1 /* 2 * Generic PPP layer for Linux. 3 * 4 * Copyright 1999-2002 Paul Mackerras. 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 * 11 * The generic PPP layer handles the PPP network interfaces, the 12 * /dev/ppp device, packet and VJ compression, and multilink. 13 * It talks to PPP `channels' via the interface defined in 14 * include/linux/ppp_channel.h. Channels provide the basic means for 15 * sending and receiving PPP frames on some kind of communications 16 * channel. 17 * 18 * Part of the code in this driver was inspired by the old async-only 19 * PPP driver, written by Michael Callahan and Al Longyear, and 20 * subsequently hacked by Paul Mackerras. 21 * 22 * ==FILEVERSION 20041108== 23 */ 24 25 #include <linux/module.h> 26 #include <linux/kernel.h> 27 #include <linux/kmod.h> 28 #include <linux/init.h> 29 #include <linux/list.h> 30 #include <linux/idr.h> 31 #include <linux/netdevice.h> 32 #include <linux/poll.h> 33 #include <linux/ppp_defs.h> 34 #include <linux/filter.h> 35 #include <linux/ppp-ioctl.h> 36 #include <linux/ppp_channel.h> 37 #include <linux/ppp-comp.h> 38 #include <linux/skbuff.h> 39 #include <linux/rtnetlink.h> 40 #include <linux/if_arp.h> 41 #include <linux/ip.h> 42 #include <linux/tcp.h> 43 #include <linux/spinlock.h> 44 #include <linux/rwsem.h> 45 #include <linux/stddef.h> 46 #include <linux/device.h> 47 #include <linux/mutex.h> 48 #include <linux/slab.h> 49 #include <asm/unaligned.h> 50 #include <net/slhc_vj.h> 51 #include <linux/atomic.h> 52 53 #include <linux/nsproxy.h> 54 #include <net/net_namespace.h> 55 #include <net/netns/generic.h> 56 57 #define PPP_VERSION "2.4.2" 58 59 /* 60 * Network protocols we support. 61 */ 62 #define NP_IP 0 /* Internet Protocol V4 */ 63 #define NP_IPV6 1 /* Internet Protocol V6 */ 64 #define NP_IPX 2 /* IPX protocol */ 65 #define NP_AT 3 /* Appletalk protocol */ 66 #define NP_MPLS_UC 4 /* MPLS unicast */ 67 #define NP_MPLS_MC 5 /* MPLS multicast */ 68 #define NUM_NP 6 /* Number of NPs. */ 69 70 #define MPHDRLEN 6 /* multilink protocol header length */ 71 #define MPHDRLEN_SSN 4 /* ditto with short sequence numbers */ 72 73 /* 74 * An instance of /dev/ppp can be associated with either a ppp 75 * interface unit or a ppp channel. In both cases, file->private_data 76 * points to one of these. 77 */ 78 struct ppp_file { 79 enum { 80 INTERFACE=1, CHANNEL 81 } kind; 82 struct sk_buff_head xq; /* pppd transmit queue */ 83 struct sk_buff_head rq; /* receive queue for pppd */ 84 wait_queue_head_t rwait; /* for poll on reading /dev/ppp */ 85 atomic_t refcnt; /* # refs (incl /dev/ppp attached) */ 86 int hdrlen; /* space to leave for headers */ 87 int index; /* interface unit / channel number */ 88 int dead; /* unit/channel has been shut down */ 89 }; 90 91 #define PF_TO_X(pf, X) container_of(pf, X, file) 92 93 #define PF_TO_PPP(pf) PF_TO_X(pf, struct ppp) 94 #define PF_TO_CHANNEL(pf) PF_TO_X(pf, struct channel) 95 96 /* 97 * Data structure to hold primary network stats for which 98 * we want to use 64 bit storage. Other network stats 99 * are stored in dev->stats of the ppp strucute. 100 */ 101 struct ppp_link_stats { 102 u64 rx_packets; 103 u64 tx_packets; 104 u64 rx_bytes; 105 u64 tx_bytes; 106 }; 107 108 /* 109 * Data structure describing one ppp unit. 110 * A ppp unit corresponds to a ppp network interface device 111 * and represents a multilink bundle. 112 * It can have 0 or more ppp channels connected to it. 113 */ 114 struct ppp { 115 struct ppp_file file; /* stuff for read/write/poll 0 */ 116 struct file *owner; /* file that owns this unit 48 */ 117 struct list_head channels; /* list of attached channels 4c */ 118 int n_channels; /* how many channels are attached 54 */ 119 spinlock_t rlock; /* lock for receive side 58 */ 120 spinlock_t wlock; /* lock for transmit side 5c */ 121 int mru; /* max receive unit 60 */ 122 unsigned int flags; /* control bits 64 */ 123 unsigned int xstate; /* transmit state bits 68 */ 124 unsigned int rstate; /* receive state bits 6c */ 125 int debug; /* debug flags 70 */ 126 struct slcompress *vj; /* state for VJ header compression */ 127 enum NPmode npmode[NUM_NP]; /* what to do with each net proto 78 */ 128 struct sk_buff *xmit_pending; /* a packet ready to go out 88 */ 129 struct compressor *xcomp; /* transmit packet compressor 8c */ 130 void *xc_state; /* its internal state 90 */ 131 struct compressor *rcomp; /* receive decompressor 94 */ 132 void *rc_state; /* its internal state 98 */ 133 unsigned long last_xmit; /* jiffies when last pkt sent 9c */ 134 unsigned long last_recv; /* jiffies when last pkt rcvd a0 */ 135 struct net_device *dev; /* network interface device a4 */ 136 int closing; /* is device closing down? a8 */ 137 #ifdef CONFIG_PPP_MULTILINK 138 int nxchan; /* next channel to send something on */ 139 u32 nxseq; /* next sequence number to send */ 140 int mrru; /* MP: max reconst. receive unit */ 141 u32 nextseq; /* MP: seq no of next packet */ 142 u32 minseq; /* MP: min of most recent seqnos */ 143 struct sk_buff_head mrq; /* MP: receive reconstruction queue */ 144 #endif /* CONFIG_PPP_MULTILINK */ 145 #ifdef CONFIG_PPP_FILTER 146 struct bpf_prog *pass_filter; /* filter for packets to pass */ 147 struct bpf_prog *active_filter; /* filter for pkts to reset idle */ 148 #endif /* CONFIG_PPP_FILTER */ 149 struct net *ppp_net; /* the net we belong to */ 150 struct ppp_link_stats stats64; /* 64 bit network stats */ 151 }; 152 153 /* 154 * Bits in flags: SC_NO_TCP_CCID, SC_CCP_OPEN, SC_CCP_UP, SC_LOOP_TRAFFIC, 155 * SC_MULTILINK, SC_MP_SHORTSEQ, SC_MP_XSHORTSEQ, SC_COMP_TCP, SC_REJ_COMP_TCP, 156 * SC_MUST_COMP 157 * Bits in rstate: SC_DECOMP_RUN, SC_DC_ERROR, SC_DC_FERROR. 158 * Bits in xstate: SC_COMP_RUN 159 */ 160 #define SC_FLAG_BITS (SC_NO_TCP_CCID|SC_CCP_OPEN|SC_CCP_UP|SC_LOOP_TRAFFIC \ 161 |SC_MULTILINK|SC_MP_SHORTSEQ|SC_MP_XSHORTSEQ \ 162 |SC_COMP_TCP|SC_REJ_COMP_TCP|SC_MUST_COMP) 163 164 /* 165 * Private data structure for each channel. 166 * This includes the data structure used for multilink. 167 */ 168 struct channel { 169 struct ppp_file file; /* stuff for read/write/poll */ 170 struct list_head list; /* link in all/new_channels list */ 171 struct ppp_channel *chan; /* public channel data structure */ 172 struct rw_semaphore chan_sem; /* protects `chan' during chan ioctl */ 173 spinlock_t downl; /* protects `chan', file.xq dequeue */ 174 struct ppp *ppp; /* ppp unit we're connected to */ 175 struct net *chan_net; /* the net channel belongs to */ 176 struct list_head clist; /* link in list of channels per unit */ 177 rwlock_t upl; /* protects `ppp' */ 178 #ifdef CONFIG_PPP_MULTILINK 179 u8 avail; /* flag used in multilink stuff */ 180 u8 had_frag; /* >= 1 fragments have been sent */ 181 u32 lastseq; /* MP: last sequence # received */ 182 int speed; /* speed of the corresponding ppp channel*/ 183 #endif /* CONFIG_PPP_MULTILINK */ 184 }; 185 186 /* 187 * SMP locking issues: 188 * Both the ppp.rlock and ppp.wlock locks protect the ppp.channels 189 * list and the ppp.n_channels field, you need to take both locks 190 * before you modify them. 191 * The lock ordering is: channel.upl -> ppp.wlock -> ppp.rlock -> 192 * channel.downl. 193 */ 194 195 static DEFINE_MUTEX(ppp_mutex); 196 static atomic_t ppp_unit_count = ATOMIC_INIT(0); 197 static atomic_t channel_count = ATOMIC_INIT(0); 198 199 /* per-net private data for this module */ 200 static int ppp_net_id __read_mostly; 201 struct ppp_net { 202 /* units to ppp mapping */ 203 struct idr units_idr; 204 205 /* 206 * all_ppp_mutex protects the units_idr mapping. 207 * It also ensures that finding a ppp unit in the units_idr 208 * map and updating its file.refcnt field is atomic. 209 */ 210 struct mutex all_ppp_mutex; 211 212 /* channels */ 213 struct list_head all_channels; 214 struct list_head new_channels; 215 int last_channel_index; 216 217 /* 218 * all_channels_lock protects all_channels and 219 * last_channel_index, and the atomicity of find 220 * a channel and updating its file.refcnt field. 221 */ 222 spinlock_t all_channels_lock; 223 }; 224 225 /* Get the PPP protocol number from a skb */ 226 #define PPP_PROTO(skb) get_unaligned_be16((skb)->data) 227 228 /* We limit the length of ppp->file.rq to this (arbitrary) value */ 229 #define PPP_MAX_RQLEN 32 230 231 /* 232 * Maximum number of multilink fragments queued up. 233 * This has to be large enough to cope with the maximum latency of 234 * the slowest channel relative to the others. Strictly it should 235 * depend on the number of channels and their characteristics. 236 */ 237 #define PPP_MP_MAX_QLEN 128 238 239 /* Multilink header bits. */ 240 #define B 0x80 /* this fragment begins a packet */ 241 #define E 0x40 /* this fragment ends a packet */ 242 243 /* Compare multilink sequence numbers (assumed to be 32 bits wide) */ 244 #define seq_before(a, b) ((s32)((a) - (b)) < 0) 245 #define seq_after(a, b) ((s32)((a) - (b)) > 0) 246 247 /* Prototypes. */ 248 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 249 struct file *file, unsigned int cmd, unsigned long arg); 250 static void ppp_xmit_process(struct ppp *ppp); 251 static void ppp_send_frame(struct ppp *ppp, struct sk_buff *skb); 252 static void ppp_push(struct ppp *ppp); 253 static void ppp_channel_push(struct channel *pch); 254 static void ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, 255 struct channel *pch); 256 static void ppp_receive_error(struct ppp *ppp); 257 static void ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb); 258 static struct sk_buff *ppp_decompress_frame(struct ppp *ppp, 259 struct sk_buff *skb); 260 #ifdef CONFIG_PPP_MULTILINK 261 static void ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, 262 struct channel *pch); 263 static void ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb); 264 static struct sk_buff *ppp_mp_reconstruct(struct ppp *ppp); 265 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb); 266 #endif /* CONFIG_PPP_MULTILINK */ 267 static int ppp_set_compress(struct ppp *ppp, unsigned long arg); 268 static void ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound); 269 static void ppp_ccp_closed(struct ppp *ppp); 270 static struct compressor *find_compressor(int type); 271 static void ppp_get_stats(struct ppp *ppp, struct ppp_stats *st); 272 static struct ppp *ppp_create_interface(struct net *net, int unit, 273 struct file *file, int *retp); 274 static void init_ppp_file(struct ppp_file *pf, int kind); 275 static void ppp_destroy_interface(struct ppp *ppp); 276 static struct ppp *ppp_find_unit(struct ppp_net *pn, int unit); 277 static struct channel *ppp_find_channel(struct ppp_net *pn, int unit); 278 static int ppp_connect_channel(struct channel *pch, int unit); 279 static int ppp_disconnect_channel(struct channel *pch); 280 static void ppp_destroy_channel(struct channel *pch); 281 static int unit_get(struct idr *p, void *ptr); 282 static int unit_set(struct idr *p, void *ptr, int n); 283 static void unit_put(struct idr *p, int n); 284 static void *unit_find(struct idr *p, int n); 285 286 static const struct net_device_ops ppp_netdev_ops; 287 288 static struct class *ppp_class; 289 290 /* per net-namespace data */ 291 static inline struct ppp_net *ppp_pernet(struct net *net) 292 { 293 BUG_ON(!net); 294 295 return net_generic(net, ppp_net_id); 296 } 297 298 /* Translates a PPP protocol number to a NP index (NP == network protocol) */ 299 static inline int proto_to_npindex(int proto) 300 { 301 switch (proto) { 302 case PPP_IP: 303 return NP_IP; 304 case PPP_IPV6: 305 return NP_IPV6; 306 case PPP_IPX: 307 return NP_IPX; 308 case PPP_AT: 309 return NP_AT; 310 case PPP_MPLS_UC: 311 return NP_MPLS_UC; 312 case PPP_MPLS_MC: 313 return NP_MPLS_MC; 314 } 315 return -EINVAL; 316 } 317 318 /* Translates an NP index into a PPP protocol number */ 319 static const int npindex_to_proto[NUM_NP] = { 320 PPP_IP, 321 PPP_IPV6, 322 PPP_IPX, 323 PPP_AT, 324 PPP_MPLS_UC, 325 PPP_MPLS_MC, 326 }; 327 328 /* Translates an ethertype into an NP index */ 329 static inline int ethertype_to_npindex(int ethertype) 330 { 331 switch (ethertype) { 332 case ETH_P_IP: 333 return NP_IP; 334 case ETH_P_IPV6: 335 return NP_IPV6; 336 case ETH_P_IPX: 337 return NP_IPX; 338 case ETH_P_PPPTALK: 339 case ETH_P_ATALK: 340 return NP_AT; 341 case ETH_P_MPLS_UC: 342 return NP_MPLS_UC; 343 case ETH_P_MPLS_MC: 344 return NP_MPLS_MC; 345 } 346 return -1; 347 } 348 349 /* Translates an NP index into an ethertype */ 350 static const int npindex_to_ethertype[NUM_NP] = { 351 ETH_P_IP, 352 ETH_P_IPV6, 353 ETH_P_IPX, 354 ETH_P_PPPTALK, 355 ETH_P_MPLS_UC, 356 ETH_P_MPLS_MC, 357 }; 358 359 /* 360 * Locking shorthand. 361 */ 362 #define ppp_xmit_lock(ppp) spin_lock_bh(&(ppp)->wlock) 363 #define ppp_xmit_unlock(ppp) spin_unlock_bh(&(ppp)->wlock) 364 #define ppp_recv_lock(ppp) spin_lock_bh(&(ppp)->rlock) 365 #define ppp_recv_unlock(ppp) spin_unlock_bh(&(ppp)->rlock) 366 #define ppp_lock(ppp) do { ppp_xmit_lock(ppp); \ 367 ppp_recv_lock(ppp); } while (0) 368 #define ppp_unlock(ppp) do { ppp_recv_unlock(ppp); \ 369 ppp_xmit_unlock(ppp); } while (0) 370 371 /* 372 * /dev/ppp device routines. 373 * The /dev/ppp device is used by pppd to control the ppp unit. 374 * It supports the read, write, ioctl and poll functions. 375 * Open instances of /dev/ppp can be in one of three states: 376 * unattached, attached to a ppp unit, or attached to a ppp channel. 377 */ 378 static int ppp_open(struct inode *inode, struct file *file) 379 { 380 /* 381 * This could (should?) be enforced by the permissions on /dev/ppp. 382 */ 383 if (!capable(CAP_NET_ADMIN)) 384 return -EPERM; 385 return 0; 386 } 387 388 static int ppp_release(struct inode *unused, struct file *file) 389 { 390 struct ppp_file *pf = file->private_data; 391 struct ppp *ppp; 392 393 if (pf) { 394 file->private_data = NULL; 395 if (pf->kind == INTERFACE) { 396 ppp = PF_TO_PPP(pf); 397 rtnl_lock(); 398 if (file == ppp->owner) 399 unregister_netdevice(ppp->dev); 400 rtnl_unlock(); 401 } 402 if (atomic_dec_and_test(&pf->refcnt)) { 403 switch (pf->kind) { 404 case INTERFACE: 405 ppp_destroy_interface(PF_TO_PPP(pf)); 406 break; 407 case CHANNEL: 408 ppp_destroy_channel(PF_TO_CHANNEL(pf)); 409 break; 410 } 411 } 412 } 413 return 0; 414 } 415 416 static ssize_t ppp_read(struct file *file, char __user *buf, 417 size_t count, loff_t *ppos) 418 { 419 struct ppp_file *pf = file->private_data; 420 DECLARE_WAITQUEUE(wait, current); 421 ssize_t ret; 422 struct sk_buff *skb = NULL; 423 struct iovec iov; 424 struct iov_iter to; 425 426 ret = count; 427 428 if (!pf) 429 return -ENXIO; 430 add_wait_queue(&pf->rwait, &wait); 431 for (;;) { 432 set_current_state(TASK_INTERRUPTIBLE); 433 skb = skb_dequeue(&pf->rq); 434 if (skb) 435 break; 436 ret = 0; 437 if (pf->dead) 438 break; 439 if (pf->kind == INTERFACE) { 440 /* 441 * Return 0 (EOF) on an interface that has no 442 * channels connected, unless it is looping 443 * network traffic (demand mode). 444 */ 445 struct ppp *ppp = PF_TO_PPP(pf); 446 447 ppp_recv_lock(ppp); 448 if (ppp->n_channels == 0 && 449 (ppp->flags & SC_LOOP_TRAFFIC) == 0) { 450 ppp_recv_unlock(ppp); 451 break; 452 } 453 ppp_recv_unlock(ppp); 454 } 455 ret = -EAGAIN; 456 if (file->f_flags & O_NONBLOCK) 457 break; 458 ret = -ERESTARTSYS; 459 if (signal_pending(current)) 460 break; 461 schedule(); 462 } 463 set_current_state(TASK_RUNNING); 464 remove_wait_queue(&pf->rwait, &wait); 465 466 if (!skb) 467 goto out; 468 469 ret = -EOVERFLOW; 470 if (skb->len > count) 471 goto outf; 472 ret = -EFAULT; 473 iov.iov_base = buf; 474 iov.iov_len = count; 475 iov_iter_init(&to, READ, &iov, 1, count); 476 if (skb_copy_datagram_iter(skb, 0, &to, skb->len)) 477 goto outf; 478 ret = skb->len; 479 480 outf: 481 kfree_skb(skb); 482 out: 483 return ret; 484 } 485 486 static ssize_t ppp_write(struct file *file, const char __user *buf, 487 size_t count, loff_t *ppos) 488 { 489 struct ppp_file *pf = file->private_data; 490 struct sk_buff *skb; 491 ssize_t ret; 492 493 if (!pf) 494 return -ENXIO; 495 ret = -ENOMEM; 496 skb = alloc_skb(count + pf->hdrlen, GFP_KERNEL); 497 if (!skb) 498 goto out; 499 skb_reserve(skb, pf->hdrlen); 500 ret = -EFAULT; 501 if (copy_from_user(skb_put(skb, count), buf, count)) { 502 kfree_skb(skb); 503 goto out; 504 } 505 506 skb_queue_tail(&pf->xq, skb); 507 508 switch (pf->kind) { 509 case INTERFACE: 510 ppp_xmit_process(PF_TO_PPP(pf)); 511 break; 512 case CHANNEL: 513 ppp_channel_push(PF_TO_CHANNEL(pf)); 514 break; 515 } 516 517 ret = count; 518 519 out: 520 return ret; 521 } 522 523 /* No kernel lock - fine */ 524 static unsigned int ppp_poll(struct file *file, poll_table *wait) 525 { 526 struct ppp_file *pf = file->private_data; 527 unsigned int mask; 528 529 if (!pf) 530 return 0; 531 poll_wait(file, &pf->rwait, wait); 532 mask = POLLOUT | POLLWRNORM; 533 if (skb_peek(&pf->rq)) 534 mask |= POLLIN | POLLRDNORM; 535 if (pf->dead) 536 mask |= POLLHUP; 537 else if (pf->kind == INTERFACE) { 538 /* see comment in ppp_read */ 539 struct ppp *ppp = PF_TO_PPP(pf); 540 541 ppp_recv_lock(ppp); 542 if (ppp->n_channels == 0 && 543 (ppp->flags & SC_LOOP_TRAFFIC) == 0) 544 mask |= POLLIN | POLLRDNORM; 545 ppp_recv_unlock(ppp); 546 } 547 548 return mask; 549 } 550 551 #ifdef CONFIG_PPP_FILTER 552 static int get_filter(void __user *arg, struct sock_filter **p) 553 { 554 struct sock_fprog uprog; 555 struct sock_filter *code = NULL; 556 int len; 557 558 if (copy_from_user(&uprog, arg, sizeof(uprog))) 559 return -EFAULT; 560 561 if (!uprog.len) { 562 *p = NULL; 563 return 0; 564 } 565 566 len = uprog.len * sizeof(struct sock_filter); 567 code = memdup_user(uprog.filter, len); 568 if (IS_ERR(code)) 569 return PTR_ERR(code); 570 571 *p = code; 572 return uprog.len; 573 } 574 #endif /* CONFIG_PPP_FILTER */ 575 576 static long ppp_ioctl(struct file *file, unsigned int cmd, unsigned long arg) 577 { 578 struct ppp_file *pf = file->private_data; 579 struct ppp *ppp; 580 int err = -EFAULT, val, val2, i; 581 struct ppp_idle idle; 582 struct npioctl npi; 583 int unit, cflags; 584 struct slcompress *vj; 585 void __user *argp = (void __user *)arg; 586 int __user *p = argp; 587 588 if (!pf) 589 return ppp_unattached_ioctl(current->nsproxy->net_ns, 590 pf, file, cmd, arg); 591 592 if (cmd == PPPIOCDETACH) { 593 /* 594 * We have to be careful here... if the file descriptor 595 * has been dup'd, we could have another process in the 596 * middle of a poll using the same file *, so we had 597 * better not free the interface data structures - 598 * instead we fail the ioctl. Even in this case, we 599 * shut down the interface if we are the owner of it. 600 * Actually, we should get rid of PPPIOCDETACH, userland 601 * (i.e. pppd) could achieve the same effect by closing 602 * this fd and reopening /dev/ppp. 603 */ 604 err = -EINVAL; 605 mutex_lock(&ppp_mutex); 606 if (pf->kind == INTERFACE) { 607 ppp = PF_TO_PPP(pf); 608 rtnl_lock(); 609 if (file == ppp->owner) 610 unregister_netdevice(ppp->dev); 611 rtnl_unlock(); 612 } 613 if (atomic_long_read(&file->f_count) < 2) { 614 ppp_release(NULL, file); 615 err = 0; 616 } else 617 pr_warn("PPPIOCDETACH file->f_count=%ld\n", 618 atomic_long_read(&file->f_count)); 619 mutex_unlock(&ppp_mutex); 620 return err; 621 } 622 623 if (pf->kind == CHANNEL) { 624 struct channel *pch; 625 struct ppp_channel *chan; 626 627 mutex_lock(&ppp_mutex); 628 pch = PF_TO_CHANNEL(pf); 629 630 switch (cmd) { 631 case PPPIOCCONNECT: 632 if (get_user(unit, p)) 633 break; 634 err = ppp_connect_channel(pch, unit); 635 break; 636 637 case PPPIOCDISCONN: 638 err = ppp_disconnect_channel(pch); 639 break; 640 641 default: 642 down_read(&pch->chan_sem); 643 chan = pch->chan; 644 err = -ENOTTY; 645 if (chan && chan->ops->ioctl) 646 err = chan->ops->ioctl(chan, cmd, arg); 647 up_read(&pch->chan_sem); 648 } 649 mutex_unlock(&ppp_mutex); 650 return err; 651 } 652 653 if (pf->kind != INTERFACE) { 654 /* can't happen */ 655 pr_err("PPP: not interface or channel??\n"); 656 return -EINVAL; 657 } 658 659 mutex_lock(&ppp_mutex); 660 ppp = PF_TO_PPP(pf); 661 switch (cmd) { 662 case PPPIOCSMRU: 663 if (get_user(val, p)) 664 break; 665 ppp->mru = val; 666 err = 0; 667 break; 668 669 case PPPIOCSFLAGS: 670 if (get_user(val, p)) 671 break; 672 ppp_lock(ppp); 673 cflags = ppp->flags & ~val; 674 #ifdef CONFIG_PPP_MULTILINK 675 if (!