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 struct iov_iter to; 421 422 ret = count; 423 424 if (!pf) 425 return -ENXIO; 426 add_wait_queue(&pf->rwait, &wait); 427 for (;;) { 428 set_current_state(TASK_INTERRUPTIBLE); 429 skb = skb_dequeue(&pf->rq); 430 if (skb) 431 break; 432 ret = 0; 433 if (pf->dead) 434 break; 435 if (pf->kind == INTERFACE) { 436 /* 437 * Return 0 (EOF) on an interface that has no 438 * channels connected, unless it is looping 439 * network traffic (demand mode). 440 */ 441 struct ppp *ppp = PF_TO_PPP(pf); 442 if (ppp->n_channels == 0 && 443 (ppp->flags & SC_LOOP_TRAFFIC) == 0) 444 break; 445 } 446 ret = -EAGAIN; 447 if (file->f_flags & O_NONBLOCK) 448 break; 449 ret = -ERESTARTSYS; 450 if (signal_pending(current)) 451 break; 452 schedule(); 453 } 454 set_current_state(TASK_RUNNING); 455 remove_wait_queue(&pf->rwait, &wait); 456 457 if (!skb) 458 goto out; 459 460 ret = -EOVERFLOW; 461 if (skb->len > count) 462 goto outf; 463 ret = -EFAULT; 464 iov.iov_base = buf; 465 iov.iov_len = count; 466 iov_iter_init(&to, READ, &iov, 1, count); 467 if (skb_copy_datagram_iter(skb, 0, &to, skb->len)) 468 goto outf; 469 ret = skb->len; 470 471 outf: 472 kfree_skb(skb); 473 out: 474 return ret; 475 } 476 477 static ssize_t ppp_write(struct file *file, const char __user *buf, 478 size_t count, loff_t *ppos) 479 { 480 struct ppp_file *pf = file->private_data; 481 struct sk_buff *skb; 482 ssize_t ret; 483 484 if (!pf) 485 return -ENXIO; 486 ret = -ENOMEM; 487 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL); 488 if (!skb) 489 goto out; 490 skb_reserve(skb, pf->hdrlen); 491 ret = -EFAULT; 492 if (copy_from_user(skb_put(skb, count), buf, count)) { 493 kfree_skb(skb); 494 goto out; 495 } 496 497 skb_queue_tail(&pf->xq, skb); 498 499 switch (pf->kind) { 500 case INTERFACE: 501 ppp_xmit_process(PF_TO_PPP(pf)); 502 break; 503 case CHANNEL: 504 ppp_channel_push(PF_TO_CHANNEL(pf)); 505 break; 506 } 507 508 ret = count; 509 510 out: 511 return ret; 512 } 513 514 /* No kernel lock - fine */ 515 static unsigned int ppp_poll(struct file *file, poll_table *wait) 516 { 517 struct ppp_file *pf = file->private_data; 518 unsigned int mask; 519 520 if (!pf) 521 return 0; 522 poll_wait(file, &pf->rwait, wait); 523 mask = POLLOUT | POLLWRNORM; 524 if (skb_peek(&pf->rq)) 525 mask |= POLLIN | POLLRDNORM; 526 if (pf->dead) 527 mask |= POLLHUP; 528 else if (pf->kind == INTERFACE) { 529 /* see comment in ppp_read */ 530 struct ppp *ppp = PF_TO_PPP(pf); 531 if (ppp->n_channels == 0 && 532 (ppp->flags & SC_LOOP_TRAFFIC) == 0) 533 mask |= POLLIN | POLLRDNORM; 534 } 535 536 return mask; 537 } 538 539 #ifdef CONFIG_PPP_FILTER 540 static int get_filter(void __user *arg, struct sock_filter **p) 541 { 542 struct sock_fprog uprog; 543 struct sock_filter *code = NULL; 544 int len; 545 546 if (copy_from_user(&uprog, arg, sizeof(uprog))) 547 return -EFAULT; 548 549 if (!uprog.len) { 550 *p = NULL; 551 return 0; 552 } 553 554 len = uprog.len * sizeof(struct sock_filter); 555 code = memdup_user(uprog.filter, len); 556 if (IS_ERR(code)) 557 return PTR_ERR(code); 558 559 *p = code; 560 return uprog.len; 561 } 562 #endif /* CONFIG_PPP_FILTER */ 563 564 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 565 { 566 struct ppp_file *pf = file->private_data; 567 struct ppp *ppp; 568 int err = -EFAULT, val, val2, i; 569 struct ppp_idle idle; 570 struct npioctl npi; 571 int unit, cflags; 572 struct slcompress *vj; 573 void __user *argp = (void __user *)arg; 574 int __user *p = argp; 575 576 if (!pf) 577 return ppp_unattached_ioctl(current->nsproxy->net_ns, 578 pf, file, cmd, arg); 579 580 if (cmd == PPPIOCDETACH) { 581 /* 582 * We have to be careful here... if the file descriptor 583 * has been dup'd, we could have another process in the 584 * middle of a poll using the same file *, so we had 585 * better not free the interface data structures - 586 * instead we fail the ioctl. Even in this case, we 587 * shut down the interface if we are the owner of it. 588 * Actually, we should get rid of PPPIOCDETACH, userland 589 * (i.e. pppd) could achieve the same effect by closing 590 * this fd and reopening /dev/ppp. 591 */ 592 err = -EINVAL; 593 mutex_lock(&ppp_mutex); 594 if (pf->kind == INTERFACE) { 595 ppp = PF_TO_PPP(pf); 596 if (file == ppp->owner) 597 ppp_shutdown_interface(ppp); 598 } 599 if (atomic_long_read(&file->f_count) < 2) { 600 ppp_release(NULL, file); 601 err = 0; 602 } else 603 pr_warn("PPPIOCDETACH file->f_count=%ld\n", 604 atomic_long_read(&file->f_count)); 605 mutex_unlock(&ppp_mutex); 606 return err; 607 } 608 609 if (pf->kind == CHANNEL) { 610 struct channel *pch; 611 struct ppp_channel *chan; 612 613 mutex_lock(&ppp_mutex); 614 pch = PF_TO_CHANNEL(pf); 615 616 switch (cmd) { 617 case PPPIOCCONNECT: 618 if (get_user(unit, p)) 619 break; 620 err = ppp_connect_channel(pch, unit); 621 break; 622 623 case PPPIOCDISCONN: 624 err = ppp_disconnect_channel(pch); 625 break; 626 627 default: 628 down_read(&pch->chan_sem); 629 chan = pch->chan; 630 err = -ENOTTY; 631 if (chan && chan->ops->ioctl) 632 err = chan->ops->ioctl(chan, cmd, arg); 633 up_read(&pch->chan_sem); 634 } 635 mutex_unlock(&ppp_mutex); 636 return err; 637 } 638 639 if (pf->kind != INTERFACE) { 640 /* can't happen */ 641 pr_err("PPP: not interface or channel??\n"); 642 return -EINVAL; 643 } 644 645 mutex_lock(&ppp_mutex); 646 ppp = PF_TO_PPP(pf); 647 switch (cmd) { 648 case PPPIOCSMRU: 649 if (get_user(val, p)) 650 break; 651 ppp->mru = val; 652 err = 0; 653 break; 654 655 case PPPIOCSFLAGS: 656 if (get_user(val, p)) 657 break; 658 ppp_lock(ppp); 659 cflags = ppp->flags & ~val; 660 #ifdef CONFIG_PPP_MULTILINK 661 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK)) 662 ppp->nextseq = 0; 663 #endif 664 ppp->flags = val & SC_FLAG_BITS; 665 ppp_unlock(ppp); 666 if (cflags & SC_CCP_OPEN) 667 ppp_ccp_closed(ppp); 668 err = 0; 669 break; 670 671 case PPPIOCGFLAGS: 672 val = ppp->flags | ppp->xstate | ppp->rstate; 673 if (put_user(val, p)) 674 break; 675 err = 0; 676 break; 677 678 case PPPIOCSCOMPRESS: 679 err = ppp_set_compress(ppp, arg); 680 break; 681 682 case PPPIOCGUNIT: 683 if (put_user(ppp->file.index, p)) 684 break; 685 err = 0; 686 break; 687 688 case PPPIOCSDEBUG: 689 if (get_user(val, p)) 690 break; 691 ppp->debug = val; 692 err = 0; 693 break; 694 695 case PPPIOCGDEBUG: 696 if (put_user(ppp->debug, p)) 697 break; 698 err = 0; 699 break; 700 701 case PPPIOCGIDLE: 702 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ; 703 idle.recv_idle = (jiffies - ppp->last_recv) / HZ; 704 if (copy_to_user(argp, &idle, sizeof(idle))) 705 break; 706 err = 0; 707 break; 708 709 case PPPIOCSMAXCID: 710 if (get_user(val, p)) 711 break; 712 val2 = 15; 713 if ((val >> 16) != 0) { 714 val2 = val >> 16; 715 val &= 0xffff; 716 } 717 vj = slhc_init(val2+1, val+1); 718 if (!vj) { 719 netdev_err(ppp->dev, 720 "PPP: no memory (VJ compressor)\n"); 721 err = -ENOMEM; 722 break; 723 } 724 ppp_lock(ppp); 725 if (ppp->vj) 726 slhc_free(ppp->vj); 727 ppp->vj = vj; 728 ppp_unlock(ppp); 729 err = 0; 730 break; 731 732 case PPPIOCGNPMODE: 733 case PPPIOCSNPMODE: 734 if (copy_from_user(&npi, argp, sizeof(npi))) 735 break; 736 err = proto_to_npindex(npi.protocol); 737 if (err < 0) 738 break; 739 i = err; 740 if (cmd == PPPIOCGNPMODE) { 741 err = -EFAULT; 742 npi.mode = ppp->npmode[i]; 743 if (copy_to_user(argp, &npi, sizeof(npi))) 744 break; 745 } else { 746 ppp->npmode[i] = npi.mode; 747 /* we may be able to transmit more packets now (??) */ 748 netif_wake_queue(ppp->dev); 749 } 750 err = 0; 751 break; 752 753 #ifdef CONFIG_PPP_FILTER 754 case PPPIOCSPASS: 755 { 756 struct sock_filter *code; 757 758 err = get_filter(argp, &code); 759 if (err >= 0) { 760 struct bpf_prog *pass_filter = NULL; 761 struct sock_fprog_kern fprog = { 762 .len = err, 763 .filter = code, 764 }; 765 766 err = 0; 767 if (fprog.filter) 768 err = bpf_prog_create(&pass_filter, &fprog); 769 if (!err) { 770 ppp_lock(ppp); 771 if (ppp->pass_filter) 772 bpf_prog_destroy(ppp->pass_filter); 773 ppp->pass_filter = pass_filter; 774 ppp_unlock(ppp); 775 } 776 kfree(code); 777 } 778 break; 779 } 780 case PPPIOCSACTIVE: 781 { 782 struct sock_filter *code; 783 784 err = get_filter(argp, &code); 785 if (err >= 0) { 786 struct bpf_prog *active_filter = NULL; 787 struct sock_fprog_kern fprog = { 788 .len = err, 789 .filter = code, 790 }; 791 792 err = 0; 793 if (fprog.filter) 794 