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 <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 int 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 skb_queue_tail(&ppp->file.xq, skb); 972 if (!ppp_xmit_process(ppp)) 973 netif_stop_queue(dev); 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_MRU; 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 int 1052 ppp_xmit_process(struct ppp *ppp) 1053 { 1054 struct sk_buff *skb; 1055 int ret = 0; 1056 1057 ppp_xmit_lock(ppp); 1058 if (!ppp->closing) { 1059 ppp_push(ppp); 1060 while (!ppp->xmit_pending && 1061 (skb = skb_dequeue(&ppp->file.xq))) 1062 ppp_send_frame(ppp, skb); 1063 /* If there's no work left to do, tell the core net 1064 code that we can accept some more. */ 1065 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq)) { 1066 netif_wake_queue(ppp->dev); 1067 ret = 1; 1068 } 1069 } 1070 ppp_xmit_unlock(ppp); 1071 return ret; 1072 } 1073 1074 static inline struct sk_buff * 1075 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) 1076 { 1077 struct sk_buff *new_skb; 1078 int len; 1079 int new_skb_size = ppp->dev->mtu + 1080 ppp->xcomp->comp_extra + ppp->dev->hard_header_len; 1081 int compressor_skb_size = ppp->dev->mtu + 1082 ppp->xcomp->comp_extra + PPP_HDRLEN; 1083 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC); 1084 if (!new_skb) { 1085 if (net_ratelimit()) 1086 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n"); 1087 return NULL; 1088 } 1089 if (ppp->dev->hard_header_len > PPP_HDRLEN) 1090 skb_reserve(new_skb, 1091 ppp->dev->hard_header_len - PPP_HDRLEN); 1092 1093 /* compressor still expects A/C bytes in hdr */ 1094 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, 1095 new_skb->data, skb->len + 2, 1096 compressor_skb_size); 1097 if (len > 0 && (ppp->flags & SC_CCP_UP)) { 1098 kfree_skb(skb); 1099 skb = new_skb; 1100 skb_put(skb, len); 1101 skb_pull(skb, 2); /* pull off A/C bytes */ 1102 } else if (len == 0) { 1103 /* didn't compress, or CCP not up yet */ 1104 kfree_skb(new_skb); 1105 new_skb = skb; 1106 } else { 1107 /* 1108 * (len < 0) 1109 * MPPE requires that we do not send unencrypted 1110 * frames. The compressor will return -1 if we 1111 * should drop the frame. We cannot simply test 1112 * the compress_proto because MPPE and MPPC share 1113 * the same number. 1114 */ 1115 if (net_ratelimit()) 1116 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n"); 1117 kfree_skb(skb); 1118 kfree_skb(new_skb); 1119 new_skb = NULL; 1120 } 1121 return new_skb; 1122 } 1123 1124 /* 1125 * Compress and send a frame. 1126 * The caller should have locked the xmit path, 1127 * and xmit_pending should be 0. 1128 */ 1129 static void 1130 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) 1131 { 1132 int proto = PPP_PROTO(skb); 1133 struct sk_buff *new_skb; 1134 int len; 1135 unsigned char *cp; 1136 1137 if (proto < 0x8000) { 1138 #ifdef CONFIG_PPP_FILTER 1139 /* check if we should pass this packet */ 1140 /* the filter instructions are constructed assuming 1141 a four-byte PPP header on each packet */ 1142 *skb_push(skb, 2) = 1; 1143 if (ppp->pass_filter && 1144 sk_run_filter(skb, ppp->pass_filter) == 0) { 1145 if (ppp->debug & 1) 1146 netdev_printk(KERN_DEBUG, ppp->dev, 1147 "PPP: outbound frame " 1148 "not passed\n"); 1149 kfree_skb(skb); 1150 return; 1151 } 1152 /* if this packet passes the active filter, record the time */ 1153 if (!(ppp->active_filter && 1154 sk_run_filter(skb, ppp->active_filter) == 0)) 1155 ppp->last_xmit = jiffies; 1156 skb_pull(skb, 2); 1157 #else 1158 /* for data packets, record the time */ 1159 ppp->last_xmit = jiffies; 1160 #endif /* CONFIG_PPP_FILTER */ 1161 } 1162 1163 ++ppp->dev->stats.tx_packets; 1164 ppp->dev->stats.tx_bytes += skb->len - 2; 1165 1166 switch (proto) { 1167 case PPP_IP: 1168 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0) 1169 break; 1170 /* try to do VJ TCP header compression */ 1171 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2, 1172 GFP_ATOMIC); 1173 if (!new_skb) { 1174 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n"); 1175 goto drop; 1176 } 1177 skb_reserve(new_skb, ppp->dev->hard_header_len - 2); 1178 cp = skb->data + 2; 1179 len = slhc_compress(ppp->vj, cp, skb->len - 2, 1180 new_skb->data + 2, &cp, 1181 !(ppp->flags & SC_NO_TCP_CCID)); 1182 if (cp == skb->data + 2) { 1183 /* didn't compress */ 1184 kfree_skb(new_skb); 1185 } else { 1186 if (cp[0] & SL_TYPE_COMPRESSED_TCP) { 1187 proto = PPP_VJC_COMP; 1188 cp[0] &= ~SL_TYPE_COMPRESSED_TCP; 1189 } else { 1190 proto = PPP_VJC_UNCOMP; 1191 cp[0] = skb->data[2]; 1192 } 1193 kfree_skb(skb); 1194 skb = new_skb; 1195 cp = skb_put(skb, len + 2); 1196 cp[0] = 0; 1197 cp[1] = proto; 1198 } 1199 break; 1200 1201 case PPP_CCP: 1202 /* peek at outbound CCP frames */ 1203 ppp_ccp_peek(ppp, skb, 0); 1204 break; 1205 } 1206 1207 /* try to do packet compression */ 1208 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state && 1209 proto != PPP_LCP && proto != PPP_CCP) { 1210 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) { 1211 if (net_ratelimit()) 1212 netdev_err(ppp->dev, 1213 "ppp: compression required but " 1214 "down - pkt dropped.\n"); 1215 goto drop; 1216 } 1217 skb = pad_compress_skb(ppp, skb); 1218 if (!skb) 1219 goto drop; 1220 } 1221 1222 /* 1223 * If we are waiting for traffic (demand dialling), 1224 * queue it up for pppd to receive. 1225 */ 1226 if (ppp->flags & SC_LOOP_TRAFFIC) { 1227 if (ppp->file.rq.qlen > PPP_MAX_RQLEN) 1228 goto drop; 1229 skb_queue_tail(&ppp->file.rq, skb); 1230 wake_up_interruptible(&ppp->file.rwait); 1231 return; 1232 } 1233 1234 ppp->xmit_pending = skb; 1235 ppp_push(ppp); 1236 return; 1237 1238 drop: 1239 kfree_skb(skb); 1240 ++ppp->dev->stats.tx_errors; 1241 } 1242 1243 /* 1244 * Try to send the frame in xmit_pending. 1245 * The caller should have the xmit path locked. 