1 /* 2 * Generic PPP layer for Linux. 3 * 4 * Copyright 1999-2002 Paul Mackerras. 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 * 11 * The generic PPP layer handles the PPP network interfaces, the 12 * /dev/ppp device, packet and VJ compression, and multilink. 13 * It talks to PPP `channels' via the interface defined in 14 * include/linux/ppp_channel.h. Channels provide the basic means for 15 * sending and receiving PPP frames on some kind of communications 16 * channel. 17 * 18 * Part of the code in this driver was inspired by the old async-only 19 * PPP driver, written by Michael Callahan and Al Longyear, and 20 * subsequently hacked by Paul Mackerras. 21 * 22 * ==FILEVERSION 20041108== 23 */ 24 25 #include <linux/module.h> 26 #include <linux/kernel.h> 27 #include <linux/kmod.h> 28 #include <linux/init.h> 29 #include <linux/list.h> 30 #include <linux/idr.h> 31 #include <linux/netdevice.h> 32 #include <linux/poll.h> 33 #include <linux/ppp_defs.h> 34 #include <linux/filter.h> 35 #include <linux/ppp-ioctl.h> 36 #include <linux/ppp_channel.h> 37 #include <linux/ppp-comp.h> 38 #include <linux/skbuff.h> 39 #include <linux/rtnetlink.h> 40 #include <linux/if_arp.h> 41 #include <linux/ip.h> 42 #include <linux/tcp.h> 43 #include <linux/spinlock.h> 44 #include <linux/rwsem.h> 45 #include <linux/stddef.h> 46 #include <linux/device.h> 47 #include <linux/mutex.h> 48 #include <linux/slab.h> 49 #include <asm/unaligned.h> 50 #include <net/slhc_vj.h> 51 #include <linux/atomic.h> 52 53 #include <linux/nsproxy.h> 54 #include <net/net_namespace.h> 55 #include <net/netns/generic.h> 56 57 #define PPP_VERSION "2.4.2" 58 59 /* 60 * Network protocols we support. 61 */ 62 #define NP_IP 0 /* Internet Protocol V4 */ 63 #define NP_IPV6 1 /* Internet Protocol V6 */ 64 #define NP_IPX 2 /* IPX protocol */ 65 #define NP_AT 3 /* Appletalk protocol */ 66 #define NP_MPLS_UC 4 /* MPLS unicast */ 67 #define NP_MPLS_MC 5 /* MPLS multicast */ 68 #define NUM_NP 6 /* Number of NPs. */ 69 70 #define MPHDRLEN 6 /* multilink protocol header length */ 71 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */ 72 73 /* 74 * An instance of /dev/ppp can be associated with either a ppp 75 * interface unit or a ppp channel. In both cases, file->private_data 76 * points to one of these. 77 */ 78 struct ppp_file { 79 enum { 80 INTERFACE=1, CHANNEL 81 } kind; 82 struct sk_buff_head xq; /* pppd transmit queue */ 83 struct sk_buff_head rq; /* receive queue for pppd */ 84 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */ 85 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */ 86 int hdrlen; /* space to leave for headers */ 87 int index; /* interface unit / channel number */ 88 int dead; /* unit/channel has been shut down */ 89 }; 90 91 #define PF_TO_X(pf, X) container_of(pf, X, file) 92 93 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp) 94 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel) 95 96 /* 97 * Data structure to hold primary network stats for which 98 * we want to use 64 bit storage. Other network stats 99 * are stored in dev->stats of the ppp strucute. 100 */ 101 struct ppp_link_stats { 102 u64 rx_packets; 103 u64 tx_packets; 104 u64 rx_bytes; 105 u64 tx_bytes; 106 }; 107 108 /* 109 * Data structure describing one ppp unit. 110 * A ppp unit corresponds to a ppp network interface device 111 * and represents a multilink bundle. 112 * It can have 0 or more ppp channels connected to it. 113 */ 114 struct ppp { 115 struct ppp_file file; /* stuff for read/write/poll 0 */ 116 struct file *owner; /* file that owns this unit 48 */ 117 struct list_head channels; /* list of attached channels 4c */ 118 int n_channels; /* how many channels are attached 54 */ 119 spinlock_t rlock; /* lock for receive side 58 */ 120 spinlock_t wlock; /* lock for transmit side 5c */ 121 int mru; /* max receive unit 60 */ 122 unsigned int flags; /* control bits 64 */ 123 unsigned int xstate; /* transmit state bits 68 */ 124 unsigned int rstate; /* receive state bits 6c */ 125 int debug; /* debug flags 70 */ 126 struct slcompress *vj; /* state for VJ header compression */ 127 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */ 128 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */ 129 struct compressor *xcomp; /* transmit packet compressor 8c */ 130 void *xc_state; /* its internal state 90 */ 131 struct compressor *rcomp; /* receive decompressor 94 */ 132 void *rc_state; /* its internal state 98 */ 133 unsigned long last_xmit; /* jiffies when last pkt sent 9c */ 134 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */ 135 struct net_device *dev; /* network interface device a4 */ 136 int closing; /* is device closing down? a8 */ 137 #ifdef CONFIG_PPP_MULTILINK 138 int nxchan; /* next channel to send something on */ 139 u32 nxseq; /* next sequence number to send */ 140 int mrru; /* MP: max reconst. receive unit */ 141 u32 nextseq; /* MP: seq no of next packet */ 142 u32 minseq; /* MP: min of most recent seqnos */ 143 struct sk_buff_head mrq; /* MP: receive reconstruction queue */ 144 #endif /* CONFIG_PPP_MULTILINK */ 145 #ifdef CONFIG_PPP_FILTER 146 struct bpf_prog *pass_filter; /* filter for packets to pass */ 147 struct bpf_prog *active_filter; /* filter for pkts to reset idle */ 148 #endif /* CONFIG_PPP_FILTER */ 149 struct net *ppp_net; /* the net we belong to */ 150 struct ppp_link_stats stats64; /* 64 bit network stats */ 151 }; 152 153 /* 154 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC, 155 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP, 156 * SC_MUST_COMP 157 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR. 158 * Bits in xstate: SC_COMP_RUN 159 */ 160 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \ 161 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \ 162 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP) 163 164 /* 165 * Private data structure for each channel. 166 * This includes the data structure used for multilink. 167 */ 168 struct channel { 169 struct ppp_file file; /* stuff for read/write/poll */ 170 struct list_head list; /* link in all/new_channels list */ 171 struct ppp_channel *chan; /* public channel data structure */ 172 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */ 173 spinlock_t downl; /* protects `chan', file.xq dequeue */ 174 struct ppp *ppp; /* ppp unit we're connected to */ 175 struct net *chan_net; /* the net channel belongs to */ 176 struct list_head clist; /* link in list of channels per unit */ 177 rwlock_t upl; /* protects `ppp' */ 178 #ifdef CONFIG_PPP_MULTILINK 179 u8 avail; /* flag used in multilink stuff */ 180 u8 had_frag; /* >= 1 fragments have been sent */ 181 u32 lastseq; /* MP: last sequence # received */ 182 int speed; /* speed of the corresponding ppp channel*/ 183 #endif /* CONFIG_PPP_MULTILINK */ 184 }; 185 186 /* 187 * SMP locking issues: 188 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels 189 * list and the ppp.n_channels field, you need to take both locks 190 * before you modify them. 191 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock -> 192 * channel.downl. 193 */ 194 195 static DEFINE_MUTEX(ppp_mutex); 196 static atomic_t ppp_unit_count = ATOMIC_INIT(0); 197 static atomic_t channel_count = ATOMIC_INIT(0); 198 199 /* per-net private data for this module */ 200 static int ppp_net_id __read_mostly; 201 struct ppp_net { 202 /* units to ppp mapping */ 203 struct idr units_idr; 204 205 /* 206 * all_ppp_mutex protects the units_idr mapping. 207 * It also ensures that finding a ppp unit in the units_idr 208 * map and updating its file.refcnt field is atomic. 209 */ 210 struct mutex all_ppp_mutex; 211 212 /* channels */ 213 struct list_head all_channels; 214 struct list_head new_channels; 215 int last_channel_index; 216 217 /* 218 * all_channels_lock protects all_channels and 219 * last_channel_index, and the atomicity of find 220 * a channel and updating its file.refcnt field. 221 */ 222 spinlock_t all_channels_lock; 223 }; 224 225 /* Get the PPP protocol number from a skb */ 226 #define PPP_PROTO(skb) get_unaligned_be16((skb)->data) 227 228 /* We limit the length of ppp->file.rq to this (arbitrary) value */ 229 #define PPP_MAX_RQLEN 32 230 231 /* 232 * Maximum number of multilink fragments queued up. 233 * This has to be large enough to cope with the maximum latency of 234 * the slowest channel relative to the others. Strictly it should 235 * depend on the number of channels and their characteristics. 236 */ 237 #define PPP_MP_MAX_QLEN 128 238 239 /* Multilink header bits. */ 240 #define B 0x80 /* this fragment begins a packet */ 241 #define E 0x40 /* this fragment ends a packet */ 242 243 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */ 244 #define seq_before(a, b) ((s32)((a) - (b)) < 0) 245 #define seq_after(a, b) ((s32)((a) - (b)) > 0) 246 247 /* Prototypes. */ 248 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 249 struct file *file, unsigned int cmd, unsigned long arg); 250 static void ppp_xmit_process(struct ppp *ppp); 251 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb); 252 static void ppp_push(struct ppp *ppp); 253 static void ppp_channel_push(struct channel *pch); 254 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, 255 struct channel *pch); 256 static void ppp_receive_error(struct ppp *ppp); 257 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb); 258 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp, 259 struct sk_buff *skb); 260 #ifdef CONFIG_PPP_MULTILINK 261 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, 262 struct channel *pch); 263 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb); 264 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp); 265 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb); 266 #endif /* CONFIG_PPP_MULTILINK */ 267 static int ppp_set_compress(struct ppp *ppp, unsigned long arg); 268 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound); 269 static void ppp_ccp_closed(struct ppp *ppp); 270 static struct compressor *find_compressor(int type); 271 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st); 272 static struct ppp *ppp_create_interface(struct net *net, int unit, 273 struct file *file, int *retp); 274 static void init_ppp_file(struct ppp_file *pf, int kind); 275 static void