1 /* 2 * Generic PPP layer for Linux. 3 * 4 * Copyright 1999-2002 Paul Mackerras. 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 * 11 * The generic PPP layer handles the PPP network interfaces, the 12 * /dev/ppp device, packet and VJ compression, and multilink. 13 * It talks to PPP `channels' via the interface defined in 14 * include/linux/ppp_channel.h. Channels provide the basic means for 15 * sending and receiving PPP frames on some kind of communications 16 * channel. 17 * 18 * Part of the code in this driver was inspired by the old async-only 19 * PPP driver, written by Michael Callahan and Al Longyear, and 20 * subsequently hacked by Paul Mackerras. 21 * 22 * ==FILEVERSION 20041108== 23 */ 24 25 #include <linux/module.h> 26 #include <linux/kernel.h> 27 #include <linux/sched/signal.h> 28 #include <linux/kmod.h> 29 #include <linux/init.h> 30 #include <linux/list.h> 31 #include <linux/idr.h> 32 #include <linux/netdevice.h> 33 #include <linux/poll.h> 34 #include <linux/ppp_defs.h> 35 #include <linux/filter.h> 36 #include <linux/ppp-ioctl.h> 37 #include <linux/ppp_channel.h> 38 #include <linux/ppp-comp.h> 39 #include <linux/skbuff.h> 40 #include <linux/rtnetlink.h> 41 #include <linux/if_arp.h> 42 #include <linux/ip.h> 43 #include <linux/tcp.h> 44 #include <linux/spinlock.h> 45 #include <linux/rwsem.h> 46 #include <linux/stddef.h> 47 #include <linux/device.h> 48 #include <linux/mutex.h> 49 #include <linux/slab.h> 50 #include <linux/file.h> 51 #include <asm/unaligned.h> 52 #include <net/slhc_vj.h> 53 #include <linux/atomic.h> 54 #include <linux/refcount.h> 55 56 #include <linux/nsproxy.h> 57 #include <net/net_namespace.h> 58 #include <net/netns/generic.h> 59 60 #define PPP_VERSION "2.4.2" 61 62 /* 63 * Network protocols we support. 64 */ 65 #define NP_IP 0 /* Internet Protocol V4 */ 66 #define NP_IPV6 1 /* Internet Protocol V6 */ 67 #define NP_IPX 2 /* IPX protocol */ 68 #define NP_AT 3 /* Appletalk protocol */ 69 #define NP_MPLS_UC 4 /* MPLS unicast */ 70 #define NP_MPLS_MC 5 /* MPLS multicast */ 71 #define NUM_NP 6 /* Number of NPs. */ 72 73 #define MPHDRLEN 6 /* multilink protocol header length */ 74 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */ 75 76 /* 77 * An instance of /dev/ppp can be associated with either a ppp 78 * interface unit or a ppp channel. In both cases, file->private_data 79 * points to one of these. 80 */ 81 struct ppp_file { 82 enum { 83 INTERFACE=1, CHANNEL 84 } kind; 85 struct sk_buff_head xq; /* pppd transmit queue */ 86 struct sk_buff_head rq; /* receive queue for pppd */ 87 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */ 88 refcount_t refcnt; /* # refs (incl /dev/ppp attached) */ 89 int hdrlen; /* space to leave for headers */ 90 int index; /* interface unit / channel number */ 91 int dead; /* unit/channel has been shut down */ 92 }; 93 94 #define PF_TO_X(pf, X) container_of(pf, X, file) 95 96 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp) 97 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel) 98 99 /* 100 * Data structure to hold primary network stats for which 101 * we want to use 64 bit storage. Other network stats 102 * are stored in dev->stats of the ppp strucute. 103 */ 104 struct ppp_link_stats { 105 u64 rx_packets; 106 u64 tx_packets; 107 u64 rx_bytes; 108 u64 tx_bytes; 109 }; 110 111 /* 112 * Data structure describing one ppp unit. 113 * A ppp unit corresponds to a ppp network interface device 114 * and represents a multilink bundle. 115 * It can have 0 or more ppp channels connected to it. 116 */ 117 struct ppp { 118 struct ppp_file file; /* stuff for read/write/poll 0 */ 119 struct file *owner; /* file that owns this unit 48 */ 120 struct list_head channels; /* list of attached channels 4c */ 121 int n_channels; /* how many channels are attached 54 */ 122 spinlock_t rlock; /* lock for receive side 58 */ 123 spinlock_t wlock; /* lock for transmit side 5c */ 124 int __percpu *xmit_recursion; /* xmit recursion detect */ 125 int mru; /* max receive unit 60 */ 126 unsigned int flags; /* control bits 64 */ 127 unsigned int xstate; /* transmit state bits 68 */ 128 unsigned int rstate; /* receive state bits 6c */ 129 int debug; /* debug flags 70 */ 130 struct slcompress *vj; /* state for VJ header compression */ 131 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */ 132 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */ 133 struct compressor *xcomp; /* transmit packet compressor 8c */ 134 void *xc_state; /* its internal state 90 */ 135 struct compressor *rcomp; /* receive decompressor 94 */ 136 void *rc_state; /* its internal state 98 */ 137 unsigned long last_xmit; /* jiffies when last pkt sent 9c */ 138 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */ 139 struct net_device *dev; /* network interface device a4 */ 140 int closing; /* is device closing down? a8 */ 141 #ifdef CONFIG_PPP_MULTILINK 142 int nxchan; /* next channel to send something on */ 143 u32 nxseq; /* next sequence number to send */ 144 int mrru; /* MP: max reconst. receive unit */ 145 u32 nextseq; /* MP: seq no of next packet */ 146 u32 minseq; /* MP: min of most recent seqnos */ 147 struct sk_buff_head mrq; /* MP: receive reconstruction queue */ 148 #endif /* CONFIG_PPP_MULTILINK */ 149 #ifdef CONFIG_PPP_FILTER 150 struct bpf_prog *pass_filter; /* filter for packets to pass */ 151 struct bpf_prog *active_filter; /* filter for pkts to reset idle */ 152 #endif /* CONFIG_PPP_FILTER */ 153 struct net *ppp_net; /* the net we belong to */ 154 struct ppp_link_stats stats64; /* 64 bit network stats */ 155 }; 156 157 /* 158 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC, 159 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP, 160 * SC_MUST_COMP 161 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR. 162 * Bits in xstate: SC_COMP_RUN 163 */ 164 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \ 165 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \ 166 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP) 167 168 /* 169 * Private data structure for each channel. 170 * This includes the data structure used for multilink. 171 */ 172 struct channel { 173 struct ppp_file file; /* stuff for read/write/poll */ 174 struct list_head list; /* link in all/new_channels list */ 175 struct ppp_channel *chan; /* public channel data structure */ 176 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */ 177 spinlock_t downl; /* protects `chan', file.xq dequeue */ 178 struct ppp *ppp; /* ppp unit we're connected to */ 179 struct net *chan_net; /* the net channel belongs to */ 180 struct list_head clist; /* link in list of channels per unit */ 181 rwlock_t upl; /* protects `ppp' */ 182 #ifdef CONFIG_PPP_MULTILINK 183 u8 avail; /* flag used in multilink stuff */ 184 u8 had_frag; /* >= 1 fragments have been sent */ 185 u32 lastseq; /* MP: last sequence # received */ 186 int speed; /* speed of the corresponding ppp channel*/ 187 #endif /* CONFIG_PPP_MULTILINK */ 188 }; 189 190 struct ppp_config { 191 struct file *file; 192 s32 unit; 193 bool ifname_is_set; 194 }; 195 196 /* 197 * SMP locking issues: 198 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels 199 * list and the ppp.n_channels field, you need to take both locks 200 * before you modify them. 201 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock -> 202 * channel.downl. 203 */ 204 205 static DEFINE_MUTEX(ppp_mutex); 206 static atomic_t ppp_unit_count = ATOMIC_INIT(0); 207 static atomic_t channel_count = ATOMIC_INIT(0); 208 209 /* per-net private data for this module */ 210 static unsigned int ppp_net_id __read_mostly; 211 struct ppp_net { 212 /* units to ppp mapping */ 213 struct idr units_idr; 214 215 /* 216 * all_ppp_mutex protects the units_idr mapping. 217 * It also ensures that finding a ppp unit in the units_idr 218 * map and updating its file.refcnt field is atomic. 219 */ 220 struct mutex all_ppp_mutex; 221 222 /* channels */ 223 struct list_head all_channels; 224 struct list_head new_channels; 225 int last_channel_index; 226 227 /* 228 * all_channels_lock protects all_channels and 229 * last_channel_index, and the atomicity of find 230 * a channel and updating its file.refcnt field. 231 */ 232 spinlock_t all_channels_lock; 233 }; 234 235 /* Get the PPP protocol number from a skb */ 236 #define PPP_PROTO(skb) get_unaligned_be16((skb)->data) 237 238 /* We limit the length of ppp->file.rq to this (arbitrary) value */ 239 #define PPP_MAX_RQLEN 32 240 241 /* 242 * Maximum number of multilink fragments queued up. 243 * This has to be large enough to cope with the maximum latency of 244 * the slowest channel relative to the others. Strictly it should 245 * depend on the number of channels and their characteristics. 