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 const struct net_device_ops ppp_netdev_ops; 287 288 static struct class *ppp_class; 289 290 /* per net-namespace data */ 291 static inline struct ppp_net *ppp_pernet(struct net *net) 292 { 293 BUG_ON(!net); 294 295 return net_generic(net, ppp_net_id); 296 } 297 298 /* Translates a PPP protocol number to a NP index (NP == network protocol) */ 299 static inline int proto_to_npindex(int proto) 300 { 301 switch (proto) { 302 case PPP_IP: 303 return NP_IP; 304 case PPP_IPV6: 305 return NP_IPV6; 306 case PPP_IPX: 307 return NP_IPX; 308 case PPP_AT: 309 return NP_AT; 310 case PPP_MPLS_UC: 311 return NP_MPLS_UC; 312 case PPP_MPLS_MC: 313 return NP_MPLS_MC; 314 } 315 return -EINVAL; 316 } 317 318 /* Translates an NP index into a PPP protocol number */ 319 static const int npindex_to_proto[NUM_NP] = { 320 PPP_IP, 321 PPP_IPV6, 322 PPP_IPX, 323 PPP_AT, 324 PPP_MPLS_UC, 325 PPP_MPLS_MC, 326 }; 327 328 /* Translates an ethertype into an NP index */ 329 static inline int ethertype_to_npindex(int ethertype) 330 { 331 switch (ethertype) { 332 case ETH_P_IP: 333 return NP_IP; 334 case ETH_P_IPV6: 335 return NP_IPV6; 336 case ETH_P_IPX: 337 return NP_IPX; 338 case ETH_P_PPPTALK: 339 case ETH_P_ATALK: 340 return NP_AT; 341 case ETH_P_MPLS_UC: 342 return NP_MPLS_UC; 343 case ETH_P_MPLS_MC: 344 return NP_MPLS_MC; 345 } 346 return -1; 347 } 348 349 /* Translates an NP index into an ethertype */ 350 static const int npindex_to_ethertype[NUM_NP] = { 351 ETH_P_IP, 352 ETH_P_IPV6, 353 ETH_P_IPX, 354 ETH_P_PPPTALK, 355 ETH_P_MPLS_UC, 356 ETH_P_MPLS_MC, 357 }; 358 359 /* 360 * Locking shorthand. 361 */ 362 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock) 363 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock) 364 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock) 365 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock) 366 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \ 367 ppp_recv_lock(ppp); } while (0) 368 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \ 369 ppp_xmit_unlock(ppp); } while (0) 370 371 /* 372 * /dev/ppp device routines. 373 * The /dev/ppp device is used by pppd to control the ppp unit. 374 * It supports the read, write, ioctl and poll functions. 375 * Open instances of /dev/ppp can be in one of three states: 376 * unattached, attached to a ppp unit, or attached to a ppp channel. 377 */ 378 static int ppp_open(struct inode *inode, struct file *file) 379 { 380 /* 381 * This could (should?) be enforced by the permissions on /dev/ppp. 382 */ 383 if (!capable(CAP_NET_ADMIN)) 384 return -EPERM; 385 return 0; 386 } 387 388 static int ppp_release(struct inode *unused, struct file *file) 389 { 390 struct ppp_file *pf = file->private_data; 391 struct ppp *ppp; 392 393 if (pf) { 394 file->private_data = NULL; 395 if (pf->kind == INTERFACE) { 396 ppp = PF_TO_PPP(pf); 397 rtnl_lock(); 398 if (file == ppp->owner) 399 unregister_netdevice(ppp->dev); 400 rtnl_unlock(); 401 } 402 if (atomic_dec_and_test(&pf->refcnt)) { 403 switch (pf->kind) { 404 case INTERFACE: 405 ppp_destroy_interface(PF_TO_PPP(pf)); 406 break; 407 case CHANNEL: 408 ppp_destroy_channel(PF_TO_CHANNEL(pf)); 409 break; 410 } 411 } 412 } 413 return 0; 414 } 415 416 static ssize_t ppp_read(struct file *file, char __user *buf, 417 size_t count, loff_t *ppos) 418 { 419 struct ppp_file *pf = file->private_data; 420 DECLARE_WAITQUEUE(wait, current); 421 ssize_t ret; 422 struct sk_buff *skb = NULL; 423 struct iovec iov; 424 struct iov_iter to; 425 426 ret = count; 427 428 if (!pf) 429 return -ENXIO; 430 add_wait_queue(&pf->rwait, &wait); 431 for (;;) { 432 set_current_state(TASK_INTERRUPTIBLE); 433 skb = skb_dequeue(&pf->rq); 434 if (skb) 435 break; 436 ret = 0; 437 if (pf->dead) 438 break; 439 if (pf->kind == INTERFACE) { 440 /* 441 * Return 0 (EOF) on an interface that has no 442 * channels connected, unless it is looping 443 * network traffic (demand mode). 444 */ 445 struct ppp *ppp = PF_TO_PPP(pf); 446 447 ppp_recv_lock(ppp); 448 if (ppp->n_channels == 0 && 449 (ppp->flags & SC_LOOP_TRAFFIC) == 0) { 450 ppp_recv_unlock(ppp); 451 break; 452 } 453 ppp_recv_unlock(ppp); 454 } 455 ret = -EAGAIN; 456 if (file->f_flags & O_NONBLOCK) 457 break; 458 ret = -ERESTARTSYS; 459 if (signal_pending(current)) 460 break; 461 schedule(); 462 } 463 set_current_state(TASK_RUNNING); 464 remove_wait_queue(&pf->rwait, &wait); 465 466 if (!skb) 467 goto out; 468 469 ret = -EOVERFLOW; 470 if (skb->len > count) 471 goto outf; 472 ret = -EFAULT; 473 iov.iov_base = buf; 474 iov.iov_len = count; 475 iov_iter_init(&to, READ, &iov, 1, count); 476 if (skb_copy_datagram_iter(skb, 0, &to, skb->len)) 477 goto outf; 478 ret = skb->len; 479 480 outf: 481 kfree_skb(skb); 482 out: 483 return ret; 484 } 485 486 static ssize_t ppp_write(struct file *file, const char __user *buf, 487 size_t count, loff_t *ppos) 488 { 489 struct ppp_file *pf = file->private_data; 490 struct sk_buff *skb; 491 ssize_t ret; 492 493 if (!pf) 494 return -ENXIO; 495 ret = -ENOMEM; 496 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL); 497 if (!skb) 498 goto out; 499 skb_reserve(skb, pf->hdrlen); 500 ret = -EFAULT; 501 if (copy_from_user(skb_put(skb, count), buf, count)) { 502 kfree_skb(skb); 503 goto out; 504 } 505 506 skb_queue_tail(&pf->xq, skb); 507 508 switch (pf->kind) { 509 case INTERFACE: 510 ppp_xmit_process(PF_TO_PPP(pf)); 511 break; 512 case CHANNEL: 513 ppp_channel_push(PF_TO_CHANNEL(pf)); 514 break; 515 } 516 517 ret = count; 518 519 out: 520 return ret; 521 } 522 523 /* No kernel lock - fine */ 524 static unsigned int ppp_poll(struct file *file, poll_table *wait) 525 { 526 struct ppp_file *pf = file->private_data; 527 unsigned int mask; 528 529 if (!pf) 530 return 0; 531 poll_wait(file, &pf->rwait, wait); 532 mask = POLLOUT | POLLWRNORM; 533 if (skb_peek(&pf->rq)) 534 mask |= POLLIN | POLLRDNORM; 535 if (pf->dead) 536 mask |= POLLHUP; 537 else if (pf->kind == INTERFACE) { 538 /* see comment in ppp_read */ 539 struct ppp *ppp = PF_TO_PPP(pf); 540 541 ppp_recv_lock(ppp); 542 if (ppp->n_channels == 0 && 543 (ppp->flags & SC_LOOP_TRAFFIC) == 0) 544 mask |= POLLIN | POLLRDNORM; 545 ppp_recv_unlock(ppp); 546 } 547 548 return mask; 549 } 550 551 #ifdef CONFIG_PPP_FILTER 552 static int get_filter(void __user *arg, struct sock_filter **p) 553 { 554 struct sock_fprog uprog; 555 struct sock_filter *code = NULL; 556 int len; 557 558 if (copy_from_user(&uprog, arg, sizeof(uprog))) 559 return -EFAULT; 560 561 if (!uprog.len) { 562 *p = NULL; 563 return 0; 564 } 565 566 len = uprog.len * sizeof(struct sock_filter); 567 code = memdup_user(uprog.filter, len); 568 if (IS_ERR(code)) 569 return PTR_ERR(code); 570 571 *p = code; 572 return uprog.len; 573 } 574 #endif /* CONFIG_PPP_FILTER */ 575 576 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 577 { 578 struct ppp_file *pf; 579 struct ppp *ppp; 580 int err = -EFAULT, val, val2, i; 581 struct ppp_idle idle; 582 struct npioctl npi; 583 int unit, cflags; 584 struct slcompress *vj; 585 void __user *argp = (void __user *)arg; 586 int __user *p = argp; 587 588 mutex_lock(&ppp_mutex); 589 590 pf = file->private_data; 591 if (!pf) { 592 err = ppp_unattached_ioctl(current->nsproxy->net_ns, 593 pf, file, cmd, arg); 594 goto out; 595 } 596 597 if (cmd == PPPIOCDETACH) { 598 /* 599 * We have to be careful here... if the file descriptor 600 * has been dup'd, we could have another process in the 601 * middle of a poll using the same file *, so we had 602 * better not free the interface data structures - 603 * instead we fail the ioctl. Even in this case, we 604 * shut down the interface if we are the owner of it. 605 * Actually, we should get rid of PPPIOCDETACH, userland 606 * (i.e. pppd) could achieve the same effect by closing 607 * this fd and reopening /dev/ppp. 608 */ 609 err = -EINVAL; 610 if (pf->kind == INTERFACE) { 611 ppp = PF_TO_PPP(pf); 612 rtnl_lock(); 613 if (file == ppp->owner) 614 unregister_netdevice(ppp->dev); 615 rtnl_unlock(); 616 } 617 if (atomic_long_read(&file->f_count) < 2) { 618 ppp_release(NULL, file); 619 err = 0; 620 } else 621 pr_warn("PPPIOCDETACH file->f_count=%ld\n", 622 atomic_long_read(&file->f_count)); 623 goto out; 624 } 625 626 if (pf->kind == CHANNEL) { 627 struct channel *pch; 628 struct ppp_channel *chan; 629 630 pch = PF_TO_CHANNEL(pf); 631 632 switch (cmd) { 633 case PPPIOCCONNECT: 634 if (get_user(unit, p)) 635 break; 636 err = ppp_connect_channel(pch, unit); 637 break; 638 639 case PPPIOCDISCONN: 640 err = ppp_disconnect_channel(pch); 641 break; 642 643 default: 644 down_read(&pch->chan_sem); 645 chan = pch->chan; 646 err = -ENOTTY; 647 if (chan && chan->ops->ioctl) 648 err = chan->ops->ioctl(chan, cmd, arg); 649 up_read(&pch->chan_sem); 650 } 651 goto out; 652 } 653 654 if (pf->kind != INTERFACE) { 655 /* can't happen */ 656 pr_err("PPP: not interface or channel??