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 bpf_prog *pass_filter; /* filter for packets to pass */ 147 struct bpf_prog *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 #ifdef CONFIG_PPP_MULTILINK 659 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK)) 660 ppp->nextseq = 0; 661 #endif 662 ppp->flags = val & SC_FLAG_BITS; 663 ppp_unlock(ppp); 664 if (cflags & SC_CCP_OPEN) 665 ppp_ccp_closed(ppp); 666 err = 0; 667 break; 668 669 case PPPIOCGFLAGS: 670 val = ppp->flags | ppp->xstate | ppp->rstate; 671 if (put_user(val, p)) 672 break; 673 err = 0; 674 break; 675 676 case PPPIOCSCOMPRESS: 677 err = ppp_set_compress(ppp, arg); 678 break; 679 680 case PPPIOCGUNIT: 681 if (put_user(ppp->file.index, p)) 682 break; 683 err = 0; 684 break; 685 686 case PPPIOCSDEBUG: 687 if (get_user(val, p)) 688 break; 689 ppp->debug = val; 690 err = 0; 691 break; 692 693 case PPPIOCGDEBUG: 694 if (put_user(ppp->debug, p)) 695 break; 696 err = 0; 697 break; 698 699 case PPPIOCGIDLE: 700 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ; 701 idle.recv_idle = (jiffies - ppp->last_recv) / HZ; 702 if (copy_to_user(argp, &idle, sizeof(idle))) 703 break; 704 err = 0; 705 break; 706 707 case PPPIOCSMAXCID: 708 if (get_user(val, p)) 709 break; 710 val2 = 15; 711 if ((val >> 16) != 0) { 712 val2 = val >> 16; 713 val &= 0xffff; 714 } 715 vj = slhc_init(val2+1, val+1); 716 if (!vj) { 717 netdev_err(ppp->dev, 718 "PPP: no memory (VJ compressor)\n"); 719 err = -ENOMEM; 720 break; 721 } 722 ppp_lock(ppp); 723 if (ppp->vj) 724 slhc_free(ppp->vj); 725 ppp->vj = vj; 726 ppp_unlock(ppp); 727 err = 0; 728 break; 729 730 case PPPIOCGNPMODE: 731 case PPPIOCSNPMODE: 732 if (copy_from_user(&npi, argp, sizeof(npi))) 733 break; 734 err = proto_to_npindex(npi.protocol); 735 if (err < 0) 736 break; 737 i = err; 738 if (cmd == PPPIOCGNPMODE) { 739 err = -EFAULT; 740 npi.mode = ppp->npmode[i]; 741 if (copy_to_user(argp, &npi, sizeof(npi))) 742 break; 743 } else { 744 ppp->npmode[i] = npi.mode; 745 /* we may be able to transmit more packets now (??) */ 746 netif_wake_queue(ppp->dev); 747 } 748 err = 0; 749 break; 750 751 #ifdef CONFIG_PPP_FILTER 752 case PPPIOCSPASS: 753 { 754 struct sock_filter *code; 755 756 err = get_filter(argp, &code); 757 if (err >= 0) { 758 struct sock_fprog_kern fprog = { 759 .len = err, 760 .filter = code, 761 }; 762 763 ppp_lock(ppp); 764 if (ppp->pass_filter) { 765 bpf_prog_destroy(ppp->pass_filter); 766 ppp->pass_filter = NULL; 767 } 768 if (fprog.filter != NULL) 769 err = bpf_prog_create(&ppp->pass_filter, 770 &fprog); 771 else 772 err = 0; 773 kfree(code); 774 ppp_unlock(ppp); 775 } 776 break; 777 } 778 case PPPIOCSACTIVE: 779 { 780 struct sock_filter *code; 781 782 err = get_filter(argp, &code); 783 if (err >= 0) { 784 struct sock_fprog_kern fprog = { 785 .len = err, 786 .filter = code, 787 }; 788 789 ppp_lock(ppp); 790 if (ppp->active_filter) { 791 bpf_prog_destroy(ppp->active_filter); 792 ppp->active_filter = NULL; 793 } 794 if (fprog.filter != NULL) 795 err = bpf_prog_create(&ppp->active_filter, 796 &fprog); 797 else 798 err = 0; 799 kfree(code); 800 ppp_unlock(ppp); 801 } 802 break; 803 } 804 #endif /* CONFIG_PPP_FILTER */ 805 806 #ifdef CONFIG_PPP_MULTILINK 807 case PPPIOCSMRRU: 808 if (get_user(val, p)) 809 break; 810 ppp_recv_lock(ppp); 811 ppp->mrru = val; 812 ppp_recv_unlock(ppp); 813 err = 0; 814 break; 815 #endif /* CONFIG_PPP_MULTILINK */ 816 817 default: 818 err = -ENOTTY; 819 } 820 mutex_unlock(&ppp_mutex); 821 return err; 822 } 823 824 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 825 struct file *file, unsigned int cmd, unsigned long arg) 826 { 827 int unit, err = -EFAULT; 828 struct ppp *ppp; 829 struct channel *chan; 830 struct ppp_net *pn; 831 int __user *p = (int __user *)arg; 832 833 mutex_lock(&ppp_mutex); 834 switch (cmd) { 835 case PPPIOCNEWUNIT: 836 /* Create a new ppp unit */ 837 if (get_user(unit, p)) 838 break; 839 ppp = ppp_create_interface(net, unit, &err); 840 if (!ppp) 841 break; 842 file->private_data = &ppp->file; 843 ppp->owner = file; 844 err = -EFAULT; 845 if (put_user(ppp->file.index, p)) 846 break; 847 err = 0; 848 break; 849 850 case PPPIOCATTACH: 851 /* Attach to an existing ppp unit */ 852 if (get_user(unit, p)) 853 break; 854 err = -ENXIO; 855 pn = ppp_pernet(net); 856 mutex_lock(&pn->all_ppp_mutex); 857 ppp = ppp_find_unit(pn, unit); 858 if (ppp) { 859 atomic_inc(&ppp->file.refcnt); 860 file->private_data = &ppp->file; 861 err = 0; 862 } 863 mutex_unlock(&pn->all_ppp_mutex); 864 break; 865 866 case PPPIOCATTCHAN: 867 if (get_user(unit, p)) 868 break; 869 err = -ENXIO; 870 pn = ppp_pernet(net); 871 spin_lock_bh(&pn->all_channels_lock); 872 chan = ppp_find_channel(pn, unit); 873 if (chan) { 874 atomic_inc(&chan->file.refcnt); 875 file->private_data = &chan->file; 876 err = 0; 877 } 878 spin_unlock_bh(&pn->all_channels_lock); 879 break; 880 881 default: 882 err = -ENOTTY; 883 } 884 mutex_unlock(&ppp_mutex); 885 return err; 886 } 887 888 static const struct file_operations ppp_device_fops = { 889 .owner = THIS_MODULE, 890 .read = ppp_read, 891 .write = ppp_write, 892 .poll = ppp_poll, 893 .unlocked_ioctl = ppp_ioctl, 894 .open = ppp_open, 895 .release = ppp_release, 896 .llseek = noop_llseek, 897 }; 898 899 static __net_init int ppp_init_net(struct net *net) 900 { 901 struct ppp_net *pn = net_generic(net, ppp_net_id); 902 903 idr_init(&pn->units_idr); 904 mutex_init(&pn->all_ppp_mutex); 905 906 INIT_LIST_HEAD(&pn->all_channels); 907 INIT_LIST_HEAD(&pn->new_channels); 908 909 spin_lock_init(&pn->all_channels_lock); 910 911 return 0; 912 } 913 914 static __net_exit void ppp_exit_net(struct net *net) 915 { 916 struct ppp_net *pn = net_generic(net, ppp_net_id); 917 918 idr_destroy(&pn->units_idr); 919 } 920 921 static struct pernet_operations ppp_net_ops = { 922 .init = ppp_init_net, 923 .exit = ppp_exit_net, 924 .id = &ppp_net_id, 925 .size = sizeof(struct ppp_net), 926 }; 927 928 #define PPP_MAJOR 108 929 930 /* Called at boot time if ppp is compiled into the kernel, 931 or at module load time (from init_module) if compiled as a module. */ 932 static int __init ppp_init(void) 933 { 934 int err; 935 936 pr_info("PPP generic driver version " PPP_VERSION "\n"); 937 938 err = register_pernet_device(&ppp_net_ops); 939 if (err) { 940 pr_err("failed to register PPP pernet device (%d)\n", err); 941 goto out; 942 } 943 944 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops); 945 if (err) { 946 pr_err("failed to register PPP device (%d)\n", err); 947 goto out_net; 948 } 949 950 ppp_class = class_create(THIS_MODULE, "ppp"); 951 if (IS_ERR(ppp_class)) { 952 err = PTR_ERR(ppp_class); 953 goto out_chrdev; 954 } 955 956 /* not a big deal if we fail here :-) */ 957 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp"); 958 959 return 0; 960 961 out_chrdev: 962 unregister_chrdev(PPP_MAJOR, "ppp"); 963 out_net: 964 unregister_pernet_device(&ppp_net_ops); 965 out: 966 return err; 967 } 968 969 /* 970 * Network interface unit routines. 