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