1246 */ 1247 static void 1248 ppp_push(struct ppp *ppp) 1249 { 1250 struct list_head *list; 1251 struct channel *pch; 1252 struct sk_buff *skb = ppp->xmit_pending; 1253 1254 if (!skb) 1255 return; 1256 1257 list = &ppp->channels; 1258 if (list_empty(list)) { 1259 /* nowhere to send the packet, just drop it */ 1260 ppp->xmit_pending = NULL; 1261 kfree_skb(skb); 1262 return; 1263 } 1264 1265 if ((ppp->flags & SC_MULTILINK) == 0) { 1266 /* not doing multilink: send it down the first channel */ 1267 list = list->next; 1268 pch = list_entry(list, struct channel, clist); 1269 1270 spin_lock_bh(&pch->downl); 1271 if (pch->chan) { 1272 if (pch->chan->ops->start_xmit(pch->chan, skb)) 1273 ppp->xmit_pending = NULL; 1274 } else { 1275 /* channel got unregistered */ 1276 kfree_skb(skb); 1277 ppp->xmit_pending = NULL; 1278 } 1279 spin_unlock_bh(&pch->downl); 1280 return; 1281 } 1282 1283 #ifdef CONFIG_PPP_MULTILINK 1284 /* Multilink: fragment the packet over as many links 1285 as can take the packet at the moment. */ 1286 if (!ppp_mp_explode(ppp, skb)) 1287 return; 1288 #endif /* CONFIG_PPP_MULTILINK */ 1289 1290 ppp->xmit_pending = NULL; 1291 kfree_skb(skb); 1292 } 1293 1294 #ifdef CONFIG_PPP_MULTILINK 1295 static bool mp_protocol_compress __read_mostly = true; 1296 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR); 1297 MODULE_PARM_DESC(mp_protocol_compress, 1298 "compress protocol id in multilink fragments"); 1299 1300 /* 1301 * Divide a packet to be transmitted into fragments and 1302 * send them out the individual links. 1303 */ 1304 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb) 1305 { 1306 int len, totlen; 1307 int i, bits, hdrlen, mtu; 1308 int flen; 1309 int navail, nfree, nzero; 1310 int nbigger; 1311 int totspeed; 1312 int totfree; 1313 unsigned char *p, *q; 1314 struct list_head *list; 1315 struct channel *pch; 1316 struct sk_buff *frag; 1317 struct ppp_channel *chan; 1318 1319 totspeed = 0; /*total bitrate of the bundle*/ 1320 nfree = 0; /* # channels which have no packet already queued */ 1321 navail = 0; /* total # of usable channels (not deregistered) */ 1322 nzero = 0; /* number of channels with zero speed associated*/ 1323 totfree = 0; /*total # of channels available and 1324 *having no queued packets before 1325 *starting the fragmentation*/ 1326 1327 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1328 i = 0; 1329 list_for_each_entry(pch, &ppp->channels, clist) { 1330 if (pch->chan) { 1331 pch->avail = 1; 1332 navail++; 1333 pch->speed = pch->chan->speed; 1334 } else { 1335 pch->avail = 0; 1336 } 1337 if (pch->avail) { 1338 if (skb_queue_empty(&pch->file.xq) || 1339 !pch->had_frag) { 1340 if (pch->speed == 0) 1341 nzero++; 1342 else 1343 totspeed += pch->speed; 1344 1345 pch->avail = 2; 1346 ++nfree; 1347 ++totfree; 1348 } 1349 if (!pch->had_frag && i < ppp->nxchan) 1350 ppp->nxchan = i; 1351 } 1352 ++i; 1353 } 1354 /* 1355 * Don't start sending this packet unless at least half of 1356 * the channels are free. This gives much better TCP 1357 * performance if we have a lot of channels. 1358 */ 1359 if (nfree == 0 || nfree < navail / 2) 1360 return 0; /* can't take now, leave it in xmit_pending */ 1361 1362 /* Do protocol field compression */ 1363 p = skb->data; 1364 len = skb->len; 1365 if (*p == 0 && mp_protocol_compress) { 1366 ++p; 1367 --len; 1368 } 1369 1370 totlen = len; 1371 nbigger = len % nfree; 1372 1373 /* skip to the channel after the one we last used 1374 and start at that one */ 1375 list = &ppp->channels; 1376 for (i = 0; i < ppp->nxchan; ++i) { 1377 list = list->next; 1378 if (list == &ppp->channels) { 1379 i = 0; 1380 break; 1381 } 1382 } 1383 1384 /* create a fragment for each channel */ 1385 bits = B; 1386 while (len > 0) { 1387 list = list->next; 1388 if (list == &ppp->channels) { 1389 i = 0; 1390 continue; 1391 } 1392 pch = list_entry(list, struct channel, clist); 1393 ++i; 1394 if (!pch->avail) 1395 continue; 1396 1397 /* 1398 * Skip this channel if it has a fragment pending already and 1399 * we haven't given a fragment to all of the free channels. 1400 */ 1401 if (pch->avail == 1) { 1402 if (nfree > 0) 1403 continue; 1404 } else { 1405 pch->avail = 1; 1406 } 1407 1408 /* check the channel's mtu and whether it is still attached. */ 1409 spin_lock_bh(&pch->downl); 1410 if (pch->chan == NULL) { 1411 /* can't use this channel, it's being deregistered */ 1412 if (pch->speed == 0) 1413 nzero--; 1414 else 1415 totspeed -= pch->speed; 1416 1417 spin_unlock_bh(&pch->downl); 1418 pch->avail = 0; 1419 totlen = len; 1420 totfree--; 1421 nfree--; 1422 if (--navail == 0) 1423 break; 1424 continue; 1425 } 1426 1427 /* 1428 *if the channel speed is not set divide 1429 *the packet evenly among the free channels; 1430 *otherwise divide it according to the speed 1431 *of the channel we are going to transmit on 1432 */ 1433 flen = len; 1434 if (nfree > 0) { 1435 if (pch->speed == 0) { 1436 flen = len/nfree; 1437 if (nbigger > 0) { 1438 flen++; 1439 nbigger--; 1440 } 1441 } else { 1442 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) / 1443 ((totspeed*totfree)/pch->speed)) - hdrlen; 1444 if (nbigger > 0) { 1445 flen += ((totfree - nzero)*pch->speed)/totspeed; 1446 nbigger -= ((totfree - nzero)*pch->speed)/ 1447 totspeed; 1448 } 1449 } 1450 nfree--; 1451 } 1452 1453 /* 1454 *check if we are on the last channel or 1455 *we exceded the length of the data to 1456 *fragment 1457 */ 1458 if ((nfree <= 0) || (flen > len)) 1459 flen = len; 1460 /* 1461 *it is not worth to tx on slow channels: 1462 *in that case from the resulting flen according to the 1463 *above formula will be equal or less than zero. 1464 *Skip the channel in this case 1465 */ 1466 if (flen <= 0) { 1467 pch->avail = 2; 1468 spin_unlock_bh(&pch->downl); 1469 continue; 1470 } 1471 1472 /* 1473 * hdrlen includes the 2-byte PPP protocol field, but the 1474 * MTU counts only the payload excluding the protocol field. 1475 * (RFC1661 Section 2) 1476 */ 1477 mtu = pch->chan->mtu - (hdrlen - 2); 1478 if (mtu < 4) 1479 mtu = 4; 1480 if (flen > mtu) 1481 flen = mtu; 1482 if (flen == len) 1483 bits |= E; 1484 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC); 1485 if (!frag) 1486 goto noskb; 1487 q = skb_put(frag, flen + hdrlen); 1488 1489 /* make the MP header */ 1490 put_unaligned_be16(PPP_MP, q); 1491 if (ppp->flags & SC_MP_XSHORTSEQ) { 1492 q[2] = bits + ((ppp->nxseq >> 8) & 0xf); 1493 q[3] = ppp->nxseq; 1494 } else { 1495 q[2] = bits; 1496 q[3] = ppp->nxseq >> 16; 1497 q[4] = ppp->nxseq >> 8; 1498 q[5] = ppp->nxseq; 1499 } 1500 1501 memcpy(q + hdrlen, p, flen); 1502 1503 /* try to send it down the channel */ 1504 chan = pch->chan; 1505 if (!skb_queue_empty(&pch->file.xq) || 1506 !chan->ops->start_xmit(chan, frag)) 1507 skb_queue_tail(&pch->file.xq, frag); 1508 pch->had_frag = 1; 1509 p += flen; 1510 len -= flen; 1511 ++ppp->nxseq; 1512 bits = 0; 1513 spin_unlock_bh(&pch->downl); 1514 } 1515 ppp->nxchan = i; 1516 1517 return 1; 1518 1519 noskb: 1520 spin_unlock_bh(&pch->downl); 1521 if (ppp->debug & 1) 1522 netdev_err(ppp->dev, "PPP: no memory (fragment)\n"); 1523 ++ppp->dev->stats.tx_errors; 1524 ++ppp->nxseq; 1525 return 1; /* abandon the frame */ 1526 } 1527 #endif /* CONFIG_PPP_MULTILINK */ 1528 1529 /* 1530 * Try to send data out on a channel. 