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 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 err = ppp_dev_configure(src_net, dev, &conf); 1107 1108 out_unlock: 1109 mutex_unlock(&ppp_mutex); 1110 out: 1111 fput(file); 1112 1113 return err; 1114 } 1115 1116 static void ppp_nl_dellink(struct net_device *dev, struct list_head *head) 1117 { 1118 unregister_netdevice_queue(dev, head); 1119 } 1120 1121 static size_t ppp_nl_get_size(const struct net_device *dev) 1122 { 1123 return 0; 1124 } 1125 1126 static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev) 1127 { 1128 return 0; 1129 } 1130 1131 static struct net *ppp_nl_get_link_net(const struct net_device *dev) 1132 { 1133 struct ppp *ppp = netdev_priv(dev); 1134 1135 return ppp->ppp_net; 1136 } 1137 1138 static struct rtnl_link_ops ppp_link_ops __read_mostly = { 1139 .kind = "ppp", 1140 .maxtype = IFLA_PPP_MAX, 1141 .policy = ppp_nl_policy, 1142 .priv_size = sizeof(struct ppp), 1143 .setup = ppp_setup, 1144 .validate = ppp_nl_validate, 1145 .newlink = ppp_nl_newlink, 1146 .dellink = ppp_nl_dellink, 1147 .get_size = ppp_nl_get_size, 1148 .fill_info = ppp_nl_fill_info, 1149 .get_link_net = ppp_nl_get_link_net, 1150 }; 1151 1152 #define PPP_MAJOR 108 1153 1154 /* Called at boot time if ppp is compiled into the kernel, 1155 or at module load time (from init_module) if compiled as a module. */ 1156 static int __init ppp_init(void) 1157 { 1158 int err; 1159 1160 pr_info("PPP generic driver version " PPP_VERSION "\n"); 1161 1162 err = register_pernet_device(&ppp_net_ops); 1163 if (err) { 1164 pr_err("failed to register PPP pernet device (%d)\n", err); 1165 goto out; 1166 } 1167 1168 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops); 1169 if (err) { 1170 pr_err("failed to register PPP device (%d)\n", err); 1171 goto out_net; 1172 } 1173 1174 ppp_class = class_create(THIS_MODULE, "ppp"); 1175 if (IS_ERR(ppp_class)) { 1176 err = PTR_ERR(ppp_class); 1177 goto out_chrdev; 1178 } 1179 1180 err = rtnl_link_register(&ppp_link_ops); 1181 if (err) { 1182 pr_err("failed to register rtnetlink PPP handler\n"); 1183 goto out_class; 1184 } 1185 1186 /* not a big deal if we fail here :-) */ 1187 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp"); 1188 1189 return 0; 1190 1191 out_class: 1192 class_destroy(ppp_class); 1193 out_chrdev: 1194 unregister_chrdev(PPP_MAJOR, "ppp"); 1195 out_net: 1196 unregister_pernet_device(&ppp_net_ops); 1197 out: 1198 return err; 1199 } 1200 1201 /* 1202 * Network interface unit routines. 1203 */ 1204 static netdev_tx_t 1205 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev) 1206 { 1207 struct ppp *ppp = netdev_priv(dev); 1208 int npi, proto; 1209 unsigned char *pp; 1210 1211 npi = ethertype_to_npindex(ntohs(skb->protocol)); 1212 if (npi < 0) 1213 goto outf; 1214 1215 /* Drop, accept or reject the packet */ 1216 switch (ppp->npmode[npi]) { 1217 case NPMODE_PASS: 1218 break; 1219 case NPMODE_QUEUE: 1220 /* it would be nice to have a way to tell the network 1221 system to queue this one up for later. */ 1222 goto outf; 1223 case NPMODE_DROP: 1224 case NPMODE_ERROR: 1225 goto outf; 1226 } 1227 1228 /* Put the 2-byte PPP protocol number on the front, 1229 making sure there is room for the address and control fields. */ 1230 if (skb_cow_head(skb, PPP_HDRLEN)) 1231 goto outf; 1232 1233 pp = skb_push(skb, 2); 1234 proto = npindex_to_proto[npi]; 1235 put_unaligned_be16(proto, pp); 1236 1237 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev))); 1238 skb_queue_tail(&ppp->file.xq, skb); 1239 ppp_xmit_process(ppp); 1240 return NETDEV_TX_OK; 1241 1242 outf: 1243 kfree_skb(skb); 1244 ++dev->stats.tx_dropped; 1245 return NETDEV_TX_OK; 1246 } 1247 1248 static int 1249 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 1250 { 1251 struct ppp *ppp = netdev_priv(dev); 1252 int err = -EFAULT; 1253 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data; 1254 struct ppp_stats stats; 1255 struct ppp_comp_stats cstats; 1256 char *vers; 1257 1258 switch (cmd) { 1259 case SIOCGPPPSTATS: 1260 ppp_get_stats(ppp, &stats); 1261 if (copy_to_user(addr, &stats, sizeof(stats))) 1262 break; 1263 err = 0; 1264 break; 1265 1266 case SIOCGPPPCSTATS: 1267 memset(&cstats, 0, sizeof(cstats)); 1268 if (ppp->xc_state) 1269 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c); 1270 if (ppp->rc_state) 1271 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d); 1272 if (copy_to_user(addr, &cstats, sizeof(cstats))) 1273 break; 1274 err = 0; 1275 break; 1276 1277 case SIOCGPPPVER: 1278 vers = PPP_VERSION; 1279 if (copy_to_user(addr, vers, strlen(vers) + 1)) 1280 break; 1281 err = 0; 1282 break; 1283 1284 default: 1285 err = -EINVAL; 1286 } 1287 1288 return err; 1289 } 1290 1291 static struct rtnl_link_stats64* 1292 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64) 1293 { 1294 struct ppp *ppp = netdev_priv(dev); 1295 1296 ppp_recv_lock(ppp); 1297 stats64->rx_packets = ppp->stats64.rx_packets; 1298 stats64->rx_bytes = ppp->stats64.rx_bytes; 1299 ppp_recv_unlock(ppp); 1300 1301 ppp_xmit_lock(ppp); 1302 stats64->tx_packets = ppp->stats64.tx_packets; 1303 stats64->tx_bytes = ppp->stats64.tx_bytes; 1304 ppp_xmit_unlock(ppp); 1305 1306 stats64->rx_errors = dev->stats.rx_errors; 1307 stats64->tx_errors = dev->stats.tx_errors; 1308 stats64->rx_dropped = dev->stats.rx_dropped; 1309 stats64->tx_dropped = dev->stats.tx_dropped; 1310 stats64->rx_length_errors = dev->stats.rx_length_errors; 1311 1312 return stats64; 1313 } 1314 1315 static struct lock_class_key ppp_tx_busylock; 1316 static int ppp_dev_init(struct net_device *dev) 1317 { 1318 dev->qdisc_tx_busylock = &ppp_tx_busylock; 1319 return 0; 1320 } 1321 1322 static void ppp_dev_uninit(struct net_device *dev) 1323 { 1324 struct ppp *ppp = netdev_priv(dev); 1325 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 1326 1327 ppp_lock(ppp); 1328 ppp->closing = 1; 1329 ppp_unlock(ppp); 1330 1331 mutex_lock(&pn->all_ppp_mutex); 1332 unit_put(&pn->units_idr, ppp->file.index); 1333 mutex_unlock(&pn->all_ppp_mutex); 1334 1335 ppp->owner = NULL; 1336 1337 ppp->file.dead = 1; 1338 wake_up_interruptible(&ppp->file.rwait); 1339 } 1340 1341 static const struct net_device_ops ppp_netdev_ops = { 1342 .ndo_init = ppp_dev_init, 1343 .ndo_uninit = ppp_dev_uninit, 1344 .ndo_start_xmit = ppp_start_xmit, 1345 .ndo_do_ioctl = ppp_net_ioctl, 1346 .ndo_get_stats64 = ppp_get_stats64, 1347 }; 1348 1349 static struct device_type ppp_type = { 1350 .name = "ppp", 1351 }; 1352 1353 static void ppp_setup(struct net_device *dev) 1354 { 1355 dev->netdev_ops = &ppp_netdev_ops; 1356 SET_NETDEV_DEVTYPE(dev, &ppp_type); 1357 1358 dev->hard_header_len = PPP_HDRLEN; 1359 dev->mtu = PPP_MRU; 1360 dev->addr_len = 0; 1361 dev->tx_queue_len = 3; 1362 dev->type = ARPHRD_PPP; 1363 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 1364 netif_keep_dst(dev); 1365 } 1366 1367 /* 1368 * Transmit-side routines. 