err = bpf_prog_create(&active_filter, &fprog); 795 if (!err) { 796 ppp_lock(ppp); 797 if (ppp->active_filter) 798 bpf_prog_destroy(ppp->active_filter); 799 ppp->active_filter = active_filter; 800 ppp_unlock(ppp); 801 } 802 kfree(code); 803 } 804 break; 805 } 806 #endif /* CONFIG_PPP_FILTER */ 807 808 #ifdef CONFIG_PPP_MULTILINK 809 case PPPIOCSMRRU: 810 if (get_user(val, p)) 811 break; 812 ppp_recv_lock(ppp); 813 ppp->mrru = val; 814 ppp_recv_unlock(ppp); 815 err = 0; 816 break; 817 #endif /* CONFIG_PPP_MULTILINK */ 818 819 default: 820 err = -ENOTTY; 821 } 822 mutex_unlock(&ppp_mutex); 823 return err; 824 } 825 826 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 827 struct file *file, unsigned int cmd, unsigned long arg) 828 { 829 int unit, err = -EFAULT; 830 struct ppp *ppp; 831 struct channel *chan; 832 struct ppp_net *pn; 833 int __user *p = (int __user *)arg; 834 835 mutex_lock(&ppp_mutex); 836 switch (cmd) { 837 case PPPIOCNEWUNIT: 838 /* Create a new ppp unit */ 839 if (get_user(unit, p)) 840 break; 841 ppp = ppp_create_interface(net, unit, &err); 842 if (!ppp) 843 break; 844 file->private_data = &ppp->file; 845 ppp->owner = file; 846 err = -EFAULT; 847 if (put_user(ppp->file.index, p)) 848 break; 849 err = 0; 850 break; 851 852 case PPPIOCATTACH: 853 /* Attach to an existing ppp unit */ 854 if (get_user(unit, p)) 855 break; 856 err = -ENXIO; 857 pn = ppp_pernet(net); 858 mutex_lock(&pn->all_ppp_mutex); 859 ppp = ppp_find_unit(pn, unit); 860 if (ppp) { 861 atomic_inc(&ppp->file.refcnt); 862 file->private_data = &ppp->file; 863 err = 0; 864 } 865 mutex_unlock(&pn->all_ppp_mutex); 866 break; 867 868 case PPPIOCATTCHAN: 869 if (get_user(unit, p)) 870 break; 871 err = -ENXIO; 872 pn = ppp_pernet(net); 873 spin_lock_bh(&pn->all_channels_lock); 874 chan = ppp_find_channel(pn, unit); 875 if (chan) { 876 atomic_inc(&chan->file.refcnt); 877 file->private_data = &chan->file; 878 err = 0; 879 } 880 spin_unlock_bh(&pn->all_channels_lock); 881 break; 882 883 default: 884 err = -ENOTTY; 885 } 886 mutex_unlock(&ppp_mutex); 887 return err; 888 } 889 890 static const struct file_operations ppp_device_fops = { 891 .owner = THIS_MODULE, 892 .read = ppp_read, 893 .write = ppp_write, 894 .poll = ppp_poll, 895 .unlocked_ioctl = ppp_ioctl, 896 .open = ppp_open, 897 .release = ppp_release, 898 .llseek = noop_llseek, 899 }; 900 901 static __net_init int ppp_init_net(struct net *net) 902 { 903 struct ppp_net *pn = net_generic(net, ppp_net_id); 904 905 idr_init(&pn->units_idr); 906 mutex_init(&pn->all_ppp_mutex); 907 908 INIT_LIST_HEAD(&pn->all_channels); 909 INIT_LIST_HEAD(&pn->new_channels); 910 911 spin_lock_init(&pn->all_channels_lock); 912 913 return 0; 914 } 915 916 static __net_exit void ppp_exit_net(struct net *net) 917 { 918 struct ppp_net *pn = net_generic(net, ppp_net_id); 919 920 idr_destroy(&pn->units_idr); 921 } 922 923 static struct pernet_operations ppp_net_ops = { 924 .init = ppp_init_net, 925 .exit = ppp_exit_net, 926 .id = &ppp_net_id, 927 .size = sizeof(struct ppp_net), 928 }; 929 930 #define PPP_MAJOR 108 931 932 /* Called at boot time if ppp is compiled into the kernel, 933 or at module load time (from init_module) if compiled as a module. */ 934 static int __init ppp_init(void) 935 { 936 int err; 937 938 pr_info("PPP generic driver version " PPP_VERSION "\n"); 939 940 err = register_pernet_device(&ppp_net_ops); 941 if (err) { 942 pr_err("failed to register PPP pernet device (%d)\n", err); 943 goto out; 944 } 945 946 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops); 947 if (err) { 948 pr_err("failed to register PPP device (%d)\n", err); 949 goto out_net; 950 } 951 952 ppp_class = class_create(THIS_MODULE, "ppp"); 953 if (IS_ERR(ppp_class)) { 954 err = PTR_ERR(ppp_class); 955 goto out_chrdev; 956 } 957 958 /* not a big deal if we fail here :-) */ 959 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp"); 960 961 return 0; 962 963 out_chrdev: 964 unregister_chrdev(PPP_MAJOR, "ppp"); 965 out_net: 966 unregister_pernet_device(&ppp_net_ops); 967 out: 968 return err; 969 } 970 971 /* 972 * Network interface unit routines. 973 */ 974 static netdev_tx_t 975 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev) 976 { 977 struct ppp *ppp = netdev_priv(dev); 978 int npi, proto; 979 unsigned char *pp; 980 981 npi = ethertype_to_npindex(ntohs(skb->protocol)); 982 if (npi < 0) 983 goto outf; 984 985 /* Drop, accept or reject the packet */ 986 switch (ppp->npmode[npi]) { 987 case NPMODE_PASS: 988 break; 989 case NPMODE_QUEUE: 990 /* it would be nice to have a way to tell the network 991 system to queue this one up for later. */ 992 goto outf; 993 case NPMODE_DROP: 994 case NPMODE_ERROR: 995 goto outf; 996 } 997 998 /* Put the 2-byte PPP protocol number on the front, 999 making sure there is room for the address and control fields. */ 1000 if (skb_cow_head(skb, PPP_HDRLEN)) 1001 goto outf; 1002 1003 pp = skb_push(skb, 2); 1004 proto = npindex_to_proto[npi]; 1005 put_unaligned_be16(proto, pp); 1006 1007 skb_queue_tail(&ppp->file.xq, skb); 1008 ppp_xmit_process(ppp); 1009 return NETDEV_TX_OK; 1010 1011 outf: 1012 kfree_skb(skb); 1013 ++dev->stats.tx_dropped; 1014 return NETDEV_TX_OK; 1015 } 1016 1017 static int 1018 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 1019 { 1020 struct ppp *ppp = netdev_priv(dev); 1021 int err = -EFAULT; 1022 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data; 1023 struct ppp_stats stats; 1024 struct ppp_comp_stats cstats; 1025 char *vers; 1026 1027 switch (cmd) { 1028 case SIOCGPPPSTATS: 1029 ppp_get_stats(ppp, &stats); 1030 if (copy_to_user(addr, &stats, sizeof(stats))) 1031 break; 1032 err = 0; 1033 break; 1034 1035 case SIOCGPPPCSTATS: 1036 memset(&cstats, 0, sizeof(cstats)); 1037 if (ppp->xc_state) 1038 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c); 1039 if (ppp->rc_state) 1040 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d); 1041 if (copy_to_user(addr, &cstats, sizeof(cstats))) 1042 break; 1043 err = 0; 1044 break; 1045 1046 case SIOCGPPPVER: 1047 vers = PPP_VERSION; 1048 if (copy_to_user(addr, vers, strlen(vers) + 1)) 1049 break; 1050 err = 0; 1051 break; 1052 1053 default: 1054 err = -EINVAL; 1055 } 1056 1057 return err; 1058 } 1059 1060 static struct rtnl_link_stats64* 1061 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64) 1062 { 1063 struct ppp *ppp = netdev_priv(dev); 1064 1065 ppp_recv_lock(ppp); 1066 stats64->rx_packets = ppp->stats64.rx_packets; 1067 stats64->rx_bytes = ppp->stats64.rx_bytes; 1068 ppp_recv_unlock(ppp); 1069 1070 ppp_xmit_lock(ppp); 1071 stats64->tx_packets = ppp->stats64.tx_packets; 1072 stats64->tx_bytes = ppp->stats64.tx_bytes; 1073 ppp_xmit_unlock(ppp); 1074 1075 stats64->rx_errors = dev->stats.rx_errors; 1076 stats64->tx_errors = dev->stats.tx_errors; 1077 stats64->rx_dropped = dev->stats.rx_dropped; 1078 stats64->tx_dropped = dev->stats.tx_dropped; 1079 stats64->rx_length_errors = dev->stats.rx_length_errors; 1080 1081 return stats64; 1082 } 1083 1084 static struct lock_class_key ppp_tx_busylock; 1085 static int ppp_dev_init(struct net_device *dev) 1086 { 1087 dev->qdisc_tx_busylock = &ppp_tx_busylock; 1088 return 0; 1089 } 1090 1091 static const struct net_device_ops ppp_netdev_ops = { 1092 .ndo_init = ppp_dev_init, 1093 .ndo_start_xmit = ppp_start_xmit, 1094 .ndo_do_ioctl = ppp_net_ioctl, 1095 .ndo_get_stats64 = ppp_get_stats64, 1096 }; 1097 1098 static void ppp_setup(struct net_device *dev) 1099 { 1100 dev->netdev_ops = &ppp_netdev_ops; 1101 dev->hard_header_len = PPP_HDRLEN; 1102 dev->mtu = PPP_MRU; 1103 dev->addr_len = 0; 1104 dev->tx_queue_len = 3; 1105 dev->type = ARPHRD_PPP; 1106 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 1107 dev->features |= NETIF_F_NETNS_LOCAL; 1108 netif_keep_dst(dev); 1109 } 1110 1111 /* 1112 * Transmit-side routines. 