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 to hold primary network stats for which 98 * we want to use 64 bit storage. Other network stats 99 * are stored in dev->stats of the ppp strucute. 100 */ 101 struct ppp_link_stats { 102 u64 rx_packets; 103 u64 tx_packets; 104 u64 rx_bytes; 105 u64 tx_bytes; 106 }; 107 108 /* 109 * Data structure describing one ppp unit. 110 * A ppp unit corresponds to a ppp network interface device 111 * and represents a multilink bundle. 112 * It can have 0 or more ppp channels connected to it. 113 */ 114 struct ppp { 115 struct ppp_file file; /* stuff for read/write/poll 0 */ 116 struct file *owner; /* file that owns this unit 48 */ 117 struct list_head channels; /* list of attached channels 4c */ 118 int n_channels; /* how many channels are attached 54 */ 119 spinlock_t rlock; /* lock for receive side 58 */ 120 spinlock_t wlock; /* lock for transmit side 5c */ 121 int mru; /* max receive unit 60 */ 122 unsigned int flags; /* control bits 64 */ 123 unsigned int xstate; /* transmit state bits 68 */ 124 unsigned int rstate; /* receive state bits 6c */ 125 int debug; /* debug flags 70 */ 126 struct slcompress *vj; /* state for VJ header compression */ 127 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */ 128 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */ 129 struct compressor *xcomp; /* transmit packet compressor 8c */ 130 void *xc_state; /* its internal state 90 */ 131 struct compressor *rcomp; /* receive decompressor 94 */ 132 void *rc_state; /* its internal state 98 */ 133 unsigned long last_xmit; /* jiffies when last pkt sent 9c */ 134 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */ 135 struct net_device *dev; /* network interface device a4 */ 136 int closing; /* is device closing down? a8 */ 137 #ifdef CONFIG_PPP_MULTILINK 138 int nxchan; /* next channel to send something on */ 139 u32 nxseq; /* next sequence number to send */ 140 int mrru; /* MP: max reconst. receive unit */ 141 u32 nextseq; /* MP: seq no of next packet */ 142 u32 minseq; /* MP: min of most recent seqnos */ 143 struct sk_buff_head mrq; /* MP: receive reconstruction queue */ 144 #endif /* CONFIG_PPP_MULTILINK */ 145 #ifdef CONFIG_PPP_FILTER 146 struct sk_filter *pass_filter; /* filter for packets to pass */ 147 struct sk_filter *active_filter;/* filter for pkts to reset idle */ 148 #endif /* CONFIG_PPP_FILTER */ 149 struct net *ppp_net; /* the net we belong to */ 150 struct ppp_link_stats stats64; /* 64 bit network stats */ 151 }; 152 153 /* 154 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC, 155 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP, 156 * SC_MUST_COMP 157 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR. 158 * Bits in xstate: SC_COMP_RUN 159 */ 160 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \ 161 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \ 162 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP) 163 164 /* 165 * Private data structure for each channel. 166 * This includes the data structure used for multilink. 167 */ 168 struct channel { 169 struct ppp_file file; /* stuff for read/write/poll */ 170 struct list_head list; /* link in all/new_channels list */ 171 struct ppp_channel *chan; /* public channel data structure */ 172 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */ 173 spinlock_t downl; /* protects `chan', file.xq dequeue */ 174 struct ppp *ppp; /* ppp unit we're connected to */ 175 struct net *chan_net; /* the net channel belongs to */ 176 struct list_head clist; /* link in list of channels per unit */ 177 rwlock_t upl; /* protects `ppp' */ 178 #ifdef CONFIG_PPP_MULTILINK 179 u8 avail; /* flag used in multilink stuff */ 180 u8 had_frag; /* >= 1 fragments have been sent */ 181 u32 lastseq; /* MP: last sequence # received */ 182 int speed; /* speed of the corresponding ppp channel*/ 183 #endif /* CONFIG_PPP_MULTILINK */ 184 }; 185 186 /* 187 * SMP locking issues: 188 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels 189 * list and the ppp.n_channels field, you need to take both locks 190 * before you modify them. 191 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock -> 192 * channel.downl. 193 */ 194 195 static DEFINE_MUTEX(ppp_mutex); 196 static atomic_t ppp_unit_count = ATOMIC_INIT(0); 197 static atomic_t channel_count = ATOMIC_INIT(0); 198 199 /* per-net private data for this module */ 200 static int ppp_net_id __read_mostly; 201 struct ppp_net { 202 /* units to ppp mapping */ 203 struct idr units_idr; 204 205 /* 206 * all_ppp_mutex protects the units_idr mapping. 207 * It also ensures that finding a ppp unit in the units_idr 208 * map and updating its file.refcnt field is atomic. 209 */ 210 struct mutex all_ppp_mutex; 211 212 /* channels */ 213 struct list_head all_channels; 214 struct list_head new_channels; 215 int last_channel_index; 216 217 /* 218 * all_channels_lock protects all_channels and 219 * last_channel_index, and the atomicity of find 220 * a channel and updating its file.refcnt field. 221 */ 222 spinlock_t all_channels_lock; 223 }; 224 225 /* Get the PPP protocol number from a skb */ 226 #define PPP_PROTO(skb) get_unaligned_be16((skb)->data) 227 228 /* We limit the length of ppp->file.rq to this (arbitrary) value */ 229 #define PPP_MAX_RQLEN 32 230 231 /* 232 * Maximum number of multilink fragments queued up. 233 * This has to be large enough to cope with the maximum latency of 234 * the slowest channel relative to the others. Strictly it should 235 * depend on the number of channels and their characteristics. 236 */ 237 #define PPP_MP_MAX_QLEN 128 238 239 /* Multilink header bits. */ 240 #define B 0x80 /* this fragment begins a packet */ 241 #define E 0x40 /* this fragment ends a packet */ 242 243 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */ 244 #define seq_before(a, b) ((s32)((a) - (b)) < 0) 245 #define seq_after(a, b) ((s32)((a) - (b)) > 0) 246 247 /* Prototypes. */ 248 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 249 struct file *file, unsigned int cmd, unsigned long arg); 250 static void ppp_xmit_process(struct ppp *ppp); 251 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb); 252 static void ppp_push(struct ppp *ppp); 253 static void ppp_channel_push(struct channel *pch); 254 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, 255 struct channel *pch); 256 static void ppp_receive_error(struct ppp *ppp); 257 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb); 258 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp, 259 struct sk_buff *skb); 260 #ifdef CONFIG_PPP_MULTILINK 261 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, 262 struct channel *pch); 263 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb); 264 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp); 265 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb); 266 #endif /* CONFIG_PPP_MULTILINK */ 267 static int ppp_set_compress(struct ppp *ppp, unsigned long arg); 268 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound); 269 static void ppp_ccp_closed(struct ppp *ppp); 270 static struct compressor *find_compressor(int type); 271 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st); 272 static struct ppp *ppp_create_interface(struct net *net, int unit, int *retp); 273 static void init_ppp_file(struct ppp_file *pf, int kind); 274 static void ppp_shutdown_interface(struct ppp *ppp); 275 static void ppp_destroy_interface(struct ppp *ppp); 276 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit); 277 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit); 278 static int ppp_connect_channel(struct channel *pch, int unit); 279 static int ppp_disconnect_channel(struct channel *pch); 280 static void ppp_destroy_channel(struct channel *pch); 281 static int unit_get(struct idr *p, void *ptr); 282 static int unit_set(struct idr *p, void *ptr, int n); 283 static void unit_put(struct idr *p, int n); 284 static void *unit_find(struct idr *p, int n); 285 286 static struct class *ppp_class; 287 288 /* per net-namespace data */ 289 static inline struct ppp_net *ppp_pernet(struct net *net) 290 { 291 BUG_ON(!net); 292 293 return net_generic(net, ppp_net_id); 294 } 295 296 /* Translates a PPP protocol number to a NP index (NP == network protocol) */ 297 static inline int proto_to_npindex(int proto) 298 { 299 switch (proto) { 300 case PPP_IP: 301 return NP_IP; 302 case PPP_IPV6: 303 return NP_IPV6; 304 case PPP_IPX: 305 return NP_IPX; 306 case PPP_AT: 307 return NP_AT; 308 case PPP_MPLS_UC: 309 return NP_MPLS_UC; 310 case PPP_MPLS_MC: 311 return NP_MPLS_MC; 312 } 313 return -EINVAL; 314 } 315 316 /* Translates an NP index into a PPP protocol number */ 317 static const int npindex_to_proto[NUM_NP] = { 318 PPP_IP, 319 PPP_IPV6, 320 PPP_IPX, 321 PPP_AT, 322 PPP_MPLS_UC, 323 PPP_MPLS_MC, 324 }; 325 326 /* Translates an ethertype into an NP index */ 327 static inline int ethertype_to_npindex(int ethertype) 328 { 329 switch (ethertype) { 330 case ETH_P_IP: 331 return NP_IP; 332 case ETH_P_IPV6: 333 return NP_IPV6; 334 case ETH_P_IPX: 335 return NP_IPX; 336 case ETH_P_PPPTALK: 337 case ETH_P_ATALK: 338 return NP_AT; 339 case ETH_P_MPLS_UC: 340 return NP_MPLS_UC; 341 case ETH_P_MPLS_MC: 342 return NP_MPLS_MC; 343 } 344 return -1; 345 } 346 347 /* Translates an NP index into an ethertype */ 348 static const int npindex_to_ethertype[NUM_NP] = { 349 ETH_P_IP, 350 ETH_P_IPV6, 351 ETH_P_IPX, 352 ETH_P_PPPTALK, 353 ETH_P_MPLS_UC, 354 ETH_P_MPLS_MC, 355 }; 356 357 /* 358 * Locking shorthand. 359 */ 360 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock) 361 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock) 362 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock) 363 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock) 364 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \ 365 ppp_recv_lock(ppp); } while (0) 366 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \ 367 ppp_xmit_unlock(ppp); } while (0) 368 369 /* 370 * /dev/ppp device routines. 