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 __poll_t ppp_poll(struct file *file, poll_table *wait) 535 { 536 struct ppp_file *pf = file->private_data; 537 __poll_t mask; 538 539 if (!pf) 540 return 0; 541 poll_wait(file, &pf->rwait, wait); 542 mask = EPOLLOUT | EPOLLWRNORM; 543 if (skb_peek(&pf->rq)) 544 mask |= EPOLLIN | EPOLLRDNORM; 545 if (pf->dead) 546 mask |= EPOLLHUP; 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 |= EPOLLIN | EPOLLRDNORM; 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 WARN_ON_ONCE(!list_empty(&pn->all_channels)); 966 WARN_ON_ONCE(!list_empty(&pn->new_channels)); 967 } 968 969 static struct pernet_operations ppp_net_ops = { 970 .init = ppp_init_net, 971 .exit = ppp_exit_net, 972 .id = &ppp_net_id, 973 .size = sizeof(struct ppp_net), 974 }; 975 976 static int ppp_unit_register(struct ppp *ppp, int unit, bool ifname_is_set) 977 { 978 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 979 int ret; 980 981 mutex_lock(&pn->all_ppp_mutex); 982 983 if (unit < 0) { 984 ret = unit_get(&pn->units_idr, ppp); 985 if (ret < 0) 986 goto err; 987 } else { 988 /* Caller asked for a specific unit number. Fail with -EEXIST 989 * if unavailable. For backward compatibility, return -EEXIST 990 * too if idr allocation fails; this makes pppd retry without 991 * requesting a specific unit number. 992 */ 993 if (unit_find(&pn->units_idr, unit)) { 994 ret = -EEXIST; 995 goto err; 996 } 997 ret = unit_set(&pn->units_idr, ppp, unit); 998 if (ret < 0) { 999 /* Rewrite error for backward compatibility */ 1000 ret = -EEXIST; 1001 goto err; 1002 } 1003 } 1004 ppp->file.index = ret; 1005 1006 if (!ifname_is_set) 1007 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ppp->file.index); 1008 1009 mutex_unlock(&pn->all_ppp_mutex); 1010 1011 ret = register_netdevice(ppp->dev); 1012 if (ret < 0) 1013 goto err_unit; 1014 1015 atomic_inc(&ppp_unit_count); 1016 1017 return 0; 1018 1019 err_unit: 1020 mutex_lock(&pn->all_ppp_mutex); 1021 unit_put(&pn->units_idr, ppp->file.index); 1022 err: 1023 mutex_unlock(&pn->all_ppp_mutex); 1024 1025 return ret; 1026 } 1027 1028 static int ppp_dev_configure(struct net *src_net, struct net_device *dev, 1029 const struct ppp_config *conf) 1030 { 1031 struct ppp *ppp = netdev_priv(dev); 1032 int indx; 1033 int err; 1034 int cpu; 1035 1036 ppp->dev = dev; 1037 ppp->ppp_net = src_net; 1038 ppp->mru = PPP_MRU; 1039 ppp->owner = conf->file; 1040 1041 init_ppp_file(&ppp->file, INTERFACE); 1042 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */ 1043 1044 for (indx = 0; indx < NUM_NP; ++indx) 1045 ppp->npmode[indx] = NPMODE_PASS; 1046 INIT_LIST_HEAD(&ppp->channels); 1047 spin_lock_init(&ppp->rlock); 1048 spin_lock_init(&ppp->wlock); 1049 1050 ppp->xmit_recursion = alloc_percpu(int); 1051 if (!ppp->xmit_recursion) { 1052 err = -ENOMEM; 1053 goto err1; 1054 } 1055 for_each_possible_cpu(cpu) 1056 (*per_cpu_ptr(ppp->xmit_recursion, cpu)) = 0; 1057 1058 #ifdef CONFIG_PPP_MULTILINK 1059 ppp->minseq = -1; 1060 skb_queue_head_init(&ppp->mrq); 1061 #endif /* CONFIG_PPP_MULTILINK */ 1062 #ifdef CONFIG_PPP_FILTER 1063 ppp->pass_filter = NULL; 1064 ppp->active_filter = NULL; 1065 #endif /* CONFIG_PPP_FILTER */ 1066 1067 err = ppp_unit_register(ppp, conf->unit, conf->ifname_is_set); 1068 if (err < 0) 1069 goto err2; 1070 1071 conf->file->private_data = &ppp->file; 1072 1073 return 0; 1074 err2: 1075 free_percpu(ppp->xmit_recursion); 1076 err1: 1077 return err; 1078 } 1079 1080 static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = { 1081 [IFLA_PPP_DEV_FD] = { .type = NLA_S32 }, 1082 }; 1083 1084 static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[], 1085 struct netlink_ext_ack *extack) 1086 { 1087 if (!data) 1088 return -EINVAL; 1089 1090 if (!data[IFLA_PPP_DEV_FD]) 1091 return -EINVAL; 1092 if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0) 1093 return -EBADF; 1094 1095 return 0; 1096 } 1097 1098 static int ppp_nl_newlink(struct net *src_net, struct net_device *dev, 1099 struct nlattr *tb[], struct nlattr *data[], 1100 struct netlink_ext_ack *extack) 1101 { 1102 struct ppp_config conf = { 1103 .unit = -1, 1104 .ifname_is_set = true, 1105 }; 1106 struct file *file; 1107 int err; 1108 1109 file = fget(nla_get_s32(data[IFLA_PPP_DEV_FD])); 1110 if (!file) 1111 return -EBADF; 1112 1113 /* rtnl_lock is already held here, but ppp_create_interface() locks 1114 * ppp_mutex before holding rtnl_lock. Using mutex_trylock() avoids 1115 * possible deadlock due to lock order inversion, at the cost of 1116 * pushing the problem back to userspace. 1117 */ 1118 if (!mutex_trylock(&ppp_mutex)) { 1119 err = -EBUSY; 1120 goto out; 1121 } 1122 1123 if (file->f_op != &ppp_device_fops || file->private_data) { 1124 err = -EBADF; 1125 goto out_unlock; 1126 } 1127 1128 conf.file = file; 1129 1130 /* Don't use device name generated by the rtnetlink layer when ifname 1131 * isn't specified. Let ppp_dev_configure() set the device name using 1132 * the PPP unit identifer as suffix (i.e. ppp<unit_id>). This allows 1133 * userspace to infer the device name using to the PPPIOCGUNIT ioctl. 1134 */ 1135 if (!tb[IFLA_IFNAME]) 1136 conf.ifname_is_set = false; 1137 1138 err = ppp_dev_configure(src_net, dev, &conf); 1139 1140 out_unlock: 1141 mutex_unlock(&ppp_mutex); 1142 out: 1143 fput(file); 1144 1145 return err; 1146 } 1147 1148 static void ppp_nl_dellink(struct net_device *dev, struct list_head *head) 1149 { 1150 unregister_netdevice_queue(dev, head); 1151 } 1152 1153 static size_t ppp_nl_get_size(const struct net_device *dev) 1154 { 1155 return 0; 1156 } 1157 1158 static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev) 1159 { 1160 return 0; 1161 } 1162 1163 static struct net *ppp_nl_get_link_net(const struct net_device *dev) 1164 { 1165 struct ppp *ppp = netdev_priv(dev); 1166 1167 return ppp->ppp_net; 1168 } 1169 1170 static struct rtnl_link_ops ppp_link_ops __read_mostly = { 1171 .kind = "ppp", 1172 .maxtype = IFLA_PPP_MAX, 1173 .policy = ppp_nl_policy, 1174 .priv_size = sizeof(struct ppp), 1175 .setup = ppp_setup, 1176 .validate = ppp_nl_validate, 1177 .newlink = ppp_nl_newlink, 1178 .dellink = ppp_nl_dellink, 1179 .get_size = ppp_nl_get_size, 1180 .fill_info = ppp_nl_fill_info, 1181 .get_link_net = ppp_nl_get_link_net, 1182 }; 1183 1184 #define PPP_MAJOR 108 1185 1186 /* Called at boot time if ppp is compiled into the kernel, 1187 or at module load time (from init_module) if compiled as a module. */ 1188 static int __init ppp_init(void) 1189 { 1190 int err; 1191 1192 pr_info("PPP generic driver version " PPP_VERSION "\n"); 1193 1194 err = register_pernet_device(&ppp_net_ops); 1195 if (err) { 1196 pr_err("failed to register PPP pernet device (%d)\n", err); 1197 goto out; 1198 } 1199 1200 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops); 1201 if (err) { 1202 pr_err("failed to register PPP device (%d)\n", err); 1203 goto out_net; 1204 } 1205 1206 ppp_class = class_create(THIS_MODULE, "ppp"); 1207 if (IS_ERR(ppp_class)) { 1208 err = PTR_ERR(ppp_class); 1209 goto out_chrdev; 1210 } 1211 1212 err = rtnl_link_register(&ppp_link_ops); 1213 if (err) { 1214 pr_err("failed to register rtnetlink PPP handler\n"); 1215 goto out_class; 1216 } 1217 1218 /* not a big deal if we fail here :-) */ 1219 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp"); 1220 1221 return 0; 1222 1223 out_class: 1224 class_destroy(ppp_class); 1225 out_chrdev: 1226 unregister_chrdev(PPP_MAJOR, "ppp"); 1227 out_net: 1228 unregister_pernet_device(&ppp_net_ops); 1229 out: 1230 return err; 1231 } 1232 1233 /* 1234 * Network interface unit routines. 