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