371 * The /dev/ppp device is used by pppd to control the ppp unit. 372 * It supports the read, write, ioctl and poll functions. 373 * Open instances of /dev/ppp can be in one of three states: 374 * unattached, attached to a ppp unit, or attached to a ppp channel. 375 */ 376 static int ppp_open(struct inode *inode, struct file *file) 377 { 378 /* 379 * This could (should?) be enforced by the permissions on /dev/ppp. 380 */ 381 if (!capable(CAP_NET_ADMIN)) 382 return -EPERM; 383 return 0; 384 } 385 386 static int ppp_release(struct inode *unused, struct file *file) 387 { 388 struct ppp_file *pf = file->private_data; 389 struct ppp *ppp; 390 391 if (pf) { 392 file->private_data = NULL; 393 if (pf->kind == INTERFACE) { 394 ppp = PF_TO_PPP(pf); 395 if (file == ppp->owner) 396 ppp_shutdown_interface(ppp); 397 } 398 if (atomic_dec_and_test(&pf->refcnt)) { 399 switch (pf->kind) { 400 case INTERFACE: 401 ppp_destroy_interface(PF_TO_PPP(pf)); 402 break; 403 case CHANNEL: 404 ppp_destroy_channel(PF_TO_CHANNEL(pf)); 405 break; 406 } 407 } 408 } 409 return 0; 410 } 411 412 static ssize_t ppp_read(struct file *file, char __user *buf, 413 size_t count, loff_t *ppos) 414 { 415 struct ppp_file *pf = file->private_data; 416 DECLARE_WAITQUEUE(wait, current); 417 ssize_t ret; 418 struct sk_buff *skb = NULL; 419 struct iovec iov; 420 421 ret = count; 422 423 if (!pf) 424 return -ENXIO; 425 add_wait_queue(&pf->rwait, &wait); 426 for (;;) { 427 set_current_state(TASK_INTERRUPTIBLE); 428 skb = skb_dequeue(&pf->rq); 429 if (skb) 430 break; 431 ret = 0; 432 if (pf->dead) 433 break; 434 if (pf->kind == INTERFACE) { 435 /* 436 * Return 0 (EOF) on an interface that has no 437 * channels connected, unless it is looping 438 * network traffic (demand mode). 439 */ 440 struct ppp *ppp = PF_TO_PPP(pf); 441 if (ppp->n_channels == 0 && 442 (ppp->flags & SC_LOOP_TRAFFIC) == 0) 443 break; 444 } 445 ret = -EAGAIN; 446 if (file->f_flags & O_NONBLOCK) 447 break; 448 ret = -ERESTARTSYS; 449 if (signal_pending(current)) 450 break; 451 schedule(); 452 } 453 set_current_state(TASK_RUNNING); 454 remove_wait_queue(&pf->rwait, &wait); 455 456 if (!skb) 457 goto out; 458 459 ret = -EOVERFLOW; 460 if (skb->len > count) 461 goto outf; 462 ret = -EFAULT; 463 iov.iov_base = buf; 464 iov.iov_len = count; 465 if (skb_copy_datagram_iovec(skb, 0, &iov, skb->len)) 466 goto outf; 467 ret = skb->len; 468 469 outf: 470 kfree_skb(skb); 471 out: 472 return ret; 473 } 474 475 static ssize_t ppp_write(struct file *file, const char __user *buf, 476 size_t count, loff_t *ppos) 477 { 478 struct ppp_file *pf = file->private_data; 479 struct sk_buff *skb; 480 ssize_t ret; 481 482 if (!pf) 483 return -ENXIO; 484 ret = -ENOMEM; 485 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL); 486 if (!skb) 487 goto out; 488 skb_reserve(skb, pf->hdrlen); 489 ret = -EFAULT; 490 if (copy_from_user(skb_put(skb, count), buf, count)) { 491 kfree_skb(skb); 492 goto out; 493 } 494 495 skb_queue_tail(&pf->xq, skb); 496 497 switch (pf->kind) { 498 case INTERFACE: 499 ppp_xmit_process(PF_TO_PPP(pf)); 500 break; 501 case CHANNEL: 502 ppp_channel_push(PF_TO_CHANNEL(pf)); 503 break; 504 } 505 506 ret = count; 507 508 out: 509 return ret; 510 } 511 512 /* No kernel lock - fine */ 513 static unsigned int ppp_poll(struct file *file, poll_table *wait) 514 { 515 struct ppp_file *pf = file->private_data; 516 unsigned int mask; 517 518 if (!pf) 519 return 0; 520 poll_wait(file, &pf->rwait, wait); 521 mask = POLLOUT | POLLWRNORM; 522 if (skb_peek(&pf->rq)) 523 mask |= POLLIN | POLLRDNORM; 524 if (pf->dead) 525 mask |= POLLHUP; 526 else if (pf->kind == INTERFACE) { 527 /* see comment in ppp_read */ 528 struct ppp *ppp = PF_TO_PPP(pf); 529 if (ppp->n_channels == 0 && 530 (ppp->flags & SC_LOOP_TRAFFIC) == 0) 531 mask |= POLLIN | POLLRDNORM; 532 } 533 534 return mask; 535 } 536 537 #ifdef CONFIG_PPP_FILTER 538 static int get_filter(void __user *arg, struct sock_filter **p) 539 { 540 struct sock_fprog uprog; 541 struct sock_filter *code = NULL; 542 int len, err; 543 544 if (copy_from_user(&uprog, arg, sizeof(uprog))) 545 return -EFAULT; 546 547 if (!uprog.len) { 548 *p = NULL; 549 return 0; 550 } 551 552 len = uprog.len * sizeof(struct sock_filter); 553 code = memdup_user(uprog.filter, len); 554 if (IS_ERR(code)) 555 return PTR_ERR(code); 556 557 err = sk_chk_filter(code, uprog.len); 558 if (err) { 559 kfree(code); 560 return err; 561 } 562 563 *p = code; 564 return uprog.len; 565 } 566 #endif /* CONFIG_PPP_FILTER */ 567 568 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 569 { 570 struct ppp_file *pf = file->private_data; 571 struct ppp *ppp; 572 int err = -EFAULT, val, val2, i; 573 struct ppp_idle idle; 574 struct npioctl npi; 575 int unit, cflags; 576 struct slcompress *vj; 577 void __user *argp = (void __user *)arg; 578 int __user *p = argp; 579 580 if (!pf) 581 return ppp_unattached_ioctl(current->nsproxy->net_ns, 582 pf, file, cmd, arg); 583 584 if (cmd == PPPIOCDETACH) { 585 /* 586 * We have to be careful here... if the file descriptor 587 * has been dup'd, we could have another process in the 588 * middle of a poll using the same file *, so we had 589 * better not free the interface data structures - 590 * instead we fail the ioctl. Even in this case, we 591 * shut down the interface if we are the owner of it. 592 * Actually, we should get rid of PPPIOCDETACH, userland 593 * (i.e. pppd) could achieve the same effect by closing 594 * this fd and reopening /dev/ppp. 595 */ 596 err = -EINVAL; 597 mutex_lock(&ppp_mutex); 598 if (pf->kind == INTERFACE) { 599 ppp = PF_TO_PPP(pf); 600 if (file == ppp->owner) 601 ppp_shutdown_interface(ppp); 602 } 603 if (atomic_long_read(&file->f_count) <= 2) { 604 ppp_release(NULL, file); 605 err = 0; 606 } else 607 pr_warn("PPPIOCDETACH file->f_count=%ld\n", 608 atomic_long_read(&file->f_count)); 609 mutex_unlock(&ppp_mutex); 610 return err; 611 } 612 613 if (pf->kind == CHANNEL) { 614 struct channel *pch; 615 struct ppp_channel *chan; 616 617 mutex_lock(&ppp_mutex); 618 pch = PF_TO_CHANNEL(pf); 619 620 switch (cmd) { 621 case PPPIOCCONNECT: 622 if (get_user(unit, p)) 623 break; 624 err = ppp_connect_channel(pch, unit); 625 break; 626 627 case PPPIOCDISCONN: 628 err = ppp_disconnect_channel(pch); 629 break; 630 631 default: 632 down_read(&pch->chan_sem); 633 chan = pch->chan; 634 err = -ENOTTY; 635 if (chan && chan->ops->ioctl) 636 err = chan->ops->ioctl(chan, cmd, arg); 637 up_read(&pch->chan_sem); 638 } 639 mutex_unlock(&ppp_mutex); 640 return err; 641 } 642 643 if (pf->kind != INTERFACE) { 644 /* can't happen */ 645 pr_err("PPP: not interface or channel??\n"); 646 return -EINVAL; 647 } 648 649 mutex_lock(&ppp_mutex); 650 ppp = PF_TO_PPP(pf); 651 switch (cmd) { 652 case PPPIOCSMRU: 653 if (get_user(val, p)) 654 break; 655 ppp->mru = val; 656 err = 0; 657 break; 658 659 case PPPIOCSFLAGS: 660 if (get_user(val, p)) 661 break; 662 ppp_lock(ppp); 663 cflags = ppp->flags & ~val; 664 ppp->flags = val & SC_FLAG_BITS; 665 ppp_unlock(ppp); 666 if (cflags & SC_CCP_OPEN) 667 ppp_ccp_closed(ppp); 668 err = 0; 669 break; 670 671 case PPPIOCGFLAGS: 672 val = ppp->flags | ppp->xstate | ppp->rstate; 673 if (put_user(val, p)) 674 break; 675 err = 0; 676 break; 677 678 case PPPIOCSCOMPRESS: 679 err = ppp_set_compress(ppp, arg); 680 break; 681 682 case PPPIOCGUNIT: 683 if (put_user(ppp->file.index, p)) 684 break; 685 err = 0; 686 break; 687 688 case PPPIOCSDEBUG: 689 if (get_user(val, p)) 690 break; 691 ppp->debug = val; 692 err = 0; 693 break; 694 695 case PPPIOCGDEBUG: 696 if (put_user(ppp->debug, p)) 697 break; 698 err = 0; 699 break; 700 701 case PPPIOCGIDLE: 702 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ; 703 idle.recv_idle = (jiffies - ppp->last_recv) / HZ; 704 if (copy_to_user(argp, &idle, sizeof(idle))) 705 break; 706 err = 0; 707 break; 708 709 case PPPIOCSMAXCID: 710 if (get_user(val, p)) 711 break; 712 val2 = 15; 713 if ((val >> 16) != 0) { 714 val2 = val >> 16; 715 val &= 0xffff; 716 } 717 vj = slhc_init(val2+1, val+1); 718 if (!vj) { 719 netdev_err(ppp->dev, 720 "PPP: no memory (VJ compressor)\n"); 721 err = -ENOMEM; 722 break; 723 } 724 ppp_lock(ppp); 725 if (ppp->vj) 726 slhc_free(ppp->vj); 727 ppp->vj = vj; 728 ppp_unlock(ppp); 729 err = 0; 730 break; 731 732 case PPPIOCGNPMODE: 733 case PPPIOCSNPMODE: 734 if (copy_from_user(&npi, argp, sizeof(npi))) 735 break; 736 err = proto_to_npindex(npi.protocol); 737 if (err < 0) 738 break; 739 i = err; 740 if (cmd == PPPIOCGNPMODE) { 741 err = -EFAULT; 742 npi.mode = ppp->npmode[i]; 743 if (copy_to_user(argp, &npi, sizeof(npi))) 744 break; 745 } else { 746 ppp->npmode[i] = npi.mode; 747 /* we may be able to transmit more packets now (??) */ 748 netif_wake_queue(ppp->dev); 749 } 750 err = 0; 751 break; 752 753 #ifdef CONFIG_PPP_FILTER 754 case PPPIOCSPASS: 755 { 756 struct sock_filter *code; 757 758 err = get_filter(argp, &code); 759 if (err >= 0) { 760 struct sock_fprog fprog = { 761 .len = err, 762 .filter = code, 763 }; 764 765 ppp_lock(ppp); 766 if (ppp->pass_filter) 767 sk_unattached_filter_destroy(ppp->pass_filter); 768 err = sk_unattached_filter_create(&ppp->pass_filter, 769 &fprog); 770 kfree(code); 771 ppp_unlock(ppp); 772 } 773 break; 774 } 775 case PPPIOCSACTIVE: 776 { 777 struct sock_filter *code; 778 779 err = get_filter(argp, &code); 780 if (err >= 0) { 781 struct sock_fprog fprog = { 782 .len = err, 783 .filter = code, 784 }; 785 786 ppp_lock(ppp); 787 if (ppp->active_filter) 788 sk_unattached_filter_destroy(ppp->active_filter); 789 err = sk_unattached_filter_create(&ppp->active_filter, 790 &fprog); 791 kfree(code); 792 ppp_unlock(ppp); 793 } 794 break; 795 } 796 #endif /* CONFIG_PPP_FILTER */ 797 798 #ifdef CONFIG_PPP_MULTILINK 799 case PPPIOCSMRRU: 800 if (get_user(val, p)) 801 break; 802 ppp_recv_lock(ppp); 803 ppp->mrru = val; 804 ppp_recv_unlock(ppp); 805 err = 0; 806 break; 807 #endif /* CONFIG_PPP_MULTILINK */ 808 809 default: 810 err = -ENOTTY; 811 } 812 mutex_unlock(&ppp_mutex); 813 return err; 814 } 815 816 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 817 struct file *file, unsigned int cmd, unsigned long arg) 818 { 819 int unit, err = -EFAULT; 820 struct ppp *ppp; 821 struct channel *chan; 822 struct ppp_net *pn; 823 int __user *p = (int __user *)arg; 824 825 mutex_lock(&ppp_mutex); 826 switch (cmd) { 827 case PPPIOCNEWUNIT: 828 /* Create a new ppp unit */ 829 if (get_user(unit, p)) 830 break; 831 ppp = ppp_create_interface(net, unit, &err); 832 if (!ppp) 833 break; 834 file->private_data = &ppp->file; 835 ppp->owner = file; 836 err = -EFAULT; 837 if (put_user(ppp->file.index, p)) 838 break; 839 err = 0; 840 break; 841 842 case PPPIOCATTACH: 843 /* Attach to an existing ppp unit */ 844 if (get_user(unit, p)) 845 break; 846 err = -ENXIO; 847 pn = ppp_pernet(net); 848 mutex_lock(&pn->all_ppp_mutex); 849 ppp = ppp_find_unit(pn, unit); 850 if (ppp) { 851 atomic_inc(&ppp->file.refcnt); 852 file->private_data = &ppp->file; 853 err = 0; 854 } 855 mutex_unlock(&pn->all_ppp_mutex); 856 break; 857 858 case PPPIOCATTCHAN: 859 if (get_user(unit, p)) 860 break; 861 err = -ENXIO; 862 pn = ppp_pernet(net); 863 spin_lock_bh(&pn->all_channels_lock); 864 chan = ppp_find_channel(pn, unit); 865 if (chan) { 866 atomic_inc(&chan->file.refcnt); 867 file->private_data = &chan->file; 868 err = 0; 869 } 870 spin_unlock_bh(&pn->all_channels_lock); 871 break; 872 873 default: 874 err = -ENOTTY; 875 } 876 mutex_unlock(&ppp_mutex); 877 return err; 878 } 879 880 static const struct file_operations ppp_device_fops = { 881 .owner = THIS_MODULE, 882 .read = ppp_read, 883 .write = ppp_write, 884 .poll = ppp_poll, 885 .unlocked_ioctl = ppp_ioctl, 886 .open = ppp_open, 887 .release = ppp_release, 888 .llseek = noop_llseek, 889 }; 890 891 static __net_init int ppp_init_net(struct net *net) 892 { 893 struct ppp_net *pn = net_generic(net, ppp_net_id); 894 895 idr_init(&pn->units_idr); 896 mutex_init(&pn->all_ppp_mutex); 897 898 INIT_LIST_HEAD(&pn->all_channels); 899 INIT_LIST_HEAD(&pn->new_channels); 900 901 spin_lock_init(&pn->all_channels_lock); 902 903 return 0; 904 } 905 906 static __net_exit void ppp_exit_net(struct net *net) 907 { 908 struct ppp_net *pn = net_generic(net, ppp_net_id); 909 910 idr_destroy(&pn->units_idr); 911 } 912 913 static struct pernet_operations ppp_net_ops = { 914 .init = ppp_init_net, 915 .exit = ppp_exit_net, 916 .id = &ppp_net_id, 917 .size = sizeof(struct ppp_net), 918 }; 919 920 #define PPP_MAJOR 108 921 922 /* Called at boot time if ppp is compiled into the kernel, 923 or at module load time (from init_module) if compiled as a module. */ 924 static int __init ppp_init(void) 925 { 926 int err; 927 928 pr_info("PPP generic driver version " PPP_VERSION "\n"); 929 930 err = register_pernet_device(&ppp_net_ops); 931 if (err) { 932 pr_err("failed to register PPP pernet device (%d)\n", err); 933 goto out; 934 } 935 936 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops); 937 if (err) { 938 pr_err("failed to register PPP device (%d)\n", err); 939 goto out_net; 940 } 941 942 ppp_class = class_create(THIS_MODULE, "ppp"); 943 if (IS_ERR(ppp_class)) { 944 err = PTR_ERR(ppp_class); 945 goto out_chrdev; 946 } 947 948 /* not a big deal if we fail here :-) */ 949 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp"); 950 951 return 0; 952 953 out_chrdev: 954 unregister_chrdev(PPP_MAJOR, "ppp"); 955 out_net: 956 unregister_pernet_device(&ppp_net_ops); 957 out: 958 return err; 959 } 960 961 /* 962 * Network interface unit routines. 963 */ 964 static netdev_tx_t 965 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev) 966 { 967 struct ppp *ppp = netdev_priv(dev); 968 int npi, proto; 969 unsigned char *pp; 970 971 npi = ethertype_to_npindex(ntohs(skb->protocol)); 972 if (npi < 0) 973 goto outf; 974 975 /* Drop, accept or reject the packet */ 976 switch (ppp->npmode[npi]) { 977 case NPMODE_PASS: 978 break; 979 case NPMODE_QUEUE: 980 /* it would be nice to have a way to tell the network 981 system to queue this one up for later. */ 982 goto outf; 983 case NPMODE_DROP: 984 case NPMODE_ERROR: 985 goto outf; 986 } 987 988 /* Put the 2-byte PPP protocol number on the front, 989 making sure there is room for the address and control fields. */ 990 if (skb_cow_head(skb, PPP_HDRLEN)) 991 goto outf; 992 993 pp = skb_push(skb, 2); 994 proto = npindex_to_proto[npi]; 995 put_unaligned_be16(proto, pp); 996 997 skb_queue_tail(&ppp->file.xq, skb); 998 ppp_xmit_process(ppp); 999 return NETDEV_TX_OK; 1000 1001 outf: 1002 kfree_skb(skb); 1003 ++dev->stats.tx_dropped; 1004 return NETDEV_TX_OK; 1005 } 1006 1007 static int 1008 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 1009 { 1010 struct ppp *ppp = netdev_priv(dev); 1011 int err = -EFAULT; 1012 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data; 1013 struct ppp_stats stats; 1014 struct ppp_comp_stats cstats; 1015 char *vers; 1016 1017 switch (cmd) { 1018 case SIOCGPPPSTATS: 1019 ppp_get_stats(ppp, &stats); 1020 if (copy_to_user(addr, &stats, sizeof(stats))) 1021 break; 1022 err = 0; 1023 break; 1024 1025 case SIOCGPPPCSTATS: 1026 memset(&cstats, 0, sizeof(cstats)); 1027 if (ppp->xc_state) 1028 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c); 1029 if (ppp->rc_state) 1030 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d); 1031 if (copy_to_user(addr, &cstats, sizeof(cstats))) 1032 break; 1033 err = 0; 1034 break; 1035 1036 case SIOCGPPPVER: 1037 vers = PPP_VERSION; 1038 if (copy_to_user(addr, vers, strlen(vers) + 1)) 1039 break; 1040 err = 0; 1041 break; 1042 1043 default: 1044 err = -EINVAL; 1045 } 1046 1047 return err; 1048 } 1049 1050 static struct rtnl_link_stats64* 1051 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64) 1052 { 1053 struct ppp *ppp = netdev_priv(dev); 1054 1055 ppp_recv_lock(ppp); 1056 stats64->rx_packets = ppp->stats64.rx_packets; 1057 stats64->rx_bytes = ppp->stats64.rx_bytes; 1058 ppp_recv_unlock(ppp); 1059 1060 ppp_xmit_lock(ppp); 1061 stats64->tx_packets = ppp->stats64.tx_packets; 1062 stats64->tx_bytes = ppp->stats64.tx_bytes; 1063 ppp_xmit_unlock(ppp); 1064 1065 stats64->rx_errors = dev->stats.rx_errors; 1066 stats64->tx_errors = dev->stats.tx_errors; 1067 stats64->rx_dropped = dev->stats.rx_dropped; 1068 stats64->tx_dropped = dev->stats.tx_dropped; 1069 stats64->rx_length_errors = dev->stats.rx_length_errors; 1070 1071 return stats64; 1072 } 1073 1074 static struct lock_class_key ppp_tx_busylock; 1075 static int ppp_dev_init(struct net_device *dev) 1076 { 1077 dev->qdisc_tx_busylock = &ppp_tx_busylock; 1078 return 0; 1079 } 1080 1081 static const struct net_device_ops ppp_netdev_ops = { 1082 .ndo_init = ppp_dev_init, 1083 .ndo_start_xmit = ppp_start_xmit, 1084 .ndo_do_ioctl = ppp_net_ioctl, 1085 .ndo_get_stats64 = ppp_get_stats64, 1086 }; 1087 1088 static void ppp_setup(struct net_device *dev) 1089 { 1090 dev->netdev_ops = &ppp_netdev_ops; 1091 dev->hard_header_len = PPP_HDRLEN; 1092 dev->mtu = PPP_MRU; 1093 dev->addr_len = 0; 1094 dev->tx_queue_len = 3; 1095 dev->type = ARPHRD_PPP; 1096 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 1097 dev->features |= NETIF_F_NETNS_LOCAL; 1098 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 1099 } 1100 1101 /* 1102 * Transmit-side routines. 1103 */ 1104 1105 /* 1106 * Called to do any work queued up on the transmit side 1107 * that can now be done. 1108 */ 1109 static void 1110 ppp_xmit_process(struct ppp *ppp) 1111 { 1112 struct sk_buff *skb; 1113 1114 ppp_xmit_lock(ppp); 1115 if (!ppp->closing) { 1116 ppp_push(ppp); 1117 while (!ppp->xmit_pending && 1118 (skb = skb_dequeue(&ppp->file.xq))) 1119 ppp_send_frame(ppp, skb); 1120 /* If there's no work left to do, tell the core net 1121 code that we can accept some more. */ 1122 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq)) 1123 netif_wake_queue(ppp->dev); 1124 else 1125 netif_stop_queue(ppp->dev); 1126 } 1127 ppp_xmit_unlock(ppp); 1128 } 1129 1130 static inline struct sk_buff * 1131 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) 1132 { 1133 struct sk_buff *new_skb; 1134 int len; 1135 int new_skb_size = ppp->dev->mtu + 1136 ppp->xcomp->comp_extra + ppp->dev->hard_header_len; 1137 int compressor_skb_size = ppp->dev->mtu + 1138 ppp->xcomp->comp_extra + PPP_HDRLEN; 1139 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC); 1140 if (!new_skb) { 1141 if (net_ratelimit()) 1142 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n"); 1143 return NULL; 1144 } 1145 if (ppp->dev->hard_header_len > PPP_HDRLEN) 1146 skb_reserve(new_skb, 1147 ppp->dev->hard_header_len - PPP_HDRLEN); 1148 1149 /* compressor still expects A/C bytes in hdr */ 1150 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, 1151 new_skb->data, skb->len + 2, 1152 compressor_skb_size); 1153 if (len > 0 && (ppp->flags & SC_CCP_UP)) { 1154 consume_skb(skb); 1155 skb = new_skb; 1156 skb_put(skb, len); 1157 skb_pull(skb, 2); /* pull off A/C bytes */ 1158 } else if (len == 0) { 1159 /* didn't compress, or CCP not up yet */ 1160 consume_skb(new_skb); 1161 new_skb = skb; 1162 } else { 1163 /* 1164 * (len < 0) 1165 * MPPE requires that we do not send unencrypted 1166 * frames. The compressor will return -1 if we 1167 * should drop the frame. We cannot simply test 1168 * the compress_proto because MPPE and MPPC share 1169 * the same number. 