1531 */ 1532 static void 1533 ppp_channel_push(struct channel *pch) 1534 { 1535 struct sk_buff *skb; 1536 struct ppp *ppp; 1537 1538 spin_lock_bh(&pch->downl); 1539 if (pch->chan) { 1540 while (!skb_queue_empty(&pch->file.xq)) { 1541 skb = skb_dequeue(&pch->file.xq); 1542 if (!pch->chan->ops->start_xmit(pch->chan, skb)) { 1543 /* put the packet back and try again later */ 1544 skb_queue_head(&pch->file.xq, skb); 1545 break; 1546 } 1547 } 1548 } else { 1549 /* channel got deregistered */ 1550 skb_queue_purge(&pch->file.xq); 1551 } 1552 spin_unlock_bh(&pch->downl); 1553 /* see if there is anything from the attached unit to be sent */ 1554 if (skb_queue_empty(&pch->file.xq)) { 1555 read_lock_bh(&pch->upl); 1556 ppp = pch->ppp; 1557 if (ppp) 1558 ppp_xmit_process(ppp); 1559 read_unlock_bh(&pch->upl); 1560 } 1561 } 1562 1563 /* 1564 * Receive-side routines. 1565 */ 1566 1567 struct ppp_mp_skb_parm { 1568 u32 sequence; 1569 u8 BEbits; 1570 }; 1571 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb)) 1572 1573 static inline void 1574 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1575 { 1576 ppp_recv_lock(ppp); 1577 if (!ppp->closing) 1578 ppp_receive_frame(ppp, skb, pch); 1579 else 1580 kfree_skb(skb); 1581 ppp_recv_unlock(ppp); 1582 } 1583 1584 void 1585 ppp_input(struct ppp_channel *chan, struct sk_buff *skb) 1586 { 1587 struct channel *pch = chan->ppp; 1588 int proto; 1589 1590 if (!pch) { 1591 kfree_skb(skb); 1592 return; 1593 } 1594 1595 read_lock_bh(&pch->upl); 1596 if (!pskb_may_pull(skb, 2)) { 1597 kfree_skb(skb); 1598 if (pch->ppp) { 1599 ++pch->ppp->dev->stats.rx_length_errors; 1600 ppp_receive_error(pch->ppp); 1601 } 1602 goto done; 1603 } 1604 1605 proto = PPP_PROTO(skb); 1606 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) { 1607 /* put it on the channel queue */ 1608 skb_queue_tail(&pch->file.rq, skb); 1609 /* drop old frames if queue too long */ 1610 while (pch->file.rq.qlen > PPP_MAX_RQLEN && 1611 (skb = skb_dequeue(&pch->file.rq))) 1612 kfree_skb(skb); 1613 wake_up_interruptible(&pch->file.rwait); 1614 } else { 1615 ppp_do_recv(pch->ppp, skb, pch); 1616 } 1617 1618 done: 1619 read_unlock_bh(&pch->upl); 1620 } 1621 1622 /* Put a 0-length skb in the receive queue as an error indication */ 1623 void 1624 ppp_input_error(struct ppp_channel *chan, int code) 1625 { 1626 struct channel *pch = chan->ppp; 1627 struct sk_buff *skb; 1628 1629 if (!pch) 1630 return; 1631 1632 read_lock_bh(&pch->upl); 1633 if (pch->ppp) { 1634 skb = alloc_skb(0, GFP_ATOMIC); 1635 if (skb) { 1636 skb->len = 0; /* probably unnecessary */ 1637 skb->cb[0] = code; 1638 ppp_do_recv(pch->ppp, skb, pch); 1639 } 1640 } 1641 read_unlock_bh(&pch->upl); 1642 } 1643 1644 /* 1645 * We come in here to process a received frame. 1646 * The receive side of the ppp unit is locked. 1647 */ 1648 static void 1649 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1650 { 1651 /* note: a 0-length skb is used as an error indication */ 1652 if (skb->len > 0) { 1653 #ifdef CONFIG_PPP_MULTILINK 1654 /* XXX do channel-level decompression here */ 1655 if (PPP_PROTO(skb) == PPP_MP) 1656 ppp_receive_mp_frame(ppp, skb, pch); 1657 else 1658 #endif /* CONFIG_PPP_MULTILINK */ 1659 ppp_receive_nonmp_frame(ppp, skb); 1660 } else { 1661 kfree_skb(skb); 1662 ppp_receive_error(ppp); 1663 } 1664 } 1665 1666 static void 1667 ppp_receive_error(struct ppp *ppp) 1668 { 1669 ++ppp->dev->stats.rx_errors; 1670 if (ppp->vj) 1671 slhc_toss(ppp->vj); 1672 } 1673 1674 static void 1675 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) 1676 { 1677 struct sk_buff *ns; 1678 int proto, len, npi; 1679 1680 /* 1681 * Decompress the frame, if compressed. 1682 * Note that some decompressors need to see uncompressed frames 1683 * that come in as well as compressed frames. 1684 */ 1685 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) && 1686 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0) 1687 skb = ppp_decompress_frame(ppp, skb); 1688 1689 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR) 1690 goto err; 1691 1692 proto = PPP_PROTO(skb); 1693 switch (proto) { 1694 case PPP_VJC_COMP: 1695 /* decompress VJ compressed packets */ 1696 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 1697 goto err; 1698 1699 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) { 1700 /* copy to a new sk_buff with more tailroom */ 1701 ns = dev_alloc_skb(skb->len + 128); 1702 if (!ns) { 1703 netdev_err(ppp->dev, "PPP: no memory " 1704 "(VJ decomp)\n"); 1705 goto err; 1706 } 1707 skb_reserve(ns, 2); 1708 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len); 1709 kfree_skb(skb); 1710 skb = ns; 1711 } 1712 else 1713 skb->ip_summed = CHECKSUM_NONE; 1714 1715 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2); 1716 if (len <= 0) { 1717 netdev_printk(KERN_DEBUG, ppp->dev, 1718 "PPP: VJ decompression error\n"); 1719 goto err; 1720 } 1721 len += 2; 1722 if (len > skb->len) 1723 skb_put(skb, len - skb->len); 1724 else if (len < skb->len) 1725 skb_trim(skb, len); 1726 proto = PPP_IP; 1727 break; 1728 1729 case PPP_VJC_UNCOMP: 1730 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 1731 goto err; 1732 1733 /* Until we fix the decompressor need to make sure 1734 * data portion is linear. 1735 */ 1736 if (!pskb_may_pull(skb, skb->len)) 1737 goto err; 1738 1739 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) { 1740 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n"); 1741 goto err; 1742 } 1743 proto = PPP_IP; 1744 break; 1745 1746 case PPP_CCP: 1747 ppp_ccp_peek(ppp, skb, 1); 1748 break; 1749 } 1750 1751 ++ppp->dev->stats.rx_packets; 1752 ppp->dev->stats.rx_bytes += skb->len - 2; 1753 1754 npi = proto_to_npindex(proto); 1755 if (npi < 0) { 1756 /* control or unknown frame - pass it to pppd */ 1757 skb_queue_tail(&ppp->file.rq, skb); 1758 /* limit queue length by dropping old frames */ 1759 while (ppp->file.rq.qlen > PPP_MAX_RQLEN && 1760 (skb = skb_dequeue(&ppp->file.rq))) 1761 kfree_skb(skb); 1762 /* wake up any process polling or blocking on read */ 1763 wake_up_interruptible(&ppp->file.rwait); 1764 1765 } else { 1766 /* network protocol frame - give it to the kernel */ 1767 1768 #ifdef CONFIG_PPP_FILTER 1769 /* check if the packet passes the pass and active filters */ 1770 /* the filter instructions are constructed assuming 1771 a four-byte PPP header on each packet */ 1772 if (ppp->pass_filter || ppp->active_filter) { 1773 if (skb_cloned(skb) && 1774 pskb_expand_head(skb, 0, 0, GFP_ATOMIC)) 1775 goto err; 1776 1777 *skb_push(skb, 2) = 0; 1778 if (ppp->pass_filter && 1779 sk_run_filter(skb, ppp->pass_filter) == 0) { 1780 if (ppp->debug & 1) 1781 netdev_printk(KERN_DEBUG, ppp->dev, 1782 "PPP: inbound frame " 1783 "not passed\n"); 1784 kfree_skb(skb); 1785 return; 1786 } 1787 if (!