(ppp->flags & SC_MULTILINK) && (val & SC_MULTILINK)) 676 ppp->nextseq = 0; 677 #endif 678 ppp->flags = val & SC_FLAG_BITS; 679 ppp_unlock(ppp); 680 if (cflags & SC_CCP_OPEN) 681 ppp_ccp_closed(ppp); 682 err = 0; 683 break; 684 685 case PPPIOCGFLAGS: 686 val = ppp->flags | ppp->xstate | ppp->rstate; 687 if (put_user(val, p)) 688 break; 689 err = 0; 690 break; 691 692 case PPPIOCSCOMPRESS: 693 err = ppp_set_compress(ppp, arg); 694 break; 695 696 case PPPIOCGUNIT: 697 if (put_user(ppp->file.index, p)) 698 break; 699 err = 0; 700 break; 701 702 case PPPIOCSDEBUG: 703 if (get_user(val, p)) 704 break; 705 ppp->debug = val; 706 err = 0; 707 break; 708 709 case PPPIOCGDEBUG: 710 if (put_user(ppp->debug, p)) 711 break; 712 err = 0; 713 break; 714 715 case PPPIOCGIDLE: 716 idle.xmit_idle = (jiffies - ppp->last_xmit) / HZ; 717 idle.recv_idle = (jiffies - ppp->last_recv) / HZ; 718 if (copy_to_user(argp, &idle, sizeof(idle))) 719 break; 720 err = 0; 721 break; 722 723 case PPPIOCSMAXCID: 724 if (get_user(val, p)) 725 break; 726 val2 = 15; 727 if ((val >> 16) != 0) { 728 val2 = val >> 16; 729 val &= 0xffff; 730 } 731 vj = slhc_init(val2+1, val+1); 732 if (IS_ERR(vj)) { 733 err = PTR_ERR(vj); 734 break; 735 } 736 ppp_lock(ppp); 737 if (ppp->vj) 738 slhc_free(ppp->vj); 739 ppp->vj = vj; 740 ppp_unlock(ppp); 741 err = 0; 742 break; 743 744 case PPPIOCGNPMODE: 745 case PPPIOCSNPMODE: 746 if (copy_from_user(&npi, argp, sizeof(npi))) 747 break; 748 err = proto_to_npindex(npi.protocol); 749 if (err < 0) 750 break; 751 i = err; 752 if (cmd == PPPIOCGNPMODE) { 753 err = -EFAULT; 754 npi.mode = ppp->npmode[i]; 755 if (copy_to_user(argp, &npi, sizeof(npi))) 756 break; 757 } else { 758 ppp->npmode[i] = npi.mode; 759 /* we may be able to transmit more packets now (??) */ 760 netif_wake_queue(ppp->dev); 761 } 762 err = 0; 763 break; 764 765 #ifdef CONFIG_PPP_FILTER 766 case PPPIOCSPASS: 767 { 768 struct sock_filter *code; 769 770 err = get_filter(argp, &code); 771 if (err >= 0) { 772 struct bpf_prog *pass_filter = NULL; 773 struct sock_fprog_kern fprog = { 774 .len = err, 775 .filter = code, 776 }; 777 778 err = 0; 779 if (fprog.filter) 780 err = bpf_prog_create(&pass_filter, &fprog); 781 if (!err) { 782 ppp_lock(ppp); 783 if (ppp->pass_filter) 784 bpf_prog_destroy(ppp->pass_filter); 785 ppp->pass_filter = pass_filter; 786 ppp_unlock(ppp); 787 } 788 kfree(code); 789 } 790 break; 791 } 792 case PPPIOCSACTIVE: 793 { 794 struct sock_filter *code; 795 796 err = get_filter(argp, &code); 797 if (err >= 0) { 798 struct bpf_prog *active_filter = NULL; 799 struct sock_fprog_kern fprog = { 800 .len = err, 801 .filter = code, 802 }; 803 804 err = 0; 805 if (fprog.filter) 806 err = bpf_prog_create(&active_filter, &fprog); 807 if (!err) { 808 ppp_lock(ppp); 809 if (ppp->active_filter) 810 bpf_prog_destroy(ppp->active_filter); 811 ppp->active_filter = active_filter; 812 ppp_unlock(ppp); 813 } 814 kfree(code); 815 } 816 break; 817 } 818 #endif /* CONFIG_PPP_FILTER */ 819 820 #ifdef CONFIG_PPP_MULTILINK 821 case PPPIOCSMRRU: 822 if (get_user(val, p)) 823 break; 824 ppp_recv_lock(ppp); 825 ppp->mrru = val; 826 ppp_recv_unlock(ppp); 827 err = 0; 828 break; 829 #endif /* CONFIG_PPP_MULTILINK */ 830 831 default: 832 err = -ENOTTY; 833 } 834 mutex_unlock(&ppp_mutex); 835 return err; 836 } 837 838 static int ppp_unattached_ioctl(struct net *net, struct ppp_file *pf, 839 struct file *file, unsigned int cmd, unsigned long arg) 840 { 841 int unit, err = -EFAULT; 842 struct ppp *ppp; 843 struct channel *chan; 844 struct ppp_net *pn; 845 int __user *p = (int __user *)arg; 846 847 mutex_lock(&ppp_mutex); 848 switch (cmd) { 849 case PPPIOCNEWUNIT: 850 /* Create a new ppp unit */ 851 if (get_user(unit, p)) 852 break; 853 ppp = ppp_create_interface(net, unit, file, &err); 854 if (!ppp) 855 break; 856 file->private_data = &ppp->file; 857 err = -EFAULT; 858 if (put_user(ppp->file.index, p)) 859 break; 860 err = 0; 861 break; 862 863 case PPPIOCATTACH: 864 /* Attach to an existing ppp unit */ 865 if (get_user(unit, p)) 866 break; 867 err = -ENXIO; 868 pn = ppp_pernet(net); 869 mutex_lock(&pn->all_ppp_mutex); 870 ppp = ppp_find_unit(pn, unit); 871 if (ppp) { 872 atomic_inc(&ppp->file.refcnt); 873 file->private_data = &ppp->file; 874 err = 0; 875 } 876 mutex_unlock(&pn->all_ppp_mutex); 877 break; 878 879 case PPPIOCATTCHAN: 880 if (get_user(unit, p)) 881 break; 882 err = -ENXIO; 883 pn = ppp_pernet(net); 884 spin_lock_bh(&pn->all_channels_lock); 885 chan = ppp_find_channel(pn, unit); 886 if (chan) { 887 atomic_inc(&chan->file.refcnt); 888 file->private_data = &chan->file; 889 err = 0; 890 } 891 spin_unlock_bh(&pn->all_channels_lock); 892 break; 893 894 default: 895 err = -ENOTTY; 896 } 897 mutex_unlock(&ppp_mutex); 898 return err; 899 } 900 901 static const struct file_operations ppp_device_fops = { 902 .owner = THIS_MODULE, 903 .read = ppp_read, 904 .write = ppp_write, 905 .poll = ppp_poll, 906 .unlocked_ioctl = ppp_ioctl, 907 .open = ppp_open, 908 .release = ppp_release, 909 .llseek = noop_llseek, 910 }; 911 912 static __net_init int ppp_init_net(struct net *net) 913 { 914 struct ppp_net *pn = net_generic(net, ppp_net_id); 915 916 idr_init(&pn->units_idr); 917 mutex_init(&pn->all_ppp_mutex); 918 919 INIT_LIST_HEAD(&pn->all_channels); 920 INIT_LIST_HEAD(&pn->new_channels); 921 922 spin_lock_init(&pn->all_channels_lock); 923 924 return 0; 925 } 926 927 static __net_exit void ppp_exit_net(struct net *net) 928 { 929 struct ppp_net *pn = net_generic(net, ppp_net_id); 930 struct net_device *dev; 931 struct net_device *aux; 932 struct ppp *ppp; 933 LIST_HEAD(list); 934 int id; 935 936 rtnl_lock(); 937 for_each_netdev_safe(net, dev, aux) { 938 if (dev->netdev_ops == &ppp_netdev_ops) 939 unregister_netdevice_queue(dev, &list); 940 } 941 942 idr_for_each_entry(&pn->units_idr, ppp, id) 943 /* Skip devices already unregistered by previous loop */ 944 if (!net_eq(dev_net(ppp->dev), net)) 945 unregister_netdevice_queue(ppp->dev, &list); 946 947 unregister_netdevice_many(&list); 948 rtnl_unlock(); 949 950 idr_destroy(&pn->units_idr); 951 } 952 953 static struct pernet_operations ppp_net_ops = { 954 .init = ppp_init_net, 955 .exit = ppp_exit_net, 956 .id = &ppp_net_id, 957 .size = sizeof(struct ppp_net), 958 }; 959 960 #define PPP_MAJOR 108 961 962 /* Called at boot time if ppp is compiled into the kernel, 963 or at module load time (from init_module) if compiled as a module. */ 964 static int __init ppp_init(void) 965 { 966 int err; 967 968 pr_info("PPP generic driver version " PPP_VERSION "\n"); 969 970 err = register_pernet_device(&ppp_net_ops); 971 if (err) { 972 pr_err("failed to register PPP pernet device (%d)\n", err); 973 goto out; 974 } 975 976 err = register_chrdev(PPP_MAJOR, "ppp", &ppp_device_fops); 977 if (err) { 978 pr_err("failed to register PPP device (%d)\n", err); 979 goto out_net; 980 } 981 982 ppp_class = class_create(THIS_MODULE, "ppp"); 983 if (IS_ERR(ppp_class)) { 984 err = PTR_ERR(ppp_class); 985 goto out_chrdev; 986 } 987 988 /* not a big deal if we fail here :-) */ 989 device_create(ppp_class, NULL, MKDEV(PPP_MAJOR, 0), NULL, "ppp"); 990 991 return 0; 992 993 out_chrdev: 994 unregister_chrdev(PPP_MAJOR, "ppp"); 995 out_net: 996 unregister_pernet_device(&ppp_net_ops); 997 out: 998 return err; 999 } 1000 1001 /* 1002 * Network interface unit routines. 1003 */ 1004 static netdev_tx_t 1005 ppp_start_xmit(struct sk_buff *skb, struct net_device *dev) 1006 { 1007 struct ppp *ppp = netdev_priv(dev); 1008 int npi, proto; 1009 unsigned char *pp; 1010 1011 npi = ethertype_to_npindex(ntohs(skb->protocol)); 1012 if (npi < 0) 1013 goto outf; 1014 1015 /* Drop, accept or reject the packet */ 1016 switch (ppp->npmode[npi]) { 1017 case NPMODE_PASS: 1018 break; 1019 case NPMODE_QUEUE: 1020 /* it would be nice to have a way to tell the network 1021 system to queue this one up for later. */ 1022 goto outf; 1023 case NPMODE_DROP: 1024 case NPMODE_ERROR: 1025 goto outf; 1026 } 1027 1028 /* Put the 2-byte PPP protocol number on the front, 1029 making sure there is room for the address and control fields. */ 1030 if (skb_cow_head(skb, PPP_HDRLEN)) 1031 goto outf; 1032 1033 pp = skb_push(skb, 2); 1034 proto = npindex_to_proto[npi]; 1035 put_unaligned_be16(proto, pp); 1036 1037 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, dev_net(dev))); 1038 skb_queue_tail(&ppp->file.xq, skb); 1039 ppp_xmit_process(ppp); 1040 return NETDEV_TX_OK; 1041 1042 outf: 1043 kfree_skb(skb); 1044 ++dev->stats.tx_dropped; 1045 return NETDEV_TX_OK; 1046 } 1047 1048 static int 1049 ppp_net_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) 1050 { 1051 struct ppp *ppp = netdev_priv(dev); 1052 int err = -EFAULT; 1053 void __user *addr = (void __user *) ifr->ifr_ifru.ifru_data; 1054 struct ppp_stats stats; 1055 struct ppp_comp_stats cstats; 1056 char *vers; 1057 1058 switch (cmd) { 1059 case SIOCGPPPSTATS: 1060 ppp_get_stats(ppp, &stats); 1061 if (copy_to_user(addr, &stats, sizeof(stats))) 1062 break; 1063 err = 0; 1064 break; 1065 1066 case SIOCGPPPCSTATS: 1067 memset(&cstats, 0, sizeof(cstats)); 1068 if (ppp->xc_state) 1069 ppp->xcomp->comp_stat(ppp->xc_state, &cstats.c); 1070 if (ppp->rc_state) 1071 ppp->rcomp->decomp_stat(ppp->rc_state, &cstats.d); 1072 if (copy_to_user(addr, &cstats, sizeof(cstats))) 1073 break; 1074 err = 0; 1075 break; 1076 1077 case SIOCGPPPVER: 1078 vers = PPP_VERSION; 1079 if (copy_to_user(addr, vers, strlen(vers) + 1)) 1080 break; 1081 err = 0; 1082 break; 1083 1084 default: 1085 err = -EINVAL; 1086 } 1087 1088 return err; 1089 } 1090 1091 static struct rtnl_link_stats64* 1092 ppp_get_stats64(struct net_device *dev, struct rtnl_link_stats64 *stats64) 1093 { 1094 struct ppp *ppp = netdev_priv(dev); 1095 1096 ppp_recv_lock(ppp); 1097 stats64->rx_packets = ppp->stats64.rx_packets; 1098 stats64->rx_bytes = ppp->stats64.rx_bytes; 1099 ppp_recv_unlock(ppp); 1100 1101 ppp_xmit_lock(ppp); 1102 stats64->tx_packets = ppp->stats64.tx_packets; 1103 stats64->tx_bytes = ppp->stats64.tx_bytes; 1104 ppp_xmit_unlock(ppp); 1105 1106 stats64->rx_errors = dev->stats.rx_errors; 1107 stats64->tx_errors = dev->stats.tx_errors; 1108 stats64->rx_dropped = dev->stats.rx_dropped; 1109 stats64->tx_dropped = dev->stats.tx_dropped; 1110 stats64->rx_length_errors = dev->stats.rx_length_errors; 1111 1112 return stats64; 1113 } 1114 1115 static struct lock_class_key ppp_tx_busylock; 1116 static int ppp_dev_init(struct net_device *dev) 1117 { 1118 dev->qdisc_tx_busylock = &ppp_tx_busylock; 1119 return 0; 1120 } 1121 1122 static void ppp_dev_uninit(struct net_device *dev) 1123 { 1124 struct ppp *ppp = netdev_priv(dev); 1125 struct ppp_net *pn = ppp_pernet(ppp->ppp_net); 1126 1127 ppp_lock(ppp); 1128 ppp->closing = 1; 1129 ppp_unlock(ppp); 1130 1131 mutex_lock(&pn->all_ppp_mutex); 1132 unit_put(&pn->units_idr, ppp->file.index); 1133 mutex_unlock(&pn->all_ppp_mutex); 1134 1135 ppp->owner = NULL; 1136 1137 ppp->file.dead = 1; 1138 wake_up_interruptible(&ppp->file.rwait); 1139 } 1140 1141 static const struct net_device_ops ppp_netdev_ops = { 1142 .ndo_init = ppp_dev_init, 1143 .ndo_uninit = ppp_dev_uninit, 1144 .ndo_start_xmit = ppp_start_xmit, 1145 .ndo_do_ioctl = ppp_net_ioctl, 1146 .ndo_get_stats64 = ppp_get_stats64, 1147 }; 1148 1149 static struct device_type ppp_type = { 1150 .name = "ppp", 1151 }; 1152 1153 static void ppp_setup(struct net_device *dev) 1154 { 1155 dev->netdev_ops = &ppp_netdev_ops; 1156 SET_NETDEV_DEVTYPE(dev, &ppp_type); 1157 1158 dev->hard_header_len = PPP_HDRLEN; 1159 dev->mtu = PPP_MRU; 1160 dev->addr_len = 0; 1161 dev->tx_queue_len = 3; 1162 dev->type = ARPHRD_PPP; 1163 dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST; 1164 netif_keep_dst(dev); 1165 } 1166 1167 /* 1168 * Transmit-side routines. 