971 */ 972 static netdev_tx_t 973 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev) 974 { 975 struct ppp *ppp = netdev_priv(dev); 976 int npi, proto; 977 unsigned char *pp; 978 979 npi = ethertype_to_npindex(ntohs(skb->protocol)); 980 if (npi < 0) 981 goto outf; 982 983 /* Drop, accept or reject the packet */ 984 switch (ppp->npmode[npi]) { 985 case NPMODE_PASS: 986 break; 987 case NPMODE_QUEUE: 988 /* it would be nice to have a way to tell the network 989 system to queue this one up for later. */ 990 goto outf; 991 case NPMODE_DROP: 992 case NPMODE_ERROR: 993 goto outf; 994 } 995 996 /* Put the 2-byte PPP protocol number on the front, 997 making sure there is room for the address and control fields. */ 998 if (skb_cow_head(skb, PPP_HDRLEN)) 999 goto outf; 1000 1001 pp = skb_push(skb, 2); 1002 proto = npindex_to_proto[npi]; 1003 put_unaligned_be16(proto, pp); 1004 1005 skb_queue_tail(&ppp->file.xq, skb); 1006 ppp_xmit_process(ppp); 1007 return NETDEV_TX_OK; 1008 1009 outf: 1010 kfree_skb(skb); 1011 ++dev->stats.tx_dropped; 1012 return NETDEV_TX_OK; 1013 } 1014 1015 static int 1016 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 1017 { 1018 struct ppp *ppp = netdev_priv(dev); 1019 int err = -EFAULT; 1020 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data; 1021 struct ppp_stats stats; 1022 struct ppp_comp_stats cstats; 1023 char *vers; 1024 1025 switch (cmd) { 1026 case SIOCGPPPSTATS: 1027 ppp_get_stats(ppp, &stats); 1028 if (copy_to_user(addr, &stats, sizeof(stats))) 1029 break; 1030 err = 0; 1031 break; 1032 1033 case SIOCGPPPCSTATS: 1034 memset(&cstats, 0, sizeof(cstats)); 1035 if (ppp->xc_state) 1036 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c); 1037 if (ppp->rc_state) 1038 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d); 1039 if (copy_to_user(addr, &cstats, sizeof(cstats))) 1040 break; 1041 err = 0; 1042 break; 1043 1044 case SIOCGPPPVER: 1045 vers = PPP_VERSION; 1046 if (copy_to_user(addr, vers, strlen(vers) + 1)) 1047 break; 1048 err = 0; 1049 break; 1050 1051 default: 1052 err = -EINVAL; 1053 } 1054 1055 return err; 1056 } 1057 1058 static struct rtnl_link_stats64* 1059 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64) 1060 { 1061 struct ppp *ppp = netdev_priv(dev); 1062 1063 ppp_recv_lock(ppp); 1064 stats64->rx_packets = ppp->stats64.rx_packets; 1065 stats64->rx_bytes = ppp->stats64.rx_bytes; 1066 ppp_recv_unlock(ppp); 1067 1068 ppp_xmit_lock(ppp); 1069 stats64->tx_packets = ppp->stats64.tx_packets; 1070 stats64->tx_bytes = ppp->stats64.tx_bytes; 1071 ppp_xmit_unlock(ppp); 1072 1073 stats64->rx_errors = dev->stats.rx_errors; 1074 stats64->tx_errors = dev->stats.tx_errors; 1075 stats64->rx_dropped = dev->stats.rx_dropped; 1076 stats64->tx_dropped = dev->stats.tx_dropped; 1077 stats64->rx_length_errors = dev->stats.rx_length_errors; 1078 1079 return stats64; 1080 } 1081 1082 static struct lock_class_key ppp_tx_busylock; 1083 static int ppp_dev_init(struct net_device *dev) 1084 { 1085 dev->qdisc_tx_busylock = &ppp_tx_busylock; 1086 return 0; 1087 } 1088 1089 static const struct net_device_ops ppp_netdev_ops = { 1090 .ndo_init = ppp_dev_init, 1091 .ndo_start_xmit = ppp_start_xmit, 1092 .ndo_do_ioctl = ppp_net_ioctl, 1093 .ndo_get_stats64 = ppp_get_stats64, 1094 }; 1095 1096 static void ppp_setup(struct net_device *dev) 1097 { 1098 dev->netdev_ops = &ppp_netdev_ops; 1099 dev->hard_header_len = PPP_HDRLEN; 1100 dev->mtu = PPP_MRU; 1101 dev->addr_len = 0; 1102 dev->tx_queue_len = 3; 1103 dev->type = ARPHRD_PPP; 1104 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 1105 dev->features |= NETIF_F_NETNS_LOCAL; 1106 dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; 1107 } 1108 1109 /* 1110 * Transmit-side routines. 1111 */ 1112 1113 /* 1114 * Called to do any work queued up on the transmit side 1115 * that can now be done. 1116 */ 1117 static void 1118 ppp_xmit_process(struct ppp *ppp) 1119 { 1120 struct sk_buff *skb; 1121 1122 ppp_xmit_lock(ppp); 1123 if (!ppp->closing) { 1124 ppp_push(ppp); 1125 while (!ppp->xmit_pending && 1126 (skb = skb_dequeue(&ppp->file.xq))) 1127 ppp_send_frame(ppp, skb); 1128 /* If there's no work left to do, tell the core net 1129 code that we can accept some more. */ 1130 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq)) 1131 netif_wake_queue(ppp->dev); 1132 else 1133 netif_stop_queue(ppp->dev); 1134 } 1135 ppp_xmit_unlock(ppp); 1136 } 1137 1138 static inline struct sk_buff * 1139 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) 1140 { 1141 struct sk_buff *new_skb; 1142 int len; 1143 int new_skb_size = ppp->dev->mtu + 1144 ppp->xcomp->comp_extra + ppp->dev->hard_header_len; 1145 int compressor_skb_size = ppp->dev->mtu + 1146 ppp->xcomp->comp_extra + PPP_HDRLEN; 1147 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC); 1148 if (!new_skb) { 1149 if (net_ratelimit()) 1150 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n"); 1151 return NULL; 1152 } 1153 if (ppp->dev->hard_header_len > PPP_HDRLEN) 1154 skb_reserve(new_skb, 1155 ppp->dev->hard_header_len - PPP_HDRLEN); 1156 1157 /* compressor still expects A/C bytes in hdr */ 1158 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, 1159 new_skb->data, skb->len + 2, 1160 compressor_skb_size); 1161 if (len > 0 && (ppp->flags & SC_CCP_UP)) { 1162 consume_skb(skb); 1163 skb = new_skb; 1164 skb_put(skb, len); 1165 skb_pull(skb, 2); /* pull off A/C bytes */ 1166 } else if (len == 0) { 1167 /* didn't compress, or CCP not up yet */ 1168 consume_skb(new_skb); 1169 new_skb = skb; 1170 } else { 1171 /* 1172 * (len < 0) 1173 * MPPE requires that we do not send unencrypted 1174 * frames. The compressor will return -1 if we 1175 * should drop the frame. We cannot simply test 1176 * the compress_proto because MPPE and MPPC share 1177 * the same number. 1178 */ 1179 if (net_ratelimit()) 1180 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n"); 1181 kfree_skb(skb); 1182 consume_skb(new_skb); 1183 new_skb = NULL; 1184 } 1185 return new_skb; 1186 } 1187 1188 /* 1189 * Compress and send a frame. 1190 * The caller should have locked the xmit path, 1191 * and xmit_pending should be 0. 1192 */ 1193 static void 1194 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) 1195 { 1196 int proto = PPP_PROTO(skb); 1197 struct sk_buff *new_skb; 1198 int len; 1199 unsigned char *cp; 1200 1201 if (proto < 0x8000) { 1202 #ifdef CONFIG_PPP_FILTER 1203 /* check if we should pass this packet */ 1204 /* the filter instructions are constructed assuming 1205 a four-byte PPP header on each packet */ 1206 *skb_push(skb, 2) = 1; 1207 if (ppp->pass_filter && 1208 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 1209 if (ppp->debug & 1) 1210 netdev_printk(KERN_DEBUG, ppp->dev, 1211 "PPP: outbound frame " 1212 "not passed\n"); 1213 kfree_skb(skb); 1214 return; 1215 } 1216 /* if this packet passes the active filter, record the time */ 1217 if (!(ppp->active_filter && 1218 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 1219 ppp->last_xmit = jiffies; 1220 skb_pull(skb, 2); 1221 #else 1222 /* for data packets, record the time */ 1223 ppp->last_xmit = jiffies; 1224 #endif /* CONFIG_PPP_FILTER */ 1225 } 1226 1227 ++ppp->stats64.tx_packets; 1228 ppp->stats64.tx_bytes += skb->len - 2; 1229 1230 switch (proto) { 1231 case PPP_IP: 1232 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0) 1233 break; 1234 /* try to do VJ TCP header compression */ 1235 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2, 1236 GFP_ATOMIC); 1237 if (!new_skb) { 1238 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n"); 1239 goto drop; 1240 } 1241 skb_reserve(new_skb, ppp->dev->hard_header_len - 2); 1242 cp = skb->data + 2; 1243 len = slhc_compress(ppp->vj, cp, skb->len - 2, 1244 new_skb->data + 2, &cp, 1245 !(ppp->flags & SC_NO_TCP_CCID)); 1246 if (cp == skb->data + 2) { 1247 /* didn't compress */ 1248 consume_skb(new_skb); 1249 } else { 1250 if (cp[0] & SL_TYPE_COMPRESSED_TCP) { 1251 proto = PPP_VJC_COMP; 1252 cp[0] &= ~SL_TYPE_COMPRESSED_TCP; 1253 } else { 1254 proto = PPP_VJC_UNCOMP; 1255 cp[0] = skb->data[2]; 1256 } 1257 consume_skb(skb); 1258 skb = new_skb; 1259 cp = skb_put(skb, len + 2); 1260 cp[0] = 0; 1261 cp[1] = proto; 1262 } 1263 break; 1264 1265 case PPP_CCP: 1266 /* peek at outbound CCP frames */ 1267 ppp_ccp_peek(ppp, skb, 0); 1268 break; 1269 } 1270 1271 /* try to do packet compression */ 1272 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state && 1273 proto != PPP_LCP && proto != PPP_CCP) { 1274 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) { 1275 if (net_ratelimit()) 1276 netdev_err(ppp->dev, 1277 "ppp: compression required but " 1278 "down - pkt dropped.