(ppp->active_filter && 1788 sk_run_filter(skb, ppp->active_filter) == 0)) 1789 ppp->last_recv = jiffies; 1790 __skb_pull(skb, 2); 1791 } else 1792 #endif /* CONFIG_PPP_FILTER */ 1793 ppp->last_recv = jiffies; 1794 1795 if ((ppp->dev->flags & IFF_UP) == 0 || 1796 ppp->npmode[npi] != NPMODE_PASS) { 1797 kfree_skb(skb); 1798 } else { 1799 /* chop off protocol */ 1800 skb_pull_rcsum(skb, 2); 1801 skb->dev = ppp->dev; 1802 skb->protocol = htons(npindex_to_ethertype[npi]); 1803 skb_reset_mac_header(skb); 1804 netif_rx(skb); 1805 } 1806 } 1807 return; 1808 1809 err: 1810 kfree_skb(skb); 1811 ppp_receive_error(ppp); 1812 } 1813 1814 static struct sk_buff * 1815 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb) 1816 { 1817 int proto = PPP_PROTO(skb); 1818 struct sk_buff *ns; 1819 int len; 1820 1821 /* Until we fix all the decompressor's need to make sure 1822 * data portion is linear. 1823 */ 1824 if (!pskb_may_pull(skb, skb->len)) 1825 goto err; 1826 1827 if (proto == PPP_COMP) { 1828 int obuff_size; 1829 1830 switch(ppp->rcomp->compress_proto) { 1831 case CI_MPPE: 1832 obuff_size = ppp->mru + PPP_HDRLEN + 1; 1833 break; 1834 default: 1835 obuff_size = ppp->mru + PPP_HDRLEN; 1836 break; 1837 } 1838 1839 ns = dev_alloc_skb(obuff_size); 1840 if (!ns) { 1841 netdev_err(ppp->dev, "ppp_decompress_frame: " 1842 "no memory\n"); 1843 goto err; 1844 } 1845 /* the decompressor still expects the A/C bytes in the hdr */ 1846 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2, 1847 skb->len + 2, ns->data, obuff_size); 1848 if (len < 0) { 1849 /* Pass the compressed frame to pppd as an 1850 error indication. */ 1851 if (len == DECOMP_FATALERROR) 1852 ppp->rstate |= SC_DC_FERROR; 1853 kfree_skb(ns); 1854 goto err; 1855 } 1856 1857 kfree_skb(skb); 1858 skb = ns; 1859 skb_put(skb, len); 1860 skb_pull(skb, 2); /* pull off the A/C bytes */ 1861 1862 } else { 1863 /* Uncompressed frame - pass to decompressor so it 1864 can update its dictionary if necessary. */ 1865 if (ppp->rcomp->incomp) 1866 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2, 1867 skb->len + 2); 1868 } 1869 1870 return skb; 1871 1872 err: 1873 ppp->rstate |= SC_DC_ERROR; 1874 ppp_receive_error(ppp); 1875 return skb; 1876 } 1877 1878 #ifdef CONFIG_PPP_MULTILINK 1879 /* 1880 * Receive a multilink frame. 1881 * We put it on the reconstruction queue and then pull off 1882 * as many completed frames as we can. 1883 */ 1884 static void 1885 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1886 { 1887 u32 mask, seq; 1888 struct channel *ch; 1889 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1890 1891 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0) 1892 goto err; /* no good, throw it away */ 1893 1894 /* Decode sequence number and begin/end bits */ 1895 if (ppp->flags & SC_MP_SHORTSEQ) { 1896 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3]; 1897 mask = 0xfff; 1898 } else { 1899 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5]; 1900 mask = 0xffffff; 1901 } 1902 PPP_MP_CB(skb)->BEbits = skb->data[2]; 1903 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */ 1904 1905 /* 1906 * Do protocol ID decompression on the first fragment of each packet. 1907 */ 1908 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1)) 1909 *skb_push(skb, 1) = 0; 1910 1911 /* 1912 * Expand sequence number to 32 bits, making it as close 1913 * as possible to ppp->minseq. 1914 */ 1915 seq |= ppp->minseq & ~mask; 1916 if ((int)(ppp->minseq - seq) > (int)(mask >> 1)) 1917 seq += mask + 1; 1918 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1)) 1919 seq -= mask + 1; /* should never happen */ 1920 PPP_MP_CB(skb)->sequence = seq; 1921 pch->lastseq = seq; 1922 1923 /* 1924 * If this packet comes before the next one we were expecting, 1925 * drop it. 1926 */ 1927 if (seq_before(seq, ppp->nextseq)) { 1928 kfree_skb(skb); 1929 ++ppp->dev->stats.rx_dropped; 1930 ppp_receive_error(ppp); 1931 return; 1932 } 1933 1934 /* 1935 * Reevaluate minseq, the minimum over all channels of the 1936 * last sequence number received on each channel. Because of 1937 * the increasing sequence number rule, we know that any fragment 1938 * before `minseq' which hasn't arrived is never going to arrive. 1939 * The list of channels can't change because we have the receive 1940 * side of the ppp unit locked. 1941 */ 1942 list_for_each_entry(ch, &ppp->channels, clist) { 1943 if (seq_before(ch->lastseq, seq)) 1944 seq = ch->lastseq; 1945 } 1946 if (seq_before(ppp->minseq, seq)) 1947 ppp->minseq = seq; 1948 1949 /* Put the fragment on the reconstruction queue */ 1950 ppp_mp_insert(ppp, skb); 1951 1952 /* If the queue is getting long, don't wait any longer for packets 1953 before the start of the queue. */ 1954 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) { 1955 struct sk_buff *mskb = skb_peek(&ppp->mrq); 1956 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence)) 1957 ppp->minseq = PPP_MP_CB(mskb)->sequence; 1958 } 1959 1960 /* Pull completed packets off the queue and receive them. */ 1961 while ((skb = ppp_mp_reconstruct(ppp))) { 1962 if (pskb_may_pull(skb, 2)) 1963 ppp_receive_nonmp_frame(ppp, skb); 1964 else { 1965 ++ppp->dev->stats.rx_length_errors; 1966 kfree_skb(skb); 1967 ppp_receive_error(ppp); 1968 } 1969 } 1970 1971 return; 1972 1973 err: 1974 kfree_skb(skb); 1975 ppp_receive_error(ppp); 1976 } 1977 1978 /* 1979 * Insert a fragment on the MP reconstruction queue. 1980 * The queue is ordered by increasing sequence number. 1981 */ 1982 static void 1983 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb) 1984 { 1985 struct sk_buff *p; 1986 struct sk_buff_head *list = &ppp->mrq; 1987 u32 seq = PPP_MP_CB(skb)->sequence; 1988 1989 /* N.B. we don't need to lock the list lock because we have the 1990 ppp unit receive-side lock. */ 1991 skb_queue_walk(list, p) { 1992 if (seq_before(seq, PPP_MP_CB(p)->sequence)) 1993 break; 1994 } 1995 __skb_queue_before(list, p, skb); 1996 } 1997 1998 /* 1999 * Reconstruct a packet from the MP fragment queue. 