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; 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 *p = code; 558 return uprog.len; 559 } 560 #endif /* CONFIG_PPP_FILTER */ 561 562 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 563 { 564 struct ppp_file *pf = file->private_data; 565 struct ppp *ppp; 566 int err = -EFAULT, val, val2, i; 567 struct ppp_idle idle; 568 struct npioctl npi; 569 int unit, cflags; 570 struct slcompress *vj; 571 void __user *argp = (void __user *)arg; 572 int __user *p = argp; 573 574 if (!pf) 575 return ppp_unattached_ioctl(current->nsproxy->net_ns, 576 pf, file, cmd, arg); 577 578 if (cmd == PPPIOCDETACH) { 579 /* 580 * We have to be careful here... if the file descriptor 581 * has been dup'd, we could have another process in the 582 * middle of a poll using the same file *, so we had 583 * better not free the interface data structures - 584 * instead we fail the ioctl. Even in this case, we 585 * shut down the interface if we are the owner of it. 586 * Actually, we should get rid of PPPIOCDETACH, userland 587 * (i.e. pppd) could achieve the same effect by closing 588 * this fd and reopening /dev/ppp. 589 */ 590 err = -EINVAL; 591 mutex_lock(&ppp_mutex); 592 if (pf->kind == INTERFACE) { 593 ppp = PF_TO_PPP(pf); 594 if (file == ppp->owner) 595 ppp_shutdown_interface(ppp); 596 } 597 if (atomic_long_read(&file->f_count) <= 2) { 598 ppp_release(NULL, file); 599 err = 0; 600 } else 601 pr_warn("PPPIOCDETACH file->f_count=%ld\n", 602 atomic_long_read(&file->f_count)); 603 mutex_unlock(&ppp_mutex); 604 return err; 605 } 606 607 if (pf->kind == CHANNEL) { 608 struct channel *pch; 609 struct ppp_channel *chan; 610 611 mutex_lock(&ppp_mutex); 612 pch = PF_TO_CHANNEL(pf); 613 614 switch (cmd) { 615 case PPPIOCCONNECT: 616 if (get_user(unit, p)) 617 break; 618 err = ppp_connect_channel(pch, unit); 619 break; 620 621 case PPPIOCDISCONN: 622 err = ppp_disconnect_channel(pch); 623 break; 624 625 default: 626 down_read(&pch->chan_sem); 627 chan = pch->chan; 628 err = -ENOTTY; 629 if (chan && chan->ops->ioctl) 630 err = chan->ops->ioctl(chan, cmd, arg); 631 up_read(&pch->chan_sem); 632 } 633 mutex_unlock(&ppp_mutex); 634 return err; 635 } 636 637 if (pf->kind != INTERFACE) { 638 /* can't happen */ 639 pr_err("PPP: not interface or channel??\n"); 640 return -EINVAL; 641 } 642 643 mutex_lock(&ppp_mutex); 644 ppp = PF_TO_PPP(pf); 645 switch (cmd) { 646 case PPPIOCSMRU: 647 if (get_user(val, p)) 648 break; 649 ppp->mru = val; 650 err = 0; 651 break; 652 653 case PPPIOCSFLAGS: 654 if (get_user(val, p)) 655 break; 656 ppp_lock(ppp); 657 cflags = ppp->flags & ~val; 658 ppp->flags = val & SC_FLAG_BITS; 659 ppp_unlock(ppp); 660 if (cflags & SC_CCP_OPEN) 661 ppp_ccp_closed(ppp); 662 err = 0; 663 break; 664 665 case PPPIOCGFLAGS: 666 val = ppp->flags | ppp->xstate | ppp->rstate; 667 if (put_user(val, p)) 668 break; 669 err = 0; 670 break; 671 672 case PPPIOCSCOMPRESS: 673 err = ppp_set_compress(ppp, arg); 674 break; 675 676 case PPPIOCGUNIT: 677 if (put_user(ppp->file.index, p)) 678 break; 679 err = 0; 680 break; 681 682 case PPPIOCSDEBUG: 683 if (get_user(val, p)) 684 break; 685 ppp->debug = val; 686 err = 0; 687 break; 688 689 case PPPIOCGDEBUG: 690 if (put_user(ppp->debug, p)) 691 break; 692 err = 0; 693 break; 694 695 case PPPIOCGIDLE: 696 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ; 697 idle.recv_idle = (jiffies - ppp->last_recv) / HZ; 698 if (copy_to_user(argp, &idle, sizeof(idle))) 699 break; 700 err = 0; 701 break; 702 703 case PPPIOCSMAXCID: 704 if (get_user(val, p)) 705 break; 706 val2 = 15; 707 if ((val >> 16) != 0) { 708 val2 = val >> 16; 709 val &= 0xffff; 710 } 711 vj = slhc_init(val2+1, val+1); 712 if (!vj) { 713 netdev_err(ppp->dev, 714 "PPP: no memory (VJ compressor)\n"); 715 err = -ENOMEM; 716 break; 717 } 718 ppp_lock(ppp); 719 if (ppp->vj) 720 slhc_free(ppp->vj); 721 ppp->vj = vj; 722 ppp_unlock(ppp); 723 err = 0; 724 break; 725 726 case PPPIOCGNPMODE: 727 case PPPIOCSNPMODE: 728 if (copy_from_user(&npi, argp, sizeof(npi))) 729 break; 730 err = proto_to_npindex(npi.protocol); 731 if (err < 0) 732 break; 733 i = err; 734 if (cmd == PPPIOCGNPMODE) { 735 err = -EFAULT; 736 npi.mode = ppp->npmode[i]; 737 if (copy_to_user(argp, &npi, sizeof(npi))) 738 break; 739 } else { 740 ppp->npmode[i] = npi.mode; 741 /* we may be able to transmit more packets now (??) */ 742 netif_wake_queue(ppp->dev); 743 } 744 err = 0; 745 break; 746 747 #ifdef CONFIG_PPP_FILTER 748 case PPPIOCSPASS: 749 { 750 struct sock_filter *code; 751 752 err = get_filter(argp, &code); 753 if (err >= 0) { 754 struct sock_fprog_kern fprog = { 755 .len = err, 756 .filter = code, 757 }; 758 759 ppp_lock(ppp); 760 if (ppp->pass_filter) { 761 sk_unattached_filter_destroy(ppp->pass_filter); 762 ppp->pass_filter = NULL; 763 } 764 if (fprog.filter != NULL) 765 err = sk_unattached_filter_create(&ppp->pass_filter, 766 &fprog); 767 else 768 err = 0; 769 kfree(code); 770 ppp_unlock(ppp); 771 } 772 break; 773 } 774 case PPPIOCSACTIVE: 775 { 776 struct sock_filter *code; 777 778 err = get_filter(argp, &code); 779 if (err >= 0) { 780 struct sock_fprog_kern fprog = { 781 .len = err, 782 .filter = code, 783 }; 784 785 ppp_lock(ppp); 786 if (ppp->active_filter) { 787 sk_unattached_filter_destroy(ppp->active_filter); 788 ppp->active_filter = NULL; 789 } 790 if (fprog.filter != NULL) 791 err = sk_unattached_filter_create(&ppp->active_filter, 792 &fprog); 793 else 794 err = 0; 795 kfree(code); 796 ppp_unlock(ppp); 797 } 798 break; 799 } 800 #endif /* CONFIG_PPP_FILTER */ 801 802 #ifdef CONFIG_PPP_MULTILINK 803 case PPPIOCSMRRU: 804 if (get_user(val, p)) 805 break; 806 ppp_recv_lock(ppp); 807 ppp->mrru = val; 808 ppp_recv_unlock(ppp); 809 err = 0; 810 break; 811 #endif /* CONFIG_PPP_MULTILINK */ 812 813 default: 814 err = -ENOTTY; 815 } 816 mutex_unlock(&ppp_mutex); 817 return err; 818 } 819 820 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 821 struct file *file, unsigned int cmd, unsigned long arg) 822 { 823 int unit, err = -EFAULT; 824 struct ppp *ppp; 825 struct channel *chan; 826 struct ppp_net *pn; 827 int __user *p = (int __user *)arg; 828 829 mutex_lock(&ppp_mutex); 830 switch (cmd) { 831 case PPPIOCNEWUNIT: 832 /* Create a new ppp unit */ 833 if (get_user(unit, p)) 834 break; 835 ppp = ppp_create_interface(net, unit, &err); 836 if (!ppp) 837 break; 838 file->private_data = &ppp->file; 839 ppp->owner = file; 840 err = -EFAULT; 841 if (put_user(ppp->file.index, p)) 842 break; 843 err = 0; 844 break; 845 846 case PPPIOCATTACH: 847 /* Attach to an existing ppp unit */ 848 if (get_user(unit, p)) 849 break; 850 err = -ENXIO; 851 pn = ppp_pernet(net); 852 mutex_lock(&pn->all_ppp_mutex); 853 ppp = ppp_find_unit(pn, unit); 854 if (ppp) { 855 atomic_inc(&ppp->file.refcnt); 856 file->private_data = &ppp->file; 857 err = 0; 858 } 859 mutex_unlock(&pn->all_ppp_mutex); 860 break; 861 862 case PPPIOCATTCHAN: 863 if (get_user(unit, p)) 864 break; 865 err = -ENXIO; 866 pn = ppp_pernet(net); 867 spin_lock_bh(&pn->all_channels_lock); 868 chan = ppp_find_channel(pn, unit); 869 if (chan) { 870 atomic_inc(&chan->file.refcnt); 871 file->private_data = &chan->file; 872 err = 0; 873 } 874 spin_unlock_bh(&pn->all_channels_lock); 875 break; 876 877 default: 878 err = -ENOTTY; 879 } 880 mutex_unlock(&ppp_mutex); 881 return err; 882 } 883 884 static const struct file_operations ppp_device_fops = { 885 .owner = THIS_MODULE, 886 .read = ppp_read, 887 .write = ppp_write, 888 .poll = ppp_poll, 889 .unlocked_ioctl = ppp_ioctl, 890 .open = ppp_open, 891 .release = ppp_release, 892 .llseek = noop_llseek, 893 }; 894 895 static __net_init int ppp_init_net(struct net *net) 896 { 897 struct ppp_net *pn = net_generic(net, ppp_net_id); 898 899 idr_init(&pn->units_idr); 900 mutex_init(&pn->all_ppp_mutex); 901 902 INIT_LIST_HEAD(&pn->all_channels); 903 INIT_LIST_HEAD(&pn->new_channels); 904 905 spin_lock_init(&pn->all_channels_lock); 906 907 return 0; 908 } 909 910 static __net_exit void ppp_exit_net(struct net *net) 911 { 912 struct ppp_net *pn = net_generic(net, ppp_net_id); 913 914 idr_destroy(&pn->units_idr); 915 } 916 917 static struct pernet_operations ppp_net_ops = { 918 .init = ppp_init_net, 919 .exit = ppp_exit_net, 920 .id = &ppp_net_id, 921 .size = sizeof(struct ppp_net), 922 }; 923 924 #define PPP_MAJOR 108 925 926 /* Called at boot time if ppp is compiled into the kernel, 927 or at module load time (from init_module) if compiled as a module. */ 928 static int __init ppp_init(void) 929 { 930 int err; 931 932 pr_info("PPP generic driver version " PPP_VERSION "\n"); 933 934 err = register_pernet_device(&ppp_net_ops); 935 if (err) { 936 pr_err("failed to register PPP pernet device (%d)\n", err); 937 goto out; 938 } 939 940 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops); 941 if (err) { 942 pr_err("failed to register PPP device (%d)\n", err); 943 goto out_net; 944 } 945 946 ppp_class = class_create(THIS_MODULE, "ppp"); 947 if (IS_ERR(ppp_class)) { 948 err = PTR_ERR(ppp_class); 949 goto out_chrdev; 950 } 951 952 /* not a big deal if we fail here :-) */ 953 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp"); 954 955 return 0; 956 957 out_chrdev: 958 unregister_chrdev(PPP_MAJOR, "ppp"); 959 out_net: 960 unregister_pernet_device(&ppp_net_ops); 961 out: 962 return err; 963 } 964 965 /* 966 * Network interface unit routines. 967 */ 968 static netdev_tx_t 969 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev) 970 { 971 struct ppp *ppp = netdev_priv(dev); 972 int npi, proto; 973 unsigned char *pp; 974 975 npi = ethertype_to_npindex(ntohs(skb->protocol)); 976 if (npi < 0) 977 goto outf; 978 979 /* Drop, accept or reject the packet */ 980 switch (ppp->npmode[npi]) { 981 case NPMODE_PASS: 982 break; 983 case NPMODE_QUEUE: 984 /* it would be nice to have a way to tell the network 985 system to queue this one up for later. */ 986 goto outf; 987 case NPMODE_DROP: 988 case NPMODE_ERROR: 989 goto outf; 990 } 991 992 /* Put the 2-byte PPP protocol number on the front, 993 making sure there is room for the address and control fields. */ 994 if (skb_cow_head(skb, PPP_HDRLEN)) 995 goto outf; 996 997 pp = skb_push(skb, 2); 998 proto = npindex_to_proto[npi]; 999 put_unaligned_be16(proto, pp); 1000 1001 skb_queue_tail(&ppp->file.xq, skb); 1002 ppp_xmit_process(ppp); 1003 return NETDEV_TX_OK; 1004 1005 outf: 1006 kfree_skb(skb); 1007 ++dev->stats.tx_dropped; 1008 return NETDEV_TX_OK; 1009 } 1010 1011 static int 1012 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 1013 { 1014 struct ppp *ppp = netdev_priv(dev); 1015 int err = -EFAULT; 1016 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data; 1017 struct ppp_stats stats; 1018 struct ppp_comp_stats cstats; 1019 char *vers; 1020 1021 switch (cmd) { 1022 case SIOCGPPPSTATS: 1023 ppp_get_stats(ppp, &stats); 1024 if (copy_to_user(addr, &stats, sizeof(stats))) 1025 break; 1026 err = 0; 1027 break; 1028 1029 case SIOCGPPPCSTATS: 1030 memset(&cstats, 0, sizeof(cstats)); 1031 if (ppp->xc_state) 1032 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c); 1033 if (ppp->rc_state) 1034 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d); 1035 if (copy_to_user(addr, &cstats, sizeof(cstats))) 1036 break; 1037 err = 0; 1038 break; 1039 1040 case SIOCGPPPVER: 1041 vers = PPP_VERSION; 1042 if (copy_to_user(addr, vers, strlen(vers) + 1)) 1043 break; 1044 err = 0; 1045 break; 1046 1047 default: 1048 err = -EINVAL; 1049 } 1050 1051 return err; 1052 } 1053 1054 static struct rtnl_link_stats64* 1055 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64) 1056 { 1057 struct ppp *ppp = netdev_priv(dev); 1058 1059 ppp_recv_lock(ppp); 1060 stats64->rx_packets = ppp->stats64.rx_packets; 1061 stats64->rx_bytes = ppp->stats64.rx_bytes; 1062 ppp_recv_unlock(ppp); 1063 1064 ppp_xmit_lock(ppp); 1065 stats64->tx_packets = ppp->stats64.tx_packets; 1066 stats64->tx_bytes = ppp->stats64.tx_bytes; 1067 ppp_xmit_unlock(ppp); 1068 1069 stats64->rx_errors = dev->stats.rx_errors; 1070 stats64->tx_errors = dev->stats.tx_errors; 1071 stats64->rx_dropped = dev->stats.rx_dropped; 1072 stats64->tx_dropped = dev->stats.tx_dropped; 1073 stats64->rx_length_errors = dev->stats.rx_length_errors; 1074 1075 return stats64; 1076 } 1077 1078 static struct lock_class_key ppp_tx_busylock; 1079 static int ppp_dev_init(struct net_device *dev) 1080 { 1081 dev->qdisc_tx_busylock = &ppp_tx_busylock; 1082 return 0; 1083 } 1084 1085 static const struct net_device_ops ppp_netdev_ops = { 1086 .ndo_init = ppp_dev_init, 1087 .ndo_start_xmit = ppp_start_xmit, 1088 .ndo_do_ioctl = ppp_net_ioctl, 1089 .ndo_get_stats64 = ppp_get_stats64, 1090 }; 1091 1092 static void ppp_setup(struct net_device *dev) 1093 { 1094 dev->netdev_ops = &ppp_netdev_ops; 1095 dev->hard_header_len = PPP_HDRLEN; 1096 dev->mtu = PPP_MRU; 1097 dev->addr_len = 0; 1098 dev->tx_queue_len = 3; 1099 dev->type = ARPHRD_PPP; 1100 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 1101 dev->features |= NETIF_F_NETNS_LOCAL; 1102 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 1103 } 1104 1105 /* 1106 * Transmit-side routines. 1107 */ 1108 1109 /* 1110 * Called to do any work queued up on the transmit side 1111 * that can now be done. 1112 */ 1113 static void 1114 ppp_xmit_process(struct ppp *ppp) 1115 { 1116 struct sk_buff *skb; 1117 1118 ppp_xmit_lock(ppp); 1119 if (!ppp->closing) { 1120 ppp_push(ppp); 1121 while (!ppp->xmit_pending && 1122 (skb = skb_dequeue(&ppp->file.xq))) 1123 ppp_send_frame(ppp, skb); 1124 /* If there's no work left to do, tell the core net 1125 code that we can accept some more. */ 1126 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq)) 1127 netif_wake_queue(ppp->dev); 1128 else 1129 netif_stop_queue(ppp->dev); 1130 } 1131 ppp_xmit_unlock(ppp); 1132 } 1133 1134 static inline struct sk_buff * 1135 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) 1136 { 1137 struct sk_buff *new_skb; 1138 int len; 1139 int new_skb_size = ppp->dev->mtu + 1140 ppp->xcomp->comp_extra + ppp->dev->hard_header_len; 1141 int compressor_skb_size = ppp->dev->mtu + 1142 ppp->xcomp->comp_extra + PPP_HDRLEN; 1143 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC); 1144 if (!new_skb) { 1145 if (net_ratelimit()) 1146 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n"); 1147 return NULL; 1148 } 1149 if (ppp->dev->hard_header_len > PPP_HDRLEN) 1150 skb_reserve(new_skb, 1151 ppp->dev->hard_header_len - PPP_HDRLEN); 1152 1153 /* compressor still expects A/C bytes in hdr */ 1154 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, 1155 new_skb->data, skb->len + 2, 1156 compressor_skb_size); 1157 if (len > 0 && (ppp->flags & SC_CCP_UP)) { 1158 consume_skb(skb); 1159 skb = new_skb; 1160 skb_put(skb, len); 1161 skb_pull(skb, 2); /* pull off A/C bytes */ 1162 } else if (len == 0) { 1163 /* didn't compress, or CCP not up yet */ 1164 consume_skb(new_skb); 1165 new_skb = skb; 1166 } else { 1167 /* 1168 * (len < 0) 1169 * MPPE requires that we do not send unencrypted 1170 * frames. The compressor will return -1 if we 1171 * should drop the frame. We cannot simply test 1172 * the compress_proto because MPPE and MPPC share 1173 * the same number. 1174 */ 1175 if (net_ratelimit()) 1176 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n"); 1177 kfree_skb(skb); 1178 consume_skb(new_skb); 1179 new_skb = NULL; 1180 } 1181 return new_skb; 1182 } 1183 1184 /* 1185 * Compress and send a frame. 1186 * The caller should have locked the xmit path, 1187 * and xmit_pending should be 0. 1188 */ 1189 static void 1190 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) 1191 { 1192 int proto = PPP_PROTO(skb); 1193 struct sk_buff *new_skb; 1194 int len; 1195 unsigned char *cp; 1196 1197 if (proto < 0x8000) { 1198 #ifdef CONFIG_PPP_FILTER 1199 /* check if we should pass this packet */ 1200 /* the filter instructions are constructed assuming 1201 a four-byte PPP header on each packet */ 1202 *skb_push(skb, 2) = 1; 1203 if (ppp->pass_filter && 1204 SK_RUN_FILTER(ppp->pass_filter, skb) == 0) { 1205 if (ppp->debug & 1) 1206 netdev_printk(KERN_DEBUG, ppp->dev, 1207 "PPP: outbound frame " 1208 "not passed\n"); 1209 kfree_skb(skb); 1210 return; 1211 } 1212 /* if this packet passes the active filter, record the time */ 1213 if (!