1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Generic PPP layer for Linux. 4 * 5 * Copyright 1999-2002 Paul Mackerras. 6 * 7 * The generic PPP layer handles the PPP network interfaces, the 8 * /dev/ppp device, packet and VJ compression, and multilink. 9 * It talks to PPP `channels' via the interface defined in 10 * include/linux/ppp_channel.h. Channels provide the basic means for 11 * sending and receiving PPP frames on some kind of communications 12 * channel. 13 * 14 * Part of the code in this driver was inspired by the old async-only 15 * PPP driver, written by Michael Callahan and Al Longyear, and 16 * subsequently hacked by Paul Mackerras. 17 * 18 * ==FILEVERSION 20041108== 19 */ 20 21 #include <linux/module.h> 22 #include <linux/kernel.h> 23 #include <linux/sched/signal.h> 24 #include <linux/kmod.h> 25 #include <linux/init.h> 26 #include <linux/list.h> 27 #include <linux/idr.h> 28 #include <linux/netdevice.h> 29 #include <linux/poll.h> 30 #include <linux/ppp_defs.h> 31 #include <linux/filter.h> 32 #include <linux/ppp-ioctl.h> 33 #include <linux/ppp_channel.h> 34 #include <linux/ppp-comp.h> 35 #include <linux/skbuff.h> 36 #include <linux/rtnetlink.h> 37 #include <linux/if_arp.h> 38 #include <linux/ip.h> 39 #include <linux/tcp.h> 40 #include <linux/spinlock.h> 41 #include <linux/rwsem.h> 42 #include <linux/stddef.h> 43 #include <linux/device.h> 44 #include <linux/mutex.h> 45 #include <linux/slab.h> 46 #include <linux/file.h> 47 #include <asm/unaligned.h> 48 #include <net/slhc_vj.h> 49 #include <linux/atomic.h> 50 #include <linux/refcount.h> 51 52 #include <linux/nsproxy.h> 53 #include <net/net_namespace.h> 54 #include <net/netns/generic.h> 55 56 #define PPP_VERSION "2.4.2" 57 58 /* 59 * Network protocols we support. 60 */ 61 #define NP_IP 0 /* Internet Protocol V4 */ 62 #define NP_IPV6 1 /* Internet Protocol V6 */ 63 #define NP_IPX 2 /* IPX protocol */ 64 #define NP_AT 3 /* Appletalk protocol */ 65 #define NP_MPLS_UC 4 /* MPLS unicast */ 66 #define NP_MPLS_MC 5 /* MPLS multicast */ 67 #define NUM_NP 6 /* Number of NPs. */ 68 69 #define MPHDRLEN 6 /* multilink protocol header length */ 70 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */ 71 72 /* 73 * An instance of /dev/ppp can be associated with either a ppp 74 * interface unit or a ppp channel. In both cases, file->private_data 75 * points to one of these. 76 */ 77 struct ppp_file { 78 enum { 79 INTERFACE=1, CHANNEL 80 } kind; 81 struct sk_buff_head xq; /* pppd transmit queue */ 82 struct sk_buff_head rq; /* receive queue for pppd */ 83 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */ 84 refcount_t refcnt; /* # refs (incl /dev/ppp attached) */ 85 int hdrlen; /* space to leave for headers */ 86 int index; /* interface unit / channel number */ 87 int dead; /* unit/channel has been shut down */ 88 }; 89 90 #define PF_TO_X(pf, X) container_of(pf, X, file) 91 92 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp) 93 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel) 94 95 /* 96 * Data structure to hold primary network stats for which 97 * we want to use 64 bit storage. Other network stats 98 * are stored in dev->stats of the ppp strucute. 99 */ 100 struct ppp_link_stats { 101 u64 rx_packets; 102 u64 tx_packets; 103 u64 rx_bytes; 104 u64 tx_bytes; 105 }; 106 107 /* 108 * Data structure describing one ppp unit. 109 * A ppp unit corresponds to a ppp network interface device 110 * and represents a multilink bundle. 111 * It can have 0 or more ppp channels connected to it. 112 */ 113 struct ppp { 114 struct ppp_file file; /* stuff for read/write/poll 0 */ 115 struct file *owner; /* file that owns this unit 48 */ 116 struct list_head channels; /* list of attached channels 4c */ 117 int n_channels; /* how many channels are attached 54 */ 118 spinlock_t rlock; /* lock for receive side 58 */ 119 spinlock_t wlock; /* lock for transmit side 5c */ 120 int __percpu *xmit_recursion; /* xmit recursion detect */ 121 int mru; /* max receive unit 60 */ 122 unsigned int flags; /* control bits 64 */ 123 unsigned int xstate; /* transmit state bits 68 */ 124 unsigned int rstate; /* receive state bits 6c */ 125 int debug; /* debug flags 70 */ 126 struct slcompress *vj; /* state for VJ header compression */ 127 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */ 128 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */ 129 struct compressor *xcomp; /* transmit packet compressor 8c */ 130 void *xc_state; /* its internal state 90 */ 131 struct compressor *rcomp; /* receive decompressor 94 */ 132 void *rc_state; /* its internal state 98 */ 133 unsigned long last_xmit; /* jiffies when last pkt sent 9c */ 134 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */ 135 struct net_device *dev; /* network interface device a4 */ 136 int closing; /* is device closing down? a8 */ 137 #ifdef CONFIG_PPP_MULTILINK 138 int nxchan; /* next channel to send something on */ 139 u32 nxseq; /* next sequence number to send */ 140 int mrru; /* MP: max reconst. receive unit */ 141 u32 nextseq; /* MP: seq no of next packet */ 142 u32 minseq; /* MP: min of most recent seqnos */ 143 struct sk_buff_head mrq; /* MP: receive reconstruction queue */ 144 #endif /* CONFIG_PPP_MULTILINK */ 145 #ifdef CONFIG_PPP_FILTER 146 struct bpf_prog *pass_filter; /* filter for packets to pass */ 147 struct bpf_prog *active_filter; /* filter for pkts to reset idle */ 148 #endif /* CONFIG_PPP_FILTER */ 149 struct net *ppp_net; /* the net we belong to */ 150 struct ppp_link_stats stats64; /* 64 bit network stats */ 151 }; 152 153 /* 154 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC, 155 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP, 156 * SC_MUST_COMP 157 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR. 158 * Bits in xstate: SC_COMP_RUN 159 */ 160 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \ 161 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \ 162 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP) 163 164 /* 165 * Private data structure for each channel. 166 * This includes the data structure used for multilink. 167 */ 168 struct channel { 169 struct ppp_file file; /* stuff for read/write/poll */ 170 struct list_head list; /* link in all/new_channels list */ 171 struct ppp_channel *chan; /* public channel data structure */ 172 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */ 173 spinlock_t downl; /* protects `chan', file.xq dequeue */ 174 struct ppp *ppp; /* ppp unit we're connected to */ 175 struct net *chan_net; /* the net channel belongs to */ 176 struct list_head clist; /* link in list of channels per unit */ 177 rwlock_t upl; /* protects `ppp' */ 178 #ifdef CONFIG_PPP_MULTILINK 179 u8 avail; /* flag used in multilink stuff */ 180 u8 had_frag; /* >= 1 fragments have been sent */ 181 u32 lastseq; /* MP: last sequence # received */ 182 int speed; /* speed of the corresponding ppp channel*/ 183 #endif /* CONFIG_PPP_MULTILINK */ 184 }; 185 186 struct ppp_config { 187 struct file *file; 188 s32 unit; 189 bool ifname_is_set; 190 }; 191 192 /* 193 * SMP locking issues: 194 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels 195 * list and the ppp.n_channels field, you need to take both locks 196 * before you modify them. 197 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock -> 198 * channel.downl. 199 */ 200 201 static DEFINE_MUTEX(ppp_mutex); 202 static atomic_t ppp_unit_count = ATOMIC_INIT(0); 203 static atomic_t channel_count = ATOMIC_INIT(0); 204 205 /* per-net private data for this module */ 206 static unsigned int ppp_net_id __read_mostly; 207 struct ppp_net { 208 /* units to ppp mapping */ 209 struct idr units_idr; 210 211 /* 212 * all_ppp_mutex protects the units_idr mapping. 213 * It also ensures that finding a ppp unit in the units_idr 214 * map and updating its file.refcnt field is atomic. 215 */ 216 struct mutex all_ppp_mutex; 217 218 /* channels */ 219 struct list_head all_channels; 220 struct list_head new_channels; 221 int last_channel_index; 222 223 /* 224 * all_channels_lock protects all_channels and 225 * last_channel_index, and the atomicity of find 226 * a channel and updating its file.refcnt field. 227 */ 228 spinlock_t all_channels_lock; 229 }; 230 231 /* Get the PPP protocol number from a skb */ 232 #define PPP_PROTO(skb) get_unaligned_be16((skb)->data) 233 234 /* We limit the length of ppp->file.rq to this (arbitrary) value */ 235 #define PPP_MAX_RQLEN 32 236 237 /* 238 * Maximum number of multilink fragments queued up. 239 * This has to be large enough to cope with the maximum latency of 240 * the slowest channel relative to the others. Strictly it should 241 * depend on the number of channels and their characteristics. 242 */ 243 #define PPP_MP_MAX_QLEN 128 244 245 /* Multilink header bits. */ 246 #define B 0x80 /* this fragment begins a packet */ 247 #define E 0x40 /* this fragment ends a packet */ 248 249 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */ 250 #define seq_before(a, b) ((s32)((a) - (b)) < 0) 251 #define seq_after(a, b) ((s32)((a) - (b)) > 0) 252 253 /* Prototypes. */ 254 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 255 struct file *file, unsigned int cmd, unsigned long arg); 256 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb); 257 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb); 258 static void ppp_push(struct ppp *ppp); 259 static void ppp_channel_push(struct channel *pch); 260 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, 261 struct channel *pch); 262 static void ppp_receive_error(struct ppp *ppp); 263 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb); 264 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp, 265 struct sk_buff *skb); 266 #ifdef CONFIG_PPP_MULTILINK 267 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, 268 struct channel *pch); 269 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb); 270 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp); 271 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb); 272 #endif /* CONFIG_PPP_MULTILINK */ 273 static int ppp_set_compress(struct ppp *ppp, struct ppp_option_data *data); 274 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound); 275 static void ppp_ccp_closed(struct ppp *ppp); 276 static struct compressor *find_compressor(int type); 277 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st); 278 static int ppp_create_interface(struct net *net, struct file *file, int *unit); 279 static void init_ppp_file(struct ppp_file *pf, int kind); 280 static void ppp_destroy_interface(struct ppp *ppp); 281 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit); 282 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit); 283 static int ppp_connect_channel(struct channel *pch, int unit); 284 static int ppp_disconnect_channel(struct channel *pch); 285 static void ppp_destroy_channel(struct channel *pch); 286 static int unit_get(struct idr *p, void *ptr); 287 static int unit_set(struct idr *p, void *ptr, int n); 288 static void unit_put(struct idr *p, int n); 289 static void *unit_find(struct idr *p, int n); 290 static void ppp_setup(struct net_device *dev); 291 292 static const struct net_device_ops ppp_netdev_ops; 293 294 static struct class *ppp_class; 295 296 /* per net-namespace data */ 297 static inline struct ppp_net *ppp_pernet(struct net *net) 298 { 299 BUG_ON(!net); 300 301 return net_generic(net, ppp_net_id); 302 } 303 304 /* Translates a PPP protocol number to a NP index (NP == network protocol) */ 305 static inline int proto_to_npindex(int proto) 306 { 307 switch (proto) { 308 case PPP_IP: 309 return NP_IP; 310 case PPP_IPV6: 311 return NP_IPV6; 312 case PPP_IPX: 313 return NP_IPX; 314 case PPP_AT: 315 return NP_AT; 316 case PPP_MPLS_UC: 317 return NP_MPLS_UC; 318 case PPP_MPLS_MC: 319 return NP_MPLS_MC; 320 } 321 return -EINVAL; 322 } 323 324 /* Translates an NP index into a PPP protocol number */ 325 static const int npindex_to_proto[NUM_NP] = { 326 PPP_IP, 327 PPP_IPV6, 328 PPP_IPX, 329 PPP_AT, 330 PPP_MPLS_UC, 331 PPP_MPLS_MC, 332 }; 333 334 /* Translates an ethertype into an NP index */ 335 static inline int ethertype_to_npindex(int ethertype) 336 { 337 switch (ethertype) { 338 case ETH_P_IP: 339 return NP_IP; 340 case ETH_P_IPV6: 341 return NP_IPV6; 342 case ETH_P_IPX: 343 return NP_IPX; 344 case ETH_P_PPPTALK: 345 case ETH_P_ATALK: 346 return NP_AT; 347 case ETH_P_MPLS_UC: 348 return NP_MPLS_UC; 349 case ETH_P_MPLS_MC: 350 return NP_MPLS_MC; 351 } 352 return -1; 353 } 354 355 /* Translates an NP index into an ethertype */ 356 static const int npindex_to_ethertype[NUM_NP] = { 357 ETH_P_IP, 358 ETH_P_IPV6, 359 ETH_P_IPX, 360 ETH_P_PPPTALK, 361 ETH_P_MPLS_UC, 362 ETH_P_MPLS_MC, 363 }; 364 365 /* 366 * Locking shorthand. 