\n"); 1279 goto drop; 1280 } 1281 skb = pad_compress_skb(ppp, skb); 1282 if (!skb) 1283 goto drop; 1284 } 1285 1286 /* 1287 * If we are waiting for traffic (demand dialling), 1288 * queue it up for pppd to receive. 1289 */ 1290 if (ppp->flags & SC_LOOP_TRAFFIC) { 1291 if (ppp->file.rq.qlen > PPP_MAX_RQLEN) 1292 goto drop; 1293 skb_queue_tail(&ppp->file.rq, skb); 1294 wake_up_interruptible(&ppp->file.rwait); 1295 return; 1296 } 1297 1298 ppp->xmit_pending = skb; 1299 ppp_push(ppp); 1300 return; 1301 1302 drop: 1303 kfree_skb(skb); 1304 ++ppp->dev->stats.tx_errors; 1305 } 1306 1307 /* 1308 * Try to send the frame in xmit_pending. 1309 * The caller should have the xmit path locked. 1310 */ 1311 static void 1312 ppp_push(struct ppp *ppp) 1313 { 1314 struct list_head *list; 1315 struct channel *pch; 1316 struct sk_buff *skb = ppp->xmit_pending; 1317 1318 if (!skb) 1319 return; 1320 1321 list = &ppp->channels; 1322 if (list_empty(list)) { 1323 /* nowhere to send the packet, just drop it */ 1324 ppp->xmit_pending = NULL; 1325 kfree_skb(skb); 1326 return; 1327 } 1328 1329 if ((ppp->flags & SC_MULTILINK) == 0) { 1330 /* not doing multilink: send it down the first channel */ 1331 list = list->next; 1332 pch = list_entry(list, struct channel, clist); 1333 1334 spin_lock_bh(&pch->downl); 1335 if (pch->chan) { 1336 if (pch->chan->ops->start_xmit(pch->chan, skb)) 1337 ppp->xmit_pending = NULL; 1338 } else { 1339 /* channel got unregistered */ 1340 kfree_skb(skb); 1341 ppp->xmit_pending = NULL; 1342 } 1343 spin_unlock_bh(&pch->downl); 1344 return; 1345 } 1346 1347 #ifdef CONFIG_PPP_MULTILINK 1348 /* Multilink: fragment the packet over as many links 1349 as can take the packet at the moment. */ 1350 if (!ppp_mp_explode(ppp, skb)) 1351 return; 1352 #endif /* CONFIG_PPP_MULTILINK */ 1353 1354 ppp->xmit_pending = NULL; 1355 kfree_skb(skb); 1356 } 1357 1358 #ifdef CONFIG_PPP_MULTILINK 1359 static bool mp_protocol_compress __read_mostly = true; 1360 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR); 1361 MODULE_PARM_DESC(mp_protocol_compress, 1362 "compress protocol id in multilink fragments"); 1363 1364 /* 1365 * Divide a packet to be transmitted into fragments and 1366 * send them out the individual links. 1367 */ 1368 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb) 1369 { 1370 int len, totlen; 1371 int i, bits, hdrlen, mtu; 1372 int flen; 1373 int navail, nfree, nzero; 1374 int nbigger; 1375 int totspeed; 1376 int totfree; 1377 unsigned char *p, *q; 1378 struct list_head *list; 1379 struct channel *pch; 1380 struct sk_buff *frag; 1381 struct ppp_channel *chan; 1382 1383 totspeed = 0; /*total bitrate of the bundle*/ 1384 nfree = 0; /* # channels which have no packet already queued */ 1385 navail = 0; /* total # of usable channels (not deregistered) */ 1386 nzero = 0; /* number of channels with zero speed associated*/ 1387 totfree = 0; /*total # of channels available and 1388 *having no queued packets before 1389 *starting the fragmentation*/ 1390 1391 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1392 i = 0; 1393 list_for_each_entry(pch, &ppp->channels, clist) { 1394 if (pch->chan) { 1395 pch->avail = 1; 1396 navail++; 1397 pch->speed = pch->chan->speed; 1398 } else { 1399 pch->avail = 0; 1400 } 1401 if (pch->avail) { 1402 if (skb_queue_empty(&pch->file.xq) || 1403 !pch->had_frag) { 1404 if (pch->speed == 0) 1405 nzero++; 1406 else 1407 totspeed += pch->speed; 1408 1409 pch->avail = 2; 1410 ++nfree; 1411 ++totfree; 1412 } 1413 if (!pch->had_frag && i < ppp->nxchan) 1414 ppp->nxchan = i; 1415 } 1416 ++i; 1417 } 1418 /* 1419 * Don't start sending this packet unless at least half of 1420 * the channels are free. This gives much better TCP 1421 * performance if we have a lot of channels. 1422 */ 1423 if (nfree == 0 || nfree < navail / 2) 1424 return 0; /* can't take now, leave it in xmit_pending */ 1425 1426 /* Do protocol field compression */ 1427 p = skb->data; 1428 len = skb->len; 1429 if (*p == 0 && mp_protocol_compress) { 1430 ++p; 1431 --len; 1432 } 1433 1434 totlen = len; 1435 nbigger = len % nfree; 1436 1437 /* skip to the channel after the one we last used 1438 and start at that one */ 1439 list = &ppp->channels; 1440 for (i = 0; i < ppp->nxchan; ++i) { 1441 list = list->next; 1442 if (list == &ppp->channels) { 1443 i = 0; 1444 break; 1445 } 1446 } 1447 1448 /* create a fragment for each channel */ 1449 bits = B; 1450 while (len > 0) { 1451 list = list->next; 1452 if (list == &ppp->channels) { 1453 i = 0; 1454 continue; 1455 } 1456 pch = list_entry(list, struct channel, clist); 1457 ++i; 1458 if (!pch->avail) 1459 continue; 1460 1461 /* 1462 * Skip this channel if it has a fragment pending already and 1463 * we haven't given a fragment to all of the free channels. 1464 */ 1465 if (pch->avail == 1) { 1466 if (nfree > 0) 1467 continue; 1468 } else { 1469 pch->avail = 1; 1470 } 1471 1472 /* check the channel's mtu and whether it is still attached. */ 1473 spin_lock_bh(&pch->downl); 1474 if (pch->chan == NULL) { 1475 /* can't use this channel, it's being deregistered */ 1476 if (pch->speed == 0) 1477 nzero--; 1478 else 1479 totspeed -= pch->speed; 1480 1481 spin_unlock_bh(&pch->downl); 1482 pch->avail = 0; 1483 totlen = len; 1484 totfree--; 1485 nfree--; 1486 if (--navail == 0) 1487 break; 1488 continue; 1489 } 1490 1491 /* 1492 *if the channel speed is not set divide 1493 *the packet evenly among the free channels; 1494 *otherwise divide it according to the speed 1495 *of the channel we are going to transmit on 1496 */ 1497 flen = len; 1498 if (nfree > 0) { 1499 if (pch->speed == 0) { 1500 flen = len/nfree; 1501 if (nbigger > 0) { 1502 flen++; 1503 nbigger--; 1504 } 1505 } else { 1506 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) / 1507 ((totspeed*totfree)/pch->speed)) - hdrlen; 1508 if (nbigger > 0) { 1509 flen += ((totfree - nzero)*pch->speed)/totspeed; 1510 nbigger -= ((totfree - nzero)*pch->speed)/ 1511 totspeed; 1512 } 1513 } 1514 nfree--; 1515 } 1516 1517 /* 1518 *check if we are on the last channel or 1519 *we exceded the length of the data to 1520 *fragment 1521 */ 1522 if ((nfree <= 0) || (flen > len)) 1523 flen = len; 1524 /* 1525 *it is not worth to tx on slow channels: 1526 *in that case from the resulting flen according to the 1527 *above formula will be equal or less than zero. 1528 *Skip the channel in this case 1529 */ 1530 if (flen <= 0) { 1531 pch->avail = 2; 1532 spin_unlock_bh(&pch->downl); 1533 continue; 1534 } 1535 1536 /* 1537 * hdrlen includes the 2-byte PPP protocol field, but the 1538 * MTU counts only the payload excluding the protocol field. 1539 * (RFC1661 Section 2) 1540 */ 1541 mtu = pch->chan->mtu - (hdrlen - 2); 1542 if (mtu < 4) 1543 mtu = 4; 1544 if (flen > mtu) 1545 flen = mtu; 1546 if (flen == len) 1547 bits |= E; 1548 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC); 1549 if (!frag) 1550 goto noskb; 1551 q = skb_put(frag, flen + hdrlen); 1552 1553 /* make the MP header */ 1554 put_unaligned_be16(PPP_MP, q); 1555 if (ppp->flags & SC_MP_XSHORTSEQ) { 1556 q[2] = bits + ((ppp->nxseq >> 8) & 0xf); 1557 q[3] = ppp->nxseq; 1558 } else { 1559 q[2] = bits; 1560 q[3] = ppp->nxseq >> 16; 1561 q[4] = ppp->nxseq >> 8; 1562 q[5] = ppp->nxseq; 1563 } 1564 1565 memcpy(q + hdrlen, p, flen); 1566 1567 /* try to send it down the channel */ 1568 chan = pch->chan; 1569 if (!skb_queue_empty(&pch->file.xq) || 1570 !chan->ops->start_xmit(chan, frag)) 1571 skb_queue_tail(&pch->file.xq, frag); 1572 pch->had_frag = 1; 1573 p += flen; 1574 len -= flen; 1575 ++ppp->nxseq; 1576 bits = 0; 1577 spin_unlock_bh(&pch->downl); 1578 } 1579 ppp->nxchan = i; 1580 1581 return 1; 1582 1583 noskb: 1584 spin_unlock_bh(&pch->downl); 1585 if (ppp->debug & 1) 1586 netdev_err(ppp->dev, "PPP: no memory (fragment)\n"); 1587 ++ppp->dev->stats.tx_errors; 1588 ++ppp->nxseq; 1589 return 1; /* abandon the frame */ 1590 } 1591 #endif /* CONFIG_PPP_MULTILINK */ 1592 1593 /* 1594 * Try to send data out on a channel. 