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/sched/signal.h> 28 #include <linux/kmod.h> 29 #include <linux/init.h> 30 #include <linux/list.h> 31 #include <linux/idr.h> 32 #include <linux/netdevice.h> 33 #include <linux/poll.h> 34 #include <linux/ppp_defs.h> 35 #include <linux/filter.h> 36 #include <linux/ppp-ioctl.h> 37 #include <linux/ppp_channel.h> 38 #include <linux/ppp-comp.h> 39 #include <linux/skbuff.h> 40 #include <linux/rtnetlink.h> 41 #include <linux/if_arp.h> 42 #include <linux/ip.h> 43 #include <linux/tcp.h> 44 #include <linux/spinlock.h> 45 #include <linux/rwsem.h> 46 #include <linux/stddef.h> 47 #include <linux/device.h> 48 #include <linux/mutex.h> 49 #include <linux/slab.h> 50 #include <linux/file.h> 51 #include <asm/unaligned.h> 52 #include <net/slhc_vj.h> 53 #include <linux/atomic.h> 54 #include <linux/refcount.h> 55 56 #include <linux/nsproxy.h> 57 #include <net/net_namespace.h> 58 #include <net/netns/generic.h> 59 60 #define PPP_VERSION "2.4.2" 61 62 /* 63 * Network protocols we support. 64 */ 65 #define NP_IP 0 /* Internet Protocol V4 */ 66 #define NP_IPV6 1 /* Internet Protocol V6 */ 67 #define NP_IPX 2 /* IPX protocol */ 68 #define NP_AT 3 /* Appletalk protocol */ 69 #define NP_MPLS_UC 4 /* MPLS unicast */ 70 #define NP_MPLS_MC 5 /* MPLS multicast */ 71 #define NUM_NP 6 /* Number of NPs. */ 72 73 #define MPHDRLEN 6 /* multilink protocol header length */ 74 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */ 75 76 /* 77 * An instance of /dev/ppp can be associated with either a ppp 78 * interface unit or a ppp channel. In both cases, file->private_data 79 * points to one of these. 80 */ 81 struct ppp_file { 82 enum { 83 INTERFACE=1, CHANNEL 84 } kind; 85 struct sk_buff_head xq; /* pppd transmit queue */ 86 struct sk_buff_head rq; /* receive queue for pppd */ 87 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */ 88 refcount_t refcnt; /* # refs (incl /dev/ppp attached) */ 89 int hdrlen; /* space to leave for headers */ 90 int index; /* interface unit / channel number */ 91 int dead; /* unit/channel has been shut down */ 92 }; 93 94 #define PF_TO_X(pf, X) container_of(pf, X, file) 95 96 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp) 97 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel) 98 99 /* 100 * Data structure to hold primary network stats for which 101 * we want to use 64 bit storage. Other network stats 102 * are stored in dev->stats of the ppp strucute. 103 */ 104 struct ppp_link_stats { 105 u64 rx_packets; 106 u64 tx_packets; 107 u64 rx_bytes; 108 u64 tx_bytes; 109 }; 110 111 /* 112 * Data structure describing one ppp unit. 113 * A ppp unit corresponds to a ppp network interface device 114 * and represents a multilink bundle. 115 * It can have 0 or more ppp channels connected to it. 116 */ 117 struct ppp { 118 struct ppp_file file; /* stuff for read/write/poll 0 */ 119 struct file *owner; /* file that owns this unit 48 */ 120 struct list_head channels; /* list of attached channels 4c */ 121 int n_channels; /* how many channels are attached 54 */ 122 spinlock_t rlock; /* lock for receive side 58 */ 123 spinlock_t wlock; /* lock for transmit side 5c */ 124 int __percpu *xmit_recursion; /* xmit recursion detect */ 125 int mru; /* max receive unit 60 */ 126 unsigned int flags; /* control bits 64 */ 127 unsigned int xstate; /* transmit state bits 68 */ 128 unsigned int rstate; /* receive state bits 6c */ 129 int debug; /* debug flags 70 */ 130 struct slcompress *vj; /* state for VJ header compression */ 131 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */ 132 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */ 133 struct compressor *xcomp; /* transmit packet compressor 8c */ 134 void *xc_state; /* its internal state 90 */ 135 struct compressor *rcomp; /* receive decompressor 94 */ 136 void *rc_state; /* its internal state 98 */ 137 unsigned long last_xmit; /* jiffies when last pkt sent 9c */ 138 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */ 139 struct net_device *dev; /* network interface device a4 */ 140 int closing; /* is device closing down? a8 */ 141 #ifdef CONFIG_PPP_MULTILINK 142 int nxchan; /* next channel to send something on */ 143 u32 nxseq; /* next sequence number to send */ 144 int mrru; /* MP: max reconst. receive unit */ 145 u32 nextseq; /* MP: seq no of next packet */ 146 u32 minseq; /* MP: min of most recent seqnos */ 147 struct sk_buff_head mrq; /* MP: receive reconstruction queue */ 148 #endif /* CONFIG_PPP_MULTILINK */ 149 #ifdef CONFIG_PPP_FILTER 150 struct bpf_prog *pass_filter; /* filter for packets to pass */ 151 struct bpf_prog *active_filter; /* filter for pkts to reset idle */ 152 #endif /* CONFIG_PPP_FILTER */ 153 struct net *ppp_net; /* the net we belong to */ 154 struct ppp_link_stats stats64; /* 64 bit network stats */ 155 }; 156 157 /* 158 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC, 159 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP, 160 * SC_MUST_COMP 161 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR. 162 * Bits in xstate: SC_COMP_RUN 163 */ 164 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \ 165 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \ 166 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP) 167 168 /* 169 * Private data structure for each channel. 170 * This includes the data structure used for multilink. 171 */ 172 struct channel { 173 struct ppp_file file; /* stuff for read/write/poll */ 174 struct list_head list; /* link in all/new_channels list */ 175 struct ppp_channel *chan; /* public channel data structure */ 176 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */ 177 spinlock_t downl; /* protects `chan', file.xq dequeue */ 178 struct ppp *ppp; /* ppp unit we're connected to */ 179 struct net *chan_net; /* the net channel belongs to */ 180 struct list_head clist; /* link in list of channels per unit */ 181 rwlock_t upl; /* protects `ppp' */ 182 #ifdef CONFIG_PPP_MULTILINK 183 u8 avail; /* flag used in multilink stuff */ 184 u8 had_frag; /* >= 1 fragments have been sent */ 185 u32 lastseq; /* MP: last sequence # received */ 186 int speed; /* speed of the corresponding ppp channel*/ 187 #endif /* CONFIG_PPP_MULTILINK */ 188 }; 189 190 struct ppp_config { 191 struct file *file; 192 s32 unit; 193 bool ifname_is_set; 194 }; 195 196 /* 197 * SMP locking issues: 198 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels 199 * list and the ppp.n_channels field, you need to take both locks 200 * before you modify them. 201 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock -> 202 * channel.downl. 203 */ 204 205 static DEFINE_MUTEX(ppp_mutex); 206 static atomic_t ppp_unit_count = ATOMIC_INIT(0); 207 static atomic_t channel_count = ATOMIC_INIT(0); 208 209 /* per-net private data for this module */ 210 static unsigned int ppp_net_id __read_mostly; 211 struct ppp_net { 212 /* units to ppp mapping */ 213 struct idr units_idr; 214 215 /* 216 * all_ppp_mutex protects the units_idr mapping. 217 * It also ensures that finding a ppp unit in the units_idr 218 * map and updating its file.refcnt field is atomic. 219 */ 220 struct mutex all_ppp_mutex; 221 222 /* channels */ 223 struct list_head all_channels; 224 struct list_head new_channels; 225 int last_channel_index; 226 227 /* 228 * all_channels_lock protects all_channels and 229 * last_channel_index, and the atomicity of find 230 * a channel and updating its file.refcnt field. 231 */ 232 spinlock_t all_channels_lock; 233 }; 234 235 /* Get the PPP protocol number from a skb */ 236 #define PPP_PROTO(skb) get_unaligned_be16((skb)->data) 237 238 /* We limit the length of ppp->file.rq to this (arbitrary) value */ 239 #define PPP_MAX_RQLEN 32 240 241 /* 242 * Maximum number of multilink fragments queued up. 243 * This has to be large enough to cope with the maximum latency of 244 * the slowest channel relative to the others. Strictly it should 245 * depend on the number of channels and their characteristics. 246 */ 247 #define PPP_MP_MAX_QLEN 128 248 249 /* Multilink header bits. */ 250 #define B 0x80 /* this fragment begins a packet */ 251 #define E 0x40 /* this fragment ends a packet */ 252 253 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */ 254 #define seq_before(a, b) ((s32)((a) - (b)) < 0) 255 #define seq_after(a, b) ((s32)((a) - (b)) > 0) 256 257 /* Prototypes. */ 258 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 259 struct file *file, unsigned int cmd, unsigned long arg); 260 static void ppp_xmit_process(struct ppp *ppp); 261 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb); 262 static void ppp_push(struct ppp *ppp); 263 static void ppp_channel_push(struct channel *pch); 264 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, 265 struct channel *pch); 266 static void ppp_receive_error(struct ppp *ppp); 267 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb); 268 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp, 269 struct sk_buff *skb); 270 #ifdef CONFIG_PPP_MULTILINK 271 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, 272 struct channel *pch); 273 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb); 274 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp); 275 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb); 276 #endif /* CONFIG_PPP_MULTILINK */ 277 static int ppp_set_compress(struct ppp *ppp, unsigned long arg); 278 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound); 279 static void ppp_ccp_closed(struct ppp *ppp); 280 static struct compressor *find_compressor(int type); 281 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st); 282 static int ppp_create_interface(struct net *net, struct file *file, int *unit); 283 static void init_ppp_file(struct ppp_file *pf, int kind); 284 static void ppp_destroy_interface(struct ppp *ppp); 285 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit); 286 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit); 287 static int ppp_connect_channel(struct channel *pch, int unit); 288 static int ppp_disconnect_channel(struct channel *pch); 289 static void ppp_destroy_channel(struct channel *pch); 290 static int unit_get(struct idr *p, void *ptr); 291 static int unit_set(struct idr *p, void *ptr, int n); 292 static void unit_put(struct idr *p, int n); 293 static void *unit_find(struct idr *p, int n); 294 static void ppp_setup(struct net_device *dev); 295 296 static const struct net_device_ops ppp_netdev_ops; 297 298 static struct class *ppp_class; 299 300 /* per net-namespace data */ 301 static inline struct ppp_net *ppp_pernet(struct net *net) 302 { 303 BUG_ON(!net); 304 305 return net_generic(net, ppp_net_id); 306 } 307 308 /* Translates a PPP protocol number to a NP index (NP == network protocol) */ 309 static inline int proto_to_npindex(int proto) 310 { 311 switch (proto) { 312 case PPP_IP: 313 return NP_IP; 314 case PPP_IPV6: 315 return NP_IPV6; 316 case PPP_IPX: 317 return NP_IPX; 318 case PPP_AT: 319 return NP_AT; 320 case PPP_MPLS_UC: 321 return NP_MPLS_UC; 322 case PPP_MPLS_MC: 323 return NP_MPLS_MC; 324 } 325 return -EINVAL; 326 } 327 328 /* Translates an NP index into a PPP protocol number */ 329 static const int npindex_to_proto[NUM_NP] = { 330 PPP_IP, 331 PPP_IPV6, 332 PPP_IPX, 333 PPP_AT, 334 PPP_MPLS_UC, 335 PPP_MPLS_MC, 336 }; 337 338 /* Translates an ethertype into an NP index */ 339 static inline int ethertype_to_npindex(int ethertype) 340 { 341 switch (ethertype) { 342 case ETH_P_IP: 343 return NP_IP; 344 case ETH_P_IPV6: 345 return NP_IPV6; 346 case ETH_P_IPX: 347 return NP_IPX; 348 case ETH_P_PPPTALK: 349 case ETH_P_ATALK: 350 return NP_AT; 351 case ETH_P_MPLS_UC: 352 return NP_MPLS_UC; 353 case ETH_P_MPLS_MC: 354 return NP_MPLS_MC; 355 } 356 return -1; 357 } 358 359 /* Translates an NP index into an ethertype */ 360 static const int npindex_to_ethertype[NUM_NP] = { 361 ETH_P_IP, 362 ETH_P_IPV6, 363 ETH_P_IPX, 364 ETH_P_PPPTALK, 365 ETH_P_MPLS_UC, 366 ETH_P_MPLS_MC, 367 }; 368 369 /* 370 * Locking shorthand. 