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/if_ppp.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 <asm/unaligned.h> 50 #include <net/slhc_vj.h> 51 #include <linux/atomic.h> 52 53 #include <linux/nsproxy.h> 54 #include <net/net_namespace.h> 55 #include <net/netns/generic.h> 56 57 #define PPP_VERSION "2.4.2" 58 59 /* 60 * Network protocols we support. 61 */ 62 #define NP_IP 0 /* Internet Protocol V4 */ 63 #define NP_IPV6 1 /* Internet Protocol V6 */ 64 #define NP_IPX 2 /* IPX protocol */ 65 #define NP_AT 3 /* Appletalk protocol */ 66 #define NP_MPLS_UC 4 /* MPLS unicast */ 67 #define NP_MPLS_MC 5 /* MPLS multicast */ 68 #define NUM_NP 6 /* Number of NPs. */ 69 70 #define MPHDRLEN 6 /* multilink protocol header length */ 71 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */ 72 73 /* 74 * An instance of /dev/ppp can be associated with either a ppp 75 * interface unit or a ppp channel. In both cases, file->private_data 76 * points to one of these. 77 */ 78 struct ppp_file { 79 enum { 80 INTERFACE=1, CHANNEL 81 } kind; 82 struct sk_buff_head xq; /* pppd transmit queue */ 83 struct sk_buff_head rq; /* receive queue for pppd */ 84 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */ 85 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */ 86 int hdrlen; /* space to leave for headers */ 87 int index; /* interface unit / channel number */ 88 int dead; /* unit/channel has been shut down */ 89 }; 90 91 #define PF_TO_X(pf, X) container_of(pf, X, file) 92 93 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp) 94 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel) 95 96 /* 97 * Data structure describing one ppp unit. 98 * A ppp unit corresponds to a ppp network interface device 99 * and represents a multilink bundle. 100 * It can have 0 or more ppp channels connected to it. 101 */ 102 struct ppp { 103 struct ppp_file file; /* stuff for read/write/poll 0 */ 104 struct file *owner; /* file that owns this unit 48 */ 105 struct list_head channels; /* list of attached channels 4c */ 106 int n_channels; /* how many channels are attached 54 */ 107 spinlock_t rlock; /* lock for receive side 58 */ 108 spinlock_t wlock; /* lock for transmit side 5c */ 109 int mru; /* max receive unit 60 */ 110 unsigned int flags; /* control bits 64 */ 111 unsigned int xstate; /* transmit state bits 68 */ 112 unsigned int rstate; /* receive state bits 6c */ 113 int debug; /* debug flags 70 */ 114 struct slcompress *vj; /* state for VJ header compression */ 115 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */ 116 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */ 117 struct compressor *xcomp; /* transmit packet compressor 8c */ 118 void *xc_state; /* its internal state 90 */ 119 struct compressor *rcomp; /* receive decompressor 94 */ 120 void *rc_state; /* its internal state 98 */ 121 unsigned long last_xmit; /* jiffies when last pkt sent 9c */ 122 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */ 123 struct net_device *dev; /* network interface device a4 */ 124 int closing; /* is device closing down? a8 */ 125 #ifdef CONFIG_PPP_MULTILINK 126 int nxchan; /* next channel to send something on */ 127 u32 nxseq; /* next sequence number to send */ 128 int mrru; /* MP: max reconst. receive unit */ 129 u32 nextseq; /* MP: seq no of next packet */ 130 u32 minseq; /* MP: min of most recent seqnos */ 131 struct sk_buff_head mrq; /* MP: receive reconstruction queue */ 132 #endif /* CONFIG_PPP_MULTILINK */ 133 #ifdef CONFIG_PPP_FILTER 134 struct sock_filter *pass_filter; /* filter for packets to pass */ 135 struct sock_filter *active_filter;/* filter for pkts to reset idle */ 136 unsigned pass_len, active_len; 137 #endif /* CONFIG_PPP_FILTER */ 138 struct net *ppp_net; /* the net we belong to */ 139 }; 140 141 /* 142 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC, 143 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP, 144 * SC_MUST_COMP 145 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR. 146 * Bits in xstate: SC_COMP_RUN 147 */ 148 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \ 149 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \ 150 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP) 151 152 /* 153 * Private data structure for each channel. 154 * This includes the data structure used for multilink. 155 */ 156 struct channel { 157 struct ppp_file file; /* stuff for read/write/poll */ 158 struct list_head list; /* link in all/new_channels list */ 159 struct ppp_channel *chan; /* public channel data structure */ 160 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */ 161 spinlock_t downl; /* protects `chan', file.xq dequeue */ 162 struct ppp *ppp; /* ppp unit we're connected to */ 163 struct net *chan_net; /* the net channel belongs to */ 164 struct list_head clist; /* link in list of channels per unit */ 165 rwlock_t upl; /* protects `ppp' */ 166 #ifdef CONFIG_PPP_MULTILINK 167 u8 avail; /* flag used in multilink stuff */ 168 u8 had_frag; /* >= 1 fragments have been sent */ 169 u32 lastseq; /* MP: last sequence # received */ 170 int speed; /* speed of the corresponding ppp channel*/ 171 #endif /* CONFIG_PPP_MULTILINK */ 172 }; 173 174 /* 175 * SMP locking issues: 176 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels 177 * list and the ppp.n_channels field, you need to take both locks 178 * before you modify them. 179 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock -> 180 * channel.downl. 181 */ 182 183 static DEFINE_MUTEX(ppp_mutex); 184 static atomic_t ppp_unit_count = ATOMIC_INIT(0); 185 static atomic_t channel_count = ATOMIC_INIT(0); 186 187 /* per-net private data for this module */ 188 static int ppp_net_id __read_mostly; 189 struct ppp_net { 190 /* units to ppp mapping */ 191 struct idr units_idr; 192 193 /* 194 * all_ppp_mutex protects the units_idr mapping. 195 * It also ensures that finding a ppp unit in the units_idr 196 * map and updating its file.refcnt field is atomic. 197 */ 198 struct mutex all_ppp_mutex; 199 200 /* channels */ 201 struct list_head all_channels; 202 struct list_head new_channels; 203 int last_channel_index; 204 205 /* 206 * all_channels_lock protects all_channels and 207 * last_channel_index, and the atomicity of find 208 * a channel and updating its file.refcnt field. 209 */ 210 spinlock_t all_channels_lock; 211 }; 212 213 /* Get the PPP protocol number from a skb */ 214 #define PPP_PROTO(skb) get_unaligned_be16((skb)->data) 215 216 /* We limit the length of ppp->file.rq to this (arbitrary) value */ 217 #define PPP_MAX_RQLEN 32 218 219 /* 220 * Maximum number of multilink fragments queued up. 221 * This has to be large enough to cope with the maximum latency of 222 * the slowest channel relative to the others. Strictly it should 223 * depend on the number of channels and their characteristics. 224 */ 225 #define PPP_MP_MAX_QLEN 128 226 227 /* Multilink header bits. */ 228 #define B 0x80 /* this fragment begins a packet */ 229 #define E 0x40 /* this fragment ends a packet */ 230 231 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */ 232 #define seq_before(a, b) ((s32)((a) - (b)) < 0) 233 #define seq_after(a, b) ((s32)((a) - (b)) > 0) 234 235 /* Prototypes. */ 236 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 237 struct file *file, unsigned int cmd, unsigned long arg); 238 static void ppp_xmit_process(struct ppp *ppp); 239 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb); 240 static void ppp_push(struct ppp *ppp); 241 static void ppp_channel_push(struct channel *pch); 242 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, 243 struct channel *pch); 244 static void ppp_receive_error(struct ppp *ppp); 245 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb); 246 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp, 247 struct sk_buff *skb); 248 #ifdef CONFIG_PPP_MULTILINK 249 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, 250 struct channel *pch); 251 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb); 252 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp); 253 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb); 254 #endif /* CONFIG_PPP_MULTILINK */ 255 static int ppp_set_compress(struct ppp *ppp, unsigned long arg); 256 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound); 257 static void ppp_ccp_closed(struct ppp *ppp); 258 static struct compressor *find_compressor(int type); 259 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st); 260 static struct ppp *ppp_create_interface(struct net *net, int unit, int *retp); 261 static void init_ppp_file(struct ppp_file *pf, int kind); 262 static void ppp_shutdown_interface(struct ppp *ppp); 263 static void ppp_destroy_interface(struct ppp *ppp); 264 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit); 265 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit); 266 static int ppp_connect_channel(struct channel *pch, int unit); 267 static int ppp_disconnect_channel(struct channel *pch); 268 static void ppp_destroy_channel(struct channel *pch); 269 static int unit_get(struct idr *p, void *ptr); 270 static int unit_set(struct idr *p, void *ptr, int n); 271 static void unit_put(struct idr *p, int n); 272 static void *unit_find(struct idr *p, int n); 273 274 static struct class *ppp_class; 275 276 /* per net-namespace data */ 277 static inline struct ppp_net *ppp_pernet(struct net *net) 278 { 279 BUG_ON(!net); 280 281 return net_generic(net, ppp_net_id); 282 } 283 284 /* Translates a PPP protocol number to a NP index (NP == network protocol) */ 285 static inline int proto_to_npindex(int proto) 286 { 287 switch (proto) { 288 case PPP_IP: 289 return NP_IP; 290 case PPP_IPV6: 291 return NP_IPV6; 292 case PPP_IPX: 293 return NP_IPX; 294 case PPP_AT: 295 return NP_AT; 296 case PPP_MPLS_UC: 297 return NP_MPLS_UC; 298 case PPP_MPLS_MC: 299 return NP_MPLS_MC; 300 } 301 return -EINVAL; 302 } 303 304 /* Translates an NP index into a PPP protocol number */ 305 static const int npindex_to_proto[NUM_NP] = { 306 PPP_IP, 307 PPP_IPV6, 308 PPP_IPX, 309 PPP_AT, 310 PPP_MPLS_UC, 311 PPP_MPLS_MC, 312 }; 313 314 /* Translates an ethertype into an NP index */ 315 static inline int ethertype_to_npindex(int ethertype) 316 { 317 switch (ethertype) { 318 case ETH_P_IP: 319 return NP_IP; 320 case ETH_P_IPV6: 321 return NP_IPV6; 322 case ETH_P_IPX: 323 return NP_IPX; 324 case ETH_P_PPPTALK: 325 case ETH_P_ATALK: 326 return NP_AT; 327 case ETH_P_MPLS_UC: 328 return NP_MPLS_UC; 329 case ETH_P_MPLS_MC: 330 return NP_MPLS_MC; 331 } 332 return -1; 333 } 334 335 /* Translates an NP index into an ethertype */ 336 static const int npindex_to_ethertype[NUM_NP] = { 337 ETH_P_IP, 338 ETH_P_IPV6, 339 ETH_P_IPX, 340 ETH_P_PPPTALK, 341 ETH_P_MPLS_UC, 342 ETH_P_MPLS_MC, 343 }; 344 345 /* 346 * Locking shorthand. 