1595 */ 1596 static void 1597 ppp_channel_push(struct channel *pch) 1598 { 1599 struct sk_buff *skb; 1600 struct ppp *ppp; 1601 1602 spin_lock_bh(&pch->downl); 1603 if (pch->chan) { 1604 while (!skb_queue_empty(&pch->file.xq)) { 1605 skb = skb_dequeue(&pch->file.xq); 1606 if (!pch->chan->ops->start_xmit(pch->chan, skb)) { 1607 /* put the packet back and try again later */ 1608 skb_queue_head(&pch->file.xq, skb); 1609 break; 1610 } 1611 } 1612 } else { 1613 /* channel got deregistered */ 1614 skb_queue_purge(&pch->file.xq); 1615 } 1616 spin_unlock_bh(&pch->downl); 1617 /* see if there is anything from the attached unit to be sent */ 1618 if (skb_queue_empty(&pch->file.xq)) { 1619 read_lock_bh(&pch->upl); 1620 ppp = pch->ppp; 1621 if (ppp) 1622 ppp_xmit_process(ppp); 1623 read_unlock_bh(&pch->upl); 1624 } 1625 } 1626 1627 /* 1628 * Receive-side routines. 1629 */ 1630 1631 struct ppp_mp_skb_parm { 1632 u32 sequence; 1633 u8 BEbits; 1634 }; 1635 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb)) 1636 1637 static inline void 1638 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1639 { 1640 ppp_recv_lock(ppp); 1641 if (!ppp->closing) 1642 ppp_receive_frame(ppp, skb, pch); 1643 else 1644 kfree_skb(skb); 1645 ppp_recv_unlock(ppp); 1646 } 1647 1648 void 1649 ppp_input(struct ppp_channel *chan, struct sk_buff *skb) 1650 { 1651 struct channel *pch = chan->ppp; 1652 int proto; 1653 1654 if (!pch) { 1655 kfree_skb(skb); 1656 return; 1657 } 1658 1659 read_lock_bh(&pch->upl); 1660 if (!pskb_may_pull(skb, 2)) { 1661 kfree_skb(skb); 1662 if (pch->ppp) { 1663 ++pch->ppp->dev->stats.rx_length_errors; 1664 ppp_receive_error(pch->ppp); 1665 } 1666 goto done; 1667 } 1668 1669 proto = PPP_PROTO(skb); 1670 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) { 1671 /* put it on the channel queue */ 1672 skb_queue_tail(&pch->file.rq, skb); 1673 /* drop old frames if queue too long */ 1674 while (pch->file.rq.qlen > PPP_MAX_RQLEN && 1675 (skb = skb_dequeue(&pch->file.rq))) 1676 kfree_skb(skb); 1677 wake_up_interruptible(&pch->file.rwait); 1678 } else { 1679 ppp_do_recv(pch->ppp, skb, pch); 1680 } 1681 1682 done: 1683 read_unlock_bh(&pch->upl); 1684 } 1685 1686 /* Put a 0-length skb in the receive queue as an error indication */ 1687 void 1688 ppp_input_error(struct ppp_channel *chan, int code) 1689 { 1690 struct channel *pch = chan->ppp; 1691 struct sk_buff *skb; 1692 1693 if (!pch) 1694 return; 1695 1696 read_lock_bh(&pch->upl); 1697 if (pch->ppp) { 1698 skb = alloc_skb(0, GFP_ATOMIC); 1699 if (skb) { 1700 skb->len = 0; /* probably unnecessary */ 1701 skb->cb[0] = code; 1702 ppp_do_recv(pch->ppp, skb, pch); 1703 } 1704 } 1705 read_unlock_bh(&pch->upl); 1706 } 1707 1708 /* 1709 * We come in here to process a received frame. 1710 * The receive side of the ppp unit is locked. 1711 */ 1712 static void 1713 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1714 { 1715 /* note: a 0-length skb is used as an error indication */ 1716 if (skb->len > 0) { 1717 #ifdef CONFIG_PPP_MULTILINK 1718 /* XXX do channel-level decompression here */ 1719 if (PPP_PROTO(skb) == PPP_MP) 1720 ppp_receive_mp_frame(ppp, skb, pch); 1721 else 1722 #endif /* CONFIG_PPP_MULTILINK */ 1723 ppp_receive_nonmp_frame(ppp, skb); 1724 } else { 1725 kfree_skb(skb); 1726 ppp_receive_error(ppp); 1727 } 1728 } 1729 1730 static void 1731 ppp_receive_error(struct ppp *ppp) 1732 { 1733 ++ppp->dev->stats.rx_errors; 1734 if (ppp->vj) 1735 slhc_toss(ppp->vj); 1736 } 1737 1738 static void 1739 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) 1740 { 1741 struct sk_buff *ns; 1742 int proto, len, npi; 1743 1744 /* 1745 * Decompress the frame, if compressed. 1746 * Note that some decompressors need to see uncompressed frames 1747 * that come in as well as compressed frames. 1748 */ 1749 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) && 1750 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0) 1751 skb = ppp_decompress_frame(ppp, skb); 1752 1753 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR) 1754 goto err; 1755 1756 proto = PPP_PROTO(skb); 1757 switch (proto) { 1758 case PPP_VJC_COMP: 1759 /* decompress VJ compressed packets */ 1760 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 1761 goto err; 1762 1763 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) { 1764 /* copy to a new sk_buff with more tailroom */ 1765 ns = dev_alloc_skb(skb->len + 128); 1766 if (!ns) { 1767 netdev_err(ppp->dev, "PPP: no memory " 1768 "(VJ decomp)\n"); 1769 goto err; 1770 } 1771 skb_reserve(ns, 2); 1772 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len); 1773 consume_skb(skb); 1774 skb = ns; 1775 } 1776 else 1777 skb->ip_summed = CHECKSUM_NONE; 1778 1779 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2); 1780 if (len <= 0) { 1781 netdev_printk(KERN_DEBUG, ppp->dev, 1782 "PPP: VJ decompression error\n"); 1783 goto err; 1784 } 1785 len += 2; 1786 if (len > skb->len) 1787 skb_put(skb, len - skb->len); 1788 else if (len < skb->len) 1789 skb_trim(skb, len); 1790 proto = PPP_IP; 1791 break; 1792 1793 case PPP_VJC_UNCOMP: 1794 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 1795 goto err; 1796 1797 /* Until we fix the decompressor need to make sure 1798 * data portion is linear. 1799 */ 1800 if (!pskb_may_pull(skb, skb->len)) 1801 goto err; 1802 1803 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) { 1804 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n"); 1805 goto err; 1806 } 1807 proto = PPP_IP; 1808 break; 1809 1810 case PPP_CCP: 1811 ppp_ccp_peek(ppp, skb, 1); 1812 break; 1813 } 1814 1815 ++ppp->stats64.rx_packets; 1816 ppp->stats64.rx_bytes += skb->len - 2; 1817 1818 npi = proto_to_npindex(proto); 1819 if (npi < 0) { 1820 /* control or unknown frame - pass it to pppd */ 1821 skb_queue_tail(&ppp->file.rq, skb); 1822 /* limit queue length by dropping old frames */ 1823 while (ppp->file.rq.qlen > PPP_MAX_RQLEN && 1824 (skb = skb_dequeue(&ppp->file.rq))) 1825 kfree_skb(skb); 1826 /* wake up any process polling or blocking on read */ 1827 wake_up_interruptible(&ppp->file.rwait); 1828 1829 } else { 1830 /* network protocol frame - give it to the kernel */ 1831 1832 #ifdef CONFIG_PPP_FILTER 1833 /* check if the packet passes the pass and active filters */ 1834 /* the filter instructions are constructed assuming 1835 a four-byte PPP header on each packet */ 1836 if (ppp->pass_filter || ppp->active_filter) { 1837 if (skb_unclone(skb, GFP_ATOMIC)) 1838 goto err; 1839 1840 *skb_push(skb, 2) = 0; 1841 if (ppp->pass_filter && 1842 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 1843 if (ppp->debug & 1) 1844 netdev_printk(KERN_DEBUG, ppp->dev, 1845 "PPP: inbound frame " 1846 "not passed\n"); 1847 kfree_skb(skb); 1848 return; 1849 } 1850 if (!(ppp->active_filter && 1851 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 1852 ppp->last_recv = jiffies; 1853 __skb_pull(skb, 2); 1854 } else 1855 #endif /* CONFIG_PPP_FILTER */ 1856 ppp->last_recv = jiffies; 1857 1858 if ((ppp->dev->flags & IFF_UP) == 0 || 1859 ppp->npmode[npi] != NPMODE_PASS) { 1860 kfree_skb(skb); 1861 } else { 1862 /* chop off protocol */ 1863 skb_pull_rcsum(skb, 2); 1864 skb->dev = ppp->dev; 1865 skb->protocol = htons(npindex_to_ethertype[npi]); 1866 skb_reset_mac_header(skb); 1867 netif_rx(skb); 1868 } 1869 } 1870 return; 1871 1872 err: 1873 kfree_skb(skb); 1874 ppp_receive_error(ppp); 1875 } 1876 1877 static struct sk_buff * 1878 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb) 1879 { 1880 int proto = PPP_PROTO(skb); 1881 struct sk_buff *ns; 1882 int len; 1883 1884 /* Until we fix all the decompressor's need to make sure 1885 * data portion is linear. 