\n"); 657 err = -EINVAL; 658 goto out; 659 } 660 661 ppp = PF_TO_PPP(pf); 662 switch (cmd) { 663 case PPPIOCSMRU: 664 if (get_user(val, p)) 665 break; 666 ppp->mru = val; 667 err = 0; 668 break; 669 670 case PPPIOCSFLAGS: 671 if (get_user(val, p)) 672 break; 673 ppp_lock(ppp); 674 cflags = ppp->flags & ~val; 675 #ifdef CONFIG_PPP_MULTILINK 676 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK)) 677 ppp->nextseq = 0; 678 #endif 679 ppp->flags = val & SC_FLAG_BITS; 680 ppp_unlock(ppp); 681 if (cflags & SC_CCP_OPEN) 682 ppp_ccp_closed(ppp); 683 err = 0; 684 break; 685 686 case PPPIOCGFLAGS: 687 val = ppp->flags | ppp->xstate | ppp->rstate; 688 if (put_user(val, p)) 689 break; 690 err = 0; 691 break; 692 693 case PPPIOCSCOMPRESS: 694 err = ppp_set_compress(ppp, arg); 695 break; 696 697 case PPPIOCGUNIT: 698 if (put_user(ppp->file.index, p)) 699 break; 700 err = 0; 701 break; 702 703 case PPPIOCSDEBUG: 704 if (get_user(val, p)) 705 break; 706 ppp->debug = val; 707 err = 0; 708 break; 709 710 case PPPIOCGDEBUG: 711 if (put_user(ppp->debug, p)) 712 break; 713 err = 0; 714 break; 715 716 case PPPIOCGIDLE: 717 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ; 718 idle.recv_idle = (jiffies - ppp->last_recv) / HZ; 719 if (copy_to_user(argp, &idle, sizeof(idle))) 720 break; 721 err = 0; 722 break; 723 724 case PPPIOCSMAXCID: 725 if (get_user(val, p)) 726 break; 727 val2 = 15; 728 if ((val >> 16) != 0) { 729 val2 = val >> 16; 730 val &= 0xffff; 731 } 732 vj = slhc_init(val2+1, val+1); 733 if (IS_ERR(vj)) { 734 err = PTR_ERR(vj); 735 break; 736 } 737 ppp_lock(ppp); 738 if (ppp->vj) 739 slhc_free(ppp->vj); 740 ppp->vj = vj; 741 ppp_unlock(ppp); 742 err = 0; 743 break; 744 745 case PPPIOCGNPMODE: 746 case PPPIOCSNPMODE: 747 if (copy_from_user(&npi, argp, sizeof(npi))) 748 break; 749 err = proto_to_npindex(npi.protocol); 750 if (err < 0) 751 break; 752 i = err; 753 if (cmd == PPPIOCGNPMODE) { 754 err = -EFAULT; 755 npi.mode = ppp->npmode[i]; 756 if (copy_to_user(argp, &npi, sizeof(npi))) 757 break; 758 } else { 759 ppp->npmode[i] = npi.mode; 760 /* we may be able to transmit more packets now (??) */ 761 netif_wake_queue(ppp->dev); 762 } 763 err = 0; 764 break; 765 766 #ifdef CONFIG_PPP_FILTER 767 case PPPIOCSPASS: 768 { 769 struct sock_filter *code; 770 771 err = get_filter(argp, &code); 772 if (err >= 0) { 773 struct bpf_prog *pass_filter = NULL; 774 struct sock_fprog_kern fprog = { 775 .len = err, 776 .filter = code, 777 }; 778 779 err = 0; 780 if (fprog.filter) 781 err = bpf_prog_create(&pass_filter, &fprog); 782 if (!err) { 783 ppp_lock(ppp); 784 if (ppp->pass_filter) 785 bpf_prog_destroy(ppp->pass_filter); 786 ppp->pass_filter = pass_filter; 787 ppp_unlock(ppp); 788 } 789 kfree(code); 790 } 791 break; 792 } 793 case PPPIOCSACTIVE: 794 { 795 struct sock_filter *code; 796 797 err = get_filter(argp, &code); 798 if (err >= 0) { 799 struct bpf_prog *active_filter = NULL; 800 struct sock_fprog_kern fprog = { 801 .len = err, 802 .filter = code, 803 }; 804 805 err = 0; 806 if (fprog.filter) 807 err = bpf_prog_create(&active_filter, &fprog); 808 if (!err) { 809 ppp_lock(ppp); 810 if (ppp->active_filter) 811 bpf_prog_destroy(ppp->active_filter); 812 ppp->active_filter = active_filter; 813 ppp_unlock(ppp); 814 } 815 kfree(code); 816 } 817 break; 818 } 819 #endif /* CONFIG_PPP_FILTER */ 820 821 #ifdef CONFIG_PPP_MULTILINK 822 case PPPIOCSMRRU: 823 if (get_user(val, p)) 824 break; 825 ppp_recv_lock(ppp); 826 ppp->mrru = val; 827 ppp_recv_unlock(ppp); 828 err = 0; 829 break; 830 #endif /* CONFIG_PPP_MULTILINK */ 831 832 default: 833 err = -ENOTTY; 834 } 835 836 out: 837 mutex_unlock(&ppp_mutex); 838 839 return err; 840 } 841 842 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 843 struct file *file, unsigned int cmd, unsigned long arg) 844 { 845 int unit, err = -EFAULT; 846 struct ppp *ppp; 847 struct channel *chan; 848 struct ppp_net *pn; 849 int __user *p = (int __user *)arg; 850 851 switch (cmd) { 852 case PPPIOCNEWUNIT: 853 /* Create a new ppp unit */ 854 if (get_user(unit, p)) 855 break; 856 ppp = ppp_create_interface(net, unit, file, &err); 857 if (!ppp) 858 break; 859 file->private_data = &ppp->file; 860 err = -EFAULT; 861 if (put_user(ppp->file.index, p)) 862 break; 863 err = 0; 864 break; 865 866 case PPPIOCATTACH: 867 /* Attach to an existing ppp unit */ 868 if (get_user(unit, p)) 869 break; 870 err = -ENXIO; 871 pn = ppp_pernet(net); 872 mutex_lock(&pn->all_ppp_mutex); 873 ppp = ppp_find_unit(pn, unit); 874 if (ppp) { 875 atomic_inc(&ppp->file.refcnt); 876 file->private_data = &ppp->file; 877 err = 0; 878 } 879 mutex_unlock(&pn->all_ppp_mutex); 880 break; 881 882 case PPPIOCATTCHAN: 883 if (get_user(unit, p)) 884 break; 885 err = -ENXIO; 886 pn = ppp_pernet(net); 887 spin_lock_bh(&pn->all_channels_lock); 888 chan = ppp_find_channel(pn, unit); 889 if (chan) { 890 atomic_inc(&chan->file.refcnt); 891 file->private_data = &chan->file; 892 err = 0; 893 } 894 spin_unlock_bh(&pn->all_channels_lock); 895 break; 896 897 default: 898 err = -ENOTTY; 899 } 900 901 return err; 902 } 903 904 static const struct file_operations ppp_device_fops = { 905 .owner = THIS_MODULE, 906 .read = ppp_read, 907 .write = ppp_write, 908 .poll = ppp_poll, 909 .unlocked_ioctl = ppp_ioctl, 910 .open = ppp_open, 911 .release = ppp_release, 912 .llseek = noop_llseek, 913 }; 914 915 static __net_init int ppp_init_net(struct net *net) 916 { 917 struct ppp_net *pn = net_generic(net, ppp_net_id); 918 919 idr_init(&pn->units_idr); 920 mutex_init(&pn->all_ppp_mutex); 921 922 INIT_LIST_HEAD(&pn->all_channels); 923 INIT_LIST_HEAD(&pn->new_channels); 924 925 spin_lock_init(&pn->all_channels_lock); 926 927 return 0; 928 } 929 930 static __net_exit void ppp_exit_net(struct net *net) 931 { 932 struct ppp_net *pn = net_generic(net, ppp_net_id); 933 struct net_device *dev; 934 struct net_device *aux; 935 struct ppp *ppp; 936 LIST_HEAD(list); 937 int id; 938 939 rtnl_lock(); 940 for_each_netdev_safe(net, dev, aux) { 941 if (dev->netdev_ops == &ppp_netdev_ops) 942 unregister_netdevice_queue(dev, &list); 943 } 944 945 idr_for_each_entry(&pn->units_idr, ppp, id) 946 /* Skip devices already unregistered by previous loop */ 947 if (!net_eq(dev_net(ppp->dev), net)) 948 unregister_netdevice_queue(ppp->dev, &list); 949 950 unregister_netdevice_many(&list); 951 rtnl_unlock(); 952 953 idr_destroy(&pn->units_idr); 954 } 955 956 static struct pernet_operations ppp_net_ops = { 957 .init = ppp_init_net, 958 .exit = ppp_exit_net, 959 .id = &ppp_net_id, 960 .size = sizeof(struct ppp_net), 961 }; 962 963 #define PPP_MAJOR 108 964 965 /* Called at boot time if ppp is compiled into the kernel, 966 or at module load time (from init_module) if compiled as a module. */ 967 static int __init ppp_init(void) 968 { 969 int err; 970 971 pr_info("PPP generic driver version " PPP_VERSION "\n"); 972 973 err = register_pernet_device(&ppp_net_ops); 974 if (err) { 975 pr_err("failed to register PPP pernet device (%d)\n", err); 976 goto out; 977 } 978 979 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops); 980 if (err) { 981 pr_err("failed to register PPP device (%d)\n", err); 982 goto out_net; 983 } 984 985 ppp_class = class_create(THIS_MODULE, "ppp"); 986 if (IS_ERR(ppp_class)) { 987 err = PTR_ERR(ppp_class); 988 goto out_chrdev; 989 } 990 991 /* not a big deal if we fail here :-) */ 992 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp"); 993 994 return 0; 995 996 out_chrdev: 997 unregister_chrdev(PPP_MAJOR, "ppp"); 998 out_net: 999 unregister_pernet_device(&ppp_net_ops); 1000 out: 1001 return err; 1002 } 1003 1004 /* 1005 * Network interface unit routines. 1006 */ 1007 static netdev_tx_t 1008 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev) 1009 { 1010 struct ppp *ppp = netdev_priv(dev); 1011 int npi, proto; 1012 unsigned char *pp; 1013 1014 npi = ethertype_to_npindex(ntohs(skb->protocol)); 1015 if (npi < 0) 1016 goto outf; 1017 1018 /* Drop, accept or reject the packet */ 1019 switch (ppp->npmode[npi]) { 1020 case NPMODE_PASS: 1021 break; 1022 case NPMODE_QUEUE: 1023 /* it would be nice to have a way to tell the network 1024 system to queue this one up for later. */ 1025 goto outf; 1026 case NPMODE_DROP: 1027 case NPMODE_ERROR: 1028 goto outf; 1029 } 1030 1031 /* Put the 2-byte PPP protocol number on the front, 1032 making sure there is room for the address and control fields. */ 1033 if (skb_cow_head(skb, PPP_HDRLEN)) 1034 goto outf; 1035 1036 pp = skb_push(skb, 2); 1037 proto = npindex_to_proto[npi]; 1038 put_unaligned_be16(proto, pp); 1039 1040 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev))); 1041 skb_queue_tail(&ppp->file.xq, skb); 1042 ppp_xmit_process(ppp); 1043 return NETDEV_TX_OK; 1044 1045 outf: 1046 kfree_skb(skb); 1047 ++dev->stats.tx_dropped; 1048 return NETDEV_TX_OK; 1049 } 1050 1051 static int 1052 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 1053 { 1054 struct ppp *ppp = netdev_priv(dev); 1055 int err = -EFAULT; 1056 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data; 