1170 */ 1171 if (net_ratelimit()) 1172 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n"); 1173 kfree_skb(skb); 1174 consume_skb(new_skb); 1175 new_skb = NULL; 1176 } 1177 return new_skb; 1178 } 1179 1180 /* 1181 * Compress and send a frame. 1182 * The caller should have locked the xmit path, 1183 * and xmit_pending should be 0. 1184 */ 1185 static void 1186 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) 1187 { 1188 int proto = PPP_PROTO(skb); 1189 struct sk_buff *new_skb; 1190 int len; 1191 unsigned char *cp; 1192 1193 if (proto < 0x8000) { 1194 #ifdef CONFIG_PPP_FILTER 1195 /* check if we should pass this packet */ 1196 /* the filter instructions are constructed assuming 1197 a four-byte PPP header on each packet */ 1198 *skb_push(skb, 2) = 1; 1199 if (ppp->pass_filter && 1200 SK_RUN_FILTER(ppp->pass_filter, skb) == 0) { 1201 if (ppp->debug & 1) 1202 netdev_printk(KERN_DEBUG, ppp->dev, 1203 "PPP: outbound frame " 1204 "not passed\n"); 1205 kfree_skb(skb); 1206 return; 1207 } 1208 /* if this packet passes the active filter, record the time */ 1209 if (!(ppp->active_filter && 1210 SK_RUN_FILTER(ppp->active_filter, skb) == 0)) 1211 ppp->last_xmit = jiffies; 1212 skb_pull(skb, 2); 1213 #else 1214 /* for data packets, record the time */ 1215 ppp->last_xmit = jiffies; 1216 #endif /* CONFIG_PPP_FILTER */ 1217 } 1218 1219 ++ppp->stats64.tx_packets; 1220 ppp->stats64.tx_bytes += skb->len - 2; 1221 1222 switch (proto) { 1223 case PPP_IP: 1224 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0) 1225 break; 1226 /* try to do VJ TCP header compression */ 1227 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2, 1228 GFP_ATOMIC); 1229 if (!new_skb) { 1230 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n"); 1231 goto drop; 1232 } 1233 skb_reserve(new_skb, ppp->dev->hard_header_len - 2); 1234 cp = skb->data + 2; 1235 len = slhc_compress(ppp->vj, cp, skb->len - 2, 1236 new_skb->data + 2, &cp, 1237 !(ppp->flags & SC_NO_TCP_CCID)); 1238 if (cp == skb->data + 2) { 1239 /* didn't compress */ 1240 consume_skb(new_skb); 1241 } else { 1242 if (cp[0] & SL_TYPE_COMPRESSED_TCP) { 1243 proto = PPP_VJC_COMP; 1244 cp[0] &= ~SL_TYPE_COMPRESSED_TCP; 1245 } else { 1246 proto = PPP_VJC_UNCOMP; 1247 cp[0] = skb->data[2]; 1248 } 1249 consume_skb(skb); 1250 skb = new_skb; 1251 cp = skb_put(skb, len + 2); 1252 cp[0] = 0; 1253 cp[1] = proto; 1254 } 1255 break; 1256 1257 case PPP_CCP: 1258 /* peek at outbound CCP frames */ 1259 ppp_ccp_peek(ppp, skb, 0); 1260 break; 1261 } 1262 1263 /* try to do packet compression */ 1264 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state && 1265 proto != PPP_LCP && proto != PPP_CCP) { 1266 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) { 1267 if (net_ratelimit()) 1268 netdev_err(ppp->dev, 1269 "ppp: compression required but " 1270 "down - pkt dropped.\n"); 1271 goto drop; 1272 } 1273 skb = pad_compress_skb(ppp, skb); 1274 if (!skb) 1275 goto drop; 1276 } 1277 1278 /* 1279 * If we are waiting for traffic (demand dialling), 1280 * queue it up for pppd to receive. 1281 */ 1282 if (ppp->flags & SC_LOOP_TRAFFIC) { 1283 if (ppp->file.rq.qlen > PPP_MAX_RQLEN) 1284 goto drop; 1285 skb_queue_tail(&ppp->file.rq, skb); 1286 wake_up_interruptible(&ppp->file.rwait); 1287 return; 1288 } 1289 1290 ppp->xmit_pending = skb; 1291 ppp_push(ppp); 1292 return; 1293 1294 drop: 1295 kfree_skb(skb); 1296 ++ppp->dev->stats.tx_errors; 1297 } 1298 1299 /* 1300 * Try to send the frame in xmit_pending. 1301 * The caller should have the xmit path locked. 1302 */ 1303 static void 1304 ppp_push(struct ppp *ppp) 1305 { 1306 struct list_head *list; 1307 struct channel *pch; 1308 struct sk_buff *skb = ppp->xmit_pending; 1309 1310 if (!skb) 1311 return; 1312 1313 list = &ppp->channels; 1314 if (list_empty(list)) { 1315 /* nowhere to send the packet, just drop it */ 1316 ppp->xmit_pending = NULL; 1317 kfree_skb(skb); 1318 return; 1319 } 1320 1321 if ((ppp->flags & SC_MULTILINK) == 0) { 1322 /* not doing multilink: send it down the first channel */ 1323 list = list->next; 1324 pch = list_entry(list, struct channel, clist); 1325 1326 spin_lock_bh(&pch->downl); 1327 if (pch->chan) { 1328 if (pch->chan->ops->start_xmit(pch->chan, skb)) 1329 ppp->xmit_pending = NULL; 1330 } else { 1331 /* channel got unregistered */ 1332 kfree_skb(skb); 1333 ppp->xmit_pending = NULL; 1334 } 1335 spin_unlock_bh(&pch->downl); 1336 return; 1337 } 1338 1339 #ifdef CONFIG_PPP_MULTILINK 1340 /* Multilink: fragment the packet over as many links 1341 as can take the packet at the moment. */ 1342 if (!ppp_mp_explode(ppp, skb)) 1343 return; 1344 #endif /* CONFIG_PPP_MULTILINK */ 1345 1346 ppp->xmit_pending = NULL; 1347 kfree_skb(skb); 1348 } 1349 1350 #ifdef CONFIG_PPP_MULTILINK 1351 static bool mp_protocol_compress __read_mostly = true; 1352 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR); 1353 MODULE_PARM_DESC(mp_protocol_compress, 1354 "compress protocol id in multilink fragments"); 1355 1356 /* 1357 * Divide a packet to be transmitted into fragments and 1358 * send them out the individual links. 1359 */ 1360 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb) 1361 { 1362 int len, totlen; 1363 int i, bits, hdrlen, mtu; 1364 int flen; 1365 int navail, nfree, nzero; 1366 int nbigger; 1367 int totspeed; 1368 int totfree; 1369 unsigned char *p, *q; 1370 struct list_head *list; 1371 struct channel *pch; 1372 struct sk_buff *frag; 1373 struct ppp_channel *chan; 1374 1375 totspeed = 0; /*total bitrate of the bundle*/ 1376 nfree = 0; /* # channels which have no packet already queued */ 1377 navail = 0; /* total # of usable channels (not deregistered) */ 1378 nzero = 0; /* number of channels with zero speed associated*/ 1379 totfree = 0; /*total # of channels available and 1380 *having no queued packets before 1381 *starting the fragmentation*/ 1382 1383 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1384 i = 0; 1385 list_for_each_entry(pch, &ppp->channels, clist) { 1386 if (pch->chan) { 1387 pch->avail = 1; 1388 navail++; 1389 pch->speed = pch->chan->speed; 1390 } else { 1391 pch->avail = 0; 1392 } 1393 if (pch->avail) { 1394 if (skb_queue_empty(&pch->file.xq) || 1395 !pch->had_frag) { 1396 if (pch->speed == 0) 1397 nzero++; 1398 else 1399 totspeed += pch->speed; 1400 1401 pch->avail = 2; 1402 ++nfree; 1403 ++totfree; 1404 } 1405 if (!pch->had_frag && i < ppp->nxchan) 1406 ppp->nxchan = i; 1407 } 1408 ++i; 1409 } 1410 /* 1411 * Don't start sending this packet unless at least half of 1412 * the channels are free. This gives much better TCP 1413 * performance if we have a lot of channels. 1414 */ 1415 if (nfree == 0 || nfree < navail / 2) 1416 return 0; /* can't take now, leave it in xmit_pending */ 1417 1418 /* Do protocol field compression */ 1419 p = skb->data; 1420 len = skb->len; 1421 if (*p == 0 && mp_protocol_compress) { 1422 ++p; 1423 --len; 1424 } 1425 1426 totlen = len; 1427 nbigger = len % nfree; 1428 1429 /* skip to the channel after the one we last used 1430 and start at that one */ 1431 list = &ppp->channels; 1432 for (i = 0; i < ppp->nxchan; ++i) { 1433 list = list->next; 1434 if (list == &ppp->channels) { 1435 i = 0; 1436 break; 1437 } 1438 } 1439 1440 /* create a fragment for each channel */ 1441 bits = B; 1442 while (len > 0) { 1443 list = list->next; 1444 if (list == &ppp->channels) { 1445 i = 0; 1446 continue; 1447 } 1448 pch = list_entry(list, struct channel, clist); 1449 ++i; 1450 if (!pch->avail) 1451 continue; 1452 1453 /* 1454 * Skip this channel if it has a fragment pending already and 1455 * we haven't given a fragment to all of the free channels. 1456 */ 1457 if (pch->avail == 1) { 1458 if (nfree > 0) 1459 continue; 1460 } else { 1461 pch->avail = 1; 1462 } 1463 1464 /* check the channel's mtu and whether it is still attached. */ 1465 spin_lock_bh(&pch->downl); 1466 if (pch->chan == NULL) { 1467 /* can't use this channel, it's being deregistered */ 1468 if (pch->speed == 0) 1469 nzero--; 1470 else 1471 totspeed -= pch->speed; 1472 1473 spin_unlock_bh(&pch->downl); 1474 pch->avail = 0; 1475 totlen = len; 1476 totfree--; 1477 nfree--; 1478 if (--navail == 0) 1479 break; 1480 continue; 1481 } 1482 1483 /* 1484 *if the channel speed is not set divide 1485 *the packet evenly among the free channels; 1486 *otherwise divide it according to the speed 1487 *of the channel we are going to transmit on 1488 */ 1489 flen = len; 1490 if (nfree > 0) { 1491 if (pch->speed == 0) { 1492 flen = len/nfree; 1493 if (nbigger > 0) { 1494 flen++; 1495 nbigger--; 1496 } 1497 } else { 1498 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) / 1499 ((totspeed*totfree)/pch->speed)) - hdrlen; 1500 if (nbigger > 0) { 1501 flen += ((totfree - nzero)*pch->speed)/totspeed; 1502 nbigger -= ((totfree - nzero)*pch->speed)/ 1503 totspeed; 1504 } 1505 } 1506 nfree--; 1507 } 1508 1509 /* 1510 *check if we are on the last channel or 1511 *we exceded the length of the data to 1512 *fragment 1513 */ 1514 if ((nfree <= 0) || (flen > len)) 1515 flen = len; 1516 /* 1517 *it is not worth to tx on slow channels: 1518 *in that case from the resulting flen according to the 1519 *above formula will be equal or less than zero. 1520 *Skip the channel in this case 1521 */ 1522 if (flen <= 0) { 1523 pch->avail = 2; 1524 spin_unlock_bh(&pch->downl); 1525 continue; 1526 } 1527 1528 /* 1529 * hdrlen includes the 2-byte PPP protocol field, but the 1530 * MTU counts only the payload excluding the protocol field. 