367 */ 368 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock) 369 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock) 370 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock) 371 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock) 372 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \ 373 ppp_recv_lock(ppp); } while (0) 374 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \ 375 ppp_xmit_unlock(ppp); } while (0) 376 377 /* 378 * /dev/ppp device routines. 379 * The /dev/ppp device is used by pppd to control the ppp unit. 380 * It supports the read, write, ioctl and poll functions. 381 * Open instances of /dev/ppp can be in one of three states: 382 * unattached, attached to a ppp unit, or attached to a ppp channel. 383 */ 384 static int ppp_open(struct inode *inode, struct file *file) 385 { 386 /* 387 * This could (should?) be enforced by the permissions on /dev/ppp. 388 */ 389 if (!ns_capable(file->f_cred->user_ns, CAP_NET_ADMIN)) 390 return -EPERM; 391 return 0; 392 } 393 394 static int ppp_release(struct inode *unused, struct file *file) 395 { 396 struct ppp_file *pf = file->private_data; 397 struct ppp *ppp; 398 399 if (pf) { 400 file->private_data = NULL; 401 if (pf->kind == INTERFACE) { 402 ppp = PF_TO_PPP(pf); 403 rtnl_lock(); 404 if (file == ppp->owner) 405 unregister_netdevice(ppp->dev); 406 rtnl_unlock(); 407 } 408 if (refcount_dec_and_test(&pf->refcnt)) { 409 switch (pf->kind) { 410 case INTERFACE: 411 ppp_destroy_interface(PF_TO_PPP(pf)); 412 break; 413 case CHANNEL: 414 ppp_destroy_channel(PF_TO_CHANNEL(pf)); 415 break; 416 } 417 } 418 } 419 return 0; 420 } 421 422 static ssize_t ppp_read(struct file *file, char __user *buf, 423 size_t count, loff_t *ppos) 424 { 425 struct ppp_file *pf = file->private_data; 426 DECLARE_WAITQUEUE(wait, current); 427 ssize_t ret; 428 struct sk_buff *skb = NULL; 429 struct iovec iov; 430 struct iov_iter to; 431 432 ret = count; 433 434 if (!pf) 435 return -ENXIO; 436 add_wait_queue(&pf->rwait, &wait); 437 for (;;) { 438 set_current_state(TASK_INTERRUPTIBLE); 439 skb = skb_dequeue(&pf->rq); 440 if (skb) 441 break; 442 ret = 0; 443 if (pf->dead) 444 break; 445 if (pf->kind == INTERFACE) { 446 /* 447 * Return 0 (EOF) on an interface that has no 448 * channels connected, unless it is looping 449 * network traffic (demand mode). 450 */ 451 struct ppp *ppp = PF_TO_PPP(pf); 452 453 ppp_recv_lock(ppp); 454 if (ppp->n_channels == 0 && 455 (ppp->flags & SC_LOOP_TRAFFIC) == 0) { 456 ppp_recv_unlock(ppp); 457 break; 458 } 459 ppp_recv_unlock(ppp); 460 } 461 ret = -EAGAIN; 462 if (file->f_flags & O_NONBLOCK) 463 break; 464 ret = -ERESTARTSYS; 465 if (signal_pending(current)) 466 break; 467 schedule(); 468 } 469 set_current_state(TASK_RUNNING); 470 remove_wait_queue(&pf->rwait, &wait); 471 472 if (!skb) 473 goto out; 474 475 ret = -EOVERFLOW; 476 if (skb->len > count) 477 goto outf; 478 ret = -EFAULT; 479 iov.iov_base = buf; 480 iov.iov_len = count; 481 iov_iter_init(&to, READ, &iov, 1, count); 482 if (skb_copy_datagram_iter(skb, 0, &to, skb->len)) 483 goto outf; 484 ret = skb->len; 485 486 outf: 487 kfree_skb(skb); 488 out: 489 return ret; 490 } 491 492 static ssize_t ppp_write(struct file *file, const char __user *buf, 493 size_t count, loff_t *ppos) 494 { 495 struct ppp_file *pf = file->private_data; 496 struct sk_buff *skb; 497 ssize_t ret; 498 499 if (!pf) 500 return -ENXIO; 501 ret = -ENOMEM; 502 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL); 503 if (!skb) 504 goto out; 505 skb_reserve(skb, pf->hdrlen); 506 ret = -EFAULT; 507 if (copy_from_user(skb_put(skb, count), buf, count)) { 508 kfree_skb(skb); 509 goto out; 510 } 511 512 switch (pf->kind) { 513 case INTERFACE: 514 ppp_xmit_process(PF_TO_PPP(pf), skb); 515 break; 516 case CHANNEL: 517 skb_queue_tail(&pf->xq, skb); 518 ppp_channel_push(PF_TO_CHANNEL(pf)); 519 break; 520 } 521 522 ret = count; 523 524 out: 525 return ret; 526 } 527 528 /* No kernel lock - fine */ 529 static __poll_t ppp_poll(struct file *file, poll_table *wait) 530 { 531 struct ppp_file *pf = file->private_data; 532 __poll_t mask; 533 534 if (!pf) 535 return 0; 536 poll_wait(file, &pf->rwait, wait); 537 mask = EPOLLOUT | EPOLLWRNORM; 538 if (skb_peek(&pf->rq)) 539 mask |= EPOLLIN | EPOLLRDNORM; 540 if (pf->dead) 541 mask |= EPOLLHUP; 542 else if (pf->kind == INTERFACE) { 543 /* see comment in ppp_read */ 544 struct ppp *ppp = PF_TO_PPP(pf); 545 546 ppp_recv_lock(ppp); 547 if (ppp->n_channels == 0 && 548 (ppp->flags & SC_LOOP_TRAFFIC) == 0) 549 mask |= EPOLLIN | EPOLLRDNORM; 550 ppp_recv_unlock(ppp); 551 } 552 553 return mask; 554 } 555 556 #ifdef CONFIG_PPP_FILTER 557 static struct bpf_prog *get_filter(struct sock_fprog *uprog) 558 { 559 struct sock_fprog_kern fprog; 560 struct bpf_prog *res = NULL; 561 int err; 562 563 if (!uprog->len) 564 return NULL; 565 566 /* uprog->len is unsigned short, so no overflow here */ 567 fprog.len = uprog->len; 568 fprog.filter = memdup_user(uprog->filter, 569 uprog->len * sizeof(struct sock_filter)); 570 if (IS_ERR(fprog.filter)) 571 return ERR_CAST(fprog.filter); 572 573 err = bpf_prog_create(&res, &fprog); 574 kfree(fprog.filter); 575 576 return err ? ERR_PTR(err) : res; 577 } 578 579 static struct bpf_prog *ppp_get_filter(struct sock_fprog __user *p) 580 { 581 struct sock_fprog uprog; 582 583 if (copy_from_user(&uprog, p, sizeof(struct sock_fprog))) 584 return ERR_PTR(-EFAULT); 585 return get_filter(&uprog); 586 } 587 588 #ifdef CONFIG_COMPAT 589 struct sock_fprog32 { 590 unsigned short len; 591 compat_caddr_t filter; 592 }; 593 594 #define PPPIOCSPASS32 _IOW('t', 71, struct sock_fprog32) 595 #define PPPIOCSACTIVE32 _IOW('t', 70, struct sock_fprog32) 596 597 static struct bpf_prog *compat_ppp_get_filter(struct sock_fprog32 __user *p) 598 { 599 struct sock_fprog32 uprog32; 600 struct sock_fprog uprog; 601 602 if (copy_from_user(&uprog32, p, sizeof(struct sock_fprog32))) 603 return ERR_PTR(-EFAULT); 604 uprog.len = uprog32.len; 605 uprog.filter = compat_ptr(uprog32.filter); 606 return get_filter(&uprog); 607 } 608 #endif 609 #endif 610 611 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 612 { 613 struct ppp_file *pf; 614 struct ppp *ppp; 615 int err = -EFAULT, val, val2, i; 616 struct ppp_idle32 idle32; 617 struct ppp_idle64 idle64; 618 struct npioctl npi; 619 int unit, cflags; 620 struct slcompress *vj; 621 void __user *argp = (void __user *)arg; 622 int __user *p = argp; 623 624 mutex_lock(&ppp_mutex); 625 626 pf = file->private_data; 627 if (!pf) { 628 err = ppp_unattached_ioctl(current->nsproxy->net_ns, 629 pf, file, cmd, arg); 630 goto out; 631 } 632 633 if (cmd == PPPIOCDETACH) { 634 /* 635 * PPPIOCDETACH is no longer supported as it was heavily broken, 636 * and is only known to have been used by pppd older than 637 * ppp-2.4.2 (released November 2003). 638 */ 639 pr_warn_once("%s (%d) used obsolete PPPIOCDETACH ioctl\n", 640 current->comm, current->pid); 641 err = -EINVAL; 642 goto out; 643 } 644 645 if (pf->kind == CHANNEL) { 646 struct channel *pch; 647 struct ppp_channel *chan; 648 649 pch = PF_TO_CHANNEL(pf); 650 651 switch (cmd) { 652 case PPPIOCCONNECT: 653 if (get_user(unit, p)) 654 break; 655 err = ppp_connect_channel(pch, unit); 656 break; 657 658 case PPPIOCDISCONN: 659 err = ppp_disconnect_channel(pch); 660 break; 661 662 default: 663 down_read(&pch->chan_sem); 664 chan = pch->chan; 665 err = -ENOTTY; 666 if (chan && chan->ops->ioctl) 667 err = chan->ops->ioctl(chan, cmd, arg); 668 up_read(&pch->chan_sem); 669 } 670 goto out; 671 } 672 673 if (pf->kind != INTERFACE) { 674 /* can't happen */ 675 pr_err("PPP: not interface or channel??\n"); 676 err = -EINVAL; 677 goto out; 678 } 679 680 ppp = PF_TO_PPP(pf); 681 switch (cmd) { 682 case PPPIOCSMRU: 683 if (get_user(val, p)) 684 break; 685 ppp->mru = val; 686 err = 0; 687 break; 688 689 case PPPIOCSFLAGS: 690 if (get_user(val, p)) 691 break; 692 ppp_lock(ppp); 693 cflags = ppp->flags & ~val; 694 #ifdef CONFIG_PPP_MULTILINK 695 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK)) 696 ppp->nextseq = 0; 697 #endif 698 ppp->flags = val & SC_FLAG_BITS; 699 ppp_unlock(ppp); 700 if (cflags & SC_CCP_OPEN) 701 ppp_ccp_closed(ppp); 702 err = 0; 703 break; 704 705 case PPPIOCGFLAGS: 706 val = ppp->flags | ppp->xstate | ppp->rstate; 707 if (put_user(val, p)) 708 break; 709 err = 0; 710 break; 711 712 case PPPIOCSCOMPRESS: 713 { 714 struct ppp_option_data data; 715 if (copy_from_user(&data, argp, sizeof(data))) 716 err = -EFAULT; 717 else 718 err = ppp_set_compress(ppp, &data); 719 break; 720 } 721 case PPPIOCGUNIT: 722 if (put_user(ppp->file.index, p)) 723 break; 724 err = 0; 725 break; 726 727 case PPPIOCSDEBUG: 728 if (get_user(val, p)) 729 break; 730 ppp->debug = val; 731 err = 0; 732 break; 733 734 case PPPIOCGDEBUG: 735 if (put_user(ppp->debug, p)) 736 break; 737 err = 0; 738 break; 739 740 case PPPIOCGIDLE32: 741 idle32.xmit_idle = (jiffies - ppp->last_xmit) / HZ; 742 idle32.recv_idle = (jiffies - ppp->last_recv) / HZ; 743 if (copy_to_user(argp, &idle32, sizeof(idle32))) 744 break; 745 err = 0; 746 break; 747 748 case PPPIOCGIDLE64: 749 idle64.xmit_idle = (jiffies - ppp->last_xmit) / HZ; 750 idle64.recv_idle = (jiffies - ppp->last_recv) / HZ; 751 if (copy_to_user(argp, &idle64, sizeof(idle64))) 752 break; 753 err = 0; 754 break; 755 756 case PPPIOCSMAXCID: 757 if (get_user(val, p)) 758 break; 759 val2 = 15; 760 if ((val >> 16) != 0) { 761 val2 = val >> 16; 762 val &= 0xffff; 763 } 764 vj = slhc_init(val2+1, val+1); 765 if (IS_ERR(vj)) { 766 err = PTR_ERR(vj); 767 break; 768 } 769 ppp_lock(ppp); 770 if (ppp->vj) 771 slhc_free(ppp->vj); 772 ppp->vj = vj; 773 ppp_unlock(ppp); 774 err = 0; 775 break; 776 777 case PPPIOCGNPMODE: 778 case PPPIOCSNPMODE: 779 if (copy_from_user(&npi, argp, sizeof(npi))) 780 break; 781 err = proto_to_npindex(npi.protocol); 782 if (err < 0) 783 break; 784 i = err; 785 if (cmd == PPPIOCGNPMODE) { 786 err = -EFAULT; 787 npi.mode = ppp->npmode[i]; 788 if (copy_to_user(argp, &npi, sizeof(npi))) 789 break; 790 } else { 791 ppp->npmode[i] = npi.mode; 792 /* we may be able to transmit more packets now (??) */ 793 netif_wake_queue(ppp->dev); 794 } 795 err = 0; 796 break; 797 798 #ifdef CONFIG_PPP_FILTER 799 case PPPIOCSPASS: 800 case PPPIOCSACTIVE: 801 { 802 struct bpf_prog *filter = ppp_get_filter(argp); 