1369 */ 1370 1371 /* 1372 * Called to do any work queued up on the transmit side 1373 * that can now be done. 1374 */ 1375 static void 1376 ppp_xmit_process(struct ppp *ppp) 1377 { 1378 struct sk_buff *skb; 1379 1380 ppp_xmit_lock(ppp); 1381 if (!ppp->closing) { 1382 ppp_push(ppp); 1383 while (!ppp->xmit_pending && 1384 (skb = skb_dequeue(&ppp->file.xq))) 1385 ppp_send_frame(ppp, skb); 1386 /* If there's no work left to do, tell the core net 1387 code that we can accept some more. */ 1388 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq)) 1389 netif_wake_queue(ppp->dev); 1390 else 1391 netif_stop_queue(ppp->dev); 1392 } 1393 ppp_xmit_unlock(ppp); 1394 } 1395 1396 static inline struct sk_buff * 1397 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) 1398 { 1399 struct sk_buff *new_skb; 1400 int len; 1401 int new_skb_size = ppp->dev->mtu + 1402 ppp->xcomp->comp_extra + ppp->dev->hard_header_len; 1403 int compressor_skb_size = ppp->dev->mtu + 1404 ppp->xcomp->comp_extra + PPP_HDRLEN; 1405 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC); 1406 if (!new_skb) { 1407 if (net_ratelimit()) 1408 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n"); 1409 return NULL; 1410 } 1411 if (ppp->dev->hard_header_len > PPP_HDRLEN) 1412 skb_reserve(new_skb, 1413 ppp->dev->hard_header_len - PPP_HDRLEN); 1414 1415 /* compressor still expects A/C bytes in hdr */ 1416 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, 1417 new_skb->data, skb->len + 2, 1418 compressor_skb_size); 1419 if (len > 0 && (ppp->flags & SC_CCP_UP)) { 1420 consume_skb(skb); 1421 skb = new_skb; 1422 skb_put(skb, len); 1423 skb_pull(skb, 2); /* pull off A/C bytes */ 1424 } else if (len == 0) { 1425 /* didn't compress, or CCP not up yet */ 1426 consume_skb(new_skb); 1427 new_skb = skb; 1428 } else { 1429 /* 1430 * (len < 0) 1431 * MPPE requires that we do not send unencrypted 1432 * frames. The compressor will return -1 if we 1433 * should drop the frame. We cannot simply test 1434 * the compress_proto because MPPE and MPPC share 1435 * the same number. 1436 */ 1437 if (net_ratelimit()) 1438 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n"); 1439 kfree_skb(skb); 1440 consume_skb(new_skb); 1441 new_skb = NULL; 1442 } 1443 return new_skb; 1444 } 1445 1446 /* 1447 * Compress and send a frame. 1448 * The caller should have locked the xmit path, 1449 * and xmit_pending should be 0. 1450 */ 1451 static void 1452 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) 1453 { 1454 int proto = PPP_PROTO(skb); 1455 struct sk_buff *new_skb; 1456 int len; 1457 unsigned char *cp; 1458 1459 if (proto < 0x8000) { 1460 #ifdef CONFIG_PPP_FILTER 1461 /* check if we should pass this packet */ 1462 /* the filter instructions are constructed assuming 1463 a four-byte PPP header on each packet */ 1464 *skb_push(skb, 2) = 1; 1465 if (ppp->pass_filter && 1466 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 1467 if (ppp->debug & 1) 1468 netdev_printk(KERN_DEBUG, ppp->dev, 1469 "PPP: outbound frame " 1470 "not passed\n"); 1471 kfree_skb(skb); 1472 return; 1473 } 1474 /* if this packet passes the active filter, record the time */ 1475 if (!(ppp->active_filter && 1476 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 1477 ppp->last_xmit = jiffies; 1478 skb_pull(skb, 2); 1479 #else 1480 /* for data packets, record the time */ 1481 ppp->last_xmit = jiffies; 1482 #endif /* CONFIG_PPP_FILTER */ 1483 } 1484 1485 ++ppp->stats64.tx_packets; 1486 ppp->stats64.tx_bytes += skb->len - 2; 1487 1488 switch (proto) { 1489 case PPP_IP: 1490 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0) 1491 break; 1492 /* try to do VJ TCP header compression */ 1493 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2, 1494 GFP_ATOMIC); 1495 if (!new_skb) { 1496 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n"); 1497 goto drop; 1498 } 1499 skb_reserve(new_skb, ppp->dev->hard_header_len - 2); 1500 cp = skb->data + 2; 1501 len = slhc_compress(ppp->vj, cp, skb->len - 2, 1502 new_skb->data + 2, &cp, 1503 !(ppp->flags & SC_NO_TCP_CCID)); 1504 if (cp == skb->data + 2) { 1505 /* didn't compress */ 1506 consume_skb(new_skb); 1507 } else { 1508 if (cp[0] & SL_TYPE_COMPRESSED_TCP) { 1509 proto = PPP_VJC_COMP; 1510 cp[0] &= ~SL_TYPE_COMPRESSED_TCP; 1511 } else { 1512 proto = PPP_VJC_UNCOMP; 1513 cp[0] = skb->data[2]; 1514 } 1515 consume_skb(skb); 1516 skb = new_skb; 1517 cp = skb_put(skb, len + 2); 1518 cp[0] = 0; 1519 cp[1] = proto; 1520 } 1521 break; 1522 1523 case PPP_CCP: 1524 /* peek at outbound CCP frames */ 1525 ppp_ccp_peek(ppp, skb, 0); 1526 break; 1527 } 1528 1529 /* try to do packet compression */ 1530 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state && 1531 proto != PPP_LCP && proto != PPP_CCP) { 1532 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) { 1533 if (net_ratelimit()) 1534 netdev_err(ppp->dev, 1535 "ppp: compression required but " 1536 "down - pkt dropped.\n"); 1537 goto drop; 1538 } 1539 skb = pad_compress_skb(ppp, skb); 1540 if (!skb) 1541 goto drop; 1542 } 1543 1544 /* 1545 * If we are waiting for traffic (demand dialling), 1546 * queue it up for pppd to receive. 1547 */ 1548 if (ppp->flags & SC_LOOP_TRAFFIC) { 1549 if (ppp->file.rq.qlen > PPP_MAX_RQLEN) 1550 goto drop; 1551 skb_queue_tail(&ppp->file.rq, skb); 1552 wake_up_interruptible(&ppp->file.rwait); 1553 return; 1554 } 1555 1556 ppp->xmit_pending = skb; 1557 ppp_push(ppp); 1558 return; 1559 1560 drop: 1561 kfree_skb(skb); 1562 ++ppp->dev->stats.tx_errors; 1563 } 1564 1565 /* 1566 * Try to send the frame in xmit_pending. 1567 * The caller should have the xmit path locked. 1568 */ 1569 static void 1570 ppp_push(struct ppp *ppp) 1571 { 1572 struct list_head *list; 1573 struct channel *pch; 1574 struct sk_buff *skb = ppp->xmit_pending; 1575 1576 if (!skb) 1577 return; 1578 1579 list = &ppp->channels; 1580 if (list_empty(list)) { 1581 /* nowhere to send the packet, just drop it */ 1582 ppp->xmit_pending = NULL; 1583 kfree_skb(skb); 1584 return; 1585 } 1586 1587 if ((ppp->flags & SC_MULTILINK) == 0) { 1588 /* not doing multilink: send it down the first channel */ 1589 list = list->next; 1590 pch = list_entry(list, struct channel, clist); 1591 1592 spin_lock_bh(&pch->downl); 1593 if (pch->chan) { 1594 if (pch->chan->ops->start_xmit(pch->chan, skb)) 1595 ppp->xmit_pending = NULL; 1596 } else { 1597 /* channel got unregistered */ 1598 kfree_skb(skb); 1599 ppp->xmit_pending = NULL; 1600 } 1601 spin_unlock_bh(&pch->downl); 1602 return; 1603 } 1604 1605 #ifdef CONFIG_PPP_MULTILINK 1606 /* Multilink: fragment the packet over as many links 1607 as can take the packet at the moment. */ 1608 if (!ppp_mp_explode(ppp, skb)) 1609 return; 1610 #endif /* CONFIG_PPP_MULTILINK */ 1611 1612 ppp->xmit_pending = NULL; 1613 kfree_skb(skb); 1614 } 1615 1616 #ifdef CONFIG_PPP_MULTILINK 1617 static bool mp_protocol_compress __read_mostly = true; 1618 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR); 1619 MODULE_PARM_DESC(mp_protocol_compress, 1620 "compress protocol id in multilink fragments"); 1621 1622 /* 1623 * Divide a packet to be transmitted into fragments and 1624 * send them out the individual links. 