(ppp->active_filter && 1214 SK_RUN_FILTER(ppp->active_filter, skb) == 0)) 1215 ppp->last_xmit = jiffies; 1216 skb_pull(skb, 2); 1217 #else 1218 /* for data packets, record the time */ 1219 ppp->last_xmit = jiffies; 1220 #endif /* CONFIG_PPP_FILTER */ 1221 } 1222 1223 ++ppp->stats64.tx_packets; 1224 ppp->stats64.tx_bytes += skb->len - 2; 1225 1226 switch (proto) { 1227 case PPP_IP: 1228 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0) 1229 break; 1230 /* try to do VJ TCP header compression */ 1231 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2, 1232 GFP_ATOMIC); 1233 if (!new_skb) { 1234 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n"); 1235 goto drop; 1236 } 1237 skb_reserve(new_skb, ppp->dev->hard_header_len - 2); 1238 cp = skb->data + 2; 1239 len = slhc_compress(ppp->vj, cp, skb->len - 2, 1240 new_skb->data + 2, &cp, 1241 !(ppp->flags & SC_NO_TCP_CCID)); 1242 if (cp == skb->data + 2) { 1243 /* didn't compress */ 1244 consume_skb(new_skb); 1245 } else { 1246 if (cp[0] & SL_TYPE_COMPRESSED_TCP) { 1247 proto = PPP_VJC_COMP; 1248 cp[0] &= ~SL_TYPE_COMPRESSED_TCP; 1249 } else { 1250 proto = PPP_VJC_UNCOMP; 1251 cp[0] = skb->data[2]; 1252 } 1253 consume_skb(skb); 1254 skb = new_skb; 1255 cp = skb_put(skb, len + 2); 1256 cp[0] = 0; 1257 cp[1] = proto; 1258 } 1259 break; 1260 1261 case PPP_CCP: 1262 /* peek at outbound CCP frames */ 1263 ppp_ccp_peek(ppp, skb, 0); 1264 break; 1265 } 1266 1267 /* try to do packet compression */ 1268 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state && 1269 proto != PPP_LCP && proto != PPP_CCP) { 1270 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) { 1271 if (net_ratelimit()) 1272 netdev_err(ppp->dev, 1273 "ppp: compression required but " 1274 "down - pkt dropped.\n"); 1275 goto drop; 1276 } 1277 skb = pad_compress_skb(ppp, skb); 1278 if (!skb) 1279 goto drop; 1280 } 1281 1282 /* 1283 * If we are waiting for traffic (demand dialling), 1284 * queue it up for pppd to receive. 1285 */ 1286 if (ppp->flags & SC_LOOP_TRAFFIC) { 1287 if (ppp->file.rq.qlen > PPP_MAX_RQLEN) 1288 goto drop; 1289 skb_queue_tail(&ppp->file.rq, skb); 1290 wake_up_interruptible(&ppp->file.rwait); 1291 return; 1292 } 1293 1294 ppp->xmit_pending = skb; 1295 ppp_push(ppp); 1296 return; 1297 1298 drop: 1299 kfree_skb(skb); 1300 ++ppp->dev->stats.tx_errors; 1301 } 1302 1303 /* 1304 * Try to send the frame in xmit_pending. 1305 * The caller should have the xmit path locked. 1306 */ 1307 static void 1308 ppp_push(struct ppp *ppp) 1309 { 1310 struct list_head *list; 1311 struct channel *pch; 1312 struct sk_buff *skb = ppp->xmit_pending; 1313 1314 if (!skb) 1315 return; 1316 1317 list = &ppp->channels; 1318 if (list_empty(list)) { 1319 /* nowhere to send the packet, just drop it */ 1320 ppp->xmit_pending = NULL; 1321 kfree_skb(skb); 1322 return; 1323 } 1324 1325 if ((ppp->flags & SC_MULTILINK) == 0) { 1326 /* not doing multilink: send it down the first channel */ 1327 list = list->next; 1328 pch = list_entry(list, struct channel, clist); 1329 1330 spin_lock_bh(&pch->downl); 1331 if (pch->chan) { 1332 if (pch->chan->ops->start_xmit(pch->chan, skb)) 1333 ppp->xmit_pending = NULL; 1334 } else { 1335 /* channel got unregistered */ 1336 kfree_skb(skb); 1337 ppp->xmit_pending = NULL; 1338 } 1339 spin_unlock_bh(&pch->downl); 1340 return; 1341 } 1342 1343 #ifdef CONFIG_PPP_MULTILINK 1344 /* Multilink: fragment the packet over as many links 1345 as can take the packet at the moment. */ 1346 if (!ppp_mp_explode(ppp, skb)) 1347 return; 1348 #endif /* CONFIG_PPP_MULTILINK */ 1349 1350 ppp->xmit_pending = NULL; 1351 kfree_skb(skb); 1352 } 1353 1354 #ifdef CONFIG_PPP_MULTILINK 1355 static bool mp_protocol_compress __read_mostly = true; 1356 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR); 1357 MODULE_PARM_DESC(mp_protocol_compress, 1358 "compress protocol id in multilink fragments"); 1359 1360 /* 1361 * Divide a packet to be transmitted into fragments and 1362 * send them out the individual links. 1363 */ 1364 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb) 1365 { 1366 int len, totlen; 1367 int i, bits, hdrlen, mtu; 1368 int flen; 1369 int navail, nfree, nzero; 1370 int nbigger; 1371 int totspeed; 1372 int totfree; 1373 unsigned char *p, *q; 1374 struct list_head *list; 1375 struct channel *pch; 1376 struct sk_buff *frag; 1377 struct ppp_channel *chan; 1378 1379 totspeed = 0; /*total bitrate of the bundle*/ 1380 nfree = 0; /* # channels which have no packet already queued */ 1381 navail = 0; /* total # of usable channels (not deregistered) */ 1382 nzero = 0; /* number of channels with zero speed associated*/ 1383 totfree = 0; /*total # of channels available and 1384 *having no queued packets before 1385 *starting the fragmentation*/ 1386 1387 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1388 i = 0; 1389 list_for_each_entry(pch, &ppp->channels, clist) { 1390 if (pch->chan) { 1391 pch->avail = 1; 1392 navail++; 1393 pch->speed = pch->chan->speed; 1394 } else { 1395 pch->avail = 0; 1396 } 1397 if (pch->avail) { 1398 if (skb_queue_empty(&pch->file.xq) || 1399 !pch->had_frag) { 1400 if (pch->speed == 0) 1401 nzero++; 1402 else 1403 totspeed += pch->speed; 1404 1405 pch->avail = 2; 1406 ++nfree; 1407 ++totfree; 1408 } 1409 if (!pch->had_frag && i < ppp->nxchan) 1410 ppp->nxchan = i; 1411 } 1412 ++i; 1413 } 1414 /* 1415 * Don't start sending this packet unless at least half of 1416 * the channels are free. This gives much better TCP 1417 * performance if we have a lot of channels. 1418 */ 1419 if (nfree == 0 || nfree < navail / 2) 1420 return 0; /* can't take now, leave it in xmit_pending */ 1421 1422 /* Do protocol field compression */ 1423 p = skb->data; 1424 len = skb->len; 1425 if (*p == 0 && mp_protocol_compress) { 1426 ++p; 1427 --len; 1428 } 1429 1430 totlen = len; 1431 nbigger = len % nfree; 1432 1433 /* skip to the channel after the one we last used 1434 and start at that one */ 1435 list = &ppp->channels; 1436 for (i = 0; i < ppp->nxchan; ++i) { 1437 list = list->next; 1438 if (list == &ppp->channels) { 1439 i = 0; 1440 break; 1441 } 1442 } 1443 1444 /* create a fragment for each channel */ 1445 bits = B; 1446 while (len > 0) { 1447 list = list->next; 1448 if (list == &ppp->channels) { 1449 i = 0; 1450 continue; 1451 } 1452 pch = list_entry(list, struct channel, clist); 1453 ++i; 1454 if (!pch->avail) 1455 continue; 1456 1457 /* 1458 * Skip this channel if it has a fragment pending already and 1459 * we haven't given a fragment to all of the free channels. 1460 */ 1461 if (pch->avail == 1) { 1462 if (nfree > 0) 1463 continue; 1464 } else { 1465 pch->avail = 1; 1466 } 1467 1468 /* check the channel's mtu and whether it is still attached. */ 1469 spin_lock_bh(&pch->downl); 1470 if (pch->chan == NULL) { 1471 /* can't use this channel, it's being deregistered */ 1472 if (pch->speed == 0) 1473 nzero--; 1474 else 1475 totspeed -= pch->speed; 1476 1477 spin_unlock_bh(&pch->downl); 1478 pch->avail = 0; 1479 totlen = len; 1480 totfree--; 1481 nfree--; 1482 if (--navail == 0) 1483 break; 1484 continue; 1485 } 1486 1487 /* 1488 *if the channel speed is not set divide 1489 *the packet evenly among the free channels; 1490 *otherwise divide it according to the speed 1491 *of the channel we are going to transmit on 1492 */ 1493 flen = len; 1494 if (nfree > 0) { 1495 if (pch->speed == 0) { 1496 flen = len/nfree; 1497 if (nbigger > 0) { 1498 flen++; 1499 nbigger--; 1500 } 1501 } else { 1502 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) / 1503 ((totspeed*totfree)/pch->speed)) - hdrlen; 1504 if (nbigger > 0) { 1505 flen += ((totfree - nzero)*pch->speed)/totspeed; 1506 nbigger -= ((totfree - nzero)*pch->speed)/ 1507 totspeed; 1508 } 1509 } 1510 nfree--; 1511 } 1512 1513 /* 1514 *check if we are on the last channel or 1515 *we exceded the length of the data to 1516 *fragment 1517 */ 1518 if ((nfree <= 0) || (flen > len)) 1519 flen = len; 1520 /* 1521 *it is not worth to tx on slow channels: 1522 *in that case from the resulting flen according to the 1523 *above formula will be equal or less than zero. 1524 *Skip the channel in this case 1525 */ 1526 if (flen <= 0) { 1527 pch->avail = 2; 1528 spin_unlock_bh(&pch->downl); 1529 continue; 1530 } 1531 1532 /* 1533 * hdrlen includes the 2-byte PPP protocol field, but the 1534 * MTU counts only the payload excluding the protocol field. 