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