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