246 */ 247 #define PPP_MP_MAX_QLEN 128 248 249 /* Multilink header bits. */ 250 #define B 0x80 /* this fragment begins a packet */ 251 #define E 0x40 /* this fragment ends a packet */ 252 253 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */ 254 #define seq_before(a, b) ((s32)((a) - (b)) < 0) 255 #define seq_after(a, b) ((s32)((a) - (b)) > 0) 256 257 /* Prototypes. */ 258 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 259 struct file *file, unsigned int cmd, unsigned long arg); 260 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb); 261 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb); 262 static void ppp_push(struct ppp *ppp); 263 static void ppp_channel_push(struct channel *pch); 264 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, 265 struct channel *pch); 266 static void ppp_receive_error(struct ppp *ppp); 267 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb); 268 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp, 269 struct sk_buff *skb); 270 #ifdef CONFIG_PPP_MULTILINK 271 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, 272 struct channel *pch); 273 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb); 274 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp); 275 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb); 276 #endif /* CONFIG_PPP_MULTILINK */ 277 static int ppp_set_compress(struct ppp *ppp, unsigned long arg); 278 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound); 279 static void ppp_ccp_closed(struct ppp *ppp); 280 static struct compressor *find_compressor(int type); 281 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st); 282 static int ppp_create_interface(struct net *net, struct file *file, int *unit); 283 static void init_ppp_file(struct ppp_file *pf, int kind); 284 static void ppp_destroy_interface(struct ppp *ppp); 285 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit); 286 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit); 287 static int ppp_connect_channel(struct channel *pch, int unit); 288 static int ppp_disconnect_channel(struct channel *pch); 289 static void ppp_destroy_channel(struct channel *pch); 290 static int unit_get(struct idr *p, void *ptr); 291 static int unit_set(struct idr *p, void *ptr, int n); 292 static void unit_put(struct idr *p, int n); 293 static void *unit_find(struct idr *p, int n); 294 static void ppp_setup(struct net_device *dev); 295 296 static const struct net_device_ops ppp_netdev_ops; 297 298 static struct class *ppp_class; 299 300 /* per net-namespace data */ 301 static inline struct ppp_net *ppp_pernet(struct net *net) 302 { 303 BUG_ON(!net); 304 305 return net_generic(net, ppp_net_id); 306 } 307 308 /* Translates a PPP protocol number to a NP index (NP == network protocol) */ 309 static inline int proto_to_npindex(int proto) 310 { 311 switch (proto) { 312 case PPP_IP: 313 return NP_IP; 314 case PPP_IPV6: 315 return NP_IPV6; 316 case PPP_IPX: 317 return NP_IPX; 318 case PPP_AT: 319 return NP_AT; 320 case PPP_MPLS_UC: 321 return NP_MPLS_UC; 322 case PPP_MPLS_MC: 323 return NP_MPLS_MC; 324 } 325 return -EINVAL; 326 } 327 328 /* Translates an NP index into a PPP protocol number */ 329 static const int npindex_to_proto[NUM_NP] = { 330 PPP_IP, 331 PPP_IPV6, 332 PPP_IPX, 333 PPP_AT, 334 PPP_MPLS_UC, 335 PPP_MPLS_MC, 336 }; 337 338 /* Translates an ethertype into an NP index */ 339 static inline int ethertype_to_npindex(int ethertype) 340 { 341 switch (ethertype) { 342 case ETH_P_IP: 343 return NP_IP; 344 case ETH_P_IPV6: 345 return NP_IPV6; 346 case ETH_P_IPX: 347 return NP_IPX; 348 case ETH_P_PPPTALK: 349 case ETH_P_ATALK: 350 return NP_AT; 351 case ETH_P_MPLS_UC: 352 return NP_MPLS_UC; 353 case ETH_P_MPLS_MC: 354 return NP_MPLS_MC; 355 } 356 return -1; 357 } 358 359 /* Translates an NP index into an ethertype */ 360 static const int npindex_to_ethertype[NUM_NP] = { 361 ETH_P_IP, 362 ETH_P_IPV6, 363 ETH_P_IPX, 364 ETH_P_PPPTALK, 365 ETH_P_MPLS_UC, 366 ETH_P_MPLS_MC, 367 }; 368 369 /* 370 * Locking shorthand. 371 */ 372 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock) 373 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock) 374 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock) 375 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock) 376 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \ 377 ppp_recv_lock(ppp); } while (0) 378 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \ 379 ppp_xmit_unlock(ppp); } while (0) 380 381 /* 382 * /dev/ppp device routines. 383 * The /dev/ppp device is used by pppd to control the ppp unit. 384 * It supports the read, write, ioctl and poll functions. 385 * Open instances of /dev/ppp can be in one of three states: 386 * unattached, attached to a ppp unit, or attached to a ppp channel. 387 */ 388 static int ppp_open(struct inode *inode, struct file *file) 389 { 390 /* 391 * This could (should?) be enforced by the permissions on /dev/ppp. 392 */ 393 if (!ns_capable(file->f_cred->user_ns, CAP_NET_ADMIN)) 394 return -EPERM; 395 return 0; 396 } 397 398 static int ppp_release(struct inode *unused, struct file *file) 399 { 400 struct ppp_file *pf = file->private_data; 401 struct ppp *ppp; 402 403 if (pf) { 404 file->private_data = NULL; 405 if (pf->kind == INTERFACE) { 406 ppp = PF_TO_PPP(pf); 407 rtnl_lock(); 408 if (file == ppp->owner) 409 unregister_netdevice(ppp->dev); 410 rtnl_unlock(); 411 } 412 if (refcount_dec_and_test(&pf->refcnt)) { 413 switch (pf->kind) { 414 case INTERFACE: 415 ppp_destroy_interface(PF_TO_PPP(pf)); 416 break; 417 case CHANNEL: 418 ppp_destroy_channel(PF_TO_CHANNEL(pf)); 419 break; 420 } 421 } 422 } 423 return 0; 424 } 425 426 static ssize_t ppp_read(struct file *file, char __user *buf, 427 size_t count, loff_t *ppos) 428 { 429 struct ppp_file *pf = file->private_data; 430 DECLARE_WAITQUEUE(wait, current); 431 ssize_t ret; 432 struct sk_buff *skb = NULL; 433 struct iovec iov; 434 struct iov_iter to; 435 436 ret = count; 437 438 if (!pf) 439 return -ENXIO; 440 add_wait_queue(&pf->rwait, &wait); 441 for (;;) { 442 set_current_state(TASK_INTERRUPTIBLE); 443 skb = skb_dequeue(&pf->rq); 444 if (skb) 445 break; 446 ret = 0; 447 if (pf->dead) 448 break; 449 if (pf->kind == INTERFACE) { 450 /* 451 * Return 0 (EOF) on an interface that has no 452 * channels connected, unless it is looping 453 * network traffic (demand mode). 454 */ 455 struct ppp *ppp = PF_TO_PPP(pf); 456 457 ppp_recv_lock(ppp); 458 if (ppp->n_channels == 0 && 459 (ppp->flags & SC_LOOP_TRAFFIC) == 0) { 460 ppp_recv_unlock(ppp); 461 break; 462 } 463 ppp_recv_unlock(ppp); 464 } 465 ret = -EAGAIN; 466 if (file->f_flags & O_NONBLOCK) 467 break; 468 ret = -ERESTARTSYS; 469 if (signal_pending(current)) 470 break; 471 schedule(); 472 } 473 set_current_state(TASK_RUNNING); 474 remove_wait_queue(&pf->rwait, &wait); 475 476 if (!skb) 477 goto out; 478 479 ret = -EOVERFLOW; 480 if (skb->len > count) 481 goto outf; 482 ret = -EFAULT; 483 iov.iov_base = buf; 484 iov.iov_len = count; 485 iov_iter_init(&to, READ, &iov, 1, count); 486 if (skb_copy_datagram_iter(skb, 0, &to, skb->len)) 487 goto outf; 488 ret = skb->len; 489 490 outf: 491 kfree_skb(skb); 492 out: 493 return ret; 494 } 495 496 static ssize_t ppp_write(struct file *file, const char __user *buf, 497 size_t count, loff_t *ppos) 498 { 499 struct ppp_file *pf = file->private_data; 500 struct sk_buff *skb; 501 ssize_t ret; 502 503 if (!pf) 504 return -ENXIO; 505 ret = -ENOMEM; 506 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL); 507 if (!skb) 508 goto out; 509 skb_reserve(skb, pf->hdrlen); 510 ret = -EFAULT; 511 if (copy_from_user(skb_put(skb, count), buf, count)) { 512 kfree_skb(skb); 513 goto out; 514 } 515 516 switch (pf->kind) { 517 case INTERFACE: 518 ppp_xmit_process(PF_TO_PPP(pf), skb); 519 break; 520 case CHANNEL: 521 skb_queue_tail(&pf->xq, skb); 522 ppp_channel_push(PF_TO_CHANNEL(pf)); 523 break; 524 } 525 526 ret = count; 527 528 out: 529 return ret; 530 } 531 532 /* No kernel lock - fine */ 533 static __poll_t ppp_poll(struct file *file, poll_table *wait) 534 { 535 struct ppp_file *pf = file->private_data; 536 __poll_t mask; 537 538 if (!pf) 539 return 0; 540 poll_wait(file, &pf->rwait, wait); 541 mask = EPOLLOUT | EPOLLWRNORM; 542 if (skb_peek(&pf->rq)) 543 mask |= EPOLLIN | EPOLLRDNORM; 544 if (pf->dead) 545 mask |= EPOLLHUP; 546 else if (pf->kind == INTERFACE) { 547 /* see comment in ppp_read */ 548 struct ppp *ppp = PF_TO_PPP(pf); 549 550 ppp_recv_lock(ppp); 551 if (ppp->n_channels == 0 && 552 (ppp->flags & SC_LOOP_TRAFFIC) == 0) 553 mask |= EPOLLIN | EPOLLRDNORM; 554 ppp_recv_unlock(ppp); 555 } 556 557 return mask; 558 } 559 560 #ifdef CONFIG_PPP_FILTER 561 static int get_filter(void __user *arg, struct sock_filter **p) 562 { 563 struct sock_fprog uprog; 564 struct sock_filter *code = NULL; 565 int len; 566 567 if (copy_from_user(&uprog, arg, sizeof(uprog))) 568 return -EFAULT; 569 570 if (!uprog.len) { 571 *p = NULL; 572 return 0; 573 } 574 575 len = uprog.len * sizeof(struct sock_filter); 576 code = memdup_user(uprog.filter, len); 577 if (IS_ERR(code)) 578 return PTR_ERR(code); 579 580 *p = code; 581 return uprog.len; 582 } 583 #endif /* CONFIG_PPP_FILTER */ 584 585 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 586 { 587 struct ppp_file *pf; 588 struct ppp *ppp; 589 int err = -EFAULT, val, val2, i; 590 struct ppp_idle idle; 591 struct npioctl npi; 592 int unit, cflags; 593 struct slcompress *vj; 594 void __user *argp = (void __user *)arg; 595 int __user *p = argp; 596 597 mutex_lock(&ppp_mutex); 598 599 pf = file->private_data; 600 if (!pf) { 601 err = ppp_unattached_ioctl(current->nsproxy->net_ns, 602 pf, file, cmd, arg); 603 goto out; 604 } 605 606 if (cmd == PPPIOCDETACH) { 607 /* 608 * 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 refcount_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 refcount_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 mutex_destroy(&pn->all_ppp_mutex); 963 idr_destroy(&pn->units_idr); 964 WARN_ON_ONCE(!list_empty(&pn->all_channels)); 965 WARN_ON_ONCE(!list_empty(&pn->new_channels)); 966 } 967 968 static struct pernet_operations ppp_net_ops = { 969 .init = ppp_init_net, 970 .exit = ppp_exit_net, 971 .id = &ppp_net_id, 972 .size = sizeof(struct ppp_net), 973 }; 974 975 static int ppp_unit_register(struct ppp *ppp, int unit, bool ifname_is_set) 976 { 977 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 978 int ret; 979 980 mutex_lock(&pn->all_ppp_mutex); 981 982 if (unit < 0) { 983 ret = unit_get(&pn->units_idr, ppp); 984 if (ret < 0) 985 goto err; 986 } else { 987 /* Caller asked for a specific unit number. Fail with -EEXIST 988 * if unavailable. For backward compatibility, return -EEXIST 989 * too if idr allocation fails; this makes pppd retry without 990 * requesting a specific unit number. 