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, 273 struct file *file, int *retp); 274 static void init_ppp_file(struct ppp_file *pf, int kind); 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 rtnl_lock(); 396 if (file == ppp->owner) 397 unregister_netdevice(ppp->dev); 398 rtnl_unlock(); 399 } 400 if (atomic_dec_and_test(&pf->refcnt)) { 401 switch (pf->kind) { 402 case INTERFACE: 403 ppp_destroy_interface(PF_TO_PPP(pf)); 404 break; 405 case CHANNEL: 406 ppp_destroy_channel(PF_TO_CHANNEL(pf)); 407 break; 408 } 409 } 410 } 411 return 0; 412 } 413 414 static ssize_t ppp_read(struct file *file, char __user *buf, 415 size_t count, loff_t *ppos) 416 { 417 struct ppp_file *pf = file->private_data; 418 DECLARE_WAITQUEUE(wait, current); 419 ssize_t ret; 420 struct sk_buff *skb = NULL; 421 struct iovec iov; 422 struct iov_iter to; 423 424 ret = count; 425 426 if (!pf) 427 return -ENXIO; 428 add_wait_queue(&pf->rwait, &wait); 429 for (;;) { 430 set_current_state(TASK_INTERRUPTIBLE); 431 skb = skb_dequeue(&pf->rq); 432 if (skb) 433 break; 434 ret = 0; 435 if (pf->dead) 436 break; 437 if (pf->kind == INTERFACE) { 438 /* 439 * Return 0 (EOF) on an interface that has no 440 * channels connected, unless it is looping 441 * network traffic (demand mode). 442 */ 443 struct ppp *ppp = PF_TO_PPP(pf); 444 if (ppp->n_channels == 0 && 445 (ppp->flags & SC_LOOP_TRAFFIC) == 0) 446 break; 447 } 448 ret = -EAGAIN; 449 if (file->f_flags & O_NONBLOCK) 450 break; 451 ret = -ERESTARTSYS; 452 if (signal_pending(current)) 453 break; 454 schedule(); 455 } 456 set_current_state(TASK_RUNNING); 457 remove_wait_queue(&pf->rwait, &wait); 458 459 if (!skb) 460 goto out; 461 462 ret = -EOVERFLOW; 463 if (skb->len > count) 464 goto outf; 465 ret = -EFAULT; 466 iov.iov_base = buf; 467 iov.iov_len = count; 468 iov_iter_init(&to, READ, &iov, 1, count); 469 if (skb_copy_datagram_iter(skb, 0, &to, skb->len)) 470 goto outf; 471 ret = skb->len; 472 473 outf: 474 kfree_skb(skb); 475 out: 476 return ret; 477 } 478 479 static ssize_t ppp_write(struct file *file, const char __user *buf, 480 size_t count, loff_t *ppos) 481 { 482 struct ppp_file *pf = file->private_data; 483 struct sk_buff *skb; 484 ssize_t ret; 485 486 if (!pf) 487 return -ENXIO; 488 ret = -ENOMEM; 489 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL); 490 if (!skb) 491 goto out; 492 skb_reserve(skb, pf->hdrlen); 493 ret = -EFAULT; 494 if (copy_from_user(skb_put(skb, count), buf, count)) { 495 kfree_skb(skb); 496 goto out; 497 } 498 499 skb_queue_tail(&pf->xq, skb); 500 501 switch (pf->kind) { 502 case INTERFACE: 503 ppp_xmit_process(PF_TO_PPP(pf)); 504 break; 505 case CHANNEL: 506 ppp_channel_push(PF_TO_CHANNEL(pf)); 507 break; 508 } 509 510 ret = count; 511 512 out: 513 return ret; 514 } 515 516 /* No kernel lock - fine */ 517 static unsigned int ppp_poll(struct file *file, poll_table *wait) 518 { 519 struct ppp_file *pf = file->private_data; 520 unsigned int mask; 521 522 if (!pf) 523 return 0; 524 poll_wait(file, &pf->rwait, wait); 525 mask = POLLOUT | POLLWRNORM; 526 if (skb_peek(&pf->rq)) 527 mask |= POLLIN | POLLRDNORM; 528 if (pf->dead) 529 mask |= POLLHUP; 530 else if (pf->kind == INTERFACE) { 531 /* see comment in ppp_read */ 532 struct ppp *ppp = PF_TO_PPP(pf); 533 if (ppp->n_channels == 0 && 534 (ppp->flags & SC_LOOP_TRAFFIC) == 0) 535 mask |= POLLIN | POLLRDNORM; 536 } 537 538 return mask; 539 } 540 541 #ifdef CONFIG_PPP_FILTER 542 static int get_filter(void __user *arg, struct sock_filter **p) 543 { 544 struct sock_fprog uprog; 545 struct sock_filter *code = NULL; 546 int len; 547 548 if (copy_from_user(&uprog, arg, sizeof(uprog))) 549 return -EFAULT; 550 551 if (!uprog.len) { 552 *p = NULL; 553 return 0; 554 } 555 556 len = uprog.len * sizeof(struct sock_filter); 557 code = memdup_user(uprog.filter, len); 558 if (IS_ERR(code)) 559 return PTR_ERR(code); 560 561 *p = code; 562 return uprog.len; 563 } 564 #endif /* CONFIG_PPP_FILTER */ 565 566 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 567 { 568 struct ppp_file *pf = file->private_data; 569 struct ppp *ppp; 570 int err = -EFAULT, val, val2, i; 571 struct ppp_idle idle; 572 struct npioctl npi; 573 int unit, cflags; 574 struct slcompress *vj; 575 void __user *argp = (void __user *)arg; 576 int __user *p = argp; 577 578 if (!pf) 579 return ppp_unattached_ioctl(current->nsproxy->net_ns, 580 pf, file, cmd, arg); 581 582 if (cmd == PPPIOCDETACH) { 583 /* 584 * We have to be careful here... if the file descriptor 585 * has been dup'd, we could have another process in the 586 * middle of a poll using the same file *, so we had 587 * better not free the interface data structures - 588 * instead we fail the ioctl. Even in this case, we 589 * shut down the interface if we are the owner of it. 590 * Actually, we should get rid of PPPIOCDETACH, userland 591 * (i.e. pppd) could achieve the same effect by closing 592 * this fd and reopening /dev/ppp. 593 */ 594 err = -EINVAL; 595 mutex_lock(&ppp_mutex); 596 if (pf->kind == INTERFACE) { 597 ppp = PF_TO_PPP(pf); 598 rtnl_lock(); 599 if (file == ppp->owner) 600 unregister_netdevice(ppp->dev); 601 rtnl_unlock(); 602 } 603 if (atomic_long_read(&file->f_count) < 2) { 604 ppp_release(NULL, file); 605 err = 0; 606 } else 607 pr_warn("PPPIOCDETACH file->f_count=%ld\n", 608 atomic_long_read(&file->f_count)); 609 mutex_unlock(&ppp_mutex); 610 return err; 611 } 612 613 if (pf->kind == CHANNEL) { 614 struct channel *pch; 615 struct ppp_channel *chan; 616 617 mutex_lock(&ppp_mutex); 618 pch = PF_TO_CHANNEL(pf); 619 620 switch (cmd) { 621 case PPPIOCCONNECT: 622 if (get_user(unit, p)) 623 break; 624 err = ppp_connect_channel(pch, unit); 625 break; 626 627 case PPPIOCDISCONN: 628 err = ppp_disconnect_channel(pch); 629 break; 630 631 default: 632 down_read(&pch->chan_sem); 633 chan = pch->chan; 634 err = -ENOTTY; 635 if (chan && chan->ops->ioctl) 636 err = chan->ops->ioctl(chan, cmd, arg); 637 up_read(&pch->chan_sem); 638 } 639 mutex_unlock(&ppp_mutex); 640 return err; 641 } 642 643 if (pf->kind != INTERFACE) { 644 /* can't happen */ 645 pr_err("PPP: not interface or channel??\n"); 646 return -EINVAL; 647 } 648 649 mutex_lock(&ppp_mutex); 650 ppp = PF_TO_PPP(pf); 651 switch (cmd) { 652 case PPPIOCSMRU: 653 if (get_user(val, p)) 654 break; 655 ppp->mru = val; 656 err = 0; 657 break; 658 659 case PPPIOCSFLAGS: 660 if (get_user(val, p)) 661 break; 662 ppp_lock(ppp); 663 cflags = ppp->flags & ~val; 664 #ifdef CONFIG_PPP_MULTILINK 665 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK)) 666 ppp->nextseq = 0; 667 #endif 668 ppp->flags = val & SC_FLAG_BITS; 669 ppp_unlock(ppp); 670 if (cflags & SC_CCP_OPEN) 671 ppp_ccp_closed(ppp); 672 err = 0; 673 break; 674 675 case PPPIOCGFLAGS: 676 val = ppp->flags | ppp->xstate | ppp->rstate; 677 if (put_user(val, p)) 678 break; 679 err = 0; 680 break; 681 682 case PPPIOCSCOMPRESS: 683 err = ppp_set_compress(ppp, arg); 684 break; 685 686 case PPPIOCGUNIT: 687 if (put_user(ppp->file.index, p)) 688 break; 689 err = 0; 690 break; 691 692 case PPPIOCSDEBUG: 693 if (get_user(val, p)) 694 break; 695 ppp->debug = val; 696 err = 0; 697 break; 698 699 case PPPIOCGDEBUG: 700 if (put_user(ppp->debug, p)) 701 break; 702 err = 0; 703 break; 704 705 case PPPIOCGIDLE: 706 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ; 707 idle.recv_idle = (jiffies - ppp->last_recv) / HZ; 708 if (copy_to_user(argp, &idle, sizeof(idle))) 709 break; 710 err = 0; 711 break; 712 713 case PPPIOCSMAXCID: 714 if (get_user(val, p)) 715 break; 716 val2 = 15; 717 if ((val >> 16) != 0) { 718 val2 = val >> 16; 719 val &= 0xffff; 720 } 721 vj = slhc_init(val2+1, val+1); 722 if (!vj) { 723 netdev_err(ppp->dev, 724 "PPP: no memory (VJ compressor)\n"); 725 err = -ENOMEM; 726 break; 727 } 728 ppp_lock(ppp); 729 if (ppp->vj) 730 slhc_free(ppp->vj); 731 ppp->vj = vj; 732 ppp_unlock(ppp); 733 err = 0; 734 break; 735 736 case PPPIOCGNPMODE: 737 case PPPIOCSNPMODE: 738 if (copy_from_user(&npi, argp, sizeof(npi))) 739 break; 740 err = proto_to_npindex(npi.protocol); 741 if (err < 0) 742 break; 743 i = err; 744 if (cmd == PPPIOCGNPMODE) { 745 err = -EFAULT; 746 npi.mode = ppp->npmode[i]; 747 if (copy_to_user(argp, &npi, sizeof(npi))) 748 break; 749 } else { 750 ppp->npmode[i] = npi.mode; 751 /* we may be able to transmit more packets now (??) */ 752 netif_wake_queue(ppp->dev); 753 } 754 err = 0; 755 break; 756 757 #ifdef CONFIG_PPP_FILTER 758 case PPPIOCSPASS: 759 { 760 struct sock_filter *code; 761 762 err = get_filter(argp, &code); 763 if (err >= 0) { 