347 */ 348 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock) 349 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock) 350 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock) 351 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock) 352 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \ 353 ppp_recv_lock(ppp); } while (0) 354 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \ 355 ppp_xmit_unlock(ppp); } while (0) 356 357 /* 358 * /dev/ppp device routines. 359 * The /dev/ppp device is used by pppd to control the ppp unit. 360 * It supports the read, write, ioctl and poll functions. 361 * Open instances of /dev/ppp can be in one of three states: 362 * unattached, attached to a ppp unit, or attached to a ppp channel. 363 */ 364 static int ppp_open(struct inode *inode, struct file *file) 365 { 366 /* 367 * This could (should?) be enforced by the permissions on /dev/ppp. 368 */ 369 if (!capable(CAP_NET_ADMIN)) 370 return -EPERM; 371 return 0; 372 } 373 374 static int ppp_release(struct inode *unused, struct file *file) 375 { 376 struct ppp_file *pf = file->private_data; 377 struct ppp *ppp; 378 379 if (pf) { 380 file->private_data = NULL; 381 if (pf->kind == INTERFACE) { 382 ppp = PF_TO_PPP(pf); 383 if (file == ppp->owner) 384 ppp_shutdown_interface(ppp); 385 } 386 if (atomic_dec_and_test(&pf->refcnt)) { 387 switch (pf->kind) { 388 case INTERFACE: 389 ppp_destroy_interface(PF_TO_PPP(pf)); 390 break; 391 case CHANNEL: 392 ppp_destroy_channel(PF_TO_CHANNEL(pf)); 393 break; 394 } 395 } 396 } 397 return 0; 398 } 399 400 static ssize_t ppp_read(struct file *file, char __user *buf, 401 size_t count, loff_t *ppos) 402 { 403 struct ppp_file *pf = file->private_data; 404 DECLARE_WAITQUEUE(wait, current); 405 ssize_t ret; 406 struct sk_buff *skb = NULL; 407 struct iovec iov; 408 409 ret = count; 410 411 if (!pf) 412 return -ENXIO; 413 add_wait_queue(&pf->rwait, &wait); 414 for (;;) { 415 set_current_state(TASK_INTERRUPTIBLE); 416 skb = skb_dequeue(&pf->rq); 417 if (skb) 418 break; 419 ret = 0; 420 if (pf->dead) 421 break; 422 if (pf->kind == INTERFACE) { 423 /* 424 * Return 0 (EOF) on an interface that has no 425 * channels connected, unless it is looping 426 * network traffic (demand mode). 427 */ 428 struct ppp *ppp = PF_TO_PPP(pf); 429 if (ppp->n_channels == 0 && 430 (ppp->flags & SC_LOOP_TRAFFIC) == 0) 431 break; 432 } 433 ret = -EAGAIN; 434 if (file->f_flags & O_NONBLOCK) 435 break; 436 ret = -ERESTARTSYS; 437 if (signal_pending(current)) 438 break; 439 schedule(); 440 } 441 set_current_state(TASK_RUNNING); 442 remove_wait_queue(&pf->rwait, &wait); 443 444 if (!skb) 445 goto out; 446 447 ret = -EOVERFLOW; 448 if (skb->len > count) 449 goto outf; 450 ret = -EFAULT; 451 iov.iov_base = buf; 452 iov.iov_len = count; 453 if (skb_copy_datagram_iovec(skb, 0, &iov, skb->len)) 454 goto outf; 455 ret = skb->len; 456 457 outf: 458 kfree_skb(skb); 459 out: 460 return ret; 461 } 462 463 static ssize_t ppp_write(struct file *file, const char __user *buf, 464 size_t count, loff_t *ppos) 465 { 466 struct ppp_file *pf = file->private_data; 467 struct sk_buff *skb; 468 ssize_t ret; 469 470 if (!pf) 471 return -ENXIO; 472 ret = -ENOMEM; 473 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL); 474 if (!skb) 475 goto out; 476 skb_reserve(skb, pf->hdrlen); 477 ret = -EFAULT; 478 if (copy_from_user(skb_put(skb, count), buf, count)) { 479 kfree_skb(skb); 480 goto out; 481 } 482 483 skb_queue_tail(&pf->xq, skb); 484 485 switch (pf->kind) { 486 case INTERFACE: 487 ppp_xmit_process(PF_TO_PPP(pf)); 488 break; 489 case CHANNEL: 490 ppp_channel_push(PF_TO_CHANNEL(pf)); 491 break; 492 } 493 494 ret = count; 495 496 out: 497 return ret; 498 } 499 500 /* No kernel lock - fine */ 501 static unsigned int ppp_poll(struct file *file, poll_table *wait) 502 { 503 struct ppp_file *pf = file->private_data; 504 unsigned int mask; 505 506 if (!pf) 507 return 0; 508 poll_wait(file, &pf->rwait, wait); 509 mask = POLLOUT | POLLWRNORM; 510 if (skb_peek(&pf->rq)) 511 mask |= POLLIN | POLLRDNORM; 512 if (pf->dead) 513 mask |= POLLHUP; 514 else if (pf->kind == INTERFACE) { 515 /* see comment in ppp_read */ 516 struct ppp *ppp = PF_TO_PPP(pf); 517 if (ppp->n_channels == 0 && 518 (ppp->flags & SC_LOOP_TRAFFIC) == 0) 519 mask |= POLLIN | POLLRDNORM; 520 } 521 522 return mask; 523 } 524 525 #ifdef CONFIG_PPP_FILTER 526 static int get_filter(void __user *arg, struct sock_filter **p) 527 { 528 struct sock_fprog uprog; 529 struct sock_filter *code = NULL; 530 int len, err; 531 532 if (copy_from_user(&uprog, arg, sizeof(uprog))) 533 return -EFAULT; 534 535 if (!uprog.len) { 536 *p = NULL; 537 return 0; 538 } 539 540 len = uprog.len * sizeof(struct sock_filter); 541 code = memdup_user(uprog.filter, len); 542 if (IS_ERR(code)) 543 return PTR_ERR(code); 544 545 err = sk_chk_filter(code, uprog.len); 546 if (err) { 547 kfree(code); 548 return err; 549 } 550 551 *p = code; 552 return uprog.len; 553 } 554 #endif /* CONFIG_PPP_FILTER */ 555 556 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 557 { 558 struct ppp_file *pf = file->private_data; 559 struct ppp *ppp; 560 int err = -EFAULT, val, val2, i; 561 struct ppp_idle idle; 562 struct npioctl npi; 563 int unit, cflags; 564 struct slcompress *vj; 565 void __user *argp = (void __user *)arg; 566 int __user *p = argp; 567 568 if (!pf) 569 return ppp_unattached_ioctl(current->nsproxy->net_ns, 570 pf, file, cmd, arg); 571 572 if (cmd == PPPIOCDETACH) { 573 /* 574 * We have to be careful here... if the file descriptor 575 * has been dup'd, we could have another process in the 576 * middle of a poll using the same file *, so we had 577 * better not free the interface data structures - 578 * instead we fail the ioctl. Even in this case, we 579 * shut down the interface if we are the owner of it. 580 * Actually, we should get rid of PPPIOCDETACH, userland 581 * (i.e. pppd) could achieve the same effect by closing 582 * this fd and reopening /dev/ppp. 583 */ 584 err = -EINVAL; 585 mutex_lock(&ppp_mutex); 586 if (pf->kind == INTERFACE) { 587 ppp = PF_TO_PPP(pf); 588 if (file == ppp->owner) 589 ppp_shutdown_interface(ppp); 590 } 591 if (atomic_long_read(&file->f_count) <= 2) { 592 ppp_release(NULL, file); 593 err = 0; 594 } else 595 pr_warn("PPPIOCDETACH file->f_count=%ld\n", 596 atomic_long_read(&file->f_count)); 597 mutex_unlock(&ppp_mutex); 598 return err; 599 } 600 601 if (pf->kind == CHANNEL) { 602 struct channel *pch; 603 struct ppp_channel *chan; 604 605 mutex_lock(&ppp_mutex); 606 pch = PF_TO_CHANNEL(pf); 607 608 switch (cmd) { 609 case PPPIOCCONNECT: 610 if (get_user(unit, p)) 611 break; 612 err = ppp_connect_channel(pch, unit); 613 break; 614 615 case PPPIOCDISCONN: 616 err = ppp_disconnect_channel(pch); 617 break; 618 619 default: 620 down_read(&pch->chan_sem); 621 chan = pch->chan; 622 err = -ENOTTY; 623 if (chan && chan->ops->ioctl) 624 err = chan->ops->ioctl(chan, cmd, arg); 625 up_read(&pch->chan_sem); 626 } 627 mutex_unlock(&ppp_mutex); 628 return err; 629 } 630 631 if (pf->kind != INTERFACE) { 632 /* can't happen */ 633 pr_err("PPP: not interface or channel??\n"); 634 return -EINVAL; 635 } 636 637 mutex_lock(&ppp_mutex); 638 ppp = PF_TO_PPP(pf); 639 switch (cmd) { 640 case PPPIOCSMRU: 641 if (get_user(val, p)) 642 break; 643 ppp->mru = val; 644 err = 0; 645 break; 646 647 case PPPIOCSFLAGS: 648 if (get_user(val, p)) 649 break; 650 ppp_lock(ppp); 651 cflags = ppp->flags & ~val; 652 ppp->flags = val & SC_FLAG_BITS; 653 ppp_unlock(ppp); 654 if (cflags & SC_CCP_OPEN) 655 ppp_ccp_closed(ppp); 656 err = 0; 657 break; 658 659 case PPPIOCGFLAGS: 660 val = ppp->flags | ppp->xstate | ppp->rstate; 661 if (put_user(val, p)) 662 break; 663 err = 0; 664 break; 665 666 case PPPIOCSCOMPRESS: 667 err = ppp_set_compress(ppp, arg); 668 break; 669 670 case PPPIOCGUNIT: 671 if (put_user(ppp->file.index, p)) 672 break; 673 err = 0; 674 break; 675 676 case PPPIOCSDEBUG: 677 if (get_user(val, p)) 678 break; 679 ppp->debug = val; 680 err = 0; 681 break; 682 683 case PPPIOCGDEBUG: 684 if (put_user(ppp->debug, p)) 685 break; 686 err = 0; 687 break; 688 689 case PPPIOCGIDLE: 690 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ; 691 idle.recv_idle = (jiffies - ppp->last_recv) / HZ; 692 if (copy_to_user(argp, &idle, sizeof(idle))) 693 break; 694 err = 0; 695 break; 696 697 case PPPIOCSMAXCID: 698 if (get_user(val, p)) 699 break; 700 val2 = 15; 701 if ((val >> 16) != 0) { 702 val2 = val >> 16; 703 val &= 0xffff; 704 } 705 vj = slhc_init(val2+1, val+1); 706 if (!vj) { 707 netdev_err(ppp->dev, 708 "PPP: no memory (VJ compressor)\n"); 709 err = -ENOMEM; 710 break; 711 } 712 ppp_lock(ppp); 713 if (ppp->vj) 714 slhc_free(ppp->vj); 715 ppp->vj = vj; 716 ppp_unlock(ppp); 717 err = 0; 718 break; 719 720 case PPPIOCGNPMODE: 721 case PPPIOCSNPMODE: 722 if (copy_from_user(&npi, argp, sizeof(npi))) 723 break; 724 err = proto_to_npindex(npi.protocol); 725 if (err < 0) 726 break; 727 i = err; 728 if (cmd == PPPIOCGNPMODE) { 729 err = -EFAULT; 730 npi.mode = ppp->npmode[i]; 731 if (copy_to_user(argp, &npi, sizeof(npi))) 732 break; 733 } else { 734 ppp->npmode[i] = npi.mode; 735 /* we may be able to transmit more packets now (??) */ 736 netif_wake_queue(ppp->dev); 737 } 738 err = 0; 739 break; 740 741 #ifdef CONFIG_PPP_FILTER 742 case PPPIOCSPASS: 743 { 744 struct sock_filter *code; 745 err = get_filter(argp, &code); 746 if (err >= 0) { 747 ppp_lock(ppp); 748 kfree(ppp->pass_filter); 749 ppp->pass_filter = code; 750 ppp->pass_len = err; 751 ppp_unlock(ppp); 752 err = 0; 753 } 754 break; 755 } 756 case PPPIOCSACTIVE: 757 { 758 struct sock_filter *code; 759 err = get_filter(argp, &code); 760 if (err >= 0) { 761 ppp_lock(ppp); 762 kfree(ppp->active_filter); 763 ppp->active_filter = code; 764 ppp->active_len = err; 765 ppp_unlock(ppp); 766 err = 0; 767 } 768 break; 769 } 770 #endif /* CONFIG_PPP_FILTER */ 771 772 #ifdef CONFIG_PPP_MULTILINK 773 case PPPIOCSMRRU: 774 if (get_user(val, p)) 775 break; 776 ppp_recv_lock(ppp); 777 ppp->mrru = val; 778 ppp_recv_unlock(ppp); 779 err = 0; 780 break; 781 #endif /* CONFIG_PPP_MULTILINK */ 782 783 default: 784 err = -ENOTTY; 785 } 786 mutex_unlock(&ppp_mutex); 787 return err; 788 } 789 790 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 791 struct file *file, unsigned int cmd, unsigned long arg) 792 { 793 int unit, err = -EFAULT; 794 struct ppp *ppp; 795 struct channel *chan; 796 struct ppp_net *pn; 797 int __user *p = (int __user *)arg; 798 799 mutex_lock(&ppp_mutex); 800 switch (cmd) { 801 case PPPIOCNEWUNIT: 802 /* Create a new ppp unit */ 803 if (get_user(unit, p)) 804 break; 805 ppp = ppp_create_interface(net, unit, &err); 806 if (!ppp) 807 break; 808 file->private_data = &ppp->file; 809 ppp->owner = file; 810 err = -EFAULT; 811 if (put_user(ppp->file.index, p)) 812 break; 813 err = 0; 814 break; 815 816 case PPPIOCATTACH: 817 /* Attach to an existing ppp unit */ 818 if (get_user(unit, p)) 819 break; 820 err = -ENXIO; 821 pn = ppp_pernet(net); 822 mutex_lock(&pn->all_ppp_mutex); 823 ppp = ppp_find_unit(pn, unit); 824 if (ppp) { 825 atomic_inc(&ppp->file.refcnt); 826 file->private_data = &ppp->file; 827 err = 0; 828 } 829 mutex_unlock(&pn->all_ppp_mutex); 830 break; 831 832 case PPPIOCATTCHAN: 833 if (get_user(unit, p)) 834 break; 835 err = -ENXIO; 836 pn = ppp_pernet(net); 837 spin_lock_bh(&pn->all_channels_lock); 838 chan = ppp_find_channel(pn, unit); 839 if (chan) { 840 atomic_inc(&chan->file.refcnt); 841 file->private_data = &chan->file; 842 err = 0; 843 } 844 spin_unlock_bh(&pn->all_channels_lock); 845 break; 846 847 default: 848 err = -ENOTTY; 849 } 850 mutex_unlock(&ppp_mutex); 851 return err; 852 } 853 854 static const struct file_operations ppp_device_fops = { 855 .owner = THIS_MODULE, 856 .read = ppp_read, 857 .write = ppp_write, 858 .poll = ppp_poll, 859 .unlocked_ioctl = ppp_ioctl, 860 .open = ppp_open, 861 .release = ppp_release, 862 .llseek = noop_llseek, 863 }; 864 865 static __net_init int ppp_init_net(struct net *net) 866 { 867 struct ppp_net *pn = net_generic(net, ppp_net_id); 868 869 idr_init(&pn->units_idr); 870 mutex_init(&pn->all_ppp_mutex); 871 872 INIT_LIST_HEAD(&pn->all_channels); 873 INIT_LIST_HEAD(&pn->new_channels); 874 875 spin_lock_init(&pn->all_channels_lock); 876 877 return 0; 878 } 879 880 static __net_exit void ppp_exit_net(struct net *net) 881 { 882 struct ppp_net *pn = net_generic(net, ppp_net_id); 883 884 idr_destroy(&pn->units_idr); 885 } 886 887 static struct pernet_operations ppp_net_ops = { 888 .init = ppp_init_net, 889 .exit = ppp_exit_net, 890 .id = &ppp_net_id, 891 .size = sizeof(struct ppp_net), 892 }; 893 894 #define PPP_MAJOR 108 895 896 /* Called at boot time if ppp is compiled into the kernel, 897 or at module load time (from init_module) if compiled as a module. */ 898 static int __init ppp_init(void) 899 { 900 int err; 901 902 pr_info("PPP generic driver version " PPP_VERSION "\n"); 903 904 err = register_pernet_device(&ppp_net_ops); 905 if (err) { 906 pr_err("failed to register PPP pernet device (%d)\n", err); 907 goto out; 908 } 909 910 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops); 911 if (err) { 912 pr_err("failed to register PPP device (%d)\n", err); 913 goto out_net; 914 } 915 916 ppp_class = class_create(THIS_MODULE, "ppp"); 917 if (IS_ERR(ppp_class)) { 918 err = PTR_ERR(ppp_class); 919 goto out_chrdev; 920 } 921 922 /* not a big deal if we fail here :-) */ 923 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp"); 924 925 return 0; 926 927 out_chrdev: 928 unregister_chrdev(PPP_MAJOR, "ppp"); 929 out_net: 930 unregister_pernet_device(&ppp_net_ops); 931 out: 932 return err; 933 } 934 935 /* 936 * Network interface unit routines. 937 */ 938 static netdev_tx_t 939 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev) 940 { 941 struct ppp *ppp = netdev_priv(dev); 942 int npi, proto; 943 unsigned char *pp; 944 945 npi = ethertype_to_npindex(ntohs(skb->protocol)); 946 if (npi < 0) 947 goto outf; 948 949 /* Drop, accept or reject the packet */ 950 switch (ppp->npmode[npi]) { 951 case NPMODE_PASS: 952 break; 953 case NPMODE_QUEUE: 954 /* it would be nice to have a way to tell the network 955 system to queue this one up for later. */ 956 goto outf; 957 case NPMODE_DROP: 958 case NPMODE_ERROR: 959 goto outf; 960 } 961 962 /* Put the 2-byte PPP protocol number on the front, 963 making sure there is room for the address and control fields. */ 964 if (skb_cow_head(skb, PPP_HDRLEN)) 965 goto outf; 966 967 pp = skb_push(skb, 2); 968 proto = npindex_to_proto[npi]; 969 put_unaligned_be16(proto, pp); 970 971 netif_stop_queue(dev); 972 skb_queue_tail(&ppp->file.xq, skb); 973 ppp_xmit_process(ppp); 974 return NETDEV_TX_OK; 975 976 outf: 977 kfree_skb(skb); 978 ++dev->stats.tx_dropped; 979 return NETDEV_TX_OK; 980 } 981 982 static int 983 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 984 { 985 struct ppp *ppp = netdev_priv(dev); 986 int err = -EFAULT; 987 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data; 988 struct ppp_stats stats; 989 struct ppp_comp_stats cstats; 990 char *vers; 991 992 switch (cmd) { 993 case SIOCGPPPSTATS: 994 ppp_get_stats(ppp, &stats); 995 if (copy_to_user(addr, &stats, sizeof(stats))) 996 break; 997 err = 0; 998 break; 999 1000 case SIOCGPPPCSTATS: 1001 memset(&cstats, 0, sizeof(cstats)); 1002 if (ppp->xc_state) 1003 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c); 1004 if (ppp->rc_state) 1005 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d); 1006 if (copy_to_user(addr, &cstats, sizeof(cstats))) 1007 break; 1008 err = 0; 1009 break; 1010 1011 case SIOCGPPPVER: 1012 vers = PPP_VERSION; 1013 if (copy_to_user(addr, vers, strlen(vers) + 1)) 1014 break; 1015 err = 0; 1016 break; 1017 1018 default: 1019 err = -EINVAL; 1020 } 1021 1022 return err; 1023 } 1024 1025 static const struct net_device_ops ppp_netdev_ops = { 1026 .ndo_start_xmit = ppp_start_xmit, 1027 .ndo_do_ioctl = ppp_net_ioctl, 1028 }; 1029 1030 static void ppp_setup(struct net_device *dev) 1031 { 1032 dev->netdev_ops = &ppp_netdev_ops; 1033 dev->hard_header_len = PPP_HDRLEN; 1034 dev->mtu = PPP_MTU; 1035 dev->addr_len = 0; 1036 dev->tx_queue_len = 3; 1037 dev->type = ARPHRD_PPP; 1038 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 1039 dev->features |= NETIF_F_NETNS_LOCAL; 1040 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 1041 } 1042 1043 /* 1044 * Transmit-side routines. 1045 */ 1046 1047 /* 1048 * Called to do any work queued up on the transmit side 1049 * that can now be done. 1050 */ 1051 static void 1052 ppp_xmit_process(struct ppp *ppp) 1053 { 1054 struct sk_buff *skb; 1055 1056 ppp_xmit_lock(ppp); 1057 if (!ppp->closing) { 1058 ppp_push(ppp); 1059 while (!ppp->xmit_pending && 1060 (skb = skb_dequeue(&ppp->file.xq))) 1061 ppp_send_frame(ppp, skb); 1062 /* If there's no work left to do, tell the core net 1063 code that we can accept some more. */ 1064 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq)) 1065 netif_wake_queue(ppp->dev); 1066 } 1067 ppp_xmit_unlock(ppp); 1068 } 1069 1070 static inline struct sk_buff * 1071 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) 1072 { 1073 struct sk_buff *new_skb; 1074 int len; 1075 int new_skb_size = ppp->dev->mtu + 1076 ppp->xcomp->comp_extra + ppp->dev->hard_header_len; 1077 int compressor_skb_size = ppp->dev->mtu + 1078 ppp->xcomp->comp_extra + PPP_HDRLEN; 1079 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC); 1080 if (!new_skb) { 1081 if (net_ratelimit()) 1082 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n"); 1083 return NULL; 1084 } 1085 if (ppp->dev->hard_header_len > PPP_HDRLEN) 1086 skb_reserve(new_skb, 1087 ppp->dev->hard_header_len - PPP_HDRLEN); 1088 1089 /* compressor still expects A/C bytes in hdr */ 1090 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, 1091 new_skb->data, skb->len + 2, 1092 compressor_skb_size); 1093 if (len > 0 && (ppp->flags & SC_CCP_UP)) { 1094 kfree_skb(skb); 1095 skb = new_skb; 1096 skb_put(skb, len); 1097 skb_pull(skb, 2); /* pull off A/C bytes */ 1098 } else if (len == 0) { 1099 /* didn't compress, or CCP not up yet */ 1100 kfree_skb(new_skb); 1101 new_skb = skb; 1102 } else { 1103 /* 1104 * (len < 0) 1105 * MPPE requires that we do not send unencrypted 1106 * frames. The compressor will return -1 if we 1107 * should drop the frame. We cannot simply test 1108 * the compress_proto because MPPE and MPPC share 1109 * the same number. 