1535 * (RFC1661 Section 2) 1536 */ 1537 mtu = pch->chan->mtu - (hdrlen - 2); 1538 if (mtu < 4) 1539 mtu = 4; 1540 if (flen > mtu) 1541 flen = mtu; 1542 if (flen == len) 1543 bits |= E; 1544 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC); 1545 if (!frag) 1546 goto noskb; 1547 q = skb_put(frag, flen + hdrlen); 1548 1549 /* make the MP header */ 1550 put_unaligned_be16(PPP_MP, q); 1551 if (ppp->flags & SC_MP_XSHORTSEQ) { 1552 q[2] = bits + ((ppp->nxseq >> 8) & 0xf); 1553 q[3] = ppp->nxseq; 1554 } else { 1555 q[2] = bits; 1556 q[3] = ppp->nxseq >> 16; 1557 q[4] = ppp->nxseq >> 8; 1558 q[5] = ppp->nxseq; 1559 } 1560 1561 memcpy(q + hdrlen, p, flen); 1562 1563 /* try to send it down the channel */ 1564 chan = pch->chan; 1565 if (!skb_queue_empty(&pch->file.xq) || 1566 !chan->ops->start_xmit(chan, frag)) 1567 skb_queue_tail(&pch->file.xq, frag); 1568 pch->had_frag = 1; 1569 p += flen; 1570 len -= flen; 1571 ++ppp->nxseq; 1572 bits = 0; 1573 spin_unlock_bh(&pch->downl); 1574 } 1575 ppp->nxchan = i; 1576 1577 return 1; 1578 1579 noskb: 1580 spin_unlock_bh(&pch->downl); 1581 if (ppp->debug & 1) 1582 netdev_err(ppp->dev, "PPP: no memory (fragment)\n"); 1583 ++ppp->dev->stats.tx_errors; 1584 ++ppp->nxseq; 1585 return 1; /* abandon the frame */ 1586 } 1587 #endif /* CONFIG_PPP_MULTILINK */ 1588 1589 /* 1590 * Try to send data out on a channel. 1591 */ 1592 static void 1593 ppp_channel_push(struct channel *pch) 1594 { 1595 struct sk_buff *skb; 1596 struct ppp *ppp; 1597 1598 spin_lock_bh(&pch->downl); 1599 if (pch->chan) { 1600 while (!skb_queue_empty(&pch->file.xq)) { 1601 skb = skb_dequeue(&pch->file.xq); 1602 if (!pch->chan->ops->start_xmit(pch->chan, skb)) { 1603 /* put the packet back and try again later */ 1604 skb_queue_head(&pch->file.xq, skb); 1605 break; 1606 } 1607 } 1608 } else { 1609 /* channel got deregistered */ 1610 skb_queue_purge(&pch->file.xq); 1611 } 1612 spin_unlock_bh(&pch->downl); 1613 /* see if there is anything from the attached unit to be sent */ 1614 if (skb_queue_empty(&pch->file.xq)) { 1615 read_lock_bh(&pch->upl); 1616 ppp = pch->ppp; 1617 if (ppp) 1618 ppp_xmit_process(ppp); 1619 read_unlock_bh(&pch->upl); 1620 } 1621 } 1622 1623 /* 1624 * Receive-side routines. 1625 */ 1626 1627 struct ppp_mp_skb_parm { 1628 u32 sequence; 1629 u8 BEbits; 1630 }; 1631 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb)) 1632 1633 static inline void 1634 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1635 { 1636 ppp_recv_lock(ppp); 1637 if (!ppp->closing) 1638 ppp_receive_frame(ppp, skb, pch); 1639 else 1640 kfree_skb(skb); 1641 ppp_recv_unlock(ppp); 1642 } 1643 1644 void 1645 ppp_input(struct ppp_channel *chan, struct sk_buff *skb) 1646 { 1647 struct channel *pch = chan->ppp; 1648 int proto; 1649 1650 if (!pch) { 1651 kfree_skb(skb); 1652 return; 1653 } 1654 1655 read_lock_bh(&pch->upl); 1656 if (!pskb_may_pull(skb, 2)) { 1657 kfree_skb(skb); 1658 if (pch->ppp) { 1659 ++pch->ppp->dev->stats.rx_length_errors; 1660 ppp_receive_error(pch->ppp); 1661 } 1662 goto done; 1663 } 1664 1665 proto = PPP_PROTO(skb); 1666 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) { 1667 /* put it on the channel queue */ 1668 skb_queue_tail(&pch->file.rq, skb); 1669 /* drop old frames if queue too long */ 1670 while (pch->file.rq.qlen > PPP_MAX_RQLEN && 1671 (skb = skb_dequeue(&pch->file.rq))) 1672 kfree_skb(skb); 1673 wake_up_interruptible(&pch->file.rwait); 1674 } else { 1675 ppp_do_recv(pch->ppp, skb, pch); 1676 } 1677 1678 done: 1679 read_unlock_bh(&pch->upl); 1680 } 1681 1682 /* Put a 0-length skb in the receive queue as an error indication */ 1683 void 1684 ppp_input_error(struct ppp_channel *chan, int code) 1685 { 1686 struct channel *pch = chan->ppp; 1687 struct sk_buff *skb; 1688 1689 if (!pch) 1690 return; 1691 1692 read_lock_bh(&pch->upl); 1693 if (pch->ppp) { 1694 skb = alloc_skb(0, GFP_ATOMIC); 1695 if (skb) { 1696 skb->len = 0; /* probably unnecessary */ 1697 skb->cb[0] = code; 1698 ppp_do_recv(pch->ppp, skb, pch); 1699 } 1700 } 1701 read_unlock_bh(&pch->upl); 1702 } 1703 1704 /* 1705 * We come in here to process a received frame. 1706 * The receive side of the ppp unit is locked. 1707 */ 1708 static void 1709 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1710 { 1711 /* note: a 0-length skb is used as an error indication */ 1712 if (skb->len > 0) { 1713 #ifdef CONFIG_PPP_MULTILINK 1714 /* XXX do channel-level decompression here */ 1715 if (PPP_PROTO(skb) == PPP_MP) 1716 ppp_receive_mp_frame(ppp, skb, pch); 1717 else 1718 #endif /* CONFIG_PPP_MULTILINK */ 1719 ppp_receive_nonmp_frame(ppp, skb); 1720 } else { 1721 kfree_skb(skb); 1722 ppp_receive_error(ppp); 1723 } 1724 } 1725 1726 static void 1727 ppp_receive_error(struct ppp *ppp) 1728 { 1729 ++ppp->dev->stats.rx_errors; 1730 if (ppp->vj) 1731 slhc_toss(ppp->vj); 1732 } 1733 1734 static void 1735 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) 1736 { 1737 struct sk_buff *ns; 1738 int proto, len, npi; 1739 1740 /* 1741 * Decompress the frame, if compressed. 1742 * Note that some decompressors need to see uncompressed frames 1743 * that come in as well as compressed frames. 1744 */ 1745 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) && 1746 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0) 1747 skb = ppp_decompress_frame(ppp, skb); 1748 1749 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR) 1750 goto err; 1751 1752 proto = PPP_PROTO(skb); 1753 switch (proto) { 1754 case PPP_VJC_COMP: 1755 /* decompress VJ compressed packets */ 1756 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 1757 goto err; 1758 1759 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) { 1760 /* copy to a new sk_buff with more tailroom */ 1761 ns = dev_alloc_skb(skb->len + 128); 1762 if (!ns) { 1763 netdev_err(ppp->dev, "PPP: no memory " 1764 "(VJ decomp)\n"); 1765 goto err; 1766 } 1767 skb_reserve(ns, 2); 1768 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len); 1769 consume_skb(skb); 1770 skb = ns; 1771 } 1772 else 1773 skb->ip_summed = CHECKSUM_NONE; 1774 1775 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2); 1776 if (len <= 0) { 1777 netdev_printk(KERN_DEBUG, ppp->dev, 1778 "PPP: VJ decompression error\n"); 1779 goto err; 1780 } 1781 len += 2; 1782 if (len > skb->len) 1783 skb_put(skb, len - skb->len); 1784 else if (len < skb->len) 1785 skb_trim(skb, len); 1786 proto = PPP_IP; 1787 break; 1788 1789 case PPP_VJC_UNCOMP: 1790 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 1791 goto err; 1792 1793 /* Until we fix the decompressor need to make sure 1794 * data portion is linear. 1795 */ 1796 if (!pskb_may_pull(skb, skb->len)) 1797 goto err; 1798 1799 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) { 1800 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n"); 1801 goto err; 1802 } 1803 proto = PPP_IP; 1804 break; 1805 1806 case PPP_CCP: 1807 ppp_ccp_peek(ppp, skb, 1); 1808 break; 1809 } 1810 1811 ++ppp->stats64.rx_packets; 1812 ppp->stats64.rx_bytes += skb->len - 2; 1813 1814 npi = proto_to_npindex(proto); 1815 if (npi < 0) { 1816 /* control or unknown frame - pass it to pppd */ 1817 skb_queue_tail(&ppp->file.rq, skb); 1818 /* limit queue length by dropping old frames */ 1819 while (ppp->file.rq.qlen > PPP_MAX_RQLEN && 1820 (skb = skb_dequeue(&ppp->file.rq))) 1821 kfree_skb(skb); 1822 /* wake up any process polling or blocking on read */ 1823 wake_up_interruptible(&ppp->file.rwait); 1824 1825 } else { 1826 /* network protocol frame - give it to the kernel */ 1827 1828 #ifdef CONFIG_PPP_FILTER 1829 /* check if the packet passes the pass and active filters */ 1830 /* the filter instructions are constructed assuming 1831 a four-byte PPP header on each packet */ 1832 if (ppp->pass_filter || ppp->active_filter) { 1833 if (skb_unclone(skb, GFP_ATOMIC)) 1834 goto err; 1835 1836 *skb_push(skb, 2) = 0; 1837 if (ppp->pass_filter && 1838 SK_RUN_FILTER(ppp->pass_filter, skb) == 0) { 1839 if (ppp->debug & 1) 1840 netdev_printk(KERN_DEBUG, ppp->dev, 1841 "PPP: inbound frame " 1842 "not passed\n"); 1843 kfree_skb(skb); 1844 return; 1845 } 1846 if (!