371 */ 372 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock) 373 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock) 374 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock) 375 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock) 376 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \ 377 ppp_recv_lock(ppp); } while (0) 378 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \ 379 ppp_xmit_unlock(ppp); } while (0) 380 381 /* 382 * /dev/ppp device routines. 383 * The /dev/ppp device is used by pppd to control the ppp unit. 384 * It supports the read, write, ioctl and poll functions. 385 * Open instances of /dev/ppp can be in one of three states: 386 * unattached, attached to a ppp unit, or attached to a ppp channel. 387 */ 388 static int ppp_open(struct inode *inode, struct file *file) 389 { 390 /* 391 * This could (should?) be enforced by the permissions on /dev/ppp. 392 */ 393 if (!ns_capable(file->f_cred->user_ns, CAP_NET_ADMIN)) 394 return -EPERM; 395 return 0; 396 } 397 398 static int ppp_release(struct inode *unused, struct file *file) 399 { 400 struct ppp_file *pf = file->private_data; 401 struct ppp *ppp; 402 403 if (pf) { 404 file->private_data = NULL; 405 if (pf->kind == INTERFACE) { 406 ppp = PF_TO_PPP(pf); 407 rtnl_lock(); 408 if (file == ppp->owner) 409 unregister_netdevice(ppp->dev); 410 rtnl_unlock(); 411 } 412 if (refcount_dec_and_test(&pf->refcnt)) { 413 switch (pf->kind) { 414 case INTERFACE: 415 ppp_destroy_interface(PF_TO_PPP(pf)); 416 break; 417 case CHANNEL: 418 ppp_destroy_channel(PF_TO_CHANNEL(pf)); 419 break; 420 } 421 } 422 } 423 return 0; 424 } 425 426 static ssize_t ppp_read(struct file *file, char __user *buf, 427 size_t count, loff_t *ppos) 428 { 429 struct ppp_file *pf = file->private_data; 430 DECLARE_WAITQUEUE(wait, current); 431 ssize_t ret; 432 struct sk_buff *skb = NULL; 433 struct iovec iov; 434 struct iov_iter to; 435 436 ret = count; 437 438 if (!pf) 439 return -ENXIO; 440 add_wait_queue(&pf->rwait, &wait); 441 for (;;) { 442 set_current_state(TASK_INTERRUPTIBLE); 443 skb = skb_dequeue(&pf->rq); 444 if (skb) 445 break; 446 ret = 0; 447 if (pf->dead) 448 break; 449 if (pf->kind == INTERFACE) { 450 /* 451 * Return 0 (EOF) on an interface that has no 452 * channels connected, unless it is looping 453 * network traffic (demand mode). 454 */ 455 struct ppp *ppp = PF_TO_PPP(pf); 456 457 ppp_recv_lock(ppp); 458 if (ppp->n_channels == 0 && 459 (ppp->flags & SC_LOOP_TRAFFIC) == 0) { 460 ppp_recv_unlock(ppp); 461 break; 462 } 463 ppp_recv_unlock(ppp); 464 } 465 ret = -EAGAIN; 466 if (file->f_flags & O_NONBLOCK) 467 break; 468 ret = -ERESTARTSYS; 469 if (signal_pending(current)) 470 break; 471 schedule(); 472 } 473 set_current_state(TASK_RUNNING); 474 remove_wait_queue(&pf->rwait, &wait); 475 476 if (!skb) 477 goto out; 478 479 ret = -EOVERFLOW; 480 if (skb->len > count) 481 goto outf; 482 ret = -EFAULT; 483 iov.iov_base = buf; 484 iov.iov_len = count; 485 iov_iter_init(&to, READ, &iov, 1, count); 486 if (skb_copy_datagram_iter(skb, 0, &to, skb->len)) 487 goto outf; 488 ret = skb->len; 489 490 outf: 491 kfree_skb(skb); 492 out: 493 return ret; 494 } 495 496 static ssize_t ppp_write(struct file *file, const char __user *buf, 497 size_t count, loff_t *ppos) 498 { 499 struct ppp_file *pf = file->private_data; 500 struct sk_buff *skb; 501 ssize_t ret; 502 503 if (!pf) 504 return -ENXIO; 505 ret = -ENOMEM; 506 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL); 507 if (!skb) 508 goto out; 509 skb_reserve(skb, pf->hdrlen); 510 ret = -EFAULT; 511 if (copy_from_user(skb_put(skb, count), buf, count)) { 512 kfree_skb(skb); 513 goto out; 514 } 515 516 skb_queue_tail(&pf->xq, skb); 517 518 switch (pf->kind) { 519 case INTERFACE: 520 ppp_xmit_process(PF_TO_PPP(pf)); 521 break; 522 case CHANNEL: 523 ppp_channel_push(PF_TO_CHANNEL(pf)); 524 break; 525 } 526 527 ret = count; 528 529 out: 530 return ret; 531 } 532 533 /* No kernel lock - fine */ 534 static unsigned int ppp_poll(struct file *file, poll_table *wait) 535 { 536 struct ppp_file *pf = file->private_data; 537 unsigned int mask; 538 539 if (!pf) 540 return 0; 541 poll_wait(file, &pf->rwait, wait); 542 mask = POLLOUT | POLLWRNORM; 543 if (skb_peek(&pf->rq)) 544 mask |= POLLIN | POLLRDNORM; 545 if (pf->dead) 546 mask |= POLLHUP; 547 else if (pf->kind == INTERFACE) { 548 /* see comment in ppp_read */ 549 struct ppp *ppp = PF_TO_PPP(pf); 550 551 ppp_recv_lock(ppp); 552 if (ppp->n_channels == 0 && 553 (ppp->flags & SC_LOOP_TRAFFIC) == 0) 554 mask |= POLLIN | POLLRDNORM; 555 ppp_recv_unlock(ppp); 556 } 557 558 return mask; 559 } 560 561 #ifdef CONFIG_PPP_FILTER 562 static int get_filter(void __user *arg, struct sock_filter **p) 563 { 564 struct sock_fprog uprog; 565 struct sock_filter *code = NULL; 566 int len; 567 568 if (copy_from_user(&uprog, arg, sizeof(uprog))) 569 return -EFAULT; 570 571 if (!uprog.len) { 572 *p = NULL; 573 return 0; 574 } 575 576 len = uprog.len * sizeof(struct sock_filter); 577 code = memdup_user(uprog.filter, len); 578 if (IS_ERR(code)) 579 return PTR_ERR(code); 580 581 *p = code; 582 return uprog.len; 583 } 584 #endif /* CONFIG_PPP_FILTER */ 585 586 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 587 { 588 struct ppp_file *pf; 589 struct ppp *ppp; 590 int err = -EFAULT, val, val2, i; 591 struct ppp_idle idle; 592 struct npioctl npi; 593 int unit, cflags; 594 struct slcompress *vj; 595 void __user *argp = (void __user *)arg; 596 int __user *p = argp; 597 598 mutex_lock(&ppp_mutex); 599 600 pf = file->private_data; 601 if (!pf) { 602 err = ppp_unattached_ioctl(current->nsproxy->net_ns, 603 pf, file, cmd, arg); 604 goto out; 605 } 606 607 if (cmd == PPPIOCDETACH) { 608 /* 609 * We have to be careful here... if the file descriptor 610 * has been dup'd, we could have another process in the 611 * middle of a poll using the same file *, so we had 612 * better not free the interface data structures - 613 * instead we fail the ioctl. Even in this case, we 614 * shut down the interface if we are the owner of it. 615 * Actually, we should get rid of PPPIOCDETACH, userland 616 * (i.e. pppd) could achieve the same effect by closing 617 * this fd and reopening /dev/ppp. 618 */ 619 err = -EINVAL; 620 if (pf->kind == INTERFACE) { 621 ppp = PF_TO_PPP(pf); 622 rtnl_lock(); 623 if (file == ppp->owner) 624 unregister_netdevice(ppp->dev); 625 rtnl_unlock(); 626 } 627 if (atomic_long_read(&file->f_count) < 2) { 628 ppp_release(NULL, file); 629 err = 0; 630 } else 631 pr_warn("PPPIOCDETACH file->f_count=%ld\n", 632 atomic_long_read(&file->f_count)); 633 goto out; 634 } 635 636 if (pf->kind == CHANNEL) { 637 struct channel *pch; 638 struct ppp_channel *chan; 639 640 pch = PF_TO_CHANNEL(pf); 641 642 switch (cmd) { 643 case PPPIOCCONNECT: 644 if (get_user(unit, p)) 645 break; 646 err = ppp_connect_channel(pch, unit); 647 break; 648 649 case PPPIOCDISCONN: 650 err = ppp_disconnect_channel(pch); 651 break; 652 653 default: 654 down_read(&pch->chan_sem); 655 chan = pch->chan; 656 err = -ENOTTY; 657 if (chan && chan->ops->ioctl) 658 err = chan->ops->ioctl(chan, cmd, arg); 659 up_read(&pch->chan_sem); 660 } 661 goto out; 662 } 663 664 if (pf->kind != INTERFACE) { 665 /* can't happen */ 666 pr_err("PPP: not interface or channel??\n"); 667 err = -EINVAL; 668 goto out; 669 } 670 671 ppp = PF_TO_PPP(pf); 672 switch (cmd) { 673 case PPPIOCSMRU: 674 if (get_user(val, p)) 675 break; 676 ppp->mru = val; 677 err = 0; 678 break; 679 680 case PPPIOCSFLAGS: 681 if (get_user(val, p)) 682 break; 683 ppp_lock(ppp); 684 cflags = ppp->flags & ~val; 685 #ifdef CONFIG_PPP_MULTILINK 686 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK)) 687 ppp->nextseq = 0; 688 #endif 689 ppp->flags = val & SC_FLAG_BITS; 690 ppp_unlock(ppp); 691 if (cflags & SC_CCP_OPEN) 692 ppp_ccp_closed(ppp); 693 err = 0; 694 break; 695 696 case PPPIOCGFLAGS: 697 val = ppp->flags | ppp->xstate | ppp->rstate; 698 if (put_user(val, p)) 699 break; 700 err = 0; 701 break; 702 703 case PPPIOCSCOMPRESS: 704 err = ppp_set_compress(ppp, arg); 705 break; 706 707 case PPPIOCGUNIT: 708 if (put_user(ppp->file.index, p)) 709 break; 710 err = 0; 711 break; 712 713 case PPPIOCSDEBUG: 714 if (get_user(val, p)) 715 break; 716 ppp->debug = val; 717 err = 0; 718 break; 719 720 case PPPIOCGDEBUG: 721 if (put_user(ppp->debug, p)) 722 break; 723 err = 0; 724 break; 725 726 case PPPIOCGIDLE: 727 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ; 728 idle.recv_idle = (jiffies - ppp->last_recv) / HZ; 729 if (copy_to_user(argp, &idle, sizeof(idle))) 730 break; 731 err = 0; 732 break; 733 734 case PPPIOCSMAXCID: 735 if (get_user(val, p)) 736 break; 737 val2 = 15; 738 if ((val >> 16) != 0) { 739 val2 = val >> 16; 740 val &= 0xffff; 741 } 742 vj = slhc_init(val2+1, val+1); 743 if (IS_ERR(vj)) { 744 err = PTR_ERR(vj); 745 break; 746 } 747 ppp_lock(ppp); 748 if (ppp->vj) 749 slhc_free(ppp->vj); 750 ppp->vj = vj; 751 ppp_unlock(ppp); 752 err = 0; 753 break; 754 755 case PPPIOCGNPMODE: 756 case PPPIOCSNPMODE: 757 if (copy_from_user(&npi, argp, sizeof(npi))) 758 break; 759 err = proto_to_npindex(npi.protocol); 760 if (err < 0) 761 break; 762 i = err; 763 if (cmd == PPPIOCGNPMODE) { 764 err = -EFAULT; 765 npi.mode = ppp->npmode[i]; 766 if (copy_to_user(argp, &npi, sizeof(npi))) 767 break; 768 } else { 769 ppp->npmode[i] = npi.mode; 770 /* we may be able to transmit more packets now (??) */ 771 netif_wake_queue(ppp->dev); 772 } 773 err = 0; 774 break; 775 776 #ifdef CONFIG_PPP_FILTER 777 case PPPIOCSPASS: 778 { 779 struct sock_filter *code; 780 781 err = get_filter(argp, &code); 782 if (err >= 0) { 783 struct bpf_prog *pass_filter = NULL; 784 struct sock_fprog_kern fprog = { 785 .len = err, 786 .filter = code, 787 }; 788 789 err = 0; 790 if (fprog.filter) 791 err = bpf_prog_create(&pass_filter, &fprog); 792 if (!err) { 793 ppp_lock(ppp); 