803 struct bpf_prog **which; 804 805 if (IS_ERR(filter)) { 806 err = PTR_ERR(filter); 807 break; 808 } 809 if (cmd == PPPIOCSPASS) 810 which = &ppp->pass_filter; 811 else 812 which = &ppp->active_filter; 813 ppp_lock(ppp); 814 if (*which) 815 bpf_prog_destroy(*which); 816 *which = filter; 817 ppp_unlock(ppp); 818 err = 0; 819 break; 820 } 821 #endif /* CONFIG_PPP_FILTER */ 822 823 #ifdef CONFIG_PPP_MULTILINK 824 case PPPIOCSMRRU: 825 if (get_user(val, p)) 826 break; 827 ppp_recv_lock(ppp); 828 ppp->mrru = val; 829 ppp_recv_unlock(ppp); 830 err = 0; 831 break; 832 #endif /* CONFIG_PPP_MULTILINK */ 833 834 default: 835 err = -ENOTTY; 836 } 837 838 out: 839 mutex_unlock(&ppp_mutex); 840 841 return err; 842 } 843 844 #ifdef CONFIG_COMPAT 845 struct ppp_option_data32 { 846 compat_uptr_t ptr; 847 u32 length; 848 compat_int_t transmit; 849 }; 850 #define PPPIOCSCOMPRESS32 _IOW('t', 77, struct ppp_option_data32) 851 852 static long ppp_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 853 { 854 struct ppp_file *pf; 855 int err = -ENOIOCTLCMD; 856 void __user *argp = (void __user *)arg; 857 858 mutex_lock(&ppp_mutex); 859 860 pf = file->private_data; 861 if (pf && pf->kind == INTERFACE) { 862 struct ppp *ppp = PF_TO_PPP(pf); 863 switch (cmd) { 864 #ifdef CONFIG_PPP_FILTER 865 case PPPIOCSPASS32: 866 case PPPIOCSACTIVE32: 867 { 868 struct bpf_prog *filter = compat_ppp_get_filter(argp); 869 struct bpf_prog **which; 870 871 if (IS_ERR(filter)) { 872 err = PTR_ERR(filter); 873 break; 874 } 875 if (cmd == PPPIOCSPASS32) 876 which = &ppp->pass_filter; 877 else 878 which = &ppp->active_filter; 879 ppp_lock(ppp); 880 if (*which) 881 bpf_prog_destroy(*which); 882 *which = filter; 883 ppp_unlock(ppp); 884 err = 0; 885 break; 886 } 887 #endif /* CONFIG_PPP_FILTER */ 888 case PPPIOCSCOMPRESS32: 889 { 890 struct ppp_option_data32 data32; 891 if (copy_from_user(&data32, argp, sizeof(data32))) { 892 err = -EFAULT; 893 } else { 894 struct ppp_option_data data = { 895 .ptr = compat_ptr(data32.ptr), 896 .length = data32.length, 897 .transmit = data32.transmit 898 }; 899 err = ppp_set_compress(ppp, &data); 900 } 901 break; 902 } 903 } 904 } 905 mutex_unlock(&ppp_mutex); 906 907 /* all other commands have compatible arguments */ 908 if (err == -ENOIOCTLCMD) 909 err = ppp_ioctl(file, cmd, (unsigned long)compat_ptr(arg)); 910 911 return err; 912 } 913 #endif 914 915 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 916 struct file *file, unsigned int cmd, unsigned long arg) 917 { 918 int unit, err = -EFAULT; 919 struct ppp *ppp; 920 struct channel *chan; 921 struct ppp_net *pn; 922 int __user *p = (int __user *)arg; 923 924 switch (cmd) { 925 case PPPIOCNEWUNIT: 926 /* Create a new ppp unit */ 927 if (get_user(unit, p)) 928 break; 929 err = ppp_create_interface(net, file, &unit); 930 if (err < 0) 931 break; 932 933 err = -EFAULT; 934 if (put_user(unit, p)) 935 break; 936 err = 0; 937 break; 938 939 case PPPIOCATTACH: 940 /* Attach to an existing ppp unit */ 941 if (get_user(unit, p)) 942 break; 943 err = -ENXIO; 944 pn = ppp_pernet(net); 945 mutex_lock(&pn->all_ppp_mutex); 946 ppp = ppp_find_unit(pn, unit); 947 if (ppp) { 948 refcount_inc(&ppp->file.refcnt); 949 file->private_data = &ppp->file; 950 err = 0; 951 } 952 mutex_unlock(&pn->all_ppp_mutex); 953 break; 954 955 case PPPIOCATTCHAN: 956 if (get_user(unit, p)) 957 break; 958 err = -ENXIO; 959 pn = ppp_pernet(net); 960 spin_lock_bh(&pn->all_channels_lock); 961 chan = ppp_find_channel(pn, unit); 962 if (chan) { 963 refcount_inc(&chan->file.refcnt); 964 file->private_data = &chan->file; 965 err = 0; 966 } 967 spin_unlock_bh(&pn->all_channels_lock); 968 break; 969 970 default: 971 err = -ENOTTY; 972 } 973 974 return err; 975 } 976 977 static const struct file_operations ppp_device_fops = { 978 .owner = THIS_MODULE, 979 .read = ppp_read, 980 .write = ppp_write, 981 .poll = ppp_poll, 982 .unlocked_ioctl = ppp_ioctl, 983 #ifdef CONFIG_COMPAT 984 .compat_ioctl = ppp_compat_ioctl, 985 #endif 986 .open = ppp_open, 987 .release = ppp_release, 988 .llseek = noop_llseek, 989 }; 990 991 static __net_init int ppp_init_net(struct net *net) 992 { 993 struct ppp_net *pn = net_generic(net, ppp_net_id); 994 995 idr_init(&pn->units_idr); 996 mutex_init(&pn->all_ppp_mutex); 997 998 INIT_LIST_HEAD(&pn->all_channels); 999 INIT_LIST_HEAD(&pn->new_channels); 1000 1001 spin_lock_init(&pn->all_channels_lock); 1002 1003 return 0; 1004 } 1005 1006 static __net_exit void ppp_exit_net(struct net *net) 1007 { 1008 struct ppp_net *pn = net_generic(net, ppp_net_id); 1009 struct net_device *dev; 1010 struct net_device *aux; 1011 struct ppp *ppp; 1012 LIST_HEAD(list); 1013 int id; 1014 1015 rtnl_lock(); 1016 for_each_netdev_safe(net, dev, aux) { 1017 if (dev->netdev_ops == &ppp_netdev_ops) 1018 unregister_netdevice_queue(dev, &list); 1019 } 1020 1021 idr_for_each_entry(&pn->units_idr, ppp, id) 1022 /* Skip devices already unregistered by previous loop */ 1023 if (!net_eq(dev_net(ppp->dev), net)) 1024 unregister_netdevice_queue(ppp->dev, &list); 1025 1026 unregister_netdevice_many(&list); 1027 rtnl_unlock(); 1028 1029 mutex_destroy(&pn->all_ppp_mutex); 1030 idr_destroy(&pn->units_idr); 1031 WARN_ON_ONCE(!list_empty(&pn->all_channels)); 1032 WARN_ON_ONCE(!list_empty(&pn->new_channels)); 1033 } 1034 1035 static struct pernet_operations ppp_net_ops = { 1036 .init = ppp_init_net, 1037 .exit = ppp_exit_net, 1038 .id = &ppp_net_id, 1039 .size = sizeof(struct ppp_net), 1040 }; 1041 1042 static int ppp_unit_register(struct ppp *ppp, int unit, bool ifname_is_set) 1043 { 1044 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 1045 int ret; 1046 1047 mutex_lock(&pn->all_ppp_mutex); 1048 1049 if (unit < 0) { 1050 ret = unit_get(&pn->units_idr, ppp); 1051 if (ret < 0) 1052 goto err; 1053 } else { 1054 /* Caller asked for a specific unit number. Fail with -EEXIST 1055 * if unavailable. For backward compatibility, return -EEXIST 1056 * too if idr allocation fails; this makes pppd retry without 1057 * requesting a specific unit number. 1058 */ 1059 if (unit_find(&pn->units_idr, unit)) { 1060 ret = -EEXIST; 1061 goto err; 1062 } 1063 ret = unit_set(&pn->units_idr, ppp, unit); 1064 if (ret < 0) { 1065 /* Rewrite error for backward compatibility */ 1066 ret = -EEXIST; 1067 goto err; 1068 } 1069 } 1070 ppp->file.index = ret; 1071 1072 if (!ifname_is_set) 1073 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ppp->file.index); 1074 1075 mutex_unlock(&pn->all_ppp_mutex); 1076 1077 ret = register_netdevice(ppp->dev); 1078 if (ret < 0) 1079 goto err_unit; 1080 1081 atomic_inc(&ppp_unit_count); 1082 1083 return 0; 1084 1085 err_unit: 1086 mutex_lock(&pn->all_ppp_mutex); 1087 unit_put(&pn->units_idr, ppp->file.index); 1088 err: 1089 mutex_unlock(&pn->all_ppp_mutex); 1090 1091 return ret; 1092 } 1093 1094 static int ppp_dev_configure(struct net *src_net, struct net_device *dev, 1095 const struct ppp_config *conf) 1096 { 1097 struct ppp *ppp = netdev_priv(dev); 1098 int indx; 1099 int err; 1100 int cpu; 1101 1102 ppp->dev = dev; 1103 ppp->ppp_net = src_net; 1104 ppp->mru = PPP_MRU; 1105 ppp->owner = conf->file; 1106 1107 init_ppp_file(&ppp->file, INTERFACE); 1108 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */ 1109 1110 for (indx = 0; indx < NUM_NP; ++indx) 1111 ppp->npmode[indx] = NPMODE_PASS; 1112 INIT_LIST_HEAD(&ppp->channels); 1113 spin_lock_init(&ppp->rlock); 1114 spin_lock_init(&ppp->wlock); 1115 1116 ppp->xmit_recursion = alloc_percpu(int); 1117 if (!ppp->xmit_recursion) { 1118 err = -ENOMEM; 1119 goto err1; 1120 } 1121 for_each_possible_cpu(cpu) 1122 (*per_cpu_ptr(ppp->xmit_recursion, cpu)) = 0; 1123 1124 #ifdef CONFIG_PPP_MULTILINK 1125 ppp->minseq = -1; 1126 skb_queue_head_init(&ppp->mrq); 1127 #endif /* CONFIG_PPP_MULTILINK */ 1128 #ifdef CONFIG_PPP_FILTER 1129 ppp->pass_filter = NULL; 1130 ppp->active_filter = NULL; 1131 #endif /* CONFIG_PPP_FILTER */ 1132 1133 err = ppp_unit_register(ppp, conf->unit, conf->ifname_is_set); 1134 if (err < 0) 1135 goto err2; 1136 1137 conf->file->private_data = &ppp->file; 1138 1139 return 0; 1140 err2: 1141 free_percpu(ppp->xmit_recursion); 1142 err1: 1143 return err; 1144 } 1145 1146 static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = { 1147 [IFLA_PPP_DEV_FD] = { .type = NLA_S32 }, 1148 }; 1149 1150 static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[], 1151 struct netlink_ext_ack *extack) 1152 { 1153 if (!data) 1154 return -EINVAL; 1155 1156 if (!data[IFLA_PPP_DEV_FD]) 1157 return -EINVAL; 1158 if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0) 1159 return -EBADF; 1160 1161 return 0; 1162 } 1163 1164 static int ppp_nl_newlink(struct net *src_net, struct net_device *dev, 1165 struct nlattr *tb[], struct nlattr *data[], 1166 struct netlink_ext_ack *extack) 1167 { 1168 struct ppp_config conf = { 1169 .unit = -1, 1170 .ifname_is_set = true, 1171 }; 1172 struct file *file; 1173 int err; 1174 1175 file = fget(nla_get_s32(data[IFLA_PPP_DEV_FD])); 1176 if (!file) 1177 return -EBADF; 1178 1179 /* rtnl_lock is already held here, but ppp_create_interface() locks 1180 * ppp_mutex before holding rtnl_lock. Using mutex_trylock() avoids 1181 * possible deadlock due to lock order inversion, at the cost of 1182 * pushing the problem back to userspace. 1183 */ 1184 if (!mutex_trylock(&ppp_mutex)) { 1185 err = -EBUSY; 1186 goto out; 1187 } 1188 1189 if (file->f_op != &ppp_device_fops || file->private_data) { 1190 err = -EBADF; 1191 goto out_unlock; 1192 } 1193 1194 conf.file = file; 1195 1196 /* Don't use device name generated by the rtnetlink layer when ifname 1197 * isn't specified. Let ppp_dev_configure() set the device name using 1198 * the PPP unit identifer as suffix (i.e. ppp<unit_id>). This allows 1199 * userspace to infer the device name using to the PPPIOCGUNIT ioctl. 1200 */ 1201 if (!tb[IFLA_IFNAME]) 1202 conf.ifname_is_set = false; 1203 1204 err = ppp_dev_configure(src_net, dev, &conf); 1205 1206 out_unlock: 1207 mutex_unlock(&ppp_mutex); 1208 out: 1209 fput(file); 1210 1211 return err; 1212 } 1213 1214 static void ppp_nl_dellink(struct net_device *dev, struct list_head *head) 1215 { 1216 unregister_netdevice_queue(dev, head); 1217 } 1218 1219 static size_t ppp_nl_get_size(const struct net_device *dev) 1220 { 1221 return 0; 1222 } 1223 1224 static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev) 1225 { 1226 return 0; 1227 } 1228 1229 static struct net *ppp_nl_get_link_net(const struct net_device *dev) 1230 { 1231 struct ppp *ppp = netdev_priv(dev); 1232 1233 return ppp->ppp_net; 1234 } 1235 1236 static struct rtnl_link_ops ppp_link_ops __read_mostly = { 1237 .kind = "ppp", 1238 .maxtype = IFLA_PPP_MAX, 1239 .policy = ppp_nl_policy, 1240 .priv_size = sizeof(struct ppp), 1241 .setup = ppp_setup, 1242 .validate = ppp_nl_validate, 1243 .newlink = ppp_nl_newlink, 1244 .dellink = ppp_nl_dellink, 1245 .get_size = ppp_nl_get_size, 1246 .fill_info = ppp_nl_fill_info, 1247 .get_link_net = ppp_nl_get_link_net, 1248 }; 1249 1250 #define PPP_MAJOR 108 1251 1252 /* Called at boot time if ppp is compiled into the kernel, 1253 or at module load time (from init_module) if compiled as a module. */ 1254 static int __init ppp_init(void) 1255 { 1256 int err; 1257 1258 pr_info("PPP generic driver version " PPP_VERSION "\n"); 1259 1260 err = register_pernet_device(&ppp_net_ops); 1261 if (err) { 1262 pr_err("failed to register PPP pernet device (%d)\n", err); 1263 goto out; 1264 } 1265 1266 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops); 1267 if (err) { 1268 pr_err("failed to register PPP device (%d)\n", err); 1269 goto out_net; 1270 } 1271 1272 ppp_class = class_create(THIS_MODULE, "ppp"); 1273 if (IS_ERR(ppp_class)) { 1274 err = PTR_ERR(ppp_class); 1275 goto out_chrdev; 1276 } 1277 1278 err = rtnl_link_register(&ppp_link_ops); 1279 if (err) { 1280 pr_err("failed to register rtnetlink PPP handler\n"); 1281 goto out_class; 1282 } 1283 1284 /* not a big deal if we fail here :-) */ 1285 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp"); 1286 1287 return 0; 1288 1289 out_class: 1290 class_destroy(ppp_class); 1291 out_chrdev: 1292 unregister_chrdev(PPP_MAJOR, "ppp"); 1293 out_net: 1294 unregister_pernet_device(&ppp_net_ops); 1295 out: 1296 return err; 1297 } 1298 1299 /* 1300 * Network interface unit routines. 