1625 */ 1626 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb) 1627 { 1628 int len, totlen; 1629 int i, bits, hdrlen, mtu; 1630 int flen; 1631 int navail, nfree, nzero; 1632 int nbigger; 1633 int totspeed; 1634 int totfree; 1635 unsigned char *p, *q; 1636 struct list_head *list; 1637 struct channel *pch; 1638 struct sk_buff *frag; 1639 struct ppp_channel *chan; 1640 1641 totspeed = 0; /*total bitrate of the bundle*/ 1642 nfree = 0; /* # channels which have no packet already queued */ 1643 navail = 0; /* total # of usable channels (not deregistered) */ 1644 nzero = 0; /* number of channels with zero speed associated*/ 1645 totfree = 0; /*total # of channels available and 1646 *having no queued packets before 1647 *starting the fragmentation*/ 1648 1649 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1650 i = 0; 1651 list_for_each_entry(pch, &ppp->channels, clist) { 1652 if (pch->chan) { 1653 pch->avail = 1; 1654 navail++; 1655 pch->speed = pch->chan->speed; 1656 } else { 1657 pch->avail = 0; 1658 } 1659 if (pch->avail) { 1660 if (skb_queue_empty(&pch->file.xq) || 1661 !pch->had_frag) { 1662 if (pch->speed == 0) 1663 nzero++; 1664 else 1665 totspeed += pch->speed; 1666 1667 pch->avail = 2; 1668 ++nfree; 1669 ++totfree; 1670 } 1671 if (!pch->had_frag && i < ppp->nxchan) 1672 ppp->nxchan = i; 1673 } 1674 ++i; 1675 } 1676 /* 1677 * Don't start sending this packet unless at least half of 1678 * the channels are free. This gives much better TCP 1679 * performance if we have a lot of channels. 1680 */ 1681 if (nfree == 0 || nfree < navail / 2) 1682 return 0; /* can't take now, leave it in xmit_pending */ 1683 1684 /* Do protocol field compression */ 1685 p = skb->data; 1686 len = skb->len; 1687 if (*p == 0 && mp_protocol_compress) { 1688 ++p; 1689 --len; 1690 } 1691 1692 totlen = len; 1693 nbigger = len % nfree; 1694 1695 /* skip to the channel after the one we last used 1696 and start at that one */ 1697 list = &ppp->channels; 1698 for (i = 0; i < ppp->nxchan; ++i) { 1699 list = list->next; 1700 if (list == &ppp->channels) { 1701 i = 0; 1702 break; 1703 } 1704 } 1705 1706 /* create a fragment for each channel */ 1707 bits = B; 1708 while (len > 0) { 1709 list = list->next; 1710 if (list == &ppp->channels) { 1711 i = 0; 1712 continue; 1713 } 1714 pch = list_entry(list, struct channel, clist); 1715 ++i; 1716 if (!pch->avail) 1717 continue; 1718 1719 /* 1720 * Skip this channel if it has a fragment pending already and 1721 * we haven't given a fragment to all of the free channels. 1722 */ 1723 if (pch->avail == 1) { 1724 if (nfree > 0) 1725 continue; 1726 } else { 1727 pch->avail = 1; 1728 } 1729 1730 /* check the channel's mtu and whether it is still attached. */ 1731 spin_lock_bh(&pch->downl); 1732 if (pch->chan == NULL) { 1733 /* can't use this channel, it's being deregistered */ 1734 if (pch->speed == 0) 1735 nzero--; 1736 else 1737 totspeed -= pch->speed; 1738 1739 spin_unlock_bh(&pch->downl); 1740 pch->avail = 0; 1741 totlen = len; 1742 totfree--; 1743 nfree--; 1744 if (--navail == 0) 1745 break; 1746 continue; 1747 } 1748 1749 /* 1750 *if the channel speed is not set divide 1751 *the packet evenly among the free channels; 1752 *otherwise divide it according to the speed 1753 *of the channel we are going to transmit on 1754 */ 1755 flen = len; 1756 if (nfree > 0) { 1757 if (pch->speed == 0) { 1758 flen = len/nfree; 1759 if (nbigger > 0) { 1760 flen++; 1761 nbigger--; 1762 } 1763 } else { 1764 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) / 1765 ((totspeed*totfree)/pch->speed)) - hdrlen; 1766 if (nbigger > 0) { 1767 flen += ((totfree - nzero)*pch->speed)/totspeed; 1768 nbigger -= ((totfree - nzero)*pch->speed)/ 1769 totspeed; 1770 } 1771 } 1772 nfree--; 1773 } 1774 1775 /* 1776 *check if we are on the last channel or 1777 *we exceded the length of the data to 1778 *fragment 1779 */ 1780 if ((nfree <= 0) || (flen > len)) 1781 flen = len; 1782 /* 1783 *it is not worth to tx on slow channels: 1784 *in that case from the resulting flen according to the 1785 *above formula will be equal or less than zero. 1786 *Skip the channel in this case 1787 */ 1788 if (flen <= 0) { 1789 pch->avail = 2; 1790 spin_unlock_bh(&pch->downl); 1791 continue; 1792 } 1793 1794 /* 1795 * hdrlen includes the 2-byte PPP protocol field, but the 1796 * MTU counts only the payload excluding the protocol field. 1797 * (RFC1661 Section 2) 1798 */ 1799 mtu = pch->chan->mtu - (hdrlen - 2); 1800 if (mtu < 4) 1801 mtu = 4; 1802 if (flen > mtu) 1803 flen = mtu; 1804 if (flen == len) 1805 bits |= E; 1806 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC); 1807 if (!frag) 1808 goto noskb; 1809 q = skb_put(frag, flen + hdrlen); 1810 1811 /* make the MP header */ 1812 put_unaligned_be16(PPP_MP, q); 1813 if (ppp->flags & SC_MP_XSHORTSEQ) { 1814 q[2] = bits + ((ppp->nxseq >> 8) & 0xf); 1815 q[3] = ppp->nxseq; 1816 } else { 1817 q[2] = bits; 1818 q[3] = ppp->nxseq >> 16; 1819 q[4] = ppp->nxseq >> 8; 1820 q[5] = ppp->nxseq; 1821 } 1822 1823 memcpy(q + hdrlen, p, flen); 1824 1825 /* try to send it down the channel */ 1826 chan = pch->chan; 1827 if (!skb_queue_empty(&pch->file.xq) || 1828 !chan->ops->start_xmit(chan, frag)) 1829 skb_queue_tail(&pch->file.xq, frag); 1830 pch->had_frag = 1; 1831 p += flen; 1832 len -= flen; 1833 ++ppp->nxseq; 1834 bits = 0; 1835 spin_unlock_bh(&pch->downl); 1836 } 1837 ppp->nxchan = i; 1838 1839 return 1; 1840 1841 noskb: 1842 spin_unlock_bh(&pch->downl); 1843 if (ppp->debug & 1) 1844 netdev_err(ppp->dev, "PPP: no memory (fragment)\n"); 1845 ++ppp->dev->stats.tx_errors; 1846 ++ppp->nxseq; 1847 return 1; /* abandon the frame */ 1848 } 1849 #endif /* CONFIG_PPP_MULTILINK */ 1850 1851 /* 1852 * Try to send data out on a channel. 1853 */ 1854 static void 1855 ppp_channel_push(struct channel *pch) 1856 { 1857 struct sk_buff *skb; 1858 struct ppp *ppp; 1859 1860 spin_lock_bh(&pch->downl); 1861 if (pch->chan) { 1862 while (!skb_queue_empty(&pch->file.xq)) { 1863 skb = skb_dequeue(&pch->file.xq); 1864 if (!pch->chan->ops->start_xmit(pch->chan, skb)) { 1865 /* put the packet back and try again later */ 1866 skb_queue_head(&pch->file.xq, skb); 1867 break; 1868 } 1869 } 1870 } else { 1871 /* channel got deregistered */ 1872 skb_queue_purge(&pch->file.xq); 1873 } 1874 spin_unlock_bh(&pch->downl); 1875 /* see if there is anything from the attached unit to be sent */ 1876 if (skb_queue_empty(&pch->file.xq)) { 1877 read_lock_bh(&pch->upl); 1878 ppp = pch->ppp; 1879 if (ppp) 1880 ppp_xmit_process(ppp); 1881 read_unlock_bh(&pch->upl); 1882 } 1883 } 1884 1885 /* 1886 * Receive-side routines. 