794 if (ppp->pass_filter) 795 bpf_prog_destroy(ppp->pass_filter); 796 ppp->pass_filter = pass_filter; 797 ppp_unlock(ppp); 798 } 799 kfree(code); 800 } 801 break; 802 } 803 case PPPIOCSACTIVE: 804 { 805 struct sock_filter *code; 806 807 err = get_filter(argp, &code); 808 if (err >= 0) { 809 struct bpf_prog *active_filter = NULL; 810 struct sock_fprog_kern fprog = { 811 .len = err, 812 .filter = code, 813 }; 814 815 err = 0; 816 if (fprog.filter) 817 err = bpf_prog_create(&active_filter, &fprog); 818 if (!err) { 819 ppp_lock(ppp); 820 if (ppp->active_filter) 821 bpf_prog_destroy(ppp->active_filter); 822 ppp->active_filter = active_filter; 823 ppp_unlock(ppp); 824 } 825 kfree(code); 826 } 827 break; 828 } 829 #endif /* CONFIG_PPP_FILTER */ 830 831 #ifdef CONFIG_PPP_MULTILINK 832 case PPPIOCSMRRU: 833 if (get_user(val, p)) 834 break; 835 ppp_recv_lock(ppp); 836 ppp->mrru = val; 837 ppp_recv_unlock(ppp); 838 err = 0; 839 break; 840 #endif /* CONFIG_PPP_MULTILINK */ 841 842 default: 843 err = -ENOTTY; 844 } 845 846 out: 847 mutex_unlock(&ppp_mutex); 848 849 return err; 850 } 851 852 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 853 struct file *file, unsigned int cmd, unsigned long arg) 854 { 855 int unit, err = -EFAULT; 856 struct ppp *ppp; 857 struct channel *chan; 858 struct ppp_net *pn; 859 int __user *p = (int __user *)arg; 860 861 switch (cmd) { 862 case PPPIOCNEWUNIT: 863 /* Create a new ppp unit */ 864 if (get_user(unit, p)) 865 break; 866 err = ppp_create_interface(net, file, &unit); 867 if (err < 0) 868 break; 869 870 err = -EFAULT; 871 if (put_user(unit, p)) 872 break; 873 err = 0; 874 break; 875 876 case PPPIOCATTACH: 877 /* Attach to an existing ppp unit */ 878 if (get_user(unit, p)) 879 break; 880 err = -ENXIO; 881 pn = ppp_pernet(net); 882 mutex_lock(&pn->all_ppp_mutex); 883 ppp = ppp_find_unit(pn, unit); 884 if (ppp) { 885 refcount_inc(&ppp->file.refcnt); 886 file->private_data = &ppp->file; 887 err = 0; 888 } 889 mutex_unlock(&pn->all_ppp_mutex); 890 break; 891 892 case PPPIOCATTCHAN: 893 if (get_user(unit, p)) 894 break; 895 err = -ENXIO; 896 pn = ppp_pernet(net); 897 spin_lock_bh(&pn->all_channels_lock); 898 chan = ppp_find_channel(pn, unit); 899 if (chan) { 900 refcount_inc(&chan->file.refcnt); 901 file->private_data = &chan->file; 902 err = 0; 903 } 904 spin_unlock_bh(&pn->all_channels_lock); 905 break; 906 907 default: 908 err = -ENOTTY; 909 } 910 911 return err; 912 } 913 914 static const struct file_operations ppp_device_fops = { 915 .owner = THIS_MODULE, 916 .read = ppp_read, 917 .write = ppp_write, 918 .poll = ppp_poll, 919 .unlocked_ioctl = ppp_ioctl, 920 .open = ppp_open, 921 .release = ppp_release, 922 .llseek = noop_llseek, 923 }; 924 925 static __net_init int ppp_init_net(struct net *net) 926 { 927 struct ppp_net *pn = net_generic(net, ppp_net_id); 928 929 idr_init(&pn->units_idr); 930 mutex_init(&pn->all_ppp_mutex); 931 932 INIT_LIST_HEAD(&pn->all_channels); 933 INIT_LIST_HEAD(&pn->new_channels); 934 935 spin_lock_init(&pn->all_channels_lock); 936 937 return 0; 938 } 939 940 static __net_exit void ppp_exit_net(struct net *net) 941 { 942 struct ppp_net *pn = net_generic(net, ppp_net_id); 943 struct net_device *dev; 944 struct net_device *aux; 945 struct ppp *ppp; 946 LIST_HEAD(list); 947 int id; 948 949 rtnl_lock(); 950 for_each_netdev_safe(net, dev, aux) { 951 if (dev->netdev_ops == &ppp_netdev_ops) 952 unregister_netdevice_queue(dev, &list); 953 } 954 955 idr_for_each_entry(&pn->units_idr, ppp, id) 956 /* Skip devices already unregistered by previous loop */ 957 if (!net_eq(dev_net(ppp->dev), net)) 958 unregister_netdevice_queue(ppp->dev, &list); 959 960 unregister_netdevice_many(&list); 961 rtnl_unlock(); 962 963 mutex_destroy(&pn->all_ppp_mutex); 964 idr_destroy(&pn->units_idr); 965 WARN_ON_ONCE(!list_empty(&pn->all_channels)); 966 WARN_ON_ONCE(!list_empty(&pn->new_channels)); 967 } 968 969 static struct pernet_operations ppp_net_ops = { 970 .init = ppp_init_net, 971 .exit = ppp_exit_net, 972 .id = &ppp_net_id, 973 .size = sizeof(struct ppp_net), 974 }; 975 976 static int ppp_unit_register(struct ppp *ppp, int unit, bool ifname_is_set) 977 { 978 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 979 int ret; 980 981 mutex_lock(&pn->all_ppp_mutex); 982 983 if (unit < 0) { 984 ret = unit_get(&pn->units_idr, ppp); 985 if (ret < 0) 986 goto err; 987 } else { 988 /* Caller asked for a specific unit number. Fail with -EEXIST 989 * if unavailable. For backward compatibility, return -EEXIST 990 * too if idr allocation fails; this makes pppd retry without 991 * requesting a specific unit number. 992 */ 993 if (unit_find(&pn->units_idr, unit)) { 994 ret = -EEXIST; 995 goto err; 996 } 997 ret = unit_set(&pn->units_idr, ppp, unit); 998 if (ret < 0) { 999 /* Rewrite error for backward compatibility */ 1000 ret = -EEXIST; 1001 goto err; 1002 } 1003 } 1004 ppp->file.index = ret; 1005 1006 if (!ifname_is_set) 1007 snprintf(ppp->dev->name, IFNAMSIZ, "ppp%i", ppp->file.index); 1008 1009 ret = register_netdevice(ppp->dev); 1010 if (ret < 0) 1011 goto err_unit; 1012 1013 atomic_inc(&ppp_unit_count); 1014 1015 mutex_unlock(&pn->all_ppp_mutex); 1016 1017 return 0; 1018 1019 err_unit: 1020 unit_put(&pn->units_idr, ppp->file.index); 1021 err: 1022 mutex_unlock(&pn->all_ppp_mutex); 1023 1024 return ret; 1025 } 1026 1027 static int ppp_dev_configure(struct net *src_net, struct net_device *dev, 1028 const struct ppp_config *conf) 1029 { 1030 struct ppp *ppp = netdev_priv(dev); 1031 int indx; 1032 int err; 1033 int cpu; 1034 1035 ppp->dev = dev; 1036 ppp->ppp_net = src_net; 1037 ppp->mru = PPP_MRU; 1038 ppp->owner = conf->file; 1039 1040 init_ppp_file(&ppp->file, INTERFACE); 1041 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */ 1042 1043 for (indx = 0; indx < NUM_NP; ++indx) 1044 ppp->npmode[indx] = NPMODE_PASS; 1045 INIT_LIST_HEAD(&ppp->channels); 1046 spin_lock_init(&ppp->rlock); 1047 spin_lock_init(&ppp->wlock); 1048 1049 ppp->xmit_recursion = alloc_percpu(int); 1050 if (!ppp->xmit_recursion) { 1051 err = -ENOMEM; 1052 goto err1; 1053 } 1054 for_each_possible_cpu(cpu) 1055 (*per_cpu_ptr(ppp->xmit_recursion, cpu)) = 0; 1056 1057 #ifdef CONFIG_PPP_MULTILINK 1058 ppp->minseq = -1; 1059 skb_queue_head_init(&ppp->mrq); 1060 #endif /* CONFIG_PPP_MULTILINK */ 1061 #ifdef CONFIG_PPP_FILTER 1062 ppp->pass_filter = NULL; 1063 ppp->active_filter = NULL; 1064 #endif /* CONFIG_PPP_FILTER */ 1065 1066 err = ppp_unit_register(ppp, conf->unit, conf->ifname_is_set); 1067 if (err < 0) 1068 goto err2; 1069 1070 conf->file->private_data = &ppp->file; 1071 1072 return 0; 1073 err2: 1074 free_percpu(ppp->xmit_recursion); 1075 err1: 1076 return err; 1077 } 1078 1079 static const struct nla_policy ppp_nl_policy[IFLA_PPP_MAX + 1] = { 1080 [IFLA_PPP_DEV_FD] = { .type = NLA_S32 }, 1081 }; 1082 1083 static int ppp_nl_validate(struct nlattr *tb[], struct nlattr *data[], 1084 struct netlink_ext_ack *extack) 1085 { 1086 if (!data) 1087 return -EINVAL; 1088 1089 if (!data[IFLA_PPP_DEV_FD]) 1090 return -EINVAL; 1091 if (nla_get_s32(data[IFLA_PPP_DEV_FD]) < 0) 1092 return -EBADF; 1093 1094 return 0; 1095 } 1096 1097 static int ppp_nl_newlink(struct net *src_net, struct net_device *dev, 1098 struct nlattr *tb[], struct nlattr *data[], 1099 struct netlink_ext_ack *extack) 1100 { 1101 struct ppp_config conf = { 1102 .unit = -1, 1103 .ifname_is_set = true, 1104 }; 1105 struct file *file; 1106 int err; 1107 1108 file = fget(nla_get_s32(data[IFLA_PPP_DEV_FD])); 1109 if (!file) 1110 return -EBADF; 1111 1112 /* rtnl_lock is already held here, but ppp_create_interface() locks 1113 * ppp_mutex before holding rtnl_lock. Using mutex_trylock() avoids 1114 * possible deadlock due to lock order inversion, at the cost of 1115 * pushing the problem back to userspace. 1116 */ 1117 if (!mutex_trylock(&ppp_mutex)) { 1118 err = -EBUSY; 1119 goto out; 1120 } 1121 1122 if (file->f_op != &ppp_device_fops || file->private_data) { 1123 err = -EBADF; 1124 goto out_unlock; 1125 } 1126 1127 conf.file = file; 1128 1129 /* Don't use device name generated by the rtnetlink layer when ifname 1130 * isn't specified. Let ppp_dev_configure() set the device name using 1131 * the PPP unit identifer as suffix (i.e. ppp<unit_id>). This allows 1132 * userspace to infer the device name using to the PPPIOCGUNIT ioctl. 1133 */ 1134 if (!tb[IFLA_IFNAME]) 1135 conf.ifname_is_set = false; 1136 1137 err = ppp_dev_configure(src_net, dev, &conf); 1138 1139 out_unlock: 1140 mutex_unlock(&ppp_mutex); 1141 out: 1142 fput(file); 1143 1144 return err; 1145 } 1146 1147 static void ppp_nl_dellink(struct net_device *dev, struct list_head *head) 1148 { 1149 unregister_netdevice_queue(dev, head); 1150 } 1151 1152 static size_t ppp_nl_get_size(const struct net_device *dev) 1153 { 1154 return 0; 1155 } 1156 1157 static int ppp_nl_fill_info(struct sk_buff *skb, const struct net_device *dev) 1158 { 1159 return 0; 1160 } 1161 1162 static struct net *ppp_nl_get_link_net(const struct net_device *dev) 1163 { 1164 struct ppp *ppp = netdev_priv(dev); 1165 1166 return ppp->ppp_net; 1167 } 1168 1169 static struct rtnl_link_ops ppp_link_ops __read_mostly = { 1170 .kind = "ppp", 1171 .maxtype = IFLA_PPP_MAX, 1172 .policy = ppp_nl_policy, 1173 .priv_size = sizeof(struct ppp), 1174 .setup = ppp_setup, 1175 .validate = ppp_nl_validate, 1176 .newlink = ppp_nl_newlink, 1177 .dellink = ppp_nl_dellink, 1178 .get_size = ppp_nl_get_size, 1179 .fill_info = ppp_nl_fill_info, 1180 .get_link_net = ppp_nl_get_link_net, 1181 }; 1182 1183 #define PPP_MAJOR 108 1184 1185 /* Called at boot time if ppp is compiled into the kernel, 1186 or at module load time (from init_module) if compiled as a module. */ 1187 static int __init ppp_init(void) 1188 { 1189 int err; 1190 1191 pr_info("PPP generic driver version " PPP_VERSION "\n"); 1192 1193 err = register_pernet_device(&ppp_net_ops); 1194 if (err) { 1195 pr_err("failed to register PPP pernet device (%d)\n", err); 1196 goto out; 1197 } 1198 1199 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops); 1200 if (err) { 1201 pr_err("failed to register PPP device (%d)\n", err); 1202 goto out_net; 1203 } 1204 1205 ppp_class = class_create(THIS_MODULE, "ppp"); 1206 if (IS_ERR(ppp_class)) { 1207 err = PTR_ERR(ppp_class); 1208 goto out_chrdev; 1209 } 1210 1211 err = rtnl_link_register(&ppp_link_ops); 1212 if (err) { 1213 pr_err("failed to register rtnetlink PPP handler\n"); 1214 goto out_class; 1215 } 1216 1217 /* not a big deal if we fail here :-) */ 1218 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp"); 1219 1220 return 0; 1221 1222 out_class: 1223 class_destroy(ppp_class); 1224 out_chrdev: 1225 unregister_chrdev(PPP_MAJOR, "ppp"); 1226 out_net: 1227 unregister_pernet_device(&ppp_net_ops); 1228 out: 1229 return err; 1230 } 1231 1232 /* 1233 * Network interface unit routines. 