1113 */ 1114 1115 /* 1116 * Called to do any work queued up on the transmit side 1117 * that can now be done. 1118 */ 1119 static void 1120 ppp_xmit_process(struct ppp *ppp) 1121 { 1122 struct sk_buff *skb; 1123 1124 ppp_xmit_lock(ppp); 1125 if (!ppp->closing) { 1126 ppp_push(ppp); 1127 while (!ppp->xmit_pending && 1128 (skb = skb_dequeue(&ppp->file.xq))) 1129 ppp_send_frame(ppp, skb); 1130 /* If there's no work left to do, tell the core net 1131 code that we can accept some more. */ 1132 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq)) 1133 netif_wake_queue(ppp->dev); 1134 else 1135 netif_stop_queue(ppp->dev); 1136 } 1137 ppp_xmit_unlock(ppp); 1138 } 1139 1140 static inline struct sk_buff * 1141 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) 1142 { 1143 struct sk_buff *new_skb; 1144 int len; 1145 int new_skb_size = ppp->dev->mtu + 1146 ppp->xcomp->comp_extra + ppp->dev->hard_header_len; 1147 int compressor_skb_size = ppp->dev->mtu + 1148 ppp->xcomp->comp_extra + PPP_HDRLEN; 1149 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC); 1150 if (!new_skb) { 1151 if (net_ratelimit()) 1152 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n"); 1153 return NULL; 1154 } 1155 if (ppp->dev->hard_header_len > PPP_HDRLEN) 1156 skb_reserve(new_skb, 1157 ppp->dev->hard_header_len - PPP_HDRLEN); 1158 1159 /* compressor still expects A/C bytes in hdr */ 1160 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, 1161 new_skb->data, skb->len + 2, 1162 compressor_skb_size); 1163 if (len > 0 && (ppp->flags & SC_CCP_UP)) { 1164 consume_skb(skb); 1165 skb = new_skb; 1166 skb_put(skb, len); 1167 skb_pull(skb, 2); /* pull off A/C bytes */ 1168 } else if (len == 0) { 1169 /* didn't compress, or CCP not up yet */ 1170 consume_skb(new_skb); 1171 new_skb = skb; 1172 } else { 1173 /* 1174 * (len < 0) 1175 * MPPE requires that we do not send unencrypted 1176 * frames. The compressor will return -1 if we 1177 * should drop the frame. We cannot simply test 1178 * the compress_proto because MPPE and MPPC share 1179 * the same number. 1180 */ 1181 if (net_ratelimit()) 1182 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n"); 1183 kfree_skb(skb); 1184 consume_skb(new_skb); 1185 new_skb = NULL; 1186 } 1187 return new_skb; 1188 } 1189 1190 /* 1191 * Compress and send a frame. 1192 * The caller should have locked the xmit path, 1193 * and xmit_pending should be 0. 1194 */ 1195 static void 1196 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) 1197 { 1198 int proto = PPP_PROTO(skb); 1199 struct sk_buff *new_skb; 1200 int len; 1201 unsigned char *cp; 1202 1203 if (proto < 0x8000) { 1204 #ifdef CONFIG_PPP_FILTER 1205 /* check if we should pass this packet */ 1206 /* the filter instructions are constructed assuming 1207 a four-byte PPP header on each packet */ 1208 *skb_push(skb, 2) = 1; 1209 if (ppp->pass_filter && 1210 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 1211 if (ppp->debug & 1) 1212 netdev_printk(KERN_DEBUG, ppp->dev, 1213 "PPP: outbound frame " 1214 "not passed\n"); 1215 kfree_skb(skb); 1216 return; 1217 } 1218 /* if this packet passes the active filter, record the time */ 1219 if (!(ppp->active_filter && 1220 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 1221 ppp->last_xmit = jiffies; 1222 skb_pull(skb, 2); 1223 #else 1224 /* for data packets, record the time */ 1225 ppp->last_xmit = jiffies; 1226 #endif /* CONFIG_PPP_FILTER */ 1227 } 1228 1229 ++ppp->stats64.tx_packets; 1230 ppp->stats64.tx_bytes += skb->len - 2; 1231 1232 switch (proto) { 1233 case PPP_IP: 1234 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0) 1235 break; 1236 /* try to do VJ TCP header compression */ 1237 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2, 1238 GFP_ATOMIC); 1239 if (!new_skb) { 1240 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n"); 1241 goto drop; 1242 } 1243 skb_reserve(new_skb, ppp->dev->hard_header_len - 2); 1244 cp = skb->data + 2; 1245 len = slhc_compress(ppp->vj, cp, skb->len - 2, 1246 new_skb->data + 2, &cp, 1247 !(ppp->flags & SC_NO_TCP_CCID)); 1248 if (cp == skb->data + 2) { 1249 /* didn't compress */ 1250 consume_skb(new_skb); 1251 } else { 1252 if (cp[0] & SL_TYPE_COMPRESSED_TCP) { 1253 proto = PPP_VJC_COMP; 1254 cp[0] &= ~SL_TYPE_COMPRESSED_TCP; 1255 } else { 1256 proto = PPP_VJC_UNCOMP; 1257 cp[0] = skb->data[2]; 1258 } 1259 consume_skb(skb); 1260 skb = new_skb; 1261 cp = skb_put(skb, len + 2); 1262 cp[0] = 0; 1263 cp[1] = proto; 1264 } 1265 break; 1266 1267 case PPP_CCP: 1268 /* peek at outbound CCP frames */ 1269 ppp_ccp_peek(ppp, skb, 0); 1270 break; 1271 } 1272 1273 /* try to do packet compression */ 1274 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state && 1275 proto != PPP_LCP && proto != PPP_CCP) { 1276 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) { 1277 if (net_ratelimit()) 1278 netdev_err(ppp->dev, 1279 "ppp: compression required but " 1280 "down - pkt dropped.\n"); 1281 goto drop; 1282 } 1283 skb = pad_compress_skb(ppp, skb); 1284 if (!skb) 1285 goto drop; 1286 } 1287 1288 /* 1289 * If we are waiting for traffic (demand dialling), 1290 * queue it up for pppd to receive. 1291 */ 1292 if (ppp->flags & SC_LOOP_TRAFFIC) { 1293 if (ppp->file.rq.qlen > PPP_MAX_RQLEN) 1294 goto drop; 1295 skb_queue_tail(&ppp->file.rq, skb); 1296 wake_up_interruptible(&ppp->file.rwait); 1297 return; 1298 } 1299 1300 ppp->xmit_pending = skb; 1301 ppp_push(ppp); 1302 return; 1303 1304 drop: 1305 kfree_skb(skb); 1306 ++ppp->dev->stats.tx_errors; 1307 } 1308 1309 /* 1310 * Try to send the frame in xmit_pending. 1311 * The caller should have the xmit path locked. 1312 */ 1313 static void 1314 ppp_push(struct ppp *ppp) 1315 { 1316 struct list_head *list; 1317 struct channel *pch; 1318 struct sk_buff *skb = ppp->xmit_pending; 1319 1320 if (!skb) 1321 return; 1322 1323 list = &ppp->channels; 1324 if (list_empty(list)) { 1325 /* nowhere to send the packet, just drop it */ 1326 ppp->xmit_pending = NULL; 1327 kfree_skb(skb); 1328 return; 1329 } 1330 1331 if ((ppp->flags & SC_MULTILINK) == 0) { 1332 /* not doing multilink: send it down the first channel */ 1333 list = list->next; 1334 pch = list_entry(list, struct channel, clist); 1335 1336 spin_lock_bh(&pch->downl); 1337 if (pch->chan) { 1338 if (pch->chan->ops->start_xmit(pch->chan, skb)) 1339 ppp->xmit_pending = NULL; 1340 } else { 1341 /* channel got unregistered */ 1342 kfree_skb(skb); 1343 ppp->xmit_pending = NULL; 1344 } 1345 spin_unlock_bh(&pch->downl); 1346 return; 1347 } 1348 1349 #ifdef CONFIG_PPP_MULTILINK 1350 /* Multilink: fragment the packet over as many links 1351 as can take the packet at the moment. */ 1352 if (!ppp_mp_explode(ppp, skb)) 1353 return; 1354 #endif /* CONFIG_PPP_MULTILINK */ 1355 1356 ppp->xmit_pending = NULL; 1357 kfree_skb(skb); 1358 } 1359 1360 #ifdef CONFIG_PPP_MULTILINK 1361 static bool mp_protocol_compress __read_mostly = true; 1362 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR); 1363 MODULE_PARM_DESC(mp_protocol_compress, 1364 "compress protocol id in multilink fragments"); 1365 1366 /* 1367 * Divide a packet to be transmitted into fragments and 1368 * send them out the individual links. 1369 */ 1370 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb) 1371 { 1372 int len, totlen; 1373 int i, bits, hdrlen, mtu; 1374 int flen; 1375 int navail, nfree, nzero; 1376 int nbigger; 1377 int totspeed; 1378 int totfree; 1379 unsigned char *p, *q; 1380 struct list_head *list; 1381 struct channel *pch; 1382 struct sk_buff *frag; 1383 struct ppp_channel *chan; 1384 1385 totspeed = 0; /*total bitrate of the bundle*/ 1386 nfree = 0; /* # channels which have no packet already queued */ 1387 navail = 0; /* total # of usable channels (not deregistered) */ 1388 nzero = 0; /* number of channels with zero speed associated*/ 1389 totfree = 0; /*total # of channels available and 1390 *having no queued packets before 1391 *starting the fragmentation*/ 1392 1393 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1394 i = 0; 1395 list_for_each_entry(pch, &ppp->channels, clist) { 1396 if (pch->chan) { 1397 pch->avail = 1; 1398 navail++; 1399 pch->speed = pch->chan->speed; 1400 } else { 1401 pch->avail = 0; 1402 } 1403 if (pch->avail) { 1404 if (skb_queue_empty(&pch->file.xq) || 1405 !pch->had_frag) { 1406 if (pch->speed == 0) 1407 nzero++; 1408 else 1409 totspeed += pch->speed; 1410 1411 pch->avail = 2; 1412 ++nfree; 1413 ++totfree; 1414 } 1415 if (!pch->had_frag && i < ppp->nxchan) 1416 ppp->nxchan = i; 1417 } 1418 ++i; 1419 } 1420 /* 1421 * Don't start sending this packet unless at least half of 1422 * the channels are free. This gives much better TCP 1423 * performance if we have a lot of channels. 