1110 */ 1111 if (net_ratelimit()) 1112 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n"); 1113 kfree_skb(skb); 1114 kfree_skb(new_skb); 1115 new_skb = NULL; 1116 } 1117 return new_skb; 1118 } 1119 1120 /* 1121 * Compress and send a frame. 1122 * The caller should have locked the xmit path, 1123 * and xmit_pending should be 0. 1124 */ 1125 static void 1126 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) 1127 { 1128 int proto = PPP_PROTO(skb); 1129 struct sk_buff *new_skb; 1130 int len; 1131 unsigned char *cp; 1132 1133 if (proto < 0x8000) { 1134 #ifdef CONFIG_PPP_FILTER 1135 /* check if we should pass this packet */ 1136 /* the filter instructions are constructed assuming 1137 a four-byte PPP header on each packet */ 1138 *skb_push(skb, 2) = 1; 1139 if (ppp->pass_filter && 1140 sk_run_filter(skb, ppp->pass_filter) == 0) { 1141 if (ppp->debug & 1) 1142 netdev_printk(KERN_DEBUG, ppp->dev, 1143 "PPP: outbound frame " 1144 "not passed\n"); 1145 kfree_skb(skb); 1146 return; 1147 } 1148 /* if this packet passes the active filter, record the time */ 1149 if (!(ppp->active_filter && 1150 sk_run_filter(skb, ppp->active_filter) == 0)) 1151 ppp->last_xmit = jiffies; 1152 skb_pull(skb, 2); 1153 #else 1154 /* for data packets, record the time */ 1155 ppp->last_xmit = jiffies; 1156 #endif /* CONFIG_PPP_FILTER */ 1157 } 1158 1159 ++ppp->dev->stats.tx_packets; 1160 ppp->dev->stats.tx_bytes += skb->len - 2; 1161 1162 switch (proto) { 1163 case PPP_IP: 1164 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0) 1165 break; 1166 /* try to do VJ TCP header compression */ 1167 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2, 1168 GFP_ATOMIC); 1169 if (!new_skb) { 1170 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n"); 1171 goto drop; 1172 } 1173 skb_reserve(new_skb, ppp->dev->hard_header_len - 2); 1174 cp = skb->data + 2; 1175 len = slhc_compress(ppp->vj, cp, skb->len - 2, 1176 new_skb->data + 2, &cp, 1177 !(ppp->flags & SC_NO_TCP_CCID)); 1178 if (cp == skb->data + 2) { 1179 /* didn't compress */ 1180 kfree_skb(new_skb); 1181 } else { 1182 if (cp[0] & SL_TYPE_COMPRESSED_TCP) { 1183 proto = PPP_VJC_COMP; 1184 cp[0] &= ~SL_TYPE_COMPRESSED_TCP; 1185 } else { 1186 proto = PPP_VJC_UNCOMP; 1187 cp[0] = skb->data[2]; 1188 } 1189 kfree_skb(skb); 1190 skb = new_skb; 1191 cp = skb_put(skb, len + 2); 1192 cp[0] = 0; 1193 cp[1] = proto; 1194 } 1195 break; 1196 1197 case PPP_CCP: 1198 /* peek at outbound CCP frames */ 1199 ppp_ccp_peek(ppp, skb, 0); 1200 break; 1201 } 1202 1203 /* try to do packet compression */ 1204 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state && 1205 proto != PPP_LCP && proto != PPP_CCP) { 1206 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) { 1207 if (net_ratelimit()) 1208 netdev_err(ppp->dev, 1209 "ppp: compression required but " 1210 "down - pkt dropped.\n"); 1211 goto drop; 1212 } 1213 skb = pad_compress_skb(ppp, skb); 1214 if (!skb) 1215 goto drop; 1216 } 1217 1218 /* 1219 * If we are waiting for traffic (demand dialling), 1220 * queue it up for pppd to receive. 1221 */ 1222 if (ppp->flags & SC_LOOP_TRAFFIC) { 1223 if (ppp->file.rq.qlen > PPP_MAX_RQLEN) 1224 goto drop; 1225 skb_queue_tail(&ppp->file.rq, skb); 1226 wake_up_interruptible(&ppp->file.rwait); 1227 return; 1228 } 1229 1230 ppp->xmit_pending = skb; 1231 ppp_push(ppp); 1232 return; 1233 1234 drop: 1235 kfree_skb(skb); 1236 ++ppp->dev->stats.tx_errors; 1237 } 1238 1239 /* 1240 * Try to send the frame in xmit_pending. 1241 * The caller should have the xmit path locked. 1242 */ 1243 static void 1244 ppp_push(struct ppp *ppp) 1245 { 1246 struct list_head *list; 1247 struct channel *pch; 1248 struct sk_buff *skb = ppp->xmit_pending; 1249 1250 if (!skb) 1251 return; 1252 1253 list = &ppp->channels; 1254 if (list_empty(list)) { 1255 /* nowhere to send the packet, just drop it */ 1256 ppp->xmit_pending = NULL; 1257 kfree_skb(skb); 1258 return; 1259 } 1260 1261 if ((ppp->flags & SC_MULTILINK) == 0) { 1262 /* not doing multilink: send it down the first channel */ 1263 list = list->next; 1264 pch = list_entry(list, struct channel, clist); 1265 1266 spin_lock_bh(&pch->downl); 1267 if (pch->chan) { 1268 if (pch->chan->ops->start_xmit(pch->chan, skb)) 1269 ppp->xmit_pending = NULL; 1270 } else { 1271 /* channel got unregistered */ 1272 kfree_skb(skb); 1273 ppp->xmit_pending = NULL; 1274 } 1275 spin_unlock_bh(&pch->downl); 1276 return; 1277 } 1278 1279 #ifdef CONFIG_PPP_MULTILINK 1280 /* Multilink: fragment the packet over as many links 1281 as can take the packet at the moment. */ 1282 if (!ppp_mp_explode(ppp, skb)) 1283 return; 1284 #endif /* CONFIG_PPP_MULTILINK */ 1285 1286 ppp->xmit_pending = NULL; 1287 kfree_skb(skb); 1288 } 1289 1290 #ifdef CONFIG_PPP_MULTILINK 1291 static bool mp_protocol_compress __read_mostly = true; 1292 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR); 1293 MODULE_PARM_DESC(mp_protocol_compress, 1294 "compress protocol id in multilink fragments"); 1295 1296 /* 1297 * Divide a packet to be transmitted into fragments and 1298 * send them out the individual links. 1299 */ 1300 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb) 1301 { 1302 int len, totlen; 1303 int i, bits, hdrlen, mtu; 1304 int flen; 1305 int navail, nfree, nzero; 1306 int nbigger; 1307 int totspeed; 1308 int totfree; 1309 unsigned char *p, *q; 1310 struct list_head *list; 1311 struct channel *pch; 1312 struct sk_buff *frag; 1313 struct ppp_channel *chan; 1314 1315 totspeed = 0; /*total bitrate of the bundle*/ 1316 nfree = 0; /* # channels which have no packet already queued */ 1317 navail = 0; /* total # of usable channels (not deregistered) */ 1318 nzero = 0; /* number of channels with zero speed associated*/ 1319 totfree = 0; /*total # of channels available and 1320 *having no queued packets before 1321 *starting the fragmentation*/ 1322 1323 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1324 i = 0; 1325 list_for_each_entry(pch, &ppp->channels, clist) { 1326 if (pch->chan) { 1327 pch->avail = 1; 1328 navail++; 1329 pch->speed = pch->chan->speed; 1330 } else { 1331 pch->avail = 0; 1332 } 1333 if (pch->avail) { 1334 if (skb_queue_empty(&pch->file.xq) || 1335 !pch->had_frag) { 1336 if (pch->speed == 0) 1337 nzero++; 1338 else 1339 totspeed += pch->speed; 1340 1341 pch->avail = 2; 1342 ++nfree; 1343 ++totfree; 1344 } 1345 if (!pch->had_frag && i < ppp->nxchan) 1346 ppp->nxchan = i; 1347 } 1348 ++i; 1349 } 1350 /* 1351 * Don't start sending this packet unless at least half of 1352 * the channels are free. This gives much better TCP 1353 * performance if we have a lot of channels. 1354 */ 1355 if (nfree == 0 || nfree < navail / 2) 1356 return 0; /* can't take now, leave it in xmit_pending */ 1357 1358 /* Do protocol field compression */ 1359 p = skb->data; 1360 len = skb->len; 1361 if (*p == 0 && mp_protocol_compress) { 1362 ++p; 1363 --len; 1364 } 1365 1366 totlen = len; 1367 nbigger = len % nfree; 1368 1369 /* skip to the channel after the one we last used 1370 and start at that one */ 1371 list = &ppp->channels; 1372 for (i = 0; i < ppp->nxchan; ++i) { 1373 list = list->next; 1374 if (list == &ppp->channels) { 1375 i = 0; 1376 break; 1377 } 1378 } 1379 1380 /* create a fragment for each channel */ 1381 bits = B; 1382 while (len > 0) { 1383 list = list->next; 1384 if (list == &ppp->channels) { 1385 i = 0; 1386 continue; 1387 } 1388 pch = list_entry(list, struct channel, clist); 1389 ++i; 1390 if (!pch->avail) 1391 continue; 1392 1393 /* 1394 * Skip this channel if it has a fragment pending already and 1395 * we haven't given a fragment to all of the free channels. 1396 */ 1397 if (pch->avail == 1) { 1398 if (nfree > 0) 1399 continue; 1400 } else { 1401 pch->avail = 1; 1402 } 1403 1404 /* check the channel's mtu and whether it is still attached. */ 1405 spin_lock_bh(&pch->downl); 1406 if (pch->chan == NULL) { 1407 /* can't use this channel, it's being deregistered */ 1408 if (pch->speed == 0) 1409 nzero--; 1410 else 1411 totspeed -= pch->speed; 1412 1413 spin_unlock_bh(&pch->downl); 1414 pch->avail = 0; 1415 totlen = len; 1416 totfree--; 1417 nfree--; 1418 if (--navail == 0) 1419 break; 1420 continue; 1421 } 1422 1423 /* 1424 *if the channel speed is not set divide 1425 *the packet evenly among the free channels; 1426 *otherwise divide it according to the speed 1427 *of the channel we are going to transmit on 1428 */ 1429 flen = len; 1430 if (nfree > 0) { 1431 if (pch->speed == 0) { 1432 flen = len/nfree; 1433 if (nbigger > 0) { 1434 flen++; 1435 nbigger--; 1436 } 1437 } else { 1438 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) / 1439 ((totspeed*totfree)/pch->speed)) - hdrlen; 1440 if (nbigger > 0) { 1441 flen += ((totfree - nzero)*pch->speed)/totspeed; 1442 nbigger -= ((totfree - nzero)*pch->speed)/ 1443 totspeed; 1444 } 1445 } 1446 nfree--; 1447 } 1448 1449 /* 1450 *check if we are on the last channel or 1451 *we exceded the length of the data to 1452 *fragment 1453 */ 1454 if ((nfree <= 0) || (flen > len)) 1455 flen = len; 1456 /* 1457 *it is not worth to tx on slow channels: 1458 *in that case from the resulting flen according to the 1459 *above formula will be equal or less than zero. 1460 *Skip the channel in this case 1461 */ 1462 if (flen <= 0) { 1463 pch->avail = 2; 1464 spin_unlock_bh(&pch->downl); 1465 continue; 1466 } 1467 1468 /* 1469 * hdrlen includes the 2-byte PPP protocol field, but the 1470 * MTU counts only the payload excluding the protocol field. 