1057 struct ppp_stats stats; 1058 struct ppp_comp_stats cstats; 1059 char *vers; 1060 1061 switch (cmd) { 1062 case SIOCGPPPSTATS: 1063 ppp_get_stats(ppp, &stats); 1064 if (copy_to_user(addr, &stats, sizeof(stats))) 1065 break; 1066 err = 0; 1067 break; 1068 1069 case SIOCGPPPCSTATS: 1070 memset(&cstats, 0, sizeof(cstats)); 1071 if (ppp->xc_state) 1072 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c); 1073 if (ppp->rc_state) 1074 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d); 1075 if (copy_to_user(addr, &cstats, sizeof(cstats))) 1076 break; 1077 err = 0; 1078 break; 1079 1080 case SIOCGPPPVER: 1081 vers = PPP_VERSION; 1082 if (copy_to_user(addr, vers, strlen(vers) + 1)) 1083 break; 1084 err = 0; 1085 break; 1086 1087 default: 1088 err = -EINVAL; 1089 } 1090 1091 return err; 1092 } 1093 1094 static struct rtnl_link_stats64* 1095 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64) 1096 { 1097 struct ppp *ppp = netdev_priv(dev); 1098 1099 ppp_recv_lock(ppp); 1100 stats64->rx_packets = ppp->stats64.rx_packets; 1101 stats64->rx_bytes = ppp->stats64.rx_bytes; 1102 ppp_recv_unlock(ppp); 1103 1104 ppp_xmit_lock(ppp); 1105 stats64->tx_packets = ppp->stats64.tx_packets; 1106 stats64->tx_bytes = ppp->stats64.tx_bytes; 1107 ppp_xmit_unlock(ppp); 1108 1109 stats64->rx_errors = dev->stats.rx_errors; 1110 stats64->tx_errors = dev->stats.tx_errors; 1111 stats64->rx_dropped = dev->stats.rx_dropped; 1112 stats64->tx_dropped = dev->stats.tx_dropped; 1113 stats64->rx_length_errors = dev->stats.rx_length_errors; 1114 1115 return stats64; 1116 } 1117 1118 static struct lock_class_key ppp_tx_busylock; 1119 static int ppp_dev_init(struct net_device *dev) 1120 { 1121 dev->qdisc_tx_busylock = &ppp_tx_busylock; 1122 return 0; 1123 } 1124 1125 static void ppp_dev_uninit(struct net_device *dev) 1126 { 1127 struct ppp *ppp = netdev_priv(dev); 1128 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 1129 1130 ppp_lock(ppp); 1131 ppp->closing = 1; 1132 ppp_unlock(ppp); 1133 1134 mutex_lock(&pn->all_ppp_mutex); 1135 unit_put(&pn->units_idr, ppp->file.index); 1136 mutex_unlock(&pn->all_ppp_mutex); 1137 1138 ppp->owner = NULL; 1139 1140 ppp->file.dead = 1; 1141 wake_up_interruptible(&ppp->file.rwait); 1142 } 1143 1144 static const struct net_device_ops ppp_netdev_ops = { 1145 .ndo_init = ppp_dev_init, 1146 .ndo_uninit = ppp_dev_uninit, 1147 .ndo_start_xmit = ppp_start_xmit, 1148 .ndo_do_ioctl = ppp_net_ioctl, 1149 .ndo_get_stats64 = ppp_get_stats64, 1150 }; 1151 1152 static struct device_type ppp_type = { 1153 .name = "ppp", 1154 }; 1155 1156 static void ppp_setup(struct net_device *dev) 1157 { 1158 dev->netdev_ops = &ppp_netdev_ops; 1159 SET_NETDEV_DEVTYPE(dev, &ppp_type); 1160 1161 dev->hard_header_len = PPP_HDRLEN; 1162 dev->mtu = PPP_MRU; 1163 dev->addr_len = 0; 1164 dev->tx_queue_len = 3; 1165 dev->type = ARPHRD_PPP; 1166 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 1167 netif_keep_dst(dev); 1168 } 1169 1170 /* 1171 * Transmit-side routines. 1172 */ 1173 1174 /* 1175 * Called to do any work queued up on the transmit side 1176 * that can now be done. 1177 */ 1178 static void 1179 ppp_xmit_process(struct ppp *ppp) 1180 { 1181 struct sk_buff *skb; 1182 1183 ppp_xmit_lock(ppp); 1184 if (!ppp->closing) { 1185 ppp_push(ppp); 1186 while (!ppp->xmit_pending && 1187 (skb = skb_dequeue(&ppp->file.xq))) 1188 ppp_send_frame(ppp, skb); 1189 /* If there's no work left to do, tell the core net 1190 code that we can accept some more. */ 1191 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq)) 1192 netif_wake_queue(ppp->dev); 1193 else 1194 netif_stop_queue(ppp->dev); 1195 } 1196 ppp_xmit_unlock(ppp); 1197 } 1198 1199 static inline struct sk_buff * 1200 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) 1201 { 1202 struct sk_buff *new_skb; 1203 int len; 1204 int new_skb_size = ppp->dev->mtu + 1205 ppp->xcomp->comp_extra + ppp->dev->hard_header_len; 1206 int compressor_skb_size = ppp->dev->mtu + 1207 ppp->xcomp->comp_extra + PPP_HDRLEN; 1208 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC); 1209 if (!new_skb) { 1210 if (net_ratelimit()) 1211 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n"); 1212 return NULL; 1213 } 1214 if (ppp->dev->hard_header_len > PPP_HDRLEN) 1215 skb_reserve(new_skb, 1216 ppp->dev->hard_header_len - PPP_HDRLEN); 1217 1218 /* compressor still expects A/C bytes in hdr */ 1219 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, 1220 new_skb->data, skb->len + 2, 1221 compressor_skb_size); 1222 if (len > 0 && (ppp->flags & SC_CCP_UP)) { 1223 consume_skb(skb); 1224 skb = new_skb; 1225 skb_put(skb, len); 1226 skb_pull(skb, 2); /* pull off A/C bytes */ 1227 } else if (len == 0) { 1228 /* didn't compress, or CCP not up yet */ 1229 consume_skb(new_skb); 1230 new_skb = skb; 1231 } else { 1232 /* 1233 * (len < 0) 1234 * MPPE requires that we do not send unencrypted 1235 * frames. The compressor will return -1 if we 1236 * should drop the frame. We cannot simply test 1237 * the compress_proto because MPPE and MPPC share 1238 * the same number. 1239 */ 1240 if (net_ratelimit()) 1241 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n"); 1242 kfree_skb(skb); 1243 consume_skb(new_skb); 1244 new_skb = NULL; 1245 } 1246 return new_skb; 1247 } 1248 1249 /* 1250 * Compress and send a frame. 1251 * The caller should have locked the xmit path, 1252 * and xmit_pending should be 0. 1253 */ 1254 static void 1255 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) 1256 { 1257 int proto = PPP_PROTO(skb); 1258 struct sk_buff *new_skb; 1259 int len; 1260 unsigned char *cp; 1261 1262 if (proto < 0x8000) { 1263 #ifdef CONFIG_PPP_FILTER 1264 /* check if we should pass this packet */ 1265 /* the filter instructions are constructed assuming 1266 a four-byte PPP header on each packet */ 1267 *skb_push(skb, 2) = 1; 1268 if (ppp->pass_filter && 1269 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 1270 if (ppp->debug & 1) 1271 netdev_printk(KERN_DEBUG, ppp->dev, 1272 "PPP: outbound frame " 1273 "not passed\n"); 1274 kfree_skb(skb); 1275 return; 1276 } 1277 /* if this packet passes the active filter, record the time */ 1278 if (!(ppp->active_filter && 1279 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 1280 ppp->last_xmit = jiffies; 1281 skb_pull(skb, 2); 1282 #else 1283 /* for data packets, record the time */ 1284 ppp->last_xmit = jiffies; 1285 #endif /* CONFIG_PPP_FILTER */ 1286 } 1287 1288 ++ppp->stats64.tx_packets; 1289 ppp->stats64.tx_bytes += skb->len - 2; 1290 1291 switch (proto) { 1292 case PPP_IP: 1293 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0) 1294 break; 1295 /* try to do VJ TCP header compression */ 1296 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2, 1297 GFP_ATOMIC); 1298 if (!new_skb) { 1299 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n"); 1300 goto drop; 1301 } 1302 skb_reserve(new_skb, ppp->dev->hard_header_len - 2); 1303 cp = skb->data + 2; 1304 len = slhc_compress(ppp->vj, cp, skb->len - 2, 1305 new_skb->data + 2, &cp, 1306 !(ppp->flags & SC_NO_TCP_CCID)); 1307 if (cp == skb->data + 2) { 1308 /* didn't compress */ 1309 consume_skb(new_skb); 1310 } else { 1311 if (cp[0] & SL_TYPE_COMPRESSED_TCP) { 1312 proto = PPP_VJC_COMP; 1313 cp[0] &= ~SL_TYPE_COMPRESSED_TCP; 1314 } else { 1315 proto = PPP_VJC_UNCOMP; 1316 cp[0] = skb->data[2]; 1317 } 1318 consume_skb(skb); 1319 skb = new_skb; 1320 cp = skb_put(skb, len + 2); 1321 cp[0] = 0; 1322 cp[1] = proto; 1323 } 1324 break; 1325 1326 case PPP_CCP: 1327 /* peek at outbound CCP frames */ 1328 ppp_ccp_peek(ppp, skb, 0); 1329 break; 1330 } 1331 1332 /* try to do packet compression */ 1333 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state && 1334 proto != PPP_LCP && proto != PPP_CCP) { 1335 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) { 1336 if (net_ratelimit()) 1337 netdev_err(ppp->dev, 1338 "ppp: compression required but " 1339 "down - pkt dropped.\n"); 1340 goto drop; 1341 } 1342 skb = pad_compress_skb(ppp, skb); 1343 if (!skb) 1344 goto drop; 1345 } 1346 1347 /* 1348 * If we are waiting for traffic (demand dialling), 1349 * queue it up for pppd to receive. 1350 */ 1351 if (ppp->flags & SC_LOOP_TRAFFIC) { 1352 if (ppp->file.rq.qlen > PPP_MAX_RQLEN) 1353 goto drop; 1354 skb_queue_tail(&ppp->file.rq, skb); 1355 wake_up_interruptible(&ppp->file.rwait); 1356 return; 1357 } 1358 1359 ppp->xmit_pending = skb; 1360 ppp_push(ppp); 1361 return; 1362 1363 drop: 1364 kfree_skb(skb); 1365 ++ppp->dev->stats.tx_errors; 1366 } 1367 1368 /* 1369 * Try to send the frame in xmit_pending. 1370 * The caller should have the xmit path locked. 