2000 * We go through increasing sequence numbers until we find a 2001 * complete packet, or we get to the sequence number for a fragment 2002 * which hasn't arrived but might still do so. 2003 */ 2004 static struct sk_buff * 2005 ppp_mp_reconstruct(struct ppp *ppp) 2006 { 2007 u32 seq = ppp->nextseq; 2008 u32 minseq = ppp->minseq; 2009 struct sk_buff_head *list = &ppp->mrq; 2010 struct sk_buff *p, *tmp; 2011 struct sk_buff *head, *tail; 2012 struct sk_buff *skb = NULL; 2013 int lost = 0, len = 0; 2014 2015 if (ppp->mrru == 0) /* do nothing until mrru is set */ 2016 return NULL; 2017 head = list->next; 2018 tail = NULL; 2019 skb_queue_walk_safe(list, p, tmp) { 2020 again: 2021 if (seq_before(PPP_MP_CB(p)->sequence, seq)) { 2022 /* this can't happen, anyway ignore the skb */ 2023 netdev_err(ppp->dev, "ppp_mp_reconstruct bad " 2024 "seq %u < %u\n", 2025 PPP_MP_CB(p)->sequence, seq); 2026 __skb_unlink(p, list); 2027 kfree_skb(p); 2028 continue; 2029 } 2030 if (PPP_MP_CB(p)->sequence != seq) { 2031 u32 oldseq; 2032 /* Fragment `seq' is missing. If it is after 2033 minseq, it might arrive later, so stop here. */ 2034 if (seq_after(seq, minseq)) 2035 break; 2036 /* Fragment `seq' is lost, keep going. */ 2037 lost = 1; 2038 oldseq = seq; 2039 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)? 2040 minseq + 1: PPP_MP_CB(p)->sequence; 2041 2042 if (ppp->debug & 1) 2043 netdev_printk(KERN_DEBUG, ppp->dev, 2044 "lost frag %u..%u\n", 2045 oldseq, seq-1); 2046 2047 goto again; 2048 } 2049 2050 /* 2051 * At this point we know that all the fragments from 2052 * ppp->nextseq to seq are either present or lost. 2053 * Also, there are no complete packets in the queue 2054 * that have no missing fragments and end before this 2055 * fragment. 2056 */ 2057 2058 /* B bit set indicates this fragment starts a packet */ 2059 if (PPP_MP_CB(p)->BEbits & B) { 2060 head = p; 2061 lost = 0; 2062 len = 0; 2063 } 2064 2065 len += p->len; 2066 2067 /* Got a complete packet yet? */ 2068 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) && 2069 (PPP_MP_CB(head)->BEbits & B)) { 2070 if (len > ppp->mrru + 2) { 2071 ++ppp->dev->stats.rx_length_errors; 2072 netdev_printk(KERN_DEBUG, ppp->dev, 2073 "PPP: reconstructed packet" 2074 " is too long (%d)\n", len); 2075 } else { 2076 tail = p; 2077 break; 2078 } 2079 ppp->nextseq = seq + 1; 2080 } 2081 2082 /* 2083 * If this is the ending fragment of a packet, 2084 * and we haven't found a complete valid packet yet, 2085 * we can discard up to and including this fragment. 2086 */ 2087 if (PPP_MP_CB(p)->BEbits & E) { 2088 struct sk_buff *tmp2; 2089 2090 skb_queue_reverse_walk_from_safe(list, p, tmp2) { 2091 if (ppp->debug & 1) 2092 netdev_printk(KERN_DEBUG, ppp->dev, 2093 "discarding frag %u\n", 2094 PPP_MP_CB(p)->sequence); 2095 __skb_unlink(p, list); 2096 kfree_skb(p); 2097 } 2098 head = skb_peek(list); 2099 if (!head) 2100 break; 2101 } 2102 ++seq; 2103 } 2104 2105 /* If we have a complete packet, copy it all into one skb. */ 2106 if (tail != NULL) { 2107 /* If we have discarded any fragments, 2108 signal a receive error. */ 2109 if (PPP_MP_CB(head)->sequence != ppp->nextseq) { 2110 skb_queue_walk_safe(list, p, tmp) { 2111 if (p == head) 2112 break; 2113 if (ppp->debug & 1) 2114 netdev_printk(KERN_DEBUG, ppp->dev, 2115 "discarding frag %u\n", 2116 PPP_MP_CB(p)->sequence); 2117 __skb_unlink(p, list); 2118 kfree_skb(p); 2119 } 2120 2121 if (ppp->debug & 1) 2122 netdev_printk(KERN_DEBUG, ppp->dev, 2123 " missed pkts %u..%u\n", 2124 ppp->nextseq, 2125 PPP_MP_CB(head)->sequence-1); 2126 ++ppp->dev->stats.rx_dropped; 2127 ppp_receive_error(ppp); 2128 } 2129 2130 skb = head; 2131 if (head != tail) { 2132 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list; 2133 p = skb_queue_next(list, head); 2134 __skb_unlink(skb, list); 2135 skb_queue_walk_from_safe(list, p, tmp) { 2136 __skb_unlink(p, list); 2137 *fragpp = p; 2138 p->next = NULL; 2139 fragpp = &p->next; 2140 2141 skb->len += p->len; 2142 skb->data_len += p->len; 2143 skb->truesize += p->truesize; 2144 2145 if (p == tail) 2146 break; 2147 } 2148 } else { 2149 __skb_unlink(skb, list); 2150 } 2151 2152 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1; 2153 } 2154 2155 return skb; 2156 } 2157 #endif /* CONFIG_PPP_MULTILINK */ 2158 2159 /* 2160 * Channel interface. 2161 */ 2162 2163 /* Create a new, unattached ppp channel. */ 2164 int ppp_register_channel(struct ppp_channel *chan) 2165 { 2166 return ppp_register_net_channel(current->nsproxy->net_ns, chan); 2167 } 2168 2169 /* Create a new, unattached ppp channel for specified net. */ 2170 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan) 2171 { 2172 struct channel *pch; 2173 struct ppp_net *pn; 2174 2175 pch = kzalloc(sizeof(struct channel), GFP_KERNEL); 2176 if (!pch) 2177 return -ENOMEM; 2178 2179 pn = ppp_pernet(net); 2180 2181 pch->ppp = NULL; 2182 pch->chan = chan; 2183 pch->chan_net = net; 2184 chan->ppp = pch; 2185 init_ppp_file(&pch->file, CHANNEL); 2186 pch->file.hdrlen = chan->hdrlen; 2187 #ifdef CONFIG_PPP_MULTILINK 2188 pch->lastseq = -1; 2189 #endif /* CONFIG_PPP_MULTILINK */ 2190 init_rwsem(&pch->chan_sem); 2191 spin_lock_init(&pch->downl); 2192 rwlock_init(&pch->upl); 2193 2194 spin_lock_bh(&pn->all_channels_lock); 2195 pch->file.index = ++pn->last_channel_index; 2196 list_add(&pch->list, &pn->new_channels); 2197 atomic_inc(&channel_count); 2198 spin_unlock_bh(&pn->all_channels_lock); 2199 2200 return 0; 2201 } 2202 2203 /* 2204 * Return the index of a channel. 2205 */ 2206 int ppp_channel_index(struct ppp_channel *chan) 2207 { 2208 struct channel *pch = chan->ppp; 2209 2210 if (pch) 2211 return pch->file.index; 2212 return -1; 2213 } 2214 2215 /* 2216 * Return the PPP unit number to which a channel is connected. 2217 */ 2218 int ppp_unit_number(struct ppp_channel *chan) 2219 { 2220 struct channel *pch = chan->ppp; 2221 int unit = -1; 2222 2223 if (pch) { 2224 read_lock_bh(&pch->upl); 2225 if (pch->ppp) 2226 unit = pch->ppp->file.index; 2227 read_unlock_bh(&pch->upl); 2228 } 2229 return unit; 2230 } 2231 2232 /* 2233 * Return the PPP device interface name of a channel. 