991 */ 992 if (unit_find(&pn->units_idr, unit)) { 993 ret = -EEXIST; 994 goto err; 995 } 996 ret = unit_set(&pn->units_idr, ppp, unit); 997 if (ret < 0) { 998 /* Rewrite error for backward compatibility */ 999 ret = -EEXIST; 1000 goto err; 1001 } 1002 } 1003 ppp->file.index = ret; 1004 1005 if (!ifname_is_set) 1006 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ppp->file.index); 1007 1008 mutex_unlock(&pn->all_ppp_mutex); 1009 1010 ret = register_netdevice(ppp->dev); 1011 if (ret < 0) 1012 goto err_unit; 1013 1014 atomic_inc(&ppp_unit_count); 1015 1016 return 0; 1017 1018 err_unit: 1019 mutex_lock(&pn->all_ppp_mutex); 1020 unit_put(&pn->units_idr, ppp->file.index); 1021 err: 1022 mutex_unlock(&pn->all_ppp_mutex); 1023 1024 return ret; 1025 } 1026 1027 static int ppp_dev_configure(struct net *src_net, struct net_device *dev, 1028 const struct ppp_config *conf) 1029 { 1030 struct ppp *ppp = netdev_priv(dev); 1031 int indx; 1032 int err; 1033 int cpu; 1034 1035 ppp->dev = dev; 1036 ppp->ppp_net = src_net; 1037 ppp->mru = PPP_MRU; 1038 ppp->owner = conf->file; 1039 1040 init_ppp_file(&ppp->file, INTERFACE); 1041 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */ 1042 1043 for (indx = 0; indx < NUM_NP; ++indx) 1044 ppp->npmode[indx] = NPMODE_PASS; 1045 INIT_LIST_HEAD(&ppp->channels); 1046 spin_lock_init(&ppp->rlock); 1047 spin_lock_init(&ppp->wlock); 1048 1049 ppp->xmit_recursion = alloc_percpu(int); 1050 if (!ppp->xmit_recursion) { 1051 err = -ENOMEM; 1052 goto err1; 1053 } 1054 for_each_possible_cpu(cpu) 1055 (*per_cpu_ptr(ppp->xmit_recursion, cpu)) = 0; 1056 1057 #ifdef CONFIG_PPP_MULTILINK 1058 ppp->minseq = -1; 1059 skb_queue_head_init(&ppp->mrq); 1060 #endif /* CONFIG_PPP_MULTILINK */ 1061 #ifdef CONFIG_PPP_FILTER 1062 ppp->pass_filter = NULL; 1063 ppp->active_filter = NULL; 1064 #endif /* CONFIG_PPP_FILTER */ 1065 1066 err = ppp_unit_register(ppp, conf->unit, conf->ifname_is_set); 1067 if (err < 0) 1068 goto err2; 1069 1070 conf->file->private_data = &ppp->file; 1071 1072 return 0; 1073 err2: 1074 free_percpu(ppp->xmit_recursion); 1075 err1: 1076 return err; 1077 } 1078 1079 static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = { 1080 [IFLA_PPP_DEV_FD] = { .type = NLA_S32 }, 1081 }; 1082 1083 static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[], 1084 struct netlink_ext_ack *extack) 1085 { 1086 if (!data) 1087 return -EINVAL; 1088 1089 if (!data[IFLA_PPP_DEV_FD]) 1090 return -EINVAL; 1091 if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0) 1092 return -EBADF; 1093 1094 return 0; 1095 } 1096 1097 static int ppp_nl_newlink(struct net *src_net, struct net_device *dev, 1098 struct nlattr *tb[], struct nlattr *data[], 1099 struct netlink_ext_ack *extack) 1100 { 1101 struct ppp_config conf = { 1102 .unit = -1, 1103 .ifname_is_set = true, 1104 }; 1105 struct file *file; 1106 int err; 1107 1108 file = fget(nla_get_s32(data[IFLA_PPP_DEV_FD])); 1109 if (!file) 1110 return -EBADF; 1111 1112 /* rtnl_lock is already held here, but ppp_create_interface() locks 1113 * ppp_mutex before holding rtnl_lock. Using mutex_trylock() avoids 1114 * possible deadlock due to lock order inversion, at the cost of 1115 * pushing the problem back to userspace. 1116 */ 1117 if (!mutex_trylock(&ppp_mutex)) { 1118 err = -EBUSY; 1119 goto out; 1120 } 1121 1122 if (file->f_op != &ppp_device_fops || file->private_data) { 1123 err = -EBADF; 1124 goto out_unlock; 1125 } 1126 1127 conf.file = file; 1128 1129 /* Don't use device name generated by the rtnetlink layer when ifname 1130 * isn't specified. Let ppp_dev_configure() set the device name using 1131 * the PPP unit identifer as suffix (i.e. ppp<unit_id>). This allows 1132 * userspace to infer the device name using to the PPPIOCGUNIT ioctl. 1133 */ 1134 if (!tb[IFLA_IFNAME]) 1135 conf.ifname_is_set = false; 1136 1137 err = ppp_dev_configure(src_net, dev, &conf); 1138 1139 out_unlock: 1140 mutex_unlock(&ppp_mutex); 1141 out: 1142 fput(file); 1143 1144 return err; 1145 } 1146 1147 static void ppp_nl_dellink(struct net_device *dev, struct list_head *head) 1148 { 1149 unregister_netdevice_queue(dev, head); 1150 } 1151 1152 static size_t ppp_nl_get_size(const struct net_device *dev) 1153 { 1154 return 0; 1155 } 1156 1157 static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev) 1158 { 1159 return 0; 1160 } 1161 1162 static struct net *ppp_nl_get_link_net(const struct net_device *dev) 1163 { 1164 struct ppp *ppp = netdev_priv(dev); 1165 1166 return ppp->ppp_net; 1167 } 1168 1169 static struct rtnl_link_ops ppp_link_ops __read_mostly = { 1170 .kind = "ppp", 1171 .maxtype = IFLA_PPP_MAX, 1172 .policy = ppp_nl_policy, 1173 .priv_size = sizeof(struct ppp), 1174 .setup = ppp_setup, 1175 .validate = ppp_nl_validate, 1176 .newlink = ppp_nl_newlink, 1177 .dellink = ppp_nl_dellink, 1178 .get_size = ppp_nl_get_size, 1179 .fill_info = ppp_nl_fill_info, 1180 .get_link_net = ppp_nl_get_link_net, 1181 }; 1182 1183 #define PPP_MAJOR 108 1184 1185 /* Called at boot time if ppp is compiled into the kernel, 1186 or at module load time (from init_module) if compiled as a module. */ 1187 static int __init ppp_init(void) 1188 { 1189 int err; 1190 1191 pr_info("PPP generic driver version " PPP_VERSION "\n"); 1192 1193 err = register_pernet_device(&ppp_net_ops); 1194 if (err) { 1195 pr_err("failed to register PPP pernet device (%d)\n", err); 1196 goto out; 1197 } 1198 1199 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops); 1200 if (err) { 1201 pr_err("failed to register PPP device (%d)\n", err); 1202 goto out_net; 1203 } 1204 1205 ppp_class = class_create(THIS_MODULE, "ppp"); 1206 if (IS_ERR(ppp_class)) { 1207 err = PTR_ERR(ppp_class); 1208 goto out_chrdev; 1209 } 1210 1211 err = rtnl_link_register(&ppp_link_ops); 1212 if (err) { 1213 pr_err("failed to register rtnetlink PPP handler\n"); 1214 goto out_class; 1215 } 1216 1217 /* not a big deal if we fail here :-) */ 1218 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp"); 1219 1220 return 0; 1221 1222 out_class: 1223 class_destroy(ppp_class); 1224 out_chrdev: 1225 unregister_chrdev(PPP_MAJOR, "ppp"); 1226 out_net: 1227 unregister_pernet_device(&ppp_net_ops); 1228 out: 1229 return err; 1230 } 1231 1232 /* 1233 * Network interface unit routines. 1234 */ 1235 static netdev_tx_t 1236 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev) 1237 { 1238 struct ppp *ppp = netdev_priv(dev); 1239 int npi, proto; 1240 unsigned char *pp; 1241 1242 npi = ethertype_to_npindex(ntohs(skb->protocol)); 1243 if (npi < 0) 1244 goto outf; 1245 1246 /* Drop, accept or reject the packet */ 1247 switch (ppp->npmode[npi]) { 1248 case NPMODE_PASS: 1249 break; 1250 case NPMODE_QUEUE: 1251 /* it would be nice to have a way to tell the network 1252 system to queue this one up for later. */ 1253 goto outf; 1254 case NPMODE_DROP: 1255 case NPMODE_ERROR: 1256 goto outf; 1257 } 1258 1259 /* Put the 2-byte PPP protocol number on the front, 1260 making sure there is room for the address and control fields. */ 1261 if (skb_cow_head(skb, PPP_HDRLEN)) 1262 goto outf; 1263 1264 pp = skb_push(skb, 2); 1265 proto = npindex_to_proto[npi]; 1266 put_unaligned_be16(proto, pp); 1267 1268 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev))); 1269 ppp_xmit_process(ppp, skb); 1270 1271 return NETDEV_TX_OK; 1272 1273 outf: 1274 kfree_skb(skb); 1275 ++dev->stats.tx_dropped; 1276 return NETDEV_TX_OK; 1277 } 1278 1279 static int 1280 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 1281 { 1282 struct ppp *ppp = netdev_priv(dev); 1283 int err = -EFAULT; 1284 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data; 1285 struct ppp_stats stats; 1286 struct ppp_comp_stats cstats; 1287 char *vers; 1288 1289 switch (cmd) { 1290 case SIOCGPPPSTATS: 1291 ppp_get_stats(ppp, &stats); 1292 if (copy_to_user(addr, &stats, sizeof(stats))) 1293 break; 1294 err = 0; 1295 break; 1296 1297 case SIOCGPPPCSTATS: 1298 memset(&cstats, 0, sizeof(cstats)); 1299 if (ppp->xc_state) 1300 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c); 1301 if (ppp->rc_state) 1302 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d); 1303 if (copy_to_user(addr, &cstats, sizeof(cstats))) 1304 break; 1305 err = 0; 1306 break; 1307 1308 case SIOCGPPPVER: 1309 vers = PPP_VERSION; 1310 if (copy_to_user(addr, vers, strlen(vers) + 1)) 1311 break; 1312 err = 0; 1313 break; 1314 1315 default: 1316 err = -EINVAL; 1317 } 1318 1319 return err; 1320 } 1321 1322 static void 1323 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64) 1324 { 1325 struct ppp *ppp = netdev_priv(dev); 1326 1327 ppp_recv_lock(ppp); 1328 stats64->rx_packets = ppp->stats64.rx_packets; 1329 stats64->rx_bytes = ppp->stats64.rx_bytes; 1330 ppp_recv_unlock(ppp); 1331 1332 ppp_xmit_lock(ppp); 1333 stats64->tx_packets = ppp->stats64.tx_packets; 1334 stats64->tx_bytes = ppp->stats64.tx_bytes; 1335 ppp_xmit_unlock(ppp); 1336 1337 stats64->rx_errors = dev->stats.rx_errors; 1338 stats64->tx_errors = dev->stats.tx_errors; 1339 stats64->rx_dropped = dev->stats.rx_dropped; 1340 stats64->tx_dropped = dev->stats.tx_dropped; 1341 stats64->rx_length_errors = dev->stats.rx_length_errors; 1342 } 1343 1344 static int ppp_dev_init(struct net_device *dev) 1345 { 1346 struct ppp *ppp; 1347 1348 netdev_lockdep_set_classes(dev); 1349 1350 ppp = netdev_priv(dev); 1351 /* Let the netdevice take a reference on the ppp file. This ensures 1352 * that ppp_destroy_interface() won't run before the device gets 1353 * unregistered. 1354 */ 1355 refcount_inc(&ppp->file.refcnt); 1356 1357 return 0; 1358 } 1359 1360 static void ppp_dev_uninit(struct net_device *dev) 1361 { 1362 struct ppp *ppp = netdev_priv(dev); 1363 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 1364 1365 ppp_lock(ppp); 1366 ppp->closing = 1; 1367 ppp_unlock(ppp); 1368 1369 mutex_lock(&pn->all_ppp_mutex); 1370 unit_put(&pn->units_idr, ppp->file.index); 1371 mutex_unlock(&pn->all_ppp_mutex); 1372 1373 ppp->owner = NULL; 1374 1375 ppp->file.dead = 1; 1376 wake_up_interruptible(&ppp->file.rwait); 1377 } 1378 1379 static void ppp_dev_priv_destructor(struct net_device *dev) 1380 { 1381 struct ppp *ppp; 1382 1383 ppp = netdev_priv(dev); 1384 if (refcount_dec_and_test(&ppp->file.refcnt)) 1385 ppp_destroy_interface(ppp); 1386 } 1387 1388 static const struct net_device_ops ppp_netdev_ops = { 1389 .ndo_init = ppp_dev_init, 1390 .ndo_uninit = ppp_dev_uninit, 1391 .ndo_start_xmit = ppp_start_xmit, 1392 .ndo_do_ioctl = ppp_net_ioctl, 1393 .ndo_get_stats64 = ppp_get_stats64, 1394 }; 1395 1396 static struct device_type ppp_type = { 1397 .name = "ppp", 1398 }; 1399 1400 static void ppp_setup(struct net_device *dev) 1401 { 1402 dev->netdev_ops = &ppp_netdev_ops; 1403 SET_NETDEV_DEVTYPE(dev, &ppp_type); 1404 1405 dev->features |= NETIF_F_LLTX; 1406 1407 dev->hard_header_len = PPP_HDRLEN; 1408 dev->mtu = PPP_MRU; 1409 dev->addr_len = 0; 1410 dev->tx_queue_len = 3; 1411 dev->type = ARPHRD_PPP; 1412 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 1413 dev->priv_destructor = ppp_dev_priv_destructor; 1414 netif_keep_dst(dev); 1415 } 1416 1417 /* 1418 * Transmit-side routines. 