1886 */ 1887 if (!pskb_may_pull(skb, skb->len)) 1888 goto err; 1889 1890 if (proto == PPP_COMP) { 1891 int obuff_size; 1892 1893 switch(ppp->rcomp->compress_proto) { 1894 case CI_MPPE: 1895 obuff_size = ppp->mru + PPP_HDRLEN + 1; 1896 break; 1897 default: 1898 obuff_size = ppp->mru + PPP_HDRLEN; 1899 break; 1900 } 1901 1902 ns = dev_alloc_skb(obuff_size); 1903 if (!ns) { 1904 netdev_err(ppp->dev, "ppp_decompress_frame: " 1905 "no memory\n"); 1906 goto err; 1907 } 1908 /* the decompressor still expects the A/C bytes in the hdr */ 1909 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2, 1910 skb->len + 2, ns->data, obuff_size); 1911 if (len < 0) { 1912 /* Pass the compressed frame to pppd as an 1913 error indication. */ 1914 if (len == DECOMP_FATALERROR) 1915 ppp->rstate |= SC_DC_FERROR; 1916 kfree_skb(ns); 1917 goto err; 1918 } 1919 1920 consume_skb(skb); 1921 skb = ns; 1922 skb_put(skb, len); 1923 skb_pull(skb, 2); /* pull off the A/C bytes */ 1924 1925 } else { 1926 /* Uncompressed frame - pass to decompressor so it 1927 can update its dictionary if necessary. */ 1928 if (ppp->rcomp->incomp) 1929 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2, 1930 skb->len + 2); 1931 } 1932 1933 return skb; 1934 1935 err: 1936 ppp->rstate |= SC_DC_ERROR; 1937 ppp_receive_error(ppp); 1938 return skb; 1939 } 1940 1941 #ifdef CONFIG_PPP_MULTILINK 1942 /* 1943 * Receive a multilink frame. 1944 * We put it on the reconstruction queue and then pull off 1945 * as many completed frames as we can. 1946 */ 1947 static void 1948 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1949 { 1950 u32 mask, seq; 1951 struct channel *ch; 1952 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1953 1954 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0) 1955 goto err; /* no good, throw it away */ 1956 1957 /* Decode sequence number and begin/end bits */ 1958 if (ppp->flags & SC_MP_SHORTSEQ) { 1959 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3]; 1960 mask = 0xfff; 1961 } else { 1962 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5]; 1963 mask = 0xffffff; 1964 } 1965 PPP_MP_CB(skb)->BEbits = skb->data[2]; 1966 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */ 1967 1968 /* 1969 * Do protocol ID decompression on the first fragment of each packet. 1970 */ 1971 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1)) 1972 *skb_push(skb, 1) = 0; 1973 1974 /* 1975 * Expand sequence number to 32 bits, making it as close 1976 * as possible to ppp->minseq. 1977 */ 1978 seq |= ppp->minseq & ~mask; 1979 if ((int)(ppp->minseq - seq) > (int)(mask >> 1)) 1980 seq += mask + 1; 1981 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1)) 1982 seq -= mask + 1; /* should never happen */ 1983 PPP_MP_CB(skb)->sequence = seq; 1984 pch->lastseq = seq; 1985 1986 /* 1987 * If this packet comes before the next one we were expecting, 1988 * drop it. 1989 */ 1990 if (seq_before(seq, ppp->nextseq)) { 1991 kfree_skb(skb); 1992 ++ppp->dev->stats.rx_dropped; 1993 ppp_receive_error(ppp); 1994 return; 1995 } 1996 1997 /* 1998 * Reevaluate minseq, the minimum over all channels of the 1999 * last sequence number received on each channel. Because of 2000 * the increasing sequence number rule, we know that any fragment 2001 * before `minseq' which hasn't arrived is never going to arrive. 2002 * The list of channels can't change because we have the receive 2003 * side of the ppp unit locked. 2004 */ 2005 list_for_each_entry(ch, &ppp->channels, clist) { 2006 if (seq_before(ch->lastseq, seq)) 2007 seq = ch->lastseq; 2008 } 2009 if (seq_before(ppp->minseq, seq)) 2010 ppp->minseq = seq; 2011 2012 /* Put the fragment on the reconstruction queue */ 2013 ppp_mp_insert(ppp, skb); 2014 2015 /* If the queue is getting long, don't wait any longer for packets 2016 before the start of the queue. */ 2017 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) { 2018 struct sk_buff *mskb = skb_peek(&ppp->mrq); 2019 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence)) 2020 ppp->minseq = PPP_MP_CB(mskb)->sequence; 2021 } 2022 2023 /* Pull completed packets off the queue and receive them. */ 2024 while ((skb = ppp_mp_reconstruct(ppp))) { 2025 if (pskb_may_pull(skb, 2)) 2026 ppp_receive_nonmp_frame(ppp, skb); 2027 else { 2028 ++ppp->dev->stats.rx_length_errors; 2029 kfree_skb(skb); 2030 ppp_receive_error(ppp); 2031 } 2032 } 2033 2034 return; 2035 2036 err: 2037 kfree_skb(skb); 2038 ppp_receive_error(ppp); 2039 } 2040 2041 /* 2042 * Insert a fragment on the MP reconstruction queue. 2043 * The queue is ordered by increasing sequence number. 2044 */ 2045 static void 2046 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb) 2047 { 2048 struct sk_buff *p; 2049 struct sk_buff_head *list = &ppp->mrq; 2050 u32 seq = PPP_MP_CB(skb)->sequence; 2051 2052 /* N.B. we don't need to lock the list lock because we have the 2053 ppp unit receive-side lock. */ 2054 skb_queue_walk(list, p) { 2055 if (seq_before(seq, PPP_MP_CB(p)->sequence)) 2056 break; 2057 } 2058 __skb_queue_before(list, p, skb); 2059 } 2060 2061 /* 2062 * Reconstruct a packet from the MP fragment queue. 2063 * We go through increasing sequence numbers until we find a 2064 * complete packet, or we get to the sequence number for a fragment 2065 * which hasn't arrived but might still do so. 2066 */ 2067 static struct sk_buff * 2068 ppp_mp_reconstruct(struct ppp *ppp) 2069 { 2070 u32 seq = ppp->nextseq; 2071 u32 minseq = ppp->minseq; 2072 struct sk_buff_head *list = &ppp->mrq; 2073 struct sk_buff *p, *tmp; 2074 struct sk_buff *head, *tail; 2075 struct sk_buff *skb = NULL; 2076 int lost = 0, len = 0; 2077 2078 if (ppp->mrru == 0) /* do nothing until mrru is set */ 2079 return NULL; 2080 head = list->next; 2081 tail = NULL; 2082 skb_queue_walk_safe(list, p, tmp) { 2083 again: 2084 if (seq_before(PPP_MP_CB(p)->sequence, seq)) { 2085 /* this can't happen, anyway ignore the skb */ 2086 netdev_err(ppp->dev, "ppp_mp_reconstruct bad " 2087 "seq %u < %u\n", 2088 PPP_MP_CB(p)->sequence, seq); 2089 __skb_unlink(p, list); 2090 kfree_skb(p); 2091 continue; 2092 } 2093 if (PPP_MP_CB(p)->sequence != seq) { 2094 u32 oldseq; 2095 /* Fragment `seq' is missing. If it is after 2096 minseq, it might arrive later, so stop here. */ 2097 if (seq_after(seq, minseq)) 2098 break; 2099 /* Fragment `seq' is lost, keep going. */ 2100 lost = 1; 2101 oldseq = seq; 2102 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)? 2103 minseq + 1: PPP_MP_CB(p)->sequence; 2104 2105 if (ppp->debug & 1) 2106 netdev_printk(KERN_DEBUG, ppp->dev, 2107 "lost frag %u..%u\n", 2108 oldseq, seq-1); 2109 2110 goto again; 2111 } 2112 2113 /* 2114 * At this point we know that all the fragments from 2115 * ppp->nextseq to seq are either present or lost. 2116 * Also, there are no complete packets in the queue 2117 * that have no missing fragments and end before this 2118 * fragment. 2119 */ 2120 2121 /* B bit set indicates this fragment starts a packet */ 2122 if (PPP_MP_CB(p)->BEbits & B) { 2123 head = p; 2124 lost = 0; 2125 len = 0; 2126 } 2127 2128 len += p->len; 2129 2130 /* Got a complete packet yet? */ 2131 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) && 2132 (PPP_MP_CB(head)->BEbits & B)) { 2133 if (len > ppp->mrru + 2) { 2134 ++ppp->dev->stats.rx_length_errors; 2135 netdev_printk(KERN_DEBUG, ppp->dev, 2136 "PPP: reconstructed packet" 2137 " is too long (%d)\n", len); 2138 } else { 2139 tail = p; 2140 break; 2141 } 2142 ppp->nextseq = seq + 1; 2143 } 2144 2145 /* 2146 * If this is the ending fragment of a packet, 2147 * and we haven't found a complete valid packet yet, 2148 * we can discard up to and including this fragment. 