1235 */ 1236 static netdev_tx_t 1237 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev) 1238 { 1239 struct ppp *ppp = netdev_priv(dev); 1240 int npi, proto; 1241 unsigned char *pp; 1242 1243 npi = ethertype_to_npindex(ntohs(skb->protocol)); 1244 if (npi < 0) 1245 goto outf; 1246 1247 /* Drop, accept or reject the packet */ 1248 switch (ppp->npmode[npi]) { 1249 case NPMODE_PASS: 1250 break; 1251 case NPMODE_QUEUE: 1252 /* it would be nice to have a way to tell the network 1253 system to queue this one up for later. */ 1254 goto outf; 1255 case NPMODE_DROP: 1256 case NPMODE_ERROR: 1257 goto outf; 1258 } 1259 1260 /* Put the 2-byte PPP protocol number on the front, 1261 making sure there is room for the address and control fields. */ 1262 if (skb_cow_head(skb, PPP_HDRLEN)) 1263 goto outf; 1264 1265 pp = skb_push(skb, 2); 1266 proto = npindex_to_proto[npi]; 1267 put_unaligned_be16(proto, pp); 1268 1269 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev))); 1270 skb_queue_tail(&ppp->file.xq, skb); 1271 ppp_xmit_process(ppp); 1272 return NETDEV_TX_OK; 1273 1274 outf: 1275 kfree_skb(skb); 1276 ++dev->stats.tx_dropped; 1277 return NETDEV_TX_OK; 1278 } 1279 1280 static int 1281 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 1282 { 1283 struct ppp *ppp = netdev_priv(dev); 1284 int err = -EFAULT; 1285 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data; 1286 struct ppp_stats stats; 1287 struct ppp_comp_stats cstats; 1288 char *vers; 1289 1290 switch (cmd) { 1291 case SIOCGPPPSTATS: 1292 ppp_get_stats(ppp, &stats); 1293 if (copy_to_user(addr, &stats, sizeof(stats))) 1294 break; 1295 err = 0; 1296 break; 1297 1298 case SIOCGPPPCSTATS: 1299 memset(&cstats, 0, sizeof(cstats)); 1300 if (ppp->xc_state) 1301 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c); 1302 if (ppp->rc_state) 1303 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d); 1304 if (copy_to_user(addr, &cstats, sizeof(cstats))) 1305 break; 1306 err = 0; 1307 break; 1308 1309 case SIOCGPPPVER: 1310 vers = PPP_VERSION; 1311 if (copy_to_user(addr, vers, strlen(vers) + 1)) 1312 break; 1313 err = 0; 1314 break; 1315 1316 default: 1317 err = -EINVAL; 1318 } 1319 1320 return err; 1321 } 1322 1323 static void 1324 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64) 1325 { 1326 struct ppp *ppp = netdev_priv(dev); 1327 1328 ppp_recv_lock(ppp); 1329 stats64->rx_packets = ppp->stats64.rx_packets; 1330 stats64->rx_bytes = ppp->stats64.rx_bytes; 1331 ppp_recv_unlock(ppp); 1332 1333 ppp_xmit_lock(ppp); 1334 stats64->tx_packets = ppp->stats64.tx_packets; 1335 stats64->tx_bytes = ppp->stats64.tx_bytes; 1336 ppp_xmit_unlock(ppp); 1337 1338 stats64->rx_errors = dev->stats.rx_errors; 1339 stats64->tx_errors = dev->stats.tx_errors; 1340 stats64->rx_dropped = dev->stats.rx_dropped; 1341 stats64->tx_dropped = dev->stats.tx_dropped; 1342 stats64->rx_length_errors = dev->stats.rx_length_errors; 1343 } 1344 1345 static int ppp_dev_init(struct net_device *dev) 1346 { 1347 struct ppp *ppp; 1348 1349 netdev_lockdep_set_classes(dev); 1350 1351 ppp = netdev_priv(dev); 1352 /* Let the netdevice take a reference on the ppp file. This ensures 1353 * that ppp_destroy_interface() won't run before the device gets 1354 * unregistered. 1355 */ 1356 refcount_inc(&ppp->file.refcnt); 1357 1358 return 0; 1359 } 1360 1361 static void ppp_dev_uninit(struct net_device *dev) 1362 { 1363 struct ppp *ppp = netdev_priv(dev); 1364 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 1365 1366 ppp_lock(ppp); 1367 ppp->closing = 1; 1368 ppp_unlock(ppp); 1369 1370 mutex_lock(&pn->all_ppp_mutex); 1371 unit_put(&pn->units_idr, ppp->file.index); 1372 mutex_unlock(&pn->all_ppp_mutex); 1373 1374 ppp->owner = NULL; 1375 1376 ppp->file.dead = 1; 1377 wake_up_interruptible(&ppp->file.rwait); 1378 } 1379 1380 static void ppp_dev_priv_destructor(struct net_device *dev) 1381 { 1382 struct ppp *ppp; 1383 1384 ppp = netdev_priv(dev); 1385 if (refcount_dec_and_test(&ppp->file.refcnt)) 1386 ppp_destroy_interface(ppp); 1387 } 1388 1389 static const struct net_device_ops ppp_netdev_ops = { 1390 .ndo_init = ppp_dev_init, 1391 .ndo_uninit = ppp_dev_uninit, 1392 .ndo_start_xmit = ppp_start_xmit, 1393 .ndo_do_ioctl = ppp_net_ioctl, 1394 .ndo_get_stats64 = ppp_get_stats64, 1395 }; 1396 1397 static struct device_type ppp_type = { 1398 .name = "ppp", 1399 }; 1400 1401 static void ppp_setup(struct net_device *dev) 1402 { 1403 dev->netdev_ops = &ppp_netdev_ops; 1404 SET_NETDEV_DEVTYPE(dev, &ppp_type); 1405 1406 dev->features |= NETIF_F_LLTX; 1407 1408 dev->hard_header_len = PPP_HDRLEN; 1409 dev->mtu = PPP_MRU; 1410 dev->addr_len = 0; 1411 dev->tx_queue_len = 3; 1412 dev->type = ARPHRD_PPP; 1413 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 1414 dev->priv_destructor = ppp_dev_priv_destructor; 1415 netif_keep_dst(dev); 1416 } 1417 1418 /* 1419 * Transmit-side routines. 1420 */ 1421 1422 /* Called to do any work queued up on the transmit side that can now be done */ 1423 static void __ppp_xmit_process(struct ppp *ppp) 1424 { 1425 struct sk_buff *skb; 1426 1427 ppp_xmit_lock(ppp); 1428 if (!ppp->closing) { 1429 ppp_push(ppp); 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) 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); 1452 (*this_cpu_ptr(ppp->xmit_recursion))--; 1453 1454 local_bh_enable(); 1455 1456 return; 1457 1458 err: 1459 local_bh_enable(); 1460 1461 if (net_ratelimit()) 1462 netdev_err(ppp->dev, "recursion detected\n"); 1463 } 1464 1465 static inline struct sk_buff * 1466 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) 1467 { 1468 struct sk_buff *new_skb; 1469 int len; 1470 int new_skb_size = ppp->dev->mtu + 1471 ppp->xcomp->comp_extra + ppp->dev->hard_header_len; 1472 int compressor_skb_size = ppp->dev->mtu + 1473 ppp->xcomp->comp_extra + PPP_HDRLEN; 1474 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC); 1475 if (!new_skb) { 1476 if (net_ratelimit()) 1477 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n"); 1478 return NULL; 1479 } 1480 if (ppp->dev->hard_header_len > PPP_HDRLEN) 1481 skb_reserve(new_skb, 1482 ppp->dev->hard_header_len - PPP_HDRLEN); 1483 1484 /* compressor still expects A/C bytes in hdr */ 1485 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, 1486 new_skb->data, skb->len + 2, 1487 compressor_skb_size); 1488 if (len > 0 && (ppp->flags & SC_CCP_UP)) { 1489 consume_skb(skb); 1490 skb = new_skb; 1491 skb_put(skb, len); 1492 skb_pull(skb, 2); /* pull off A/C bytes */ 1493 } else if (len == 0) { 1494 /* didn't compress, or CCP not up yet */ 1495 consume_skb(new_skb); 1496 new_skb = skb; 1497 } else { 1498 /* 1499 * (len < 0) 1500 * MPPE requires that we do not send unencrypted 1501 * frames. The compressor will return -1 if we 1502 * should drop the frame. We cannot simply test 1503 * the compress_proto because MPPE and MPPC share 1504 * the same number. 1505 */ 1506 if (net_ratelimit()) 1507 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n"); 1508 kfree_skb(skb); 1509 consume_skb(new_skb); 1510 new_skb = NULL; 1511 } 1512 return new_skb; 1513 } 1514 1515 /* 1516 * Compress and send a frame. 1517 * The caller should have locked the xmit path, 1518 * and xmit_pending should be 0. 1519 */ 1520 static void 1521 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) 1522 { 1523 int proto = PPP_PROTO(skb); 1524 struct sk_buff *new_skb; 1525 int len; 1526 unsigned char *cp; 1527 1528 if (proto < 0x8000) { 1529 #ifdef CONFIG_PPP_FILTER 1530 /* check if we should pass this packet */ 1531 /* the filter instructions are constructed assuming 1532 a four-byte PPP header on each packet */ 1533 *(u8 *)skb_push(skb, 2) = 1; 1534 if (ppp->pass_filter && 1535 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 1536 if (ppp->debug & 1) 1537 netdev_printk(KERN_DEBUG, ppp->dev, 1538 "PPP: outbound frame " 1539 "not passed\n"); 1540 kfree_skb(skb); 1541 return; 1542 } 1543 /* if this packet passes the active filter, record the time */ 1544 if (!