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