2149 */ 2150 if (PPP_MP_CB(p)->BEbits & E) { 2151 struct sk_buff *tmp2; 2152 2153 skb_queue_reverse_walk_from_safe(list, p, tmp2) { 2154 if (ppp->debug & 1) 2155 netdev_printk(KERN_DEBUG, ppp->dev, 2156 "discarding frag %u\n", 2157 PPP_MP_CB(p)->sequence); 2158 __skb_unlink(p, list); 2159 kfree_skb(p); 2160 } 2161 head = skb_peek(list); 2162 if (!head) 2163 break; 2164 } 2165 ++seq; 2166 } 2167 2168 /* If we have a complete packet, copy it all into one skb. */ 2169 if (tail != NULL) { 2170 /* If we have discarded any fragments, 2171 signal a receive error. */ 2172 if (PPP_MP_CB(head)->sequence != ppp->nextseq) { 2173 skb_queue_walk_safe(list, p, tmp) { 2174 if (p == head) 2175 break; 2176 if (ppp->debug & 1) 2177 netdev_printk(KERN_DEBUG, ppp->dev, 2178 "discarding frag %u\n", 2179 PPP_MP_CB(p)->sequence); 2180 __skb_unlink(p, list); 2181 kfree_skb(p); 2182 } 2183 2184 if (ppp->debug & 1) 2185 netdev_printk(KERN_DEBUG, ppp->dev, 2186 " missed pkts %u..%u\n", 2187 ppp->nextseq, 2188 PPP_MP_CB(head)->sequence-1); 2189 ++ppp->dev->stats.rx_dropped; 2190 ppp_receive_error(ppp); 2191 } 2192 2193 skb = head; 2194 if (head != tail) { 2195 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list; 2196 p = skb_queue_next(list, head); 2197 __skb_unlink(skb, list); 2198 skb_queue_walk_from_safe(list, p, tmp) { 2199 __skb_unlink(p, list); 2200 *fragpp = p; 2201 p->next = NULL; 2202 fragpp = &p->next; 2203 2204 skb->len += p->len; 2205 skb->data_len += p->len; 2206 skb->truesize += p->truesize; 2207 2208 if (p == tail) 2209 break; 2210 } 2211 } else { 2212 __skb_unlink(skb, list); 2213 } 2214 2215 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1; 2216 } 2217 2218 return skb; 2219 } 2220 #endif /* CONFIG_PPP_MULTILINK */ 2221 2222 /* 2223 * Channel interface. 2224 */ 2225 2226 /* Create a new, unattached ppp channel. */ 2227 int ppp_register_channel(struct ppp_channel *chan) 2228 { 2229 return ppp_register_net_channel(current->nsproxy->net_ns, chan); 2230 } 2231 2232 /* Create a new, unattached ppp channel for specified net. */ 2233 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan) 2234 { 2235 struct channel *pch; 2236 struct ppp_net *pn; 2237 2238 pch = kzalloc(sizeof(struct channel), GFP_KERNEL); 2239 if (!pch) 2240 return -ENOMEM; 2241 2242 pn = ppp_pernet(net); 2243 2244 pch->ppp = NULL; 2245 pch->chan = chan; 2246 pch->chan_net = net; 2247 chan->ppp = pch; 2248 init_ppp_file(&pch->file, CHANNEL); 2249 pch->file.hdrlen = chan->hdrlen; 2250 #ifdef CONFIG_PPP_MULTILINK 2251 pch->lastseq = -1; 2252 #endif /* CONFIG_PPP_MULTILINK */ 2253 init_rwsem(&pch->chan_sem); 2254 spin_lock_init(&pch->downl); 2255 rwlock_init(&pch->upl); 2256 2257 spin_lock_bh(&pn->all_channels_lock); 2258 pch->file.index = ++pn->last_channel_index; 2259 list_add(&pch->list, &pn->new_channels); 2260 atomic_inc(&channel_count); 2261 spin_unlock_bh(&pn->all_channels_lock); 2262 2263 return 0; 2264 } 2265 2266 /* 2267 * Return the index of a channel. 2268 */ 2269 int ppp_channel_index(struct ppp_channel *chan) 2270 { 2271 struct channel *pch = chan->ppp; 2272 2273 if (pch) 2274 return pch->file.index; 2275 return -1; 2276 } 2277 2278 /* 2279 * Return the PPP unit number to which a channel is connected. 2280 */ 2281 int ppp_unit_number(struct ppp_channel *chan) 2282 { 2283 struct channel *pch = chan->ppp; 2284 int unit = -1; 2285 2286 if (pch) { 2287 read_lock_bh(&pch->upl); 2288 if (pch->ppp) 2289 unit = pch->ppp->file.index; 2290 read_unlock_bh(&pch->upl); 2291 } 2292 return unit; 2293 } 2294 2295 /* 2296 * Return the PPP device interface name of a channel. 2297 */ 2298 char *ppp_dev_name(struct ppp_channel *chan) 2299 { 2300 struct channel *pch = chan->ppp; 2301 char *name = NULL; 2302 2303 if (pch) { 2304 read_lock_bh(&pch->upl); 2305 if (pch->ppp && pch->ppp->dev) 2306 name = pch->ppp->dev->name; 2307 read_unlock_bh(&pch->upl); 2308 } 2309 return name; 2310 } 2311 2312 2313 /* 2314 * Disconnect a channel from the generic layer. 2315 * This must be called in process context. 2316 */ 2317 void 2318 ppp_unregister_channel(struct ppp_channel *chan) 2319 { 2320 struct channel *pch = chan->ppp; 2321 struct ppp_net *pn; 2322 2323 if (!pch) 2324 return; /* should never happen */ 2325 2326 chan->ppp = NULL; 2327 2328 /* 2329 * This ensures that we have returned from any calls into the 2330 * the channel's start_xmit or ioctl routine before we proceed. 2331 */ 2332 down_write(&pch->chan_sem); 2333 spin_lock_bh(&pch->downl); 2334 pch->chan = NULL; 2335 spin_unlock_bh(&pch->downl); 2336 up_write(&pch->chan_sem); 2337 ppp_disconnect_channel(pch); 2338 2339 pn = ppp_pernet(pch->chan_net); 2340 spin_lock_bh(&pn->all_channels_lock); 2341 list_del(&pch->list); 2342 spin_unlock_bh(&pn->all_channels_lock); 2343 2344 pch->file.dead = 1; 2345 wake_up_interruptible(&pch->file.rwait); 2346 if (atomic_dec_and_test(&pch->file.refcnt)) 2347 ppp_destroy_channel(pch); 2348 } 2349 2350 /* 2351 * Callback from a channel when it can accept more to transmit. 2352 * This should be called at BH/softirq level, not interrupt level. 2353 */ 2354 void 2355 ppp_output_wakeup(struct ppp_channel *chan) 2356 { 2357 struct channel *pch = chan->ppp; 2358 2359 if (!pch) 2360 return; 2361 ppp_channel_push(pch); 2362 } 2363 2364 /* 2365 * Compression control. 2366 */ 2367 2368 /* Process the PPPIOCSCOMPRESS ioctl. */ 2369 static int 2370 ppp_set_compress(struct ppp *ppp, unsigned long arg) 2371 { 2372 int err; 2373 struct compressor *cp, *ocomp; 2374 struct ppp_option_data data; 2375 void *state, *ostate; 2376 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH]; 2377 2378 err = -EFAULT; 2379 if (copy_from_user(&data, (void __user *) arg, sizeof(data)) || 2380 (data.length <= CCP_MAX_OPTION_LENGTH && 2381 copy_from_user(ccp_option, (void __user *) data.ptr, data.length))) 2382 goto out; 2383 err = -EINVAL; 2384 if (data.length > CCP_MAX_OPTION_LENGTH || 2385 ccp_option[1] < 2 || ccp_option[1] > data.length) 2386 goto out; 2387 2388 cp = try_then_request_module( 2389 find_compressor(ccp_option[0]), 2390 "ppp-compress-%d", ccp_option[0]); 2391 if (!cp) 2392 goto out; 2393 2394 err = -ENOBUFS; 2395 if (data.transmit) { 2396 state = cp->comp_alloc(ccp_option, data.length); 2397 if (state) { 2398 ppp_xmit_lock(ppp); 2399 ppp->xstate &= ~SC_COMP_RUN; 2400 ocomp = ppp->xcomp; 2401 ostate = ppp->xc_state; 2402 ppp->xcomp = cp; 2403 ppp->xc_state = state; 2404 ppp_xmit_unlock(ppp); 2405 if (ostate) { 2406 ocomp->comp_free(ostate); 2407 module_put(ocomp->owner); 2408 } 2409 err = 0; 2410 } else 2411 module_put(cp->owner); 2412 2413 } else { 2414 state = cp->decomp_alloc(ccp_option, data.length); 2415 if (state) { 2416 ppp_recv_lock(ppp); 2417 ppp->rstate &= ~SC_DECOMP_RUN; 2418 ocomp = ppp->rcomp; 2419 ostate = ppp->rc_state; 2420 ppp->rcomp = cp; 2421 ppp->rc_state = state; 2422 ppp_recv_unlock(ppp); 2423 if (ostate) { 2424 ocomp->decomp_free(ostate); 2425 module_put(ocomp->owner); 2426 } 2427 err = 0; 2428 } else 2429 module_put(cp->owner); 2430 } 2431 2432 out: 2433 return err; 2434 } 2435 2436 /* 2437 * Look at a CCP packet and update our state accordingly. 2438 * We assume the caller has the xmit or recv path locked. 