(ppp->active_filter && 1545 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 1546 ppp->last_xmit = jiffies; 1547 skb_pull(skb, 2); 1548 #else 1549 /* for data packets, record the time */ 1550 ppp->last_xmit = jiffies; 1551 #endif /* CONFIG_PPP_FILTER */ 1552 } 1553 1554 ++ppp->stats64.tx_packets; 1555 ppp->stats64.tx_bytes += skb->len - 2; 1556 1557 switch (proto) { 1558 case PPP_IP: 1559 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0) 1560 break; 1561 /* try to do VJ TCP header compression */ 1562 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2, 1563 GFP_ATOMIC); 1564 if (!new_skb) { 1565 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n"); 1566 goto drop; 1567 } 1568 skb_reserve(new_skb, ppp->dev->hard_header_len - 2); 1569 cp = skb->data + 2; 1570 len = slhc_compress(ppp->vj, cp, skb->len - 2, 1571 new_skb->data + 2, &cp, 1572 !(ppp->flags & SC_NO_TCP_CCID)); 1573 if (cp == skb->data + 2) { 1574 /* didn't compress */ 1575 consume_skb(new_skb); 1576 } else { 1577 if (cp[0] & SL_TYPE_COMPRESSED_TCP) { 1578 proto = PPP_VJC_COMP; 1579 cp[0] &= ~SL_TYPE_COMPRESSED_TCP; 1580 } else { 1581 proto = PPP_VJC_UNCOMP; 1582 cp[0] = skb->data[2]; 1583 } 1584 consume_skb(skb); 1585 skb = new_skb; 1586 cp = skb_put(skb, len + 2); 1587 cp[0] = 0; 1588 cp[1] = proto; 1589 } 1590 break; 1591 1592 case PPP_CCP: 1593 /* peek at outbound CCP frames */ 1594 ppp_ccp_peek(ppp, skb, 0); 1595 break; 1596 } 1597 1598 /* try to do packet compression */ 1599 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state && 1600 proto != PPP_LCP && proto != PPP_CCP) { 1601 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) { 1602 if (net_ratelimit()) 1603 netdev_err(ppp->dev, 1604 "ppp: compression required but " 1605 "down - pkt dropped.\n"); 1606 goto drop; 1607 } 1608 skb = pad_compress_skb(ppp, skb); 1609 if (!skb) 1610 goto drop; 1611 } 1612 1613 /* 1614 * If we are waiting for traffic (demand dialling), 1615 * queue it up for pppd to receive. 1616 */ 1617 if (ppp->flags & SC_LOOP_TRAFFIC) { 1618 if (ppp->file.rq.qlen > PPP_MAX_RQLEN) 1619 goto drop; 1620 skb_queue_tail(&ppp->file.rq, skb); 1621 wake_up_interruptible(&ppp->file.rwait); 1622 return; 1623 } 1624 1625 ppp->xmit_pending = skb; 1626 ppp_push(ppp); 1627 return; 1628 1629 drop: 1630 kfree_skb(skb); 1631 ++ppp->dev->stats.tx_errors; 1632 } 1633 1634 /* 1635 * Try to send the frame in xmit_pending. 1636 * The caller should have the xmit path locked. 1637 */ 1638 static void 1639 ppp_push(struct ppp *ppp) 1640 { 1641 struct list_head *list; 1642 struct channel *pch; 1643 struct sk_buff *skb = ppp->xmit_pending; 1644 1645 if (!skb) 1646 return; 1647 1648 list = &ppp->channels; 1649 if (list_empty(list)) { 1650 /* nowhere to send the packet, just drop it */ 1651 ppp->xmit_pending = NULL; 1652 kfree_skb(skb); 1653 return; 1654 } 1655 1656 if ((ppp->flags & SC_MULTILINK) == 0) { 1657 /* not doing multilink: send it down the first channel */ 1658 list = list->next; 1659 pch = list_entry(list, struct channel, clist); 1660 1661 spin_lock(&pch->downl); 1662 if (pch->chan) { 1663 if (pch->chan->ops->start_xmit(pch->chan, skb)) 1664 ppp->xmit_pending = NULL; 1665 } else { 1666 /* channel got unregistered */ 1667 kfree_skb(skb); 1668 ppp->xmit_pending = NULL; 1669 } 1670 spin_unlock(&pch->downl); 1671 return; 1672 } 1673 1674 #ifdef CONFIG_PPP_MULTILINK 1675 /* Multilink: fragment the packet over as many links 1676 as can take the packet at the moment. */ 1677 if (!ppp_mp_explode(ppp, skb)) 1678 return; 1679 #endif /* CONFIG_PPP_MULTILINK */ 1680 1681 ppp->xmit_pending = NULL; 1682 kfree_skb(skb); 1683 } 1684 1685 #ifdef CONFIG_PPP_MULTILINK 1686 static bool mp_protocol_compress __read_mostly = true; 1687 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR); 1688 MODULE_PARM_DESC(mp_protocol_compress, 1689 "compress protocol id in multilink fragments"); 1690 1691 /* 1692 * Divide a packet to be transmitted into fragments and 1693 * send them out the individual links. 1694 */ 1695 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb) 1696 { 1697 int len, totlen; 1698 int i, bits, hdrlen, mtu; 1699 int flen; 1700 int navail, nfree, nzero; 1701 int nbigger; 1702 int totspeed; 1703 int totfree; 1704 unsigned char *p, *q; 1705 struct list_head *list; 1706 struct channel *pch; 1707 struct sk_buff *frag; 1708 struct ppp_channel *chan; 1709 1710 totspeed = 0; /*total bitrate of the bundle*/ 1711 nfree = 0; /* # channels which have no packet already queued */ 1712 navail = 0; /* total # of usable channels (not deregistered) */ 1713 nzero = 0; /* number of channels with zero speed associated*/ 1714 totfree = 0; /*total # of channels available and 1715 *having no queued packets before 1716 *starting the fragmentation*/ 1717 1718 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1719 i = 0; 1720 list_for_each_entry(pch, &ppp->channels, clist) { 1721 if (pch->chan) { 1722 pch->avail = 1; 1723 navail++; 1724 pch->speed = pch->chan->speed; 1725 } else { 1726 pch->avail = 0; 1727 } 1728 if (pch->avail) { 1729 if (skb_queue_empty(&pch->file.xq) || 1730 !pch->had_frag) { 1731 if (pch->speed == 0) 1732 nzero++; 1733 else 1734 totspeed += pch->speed; 1735 1736 pch->avail = 2; 1737 ++nfree; 1738 ++totfree; 1739 } 1740 if (!pch->had_frag && i < ppp->nxchan) 1741 ppp->nxchan = i; 1742 } 1743 ++i; 1744 } 1745 /* 1746 * Don't start sending this packet unless at least half of 1747 * the channels are free. This gives much better TCP 1748 * performance if we have a lot of channels. 1749 */ 1750 if (nfree == 0 || nfree < navail / 2) 1751 return 0; /* can't take now, leave it in xmit_pending */ 1752 1753 /* Do protocol field compression */ 1754 p = skb->data; 1755 len = skb->len; 1756 if (*p == 0 && mp_protocol_compress) { 1757 ++p; 1758 --len; 1759 } 1760 1761 totlen = len; 1762 nbigger = len % nfree; 1763 1764 /* skip to the channel after the one we last used 1765 and start at that one */ 1766 list = &ppp->channels; 1767 for (i = 0; i < ppp->nxchan; ++i) { 1768 list = list->next; 1769 if (list == &ppp->channels) { 1770 i = 0; 1771 break; 1772 } 1773 } 1774 1775 /* create a fragment for each channel */ 1776 bits = B; 1777 while (len > 0) { 1778 list = list->next; 1779 if (list == &ppp->channels) { 1780 i = 0; 1781 continue; 1782 } 1783 pch = list_entry(list, struct channel, clist); 1784 ++i; 1785 if (!pch->avail) 1786 continue; 1787 1788 /* 1789 * Skip this channel if it has a fragment pending already and 1790 * we haven't given a fragment to all of the free channels. 1791 */ 1792 if (pch->avail == 1) { 1793 if (nfree > 0) 1794 continue; 1795 } else { 1796 pch->avail = 1; 1797 } 1798 1799 /* check the channel's mtu and whether it is still attached. */ 1800 spin_lock(&pch->downl); 1801 if (pch->chan == NULL) { 1802 /* can't use this channel, it's being deregistered */ 1803 if (pch->speed == 0) 1804 nzero--; 1805 else 1806 totspeed -= pch->speed; 1807 1808 spin_unlock(&pch->downl); 1809 pch->avail = 0; 1810 totlen = len; 1811 totfree--; 1812 nfree--; 1813 if (--navail == 0) 1814 break; 1815 continue; 1816 } 1817 1818 /* 1819 *if the channel speed is not set divide 1820 *the packet evenly among the free channels; 1821 *otherwise divide it according to the speed 1822 *of the channel we are going to transmit on 1823 */ 1824 flen = len; 1825 if (nfree > 0) { 1826 if (pch->speed == 0) { 1827 flen = len/nfree; 1828 if (nbigger > 0) { 1829 flen++; 1830 nbigger--; 1831 } 1832 } else { 1833 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) / 1834 ((totspeed*totfree)/pch->speed)) - hdrlen; 1835 if (nbigger > 0) { 1836 flen += ((totfree - nzero)*pch->speed)/totspeed; 1837 nbigger -= ((totfree - nzero)*pch->speed)/ 1838 totspeed; 1839 } 1840 } 1841 nfree--; 1842 } 1843 1844 /* 1845 *check if we are on the last channel or 1846 *we exceded the length of the data to 1847 *fragment 1848 */ 1849 if ((nfree <= 0) || (flen > len)) 1850 flen = len; 1851 /* 1852 *it is not worth to tx on slow channels: 1853 *in that case from the resulting flen according to the 1854 *above formula will be equal or less than zero. 1855 *Skip the channel in this case 1856 */ 1857 if (flen <= 0) { 1858 pch->avail = 2; 1859 spin_unlock(&pch->downl); 1860 continue; 1861 } 1862 1863 /* 1864 * hdrlen includes the 2-byte PPP protocol field, but the 1865 * MTU counts only the payload excluding the protocol field. 