1887 */ 1888 1889 struct ppp_mp_skb_parm { 1890 u32 sequence; 1891 u8 BEbits; 1892 }; 1893 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb)) 1894 1895 static inline void 1896 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1897 { 1898 ppp_recv_lock(ppp); 1899 if (!ppp->closing) 1900 ppp_receive_frame(ppp, skb, pch); 1901 else 1902 kfree_skb(skb); 1903 ppp_recv_unlock(ppp); 1904 } 1905 1906 void 1907 ppp_input(struct ppp_channel *chan, struct sk_buff *skb) 1908 { 1909 struct channel *pch = chan->ppp; 1910 int proto; 1911 1912 if (!pch) { 1913 kfree_skb(skb); 1914 return; 1915 } 1916 1917 read_lock_bh(&pch->upl); 1918 if (!pskb_may_pull(skb, 2)) { 1919 kfree_skb(skb); 1920 if (pch->ppp) { 1921 ++pch->ppp->dev->stats.rx_length_errors; 1922 ppp_receive_error(pch->ppp); 1923 } 1924 goto done; 1925 } 1926 1927 proto = PPP_PROTO(skb); 1928 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) { 1929 /* put it on the channel queue */ 1930 skb_queue_tail(&pch->file.rq, skb); 1931 /* drop old frames if queue too long */ 1932 while (pch->file.rq.qlen > PPP_MAX_RQLEN && 1933 (skb = skb_dequeue(&pch->file.rq))) 1934 kfree_skb(skb); 1935 wake_up_interruptible(&pch->file.rwait); 1936 } else { 1937 ppp_do_recv(pch->ppp, skb, pch); 1938 } 1939 1940 done: 1941 read_unlock_bh(&pch->upl); 1942 } 1943 1944 /* Put a 0-length skb in the receive queue as an error indication */ 1945 void 1946 ppp_input_error(struct ppp_channel *chan, int code) 1947 { 1948 struct channel *pch = chan->ppp; 1949 struct sk_buff *skb; 1950 1951 if (!pch) 1952 return; 1953 1954 read_lock_bh(&pch->upl); 1955 if (pch->ppp) { 1956 skb = alloc_skb(0, GFP_ATOMIC); 1957 if (skb) { 1958 skb->len = 0; /* probably unnecessary */ 1959 skb->cb[0] = code; 1960 ppp_do_recv(pch->ppp, skb, pch); 1961 } 1962 } 1963 read_unlock_bh(&pch->upl); 1964 } 1965 1966 /* 1967 * We come in here to process a received frame. 1968 * The receive side of the ppp unit is locked. 1969 */ 1970 static void 1971 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1972 { 1973 /* note: a 0-length skb is used as an error indication */ 1974 if (skb->len > 0) { 1975 skb_checksum_complete_unset(skb); 1976 #ifdef CONFIG_PPP_MULTILINK 1977 /* XXX do channel-level decompression here */ 1978 if (PPP_PROTO(skb) == PPP_MP) 1979 ppp_receive_mp_frame(ppp, skb, pch); 1980 else 1981 #endif /* CONFIG_PPP_MULTILINK */ 1982 ppp_receive_nonmp_frame(ppp, skb); 1983 } else { 1984 kfree_skb(skb); 1985 ppp_receive_error(ppp); 1986 } 1987 } 1988 1989 static void 1990 ppp_receive_error(struct ppp *ppp) 1991 { 1992 ++ppp->dev->stats.rx_errors; 1993 if (ppp->vj) 1994 slhc_toss(ppp->vj); 1995 } 1996 1997 static void 1998 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) 1999 { 2000 struct sk_buff *ns; 2001 int proto, len, npi; 2002 2003 /* 2004 * Decompress the frame, if compressed. 2005 * Note that some decompressors need to see uncompressed frames 2006 * that come in as well as compressed frames. 2007 */ 2008 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) && 2009 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0) 2010 skb = ppp_decompress_frame(ppp, skb); 2011 2012 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR) 2013 goto err; 2014 2015 proto = PPP_PROTO(skb); 2016 switch (proto) { 2017 case PPP_VJC_COMP: 2018 /* decompress VJ compressed packets */ 2019 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 2020 goto err; 2021 2022 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) { 2023 /* copy to a new sk_buff with more tailroom */ 2024 ns = dev_alloc_skb(skb->len + 128); 2025 if (!ns) { 2026 netdev_err(ppp->dev, "PPP: no memory " 2027 "(VJ decomp)\n"); 2028 goto err; 2029 } 2030 skb_reserve(ns, 2); 2031 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len); 2032 consume_skb(skb); 2033 skb = ns; 2034 } 2035 else 2036 skb->ip_summed = CHECKSUM_NONE; 2037 2038 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2); 2039 if (len <= 0) { 2040 netdev_printk(KERN_DEBUG, ppp->dev, 2041 "PPP: VJ decompression error\n"); 2042 goto err; 2043 } 2044 len += 2; 2045 if (len > skb->len) 2046 skb_put(skb, len - skb->len); 2047 else if (len < skb->len) 2048 skb_trim(skb, len); 2049 proto = PPP_IP; 2050 break; 2051 2052 case PPP_VJC_UNCOMP: 2053 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 2054 goto err; 2055 2056 /* Until we fix the decompressor need to make sure 2057 * data portion is linear. 2058 */ 2059 if (!pskb_may_pull(skb, skb->len)) 2060 goto err; 2061 2062 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) { 2063 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n"); 2064 goto err; 2065 } 2066 proto = PPP_IP; 2067 break; 2068 2069 case PPP_CCP: 2070 ppp_ccp_peek(ppp, skb, 1); 2071 break; 2072 } 2073 2074 ++ppp->stats64.rx_packets; 2075 ppp->stats64.rx_bytes += skb->len - 2; 2076 2077 npi = proto_to_npindex(proto); 2078 if (npi < 0) { 2079 /* control or unknown frame - pass it to pppd */ 2080 skb_queue_tail(&ppp->file.rq, skb); 2081 /* limit queue length by dropping old frames */ 2082 while (ppp->file.rq.qlen > PPP_MAX_RQLEN && 2083 (skb = skb_dequeue(&ppp->file.rq))) 2084 kfree_skb(skb); 2085 /* wake up any process polling or blocking on read */ 2086 wake_up_interruptible(&ppp->file.rwait); 2087 2088 } else { 2089 /* network protocol frame - give it to the kernel */ 2090 2091 #ifdef CONFIG_PPP_FILTER 2092 /* check if the packet passes the pass and active filters */ 2093 /* the filter instructions are constructed assuming 2094 a four-byte PPP header on each packet */ 2095 if (ppp->pass_filter || ppp->active_filter) { 2096 if (skb_unclone(skb, GFP_ATOMIC)) 2097 goto err; 2098 2099 *skb_push(skb, 2) = 0; 2100 if (ppp->pass_filter && 2101 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 2102 if (ppp->debug & 1) 2103 netdev_printk(KERN_DEBUG, ppp->dev, 2104 "PPP: inbound frame " 2105 "not passed\n"); 2106 kfree_skb(skb); 2107 return; 2108 } 2109 if (!(ppp->active_filter && 2110 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 2111 ppp->last_recv = jiffies; 2112 __skb_pull(skb, 2); 2113 } else 2114 #endif /* CONFIG_PPP_FILTER */ 2115 ppp->last_recv = jiffies; 2116 2117 if ((ppp->dev->flags & IFF_UP) == 0 || 2118 ppp->npmode[npi] != NPMODE_PASS) { 2119 kfree_skb(skb); 2120 } else { 2121 /* chop off protocol */ 2122 skb_pull_rcsum(skb, 2); 2123 skb->dev = ppp->dev; 2124 skb->protocol = htons(npindex_to_ethertype[npi]); 2125 skb_reset_mac_header(skb); 2126 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, 2127 dev_net(ppp->dev))); 2128 netif_rx(skb); 2129 } 2130 } 2131 return; 2132 2133 err: 2134 kfree_skb(skb); 2135 ppp_receive_error(ppp); 2136 } 2137 2138 static struct sk_buff * 2139 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb) 2140 { 2141 int proto = PPP_PROTO(skb); 2142 struct sk_buff *ns; 2143 int len; 2144 2145 /* Until we fix all the decompressor's need to make sure 2146 * data portion is linear. 