ppp_destroy_interface(struct ppp *ppp); 276 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit); 277 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit); 278 static int ppp_connect_channel(struct channel *pch, int unit); 279 static int ppp_disconnect_channel(struct channel *pch); 280 static void ppp_destroy_channel(struct channel *pch); 281 static int unit_get(struct idr *p, void *ptr); 282 static int unit_set(struct idr *p, void *ptr, int n); 283 static void unit_put(struct idr *p, int n); 284 static void *unit_find(struct idr *p, int n); 285 286 static const struct net_device_ops ppp_netdev_ops; 287 288 static struct class *ppp_class; 289 290 /* per net-namespace data */ 291 static inline struct ppp_net *ppp_pernet(struct net *net) 292 { 293 BUG_ON(!net); 294 295 return net_generic(net, ppp_net_id); 296 } 297 298 /* Translates a PPP protocol number to a NP index (NP == network protocol) */ 299 static inline int proto_to_npindex(int proto) 300 { 301 switch (proto) { 302 case PPP_IP: 303 return NP_IP; 304 case PPP_IPV6: 305 return NP_IPV6; 306 case PPP_IPX: 307 return NP_IPX; 308 case PPP_AT: 309 return NP_AT; 310 case PPP_MPLS_UC: 311 return NP_MPLS_UC; 312 case PPP_MPLS_MC: 313 return NP_MPLS_MC; 314 } 315 return -EINVAL; 316 } 317 318 /* Translates an NP index into a PPP protocol number */ 319 static const int npindex_to_proto[NUM_NP] = { 320 PPP_IP, 321 PPP_IPV6, 322 PPP_IPX, 323 PPP_AT, 324 PPP_MPLS_UC, 325 PPP_MPLS_MC, 326 }; 327 328 /* Translates an ethertype into an NP index */ 329 static inline int ethertype_to_npindex(int ethertype) 330 { 331 switch (ethertype) { 332 case ETH_P_IP: 333 return NP_IP; 334 case ETH_P_IPV6: 335 return NP_IPV6; 336 case ETH_P_IPX: 337 return NP_IPX; 338 case ETH_P_PPPTALK: 339 case ETH_P_ATALK: 340 return NP_AT; 341 case ETH_P_MPLS_UC: 342 return NP_MPLS_UC; 343 case ETH_P_MPLS_MC: 344 return NP_MPLS_MC; 345 } 346 return -1; 347 } 348 349 /* Translates an NP index into an ethertype */ 350 static const int npindex_to_ethertype[NUM_NP] = { 351 ETH_P_IP, 352 ETH_P_IPV6, 353 ETH_P_IPX, 354 ETH_P_PPPTALK, 355 ETH_P_MPLS_UC, 356 ETH_P_MPLS_MC, 357 }; 358 359 /* 360 * Locking shorthand. 361 */ 362 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock) 363 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock) 364 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock) 365 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock) 366 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \ 367 ppp_recv_lock(ppp); } while (0) 368 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \ 369 ppp_xmit_unlock(ppp); } while (0) 370 371 /* 372 * /dev/ppp device routines. 373 * The /dev/ppp device is used by pppd to control the ppp unit. 374 * It supports the read, write, ioctl and poll functions. 375 * Open instances of /dev/ppp can be in one of three states: 376 * unattached, attached to a ppp unit, or attached to a ppp channel. 377 */ 378 static int ppp_open(struct inode *inode, struct file *file) 379 { 380 /* 381 * This could (should?) be enforced by the permissions on /dev/ppp. 382 */ 383 if (!capable(CAP_NET_ADMIN)) 384 return -EPERM; 385 return 0; 386 } 387 388 static int ppp_release(struct inode *unused, struct file *file) 389 { 390 struct ppp_file *pf = file->private_data; 391 struct ppp *ppp; 392 393 if (pf) { 394 file->private_data = NULL; 395 if (pf->kind == INTERFACE) { 396 ppp = PF_TO_PPP(pf); 397 rtnl_lock(); 398 if (file == ppp->owner) 399 unregister_netdevice(ppp->dev); 400 rtnl_unlock(); 401 } 402 if (atomic_dec_and_test(&pf->refcnt)) { 403 switch (pf->kind) { 404 case INTERFACE: 405 ppp_destroy_interface(PF_TO_PPP(pf)); 406 break; 407 case CHANNEL: 408 ppp_destroy_channel(PF_TO_CHANNEL(pf)); 409 break; 410 } 411 } 412 } 413 return 0; 414 } 415 416 static ssize_t ppp_read(struct file *file, char __user *buf, 417 size_t count, loff_t *ppos) 418 { 419 struct ppp_file *pf = file->private_data; 420 DECLARE_WAITQUEUE(wait, current); 421 ssize_t ret; 422 struct sk_buff *skb = NULL; 423 struct iovec iov; 424 struct iov_iter to; 425 426 ret = count; 427 428 if (!pf) 429 return -ENXIO; 430 add_wait_queue(&pf->rwait, &wait); 431 for (;;) { 432 set_current_state(TASK_INTERRUPTIBLE); 433 skb = skb_dequeue(&pf->rq); 434 if (skb) 435 break; 436 ret = 0; 437 if (pf->dead) 438 break; 439 if (pf->kind == INTERFACE) { 440 /* 441 * Return 0 (EOF) on an interface that has no 442 * channels connected, unless it is looping 443 * network traffic (demand mode). 444 */ 445 struct ppp *ppp = PF_TO_PPP(pf); 446 if (ppp->n_channels == 0 && 447 (ppp->flags & SC_LOOP_TRAFFIC) == 0) 448 break; 449 } 450 ret = -EAGAIN; 451 if (file->f_flags & O_NONBLOCK) 452 break; 453 ret = -ERESTARTSYS; 454 if (signal_pending(current)) 455 break; 456 schedule(); 457 } 458 set_current_state(TASK_RUNNING); 459 remove_wait_queue(&pf->rwait, &wait); 460 461 if (!skb) 462 goto out; 463 464 ret = -EOVERFLOW; 465 if (skb->len > count) 466 goto outf; 467 ret = -EFAULT; 468 iov.iov_base = buf; 469 iov.iov_len = count; 470 iov_iter_init(&to, READ, &iov, 1, count); 471 if (skb_copy_datagram_iter(skb, 0, &to, skb->len)) 472 goto outf; 473 ret = skb->len; 474 475 outf: 476 kfree_skb(skb); 477 out: 478 return ret; 479 } 480 481 static ssize_t ppp_write(struct file *file, const char __user *buf, 482 size_t count, loff_t *ppos) 483 { 484 struct ppp_file *pf = file->private_data; 485 struct sk_buff *skb; 486 ssize_t ret; 487 488 if (!pf) 489 return -ENXIO; 490 ret = -ENOMEM; 491 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL); 492 if (!skb) 493 goto out; 494 skb_reserve(skb, pf->hdrlen); 495 ret = -EFAULT; 496 if (copy_from_user(skb_put(skb, count), buf, count)) { 497 kfree_skb(skb); 498 goto out; 499 } 500 501 skb_queue_tail(&pf->xq, skb); 502 503 switch (pf->kind) { 504 case INTERFACE: 505 ppp_xmit_process(PF_TO_PPP(pf)); 506 break; 507 case CHANNEL: 508 ppp_channel_push(PF_TO_CHANNEL(pf)); 509 break; 510 } 511 512 ret = count; 513 514 out: 515 return ret; 516 } 517 518 /* No kernel lock - fine */ 519 static unsigned int ppp_poll(struct file *file, poll_table *wait) 520 { 521 struct ppp_file *pf = file->private_data; 522 unsigned int mask; 523 524 if (!pf) 525 return 0; 526 poll_wait(file, &pf->rwait, wait); 527 mask = POLLOUT | POLLWRNORM; 528 if (skb_peek(&pf->rq)) 529 mask |= POLLIN | POLLRDNORM; 530 if (pf->dead) 531 mask |= POLLHUP; 532 else if (pf->kind == INTERFACE) { 533 /* see comment in ppp_read */ 534 struct ppp *ppp = PF_TO_PPP(pf); 535 if (ppp->n_channels == 0 && 536 (ppp->flags & SC_LOOP_TRAFFIC) == 0) 537 mask |= POLLIN | POLLRDNORM; 538 } 539 540 return mask; 541 } 542 543 #ifdef CONFIG_PPP_FILTER 544 static int get_filter(void __user *arg, struct sock_filter **p) 545 { 546 struct sock_fprog uprog; 547 struct sock_filter *code = NULL; 548 int len; 549 550 if (copy_from_user(&uprog, arg, sizeof(uprog))) 551 return -EFAULT; 552 553 if (!uprog.len) { 554 *p = NULL; 555 return 0; 556 } 557 558 len = uprog.len * sizeof(struct sock_filter); 559 code = memdup_user(uprog.filter, len); 560 if (IS_ERR(code)) 561 return PTR_ERR(code); 562 563 *p = code; 564 return uprog.len; 565 } 566 #endif /* CONFIG_PPP_FILTER */ 567 568 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 569 { 570 struct ppp_file *pf = file->private_data; 571 struct ppp *ppp; 572 int err = -EFAULT, val, val2, i; 573 struct ppp_idle idle; 574 struct npioctl npi; 575 int unit, cflags; 576 struct slcompress *vj; 577 void __user *argp = (void __user *)arg; 578 int __user *p = argp; 579 580 if (!pf) 581 return ppp_unattached_ioctl(current->nsproxy->net_ns, 582 pf, file, cmd, arg); 583 584 if (cmd == PPPIOCDETACH) { 585 /* 586 * We have to be careful here... if the file descriptor 587 * has been dup'd, we could have another process in the 588 * middle of a poll using the same file *, so we had 589 * better not free the interface data structures - 590 * instead we fail the ioctl. Even in this case, we 591 * shut down the interface if we are the owner of it. 592 * Actually, we should get rid of PPPIOCDETACH, userland 593 * (i.e. pppd) could achieve the same effect by closing 594 * this fd and reopening /dev/ppp. 595 */ 596 err = -EINVAL; 597 mutex_lock(&ppp_mutex); 598 if (pf->kind == INTERFACE) { 599 ppp = PF_TO_PPP(pf); 600 rtnl_lock(); 601 if (file == ppp->owner) 602 unregister_netdevice(ppp->dev); 603 rtnl_unlock(); 604 } 605 if (atomic_long_read(&file->f_count) < 2) { 606 ppp_release(NULL, file); 607 err = 0; 608 } else 609 pr_warn("PPPIOCDETACH file->f_count=%ld\n", 610 atomic_long_read(&file->f_count)); 611 mutex_unlock(&ppp_mutex); 612 return err; 613 } 614 615 if (pf->kind == CHANNEL) { 616 struct channel *pch; 617 struct ppp_channel *chan; 618 619 mutex_lock(&ppp_mutex); 620 pch = PF_TO_CHANNEL(pf); 621 622 switch (cmd) { 623 case PPPIOCCONNECT: 624 if (get_user(unit, p)) 625 break; 626 err = ppp_connect_channel(pch, unit); 627 break; 628 629 case PPPIOCDISCONN: 630 err = ppp_disconnect_channel(pch); 631 break; 632 633 default: 634 down_read(&pch->chan_sem); 635 chan = pch->chan; 636 err = -ENOTTY; 637 if (chan && chan->ops->ioctl) 638 err = chan->ops->ioctl(chan, cmd, arg); 639 up_read(&pch->chan_sem); 640 } 641 mutex_unlock(&ppp_mutex); 642 return err; 643 } 644 645 if (pf->kind != INTERFACE) { 646 /* can't happen */ 647 pr_err("PPP: not interface or channel??