1531 * (RFC1661 Section 2) 1532 */ 1533 mtu = pch->chan->mtu - (hdrlen - 2); 1534 if (mtu < 4) 1535 mtu = 4; 1536 if (flen > mtu) 1537 flen = mtu; 1538 if (flen == len) 1539 bits |= E; 1540 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC); 1541 if (!frag) 1542 goto noskb; 1543 q = skb_put(frag, flen + hdrlen); 1544 1545 /* make the MP header */ 1546 put_unaligned_be16(PPP_MP, q); 1547 if (ppp->flags & SC_MP_XSHORTSEQ) { 1548 q[2] = bits + ((ppp->nxseq >> 8) & 0xf); 1549 q[3] = ppp->nxseq; 1550 } else { 1551 q[2] = bits; 1552 q[3] = ppp->nxseq >> 16; 1553 q[4] = ppp->nxseq >> 8; 1554 q[5] = ppp->nxseq; 1555 } 1556 1557 memcpy(q + hdrlen, p, flen); 1558 1559 /* try to send it down the channel */ 1560 chan = pch->chan; 1561 if (!skb_queue_empty(&pch->file.xq) || 1562 !chan->ops->start_xmit(chan, frag)) 1563 skb_queue_tail(&pch->file.xq, frag); 1564 pch->had_frag = 1; 1565 p += flen; 1566 len -= flen; 1567 ++ppp->nxseq; 1568 bits = 0; 1569 spin_unlock_bh(&pch->downl); 1570 } 1571 ppp->nxchan = i; 1572 1573 return 1; 1574 1575 noskb: 1576 spin_unlock_bh(&pch->downl); 1577 if (ppp->debug & 1) 1578 netdev_err(ppp->dev, "PPP: no memory (fragment)\n"); 1579 ++ppp->dev->stats.tx_errors; 1580 ++ppp->nxseq; 1581 return 1; /* abandon the frame */ 1582 } 1583 #endif /* CONFIG_PPP_MULTILINK */ 1584 1585 /* 1586 * Try to send data out on a channel. 1587 */ 1588 static void 1589 ppp_channel_push(struct channel *pch) 1590 { 1591 struct sk_buff *skb; 1592 struct ppp *ppp; 1593 1594 spin_lock_bh(&pch->downl); 1595 if (pch->chan) { 1596 while (!skb_queue_empty(&pch->file.xq)) { 1597 skb = skb_dequeue(&pch->file.xq); 1598 if (!pch->chan->ops->start_xmit(pch->chan, skb)) { 1599 /* put the packet back and try again later */ 1600 skb_queue_head(&pch->file.xq, skb); 1601 break; 1602 } 1603 } 1604 } else { 1605 /* channel got deregistered */ 1606 skb_queue_purge(&pch->file.xq); 1607 } 1608 spin_unlock_bh(&pch->downl); 1609 /* see if there is anything from the attached unit to be sent */ 1610 if (skb_queue_empty(&pch->file.xq)) { 1611 read_lock_bh(&pch->upl); 1612 ppp = pch->ppp; 1613 if (ppp) 1614 ppp_xmit_process(ppp); 1615 read_unlock_bh(&pch->upl); 1616 } 1617 } 1618 1619 /* 1620 * Receive-side routines. 1621 */ 1622 1623 struct ppp_mp_skb_parm { 1624 u32 sequence; 1625 u8 BEbits; 1626 }; 1627 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb)) 1628 1629 static inline void 1630 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1631 { 1632 ppp_recv_lock(ppp); 1633 if (!ppp->closing) 1634 ppp_receive_frame(ppp, skb, pch); 1635 else 1636 kfree_skb(skb); 1637 ppp_recv_unlock(ppp); 1638 } 1639 1640 void 1641 ppp_input(struct ppp_channel *chan, struct sk_buff *skb) 1642 { 1643 struct channel *pch = chan->ppp; 1644 int proto; 1645 1646 if (!pch) { 1647 kfree_skb(skb); 1648 return; 1649 } 1650 1651 read_lock_bh(&pch->upl); 1652 if (!pskb_may_pull(skb, 2)) { 1653 kfree_skb(skb); 1654 if (pch->ppp) { 1655 ++pch->ppp->dev->stats.rx_length_errors; 1656 ppp_receive_error(pch->ppp); 1657 } 1658 goto done; 1659 } 1660 1661 proto = PPP_PROTO(skb); 1662 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) { 1663 /* put it on the channel queue */ 1664 skb_queue_tail(&pch->file.rq, skb); 1665 /* drop old frames if queue too long */ 1666 while (pch->file.rq.qlen > PPP_MAX_RQLEN && 1667 (skb = skb_dequeue(&pch->file.rq))) 1668 kfree_skb(skb); 1669 wake_up_interruptible(&pch->file.rwait); 1670 } else { 1671 ppp_do_recv(pch->ppp, skb, pch); 1672 } 1673 1674 done: 1675 read_unlock_bh(&pch->upl); 1676 } 1677 1678 /* Put a 0-length skb in the receive queue as an error indication */ 1679 void 1680 ppp_input_error(struct ppp_channel *chan, int code) 1681 { 1682 struct channel *pch = chan->ppp; 1683 struct sk_buff *skb; 1684 1685 if (!pch) 1686 return; 1687 1688 read_lock_bh(&pch->upl); 1689 if (pch->ppp) { 1690 skb = alloc_skb(0, GFP_ATOMIC); 1691 if (skb) { 1692 skb->len = 0; /* probably unnecessary */ 1693 skb->cb[0] = code; 1694 ppp_do_recv(pch->ppp, skb, pch); 1695 } 1696 } 1697 read_unlock_bh(&pch->upl); 1698 } 1699 1700 /* 1701 * We come in here to process a received frame. 1702 * The receive side of the ppp unit is locked. 1703 */ 1704 static void 1705 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1706 { 1707 /* note: a 0-length skb is used as an error indication */ 1708 if (skb->len > 0) { 1709 #ifdef CONFIG_PPP_MULTILINK 1710 /* XXX do channel-level decompression here */ 1711 if (PPP_PROTO(skb) == PPP_MP) 1712 ppp_receive_mp_frame(ppp, skb, pch); 1713 else 1714 #endif /* CONFIG_PPP_MULTILINK */ 1715 ppp_receive_nonmp_frame(ppp, skb); 1716 } else { 1717 kfree_skb(skb); 1718 ppp_receive_error(ppp); 1719 } 1720 } 1721 1722 static void 1723 ppp_receive_error(struct ppp *ppp) 1724 { 1725 ++ppp->dev->stats.rx_errors; 1726 if (ppp->vj) 1727 slhc_toss(ppp->vj); 1728 } 1729 1730 static void 1731 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) 1732 { 1733 struct sk_buff *ns; 1734 int proto, len, npi; 1735 1736 /* 1737 * Decompress the frame, if compressed. 1738 * Note that some decompressors need to see uncompressed frames 1739 * that come in as well as compressed frames. 1740 */ 1741 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) && 1742 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0) 1743 skb = ppp_decompress_frame(ppp, skb); 1744 1745 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR) 1746 goto err; 1747 1748 proto = PPP_PROTO(skb); 1749 switch (proto) { 1750 case PPP_VJC_COMP: 1751 /* decompress VJ compressed packets */ 1752 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 1753 goto err; 1754 1755 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) { 1756 /* copy to a new sk_buff with more tailroom */ 1757 ns = dev_alloc_skb(skb->len + 128); 1758 if (!ns) { 1759 netdev_err(ppp->dev, "PPP: no memory " 1760 "(VJ decomp)\n"); 1761 goto err; 1762 } 1763 skb_reserve(ns, 2); 1764 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len); 1765 consume_skb(skb); 1766 skb = ns; 1767 } 1768 else 1769 skb->ip_summed = CHECKSUM_NONE; 1770 1771 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2); 1772 if (len <= 0) { 1773 netdev_printk(KERN_DEBUG, ppp->dev, 1774 "PPP: VJ decompression error\n"); 1775 goto err; 1776 } 1777 len += 2; 1778 if (len > skb->len) 1779 skb_put(skb, len - skb->len); 1780 else if (len < skb->len) 1781 skb_trim(skb, len); 1782 proto = PPP_IP; 1783 break; 1784 1785 case PPP_VJC_UNCOMP: 1786 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 1787 goto err; 1788 1789 /* Until we fix the decompressor need to make sure 1790 * data portion is linear. 1791 */ 1792 if (!pskb_may_pull(skb, skb->len)) 1793 goto err; 1794 1795 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) { 1796 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n"); 1797 goto err; 1798 } 1799 proto = PPP_IP; 1800 break; 1801 1802 case PPP_CCP: 1803 ppp_ccp_peek(ppp, skb, 1); 1804 break; 1805 } 1806 1807 ++ppp->stats64.rx_packets; 1808 ppp->stats64.rx_bytes += skb->len - 2; 1809 1810 npi = proto_to_npindex(proto); 1811 if (npi < 0) { 1812 /* control or unknown frame - pass it to pppd */ 1813 skb_queue_tail(&ppp->file.rq, skb); 1814 /* limit queue length by dropping old frames */ 1815 while (ppp->file.rq.qlen > PPP_MAX_RQLEN && 1816 (skb = skb_dequeue(&ppp->file.rq))) 1817 kfree_skb(skb); 1818 /* wake up any process polling or blocking on read */ 1819 wake_up_interruptible(&ppp->file.rwait); 1820 1821 } else { 1822 /* network protocol frame - give it to the kernel */ 1823 1824 #ifdef CONFIG_PPP_FILTER 1825 /* check if the packet passes the pass and active filters */ 1826 /* the filter instructions are constructed assuming 1827 a four-byte PPP header on each packet */ 1828 if (ppp->pass_filter || ppp->active_filter) { 1829 if (skb_unclone(skb, GFP_ATOMIC)) 1830 goto err; 1831 1832 *skb_push(skb, 2) = 0; 1833 if (ppp->pass_filter && 1834 SK_RUN_FILTER(ppp->pass_filter, skb) == 0) { 1835 if (ppp->debug & 1) 1836 netdev_printk(KERN_DEBUG, ppp->dev, 1837 "PPP: inbound frame " 1838 "not passed\n"); 1839 kfree_skb(skb); 1840 return; 1841 } 1842 if (!(ppp->active_filter && 1843 SK_RUN_FILTER(ppp->active_filter, skb) == 0)) 1844 ppp->last_recv = jiffies; 1845 __skb_pull(skb, 2); 1846 } else 1847 #endif /* CONFIG_PPP_FILTER */ 1848 ppp->last_recv = jiffies; 1849 1850 if ((ppp->dev->flags & IFF_UP) == 0 || 1851 ppp->npmode[npi] != NPMODE_PASS) { 1852 kfree_skb(skb); 1853 } else { 1854 /* chop off protocol */ 1855 skb_pull_rcsum(skb, 2); 1856 skb->dev = ppp->dev; 1857 skb->protocol = htons(npindex_to_ethertype[npi]); 1858 skb_reset_mac_header(skb); 1859 netif_rx(skb); 1860 } 1861 } 1862 return; 1863 1864 err: 1865 kfree_skb(skb); 1866 ppp_receive_error(ppp); 1867 } 1868 1869 static struct sk_buff * 1870 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb) 1871 { 1872 int proto = PPP_PROTO(skb); 1873 struct sk_buff *ns; 1874 int len; 1875 1876 /* Until we fix all the decompressor's need to make sure 1877 * data portion is linear. 1878 */ 1879 if (!pskb_may_pull(skb, skb->len)) 1880 goto err; 1881 1882 if (proto == PPP_COMP) { 1883 int obuff_size; 1884 1885 switch(ppp->rcomp->compress_proto) { 1886 case CI_MPPE: 1887 obuff_size = ppp->mru + PPP_HDRLEN + 1; 1888 break; 1889 default: 1890 obuff_size = ppp->mru + PPP_HDRLEN; 1891 break; 1892 } 1893 1894 ns = dev_alloc_skb(obuff_size); 1895 if (!ns) { 1896 netdev_err(ppp->dev, "ppp_decompress_frame: " 1897 "no memory\n"); 1898 goto err; 1899 } 1900 /* the decompressor still expects the A/C bytes in the hdr */ 1901 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2, 1902 skb->len + 2, ns->data, obuff_size); 1903 if (len < 0) { 1904 /* Pass the compressed frame to pppd as an 1905 error indication. */ 1906 if (len == DECOMP_FATALERROR) 1907 ppp->rstate |= SC_DC_FERROR; 1908 kfree_skb(ns); 1909 goto err; 1910 } 1911 1912 consume_skb(skb); 1913 skb = ns; 1914 skb_put(skb, len); 1915 skb_pull(skb, 2); /* pull off the A/C bytes */ 1916 1917 } else { 1918 /* Uncompressed frame - pass to decompressor so it 1919 can update its dictionary if necessary. */ 1920 if (ppp->rcomp->incomp) 1921 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2, 1922 skb->len + 2); 1923 } 1924 1925 return skb; 1926 1927 err: 1928 ppp->rstate |= SC_DC_ERROR; 1929 ppp_receive_error(ppp); 1930 return skb; 1931 } 1932 1933 #ifdef CONFIG_PPP_MULTILINK 1934 /* 1935 * Receive a multilink frame. 