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