1424 */ 1425 if (nfree == 0 || nfree < navail / 2) 1426 return 0; /* can't take now, leave it in xmit_pending */ 1427 1428 /* Do protocol field compression */ 1429 p = skb->data; 1430 len = skb->len; 1431 if (*p == 0 && mp_protocol_compress) { 1432 ++p; 1433 --len; 1434 } 1435 1436 totlen = len; 1437 nbigger = len % nfree; 1438 1439 /* skip to the channel after the one we last used 1440 and start at that one */ 1441 list = &ppp->channels; 1442 for (i = 0; i < ppp->nxchan; ++i) { 1443 list = list->next; 1444 if (list == &ppp->channels) { 1445 i = 0; 1446 break; 1447 } 1448 } 1449 1450 /* create a fragment for each channel */ 1451 bits = B; 1452 while (len > 0) { 1453 list = list->next; 1454 if (list == &ppp->channels) { 1455 i = 0; 1456 continue; 1457 } 1458 pch = list_entry(list, struct channel, clist); 1459 ++i; 1460 if (!pch->avail) 1461 continue; 1462 1463 /* 1464 * Skip this channel if it has a fragment pending already and 1465 * we haven't given a fragment to all of the free channels. 1466 */ 1467 if (pch->avail == 1) { 1468 if (nfree > 0) 1469 continue; 1470 } else { 1471 pch->avail = 1; 1472 } 1473 1474 /* check the channel's mtu and whether it is still attached. */ 1475 spin_lock_bh(&pch->downl); 1476 if (pch->chan == NULL) { 1477 /* can't use this channel, it's being deregistered */ 1478 if (pch->speed == 0) 1479 nzero--; 1480 else 1481 totspeed -= pch->speed; 1482 1483 spin_unlock_bh(&pch->downl); 1484 pch->avail = 0; 1485 totlen = len; 1486 totfree--; 1487 nfree--; 1488 if (--navail == 0) 1489 break; 1490 continue; 1491 } 1492 1493 /* 1494 *if the channel speed is not set divide 1495 *the packet evenly among the free channels; 1496 *otherwise divide it according to the speed 1497 *of the channel we are going to transmit on 1498 */ 1499 flen = len; 1500 if (nfree > 0) { 1501 if (pch->speed == 0) { 1502 flen = len/nfree; 1503 if (nbigger > 0) { 1504 flen++; 1505 nbigger--; 1506 } 1507 } else { 1508 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) / 1509 ((totspeed*totfree)/pch->speed)) - hdrlen; 1510 if (nbigger > 0) { 1511 flen += ((totfree - nzero)*pch->speed)/totspeed; 1512 nbigger -= ((totfree - nzero)*pch->speed)/ 1513 totspeed; 1514 } 1515 } 1516 nfree--; 1517 } 1518 1519 /* 1520 *check if we are on the last channel or 1521 *we exceded the length of the data to 1522 *fragment 1523 */ 1524 if ((nfree <= 0) || (flen > len)) 1525 flen = len; 1526 /* 1527 *it is not worth to tx on slow channels: 1528 *in that case from the resulting flen according to the 1529 *above formula will be equal or less than zero. 1530 *Skip the channel in this case 1531 */ 1532 if (flen <= 0) { 1533 pch->avail = 2; 1534 spin_unlock_bh(&pch->downl); 1535 continue; 1536 } 1537 1538 /* 1539 * hdrlen includes the 2-byte PPP protocol field, but the 1540 * MTU counts only the payload excluding the protocol field. 1541 * (RFC1661 Section 2) 1542 */ 1543 mtu = pch->chan->mtu - (hdrlen - 2); 1544 if (mtu < 4) 1545 mtu = 4; 1546 if (flen > mtu) 1547 flen = mtu; 1548 if (flen == len) 1549 bits |= E; 1550 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC); 1551 if (!frag) 1552 goto noskb; 1553 q = skb_put(frag, flen + hdrlen); 1554 1555 /* make the MP header */ 1556 put_unaligned_be16(PPP_MP, q); 1557 if (ppp->flags & SC_MP_XSHORTSEQ) { 1558 q[2] = bits + ((ppp->nxseq >> 8) & 0xf); 1559 q[3] = ppp->nxseq; 1560 } else { 1561 q[2] = bits; 1562 q[3] = ppp->nxseq >> 16; 1563 q[4] = ppp->nxseq >> 8; 1564 q[5] = ppp->nxseq; 1565 } 1566 1567 memcpy(q + hdrlen, p, flen); 1568 1569 /* try to send it down the channel */ 1570 chan = pch->chan; 1571 if (!skb_queue_empty(&pch->file.xq) || 1572 !chan->ops->start_xmit(chan, frag)) 1573 skb_queue_tail(&pch->file.xq, frag); 1574 pch->had_frag = 1; 1575 p += flen; 1576 len -= flen; 1577 ++ppp->nxseq; 1578 bits = 0; 1579 spin_unlock_bh(&pch->downl); 1580 } 1581 ppp->nxchan = i; 1582 1583 return 1; 1584 1585 noskb: 1586 spin_unlock_bh(&pch->downl); 1587 if (ppp->debug & 1) 1588 netdev_err(ppp->dev, "PPP: no memory (fragment)\n"); 1589 ++ppp->dev->stats.tx_errors; 1590 ++ppp->nxseq; 1591 return 1; /* abandon the frame */ 1592 } 1593 #endif /* CONFIG_PPP_MULTILINK */ 1594 1595 /* 1596 * Try to send data out on a channel. 1597 */ 1598 static void 1599 ppp_channel_push(struct channel *pch) 1600 { 1601 struct sk_buff *skb; 1602 struct ppp *ppp; 1603 1604 spin_lock_bh(&pch->downl); 1605 if (pch->chan) { 1606 while (!skb_queue_empty(&pch->file.xq)) { 1607 skb = skb_dequeue(&pch->file.xq); 1608 if (!pch->chan->ops->start_xmit(pch->chan, skb)) { 1609 /* put the packet back and try again later */ 1610 skb_queue_head(&pch->file.xq, skb); 1611 break; 1612 } 1613 } 1614 } else { 1615 /* channel got deregistered */ 1616 skb_queue_purge(&pch->file.xq); 1617 } 1618 spin_unlock_bh(&pch->downl); 1619 /* see if there is anything from the attached unit to be sent */ 1620 if (skb_queue_empty(&pch->file.xq)) { 1621 read_lock_bh(&pch->upl); 1622 ppp = pch->ppp; 1623 if (ppp) 1624 ppp_xmit_process(ppp); 1625 read_unlock_bh(&pch->upl); 1626 } 1627 } 1628 1629 /* 1630 * Receive-side routines. 1631 */ 1632 1633 struct ppp_mp_skb_parm { 1634 u32 sequence; 1635 u8 BEbits; 1636 }; 1637 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb)) 1638 1639 static inline void 1640 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1641 { 1642 ppp_recv_lock(ppp); 1643 if (!ppp->closing) 1644 ppp_receive_frame(ppp, skb, pch); 1645 else 1646 kfree_skb(skb); 1647 ppp_recv_unlock(ppp); 1648 } 1649 1650 void 1651 ppp_input(struct ppp_channel *chan, struct sk_buff *skb) 1652 { 1653 struct channel *pch = chan->ppp; 1654 int proto; 1655 1656 if (!pch) { 1657 kfree_skb(skb); 1658 return; 1659 } 1660 1661 read_lock_bh(&pch->upl); 1662 if (!pskb_may_pull(skb, 2)) { 1663 kfree_skb(skb); 1664 if (pch->ppp) { 1665 ++pch->ppp->dev->stats.rx_length_errors; 1666 ppp_receive_error(pch->ppp); 1667 } 1668 goto done; 1669 } 1670 1671 proto = PPP_PROTO(skb); 1672 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) { 1673 /* put it on the channel queue */ 1674 skb_queue_tail(&pch->file.rq, skb); 1675 /* drop old frames if queue too long */ 1676 while (pch->file.rq.qlen > PPP_MAX_RQLEN && 1677 (skb = skb_dequeue(&pch->file.rq))) 1678 kfree_skb(skb); 1679 wake_up_interruptible(&pch->file.rwait); 1680 } else { 1681 ppp_do_recv(pch->ppp, skb, pch); 1682 } 1683 1684 done: 1685 read_unlock_bh(&pch->upl); 1686 } 1687 1688 /* Put a 0-length skb in the receive queue as an error indication */ 1689 void 1690 ppp_input_error(struct ppp_channel *chan, int code) 1691 { 1692 struct channel *pch = chan->ppp; 1693 struct sk_buff *skb; 1694 1695 if (!pch) 1696 return; 1697 1698 read_lock_bh(&pch->upl); 1699 if (pch->ppp) { 1700 skb = alloc_skb(0, GFP_ATOMIC); 1701 if (skb) { 1702 skb->len = 0; /* probably unnecessary */ 1703 skb->cb[0] = code; 1704 ppp_do_recv(pch->ppp, skb, pch); 1705 } 1706 } 1707 read_unlock_bh(&pch->upl); 1708 } 1709 1710 /* 1711 * We come in here to process a received frame. 1712 * The receive side of the ppp unit is locked. 1713 */ 1714 static void 1715 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1716 { 1717 /* note: a 0-length skb is used as an error indication */ 1718 if (skb->len > 0) { 1719 #ifdef CONFIG_PPP_MULTILINK 1720 /* XXX do channel-level decompression here */ 1721 if (PPP_PROTO(skb) == PPP_MP) 1722 ppp_receive_mp_frame(ppp, skb, pch); 1723 else 1724 #endif /* CONFIG_PPP_MULTILINK */ 1725 ppp_receive_nonmp_frame(ppp, skb); 1726 } else { 1727 kfree_skb(skb); 1728 ppp_receive_error(ppp); 1729 } 1730 } 1731 1732 static void 1733 ppp_receive_error(struct ppp *ppp) 1734 { 1735 ++ppp->dev->stats.rx_errors; 1736 if (ppp->vj) 1737 slhc_toss(ppp->vj); 1738 } 1739 1740 static void 1741 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) 1742 { 1743 struct sk_buff *ns; 1744 int proto, len, npi; 1745 1746 /* 1747 * Decompress the frame, if compressed. 1748 * Note that some decompressors need to see uncompressed frames 1749 * that come in as well as compressed frames. 1750 */ 1751 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) && 1752 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0) 1753 skb = ppp_decompress_frame(ppp, skb); 1754 1755 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR) 1756 goto err; 1757 1758 proto = PPP_PROTO(skb); 1759 switch (proto) { 1760 case PPP_VJC_COMP: 1761 /* decompress VJ compressed packets */ 1762 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 1763 goto err; 1764 1765 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) { 1766 /* copy to a new sk_buff with more tailroom */ 1767 ns = dev_alloc_skb(skb->len + 128); 1768 if (!ns) { 1769 netdev_err(ppp->dev, "PPP: no memory " 1770 "(VJ decomp)\n"); 1771 goto err; 1772 } 1773 skb_reserve(ns, 2); 1774 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len); 1775 consume_skb(skb); 1776 skb = ns; 1777 } 1778 else 1779 skb->ip_summed = CHECKSUM_NONE; 1780 1781 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2); 1782 if (len <= 0) { 1783 netdev_printk(KERN_DEBUG, ppp->dev, 1784 "PPP: VJ decompression error\n"); 1785 goto err; 1786 } 1787 len += 2; 1788 if (len > skb->len) 1789 skb_put(skb, len - skb->len); 1790 else if (len < skb->len) 1791 skb_trim(skb, len); 1792 proto = PPP_IP; 1793 break; 1794 1795 case PPP_VJC_UNCOMP: 1796 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 1797 goto err; 1798 1799 /* Until we fix the decompressor need to make sure 1800 * data portion is linear. 