1301 */ 1302 static netdev_tx_t 1303 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev) 1304 { 1305 struct ppp *ppp = netdev_priv(dev); 1306 int npi, proto; 1307 unsigned char *pp; 1308 1309 npi = ethertype_to_npindex(ntohs(skb->protocol)); 1310 if (npi < 0) 1311 goto outf; 1312 1313 /* Drop, accept or reject the packet */ 1314 switch (ppp->npmode[npi]) { 1315 case NPMODE_PASS: 1316 break; 1317 case NPMODE_QUEUE: 1318 /* it would be nice to have a way to tell the network 1319 system to queue this one up for later. */ 1320 goto outf; 1321 case NPMODE_DROP: 1322 case NPMODE_ERROR: 1323 goto outf; 1324 } 1325 1326 /* Put the 2-byte PPP protocol number on the front, 1327 making sure there is room for the address and control fields. */ 1328 if (skb_cow_head(skb, PPP_HDRLEN)) 1329 goto outf; 1330 1331 pp = skb_push(skb, 2); 1332 proto = npindex_to_proto[npi]; 1333 put_unaligned_be16(proto, pp); 1334 1335 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev))); 1336 ppp_xmit_process(ppp, skb); 1337 1338 return NETDEV_TX_OK; 1339 1340 outf: 1341 kfree_skb(skb); 1342 ++dev->stats.tx_dropped; 1343 return NETDEV_TX_OK; 1344 } 1345 1346 static int 1347 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 1348 { 1349 struct ppp *ppp = netdev_priv(dev); 1350 int err = -EFAULT; 1351 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data; 1352 struct ppp_stats stats; 1353 struct ppp_comp_stats cstats; 1354 char *vers; 1355 1356 switch (cmd) { 1357 case SIOCGPPPSTATS: 1358 ppp_get_stats(ppp, &stats); 1359 if (copy_to_user(addr, &stats, sizeof(stats))) 1360 break; 1361 err = 0; 1362 break; 1363 1364 case SIOCGPPPCSTATS: 1365 memset(&cstats, 0, sizeof(cstats)); 1366 if (ppp->xc_state) 1367 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c); 1368 if (ppp->rc_state) 1369 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d); 1370 if (copy_to_user(addr, &cstats, sizeof(cstats))) 1371 break; 1372 err = 0; 1373 break; 1374 1375 case SIOCGPPPVER: 1376 vers = PPP_VERSION; 1377 if (copy_to_user(addr, vers, strlen(vers) + 1)) 1378 break; 1379 err = 0; 1380 break; 1381 1382 default: 1383 err = -EINVAL; 1384 } 1385 1386 return err; 1387 } 1388 1389 static void 1390 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64) 1391 { 1392 struct ppp *ppp = netdev_priv(dev); 1393 1394 ppp_recv_lock(ppp); 1395 stats64->rx_packets = ppp->stats64.rx_packets; 1396 stats64->rx_bytes = ppp->stats64.rx_bytes; 1397 ppp_recv_unlock(ppp); 1398 1399 ppp_xmit_lock(ppp); 1400 stats64->tx_packets = ppp->stats64.tx_packets; 1401 stats64->tx_bytes = ppp->stats64.tx_bytes; 1402 ppp_xmit_unlock(ppp); 1403 1404 stats64->rx_errors = dev->stats.rx_errors; 1405 stats64->tx_errors = dev->stats.tx_errors; 1406 stats64->rx_dropped = dev->stats.rx_dropped; 1407 stats64->tx_dropped = dev->stats.tx_dropped; 1408 stats64->rx_length_errors = dev->stats.rx_length_errors; 1409 } 1410 1411 static int ppp_dev_init(struct net_device *dev) 1412 { 1413 struct ppp *ppp; 1414 1415 ppp = netdev_priv(dev); 1416 /* Let the netdevice take a reference on the ppp file. This ensures 1417 * that ppp_destroy_interface() won't run before the device gets 1418 * unregistered. 1419 */ 1420 refcount_inc(&ppp->file.refcnt); 1421 1422 return 0; 1423 } 1424 1425 static void ppp_dev_uninit(struct net_device *dev) 1426 { 1427 struct ppp *ppp = netdev_priv(dev); 1428 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 1429 1430 ppp_lock(ppp); 1431 ppp->closing = 1; 1432 ppp_unlock(ppp); 1433 1434 mutex_lock(&pn->all_ppp_mutex); 1435 unit_put(&pn->units_idr, ppp->file.index); 1436 mutex_unlock(&pn->all_ppp_mutex); 1437 1438 ppp->owner = NULL; 1439 1440 ppp->file.dead = 1; 1441 wake_up_interruptible(&ppp->file.rwait); 1442 } 1443 1444 static void ppp_dev_priv_destructor(struct net_device *dev) 1445 { 1446 struct ppp *ppp; 1447 1448 ppp = netdev_priv(dev); 1449 if (refcount_dec_and_test(&ppp->file.refcnt)) 1450 ppp_destroy_interface(ppp); 1451 } 1452 1453 static const struct net_device_ops ppp_netdev_ops = { 1454 .ndo_init = ppp_dev_init, 1455 .ndo_uninit = ppp_dev_uninit, 1456 .ndo_start_xmit = ppp_start_xmit, 1457 .ndo_do_ioctl = ppp_net_ioctl, 1458 .ndo_get_stats64 = ppp_get_stats64, 1459 }; 1460 1461 static struct device_type ppp_type = { 1462 .name = "ppp", 1463 }; 1464 1465 static void ppp_setup(struct net_device *dev) 1466 { 1467 dev->netdev_ops = &ppp_netdev_ops; 1468 SET_NETDEV_DEVTYPE(dev, &ppp_type); 1469 1470 dev->features |= NETIF_F_LLTX; 1471 1472 dev->hard_header_len = PPP_HDRLEN; 1473 dev->mtu = PPP_MRU; 1474 dev->addr_len = 0; 1475 dev->tx_queue_len = 3; 1476 dev->type = ARPHRD_PPP; 1477 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 1478 dev->priv_destructor = ppp_dev_priv_destructor; 1479 netif_keep_dst(dev); 1480 } 1481 1482 /* 1483 * Transmit-side routines. 1484 */ 1485 1486 /* Called to do any work queued up on the transmit side that can now be done */ 1487 static void __ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb) 1488 { 1489 ppp_xmit_lock(ppp); 1490 if (!ppp->closing) { 1491 ppp_push(ppp); 1492 1493 if (skb) 1494 skb_queue_tail(&ppp->file.xq, skb); 1495 while (!ppp->xmit_pending && 1496 (skb = skb_dequeue(&ppp->file.xq))) 1497 ppp_send_frame(ppp, skb); 1498 /* If there's no work left to do, tell the core net 1499 code that we can accept some more. */ 1500 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq)) 1501 netif_wake_queue(ppp->dev); 1502 else 1503 netif_stop_queue(ppp->dev); 1504 } else { 1505 kfree_skb(skb); 1506 } 1507 ppp_xmit_unlock(ppp); 1508 } 1509 1510 static void ppp_xmit_process(struct ppp *ppp, struct sk_buff *skb) 1511 { 1512 local_bh_disable(); 1513 1514 if (unlikely(*this_cpu_ptr(ppp->xmit_recursion))) 1515 goto err; 1516 1517 (*this_cpu_ptr(ppp->xmit_recursion))++; 1518 __ppp_xmit_process(ppp, skb); 1519 (*this_cpu_ptr(ppp->xmit_recursion))--; 1520 1521 local_bh_enable(); 1522 1523 return; 1524 1525 err: 1526 local_bh_enable(); 1527 1528 kfree_skb(skb); 1529 1530 if (net_ratelimit()) 1531 netdev_err(ppp->dev, "recursion detected\n"); 1532 } 1533 1534 static inline struct sk_buff * 1535 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) 1536 { 1537 struct sk_buff *new_skb; 1538 int len; 1539 int new_skb_size = ppp->dev->mtu + 1540 ppp->xcomp->comp_extra + ppp->dev->hard_header_len; 1541 int compressor_skb_size = ppp->dev->mtu + 1542 ppp->xcomp->comp_extra + PPP_HDRLEN; 1543 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC); 1544 if (!new_skb) { 1545 if (net_ratelimit()) 1546 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n"); 1547 return NULL; 1548 } 1549 if (ppp->dev->hard_header_len > PPP_HDRLEN) 1550 skb_reserve(new_skb, 1551 ppp->dev->hard_header_len - PPP_HDRLEN); 1552 1553 /* compressor still expects A/C bytes in hdr */ 1554 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, 1555 new_skb->data, skb->len + 2, 1556 compressor_skb_size); 1557 if (len > 0 && (ppp->flags & SC_CCP_UP)) { 1558 consume_skb(skb); 1559 skb = new_skb; 1560 skb_put(skb, len); 1561 skb_pull(skb, 2); /* pull off A/C bytes */ 1562 } else if (len == 0) { 1563 /* didn't compress, or CCP not up yet */ 1564 consume_skb(new_skb); 1565 new_skb = skb; 1566 } else { 1567 /* 1568 * (len < 0) 1569 * MPPE requires that we do not send unencrypted 1570 * frames. The compressor will return -1 if we 1571 * should drop the frame. We cannot simply test 1572 * the compress_proto because MPPE and MPPC share 1573 * the same number. 1574 */ 1575 if (net_ratelimit()) 1576 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n"); 1577 kfree_skb(skb); 1578 consume_skb(new_skb); 1579 new_skb = NULL; 1580 } 1581 return new_skb; 1582 } 1583 1584 /* 1585 * Compress and send a frame. 1586 * The caller should have locked the xmit path, 1587 * and xmit_pending should be 0. 1588 */ 1589 static void 1590 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) 1591 { 1592 int proto = PPP_PROTO(skb); 1593 struct sk_buff *new_skb; 1594 int len; 1595 unsigned char *cp; 1596 1597 if (proto < 0x8000) { 1598 #ifdef CONFIG_PPP_FILTER 1599 /* check if we should pass this packet */ 1600 /* the filter instructions are constructed assuming 1601 a four-byte PPP header on each packet */ 1602 *(u8 *)skb_push(skb, 2) = 1; 1603 if (ppp->pass_filter && 1604 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 1605 if (ppp->debug & 1) 1606 netdev_printk(KERN_DEBUG, ppp->dev, 1607 "PPP: outbound frame " 1608 "not passed\n"); 1609 kfree_skb(skb); 1610 return; 1611 } 1612 /* if this packet passes the active filter, record the time */ 1613 if (!(ppp->active_filter && 1614 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 1615 ppp->last_xmit = jiffies; 1616 skb_pull(skb, 2); 1617 #else 1618 /* for data packets, record the time */ 1619 ppp->last_xmit = jiffies; 1620 #endif /* CONFIG_PPP_FILTER */ 1621 } 1622 1623 ++ppp->stats64.tx_packets; 1624 ppp->stats64.tx_bytes += skb->len - 2; 1625 1626 switch (proto) { 1627 case PPP_IP: 1628 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0) 1629 break; 1630 /* try to do VJ TCP header compression */ 1631 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2, 1632 GFP_ATOMIC); 1633 if (!new_skb) { 1634 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n"); 1635 goto drop; 1636 } 1637 skb_reserve(new_skb, ppp->dev->hard_header_len - 2); 1638 cp = skb->data + 2; 1639 len = slhc_compress(ppp->vj, cp, skb->len - 2, 1640 new_skb->data + 2, &cp, 1641 !(ppp->flags & SC_NO_TCP_CCID)); 1642 if (cp == skb->data + 2) { 1643 /* didn't compress */ 1644 consume_skb(new_skb); 1645 } else { 1646 if (cp[0] & SL_TYPE_COMPRESSED_TCP) { 1647 proto = PPP_VJC_COMP; 1648 cp[0] &= ~SL_TYPE_COMPRESSED_TCP; 1649 } else { 1650 proto = PPP_VJC_UNCOMP; 1651 cp[0] = skb->data[2]; 1652 } 1653 consume_skb(skb); 1654 skb = new_skb; 1655 cp = skb_put(skb, len + 2); 1656 cp[0] = 0; 1657 cp[1] = proto; 1658 } 1659 break; 1660 1661 case PPP_CCP: 1662 /* peek at outbound CCP frames */ 1663 ppp_ccp_peek(ppp, skb, 0); 1664 break; 1665 } 1666 1667 /* try to do packet compression */ 1668 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state && 1669 proto != PPP_LCP && proto != PPP_CCP) { 1670 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) { 1671 if (net_ratelimit()) 1672 netdev_err(ppp->dev, 1673 "ppp: compression required but " 1674 "down - pkt dropped.\n"); 1675 goto drop; 1676 } 1677 skb = pad_compress_skb(ppp, skb); 1678 if (!skb) 1679 goto drop; 1680 } 1681 1682 /* 1683 * If we are waiting for traffic (demand dialling), 1684 * queue it up for pppd to receive. 