1234 */ 1235 static netdev_tx_t 1236 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev) 1237 { 1238 struct ppp *ppp = netdev_priv(dev); 1239 int npi, proto; 1240 unsigned char *pp; 1241 1242 npi = ethertype_to_npindex(ntohs(skb->protocol)); 1243 if (npi < 0) 1244 goto outf; 1245 1246 /* Drop, accept or reject the packet */ 1247 switch (ppp->npmode[npi]) { 1248 case NPMODE_PASS: 1249 break; 1250 case NPMODE_QUEUE: 1251 /* it would be nice to have a way to tell the network 1252 system to queue this one up for later. */ 1253 goto outf; 1254 case NPMODE_DROP: 1255 case NPMODE_ERROR: 1256 goto outf; 1257 } 1258 1259 /* Put the 2-byte PPP protocol number on the front, 1260 making sure there is room for the address and control fields. */ 1261 if (skb_cow_head(skb, PPP_HDRLEN)) 1262 goto outf; 1263 1264 pp = skb_push(skb, 2); 1265 proto = npindex_to_proto[npi]; 1266 put_unaligned_be16(proto, pp); 1267 1268 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev))); 1269 skb_queue_tail(&ppp->file.xq, skb); 1270 ppp_xmit_process(ppp); 1271 return NETDEV_TX_OK; 1272 1273 outf: 1274 kfree_skb(skb); 1275 ++dev->stats.tx_dropped; 1276 return NETDEV_TX_OK; 1277 } 1278 1279 static int 1280 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 1281 { 1282 struct ppp *ppp = netdev_priv(dev); 1283 int err = -EFAULT; 1284 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data; 1285 struct ppp_stats stats; 1286 struct ppp_comp_stats cstats; 1287 char *vers; 1288 1289 switch (cmd) { 1290 case SIOCGPPPSTATS: 1291 ppp_get_stats(ppp, &stats); 1292 if (copy_to_user(addr, &stats, sizeof(stats))) 1293 break; 1294 err = 0; 1295 break; 1296 1297 case SIOCGPPPCSTATS: 1298 memset(&cstats, 0, sizeof(cstats)); 1299 if (ppp->xc_state) 1300 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c); 1301 if (ppp->rc_state) 1302 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d); 1303 if (copy_to_user(addr, &cstats, sizeof(cstats))) 1304 break; 1305 err = 0; 1306 break; 1307 1308 case SIOCGPPPVER: 1309 vers = PPP_VERSION; 1310 if (copy_to_user(addr, vers, strlen(vers) + 1)) 1311 break; 1312 err = 0; 1313 break; 1314 1315 default: 1316 err = -EINVAL; 1317 } 1318 1319 return err; 1320 } 1321 1322 static void 1323 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64) 1324 { 1325 struct ppp *ppp = netdev_priv(dev); 1326 1327 ppp_recv_lock(ppp); 1328 stats64->rx_packets = ppp->stats64.rx_packets; 1329 stats64->rx_bytes = ppp->stats64.rx_bytes; 1330 ppp_recv_unlock(ppp); 1331 1332 ppp_xmit_lock(ppp); 1333 stats64->tx_packets = ppp->stats64.tx_packets; 1334 stats64->tx_bytes = ppp->stats64.tx_bytes; 1335 ppp_xmit_unlock(ppp); 1336 1337 stats64->rx_errors = dev->stats.rx_errors; 1338 stats64->tx_errors = dev->stats.tx_errors; 1339 stats64->rx_dropped = dev->stats.rx_dropped; 1340 stats64->tx_dropped = dev->stats.tx_dropped; 1341 stats64->rx_length_errors = dev->stats.rx_length_errors; 1342 } 1343 1344 static int ppp_dev_init(struct net_device *dev) 1345 { 1346 struct ppp *ppp; 1347 1348 netdev_lockdep_set_classes(dev); 1349 1350 ppp = netdev_priv(dev); 1351 /* Let the netdevice take a reference on the ppp file. This ensures 1352 * that ppp_destroy_interface() won't run before the device gets 1353 * unregistered. 1354 */ 1355 refcount_inc(&ppp->file.refcnt); 1356 1357 return 0; 1358 } 1359 1360 static void ppp_dev_uninit(struct net_device *dev) 1361 { 1362 struct ppp *ppp = netdev_priv(dev); 1363 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 1364 1365 ppp_lock(ppp); 1366 ppp->closing = 1; 1367 ppp_unlock(ppp); 1368 1369 mutex_lock(&pn->all_ppp_mutex); 1370 unit_put(&pn->units_idr, ppp->file.index); 1371 mutex_unlock(&pn->all_ppp_mutex); 1372 1373 ppp->owner = NULL; 1374 1375 ppp->file.dead = 1; 1376 wake_up_interruptible(&ppp->file.rwait); 1377 } 1378 1379 static void ppp_dev_priv_destructor(struct net_device *dev) 1380 { 1381 struct ppp *ppp; 1382 1383 ppp = netdev_priv(dev); 1384 if (refcount_dec_and_test(&ppp->file.refcnt)) 1385 ppp_destroy_interface(ppp); 1386 } 1387 1388 static const struct net_device_ops ppp_netdev_ops = { 1389 .ndo_init = ppp_dev_init, 1390 .ndo_uninit = ppp_dev_uninit, 1391 .ndo_start_xmit = ppp_start_xmit, 1392 .ndo_do_ioctl = ppp_net_ioctl, 1393 .ndo_get_stats64 = ppp_get_stats64, 1394 }; 1395 1396 static struct device_type ppp_type = { 1397 .name = "ppp", 1398 }; 1399 1400 static void ppp_setup(struct net_device *dev) 1401 { 1402 dev->netdev_ops = &ppp_netdev_ops; 1403 SET_NETDEV_DEVTYPE(dev, &ppp_type); 1404 1405 dev->features |= NETIF_F_LLTX; 1406 1407 dev->hard_header_len = PPP_HDRLEN; 1408 dev->mtu = PPP_MRU; 1409 dev->addr_len = 0; 1410 dev->tx_queue_len = 3; 1411 dev->type = ARPHRD_PPP; 1412 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 1413 dev->priv_destructor = ppp_dev_priv_destructor; 1414 netif_keep_dst(dev); 1415 } 1416 1417 /* 1418 * Transmit-side routines. 1419 */ 1420 1421 /* Called to do any work queued up on the transmit side that can now be done */ 1422 static void __ppp_xmit_process(struct ppp *ppp) 1423 { 1424 struct sk_buff *skb; 1425 1426 ppp_xmit_lock(ppp); 1427 if (!ppp->closing) { 1428 ppp_push(ppp); 1429 while (!ppp->xmit_pending && 1430 (skb = skb_dequeue(&ppp->file.xq))) 1431 ppp_send_frame(ppp, skb); 1432 /* If there's no work left to do, tell the core net 1433 code that we can accept some more. */ 1434 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq)) 1435 netif_wake_queue(ppp->dev); 1436 else 1437 netif_stop_queue(ppp->dev); 1438 } 1439 ppp_xmit_unlock(ppp); 1440 } 1441 1442 static void ppp_xmit_process(struct ppp *ppp) 1443 { 1444 local_bh_disable(); 1445 1446 if (unlikely(*this_cpu_ptr(ppp->xmit_recursion))) 1447 goto err; 1448 1449 (*this_cpu_ptr(ppp->xmit_recursion))++; 1450 __ppp_xmit_process(ppp); 1451 (*this_cpu_ptr(ppp->xmit_recursion))--; 1452 1453 local_bh_enable(); 1454 1455 return; 1456 1457 err: 1458 local_bh_enable(); 1459 1460 if (net_ratelimit()) 1461 netdev_err(ppp->dev, "recursion detected\n"); 1462 } 1463 1464 static inline struct sk_buff * 1465 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) 1466 { 1467 struct sk_buff *new_skb; 1468 int len; 1469 int new_skb_size = ppp->dev->mtu + 1470 ppp->xcomp->comp_extra + ppp->dev->hard_header_len; 1471 int compressor_skb_size = ppp->dev->mtu + 1472 ppp->xcomp->comp_extra + PPP_HDRLEN; 1473 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC); 1474 if (!new_skb) { 1475 if (net_ratelimit()) 1476 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n"); 1477 return NULL; 1478 } 1479 if (ppp->dev->hard_header_len > PPP_HDRLEN) 1480 skb_reserve(new_skb, 1481 ppp->dev->hard_header_len - PPP_HDRLEN); 1482 1483 /* compressor still expects A/C bytes in hdr */ 1484 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, 1485 new_skb->data, skb->len + 2, 1486 compressor_skb_size); 1487 if (len > 0 && (ppp->flags & SC_CCP_UP)) { 1488 consume_skb(skb); 1489 skb = new_skb; 1490 skb_put(skb, len); 1491 skb_pull(skb, 2); /* pull off A/C bytes */ 1492 } else if (len == 0) { 1493 /* didn't compress, or CCP not up yet */ 1494 consume_skb(new_skb); 1495 new_skb = skb; 1496 } else { 1497 /* 1498 * (len < 0) 1499 * MPPE requires that we do not send unencrypted 1500 * frames. The compressor will return -1 if we 1501 * should drop the frame. We cannot simply test 1502 * the compress_proto because MPPE and MPPC share 1503 * the same number. 1504 */ 1505 if (net_ratelimit()) 1506 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n"); 1507 kfree_skb(skb); 1508 consume_skb(new_skb); 1509 new_skb = NULL; 1510 } 1511 return new_skb; 1512 } 1513 1514 /* 1515 * Compress and send a frame. 1516 * The caller should have locked the xmit path, 1517 * and xmit_pending should be 0. 1518 */ 1519 static void 1520 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) 1521 { 1522 int proto = PPP_PROTO(skb); 1523 struct sk_buff *new_skb; 1524 int len; 1525 unsigned char *cp; 1526 1527 if (proto < 0x8000) { 1528 #ifdef CONFIG_PPP_FILTER 1529 /* check if we should pass this packet */ 1530 /* the filter instructions are constructed assuming 1531 a four-byte PPP header on each packet */ 1532 *(u8 *)skb_push(skb, 2) = 1; 1533 if (ppp->pass_filter && 1534 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 1535 if (ppp->debug & 1) 1536 netdev_printk(KERN_DEBUG, ppp->dev, 1537 "PPP: outbound frame " 1538 "not passed\n"); 1539 kfree_skb(skb); 1540 return; 1541 } 1542 /* if this packet passes the active filter, record the time */ 1543 if (!(ppp->active_filter && 1544 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 1545 ppp->last_xmit = jiffies; 1546 skb_pull(skb, 2); 1547 #else 1548 /* for data packets, record the time */ 1549 ppp->last_xmit = jiffies; 1550 #endif /* CONFIG_PPP_FILTER */ 1551 } 1552 1553 ++ppp->stats64.tx_packets; 1554 ppp->stats64.tx_bytes += skb->len - 2; 1555 1556 switch (proto) { 1557 case PPP_IP: 1558 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0) 1559 break; 1560 /* try to do VJ TCP header compression */ 1561 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2, 1562 GFP_ATOMIC); 1563 if (!new_skb) { 1564 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n"); 1565 goto drop; 1566 } 1567 skb_reserve(new_skb, ppp->dev->hard_header_len - 2); 1568 cp = skb->data + 2; 1569 len = slhc_compress(ppp->vj, cp, skb->len - 2, 1570 new_skb->data + 2, &cp, 1571 !(ppp->flags & SC_NO_TCP_CCID)); 1572 if (cp == skb->data + 2) { 1573 /* didn't compress */ 1574 consume_skb(new_skb); 1575 } else { 1576 if (cp[0] & SL_TYPE_COMPRESSED_TCP) { 1577 proto = PPP_VJC_COMP; 1578 cp[0] &= ~SL_TYPE_COMPRESSED_TCP; 1579 } else { 1580 proto = PPP_VJC_UNCOMP; 1581 cp[0] = skb->data[2]; 1582 } 1583 consume_skb(skb); 1584 skb = new_skb; 1585 cp = skb_put(skb, len + 2); 1586 cp[0] = 0; 1587 cp[1] = proto; 1588 } 1589 break; 1590 1591 case PPP_CCP: 1592 /* peek at outbound CCP frames */ 1593 ppp_ccp_peek(ppp, skb, 0); 1594 break; 1595 } 1596 1597 /* try to do packet compression */ 1598 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state && 1599 proto != PPP_LCP && proto != PPP_CCP) { 1600 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) { 1601 if (net_ratelimit()) 1602 netdev_err(ppp->dev, 1603 "ppp: compression required but " 1604 "down - pkt dropped.\n"); 1605 goto drop; 1606 } 1607 skb = pad_compress_skb(ppp, skb); 1608 if (!skb) 1609 goto drop; 1610 } 1611 1612 /* 1613 * If we are waiting for traffic (demand dialling), 1614 * queue it up for pppd to receive. 1615 */ 1616 if (ppp->flags & SC_LOOP_TRAFFIC) { 1617 if (ppp->file.rq.qlen > PPP_MAX_RQLEN) 1618 goto drop; 1619 skb_queue_tail(&ppp->file.rq, skb); 1620 wake_up_interruptible(&ppp->file.rwait); 1621 return; 1622 } 1623 1624 ppp->xmit_pending = skb; 1625 ppp_push(ppp); 1626 return; 1627 1628 drop: 1629 kfree_skb(skb); 1630 ++ppp->dev->stats.tx_errors; 1631 } 1632 1633 /* 1634 * Try to send the frame in xmit_pending. 1635 * The caller should have the xmit path locked. 