1801 */ 1802 if (!pskb_may_pull(skb, skb->len)) 1803 goto err; 1804 1805 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) { 1806 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n"); 1807 goto err; 1808 } 1809 proto = PPP_IP; 1810 break; 1811 1812 case PPP_CCP: 1813 ppp_ccp_peek(ppp, skb, 1); 1814 break; 1815 } 1816 1817 ++ppp->stats64.rx_packets; 1818 ppp->stats64.rx_bytes += skb->len - 2; 1819 1820 npi = proto_to_npindex(proto); 1821 if (npi < 0) { 1822 /* control or unknown frame - pass it to pppd */ 1823 skb_queue_tail(&ppp->file.rq, skb); 1824 /* limit queue length by dropping old frames */ 1825 while (ppp->file.rq.qlen > PPP_MAX_RQLEN && 1826 (skb = skb_dequeue(&ppp->file.rq))) 1827 kfree_skb(skb); 1828 /* wake up any process polling or blocking on read */ 1829 wake_up_interruptible(&ppp->file.rwait); 1830 1831 } else { 1832 /* network protocol frame - give it to the kernel */ 1833 1834 #ifdef CONFIG_PPP_FILTER 1835 /* check if the packet passes the pass and active filters */ 1836 /* the filter instructions are constructed assuming 1837 a four-byte PPP header on each packet */ 1838 if (ppp->pass_filter || ppp->active_filter) { 1839 if (skb_unclone(skb, GFP_ATOMIC)) 1840 goto err; 1841 1842 *skb_push(skb, 2) = 0; 1843 if (ppp->pass_filter && 1844 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 1845 if (ppp->debug & 1) 1846 netdev_printk(KERN_DEBUG, ppp->dev, 1847 "PPP: inbound frame " 1848 "not passed\n"); 1849 kfree_skb(skb); 1850 return; 1851 } 1852 if (!(ppp->active_filter && 1853 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 1854 ppp->last_recv = jiffies; 1855 __skb_pull(skb, 2); 1856 } else 1857 #endif /* CONFIG_PPP_FILTER */ 1858 ppp->last_recv = jiffies; 1859 1860 if ((ppp->dev->flags & IFF_UP) == 0 || 1861 ppp->npmode[npi] != NPMODE_PASS) { 1862 kfree_skb(skb); 1863 } else { 1864 /* chop off protocol */ 1865 skb_pull_rcsum(skb, 2); 1866 skb->dev = ppp->dev; 1867 skb->protocol = htons(npindex_to_ethertype[npi]); 1868 skb_reset_mac_header(skb); 1869 netif_rx(skb); 1870 } 1871 } 1872 return; 1873 1874 err: 1875 kfree_skb(skb); 1876 ppp_receive_error(ppp); 1877 } 1878 1879 static struct sk_buff * 1880 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb) 1881 { 1882 int proto = PPP_PROTO(skb); 1883 struct sk_buff *ns; 1884 int len; 1885 1886 /* Until we fix all the decompressor's need to make sure 1887 * data portion is linear. 1888 */ 1889 if (!pskb_may_pull(skb, skb->len)) 1890 goto err; 1891 1892 if (proto == PPP_COMP) { 1893 int obuff_size; 1894 1895 switch(ppp->rcomp->compress_proto) { 1896 case CI_MPPE: 1897 obuff_size = ppp->mru + PPP_HDRLEN + 1; 1898 break; 1899 default: 1900 obuff_size = ppp->mru + PPP_HDRLEN; 1901 break; 1902 } 1903 1904 ns = dev_alloc_skb(obuff_size); 1905 if (!ns) { 1906 netdev_err(ppp->dev, "ppp_decompress_frame: " 1907 "no memory\n"); 1908 goto err; 1909 } 1910 /* the decompressor still expects the A/C bytes in the hdr */ 1911 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2, 1912 skb->len + 2, ns->data, obuff_size); 1913 if (len < 0) { 1914 /* Pass the compressed frame to pppd as an 1915 error indication. */ 1916 if (len == DECOMP_FATALERROR) 1917 ppp->rstate |= SC_DC_FERROR; 1918 kfree_skb(ns); 1919 goto err; 1920 } 1921 1922 consume_skb(skb); 1923 skb = ns; 1924 skb_put(skb, len); 1925 skb_pull(skb, 2); /* pull off the A/C bytes */ 1926 1927 } else { 1928 /* Uncompressed frame - pass to decompressor so it 1929 can update its dictionary if necessary. */ 1930 if (ppp->rcomp->incomp) 1931 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2, 1932 skb->len + 2); 1933 } 1934 1935 return skb; 1936 1937 err: 1938 ppp->rstate |= SC_DC_ERROR; 1939 ppp_receive_error(ppp); 1940 return skb; 1941 } 1942 1943 #ifdef CONFIG_PPP_MULTILINK 1944 /* 1945 * Receive a multilink frame. 1946 * We put it on the reconstruction queue and then pull off 1947 * as many completed frames as we can. 1948 */ 1949 static void 1950 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1951 { 1952 u32 mask, seq; 1953 struct channel *ch; 1954 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1955 1956 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0) 1957 goto err; /* no good, throw it away */ 1958 1959 /* Decode sequence number and begin/end bits */ 1960 if (ppp->flags & SC_MP_SHORTSEQ) { 1961 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3]; 1962 mask = 0xfff; 1963 } else { 1964 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5]; 1965 mask = 0xffffff; 1966 } 1967 PPP_MP_CB(skb)->BEbits = skb->data[2]; 1968 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */ 1969 1970 /* 1971 * Do protocol ID decompression on the first fragment of each packet. 1972 */ 1973 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1)) 1974 *skb_push(skb, 1) = 0; 1975 1976 /* 1977 * Expand sequence number to 32 bits, making it as close 1978 * as possible to ppp->minseq. 1979 */ 1980 seq |= ppp->minseq & ~mask; 1981 if ((int)(ppp->minseq - seq) > (int)(mask >> 1)) 1982 seq += mask + 1; 1983 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1)) 1984 seq -= mask + 1; /* should never happen */ 1985 PPP_MP_CB(skb)->sequence = seq; 1986 pch->lastseq = seq; 1987 1988 /* 1989 * If this packet comes before the next one we were expecting, 1990 * drop it. 1991 */ 1992 if (seq_before(seq, ppp->nextseq)) { 1993 kfree_skb(skb); 1994 ++ppp->dev->stats.rx_dropped; 1995 ppp_receive_error(ppp); 1996 return; 1997 } 1998 1999 /* 2000 * Reevaluate minseq, the minimum over all channels of the 2001 * last sequence number received on each channel. Because of 2002 * the increasing sequence number rule, we know that any fragment 2003 * before `minseq' which hasn't arrived is never going to arrive. 2004 * The list of channels can't change because we have the receive 2005 * side of the ppp unit locked. 2006 */ 2007 list_for_each_entry(ch, &ppp->channels, clist) { 2008 if (seq_before(ch->lastseq, seq)) 2009 seq = ch->lastseq; 2010 } 2011 if (seq_before(ppp->minseq, seq)) 2012 ppp->minseq = seq; 2013 2014 /* Put the fragment on the reconstruction queue */ 2015 ppp_mp_insert(ppp, skb); 2016 2017 /* If the queue is getting long, don't wait any longer for packets 2018 before the start of the queue. */ 2019 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) { 2020 struct sk_buff *mskb = skb_peek(&ppp->mrq); 2021 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence)) 2022 ppp->minseq = PPP_MP_CB(mskb)->sequence; 2023 } 2024 2025 /* Pull completed packets off the queue and receive them. */ 2026 while ((skb = ppp_mp_reconstruct(ppp))) { 2027 if (pskb_may_pull(skb, 2)) 2028 ppp_receive_nonmp_frame(ppp, skb); 2029 else { 2030 ++ppp->dev->stats.rx_length_errors; 2031 kfree_skb(skb); 2032 ppp_receive_error(ppp); 2033 } 2034 } 2035 2036 return; 2037 2038 err: 2039 kfree_skb(skb); 2040 ppp_receive_error(ppp); 2041 } 2042 2043 /* 2044 * Insert a fragment on the MP reconstruction queue. 2045 * The queue is ordered by increasing sequence number. 2046 */ 2047 static void 2048 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb) 2049 { 2050 struct sk_buff *p; 2051 struct sk_buff_head *list = &ppp->mrq; 2052 u32 seq = PPP_MP_CB(skb)->sequence; 2053 2054 /* N.B. we don't need to lock the list lock because we have the 2055 ppp unit receive-side lock. */ 2056 skb_queue_walk(list, p) { 2057 if (seq_before(seq, PPP_MP_CB(p)->sequence)) 2058 break; 2059 } 2060 __skb_queue_before(list, p, skb); 2061 } 2062 2063 /* 2064 * Reconstruct a packet from the MP fragment queue. 