2234 */ 2235 char *ppp_dev_name(struct ppp_channel *chan) 2236 { 2237 struct channel *pch = chan->ppp; 2238 char *name = NULL; 2239 2240 if (pch) { 2241 read_lock_bh(&pch->upl); 2242 if (pch->ppp && pch->ppp->dev) 2243 name = pch->ppp->dev->name; 2244 read_unlock_bh(&pch->upl); 2245 } 2246 return name; 2247 } 2248 2249 2250 /* 2251 * Disconnect a channel from the generic layer. 2252 * This must be called in process context. 2253 */ 2254 void 2255 ppp_unregister_channel(struct ppp_channel *chan) 2256 { 2257 struct channel *pch = chan->ppp; 2258 struct ppp_net *pn; 2259 2260 if (!pch) 2261 return; /* should never happen */ 2262 2263 chan->ppp = NULL; 2264 2265 /* 2266 * This ensures that we have returned from any calls into the 2267 * the channel's start_xmit or ioctl routine before we proceed. 2268 */ 2269 down_write(&pch->chan_sem); 2270 spin_lock_bh(&pch->downl); 2271 pch->chan = NULL; 2272 spin_unlock_bh(&pch->downl); 2273 up_write(&pch->chan_sem); 2274 ppp_disconnect_channel(pch); 2275 2276 pn = ppp_pernet(pch->chan_net); 2277 spin_lock_bh(&pn->all_channels_lock); 2278 list_del(&pch->list); 2279 spin_unlock_bh(&pn->all_channels_lock); 2280 2281 pch->file.dead = 1; 2282 wake_up_interruptible(&pch->file.rwait); 2283 if (atomic_dec_and_test(&pch->file.refcnt)) 2284 ppp_destroy_channel(pch); 2285 } 2286 2287 /* 2288 * Callback from a channel when it can accept more to transmit. 2289 * This should be called at BH/softirq level, not interrupt level. 2290 */ 2291 void 2292 ppp_output_wakeup(struct ppp_channel *chan) 2293 { 2294 struct channel *pch = chan->ppp; 2295 2296 if (!pch) 2297 return; 2298 ppp_channel_push(pch); 2299 } 2300 2301 /* 2302 * Compression control. 2303 */ 2304 2305 /* Process the PPPIOCSCOMPRESS ioctl. */ 2306 static int 2307 ppp_set_compress(struct ppp *ppp, unsigned long arg) 2308 { 2309 int err; 2310 struct compressor *cp, *ocomp; 2311 struct ppp_option_data data; 2312 void *state, *ostate; 2313 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH]; 2314 2315 err = -EFAULT; 2316 if (copy_from_user(&data, (void __user *) arg, sizeof(data)) || 2317 (data.length <= CCP_MAX_OPTION_LENGTH && 2318 copy_from_user(ccp_option, (void __user *) data.ptr, data.length))) 2319 goto out; 2320 err = -EINVAL; 2321 if (data.length > CCP_MAX_OPTION_LENGTH || 2322 ccp_option[1] < 2 || ccp_option[1] > data.length) 2323 goto out; 2324 2325 cp = try_then_request_module( 2326 find_compressor(ccp_option[0]), 2327 "ppp-compress-%d", ccp_option[0]); 2328 if (!cp) 2329 goto out; 2330 2331 err = -ENOBUFS; 2332 if (data.transmit) { 2333 state = cp->comp_alloc(ccp_option, data.length); 2334 if (state) { 2335 ppp_xmit_lock(ppp); 2336 ppp->xstate &= ~SC_COMP_RUN; 2337 ocomp = ppp->xcomp; 2338 ostate = ppp->xc_state; 2339 ppp->xcomp = cp; 2340 ppp->xc_state = state; 2341 ppp_xmit_unlock(ppp); 2342 if (ostate) { 2343 ocomp->comp_free(ostate); 2344 module_put(ocomp->owner); 2345 } 2346 err = 0; 2347 } else 2348 module_put(cp->owner); 2349 2350 } else { 2351 state = cp->decomp_alloc(ccp_option, data.length); 2352 if (state) { 2353 ppp_recv_lock(ppp); 2354 ppp->rstate &= ~SC_DECOMP_RUN; 2355 ocomp = ppp->rcomp; 2356 ostate = ppp->rc_state; 2357 ppp->rcomp = cp; 2358 ppp->rc_state = state; 2359 ppp_recv_unlock(ppp); 2360 if (ostate) { 2361 ocomp->decomp_free(ostate); 2362 module_put(ocomp->owner); 2363 } 2364 err = 0; 2365 } else 2366 module_put(cp->owner); 2367 } 2368 2369 out: 2370 return err; 2371 } 2372 2373 /* 2374 * Look at a CCP packet and update our state accordingly. 2375 * We assume the caller has the xmit or recv path locked. 2376 */ 2377 static void 2378 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound) 2379 { 2380 unsigned char *dp; 2381 int len; 2382 2383 if (!pskb_may_pull(skb, CCP_HDRLEN + 2)) 2384 return; /* no header */ 2385 dp = skb->data + 2; 2386 2387 switch (CCP_CODE(dp)) { 2388 case CCP_CONFREQ: 2389 2390 /* A ConfReq starts negotiation of compression 2391 * in one direction of transmission, 2392 * and hence brings it down...but which way? 2393 * 2394 * Remember: 2395 * A ConfReq indicates what the sender would like to receive 2396 */ 2397 if(inbound) 2398 /* He is proposing what I should send */ 2399 ppp->xstate &= ~SC_COMP_RUN; 2400 else 2401 /* I am proposing to what he should send */ 2402 ppp->rstate &= ~SC_DECOMP_RUN; 2403 2404 break; 2405 2406 case CCP_TERMREQ: 2407 case CCP_TERMACK: 2408 /* 2409 * CCP is going down, both directions of transmission 2410 */ 2411 ppp->rstate &= ~SC_DECOMP_RUN; 2412 ppp->xstate &= ~SC_COMP_RUN; 2413 break; 2414 2415 case CCP_CONFACK: 2416 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN) 2417 break; 2418 len = CCP_LENGTH(dp); 2419 if (!pskb_may_pull(skb, len + 2)) 2420 return; /* too short */ 2421 dp += CCP_HDRLEN; 2422 len -= CCP_HDRLEN; 2423 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp)) 2424 break; 2425 if (inbound) { 2426 /* we will start receiving compressed packets */ 2427 if (!ppp->rc_state) 2428 break; 2429 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len, 2430 ppp->file.index, 0, ppp->mru, ppp->debug)) { 2431 ppp->rstate |= SC_DECOMP_RUN; 2432 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR); 2433 } 2434 } else { 2435 /* we will soon start sending compressed packets */ 2436 if (!ppp->xc_state) 2437 break; 2438 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len, 2439 ppp->file.index, 0, ppp->debug)) 2440 ppp->xstate |= SC_COMP_RUN; 2441 } 2442 break; 2443 2444 case CCP_RESETACK: 2445 /* reset the [de]compressor */ 2446 if ((ppp->flags & SC_CCP_UP) == 0) 2447 break; 2448 if (inbound) { 2449 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) { 2450 ppp->rcomp->decomp_reset(ppp->rc_state); 2451 ppp->rstate &= ~SC_DC_ERROR; 2452 } 2453 } else { 2454 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN)) 2455 ppp->xcomp->comp_reset(ppp->xc_state); 2456 } 2457 break; 2458 } 2459 } 2460 2461 /* Free up compression resources. */ 2462 static void 2463 ppp_ccp_closed(struct ppp *ppp) 2464 { 2465 void *xstate, *rstate; 2466 struct compressor *xcomp, *rcomp; 2467 2468 ppp_lock(ppp); 2469 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP); 2470 ppp->xstate = 0; 2471 xcomp = ppp->xcomp; 2472 xstate = ppp->xc_state; 2473 ppp->xc_state = NULL; 2474 ppp->rstate = 0; 2475 rcomp = ppp->rcomp; 2476 rstate = ppp->rc_state; 2477 ppp->rc_state = NULL; 2478 ppp_unlock(ppp); 2479 2480 if (xstate) { 2481 xcomp->comp_free(xstate); 2482 module_put(xcomp->owner); 2483 } 2484 if (rstate) { 2485 rcomp->decomp_free(rstate); 2486 module_put(rcomp->owner); 2487 } 2488 } 2489 2490 /* List of compressors. */ 2491 static