1636 */ 1637 static void 1638 ppp_push(struct ppp *ppp) 1639 { 1640 struct list_head *list; 1641 struct channel *pch; 1642 struct sk_buff *skb = ppp->xmit_pending; 1643 1644 if (!skb) 1645 return; 1646 1647 list = &ppp->channels; 1648 if (list_empty(list)) { 1649 /* nowhere to send the packet, just drop it */ 1650 ppp->xmit_pending = NULL; 1651 kfree_skb(skb); 1652 return; 1653 } 1654 1655 if ((ppp->flags & SC_MULTILINK) == 0) { 1656 /* not doing multilink: send it down the first channel */ 1657 list = list->next; 1658 pch = list_entry(list, struct channel, clist); 1659 1660 spin_lock(&pch->downl); 1661 if (pch->chan) { 1662 if (pch->chan->ops->start_xmit(pch->chan, skb)) 1663 ppp->xmit_pending = NULL; 1664 } else { 1665 /* channel got unregistered */ 1666 kfree_skb(skb); 1667 ppp->xmit_pending = NULL; 1668 } 1669 spin_unlock(&pch->downl); 1670 return; 1671 } 1672 1673 #ifdef CONFIG_PPP_MULTILINK 1674 /* Multilink: fragment the packet over as many links 1675 as can take the packet at the moment. */ 1676 if (!ppp_mp_explode(ppp, skb)) 1677 return; 1678 #endif /* CONFIG_PPP_MULTILINK */ 1679 1680 ppp->xmit_pending = NULL; 1681 kfree_skb(skb); 1682 } 1683 1684 #ifdef CONFIG_PPP_MULTILINK 1685 static bool mp_protocol_compress __read_mostly = true; 1686 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR); 1687 MODULE_PARM_DESC(mp_protocol_compress, 1688 "compress protocol id in multilink fragments"); 1689 1690 /* 1691 * Divide a packet to be transmitted into fragments and 1692 * send them out the individual links. 1693 */ 1694 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb) 1695 { 1696 int len, totlen; 1697 int i, bits, hdrlen, mtu; 1698 int flen; 1699 int navail, nfree, nzero; 1700 int nbigger; 1701 int totspeed; 1702 int totfree; 1703 unsigned char *p, *q; 1704 struct list_head *list; 1705 struct channel *pch; 1706 struct sk_buff *frag; 1707 struct ppp_channel *chan; 1708 1709 totspeed = 0; /*total bitrate of the bundle*/ 1710 nfree = 0; /* # channels which have no packet already queued */ 1711 navail = 0; /* total # of usable channels (not deregistered) */ 1712 nzero = 0; /* number of channels with zero speed associated*/ 1713 totfree = 0; /*total # of channels available and 1714 *having no queued packets before 1715 *starting the fragmentation*/ 1716 1717 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1718 i = 0; 1719 list_for_each_entry(pch, &ppp->channels, clist) { 1720 if (pch->chan) { 1721 pch->avail = 1; 1722 navail++; 1723 pch->speed = pch->chan->speed; 1724 } else { 1725 pch->avail = 0; 1726 } 1727 if (pch->avail) { 1728 if (skb_queue_empty(&pch->file.xq) || 1729 !pch->had_frag) { 1730 if (pch->speed == 0) 1731 nzero++; 1732 else 1733 totspeed += pch->speed; 1734 1735 pch->avail = 2; 1736 ++nfree; 1737 ++totfree; 1738 } 1739 if (!pch->had_frag && i < ppp->nxchan) 1740 ppp->nxchan = i; 1741 } 1742 ++i; 1743 } 1744 /* 1745 * Don't start sending this packet unless at least half of 1746 * the channels are free. This gives much better TCP 1747 * performance if we have a lot of channels. 1748 */ 1749 if (nfree == 0 || nfree < navail / 2) 1750 return 0; /* can't take now, leave it in xmit_pending */ 1751 1752 /* Do protocol field compression */ 1753 p = skb->data; 1754 len = skb->len; 1755 if (*p == 0 && mp_protocol_compress) { 1756 ++p; 1757 --len; 1758 } 1759 1760 totlen = len; 1761 nbigger = len % nfree; 1762 1763 /* skip to the channel after the one we last used 1764 and start at that one */ 1765 list = &ppp->channels; 1766 for (i = 0; i < ppp->nxchan; ++i) { 1767 list = list->next; 1768 if (list == &ppp->channels) { 1769 i = 0; 1770 break; 1771 } 1772 } 1773 1774 /* create a fragment for each channel */ 1775 bits = B; 1776 while (len > 0) { 1777 list = list->next; 1778 if (list == &ppp->channels) { 1779 i = 0; 1780 continue; 1781 } 1782 pch = list_entry(list, struct channel, clist); 1783 ++i; 1784 if (!pch->avail) 1785 continue; 1786 1787 /* 1788 * Skip this channel if it has a fragment pending already and 1789 * we haven't given a fragment to all of the free channels. 1790 */ 1791 if (pch->avail == 1) { 1792 if (nfree > 0) 1793 continue; 1794 } else { 1795 pch->avail = 1; 1796 } 1797 1798 /* check the channel's mtu and whether it is still attached. */ 1799 spin_lock(&pch->downl); 1800 if (pch->chan == NULL) { 1801 /* can't use this channel, it's being deregistered */ 1802 if (pch->speed == 0) 1803 nzero--; 1804 else 1805 totspeed -= pch->speed; 1806 1807 spin_unlock(&pch->downl); 1808 pch->avail = 0; 1809 totlen = len; 1810 totfree--; 1811 nfree--; 1812 if (--navail == 0) 1813 break; 1814 continue; 1815 } 1816 1817 /* 1818 *if the channel speed is not set divide 1819 *the packet evenly among the free channels; 1820 *otherwise divide it according to the speed 1821 *of the channel we are going to transmit on 1822 */ 1823 flen = len; 1824 if (nfree > 0) { 1825 if (pch->speed == 0) { 1826 flen = len/nfree; 1827 if (nbigger > 0) { 1828 flen++; 1829 nbigger--; 1830 } 1831 } else { 1832 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) / 1833 ((totspeed*totfree)/pch->speed)) - hdrlen; 1834 if (nbigger > 0) { 1835 flen += ((totfree - nzero)*pch->speed)/totspeed; 1836 nbigger -= ((totfree - nzero)*pch->speed)/ 1837 totspeed; 1838 } 1839 } 1840 nfree--; 1841 } 1842 1843 /* 1844 *check if we are on the last channel or 1845 *we exceded the length of the data to 1846 *fragment 1847 */ 1848 if ((nfree <= 0) || (flen > len)) 1849 flen = len; 1850 /* 1851 *it is not worth to tx on slow channels: 1852 *in that case from the resulting flen according to the 1853 *above formula will be equal or less than zero. 1854 *Skip the channel in this case 1855 */ 1856 if (flen <= 0) { 1857 pch->avail = 2; 1858 spin_unlock(&pch->downl); 1859 continue; 1860 } 1861 1862 /* 1863 * hdrlen includes the 2-byte PPP protocol field, but the 1864 * MTU counts only the payload excluding the protocol field. 1865 * (RFC1661 Section 2) 1866 */ 1867 mtu = pch->chan->mtu - (hdrlen - 2); 1868 if (mtu < 4) 1869 mtu = 4; 1870 if (flen > mtu) 1871 flen = mtu; 1872 if (flen == len) 1873 bits |= E; 1874 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC); 1875 if (!frag) 1876 goto noskb; 1877 q = skb_put(frag, flen + hdrlen); 1878 1879 /* make the MP header */ 1880 put_unaligned_be16(PPP_MP, q); 1881 if (ppp->flags & SC_MP_XSHORTSEQ) { 1882 q[2] = bits + ((ppp->nxseq >> 8) & 0xf); 1883 q[3] = ppp->nxseq; 1884 } else { 1885 q[2] = bits; 1886 q[3] = ppp->nxseq >> 16; 1887 q[4] = ppp->nxseq >> 8; 1888 q[5] = ppp->nxseq; 1889 } 1890 1891 memcpy(q + hdrlen, p, flen); 1892 1893 /* try to send it down the channel */ 1894 chan = pch->chan; 1895 if (!skb_queue_empty(&pch->file.xq) || 1896 !chan->ops->start_xmit(chan, frag)) 1897 skb_queue_tail(&pch->file.xq, frag); 1898 pch->had_frag = 1; 1899 p += flen; 1900 len -= flen; 1901 ++ppp->nxseq; 1902 bits = 0; 1903 spin_unlock(&pch->downl); 1904 } 1905 ppp->nxchan = i; 1906 1907 return 1; 1908 1909 noskb: 1910 spin_unlock(&pch->downl); 1911 if (ppp->debug & 1) 1912 netdev_err(ppp->dev, "PPP: no memory (fragment)\n"); 1913 ++ppp->dev->stats.tx_errors; 1914 ++ppp->nxseq; 1915 return 1; /* abandon the frame */ 1916 } 1917 #endif /* CONFIG_PPP_MULTILINK */ 1918 1919 /* Try to send data out on a channel */ 1920 static void __ppp_channel_push(struct channel *pch) 1921 { 1922 struct sk_buff *skb; 1923 struct ppp *ppp; 1924 1925 spin_lock(&pch->downl); 1926 if (pch->chan) { 1927 while (!skb_queue_empty(&pch->file.xq)) { 1928 skb = skb_dequeue(&pch->file.xq); 1929 if (!pch->chan->ops->start_xmit(pch->chan, skb)) { 1930 /* put the packet back and try again later */ 1931 skb_queue_head(&pch->file.xq, skb); 1932 break; 1933 } 1934 } 1935 } else { 1936 /* channel got deregistered */ 1937 skb_queue_purge(&pch->file.xq); 1938 } 1939 spin_unlock(&pch->downl); 1940 /* see if there is anything from the attached unit to be sent */ 1941 if (skb_queue_empty(&pch->file.xq)) { 1942 ppp = pch->ppp; 1943 if (ppp) 1944 __ppp_xmit_process(ppp); 1945 } 1946 } 1947 1948 static void ppp_channel_push(struct channel *pch) 1949 { 1950 read_lock_bh(&pch->upl); 1951 if (pch->ppp) { 1952 (*this_cpu_ptr(pch->ppp->xmit_recursion))++; 1953 __ppp_channel_push(pch); 1954 (*this_cpu_ptr(pch->ppp->xmit_recursion))--; 1955 } else { 1956 __ppp_channel_push(pch); 1957 } 1958 read_unlock_bh(&pch->upl); 1959 } 1960 1961 /* 1962 * Receive-side routines. 1963 */ 1964 1965 struct ppp_mp_skb_parm { 1966 u32 sequence; 1967 u8 BEbits; 1968 }; 1969 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb)) 1970 1971 static inline void 1972 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1973 { 1974 ppp_recv_lock(ppp); 1975 if (!ppp->closing) 1976 ppp_receive_frame(ppp, skb, pch); 1977 else 1978 kfree_skb(skb); 1979 ppp_recv_unlock(ppp); 1980 } 1981 1982 void 1983 ppp_input(struct ppp_channel *chan, struct sk_buff *skb) 1984 { 1985 struct channel *pch = chan->ppp; 1986 int proto; 1987 1988 if (!pch) { 1989 kfree_skb(skb); 1990 return; 1991 } 1992 1993 read_lock_bh(&pch->upl); 1994 if (!pskb_may_pull(skb, 2)) { 1995 kfree_skb(skb); 1996 if (pch->ppp) { 1997 ++pch->ppp->dev->stats.rx_length_errors; 1998 ppp_receive_error(pch->ppp); 1999 } 2000 goto done; 2001 } 2002 2003 proto = PPP_PROTO(skb); 2004 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) { 2005 /* put it on the channel queue */ 2006 skb_queue_tail(&pch->file.rq, skb); 2007 /* drop old frames if queue too long */ 2008 while (pch->file.rq.qlen > PPP_MAX_RQLEN && 2009 (skb = skb_dequeue(&pch->file.rq))) 2010 kfree_skb(skb); 2011 wake_up_interruptible(&pch->file.rwait); 2012 } else { 2013 ppp_do_recv(pch->ppp, skb, pch); 2014 } 2015 2016 done: 2017 read_unlock_bh(&pch->upl); 2018 } 2019 2020 /* Put a 0-length skb in the receive queue as an error indication */ 2021 void 2022 ppp_input_error(struct ppp_channel *chan, int code) 2023 { 2024 struct channel *pch = chan->ppp; 2025 struct sk_buff *skb; 2026 2027 if (!pch) 2028 return; 2029 2030 read_lock_bh(&pch->upl); 2031 if (pch->ppp) { 2032 skb = alloc_skb(0, GFP_ATOMIC); 2033 if (skb) { 2034 skb->len = 0; /* probably unnecessary */ 2035 skb->cb[0] = code; 2036 ppp_do_recv(pch->ppp, skb, pch); 2037 } 2038 } 2039 read_unlock_bh(&pch->upl); 2040 } 2041 2042 /* 2043 * We come in here to process a received frame. 2044 * The receive side of the ppp unit is locked. 2045 */ 2046 static void 2047 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2048 { 2049 /* note: a 0-length skb is used as an error indication */ 2050 if (skb->len > 0) { 2051 skb_checksum_complete_unset(skb); 2052 #ifdef CONFIG_PPP_MULTILINK 2053 /* XXX do channel-level decompression here */ 2054 if (PPP_PROTO(skb) == PPP_MP) 2055 ppp_receive_mp_frame(ppp, skb, pch); 2056 else 2057 #endif /* CONFIG_PPP_MULTILINK */ 2058 ppp_receive_nonmp_frame(ppp, skb); 2059 } else { 2060 kfree_skb(skb); 2061 ppp_receive_error(ppp); 2062 } 2063 } 2064 2065 static void 2066 ppp_receive_error(struct ppp *ppp) 2067 { 2068 ++ppp->dev->stats.rx_errors; 2069 if (ppp->vj) 2070 slhc_toss(ppp->vj); 2071 } 2072 2073 static void 2074 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) 2075 { 2076 struct sk_buff *ns; 2077 int proto, len, npi; 2078 2079 /* 2080 * Decompress the frame, if compressed. 