1371 */ 1372 static void 1373 ppp_push(struct ppp *ppp) 1374 { 1375 struct list_head *list; 1376 struct channel *pch; 1377 struct sk_buff *skb = ppp->xmit_pending; 1378 1379 if (!skb) 1380 return; 1381 1382 list = &ppp->channels; 1383 if (list_empty(list)) { 1384 /* nowhere to send the packet, just drop it */ 1385 ppp->xmit_pending = NULL; 1386 kfree_skb(skb); 1387 return; 1388 } 1389 1390 if ((ppp->flags & SC_MULTILINK) == 0) { 1391 /* not doing multilink: send it down the first channel */ 1392 list = list->next; 1393 pch = list_entry(list, struct channel, clist); 1394 1395 spin_lock_bh(&pch->downl); 1396 if (pch->chan) { 1397 if (pch->chan->ops->start_xmit(pch->chan, skb)) 1398 ppp->xmit_pending = NULL; 1399 } else { 1400 /* channel got unregistered */ 1401 kfree_skb(skb); 1402 ppp->xmit_pending = NULL; 1403 } 1404 spin_unlock_bh(&pch->downl); 1405 return; 1406 } 1407 1408 #ifdef CONFIG_PPP_MULTILINK 1409 /* Multilink: fragment the packet over as many links 1410 as can take the packet at the moment. */ 1411 if (!ppp_mp_explode(ppp, skb)) 1412 return; 1413 #endif /* CONFIG_PPP_MULTILINK */ 1414 1415 ppp->xmit_pending = NULL; 1416 kfree_skb(skb); 1417 } 1418 1419 #ifdef CONFIG_PPP_MULTILINK 1420 static bool mp_protocol_compress __read_mostly = true; 1421 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR); 1422 MODULE_PARM_DESC(mp_protocol_compress, 1423 "compress protocol id in multilink fragments"); 1424 1425 /* 1426 * Divide a packet to be transmitted into fragments and 1427 * send them out the individual links. 1428 */ 1429 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb) 1430 { 1431 int len, totlen; 1432 int i, bits, hdrlen, mtu; 1433 int flen; 1434 int navail, nfree, nzero; 1435 int nbigger; 1436 int totspeed; 1437 int totfree; 1438 unsigned char *p, *q; 1439 struct list_head *list; 1440 struct channel *pch; 1441 struct sk_buff *frag; 1442 struct ppp_channel *chan; 1443 1444 totspeed = 0; /*total bitrate of the bundle*/ 1445 nfree = 0; /* # channels which have no packet already queued */ 1446 navail = 0; /* total # of usable channels (not deregistered) */ 1447 nzero = 0; /* number of channels with zero speed associated*/ 1448 totfree = 0; /*total # of channels available and 1449 *having no queued packets before 1450 *starting the fragmentation*/ 1451 1452 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1453 i = 0; 1454 list_for_each_entry(pch, &ppp->channels, clist) { 1455 if (pch->chan) { 1456 pch->avail = 1; 1457 navail++; 1458 pch->speed = pch->chan->speed; 1459 } else { 1460 pch->avail = 0; 1461 } 1462 if (pch->avail) { 1463 if (skb_queue_empty(&pch->file.xq) || 1464 !pch->had_frag) { 1465 if (pch->speed == 0) 1466 nzero++; 1467 else 1468 totspeed += pch->speed; 1469 1470 pch->avail = 2; 1471 ++nfree; 1472 ++totfree; 1473 } 1474 if (!pch->had_frag && i < ppp->nxchan) 1475 ppp->nxchan = i; 1476 } 1477 ++i; 1478 } 1479 /* 1480 * Don't start sending this packet unless at least half of 1481 * the channels are free. This gives much better TCP 1482 * performance if we have a lot of channels. 1483 */ 1484 if (nfree == 0 || nfree < navail / 2) 1485 return 0; /* can't take now, leave it in xmit_pending */ 1486 1487 /* Do protocol field compression */ 1488 p = skb->data; 1489 len = skb->len; 1490 if (*p == 0 && mp_protocol_compress) { 1491 ++p; 1492 --len; 1493 } 1494 1495 totlen = len; 1496 nbigger = len % nfree; 1497 1498 /* skip to the channel after the one we last used 1499 and start at that one */ 1500 list = &ppp->channels; 1501 for (i = 0; i < ppp->nxchan; ++i) { 1502 list = list->next; 1503 if (list == &ppp->channels) { 1504 i = 0; 1505 break; 1506 } 1507 } 1508 1509 /* create a fragment for each channel */ 1510 bits = B; 1511 while (len > 0) { 1512 list = list->next; 1513 if (list == &ppp->channels) { 1514 i = 0; 1515 continue; 1516 } 1517 pch = list_entry(list, struct channel, clist); 1518 ++i; 1519 if (!pch->avail) 1520 continue; 1521 1522 /* 1523 * Skip this channel if it has a fragment pending already and 1524 * we haven't given a fragment to all of the free channels. 1525 */ 1526 if (pch->avail == 1) { 1527 if (nfree > 0) 1528 continue; 1529 } else { 1530 pch->avail = 1; 1531 } 1532 1533 /* check the channel's mtu and whether it is still attached. */ 1534 spin_lock_bh(&pch->downl); 1535 if (pch->chan == NULL) { 1536 /* can't use this channel, it's being deregistered */ 1537 if (pch->speed == 0) 1538 nzero--; 1539 else 1540 totspeed -= pch->speed; 1541 1542 spin_unlock_bh(&pch->downl); 1543 pch->avail = 0; 1544 totlen = len; 1545 totfree--; 1546 nfree--; 1547 if (--navail == 0) 1548 break; 1549 continue; 1550 } 1551 1552 /* 1553 *if the channel speed is not set divide 1554 *the packet evenly among the free channels; 1555 *otherwise divide it according to the speed 1556 *of the channel we are going to transmit on 1557 */ 1558 flen = len; 1559 if (nfree > 0) { 1560 if (pch->speed == 0) { 1561 flen = len/nfree; 1562 if (nbigger > 0) { 1563 flen++; 1564 nbigger--; 1565 } 1566 } else { 1567 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) / 1568 ((totspeed*totfree)/pch->speed)) - hdrlen; 1569 if (nbigger > 0) { 1570 flen += ((totfree - nzero)*pch->speed)/totspeed; 1571 nbigger -= ((totfree - nzero)*pch->speed)/ 1572 totspeed; 1573 } 1574 } 1575 nfree--; 1576 } 1577 1578 /* 1579 *check if we are on the last channel or 1580 *we exceded the length of the data to 1581 *fragment 1582 */ 1583 if ((nfree <= 0) || (flen > len)) 1584 flen = len; 1585 /* 1586 *it is not worth to tx on slow channels: 1587 *in that case from the resulting flen according to the 1588 *above formula will be equal or less than zero. 1589 *Skip the channel in this case 1590 */ 1591 if (flen <= 0) { 1592 pch->avail = 2; 1593 spin_unlock_bh(&pch->downl); 1594 continue; 1595 } 1596 1597 /* 1598 * hdrlen includes the 2-byte PPP protocol field, but the 1599 * MTU counts only the payload excluding the protocol field. 1600 * (RFC1661 Section 2) 1601 */ 1602 mtu = pch->chan->mtu - (hdrlen - 2); 1603 if (mtu < 4) 1604 mtu = 4; 1605 if (flen > mtu) 1606 flen = mtu; 1607 if (flen == len) 1608 bits |= E; 1609 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC); 1610 if (!frag) 1611 goto noskb; 1612 q = skb_put(frag, flen + hdrlen); 1613 1614 /* make the MP header */ 1615 put_unaligned_be16(PPP_MP, q); 1616 if (ppp->flags & SC_MP_XSHORTSEQ) { 1617 q[2] = bits + ((ppp->nxseq >> 8) & 0xf); 1618 q[3] = ppp->nxseq; 1619 } else { 1620 q[2] = bits; 1621 q[3] = ppp->nxseq >> 16; 1622 q[4] = ppp->nxseq >> 8; 1623 q[5] = ppp->nxseq; 1624 } 1625 1626 memcpy(q + hdrlen, p, flen); 1627 1628 /* try to send it down the channel */ 1629 chan = pch->chan; 1630 if (!skb_queue_empty(&pch->file.xq) || 1631 !chan->ops->start_xmit(chan, frag)) 1632 skb_queue_tail(&pch->file.xq, frag); 1633 pch->had_frag = 1; 1634 p += flen; 1635 len -= flen; 1636 ++ppp->nxseq; 1637 bits = 0; 1638 spin_unlock_bh(&pch->downl); 1639 } 1640 ppp->nxchan = i; 1641 1642 return 1; 1643 1644 noskb: 1645 spin_unlock_bh(&pch->downl); 1646 if (ppp->debug & 1) 1647 netdev_err(ppp->dev, "PPP: no memory (fragment)\n"); 1648 ++ppp->dev->stats.tx_errors; 1649 ++ppp->nxseq; 1650 return 1; /* abandon the frame */ 1651 } 1652 #endif /* CONFIG_PPP_MULTILINK */ 1653 1654 /* 1655 * Try to send data out on a channel. 1656 */ 1657 static void 1658 ppp_channel_push(struct channel *pch) 1659 { 1660 struct sk_buff *skb; 1661 struct ppp *ppp; 1662 1663 spin_lock_bh(&pch->downl); 1664 if (pch->chan) { 1665 while (!skb_queue_empty(&pch->file.xq)) { 1666 skb = skb_dequeue(&pch->file.xq); 1667 if (!pch->chan->ops->start_xmit(pch->chan, skb)) { 1668 /* put the packet back and try again later */ 1669 skb_queue_head(&pch->file.xq, skb); 1670 break; 1671 } 1672 } 1673 } else { 1674 /* channel got deregistered */ 1675 skb_queue_purge(&pch->file.xq); 1676 } 1677 spin_unlock_bh(&pch->downl); 1678 /* see if there is anything from the attached unit to be sent */ 1679 if (skb_queue_empty(&pch->file.xq)) { 1680 read_lock_bh(&pch->upl); 1681 ppp = pch->ppp; 1682 if (ppp) 1683 ppp_xmit_process(ppp); 1684 read_unlock_bh(&pch->upl); 1685 } 1686 } 1687 1688 /* 1689 * Receive-side routines. 1690 */ 1691 1692 struct ppp_mp_skb_parm { 1693 u32 sequence; 1694 u8 BEbits; 1695 }; 1696 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb)) 1697 1698 static inline void 1699 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1700 { 1701 ppp_recv_lock(ppp); 1702 if (!ppp->closing) 1703 ppp_receive_frame(ppp, skb, pch); 1704 else 1705 kfree_skb(skb); 1706 ppp_recv_unlock(ppp); 1707 } 1708 1709 void 1710 ppp_input(struct ppp_channel *chan, struct sk_buff *skb) 1711 { 1712 struct channel *pch = chan->ppp; 1713 int proto; 1714 1715 if (!pch) { 1716 kfree_skb(skb); 1717 return; 1718 } 1719 1720 read_lock_bh(&pch->upl); 1721 if (!pskb_may_pull(skb, 2)) { 1722 kfree_skb(skb); 1723 if (pch->ppp) { 1724 ++pch->ppp->dev->stats.rx_length_errors; 1725 ppp_receive_error(pch->ppp); 1726 } 1727 goto done; 1728 } 1729 1730 proto = PPP_PROTO(skb); 1731 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) { 1732 /* put it on the channel queue */ 1733 skb_queue_tail(&pch->file.rq, skb); 1734 /* drop old frames if queue too long */ 1735 while (pch->file.rq.qlen > PPP_MAX_RQLEN && 1736 (skb = skb_dequeue(&pch->file.rq))) 1737 kfree_skb(skb); 1738 wake_up_interruptible(&pch->file.rwait); 1739 } else { 1740 ppp_do_recv(pch->ppp, skb, pch); 1741 } 1742 1743 done: 1744 read_unlock_bh(&pch->upl); 1745 } 1746 1747 /* Put a 0-length skb in the receive queue as an error indication */ 1748 void 1749 ppp_input_error(struct ppp_channel *chan, int code) 1750 { 1751 struct channel *pch = chan->ppp; 1752 struct sk_buff *skb; 1753 1754 if (!pch) 1755 return; 1756 1757 read_lock_bh(&pch->upl); 1758 if (pch->ppp) { 1759 skb = alloc_skb(0, GFP_ATOMIC); 1760 if (skb) { 1761 skb->len = 0; /* probably unnecessary */ 1762 skb->cb[0] = code; 1763 ppp_do_recv(pch->ppp, skb, pch); 1764 } 1765 } 1766 read_unlock_bh(&pch->upl); 1767 } 1768 1769 /* 1770 * We come in here to process a received frame. 