2147 */ 2148 if (!pskb_may_pull(skb, skb->len)) 2149 goto err; 2150 2151 if (proto == PPP_COMP) { 2152 int obuff_size; 2153 2154 switch(ppp->rcomp->compress_proto) { 2155 case CI_MPPE: 2156 obuff_size = ppp->mru + PPP_HDRLEN + 1; 2157 break; 2158 default: 2159 obuff_size = ppp->mru + PPP_HDRLEN; 2160 break; 2161 } 2162 2163 ns = dev_alloc_skb(obuff_size); 2164 if (!ns) { 2165 netdev_err(ppp->dev, "ppp_decompress_frame: " 2166 "no memory\n"); 2167 goto err; 2168 } 2169 /* the decompressor still expects the A/C bytes in the hdr */ 2170 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2, 2171 skb->len + 2, ns->data, obuff_size); 2172 if (len < 0) { 2173 /* Pass the compressed frame to pppd as an 2174 error indication. */ 2175 if (len == DECOMP_FATALERROR) 2176 ppp->rstate |= SC_DC_FERROR; 2177 kfree_skb(ns); 2178 goto err; 2179 } 2180 2181 consume_skb(skb); 2182 skb = ns; 2183 skb_put(skb, len); 2184 skb_pull(skb, 2); /* pull off the A/C bytes */ 2185 2186 } else { 2187 /* Uncompressed frame - pass to decompressor so it 2188 can update its dictionary if necessary. */ 2189 if (ppp->rcomp->incomp) 2190 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2, 2191 skb->len + 2); 2192 } 2193 2194 return skb; 2195 2196 err: 2197 ppp->rstate |= SC_DC_ERROR; 2198 ppp_receive_error(ppp); 2199 return skb; 2200 } 2201 2202 #ifdef CONFIG_PPP_MULTILINK 2203 /* 2204 * Receive a multilink frame. 2205 * We put it on the reconstruction queue and then pull off 2206 * as many completed frames as we can. 2207 */ 2208 static void 2209 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2210 { 2211 u32 mask, seq; 2212 struct channel *ch; 2213 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 2214 2215 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0) 2216 goto err; /* no good, throw it away */ 2217 2218 /* Decode sequence number and begin/end bits */ 2219 if (ppp->flags & SC_MP_SHORTSEQ) { 2220 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3]; 2221 mask = 0xfff; 2222 } else { 2223 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5]; 2224 mask = 0xffffff; 2225 } 2226 PPP_MP_CB(skb)->BEbits = skb->data[2]; 2227 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */ 2228 2229 /* 2230 * Do protocol ID decompression on the first fragment of each packet. 2231 */ 2232 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1)) 2233 *skb_push(skb, 1) = 0; 2234 2235 /* 2236 * Expand sequence number to 32 bits, making it as close 2237 * as possible to ppp->minseq. 2238 */ 2239 seq |= ppp->minseq & ~mask; 2240 if ((int)(ppp->minseq - seq) > (int)(mask >> 1)) 2241 seq += mask + 1; 2242 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1)) 2243 seq -= mask + 1; /* should never happen */ 2244 PPP_MP_CB(skb)->sequence = seq; 2245 pch->lastseq = seq; 2246 2247 /* 2248 * If this packet comes before the next one we were expecting, 2249 * drop it. 2250 */ 2251 if (seq_before(seq, ppp->nextseq)) { 2252 kfree_skb(skb); 2253 ++ppp->dev->stats.rx_dropped; 2254 ppp_receive_error(ppp); 2255 return; 2256 } 2257 2258 /* 2259 * Reevaluate minseq, the minimum over all channels of the 2260 * last sequence number received on each channel. Because of 2261 * the increasing sequence number rule, we know that any fragment 2262 * before `minseq' which hasn't arrived is never going to arrive. 2263 * The list of channels can't change because we have the receive 2264 * side of the ppp unit locked. 2265 */ 2266 list_for_each_entry(ch, &ppp->channels, clist) { 2267 if (seq_before(ch->lastseq, seq)) 2268 seq = ch->lastseq; 2269 } 2270 if (seq_before(ppp->minseq, seq)) 2271 ppp->minseq = seq; 2272 2273 /* Put the fragment on the reconstruction queue */ 2274 ppp_mp_insert(ppp, skb); 2275 2276 /* If the queue is getting long, don't wait any longer for packets 2277 before the start of the queue. */ 2278 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) { 2279 struct sk_buff *mskb = skb_peek(&ppp->mrq); 2280 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence)) 2281 ppp->minseq = PPP_MP_CB(mskb)->sequence; 2282 } 2283 2284 /* Pull completed packets off the queue and receive them. */ 2285 while ((skb = ppp_mp_reconstruct(ppp))) { 2286 if (pskb_may_pull(skb, 2)) 2287 ppp_receive_nonmp_frame(ppp, skb); 2288 else { 2289 ++ppp->dev->stats.rx_length_errors; 2290 kfree_skb(skb); 2291 ppp_receive_error(ppp); 2292 } 2293 } 2294 2295 return; 2296 2297 err: 2298 kfree_skb(skb); 2299 ppp_receive_error(ppp); 2300 } 2301 2302 /* 2303 * Insert a fragment on the MP reconstruction queue. 2304 * The queue is ordered by increasing sequence number. 2305 */ 2306 static void 2307 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb) 2308 { 2309 struct sk_buff *p; 2310 struct sk_buff_head *list = &ppp->mrq; 2311 u32 seq = PPP_MP_CB(skb)->sequence; 2312 2313 /* N.B. we don't need to lock the list lock because we have the 2314 ppp unit receive-side lock. */ 2315 skb_queue_walk(list, p) { 2316 if (seq_before(seq, PPP_MP_CB(p)->sequence)) 2317 break; 2318 } 2319 __skb_queue_before(list, p, skb); 2320 } 2321 2322 /* 2323 * Reconstruct a packet from the MP fragment queue. 2324 * We go through increasing sequence numbers until we find a 2325 * complete packet, or we get to the sequence number for a fragment 2326 * which hasn't arrived but might still do so. 2327 */ 2328 static struct sk_buff * 2329 ppp_mp_reconstruct(struct ppp *ppp) 2330 { 2331 u32 seq = ppp->nextseq; 2332 u32 minseq = ppp->minseq; 2333 struct sk_buff_head *list = &ppp->mrq; 2334 struct sk_buff *p, *tmp; 2335 struct sk_buff *head, *tail; 2336 struct sk_buff *skb = NULL; 2337 int lost = 0, len = 0; 2338 2339 if (ppp->mrru == 0) /* do nothing until mrru is set */ 2340 return NULL; 2341 head = list->next; 2342 tail = NULL; 2343 skb_queue_walk_safe(list, p, tmp) { 2344 again: 2345 if (seq_before(PPP_MP_CB(p)->sequence, seq)) { 2346 /* this can't happen, anyway ignore the skb */ 2347 netdev_err(ppp->dev, "ppp_mp_reconstruct bad " 2348 "seq %u < %u\n", 2349 PPP_MP_CB(p)->sequence, seq); 2350 __skb_unlink(p, list); 2351 kfree_skb(p); 2352 continue; 2353 } 2354 if (PPP_MP_CB(p)->sequence != seq) { 2355 u32 oldseq; 2356 /* Fragment `seq' is missing. If it is after 2357 minseq, it might arrive later, so stop here. */ 2358 if (seq_after(seq, minseq)) 2359 break; 2360 /* Fragment `seq' is lost, keep going. */ 2361 lost = 1; 2362 oldseq = seq; 2363 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)? 2364 minseq + 1: PPP_MP_CB(p)->sequence; 2365 2366 if (ppp->debug & 1) 2367 netdev_printk(KERN_DEBUG, ppp->dev, 2368 "lost frag %u..%u\n", 2369 oldseq, seq-1); 2370 2371 goto again; 2372 } 2373 2374 /* 2375 * At this point we know that all the fragments from 2376 * ppp->nextseq to seq are either present or lost. 2377 * Also, there are no complete packets in the queue 2378 * that have no missing fragments and end before this 2379 * fragment. 2380 */ 2381 2382 /* B bit set indicates this fragment starts a packet */ 2383 if (PPP_MP_CB(p)->BEbits & B) { 2384 head = p; 2385 lost = 0; 2386 len = 0; 2387 } 2388 2389 len += p->len; 2390 2391 /* Got a complete packet yet? */ 2392 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) && 2393 (PPP_MP_CB(head)->BEbits & B)) { 2394 if (len > ppp->mrru + 2) { 2395 ++ppp->dev->stats.rx_length_errors; 2396 netdev_printk(KERN_DEBUG, ppp->dev, 2397 "PPP: reconstructed packet" 2398 " is too long (%d)\n", len); 2399 } else { 2400 tail = p; 2401 break; 2402 } 2403 ppp->nextseq = seq + 1; 2404 } 2405 2406 /* 2407 * If this is the ending fragment of a packet, 2408 * and we haven't found a complete valid packet yet, 2409 * we can discard up to and including this fragment. 