1471 * (RFC1661 Section 2) 1472 */ 1473 mtu = pch->chan->mtu - (hdrlen - 2); 1474 if (mtu < 4) 1475 mtu = 4; 1476 if (flen > mtu) 1477 flen = mtu; 1478 if (flen == len) 1479 bits |= E; 1480 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC); 1481 if (!frag) 1482 goto noskb; 1483 q = skb_put(frag, flen + hdrlen); 1484 1485 /* make the MP header */ 1486 put_unaligned_be16(PPP_MP, q); 1487 if (ppp->flags & SC_MP_XSHORTSEQ) { 1488 q[2] = bits + ((ppp->nxseq >> 8) & 0xf); 1489 q[3] = ppp->nxseq; 1490 } else { 1491 q[2] = bits; 1492 q[3] = ppp->nxseq >> 16; 1493 q[4] = ppp->nxseq >> 8; 1494 q[5] = ppp->nxseq; 1495 } 1496 1497 memcpy(q + hdrlen, p, flen); 1498 1499 /* try to send it down the channel */ 1500 chan = pch->chan; 1501 if (!skb_queue_empty(&pch->file.xq) || 1502 !chan->ops->start_xmit(chan, frag)) 1503 skb_queue_tail(&pch->file.xq, frag); 1504 pch->had_frag = 1; 1505 p += flen; 1506 len -= flen; 1507 ++ppp->nxseq; 1508 bits = 0; 1509 spin_unlock_bh(&pch->downl); 1510 } 1511 ppp->nxchan = i; 1512 1513 return 1; 1514 1515 noskb: 1516 spin_unlock_bh(&pch->downl); 1517 if (ppp->debug & 1) 1518 netdev_err(ppp->dev, "PPP: no memory (fragment)\n"); 1519 ++ppp->dev->stats.tx_errors; 1520 ++ppp->nxseq; 1521 return 1; /* abandon the frame */ 1522 } 1523 #endif /* CONFIG_PPP_MULTILINK */ 1524 1525 /* 1526 * Try to send data out on a channel. 1527 */ 1528 static void 1529 ppp_channel_push(struct channel *pch) 1530 { 1531 struct sk_buff *skb; 1532 struct ppp *ppp; 1533 1534 spin_lock_bh(&pch->downl); 1535 if (pch->chan) { 1536 while (!skb_queue_empty(&pch->file.xq)) { 1537 skb = skb_dequeue(&pch->file.xq); 1538 if (!pch->chan->ops->start_xmit(pch->chan, skb)) { 1539 /* put the packet back and try again later */ 1540 skb_queue_head(&pch->file.xq, skb); 1541 break; 1542 } 1543 } 1544 } else { 1545 /* channel got deregistered */ 1546 skb_queue_purge(&pch->file.xq); 1547 } 1548 spin_unlock_bh(&pch->downl); 1549 /* see if there is anything from the attached unit to be sent */ 1550 if (skb_queue_empty(&pch->file.xq)) { 1551 read_lock_bh(&pch->upl); 1552 ppp = pch->ppp; 1553 if (ppp) 1554 ppp_xmit_process(ppp); 1555 read_unlock_bh(&pch->upl); 1556 } 1557 } 1558 1559 /* 1560 * Receive-side routines. 1561 */ 1562 1563 struct ppp_mp_skb_parm { 1564 u32 sequence; 1565 u8 BEbits; 1566 }; 1567 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb)) 1568 1569 static inline void 1570 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1571 { 1572 ppp_recv_lock(ppp); 1573 if (!ppp->closing) 1574 ppp_receive_frame(ppp, skb, pch); 1575 else 1576 kfree_skb(skb); 1577 ppp_recv_unlock(ppp); 1578 } 1579 1580 void 1581 ppp_input(struct ppp_channel *chan, struct sk_buff *skb) 1582 { 1583 struct channel *pch = chan->ppp; 1584 int proto; 1585 1586 if (!pch) { 1587 kfree_skb(skb); 1588 return; 1589 } 1590 1591 read_lock_bh(&pch->upl); 1592 if (!pskb_may_pull(skb, 2)) { 1593 kfree_skb(skb); 1594 if (pch->ppp) { 1595 ++pch->ppp->dev->stats.rx_length_errors; 1596 ppp_receive_error(pch->ppp); 1597 } 1598 goto done; 1599 } 1600 1601 proto = PPP_PROTO(skb); 1602 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) { 1603 /* put it on the channel queue */ 1604 skb_queue_tail(&pch->file.rq, skb); 1605 /* drop old frames if queue too long */ 1606 while (pch->file.rq.qlen > PPP_MAX_RQLEN && 1607 (skb = skb_dequeue(&pch->file.rq))) 1608 kfree_skb(skb); 1609 wake_up_interruptible(&pch->file.rwait); 1610 } else { 1611 ppp_do_recv(pch->ppp, skb, pch); 1612 } 1613 1614 done: 1615 read_unlock_bh(&pch->upl); 1616 } 1617 1618 /* Put a 0-length skb in the receive queue as an error indication */ 1619 void 1620 ppp_input_error(struct ppp_channel *chan, int code) 1621 { 1622 struct channel *pch = chan->ppp; 1623 struct sk_buff *skb; 1624 1625 if (!pch) 1626 return; 1627 1628 read_lock_bh(&pch->upl); 1629 if (pch->ppp) { 1630 skb = alloc_skb(0, GFP_ATOMIC); 1631 if (skb) { 1632 skb->len = 0; /* probably unnecessary */ 1633 skb->cb[0] = code; 1634 ppp_do_recv(pch->ppp, skb, pch); 1635 } 1636 } 1637 read_unlock_bh(&pch->upl); 1638 } 1639 1640 /* 1641 * We come in here to process a received frame. 1642 * The receive side of the ppp unit is locked. 1643 */ 1644 static void 1645 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1646 { 1647 /* note: a 0-length skb is used as an error indication */ 1648 if (skb->len > 0) { 1649 #ifdef CONFIG_PPP_MULTILINK 1650 /* XXX do channel-level decompression here */ 1651 if (PPP_PROTO(skb) == PPP_MP) 1652 ppp_receive_mp_frame(ppp, skb, pch); 1653 else 1654 #endif /* CONFIG_PPP_MULTILINK */ 1655 ppp_receive_nonmp_frame(ppp, skb); 1656 } else { 1657 kfree_skb(skb); 1658 ppp_receive_error(ppp); 1659 } 1660 } 1661 1662 static void 1663 ppp_receive_error(struct ppp *ppp) 1664 { 1665 ++ppp->dev->stats.rx_errors; 1666 if (ppp->vj) 1667 slhc_toss(ppp->vj); 1668 } 1669 1670 static void 1671 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) 1672 { 1673 struct sk_buff *ns; 1674 int proto, len, npi; 1675 1676 /* 1677 * Decompress the frame, if compressed. 1678 * Note that some decompressors need to see uncompressed frames 1679 * that come in as well as compressed frames. 1680 */ 1681 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) && 1682 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0) 1683 skb = ppp_decompress_frame(ppp, skb); 1684 1685 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR) 1686 goto err; 1687 1688 proto = PPP_PROTO(skb); 1689 switch (proto) { 1690 case PPP_VJC_COMP: 1691 /* decompress VJ compressed packets */ 1692 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 1693 goto err; 1694 1695 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) { 1696 /* copy to a new sk_buff with more tailroom */ 1697 ns = dev_alloc_skb(skb->len + 128); 1698 if (!ns) { 1699 netdev_err(ppp->dev, "PPP: no memory " 1700 "(VJ decomp)\n"); 1701 goto err; 1702 } 1703 skb_reserve(ns, 2); 1704 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len); 1705 kfree_skb(skb); 1706 skb = ns; 1707 } 1708 else 1709 skb->ip_summed = CHECKSUM_NONE; 1710 1711 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2); 1712 if (len <= 0) { 1713 netdev_printk(KERN_DEBUG, ppp->dev, 1714 "PPP: VJ decompression error\n"); 1715 goto err; 1716 } 1717 len += 2; 1718 if (len > skb->len) 1719 skb_put(skb, len - skb->len); 1720 else if (len < skb->len) 1721 skb_trim(skb, len); 1722 proto = PPP_IP; 1723 break; 1724 1725 case PPP_VJC_UNCOMP: 1726 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 1727 goto err; 1728 1729 /* Until we fix the decompressor need to make sure 1730 * data portion is linear. 1731 */ 1732 if (!pskb_may_pull(skb, skb->len)) 1733 goto err; 1734 1735 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) { 1736 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n"); 1737 goto err; 1738 } 1739 proto = PPP_IP; 1740 break; 1741 1742 case PPP_CCP: 1743 ppp_ccp_peek(ppp, skb, 1); 1744 break; 1745 } 1746 1747 ++ppp->dev->stats.rx_packets; 1748 ppp->dev->stats.rx_bytes += skb->len - 2; 1749 1750 npi = proto_to_npindex(proto); 1751 if (npi < 0) { 1752 /* control or unknown frame - pass it to pppd */ 1753 skb_queue_tail(&ppp->file.rq, skb); 1754 /* limit queue length by dropping old frames */ 1755 while (ppp->file.rq.qlen > PPP_MAX_RQLEN && 1756 (skb = skb_dequeue(&ppp->file.rq))) 1757 kfree_skb(skb); 1758 /* wake up any process polling or blocking on read */ 1759 wake_up_interruptible(&ppp->file.rwait); 1760 1761 } else { 1762 /* network protocol frame - give it to the kernel */ 1763 1764 #ifdef CONFIG_PPP_FILTER 1765 /* check if the packet passes the pass and active filters */ 1766 /* the filter instructions are constructed assuming 1767 a four-byte PPP header on each packet */ 1768 if (ppp->pass_filter || ppp->active_filter) { 1769 if (skb_cloned(skb) && 1770 pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) 1771 goto err; 1772 1773 *skb_push(skb, 2) = 0; 1774 if (ppp->pass_filter && 1775 sk_run_filter(skb, ppp->pass_filter) == 0) { 1776 if (ppp->debug & 1) 1777 netdev_printk(KERN_DEBUG, ppp->dev, 1778 "PPP: inbound frame " 1779 "not passed\n"); 1780 kfree_skb(skb); 1781 return; 1782 } 1783 if (!(ppp->active_filter && 1784 sk_run_filter(skb, ppp->active_filter) == 0)) 1785 ppp->last_recv = jiffies; 1786 __skb_pull(skb, 2); 1787 } else 1788 #endif /* CONFIG_PPP_FILTER */ 1789 ppp->last_recv = jiffies; 1790 1791 if ((ppp->dev->flags & IFF_UP) == 0 || 1792 ppp->npmode[npi] != NPMODE_PASS) { 1793 kfree_skb(skb); 1794 } else { 1795 /* chop off protocol */ 1796 skb_pull_rcsum(skb, 2); 1797 skb->dev = ppp->dev; 1798 skb->protocol = htons(npindex_to_ethertype[npi]); 1799 skb_reset_mac_header(skb); 1800 netif_rx(skb); 1801 } 1802 } 1803 return; 1804 1805 err: 1806 kfree_skb(skb); 1807 ppp_receive_error(ppp); 1808 } 1809 1810 static struct sk_buff * 1811 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb) 1812 { 1813 int proto = PPP_PROTO(skb); 1814 struct sk_buff *ns; 1815 int len; 1816 1817 /* Until we fix all the decompressor's need to make sure 1818 * data portion is linear. 1819 */ 1820 if (!pskb_may_pull(skb, skb->len)) 1821 goto err; 1822 1823 if (proto == PPP_COMP) { 1824 int obuff_size; 1825 1826 switch(ppp->rcomp->compress_proto) { 1827 case CI_MPPE: 1828 obuff_size = ppp->mru + PPP_HDRLEN + 1; 1829 break; 1830 default: 1831 obuff_size = ppp->mru + PPP_HDRLEN; 1832 break; 1833 } 1834 1835 ns = dev_alloc_skb(obuff_size); 1836 if (!ns) { 1837 netdev_err(ppp->dev, "ppp_decompress_frame: " 1838 "no memory\n"); 1839 goto err; 1840 } 1841 /* the decompressor still expects the A/C bytes in the hdr */ 1842 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2, 1843 skb->len + 2, ns->data, obuff_size); 1844 if (len < 0) { 1845 /* Pass the compressed frame to pppd as an 1846 error indication. */ 1847 if (len == DECOMP_FATALERROR) 1848 ppp->rstate |= SC_DC_FERROR; 1849 kfree_skb(ns); 1850 goto err; 1851 } 1852 1853 kfree_skb(skb); 1854 skb = ns; 1855 skb_put(skb, len); 1856 skb_pull(skb, 2); /* pull off the A/C bytes */ 1857 1858 } else { 1859 /* Uncompressed frame - pass to decompressor so it 1860 can update its dictionary if necessary. */ 1861 if (ppp->rcomp->incomp) 1862 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2, 1863 skb->len + 2); 1864 } 1865 1866 return skb; 1867 1868 err: 1869 ppp->rstate |= SC_DC_ERROR; 1870 ppp_receive_error(ppp); 1871 return skb; 1872 } 1873 1874 #ifdef CONFIG_PPP_MULTILINK 1875 /* 1876 * Receive a multilink frame. 