1685 */ 1686 if (ppp->flags & SC_LOOP_TRAFFIC) { 1687 if (ppp->file.rq.qlen > PPP_MAX_RQLEN) 1688 goto drop; 1689 skb_queue_tail(&ppp->file.rq, skb); 1690 wake_up_interruptible(&ppp->file.rwait); 1691 return; 1692 } 1693 1694 ppp->xmit_pending = skb; 1695 ppp_push(ppp); 1696 return; 1697 1698 drop: 1699 kfree_skb(skb); 1700 ++ppp->dev->stats.tx_errors; 1701 } 1702 1703 /* 1704 * Try to send the frame in xmit_pending. 1705 * The caller should have the xmit path locked. 1706 */ 1707 static void 1708 ppp_push(struct ppp *ppp) 1709 { 1710 struct list_head *list; 1711 struct channel *pch; 1712 struct sk_buff *skb = ppp->xmit_pending; 1713 1714 if (!skb) 1715 return; 1716 1717 list = &ppp->channels; 1718 if (list_empty(list)) { 1719 /* nowhere to send the packet, just drop it */ 1720 ppp->xmit_pending = NULL; 1721 kfree_skb(skb); 1722 return; 1723 } 1724 1725 if ((ppp->flags & SC_MULTILINK) == 0) { 1726 /* not doing multilink: send it down the first channel */ 1727 list = list->next; 1728 pch = list_entry(list, struct channel, clist); 1729 1730 spin_lock(&pch->downl); 1731 if (pch->chan) { 1732 if (pch->chan->ops->start_xmit(pch->chan, skb)) 1733 ppp->xmit_pending = NULL; 1734 } else { 1735 /* channel got unregistered */ 1736 kfree_skb(skb); 1737 ppp->xmit_pending = NULL; 1738 } 1739 spin_unlock(&pch->downl); 1740 return; 1741 } 1742 1743 #ifdef CONFIG_PPP_MULTILINK 1744 /* Multilink: fragment the packet over as many links 1745 as can take the packet at the moment. */ 1746 if (!ppp_mp_explode(ppp, skb)) 1747 return; 1748 #endif /* CONFIG_PPP_MULTILINK */ 1749 1750 ppp->xmit_pending = NULL; 1751 kfree_skb(skb); 1752 } 1753 1754 #ifdef CONFIG_PPP_MULTILINK 1755 static bool mp_protocol_compress __read_mostly = true; 1756 module_param(mp_protocol_compress, bool, 0644); 1757 MODULE_PARM_DESC(mp_protocol_compress, 1758 "compress protocol id in multilink fragments"); 1759 1760 /* 1761 * Divide a packet to be transmitted into fragments and 1762 * send them out the individual links. 1763 */ 1764 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb) 1765 { 1766 int len, totlen; 1767 int i, bits, hdrlen, mtu; 1768 int flen; 1769 int navail, nfree, nzero; 1770 int nbigger; 1771 int totspeed; 1772 int totfree; 1773 unsigned char *p, *q; 1774 struct list_head *list; 1775 struct channel *pch; 1776 struct sk_buff *frag; 1777 struct ppp_channel *chan; 1778 1779 totspeed = 0; /*total bitrate of the bundle*/ 1780 nfree = 0; /* # channels which have no packet already queued */ 1781 navail = 0; /* total # of usable channels (not deregistered) */ 1782 nzero = 0; /* number of channels with zero speed associated*/ 1783 totfree = 0; /*total # of channels available and 1784 *having no queued packets before 1785 *starting the fragmentation*/ 1786 1787 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1788 i = 0; 1789 list_for_each_entry(pch, &ppp->channels, clist) { 1790 if (pch->chan) { 1791 pch->avail = 1; 1792 navail++; 1793 pch->speed = pch->chan->speed; 1794 } else { 1795 pch->avail = 0; 1796 } 1797 if (pch->avail) { 1798 if (skb_queue_empty(&pch->file.xq) || 1799 !pch->had_frag) { 1800 if (pch->speed == 0) 1801 nzero++; 1802 else 1803 totspeed += pch->speed; 1804 1805 pch->avail = 2; 1806 ++nfree; 1807 ++totfree; 1808 } 1809 if (!pch->had_frag && i < ppp->nxchan) 1810 ppp->nxchan = i; 1811 } 1812 ++i; 1813 } 1814 /* 1815 * Don't start sending this packet unless at least half of 1816 * the channels are free. This gives much better TCP 1817 * performance if we have a lot of channels. 1818 */ 1819 if (nfree == 0 || nfree < navail / 2) 1820 return 0; /* can't take now, leave it in xmit_pending */ 1821 1822 /* Do protocol field compression */ 1823 p = skb->data; 1824 len = skb->len; 1825 if (*p == 0 && mp_protocol_compress) { 1826 ++p; 1827 --len; 1828 } 1829 1830 totlen = len; 1831 nbigger = len % nfree; 1832 1833 /* skip to the channel after the one we last used 1834 and start at that one */ 1835 list = &ppp->channels; 1836 for (i = 0; i < ppp->nxchan; ++i) { 1837 list = list->next; 1838 if (list == &ppp->channels) { 1839 i = 0; 1840 break; 1841 } 1842 } 1843 1844 /* create a fragment for each channel */ 1845 bits = B; 1846 while (len > 0) { 1847 list = list->next; 1848 if (list == &ppp->channels) { 1849 i = 0; 1850 continue; 1851 } 1852 pch = list_entry(list, struct channel, clist); 1853 ++i; 1854 if (!pch->avail) 1855 continue; 1856 1857 /* 1858 * Skip this channel if it has a fragment pending already and 1859 * we haven't given a fragment to all of the free channels. 1860 */ 1861 if (pch->avail == 1) { 1862 if (nfree > 0) 1863 continue; 1864 } else { 1865 pch->avail = 1; 1866 } 1867 1868 /* check the channel's mtu and whether it is still attached. */ 1869 spin_lock(&pch->downl); 1870 if (pch->chan == NULL) { 1871 /* can't use this channel, it's being deregistered */ 1872 if (pch->speed == 0) 1873 nzero--; 1874 else 1875 totspeed -= pch->speed; 1876 1877 spin_unlock(&pch->downl); 1878 pch->avail = 0; 1879 totlen = len; 1880 totfree--; 1881 nfree--; 1882 if (--navail == 0) 1883 break; 1884 continue; 1885 } 1886 1887 /* 1888 *if the channel speed is not set divide 1889 *the packet evenly among the free channels; 1890 *otherwise divide it according to the speed 1891 *of the channel we are going to transmit on 1892 */ 1893 flen = len; 1894 if (nfree > 0) { 1895 if (pch->speed == 0) { 1896 flen = len/nfree; 1897 if (nbigger > 0) { 1898 flen++; 1899 nbigger--; 1900 } 1901 } else { 1902 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) / 1903 ((totspeed*totfree)/pch->speed)) - hdrlen; 1904 if (nbigger > 0) { 1905 flen += ((totfree - nzero)*pch->speed)/totspeed; 1906 nbigger -= ((totfree - nzero)*pch->speed)/ 1907 totspeed; 1908 } 1909 } 1910 nfree--; 1911 } 1912 1913 /* 1914 *check if we are on the last channel or 1915 *we exceded the length of the data to 1916 *fragment 1917 */ 1918 if ((nfree <= 0) || (flen > len)) 1919 flen = len; 1920 /* 1921 *it is not worth to tx on slow channels: 1922 *in that case from the resulting flen according to the 1923 *above formula will be equal or less than zero. 1924 *Skip the channel in this case 1925 */ 1926 if (flen <= 0) { 1927 pch->avail = 2; 1928 spin_unlock(&pch->downl); 1929 continue; 1930 } 1931 1932 /* 1933 * hdrlen includes the 2-byte PPP protocol field, but the 1934 * MTU counts only the payload excluding the protocol field. 1935 * (RFC1661 Section 2) 1936 */ 1937 mtu = pch->chan->mtu - (hdrlen - 2); 1938 if (mtu < 4) 1939 mtu = 4; 1940 if (flen > mtu) 1941 flen = mtu; 1942 if (flen == len) 1943 bits |= E; 1944 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC); 1945 if (!frag) 1946 goto noskb; 1947 q = skb_put(frag, flen + hdrlen); 1948 1949 /* make the MP header */ 1950 put_unaligned_be16(PPP_MP, q); 1951 if (ppp->flags & SC_MP_XSHORTSEQ) { 1952 q[2] = bits + ((ppp->nxseq >> 8) & 0xf); 1953 q[3] = ppp->nxseq; 1954 } else { 1955 q[2] = bits; 1956 q[3] = ppp->nxseq >> 16; 1957 q[4] = ppp->nxseq >> 8; 1958 q[5] = ppp->nxseq; 1959 } 1960 1961 memcpy(q + hdrlen, p, flen); 1962 1963 /* try to send it down the channel */ 1964 chan = pch->chan; 1965 if (!skb_queue_empty(&pch->file.xq) || 1966 !chan->ops->start_xmit(chan, frag)) 1967 skb_queue_tail(&pch->file.xq, frag); 1968 pch->had_frag = 1; 1969 p += flen; 1970 len -= flen; 1971 ++ppp->nxseq; 1972 bits = 0; 1973 spin_unlock(&pch->downl); 1974 } 1975 ppp->nxchan = i; 1976 1977 return 1; 1978 1979 noskb: 1980 spin_unlock(&pch->downl); 1981 if (ppp->debug & 1) 1982 netdev_err(ppp->dev, "PPP: no memory (fragment)\n"); 1983 ++ppp->dev->stats.tx_errors; 1984 ++ppp->nxseq; 1985 return 1; /* abandon the frame */ 1986 } 1987 #endif /* CONFIG_PPP_MULTILINK */ 1988 1989 /* Try to send data out on a channel */ 1990 static void __ppp_channel_push(struct channel *pch) 1991 { 1992 struct sk_buff *skb; 1993 struct ppp *ppp; 1994 1995 spin_lock(&pch->downl); 1996 if (pch->chan) { 1997 while (!skb_queue_empty(&pch->file.xq)) { 1998 skb = skb_dequeue(&pch->file.xq); 1999 if (!pch->chan->ops->start_xmit(pch->chan, skb)) { 2000 /* put the packet back and try again later */ 2001 skb_queue_head(&pch->file.xq, skb); 2002 break; 2003 } 2004 } 2005 } else { 2006 /* channel got deregistered */ 2007 skb_queue_purge(&pch->file.xq); 2008 } 2009 spin_unlock(&pch->downl); 2010 /* see if there is anything from the attached unit to be sent */ 2011 if (skb_queue_empty(&pch->file.xq)) { 2012 ppp = pch->ppp; 2013 if (ppp) 2014 __ppp_xmit_process(ppp, NULL); 2015 } 2016 } 2017 2018 static void ppp_channel_push(struct channel *pch) 2019 { 2020 read_lock_bh(&pch->upl); 2021 if (pch->ppp) { 2022 (*this_cpu_ptr(pch->ppp->xmit_recursion))++; 2023 __ppp_channel_push(pch); 2024 (*this_cpu_ptr(pch->ppp->xmit_recursion))--; 2025 } else { 2026 __ppp_channel_push(pch); 2027 } 2028 read_unlock_bh(&pch->upl); 2029 } 2030 2031 /* 2032 * Receive-side routines. 2033 */ 2034 2035 struct ppp_mp_skb_parm { 2036 u32 sequence; 2037 u8 BEbits; 2038 }; 2039 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb)) 2040 2041 static inline void 2042 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2043 { 2044 ppp_recv_lock(ppp); 2045 if (!ppp->closing) 2046 ppp_receive_frame(ppp, skb, pch); 2047 else 2048 kfree_skb(skb); 2049 ppp_recv_unlock(ppp); 2050 } 2051 2052 /** 2053 * __ppp_decompress_proto - Decompress protocol field, slim version. 2054 * @skb: Socket buffer where protocol field should be decompressed. It must have 2055 * at least 1 byte of head room and 1 byte of linear data. First byte of 2056 * data must be a protocol field byte. 2057 * 2058 * Decompress protocol field in PPP header if it's compressed, e.g. when 2059 * Protocol-Field-Compression (PFC) was negotiated. No checks w.r.t. skb data 2060 * length are done in this function. 2061 */ 2062 static void __ppp_decompress_proto(struct sk_buff *skb) 2063 { 2064 if (skb->data[0] & 0x01) 2065 *(u8 *)skb_push(skb, 1) = 0x00; 2066 } 2067 2068 /** 2069 * ppp_decompress_proto - Check skb data room and decompress protocol field. 2070 * @skb: Socket buffer where protocol field should be decompressed. First byte 2071 * of data must be a protocol field byte. 2072 * 2073 * Decompress protocol field in PPP header if it's compressed, e.g. when 2074 * Protocol-Field-Compression (PFC) was negotiated. This function also makes 2075 * sure that skb data room is sufficient for Protocol field, before and after 2076 * decompression. 2077 * 2078 * Return: true - decompressed successfully, false - not enough room in skb. 2079 */ 2080 static bool ppp_decompress_proto(struct sk_buff *skb) 2081 { 2082 /* At least one byte should be present (if protocol is compressed) */ 2083 if (!pskb_may_pull(skb, 1)) 2084 return false; 2085 2086 __ppp_decompress_proto(skb); 2087 2088 /* Protocol field should occupy 2 bytes when not compressed */ 2089 return pskb_may_pull(skb, 2); 2090 } 2091 2092 void 2093 ppp_input(struct ppp_channel *chan, struct sk_buff *skb) 2094 { 2095 struct channel *pch = chan->ppp; 2096 int proto; 2097 2098 if (!pch) { 2099 kfree_skb(skb); 2100 return; 2101 } 2102 2103 read_lock_bh(&pch->upl); 2104 if (!ppp_decompress_proto(skb)) { 2105 kfree_skb(skb); 2106 if (pch->ppp) { 2107 ++pch->ppp->dev->stats.rx_length_errors; 2108 ppp_receive_error(pch->ppp); 2109 } 2110 goto done; 2111 } 2112 2113 proto = PPP_PROTO(skb); 2114 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) { 2115 /* put it on the channel queue */ 2116 skb_queue_tail(&pch->file.rq, skb); 2117 /* drop old frames if queue too long */ 2118 while (pch->file.rq.qlen > PPP_MAX_RQLEN && 2119 (skb = skb_dequeue(&pch->file.rq))) 2120 kfree_skb(skb); 2121 wake_up_interruptible(&pch->file.rwait); 2122 } else { 2123 ppp_do_recv(pch->ppp, skb, pch); 2124 } 2125 2126 done: 2127 read_unlock_bh(&pch->upl); 2128 } 2129 2130 /* Put a 0-length skb in the receive queue as an error indication */ 2131 void 2132 ppp_input_error(struct ppp_channel *chan, int code) 2133 { 2134 struct channel *pch = chan->ppp; 2135 struct sk_buff *skb; 2136 2137 if (!pch) 2138 return; 2139 2140 read_lock_bh(&pch->upl); 2141 if (pch->ppp) { 2142 skb = alloc_skb(0, GFP_ATOMIC); 2143 if (skb) { 2144 skb->len = 0; /* probably unnecessary */ 2145 skb->cb[0] = code; 2146 ppp_do_recv(pch->ppp, skb, pch); 2147 } 2148 } 2149 read_unlock_bh(&pch->upl); 2150 } 2151 2152 /* 2153 * We come in here to process a received frame. 