2439 */ 2440 static void 2441 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound) 2442 { 2443 unsigned char *dp; 2444 int len; 2445 2446 if (!pskb_may_pull(skb, CCP_HDRLEN + 2)) 2447 return; /* no header */ 2448 dp = skb->data + 2; 2449 2450 switch (CCP_CODE(dp)) { 2451 case CCP_CONFREQ: 2452 2453 /* A ConfReq starts negotiation of compression 2454 * in one direction of transmission, 2455 * and hence brings it down...but which way? 2456 * 2457 * Remember: 2458 * A ConfReq indicates what the sender would like to receive 2459 */ 2460 if(inbound) 2461 /* He is proposing what I should send */ 2462 ppp->xstate &= ~SC_COMP_RUN; 2463 else 2464 /* I am proposing to what he should send */ 2465 ppp->rstate &= ~SC_DECOMP_RUN; 2466 2467 break; 2468 2469 case CCP_TERMREQ: 2470 case CCP_TERMACK: 2471 /* 2472 * CCP is going down, both directions of transmission 2473 */ 2474 ppp->rstate &= ~SC_DECOMP_RUN; 2475 ppp->xstate &= ~SC_COMP_RUN; 2476 break; 2477 2478 case CCP_CONFACK: 2479 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN) 2480 break; 2481 len = CCP_LENGTH(dp); 2482 if (!pskb_may_pull(skb, len + 2)) 2483 return; /* too short */ 2484 dp += CCP_HDRLEN; 2485 len -= CCP_HDRLEN; 2486 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp)) 2487 break; 2488 if (inbound) { 2489 /* we will start receiving compressed packets */ 2490 if (!ppp->rc_state) 2491 break; 2492 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len, 2493 ppp->file.index, 0, ppp->mru, ppp->debug)) { 2494 ppp->rstate |= SC_DECOMP_RUN; 2495 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR); 2496 } 2497 } else { 2498 /* we will soon start sending compressed packets */ 2499 if (!ppp->xc_state) 2500 break; 2501 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len, 2502 ppp->file.index, 0, ppp->debug)) 2503 ppp->xstate |= SC_COMP_RUN; 2504 } 2505 break; 2506 2507 case CCP_RESETACK: 2508 /* reset the [de]compressor */ 2509 if ((ppp->flags & SC_CCP_UP) == 0) 2510 break; 2511 if (inbound) { 2512 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) { 2513 ppp->rcomp->decomp_reset(ppp->rc_state); 2514 ppp->rstate &= ~SC_DC_ERROR; 2515 } 2516 } else { 2517 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN)) 2518 ppp->xcomp->comp_reset(ppp->xc_state); 2519 } 2520 break; 2521 } 2522 } 2523 2524 /* Free up compression resources. */ 2525 static void 2526 ppp_ccp_closed(struct ppp *ppp) 2527 { 2528 void *xstate, *rstate; 2529 struct compressor *xcomp, *rcomp; 2530 2531 ppp_lock(ppp); 2532 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP); 2533 ppp->xstate = 0; 2534 xcomp = ppp->xcomp; 2535 xstate = ppp->xc_state; 2536 ppp->xc_state = NULL; 2537 ppp->rstate = 0; 2538 rcomp = ppp->rcomp; 2539 rstate = ppp->rc_state; 2540 ppp->rc_state = NULL; 2541 ppp_unlock(ppp); 2542 2543 if (xstate) { 2544 xcomp->comp_free(xstate); 2545 module_put(xcomp->owner); 2546 } 2547 if (rstate) { 2548 rcomp->decomp_free(rstate); 2549 module_put(rcomp->owner); 2550 } 2551 } 2552 2553 /* List of compressors. */ 2554 static LIST_HEAD(compressor_list); 2555 static DEFINE_SPINLOCK(compressor_list_lock); 2556 2557 struct compressor_entry { 2558 struct list_head list; 2559 struct compressor *comp; 2560 }; 2561 2562 static struct compressor_entry * 2563 find_comp_entry(int proto) 2564 { 2565 struct compressor_entry *ce; 2566 2567 list_for_each_entry(ce, &compressor_list, list) { 2568 if (ce->comp->compress_proto == proto) 2569 return ce; 2570 } 2571 return NULL; 2572 } 2573 2574 /* Register a compressor */ 2575 int 2576 ppp_register_compressor(struct compressor *cp) 2577 { 2578 struct compressor_entry *ce; 2579 int ret; 2580 spin_lock(&compressor_list_lock); 2581 ret = -EEXIST; 2582 if (find_comp_entry(cp->compress_proto)) 2583 goto out; 2584 ret = -ENOMEM; 2585 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC); 2586 if (!ce) 2587 goto out; 2588 ret = 0; 2589 ce->comp = cp; 2590 list_add(&ce->list, &compressor_list); 2591 out: 2592 spin_unlock(&compressor_list_lock); 2593 return ret; 2594 } 2595 2596 /* Unregister a compressor */ 2597 void 2598 ppp_unregister_compressor(struct compressor *cp) 2599 { 2600 struct compressor_entry *ce; 2601 2602 spin_lock(&compressor_list_lock); 2603 ce = find_comp_entry(cp->compress_proto); 2604 if (ce && ce->comp == cp) { 2605 list_del(&ce->list); 2606 kfree(ce); 2607 } 2608 spin_unlock(&compressor_list_lock); 2609 } 2610 2611 /* Find a compressor. */ 2612 static struct compressor * 2613 find_compressor(int type) 2614 { 2615 struct compressor_entry *ce; 2616 struct compressor *cp = NULL; 2617 2618 spin_lock(&compressor_list_lock); 2619 ce = find_comp_entry(type); 2620 if (ce) { 2621 cp = ce->comp; 2622 if (!try_module_get(cp->owner)) 2623 cp = NULL; 2624 } 2625 spin_unlock(&compressor_list_lock); 2626 return cp; 2627 } 2628 2629 /* 2630 * Miscelleneous stuff. 2631 */ 2632 2633 static void 2634 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st) 2635 { 2636 struct slcompress *vj = ppp->vj; 2637 2638 memset(st, 0, sizeof(*st)); 2639 st->p.ppp_ipackets = ppp->stats64.rx_packets; 2640 st->p.ppp_ierrors = ppp->dev->stats.rx_errors; 2641 st->p.ppp_ibytes = ppp->stats64.rx_bytes; 2642 st->p.ppp_opackets = ppp->stats64.tx_packets; 2643 st->p.ppp_oerrors = ppp->dev->stats.tx_errors; 2644 st->p.ppp_obytes = ppp->stats64.tx_bytes; 2645 if (!vj) 2646 return; 2647 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed; 2648 st->vj.vjs_compressed = vj->sls_o_compressed; 2649 st->vj.vjs_searches = vj->sls_o_searches; 2650 st->vj.vjs_misses = vj->sls_o_misses; 2651 st->vj.vjs_errorin = vj->sls_i_error; 2652 st->vj.vjs_tossed = vj->sls_i_tossed; 2653 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed; 2654 st->vj.vjs_compressedin = vj->sls_i_compressed; 2655 } 2656 2657 /* 2658 * Stuff for handling the lists of ppp units and channels 2659 * and for initialization. 2660 */ 2661 2662 /* 2663 * Create a new ppp interface unit. Fails if it can't allocate memory 2664 * or if there is already a unit with the requested number. 2665 * unit == -1 means allocate a new number. 2666 */ 2667 static struct ppp * 2668 ppp_create_interface(struct net *net, int unit, int *retp) 2669 { 2670 struct ppp *ppp; 2671 struct ppp_net *pn; 2672 struct net_device *dev = NULL; 2673 int ret = -ENOMEM; 2674 int i; 2675 2676 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_UNKNOWN, 2677 ppp_setup); 2678 if (!dev) 2679 goto out1; 2680 2681 pn = ppp_pernet(net); 2682 2683 ppp = netdev_priv(dev); 2684 ppp->dev = dev; 2685 ppp->mru = PPP_MRU; 2686 init_ppp_file(&ppp->file, INTERFACE); 2687 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */ 2688 for (i = 0; i < NUM_NP; ++i) 2689 ppp->npmode[i] = NPMODE_PASS; 2690 INIT_LIST_HEAD(&ppp->channels); 2691 spin_lock_init(&ppp->rlock); 2692 spin_lock_init(&ppp->wlock); 2693 #ifdef CONFIG_PPP_MULTILINK 2694 ppp->minseq = -1; 2695 skb_queue_head_init(&ppp->mrq); 2696 #endif /* CONFIG_PPP_MULTILINK */ 2697 #ifdef CONFIG_PPP_FILTER 2698 ppp->pass_filter = NULL; 2699 ppp->active_filter = NULL; 2700 #endif /* CONFIG_PPP_FILTER */ 2701 2702 /* 2703 * drum roll: don't forget to set 2704 * the net device is belong to 2705 */ 2706 dev_net_set(dev, net); 2707 2708 mutex_lock(&pn->all_ppp_mutex); 2709 2710 if (unit < 0) { 2711 unit = unit_get(&pn->units_idr, ppp); 2712 if (unit < 0) { 2713 ret = unit; 2714 goto out2; 2715 } 2716 } else { 2717 ret = -EEXIST; 2718 if (unit_find(&pn->units_idr, unit)) 2719 goto out2; /* unit already exists */ 2720 /* 2721 * if caller need a specified unit number 2722 * lets try to satisfy him, otherwise -- 2723 * he should better ask us for new unit number 2724 * 2725 * NOTE: yes I know that returning EEXIST it's not 2726 * fair but at least pppd will ask us to allocate 2727 * new unit in this case so user is happy :) 2728 */ 2729 unit = unit_set(&pn->units_idr, ppp, unit); 2730 if (unit < 0) 2731 goto out2; 2732 } 2733 2734 /* Initialize the new ppp unit */ 2735 ppp->file.index = unit; 2736 sprintf(dev->name, "ppp%d", unit); 2737 2738 ret = register_netdev(dev); 2739 if (ret != 0) { 2740 unit_put(&pn->units_idr, unit); 2741 netdev_err(ppp->dev, "PPP: couldn't register device %s (%d)\n", 2742 dev->name, ret); 2743 goto out2; 2744 } 2745 2746 ppp->ppp_net = net; 2747 2748 atomic_inc(&ppp_unit_count); 2749 mutex_unlock(&pn->all_ppp_mutex); 2750 2751 *retp = 0; 2752 return ppp; 2753 2754 out2: 2755 mutex_unlock(&pn->all_ppp_mutex); 2756 free_netdev(dev); 2757 out1: 2758 *retp = ret; 2759 return NULL; 2760 } 2761 2762 /* 2763 * Initialize a ppp_file structure. 