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