2065 * We go through increasing sequence numbers until we find a 2066 * complete packet, or we get to the sequence number for a fragment 2067 * which hasn't arrived but might still do so. 2068 */ 2069 static struct sk_buff * 2070 ppp_mp_reconstruct(struct ppp *ppp) 2071 { 2072 u32 seq = ppp->nextseq; 2073 u32 minseq = ppp->minseq; 2074 struct sk_buff_head *list = &ppp->mrq; 2075 struct sk_buff *p, *tmp; 2076 struct sk_buff *head, *tail; 2077 struct sk_buff *skb = NULL; 2078 int lost = 0, len = 0; 2079 2080 if (ppp->mrru == 0) /* do nothing until mrru is set */ 2081 return NULL; 2082 head = list->next; 2083 tail = NULL; 2084 skb_queue_walk_safe(list, p, tmp) { 2085 again: 2086 if (seq_before(PPP_MP_CB(p)->sequence, seq)) { 2087 /* this can't happen, anyway ignore the skb */ 2088 netdev_err(ppp->dev, "ppp_mp_reconstruct bad " 2089 "seq %u < %u\n", 2090 PPP_MP_CB(p)->sequence, seq); 2091 __skb_unlink(p, list); 2092 kfree_skb(p); 2093 continue; 2094 } 2095 if (PPP_MP_CB(p)->sequence != seq) { 2096 u32 oldseq; 2097 /* Fragment `seq' is missing. If it is after 2098 minseq, it might arrive later, so stop here. */ 2099 if (seq_after(seq, minseq)) 2100 break; 2101 /* Fragment `seq' is lost, keep going. */ 2102 lost = 1; 2103 oldseq = seq; 2104 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)? 2105 minseq + 1: PPP_MP_CB(p)->sequence; 2106 2107 if (ppp->debug & 1) 2108 netdev_printk(KERN_DEBUG, ppp->dev, 2109 "lost frag %u..%u\n", 2110 oldseq, seq-1); 2111 2112 goto again; 2113 } 2114 2115 /* 2116 * At this point we know that all the fragments from 2117 * ppp->nextseq to seq are either present or lost. 2118 * Also, there are no complete packets in the queue 2119 * that have no missing fragments and end before this 2120 * fragment. 2121 */ 2122 2123 /* B bit set indicates this fragment starts a packet */ 2124 if (PPP_MP_CB(p)->BEbits & B) { 2125 head = p; 2126 lost = 0; 2127 len = 0; 2128 } 2129 2130 len += p->len; 2131 2132 /* Got a complete packet yet? */ 2133 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) && 2134 (PPP_MP_CB(head)->BEbits & B)) { 2135 if (len > ppp->mrru + 2) { 2136 ++ppp->dev->stats.rx_length_errors; 2137 netdev_printk(KERN_DEBUG, ppp->dev, 2138 "PPP: reconstructed packet" 2139 " is too long (%d)\n", len); 2140 } else { 2141 tail = p; 2142 break; 2143 } 2144 ppp->nextseq = seq + 1; 2145 } 2146 2147 /* 2148 * If this is the ending fragment of a packet, 2149 * and we haven't found a complete valid packet yet, 2150 * we can discard up to and including this fragment. 2151 */ 2152 if (PPP_MP_CB(p)->BEbits & E) { 2153 struct sk_buff *tmp2; 2154 2155 skb_queue_reverse_walk_from_safe(list, p, tmp2) { 2156 if (ppp->debug & 1) 2157 netdev_printk(KERN_DEBUG, ppp->dev, 2158 "discarding frag %u\n", 2159 PPP_MP_CB(p)->sequence); 2160 __skb_unlink(p, list); 2161 kfree_skb(p); 2162 } 2163 head = skb_peek(list); 2164 if (!head) 2165 break; 2166 } 2167 ++seq; 2168 } 2169 2170 /* If we have a complete packet, copy it all into one skb. */ 2171 if (tail != NULL) { 2172 /* If we have discarded any fragments, 2173 signal a receive error. */ 2174 if (PPP_MP_CB(head)->sequence != ppp->nextseq) { 2175 skb_queue_walk_safe(list, p, tmp) { 2176 if (p == head) 2177 break; 2178 if (ppp->debug & 1) 2179 netdev_printk(KERN_DEBUG, ppp->dev, 2180 "discarding frag %u\n", 2181 PPP_MP_CB(p)->sequence); 2182 __skb_unlink(p, list); 2183 kfree_skb(p); 2184 } 2185 2186 if (ppp->debug & 1) 2187 netdev_printk(KERN_DEBUG, ppp->dev, 2188 " missed pkts %u..%u\n", 2189 ppp->nextseq, 2190 PPP_MP_CB(head)->sequence-1); 2191 ++ppp->dev->stats.rx_dropped; 2192 ppp_receive_error(ppp); 2193 } 2194 2195 skb = head; 2196 if (head != tail) { 2197 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list; 2198 p = skb_queue_next(list, head); 2199 __skb_unlink(skb, list); 2200 skb_queue_walk_from_safe(list, p, tmp) { 2201 __skb_unlink(p, list); 2202 *fragpp = p; 2203 p->next = NULL; 2204 fragpp = &p->next; 2205 2206 skb->len += p->len; 2207 skb->data_len += p->len; 2208 skb->truesize += p->truesize; 2209 2210 if (p == tail) 2211 break; 2212 } 2213 } else { 2214 __skb_unlink(skb, list); 2215 } 2216 2217 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1; 2218 } 2219 2220 return skb; 2221 } 2222 #endif /* CONFIG_PPP_MULTILINK */ 2223 2224 /* 2225 * Channel interface. 2226 */ 2227 2228 /* Create a new, unattached ppp channel. */ 2229 int ppp_register_channel(struct ppp_channel *chan) 2230 { 2231 return ppp_register_net_channel(current->nsproxy->net_ns, chan); 2232 } 2233 2234 /* Create a new, unattached ppp channel for specified net. */ 2235 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan) 2236 { 2237 struct channel *pch; 2238 struct ppp_net *pn; 2239 2240 pch = kzalloc(sizeof(struct channel), GFP_KERNEL); 2241 if (!pch) 2242 return -ENOMEM; 2243 2244 pn = ppp_pernet(net); 2245 2246 pch->ppp = NULL; 2247 pch->chan = chan; 2248 pch->chan_net = net; 2249 chan->ppp = pch; 2250 init_ppp_file(&pch->file, CHANNEL); 2251 pch->file.hdrlen = chan->hdrlen; 2252 #ifdef CONFIG_PPP_MULTILINK 2253 pch->lastseq = -1; 2254 #endif /* CONFIG_PPP_MULTILINK */ 2255 init_rwsem(&pch->chan_sem); 2256 spin_lock_init(&pch->downl); 2257 rwlock_init(&pch->upl); 2258 2259 spin_lock_bh(&pn->all_channels_lock); 2260 pch->file.index = ++pn->last_channel_index; 2261 list_add(&pch->list, &pn->new_channels); 2262 atomic_inc(&channel_count); 2263 spin_unlock_bh(&pn->all_channels_lock); 2264 2265 return 0; 2266 } 2267 2268 /* 2269 * Return the index of a channel. 2270 */ 2271 int ppp_channel_index(struct ppp_channel *chan) 2272 { 2273 struct channel *pch = chan->ppp; 2274 2275 if (pch) 2276 return pch->file.index; 2277 return -1; 2278 } 2279 2280 /* 2281 * Return the PPP unit number to which a channel is connected. 2282 */ 2283 int ppp_unit_number(struct ppp_channel *chan) 2284 { 2285 struct channel *pch = chan->ppp; 2286 int unit = -1; 2287 2288 if (pch) { 2289 read_lock_bh(&pch->upl); 2290 if (pch->ppp) 2291 unit = pch->ppp->file.index; 2292 read_unlock_bh(&pch->upl); 2293 } 2294 return unit; 2295 } 2296 2297 /* 2298 * Return the PPP device interface name of a channel. 2299 */ 2300 char *ppp_dev_name(struct ppp_channel *chan) 2301 { 2302 struct channel *pch = chan->ppp; 2303 char *name = NULL; 2304 2305 if (pch) { 2306 read_lock_bh(&pch->upl); 2307 if (pch->ppp && pch->ppp->dev) 2308 name = pch->ppp->dev->name; 2309 read_unlock_bh(&pch->upl); 2310 } 2311 return name; 2312 } 2313 2314 2315 /* 2316 * Disconnect a channel from the generic layer. 2317 * This must be called in process context. 2318 */ 2319 void 2320 ppp_unregister_channel(struct ppp_channel *chan) 2321 { 2322 struct channel *pch = chan->ppp; 2323 struct ppp_net *pn; 2324 2325 if (!pch) 2326 return; /* should never happen */ 2327 2328 chan->ppp = NULL; 2329 2330 /* 2331 * This ensures that we have returned from any calls into the 2332 * the channel's start_xmit or ioctl routine before we proceed. 2333 */ 2334 down_write(&pch->chan_sem); 2335 spin_lock_bh(&pch->downl); 2336 pch->chan = NULL; 2337 spin_unlock_bh(&pch->downl); 2338 up_write(&pch->chan_sem); 2339 ppp_disconnect_channel(pch); 2340 2341 pn = ppp_pernet(pch->chan_net); 2342 spin_lock_bh(&pn->all_channels_lock); 2343 list_del(&pch->list); 2344 spin_unlock_bh(&pn->all_channels_lock); 2345 2346 pch->file.dead = 1; 2347 wake_up_interruptible(&pch->file.rwait); 2348 if (atomic_dec_and_test(&pch->file.refcnt)) 2349 ppp_destroy_channel(pch); 2350 } 2351 2352 /* 2353 * Callback from a channel when it can accept more to transmit. 2354 * This should be called at BH/softirq level, not interrupt level. 2355 */ 2356 void 2357 ppp_output_wakeup(struct ppp_channel *chan) 2358 { 2359 struct channel *pch = chan->ppp; 2360 2361 if (!pch) 2362 return; 2363 ppp_channel_push(pch); 2364 } 2365 2366 /* 2367 * Compression control. 