1936 * We put it on the reconstruction queue and then pull off 1937 * as many completed frames as we can. 1938 */ 1939 static void 1940 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1941 { 1942 u32 mask, seq; 1943 struct channel *ch; 1944 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1945 1946 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0) 1947 goto err; /* no good, throw it away */ 1948 1949 /* Decode sequence number and begin/end bits */ 1950 if (ppp->flags & SC_MP_SHORTSEQ) { 1951 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3]; 1952 mask = 0xfff; 1953 } else { 1954 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5]; 1955 mask = 0xffffff; 1956 } 1957 PPP_MP_CB(skb)->BEbits = skb->data[2]; 1958 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */ 1959 1960 /* 1961 * Do protocol ID decompression on the first fragment of each packet. 1962 */ 1963 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1)) 1964 *skb_push(skb, 1) = 0; 1965 1966 /* 1967 * Expand sequence number to 32 bits, making it as close 1968 * as possible to ppp->minseq. 1969 */ 1970 seq |= ppp->minseq & ~mask; 1971 if ((int)(ppp->minseq - seq) > (int)(mask >> 1)) 1972 seq += mask + 1; 1973 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1)) 1974 seq -= mask + 1; /* should never happen */ 1975 PPP_MP_CB(skb)->sequence = seq; 1976 pch->lastseq = seq; 1977 1978 /* 1979 * If this packet comes before the next one we were expecting, 1980 * drop it. 1981 */ 1982 if (seq_before(seq, ppp->nextseq)) { 1983 kfree_skb(skb); 1984 ++ppp->dev->stats.rx_dropped; 1985 ppp_receive_error(ppp); 1986 return; 1987 } 1988 1989 /* 1990 * Reevaluate minseq, the minimum over all channels of the 1991 * last sequence number received on each channel. Because of 1992 * the increasing sequence number rule, we know that any fragment 1993 * before `minseq' which hasn't arrived is never going to arrive. 1994 * The list of channels can't change because we have the receive 1995 * side of the ppp unit locked. 1996 */ 1997 list_for_each_entry(ch, &ppp->channels, clist) { 1998 if (seq_before(ch->lastseq, seq)) 1999 seq = ch->lastseq; 2000 } 2001 if (seq_before(ppp->minseq, seq)) 2002 ppp->minseq = seq; 2003 2004 /* Put the fragment on the reconstruction queue */ 2005 ppp_mp_insert(ppp, skb); 2006 2007 /* If the queue is getting long, don't wait any longer for packets 2008 before the start of the queue. */ 2009 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) { 2010 struct sk_buff *mskb = skb_peek(&ppp->mrq); 2011 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence)) 2012 ppp->minseq = PPP_MP_CB(mskb)->sequence; 2013 } 2014 2015 /* Pull completed packets off the queue and receive them. */ 2016 while ((skb = ppp_mp_reconstruct(ppp))) { 2017 if (pskb_may_pull(skb, 2)) 2018 ppp_receive_nonmp_frame(ppp, skb); 2019 else { 2020 ++ppp->dev->stats.rx_length_errors; 2021 kfree_skb(skb); 2022 ppp_receive_error(ppp); 2023 } 2024 } 2025 2026 return; 2027 2028 err: 2029 kfree_skb(skb); 2030 ppp_receive_error(ppp); 2031 } 2032 2033 /* 2034 * Insert a fragment on the MP reconstruction queue. 2035 * The queue is ordered by increasing sequence number. 2036 */ 2037 static void 2038 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb) 2039 { 2040 struct sk_buff *p; 2041 struct sk_buff_head *list = &ppp->mrq; 2042 u32 seq = PPP_MP_CB(skb)->sequence; 2043 2044 /* N.B. we don't need to lock the list lock because we have the 2045 ppp unit receive-side lock. */ 2046 skb_queue_walk(list, p) { 2047 if (seq_before(seq, PPP_MP_CB(p)->sequence)) 2048 break; 2049 } 2050 __skb_queue_before(list, p, skb); 2051 } 2052 2053 /* 2054 * Reconstruct a packet from the MP fragment queue. 2055 * We go through increasing sequence numbers until we find a 2056 * complete packet, or we get to the sequence number for a fragment 2057 * which hasn't arrived but might still do so. 2058 */ 2059 static struct sk_buff * 2060 ppp_mp_reconstruct(struct ppp *ppp) 2061 { 2062 u32 seq = ppp->nextseq; 2063 u32 minseq = ppp->minseq; 2064 struct sk_buff_head *list = &ppp->mrq; 2065 struct sk_buff *p, *tmp; 2066 struct sk_buff *head, *tail; 2067 struct sk_buff *skb = NULL; 2068 int lost = 0, len = 0; 2069 2070 if (ppp->mrru == 0) /* do nothing until mrru is set */ 2071 return NULL; 2072 head = list->next; 2073 tail = NULL; 2074 skb_queue_walk_safe(list, p, tmp) { 2075 again: 2076 if (seq_before(PPP_MP_CB(p)->sequence, seq)) { 2077 /* this can't happen, anyway ignore the skb */ 2078 netdev_err(ppp->dev, "ppp_mp_reconstruct bad " 2079 "seq %u < %u\n", 2080 PPP_MP_CB(p)->sequence, seq); 2081 __skb_unlink(p, list); 2082 kfree_skb(p); 2083 continue; 2084 } 2085 if (PPP_MP_CB(p)->sequence != seq) { 2086 u32 oldseq; 2087 /* Fragment `seq' is missing. If it is after 2088 minseq, it might arrive later, so stop here. */ 2089 if (seq_after(seq, minseq)) 2090 break; 2091 /* Fragment `seq' is lost, keep going. */ 2092 lost = 1; 2093 oldseq = seq; 2094 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)? 2095 minseq + 1: PPP_MP_CB(p)->sequence; 2096 2097 if (ppp->debug & 1) 2098 netdev_printk(KERN_DEBUG, ppp->dev, 2099 "lost frag %u..%u\n", 2100 oldseq, seq-1); 2101 2102 goto again; 2103 } 2104 2105 /* 2106 * At this point we know that all the fragments from 2107 * ppp->nextseq to seq are either present or lost. 2108 * Also, there are no complete packets in the queue 2109 * that have no missing fragments and end before this 2110 * fragment. 2111 */ 2112 2113 /* B bit set indicates this fragment starts a packet */ 2114 if (PPP_MP_CB(p)->BEbits & B) { 2115 head = p; 2116 lost = 0; 2117 len = 0; 2118 } 2119 2120 len += p->len; 2121 2122 /* Got a complete packet yet? */ 2123 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) && 2124 (PPP_MP_CB(head)->BEbits & B)) { 2125 if (len > ppp->mrru + 2) { 2126 ++ppp->dev->stats.rx_length_errors; 2127 netdev_printk(KERN_DEBUG, ppp->dev, 2128 "PPP: reconstructed packet" 2129 " is too long (%d)\n", len); 2130 } else { 2131 tail = p; 2132 break; 2133 } 2134 ppp->nextseq = seq + 1; 2135 } 2136 2137 /* 2138 * If this is the ending fragment of a packet, 2139 * and we haven't found a complete valid packet yet, 2140 * we can discard up to and including this fragment. 2141 */ 2142 if (PPP_MP_CB(p)->BEbits & E) { 2143 struct sk_buff *tmp2; 2144 2145 skb_queue_reverse_walk_from_safe(list, p, tmp2) { 2146 if (ppp->debug & 1) 2147 netdev_printk(KERN_DEBUG, ppp->dev, 2148 "discarding frag %u\n", 2149 PPP_MP_CB(p)->sequence); 2150 __skb_unlink(p, list); 2151 kfree_skb(p); 2152 } 2153 head = skb_peek(list); 2154 if (!head) 2155 break; 2156 } 2157 ++seq; 2158 } 2159 2160 /* If we have a complete packet, copy it all into one skb. */ 2161 if (tail != NULL) { 2162 /* If we have discarded any fragments, 2163 signal a receive error. */ 2164 if (PPP_MP_CB(head)->sequence != ppp->nextseq) { 2165 skb_queue_walk_safe(list, p, tmp) { 2166 if (p == head) 2167 break; 2168 if (ppp->debug & 1) 2169 netdev_printk(KERN_DEBUG, ppp->dev, 2170 "discarding frag %u\n", 2171 PPP_MP_CB(p)->sequence); 2172 __skb_unlink(p, list); 2173 kfree_skb(p); 2174 } 2175 2176 if (ppp->debug & 1) 2177 netdev_printk(KERN_DEBUG, ppp->dev, 2178 " missed pkts %u..%u\n", 2179 ppp->nextseq, 2180 PPP_MP_CB(head)->sequence-1); 2181 ++ppp->dev->stats.rx_dropped; 2182 ppp_receive_error(ppp); 2183 } 2184 2185 skb = head; 2186 if (head != tail) { 2187 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list; 2188 p = skb_queue_next(list, head); 2189 __skb_unlink(skb, list); 2190 skb_queue_walk_from_safe(list, p, tmp) { 2191 __skb_unlink(p, list); 2192 *fragpp = p; 2193 p->next = NULL; 2194 fragpp = &p->next; 2195 2196 skb->len += p->len; 2197 skb->data_len += p->len; 2198 skb->truesize += p->truesize; 2199 2200 if (p == tail) 2201 break; 2202 } 2203 } else { 2204 __skb_unlink(skb, list); 2205 } 2206 2207 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1; 2208 } 2209 2210 return skb; 2211 } 2212 #endif /* CONFIG_PPP_MULTILINK */ 2213 2214 /* 2215 * Channel interface. 2216 */ 2217 2218 /* Create a new, unattached ppp channel. */ 2219 int ppp_register_channel(struct ppp_channel *chan) 2220 { 2221 return ppp_register_net_channel(current->nsproxy->net_ns, chan); 2222 } 2223 2224 /* Create a new, unattached ppp channel for specified net. */ 2225 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan) 2226 { 2227 struct channel *pch; 2228 struct ppp_net *pn; 2229 2230 pch = kzalloc(sizeof(struct channel), GFP_KERNEL); 2231 if (!pch) 2232 return -ENOMEM; 2233 2234 pn = ppp_pernet(net); 2235 2236 pch->ppp = NULL; 2237 pch->chan = chan; 2238 pch->chan_net = net; 2239 chan->ppp = pch; 2240 init_ppp_file(&pch->file, CHANNEL); 2241 pch->file.hdrlen = chan->hdrlen; 2242 #ifdef CONFIG_PPP_MULTILINK 2243 pch->lastseq = -1; 2244 #endif /* CONFIG_PPP_MULTILINK */ 2245 init_rwsem(&pch->chan_sem); 2246 spin_lock_init(&pch->downl); 2247 rwlock_init(&pch->upl); 2248 2249 spin_lock_bh(&pn->all_channels_lock); 2250 pch->file.index = ++pn->last_channel_index; 2251 list_add(&pch->list, &pn->new_channels); 2252 atomic_inc(&channel_count); 2253 spin_unlock_bh(&pn->all_channels_lock); 2254 2255 return 0; 2256 } 2257 2258 /* 2259 * Return the index of a channel. 2260 */ 2261 int ppp_channel_index(struct ppp_channel *chan) 2262 { 2263 struct channel *pch = chan->ppp; 2264 2265 if (pch) 2266 return pch->file.index; 2267 return -1; 2268 } 2269 2270 /* 2271 * Return the PPP unit number to which a channel is connected. 