1771 * The receive side of the ppp unit is locked. 1772 */ 1773 static void 1774 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1775 { 1776 /* note: a 0-length skb is used as an error indication */ 1777 if (skb->len > 0) { 1778 skb_checksum_complete_unset(skb); 1779 #ifdef CONFIG_PPP_MULTILINK 1780 /* XXX do channel-level decompression here */ 1781 if (PPP_PROTO(skb) == PPP_MP) 1782 ppp_receive_mp_frame(ppp, skb, pch); 1783 else 1784 #endif /* CONFIG_PPP_MULTILINK */ 1785 ppp_receive_nonmp_frame(ppp, skb); 1786 } else { 1787 kfree_skb(skb); 1788 ppp_receive_error(ppp); 1789 } 1790 } 1791 1792 static void 1793 ppp_receive_error(struct ppp *ppp) 1794 { 1795 ++ppp->dev->stats.rx_errors; 1796 if (ppp->vj) 1797 slhc_toss(ppp->vj); 1798 } 1799 1800 static void 1801 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) 1802 { 1803 struct sk_buff *ns; 1804 int proto, len, npi; 1805 1806 /* 1807 * Decompress the frame, if compressed. 1808 * Note that some decompressors need to see uncompressed frames 1809 * that come in as well as compressed frames. 1810 */ 1811 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) && 1812 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0) 1813 skb = ppp_decompress_frame(ppp, skb); 1814 1815 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR) 1816 goto err; 1817 1818 proto = PPP_PROTO(skb); 1819 switch (proto) { 1820 case PPP_VJC_COMP: 1821 /* decompress VJ compressed packets */ 1822 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 1823 goto err; 1824 1825 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) { 1826 /* copy to a new sk_buff with more tailroom */ 1827 ns = dev_alloc_skb(skb->len + 128); 1828 if (!ns) { 1829 netdev_err(ppp->dev, "PPP: no memory " 1830 "(VJ decomp)\n"); 1831 goto err; 1832 } 1833 skb_reserve(ns, 2); 1834 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len); 1835 consume_skb(skb); 1836 skb = ns; 1837 } 1838 else 1839 skb->ip_summed = CHECKSUM_NONE; 1840 1841 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2); 1842 if (len <= 0) { 1843 netdev_printk(KERN_DEBUG, ppp->dev, 1844 "PPP: VJ decompression error\n"); 1845 goto err; 1846 } 1847 len += 2; 1848 if (len > skb->len) 1849 skb_put(skb, len - skb->len); 1850 else if (len < skb->len) 1851 skb_trim(skb, len); 1852 proto = PPP_IP; 1853 break; 1854 1855 case PPP_VJC_UNCOMP: 1856 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 1857 goto err; 1858 1859 /* Until we fix the decompressor need to make sure 1860 * data portion is linear. 1861 */ 1862 if (!pskb_may_pull(skb, skb->len)) 1863 goto err; 1864 1865 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) { 1866 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n"); 1867 goto err; 1868 } 1869 proto = PPP_IP; 1870 break; 1871 1872 case PPP_CCP: 1873 ppp_ccp_peek(ppp, skb, 1); 1874 break; 1875 } 1876 1877 ++ppp->stats64.rx_packets; 1878 ppp->stats64.rx_bytes += skb->len - 2; 1879 1880 npi = proto_to_npindex(proto); 1881 if (npi < 0) { 1882 /* control or unknown frame - pass it to pppd */ 1883 skb_queue_tail(&ppp->file.rq, skb); 1884 /* limit queue length by dropping old frames */ 1885 while (ppp->file.rq.qlen > PPP_MAX_RQLEN && 1886 (skb = skb_dequeue(&ppp->file.rq))) 1887 kfree_skb(skb); 1888 /* wake up any process polling or blocking on read */ 1889 wake_up_interruptible(&ppp->file.rwait); 1890 1891 } else { 1892 /* network protocol frame - give it to the kernel */ 1893 1894 #ifdef CONFIG_PPP_FILTER 1895 /* check if the packet passes the pass and active filters */ 1896 /* the filter instructions are constructed assuming 1897 a four-byte PPP header on each packet */ 1898 if (ppp->pass_filter || ppp->active_filter) { 1899 if (skb_unclone(skb, GFP_ATOMIC)) 1900 goto err; 1901 1902 *skb_push(skb, 2) = 0; 1903 if (ppp->pass_filter && 1904 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 1905 if (ppp->debug & 1) 1906 netdev_printk(KERN_DEBUG, ppp->dev, 1907 "PPP: inbound frame " 1908 "not passed\n"); 1909 kfree_skb(skb); 1910 return; 1911 } 1912 if (!(ppp->active_filter && 1913 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 1914 ppp->last_recv = jiffies; 1915 __skb_pull(skb, 2); 1916 } else 1917 #endif /* CONFIG_PPP_FILTER */ 1918 ppp->last_recv = jiffies; 1919 1920 if ((ppp->dev->flags & IFF_UP) == 0 || 1921 ppp->npmode[npi] != NPMODE_PASS) { 1922 kfree_skb(skb); 1923 } else { 1924 /* chop off protocol */ 1925 skb_pull_rcsum(skb, 2); 1926 skb->dev = ppp->dev; 1927 skb->protocol = htons(npindex_to_ethertype[npi]); 1928 skb_reset_mac_header(skb); 1929 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, 1930 dev_net(ppp->dev))); 1931 netif_rx(skb); 1932 } 1933 } 1934 return; 1935 1936 err: 1937 kfree_skb(skb); 1938 ppp_receive_error(ppp); 1939 } 1940 1941 static struct sk_buff * 1942 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb) 1943 { 1944 int proto = PPP_PROTO(skb); 1945 struct sk_buff *ns; 1946 int len; 1947 1948 /* Until we fix all the decompressor's need to make sure 1949 * data portion is linear. 1950 */ 1951 if (!pskb_may_pull(skb, skb->len)) 1952 goto err; 1953 1954 if (proto == PPP_COMP) { 1955 int obuff_size; 1956 1957 switch(ppp->rcomp->compress_proto) { 1958 case CI_MPPE: 1959 obuff_size = ppp->mru + PPP_HDRLEN + 1; 1960 break; 1961 default: 1962 obuff_size = ppp->mru + PPP_HDRLEN; 1963 break; 1964 } 1965 1966 ns = dev_alloc_skb(obuff_size); 1967 if (!ns) { 1968 netdev_err(ppp->dev, "ppp_decompress_frame: " 1969 "no memory\n"); 1970 goto err; 1971 } 1972 /* the decompressor still expects the A/C bytes in the hdr */ 1973 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2, 1974 skb->len + 2, ns->data, obuff_size); 1975 if (len < 0) { 1976 /* Pass the compressed frame to pppd as an 1977 error indication. */ 1978 if (len == DECOMP_FATALERROR) 1979 ppp->rstate |= SC_DC_FERROR; 1980 kfree_skb(ns); 1981 goto err; 1982 } 1983 1984 consume_skb(skb); 1985 skb = ns; 1986 skb_put(skb, len); 1987 skb_pull(skb, 2); /* pull off the A/C bytes */ 1988 1989 } else { 1990 /* Uncompressed frame - pass to decompressor so it 1991 can update its dictionary if necessary. */ 1992 if (ppp->rcomp->incomp) 1993 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2, 1994 skb->len + 2); 1995 } 1996 1997 return skb; 1998 1999 err: 2000 ppp->rstate |= SC_DC_ERROR; 2001 ppp_receive_error(ppp); 2002 return skb; 2003 } 2004 2005 #ifdef CONFIG_PPP_MULTILINK 2006 /* 2007 * Receive a multilink frame. 2008 * We put it on the reconstruction queue and then pull off 2009 * as many completed frames as we can. 2010 */ 2011 static void 2012 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2013 { 2014 u32 mask, seq; 2015 struct channel *ch; 2016 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 2017 2018 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0) 2019 goto err; /* no good, throw it away */ 2020 2021 /* Decode sequence number and begin/end bits */ 2022 if (ppp->flags & SC_MP_SHORTSEQ) { 2023 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3]; 2024 mask = 0xfff; 2025 } else { 2026 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5]; 2027 mask = 0xffffff; 2028 } 2029 PPP_MP_CB(skb)->BEbits = skb->data[2]; 2030 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */ 2031 2032 /* 2033 * Do protocol ID decompression on the first fragment of each packet. 2034 */ 2035 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1)) 2036 *skb_push(skb, 1) = 0; 2037 2038 /* 2039 * Expand sequence number to 32 bits, making it as close 2040 * as possible to ppp->minseq. 2041 */ 2042 seq |= ppp->minseq & ~mask; 2043 if ((int)(ppp->minseq - seq) > (int)(mask >> 1)) 2044 seq += mask + 1; 2045 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1)) 2046 seq -= mask + 1; /* should never happen */ 2047 PPP_MP_CB(skb)->sequence = seq; 2048 pch->lastseq = seq; 2049 2050 /* 2051 * If this packet comes before the next one we were expecting, 2052 * drop it. 2053 */ 2054 if (seq_before(seq, ppp->nextseq)) { 2055 kfree_skb(skb); 2056 ++ppp->dev->stats.rx_dropped; 2057 ppp_receive_error(ppp); 2058 return; 2059 } 2060 2061 /* 2062 * Reevaluate minseq, the minimum over all channels of the 2063 * last sequence number received on each channel. Because of 2064 * the increasing sequence number rule, we know that any fragment 2065 * before `minseq' which hasn't arrived is never going to arrive. 