\n"); 648 return -EINVAL; 649 } 650 651 mutex_lock(&ppp_mutex); 652 ppp = PF_TO_PPP(pf); 653 switch (cmd) { 654 case PPPIOCSMRU: 655 if (get_user(val, p)) 656 break; 657 ppp->mru = val; 658 err = 0; 659 break; 660 661 case PPPIOCSFLAGS: 662 if (get_user(val, p)) 663 break; 664 ppp_lock(ppp); 665 cflags = ppp->flags & ~val; 666 #ifdef CONFIG_PPP_MULTILINK 667 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK)) 668 ppp->nextseq = 0; 669 #endif 670 ppp->flags = val & SC_FLAG_BITS; 671 ppp_unlock(ppp); 672 if (cflags & SC_CCP_OPEN) 673 ppp_ccp_closed(ppp); 674 err = 0; 675 break; 676 677 case PPPIOCGFLAGS: 678 val = ppp->flags | ppp->xstate | ppp->rstate; 679 if (put_user(val, p)) 680 break; 681 err = 0; 682 break; 683 684 case PPPIOCSCOMPRESS: 685 err = ppp_set_compress(ppp, arg); 686 break; 687 688 case PPPIOCGUNIT: 689 if (put_user(ppp->file.index, p)) 690 break; 691 err = 0; 692 break; 693 694 case PPPIOCSDEBUG: 695 if (get_user(val, p)) 696 break; 697 ppp->debug = val; 698 err = 0; 699 break; 700 701 case PPPIOCGDEBUG: 702 if (put_user(ppp->debug, p)) 703 break; 704 err = 0; 705 break; 706 707 case PPPIOCGIDLE: 708 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ; 709 idle.recv_idle = (jiffies - ppp->last_recv) / HZ; 710 if (copy_to_user(argp, &idle, sizeof(idle))) 711 break; 712 err = 0; 713 break; 714 715 case PPPIOCSMAXCID: 716 if (get_user(val, p)) 717 break; 718 val2 = 15; 719 if ((val >> 16) != 0) { 720 val2 = val >> 16; 721 val &= 0xffff; 722 } 723 vj = slhc_init(val2+1, val+1); 724 if (IS_ERR(vj)) { 725 err = PTR_ERR(vj); 726 break; 727 } 728 ppp_lock(ppp); 729 if (ppp->vj) 730 slhc_free(ppp->vj); 731 ppp->vj = vj; 732 ppp_unlock(ppp); 733 err = 0; 734 break; 735 736 case PPPIOCGNPMODE: 737 case PPPIOCSNPMODE: 738 if (copy_from_user(&npi, argp, sizeof(npi))) 739 break; 740 err = proto_to_npindex(npi.protocol); 741 if (err < 0) 742 break; 743 i = err; 744 if (cmd == PPPIOCGNPMODE) { 745 err = -EFAULT; 746 npi.mode = ppp->npmode[i]; 747 if (copy_to_user(argp, &npi, sizeof(npi))) 748 break; 749 } else { 750 ppp->npmode[i] = npi.mode; 751 /* we may be able to transmit more packets now (??) */ 752 netif_wake_queue(ppp->dev); 753 } 754 err = 0; 755 break; 756 757 #ifdef CONFIG_PPP_FILTER 758 case PPPIOCSPASS: 759 { 760 struct sock_filter *code; 761 762 err = get_filter(argp, &code); 763 if (err >= 0) { 764 struct bpf_prog *pass_filter = NULL; 765 struct sock_fprog_kern fprog = { 766 .len = err, 767 .filter = code, 768 }; 769 770 err = 0; 771 if (fprog.filter) 772 err = bpf_prog_create(&pass_filter, &fprog); 773 if (!err) { 774 ppp_lock(ppp); 775 if (ppp->pass_filter) 776 bpf_prog_destroy(ppp->pass_filter); 777 ppp->pass_filter = pass_filter; 778 ppp_unlock(ppp); 779 } 780 kfree(code); 781 } 782 break; 783 } 784 case PPPIOCSACTIVE: 785 { 786 struct sock_filter *code; 787 788 err = get_filter(argp, &code); 789 if (err >= 0) { 790 struct bpf_prog *active_filter = NULL; 791 struct sock_fprog_kern fprog = { 792 .len = err, 793 .filter = code, 794 }; 795 796 err = 0; 797 if (fprog.filter) 798 err = bpf_prog_create(&active_filter, &fprog); 799 if (!err) { 800 ppp_lock(ppp); 801 if (ppp->active_filter) 802 bpf_prog_destroy(ppp->active_filter); 803 ppp->active_filter = active_filter; 804 ppp_unlock(ppp); 805 } 806 kfree(code); 807 } 808 break; 809 } 810 #endif /* CONFIG_PPP_FILTER */ 811 812 #ifdef CONFIG_PPP_MULTILINK 813 case PPPIOCSMRRU: 814 if (get_user(val, p)) 815 break; 816 ppp_recv_lock(ppp); 817 ppp->mrru = val; 818 ppp_recv_unlock(ppp); 819 err = 0; 820 break; 821 #endif /* CONFIG_PPP_MULTILINK */ 822 823 default: 824 err = -ENOTTY; 825 } 826 mutex_unlock(&ppp_mutex); 827 return err; 828 } 829 830 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 831 struct file *file, unsigned int cmd, unsigned long arg) 832 { 833 int unit, err = -EFAULT; 834 struct ppp *ppp; 835 struct channel *chan; 836 struct ppp_net *pn; 837 int __user *p = (int __user *)arg; 838 839 mutex_lock(&ppp_mutex); 840 switch (cmd) { 841 case PPPIOCNEWUNIT: 842 /* Create a new ppp unit */ 843 if (get_user(unit, p)) 844 break; 845 ppp = ppp_create_interface(net, unit, file, &err); 846 if (!ppp) 847 break; 848 file->private_data = &ppp->file; 849 err = -EFAULT; 850 if (put_user(ppp->file.index, p)) 851 break; 852 err = 0; 853 break; 854 855 case PPPIOCATTACH: 856 /* Attach to an existing ppp unit */ 857 if (get_user(unit, p)) 858 break; 859 err = -ENXIO; 860 pn = ppp_pernet(net); 861 mutex_lock(&pn->all_ppp_mutex); 862 ppp = ppp_find_unit(pn, unit); 863 if (ppp) { 864 atomic_inc(&ppp->file.refcnt); 865 file->private_data = &ppp->file; 866 err = 0; 867 } 868 mutex_unlock(&pn->all_ppp_mutex); 869 break; 870 871 case PPPIOCATTCHAN: 872 if (get_user(unit, p)) 873 break; 874 err = -ENXIO; 875 pn = ppp_pernet(net); 876 spin_lock_bh(&pn->all_channels_lock); 877 chan = ppp_find_channel(pn, unit); 878 if (chan) { 879 atomic_inc(&chan->file.refcnt); 880 file->private_data = &chan->file; 881 err = 0; 882 } 883 spin_unlock_bh(&pn->all_channels_lock); 884 break; 885 886 default: 887 err = -ENOTTY; 888 } 889 mutex_unlock(&ppp_mutex); 890 return err; 891 } 892 893 static const struct file_operations ppp_device_fops = { 894 .owner = THIS_MODULE, 895 .read = ppp_read, 896 .write = ppp_write, 897 .poll = ppp_poll, 898 .unlocked_ioctl = ppp_ioctl, 899 .open = ppp_open, 900 .release = ppp_release, 901 .llseek = noop_llseek, 902 }; 903 904 static __net_init int ppp_init_net(struct net *net) 905 { 906 struct ppp_net *pn = net_generic(net, ppp_net_id); 907 908 idr_init(&pn->units_idr); 909 mutex_init(&pn->all_ppp_mutex); 910 911 INIT_LIST_HEAD(&pn->all_channels); 912 INIT_LIST_HEAD(&pn->new_channels); 913 914 spin_lock_init(&pn->all_channels_lock); 915 916 return 0; 917 } 918 919 static __net_exit void ppp_exit_net(struct net *net) 920 { 921 struct ppp_net *pn = net_generic(net, ppp_net_id); 922 struct net_device *dev; 923 struct net_device *aux; 924 struct ppp *ppp; 925 LIST_HEAD(list); 926 int id; 927 928 rtnl_lock(); 929 for_each_netdev_safe(net, dev, aux) { 930 if (dev->netdev_ops == &ppp_netdev_ops) 931 unregister_netdevice_queue(dev, &list); 932 } 933 934 idr_for_each_entry(&pn->units_idr, ppp, id) 935 /* Skip devices already unregistered by previous loop */ 936 if (!net_eq(dev_net(ppp->dev), net)) 937 unregister_netdevice_queue(ppp->dev, &list); 938 939 unregister_netdevice_many(&list); 940 rtnl_unlock(); 941 942 idr_destroy(&pn->units_idr); 943 } 944 945 static struct pernet_operations ppp_net_ops = { 946 .init = ppp_init_net, 947 .exit = ppp_exit_net, 948 .id = &ppp_net_id, 949 .size = sizeof(struct ppp_net), 950 }; 951 952 #define PPP_MAJOR 108 953 954 /* Called at boot time if ppp is compiled into the kernel, 955 or at module load time (from init_module) if compiled as a module. */ 956 static int __init ppp_init(void) 957 { 958 int err; 959 960 pr_info("PPP generic driver version " PPP_VERSION "\n"); 961 962 err = register_pernet_device(&ppp_net_ops); 963 if (err) { 964 pr_err("failed to register PPP pernet device (%d)\n", err); 965 goto out; 966 } 967 968 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops); 969 if (err) { 970 pr_err("failed to register PPP device (%d)\n", err); 971 goto out_net; 972 } 973 974 ppp_class = class_create(THIS_MODULE, "ppp"); 975 if (IS_ERR(ppp_class)) { 976 err = PTR_ERR(ppp_class); 977 goto out_chrdev; 978 } 979 980 /* not a big deal if we fail here :-) */ 981 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp"); 982 983 return 0; 984 985 out_chrdev: 986 unregister_chrdev(PPP_MAJOR, "ppp"); 987 out_net: 988 unregister_pernet_device(&ppp_net_ops); 989 out: 990 return err; 991 } 992 993 /* 994 * Network interface unit routines. 995 */ 996 static netdev_tx_t 997 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev) 998 { 999 struct ppp *ppp = netdev_priv(dev); 1000 int npi, proto; 1001 unsigned char *pp; 1002 1003 npi = ethertype_to_npindex(ntohs(skb->protocol)); 1004 if (npi < 0) 1005 goto outf; 1006 1007 /* Drop, accept or reject the packet */ 1008 switch (ppp->npmode[npi]) { 1009 case NPMODE_PASS: 1010 break; 1011 case NPMODE_QUEUE: 1012 /* it would be nice to have a way to tell the network 1013 system to queue this one up for later. */ 1014 goto outf; 1015 case NPMODE_DROP: 1016 case NPMODE_ERROR: 1017 goto outf; 1018 } 1019 1020 /* Put the 2-byte PPP protocol number on the front, 1021 making sure there is room for the address and control fields. */ 1022 if (skb_cow_head(skb, PPP_HDRLEN)) 1023 goto outf; 1024 1025 pp = skb_push(skb, 2); 1026 proto = npindex_to_proto[npi]; 1027 put_unaligned_be16(proto, pp); 1028 1029 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev))); 1030 skb_queue_tail(&ppp->file.xq, skb); 1031 ppp_xmit_process(ppp); 1032 return NETDEV_TX_OK; 1033 1034 outf: 1035 kfree_skb(skb); 1036 ++dev->stats.tx_dropped; 1037 return NETDEV_TX_OK; 1038 } 1039 1040 static int 1041 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 1042 { 1043 struct ppp *ppp = netdev_priv(dev); 1044 int err = -EFAULT; 1045 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data; 1046 struct ppp_stats stats; 1047 struct ppp_comp_stats cstats; 1048 char *vers; 1049 1050 switch (cmd) { 1051 case SIOCGPPPSTATS: 1052 ppp_get_stats(ppp, &stats); 1053 if (copy_to_user(addr, &stats, sizeof(stats))) 1054 break; 1055 err = 0; 1056 break; 1057 1058 case SIOCGPPPCSTATS: 1059 memset(&cstats, 0, sizeof(cstats)); 1060 if (ppp->xc_state) 1061 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c); 1062 if (ppp->rc_state) 1063 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d); 1064 if (copy_to_user(addr, &cstats, sizeof(cstats))) 1065 break; 1066 err = 0; 1067 break; 1068 1069 case SIOCGPPPVER: 1070 vers = PPP_VERSION; 1071 if (copy_to_user(addr, vers, strlen(vers) + 1)) 1072 break; 1073 err = 0; 1074 break; 1075 1076 default: 1077 err = -EINVAL; 1078 } 1079 1080 return err; 1081 } 1082 1083 static struct rtnl_link_stats64* 1084 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64) 1085 { 1086 struct ppp *ppp = netdev_priv(dev); 1087 1088 ppp_recv_lock(ppp); 1089 stats64->rx_packets = ppp->stats64.rx_packets; 1090 stats64->rx_bytes = ppp->stats64.rx_bytes; 1091 ppp_recv_unlock(ppp); 1092 1093 ppp_xmit_lock(ppp); 1094 stats64->tx_packets = ppp->stats64.tx_packets; 1095 stats64->tx_bytes = ppp->stats64.tx_bytes; 1096 ppp_xmit_unlock(ppp); 1097 1098 stats64->rx_errors = dev->stats.rx_errors; 1099 stats64->tx_errors = dev->stats.tx_errors; 1100 stats64->rx_dropped = dev->stats.rx_dropped; 1101 stats64->tx_dropped = dev->stats.tx_dropped; 1102 stats64->rx_length_errors = dev->stats.rx_length_errors; 1103 1104 return stats64; 1105 } 1106 1107 static struct lock_class_key ppp_tx_busylock; 1108 static int ppp_dev_init(struct net_device *dev) 1109 { 1110 dev->qdisc_tx_busylock = &ppp_tx_busylock; 1111 return 0; 1112 } 1113 1114 static void ppp_dev_uninit(struct net_device *dev) 1115 { 1116 struct ppp *ppp = netdev_priv(dev); 1117 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 1118 1119 ppp_lock(ppp); 1120 ppp->closing = 1; 1121 ppp_unlock(ppp); 1122 1123 mutex_lock(&pn->all_ppp_mutex); 1124 unit_put(&pn->units_idr, ppp->file.index); 1125 mutex_unlock(&pn->all_ppp_mutex); 1126 1127 ppp->owner = NULL; 1128 1129 ppp->file.dead = 1; 1130 wake_up_interruptible(&ppp->file.rwait); 1131 } 1132 1133 static const struct net_device_ops ppp_netdev_ops = { 1134 .ndo_init = ppp_dev_init, 1135 .ndo_uninit = ppp_dev_uninit, 1136 .ndo_start_xmit = ppp_start_xmit, 1137 .ndo_do_ioctl = ppp_net_ioctl, 1138 .ndo_get_stats64 = ppp_get_stats64, 1139 }; 1140 1141 static void ppp_setup(struct net_device *dev) 1142 { 1143 dev->netdev_ops = &ppp_netdev_ops; 1144 dev->hard_header_len = PPP_HDRLEN; 1145 dev->mtu = PPP_MRU; 1146 dev->addr_len = 0; 1147 dev->tx_queue_len = 3; 1148 dev->type = ARPHRD_PPP; 1149 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 1150 netif_keep_dst(dev); 1151 } 1152 1153 /* 1154 * Transmit-side routines. 