1419 */ 1420 1421 /* Called to do any work queued up on the transmit side that can now be done */ 1422 static void __ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb) 1423 { 1424 ppp_xmit_lock(ppp); 1425 if (!ppp->closing) { 1426 ppp_push(ppp); 1427 1428 if (skb) 1429 skb_queue_tail(&ppp->file.xq, skb); 1430 while (!ppp->xmit_pending && 1431 (skb = skb_dequeue(&ppp->file.xq))) 1432 ppp_send_frame(ppp, skb); 1433 /* If there's no work left to do, tell the core net 1434 code that we can accept some more. */ 1435 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq)) 1436 netif_wake_queue(ppp->dev); 1437 else 1438 netif_stop_queue(ppp->dev); 1439 } 1440 ppp_xmit_unlock(ppp); 1441 } 1442 1443 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb) 1444 { 1445 local_bh_disable(); 1446 1447 if (unlikely(*this_cpu_ptr(ppp->xmit_recursion))) 1448 goto err; 1449 1450 (*this_cpu_ptr(ppp->xmit_recursion))++; 1451 __ppp_xmit_process(ppp, skb); 1452 (*this_cpu_ptr(ppp->xmit_recursion))--; 1453 1454 local_bh_enable(); 1455 1456 return; 1457 1458 err: 1459 local_bh_enable(); 1460 1461 kfree_skb(skb); 1462 1463 if (net_ratelimit()) 1464 netdev_err(ppp->dev, "recursion detected\n"); 1465 } 1466 1467 static inline struct sk_buff * 1468 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) 1469 { 1470 struct sk_buff *new_skb; 1471 int len; 1472 int new_skb_size = ppp->dev->mtu + 1473 ppp->xcomp->comp_extra + ppp->dev->hard_header_len; 1474 int compressor_skb_size = ppp->dev->mtu + 1475 ppp->xcomp->comp_extra + PPP_HDRLEN; 1476 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC); 1477 if (!new_skb) { 1478 if (net_ratelimit()) 1479 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n"); 1480 return NULL; 1481 } 1482 if (ppp->dev->hard_header_len > PPP_HDRLEN) 1483 skb_reserve(new_skb, 1484 ppp->dev->hard_header_len - PPP_HDRLEN); 1485 1486 /* compressor still expects A/C bytes in hdr */ 1487 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, 1488 new_skb->data, skb->len + 2, 1489 compressor_skb_size); 1490 if (len > 0 && (ppp->flags & SC_CCP_UP)) { 1491 consume_skb(skb); 1492 skb = new_skb; 1493 skb_put(skb, len); 1494 skb_pull(skb, 2); /* pull off A/C bytes */ 1495 } else if (len == 0) { 1496 /* didn't compress, or CCP not up yet */ 1497 consume_skb(new_skb); 1498 new_skb = skb; 1499 } else { 1500 /* 1501 * (len < 0) 1502 * MPPE requires that we do not send unencrypted 1503 * frames. The compressor will return -1 if we 1504 * should drop the frame. We cannot simply test 1505 * the compress_proto because MPPE and MPPC share 1506 * the same number. 1507 */ 1508 if (net_ratelimit()) 1509 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n"); 1510 kfree_skb(skb); 1511 consume_skb(new_skb); 1512 new_skb = NULL; 1513 } 1514 return new_skb; 1515 } 1516 1517 /* 1518 * Compress and send a frame. 1519 * The caller should have locked the xmit path, 1520 * and xmit_pending should be 0. 1521 */ 1522 static void 1523 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) 1524 { 1525 int proto = PPP_PROTO(skb); 1526 struct sk_buff *new_skb; 1527 int len; 1528 unsigned char *cp; 1529 1530 if (proto < 0x8000) { 1531 #ifdef CONFIG_PPP_FILTER 1532 /* check if we should pass this packet */ 1533 /* the filter instructions are constructed assuming 1534 a four-byte PPP header on each packet */ 1535 *(u8 *)skb_push(skb, 2) = 1; 1536 if (ppp->pass_filter && 1537 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 1538 if (ppp->debug & 1) 1539 netdev_printk(KERN_DEBUG, ppp->dev, 1540 "PPP: outbound frame " 1541 "not passed\n"); 1542 kfree_skb(skb); 1543 return; 1544 } 1545 /* if this packet passes the active filter, record the time */ 1546 if (!(ppp->active_filter && 1547 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 1548 ppp->last_xmit = jiffies; 1549 skb_pull(skb, 2); 1550 #else 1551 /* for data packets, record the time */ 1552 ppp->last_xmit = jiffies; 1553 #endif /* CONFIG_PPP_FILTER */ 1554 } 1555 1556 ++ppp->stats64.tx_packets; 1557 ppp->stats64.tx_bytes += skb->len - 2; 1558 1559 switch (proto) { 1560 case PPP_IP: 1561 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0) 1562 break; 1563 /* try to do VJ TCP header compression */ 1564 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2, 1565 GFP_ATOMIC); 1566 if (!new_skb) { 1567 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n"); 1568 goto drop; 1569 } 1570 skb_reserve(new_skb, ppp->dev->hard_header_len - 2); 1571 cp = skb->data + 2; 1572 len = slhc_compress(ppp->vj, cp, skb->len - 2, 1573 new_skb->data + 2, &cp, 1574 !(ppp->flags & SC_NO_TCP_CCID)); 1575 if (cp == skb->data + 2) { 1576 /* didn't compress */ 1577 consume_skb(new_skb); 1578 } else { 1579 if (cp[0] & SL_TYPE_COMPRESSED_TCP) { 1580 proto = PPP_VJC_COMP; 1581 cp[0] &= ~SL_TYPE_COMPRESSED_TCP; 1582 } else { 1583 proto = PPP_VJC_UNCOMP; 1584 cp[0] = skb->data[2]; 1585 } 1586 consume_skb(skb); 1587 skb = new_skb; 1588 cp = skb_put(skb, len + 2); 1589 cp[0] = 0; 1590 cp[1] = proto; 1591 } 1592 break; 1593 1594 case PPP_CCP: 1595 /* peek at outbound CCP frames */ 1596 ppp_ccp_peek(ppp, skb, 0); 1597 break; 1598 } 1599 1600 /* try to do packet compression */ 1601 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state && 1602 proto != PPP_LCP && proto != PPP_CCP) { 1603 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) { 1604 if (net_ratelimit()) 1605 netdev_err(ppp->dev, 1606 "ppp: compression required but " 1607 "down - pkt dropped.\n"); 1608 goto drop; 1609 } 1610 skb = pad_compress_skb(ppp, skb); 1611 if (!skb) 1612 goto drop; 1613 } 1614 1615 /* 1616 * If we are waiting for traffic (demand dialling), 1617 * queue it up for pppd to receive. 1618 */ 1619 if (ppp->flags & SC_LOOP_TRAFFIC) { 1620 if (ppp->file.rq.qlen > PPP_MAX_RQLEN) 1621 goto drop; 1622 skb_queue_tail(&ppp->file.rq, skb); 1623 wake_up_interruptible(&ppp->file.rwait); 1624 return; 1625 } 1626 1627 ppp->xmit_pending = skb; 1628 ppp_push(ppp); 1629 return; 1630 1631 drop: 1632 kfree_skb(skb); 1633 ++ppp->dev->stats.tx_errors; 1634 } 1635 1636 /* 1637 * Try to send the frame in xmit_pending. 1638 * The caller should have the xmit path locked. 1639 */ 1640 static void 1641 ppp_push(struct ppp *ppp) 1642 { 1643 struct list_head *list; 1644 struct channel *pch; 1645 struct sk_buff *skb = ppp->xmit_pending; 1646 1647 if (!skb) 1648 return; 1649 1650 list = &ppp->channels; 1651 if (list_empty(list)) { 1652 /* nowhere to send the packet, just drop it */ 1653 ppp->xmit_pending = NULL; 1654 kfree_skb(skb); 1655 return; 1656 } 1657 1658 if ((ppp->flags & SC_MULTILINK) == 0) { 1659 /* not doing multilink: send it down the first channel */ 1660 list = list->next; 1661 pch = list_entry(list, struct channel, clist); 1662 1663 spin_lock(&pch->downl); 1664 if (pch->chan) { 1665 if (pch->chan->ops->start_xmit(pch->chan, skb)) 1666 ppp->xmit_pending = NULL; 1667 } else { 1668 /* channel got unregistered */ 1669 kfree_skb(skb); 1670 ppp->xmit_pending = NULL; 1671 } 1672 spin_unlock(&pch->downl); 1673 return; 1674 } 1675 1676 #ifdef CONFIG_PPP_MULTILINK 1677 /* Multilink: fragment the packet over as many links 1678 as can take the packet at the moment. */ 1679 if (!ppp_mp_explode(ppp, skb)) 1680 return; 1681 #endif /* CONFIG_PPP_MULTILINK */ 1682 1683 ppp->xmit_pending = NULL; 1684 kfree_skb(skb); 1685 } 1686 1687 #ifdef CONFIG_PPP_MULTILINK 1688 static bool mp_protocol_compress __read_mostly = true; 1689 module_param(mp_protocol_compress, bool, 0644); 1690 MODULE_PARM_DESC(mp_protocol_compress, 1691 "compress protocol id in multilink fragments"); 1692 1693 /* 1694 * Divide a packet to be transmitted into fragments and 1695 * send them out the individual links. 1696 */ 1697 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb) 1698 { 1699 int len, totlen; 1700 int i, bits, hdrlen, mtu; 1701 int flen; 1702 int navail, nfree, nzero; 1703 int nbigger; 1704 int totspeed; 1705 int totfree; 1706 unsigned char *p, *q; 1707 struct list_head *list; 1708 struct channel *pch; 1709 struct sk_buff *frag; 1710 struct ppp_channel *chan; 1711 1712 totspeed = 0; /*total bitrate of the bundle*/ 1713 nfree = 0; /* # channels which have no packet already queued */ 1714 navail = 0; /* total # of usable channels (not deregistered) */ 1715 nzero = 0; /* number of channels with zero speed associated*/ 1716 totfree = 0; /*total # of channels available and 1717 *having no queued packets before 1718 *starting the fragmentation*/ 1719 1720 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1721 i = 0; 1722 list_for_each_entry(pch, &ppp->channels, clist) { 1723 if (pch->chan) { 1724 pch->avail = 1; 1725 navail++; 1726 pch->speed = pch->chan->speed; 1727 } else { 1728 pch->avail = 0; 1729 } 1730 if (pch->avail) { 1731 if (skb_queue_empty(&pch->file.xq) || 1732 !pch->had_frag) { 1733 if (pch->speed == 0) 1734 nzero++; 1735 else 1736 totspeed += pch->speed; 1737 1738 pch->avail = 2; 1739 ++nfree; 1740 ++totfree; 1741 } 1742 if (!pch->had_frag && i < ppp->nxchan) 1743 ppp->nxchan = i; 1744 } 1745 ++i; 1746 } 1747 /* 1748 * Don't start sending this packet unless at least half of 1749 * the channels are free. This gives much better TCP 1750 * performance if we have a lot of channels. 1751 */ 1752 if (nfree == 0 || nfree < navail / 2) 1753 return 0; /* can't take now, leave it in xmit_pending */ 1754 1755 /* Do protocol field compression */ 1756 p = skb->data; 1757 len = skb->len; 1758 if (*p == 0 && mp_protocol_compress) { 1759 ++p; 1760 --len; 1761 } 1762 1763 totlen = len; 1764 nbigger = len % nfree; 1765 1766 /* skip to the channel after the one we last used 1767 and start at that one */ 1768 list = &ppp->channels; 1769 for (i = 0; i < ppp->nxchan; ++i) { 1770 list = list->next; 1771 if (list == &ppp->channels) { 1772 i = 0; 1773 break; 1774 } 1775 } 1776 1777 /* create a fragment for each channel */ 1778 bits = B; 1779 while (len > 0) { 1780 list = list->next; 1781 if (list == &ppp->channels) { 1782 i = 0; 1783 continue; 1784 } 1785 pch = list_entry(list, struct channel, clist); 1786 ++i; 1787 if (!pch->avail) 1788 continue; 1789 1790 /* 1791 * Skip this channel if it has a fragment pending already and 1792 * we haven't given a fragment to all of the free channels. 