1169 */ 1170 1171 /* 1172 * Called to do any work queued up on the transmit side 1173 * that can now be done. 1174 */ 1175 static void 1176 ppp_xmit_process(struct ppp *ppp) 1177 { 1178 struct sk_buff *skb; 1179 1180 ppp_xmit_lock(ppp); 1181 if (!ppp->closing) { 1182 ppp_push(ppp); 1183 while (!ppp->xmit_pending && 1184 (skb = skb_dequeue(&ppp->file.xq))) 1185 ppp_send_frame(ppp, skb); 1186 /* If there's no work left to do, tell the core net 1187 code that we can accept some more. */ 1188 if (!ppp->xmit_pending && !skb_peek(&ppp->file.xq)) 1189 netif_wake_queue(ppp->dev); 1190 else 1191 netif_stop_queue(ppp->dev); 1192 } 1193 ppp_xmit_unlock(ppp); 1194 } 1195 1196 static inline struct sk_buff * 1197 pad_compress_skb(struct ppp *ppp, struct sk_buff *skb) 1198 { 1199 struct sk_buff *new_skb; 1200 int len; 1201 int new_skb_size = ppp->dev->mtu + 1202 ppp->xcomp->comp_extra + ppp->dev->hard_header_len; 1203 int compressor_skb_size = ppp->dev->mtu + 1204 ppp->xcomp->comp_extra + PPP_HDRLEN; 1205 new_skb = alloc_skb(new_skb_size, GFP_ATOMIC); 1206 if (!new_skb) { 1207 if (net_ratelimit()) 1208 netdev_err(ppp->dev, "PPP: no memory (comp pkt)\n"); 1209 return NULL; 1210 } 1211 if (ppp->dev->hard_header_len > PPP_HDRLEN) 1212 skb_reserve(new_skb, 1213 ppp->dev->hard_header_len - PPP_HDRLEN); 1214 1215 /* compressor still expects A/C bytes in hdr */ 1216 len = ppp->xcomp->compress(ppp->xc_state, skb->data - 2, 1217 new_skb->data, skb->len + 2, 1218 compressor_skb_size); 1219 if (len > 0 && (ppp->flags & SC_CCP_UP)) { 1220 consume_skb(skb); 1221 skb = new_skb; 1222 skb_put(skb, len); 1223 skb_pull(skb, 2); /* pull off A/C bytes */ 1224 } else if (len == 0) { 1225 /* didn't compress, or CCP not up yet */ 1226 consume_skb(new_skb); 1227 new_skb = skb; 1228 } else { 1229 /* 1230 * (len < 0) 1231 * MPPE requires that we do not send unencrypted 1232 * frames. The compressor will return -1 if we 1233 * should drop the frame. We cannot simply test 1234 * the compress_proto because MPPE and MPPC share 1235 * the same number. 1236 */ 1237 if (net_ratelimit()) 1238 netdev_err(ppp->dev, "ppp: compressor dropped pkt\n"); 1239 kfree_skb(skb); 1240 consume_skb(new_skb); 1241 new_skb = NULL; 1242 } 1243 return new_skb; 1244 } 1245 1246 /* 1247 * Compress and send a frame. 1248 * The caller should have locked the xmit path, 1249 * and xmit_pending should be 0. 1250 */ 1251 static void 1252 ppp_send_frame(struct ppp *ppp, struct sk_buff *skb) 1253 { 1254 int proto = PPP_PROTO(skb); 1255 struct sk_buff *new_skb; 1256 int len; 1257 unsigned char *cp; 1258 1259 if (proto < 0x8000) { 1260 #ifdef CONFIG_PPP_FILTER 1261 /* check if we should pass this packet */ 1262 /* the filter instructions are constructed assuming 1263 a four-byte PPP header on each packet */ 1264 *skb_push(skb, 2) = 1; 1265 if (ppp->pass_filter && 1266 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 1267 if (ppp->debug & 1) 1268 netdev_printk(KERN_DEBUG, ppp->dev, 1269 "PPP: outbound frame " 1270 "not passed\n"); 1271 kfree_skb(skb); 1272 return; 1273 } 1274 /* if this packet passes the active filter, record the time */ 1275 if (!(ppp->active_filter && 1276 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 1277 ppp->last_xmit = jiffies; 1278 skb_pull(skb, 2); 1279 #else 1280 /* for data packets, record the time */ 1281 ppp->last_xmit = jiffies; 1282 #endif /* CONFIG_PPP_FILTER */ 1283 } 1284 1285 ++ppp->stats64.tx_packets; 1286 ppp->stats64.tx_bytes += skb->len - 2; 1287 1288 switch (proto) { 1289 case PPP_IP: 1290 if (!ppp->vj || (ppp->flags & SC_COMP_TCP) == 0) 1291 break; 1292 /* try to do VJ TCP header compression */ 1293 new_skb = alloc_skb(skb->len + ppp->dev->hard_header_len - 2, 1294 GFP_ATOMIC); 1295 if (!new_skb) { 1296 netdev_err(ppp->dev, "PPP: no memory (VJ comp pkt)\n"); 1297 goto drop; 1298 } 1299 skb_reserve(new_skb, ppp->dev->hard_header_len - 2); 1300 cp = skb->data + 2; 1301 len = slhc_compress(ppp->vj, cp, skb->len - 2, 1302 new_skb->data + 2, &cp, 1303 !(ppp->flags & SC_NO_TCP_CCID)); 1304 if (cp == skb->data + 2) { 1305 /* didn't compress */ 1306 consume_skb(new_skb); 1307 } else { 1308 if (cp[0] & SL_TYPE_COMPRESSED_TCP) { 1309 proto = PPP_VJC_COMP; 1310 cp[0] &= ~SL_TYPE_COMPRESSED_TCP; 1311 } else { 1312 proto = PPP_VJC_UNCOMP; 1313 cp[0] = skb->data[2]; 1314 } 1315 consume_skb(skb); 1316 skb = new_skb; 1317 cp = skb_put(skb, len + 2); 1318 cp[0] = 0; 1319 cp[1] = proto; 1320 } 1321 break; 1322 1323 case PPP_CCP: 1324 /* peek at outbound CCP frames */ 1325 ppp_ccp_peek(ppp, skb, 0); 1326 break; 1327 } 1328 1329 /* try to do packet compression */ 1330 if ((ppp->xstate & SC_COMP_RUN) && ppp->xc_state && 1331 proto != PPP_LCP && proto != PPP_CCP) { 1332 if (!(ppp->flags & SC_CCP_UP) && (ppp->flags & SC_MUST_COMP)) { 1333 if (net_ratelimit()) 1334 netdev_err(ppp->dev, 1335 "ppp: compression required but " 1336 "down - pkt dropped.\n"); 1337 goto drop; 1338 } 1339 skb = pad_compress_skb(ppp, skb); 1340 if (!skb) 1341 goto drop; 1342 } 1343 1344 /* 1345 * If we are waiting for traffic (demand dialling), 1346 * queue it up for pppd to receive. 1347 */ 1348 if (ppp->flags & SC_LOOP_TRAFFIC) { 1349 if (ppp->file.rq.qlen > PPP_MAX_RQLEN) 1350 goto drop; 1351 skb_queue_tail(&ppp->file.rq, skb); 1352 wake_up_interruptible(&ppp->file.rwait); 1353 return; 1354 } 1355 1356 ppp->xmit_pending = skb; 1357 ppp_push(ppp); 1358 return; 1359 1360 drop: 1361 kfree_skb(skb); 1362 ++ppp->dev->stats.tx_errors; 1363 } 1364 1365 /* 1366 * Try to send the frame in xmit_pending. 1367 * The caller should have the xmit path locked. 1368 */ 1369 static void 1370 ppp_push(struct ppp *ppp) 1371 { 1372 struct list_head *list; 1373 struct channel *pch; 1374 struct sk_buff *skb = ppp->xmit_pending; 1375 1376 if (!skb) 1377 return; 1378 1379 list = &ppp->channels; 1380 if (list_empty(list)) { 1381 /* nowhere to send the packet, just drop it */ 1382 ppp->xmit_pending = NULL; 1383 kfree_skb(skb); 1384 return; 1385 } 1386 1387 if ((ppp->flags & SC_MULTILINK) == 0) { 1388 /* not doing multilink: send it down the first channel */ 1389 list = list->next; 1390 pch = list_entry(list, struct channel, clist); 1391 1392 spin_lock_bh(&pch->downl); 1393 if (pch->chan) { 1394 if (pch->chan->ops->start_xmit(pch->chan, skb)) 1395 ppp->xmit_pending = NULL; 1396 } else { 1397 /* channel got unregistered */ 1398 kfree_skb(skb); 1399 ppp->xmit_pending = NULL; 1400 } 1401 spin_unlock_bh(&pch->downl); 1402 return; 1403 } 1404 1405 #ifdef CONFIG_PPP_MULTILINK 1406 /* Multilink: fragment the packet over as many links 1407 as can take the packet at the moment. */ 1408 if (!ppp_mp_explode(ppp, skb)) 1409 return; 1410 #endif /* CONFIG_PPP_MULTILINK */ 1411 1412 ppp->xmit_pending = NULL; 1413 kfree_skb(skb); 1414 } 1415 1416 #ifdef CONFIG_PPP_MULTILINK 1417 static bool mp_protocol_compress __read_mostly = true; 1418 module_param(mp_protocol_compress, bool, S_IRUGO | S_IWUSR); 1419 MODULE_PARM_DESC(mp_protocol_compress, 1420 "compress protocol id in multilink fragments"); 1421 1422 /* 1423 * Divide a packet to be transmitted into fragments and 1424 * send them out the individual links. 1425 */ 1426 static int ppp_mp_explode(struct ppp *ppp, struct sk_buff *skb) 1427 { 1428 int len, totlen; 1429 int i, bits, hdrlen, mtu; 1430 int flen; 1431 int navail, nfree, nzero; 1432 int nbigger; 1433 int totspeed; 1434 int totfree; 1435 unsigned char *p, *q; 1436 struct list_head *list; 1437 struct channel *pch; 1438 struct sk_buff *frag; 1439 struct ppp_channel *chan; 1440 1441 totspeed = 0; /*total bitrate of the bundle*/ 1442 nfree = 0; /* # channels which have no packet already queued */ 1443 navail = 0; /* total # of usable channels (not deregistered) */ 1444 nzero = 0; /* number of channels with zero speed associated*/ 1445 totfree = 0; /*total # of channels available and 1446 *having no queued packets before 1447 *starting the fragmentation*/ 1448 1449 hdrlen = (ppp->flags & SC_MP_XSHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 1450 i = 0; 1451 list_for_each_entry(pch, &ppp->channels, clist) { 1452 if (pch->chan) { 1453 pch->avail = 1; 1454 navail++; 1455 pch->speed = pch->chan->speed; 1456 } else { 1457 pch->avail = 0; 1458 } 1459 if (pch->avail) { 1460 if (skb_queue_empty(&pch->file.xq) || 1461 !pch->had_frag) { 1462 if (pch->speed == 0) 1463 nzero++; 1464 else 1465 totspeed += pch->speed; 1466 1467 pch->avail = 2; 1468 ++nfree; 1469 ++totfree; 1470 } 1471 if (!pch->had_frag && i < ppp->nxchan) 1472 ppp->nxchan = i; 1473 } 1474 ++i; 1475 } 1476 /* 1477 * Don't start sending this packet unless at least half of 1478 * the channels are free. This gives much better TCP 1479 * performance if we have a lot of channels. 1480 */ 1481 if (nfree == 0 || nfree < navail / 2) 1482 return 0; /* can't take now, leave it in xmit_pending */ 1483 1484 /* Do protocol field compression */ 1485 p = skb->data; 1486 len = skb->len; 1487 if (*p == 0 && mp_protocol_compress) { 1488 ++p; 1489 --len; 1490 } 1491 1492 totlen = len; 1493 nbigger = len % nfree; 1494 1495 /* skip to the channel after the one we last used 1496 and start at that one */ 1497 list = &ppp->channels; 1498 for (i = 0; i < ppp->nxchan; ++i) { 1499 list = list->next; 1500 if (list == &ppp->channels) { 1501 i = 0; 1502 break; 1503 } 1504 } 1505 1506 /* create a fragment for each channel */ 1507 bits = B; 1508 while (len > 0) { 1509 list = list->next; 1510 if (list == &ppp->channels) { 1511 i = 0; 1512 continue; 1513 } 1514 pch = list_entry(list, struct channel, clist); 1515 ++i; 1516 if (!pch->avail) 1517 continue; 1518 1519 /* 1520 * Skip this channel if it has a fragment pending already and 1521 * we haven't given a fragment to all of the free channels. 