2154 * The receive side of the ppp unit is locked. 2155 */ 2156 static void 2157 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2158 { 2159 /* note: a 0-length skb is used as an error indication */ 2160 if (skb->len > 0) { 2161 skb_checksum_complete_unset(skb); 2162 #ifdef CONFIG_PPP_MULTILINK 2163 /* XXX do channel-level decompression here */ 2164 if (PPP_PROTO(skb) == PPP_MP) 2165 ppp_receive_mp_frame(ppp, skb, pch); 2166 else 2167 #endif /* CONFIG_PPP_MULTILINK */ 2168 ppp_receive_nonmp_frame(ppp, skb); 2169 } else { 2170 kfree_skb(skb); 2171 ppp_receive_error(ppp); 2172 } 2173 } 2174 2175 static void 2176 ppp_receive_error(struct ppp *ppp) 2177 { 2178 ++ppp->dev->stats.rx_errors; 2179 if (ppp->vj) 2180 slhc_toss(ppp->vj); 2181 } 2182 2183 static void 2184 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) 2185 { 2186 struct sk_buff *ns; 2187 int proto, len, npi; 2188 2189 /* 2190 * Decompress the frame, if compressed. 2191 * Note that some decompressors need to see uncompressed frames 2192 * that come in as well as compressed frames. 2193 */ 2194 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) && 2195 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0) 2196 skb = ppp_decompress_frame(ppp, skb); 2197 2198 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR) 2199 goto err; 2200 2201 /* At this point the "Protocol" field MUST be decompressed, either in 2202 * ppp_input(), ppp_decompress_frame() or in ppp_receive_mp_frame(). 2203 */ 2204 proto = PPP_PROTO(skb); 2205 switch (proto) { 2206 case PPP_VJC_COMP: 2207 /* decompress VJ compressed packets */ 2208 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 2209 goto err; 2210 2211 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) { 2212 /* copy to a new sk_buff with more tailroom */ 2213 ns = dev_alloc_skb(skb->len + 128); 2214 if (!ns) { 2215 netdev_err(ppp->dev, "PPP: no memory " 2216 "(VJ decomp)\n"); 2217 goto err; 2218 } 2219 skb_reserve(ns, 2); 2220 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len); 2221 consume_skb(skb); 2222 skb = ns; 2223 } 2224 else 2225 skb->ip_summed = CHECKSUM_NONE; 2226 2227 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2); 2228 if (len <= 0) { 2229 netdev_printk(KERN_DEBUG, ppp->dev, 2230 "PPP: VJ decompression error\n"); 2231 goto err; 2232 } 2233 len += 2; 2234 if (len > skb->len) 2235 skb_put(skb, len - skb->len); 2236 else if (len < skb->len) 2237 skb_trim(skb, len); 2238 proto = PPP_IP; 2239 break; 2240 2241 case PPP_VJC_UNCOMP: 2242 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 2243 goto err; 2244 2245 /* Until we fix the decompressor need to make sure 2246 * data portion is linear. 2247 */ 2248 if (!pskb_may_pull(skb, skb->len)) 2249 goto err; 2250 2251 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) { 2252 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n"); 2253 goto err; 2254 } 2255 proto = PPP_IP; 2256 break; 2257 2258 case PPP_CCP: 2259 ppp_ccp_peek(ppp, skb, 1); 2260 break; 2261 } 2262 2263 ++ppp->stats64.rx_packets; 2264 ppp->stats64.rx_bytes += skb->len - 2; 2265 2266 npi = proto_to_npindex(proto); 2267 if (npi < 0) { 2268 /* control or unknown frame - pass it to pppd */ 2269 skb_queue_tail(&ppp->file.rq, skb); 2270 /* limit queue length by dropping old frames */ 2271 while (ppp->file.rq.qlen > PPP_MAX_RQLEN && 2272 (skb = skb_dequeue(&ppp->file.rq))) 2273 kfree_skb(skb); 2274 /* wake up any process polling or blocking on read */ 2275 wake_up_interruptible(&ppp->file.rwait); 2276 2277 } else { 2278 /* network protocol frame - give it to the kernel */ 2279 2280 #ifdef CONFIG_PPP_FILTER 2281 /* check if the packet passes the pass and active filters */ 2282 /* the filter instructions are constructed assuming 2283 a four-byte PPP header on each packet */ 2284 if (ppp->pass_filter || ppp->active_filter) { 2285 if (skb_unclone(skb, GFP_ATOMIC)) 2286 goto err; 2287 2288 *(u8 *)skb_push(skb, 2) = 0; 2289 if (ppp->pass_filter && 2290 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 2291 if (ppp->debug & 1) 2292 netdev_printk(KERN_DEBUG, ppp->dev, 2293 "PPP: inbound frame " 2294 "not passed\n"); 2295 kfree_skb(skb); 2296 return; 2297 } 2298 if (!(ppp->active_filter && 2299 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 2300 ppp->last_recv = jiffies; 2301 __skb_pull(skb, 2); 2302 } else 2303 #endif /* CONFIG_PPP_FILTER */ 2304 ppp->last_recv = jiffies; 2305 2306 if ((ppp->dev->flags & IFF_UP) == 0 || 2307 ppp->npmode[npi] != NPMODE_PASS) { 2308 kfree_skb(skb); 2309 } else { 2310 /* chop off protocol */ 2311 skb_pull_rcsum(skb, 2); 2312 skb->dev = ppp->dev; 2313 skb->protocol = htons(npindex_to_ethertype[npi]); 2314 skb_reset_mac_header(skb); 2315 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, 2316 dev_net(ppp->dev))); 2317 netif_rx(skb); 2318 } 2319 } 2320 return; 2321 2322 err: 2323 kfree_skb(skb); 2324 ppp_receive_error(ppp); 2325 } 2326 2327 static struct sk_buff * 2328 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb) 2329 { 2330 int proto = PPP_PROTO(skb); 2331 struct sk_buff *ns; 2332 int len; 2333 2334 /* Until we fix all the decompressor's need to make sure 2335 * data portion is linear. 2336 */ 2337 if (!pskb_may_pull(skb, skb->len)) 2338 goto err; 2339 2340 if (proto == PPP_COMP) { 2341 int obuff_size; 2342 2343 switch(ppp->rcomp->compress_proto) { 2344 case CI_MPPE: 2345 obuff_size = ppp->mru + PPP_HDRLEN + 1; 2346 break; 2347 default: 2348 obuff_size = ppp->mru + PPP_HDRLEN; 2349 break; 2350 } 2351 2352 ns = dev_alloc_skb(obuff_size); 2353 if (!ns) { 2354 netdev_err(ppp->dev, "ppp_decompress_frame: " 2355 "no memory\n"); 2356 goto err; 2357 } 2358 /* the decompressor still expects the A/C bytes in the hdr */ 2359 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2, 2360 skb->len + 2, ns->data, obuff_size); 2361 if (len < 0) { 2362 /* Pass the compressed frame to pppd as an 2363 error indication. */ 2364 if (len == DECOMP_FATALERROR) 2365 ppp->rstate |= SC_DC_FERROR; 2366 kfree_skb(ns); 2367 goto err; 2368 } 2369 2370 consume_skb(skb); 2371 skb = ns; 2372 skb_put(skb, len); 2373 skb_pull(skb, 2); /* pull off the A/C bytes */ 2374 2375 /* Don't call __ppp_decompress_proto() here, but instead rely on 2376 * corresponding algo (mppe/bsd/deflate) to decompress it. 2377 */ 2378 } else { 2379 /* Uncompressed frame - pass to decompressor so it 2380 can update its dictionary if necessary. */ 2381 if (ppp->rcomp->incomp) 2382 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2, 2383 skb->len + 2); 2384 } 2385 2386 return skb; 2387 2388 err: 2389 ppp->rstate |= SC_DC_ERROR; 2390 ppp_receive_error(ppp); 2391 return skb; 2392 } 2393 2394 #ifdef CONFIG_PPP_MULTILINK 2395 /* 2396 * Receive a multilink frame. 2397 * We put it on the reconstruction queue and then pull off 2398 * as many completed frames as we can. 2399 */ 2400 static void 2401 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2402 { 2403 u32 mask, seq; 2404 struct channel *ch; 2405 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 2406 2407 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0) 2408 goto err; /* no good, throw it away */ 2409 2410 /* Decode sequence number and begin/end bits */ 2411 if (ppp->flags & SC_MP_SHORTSEQ) { 2412 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3]; 2413 mask = 0xfff; 2414 } else { 2415 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5]; 2416 mask = 0xffffff; 2417 } 2418 PPP_MP_CB(skb)->BEbits = skb->data[2]; 2419 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */ 2420 2421 /* 2422 * Do protocol ID decompression on the first fragment of each packet. 2423 * We have to do that here, because ppp_receive_nonmp_frame() expects 2424 * decompressed protocol field. 2425 */ 2426 if (PPP_MP_CB(skb)->BEbits & B) 2427 __ppp_decompress_proto(skb); 2428 2429 /* 2430 * Expand sequence number to 32 bits, making it as close 2431 * as possible to ppp->minseq. 2432 */ 2433 seq |= ppp->minseq & ~mask; 2434 if ((int)(ppp->minseq - seq) > (int)(mask >> 1)) 2435 seq += mask + 1; 2436 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1)) 2437 seq -= mask + 1; /* should never happen */ 2438 PPP_MP_CB(skb)->sequence = seq; 2439 pch->lastseq = seq; 2440 2441 /* 2442 * If this packet comes before the next one we were expecting, 2443 * drop it. 2444 */ 2445 if (seq_before(seq, ppp->nextseq)) { 2446 kfree_skb(skb); 2447 ++ppp->dev->stats.rx_dropped; 2448 ppp_receive_error(ppp); 2449 return; 2450 } 2451 2452 /* 2453 * Reevaluate minseq, the minimum over all channels of the 2454 * last sequence number received on each channel. Because of 2455 * the increasing sequence number rule, we know that any fragment 2456 * before `minseq' which hasn't arrived is never going to arrive. 2457 * The list of channels can't change because we have the receive 2458 * side of the ppp unit locked. 2459 */ 2460 list_for_each_entry(ch, &ppp->channels, clist) { 2461 if (seq_before(ch->lastseq, seq)) 2462 seq = ch->lastseq; 2463 } 2464 if (seq_before(ppp->minseq, seq)) 2465 ppp->minseq = seq; 2466 2467 /* Put the fragment on the reconstruction queue */ 2468 ppp_mp_insert(ppp, skb); 2469 2470 /* If the queue is getting long, don't wait any longer for packets 2471 before the start of the queue. */ 2472 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) { 2473 struct sk_buff *mskb = skb_peek(&ppp->mrq); 2474 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence)) 2475 ppp->minseq = PPP_MP_CB(mskb)->sequence; 2476 } 2477 2478 /* Pull completed packets off the queue and receive them. */ 2479 while ((skb = ppp_mp_reconstruct(ppp))) { 2480 if (pskb_may_pull(skb, 2)) 2481 ppp_receive_nonmp_frame(ppp, skb); 2482 else { 2483 ++ppp->dev->stats.rx_length_errors; 2484 kfree_skb(skb); 2485 ppp_receive_error(ppp); 2486 } 2487 } 2488 2489 return; 2490 2491 err: 2492 kfree_skb(skb); 2493 ppp_receive_error(ppp); 2494 } 2495 2496 /* 2497 * Insert a fragment on the MP reconstruction queue. 2498 * The queue is ordered by increasing sequence number. 2499 */ 2500 static void 2501 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb) 2502 { 2503 struct sk_buff *p; 2504 struct sk_buff_head *list = &ppp->mrq; 2505 u32 seq = PPP_MP_CB(skb)->sequence; 2506 2507 /* N.B. we don't need to lock the list lock because we have the 2508 ppp unit receive-side lock. */ 2509 skb_queue_walk(list, p) { 2510 if (seq_before(seq, PPP_MP_CB(p)->sequence)) 2511 break; 2512 } 2513 __skb_queue_before(list, p, skb); 2514 } 2515 2516 /* 2517 * Reconstruct a packet from the MP fragment queue. 