1155 */ 1156 1157 /* 1158 * Called to do any work queued up on the transmit side 1159 * that can now be done. 1160 */ 1161 static void 1162 ppp_xmit_process(struct ppp *ppp) 1163 { 1164 struct sk_buff *skb; 1165 1166 ppp_xmit_lock(ppp); 1167 if (!ppp->closing) { 1168 ppp_push(ppp); 1169 while (!ppp->xmit_pending && 1170 (skb = skb_dequeue(&ppp->file.xq))) 1171 ppp_send_frame(ppp, skb); 1172 /* If there's no work left to do, tell the core net 1173 code that we can accept some more. */ 1174 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq)) 1175 netif_wake_queue(ppp->dev); 1176 else 1177 netif_stop_queue(ppp->dev); 1178 } 1179 ppp_xmit_unlock(ppp); 1180 } 1181 1182 static inline struct sk_buff * 1183 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) 1184 { 1185 struct sk_buff *new_skb; 1186 int len; 1187 int new_skb_size = ppp->dev->mtu + 1188 ppp->xcomp->comp_extra + ppp->dev->hard_header_len; 1189 int compressor_skb_size = ppp->dev->mtu + 1190 ppp->xcomp->comp_extra + PPP_HDRLEN; 1191 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC); 1192 if (!new_skb) { 1193 if (net_ratelimit()) 1194 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n"); 1195 return NULL; 1196 } 1197 if (ppp->dev->hard_header_len > PPP_HDRLEN) 1198 skb_reserve(new_skb, 1199 ppp->dev->hard_header_len - PPP_HDRLEN); 1200 1201 /* compressor still expects A/C bytes in hdr */ 1202 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, 1203 new_skb->data, skb->len + 2, 1204 compressor_skb_size); 1205 if (len > 0 && (ppp->flags & SC_CCP_UP)) { 1206 consume_skb(skb); 1207 skb = new_skb; 1208 skb_put(skb, len); 1209 skb_pull(skb, 2); /* pull off A/C bytes */ 1210 } else if (len == 0) { 1211 /* didn't compress, or CCP not up yet */ 1212 consume_skb(new_skb); 1213 new_skb = skb; 1214 } else { 1215 /* 1216 * (len < 0) 1217 * MPPE requires that we do not send unencrypted 1218 * frames. The compressor will return -1 if we 1219 * should drop the frame. We cannot simply test 1220 * the compress_proto because MPPE and MPPC share 1221 * the same number. 1222 */ 1223 if (net_ratelimit()) 1224 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n"); 1225 kfree_skb(skb); 1226 consume_skb(new_skb); 1227 new_skb = NULL; 1228 } 1229 return new_skb; 1230 } 1231 1232 /* 1233 * Compress and send a frame. 1234 * The caller should have locked the xmit path, 1235 * and xmit_pending should be 0. 1236 */ 1237 static void 1238 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) 1239 { 1240 int proto = PPP_PROTO(skb); 1241 struct sk_buff *new_skb; 1242 int len; 1243 unsigned char *cp; 1244 1245 if (proto < 0x8000) { 1246 #ifdef CONFIG_PPP_FILTER 1247 /* check if we should pass this packet */ 1248 /* the filter instructions are constructed assuming 1249 a four-byte PPP header on each packet */ 1250 *skb_push(skb, 2) = 1; 1251 if (ppp->pass_filter && 1252 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 1253 if (ppp->debug & 1) 1254 netdev_printk(KERN_DEBUG, ppp->dev, 1255 "PPP: outbound frame " 1256 "not passed\n"); 1257 kfree_skb(skb); 1258 return; 1259 } 1260 /* if this packet passes the active filter, record the time */ 1261 if (!(ppp->active_filter && 1262 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 1263 ppp->last_xmit = jiffies; 1264 skb_pull(skb, 2); 1265 #else 1266 /* for data packets, record the time */ 1267 ppp->last_xmit = jiffies; 1268 #endif /* CONFIG_PPP_FILTER */ 1269 } 1270 1271 ++ppp->stats64.tx_packets; 1272 ppp->stats64.tx_bytes += skb->len - 2; 1273 1274 switch (proto) { 1275 case PPP_IP: 1276 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0) 1277 break; 1278 /* try to do VJ TCP header compression */ 1279 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2, 1280 GFP_ATOMIC); 1281 if (!new_skb) { 1282 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n"); 1283 goto drop; 1284 } 1285 skb_reserve(new_skb, ppp->dev->hard_header_len - 2); 1286 cp = skb->data + 2; 1287 len = slhc_compress(ppp->vj, cp, skb->len - 2, 1288 new_skb->data + 2, &cp, 1289 !(ppp->flags & SC_NO_TCP_CCID)); 1290 if (cp == skb->data + 2) { 1291 /* didn't compress */ 1292 consume_skb(new_skb); 1293 } else { 1294 if (cp[0] & SL_TYPE_COMPRESSED_TCP) { 1295 proto = PPP_VJC_COMP; 1296 cp[0] &= ~SL_TYPE_COMPRESSED_TCP; 1297 } else { 1298 proto = PPP_VJC_UNCOMP; 1299 cp[0] = skb->data[2]; 1300 } 1301 consume_skb(skb); 1302 skb = new_skb; 1303 cp = skb_put(skb, len + 2); 1304 cp[0] = 0; 1305 cp[1] = proto; 1306 } 1307 break; 1308 1309 case PPP_CCP: 1310 /* peek at outbound CCP frames */ 1311 ppp_ccp_peek(ppp, skb, 0); 1312 break; 1313 } 1314 1315 /* try to do packet compression */ 1316 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state && 1317 proto != PPP_LCP && proto != PPP_CCP) { 1318 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) { 1319 if (net_ratelimit()) 1320 netdev_err(ppp->dev, 1321 "ppp: compression required but " 1322 "down - pkt dropped.\n"); 1323 goto drop; 1324 } 1325 skb = pad_compress_skb(ppp, skb); 1326 if (!skb) 1327 goto drop; 1328 } 1329 1330 /* 1331 * If we are waiting for traffic (demand dialling), 1332 * queue it up for pppd to receive. 1333 */ 1334 if (ppp->flags & SC_LOOP_TRAFFIC) { 1335 if (ppp->file.rq.qlen > PPP_MAX_RQLEN) 1336 goto drop; 1337 skb_queue_tail(&ppp->file.rq, skb); 1338 wake_up_interruptible(&ppp->file.rwait); 1339 return; 1340 } 1341 1342 ppp->xmit_pending = skb; 1343 ppp_push(ppp); 1344 return; 1345 1346 drop: 1347 kfree_skb(skb); 1348 ++ppp->dev->stats.tx_errors; 1349 } 1350 1351 /* 1352 * Try to send the frame in xmit_pending. 1353 * The caller should have the xmit path locked. 1354 */ 1355 static void 1356 ppp_push(struct ppp *ppp) 1357 { 1358 struct list_head *list; 1359 struct channel *pch; 1360 struct sk_buff *skb = ppp->xmit_pending; 1361 1362 if (!skb) 1363 return; 1364 1365 list = &ppp->channels; 1366 if (list_empty(list)) { 1367 /* nowhere to send the packet, just drop it */ 1368 ppp->xmit_pending = NULL; 1369 kfree_skb(skb); 1370 return; 1371 } 1372 1373 if ((ppp->flags & SC_MULTILINK) == 0) { 1374 /* not doing multilink: send it down the first channel */ 1375 list = list->next; 1376 pch = list_entry(list, struct channel, clist); 1377 1378 spin_lock_bh(&pch->downl); 1379 if (pch->chan) { 1380 if (pch->chan->ops->start_xmit(pch->chan, skb)) 1381 ppp->xmit_pending = NULL; 1382 } else { 1383 /* channel got unregistered */ 1384 kfree_skb(skb); 1385 ppp->xmit_pending = NULL; 1386 } 1387 spin_unlock_bh(&pch->downl); 1388 return; 1389 } 1390 1391 #ifdef CONFIG_PPP_MULTILINK 1392 /* Multilink: fragment the packet over as many links 1393 as can take the packet at the moment. */ 1394 if (!ppp_mp_explode(ppp, skb)) 1395 return; 1396 #endif /* CONFIG_PPP_MULTILINK */ 1397 1398 ppp->xmit_pending = NULL; 1399 kfree_skb(skb); 1400 } 1401 1402 #ifdef CONFIG_PPP_MULTILINK 1403 static bool mp_protocol_compress __read_mostly = true; 1404 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR); 1405 MODULE_PARM_DESC(mp_protocol_compress, 1406 "compress protocol id in multilink fragments"); 1407 1408 /* 1409 * Divide a packet to be transmitted into fragments and 1410 * send them out the individual links. 1411 */ 1412 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb) 1413 { 1414 int len, totlen; 1415 int i, bits, hdrlen, mtu; 1416 int flen; 1417 int navail, nfree, nzero; 1418 int nbigger; 1419 int totspeed; 1420 int totfree; 1421 unsigned char *p, *q; 1422 struct list_head *list; 1423 struct channel *pch; 1424 struct sk_buff *frag; 1425 struct ppp_channel *chan; 1426 1427 totspeed = 0; /*total bitrate of the bundle*/ 1428 nfree = 0; /* # channels which have no packet already queued */ 1429 navail = 0; /* total # of usable channels (not deregistered) */ 1430 nzero = 0; /* number of channels with zero speed associated*/ 1431 totfree = 0; /*total # of channels available and 1432 *having no queued packets before 1433 *starting the fragmentation*/ 1434 1435 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1436 i = 0; 1437 list_for_each_entry(pch, &ppp->channels, clist) { 1438 if (pch->chan) { 1439 pch->avail = 1; 1440 navail++; 1441 pch->speed = pch->chan->speed; 1442 } else { 1443 pch->avail = 0; 1444 } 1445 if (pch->avail) { 1446 if (skb_queue_empty(&pch->file.xq) || 1447 !pch->had_frag) { 1448 if (pch->speed == 0) 1449 nzero++; 1450 else 1451 totspeed += pch->speed; 1452 1453 pch->avail = 2; 1454 ++nfree; 1455 ++totfree; 1456 } 1457 if (!pch->had_frag && i < ppp->nxchan) 1458 ppp->nxchan = i; 1459 } 1460 ++i; 1461 } 1462 /* 1463 * Don't start sending this packet unless at least half of 1464 * the channels are free. This gives much better TCP 1465 * performance if we have a lot of channels. 1466 */ 1467 if (nfree == 0 || nfree < navail / 2) 1468 return 0; /* can't take now, leave it in xmit_pending */ 1469 1470 /* Do protocol field compression */ 1471 p = skb->data; 1472 len = skb->len; 1473 if (*p == 0 && mp_protocol_compress) { 1474 ++p; 1475 --len; 1476 } 1477 1478 totlen = len; 1479 nbigger = len % nfree; 1480 1481 /* skip to the channel after the one we last used 1482 and start at that one */ 1483 list = &ppp->channels; 1484 for (i = 0; i < ppp->nxchan; ++i) { 1485 list = list->next; 1486 if (list == &ppp->channels) { 1487 i = 0; 1488 break; 1489 } 1490 } 1491 1492 /* create a fragment for each channel */ 1493 bits = B; 1494 while (len > 0) { 1495 list = list->next; 1496 if (list == &ppp->channels) { 1497 i = 0; 1498 continue; 1499 } 1500 pch = list_entry(list, struct channel, clist); 1501 ++i; 1502 if (!pch->avail) 1503 continue; 1504 1505 /* 1506 * Skip this channel if it has a fragment pending already and 1507 * we haven't given a fragment to all of the free channels. 