764 struct bpf_prog *pass_filter = NULL; 765 struct sock_fprog_kern fprog = { 766 .len = err, 767 .filter = code, 768 }; 769 770 err = 0; 771 if (fprog.filter) 772 err = bpf_prog_create(&pass_filter, &fprog); 773 if (!err) { 774 ppp_lock(ppp); 775 if (ppp->pass_filter) 776 bpf_prog_destroy(ppp->pass_filter); 777 ppp->pass_filter = pass_filter; 778 ppp_unlock(ppp); 779 } 780 kfree(code); 781 } 782 break; 783 } 784 case PPPIOCSACTIVE: 785 { 786 struct sock_filter *code; 787 788 err = get_filter(argp, &code); 789 if (err >= 0) { 790 struct bpf_prog *active_filter = NULL; 791 struct sock_fprog_kern fprog = { 792 .len = err, 793 .filter = code, 794 }; 795 796 err = 0; 797 if (fprog.filter) 798 err = bpf_prog_create(&active_filter, &fprog); 799 if (!err) { 800 ppp_lock(ppp); 801 if (ppp->active_filter) 802 bpf_prog_destroy(ppp->active_filter); 803 ppp->active_filter = active_filter; 804 ppp_unlock(ppp); 805 } 806 kfree(code); 807 } 808 break; 809 } 810 #endif /* CONFIG_PPP_FILTER */ 811 812 #ifdef CONFIG_PPP_MULTILINK 813 case PPPIOCSMRRU: 814 if (get_user(val, p)) 815 break; 816 ppp_recv_lock(ppp); 817 ppp->mrru = val; 818 ppp_recv_unlock(ppp); 819 err = 0; 820 break; 821 #endif /* CONFIG_PPP_MULTILINK */ 822 823 default: 824 err = -ENOTTY; 825 } 826 mutex_unlock(&ppp_mutex); 827 return err; 828 } 829 830 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 831 struct file *file, unsigned int cmd, unsigned long arg) 832 { 833 int unit, err = -EFAULT; 834 struct ppp *ppp; 835 struct channel *chan; 836 struct ppp_net *pn; 837 int __user *p = (int __user *)arg; 838 839 mutex_lock(&ppp_mutex); 840 switch (cmd) { 841 case PPPIOCNEWUNIT: 842 /* Create a new ppp unit */ 843 if (get_user(unit, p)) 844 break; 845 ppp = ppp_create_interface(net, unit, file, &err); 846 if (!ppp) 847 break; 848 file->private_data = &ppp->file; 849 err = -EFAULT; 850 if (put_user(ppp->file.index, p)) 851 break; 852 err = 0; 853 break; 854 855 case PPPIOCATTACH: 856 /* Attach to an existing ppp unit */ 857 if (get_user(unit, p)) 858 break; 859 err = -ENXIO; 860 pn = ppp_pernet(net); 861 mutex_lock(&pn->all_ppp_mutex); 862 ppp = ppp_find_unit(pn, unit); 863 if (ppp) { 864 atomic_inc(&ppp->file.refcnt); 865 file->private_data = &ppp->file; 866 err = 0; 867 } 868 mutex_unlock(&pn->all_ppp_mutex); 869 break; 870 871 case PPPIOCATTCHAN: 872 if (get_user(unit, p)) 873 break; 874 err = -ENXIO; 875 pn = ppp_pernet(net); 876 spin_lock_bh(&pn->all_channels_lock); 877 chan = ppp_find_channel(pn, unit); 878 if (chan) { 879 atomic_inc(&chan->file.refcnt); 880 file->private_data = &chan->file; 881 err = 0; 882 } 883 spin_unlock_bh(&pn->all_channels_lock); 884 break; 885 886 default: 887 err = -ENOTTY; 888 } 889 mutex_unlock(&ppp_mutex); 890 return err; 891 } 892 893 static const struct file_operations ppp_device_fops = { 894 .owner = THIS_MODULE, 895 .read = ppp_read, 896 .write = ppp_write, 897 .poll = ppp_poll, 898 .unlocked_ioctl = ppp_ioctl, 899 .open = ppp_open, 900 .release = ppp_release, 901 .llseek = noop_llseek, 902 }; 903 904 static __net_init int ppp_init_net(struct net *net) 905 { 906 struct ppp_net *pn = net_generic(net, ppp_net_id); 907 908 idr_init(&pn->units_idr); 909 mutex_init(&pn->all_ppp_mutex); 910 911 INIT_LIST_HEAD(&pn->all_channels); 912 INIT_LIST_HEAD(&pn->new_channels); 913 914 spin_lock_init(&pn->all_channels_lock); 915 916 return 0; 917 } 918 919 static __net_exit void ppp_exit_net(struct net *net) 920 { 921 struct ppp_net *pn = net_generic(net, ppp_net_id); 922 struct ppp *ppp; 923 LIST_HEAD(list); 924 int id; 925 926 rtnl_lock(); 927 idr_for_each_entry(&pn->units_idr, ppp, id) 928 unregister_netdevice_queue(ppp->dev, &list); 929 930 unregister_netdevice_many(&list); 931 rtnl_unlock(); 932 933 idr_destroy(&pn->units_idr); 934 } 935 936 static struct pernet_operations ppp_net_ops = { 937 .init = ppp_init_net, 938 .exit = ppp_exit_net, 939 .id = &ppp_net_id, 940 .size = sizeof(struct ppp_net), 941 }; 942 943 #define PPP_MAJOR 108 944 945 /* Called at boot time if ppp is compiled into the kernel, 946 or at module load time (from init_module) if compiled as a module. */ 947 static int __init ppp_init(void) 948 { 949 int err; 950 951 pr_info("PPP generic driver version " PPP_VERSION "\n"); 952 953 err = register_pernet_device(&ppp_net_ops); 954 if (err) { 955 pr_err("failed to register PPP pernet device (%d)\n", err); 956 goto out; 957 } 958 959 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops); 960 if (err) { 961 pr_err("failed to register PPP device (%d)\n", err); 962 goto out_net; 963 } 964 965 ppp_class = class_create(THIS_MODULE, "ppp"); 966 if (IS_ERR(ppp_class)) { 967 err = PTR_ERR(ppp_class); 968 goto out_chrdev; 969 } 970 971 /* not a big deal if we fail here :-) */ 972 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp"); 973 974 return 0; 975 976 out_chrdev: 977 unregister_chrdev(PPP_MAJOR, "ppp"); 978 out_net: 979 unregister_pernet_device(&ppp_net_ops); 980 out: 981 return err; 982 } 983 984 /* 985 * Network interface unit routines. 986 */ 987 static netdev_tx_t 988 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev) 989 { 990 struct ppp *ppp = netdev_priv(dev); 991 int npi, proto; 992 unsigned char *pp; 993 994 npi = ethertype_to_npindex(ntohs(skb->protocol)); 995 if (npi < 0) 996 goto outf; 997 998 /* Drop, accept or reject the packet */ 999 switch (ppp->npmode[npi]) { 1000 case NPMODE_PASS: 1001 break; 1002 case NPMODE_QUEUE: 1003 /* it would be nice to have a way to tell the network 1004 system to queue this one up for later. */ 1005 goto outf; 1006 case NPMODE_DROP: 1007 case NPMODE_ERROR: 1008 goto outf; 1009 } 1010 1011 /* Put the 2-byte PPP protocol number on the front, 1012 making sure there is room for the address and control fields. */ 1013 if (skb_cow_head(skb, PPP_HDRLEN)) 1014 goto outf; 1015 1016 pp = skb_push(skb, 2); 1017 proto = npindex_to_proto[npi]; 1018 put_unaligned_be16(proto, pp); 1019 1020 skb_queue_tail(&ppp->file.xq, skb); 1021 ppp_xmit_process(ppp); 1022 return NETDEV_TX_OK; 1023 1024 outf: 1025 kfree_skb(skb); 1026 ++dev->stats.tx_dropped; 1027 return NETDEV_TX_OK; 1028 } 1029 1030 static int 1031 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 1032 { 1033 struct ppp *ppp = netdev_priv(dev); 1034 int err = -EFAULT; 1035 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data; 1036 struct ppp_stats stats; 1037 struct ppp_comp_stats cstats; 1038 char *vers; 1039 1040 switch (cmd) { 1041 case SIOCGPPPSTATS: 1042 ppp_get_stats(ppp, &stats); 1043 if (copy_to_user(addr, &stats, sizeof(stats))) 1044 break; 1045 err = 0; 1046 break; 1047 1048 case SIOCGPPPCSTATS: 1049 memset(&cstats, 0, sizeof(cstats)); 1050 if (ppp->xc_state) 1051 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c); 1052 if (ppp->rc_state) 1053 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d); 1054 if (copy_to_user(addr, &cstats, sizeof(cstats))) 1055 break; 1056 err = 0; 1057 break; 1058 1059 case SIOCGPPPVER: 1060 vers = PPP_VERSION; 1061 if (copy_to_user(addr, vers, strlen(vers) + 1)) 1062 break; 1063 err = 0; 1064 break; 1065 1066 default: 1067 err = -EINVAL; 1068 } 1069 1070 return err; 1071 } 1072 1073 static struct rtnl_link_stats64* 1074 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64) 1075 { 1076 struct ppp *ppp = netdev_priv(dev); 1077 1078 ppp_recv_lock(ppp); 1079 stats64->rx_packets = ppp->stats64.rx_packets; 1080 stats64->rx_bytes = ppp->stats64.rx_bytes; 1081 ppp_recv_unlock(ppp); 1082 1083 ppp_xmit_lock(ppp); 1084 stats64->tx_packets = ppp->stats64.tx_packets; 1085 stats64->tx_bytes = ppp->stats64.tx_bytes; 1086 ppp_xmit_unlock(ppp); 1087 1088 stats64->rx_errors = dev->stats.rx_errors; 1089 stats64->tx_errors = dev->stats.tx_errors; 1090 stats64->rx_dropped = dev->stats.rx_dropped; 1091 stats64->tx_dropped = dev->stats.tx_dropped; 1092 stats64->rx_length_errors = dev->stats.rx_length_errors; 1093 1094 return stats64; 1095 } 1096 1097 static struct lock_class_key ppp_tx_busylock; 1098 static int ppp_dev_init(struct net_device *dev) 1099 { 1100 dev->qdisc_tx_busylock = &ppp_tx_busylock; 1101 return 0; 1102 } 1103 1104 static void ppp_dev_uninit(struct net_device *dev) 1105 { 1106 struct ppp *ppp = netdev_priv(dev); 1107 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 1108 1109 ppp_lock(ppp); 1110 ppp->closing = 1; 1111 ppp_unlock(ppp); 1112 1113 mutex_lock(&pn->all_ppp_mutex); 1114 unit_put(&pn->units_idr, ppp->file.index); 1115 mutex_unlock(&pn->all_ppp_mutex); 1116 1117 ppp->owner = NULL; 1118 1119 ppp->file.dead = 1; 1120 wake_up_interruptible(&ppp->file.rwait); 1121 } 1122 1123 static const struct net_device_ops ppp_netdev_ops = { 1124 .ndo_init = ppp_dev_init, 1125 .ndo_uninit = ppp_dev_uninit, 1126 .ndo_start_xmit = ppp_start_xmit, 1127 .ndo_do_ioctl = ppp_net_ioctl, 1128 .ndo_get_stats64 = ppp_get_stats64, 1129 }; 1130 1131 static void ppp_setup(struct net_device *dev) 1132 { 1133 dev->netdev_ops = &ppp_netdev_ops; 1134 dev->hard_header_len = PPP_HDRLEN; 1135 dev->mtu = PPP_MRU; 1136 dev->addr_len = 0; 1137 dev->tx_queue_len = 3; 1138 dev->type = ARPHRD_PPP; 1139 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 1140 dev->features |= NETIF_F_NETNS_LOCAL; 1141 netif_keep_dst(dev); 1142 } 1143 1144 /* 1145 * Transmit-side routines. 