2518 * We go through increasing sequence numbers until we find a 2519 * complete packet, or we get to the sequence number for a fragment 2520 * which hasn't arrived but might still do so. 2521 */ 2522 static struct sk_buff * 2523 ppp_mp_reconstruct(struct ppp *ppp) 2524 { 2525 u32 seq = ppp->nextseq; 2526 u32 minseq = ppp->minseq; 2527 struct sk_buff_head *list = &ppp->mrq; 2528 struct sk_buff *p, *tmp; 2529 struct sk_buff *head, *tail; 2530 struct sk_buff *skb = NULL; 2531 int lost = 0, len = 0; 2532 2533 if (ppp->mrru == 0) /* do nothing until mrru is set */ 2534 return NULL; 2535 head = __skb_peek(list); 2536 tail = NULL; 2537 skb_queue_walk_safe(list, p, tmp) { 2538 again: 2539 if (seq_before(PPP_MP_CB(p)->sequence, seq)) { 2540 /* this can't happen, anyway ignore the skb */ 2541 netdev_err(ppp->dev, "ppp_mp_reconstruct bad " 2542 "seq %u < %u\n", 2543 PPP_MP_CB(p)->sequence, seq); 2544 __skb_unlink(p, list); 2545 kfree_skb(p); 2546 continue; 2547 } 2548 if (PPP_MP_CB(p)->sequence != seq) { 2549 u32 oldseq; 2550 /* Fragment `seq' is missing. If it is after 2551 minseq, it might arrive later, so stop here. */ 2552 if (seq_after(seq, minseq)) 2553 break; 2554 /* Fragment `seq' is lost, keep going. */ 2555 lost = 1; 2556 oldseq = seq; 2557 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)? 2558 minseq + 1: PPP_MP_CB(p)->sequence; 2559 2560 if (ppp->debug & 1) 2561 netdev_printk(KERN_DEBUG, ppp->dev, 2562 "lost frag %u..%u\n", 2563 oldseq, seq-1); 2564 2565 goto again; 2566 } 2567 2568 /* 2569 * At this point we know that all the fragments from 2570 * ppp->nextseq to seq are either present or lost. 2571 * Also, there are no complete packets in the queue 2572 * that have no missing fragments and end before this 2573 * fragment. 2574 */ 2575 2576 /* B bit set indicates this fragment starts a packet */ 2577 if (PPP_MP_CB(p)->BEbits & B) { 2578 head = p; 2579 lost = 0; 2580 len = 0; 2581 } 2582 2583 len += p->len; 2584 2585 /* Got a complete packet yet? */ 2586 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) && 2587 (PPP_MP_CB(head)->BEbits & B)) { 2588 if (len > ppp->mrru + 2) { 2589 ++ppp->dev->stats.rx_length_errors; 2590 netdev_printk(KERN_DEBUG, ppp->dev, 2591 "PPP: reconstructed packet" 2592 " is too long (%d)\n", len); 2593 } else { 2594 tail = p; 2595 break; 2596 } 2597 ppp->nextseq = seq + 1; 2598 } 2599 2600 /* 2601 * If this is the ending fragment of a packet, 2602 * and we haven't found a complete valid packet yet, 2603 * we can discard up to and including this fragment. 2604 */ 2605 if (PPP_MP_CB(p)->BEbits & E) { 2606 struct sk_buff *tmp2; 2607 2608 skb_queue_reverse_walk_from_safe(list, p, tmp2) { 2609 if (ppp->debug & 1) 2610 netdev_printk(KERN_DEBUG, ppp->dev, 2611 "discarding frag %u\n", 2612 PPP_MP_CB(p)->sequence); 2613 __skb_unlink(p, list); 2614 kfree_skb(p); 2615 } 2616 head = skb_peek(list); 2617 if (!head) 2618 break; 2619 } 2620 ++seq; 2621 } 2622 2623 /* If we have a complete packet, copy it all into one skb. */ 2624 if (tail != NULL) { 2625 /* If we have discarded any fragments, 2626 signal a receive error. */ 2627 if (PPP_MP_CB(head)->sequence != ppp->nextseq) { 2628 skb_queue_walk_safe(list, p, tmp) { 2629 if (p == head) 2630 break; 2631 if (ppp->debug & 1) 2632 netdev_printk(KERN_DEBUG, ppp->dev, 2633 "discarding frag %u\n", 2634 PPP_MP_CB(p)->sequence); 2635 __skb_unlink(p, list); 2636 kfree_skb(p); 2637 } 2638 2639 if (ppp->debug & 1) 2640 netdev_printk(KERN_DEBUG, ppp->dev, 2641 " missed pkts %u..%u\n", 2642 ppp->nextseq, 2643 PPP_MP_CB(head)->sequence-1); 2644 ++ppp->dev->stats.rx_dropped; 2645 ppp_receive_error(ppp); 2646 } 2647 2648 skb = head; 2649 if (head != tail) { 2650 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list; 2651 p = skb_queue_next(list, head); 2652 __skb_unlink(skb, list); 2653 skb_queue_walk_from_safe(list, p, tmp) { 2654 __skb_unlink(p, list); 2655 *fragpp = p; 2656 p->next = NULL; 2657 fragpp = &p->next; 2658 2659 skb->len += p->len; 2660 skb->data_len += p->len; 2661 skb->truesize += p->truesize; 2662 2663 if (p == tail) 2664 break; 2665 } 2666 } else { 2667 __skb_unlink(skb, list); 2668 } 2669 2670 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1; 2671 } 2672 2673 return skb; 2674 } 2675 #endif /* CONFIG_PPP_MULTILINK */ 2676 2677 /* 2678 * Channel interface. 2679 */ 2680 2681 /* Create a new, unattached ppp channel. */ 2682 int ppp_register_channel(struct ppp_channel *chan) 2683 { 2684 return ppp_register_net_channel(current->nsproxy->net_ns, chan); 2685 } 2686 2687 /* Create a new, unattached ppp channel for specified net. */ 2688 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan) 2689 { 2690 struct channel *pch; 2691 struct ppp_net *pn; 2692 2693 pch = kzalloc(sizeof(struct channel), GFP_KERNEL); 2694 if (!pch) 2695 return -ENOMEM; 2696 2697 pn = ppp_pernet(net); 2698 2699 pch->ppp = NULL; 2700 pch->chan = chan; 2701 pch->chan_net = get_net(net); 2702 chan->ppp = pch; 2703 init_ppp_file(&pch->file, CHANNEL); 2704 pch->file.hdrlen = chan->hdrlen; 2705 #ifdef CONFIG_PPP_MULTILINK 2706 pch->lastseq = -1; 2707 #endif /* CONFIG_PPP_MULTILINK */ 2708 init_rwsem(&pch->chan_sem); 2709 spin_lock_init(&pch->downl); 2710 rwlock_init(&pch->upl); 2711 2712 spin_lock_bh(&pn->all_channels_lock); 2713 pch->file.index = ++pn->last_channel_index; 2714 list_add(&pch->list, &pn->new_channels); 2715 atomic_inc(&channel_count); 2716 spin_unlock_bh(&pn->all_channels_lock); 2717 2718 return 0; 2719 } 2720 2721 /* 2722 * Return the index of a channel. 2723 */ 2724 int ppp_channel_index(struct ppp_channel *chan) 2725 { 2726 struct channel *pch = chan->ppp; 2727 2728 if (pch) 2729 return pch->file.index; 2730 return -1; 2731 } 2732 2733 /* 2734 * Return the PPP unit number to which a channel is connected. 2735 */ 2736 int ppp_unit_number(struct ppp_channel *chan) 2737 { 2738 struct channel *pch = chan->ppp; 2739 int unit = -1; 2740 2741 if (pch) { 2742 read_lock_bh(&pch->upl); 2743 if (pch->ppp) 2744 unit = pch->ppp->file.index; 2745 read_unlock_bh(&pch->upl); 2746 } 2747 return unit; 2748 } 2749 2750 /* 2751 * Return the PPP device interface name of a channel. 2752 */ 2753 char *ppp_dev_name(struct ppp_channel *chan) 2754 { 2755 struct channel *pch = chan->ppp; 2756 char *name = NULL; 2757 2758 if (pch) { 2759 read_lock_bh(&pch->upl); 2760 if (pch->ppp && pch->ppp->dev) 2761 name = pch->ppp->dev->name; 2762 read_unlock_bh(&pch->upl); 2763 } 2764 return name; 2765 } 2766 2767 2768 /* 2769 * Disconnect a channel from the generic layer. 2770 * This must be called in process context. 2771 */ 2772 void 2773 ppp_unregister_channel(struct ppp_channel *chan) 2774 { 2775 struct channel *pch = chan->ppp; 2776 struct ppp_net *pn; 2777 2778 if (!pch) 2779 return; /* should never happen */ 2780 2781 chan->ppp = NULL; 2782 2783 /* 2784 * This ensures that we have returned from any calls into the 2785 * the channel's start_xmit or ioctl routine before we proceed. 2786 */ 2787 down_write(&pch->chan_sem); 2788 spin_lock_bh(&pch->downl); 2789 pch->chan = NULL; 2790 spin_unlock_bh(&pch->downl); 2791 up_write(&pch->chan_sem); 2792 ppp_disconnect_channel(pch); 2793 2794 pn = ppp_pernet(pch->chan_net); 2795 spin_lock_bh(&pn->all_channels_lock); 2796 list_del(&pch->list); 2797 spin_unlock_bh(&pn->all_channels_lock); 2798 2799 pch->file.dead = 1; 2800 wake_up_interruptible(&pch->file.rwait); 2801 if (refcount_dec_and_test(&pch->file.refcnt)) 2802 ppp_destroy_channel(pch); 2803 } 2804 2805 /* 2806 * Callback from a channel when it can accept more to transmit. 2807 * This should be called at BH/softirq level, not interrupt level. 2808 */ 2809 void 2810 ppp_output_wakeup(struct ppp_channel *chan) 2811 { 2812 struct channel *pch = chan->ppp; 2813 2814 if (!pch) 2815 return; 2816 ppp_channel_push(pch); 2817 } 2818 2819 /* 2820 * Compression control. 2821 */ 2822 2823 /* Process the PPPIOCSCOMPRESS ioctl. */ 2824 static int 2825 ppp_set_compress(struct ppp *ppp, struct ppp_option_data *data) 2826 { 2827 int err = -EFAULT; 2828 struct compressor *cp, *ocomp; 2829 void *state, *ostate; 2830 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH]; 2831 2832 if (data->length > CCP_MAX_OPTION_LENGTH) 2833 goto out; 2834 if (copy_from_user(ccp_option, data->ptr, data->length)) 2835 goto out; 2836 2837 err = -EINVAL; 2838 if (data->length < 2 || ccp_option[1] < 2 || ccp_option[1] > data->length) 2839 goto out; 2840 2841 cp = try_then_request_module( 2842 find_compressor(ccp_option[0]), 2843 "ppp-compress-%d", ccp_option[0]); 2844 if (!cp) 2845 goto out; 2846 2847 err = -ENOBUFS; 2848 if (data->transmit) { 2849 state = cp->comp_alloc(ccp_option, data->length); 2850 if (state) { 2851 ppp_xmit_lock(ppp); 2852 ppp->xstate &= ~SC_COMP_RUN; 2853 ocomp = ppp->xcomp; 2854 ostate = ppp->xc_state; 2855 ppp->xcomp = cp; 2856 ppp->xc_state = state; 2857 ppp_xmit_unlock(ppp); 2858 if (ostate) { 2859 ocomp->comp_free(ostate); 2860 module_put(ocomp->owner); 2861 } 2862 err = 0; 2863 } else 2864 module_put(cp->owner); 2865 2866 } else { 2867 state = cp->decomp_alloc(ccp_option, data->length); 2868 if (state) { 2869 ppp_recv_lock(ppp); 2870 ppp->rstate &= ~SC_DECOMP_RUN; 2871 ocomp = ppp->rcomp; 2872 ostate = ppp->rc_state; 2873 ppp->rcomp = cp; 2874 ppp->rc_state = state; 2875 ppp_recv_unlock(ppp); 2876 if (ostate) { 2877 ocomp->decomp_free(ostate); 2878 module_put(ocomp->owner); 2879 } 2880 err = 0; 2881 } else 2882 module_put(cp->owner); 2883 } 2884 2885 out: 2886 return err; 2887 } 2888 2889 /* 2890 * Look at a CCP packet and update our state accordingly. 2891 * We assume the caller has the xmit or recv path locked. 2892 */ 2893 static void 2894 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound) 2895 { 2896 unsigned char *dp; 2897 int len; 2898 2899 if (!pskb_may_pull(skb, CCP_HDRLEN + 2)) 2900 return; /* no header */ 2901 dp = skb->data + 2; 2902 2903 switch (CCP_CODE(dp)) { 2904 case CCP_CONFREQ: 2905 2906 /* A ConfReq starts negotiation of compression 2907 * in one direction of transmission, 2908 * and hence brings it down...but which way? 2909 * 2910 * Remember: 2911 * A ConfReq indicates what the sender would like to receive 2912 */ 2913 if(inbound) 2914 /* He is proposing what I should send */ 2915 ppp->xstate &= ~SC_COMP_RUN; 2916 else 2917 /* I am proposing to what he should send */ 2918 ppp->rstate &= ~SC_DECOMP_RUN; 2919 2920 break; 2921 2922 case CCP_TERMREQ: 2923 case CCP_TERMACK: 2924 /* 2925 * CCP is going down, both directions of transmission 2926 */ 2927 ppp->rstate &= ~SC_DECOMP_RUN; 2928 ppp->xstate &= ~SC_COMP_RUN; 2929 break; 2930 2931 case CCP_CONFACK: 2932 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN) 2933 break; 2934 len = CCP_LENGTH(dp); 2935 if (!pskb_may_pull(skb, len + 2)) 2936 return; /* too short */ 2937 dp += CCP_HDRLEN; 2938 len -= CCP_HDRLEN; 2939 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp)) 2940 break; 2941 if (inbound) { 2942 /* we will start receiving compressed packets */ 2943 if (!ppp->rc_state) 2944 break; 2945 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len, 2946 ppp->file.index, 0, ppp->mru, ppp->debug)) { 2947 ppp->rstate |= SC_DECOMP_RUN; 2948 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR); 2949 } 2950 } else { 2951 /* we will soon start sending compressed packets */ 2952 if (!ppp->xc_state) 2953 break; 2954 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len, 2955 ppp->file.index, 0, ppp->debug)) 2956 ppp->xstate |= SC_COMP_RUN; 2957 } 2958 break; 2959 2960 case CCP_RESETACK: 2961 /* reset the [de]compressor */ 2962 if ((ppp->flags & SC_CCP_UP) == 0) 2963 break; 2964 if (inbound) { 2965 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) { 2966 ppp->rcomp->decomp_reset(ppp->rc_state); 2967 ppp->rstate &= ~SC_DC_ERROR; 2968 } 2969 } else { 2970 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN)) 2971 ppp->xcomp->comp_reset(ppp->xc_state); 2972 } 2973 