2764 */ 2765 static void 2766 init_ppp_file(struct ppp_file *pf, int kind) 2767 { 2768 pf->kind = kind; 2769 skb_queue_head_init(&pf->xq); 2770 skb_queue_head_init(&pf->rq); 2771 atomic_set(&pf->refcnt, 1); 2772 init_waitqueue_head(&pf->rwait); 2773 } 2774 2775 /* 2776 * Take down a ppp interface unit - called when the owning file 2777 * (the one that created the unit) is closed or detached. 2778 */ 2779 static void ppp_shutdown_interface(struct ppp *ppp) 2780 { 2781 struct ppp_net *pn; 2782 2783 pn = ppp_pernet(ppp->ppp_net); 2784 mutex_lock(&pn->all_ppp_mutex); 2785 2786 /* This will call dev_close() for us. */ 2787 ppp_lock(ppp); 2788 if (!ppp->closing) { 2789 ppp->closing = 1; 2790 ppp_unlock(ppp); 2791 unregister_netdev(ppp->dev); 2792 unit_put(&pn->units_idr, ppp->file.index); 2793 } else 2794 ppp_unlock(ppp); 2795 2796 ppp->file.dead = 1; 2797 ppp->owner = NULL; 2798 wake_up_interruptible(&ppp->file.rwait); 2799 2800 mutex_unlock(&pn->all_ppp_mutex); 2801 } 2802 2803 /* 2804 * Free the memory used by a ppp unit. This is only called once 2805 * there are no channels connected to the unit and no file structs 2806 * that reference the unit. 2807 */ 2808 static void ppp_destroy_interface(struct ppp *ppp) 2809 { 2810 atomic_dec(&ppp_unit_count); 2811 2812 if (!ppp->file.dead || ppp->n_channels) { 2813 /* "can't happen" */ 2814 netdev_err(ppp->dev, "ppp: destroying ppp struct %p " 2815 "but dead=%d n_channels=%d !\n", 2816 ppp, ppp->file.dead, ppp->n_channels); 2817 return; 2818 } 2819 2820 ppp_ccp_closed(ppp); 2821 if (ppp->vj) { 2822 slhc_free(ppp->vj); 2823 ppp->vj = NULL; 2824 } 2825 skb_queue_purge(&ppp->file.xq); 2826 skb_queue_purge(&ppp->file.rq); 2827 #ifdef CONFIG_PPP_MULTILINK 2828 skb_queue_purge(&ppp->mrq); 2829 #endif /* CONFIG_PPP_MULTILINK */ 2830 #ifdef CONFIG_PPP_FILTER 2831 if (ppp->pass_filter) { 2832 bpf_prog_destroy(ppp->pass_filter); 2833 ppp->pass_filter = NULL; 2834 } 2835 2836 if (ppp->active_filter) { 2837 bpf_prog_destroy(ppp->active_filter); 2838 ppp->active_filter = NULL; 2839 } 2840 #endif /* CONFIG_PPP_FILTER */ 2841 2842 kfree_skb(ppp->xmit_pending); 2843 2844 free_netdev(ppp->dev); 2845 } 2846 2847 /* 2848 * Locate an existing ppp unit. 2849 * The caller should have locked the all_ppp_mutex. 2850 */ 2851 static struct ppp * 2852 ppp_find_unit(struct ppp_net *pn, int unit) 2853 { 2854 return unit_find(&pn->units_idr, unit); 2855 } 2856 2857 /* 2858 * Locate an existing ppp channel. 2859 * The caller should have locked the all_channels_lock. 2860 * First we look in the new_channels list, then in the 2861 * all_channels list. If found in the new_channels list, 2862 * we move it to the all_channels list. This is for speed 2863 * when we have a lot of channels in use. 2864 */ 2865 static struct channel * 2866 ppp_find_channel(struct ppp_net *pn, int unit) 2867 { 2868 struct channel *pch; 2869 2870 list_for_each_entry(pch, &pn->new_channels, list) { 2871 if (pch->file.index == unit) { 2872 list_move(&pch->list, &pn->all_channels); 2873 return pch; 2874 } 2875 } 2876 2877 list_for_each_entry(pch, &pn->all_channels, list) { 2878 if (pch->file.index == unit) 2879 return pch; 2880 } 2881 2882 return NULL; 2883 } 2884 2885 /* 2886 * Connect a PPP channel to a PPP interface unit. 2887 */ 2888 static int 2889 ppp_connect_channel(struct channel *pch, int unit) 2890 { 2891 struct ppp *ppp; 2892 struct ppp_net *pn; 2893 int ret = -ENXIO; 2894 int hdrlen; 2895 2896 pn = ppp_pernet(pch->chan_net); 2897 2898 mutex_lock(&pn->all_ppp_mutex); 2899 ppp = ppp_find_unit(pn, unit); 2900 if (!ppp) 2901 goto out; 2902 write_lock_bh(&pch->upl); 2903 ret = -EINVAL; 2904 if (pch->ppp) 2905 goto outl; 2906 2907 ppp_lock(ppp); 2908 if (pch->file.hdrlen > ppp->file.hdrlen) 2909 ppp->file.hdrlen = pch->file.hdrlen; 2910 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */ 2911 if (hdrlen > ppp->dev->hard_header_len) 2912 ppp->dev->hard_header_len = hdrlen; 2913 list_add_tail(&pch->clist, &ppp->channels); 2914 ++ppp->n_channels; 2915 pch->ppp = ppp; 2916 atomic_inc(&ppp->file.refcnt); 2917 ppp_unlock(ppp); 2918 ret = 0; 2919 2920 outl: 2921 write_unlock_bh(&pch->upl); 2922 out: 2923 mutex_unlock(&pn->all_ppp_mutex); 2924 return ret; 2925 } 2926 2927 /* 2928 * Disconnect a channel from its ppp unit. 2929 */ 2930 static int 2931 ppp_disconnect_channel(struct channel *pch) 2932 { 2933 struct ppp *ppp; 2934 int err = -EINVAL; 2935 2936 write_lock_bh(&pch->upl); 2937 ppp = pch->ppp; 2938 pch->ppp = NULL; 2939 write_unlock_bh(&pch->upl); 2940 if (ppp) { 2941 /* remove it from the ppp unit's list */ 2942 ppp_lock(ppp); 2943 list_del(&pch->clist); 2944 if (--ppp->n_channels == 0) 2945 wake_up_interruptible(&ppp->file.rwait); 2946 ppp_unlock(ppp); 2947 if (atomic_dec_and_test(&ppp->file.refcnt)) 2948 ppp_destroy_interface(ppp); 2949 err = 0; 2950 } 2951 return err; 2952 } 2953 2954 /* 2955 * Free up the resources used by a ppp channel. 2956 */ 2957 static void ppp_destroy_channel(struct channel *pch) 2958 { 2959 atomic_dec(&channel_count); 2960 2961 if (!pch->file.dead) { 2962 /* "can't happen" */ 2963 pr_err("ppp: destroying undead channel %p !\n", pch); 2964 return; 2965 } 2966 skb_queue_purge(&pch->file.xq); 2967 skb_queue_purge(&pch->file.rq); 2968 kfree(pch); 2969 } 2970 2971 static void __exit ppp_cleanup(void) 2972 { 2973 /* should never happen */ 2974 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count)) 2975 pr_err("PPP: removing module but units remain!\n"); 2976 unregister_chrdev(PPP_MAJOR, "ppp"); 2977 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0)); 2978 class_destroy(ppp_class); 2979 unregister_pernet_device(&ppp_net_ops); 2980 } 2981 2982 /* 2983 * Units handling. Caller must protect concurrent access 2984 * by holding all_ppp_mutex 2985 */ 2986 2987 /* associate pointer with specified number */ 2988 static int unit_set(struct idr *p, void *ptr, int n) 2989 { 2990 int unit; 2991 2992 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL); 2993 if (unit == -ENOSPC) 2994 unit = -EINVAL; 2995 return unit; 2996 } 2997 2998 /* get new free unit number and associate pointer with it */ 2999 static int unit_get(struct idr *p, void *ptr) 3000 { 3001 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL); 3002 } 3003 3004 /* put unit number back to a pool */ 3005 static void unit_put(struct idr *p, int n) 3006 { 3007 idr_remove(p, n); 3008 } 3009 3010 /* get pointer associated with the number */ 3011 static void *unit_find(struct idr *p, int n) 3012 { 3013 return idr_find(p, n); 3014 } 3015 3016 /* Module/initialization stuff */ 3017 3018 module_init(ppp_init); 3019 module_exit(ppp_cleanup); 3020 3021 EXPORT_SYMBOL(ppp_register_net_channel); 3022 EXPORT_SYMBOL(ppp_register_channel); 3023 EXPORT_SYMBOL(ppp_unregister_channel); 3024 EXPORT_SYMBOL(ppp_channel_index); 3025 EXPORT_SYMBOL(ppp_unit_number); 3026 EXPORT_SYMBOL(ppp_dev_name); 3027 EXPORT_SYMBOL(ppp_input); 3028 EXPORT_SYMBOL(ppp_input_error); 3029 EXPORT_SYMBOL(ppp_output_wakeup); 3030 EXPORT_SYMBOL(ppp_register_compressor); 3031 EXPORT_SYMBOL(ppp_unregister_compressor); 3032 MODULE_LICENSE("GPL"); 3033 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0); 3034 MODULE_ALIAS("devname:ppp"); 3035