1146 */ 1147 1148 /* 1149 * Called to do any work queued up on the transmit side 1150 * that can now be done. 1151 */ 1152 static void 1153 ppp_xmit_process(struct ppp *ppp) 1154 { 1155 struct sk_buff *skb; 1156 1157 ppp_xmit_lock(ppp); 1158 if (!ppp->closing) { 1159 ppp_push(ppp); 1160 while (!ppp->xmit_pending && 1161 (skb = skb_dequeue(&ppp->file.xq))) 1162 ppp_send_frame(ppp, skb); 1163 /* If there's no work left to do, tell the core net 1164 code that we can accept some more. */ 1165 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq)) 1166 netif_wake_queue(ppp->dev); 1167 else 1168 netif_stop_queue(ppp->dev); 1169 } 1170 ppp_xmit_unlock(ppp); 1171 } 1172 1173 static inline struct sk_buff * 1174 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) 1175 { 1176 struct sk_buff *new_skb; 1177 int len; 1178 int new_skb_size = ppp->dev->mtu + 1179 ppp->xcomp->comp_extra + ppp->dev->hard_header_len; 1180 int compressor_skb_size = ppp->dev->mtu + 1181 ppp->xcomp->comp_extra + PPP_HDRLEN; 1182 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC); 1183 if (!new_skb) { 1184 if (net_ratelimit()) 1185 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n"); 1186 return NULL; 1187 } 1188 if (ppp->dev->hard_header_len > PPP_HDRLEN) 1189 skb_reserve(new_skb, 1190 ppp->dev->hard_header_len - PPP_HDRLEN); 1191 1192 /* compressor still expects A/C bytes in hdr */ 1193 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, 1194 new_skb->data, skb->len + 2, 1195 compressor_skb_size); 1196 if (len > 0 && (ppp->flags & SC_CCP_UP)) { 1197 consume_skb(skb); 1198 skb = new_skb; 1199 skb_put(skb, len); 1200 skb_pull(skb, 2); /* pull off A/C bytes */ 1201 } else if (len == 0) { 1202 /* didn't compress, or CCP not up yet */ 1203 consume_skb(new_skb); 1204 new_skb = skb; 1205 } else { 1206 /* 1207 * (len < 0) 1208 * MPPE requires that we do not send unencrypted 1209 * frames. The compressor will return -1 if we 1210 * should drop the frame. We cannot simply test 1211 * the compress_proto because MPPE and MPPC share 1212 * the same number. 1213 */ 1214 if (net_ratelimit()) 1215 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n"); 1216 kfree_skb(skb); 1217 consume_skb(new_skb); 1218 new_skb = NULL; 1219 } 1220 return new_skb; 1221 } 1222 1223 /* 1224 * Compress and send a frame. 1225 * The caller should have locked the xmit path, 1226 * and xmit_pending should be 0. 1227 */ 1228 static void 1229 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) 1230 { 1231 int proto = PPP_PROTO(skb); 1232 struct sk_buff *new_skb; 1233 int len; 1234 unsigned char *cp; 1235 1236 if (proto < 0x8000) { 1237 #ifdef CONFIG_PPP_FILTER 1238 /* check if we should pass this packet */ 1239 /* the filter instructions are constructed assuming 1240 a four-byte PPP header on each packet */ 1241 *skb_push(skb, 2) = 1; 1242 if (ppp->pass_filter && 1243 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 1244 if (ppp->debug & 1) 1245 netdev_printk(KERN_DEBUG, ppp->dev, 1246 "PPP: outbound frame " 1247 "not passed\n"); 1248 kfree_skb(skb); 1249 return; 1250 } 1251 /* if this packet passes the active filter, record the time */ 1252 if (!(ppp->active_filter && 1253 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 1254 ppp->last_xmit = jiffies; 1255 skb_pull(skb, 2); 1256 #else 1257 /* for data packets, record the time */ 1258 ppp->last_xmit = jiffies; 1259 #endif /* CONFIG_PPP_FILTER */ 1260 } 1261 1262 ++ppp->stats64.tx_packets; 1263 ppp->stats64.tx_bytes += skb->len - 2; 1264 1265 switch (proto) { 1266 case PPP_IP: 1267 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0) 1268 break; 1269 /* try to do VJ TCP header compression */ 1270 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2, 1271 GFP_ATOMIC); 1272 if (!new_skb) { 1273 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n"); 1274 goto drop; 1275 } 1276 skb_reserve(new_skb, ppp->dev->hard_header_len - 2); 1277 cp = skb->data + 2; 1278 len = slhc_compress(ppp->vj, cp, skb->len - 2, 1279 new_skb->data + 2, &cp, 1280 !(ppp->flags & SC_NO_TCP_CCID)); 1281 if (cp == skb->data + 2) { 1282 /* didn't compress */ 1283 consume_skb(new_skb); 1284 } else { 1285 if (cp[0] & SL_TYPE_COMPRESSED_TCP) { 1286 proto = PPP_VJC_COMP; 1287 cp[0] &= ~SL_TYPE_COMPRESSED_TCP; 1288 } else { 1289 proto = PPP_VJC_UNCOMP; 1290 cp[0] = skb->data[2]; 1291 } 1292 consume_skb(skb); 1293 skb = new_skb; 1294 cp = skb_put(skb, len + 2); 1295 cp[0] = 0; 1296 cp[1] = proto; 1297 } 1298 break; 1299 1300 case PPP_CCP: 1301 /* peek at outbound CCP frames */ 1302 ppp_ccp_peek(ppp, skb, 0); 1303 break; 1304 } 1305 1306 /* try to do packet compression */ 1307 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state && 1308 proto != PPP_LCP && proto != PPP_CCP) { 1309 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) { 1310 if (net_ratelimit()) 1311 netdev_err(ppp->dev, 1312 "ppp: compression required but " 1313 "down - pkt dropped.\n"); 1314 goto drop; 1315 } 1316 skb = pad_compress_skb(ppp, skb); 1317 if (!skb) 1318 goto drop; 1319 } 1320 1321 /* 1322 * If we are waiting for traffic (demand dialling), 1323 * queue it up for pppd to receive. 1324 */ 1325 if (ppp->flags & SC_LOOP_TRAFFIC) { 1326 if (ppp->file.rq.qlen > PPP_MAX_RQLEN) 1327 goto drop; 1328 skb_queue_tail(&ppp->file.rq, skb); 1329 wake_up_interruptible(&ppp->file.rwait); 1330 return; 1331 } 1332 1333 ppp->xmit_pending = skb; 1334 ppp_push(ppp); 1335 return; 1336 1337 drop: 1338 kfree_skb(skb); 1339 ++ppp->dev->stats.tx_errors; 1340 } 1341 1342 /* 1343 * Try to send the frame in xmit_pending. 1344 * The caller should have the xmit path locked. 1345 */ 1346 static void 1347 ppp_push(struct ppp *ppp) 1348 { 1349 struct list_head *list; 1350 struct channel *pch; 1351 struct sk_buff *skb = ppp->xmit_pending; 1352 1353 if (!skb) 1354 return; 1355 1356 list = &ppp->channels; 1357 if (list_empty(list)) { 1358 /* nowhere to send the packet, just drop it */ 1359 ppp->xmit_pending = NULL; 1360 kfree_skb(skb); 1361 return; 1362 } 1363 1364 if ((ppp->flags & SC_MULTILINK) == 0) { 1365 /* not doing multilink: send it down the first channel */ 1366 list = list->next; 1367 pch = list_entry(list, struct channel, clist); 1368 1369 spin_lock_bh(&pch->downl); 1370 if (pch->chan) { 1371 if (pch->chan->ops->start_xmit(pch->chan, skb)) 1372 ppp->xmit_pending = NULL; 1373 } else { 1374 /* channel got unregistered */ 1375 kfree_skb(skb); 1376 ppp->xmit_pending = NULL; 1377 } 1378 spin_unlock_bh(&pch->downl); 1379 return; 1380 } 1381 1382 #ifdef CONFIG_PPP_MULTILINK 1383 /* Multilink: fragment the packet over as many links 1384 as can take the packet at the moment. */ 1385 if (!ppp_mp_explode(ppp, skb)) 1386 return; 1387 #endif /* CONFIG_PPP_MULTILINK */ 1388 1389 ppp->xmit_pending = NULL; 1390 kfree_skb(skb); 1391 } 1392 1393 #ifdef CONFIG_PPP_MULTILINK 1394 static bool mp_protocol_compress __read_mostly = true; 1395 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR); 1396 MODULE_PARM_DESC(mp_protocol_compress, 1397 "compress protocol id in multilink fragments"); 1398 1399 /* 1400 * Divide a packet to be transmitted into fragments and 1401 * send them out the individual links. 