1522 */ 1523 if (pch->avail == 1) { 1524 if (nfree > 0) 1525 continue; 1526 } else { 1527 pch->avail = 1; 1528 } 1529 1530 /* check the channel's mtu and whether it is still attached. */ 1531 spin_lock_bh(&pch->downl); 1532 if (pch->chan == NULL) { 1533 /* can't use this channel, it's being deregistered */ 1534 if (pch->speed == 0) 1535 nzero--; 1536 else 1537 totspeed -= pch->speed; 1538 1539 spin_unlock_bh(&pch->downl); 1540 pch->avail = 0; 1541 totlen = len; 1542 totfree--; 1543 nfree--; 1544 if (--navail == 0) 1545 break; 1546 continue; 1547 } 1548 1549 /* 1550 *if the channel speed is not set divide 1551 *the packet evenly among the free channels; 1552 *otherwise divide it according to the speed 1553 *of the channel we are going to transmit on 1554 */ 1555 flen = len; 1556 if (nfree > 0) { 1557 if (pch->speed == 0) { 1558 flen = len/nfree; 1559 if (nbigger > 0) { 1560 flen++; 1561 nbigger--; 1562 } 1563 } else { 1564 flen = (((totfree - nzero)*(totlen + hdrlen*totfree)) / 1565 ((totspeed*totfree)/pch->speed)) - hdrlen; 1566 if (nbigger > 0) { 1567 flen += ((totfree - nzero)*pch->speed)/totspeed; 1568 nbigger -= ((totfree - nzero)*pch->speed)/ 1569 totspeed; 1570 } 1571 } 1572 nfree--; 1573 } 1574 1575 /* 1576 *check if we are on the last channel or 1577 *we exceded the length of the data to 1578 *fragment 1579 */ 1580 if ((nfree <= 0) || (flen > len)) 1581 flen = len; 1582 /* 1583 *it is not worth to tx on slow channels: 1584 *in that case from the resulting flen according to the 1585 *above formula will be equal or less than zero. 1586 *Skip the channel in this case 1587 */ 1588 if (flen <= 0) { 1589 pch->avail = 2; 1590 spin_unlock_bh(&pch->downl); 1591 continue; 1592 } 1593 1594 /* 1595 * hdrlen includes the 2-byte PPP protocol field, but the 1596 * MTU counts only the payload excluding the protocol field. 1597 * (RFC1661 Section 2) 1598 */ 1599 mtu = pch->chan->mtu - (hdrlen - 2); 1600 if (mtu < 4) 1601 mtu = 4; 1602 if (flen > mtu) 1603 flen = mtu; 1604 if (flen == len) 1605 bits |= E; 1606 frag = alloc_skb(flen + hdrlen + (flen == 0), GFP_ATOMIC); 1607 if (!frag) 1608 goto noskb; 1609 q = skb_put(frag, flen + hdrlen); 1610 1611 /* make the MP header */ 1612 put_unaligned_be16(PPP_MP, q); 1613 if (ppp->flags & SC_MP_XSHORTSEQ) { 1614 q[2] = bits + ((ppp->nxseq >> 8) & 0xf); 1615 q[3] = ppp->nxseq; 1616 } else { 1617 q[2] = bits; 1618 q[3] = ppp->nxseq >> 16; 1619 q[4] = ppp->nxseq >> 8; 1620 q[5] = ppp->nxseq; 1621 } 1622 1623 memcpy(q + hdrlen, p, flen); 1624 1625 /* try to send it down the channel */ 1626 chan = pch->chan; 1627 if (!skb_queue_empty(&pch->file.xq) || 1628 !chan->ops->start_xmit(chan, frag)) 1629 skb_queue_tail(&pch->file.xq, frag); 1630 pch->had_frag = 1; 1631 p += flen; 1632 len -= flen; 1633 ++ppp->nxseq; 1634 bits = 0; 1635 spin_unlock_bh(&pch->downl); 1636 } 1637 ppp->nxchan = i; 1638 1639 return 1; 1640 1641 noskb: 1642 spin_unlock_bh(&pch->downl); 1643 if (ppp->debug & 1) 1644 netdev_err(ppp->dev, "PPP: no memory (fragment)\n"); 1645 ++ppp->dev->stats.tx_errors; 1646 ++ppp->nxseq; 1647 return 1; /* abandon the frame */ 1648 } 1649 #endif /* CONFIG_PPP_MULTILINK */ 1650 1651 /* 1652 * Try to send data out on a channel. 1653 */ 1654 static void 1655 ppp_channel_push(struct channel *pch) 1656 { 1657 struct sk_buff *skb; 1658 struct ppp *ppp; 1659 1660 spin_lock_bh(&pch->downl); 1661 if (pch->chan) { 1662 while (!skb_queue_empty(&pch->file.xq)) { 1663 skb = skb_dequeue(&pch->file.xq); 1664 if (!pch->chan->ops->start_xmit(pch->chan, skb)) { 1665 /* put the packet back and try again later */ 1666 skb_queue_head(&pch->file.xq, skb); 1667 break; 1668 } 1669 } 1670 } else { 1671 /* channel got deregistered */ 1672 skb_queue_purge(&pch->file.xq); 1673 } 1674 spin_unlock_bh(&pch->downl); 1675 /* see if there is anything from the attached unit to be sent */ 1676 if (skb_queue_empty(&pch->file.xq)) { 1677 read_lock_bh(&pch->upl); 1678 ppp = pch->ppp; 1679 if (ppp) 1680 ppp_xmit_process(ppp); 1681 read_unlock_bh(&pch->upl); 1682 } 1683 } 1684 1685 /* 1686 * Receive-side routines. 1687 */ 1688 1689 struct ppp_mp_skb_parm { 1690 u32 sequence; 1691 u8 BEbits; 1692 }; 1693 #define PPP_MP_CB(skb) ((struct ppp_mp_skb_parm *)((skb)->cb)) 1694 1695 static inline void 1696 ppp_do_recv(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1697 { 1698 ppp_recv_lock(ppp); 1699 if (!ppp->closing) 1700 ppp_receive_frame(ppp, skb, pch); 1701 else 1702 kfree_skb(skb); 1703 ppp_recv_unlock(ppp); 1704 } 1705 1706 void 1707 ppp_input(struct ppp_channel *chan, struct sk_buff *skb) 1708 { 1709 struct channel *pch = chan->ppp; 1710 int proto; 1711 1712 if (!pch) { 1713 kfree_skb(skb); 1714 return; 1715 } 1716 1717 read_lock_bh(&pch->upl); 1718 if (!pskb_may_pull(skb, 2)) { 1719 kfree_skb(skb); 1720 if (pch->ppp) { 1721 ++pch->ppp->dev->stats.rx_length_errors; 1722 ppp_receive_error(pch->ppp); 1723 } 1724 goto done; 1725 } 1726 1727 proto = PPP_PROTO(skb); 1728 if (!pch->ppp || proto >= 0xc000 || proto == PPP_CCPFRAG) { 1729 /* put it on the channel queue */ 1730 skb_queue_tail(&pch->file.rq, skb); 1731 /* drop old frames if queue too long */ 1732 while (pch->file.rq.qlen > PPP_MAX_RQLEN && 1733 (skb = skb_dequeue(&pch->file.rq))) 1734 kfree_skb(skb); 1735 wake_up_interruptible(&pch->file.rwait); 1736 } else { 1737 ppp_do_recv(pch->ppp, skb, pch); 1738 } 1739 1740 done: 1741 read_unlock_bh(&pch->upl); 1742 } 1743 1744 /* Put a 0-length skb in the receive queue as an error indication */ 1745 void 1746 ppp_input_error(struct ppp_channel *chan, int code) 1747 { 1748 struct channel *pch = chan->ppp; 1749 struct sk_buff *skb; 1750 1751 if (!pch) 1752 return; 1753 1754 read_lock_bh(&pch->upl); 1755 if (pch->ppp) { 1756 skb = alloc_skb(0, GFP_ATOMIC); 1757 if (skb) { 1758 skb->len = 0; /* probably unnecessary */ 1759 skb->cb[0] = code; 1760 ppp_do_recv(pch->ppp, skb, pch); 1761 } 1762 } 1763 read_unlock_bh(&pch->upl); 1764 } 1765 1766 /* 1767 * We come in here to process a received frame. 1768 * The receive side of the ppp unit is locked. 1769 */ 1770 static void 1771 ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 1772 { 1773 /* note: a 0-length skb is used as an error indication */ 1774 if (skb->len > 0) { 1775 skb_checksum_complete_unset(skb); 1776 #ifdef CONFIG_PPP_MULTILINK 1777 /* XXX do channel-level decompression here */ 1778 if (PPP_PROTO(skb) == PPP_MP) 1779 ppp_receive_mp_frame(ppp, skb, pch); 1780 else 1781 #endif /* CONFIG_PPP_MULTILINK */ 1782 ppp_receive_nonmp_frame(ppp, skb); 1783 } else { 1784 kfree_skb(skb); 1785 ppp_receive_error(ppp); 1786 } 1787 } 1788 1789 static void 1790 ppp_receive_error(struct ppp *ppp) 1791 { 1792 ++ppp->dev->stats.rx_errors; 1793 if (ppp->vj) 1794 slhc_toss(ppp->vj); 1795 } 1796 1797 static void 1798 ppp_receive_nonmp_frame(struct ppp *ppp, struct sk_buff *skb) 1799 { 1800 struct sk_buff *ns; 1801 int proto, len, npi; 1802 1803 /* 1804 * Decompress the frame, if compressed. 1805 * Note that some decompressors need to see uncompressed frames 1806 * that come in as well as compressed frames. 1807 */ 1808 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN) && 1809 (ppp->rstate & (SC_DC_FERROR | SC_DC_ERROR)) == 0) 1810 skb = ppp_decompress_frame(ppp, skb); 1811 1812 if (ppp->flags & SC_MUST_COMP && ppp->rstate & SC_DC_FERROR) 1813 goto err; 1814 1815 proto = PPP_PROTO(skb); 1816 switch (proto) { 1817 case PPP_VJC_COMP: 1818 /* decompress VJ compressed packets */ 1819 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 1820 goto err; 1821 1822 if (skb_tailroom(skb) < 124 || skb_cloned(skb)) { 1823 /* copy to a new sk_buff with more tailroom */ 1824 ns = dev_alloc_skb(skb->len + 128); 1825 if (!ns) { 1826 netdev_err(ppp->dev, "PPP: no memory " 1827 "(VJ decomp)\n"); 1828 goto err; 1829 } 1830 skb_reserve(ns, 2); 1831 skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len); 1832 consume_skb(skb); 1833 skb = ns; 1834 } 1835 else 1836 skb->ip_summed = CHECKSUM_NONE; 1837 1838 len = slhc_uncompress(ppp->vj, skb->data + 2, skb->len - 2); 1839 if (len <= 0) { 1840 netdev_printk(KERN_DEBUG, ppp->dev, 1841 "PPP: VJ decompression error\n"); 1842 goto err; 1843 } 1844 len += 2; 1845 if (len > skb->len) 1846 skb_put(skb, len - skb->len); 1847 else if (len < skb->len) 1848 skb_trim(skb, len); 1849 proto = PPP_IP; 1850 break; 1851 1852 case PPP_VJC_UNCOMP: 1853 if (!ppp->vj || (ppp->flags & SC_REJ_COMP_TCP)) 1854 goto err; 1855 1856 /* Until we fix the decompressor need to make sure 1857 * data portion is linear. 1858 */ 1859 if (!pskb_may_pull(skb, skb->len)) 1860 goto err; 1861 1862 if (slhc_remember(ppp->vj, skb->data + 2, skb->len - 2) <= 0) { 1863 netdev_err(ppp->dev, "PPP: VJ uncompressed error\n"); 1864 goto err; 1865 } 1866 proto = PPP_IP; 1867 break; 1868 1869 case PPP_CCP: 1870 ppp_ccp_peek(ppp, skb, 1); 1871 break; 1872 } 1873 1874 ++ppp->stats64.rx_packets; 1875 ppp->stats64.rx_bytes += skb->len - 2; 1876 1877 npi = proto_to_npindex(proto); 1878 if (npi < 0) { 1879 /* control or unknown frame - pass it to pppd */ 1880 skb_queue_tail(&ppp->file.rq, skb); 1881 /* limit queue length by dropping old frames */ 1882 while (ppp->file.rq.qlen > PPP_MAX_RQLEN && 1883 (skb = skb_dequeue(&ppp->file.rq))) 1884 kfree_skb(skb); 1885 /* wake up any process polling or blocking on read */ 1886 wake_up_interruptible(&ppp->file.rwait); 1887 1888 } else { 1889 /* network protocol frame - give it to the kernel */ 1890 1891 #ifdef CONFIG_PPP_FILTER 1892 /* check if the packet passes the pass and active filters */ 1893 /* the filter instructions are constructed assuming 1894 a four-byte PPP header on each packet */ 1895 if (ppp->pass_filter || ppp->active_filter) { 1896 if (skb_unclone(skb, GFP_ATOMIC)) 1897 goto err; 1898 1899 *skb_push(skb, 2) = 0; 1900 if (ppp->pass_filter && 1901 BPF_PROG_RUN(ppp->pass_filter, skb) == 0) { 1902 if (ppp->debug & 1) 1903 netdev_printk(KERN_DEBUG, ppp->dev, 1904 "PPP: inbound frame " 1905 "not passed\n"); 1906 kfree_skb(skb); 1907 return; 1908 } 1909 if (!