1508 */ 1509 if (pch->avail == 1) { 1510 if (nfree > 0) 1511 continue; 1512 } else { 1513 pch->avail = 1; 1514 } 1515 1516 /* check the channel's mtu and whether it is still attached. */ 1517 spin_lock_bh(&pch->downl); 1518 if (pch->chan == NULL) { 1519 /* can't use this channel, it's being deregistered */ 1520 if (pch->speed == 0) 1521 nzero--; 1522 else 1523 totspeed -= pch->speed; 1524 1525 spin_unlock_bh(&pch->downl); 1526 pch->avail = 0; 1527 totlen = len; 1528 totfree--; 1529 nfree--; 1530 if (--navail == 0) 1531 break; 1532 continue; 1533 } 1534 1535 /* 1536 *if the channel speed is not set divide 1537 *the packet evenly among the free channels; 1538 *otherwise divide it according to the speed 1539 *of the channel we are going to transmit on 1540 */ 1541 flen = len; 1542 if (nfree > 0) { 1543 if (pch->speed == 0) { 1544 flen = len/nfree; 1545 if (nbigger > 0) { 1546 flen++; 1547 nbigger--; 1548 } 1549 } else { 1550 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) / 1551 ((totspeed*totfree)/pch->speed)) - hdrlen; 1552 if (nbigger > 0) { 1553 flen += ((totfree - nzero)*pch->speed)/totspeed; 1554 nbigger -= ((totfree - nzero)*pch->speed)/ 1555 totspeed; 1556 } 1557 } 1558 nfree--; 1559 } 1560 1561 /* 1562 *check if we are on the last channel or 1563 *we exceded the length of the data to 1564 *fragment 1565 */ 1566 if ((nfree <= 0) || (flen > len)) 1567 flen = len; 1568 /* 1569 *it is not worth to tx on slow channels: 1570 *in that case from the resulting flen according to the 1571 *above formula will be equal or less than zero. 1572 *Skip the channel in this case 1573 */ 1574 if (flen <= 0) { 1575 pch->avail = 2; 1576 spin_unlock_bh(&pch->downl); 1577 continue; 1578 } 1579 1580 /* 1581 * hdrlen includes the 2-byte PPP protocol field, but the 1582 * MTU counts only the payload excluding the protocol field. 1583 * (RFC1661 Section 2) 1584 */ 1585 mtu = pch->chan->mtu - (hdrlen - 2); 1586 if (mtu < 4) 1587 mtu = 4; 1588 if (flen > mtu) 1589 flen = mtu; 1590 if (flen == len) 1591 bits |= E; 1592 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC); 1593 if (!frag) 1594 goto noskb; 1595 q = skb_put(frag, flen + hdrlen); 1596 1597 /* make the MP header */ 1598 put_unaligned_be16(PPP_MP, q); 1599 if (ppp->flags & SC_MP_XSHORTSEQ) { 1600 q[2] = bits + ((ppp->nxseq >> 8) & 0xf); 1601 q[3] = ppp->nxseq; 1602 } else { 1603 q[2] = bits; 1604 q[3] = ppp->nxseq >> 16; 1605 q[4] = ppp->nxseq >> 8; 1606 q[5] = ppp->nxseq; 1607 } 1608 1609 memcpy(q + hdrlen, p, flen); 1610 1611 /* try to send it down the channel */ 1612 chan = pch->chan; 1613 if (!skb_queue_empty(&pch->file.xq) || 1614 !chan->ops->start_xmit(chan, frag)) 1615 skb_queue_tail(&pch->file.xq, frag); 1616 pch->had_frag = 1; 1617 p += flen; 1618 len -= flen; 1619 ++ppp->nxseq; 1620 bits = 0; 1621 spin_unlock_bh(&pch->downl); 1622 } 1623 ppp->nxchan = i; 1624 1625 return 1; 1626 1627 noskb: 1628 spin_unlock_bh(&pch->downl); 1629 if (ppp->debug & 1) 1630 netdev_err(ppp->dev, "PPP: no memory (fragment)\n"); 1631 ++ppp->dev->stats.tx_errors; 1632 ++ppp->nxseq; 1633 return 1; /* abandon the frame */ 1634 } 1635 #endif /* CONFIG_PPP_MULTILINK */ 1636 1637 /* 1638 * Try to send data out on a channel. 1639 */ 1640 static void 1641 ppp_channel_push(struct channel *pch) 1642 { 1643 struct sk_buff *skb; 1644 struct ppp *ppp; 1645 1646 spin_lock_bh(&pch->downl); 1647 if (pch->chan) { 1648 while (!skb_queue_empty(&pch->file.xq)) { 1649 skb = skb_dequeue(&pch->file.xq); 1650 if (!pch->chan->ops->start_xmit(pch->chan, skb)) { 1651 /* put the packet back and try again later */ 1652 skb_queue_head(&pch->file.xq, skb); 1653 break; 1654 } 1655 } 1656 } else { 1657 /* channel got deregistered */ 1658 skb_queue_purge(&pch->file.xq); 1659 } 1660 spin_unlock_bh(&pch->downl); 1661 /* see if there is anything from the attached unit to be sent */ 1662 if (skb_queue_empty(&pch->file.xq)) { 1663 read_lock_bh(&pch->upl); 1664 ppp = pch->ppp; 1665 if (ppp) 1666 ppp_xmit_process(ppp); 1667 read_unlock_bh(&pch->upl); 1668 } 1669 } 1670 1671 /* 1672 * Receive-side routines. 1673 */ 1674 1675 struct ppp_mp_skb_parm { 1676 u32 sequence; 1677 u8 BEbits; 1678 }; 1679 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb)) 1680 1681 static inline void 1682 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1683 { 1684 ppp_recv_lock(ppp); 1685 if (!ppp->closing) 1686 ppp_receive_frame(ppp, skb, pch); 1687 else 1688 kfree_skb(skb); 1689 ppp_recv_unlock(ppp); 1690 } 1691 1692 void 1693 ppp_input(struct ppp_channel *chan, struct sk_buff *skb) 1694 { 1695 struct channel *pch = chan->ppp; 1696 int proto; 1697 1698 if (!pch) { 1699 kfree_skb(skb); 1700 return; 1701 } 1702 1703 read_lock_bh(&pch->upl); 1704 if (!pskb_may_pull(skb, 2)) { 1705 kfree_skb(skb); 1706 if (pch->ppp) { 1707 ++pch->ppp->dev->stats.rx_length_errors; 1708 ppp_receive_error(pch->ppp); 1709 } 1710 goto done; 1711 } 1712 1713 proto = PPP_PROTO(skb); 1714 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) { 1715 /* put it on the channel queue */ 1716 skb_queue_tail(&pch->file.rq, skb); 1717 /* drop old frames if queue too long */ 1718 while (pch->file.rq.qlen > PPP_MAX_RQLEN && 1719 (skb = skb_dequeue(&pch->file.rq))) 1720 kfree_skb(skb); 1721 wake_up_interruptible(&pch->file.rwait); 1722 } else { 1723 ppp_do_recv(pch->ppp, skb, pch); 1724 } 1725 1726 done: 1727 read_unlock_bh(&pch->upl); 1728 } 1729 1730 /* Put a 0-length skb in the receive queue as an error indication */ 1731 void 1732 ppp_input_error(struct ppp_channel *chan, int code) 1733 { 1734 struct channel *pch = chan->ppp; 1735 struct sk_buff *skb; 1736 1737 if (!pch) 1738 return; 1739 1740 read_lock_bh(&pch->upl); 1741 if (pch->ppp) { 1742 skb = alloc_skb(0, GFP_ATOMIC); 1743 if (skb) { 1744 skb->len = 0; /* probably unnecessary */ 1745 skb->cb[0] = code; 1746 ppp_do_recv(pch->ppp, skb, pch); 1747 } 1748 } 1749 read_unlock_bh(&pch->upl); 1750 } 1751 1752 /* 1753 * We come in here to process a received frame. 1754 * The receive side of the ppp unit is locked. 1755 */ 1756 static void 1757 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1758 { 1759 /* note: a 0-length skb is used as an error indication */ 1760 if (skb->len > 0) { 1761 skb_checksum_complete_unset(skb); 1762 #ifdef CONFIG_PPP_MULTILINK 1763 /* XXX do channel-level decompression here */ 1764 if (PPP_PROTO(skb) == PPP_MP) 1765 ppp_receive_mp_frame(ppp, skb, pch); 1766 else 1767 #endif /* CONFIG_PPP_MULTILINK */ 1768 ppp_receive_nonmp_frame(ppp, skb); 1769 } else { 1770 kfree_skb(skb); 1771 ppp_receive_error(ppp); 1772 } 1773 } 1774 1775 static void 1776 ppp_receive_error(struct ppp *ppp) 1777 { 1778 ++ppp->dev->stats.rx_errors; 1779 if (ppp->vj) 1780 slhc_toss(ppp->vj); 1781 } 1782 1783 static void 1784 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) 1785 { 1786 struct sk_buff *ns; 1787 int proto, len, npi; 1788 1789 /* 1790 * Decompress the frame, if compressed. 1791 * Note that some decompressors need to see uncompressed frames 1792 * that come in as well as compressed frames. 1793 */ 1794 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) && 1795 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0) 1796 skb = ppp_decompress_frame(ppp, skb); 1797 1798 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR) 1799 goto err; 1800 1801 proto = PPP_PROTO(skb); 1802 switch (proto) { 1803 case PPP_VJC_COMP: 1804 /* decompress VJ compressed packets */ 1805 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 1806 goto err; 1807 1808 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) { 1809 /* copy to a new sk_buff with more tailroom */ 1810 ns = dev_alloc_skb(skb->len + 128); 1811 if (!ns) { 1812 netdev_err(ppp->dev, "PPP: no memory " 1813 "(VJ decomp)\n"); 1814 goto err; 1815 } 1816 skb_reserve(ns, 2); 1817 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len); 1818 consume_skb(skb); 1819 skb = ns; 1820 } 1821 else 1822 skb->ip_summed = CHECKSUM_NONE; 1823 1824 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2); 1825 if (len <= 0) { 1826 netdev_printk(KERN_DEBUG, ppp->dev, 1827 "PPP: VJ decompression error\n"); 1828 goto err; 1829 } 1830 len += 2; 1831 if (len > skb->len) 1832 skb_put(skb, len - skb->len); 1833 else if (len < skb->len) 1834 skb_trim(skb, len); 1835 proto = PPP_IP; 1836 break; 1837 1838 case PPP_VJC_UNCOMP: 1839 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 1840 goto err; 1841 1842 /* Until we fix the decompressor need to make sure 1843 * data portion is linear. 1844 */ 1845 if (!pskb_may_pull(skb, skb->len)) 1846 goto err; 1847 1848 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) { 1849 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n"); 1850 goto err; 1851 } 1852 proto = PPP_IP; 1853 break; 1854 1855 case PPP_CCP: 1856 ppp_ccp_peek(ppp, skb, 1); 1857 break; 1858 } 1859 1860 ++ppp->stats64.rx_packets; 1861 ppp->stats64.rx_bytes += skb->len - 2; 1862 1863 npi = proto_to_npindex(proto); 1864 if (npi < 0) { 1865 /* control or unknown frame - pass it to pppd */ 1866 skb_queue_tail(&ppp->file.rq, skb); 1867 /* limit queue length by dropping old frames */ 1868 while (ppp->file.rq.qlen > PPP_MAX_RQLEN && 1869 (skb = skb_dequeue(&ppp->file.rq))) 1870 kfree_skb(skb); 1871 /* wake up any process polling or blocking on read */ 1872 wake_up_interruptible(&ppp->file.rwait); 1873 1874 } else { 1875 /* network protocol frame - give it to the kernel */ 1876 1877 #ifdef CONFIG_PPP_FILTER 1878 /* check if the packet passes the pass and active filters */ 1879 /* the filter instructions are constructed assuming 1880 a four-byte PPP header on each packet */ 1881 if (ppp->pass_filter || ppp->active_filter) { 1882 if (skb_unclone(skb, GFP_ATOMIC)) 1883 goto err; 1884 1885 *skb_push(skb, 2) = 0; 1886 if (ppp->pass_filter && 1887 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 1888 if (ppp->debug & 1) 1889 netdev_printk(KERN_DEBUG, ppp->dev, 1890 "PPP: inbound frame " 1891 "not passed\n"); 1892 kfree_skb(skb); 1893 return; 1894 } 1895 if (!