2066 * The list of channels can't change because we have the receive 2067 * side of the ppp unit locked. 2068 */ 2069 list_for_each_entry(ch, &ppp->channels, clist) { 2070 if (seq_before(ch->lastseq, seq)) 2071 seq = ch->lastseq; 2072 } 2073 if (seq_before(ppp->minseq, seq)) 2074 ppp->minseq = seq; 2075 2076 /* Put the fragment on the reconstruction queue */ 2077 ppp_mp_insert(ppp, skb); 2078 2079 /* If the queue is getting long, don't wait any longer for packets 2080 before the start of the queue. */ 2081 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) { 2082 struct sk_buff *mskb = skb_peek(&ppp->mrq); 2083 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence)) 2084 ppp->minseq = PPP_MP_CB(mskb)->sequence; 2085 } 2086 2087 /* Pull completed packets off the queue and receive them. */ 2088 while ((skb = ppp_mp_reconstruct(ppp))) { 2089 if (pskb_may_pull(skb, 2)) 2090 ppp_receive_nonmp_frame(ppp, skb); 2091 else { 2092 ++ppp->dev->stats.rx_length_errors; 2093 kfree_skb(skb); 2094 ppp_receive_error(ppp); 2095 } 2096 } 2097 2098 return; 2099 2100 err: 2101 kfree_skb(skb); 2102 ppp_receive_error(ppp); 2103 } 2104 2105 /* 2106 * Insert a fragment on the MP reconstruction queue. 2107 * The queue is ordered by increasing sequence number. 2108 */ 2109 static void 2110 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb) 2111 { 2112 struct sk_buff *p; 2113 struct sk_buff_head *list = &ppp->mrq; 2114 u32 seq = PPP_MP_CB(skb)->sequence; 2115 2116 /* N.B. we don't need to lock the list lock because we have the 2117 ppp unit receive-side lock. */ 2118 skb_queue_walk(list, p) { 2119 if (seq_before(seq, PPP_MP_CB(p)->sequence)) 2120 break; 2121 } 2122 __skb_queue_before(list, p, skb); 2123 } 2124 2125 /* 2126 * Reconstruct a packet from the MP fragment queue. 2127 * We go through increasing sequence numbers until we find a 2128 * complete packet, or we get to the sequence number for a fragment 2129 * which hasn't arrived but might still do so. 2130 */ 2131 static struct sk_buff * 2132 ppp_mp_reconstruct(struct ppp *ppp) 2133 { 2134 u32 seq = ppp->nextseq; 2135 u32 minseq = ppp->minseq; 2136 struct sk_buff_head *list = &ppp->mrq; 2137 struct sk_buff *p, *tmp; 2138 struct sk_buff *head, *tail; 2139 struct sk_buff *skb = NULL; 2140 int lost = 0, len = 0; 2141 2142 if (ppp->mrru == 0) /* do nothing until mrru is set */ 2143 return NULL; 2144 head = list->next; 2145 tail = NULL; 2146 skb_queue_walk_safe(list, p, tmp) { 2147 again: 2148 if (seq_before(PPP_MP_CB(p)->sequence, seq)) { 2149 /* this can't happen, anyway ignore the skb */ 2150 netdev_err(ppp->dev, "ppp_mp_reconstruct bad " 2151 "seq %u < %u\n", 2152 PPP_MP_CB(p)->sequence, seq); 2153 __skb_unlink(p, list); 2154 kfree_skb(p); 2155 continue; 2156 } 2157 if (PPP_MP_CB(p)->sequence != seq) { 2158 u32 oldseq; 2159 /* Fragment `seq' is missing. If it is after 2160 minseq, it might arrive later, so stop here. */ 2161 if (seq_after(seq, minseq)) 2162 break; 2163 /* Fragment `seq' is lost, keep going. */ 2164 lost = 1; 2165 oldseq = seq; 2166 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)? 2167 minseq + 1: PPP_MP_CB(p)->sequence; 2168 2169 if (ppp->debug & 1) 2170 netdev_printk(KERN_DEBUG, ppp->dev, 2171 "lost frag %u..%u\n", 2172 oldseq, seq-1); 2173 2174 goto again; 2175 } 2176 2177 /* 2178 * At this point we know that all the fragments from 2179 * ppp->nextseq to seq are either present or lost. 2180 * Also, there are no complete packets in the queue 2181 * that have no missing fragments and end before this 2182 * fragment. 2183 */ 2184 2185 /* B bit set indicates this fragment starts a packet */ 2186 if (PPP_MP_CB(p)->BEbits & B) { 2187 head = p; 2188 lost = 0; 2189 len = 0; 2190 } 2191 2192 len += p->len; 2193 2194 /* Got a complete packet yet? */ 2195 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) && 2196 (PPP_MP_CB(head)->BEbits & B)) { 2197 if (len > ppp->mrru + 2) { 2198 ++ppp->dev->stats.rx_length_errors; 2199 netdev_printk(KERN_DEBUG, ppp->dev, 2200 "PPP: reconstructed packet" 2201 " is too long (%d)\n", len); 2202 } else { 2203 tail = p; 2204 break; 2205 } 2206 ppp->nextseq = seq + 1; 2207 } 2208 2209 /* 2210 * If this is the ending fragment of a packet, 2211 * and we haven't found a complete valid packet yet, 2212 * we can discard up to and including this fragment. 2213 */ 2214 if (PPP_MP_CB(p)->BEbits & E) { 2215 struct sk_buff *tmp2; 2216 2217 skb_queue_reverse_walk_from_safe(list, p, tmp2) { 2218 if (ppp->debug & 1) 2219 netdev_printk(KERN_DEBUG, ppp->dev, 2220 "discarding frag %u\n", 2221 PPP_MP_CB(p)->sequence); 2222 __skb_unlink(p, list); 2223 kfree_skb(p); 2224 } 2225 head = skb_peek(list); 2226 if (!head) 2227 break; 2228 } 2229 ++seq; 2230 } 2231 2232 /* If we have a complete packet, copy it all into one skb. */ 2233 if (tail != NULL) { 2234 /* If we have discarded any fragments, 2235 signal a receive error. */ 2236 if (PPP_MP_CB(head)->sequence != ppp->nextseq) { 2237 skb_queue_walk_safe(list, p, tmp) { 2238 if (p == head) 2239 break; 2240 if (ppp->debug & 1) 2241 netdev_printk(KERN_DEBUG, ppp->dev, 2242 "discarding frag %u\n", 2243 PPP_MP_CB(p)->sequence); 2244 __skb_unlink(p, list); 2245 kfree_skb(p); 2246 } 2247 2248 if (ppp->debug & 1) 2249 netdev_printk(KERN_DEBUG, ppp->dev, 2250 " missed pkts %u..%u\n", 2251 ppp->nextseq, 2252 PPP_MP_CB(head)->sequence-1); 2253 ++ppp->dev->stats.rx_dropped; 2254 ppp_receive_error(ppp); 2255 } 2256 2257 skb = head; 2258 if (head != tail) { 2259 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list; 2260 p = skb_queue_next(list, head); 2261 __skb_unlink(skb, list); 2262 skb_queue_walk_from_safe(list, p, tmp) { 2263 __skb_unlink(p, list); 2264 *fragpp = p; 2265 p->next = NULL; 2266 fragpp = &p->next; 2267 2268 skb->len += p->len; 2269 skb->data_len += p->len; 2270 skb->truesize += p->truesize; 2271 2272 if (p == tail) 2273 break; 2274 } 2275 } else { 2276 __skb_unlink(skb, list); 2277 } 2278 2279 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1; 2280 } 2281 2282 return skb; 2283 } 2284 #endif /* CONFIG_PPP_MULTILINK */ 2285 2286 /* 2287 * Channel interface. 2288 */ 2289 2290 /* Create a new, unattached ppp channel. */ 2291 int ppp_register_channel(struct ppp_channel *chan) 2292 { 2293 return ppp_register_net_channel(current->nsproxy->net_ns, chan); 2294 } 2295 2296 /* Create a new, unattached ppp channel for specified net. */ 2297 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan) 2298 { 2299 struct channel *pch; 2300 struct ppp_net *pn; 2301 2302 pch = kzalloc(sizeof(struct channel), GFP_KERNEL); 2303 if (!pch) 2304 return -ENOMEM; 2305 2306 pn = ppp_pernet(net); 2307 2308 pch->ppp = NULL; 2309 pch->chan = chan; 2310 pch->chan_net = get_net(net); 2311 chan->ppp = pch; 2312 init_ppp_file(&pch->file, CHANNEL); 2313 pch->file.hdrlen = chan->hdrlen; 2314 #ifdef CONFIG_PPP_MULTILINK 2315 pch->lastseq = -1; 2316 #endif /* CONFIG_PPP_MULTILINK */ 2317 init_rwsem(&pch->chan_sem); 2318 spin_lock_init(&pch->downl); 2319 rwlock_init(&pch->upl); 2320 2321 spin_lock_bh(&pn->all_channels_lock); 2322 pch->file.index = ++pn->last_channel_index; 2323 list_add(&pch->list, &pn->new_channels); 2324 atomic_inc(&channel_count); 2325 spin_unlock_bh(&pn->all_channels_lock); 2326 2327 return 0; 2328 } 2329 2330 /* 2331 * Return the index of a channel. 2332 */ 2333 int ppp_channel_index(struct ppp_channel *chan) 2334 { 2335 struct channel *pch = chan->ppp; 2336 2337 if (pch) 2338 return pch->file.index; 2339 return -1; 2340 } 2341 2342 /* 2343 * Return the PPP unit number to which a channel is connected. 2344 */ 2345 int ppp_unit_number(struct ppp_channel *chan) 2346 { 2347 struct channel *pch = chan->ppp; 2348 int unit = -1; 2349 2350 if (pch) { 2351 read_lock_bh(&pch->upl); 2352 if (pch->ppp) 2353 unit = pch->ppp->file.index; 2354 read_unlock_bh(&pch->upl); 2355 } 2356 return unit; 2357 } 2358 2359 /* 2360 * Return the PPP device interface name of a channel. 2361 */ 2362 char *ppp_dev_name(struct ppp_channel *chan) 2363 { 2364 struct channel *pch = chan->ppp; 2365 char *name = NULL; 2366 2367 if (pch) { 2368 read_lock_bh(&pch->upl); 2369 if (pch->ppp && pch->ppp->dev) 2370 name = pch->ppp->dev->name; 2371 read_unlock_bh(&pch->upl); 2372 } 2373 return name; 2374 } 2375 2376 2377 /* 2378 * Disconnect a channel from the generic layer. 2379 * This must be called in process context. 2380 */ 2381 void 2382 ppp_unregister_channel(struct ppp_channel *chan) 2383 { 2384 struct channel *pch = chan->ppp; 2385 struct ppp_net *pn; 2386 2387 if (!pch) 2388 return; /* should never happen */ 2389 2390 chan->ppp = NULL; 2391 2392 /* 2393 * This ensures that we have returned from any calls into the 2394 * the channel's start_xmit or ioctl routine before we proceed. 