1877 * We put it on the reconstruction queue and then pull off 1878 * as many completed frames as we can. 1879 */ 1880 static void 1881 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1882 { 1883 u32 mask, seq; 1884 struct channel *ch; 1885 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1886 1887 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0) 1888 goto err; /* no good, throw it away */ 1889 1890 /* Decode sequence number and begin/end bits */ 1891 if (ppp->flags & SC_MP_SHORTSEQ) { 1892 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3]; 1893 mask = 0xfff; 1894 } else { 1895 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5]; 1896 mask = 0xffffff; 1897 } 1898 PPP_MP_CB(skb)->BEbits = skb->data[2]; 1899 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */ 1900 1901 /* 1902 * Do protocol ID decompression on the first fragment of each packet. 1903 */ 1904 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1)) 1905 *skb_push(skb, 1) = 0; 1906 1907 /* 1908 * Expand sequence number to 32 bits, making it as close 1909 * as possible to ppp->minseq. 1910 */ 1911 seq |= ppp->minseq & ~mask; 1912 if ((int)(ppp->minseq - seq) > (int)(mask >> 1)) 1913 seq += mask + 1; 1914 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1)) 1915 seq -= mask + 1; /* should never happen */ 1916 PPP_MP_CB(skb)->sequence = seq; 1917 pch->lastseq = seq; 1918 1919 /* 1920 * If this packet comes before the next one we were expecting, 1921 * drop it. 1922 */ 1923 if (seq_before(seq, ppp->nextseq)) { 1924 kfree_skb(skb); 1925 ++ppp->dev->stats.rx_dropped; 1926 ppp_receive_error(ppp); 1927 return; 1928 } 1929 1930 /* 1931 * Reevaluate minseq, the minimum over all channels of the 1932 * last sequence number received on each channel. Because of 1933 * the increasing sequence number rule, we know that any fragment 1934 * before `minseq' which hasn't arrived is never going to arrive. 1935 * The list of channels can't change because we have the receive 1936 * side of the ppp unit locked. 1937 */ 1938 list_for_each_entry(ch, &ppp->channels, clist) { 1939 if (seq_before(ch->lastseq, seq)) 1940 seq = ch->lastseq; 1941 } 1942 if (seq_before(ppp->minseq, seq)) 1943 ppp->minseq = seq; 1944 1945 /* Put the fragment on the reconstruction queue */ 1946 ppp_mp_insert(ppp, skb); 1947 1948 /* If the queue is getting long, don't wait any longer for packets 1949 before the start of the queue. */ 1950 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) { 1951 struct sk_buff *mskb = skb_peek(&ppp->mrq); 1952 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence)) 1953 ppp->minseq = PPP_MP_CB(mskb)->sequence; 1954 } 1955 1956 /* Pull completed packets off the queue and receive them. */ 1957 while ((skb = ppp_mp_reconstruct(ppp))) { 1958 if (pskb_may_pull(skb, 2)) 1959 ppp_receive_nonmp_frame(ppp, skb); 1960 else { 1961 ++ppp->dev->stats.rx_length_errors; 1962 kfree_skb(skb); 1963 ppp_receive_error(ppp); 1964 } 1965 } 1966 1967 return; 1968 1969 err: 1970 kfree_skb(skb); 1971 ppp_receive_error(ppp); 1972 } 1973 1974 /* 1975 * Insert a fragment on the MP reconstruction queue. 1976 * The queue is ordered by increasing sequence number. 1977 */ 1978 static void 1979 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb) 1980 { 1981 struct sk_buff *p; 1982 struct sk_buff_head *list = &ppp->mrq; 1983 u32 seq = PPP_MP_CB(skb)->sequence; 1984 1985 /* N.B. we don't need to lock the list lock because we have the 1986 ppp unit receive-side lock. */ 1987 skb_queue_walk(list, p) { 1988 if (seq_before(seq, PPP_MP_CB(p)->sequence)) 1989 break; 1990 } 1991 __skb_queue_before(list, p, skb); 1992 } 1993 1994 /* 1995 * Reconstruct a packet from the MP fragment queue. 1996 * We go through increasing sequence numbers until we find a 1997 * complete packet, or we get to the sequence number for a fragment 1998 * which hasn't arrived but might still do so. 1999 */ 2000 static struct sk_buff * 2001 ppp_mp_reconstruct(struct ppp *ppp) 2002 { 2003 u32 seq = ppp->nextseq; 2004 u32 minseq = ppp->minseq; 2005 struct sk_buff_head *list = &ppp->mrq; 2006 struct sk_buff *p, *tmp; 2007 struct sk_buff *head, *tail; 2008 struct sk_buff *skb = NULL; 2009 int lost = 0, len = 0; 2010 2011 if (ppp->mrru == 0) /* do nothing until mrru is set */ 2012 return NULL; 2013 head = list->next; 2014 tail = NULL; 2015 skb_queue_walk_safe(list, p, tmp) { 2016 again: 2017 if (seq_before(PPP_MP_CB(p)->sequence, seq)) { 2018 /* this can't happen, anyway ignore the skb */ 2019 netdev_err(ppp->dev, "ppp_mp_reconstruct bad " 2020 "seq %u < %u\n", 2021 PPP_MP_CB(p)->sequence, seq); 2022 __skb_unlink(p, list); 2023 kfree_skb(p); 2024 continue; 2025 } 2026 if (PPP_MP_CB(p)->sequence != seq) { 2027 /* Fragment `seq' is missing. If it is after 2028 minseq, it might arrive later, so stop here. */ 2029 if (seq_after(seq, minseq)) 2030 break; 2031 /* Fragment `seq' is lost, keep going. */ 2032 lost = 1; 2033 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)? 2034 minseq + 1: PPP_MP_CB(p)->sequence; 2035 goto again; 2036 } 2037 2038 /* 2039 * At this point we know that all the fragments from 2040 * ppp->nextseq to seq are either present or lost. 2041 * Also, there are no complete packets in the queue 2042 * that have no missing fragments and end before this 2043 * fragment. 2044 */ 2045 2046 /* B bit set indicates this fragment starts a packet */ 2047 if (PPP_MP_CB(p)->BEbits & B) { 2048 head = p; 2049 lost = 0; 2050 len = 0; 2051 } 2052 2053 len += p->len; 2054 2055 /* Got a complete packet yet? */ 2056 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) && 2057 (PPP_MP_CB(head)->BEbits & B)) { 2058 if (len > ppp->mrru + 2) { 2059 ++ppp->dev->stats.rx_length_errors; 2060 netdev_printk(KERN_DEBUG, ppp->dev, 2061 "PPP: reconstructed packet" 2062 " is too long (%d)\n", len); 2063 } else { 2064 tail = p; 2065 break; 2066 } 2067 ppp->nextseq = seq + 1; 2068 } 2069 2070 /* 2071 * If this is the ending fragment of a packet, 2072 * and we haven't found a complete valid packet yet, 2073 * we can discard up to and including this fragment. 2074 */ 2075 if (PPP_MP_CB(p)->BEbits & E) { 2076 struct sk_buff *tmp2; 2077 2078 skb_queue_reverse_walk_from_safe(list, p, tmp2) { 2079 __skb_unlink(p, list); 2080 kfree_skb(p); 2081 } 2082 head = skb_peek(list); 2083 if (!head) 2084 break; 2085 } 2086 ++seq; 2087 } 2088 2089 /* If we have a complete packet, copy it all into one skb. */ 2090 if (tail != NULL) { 2091 /* If we have discarded any fragments, 2092 signal a receive error. */ 2093 if (PPP_MP_CB(head)->sequence != ppp->nextseq) { 2094 if (ppp->debug & 1) 2095 netdev_printk(KERN_DEBUG, ppp->dev, 2096 " missed pkts %u..%u\n", 2097 ppp->nextseq, 2098 PPP_MP_CB(head)->sequence-1); 2099 ++ppp->dev->stats.rx_dropped; 2100 ppp_receive_error(ppp); 2101 } 2102 2103 skb = head; 2104 if (head != tail) { 2105 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list; 2106 p = skb_queue_next(list, head); 2107 __skb_unlink(skb, list); 2108 skb_queue_walk_from_safe(list, p, tmp) { 2109 __skb_unlink(p, list); 2110 *fragpp = p; 2111 p->next = NULL; 2112 fragpp = &p->next; 2113 2114 skb->len += p->len; 2115 skb->data_len += p->len; 2116 skb->truesize += p->len; 2117 2118 if (p == tail) 2119 break; 2120 } 2121 } else { 2122 __skb_unlink(skb, list); 2123 } 2124 2125 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1; 2126 } 2127 2128 return skb; 2129 } 2130 #endif /* CONFIG_PPP_MULTILINK */ 2131 2132 /* 2133 * Channel interface. 2134 */ 2135 2136 /* Create a new, unattached ppp channel. */ 2137 int ppp_register_channel(struct ppp_channel *chan) 2138 { 2139 return ppp_register_net_channel(current->nsproxy->net_ns, chan); 2140 } 2141 2142 /* Create a new, unattached ppp channel for specified net. */ 2143 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan) 2144 { 2145 struct channel *pch; 2146 struct ppp_net *pn; 2147 2148 pch = kzalloc(sizeof(struct channel), GFP_KERNEL); 2149 if (!pch) 2150 return -ENOMEM; 2151 2152 pn = ppp_pernet(net); 2153 2154 pch->ppp = NULL; 2155 pch->chan = chan; 2156 pch->chan_net = net; 2157 chan->ppp = pch; 2158 init_ppp_file(&pch->file, CHANNEL); 2159 pch->file.hdrlen = chan->hdrlen; 2160 #ifdef CONFIG_PPP_MULTILINK 2161 pch->lastseq = -1; 2162 #endif /* CONFIG_PPP_MULTILINK */ 2163 init_rwsem(&pch->chan_sem); 2164 spin_lock_init(&pch->downl); 2165 rwlock_init(&pch->upl); 2166 2167 spin_lock_bh(&pn->all_channels_lock); 2168 pch->file.index = ++pn->last_channel_index; 2169 list_add(&pch->list, &pn->new_channels); 2170 atomic_inc(&channel_count); 2171 spin_unlock_bh(&pn->all_channels_lock); 2172 2173 return 0; 2174 } 2175 2176 /* 2177 * Return the index of a channel. 2178 */ 2179 int ppp_channel_index(struct ppp_channel *chan) 2180 { 2181 struct channel *pch = chan->ppp; 2182 2183 if (pch) 2184 return pch->file.index; 2185 return -1; 2186 } 2187 2188 /* 2189 * Return the PPP unit number to which a channel is connected. 2190 */ 2191 int ppp_unit_number(struct ppp_channel *chan) 2192 { 2193 struct channel *pch = chan->ppp; 2194 int unit = -1; 2195 2196 if (pch) { 2197 read_lock_bh(&pch->upl); 2198 if (pch->ppp) 2199 unit = pch->ppp->file.index; 2200 read_unlock_bh(&pch->upl); 2201 } 2202 return unit; 2203 } 2204 2205 /* 2206 * Return the PPP device interface name of a channel. 