 static void ppp_destroy_channel(struct channel *pch) 3256 { 3257 put_net(pch->chan_net); 3258 pch->chan_net = NULL; 3259 3260 atomic_dec(&channel_count); 3261 3262 if (!pch->file.dead) { 3263 /* "can't happen" */ 3264 pr_err("ppp: destroying undead channel %p !\n", pch); 3265 return; 3266 } 3267 skb_queue_purge(&pch->file.xq); 3268 skb_queue_purge(&pch->file.rq); 3269 kfree(pch); 3270 } 3271 3272 static void __exit ppp_cleanup(void) 3273 { 3274 /* should never happen */ 3275 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count)) 3276 pr_err("PPP: removing module but units remain!\n"); 3277 rtnl_link_unregister(&ppp_link_ops); 3278 unregister_chrdev(PPP_MAJOR, "ppp"); 3279 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0)); 3280 class_destroy(ppp_class); 3281 unregister_pernet_device(&ppp_net_ops); 3282 } 3283 3284 /* 3285 * Units handling. Caller must protect concurrent access 3286 * by holding all_ppp_mutex 3287 */ 3288 3289 /* associate pointer with specified number */ 3290 static int unit_set(struct idr *p, void *ptr, int n) 3291 { 3292 int unit; 3293 3294 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL); 3295 if (unit == -ENOSPC) 3296 unit = -EINVAL; 3297 return unit; 3298 } 3299 3300 /* get new free unit number and associate pointer with it */ 3301 static int unit_get(struct idr *p, void *ptr) 3302 { 3303 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL); 3304 } 3305 3306 /* put unit number back to a pool */ 3307 static void unit_put(struct idr *p, int n) 3308 { 3309 idr_remove(p, n); 3310 } 3311 3312 /* get pointer associated with the number */ 3313 static void *unit_find(struct idr *p, int n) 3314 { 3315 return idr_find(p, n); 3316 } 3317 3318 /* Module/initialization stuff */ 3319 3320 module_init(ppp_init); 3321 module_exit(ppp_cleanup); 3322 3323 EXPORT_SYMBOL(ppp_register_net_channel); 3324 EXPORT_SYMBOL(ppp_register_channel); 3325 EXPORT_SYMBOL(ppp_unregister_channel); 3326 EXPORT_SYMBOL(ppp_channel_index); 3327 EXPORT_SYMBOL(ppp_unit_number); 3328 EXPORT_SYMBOL(ppp_dev_name); 3329 EXPORT_SYMBOL(ppp_input); 3330 EXPORT_SYMBOL(ppp_input_error); 3331 EXPORT_SYMBOL(ppp_output_wakeup); 3332 EXPORT_SYMBOL(ppp_register_compressor); 3333 EXPORT_SYMBOL(ppp_unregister_compressor); 3334 MODULE_LICENSE("GPL"); 3335 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0); 3336 MODULE_ALIAS_RTNL_LINK("ppp"); 3337 MODULE_ALIAS("devname:ppp"); 3338