2410 */ 2411 if (PPP_MP_CB(p)->BEbits & E) { 2412 struct sk_buff *tmp2; 2413 2414 skb_queue_reverse_walk_from_safe(list, p, tmp2) { 2415 if (ppp->debug & 1) 2416 netdev_printk(KERN_DEBUG, ppp->dev, 2417 "discarding frag %u\n", 2418 PPP_MP_CB(p)->sequence); 2419 __skb_unlink(p, list); 2420 kfree_skb(p); 2421 } 2422 head = skb_peek(list); 2423 if (!head) 2424 break; 2425 } 2426 ++seq; 2427 } 2428 2429 /* If we have a complete packet, copy it all into one skb. */ 2430 if (tail != NULL) { 2431 /* If we have discarded any fragments, 2432 signal a receive error. */ 2433 if (PPP_MP_CB(head)->sequence != ppp->nextseq) { 2434 skb_queue_walk_safe(list, p, tmp) { 2435 if (p == head) 2436 break; 2437 if (ppp->debug & 1) 2438 netdev_printk(KERN_DEBUG, ppp->dev, 2439 "discarding frag %u\n", 2440 PPP_MP_CB(p)->sequence); 2441 __skb_unlink(p, list); 2442 kfree_skb(p); 2443 } 2444 2445 if (ppp->debug & 1) 2446 netdev_printk(KERN_DEBUG, ppp->dev, 2447 " missed pkts %u..%u\n", 2448 ppp->nextseq, 2449 PPP_MP_CB(head)->sequence-1); 2450 ++ppp->dev->stats.rx_dropped; 2451 ppp_receive_error(ppp); 2452 } 2453 2454 skb = head; 2455 if (head != tail) { 2456 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list; 2457 p = skb_queue_next(list, head); 2458 __skb_unlink(skb, list); 2459 skb_queue_walk_from_safe(list, p, tmp) { 2460 __skb_unlink(p, list); 2461 *fragpp = p; 2462 p->next = NULL; 2463 fragpp = &p->next; 2464 2465 skb->len += p->len; 2466 skb->data_len += p->len; 2467 skb->truesize += p->truesize; 2468 2469 if (p == tail) 2470 break; 2471 } 2472 } else { 2473 __skb_unlink(skb, list); 2474 } 2475 2476 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1; 2477 } 2478 2479 return skb; 2480 } 2481 #endif /* CONFIG_PPP_MULTILINK */ 2482 2483 /* 2484 * Channel interface. 2485 */ 2486 2487 /* Create a new, unattached ppp channel. */ 2488 int ppp_register_channel(struct ppp_channel *chan) 2489 { 2490 return ppp_register_net_channel(current->nsproxy->net_ns, chan); 2491 } 2492 2493 /* Create a new, unattached ppp channel for specified net. */ 2494 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan) 2495 { 2496 struct channel *pch; 2497 struct ppp_net *pn; 2498 2499 pch = kzalloc(sizeof(struct channel), GFP_KERNEL); 2500 if (!pch) 2501 return -ENOMEM; 2502 2503 pn = ppp_pernet(net); 2504 2505 pch->ppp = NULL; 2506 pch->chan = chan; 2507 pch->chan_net = get_net(net); 2508 chan->ppp = pch; 2509 init_ppp_file(&pch->file, CHANNEL); 2510 pch->file.hdrlen = chan->hdrlen; 2511 #ifdef CONFIG_PPP_MULTILINK 2512 pch->lastseq = -1; 2513 #endif /* CONFIG_PPP_MULTILINK */ 2514 init_rwsem(&pch->chan_sem); 2515 spin_lock_init(&pch->downl); 2516 rwlock_init(&pch->upl); 2517 2518 spin_lock_bh(&pn->all_channels_lock); 2519 pch->file.index = ++pn->last_channel_index; 2520 list_add(&pch->list, &pn->new_channels); 2521 atomic_inc(&channel_count); 2522 spin_unlock_bh(&pn->all_channels_lock); 2523 2524 return 0; 2525 } 2526 2527 /* 2528 * Return the index of a channel. 2529 */ 2530 int ppp_channel_index(struct ppp_channel *chan) 2531 { 2532 struct channel *pch = chan->ppp; 2533 2534 if (pch) 2535 return pch->file.index; 2536 return -1; 2537 } 2538 2539 /* 2540 * Return the PPP unit number to which a channel is connected. 2541 */ 2542 int ppp_unit_number(struct ppp_channel *chan) 2543 { 2544 struct channel *pch = chan->ppp; 2545 int unit = -1; 2546 2547 if (pch) { 2548 read_lock_bh(&pch->upl); 2549 if (pch->ppp) 2550 unit = pch->ppp->file.index; 2551 read_unlock_bh(&pch->upl); 2552 } 2553 return unit; 2554 } 2555 2556 /* 2557 * Return the PPP device interface name of a channel. 2558 */ 2559 char *ppp_dev_name(struct ppp_channel *chan) 2560 { 2561 struct channel *pch = chan->ppp; 2562 char *name = NULL; 2563 2564 if (pch) { 2565 read_lock_bh(&pch->upl); 2566 if (pch->ppp && pch->ppp->dev) 2567 name = pch->ppp->dev->name; 2568 read_unlock_bh(&pch->upl); 2569 } 2570 return name; 2571 } 2572 2573 2574 /* 2575 * Disconnect a channel from the generic layer. 2576 * This must be called in process context. 2577 */ 2578 void 2579 ppp_unregister_channel(struct ppp_channel *chan) 2580 { 2581 struct channel *pch = chan->ppp; 2582 struct ppp_net *pn; 2583 2584 if (!pch) 2585 return; /* should never happen */ 2586 2587 chan->ppp = NULL; 2588 2589 /* 2590 * This ensures that we have returned from any calls into the 2591 * the channel's start_xmit or ioctl routine before we proceed. 2592 */ 2593 down_write(&pch->chan_sem); 2594 spin_lock_bh(&pch->downl); 2595 pch->chan = NULL; 2596 spin_unlock_bh(&pch->downl); 2597 up_write(&pch->chan_sem); 2598 ppp_disconnect_channel(pch); 2599 2600 pn = ppp_pernet(pch->chan_net); 2601 spin_lock_bh(&pn->all_channels_lock); 2602 list_del(&pch->list); 2603 spin_unlock_bh(&pn->all_channels_lock); 2604 put_net(pch->chan_net); 2605 pch->chan_net = NULL; 2606 2607 pch->file.dead = 1; 2608 wake_up_interruptible(&pch->file.rwait); 2609 if (atomic_dec_and_test(&pch->file.refcnt)) 2610 ppp_destroy_channel(pch); 2611 } 2612 2613 /* 2614 * Callback from a channel when it can accept more to transmit. 2615 * This should be called at BH/softirq level, not interrupt level. 2616 */ 2617 void 2618 ppp_output_wakeup(struct ppp_channel *chan) 2619 { 2620 struct channel *pch = chan->ppp; 2621 2622 if (!pch) 2623 return; 2624 ppp_channel_push(pch); 2625 } 2626 2627 /* 2628 * Compression control. 2629 */ 2630 2631 /* Process the PPPIOCSCOMPRESS ioctl. */ 2632 static int 2633 ppp_set_compress(struct ppp *ppp, unsigned long arg) 2634 { 2635 int err; 2636 struct compressor *cp, *ocomp; 2637 struct ppp_option_data data; 2638 void *state, *ostate; 2639 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH]; 2640 2641 err = -EFAULT; 2642 if (copy_from_user(&data, (void __user *) arg, sizeof(data))) 2643 goto out; 2644 if (data.length > CCP_MAX_OPTION_LENGTH) 2645 goto out; 2646 if (copy_from_user(ccp_option, (void __user *) data.ptr, data.length)) 2647 goto out; 2648 2649 err = -EINVAL; 2650 if (data.length < 2 || ccp_option[1] < 2 || ccp_option[1] > data.length) 2651 goto out; 2652 2653 cp = try_then_request_module( 2654 find_compressor(ccp_option[0]), 2655 "ppp-compress-%d", ccp_option[0]); 2656 if (!cp) 2657 goto out; 2658 2659 err = -ENOBUFS; 2660 if (data.transmit) { 2661 state = cp->comp_alloc(ccp_option, data.length); 2662 if (state) { 2663 ppp_xmit_lock(ppp); 2664 ppp->xstate &= ~SC_COMP_RUN; 2665 ocomp = ppp->xcomp; 2666 ostate = ppp->xc_state; 2667 ppp->xcomp = cp; 2668 ppp->xc_state = state; 2669 ppp_xmit_unlock(ppp); 2670 if (ostate) { 2671 ocomp->comp_free(ostate); 2672 module_put(ocomp->owner); 2673 } 2674 err = 0; 2675 } else 2676 module_put(cp->owner); 2677 2678 } else { 2679 state = cp->decomp_alloc(ccp_option, data.length); 2680 if (state) { 2681 ppp_recv_lock(ppp); 2682 ppp->rstate &= ~SC_DECOMP_RUN; 2683 ocomp = ppp->rcomp; 2684 ostate = ppp->rc_state; 2685 ppp->rcomp = cp; 2686 ppp->rc_state = state; 2687 ppp_recv_unlock(ppp); 2688 if (ostate) { 2689 ocomp->decomp_free(ostate); 2690 module_put(ocomp->owner); 2691 } 2692 err = 0; 2693 } else 2694 module_put(cp->owner); 2695 } 2696 2697 out: 2698 return err; 2699 } 2700 2701 /* 2702 * Look at a CCP packet and update our state accordingly. 