(ppp->active_filter && 1896 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 1897 ppp->last_recv = jiffies; 1898 __skb_pull(skb, 2); 1899 } else 1900 #endif /* CONFIG_PPP_FILTER */ 1901 ppp->last_recv = jiffies; 1902 1903 if ((ppp->dev->flags & IFF_UP) == 0 || 1904 ppp->npmode[npi] != NPMODE_PASS) { 1905 kfree_skb(skb); 1906 } else { 1907 /* chop off protocol */ 1908 skb_pull_rcsum(skb, 2); 1909 skb->dev = ppp->dev; 1910 skb->protocol = htons(npindex_to_ethertype[npi]); 1911 skb_reset_mac_header(skb); 1912 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, 1913 dev_net(ppp->dev))); 1914 netif_rx(skb); 1915 } 1916 } 1917 return; 1918 1919 err: 1920 kfree_skb(skb); 1921 ppp_receive_error(ppp); 1922 } 1923 1924 static struct sk_buff * 1925 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb) 1926 { 1927 int proto = PPP_PROTO(skb); 1928 struct sk_buff *ns; 1929 int len; 1930 1931 /* Until we fix all the decompressor's need to make sure 1932 * data portion is linear. 1933 */ 1934 if (!pskb_may_pull(skb, skb->len)) 1935 goto err; 1936 1937 if (proto == PPP_COMP) { 1938 int obuff_size; 1939 1940 switch(ppp->rcomp->compress_proto) { 1941 case CI_MPPE: 1942 obuff_size = ppp->mru + PPP_HDRLEN + 1; 1943 break; 1944 default: 1945 obuff_size = ppp->mru + PPP_HDRLEN; 1946 break; 1947 } 1948 1949 ns = dev_alloc_skb(obuff_size); 1950 if (!ns) { 1951 netdev_err(ppp->dev, "ppp_decompress_frame: " 1952 "no memory\n"); 1953 goto err; 1954 } 1955 /* the decompressor still expects the A/C bytes in the hdr */ 1956 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2, 1957 skb->len + 2, ns->data, obuff_size); 1958 if (len < 0) { 1959 /* Pass the compressed frame to pppd as an 1960 error indication. */ 1961 if (len == DECOMP_FATALERROR) 1962 ppp->rstate |= SC_DC_FERROR; 1963 kfree_skb(ns); 1964 goto err; 1965 } 1966 1967 consume_skb(skb); 1968 skb = ns; 1969 skb_put(skb, len); 1970 skb_pull(skb, 2); /* pull off the A/C bytes */ 1971 1972 } else { 1973 /* Uncompressed frame - pass to decompressor so it 1974 can update its dictionary if necessary. */ 1975 if (ppp->rcomp->incomp) 1976 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2, 1977 skb->len + 2); 1978 } 1979 1980 return skb; 1981 1982 err: 1983 ppp->rstate |= SC_DC_ERROR; 1984 ppp_receive_error(ppp); 1985 return skb; 1986 } 1987 1988 #ifdef CONFIG_PPP_MULTILINK 1989 /* 1990 * Receive a multilink frame. 1991 * We put it on the reconstruction queue and then pull off 1992 * as many completed frames as we can. 1993 */ 1994 static void 1995 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1996 { 1997 u32 mask, seq; 1998 struct channel *ch; 1999 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 2000 2001 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0) 2002 goto err; /* no good, throw it away */ 2003 2004 /* Decode sequence number and begin/end bits */ 2005 if (ppp->flags & SC_MP_SHORTSEQ) { 2006 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3]; 2007 mask = 0xfff; 2008 } else { 2009 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5]; 2010 mask = 0xffffff; 2011 } 2012 PPP_MP_CB(skb)->BEbits = skb->data[2]; 2013 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */ 2014 2015 /* 2016 * Do protocol ID decompression on the first fragment of each packet. 2017 */ 2018 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1)) 2019 *skb_push(skb, 1) = 0; 2020 2021 /* 2022 * Expand sequence number to 32 bits, making it as close 2023 * as possible to ppp->minseq. 2024 */ 2025 seq |= ppp->minseq & ~mask; 2026 if ((int)(ppp->minseq - seq) > (int)(mask >> 1)) 2027 seq += mask + 1; 2028 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1)) 2029 seq -= mask + 1; /* should never happen */ 2030 PPP_MP_CB(skb)->sequence = seq; 2031 pch->lastseq = seq; 2032 2033 /* 2034 * If this packet comes before the next one we were expecting, 2035 * drop it. 2036 */ 2037 if (seq_before(seq, ppp->nextseq)) { 2038 kfree_skb(skb); 2039 ++ppp->dev->stats.rx_dropped; 2040 ppp_receive_error(ppp); 2041 return; 2042 } 2043 2044 /* 2045 * Reevaluate minseq, the minimum over all channels of the 2046 * last sequence number received on each channel. Because of 2047 * the increasing sequence number rule, we know that any fragment 2048 * before `minseq' which hasn't arrived is never going to arrive. 2049 * The list of channels can't change because we have the receive 2050 * side of the ppp unit locked. 2051 */ 2052 list_for_each_entry(ch, &ppp->channels, clist) { 2053 if (seq_before(ch->lastseq, seq)) 2054 seq = ch->lastseq; 2055 } 2056 if (seq_before(ppp->minseq, seq)) 2057 ppp->minseq = seq; 2058 2059 /* Put the fragment on the reconstruction queue */ 2060 ppp_mp_insert(ppp, skb); 2061 2062 /* If the queue is getting long, don't wait any longer for packets 2063 before the start of the queue. */ 2064 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) { 2065 struct sk_buff *mskb = skb_peek(&ppp->mrq); 2066 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence)) 2067 ppp->minseq = PPP_MP_CB(mskb)->sequence; 2068 } 2069 2070 /* Pull completed packets off the queue and receive them. */ 2071 while ((skb = ppp_mp_reconstruct(ppp))) { 2072 if (pskb_may_pull(skb, 2)) 2073 ppp_receive_nonmp_frame(ppp, skb); 2074 else { 2075 ++ppp->dev->stats.rx_length_errors; 2076 kfree_skb(skb); 2077 ppp_receive_error(ppp); 2078 } 2079 } 2080 2081 return; 2082 2083 err: 2084 kfree_skb(skb); 2085 ppp_receive_error(ppp); 2086 } 2087 2088 /* 2089 * Insert a fragment on the MP reconstruction queue. 2090 * The queue is ordered by increasing sequence number. 2091 */ 2092 static void 2093 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb) 2094 { 2095 struct sk_buff *p; 2096 struct sk_buff_head *list = &ppp->mrq; 2097 u32 seq = PPP_MP_CB(skb)->sequence; 2098 2099 /* N.B. we don't need to lock the list lock because we have the 2100 ppp unit receive-side lock. */ 2101 skb_queue_walk(list, p) { 2102 if (seq_before(seq, PPP_MP_CB(p)->sequence)) 2103 break; 2104 } 2105 __skb_queue_before(list, p, skb); 2106 } 2107 2108 /* 2109 * Reconstruct a packet from the MP fragment queue. 2110 * We go through increasing sequence numbers until we find a 2111 * complete packet, or we get to the sequence number for a fragment 2112 * which hasn't arrived but might still do so. 2113 */ 2114 static struct sk_buff * 2115 ppp_mp_reconstruct(struct ppp *ppp) 2116 { 2117 u32 seq = ppp->nextseq; 2118 u32 minseq = ppp->minseq; 2119 struct sk_buff_head *list = &ppp->mrq; 2120 struct sk_buff *p, *tmp; 2121 struct sk_buff *head, *tail; 2122 struct sk_buff *skb = NULL; 2123 int lost = 0, len = 0; 2124 2125 if (ppp->mrru == 0) /* do nothing until mrru is set */ 2126 return NULL; 2127 head = list->next; 2128 tail = NULL; 2129 skb_queue_walk_safe(list, p, tmp) { 2130 again: 2131 if (seq_before(PPP_MP_CB(p)->sequence, seq)) { 2132 /* this can't happen, anyway ignore the skb */ 2133 netdev_err(ppp->dev, "ppp_mp_reconstruct bad " 2134 "seq %u < %u\n", 2135 PPP_MP_CB(p)->sequence, seq); 2136 __skb_unlink(p, list); 2137 kfree_skb(p); 2138 continue; 2139 } 2140 if (PPP_MP_CB(p)->sequence != seq) { 2141 u32 oldseq; 2142 /* Fragment `seq' is missing. If it is after 2143 minseq, it might arrive later, so stop here. */ 2144 if (seq_after(seq, minseq)) 2145 break; 2146 /* Fragment `seq' is lost, keep going. */ 2147 lost = 1; 2148 oldseq = seq; 2149 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)? 2150 minseq + 1: PPP_MP_CB(p)->sequence; 2151 2152 if (ppp->debug & 1) 2153 netdev_printk(KERN_DEBUG, ppp->dev, 2154 "lost frag %u..%u\n", 2155 oldseq, seq-1); 2156 2157 goto again; 2158 } 2159 2160 /* 2161 * At this point we know that all the fragments from 2162 * ppp->nextseq to seq are either present or lost. 2163 * Also, there are no complete packets in the queue 2164 * that have no missing fragments and end before this 2165 * fragment. 2166 */ 2167 2168 /* B bit set indicates this fragment starts a packet */ 2169 if (PPP_MP_CB(p)->BEbits & B) { 2170 head = p; 2171 lost = 0; 2172 len = 0; 2173 } 2174 2175 len += p->len; 2176 2177 /* Got a complete packet yet? */ 2178 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) && 2179 (PPP_MP_CB(head)->BEbits & B)) { 2180 if (len > ppp->mrru + 2) { 2181 ++ppp->dev->stats.rx_length_errors; 2182 netdev_printk(KERN_DEBUG, ppp->dev, 2183 "PPP: reconstructed packet" 2184 " is too long (%d)\n", len); 2185 } else { 2186 tail = p; 2187 break; 2188 } 2189 ppp->nextseq = seq + 1; 2190 } 2191 2192 /* 2193 * If this is the ending fragment of a packet, 2194 * and we haven't found a complete valid packet yet, 2195 * we can discard up to and including this fragment. 2196 */ 2197 if (PPP_MP_CB(p)->BEbits & E) { 2198 struct sk_buff *tmp2; 2199 2200 skb_queue_reverse_walk_from_safe(list, p, tmp2) { 2201 if (ppp->debug & 1) 2202 netdev_printk(KERN_DEBUG, ppp->dev, 2203 "discarding frag %u\n", 2204 PPP_MP_CB(p)->sequence); 2205 __skb_unlink(p, list); 2206 kfree_skb(p); 2207 } 2208 head = skb_peek(list); 2209 if (!head) 2210 break; 2211 } 2212 ++seq; 2213 } 2214 2215 /* If we have a complete packet, copy it all into one skb. */ 2216 if (tail != NULL) { 2217 /* If we have discarded any fragments, 2218 signal a receive error. */ 2219 if (PPP_MP_CB(head)->sequence != ppp->nextseq) { 2220 skb_queue_walk_safe(list, p, tmp) { 2221 if (p == head) 2222 break; 2223 if (ppp->debug & 1) 2224 netdev_printk(KERN_DEBUG, ppp->dev, 2225 "discarding frag %u\n", 2226 PPP_MP_CB(p)->sequence); 2227 __skb_unlink(p, list); 2228 kfree_skb(p); 2229 } 2230 2231 if (ppp->debug & 1) 2232 netdev_printk(KERN_DEBUG, ppp->dev, 2233 " missed pkts %u..%u\n", 2234 ppp->nextseq, 2235 PPP_MP_CB(head)->sequence-1); 2236 ++ppp->dev->stats.rx_dropped; 2237 ppp_receive_error(ppp); 2238 } 2239 2240 skb = head; 2241 if (head != tail) { 2242 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list; 2243 p = skb_queue_next(list, head); 2244 __skb_unlink(skb, list); 2245 skb_queue_walk_from_safe(list, p, tmp) { 2246 __skb_unlink(p, list); 2247 *fragpp = p; 2248 p->next = NULL; 2249 fragpp = &p->next; 2250 2251 skb->len += p->len; 2252 skb->data_len += p->len; 2253 skb->truesize += p->truesize; 2254 2255 if (p == tail) 2256 break; 2257 } 2258 } else { 2259 __skb_unlink(skb, list); 2260 } 2261 2262 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1; 2263 } 2264 2265 return skb; 2266 } 2267 #endif /* CONFIG_PPP_MULTILINK */ 2268 2269 /* 2270 * Channel interface. 