1402 */ 1403 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb) 1404 { 1405 int len, totlen; 1406 int i, bits, hdrlen, mtu; 1407 int flen; 1408 int navail, nfree, nzero; 1409 int nbigger; 1410 int totspeed; 1411 int totfree; 1412 unsigned char *p, *q; 1413 struct list_head *list; 1414 struct channel *pch; 1415 struct sk_buff *frag; 1416 struct ppp_channel *chan; 1417 1418 totspeed = 0; /*total bitrate of the bundle*/ 1419 nfree = 0; /* # channels which have no packet already queued */ 1420 navail = 0; /* total # of usable channels (not deregistered) */ 1421 nzero = 0; /* number of channels with zero speed associated*/ 1422 totfree = 0; /*total # of channels available and 1423 *having no queued packets before 1424 *starting the fragmentation*/ 1425 1426 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1427 i = 0; 1428 list_for_each_entry(pch, &ppp->channels, clist) { 1429 if (pch->chan) { 1430 pch->avail = 1; 1431 navail++; 1432 pch->speed = pch->chan->speed; 1433 } else { 1434 pch->avail = 0; 1435 } 1436 if (pch->avail) { 1437 if (skb_queue_empty(&pch->file.xq) || 1438 !pch->had_frag) { 1439 if (pch->speed == 0) 1440 nzero++; 1441 else 1442 totspeed += pch->speed; 1443 1444 pch->avail = 2; 1445 ++nfree; 1446 ++totfree; 1447 } 1448 if (!pch->had_frag && i < ppp->nxchan) 1449 ppp->nxchan = i; 1450 } 1451 ++i; 1452 } 1453 /* 1454 * Don't start sending this packet unless at least half of 1455 * the channels are free. This gives much better TCP 1456 * performance if we have a lot of channels. 1457 */ 1458 if (nfree == 0 || nfree < navail / 2) 1459 return 0; /* can't take now, leave it in xmit_pending */ 1460 1461 /* Do protocol field compression */ 1462 p = skb->data; 1463 len = skb->len; 1464 if (*p == 0 && mp_protocol_compress) { 1465 ++p; 1466 --len; 1467 } 1468 1469 totlen = len; 1470 nbigger = len % nfree; 1471 1472 /* skip to the channel after the one we last used 1473 and start at that one */ 1474 list = &ppp->channels; 1475 for (i = 0; i < ppp->nxchan; ++i) { 1476 list = list->next; 1477 if (list == &ppp->channels) { 1478 i = 0; 1479 break; 1480 } 1481 } 1482 1483 /* create a fragment for each channel */ 1484 bits = B; 1485 while (len > 0) { 1486 list = list->next; 1487 if (list == &ppp->channels) { 1488 i = 0; 1489 continue; 1490 } 1491 pch = list_entry(list, struct channel, clist); 1492 ++i; 1493 if (!pch->avail) 1494 continue; 1495 1496 /* 1497 * Skip this channel if it has a fragment pending already and 1498 * we haven't given a fragment to all of the free channels. 1499 */ 1500 if (pch->avail == 1) { 1501 if (nfree > 0) 1502 continue; 1503 } else { 1504 pch->avail = 1; 1505 } 1506 1507 /* check the channel's mtu and whether it is still attached. */ 1508 spin_lock_bh(&pch->downl); 1509 if (pch->chan == NULL) { 1510 /* can't use this channel, it's being deregistered */ 1511 if (pch->speed == 0) 1512 nzero--; 1513 else 1514 totspeed -= pch->speed; 1515 1516 spin_unlock_bh(&pch->downl); 1517 pch->avail = 0; 1518 totlen = len; 1519 totfree--; 1520 nfree--; 1521 if (--navail == 0) 1522 break; 1523 continue; 1524 } 1525 1526 /* 1527 *if the channel speed is not set divide 1528 *the packet evenly among the free channels; 1529 *otherwise divide it according to the speed 1530 *of the channel we are going to transmit on 1531 */ 1532 flen = len; 1533 if (nfree > 0) { 1534 if (pch->speed == 0) { 1535 flen = len/nfree; 1536 if (nbigger > 0) { 1537 flen++; 1538 nbigger--; 1539 } 1540 } else { 1541 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) / 1542 ((totspeed*totfree)/pch->speed)) - hdrlen; 1543 if (nbigger > 0) { 1544 flen += ((totfree - nzero)*pch->speed)/totspeed; 1545 nbigger -= ((totfree - nzero)*pch->speed)/ 1546 totspeed; 1547 } 1548 } 1549 nfree--; 1550 } 1551 1552 /* 1553 *check if we are on the last channel or 1554 *we exceded the length of the data to 1555 *fragment 1556 */ 1557 if ((nfree <= 0) || (flen > len)) 1558 flen = len; 1559 /* 1560 *it is not worth to tx on slow channels: 1561 *in that case from the resulting flen according to the 1562 *above formula will be equal or less than zero. 1563 *Skip the channel in this case 1564 */ 1565 if (flen <= 0) { 1566 pch->avail = 2; 1567 spin_unlock_bh(&pch->downl); 1568 continue; 1569 } 1570 1571 /* 1572 * hdrlen includes the 2-byte PPP protocol field, but the 1573 * MTU counts only the payload excluding the protocol field. 1574 * (RFC1661 Section 2) 1575 */ 1576 mtu = pch->chan->mtu - (hdrlen - 2); 1577 if (mtu < 4) 1578 mtu = 4; 1579 if (flen > mtu) 1580 flen = mtu; 1581 if (flen == len) 1582 bits |= E; 1583 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC); 1584 if (!frag) 1585 goto noskb; 1586 q = skb_put(frag, flen + hdrlen); 1587 1588 /* make the MP header */ 1589 put_unaligned_be16(PPP_MP, q); 1590 if (ppp->flags & SC_MP_XSHORTSEQ) { 1591 q[2] = bits + ((ppp->nxseq >> 8) & 0xf); 1592 q[3] = ppp->nxseq; 1593 } else { 1594 q[2] = bits; 1595 q[3] = ppp->nxseq >> 16; 1596 q[4] = ppp->nxseq >> 8; 1597 q[5] = ppp->nxseq; 1598 } 1599 1600 memcpy(q + hdrlen, p, flen); 1601 1602 /* try to send it down the channel */ 1603 chan = pch->chan; 1604 if (!skb_queue_empty(&pch->file.xq) || 1605 !chan->ops->start_xmit(chan, frag)) 1606 skb_queue_tail(&pch->file.xq, frag); 1607 pch->had_frag = 1; 1608 p += flen; 1609 len -= flen; 1610 ++ppp->nxseq; 1611 bits = 0; 1612 spin_unlock_bh(&pch->downl); 1613 } 1614 ppp->nxchan = i; 1615 1616 return 1; 1617 1618 noskb: 1619 spin_unlock_bh(&pch->downl); 1620 if (ppp->debug & 1) 1621 netdev_err(ppp->dev, "PPP: no memory (fragment)\n"); 1622 ++ppp->dev->stats.tx_errors; 1623 ++ppp->nxseq; 1624 return 1; /* abandon the frame */ 1625 } 1626 #endif /* CONFIG_PPP_MULTILINK */ 1627 1628 /* 1629 * Try to send data out on a channel. 1630 */ 1631 static void 1632 ppp_channel_push(struct channel *pch) 1633 { 1634 struct sk_buff *skb; 1635 struct ppp *ppp; 1636 1637 spin_lock_bh(&pch->downl); 1638 if (pch->chan) { 1639 while (!skb_queue_empty(&pch->file.xq)) { 1640 skb = skb_dequeue(&pch->file.xq); 1641 if (!pch->chan->ops->start_xmit(pch->chan, skb)) { 1642 /* put the packet back and try again later */ 1643 skb_queue_head(&pch->file.xq, skb); 1644 break; 1645 } 1646 } 1647 } else { 1648 /* channel got deregistered */ 1649 skb_queue_purge(&pch->file.xq); 1650 } 1651 spin_unlock_bh(&pch->downl); 1652 /* see if there is anything from the attached unit to be sent */ 1653 if (skb_queue_empty(&pch->file.xq)) { 1654 read_lock_bh(&pch->upl); 1655 ppp = pch->ppp; 1656 if (ppp) 1657 ppp_xmit_process(ppp); 1658 read_unlock_bh(&pch->upl); 1659 } 1660 } 1661 1662 /* 1663 * Receive-side routines. 1664 */ 1665 1666 struct ppp_mp_skb_parm { 1667 u32 sequence; 1668 u8 BEbits; 1669 }; 1670 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb)) 1671 1672 static inline void 1673 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1674 { 1675 ppp_recv_lock(ppp); 1676 if (!ppp->closing) 1677 ppp_receive_frame(ppp, skb, pch); 1678 else 1679 kfree_skb(skb); 1680 ppp_recv_unlock(ppp); 1681 } 1682 1683 void 1684 ppp_input(struct ppp_channel *chan, struct sk_buff *skb) 1685 { 1686 struct channel *pch = chan->ppp; 1687 int proto; 1688 1689 if (!pch) { 1690 kfree_skb(skb); 1691 return; 1692 } 1693 1694 read_lock_bh(&pch->upl); 1695 if (!pskb_may_pull(skb, 2)) { 1696 kfree_skb(skb); 1697 if (pch->ppp) { 1698 ++pch->ppp->dev->stats.rx_length_errors; 1699 ppp_receive_error(pch->ppp); 1700 } 1701 goto done; 1702 } 1703 1704 proto = PPP_PROTO(skb); 1705 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) { 1706 /* put it on the channel queue */ 1707 skb_queue_tail(&pch->file.rq, skb); 1708 /* drop old frames if queue too long */ 1709 while (pch->file.rq.qlen > PPP_MAX_RQLEN && 1710 (skb = skb_dequeue(&pch->file.rq))) 1711 kfree_skb(skb); 1712 wake_up_interruptible(&pch->file.rwait); 1713 } else { 1714 ppp_do_recv(pch->ppp, skb, pch); 1715 } 1716 1717 done: 1718 read_unlock_bh(&pch->upl); 1719 } 1720 1721 /* Put a 0-length skb in the receive queue as an error indication */ 1722 void 1723 ppp_input_error(struct ppp_channel *chan, int code) 1724 { 1725 struct channel *pch = chan->ppp; 1726 struct sk_buff *skb; 1727 1728 if (!pch) 1729 return; 1730 1731 read_lock_bh(&pch->upl); 1732 if (pch->ppp) { 1733 skb = alloc_skb(0, GFP_ATOMIC); 1734 if (skb) { 1735 skb->len = 0; /* probably unnecessary */ 1736 skb->cb[0] = code; 1737 ppp_do_recv(pch->ppp, skb, pch); 1738 } 1739 } 1740 read_unlock_bh(&pch->upl); 1741 } 1742 1743 /* 1744 * We come in here to process a received frame. 1745 * The receive side of the ppp unit is locked. 1746 */ 1747 static void 1748 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1749 { 1750 /* note: a 0-length skb is used as an error indication */ 1751 if (skb->len > 0) { 1752 skb_checksum_complete_unset(skb); 1753 #ifdef CONFIG_PPP_MULTILINK 1754 /* XXX do channel-level decompression here */ 1755 if (PPP_PROTO(skb) == PPP_MP) 1756 ppp_receive_mp_frame(ppp, skb, pch); 1757 else 1758 #endif /* CONFIG_PPP_MULTILINK */ 1759 ppp_receive_nonmp_frame(ppp, skb); 1760 } else { 1761 kfree_skb(skb); 1762 ppp_receive_error(ppp); 1763 } 1764 } 1765 1766 static void 1767 ppp_receive_error(struct ppp *ppp) 1768 { 1769 ++ppp->dev->stats.rx_errors; 1770 if (ppp->vj) 1771 slhc_toss(ppp->vj); 1772 } 1773 1774 static void 1775 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) 1776 { 1777 struct sk_buff *ns; 1778 int proto, len, npi; 1779 1780 /* 1781 * Decompress the frame, if compressed. 