2703 * We assume the caller has the xmit or recv path locked. 2704 */ 2705 static void 2706 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound) 2707 { 2708 unsigned char *dp; 2709 int len; 2710 2711 if (!pskb_may_pull(skb, CCP_HDRLEN + 2)) 2712 return; /* no header */ 2713 dp = skb->data + 2; 2714 2715 switch (CCP_CODE(dp)) { 2716 case CCP_CONFREQ: 2717 2718 /* A ConfReq starts negotiation of compression 2719 * in one direction of transmission, 2720 * and hence brings it down...but which way? 2721 * 2722 * Remember: 2723 * A ConfReq indicates what the sender would like to receive 2724 */ 2725 if(inbound) 2726 /* He is proposing what I should send */ 2727 ppp->xstate &= ~SC_COMP_RUN; 2728 else 2729 /* I am proposing to what he should send */ 2730 ppp->rstate &= ~SC_DECOMP_RUN; 2731 2732 break; 2733 2734 case CCP_TERMREQ: 2735 case CCP_TERMACK: 2736 /* 2737 * CCP is going down, both directions of transmission 2738 */ 2739 ppp->rstate &= ~SC_DECOMP_RUN; 2740 ppp->xstate &= ~SC_COMP_RUN; 2741 break; 2742 2743 case CCP_CONFACK: 2744 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN) 2745 break; 2746 len = CCP_LENGTH(dp); 2747 if (!pskb_may_pull(skb, len + 2)) 2748 return; /* too short */ 2749 dp += CCP_HDRLEN; 2750 len -= CCP_HDRLEN; 2751 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp)) 2752 break; 2753 if (inbound) { 2754 /* we will start receiving compressed packets */ 2755 if (!ppp->rc_state) 2756 break; 2757 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len, 2758 ppp->file.index, 0, ppp->mru, ppp->debug)) { 2759 ppp->rstate |= SC_DECOMP_RUN; 2760 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR); 2761 } 2762 } else { 2763 /* we will soon start sending compressed packets */ 2764 if (!ppp->xc_state) 2765 break; 2766 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len, 2767 ppp->file.index, 0, ppp->debug)) 2768 ppp->xstate |= SC_COMP_RUN; 2769 } 2770 break; 2771 2772 case CCP_RESETACK: 2773 /* reset the [de]compressor */ 2774 if ((ppp->flags & SC_CCP_UP) == 0) 2775 break; 2776 if (inbound) { 2777 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) { 2778 ppp->rcomp->decomp_reset(ppp->rc_state); 2779 ppp->rstate &= ~SC_DC_ERROR; 2780 } 2781 } else { 2782 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN)) 2783 ppp->xcomp->comp_reset(ppp->xc_state); 2784 } 2785 break; 2786 } 2787 } 2788 2789 /* Free up compression resources. */ 2790 static void 2791 ppp_ccp_closed(struct ppp *ppp) 2792 { 2793 void *xstate, *rstate; 2794 struct compressor *xcomp, *rcomp; 2795 2796 ppp_lock(ppp); 2797 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP); 2798 ppp->xstate = 0; 2799 xcomp = ppp->xcomp; 2800 xstate = ppp->xc_state; 2801 ppp->xc_state = NULL; 2802 ppp->rstate = 0; 2803 rcomp = ppp->rcomp; 2804 rstate = ppp->rc_state; 2805 ppp->rc_state = NULL; 2806 ppp_unlock(ppp); 2807 2808 if (xstate) { 2809 xcomp->comp_free(xstate); 2810 module_put(xcomp->owner); 2811 } 2812 if (rstate) { 2813 rcomp->decomp_free(rstate); 2814 module_put(rcomp->owner); 2815 } 2816 } 2817 2818 /* List of compressors. */ 2819 static LIST_HEAD(compressor_list); 2820 static DEFINE_SPINLOCK(compressor_list_lock); 2821 2822 struct compressor_entry { 2823 struct list_head list; 2824 struct compressor *comp; 2825 }; 2826 2827 static struct compressor_entry * 2828 find_comp_entry(int proto) 2829 { 2830 struct compressor_entry *ce; 2831 2832 list_for_each_entry(ce, &compressor_list, list) { 2833 if (ce->comp->compress_proto == proto) 2834 return ce; 2835 } 2836 return NULL; 2837 } 2838 2839 /* Register a compressor */ 2840 int 2841 ppp_register_compressor(struct compressor *cp) 2842 { 2843 struct compressor_entry *ce; 2844 int ret; 2845 spin_lock(&compressor_list_lock); 2846 ret = -EEXIST; 2847 if (find_comp_entry(cp->compress_proto)) 2848 goto out; 2849 ret = -ENOMEM; 2850 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC); 2851 if (!ce) 2852 goto out; 2853 ret = 0; 2854 ce->comp = cp; 2855 list_add(&ce->list, &compressor_list); 2856 out: 2857 spin_unlock(&compressor_list_lock); 2858 return ret; 2859 } 2860 2861 /* Unregister a compressor */ 2862 void 2863 ppp_unregister_compressor(struct compressor *cp) 2864 { 2865 struct compressor_entry *ce; 2866 2867 spin_lock(&compressor_list_lock); 2868 ce = find_comp_entry(cp->compress_proto); 2869 if (ce && ce->comp == cp) { 2870 list_del(&ce->list); 2871 kfree(ce); 2872 } 2873 spin_unlock(&compressor_list_lock); 2874 } 2875 2876 /* Find a compressor. */ 2877 static struct compressor * 2878 find_compressor(int type) 2879 { 2880 struct compressor_entry *ce; 2881 struct compressor *cp = NULL; 2882 2883 spin_lock(&compressor_list_lock); 2884 ce = find_comp_entry(type); 2885 if (ce) { 2886 cp = ce->comp; 2887 if (!try_module_get(cp->owner)) 2888 cp = NULL; 2889 } 2890 spin_unlock(&compressor_list_lock); 2891 return cp; 2892 } 2893 2894 /* 2895 * Miscelleneous stuff. 2896 */ 2897 2898 static void 2899 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st) 2900 { 2901 struct slcompress *vj = ppp->vj; 2902 2903 memset(st, 0, sizeof(*st)); 2904 st->p.ppp_ipackets = ppp->stats64.rx_packets; 2905 st->p.ppp_ierrors = ppp->dev->stats.rx_errors; 2906 st->p.ppp_ibytes = ppp->stats64.rx_bytes; 2907 st->p.ppp_opackets = ppp->stats64.tx_packets; 2908 st->p.ppp_oerrors = ppp->dev->stats.tx_errors; 2909 st->p.ppp_obytes = ppp->stats64.tx_bytes; 2910 if (!vj) 2911 return; 2912 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed; 2913 st->vj.vjs_compressed = vj->sls_o_compressed; 2914 st->vj.vjs_searches = vj->sls_o_searches; 2915 st->vj.vjs_misses = vj->sls_o_misses; 2916 st->vj.vjs_errorin = vj->sls_i_error; 2917 st->vj.vjs_tossed = vj->sls_i_tossed; 2918 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed; 2919 st->vj.vjs_compressedin = vj->sls_i_compressed; 2920 } 2921 2922 /* 2923 * Stuff for handling the lists of ppp units and channels 2924 * and for initialization. 2925 */ 2926 2927 /* 2928 * Create a new ppp interface unit. Fails if it can't allocate memory 2929 * or if there is already a unit with the requested number. 2930 * unit == -1 means allocate a new number. 