2271 */ 2272 2273 /* Create a new, unattached ppp channel. */ 2274 int ppp_register_channel(struct ppp_channel *chan) 2275 { 2276 return ppp_register_net_channel(current->nsproxy->net_ns, chan); 2277 } 2278 2279 /* Create a new, unattached ppp channel for specified net. */ 2280 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan) 2281 { 2282 struct channel *pch; 2283 struct ppp_net *pn; 2284 2285 pch = kzalloc(sizeof(struct channel), GFP_KERNEL); 2286 if (!pch) 2287 return -ENOMEM; 2288 2289 pn = ppp_pernet(net); 2290 2291 pch->ppp = NULL; 2292 pch->chan = chan; 2293 pch->chan_net = net; 2294 chan->ppp = pch; 2295 init_ppp_file(&pch->file, CHANNEL); 2296 pch->file.hdrlen = chan->hdrlen; 2297 #ifdef CONFIG_PPP_MULTILINK 2298 pch->lastseq = -1; 2299 #endif /* CONFIG_PPP_MULTILINK */ 2300 init_rwsem(&pch->chan_sem); 2301 spin_lock_init(&pch->downl); 2302 rwlock_init(&pch->upl); 2303 2304 spin_lock_bh(&pn->all_channels_lock); 2305 pch->file.index = ++pn->last_channel_index; 2306 list_add(&pch->list, &pn->new_channels); 2307 atomic_inc(&channel_count); 2308 spin_unlock_bh(&pn->all_channels_lock); 2309 2310 return 0; 2311 } 2312 2313 /* 2314 * Return the index of a channel. 2315 */ 2316 int ppp_channel_index(struct ppp_channel *chan) 2317 { 2318 struct channel *pch = chan->ppp; 2319 2320 if (pch) 2321 return pch->file.index; 2322 return -1; 2323 } 2324 2325 /* 2326 * Return the PPP unit number to which a channel is connected. 2327 */ 2328 int ppp_unit_number(struct ppp_channel *chan) 2329 { 2330 struct channel *pch = chan->ppp; 2331 int unit = -1; 2332 2333 if (pch) { 2334 read_lock_bh(&pch->upl); 2335 if (pch->ppp) 2336 unit = pch->ppp->file.index; 2337 read_unlock_bh(&pch->upl); 2338 } 2339 return unit; 2340 } 2341 2342 /* 2343 * Return the PPP device interface name of a channel. 2344 */ 2345 char *ppp_dev_name(struct ppp_channel *chan) 2346 { 2347 struct channel *pch = chan->ppp; 2348 char *name = NULL; 2349 2350 if (pch) { 2351 read_lock_bh(&pch->upl); 2352 if (pch->ppp && pch->ppp->dev) 2353 name = pch->ppp->dev->name; 2354 read_unlock_bh(&pch->upl); 2355 } 2356 return name; 2357 } 2358 2359 2360 /* 2361 * Disconnect a channel from the generic layer. 2362 * This must be called in process context. 2363 */ 2364 void 2365 ppp_unregister_channel(struct ppp_channel *chan) 2366 { 2367 struct channel *pch = chan->ppp; 2368 struct ppp_net *pn; 2369 2370 if (!pch) 2371 return; /* should never happen */ 2372 2373 chan->ppp = NULL; 2374 2375 /* 2376 * This ensures that we have returned from any calls into the 2377 * the channel's start_xmit or ioctl routine before we proceed. 2378 */ 2379 down_write(&pch->chan_sem); 2380 spin_lock_bh(&pch->downl); 2381 pch->chan = NULL; 2382 spin_unlock_bh(&pch->downl); 2383 up_write(&pch->chan_sem); 2384 ppp_disconnect_channel(pch); 2385 2386 pn = ppp_pernet(pch->chan_net); 2387 spin_lock_bh(&pn->all_channels_lock); 2388 list_del(&pch->list); 2389 spin_unlock_bh(&pn->all_channels_lock); 2390 2391 pch->file.dead = 1; 2392 wake_up_interruptible(&pch->file.rwait); 2393 if (atomic_dec_and_test(&pch->file.refcnt)) 2394 ppp_destroy_channel(pch); 2395 } 2396 2397 /* 2398 * Callback from a channel when it can accept more to transmit. 2399 * This should be called at BH/softirq level, not interrupt level. 2400 */ 2401 void 2402 ppp_output_wakeup(struct ppp_channel *chan) 2403 { 2404 struct channel *pch = chan->ppp; 2405 2406 if (!pch) 2407 return; 2408 ppp_channel_push(pch); 2409 } 2410 2411 /* 2412 * Compression control. 2413 */ 2414 2415 /* Process the PPPIOCSCOMPRESS ioctl. */ 2416 static int 2417 ppp_set_compress(struct ppp *ppp, unsigned long arg) 2418 { 2419 int err; 2420 struct compressor *cp, *ocomp; 2421 struct ppp_option_data data; 2422 void *state, *ostate; 2423 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH]; 2424 2425 err = -EFAULT; 2426 if (copy_from_user(&data, (void __user *) arg, sizeof(data)) || 2427 (data.length <= CCP_MAX_OPTION_LENGTH && 2428 copy_from_user(ccp_option, (void __user *) data.ptr, data.length))) 2429 goto out; 2430 err = -EINVAL; 2431 if (data.length > CCP_MAX_OPTION_LENGTH || 2432 ccp_option[1] < 2 || ccp_option[1] > data.length) 2433 goto out; 2434 2435 cp = try_then_request_module( 2436 find_compressor(ccp_option[0]), 2437 "ppp-compress-%d", ccp_option[0]); 2438 if (!cp) 2439 goto out; 2440 2441 err = -ENOBUFS; 2442 if (data.transmit) { 2443 state = cp->comp_alloc(ccp_option, data.length); 2444 if (state) { 2445 ppp_xmit_lock(ppp); 2446 ppp->xstate &= ~SC_COMP_RUN; 2447 ocomp = ppp->xcomp; 2448 ostate = ppp->xc_state; 2449 ppp->xcomp = cp; 2450 ppp->xc_state = state; 2451 ppp_xmit_unlock(ppp); 2452 if (ostate) { 2453 ocomp->comp_free(ostate); 2454 module_put(ocomp->owner); 2455 } 2456 err = 0; 2457 } else 2458 module_put(cp->owner); 2459 2460 } else { 2461 state = cp->decomp_alloc(ccp_option, data.length); 2462 if (state) { 2463 ppp_recv_lock(ppp); 2464 ppp->rstate &= ~SC_DECOMP_RUN; 2465 ocomp = ppp->rcomp; 2466 ostate = ppp->rc_state; 2467 ppp->rcomp = cp; 2468 ppp->rc_state = state; 2469 ppp_recv_unlock(ppp); 2470 if (ostate) { 2471 ocomp->decomp_free(ostate); 2472 module_put(ocomp->owner); 2473 } 2474 err = 0; 2475 } else 2476 module_put(cp->owner); 2477 } 2478 2479 out: 2480 return err; 2481 } 2482 2483 /* 2484 * Look at a CCP packet and update our state accordingly. 2485 * We assume the caller has the xmit or recv path locked. 2486 */ 2487 static void 2488 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound) 2489 { 2490 unsigned char *dp; 2491 int len; 2492 2493 if (!pskb_may_pull(skb, CCP_HDRLEN + 2)) 2494 return; /* no header */ 2495 dp = skb->data + 2; 2496 2497 switch (CCP_CODE(dp)) { 2498 case CCP_CONFREQ: 2499 2500 /* A ConfReq starts negotiation of compression 2501 * in one direction of transmission, 2502 * and hence brings it down...but which way? 2503 * 2504 * Remember: 2505 * A ConfReq indicates what the sender would like to receive 2506 */ 2507 if(inbound) 2508 /* He is proposing what I should send */ 2509 ppp->xstate &= ~SC_COMP_RUN; 2510 else 2511 /* I am proposing to what he should send */ 2512 ppp->rstate &= ~SC_DECOMP_RUN; 2513 2514 break; 2515 2516 case CCP_TERMREQ: 2517 case CCP_TERMACK: 2518 /* 2519 * CCP is going down, both directions of transmission 2520 */ 2521 ppp->rstate &= ~SC_DECOMP_RUN; 2522 ppp->xstate &= ~SC_COMP_RUN; 2523 break; 2524 2525 case CCP_CONFACK: 2526 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN) 2527 break; 2528 len = CCP_LENGTH(dp); 2529 if (!pskb_may_pull(skb, len + 2)) 2530 return; /* too short */ 2531 dp += CCP_HDRLEN; 2532 len -= CCP_HDRLEN; 2533 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp)) 2534 break; 2535 if (inbound) { 2536 /* we will start receiving compressed packets */ 2537 if (!ppp->rc_state) 2538 break; 2539 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len, 2540 ppp->file.index, 0, ppp->mru, ppp->debug)) { 2541 ppp->rstate |= SC_DECOMP_RUN; 2542 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR); 2543 } 2544 } else { 2545 /* we will soon start sending compressed packets */ 2546 if (!ppp->xc_state) 2547 break; 2548 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len, 2549 ppp->file.index, 0, ppp->debug)) 2550 ppp->xstate |= SC_COMP_RUN; 2551 } 2552 break; 2553 2554 case CCP_RESETACK: 2555 /* reset the [de]compressor */ 2556 if ((ppp->flags & SC_CCP_UP) == 0) 2557 break; 2558 if (inbound) { 2559 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) { 2560 ppp->rcomp->decomp_reset(ppp->rc_state); 2561 ppp->rstate &= ~SC_DC_ERROR; 2562 } 2563 } else { 2564 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN)) 2565 ppp->xcomp->comp_reset(ppp->xc_state); 2566 } 2567 break; 2568 } 2569 } 2570 2571 /* Free up compression resources. */ 2572 static void 2573 ppp_ccp_closed(struct ppp *ppp) 2574 { 2575 void *xstate, *rstate; 2576 struct compressor *xcomp, *rcomp; 2577 2578 ppp_lock(ppp); 2579 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP); 2580 ppp->xstate = 0; 2581 xcomp = ppp->xcomp; 2582 xstate = ppp->xc_state; 2583 ppp->xc_state = NULL; 2584 ppp->rstate = 0; 2585 rcomp = ppp->rcomp; 2586 rstate = ppp->rc_state; 2587 ppp->rc_state = NULL; 2588 ppp_unlock(ppp); 2589 2590 if (xstate) { 2591 xcomp->comp_free(xstate); 2592 module_put(xcomp->owner); 2593 } 2594 if (rstate) { 2595 rcomp->decomp_free(rstate); 2596 module_put(rcomp->owner); 2597 } 2598 } 2599 2600 /* List of compressors. */ 2601 static LIST_HEAD(compressor_list); 2602 static DEFINE_SPINLOCK(compressor_list_lock); 2603 2604 struct compressor_entry { 2605 struct list_head list; 2606 struct compressor *comp; 2607 }; 2608 2609 static struct compressor_entry * 2610 find_comp_entry(int proto) 2611 { 2612 struct compressor_entry *ce; 2613 2614 list_for_each_entry(ce, &compressor_list, list) { 2615 if (ce->comp->compress_proto == proto) 2616 return ce; 2617 } 2618 return NULL; 2619 } 2620 2621 /* Register a compressor */ 2622 int 2623 ppp_register_compressor(struct compressor *cp) 2624 { 2625 struct compressor_entry *ce; 2626 int ret; 2627 spin_lock(&compressor_list_lock); 2628 ret = -EEXIST; 2629 if (find_comp_entry(cp->compress_proto)) 2630 goto out; 2631 ret = -ENOMEM; 2632 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC); 2633 if (!ce) 2634 goto out; 2635 ret = 0; 2636 ce->comp = cp; 2637 list_add(&ce->list, &compressor_list); 2638 out: 2639 spin_unlock(&compressor_list_lock); 2640 return ret; 2641 } 2642 2643 /* Unregister a compressor */ 2644 void 2645 ppp_unregister_compressor(struct compressor *cp) 2646 { 2647 struct compressor_entry *ce; 2648 2649 spin_lock(&compressor_list_lock); 2650 ce = find_comp_entry(cp->compress_proto); 2651 if (ce && ce->comp == cp) { 2652 list_del(&ce->list); 2653 kfree(ce); 2654 } 2655 spin_unlock(&compressor_list_lock); 2656 } 2657 2658 /* Find a compressor. */ 2659 static struct compressor * 2660 find_compressor(int type) 2661 { 2662 struct compressor_entry *ce; 2663 struct compressor *cp = NULL; 2664 2665 spin_lock(&compressor_list_lock); 2666 ce = find_comp_entry(type); 2667 if (ce) { 2668 cp = ce->comp; 2669 if (!try_module_get(cp->owner)) 2670 cp = NULL; 2671 } 2672 spin_unlock(&compressor_list_lock); 2673 return cp; 2674 } 2675 2676 /* 2677 * Miscelleneous stuff. 