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