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