2395 */ 2396 down_write(&pch->chan_sem); 2397 spin_lock_bh(&pch->downl); 2398 pch->chan = NULL; 2399 spin_unlock_bh(&pch->downl); 2400 up_write(&pch->chan_sem); 2401 ppp_disconnect_channel(pch); 2402 2403 pn = ppp_pernet(pch->chan_net); 2404 spin_lock_bh(&pn->all_channels_lock); 2405 list_del(&pch->list); 2406 spin_unlock_bh(&pn->all_channels_lock); 2407 put_net(pch->chan_net); 2408 pch->chan_net = NULL; 2409 2410 pch->file.dead = 1; 2411 wake_up_interruptible(&pch->file.rwait); 2412 if (atomic_dec_and_test(&pch->file.refcnt)) 2413 ppp_destroy_channel(pch); 2414 } 2415 2416 /* 2417 * Callback from a channel when it can accept more to transmit. 2418 * This should be called at BH/softirq level, not interrupt level. 2419 */ 2420 void 2421 ppp_output_wakeup(struct ppp_channel *chan) 2422 { 2423 struct channel *pch = chan->ppp; 2424 2425 if (!pch) 2426 return; 2427 ppp_channel_push(pch); 2428 } 2429 2430 /* 2431 * Compression control. 2432 */ 2433 2434 /* Process the PPPIOCSCOMPRESS ioctl. */ 2435 static int 2436 ppp_set_compress(struct ppp *ppp, unsigned long arg) 2437 { 2438 int err; 2439 struct compressor *cp, *ocomp; 2440 struct ppp_option_data data; 2441 void *state, *ostate; 2442 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH]; 2443 2444 err = -EFAULT; 2445 if (copy_from_user(&data, (void __user *) arg, sizeof(data))) 2446 goto out; 2447 if (data.length > CCP_MAX_OPTION_LENGTH) 2448 goto out; 2449 if (copy_from_user(ccp_option, (void __user *) data.ptr, data.length)) 2450 goto out; 2451 2452 err = -EINVAL; 2453 if (data.length < 2 || ccp_option[1] < 2 || ccp_option[1] > data.length) 2454 goto out; 2455 2456 cp = try_then_request_module( 2457 find_compressor(ccp_option[0]), 2458 "ppp-compress-%d", ccp_option[0]); 2459 if (!cp) 2460 goto out; 2461 2462 err = -ENOBUFS; 2463 if (data.transmit) { 2464 state = cp->comp_alloc(ccp_option, data.length); 2465 if (state) { 2466 ppp_xmit_lock(ppp); 2467 ppp->xstate &= ~SC_COMP_RUN; 2468 ocomp = ppp->xcomp; 2469 ostate = ppp->xc_state; 2470 ppp->xcomp = cp; 2471 ppp->xc_state = state; 2472 ppp_xmit_unlock(ppp); 2473 if (ostate) { 2474 ocomp->comp_free(ostate); 2475 module_put(ocomp->owner); 2476 } 2477 err = 0; 2478 } else 2479 module_put(cp->owner); 2480 2481 } else { 2482 state = cp->decomp_alloc(ccp_option, data.length); 2483 if (state) { 2484 ppp_recv_lock(ppp); 2485 ppp->rstate &= ~SC_DECOMP_RUN; 2486 ocomp = ppp->rcomp; 2487 ostate = ppp->rc_state; 2488 ppp->rcomp = cp; 2489 ppp->rc_state = state; 2490 ppp_recv_unlock(ppp); 2491 if (ostate) { 2492 ocomp->decomp_free(ostate); 2493 module_put(ocomp->owner); 2494 } 2495 err = 0; 2496 } else 2497 module_put(cp->owner); 2498 } 2499 2500 out: 2501 return err; 2502 } 2503 2504 /* 2505 * Look at a CCP packet and update our state accordingly. 2506 * We assume the caller has the xmit or recv path locked. 2507 */ 2508 static void 2509 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound) 2510 { 2511 unsigned char *dp; 2512 int len; 2513 2514 if (!pskb_may_pull(skb, CCP_HDRLEN + 2)) 2515 return; /* no header */ 2516 dp = skb->data + 2; 2517 2518 switch (CCP_CODE(dp)) { 2519 case CCP_CONFREQ: 2520 2521 /* A ConfReq starts negotiation of compression 2522 * in one direction of transmission, 2523 * and hence brings it down...but which way? 2524 * 2525 * Remember: 2526 * A ConfReq indicates what the sender would like to receive 2527 */ 2528 if(inbound) 2529 /* He is proposing what I should send */ 2530 ppp->xstate &= ~SC_COMP_RUN; 2531 else 2532 /* I am proposing to what he should send */ 2533 ppp->rstate &= ~SC_DECOMP_RUN; 2534 2535 break; 2536 2537 case CCP_TERMREQ: 2538 case CCP_TERMACK: 2539 /* 2540 * CCP is going down, both directions of transmission 2541 */ 2542 ppp->rstate &= ~SC_DECOMP_RUN; 2543 ppp->xstate &= ~SC_COMP_RUN; 2544 break; 2545 2546 case CCP_CONFACK: 2547 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN) 2548 break; 2549 len = CCP_LENGTH(dp); 2550 if (!pskb_may_pull(skb, len + 2)) 2551 return; /* too short */ 2552 dp += CCP_HDRLEN; 2553 len -= CCP_HDRLEN; 2554 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp)) 2555 break; 2556 if (inbound) { 2557 /* we will start receiving compressed packets */ 2558 if (!ppp->rc_state) 2559 break; 2560 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len, 2561 ppp->file.index, 0, ppp->mru, ppp->debug)) { 2562 ppp->rstate |= SC_DECOMP_RUN; 2563 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR); 2564 } 2565 } else { 2566 /* we will soon start sending compressed packets */ 2567 if (!ppp->xc_state) 2568 break; 2569 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len, 2570 ppp->file.index, 0, ppp->debug)) 2571 ppp->xstate |= SC_COMP_RUN; 2572 } 2573 break; 2574 2575 case CCP_RESETACK: 2576 /* reset the [de]compressor */ 2577 if ((ppp->flags & SC_CCP_UP) == 0) 2578 break; 2579 if (inbound) { 2580 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) { 2581 ppp->rcomp->decomp_reset(ppp->rc_state); 2582 ppp->rstate &= ~SC_DC_ERROR; 2583 } 2584 } else { 2585 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN)) 2586 ppp->xcomp->comp_reset(ppp->xc_state); 2587 } 2588 break; 2589 } 2590 } 2591 2592 /* Free up compression resources. */ 2593 static void 2594 ppp_ccp_closed(struct ppp *ppp) 2595 { 2596 void *xstate, *rstate; 2597 struct compressor *xcomp, *rcomp; 2598 2599 ppp_lock(ppp); 2600 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP); 2601 ppp->xstate = 0; 2602 xcomp = ppp->xcomp; 2603 xstate = ppp->xc_state; 2604 ppp->xc_state = NULL; 2605 ppp->rstate = 0; 2606 rcomp = ppp->rcomp; 2607 rstate = ppp->rc_state; 2608 ppp->rc_state = NULL; 2609 ppp_unlock(ppp); 2610 2611 if (xstate) { 2612 xcomp->comp_free(xstate); 2613 module_put(xcomp->owner); 2614 } 2615 if (rstate) { 2616 rcomp->decomp_free(rstate); 2617 module_put(rcomp->owner); 2618 } 2619 } 2620 2621 /* List of compressors. */ 2622 static LIST_HEAD(compressor_list); 2623 static DEFINE_SPINLOCK(compressor_list_lock); 2624 2625 struct compressor_entry { 2626 struct list_head list; 2627 struct compressor *comp; 2628 }; 2629 2630 static struct compressor_entry * 2631 find_comp_entry(int proto) 2632 { 2633 struct compressor_entry *ce; 2634 2635 list_for_each_entry(ce, &compressor_list, list) { 2636 if (ce->comp->compress_proto == proto) 2637 return ce; 2638 } 2639 return NULL; 2640 } 2641 2642 /* Register a compressor */ 2643 int 2644 ppp_register_compressor(struct compressor *cp) 2645 { 2646 struct compressor_entry *ce; 2647 int ret; 2648 spin_lock(&compressor_list_lock); 2649 ret = -EEXIST; 2650 if (find_comp_entry(cp->compress_proto)) 2651 goto out; 2652 ret = -ENOMEM; 2653 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC); 2654 if (!ce) 2655 goto out; 2656 ret = 0; 2657 ce->comp = cp; 2658 list_add(&ce->list, &compressor_list); 2659 out: 2660 spin_unlock(&compressor_list_lock); 2661 return ret; 2662 } 2663 2664 /* Unregister a compressor */ 2665 void 2666 ppp_unregister_compressor(struct compressor *cp) 2667 { 2668 struct compressor_entry *ce; 2669 2670 spin_lock(&compressor_list_lock); 2671 ce = find_comp_entry(cp->compress_proto); 2672 if (ce && ce->comp == cp) { 2673 list_del(&ce->list); 2674 kfree(ce); 2675 } 2676 spin_unlock(&compressor_list_lock); 2677 } 2678 2679 /* Find a compressor. */ 2680 static struct compressor * 2681 find_compressor(int type) 2682 { 2683 struct compressor_entry *ce; 2684 struct compressor *cp = NULL; 2685 2686 spin_lock(&compressor_list_lock); 2687 ce = find_comp_entry(type); 2688 if (ce) { 2689 cp = ce->comp; 2690 if (!try_module_get(cp->owner)) 2691 cp = NULL; 2692 } 2693 spin_unlock(&compressor_list_lock); 2694 return cp; 2695 } 2696 2697 /* 2698 * Miscelleneous stuff. 2699 */ 2700 2701 static void 2702 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st) 2703 { 2704 struct slcompress *vj = ppp->vj; 2705 2706 memset(st, 0, sizeof(*st)); 2707 st->p.ppp_ipackets = ppp->stats64.rx_packets; 2708 st->p.ppp_ierrors = ppp->dev->stats.rx_errors; 2709 st->p.ppp_ibytes = ppp->stats64.rx_bytes; 2710 st->p.ppp_opackets = ppp->stats64.tx_packets; 2711 st->p.ppp_oerrors = ppp->dev->stats.tx_errors; 2712 st->p.ppp_obytes = ppp->stats64.tx_bytes; 2713 if (!vj) 2714 return; 2715 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed; 2716 st->vj.vjs_compressed = vj->sls_o_compressed; 2717 st->vj.vjs_searches = vj->sls_o_searches; 2718 st->vj.vjs_misses = vj->sls_o_misses; 2719 st->vj.vjs_errorin = vj->sls_i_error; 2720 st->vj.vjs_tossed = vj->sls_i_tossed; 2721 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed; 2722 st->vj.vjs_compressedin = vj->sls_i_compressed; 2723 } 2724 2725 /* 2726 * Stuff for handling the lists of ppp units and channels 2727 * and for initialization. 2728 */ 2729 2730 /* 2731 * Create a new ppp interface unit. Fails if it can't allocate memory 2732 * or if there is already a unit with the requested number. 2733 * unit == -1 means allocate a new number. 