1866 * (RFC1661 Section 2) 1867 */ 1868 mtu = pch->chan->mtu - (hdrlen - 2); 1869 if (mtu < 4) 1870 mtu = 4; 1871 if (flen > mtu) 1872 flen = mtu; 1873 if (flen == len) 1874 bits |= E; 1875 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC); 1876 if (!frag) 1877 goto noskb; 1878 q = skb_put(frag, flen + hdrlen); 1879 1880 /* make the MP header */ 1881 put_unaligned_be16(PPP_MP, q); 1882 if (ppp->flags & SC_MP_XSHORTSEQ) { 1883 q[2] = bits + ((ppp->nxseq >> 8) & 0xf); 1884 q[3] = ppp->nxseq; 1885 } else { 1886 q[2] = bits; 1887 q[3] = ppp->nxseq >> 16; 1888 q[4] = ppp->nxseq >> 8; 1889 q[5] = ppp->nxseq; 1890 } 1891 1892 memcpy(q + hdrlen, p, flen); 1893 1894 /* try to send it down the channel */ 1895 chan = pch->chan; 1896 if (!skb_queue_empty(&pch->file.xq) || 1897 !chan->ops->start_xmit(chan, frag)) 1898 skb_queue_tail(&pch->file.xq, frag); 1899 pch->had_frag = 1; 1900 p += flen; 1901 len -= flen; 1902 ++ppp->nxseq; 1903 bits = 0; 1904 spin_unlock(&pch->downl); 1905 } 1906 ppp->nxchan = i; 1907 1908 return 1; 1909 1910 noskb: 1911 spin_unlock(&pch->downl); 1912 if (ppp->debug & 1) 1913 netdev_err(ppp->dev, "PPP: no memory (fragment)\n"); 1914 ++ppp->dev->stats.tx_errors; 1915 ++ppp->nxseq; 1916 return 1; /* abandon the frame */ 1917 } 1918 #endif /* CONFIG_PPP_MULTILINK */ 1919 1920 /* Try to send data out on a channel */ 1921 static void __ppp_channel_push(struct channel *pch) 1922 { 1923 struct sk_buff *skb; 1924 struct ppp *ppp; 1925 1926 spin_lock(&pch->downl); 1927 if (pch->chan) { 1928 while (!skb_queue_empty(&pch->file.xq)) { 1929 skb = skb_dequeue(&pch->file.xq); 1930 if (!pch->chan->ops->start_xmit(pch->chan, skb)) { 1931 /* put the packet back and try again later */ 1932 skb_queue_head(&pch->file.xq, skb); 1933 break; 1934 } 1935 } 1936 } else { 1937 /* channel got deregistered */ 1938 skb_queue_purge(&pch->file.xq); 1939 } 1940 spin_unlock(&pch->downl); 1941 /* see if there is anything from the attached unit to be sent */ 1942 if (skb_queue_empty(&pch->file.xq)) { 1943 ppp = pch->ppp; 1944 if (ppp) 1945 __ppp_xmit_process(ppp); 1946 } 1947 } 1948 1949 static void ppp_channel_push(struct channel *pch) 1950 { 1951 read_lock_bh(&pch->upl); 1952 if (pch->ppp) { 1953 (*this_cpu_ptr(pch->ppp->xmit_recursion))++; 1954 __ppp_channel_push(pch); 1955 (*this_cpu_ptr(pch->ppp->xmit_recursion))--; 1956 } else { 1957 __ppp_channel_push(pch); 1958 } 1959 read_unlock_bh(&pch->upl); 1960 } 1961 1962 /* 1963 * Receive-side routines. 1964 */ 1965 1966 struct ppp_mp_skb_parm { 1967 u32 sequence; 1968 u8 BEbits; 1969 }; 1970 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb)) 1971 1972 static inline void 1973 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1974 { 1975 ppp_recv_lock(ppp); 1976 if (!ppp->closing) 1977 ppp_receive_frame(ppp, skb, pch); 1978 else 1979 kfree_skb(skb); 1980 ppp_recv_unlock(ppp); 1981 } 1982 1983 void 1984 ppp_input(struct ppp_channel *chan, struct sk_buff *skb) 1985 { 1986 struct channel *pch = chan->ppp; 1987 int proto; 1988 1989 if (!pch) { 1990 kfree_skb(skb); 1991 return; 1992 } 1993 1994 read_lock_bh(&pch->upl); 1995 if (!pskb_may_pull(skb, 2)) { 1996 kfree_skb(skb); 1997 if (pch->ppp) { 1998 ++pch->ppp->dev->stats.rx_length_errors; 1999 ppp_receive_error(pch->ppp); 2000 } 2001 goto done; 2002 } 2003 2004 proto = PPP_PROTO(skb); 2005 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) { 2006 /* put it on the channel queue */ 2007 skb_queue_tail(&pch->file.rq, skb); 2008 /* drop old frames if queue too long */ 2009 while (pch->file.rq.qlen > PPP_MAX_RQLEN && 2010 (skb = skb_dequeue(&pch->file.rq))) 2011 kfree_skb(skb); 2012 wake_up_interruptible(&pch->file.rwait); 2013 } else { 2014 ppp_do_recv(pch->ppp, skb, pch); 2015 } 2016 2017 done: 2018 read_unlock_bh(&pch->upl); 2019 } 2020 2021 /* Put a 0-length skb in the receive queue as an error indication */ 2022 void 2023 ppp_input_error(struct ppp_channel *chan, int code) 2024 { 2025 struct channel *pch = chan->ppp; 2026 struct sk_buff *skb; 2027 2028 if (!pch) 2029 return; 2030 2031 read_lock_bh(&pch->upl); 2032 if (pch->ppp) { 2033 skb = alloc_skb(0, GFP_ATOMIC); 2034 if (skb) { 2035 skb->len = 0; /* probably unnecessary */ 2036 skb->cb[0] = code; 2037 ppp_do_recv(pch->ppp, skb, pch); 2038 } 2039 } 2040 read_unlock_bh(&pch->upl); 2041 } 2042 2043 /* 2044 * We come in here to process a received frame. 2045 * The receive side of the ppp unit is locked. 2046 */ 2047 static void 2048 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2049 { 2050 /* note: a 0-length skb is used as an error indication */ 2051 if (skb->len > 0) { 2052 skb_checksum_complete_unset(skb); 2053 #ifdef CONFIG_PPP_MULTILINK 2054 /* XXX do channel-level decompression here */ 2055 if (PPP_PROTO(skb) == PPP_MP) 2056 ppp_receive_mp_frame(ppp, skb, pch); 2057 else 2058 #endif /* CONFIG_PPP_MULTILINK */ 2059 ppp_receive_nonmp_frame(ppp, skb); 2060 } else { 2061 kfree_skb(skb); 2062 ppp_receive_error(ppp); 2063 } 2064 } 2065 2066 static void 2067 ppp_receive_error(struct ppp *ppp) 2068 { 2069 ++ppp->dev->stats.rx_errors; 2070 if (ppp->vj) 2071 slhc_toss(ppp->vj); 2072 } 2073 2074 static void 2075 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) 2076 { 2077 struct sk_buff *ns; 2078 int proto, len, npi; 2079 2080 /* 2081 * Decompress the frame, if compressed. 2082 * Note that some decompressors need to see uncompressed frames 2083 * that come in as well as compressed frames. 2084 */ 2085 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) && 2086 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0) 2087 skb = ppp_decompress_frame(ppp, skb); 2088 2089 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR) 2090 goto err; 2091 2092 proto = PPP_PROTO(skb); 2093 switch (proto) { 2094 case PPP_VJC_COMP: 2095 /* decompress VJ compressed packets */ 2096 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 2097 goto err; 2098 2099 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) { 2100 /* copy to a new sk_buff with more tailroom */ 2101 ns = dev_alloc_skb(skb->len + 128); 2102 if (!ns) { 2103 netdev_err(ppp->dev, "PPP: no memory " 2104 "(VJ decomp)\n"); 2105 goto err; 2106 } 2107 skb_reserve(ns, 2); 2108 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len); 2109 consume_skb(skb); 2110 skb = ns; 2111 } 2112 else 2113 skb->ip_summed = CHECKSUM_NONE; 2114 2115 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2); 2116 if (len <= 0) { 2117 netdev_printk(KERN_DEBUG, ppp->dev, 2118 "PPP: VJ decompression error\n"); 2119 goto err; 2120 } 2121 len += 2; 2122 if (len > skb->len) 2123 skb_put(skb, len - skb->len); 2124 else if (len < skb->len) 2125 skb_trim(skb, len); 2126 proto = PPP_IP; 2127 break; 2128 2129 case PPP_VJC_UNCOMP: 2130 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 2131 goto err; 2132 2133 /* Until we fix the decompressor need to make sure 2134 * data portion is linear. 