LIST_HEAD(compressor_list); 2492 static DEFINE_SPINLOCK(compressor_list_lock); 2493 2494 struct compressor_entry { 2495 struct list_head list; 2496 struct compressor *comp; 2497 }; 2498 2499 static struct compressor_entry * 2500 find_comp_entry(int proto) 2501 { 2502 struct compressor_entry *ce; 2503 2504 list_for_each_entry(ce, &compressor_list, list) { 2505 if (ce->comp->compress_proto == proto) 2506 return ce; 2507 } 2508 return NULL; 2509 } 2510 2511 /* Register a compressor */ 2512 int 2513 ppp_register_compressor(struct compressor *cp) 2514 { 2515 struct compressor_entry *ce; 2516 int ret; 2517 spin_lock(&compressor_list_lock); 2518 ret = -EEXIST; 2519 if (find_comp_entry(cp->compress_proto)) 2520 goto out; 2521 ret = -ENOMEM; 2522 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC); 2523 if (!ce) 2524 goto out; 2525 ret = 0; 2526 ce->comp = cp; 2527 list_add(&ce->list, &compressor_list); 2528 out: 2529 spin_unlock(&compressor_list_lock); 2530 return ret; 2531 } 2532 2533 /* Unregister a compressor */ 2534 void 2535 ppp_unregister_compressor(struct compressor *cp) 2536 { 2537 struct compressor_entry *ce; 2538 2539 spin_lock(&compressor_list_lock); 2540 ce = find_comp_entry(cp->compress_proto); 2541 if (ce && ce->comp == cp) { 2542 list_del(&ce->list); 2543 kfree(ce); 2544 } 2545 spin_unlock(&compressor_list_lock); 2546 } 2547 2548 /* Find a compressor. */ 2549 static struct compressor * 2550 find_compressor(int type) 2551 { 2552 struct compressor_entry *ce; 2553 struct compressor *cp = NULL; 2554 2555 spin_lock(&compressor_list_lock); 2556 ce = find_comp_entry(type); 2557 if (ce) { 2558 cp = ce->comp; 2559 if (!try_module_get(cp->owner)) 2560 cp = NULL; 2561 } 2562 spin_unlock(&compressor_list_lock); 2563 return cp; 2564 } 2565 2566 /* 2567 * Miscelleneous stuff. 2568 */ 2569 2570 static void 2571 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st) 2572 { 2573 struct slcompress *vj = ppp->vj; 2574 2575 memset(st, 0, sizeof(*st)); 2576 st->p.ppp_ipackets = ppp->dev->stats.rx_packets; 2577 st->p.ppp_ierrors = ppp->dev->stats.rx_errors; 2578 st->p.ppp_ibytes = ppp->dev->stats.rx_bytes; 2579 st->p.ppp_opackets = ppp->dev->stats.tx_packets; 2580 st->p.ppp_oerrors = ppp->dev->stats.tx_errors; 2581 st->p.ppp_obytes = ppp->dev->stats.tx_bytes; 2582 if (!vj) 2583 return; 2584 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed; 2585 st->vj.vjs_compressed = vj->sls_o_compressed; 2586 st->vj.vjs_searches = vj->sls_o_searches; 2587 st->vj.vjs_misses = vj->sls_o_misses; 2588 st->vj.vjs_errorin = vj->sls_i_error; 2589 st->vj.vjs_tossed = vj->sls_i_tossed; 2590 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed; 2591 st->vj.vjs_compressedin = vj->sls_i_compressed; 2592 } 2593 2594 /* 2595 * Stuff for handling the lists of ppp units and channels 2596 * and for initialization. 2597 */ 2598 2599 /* 2600 * Create a new ppp interface unit. Fails if it can't allocate memory 2601 * or if there is already a unit with the requested number. 2602 * unit == -1 means allocate a new number. 2603 */ 2604 static struct ppp * 2605 ppp_create_interface(struct net *net, int unit, int *retp) 2606 { 2607 struct ppp *ppp; 2608 struct ppp_net *pn; 2609 struct net_device *dev = NULL; 2610 int ret = -ENOMEM; 2611 int i; 2612 2613 dev = alloc_netdev(sizeof(struct ppp), "", ppp_setup); 2614 if (!dev) 2615 goto out1; 2616 2617 pn = ppp_pernet(net); 2618 2619 ppp = netdev_priv(dev); 2620 ppp->dev = dev; 2621 ppp->mru = PPP_MRU; 2622 init_ppp_file(&ppp->file, INTERFACE); 2623 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */ 2624 for (i = 0; i < NUM_NP; ++i) 2625 ppp->npmode[i] = NPMODE_PASS; 2626 INIT_LIST_HEAD(&ppp->channels); 2627 spin_lock_init(&ppp->rlock); 2628 spin_lock_init(&ppp->wlock); 2629 #ifdef CONFIG_PPP_MULTILINK 2630 ppp->minseq = -1; 2631 skb_queue_head_init(&ppp->mrq); 2632 #endif /* CONFIG_PPP_MULTILINK */ 2633 2634 /* 2635 * drum roll: don't forget to set 2636 * the net device is belong to 2637 */ 2638 dev_net_set(dev, net); 2639 2640 mutex_lock(&pn->all_ppp_mutex); 2641 2642 if (unit < 0) { 2643 unit = unit_get(&pn->units_idr, ppp); 2644 if (unit < 0) { 2645 ret = unit; 2646 goto out2; 2647 } 2648 } else { 2649 ret = -EEXIST; 2650 if (unit_find(&pn->units_idr, unit)) 2651 goto out2; /* unit already exists */ 2652 /* 2653 * if caller need a specified unit number 2654 * lets try to satisfy him, otherwise -- 2655 * he should better ask us for new unit number 2656 * 2657 * NOTE: yes I know that returning EEXIST it's not 2658 * fair but at least pppd will ask us to allocate 2659 * new unit in this case so user is happy :) 2660 */ 2661 unit = unit_set(&pn->units_idr, ppp, unit); 2662 if (unit < 0) 2663 goto out2; 2664 } 2665 2666 /* Initialize the new ppp unit */ 2667 ppp->file.index = unit; 2668 sprintf(dev->name, "ppp%d", unit); 2669 2670 ret = register_netdev(dev); 2671 if (ret != 0) { 2672 unit_put(&pn->units_idr, unit); 2673 netdev_err(ppp->dev, "PPP: couldn't register device %s (%d)\n", 2674 dev->name, ret); 2675 goto out2; 2676 } 2677 2678 ppp->ppp_net = net; 2679 2680 atomic_inc(&ppp_unit_count); 2681 mutex_unlock(&pn->all_ppp_mutex); 2682 2683 *retp = 0; 2684 return ppp; 2685 2686 out2: 2687 mutex_unlock(&pn->all_ppp_mutex); 2688 free_netdev(dev); 2689 out1: 2690 *retp = ret; 2691 return NULL; 2692 } 2693 2694 /* 2695 * Initialize a ppp_file structure. 2696 */ 2697 static void 2698 init_ppp_file(struct ppp_file *pf, int kind) 2699 { 2700 pf->kind = kind; 2701 skb_queue_head_init(&pf->xq); 2702 skb_queue_head_init(&pf->rq); 2703 atomic_set(&pf->refcnt, 1); 2704 init_waitqueue_head(&pf->rwait); 2705 } 2706 2707 /* 2708 * Take down a ppp interface unit - called when the owning file 2709 * (the one that created the unit) is closed or detached. 2710 */ 2711 static void ppp_shutdown_interface(struct ppp *ppp) 2712 { 2713 struct ppp_net *pn; 2714 2715 pn = ppp_pernet(ppp->ppp_net); 2716 mutex_lock(&pn->all_ppp_mutex); 2717 2718 /* This will call dev_close() for us. */ 2719 ppp_lock(ppp); 2720 if (!ppp->closing) { 2721 ppp->closing = 1; 2722 ppp_unlock(ppp); 2723 unregister_netdev(ppp->dev); 2724 unit_put(&pn->units_idr, ppp->file.index); 2725 } else 2726 ppp_unlock(ppp); 2727 2728 ppp->file.dead = 1; 2729 ppp->owner = NULL; 2730 wake_up_interruptible(&ppp->file.rwait); 2731 2732 mutex_unlock(&pn->all_ppp_mutex); 2733 } 2734 2735 /* 2736 * Free the memory used by a ppp unit. This is only called once 2737 * there are no channels connected to the unit and no file structs 2738 * that reference the unit. 2739 */ 2740 static void ppp_destroy_interface(struct ppp *ppp) 2741 { 2742 atomic_dec(&ppp_unit_count); 2743 2744 if (!ppp->file.dead || ppp->n_channels) { 2745 /* "can't happen" */ 2746 netdev_err(ppp->dev, "ppp: destroying ppp struct %p " 2747 "but dead=%d n_channels=%d !