1782 * Note that some decompressors need to see uncompressed frames 1783 * that come in as well as compressed frames. 1784 */ 1785 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) && 1786 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0) 1787 skb = ppp_decompress_frame(ppp, skb); 1788 1789 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR) 1790 goto err; 1791 1792 proto = PPP_PROTO(skb); 1793 switch (proto) { 1794 case PPP_VJC_COMP: 1795 /* decompress VJ compressed packets */ 1796 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 1797 goto err; 1798 1799 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) { 1800 /* copy to a new sk_buff with more tailroom */ 1801 ns = dev_alloc_skb(skb->len + 128); 1802 if (!ns) { 1803 netdev_err(ppp->dev, "PPP: no memory " 1804 "(VJ decomp)\n"); 1805 goto err; 1806 } 1807 skb_reserve(ns, 2); 1808 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len); 1809 consume_skb(skb); 1810 skb = ns; 1811 } 1812 else 1813 skb->ip_summed = CHECKSUM_NONE; 1814 1815 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2); 1816 if (len <= 0) { 1817 netdev_printk(KERN_DEBUG, ppp->dev, 1818 "PPP: VJ decompression error\n"); 1819 goto err; 1820 } 1821 len += 2; 1822 if (len > skb->len) 1823 skb_put(skb, len - skb->len); 1824 else if (len < skb->len) 1825 skb_trim(skb, len); 1826 proto = PPP_IP; 1827 break; 1828 1829 case PPP_VJC_UNCOMP: 1830 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 1831 goto err; 1832 1833 /* Until we fix the decompressor need to make sure 1834 * data portion is linear. 1835 */ 1836 if (!pskb_may_pull(skb, skb->len)) 1837 goto err; 1838 1839 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) { 1840 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n"); 1841 goto err; 1842 } 1843 proto = PPP_IP; 1844 break; 1845 1846 case PPP_CCP: 1847 ppp_ccp_peek(ppp, skb, 1); 1848 break; 1849 } 1850 1851 ++ppp->stats64.rx_packets; 1852 ppp->stats64.rx_bytes += skb->len - 2; 1853 1854 npi = proto_to_npindex(proto); 1855 if (npi < 0) { 1856 /* control or unknown frame - pass it to pppd */ 1857 skb_queue_tail(&ppp->file.rq, skb); 1858 /* limit queue length by dropping old frames */ 1859 while (ppp->file.rq.qlen > PPP_MAX_RQLEN && 1860 (skb = skb_dequeue(&ppp->file.rq))) 1861 kfree_skb(skb); 1862 /* wake up any process polling or blocking on read */ 1863 wake_up_interruptible(&ppp->file.rwait); 1864 1865 } else { 1866 /* network protocol frame - give it to the kernel */ 1867 1868 #ifdef CONFIG_PPP_FILTER 1869 /* check if the packet passes the pass and active filters */ 1870 /* the filter instructions are constructed assuming 1871 a four-byte PPP header on each packet */ 1872 if (ppp->pass_filter || ppp->active_filter) { 1873 if (skb_unclone(skb, GFP_ATOMIC)) 1874 goto err; 1875 1876 *skb_push(skb, 2) = 0; 1877 if (ppp->pass_filter && 1878 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 1879 if (ppp->debug & 1) 1880 netdev_printk(KERN_DEBUG, ppp->dev, 1881 "PPP: inbound frame " 1882 "not passed\n"); 1883 kfree_skb(skb); 1884 return; 1885 } 1886 if (!(ppp->active_filter && 1887 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 1888 ppp->last_recv = jiffies; 1889 __skb_pull(skb, 2); 1890 } else 1891 #endif /* CONFIG_PPP_FILTER */ 1892 ppp->last_recv = jiffies; 1893 1894 if ((ppp->dev->flags & IFF_UP) == 0 || 1895 ppp->npmode[npi] != NPMODE_PASS) { 1896 kfree_skb(skb); 1897 } else { 1898 /* chop off protocol */ 1899 skb_pull_rcsum(skb, 2); 1900 skb->dev = ppp->dev; 1901 skb->protocol = htons(npindex_to_ethertype[npi]); 1902 skb_reset_mac_header(skb); 1903 netif_rx(skb); 1904 } 1905 } 1906 return; 1907 1908 err: 1909 kfree_skb(skb); 1910 ppp_receive_error(ppp); 1911 } 1912 1913 static struct sk_buff * 1914 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb) 1915 { 1916 int proto = PPP_PROTO(skb); 1917 struct sk_buff *ns; 1918 int len; 1919 1920 /* Until we fix all the decompressor's need to make sure 1921 * data portion is linear. 1922 */ 1923 if (!pskb_may_pull(skb, skb->len)) 1924 goto err; 1925 1926 if (proto == PPP_COMP) { 1927 int obuff_size; 1928 1929 switch(ppp->rcomp->compress_proto) { 1930 case CI_MPPE: 1931 obuff_size = ppp->mru + PPP_HDRLEN + 1; 1932 break; 1933 default: 1934 obuff_size = ppp->mru + PPP_HDRLEN; 1935 break; 1936 } 1937 1938 ns = dev_alloc_skb(obuff_size); 1939 if (!ns) { 1940 netdev_err(ppp->dev, "ppp_decompress_frame: " 1941 "no memory\n"); 1942 goto err; 1943 } 1944 /* the decompressor still expects the A/C bytes in the hdr */ 1945 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2, 1946 skb->len + 2, ns->data, obuff_size); 1947 if (len < 0) { 1948 /* Pass the compressed frame to pppd as an 1949 error indication. */ 1950 if (len == DECOMP_FATALERROR) 1951 ppp->rstate |= SC_DC_FERROR; 1952 kfree_skb(ns); 1953 goto err; 1954 } 1955 1956 consume_skb(skb); 1957 skb = ns; 1958 skb_put(skb, len); 1959 skb_pull(skb, 2); /* pull off the A/C bytes */ 1960 1961 } else { 1962 /* Uncompressed frame - pass to decompressor so it 1963 can update its dictionary if necessary. */ 1964 if (ppp->rcomp->incomp) 1965 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2, 1966 skb->len + 2); 1967 } 1968 1969 return skb; 1970 1971 err: 1972 ppp->rstate |= SC_DC_ERROR; 1973 ppp_receive_error(ppp); 1974 return skb; 1975 } 1976 1977 #ifdef CONFIG_PPP_MULTILINK 1978 /* 1979 * Receive a multilink frame. 1980 * We put it on the reconstruction queue and then pull off 1981 * as many completed frames as we can. 1982 */ 1983 static void 1984 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1985 { 1986 u32 mask, seq; 1987 struct channel *ch; 1988 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1989 1990 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0) 1991 goto err; /* no good, throw it away */ 1992 1993 /* Decode sequence number and begin/end bits */ 1994 if (ppp->flags & SC_MP_SHORTSEQ) { 1995 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3]; 1996 mask = 0xfff; 1997 } else { 1998 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5]; 1999 mask = 0xffffff; 2000 } 2001 PPP_MP_CB(skb)->BEbits = skb->data[2]; 2002 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */ 2003 2004 /* 2005 * Do protocol ID decompression on the first fragment of each packet. 2006 */ 2007 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1)) 2008 *skb_push(skb, 1) = 0; 2009 2010 /* 2011 * Expand sequence number to 32 bits, making it as close 2012 * as possible to ppp->minseq. 2013 */ 2014 seq |= ppp->minseq & ~mask; 2015 if ((int)(ppp->minseq - seq) > (int)(mask >> 1)) 2016 seq += mask + 1; 2017 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1)) 2018 seq -= mask + 1; /* should never happen */ 2019 PPP_MP_CB(skb)->sequence = seq; 2020 pch->lastseq = seq; 2021 2022 /* 2023 * If this packet comes before the next one we were expecting, 2024 * drop it. 2025 */ 2026 if (seq_before(seq, ppp->nextseq)) { 2027 kfree_skb(skb); 2028 ++ppp->dev->stats.rx_dropped; 2029 ppp_receive_error(ppp); 2030 return; 2031 } 2032 2033 /* 2034 * Reevaluate minseq, the minimum over all channels of the 2035 * last sequence number received on each channel. Because of 2036 * the increasing sequence number rule, we know that any fragment 2037 * before `minseq' which hasn't arrived is never going to arrive. 2038 * The list of channels can't change because we have the receive 2039 * side of the ppp unit locked. 2040 */ 2041 list_for_each_entry(ch, &ppp->channels, clist) { 2042 if (seq_before(ch->lastseq, seq)) 2043 seq = ch->lastseq; 2044 } 2045 if (seq_before(ppp->minseq, seq)) 2046 ppp->minseq = seq; 2047 2048 /* Put the fragment on the reconstruction queue */ 2049 ppp_mp_insert(ppp, skb); 2050 2051 /* If the queue is getting long, don't wait any longer for packets 2052 before the start of the queue. */ 2053 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) { 2054 struct sk_buff *mskb = skb_peek(&ppp->mrq); 2055 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence)) 2056 ppp->minseq = PPP_MP_CB(mskb)->sequence; 2057 } 2058 2059 /* Pull completed packets off the queue and receive them. */ 2060 while ((skb = ppp_mp_reconstruct(ppp))) { 2061 if (pskb_may_pull(skb, 2)) 2062 ppp_receive_nonmp_frame(ppp, skb); 2063 else { 2064 ++ppp->dev->stats.rx_length_errors; 2065 kfree_skb(skb); 2066 ppp_receive_error(ppp); 2067 } 2068 } 2069 2070 return; 2071 2072 err: 2073 kfree_skb(skb); 2074 ppp_receive_error(ppp); 2075 } 2076 2077 /* 2078 * Insert a fragment on the MP reconstruction queue. 