2135 */ 2136 if (!pskb_may_pull(skb, skb->len)) 2137 goto err; 2138 2139 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) { 2140 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n"); 2141 goto err; 2142 } 2143 proto = PPP_IP; 2144 break; 2145 2146 case PPP_CCP: 2147 ppp_ccp_peek(ppp, skb, 1); 2148 break; 2149 } 2150 2151 ++ppp->stats64.rx_packets; 2152 ppp->stats64.rx_bytes += skb->len - 2; 2153 2154 npi = proto_to_npindex(proto); 2155 if (npi < 0) { 2156 /* control or unknown frame - pass it to pppd */ 2157 skb_queue_tail(&ppp->file.rq, skb); 2158 /* limit queue length by dropping old frames */ 2159 while (ppp->file.rq.qlen > PPP_MAX_RQLEN && 2160 (skb = skb_dequeue(&ppp->file.rq))) 2161 kfree_skb(skb); 2162 /* wake up any process polling or blocking on read */ 2163 wake_up_interruptible(&ppp->file.rwait); 2164 2165 } else { 2166 /* network protocol frame - give it to the kernel */ 2167 2168 #ifdef CONFIG_PPP_FILTER 2169 /* check if the packet passes the pass and active filters */ 2170 /* the filter instructions are constructed assuming 2171 a four-byte PPP header on each packet */ 2172 if (ppp->pass_filter || ppp->active_filter) { 2173 if (skb_unclone(skb, GFP_ATOMIC)) 2174 goto err; 2175 2176 *(u8 *)skb_push(skb, 2) = 0; 2177 if (ppp->pass_filter && 2178 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 2179 if (ppp->debug & 1) 2180 netdev_printk(KERN_DEBUG, ppp->dev, 2181 "PPP: inbound frame " 2182 "not passed\n"); 2183 kfree_skb(skb); 2184 return; 2185 } 2186 if (!(ppp->active_filter && 2187 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 2188 ppp->last_recv = jiffies; 2189 __skb_pull(skb, 2); 2190 } else 2191 #endif /* CONFIG_PPP_FILTER */ 2192 ppp->last_recv = jiffies; 2193 2194 if ((ppp->dev->flags & IFF_UP) == 0 || 2195 ppp->npmode[npi] != NPMODE_PASS) { 2196 kfree_skb(skb); 2197 } else { 2198 /* chop off protocol */ 2199 skb_pull_rcsum(skb, 2); 2200 skb->dev = ppp->dev; 2201 skb->protocol = htons(npindex_to_ethertype[npi]); 2202 skb_reset_mac_header(skb); 2203 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, 2204 dev_net(ppp->dev))); 2205 netif_rx(skb); 2206 } 2207 } 2208 return; 2209 2210 err: 2211 kfree_skb(skb); 2212 ppp_receive_error(ppp); 2213 } 2214 2215 static struct sk_buff * 2216 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb) 2217 { 2218 int proto = PPP_PROTO(skb); 2219 struct sk_buff *ns; 2220 int len; 2221 2222 /* Until we fix all the decompressor's need to make sure 2223 * data portion is linear. 2224 */ 2225 if (!pskb_may_pull(skb, skb->len)) 2226 goto err; 2227 2228 if (proto == PPP_COMP) { 2229 int obuff_size; 2230 2231 switch(ppp->rcomp->compress_proto) { 2232 case CI_MPPE: 2233 obuff_size = ppp->mru + PPP_HDRLEN + 1; 2234 break; 2235 default: 2236 obuff_size = ppp->mru + PPP_HDRLEN; 2237 break; 2238 } 2239 2240 ns = dev_alloc_skb(obuff_size); 2241 if (!ns) { 2242 netdev_err(ppp->dev, "ppp_decompress_frame: " 2243 "no memory\n"); 2244 goto err; 2245 } 2246 /* the decompressor still expects the A/C bytes in the hdr */ 2247 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2, 2248 skb->len + 2, ns->data, obuff_size); 2249 if (len < 0) { 2250 /* Pass the compressed frame to pppd as an 2251 error indication. */ 2252 if (len == DECOMP_FATALERROR) 2253 ppp->rstate |= SC_DC_FERROR; 2254 kfree_skb(ns); 2255 goto err; 2256 } 2257 2258 consume_skb(skb); 2259 skb = ns; 2260 skb_put(skb, len); 2261 skb_pull(skb, 2); /* pull off the A/C bytes */ 2262 2263 } else { 2264 /* Uncompressed frame - pass to decompressor so it 2265 can update its dictionary if necessary. */ 2266 if (ppp->rcomp->incomp) 2267 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2, 2268 skb->len + 2); 2269 } 2270 2271 return skb; 2272 2273 err: 2274 ppp->rstate |= SC_DC_ERROR; 2275 ppp_receive_error(ppp); 2276 return skb; 2277 } 2278 2279 #ifdef CONFIG_PPP_MULTILINK 2280 /* 2281 * Receive a multilink frame. 2282 * We put it on the reconstruction queue and then pull off 2283 * as many completed frames as we can. 2284 */ 2285 static void 2286 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2287 { 2288 u32 mask, seq; 2289 struct channel *ch; 2290 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 2291 2292 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0) 2293 goto err; /* no good, throw it away */ 2294 2295 /* Decode sequence number and begin/end bits */ 2296 if (ppp->flags & SC_MP_SHORTSEQ) { 2297 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3]; 2298 mask = 0xfff; 2299 } else { 2300 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5]; 2301 mask = 0xffffff; 2302 } 2303 PPP_MP_CB(skb)->BEbits = skb->data[2]; 2304 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */ 2305 2306 /* 2307 * Do protocol ID decompression on the first fragment of each packet. 2308 */ 2309 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1)) 2310 *(u8 *)skb_push(skb, 1) = 0; 2311 2312 /* 2313 * Expand sequence number to 32 bits, making it as close 2314 * as possible to ppp->minseq. 2315 */ 2316 seq |= ppp->minseq & ~mask; 2317 if ((int)(ppp->minseq - seq) > (int)(mask >> 1)) 2318 seq += mask + 1; 2319 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1)) 2320 seq -= mask + 1; /* should never happen */ 2321 PPP_MP_CB(skb)->sequence = seq; 2322 pch->lastseq = seq; 2323 2324 /* 2325 * If this packet comes before the next one we were expecting, 2326 * drop it. 2327 */ 2328 if (seq_before(seq, ppp->nextseq)) { 2329 kfree_skb(skb); 2330 ++ppp->dev->stats.rx_dropped; 2331 ppp_receive_error(ppp); 2332 return; 2333 } 2334 2335 /* 2336 * Reevaluate minseq, the minimum over all channels of the 2337 * last sequence number received on each channel. Because of 2338 * the increasing sequence number rule, we know that any fragment 2339 * before `minseq' which hasn't arrived is never going to arrive. 2340 * The list of channels can't change because we have the receive 2341 * side of the ppp unit locked. 2342 */ 2343 list_for_each_entry(ch, &ppp->channels, clist) { 2344 if (seq_before(ch->lastseq, seq)) 2345 seq = ch->lastseq; 2346 } 2347 if (seq_before(ppp->minseq, seq)) 2348 ppp->minseq = seq; 2349 2350 /* Put the fragment on the reconstruction queue */ 2351 ppp_mp_insert(ppp, skb); 2352 2353 /* If the queue is getting long, don't wait any longer for packets 2354 before the start of the queue. */ 2355 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) { 2356 struct sk_buff *mskb = skb_peek(&ppp->mrq); 2357 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence)) 2358 ppp->minseq = PPP_MP_CB(mskb)->sequence; 2359 } 2360 2361 /* Pull completed packets off the queue and receive them. */ 2362 while ((skb = ppp_mp_reconstruct(ppp))) { 2363 if (pskb_may_pull(skb, 2)) 2364 ppp_receive_nonmp_frame(ppp, skb); 2365 else { 2366 ++ppp->dev->stats.rx_length_errors; 2367 kfree_skb(skb); 2368 ppp_receive_error(ppp); 2369 } 2370 } 2371 2372 return; 2373 2374 err: 2375 kfree_skb(skb); 2376 ppp_receive_error(ppp); 2377 } 2378 2379 /* 2380 * Insert a fragment on the MP reconstruction queue. 2381 * The queue is ordered by increasing sequence number. 2382 */ 2383 static void 2384 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb) 2385 { 2386 struct sk_buff *p; 2387 struct sk_buff_head *list = &ppp->mrq; 2388 u32 seq = PPP_MP_CB(skb)->sequence; 2389 2390 /* N.B. we don't need to lock the list lock because we have the 2391 ppp unit receive-side lock. */ 2392 skb_queue_walk(list, p) { 2393 if (seq_before(seq, PPP_MP_CB(p)->sequence)) 2394 break; 2395 } 2396 __skb_queue_before(list, p, skb); 2397 } 2398 2399 /* 2400 * Reconstruct a packet from the MP fragment queue. 