break; 2974 } 2975 } 2976 2977 /* Free up compression resources. */ 2978 static void 2979 ppp_ccp_closed(struct ppp *ppp) 2980 { 2981 void *xstate, *rstate; 2982 struct compressor *xcomp, *rcomp; 2983 2984 ppp_lock(ppp); 2985 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP); 2986 ppp->xstate = 0; 2987 xcomp = ppp->xcomp; 2988 xstate = ppp->xc_state; 2989 ppp->xc_state = NULL; 2990 ppp->rstate = 0; 2991 rcomp = ppp->rcomp; 2992 rstate = ppp->rc_state; 2993 ppp->rc_state = NULL; 2994 ppp_unlock(ppp); 2995 2996 if (xstate) { 2997 xcomp->comp_free(xstate); 2998 module_put(xcomp->owner); 2999 } 3000 if (rstate) { 3001 rcomp->decomp_free(rstate); 3002 module_put(rcomp->owner); 3003 } 3004 } 3005 3006 /* List of compressors. */ 3007 static LIST_HEAD(compressor_list); 3008 static DEFINE_SPINLOCK(compressor_list_lock); 3009 3010 struct compressor_entry { 3011 struct list_head list; 3012 struct compressor *comp; 3013 }; 3014 3015 static struct compressor_entry * 3016 find_comp_entry(int proto) 3017 { 3018 struct compressor_entry *ce; 3019 3020 list_for_each_entry(ce, &compressor_list, list) { 3021 if (ce->comp->compress_proto == proto) 3022 return ce; 3023 } 3024 return NULL; 3025 } 3026 3027 /* Register a compressor */ 3028 int 3029 ppp_register_compressor(struct compressor *cp) 3030 { 3031 struct compressor_entry *ce; 3032 int ret; 3033 spin_lock(&compressor_list_lock); 3034 ret = -EEXIST; 3035 if (find_comp_entry(cp->compress_proto)) 3036 goto out; 3037 ret = -ENOMEM; 3038 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC); 3039 if (!ce) 3040 goto out; 3041 ret = 0; 3042 ce->comp = cp; 3043 list_add(&ce->list, &compressor_list); 3044 out: 3045 spin_unlock(&compressor_list_lock); 3046 return ret; 3047 } 3048 3049 /* Unregister a compressor */ 3050 void 3051 ppp_unregister_compressor(struct compressor *cp) 3052 { 3053 struct compressor_entry *ce; 3054 3055 spin_lock(&compressor_list_lock); 3056 ce = find_comp_entry(cp->compress_proto); 3057 if (ce && ce->comp == cp) { 3058 list_del(&ce->list); 3059 kfree(ce); 3060 } 3061 spin_unlock(&compressor_list_lock); 3062 } 3063 3064 /* Find a compressor. */ 3065 static struct compressor * 3066 find_compressor(int type) 3067 { 3068 struct compressor_entry *ce; 3069 struct compressor *cp = NULL; 3070 3071 spin_lock(&compressor_list_lock); 3072 ce = find_comp_entry(type); 3073 if (ce) { 3074 cp = ce->comp; 3075 if (!try_module_get(cp->owner)) 3076 cp = NULL; 3077 } 3078 spin_unlock(&compressor_list_lock); 3079 return cp; 3080 } 3081 3082 /* 3083 * Miscelleneous stuff. 3084 */ 3085 3086 static void 3087 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st) 3088 { 3089 struct slcompress *vj = ppp->vj; 3090 3091 memset(st, 0, sizeof(*st)); 3092 st->p.ppp_ipackets = ppp->stats64.rx_packets; 3093 st->p.ppp_ierrors = ppp->dev->stats.rx_errors; 3094 st->p.ppp_ibytes = ppp->stats64.rx_bytes; 3095 st->p.ppp_opackets = ppp->stats64.tx_packets; 3096 st->p.ppp_oerrors = ppp->dev->stats.tx_errors; 3097 st->p.ppp_obytes = ppp->stats64.tx_bytes; 3098 if (!vj) 3099 return; 3100 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed; 3101 st->vj.vjs_compressed = vj->sls_o_compressed; 3102 st->vj.vjs_searches = vj->sls_o_searches; 3103 st->vj.vjs_misses = vj->sls_o_misses; 3104 st->vj.vjs_errorin = vj->sls_i_error; 3105 st->vj.vjs_tossed = vj->sls_i_tossed; 3106 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed; 3107 st->vj.vjs_compressedin = vj->sls_i_compressed; 3108 } 3109 3110 /* 3111 * Stuff for handling the lists of ppp units and channels 3112 * and for initialization. 3113 */ 3114 3115 /* 3116 * Create a new ppp interface unit. Fails if it can't allocate memory 3117 * or if there is already a unit with the requested number. 3118 * unit == -1 means allocate a new number. 3119 */ 3120 static int ppp_create_interface(struct net *net, struct file *file, int *unit) 3121 { 3122 struct ppp_config conf = { 3123 .file = file, 3124 .unit = *unit, 3125 .ifname_is_set = false, 3126 }; 3127 struct net_device *dev; 3128 struct ppp *ppp; 3129 int err; 3130 3131 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup); 3132 if (!dev) { 3133 err = -ENOMEM; 3134 goto err; 3135 } 3136 dev_net_set(dev, net); 3137 dev->rtnl_link_ops = &ppp_link_ops; 3138 3139 rtnl_lock(); 3140 3141 err = ppp_dev_configure(net, dev, &conf); 3142 if (err < 0) 3143 goto err_dev; 3144 ppp = netdev_priv(dev); 3145 *unit = ppp->file.index; 3146 3147 rtnl_unlock(); 3148 3149 return 0; 3150 3151 err_dev: 3152 rtnl_unlock(); 3153 free_netdev(dev); 3154 err: 3155 return err; 3156 } 3157 3158 /* 3159 * Initialize a ppp_file structure. 3160 */ 3161 static void 3162 init_ppp_file(struct ppp_file *pf, int kind) 3163 { 3164 pf->kind = kind; 3165 skb_queue_head_init(&pf->xq); 3166 skb_queue_head_init(&pf->rq); 3167 refcount_set(&pf->refcnt, 1); 3168 init_waitqueue_head(&pf->rwait); 3169 } 3170 3171 /* 3172 * Free the memory used by a ppp unit. This is only called once 3173 * there are no channels connected to the unit and no file structs 3174 * that reference the unit. 3175 */ 3176 static void ppp_destroy_interface(struct ppp *ppp) 3177 { 3178 atomic_dec(&ppp_unit_count); 3179 3180 if (!ppp->file.dead || ppp->n_channels) { 3181 /* "can't happen" */ 3182 netdev_err(ppp->dev, "ppp: destroying ppp struct %p " 3183 "but dead=%d n_channels=%d !\n", 3184 ppp, ppp->file.dead, ppp->n_channels); 3185 return; 3186 } 3187 3188 ppp_ccp_closed(ppp); 3189 if (ppp->vj) { 3190 slhc_free(ppp->vj); 3191 ppp->vj = NULL; 3192 } 3193 skb_queue_purge(&ppp->file.xq); 3194 skb_queue_purge(&ppp->file.rq); 3195 #ifdef CONFIG_PPP_MULTILINK 3196 skb_queue_purge(&ppp->mrq); 3197 #endif /* CONFIG_PPP_MULTILINK */ 3198 #ifdef CONFIG_PPP_FILTER 3199 if (ppp->pass_filter) { 3200 bpf_prog_destroy(ppp->pass_filter); 3201 ppp->pass_filter = NULL; 3202 } 3203 3204 if (ppp->active_filter) { 3205 bpf_prog_destroy(ppp->active_filter); 3206 ppp->active_filter = NULL; 3207 } 3208 #endif /* CONFIG_PPP_FILTER */ 3209 3210 kfree_skb(ppp->xmit_pending); 3211 free_percpu(ppp->xmit_recursion); 3212 3213 free_netdev(ppp->dev); 3214 } 3215 3216 /* 3217 * Locate an existing ppp unit. 3218 * The caller should have locked the all_ppp_mutex. 3219 */ 3220 static struct ppp * 3221 ppp_find_unit(struct ppp_net *pn, int unit) 3222 { 3223 return unit_find(&pn->units_idr, unit); 3224 } 3225 3226 /* 3227 * Locate an existing ppp channel. 3228 * The caller should have locked the all_channels_lock. 3229 * First we look in the new_channels list, then in the 3230 * all_channels list. If found in the new_channels list, 3231 * we move it to the all_channels list. This is for speed 3232 * when we have a lot of channels in use. 3233 */ 3234 static struct channel * 3235 ppp_find_channel(struct ppp_net *pn, int unit) 3236 { 3237 struct channel *pch; 3238 3239 list_for_each_entry(pch, &pn->new_channels, list) { 3240 if (pch->file.index == unit) { 3241 list_move(&pch->list, &pn->all_channels); 3242 return pch; 3243 } 3244 } 3245 3246 list_for_each_entry(pch, &pn->all_channels, list) { 3247 if (pch->file.index == unit) 3248 return pch; 3249 } 3250 3251 return NULL; 3252 } 3253 3254 /* 3255 * Connect a PPP channel to a PPP interface unit. 3256 */ 3257 static int 3258 ppp_connect_channel(struct channel *pch, int unit) 3259 { 3260 struct ppp *ppp; 3261 struct ppp_net *pn; 3262 int ret = -ENXIO; 3263 int hdrlen; 3264 3265 pn = ppp_pernet(pch->chan_net); 3266 3267 mutex_lock(&pn->all_ppp_mutex); 3268 ppp = ppp_find_unit(pn, unit); 3269 if (!ppp) 3270 goto out; 3271 write_lock_bh(&pch->upl); 3272 ret = -EINVAL; 3273 if (pch->ppp) 3274 goto outl; 3275 3276 ppp_lock(ppp); 3277 spin_lock_bh(&pch->downl); 3278 if (!pch->chan) { 3279 /* Don't connect unregistered channels */ 3280 spin_unlock_bh(&pch->downl); 3281 ppp_unlock(ppp); 3282 ret = -ENOTCONN; 3283 goto outl; 3284 } 3285 spin_unlock_bh(&pch->downl); 3286 if (pch->file.hdrlen > ppp->file.hdrlen) 3287 ppp->file.hdrlen = pch->file.hdrlen; 3288 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */ 3289 if (hdrlen > ppp->dev->hard_header_len) 3290 ppp->dev->hard_header_len = hdrlen; 3291 list_add_tail(&pch->clist, &ppp->channels); 3292 ++ppp->n_channels; 3293 pch->ppp = ppp; 3294 refcount_inc(&ppp->file.refcnt); 3295 ppp_unlock(ppp); 3296 ret = 0; 3297 3298 outl: 3299 write_unlock_bh(&pch->upl); 3300 out: 3301 mutex_unlock(&pn->all_ppp_mutex); 3302 return ret; 3303 } 3304 3305 /* 3306 * Disconnect a channel from its ppp unit. 3307 */ 3308 static int 3309 ppp_disconnect_channel(struct channel *pch) 3310 { 3311 struct ppp *ppp; 3312 int err = -EINVAL; 3313 3314 write_lock_bh(&pch->upl); 3315 ppp = pch->ppp; 3316 pch->ppp = NULL; 3317 write_unlock_bh(&pch->upl); 3318 if (ppp) { 3319 /* remove it from the ppp unit's list */ 3320 ppp_lock(ppp); 3321 list_del(&pch->clist); 3322 if (--ppp->n_channels == 0) 3323 wake_up_interruptible(&ppp->file.rwait); 3324 ppp_unlock(ppp); 3325 if (refcount_dec_and_test(&ppp->file.refcnt)) 3326 ppp_destroy_interface(ppp); 3327 err = 0; 3328 } 3329 return err; 3330 } 3331 3332 /* 3333 * Free up the resources used by a ppp channel. 3334 */ 3335 static void ppp_destroy_channel(struct channel *pch) 3336 { 3337 put_net(pch->chan_net); 3338 pch->chan_net = NULL; 3339 3340 atomic_dec(&channel_count); 3341 3342 if (!pch->file.dead) { 3343 /* "can't happen" */ 3344 pr_err("ppp: destroying undead channel %p !\n", pch); 3345 return; 3346 } 3347 skb_queue_purge(&pch->file.xq); 3348 skb_queue_purge(&pch->file.rq); 3349 kfree(pch); 3350 } 3351 3352 static void __exit ppp_cleanup(void) 3353 { 3354 /* should never happen */ 3355 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count)) 3356 pr_err("PPP: removing module but units remain!\n"); 3357 rtnl_link_unregister(&ppp_link_ops); 3358 unregister_chrdev(PPP_MAJOR, "ppp"); 3359 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0)); 3360 class_destroy(ppp_class); 3361 unregister_pernet_device(&ppp_net_ops); 3362 } 3363 3364 /* 3365 * Units handling. Caller must protect concurrent access 3366 * by holding all_ppp_mutex 3367 */ 3368 3369 /* associate pointer with specified number */ 3370 static int unit_set(struct idr *p, void *ptr, int n) 3371 { 3372 int unit; 3373 3374 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL); 3375 if (unit == -ENOSPC) 3376 unit = -EINVAL; 3377 return unit; 3378 } 3379 3380 /* get new free unit number and associate pointer with it */ 3381 static int unit_get(struct idr *p, void *ptr) 3382 { 3383 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL); 3384 } 3385 3386 /* put unit number back to a pool */ 3387 static void unit_put(struct idr *p, int n) 3388 { 3389 idr_remove(p, n); 3390 } 3391 3392 /* get pointer associated with the number */ 3393 static void *unit_find(struct idr *p, int n) 3394 { 3395 return idr_find(p, n); 3396 } 3397 3398 /* Module/initialization stuff */ 3399 3400 module_init(ppp_init); 3401 module_exit(ppp_cleanup); 3402 3403 EXPORT_SYMBOL(ppp_register_net_channel); 3404 EXPORT_SYMBOL(ppp_register_channel); 3405 EXPORT_SYMBOL(ppp_unregister_channel); 3406 EXPORT_SYMBOL(ppp_channel_index); 3407 EXPORT_SYMBOL(ppp_unit_number); 3408 EXPORT_SYMBOL(ppp_dev_name); 3409 EXPORT_SYMBOL(ppp_input); 3410 EXPORT_SYMBOL(ppp_input_error); 3411 EXPORT_SYMBOL(ppp_output_wakeup); 3412 EXPORT_SYMBOL(ppp_register_compressor); 3413 EXPORT_SYMBOL(ppp_unregister_compressor); 3414 MODULE_LICENSE("GPL"); 3415 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0); 3416 MODULE_ALIAS_RTNL_LINK("ppp"); 3417 MODULE_ALIAS("devname:ppp"); 3418