2272 */ 2273 int ppp_unit_number(struct ppp_channel *chan) 2274 { 2275 struct channel *pch = chan->ppp; 2276 int unit = -1; 2277 2278 if (pch) { 2279 read_lock_bh(&pch->upl); 2280 if (pch->ppp) 2281 unit = pch->ppp->file.index; 2282 read_unlock_bh(&pch->upl); 2283 } 2284 return unit; 2285 } 2286 2287 /* 2288 * Return the PPP device interface name of a channel. 2289 */ 2290 char *ppp_dev_name(struct ppp_channel *chan) 2291 { 2292 struct channel *pch = chan->ppp; 2293 char *name = NULL; 2294 2295 if (pch) { 2296 read_lock_bh(&pch->upl); 2297 if (pch->ppp && pch->ppp->dev) 2298 name = pch->ppp->dev->name; 2299 read_unlock_bh(&pch->upl); 2300 } 2301 return name; 2302 } 2303 2304 2305 /* 2306 * Disconnect a channel from the generic layer. 2307 * This must be called in process context. 2308 */ 2309 void 2310 ppp_unregister_channel(struct ppp_channel *chan) 2311 { 2312 struct channel *pch = chan->ppp; 2313 struct ppp_net *pn; 2314 2315 if (!pch) 2316 return; /* should never happen */ 2317 2318 chan->ppp = NULL; 2319 2320 /* 2321 * This ensures that we have returned from any calls into the 2322 * the channel's start_xmit or ioctl routine before we proceed. 2323 */ 2324 down_write(&pch->chan_sem); 2325 spin_lock_bh(&pch->downl); 2326 pch->chan = NULL; 2327 spin_unlock_bh(&pch->downl); 2328 up_write(&pch->chan_sem); 2329 ppp_disconnect_channel(pch); 2330 2331 pn = ppp_pernet(pch->chan_net); 2332 spin_lock_bh(&pn->all_channels_lock); 2333 list_del(&pch->list); 2334 spin_unlock_bh(&pn->all_channels_lock); 2335 2336 pch->file.dead = 1; 2337 wake_up_interruptible(&pch->file.rwait); 2338 if (atomic_dec_and_test(&pch->file.refcnt)) 2339 ppp_destroy_channel(pch); 2340 } 2341 2342 /* 2343 * Callback from a channel when it can accept more to transmit. 2344 * This should be called at BH/softirq level, not interrupt level. 2345 */ 2346 void 2347 ppp_output_wakeup(struct ppp_channel *chan) 2348 { 2349 struct channel *pch = chan->ppp; 2350 2351 if (!pch) 2352 return; 2353 ppp_channel_push(pch); 2354 } 2355 2356 /* 2357 * Compression control. 2358 */ 2359 2360 /* Process the PPPIOCSCOMPRESS ioctl. */ 2361 static int 2362 ppp_set_compress(struct ppp *ppp, unsigned long arg) 2363 { 2364 int err; 2365 struct compressor *cp, *ocomp; 2366 struct ppp_option_data data; 2367 void *state, *ostate; 2368 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH]; 2369 2370 err = -EFAULT; 2371 if (copy_from_user(&data, (void __user *) arg, sizeof(data)) || 2372 (data.length <= CCP_MAX_OPTION_LENGTH && 2373 copy_from_user(ccp_option, (void __user *) data.ptr, data.length))) 2374 goto out; 2375 err = -EINVAL; 2376 if (data.length > CCP_MAX_OPTION_LENGTH || 2377 ccp_option[1] < 2 || ccp_option[1] > data.length) 2378 goto out; 2379 2380 cp = try_then_request_module( 2381 find_compressor(ccp_option[0]), 2382 "ppp-compress-%d", ccp_option[0]); 2383 if (!cp) 2384 goto out; 2385 2386 err = -ENOBUFS; 2387 if (data.transmit) { 2388 state = cp->comp_alloc(ccp_option, data.length); 2389 if (state) { 2390 ppp_xmit_lock(ppp); 2391 ppp->xstate &= ~SC_COMP_RUN; 2392 ocomp = ppp->xcomp; 2393 ostate = ppp->xc_state; 2394 ppp->xcomp = cp; 2395 ppp->xc_state = state; 2396 ppp_xmit_unlock(ppp); 2397 if (ostate) { 2398 ocomp->comp_free(ostate); 2399 module_put(ocomp->owner); 2400 } 2401 err = 0; 2402 } else 2403 module_put(cp->owner); 2404 2405 } else { 2406 state = cp->decomp_alloc(ccp_option, data.length); 2407 if (state) { 2408 ppp_recv_lock(ppp); 2409 ppp->rstate &= ~SC_DECOMP_RUN; 2410 ocomp = ppp->rcomp; 2411 ostate = ppp->rc_state; 2412 ppp->rcomp = cp; 2413 ppp->rc_state = state; 2414 ppp_recv_unlock(ppp); 2415 if (ostate) { 2416 ocomp->decomp_free(ostate); 2417 module_put(ocomp->owner); 2418 } 2419 err = 0; 2420 } else 2421 module_put(cp->owner); 2422 } 2423 2424 out: 2425 return err; 2426 } 2427 2428 /* 2429 * Look at a CCP packet and update our state accordingly. 2430 * We assume the caller has the xmit or recv path locked. 2431 */ 2432 static void 2433 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound) 2434 { 2435 unsigned char *dp; 2436 int len; 2437 2438 if (!pskb_may_pull(skb, CCP_HDRLEN + 2)) 2439 return; /* no header */ 2440 dp = skb->data + 2; 2441 2442 switch (CCP_CODE(dp)) { 2443 case CCP_CONFREQ: 2444 2445 /* A ConfReq starts negotiation of compression 2446 * in one direction of transmission, 2447 * and hence brings it down...but which way? 2448 * 2449 * Remember: 2450 * A ConfReq indicates what the sender would like to receive 2451 */ 2452 if(inbound) 2453 /* He is proposing what I should send */ 2454 ppp->xstate &= ~SC_COMP_RUN; 2455 else 2456 /* I am proposing to what he should send */ 2457 ppp->rstate &= ~SC_DECOMP_RUN; 2458 2459 break; 2460 2461 case CCP_TERMREQ: 2462 case CCP_TERMACK: 2463 /* 2464 * CCP is going down, both directions of transmission 2465 */ 2466 ppp->rstate &= ~SC_DECOMP_RUN; 2467 ppp->xstate &= ~SC_COMP_RUN; 2468 break; 2469 2470 case CCP_CONFACK: 2471 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN) 2472 break; 2473 len = CCP_LENGTH(dp); 2474 if (!pskb_may_pull(skb, len + 2)) 2475 return; /* too short */ 2476 dp += CCP_HDRLEN; 2477 len -= CCP_HDRLEN; 2478 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp)) 2479 break; 2480 if (inbound) { 2481 /* we will start receiving compressed packets */ 2482 if (!ppp->rc_state) 2483 break; 2484 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len, 2485 ppp->file.index, 0, ppp->mru, ppp->debug)) { 2486 ppp->rstate |= SC_DECOMP_RUN; 2487 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR); 2488 } 2489 } else { 2490 /* we will soon start sending compressed packets */ 2491 if (!ppp->xc_state) 2492 break; 2493 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len, 2494 ppp->file.index, 0, ppp->debug)) 2495 ppp->xstate |= SC_COMP_RUN; 2496 } 2497 break; 2498 2499 case CCP_RESETACK: 2500 /* reset the [de]compressor */ 2501 if ((ppp->flags & SC_CCP_UP) == 0) 2502 break; 2503 if (inbound) { 2504 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) { 2505 ppp->rcomp->decomp_reset(ppp->rc_state); 2506 ppp->rstate &= ~SC_DC_ERROR; 2507 } 2508 } else { 2509 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN)) 2510 ppp->xcomp->comp_reset(ppp->xc_state); 2511 } 2512 break; 2513 } 2514 } 2515 2516 /* Free up compression resources. */ 2517 static void 2518 ppp_ccp_closed(struct ppp *ppp) 2519 { 2520 void *xstate, *rstate; 2521 struct compressor *xcomp, *rcomp; 2522 2523 ppp_lock(ppp); 2524 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP); 2525 ppp->xstate = 0; 2526 xcomp = ppp->xcomp; 2527 xstate = ppp->xc_state; 2528 ppp->xc_state = NULL; 2529 ppp->rstate = 0; 2530 rcomp = ppp->rcomp; 2531 rstate = ppp->rc_state; 2532 ppp->rc_state = NULL; 2533 ppp_unlock(ppp); 2534 2535 if (xstate) { 2536 xcomp->comp_free(xstate); 2537 module_put(xcomp->owner); 2538 } 2539 if (rstate) { 2540 rcomp->decomp_free(rstate); 2541 module_put(rcomp->owner); 2542 } 2543 } 2544 2545 /* List of compressors. */ 2546 static LIST_HEAD(compressor_list); 2547 static DEFINE_SPINLOCK(compressor_list_lock); 2548 2549 struct compressor_entry { 2550 struct list_head list; 2551 struct compressor *comp; 2552 }; 2553 2554 static struct compressor_entry * 2555 find_comp_entry(int proto) 2556 { 2557 struct compressor_entry *ce; 2558 2559 list_for_each_entry(ce, &compressor_list, list) { 2560 if (ce->comp->compress_proto == proto) 2561 return ce; 2562 } 2563 return NULL; 2564 } 2565 2566 /* Register a compressor */ 2567 int 2568 ppp_register_compressor(struct compressor *cp) 2569 { 2570 struct compressor_entry *ce; 2571 int ret; 2572 spin_lock(&compressor_list_lock); 2573 ret = -EEXIST; 2574 if (find_comp_entry(cp->compress_proto)) 2575 goto out; 2576 ret = -ENOMEM; 2577 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC); 2578 if (!ce) 2579 goto out; 2580 ret = 0; 2581 ce->comp = cp; 2582 list_add(&ce->list, &compressor_list); 2583 out: 2584 spin_unlock(&compressor_list_lock); 2585 return ret; 2586 } 2587 2588 /* Unregister a compressor */ 2589 void 2590 ppp_unregister_compressor(struct compressor *cp) 2591 { 2592 struct compressor_entry *ce; 2593 2594 spin_lock(&compressor_list_lock); 2595 ce = find_comp_entry(cp->compress_proto); 2596 if (ce && ce->comp == cp) { 2597 list_del(&ce->list); 2598 kfree(ce); 2599 } 2600 spin_unlock(&compressor_list_lock); 2601 } 2602 2603 /* Find a compressor. */ 2604 static struct compressor * 2605 find_compressor(int type) 2606 { 2607 struct compressor_entry *ce; 2608 struct compressor *cp = NULL; 2609 2610 spin_lock(&compressor_list_lock); 2611 ce = find_comp_entry(type); 2612 if (ce) { 2613 cp = ce->comp; 2614 if (!try_module_get(cp->owner)) 2615 cp = NULL; 2616 } 2617 spin_unlock(&compressor_list_lock); 2618 return cp; 2619 } 2620 2621 /* 2622 * Miscelleneous stuff. 2623 */ 2624 2625 static void 2626 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st) 2627 { 2628 struct slcompress *vj = ppp->vj; 2629 2630 memset(st, 0, sizeof(*st)); 2631 st->p.ppp_ipackets = ppp->stats64.rx_packets; 2632 st->p.ppp_ierrors = ppp->dev->stats.rx_errors; 2633 st->p.ppp_ibytes = ppp->stats64.rx_bytes; 2634 st->p.ppp_opackets = ppp->stats64.tx_packets; 2635 st->p.ppp_oerrors = ppp->dev->stats.tx_errors; 2636 st->p.ppp_obytes = ppp->stats64.tx_bytes; 2637 if (!vj) 2638 return; 2639 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed; 2640 st->vj.vjs_compressed = vj->sls_o_compressed; 2641 st->vj.vjs_searches = vj->sls_o_searches; 2642 st->vj.vjs_misses = vj->sls_o_misses; 2643 st->vj.vjs_errorin = vj->sls_i_error; 2644 st->vj.vjs_tossed = vj->sls_i_tossed; 2645 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed; 2646 st->vj.vjs_compressedin = vj->sls_i_compressed; 2647 } 2648 2649 /* 2650 * Stuff for handling the lists of ppp units and channels 2651 * and for initialization. 2652 */ 2653 2654 /* 2655 * Create a new ppp interface unit. Fails if it can't allocate memory 2656 * or if there is already a unit with the requested number. 