2081 * Note that some decompressors need to see uncompressed frames 2082 * that come in as well as compressed frames. 2083 */ 2084 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) && 2085 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0) 2086 skb = ppp_decompress_frame(ppp, skb); 2087 2088 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR) 2089 goto err; 2090 2091 proto = PPP_PROTO(skb); 2092 switch (proto) { 2093 case PPP_VJC_COMP: 2094 /* decompress VJ compressed packets */ 2095 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 2096 goto err; 2097 2098 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) { 2099 /* copy to a new sk_buff with more tailroom */ 2100 ns = dev_alloc_skb(skb->len + 128); 2101 if (!ns) { 2102 netdev_err(ppp->dev, "PPP: no memory " 2103 "(VJ decomp)\n"); 2104 goto err; 2105 } 2106 skb_reserve(ns, 2); 2107 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len); 2108 consume_skb(skb); 2109 skb = ns; 2110 } 2111 else 2112 skb->ip_summed = CHECKSUM_NONE; 2113 2114 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2); 2115 if (len <= 0) { 2116 netdev_printk(KERN_DEBUG, ppp->dev, 2117 "PPP: VJ decompression error\n"); 2118 goto err; 2119 } 2120 len += 2; 2121 if (len > skb->len) 2122 skb_put(skb, len - skb->len); 2123 else if (len < skb->len) 2124 skb_trim(skb, len); 2125 proto = PPP_IP; 2126 break; 2127 2128 case PPP_VJC_UNCOMP: 2129 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 2130 goto err; 2131 2132 /* Until we fix the decompressor need to make sure 2133 * data portion is linear. 2134 */ 2135 if (!pskb_may_pull(skb, skb->len)) 2136 goto err; 2137 2138 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) { 2139 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n"); 2140 goto err; 2141 } 2142 proto = PPP_IP; 2143 break; 2144 2145 case PPP_CCP: 2146 ppp_ccp_peek(ppp, skb, 1); 2147 break; 2148 } 2149 2150 ++ppp->stats64.rx_packets; 2151 ppp->stats64.rx_bytes += skb->len - 2; 2152 2153 npi = proto_to_npindex(proto); 2154 if (npi < 0) { 2155 /* control or unknown frame - pass it to pppd */ 2156 skb_queue_tail(&ppp->file.rq, skb); 2157 /* limit queue length by dropping old frames */ 2158 while (ppp->file.rq.qlen > PPP_MAX_RQLEN && 2159 (skb = skb_dequeue(&ppp->file.rq))) 2160 kfree_skb(skb); 2161 /* wake up any process polling or blocking on read */ 2162 wake_up_interruptible(&ppp->file.rwait); 2163 2164 } else { 2165 /* network protocol frame - give it to the kernel */ 2166 2167 #ifdef CONFIG_PPP_FILTER 2168 /* check if the packet passes the pass and active filters */ 2169 /* the filter instructions are constructed assuming 2170 a four-byte PPP header on each packet */ 2171 if (ppp->pass_filter || ppp->active_filter) { 2172 if (skb_unclone(skb, GFP_ATOMIC)) 2173 goto err; 2174 2175 *(u8 *)skb_push(skb, 2) = 0; 2176 if (ppp->pass_filter && 2177 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 2178 if (ppp->debug & 1) 2179 netdev_printk(KERN_DEBUG, ppp->dev, 2180 "PPP: inbound frame " 2181 "not passed\n"); 2182 kfree_skb(skb); 2183 return; 2184 } 2185 if (!(ppp->active_filter && 2186 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 2187 ppp->last_recv = jiffies; 2188 __skb_pull(skb, 2); 2189 } else 2190 #endif /* CONFIG_PPP_FILTER */ 2191 ppp->last_recv = jiffies; 2192 2193 if ((ppp->dev->flags & IFF_UP) == 0 || 2194 ppp->npmode[npi] != NPMODE_PASS) { 2195 kfree_skb(skb); 2196 } else { 2197 /* chop off protocol */ 2198 skb_pull_rcsum(skb, 2); 2199 skb->dev = ppp->dev; 2200 skb->protocol = htons(npindex_to_ethertype[npi]); 2201 skb_reset_mac_header(skb); 2202 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, 2203 dev_net(ppp->dev))); 2204 netif_rx(skb); 2205 } 2206 } 2207 return; 2208 2209 err: 2210 kfree_skb(skb); 2211 ppp_receive_error(ppp); 2212 } 2213 2214 static struct sk_buff * 2215 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb) 2216 { 2217 int proto = PPP_PROTO(skb); 2218 struct sk_buff *ns; 2219 int len; 2220 2221 /* Until we fix all the decompressor's need to make sure 2222 * data portion is linear. 2223 */ 2224 if (!pskb_may_pull(skb, skb->len)) 2225 goto err; 2226 2227 if (proto == PPP_COMP) { 2228 int obuff_size; 2229 2230 switch(ppp->rcomp->compress_proto) { 2231 case CI_MPPE: 2232 obuff_size = ppp->mru + PPP_HDRLEN + 1; 2233 break; 2234 default: 2235 obuff_size = ppp->mru + PPP_HDRLEN; 2236 break; 2237 } 2238 2239 ns = dev_alloc_skb(obuff_size); 2240 if (!ns) { 2241 netdev_err(ppp->dev, "ppp_decompress_frame: " 2242 "no memory\n"); 2243 goto err; 2244 } 2245 /* the decompressor still expects the A/C bytes in the hdr */ 2246 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2, 2247 skb->len + 2, ns->data, obuff_size); 2248 if (len < 0) { 2249 /* Pass the compressed frame to pppd as an 2250 error indication. */ 2251 if (len == DECOMP_FATALERROR) 2252 ppp->rstate |= SC_DC_FERROR; 2253 kfree_skb(ns); 2254 goto err; 2255 } 2256 2257 consume_skb(skb); 2258 skb = ns; 2259 skb_put(skb, len); 2260 skb_pull(skb, 2); /* pull off the A/C bytes */ 2261 2262 } else { 2263 /* Uncompressed frame - pass to decompressor so it 2264 can update its dictionary if necessary. */ 2265 if (ppp->rcomp->incomp) 2266 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2, 2267 skb->len + 2); 2268 } 2269 2270 return skb; 2271 2272 err: 2273 ppp->rstate |= SC_DC_ERROR; 2274 ppp_receive_error(ppp); 2275 return skb; 2276 } 2277 2278 #ifdef CONFIG_PPP_MULTILINK 2279 /* 2280 * Receive a multilink frame. 2281 * We put it on the reconstruction queue and then pull off 2282 * as many completed frames as we can. 2283 */ 2284 static void 2285 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2286 { 2287 u32 mask, seq; 2288 struct channel *ch; 2289 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 2290 2291 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0) 2292 goto err; /* no good, throw it away */ 2293 2294 /* Decode sequence number and begin/end bits */ 2295 if (ppp->flags & SC_MP_SHORTSEQ) { 2296 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3]; 2297 mask = 0xfff; 2298 } else { 2299 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5]; 2300 mask = 0xffffff; 2301 } 2302 PPP_MP_CB(skb)->BEbits = skb->data[2]; 2303 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */ 2304 2305 /* 2306 * Do protocol ID decompression on the first fragment of each packet. 2307 */ 2308 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1)) 2309 *(u8 *)skb_push(skb, 1) = 0; 2310 2311 /* 2312 * Expand sequence number to 32 bits, making it as close 2313 * as possible to ppp->minseq. 2314 */ 2315 seq |= ppp->minseq & ~mask; 2316 if ((int)(ppp->minseq - seq) > (int)(mask >> 1)) 2317 seq += mask + 1; 2318 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1)) 2319 seq -= mask + 1; /* should never happen */ 2320 PPP_MP_CB(skb)->sequence = seq; 2321 pch->lastseq = seq; 2322 2323 /* 2324 * If this packet comes before the next one we were expecting, 2325 * drop it. 2326 */ 2327 if (seq_before(seq, ppp->nextseq)) { 2328 kfree_skb(skb); 2329 ++ppp->dev->stats.rx_dropped; 2330 ppp_receive_error(ppp); 2331 return; 2332 } 2333 2334 /* 2335 * Reevaluate minseq, the minimum over all channels of the 2336 * last sequence number received on each channel. Because of 2337 * the increasing sequence number rule, we know that any fragment 2338 * before `minseq' which hasn't arrived is never going to arrive. 2339 * The list of channels can't change because we have the receive 2340 * side of the ppp unit locked. 2341 */ 2342 list_for_each_entry(ch, &ppp->channels, clist) { 2343 if (seq_before(ch->lastseq, seq)) 2344 seq = ch->lastseq; 2345 } 2346 if (seq_before(ppp->minseq, seq)) 2347 ppp->minseq = seq; 2348 2349 /* Put the fragment on the reconstruction queue */ 2350 ppp_mp_insert(ppp, skb); 2351 2352 /* If the queue is getting long, don't wait any longer for packets 2353 before the start of the queue. */ 2354 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) { 2355 struct sk_buff *mskb = skb_peek(&ppp->mrq); 2356 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence)) 2357 ppp->minseq = PPP_MP_CB(mskb)->sequence; 2358 } 2359 2360 /* Pull completed packets off the queue and receive them. */ 2361 while ((skb = ppp_mp_reconstruct(ppp))) { 2362 if (pskb_may_pull(skb, 2)) 2363 ppp_receive_nonmp_frame(ppp, skb); 2364 else { 2365 ++ppp->dev->stats.rx_length_errors; 2366 kfree_skb(skb); 2367 ppp_receive_error(ppp); 2368 } 2369 } 2370 2371 return; 2372 2373 err: 2374 kfree_skb(skb); 2375 ppp_receive_error(ppp); 2376 } 2377 2378 /* 2379 * Insert a fragment on the MP reconstruction queue. 2380 * The queue is ordered by increasing sequence number. 2381 */ 2382 static void 2383 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb) 2384 { 2385 struct sk_buff *p; 2386 struct sk_buff_head *list = &ppp->mrq; 2387 u32 seq = PPP_MP_CB(skb)->sequence; 2388 2389 /* N.B. we don't need to lock the list lock because we have the 2390 ppp unit receive-side lock. */ 2391 skb_queue_walk(list, p) { 2392 if (seq_before(seq, PPP_MP_CB(p)->sequence)) 2393 break; 2394 } 2395 __skb_queue_before(list, p, skb); 2396 } 2397 2398 /* 2399 * Reconstruct a packet from the MP fragment queue. 2400 * We go through increasing sequence numbers until we find a 2401 * complete packet, or we get to the sequence number for a fragment 2402 * which hasn't arrived but might still do so. 2403 */ 2404 static struct sk_buff * 2405 ppp_mp_reconstruct(struct ppp *ppp) 2406 { 2407 u32 seq = ppp->nextseq; 2408 u32 minseq = ppp->minseq; 2409 struct sk_buff_head *list = &ppp->mrq; 2410 struct sk_buff *p, *tmp; 2411 struct sk_buff *head, *tail; 2412 struct sk_buff *skb = NULL; 2413 int lost = 0, len = 0; 2414 2415 if (ppp->mrru == 0) /* do nothing until mrru is set */ 2416 return NULL; 2417 head = list->next; 2418 tail = NULL; 2419 skb_queue_walk_safe(list, p, tmp) { 2420 again: 2421 if (seq_before(PPP_MP_CB(p)->sequence, seq)) { 2422 /* this can't happen, anyway ignore the skb */ 2423 netdev_err(ppp->dev, "ppp_mp_reconstruct bad " 2424 "seq %u < %u\n", 2425 PPP_MP_CB(p)->sequence, seq); 2426 __skb_unlink(p, list); 2427 kfree_skb(p); 2428 continue; 2429 } 2430 if (PPP_MP_CB(p)->sequence != seq) { 2431 u32 oldseq; 2432 /* Fragment `seq' is missing. If it is after 2433 minseq, it might arrive later, so stop here. */ 2434 if (seq_after(seq, minseq)) 2435 break; 2436 /* Fragment `seq' is lost, keep going. */ 2437 lost = 1; 2438 oldseq = seq; 2439 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)? 2440 minseq + 1: PPP_MP_CB(p)->sequence; 2441 2442 if (ppp->debug & 1) 2443 netdev_printk(KERN_DEBUG, ppp->dev, 2444 "lost frag %u..