2678 */ 2679 2680 static void 2681 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st) 2682 { 2683 struct slcompress *vj = ppp->vj; 2684 2685 memset(st, 0, sizeof(*st)); 2686 st->p.ppp_ipackets = ppp->stats64.rx_packets; 2687 st->p.ppp_ierrors = ppp->dev->stats.rx_errors; 2688 st->p.ppp_ibytes = ppp->stats64.rx_bytes; 2689 st->p.ppp_opackets = ppp->stats64.tx_packets; 2690 st->p.ppp_oerrors = ppp->dev->stats.tx_errors; 2691 st->p.ppp_obytes = ppp->stats64.tx_bytes; 2692 if (!vj) 2693 return; 2694 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed; 2695 st->vj.vjs_compressed = vj->sls_o_compressed; 2696 st->vj.vjs_searches = vj->sls_o_searches; 2697 st->vj.vjs_misses = vj->sls_o_misses; 2698 st->vj.vjs_errorin = vj->sls_i_error; 2699 st->vj.vjs_tossed = vj->sls_i_tossed; 2700 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed; 2701 st->vj.vjs_compressedin = vj->sls_i_compressed; 2702 } 2703 2704 /* 2705 * Stuff for handling the lists of ppp units and channels 2706 * and for initialization. 2707 */ 2708 2709 /* 2710 * Create a new ppp interface unit. Fails if it can't allocate memory 2711 * or if there is already a unit with the requested number. 2712 * unit == -1 means allocate a new number. 2713 */ 2714 static struct ppp *ppp_create_interface(struct net *net, int unit, 2715 struct file *file, int *retp) 2716 { 2717 struct ppp *ppp; 2718 struct ppp_net *pn; 2719 struct net_device *dev = NULL; 2720 int ret = -ENOMEM; 2721 int i; 2722 2723 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_UNKNOWN, 2724 ppp_setup); 2725 if (!dev) 2726 goto out1; 2727 2728 pn = ppp_pernet(net); 2729 2730 ppp = netdev_priv(dev); 2731 ppp->dev = dev; 2732 ppp->mru = PPP_MRU; 2733 init_ppp_file(&ppp->file, INTERFACE); 2734 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */ 2735 ppp->owner = file; 2736 for (i = 0; i < NUM_NP; ++i) 2737 ppp->npmode[i] = NPMODE_PASS; 2738 INIT_LIST_HEAD(&ppp->channels); 2739 spin_lock_init(&ppp->rlock); 2740 spin_lock_init(&ppp->wlock); 2741 #ifdef CONFIG_PPP_MULTILINK 2742 ppp->minseq = -1; 2743 skb_queue_head_init(&ppp->mrq); 2744 #endif /* CONFIG_PPP_MULTILINK */ 2745 #ifdef CONFIG_PPP_FILTER 2746 ppp->pass_filter = NULL; 2747 ppp->active_filter = NULL; 2748 #endif /* CONFIG_PPP_FILTER */ 2749 2750 /* 2751 * drum roll: don't forget to set 2752 * the net device is belong to 2753 */ 2754 dev_net_set(dev, net); 2755 2756 rtnl_lock(); 2757 mutex_lock(&pn->all_ppp_mutex); 2758 2759 if (unit < 0) { 2760 unit = unit_get(&pn->units_idr, ppp); 2761 if (unit < 0) { 2762 ret = unit; 2763 goto out2; 2764 } 2765 } else { 2766 ret = -EEXIST; 2767 if (unit_find(&pn->units_idr, unit)) 2768 goto out2; /* unit already exists */ 2769 /* 2770 * if caller need a specified unit number 2771 * lets try to satisfy him, otherwise -- 2772 * he should better ask us for new unit number 2773 * 2774 * NOTE: yes I know that returning EEXIST it's not 2775 * fair but at least pppd will ask us to allocate 2776 * new unit in this case so user is happy :) 2777 */ 2778 unit = unit_set(&pn->units_idr, ppp, unit); 2779 if (unit < 0) 2780 goto out2; 2781 } 2782 2783 /* Initialize the new ppp unit */ 2784 ppp->file.index = unit; 2785 sprintf(dev->name, "ppp%d", unit); 2786 2787 ret = register_netdevice(dev); 2788 if (ret != 0) { 2789 unit_put(&pn->units_idr, unit); 2790 netdev_err(ppp->dev, "PPP: couldn't register device %s (%d)\n", 2791 dev->name, ret); 2792 goto out2; 2793 } 2794 2795 ppp->ppp_net = net; 2796 2797 atomic_inc(&ppp_unit_count); 2798 mutex_unlock(&pn->all_ppp_mutex); 2799 rtnl_unlock(); 2800 2801 *retp = 0; 2802 return ppp; 2803 2804 out2: 2805 mutex_unlock(&pn->all_ppp_mutex); 2806 free_netdev(dev); 2807 out1: 2808 *retp = ret; 2809 return NULL; 2810 } 2811 2812 /* 2813 * Initialize a ppp_file structure. 2814 */ 2815 static void 2816 init_ppp_file(struct ppp_file *pf, int kind) 2817 { 2818 pf->kind = kind; 2819 skb_queue_head_init(&pf->xq); 2820 skb_queue_head_init(&pf->rq); 2821 atomic_set(&pf->refcnt, 1); 2822 init_waitqueue_head(&pf->rwait); 2823 } 2824 2825 /* 2826 * Free the memory used by a ppp unit. This is only called once 2827 * there are no channels connected to the unit and no file structs 2828 * that reference the unit. 2829 */ 2830 static void ppp_destroy_interface(struct ppp *ppp) 2831 { 2832 atomic_dec(&ppp_unit_count); 2833 2834 if (!ppp->file.dead || ppp->n_channels) { 2835 /* "can't happen" */ 2836 netdev_err(ppp->dev, "ppp: destroying ppp struct %p " 2837 "but dead=%d n_channels=%d !\n", 2838 ppp, ppp->file.dead, ppp->n_channels); 2839 return; 2840 } 2841 2842 ppp_ccp_closed(ppp); 2843 if (ppp->vj) { 2844 slhc_free(ppp->vj); 2845 ppp->vj = NULL; 2846 } 2847 skb_queue_purge(&ppp->file.xq); 2848 skb_queue_purge(&ppp->file.rq); 2849 #ifdef CONFIG_PPP_MULTILINK 2850 skb_queue_purge(&ppp->mrq); 2851 #endif /* CONFIG_PPP_MULTILINK */ 2852 #ifdef CONFIG_PPP_FILTER 2853 if (ppp->pass_filter) { 2854 bpf_prog_destroy(ppp->pass_filter); 2855 ppp->pass_filter = NULL; 2856 } 2857 2858 if (ppp->active_filter) { 2859 bpf_prog_destroy(ppp->active_filter); 2860 ppp->active_filter = NULL; 2861 } 2862 #endif /* CONFIG_PPP_FILTER */ 2863 2864 kfree_skb(ppp->xmit_pending); 2865 2866 free_netdev(ppp->dev); 2867 } 2868 2869 /* 2870 * Locate an existing ppp unit. 2871 * The caller should have locked the all_ppp_mutex. 2872 */ 2873 static struct ppp * 2874 ppp_find_unit(struct ppp_net *pn, int unit) 2875 { 2876 return unit_find(&pn->units_idr, unit); 2877 } 2878 2879 /* 2880 * Locate an existing ppp channel. 2881 * The caller should have locked the all_channels_lock. 2882 * First we look in the new_channels list, then in the 2883 * all_channels list. If found in the new_channels list, 2884 * we move it to the all_channels list. This is for speed 2885 * when we have a lot of channels in use. 2886 */ 2887 static struct channel * 2888 ppp_find_channel(struct ppp_net *pn, int unit) 2889 { 2890 struct channel *pch; 2891 2892 list_for_each_entry(pch, &pn->new_channels, list) { 2893 if (pch->file.index == unit) { 2894 list_move(&pch->list, &pn->all_channels); 2895 return pch; 2896 } 2897 } 2898 2899 list_for_each_entry(pch, &pn->all_channels, list) { 2900 if (pch->file.index == unit) 2901 return pch; 2902 } 2903 2904 return NULL; 2905 } 2906 2907 /* 2908 * Connect a PPP channel to a PPP interface unit. 2909 */ 2910 static int 2911 ppp_connect_channel(struct channel *pch, int unit) 2912 { 2913 struct ppp *ppp; 2914 struct ppp_net *pn; 2915 int ret = -ENXIO; 2916 int hdrlen; 2917 2918 pn = ppp_pernet(pch->chan_net); 2919 2920 mutex_lock(&pn->all_ppp_mutex); 2921 ppp = ppp_find_unit(pn, unit); 2922 if (!ppp) 2923 goto out; 2924 write_lock_bh(&pch->upl); 2925 ret = -EINVAL; 2926 if (pch->ppp) 2927 goto outl; 2928 2929 ppp_lock(ppp); 2930 if (pch->file.hdrlen > ppp->file.hdrlen) 2931 ppp->file.hdrlen = pch->file.hdrlen; 2932 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */ 2933 if (hdrlen > ppp->dev->hard_header_len) 2934 ppp->dev->hard_header_len = hdrlen; 2935 list_add_tail(&pch->clist, &ppp->channels); 2936 ++ppp->n_channels; 2937 pch->ppp = ppp; 2938 atomic_inc(&ppp->file.refcnt); 2939 ppp_unlock(ppp); 2940 ret = 0; 2941 2942 outl: 2943 write_unlock_bh(&pch->upl); 2944 out: 2945 mutex_unlock(&pn->all_ppp_mutex); 2946 return ret; 2947 } 2948 2949 /* 2950 * Disconnect a channel from its ppp unit. 2951 */ 2952 static int 2953 ppp_disconnect_channel(struct channel *pch) 2954 { 2955 struct ppp *ppp; 2956 int err = -EINVAL; 2957 2958 write_lock_bh(&pch->upl); 2959 ppp = pch->ppp; 2960 pch->ppp = NULL; 2961 write_unlock_bh(&pch->upl); 2962 if (ppp) { 2963 /* remove it from the ppp unit's list */ 2964 ppp_lock(ppp); 2965 list_del(&pch->clist); 2966 if (--ppp->n_channels == 0) 2967 wake_up_interruptible(&ppp->file.rwait); 2968 ppp_unlock(ppp); 2969 if (atomic_dec_and_test(&ppp->file.refcnt)) 2970 ppp_destroy_interface(ppp); 2971 err = 0; 2972 } 2973 return err; 2974 } 2975 2976 /* 2977 * Free up the resources used by a ppp channel. 2978 */ 2979 static void ppp_destroy_channel(struct channel *pch) 2980 { 2981 atomic_dec(&channel_count); 2982 2983 if (!pch->file.dead) { 2984 /* "can't happen" */ 2985 pr_err("ppp: destroying undead channel %p !\n", pch); 2986 return; 2987 } 2988 skb_queue_purge(&pch->file.xq); 2989 skb_queue_purge(&pch->file.rq); 2990 kfree(pch); 2991 } 2992 2993 static void __exit ppp_cleanup(void) 2994 { 2995 /* should never happen */ 2996 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count)) 2997 pr_err("PPP: removing module but units remain!\n"); 2998 unregister_chrdev(PPP_MAJOR, "ppp"); 2999 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0)); 3000 class_destroy(ppp_class); 3001 unregister_pernet_device(&ppp_net_ops); 3002 } 3003 3004 /* 3005 * Units handling. Caller must protect concurrent access 3006 * by holding all_ppp_mutex 3007 */ 3008 3009 /* associate pointer with specified number */ 3010 static int unit_set(struct idr *p, void *ptr, int n) 3011 { 3012 int unit; 3013 3014 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL); 3015 if (unit == -ENOSPC) 3016 unit = -EINVAL; 3017 return unit; 3018 } 3019 3020 /* get new free unit number and associate pointer with it */ 3021 static int unit_get(struct idr *p, void *ptr) 3022 { 3023 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL); 3024 } 3025 3026 /* put unit number back to a pool */ 3027 static void unit_put(struct idr *p, int n) 3028 { 3029 idr_remove(p, n); 3030 } 3031 3032 /* get pointer associated with the number */ 3033 static void *unit_find(struct idr *p, int n) 3034 { 3035 return idr_find(p, n); 3036 } 3037 3038 /* Module/initialization stuff */ 3039 3040 module_init(ppp_init); 3041 module_exit(ppp_cleanup); 3042 3043 EXPORT_SYMBOL(ppp_register_net_channel); 3044 EXPORT_SYMBOL(ppp_register_channel); 3045 EXPORT_SYMBOL(ppp_unregister_channel); 3046 EXPORT_SYMBOL(ppp_channel_index); 3047 EXPORT_SYMBOL(ppp_unit_number); 3048 EXPORT_SYMBOL(ppp_dev_name); 3049 EXPORT_SYMBOL(ppp_input); 3050 EXPORT_SYMBOL(ppp_input_error); 3051 EXPORT_SYMBOL(ppp_output_wakeup); 3052 EXPORT_SYMBOL(ppp_register_compressor); 3053 EXPORT_SYMBOL(ppp_unregister_compressor); 3054 MODULE_LICENSE("GPL"); 3055 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0); 3056 MODULE_ALIAS("devname:ppp"); 3057