(ppp->active_filter && 1847 SK_RUN_FILTER(ppp->active_filter, skb) == 0)) 1848 ppp->last_recv = jiffies; 1849 __skb_pull(skb, 2); 1850 } else 1851 #endif /* CONFIG_PPP_FILTER */ 1852 ppp->last_recv = jiffies; 1853 1854 if ((ppp->dev->flags & IFF_UP) == 0 || 1855 ppp->npmode[npi] != NPMODE_PASS) { 1856 kfree_skb(skb); 1857 } else { 1858 /* chop off protocol */ 1859 skb_pull_rcsum(skb, 2); 1860 skb->dev = ppp->dev; 1861 skb->protocol = htons(npindex_to_ethertype[npi]); 1862 skb_reset_mac_header(skb); 1863 netif_rx(skb); 1864 } 1865 } 1866 return; 1867 1868 err: 1869 kfree_skb(skb); 1870 ppp_receive_error(ppp); 1871 } 1872 1873 static struct sk_buff * 1874 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb) 1875 { 1876 int proto = PPP_PROTO(skb); 1877 struct sk_buff *ns; 1878 int len; 1879 1880 /* Until we fix all the decompressor's need to make sure 1881 * data portion is linear. 1882 */ 1883 if (!pskb_may_pull(skb, skb->len)) 1884 goto err; 1885 1886 if (proto == PPP_COMP) { 1887 int obuff_size; 1888 1889 switch(ppp->rcomp->compress_proto) { 1890 case CI_MPPE: 1891 obuff_size = ppp->mru + PPP_HDRLEN + 1; 1892 break; 1893 default: 1894 obuff_size = ppp->mru + PPP_HDRLEN; 1895 break; 1896 } 1897 1898 ns = dev_alloc_skb(obuff_size); 1899 if (!ns) { 1900 netdev_err(ppp->dev, "ppp_decompress_frame: " 1901 "no memory\n"); 1902 goto err; 1903 } 1904 /* the decompressor still expects the A/C bytes in the hdr */ 1905 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2, 1906 skb->len + 2, ns->data, obuff_size); 1907 if (len < 0) { 1908 /* Pass the compressed frame to pppd as an 1909 error indication. */ 1910 if (len == DECOMP_FATALERROR) 1911 ppp->rstate |= SC_DC_FERROR; 1912 kfree_skb(ns); 1913 goto err; 1914 } 1915 1916 consume_skb(skb); 1917 skb = ns; 1918 skb_put(skb, len); 1919 skb_pull(skb, 2); /* pull off the A/C bytes */ 1920 1921 } else { 1922 /* Uncompressed frame - pass to decompressor so it 1923 can update its dictionary if necessary. */ 1924 if (ppp->rcomp->incomp) 1925 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2, 1926 skb->len + 2); 1927 } 1928 1929 return skb; 1930 1931 err: 1932 ppp->rstate |= SC_DC_ERROR; 1933 ppp_receive_error(ppp); 1934 return skb; 1935 } 1936 1937 #ifdef CONFIG_PPP_MULTILINK 1938 /* 1939 * Receive a multilink frame. 1940 * We put it on the reconstruction queue and then pull off 1941 * as many completed frames as we can. 1942 */ 1943 static void 1944 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1945 { 1946 u32 mask, seq; 1947 struct channel *ch; 1948 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1949 1950 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0) 1951 goto err; /* no good, throw it away */ 1952 1953 /* Decode sequence number and begin/end bits */ 1954 if (ppp->flags & SC_MP_SHORTSEQ) { 1955 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3]; 1956 mask = 0xfff; 1957 } else { 1958 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5]; 1959 mask = 0xffffff; 1960 } 1961 PPP_MP_CB(skb)->BEbits = skb->data[2]; 1962 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */ 1963 1964 /* 1965 * Do protocol ID decompression on the first fragment of each packet. 1966 */ 1967 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1)) 1968 *skb_push(skb, 1) = 0; 1969 1970 /* 1971 * Expand sequence number to 32 bits, making it as close 1972 * as possible to ppp->minseq. 1973 */ 1974 seq |= ppp->minseq & ~mask; 1975 if ((int)(ppp->minseq - seq) > (int)(mask >> 1)) 1976 seq += mask + 1; 1977 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1)) 1978 seq -= mask + 1; /* should never happen */ 1979 PPP_MP_CB(skb)->sequence = seq; 1980 pch->lastseq = seq; 1981 1982 /* 1983 * If this packet comes before the next one we were expecting, 1984 * drop it. 1985 */ 1986 if (seq_before(seq, ppp->nextseq)) { 1987 kfree_skb(skb); 1988 ++ppp->dev->stats.rx_dropped; 1989 ppp_receive_error(ppp); 1990 return; 1991 } 1992 1993 /* 1994 * Reevaluate minseq, the minimum over all channels of the 1995 * last sequence number received on each channel. Because of 1996 * the increasing sequence number rule, we know that any fragment 1997 * before `minseq' which hasn't arrived is never going to arrive. 1998 * The list of channels can't change because we have the receive 1999 * side of the ppp unit locked. 2000 */ 2001 list_for_each_entry(ch, &ppp->channels, clist) { 2002 if (seq_before(ch->lastseq, seq)) 2003 seq = ch->lastseq; 2004 } 2005 if (seq_before(ppp->minseq, seq)) 2006 ppp->minseq = seq; 2007 2008 /* Put the fragment on the reconstruction queue */ 2009 ppp_mp_insert(ppp, skb); 2010 2011 /* If the queue is getting long, don't wait any longer for packets 2012 before the start of the queue. */ 2013 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) { 2014 struct sk_buff *mskb = skb_peek(&ppp->mrq); 2015 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence)) 2016 ppp->minseq = PPP_MP_CB(mskb)->sequence; 2017 } 2018 2019 /* Pull completed packets off the queue and receive them. */ 2020 while ((skb = ppp_mp_reconstruct(ppp))) { 2021 if (pskb_may_pull(skb, 2)) 2022 ppp_receive_nonmp_frame(ppp, skb); 2023 else { 2024 ++ppp->dev->stats.rx_length_errors; 2025 kfree_skb(skb); 2026 ppp_receive_error(ppp); 2027 } 2028 } 2029 2030 return; 2031 2032 err: 2033 kfree_skb(skb); 2034 ppp_receive_error(ppp); 2035 } 2036 2037 /* 2038 * Insert a fragment on the MP reconstruction queue. 2039 * The queue is ordered by increasing sequence number. 2040 */ 2041 static void 2042 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb) 2043 { 2044 struct sk_buff *p; 2045 struct sk_buff_head *list = &ppp->mrq; 2046 u32 seq = PPP_MP_CB(skb)->sequence; 2047 2048 /* N.B. we don't need to lock the list lock because we have the 2049 ppp unit receive-side lock. */ 2050 skb_queue_walk(list, p) { 2051 if (seq_before(seq, PPP_MP_CB(p)->sequence)) 2052 break; 2053 } 2054 __skb_queue_before(list, p, skb); 2055 } 2056 2057 /* 2058 * Reconstruct a packet from the MP fragment queue. 2059 * We go through increasing sequence numbers until we find a 2060 * complete packet, or we get to the sequence number for a fragment 2061 * which hasn't arrived but might still do so. 2062 */ 2063 static struct sk_buff * 2064 ppp_mp_reconstruct(struct ppp *ppp) 2065 { 2066 u32 seq = ppp->nextseq; 2067 u32 minseq = ppp->minseq; 2068 struct sk_buff_head *list = &ppp->mrq; 2069 struct sk_buff *p, *tmp; 2070 struct sk_buff *head, *tail; 2071 struct sk_buff *skb = NULL; 2072 int lost = 0, len = 0; 2073 2074 if (ppp->mrru == 0) /* do nothing until mrru is set */ 2075 return NULL; 2076 head = list->next; 2077 tail = NULL; 2078 skb_queue_walk_safe(list, p, tmp) { 2079 again: 2080 if (seq_before(PPP_MP_CB(p)->sequence, seq)) { 2081 /* this can't happen, anyway ignore the skb */ 2082 netdev_err(ppp->dev, "ppp_mp_reconstruct bad " 2083 "seq %u < %u\n", 2084 PPP_MP_CB(p)->sequence, seq); 2085 __skb_unlink(p, list); 2086 kfree_skb(p); 2087 continue; 2088 } 2089 if (PPP_MP_CB(p)->sequence != seq) { 2090 u32 oldseq; 2091 /* Fragment `seq' is missing. If it is after 2092 minseq, it might arrive later, so stop here. */ 2093 if (seq_after(seq, minseq)) 2094 break; 2095 /* Fragment `seq' is lost, keep going. */ 2096 lost = 1; 2097 oldseq = seq; 2098 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)? 2099 minseq + 1: PPP_MP_CB(p)->sequence; 2100 2101 if (ppp->debug & 1) 2102 netdev_printk(KERN_DEBUG, ppp->dev, 2103 "lost frag %u..