2207 */ 2208 char *ppp_dev_name(struct ppp_channel *chan) 2209 { 2210 struct channel *pch = chan->ppp; 2211 char *name = NULL; 2212 2213 if (pch) { 2214 read_lock_bh(&pch->upl); 2215 if (pch->ppp && pch->ppp->dev) 2216 name = pch->ppp->dev->name; 2217 read_unlock_bh(&pch->upl); 2218 } 2219 return name; 2220 } 2221 2222 2223 /* 2224 * Disconnect a channel from the generic layer. 2225 * This must be called in process context. 2226 */ 2227 void 2228 ppp_unregister_channel(struct ppp_channel *chan) 2229 { 2230 struct channel *pch = chan->ppp; 2231 struct ppp_net *pn; 2232 2233 if (!pch) 2234 return; /* should never happen */ 2235 2236 chan->ppp = NULL; 2237 2238 /* 2239 * This ensures that we have returned from any calls into the 2240 * the channel's start_xmit or ioctl routine before we proceed. 2241 */ 2242 down_write(&pch->chan_sem); 2243 spin_lock_bh(&pch->downl); 2244 pch->chan = NULL; 2245 spin_unlock_bh(&pch->downl); 2246 up_write(&pch->chan_sem); 2247 ppp_disconnect_channel(pch); 2248 2249 pn = ppp_pernet(pch->chan_net); 2250 spin_lock_bh(&pn->all_channels_lock); 2251 list_del(&pch->list); 2252 spin_unlock_bh(&pn->all_channels_lock); 2253 2254 pch->file.dead = 1; 2255 wake_up_interruptible(&pch->file.rwait); 2256 if (atomic_dec_and_test(&pch->file.refcnt)) 2257 ppp_destroy_channel(pch); 2258 } 2259 2260 /* 2261 * Callback from a channel when it can accept more to transmit. 2262 * This should be called at BH/softirq level, not interrupt level. 2263 */ 2264 void 2265 ppp_output_wakeup(struct ppp_channel *chan) 2266 { 2267 struct channel *pch = chan->ppp; 2268 2269 if (!pch) 2270 return; 2271 ppp_channel_push(pch); 2272 } 2273 2274 /* 2275 * Compression control. 2276 */ 2277 2278 /* Process the PPPIOCSCOMPRESS ioctl. */ 2279 static int 2280 ppp_set_compress(struct ppp *ppp, unsigned long arg) 2281 { 2282 int err; 2283 struct compressor *cp, *ocomp; 2284 struct ppp_option_data data; 2285 void *state, *ostate; 2286 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH]; 2287 2288 err = -EFAULT; 2289 if (copy_from_user(&data, (void __user *) arg, sizeof(data)) || 2290 (data.length <= CCP_MAX_OPTION_LENGTH && 2291 copy_from_user(ccp_option, (void __user *) data.ptr, data.length))) 2292 goto out; 2293 err = -EINVAL; 2294 if (data.length > CCP_MAX_OPTION_LENGTH || 2295 ccp_option[1] < 2 || ccp_option[1] > data.length) 2296 goto out; 2297 2298 cp = try_then_request_module( 2299 find_compressor(ccp_option[0]), 2300 "ppp-compress-%d", ccp_option[0]); 2301 if (!cp) 2302 goto out; 2303 2304 err = -ENOBUFS; 2305 if (data.transmit) { 2306 state = cp->comp_alloc(ccp_option, data.length); 2307 if (state) { 2308 ppp_xmit_lock(ppp); 2309 ppp->xstate &= ~SC_COMP_RUN; 2310 ocomp = ppp->xcomp; 2311 ostate = ppp->xc_state; 2312 ppp->xcomp = cp; 2313 ppp->xc_state = state; 2314 ppp_xmit_unlock(ppp); 2315 if (ostate) { 2316 ocomp->comp_free(ostate); 2317 module_put(ocomp->owner); 2318 } 2319 err = 0; 2320 } else 2321 module_put(cp->owner); 2322 2323 } else { 2324 state = cp->decomp_alloc(ccp_option, data.length); 2325 if (state) { 2326 ppp_recv_lock(ppp); 2327 ppp->rstate &= ~SC_DECOMP_RUN; 2328 ocomp = ppp->rcomp; 2329 ostate = ppp->rc_state; 2330 ppp->rcomp = cp; 2331 ppp->rc_state = state; 2332 ppp_recv_unlock(ppp); 2333 if (ostate) { 2334 ocomp->decomp_free(ostate); 2335 module_put(ocomp->owner); 2336 } 2337 err = 0; 2338 } else 2339 module_put(cp->owner); 2340 } 2341 2342 out: 2343 return err; 2344 } 2345 2346 /* 2347 * Look at a CCP packet and update our state accordingly. 2348 * We assume the caller has the xmit or recv path locked. 2349 */ 2350 static void 2351 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound) 2352 { 2353 unsigned char *dp; 2354 int len; 2355 2356 if (!pskb_may_pull(skb, CCP_HDRLEN + 2)) 2357 return; /* no header */ 2358 dp = skb->data + 2; 2359 2360 switch (CCP_CODE(dp)) { 2361 case CCP_CONFREQ: 2362 2363 /* A ConfReq starts negotiation of compression 2364 * in one direction of transmission, 2365 * and hence brings it down...but which way? 2366 * 2367 * Remember: 2368 * A ConfReq indicates what the sender would like to receive 2369 */ 2370 if(inbound) 2371 /* He is proposing what I should send */ 2372 ppp->xstate &= ~SC_COMP_RUN; 2373 else 2374 /* I am proposing to what he should send */ 2375 ppp->rstate &= ~SC_DECOMP_RUN; 2376 2377 break; 2378 2379 case CCP_TERMREQ: 2380 case CCP_TERMACK: 2381 /* 2382 * CCP is going down, both directions of transmission 2383 */ 2384 ppp->rstate &= ~SC_DECOMP_RUN; 2385 ppp->xstate &= ~SC_COMP_RUN; 2386 break; 2387 2388 case CCP_CONFACK: 2389 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN) 2390 break; 2391 len = CCP_LENGTH(dp); 2392 if (!pskb_may_pull(skb, len + 2)) 2393 return; /* too short */ 2394 dp += CCP_HDRLEN; 2395 len -= CCP_HDRLEN; 2396 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp)) 2397 break; 2398 if (inbound) { 2399 /* we will start receiving compressed packets */ 2400 if (!ppp->rc_state) 2401 break; 2402 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len, 2403 ppp->file.index, 0, ppp->mru, ppp->debug)) { 2404 ppp->rstate |= SC_DECOMP_RUN; 2405 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR); 2406 } 2407 } else { 2408 /* we will soon start sending compressed packets */ 2409 if (!ppp->xc_state) 2410 break; 2411 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len, 2412 ppp->file.index, 0, ppp->debug)) 2413 ppp->xstate |= SC_COMP_RUN; 2414 } 2415 break; 2416 2417 case CCP_RESETACK: 2418 /* reset the [de]compressor */ 2419 if ((ppp->flags & SC_CCP_UP) == 0) 2420 break; 2421 if (inbound) { 2422 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) { 2423 ppp->rcomp->decomp_reset(ppp->rc_state); 2424 ppp->rstate &= ~SC_DC_ERROR; 2425 } 2426 } else { 2427 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN)) 2428 ppp->xcomp->comp_reset(ppp->xc_state); 2429 } 2430 break; 2431 } 2432 } 2433 2434 /* Free up compression resources. */ 2435 static void 2436 ppp_ccp_closed(struct ppp *ppp) 2437 { 2438 void *xstate, *rstate; 2439 struct compressor *xcomp, *rcomp; 2440 2441 ppp_lock(ppp); 2442 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP); 2443 ppp->xstate = 0; 2444 xcomp = ppp->xcomp; 2445 xstate = ppp->xc_state; 2446 ppp->xc_state = NULL; 2447 ppp->rstate = 0; 2448 rcomp = ppp->rcomp; 2449 rstate = ppp->rc_state; 2450 ppp->rc_state = NULL; 2451 ppp_unlock(ppp); 2452 2453 if (xstate) { 2454 xcomp->comp_free(xstate); 2455 module_put(xcomp->owner); 2456 } 2457 if (rstate) { 2458 rcomp->decomp_free(rstate); 2459 module_put(rcomp->owner); 2460 } 2461 } 2462 2463 /* List of compressors. */ 2464 static LIST_HEAD(compressor_list); 2465 static DEFINE_SPINLOCK(compressor_list_lock); 2466 2467 struct compressor_entry { 2468 struct list_head list; 2469 struct compressor *comp; 2470 }; 2471 2472 static struct compressor_entry * 2473 find_comp_entry(int proto) 2474 { 2475 struct compressor_entry *ce; 2476 2477 list_for_each_entry(ce, &compressor_list, list) { 2478 if (ce->comp->compress_proto == proto) 2479 return ce; 2480 } 2481 return NULL; 2482 } 2483 2484 /* Register a compressor */ 2485 int 2486 ppp_register_compressor(struct compressor *cp) 2487 { 2488 struct compressor_entry *ce; 2489 int ret; 2490 spin_lock(&compressor_list_lock); 2491 ret = -EEXIST; 2492 if (find_comp_entry(cp->compress_proto)) 2493 goto out; 2494 ret = -ENOMEM; 2495 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC); 2496 if (!ce) 2497 goto out; 2498 ret = 0; 2499 ce->comp = cp; 2500 list_add(&ce->list, &compressor_list); 2501 out: 2502 spin_unlock(&compressor_list_lock); 2503 return ret; 2504 } 2505 2506 /* Unregister a compressor */ 2507 void 2508 ppp_unregister_compressor(struct compressor *cp) 2509 { 2510 struct compressor_entry *ce; 2511 2512 spin_lock(&compressor_list_lock); 2513 ce = find_comp_entry(cp->compress_proto); 2514 if (ce && ce->comp == cp) { 2515 list_del(&ce->list); 2516 kfree(ce); 2517 } 2518 spin_unlock(&compressor_list_lock); 2519 } 2520 2521 /* Find a compressor. */ 2522 static struct compressor * 2523 find_compressor(int type) 2524 { 2525 struct compressor_entry *ce; 2526 struct compressor *cp = NULL; 2527 2528 spin_lock(&compressor_list_lock); 2529 ce = find_comp_entry(type); 2530 if (ce) { 2531 cp = ce->comp; 2532 if (!try_module_get(cp->owner)) 2533 cp = NULL; 2534 } 2535 spin_unlock(&compressor_list_lock); 2536 return cp; 2537 } 2538 2539 /* 2540 * Miscelleneous stuff. 2541 */ 2542 2543 static void 2544 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st) 2545 { 2546 struct slcompress *vj = ppp->vj; 2547 2548 memset(st, 0, sizeof(*st)); 2549 st->p.ppp_ipackets = ppp->dev->stats.rx_packets; 2550 st->p.ppp_ierrors = ppp->dev->stats.rx_errors; 2551 st->p.ppp_ibytes = ppp->dev->stats.rx_bytes; 2552 st->p.ppp_opackets = ppp->dev->stats.tx_packets; 2553 st->p.ppp_oerrors = ppp->dev->stats.tx_errors; 2554 st->p.ppp_obytes = ppp->dev->stats.tx_bytes; 2555 if (!vj) 2556 return; 2557 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed; 2558 st->vj.vjs_compressed = vj->sls_o_compressed; 2559 st->vj.vjs_searches = vj->sls_o_searches; 2560 st->vj.vjs_misses = vj->sls_o_misses; 2561 st->vj.vjs_errorin = vj->sls_i_error; 2562 st->vj.vjs_tossed = vj->sls_i_tossed; 2563 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed; 2564 st->vj.vjs_compressedin = vj->sls_i_compressed; 2565 } 2566 2567 /* 2568 * Stuff for handling the lists of ppp units and channels 2569 * and for initialization. 2570 */ 2571 2572 /* 2573 * Create a new ppp interface unit. Fails if it can't allocate memory 2574 * or if there is already a unit with the requested number. 2575 * unit == -1 means allocate a new number. 