(ppp->active_filter && 1910 BPF_PROG_RUN(ppp->active_filter, skb) == 0)) 1911 ppp->last_recv = jiffies; 1912 __skb_pull(skb, 2); 1913 } else 1914 #endif /* CONFIG_PPP_FILTER */ 1915 ppp->last_recv = jiffies; 1916 1917 if ((ppp->dev->flags & IFF_UP) == 0 || 1918 ppp->npmode[npi] != NPMODE_PASS) { 1919 kfree_skb(skb); 1920 } else { 1921 /* chop off protocol */ 1922 skb_pull_rcsum(skb, 2); 1923 skb->dev = ppp->dev; 1924 skb->protocol = htons(npindex_to_ethertype[npi]); 1925 skb_reset_mac_header(skb); 1926 skb_scrub_packet(skb, !net_eq(ppp->ppp_net, 1927 dev_net(ppp->dev))); 1928 netif_rx(skb); 1929 } 1930 } 1931 return; 1932 1933 err: 1934 kfree_skb(skb); 1935 ppp_receive_error(ppp); 1936 } 1937 1938 static struct sk_buff * 1939 ppp_decompress_frame(struct ppp *ppp, struct sk_buff *skb) 1940 { 1941 int proto = PPP_PROTO(skb); 1942 struct sk_buff *ns; 1943 int len; 1944 1945 /* Until we fix all the decompressor's need to make sure 1946 * data portion is linear. 1947 */ 1948 if (!pskb_may_pull(skb, skb->len)) 1949 goto err; 1950 1951 if (proto == PPP_COMP) { 1952 int obuff_size; 1953 1954 switch(ppp->rcomp->compress_proto) { 1955 case CI_MPPE: 1956 obuff_size = ppp->mru + PPP_HDRLEN + 1; 1957 break; 1958 default: 1959 obuff_size = ppp->mru + PPP_HDRLEN; 1960 break; 1961 } 1962 1963 ns = dev_alloc_skb(obuff_size); 1964 if (!ns) { 1965 netdev_err(ppp->dev, "ppp_decompress_frame: " 1966 "no memory\n"); 1967 goto err; 1968 } 1969 /* the decompressor still expects the A/C bytes in the hdr */ 1970 len = ppp->rcomp->decompress(ppp->rc_state, skb->data - 2, 1971 skb->len + 2, ns->data, obuff_size); 1972 if (len < 0) { 1973 /* Pass the compressed frame to pppd as an 1974 error indication. */ 1975 if (len == DECOMP_FATALERROR) 1976 ppp->rstate |= SC_DC_FERROR; 1977 kfree_skb(ns); 1978 goto err; 1979 } 1980 1981 consume_skb(skb); 1982 skb = ns; 1983 skb_put(skb, len); 1984 skb_pull(skb, 2); /* pull off the A/C bytes */ 1985 1986 } else { 1987 /* Uncompressed frame - pass to decompressor so it 1988 can update its dictionary if necessary. */ 1989 if (ppp->rcomp->incomp) 1990 ppp->rcomp->incomp(ppp->rc_state, skb->data - 2, 1991 skb->len + 2); 1992 } 1993 1994 return skb; 1995 1996 err: 1997 ppp->rstate |= SC_DC_ERROR; 1998 ppp_receive_error(ppp); 1999 return skb; 2000 } 2001 2002 #ifdef CONFIG_PPP_MULTILINK 2003 /* 2004 * Receive a multilink frame. 2005 * We put it on the reconstruction queue and then pull off 2006 * as many completed frames as we can. 2007 */ 2008 static void 2009 ppp_receive_mp_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 2010 { 2011 u32 mask, seq; 2012 struct channel *ch; 2013 int mphdrlen = (ppp->flags & SC_MP_SHORTSEQ)? MPHDRLEN_SSN: MPHDRLEN; 2014 2015 if (!pskb_may_pull(skb, mphdrlen + 1) || ppp->mrru == 0) 2016 goto err; /* no good, throw it away */ 2017 2018 /* Decode sequence number and begin/end bits */ 2019 if (ppp->flags & SC_MP_SHORTSEQ) { 2020 seq = ((skb->data[2] & 0x0f) << 8) | skb->data[3]; 2021 mask = 0xfff; 2022 } else { 2023 seq = (skb->data[3] << 16) | (skb->data[4] << 8)| skb->data[5]; 2024 mask = 0xffffff; 2025 } 2026 PPP_MP_CB(skb)->BEbits = skb->data[2]; 2027 skb_pull(skb, mphdrlen); /* pull off PPP and MP headers */ 2028 2029 /* 2030 * Do protocol ID decompression on the first fragment of each packet. 2031 */ 2032 if ((PPP_MP_CB(skb)->BEbits & B) && (skb->data[0] & 1)) 2033 *skb_push(skb, 1) = 0; 2034 2035 /* 2036 * Expand sequence number to 32 bits, making it as close 2037 * as possible to ppp->minseq. 2038 */ 2039 seq |= ppp->minseq & ~mask; 2040 if ((int)(ppp->minseq - seq) > (int)(mask >> 1)) 2041 seq += mask + 1; 2042 else if ((int)(seq - ppp->minseq) > (int)(mask >> 1)) 2043 seq -= mask + 1; /* should never happen */ 2044 PPP_MP_CB(skb)->sequence = seq; 2045 pch->lastseq = seq; 2046 2047 /* 2048 * If this packet comes before the next one we were expecting, 2049 * drop it. 2050 */ 2051 if (seq_before(seq, ppp->nextseq)) { 2052 kfree_skb(skb); 2053 ++ppp->dev->stats.rx_dropped; 2054 ppp_receive_error(ppp); 2055 return; 2056 } 2057 2058 /* 2059 * Reevaluate minseq, the minimum over all channels of the 2060 * last sequence number received on each channel. Because of 2061 * the increasing sequence number rule, we know that any fragment 2062 * before `minseq' which hasn't arrived is never going to arrive. 2063 * The list of channels can't change because we have the receive 2064 * side of the ppp unit locked. 2065 */ 2066 list_for_each_entry(ch, &ppp->channels, clist) { 2067 if (seq_before(ch->lastseq, seq)) 2068 seq = ch->lastseq; 2069 } 2070 if (seq_before(ppp->minseq, seq)) 2071 ppp->minseq = seq; 2072 2073 /* Put the fragment on the reconstruction queue */ 2074 ppp_mp_insert(ppp, skb); 2075 2076 /* If the queue is getting long, don't wait any longer for packets 2077 before the start of the queue. */ 2078 if (skb_queue_len(&ppp->mrq) >= PPP_MP_MAX_QLEN) { 2079 struct sk_buff *mskb = skb_peek(&ppp->mrq); 2080 if (seq_before(ppp->minseq, PPP_MP_CB(mskb)->sequence)) 2081 ppp->minseq = PPP_MP_CB(mskb)->sequence; 2082 } 2083 2084 /* Pull completed packets off the queue and receive them. */ 2085 while ((skb = ppp_mp_reconstruct(ppp))) { 2086 if (pskb_may_pull(skb, 2)) 2087 ppp_receive_nonmp_frame(ppp, skb); 2088 else { 2089 ++ppp->dev->stats.rx_length_errors; 2090 kfree_skb(skb); 2091 ppp_receive_error(ppp); 2092 } 2093 } 2094 2095 return; 2096 2097 err: 2098 kfree_skb(skb); 2099 ppp_receive_error(ppp); 2100 } 2101 2102 /* 2103 * Insert a fragment on the MP reconstruction queue. 2104 * The queue is ordered by increasing sequence number. 2105 */ 2106 static void 2107 ppp_mp_insert(struct ppp *ppp, struct sk_buff *skb) 2108 { 2109 struct sk_buff *p; 2110 struct sk_buff_head *list = &ppp->mrq; 2111 u32 seq = PPP_MP_CB(skb)->sequence; 2112 2113 /* N.B. we don't need to lock the list lock because we have the 2114 ppp unit receive-side lock. */ 2115 skb_queue_walk(list, p) { 2116 if (seq_before(seq, PPP_MP_CB(p)->sequence)) 2117 break; 2118 } 2119 __skb_queue_before(list, p, skb); 2120 } 2121 2122 /* 2123 * Reconstruct a packet from the MP fragment queue. 2124 * We go through increasing sequence numbers until we find a 2125 * complete packet, or we get to the sequence number for a fragment 2126 * which hasn't arrived but might still do so. 2127 */ 2128 static struct sk_buff * 2129 ppp_mp_reconstruct(struct ppp *ppp) 2130 { 2131 u32 seq = ppp->nextseq; 2132 u32 minseq = ppp->minseq; 2133 struct sk_buff_head *list = &ppp->mrq; 2134 struct sk_buff *p, *tmp; 2135 struct sk_buff *head, *tail; 2136 struct sk_buff *skb = NULL; 2137 int lost = 0, len = 0; 2138 2139 if (ppp->mrru == 0) /* do nothing until mrru is set */ 2140 return NULL; 2141 head = list->next; 2142 tail = NULL; 2143 skb_queue_walk_safe(list, p, tmp) { 2144 again: 2145 if (seq_before(PPP_MP_CB(p)->sequence, seq)) { 2146 /* this can't happen, anyway ignore the skb */ 2147 netdev_err(ppp->dev, "ppp_mp_reconstruct bad " 2148 "seq %u < %u\n", 2149 PPP_MP_CB(p)->sequence, seq); 2150 __skb_unlink(p, list); 2151 kfree_skb(p); 2152 continue; 2153 } 2154 if (PPP_MP_CB(p)->sequence != seq) { 2155 u32 oldseq; 2156 /* Fragment `seq' is missing. If it is after 2157 minseq, it might arrive later, so stop here. */ 2158 if (seq_after(seq, minseq)) 2159 break; 2160 /* Fragment `seq' is lost, keep going. */ 2161 lost = 1; 2162 oldseq = seq; 2163 seq = seq_before(minseq, PPP_MP_CB(p)->sequence)? 2164 minseq + 1: PPP_MP_CB(p)->sequence; 2165 2166 if (ppp->debug & 1) 2167 netdev_printk(KERN_DEBUG, ppp->dev, 2168 "lost frag %u..%u\n", 2169 oldseq, seq-1); 2170 2171 goto again; 2172 } 2173 2174 /* 2175 * At this point we know that all the fragments from 2176 * ppp->nextseq to seq are either present or lost. 2177 * Also, there are no complete packets in the queue 2178 * that have no missing fragments and end before this 2179 * fragment. 2180 */ 2181 2182 /* B bit set indicates this fragment starts a packet */ 2183 if (PPP_MP_CB(p)->BEbits & B) { 2184 head = p; 2185 lost = 0; 2186 len = 0; 2187 } 2188 2189 len += p->len; 2190 2191 /* Got a complete packet yet? */ 2192 if (lost == 0 && (PPP_MP_CB(p)->BEbits & E) && 2193 (PPP_MP_CB(head)->BEbits & B)) { 2194 if (len > ppp->mrru + 2) { 2195 ++ppp->dev->stats.rx_length_errors; 2196 netdev_printk(KERN_DEBUG, ppp->dev, 2197 "PPP: reconstructed packet" 2198 " is too long (%d)\n", len); 2199 } else { 2200 tail = p; 2201 break; 2202 } 2203 ppp->nextseq = seq + 1; 2204 } 2205 2206 /* 2207 * If this is the ending fragment of a packet, 2208 * and we haven't found a complete valid packet yet, 2209 * we can discard up to and including this fragment. 2210 */ 2211 if (PPP_MP_CB(p)->BEbits & E) { 2212 struct sk_buff *tmp2; 2213 2214 skb_queue_reverse_walk_from_safe(list, p, tmp2) { 2215 if (ppp->debug & 1) 2216 netdev_printk(KERN_DEBUG, ppp->dev, 2217 "discarding frag %u\n", 2218 PPP_MP_CB(p)->sequence); 2219 __skb_unlink(p, list); 2220 kfree_skb(p); 2221 } 2222 head = skb_peek(list); 2223 if (!head) 2224 break; 2225 } 2226 ++seq; 2227 } 2228 2229 /* If we have a complete packet, copy it all into one skb. */ 2230 if (tail != NULL) { 2231 /* If we have discarded any fragments, 2232 signal a receive error. */ 2233 if (PPP_MP_CB(head)->sequence != ppp->nextseq) { 2234 skb_queue_walk_safe(list, p, tmp) { 2235 if (p == head) 2236 break; 2237 if (ppp->debug & 1) 2238 netdev_printk(KERN_DEBUG, ppp->dev, 2239 "discarding frag %u\n", 2240 PPP_MP_CB(p)->sequence); 2241 __skb_unlink(p, list); 2242 kfree_skb(p); 2243 } 2244 2245 if (ppp->debug & 1) 2246 netdev_printk(KERN_DEBUG, ppp->dev, 2247 " missed pkts %u..%u\n", 2248 ppp->nextseq, 2249 PPP_MP_CB(head)->sequence-1); 2250 ++ppp->dev->stats.rx_dropped; 2251 ppp_receive_error(ppp); 2252 } 2253 2254 skb = head; 2255 if (head != tail) { 2256 struct sk_buff **fragpp = &skb_shinfo(skb)->frag_list; 2257 p = skb_queue_next(list, head); 2258 __skb_unlink(skb, list); 2259 skb_queue_walk_from_safe(list, p, tmp) { 2260 __skb_unlink(p, list); 2261 *fragpp = p; 2262 p->next = NULL; 2263 fragpp = &p->next; 2264 2265 skb->len += p->len; 2266 skb->data_len += p->len; 2267 skb->truesize += p->truesize; 2268 2269 if (p == tail) 2270 break; 2271 } 2272 } else { 2273 __skb_unlink(skb, list); 2274 } 2275 2276 ppp->nextseq = PPP_MP_CB(tail)->sequence + 1; 2277 } 2278 2279 return skb; 2280 } 2281 #endif /* CONFIG_PPP_MULTILINK */ 2282 2283 /* 2284 * Channel interface. 