%u\n", 2104 oldseq, seq-1); 2105 2106 goto again; 2107 } 2108 2109 /* 2110 * At this point we know that all the fragments from 2111 * ppp->nextseq to seq are either present or lost. 2112 * Also, there are no complete packets in the queue 2113 * that have no missing fragments and end before this 2114 * fragment. 2115 */ 2116 2117 /* B bit set indicates this fragment starts a packet */ 2118 if (PPP_MP_CB(p)->BEbits & B) { 2119 head = p; 2120 lost = 0; 2121 len = 0; 2122 } 2123 2124 len += p->len; 2125 2126 /* Got a complete packet yet? */ 2127 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) && 2128 (PPP_MP_CB(head)->BEbits & B)) { 2129 if (len > ppp->mrru + 2) { 2130 ++ppp->dev->stats.rx_length_errors; 2131 netdev_printk(KERN_DEBUG, ppp->dev, 2132 "PPP: reconstructed packet" 2133 " is too long (%d)\n", len); 2134 } else { 2135 tail = p; 2136 break; 2137 } 2138 ppp->nextseq = seq + 1; 2139 } 2140 2141 /* 2142 * If this is the ending fragment of a packet, 2143 * and we haven't found a complete valid packet yet, 2144 * we can discard up to and including this fragment. 2145 */ 2146 if (PPP_MP_CB(p)->BEbits & E) { 2147 struct sk_buff *tmp2; 2148 2149 skb_queue_reverse_walk_from_safe(list, p, tmp2) { 2150 if (ppp->debug & 1) 2151 netdev_printk(KERN_DEBUG, ppp->dev, 2152 "discarding frag %u\n", 2153 PPP_MP_CB(p)->sequence); 2154 __skb_unlink(p, list); 2155 kfree_skb(p); 2156 } 2157 head = skb_peek(list); 2158 if (!head) 2159 break; 2160 } 2161 ++seq; 2162 } 2163 2164 /* If we have a complete packet, copy it all into one skb. */ 2165 if (tail != NULL) { 2166 /* If we have discarded any fragments, 2167 signal a receive error. */ 2168 if (PPP_MP_CB(head)->sequence != ppp->nextseq) { 2169 skb_queue_walk_safe(list, p, tmp) { 2170 if (p == head) 2171 break; 2172 if (ppp->debug & 1) 2173 netdev_printk(KERN_DEBUG, ppp->dev, 2174 "discarding frag %u\n", 2175 PPP_MP_CB(p)->sequence); 2176 __skb_unlink(p, list); 2177 kfree_skb(p); 2178 } 2179 2180 if (ppp->debug & 1) 2181 netdev_printk(KERN_DEBUG, ppp->dev, 2182 " missed pkts %u..%u\n", 2183 ppp->nextseq, 2184 PPP_MP_CB(head)->sequence-1); 2185 ++ppp->dev->stats.rx_dropped; 2186 ppp_receive_error(ppp); 2187 } 2188 2189 skb = head; 2190 if (head != tail) { 2191 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list; 2192 p = skb_queue_next(list, head); 2193 __skb_unlink(skb, list); 2194 skb_queue_walk_from_safe(list, p, tmp) { 2195 __skb_unlink(p, list); 2196 *fragpp = p; 2197 p->next = NULL; 2198 fragpp = &p->next; 2199 2200 skb->len += p->len; 2201 skb->data_len += p->len; 2202 skb->truesize += p->truesize; 2203 2204 if (p == tail) 2205 break; 2206 } 2207 } else { 2208 __skb_unlink(skb, list); 2209 } 2210 2211 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1; 2212 } 2213 2214 return skb; 2215 } 2216 #endif /* CONFIG_PPP_MULTILINK */ 2217 2218 /* 2219 * Channel interface. 2220 */ 2221 2222 /* Create a new, unattached ppp channel. */ 2223 int ppp_register_channel(struct ppp_channel *chan) 2224 { 2225 return ppp_register_net_channel(current->nsproxy->net_ns, chan); 2226 } 2227 2228 /* Create a new, unattached ppp channel for specified net. */ 2229 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan) 2230 { 2231 struct channel *pch; 2232 struct ppp_net *pn; 2233 2234 pch = kzalloc(sizeof(struct channel), GFP_KERNEL); 2235 if (!pch) 2236 return -ENOMEM; 2237 2238 pn = ppp_pernet(net); 2239 2240 pch->ppp = NULL; 2241 pch->chan = chan; 2242 pch->chan_net = net; 2243 chan->ppp = pch; 2244 init_ppp_file(&pch->file, CHANNEL); 2245 pch->file.hdrlen = chan->hdrlen; 2246 #ifdef CONFIG_PPP_MULTILINK 2247 pch->lastseq = -1; 2248 #endif /* CONFIG_PPP_MULTILINK */ 2249 init_rwsem(&pch->chan_sem); 2250 spin_lock_init(&pch->downl); 2251 rwlock_init(&pch->upl); 2252 2253 spin_lock_bh(&pn->all_channels_lock); 2254 pch->file.index = ++pn->last_channel_index; 2255 list_add(&pch->list, &pn->new_channels); 2256 atomic_inc(&channel_count); 2257 spin_unlock_bh(&pn->all_channels_lock); 2258 2259 return 0; 2260 } 2261 2262 /* 2263 * Return the index of a channel. 2264 */ 2265 int ppp_channel_index(struct ppp_channel *chan) 2266 { 2267 struct channel *pch = chan->ppp; 2268 2269 if (pch) 2270 return pch->file.index; 2271 return -1; 2272 } 2273 2274 /* 2275 * Return the PPP unit number to which a channel is connected. 2276 */ 2277 int ppp_unit_number(struct ppp_channel *chan) 2278 { 2279 struct channel *pch = chan->ppp; 2280 int unit = -1; 2281 2282 if (pch) { 2283 read_lock_bh(&pch->upl); 2284 if (pch->ppp) 2285 unit = pch->ppp->file.index; 2286 read_unlock_bh(&pch->upl); 2287 } 2288 return unit; 2289 } 2290 2291 /* 2292 * Return the PPP device interface name of a channel. 2293 */ 2294 char *ppp_dev_name(struct ppp_channel *chan) 2295 { 2296 struct channel *pch = chan->ppp; 2297 char *name = NULL; 2298 2299 if (pch) { 2300 read_lock_bh(&pch->upl); 2301 if (pch->ppp && pch->ppp->dev) 2302 name = pch->ppp->dev->name; 2303 read_unlock_bh(&pch->upl); 2304 } 2305 return name; 2306 } 2307 2308 2309 /* 2310 * Disconnect a channel from the generic layer. 2311 * This must be called in process context. 2312 */ 2313 void 2314 ppp_unregister_channel(struct ppp_channel *chan) 2315 { 2316 struct channel *pch = chan->ppp; 2317 struct ppp_net *pn; 2318 2319 if (!pch) 2320 return; /* should never happen */ 2321 2322 chan->ppp = NULL; 2323 2324 /* 2325 * This ensures that we have returned from any calls into the 2326 * the channel's start_xmit or ioctl routine before we proceed. 2327 */ 2328 down_write(&pch->chan_sem); 2329 spin_lock_bh(&pch->downl); 2330 pch->chan = NULL; 2331 spin_unlock_bh(&pch->downl); 2332 up_write(&pch->chan_sem); 2333 ppp_disconnect_channel(pch); 2334 2335 pn = ppp_pernet(pch->chan_net); 2336 spin_lock_bh(&pn->all_channels_lock); 2337 list_del(&pch->list); 2338 spin_unlock_bh(&pn->all_channels_lock); 2339 2340 pch->file.dead = 1; 2341 wake_up_interruptible(&pch->file.rwait); 2342 if (atomic_dec_and_test(&pch->file.refcnt)) 2343 ppp_destroy_channel(pch); 2344 } 2345 2346 /* 2347 * Callback from a channel when it can accept more to transmit. 2348 * This should be called at BH/softirq level, not interrupt level. 2349 */ 2350 void 2351 ppp_output_wakeup(struct ppp_channel *chan) 2352 { 2353 struct channel *pch = chan->ppp; 2354 2355 if (!pch) 2356 return; 2357 ppp_channel_push(pch); 2358 } 2359 2360 /* 2361 * Compression control. 2362 */ 2363 2364 /* Process the PPPIOCSCOMPRESS ioctl. */ 2365 static int 2366 ppp_set_compress(struct ppp *ppp, unsigned long arg) 2367 { 2368 int err; 2369 struct compressor *cp, *ocomp; 2370 struct ppp_option_data data; 2371 void *state, *ostate; 2372 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH]; 2373 2374 err = -EFAULT; 2375 if (copy_from_user(&data, (void __user *) arg, sizeof(data)) || 2376 (data.length <= CCP_MAX_OPTION_LENGTH && 2377 copy_from_user(ccp_option, (void __user *) data.ptr, data.length))) 2378 goto out; 2379 err = -EINVAL; 2380 if (data.length > CCP_MAX_OPTION_LENGTH || 2381 ccp_option[1] < 2 || ccp_option[1] > data.length) 2382 goto out; 2383 2384 cp = try_then_request_module( 2385 find_compressor(ccp_option[0]), 2386 "ppp-compress-%d", ccp_option[0]); 2387 if (!cp) 2388 goto out; 2389 2390 err = -ENOBUFS; 2391 if (data.transmit) { 2392 state = cp->comp_alloc(ccp_option, data.length); 2393 if (state) { 2394 ppp_xmit_lock(ppp); 2395 ppp->xstate &= ~SC_COMP_RUN; 2396 ocomp = ppp->xcomp; 2397 ostate = ppp->xc_state; 2398 ppp->xcomp = cp; 2399 ppp->xc_state = state; 2400 ppp_xmit_unlock(ppp); 2401 if (ostate) { 2402 ocomp->comp_free(ostate); 2403 module_put(ocomp->owner); 2404 } 2405 err = 0; 2406 } else 2407 module_put(cp->owner); 2408 2409 } else { 2410 state = cp->decomp_alloc(ccp_option, data.length); 2411 if (state) { 2412 ppp_recv_lock(ppp); 2413 ppp->rstate &= ~SC_DECOMP_RUN; 2414 ocomp = ppp->rcomp; 2415 ostate = ppp->rc_state; 2416 ppp->rcomp = cp; 2417 ppp->rc_state = state; 2418 ppp_recv_unlock(ppp); 2419 if (ostate) { 2420 ocomp->decomp_free(ostate); 2421 module_put(ocomp->owner); 2422 } 2423 err = 0; 2424 } else 2425 module_put(cp->owner); 2426 } 2427 2428 out: 2429 return err; 2430 } 2431 2432 /* 2433 * Look at a CCP packet and update our state accordingly. 