2368 */ 2369 2370 /* Process the PPPIOCSCOMPRESS ioctl. */ 2371 static int 2372 ppp_set_compress(struct ppp *ppp, unsigned long arg) 2373 { 2374 int err; 2375 struct compressor *cp, *ocomp; 2376 struct ppp_option_data data; 2377 void *state, *ostate; 2378 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH]; 2379 2380 err = -EFAULT; 2381 if (copy_from_user(&data, (void __user *) arg, sizeof(data)) || 2382 (data.length <= CCP_MAX_OPTION_LENGTH && 2383 copy_from_user(ccp_option, (void __user *) data.ptr, data.length))) 2384 goto out; 2385 err = -EINVAL; 2386 if (data.length > CCP_MAX_OPTION_LENGTH || 2387 ccp_option[1] < 2 || ccp_option[1] > data.length) 2388 goto out; 2389 2390 cp = try_then_request_module( 2391 find_compressor(ccp_option[0]), 2392 "ppp-compress-%d", ccp_option[0]); 2393 if (!cp) 2394 goto out; 2395 2396 err = -ENOBUFS; 2397 if (data.transmit) { 2398 state = cp->comp_alloc(ccp_option, data.length); 2399 if (state) { 2400 ppp_xmit_lock(ppp); 2401 ppp->xstate &= ~SC_COMP_RUN; 2402 ocomp = ppp->xcomp; 2403 ostate = ppp->xc_state; 2404 ppp->xcomp = cp; 2405 ppp->xc_state = state; 2406 ppp_xmit_unlock(ppp); 2407 if (ostate) { 2408 ocomp->comp_free(ostate); 2409 module_put(ocomp->owner); 2410 } 2411 err = 0; 2412 } else 2413 module_put(cp->owner); 2414 2415 } else { 2416 state = cp->decomp_alloc(ccp_option, data.length); 2417 if (state) { 2418 ppp_recv_lock(ppp); 2419 ppp->rstate &= ~SC_DECOMP_RUN; 2420 ocomp = ppp->rcomp; 2421 ostate = ppp->rc_state; 2422 ppp->rcomp = cp; 2423 ppp->rc_state = state; 2424 ppp_recv_unlock(ppp); 2425 if (ostate) { 2426 ocomp->decomp_free(ostate); 2427 module_put(ocomp->owner); 2428 } 2429 err = 0; 2430 } else 2431 module_put(cp->owner); 2432 } 2433 2434 out: 2435 return err; 2436 } 2437 2438 /* 2439 * Look at a CCP packet and update our state accordingly. 2440 * We assume the caller has the xmit or recv path locked. 2441 */ 2442 static void 2443 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound) 2444 { 2445 unsigned char *dp; 2446 int len; 2447 2448 if (!pskb_may_pull(skb, CCP_HDRLEN + 2)) 2449 return; /* no header */ 2450 dp = skb->data + 2; 2451 2452 switch (CCP_CODE(dp)) { 2453 case CCP_CONFREQ: 2454 2455 /* A ConfReq starts negotiation of compression 2456 * in one direction of transmission, 2457 * and hence brings it down...but which way? 2458 * 2459 * Remember: 2460 * A ConfReq indicates what the sender would like to receive 2461 */ 2462 if(inbound) 2463 /* He is proposing what I should send */ 2464 ppp->xstate &= ~SC_COMP_RUN; 2465 else 2466 /* I am proposing to what he should send */ 2467 ppp->rstate &= ~SC_DECOMP_RUN; 2468 2469 break; 2470 2471 case CCP_TERMREQ: 2472 case CCP_TERMACK: 2473 /* 2474 * CCP is going down, both directions of transmission 2475 */ 2476 ppp->rstate &= ~SC_DECOMP_RUN; 2477 ppp->xstate &= ~SC_COMP_RUN; 2478 break; 2479 2480 case CCP_CONFACK: 2481 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN) 2482 break; 2483 len = CCP_LENGTH(dp); 2484 if (!pskb_may_pull(skb, len + 2)) 2485 return; /* too short */ 2486 dp += CCP_HDRLEN; 2487 len -= CCP_HDRLEN; 2488 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp)) 2489 break; 2490 if (inbound) { 2491 /* we will start receiving compressed packets */ 2492 if (!ppp->rc_state) 2493 break; 2494 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len, 2495 ppp->file.index, 0, ppp->mru, ppp->debug)) { 2496 ppp->rstate |= SC_DECOMP_RUN; 2497 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR); 2498 } 2499 } else { 2500 /* we will soon start sending compressed packets */ 2501 if (!ppp->xc_state) 2502 break; 2503 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len, 2504 ppp->file.index, 0, ppp->debug)) 2505 ppp->xstate |= SC_COMP_RUN; 2506 } 2507 break; 2508 2509 case CCP_RESETACK: 2510 /* reset the [de]compressor */ 2511 if ((ppp->flags & SC_CCP_UP) == 0) 2512 break; 2513 if (inbound) { 2514 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) { 2515 ppp->rcomp->decomp_reset(ppp->rc_state); 2516 ppp->rstate &= ~SC_DC_ERROR; 2517 } 2518 } else { 2519 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN)) 2520 ppp->xcomp->comp_reset(ppp->xc_state); 2521 } 2522 break; 2523 } 2524 } 2525 2526 /* Free up compression resources. */ 2527 static void 2528 ppp_ccp_closed(struct ppp *ppp) 2529 { 2530 void *xstate, *rstate; 2531 struct compressor *xcomp, *rcomp; 2532 2533 ppp_lock(ppp); 2534 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP); 2535 ppp->xstate = 0; 2536 xcomp = ppp->xcomp; 2537 xstate = ppp->xc_state; 2538 ppp->xc_state = NULL; 2539 ppp->rstate = 0; 2540 rcomp = ppp->rcomp; 2541 rstate = ppp->rc_state; 2542 ppp->rc_state = NULL; 2543 ppp_unlock(ppp); 2544 2545 if (xstate) { 2546 xcomp->comp_free(xstate); 2547 module_put(xcomp->owner); 2548 } 2549 if (rstate) { 2550 rcomp->decomp_free(rstate); 2551 module_put(rcomp->owner); 2552 } 2553 } 2554 2555 /* List of compressors. */ 2556 static LIST_HEAD(compressor_list); 2557 static DEFINE_SPINLOCK(compressor_list_lock); 2558 2559 struct compressor_entry { 2560 struct list_head list; 2561 struct compressor *comp; 2562 }; 2563 2564 static struct compressor_entry * 2565 find_comp_entry(int proto) 2566 { 2567 struct compressor_entry *ce; 2568 2569 list_for_each_entry(ce, &compressor_list, list) { 2570 if (ce->comp->compress_proto == proto) 2571 return ce; 2572 } 2573 return NULL; 2574 } 2575 2576 /* Register a compressor */ 2577 int 2578 ppp_register_compressor(struct compressor *cp) 2579 { 2580 struct compressor_entry *ce; 2581 int ret; 2582 spin_lock(&compressor_list_lock); 2583 ret = -EEXIST; 2584 if (find_comp_entry(cp->compress_proto)) 2585 goto out; 2586 ret = -ENOMEM; 2587 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC); 2588 if (!ce) 2589 goto out; 2590 ret = 0; 2591 ce->comp = cp; 2592 list_add(&ce->list, &compressor_list); 2593 out: 2594 spin_unlock(&compressor_list_lock); 2595 return ret; 2596 } 2597 2598 /* Unregister a compressor */ 2599 void 2600 ppp_unregister_compressor(struct compressor *cp) 2601 { 2602 struct compressor_entry *ce; 2603 2604 spin_lock(&compressor_list_lock); 2605 ce = find_comp_entry(cp->compress_proto); 2606 if (ce && ce->comp == cp) { 2607 list_del(&ce->list); 2608 kfree(ce); 2609 } 2610 spin_unlock(&compressor_list_lock); 2611 } 2612 2613 /* Find a compressor. */ 2614 static struct compressor * 2615 find_compressor(int type) 2616 { 2617 struct compressor_entry *ce; 2618 struct compressor *cp = NULL; 2619 2620 spin_lock(&compressor_list_lock); 2621 ce = find_comp_entry(type); 2622 if (ce) { 2623 cp = ce->comp; 2624 if (!try_module_get(cp->owner)) 2625 cp = NULL; 2626 } 2627 spin_unlock(&compressor_list_lock); 2628 return cp; 2629 } 2630 2631 /* 2632 * Miscelleneous stuff. 2633 */ 2634 2635 static void 2636 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st) 2637 { 2638 struct slcompress *vj = ppp->vj; 2639 2640 memset(st, 0, sizeof(*st)); 2641 st->p.ppp_ipackets = ppp->stats64.rx_packets; 2642 st->p.ppp_ierrors = ppp->dev->stats.rx_errors; 2643 st->p.ppp_ibytes = ppp->stats64.rx_bytes; 2644 st->p.ppp_opackets = ppp->stats64.tx_packets; 2645 st->p.ppp_oerrors = ppp->dev->stats.tx_errors; 2646 st->p.ppp_obytes = ppp->stats64.tx_bytes; 2647 if (!vj) 2648 return; 2649 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed; 2650 st->vj.vjs_compressed = vj->sls_o_compressed; 2651 st->vj.vjs_searches = vj->sls_o_searches; 2652 st->vj.vjs_misses = vj->sls_o_misses; 2653 st->vj.vjs_errorin = vj->sls_i_error; 2654 st->vj.vjs_tossed = vj->sls_i_tossed; 2655 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed; 2656 st->vj.vjs_compressedin = vj->sls_i_compressed; 2657 } 2658 2659 /* 2660 * Stuff for handling the lists of ppp units and channels 2661 * and for initialization. 2662 */ 2663 2664 /* 2665 * Create a new ppp interface unit. Fails if it can't allocate memory 2666 * or if there is already a unit with the requested number. 2667 * unit == -1 means allocate a new number. 2668 */ 2669 static struct ppp * 2670 ppp_create_interface(struct net *net, int unit, int *retp) 2671 { 2672 struct ppp *ppp; 2673 struct ppp_net *pn; 2674 struct net_device *dev = NULL; 2675 int ret = -ENOMEM; 2676 int i; 2677 2678 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_UNKNOWN, 2679 ppp_setup); 2680 if (!dev) 2681 goto out1; 2682 2683 pn = ppp_pernet(net); 2684 2685 ppp = netdev_priv(dev); 2686 ppp->dev = dev; 2687 ppp->mru = PPP_MRU; 2688 init_ppp_file(&ppp->file, INTERFACE); 2689 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */ 2690 for (i = 0; i < NUM_NP; ++i) 2691 ppp->npmode[i] = NPMODE_PASS; 2692 INIT_LIST_HEAD(&ppp->channels); 2693 spin_lock_init(&ppp->rlock); 2694 spin_lock_init(&ppp->wlock); 2695 #ifdef CONFIG_PPP_MULTILINK 2696 ppp->minseq = -1; 2697 skb_queue_head_init(&ppp->mrq); 2698 #endif /* CONFIG_PPP_MULTILINK */ 2699 #ifdef CONFIG_PPP_FILTER 2700 ppp->pass_filter = NULL; 2701 ppp->active_filter = NULL; 2702 #endif /* CONFIG_PPP_FILTER */ 2703 2704 /* 2705 * drum roll: don't forget to set 2706 * the net device is belong to 2707 */ 2708 dev_net_set(dev, net); 2709 2710 mutex_lock(&pn->all_ppp_mutex); 2711 2712 if (unit < 0) { 2713 unit = unit_get(&pn->units_idr, ppp); 2714 if (unit < 0) { 2715 ret = unit; 2716 goto out2; 2717 } 2718 } else { 2719 ret = -EEXIST; 2720 if (unit_find(&pn->units_idr, unit)) 2721 goto out2; /* unit already exists */ 2722 /* 2723 * if caller need a specified unit number 2724 * lets try to satisfy him, otherwise -- 2725 * he should better ask us for new unit number 2726 * 2727 * NOTE: yes I know that returning EEXIST it's not 2728 * fair but at least pppd will ask us to allocate 2729 * new unit in this case so user is happy :) 2730 */ 2731 unit = unit_set(&pn->units_idr, ppp, unit); 2732 if (unit < 0) 2733 goto out2; 2734 } 2735 2736 /* Initialize the new ppp unit */ 2737 ppp->file.index = unit; 2738 sprintf(dev->name, "ppp%d", unit); 2739 2740 ret = register_netdev(dev); 2741 if (ret != 0) { 2742 unit_put(&pn->units_idr, unit); 2743 netdev_err(ppp->dev, "PPP: couldn't register device %s (%d)\n", 2744 dev->name, ret); 2745 goto out2; 2746 } 2747 2748 ppp->ppp_net = net; 2749 2750 atomic_inc(&ppp_unit_count); 2751 mutex_unlock(&pn->all_ppp_mutex); 2752 2753 *retp = 0; 2754 return ppp; 2755 2756 out2: 2757 mutex_unlock(&pn->all_ppp_mutex); 2758 free_netdev(dev); 2759 out1: 2760 *retp = ret; 2761 return NULL; 2762 } 2763 2764 /* 2765 * Initialize a ppp_file structure. 