2401 * We go through increasing sequence numbers until we find a 2402 * complete packet, or we get to the sequence number for a fragment 2403 * which hasn't arrived but might still do so. 2404 */ 2405 static struct sk_buff * 2406 ppp_mp_reconstruct(struct ppp *ppp) 2407 { 2408 u32 seq = ppp->nextseq; 2409 u32 minseq = ppp->minseq; 2410 struct sk_buff_head *list = &ppp->mrq; 2411 struct sk_buff *p, *tmp; 2412 struct sk_buff *head, *tail; 2413 struct sk_buff *skb = NULL; 2414 int lost = 0, len = 0; 2415 2416 if (ppp->mrru == 0) /* do nothing until mrru is set */ 2417 return NULL; 2418 head = list->next; 2419 tail = NULL; 2420 skb_queue_walk_safe(list, p, tmp) { 2421 again: 2422 if (seq_before(PPP_MP_CB(p)->sequence, seq)) { 2423 /* this can't happen, anyway ignore the skb */ 2424 netdev_err(ppp->dev, "ppp_mp_reconstruct bad " 2425 "seq %u < %u\n", 2426 PPP_MP_CB(p)->sequence, seq); 2427 __skb_unlink(p, list); 2428 kfree_skb(p); 2429 continue; 2430 } 2431 if (PPP_MP_CB(p)->sequence != seq) { 2432 u32 oldseq; 2433 /* Fragment `seq' is missing. If it is after 2434 minseq, it might arrive later, so stop here. */ 2435 if (seq_after(seq, minseq)) 2436 break; 2437 /* Fragment `seq' is lost, keep going. */ 2438 lost = 1; 2439 oldseq = seq; 2440 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)? 2441 minseq + 1: PPP_MP_CB(p)->sequence; 2442 2443 if (ppp->debug & 1) 2444 netdev_printk(KERN_DEBUG, ppp->dev, 2445 "lost frag %u..%u\n", 2446 oldseq, seq-1); 2447 2448 goto again; 2449 } 2450 2451 /* 2452 * At this point we know that all the fragments from 2453 * ppp->nextseq to seq are either present or lost. 2454 * Also, there are no complete packets in the queue 2455 * that have no missing fragments and end before this 2456 * fragment. 2457 */ 2458 2459 /* B bit set indicates this fragment starts a packet */ 2460 if (PPP_MP_CB(p)->BEbits & B) { 2461 head = p; 2462 lost = 0; 2463 len = 0; 2464 } 2465 2466 len += p->len; 2467 2468 /* Got a complete packet yet? */ 2469 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) && 2470 (PPP_MP_CB(head)->BEbits & B)) { 2471 if (len > ppp->mrru + 2) { 2472 ++ppp->dev->stats.rx_length_errors; 2473 netdev_printk(KERN_DEBUG, ppp->dev, 2474 "PPP: reconstructed packet" 2475 " is too long (%d)\n", len); 2476 } else { 2477 tail = p; 2478 break; 2479 } 2480 ppp->nextseq = seq + 1; 2481 } 2482 2483 /* 2484 * If this is the ending fragment of a packet, 2485 * and we haven't found a complete valid packet yet, 2486 * we can discard up to and including this fragment. 2487 */ 2488 if (PPP_MP_CB(p)->BEbits & E) { 2489 struct sk_buff *tmp2; 2490 2491 skb_queue_reverse_walk_from_safe(list, p, tmp2) { 2492 if (ppp->debug & 1) 2493 netdev_printk(KERN_DEBUG, ppp->dev, 2494 "discarding frag %u\n", 2495 PPP_MP_CB(p)->sequence); 2496 __skb_unlink(p, list); 2497 kfree_skb(p); 2498 } 2499 head = skb_peek(list); 2500 if (!head) 2501 break; 2502 } 2503 ++seq; 2504 } 2505 2506 /* If we have a complete packet, copy it all into one skb. */ 2507 if (tail != NULL) { 2508 /* If we have discarded any fragments, 2509 signal a receive error. */ 2510 if (PPP_MP_CB(head)->sequence != ppp->nextseq) { 2511 skb_queue_walk_safe(list, p, tmp) { 2512 if (p == head) 2513 break; 2514 if (ppp->debug & 1) 2515 netdev_printk(KERN_DEBUG, ppp->dev, 2516 "discarding frag %u\n", 2517 PPP_MP_CB(p)->sequence); 2518 __skb_unlink(p, list); 2519 kfree_skb(p); 2520 } 2521 2522 if (ppp->debug & 1) 2523 netdev_printk(KERN_DEBUG, ppp->dev, 2524 " missed pkts %u..%u\n", 2525 ppp->nextseq, 2526 PPP_MP_CB(head)->sequence-1); 2527 ++ppp->dev->stats.rx_dropped; 2528 ppp_receive_error(ppp); 2529 } 2530 2531 skb = head; 2532 if (head != tail) { 2533 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list; 2534 p = skb_queue_next(list, head); 2535 __skb_unlink(skb, list); 2536 skb_queue_walk_from_safe(list, p, tmp) { 2537 __skb_unlink(p, list); 2538 *fragpp = p; 2539 p->next = NULL; 2540 fragpp = &p->next; 2541 2542 skb->len += p->len; 2543 skb->data_len += p->len; 2544 skb->truesize += p->truesize; 2545 2546 if (p == tail) 2547 break; 2548 } 2549 } else { 2550 __skb_unlink(skb, list); 2551 } 2552 2553 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1; 2554 } 2555 2556 return skb; 2557 } 2558 #endif /* CONFIG_PPP_MULTILINK */ 2559 2560 /* 2561 * Channel interface. 2562 */ 2563 2564 /* Create a new, unattached ppp channel. */ 2565 int ppp_register_channel(struct ppp_channel *chan) 2566 { 2567 return ppp_register_net_channel(current->nsproxy->net_ns, chan); 2568 } 2569 2570 /* Create a new, unattached ppp channel for specified net. */ 2571 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan) 2572 { 2573 struct channel *pch; 2574 struct ppp_net *pn; 2575 2576 pch = kzalloc(sizeof(struct channel), GFP_KERNEL); 2577 if (!pch) 2578 return -ENOMEM; 2579 2580 pn = ppp_pernet(net); 2581 2582 pch->ppp = NULL; 2583 pch->chan = chan; 2584 pch->chan_net = get_net(net); 2585 chan->ppp = pch; 2586 init_ppp_file(&pch->file, CHANNEL); 2587 pch->file.hdrlen = chan->hdrlen; 2588 #ifdef CONFIG_PPP_MULTILINK 2589 pch->lastseq = -1; 2590 #endif /* CONFIG_PPP_MULTILINK */ 2591 init_rwsem(&pch->chan_sem); 2592 spin_lock_init(&pch->downl); 2593 rwlock_init(&pch->upl); 2594 2595 spin_lock_bh(&pn->all_channels_lock); 2596 pch->file.index = ++pn->last_channel_index; 2597 list_add(&pch->list, &pn->new_channels); 2598 atomic_inc(&channel_count); 2599 spin_unlock_bh(&pn->all_channels_lock); 2600 2601 return 0; 2602 } 2603 2604 /* 2605 * Return the index of a channel. 2606 */ 2607 int ppp_channel_index(struct ppp_channel *chan) 2608 { 2609 struct channel *pch = chan->ppp; 2610 2611 if (pch) 2612 return pch->file.index; 2613 return -1; 2614 } 2615 2616 /* 2617 * Return the PPP unit number to which a channel is connected. 2618 */ 2619 int ppp_unit_number(struct ppp_channel *chan) 2620 { 2621 struct channel *pch = chan->ppp; 2622 int unit = -1; 2623 2624 if (pch) { 2625 read_lock_bh(&pch->upl); 2626 if (pch->ppp) 2627 unit = pch->ppp->file.index; 2628 read_unlock_bh(&pch->upl); 2629 } 2630 return unit; 2631 } 2632 2633 /* 2634 * Return the PPP device interface name of a channel. 2635 */ 2636 char *ppp_dev_name(struct ppp_channel *chan) 2637 { 2638 struct channel *pch = chan->ppp; 2639 char *name = NULL; 2640 2641 if (pch) { 2642 read_lock_bh(&pch->upl); 2643 if (pch->ppp && pch->ppp->dev) 2644 name = pch->ppp->dev->name; 2645 read_unlock_bh(&pch->upl); 2646 } 2647 return name; 2648 } 2649 2650 2651 /* 2652 * Disconnect a channel from the generic layer. 2653 * This must be called in process context. 2654 */ 2655 void 2656 ppp_unregister_channel(struct ppp_channel *chan) 2657 { 2658 struct channel *pch = chan->ppp; 2659 struct ppp_net *pn; 2660 2661 if (!pch) 2662 return; /* should never happen */ 2663 2664 chan->ppp = NULL; 2665 2666 /* 2667 * This ensures that we have returned from any calls into the 2668 * the channel's start_xmit or ioctl routine before we proceed. 2669 */ 2670 down_write(&pch->chan_sem); 2671 spin_lock_bh(&pch->downl); 2672 pch->chan = NULL; 2673 spin_unlock_bh(&pch->downl); 2674 up_write(&pch->chan_sem); 2675 ppp_disconnect_channel(pch); 2676 2677 pn = ppp_pernet(pch->chan_net); 2678 spin_lock_bh(&pn->all_channels_lock); 2679 list_del(&pch->list); 2680 spin_unlock_bh(&pn->all_channels_lock); 2681 2682 pch->file.dead = 1; 2683 wake_up_interruptible(&pch->file.rwait); 2684 if (refcount_dec_and_test(&pch->file.refcnt)) 2685 ppp_destroy_channel(pch); 2686 } 2687 2688 /* 2689 * Callback from a channel when it can accept more to transmit. 2690 * This should be called at BH/softirq level, not interrupt level. 2691 */ 2692 void 2693 ppp_output_wakeup(struct ppp_channel *chan) 2694 { 2695 struct channel *pch = chan->ppp; 2696 2697 if (!pch) 2698 return; 2699 ppp_channel_push(pch); 2700 } 2701 2702 /* 2703 * Compression control. 