2434 * We assume the caller has the xmit or recv path locked. 2435 */ 2436 static void 2437 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound) 2438 { 2439 unsigned char *dp; 2440 int len; 2441 2442 if (!pskb_may_pull(skb, CCP_HDRLEN + 2)) 2443 return; /* no header */ 2444 dp = skb->data + 2; 2445 2446 switch (CCP_CODE(dp)) { 2447 case CCP_CONFREQ: 2448 2449 /* A ConfReq starts negotiation of compression 2450 * in one direction of transmission, 2451 * and hence brings it down...but which way? 2452 * 2453 * Remember: 2454 * A ConfReq indicates what the sender would like to receive 2455 */ 2456 if(inbound) 2457 /* He is proposing what I should send */ 2458 ppp->xstate &= ~SC_COMP_RUN; 2459 else 2460 /* I am proposing to what he should send */ 2461 ppp->rstate &= ~SC_DECOMP_RUN; 2462 2463 break; 2464 2465 case CCP_TERMREQ: 2466 case CCP_TERMACK: 2467 /* 2468 * CCP is going down, both directions of transmission 2469 */ 2470 ppp->rstate &= ~SC_DECOMP_RUN; 2471 ppp->xstate &= ~SC_COMP_RUN; 2472 break; 2473 2474 case CCP_CONFACK: 2475 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN) 2476 break; 2477 len = CCP_LENGTH(dp); 2478 if (!pskb_may_pull(skb, len + 2)) 2479 return; /* too short */ 2480 dp += CCP_HDRLEN; 2481 len -= CCP_HDRLEN; 2482 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp)) 2483 break; 2484 if (inbound) { 2485 /* we will start receiving compressed packets */ 2486 if (!ppp->rc_state) 2487 break; 2488 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len, 2489 ppp->file.index, 0, ppp->mru, ppp->debug)) { 2490 ppp->rstate |= SC_DECOMP_RUN; 2491 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR); 2492 } 2493 } else { 2494 /* we will soon start sending compressed packets */ 2495 if (!ppp->xc_state) 2496 break; 2497 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len, 2498 ppp->file.index, 0, ppp->debug)) 2499 ppp->xstate |= SC_COMP_RUN; 2500 } 2501 break; 2502 2503 case CCP_RESETACK: 2504 /* reset the [de]compressor */ 2505 if ((ppp->flags & SC_CCP_UP) == 0) 2506 break; 2507 if (inbound) { 2508 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) { 2509 ppp->rcomp->decomp_reset(ppp->rc_state); 2510 ppp->rstate &= ~SC_DC_ERROR; 2511 } 2512 } else { 2513 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN)) 2514 ppp->xcomp->comp_reset(ppp->xc_state); 2515 } 2516 break; 2517 } 2518 } 2519 2520 /* Free up compression resources. */ 2521 static void 2522 ppp_ccp_closed(struct ppp *ppp) 2523 { 2524 void *xstate, *rstate; 2525 struct compressor *xcomp, *rcomp; 2526 2527 ppp_lock(ppp); 2528 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP); 2529 ppp->xstate = 0; 2530 xcomp = ppp->xcomp; 2531 xstate = ppp->xc_state; 2532 ppp->xc_state = NULL; 2533 ppp->rstate = 0; 2534 rcomp = ppp->rcomp; 2535 rstate = ppp->rc_state; 2536 ppp->rc_state = NULL; 2537 ppp_unlock(ppp); 2538 2539 if (xstate) { 2540 xcomp->comp_free(xstate); 2541 module_put(xcomp->owner); 2542 } 2543 if (rstate) { 2544 rcomp->decomp_free(rstate); 2545 module_put(rcomp->owner); 2546 } 2547 } 2548 2549 /* List of compressors. */ 2550 static LIST_HEAD(compressor_list); 2551 static DEFINE_SPINLOCK(compressor_list_lock); 2552 2553 struct compressor_entry { 2554 struct list_head list; 2555 struct compressor *comp; 2556 }; 2557 2558 static struct compressor_entry * 2559 find_comp_entry(int proto) 2560 { 2561 struct compressor_entry *ce; 2562 2563 list_for_each_entry(ce, &compressor_list, list) { 2564 if (ce->comp->compress_proto == proto) 2565 return ce; 2566 } 2567 return NULL; 2568 } 2569 2570 /* Register a compressor */ 2571 int 2572 ppp_register_compressor(struct compressor *cp) 2573 { 2574 struct compressor_entry *ce; 2575 int ret; 2576 spin_lock(&compressor_list_lock); 2577 ret = -EEXIST; 2578 if (find_comp_entry(cp->compress_proto)) 2579 goto out; 2580 ret = -ENOMEM; 2581 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC); 2582 if (!ce) 2583 goto out; 2584 ret = 0; 2585 ce->comp = cp; 2586 list_add(&ce->list, &compressor_list); 2587 out: 2588 spin_unlock(&compressor_list_lock); 2589 return ret; 2590 } 2591 2592 /* Unregister a compressor */ 2593 void 2594 ppp_unregister_compressor(struct compressor *cp) 2595 { 2596 struct compressor_entry *ce; 2597 2598 spin_lock(&compressor_list_lock); 2599 ce = find_comp_entry(cp->compress_proto); 2600 if (ce && ce->comp == cp) { 2601 list_del(&ce->list); 2602 kfree(ce); 2603 } 2604 spin_unlock(&compressor_list_lock); 2605 } 2606 2607 /* Find a compressor. */ 2608 static struct compressor * 2609 find_compressor(int type) 2610 { 2611 struct compressor_entry *ce; 2612 struct compressor *cp = NULL; 2613 2614 spin_lock(&compressor_list_lock); 2615 ce = find_comp_entry(type); 2616 if (ce) { 2617 cp = ce->comp; 2618 if (!try_module_get(cp->owner)) 2619 cp = NULL; 2620 } 2621 spin_unlock(&compressor_list_lock); 2622 return cp; 2623 } 2624 2625 /* 2626 * Miscelleneous stuff. 2627 */ 2628 2629 static void 2630 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st) 2631 { 2632 struct slcompress *vj = ppp->vj; 2633 2634 memset(st, 0, sizeof(*st)); 2635 st->p.ppp_ipackets = ppp->stats64.rx_packets; 2636 st->p.ppp_ierrors = ppp->dev->stats.rx_errors; 2637 st->p.ppp_ibytes = ppp->stats64.rx_bytes; 2638 st->p.ppp_opackets = ppp->stats64.tx_packets; 2639 st->p.ppp_oerrors = ppp->dev->stats.tx_errors; 2640 st->p.ppp_obytes = ppp->stats64.tx_bytes; 2641 if (!vj) 2642 return; 2643 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed; 2644 st->vj.vjs_compressed = vj->sls_o_compressed; 2645 st->vj.vjs_searches = vj->sls_o_searches; 2646 st->vj.vjs_misses = vj->sls_o_misses; 2647 st->vj.vjs_errorin = vj->sls_i_error; 2648 st->vj.vjs_tossed = vj->sls_i_tossed; 2649 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed; 2650 st->vj.vjs_compressedin = vj->sls_i_compressed; 2651 } 2652 2653 /* 2654 * Stuff for handling the lists of ppp units and channels 2655 * and for initialization. 2656 */ 2657 2658 /* 2659 * Create a new ppp interface unit. Fails if it can't allocate memory 2660 * or if there is already a unit with the requested number. 2661 * unit == -1 means allocate a new number. 2662 */ 2663 static struct ppp * 2664 ppp_create_interface(struct net *net, int unit, int *retp) 2665 { 2666 struct ppp *ppp; 2667 struct ppp_net *pn; 2668 struct net_device *dev = NULL; 2669 int ret = -ENOMEM; 2670 int i; 2671 2672 dev = alloc_netdev(sizeof(struct ppp), "", ppp_setup); 2673 if (!dev) 2674 goto out1; 2675 2676 pn = ppp_pernet(net); 2677 2678 ppp = netdev_priv(dev); 2679 ppp->dev = dev; 2680 ppp->mru = PPP_MRU; 2681 init_ppp_file(&ppp->file, INTERFACE); 2682 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */ 2683 for (i = 0; i < NUM_NP; ++i) 2684 ppp->npmode[i] = NPMODE_PASS; 2685 INIT_LIST_HEAD(&ppp->channels); 2686 spin_lock_init(&ppp->rlock); 2687 spin_lock_init(&ppp->wlock); 2688 #ifdef CONFIG_PPP_MULTILINK 2689 ppp->minseq = -1; 2690 skb_queue_head_init(&ppp->mrq); 2691 #endif /* CONFIG_PPP_MULTILINK */ 2692 #ifdef CONFIG_PPP_FILTER 2693 ppp->pass_filter = NULL; 2694 ppp->active_filter = NULL; 2695 #endif /* CONFIG_PPP_FILTER */ 2696 2697 /* 2698 * drum roll: don't forget to set 2699 * the net device is belong to 2700 */ 2701 dev_net_set(dev, net); 2702 2703 mutex_lock(&pn->all_ppp_mutex); 2704 2705 if (unit < 0) { 2706 unit = unit_get(&pn->units_idr, ppp); 2707 if (unit < 0) { 2708 ret = unit; 2709 goto out2; 2710 } 2711 } else { 2712 ret = -EEXIST; 2713 if (unit_find(&pn->units_idr, unit)) 2714 goto out2; /* unit already exists */ 2715 /* 2716 * if caller need a specified unit number 2717 * lets try to satisfy him, otherwise -- 2718 * he should better ask us for new unit number 2719 * 2720 * NOTE: yes I know that returning EEXIST it's not 2721 * fair but at least pppd will ask us to allocate 2722 * new unit in this case so user is happy :) 2723 */ 2724 unit = unit_set(&pn->units_idr, ppp, unit); 2725 if (unit < 0) 2726 goto out2; 2727 } 2728 2729 /* Initialize the new ppp unit */ 2730 ppp->file.index = unit; 2731 sprintf(dev->name, "ppp%d", unit); 2732 2733 ret = register_netdev(dev); 2734 if (ret != 0) { 2735 unit_put(&pn->units_idr, unit); 2736 netdev_err(ppp->dev, "PPP: couldn't register device %s (%d)\n", 2737 dev->name, ret); 2738 goto out2; 2739 } 2740 2741 ppp->ppp_net = net; 2742 2743 atomic_inc(&ppp_unit_count); 2744 mutex_unlock(&pn->all_ppp_mutex); 2745 2746 *retp = 0; 2747 return ppp; 2748 2749 out2: 2750 mutex_unlock(&pn->all_ppp_mutex); 2751 free_netdev(dev); 2752 out1: 2753 *retp = ret; 2754 return NULL; 2755 } 2756 2757 /* 2758 * Initialize a ppp_file structure. 