2766 */ 2767 static void 2768 init_ppp_file(struct ppp_file *pf, int kind) 2769 { 2770 pf->kind = kind; 2771 skb_queue_head_init(&pf->xq); 2772 skb_queue_head_init(&pf->rq); 2773 atomic_set(&pf->refcnt, 1); 2774 init_waitqueue_head(&pf->rwait); 2775 } 2776 2777 /* 2778 * Take down a ppp interface unit - called when the owning file 2779 * (the one that created the unit) is closed or detached. 2780 */ 2781 static void ppp_shutdown_interface(struct ppp *ppp) 2782 { 2783 struct ppp_net *pn; 2784 2785 pn = ppp_pernet(ppp->ppp_net); 2786 mutex_lock(&pn->all_ppp_mutex); 2787 2788 /* This will call dev_close() for us. */ 2789 ppp_lock(ppp); 2790 if (!ppp->closing) { 2791 ppp->closing = 1; 2792 ppp_unlock(ppp); 2793 unregister_netdev(ppp->dev); 2794 unit_put(&pn->units_idr, ppp->file.index); 2795 } else 2796 ppp_unlock(ppp); 2797 2798 ppp->file.dead = 1; 2799 ppp->owner = NULL; 2800 wake_up_interruptible(&ppp->file.rwait); 2801 2802 mutex_unlock(&pn->all_ppp_mutex); 2803 } 2804 2805 /* 2806 * Free the memory used by a ppp unit. This is only called once 2807 * there are no channels connected to the unit and no file structs 2808 * that reference the unit. 2809 */ 2810 static void ppp_destroy_interface(struct ppp *ppp) 2811 { 2812 atomic_dec(&ppp_unit_count); 2813 2814 if (!ppp->file.dead || ppp->n_channels) { 2815 /* "can't happen" */ 2816 netdev_err(ppp->dev, "ppp: destroying ppp struct %p " 2817 "but dead=%d n_channels=%d !\n", 2818 ppp, ppp->file.dead, ppp->n_channels); 2819 return; 2820 } 2821 2822 ppp_ccp_closed(ppp); 2823 if (ppp->vj) { 2824 slhc_free(ppp->vj); 2825 ppp->vj = NULL; 2826 } 2827 skb_queue_purge(&ppp->file.xq); 2828 skb_queue_purge(&ppp->file.rq); 2829 #ifdef CONFIG_PPP_MULTILINK 2830 skb_queue_purge(&ppp->mrq); 2831 #endif /* CONFIG_PPP_MULTILINK */ 2832 #ifdef CONFIG_PPP_FILTER 2833 if (ppp->pass_filter) { 2834 bpf_prog_destroy(ppp->pass_filter); 2835 ppp->pass_filter = NULL; 2836 } 2837 2838 if (ppp->active_filter) { 2839 bpf_prog_destroy(ppp->active_filter); 2840 ppp->active_filter = NULL; 2841 } 2842 #endif /* CONFIG_PPP_FILTER */ 2843 2844 kfree_skb(ppp->xmit_pending); 2845 2846 free_netdev(ppp->dev); 2847 } 2848 2849 /* 2850 * Locate an existing ppp unit. 2851 * The caller should have locked the all_ppp_mutex. 2852 */ 2853 static struct ppp * 2854 ppp_find_unit(struct ppp_net *pn, int unit) 2855 { 2856 return unit_find(&pn->units_idr, unit); 2857 } 2858 2859 /* 2860 * Locate an existing ppp channel. 2861 * The caller should have locked the all_channels_lock. 2862 * First we look in the new_channels list, then in the 2863 * all_channels list. If found in the new_channels list, 2864 * we move it to the all_channels list. This is for speed 2865 * when we have a lot of channels in use. 2866 */ 2867 static struct channel * 2868 ppp_find_channel(struct ppp_net *pn, int unit) 2869 { 2870 struct channel *pch; 2871 2872 list_for_each_entry(pch, &pn->new_channels, list) { 2873 if (pch->file.index == unit) { 2874 list_move(&pch->list, &pn->all_channels); 2875 return pch; 2876 } 2877 } 2878 2879 list_for_each_entry(pch, &pn->all_channels, list) { 2880 if (pch->file.index == unit) 2881 return pch; 2882 } 2883 2884 return NULL; 2885 } 2886 2887 /* 2888 * Connect a PPP channel to a PPP interface unit. 2889 */ 2890 static int 2891 ppp_connect_channel(struct channel *pch, int unit) 2892 { 2893 struct ppp *ppp; 2894 struct ppp_net *pn; 2895 int ret = -ENXIO; 2896 int hdrlen; 2897 2898 pn = ppp_pernet(pch->chan_net); 2899 2900 mutex_lock(&pn->all_ppp_mutex); 2901 ppp = ppp_find_unit(pn, unit); 2902 if (!ppp) 2903 goto out; 2904 write_lock_bh(&pch->upl); 2905 ret = -EINVAL; 2906 if (pch->ppp) 2907 goto outl; 2908 2909 ppp_lock(ppp); 2910 if (pch->file.hdrlen > ppp->file.hdrlen) 2911 ppp->file.hdrlen = pch->file.hdrlen; 2912 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */ 2913 if (hdrlen > ppp->dev->hard_header_len) 2914 ppp->dev->hard_header_len = hdrlen; 2915 list_add_tail(&pch->clist, &ppp->channels); 2916 ++ppp->n_channels; 2917 pch->ppp = ppp; 2918 atomic_inc(&ppp->file.refcnt); 2919 ppp_unlock(ppp); 2920 ret = 0; 2921 2922 outl: 2923 write_unlock_bh(&pch->upl); 2924 out: 2925 mutex_unlock(&pn->all_ppp_mutex); 2926 return ret; 2927 } 2928 2929 /* 2930 * Disconnect a channel from its ppp unit. 2931 */ 2932 static int 2933 ppp_disconnect_channel(struct channel *pch) 2934 { 2935 struct ppp *ppp; 2936 int err = -EINVAL; 2937 2938 write_lock_bh(&pch->upl); 2939 ppp = pch->ppp; 2940 pch->ppp = NULL; 2941 write_unlock_bh(&pch->upl); 2942 if (ppp) { 2943 /* remove it from the ppp unit's list */ 2944 ppp_lock(ppp); 2945 list_del(&pch->clist); 2946 if (--ppp->n_channels == 0) 2947 wake_up_interruptible(&ppp->file.rwait); 2948 ppp_unlock(ppp); 2949 if (atomic_dec_and_test(&ppp->file.refcnt)) 2950 ppp_destroy_interface(ppp); 2951 err = 0; 2952 } 2953 return err; 2954 } 2955 2956 /* 2957 * Free up the resources used by a ppp channel. 2958 */ 2959 static void ppp_destroy_channel(struct channel *pch) 2960 { 2961 atomic_dec(&channel_count); 2962 2963 if (!pch->file.dead) { 2964 /* "can't happen" */ 2965 pr_err("ppp: destroying undead channel %p !\n", pch); 2966 return; 2967 } 2968 skb_queue_purge(&pch->file.xq); 2969 skb_queue_purge(&pch->file.rq); 2970 kfree(pch); 2971 } 2972 2973 static void __exit ppp_cleanup(void) 2974 { 2975 /* should never happen */ 2976 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count)) 2977 pr_err("PPP: removing module but units remain!\n"); 2978 unregister_chrdev(PPP_MAJOR, "ppp"); 2979 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0)); 2980 class_destroy(ppp_class); 2981 unregister_pernet_device(&ppp_net_ops); 2982 } 2983 2984 /* 2985 * Units handling. Caller must protect concurrent access 2986 * by holding all_ppp_mutex 2987 */ 2988 2989 /* associate pointer with specified number */ 2990 static int unit_set(struct idr *p, void *ptr, int n) 2991 { 2992 int unit; 2993 2994 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL); 2995 if (unit == -ENOSPC) 2996 unit = -EINVAL; 2997 return unit; 2998 } 2999 3000 /* get new free unit number and associate pointer with it */ 3001 static int unit_get(struct idr *p, void *ptr) 3002 { 3003 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL); 3004 } 3005 3006 /* put unit number back to a pool */ 3007 static void unit_put(struct idr *p, int n) 3008 { 3009 idr_remove(p, n); 3010 } 3011 3012 /* get pointer associated with the number */ 3013 static void *unit_find(struct idr *p, int n) 3014 { 3015 return idr_find(p, n); 3016 } 3017 3018 /* Module/initialization stuff */ 3019 3020 module_init(ppp_init); 3021 module_exit(ppp_cleanup); 3022 3023 EXPORT_SYMBOL(ppp_register_net_channel); 3024 EXPORT_SYMBOL(ppp_register_channel); 3025 EXPORT_SYMBOL(ppp_unregister_channel); 3026 EXPORT_SYMBOL(ppp_channel_index); 3027 EXPORT_SYMBOL(ppp_unit_number); 3028 EXPORT_SYMBOL(ppp_dev_name); 3029 EXPORT_SYMBOL(ppp_input); 3030 EXPORT_SYMBOL(ppp_input_error); 3031 EXPORT_SYMBOL(ppp_output_wakeup); 3032 EXPORT_SYMBOL(ppp_register_compressor); 3033 EXPORT_SYMBOL(ppp_unregister_compressor); 3034 MODULE_LICENSE("GPL"); 3035 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0); 3036 MODULE_ALIAS("devname:ppp"); 3037