2285 */ 2286 2287 /* Create a new, unattached ppp channel. */ 2288 int ppp_register_channel(struct ppp_channel *chan) 2289 { 2290 return ppp_register_net_channel(current->nsproxy->net_ns, chan); 2291 } 2292 2293 /* Create a new, unattached ppp channel for specified net. */ 2294 int ppp_register_net_channel(struct net *net, struct ppp_channel *chan) 2295 { 2296 struct channel *pch; 2297 struct ppp_net *pn; 2298 2299 pch = kzalloc(sizeof(struct channel), GFP_KERNEL); 2300 if (!pch) 2301 return -ENOMEM; 2302 2303 pn = ppp_pernet(net); 2304 2305 pch->ppp = NULL; 2306 pch->chan = chan; 2307 pch->chan_net = net; 2308 chan->ppp = pch; 2309 init_ppp_file(&pch->file, CHANNEL); 2310 pch->file.hdrlen = chan->hdrlen; 2311 #ifdef CONFIG_PPP_MULTILINK 2312 pch->lastseq = -1; 2313 #endif /* CONFIG_PPP_MULTILINK */ 2314 init_rwsem(&pch->chan_sem); 2315 spin_lock_init(&pch->downl); 2316 rwlock_init(&pch->upl); 2317 2318 spin_lock_bh(&pn->all_channels_lock); 2319 pch->file.index = ++pn->last_channel_index; 2320 list_add(&pch->list, &pn->new_channels); 2321 atomic_inc(&channel_count); 2322 spin_unlock_bh(&pn->all_channels_lock); 2323 2324 return 0; 2325 } 2326 2327 /* 2328 * Return the index of a channel. 2329 */ 2330 int ppp_channel_index(struct ppp_channel *chan) 2331 { 2332 struct channel *pch = chan->ppp; 2333 2334 if (pch) 2335 return pch->file.index; 2336 return -1; 2337 } 2338 2339 /* 2340 * Return the PPP unit number to which a channel is connected. 2341 */ 2342 int ppp_unit_number(struct ppp_channel *chan) 2343 { 2344 struct channel *pch = chan->ppp; 2345 int unit = -1; 2346 2347 if (pch) { 2348 read_lock_bh(&pch->upl); 2349 if (pch->ppp) 2350 unit = pch->ppp->file.index; 2351 read_unlock_bh(&pch->upl); 2352 } 2353 return unit; 2354 } 2355 2356 /* 2357 * Return the PPP device interface name of a channel. 2358 */ 2359 char *ppp_dev_name(struct ppp_channel *chan) 2360 { 2361 struct channel *pch = chan->ppp; 2362 char *name = NULL; 2363 2364 if (pch) { 2365 read_lock_bh(&pch->upl); 2366 if (pch->ppp && pch->ppp->dev) 2367 name = pch->ppp->dev->name; 2368 read_unlock_bh(&pch->upl); 2369 } 2370 return name; 2371 } 2372 2373 2374 /* 2375 * Disconnect a channel from the generic layer. 2376 * This must be called in process context. 2377 */ 2378 void 2379 ppp_unregister_channel(struct ppp_channel *chan) 2380 { 2381 struct channel *pch = chan->ppp; 2382 struct ppp_net *pn; 2383 2384 if (!pch) 2385 return; /* should never happen */ 2386 2387 chan->ppp = NULL; 2388 2389 /* 2390 * This ensures that we have returned from any calls into the 2391 * the channel's start_xmit or ioctl routine before we proceed. 2392 */ 2393 down_write(&pch->chan_sem); 2394 spin_lock_bh(&pch->downl); 2395 pch->chan = NULL; 2396 spin_unlock_bh(&pch->downl); 2397 up_write(&pch->chan_sem); 2398 ppp_disconnect_channel(pch); 2399 2400 pn = ppp_pernet(pch->chan_net); 2401 spin_lock_bh(&pn->all_channels_lock); 2402 list_del(&pch->list); 2403 spin_unlock_bh(&pn->all_channels_lock); 2404 2405 pch->file.dead = 1; 2406 wake_up_interruptible(&pch->file.rwait); 2407 if (atomic_dec_and_test(&pch->file.refcnt)) 2408 ppp_destroy_channel(pch); 2409 } 2410 2411 /* 2412 * Callback from a channel when it can accept more to transmit. 2413 * This should be called at BH/softirq level, not interrupt level. 2414 */ 2415 void 2416 ppp_output_wakeup(struct ppp_channel *chan) 2417 { 2418 struct channel *pch = chan->ppp; 2419 2420 if (!pch) 2421 return; 2422 ppp_channel_push(pch); 2423 } 2424 2425 /* 2426 * Compression control. 2427 */ 2428 2429 /* Process the PPPIOCSCOMPRESS ioctl. */ 2430 static int 2431 ppp_set_compress(struct ppp *ppp, unsigned long arg) 2432 { 2433 int err; 2434 struct compressor *cp, *ocomp; 2435 struct ppp_option_data data; 2436 void *state, *ostate; 2437 unsigned char ccp_option[CCP_MAX_OPTION_LENGTH]; 2438 2439 err = -EFAULT; 2440 if (copy_from_user(&data, (void __user *) arg, sizeof(data)) || 2441 (data.length <= CCP_MAX_OPTION_LENGTH && 2442 copy_from_user(ccp_option, (void __user *) data.ptr, data.length))) 2443 goto out; 2444 err = -EINVAL; 2445 if (data.length > CCP_MAX_OPTION_LENGTH || 2446 ccp_option[1] < 2 || ccp_option[1] > data.length) 2447 goto out; 2448 2449 cp = try_then_request_module( 2450 find_compressor(ccp_option[0]), 2451 "ppp-compress-%d", ccp_option[0]); 2452 if (!cp) 2453 goto out; 2454 2455 err = -ENOBUFS; 2456 if (data.transmit) { 2457 state = cp->comp_alloc(ccp_option, data.length); 2458 if (state) { 2459 ppp_xmit_lock(ppp); 2460 ppp->xstate &= ~SC_COMP_RUN; 2461 ocomp = ppp->xcomp; 2462 ostate = ppp->xc_state; 2463 ppp->xcomp = cp; 2464 ppp->xc_state = state; 2465 ppp_xmit_unlock(ppp); 2466 if (ostate) { 2467 ocomp->comp_free(ostate); 2468 module_put(ocomp->owner); 2469 } 2470 err = 0; 2471 } else 2472 module_put(cp->owner); 2473 2474 } else { 2475 state = cp->decomp_alloc(ccp_option, data.length); 2476 if (state) { 2477 ppp_recv_lock(ppp); 2478 ppp->rstate &= ~SC_DECOMP_RUN; 2479 ocomp = ppp->rcomp; 2480 ostate = ppp->rc_state; 2481 ppp->rcomp = cp; 2482 ppp->rc_state = state; 2483 ppp_recv_unlock(ppp); 2484 if (ostate) { 2485 ocomp->decomp_free(ostate); 2486 module_put(ocomp->owner); 2487 } 2488 err = 0; 2489 } else 2490 module_put(cp->owner); 2491 } 2492 2493 out: 2494 return err; 2495 } 2496 2497 /* 2498 * Look at a CCP packet and update our state accordingly. 2499 * We assume the caller has the xmit or recv path locked. 2500 */ 2501 static void 2502 ppp_ccp_peek(struct ppp *ppp, struct sk_buff *skb, int inbound) 2503 { 2504 unsigned char *dp; 2505 int len; 2506 2507 if (!pskb_may_pull(skb, CCP_HDRLEN + 2)) 2508 return; /* no header */ 2509 dp = skb->data + 2; 2510 2511 switch (CCP_CODE(dp)) { 2512 case CCP_CONFREQ: 2513 2514 /* A ConfReq starts negotiation of compression 2515 * in one direction of transmission, 2516 * and hence brings it down...but which way? 2517 * 2518 * Remember: 2519 * A ConfReq indicates what the sender would like to receive 2520 */ 2521 if(inbound) 2522 /* He is proposing what I should send */ 2523 ppp->xstate &= ~SC_COMP_RUN; 2524 else 2525 /* I am proposing to what he should send */ 2526 ppp->rstate &= ~SC_DECOMP_RUN; 2527 2528 break; 2529 2530 case CCP_TERMREQ: 2531 case CCP_TERMACK: 2532 /* 2533 * CCP is going down, both directions of transmission 2534 */ 2535 ppp->rstate &= ~SC_DECOMP_RUN; 2536 ppp->xstate &= ~SC_COMP_RUN; 2537 break; 2538 2539 case CCP_CONFACK: 2540 if ((ppp->flags & (SC_CCP_OPEN | SC_CCP_UP)) != SC_CCP_OPEN) 2541 break; 2542 len = CCP_LENGTH(dp); 2543 if (!pskb_may_pull(skb, len + 2)) 2544 return; /* too short */ 2545 dp += CCP_HDRLEN; 2546 len -= CCP_HDRLEN; 2547 if (len < CCP_OPT_MINLEN || len < CCP_OPT_LENGTH(dp)) 2548 break; 2549 if (inbound) { 2550 /* we will start receiving compressed packets */ 2551 if (!ppp->rc_state) 2552 break; 2553 if (ppp->rcomp->decomp_init(ppp->rc_state, dp, len, 2554 ppp->file.index, 0, ppp->mru, ppp->debug)) { 2555 ppp->rstate |= SC_DECOMP_RUN; 2556 ppp->rstate &= ~(SC_DC_ERROR | SC_DC_FERROR); 2557 } 2558 } else { 2559 /* we will soon start sending compressed packets */ 2560 if (!ppp->xc_state) 2561 break; 2562 if (ppp->xcomp->comp_init(ppp->xc_state, dp, len, 2563 ppp->file.index, 0, ppp->debug)) 2564 ppp->xstate |= SC_COMP_RUN; 2565 } 2566 break; 2567 2568 case CCP_RESETACK: 2569 /* reset the [de]compressor */ 2570 if ((ppp->flags & SC_CCP_UP) == 0) 2571 break; 2572 if (inbound) { 2573 if (ppp->rc_state && (ppp->rstate & SC_DECOMP_RUN)) { 2574 ppp->rcomp->decomp_reset(ppp->rc_state); 2575 ppp->rstate &= ~SC_DC_ERROR; 2576 } 2577 } else { 2578 if (ppp->xc_state && (ppp->xstate & SC_COMP_RUN)) 2579 ppp->xcomp->comp_reset(ppp->xc_state); 2580 } 2581 break; 2582 } 2583 } 2584 2585 /* Free up compression resources. */ 2586 static void 2587 ppp_ccp_closed(struct ppp *ppp) 2588 { 2589 void *xstate, *rstate; 2590 struct compressor *xcomp, *rcomp; 2591 2592 ppp_lock(ppp); 2593 ppp->flags &= ~(SC_CCP_OPEN | SC_CCP_UP); 2594 ppp->xstate = 0; 2595 xcomp = ppp->xcomp; 2596 xstate = ppp->xc_state; 2597 ppp->xc_state = NULL; 2598 ppp->rstate = 0; 2599 rcomp = ppp->rcomp; 2600 rstate = ppp->rc_state; 2601 ppp->rc_state = NULL; 2602 ppp_unlock(ppp); 2603 2604 if (xstate) { 2605 xcomp->comp_free(xstate); 2606 module_put(xcomp->owner); 2607 } 2608 if (rstate) { 2609 rcomp->decomp_free(rstate); 2610 module_put(rcomp->owner); 2611 } 2612 } 2613 2614 /* List of compressors. */ 2615 static LIST_HEAD(compressor_list); 2616 static DEFINE_SPINLOCK(compressor_list_lock); 2617 2618 struct compressor_entry { 2619 struct list_head list; 2620 struct compressor *comp; 2621 }; 2622 2623 static struct compressor_entry * 2624 find_comp_entry(int proto) 2625 { 2626 struct compressor_entry *ce; 2627 2628 list_for_each_entry(ce, &compressor_list, list) { 2629 if (ce->comp->compress_proto == proto) 2630 return ce; 2631 } 2632 return NULL; 2633 } 2634 2635 /* Register a compressor */ 2636 int 2637 ppp_register_compressor(struct compressor *cp) 2638 { 2639 struct compressor_entry *ce; 2640 int ret; 2641 spin_lock(&compressor_list_lock); 2642 ret = -EEXIST; 2643 if (find_comp_entry(cp->compress_proto)) 2644 goto out; 2645 ret = -ENOMEM; 2646 ce = kmalloc(sizeof(struct compressor_entry), GFP_ATOMIC); 2647 if (!ce) 2648 goto out; 2649 ret = 0; 2650 ce->comp = cp; 2651 list_add(&ce->list, &compressor_list); 2652 out: 2653 spin_unlock(&compressor_list_lock); 2654 return ret; 2655 } 2656 2657 /* Unregister a compressor */ 2658 void 2659 ppp_unregister_compressor(struct compressor *cp) 2660 { 2661 struct compressor_entry *ce; 2662 2663 spin_lock(&compressor_list_lock); 2664 ce = find_comp_entry(cp->compress_proto); 2665 if (ce && ce->comp == cp) { 2666 list_del(&ce->list); 2667 kfree(ce); 2668 } 2669 spin_unlock(&compressor_list_lock); 2670 } 2671 2672 /* Find a compressor. */ 2673 static struct compressor * 2674 find_compressor(int type) 2675 { 2676 struct compressor_entry *ce; 2677 struct compressor *cp = NULL; 2678 2679 spin_lock(&compressor_list_lock); 2680 ce = find_comp_entry(type); 2681 if (ce) { 2682 cp = ce->comp; 2683 if (!try_module_get(cp->owner)) 2684 cp = NULL; 2685 } 2686 spin_unlock(&compressor_list_lock); 2687 return cp; 2688 } 2689 2690 /* 2691 * Miscelleneous stuff. 