2576 */ 2577 static struct ppp * 2578 ppp_create_interface(struct net *net, int unit, int *retp) 2579 { 2580 struct ppp *ppp; 2581 struct ppp_net *pn; 2582 struct net_device *dev = NULL; 2583 int ret = -ENOMEM; 2584 int i; 2585 2586 dev = alloc_netdev(sizeof(struct ppp), "", ppp_setup); 2587 if (!dev) 2588 goto out1; 2589 2590 pn = ppp_pernet(net); 2591 2592 ppp = netdev_priv(dev); 2593 ppp->dev = dev; 2594 ppp->mru = PPP_MRU; 2595 init_ppp_file(&ppp->file, INTERFACE); 2596 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */ 2597 for (i = 0; i < NUM_NP; ++i) 2598 ppp->npmode[i] = NPMODE_PASS; 2599 INIT_LIST_HEAD(&ppp->channels); 2600 spin_lock_init(&ppp->rlock); 2601 spin_lock_init(&ppp->wlock); 2602 #ifdef CONFIG_PPP_MULTILINK 2603 ppp->minseq = -1; 2604 skb_queue_head_init(&ppp->mrq); 2605 #endif /* CONFIG_PPP_MULTILINK */ 2606 2607 /* 2608 * drum roll: don't forget to set 2609 * the net device is belong to 2610 */ 2611 dev_net_set(dev, net); 2612 2613 mutex_lock(&pn->all_ppp_mutex); 2614 2615 if (unit < 0) { 2616 unit = unit_get(&pn->units_idr, ppp); 2617 if (unit < 0) { 2618 ret = unit; 2619 goto out2; 2620 } 2621 } else { 2622 ret = -EEXIST; 2623 if (unit_find(&pn->units_idr, unit)) 2624 goto out2; /* unit already exists */ 2625 /* 2626 * if caller need a specified unit number 2627 * lets try to satisfy him, otherwise -- 2628 * he should better ask us for new unit number 2629 * 2630 * NOTE: yes I know that returning EEXIST it's not 2631 * fair but at least pppd will ask us to allocate 2632 * new unit in this case so user is happy :) 2633 */ 2634 unit = unit_set(&pn->units_idr, ppp, unit); 2635 if (unit < 0) 2636 goto out2; 2637 } 2638 2639 /* Initialize the new ppp unit */ 2640 ppp->file.index = unit; 2641 sprintf(dev->name, "ppp%d", unit); 2642 2643 ret = register_netdev(dev); 2644 if (ret != 0) { 2645 unit_put(&pn->units_idr, unit); 2646 netdev_err(ppp->dev, "PPP: couldn't register device %s (%d)\n", 2647 dev->name, ret); 2648 goto out2; 2649 } 2650 2651 ppp->ppp_net = net; 2652 2653 atomic_inc(&ppp_unit_count); 2654 mutex_unlock(&pn->all_ppp_mutex); 2655 2656 *retp = 0; 2657 return ppp; 2658 2659 out2: 2660 mutex_unlock(&pn->all_ppp_mutex); 2661 free_netdev(dev); 2662 out1: 2663 *retp = ret; 2664 return NULL; 2665 } 2666 2667 /* 2668 * Initialize a ppp_file structure. 2669 */ 2670 static void 2671 init_ppp_file(struct ppp_file *pf, int kind) 2672 { 2673 pf->kind = kind; 2674 skb_queue_head_init(&pf->xq); 2675 skb_queue_head_init(&pf->rq); 2676 atomic_set(&pf->refcnt, 1); 2677 init_waitqueue_head(&pf->rwait); 2678 } 2679 2680 /* 2681 * Take down a ppp interface unit - called when the owning file 2682 * (the one that created the unit) is closed or detached. 2683 */ 2684 static void ppp_shutdown_interface(struct ppp *ppp) 2685 { 2686 struct ppp_net *pn; 2687 2688 pn = ppp_pernet(ppp->ppp_net); 2689 mutex_lock(&pn->all_ppp_mutex); 2690 2691 /* This will call dev_close() for us. */ 2692 ppp_lock(ppp); 2693 if (!ppp->closing) { 2694 ppp->closing = 1; 2695 ppp_unlock(ppp); 2696 unregister_netdev(ppp->dev); 2697 unit_put(&pn->units_idr, ppp->file.index); 2698 } else 2699 ppp_unlock(ppp); 2700 2701 ppp->file.dead = 1; 2702 ppp->owner = NULL; 2703 wake_up_interruptible(&ppp->file.rwait); 2704 2705 mutex_unlock(&pn->all_ppp_mutex); 2706 } 2707 2708 /* 2709 * Free the memory used by a ppp unit. This is only called once 2710 * there are no channels connected to the unit and no file structs 2711 * that reference the unit. 2712 */ 2713 static void ppp_destroy_interface(struct ppp *ppp) 2714 { 2715 atomic_dec(&ppp_unit_count); 2716 2717 if (!ppp->file.dead || ppp->n_channels) { 2718 /* "can't happen" */ 2719 netdev_err(ppp->dev, "ppp: destroying ppp struct %p " 2720 "but dead=%d n_channels=%d !\n", 2721 ppp, ppp->file.dead, ppp->n_channels); 2722 return; 2723 } 2724 2725 ppp_ccp_closed(ppp); 2726 if (ppp->vj) { 2727 slhc_free(ppp->vj); 2728 ppp->vj = NULL; 2729 } 2730 skb_queue_purge(&ppp->file.xq); 2731 skb_queue_purge(&ppp->file.rq); 2732 #ifdef CONFIG_PPP_MULTILINK 2733 skb_queue_purge(&ppp->mrq); 2734 #endif /* CONFIG_PPP_MULTILINK */ 2735 #ifdef CONFIG_PPP_FILTER 2736 kfree(ppp->pass_filter); 2737 ppp->pass_filter = NULL; 2738 kfree(ppp->active_filter); 2739 ppp->active_filter = NULL; 2740 #endif /* CONFIG_PPP_FILTER */ 2741 2742 kfree_skb(ppp->xmit_pending); 2743 2744 free_netdev(ppp->dev); 2745 } 2746 2747 /* 2748 * Locate an existing ppp unit. 2749 * The caller should have locked the all_ppp_mutex. 2750 */ 2751 static struct ppp * 2752 ppp_find_unit(struct ppp_net *pn, int unit) 2753 { 2754 return unit_find(&pn->units_idr, unit); 2755 } 2756 2757 /* 2758 * Locate an existing ppp channel. 2759 * The caller should have locked the all_channels_lock. 2760 * First we look in the new_channels list, then in the 2761 * all_channels list. If found in the new_channels list, 2762 * we move it to the all_channels list. This is for speed 2763 * when we have a lot of channels in use. 2764 */ 2765 static struct channel * 2766 ppp_find_channel(struct ppp_net *pn, int unit) 2767 { 2768 struct channel *pch; 2769 2770 list_for_each_entry(pch, &pn->new_channels, list) { 2771 if (pch->file.index == unit) { 2772 list_move(&pch->list, &pn->all_channels); 2773 return pch; 2774 } 2775 } 2776 2777 list_for_each_entry(pch, &pn->all_channels, list) { 2778 if (pch->file.index == unit) 2779 return pch; 2780 } 2781 2782 return NULL; 2783 } 2784 2785 /* 2786 * Connect a PPP channel to a PPP interface unit. 2787 */ 2788 static int 2789 ppp_connect_channel(struct channel *pch, int unit) 2790 { 2791 struct ppp *ppp; 2792 struct ppp_net *pn; 2793 int ret = -ENXIO; 2794 int hdrlen; 2795 2796 pn = ppp_pernet(pch->chan_net); 2797 2798 mutex_lock(&pn->all_ppp_mutex); 2799 ppp = ppp_find_unit(pn, unit); 2800 if (!ppp) 2801 goto out; 2802 write_lock_bh(&pch->upl); 2803 ret = -EINVAL; 2804 if (pch->ppp) 2805 goto outl; 2806 2807 ppp_lock(ppp); 2808 if (pch->file.hdrlen > ppp->file.hdrlen) 2809 ppp->file.hdrlen = pch->file.hdrlen; 2810 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */ 2811 if (hdrlen > ppp->dev->hard_header_len) 2812 ppp->dev->hard_header_len = hdrlen; 2813 list_add_tail(&pch->clist, &ppp->channels); 2814 ++ppp->n_channels; 2815 pch->ppp = ppp; 2816 atomic_inc(&ppp->file.refcnt); 2817 ppp_unlock(ppp); 2818 ret = 0; 2819 2820 outl: 2821 write_unlock_bh(&pch->upl); 2822 out: 2823 mutex_unlock(&pn->all_ppp_mutex); 2824 return ret; 2825 } 2826 2827 /* 2828 * Disconnect a channel from its ppp unit. 2829 */ 2830 static int 2831 ppp_disconnect_channel(struct channel *pch) 2832 { 2833 struct ppp *ppp; 2834 int err = -EINVAL; 2835 2836 write_lock_bh(&pch->upl); 2837 ppp = pch->ppp; 2838 pch->ppp = NULL; 2839 write_unlock_bh(&pch->upl); 2840 if (ppp) { 2841 /* remove it from the ppp unit's list */ 2842 ppp_lock(ppp); 2843 list_del(&pch->clist); 2844 if (--ppp->n_channels == 0) 2845 wake_up_interruptible(&ppp->file.rwait); 2846 ppp_unlock(ppp); 2847 if (atomic_dec_and_test(&ppp->file.refcnt)) 2848 ppp_destroy_interface(ppp); 2849 err = 0; 2850 } 2851 return err; 2852 } 2853 2854 /* 2855 * Free up the resources used by a ppp channel. 2856 */ 2857 static void ppp_destroy_channel(struct channel *pch) 2858 { 2859 atomic_dec(&channel_count); 2860 2861 if (!pch->file.dead) { 2862 /* "can't happen" */ 2863 pr_err("ppp: destroying undead channel %p !\n", pch); 2864 return; 2865 } 2866 skb_queue_purge(&pch->file.xq); 2867 skb_queue_purge(&pch->file.rq); 2868 kfree(pch); 2869 } 2870 2871 static void __exit ppp_cleanup(void) 2872 { 2873 /* should never happen */ 2874 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count)) 2875 pr_err("PPP: removing module but units remain!\n"); 2876 unregister_chrdev(PPP_MAJOR, "ppp"); 2877 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0)); 2878 class_destroy(ppp_class); 2879 unregister_pernet_device(&ppp_net_ops); 2880 } 2881 2882 /* 2883 * Units handling. Caller must protect concurrent access 2884 * by holding all_ppp_mutex 2885 */ 2886 2887 static int __unit_alloc(struct idr *p, void *ptr, int n) 2888 { 2889 int unit, err; 2890 2891 again: 2892 if (!idr_pre_get(p, GFP_KERNEL)) { 2893 pr_err("PPP: No free memory for idr\n"); 2894 return -ENOMEM; 2895 } 2896 2897 err = idr_get_new_above(p, ptr, n, &unit); 2898 if (err < 0) { 2899 if (err == -EAGAIN) 2900 goto again; 2901 return err; 2902 } 2903 2904 return unit; 2905 } 2906 2907 /* associate pointer with specified number */ 2908 static int unit_set(struct idr *p, void *ptr, int n) 2909 { 2910 int unit; 2911 2912 unit = __unit_alloc(p, ptr, n); 2913 if (unit < 0) 2914 return unit; 2915 else if (unit != n) { 2916 idr_remove(p, unit); 2917 return -EINVAL; 2918 } 2919 2920 return unit; 2921 } 2922 2923 /* get new free unit number and associate pointer with it */ 2924 static int unit_get(struct idr *p, void *ptr) 2925 { 2926 return __unit_alloc(p, ptr, 0); 2927 } 2928 2929 /* put unit number back to a pool */ 2930 static void unit_put(struct idr *p, int n) 2931 { 2932 idr_remove(p, n); 2933 } 2934 2935 /* get pointer associated with the number */ 2936 static void *unit_find(struct idr *p, int n) 2937 { 2938 return idr_find(p, n); 2939 } 2940 2941 /* Module/initialization stuff */ 2942 2943 module_init(ppp_init); 2944 module_exit(ppp_cleanup); 2945 2946 EXPORT_SYMBOL(ppp_register_net_channel); 2947 EXPORT_SYMBOL(ppp_register_channel); 2948 EXPORT_SYMBOL(ppp_unregister_channel); 2949 EXPORT_SYMBOL(ppp_channel_index); 2950 EXPORT_SYMBOL(ppp_unit_number); 2951 EXPORT_SYMBOL(ppp_dev_name); 2952 EXPORT_SYMBOL(ppp_input); 2953 EXPORT_SYMBOL(ppp_input_error); 2954 EXPORT_SYMBOL(ppp_output_wakeup); 2955 EXPORT_SYMBOL(ppp_register_compressor); 2956 EXPORT_SYMBOL(ppp_unregister_compressor); 2957 MODULE_LICENSE("GPL"); 2958 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0); 2959 MODULE_ALIAS("devname:ppp"); 2960