1793 */ 1794 if (pch->avail == 1) { 1795 if (nfree > 0) 1796 continue; 1797 } else { 1798 pch->avail = 1; 1799 } 1800 1801 /* check the channel's mtu and whether it is still attached. */ 1802 spin_lock(&pch->downl); 1803 if (pch->chan == NULL) { 1804 /* can't use this channel, it's being deregistered */ 1805 if (pch->speed == 0) 1806 nzero--; 1807 else 1808 totspeed -= pch->speed; 1809 1810 spin_unlock(&pch->downl); 1811 pch->avail = 0; 1812 totlen = len; 1813 totfree--; 1814 nfree--; 1815 if (--navail == 0) 1816 break; 1817 continue; 1818 } 1819 1820 /* 1821 *if the channel speed is not set divide 1822 *the packet evenly among the free channels; 1823 *otherwise divide it according to the speed 1824 *of the channel we are going to transmit on 1825 */ 1826 flen = len; 1827 if (nfree > 0) { 1828 if (pch->speed == 0) { 1829 flen = len/nfree; 1830 if (nbigger > 0) { 1831 flen++; 1832 nbigger--; 1833 } 1834 } else { 1835 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) / 1836 ((totspeed*totfree)/pch->speed)) - hdrlen; 1837 if (nbigger > 0) { 1838 flen += ((totfree - nzero)*pch->speed)/totspeed; 1839 nbigger -= ((totfree - nzero)*pch->speed)/ 1840 totspeed; 1841 } 1842 } 1843 nfree--; 1844 } 1845 1846 /* 1847 *check if we are on the last channel or 1848 *we exceded the length of the data to 1849 *fragment 1850 */ 1851 if ((nfree <= 0) || (flen > len)) 1852 flen = len; 1853 /* 1854 *it is not worth to tx on slow channels: 1855 *in that case from the resulting flen according to the 1856 *above formula will be equal or less than zero. 1857 *Skip the channel in this case 1858 */ 1859 if (flen <= 0) { 1860 pch->avail = 2; 1861 spin_unlock(&pch->downl); 1862 continue; 1863 } 1864 1865 /* 1866 * hdrlen includes the 2-byte PPP protocol field, but the 1867 * MTU counts only the payload excluding the protocol field. 1868 * (RFC1661 Section 2) 1869 */ 1870 mtu = pch->chan->mtu - (hdrlen - 2); 1871 if (mtu < 4) 1872 mtu = 4; 1873 if (flen > mtu) 1874 flen = mtu; 1875 if (flen == len) 1876 bits |= E; 1877 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC); 1878 if (!frag) 1879 goto noskb; 1880 q = skb_put(frag, flen + hdrlen); 1881 1882 /* make the MP header */ 1883 put_unaligned_be16(PPP_MP, q); 1884 if (ppp->flags & SC_MP_XSHORTSEQ) { 1885 q[2] = bits + ((ppp->nxseq >> 8) & 0xf); 1886 q[3] = ppp->nxseq; 1887 } else { 1888 q[2] = bits; 1889 q[3] = ppp->nxseq >> 16; 1890 q[4] = ppp->nxseq >> 8; 1891 q[5] = ppp->nxseq; 1892 } 1893 1894 memcpy(q + hdrlen, p, flen); 1895 1896 /* try to send it down the channel */ 1897 chan = pch->chan; 1898 if (!skb_queue_empty(&pch->file.xq) || 1899 !chan->ops->start_xmit(chan, frag)) 1900 skb_queue_tail(&pch->file.xq, frag); 1901 pch->had_frag = 1; 1902 p += flen; 1903 len -= flen; 1904 ++ppp->nxseq; 1905 bits = 0; 1906 spin_unlock(&pch->downl); 1907 } 1908 ppp->nxchan = i; 1909 1910 return 1; 1911 1912 noskb: 1913 spin_unlock(&pch->downl); 1914 if (ppp->debug & 1) 1915 netdev_err(ppp->dev, "PPP: no memory (fragment)\n"); 1916 ++ppp->dev->stats.tx_errors; 1917 ++ppp->nxseq; 1918 return 1; /* abandon the frame */ 1919 } 1920 #endif /* CONFIG_PPP_MULTILINK */ 1921 1922 /* Try to send data out on a channel */ 1923 static void __ppp_channel_push(struct channel *pch) 1924 { 1925 struct sk_buff *skb; 1926 struct ppp *ppp; 1927 1928 spin_lock(&pch->downl); 1929 if (pch->chan) { 1930 while (!skb_queue_empty(&pch->file.xq)) { 1931 skb = skb_dequeue(&pch->file.xq); 1932 if (!pch->chan->ops->start_xmit(pch->chan, skb)) { 1933 /* put the packet back and try again later */ 1934 skb_queue_head(&pch->file.xq, skb); 1935 break; 1936 } 1937 } 1938 } else { 1939 /* channel got deregistered */ 1940 skb_queue_purge(&pch->file.xq); 1941 } 1942 spin_unlock(&pch->downl); 1943 /* see if there is anything from the attached unit to be sent */ 1944 if (skb_queue_empty(&pch->file.xq)) { 1945 ppp = pch->ppp; 1946 if (ppp) 1947 __ppp_xmit_process(ppp, NULL); 1948 } 1949 } 1950 1951 static void ppp_channel_push(struct channel *pch) 1952 { 1953 read_lock_bh(&pch->upl); 1954 if (pch->ppp) { 1955 (*this_cpu_ptr(pch->ppp->xmit_recursion))++; 1956 __ppp_channel_push(pch); 1957 (*this_cpu_ptr(pch->ppp->xmit_recursion))--; 1958 } else { 1959 __ppp_channel_push(pch); 1960 } 1961 read_unlock_bh(&pch->upl); 1962 } 1963 1964 /* 1965 * Receive-side routines. 1966 */ 1967 1968 struct ppp_mp_skb_parm { 1969 u32 sequence; 1970 u8 BEbits; 1971 }; 1972 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb)) 1973 1974 static inline void 1975 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1976 { 1977 ppp_recv_lock(ppp); 1978 if (!ppp->closing) 1979 ppp_receive_frame(ppp, skb, pch); 1980 else 1981 kfree_skb(skb); 1982 ppp_recv_unlock(ppp); 1983 } 1984 1985 void 1986 ppp_input(struct ppp_channel *chan, struct sk_buff *skb) 1987 { 1988 struct channel *pch = chan->ppp; 1989 int proto; 1990 1991 if (!pch) { 1992 kfree_skb(skb); 1993 return; 1994 } 1995 1996 read_lock_bh(&pch->upl); 1997 if (!pskb_may_pull(skb, 2)) { 1998 kfree_skb(skb); 1999 if (pch->ppp) { 2000 ++pch->ppp->dev->stats.rx_length_errors; 2001 ppp_receive_error(pch->ppp); 2002 } 2003 goto done; 2004 } 2005 2006 proto = PPP_PROTO(skb); 2007 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) { 2008 /* put it on the channel queue */ 2009 skb_queue_tail(&pch->file.rq, skb); 2010 /* drop old frames if queue too long */ 2011 while (pch->file.rq.qlen > PPP_MAX_RQLEN && 2012 (skb = skb_dequeue(&pch->file.rq))) 2013 kfree_skb(skb); 2014 wake_up_interruptible(&pch->file.rwait); 2015 } else { 2016 ppp_do_recv(pch->ppp, skb, pch); 2017 } 2018 2019 done: 2020 read_unlock_bh(&pch->upl); 2021 } 2022 2023 /* Put a 0-length skb in the receive queue as an error indication */ 2024 void 2025 ppp_input_error(struct ppp_channel *chan, int code) 2026 { 2027 struct channel *pch = chan->ppp; 2028 struct sk_buff *skb; 2029 2030 if (!pch) 2031 return; 2032 2033 read_lock_bh(&pch->upl); 2034 if (pch->ppp) { 2035 skb = alloc_skb(0, GFP_ATOMIC); 2036 if (skb) { 2037 skb->len = 0; /* probably unnecessary */ 2038 skb->cb[0] = code; 2039 ppp_do_recv(pch->ppp, skb, pch); 2040 } 2041 } 2042 read_unlock_bh(&pch->upl); 2043 } 2044 2045 /* 2046 * We come in here to process a received frame. 2047 * The receive side of the ppp unit is locked. 2048 */ 2049 static void 2050 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2051 { 2052 /* note: a 0-length skb is used as an error indication */ 2053 if (skb->len > 0) { 2054 skb_checksum_complete_unset(skb); 2055 #ifdef CONFIG_PPP_MULTILINK 2056 /* XXX do channel-level decompression here */ 2057 if (PPP_PROTO(skb) == PPP_MP) 2058 ppp_receive_mp_frame(ppp, skb, pch); 2059 else 2060 #endif /* CONFIG_PPP_MULTILINK */ 2061 ppp_receive_nonmp_frame(ppp, skb); 2062 } else { 2063 kfree_skb(skb); 2064 ppp_receive_error(ppp); 2065 } 2066 } 2067 2068 static void 2069 ppp_receive_error(struct ppp *ppp) 2070 { 2071 ++ppp->dev->stats.rx_errors; 2072 if (ppp->vj) 2073 slhc_toss(ppp->vj); 2074 } 2075 2076 static void 2077 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) 2078 { 2079 struct sk_buff *ns; 2080 int proto, len, npi; 2081 2082 /* 2083 * Decompress the frame, if compressed. 2084 * Note that some decompressors need to see uncompressed frames 2085 * that come in as well as compressed frames. 2086 */ 2087 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) && 2088 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0) 2089 skb = ppp_decompress_frame(ppp, skb); 2090 2091 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR) 2092 goto err; 2093 2094 proto = PPP_PROTO(skb); 2095 switch (proto) { 2096 case PPP_VJC_COMP: 2097 /* decompress VJ compressed packets */ 2098 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 2099 goto err; 2100 2101 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) { 2102 /* copy to a new sk_buff with more tailroom */ 2103 ns = dev_alloc_skb(skb->len + 128); 2104 if (!ns) { 2105 netdev_err(ppp->dev, "PPP: no memory " 2106 "(VJ decomp)\n"); 2107 goto err; 2108 } 2109 skb_reserve(ns, 2); 2110 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len); 2111 consume_skb(skb); 2112 skb = ns; 2113 } 2114 else 2115 skb->ip_summed = CHECKSUM_NONE; 2116 2117 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2); 2118 if (len <= 0) { 2119 netdev_printk(KERN_DEBUG, ppp->dev, 2120 "PPP: VJ decompression error\n"); 2121 goto err; 2122 } 2123 len += 2; 2124 if (len > skb->len) 2125 skb_put(skb, len - skb->len); 2126 else if (len < skb->len) 2127 skb_trim(skb, len); 2128 proto = PPP_IP; 2129 break; 2130 2131 case PPP_VJC_UNCOMP: 2132 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 2133 goto err; 2134 2135 /* Until we fix the decompressor need to make sure 2136 * data portion is linear. 2137 */ 2138 if (!pskb_may_pull(skb, skb->len)) 2139 goto err; 2140 2141 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) { 2142 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n"); 2143 goto err; 2144 } 2145 proto = PPP_IP; 2146 break; 2147 2148 case PPP_CCP: 2149 ppp_ccp_peek(ppp, skb, 1); 2150 break; 2151 } 2152 2153 ++ppp->stats64.rx_packets; 2154 ppp->stats64.rx_bytes += skb->len - 2; 2155 2156 npi = proto_to_npindex(proto); 2157 if (npi < 0) { 2158 /* control or unknown frame - pass it to pppd */ 2159 skb_queue_tail(&ppp->file.rq, skb); 2160 /* limit queue length by dropping old frames */ 2161 while (ppp->file.rq.qlen > PPP_MAX_RQLEN && 2162 (skb = skb_dequeue(&ppp->file.rq))) 2163 kfree_skb(skb); 2164 /* wake up any process polling or blocking on read */ 2165 wake_up_interruptible(&ppp->file.rwait); 2166 2167 } else { 2168 /* network protocol frame - give it to the kernel */ 2169 2170 #ifdef CONFIG_PPP_FILTER 2171 /* check if the packet passes the pass and active filters */ 2172 /* the filter instructions are constructed assuming 2173 a four-byte PPP header on each packet */ 2174 if (ppp->pass_filter || ppp->active_filter) { 2175 if (skb_unclone(skb, GFP_ATOMIC)) 2176 goto err; 2177 2178 *(u8 *)skb_push(skb, 2) = 0; 2179 if (ppp->pass_filter && 2180 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 2181 if (ppp->debug & 1) 2182 netdev_printk(KERN_DEBUG, ppp->dev, 2183 "PPP: inbound frame " 2184 "not passed\n"); 2185 kfree_skb(skb); 2186 return; 2187 } 2188 if (!