2704 */ 2705 2706 /* Process the PPPIOCSCOMPRESS ioctl. */ 2707 static int 2708 ppp_set_compress(struct ppp *ppp, unsigned long arg) 2709 { 2710 int err; 2711 struct compressor *cp, *ocomp; 2712 struct ppp_option_data data; 2713 void *state, *ostate; 2714 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH]; 2715 2716 err = -EFAULT; 2717 if (copy_from_user(&data, (void __user *) arg, sizeof(data))) 2718 goto out; 2719 if (data.length > CCP_MAX_OPTION_LENGTH) 2720 goto out; 2721 if (copy_from_user(ccp_option, (void __user *) data.ptr, data.length)) 2722 goto out; 2723 2724 err = -EINVAL; 2725 if (data.length < 2 || ccp_option[1] < 2 || ccp_option[1] > data.length) 2726 goto out; 2727 2728 cp = try_then_request_module( 2729 find_compressor(ccp_option[0]), 2730 "ppp-compress-%d", ccp_option[0]); 2731 if (!cp) 2732 goto out; 2733 2734 err = -ENOBUFS; 2735 if (data.transmit) { 2736 state = cp->comp_alloc(ccp_option, data.length); 2737 if (state) { 2738 ppp_xmit_lock(ppp); 2739 ppp->xstate &= ~SC_COMP_RUN; 2740 ocomp = ppp->xcomp; 2741 ostate = ppp->xc_state; 2742 ppp->xcomp = cp; 2743 ppp->xc_state = state; 2744 ppp_xmit_unlock(ppp); 2745 if (ostate) { 2746 ocomp->comp_free(ostate); 2747 module_put(ocomp->owner); 2748 } 2749 err = 0; 2750 } else 2751 module_put(cp->owner); 2752 2753 } else { 2754 state = cp->decomp_alloc(ccp_option, data.length); 2755 if (state) { 2756 ppp_recv_lock(ppp); 2757 ppp->rstate &= ~SC_DECOMP_RUN; 2758 ocomp = ppp->rcomp; 2759 ostate = ppp->rc_state; 2760 ppp->rcomp = cp; 2761 ppp->rc_state = state; 2762 ppp_recv_unlock(ppp); 2763 if (ostate) { 2764 ocomp->decomp_free(ostate); 2765 module_put(ocomp->owner); 2766 } 2767 err = 0; 2768 } else 2769 module_put(cp->owner); 2770 } 2771 2772 out: 2773 return err; 2774 } 2775 2776 /* 2777 * Look at a CCP packet and update our state accordingly. 2778 * We assume the caller has the xmit or recv path locked. 2779 */ 2780 static void 2781 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound) 2782 { 2783 unsigned char *dp; 2784 int len; 2785 2786 if (!pskb_may_pull(skb, CCP_HDRLEN + 2)) 2787 return; /* no header */ 2788 dp = skb->data + 2; 2789 2790 switch (CCP_CODE(dp)) { 2791 case CCP_CONFREQ: 2792 2793 /* A ConfReq starts negotiation of compression 2794 * in one direction of transmission, 2795 * and hence brings it down...but which way? 2796 * 2797 * Remember: 2798 * A ConfReq indicates what the sender would like to receive 2799 */ 2800 if(inbound) 2801 /* He is proposing what I should send */ 2802 ppp->xstate &= ~SC_COMP_RUN; 2803 else 2804 /* I am proposing to what he should send */ 2805 ppp->rstate &= ~SC_DECOMP_RUN; 2806 2807 break; 2808 2809 case CCP_TERMREQ: 2810 case CCP_TERMACK: 2811 /* 2812 * CCP is going down, both directions of transmission 2813 */ 2814 ppp->rstate &= ~SC_DECOMP_RUN; 2815 ppp->xstate &= ~SC_COMP_RUN; 2816 break; 2817 2818 case CCP_CONFACK: 2819 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN) 2820 break; 2821 len = CCP_LENGTH(dp); 2822 if (!pskb_may_pull(skb, len + 2)) 2823 return; /* too short */ 2824 dp += CCP_HDRLEN; 2825 len -= CCP_HDRLEN; 2826 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp)) 2827 break; 2828 if (inbound) { 2829 /* we will start receiving compressed packets */ 2830 if (!ppp->rc_state) 2831 break; 2832 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len, 2833 ppp->file.index, 0, ppp->mru, ppp->debug)) { 2834 ppp->rstate |= SC_DECOMP_RUN; 2835 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR); 2836 } 2837 } else { 2838 /* we will soon start sending compressed packets */ 2839 if (!ppp->xc_state) 2840 break; 2841 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len, 2842 ppp->file.index, 0, ppp->debug)) 2843 ppp->xstate |= SC_COMP_RUN; 2844 } 2845 break; 2846 2847 case CCP_RESETACK: 2848 /* reset the [de]compressor */ 2849 if ((ppp->flags & SC_CCP_UP) == 0) 2850 break; 2851 if (inbound) { 2852 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) { 2853 ppp->rcomp->decomp_reset(ppp->rc_state); 2854 ppp->rstate &= ~SC_DC_ERROR; 2855 } 2856 } else { 2857 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN)) 2858 ppp->xcomp->comp_reset(ppp->xc_state); 2859 } 2860 break; 2861 } 2862 } 2863 2864 /* Free up compression resources. */ 2865 static void 2866 ppp_ccp_closed(struct ppp *ppp) 2867 { 2868 void *xstate, *rstate; 2869 struct compressor *xcomp, *rcomp; 2870 2871 ppp_lock(ppp); 2872 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP); 2873 ppp->xstate = 0; 2874 xcomp = ppp->xcomp; 2875 xstate = ppp->xc_state; 2876 ppp->xc_state = NULL; 2877 ppp->rstate = 0; 2878 rcomp = ppp->rcomp; 2879 rstate = ppp->rc_state; 2880 ppp->rc_state = NULL; 2881 ppp_unlock(ppp); 2882 2883 if (xstate) { 2884 xcomp->comp_free(xstate); 2885 module_put(xcomp->owner); 2886 } 2887 if (rstate) { 2888 rcomp->decomp_free(rstate); 2889 module_put(rcomp->owner); 2890 } 2891 } 2892 2893 /* List of compressors. */ 2894 static LIST_HEAD(compressor_list); 2895 static DEFINE_SPINLOCK(compressor_list_lock); 2896 2897 struct compressor_entry { 2898 struct list_head list; 2899 struct compressor *comp; 2900 }; 2901 2902 static struct compressor_entry * 2903 find_comp_entry(int proto) 2904 { 2905 struct compressor_entry *ce; 2906 2907 list_for_each_entry(ce, &compressor_list, list) { 2908 if (ce->comp->compress_proto == proto) 2909 return ce; 2910 } 2911 return NULL; 2912 } 2913 2914 /* Register a compressor */ 2915 int 2916 ppp_register_compressor(struct compressor *cp) 2917 { 2918 struct compressor_entry *ce; 2919 int ret; 2920 spin_lock(&compressor_list_lock); 2921 ret = -EEXIST; 2922 if (find_comp_entry(cp->compress_proto)) 2923 goto out; 2924 ret = -ENOMEM; 2925 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC); 2926 if (!ce) 2927 goto out; 2928 ret = 0; 2929 ce->comp = cp; 2930 list_add(&ce->list, &compressor_list); 2931 out: 2932 spin_unlock(&compressor_list_lock); 2933 return ret; 2934 } 2935 2936 /* Unregister a compressor */ 2937 void 2938 ppp_unregister_compressor(struct compressor *cp) 2939 { 2940 struct compressor_entry *ce; 2941 2942 spin_lock(&compressor_list_lock); 2943 ce = find_comp_entry(cp->compress_proto); 2944 if (ce && ce->comp == cp) { 2945 list_del(&ce->list); 2946 kfree(ce); 2947 } 2948 spin_unlock(&compressor_list_lock); 2949 } 2950 2951 /* Find a compressor. */ 2952 static struct compressor * 2953 find_compressor(int type) 2954 { 2955 struct compressor_entry *ce; 2956 struct compressor *cp = NULL; 2957 2958 spin_lock(&compressor_list_lock); 2959 ce = find_comp_entry(type); 2960 if (ce) { 2961 cp = ce->comp; 2962 if (!try_module_get(cp->owner)) 2963 cp = NULL; 2964 } 2965 spin_unlock(&compressor_list_lock); 2966 return cp; 2967 } 2968 2969 /* 2970 * Miscelleneous stuff. 2971 */ 2972 2973 static void 2974 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st) 2975 { 2976 struct slcompress *vj = ppp->vj; 2977 2978 memset(st, 0, sizeof(*st)); 2979 st->p.ppp_ipackets = ppp->stats64.rx_packets; 2980 st->p.ppp_ierrors = ppp->dev->stats.rx_errors; 2981 st->p.ppp_ibytes = ppp->stats64.rx_bytes; 2982 st->p.ppp_opackets = ppp->stats64.tx_packets; 2983 st->p.ppp_oerrors = ppp->dev->stats.tx_errors; 2984 st->p.ppp_obytes = ppp->stats64.tx_bytes; 2985 if (!vj) 2986 return; 2987 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed; 2988 st->vj.vjs_compressed = vj->sls_o_compressed; 2989 st->vj.vjs_searches = vj->sls_o_searches; 2990 st->vj.vjs_misses = vj->sls_o_misses; 2991 st->vj.vjs_errorin = vj->sls_i_error; 2992 st->vj.vjs_tossed = vj->sls_i_tossed; 2993 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed; 2994 st->vj.vjs_compressedin = vj->sls_i_compressed; 2995 } 2996 2997 /* 2998 * Stuff for handling the lists of ppp units and channels 2999 * and for initialization. 