2079 * The queue is ordered by increasing sequence number. 2080 */ 2081 static void 2082 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb) 2083 { 2084 struct sk_buff *p; 2085 struct sk_buff_head *list = &ppp->mrq; 2086 u32 seq = PPP_MP_CB(skb)->sequence; 2087 2088 /* N.B. we don't need to lock the list lock because we have the 2089 ppp unit receive-side lock. */ 2090 skb_queue_walk(list, p) { 2091 if (seq_before(seq, PPP_MP_CB(p)->sequence)) 2092 break; 2093 } 2094 __skb_queue_before(list, p, skb); 2095 } 2096 2097 /* 2098 * Reconstruct a packet from the MP fragment queue. 2099 * We go through increasing sequence numbers until we find a 2100 * complete packet, or we get to the sequence number for a fragment 2101 * which hasn't arrived but might still do so. 2102 */ 2103 static struct sk_buff * 2104 ppp_mp_reconstruct(struct ppp *ppp) 2105 { 2106 u32 seq = ppp->nextseq; 2107 u32 minseq = ppp->minseq; 2108 struct sk_buff_head *list = &ppp->mrq; 2109 struct sk_buff *p, *tmp; 2110 struct sk_buff *head, *tail; 2111 struct sk_buff *skb = NULL; 2112 int lost = 0, len = 0; 2113 2114 if (ppp->mrru == 0) /* do nothing until mrru is set */ 2115 return NULL; 2116 head = list->next; 2117 tail = NULL; 2118 skb_queue_walk_safe(list, p, tmp) { 2119 again: 2120 if (seq_before(PPP_MP_CB(p)->sequence, seq)) { 2121 /* this can't happen, anyway ignore the skb */ 2122 netdev_err(ppp->dev, "ppp_mp_reconstruct bad " 2123 "seq %u < %u\n", 2124 PPP_MP_CB(p)->sequence, seq); 2125 __skb_unlink(p, list); 2126 kfree_skb(p); 2127 continue; 2128 } 2129 if (PPP_MP_CB(p)->sequence != seq) { 2130 u32 oldseq; 2131 /* Fragment `seq' is missing. If it is after 2132 minseq, it might arrive later, so stop here. */ 2133 if (seq_after(seq, minseq)) 2134 break; 2135 /* Fragment `seq' is lost, keep going. */ 2136 lost = 1; 2137 oldseq = seq; 2138 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)? 2139 minseq + 1: PPP_MP_CB(p)->sequence; 2140 2141 if (ppp->debug & 1) 2142 netdev_printk(KERN_DEBUG, ppp->dev, 2143 "lost frag %u..%u\n", 2144 oldseq, seq-1); 2145 2146 goto again; 2147 } 2148 2149 /* 2150 * At this point we know that all the fragments from 2151 * ppp->nextseq to seq are either present or lost. 2152 * Also, there are no complete packets in the queue 2153 * that have no missing fragments and end before this 2154 * fragment. 2155 */ 2156 2157 /* B bit set indicates this fragment starts a packet */ 2158 if (PPP_MP_CB(p)->BEbits & B) { 2159 head = p; 2160 lost = 0; 2161 len = 0; 2162 } 2163 2164 len += p->len; 2165 2166 /* Got a complete packet yet? */ 2167 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) && 2168 (PPP_MP_CB(head)->BEbits & B)) { 2169 if (len > ppp->mrru + 2) { 2170 ++ppp->dev->stats.rx_length_errors; 2171 netdev_printk(KERN_DEBUG, ppp->dev, 2172 "PPP: reconstructed packet" 2173 " is too long (%d)\n", len); 2174 } else { 2175 tail = p; 2176 break; 2177 } 2178 ppp->nextseq = seq + 1; 2179 } 2180 2181 /* 2182 * If this is the ending fragment of a packet, 2183 * and we haven't found a complete valid packet yet, 2184 * we can discard up to and including this fragment. 2185 */ 2186 if (PPP_MP_CB(p)->BEbits & E) { 2187 struct sk_buff *tmp2; 2188 2189 skb_queue_reverse_walk_from_safe(list, p, tmp2) { 2190 if (ppp->debug & 1) 2191 netdev_printk(KERN_DEBUG, ppp->dev, 2192 "discarding frag %u\n", 2193 PPP_MP_CB(p)->sequence); 2194 __skb_unlink(p, list); 2195 kfree_skb(p); 2196 } 2197 head = skb_peek(list); 2198 if (!head) 2199 break; 2200 } 2201 ++seq; 2202 } 2203 2204 /* If we have a complete packet, copy it all into one skb. */ 2205 if (tail != NULL) { 2206 /* If we have discarded any fragments, 2207 signal a receive error. */ 2208 if (PPP_MP_CB(head)->sequence != ppp->nextseq) { 2209 skb_queue_walk_safe(list, p, tmp) { 2210 if (p == head) 2211 break; 2212 if (ppp->debug & 1) 2213 netdev_printk(KERN_DEBUG, ppp->dev, 2214 "discarding frag %u\n", 2215 PPP_MP_CB(p)->sequence); 2216 __skb_unlink(p, list); 2217 kfree_skb(p); 2218 } 2219 2220 if (ppp->debug & 1) 2221 netdev_printk(KERN_DEBUG, ppp->dev, 2222 " missed pkts %u..%u\n", 2223 ppp->nextseq, 2224 PPP_MP_CB(head)->sequence-1); 2225 ++ppp->dev->stats.rx_dropped; 2226 ppp_receive_error(ppp); 2227 } 2228 2229 skb = head; 2230 if (head != tail) { 2231 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list; 2232 p = skb_queue_next(list, head); 2233 __skb_unlink(skb, list); 2234 skb_queue_walk_from_safe(list, p, tmp) { 2235 __skb_unlink(p, list); 2236 *fragpp = p; 2237 p->next = NULL; 2238 fragpp = &p->next; 2239 2240 skb->len += p->len; 2241 skb->data_len += p->len; 2242 skb->truesize += p->truesize; 2243 2244 if (p == tail) 2245 break; 2246 } 2247 } else { 2248 __skb_unlink(skb, list); 2249 } 2250 2251 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1; 2252 } 2253 2254 return skb; 2255 } 2256 #endif /* CONFIG_PPP_MULTILINK */ 2257 2258 /* 2259 * Channel interface. 2260 */ 2261 2262 /* Create a new, unattached ppp channel. */ 2263 int ppp_register_channel(struct ppp_channel *chan) 2264 { 2265 return ppp_register_net_channel(current->nsproxy->net_ns, chan); 2266 } 2267 2268 /* Create a new, unattached ppp channel for specified net. */ 2269 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan) 2270 { 2271 struct channel *pch; 2272 struct ppp_net *pn; 2273 2274 pch = kzalloc(sizeof(struct channel), GFP_KERNEL); 2275 if (!pch) 2276 return -ENOMEM; 2277 2278 pn = ppp_pernet(net); 2279 2280 pch->ppp = NULL; 2281 pch->chan = chan; 2282 pch->chan_net = net; 2283 chan->ppp = pch; 2284 init_ppp_file(&pch->file, CHANNEL); 2285 pch->file.hdrlen = chan->hdrlen; 2286 #ifdef CONFIG_PPP_MULTILINK 2287 pch->lastseq = -1; 2288 #endif /* CONFIG_PPP_MULTILINK */ 2289 init_rwsem(&pch->chan_sem); 2290 spin_lock_init(&pch->downl); 2291 rwlock_init(&pch->upl); 2292 2293 spin_lock_bh(&pn->all_channels_lock); 2294 pch->file.index = ++pn->last_channel_index; 2295 list_add(&pch->list, &pn->new_channels); 2296 atomic_inc(&channel_count); 2297 spin_unlock_bh(&pn->all_channels_lock); 2298 2299 return 0; 2300 } 2301 2302 /* 2303 * Return the index of a channel. 2304 */ 2305 int ppp_channel_index(struct ppp_channel *chan) 2306 { 2307 struct channel *pch = chan->ppp; 2308 2309 if (pch) 2310 return pch->file.index; 2311 return -1; 2312 } 2313 2314 /* 2315 * Return the PPP unit number to which a channel is connected. 2316 */ 2317 int ppp_unit_number(struct ppp_channel *chan) 2318 { 2319 struct channel *pch = chan->ppp; 2320 int unit = -1; 2321 2322 if (pch) { 2323 read_lock_bh(&pch->upl); 2324 if (pch->ppp) 2325 unit = pch->ppp->file.index; 2326 read_unlock_bh(&pch->upl); 2327 } 2328 return unit; 2329 } 2330 2331 /* 2332 * Return the PPP device interface name of a channel. 2333 */ 2334 char *ppp_dev_name(struct ppp_channel *chan) 2335 { 2336 struct channel *pch = chan->ppp; 2337 char *name = NULL; 2338 2339 if (pch) { 2340 read_lock_bh(&pch->upl); 2341 if (pch->ppp && pch->ppp->dev) 2342 name = pch->ppp->dev->name; 2343 read_unlock_bh(&pch->upl); 2344 } 2345 return name; 2346 } 2347 2348 2349 /* 2350 * Disconnect a channel from the generic layer. 2351 * This must be called in process context. 2352 */ 2353 void 2354 ppp_unregister_channel(struct ppp_channel *chan) 2355 { 2356 struct channel *pch = chan->ppp; 2357 struct ppp_net *pn; 2358 2359 if (!pch) 2360 return; /* should never happen */ 2361 2362 chan->ppp = NULL; 2363 2364 /* 2365 * This ensures that we have returned from any calls into the 2366 * the channel's start_xmit or ioctl routine before we proceed. 2367 */ 2368 down_write(&pch->chan_sem); 2369 spin_lock_bh(&pch->downl); 2370 pch->chan = NULL; 2371 spin_unlock_bh(&pch->downl); 2372 up_write(&pch->chan_sem); 2373 ppp_disconnect_channel(pch); 2374 2375 pn = ppp_pernet(pch->chan_net); 2376 spin_lock_bh(&pn->all_channels_lock); 2377 list_del(&pch->list); 2378 spin_unlock_bh(&pn->all_channels_lock); 2379 2380 pch->file.dead = 1; 2381 wake_up_interruptible(&pch->file.rwait); 2382 if (atomic_dec_and_test(&pch->file.refcnt)) 2383 ppp_destroy_channel(pch); 2384 } 2385 2386 /* 2387 * Callback from a channel when it can accept more to transmit. 2388 * This should be called at BH/softirq level, not interrupt level. 2389 */ 2390 void 2391 ppp_output_wakeup(struct ppp_channel *chan) 2392 { 2393 struct channel *pch = chan->ppp; 2394 2395 if (!pch) 2396 return; 2397 ppp_channel_push(pch); 2398 } 2399 2400 /* 2401 * Compression control. 