(ppp->active_filter && 2189 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 2190 ppp->last_recv = jiffies; 2191 __skb_pull(skb, 2); 2192 } else 2193 #endif /* CONFIG_PPP_FILTER */ 2194 ppp->last_recv = jiffies; 2195 2196 if ((ppp->dev->flags & IFF_UP) == 0 || 2197 ppp->npmode[npi] != NPMODE_PASS) { 2198 kfree_skb(skb); 2199 } else { 2200 /* chop off protocol */ 2201 skb_pull_rcsum(skb, 2); 2202 skb->dev = ppp->dev; 2203 skb->protocol = htons(npindex_to_ethertype[npi]); 2204 skb_reset_mac_header(skb); 2205 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, 2206 dev_net(ppp->dev))); 2207 netif_rx(skb); 2208 } 2209 } 2210 return; 2211 2212 err: 2213 kfree_skb(skb); 2214 ppp_receive_error(ppp); 2215 } 2216 2217 static struct sk_buff * 2218 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb) 2219 { 2220 int proto = PPP_PROTO(skb); 2221 struct sk_buff *ns; 2222 int len; 2223 2224 /* Until we fix all the decompressor's need to make sure 2225 * data portion is linear. 2226 */ 2227 if (!pskb_may_pull(skb, skb->len)) 2228 goto err; 2229 2230 if (proto == PPP_COMP) { 2231 int obuff_size; 2232 2233 switch(ppp->rcomp->compress_proto) { 2234 case CI_MPPE: 2235 obuff_size = ppp->mru + PPP_HDRLEN + 1; 2236 break; 2237 default: 2238 obuff_size = ppp->mru + PPP_HDRLEN; 2239 break; 2240 } 2241 2242 ns = dev_alloc_skb(obuff_size); 2243 if (!ns) { 2244 netdev_err(ppp->dev, "ppp_decompress_frame: " 2245 "no memory\n"); 2246 goto err; 2247 } 2248 /* the decompressor still expects the A/C bytes in the hdr */ 2249 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2, 2250 skb->len + 2, ns->data, obuff_size); 2251 if (len < 0) { 2252 /* Pass the compressed frame to pppd as an 2253 error indication. */ 2254 if (len == DECOMP_FATALERROR) 2255 ppp->rstate |= SC_DC_FERROR; 2256 kfree_skb(ns); 2257 goto err; 2258 } 2259 2260 consume_skb(skb); 2261 skb = ns; 2262 skb_put(skb, len); 2263 skb_pull(skb, 2); /* pull off the A/C bytes */ 2264 2265 } else { 2266 /* Uncompressed frame - pass to decompressor so it 2267 can update its dictionary if necessary. */ 2268 if (ppp->rcomp->incomp) 2269 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2, 2270 skb->len + 2); 2271 } 2272 2273 return skb; 2274 2275 err: 2276 ppp->rstate |= SC_DC_ERROR; 2277 ppp_receive_error(ppp); 2278 return skb; 2279 } 2280 2281 #ifdef CONFIG_PPP_MULTILINK 2282 /* 2283 * Receive a multilink frame. 2284 * We put it on the reconstruction queue and then pull off 2285 * as many completed frames as we can. 2286 */ 2287 static void 2288 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2289 { 2290 u32 mask, seq; 2291 struct channel *ch; 2292 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 2293 2294 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0) 2295 goto err; /* no good, throw it away */ 2296 2297 /* Decode sequence number and begin/end bits */ 2298 if (ppp->flags & SC_MP_SHORTSEQ) { 2299 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3]; 2300 mask = 0xfff; 2301 } else { 2302 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5]; 2303 mask = 0xffffff; 2304 } 2305 PPP_MP_CB(skb)->BEbits = skb->data[2]; 2306 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */ 2307 2308 /* 2309 * Do protocol ID decompression on the first fragment of each packet. 2310 */ 2311 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1)) 2312 *(u8 *)skb_push(skb, 1) = 0; 2313 2314 /* 2315 * Expand sequence number to 32 bits, making it as close 2316 * as possible to ppp->minseq. 2317 */ 2318 seq |= ppp->minseq & ~mask; 2319 if ((int)(ppp->minseq - seq) > (int)(mask >> 1)) 2320 seq += mask + 1; 2321 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1)) 2322 seq -= mask + 1; /* should never happen */ 2323 PPP_MP_CB(skb)->sequence = seq; 2324 pch->lastseq = seq; 2325 2326 /* 2327 * If this packet comes before the next one we were expecting, 2328 * drop it. 2329 */ 2330 if (seq_before(seq, ppp->nextseq)) { 2331 kfree_skb(skb); 2332 ++ppp->dev->stats.rx_dropped; 2333 ppp_receive_error(ppp); 2334 return; 2335 } 2336 2337 /* 2338 * Reevaluate minseq, the minimum over all channels of the 2339 * last sequence number received on each channel. Because of 2340 * the increasing sequence number rule, we know that any fragment 2341 * before `minseq' which hasn't arrived is never going to arrive. 2342 * The list of channels can't change because we have the receive 2343 * side of the ppp unit locked. 2344 */ 2345 list_for_each_entry(ch, &ppp->channels, clist) { 2346 if (seq_before(ch->lastseq, seq)) 2347 seq = ch->lastseq; 2348 } 2349 if (seq_before(ppp->minseq, seq)) 2350 ppp->minseq = seq; 2351 2352 /* Put the fragment on the reconstruction queue */ 2353 ppp_mp_insert(ppp, skb); 2354 2355 /* If the queue is getting long, don't wait any longer for packets 2356 before the start of the queue. */ 2357 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) { 2358 struct sk_buff *mskb = skb_peek(&ppp->mrq); 2359 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence)) 2360 ppp->minseq = PPP_MP_CB(mskb)->sequence; 2361 } 2362 2363 /* Pull completed packets off the queue and receive them. */ 2364 while ((skb = ppp_mp_reconstruct(ppp))) { 2365 if (pskb_may_pull(skb, 2)) 2366 ppp_receive_nonmp_frame(ppp, skb); 2367 else { 2368 ++ppp->dev->stats.rx_length_errors; 2369 kfree_skb(skb); 2370 ppp_receive_error(ppp); 2371 } 2372 } 2373 2374 return; 2375 2376 err: 2377 kfree_skb(skb); 2378 ppp_receive_error(ppp); 2379 } 2380 2381 /* 2382 * Insert a fragment on the MP reconstruction queue. 2383 * The queue is ordered by increasing sequence number. 2384 */ 2385 static void 2386 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb) 2387 { 2388 struct sk_buff *p; 2389 struct sk_buff_head *list = &ppp->mrq; 2390 u32 seq = PPP_MP_CB(skb)->sequence; 2391 2392 /* N.B. we don't need to lock the list lock because we have the 2393 ppp unit receive-side lock. */ 2394 skb_queue_walk(list, p) { 2395 if (seq_before(seq, PPP_MP_CB(p)->sequence)) 2396 break; 2397 } 2398 __skb_queue_before(list, p, skb); 2399 } 2400 2401 /* 2402 * Reconstruct a packet from the MP fragment queue. 2403 * We go through increasing sequence numbers until we find a 2404 * complete packet, or we get to the sequence number for a fragment 2405 * which hasn't arrived but might still do so. 2406 */ 2407 static struct sk_buff * 2408 ppp_mp_reconstruct(struct ppp *ppp) 2409 { 2410 u32 seq = ppp->nextseq; 2411 u32 minseq = ppp->minseq; 2412 struct sk_buff_head *list = &ppp->mrq; 2413 struct sk_buff *p, *tmp; 2414 struct sk_buff *head, *tail; 2415 struct sk_buff *skb = NULL; 2416 int lost = 0, len = 0; 2417 2418 if (ppp->mrru == 0) /* do nothing until mrru is set */ 2419 return NULL; 2420 head = list->next; 2421 tail = NULL; 2422 skb_queue_walk_safe(list, p, tmp) { 2423 again: 2424 if (seq_before(PPP_MP_CB(p)->sequence, seq)) { 2425 /* this can't happen, anyway ignore the skb */ 2426 netdev_err(ppp->dev, "ppp_mp_reconstruct bad " 2427 "seq %u < %u\n", 2428 PPP_MP_CB(p)->sequence, seq); 2429 __skb_unlink(p, list); 2430 kfree_skb(p); 2431 continue; 2432 } 2433 if (PPP_MP_CB(p)->sequence != seq) { 2434 u32 oldseq; 2435 /* Fragment `seq' is missing. If it is after 2436 minseq, it might arrive later, so stop here. */ 2437 if (seq_after(seq, minseq)) 2438 break; 2439 /* Fragment `seq' is lost, keep going. */ 2440 lost = 1; 2441 oldseq = seq; 2442 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)? 2443 minseq + 1: PPP_MP_CB(p)->sequence; 2444 2445 if (ppp->debug & 1) 2446 netdev_printk(KERN_DEBUG, ppp->dev, 2447 "lost frag %u..%u\n", 2448 oldseq, seq-1); 2449 2450 goto again; 2451 } 2452 2453 /* 2454 * At this point we know that all the fragments from 2455 * ppp->nextseq to seq are either present or lost. 2456 * Also, there are no complete packets in the queue 2457 * that have no missing fragments and end before this 2458 * fragment. 2459 */ 2460 2461 /* B bit set indicates this fragment starts a packet */ 2462 if (PPP_MP_CB(p)->BEbits & B) { 2463 head = p; 2464 lost = 0; 2465 len = 0; 2466 } 2467 2468 len += p->len; 2469 2470 /* Got a complete packet yet? */ 2471 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) && 2472 (PPP_MP_CB(head)->BEbits & B)) { 2473 if (len > ppp->mrru + 2) { 2474 ++ppp->dev->stats.rx_length_errors; 2475 netdev_printk(KERN_DEBUG, ppp->dev, 2476 "PPP: reconstructed packet" 2477 " is too long (%d)\n", len); 2478 } else { 2479 tail = p; 2480 break; 2481 } 2482 ppp->nextseq = seq + 1; 2483 } 2484 2485 /* 2486 * If this is the ending fragment of a packet, 2487 * and we haven't found a complete valid packet yet, 2488 * we can discard up to and including this fragment. 2489 */ 2490 if (PPP_MP_CB(p)->BEbits & E) { 2491 struct sk_buff *tmp2; 2492 2493 skb_queue_reverse_walk_from_safe(list, p, tmp2) { 2494 if (ppp->debug & 1) 2495 netdev_printk(KERN_DEBUG, ppp->dev, 2496 "discarding frag %u\n", 2497 PPP_MP_CB(p)->sequence); 2498 __skb_unlink(p, list); 2499 kfree_skb(p); 2500 } 2501 head = skb_peek(list); 2502 if (!head) 2503 break; 2504 } 2505 ++seq; 2506 } 2507 2508 /* If we have a complete packet, copy it all into one skb. */ 2509 if (tail != NULL) { 2510 /* If we have discarded any fragments, 2511 signal a receive error. */ 2512 if (PPP_MP_CB(head)->sequence != ppp->nextseq) { 2513 skb_queue_walk_safe(list, p, tmp) { 2514 if (p == head) 2515 break; 2516 if (ppp->debug & 1) 2517 netdev_printk(KERN_DEBUG, ppp->dev, 2518 "discarding frag %u\n", 2519 PPP_MP_CB(p)->sequence); 2520 __skb_unlink(p, list); 2521 kfree_skb(p); 2522 } 2523 2524 if (ppp->debug & 1) 2525 netdev_printk(KERN_DEBUG, ppp->dev, 2526 " missed pkts %u..