%u\n", 2445 oldseq, seq-1); 2446 2447 goto again; 2448 } 2449 2450 /* 2451 * At this point we know that all the fragments from 2452 * ppp->nextseq to seq are either present or lost. 2453 * Also, there are no complete packets in the queue 2454 * that have no missing fragments and end before this 2455 * fragment. 2456 */ 2457 2458 /* B bit set indicates this fragment starts a packet */ 2459 if (PPP_MP_CB(p)->BEbits & B) { 2460 head = p; 2461 lost = 0; 2462 len = 0; 2463 } 2464 2465 len += p->len; 2466 2467 /* Got a complete packet yet? */ 2468 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) && 2469 (PPP_MP_CB(head)->BEbits & B)) { 2470 if (len > ppp->mrru + 2) { 2471 ++ppp->dev->stats.rx_length_errors; 2472 netdev_printk(KERN_DEBUG, ppp->dev, 2473 "PPP: reconstructed packet" 2474 " is too long (%d)\n", len); 2475 } else { 2476 tail = p; 2477 break; 2478 } 2479 ppp->nextseq = seq + 1; 2480 } 2481 2482 /* 2483 * If this is the ending fragment of a packet, 2484 * and we haven't found a complete valid packet yet, 2485 * we can discard up to and including this fragment. 2486 */ 2487 if (PPP_MP_CB(p)->BEbits & E) { 2488 struct sk_buff *tmp2; 2489 2490 skb_queue_reverse_walk_from_safe(list, p, tmp2) { 2491 if (ppp->debug & 1) 2492 netdev_printk(KERN_DEBUG, ppp->dev, 2493 "discarding frag %u\n", 2494 PPP_MP_CB(p)->sequence); 2495 __skb_unlink(p, list); 2496 kfree_skb(p); 2497 } 2498 head = skb_peek(list); 2499 if (!head) 2500 break; 2501 } 2502 ++seq; 2503 } 2504 2505 /* If we have a complete packet, copy it all into one skb. */ 2506 if (tail != NULL) { 2507 /* If we have discarded any fragments, 2508 signal a receive error. */ 2509 if (PPP_MP_CB(head)->sequence != ppp->nextseq) { 2510 skb_queue_walk_safe(list, p, tmp) { 2511 if (p == head) 2512 break; 2513 if (ppp->debug & 1) 2514 netdev_printk(KERN_DEBUG, ppp->dev, 2515 "discarding frag %u\n", 2516 PPP_MP_CB(p)->sequence); 2517 __skb_unlink(p, list); 2518 kfree_skb(p); 2519 } 2520 2521 if (ppp->debug & 1) 2522 netdev_printk(KERN_DEBUG, ppp->dev, 2523 " missed pkts %u..%u\n", 2524 ppp->nextseq, 2525 PPP_MP_CB(head)->sequence-1); 2526 ++ppp->dev->stats.rx_dropped; 2527 ppp_receive_error(ppp); 2528 } 2529 2530 skb = head; 2531 if (head != tail) { 2532 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list; 2533 p = skb_queue_next(list, head); 2534 __skb_unlink(skb, list); 2535 skb_queue_walk_from_safe(list, p, tmp) { 2536 __skb_unlink(p, list); 2537 *fragpp = p; 2538 p->next = NULL; 2539 fragpp = &p->next; 2540 2541 skb->len += p->len; 2542 skb->data_len += p->len; 2543 skb->truesize += p->truesize; 2544 2545 if (p == tail) 2546 break; 2547 } 2548 } else { 2549 __skb_unlink(skb, list); 2550 } 2551 2552 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1; 2553 } 2554 2555 return skb; 2556 } 2557 #endif /* CONFIG_PPP_MULTILINK */ 2558 2559 /* 2560 * Channel interface. 2561 */ 2562 2563 /* Create a new, unattached ppp channel. */ 2564 int ppp_register_channel(struct ppp_channel *chan) 2565 { 2566 return ppp_register_net_channel(current->nsproxy->net_ns, chan); 2567 } 2568 2569 /* Create a new, unattached ppp channel for specified net. */ 2570 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan) 2571 { 2572 struct channel *pch; 2573 struct ppp_net *pn; 2574 2575 pch = kzalloc(sizeof(struct channel), GFP_KERNEL); 2576 if (!pch) 2577 return -ENOMEM; 2578 2579 pn = ppp_pernet(net); 2580 2581 pch->ppp = NULL; 2582 pch->chan = chan; 2583 pch->chan_net = get_net(net); 2584 chan->ppp = pch; 2585 init_ppp_file(&pch->file, CHANNEL); 2586 pch->file.hdrlen = chan->hdrlen; 2587 #ifdef CONFIG_PPP_MULTILINK 2588 pch->lastseq = -1; 2589 #endif /* CONFIG_PPP_MULTILINK */ 2590 init_rwsem(&pch->chan_sem); 2591 spin_lock_init(&pch->downl); 2592 rwlock_init(&pch->upl); 2593 2594 spin_lock_bh(&pn->all_channels_lock); 2595 pch->file.index = ++pn->last_channel_index; 2596 list_add(&pch->list, &pn->new_channels); 2597 atomic_inc(&channel_count); 2598 spin_unlock_bh(&pn->all_channels_lock); 2599 2600 return 0; 2601 } 2602 2603 /* 2604 * Return the index of a channel. 2605 */ 2606 int ppp_channel_index(struct ppp_channel *chan) 2607 { 2608 struct channel *pch = chan->ppp; 2609 2610 if (pch) 2611 return pch->file.index; 2612 return -1; 2613 } 2614 2615 /* 2616 * Return the PPP unit number to which a channel is connected. 2617 */ 2618 int ppp_unit_number(struct ppp_channel *chan) 2619 { 2620 struct channel *pch = chan->ppp; 2621 int unit = -1; 2622 2623 if (pch) { 2624 read_lock_bh(&pch->upl); 2625 if (pch->ppp) 2626 unit = pch->ppp->file.index; 2627 read_unlock_bh(&pch->upl); 2628 } 2629 return unit; 2630 } 2631 2632 /* 2633 * Return the PPP device interface name of a channel. 2634 */ 2635 char *ppp_dev_name(struct ppp_channel *chan) 2636 { 2637 struct channel *pch = chan->ppp; 2638 char *name = NULL; 2639 2640 if (pch) { 2641 read_lock_bh(&pch->upl); 2642 if (pch->ppp && pch->ppp->dev) 2643 name = pch->ppp->dev->name; 2644 read_unlock_bh(&pch->upl); 2645 } 2646 return name; 2647 } 2648 2649 2650 /* 2651 * Disconnect a channel from the generic layer. 2652 * This must be called in process context. 2653 */ 2654 void 2655 ppp_unregister_channel(struct ppp_channel *chan) 2656 { 2657 struct channel *pch = chan->ppp; 2658 struct ppp_net *pn; 2659 2660 if (!pch) 2661 return; /* should never happen */ 2662 2663 chan->ppp = NULL; 2664 2665 /* 2666 * This ensures that we have returned from any calls into the 2667 * the channel's start_xmit or ioctl routine before we proceed. 2668 */ 2669 down_write(&pch->chan_sem); 2670 spin_lock_bh(&pch->downl); 2671 pch->chan = NULL; 2672 spin_unlock_bh(&pch->downl); 2673 up_write(&pch->chan_sem); 2674 ppp_disconnect_channel(pch); 2675 2676 pn = ppp_pernet(pch->chan_net); 2677 spin_lock_bh(&pn->all_channels_lock); 2678 list_del(&pch->list); 2679 spin_unlock_bh(&pn->all_channels_lock); 2680 2681 pch->file.dead = 1; 2682 wake_up_interruptible(&pch->file.rwait); 2683 if (refcount_dec_and_test(&pch->file.refcnt)) 2684 ppp_destroy_channel(pch); 2685 } 2686 2687 /* 2688 * Callback from a channel when it can accept more to transmit. 2689 * This should be called at BH/softirq level, not interrupt level. 2690 */ 2691 void 2692 ppp_output_wakeup(struct ppp_channel *chan) 2693 { 2694 struct channel *pch = chan->ppp; 2695 2696 if (!pch) 2697 return; 2698 ppp_channel_push(pch); 2699 } 2700 2701 /* 2702 * Compression control. 2703 */ 2704 2705 /* Process the PPPIOCSCOMPRESS ioctl. */ 2706 static int 2707 ppp_set_compress(struct ppp *ppp, unsigned long arg) 2708 { 2709 int err; 2710 struct compressor *cp, *ocomp; 2711 struct ppp_option_data data; 2712 void *state, *ostate; 2713 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH]; 2714 2715 err = -EFAULT; 2716 if (copy_from_user(&data, (void __user *) arg, sizeof(data))) 2717 goto out; 2718 if (data.length > CCP_MAX_OPTION_LENGTH) 2719 goto out; 2720 if (copy_from_user(ccp_option, (void __user *) data.ptr, data.length)) 2721 goto out; 2722 2723 err = -EINVAL; 2724 if (data.length < 2 || ccp_option[1] < 2 || ccp_option[1] > data.length) 2725 goto out; 2726 2727 cp = try_then_request_module( 2728 find_compressor(ccp_option[0]), 2729 "ppp-compress-%d", ccp_option[0]); 2730 if (!cp) 2731 goto out; 2732 2733 err = -ENOBUFS; 2734 if (data.transmit) { 2735 state = cp->comp_alloc(ccp_option, data.length); 2736 if (state) { 2737 ppp_xmit_lock(ppp); 2738 ppp->xstate &= ~SC_COMP_RUN; 2739 ocomp = ppp->xcomp; 2740 ostate = ppp->xc_state; 2741 ppp->xcomp = cp; 2742 ppp->xc_state = state; 2743 ppp_xmit_unlock(ppp); 2744 if (ostate) { 2745 ocomp->comp_free(ostate); 2746 module_put(ocomp->owner); 2747 } 2748 err = 0; 2749 } else 2750 module_put(cp->owner); 2751 2752 } else { 2753 state = cp->decomp_alloc(ccp_option, data.length); 2754 if (state) { 2755 ppp_recv_lock(ppp); 2756 ppp->rstate &= ~SC_DECOMP_RUN; 2757 ocomp = ppp->rcomp; 2758 ostate = ppp->rc_state; 2759 ppp->rcomp = cp; 2760 ppp->rc_state = state; 2761 ppp_recv_unlock(ppp); 2762 if (ostate) { 2763 ocomp->decomp_free(ostate); 2764 module_put(ocomp->owner); 2765 } 2766 err = 0; 2767 } else 2768 module_put(cp->owner); 2769 } 2770 2771 out: 2772 return err; 2773 } 2774 2775 /* 2776 * Look at a CCP packet and update our state accordingly. 2777 * We assume the caller has the xmit or recv path locked. 2778 */ 2779 static void 2780 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound) 2781 { 2782 unsigned char *dp; 2783 int len; 2784 2785 if (!pskb_may_pull(skb, CCP_HDRLEN + 2)) 2786 return; /* no header */ 2787 dp = skb->data + 2; 2788 2789 switch (CCP_CODE(dp)) { 2790 case CCP_CONFREQ: 2791 2792 /* A ConfReq starts negotiation of compression 2793 * in one direction of transmission, 2794 * and hence brings it down...but which way? 2795 * 2796 * Remember: 2797 * A ConfReq indicates what the sender would like to receive 2798 */ 2799 if(inbound) 2800 /* He is proposing what I should send */ 2801 ppp->xstate &= ~SC_COMP_RUN; 2802 else 2803 /* I am proposing to what he should send */ 2804 ppp->rstate &= ~SC_DECOMP_RUN; 2805 2806 break; 2807 2808 case CCP_TERMREQ: 2809 case CCP_TERMACK: 2810 /* 2811 * CCP is going down, both directions of transmission 2812 */ 2813 ppp->rstate &= ~SC_DECOMP_RUN; 2814 ppp->xstate &= ~SC_COMP_RUN; 2815 break; 2816 2817 case CCP_CONFACK: 2818 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN) 2819 break; 2820 len = CCP_LENGTH(dp); 2821 if (!pskb_may_pull(skb, len + 2)) 2822 return; /* too short */ 2823 dp += CCP_HDRLEN; 2824 len -= CCP_HDRLEN; 2825 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp)) 2826 break; 2827 if (inbound) { 2828 /* we will start receiving compressed packets */ 2829 if (!ppp->rc_state) 2830 break; 2831 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len, 2832 ppp->file.index, 0, ppp->mru, ppp->debug)) { 2833 ppp->rstate |= SC_DECOMP_RUN; 2834 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR); 2835 } 2836 } else { 2837 /* we will soon start sending compressed packets */ 2838 if (!ppp->xc_state) 2839 break; 2840 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len, 2841 ppp->file.index, 0, ppp->debug)) 2842 ppp->xstate |= SC_COMP_RUN; 2843 } 2844 break; 2845 2846 case CCP_RESETACK: 2847 /* reset the [de]compressor */ 2848 if ((ppp->flags & SC_CCP_UP) == 0) 2849 break; 2850 if (inbound) { 2851 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) { 2852 ppp->rcomp->decomp_reset(ppp->rc_state); 2853 ppp->rstate &= ~SC_DC_ERROR; 2854 } 2855 } else { 2856 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN)) 2857 ppp->xcomp->comp_reset(ppp->xc_state); 2858 } 2859 break; 2860 } 2861 } 2862 2863 /* Free up compression resources. */ 2864 static void 2865 ppp_ccp_closed(struct ppp *ppp) 2866 { 2867 void *xstate, *rstate; 2868 struct compressor *xcomp, *rcomp; 2869 2870 ppp_lock(ppp); 2871 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP); 2872 ppp->xstate = 0; 2873 xcomp = ppp->xcomp; 2874 xstate = ppp->xc_state; 2875 