2759 */ 2760 static void 2761 init_ppp_file(struct ppp_file *pf, int kind) 2762 { 2763 pf->kind = kind; 2764 skb_queue_head_init(&pf->xq); 2765 skb_queue_head_init(&pf->rq); 2766 atomic_set(&pf->refcnt, 1); 2767 init_waitqueue_head(&pf->rwait); 2768 } 2769 2770 /* 2771 * Take down a ppp interface unit - called when the owning file 2772 * (the one that created the unit) is closed or detached. 2773 */ 2774 static void ppp_shutdown_interface(struct ppp *ppp) 2775 { 2776 struct ppp_net *pn; 2777 2778 pn = ppp_pernet(ppp->ppp_net); 2779 mutex_lock(&pn->all_ppp_mutex); 2780 2781 /* This will call dev_close() for us. */ 2782 ppp_lock(ppp); 2783 if (!ppp->closing) { 2784 ppp->closing = 1; 2785 ppp_unlock(ppp); 2786 unregister_netdev(ppp->dev); 2787 unit_put(&pn->units_idr, ppp->file.index); 2788 } else 2789 ppp_unlock(ppp); 2790 2791 ppp->file.dead = 1; 2792 ppp->owner = NULL; 2793 wake_up_interruptible(&ppp->file.rwait); 2794 2795 mutex_unlock(&pn->all_ppp_mutex); 2796 } 2797 2798 /* 2799 * Free the memory used by a ppp unit. This is only called once 2800 * there are no channels connected to the unit and no file structs 2801 * that reference the unit. 2802 */ 2803 static void ppp_destroy_interface(struct ppp *ppp) 2804 { 2805 atomic_dec(&ppp_unit_count); 2806 2807 if (!ppp->file.dead || ppp->n_channels) { 2808 /* "can't happen" */ 2809 netdev_err(ppp->dev, "ppp: destroying ppp struct %p " 2810 "but dead=%d n_channels=%d !\n", 2811 ppp, ppp->file.dead, ppp->n_channels); 2812 return; 2813 } 2814 2815 ppp_ccp_closed(ppp); 2816 if (ppp->vj) { 2817 slhc_free(ppp->vj); 2818 ppp->vj = NULL; 2819 } 2820 skb_queue_purge(&ppp->file.xq); 2821 skb_queue_purge(&ppp->file.rq); 2822 #ifdef CONFIG_PPP_MULTILINK 2823 skb_queue_purge(&ppp->mrq); 2824 #endif /* CONFIG_PPP_MULTILINK */ 2825 #ifdef CONFIG_PPP_FILTER 2826 if (ppp->pass_filter) { 2827 sk_unattached_filter_destroy(ppp->pass_filter); 2828 ppp->pass_filter = NULL; 2829 } 2830 2831 if (ppp->active_filter) { 2832 sk_unattached_filter_destroy(ppp->active_filter); 2833 ppp->active_filter = NULL; 2834 } 2835 #endif /* CONFIG_PPP_FILTER */ 2836 2837 kfree_skb(ppp->xmit_pending); 2838 2839 free_netdev(ppp->dev); 2840 } 2841 2842 /* 2843 * Locate an existing ppp unit. 2844 * The caller should have locked the all_ppp_mutex. 2845 */ 2846 static struct ppp * 2847 ppp_find_unit(struct ppp_net *pn, int unit) 2848 { 2849 return unit_find(&pn->units_idr, unit); 2850 } 2851 2852 /* 2853 * Locate an existing ppp channel. 2854 * The caller should have locked the all_channels_lock. 2855 * First we look in the new_channels list, then in the 2856 * all_channels list. If found in the new_channels list, 2857 * we move it to the all_channels list. This is for speed 2858 * when we have a lot of channels in use. 2859 */ 2860 static struct channel * 2861 ppp_find_channel(struct ppp_net *pn, int unit) 2862 { 2863 struct channel *pch; 2864 2865 list_for_each_entry(pch, &pn->new_channels, list) { 2866 if (pch->file.index == unit) { 2867 list_move(&pch->list, &pn->all_channels); 2868 return pch; 2869 } 2870 } 2871 2872 list_for_each_entry(pch, &pn->all_channels, list) { 2873 if (pch->file.index == unit) 2874 return pch; 2875 } 2876 2877 return NULL; 2878 } 2879 2880 /* 2881 * Connect a PPP channel to a PPP interface unit. 2882 */ 2883 static int 2884 ppp_connect_channel(struct channel *pch, int unit) 2885 { 2886 struct ppp *ppp; 2887 struct ppp_net *pn; 2888 int ret = -ENXIO; 2889 int hdrlen; 2890 2891 pn = ppp_pernet(pch->chan_net); 2892 2893 mutex_lock(&pn->all_ppp_mutex); 2894 ppp = ppp_find_unit(pn, unit); 2895 if (!ppp) 2896 goto out; 2897 write_lock_bh(&pch->upl); 2898 ret = -EINVAL; 2899 if (pch->ppp) 2900 goto outl; 2901 2902 ppp_lock(ppp); 2903 if (pch->file.hdrlen > ppp->file.hdrlen) 2904 ppp->file.hdrlen = pch->file.hdrlen; 2905 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */ 2906 if (hdrlen > ppp->dev->hard_header_len) 2907 ppp->dev->hard_header_len = hdrlen; 2908 list_add_tail(&pch->clist, &ppp->channels); 2909 ++ppp->n_channels; 2910 pch->ppp = ppp; 2911 atomic_inc(&ppp->file.refcnt); 2912 ppp_unlock(ppp); 2913 ret = 0; 2914 2915 outl: 2916 write_unlock_bh(&pch->upl); 2917 out: 2918 mutex_unlock(&pn->all_ppp_mutex); 2919 return ret; 2920 } 2921 2922 /* 2923 * Disconnect a channel from its ppp unit. 2924 */ 2925 static int 2926 ppp_disconnect_channel(struct channel *pch) 2927 { 2928 struct ppp *ppp; 2929 int err = -EINVAL; 2930 2931 write_lock_bh(&pch->upl); 2932 ppp = pch->ppp; 2933 pch->ppp = NULL; 2934 write_unlock_bh(&pch->upl); 2935 if (ppp) { 2936 /* remove it from the ppp unit's list */ 2937 ppp_lock(ppp); 2938 list_del(&pch->clist); 2939 if (--ppp->n_channels == 0) 2940 wake_up_interruptible(&ppp->file.rwait); 2941 ppp_unlock(ppp); 2942 if (atomic_dec_and_test(&ppp->file.refcnt)) 2943 ppp_destroy_interface(ppp); 2944 err = 0; 2945 } 2946 return err; 2947 } 2948 2949 /* 2950 * Free up the resources used by a ppp channel. 2951 */ 2952 static void ppp_destroy_channel(struct channel *pch) 2953 { 2954 atomic_dec(&channel_count); 2955 2956 if (!pch->file.dead) { 2957 /* "can't happen" */ 2958 pr_err("ppp: destroying undead channel %p !\n", pch); 2959 return; 2960 } 2961 skb_queue_purge(&pch->file.xq); 2962 skb_queue_purge(&pch->file.rq); 2963 kfree(pch); 2964 } 2965 2966 static void __exit ppp_cleanup(void) 2967 { 2968 /* should never happen */ 2969 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count)) 2970 pr_err("PPP: removing module but units remain!\n"); 2971 unregister_chrdev(PPP_MAJOR, "ppp"); 2972 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0)); 2973 class_destroy(ppp_class); 2974 unregister_pernet_device(&ppp_net_ops); 2975 } 2976 2977 /* 2978 * Units handling. Caller must protect concurrent access 2979 * by holding all_ppp_mutex 2980 */ 2981 2982 /* associate pointer with specified number */ 2983 static int unit_set(struct idr *p, void *ptr, int n) 2984 { 2985 int unit; 2986 2987 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL); 2988 if (unit == -ENOSPC) 2989 unit = -EINVAL; 2990 return unit; 2991 } 2992 2993 /* get new free unit number and associate pointer with it */ 2994 static int unit_get(struct idr *p, void *ptr) 2995 { 2996 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL); 2997 } 2998 2999 /* put unit number back to a pool */ 3000 static void unit_put(struct idr *p, int n) 3001 { 3002 idr_remove(p, n); 3003 } 3004 3005 /* get pointer associated with the number */ 3006 static void *unit_find(struct idr *p, int n) 3007 { 3008 return idr_find(p, n); 3009 } 3010 3011 /* Module/initialization stuff */ 3012 3013 module_init(ppp_init); 3014 module_exit(ppp_cleanup); 3015 3016 EXPORT_SYMBOL(ppp_register_net_channel); 3017 EXPORT_SYMBOL(ppp_register_channel); 3018 EXPORT_SYMBOL(ppp_unregister_channel); 3019 EXPORT_SYMBOL(ppp_channel_index); 3020 EXPORT_SYMBOL(ppp_unit_number); 3021 EXPORT_SYMBOL(ppp_dev_name); 3022 EXPORT_SYMBOL(ppp_input); 3023 EXPORT_SYMBOL(ppp_input_error); 3024 EXPORT_SYMBOL(ppp_output_wakeup); 3025 EXPORT_SYMBOL(ppp_register_compressor); 3026 EXPORT_SYMBOL(ppp_unregister_compressor); 3027 MODULE_LICENSE("GPL"); 3028 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0); 3029 MODULE_ALIAS("devname:ppp"); 3030