2657 * unit == -1 means allocate a new number. 2658 */ 2659 static struct ppp * 2660 ppp_create_interface(struct net *net, int unit, int *retp) 2661 { 2662 struct ppp *ppp; 2663 struct ppp_net *pn; 2664 struct net_device *dev = NULL; 2665 int ret = -ENOMEM; 2666 int i; 2667 2668 dev = alloc_netdev(sizeof(struct ppp), "", ppp_setup); 2669 if (!dev) 2670 goto out1; 2671 2672 pn = ppp_pernet(net); 2673 2674 ppp = netdev_priv(dev); 2675 ppp->dev = dev; 2676 ppp->mru = PPP_MRU; 2677 init_ppp_file(&ppp->file, INTERFACE); 2678 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */ 2679 for (i = 0; i < NUM_NP; ++i) 2680 ppp->npmode[i] = NPMODE_PASS; 2681 INIT_LIST_HEAD(&ppp->channels); 2682 spin_lock_init(&ppp->rlock); 2683 spin_lock_init(&ppp->wlock); 2684 #ifdef CONFIG_PPP_MULTILINK 2685 ppp->minseq = -1; 2686 skb_queue_head_init(&ppp->mrq); 2687 #endif /* CONFIG_PPP_MULTILINK */ 2688 #ifdef CONFIG_PPP_FILTER 2689 ppp->pass_filter = NULL; 2690 ppp->active_filter = NULL; 2691 #endif /* CONFIG_PPP_FILTER */ 2692 2693 /* 2694 * drum roll: don't forget to set 2695 * the net device is belong to 2696 */ 2697 dev_net_set(dev, net); 2698 2699 mutex_lock(&pn->all_ppp_mutex); 2700 2701 if (unit < 0) { 2702 unit = unit_get(&pn->units_idr, ppp); 2703 if (unit < 0) { 2704 ret = unit; 2705 goto out2; 2706 } 2707 } else { 2708 ret = -EEXIST; 2709 if (unit_find(&pn->units_idr, unit)) 2710 goto out2; /* unit already exists */ 2711 /* 2712 * if caller need a specified unit number 2713 * lets try to satisfy him, otherwise -- 2714 * he should better ask us for new unit number 2715 * 2716 * NOTE: yes I know that returning EEXIST it's not 2717 * fair but at least pppd will ask us to allocate 2718 * new unit in this case so user is happy :) 2719 */ 2720 unit = unit_set(&pn->units_idr, ppp, unit); 2721 if (unit < 0) 2722 goto out2; 2723 } 2724 2725 /* Initialize the new ppp unit */ 2726 ppp->file.index = unit; 2727 sprintf(dev->name, "ppp%d", unit); 2728 2729 ret = register_netdev(dev); 2730 if (ret != 0) { 2731 unit_put(&pn->units_idr, unit); 2732 netdev_err(ppp->dev, "PPP: couldn't register device %s (%d)\n", 2733 dev->name, ret); 2734 goto out2; 2735 } 2736 2737 ppp->ppp_net = net; 2738 2739 atomic_inc(&ppp_unit_count); 2740 mutex_unlock(&pn->all_ppp_mutex); 2741 2742 *retp = 0; 2743 return ppp; 2744 2745 out2: 2746 mutex_unlock(&pn->all_ppp_mutex); 2747 free_netdev(dev); 2748 out1: 2749 *retp = ret; 2750 return NULL; 2751 } 2752 2753 /* 2754 * Initialize a ppp_file structure. 2755 */ 2756 static void 2757 init_ppp_file(struct ppp_file *pf, int kind) 2758 { 2759 pf->kind = kind; 2760 skb_queue_head_init(&pf->xq); 2761 skb_queue_head_init(&pf->rq); 2762 atomic_set(&pf->refcnt, 1); 2763 init_waitqueue_head(&pf->rwait); 2764 } 2765 2766 /* 2767 * Take down a ppp interface unit - called when the owning file 2768 * (the one that created the unit) is closed or detached. 2769 */ 2770 static void ppp_shutdown_interface(struct ppp *ppp) 2771 { 2772 struct ppp_net *pn; 2773 2774 pn = ppp_pernet(ppp->ppp_net); 2775 mutex_lock(&pn->all_ppp_mutex); 2776 2777 /* This will call dev_close() for us. */ 2778 ppp_lock(ppp); 2779 if (!ppp->closing) { 2780 ppp->closing = 1; 2781 ppp_unlock(ppp); 2782 unregister_netdev(ppp->dev); 2783 unit_put(&pn->units_idr, ppp->file.index); 2784 } else 2785 ppp_unlock(ppp); 2786 2787 ppp->file.dead = 1; 2788 ppp->owner = NULL; 2789 wake_up_interruptible(&ppp->file.rwait); 2790 2791 mutex_unlock(&pn->all_ppp_mutex); 2792 } 2793 2794 /* 2795 * Free the memory used by a ppp unit. This is only called once 2796 * there are no channels connected to the unit and no file structs 2797 * that reference the unit. 2798 */ 2799 static void ppp_destroy_interface(struct ppp *ppp) 2800 { 2801 atomic_dec(&ppp_unit_count); 2802 2803 if (!ppp->file.dead || ppp->n_channels) { 2804 /* "can't happen" */ 2805 netdev_err(ppp->dev, "ppp: destroying ppp struct %p " 2806 "but dead=%d n_channels=%d !\n", 2807 ppp, ppp->file.dead, ppp->n_channels); 2808 return; 2809 } 2810 2811 ppp_ccp_closed(ppp); 2812 if (ppp->vj) { 2813 slhc_free(ppp->vj); 2814 ppp->vj = NULL; 2815 } 2816 skb_queue_purge(&ppp->file.xq); 2817 skb_queue_purge(&ppp->file.rq); 2818 #ifdef CONFIG_PPP_MULTILINK 2819 skb_queue_purge(&ppp->mrq); 2820 #endif /* CONFIG_PPP_MULTILINK */ 2821 #ifdef CONFIG_PPP_FILTER 2822 if (ppp->pass_filter) { 2823 sk_unattached_filter_destroy(ppp->pass_filter); 2824 ppp->pass_filter = NULL; 2825 } 2826 2827 if (ppp->active_filter) { 2828 sk_unattached_filter_destroy(ppp->active_filter); 2829 ppp->active_filter = NULL; 2830 } 2831 #endif /* CONFIG_PPP_FILTER */ 2832 2833 kfree_skb(ppp->xmit_pending); 2834 2835 free_netdev(ppp->dev); 2836 } 2837 2838 /* 2839 * Locate an existing ppp unit. 2840 * The caller should have locked the all_ppp_mutex. 2841 */ 2842 static struct ppp * 2843 ppp_find_unit(struct ppp_net *pn, int unit) 2844 { 2845 return unit_find(&pn->units_idr, unit); 2846 } 2847 2848 /* 2849 * Locate an existing ppp channel. 2850 * The caller should have locked the all_channels_lock. 2851 * First we look in the new_channels list, then in the 2852 * all_channels list. If found in the new_channels list, 2853 * we move it to the all_channels list. This is for speed 2854 * when we have a lot of channels in use. 2855 */ 2856 static struct channel * 2857 ppp_find_channel(struct ppp_net *pn, int unit) 2858 { 2859 struct channel *pch; 2860 2861 list_for_each_entry(pch, &pn->new_channels, list) { 2862 if (pch->file.index == unit) { 2863 list_move(&pch->list, &pn->all_channels); 2864 return pch; 2865 } 2866 } 2867 2868 list_for_each_entry(pch, &pn->all_channels, list) { 2869 if (pch->file.index == unit) 2870 return pch; 2871 } 2872 2873 return NULL; 2874 } 2875 2876 /* 2877 * Connect a PPP channel to a PPP interface unit. 2878 */ 2879 static int 2880 ppp_connect_channel(struct channel *pch, int unit) 2881 { 2882 struct ppp *ppp; 2883 struct ppp_net *pn; 2884 int ret = -ENXIO; 2885 int hdrlen; 2886 2887 pn = ppp_pernet(pch->chan_net); 2888 2889 mutex_lock(&pn->all_ppp_mutex); 2890 ppp = ppp_find_unit(pn, unit); 2891 if (!ppp) 2892 goto out; 2893 write_lock_bh(&pch->upl); 2894 ret = -EINVAL; 2895 if (pch->ppp) 2896 goto outl; 2897 2898 ppp_lock(ppp); 2899 if (pch->file.hdrlen > ppp->file.hdrlen) 2900 ppp->file.hdrlen = pch->file.hdrlen; 2901 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */ 2902 if (hdrlen > ppp->dev->hard_header_len) 2903 ppp->dev->hard_header_len = hdrlen; 2904 list_add_tail(&pch->clist, &ppp->channels); 2905 ++ppp->n_channels; 2906 pch->ppp = ppp; 2907 atomic_inc(&ppp->file.refcnt); 2908 ppp_unlock(ppp); 2909 ret = 0; 2910 2911 outl: 2912 write_unlock_bh(&pch->upl); 2913 out: 2914 mutex_unlock(&pn->all_ppp_mutex); 2915 return ret; 2916 } 2917 2918 /* 2919 * Disconnect a channel from its ppp unit. 2920 */ 2921 static int 2922 ppp_disconnect_channel(struct channel *pch) 2923 { 2924 struct ppp *ppp; 2925 int err = -EINVAL; 2926 2927 write_lock_bh(&pch->upl); 2928 ppp = pch->ppp; 2929 pch->ppp = NULL; 2930 write_unlock_bh(&pch->upl); 2931 if (ppp) { 2932 /* remove it from the ppp unit's list */ 2933 ppp_lock(ppp); 2934 list_del(&pch->clist); 2935 if (--ppp->n_channels == 0) 2936 wake_up_interruptible(&ppp->file.rwait); 2937 ppp_unlock(ppp); 2938 if (atomic_dec_and_test(&ppp->file.refcnt)) 2939 ppp_destroy_interface(ppp); 2940 err = 0; 2941 } 2942 return err; 2943 } 2944 2945 /* 2946 * Free up the resources used by a ppp channel. 2947 */ 2948 static void ppp_destroy_channel(struct channel *pch) 2949 { 2950 atomic_dec(&channel_count); 2951 2952 if (!pch->file.dead) { 2953 /* "can't happen" */ 2954 pr_err("ppp: destroying undead channel %p !\n", pch); 2955 return; 2956 } 2957 skb_queue_purge(&pch->file.xq); 2958 skb_queue_purge(&pch->file.rq); 2959 kfree(pch); 2960 } 2961 2962 static void __exit ppp_cleanup(void) 2963 { 2964 /* should never happen */ 2965 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count)) 2966 pr_err("PPP: removing module but units remain!\n"); 2967 unregister_chrdev(PPP_MAJOR, "ppp"); 2968 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0)); 2969 class_destroy(ppp_class); 2970 unregister_pernet_device(&ppp_net_ops); 2971 } 2972 2973 /* 2974 * Units handling. Caller must protect concurrent access 2975 * by holding all_ppp_mutex 2976 */ 2977 2978 /* associate pointer with specified number */ 2979 static int unit_set(struct idr *p, void *ptr, int n) 2980 { 2981 int unit; 2982 2983 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL); 2984 if (unit == -ENOSPC) 2985 unit = -EINVAL; 2986 return unit; 2987 } 2988 2989 /* get new free unit number and associate pointer with it */ 2990 static int unit_get(struct idr *p, void *ptr) 2991 { 2992 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL); 2993 } 2994 2995 /* put unit number back to a pool */ 2996 static void unit_put(struct idr *p, int n) 2997 { 2998 idr_remove(p, n); 2999 } 3000 3001 /* get pointer associated with the number */ 3002 static void *unit_find(struct idr *p, int n) 3003 { 3004 return idr_find(p, n); 3005 } 3006 3007 /* Module/initialization stuff */ 3008 3009 module_init(ppp_init); 3010 module_exit(ppp_cleanup); 3011 3012 EXPORT_SYMBOL(ppp_register_net_channel); 3013 EXPORT_SYMBOL(ppp_register_channel); 3014 EXPORT_SYMBOL(ppp_unregister_channel); 3015 EXPORT_SYMBOL(ppp_channel_index); 3016 EXPORT_SYMBOL(ppp_unit_number); 3017 EXPORT_SYMBOL(ppp_dev_name); 3018 EXPORT_SYMBOL(ppp_input); 3019 EXPORT_SYMBOL(ppp_input_error); 3020 EXPORT_SYMBOL(ppp_output_wakeup); 3021 EXPORT_SYMBOL(ppp_register_compressor); 3022 EXPORT_SYMBOL(ppp_unregister_compressor); 3023 MODULE_LICENSE("GPL"); 3024 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0); 3025 MODULE_ALIAS("devname:ppp"); 3026