ppp->xc_state = NULL; 2876 ppp->rstate = 0; 2877 rcomp = ppp->rcomp; 2878 rstate = ppp->rc_state; 2879 ppp->rc_state = NULL; 2880 ppp_unlock(ppp); 2881 2882 if (xstate) { 2883 xcomp->comp_free(xstate); 2884 module_put(xcomp->owner); 2885 } 2886 if (rstate) { 2887 rcomp->decomp_free(rstate); 2888 module_put(rcomp->owner); 2889 } 2890 } 2891 2892 /* List of compressors. */ 2893 static LIST_HEAD(compressor_list); 2894 static DEFINE_SPINLOCK(compressor_list_lock); 2895 2896 struct compressor_entry { 2897 struct list_head list; 2898 struct compressor *comp; 2899 }; 2900 2901 static struct compressor_entry * 2902 find_comp_entry(int proto) 2903 { 2904 struct compressor_entry *ce; 2905 2906 list_for_each_entry(ce, &compressor_list, list) { 2907 if (ce->comp->compress_proto == proto) 2908 return ce; 2909 } 2910 return NULL; 2911 } 2912 2913 /* Register a compressor */ 2914 int 2915 ppp_register_compressor(struct compressor *cp) 2916 { 2917 struct compressor_entry *ce; 2918 int ret; 2919 spin_lock(&compressor_list_lock); 2920 ret = -EEXIST; 2921 if (find_comp_entry(cp->compress_proto)) 2922 goto out; 2923 ret = -ENOMEM; 2924 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC); 2925 if (!ce) 2926 goto out; 2927 ret = 0; 2928 ce->comp = cp; 2929 list_add(&ce->list, &compressor_list); 2930 out: 2931 spin_unlock(&compressor_list_lock); 2932 return ret; 2933 } 2934 2935 /* Unregister a compressor */ 2936 void 2937 ppp_unregister_compressor(struct compressor *cp) 2938 { 2939 struct compressor_entry *ce; 2940 2941 spin_lock(&compressor_list_lock); 2942 ce = find_comp_entry(cp->compress_proto); 2943 if (ce && ce->comp == cp) { 2944 list_del(&ce->list); 2945 kfree(ce); 2946 } 2947 spin_unlock(&compressor_list_lock); 2948 } 2949 2950 /* Find a compressor. */ 2951 static struct compressor * 2952 find_compressor(int type) 2953 { 2954 struct compressor_entry *ce; 2955 struct compressor *cp = NULL; 2956 2957 spin_lock(&compressor_list_lock); 2958 ce = find_comp_entry(type); 2959 if (ce) { 2960 cp = ce->comp; 2961 if (!try_module_get(cp->owner)) 2962 cp = NULL; 2963 } 2964 spin_unlock(&compressor_list_lock); 2965 return cp; 2966 } 2967 2968 /* 2969 * Miscelleneous stuff. 2970 */ 2971 2972 static void 2973 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st) 2974 { 2975 struct slcompress *vj = ppp->vj; 2976 2977 memset(st, 0, sizeof(*st)); 2978 st->p.ppp_ipackets = ppp->stats64.rx_packets; 2979 st->p.ppp_ierrors = ppp->dev->stats.rx_errors; 2980 st->p.ppp_ibytes = ppp->stats64.rx_bytes; 2981 st->p.ppp_opackets = ppp->stats64.tx_packets; 2982 st->p.ppp_oerrors = ppp->dev->stats.tx_errors; 2983 st->p.ppp_obytes = ppp->stats64.tx_bytes; 2984 if (!vj) 2985 return; 2986 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed; 2987 st->vj.vjs_compressed = vj->sls_o_compressed; 2988 st->vj.vjs_searches = vj->sls_o_searches; 2989 st->vj.vjs_misses = vj->sls_o_misses; 2990 st->vj.vjs_errorin = vj->sls_i_error; 2991 st->vj.vjs_tossed = vj->sls_i_tossed; 2992 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed; 2993 st->vj.vjs_compressedin = vj->sls_i_compressed; 2994 } 2995 2996 /* 2997 * Stuff for handling the lists of ppp units and channels 2998 * and for initialization. 2999 */ 3000 3001 /* 3002 * Create a new ppp interface unit. Fails if it can't allocate memory 3003 * or if there is already a unit with the requested number. 3004 * unit == -1 means allocate a new number. 3005 */ 3006 static int ppp_create_interface(struct net *net, struct file *file, int *unit) 3007 { 3008 struct ppp_config conf = { 3009 .file = file, 3010 .unit = *unit, 3011 .ifname_is_set = false, 3012 }; 3013 struct net_device *dev; 3014 struct ppp *ppp; 3015 int err; 3016 3017 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup); 3018 if (!dev) { 3019 err = -ENOMEM; 3020 goto err; 3021 } 3022 dev_net_set(dev, net); 3023 dev->rtnl_link_ops = &ppp_link_ops; 3024 3025 rtnl_lock(); 3026 3027 err = ppp_dev_configure(net, dev, &conf); 3028 if (err < 0) 3029 goto err_dev; 3030 ppp = netdev_priv(dev); 3031 *unit = ppp->file.index; 3032 3033 rtnl_unlock(); 3034 3035 return 0; 3036 3037 err_dev: 3038 rtnl_unlock(); 3039 free_netdev(dev); 3040 err: 3041 return err; 3042 } 3043 3044 /* 3045 * Initialize a ppp_file structure. 3046 */ 3047 static void 3048 init_ppp_file(struct ppp_file *pf, int kind) 3049 { 3050 pf->kind = kind; 3051 skb_queue_head_init(&pf->xq); 3052 skb_queue_head_init(&pf->rq); 3053 refcount_set(&pf->refcnt, 1); 3054 init_waitqueue_head(&pf->rwait); 3055 } 3056 3057 /* 3058 * Free the memory used by a ppp unit. This is only called once 3059 * there are no channels connected to the unit and no file structs 3060 * that reference the unit. 3061 */ 3062 static void ppp_destroy_interface(struct ppp *ppp) 3063 { 3064 atomic_dec(&ppp_unit_count); 3065 3066 if (!ppp->file.dead || ppp->n_channels) { 3067 /* "can't happen" */ 3068 netdev_err(ppp->dev, "ppp: destroying ppp struct %p " 3069 "but dead=%d n_channels=%d !\n", 3070 ppp, ppp->file.dead, ppp->n_channels); 3071 return; 3072 } 3073 3074 ppp_ccp_closed(ppp); 3075 if (ppp->vj) { 3076 slhc_free(ppp->vj); 3077 ppp->vj = NULL; 3078 } 3079 skb_queue_purge(&ppp->file.xq); 3080 skb_queue_purge(&ppp->file.rq); 3081 #ifdef CONFIG_PPP_MULTILINK 3082 skb_queue_purge(&ppp->mrq); 3083 #endif /* CONFIG_PPP_MULTILINK */ 3084 #ifdef CONFIG_PPP_FILTER 3085 if (ppp->pass_filter) { 3086 bpf_prog_destroy(ppp->pass_filter); 3087 ppp->pass_filter = NULL; 3088 } 3089 3090 if (ppp->active_filter) { 3091 bpf_prog_destroy(ppp->active_filter); 3092 ppp->active_filter = NULL; 3093 } 3094 #endif /* CONFIG_PPP_FILTER */ 3095 3096 kfree_skb(ppp->xmit_pending); 3097 free_percpu(ppp->xmit_recursion); 3098 3099 free_netdev(ppp->dev); 3100 } 3101 3102 /* 3103 * Locate an existing ppp unit. 3104 * The caller should have locked the all_ppp_mutex. 3105 */ 3106 static struct ppp * 3107 ppp_find_unit(struct ppp_net *pn, int unit) 3108 { 3109 return unit_find(&pn->units_idr, unit); 3110 } 3111 3112 /* 3113 * Locate an existing ppp channel. 3114 * The caller should have locked the all_channels_lock. 3115 * First we look in the new_channels list, then in the 3116 * all_channels list. If found in the new_channels list, 3117 * we move it to the all_channels list. This is for speed 3118 * when we have a lot of channels in use. 3119 */ 3120 static struct channel * 3121 ppp_find_channel(struct ppp_net *pn, int unit) 3122 { 3123 struct channel *pch; 3124 3125 list_for_each_entry(pch, &pn->new_channels, list) { 3126 if (pch->file.index == unit) { 3127 list_move(&pch->list, &pn->all_channels); 3128 return pch; 3129 } 3130 } 3131 3132 list_for_each_entry(pch, &pn->all_channels, list) { 3133 if (pch->file.index == unit) 3134 return pch; 3135 } 3136 3137 return NULL; 3138 } 3139 3140 /* 3141 * Connect a PPP channel to a PPP interface unit. 3142 */ 3143 static int 3144 ppp_connect_channel(struct channel *pch, int unit) 3145 { 3146 struct ppp *ppp; 3147 struct ppp_net *pn; 3148 int ret = -ENXIO; 3149 int hdrlen; 3150 3151 pn = ppp_pernet(pch->chan_net); 3152 3153 mutex_lock(&pn->all_ppp_mutex); 3154 ppp = ppp_find_unit(pn, unit); 3155 if (!ppp) 3156 goto out; 3157 write_lock_bh(&pch->upl); 3158 ret = -EINVAL; 3159 if (pch->ppp) 3160 goto outl; 3161 3162 ppp_lock(ppp); 3163 if (pch->file.hdrlen > ppp->file.hdrlen) 3164 ppp->file.hdrlen = pch->file.hdrlen; 3165 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */ 3166 if (hdrlen > ppp->dev->hard_header_len) 3167 ppp->dev->hard_header_len = hdrlen; 3168 list_add_tail(&pch->clist, &ppp->channels); 3169 ++ppp->n_channels; 3170 pch->ppp = ppp; 3171 refcount_inc(&ppp->file.refcnt); 3172 ppp_unlock(ppp); 3173 ret = 0; 3174 3175 outl: 3176 write_unlock_bh(&pch->upl); 3177 out: 3178 mutex_unlock(&pn->all_ppp_mutex); 3179 return ret; 3180 } 3181 3182 /* 3183 * Disconnect a channel from its ppp unit. 3184 */ 3185 static int 3186 ppp_disconnect_channel(struct channel *pch) 3187 { 3188 struct ppp *ppp; 3189 int err = -EINVAL; 3190 3191 write_lock_bh(&pch->upl); 3192 ppp = pch->ppp; 3193 pch->ppp = NULL; 3194 write_unlock_bh(&pch->upl); 3195 if (ppp) { 3196 /* remove it from the ppp unit's list */ 3197 ppp_lock(ppp); 3198 list_del(&pch->clist); 3199 if (--ppp->n_channels == 0) 3200 wake_up_interruptible(&ppp->file.rwait); 3201 ppp_unlock(ppp); 3202 if (refcount_dec_and_test(&ppp->file.refcnt)) 3203 ppp_destroy_interface(ppp); 3204 err = 0; 3205 } 3206 return err; 3207 } 3208 3209 /* 3210 * Free up the resources used by a ppp channel. 3211 */ 3212 static void ppp_destroy_channel(struct channel *pch) 3213 { 3214 put_net(pch->chan_net); 3215 pch->chan_net = NULL; 3216 3217 atomic_dec(&channel_count); 3218 3219 if (!pch->file.dead) { 3220 /* "can't happen" */ 3221 pr_err("ppp: destroying undead channel %p !\n", pch); 3222 return; 3223 } 3224 skb_queue_purge(&pch->file.xq); 3225 skb_queue_purge(&pch->file.rq); 3226 kfree(pch); 3227 } 3228 3229 static void __exit ppp_cleanup(void) 3230 { 3231 /* should never happen */ 3232 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count)) 3233 pr_err("PPP: removing module but units remain!\n"); 3234 rtnl_link_unregister(&ppp_link_ops); 3235 unregister_chrdev(PPP_MAJOR, "ppp"); 3236 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0)); 3237 class_destroy(ppp_class); 3238 unregister_pernet_device(&ppp_net_ops); 3239 } 3240 3241 /* 3242 * Units handling. Caller must protect concurrent access 3243 * by holding all_ppp_mutex 3244 */ 3245 3246 /* associate pointer with specified number */ 3247 static int unit_set(struct idr *p, void *ptr, int n) 3248 { 3249 int unit; 3250 3251 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL); 3252 if (unit == -ENOSPC) 3253 unit = -EINVAL; 3254 return unit; 3255 } 3256 3257 /* get new free unit number and associate pointer with it */ 3258 static int unit_get(struct idr *p, void *ptr) 3259 { 3260 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL); 3261 } 3262 3263 /* put unit number back to a pool */ 3264 static void unit_put(struct idr *p, int n) 3265 { 3266 idr_remove(p, n); 3267 } 3268 3269 /* get pointer associated with the number */ 3270 static void *unit_find(struct idr *p, int n) 3271 { 3272 return idr_find(p, n); 3273 } 3274 3275 /* Module/initialization stuff */ 3276 3277 module_init(ppp_init); 3278 module_exit(ppp_cleanup); 3279 3280 EXPORT_SYMBOL(ppp_register_net_channel); 3281 EXPORT_SYMBOL(ppp_register_channel); 3282 EXPORT_SYMBOL(ppp_unregister_channel); 3283 EXPORT_SYMBOL(ppp_channel_index); 3284 EXPORT_SYMBOL(ppp_unit_number); 3285 EXPORT_SYMBOL(ppp_dev_name); 3286 EXPORT_SYMBOL(ppp_input); 3287 EXPORT_SYMBOL(ppp_input_error); 3288 EXPORT_SYMBOL(ppp_output_wakeup); 3289 EXPORT_SYMBOL(ppp_register_compressor); 3290 EXPORT_SYMBOL(ppp_unregister_compressor); 3291 MODULE_LICENSE("GPL"); 3292 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0); 3293 MODULE_ALIAS_RTNL_LINK("ppp"); 3294 MODULE_ALIAS("devname:ppp"); 3295