2402 */ 2403 2404 /* Process the PPPIOCSCOMPRESS ioctl. */ 2405 static int 2406 ppp_set_compress(struct ppp *ppp, unsigned long arg) 2407 { 2408 int err; 2409 struct compressor *cp, *ocomp; 2410 struct ppp_option_data data; 2411 void *state, *ostate; 2412 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH]; 2413 2414 err = -EFAULT; 2415 if (copy_from_user(&data, (void __user *) arg, sizeof(data)) || 2416 (data.length <= CCP_MAX_OPTION_LENGTH && 2417 copy_from_user(ccp_option, (void __user *) data.ptr, data.length))) 2418 goto out; 2419 err = -EINVAL; 2420 if (data.length > CCP_MAX_OPTION_LENGTH || 2421 ccp_option[1] < 2 || ccp_option[1] > data.length) 2422 goto out; 2423 2424 cp = try_then_request_module( 2425 find_compressor(ccp_option[0]), 2426 "ppp-compress-%d", ccp_option[0]); 2427 if (!cp) 2428 goto out; 2429 2430 err = -ENOBUFS; 2431 if (data.transmit) { 2432 state = cp->comp_alloc(ccp_option, data.length); 2433 if (state) { 2434 ppp_xmit_lock(ppp); 2435 ppp->xstate &= ~SC_COMP_RUN; 2436 ocomp = ppp->xcomp; 2437 ostate = ppp->xc_state; 2438 ppp->xcomp = cp; 2439 ppp->xc_state = state; 2440 ppp_xmit_unlock(ppp); 2441 if (ostate) { 2442 ocomp->comp_free(ostate); 2443 module_put(ocomp->owner); 2444 } 2445 err = 0; 2446 } else 2447 module_put(cp->owner); 2448 2449 } else { 2450 state = cp->decomp_alloc(ccp_option, data.length); 2451 if (state) { 2452 ppp_recv_lock(ppp); 2453 ppp->rstate &= ~SC_DECOMP_RUN; 2454 ocomp = ppp->rcomp; 2455 ostate = ppp->rc_state; 2456 ppp->rcomp = cp; 2457 ppp->rc_state = state; 2458 ppp_recv_unlock(ppp); 2459 if (ostate) { 2460 ocomp->decomp_free(ostate); 2461 module_put(ocomp->owner); 2462 } 2463 err = 0; 2464 } else 2465 module_put(cp->owner); 2466 } 2467 2468 out: 2469 return err; 2470 } 2471 2472 /* 2473 * Look at a CCP packet and update our state accordingly. 2474 * We assume the caller has the xmit or recv path locked. 2475 */ 2476 static void 2477 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound) 2478 { 2479 unsigned char *dp; 2480 int len; 2481 2482 if (!pskb_may_pull(skb, CCP_HDRLEN + 2)) 2483 return; /* no header */ 2484 dp = skb->data + 2; 2485 2486 switch (CCP_CODE(dp)) { 2487 case CCP_CONFREQ: 2488 2489 /* A ConfReq starts negotiation of compression 2490 * in one direction of transmission, 2491 * and hence brings it down...but which way? 2492 * 2493 * Remember: 2494 * A ConfReq indicates what the sender would like to receive 2495 */ 2496 if(inbound) 2497 /* He is proposing what I should send */ 2498 ppp->xstate &= ~SC_COMP_RUN; 2499 else 2500 /* I am proposing to what he should send */ 2501 ppp->rstate &= ~SC_DECOMP_RUN; 2502 2503 break; 2504 2505 case CCP_TERMREQ: 2506 case CCP_TERMACK: 2507 /* 2508 * CCP is going down, both directions of transmission 2509 */ 2510 ppp->rstate &= ~SC_DECOMP_RUN; 2511 ppp->xstate &= ~SC_COMP_RUN; 2512 break; 2513 2514 case CCP_CONFACK: 2515 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN) 2516 break; 2517 len = CCP_LENGTH(dp); 2518 if (!pskb_may_pull(skb, len + 2)) 2519 return; /* too short */ 2520 dp += CCP_HDRLEN; 2521 len -= CCP_HDRLEN; 2522 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp)) 2523 break; 2524 if (inbound) { 2525 /* we will start receiving compressed packets */ 2526 if (!ppp->rc_state) 2527 break; 2528 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len, 2529 ppp->file.index, 0, ppp->mru, ppp->debug)) { 2530 ppp->rstate |= SC_DECOMP_RUN; 2531 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR); 2532 } 2533 } else { 2534 /* we will soon start sending compressed packets */ 2535 if (!ppp->xc_state) 2536 break; 2537 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len, 2538 ppp->file.index, 0, ppp->debug)) 2539 ppp->xstate |= SC_COMP_RUN; 2540 } 2541 break; 2542 2543 case CCP_RESETACK: 2544 /* reset the [de]compressor */ 2545 if ((ppp->flags & SC_CCP_UP) == 0) 2546 break; 2547 if (inbound) { 2548 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) { 2549 ppp->rcomp->decomp_reset(ppp->rc_state); 2550 ppp->rstate &= ~SC_DC_ERROR; 2551 } 2552 } else { 2553 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN)) 2554 ppp->xcomp->comp_reset(ppp->xc_state); 2555 } 2556 break; 2557 } 2558 } 2559 2560 /* Free up compression resources. */ 2561 static void 2562 ppp_ccp_closed(struct ppp *ppp) 2563 { 2564 void *xstate, *rstate; 2565 struct compressor *xcomp, *rcomp; 2566 2567 ppp_lock(ppp); 2568 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP); 2569 ppp->xstate = 0; 2570 xcomp = ppp->xcomp; 2571 xstate = ppp->xc_state; 2572 ppp->xc_state = NULL; 2573 ppp->rstate = 0; 2574 rcomp = ppp->rcomp; 2575 rstate = ppp->rc_state; 2576 ppp->rc_state = NULL; 2577 ppp_unlock(ppp); 2578 2579 if (xstate) { 2580 xcomp->comp_free(xstate); 2581 module_put(xcomp->owner); 2582 } 2583 if (rstate) { 2584 rcomp->decomp_free(rstate); 2585 module_put(rcomp->owner); 2586 } 2587 } 2588 2589 /* List of compressors. */ 2590 static LIST_HEAD(compressor_list); 2591 static DEFINE_SPINLOCK(compressor_list_lock); 2592 2593 struct compressor_entry { 2594 struct list_head list; 2595 struct compressor *comp; 2596 }; 2597 2598 static struct compressor_entry * 2599 find_comp_entry(int proto) 2600 { 2601 struct compressor_entry *ce; 2602 2603 list_for_each_entry(ce, &compressor_list, list) { 2604 if (ce->comp->compress_proto == proto) 2605 return ce; 2606 } 2607 return NULL; 2608 } 2609 2610 /* Register a compressor */ 2611 int 2612 ppp_register_compressor(struct compressor *cp) 2613 { 2614 struct compressor_entry *ce; 2615 int ret; 2616 spin_lock(&compressor_list_lock); 2617 ret = -EEXIST; 2618 if (find_comp_entry(cp->compress_proto)) 2619 goto out; 2620 ret = -ENOMEM; 2621 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC); 2622 if (!ce) 2623 goto out; 2624 ret = 0; 2625 ce->comp = cp; 2626 list_add(&ce->list, &compressor_list); 2627 out: 2628 spin_unlock(&compressor_list_lock); 2629 return ret; 2630 } 2631 2632 /* Unregister a compressor */ 2633 void 2634 ppp_unregister_compressor(struct compressor *cp) 2635 { 2636 struct compressor_entry *ce; 2637 2638 spin_lock(&compressor_list_lock); 2639 ce = find_comp_entry(cp->compress_proto); 2640 if (ce && ce->comp == cp) { 2641 list_del(&ce->list); 2642 kfree(ce); 2643 } 2644 spin_unlock(&compressor_list_lock); 2645 } 2646 2647 /* Find a compressor. */ 2648 static struct compressor * 2649 find_compressor(int type) 2650 { 2651 struct compressor_entry *ce; 2652 struct compressor *cp = NULL; 2653 2654 spin_lock(&compressor_list_lock); 2655 ce = find_comp_entry(type); 2656 if (ce) { 2657 cp = ce->comp; 2658 if (!try_module_get(cp->owner)) 2659 cp = NULL; 2660 } 2661 spin_unlock(&compressor_list_lock); 2662 return cp; 2663 } 2664 2665 /* 2666 * Miscelleneous stuff. 2667 */ 2668 2669 static void 2670 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st) 2671 { 2672 struct slcompress *vj = ppp->vj; 2673 2674 memset(st, 0, sizeof(*st)); 2675 st->p.ppp_ipackets = ppp->stats64.rx_packets; 2676 st->p.ppp_ierrors = ppp->dev->stats.rx_errors; 2677 st->p.ppp_ibytes = ppp->stats64.rx_bytes; 2678 st->p.ppp_opackets = ppp->stats64.tx_packets; 2679 st->p.ppp_oerrors = ppp->dev->stats.tx_errors; 2680 st->p.ppp_obytes = ppp->stats64.tx_bytes; 2681 if (!vj) 2682 return; 2683 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed; 2684 st->vj.vjs_compressed = vj->sls_o_compressed; 2685 st->vj.vjs_searches = vj->sls_o_searches; 2686 st->vj.vjs_misses = vj->sls_o_misses; 2687 st->vj.vjs_errorin = vj->sls_i_error; 2688 st->vj.vjs_tossed = vj->sls_i_tossed; 2689 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed; 2690 st->vj.vjs_compressedin = vj->sls_i_compressed; 2691 } 2692 2693 /* 2694 * Stuff for handling the lists of ppp units and channels 2695 * and for initialization. 2696 */ 2697 2698 /* 2699 * Create a new ppp interface unit. Fails if it can't allocate memory 2700 * or if there is already a unit with the requested number. 2701 * unit == -1 means allocate a new number. 