%u\n", 2527 ppp->nextseq, 2528 PPP_MP_CB(head)->sequence-1); 2529 ++ppp->dev->stats.rx_dropped; 2530 ppp_receive_error(ppp); 2531 } 2532 2533 skb = head; 2534 if (head != tail) { 2535 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list; 2536 p = skb_queue_next(list, head); 2537 __skb_unlink(skb, list); 2538 skb_queue_walk_from_safe(list, p, tmp) { 2539 __skb_unlink(p, list); 2540 *fragpp = p; 2541 p->next = NULL; 2542 fragpp = &p->next; 2543 2544 skb->len += p->len; 2545 skb->data_len += p->len; 2546 skb->truesize += p->truesize; 2547 2548 if (p == tail) 2549 break; 2550 } 2551 } else { 2552 __skb_unlink(skb, list); 2553 } 2554 2555 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1; 2556 } 2557 2558 return skb; 2559 } 2560 #endif /* CONFIG_PPP_MULTILINK */ 2561 2562 /* 2563 * Channel interface. 2564 */ 2565 2566 /* Create a new, unattached ppp channel. */ 2567 int ppp_register_channel(struct ppp_channel *chan) 2568 { 2569 return ppp_register_net_channel(current->nsproxy->net_ns, chan); 2570 } 2571 2572 /* Create a new, unattached ppp channel for specified net. */ 2573 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan) 2574 { 2575 struct channel *pch; 2576 struct ppp_net *pn; 2577 2578 pch = kzalloc(sizeof(struct channel), GFP_KERNEL); 2579 if (!pch) 2580 return -ENOMEM; 2581 2582 pn = ppp_pernet(net); 2583 2584 pch->ppp = NULL; 2585 pch->chan = chan; 2586 pch->chan_net = get_net(net); 2587 chan->ppp = pch; 2588 init_ppp_file(&pch->file, CHANNEL); 2589 pch->file.hdrlen = chan->hdrlen; 2590 #ifdef CONFIG_PPP_MULTILINK 2591 pch->lastseq = -1; 2592 #endif /* CONFIG_PPP_MULTILINK */ 2593 init_rwsem(&pch->chan_sem); 2594 spin_lock_init(&pch->downl); 2595 rwlock_init(&pch->upl); 2596 2597 spin_lock_bh(&pn->all_channels_lock); 2598 pch->file.index = ++pn->last_channel_index; 2599 list_add(&pch->list, &pn->new_channels); 2600 atomic_inc(&channel_count); 2601 spin_unlock_bh(&pn->all_channels_lock); 2602 2603 return 0; 2604 } 2605 2606 /* 2607 * Return the index of a channel. 2608 */ 2609 int ppp_channel_index(struct ppp_channel *chan) 2610 { 2611 struct channel *pch = chan->ppp; 2612 2613 if (pch) 2614 return pch->file.index; 2615 return -1; 2616 } 2617 2618 /* 2619 * Return the PPP unit number to which a channel is connected. 2620 */ 2621 int ppp_unit_number(struct ppp_channel *chan) 2622 { 2623 struct channel *pch = chan->ppp; 2624 int unit = -1; 2625 2626 if (pch) { 2627 read_lock_bh(&pch->upl); 2628 if (pch->ppp) 2629 unit = pch->ppp->file.index; 2630 read_unlock_bh(&pch->upl); 2631 } 2632 return unit; 2633 } 2634 2635 /* 2636 * Return the PPP device interface name of a channel. 2637 */ 2638 char *ppp_dev_name(struct ppp_channel *chan) 2639 { 2640 struct channel *pch = chan->ppp; 2641 char *name = NULL; 2642 2643 if (pch) { 2644 read_lock_bh(&pch->upl); 2645 if (pch->ppp && pch->ppp->dev) 2646 name = pch->ppp->dev->name; 2647 read_unlock_bh(&pch->upl); 2648 } 2649 return name; 2650 } 2651 2652 2653 /* 2654 * Disconnect a channel from the generic layer. 2655 * This must be called in process context. 2656 */ 2657 void 2658 ppp_unregister_channel(struct ppp_channel *chan) 2659 { 2660 struct channel *pch = chan->ppp; 2661 struct ppp_net *pn; 2662 2663 if (!pch) 2664 return; /* should never happen */ 2665 2666 chan->ppp = NULL; 2667 2668 /* 2669 * This ensures that we have returned from any calls into the 2670 * the channel's start_xmit or ioctl routine before we proceed. 2671 */ 2672 down_write(&pch->chan_sem); 2673 spin_lock_bh(&pch->downl); 2674 pch->chan = NULL; 2675 spin_unlock_bh(&pch->downl); 2676 up_write(&pch->chan_sem); 2677 ppp_disconnect_channel(pch); 2678 2679 pn = ppp_pernet(pch->chan_net); 2680 spin_lock_bh(&pn->all_channels_lock); 2681 list_del(&pch->list); 2682 spin_unlock_bh(&pn->all_channels_lock); 2683 2684 pch->file.dead = 1; 2685 wake_up_interruptible(&pch->file.rwait); 2686 if (refcount_dec_and_test(&pch->file.refcnt)) 2687 ppp_destroy_channel(pch); 2688 } 2689 2690 /* 2691 * Callback from a channel when it can accept more to transmit. 2692 * This should be called at BH/softirq level, not interrupt level. 2693 */ 2694 void 2695 ppp_output_wakeup(struct ppp_channel *chan) 2696 { 2697 struct channel *pch = chan->ppp; 2698 2699 if (!pch) 2700 return; 2701 ppp_channel_push(pch); 2702 } 2703 2704 /* 2705 * Compression control. 2706 */ 2707 2708 /* Process the PPPIOCSCOMPRESS ioctl. */ 2709 static int 2710 ppp_set_compress(struct ppp *ppp, unsigned long arg) 2711 { 2712 int err; 2713 struct compressor *cp, *ocomp; 2714 struct ppp_option_data data; 2715 void *state, *ostate; 2716 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH]; 2717 2718 err = -EFAULT; 2719 if (copy_from_user(&data, (void __user *) arg, sizeof(data))) 2720 goto out; 2721 if (data.length > CCP_MAX_OPTION_LENGTH) 2722 goto out; 2723 if (copy_from_user(ccp_option, (void __user *) data.ptr, data.length)) 2724 goto out; 2725 2726 err = -EINVAL; 2727 if (data.length < 2 || ccp_option[1] < 2 || ccp_option[1] > data.length) 2728 goto out; 2729 2730 cp = try_then_request_module( 2731 find_compressor(ccp_option[0]), 2732 "ppp-compress-%d", ccp_option[0]); 2733 if (!cp) 2734 goto out; 2735 2736 err = -ENOBUFS; 2737 if (data.transmit) { 2738 state = cp->comp_alloc(ccp_option, data.length); 2739 if (state) { 2740 ppp_xmit_lock(ppp); 2741 ppp->xstate &= ~SC_COMP_RUN; 2742 ocomp = ppp->xcomp; 2743 ostate = ppp->xc_state; 2744 ppp->xcomp = cp; 2745 ppp->xc_state = state; 2746 ppp_xmit_unlock(ppp); 2747 if (ostate) { 2748 ocomp->comp_free(ostate); 2749 module_put(ocomp->owner); 2750 } 2751 err = 0; 2752 } else 2753 module_put(cp->owner); 2754 2755 } else { 2756 state = cp->decomp_alloc(ccp_option, data.length); 2757 if (state) { 2758 ppp_recv_lock(ppp); 2759 ppp->rstate &= ~SC_DECOMP_RUN; 2760 ocomp = ppp->rcomp; 2761 ostate = ppp->rc_state; 2762 ppp->rcomp = cp; 2763 ppp->rc_state = state; 2764 ppp_recv_unlock(ppp); 2765 if (ostate) { 2766 ocomp->decomp_free(ostate); 2767 module_put(ocomp->owner); 2768 } 2769 err = 0; 2770 } else 2771 module_put(cp->owner); 2772 } 2773 2774 out: 2775 return err; 2776 } 2777 2778 /* 2779 * Look at a CCP packet and update our state accordingly. 2780 * We assume the caller has the xmit or recv path locked. 2781 */ 2782 static void 2783 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound) 2784 { 2785 unsigned char *dp; 2786 int len; 2787 2788 if (!pskb_may_pull(skb, CCP_HDRLEN + 2)) 2789 return; /* no header */ 2790 dp = skb->data + 2; 2791 2792 switch (CCP_CODE(dp)) { 2793 case CCP_CONFREQ: 2794 2795 /* A ConfReq starts negotiation of compression 2796 * in one direction of transmission, 2797 * and hence brings it down...but which way? 2798 * 2799 * Remember: 2800 * A ConfReq indicates what the sender would like to receive 2801 */ 2802 if(inbound) 2803 /* He is proposing what I should send */ 2804 ppp->xstate &= ~SC_COMP_RUN; 2805 else 2806 /* I am proposing to what he should send */ 2807 ppp->rstate &= ~SC_DECOMP_RUN; 2808 2809 break; 2810 2811 case CCP_TERMREQ: 2812 case CCP_TERMACK: 2813 /* 2814 * CCP is going down, both directions of transmission 2815 */ 2816 ppp->rstate &= ~SC_DECOMP_RUN; 2817 ppp->xstate &= ~SC_COMP_RUN; 2818 break; 2819 2820 case CCP_CONFACK: 2821 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN) 2822 break; 2823 len = CCP_LENGTH(dp); 2824 if (!pskb_may_pull(skb, len + 2)) 2825 return; /* too short */ 2826 dp += CCP_HDRLEN; 2827 len -= CCP_HDRLEN; 2828 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp)) 2829 break; 2830 if (inbound) { 2831 /* we will start receiving compressed packets */ 2832 if (!ppp->rc_state) 2833 break; 2834 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len, 2835 ppp->file.index, 0, ppp->mru, ppp->debug)) { 2836 ppp->rstate |= SC_DECOMP_RUN; 2837 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR); 2838 } 2839 } else { 2840 /* we will soon start sending compressed packets */ 2841 if (!ppp->xc_state) 2842 break; 2843 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len, 2844 ppp->file.index, 0, ppp->debug)) 2845 ppp->xstate |= SC_COMP_RUN; 2846 } 2847 break; 2848 2849 case CCP_RESETACK: 2850 /* reset the [de]compressor */ 2851 if ((ppp->flags & SC_CCP_UP) == 0) 2852 break; 2853 if (inbound) { 2854 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) { 2855 ppp->rcomp->decomp_reset(ppp->rc_state); 2856 ppp->rstate &= ~SC_DC_ERROR; 2857 } 2858 } else { 2859 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN)) 2860 ppp->xcomp->comp_reset(ppp->xc_state); 2861 } 2862 break; 2863 } 2864 } 2865 2866 /* Free up compression resources. */ 2867 static void 2868 ppp_ccp_closed(struct ppp *ppp) 2869 { 2870 void *xstate, *rstate; 2871 struct compressor *xcomp, *rcomp; 2872 2873 ppp_lock(ppp); 2874 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP); 2875 ppp->xstate = 0; 2876 xcomp = ppp->xcomp; 2877 xstate = ppp->xc_state; 2878 ppp->xc_state = NULL; 2879 ppp->rstate = 0; 2880 rcomp = ppp->rcomp; 2881 rstate = ppp->rc_state; 2882 ppp->rc_state = NULL; 2883 ppp_unlock(ppp); 2884 2885 if (xstate) { 2886 xcomp->comp_free(xstate); 2887 module_put(xcomp->owner); 2888 } 2889 if (rstate) { 2890 rcomp->decomp_free(rstate); 2891 module_put(rcomp->owner); 2892 } 2893 } 2894 2895 /* List of compressors. */ 2896 static LIST_HEAD(compressor_list); 2897 static DEFINE_SPINLOCK(compressor_list_lock); 2898 2899 struct compressor_entry { 2900 struct list_head list; 2901 struct compressor *comp; 2902 }; 2903 2904 static struct compressor_entry * 2905 find_comp_entry(int proto) 2906 { 2907 struct compressor_entry *ce; 2908 2909 list_for_each_entry(ce, &compressor_list, list) { 2910 if (ce->comp->compress_proto == proto) 2911 return ce; 2912 } 2913 return NULL; 2914 } 2915 2916 /* Register a compressor */ 2917 int 2918 ppp_register_compressor(struct compressor *cp) 2919 { 2920 struct compressor_entry *ce; 2921 int ret; 2922 spin_lock(&compressor_list_lock); 2923 ret = -EEXIST; 2924 if (find_comp_entry(cp->compress_proto)) 2925 goto out; 2926 ret = -ENOMEM; 2927 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC); 2928 if (!ce) 2929 goto out; 2930 ret = 0; 2931 ce->comp = cp; 2932 list_add(&ce->list, &compressor_list); 2933 out: 2934 spin_unlock(&compressor_list_lock); 2935 return ret; 2936 } 2937 2938 /* Unregister a compressor */ 2939 void 2940 ppp_unregister_compressor(struct compressor *cp) 2941 { 2942 struct compressor_entry *ce; 2943 2944 spin_lock(&compressor_list_lock); 2945 ce = find_comp_entry(cp->compress_proto); 2946 if (ce && ce->comp == cp) { 2947 list_del(&ce->list); 2948 kfree(ce); 2949 } 2950 spin_unlock(&compressor_list_lock); 2951 } 2952 2953 /* Find a compressor. */ 2954 static struct compressor * 2955 find_compressor(int type) 2956 { 2957 struct compressor_entry *ce; 2958 struct compressor *cp = NULL; 2959 2960 spin_lock(&compressor_list_lock); 2961 ce = find_comp_entry(type); 2962 if (ce) { 2963 cp = ce->comp; 2964 if (!try_module_get(cp->owner)) 2965 cp = NULL; 2966 } 2967 spin_unlock(&compressor_list_lock); 2968 return cp; 2969 } 2970 2971 /* 2972 * Miscelleneous stuff. 