\n", 2748 ppp, ppp->file.dead, ppp->n_channels); 2749 return; 2750 } 2751 2752 ppp_ccp_closed(ppp); 2753 if (ppp->vj) { 2754 slhc_free(ppp->vj); 2755 ppp->vj = NULL; 2756 } 2757 skb_queue_purge(&ppp->file.xq); 2758 skb_queue_purge(&ppp->file.rq); 2759 #ifdef CONFIG_PPP_MULTILINK 2760 skb_queue_purge(&ppp->mrq); 2761 #endif /* CONFIG_PPP_MULTILINK */ 2762 #ifdef CONFIG_PPP_FILTER 2763 kfree(ppp->pass_filter); 2764 ppp->pass_filter = NULL; 2765 kfree(ppp->active_filter); 2766 ppp->active_filter = NULL; 2767 #endif /* CONFIG_PPP_FILTER */ 2768 2769 kfree_skb(ppp->xmit_pending); 2770 2771 free_netdev(ppp->dev); 2772 } 2773 2774 /* 2775 * Locate an existing ppp unit. 2776 * The caller should have locked the all_ppp_mutex. 2777 */ 2778 static struct ppp * 2779 ppp_find_unit(struct ppp_net *pn, int unit) 2780 { 2781 return unit_find(&pn->units_idr, unit); 2782 } 2783 2784 /* 2785 * Locate an existing ppp channel. 2786 * The caller should have locked the all_channels_lock. 2787 * First we look in the new_channels list, then in the 2788 * all_channels list. If found in the new_channels list, 2789 * we move it to the all_channels list. This is for speed 2790 * when we have a lot of channels in use. 2791 */ 2792 static struct channel * 2793 ppp_find_channel(struct ppp_net *pn, int unit) 2794 { 2795 struct channel *pch; 2796 2797 list_for_each_entry(pch, &pn->new_channels, list) { 2798 if (pch->file.index == unit) { 2799 list_move(&pch->list, &pn->all_channels); 2800 return pch; 2801 } 2802 } 2803 2804 list_for_each_entry(pch, &pn->all_channels, list) { 2805 if (pch->file.index == unit) 2806 return pch; 2807 } 2808 2809 return NULL; 2810 } 2811 2812 /* 2813 * Connect a PPP channel to a PPP interface unit. 2814 */ 2815 static int 2816 ppp_connect_channel(struct channel *pch, int unit) 2817 { 2818 struct ppp *ppp; 2819 struct ppp_net *pn; 2820 int ret = -ENXIO; 2821 int hdrlen; 2822 2823 pn = ppp_pernet(pch->chan_net); 2824 2825 mutex_lock(&pn->all_ppp_mutex); 2826 ppp = ppp_find_unit(pn, unit); 2827 if (!ppp) 2828 goto out; 2829 write_lock_bh(&pch->upl); 2830 ret = -EINVAL; 2831 if (pch->ppp) 2832 goto outl; 2833 2834 ppp_lock(ppp); 2835 if (pch->file.hdrlen > ppp->file.hdrlen) 2836 ppp->file.hdrlen = pch->file.hdrlen; 2837 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */ 2838 if (hdrlen > ppp->dev->hard_header_len) 2839 ppp->dev->hard_header_len = hdrlen; 2840 list_add_tail(&pch->clist, &ppp->channels); 2841 ++ppp->n_channels; 2842 pch->ppp = ppp; 2843 atomic_inc(&ppp->file.refcnt); 2844 ppp_unlock(ppp); 2845 ret = 0; 2846 2847 outl: 2848 write_unlock_bh(&pch->upl); 2849 out: 2850 mutex_unlock(&pn->all_ppp_mutex); 2851 return ret; 2852 } 2853 2854 /* 2855 * Disconnect a channel from its ppp unit. 2856 */ 2857 static int 2858 ppp_disconnect_channel(struct channel *pch) 2859 { 2860 struct ppp *ppp; 2861 int err = -EINVAL; 2862 2863 write_lock_bh(&pch->upl); 2864 ppp = pch->ppp; 2865 pch->ppp = NULL; 2866 write_unlock_bh(&pch->upl); 2867 if (ppp) { 2868 /* remove it from the ppp unit's list */ 2869 ppp_lock(ppp); 2870 list_del(&pch->clist); 2871 if (--ppp->n_channels == 0) 2872 wake_up_interruptible(&ppp->file.rwait); 2873 ppp_unlock(ppp); 2874 if (atomic_dec_and_test(&ppp->file.refcnt)) 2875 ppp_destroy_interface(ppp); 2876 err = 0; 2877 } 2878 return err; 2879 } 2880 2881 /* 2882 * Free up the resources used by a ppp channel. 2883 */ 2884 static void ppp_destroy_channel(struct channel *pch) 2885 { 2886 atomic_dec(&channel_count); 2887 2888 if (!pch->file.dead) { 2889 /* "can't happen" */ 2890 pr_err("ppp: destroying undead channel %p !\n", pch); 2891 return; 2892 } 2893 skb_queue_purge(&pch->file.xq); 2894 skb_queue_purge(&pch->file.rq); 2895 kfree(pch); 2896 } 2897 2898 static void __exit ppp_cleanup(void) 2899 { 2900 /* should never happen */ 2901 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count)) 2902 pr_err("PPP: removing module but units remain!\n"); 2903 unregister_chrdev(PPP_MAJOR, "ppp"); 2904 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0)); 2905 class_destroy(ppp_class); 2906 unregister_pernet_device(&ppp_net_ops); 2907 } 2908 2909 /* 2910 * Units handling. Caller must protect concurrent access 2911 * by holding all_ppp_mutex 2912 */ 2913 2914 static int __unit_alloc(struct idr *p, void *ptr, int n) 2915 { 2916 int unit, err; 2917 2918 again: 2919 if (!idr_pre_get(p, GFP_KERNEL)) { 2920 pr_err("PPP: No free memory for idr\n"); 2921 return -ENOMEM; 2922 } 2923 2924 err = idr_get_new_above(p, ptr, n, &unit); 2925 if (err < 0) { 2926 if (err == -EAGAIN) 2927 goto again; 2928 return err; 2929 } 2930 2931 return unit; 2932 } 2933 2934 /* associate pointer with specified number */ 2935 static int unit_set(struct idr *p, void *ptr, int n) 2936 { 2937 int unit; 2938 2939 unit = __unit_alloc(p, ptr, n); 2940 if (unit < 0) 2941 return unit; 2942 else if (unit != n) { 2943 idr_remove(p, unit); 2944 return -EINVAL; 2945 } 2946 2947 return unit; 2948 } 2949 2950 /* get new free unit number and associate pointer with it */ 2951 static int unit_get(struct idr *p, void *ptr) 2952 { 2953 return __unit_alloc(p, ptr, 0); 2954 } 2955 2956 /* put unit number back to a pool */ 2957 static void unit_put(struct idr *p, int n) 2958 { 2959 idr_remove(p, n); 2960 } 2961 2962 /* get pointer associated with the number */ 2963 static void *unit_find(struct idr *p, int n) 2964 { 2965 return idr_find(p, n); 2966 } 2967 2968 /* Module/initialization stuff */ 2969 2970 module_init(ppp_init); 2971 module_exit(ppp_cleanup); 2972 2973 EXPORT_SYMBOL(ppp_register_net_channel); 2974 EXPORT_SYMBOL(ppp_register_channel); 2975 EXPORT_SYMBOL(ppp_unregister_channel); 2976 EXPORT_SYMBOL(ppp_channel_index); 2977 EXPORT_SYMBOL(ppp_unit_number); 2978 EXPORT_SYMBOL(ppp_dev_name); 2979 EXPORT_SYMBOL(ppp_input); 2980 EXPORT_SYMBOL(ppp_input_error); 2981 EXPORT_SYMBOL(ppp_output_wakeup); 2982 EXPORT_SYMBOL(ppp_register_compressor); 2983 EXPORT_SYMBOL(ppp_unregister_compressor); 2984 MODULE_LICENSE("GPL"); 2985 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0); 2986 MODULE_ALIAS("devname:ppp"); 2987