2702 */ 2703 static struct ppp *ppp_create_interface(struct net *net, int unit, 2704 struct file *file, int *retp) 2705 { 2706 struct ppp *ppp; 2707 struct ppp_net *pn; 2708 struct net_device *dev = NULL; 2709 int ret = -ENOMEM; 2710 int i; 2711 2712 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_UNKNOWN, 2713 ppp_setup); 2714 if (!dev) 2715 goto out1; 2716 2717 pn = ppp_pernet(net); 2718 2719 ppp = netdev_priv(dev); 2720 ppp->dev = dev; 2721 ppp->mru = PPP_MRU; 2722 init_ppp_file(&ppp->file, INTERFACE); 2723 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */ 2724 ppp->owner = file; 2725 for (i = 0; i < NUM_NP; ++i) 2726 ppp->npmode[i] = NPMODE_PASS; 2727 INIT_LIST_HEAD(&ppp->channels); 2728 spin_lock_init(&ppp->rlock); 2729 spin_lock_init(&ppp->wlock); 2730 #ifdef CONFIG_PPP_MULTILINK 2731 ppp->minseq = -1; 2732 skb_queue_head_init(&ppp->mrq); 2733 #endif /* CONFIG_PPP_MULTILINK */ 2734 #ifdef CONFIG_PPP_FILTER 2735 ppp->pass_filter = NULL; 2736 ppp->active_filter = NULL; 2737 #endif /* CONFIG_PPP_FILTER */ 2738 2739 /* 2740 * drum roll: don't forget to set 2741 * the net device is belong to 2742 */ 2743 dev_net_set(dev, net); 2744 2745 mutex_lock(&pn->all_ppp_mutex); 2746 2747 if (unit < 0) { 2748 unit = unit_get(&pn->units_idr, ppp); 2749 if (unit < 0) { 2750 ret = unit; 2751 goto out2; 2752 } 2753 } else { 2754 ret = -EEXIST; 2755 if (unit_find(&pn->units_idr, unit)) 2756 goto out2; /* unit already exists */ 2757 /* 2758 * if caller need a specified unit number 2759 * lets try to satisfy him, otherwise -- 2760 * he should better ask us for new unit number 2761 * 2762 * NOTE: yes I know that returning EEXIST it's not 2763 * fair but at least pppd will ask us to allocate 2764 * new unit in this case so user is happy :) 2765 */ 2766 unit = unit_set(&pn->units_idr, ppp, unit); 2767 if (unit < 0) 2768 goto out2; 2769 } 2770 2771 /* Initialize the new ppp unit */ 2772 ppp->file.index = unit; 2773 sprintf(dev->name, "ppp%d", unit); 2774 2775 ret = register_netdev(dev); 2776 if (ret != 0) { 2777 unit_put(&pn->units_idr, unit); 2778 netdev_err(ppp->dev, "PPP: couldn't register device %s (%d)\n", 2779 dev->name, ret); 2780 goto out2; 2781 } 2782 2783 ppp->ppp_net = net; 2784 2785 atomic_inc(&ppp_unit_count); 2786 mutex_unlock(&pn->all_ppp_mutex); 2787 2788 *retp = 0; 2789 return ppp; 2790 2791 out2: 2792 mutex_unlock(&pn->all_ppp_mutex); 2793 free_netdev(dev); 2794 out1: 2795 *retp = ret; 2796 return NULL; 2797 } 2798 2799 /* 2800 * Initialize a ppp_file structure. 2801 */ 2802 static void 2803 init_ppp_file(struct ppp_file *pf, int kind) 2804 { 2805 pf->kind = kind; 2806 skb_queue_head_init(&pf->xq); 2807 skb_queue_head_init(&pf->rq); 2808 atomic_set(&pf->refcnt, 1); 2809 init_waitqueue_head(&pf->rwait); 2810 } 2811 2812 /* 2813 * Free the memory used by a ppp unit. This is only called once 2814 * there are no channels connected to the unit and no file structs 2815 * that reference the unit. 2816 */ 2817 static void ppp_destroy_interface(struct ppp *ppp) 2818 { 2819 atomic_dec(&ppp_unit_count); 2820 2821 if (!ppp->file.dead || ppp->n_channels) { 2822 /* "can't happen" */ 2823 netdev_err(ppp->dev, "ppp: destroying ppp struct %p " 2824 "but dead=%d n_channels=%d !\n", 2825 ppp, ppp->file.dead, ppp->n_channels); 2826 return; 2827 } 2828 2829 ppp_ccp_closed(ppp); 2830 if (ppp->vj) { 2831 slhc_free(ppp->vj); 2832 ppp->vj = NULL; 2833 } 2834 skb_queue_purge(&ppp->file.xq); 2835 skb_queue_purge(&ppp->file.rq); 2836 #ifdef CONFIG_PPP_MULTILINK 2837 skb_queue_purge(&ppp->mrq); 2838 #endif /* CONFIG_PPP_MULTILINK */ 2839 #ifdef CONFIG_PPP_FILTER 2840 if (ppp->pass_filter) { 2841 bpf_prog_destroy(ppp->pass_filter); 2842 ppp->pass_filter = NULL; 2843 } 2844 2845 if (ppp->active_filter) { 2846 bpf_prog_destroy(ppp->active_filter); 2847 ppp->active_filter = NULL; 2848 } 2849 #endif /* CONFIG_PPP_FILTER */ 2850 2851 kfree_skb(ppp->xmit_pending); 2852 2853 free_netdev(ppp->dev); 2854 } 2855 2856 /* 2857 * Locate an existing ppp unit. 2858 * The caller should have locked the all_ppp_mutex. 2859 */ 2860 static struct ppp * 2861 ppp_find_unit(struct ppp_net *pn, int unit) 2862 { 2863 return unit_find(&pn->units_idr, unit); 2864 } 2865 2866 /* 2867 * Locate an existing ppp channel. 2868 * The caller should have locked the all_channels_lock. 2869 * First we look in the new_channels list, then in the 2870 * all_channels list. If found in the new_channels list, 2871 * we move it to the all_channels list. This is for speed 2872 * when we have a lot of channels in use. 2873 */ 2874 static struct channel * 2875 ppp_find_channel(struct ppp_net *pn, int unit) 2876 { 2877 struct channel *pch; 2878 2879 list_for_each_entry(pch, &pn->new_channels, list) { 2880 if (pch->file.index == unit) { 2881 list_move(&pch->list, &pn->all_channels); 2882 return pch; 2883 } 2884 } 2885 2886 list_for_each_entry(pch, &pn->all_channels, list) { 2887 if (pch->file.index == unit) 2888 return pch; 2889 } 2890 2891 return NULL; 2892 } 2893 2894 /* 2895 * Connect a PPP channel to a PPP interface unit. 2896 */ 2897 static int 2898 ppp_connect_channel(struct channel *pch, int unit) 2899 { 2900 struct ppp *ppp; 2901 struct ppp_net *pn; 2902 int ret = -ENXIO; 2903 int hdrlen; 2904 2905 pn = ppp_pernet(pch->chan_net); 2906 2907 mutex_lock(&pn->all_ppp_mutex); 2908 ppp = ppp_find_unit(pn, unit); 2909 if (!ppp) 2910 goto out; 2911 write_lock_bh(&pch->upl); 2912 ret = -EINVAL; 2913 if (pch->ppp) 2914 goto outl; 2915 2916 ppp_lock(ppp); 2917 if (pch->file.hdrlen > ppp->file.hdrlen) 2918 ppp->file.hdrlen = pch->file.hdrlen; 2919 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */ 2920 if (hdrlen > ppp->dev->hard_header_len) 2921 ppp->dev->hard_header_len = hdrlen; 2922 list_add_tail(&pch->clist, &ppp->channels); 2923 ++ppp->n_channels; 2924 pch->ppp = ppp; 2925 atomic_inc(&ppp->file.refcnt); 2926 ppp_unlock(ppp); 2927 ret = 0; 2928 2929 outl: 2930 write_unlock_bh(&pch->upl); 2931 out: 2932 mutex_unlock(&pn->all_ppp_mutex); 2933 return ret; 2934 } 2935 2936 /* 2937 * Disconnect a channel from its ppp unit. 2938 */ 2939 static int 2940 ppp_disconnect_channel(struct channel *pch) 2941 { 2942 struct ppp *ppp; 2943 int err = -EINVAL; 2944 2945 write_lock_bh(&pch->upl); 2946 ppp = pch->ppp; 2947 pch->ppp = NULL; 2948 write_unlock_bh(&pch->upl); 2949 if (ppp) { 2950 /* remove it from the ppp unit's list */ 2951 ppp_lock(ppp); 2952 list_del(&pch->clist); 2953 if (--ppp->n_channels == 0) 2954 wake_up_interruptible(&ppp->file.rwait); 2955 ppp_unlock(ppp); 2956 if (atomic_dec_and_test(&ppp->file.refcnt)) 2957 ppp_destroy_interface(ppp); 2958 err = 0; 2959 } 2960 return err; 2961 } 2962 2963 /* 2964 * Free up the resources used by a ppp channel. 2965 */ 2966 static void ppp_destroy_channel(struct channel *pch) 2967 { 2968 atomic_dec(&channel_count); 2969 2970 if (!pch->file.dead) { 2971 /* "can't happen" */ 2972 pr_err("ppp: destroying undead channel %p !\n", pch); 2973 return; 2974 } 2975 skb_queue_purge(&pch->file.xq); 2976 skb_queue_purge(&pch->file.rq); 2977 kfree(pch); 2978 } 2979 2980 static void __exit ppp_cleanup(void) 2981 { 2982 /* should never happen */ 2983 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count)) 2984 pr_err("PPP: removing module but units remain!\n"); 2985 unregister_chrdev(PPP_MAJOR, "ppp"); 2986 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0)); 2987 class_destroy(ppp_class); 2988 unregister_pernet_device(&ppp_net_ops); 2989 } 2990 2991 /* 2992 * Units handling. Caller must protect concurrent access 2993 * by holding all_ppp_mutex 2994 */ 2995 2996 /* associate pointer with specified number */ 2997 static int unit_set(struct idr *p, void *ptr, int n) 2998 { 2999 int unit; 3000 3001 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL); 3002 if (unit == -ENOSPC) 3003 unit = -EINVAL; 3004 return unit; 3005 } 3006 3007 /* get new free unit number and associate pointer with it */ 3008 static int unit_get(struct idr *p, void *ptr) 3009 { 3010 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL); 3011 } 3012 3013 /* put unit number back to a pool */ 3014 static void unit_put(struct idr *p, int n) 3015 { 3016 idr_remove(p, n); 3017 } 3018 3019 /* get pointer associated with the number */ 3020 static void *unit_find(struct idr *p, int n) 3021 { 3022 return idr_find(p, n); 3023 } 3024 3025 /* Module/initialization stuff */ 3026 3027 module_init(ppp_init); 3028 module_exit(ppp_cleanup); 3029 3030 EXPORT_SYMBOL(ppp_register_net_channel); 3031 EXPORT_SYMBOL(ppp_register_channel); 3032 EXPORT_SYMBOL(ppp_unregister_channel); 3033 EXPORT_SYMBOL(ppp_channel_index); 3034 EXPORT_SYMBOL(ppp_unit_number); 3035 EXPORT_SYMBOL(ppp_dev_name); 3036 EXPORT_SYMBOL(ppp_input); 3037 EXPORT_SYMBOL(ppp_input_error); 3038 EXPORT_SYMBOL(ppp_output_wakeup); 3039 EXPORT_SYMBOL(ppp_register_compressor); 3040 EXPORT_SYMBOL(ppp_unregister_compressor); 3041 MODULE_LICENSE("GPL"); 3042 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0); 3043 MODULE_ALIAS("devname:ppp"); 3044