2692 */ 2693 2694 static void 2695 ppp_get_stats(struct ppp *ppp, struct ppp_stats *st) 2696 { 2697 struct slcompress *vj = ppp->vj; 2698 2699 memset(st, 0, sizeof(*st)); 2700 st->p.ppp_ipackets = ppp->stats64.rx_packets; 2701 st->p.ppp_ierrors = ppp->dev->stats.rx_errors; 2702 st->p.ppp_ibytes = ppp->stats64.rx_bytes; 2703 st->p.ppp_opackets = ppp->stats64.tx_packets; 2704 st->p.ppp_oerrors = ppp->dev->stats.tx_errors; 2705 st->p.ppp_obytes = ppp->stats64.tx_bytes; 2706 if (!vj) 2707 return; 2708 st->vj.vjs_packets = vj->sls_o_compressed + vj->sls_o_uncompressed; 2709 st->vj.vjs_compressed = vj->sls_o_compressed; 2710 st->vj.vjs_searches = vj->sls_o_searches; 2711 st->vj.vjs_misses = vj->sls_o_misses; 2712 st->vj.vjs_errorin = vj->sls_i_error; 2713 st->vj.vjs_tossed = vj->sls_i_tossed; 2714 st->vj.vjs_uncompressedin = vj->sls_i_uncompressed; 2715 st->vj.vjs_compressedin = vj->sls_i_compressed; 2716 } 2717 2718 /* 2719 * Stuff for handling the lists of ppp units and channels 2720 * and for initialization. 2721 */ 2722 2723 /* 2724 * Create a new ppp interface unit. Fails if it can't allocate memory 2725 * or if there is already a unit with the requested number. 2726 * unit == -1 means allocate a new number. 2727 */ 2728 static struct ppp *ppp_create_interface(struct net *net, int unit, 2729 struct file *file, int *retp) 2730 { 2731 struct ppp *ppp; 2732 struct ppp_net *pn; 2733 struct net_device *dev = NULL; 2734 int ret = -ENOMEM; 2735 int i; 2736 2737 dev = alloc_netdev(sizeof(struct ppp), "", NET_NAME_ENUM, ppp_setup); 2738 if (!dev) 2739 goto out1; 2740 2741 pn = ppp_pernet(net); 2742 2743 ppp = netdev_priv(dev); 2744 ppp->dev = dev; 2745 ppp->mru = PPP_MRU; 2746 init_ppp_file(&ppp->file, INTERFACE); 2747 ppp->file.hdrlen = PPP_HDRLEN - 2; /* don't count proto bytes */ 2748 ppp->owner = file; 2749 for (i = 0; i < NUM_NP; ++i) 2750 ppp->npmode[i] = NPMODE_PASS; 2751 INIT_LIST_HEAD(&ppp->channels); 2752 spin_lock_init(&ppp->rlock); 2753 spin_lock_init(&ppp->wlock); 2754 #ifdef CONFIG_PPP_MULTILINK 2755 ppp->minseq = -1; 2756 skb_queue_head_init(&ppp->mrq); 2757 #endif /* CONFIG_PPP_MULTILINK */ 2758 #ifdef CONFIG_PPP_FILTER 2759 ppp->pass_filter = NULL; 2760 ppp->active_filter = NULL; 2761 #endif /* CONFIG_PPP_FILTER */ 2762 2763 /* 2764 * drum roll: don't forget to set 2765 * the net device is belong to 2766 */ 2767 dev_net_set(dev, net); 2768 2769 rtnl_lock(); 2770 mutex_lock(&pn->all_ppp_mutex); 2771 2772 if (unit < 0) { 2773 unit = unit_get(&pn->units_idr, ppp); 2774 if (unit < 0) { 2775 ret = unit; 2776 goto out2; 2777 } 2778 } else { 2779 ret = -EEXIST; 2780 if (unit_find(&pn->units_idr, unit)) 2781 goto out2; /* unit already exists */ 2782 /* 2783 * if caller need a specified unit number 2784 * lets try to satisfy him, otherwise -- 2785 * he should better ask us for new unit number 2786 * 2787 * NOTE: yes I know that returning EEXIST it's not 2788 * fair but at least pppd will ask us to allocate 2789 * new unit in this case so user is happy :) 2790 */ 2791 unit = unit_set(&pn->units_idr, ppp, unit); 2792 if (unit < 0) 2793 goto out2; 2794 } 2795 2796 /* Initialize the new ppp unit */ 2797 ppp->file.index = unit; 2798 sprintf(dev->name, "ppp%d", unit); 2799 2800 ret = register_netdevice(dev); 2801 if (ret != 0) { 2802 unit_put(&pn->units_idr, unit); 2803 netdev_err(ppp->dev, "PPP: couldn't register device %s (%d)\n", 2804 dev->name, ret); 2805 goto out2; 2806 } 2807 2808 ppp->ppp_net = net; 2809 2810 atomic_inc(&ppp_unit_count); 2811 mutex_unlock(&pn->all_ppp_mutex); 2812 rtnl_unlock(); 2813 2814 *retp = 0; 2815 return ppp; 2816 2817 out2: 2818 mutex_unlock(&pn->all_ppp_mutex); 2819 rtnl_unlock(); 2820 free_netdev(dev); 2821 out1: 2822 *retp = ret; 2823 return NULL; 2824 } 2825 2826 /* 2827 * Initialize a ppp_file structure. 2828 */ 2829 static void 2830 init_ppp_file(struct ppp_file *pf, int kind) 2831 { 2832 pf->kind = kind; 2833 skb_queue_head_init(&pf->xq); 2834 skb_queue_head_init(&pf->rq); 2835 atomic_set(&pf->refcnt, 1); 2836 init_waitqueue_head(&pf->rwait); 2837 } 2838 2839 /* 2840 * Free the memory used by a ppp unit. This is only called once 2841 * there are no channels connected to the unit and no file structs 2842 * that reference the unit. 2843 */ 2844 static void ppp_destroy_interface(struct ppp *ppp) 2845 { 2846 atomic_dec(&ppp_unit_count); 2847 2848 if (!ppp->file.dead || ppp->n_channels) { 2849 /* "can't happen" */ 2850 netdev_err(ppp->dev, "ppp: destroying ppp struct %p " 2851 "but dead=%d n_channels=%d !\n", 2852 ppp, ppp->file.dead, ppp->n_channels); 2853 return; 2854 } 2855 2856 ppp_ccp_closed(ppp); 2857 if (ppp->vj) { 2858 slhc_free(ppp->vj); 2859 ppp->vj = NULL; 2860 } 2861 skb_queue_purge(&ppp->file.xq); 2862 skb_queue_purge(&ppp->file.rq); 2863 #ifdef CONFIG_PPP_MULTILINK 2864 skb_queue_purge(&ppp->mrq); 2865 #endif /* CONFIG_PPP_MULTILINK */ 2866 #ifdef CONFIG_PPP_FILTER 2867 if (ppp->pass_filter) { 2868 bpf_prog_destroy(ppp->pass_filter); 2869 ppp->pass_filter = NULL; 2870 } 2871 2872 if (ppp->active_filter) { 2873 bpf_prog_destroy(ppp->active_filter); 2874 ppp->active_filter = NULL; 2875 } 2876 #endif /* CONFIG_PPP_FILTER */ 2877 2878 kfree_skb(ppp->xmit_pending); 2879 2880 free_netdev(ppp->dev); 2881 } 2882 2883 /* 2884 * Locate an existing ppp unit. 2885 * The caller should have locked the all_ppp_mutex. 2886 */ 2887 static struct ppp * 2888 ppp_find_unit(struct ppp_net *pn, int unit) 2889 { 2890 return unit_find(&pn->units_idr, unit); 2891 } 2892 2893 /* 2894 * Locate an existing ppp channel. 2895 * The caller should have locked the all_channels_lock. 2896 * First we look in the new_channels list, then in the 2897 * all_channels list. If found in the new_channels list, 2898 * we move it to the all_channels list. This is for speed 2899 * when we have a lot of channels in use. 2900 */ 2901 static struct channel * 2902 ppp_find_channel(struct ppp_net *pn, int unit) 2903 { 2904 struct channel *pch; 2905 2906 list_for_each_entry(pch, &pn->new_channels, list) { 2907 if (pch->file.index == unit) { 2908 list_move(&pch->list, &pn->all_channels); 2909 return pch; 2910 } 2911 } 2912 2913 list_for_each_entry(pch, &pn->all_channels, list) { 2914 if (pch->file.index == unit) 2915 return pch; 2916 } 2917 2918 return NULL; 2919 } 2920 2921 /* 2922 * Connect a PPP channel to a PPP interface unit. 2923 */ 2924 static int 2925 ppp_connect_channel(struct channel *pch, int unit) 2926 { 2927 struct ppp *ppp; 2928 struct ppp_net *pn; 2929 int ret = -ENXIO; 2930 int hdrlen; 2931 2932 pn = ppp_pernet(pch->chan_net); 2933 2934 mutex_lock(&pn->all_ppp_mutex); 2935 ppp = ppp_find_unit(pn, unit); 2936 if (!ppp) 2937 goto out; 2938 write_lock_bh(&pch->upl); 2939 ret = -EINVAL; 2940 if (pch->ppp) 2941 goto outl; 2942 2943 ppp_lock(ppp); 2944 if (pch->file.hdrlen > ppp->file.hdrlen) 2945 ppp->file.hdrlen = pch->file.hdrlen; 2946 hdrlen = pch->file.hdrlen + 2; /* for protocol bytes */ 2947 if (hdrlen > ppp->dev->hard_header_len) 2948 ppp->dev->hard_header_len = hdrlen; 2949 list_add_tail(&pch->clist, &ppp->channels); 2950 ++ppp->n_channels; 2951 pch->ppp = ppp; 2952 atomic_inc(&ppp->file.refcnt); 2953 ppp_unlock(ppp); 2954 ret = 0; 2955 2956 outl: 2957 write_unlock_bh(&pch->upl); 2958 out: 2959 mutex_unlock(&pn->all_ppp_mutex); 2960 return ret; 2961 } 2962 2963 /* 2964 * Disconnect a channel from its ppp unit. 2965 */ 2966 static int 2967 ppp_disconnect_channel(struct channel *pch) 2968 { 2969 struct ppp *ppp; 2970 int err = -EINVAL; 2971 2972 write_lock_bh(&pch->upl); 2973 ppp = pch->ppp; 2974 pch->ppp = NULL; 2975 write_unlock_bh(&pch->upl); 2976 if (ppp) { 2977 /* remove it from the ppp unit's list */ 2978 ppp_lock(ppp); 2979 list_del(&pch->clist); 2980 if (--ppp->n_channels == 0) 2981 wake_up_interruptible(&ppp->file.rwait); 2982 ppp_unlock(ppp); 2983 if (atomic_dec_and_test(&ppp->file.refcnt)) 2984 ppp_destroy_interface(ppp); 2985 err = 0; 2986 } 2987 return err; 2988 } 2989 2990 /* 2991 * Free up the resources used by a ppp channel. 2992 */ 2993 static void ppp_destroy_channel(struct channel *pch) 2994 { 2995 atomic_dec(&channel_count); 2996 2997 if (!pch->file.dead) { 2998 /* "can't happen" */ 2999 pr_err("ppp: destroying undead channel %p !\n", pch); 3000 return; 3001 } 3002 skb_queue_purge(&pch->file.xq); 3003 skb_queue_purge(&pch->file.rq); 3004 kfree(pch); 3005 } 3006 3007 static void __exit ppp_cleanup(void) 3008 { 3009 /* should never happen */ 3010 if (atomic_read(&ppp_unit_count) || atomic_read(&channel_count)) 3011 pr_err("PPP: removing module but units remain!\n"); 3012 unregister_chrdev(PPP_MAJOR, "ppp"); 3013 device_destroy(ppp_class, MKDEV(PPP_MAJOR, 0)); 3014 class_destroy(ppp_class); 3015 unregister_pernet_device(&ppp_net_ops); 3016 } 3017 3018 /* 3019 * Units handling. Caller must protect concurrent access 3020 * by holding all_ppp_mutex 3021 */ 3022 3023 /* associate pointer with specified number */ 3024 static int unit_set(struct idr *p, void *ptr, int n) 3025 { 3026 int unit; 3027 3028 unit = idr_alloc(p, ptr, n, n + 1, GFP_KERNEL); 3029 if (unit == -ENOSPC) 3030 unit = -EINVAL; 3031 return unit; 3032 } 3033 3034 /* get new free unit number and associate pointer with it */ 3035 static int unit_get(struct idr *p, void *ptr) 3036 { 3037 return idr_alloc(p, ptr, 0, 0, GFP_KERNEL); 3038 } 3039 3040 /* put unit number back to a pool */ 3041 static void unit_put(struct idr *p, int n) 3042 { 3043 idr_remove(p, n); 3044 } 3045 3046 /* get pointer associated with the number */ 3047 static void *unit_find(struct idr *p, int n) 3048 { 3049 return idr_find(p, n); 3050 } 3051 3052 /* Module/initialization stuff */ 3053 3054 module_init(ppp_init); 3055 module_exit(ppp_cleanup); 3056 3057 EXPORT_SYMBOL(ppp_register_net_channel); 3058 EXPORT_SYMBOL(ppp_register_channel); 3059 EXPORT_SYMBOL(ppp_unregister_channel); 3060 EXPORT_SYMBOL(ppp_channel_index); 3061 EXPORT_SYMBOL(ppp_unit_number); 3062 EXPORT_SYMBOL(ppp_dev_name); 3063 EXPORT_SYMBOL(ppp_input); 3064 EXPORT_SYMBOL(ppp_input_error); 3065 EXPORT_SYMBOL(ppp_output_wakeup); 3066 EXPORT_SYMBOL(ppp_register_compressor); 3067 EXPORT_SYMBOL(ppp_unregister_compressor); 3068 MODULE_LICENSE("GPL"); 3069 MODULE_ALIAS_CHARDEV(PPP_MAJOR, 0); 3070 MODULE_ALIAS("devname:ppp"); 3071