2931 */ 2932 static int ppp_create_interface(struct net *net, struct file *file, int *unit) 2933 { 2934 struct ppp_config conf = { 2935 .file = file, 2936 .unit = *unit, 2937 .ifname_is_set = false, 2938 }; 2939 struct net_device *dev; 2940 struct ppp *ppp; 2941 int err; 2942 2943 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup); 2944 if (!dev) { 2945 err = -ENOMEM; 2946 goto err; 2947 } 2948 dev_net_set(dev, net); 2949 dev->rtnl_link_ops = &ppp_link_ops; 2950 2951 rtnl_lock(); 2952 2953 err = ppp_dev_configure(net, dev, &conf); 2954 if (err < 0) 2955 goto err_dev; 2956 ppp = netdev_priv(dev); 2957 *unit = ppp->file.index; 2958 2959 rtnl_unlock(); 2960 2961 return 0; 2962 2963 err_dev: 2964 rtnl_unlock(); 2965 free_netdev(dev); 2966 err: 2967 return err; 2968 } 2969 2970 /* 2971 * Initialize a ppp_file structure. 2972 */ 2973 static void 2974 init_ppp_file(struct ppp_file *pf, int kind) 2975 { 2976 pf->kind = kind; 2977 skb_queue_head_init(&pf->xq); 2978 skb_queue_head_init(&pf->rq); 2979 atomic_set(&pf->refcnt, 1); 2980 init_waitqueue_head(&pf->rwait); 2981 } 2982 2983 /* 2984 * Free the memory used by a ppp unit. This is only called once 2985 * there are no channels connected to the unit and no file structs 2986 * that reference the unit. 2987 */ 2988 static void ppp_destroy_interface(struct ppp *ppp) 2989 { 2990 atomic_dec(&ppp_unit_count); 2991 2992 if (!ppp->file.dead || ppp->n_channels) { 2993 /* "can't happen" */ 2994 netdev_err(ppp->dev, "ppp: destroying ppp struct %p " 2995 "but dead=%d n_channels=%d !\n", 2996 ppp, ppp->file.dead, ppp->n_channels); 2997 return; 2998 } 2999 3000 ppp_ccp_closed(ppp); 3001 if (ppp->vj) { 3002 slhc_free(ppp->vj); 3003 ppp->vj = NULL; 3004 } 3005 skb_queue_purge(&ppp->file.xq); 3006 skb_queue_purge(&ppp->file.rq); 3007 #ifdef CONFIG_PPP_MULTILINK 3008 skb_queue_purge(&ppp->mrq); 3009 #endif /* CONFIG_PPP_MULTILINK */ 3010 #ifdef CONFIG_PPP_FILTER 3011 if (ppp->pass_filter) { 3012 bpf_prog_destroy(ppp->pass_filter); 3013 ppp->pass_filter = NULL; 3014 } 3015 3016 if (ppp->active_filter) { 3017 bpf_prog_destroy(ppp->active_filter); 3018 ppp->active_filter = NULL; 3019 } 3020 #endif /* CONFIG_PPP_FILTER */ 3021 3022 kfree_skb(ppp->xmit_pending); 3023 3024 free_netdev(ppp->dev); 3025 } 3026 3027 /* 3028 * Locate an existing ppp unit. 3029 * The caller should have locked the all_ppp_mutex. 3030 */ 3031 static struct ppp * 3032 ppp_find_unit(struct ppp_net *pn, int unit) 3033 { 3034 return unit_find(&pn->units_idr, unit); 3035 } 3036 3037 /* 3038 * Locate an existing ppp channel. 3039 * The caller should have locked the all_channels_lock. 3040 * First we look in the new_channels list, then in the 3041 * all_channels list. If found in the new_channels list, 3042 * we move it to the all_channels list. This is for speed 3043 * when we have a lot of channels in use. 3044 */ 3045 static struct channel * 3046 ppp_find_channel(struct ppp_net *pn, int unit) 3047 { 3048 struct channel *pch; 3049 3050 list_for_each_entry(pch, &pn->new_channels, list) { 3051 if (pch->file.index == unit) { 3052 list_move(&pch->list, &pn->all_channels); 3053 return pch; 3054 } 3055 } 3056 3057 list_for_each_entry(pch, &pn->all_channels, list) { 3058 if (pch->file.index == unit) 3059 return pch; 3060 } 3061 3062 return NULL; 3063 } 3064 3065 /* 3066 * Connect a PPP channel to a PPP interface unit. 3067 */ 3068 static int 3069 ppp_connect_channel(struct channel *pch, int unit) 3070 { 3071 struct ppp *ppp; 3072 struct ppp_net *pn; 3073 int ret = -ENXIO; 3074 int hdrlen; 3075 3076 pn = ppp_pernet(pch->chan_net); 3077 3078 mutex_lock(&pn->all_ppp_mutex); 3079 ppp = ppp_find_unit(pn, unit); 3080 if (!ppp) 3081 goto out; 3082 write_lock_bh(&pch->upl); 3083 ret = -EINVAL; 3084 if (pch->ppp) 3085 goto outl; 3086 3087 ppp_lock(ppp); 3088 if (pch->file.hdrlen > ppp->file.hdrlen) 3089 ppp->file.hdrlen = pch->file.hdrlen; 3090 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */ 3091 if (hdrlen > ppp->dev->hard_header_len) 3092 ppp->dev->hard_header_len = hdrlen; 3093 list_add_tail(&pch->clist, &ppp->channels); 3094 ++ppp->n_channels; 3095 pch->ppp = ppp; 3096 atomic_inc(&ppp->file.refcnt); 3097 ppp_unlock(ppp); 3098 ret = 0; 3099 3100 outl: 3101 write_unlock_bh(&pch->upl); 3102 out: 3103 mutex_unlock(&pn->all_ppp_mutex); 3104 return ret; 3105 } 3106 3107 /* 3108 * Disconnect a channel from its ppp unit. 3109 */ 3110 static int 3111 ppp_disconnect_channel(struct channel *pch) 3112 { 3113 struct ppp *ppp; 3114 int err = -EINVAL; 3115 3116 write_lock_bh(&pch->upl); 3117 ppp = pch->ppp; 3118 pch->ppp = NULL; 3119 write_unlock_bh(&pch->upl); 3120 if (ppp) { 3121 /* remove it from the ppp unit's list */ 3122 ppp_lock(ppp); 3123 list_del(&pch->clist); 3124 if (--ppp->n_channels == 0) 3125 wake_up_interruptible(&ppp->file.rwait); 3126 ppp_unlock(ppp); 3127 if (atomic_dec_and_test(&ppp->file.refcnt)) 3128 ppp_destroy_interface(ppp); 3129 err = 0; 3130 } 3131 return err; 3132 } 3133 3134 /* 3135 * Free up the resources used by a ppp channel. 3136 */ 3137 static void ppp_destroy_channel(struct channel *pch) 3138 { 3139 atomic_dec(&channel_count); 3140 3141 if (!pch->file.dead) { 3142 /* "can't happen" */ 3143 pr_err("ppp: destroying undead channel %p !\n", pch); 3144 return; 3145 } 3146 skb_queue_purge(&pch->file.xq); 3147 skb_queue_purge(&pch->file.rq); 3148 kfree(pch); 3149 } 3150 3151 static void __exit ppp_cleanup(void) 3152 { 3153 /* should never happen */ 3154 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count)) 3155 pr_err("PPP: removing module but units remain!\n"); 3156 rtnl_link_unregister(&ppp_link_ops); 3157 unregister_chrdev(PPP_MAJOR, "ppp"); 3158 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0)); 3159 class_destroy(ppp_class); 3160 unregister_pernet_device(&ppp_net_ops); 3161 } 3162 3163 /* 3164 * Units handling. Caller must protect concurrent access 3165 * by holding all_ppp_mutex 3166 */ 3167 3168 /* associate pointer with specified number */ 3169 static int unit_set(struct idr *p, void *ptr, int n) 3170 { 3171 int unit; 3172 3173 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL); 3174 if (unit == -ENOSPC) 3175 unit = -EINVAL; 3176 return unit; 3177 } 3178 3179 /* get new free unit number and associate pointer with it */ 3180 static int unit_get(struct idr *p, void *ptr) 3181 { 3182 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL); 3183 } 3184 3185 /* put unit number back to a pool */ 3186 static void unit_put(struct idr *p, int n) 3187 { 3188 idr_remove(p, n); 3189 } 3190 3191 /* get pointer associated with the number */ 3192 static void *unit_find(struct idr *p, int n) 3193 { 3194 return idr_find(p, n); 3195 } 3196 3197 /* Module/initialization stuff */ 3198 3199 module_init(ppp_init); 3200 module_exit(ppp_cleanup); 3201 3202 EXPORT_SYMBOL(ppp_register_net_channel); 3203 EXPORT_SYMBOL(ppp_register_channel); 3204 EXPORT_SYMBOL(ppp_unregister_channel); 3205 EXPORT_SYMBOL(ppp_channel_index); 3206 EXPORT_SYMBOL(ppp_unit_number); 3207 EXPORT_SYMBOL(ppp_dev_name); 3208 EXPORT_SYMBOL(ppp_input); 3209 EXPORT_SYMBOL(ppp_input_error); 3210 EXPORT_SYMBOL(ppp_output_wakeup); 3211 EXPORT_SYMBOL(ppp_register_compressor); 3212 EXPORT_SYMBOL(ppp_unregister_compressor); 3213 MODULE_LICENSE("GPL"); 3214 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0); 3215 MODULE_ALIAS_RTNL_LINK("ppp"); 3216 MODULE_ALIAS("devname:ppp"); 3217