3000 */ 3001 3002 /* 3003 * Create a new ppp interface unit. Fails if it can't allocate memory 3004 * or if there is already a unit with the requested number. 3005 * unit == -1 means allocate a new number. 3006 */ 3007 static int ppp_create_interface(struct net *net, struct file *file, int *unit) 3008 { 3009 struct ppp_config conf = { 3010 .file = file, 3011 .unit = *unit, 3012 .ifname_is_set = false, 3013 }; 3014 struct net_device *dev; 3015 struct ppp *ppp; 3016 int err; 3017 3018 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup); 3019 if (!dev) { 3020 err = -ENOMEM; 3021 goto err; 3022 } 3023 dev_net_set(dev, net); 3024 dev->rtnl_link_ops = &ppp_link_ops; 3025 3026 rtnl_lock(); 3027 3028 err = ppp_dev_configure(net, dev, &conf); 3029 if (err < 0) 3030 goto err_dev; 3031 ppp = netdev_priv(dev); 3032 *unit = ppp->file.index; 3033 3034 rtnl_unlock(); 3035 3036 return 0; 3037 3038 err_dev: 3039 rtnl_unlock(); 3040 free_netdev(dev); 3041 err: 3042 return err; 3043 } 3044 3045 /* 3046 * Initialize a ppp_file structure. 3047 */ 3048 static void 3049 init_ppp_file(struct ppp_file *pf, int kind) 3050 { 3051 pf->kind = kind; 3052 skb_queue_head_init(&pf->xq); 3053 skb_queue_head_init(&pf->rq); 3054 refcount_set(&pf->refcnt, 1); 3055 init_waitqueue_head(&pf->rwait); 3056 } 3057 3058 /* 3059 * Free the memory used by a ppp unit. This is only called once 3060 * there are no channels connected to the unit and no file structs 3061 * that reference the unit. 3062 */ 3063 static void ppp_destroy_interface(struct ppp *ppp) 3064 { 3065 atomic_dec(&ppp_unit_count); 3066 3067 if (!ppp->file.dead || ppp->n_channels) { 3068 /* "can't happen" */ 3069 netdev_err(ppp->dev, "ppp: destroying ppp struct %p " 3070 "but dead=%d n_channels=%d !\n", 3071 ppp, ppp->file.dead, ppp->n_channels); 3072 return; 3073 } 3074 3075 ppp_ccp_closed(ppp); 3076 if (ppp->vj) { 3077 slhc_free(ppp->vj); 3078 ppp->vj = NULL; 3079 } 3080 skb_queue_purge(&ppp->file.xq); 3081 skb_queue_purge(&ppp->file.rq); 3082 #ifdef CONFIG_PPP_MULTILINK 3083 skb_queue_purge(&ppp->mrq); 3084 #endif /* CONFIG_PPP_MULTILINK */ 3085 #ifdef CONFIG_PPP_FILTER 3086 if (ppp->pass_filter) { 3087 bpf_prog_destroy(ppp->pass_filter); 3088 ppp->pass_filter = NULL; 3089 } 3090 3091 if (ppp->active_filter) { 3092 bpf_prog_destroy(ppp->active_filter); 3093 ppp->active_filter = NULL; 3094 } 3095 #endif /* CONFIG_PPP_FILTER */ 3096 3097 kfree_skb(ppp->xmit_pending); 3098 free_percpu(ppp->xmit_recursion); 3099 3100 free_netdev(ppp->dev); 3101 } 3102 3103 /* 3104 * Locate an existing ppp unit. 3105 * The caller should have locked the all_ppp_mutex. 3106 */ 3107 static struct ppp * 3108 ppp_find_unit(struct ppp_net *pn, int unit) 3109 { 3110 return unit_find(&pn->units_idr, unit); 3111 } 3112 3113 /* 3114 * Locate an existing ppp channel. 3115 * The caller should have locked the all_channels_lock. 3116 * First we look in the new_channels list, then in the 3117 * all_channels list. If found in the new_channels list, 3118 * we move it to the all_channels list. This is for speed 3119 * when we have a lot of channels in use. 3120 */ 3121 static struct channel * 3122 ppp_find_channel(struct ppp_net *pn, int unit) 3123 { 3124 struct channel *pch; 3125 3126 list_for_each_entry(pch, &pn->new_channels, list) { 3127 if (pch->file.index == unit) { 3128 list_move(&pch->list, &pn->all_channels); 3129 return pch; 3130 } 3131 } 3132 3133 list_for_each_entry(pch, &pn->all_channels, list) { 3134 if (pch->file.index == unit) 3135 return pch; 3136 } 3137 3138 return NULL; 3139 } 3140 3141 /* 3142 * Connect a PPP channel to a PPP interface unit. 3143 */ 3144 static int 3145 ppp_connect_channel(struct channel *pch, int unit) 3146 { 3147 struct ppp *ppp; 3148 struct ppp_net *pn; 3149 int ret = -ENXIO; 3150 int hdrlen; 3151 3152 pn = ppp_pernet(pch->chan_net); 3153 3154 mutex_lock(&pn->all_ppp_mutex); 3155 ppp = ppp_find_unit(pn, unit); 3156 if (!ppp) 3157 goto out; 3158 write_lock_bh(&pch->upl); 3159 ret = -EINVAL; 3160 if (pch->ppp) 3161 goto outl; 3162 3163 ppp_lock(ppp); 3164 if (pch->file.hdrlen > ppp->file.hdrlen) 3165 ppp->file.hdrlen = pch->file.hdrlen; 3166 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */ 3167 if (hdrlen > ppp->dev->hard_header_len) 3168 ppp->dev->hard_header_len = hdrlen; 3169 list_add_tail(&pch->clist, &ppp->channels); 3170 ++ppp->n_channels; 3171 pch->ppp = ppp; 3172 refcount_inc(&ppp->file.refcnt); 3173 ppp_unlock(ppp); 3174 ret = 0; 3175 3176 outl: 3177 write_unlock_bh(&pch->upl); 3178 out: 3179 mutex_unlock(&pn->all_ppp_mutex); 3180 return ret; 3181 } 3182 3183 /* 3184 * Disconnect a channel from its ppp unit. 3185 */ 3186 static int 3187 ppp_disconnect_channel(struct channel *pch) 3188 { 3189 struct ppp *ppp; 3190 int err = -EINVAL; 3191 3192 write_lock_bh(&pch->upl); 3193 ppp = pch->ppp; 3194 pch->ppp = NULL; 3195 write_unlock_bh(&pch->upl); 3196 if (ppp) { 3197 /* remove it from the ppp unit's list */ 3198 ppp_lock(ppp); 3199 list_del(&pch->clist); 3200 if (--ppp->n_channels == 0) 3201 wake_up_interruptible(&ppp->file.rwait); 3202 ppp_unlock(ppp); 3203 if (refcount_dec_and_test(&ppp->file.refcnt)) 3204 ppp_destroy_interface(ppp); 3205 err = 0; 3206 } 3207 return err; 3208 } 3209 3210 /* 3211 * Free up the resources used by a ppp channel. 3212 */ 3213 static void ppp_destroy_channel(struct channel *pch) 3214 { 3215 put_net(pch->chan_net); 3216 pch->chan_net = NULL; 3217 3218 atomic_dec(&channel_count); 3219 3220 if (!pch->file.dead) { 3221 /* "can't happen" */ 3222 pr_err("ppp: destroying undead channel %p !\n", pch); 3223 return; 3224 } 3225 skb_queue_purge(&pch->file.xq); 3226 skb_queue_purge(&pch->file.rq); 3227 kfree(pch); 3228 } 3229 3230 static void __exit ppp_cleanup(void) 3231 { 3232 /* should never happen */ 3233 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count)) 3234 pr_err("PPP: removing module but units remain!\n"); 3235 rtnl_link_unregister(&ppp_link_ops); 3236 unregister_chrdev(PPP_MAJOR, "ppp"); 3237 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0)); 3238 class_destroy(ppp_class); 3239 unregister_pernet_device(&ppp_net_ops); 3240 } 3241 3242 /* 3243 * Units handling. Caller must protect concurrent access 3244 * by holding all_ppp_mutex 3245 */ 3246 3247 /* associate pointer with specified number */ 3248 static int unit_set(struct idr *p, void *ptr, int n) 3249 { 3250 int unit; 3251 3252 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL); 3253 if (unit == -ENOSPC) 3254 unit = -EINVAL; 3255 return unit; 3256 } 3257 3258 /* get new free unit number and associate pointer with it */ 3259 static int unit_get(struct idr *p, void *ptr) 3260 { 3261 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL); 3262 } 3263 3264 /* put unit number back to a pool */ 3265 static void unit_put(struct idr *p, int n) 3266 { 3267 idr_remove(p, n); 3268 } 3269 3270 /* get pointer associated with the number */ 3271 static void *unit_find(struct idr *p, int n) 3272 { 3273 return idr_find(p, n); 3274 } 3275 3276 /* Module/initialization stuff */ 3277 3278 module_init(ppp_init); 3279 module_exit(ppp_cleanup); 3280 3281 EXPORT_SYMBOL(ppp_register_net_channel); 3282 EXPORT_SYMBOL(ppp_register_channel); 3283 EXPORT_SYMBOL(ppp_unregister_channel); 3284 EXPORT_SYMBOL(ppp_channel_index); 3285 EXPORT_SYMBOL(ppp_unit_number); 3286 EXPORT_SYMBOL(ppp_dev_name); 3287 EXPORT_SYMBOL(ppp_input); 3288 EXPORT_SYMBOL(ppp_input_error); 3289 EXPORT_SYMBOL(ppp_output_wakeup); 3290 EXPORT_SYMBOL(ppp_register_compressor); 3291 EXPORT_SYMBOL(ppp_unregister_compressor); 3292 MODULE_LICENSE("GPL"); 3293 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0); 3294 MODULE_ALIAS_RTNL_LINK("ppp"); 3295 MODULE_ALIAS("devname:ppp"); 3296