2973 */ 2974 2975 static void 2976 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st) 2977 { 2978 struct slcompress *vj = ppp->vj; 2979 2980 memset(st, 0, sizeof(*st)); 2981 st->p.ppp_ipackets = ppp->stats64.rx_packets; 2982 st->p.ppp_ierrors = ppp->dev->stats.rx_errors; 2983 st->p.ppp_ibytes = ppp->stats64.rx_bytes; 2984 st->p.ppp_opackets = ppp->stats64.tx_packets; 2985 st->p.ppp_oerrors = ppp->dev->stats.tx_errors; 2986 st->p.ppp_obytes = ppp->stats64.tx_bytes; 2987 if (!vj) 2988 return; 2989 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed; 2990 st->vj.vjs_compressed = vj->sls_o_compressed; 2991 st->vj.vjs_searches = vj->sls_o_searches; 2992 st->vj.vjs_misses = vj->sls_o_misses; 2993 st->vj.vjs_errorin = vj->sls_i_error; 2994 st->vj.vjs_tossed = vj->sls_i_tossed; 2995 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed; 2996 st->vj.vjs_compressedin = vj->sls_i_compressed; 2997 } 2998 2999 /* 3000 * Stuff for handling the lists of ppp units and channels 3001 * and for initialization. 3002 */ 3003 3004 /* 3005 * Create a new ppp interface unit. Fails if it can't allocate memory 3006 * or if there is already a unit with the requested number. 3007 * unit == -1 means allocate a new number. 3008 */ 3009 static int ppp_create_interface(struct net *net, struct file *file, int *unit) 3010 { 3011 struct ppp_config conf = { 3012 .file = file, 3013 .unit = *unit, 3014 .ifname_is_set = false, 3015 }; 3016 struct net_device *dev; 3017 struct ppp *ppp; 3018 int err; 3019 3020 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup); 3021 if (!dev) { 3022 err = -ENOMEM; 3023 goto err; 3024 } 3025 dev_net_set(dev, net); 3026 dev->rtnl_link_ops = &ppp_link_ops; 3027 3028 rtnl_lock(); 3029 3030 err = ppp_dev_configure(net, dev, &conf); 3031 if (err < 0) 3032 goto err_dev; 3033 ppp = netdev_priv(dev); 3034 *unit = ppp->file.index; 3035 3036 rtnl_unlock(); 3037 3038 return 0; 3039 3040 err_dev: 3041 rtnl_unlock(); 3042 free_netdev(dev); 3043 err: 3044 return err; 3045 } 3046 3047 /* 3048 * Initialize a ppp_file structure. 3049 */ 3050 static void 3051 init_ppp_file(struct ppp_file *pf, int kind) 3052 { 3053 pf->kind = kind; 3054 skb_queue_head_init(&pf->xq); 3055 skb_queue_head_init(&pf->rq); 3056 refcount_set(&pf->refcnt, 1); 3057 init_waitqueue_head(&pf->rwait); 3058 } 3059 3060 /* 3061 * Free the memory used by a ppp unit. This is only called once 3062 * there are no channels connected to the unit and no file structs 3063 * that reference the unit. 3064 */ 3065 static void ppp_destroy_interface(struct ppp *ppp) 3066 { 3067 atomic_dec(&ppp_unit_count); 3068 3069 if (!ppp->file.dead || ppp->n_channels) { 3070 /* "can't happen" */ 3071 netdev_err(ppp->dev, "ppp: destroying ppp struct %p " 3072 "but dead=%d n_channels=%d !\n", 3073 ppp, ppp->file.dead, ppp->n_channels); 3074 return; 3075 } 3076 3077 ppp_ccp_closed(ppp); 3078 if (ppp->vj) { 3079 slhc_free(ppp->vj); 3080 ppp->vj = NULL; 3081 } 3082 skb_queue_purge(&ppp->file.xq); 3083 skb_queue_purge(&ppp->file.rq); 3084 #ifdef CONFIG_PPP_MULTILINK 3085 skb_queue_purge(&ppp->mrq); 3086 #endif /* CONFIG_PPP_MULTILINK */ 3087 #ifdef CONFIG_PPP_FILTER 3088 if (ppp->pass_filter) { 3089 bpf_prog_destroy(ppp->pass_filter); 3090 ppp->pass_filter = NULL; 3091 } 3092 3093 if (ppp->active_filter) { 3094 bpf_prog_destroy(ppp->active_filter); 3095 ppp->active_filter = NULL; 3096 } 3097 #endif /* CONFIG_PPP_FILTER */ 3098 3099 kfree_skb(ppp->xmit_pending); 3100 free_percpu(ppp->xmit_recursion); 3101 3102 free_netdev(ppp->dev); 3103 } 3104 3105 /* 3106 * Locate an existing ppp unit. 3107 * The caller should have locked the all_ppp_mutex. 3108 */ 3109 static struct ppp * 3110 ppp_find_unit(struct ppp_net *pn, int unit) 3111 { 3112 return unit_find(&pn->units_idr, unit); 3113 } 3114 3115 /* 3116 * Locate an existing ppp channel. 3117 * The caller should have locked the all_channels_lock. 3118 * First we look in the new_channels list, then in the 3119 * all_channels list. If found in the new_channels list, 3120 * we move it to the all_channels list. This is for speed 3121 * when we have a lot of channels in use. 3122 */ 3123 static struct channel * 3124 ppp_find_channel(struct ppp_net *pn, int unit) 3125 { 3126 struct channel *pch; 3127 3128 list_for_each_entry(pch, &pn->new_channels, list) { 3129 if (pch->file.index == unit) { 3130 list_move(&pch->list, &pn->all_channels); 3131 return pch; 3132 } 3133 } 3134 3135 list_for_each_entry(pch, &pn->all_channels, list) { 3136 if (pch->file.index == unit) 3137 return pch; 3138 } 3139 3140 return NULL; 3141 } 3142 3143 /* 3144 * Connect a PPP channel to a PPP interface unit. 3145 */ 3146 static int 3147 ppp_connect_channel(struct channel *pch, int unit) 3148 { 3149 struct ppp *ppp; 3150 struct ppp_net *pn; 3151 int ret = -ENXIO; 3152 int hdrlen; 3153 3154 pn = ppp_pernet(pch->chan_net); 3155 3156 mutex_lock(&pn->all_ppp_mutex); 3157 ppp = ppp_find_unit(pn, unit); 3158 if (!ppp) 3159 goto out; 3160 write_lock_bh(&pch->upl); 3161 ret = -EINVAL; 3162 if (pch->ppp) 3163 goto outl; 3164 3165 ppp_lock(ppp); 3166 spin_lock_bh(&pch->downl); 3167 if (!pch->chan) { 3168 /* Don't connect unregistered channels */ 3169 spin_unlock_bh(&pch->downl); 3170 ppp_unlock(ppp); 3171 ret = -ENOTCONN; 3172 goto outl; 3173 } 3174 spin_unlock_bh(&pch->downl); 3175 if (pch->file.hdrlen > ppp->file.hdrlen) 3176 ppp->file.hdrlen = pch->file.hdrlen; 3177 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */ 3178 if (hdrlen > ppp->dev->hard_header_len) 3179 ppp->dev->hard_header_len = hdrlen; 3180 list_add_tail(&pch->clist, &ppp->channels); 3181 ++ppp->n_channels; 3182 pch->ppp = ppp; 3183 refcount_inc(&ppp->file.refcnt); 3184 ppp_unlock(ppp); 3185 ret = 0; 3186 3187 outl: 3188 write_unlock_bh(&pch->upl); 3189 out: 3190 mutex_unlock(&pn->all_ppp_mutex); 3191 return ret; 3192 } 3193 3194 /* 3195 * Disconnect a channel from its ppp unit. 3196 */ 3197 static int 3198 ppp_disconnect_channel(struct channel *pch) 3199 { 3200 struct ppp *ppp; 3201 int err = -EINVAL; 3202 3203 write_lock_bh(&pch->upl); 3204 ppp = pch->ppp; 3205 pch->ppp = NULL; 3206 write_unlock_bh(&pch->upl); 3207 if (ppp) { 3208 /* remove it from the ppp unit's list */ 3209 ppp_lock(ppp); 3210 list_del(&pch->clist); 3211 if (--ppp->n_channels == 0) 3212 wake_up_interruptible(&ppp->file.rwait); 3213 ppp_unlock(ppp); 3214 if (refcount_dec_and_test(&ppp->file.refcnt)) 3215 ppp_destroy_interface(ppp); 3216 err = 0; 3217 } 3218 return err; 3219 } 3220 3221 /* 3222 * Free up the resources used by a ppp channel. 3223 */ 3224 static void ppp_destroy_channel(struct channel *pch) 3225 { 3226 put_net(pch->chan_net); 3227 pch->chan_net = NULL; 3228 3229 atomic_dec(&channel_count); 3230 3231 if (!pch->file.dead) { 3232 /* "can't happen" */ 3233 pr_err("ppp: destroying undead channel %p !\n", pch); 3234 return; 3235 } 3236 skb_queue_purge(&pch->file.xq); 3237 skb_queue_purge(&pch->file.rq); 3238 kfree(pch); 3239 } 3240 3241 static void __exit ppp_cleanup(void) 3242 { 3243 /* should never happen */ 3244 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count)) 3245 pr_err("PPP: removing module but units remain!\n"); 3246 rtnl_link_unregister(&ppp_link_ops); 3247 unregister_chrdev(PPP_MAJOR, "ppp"); 3248 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0)); 3249 class_destroy(ppp_class); 3250 unregister_pernet_device(&ppp_net_ops); 3251 } 3252 3253 /* 3254 * Units handling. Caller must protect concurrent access 3255 * by holding all_ppp_mutex 3256 */ 3257 3258 /* associate pointer with specified number */ 3259 static int unit_set(struct idr *p, void *ptr, int n) 3260 { 3261 int unit; 3262 3263 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL); 3264 if (unit == -ENOSPC) 3265 unit = -EINVAL; 3266 return unit; 3267 } 3268 3269 /* get new free unit number and associate pointer with it */ 3270 static int unit_get(struct idr *p, void *ptr) 3271 { 3272 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL); 3273 } 3274 3275 /* put unit number back to a pool */ 3276 static void unit_put(struct idr *p, int n) 3277 { 3278 idr_remove(p, n); 3279 } 3280 3281 /* get pointer associated with the number */ 3282 static void *unit_find(struct idr *p, int n) 3283 { 3284 return idr_find(p, n); 3285 } 3286 3287 /* Module/initialization stuff */ 3288 3289 module_init(ppp_init); 3290 module_exit(ppp_cleanup); 3291 3292 EXPORT_SYMBOL(ppp_register_net_channel); 3293 EXPORT_SYMBOL(ppp_register_channel); 3294 EXPORT_SYMBOL(ppp_unregister_channel); 3295 EXPORT_SYMBOL(ppp_channel_index); 3296 EXPORT_SYMBOL(ppp_unit_number); 3297 EXPORT_SYMBOL(ppp_dev_name); 3298 EXPORT_SYMBOL(ppp_input); 3299 EXPORT_SYMBOL(ppp_input_error); 3300 EXPORT_SYMBOL(ppp_output_wakeup); 3301 EXPORT_SYMBOL(ppp_register_compressor); 3302 EXPORT_SYMBOL(ppp_unregister_compressor); 3303 MODULE_LICENSE("GPL"); 3304 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0); 3305 MODULE_ALIAS_RTNL_LINK("ppp"); 3306 MODULE_ALIAS("devname:ppp"); 3307