2734 */ 2735 static struct ppp *ppp_create_interface(struct net *net, int unit, 2736 struct file *file, int *retp) 2737 { 2738 struct ppp *ppp; 2739 struct ppp_net *pn; 2740 struct net_device *dev = NULL; 2741 int ret = -ENOMEM; 2742 int i; 2743 2744 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup); 2745 if (!dev) 2746 goto out1; 2747 2748 pn = ppp_pernet(net); 2749 2750 ppp = netdev_priv(dev); 2751 ppp->dev = dev; 2752 ppp->mru = PPP_MRU; 2753 init_ppp_file(&ppp->file, INTERFACE); 2754 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */ 2755 ppp->owner = file; 2756 for (i = 0; i < NUM_NP; ++i) 2757 ppp->npmode[i] = NPMODE_PASS; 2758 INIT_LIST_HEAD(&ppp->channels); 2759 spin_lock_init(&ppp->rlock); 2760 spin_lock_init(&ppp->wlock); 2761 #ifdef CONFIG_PPP_MULTILINK 2762 ppp->minseq = -1; 2763 skb_queue_head_init(&ppp->mrq); 2764 #endif /* CONFIG_PPP_MULTILINK */ 2765 #ifdef CONFIG_PPP_FILTER 2766 ppp->pass_filter = NULL; 2767 ppp->active_filter = NULL; 2768 #endif /* CONFIG_PPP_FILTER */ 2769 2770 /* 2771 * drum roll: don't forget to set 2772 * the net device is belong to 2773 */ 2774 dev_net_set(dev, net); 2775 2776 rtnl_lock(); 2777 mutex_lock(&pn->all_ppp_mutex); 2778 2779 if (unit < 0) { 2780 unit = unit_get(&pn->units_idr, ppp); 2781 if (unit < 0) { 2782 ret = unit; 2783 goto out2; 2784 } 2785 } else { 2786 ret = -EEXIST; 2787 if (unit_find(&pn->units_idr, unit)) 2788 goto out2; /* unit already exists */ 2789 /* 2790 * if caller need a specified unit number 2791 * lets try to satisfy him, otherwise -- 2792 * he should better ask us for new unit number 2793 * 2794 * NOTE: yes I know that returning EEXIST it's not 2795 * fair but at least pppd will ask us to allocate 2796 * new unit in this case so user is happy :) 2797 */ 2798 unit = unit_set(&pn->units_idr, ppp, unit); 2799 if (unit < 0) 2800 goto out2; 2801 } 2802 2803 /* Initialize the new ppp unit */ 2804 ppp->file.index = unit; 2805 sprintf(dev->name, "ppp%d", unit); 2806 2807 ret = register_netdevice(dev); 2808 if (ret != 0) { 2809 unit_put(&pn->units_idr, unit); 2810 netdev_err(ppp->dev, "PPP: couldn't register device %s (%d)\n", 2811 dev->name, ret); 2812 goto out2; 2813 } 2814 2815 ppp->ppp_net = net; 2816 2817 atomic_inc(&ppp_unit_count); 2818 mutex_unlock(&pn->all_ppp_mutex); 2819 rtnl_unlock(); 2820 2821 *retp = 0; 2822 return ppp; 2823 2824 out2: 2825 mutex_unlock(&pn->all_ppp_mutex); 2826 rtnl_unlock(); 2827 free_netdev(dev); 2828 out1: 2829 *retp = ret; 2830 return NULL; 2831 } 2832 2833 /* 2834 * Initialize a ppp_file structure. 2835 */ 2836 static void 2837 init_ppp_file(struct ppp_file *pf, int kind) 2838 { 2839 pf->kind = kind; 2840 skb_queue_head_init(&pf->xq); 2841 skb_queue_head_init(&pf->rq); 2842 atomic_set(&pf->refcnt, 1); 2843 init_waitqueue_head(&pf->rwait); 2844 } 2845 2846 /* 2847 * Free the memory used by a ppp unit. This is only called once 2848 * there are no channels connected to the unit and no file structs 2849 * that reference the unit. 2850 */ 2851 static void ppp_destroy_interface(struct ppp *ppp) 2852 { 2853 atomic_dec(&ppp_unit_count); 2854 2855 if (!ppp->file.dead || ppp->n_channels) { 2856 /* "can't happen" */ 2857 netdev_err(ppp->dev, "ppp: destroying ppp struct %p " 2858 "but dead=%d n_channels=%d !\n", 2859 ppp, ppp->file.dead, ppp->n_channels); 2860 return; 2861 } 2862 2863 ppp_ccp_closed(ppp); 2864 if (ppp->vj) { 2865 slhc_free(ppp->vj); 2866 ppp->vj = NULL; 2867 } 2868 skb_queue_purge(&ppp->file.xq); 2869 skb_queue_purge(&ppp->file.rq); 2870 #ifdef CONFIG_PPP_MULTILINK 2871 skb_queue_purge(&ppp->mrq); 2872 #endif /* CONFIG_PPP_MULTILINK */ 2873 #ifdef CONFIG_PPP_FILTER 2874 if (ppp->pass_filter) { 2875 bpf_prog_destroy(ppp->pass_filter); 2876 ppp->pass_filter = NULL; 2877 } 2878 2879 if (ppp->active_filter) { 2880 bpf_prog_destroy(ppp->active_filter); 2881 ppp->active_filter = NULL; 2882 } 2883 #endif /* CONFIG_PPP_FILTER */ 2884 2885 kfree_skb(ppp->xmit_pending); 2886 2887 free_netdev(ppp->dev); 2888 } 2889 2890 /* 2891 * Locate an existing ppp unit. 2892 * The caller should have locked the all_ppp_mutex. 2893 */ 2894 static struct ppp * 2895 ppp_find_unit(struct ppp_net *pn, int unit) 2896 { 2897 return unit_find(&pn->units_idr, unit); 2898 } 2899 2900 /* 2901 * Locate an existing ppp channel. 2902 * The caller should have locked the all_channels_lock. 2903 * First we look in the new_channels list, then in the 2904 * all_channels list. If found in the new_channels list, 2905 * we move it to the all_channels list. This is for speed 2906 * when we have a lot of channels in use. 2907 */ 2908 static struct channel * 2909 ppp_find_channel(struct ppp_net *pn, int unit) 2910 { 2911 struct channel *pch; 2912 2913 list_for_each_entry(pch, &pn->new_channels, list) { 2914 if (pch->file.index == unit) { 2915 list_move(&pch->list, &pn->all_channels); 2916 return pch; 2917 } 2918 } 2919 2920 list_for_each_entry(pch, &pn->all_channels, list) { 2921 if (pch->file.index == unit) 2922 return pch; 2923 } 2924 2925 return NULL; 2926 } 2927 2928 /* 2929 * Connect a PPP channel to a PPP interface unit. 2930 */ 2931 static int 2932 ppp_connect_channel(struct channel *pch, int unit) 2933 { 2934 struct ppp *ppp; 2935 struct ppp_net *pn; 2936 int ret = -ENXIO; 2937 int hdrlen; 2938 2939 pn = ppp_pernet(pch->chan_net); 2940 2941 mutex_lock(&pn->all_ppp_mutex); 2942 ppp = ppp_find_unit(pn, unit); 2943 if (!ppp) 2944 goto out; 2945 write_lock_bh(&pch->upl); 2946 ret = -EINVAL; 2947 if (pch->ppp) 2948 goto outl; 2949 2950 ppp_lock(ppp); 2951 if (pch->file.hdrlen > ppp->file.hdrlen) 2952 ppp->file.hdrlen = pch->file.hdrlen; 2953 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */ 2954 if (hdrlen > ppp->dev->hard_header_len) 2955 ppp->dev->hard_header_len = hdrlen; 2956 list_add_tail(&pch->clist, &ppp->channels); 2957 ++ppp->n_channels; 2958 pch->ppp = ppp; 2959 atomic_inc(&ppp->file.refcnt); 2960 ppp_unlock(ppp); 2961 ret = 0; 2962 2963 outl: 2964 write_unlock_bh(&pch->upl); 2965 out: 2966 mutex_unlock(&pn->all_ppp_mutex); 2967 return ret; 2968 } 2969 2970 /* 2971 * Disconnect a channel from its ppp unit. 2972 */ 2973 static int 2974 ppp_disconnect_channel(struct channel *pch) 2975 { 2976 struct ppp *ppp; 2977 int err = -EINVAL; 2978 2979 write_lock_bh(&pch->upl); 2980 ppp = pch->ppp; 2981 pch->ppp = NULL; 2982 write_unlock_bh(&pch->upl); 2983 if (ppp) { 2984 /* remove it from the ppp unit's list */ 2985 ppp_lock(ppp); 2986 list_del(&pch->clist); 2987 if (--ppp->n_channels == 0) 2988 wake_up_interruptible(&ppp->file.rwait); 2989 ppp_unlock(ppp); 2990 if (atomic_dec_and_test(&ppp->file.refcnt)) 2991 ppp_destroy_interface(ppp); 2992 err = 0; 2993 } 2994 return err; 2995 } 2996 2997 /* 2998 * Free up the resources used by a ppp channel. 2999 */ 3000 static void ppp_destroy_channel(struct channel *pch) 3001 { 3002 atomic_dec(&channel_count); 3003 3004 if (!pch->file.dead) { 3005 /* "can't happen" */ 3006 pr_err("ppp: destroying undead channel %p !\n", pch); 3007 return; 3008 } 3009 skb_queue_purge(&pch->file.xq); 3010 skb_queue_purge(&pch->file.rq); 3011 kfree(pch); 3012 } 3013 3014 static void __exit ppp_cleanup(void) 3015 { 3016 /* should never happen */ 3017 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count)) 3018 pr_err("PPP: removing module but units remain!\n"); 3019 unregister_chrdev(PPP_MAJOR, "ppp"); 3020 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0)); 3021 class_destroy(ppp_class); 3022 unregister_pernet_device(&ppp_net_ops); 3023 } 3024 3025 /* 3026 * Units handling. Caller must protect concurrent access 3027 * by holding all_ppp_mutex 3028 */ 3029 3030 /* associate pointer with specified number */ 3031 static int unit_set(struct idr *p, void *ptr, int n) 3032 { 3033 int unit; 3034 3035 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL); 3036 if (unit == -ENOSPC) 3037 unit = -EINVAL; 3038 return unit; 3039 } 3040 3041 /* get new free unit number and associate pointer with it */ 3042 static int unit_get(struct idr *p, void *ptr) 3043 { 3044 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL); 3045 } 3046 3047 /* put unit number back to a pool */ 3048 static void unit_put(struct idr *p, int n) 3049 { 3050 idr_remove(p, n); 3051 } 3052 3053 /* get pointer associated with the number */ 3054 static void *unit_find(struct idr *p, int n) 3055 { 3056 return idr_find(p, n); 3057 } 3058 3059 /* Module/initialization stuff */ 3060 3061 module_init(ppp_init); 3062 module_exit(ppp_cleanup); 3063 3064 EXPORT_SYMBOL(ppp_register_net_channel); 3065 EXPORT_SYMBOL(ppp_register_channel); 3066 EXPORT_SYMBOL(ppp_unregister_channel); 3067 EXPORT_SYMBOL(ppp_channel_index); 3068 EXPORT_SYMBOL(ppp_unit_number); 3069 EXPORT_SYMBOL(ppp_dev_name); 3070 EXPORT_SYMBOL(ppp_input); 3071 EXPORT_SYMBOL(ppp_input_error); 3072 EXPORT_SYMBOL(ppp_output_wakeup); 3073 EXPORT_SYMBOL(ppp_register_compressor); 3074 EXPORT_SYMBOL(ppp_unregister_compressor); 3075 MODULE_LICENSE("GPL"); 3076 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0); 3077 MODULE_ALIAS("devname:ppp"); 3078